Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/28/14


AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
812 PM PDT SUN APR 27 2014 .UPDATE...WINDS HAVE REMAINED BELOW ADVISORY LEVELS OVER THE KERN COUNTY MOUNTAINS AND DESERT. THE ADVISORY HAS BEEN CANCELED. && .SYNOPSIS... LOCALLY GUSTY WINDS WILL CONTINUE INTO TONIGHT OVER THE KERN COUNTY MOUNTAINS AND DESERT. HIGH PRESSURE WILL BE BUILD OVER THE DISTRICT DURING THE NEXT FEW DAYS AND BRING MOSTLY CLEAR SKIES AND A DAY TO DAY WARMING TREND THROUGH MIDWEEK. && .DISCUSSION...OBSERVATIONS FROM MESONET SITES SHOW THE WIND HAS NOT REACHED ADVISORY LEVELS OVER THE KERN COUNTY MOUNTAINS IN CONTRAST TO BOTH THE HRRR AND NAMDNG5 MODELS SHOWING STRONGER VALUES. THE ADVISORY HAS BEEN CANCELLED. NO OTHER CHANGES TO THE GRIDS AS THE WARMING TREND REMAINS ON TRACK. && .AVIATION... MVFR WITH LOCAL MTN OBSCURING IFR CONDITIONS WILL PERSIST ALONG THE WEST SLOPES OF THE SIERRA AND THE NORTH FACING SLOPES OF THE TEHACHAPI MOUNTAINS THROUGH 06Z MONDAY. VFR CONDITIONS WILL PREVAIL ELSEWHERE ACROSS THE CENTRAL CALIFORNIA INTERIOR DURING THE NEXT 24 HOURS. ADDITIONALLY...WINDS OF 35 KNOTS OR GREATER WILL CONTINUE THROUGH AND JUST BELOW THE MOUNTAIN PASSES OF KERN COUNTY UNTIL 12Z MONDAY. && .PREV DISC... /ISSUED 224 PM PDT SUN APR 27 2014/ DISCUSSION...THE LATE APRIL SUN HAS PRODUCED SIGNIFICANT WARMING TODAY. TEMPERATURES ARE TRENDING A GOOD 5 TO 15 DEGREES HIGHER THROUGHOUT THE CWA THIS AFTERNOON COMPARED TO SATURDAY AFTERNOON. THE WARMING TREND WILL CONTINUE UNDAUNTED THROUGH THE MIDDLE OF THIS WEEK AS AN UPPER LEVEL RIDGE OF HIGH PRESSURE BUILDS OVER CA. THE RIDGE HAS ALREADY BUILT UP ENOUGH TODAY TO THWART THE SOUTHEASTWARD MOVEMENT OF A WEAK COLD FRONT THAT EXTENDS FROM REDDING TO THE SFO BAY AREA TO JUST OFFSHORE THE SOUTHERN CA COAST. SUBSIDENCE ASSOCIATED WITH THIS BUILDING HIGH PRESSURE RIDGE HAS EVAPORATED MUCH OF THE MOISTURE ASSOCIATED WITH THIS FRONT THIS AFTERNOON. MEANWHILE...LEFTOVER MOISTURE FROM OUR RECENT STORM IS SHOWING UP AS STRATOCUMULUS THAT HAS REMAINED BANKED UP IN THE ONSHORE FLOW ALONG THE WEST SLOPES OF THE MOUNTAINS IN TULARE COUNTY AND KERN COUNTY THIS AFTERNOON. ALTHOUGH THE ONSHORE FLOW HAS WEAKENED SOME SINCE SATURDAY...IT WILL SUPPORT A SHALLOW PUSH OF MARINE AIR INTO THE SJ VLY THIS EVENING. WEST WINDS BLOWING THROUGH AND BELOW THE MOUNTAIN PASSES OF KERN COUNTY HAVE NOT YET PEAKED ABOVE ADVISORY LEVELS BUT ARE GRADUALLY INCREASING...SO WILL LET THE WIND ADVISORY FOR THIS REGION CONTINUE INTO THIS EVENING. THE ONSHORE FLOW IS FORECAST TO SLOWLY DIMINISH DURING THE NEXT 24 HRS THEN BECOME OFFSHORE BY TUESDAY WHILE THE UPPER LEVEL RIDGE AMPLIFIES ALONG THE WEST COAST. TEMPERATURES WILL RECOVER TO SEASONABLE LEVELS MONDAY AFTERNOON. THE REMAINDER OF THE 7 DAY PERIOD WILL BE DRY AND SUBSTANTIALLY WARMER. MAX TEMPS WILL BE ABOVE 90 DEGREES IN THE SJ VLY AND LOWER FOOTHILLS BY WEDNESDAY AND WELL INTO THE 90S THURSDAY AND FRIDAY BEFORE TRENDING DOWNWARD A BIT NEXT WEEKEND AS THE HIGH PRESSURE RIDGE WEAKENS. ON A FINAL NOTE...THE 12Z RUN OF THE ECM AND GFS FORECAST ANOTHER DEEP UPPER LEVEL TROUGH TO MOVE INTO CA BETWEEN THE 6TH AND 7TH OF MAY. WHETHER OR NOT THIS FEATURE BRINGS SHOWERS...IF ANY...IS SOMETHING WE ARE NOT CONFIDENT OF AT ALL. WHAT IS MORE CERTAIN IS THAT TEMPERATURES WILL PROBABLY TREND COOLER DURING THIS PERIOD ..AT LEAST CLOSER TO NORMAL. && .AIR QUALITY ISSUES... NONE. && .CERTAINTY... THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH. THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS HIGH. THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD. CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL INFORMATION AND/OR TO PROVIDE FEEDBACK. && .CLIMATE... RECORDS SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR KFAT 04-27 98:2004 56:1894 65:1926 36:1955 KFAT 04-28 98:2007 50:1906 65:1987 36:1970 KFAT 04-29 96:1981 60:1951 65:1992 35:1970 KBFL 04-27 98:2004 60:1932 67:1965 34:1984 KBFL 04-28 97:2007 54:1906 66:1965 38:1999 KBFL 04-29 100:1981 61:1967 64:2007 40:1984 && .HNX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ PUBLIC...DUDLEY AVN/FW...BEAN PREV DISCUSSION...DURFEE SYNOPSIS...BSO WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
856 PM MDT SUN APR 27 2014 .UPDATE... ISSUED AT 856 PM MDT SUN APR 27 2014 UPDATED FOR LATEST OBS...SATELLITE AND RADAR TRENDS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 327 PM MDT SUN APR 27 2014 CURRENTLY...STRONG UPPER LEVEL AND SURFACE LOW PRESSURE STACKED OVER NORTHWESTERN KS WITH SOUTHERN END OF WRAP AROUND DEFORMATION PRECIP SLOWLY WEAKENING OVER SOUTHEAST CO. FARTHER WEST...LAPS SURFACE PRESSURE DATA SHOWS WEAK SECONDARY LOW PRESSURE NEAR KPUB...WHICH HAS CREATED LIGHTER WINDS OVER MUCH OF PUEBLO COUNTY THIS AFTERNOON...AND HAS IN GENERAL WEAKENED THE PRESSURE GRADIENT ACROSS SOUTHEAST COLORADO. WITH CONVECTION ENDING AND STRONG SURFACE GRADIENT LACKING...WIND SPEEDS HAVE BEGUN TO VERY SLOWLY DECREASE ACROSS THE PLAINS...AND STRONGEST GUSTS HAVE FALLEN BACK INTO THE 40- 45 KT RANGE. LATEST HRRR SUGGESTS WIND SPEEDS HAVE ALREADY PEAKED...AND GIVEN LACK OF OBSERVED 50 KT GUSTS...WILL CANCEL THE HIGH WIND WARNING FOR THE FAR SOUTHEAST. OVER THE MOUNTAINS...STILL SOME -SHSN OVER THE CONTINENTAL DIVIDE...THOUGH WEB CAMS SUGGEST LITTLE IN THE WAY OF ACCUMULATION OR LOW VISIBILITY...AT LEAST AT PASS LEVEL. TONIGHT...WILL KEEP SOME LOW POPS IN THE EVENING TO ACCOUNT FOR LINGERING -SHRA OVER THE SOUTHEAST PLAINS...WITH SOME HIGHER POPS FOR THE CENTRAL MOUNTAINS ALONG THE CONTINENTAL DIVIDE...WHERE SECONDARY UPPER WAVE WILL LIKELY HELP INCREASE -SHSN COVERAGE LATER TONIGHT. EXPECT WINDS TO GRADUALLY DIMINISH ALL AREAS THROUGH THE NIGHT...THOUGH MANY LOCATIONS WILL STAY BREEZY AS STRONG WINDS JUST OFF THE SURFACE PERSIST. EXPECTING ENOUGH IN THE WAY OF WINDS/CLOUDS TO KEEP PLAINS FROM A HARD FREEZE...THOUGH MOST MOUNTAINS AND HIGH VALLEYS WILL DROP INTO THE 20S OR COLDER. MONDAY...UPPER LOW VERY SLOWLY DRIFTS INTO ERN NEBRASKA DURING THE DAY...KEEPING STRONG NW FLOW AT THE SURFACE AND ALOFT ACROSS MOST OF SOUTHERN COLORADO. EXPECT WINDS TO INCREASE ALL AREAS BY MID MORNING...WITH GUSTS IN THE 30-40 KT RANGE MOST LOCATIONS BY AFTERNOON. GIVEN RATHER COLD AIR ALOFT/STEEP LAPSE RATES IN PLACE MON AFTERNOON...SUSPECT AT LEAST ISOLATED RAIN AND SNOW SHOWERS WILL DEVELOP OVER THE MOUNTAINS...WITH PERHAPS A FEW SPRINKLES/LIGHT SHOWERS OVER LOWER ELEVATIONS LATE IN THE DAY. LOW LEVELS WILL BE FAIRLY DRY...WHICH WILL KEEP PRECIP AMOUNTS LIGHT. MAX TEMPS WILL REMAIN COOL...WITH BLENDED NUMERICAL GUIDANCE LOOKING OK FOR HIGHS. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 327 PM MDT SUN APR 27 2014 VERY UNSETTLED PATTERN QUEUED UP FOR THE FORECAST AREA THROUGH THE EXTENDED FORECAST...BUT MODELS ARE LEANING TOWARDS TWO SEPARATE PERIODS OF WEATHER TYPES. MONDAY NIGHT THROUGH THURSDAY...LONG RANGE MODELS INDICATE THAT THE UPPER LOW PRESSURE SYSTEM WILL PINWHEEL ABOUT THE US CENTRAL PLAINS AND UPPER MISSISSIPPI RIVER VALLEY THROUGH THU...BEFORE FINALLY EJECTING TO THE NE ACROSS THE GREAT LAKES. THIS SOLUTION WILL KEEP VERY BRISK AND COOL NORTHERLY FLOW IN PLACE FOR THE STATE INTO THU...AS WELL AS A DAILY SHOT OF SHOWER ACTIVITY FOR THE CWA. AS THE LOW LINGERS...LOBES OF ENERGY WILL ROTATE AROUND THE SYSTEM AND BRING PERIODICALLY BETTER CHANCES FOR SHOWERS...THOUGH THE EXACT TIMING OF THESE WINDOWS IS NEAR IMPOSSIBLE TO PREDICT AT THIS TIME. LOOK FOR MAX TEMPS EACH DAY IN THE 50S TO AROUND 60 F FOR THE LOWER ELEVATIONS...AND 30S TO 40S FOR THE MTS. THE HIGHER TERRAIN IS EXPECTED TO EXPERIENCE ISOLATED TO LOW END SCATTERED POPS THROUGH THU...WITH THE BEST SHOT OF SOME ISOLATED CONVECTION FOR THE PLAINS COMING TUE AFTN...AND AGAIN WED AFTN AND EVE. FRIDAY THROUGH SUNDAY...THE GFS AND EC MODELS HINT THAT BY FRI THE UPPER LOW WILL FINALLY BE PULLING AWAY FROM THE REGION...ALLOWING THE UPPER FLOW TO SHIFT TO A MORE WESTERLY DIRECTION INTO THE WEEKEND. BOTH MODELS DO CONTINUE TO SHOW MEAGER SHOWER ACTIVITY BOTH FRI AND SAT...MAINLY TIED TO THE HIGHER TERRAIN...BUT FEEL THAT THIS FAR OUT THIS MAY BE A BIT OVERDONE. BY SUNDAY PCPN SHOULD COME TO AN END. LOOK FOR A WARMING TREND INTO THE WEEKEND AS THE UPPER FLOW SHIFTS...WITH MAX TEMPS IN THE 60S FOR FRI...THEN 70S FOR BOTH SAT AND SUN. MOORE && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 327 PM MDT SUN APR 27 2014 EXPECT VFR CONDITIONS ALL TAF SITES TONIGHT AND MONDAY. GUSTY WINDS AT KCOS AND KALS WILL GRADUALLY DIMINISH AFTER 02Z...THOUGH W-NW WINDS IN THE 10-15 KT RANGE MAY PERSIST THROUGH THE NIGHT. ON MON...NW WINDS WILL INCREASE QUICKLY DURING THE MORNING...WITH GUSTS TO 25 KTS ALL TERMINALS BY 16Z...THEN A FEW GUSTS IN THE 30-35 KT BY 20Z. MAY SEE SOME VIRGA/-SHRA OVER THE MOUNTAINS DRIFT TOWARD KCOS AND KALS AFTER 20Z AS WELL...THOUGH NOT EXPECTING ANY CIG/VIS RESTRICTIONS. OVER THE MOUNTAINS...-SHSN WILL PERSIST THROUGH THE NIGHT...ESPECIALLY NORTH OF MONARCH PASS...WHERE AREAS OF IFR CONDITIONS WILL BE POSSIBLE THROUGH 12Z. ON MON...SHOWERS WILL REDEVELOP WITH PEAKS BECOMING OBSCURED MANY AREAS AFTER 18Z. OVER THE PLAINS...-SHRA WILL CONTINUE TO DIMINISH THROUGH THE EVENING WITH VFR CONDITIONS ALL AREAS BY 02Z. WINDS WILL ALSO SLOWLY DIMINISH THROUGH THE EVENING. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MW SHORT TERM...PETERSEN LONG TERM...MOORE AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1006 PM EDT SUN APR 27 2014 .SYNOPSIS... THE UPPER LEVEL DISTURBANCE THAT BROUGHT SHOWERS TO SOUTHERN NEW ENGLAND YESTERDAY AND TODAY WILL CONTINUE TO MOVE OFFSHORE. MAINLY DRY CONDITIONS WILL FOLLOW TOMORROW INTO TUESDAY AS HIGH PRESSURE RETURNS TO THE AREA. LOW PRESSURE WILL BRING A SOAKING RAIN WED INTO THU. SEASONABLE WEATHER IS THEN EXPECTED FRI INTO NEXT WEEKEND WITH DRY WEATHER LIKELY DOMINATING...OTHER THAN A FEW SPOT SHOWERS. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 10 PM UPDATE... STILL A SMALL AREA OF SHOWERS ROTATING SOUTH ACROSS SE MA AND E RI. HRRR SHOWS THESE SHOWERS DISSIPATING BY MIDNIGHT LEAVING DRY CONDITIONS OVERNIGHT. STRATOCU MOVING ACROSS THE REGION BUT THERE ARE NUMEROUS BREAKS. EXPECT PTCLDY SKIES WITH AN INCREASE IN MID LEVEL CLOUDS LATE ACROSS THE E. GENERALLY LIGHT WINDS ACROSS THE REGION SO SOME OPPORTUNITY FOR RADIATIONAL COOLING WHERE SKIES CLEAR. EXPECT MINS MOSTLY IN THE MID 30S TO NEAR 40. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... TOMORROW... BLOCKING OMEGA HIGH WILL BEGIN TO SLIDE E FROM THE GREAT LAKES AND SE CONUS AS ATTENDANT SFC HIGH PRES FORCES AN INVERTED HIGH PRES RIDGE ACROSS SRN NEW ENGLAND. THIS WILL YIELD A DRY FORECAST...BUT WITH CONTINUATION OF MID AND HIGH CLOUDS ACROSS THE E AS MOISTURE CONTINUES TO STREAM FROM CANADA ON THE PERIPHERY OF THE BLOCK. H85 TEMPS WARM TO ABOUT 0C...SO EVEN WITH FULL MIXING HIGH TEMPS WILL STILL REMAIN SLIGHTLY BELOW NORMAL FOR LATE APRIL...MAINLY IN THE UPPER 50S TO AROUND 60...WHICH IS AT LEAST WARMER THAN IT WAS OVER THE WEEKEND. THE CAVEAT WILL BE NEAR COASTAL LOCATIONS AS A NORTHEASTERLY DRAW DEVELOPS WITH THE INVERTED RIDGE...KEEPING ESPECIALLY E COASTAL LOCATIONS IN THE LOWER 50S. MON NIGHT... ONE LAST DIVING SHORTWAVE OUT OF CANADA AND WEAK WARM ADVECTION AND MOISTURE FLUX MAY LEAD TO AN ISOLATED -SHRA WITHIN THE WEAKENING INVERTED RIDGE. KEPT POPS AT SLIGHT CHANCE AS THESE ARE LIKELY TO BE WIDELY SCT AT BEST. OTHERWISE...MANY MORE CLOUDS EXPECTED. THEREFORE...MINS WILL BE MILD MAINLY IN THE LOW-MID 40S AT THEIR COLDEST. && .LONG TERM /TUESDAY THROUGH SUNDAY/... HIGHLIGHTS... * MAINLY DRY AND COOL WEATHER TUESDAY * RAINY AND COOL WEATHER WEDNESDAY * MILDER THURSDAY BUT STILL WET * SEASONABLE FRIDAY INTO NEXT WEEKEND W/DRY WEATHER DOMINATING DETAILS... TUESDAY... STRONG HIGH PRESSURE OVER EASTERN CANADA WILL COMBINED WITH A LOW PRESSURE SYSTEM WELL TO OUR WEST. MAINLY DRY WEATHER IS ANTICIPATED ON TUESDAY OTHER THAN THE LOW RISK FOR A BRIEF SPOT SHOWER OR TWO ACROSS THE INTERIOR. EASTERLY WINDS WILL RESULT IN UNSEASONABLY COOL HIGH TEMPS ESPECIALLY NEAR THE EASTERN MA COAST. HIGHS MAINLY IN THE UPPER 40S ALONG THE EASTERN MA COAST...TO PERHAPS THE LOWER TO MIDDLE 50S IN THE DISTANT INTERIOR. PLENTY OF CLOUDS AROUND BUT MAY SEE SOME PEEKS OF SUN WITH BEST CHANCE NEAR THE COAST...AS DRY AIR TRIES TO ACTUALLY COME IN OFF THE OCEAN. TUESDAY NIGHT... UPPER LEVEL RIDGING AND DRY LOW LEVEL AIR WILL SLOW THE ADVANCING LOW PRESSURE/RAIN SHIELD TO OUR WEST. WHILE WE MAY SEE A FEW SHOWERS TUE NIGHT WITH THE BEST CHANCE ACROSS THE INTERIOR...MUCH OF THE NIGHT MAY TURN OUT DRY. IT WILL BE COOL...WITH LOW TEMPS MAINLY IN THE 30S TO THE LOWER 40S. WEDNESDAY AND THURSDAY... STRENGTHENING LOW LEVEL JET ON WEDNESDAY WILL FINALLY ALLOW THE COLUMN TO SATURATE AND A SOAKING RAIN TO DEVELOP. STILL DISAGREEMENT AMONGST THE MODELS ON WHEN THIS HAPPENS...BUT TREND WILL BE FOR WET WEATHER TO OVERSPREAD THE REGION FROM WEST TO EAST ON WEDNESDAY. LOW LEVEL JET/PWATS EXPECTED TO BE 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL. THIS SHOULD YIELD TO A PERIOD OF HEAVY RAIN WEDNESDAY INTO THURSDAY. AT THIS TIME...LOOKS LIKE THE HEAVIEST OF THE RAIN WILL BE TO OUR SOUTHWEST WHERE BETTER MOISTURE/INSTABILITY COINCIDE. NONETHELESS...WE MAY SEE 1 TO 2 INCHES OF RAINFALL LEADING TO A PERIOD OF NUISANCE/MINOR POOR DRAINAGE STREET FLOODING. INSTABILITY IS RATHER MARGINAL IN OUR REGION...BUT LOW PROBABILITY FOR AN ISOLATED THUNDERSTORM OR TWO ON THURSDAY IF PORTIONS OF THE REGION CAN WARM SECTOR. AS FOR TEMPS...UNSEASONABLY COOL ON WEDNESDAY WITH EASTERLY FLOW HOLDING HIGHS MAINLY IN THE 40S TO AROUND 50. TEMPS UNCERTAIN ON THURSDAY...BUT IF WE CAN WARM SECTOR SOME OF THE AREA COULD BREAK INTO THE 60S BY LATE IN THE DAY. FRIDAY THROUGH SUNDAY... OVERALL WEATHER LOOKS RATHER SEASONABLE OVER THIS TIME FRAME. A FEW SHORTWAVES MAY BRING A COUPLE OF SPOT SHOWERS..BUT MUCH OF THIS PERIOD WILL PROBABLY END UP DRY. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH MONDAY NIGHT/...HIGH CONFIDENCE THROUGH OVERNIGHT TONIGHT... SCT SHOWERS WILL DISSIPATE ACROSS SE MA AND RI. OTHERWISE...VFR CONDITIONS EXPECTED. SOME NNW WIND GUSTS TO 20 KT DEVELOPING ACROSS E COASTAL MA AND CAPE COD LATE TONIGHT. MON AND MON NIGHT... MAINLY VFR DURING THE DAY. WINDS ONCE AGAIN SHIFT TO THE NE...WHICH LOOKS TO ALLOW ANOTHER ROUND OF MVFR CIGS /ESPECIALLY E OF THE WORCESTER HILLS AND MONADNOCKS/ DURING THE OVERNIGHT HOURS. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...TUESDAY THROUGH FRIDAY... TUESDAY AND TUESDAY NIGHT...MODERATE CONFIDENCE. VFR TO MVFR CEILINGS EXPECTED AT TIMES. WEDNESDAY AND THURSDAY...MODERATE CONFIDENCE. PERIODS OF MVFR-IFR CONDITIONS IN RAIN...LOWER CLOUDS AND FOG PATCHES. FRIDAY...LOW TO MODERATE CONFIDENCE. VFR CONDITIONS DOMINATE. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. THROUGH TOMORROW NIGHT...HIGH CONFIDENCE. MAINLY QUIET BOATING WEATHER THIS EVENING WILL GIVE WAY TO INCREASING NW WINDS AND SEAS ON THE ERN OCEAN WATERS. SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED AS WINDS REACH AROUND 25 KT AT TIMES AND SEAS OF 5-6 FT ARE POSSIBLE. ALTHOUGH THE WINDS WILL DIMINISH AS THEY SHIFT BACK TO THE NE DURING THE DAY TOMORROW...A BUILDING SWELL MAY REQUIRE THAT THIS ERN SCA CONTINUE THROUGH MUCH OF THE DAY TOMORROW. BY TOMORROW NIGHT...ONCE E-NE WINDS HAVE DEVELOPED ANOTHER THREAT FOR GUSTS TO AROUND 25 KT AND CONTINUED BUILDING ELY SWELL MAY NEED A MORE WIDESPREAD SCA FOR THE NEAR COASTAL WATERS AS WELL AS SOME OF THE S COASTAL WATERS. OUTLOOK...TUESDAY INTO FRIDAY... TUESDAY AND WEDNESDAY...MODERATE TO HIGH CONFIDENCE. HIGH PRESSURE OVER EASTERN CANADA AND LOW PRESSURE WELL TO OUR WEST WILL RESULT IN AN INCREASING PRESSURE GRADIENT. EAST TO NORTHEAST WIND GUSTS OF 25 TO 30 KNOTS ARE EXPECTED OVER THE OPEN WATERS MUCH OF THIS TIME. IN ADDITION...LONG EAST FETCH WILL BUILD SEAS WELL ABOVE SCA THRESHOLDS. MOST OF THE RAIN AND FOG SHOULD HOLD OFF UNTIL WED/WED NIGHT. THURSDAY...MODERATE CONFIDENCE. WINDS GRADUALLY TURN SOUTH ON THURSDAY AS AREA ENTERS THE WARM SECTOR...BUT MAY TAKE UNTIL LATE THU/THU NIGHT ACROSS THE NORTHERN WATERS. SCA WIND GUSTS STILL POSSIBLE...ALONG WITH SHOWERS AND AREAS OF FOG. SEAS WILL REMAIN HIGH ACROSS THE OPEN WATERS. FRIDAY...LOW CONFIDENCE. SCA SEAS LINGER AT LEAST OVER THE OUTER- WATERS BUT WIND SPEEDS/DIRECTION VERY UNCERTAIN. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 5 PM EDT MONDAY FOR ANZ250- 254-255. && $$ SYNOPSIS...FRANK/DOODY NEAR TERM...KJC SHORT TERM...DOODY LONG TERM...FRANK AVIATION...FRANK/DOODY MARINE...FRANK/DOODY
AREA FORECAST DISCUSSION
NWS ALBANY NY
157 PM EDT SAT APR 26 2014 .SYNOPSIS... A COMPLEX LOW PRESSURE SYSTEM WILL IMPACT OUR REGION THIS AFTERNOON...AS IT SLOWLY DRIFTS NORTHEAST. AN UPPER LEVEL LOW WILL IMPACT THE REGION TONIGHT INTO TOMORROW BRINGING ANOTHER PERIOD OF RAIN SHOWERS. DRIER WEATHER AND MILDER TEMPERATURES WILL RETURN BY MONDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1058 AM EDT...THE OCCLUDED FRONT ASSOCIATED WITH THE DOUBLE BARREL LOW PRESSURE SYSTEM HAS MOVED THROUGH THE ERN PORTION OF THE FCST AREA LATE MORNING. A FEW LINGERING SHOWERS/DRIZZLE ARE LINGERING OVER THE SRN GREENS AND BERKSHIRES. THE SATELLITE PICTURE IS SHOWING SOME CLEARING OVER CNTRL AND SRN NY. THIS SHOULD MAKE ITS WAY INTO THE SRN PORTIONS OF THE FCST AREA FOR THE EARLY PM WITH SOME PARTIAL SUNSHINE. A BATCH OF SHOWERS AHEAD OF THE CLOSED UPPER LEVEL LOW OVER GEORGIAN BAY/SE ONTARIO ACCORDING TO THE RUC40/RR WILL BRING SHOWERS BACK INTO THE FCST AREA IN THE MID TO LATE PM. THERE COULD BE A FEW RUMBLES OF THUNDER OVER THE SE EXTREME /ULSTER...DUTCHESS...AND LITCHFIELD COUNTIES/. THE LAPSE RATES STEEPEN...AND THERE ARE SMALL AMOUNTS OF INSTABILITY FORECASTED /LESS 250 J/KG/. A SLIGHT CHC OF TSRAS WAS ADDED THERE. THE LATEST HRRR 3-KM COLUMNAR REF PRODUCT INDICATES THE THREAT FOR SHOWERS INCREASES OVER THE MAJORITY OF THE FCST AREA BTWN 20Z-23Z. POPS WERE KEPT IN THE HIGH CHC AND LIKELY CATEGORY. HIGHS TODAY ARE EXPECTED TO BE A TAD ON THE COOL SIDE MAINLY RANGING FROM THE UPPER 40S OVER THE SRN DACKS TO L60S IN THE MID HUDSON VALLEY. TEMPS WERE LOWERED INTO THE U40S TO L50S OVER PORTIONS OF THE SRN GREENS/NRN BERKS WHERE THE CLOUDS MAY LINGER THE LONGEST IN THE RAIN COOLED AIR. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... THE UPPER LEVEL LOW IS CENTERED OVER THE FA THIS EVENING WITH A STRONG VORT LOBE PASSING ACRS THE FA AS WELL. THIS SHOULD RESULT IN MORE SHOWERS WHICH WILL LINGER INTO SUNDAY MORNING AS THE VORT LOBE DOES NOT DRIFT OFF THE EAST COAST UNTIL SUNDAY AFTERNOON. THUS EXPECT THE SECOND HALF OF SUNDAY TO BE DRIER THAN THE FIRST HALF OF THE DAY. EXPECT LOWS TONIGHT IN THE 30S WITH THE HIGHS ON SUNDAY IN THE UPPER 40S NORTHWEST TO AROUND 60 SOUTHEAST. HIGH PRESSURE WILL BUILD INTO THE FA FOR LATER SUNDAY NIGHT INTO MONDAY WITH MAINLY DRY CONDITIONS. LOWS SUNDAY NIGHT WILL BE IN THE UPPER 20S NORTHWEST TO MID 30S SOUTHEAST. HIGHS ON MONDAY ARE EXPECTED TO BE MILDER THAN OVER THE WEEKEND WITH HIGHS RANGING FROM THE MID 50S NORTHWEST TO MID 60S SOUTHEAST. MONDAY NIGHT WILL FEATURE INCREASING CLOUDS AS A STORM SYSTEM APPROACHES FROM THE GREAT LAKES REGION. EXPECT LOWS TO BE IN THE MID 30S TO MID 40S. && .LONG TERM /TUESDAY THROUGH SATURDAY/... UNSETTLED CONDITIONS APPEAR TO DOMINATE MUCH OF THE LONG TERM PERIOD...ALTHOUGH THERE REMAINS SOME UNCERTAINTY AS TO HOW FAST THIS UNSETTLED WEATHER DEVELOPS...AND HOW LONG IT WILL LINGER. MOST 00Z/26 DETERMINISTIC AND ENSEMBLE GUIDANCE INDICATE A RATHER BLOCKY PATTERN IN PLACE AT THE START OF THE LONG TERM PERIOD...WITH A SPRAWLING MID/UPPER LEVEL LOW ACROSS THE CENTRAL U.S...WITH ANOTHER CLOSED MID/UPPER LEVEL LOW MOVING EAST WELL OFF THE NEW ENGLAND COAST. IN BETWEEN THESE TWO FEATURES WILL BE A STRONG BUT SOMEWHAT NARROW RIDGE OF HIGH PRESSURE. THIS RIDGE MAY THWART THE EAST/NORTHEAST PROGRESS OF THE RAIN INITIALLY INTO THE REGION...BEFORE RAIN CHANCES ARE MAXIMIZED AROUND THE LATE WED-EARLY THU TIME PERIOD. TEMPS SHOULD REMAIN BELOW SEASONAL LEVELS GIVEN THE PROSPECTS FOR CLOUDS...AND AT LEAST SOME RAINFALL DURING THE PERIOD. THE STEADIEST RAINFALL MAY LIFT N AND E OF THE REGION BY LATE THU OR FRI...TRANSITIONING TO A MORE SHOWERY REGIME AS THE LINGERING MID/UPPER LEVEL COLD POOL MOVES CLOSER TO THE REGION. HERE ARE SOME MORE SPECIFICS... TUE-TUE NT...AS MENTIONED ABOVE...THERE REMAINS SOME QUESTION AS TO HOW FAST THE MID/UPPER LEVEL RIDGE AXIS MOVES E OF THE REGION...ALLOWING FOR INCREASING ISENTROPIC LIFT AND RAINFALL ACROSS THE REGION. AT THIS TIME...WILL SIDE ON THE SLOWER SIDE OF GUIDANCE...KEEPING MOST AREAS DRY TUE AM...THEN SLOWLY INCREASING POPS INTO THE SLIGHT CHC RANGE FOR EASTERN AREAS...AND LOW CHC RANGE FOR CENTRAL AND WESTERN AREAS BY LATE TUE. FOR TUE NT...WILL CONTINUE TO INCREASE POPS GRADUALLY INTO THE HIGHER CHC RANGE. AS FOR TEMPS...SIDING ON THE SLOWER SIDE OF GUIDANCE...HAVE INDICATED SLIGHTLY WARMER MAX TEMPS FOR TUE...WITH 50S IN MOST AREAS...WITH PERHAPS EVEN SOME LOWER 60S POSSIBLE ACROSS NORTHERN VALLEY AREAS SHOULD THE RAIN HOLD OFF AND ANY MORNING SUNSHINE OCCUR. EXPECT LOWER 40S IN VALLEYS...AND 35-40 ACROSS HIGHER ELEVATIONS AND NORTHERN AREAS FOR TUE NT. WED-THU...CHC POPS EARLY WED HAVE BEEN RAISED TO LIKELY POPS FOR LATE WED INTO EARLY THU...WHICH APPEARS TO BE THE BEST OPPORTUNITY FOR WIDESPREAD RAINFALL GIVEN THE GREATEST ISENTROPIC LIFT AND MOISTURE TRANSPORT INTO AND ACROSS THE REGION. THE 00Z/26 GEFS ACTUALLY HINT AT SOME CHC FOR HEAVY RAIN ACROSS PORTIONS OF THE MID HUDSON VALLEY AND NW CT...WHERE THE PROB FOR ONE INCH OR GREATER OVER A 24 HOUR PERIOD IS IN THE 40-60 PERCENT RANGE THROUGH 18Z/THU...WITH EVEN A 20-40 PERCENT CHANCE FOR 2 INCHES OR MORE OVER A 36 HOUR PERIOD ALSO ENDING 18Z/THU. EXPECT MAX TEMPS TO MAINLY REMAIN IN THE LOWER/MID 50S...WITH SOME UPPER 40S POSSIBLE IN HIGHER ELEVATIONS WED. BY LATE THU...IT IS POSSIBLE THAT THE STEADIEST RAIN BEGINS TO TAPER TO SHOWERS. HAVE INDICATED SLIGHTLY WARMER MAXES COMPARED TO WED...WITH 50S AND LOWER 60S IN VALLEYS. WED NT/THU AM MINS SHOULD MAINLY BE IN THE 40S...WITH SOME 30S POSSIBLE ACROSS HIGHER ELEVATIONS. THU NT-FRI...THE BEST FORCING APPEARS TO SHIFT MAINLY N AND E OF THE REGION. HOWEVER...WITH THE APPROACH OF THE LINGERING MID LEVEL COLD POOL...EXPECT AT LEAST SOME ISOLATED TO SCATTERED RAIN SHOWERS TO OCCUR...ESP DURING FRI AFTN. MAX TEMPS SHOULD REACH THE LOWER 60S IN VALLEYS...WITH 50S ACROSS MOST HIGHER ELEVATIONS. THU NT/FRI AM MINS SHOULD FALL INTO THE 40S IN VALLEYS...AND MID 30S TO NEAR 40 ACROSS NORTHERN AREAS...AND HIGHER TERRAIN. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... A STRONG UPPER LEVEL DISTURBANCE ASSOCIATED WITH A CLOSED UPPER LEVEL APPROACHING FROM SE ONTARIO WILL BRING SHOWERS BACK INTO THE ERN NY AND WRN NEW ENGLAND TERMINALS LATE THIS AFTERNOON INTO THIS EVENING. THE UPPER LEVEL LOW WILL MOVE EAST TO SOUTHEAST OF NEW ENGLAND ON SUNDAY WITH LINGERING CLOUDS AND ISO-SCT SHOWERS AROUND THROUGH THE MORNING. VFR CONDITIONS WILL BE SHORT-LIVED FOR KALB/KPOU/KGFL/KPSF IN THE EARLY TO MID PM...BEFORE THE NEXT ROUND OF SHOWERS ARRIVES. THERE MAY EVEN BE A RUMBLE OF THUNDER AROUND NEAR KPOU...BUT THE PROBABILITY WAS NOT GREAT ENOUGH TO INCLUDE IN THE TERMINALS. THE SHOWERS ARRIVE BTWN 20Z-22Z...AND LINGER UNTIL 02Z-05Z/SUN. CIGS AND VSBYS WILL GENERALLY BE IN THE MVFR RANGE...BUT IFR CIGS/VSBYS WERE INCLUDED AT KPSF...ESPECIALLY FOR LOW STRATUS IN THE SHOWERS PRIOR TO MIDNIGHT. THE RESIDUAL LOW-LEVEL MOISTURE SHOULD LAST IN THE BOUNDARY LAYER THROUGH THE OVERNIGHT PERIOD THERE...AND THE IFR CIGS WERE KEPT IN THERE UNTIL 13Z/SUN. ELSEWHERE...MVFR CIGS IN THE MOIST CYCLONIC FLOW WERE KEPT IN THE FCST FOR KGFL/KALB THROUGH OVERNIGHT. KPOU SHOULD HAVE ENOUGH DRY AIR FILTERING IN TO HAVE CIGS RISE TO THE VFR LEVELS BY 07Z/SUN. CIGS WILL GENERALLY BE IN THE HIGH MVFR/VFR LEVELS BY 13Z-15Z/SUN AT ALL THE TERMINALS WITH ISOLD-SCT INSTABILITY SHOWERS IN THE VICINITY. THE WINDS WILL VARY FROM THE SW TO N AT LESS THAN 10 KTS THIS AFTERNOON...THEN EXPECT A WIND SHIFT TO THE W TO NW AT 5-10 KTS WITH THE UPPER LEVEL DISTURBANCE MOVING ACROSS THE REGION. N TO NW WINDS WILL PERSIST OVERNIGHT INTO TOMORROW MORNING AT 10 KTS OR LESS. OUTLOOK... SUNDAY PM TO MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. WEDNESDAY-THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. && .FIRE WEATHER... A SOAKING RAIN OCCURRED OVERNIGHT ACROSS EASTERN NEW YORK AND ADJACENT WESTERN NEW ENGLAND ALLEVIATING ANY FIRE WEATHER CONCERNS FOR THE TIME BEING. RELATIVE HUMIDITY VALUES WILL ONLY DROP TO 45 TO 60 PERCENT THIS AFTERNOON...RECOVER TO 70 TO 100 PERCENT TONIGHT AND FALL TO 35 TO 55 PERCENT ON SUNDAY. WINDS WILL BE SOUTHEAST TO NORTHEAST AT 5 TO 10 MPH TODAY...WEST TO NORTHWEST AT 5 TO 10 MPH TONIGHT...AND NORTHWEST AT 10 TO 15 MPH WITH GUSTS TO 25 MPH SUNDAY AFTERNOON. && .HYDROLOGY... NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED DURING THE NEXT FIVE DAYS. SHOWERS OVERNIGHT HAVE BROUGHT MOST AREAS A QUARTER TO HALF AN INCH WITH MORE RAIN SHOWERS EXPECTED LATER TODAY INTO TONIGHT WITH ANOTHER TENTH TO THIRD OF AN INCH EXPECTED. ANY PRECIPITATION WILL END BY SUNDAY AFTERNOON FOLLOWED BY DRY WEATHER THROUGH MONDAY NIGHT. THE NEXT CHANCE OF PCPN WILL COME DURING THE MID WEEK PERIOD. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...11/WASULA NEAR TERM...KL/11/WASULA SHORT TERM...11 LONG TERM...KL AVIATION...WASULA FIRE WEATHER...11 HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
1059 AM EDT SAT APR 26 2014 .SYNOPSIS... A COMPLEX LOW PRESSURE SYSTEM WILL IMPACT OUR REGION THIS AFTERNOON...AS IT SLOWLY DRIFTS NORTHEAST. AN UPPER LEVEL LOW WILL IMPACT THE REGION TONIGHT INTO TOMORROW BRINGING ANOTHER PERIOD OF RAIN SHOWERS. DRIER WEATHER AND MILDER TEMPERATURES WILL RETURN BY MONDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1058 AM EDT...THE OCCLUDED FRONT ASSOCIATED WITH THE DOUBLE BARREL LOW PRESSURE SYSTEM HAS MOVED THROUGH THE ERN PORTION OF THE FCST AREA LATE MORNING. A FEW LINGERING SHOWERS/DRIZZLE ARE LINGERING OVER THE SRN GREENS AND BERKSHIRES. THE SATELLITE PICTURE IS SHOWING SOME CLEARING OVER CNTRL AND SRN NY. THIS SHOULD MAKE ITS WAY INTO THE SRN PORTIONS OF THE FCST AREA FOR THE EARLY PM WITH SOME PARTIAL SUNSHINE. A BATCH OF SHOWERS AHEAD OF THE CLOSED UPPER LEVEL LOW OVER GEORGIAN BAY/SE ONTARIO ACCORDING TO THE RUC40/RR WILL BRING SHOWERS BACK INTO THE FCST AREA IN THE MID TO LATE PM. THERE COULD BE A FEW RUMBLES OF THUNDER OVER THE SE EXTREME /ULSTER...DUTCHESS...AND LITCHFIELD COUNTIES/. THE LAPSE RATES STEEPEN...AND THERE ARE SMALL AMOUNTS OF INSTABILITY FORECASTED /LESS 250 J/KG/. A SLIGHT CHC OF TSRAS WAS ADDED THERE. THE LATEST HRRR 3-KM COLUMNAR REF PRODUCT INDICATES THE THREAT FOR SHOWERS INCREASES OVER THE MAJORITY OF THE FCST AREA BTWN 20Z-23Z. POPS WERE KEPT IN THE HIGH CHC AND LIKELY CATEGORY. HIGHS TODAY ARE EXPECTED TO BE A TAD ON THE COOL SIDE MAINLY RANGING FROM THE UPPER 40S OVER THE SRN DACKS TO L60S IN THE MID HUDSON VALLEY. TEMPS WERE LOWERED INTO THE U40S TO L50S OVER PORTIONS OF THE SRN GREENS/NRN BERKS WHERE THE CLOUDS MAY LINGER THE LONGEST IN THE RAIN COOLED AIR. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... THE UPPER LEVEL LOW IS CENTERED OVER THE FA THIS EVENING WITH A STRONG VORT LOBE PASSING ACRS THE FA AS WELL. THIS SHOULD RESULT IN MORE SHOWERS WHICH WILL LINGER INTO SUNDAY MORNING AS THE VORT LOBE DOES NOT DRIFT OFF THE EAST COAST UNTIL SUNDAY AFTERNOON. THUS EXPECT THE SECOND HALF OF SUNDAY TO BE DRIER THAN THE FIRST HALF OF THE DAY. EXPECT LOWS TONIGHT IN THE 30S WITH THE HIGHS ON SUNDAY IN THE UPPER 40S NORTHWEST TO AROUND 60 SOUTHEAST. HIGH PRESSURE WILL BUILD INTO THE FA FOR LATER SUNDAY NIGHT INTO MONDAY WITH MAINLY DRY CONDITIONS. LOWS SUNDAY NIGHT WILL BE IN THE UPPER 20S NORTHWEST TO MID 30S SOUTHEAST. HIGHS ON MONDAY ARE EXPECTED TO BE MILDER THAN OVER THE WEEKEND WITH HIGHS RANGING FROM THE MID 50S NORTHWEST TO MID 60S SOUTHEAST. MONDAY NIGHT WILL FEATURE INCREASING CLOUDS AS A STORM SYSTEM APPROACHES FROM THE GREAT LAKES REGION. EXPECT LOWS TO BE IN THE MID 30S TO MID 40S. && .LONG TERM /TUESDAY THROUGH FRIDAY/... UNSETTLED CONDITIONS APPEAR TO DOMINATE MUCH OF THE LONG TERM PERIOD...ALTHOUGH THERE REMAINS SOME UNCERTAINTY AS TO HOW FAST THIS UNSETTLED WEATHER DEVELOPS...AND HOW LONG IT WILL LINGER. MOST 00Z/26 DETERMINISTIC AND ENSEMBLE GUIDANCE INDICATE A RATHER BLOCKY PATTERN IN PLACE AT THE START OF THE LONG TERM PERIOD...WITH A SPRAWLING MID/UPPER LEVEL LOW ACROSS THE CENTRAL U.S...WITH ANOTHER CLOSED MID/UPPER LEVEL LOW MOVING EAST WELL OFF THE NEW ENGLAND COAST. IN BETWEEN THESE TWO FEATURES WILL BE A STRONG BUT SOMEWHAT NARROW RIDGE OF HIGH PRESSURE. THIS RIDGE MAY THWART THE EAST/NORTHEAST PROGRESS OF THE RAIN INITIALLY INTO THE REGION...BEFORE RAIN CHANCES ARE MAXIMIZED AROUND THE LATE WED-EARLY THU TIME PERIOD. TEMPS SHOULD REMAIN BELOW SEASONAL LEVELS GIVEN THE PROSPECTS FOR CLOUDS...AND AT LEAST SOME RAINFALL DURING THE PERIOD. THE STEADIEST RAINFALL MAY LIFT N AND E OF THE REGION BY LATE THU OR FRI...TRANSITIONING TO A MORE SHOWERY REGIME AS THE LINGERING MID/UPPER LEVEL COLD POOL MOVES CLOSER TO THE REGION. HERE ARE SOME MORE SPECIFICS... TUE-TUE NT...AS MENTIONED ABOVE...THERE REMAINS SOME QUESTION AS TO HOW FAST THE MID/UPPER LEVEL RIDGE AXIS MOVES E OF THE REGION...ALLOWING FOR INCREASING ISENTROPIC LIFT AND RAINFALL ACROSS THE REGION. AT THIS TIME...WILL SIDE ON THE SLOWER SIDE OF GUIDANCE...KEEPING MOST AREAS DRY TUE AM...THEN SLOWLY INCREASING POPS INTO THE SLIGHT CHC RANGE FOR EASTERN AREAS...AND LOW CHC RANGE FOR CENTRAL AND WESTERN AREAS BY LATE TUE. FOR TUE NT...WILL CONTINUE TO INCREASE POPS GRADUALLY INTO THE HIGHER CHC RANGE. AS FOR TEMPS...SIDING ON THE SLOWER SIDE OF GUIDANCE...HAVE INDICATED SLIGHTLY WARMER MAX TEMPS FOR TUE...WITH 50S IN MOST AREAS...WITH PERHAPS EVEN SOME LOWER 60S POSSIBLE ACROSS NORTHERN VALLEY AREAS SHOULD THE RAIN HOLD OFF AND ANY MORNING SUNSHINE OCCUR. EXPECT LOWER 40S IN VALLEYS...AND 35-40 ACROSS HIGHER ELEVATIONS AND NORTHERN AREAS FOR TUE NT. WED-THU...CHC POPS EARLY WED HAVE BEEN RAISED TO LIKELY POPS FOR LATE WED INTO EARLY THU...WHICH APPEARS TO BE THE BEST OPPORTUNITY FOR WIDESPREAD RAINFALL GIVEN THE GREATEST ISENTROPIC LIFT AND MOISTURE TRANSPORT INTO AND ACROSS THE REGION. THE 00Z/26 GEFS ACTUALLY HINT AT SOME CHC FOR HEAVY RAIN ACROSS PORTIONS OF THE MID HUDSON VALLEY AND NW CT...WHERE THE PROB FOR ONE INCH OR GREATER OVER A 24 HOUR PERIOD IS IN THE 40-60 PERCENT RANGE THROUGH 18Z/THU...WITH EVEN A 20-40 PERCENT CHANCE FOR 2 INCHES OR MORE OVER A 36 HOUR PERIOD ALSO ENDING 18Z/THU. EXPECT MAX TEMPS TO MAINLY REMAIN IN THE LOWER/MID 50S...WITH SOME UPPER 40S POSSIBLE IN HIGHER ELEVATIONS WED. BY LATE THU...IT IS POSSIBLE THAT THE STEADIEST RAIN BEGINS TO TAPER TO SHOWERS. HAVE INDICATED SLIGHTLY WARMER MAXES COMPARED TO WED...WITH 50S AND LOWER 60S IN VALLEYS. WED NT/THU AM MINS SHOULD MAINLY BE IN THE 40S...WITH SOME 30S POSSIBLE ACROSS HIGHER ELEVATIONS. THU NT-FRI...THE BEST FORCING APPEARS TO SHIFT MAINLY N AND E OF THE REGION. HOWEVER...WITH THE APPROACH OF THE LINGERING MID LEVEL COLD POOL...EXPECT AT LEAST SOME ISOLATED TO SCATTERED RAIN SHOWERS TO OCCUR...ESP DURING FRI AFTN. MAX TEMPS SHOULD REACH THE LOWER 60S IN VALLEYS...WITH 50S ACROSS MOST HIGHER ELEVATIONS. THU NT/FRI AM MINS SHOULD FALL INTO THE 40S IN VALLEYS...AND MID 30S TO NEAR 40 ACROSS NORTHERN AREAS...AND HIGHER TERRAIN. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... MVFR/IFR CONDITIONS...WITH THE IFR MAINLY FOR CIGS...WILL PERSIST AT THE TAF SITES THROUGH AROUND 13Z-14Z...AS AN OCCLUDED FRONT PASSES EASTWARD...AND RAIN/DRIZZLE OCCURS. IN ITS WAKE...THE RAIN SHOULD END...AND CIGS SHOULD LIFT INTO THE MVFR...THEN VFR RANGE BY MID MORNING. A LULL IN THE RAIN IS THEN EXPECTED THROUGH EARLY AFTERNOON. THEN...AS A POTENT UPPER LEVEL DISTURBANCE APPROACHES FROM THE WEST...SHOWERS WILL DEVELOP/INCREASE IN AREAL COVERAGE ONCE AGAIN...ESP FROM THE KALB SOUTH TO KPOU AND EAST TO KPSF DURING THE MID TO LATE AFTERNOON HOURS. SOME LOCALLY HEAVY SHOWERS COULD BRIEFLY OCCUR...AND CAN NOT EVEN RULE OUT AN ISOLATED THUNDERSTORM. HOWEVER...OVERALL CONFIDENCE IN THREAT FOR THUNDER IS VERY LOW AT THIS TIME...SO NO MENTION OF TSRA IN CURRENT TAF ISSUANCES. ANY HEAVIER SHOWERS COULD LEAD TO BRIEF AND LOCALIZED MVFR/IFR VSBYS. SHOWERS SHOULD DECREASE IN AREAL COVERAGE TONIGHT. HOWEVER...SOME MVFR CIGS MAY PERSIST AT KGFL/KPSF/KALB. WINDS AHEAD OF THE OCCLUDED FRONT WILL BE MAINLY LIGHT AND VARIABLE...EXCEPT FROM THE SOUTH TO SOUTHEAST AT KALB AT 5-10 KT. WINDS WILL THEN SHIFT INTO THE WEST TO SOUTHWEST BY MID MORNING AT 5-10 KT IN THE WAKE OF THIS FRONT...WITH SOME GUSTS POSSIBLY REACHING 20 KT AT TIMES...ESP AT KALB AND KPSF. WINDS WILL SHIFT INTO THE NORTHWEST TO NORTH TONIGHT AT GENERALLY 5-10 KT. OUTLOOK... SUNDAY TO MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. && .FIRE WEATHER... A SOAKING RAIN OCCURRED OVERNIGHT ACROSS EASTERN NEW YORK AND ADJACENT WESTERN NEW ENGLAND ALLEVIATING ANY FIRE WEATHER CONCERNS FOR THE TIME BEING. RELATIVE HUMIDITY VALUES WILL ONLY DROP TO 45 TO 60 PERCENT THIS AFTERNOON...RECOVER TO 70 TO 100 PERCENT TONIGHT AND FALL TO 35 TO 55 PERCENT ON SUNDAY. WINDS WILL BE SOUTHEAST TO NORTHEAST AT 5 TO 10 MPH TODAY...WEST TO NORTHWEST AT 5 TO 10 MPH TONIGHT...AND NORTHWEST AT 10 TO 15 MPH WITH GUSTS TO 25 MPH SUNDAY AFTERNOON. && .HYDROLOGY... NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED DURING THE NEXT FIVE DAYS. SHOWERS OVERNIGHT HAVE BROUGHT MOST AREAS A QUARTER TO HALF AN INCH WITH MORE RAIN SHOWERS EXPECTED LATER TODAY INTO TONIGHT WITH ANOTHER TENTH TO THIRD OF AN INCH EXPECTED. ANY PRECIPITATION WILL END BY SUNDAY AFTERNOON FOLLOWED BY DRY WEATHER THROUGH MONDAY NIGHT. THE NEXT CHANCE OF PCPN WILL COME DURING THE MID WEEK PERIOD. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...11/WASULA NEAR TERM...KL/11/WASULA SHORT TERM...11 LONG TERM...KL AVIATION...KL/WASULA FIRE WEATHER...11 HYDROLOGY...11
AREA FORECAST DISCUSSION...UPDATED
NWS TAMPA BAY RUSKIN FL
859 PM EDT SUN APR 27 2014 .UPDATE...LOOKING LESS AND LESS LIKELY WE ARE GOING TO SEE MUCH SEA BREEZE ACTIVITY EVEN WITH THE COLLISION ACROSS THE SPINE...BUT WILL LEAVE A 10-20 POP IN FOR NEXT FEW HOURS ACROSS INTERIOR COUNTIES (LOWERING FROM 30-40 PERCENT)...AS THE HRRR STILL TRIES TO GENERATE A FEW SHRA. OTHERWISE...WILL JUST SEE QUITE A BIT OF CIRRUS STREAM ACROSS THE REGION OVERNIGHT WITH LITTLE SIGNIFICANT WEATHER FOR CEN FL. REMAINDER OF FORECAST ON TRACK AND NO ADDITIONAL CHANGES PLANNED. && .AVIATION...NO SIGNIFICANT AVIATION ISSUES ANTICIPATED. PROBABILITY OF MVFR VSBY AROUND SUNRISE FOR LAL AND PGD IS NOT HIGH ENOUGH TO INCLUDE IN TAFS. PROBABILITY OF SHRA LATE MON AFTERNOON (MAINLY INLAND LAL AREA) ALSO TO LOW TO INCLUDE IN TAFS. THEREFORE...SHOWING VFR CONDITIONS THROUGH THE PERIOD. && .PREV DISCUSSION... /ISSUED 321 PM EDT SUN APR 27 2014/ ..THUNDERSTORMS POSSIBLE THIS AFTERNOON ACROSS PORTIONS OF CENTRAL FLORIDA... SHORT TERM (TODAY THROUGH TONIGHT)... WEST COAST SEA BREEZE CONTINUES TO MARCH INLAND THIS AFTERNOON...ALREADY REACHING THE INTERSTATE 75 CORRIDOR ACROSS MUCH OF WEST CENTRAL AND SOUTHWEST FLORIDA. THE EAST COAST SEA BREEZE CONTINUES ITS MARCH INLAND NEAR THE TURNPIKE CORRIDOR...NEARING PORTIONS OF METRO ORLANDO TO THE NORTH AND EASTERN LAKE OKEECHOBEE TO THE SOUTH. VISIBLE SATELLITE IMAGERY ALSO SHOWS A LAKE SHADOW...WITH THE BREAK IN CLOUDS OVER PORTIONS OF GLADES...HIGHLANDS...AND OKEECHOBEE COUNTIES. EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP THIS AFTERNOON AND EVENING AS THESE BOUNDARIES COLLIDE...MAINLY FROM SUMTER/LAKE COUNTIES DOWN INTO POLK COUNTY. A POTENTIAL EXISTS FOR SOME ISOLATED STRONG THUNDERSTORMS THAT COULD PRODUCE HAIL AND STRONG WINDS. ACTIVITY THAT DEVELOPS ON THE NORTHERN PARTS OF THE BOUNDARY WILL SPREAD SOUTH THIS EVENING BEFORE DIMINISHING AFTER SUNSET. REMNANT CLOUDS OVERNIGHT WILL HELP TO KEEP MUCH OF THE AREA IN THE 60S. MOS GUIDANCE TEMPERATURE SPREAD WAS MINIMAL...PREFERRED A BLEND. FOR POPS...PREFERRED LOCAL HIGH RESOLUTION MODELING INSTEAD OF THE MOS GUIDANCE. MID TERM (MONDAY THROUGH TUESDAY)... VERY LITTLE CHANGE IN FORECAST PHILOSOPHY WITH THIS ISSUANCE. 02/GARCIA /ISSUED AT 547 AM EDT SUN APR 27 2014/ RIDGING WILL BE IN PLACE ACROSS FLORIDA BOTH AT THE SURFACE AND ALOFT ON MONDAY. THE SURFACE RIDGE WILL BE CENTERED WELL TO THE EAST OF THE STATE WITH PREDOMINANT SOUTHEASTERLY FLOW ACROSS THE REGION. A SEA BREEZE WILL DEVELOP BY LATE MORNING AND MOVE STEADILY INLAND DURING THE AFTERNOON. LOW-LEVEL MOISTURE WILL BE MEAGER...BUT PERHAPS ENOUGH FOR A FEW SHOWERS INLAND. IT WILL BE QUITE WARM AND RELATIVELY HUMID WITH TEMPERATURES TOPPING 90 DEGREES FOR MUCH OF THE REGION EAST OF I-75. BY TUESDAY...A LARGE UPPER-LEVEL TROUGH WILL BE APPROACHING FROM THE NORTHWEST. THE MID-LEVEL RIDGE WILL BE DISPLACED SOUTH AND EAST...BUT THE SURFACE RIDGE WILL CONTINUE FROM THE ATLANTIC WESTWARD ACROSS THE STATE. THE IMPACT FROM THE APPROACHING TROUGH WILL LIKELY REMAIN TO OUR NORTHWEST ON TUESDAY...BUT WE COULD ONCE AGAIN SEE A FEW SHOWERS OVER THE INTERIOR WITH COLLIDING SEA BREEZES. TEMPERATURES WILL AGAIN TOP 90 DEGREES EAST OF I-75. LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)... /ISSUED AT 547 AM EDT SUN APR 27 2014/ MODELS CONTINUE TO SHOW A BROAD UPPER-LEVEL TROUGH OF LOW PRESSURE SETTING UP ACROSS THE EASTERN TWO THIRDS OF THE U.S. THROUGH SUNDAY. MODELS ARE SURPRISINGLY SIMILAR WITH FEATURES IN THE UPPER-LEVELS...BUT DIFFER CONSIDERABLY WITH AN ASSOCIATED WEAK SURFACE FRONTAL BOUNDARY AND ITS EVENTUAL IMPACTS ON THE REGION. THE MOST LIKELY SCENARIO IS THAT CLOUDS WILL INCREASE AHEAD OF THE SYSTEM ON WEDNESDAY WITH RAIN CHANCES INCREASING FROM NORTH TO SOUTH WEDNESDAY NIGHT AND THURSDAY. THE SURFACE BOUNDARY WILL LIKELY STALL OVER FLORIDA FOR A TIME BETWEEN THURSDAY AND SATURDAY... THEN MAY BE FINALLY PUSHED SOUTH OF THE REGION FOR SUNDAY. THE ECMWF IS THE SLOWEST WITH THE BOUNDARY AND EVEN THAT MODEL NOW PUSHES MOST OF THE MOISTURE ALONG WITH THE FRONTAL BOUNDARY TO OUR SOUTH FOR SUNDAY. WITH THE CYCLONIC FLOW ALOFT AND A MEANDERING FRONTAL BOUNDARY NEARBY...IT SEEMS PRUDENT TO KEEP AT LEAST SOME MENTION OF RAIN IN THE FORECAST BEGINNING THURSDAY AND CONTINUING THROUGH AT LEAST SATURDAY. AVIATION... VFR EXPECTED THROUGH THE PERIOD...WITH A SEA BREEZE PUSHING INLAND THIS AFTERNOON. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP INLAND OF MOST TERMINALS...LAL COULD SEE THUNDERSTORMS IN THE COMING HOURS. SEA BREEZE WILL RETREAT AFTER SUNSET WITH LIGHT EASTERLY FLOW RETURNING OVERNIGHT. MARINE... CONDITIONS ARE EXPECTED TO REMAIN PLEASANT FOR BOATING AS HIGH PRESSURE RIDGES WEST OVER FLORIDA. BUOY REPORTS CONTINUE TO SHOW A SOUTHEAST WIND IN THE 10 TO 15 KNOT RANGE OUT TO 60 NM...WHILE WINDS CLOSER TO THE COASTLINE HAVE VEERED TO A SOUTHWEST ONSHORE FLOW WITH THE AFTERNOON SEA BREEZE. SEAS WILL REMAIN LESS THAN 2 FEET THROUGH MONDAY. WINDS WILL SLIGHTLY DECREASE OVERNIGHT...BUT WILL THEN AGAIN INCREASE ON MONDAY AND TUESDAY TO THE 10 TO 15 KNOT RANGE WITH SEAS IN THE 1 TO 3 FOOT RANGE. FIRE WEATHER... NO FIRE WEATHER CONCERNS EXPECTED THROUGH MID-WEEK. OVERNIGHT/MORNING FOG POTENTIAL MINIMIZED COMPARED TO PREVIOUS NIGHTS. && .PRELIMINARY POINT TEMPS/POPS... TPA 71 88 72 89 / 0 10 10 0 FMY 71 91 70 91 / 10 20 10 10 GIF 70 91 70 91 / 20 40 10 20 SRQ 69 85 71 87 / 0 10 0 0 BKV 63 90 67 90 / 10 20 10 10 SPG 73 87 73 87 / 0 10 0 0 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE/MARINE...88/GITTINGER AVIATION...88/GITTINGER
AREA FORECAST DISCUSSION
NWS MIAMI FL
116 PM EDT SAT APR 26 2014 .AVIATION... VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST AS HIGH PRESSURE REMAINS THE DOMINANT WEATHER FEATURE. SEA BREEZES WILL BE THE DOMINANT WEATHER MAKER ALONG BOTH COASTS EACH AFTERNOON. THERE COULD BE ONE OR TWO SHOWERS LATE THIS AFTERNOON AS THE BOUNDARIES CONVERGE OVER THE INTERIOR BUT TOO FAR INLAND FROM THE TERMINALS TO PLACE IN THE TAFS. KOB && .PREV DISCUSSION... /ISSUED 947 AM EDT SAT APR 26 2014/ UPDATE... THE CURRENT FORECAST IS ON TRACK. A DRY AND WARM DAY WITH PLENTY OF SUNSHINE IS EXPECTED FOR TODAY. A LARGE AREA OF HIGH PRESSURE IS LOCATED OVER THE GULF OF MEXICO WITH VERY DRY AIR IN PLACE BETWEEN 700 AND 500 MB. LIGHT NORTHERLY WINDS WILL PREVAIL TODAY AND WILL TURN EASTERLY BY SUNDAY MORNING. THIS WILL BRING A LITTLE BIT OF MORE MOISTURE, BUT IT WILL STAY CONFINED TO THE BOUNDARY LAYER. STRONG SUBSIDENCE BELOW 700 MB WILL DELAY ANY SHOWERS THAT MAY FORM OVER LAND UNTIL LATE IN THE DAY. THE MID LEVEL TEMPERATURES ARE STILL RELATIVELY COOL, AROUND -10C, WHICH WILL ALLOW FOR THE FORMATION OF ONE OR TWO LATE AFTERNOON SHOWERS. HOWEVER, IF ANY THING FORMS IT WILL BE VERY SPARSE IN COVERAGE, AND IN THE AREAS WHERE THE EAST COAST AND WEST COAST SEA BREEZES COLLIDE. OVER THE ATLANTIC WATERS WE CAN BEGIN TO OBSERVE THE SET UP OF A CONVERGENCE LINE BETWEEN EASTERLY FLOW SOUTH OF THE PALM BEACH WATERS AND MORE NORTHERLY FLOW TO THE NORTH. THIS COULD TRIGGER A FEW SHOWERS OVER THE PALM BEACH WATERS. COVERAGE WILL BE SPARSE. PREV DISCUSSION... /ISSUED 715 AM EDT SAT APR 26 2014/ AVIATION... DEEP LAYER HIGH PRESSURE WILL DOMINATE SOUTH FLORIDA THROUGH THE FORECAST WITH SEA BREEZES DEVELOPING ALONG BOTH COASTS. SOME OF THE HIGH RESOLUTION SHORT TERM MODELS ARE AGAIN SHOWING A FEW SHOWERS ALONG THE SEA BREEZES OVER THE INTERIOR LATE IN THE AFTERNOON. LEFT OUT OF THE FORECAST FOR NOW AS THESE WILL TOO FEW TO CONSIDER AND MORE THAN LIKELY WELL INLAND AWAY FROM ANY TERMINALS. KOB PREV DISCUSSION... /ISSUED 420 AM EDT SAT APR 26 2014/ DISCUSSION... WATER VAPOR AND RUC ANALYSIS THIS MORNING SHOWED A SHORTWAVE TROUGH FROM THE GREAT LAKES SOUTHEAST TO OFF THE EAST COAST OF NORTH CAROLINA. AN UPPER LEVEL RIDGE STRETCHED FROM THE WESTERN GULF OF MEXICO INTO CANADA...AND ANOTHER SHORTWAVE TROUGH WAS PUSHING INTO CENTRAL CALIFORNIA. A NEARLY ZONAL FLOW WAS NOTED OVER SOUTH FLORIDA. AT THE SURFACE...AN AREA OF LOW PRESSURE WAS LOCATED OVER THE WESTERN ATLANTIC JUST SOUTH OF NEW JERSEY...AND A WEAK FRONTAL BOUNDARY WAS DRAPED SOUTH AND WEST ALONG THE SOUTHEAST STATES COASTS AND INTO SOUTHERN GEORGIA AND ALONG THE NORTHERN GULF COAST. WEAK SURFACE HIGH PRESSURE REMAINED ACROSS FLORIDA AND THE KEYS...WITH A LIGHT NORTHERLY LOW LEVEL FLOW OVER SOUTH FLORIDA. FOR TODAY...DRIER AIR WILL MOVE IN FROM THE WEST...WITH PWATS A LITTLE OVER AN INCH. SO DRY AND WARM CONDITIONS ARE EXPECTED. LIGHT WINDS WILL CONTINUE THIS MORNING...WITH SEA BREEZE BOUNDARIES PUSHING INLAND ALONG BOTH COASTS THIS AFTERNOON. TONIGHT...THE UPPER LEVEL RIDGE OVER THE WESTERN GULF IS FORECAST TO PUSH TOWARDS THE EASTERN GULF AS THE SHORTWAVE OVER CALIFORNIA EJECTS EAST INTO THE INTERMOUNTAIN WEST. THE SURFACE RIDGE OF HIGH PRESSURE OVER THE REGION WILL BEGIN TO SHIFT TO THE EAST INTO THE WESTERN ATLANTIC...WITH EASTERLY FLOW DEVELOPING. LIGHT WINDS ARE FORECAST ACROSS THE INTERIOR...AND PATCHY FOG MAY DEVELOP ONCE AGAIN. AREAS OF SMOKE ARE LIKELY NEAR THE WILDFIRE ACROSS EASTERN COLLIER COUNTY. SUNDAY THROUGH TUESDAY...THE SURFACE RIDGE WILL CONTINUE TO PUSH EAST...AND THE EASTERLY FLOW WILL INCREASE. SEA BREEZE BOUNDARIES ARE FORECAST TO INTERACT ACROSS THE INTERIOR NEAR THE LAKE REGION IN THE AFTERNOON. THIS MAY BE ENOUGH TO SPARK A FEW SHOWERS OR STORMS IN THIS REGION ON SUNDAY. ABOVE NORMAL TEMPERATURES WILL CONTINUE WITH HIGHS IN THE MID 80S TO LOWER 90S. AN UPPER LEVEL LOW WILL CUTOFF ACROSS THE INTERMOUNTAIN WEST AND THE CENTRAL PLAINS SUNDAY...AND THEN MEANDER ACROSS THE CENTRAL PLAINS THROUGH EARLY NEXT WEEK. THE UPPER LEVEL RIDGE WILL MOVE OVER SOUTH FLORIDA ON SUNDAY AND THEN REMAIN THROUGH THE MIDDLE OF THE WEEK. MAINLY DRY AND VERY WARM CONDITIONS WILL CONTINUE. A LARGE UPPER TROUGH/LOW WILL ENVELOP ABOUT THE EASTERN TWO- THIRDS OF THE CONUS WEDNESDAY AND THURSDAY. UPPER HEIGHTS WILL BEGIN TO LOWER...BUT SOME RIDGING WILL REMAIN OVER SOUTH FLORIDA. A COLD FRONT IS FORECAST TO PUSH INTO NORTHERN FLORIDA BY WEDNESDAY EVENING. HOWEVER...THE FRONT IS FORECAST TO REMAIN OVER NORTH OR CENTRAL FLORIDA THROUGH FRIDAY. THE FLOW WILL SHIFT TO THE SOUTHEAST. MOISTURE IS FORECAST TO SLOWLY INCREASE THROUGH THE END OF THE WEEK...AND RAIN CHANCES ARE FORECAST TO INCREASE. DEWPOINTS ARE FORECAST TO INCREASE BACK TO AROUND 70 BY TUESDAY...AND REMAIN AROUND 70 THROUGH THE END OF THE PERIOD. SOUTHEAST WINDS ARE FORECAST TO BE 10-15 KNOTS OVER THE ATLANTIC WATERS AS WELL...AND THIS WILL KEEP LOW TEMPERATURES WELL ABOVE NORMAL FOR THE EAST COAST. OVERNIGHT LOWS ARE FORECAST TO BE IN THE MID/UPPER 70S FOR THE EAST COAST METRO AREAS. HIGHS ARE FORECAST TO BE IN THE MID 80S TO LOW 90S THROUGH THE WEEK. AVIATION... HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER THROUGH THE TAF PERIOD. THIS WILL KEEP VFR CONDITIONS IN PLACE. WINDS WILL PICK UP MID DAY AS THE SEA BREEZE DEVELOPS, THEN RETURN TO LIGHT AND VARIABLE IN THE LATE EVENING HOURS. MARINE... A WEAK PRESSURE GRADIENT PREVAILS ACROSS THE REGIONAL WATERS WITH LIGHT AND SOMEWHAT VARIABLE WINDS TODAY WITH MORE EASTERLY FLOW RETURNING ON SUNDAY INTO EARLY NEXT WEEK. IN GENERAL SEAS ARE EXPECTED TO BE 2 FEET OR LESS THROUGH THE WEEKEND WITH JUST A GRADUAL INCREASE IN WINDS AND SEAS EARLY NEXT WEEK. && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MIAMI FL
947 AM EDT SAT APR 26 2014 .UPDATE... THE CURRENT FORECAST IS ON TRACK. A DRY AND WARM DAY WITH PLENTY OF SUNSHINE IS EXPECTED FOR TODAY. A LARGE AREA OF HIGH PRESSURE IS LOCATED OVER THE GULF OF MEXICO WITH VERY DRY AIR IN PLACE BETWEEN 700 AND 500 MB. LIGHT NORTHERLY WINDS WILL PREVAIL TODAY AND WILL TURN EASTERLY BY SUNDAY MORNING. THIS WILL BRING A LITTLE BIT OF MORE MOISTURE, BUT IT WILL STAY CONFINED TO THE BOUNDARY LAYER. STRONG SUBSIDENCE BELOW 700 MB WILL DELAY ANY SHOWERS THAT MAY FORM OVER LAND UNTIL LATE IN THE DAY. THE MID LEVEL TEMPERATURES ARE STILL RELATIVELY COOL, AROUND -10C, WHICH WILL ALLOW FOR THE FORMATION OF ONE OR TWO LATE AFTERNOON SHOWERS. HOWEVER, IF ANY THING FORMS IT WILL BE VERY SPARSE IN COVERAGE, AND IN THE AREAS WHERE THE EAST COAST AND WEST COAST SEA BREEZES COLLIDE. OVER THE ATLANTIC WATERS WE CAN BEGIN TO OBSERVE THE SET UP OF A CONVERGENCE LINE BETWEEN EASTERLY FLOW SOUTH OF THE PALM BEACH WATERS AND MORE NORTHERLY FLOW TO THE NORTH. THIS COULD TRIGGER A FEW SHOWERS OVER THE PALM BEACH WATERS. COVERAGE WILL BE SPARSE. && .PREV DISCUSSION... /ISSUED 715 AM EDT SAT APR 26 2014/ AVIATION... DEEP LAYER HIGH PRESSURE WILL DOMINATE SOUTH FLORIDA THROUGH THE FORECAST WITH SEA BREEZES DEVELOPING ALONG BOTH COASTS. SOME OF THE HIGH RESOLUTION SHORT TERM MODELS ARE AGAIN SHOWING A FEW SHOWERS ALONG THE SEA BREEZES OVER THE INTERIOR LATE IN THE AFTERNOON. LEFT OUT OF THE FORECAST FOR NOW AS THESE WILL TOO FEW TO CONSIDER AND MORE THAN LIKELY WELL INLAND AWAY FROM ANY TERMINALS. KOB PREV DISCUSSION... /ISSUED 420 AM EDT SAT APR 26 2014/ DISCUSSION... WATER VAPOR AND RUC ANALYSIS THIS MORNING SHOWED A SHORTWAVE TROUGH FROM THE GREAT LAKES SOUTHEAST TO OFF THE EAST COAST OF NORTH CAROLINA. AN UPPER LEVEL RIDGE STRETCHED FROM THE WESTERN GULF OF MEXICO INTO CANADA...AND ANOTHER SHORTWAVE TROUGH WAS PUSHING INTO CENTRAL CALIFORNIA. A NEARLY ZONAL FLOW WAS NOTED OVER SOUTH FLORIDA. AT THE SURFACE...AN AREA OF LOW PRESSURE WAS LOCATED OVER THE WESTERN ATLANTIC JUST SOUTH OF NEW JERSEY...AND A WEAK FRONTAL BOUNDARY WAS DRAPED SOUTH AND WEST ALONG THE SOUTHEAST STATES COASTS AND INTO SOUTHERN GEORGIA AND ALONG THE NORTHERN GULF COAST. WEAK SURFACE HIGH PRESSURE REMAINED ACROSS FLORIDA AND THE KEYS...WITH A LIGHT NORTHERLY LOW LEVEL FLOW OVER SOUTH FLORIDA. FOR TODAY...DRIER AIR WILL MOVE IN FROM THE WEST...WITH PWATS A LITTLE OVER AN INCH. SO DRY AND WARM CONDITIONS ARE EXPECTED. LIGHT WINDS WILL CONTINUE THIS MORNING...WITH SEA BREEZE BOUNDARIES PUSHING INLAND ALONG BOTH COASTS THIS AFTERNOON. TONIGHT...THE UPPER LEVEL RIDGE OVER THE WESTERN GULF IS FORECAST TO PUSH TOWARDS THE EASTERN GULF AS THE SHORTWAVE OVER CALIFORNIA EJECTS EAST INTO THE INTERMOUNTAIN WEST. THE SURFACE RIDGE OF HIGH PRESSURE OVER THE REGION WILL BEGIN TO SHIFT TO THE EAST INTO THE WESTERN ATLANTIC...WITH EASTERLY FLOW DEVELOPING. LIGHT WINDS ARE FORECAST ACROSS THE INTERIOR...AND PATCHY FOG MAY DEVELOP ONCE AGAIN. AREAS OF SMOKE ARE LIKELY NEAR THE WILDFIRE ACROSS EASTERN COLLIER COUNTY. SUNDAY THROUGH TUESDAY...THE SURFACE RIDGE WILL CONTINUE TO PUSH EAST...AND THE EASTERLY FLOW WILL INCREASE. SEA BREEZE BOUNDARIES ARE FORECAST TO INTERACT ACROSS THE INTERIOR NEAR THE LAKE REGION IN THE AFTERNOON. THIS MAY BE ENOUGH TO SPARK A FEW SHOWERS OR STORMS IN THIS REGION ON SUNDAY. ABOVE NORMAL TEMPERATURES WILL CONTINUE WITH HIGHS IN THE MID 80S TO LOWER 90S. AN UPPER LEVEL LOW WILL CUTOFF ACROSS THE INTERMOUNTAIN WEST AND THE CENTRAL PLAINS SUNDAY...AND THEN MEANDER ACROSS THE CENTRAL PLAINS THROUGH EARLY NEXT WEEK. THE UPPER LEVEL RIDGE WILL MOVE OVER SOUTH FLORIDA ON SUNDAY AND THEN REMAIN THROUGH THE MIDDLE OF THE WEEK. MAINLY DRY AND VERY WARM CONDITIONS WILL CONTINUE. A LARGE UPPER TROUGH/LOW WILL ENVELOP ABOUT THE EASTERN TWO- THIRDS OF THE CONUS WEDNESDAY AND THURSDAY. UPPER HEIGHTS WILL BEGIN TO LOWER...BUT SOME RIDGING WILL REMAIN OVER SOUTH FLORIDA. A COLD FRONT IS FORECAST TO PUSH INTO NORTHERN FLORIDA BY WEDNESDAY EVENING. HOWEVER...THE FRONT IS FORECAST TO REMAIN OVER NORTH OR CENTRAL FLORIDA THROUGH FRIDAY. THE FLOW WILL SHIFT TO THE SOUTHEAST. MOISTURE IS FORECAST TO SLOWLY INCREASE THROUGH THE END OF THE WEEK...AND RAIN CHANCES ARE FORECAST TO INCREASE. DEWPOINTS ARE FORECAST TO INCREASE BACK TO AROUND 70 BY TUESDAY...AND REMAIN AROUND 70 THROUGH THE END OF THE PERIOD. SOUTHEAST WINDS ARE FORECAST TO BE 10-15 KNOTS OVER THE ATLANTIC WATERS AS WELL...AND THIS WILL KEEP LOW TEMPERATURES WELL ABOVE NORMAL FOR THE EAST COAST. OVERNIGHT LOWS ARE FORECAST TO BE IN THE MID/UPPER 70S FOR THE EAST COAST METRO AREAS. HIGHS ARE FORECAST TO BE IN THE MID 80S TO LOW 90S THROUGH THE WEEK. AVIATION... HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER THROUGH THE TAF PERIOD. THIS WILL KEEP VFR CONDITIONS IN PLACE. WINDS WILL PICK UP MID DAY AS THE SEA BREEZE DEVELOPS, THEN RETURN TO LIGHT AND VARIABLE IN THE LATE EVENING HOURS. MARINE... A WEAK PRESSURE GRADIENT PREVAILS ACROSS THE REGIONAL WATERS WITH LIGHT AND SOMEWHAT VARIABLE WINDS TODAY WITH MORE EASTERLY FLOW RETURNING ON SUNDAY INTO EARLY NEXT WEEK. IN GENERAL SEAS ARE EXPECTED TO BE 2 FEET OR LESS THROUGH THE WEEKEND WITH JUST A GRADUAL INCREASE IN WINDS AND SEAS EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 87 72 85 72 / 0 0 10 0 FORT LAUDERDALE 87 77 86 75 / 0 0 10 0 MIAMI 88 75 87 74 / 0 0 0 0 NAPLES 86 70 87 70 / 0 0 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...71/JE LONG TERM....71/JE
AREA FORECAST DISCUSSION
NWS MIAMI FL
715 AM EDT SAT APR 26 2014 .AVIATION... DEEP LAYER HIGH PRESSURE WILL DOMINATE SOUTH FLORIDA THROUGH THE FORECAST WITH SEA BREEZES DEVELOPING ALONG BOTH COASTS. SOME OF THE HIGH RESOLUTION SHORT TERM MODELS ARE AGAIN SHOWING A FEW SHOWERS ALONG THE SEA BREEZES OVER THE INTERIOR LATE IN THE AFTERNOON. LEFT OUT OF THE FORECAST FOR NOW AS THESE WILL TOO FEW TO CONSIDER AND MORE THAN LIKELY WELL INLAND AWAY FROM ANY TERMINALS. KOB && .PREV DISCUSSION... /ISSUED 420 AM EDT SAT APR 26 2014/ DISCUSSION... WATER VAPOR AND RUC ANALYSIS THIS MORNING SHOWED A SHORTWAVE TROUGH FROM THE GREAT LAKES SOUTHEAST TO OFF THE EAST COAST OF NORTH CAROLINA. AN UPPER LEVEL RIDGE STRETCHED FROM THE WESTERN GULF OF MEXICO INTO CANADA...AND ANOTHER SHORTWAVE TROUGH WAS PUSHING INTO CENTRAL CALIFORNIA. A NEARLY ZONAL FLOW WAS NOTED OVER SOUTH FLORIDA. AT THE SURFACE...AN AREA OF LOW PRESSURE WAS LOCATED OVER THE WESTERN ATLANTIC JUST SOUTH OF NEW JERSEY...AND A WEAK FRONTAL BOUNDARY WAS DRAPED SOUTH AND WEST ALONG THE SOUTHEAST STATES COASTS AND INTO SOUTHERN GEORGIA AND ALONG THE NORTHERN GULF COAST. WEAK SURFACE HIGH PRESSURE REMAINED ACROSS FLORIDA AND THE KEYS...WITH A LIGHT NORTHERLY LOW LEVEL FLOW OVER SOUTH FLORIDA. FOR TODAY...DRIER AIR WILL MOVE IN FROM THE WEST...WITH PWATS A LITTLE OVER AN INCH. SO DRY AND WARM CONDITIONS ARE EXPECTED. LIGHT WINDS WILL CONTINUE THIS MORNING...WITH SEA BREEZE BOUNDARIES PUSHING INLAND ALONG BOTH COASTS THIS AFTERNOON. TONIGHT...THE UPPER LEVEL RIDGE OVER THE WESTERN GULF IS FORECAST TO PUSH TOWARDS THE EASTERN GULF AS THE SHORTWAVE OVER CALIFORNIA EJECTS EAST INTO THE INTERMOUNTAIN WEST. THE SURFACE RIDGE OF HIGH PRESSURE OVER THE REGION WILL BEGIN TO SHIFT TO THE EAST INTO THE WESTERN ATLANTIC...WITH EASTERLY FLOW DEVELOPING. LIGHT WINDS ARE FORECAST ACROSS THE INTERIOR...AND PATCHY FOG MAY DEVELOP ONCE AGAIN. AREAS OF SMOKE ARE LIKELY NEAR THE WILDFIRE ACROSS EASTERN COLLIER COUNTY. SUNDAY THROUGH TUESDAY...THE SURFACE RIDGE WILL CONTINUE TO PUSH EAST...AND THE EASTERLY FLOW WILL INCREASE. SEA BREEZE BOUNDARIES ARE FORECAST TO INTERACT ACROSS THE INTERIOR NEAR THE LAKE REGION IN THE AFTERNOON. THIS MAY BE ENOUGH TO SPARK A FEW SHOWERS OR STORMS IN THIS REGION ON SUNDAY. ABOVE NORMAL TEMPERATURES WILL CONTINUE WITH HIGHS IN THE MID 80S TO LOWER 90S. AN UPPER LEVEL LOW WILL CUTOFF ACROSS THE INTERMOUNTAIN WEST AND THE CENTRAL PLAINS SUNDAY...AND THEN MEANDER ACROSS THE CENTRAL PLAINS THROUGH EARLY NEXT WEEK. THE UPPER LEVEL RIDGE WILL MOVE OVER SOUTH FLORIDA ON SUNDAY AND THEN REMAIN THROUGH THE MIDDLE OF THE WEEK. MAINLY DRY AND VERY WARM CONDITIONS WILL CONTINUE. A LARGE UPPER TROUGH/LOW WILL ENVELOP ABOUT THE EASTERN TWO- THIRDS OF THE CONUS WEDNESDAY AND THURSDAY. UPPER HEIGHTS WILL BEGIN TO LOWER...BUT SOME RIDGING WILL REMAIN OVER SOUTH FLORIDA. A COLD FRONT IS FORECAST TO PUSH INTO NORTHERN FLORIDA BY WEDNESDAY EVENING. HOWEVER...THE FRONT IS FORECAST TO REMAIN OVER NORTH OR CENTRAL FLORIDA THROUGH FRIDAY. THE FLOW WILL SHIFT TO THE SOUTHEAST. MOISTURE IS FORECAST TO SLOWLY INCREASE THROUGH THE END OF THE WEEK...AND RAIN CHANCES ARE FORECAST TO INCREASE. DEWPOINTS ARE FORECAST TO INCREASE BACK TO AROUND 70 BY TUESDAY...AND REMAIN AROUND 70 THROUGH THE END OF THE PERIOD. SOUTHEAST WINDS ARE FORECAST TO BE 10-15 KNOTS OVER THE ATLANTIC WATERS AS WELL...AND THIS WILL KEEP LOW TEMPERATURES WELL ABOVE NORMAL FOR THE EAST COAST. OVERNIGHT LOWS ARE FORECAST TO BE IN THE MID/UPPER 70S FOR THE EAST COAST METRO AREAS. HIGHS ARE FORECAST TO BE IN THE MID 80S TO LOW 90S THROUGH THE WEEK. AVIATION... HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER THROUGH THE TAF PERIOD. THIS WILL KEEP VFR CONDITIONS IN PLACE. WINDS WILL PICK UP MID DAY AS THE SEA BREEZE DEVELOPS, THEN RETURN TO LIGHT AND VARIABLE IN THE LATE EVENING HOURS. MARINE... A WEAK PRESSURE GRADIENT PREVAILS ACROSS THE REGIONAL WATERS WITH LIGHT AND SOMEWHAT VARIABLE WINDS TODAY WITH MORE EASTERLY FLOW RETURNING ON SUNDAY INTO EARLY NEXT WEEK. IN GENERAL SEAS ARE EXPECTED TO BE 2 FEET OR LESS THROUGH THE WEEKEND WITH JUST A GRADUAL INCREASE IN WINDS AND SEAS EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 87 72 85 72 / 0 0 10 0 FORT LAUDERDALE 87 77 86 75 / 0 0 10 0 MIAMI 88 75 87 74 / 0 0 0 0 NAPLES 86 70 87 70 / 0 0 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MIAMI FL
420 AM EDT SAT APR 26 2014 .DISCUSSION... WATER VAPOR AND RUC ANALYSIS THIS MORNING SHOWED A SHORTWAVE TROUGH FROM THE GREAT LAKES SOUTHEAST TO OFF THE EAST COAST OF NORTH CAROLINA. AN UPPER LEVEL RIDGE STRETCHED FROM THE WESTERN GULF OF MEXICO INTO CANADA...AND ANOTHER SHORTWAVE TROUGH WAS PUSHING INTO CENTRAL CALIFORNIA. A NEARLY ZONAL FLOW WAS NOTED OVER SOUTH FLORIDA. AT THE SURFACE...AN AREA OF LOW PRESSURE WAS LOCATED OVER THE WESTERN ATLANTIC JUST SOUTH OF NEW JERSEY...AND A WEAK FRONTAL BOUNDARY WAS DRAPED SOUTH AND WEST ALONG THE SOUTHEAST STATES COASTS AND INTO SOUTHERN GEORGIA AND ALONG THE NORTHERN GULF COAST. WEAK SURFACE HIGH PRESSURE REMAINED ACROSS FLORIDA AND THE KEYS...WITH A LIGHT NORTHERLY LOW LEVEL FLOW OVER SOUTH FLORIDA. FOR TODAY...DRIER AIR WILL MOVE IN FROM THE WEST...WITH PWATS A LITTLE OVER AN INCH. SO DRY AND WARM CONDITIONS ARE EXPECTED. LIGHT WINDS WILL CONTINUE THIS MORNING...WITH SEA BREEZE BOUNDARIES PUSHING INLAND ALONG BOTH COASTS THIS AFTERNOON. TONIGHT...THE UPPER LEVEL RIDGE OVER THE WESTERN GULF IS FORECAST TO PUSH TOWARDS THE EASTERN GULF AS THE SHORTWAVE OVER CALIFORNIA EJECTS EAST INTO THE INTERMOUNTAIN WEST. THE SURFACE RIDGE OF HIGH PRESSURE OVER THE REGION WILL BEGIN TO SHIFT TO THE EAST INTO THE WESTERN ATLANTIC...WITH EASTERLY FLOW DEVELOPING. LIGHT WINDS ARE FORECAST ACROSS THE INTERIOR...AND PATCHY FOG MAY DEVELOP ONCE AGAIN. AREAS OF SMOKE ARE LIKELY NEAR THE WILDFIRE ACROSS EASTERN COLLIER COUNTY. SUNDAY THROUGH TUESDAY...THE SURFACE RIDGE WILL CONTINUE TO PUSH EAST...AND THE EASTERLY FLOW WILL INCREASE. SEA BREEZE BOUNDARIES ARE FORECAST TO INTERACT ACROSS THE INTERIOR NEAR THE LAKE REGION IN THE AFTERNOON. THIS MAY BE ENOUGH TO SPARK A FEW SHOWERS OR STORMS IN THIS REGION ON SUNDAY. ABOVE NORMAL TEMPERATURES WILL CONTINUE WITH HIGHS IN THE MID 80S TO LOWER 90S. AN UPPER LEVEL LOW WILL CUTOFF ACROSS THE INTERMOUNTAIN WEST AND THE CENTRAL PLAINS SUNDAY...AND THEN MEANDER ACROSS THE CENTRAL PLAINS THROUGH EARLY NEXT WEEK. THE UPPER LEVEL RIDGE WILL MOVE OVER SOUTH FLORIDA ON SUNDAY AND THEN REMAIN THROUGH THE MIDDLE OF THE WEEK. MAINLY DRY AND VERY WARM CONDITIONS WILL CONTINUE. A LARGE UPPER TROUGH/LOW WILL ENVELOP ABOUT THE EASTERN TWO- THIRDS OF THE CONUS WEDNESDAY AND THURSDAY. UPPER HEIGHTS WILL BEGIN TO LOWER...BUT SOME RIDGING WILL REMAIN OVER SOUTH FLORIDA. A COLD FRONT IS FORECAST TO PUSH INTO NORTHERN FLORIDA BY WEDNESDAY EVENING. HOWEVER...THE FRONT IS FORECAST TO REMAIN OVER NORTH OR CENTRAL FLORIDA THROUGH FRIDAY. THE FLOW WILL SHIFT TO THE SOUTHEAST. MOISTURE IS FORECAST TO SLOWLY INCREASE THROUGH THE END OF THE WEEK...AND RAIN CHANCES ARE FORECAST TO INCREASE. DEWPOINTS ARE FORECAST TO INCREASE BACK TO AROUND 70 BY TUESDAY...AND REMAIN AROUND 70 THROUGH THE END OF THE PERIOD. SOUTHEAST WINDS ARE FORECAST TO BE 10-15 KNOTS OVER THE ATLANTIC WATERS AS WELL...AND THIS WILL KEEP LOW TEMPERATURES WELL ABOVE NORMAL FOR THE EAST COAST. OVERNIGHT LOWS ARE FORECAST TO BE IN THE MID/UPPER 70S FOR THE EAST COAST METRO AREAS. HIGHS ARE FORECAST TO BE IN THE MID 80S TO LOW 90S THROUGH THE WEEK. && .AVIATION... HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER THROUGH THE TAF PERIOD. THIS WILL KEEP VFR CONDITIONS IN PLACE. WINDS WILL PICK UP MID DAY AS THE SEA BREEZE DEVELOPS, THEN RETURN TO LIGHT AND VARIABLE IN THE LATE EVENING HOURS. && .MARINE... A WEAK PRESSURE GRADIENT PREVAILS ACROSS THE REGIONAL WATERS WITH LIGHT AND SOMEWHAT VARIABLE WINDS TODAY WITH MORE EASTERLY FLOW RETURNING ON SUNDAY INTO EARLY NEXT WEEK. IN GENERAL SEAS ARE EXPECTED TO BE 2 FEET OR LESS THROUGH THE WEEKEND WITH JUST A GRADUAL INCREASE IN WINDS AND SEAS EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 87 72 85 72 / 0 0 10 0 FORT LAUDERDALE 87 77 86 75 / 0 0 10 0 MIAMI 88 75 87 74 / 0 0 0 0 NAPLES 86 70 87 70 / 0 0 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE...84/AK AVIATION...13/SI
AREA FORECAST DISCUSSION...CORRECTED
NWS BOISE ID
858 PM MDT SUN APR 27 2014 .DISCUSSION...MINOR UPDATE TO INCLUDE ISOLATED THUNDERSTORMS FROM THE TREASURE AND MAGIC VALLEYS SOUTH TO THE NV BORDER UNTIL MIDNIGHT. SEVERAL STRIKES OCCURRED NW OF ADRIAN OREGON FROM 815 TO 830 PM WITH CELLS NEAR THE BASE OF A NEGATIVE TILT UPPER LEVEL TROUGH. LATEST HRRR RUNS DEVELOP THE AREA OF STRONGER RADAR RETURNS WEST OF BOISE THROUGH THE TREASURE VALLEY THEN SOUTHEAST THROUGH MIDNIGHT. WITH WEST FLOW ALOFT AND RADAR TRENDS THIS LOOKS REASONABLE. LATE NIGHT CLEARING WITH PATCHY FREEZING TEMPERATURES IN THE AG VALLEYS IS STILL ON TRACK FOR LATE TONIGHT AND EARLY MONDAY...WITH COLD LOWS PERSISTING MONDAY MORNING AS WELL. && .AVIATION...ISOLATED TO SCATTERED MVFR/LOCAL IFR SNOW SHOWERS WILL CONTINUE OVER THE MOUNTAINS THROUGH MONDAY. SNOW LEVELS MAINLY ABOVE 4K FT MSL. ISOLATED THUNDERSTORMS MAINLY IN THE SNAKE RIVER VALLEY AND SOUTHWEST HIGHLANDS WILL END BY 06Z. OTHERWISE EXPECT VFR CONDITIONS. SURFACE WINDS...LIGHT EXCEPT INCREASING TO 15-25 KTS E AND S OF KMUO AFTER 15Z. WINDS ALOFT... NORTHWEST UP TO 30 KTS AT 10K FT MSL. && .PREV DISCUSSION... SHORT TERM...TONIGHT THROUGH TUESDAY...UPPER LEVEL WAVE WITH ASSOCIATED SURFACE COLD FRONT IS MOVING THROUGH THE REGION AT THIS TIME. SHOWERS AND THUNDERSTORMS ARE SPREAD OVER THE CWA AND ARE MOVING EAST TO SOUTHEAST AT ABOUT 40 MPH. THIS CONVECTION WILL CONTINUE THROUGH THE AFTERNOON AND THEN DECREASE INTO THE EARLY EVENING HOURS AS IT MOVES EAST. SO FAR SMALL HAIL...OR MORE PROPERLY GRAUPEL...HAS BEEN REPORTED WITH SOME OF THE STRONGER CELLS. TONIGHT...SKIES WILL BEGIN TO CLEAR FROM THE WEST AND TEMPS WILL DROP DOWN AROUND 10 DEGREES BELOW NORMAL. SHOWERS WILL LINGER IN THE WEST-CENTRAL MOUNTAINS TOMORROW...BUT BY TOMORROW EVENING THE CHANCE OF PRECIP WILL DROP TO NEAR ZERO. A WARM UP WILL BEGIN TOMORROW AS DRY CONDITIONS TAKE HOLD UNDER A BUILDING UPPER LEVEL RIDGE. HOWEVER...WE WILL STILL BE 5 TO 10 DEGREES BELOW NORMAL. THE WARM UP REALLY KICKS IN TUESDAY...WITH HIGHS BACK UP TO NEAR OR JUST A FEW DEGREES ABOVE NORMAL. LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...UPPER LEVEL RIDGE WILL BUILD OVER THE WEST COAST THROUGH FRIDAY BRINGING WARMER AND DRIER CONDITIONS. THE RIDGE AXIS REMAINS OVER THE CASCADE MOUNTAINS REACHING IT/S PEAK AMPLITUDE ON THURSDAY. THE WARMEST AIR NEVER QUITE GETS INTO THE REGION BUT TEMPERATURES WILL BE ABOUT 10 DEGREES ABOVE NORMAL THURSDAY. UPPER RIDGE WEAKENS SIGNIFICANTLY FRIDAY AS SHORTWAVES ASSOCIATED WITH STRENGTHENING UPPER LEVEL LOW OVER THE HUDSON BAY PUSH SOUTHWARD FROM BRITISH COLUMBIA. BY SATURDAY THE RIDGE FLATTENS WITH THE UPPER FLOW BECOMING NORTHWEST FOR A SLIGHT CHANCE OF PRECIPITATION IN THE WEST CENTRAL MOUNTAINS THROUGH SUNDAY. TEMPERATURES FALL CLOSE TO NORMAL ON SUNDAY. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...NONE. OR...NONE. && $$ WEATHER.GOV/BOISE DISCUSSION...VM AVIATION.....JT PREV SHORT TERM...SP PREV LONG TERM....JS/WH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
930 PM CDT SUN APR 27 2014 .DISCUSSION... 304 PM CDT RELATIVELY QUIET DAY ACROSS NORTHERN IL/NORTHWEST IN...WITH VISIBLE IMAGERY INDICATING JUST SOME HIGH BASED CLOUDS. UNFORTUNATELY WITH A STRONG SFC RIDGE PARKED NORTHEAST OVER HUDSON BAY...AND A STRENGTHENING LOW PRESSURE OVER THE CENTRAL PLAINS...THIS HAS SETUP A TIGHT GRADIENT OVER THE NORTHERN HALF OF THE CWFA AND A STIFF EAST WIND. AS A RESULT AREAS ADJACENT TO THE LAKESHORE IN ILLINOIS HAVE NOT HAD TEMPS WARM BEYOND THE MID/UPR 40S. ELSEWHERE TEMPS HAVE BEEN ABLE TO WARM WELL INTO THE 50S AND LOW 60S. SFC ANALYSIS INDICATED ONE BOUNDARY BEGINNING TO LIFT NORTH INTO THE SOUTHERN CWFA...WHERE TEMPS HAVE BEEN ABLE TO QUICKLY WARM INTO THE MID/UPR 70S WHILE DEW POINTS WERE STILL HOLDING IN THE LOW/MID 40S. THIS WAS THE LEADING EDGE OF COOLING CLOUD TOPS...AND A FEW ISOLATED SHRA/TSRA. THE MOIST BOUNDARY REMAINED FURTHER SOUTH AND APPEARS TO BE MORE SLUGGISH AT LIFTING NORTH UNTIL LATER THIS EVENING. THE MAIN CONVECTIVE FEATURES HAVE MAINLY BEEN POSITIONED OVER WESTERN IOWA STRETCHING SOUTH THROUGH MISSOURI...WHICH IS THE LOCATION OF THE STRONGER CONVERGENCE AND BEST INSTABILITY. GUIDANCE FOR THIS EVENING HAS BEEN RELATIVELY CONSISTENT...WITH HOLDING PRECIP/CONVECTION OUT OF THE BULK OF THE CWFA OR MAINLY WEST OF A ROCKFORD TO KANKAKEE LINE UNTIL AFT 00Z. MID-LVL INSTABILITY DOES CREEP UP AND WITH THE WEAK BOUNDARY CURRENTLY LIFTING NORTH...THE POSSIBILITY OF AN ISOLATED SHRA/TSRA PRIOR TO 00Z IN THE WESTERN CWFA DOES LOOK POSSIBLE. PWAT VALUES WILL STEADILY INCREASE THIS EVENING...NEARING 1.5" AND A FEW GUIDANCE MEMBERS SUGGEST A FEW LOCATIONS NEARING 1.8" SHORTLY AFT MIDNIGHT. IT DOES APPEAR THAT THE BOUNDARY STALLS FROM LIFTING FURTHER NORTH THAN THE I-88 CORRIDOR OVER NORTHERN IL. LLVL NOCTURNAL JET CRANKS UP OVERNIGHT WITH 850MB SOUTHERLY WINDS NEARING 50KTS. IT APPEARS THE MOST PROBABLE TIMING FOR CONVECTION OVERSPREADING THE CWFA WILL BE AFT 03Z. WITH THE AFOREMENTIONED CONDITIONS...IT APPEARS THE GREATEST CONCERN OVERNIGHT WILL BE THE POTENTIAL FOR THUNDERSTORMS PRODUCING PERIODS OF HEAVY RAINFALL. THIS MATCHES UP WELL WITH THE THINKING OUT OF THE STORM PREDICTION CENTER...WHICH HAS THE SLIGHT RISK OUTLINED JUST SOUTH/SOUTHWEST OF THE FORECAST AREA TONIGHT. OVERNIGHT LOWS WILL BE A CHALLENGE. AT THIS TIME HAVE OPTED TO HOLD ONTO THE EXPECTED COOLING OVERNIGHT...ALTHOUGH COULD SEE TEMPS ACTUALLY HOLDING MUCH WARMER IN THE SOUTHERN CWFA. IT WILL HINGE ON THE ARRIVAL OF THE BOUNDARIES LIFTING NORTH. MONDAY THROUGH MONDAY NIGHT... ONGOING CONVECTION DURING THE PRE-DAWN HOURS SHOULD BE SLOWLY LIFTING NORTH ACROSS THE FORECAST AREA...WITH A POSSIBLE LULL IN ACTIVITY CLOSER TO 16-20Z. THEN THE QUESTION REMAINS WHEN WILL THE ATMOSPHERE RECOVER. CURRENT INDICATIONS ARE THAT THE ATMOSPHERE WILL BE ABLE TO RECOVER BY 20Z...WHICH BECOMES A BIT OF A CONCERN FOR STRONG TO POSSIBLY SEVERE STORMS TO DEVELOP. THE SFC LOW WILL BE SLOWLY SLIDING EAST...WITH THE 500MB VORT MAXIMA WILL BE ROUNDING THE TROUGH AXIS AND PLACE THE CWFA NEAR THE LEFT-EXIT REGION. WITH HEIGHTS EXPECTED TO BE LOWERING...AND VERY WARM/MOIST AIR OVERHEAD AND GOOD CONVERGENCE...EXPECT THINGS TO BLOSSOM RATHER QUICKLY BY THE AFTN MON. WITH STRONG LIFT THROUGH THIS REGION...LARGE HAIL DOES LOOK POSSIBLE FROM SOME OF THE STRONGER/SEVERE STORMS. WITH A LINGERING BOUNDARY OVER THE CWFA...FOCUSED HELICITY MAY ALLOW A FEW STRONGER STORMS TO PRODUCE AN ISOLATED TORNADO. BASED ON THESE CONDITIONS THE SPC HAS OUR CWFA SOUTH OF I-88 OUTLOOKED FOR A SLIGHT RISK OF SEVERE WEATHER MON. A DRY WEDGE DOES TRY TO WORK INTO THE REGION LATE MON NGT...WHICH COULD ALLOW FOR SLIGHTLY LOWER POPS. STILL HAVE LIKELY CONDS THRU MONDAY NIGHT. TEMPS MON SOUTH OF THE BOUNDARY COULD WARM WELL INTO THE 70S AND POSSIBLY SEVERAL AREAS SOUTH OF LASALLE TO KANKAKEE REACHING THE LOW 80S. FURTHER NORTH CLOSER TO THE BOUNDARY TEMPS WILL BE MUCH COOLER IN THE LOW/MID 50S. NORTHEAST IL AREAS ADJACENT TO LAKE MICHIGAN WILL SEE TEMPS HOLD IN THE MID/UPR 40S WITH A STRONG EAST FLOW OFF OF LAKE MICHIGAN. TUESDAY THROUGH THURSDAY... ONCE THE SFC LOW WRAPS UP OVER THE REGION...IT BUMPS UP AGAINST A ROBUST SFC RIDGE PARKED OVER HUDSON BAY. THIS WILL PREVENT THE LOW FROM DEPARTING THE REGION...AND MAINTAIN PERIODS OF PRECIP THROUGH TUE/WED/THUR. FORTUNATELY THE CONVECTIVE POTENTIAL COMES TO AN END TUE NGT. TEMPS WILL STEADILY COOL WITH THE WARMEST DAY IN THIS STRETCH BEING TUE WHEN HIGHS SHUD BE ABLE TO REACH THE 60S. THEN WED/THUR WITH CONSIDERABLE SOLAR SHIELDING...TEMPS WILL STRUGGLE TO WARM BEYOND THE 50S. FRIDAY THROUGH SUNDAY... TOWARDS THE END OF THE SFC RIDGE OVER HUDSON BAY BEGINS TO SLIDE EAST AND WEAKEN...WHICH WILL ALLOW THE QUASI-STATIONARY LOW TO FINALLY DEPART THE REGION. THIS MAY BRING SOME DRY AIR TO THE REGION BY SAT NGT. UNFORTUNATELY GUIDANCE IS THEN SUGGESTING A TROUGH TO DEVELOP ACROSS THE CENTRAL PLAINS AND SLIDE SOUTHEAST TOWARDS THE PLAINS AND WESTERN GREAT LAKES BY THE SECOND HALF OF THE WEEKEND. BEACHLER && .HYDROLOGY... A MOISTURE-RICH ATMOSPHERE...ESPECIALLY FOR LATE APRIL...WILL PRESENT HEAVY RAIN LIKELIHOOD TONIGHT AND POSSIBLY EXTENDING INTO MONDAY MORNING. RAIN COVERAGE SHOULD BE HIGHEST BY LATE EVENING INTO OVERNIGHT...WITH EMBEDDED STORMS PRESENTING THE HIGHEST LIKELIHOOD FOR THESE PERIODS HEAVY RAIN. OUR FORECAST CALLS FOR ONE TO TWO INCHES OF RAIN IN MOST AREAS TONIGHT INTO MONDAY MORNING. WHILE THIS IS EXPECTED TO BE MORE OF A RAIN SITUATION THAN SCATTERED SHOWERS...WHEN DEALING WITH EMBEDDED STORMS...RAINFALL AMOUNTS ARE LIKELY TO VARY QUITE A BIT AND HEAVIER MAGNITUDE COULD OCCUR UNDER MORE PERSISTENT AREAS OF STORMS. SOMEWHAT DRY ANTECEDENT CONDITIONS PRECLUDE ANY TYPE OF FLASH FLOOD WATCH ISSUANCE. FLASH FLOOD GUIDANCE FROM THE RIVER FORECAST CENTER CALLS FOR TWO INCHES OR MORE PER SIX HOURS NEEDED IN MOST LOCATIONS TO WARRANT A HEIGHTENED THREAT. WILL STILL NEED TO MONITOR CLOSELY...ESPECIALLY CONSIDERING MONDAY AFTERNOON AND EVENING ARE LIKELY TO PRESENT STORMS...SOME OF WHICH WILL AGAIN BE CAPABLE OF HEAVY RAIN. THE COMBINED EFFECTS THROUGH THE NEXT 48 HOURS COULD CAUSE SOME RIVERS TO RISE TO NEAR FLOOD STAGE BASED ON PREDICTIONS USING A SUITE OF COMPUTER MODELS. MTF && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * ADDITIONAL ROUNDS OF SHRA AND PROBABLY EMBEDDED TSRA OVERNIGHT AND MONDAY MORNING. TRIED TO TIME THE MOST LIKELY WINDOWS IN THE TAF BUT TIMING MAY WELL CHANGE. * STEADY EASTERLY WINDS GUSTING TO AROUND 25 KT AT TIMES TONIGHT/MONDAY...30 KT GUSTS POSSIBLE. * CIGS LOWERING TO MVFR THEN IFR TONIGHT/MONDAY MORNING...MAY NEED TO SLOW ARRIVAL TIMING. * ORGANIZED SHRA/TSRA POSSIBLE LATE AFTERNOON/EARLY EVENING MONDAY. MDB //DISCUSSION...UPDATED 03Z... RAIN BEGINNING TO WIND DOWN FOR A BIT ACROSS THE TERMINALS. EASTERLY WINDS ARE STARTING TO SPORADICALLY GUST TO AROUND 25 KT AND AM THINKING GUSTS WILL BECOME MORE FREQUENT INTO THE OVERNIGHT...WITH SUSTAINED SPEEDS IN THE 15 TO 20 KT RANGE. RADAR MOSAIC SHOWS THE NEXT BAND OF SHOWERS AND SOME EMBEDDED THUNDER WORKING NORTHEAST ACROSS WEST CENTRAL AND SOUTHWEST ILLINOIS. THIS LOOKS TO ARRIVE IN THE 07-09Z TIME FRAME SO HAVE ADJUSTED TIMING TO BETTER FIT THIS THINKING. KEPT VCTS MENTION BUT BASED ON LATEST TRENDS THIS MAY BE A BIT OVERDONE. EVOLUTION OF RAIN/THUNDER THROUGH MID MORNING IS STILL UP FOR DEBATE SO WILL MAKE LITTLE CHANGE TO EARLIER THINKING. DID FURTHER SLOW THE LOWERING OF CIGS TO IFR. MDB FROM 00Z... THUNDERSTORM FORECAST REMAINS A CHALLENGE THIS EVENING. THUNDER THAT POPPED NEAR THE CHI TERMINALS LAST 1-2 HOURS HAS FADED FOR THE MOST PART WITH JUST ABOUT ALL LIGHT RAIN UPSTREAM TO THE SOUTH. MORE ORGANIZED CONVECTION ACROSS NORTHWEST IL IS TRACKING NORTHEAST AND FADING BUT DO EXPECT SOME THUNDER TO CROSS THE RFD AREA AND POINTS NORTHWEST OF ORD PRIOR TO 02 OR 03Z. OTHERWISE SHRA WILL PERSIST THROUGH THE EVENING. SHRA/TSRA OVER CENTRAL MISSOURI APPEARS TO BE THE NEXT ORGANIZED ACTIVITY TO AFFECT THE AREA EARLY TONIGHT. THERE THEN APPEARS TO BE A GAP IN COVERAGE TO SOME DEGREE LATER TONIGHT BEFORE ANOTHER ROUND OF SHRA/TSRA AFFECTS THE AREA MONDAY MORNING IN CONJUNCTION WITH AN UPPER TROUGH MOVING FROM NW ARKANSAS. CIGS WILL LIKELY LOWER WITH TIME TONIGHT BUT HAVE SLOWED THE ARRIVAL OF IFR BY SEVERAL HOURS AND MAY STILL BE TOO FAST WITH THE LOWERING OVERALL. WINDS HAVE ABATED FOR NOW BUT SHOULD COME BACK UP AND REMAIN STEADY FROM THE EAST. SHOULD SPEEDS NOT COME UP AS MUCH AS EXPECTED THEN LOW LEVEL WIND SHEAR MAY BECOME DEVELOP AS SPEEDS INCREASE TO AROUND 50 KT BY 2000 FT AGL. THERE MAY BE A BREAK IN OVERALL ACTIVITY FOR A TIME FROM MIDDAY THROUGH EARLY OR MID AFTERNOON MONDAY BUT A WARM FRONT WILL BE STRENGTHENING SOUTH OF THE TERMINALS THROUGH THE DAY AND GRADUALLY LIFTING NORTHWARD. THIS IS EXPECTED TO TRIGGER SHRA/TSRA BY MID OR LATE AFTERNOON THAT WILL LIFT NORTH INTO THE EVENING. HAVE FAIRLY GOOD CONFIDENCE IN THIS SCENARIO SO HAVE ADDED A SEVERAL HOUR WINDOW OF TSRA TO THE TAFS LATER MONDAY AFTERNOON. TIMING MAY NEED TO BE SHIFTED HOWEVER. OVERALL THERE IS A RISK FOR SHRA/TSRA AT JUST ABOUT ANY TIME THROUGH TOMORROW EVENING BUT TRIED TO IDENTIFY THE MOST LIKELY PERIODS IN THE TAF. MDB //ORD AND MDW CONFIDENCE...UPDATED 03Z... * MEDIUM CONFIDENCE IN ADDITIONAL BANDS OF SHRA AND EMBEDDED TSRA AFFECTING THE TERMINALS OVERNIGHT/MONDAY MORNING. * MEDIUM-HIGH CONFIDENCE IN WIND TRENDS. * MEDIUM-HIGH CONFIDENCE IN CIGS LOWERING LATER TONIGHT...LOW- MEDIUM CONFIDENCE IN TIMING. * MEDIUM-HIGH CONFIDENCE IN SHRA/TSRA OCCURRING LATER MONDAY...MEDIUM CONFIDENCE IN TIMING. MDB //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY...CHANCE RAIN AND THUNDER...MVFR LIKELY WITH IFR POSSIBLE. WEDNESDAY - SATURDAY...CHANCE RAIN...MVFR LIKELY WITH IFR POSSIBLE. MDB && .MARINE... 243 PM CDT THE PRIMARY FEATURE THAT WILL BE DOMINATING CONDITIONS OVER THE LAKE FOR THE NEXT FEW DAYS WILL BE A LARGE LOW PRESSURE SYSTEM MOVING THROUGH THE PLAINS AND HEADING SLOWLY TOWARD THE WESTERN GREAT LAKES. THE WARM FRONT EXTENDING EAST FROM THIS LOW IS STAYING SOUTH OF THE LAKE SO FAR...BUT IS SUPPORTING A TIGHT PRESSURE GRADIENT AND STRONG EASTERLY WINDS OVER THE LAKE. MEASURED GUSTS AT LAND BASED POINTS AROUND THE LAKE THIS AFTERNOON ARE IN THE NEIGHBORHOOD OF 25 KTS BUT WILL BE INCREASING THROUGH THE EVENING...EVENTUALLY TO GALES. THIS FITS WITH THE WIND OBSERVATIONS IN THE UPPER TEENS WE ARE SEEING SO FAR FROM SHIPS ON THE LAKE...THOUGH THERE ARE MANY MORE SHIPS OUT THERE THAN SHIP OBSERVATIONS TODAY...SO SOME VESSELS MAY BE SEEING DIFFERENT VALUES. THE WARM FRONT FINALLY REACHES THE SOUTHERN LAKE MONDAY NIGHT. THIS WILL RELAX THE GRADIENT SOMEWHAT...ESPECIALLY ACROSS THE SOUTH HALF...SO THIS IS WHEN WE HAVE THE GALE WARNING CURRENTLY SET TO EXPIRE. THERE IS A CHANCE THAT THE WARNING OVER THE NORTH HALF MAY NEED TO BE EXTENDED INTO THE DAYTIME HOURS TUESDAY. LENNING && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM SUNDAY. GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741- LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872- LMZ874-LMZ876-LMZ878 UNTIL 10 PM MONDAY. GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567- LMZ868...3 AM MONDAY TO 10 PM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion National Weather Service Lincoln IL 859 PM CDT Sun Apr 27 2014 .DISCUSSION... ISSUED 859 PM CDT Sun Apr 27 2014 First round of convection has lifted into northern Illinois and diminished early this evening, while a second round is currently developing upstream across Missouri. Mesoscale analysis shows a relatively stable airmass in place across central Illinois into eastern Missouri, with highest MUCAPE values focused further south across the Ozarks. As a result, numerous thunderstorms are merging into an MCS across southeast Missouri into northern Arkansas, while only scattered weaker activity is noted further north into central/northern Missouri. It appears the severe MCS will track E/NE across far southern Illinois and western Kentucky over the next few hours. Meanwhile, a relative lull in the precip will be noted across central Illinois. 50kt LLJ developing from the lower Mississippi River Valley northward into Illinois is expected to create increasing showers/thunder as the night progresses. Have made some adjustments to POPs for the rest of the night, mainly to lower rain chances this evening, but will still go with categorical overnight. Barnes && .AVIATION... ISSUED 645 PM CDT Sun Apr 27 2014 Scattered showers and thunderstorms will affect the central IL airports this evening, especially the I-74 taf sites with MVFR vsbys and ceilings possible. Visibility dropped below 2 miles at CMI with heavy rain but this will be brief. HRRR shows a widespread band of showers and thunderstorms lifting ne across central IL and brought in MVFR ceilings and visibilities again. Could be lull in convection Monday morning with more redevelopment in unstable air mass during Monday afternoon with MVFR conditions returning. ENE winds have diminish for a time early this morning to 10-15 kts and gusts 15-25 kts to veer se and increase to 15-20 kts with gusts to around 25 kts overnight and then turn SSE on Monday. Strong low pressure of 984 mb over north central KS to lift ne to NE/IA border by Monday afternoon while lifting warm front from sw IL through central IL during overnight and into northern IL Monday. 07 && .PREV DISCUSSION... ISSUED 302 PM CDT Sun Apr 27 2014 Models in good agreement with the overall pattern and surface features. Differences are in the small mesoscale features and environmental changes due to the storms moving through the area currently. Concerns this package will be storm system moving into the area late this afternoon and through this evening. Then another round of severe weather is possible tomorrow afternoon through tomorrow evening. Models continue to look similar with mid and long range models showing the upper level low sitting over the area and spinning for rest of the week. This means unsettled weather for the middle and latter part of the work week. SHORT TERM...Tonight through Wednesday Line of strong to severe storms is moving across northern MO and will reach into western IL in a couple of hours. SPC has issued a severe watch til 9pm to cover this line of storms. Large hail and damaging winds look to be the primary threat, though an isolated tornado is not out of the question. Occasional thunderstorms will continue late this afternoon and into tonight. Once the line of storms moves through, there will likely be a break in the pcpn over some of the area. However, with the warm front becoming active, pcpn could continue on and off through the night. So will continue high pops over the area. CWA will be well entrenched in the warm sector tomorrow and the break in the pcpn will likely continue during the early morning hours. However, things will become active during the late morning hours again as the dry line moves toward the area. Severe weather is again likely from late morning through the afternoon with the dry line. Will be plenty of instability and sufficient shear for some storm to rotate. Plus, the cutoff 500mb low is a cold core. So, good lapse rates to support hail. SVR threat looks to be hail and wind, along with tornadoes closer to the lower pressure area that will be northwest of the cwa during the afternoon. Thunderstorms will be possible again Tuesday as the low pressure area pulls east and northeast of the area. Then Tue night and Wed, with the upper level low still rotating around northern IL, diurnal showers will remain possible through mid week. Temps will remain warm, but then cool off on Wed after the upper level system gets closer to the area with cooler air. LONG TERM...Wednesday night through Sunday The upper level system will remain near the area through the rest of the week. This will continue to bring diurnal showers to the region through Saturday. Then am expecting a change in the pattern for the rest of the weekend, though another system is forecast to bring pcpn on Sunday. Temps will remain on the cool side through the period as upper level troughiness continues through the rest of the week and into the weekend. A more zonal flow looks possible by end of the weekend. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
719 PM CDT SUN APR 27 2014 .DISCUSSION... 304 PM CDT RELATIVELY QUIET DAY ACROSS NORTHERN IL/NORTHWEST IN...WITH VISIBLE IMAGERY INDICATING JUST SOME HIGH BASED CLOUDS. UNFORTUNATELY WITH A STRONG SFC RIDGE PARKED NORTHEAST OVER HUDSON BAY...AND A STRENGTHENING LOW PRESSURE OVER THE CENTRAL PLAINS...THIS HAS SETUP A TIGHT GRADIENT OVER THE NORTHERN HALF OF THE CWFA AND A STIFF EAST WIND. AS A RESULT AREAS ADJACENT TO THE LAKESHORE IN ILLINOIS HAVE NOT HAD TEMPS WARM BEYOND THE MID/UPR 40S. ELSEWHERE TEMPS HAVE BEEN ABLE TO WARM WELL INTO THE 50S AND LOW 60S. SFC ANALYSIS INDICATED ONE BOUNDARY BEGINNING TO LIFT NORTH INTO THE SOUTHERN CWFA...WHERE TEMPS HAVE BEEN ABLE TO QUICKLY WARM INTO THE MID/UPR 70S WHILE DEW POINTS WERE STILL HOLDING IN THE LOW/MID 40S. THIS WAS THE LEADING EDGE OF COOLING CLOUD TOPS...AND A FEW ISOLATED SHRA/TSRA. THE MOIST BOUNDARY REMAINED FURTHER SOUTH AND APPEARS TO BE MORE SLUGGISH AT LIFTING NORTH UNTIL LATER THIS EVENING. THE MAIN CONVECTIVE FEATURES HAVE MAINLY BEEN POSITIONED OVER WESTERN IOWA STRETCHING SOUTH THROUGH MISSOURI...WHICH IS THE LOCATION OF THE STRONGER CONVERGENCE AND BEST INSTABILITY. GUIDANCE FOR THIS EVENING HAS BEEN RELATIVELY CONSISTENT...WITH HOLDING PRECIP/CONVECTION OUT OF THE BULK OF THE CWFA OR MAINLY WEST OF A ROCKFORD TO KANKAKEE LINE UNTIL AFT 00Z. MID-LVL INSTABILITY DOES CREEP UP AND WITH THE WEAK BOUNDARY CURRENTLY LIFTING NORTH...THE POSSIBILITY OF AN ISOLATED SHRA/TSRA PRIOR TO 00Z IN THE WESTERN CWFA DOES LOOK POSSIBLE. PWAT VALUES WILL STEADILY INCREASE THIS EVENING...NEARING 1.5" AND A FEW GUIDANCE MEMBERS SUGGEST A FEW LOCATIONS NEARING 1.8" SHORTLY AFT MIDNIGHT. IT DOES APPEAR THAT THE BOUNDARY STALLS FROM LIFTING FURTHER NORTH THAN THE I-88 CORRIDOR OVER NORTHERN IL. LLVL NOCTURNAL JET CRANKS UP OVERNIGHT WITH 850MB SOUTHERLY WINDS NEARING 50KTS. IT APPEARS THE MOST PROBABLE TIMING FOR CONVECTION OVERSPREADING THE CWFA WILL BE AFT 03Z. WITH THE AFOREMENTIONED CONDITIONS...IT APPEARS THE GREATEST CONCERN OVERNIGHT WILL BE THE POTENTIAL FOR THUNDERSTORMS PRODUCING PERIODS OF HEAVY RAINFALL. THIS MATCHES UP WELL WITH THE THINKING OUT OF THE STORM PREDICTION CENTER...WHICH HAS THE SLIGHT RISK OUTLINED JUST SOUTH/SOUTHWEST OF THE FORECAST AREA TONIGHT. OVERNIGHT LOWS WILL BE A CHALLENGE. AT THIS TIME HAVE OPTED TO HOLD ONTO THE EXPECTED COOLING OVERNIGHT...ALTHOUGH COULD SEE TEMPS ACTUALLY HOLDING MUCH WARMER IN THE SOUTHERN CWFA. IT WILL HINGE ON THE ARRIVAL OF THE BOUNDARIES LIFTING NORTH. MONDAY THROUGH MONDAY NIGHT... ONGOING CONVECTION DURING THE PRE-DAWN HOURS SHOULD BE SLOWLY LIFTING NORTH ACROSS THE FORECAST AREA...WITH A POSSIBLE LULL IN ACTIVITY CLOSER TO 16-20Z. THEN THE QUESTION REMAINS WHEN WILL THE ATMOSPHERE RECOVER. CURRENT INDICATIONS ARE THAT THE ATMOSPHERE WILL BE ABLE TO RECOVER BY 20Z...WHICH BECOMES A BIT OF A CONCERN FOR STRONG TO POSSIBLY SEVERE STORMS TO DEVELOP. THE SFC LOW WILL BE SLOWLY SLIDING EAST...WITH THE 500MB VORT MAXIMA WILL BE ROUNDING THE TROUGH AXIS AND PLACE THE CWFA NEAR THE LEFT-EXIT REGION. WITH HEIGHTS EXPECTED TO BE LOWERING...AND VERY WARM/MOIST AIR OVERHEAD AND GOOD CONVERGENCE...EXPECT THINGS TO BLOSSOM RATHER QUICKLY BY THE AFTN MON. WITH STRONG LIFT THROUGH THIS REGION...LARGE HAIL DOES LOOK POSSIBLE FROM SOME OF THE STRONGER/SEVERE STORMS. WITH A LINGERING BOUNDARY OVER THE CWFA...FOCUSED HELICITY MAY ALLOW A FEW STRONGER STORMS TO PRODUCE AN ISOLATED TORNADO. BASED ON THESE CONDITIONS THE SPC HAS OUR CWFA SOUTH OF I-88 OUTLOOKED FOR A SLIGHT RISK OF SEVERE WEATHER MON. A DRY WEDGE DOES TRY TO WORK INTO THE REGION LATE MON NGT...WHICH COULD ALLOW FOR SLIGHTLY LOWER POPS. STILL HAVE LIKELY CONDS THRU MONDAY NIGHT. TEMPS MON SOUTH OF THE BOUNDARY COULD WARM WELL INTO THE 70S AND POSSIBLY SEVERAL AREAS SOUTH OF LASALLE TO KANKAKEE REACHING THE LOW 80S. FURTHER NORTH CLOSER TO THE BOUNDARY TEMPS WILL BE MUCH COOLER IN THE LOW/MID 50S. NORTHEAST IL AREAS ADJACENT TO LAKE MICHIGAN WILL SEE TEMPS HOLD IN THE MID/UPR 40S WITH A STRONG EAST FLOW OFF OF LAKE MICHIGAN. TUESDAY THROUGH THURSDAY... ONCE THE SFC LOW WRAPS UP OVER THE REGION...IT BUMPS UP AGAINST A ROBUST SFC RIDGE PARKED OVER HUDSON BAY. THIS WILL PREVENT THE LOW FROM DEPARTING THE REGION...AND MAINTAIN PERIODS OF PRECIP THROUGH TUE/WED/THUR. FORTUNATELY THE CONVECTIVE POTENTIAL COMES TO AN END TUE NGT. TEMPS WILL STEADILY COOL WITH THE WARMEST DAY IN THIS STRETCH BEING TUE WHEN HIGHS SHUD BE ABLE TO REACH THE 60S. THEN WED/THUR WITH CONSIDERABLE SOLAR SHIELDING...TEMPS WILL STRUGGLE TO WARM BEYOND THE 50S. FRIDAY THROUGH SUNDAY... TOWARDS THE END OF THE SFC RIDGE OVER HUDSON BAY BEGINS TO SLIDE EAST AND WEAKEN...WHICH WILL ALLOW THE QUASI-STATIONARY LOW TO FINALLY DEPART THE REGION. THIS MAY BRING SOME DRY AIR TO THE REGION BY SAT NGT. UNFORTUNATELY GUIDANCE IS THEN SUGGESTING A TROUGH TO DEVELOP ACROSS THE CENTRAL PLAINS AND SLIDE SOUTHEAST TOWARDS THE PLAINS AND WESTERN GREAT LAKES BY THE SECOND HALF OF THE WEEKEND. BEACHLER && .HYDROLOGY... A MOISTURE-RICH ATMOSPHERE...ESPECIALLY FOR LATE APRIL...WILL PRESENT HEAVY RAIN LIKELIHOOD TONIGHT AND POSSIBLY EXTENDING INTO MONDAY MORNING. RAIN COVERAGE SHOULD BE HIGHEST BY LATE EVENING INTO OVERNIGHT...WITH EMBEDDED STORMS PRESENTING THE HIGHEST LIKELIHOOD FOR THESE PERIODS HEAVY RAIN. OUR FORECAST CALLS FOR ONE TO TWO INCHES OF RAIN IN MOST AREAS TONIGHT INTO MONDAY MORNING. WHILE THIS IS EXPECTED TO BE MORE OF A RAIN SITUATION THAN SCATTERED SHOWERS...WHEN DEALING WITH EMBEDDED STORMS...RAINFALL AMOUNTS ARE LIKELY TO VARY QUITE A BIT AND HEAVIER MAGNITUDE COULD OCCUR UNDER MORE PERSISTENT AREAS OF STORMS. SOMEWHAT DRY ANTECEDENT CONDITIONS PRECLUDE ANY TYPE OF FLASH FLOOD WATCH ISSUANCE. FLASH FLOOD GUIDANCE FROM THE RIVER FORECAST CENTER CALLS FOR TWO INCHES OR MORE PER SIX HOURS NEEDED IN MOST LOCATIONS TO WARRANT A HEIGHTENED THREAT. WILL STILL NEED TO MONITOR CLOSELY...ESPECIALLY CONSIDERING MONDAY AFTERNOON AND EVENING ARE LIKELY TO PRESENT STORMS...SOME OF WHICH WILL AGAIN BE CAPABLE OF HEAVY RAIN. THE COMBINED EFFECTS THROUGH THE NEXT 48 HOURS COULD CAUSE SOME RIVERS TO RISE TO NEAR FLOOD STAGE BASED ON PREDICTIONS USING A SUITE OF COMPUTER MODELS. MTF && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * -SHRA THROUGH THE EVENING WITH ISOLATED TS PRIOR TO 01Z. * ADDITIONAL ROUNDS OF SHRA AND PROBABLY EMBEDDED TSRA OVERNIGHT AND MONDAY MORNING. TRIED TO TIME THE MOST LIKELY WINDOWS IN THE TAF BUT TIMING MAY WELL CHANGE. * STEADY EASTERLY WINDS GUSTING TO AROUND 25 KT AT TIMES TONIGHT/MONDAY. * CIGS LOWERING TO MVFR THEN IFR TONIGHT/MONDAY MORNING...MAY NEED TO SLOW ARRIVAL TIMING. * ORGANIZED SHRA/TSRA POSSIBLE LATE AFTERNOON/EARLY EVENING MONDAY. MDB //DISCUSSION...UPDATED 00Z... THUNDERSTORM FORECAST REMAINS A CHALLENGE THIS EVENING. THUNDER THAT POPPED NEAR THE CHI TERMINALS LAST 1-2 HOURS HAS FADED FOR THE MOST PART WITH JUST ABOUT ALL LIGHT RAIN UPSTREAM TO THE SOUTH. MORE ORGANIZED CONVECTION ACROSS NORTHWEST IL IS TRACKING NORTHEAST AND FADING BUT DO EXPECT SOME THUNDER TO CROSS THE RFD AREA AND POINTS NORTHWEST OF ORD PRIOR TO 02 OR 03Z. OTHERWISE SHRA WILL PERSIST THROUGH THE EVENING. SHRA/TSRA OVER CENTRAL MISSOURI APPEARS TO BE THE NEXT ORGANIZED ACTIVITY TO AFFECT THE AREA EARLY TONIGHT. THERE THEN APPEARS TO BE A GAP IN COVERAGE TO SOME DEGREE LATER TONIGHT BEFORE ANOTHER ROUND OF SHRA/TSRA AFFECTS THE AREA MONDAY MORNING IN CONJUNCTION WITH AN UPPER TROUGH MOVING FROM NW ARKANSAS. CIGS WILL LIKELY LOWER WITH TIME TONIGHT BUT HAVE SLOWED THE ARRIVAL OF IFR BY SEVERAL HOURS AND MAY STILL BE TOO FAST WITH THE LOWERING OVERALL. WINDS HAVE ABATED FOR NOW BUT SHOULD COME BACK UP AND REMAIN STEADY FROM THE EAST. SHOULD SPEEDS NOT COME UP AS MUCH AS EXPECTED THEN LOW LEVEL WIND SHEAR MAY BECOME DEVELOP AS SPEEDS INCREASE TO AROUND 50 KT BY 2000 FT AGL. THERE MAY BE A BREAK IN OVERALL ACTIVITY FOR A TIME FROM MIDDAY THROUGH EARLY OR MID AFTERNOON MONDAY BUT A WARM FRONT WILL BE STRENGTHENING SOUTH OF THE TERMINALS THROUGH THE DAY AND GRADUALLY LIFTING NORTHWARD. THIS IS EXPECTED TO TRIGGER SHRA/TSRA BY MID OR LATE AFTERNOON THAT WILL LIFT NORTH INTO THE EVENING. HAVE FAIRLY GOOD CONFIDENCE IN THIS SCENARIO SO HAVE ADDED A SEVERAL HOUR WINDOW OF TSRA TO THE TAFS LATER MONDAY AFTERNOON. TIMING MAY NEED TO BE SHIFTED HOWEVER. OVERALL THERE IS A RISK FOR SHRA/TSRA AT JUST ABOUT ANY TIME THROUGH TOMORROW EVENING BUT TRIED TO IDENTIFY THE MOST LIKELY PERIODS IN THE TAF. MDB //ORD AND MDW CONFIDENCE...UPDATED 00Z... * MEDIUM-HIGH CONFIDENCE THAT MAINLY -SHRA WILL AFFECT THE TERMINALS THROUGH THE EVENING WITH TS WANING NEXT HOUR OR SO. COULD STILL SEE A ROGUE STORM POP UP HOWEVER. * MEDIUM-HIGH CONFIDENCE IN WIND TRENDS. * MEDIUM-HIGH CONFIDENCE IN CIGS LOWERING LATER TONIGHT...LOW- MEDIUM CONFIDENCE IN TIMING. * MEDIUM-HIGH CONFIDENCE IN SHRA/TSRA OCCURRING LATER MONDAY...MEDIUM CONFIDENCE IN TIMING. MDB //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY...CHANCE RAIN AND THUNDER...MVFR LIKELY WITH IFR POSSIBLE. WEDNESDAY - SATURDAY...CHANCE RAIN...MVFR LIKELY WITH IFR POSSIBLE. MDB && .MARINE... 243 PM CDT THE PRIMARY FEATURE THAT WILL BE DOMINATING CONDITIONS OVER THE LAKE FOR THE NEXT FEW DAYS WILL BE A LARGE LOW PRESSURE SYSTEM MOVING THROUGH THE PLAINS AND HEADING SLOWLY TOWARD THE WESTERN GREAT LAKES. THE WARM FRONT EXTENDING EAST FROM THIS LOW IS STAYING SOUTH OF THE LAKE SO FAR...BUT IS SUPPORTING A TIGHT PRESSURE GRADIENT AND STRONG EASTERLY WINDS OVER THE LAKE. MEASURED GUSTS AT LAND BASED POINTS AROUND THE LAKE THIS AFTERNOON ARE IN THE NEIGHBORHOOD OF 25 KTS BUT WILL BE INCREASING THROUGH THE EVENING...EVENTUALLY TO GALES. THIS FITS WITH THE WIND OBSERVATIONS IN THE UPPER TEENS WE ARE SEEING SO FAR FROM SHIPS ON THE LAKE...THOUGH THERE ARE MANY MORE SHIPS OUT THERE THAN SHIP OBSERVATIONS TODAY...SO SOME VESSELS MAY BE SEEING DIFFERENT VALUES. THE WARM FRONT FINALLY REACHES THE SOUTHERN LAKE MONDAY NIGHT. THIS WILL RELAX THE GRADIENT SOMEWHAT...ESPECIALLY ACROSS THE SOUTH HALF...SO THIS IS WHEN WE HAVE THE GALE WARNING CURRENTLY SET TO EXPIRE. THERE IS A CHANCE THAT THE WARNING OVER THE NORTH HALF MAY NEED TO BE EXTENDED INTO THE DAYTIME HOURS TUESDAY. LENNING && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM SUNDAY. GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741- LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872- LMZ874-LMZ876-LMZ878...10 PM SUNDAY TO 10 PM MONDAY. GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567- LMZ868...3 AM MONDAY TO 10 PM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 646 PM CDT Sun Apr 27 2014 .DISCUSSION... ISSUED 302 PM CDT Sun Apr 27 2014 Models in good agreement with the overall pattern and surface features. Differences are in the small mesoscale features and environmental changes due to the storms moving through the area currently. Concerns this package will be storm system moving into the area late this afternoon and through this evening. Then another round of severe weather is possible tomorrow afternoon through tomorrow evening. Models continue to look similar with mid and long range models showing the upper level low sitting over the area and spinning for rest of the week. This means unsettled weather for the middle and latter part of the work week. SHORT TERM...Tonight through Wednesday Line of strong to severe storms is moving across northern MO and will reach into western IL in a couple of hours. SPC has issued a severe watch til 9pm to cover this line of storms. Large hail and damaging winds look to be the primary threat, though an isolated tornado is not out of the question. Occasional thunderstorms will continue late this afternoon and into tonight. Once the line of storms moves through, there will likely be a break in the pcpn over some of the area. However, with the warm front becoming active, pcpn could continue on and off through the night. So will continue high pops over the area. CWA will be well entrenched in the warm sector tomorrow and the break in the pcpn will likely continue during the early morning hours. However, things will become active during the late morning hours again as the dry line moves toward the area. Severe weather is again likely from late morning through the afternoon with the dry line. Will be plenty of instability and sufficient shear for some storm to rotate. Plus, the cutoff 500mb low is a cold core. So, good lapse rates to support hail. SVR threat looks to be hail and wind, along with tornadoes closer to the lower pressure area that will be northwest of the cwa during the afternoon. Thunderstorms will be possible again Tuesday as the low pressure area pulls east and northeast of the area. Then Tue night and Wed, with the upper level low still rotating around northern IL, diurnal showers will remain possible through mid week. Temps will remain warm, but then cool off on Wed after the upper level system gets closer to the area with cooler air. LONG TERM...Wednesday night through Sunday The upper level system will remain near the area through the rest of the week. This will continue to bring diurnal showers to the region through Saturday. Then am expecting a change in the pattern for the rest of the weekend, though another system is forecast to bring pcpn on Sunday. Temps will remain on the cool side through the period as upper level troughiness continues through the rest of the week and into the weekend. A more zonal flow looks possible by end of the weekend. && .AVIATION... ISSUED 645 PM CDT Sun Apr 27 2014 Scattered showers and thunderstorms will affect the central IL airports this evening, especially the I-74 taf sites with MVFR vsbys and ceilings possible. Visibility dropped below 2 miles at CMI with heavy rain but this will be brief. HRRR shows a widespread band of showers and thunderstorms lifting ne across central IL and brought in MVFR ceilings and visibilities again. Could be lull in convection Monday morning with more redevelopment in unstable air mass during Monday afternoon with MVFR conditions returning. ENE winds have diminish for a time early this morning to 10-15 kts and gusts 15-25 kts to veer se and increase to 15-20 kts with gusts to around 25 kts overnight and then turn SSE on Monday. Strong low pressure of 984 mb over north central KS to lift ne to NE/IA border by Monday afternoon while lifting warm front from sw IL through central IL during overnight and into northern IL Monday. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1147 PM CDT FRI APR 25 2014 .SYNOPSIS... ISSUED AT 238 PM CDT FRI APR 25 2014 BEAUTIFUL DAY TODAY WITH PLENTIFUL SUNSHINE AND TEMPERATURES AS OF 2 PM ALREADY IN THE UPPER 60S/LOW 70S AREA WIDE. DEWPOINTS HAVE MANAGED TO STAY IN THE 40S THROUGH MUCH OF THE MORNING AND ARE ONLY NOW DROPPING INTO THE 30S. UPPER AIR ANALYSIS THIS MORNING DEPICTED CUTOFF UPPER LOW SPINNING OVER NORTHEAST MINNESOTA AND LAKE SUPERIOR WITH BROAD RIDGING TAKING PLACE FROM WESTERN KANSAS INTO ALBERTA CANADA. AT THE SURFACE...WEAK RIDGING THAT WAS OVER THE CWA HAS NOW PUSHED EAST INTO INDIANA. A WEAK COLD FRONT WAS SEEN SLOWLY PUSHING SOUTH OVER MINNESOTA WITH MAINLY MID-HIGH LEVEL CLOUDS SEEN BEHIND THE FRONT. LATEST WV IMAGERY SHOWS STRONG SYSTEM JUST OFF THE WEST COAST. THIS SYSTEM WILL BRING UNSETTLED WEATHER TO THE REGION THIS WEEKEND AND BEYOND. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 238 PM CDT FRI APR 25 2014 FORECAST FOCUS ON SMALL CHANCE OF PCPN THIS EVENING...OTHERWISE QUIET AND DRY CONDITIONS EXPECTED. WEAK COLD FRONT OVER MINNESOTA WILL DROP SOUTH ACROSS THE CWA TONIGHT AND STALL AS IT REACHES THE IOWA-MISSOURI BORDER. HI-RES MODELS AND THE LATEST RAP TRENDS ALL SHOW LOW LEVEL CONVERGENCE... OMEGAS...AND MOISTURE IN THE 850-700MB LAYER ALONG AND BEHIND THE FRONT INCREASING TONIGHT AND SHOULD BE SUFFICIENT ENOUGH TO PRODUCE VERY LIGHT SHOWERS OR SPRINKLES MAINLY NORTH AND EAST OF A LINE FROM THE QUAD CITIES TO PRINCETON ILLINOIS. HAVE MAINTAINED SLIGHT CHANCE POPS IN THIS AREA FOR THIS POSSIBILITY. I AM CONCERNED THAT THE SURFACE TO 850MB LAYER MAY BE TOO DRY FOR ANY PCPN TO REACH THE GROUND AND WILL PASS THIS ON TO THE NIGHT SHIFT. WINDS TO GRADUALLY SHIFT TO THE NORTHEAST AS FRONT TRACKS THROUGH THE CWA. OVERNIGHT LOW TEMPERATURES WILL DEPEND ON HOW FAST THE FRONT MOVES THROUGH AND ITS POSITION EARLY SATURDAY. LOWS SHOULD RANGE FROM THE UPPER 30S/LOW 40S ON THE COOL SIDE OF THE BOUNDARY TO THE LOWER 50S IN THE FAR SOUTH. SATURDAY...ANOTHER PLEASANT DAY IN STORE AS UPPER LEVEL RIDGING MOVES ACROSS THE AREA. A FRONTAL BOUNDARY WILL BE SITUATED ACROSS THE SOUTHERN PORTIONS OF THE CWA WITH WINDS MAINLY FROM THE EAST DURING THE DAY. THIS WILL RESULT IN A LARGE TEMPERATURE GRADIENT SETTING UP ACROSS THE AREA BY THE AFTERNOON. DEEP MIXING TO 900MB AND PARTLY SUNNY SKIES THROUGH AT LEAST THE EARLY AFTERNOON WILL ALLOW HIGHS TO REACH THE LOWER 60S IN THE NORTHEAST TO THE UPPER 70S IN THE FAR SOUTH. AN ACTIVE PATTERN BEGINS ACROSS THE MIDWEST STARTING SATURDAY NIGHT...SEE LONG TERM DISCUSSION FOR MORE DETAILS. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 248 PM CDT FRI APR 25 2014 MODELS CONTINUE TO SHOW A HIGHLY AMPLIFIED...BLOCKED...PATTERN EVOLVING OVER THE CONSUS DURING THE WEEKEND. THIS WILL RESULT IN A LARGE OCCLUDED SYSTEM BECOMING NEARLY STATIONARY OVER THE UPPER MIDWEST FOR MUCH OF THE COMING WEEK. THIS PATTERN CONTINUES TO SUPPORT A PROLONGED RAINFALL EVENT OVER THE MID MISSISSIPPI VALLEY WITH SIGNIFICANT RAINFALL...RESULTING IN FLOODING ON AREA TRIBUTARIES AND THE MISSISSIPPI RIVER. SATURDAY NIGHT SURFACE CYCLOGENESIS WILL TAKE PLACE OVER THE WESTERN PLAINS...AHEAD OF A DEEP UPPER TROF MOVING THROUGH THE WESTERN U.S. AS THE SURFACE LOW FORMS A WARM FRONT WILL DEVELOP FROM THE CENTRAL PLAINS THROUGH NORTHERN MISSOURI. DEEP SOUTHERN FLOW AHEAD OF THE WESTERN TROF WILL BRING ABUNDANT GULF MOISTURE NORTH ACROSS THE WARM FRONT. THE LOW LEVEL JET BY LATE SATURDAY EVENING SHOULD BE POINTED AT EASTERN NE AND WESTERN IA PROVIDING FORCING FOR MCS DEVELOPMENT. THE MCS SHOULD TRACK EAST OVERNIGHT REACHING EASTERN IA DURING THE EARLY MORNING HOURS. WHILE THE THREAT OF SEVERE STORMS WITH THIS MCS WILL BE THE GREATEST OVER WESTERN IA AND EASTERN NE...SOME ISOLATED SEVERE STORMS COULD REACH PARTS OF EASTERN IOWA AFTER MIDNIGHT WITH HAIL BEING THE GREATEST THREAT. SUNDAY AND SUNDAY NIGHT THE SEVERE THREAT WILL INCREASE FOR THE MID MISSISSIPPI VALLEY AS THE WARM FRONT MOVES INTO NORTHERN MO OR SOUTHERN IA AND CENTRAL IL AND STRONG MID LEVEL FLOW AHEAD OF THE UPPER LOW MOVES NORTH THROUGH THE REGION. THE GREATEST THREAT OF SEVERE STORMS SHOULD BE SUNDAY AFTERNOON AND EVENING ALONG AND SOUTH OF INTERSTATE 80. HAIL SHOULD BE THE PRIMARY THREAT WITH MODELS SHOWING SOME MID LEVEL DRYING. HOWEVER NEAR AND SOUTH OF THE WARM FRONT DAMAGING WINDS AND TORNADIC STORMS CAN/T BE RULED OUT. HEAVY RAIN POTENTIAL WILL EXIST OVER MUCH OF THE AREA FROM LATE SATURDAY NIGHT THROUGH SUNDAY NIGHT AND POSSIBLY INTO MONDAY AS THE SYSTEM MOVES TOWARD THE REGION. THIS MORNINGS WPC 3 DAY TOTAL QPF ENDING MONDAY MORNING SHOWED A LARGE AREA OF 1 TO 3 INCHES OVER MUCH OF THE FORECAST AREA...ROUGHLY CENTERED ALONG I80. THIS LOOKS REASONABLE GIVEN PW/S OF 1 TO 1.5 INCHES OVER THE AREA MUCH OF THE WEEKEND AND THE SLOW MOVEMENT OF THE OCCLUDED SYSTEM. AFTER MONDAY MOST MODELS SHOW THE UPPER LOW OVER THE MISSISSIPPI VALLEY AND MOVING SLOWLY EAST MID TO LATE WEEK. THIS SHOULD KEEP MORE SHOWERY TYPE PRECIPITATION OVER THE AREA AT LEAST THROUGH THURSDAY AND POSSIBLY INTO FRIDAY. ISOLATED THUNDERSTORMS WILL BE POSSIBLE DURING THE AFTERNOON AND EVENING HOURS MONDAY AND TUESDAY WITH SURFACE DEWPOINTS STILL IN THE 50S AND THE COLD POOL ASSOCIATED WITH UPPER LOW STILL OVER HEAD. BY MID TO LATE WEEK DRY SURFACE AIR MOVING IN SHOULD END THE THUNDERSTORM THREAT. TEMPERATURES SHOULD BE NEAR NORMAL FOR THE WEEKEND THEN TREND BELOW NORMAL...ESPECIALLY THE HIGHS...FOR MUCH OF THE UPCOMING WEEK WITH ABUNDANT CLOUDS EXPECTED TO BE OVER THE AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1141 PM CDT FRI APR 25 2014 VFR CONDITIONS EXPECTED TO PERSIST THROUGH SATURDAY EVENING. WINDS WILL BECOME EASTERLY AT OR ABOVE 10 KTS WITH OCCASIONAL GUSTS AROUND 20 KTS POSSIBLE FROM MID AFTERNOON THROUGH EVENING. ELEVATED WARM ADVECTION MAY RESULT IN SCATTERED SHOWERS DEVELOPING SATURDAY EVENING...WITH INCREASING CHANCES MAINLY JUST BEYOND END OF THE TAF CYCLE. && .HYDROLOGY... ISSUED AT 248 PM CDT FRI APR 25 2014 THREAT OF FLOODING ON AREA TRIBUTARIES AND THE MISSISSIPPI RIVER WILL INCREASE BY EARLY NEXT WEEK AS A WIDESPREAD SIGNIFICANT RAINFALL EVENT OCCURS OVER THE REGION. CURRENT FORECASTS SUGGEST A WIDESPREAD AREA OF 1 TO 4 INCHES OF RAIN ARE POSSIBLE OVER MUCH OF THE FORECAST AREA BY WEDNESDAY. LOCALLY HEAVY RAINS WILL BE POSSIBLE FROM LATE SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH SCATTERED SHOWERS EXPECTED OVER THE AREA EARLY TO MIDWEEK. SINCE THE PRECIPITATION IS GOING TO OCCUR OVER AN EXTENDED PERIOD OF TIME THE THREAT OF FLASH FLOODING WILL BE LOW. HOWEVER RIVER FLOODING IS EXPECTED WITH MANY OF THE AREA TRIBUTARIES AND THE MISSISSIPPI RIVER SEEING AT LEAST MINOR TO MODERATE FLOODING BY THE MIDDLE OF NEXT WEEK. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...GROSS SHORT TERM...GROSS LONG TERM...DLF AVIATION...05 HYDROLOGY...DLF
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1229 PM CDT Sat Apr 26 2014 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 403 AM CDT SAT APR 26 2014 The center of an intense upper level trough was located over southern CA at 7Z. The upper level trough will lift northeast across the desert southwest this afternoon, and then lift negative tilt into southeast CO and across west TX by 12Z SUN. Early this morning elevated showers were beginning to develop as isentropic lift was developing ahead of residual 850mb moisture return. The HRRR along with the ECMWF show the stronger thunderstorms developing just east of the CWA after 12Z. The 00Z NAM shows isolated elevated thunderstorms developing along and south of the KS turnpike by 10Z, then moving east of the CWA during the mid and late morning hours. Given MUCAPES of 400-1000 J/KG and effective 0-6KM shear of 30 KTS, some of these storms may produce small hail and the stronger storms may even produce quarter size hail across portions of east central KS this morning, that is if storms develop within the CWA. As an 80kt jet max within the base of the H5 trough lifts northeast across eastern NM, a lee surface trough across southeast CO, southward along the NM/TX border will deepen. This will increase the southerly 850mb winds to 40 KTS across central KS with surface wind increasing 20 to 30 KTS across most of KS. At this time the strongest surface winds should remain just southwest and west of the CWA. The southwest counties of the CWA may come close to wind advisory criteria during the afternoon hours with sustained winds of 28 MPH and gusts to near 40 MPH. A surface dryline will develop early this afternoon within the lee trough axis across extreme southwest KS, then southward across the TX PNHDL. This dryline will then move northeast into west central KS and extend southward across extreme western OK by late this afternoon. At this time the deepest gulf moisture was located across southern TX and most models show a quick transport of deep moisture northward into south central KS by this afternoon. Deeper mixing across central KS may keep dewpoints in the mid to upper 50s ahead of the surface dryline. Both the the 6Z NAM and 00Z Advanced Research WRF show a strong CAP ahead of the dryline across central KS with no storms developing in the late afternoon or evening hours. The 12Z ECMWF model shows the potential for thunderstorms developing along the dryline across south central KS and north central KS east of HLC. All the models show temperature and dewpoint temperature depressions greater than 25 degrees along the dryline across central and north central KS. Therefore, if storms develop they will be high based with MLLCL`s of 5,000 to 6,000 feet. The environment across central KS will have MLCAPES of 3500 J/KG and Effective shear of 40 KTS. If storms were able to develop the environment would be favorable for high based supercell thunderstorms. The higher storm bases will significantly decrease the potential for tornadoes as these isolated supercell thunderstorms move northeast off the dryline into the western counties of the CWA early this evening. In fact they may weaken as the supercells leave the best area of surface convergence. However, if any high based supercell manages to develop along the dryline across north central and central KS, these storms will be capable of producing large hail and damaging wind gusts. Highs Today will range from the lower 80s across the northeast counties to the upper 80s to near 90 across the southwest counties of the CWA. I think we will see a break across the CWA from any thunderstorms from the mid evening hours until 3 or 4 AM Sunday morning, before severe thunderstorms redevelop. Supercell thunderstorms across western and central OK will merge into a QLCS or MCS and lift northeast into south central KS after midnight. Once piece of the upper level trough will pivot northward across western and central OK, then into eastern KS through the early morning hours of Sunday. This will probably maintain any QLCS or MCS cluster of severe thunderstorms that develop across northern OK and southern KS, as these storms move northeast ahead of the first H5 trough across the eastern half of the CWA. The primary hazard with the cluster of severe thunderstorms will be large hail along with the threat for damaging winds. I cannot rule out a few supercell thunderstorms on the southern edge of the severe cluster of thunderstorms. Any supercells or meso vortices within a QLCS may bring a low chance for an isolated tornado through early morning hours of Sunday across portions of east central KS. The MCS/cluster of severe thunderstorms may also bring heavy rainfall. It will be more of a mesoscale forecast but areas along and south of the KS turnpike may see the heaviest rainfall near 12Z SUN. Overnight lows will only drop into the lower to mid 60s Saturday night. .LONG TERM...(Sunday through Friday) Issued at 403 AM CDT SAT APR 26 2014 The most concentrated and potentially strongest convection still appears to be on Sunday over the eastern 2/3 of the cwa in the morning and the eastern 1/3 in the afternoon as the main shortwave lobe over southwest KS at 12z Sunday lifts northeastward across KS through the day. Strong to severe convection appears will be ongoing to start the day Sunday across much of the cwa...gradually shifting eastward ahead of dry slot in central KS...although models such as the EC hinting that the cwa could be on the northern fringe of a substantial MCS just to the south. Models keep MUCAPE values in the 1500-2000 J/kg range ahead of the dryline...however 0-6km Bulk Shear values steadily increase into the 50-60kt range through 18z over the eastern half of the cwa or near and just ahead of dryline. Although large hail...wind is possible with the morning convection...any additional development by midday/afternoon in any increasingly sheared environment would become more supportive of supercells with all modes of severe weather possible including a tornado threat. This will be highly dependent on the speed/timing of the dryline and its proximity to afternoon heating just of the mid level drying. Although will leave a slight chance for some lingering convection early evening in the far eastern counties...it still appears the threat for severe weather will shift east of the cwa by 00Z as drier air continues to push eastward across the area as the upper low slows and occludes over western Nebraska. Cannot totally rule out a few showers developing over the cwa on Monday as the upper low wobbles eastward and moisture wraps around the circulation center and back into the cwa...but will word as showers for now as instability looks weak. Rain chances will then linger through Wednesday...then again on Thursday as another shortwave trough rotates southeast around the upper trough. Rainfall amounts across the area through mid week should remain light. High temperatures still expected to cool from the 70s on Sunday to the 60s/near 70 Monday...then the 50s and 60s through the remainder of the week. Lows will commonly be in the 40s Tuesday through Friday. && .AVIATION...(For the 18Z TAFs through 18Z Sunday Afternoon) Issued at 1223 PM CDT SAT APR 26 2014 VFR prevails as strong southerly winds gust between 30 and 35 kts through 01Z. Speeds weaken slightly however remain strong above 15 kts sustained through end of TAF period as strong upper disturbance approaches. Therefore LLWS should not be an issue as long as winds stay up. Delayed onset of VCTS being in the area until 09Z at KMHK and 10Z at KTOP/KFOE. High resolution models develop SCT TS after midnight in southern KS, lifting north and east towards terminals by Sunday morning. Thunderstorms are possible through 18Z. Strong warm advection and moistening boundary layer aft 09Z will lower ceilings to MVFR. IFR or lower is possible if storms directly impact terminals. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Gargan LONG TERM...63 AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS TOPEKA KS
653 AM CDT Sat Apr 26 2014 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 403 AM CDT SAT APR 26 2014 The center of an intense upper level trough was located over southern CA at 7Z. The upper level trough will lift northeast across the desert southwest this afternoon, and then lift negative tilt into southeast CO and across west TX by 12Z SUN. Early this morning elevated showers were beginning to develop as isentropic lift was developing ahead of residual 850mb moisture return. The HRRR along with the ECMWF show the stronger thunderstorms developing just east of the CWA after 12Z. The 00Z NAM shows isolated elevated thunderstorms developing along and south of the KS turnpike by 10Z, then moving east of the CWA during the mid and late morning hours. Given MUCAPES of 400-1000 J/KG and effective 0-6KM shear of 30 KTS, some of these storms may produce small hail and the stronger storms may even produce quarter size hail across portions of east central KS this morning, that is if storms develop within the CWA. As an 80kt jet max within the base of the H5 trough lifts northeast across eastern NM, a lee surface trough across southeast CO, southward along the NM/TX border will deepen. This will increase the southerly 850mb winds to 40 KTS across central KS with surface wind increasing 20 to 30 KTS across most of KS. At this time the strongest surface winds should remain just southwest and west of the CWA. The southwest counties of the CWA may come close to wind advisory criteria during the afternoon hours with sustained winds of 28 MPH and gusts to near 40 MPH. A surface dryline will develop early this afternoon within the lee trough axis across extreme southwest KS, then southward across the TX PNHDL. This dryline will then move northeast into west central KS and extend southward across extreme western OK by late this afternoon. At this time the deepest gulf moisture was located across southern TX and most models show a quick transport of deep moisture northward into south central KS by this afternoon. Deeper mixing across central KS may keep dewpoints in the mid to upper 50s ahead of the surface dryline. Both the the 6Z NAM and 00Z Advanced Research WRF show a strong CAP ahead of the dryline across central KS with no storms developing in the late afternoon or evening hours. The 12Z ECMWF model shows the potential for thunderstorms developing along the dryline across south central KS and north central KS east of HLC. All the models show temperature and dewpoint temperature depressions greater than 25 degrees along the dryline across central and north central KS. Therefore, if storms develop they will be high based with MLLCL`s of 5,000 to 6,000 feet. The environment across central KS will have MLCAPES of 3500 J/KG and Effective shear of 40 KTS. If storms were able to develop the environment would be favorable for high based supercell thunderstorms. The higher storm bases will significantly decrease the potential for tornadoes as these isolated supercell thunderstorms move northeast off the dryline into the western counties of the CWA early this evening. In fact they may weaken as the supercells leave the best area of surface convergence. However, if any high based supercell manages to develop along the dryline across north central and central KS, these storms will be capable of producing large hail and damaging wind gusts. Highs Today will range from the lower 80s across the northeast counties to the upper 80s to near 90 across the southwest counties of the CWA. I think we will see a break across the CWA from any thunderstorms from the mid evening hours until 3 or 4 AM Sunday morning, before severe thunderstorms redevelop. Supercell thunderstorms across western and central OK will merge into a QLCS or MCS and lift northeast into south central KS after midnight. Once piece of the upper level trough will pivot northward across western and central OK, then into eastern KS through the early morning hours of Sunday. This will probably maintain any QLCS or MCS cluster of severe thunderstorms that develop across northern OK and southern KS, as these storms move northeast ahead of the first H5 trough across the eastern half of the CWA. The primary hazard with the cluster of severe thunderstorms will be large hail along with the threat for damaging winds. I cannot rule out a few supercell thunderstorms on the southern edge of the severe cluster of thunderstorms. Any supercells or meso vortices within a QLCS may bring a low chance for an isolated tornado through early morning hours of Sunday across portions of east central KS. The MCS/cluster of severe thunderstorms may also bring heavy rainfall. It will be more of a mesoscale forecast but areas along and south of the KS turnpike may see the heaviest rainfall near 12Z SUN. Overnight lows will only drop into the lower to mid 60s Saturday night. .LONG TERM...(Sunday through Friday) Issued at 403 AM CDT SAT APR 26 2014 The most concentrated and potentially strongest convection still appears to be on Sunday over the eastern 2/3 of the cwa in the morning and the eastern 1/3 in the afternoon as the main shortwave lobe over southwest KS at 12z Sunday lifts northeastward across KS through the day. Strong to severe convection appears will be ongoing to start the day Sunday across much of the cwa...gradually shifting eastward ahead of dry slot in central KS...although models such as the EC hinting that the cwa could be on the northern fringe of a substantial MCS just to the south. Models keep MUCAPE values in the 1500-2000 J/kg range ahead of the dryline...however 0-6km Bulk Shear values steadily increase into the 50-60kt range through 18z over the eastern half of the cwa or near and just ahead of dryline. Although large hail...wind is possible with the morning convection...any additional development by midday/afternoon in any increasingly sheared environment would become more supportive of supercells with all modes of severe weather possible including a tornado threat. This will be highly dependent on the speed/timing of the dryline and its proximity to afternoon heating just of the mid level drying. Although will leave a slight chance for some lingering convection early evening in the far eastern counties...it still appears the threat for severe weather will shift east of the cwa by 00Z as drier air continues to push eastward across the area as the upper low slows and occludes over western Nebraska. Cannot totally rule out a few showers developing over the cwa on Monday as the upper low wobbles eastward and moisture wraps around the circulation center and back into the cwa...but will word as showers for now as instability looks weak. Rain chances will then linger through Wednesday...then again on Thursday as another shortwave trough rotates southeast around the upper trough. Rainfall amounts across the area through mid week should remain light. High temperatures still expected to cool from the 70s on Sunday to the 60s/near 70 Monday...then the 50s and 60s through the remainder of the week. Lows will commonly be in the 40s Tuesday through Friday. && .AVIATION...(For the 12Z TAFs through 12Z Sunday Morning) Issued at 648 AM CDT SAT APR 26 2014 Isolated thunderstorms may develop in the vicinity of terminals KTOP and KFOE through 14Z SAT. Expect VFR conditions through most of the next 24 hours. Thunderstorms may move into the terminals after 8Z SUN and continue through the morning hours. Any thunderstorm may bring Brief MVFR ceilings and visibilities through the early morning hours of Sunday. South-Southeast winds will increase to 14 to 20 KTS with gusts of 22 to 30 KTS. Winds gust may diminish slightly after 00Z SUN. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Gargan LONG TERM...63 AVIATION...Gargan
AREA FORECAST DISCUSSION
NWS TOPEKA KS
423 AM CDT Sat Apr 26 2014 .SHORT TERM...(Today and Tonight) Issued at 403 AM CDT SAT APR 26 2014 The center of an intense upper level trough was located over southern CA at 7Z. The upper level trough will lift northeast across the desert southwest this afternoon, and then lift negative tilt into southeast CO and across west TX by 12Z SUN. Early this morning elevated showers were beginning to develop as isentropic lift was developing ahead of residual 850mb moisture return. The HRRR along with the ECMWF show the stronger thunderstorms developing just east of the CWA after 12Z. The 00Z NAM shows isolated elevated thunderstorms developing along and south of the KS turnpike by 10Z, then moving east of the CWA during the mid and late morning hours. Given MUCAPES of 400-1000 J/KG and effective 0-6KM shear of 30 KTS, some of these storms may produce small hail and the stronger storms may even produce quarter size hail across portions of east central KS this morning, that is if storms develop within the CWA. As an 80kt jet max within the base of the H5 trough lifts northeast across eastern NM, a lee surface trough across southeast CO, southward along the NM/TX border will deepen. This will increase the southerly 850mb winds to 40 KTS across central KS with surface wind increasing 20 to 30 KTS across most of KS. At this time the strongest surface winds should remain just southwest and west of the CWA. The southwest counties of the CWA may come close to wind advisory criteria during the afternoon hours with sustained winds of 28 MPH and gusts to near 40 MPH. A surface dryline will develop early this afternoon within the lee trough axis across extreme southwest KS, then southward across the TX PNHDL. This dryline will then move northeast into west central KS and extend southward across extreme western OK by late this afternoon. At this time the deepest gulf moisture was located across southern TX and most models show a quick transport of deep moisture northward into south central KS by this afternoon. Deeper mixing across central KS may keep dewpoints in the mid to upper 50s ahead of the surface dryline. Both the the 6Z NAM and 00Z Advanced Research WRF show a strong CAP ahead of the dryline across central KS with no storms developing in the late afternoon or evening hours. The 12Z ECMWF model shows the potential for thunderstorms developing along the dryline across south central KS and north central KS east of HLC. All the models show temperature and dewpoint temperature depressions greater than 25 degrees along the dryline across central and north central KS. Therefore, if storms develop they will be high based with MLLCL`s of 5,000 to 6,000 feet. The environment across central KS will have MLCAPES of 3500 J/KG and Effective shear of 40 KTS. If storms were able to develop the environment would be favorable for high based supercell thunderstorms. The higher storm bases will significantly decrease the potential for tornadoes as these isolated supercell thunderstorms move northeast off the dryline into the western counties of the CWA early this evening. In fact they may weaken as the supercells leave the best area of surface convergence. However, if any high based supercell manages to develop along the dryline across north central and central KS, these storms will be capable of producing large hail and damaging wind gusts. Highs Today will range from the lower 80s across the northeast counties to the upper 80s to near 90 across the southwest counties of the CWA. I think we will see a break across the CWA from any thunderstorms from the mid evening hours until 3 or 4 AM Sunday morning, before severe thunderstorms redevelop. Supercell thunderstorms across western and central OK will merge into a QLCS or MCS and lift northeast into south central KS after midnight. Once piece of the upper level trough will pivot northward across western and central OK, then into eastern KS through the early morning hours of Sunday. This will probably maintain any QLCS or MCS cluster of severe thunderstorms that develop across northern OK and southern KS, as these storms move northeast ahead of the first H5 trough across the eastern half of the CWA. The primary hazard with the cluster of severe thunderstorms will be large hail along with the threat for damaging winds. I cannot rule out a few supercell thunderstorms on the southern edge of the severe cluster of thunderstorms. Any supercells or meso vortices within a QLCS may bring a low chance for an isolated tornado through early morning hours of Sunday across portions of east central KS. The MCS/cluster of severe thunderstorms may also bring heavy rainfall. It will be more of a mesoscale forecast but areas along and south of the KS turnpike may see the heaviest rainfall near 12Z SUN. Overnight lows will only drop into the lower to mid 60s Saturday night. .LONG TERM...(Sunday through Friday) Issued at 403 AM CDT SAT APR 26 2014 The most concentrated and potentially strongest convection still appears to be on Sunday over the eastern 2/3 of the cwa in the morning and the eastern 1/3 in the afternoon as the main shortwave lobe over southwest KS at 12z Sunday lifts northeastward across KS through the day. Strong to severe convection appears will be ongoing to start the day Sunday across much of the cwa...gradually shifting eastward ahead of dry slot in central KS...although models such as the EC hinting that the cwa could be on the northern fringe of a substantial MCS just to the south. Models keep MUCAPE values in the 1500-2000 J/kg range ahead of the dryline...however 0-6km Bulk Shear values steadily increase into the 50-60kt range through 18z over the eastern half of the cwa or near and just ahead of dryline. Although large hail...wind is possible with the morning convection...any additional development by midday/afternoon in any increasingly sheared environment would become more supportive of supercells with all modes of severe weather possible including a tornado threat. This will be highly dependent on the speed/timing of the dryline and its proximity to afternoon heating just of the mid level drying. Although will leave a slight chance for some lingering convection early evening in the far eastern counties...it still appears the threat for severe weather will shift east of the cwa by 00Z as drier air continues to push eastward across the area as the upper low slows and occludes over western Nebraska. Cannot totally rule out a few showers developing over the cwa on Monday as the upper low wobbles eastward and moisture wraps around the circulation center and back into the cwa...but will word as showers for now as instability looks weak. Rain chances will then linger through Wednesday...then again on Thursday as another shortwave trough rotates southeast around the upper trough. Rainfall amounts across the area through mid week should remain light. High temperatures still expected to cool from the 70s on Sunday to the 60s/near 70 Monday...then the 50s and 60s through the remainder of the week. Lows will commonly be in the 40s Tuesday through Friday. && .AVIATION...(For the 06Z TAFs through 06Z Saturday Night) Issued at 1147 PM CDT FRI APR 25 2014 Low level wind shear will be a concern through the 12Z-14Z time period with surface winds around 10 mph from the south to southeast and winds around 1500 ft from the southwest near 45 kts. Still a signal for convection to be in the vicinity of TOP and FOE from 12Z to 16Z. South winds will increase by 16Z from the south around 18-20 kts with gusts to 28 kts. The winds will continue to stay gusty through the end of the period. TSRA may affect MHK after 02Z but confidence is not high enough to mention. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Gargan LONG TERM...63 AVIATION...53
AREA FORECAST DISCUSSION
NWS JACKSON KY
1032 PM EDT SUN APR 27 2014 .UPDATE... ISSUED AT 1030 PM EDT SUN APR 27 2014 AS EXPECTED...EARLIER THUNDERSTORMS HAVE WEAKENED WITH JUST SOME WIDELY ISOLATED SHOWERS PUSHING ACROSS THE AREA WITH THE WARM FRONT. THIS ACTIVITY WILL CONTINUE TO PUSH NORTHWARD OVER THE NEXT 3 TO 5 HOURS...WITH DRIER WEATHER RETURNING THROUGH THE LATTER HALF OF THE NIGHT. HOWEVER...PLENTY OF SHOWERS AND THUNDERSTORMS UPSTREAM ACROSS ARKANSAS AND FAR WESTERN KENTUCKY. SOME OF THIS MAY CONGEAL INTO AN MCS AND TRACK TOWARDS THE AREA TOMORROW MORNING. THIS COULD BRING THE THREAT OF DAMP WEATHER BACK TO THE AREA AROUND OR SHORTLY AFTER DAYBREAK. AT THIS TIME...IT DOES NOT APPEAR THIS ACTIVITY WILL POSE A SEVERE RISK AS SURFACE INSTABILITY WILL BE AT A MINIMUM EARLY IN THE MORNING. IT LOOKING MORE LIKE WE MAY HAVE MORE OF A SEVERE THREAT ARRIVING MONDAY EVENING OR MONDAY NIGHT AS WE MAY SEE AN MCS MOVE INTO THE AREA INTO THE OVERNIGHT TIME PERIOD. THUS...SEVERE THREAT APPEARS TO BE PUSHED BACK INTO MONDAY EVENING OR MONDAY NIGHT. UPDATE ISSUED AT 745 PM EDT SUN APR 27 2014 A FEW SHOWERS AND STORMS BEGINNING TO ENCROACH UPON EASTERN KENTUCKY. THE FIRST ONE IS JUST GRAZING THE WESTERN EDGE OF WAYNE COUNTY AS IT MOVES NORTHWARD...WITH A SECONDARY AREA MOVING INTO SOUTHERN BELL/WHITLEY COUNTIES. NOT MUCH OTHER ACTIVITY ON RADAR AT PRESENT TIME. WITH MORE OF A STRATIFORM LIGHT RAIN DEVELOPING FARTHER TO THE SOUTHWEST ACROSS NORTH CENTRAL TENNESSEE. STILL PLENTY OF DRY AIR IN PLACE ACROSS EASTERN KENTUCKY WHICH WILL LIKELY PUT THE END TO ANY STORM CHANCES AS STUFF TRIES TO PUSH INTO THE AREA. THUS...WITH SUN SETTING...WE WILL BE LOSING ANY INSTABILITY WE HAVE OUT THERE WITH THUNDERSTORMS DIMINISHING TOWARDS SHOWERS. EVEN THE SHOWERS WILL HAVE A TOUGH TIME SURVIVING AS THEY MOVE INTO THE DRIER AIR IN THE EAST. THUS...HAVE BACKED OFF POPS THIS EVENING INTO THE OVERNIGHT HOURS. ALSO BACKED OFF THUNDER CHANCES AFTER THE NEXT HOUR OR SO. NEXT ROUND OF SHOWERS AND THUNDERSTORMS REMAIN OUT ACROSS WESTERN TENNESSEE AND WESTERN KENTUCKY AND IF IT HOLDS TOGETHER...WOULD NOT BE INTO THE AREA UNTIL AFTER MIDNIGHT. UPDATED FORECAST IS ALREADY OUT. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 355 PM EDT SUN APR 27 2014 STARTING INTO AN ACTIVE PERIOD DURING THE SHORT TERM. A SURFACE LOW PRESSURE SYSTEM WILL REMAIN OVER THE CENTRAL PLAINS THIS EVENING...WHILE SEVERAL WAVES OF ENERGY WILL CONTINUE TO ROTATE AROUND THIS SYSTEM. EASTERN KY WILL REMAIN IN THE WARM SECTOR...WITH A WARM FRONT POSITIONED ACROSS MUCH OF THE STATE. MEANWHILE...WESTERN AND CENTRAL KY WILL FIND THEMSELVES POSITIONED BETWEEN THE WARM FRONT AND COLD FRONT...WITH WARM UNSTABLE AIR CONTINUING TO FILTER IN AND ABUNDANT MOISTURE TO ACCOMPANY. WHILE NOT MUCH PROGRESSION IS EXPECTED THIS AFTERNOON OR TONIGHT IN TERMS OF THE SURFACE LOW AND THE ASSOCIATED FRONTS...THE INCREASED INSTABILITY DURING THE AFTERNOON WILL WORK TO HELP ANY CONVECTIVE DEVELOPMENT TO SPREAD EASTWARD SLOWLY. LATEST HIRES MODELS...INCLUDING THE NAM12/HRRR/AND ECMWF ALL POINT AT PRECIP ENTERING INTO EASTERN KY BETWEEN 0 AND 6Z AND THEN CONTINUING EASTWARD THROUGHOUT THE NIGHT. IT IS ALSO AROUND THIS POINT THAT GFS40 AND NAM12 FORECAST SOUNDINGS SHOW SOME IMPRESSIVE LOW LEVEL SHEER IN PORTIONS OF EASTERN KY. WHILE LINGERING DRY LOW LEVEL AIR AND SE DOWNSLOPE WINDS COULD WORK TO HOLD OFF SOME PRECIP IN THE EVENING...EXPECT THAT ISOLATED TO SCATTERED SHOWERS WILL DEVELOP. IN DOING SO...MOISTENING OF THE LOW LEVELS WILL BE ENOUGH TO ALLOW UNSTABLE AIR TO RISE AND THUNDERSTORMS TO DEVELOP. IN ADDITION...BASED ON STRONG STORMS THAT HAVE DEVELOPED UPSTREAM...HAVE KEPT THUNDER AS THE PREDOMINATE WX TYPE THIS EVENING AND THROUGH THE NIGHT. BETWEEN 3Z AND 12Z MONDAY...CHANCE POPS WILL OVERSPREAD THE AREA. HOWEVER...LATEST HI-RES GUIDANCE IS POINTING AT A DRY POCKET DEVELOPING AS DOWNSLOPE FLOW INCREASES SLIGHTLY ACROSS THE SOUTHEAST PORTION OF THE STATE. LATEST RUC13 OMEGA IS ALSO SUPPORTIVE OF THIS IDEA...SHOWING DOWNWARD MOTION ACROSS THE SE PORTION OF THE STATE BY 9Z. THE QUESTION THEN WILL BE...HOW MUCH WILL THIS DOWNSLOPING INHIBIT ANY STORM DEVELOPMENT? HOW FAR INTO EASTERN KY COULD IT POTENTIALLY INHIBIT STORM GROWTH AND RAIN...AND WILL WE STILL EXPECT SOME ISOLATED TO SCATTERED CHANCES...OR WILL DOWNSLOPE CUT OFF POTENTIAL ALL TOGETHER? UNFORTUNATELY...THESE ARE ALL QUESTIONS WHICH CAN/T REALLY BE ANSWERED UNTIL THE MAIN CONVECTION REACHES OUR AREA. UNTIL THEN...WILL TRY TO PLAY ON THIS THINKING...AND TREND DOWN POPS SLIGHTLY FOR THE SE PORTION OF THE CWA. DURING THE DAY TOMORROW...SURFACE LOW WILL HAVE PROGRESSED ONLY SLIGHTLY EASTWARD...THOUGH THE SURFACE COLD FRONT WILL HAVE ENTERED INTO THE MISSISSIPPI VALLEY REGION. WITH THE FORCING SO GREAT IN PROXIMITY TO THIS FRONT...AND A STRONG PULL OF GULF MOISTURE...EXPECT SHOWERS/TSRA TO OVERCOME THE DOWNSLOPING PULL. ESPECIALLY IF WINDS SHIFT MORE SOUTHERLY FOR A PERIOD OF TIME...COULD SEE MORE WIDESPREAD DEVELOPMENT ACROSS THIS AREA. UNFORTUNATELY...EVEN THE HI-RES MODELS ARE SHOWING SOME DISAGREEMENT ON THE EXTENT AND MAGNITUDE OF PRECIP FOR TOMORROW...SO HAVE TRIED TO STICK TO A BLEND. Q VECTORS ARE SHOWING THE BEST AREAS FOR UPWARD MOTION AND STORM DEVELOPMENT REMAINING JUST TO OUR NORTH TOMORROW...MAINLY OVER THE UPPER GREAT LAKES REGION. SOME DECENT CONVERGENCE DOES MAKE IT INTO KY AS WELL...MOVING FROM WEST TO EAST ACROSS THE STATE. AS IT HEADS INTO EASTERN KY...EVEN THE QVECTOR CONVERGENCE PICKS UP ON A BRIEF LULL IN ACTIVITY ACROSS THE SE PORTION OF THE STATE WITH DOWNSLOPE WINDS IN PLACE. THIS QUICKLY DISAPPEARS AS THE BEST CONVERGENCE MOVES OVER THE REGION...SO FURTHER SUPPORT THAT AT SOME POINT THE MOISTURE WILL BE ENOUGH TO OVERCOME ANY EFFECTS FROM THE WIND DIRECTION. LOW LEVEL WIND SHEAR DURING THE DAY TOMORROW ISN/T QUITE AS IMPRESSIVE AS THAT EXPECTED THIS EVENING...BUT IT SEEMS TO BE A BIT DEEPER. WINDS IN THE UPPER LEVELS ARE QUITE STRONG...SO EXPECT A GOOD DRIVING FORCE AND THE POTENTIAL FOR A LINE OF SHOWERS/STORMS TO TRAVERSE KY /AS WAS REFLECTED IN THE MONDAY EVENING/MONDAY NIGHT POPS AND WEATHER/. MONDAY NIGHT/S LINE OF STORMS IS ALSO EXPECTED TO BRING THE BEST THREAT FOR HEAVY PRECIP DURING THE SHORT TERM ACCORDING TO THE LAST FEW MODEL RUNS. AFTER ROUND ONE OF PRECIP MOVES IN TONIGHT AND TOMORROW...A STRONGER SECOND LINE WILL DEVELOP CLOSER TO THE FRONT. MOISTURE GETTING PULLED IN WILL ALLOW FOR 6 HOUR QPF AMOUNTS WELL IN THE 1 TO 3 INCH RANGE BY 6Z TUESDAY...TRAVERSING EASTERN KY DURING THIS TIME. WITH THIS AMOUNT OF EXPECTED CONVECTIVE RAIN...AND THE CONTINUED POTENTIAL FOR SOME THUNDERSTORMS PRODUCING HEAVY SHOWERS OVER SMALL AREAS...THERE DOES LIE THE THREAT OF FLOODING ACROSS PORTIONS OF THE STATE...INCLUDING EASTERN KY. WINDS ALOFT ARE QUITE IMPRESSIVE AS THIS LINE MOVES OVER...SO ANY STORMS OR HEAVY RAIN SHOWERS BRING THE THREAT OF TRANSFERRING SOME OF THESE POTENTIALLY DAMAGING WINDS TO THE GROUND. AS FAR AS THE FLOODING...WILL PROBABLY NEED TO ISSUE A WATCH AT SOME POINT IN THE NEAR FUTURE. ELECTED NOT TO DURING THE DAY SHIFT JUST FOR THE SHEER FACT THAT THE MODELS ARE STILL HAVING A HARD TIME AGREEING...AND REALLY ITS GOING TO BE A MATTER OF HOW MUCH PRECIP WE END UP RECEIVING OVERNIGHT TONIGHT AND TOMORROW MORNING TO KNOW HOW SATURATED THE SOIL WILL BE LEADING INTO THE EVENING. WILL MENTION CONCERNS TO INCOMING SHIFT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 425 PM EDT SUN APR 27 2014 THE MODELS CONTINUE TO BE IN GOOD AGREEMENT ALOFT WITH THE LARGE AND LUMBERING CLOSED LOW OVER THE MID SECTION OF THE NATION AT THE START OF THE EXTENDED. THIS DOMINANT FEATURE ROLLS OVER ON ITSELF AS IT SLOWLY FILLS AND LIFTS NORTH INTO THE UPPER MIDWEST AND WESTERN GREAT LAKES BY 00Z THURSDAY. THE SYSTEM BECOMES MORE PROGRESSIVE TOWARD THE END OF THE WEEK...EVENTUALLY EXITING INTO EASTERN CANADA. BEFORE IT DOES SO...A CONTINUATION OF A SERIES OF MID LEVEL ENERGY PACKETS WILL PLOW THROUGH KENTUCKY BRINGING PERIODIC SUPPORT TO CONVECTION THROUGHOUT THE REGION. FOR TUESDAY...A KEY ONE OF THESE PACKETS MOVES OVER EAST KENTUCKY EARLY FOLLOWED BY ANOTHER LATE IN THE DAY AND INTO EARLY WEDNESDAY. THESE PACKETS DO WEAKEN WITH TIME SO THAT THE VERSION THAT GOES THROUGH ON MIDDAY WEDNESDAY WILL LIKELY NOT PACK THE PUNCH OF THE EARLIER ONES. FALLING HEIGHTS LOCALLY WILL BE NOTED INTO THURSDAY MORNING EVEN AS THE MAIN LOW TO THE NORTH WEAKENS BUT BY THIS TIME THE ENERGY SWIRLING PAST WILL BE SIMILARLY WEAKER. IT IS ALSO ABOUT THIS TIME THAT THE AGREEMENT OF THE GEM WITH THE NEARLY LOCKSTEP ECMWF AND GFS AT MID LEVELS FADES AND ITS SOLUTION IS SUBSEQUENTLY DISCOUNTED. THE OTHER MODELS CONTINUE TO MAINTAIN LOWER THAN NORMAL 500MB HEIGHTS OVER EAST KENTUCKY INTO THE WEEKEND DUE TO THE ARRIVAL OF ANOTHER...MORE PROGRESSIVE AND OPEN...TROUGH FROM THE PLAINS. THE GFS IS A BIT BETTER CONSOLIDATED WITH THIS THAN THE ECMWF AS IT TAKES ITS AXIS THROUGH EAST KENTUCKY EARLY SATURDAY WHILE THE ECMWF SNEAKS A LEAD WAVE THROUGH ON FRIDAY WITH THE REST OF THE SYSTEM PASSING THROUGH LATER SATURDAY. HEIGHTS WILL THEN TICK UP IN THE WAKE OF THIS ACTION TO CLOSE OUT THE WEEKEND ON A WELCOMED QUIETER NOTE. FOR THE FORECAST HAVE FOLLOWED A GENERAL MODEL BLEND THROUGH THE REST OF THE WORK WEEK WITH A SLIGHT PREFERENCE FOR THE LATEST ECMWF THEREAFTER. SENSIBLE WEATHER WILL FEATURE AT LEAST ONE LAST STORMY DAY AND NIGHT TO START THE EXTENDED. THE EXPECTATION IS THAT AN ONGOING CLUSTER OF STORMS WILL BE MOVING OUT OF EASTERN KENTUCKY AT 12Z TUESDAY. HOWEVER...THE NEXT SURGE OF LIFT ASSOCIATED WITH THE MID LEVEL WAVE ROLLING INTO THE AREA LATER THAT DAY WILL START TO ACT ON THE ENVIRONMENT OF EAST KENTUCKY DURING THE AFTERNOON. THIS WILL COMBINE WITH THE MOIST BOUNDARY LAYER...HEATING THROUGH THE DAY...TO GENERATE DECENT INSTABILITY LIKELY KICKING OFF ANOTHER CONVECTIVE CLUSTER. WITH THE VEERING SHEAR PROFILE AND POTENTIAL FOR HIGHER INSTABILITY BY EVENING TUESDAY...WILL CONTINUE THE THREAT OF STRONG TO SEVERE STORMS. THESE STORMS MAY LINGER INTO THE NIGHT BEFORE CLEARING OUT TO THE EAST ALONG WITH THE SYSTEM/S SLOW MOVING COLD FRONT FINALLY PUSHING OUT OF THE AREA. THE NEARBY FRONT AND LOW MID LEVEL HEIGHTS SHOULD LEAVE WEDNESDAY WITH A POTENTIAL FOR RENEWED CONVECTION...THOUGH THE THUNDER THREAT WILL PROBABLY BE LIMITED TO THE FAR EAST AND MAINLY EARLIER IN THE DAY. THE THREAT OF SHOWERS WILL THEN CONTINUE THROUGH THE REST OF THE WORK WEEK AND INTO THE FIRST PART OF THE WEEKEND WHILE LIMITED INSTABILITY AND COOLER TEMPERATURES KEEP THE THREAT OF THUNDER TO A MINIMUM. HAVE GONE WITH DRY WEATHER FOR SUNDAY AS HIGH PRESSURE SHOULD BE MOVING OVERHEAD. TEMPERATURES WILL BE DEFINITELY ON THE COOL SIDE OF NORMAL FOR THE BULK OF THE EXTENDED IN THE WAKE OF THE SYSTEM/S SLOW MOVING COLD FRONT PASSING THROUGH ON WEDNESDAY. TUESDAY REMAINS THE MOST CHALLENGING DAY FOR MAX TEMPERATURES DUE TO QUESTIONS OF CLEARING BEHIND THE DEPARTING EARLY MORNING BATCH OF CONVECTION. MORE...AND QUICKER...CLEARING WILL ALLOW TEMPERATURES TO SOAR INTO THE UPPER 70S AND ALSO SPIKE THE INSTABILITY MAKING FOR A BETTER POTENTIAL FOR SEVERE WEATHER. HOWEVER...THERE IS A POTENTIAL FOR CONVECTIVE DEBRIS AND LINGERING LOW CLOUDS/SHOWERS TO KEEP TEMPERATURES CAPPED AND INSTABILITY/SVR POTENTIAL MORE LIMITED. THE CR GRID LOAD CAME IN PRETTY GOOD FOR THE BULK OF THE EXTENDED... THOUGH DID MAKE SOME ADJUSTMENTS TOWARD THE LATEST ECMWF SOLUTION FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND...PARTICULARLY FOR A DRY SUNDAY. DID ALSO FINE TUNE SOME LOW TEMP GRIDS LATER IN THE FORECAST TO ALLOW FOR SOME ENHANCED RIDGE AND VALLEY DETAIL OVER THE WEEKEND. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 745 PM EDT SUN APR 27 2014 VFR CONDITIONS WILL START OFF THE EVENING AT THE TAF SITES. THESE VFR CONDITIONS MAY HOLD THROUGH THE NIGHT GIVEN THE DRY LOW LEVEL IN PLACE. IF WE CAN GET SOME BETTER SHOWER OR THUNDERSTORM ACTIVITY WE COULD MOISTEN UP THE LOW LEVELS PROVIDING A BRIEF WINDOW OF MVFR CIGS LATE TONIGHT. HOWEVER...AT THIS TIME...THIS LOOKS UNLIKELY. OVERALL...PRECIPITATION CHANCES LOOK FAIRLY SMALL TONIGHT GIVEN THE DRY LOW LEVELS. WE COULD SEE A SPRINKLE OR LIGHT RAIN SHOWER THROUGH THE NIGHT...BUT SHOULD NOT PROVIDE TOO MUCH OF AN AVIATION CONCERN. BETTER RAIN CHANCES WILL ARRIVE TOMORROW...BUT STILL UNCERTAINTY REGARDING THE POTENTIAL TIMING OF ANY RAIN. A BRIEF PERIOD OF LLWS MAY BE SEEN AT KSME AND KLOZ LATE TONIGHT BEFORE WE MIX OUT MONDAY MORNING. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...JMW LONG TERM...GREIF AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
745 PM EDT SUN APR 27 2014 .UPDATE... ISSUED AT 745 PM EDT SUN APR 27 2014 A FEW SHOWERS AND STORMS BEGINNING TO ENCROACH UPON EASTERN KENTUCKY. THE FIRST ONE IS JUST GRAZING THE WESTERN EDGE OF WAYNE COUNTY AS IT MOVES NORTHWARD...WITH A SECONDARY AREA MOVING INTO SOUTHERN BELL/WHITLEY COUNTIES. NOT MUCH OTHER ACTIVITY ON RADAR AT PRESENT TIME. WITH MORE OF A STRATIFORM LIGHT RAIN DEVELOPING FARTHER TO THE SOUTHWEST ACROSS NORTH CENTRAL TENNESSEE. STILL PLENTY OF DRY AIR IN PLACE ACROSS EASTERN KENTUCKY WHICH WILL LIKELY PUT THE END TO ANY STORM CHANCES AS STUFF TRIES TO PUSH INTO THE AREA. THUS...WITH SUN SETTING...WE WILL BE LOSING ANY INSTABILITY WE HAVE OUT THERE WITH THUNDERSTORMS DIMINISHING TOWARDS SHOWERS. EVEN THE SHOWERS WILL HAVE A TOUGH TIME SURVIVING AS THEY MOVE INTO THE DRIER AIR IN THE EAST. THUS...HAVE BACKED OFF POPS THIS EVENING INTO THE OVERNIGHT HOURS. ALSO BACKED OFF THUNDER CHANCES AFTER THE NEXT HOUR OR SO. NEXT ROUND OF SHOWERS AND THUNDERSTORMS REMAIN OUT ACROSS WESTERN TENNESSEE AND WESTERN KENTUCKY AND IF IT HOLDS TOGETHER...WOULD NOT BE INTO THE AREA UNTIL AFTER MIDNIGHT. UPDATED FORECAST IS ALREADY OUT. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 355 PM EDT SUN APR 27 2014 STARTING INTO AN ACTIVE PERIOD DURING THE SHORT TERM. A SURFACE LOW PRESSURE SYSTEM WILL REMAIN OVER THE CENTRAL PLAINS THIS EVENING...WHILE SEVERAL WAVES OF ENERGY WILL CONTINUE TO ROTATE AROUND THIS SYSTEM. EASTERN KY WILL REMAIN IN THE WARM SECTOR...WITH A WARM FRONT POSITIONED ACROSS MUCH OF THE STATE. MEANWHILE...WESTERN AND CENTRAL KY WILL FIND THEMSELVES POSITIONED BETWEEN THE WARM FRONT AND COLD FRONT...WITH WARM UNSTABLE AIR CONTINUING TO FILTER IN AND ABUNDANT MOISTURE TO ACCOMPANY. WHILE NOT MUCH PROGRESSION IS EXPECTED THIS AFTERNOON OR TONIGHT IN TERMS OF THE SURFACE LOW AND THE ASSOCIATED FRONTS...THE INCREASED INSTABILITY DURING THE AFTERNOON WILL WORK TO HELP ANY CONVECTIVE DEVELOPMENT TO SPREAD EASTWARD SLOWLY. LATEST HIRES MODELS...INCLUDING THE NAM12/HRRR/AND ECMWF ALL POINT AT PRECIP ENTERING INTO EASTERN KY BETWEEN 0 AND 6Z AND THEN CONTINUING EASTWARD THROUGHOUT THE NIGHT. IT IS ALSO AROUND THIS POINT THAT GFS40 AND NAM12 FORECAST SOUNDINGS SHOW SOME IMPRESSIVE LOW LEVEL SHEER IN PORTIONS OF EASTERN KY. WHILE LINGERING DRY LOW LEVEL AIR AND SE DOWNSLOPE WINDS COULD WORK TO HOLD OFF SOME PRECIP IN THE EVENING...EXPECT THAT ISOLATED TO SCATTERED SHOWERS WILL DEVELOP. IN DOING SO...MOISTENING OF THE LOW LEVELS WILL BE ENOUGH TO ALLOW UNSTABLE AIR TO RISE AND THUNDERSTORMS TO DEVELOP. IN ADDITION...BASED ON STRONG STORMS THAT HAVE DEVELOPED UPSTREAM...HAVE KEPT THUNDER AS THE PREDOMINATE WX TYPE THIS EVENING AND THROUGH THE NIGHT. BETWEEN 3Z AND 12Z MONDAY...CHANCE POPS WILL OVERSPREAD THE AREA. HOWEVER...LATEST HI-RES GUIDANCE IS POINTING AT A DRY POCKET DEVELOPING AS DOWNSLOPE FLOW INCREASES SLIGHTLY ACROSS THE SOUTHEAST PORTION OF THE STATE. LATEST RUC13 OMEGA IS ALSO SUPPORTIVE OF THIS IDEA...SHOWING DOWNWARD MOTION ACROSS THE SE PORTION OF THE STATE BY 9Z. THE QUESTION THEN WILL BE...HOW MUCH WILL THIS DOWNSLOPING INHIBIT ANY STORM DEVELOPMENT? HOW FAR INTO EASTERN KY COULD IT POTENTIALLY INHIBIT STORM GROWTH AND RAIN...AND WILL WE STILL EXPECT SOME ISOLATED TO SCATTERED CHANCES...OR WILL DOWNSLOPE CUT OFF POTENTIAL ALL TOGETHER? UNFORTUNATELY...THESE ARE ALL QUESTIONS WHICH CAN/T REALLY BE ANSWERED UNTIL THE MAIN CONVECTION REACHES OUR AREA. UNTIL THEN...WILL TRY TO PLAY ON THIS THINKING...AND TREND DOWN POPS SLIGHTLY FOR THE SE PORTION OF THE CWA. DURING THE DAY TOMORROW...SURFACE LOW WILL HAVE PROGRESSED ONLY SLIGHTLY EASTWARD...THOUGH THE SURFACE COLD FRONT WILL HAVE ENTERED INTO THE MISSISSIPPI VALLEY REGION. WITH THE FORCING SO GREAT IN PROXIMITY TO THIS FRONT...AND A STRONG PULL OF GULF MOISTURE...EXPECT SHOWERS/TSRA TO OVERCOME THE DOWNSLOPING PULL. ESPECIALLY IF WINDS SHIFT MORE SOUTHERLY FOR A PERIOD OF TIME...COULD SEE MORE WIDESPREAD DEVELOPMENT ACROSS THIS AREA. UNFORTUNATELY...EVEN THE HI-RES MODELS ARE SHOWING SOME DISAGREEMENT ON THE EXTENT AND MAGNITUDE OF PRECIP FOR TOMORROW...SO HAVE TRIED TO STICK TO A BLEND. Q VECTORS ARE SHOWING THE BEST AREAS FOR UPWARD MOTION AND STORM DEVELOPMENT REMAINING JUST TO OUR NORTH TOMORROW...MAINLY OVER THE UPPER GREAT LAKES REGION. SOME DECENT CONVERGENCE DOES MAKE IT INTO KY AS WELL...MOVING FROM WEST TO EAST ACROSS THE STATE. AS IT HEADS INTO EASTERN KY...EVEN THE QVECTOR CONVERGENCE PICKS UP ON A BRIEF LULL IN ACTIVITY ACROSS THE SE PORTION OF THE STATE WITH DOWNSLOPE WINDS IN PLACE. THIS QUICKLY DISAPPEARS AS THE BEST CONVERGENCE MOVES OVER THE REGION...SO FURTHER SUPPORT THAT AT SOME POINT THE MOISTURE WILL BE ENOUGH TO OVERCOME ANY EFFECTS FROM THE WIND DIRECTION. LOW LEVEL WIND SHEAR DURING THE DAY TOMORROW ISN/T QUITE AS IMPRESSIVE AS THAT EXPECTED THIS EVENING...BUT IT SEEMS TO BE A BIT DEEPER. WINDS IN THE UPPER LEVELS ARE QUITE STRONG...SO EXPECT A GOOD DRIVING FORCE AND THE POTENTIAL FOR A LINE OF SHOWERS/STORMS TO TRAVERSE KY /AS WAS REFLECTED IN THE MONDAY EVENING/MONDAY NIGHT POPS AND WEATHER/. MONDAY NIGHT/S LINE OF STORMS IS ALSO EXPECTED TO BRING THE BEST THREAT FOR HEAVY PRECIP DURING THE SHORT TERM ACCORDING TO THE LAST FEW MODEL RUNS. AFTER ROUND ONE OF PRECIP MOVES IN TONIGHT AND TOMORROW...A STRONGER SECOND LINE WILL DEVELOP CLOSER TO THE FRONT. MOISTURE GETTING PULLED IN WILL ALLOW FOR 6 HOUR QPF AMOUNTS WELL IN THE 1 TO 3 INCH RANGE BY 6Z TUESDAY...TRAVERSING EASTERN KY DURING THIS TIME. WITH THIS AMOUNT OF EXPECTED CONVECTIVE RAIN...AND THE CONTINUED POTENTIAL FOR SOME THUNDERSTORMS PRODUCING HEAVY SHOWERS OVER SMALL AREAS...THERE DOES LIE THE THREAT OF FLOODING ACROSS PORTIONS OF THE STATE...INCLUDING EASTERN KY. WINDS ALOFT ARE QUITE IMPRESSIVE AS THIS LINE MOVES OVER...SO ANY STORMS OR HEAVY RAIN SHOWERS BRING THE THREAT OF TRANSFERRING SOME OF THESE POTENTIALLY DAMAGING WINDS TO THE GROUND. AS FAR AS THE FLOODING...WILL PROBABLY NEED TO ISSUE A WATCH AT SOME POINT IN THE NEAR FUTURE. ELECTED NOT TO DURING THE DAY SHIFT JUST FOR THE SHEER FACT THAT THE MODELS ARE STILL HAVING A HARD TIME AGREEING...AND REALLY ITS GOING TO BE A MATTER OF HOW MUCH PRECIP WE END UP RECEIVING OVERNIGHT TONIGHT AND TOMORROW MORNING TO KNOW HOW SATURATED THE SOIL WILL BE LEADING INTO THE EVENING. WILL MENTION CONCERNS TO INCOMING SHIFT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 425 PM EDT SUN APR 27 2014 THE MODELS CONTINUE TO BE IN GOOD AGREEMENT ALOFT WITH THE LARGE AND LUMBERING CLOSED LOW OVER THE MID SECTION OF THE NATION AT THE START OF THE EXTENDED. THIS DOMINANT FEATURE ROLLS OVER ON ITSELF AS IT SLOWLY FILLS AND LIFTS NORTH INTO THE UPPER MIDWEST AND WESTERN GREAT LAKES BY 00Z THURSDAY. THE SYSTEM BECOMES MORE PROGRESSIVE TOWARD THE END OF THE WEEK...EVENTUALLY EXITING INTO EASTERN CANADA. BEFORE IT DOES SO...A CONTINUATION OF A SERIES OF MID LEVEL ENERGY PACKETS WILL PLOW THROUGH KENTUCKY BRINGING PERIODIC SUPPORT TO CONVECTION THROUGHOUT THE REGION. FOR TUESDAY...A KEY ONE OF THESE PACKETS MOVES OVER EAST KENTUCKY EARLY FOLLOWED BY ANOTHER LATE IN THE DAY AND INTO EARLY WEDNESDAY. THESE PACKETS DO WEAKEN WITH TIME SO THAT THE VERSION THAT GOES THROUGH ON MIDDAY WEDNESDAY WILL LIKELY NOT PACK THE PUNCH OF THE EARLIER ONES. FALLING HEIGHTS LOCALLY WILL BE NOTED INTO THURSDAY MORNING EVEN AS THE MAIN LOW TO THE NORTH WEAKENS BUT BY THIS TIME THE ENERGY SWIRLING PAST WILL BE SIMILARLY WEAKER. IT IS ALSO ABOUT THIS TIME THAT THE AGREEMENT OF THE GEM WITH THE NEARLY LOCKSTEP ECMWF AND GFS AT MID LEVELS FADES AND ITS SOLUTION IS SUBSEQUENTLY DISCOUNTED. THE OTHER MODELS CONTINUE TO MAINTAIN LOWER THAN NORMAL 500MB HEIGHTS OVER EAST KENTUCKY INTO THE WEEKEND DUE TO THE ARRIVAL OF ANOTHER...MORE PROGRESSIVE AND OPEN...TROUGH FROM THE PLAINS. THE GFS IS A BIT BETTER CONSOLIDATED WITH THIS THAN THE ECMWF AS IT TAKES ITS AXIS THROUGH EAST KENTUCKY EARLY SATURDAY WHILE THE ECMWF SNEAKS A LEAD WAVE THROUGH ON FRIDAY WITH THE REST OF THE SYSTEM PASSING THROUGH LATER SATURDAY. HEIGHTS WILL THEN TICK UP IN THE WAKE OF THIS ACTION TO CLOSE OUT THE WEEKEND ON A WELCOMED QUIETER NOTE. FOR THE FORECAST HAVE FOLLOWED A GENERAL MODEL BLEND THROUGH THE REST OF THE WORK WEEK WITH A SLIGHT PREFERENCE FOR THE LATEST ECMWF THEREAFTER. SENSIBLE WEATHER WILL FEATURE AT LEAST ONE LAST STORMY DAY AND NIGHT TO START THE EXTENDED. THE EXPECTATION IS THAT AN ONGOING CLUSTER OF STORMS WILL BE MOVING OUT OF EASTERN KENTUCKY AT 12Z TUESDAY. HOWEVER...THE NEXT SURGE OF LIFT ASSOCIATED WITH THE MID LEVEL WAVE ROLLING INTO THE AREA LATER THAT DAY WILL START TO ACT ON THE ENVIRONMENT OF EAST KENTUCKY DURING THE AFTERNOON. THIS WILL COMBINE WITH THE MOIST BOUNDARY LAYER...HEATING THROUGH THE DAY...TO GENERATE DECENT INSTABILITY LIKELY KICKING OFF ANOTHER CONVECTIVE CLUSTER. WITH THE VEERING SHEAR PROFILE AND POTENTIAL FOR HIGHER INSTABILITY BY EVENING TUESDAY...WILL CONTINUE THE THREAT OF STRONG TO SEVERE STORMS. THESE STORMS MAY LINGER INTO THE NIGHT BEFORE CLEARING OUT TO THE EAST ALONG WITH THE SYSTEM/S SLOW MOVING COLD FRONT FINALLY PUSHING OUT OF THE AREA. THE NEARBY FRONT AND LOW MID LEVEL HEIGHTS SHOULD LEAVE WEDNESDAY WITH A POTENTIAL FOR RENEWED CONVECTION...THOUGH THE THUNDER THREAT WILL PROBABLY BE LIMITED TO THE FAR EAST AND MAINLY EARLIER IN THE DAY. THE THREAT OF SHOWERS WILL THEN CONTINUE THROUGH THE REST OF THE WORK WEEK AND INTO THE FIRST PART OF THE WEEKEND WHILE LIMITED INSTABILITY AND COOLER TEMPERATURES KEEP THE THREAT OF THUNDER TO A MINIMUM. HAVE GONE WITH DRY WEATHER FOR SUNDAY AS HIGH PRESSURE SHOULD BE MOVING OVERHEAD. TEMPERATURES WILL BE DEFINITELY ON THE COOL SIDE OF NORMAL FOR THE BULK OF THE EXTENDED IN THE WAKE OF THE SYSTEM/S SLOW MOVING COLD FRONT PASSING THROUGH ON WEDNESDAY. TUESDAY REMAINS THE MOST CHALLENGING DAY FOR MAX TEMPERATURES DUE TO QUESTIONS OF CLEARING BEHIND THE DEPARTING EARLY MORNING BATCH OF CONVECTION. MORE...AND QUICKER...CLEARING WILL ALLOW TEMPERATURES TO SOAR INTO THE UPPER 70S AND ALSO SPIKE THE INSTABILITY MAKING FOR A BETTER POTENTIAL FOR SEVERE WEATHER. HOWEVER...THERE IS A POTENTIAL FOR CONVECTIVE DEBRIS AND LINGERING LOW CLOUDS/SHOWERS TO KEEP TEMPERATURES CAPPED AND INSTABILITY/SVR POTENTIAL MORE LIMITED. THE CR GRID LOAD CAME IN PRETTY GOOD FOR THE BULK OF THE EXTENDED... THOUGH DID MAKE SOME ADJUSTMENTS TOWARD THE LATEST ECMWF SOLUTION FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND...PARTICULARLY FOR A DRY SUNDAY. DID ALSO FINE TUNE SOME LOW TEMP GRIDS LATER IN THE FORECAST TO ALLOW FOR SOME ENHANCED RIDGE AND VALLEY DETAIL OVER THE WEEKEND. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 745 PM EDT SUN APR 27 2014 VFR CONDITIONS WILL START OFF THE EVENING AT THE TAF SITES. THESE VFR CONDITIONS MAY HOLD THROUGH THE NIGHT GIVEN THE DRY LOW LEVEL IN PLACE. IF WE CAN GET SOME BETTER SHOWER OR THUNDERSTORM ACTIVITY WE COULD MOISTEN UP THE LOW LEVELS PROVIDING A BRIEF WINDOW OF MVFR CIGS LATE TONIGHT. HOWEVER...AT THIS TIME...THIS LOOKS UNLIKELY. OVERALL...PRECIPITATION CHANCES LOOK FAIRLY SMALL TONIGHT GIVEN THE DRY LOW LEVELS. WE COULD SEE A SPRINKLE OR LIGHT RAIN SHOWER THROUGH THE NIGHT...BUT SHOULD NOT PROVIDE TOO MUCH OF AN AVIATION CONCERN. BETTER RAIN CHANCES WILL ARRIVE TOMORROW...BUT STILL UNCERTAINTY REGARDING THE POTENTIAL TIMING OF ANY RAIN. A BRIEF PERIOD OF LLWS MAY BE SEEN AT KSME AND KLOZ LATE TONIGHT BEFORE WE MIX OUT MONDAY MORNING. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...JMW LONG TERM...GREIF AVIATION...KAS
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
943 PM CDT SUN APR 27 2014 .DISCUSSION... UPDATED THE AREAL DISTRIBUTION OF POPS TO MORE CLOSELY FOLLOW THE HRR (HIGH RESOLUTION RAPID REFRESH) SOLUTION. OTHERWISE...THE ZONE PACKAGE IS ON TARGET. JT && .PREV DISCUSSION... /ISSUED 630 PM CDT SUN APR 27 2014/ DISCUSSION... FOR 00Z TAFS...VFR TO MVFR CONDITIONS EXPECTED THIS EVENING...WITH GUSTY SOUTH WINDS. NOT EXPECTING THE NEXT ROUND OF PRECIP UNTIL TOWARDS DAYBREAK...BUT LOW CONFIDENCE ON COVERAGE AT THIS POINT. PREV DISCUSSION... /ISSUED 436 PM CDT SUN APR 27 2014/ DISCUSSION... LATEST WATER VAPOR SATELLITE IMAGERY SHOWED A VIGOROUS UPPER LOW OVER NW KS/SW NE...WITH A VIGOROUS PACIFIC JET NOSING IN FROM THE PAC NW AND CURLING CYCLONICALLY THROUGH THE BASE OF THE LOW. A SUBTROPICAL JET WAS NOTED TO THE SOUTH ACROSS CENTRAL MX INTO THE WRN GULF. KLCH AND KPOE VWPS CONTINUE TO SHOW A 50KT PLUS SOUTHWESTERLY LLJ. AT THE SFC...LOW PRESSURE IS HARD TO MISS OVER NW KS...WITH A TRAILING CDFNT/DRYLINE THROUGH CENTRAL OK/TX. HARD TO HAVE A GREAT DEAL OF FAITH IN ANY SPECIFIC SHORT TERM GUIDANCE...AS PRECIOUS FEW CAUGHT THE ISOLATED TO SCATTERED ELEVATED CONVECTION THAT DEVELOPED THIS AFTERNOON. THE ONLINE SPC 4KM WRF WASNT TOO BAD...AND THE HRRR DID FINALLY CATCH ON. THESE TWO MODELS...WITH SOME ADDITIONAL SUPPORT FROM GLOBAL MODELS...DEPICT A BAND OF CONVECTION INITIATING AFTER MIDNIGHT IN THE VICINITY OF EAST CENTRAL TEXAS NE TWD SHREVEPORT. THE SOUTHWESTWARD EXTENT OF ANY SUCH DEVELOPMENT IS A BIT UNCERTAIN...BUT IT IS NOT OUT OF THE QUESTION FOR NORTHERN ZONES TO BE AFFECTED GIVEN THE THE PROJECTED EAST/NORTHEAST MOVEMENT. WILL MAINTAIN HIGHEST POPS TONIGHT IN THIS AREA...AND HOLD ONTO THE SEVERE WORDING. GENERALLY PRESERVED THE INHERITED INLAND WIND HAZARDS...BUT DID TWEAK THE MARINE HAZARDS A BIT...EASING OUT OF THE SCA FOR THE COASTAL LAKES AND BAYS MID EVENING...AND THE INLAND WATERS WEST OF CAMERON AFTER MIDNIGHT CONCURRENT WITH LATEST PROGS THAT SHOW WINDS STARTING TO DECREASE FROM WEST TO EAST OVERNIGHT AND INTO TOMORROW. A WIND ADVISORY MAY STILL BE WARRANTED FOR A TIME ACROSS SOUTH/EAST CENTRAL LOUISIANA...BUT WILL LET THE OVERNIGHT CREW MAKE THE CALL ON THAT AS IT LOOKS A LITTLE MORE MARGINAL. CONVECTIVE PROSPECTS WILL ALSO SHIFT EAST TOMORROW...AS THE CDFNT PUSHES JUST EAST OF A KSHV TO KLFK LINE BY TOMORROW AFTERNOON. HAVE GENERALLY LEFT THIS PART OF THE FORECAST AS IS...STAYING MAINLY WITH LOW TO MID RANGE POPS AND PRESERVING THE SEVERE WORDING PER SPC DAY 2 CONVECTIVE OUTLOOK. THE FRONT IS STILL FCST TO PUSH THROUGH THE DURING THE AFTERNOON AND EVENING HOURS ON TUE...WITH THE SEVERE RISK DISPLACED TO OUR EAST BY THIS TIME. ALTHOUGH STILL NOT IN IDEAL AGREEMENT...THE GFS HAS COME A LONG WAY TOWARD THE ECMWF SOLUTION IN DEPICTING SOUTHWESTERLY FLOW ALOFT...WITH ONE OR MORE FRONTAL WAVES/LOWS DEVELOPING ALONG THE FRONT. APPEARS THAT THE BEST CHANCE OF ANY RAIN AFFECTING THE AREA WOULD BE THU NIGHT-FRI...AS BOTH MODELS DEPICTING A SHORTWAVE TROF PIVOTING THROUGH THE NW GULF COAST REGION. MARINE... GUSTY SOUTH WINDS AND ROUGH SEAS WILL CONTINUE THIS EVENING AS A LOW PRESSURE SYSTEM DEVELOPS IN THE PLAINS. WINDS WILL BEGIN TO DIMINISH A BIT OVER THE COASTAL LAKES AND BAYS TONIGHT AND THE WATERS WEST OF CAMERON LATE TONIGHT INTO TOMORROW. TIDES WILL BE RUNNING ABOUT ONE FOOT ABOVE NORMAL TODAY AND MONDAY. THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL ALSO CONTINUE INTO EARLY NEXT WEEK AS THIS LOW PRESSURE SYSTEM SLOWLY MOVES EAST THROUGH THE CENTRAL UNTIED STATES...CULMINATING IN A FRONT CROSSING THE REGION TUESDAY NIGHT. OFFSHORE FLOW WILL PREVAIL IN THE WAKE OF THE FRONT FOR THE REST OF THE WORK WEEK. && .PRELIMINARY POINT TEMPS/POPS... KLCH 72 84 70 85 57 / 20 30 20 20 20 KBPT 72 84 69 85 58 / 20 20 20 20 10 KAEX 71 85 67 83 53 / 50 50 30 30 10 KLFT 72 84 71 85 58 / 30 40 40 30 30 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: ACADIA...CALCASIEU...EAST CAMERON...IBERIA... JEFFERSON DAVIS...LAFAYETTE...LOWER ST. MARTIN...ST. MARY... UPPER ST. MARTIN...VERMILION...WEST CAMERON. TX...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: JEFFERSON...ORANGE. GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM...WATERS FROM INTRACOASTAL CITY TO CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON LA TO HIGH ISLAND TX FROM 20 TO 60 NM...WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM. SMALL CRAFT EXERCISE CAUTION UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: CALCASIEU LAKE...SABINE LAKE. SMALL CRAFT EXERCISE CAUTION UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING ZONES: VERMILION BAY. SMALL CRAFT ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM. SMALL CRAFT EXERCISE CAUTION UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM. && FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.LAKECHARLES.GOV WWW.TWITTER.COM/NWSLAKECHARLES WWW.YOUTUBE.COM/NWSLAKECHARLES && $$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
630 PM CDT SUN APR 27 2014 .DISCUSSION... FOR 00Z TAFS...VFR TO MVFR CONDITIONS EXPECTED THIS EVENING...WITH GUSTY SOUTH WINDS. NOT EXPECTING THE NEXT ROUND OF PRECIP UNTIL TOWARDS DAYBREAK...BUT LOW CONFIDENCE ON COVERAGE AT THIS POINT. && .PREV DISCUSSION... /ISSUED 436 PM CDT SUN APR 27 2014/ DISCUSSION... LATEST WATER VAPOR SATELLITE IMAGERY SHOWED A VIGOROUS UPPER LOW OVER NW KS/SW NE...WITH A VIGOROUS PACIFIC JET NOSING IN FROM THE PAC NW AND CURLING CYCLONICALLY THROUGH THE BASE OF THE LOW. A SUBTROPICAL JET WAS NOTED TO THE SOUTH ACROSS CENTRAL MX INTO THE WRN GULF. KLCH AND KPOE VWPS CONTINUE TO SHOW A 50KT PLUS SOUTHWESTERLY LLJ. AT THE SFC...LOW PRESSURE IS HARD TO MISS OVER NW KS...WITH A TRAILING CDFNT/DRYLINE THROUGH CENTRAL OK/TX. HARD TO HAVE A GREAT DEAL OF FAITH IN ANY SPECIFIC SHORT TERM GUIDANCE...AS PRECIOUS FEW CAUGHT THE ISOLATED TO SCATTERED ELEVATED CONVECTION THAT DEVELOPED THIS AFTERNOON. THE ONLINE SPC 4KM WRF WASNT TOO BAD...AND THE HRRR DID FINALLY CATCH ON. THESE TWO MODELS...WITH SOME ADDITIONAL SUPPORT FROM GLOBAL MODELS...DEPICT A BAND OF CONVECTION INITIATING AFTER MIDNIGHT IN THE VICINITY OF EAST CENTRAL TEXAS NE TWD SHREVEPORT. THE SOUTHWESTWARD EXTENT OF ANY SUCH DEVELOPMENT IS A BIT UNCERTAIN...BUT IT IS NOT OUT OF THE QUESTION FOR NORTHERN ZONES TO BE AFFECTED GIVEN THE THE PROJECTED EAST/NORTHEAST MOVEMENT. WILL MAINTAIN HIGHEST POPS TONIGHT IN THIS AREA...AND HOLD ONTO THE SEVERE WORDING. GENERALLY PRESERVED THE INHERITED INLAND WIND HAZARDS...BUT DID TWEAK THE MARINE HAZARDS A BIT...EASING OUT OF THE SCA FOR THE COASTAL LAKES AND BAYS MID EVENING...AND THE INLAND WATERS WEST OF CAMERON AFTER MIDNIGHT CONCURRENT WITH LATEST PROGS THAT SHOW WINDS STARTING TO DECREASE FROM WEST TO EAST OVERNIGHT AND INTO TOMORROW. A WIND ADVISORY MAY STILL BE WARRANTED FOR A TIME ACROSS SOUTH/EAST CENTRAL LOUISIANA...BUT WILL LET THE OVERNIGHT CREW MAKE THE CALL ON THAT AS IT LOOKS A LITTLE MORE MARGINAL. CONVECTIVE PROSPECTS WILL ALSO SHIFT EAST TOMORROW...AS THE CDFNT PUSHES JUST EAST OF A KSHV TO KLFK LINE BY TOMORROW AFTERNOON. HAVE GENERALLY LEFT THIS PART OF THE FORECAST AS IS...STAYING MAINLY WITH LOW TO MID RANGE POPS AND PRESERVING THE SEVERE WORDING PER SPC DAY 2 CONVECTIVE OUTLOOK. THE FRONT IS STILL FCST TO PUSH THROUGH THE DURING THE AFTERNOON AND EVENING HOURS ON TUE...WITH THE SEVERE RISK DISPLACED TO OUR EAST BY THIS TIME. ALTHOUGH STILL NOT IN IDEAL AGREEMENT...THE GFS HAS COME A LONG WAY TOWARD THE ECMWF SOLUTION IN DEPICTING SOUTHWESTERLY FLOW ALOFT...WITH ONE OR MORE FRONTAL WAVES/LOWS DEVELOPING ALONG THE FRONT. APPEARS THAT THE BEST CHANCE OF ANY RAIN AFFECTING THE AREA WOULD BE THU NIGHT-FRI...AS BOTH MODELS DEPICTING A SHORTWAVE TROF PIVOTING THROUGH THE NW GULF COAST REGION. MARINE... GUSTY SOUTH WINDS AND ROUGH SEAS WILL CONTINUE THIS EVENING AS A LOW PRESSURE SYSTEM DEVELOPS IN THE PLAINS. WINDS WILL BEGIN TO DIMINISH A BIT OVER THE COASTAL LAKES AND BAYS TONIGHT AND THE WATERS WEST OF CAMERON LATE TONIGHT INTO TOMORROW. TIDES WILL BE RUNNING ABOUT ONE FOOT ABOVE NORMAL TODAY AND MONDAY. THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL ALSO CONTINUE INTO EARLY NEXT WEEK AS THIS LOW PRESSURE SYSTEM SLOWLY MOVES EAST THROUGH THE CENTRAL UNTIED STATES...CULMINATING IN A FRONT CROSSING THE REGION TUESDAY NIGHT. OFFSHORE FLOW WILL PREVAIL IN THE WAKE OF THE FRONT FOR THE REST OF THE WORK WEEK. && .PRELIMINARY POINT TEMPS/POPS... KLCH 72 84 70 85 57 / 20 30 20 20 20 KBPT 72 84 69 85 58 / 20 20 20 20 10 KAEX 71 85 67 83 53 / 50 50 30 30 10 KLFT 72 84 71 85 58 / 30 40 40 30 30 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: ACADIA...CALCASIEU...EAST CAMERON...IBERIA... JEFFERSON DAVIS...LAFAYETTE...LOWER ST. MARTIN...ST. MARY... UPPER ST. MARTIN...VERMILION...WEST CAMERON. WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: ALLEN...AVOYELLES...BEAUREGARD...EVANGELINE... RAPIDES...ST. LANDRY...VERNON. TX...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: JEFFERSON...ORANGE. WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: HARDIN...NORTHERN JASPER...NORTHERN NEWTON... SOUTHERN JASPER...SOUTHERN NEWTON...TYLER. GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM...WATERS FROM INTRACOASTAL CITY TO CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON LA TO HIGH ISLAND TX FROM 20 TO 60 NM...WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: CALCASIEU LAKE...SABINE LAKE...VERMILION BAY. SMALL CRAFT EXERCISE CAUTION UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: CALCASIEU LAKE...SABINE LAKE. SMALL CRAFT EXERCISE CAUTION THROUGH MONDAY MORNING FOR THE FOLLOWING ZONES: VERMILION BAY. SMALL CRAFT ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM. SMALL CRAFT EXERCISE CAUTION FROM MIDNIGHT CDT TONIGHT THROUGH MONDAY MORNING FOR THE FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM. && FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.LAKECHARLES.GOV WWW.TWITTER.COM/NWSLAKECHARLES WWW.YOUTUBE.COM/NWSLAKECHARLES && $$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
930 PM EDT SUN APR 27 2014 .SYNOPSIS... LOW PRESSURE SOUTH OF NOVA SCOTIA WILL CONTINUE MOVING INTO THE OPEN ATLANTIC TONIGHT INTO MONDAY. HIGH PRESSURE WILL BUILD SOUTH ACROSS THE REGION MONDAY NIGHT THROUGH WEDNESDAY. && .NEAR TERM /THROUGH MONDAY/... 930 PM UPDATE...MOISTURE CONTINUES TO PUSH TO THE WEST/SOUTHWEST ACROSS THE CWA ASSOCIATED WITH AN AREA OF LOW PRES EAST OF NOVA SCOTIA. SCATTERED SHOWERS MAINLY ACROSS THE NORTHEAST CORNER OF THE CWA AS OF 9 PM. THE SHOWERS HAVE BEEN LIGHT WITH RAINFALL AMOUNTS OF A TRACE TO A COUPLE HUNDREDTHS OF AN INCH IN ANY THE SPOTS THAT HAVE PICKED UP A SHOWER OVER PAST FEW HOURS. THE 00Z KCAR RAOB WAS BELOW 0C ABOVE 925 MILLIBARS...AND WITH A BIT OF LOW LEVEL COOLING OVERNIGHT THE SHOWERS COULD MIX WITH OR CHANGE TO SNOW SHOWERS LATE TONIGHT ACROSS NORTHERN MAINE AND OVER THE WESTERN MOUNTAINS AS THE SHOWERS CONTINUE TO PUSH OFF TO THE WEST. LITTLE/NO SNOW ACCUMULATION IS EXPECTED. ONLY MINOR CHANGES TO THE ONGOING FORECAST BASED ON THE LATEST OBSERVATIONS...RADAR TRENDS...AND NEAR TERM MODELS. PREVIOUS DISCUSSION... THE CHALLENGE WILL DEFINITELY BE THE TEMPERATURES AND WHERE TO PLACE RAINFALL CHANCES. LOW PRES WAS SPINNING SE OF NOVA SCOTIA PER THE 18Z ANALYSIS. SFC TROUGH EXTENDING OFF THIS LOW EXTENDED BACK EASTERN AND CENTRAL MAINE. THE FIRST BATCH OF LIGHT RAIN/SHOWERS MOVED SSW EARLY TODAY AND ANOTHER ROUND IS APPROACHING FROM NEW BRUNSWICK. THE RAIN HAS BEEN WEAKENING AS IT RUNS INTO DRIER AIR AS SEEN BY THE LATEST SATELLITE VISIBLE IMAGERY SHOWING BREAKS IN THE CLOUDS. BEST SUPPORT FOR SUBSTANTIAL RAIN HAS BEEN OVER THE EASTERN SECTIONS OF WASHINGTON COUNTY. DECENT LLVL CONVERGENCE AND MID LEVEL FORCING IS THERE AS SEEN BY BOTH THE RAP AND NAM12. EXPECTING THIS TREND TO CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON. CARRIED CHANCE POPS(30-50%) FOR THE CWA TONIGHT W/THE HIGHEST CHANCES ACROSS NORTHERN AND EASTERN SECTIONS. AS ONE TRAVELS FURTHER W AND SW, SHOWERS WILL WEAKEN DUE TO SUBSIDENCE IN PLACE. CLOUDS WILL HANG AROUND THROUGHOUT THE NIGHT AND THIS WILL KEEP TEMPERATURES WELL ABOVE 32F WHICH SHOULD ALLOW FOR ALL LIQUID PRECIP. RAINFALL AMOUNTS HAVE BEEN LIGHT AND SEE NO SUPPORT FOR THIS TO CHANGE MUCH OVER THE NEXT 24 HRS. THEREFORE, STAYED W/QPF OF 0.10" OR LESS THROUGH MONDAY. CONDITIONS LOOK TO IMPROVE THROUGHOUT THE DAY ON MONDAY AS HIGH PRES IS FORECAST TO WEDGE DOWN FROM CANADA. SOME SUNSHINE IS EXPECTED BY MONDAY AFTERNOON ESPECIALLY ACROSS THE NORTHERN AND EASTERN SECTIONS WHILE THE CENTRAL HIGHLANDS WILL HANG ON TO MORE CLOUDS. THIS WILL LEAD TO A VARIATION IN TEMPERATURES. DECIDED TO BOOST DAYTIME HIGHS ON MONDAY UP TO READINGS AOA 50F MAINLY FOR THE NORTHERN AND EASTERN SECTIONS. CENTRAL AND WESTERN AREAS WILL HANG W/MORE CLOUDS THUS KEEPING TEMPERATURES DOWN INTO THE 40S SOMEWHAT SIMILAR TO TODAY. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE WILL RIDGE SOUTH ACROSS THE REGION MONDAY NIGHT THROUGH EARLY WEDNESDAY...THEN BEGIN TO MOVE EAST LATER WEDNESDAY. CLOUD COVER WILL DECREASE ACROSS THE REGION MONDAY NIGHT. MOSTLY CLEAR SKIES WILL OCCUR ACROSS THE REGION TUESDAY INTO EARLY WEDNESDAY. CLOUD COVER WILL THEN BEGIN TO INCREASE LATER WEDNESDAY...PARTICULARLY ACROSS WESTERN PORTIONS OF THE FORECAST AREA. TEMPERATURES WILL BE AT NEAR NORMAL...TO SLIGHTLY BELOW NORMAL...LEVELS TUESDAY/WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AN UNSETTLED PATTERN WILL TAKE HOLD ONCE AGAIN FOR THE LONG RANGE AS THE RIDGE BREAKS DOWN AND THE NEXT UPPER LEVEL LOW ADVANCES TOWARD THE REGION. CLOUDS WILL INCREASE WEDNESDAY NIGHT WITH RAIN AND SHOWERS DEVELOPING WEST TO EAST FOR THURSDAY AS AN OCCLUSION MOVES THROUGH AHEAD OF A SURFACE LOW ADVANCING NORTH ALONG THE COAST. STEADIER RAIN LOOKS TO TAPER OFF THURSDAY NIGHT WITH RAIN AMOUNTS OF A HALF INCH TO AN INCH POSSIBLE BY THIS TIME. EXPECT SHOWERS TO LINGER INTO FRIDAY IN ASSOCIATION WITH THE BROAD UPPER LEVEL LOW SITUATED OVER THE GREAT LAKES BY THIS TIME AND A LINGERING SURFACE TROUGH. SOME UNCERTAINTY DEVELOPS IN THE FORECAST FOR THE BEGINNING OF NEXT WEEKEND. OVERALL, THE UNSETTLED PATTERN REMAINS HOWEVER THE ECMWF MODEL BRINGS A BRIEF WINDOW OF SOME PARTIAL CLEARING AND DRYING IN FOR SATURDAY WHILE THE GFS SUGGESTS MORE CLOUDS WITH AT LEAST A FEW LINGERING SHOWERS. AT THIS POINT WILL KEEP IN THE CHANCE OF SHOWERS WITH MOSTLY CLOUDY SKIES. A BETTER CHANCE FOR MORE WIDESPREAD RAIN AND SHOWERS DEVELOPS ONCE AGAIN FOR SATURDAY NIGHT AND SUNDAY AS THE NEXT SURFACE WAVE ASSOCIATED WITH THE BROAD UPPER TROUGH DEVELOPS SOUTH OF THE REGION AND MOVES NORTH UP THE COAST. TEMPERATURES THROUGH THE LONG RANGE ARE FORECAST TO REMAIN WITHIN A FEW DEGREES OF AVERAGE FOR THIS TIME OF YEAR. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... NEAR TERM: VFR AT ALL THE TERMINALS AS OF 01Z. EXPECTATION IS FOR CIGS TO DROP TO MVFR ACROSS ALL THE TERMINALS OVERNIGHT. A PERIOD OF IFR IS POSSIBLE LATE TONIGHT(AFT 08Z) AND THIS WILL MAINLY BE FOR THE NORTHERN TERMINALS. DECIDED TO STAY W/MVFR THROUGH MIDDAY MONDAY. AN IMPROVEMENT TO VFR IS EXPECTED BY MON EVENING. SHORT TERM: VFR CONDITIONS ARE EXPECTED ACROSS THE REGION MONDAY NIGHT THROUGH WEDNESDAY. VFR WEDNESDAY NIGHT WILL GIVE WAY TO MVFR AND THEN IFR THURSDAY AS RAIN MOVES IN FROM WEST TO EAST. MVFR/IFR CONDITIONS ARE LIKELY TO PERSIST INTO FRIDAY DUE TO LOW STRATUS WITH LINGERING SHOWERS. && .MARINE... NEAR TERM: NO SCA ATTM. LATEST MODEL GUIDANCE HAS BEEN RUNNING TOO HIGH FOR THE WINDS AND ADJUSTMENTS WERE MADE TO PUSH THE SPEEDS BACK. THE WIND WILL GRADUALLY INCREASE OVER THE NEXT 24 HOURS AND THE SEAS WILL SLOWLY BUILD. A SCA MAY BE NEEDED BY LATE MONDAY. SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE ON THE WATERS MONDAY NIGHT INTO EARLY TUESDAY NIGHT. CONDITIONS ARE EXPECTED TO BE BELOW SMALL CRAFT ADVISORY LEVELS LATER TUESDAY NIGHT INTO WEDNESDAY. SCA CONDITIONS WILL BE POSSIBLE THURSDAY AS SE WINDS STRENGTHEN AND WAVE HEIGHTS INCREASE AHEAD OF AN OCCLUSION MOVING THROUGH WHICH WILL ALSO BRING RAIN AND THE POTENTIAL FOR FOG. THESE CONDITIONS IMPROVE FOR FRIDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...CB/HEWITT SHORT TERM...NORCROSS LONG TERM...FITZSIMMONS AVIATION...CB/HEWITT/NORCROSS MARINE...CB/HEWITT/NORCROSS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1238 PM EDT SAT APR 26 2014 .SYNOPSIS... MOISTURE STARVED COLD FRONT CROSSES TODAY...WITH AN ISOLATED SHOWER OR THUNDERSTORM POSSIBLE SOUTH OF THE MASON DIXON LINE. SUNDAY SHOULD BE DRY BEFORE AN UNSETTLED PATTERN SETS UP FOR THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... COLD FRONT IS SLOWLY SAGGING TOWARDS THE FORECAST AREA EARLY THIS AFTERNOON. JUST AHEAD OF IT...STRONG MIXING WITH THE TIGHTENING PRESSURE GRADIENT HAS HAS ALLOWED FOR A SURGE IN TEMPERATURES. HAVE UPPED HIGH TEMPERATURES FOR AREAS SOUTH OF THE FRONT THROUGH THE AFTERNOON BUT CLOUDS MAY BE A LIMITING FACTOR FOR THE COUNTIES SOUTH OF THE MASON-DIXON LINE. GUSTY WINDS WILL CONTINUE INTO THE EVENING AS THE COLD FRONT CROSSES THE REGION. IN ADDITION...ANOTHER ROUND OF SHOWERS AND AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT WHERE MOISTURE REMAINS SOUTH OF I-70. WILL CONTINUE TO CARRY POPS THERE AS THE HRRR SUGGESTS REDEVELOPMENT THIS AFTERNOON. CLEARING SKIES AND LIGHT WINDS SHOULD ALLOW FOR TEMPERATURES TO FALL BELOW SEASONAL NORMALS OVERNIGHT. SOME MID-HIGH CLOUDS MAY LINGER OVER OUR FAR SOUTHERN ZONES WHERE THE COLD FRONT STALLS TONIGHT...BEFORE IT LIFTS AS A WARM FRONT TOMORROW. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... SUNDAY IS CURRENTLY THE ONLY DAY IN THE 7 DAY FORECAST WITHOUT A CHANCE OF RAIN IN THE FORECAST THANKS TO HIGH PRESSURE BRIEFLY PASSING OVER THE REGION. LOW PRESSURE WILL BEGIN TO DEVELOP IN THE PLAINS...AND THE ASSOCIATED WARM FRONT WILL SWEEP TOWARDS THE REGION ON MONDAY. RAIN IS EXPECTED TO WORK ITS WAY INTO EASTERN OHIO ON MONDAY...AND ACROSS THE ENTIRE FORECAST AREA MONDAY NIGHT. DAYTIME HIGHS WILL BE NEAR NORMAL...WITH OVERNIGHT LOWS ABOVE NORMAL AS CLOUDS MOVE IN. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... MODELS IN AGREEMENT ON A BROAD AREA OF LOW PRESSURE LINGERING OVER THE ERN CONUS CENTERED IN THE GREAT LAKES THROUGH THE END OF NEXT WEEK. THIS WILL PROVIDE DAILY CHANCES OF RAIN SHOWERS AND WORK TO MODERATE TEMPERATURES UNDER CLOUDY SKIES. WITH A BLOCKED PATTERN ALOFT DOUBT UPPER LEVEL SYSTEM WILL BE QUICK TO MOVE OFF FOR THE WEEKEND...WITH COOL TEMPERATURES AND SHOWER CHANCES CONTINUED FOR SATURDAY. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... VFR THROUGH THE TAF PERIOD AS A MOISTURE STARVED FRONT WORKS ACROSS REGION THIS AFTERNOON. WINDS WILL BE GUSTY TO 25 KTS FROM THE WEST TURNING NORTHWEST 18-22Z WITH MAIN FROPA. WINDS WILL DIMINISH TOWARD SUNSET WITH VFR AND LIGHT NORTHERLY FLOW THROUGH SUNDAY. .OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/... PERIODIC RSTRNS ARE EXPD MUCH OF NXT WK AS A SERIES OF DISTURBANCES CROSS THE RGN. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1133 AM EDT SAT APR 26 2014 .SYNOPSIS... SCATTERED SHOWERS ARE EXPECTED TODAY...WITH AN ISOLATED THUNDERSTORM POSSIBLE SOUTH OF THE MASON DIXON LINE. SUNDAY SHOULD BE DRY BEFORE AN UNSETTLED PATTERN SETS UP FOR THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... SHOWERS ASSOCIATED WITH A WEAK SHORTWAVE CONTINUE TO SLIDE ACROSS THE REGION THIS MORNING. THE HRRR SEEMED TO HANDLE THE RESOLUTION OF THESE SHOWERS WELL...SO POPS WERE ADJUSTED THROUGH THE AFTERNOON TO REFLECT THIS FORECAST. EXPECT THE GREATEST COVERAGE TO REMAIN SOUTH OF I-70 FOR THE REST OF THE DAY AS A COLD FRONT SINKS SOUTHWARD FROM LAKE ERIE. BUFKIT SOUNDINGS SUGGEST THAT THERE COULD BE ENOUGH INSTABILITY WITH HEATING TO SUPPORT A THUNDERSTORM OR TWO WITH THE LIFT FROM THE COLD FRONT SO MAINTAINED THE ISOLATED THUNDER MENTION. EXPECT GUSTY WINDS WITH THE FRONTAL PASSAGE THIS AFTERNOON...WEAKENING AFTER SUNSET. TEMPERATURES WILL BE SEASONABLE DURING THE DAY...BUT BELOW NORMAL TONIGHT WITH LIGHT WINDS AND CLEARING SKIES. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... SUNDAY IS CURRENTLY THE ONLY DAY IN THE 7 DAY FORECAST WITHOUT A CHANCE OF RAIN IN THE FORECAST THANKS TO HIGH PRESSURE BRIEFLY PASSING OVER THE REGION. LOW PRESSURE WILL BEGIN TO DEVELOP IN THE PLAINS...AND THE ASSOCIATED WARM FRONT WILL SWEEP TOWARDS THE REGION ON MONDAY. RAIN IS EXPECTED TO WORK ITS WAY INTO EASTERN OHIO ON MONDAY...AND ACROSS THE ENTIRE FORECAST AREA MONDAY NIGHT. DAYTIME HIGHS WILL BE NEAR NORMAL...WITH OVERNIGHT LOWS ABOVE NORMAL AS CLOUDS MOVE IN. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MODELS IN AGREEMENT ON A BROAD AREA OF LOW PRESSURE LINGERING OVER THE ERN CONUS CENTERED IN THE GREAT LAKES THROUGH THE END OF NEXT WEEK. THIS WILL PROVIDE DAILY CHANCES OF RAIN SHOWERS AND WORK TO MODERATE TEMPERATURES UNDER CLOUDY SKIES. WITH A BLOCKED PATTERN ALOFT DOUBT UPPER LEVEL SYSTEM WILL BE QUICK TO MOVE OFF FOR THE WEEKEND...WITH COOL TEMPERATURES AND SHOWER CHANCES CONTINUED FOR SATURDAY. && .AVIATION /16Z SATURDAY THROUGH THURSDAY/... VFR THROUGH THE TAF PERIOD AS A MOISTURE STARVED FRONT WORKS ACROSS REGION THIS AFTERNOON. WINDS WILL BE GUSTY TO 25 KTS FROM THE WEST TURNING NORTHWEST 18-22Z WITH MAIN FROPA. WINDS WILL DIMINISH TOWARD SUNSET WITH VFR AND LIGHT NORTHERLY FLOW THROUGH SUNDAY. .OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/... PERIODIC RSTRNS ARE EXPD MUCH OF NXT WK AS A SERIES OF DISTURBANCES CROSS THE RGN. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS BALTIMORE MD/WASHINGTON DC
1008 AM EDT SAT APR 26 2014 .SYNOPSIS... ANOTHER COLD FRONT WILL PASS THROUGH THE AREA LATER TODAY BEFORE HIGH PRESSURE RETURNS SUNDAY. LOW PRESSURE WILL DEVELOP OVER THE CENTRAL UNITED STATES EARLY NEXT WEEK. THIS WILL LIKELY BRING CLOUDY...RAINY...AND COOL CONDITIONS TO THE REGION. && .NEAR TERM /THROUGH SUNDAY/... PART ONE OF THE UPPER LEVEL LOW PRES SYSTEM MOVED THROUGH YESTERDAY...W/ A BIGGER BUILD-UP TO A LARGER SECTION OF PRECIP ALONG W/ THE MAIN SYNOPTIC SYSTEM. PART TWO TODAY WILL BE THE BACK-END LESSER POTENT PASSAGE OF A MINOR SHORTWAVE. THIS FEATURE WILL ALSO DEVELOP A SFC LOW PRES SYSTEM...BUT VERY WEAK AND SMALL IN SCALE. THE SFC LOW WILL BE SWINGING CLOSER TO THE NYC METRO AREA...DRAGGING THE WEAK SFC COLD FRONT ACROSS OUR PORTION OF THE MID ATLC REGION...BACK INTO THE CNTRL APLCNS. THE TAILEND OF THIS FEATURE IS ALREADY KICKING-OFF SOME SCATTERED SHOWERS OVER CNTRL/ERN OH AND SOME BANKING INTO THE WINDWARD SIDE OF THE APLCNS. PLENTY OF WIND UPSTAIRS BUT IT`S NOT BEING MIXED DOWN QUITE YET. RELATIVELY LOW DEWPOINTS WILL ALLOW TEMPS TO QUICKLY SHOOT BACK UP INTO THE 50S/60S THRU THE REST OF THE MRNG HRS. BY THE MID-LATE AFTN...WE`LL SEE WIDESPREAD 70S AND A FEW U70S OVER THE SRN TIER OF THE CWA/LOWER VA PIEDMONT. ONCE WLY WINDS START TO PICK UP LATER THIS MRNG/EARLY AFTN...THE STRONGER WINDS WILL THE DOWNSLOPING AND THEREFORE THE WARMING PROCESS - AND BRING TEMPS UP A FEW MORE DEG THAN THE SYNOPTIC ALLOWANCE. PLENTY OF DRY AIR OVERHEAD...W/ SOME OF THE BOUNDARY LAYER EXPECTED TO CLOSE THAT GAP HEADING INTO THE AFTN HRS BUT STILL THE ENVIRONMENT LENDS TO LOCALIZED DOWNBURSTS OF A PORTION OF THE LL 50-70KT JET. THE AMBIENT WINDS THIS AFTN DURING THE PEAK HEATING HRS WILL BE GUSTY...WELL INTO THE 20-30MPH RANGE W/ A FEW GUSTS NEAR 40MPH. THE MAIN CONCERN WILL BE W/ THE FAST-MOVING SHOWER...THAT COULD HELP PULL DOWN LOCALLY STRONGER GUSTS. THESE SHOWERS DON`T EVEN NEED TO BE TSTMS...JUST WEAKLY CONVECTIVELY INDUCED TO TAP INTO THE MID/BOUNDARY LAYER WINDS. PRECIP ACTIVITY FOR THE AREA WILL BE RELATIVELY BRIEF IN TERMS OF THE ENTIRE DAY AND ISOLATED. A COUPLE OF WAVES OF ISOLATED TO SCATTERED SHOWERS WILL LIKELY SWING THRU THE CWA ALONG A NW-SE TREK...SOME LOCAL MODELS LIKE THE RECENT WRF AND HRRR RUNS BRINGING AT LEAST ONE WAVE OVER DC AND BALT REGIONS LATER THIS AFTN. PREV DISC... THE WAVE WILL EXIT THE AREA THIS EVENING AND HIGH PRESSURE WILL REBUILD SATURDAY NIGHT AND SUNDAY. A CHILLY NIGHT SATURDAY NIGHT IN THE 40/S IS EXPECTED...AND HIGH TEMPERATURES SUNDAY WILL BE A BIT BELOW NORMAL IN THE 60/S. SUNDAY WILL BE DRY. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... SFC RDG AXIS WL BE ATOP CWFA SUN NGT...WHILE THE UPR RDG SHUD BE POSITIONED ACRS THE GRTLKS/OHVLY/SRN APLCNS. THEREFORE...FAIR WX SHUD PREVAIL...BUT THERE WL STILL BE ITEMS TO ADDRESS. MOST NOTABLY WL BE THE INCRS IN CLDS IN ASSOC W/ H8 WAA. AM KEEPING MIN-T A BIT ABV THE MOS MEAN AS A RSLT. THE WMFNT CROSSES CWFA MON...PROVIDING MDT-STRONG ISENT LIFT. GDNC SUGGESTING THERE WL BE A 30-40 KT LLJ PRESENT...BUT ARE AT ODDS ON EXACTLY WHERE TO PLACE IT. REGARDLESS...THINK THERE WL BE ENUF UVV TO SUPPORT DVLPG RA...AND AM FEATURING AN UPTICK IN POPS NOT JUST DURING THE DAY...BUT ALSO MON NGT. ONCE AGN...GDNC TIMING WM FROPA A BIT DIFFERENTLY...WHICH WL AFFECT THE TIME FRAME WHEN THE MOST SGFNT RAFL WL OCCUR. EITHER WAY...MON WL MARK THE START OF A WET PD. && .LONG TERM /TUESDAY THROUGH FRIDAY/... THE MIDDLE OF THE WEEK WILL BE RATHER SOGGY AND COOL. LOW PRESSURE OVER THE GREAT PLAINS WILL APPROACH THE AREA FOR THE MIDDLE OF NEXT WEEK. OVERCAST CONDITIONS SHOULD PERSIST THROUGHOUT THE DAY ON TUES IN MOIST ONSHORE LOW LEVEL FLOW. WEAK COLD AIR DAMMING COULD ALSO OCCUR...HELPING TO KEEP HIGH TEMPS IN THE MID 50S FOR MOST OF THE AREA...ABOUT 15 DEG BELOW NORMAL FOR THIS TIME OF YEAR. A WARM FRONT WILL CROSS THE AREA FROM SOUTH TO NORTH BEGINNING TUESDAY AFTERNOON. THIS WARM FRONT WILL INITIALLY OVERRUN COOLER AIR AT THE SURFACE AND SHOULD BRING SHOWERS TO THE AREA THROUGHOUT THE DAY TUES. SHOWERS REMAIN LIKELY THROUGH THE DAY ON WEDNESDAY AS A SERIES OF WEAK DISTURBANCES PASS OVER THE AREA AND WARM MOIST AIR CONTINUES TO FILL IN ON THE BACK OF SOUTHEASTERLY FLOW IN THE LOWER LEVELS. THE LOW WILL STALL OVER THE GREAT LAKES WED NIGHT AND THURS AND THE ASSOCIATED COLD FRONT WILL BEGIN TO APPROACH THE AREA WED EVENING. GUIDANCE IS CURRENTLY SHOWING WEAK TO MODERATE INSTABILITY FOCUSED OVER THE SOUTHERN PORTION OF THE CWA AHEAD OF THE FRONT WEDNESDAY NIGHT AND TUES MORNING...THUS HAVE PUT ISOLATED THUNDERSTORMS ALONG WITH LIKELY RAIN SHOWERS IN THE FORECAST FOR THIS TIME PERIOD GENERALLY SOUTH OF A LINE FROM PENDLETON CO WV TO CALVERT CO MD. HIGH PRESSURE WILL BEGIN TO FILL BACK INTO THE AREA BEHIND THE COLD FRONT OVERNIGHT THURS AND FRI SHOULD ALLOW FOR US TO START DRYING OUT UNDER MOSTLY SUNNY SKIES AND TEMPS NEAR 70. && .AVIATION /13Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS THRU THE TAF PERIOD. THE MAIN CONCERNS FROM THE GUSTY SFC WINDS FROM LATE THIS MRNG INTO EARLY AFTN. WDLY SCT -SHRA SPREADING FROM HGR TO IAD/DCA/BWI AFTER 18Z. TS POSSIBLE CB TOPS FL380 SFC WIND G30KT 21Z- 00Z. VFR AFTER 00Z SUNDAY. RA OVERSPREADING TERMINALS MON. VFR SHUD HOLD UP FOR THE MRNG PUSH...THEN FLGT CAT DROPPING THRU MVFR. SUSPECT IFR WONT ARRIVE TIL AFDK. IFR CONDITIONS ARE LIKELY IN LOW CEILINGS AND RAIN SHOWERS AS A WARM FRONT SLOWLY CROSSES THE AREA TUESDAY AND INTO WEDNESDAY. && .MARINE... STRONG MIXING WITHIN THE NEXT COUPLE HRS WILL ALLOW FOR GUSTS TO CONTINUE INTO THE 20-25 MPH RANGE. SMALL CRAFT ADVISORIES WILL CONTINUE INTO THE AFTERNOON. A GALE WARNING MAY BE WARRANTED IN THE AFTERNOON AS CONVECTIVE SHOWERS MAY PRODUCE SMALL HAIL AND STRONG WIND GUSTS. SCA HAS BEEN EXTENDED INTO SAT NGT AS HIGH PRES BUILDS INTO THE AREA. SUN LOOKS TO HAVE LESS WIND. RDG AXIS SHUD PROVIDE WNDS AOB 10 KT THRU MON. DIRECTION MAINLY NE VEERING SE AS A WMFNT CROSSES THE WATERS. WNDS CUD BE CLSR TO 15 KT MON NGT MID BAY/LWR PTMC...BUT MOMENTUM TRANSFER LOOKS QUITE POOR. A SMALL CRAFT ADVISORY MAY BE NECESSARY FOR THE LOWER MARYLAND CHESAPEAKE BAY IN SOUTHERLY FLOW TUESDAY NIGHT. && .TIDES/COASTAL FLOODING... ADVY FOR ANNAPOLIS EXPIRED...AND WATER BACK W/IN BANKS. LOOKS LIKE STRONGER WINDS REACHED BALT AS XPCTD BASED ON FLATLINING OF HYDROGRAPH. DC PEAKING JUST UNDER ADVY CRITERIA. NW FLOW SHUD ASSIST IN RETURNING WATER LVLS TO NORMAL BY THE PM TIDE CYCLE. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ530>543. && $$ UPDATE...GMS PREV DISCUSSION...SDG/HTS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
936 AM EDT SAT APR 26 2014 .SYNOPSIS... SCATTERED SHOWERS ARE EXPECTED TODAY...WITH AN ISOLATED THUNDERSTORM POSSIBLE SOUTH OF THE MASON DIXON LINE. SUNDAY SHOULD BE DRY BEFORE AN UNSETTLED PATTERN SETS UP FOR THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... SHOWERS ASSOCIATED WITH A WEAK SHORTWAVE CONTINUE TO SLIDE ACROSS THE REGION THIS MORNING. THE HRRR SEEMED TO HANDLE THE RESOLUTION OF THESE SHOWERS WELL...SO POPS WERE ADJUSTED THROUGH THE AFTERNOON TO REFLECT THIS FORECAST. EXPECT THE GREATEST COVERAGE TO REMAIN SOUTH OF I-70 FOR THE REST OF THE DAY AS A COLD FRONT SINKS SOUTHWARD FROM LAKE ERIE. BUFKIT SOUNDINGS SUGGEST THAT THERE COULD BE ENOUGH INSTABILITY WITH HEATING TO SUPPORT A THUNDERSTORM OR TWO WITH THE LIFT FROM THE COLD FRONT SO MAINTAINED THE ISOLATED THUNDER MENTION. EXPECT GUSTY WINDS WITH THE FRONTAL PASSAGE THIS AFTERNOON...WEAKENING AFTER SUNSET. TEMPERATURES WILL BE SEASONABLE DURING THE DAY...BUT BELOW NORMAL TONIGHT WITH LIGHT WINDS AND CLEARING SKIES. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... SUNDAY IS CURRENTLY THE ONLY DAY IN THE 7 DAY FORECAST WITHOUT A CHANCE OF RAIN IN THE FORECAST THANKS TO HIGH PRESSURE BRIEFLY PASSING OVER THE REGION. LOW PRESSURE WILL BEGIN TO DEVELOP IN THE PLAINS...AND THE ASSOCIATED WARM FRONT WILL SWEEP TOWARDS THE REGION ON MONDAY. RAIN IS EXPECTED TO WORK ITS WAY INTO EASTERN OHIO ON MONDAY...AND ACROSS THE ENTIRE FORECAST AREA MONDAY NIGHT. DAYTIME HIGHS WILL BE NEAR NORMAL...WITH OVERNIGHT LOWS ABOVE NORMAL AS CLOUDS MOVE IN. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... MODELS IN AGREEMENT ON A BROAD AREA OF LOW PRESSURE LINGERING OVER THE ERN CONUS CENTERED IN THE GREAT LAKES THROUGH THE END OF NEXT WEEK. THIS WILL PROVIDE DAILY CHANCES OF RAIN SHOWERS AND WORK TO MODERATE TEMPERATURES UNDER CLOUDY SKIES. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... MID-LEVEL CLOUDS CONTINUE TO STREAM IN AHEAD OF ANOTHER WEAK COLD FRONT TODAY. SPOTTY MVFR CONDITIONS FOR VISBY WILL QUICKLY GIVE WAY TO VFR AS CLOUDS INCREASE. INCLUSION OF MARGINAL LLVL WIND SHEAR AS 20-30KT SOUTHWEST WINDS EXIST ABOUT 2KFT OFF THE DECK. THE WEAK COLDFRONT TODAY WILL SPAWN MORE SCT SHOWERS AND MOSTLY VFR STRATOCU ON THIS AFTERNOON WITH GUSTY WINDS. .OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/... PERIODIC RSTRNS ARE EXPD ERLY NXT WK AS A SERIES OF DISTURBANCES CROSS THE RGN. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
715 PM EDT SUN APR 27 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 432 PM EDT SUN APR 27 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER LEVEL TROUGH THROUGH THE NW CONUS WITH A LOW OVER WRN KS AND A DOWNSTREAM RIDGE FROM THE SE CONUS THROUGH WRN LAKES INTO MANITOBA. AT THE SFC...A BRISK ERLY FLOW PREVAILED THROUGH THE NRN LAKES BETWEEN HIGH PRES OVER HUDSON BAY AND A DEEP LOW OVER NW KS. AN INITIAL BAND OF LIGHT PCPN WAS PRODUCING MAINLY JUST SPRINKLES INTO THE FAR WRN CWA NEAR IWD AS IT ENCOUNTERS THE VERY DRY LAYER BELOW 750 MB. HOWEVER...A MORE SUBSTANTIAL AREA OF RAIN OVER WRN INTO N CNTRL WI...SUPPORTED BY 300K ISENTROPIC LIFT WAS LIFTING TOWARD UPPER MI. TONIGHT...RADAR TRENDS AND SHORT TERM MODELS SUGGEST THAT SOME LIGHT SHOWERS WILL MOVE INTO THE WEST LATE THIS AFTERNOON AND EVENING. HOWEVER...THERE IS A LOWER CHANCE THAT THERE WILL BE MEASURABLE PCPN GIVEN THE AMOUNT OF DRY AIR TO OVERCOME WITH THE ERLY LOW LEVEL INFLOW. FARTHER TO THE EAST...OVER S CNTRL UPPER MI...THE DRY AIR...PER 12Z APX SOUNDING...SHOULD BE MORE EFFECTIVE AT SLOWING THE ADVANCE AND REDUCING PCPN CHANCES. WITH EVAPORATIVE COOLING AT THE LEADING EDGE OF THE PCPN...SOME SNOW OR SLEET MAY ALSO MIX IN WITH THE RAIN LATE THIS EVENING AND OVERNIGHT...PER NAM LOW LEVEL THICKNESS AND WET-BULB ZERO HEIGHTS. MON...THE MODELS WERE IN SLIGHTLY BETTER AGREEMENT IN HANDLING THE ADVANCE OF PCPN INTO UPPER MICHIGAN. THE NAM/GFS/ECMWF WERE NOW ON THE SLOWER SIDE COMPARED TO GEM. AS THE MID/UPPER LEVEL LOW SLOWLY WOBBLES TO THE NORTHEAST AND AN ELONGATED TROUGH/FRONT EXTENDS FROM SRN IA INTO NRN INDIANA. ANOTHER BAND OF RAIN WILL MOVE TOWARD UPPER MI WITH INCREASING 300K-305K ISENTROPIC ASCENT NORTH OF THE 850 MB WARM FRONT THROUGH CNTRL WI. THERE IS STILL LIKELY TO BE SHARP CUTOFF TO THE NRN EDGE OF THE PCPN BAND THROUGH CNTRL UPPER MI. THE HIGHEST CHANCES WILL REMAIN ALONG THE WI BORDER WITH ONLY A SLIGHT CHANCE OVER THE NORTH. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 432 PM EDT SUN APR 27 2014 UPPER LOW OVER THE CENTRAL PLAINS MONDAY AFTERNOON AND ASSOCIATED SFC LOW AND WARM FRONT WILL BE MAIN FOCUS FOR THE FORECAST THIS UPCOMING WEEK. MODELS VERY LOCKED INTO IDEA THAT WHILE WIDESPREAD SHRA AND TSRA AND SEVERE WEATHER IMPACT MID TO LOWER MISSISSIPPI RIVER VALLEY...ADDITIONAL SHRA/TSRA DEVELOP LATE MONDAY AFTN ALONG WARM FRONT EXTENDING TO THE EAST OF SFC LOW OVER NEB. THIS IS IN RESPONSE TO SHORTWAVE/PV ANAMOLY LIFTING AHEAD OF PARENT UPPER LOW. POSSIBLE THAT ADDITIONAL SHRA WILL ALREADY BE LIFTING TOWARD UPR MICHIGAN AS WELL DUE TO REMNANTS OF SHRA/TSRA DEVELOPING OVER THE UPPER MISSISSIPPI RIVER VALLEY MONDAY MORNING PER SSW-NNE ORIENTED FORWARD PROPAGATING CORFIDI VECTORS AND H85-H7 MOSITURE TRANSPORT. AREA OF SHRA/TSRA ALONG WARM FRONT WILL GLIDE TOWARD UPR MICHIGAN OVERNIGHT INTO TUESDAY MORNING DUE TO THE ARRIVAL OF SHORTWAVE AND H85-H5 Q-VECTOR CONVERGENCE ALONG WITH VEERING H85-H7 FLOW FM ESE TO MORE SSW. FOLLOWING THE Q-VECTOR CONVERGENCE AND RIBBON OF MOISTURE TRANSPORT...EXPECT MOST PRECIPITATION TO OCCUR IN THE MORNING. BASED ON 1000-850MB THICKNESSES/H85 TEMPS AND HEIGHT OF WBZERO...MAY SEE SNOW OR A RAIN/SNOW MIX OVER HIGHER TERRAIN OF WEST AND NCNTRL UPR MICHIGAN PERHAPS EVEN LINGERING INTO MID AFTN. MINOR SNOW ACCUMULATIONS SEEM POSSIBLE...ESPECIALLY ON GRASSY SURFACES. WILL LEAVE OUT OF HAZARDOUS WEATHER OUTLOOK FOR NOW AS TRAVEL WOULD PROBABLY BE ONLY MINIMALLY IMPACTED. BY LATE AFTN...EXPECT CHANGE OVER TO RAIN AS H85 TEMPS SURGE ABOVE ZERO. THIS MAY BE OCCURRING WHEN MAJORITY OF HEAVIER PRECIPITATION IS COMING TO AN END THOUGH. BY TUE EVENING...FORECAST SOUNDINGS SHOW DRYING ABOVE H9...SO THERE MAY BE DRIZZLE. TEMPS WILL CONTINUE TO RISE SFC-H85 SO BY THAT TIME WILL ONLY BE DEALING WITH LIQUID PRECIP. ON WEDNESDAY...PRIMARY SHORTWAVE LIFTS NORTH ACROSS THE UPPER GREAT LAKES. SEEMS TO BE A TREND FOR BEST MOISTURE TRANSPORT TO MISS UPR MICHIGAN TO THE EAST...ALLOWING BULK OF RAIN ON WEDNESDAY TO SURGE NORTH ACROSS THE LOWER LAKES. HOWEVER...SIGNAL THAT HIGHER THETA-E AT H8-H7 WILL BE WRAPPING WESTWARD ACROSS UPR MICHIGAN ON CYCLONIC NORTH SIDE OF FILLING SFC-H85 LOWS. RAIN ON WEDNESDAY WOULD ONLY BE BOLSTERED OVER HIGHER TERRAIN OF WESTERN AND NORTH CENTRAL UPPER MICHIGAN WITH NE BLYR WINDS. WEDNESDAY NIGHT INTO THURSDAY...THE VERTICALLY STACKED LOW PRESSURE SYSTEM REMAINS NEARLY STATIONARY OVER THE UPPER GREAT LAKES. UNSETTLED WEATHER PATTERN AND WILL KEEP WITH THE CHANCES THAT CONSENSUS OF MODELS SHOWS. THE GREATEST CHANCES OF RAIN WILL BE ALONG AND NORTH AND WEST OF H85 LOW WHERE HIGHER THETA-E CONTINUES TO WRAP AROUND THE LOW AND ALSO WHERE LINGERING Q-VECTOR CONVERGENCE IS LOCATED. YET...CANNOT RULE OUT PRECIP JUST ABOUT ANYWHERE OVER THE CWA AS OTHER SHORTWAVES WILL PROBABLY BE CYCLING AROUND THE MAIN UPPER LOW CENTER AND THERE SHOULD BE PLENTY OF LOW-MID LEVEL MOISTURE REMAINING OVER REGION. DO NOT EXPECT THE PRECIP THAT OCCURS BEYOND WEDNESDAY EVENING TO BE HEAVY AS RICHER MOISTURE WILL BE HEADING WELL TO THE EAST OF THE REGION BY THAT TIME. GRADUALLY COOLING TEMPERATURES ALOFT AND EVENTUALLY AT THE SFC /H85 TEMPS DROPPING BLO 0C PER GFS/ECMWF/ COULD RESULT IN MIXED RAIN AND SNOW OVER PORTIONS OF CWA LATER WEDNESDAY NIGHT INTO THURSDAY MORNING AND AGAIN THURSDAY NIGHT INTO FRIDAY MORNING. MAY EVEN SEE MIX LATER FRIDAY NIGHT INTO SATURDAY MORNING. ONLY SLIGHT CHANCES FOR POPS BY THAT TIME THOUGH AS SYSTEM WILL BE UNRAVELLING AS IT LIFTS EAST AND NORTH AWAY FM LK SUPERIOR/UPR MICHIGAN. UPPER LEVEL TROUGH STILL FORECAST OVER THE REGION NEXT WEEKEND...SO NO WARM UP IS IN STORE. COULD BE MORE RAIN/SNOW BY NEXT SUNDAY AS THERE ARE HINTS OF STRONGER SYSTEM WORKING THROUGH AT THAT TIME. HOWEVER...SINCE THE TIMING FOR THAT SYSTEM WILL BE COMPLETELY DICTATED BY THE UPPER LOW THIS WEEK AND HOW QUICK IT DEPARTS...THERE IS CONSIDERABLE UNCERTAINTY IN HOW ALL THESE DETAILS WILL EVENTUALLY WORK OUT. THUS...CHANGES TO MODEL CONSENSUS BEYEOND THURSDAY WERE MINIMAL GIVEN THE UNCERTAINTY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 715 PM EDT SUN APR 27 2014 VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. THERE COULD BE SOME INTERMITTENT LIGHT RAIN AT KIWD THIS EVENING AS MID LEVELS BEGIN TO MOISTEN...BUT CONDITIONS ARE EXPECTED TO REMAIN VFR. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 432 PM EDT SUN APR 27 2014 EAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE DEEPENS OVER THE PLAINS. EXPECT ENE GALES TO 35KTS OVER WESTERN LK SUPERIOR TOWARD DULUTH INTO TUE MORNING. EAST GALES ARE THEN EXPECTED LATE TONIGHT INTO MON OVER THE REST OF THE WESTERN LAKE. WINDS WILL GRADUALLY DIMINISH TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE. WINDS ARE EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED INTO THU AS THE LOW FILLS AND REMAINS NEAR UPPER MICHIGAN. && .HYDROLOGY... ISSUED AT 432 PM EDT SUN APR 27 2014 RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS...AND THE STURGEON RIVER NEAR NAHMA JUNCTION IN DELTA COUNTY. AT LEAST THROUGH MONDAY NONE OF THESE RIVERS ARE EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS MAY START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY LATE THIS WEEK. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK...ESPECIALLY OVER THE NORTHWEST HALF OF UPPER MICHIGAN WHERE SNOWMELT WILL ALSO ADD TO THE RUNOFF. REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE. WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. HOWEVER...THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 11 AM EDT /10 AM CDT/ TUESDAY FOR LSZ162. GALE WARNING FROM 2 AM TO 8 PM EDT MONDAY FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...07 MARINE...JLB HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
422 PM EDT SAT APR 26 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 417 PM EDT SAT APR 26 2014 WV IMAGERY AND RUC ANALYSIS INDICATED CONFLUENT MID/UPPER LEVEL FLOW THROUGH THE NRN LAKES BETWEEN A TROUGH INTO THE NE CONUS AND A RIDGE FROM THE MID MS VALLEY INTO THE NRN PLAINS SASK. AT THE SFC...A RIDGE EXTENDED FROM HUDSON BAY INTO THE WRN GREAT LAKES RESULTING IN N TO NE FLOW INTO UPPER MICHIGAN. VIS LOOP SHOWED A CLEARING TREND WITH THE COMBINATION OF DRY ADVECTION AND DAYTIME MIXING HELPING TO SCOUR OUT THE LOW CLOUDS. AFTERNOON TEMPS RANGED FROM THE MID 30S NORTH...DOWNWIND OF LAKE SUPERIOR...TO THE MID 40S OVER THE SOUTH. TONIGHT...EVEN THOUGH THERE MAY BE SOME INCREASE IN HIGH CLOUDS OVERNIGHT AND SOME LIGHT EAST WINDS...EXPECT RADIATIONAL COOLING CONDITIONS WILL BE FAVORABLE ENOUGH TO ALLOW TEMPS TO DROP TOWARD THE LOWER 20S INLAND NORTH AND TO AROUND 30 NEAR THE WI BORDER. SUN...AS THE STRONG MID LEVEL AND SFC LOW MOVE INTO THE CNTRL PLAINS WAA PCPN AHEAD OF THE 850 MB WARM FRONT MAY APPROACH UPPER MI AS IT SPREADS THROUGH WI. HOWEVER...WITH PERSISTENT ERLY LOW LEVEL DRY ADVECTION AND THE VERY DRY PROFILE BELOW 750 MB...PER FCST SOUNDINGS...EXPECT THAT THE PCPN WILL STAY TO THE SOUTH OF THE CWA. TEMPS WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE MID 40S TO AROUND 50 OVER MUCH OF UPPER MICHIGAN. HOWEVER...OVER N CNTRL UPPER MI AND THE KEWEENAW...THE EAST WIND OFF OF LAKE SUPERIOR WILL KEEP HIGHS FROM AROUND 40 TO 45. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 417 PM EDT SAT APR 26 2014 UPPER LOW BEGINS THE LONG TERM PERIOD LUMBERING OUT OF THE SOUTHWEST CONUS ACROSS THE CENTRAL PLAINS. SFC LOW NEARBY THE UPPER LOW CENTER WHILE HIGH PRESSURE RIDGE EXTENDS SOUTHWARD FROM HUDSON BAY TO THE GREAT LAKES. UPPER LOW AND ASSOCIATED BLOCKING ALOFT ON ITS EDGES WILL BE MAIN WEATHER INSTIGATORS FOR THE UPCOMING WEEK. IT SEEMS TO ALWAYS BE A STRUGGLE FOR THE MODELS WITH THIS TYPE OF SITUATION WHERE THE UPPER LOW AND ASSOCIATED MOISTURE TRANSPORT RUN INTO THE SFC HIGH AND DRY LOW-LEVEL AIR. MOISTURE ADVECTION ALOFT COULD ALLOW FOR A LOT OF MID CLOUDS AND PERHAPS SOME LGT RAIN OVER THE SOUTHERN CWA MONDAY AFTN INTO MONDAY EVENING. FARTHER NORTH...THINK LOWER SFC-H85 RH OUT OF THE HUDSON BAY HIGH WILL LIMIT ANY PRECIP TO ISOLD SHOWERS OR SPRINKLES. EAST-NORTHEAST WINDS WILL KEEP LK SUPERIOR AREAS IN THE LOWER 40S ON MONDAY...BUT INLAND AREAS CLOSER TO WI BORDER AND OVER THE EASTERN CWA MAY BE ABLE TO PUSH INTO THE 50S WITH BETTER MIXING HEIGHTS UP TO H85. POSSIBLE THAT MID 50S COULD OCCUR OVER FAR EAST IF CLOUDS HOLD OFF LONG ENOUGH. ENOUGH CONFIDENCE THAT ONCE TUESDAY AND WEDNESDAY ARRIVE...UPPER LOW WILL BE EXERTING ENOUGH OF AN INFLUENCE TO RESULT IN PRECIPITATION ACROSS THE CWA. EAST WINDS WITH CLOUDS AND PRECIP WILL KEEP TEMPS IN ALL AREAS WELL BLO NORMAL...WITH HIGHS THIS PERIOD UPR 30S TO LOW 40S NEAR LK SUPERIOR AND MAINLY IN THE 40S INLAND. AS IT APPEARS NOW...AND THIS IS SUBJECT TO CHANGE...SEEMS THAT PRECIPITATION COMES IN TWO WAVES. FIRST MAIN AREA OF PRECIPITATION SUPPORTED BY INITIAL SHORTWAVES ROTATING AROUND THE UPR LOW AND H85-H7 MOISTURE TRANSPORT LIFTS ACROSS THE CWA ON TUESDAY. GFS AND ECMWF SUGGESTS STEADIER PRECIP COULD CHANGE TO MAINLY DRIZZLE TUESDAY AFTN INTO TUESDAY EVENING. PTYPE COULD BE AN ISSUE INITIALLY AS H85 TEMPS BLO ZERO OVER THE WESTERN CWA AND SFC TEMPS IN THE LOW-MID 30S MONDAY NIGHT INTO TUESDAY MORNING POINT TO POSSIBLE RAIN/SNOW MIX. 1000-850MB THICKNESSES RIGHT ON THE 1300-1305M LINE WOULD INDICATE DIFFERENCE BTWN SEEING RAIN...SNOW...OR A MIX WILL BE DEPENDANT ON ELEVATION HEIGHT. THERE IS NOT A LOT OF PRECIP EXPECTED MOST OF MONDAY NIGHT FOR AREAS IN THE RAIN/SNOW ZONE...BUT PRECIP TUESDAY MORNING COULD BE MORE IMPACTED. WOULD NOT BE SURPRISED TO SEE SLUSHY SNOW ACCUMS ON TUESDAY MORNING OVER THE HIGHER TERRAIN OF THE NORTHWEST AND NORTH CENTRAL CWA. ANY MIX WOULD CHANGE TO RAIN IN THE AFTN AS RELATIVELY WARMER AIR ARRIVES FROM THE SOUTH. KEPT RAIN CHANCES FOR TUESDAY NIGHT BUT IT COULD BE DRIZZLE AT TIMES. BEST CHANCE OF RAIN OVER THE EASTERN CWA AHEAD OF STRONGER SHORTWAVE LIFTING IN LATER TUESDAY NIGHT. SHORTWAVE LIFTS ACROSS AREA ON WEDNESDAY WHICH IS ALSO WHEN MAIN SFC LOW ARRIVES OVER THE REGION. EVEN THOUGH BETTER MOISTURE TRANSPORT IS HEADING EAST BY THAT TIME...THERE IS HINT OF WARM AND MOIST AIR WRAPPING BACK ACROSS UPR LAKES AS THE SFC LOW BEGINS TO OCCLUDE. KIND OF EARLY TO BE LOOKING AT TROWAL SPECIFICS BUT THAT MAY BE WHAT MODELS ARE KEYING ON TO BOOST QPF TOTALS ALONG TRACK OF H85 LOW TRACK. UPSLOPE NNW FLOW MAY ALSO INCREASE TOTALS OVER WEST AND NCNTRL LATER WEDNESDAY INTO WEDNESDAY NIGHT. STILL APPEARS THAT TOTAL PRECIP TUESDAY AND WEDNESDAY...AT LEAST IN SOME AREAS...MAY REACH 1 TO 1.5 INCHES. LATER WEDNESDAY NIGHT INTO THURSDAY MAY HAVE TO DEAL WITH MORE PTYPE ISSUES AGAIN AS VERTICALLY STACKED LOW PRESSURE ALLOWS FOR GRADUALLY COOLING TEMPERATURES JUST ABOVE SFC. H85 TEMPS DROP BACK BLO 0C SO COULD SEE MORE RAIN AND SNOW MIX FOR THE WEST HALF OF CWA WEDNESDAY NIGHT INTO THURSDAY MORNING. UNRAVELLING UPPER/SFC LOWS ONLY SLOWLY MOVE OUT OF THE AREA LATE THIS WEEK. ADDITIONAL SHORTWAVES MAY BRING MORE UNSETTLED WEATHER FRIDAY INTO SATURDAY /BOTH RAIN AND SNOW POSSIBLE/...BUT GRADUALLY POPS WILL DROP BACK TO SLIGHT CHANCES BY THAT TIME. CONSENSUS MAX TEMPS CONTINUING TO STAY BLO NORMAL ARE NOT NECESSARILY DESIRED...BUT APPEAR REASONABLE TO CLOSE THE LONG TERM PERIOD. MADE FEW CHANGES TO CONSENSUS TEMPS/POPS/WINDS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 148 PM EDT SAT APR 26 2014 AS DRIER AIR MOVES IN FROM THE NORTH AND DAYTIME MIXING CONTINUES...EXPECT MVFR CIGS TO GIVE WAY TO VFR CONDITIONS BY MID TO LATE AFTERNOON. VFR CONDITIONS WILL THEN PREVAIL THROUGH THE REST OF THE TAF PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 417 PM EDT SAT APR 26 2014 EAST WINDS INCREASE ON SUNDAY INTO SUNDAY NIGHT AS LOW PRESSURE DEEPENS OVER THE PLAINS. GUSTS COULD REACH GALE FORCE TO 35KTS OVER FAR WESTERN LK SUPERIOR TOWARD DULUTH BY LATE AFTERNOON. EAST GALES ARE THEN EXPECTED SUN NIGHT INTO MON OVER THE WEST. WINDS WILL GRADUALLY DIMINISH MON NIGHT INTO TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE. WINDS ARE EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED INTO THU AS THE LOW FILLS AND REMAINS NEAR UPPER MICHIGAN. && .HYDROLOGY... ISSUED AT 417 PM EDT SAT APR 26 2014 RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER NEAR NAHMA JUNCTION. WHILE THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER NEAR NAHMA JUNCTION ARE NOT EXPECTED TO REACH FLOOD STAGE IN THE SHORT TERM...THE STURGEON RIVER NEAR CHASSELL REMAINS NEAR FLOOD STAGE AND IS EXPECTED TO REMAIN STEADY FOR THE REST OF THE WEEKEND. REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE. A LARGE LOW PRESSURE SYSTEM WILL MOVE INTO THE GREAT LAKES BY THE MIDDLE OF NEXT WEEK. PERIODS OF RAIN ARE POSSIBLE FROM LATE MONDAY THROUGH THURSDAY WITH THE POTENTIAL FOR TOTAL AMOUNTS OF AN INCH TO AN INCH AND A HALF. THIS WOULD ADD TO THE FLOOD RISK...ESPECIALLY OVER THE NORTHWEST HALF OF UPPER MICHIGAN WHERE SNOWMELT WILL ALSO ADD TO THE RUNOFF. WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. HOWEVER...THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS OVER THE NEXT WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY EVENING FOR LSZ162. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...JLB MARINE...JLB HYDROLOGY...JLA
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1025 AM CDT SAT APR 26 2014 .UPDATE...SUNNY SKIES PREVAIL THIS MORNING ACROSS THE ARKLAMISS. TEMPERATURES LATE THIS MORNING WERE MAINLY IN THE LOW TO MID 70S...WITH AFTERNOON HIGHS EXPECTED TO REACH THE MID 80S. AS FOR THE CURRENT FORECAST...WENT AHEAD AND ADDED A MENTION OF THUNDER TO THE SHOWER ACTIVITY FOR LATER THIS AFTERNOON ALONG AND SOUTH OF THE I20 CORRIDOR DUE TO SOME ELEVATED INSTABILITY. ONLY OTHER CHANGE WAS TO MAKE SOME SLIGHT ADJUSTMENTS TO THE CLOUD COVER FOR THIS MORNING INTO THE EARLY AFTERNOON HOURS. /27/ && .AVIATION...CLEAR SKIES WERE BEING OBSERVED AT 15Z. THE STALLED BOUNDARY JUST SOUTH OF HBG WILL BEGIN LIFTING NORTH THIS AFTN. THIS WL BRING AN INCREASE IN CLOUD COVER AND A SLIGHT CHANCE OF A SHOWER OT TSTM...ALONG AND SOUTH OF INTERSTATE 20. OTHERWISE...VFR CONDITIONS WL CONTINUE THROUGH THIS EVENING. WIDESPREAD IFR CATEGORY STRATUS IS EXPECTED TO SPREAD NORTH ACROSS THE FORECAST AREA TOWARD 10Z SUNDAY. TSTM POTENTIAL WILL BE ON THE INCREASE SUNDAY INTO SUNDAY NIGHT AS A POTENT LOW PRESSURE SYSTEM APPROACHES. THIS LOW PRESSURE SYSTEM WL TAKE UNTIL WEDNESDAY TO SHIFT EAST OF OUR AREA RESULTING IN A STRETCH OF ROUGH WEATHER FOR AVIATION INTERESTS SUN THROUGH TUESDAY. /EC/22/ && .PREV DISCUSSION... /ISSUED 513 AM CDT SAT APR 26 2014/ ..SEVERE WEATHER OUTBREAK EXPECTED FROM SUNDAY NIGHT THROUGH TUESDAY AND SIGNIFICANT FLOOD EVENT POSSIBLE AS WELL... DISCUSSION... TODAY AND TONIGHT... THERE IS A WRINKLE IN WHAT WAS SUPPOSED TO CLEARLY BE A DRY FORECAST FOR SATURDAY. THE NCEP WRF AND HRRR GUIDANCE SUGGEST AN EAST-WEST ORIENTED BROKEN LINE OF SHOWERS MAY DEVELOP LATER TODAY WITH DAYTIME HEATING ALONG THE NORTHERN EDGE OF RICHER LOW LEVEL MOISTURE NEAR THE GULF COAST. HAVE RAISED POPS TO SLIGHT CHANCE CATEGORY FOR LOCATIONS ALONG AND SOUTH OF I-20. CONFIDENCE IS LOW IN THIS ACTIVITY MATERIALIZING GIVEN THE DRY AIR (PRECIPITABLE WATER < .50 INCH) THAT NEEDS TO BE OVERCOME AND GENERAL LACK OF LIFT ON ANY SCALE. EXPECT ANY SHOWER ACTIVITY TO DIMINISH QUICKLY WITH SUNSET THIS EVENING. OTHERWISE...EXPECT INCREASING LOW CLOUDS AS HIGHER QUALITY BOUNDARY LAYER MOISTURE BEGINS TO SURGE INLAND. SUNDAY THROUGH MONDAY NIGHT... HIGH FORECAST CONFIDENCE CONTINUES REGARDING A DANGEROUS SET-UP FOR SEVERE WEATHER AND HEAVY RAINFALL FROM LATE SUNDAY THROUGH TUESDAY NIGHT. ALL MODES OF SEVERE WEATHER INCLUDING THE POTENTIAL FOR STRONG TORNADOES WILL BE POSSIBLE AS A LARGE AND DEEP VORTEX LOCKS IN OVER THE CENTRAL CONUS AND SENDS SEVERAL LOBES OF SHORTWAVE TROUGH ENERGY ACROSS THE ARKLAMISS. GIVEN THE PERSISTENCE OF THIS PATTERN AND AVAILABILITY OF ANOMALOUS MOISTURE...A SIGNIFICANT FLOODING EVENT IS PROBABLE AS WELL. THE RISK FOR SEVERE WEATHER COULD RAMP UP QUICKLY LATE SUNDAY AFTERNOON INTO THE EVENING IN THE DELTA REGION. GUIDANCE CONTINUES TO INDICATE THAT RAPID MOISTENING AND DESTABILIZATION ASSOCIATED WITH INCREASINGLY CYCLONIC FLOW ALOFT WILL ALLOW FOR SHOWER/THUNDERSTORM ACTIVITY TO BREAK OUT AS EARLY AS SUNDAY MORNING. BY SUNDAY AFTERNOON AND EVENING A VERY UNSTABLE (ML CAPE > 2500 J/KG) AND HIGHLY SHEARED ENVIRONMENT (0-1KM ~45 KTS) IS EXPECTED AS LAPSE RATES STEEPEN ABOVE A STRENGTHENING LOW LEVEL JET (50-60KTS). LARGE CLOCKWISE HODOGRAPHS WILL SUPPORT SUPERCELL THUNDERSTORMS WITH INTENSE ROTATING UPDRAFTS AND STRONG TORNADO POTENTIAL OVER THE DELTA REGION BY SUNDAY EVENING. CONFIDENCE IS INCREASING THAT THE GREATER RISK FOR SEVERE WEATHER WILL REMAIN MAINLY OVER THE DELTA REGION SUNDAY NIGHT. BUT A QUASI-LINEAR CONVECTIVE SYSTEM COULD EVENTUALLY EVOLVE...AND IF THIS HAPPENS WE WOULD EXPECT COLD POOL GENERATION TO HELP GIVE THE SYSTEM SOME EASTWARD ACCELERATION ALONG THE HWY 82 CORRIDOR...PERHAPS REACHING THE NATCHEZ TRACE CORRIDOR. IT IS UNCLEAR HOW MUCH SUCH AN MCC WILL DIMINISH DURING THE EARLY MONDAY MORNING HOURS...BUT THERE MAY BE SOMEWHAT OF A LULL BEFORE THE NEXT ROUND OF SHORTWAVE ENERGY APPROACHES. AS WE GO INTO MONDAY AFTERNOON AND EVENING...EXPECT RE-NEWED SEVERE THUNDERSTORM ACTIVITY WHEN A RIBBON OF STRONGER PACIFIC JET ENERGY ROUNDS THE BASE OF THE DEEP CENTRAL CONUS TROUGH AND ENHANCES WIND SHEAR/LIFT AND THE SEVERE WEATHER RISK OVER THE FORECAST AREA. MIXED LAYER CAPE NEAR 3000 J/KG COULD HELP MAKE FOR A VOLATILE SET-UP WITH THIS SYNOPTIC PATTERN. THE INITIAL CONVECTION SHOULD EVENTUALLY EVOLVE INTO ANOTHER LINEAR CONVECTIVE SYSTEM...AND WITH DEEP LAYER SHEAR VECTORS BECOMING MORE PARALLEL RESULTING IN GREATER POTENTIAL FOR TRAINING AND BACK-BUILDING OF STORMS...THE RISK FOR HEAVY RAINFALL AND FLOODING COULD REALLY RAMP UP MONDAY NIGHT. THE ECMWF IS A LITTLE MORE PROGRESSIVE WITH SUCH A SYSTEM WHILE THE GFS SHOWS A GREATER PROPENSITY FOR PARALLEL DEEP LAYER FLOW AND CORFIDI VECTOR RIDGING SUGGESTIVE OF MCS BACK-BUILDING AND SLOW SYSTEM SPEED. WHILE IT IS DIFFICULT TO KNOW WHERE IT WILL SET UP EXACTLY...WITH K INDICES IN THE LOW 40S AND PRECIPITABLE WATER APPROACHING 2 INCHES...THERE WILL LIKELY BE INTENSE RAINFALL RATES OF WHICH ANY LONG DURATION COULD LEAD TO SERIOUS FLOODING CONCERNS. CIPS ANALOGS ARE STILL SHOWING VERY SIGNIFICANT EVENTS FOR COMPARISON TO THIS SET-UP ADDING MORE CONFIDENCE THAT SIGNIFICANT SEVERE WEATHER AND FLOODING WILL BE POSSIBLE. THE LATEST ANALOG CONSENSUS HAS SHIFTED BACK A LITTLE FARTHER NORTH WITH HIGHER SEVERE WEATHER/HEAVY RAINFALL PROBS FROM SUNDAY NIGHT THROUGH MONDAY NIGHT...BEFORE SHIFTING SOUTHWARD FOR THE TIME CENTERED ON THE MORE UNCERTAIN TUESDAY EVENING PERIOD. TO MAINTAIN CONSISTENCY WILL NOT MAKE ANY SIGNIFICANT ADJUSTMENTS AT THIS POINT TO THE RISK AREAS...BUT WILL ADD SOME MORE DETAIL. /EC/ TUESDAY THROUGH NEXT SATURDAY... A VOLATILE PATTERN SUPPORTIVE OF SEVERE WEATHER/TORNADOES AND ADDITIONAL HEAVY RAIN MAY CONTINUE TUESDAY INTO TUESDAY NIGHT. THE FORECAST FOR THIS PERIOD IS MORE UNCERTAIN HOWEVER AS IT WILL HINGE GREATLY ON THE BEHAVIOR OF MONDAY NIGHT CONVECTIVE ACTIVITY. A STRONG CLOSED H5 CLOSED LOW WILL EXIST OVER IOWA EARLY TUESDAY WHICH IS CHARACTERIZED BY A 120KT CYCLONICALLY CURVED JET WITH MULTIPLE EJECTING LOBES OVERTOP A MOIST UNSTABLE MODERATELY SHEARED ENVIRONMENT ACROSS THE ARKLAMISS. THIS SET-UP WILL SUPPORT VIGOROUS CONVECTIVE DEVELOPMENT AGAIN FOR TUESDAY AFTERNOON AND EVENING. ADDITIONAL HEAVY RAIN WILL BE POSSIBLE WITH PRECIPITABLE WATER AROUND 1.8 INCHES AND FAVORABLE WIND PROFILES FOR TRAINING OF STORMS LEADING TO FLASH FLOODING AND SIGNIFICANT RIVER RISES. THE ASSOCIATED COLD FRONT WILL FINALLY MOVE THROUGH THE REGION BY EARLY WEDNESDAY. AS WE GO INTO WEDNESDAY THE LAST OF THE CONVECTION WILL EXIT THE REGION BY WEDNESDAY AFTERNOON. A BROAD UPPER TROUGH WILL CONTINUE OVER THE REGION FOR MOST OF THE PERIOD THROUGH FRIDAY BEFORE THE UPPER TROUGH FINALLY LIFTS OUT OVER THE WEEKEND. THE MODEL GUIDANCE TRIES TO BRING IN LOW POPS FOR WEDNESDAY THROUGH SATURDAY. THE EURO TRIED TO SHOW SOME LOW QPF FROM THURSDAY THROUGH SATURDAY...BUT OPTED TO KEEP THE REGION DRY. SOME COOL AIR WILL PUSH INTO THE REGION FOR THURSDAY INTO FRIDAY WITH LOWS IN THE 40S AND 50S REACHING INTO THE FIRST FEW DAYS OF MAY...WHICH WILL RUN AROUND TEN DEGREES BELOW NORMAL. /17/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 85 66 82 69 / 18 12 30 43 MERIDIAN 85 63 83 66 / 13 9 24 30 VICKSBURG 85 68 82 71 / 18 14 41 53 HATTIESBURG 87 67 83 68 / 19 12 20 22 NATCHEZ 85 68 84 70 / 20 12 32 37 GREENVILLE 84 67 80 69 / 5 18 71 79 GREENWOOD 86 67 82 70 / 4 11 56 63 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 27/22/EC/17
AREA FORECAST DISCUSSION
NWS JACKSON MS
513 AM CDT SAT APR 26 2014 ...SEVERE WEATHER OUTBREAK EXPECTED FROM SUNDAY NIGHT THROUGH TUESDAY AND SIGNIFICANT FLOOD EVENT POSSIBLE AS WELL... .DISCUSSION... TODAY AND TONIGHT... THERE IS A WRINKLE IN WHAT WAS SUPPOSED TO CLEARLY BE A DRY FORECAST FOR SATURDAY. THE NCEP WRF AND HRRR GUIDANCE SUGGEST AN EAST-WEST ORIENTED BROKEN LINE OF SHOWERS MAY DEVELOP LATER TODAY WITH DAYTIME HEATING ALONG THE NORTHERN EDGE OF RICHER LOW LEVEL MOISTURE NEAR THE GULF COAST. HAVE RAISED POPS TO SLIGHT CHANCE CATEGORY FOR LOCATIONS ALONG AND SOUTH OF I-20. CONFIDENCE IS LOW IN THIS ACTIVITY MATERIALIZING GIVEN THE DRY AIR (PRECIPITABLE WATER < .50 INCH) THAT NEEDS TO BE OVERCOME AND GENERAL LACK OF LIFT ON ANY SCALE. EXPECT ANY SHOWER ACTIVITY TO DIMINISH QUICKLY WITH SUNSET THIS EVENING. OTHERWISE...EXPECT INCREASING LOW CLOUDS AS HIGHER QUALITY BOUNDARY LAYER MOISTURE BEGINS TO SURGE INLAND. SUNDAY THROUGH MONDAY NIGHT... HIGH FORECAST CONFIDENCE CONTINUES REGARDING A DANGEROUS SET-UP FOR SEVERE WEATHER AND HEAVY RAINFALL FROM LATE SUNDAY THROUGH TUESDAY NIGHT. ALL MODES OF SEVERE WEATHER INCLUDING THE POTENTIAL FOR STRONG TORNADOES WILL BE POSSIBLE AS A LARGE AND DEEP VORTEX LOCKS IN OVER THE CENTRAL CONUS AND SENDS SEVERAL LOBES OF SHORTWAVE TROUGH ENERGY ACROSS THE ARKLAMISS. GIVEN THE PERSISTENCE OF THIS PATTERN AND AVAILABILITY OF ANOMALOUS MOISTURE...A SIGNIFICANT FLOODING EVENT IS PROBABLE AS WELL. THE RISK FOR SEVERE WEATHER COULD RAMP UP QUICKLY LATE SUNDAY AFTERNOON INTO THE EVENING IN THE DELTA REGION. GUIDANCE CONTINUES TO INDICATE THAT RAPID MOISTENING AND DESTABILIZATION ASSOCIATED WITH INCREASINGLY CYCLONIC FLOW ALOFT WILL ALLOW FOR SHOWER/THUNDERSTORM ACTIVITY TO BREAK OUT AS EARLY AS SUNDAY MORNING. BY SUNDAY AFTERNOON AND EVENING A VERY UNSTABLE (ML CAPE > 2500 J/KG) AND HIGHLY SHEARED ENVIRONMENT (0-1KM ~45 KTS) IS EXPECTED AS LAPSE RATES STEEPEN ABOVE A STRENGTHENING LOW LEVEL JET (50-60KTS). LARGE CLOCKWISE HODOGRAPHS WILL SUPPORT SUPERCELL THUNDERSTORMS WITH INTENSE ROTATING UPDRAFTS AND STRONG TORNADO POTENTIAL OVER THE DELTA REGION BY SUNDAY EVENING. CONFIDENCE IS INCREASING THAT THE GREATER RISK FOR SEVERE WEATHER WILL REMAIN MAINLY OVER THE DELTA REGION SUNDAY NIGHT. BUT A QUASI-LINEAR CONVECTIVE SYSTEM COULD EVENTUALLY EVOLVE...AND IF THIS HAPPENS WE WOULD EXPECT COLD POOL GENERATION TO HELP GIVE THE SYSTEM SOME EASTWARD ACCELERATION ALONG THE HWY 82 CORRIDOR...PERHAPS REACHING THE NATCHEZ TRACE CORRIDOR. IT IS UNCLEAR HOW MUCH SUCH AN MCC WILL DIMINISH DURING THE EARLY MONDAY MORNING HOURS...BUT THERE MAY BE SOMEWHAT OF A LULL BEFORE THE NEXT ROUND OF SHORTWAVE ENERGY APPROACHES. AS WE GO INTO MONDAY AFTERNOON AND EVENING...EXPECT RE-NEWED SEVERE THUNDERSTORM ACTIVITY WHEN A RIBBON OF STRONGER PACIFIC JET ENERGY ROUNDS THE BASE OF THE DEEP CENTRAL CONUS TROUGH AND ENHANCES WIND SHEAR/LIFT AND THE SEVERE WEATHER RISK OVER THE FORECAST AREA. MIXED LAYER CAPE NEAR 3000 J/KG COULD HELP MAKE FOR A VOLATILE SET-UP WITH THIS SYNOPTIC PATTERN. THE INITIAL CONVECTION SHOULD EVENTUALLY EVOLVE INTO ANOTHER LINEAR CONVECTIVE SYSTEM...AND WITH DEEP LAYER SHEAR VECTORS BECOMING MORE PARALLEL RESULTING IN GREATER POTENTIAL FOR TRAINING AND BACK-BUILDING OF STORMS...THE RISK FOR HEAVY RAINFALL AND FLOODING COULD REALLY RAMP UP MONDAY NIGHT. THE ECMWF IS A LITTLE MORE PROGRESSIVE WITH SUCH A SYSTEM WHILE THE GFS SHOWS A GREATER PROPENSITY FOR PARALLEL DEEP LAYER FLOW AND CORFIDI VECTOR RIDGING SUGGESTIVE OF MCS BACK-BUILDING AND SLOW SYSTEM SPEED. WHILE IT IS DIFFICULT TO KNOW WHERE IT WILL SET UP EXACTLY...WITH K INDICES IN THE LOW 40S AND PRECIPITABLE WATER APPROACHING 2 INCHES...THERE WILL LIKELY BE INTENSE RAINFALL RATES OF WHICH ANY LONG DURATION COULD LEAD TO SERIOUS FLOODING CONCERNS. CIPS ANALOGS ARE STILL SHOWING VERY SIGNIFICANT EVENTS FOR COMPARISON TO THIS SET-UP ADDING MORE CONFIDENCE THAT SIGNIFICANT SEVERE WEATHER AND FLOODING WILL BE POSSIBLE. THE LATEST ANALOG CONSENSUS HAS SHIFTED BACK A LITTLE FARTHER NORTH WITH HIGHER SEVERE WEATHER/HEAVY RAINFALL PROBS FROM SUNDAY NIGHT THROUGH MONDAY NIGHT...BEFORE SHIFTING SOUTHWARD FOR THE TIME CENTERED ON THE MORE UNCERTAIN TUESDAY EVENING PERIOD. TO MAINTAIN CONSISTENCY WILL NOT MAKE ANY SIGNIFICANT ADJUSTMENTS AT THIS POINT TO THE RISK AREAS...BUT WILL ADD SOME MORE DETAIL. /EC/ TUESDAY THROUGH NEXT SATURDAY... A VOLATILE PATTERN SUPPORTIVE OF SEVERE WEATHER/TORNADOES AND ADDITIONAL HEAVY RAIN MAY CONTINUE TUESDAY INTO TUESDAY NIGHT. THE FORECAST FOR THIS PERIOD IS MORE UNCERTAIN HOWEVER AS IT WILL HINGE GREATLY ON THE BEHAVIOR OF MONDAY NIGHT CONVECTIVE ACTIVITY. A STRONG CLOSED H5 CLOSED LOW WILL EXIST OVER IOWA EARLY TUESDAY WHICH IS CHARACTERIZED BY A 120KT CYCLONICALLY CURVED JET WITH MULTIPLE EJECTING LOBES OVERTOP A MOIST UNSTABLE MODERATELY SHEARED ENVIRONMENT ACROSS THE ARKLAMISS. THIS SET-UP WILL SUPPORT VIGOROUS CONVECTIVE DEVELOPMENT AGAIN FOR TUESDAY AFTERNOON AND EVENING. ADDITIONAL HEAVY RAIN WILL BE POSSIBLE WITH PRECIPITABLE WATER AROUND 1.8 INCHES AND FAVORABLE WIND PROFILES FOR TRAINING OF STORMS LEADING TO FLASH FLOODING AND SIGNIFICANT RIVER RISES. THE ASSOCIATED COLD FRONT WILL FINALLY MOVE THROUGH THE REGION BY EARLY WEDNESDAY. AS WE GO INTO WEDNESDAY THE LAST OF THE CONVECTION WILL EXIT THE REGION BY WEDNESDAY AFTERNOON. A BROAD UPPER TROUGH WILL CONTINUE OVER THE REGION FOR MOST OF THE PERIOD THROUGH FRIDAY BEFORE THE UPPER TROUGH FINALLY LIFTS OUT OVER THE WEEKEND. THE MODEL GUIDANCE TRIES TO BRING IN LOW POPS FOR WEDNESDAY THROUGH SATURDAY. THE EURO TRIED TO SHOW SOME LOW QPF FROM THURSDAY THROUGH SATURDAY...BUT OPTED TO KEEP THE REGION DRY. SOME COOL AIR WILL PUSH INTO THE REGION FOR THURSDAY INTO FRIDAY WITH LOWS IN THE 40S AND 50S REACHING INTO THE FIRST FEW DAYS OF MAY...WHICH WILL RUN AROUND TEN DEGREES BELOW NORMAL./17/ && .AVIATION...VFR CONDITIONS ARE ANTICIPATED FOR THE MOST PART TODAY THROUGH THIS EVENING. WIDESPREAD IFR CATEGORY STRATUS MAY SPREAD NORTH ACROSS THE FORECAST AREA LATE TONIGHT. THUNDERSTORM POTENTIAL WILL BE ON THE POTENTIAL FOR SUNDAY INTO SUNDAY NIGHT...AND EARLY NEXT WEEK LOOKS LIKE A STRETCH OF ROUGH WEATHER FOR AVIATION INTERESTS. /EC/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 85 66 82 69 / 18 12 30 43 MERIDIAN 85 63 83 66 / 13 9 24 30 VICKSBURG 85 68 82 71 / 18 14 41 53 HATTIESBURG 87 67 83 68 / 19 12 20 22 NATCHEZ 85 68 84 70 / 20 12 32 37 GREENVILLE 84 67 80 69 / 5 18 71 79 GREENWOOD 86 67 82 70 / 4 11 56 63 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ EC/17/
AREA FORECAST DISCUSSION
NWS BILLINGS MT
328 PM MDT SAT APR 26 2014 .SHORT TERM...VALID FOR SUN AND MON... SCATTERED SHOWERS AND THUNDERSTORMS WERE MOVING N TOWARD THE FORECAST AREA FROM WY THIS AFTERNOON PER RADAR IMAGERY AND LIGHTNING DATA. CAPES HAVE BEEN INCREASING OVER THE AREA SO HAVE INCREASED THE CHANCE OF THUNDER FOR THIS EVENING. THE CAPES WERE FORECAST TO DIMINISH BY THE RAP AFTER 03Z...SO WILL ONLY HAVE A SLIGHT CHANCE OF THUNDER FOR THE LATE EVENING. BULK SHEAR WAS ALSO FAVORABLE ACROSS THE REGION IN SUPPORT OF THUNDERSTORMS. COMPACT UPPER LOW WAS SEEN ON WATER VAPOR IMAGERY MOVING THROUGH AZ THIS AFTERNOON. PLENTY OF MOISTURE WAS SPREADING N OUT FROM THE LOW IN SW FLOW ALOFT. MODELS AGREED THAT THE UPPER LOW WILL REACH SE CO BY 12Z SUN...ALLOWING THE TROUGH TO GO NEGATIVE TILT AND TAP GULF OF MEXICO MOISTURE. THE LOW WILL MERGE WITH THE NORTHERN BRANCH OF THE TROUGH AS IT MOVES NE THROUGH MON INTO THE CENTRAL PLAINS. THE LARGER CUTOFF WILL THEN MEANDER E MON NIGHT. AT THE SURFACE...AMORPHOUS LOW CENTERS WERE ALONG THE SOUTHERN EDGE OF THE FORECAST AREA THIS AFTERNOON. THESE LOWS WERE FORECAST TO MERGE OVER NE OR E CO BY 12Z SUN WITH AN INVERTED TROUGH EXTENDING FROM THE MERGED LOW INTO THE EASTERN FORECAST AREA. A HALF INCH TO AN INCH OF QPF WILL FALL OVER THE WESTERN ZONES TONIGHT BEFORE THE PRECIPITATION FOCUS SHIFTS TO SE MT...E OF KBIL...DURING SUN MORNING DUE TO THE INVERTED TROUGH. THE INVERTED TROUGH WILL SHIFT SLOWLY E DURING SUN AND A HALF INCH TO AN INCH OF PRECIPITATION IS EXPECTED TO FALL OVER SE MT. THE BEST CHANCES FOR SNOW WILL BE THIS EVENING OVER THE BEARTOOTHS AND ABSAROKAS DUE TO A COMBINATION OF LIFT AND INSTABILITY...BUT DENDRITIC GROWTH WILL BE HIGHER IN THE ATMOSPHERE LIMITING THE GREATER ACCUMULATIONS TO THE HIGHEST ELEVATIONS. THE MAJORITY OF THE MODELS KEPT THE INVERTED TROUGH AND ASSOCIATED PRECIPITATION GOING OVER THE SE THROUGH MON WITH THE ECMWF BEING FURTHEST E OVER THE DAKOTAS. ANOTHER THREE-QUARTERS OF AN INCH OF PRECIPITATION WILL BE POSSIBLE SUN NIGHT...WITH MUCH LESSER AMOUNTS EXPECTED MON. SOME LINGERING PRECIPITATION IS EXPECTED OVER THE SE MON NIGHT. CONTINUED THE FORECAST OF RAIN MIXING WITH THE SNOW LATE SUN NIGHT AND MON NIGHT. A COUPLE INCHES OF SNOW WILL BE POSSIBLE OVER THE SE SUN NIGHT. ONLY MADE SLIGHT POP AND TEMPERATURE ADJUSTMENTS THROUGH THE PERIOD. HIGHS WILL BE IN THE 40S AND 50S SUN AND MON. STILL EXPECTING GUSTY NW WINDS BEHIND THE SURFACE LOW BEGINNING TONIGHT. WILL CONTINUE THE ESF FOR RISING RIVERS AND STREAMS. ARTHUR .LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT... THE LARGE SCALE SYNOPTIC PATTERN ACROSS THE CONUS WILL EVOLVE SLOWLY THROUGH MIDDLE TO LATE NEXT WEEK AS A BLOCKING PATTERN CONTINUES. TUESDAY THROUGH THURSDAY THE LARGE UPPER-LEVEL LOW WILL DRIFT FROM THE CENTRAL PLAINS TO THE GREAT LAKES AREA... WHICH WILL RESULT IN A CONTINUED WET AND COOL PATTERN FOR THE EASTERN PORTIONS OF THE FORECAST AREA. THE MOISTURE TRANSPORT WILL SLOWLY DIMINISH EACH DAY... AND WILL ALLOW PRECIPITATION TO SLOWLY TAPER OFF. WHILE MODELS HAVE CONTINUED TO SHOW SLOW BREAKDOWN OF THE BLOCKING PATTERN... THURSDAY WILL FINALLY BE WARMER AND DRIER AS ANTICYCLONIC FLOW FINALLY BUILDS IN ALOFT ALONG WITH WARMER 850 MB TEMPERATURES. THE MODEL TREND HAS BEEN TOWARD A SLIGHTLY SLOWER PROGRESSION OF THE MEAN UPPER-LEVEL LOW ON TUESDAY AND WEDNESDAY... WHICH WILL COMBINE WITH SOME ADDITIONAL VORTICITY BEING ADVECTED IN TO THE FORECAST AREA FROM THE EAST ON TUESDAY. THIS WILL MAKE FOR A WETTER TUESDAY ACROSS EASTERN MONTANA THAN WE INITIALLY THOUGHT. THUS...HAVE DECIDED TO INCREASE POPS TO LIKELIES FOR AREAS EAST OF FORSYTH ON TUESDAY AFTERNOON. TEMPERATURES WILL ALSO BE FAIRLY COOL ACROSS THE EAST ... WITH THERMAL PROFILES SHOWING THE POTENTIAL FOR SNOW TO MIX WITH RAIN EARLY TUESDAY MORNING AND THEN AGAIN EARLY WEDNESDAY MORNING. FARTHER WEST THE TEMPERATURES WILL SLOWLY START TO MODERATE INTO WEDNESDAY AS THE NORTH-SOUTH ORIENTED JET STREAM SLOWLY PUSHES EASTWARD AND ALLOWS FOR +10C 850 MB TEMPERATURES TO MOVE INTO THE WEST HALF OF THE FORECAST AREA. SHOWERS ARE STILL POSSIBLE ACROSS SOUTH CENTRAL MONTANA ON TUESDAY AND WEDNESDAY ... GIVEN SOME ADDITIONAL FORCING WRAPPING BACK AROUND THE LOW...HOWEVER THE MAIN DETERRENT TO REALIZING THIS POTENTIAL REMAINS THE STRONG NORTHWESTERLY DOWNSLOPE WINDS. ANOMALOUSLY STRONG NORTHWESTERLY WINDS WILL CONTINUE FOR MUCH OF THE FORECAST AREA ON TUESDAY..WITH THE WINDS SLOWLY TAPER- ING OFF WEDNESDAY INTO THURSDAY. THE PATTERN FAVORS STRONGEST WINDS ACROSS SOUTHEAST MONTANA AND INTO SHERIDAN WY GIVEN THE SURFACE LOW ACROSS THE CENTRAL CONUS SUPPORTING A TIGHT PRES- SURE GRADIENT ACROSS THE CENTRAL AND EASTERN CWA. CIPS ANALOG GUIDANCE SHOWS 50 TO 70 PCT CHANCE OF WIND GUSTS GREATER THAN 30 KTS FROM BILLINGS TO SHERIDAN AND ACROSS SE MT ON TUESDAY. AFTER THE WARMING AND DRYING TREND ON THURSDAY... MODEL SOLU- TIONS DIVERGE READILY. HOWEVER ... THE OVERALL TREND SEEMS TO BE TOWARD NORTHWESTERLY FLOW... WHICH KEEP US FROM WARMING UP SIGNIFICANTLY AND WILL KEEP A SLGT CHANCE OF PRECIPITATION IN THE FORECAST TO END THE WEEK. CHURCH && .AVIATION... SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP AND SPREAD INTO THE FORECAST AREA THIS EVENING. ACCOMPANYING THESE SHOWERS WILL BE MOUNTAIN OBSCURATIONS AS WELL AS LOCALIZED MVFR CONDITIONS. EXPECT TO SEE THUNDER ACTIVITY DECREASE THIS EVENING AS INSTABILITY LESS- ENS AFTER SUNSET. SHOWERS WILL BECOME MORE WIDESPREAD FOR THE AREA TONIGHT AND COULD EVEN BECOME HEAVY AT TIMES. CHURCH && .PRELIMINARY POINT TEMP/POPS... SUN MON TUE WED THU FRI SAT ----------------------------------------------------------- BIL 042/056 036/051 035/053 036/057 037/062 039/065 041/058 97/W 32/W 23/W 21/N 11/B 12/W 22/W LVM 035/057 033/047 032/051 033/057 035/060 035/062 037/061 +5/W 33/W 23/W 11/B 11/U 12/W 22/W HDN 041/056 033/051 035/052 033/058 032/061 035/066 038/059 89/W 65/W 34/W 42/W 11/B 12/W 22/W MLS 043/047 034/047 035/048 032/051 033/058 037/063 039/058 9+/R 97/O 56/R 53/W 11/B 12/W 22/W 4BQ 042/048 033/046 035/046 032/050 031/057 034/062 037/058 9+/R 97/O 56/R 53/W 11/B 12/W 22/W BHK 042/045 033/044 034/042 031/049 031/054 034/058 036/057 7+/R +8/O 66/R 43/W 12/W 12/W 22/W SHR 039/053 031/046 033/048 033/050 032/056 033/060 036/060 88/W 55/W 24/W 42/W 11/B 12/W 22/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GLASGOW MT
241 PM MDT SAT APR 26 2014 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY... NOT TOO MANY CHANGES IN REGARD TO CHANCES OF PRECIPITATION...BUT MODELS DID BACK OFF ON SNOW CHANCES/AMOUNTS. UPPER TROUGH THE MAIN WEATHER MAKER FOR THE AREA THROUGH THE PERIOD. PRECIPITATION WILL BE MAINLY CONVECTIVE INTO THIS EVENING THEN TRANSITION TO STRATIFORM BY SUNDAY. THEREFORE AMOUNTS TONIGHT WILL BE LOWER CONFIDENCE THAN SUNDAY. SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP THIS LATE THIS AFTERNOON AND MOVE NORTH. HRRR HAS THIS AREA INITIATING NEAR A BOUNDARY NEAR MILES CITY LATE THIS AFTERNOON AT ABOUT 4 PM. AREA GRADUALLY FILLS IN OVERNIGHT AND SUNDAY AS ISENTROPIC FLOW DEVELOPS. SUNDAY NIGHT AND MONDAY...ISENTROPIC FLOW CONTINUES AS THE UPPER LOW TROUGH CUTS OFF NEAR SD/NE. PERIOD OF RAIN LOOKS TO MOVE NW BACK INTO THE AREA MONDAY MORNING. THE EC KEEPS IT AWAY FROM THE WESTERN ZONES...SO LOWERED QPFS/POPS THERE. TEMPERATURES LOOK COLDER NOW OVER THE NE ZONES RATHER THAN OPHEIM AREA FOR SNOW OR A SNOW/RAIN MIX MAINLY MONDAY MORNING. CONFIDENCE IS STILL LOW BUT AN INCH STILL LOOKS POSSIBLE. TFJ .LONG TERM...MONDAY NIGHT THROUGH SATURDAY... BY MONDAY NIGHT THE LINGERING OUTER BANDS OF PRECIPITATION FROM THE CURRENT STORM SYSTEM WILL STILL BE AFFECTING NORTHEAST MONTANA...EVEN WITH THE CENTER OF THE 500-MB LOW BEING OVER KANSAS CITY. THIS WILL LIKELY MATERIALIZE FOR OUR CWA IN THE FORM OF SCATTERED BANDS OF RAIN SHOWERS...OCCASIONALLY MIXED WITH SNOW DURING THE NIGHTTIME AND OVER THE HIGHER ELEVATIONS. MONDAY NIGHT THROUGH TUESDAY...THE UPPER-LEVEL FLOW OVER NORTHEAST MONTANA WILL BE RATHER BENIGN. BY LATE THURSDAY NIGHT...A STRONG RIDGE OF HIGH PRESSURE WITH ITS AXIS DOWN THE SPINE OF THE CASCADE RANGE...WILL START TO PUSH INTO NORTHEAST MONTANA FROM THE WEST...WITH STRONGER FLOW ALOFT FROM THE NORTH. THIS WILL CLEAR OUT ANY REMAINING RAIN SHOWERS...CLEAR OUT THE SKIES...AND ALLOW TEMPERATURES TO WARM BACK UP TO MORE NORMAL LEVELS FOR THIS TIME OF YEAR. BMICKELSON PREVIOUS LONG TERM DISCUSSION...THE EXTENDED PERIOD BEGINS MONDAY EVENING WITH A LONG-WAVE STACKED UP LOW CENTERED OVER THE CENTRAL PLAINS. NORTHEAST MONTANA WILL STILL BE UNDER A WEAKENING INVERTED SURFACE TROUGH WITH WRAP- AROUND LIGHT PRECIPITATION INTO MID- WEEK. MONDAY NIGHT THE SURFACE LOW WILL BE SOMEWHERE OVER SOUTH DAKOTA. THIS WILL PULL COLDER AIR FROM CANADA SOUTH OVER NEMONT. THERE WILL BE SOME 850MB TEMPERATURES BELOW 0C. THIS CAA COULD RESULT IN SOME SNOW MIXING IN WITH THE RAIN. BUT QPF BY THEN WILL BE LIMITED...SO NOT EXPECTING MUCH IN THE WAY OF ACCUMULATION. A BLOCKING PATTERN FARTHER EAST WILL PREVENT THE LARGE TROUGH FROM MOVING EAST TOO QUICKLY. AN AMPLIFIED RIDGE BUILDS UP WEST OF THE ROCKY MOUNTAINS BUT DOES NOT ADVANCE MUCH...KEEPING NORTHEAST MONTANA UNDER THE INFLUENCE OF THE TROUGH AND KEEPING TEMPERATURE SEASONAL OR ON THE COOL SIDE AT LEAST THROUGH MID-WEEK. THE TRANSITION FROM THE INFLUENCE OF THE COOLER LOW AND THE WARMER RIDGE IS HARD TO DETERMINE. EXACTLY WHEN THE STATIONARY BOUNDARY BETWEEN THE COMPETING AIR MASSES WILL SHIFT EAST OF NORTHEAST MONTANA IS NOT CERTAIN WITHIN A COUPLE OF PERIODS. BUT AFTER MID- WEEK THE BOUNDARY COULD BE FAR ENOUGH EAST FOR TEMPERATURES TO ONCE AGAIN RISE ABOVE NORMAL. THE HIGH PRESSURE CONDITIONS WILL ALSO DRY THINGS OUT. TOWARDS THE END OF THE EXTENDED PERIOD THE GFS AND EC HAVE DIFFERENT IDEAS AS TO HOW THE PATTERN WILL PLAY OUT. BUT BOTH MODELS HINT AS COOLER AND WETTER CONDITIONS MOVING IN BY THE WEEKEND. SCT && .AVIATION... SYNOPSIS: THE LARGE AND POWERFUL SPRING STORM SYSTEM...SPREADING MULTIPLE PERIODS OF SHOWERS AND DRY SLOTS ACROSS MOST OF THE INTER-MOUNTAIN WEST AND ADJACENT HIGH PLAINS REGIONS WILL CONTINUE TO DO SO WELL THROUGH THE END OF THIS TAF CYCLE. FLIGHT CATEGORY: VFR TODAY THROUGH EARLY THIS AFTERNOON. ISOLATED MVFR WILL BE POSSIBLE WITH SOME VICINITY THUNDERSTORMS LATER THIS AFTERNOON INTO EARLY THIS EVENING. EXPECT WIDESPREAD IFR TO BORDERLINE LIFR TO LOCK INTO ALL TAF SITES AFTER MIDNIGHT TONIGHT. SKY/WEATHER: WITH SKIES CLEARING IN PART TODAY TO ALLOW SOME HEATING OF THE MOIST SURFACE LAYER...A FEW VICINITY THUNDERSTORMS WILL BE POSSIBLE DURING THE LATE AFTERNOON AND EVENING HOURS...ESPECIALLY FROM KGDV TOWARD KOLF. AFTER MIDNIGHT...CEILINGS WILL LOWER DRASTICALLY AND WIDESPREAD MODERATE TO HEAVY RAIN WILL SETTLE IN FOR ALL TAF SITES TOWARD THE END OF AND WELL BEYOND THIS TAF PERIOD. WIND: GENERALLY FROM THE EAST 20-30 MPH MID DAY...INCREASING 30-40 MPH THIS AFTERNOON...THEN DIMINISHING BACK TO 15-25 WITH THE ONSET OF HEAVY RAIN LATE TONIGHT. EXPECT CROSSWIND HAZARDS FOR NORTH-TO-SOUTH ORIENTED RUNWAYS. BMICKELSON && .GLASGOW WATCHES/WARNINGS/ADVISORIES... LAKE WIND ADVISORY UNTIL 6 AM MDT SUNDAY FOR FORT PECK LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY... GARFIELD...MCCONE...PETROLEUM. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1030 PM CDT SUN APR 27 2014 .SYNOPSIS... ISSUED AT 407 PM CDT SUN APR 27 2014 A POTENT...UPPER LEVEL LOW WAS CENTERED OVER WESTERN KS THIS AFTERNOON. A NICE JET STREAK EXTENDED FROM NORTHERN CALIFORNIA...AROUND THE BASE OF THE LOW...NOSING INTO CENTRAL KS. DOWNSTREAM OF THE TROUGH...A HIGH AMPLITUDE...NEGATIVE TILTED RIDGE EXTENDED FROM THE SERN STATES INTO NRN MANITOBA. AT THE SURFACE...LOW PRESSURE WAS NOTED OVER GOODLAND KS WITH A COLD FRONT EXTENDING SSW INTO NERN NEW MEXICO. AN INVERTED TROUGH AXIS EXTENDED NORTH OF THE LOW ALONG THE COLORADO/KS BORDER INTO THE NEBRASKA PANHANDLE. WEST OF THIS INVERTED TROUGH...TEMPS WERE IN THE LOWER TO MID 40S...WHILE EAST OF THE TROUGH AXIS...TEMPS WERE IN THE 60S AND 70S. A DRY LINE...EXTENDED NORTH OF THE SURFACE LOW INTO SWRN NEBRASKA...WHERE IT TURNED SOUTHEAST INTO SOUTH CENTRAL NEBRASKA. THUNDERSTORMS HAVE FIRED ALONG THE DRYLINE THIS AFTERNOON WITH THE TORNADIC THREAT GENERALLY IN SOUTH CENTRAL NEBRASKA WHERE BETTER DIRECTIONAL SHEAR EXISTS. FURTHER NORTH ACROSS THE CENTRAL AND NORTHERN SANDHILLS...GOOD SPEED SHEAR EXISTS...HOWEVER DIRECTIONAL SHEAR IS LACKING PER LATEST KLNX VAD WIND PROFILER. IN THESE AREAS...STRONG TO SEVERE STORMS HAVE OCCURRED WITH LARGE HAIL BEING THE MAIN SEVERE THREAT. && .UPDATE... ISSUED AT 1027 PM CDT SUN APR 27 2014 THE HIGH WIND WATCH HAS BEEN UPGRADED TO A HIGH WIND WARNING BASED ON THE RAP AND 00Z NAM MODEL RUNS WHICH KEEP THE STRONGEST WINDS ALONG HIGHWAY 61. THE AREA TO WATCH IS THE CENTRAL SANDHILLS WHERE THE RAP AND NAM SHOW VERY STRONG 500M AGL WINDS APPROACHING 40 MPH AT THE SFC MONDAY AFTERNOON. NOTE THE FORECAST CONTINUES STRONG OR HIGH WINDS MONDAY NIGHT AND TUESDAY WHICH WOULD NECESSITATE EXTENSIONS OF THE ON GOING HIGH LIGHTS. UPDATE ISSUED AT 837 PM CDT SUN APR 27 2014 A LOOK AT THE NEBRASKA DOR CAMS AND THE RAP MODEL SUGGEST WINTER WEATHER ADVISORY CONDITIONS ACROSS SHERIDAN AND WESTERN CHERRY COUNTIES. THE RAP INDICATES SEVERAL INCHES OF WET SNOW THIS EVENING WHICH TAPERS OFF OR MIXES WITH RAIN AFTER MIDNIGHT. RADAR INDICATES A DEFORMATION ZONE UNDERWAY ACROSS THIS AREA BUT MAINLY ACROSS NRN SHERIDAN COUNTY. A WINTER ADVISORY IS IN PLACE FOR THESE AREA AND IT OPERATES UNTIL 13Z. THE FORECAST UPDATE FOLLOWS 50 PERCENT OF THE 23Z RAP AND 50 PERCENT OF THE PREVIOUS FORECAST. THE PTYPE USES THE RAP MODEL WHICH SPREADS WET SNOW AS FAR SOUTH AS DEUEL COUNTY BUT LITTLE ACCUMULATION IS EXPECTED THAT FAR SOUTH. IT LOOKS LIKE THE FAVORED AREA FOR SNOW IS NORTHWEST NEBRASKA...NORTH OF THE NORTH PLATTE VALLEY FOLLOWING THE H750 MB FRONT WHICH IS STRONGLY STACKED AND MOVING VERY SLOWLY EAST TONIGHT. NOTE THE 23Z RAP PRODUCES OVER 1 INCH OF QPF ACROSS SHERIDAN COUNTY TONIGHT. THE FORECAST USES A RATIO OF 6 TO 1 FOR 3 TO NEARLY 8 INCHES OF SNOW FAVORING PINE RIDGE. && .SHORT TERM...(THIS EVENING THROUGH TONIGHT) ISSUED AT 407 PM CDT SUN APR 27 2014 FORECAST CONCERNS CONTINUE WITH THUNDERSTORM CHANCES TONIGHT...THEN LEAD TO FORMATION OF DEFORMATION BAND AND SNOW POTENTIAL. THE UPPER LOW WAS CENTERED OVER NORTHWEST KANSAS AS OF 20Z...WITH THE SURFACE CIRCULATION ALMOST DIRECTLY OVER KCBK. WITH THE SYSTEM BEING NEARLY VERTICALLY STACKED OVER NORTHWEST KANSAS THIS AFTERNOON...THERE IS CONCERN THAT THE MODELS MAY BE TRYING TO KICK THE SYSTEM EAST TOO QUICKLY THIS EVENING AND OVERNIGHT. THIS WILL IMPACT THE AREAS THAT CONTINUE TO SEE CONVECTION...WHERE THE PRECIPITATION FALLS...WHERE THE WINDS STRENGTHEN...AND WHERE AND WHEN THE RAIN SWITCHES OVER TO SNOW. THE LATEST RAP MODEL MOVES THE SURFACE CIRCULATION TO NEAR KMCK BY 00Z THIS EVENING THEN OVER KHSI AT 06Z AND THEN MOVES IT UP TO AROUND KBVN BY 12Z. THIS SOLUTION IS QUITE SIMILAR TO THE NEW 18Z NAM. THESE SOLUTIONS CONTINUE TO TRANSPORT MOISTURE AROUND THE CIRCULATION AND ACROSS WESTERN AND CENTRAL NEBRASKA THROUGH THE OVERNIGHT HOURS. STRONG FRONTOGENESIS SETS UP ON THE BACK SIDE OF THE SYSTEM...CENTERED OVER THE PANHANDLE AND WESTERN SANDHILLS OVERNIGHT. WITH GOOD MOISTURE IN THAT AREA AND SUBSTANTIAL LIFT DUE TO THE LARGE SCALE FORCING AND FRONTOGENESIS...EXPECT A GOOD DEFORMATION BAND TO BE ONGOING THROUGH MUCH OF THE NIGHT. SOME AREAS COULD SEE UP TO AN INCH OF MOISTURE BY 12Z MONDAY MORNING. THE BIG QUESTION WITH THE PRECIPITATION IS IF ENOUGH COLD AIR WILL MOVE IN TO GET SOME AREAS TO GET A CHANGEOVER TO SNOW. THE NAM AND THE RAP BOTH SHOW WET BULB PROFILES BELOW ZERO UNTIL ABOUT 300FT OR LESS ABOVE THE GROUND IN AREAS OVER THE NORTHEAST PANHANDLE...ESPECIALLY THE PINE RIDGE. IF THIS TURNS OUT...MAY SEE LOTS OF SNOW FALLING BUT WILL BE MELTING WHEN HITTING THE SURFACE OR JUST PRIOR. BUT...EVEN ONE DEGREE DIFFERENCE WILL BE ALL THAT IS NEEDED TO CHANGE OVER COMPLETELY TO SNOW AND IF RATES BECOME STRONG ENOUGH...COULD GET DECENT ACCUMULATIONS. AT THIS TIME...WITH THE MODELS ALL KEEPING THE WET BULB TEMPERATURE ABOVE 0C...DID PUT A COMPLETE CHANGEOVER TO SNOW IN THE NORTHWEST ZONES...BUT ONLY HAVE ACCUMULATIONS UP TO 2 INCHES ASSUMING THERE WILL BE SUBSTANTIAL MELTING AT THE SURFACE. THE NEXT QUESTION WILL BE WHAT WILL REMAIN FOR CONVECTION AND THUNDERSTORM CHANCES OVERNIGHT. KEPT AT LEAST A MENTION OF ISOLATED THUNDER IN AREAS ALONG THE INVERTED TROUGH GOING NORTH OF THE SURFACE LOW AS MOISTURE AND SOME WEAK INSTABILITY WILL CONTINUE TO CIRCULATE AROUND THE SYSTEM. MOVING ON TO WINDS...A VERY TIGHT PRESSURE GRADIENT WILL BE SEEN ON THE BACKSIDE OF THE SYSTEM...WHICH SHOULD CAUSE WINDS TO STRENGTHEN ACROSS THE AREA AS THE LOW MOVES EAST TONIGHT. THE ONGOING WIND ADVISORY FOR AREAS MAINLY WEST OF HIGHWAY 83 FOR THE OVERNIGHT PERIODS CONTINUES TO LOOK GOOD AS SUSTAINED WINDS AROUND 30MPH STILL LOOK LIKELY. WITH THE POTENTIAL FOR MODERATE TO HEAVY SNOW AND STRONG WINDS OVER THE NORTHEAST PART OF THE FORECAST AREA TONIGHT...DID CONSIDER A NEED FOR A WINTER WEATHER ADVISORY FOR LATE TONIGHT INTO MONDAY MORNING. AT THIS TIME...DUE TO THE UNCERTAINTY ON THE SWITCHOVER TO SNOW...OPTED TO NOT ISSUE AT THIS TIME AND WILL MONITOR CLOSELY IF HEADLINES ARE NEEDED. .LONG TERM...(MONDAY THROUGH SUNDAY) ISSUED AT 407 PM CDT SUN APR 27 2014 TOMORROW THROUGH WEDNESDAY...MAIN FORECAST CHALLENGES ARE WINDS AND PRECIPITATION CHANCES IN ASSOCIATION WITH A SLOW MOVING UPPER LEVEL LOW...WHICH WILL MIGRATE FROM EASTERN NEBRASKA INTO THE UPPER MISSISSIPPI VALLEY OVER THE NEXT 24 TO 84 HOURS. IN ADDITION TO PRECIPITATION CHANCES...THE THREAT FOR SNOW...PARTICULARLY DURING THE NIGHTTIME HOURS...WILL BE A CONCERN ACROSS NORTHERN NEBRASKA MONDAY NIGHT AND TUESDAY NIGHT. FOR MONDAY...PRECIPITATION CHANCES AND WINDS WILL BE THE MAIN FORECASTING CONCERN. ON MONDAY...THE MAIN UPPER LEVEL LOW WILL MEANDER ACROSS CENTRAL NEBRASKA...DRIFTING INTO EASTERN NEBRASKA BY LATE AFTERNOON. STRONG WINDS WILL DEVELOP ACROSS CENTRAL AND WESTERN PORTIONS OF THE FORECAST AREA MONDAY AS H85 WINDS REACH 40 TO 50 KTS IN THE SOUTHWEST AND SOUTHEASTERN PANHANDLE MONDAY AFTERNOON. WIND SPEEDS DECREASE FAIRLY QUICKLY EAST OF THE HIGHWAY 83 CORRIDOR AND DO NOT REALLY BEGIN TO KICK IN UNTIL MONDAY EVENING. TO AVOID CONFUSION...DECIDED TO HOIST A HIGH WIND WATCH FOR LOCATIONS ROUGHLY WEST OF A LINE FROM HAYES CENTER...TO ARTHUR...TO GARDEN COUNTY. IN THESE AREAS...A WIND ADVISORY WILL LIKELY BE NEEDED TOMORROW...BUT AT THIS TIME...I DO NOT HAVE ENOUGH CONFIDENCE TO ISSUE A HIGH WIND WARNING AND WILL ISSUE A WATCH AND LET THE MIDNIGHT CREW MAKE THE CALL. FURTHER EAST...TO THE HIGHWAY 83 CORRIDOR...NORTHERLY WINDS WILL INCREASE BY MIDDAY AND ARE EXPECTED TO REACH ADVISORY CRITERIA...FROM LINCOLN COUNTY NWD TO WESTERN CHERRY COUNTY AND WILL HOIST A WIND ADVISORY FOR THESE AREAS. IN ADDITION TO WIND...THERE IS STILL A SMALL THREAT FOR ACCUMULATING SNOWS MONDAY MORNING IN THE FAR NORTHWESTERN FORECAST AREA IN THE VICINITY OF THE PINE RIDGE. LIKE YESTERDAY...THE NAM HAS THE COLDEST BOUNDARY LAYER OF THE THREE MID RANGE MODELS. GIVEN THE LACK OF COLD UPSTREAM AIR ACROSS NERN WYOMING AND WESTERN SOUTH DAKOTA ATTM...AM INCLINED TO TREND TEMPS TOWARD THE WARMER GFS AND ECMWF SOLNS. WITH THIS IN MIND...HAVE WORDED THE FORECAST WITH A RAIN SNOW MIX THROUGH MID MORNING WITH LITTLE OR NO SNOW ACCUMS EXPECTED. WILL CONTINUE TO MONITOR THIS AREA CLOSELY. AS THE DAY PROGRESSES...WIDESPREAD RAIN WILL CONTINUE...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE FORECAST AREA...WHERE A STRONG MID LEVEL DEFORMATION ZONE WILL SET UP AND PERSISTENT ISENTROPIC LIFT CONTINUES THROUGH THE AFTERNOON HOURS. ON MONDAY NIGHT...WINDS WILL INCREASE IN THE EAST AND SUBSIDE SOME IN THE WEST AS THE UPPER LEVEL LOW MEANDERS INTO SWRN IOWA AND NORTHWEST MISSOURI. WINDS WILL REMAIN ON THE GUSTY SIDE INTO THE OVERNIGHT HOURS...WHICH MAY NECESSITATE ISSUANCE OF A WIND ADVISORY MONDAY NIGHT. BASED ON THE LATEST MAV GUIDANCE AND BUFKIT DATA...ALMOST THE ENTIRE FORECAST AREA MAY NEED A WIND ADVISORY FOR MONDAY NIGHT. GIVEN THE ONGOING WIND HEADLINES...WILL HOLD OFF ON ISSUANCE ATTM TO AVOID CONFUSION WITH OUR CURRENT HEADLINES. DECENT ISENTROPIC LIFT CONTINUES INTO TUESDAY MORNING...ESPECIALLY OVER CENTRAL AND NORTHERN NEBRASKA AND WILL CONTINUE LIKELY TO CATEGORICAL POPS OVERNIGHT. TUESDAY THROUGH WEDNESDAY...THE UPPER LEVEL LOW WILL MEANDER EAST ON TUESDAY INTO WEDNESDAY...ENDING UP OVER THE WESTERN GREAT LAKES BY THURSDAY MORNING. DURING THE PERIOD...THE THREAT FOR LIGHT RAIN WILL CONTINUE TUESDAY WITH GUSTY WINDS EXPECTED AS WELL. H85 WINDS WILL DECREASE TO 35 TO 45 KTS ON TUESDAY...SO ANOTHER MAY BE NEEDED FOR TUESDAY ACROSS MOST OF THE FORECAST AREA. TEMPS WILL REMAIN COOL HOWEVER WITH MOSTLY CLOUDY SKIES AND WITH H85 TEMPS RANGING FROM -2C IN THE NORTHEAST...TO 3 C IN THE SOUTHWEST...HIGHS TUESDAY WILL STRUGGLE TO GET OUT OF THE UPPER 30S TO 40S. ON WEDNESDAY...H85 TEMPS WILL WARM TO 1C IN THE NORTHEAST...TO 5C IN THE SOUTHWEST. AFTERNOON HIGHS WILL REBOUND SLIGHTLY TO THE 40S TO LOWER 50S. WINDS WILL BE SOMEWHAT LIGHTER...THOUGH WINDY WITH WIND SPEEDS OF 20 TO 30 MPH...WITH SOME HIGHER GUSTS TO 40 MPH. AT THIS TIME...AM NOT ANTICIPATING ANY WIND HEADLINES ATTM. WEDNESDAY NIGHT AND BEYOND...THE UPPER LEVEL LOW WILL BE ABSORBED BY THE NORTHERN STREAM AND LIFTED EAST TOWARD THE END OF THE WEEK. HOWEVER...LOW PRESSURE ALOFT WILL REMAIN ANCHORED OVER SOUTH CENTRAL CANADA...AND WILL FORCE COLD AIR INTO THE NORTHERN PLAINS LATE IN THE WEEK INTO THE WEEKEND. MAINLY DRY CONDITIONS ARE EXPECTED WITH THIS FLOW REGIME. HIGHS WILL BE MORE MARCH LIKE WITH READINGS IN THE 50S EXPECTED FRIDAY...SATURDAY AND SUNDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 643 PM CDT SUN APR 27 2014 WIDESPREAD MVFR/IFR IN RAIN AND SNOW IS EXPECTED TONIGHT THROUGH MONDAY AFTERNOON AS A SLOW MOVING STORM TRACKS THROUGH THE CENTRAL PLAINS. WINDS 32035G45KT SHOULD SPREAD FROM WEST TO EAST TONIGHT AND CONTINUE THROUGH MONDAY AFTN. && .LBF WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FROM 7 AM CDT /6 AM MDT/ TO 7 PM CDT /6 PM MDT/ MONDAY FOR NEZ022-035-056>058-069-070. WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NEZ022-035- 056>058-069-070. WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ MONDAY FOR NEZ004- 023>025-036-037-059-071-094. WINTER WEATHER ADVISORY UNTIL 7 AM MDT MONDAY FOR NEZ004-094. WIND ADVISORY FROM 7 AM TO 7 PM CDT MONDAY FOR NEZ005-006-008- 009-026-027-038. && $$ UPDATE...CDC SYNOPSIS...CLB SHORT TERM...BROOKS LONG TERM...CLB AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
839 PM CDT SUN APR 27 2014 .SYNOPSIS... ISSUED AT 407 PM CDT SUN APR 27 2014 A POTENT...UPPER LEVEL LOW WAS CENTERED OVER WESTERN KS THIS AFTERNOON. A NICE JET STREAK EXTENDED FROM NORTHERN CALIFORNIA...AROUND THE BASE OF THE LOW...NOSING INTO CENTRAL KS. DOWNSTREAM OF THE TROUGH...A HIGH AMPLITUDE...NEGATIVE TILTED RIDGE EXTENDED FROM THE SERN STATES INTO NRN MANITOBA. AT THE SURFACE...LOW PRESSURE WAS NOTED OVER GOODLAND KS WITH A COLD FRONT EXTENDING SSW INTO NERN NEW MEXICO. AN INVERTED TROUGH AXIS EXTENDED NORTH OF THE LOW ALONG THE COLORADO/KS BORDER INTO THE NEBRASKA PANHANDLE. WEST OF THIS INVERTED TROUGH...TEMPS WERE IN THE LOWER TO MID 40S...WHILE EAST OF THE TROUGH AXIS...TEMPS WERE IN THE 60S AND 70S. A DRY LINE...EXTENDED NORTH OF THE SURFACE LOW INTO SWRN NEBRASKA...WHERE IT TURNED SOUTHEAST INOT SOUTH CENTRAL NEBRASKA. THUNDERSTORMS HAVE FIRED ALONG THE DRYLINE THIS AFTERNOON WITH THE TORNADIC THREAT GENERALLY IN SOUTH CENTRAL NEBRASKA WHERE BETTER DIRECTIONAL SHEAR EXISTS. FURTHER NORTH ACROSS THE CENTRAL AND NORTHERN SANDHILLS...GOOD SPEED SHEAR EXISTS...HOWEVER DIRECTIONAL SHEAR IS LACKING PER LATEST KLNX VAD WIND PROFILER. IN THESE AREAS...STRONG TO SEVERE STORMS HAVE OCCURRED WITH LARGE HAIL BEING THE MAIN SEVERE THREAT. && .UPDATE... ISSUED AT 837 PM CDT SUN APR 27 2014 A LOOK AT THE NEBRASKA DOR CAMS AND THE RAP MODEL SUGGEST WINTER WEATHER ADVISORY CONDITIONS ACROSS SHERIDAN AND WESTERN CHERRY COUNTIES. THE RAP INDICATES SEVERAL INCHES OF WET SNOW THIS EVENING WHICH TAPERS OFF OR MIXES WITH RAIN AFTER MIDNIGHT. RADAR INDICATES A DEFORMATION ZONE UNDERWAY ACROSS THIS AREA BUT MAINLY ACROSS NRN SHERIDAN COUNTY. A WINTER ADVISORY IS IN PLACE FOR THESE AREA AND IT OPERATES UNTIL 13Z. THE FORECAST UPDATE FOLLOWS 50 PERCENT OF THE 23Z RAP AND 50 PERCENT OF THE PREVIOUS FORECAST. THE PTYPE USES THE RAP MODEL WHICH SPREADS WET SNOW AS FAR SOUTH AS DEUEL COUNTY BUT LITTLE ACCUMULATION IS EXPECTED THAT FAR SOUTH. IT LOOKS LIKE THE FAVORED AREA FOR SNOW IS NORTHWEST NEBRASKA...NORTH OF THE NORTH PLATTE VALLEY FOLLOWING THE H750 MB FRONT WHICH IS STRONGLY STACKED AND MOVING VERY SLOWLY EAST TONIGHT. NOTE THE 23Z RAP PRODUCES OVER 1 INCH OF QPF ACROSS SHERIDAN COUNTY TONIGHT. THE FORECAST USES A RATIO OF 6 TO 1 FOR 3 TO NEARLY 8 INCHES OF SNOW FAVORING PINE RIDGE. && .SHORT TERM...(THIS EVENING THROUGH TONIGHT) ISSUED AT 407 PM CDT SUN APR 27 2014 FORECAST CONCERNS CONTINUE WITH THUNDERSTORM CHANCES TONIGHT...THEN LEAD TO FORMATION OF DEFORMATION BAND AND SNOW POTENTIAL. THE UPPER LOW WAS CENTERED OVER NORTHWEST KANSAS AS OF 20Z...WITH THE SURFACE CIRCULATION ALMOST DIRECTLY OVER KCBK. WITH THE SYSTEM BEING NEARLY VERTICALLY STACKED OVER NORTHWEST KANSAS THIS AFTERNOON...THERE IS CONCERN THAT THE MODELS MAY BE TRYING TO KICK THE SYSTEM EAST TOO QUICKLY THIS EVENING AND OVERNIGHT. THIS WILL IMPACT THE AREAS THAT CONTINUE TO SEE CONVECTION...WHERE THE PRECIPITATION FALLS...WHERE THE WINDS STRENGTHEN...AND WHERE AND WHEN THE RAIN SWITCHES OVER TO SNOW. THE LATEST RAP MODEL MOVES THE SURFACE CIRCULATION TO NEAR KMCK BY 00Z THIS EVENING THEN OVER KHSI AT 06Z AND THEN MOVES IT UP TO AROUND KBVN BY 12Z. THIS SOLUTION IS QUITE SIMILAR TO THE NEW 18Z NAM. THESE SOLUTIONS CONTINUE TO TRANSPORT MOISTURE AROUND THE CIRCULATION AND ACROSS WESTERN AND CENTRAL NEBRASKA THROUGH THE OVERNIGHT HOURS. STRONG FRONTOGENESIS SETS UP ON THE BACK SIDE OF THE SYSTEM...CENTERED OVER THE PANHANDLE AND WESTERN SANDHILLS OVERNIGHT. WITH GOOD MOISTURE IN THAT AREA AND SUBSTANTIAL LIFT DUE TO THE LARGE SCALE FORCING AND FRONTOGENESIS...EXPECT A GOOD DEFORMATION BAND TO BE ONGOING THROUGH MUCH OF THE NIGHT. SOME AREAS COULD SEE UP TO AN INCH OF MOISTURE BY 12Z MONDAY MORNING. THE BIG QUESTION WITH THE PRECIPITATION IS IF ENOUGH COLD AIR WILL MOVE IN TO GET SOME AREAS TO GET A CHANGEOVER TO SNOW. THE NAM AND THE RAP BOTH SHOW WET BULB PROFILES BELOW ZERO UNTIL ABOUT 300FT OR LESS ABOVE THE GROUND IN AREAS OVER THE NORTHEAST PANHANDLE...ESPECIALLY THE PINE RIDGE. IF THIS TURNS OUT...MAY SEE LOTS OF SNOW FALLING BUT WILL BE MELTING WHEN HITTING THE SURFACE OR JUST PRIOR. BUT...EVEN ONE DEGREE DIFFERENCE WILL BE ALL THAT IS NEEDED TO CHANGE OVER COMPLETELY TO SNOW AND IF RATES BECOME STRONG ENOUGH...COULD GET DECENT ACCUMULATIONS. AT THIS TIME...WITH THE MODELS ALL KEEPING THE WET BULB TEMPERATURE ABOVE 0C...DID PUT A COMPLETE CHANGEOVER TO SNOW IN THE NORTHWEST ZONES...BUT ONLY HAVE ACCUMULATIONS UP TO 2 INCHES ASSUMING THERE WILL BE SUBSTANTIAL MELTING AT THE SURFACE. THE NEXT QUESTION WILL BE WHAT WILL REMAIN FOR CONVECTION AND THUNDERSTORM CHANCES OVERNIGHT. KEPT AT LEAST A MENTION OF ISOLATED THUNDER IN AREAS ALONG THE INVERTED TROUGH GOING NORTH OF THE SURFACE LOW AS MOISTURE AND SOME WEAK INSTABILITY WILL CONTINUE TO CIRCULATE AROUND THE SYSTEM. MOVING ON TO WINDS...A VERY TIGHT PRESSURE GRADIENT WILL BE SEEN ON THE BACKSIDE OF THE SYSTEM...WHICH SHOULD CAUSE WINDS TO STRENGTHEN ACROSS THE AREA AS THE LOW MOVES EAST TONIGHT. THE ONGOING WIND ADVISORY FOR AREAS MAINLY WEST OF HIGHWAY 83 FOR THE OVERNIGHT PERIODS CONTINUES TO LOOK GOOD AS SUSTAINED WINDS AROUND 30MPH STILL LOOK LIKELY. WITH THE POTENTIAL FOR MODERATE TO HEAVY SNOW AND STRONG WINDS OVER THE NORTHEAST PART OF THE FORECAST AREA TONIGHT...DID CONSIDER A NEED FOR A WINTER WEATHER ADVISORY FOR LATE TONIGHT INTO MONDAY MORNING. AT THIS TIME...DUE TO THE UNCERTAINTY ON THE SWITCHOVER TO SNOW...OPTED TO NOT ISSUE AT THIS TIME AND WILL MONITOR CLOSELY IF HEADLINES ARE NEEDED. .LONG TERM...(MONDAY THROUGH SUNDAY) ISSUED AT 407 PM CDT SUN APR 27 2014 TOMORROW THROUGH WEDNESDAY...MAIN FORECAST CHALLENGES ARE WINDS AND PRECIPITATION CHANCES IN ASSOCIATION WITH A SLOW MOVING UPPER LEVEL LOW...WHICH WILL MIGRATE FROM EASTERN NEBRASKA INTO THE UPPER MISSISSIPPI VALLEY OVER THE NEXT 24 TO 84 HOURS. IN ADDITION TO PRECIPITATION CHANCES...THE THREAT FOR SNOW...PARTICULARLY DURING THE NIGHTTIME HOURS...WILL BE A CONCERN ACROSS NORTHERN NEBRASKA MONDAY NIGHT AND TUESDAY NIGHT. FOR MONDAY...PRECIPITATION CHANCES AND WINDS WILL BE THE MAIN FORECASTING CONCERN. ON MONDAY...THE MAIN UPPER LEVEL LOW WILL MEANDER ACROSS CENTRAL NEBRASKA...DRIFTING INTO EASTERN NEBRASKA BY LATE AFTERNOON. STRONG WINDS WILL DEVELOP ACROSS CENTRAL AND WESTERN PORTIONS OF THE FORECAST AREA MONDAY AS H85 WINDS REACH 40 TO 50 KTS IN THE SOUTHWEST AND SOUTHEASTERN PANHANDLE MONDAY AFTERNOON. WIND SPEEDS DECREASE FAIRLY QUICKLY EAST OF THE HIGHWAY 83 CORRIDOR AND DO NOT REALLY BEGIN TO KICK IN UNTIL MONDAY EVENING. TO AVOID CONFUSION...DECIDED TO HOIST A HIGH WIND WATCH FOR LOCATIONS ROUGHLY WEST OF A LINE FROM HAYES CENTER...TO ARTHUR...TO GARDEN COUNTY. IN THESE AREAS...A WIND ADVISORY WILL LIKELY BE NEEDED TOMORROW...BUT AT THIS TIME...I DO NOT HAVE ENOUGH CONFIDENCE TO ISSUE A HIGH WIND WARNING AND WILL ISSUE A WATCH AND LET THE MIDNIGHT CREW MAKE THE CALL. FURTHER EAST...TO THE HIGHWAY 83 CORRIDOR...NORTHERLY WINDS WILL INCREASE BY MIDDAY AND ARE EXPECTED TO REACH ADVISORY CRITERIA...FROM LINCOLN COUNTY NWD TO WESTERN CHERRY COUNTY AND WILL HOIST A WIND ADVISORY FOR THESE AREAS. IN ADDITION TO WIND...THERE IS STILL A SMALL THREAT FOR ACCUMULATING SNOWS MONDAY MORNING IN THE FAR NORTHWESTERN FORECAST AREA IN THE VICINITY OF THE PINE RIDGE. LIKE YESTERDAY...THE NAM HAS THE COLDEST BOUNDARY LAYER OF THE THREE MID RANGE MODELS. GIVEN THE LACK OF COLD UPSTREAM AIR ACROSS NERN WYOMING AND WESTERN SOUTH DAKOTA ATTM...AM INCLINED TO TREND TEMPS TOWARD THE WARMER GFS AND ECMWF SOLNS. WITH THIS IN MIND...HAVE WORDED THE FORECAST WITH A RAIN SNOW MIX THROUGH MID MORNING WITH LITTLE OR NO SNOW ACCUMS EXPECTED. WILL CONTINUE TO MONITOR THIS AREA CLOSELY. AS THE DAY PROGRESSES...WIDESPREAD RAIN WILL CONTINUE...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE FORECAST AREA...WHERE A STRONG MID LEVEL DEFORMATION ZONE WILL SET UP AND PERSISTENT ISENTROPIC LIFT CONTINUES THROUGH THE AFTERNOON HOURS. ON MONDAY NIGHT...WINDS WILL INCREASE IN THE EAST AND SUBSIDE SOME IN THE WEST AS THE UPPER LEVEL LOW MEANDERS INTO SWRN IOWA AND NORTHWEST MISSOURI. WINDS WILL REMAIN ON THE GUSTY SIDE INTO THE OVERNIGHT HOURS...WHICH MAY NECESSITATE ISSUANCE OF A WIND ADVISORY MONDAY NIGHT. BASED ON THE LATEST MAV GUIDANCE AND BUFKIT DATA...ALMOST THE ENTIRE FORECAST AREA MAY NEED A WIND ADVISORY FOR MONDAY NIGHT. GIVEN THE ONGOING WIND HEADLINES...WILL HOLD OFF ON ISSUANCE ATTM TO AVOID CONFUSION WITH OUR CURRENT HEADLINES. DECENT ISENTROPIC LIFT CONTINUES INTO TUESDAY MORNING...ESPECIALLY OVER CENTRAL AND NORTHERN NEBRASKA AND WILL CONTINUE LIKELY TO CATEGORICAL POPS OVERNIGHT. TUESDAY THROUGH WEDNESDAY...THE UPPER LEVEL LOW WILL MEANDER EAST ON TUESDAY INTO WEDNESDAY...ENDING UP OVER THE WESTERN GREAT LAKES BY THURSDAY MORNING. DURING THE PERIOD...THE THREAT FOR LIGHT RAIN WILL CONTINUE TUESDAY WITH GUSTY WINDS EXPECTED AS WELL. H85 WINDS WILL DECREASE TO 35 TO 45 KTS ON TUESDAY...SO ANOTHER MAY BE NEEDED FOR TUESDAY ACROSS MOST OF THE FORECAST AREA. TEMPS WILL REMAIN COOL HOWEVER WITH MOSTLY CLOUDY SKIES AND WITH H85 TEMPS RANGING FROM -2C IN THE NORTHEAST...TO 3 C IN THE SOUTHWEST...HIGHS TUESDAY WILL STRUGGLE TO GET OUT OF THE UPPER 30S TO 40S. ON WEDNESDAY...H85 TEMPS WILL WARM TO 1C IN THE NORTHEAST...TO 5C IN THE SOUTHWEST. AFTERNOON HIGHS WILL REBOUND SLIGHTLY TO THE 40S TO LOWER 50S. WINDS WILL BE SOMEWHAT LIGHTER...THOUGH WINDY WITH WIND SPEEDS OF 20 TO 30 MPH...WITH SOME HIGHER GUSTS TO 40 MPH. AT THIS TIME...AM NOT ANTICIPATING ANY WIND HEADLINES ATTM. WEDNESDAY NIGHT AND BEYOND...THE UPPER LEVEL LOW WILL BE ABSORBED BY THE NORTHERN STREAM AND LIFTED EAST TOWARD THE END OF THE WEEK. HOWEVER...LOW PRESSURE ALOFT WILL REMAIN ANCHORED OVER SOUTH CENTRAL CANADA...AND WILL FORCE COLD AIR INTO THE NORTHERN PLAINS LATE IN THE WEEK INTO THE WEEKEND. MAINLY DRY CONDITIONS ARE EXPECTED WITH THIS FLOW REGIME. HIGHS WILL BE MORE MARCH LIKE WITH READINGS IN THE 50S EXPECTED FRIDAY...SATURDAY AND SUNDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 643 PM CDT SUN APR 27 2014 WIDESPREAD MVFR/IFR IN RAIN AND SNOW IS EXPECTED TONIGHT THROUGH MONDAY AFTERNOON AS A SLOW MOVING STORM TRACKS THROUGH THE CENTRAL PLAINS. WINDS 32035G45KT SHOULD SPREAD FROM WEST TO EAST TONIGHT AND CONTINUE THROUGH MONDAY AFTN. && .LBF WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NEZ022-035- 056>058-069-070. HIGH WIND WATCH FROM 7 AM CDT /6 AM MDT/ MONDAY THROUGH MONDAY EVENING FOR NEZ022-035-056>058-069-070. WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ MONDAY FOR NEZ004- 023>025-036-037-059-071-094. WINTER WEATHER ADVISORY UNTIL 7 AM MDT MONDAY FOR NEZ004-094. WIND ADVISORY FROM 7 AM TO 7 PM CDT MONDAY FOR NEZ005-006-008- 009-026-027-038. && $$ UPDATE...CDC SYNOPSIS...CLB SHORT TERM...BROOKS LONG TERM...CLB AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
645 PM CDT SUN APR 27 2014 .SYNOPSIS... ISSUED AT 407 PM CDT SUN APR 27 2014 A POTENT...UPPER LEVEL LOW WAS CENTERED OVER WESTERN KS THIS AFTERNOON. A NICE JET STREAK EXTENDED FROM NORTHERN CALIFORNIA...AROUND THE BASE OF THE LOW...NOSING INTO CENTRAL KS. DOWNSTREAM OF THE TROUGH...A HIGH AMPLITUDE...NEGATIVE TILTED RIDGE EXTENDED FROM THE SERN STATES INTO NRN MANITOBA. AT THE SURFACE...LOW PRESSURE WAS NOTED OVER GOODLAND KS WITH A COLD FRONT EXTENDING SSW INTO NERN NEW MEXICO. AN INVERTED TROUGH AXIS EXTENDED NORTH OF THE LOW ALONG THE COLORADO/KS BORDER INTO THE NEBRASKA PANHANDLE. WEST OF THIS INVERTED TROUGH...TEMPS WERE IN THE LOWER TO MID 40S...WHILE EAST OF THE TROUGH AXIS...TEMPS WERE IN THE 60S AND 70S. A DRY LINE...EXTENDED NORTH OF THE SURFACE LOW INTO SWRN NEBRASKA...WHERE IT TURNED SOUTHEAST INOT SOUTH CENTRAL NEBRASKA. THUNDERSTORMS HAVE FIRED ALONG THE DRYLINE THIS AFTERNOON WITH THE TORNADIC THREAT GENERALLY IN SOUTH CENTRAL NEBRASKA WHERE BETTER DIRECTIONAL SHEAR EXISTS. FURTHER NORTH ACROSS THE CENTRAL AND NORTHERN SANDHILLS...GOOD SPEED SHEAR EXISTS...HOWEVER DIRECTIONAL SHEAR IS LACKING PER LATEST KLNX VAD WIND PROFILER. IN THESE AREAS...STRONG TO SEVERE STORMS HAVE OCCURRED WITH LARGE HAIL BEING THE MAIN SEVERE THREAT. && .SHORT TERM...(THIS EVENING THROUGH TONIGHT) ISSUED AT 407 PM CDT SUN APR 27 2014 FORECAST CONCERNS CONTINUE WITH THUNDERSTORM CHANCES TONIGHT...THEN LEAD TO FORMATION OF DEFORMATION BAND AND SNOW POTENTIAL. THE UPPER LOW WAS CENTERED OVER NORTHWEST KANSAS AS OF 20Z...WITH THE SURFACE CIRCULATION ALMOST DIRECTLY OVER KCBK. WITH THE SYSTEM BEING NEARLY VERTICALLY STACKED OVER NORTHWEST KANSAS THIS AFTERNOON...THERE IS CONCERN THAT THE MODELS MAY BE TRYING TO KICK THE SYSTEM EAST TOO QUICKLY THIS EVENING AND OVERNIGHT. THIS WILL IMPACT THE AREAS THAT CONTINUE TO SEE CONVECTION...WHERE THE PRECIPITATION FALLS...WHERE THE WINDS STRENGTHEN...AND WHERE AND WHEN THE RAIN SWITCHES OVER TO SNOW. THE LATEST RAP MODEL MOVES THE SURFACE CIRCULATION TO NEAR KMCK BY 00Z THIS EVENING THEN OVER KHSI AT 06Z AND THEN MOVES IT UP TO AROUND KBVN BY 12Z. THIS SOLUTION IS QUITE SIMILAR TO THE NEW 18Z NAM. THESE SOLUTIONS CONTINUE TO TRANSPORT MOISTURE AROUND THE CIRCULATION AND ACROSS WESTERN AND CENTRAL NEBRASKA THROUGH THE OVERNIGHT HOURS. STRONG FRONTOGENESIS SETS UP ON THE BACK SIDE OF THE SYSTEM...CENTERED OVER THE PANHANDLE AND WESTERN SANDHILLS OVERNIGHT. WITH GOOD MOISTURE IN THAT AREA AND SUBSTANTIAL LIFT DUE TO THE LARGE SCALE FORCING AND FRONTOGENESIS...EXPECT A GOOD DEFORMATION BAND TO BE ONGOING THROUGH MUCH OF THE NIGHT. SOME AREAS COULD SEE UP TO AN INCH OF MOISTURE BY 12Z MONDAY MORNING. THE BIG QUESTION WITH THE PRECIPITATION IS IF ENOUGH COLD AIR WILL MOVE IN TO GET SOME AREAS TO GET A CHANGEOVER TO SNOW. THE NAM AND THE RAP BOTH SHOW WET BULB PROFILES BELOW ZERO UNTIL ABOUT 300FT OR LESS ABOVE THE GROUND IN AREAS OVER THE NORTHEAST PANHANDLE...ESPECIALLY THE PINE RIDGE. IF THIS TURNS OUT...MAY SEE LOTS OF SNOW FALLING BUT WILL BE MELTING WHEN HITTING THE SURFACE OR JUST PRIOR. BUT...EVEN ONE DEGREE DIFFERENCE WILL BE ALL THAT IS NEEDED TO CHANGE OVER COMPLETELY TO SNOW AND IF RATES BECOME STRONG ENOUGH...COULD GET DECENT ACCUMULATIONS. AT THIS TIME...WITH THE MODELS ALL KEEPING THE WET BULB TEMPERATURE ABOVE 0C...DID PUT A COMPLETE CHANGEOVER TO SNOW IN THE NORTHWEST ZONES...BUT ONLY HAVE ACCUMULATIONS UP TO 2 INCHES ASSUMING THERE WILL BE SUBSTANTIAL MELTING AT THE SURFACE. THE NEXT QUESTION WILL BE WHAT WILL REMAIN FOR CONVECTION AND THUNDERSTORM CHANCES OVERNIGHT. KEPT AT LEAST A MENTION OF ISOLATED THUNDER IN AREAS ALONG THE INVERTED TROUGH GOING NORTH OF THE SURFACE LOW AS MOISTURE AND SOME WEAK INSTABILITY WILL CONTINUE TO CIRCULATE AROUND THE SYSTEM. MOVING ON TO WINDS...A VERY TIGHT PRESSURE GRADIENT WILL BE SEEN ON THE BACKSIDE OF THE SYSTEM...WHICH SHOULD CAUSE WINDS TO STRENGTHEN ACROSS THE AREA AS THE LOW MOVES EAST TONIGHT. THE ONGOING WIND ADVISORY FOR AREAS MAINLY WEST OF HIGHWAY 83 FOR THE OVERNIGHT PERIODS CONTINUES TO LOOK GOOD AS SUSTAINED WINDS AROUND 30MPH STILL LOOK LIKELY. WITH THE POTENTIAL FOR MODERATE TO HEAVY SNOW AND STRONG WINDS OVER THE NORTHEAST PART OF THE FORECAST AREA TONIGHT...DID CONSIDER A NEED FOR A WINTER WEATHER ADVISORY FOR LATE TONIGHT INTO MONDAY MORNING. AT THIS TIME...DUE TO THE UNCERTAINTY ON THE SWITCHOVER TO SNOW...OPTED TO NOT ISSUE AT THIS TIME AND WILL MONITOR CLOSELY IF HEADLINES ARE NEEDED. .LONG TERM...(MONDAY THROUGH SUNDAY) ISSUED AT 407 PM CDT SUN APR 27 2014 TOMORROW THROUGH WEDNESDAY...MAIN FORECAST CHALLENGES ARE WINDS AND PRECIPITATION CHANCES IN ASSOCIATION WITH A SLOW MOVING UPPER LEVEL LOW...WHICH WILL MIGRATE FROM EASTERN NEBRASKA INTO THE UPPER MISSISSIPPI VALLEY OVER THE NEXT 24 TO 84 HOURS. IN ADDITION TO PRECIPITATION CHANCES...THE THREAT FOR SNOW...PARTICULARLY DURING THE NIGHTTIME HOURS...WILL BE A CONCERN ACROSS NORTHERN NEBRASKA MONDAY NIGHT AND TUESDAY NIGHT. FOR MONDAY...PRECIPITATION CHANCES AND WINDS WILL BE THE MAIN FORECASTING CONCERN. ON MONDAY...THE MAIN UPPER LEVEL LOW WILL MEANDER ACROSS CENTRAL NEBRASKA...DRIFTING INTO EASTERN NEBRASKA BY LATE AFTERNOON. STRONG WINDS WILL DEVELOP ACROSS CENTRAL AND WESTERN PORTIONS OF THE FORECAST AREA MONDAY AS H85 WINDS REACH 40 TO 50 KTS IN THE SOUTHWEST AND SOUTHEASTERN PANHANDLE MONDAY AFTERNOON. WIND SPEEDS DECREASE FAIRLY QUICKLY EAST OF THE HIGHWAY 83 CORRIDOR AND DO NOT REALLY BEGIN TO KICK IN UNTIL MONDAY EVENING. TO AVOID CONFUSION...DECIDED TO HOIST A HIGH WIND WATCH FOR LOCATIONS ROUGHLY WEST OF A LINE FROM HAYES CENTER...TO ARTHUR...TO GARDEN COUNTY. IN THESE AREAS...A WIND ADVISORY WILL LIKELY BE NEEDED TOMORROW...BUT AT THIS TIME...I DO NOT HAVE ENOUGH CONFIDENCE TO ISSUE A HIGH WIND WARNING AND WILL ISSUE A WATCH AND LET THE MIDNIGHT CREW MAKE THE CALL. FURTHER EAST...TO THE HIGHWAY 83 CORRIDOR...NORTHERLY WINDS WILL INCREASE BY MIDDAY AND ARE EXPECTED TO REACH ADVISORY CRITERIA...FROM LINCOLN COUNTY NWD TO WESTERN CHERRY COUNTY AND WILL HOIST A WIND ADVISORY FOR THESE AREAS. IN ADDITION TO WIND...THERE IS STILL A SMALL THREAT FOR ACCUMULATING SNOWS MONDAY MORNING IN THE FAR NORTHWESTERN FORECAST AREA IN THE VICINITY OF THE PINE RIDGE. LIKE YESTERDAY...THE NAM HAS THE COLDEST BOUNDARY LAYER OF THE THREE MID RANGE MODELS. GIVEN THE LACK OF COLD UPSTREAM AIR ACROSS NERN WYOMING AND WESTERN SOUTH DAKOTA ATTM...AM INCLINED TO TREND TEMPS TOWARD THE WARMER GFS AND ECMWF SOLNS. WITH THIS IN MIND...HAVE WORDED THE FORECAST WITH A RAIN SNOW MIX THROUGH MID MORNING WITH LITTLE OR NO SNOW ACCUMS EXPECTED. WILL CONTINUE TO MONITOR THIS AREA CLOSELY. AS THE DAY PROGRESSES...WIDESPREAD RAIN WILL CONTINUE...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE FORECAST AREA...WHERE A STRONG MID LEVEL DEFORMATION ZONE WILL SET UP AND PERSISTENT ISENTROPIC LIFT CONTINUES THROUGH THE AFTERNOON HOURS. ON MONDAY NIGHT...WINDS WILL INCREASE IN THE EAST AND SUBSIDE SOME IN THE WEST AS THE UPPER LEVEL LOW MEANDERS INTO SWRN IOWA AND NORTHWEST MISSOURI. WINDS WILL REMAIN ON THE GUSTY SIDE INTO THE OVERNIGHT HOURS...WHICH MAY NECESSITATE ISSUANCE OF A WIND ADVISORY MONDAY NIGHT. BASED ON THE LATEST MAV GUIDANCE AND BUFKIT DATA...ALMOST THE ENTIRE FORECAST AREA MAY NEED A WIND ADVISORY FOR MONDAY NIGHT. GIVEN THE ONGOING WIND HEADLINES...WILL HOLD OFF ON ISSUANCE ATTM TO AVOID CONFUSION WITH OUR CURRENT HEADLINES. DECENT ISENTROPIC LIFT CONTINUES INTO TUESDAY MORNING...ESPECIALLY OVER CENTRAL AND NORTHERN NEBRASKA AND WILL CONTINUE LIKELY TO CATEGORICAL POPS OVERNIGHT. TUESDAY THROUGH WEDNESDAY...THE UPPER LEVEL LOW WILL MEANDER EAST ON TUESDAY INTO WEDNESDAY...ENDING UP OVER THE WESTERN GREAT LAKES BY THURSDAY MORNING. DURING THE PERIOD...THE THREAT FOR LIGHT RAIN WILL CONTINUE TUESDAY WITH GUSTY WINDS EXPECTED AS WELL. H85 WINDS WILL DECREASE TO 35 TO 45 KTS ON TUESDAY...SO ANOTHER MAY BE NEEDED FOR TUESDAY ACROSS MOST OF THE FORECAST AREA. TEMPS WILL REMAIN COOL HOWEVER WITH MOSTLY CLOUDY SKIES AND WITH H85 TEMPS RANGING FROM -2C IN THE NORTHEAST...TO 3 C IN THE SOUTHWEST...HIGHS TUESDAY WILL STRUGGLE TO GET OUT OF THE UPPER 30S TO 40S. ON WEDNESDAY...H85 TEMPS WILL WARM TO 1C IN THE NORTHEAST...TO 5C IN THE SOUTHWEST. AFTERNOON HIGHS WILL REBOUND SLIGHTLY TO THE 40S TO LOWER 50S. WINDS WILL BE SOMEWHAT LIGHTER...THOUGH WINDY WITH WIND SPEEDS OF 20 TO 30 MPH...WITH SOME HIGHER GUSTS TO 40 MPH. AT THIS TIME...AM NOT ANTICIPATING ANY WIND HEADLINES ATTM. WEDNESDAY NIGHT AND BEYOND...THE UPPER LEVEL LOW WILL BE ABSORBED BY THE NORTHERN STREAM AND LIFTED EAST TOWARD THE END OF THE WEEK. HOWEVER...LOW PRESSURE ALOFT WILL REMAIN ANCHORED OVER SOUTH CENTRAL CANADA...AND WILL FORCE COLD AIR INTO THE NORTHERN PLAINS LATE IN THE WEEK INTO THE WEEKEND. MAINLY DRY CONDITIONS ARE EXPECTED WITH THIS FLOW REGIME. HIGHS WILL BE MORE MARCH LIKE WITH READINGS IN THE 50S EXPECTED FRIDAY...SATURDAY AND SUNDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 643 PM CDT SUN APR 27 2014 WIDESPREAD MVFR/IFR IN RAIN AND SNOW IS EXPECTED TONIGHT THROUGH MONDAY AFTERNOON AS A SLOW MOVING STORM TRACKS THROUGH THE CENTRAL PLAINS. WINDS 32035G45KT SHOULD SPREAD FROM WEST TO EAST TONIGHT AND CONTINUE THROUGH MONDAY AFTN. && .LBF WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 6 AM MDT MONDAY FOR NEZ022-035-056>058-069. HIGH WIND WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR NEZ022-035-056>058-069-070. WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ MONDAY FOR NEZ023>025- 036-037-059-071-094. WIND ADVISORY UNTIL 6 PM MDT MONDAY FOR NEZ004. WIND ADVISORY UNTIL 7 AM CDT MONDAY FOR NEZ070. WIND ADVISORY FROM 7 AM TO 7 PM CDT MONDAY FOR NEZ005-006-008- 009-026-027-038. && $$ SYNOPSIS...CLB SHORT TERM...BROOKS LONG TERM...CLB AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
400 PM CDT SAT APR 26 2014 .SYNOPSIS... ISSUED AT 358 PM CDT SAT APR 26 2014 AT 19Z...WATER VAPOR IMAGERY SHOWED A DEEP UPPER LEVEL TROUGH ACROSS THE WESTERN CONUS...WITH A STRONG PV ANOMALY AT THE BASE OF THE TROUGH OVER WESTERN ARIZONA. UPPER LEVEL ANALYSIS FROM 12Z SHOWED 100+KT JET ROUNDING THE BASE OF THE TROUGH. DOWNSTREAM OF THE TROUGH...THE RIDGE AXIS WAS FROM THE LOWER MISSISSIPPI RIVER VALLEY...INTO THE NORTHERN PLAINS AND UP INTO THE WESTERN NORTHWEST TERRITORIES IN CANADA. AT THE SURFACE...LOW PRESSURE WAS OVER NORTHERN COLORADO WITH A WARM FRONT EXTENDING ACROSS NORTHERN KANSAS. SOUTH OF THE WARM FRONT TEMPERATURES HAD WARMED INTO THE UPPER 80S AND LOW 90S ALONG WITH BREEZY SOUTHERLY WINDS AND A GOOD DRYLINE FROM EAST OF KHLC INTO THE OKLAHOMA PANHANDLE. TO THE NORTH OF THE FRONT 70S AND LOW 80S WERE OBSERVED WITH SOUTHEAST WINDS. FURTHER NORTH...A STATIONARY FRONT WAS LOCATED FROM WESTERN SOUTH DAKOTA INTO EAST CENTRAL NEBRASKA WITH A SLIGHT WIND SHIFT BEING DEFINED IN THE SURFACE FIELD. WINDS NORTH OF THE FRONT WERE QUITE STRONG...WITH GUSTS OF 35KTS TO 50KTS ACROSS SOUTH DAKOTA. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 358 PM CDT SAT APR 26 2014 THE UPPER LEVEL TROUGH WILL LIFT INTO SOUTHEAST COLORADO BY 12Z SUNDAY. MEANWHILE...THE WARM FRONT WILL LIFT NORTH THIS EVENING AS THE SURFACE LOW SLOWLY MIGRATES EAST INTO SOUTHWEST NEBRASKA. CURRENTLY...THE AREA IS IN THE DRY SLOT OF THE MID LEVEL FLOW AS CAN BE SEEN FROM WATER VAPOR AS THE FETCH OF DRY AIR COMES ALL THE WAY INTO NEBRASKA FROM THE BASE OF THE TROUGH. THE MAIN AREA OF MOISTURE IS BEING PUSHED INTO KANSAS AND EASTERN NEBRASKA AS CAN BE SEEN BY MID LEVEL CLOUD COVER. THIS DRY AIR WILL KEEP ANY SHOWERS/STORMS FROM DEVELOPING NORTH OF THE WARM FRONT YET THIS AFTERNOON. AS THE FRONT MOVES NORTH THE AREA THIS EVENING...MODELS SHOW THE WARM SECTOR STAYING CAPPED AT LEAST UNTIL 00Z AND MUCH OF THE LOCAL AREA STAYING CAPPED UNTIL AFTER 06Z. THE LATEST HRRR FROM 26.18Z DOES SHOW A FEW STORMS DEVELOPING OVER EASTERN NEBRASKA AROUND 00Z. BUT WITH THE MID LEVEL FLOW...ANYTHING THAT DEVELOPS WILL MOVE QUICKLY NORTHEAST. IF THE FORECAST AREA WILL SEE ANY STORMS TONIGHT...WILL NEED STORMS TO DEVELOP LOCALLY. DIDN/T REMOVE CHANCES COMPLETELY OVERNIGHT...BUT CONFIDENCE IS NOT HIGH ON STORM DEVELOPMENT. IF STORMS WOULD DEVELOP THIS EVENING ALONG THE WARM FRONT...SEVERE PARAMETERS DO INDICATE THERE WOULD BE POTENTIAL FOR A FEW ORGANIZED SUPERCELLS. AND WITH GOOD LOW LEVEL HELICITY...CAN/T COMPLETELY RULE OUT A BRIEF ISOLATED TORNADO. HOWEVER...EVEN THOUGH SOUTHEAST AND EASTERLY WINDS ALONG THE WARM FRONT WILL CONTINUE TO PULL MOISTURE INTO NORTH CENTRAL NEBRASKA THIS EVENING AND OVERNIGHT. HOWEVER...THINK SOME OF THE MODELS MAY BE A BIT ROBUST GETTING MID TO UPPER 50 DEWPOINTS IN THESE AREAS. THE LACK OF LOW LEVEL MOISTURE WOULD VERY LIKELY PROHIBIT ANY STORMS PRODUCING TORNADOS. FOR SUNDAY...THE MODELS ARE FINALLY COMING INTO AGREEMENT ON THE TRACK OF THE SYSTEM AS THEY BRING THE 500MB LOW INTO WESTERN NEBRASKA. THERE DOES REMAIN SOME DIFFERENCES THOUGH IN THE WEST TO EAST EXTENT AND ALTHOUGH IT IS NOT MUCH IT HAS A HIGH IMPACT ON THE WEATHER FOR SUNDAY AND SUNDAY NIGHT. FORECAST CONFIDENCE HAS IMPROVED...YET THERE ARE STILL CONSIDERABLE QUESTIONS. WITH THE SURFACE LOW NOW LOOKING MORE LIKELY TO TRACK JUST NORTH OF THE NEBRASKA-KANSAS BORDER SUNDAY AND CENTERED IN THE KLBF/KMCK AREA AT 00Z PRECIPITATION CHANCES WILL INCREASE THROUGH THE DAY...MAINLY ON THE NORTHERN AND WESTERN PERIPHERIES OF THE LOW. SO DID INCREASE CHANCES ACROSS NORTHERN NEBRASKA AND THE PANHANDLE. ON THE BACK SIDE OF THE LOW...WINDS WILL STRENGTHEN CONSIDERABLY BY LATE AFTERNOON. CURRENT FORECAST FOLLOWS A SLOWER EASTERLY PROGRESSION OF THE SURFACE LOW WHICH KEEPS THE WINDS FROM INCREASING UNTIL AFTER 00Z. HOWEVER QUICKER MOVEMENT COULD MEAN STRONG WINDS OF 30KTS SUSTAINED EARLIER. WILL LET ONE MORE FORECAST CYCLE GO TO ALLOW MODELS TO COME INTO BETTER AGREEMENT BEFORE DECIDING ON ANY HEADLINES FOR WINDS DUE TO SOME UNCERTAINTY. IN TERMS OF THUNDERSTORMS FOR SUNDAY...INSTABILITY ISN/T TERRIBLY HIGH...WITH MUCAPE VALUES OF 100J/KG TO 1500 J/KG...BUT WITH STEEP LOW LEVEL LAPSE RATES AND SUFFICIENT SHEAR CAN/T DISCOUNT ANY STORMS AS WELL AS ANY STORMS BECOMING SEVERE. THE PRIMARY AREAS OF CONCERN WILL BE OVER NORTH CENTRAL NEBRASKA /EAST OF HIGHWAY 183/ WHERE THERE WILL BE MORE MOISTURE. SOMETHING TO CONSIDER WATCHING THROUGH THE DAY WILL BE IF ANY CONVECTION GOES UP ON THE WESTERN EDGE OF THE SURFACE LOW AND THE INVERTED TROUGH ACROSS THE WESTERN SANDHILLS. THERE IS ONLY LOW INSTABILITY BUT WITH LOW LEVEL TURNING IN THE VICINITY OF THE BOUNDARY...COULD CAUSE ANY CONVECTION TO SPIN. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 358 PM CDT SAT APR 26 2014 MID RANGE...SUNDAY NIGHT THROUGH TUESDAY...A PERSISTENT...SLOW MOVING UPPER LEVEL LOW...WILL MEANDER FROM SOUTHWESTERN TO NORTHEASTERN NEBRASKA DURING THE PERIOD...EVENTUALLY MOVING EAST OF THE STATE TUESDAY NIGHT. A PLETHORA OF WEATHER WILL OCCUR ON THE BACK SIDE OF THIS FEATURE AS IT MIGRATES ACROSS WESTERN AND NORTH CENTRAL NEBRASKA SUNDAY NIGHT INTO TUESDAY AND THIS WILL BE THE MAIN FORECASTING CHALLENGE FOR THE BEGINNING OF THE WEEK. SUNDAY NIGHT INTO MONDAY...FOR THESE PERIODS...THE THREAT FOR WINTRY WEATHER IN THE NORTHWEST SUNDAY NIGHT THEN WIND POTENTIAL SUNDAY NIGHT INTO MONDAY ARE THE MAIN FORECAST CONCERNS. SUNDAY NIGHT INTO MONDAY...AN INTENSE UPPER LEVEL LOW AND STRONG SURFACE LOW...WILL MEANDER SLOWLY ACROSS NEBRASKA. ON THE BACK SIDE OF THIS FEATURE SUNDAY NIGHT INTO MONDAY...A NICE DEFORMATION BAND OF PCPN IS EXPECTED TO DEVELOP ALONG WITH STRONG WINDS WHICH WILL TRANSITION FROM WEST TO EAST SUNDAY NIGHT INTO MONDAY. HOW FAR EAST THE STRONG WINDS DEVELOP SUNDAY NIGHT INTO MONDAY IS STILL UP IN THE AIR SOME. MORE ON THAT TWO PARAGRAPHS BELOW. EVEN AT ONLY 36 TO 48 HOURS OUT...THE LATEST NAM...GFS AND ECMWF SOLNS ARE STILL HAVING ISSUES WITH THE TRACK OF THE H5 LOW AND TRACK OF THE SURFACE LOW. THE NAM LIFTS THE H5 LOW FROM AROUND ARNOLD NEBRASKA TO NORTH OF ONEILL NEBRASKA FROM 00Z TO 12Z MONDAY. THE GFS LIFTS THE LOW FROM FAR EASTERN FRONTIER COUNTY TO NEAR SPRINGVIEW NEBRASKA DURING THE SAME PERIOD...WHILE THE ECMWF LIFTS THE LOW FROM WESTERN LINCOLN COUNTY TO NEAR VALENTINE. NO SURPRISE...THE NAM IS COLDEST AT H85 WITH SUB FREEZING TEMPS IN THE NORTHWESTERN FORECAST AREA OVERNIGHT SUNDAY NIGHT...WHICH WOULD FAVOR SNOW FOR PRECIPITATION TYPE. THE GFS AND ECMWF ARE CONSIDERABLY WARMER WITH H85 TEMPS OF 2 TO 3 C AT 12Z MONDAY MORNING...FAVORING ALL RAIN OR POSSIBLE RAIN SNOW MIX. ATTM...WILL GO WITH A RAIN/SNOW MIX FOR PTYPE OVERNIGHT SUNDAY NIGHT IN THE FAR NORTHWEST GIVEN THE TRACK DIFFERENCES IN THE UPPER LEVEL SYSTEM. ATTM...WITH TEMPERATURES HOVERING IN THE MIDDLE 30S SUNDAY NIGHT IN THE FAR NORTHWEST...NOT EXPECTING ANY ACCUMS ATTM. THEN THERE IS THE WIND THREAT ON THE BACK SIDE OF THE EXITING SYSTEM. FOR SUNDAY NIGHT...THE ECMWF AND GFS SOLNS ARE IN GENERAL AGREEMENT WITH LOCATION OF THE SURFACE LOW AT 12Z MONDAY...IE OVER THE FAR NERN CWA...WHILE THE NAM12 HAS THE LOW NEAR SIOUX CITY IOWA. NO SURPRISE...THERE ARE SIGNIFICANT DIFFERENCES IN WIND SPEEDS BETWEEN THE MET AND MAV GUIDANCE FOR SUNDAY NIGHT. IF THE MET VERIFIES...WE WOULD PROBABLY NEED SOME SORT OF WIND HEADLINE FOR AT LEAST THE WESTERN HALF OF THE FORECAST AREA SUNDAY NIGHT. WITH THE GFS SOLN...ANY WIND ADVISORY IF NEEDED WOULD BE CONFINED TO THE FAR SOUTHWESTERN AND EASTERN PANHANDLE COUNTIES. THIS LEADS TO THE HEADLINE DILEMMA FOR SUNDAY NIGHT...WINTER HEADLINES IN THE NERN PANHANDLE OR WIND HEADLINES. GIVEN THE DISCREPANCIES IN THE LOCATION OF THE SURFACE LOW AND UPPER LEVEL LOW...WILL HOLD OFF ON HEADLINES FOR SUNDAY NIGHT AND WAIT FOR ANOTHER MODEL RUN TO COME IN. ON MONDAY...THE SURFACE LOW WILL MIGRATE EAST OF THE UPPER LEVEL LOW INTO EASTERN NEBRASKA. AT THE SAME TIME...A DOWNSTREAM BLOCKING RIDGE WILL LIMIT ANY EWD MOVEMENT OF THE H5 LOW...WHICH WILL REMAIN IN PLACE ACROSS CENTRAL NEBRASKA. WRAP AROUND PCPN WILL CONTINUE PARTICULARLY OVER NORTH CENTRAL AND NORTHWESTERN NEBRASKA AS FAVORABLE ISENTROPIC LIFT CONTINUES. IN ADDITION TO COLD RAIN...VERY WINDY CONDITIONS WILL DEVELOP ESPECIALLY ACROSS THE WESTERN 2/3RDS OF THE FORECAST AREA. AGAIN...LIKE SUNDAY NIGHT...WIND SPEEDS WILL BE HIGHLY DEPENDENT ON WHERE THE SURFACE LOW SETS UP ON MONDAY AFTERNOON. BETTER CONFIDENCE EXISTS IN THE WIND FORECAST FOR MONDAY AS THE MODELS HAVE THE SURFACE LOW OVER NERN NEBRASKA BY 00Z TUESDAY. MONDAY NIGHT AND TUESDAY...FROM MONDAY NIGHT INTO TUESDAY AFTERNOON...THE UPPER LEVEL LOW WILL CRAWL SLOWLY EAST INTO THE MID MISSISSIPPI VALLEY. ON MONDAY NIGHT...A STRONG SHORTWAVE WILL ROTATE AROUND THE WESTERN PERIPHERY OF THE CLOSED LOW BRINGING ANOTHER SHOT OF RAIN AND OR SNOW SHOWERS TO THE FORECAST AREA. THE LATEST ECMWF AND GFS SOLNS ARE INDICATING ENOUGH COLD AIR FOR AT LEAST A RAIN SNOW MIX OVERNIGHT MONDAY NIGHT INTO TUESDAY MORNING ACROSS PORTIONS OF NORTH CENTRAL NEBRASKA AND WILL INSERT THIS IN THE UPDATED FORECAST. WINDS WILL BE AN ISSUE ONCE AGAIN ON TUESDAY 40+ KT H85 WINDS WILL BE PRESENT ACROSS WESTERN AND NORTH CENTRAL NEBRASKA. TEMPERATURES TUESDAY WILL BE COOLER AS WELL AND IS SHAPING UP TO BE THE COOLEST DAY OF THE PERIOD ACROSS WESTERN AND NORTH CENTRAL NEBRASKA AS H85 TEMPS DROP DOWN TO -2C TO 5C. ACROSS NORTH CENTRAL NEBRASKA...TEMPERATURES WILL BE COOL ENOUGH TO FACILITATE AT LEAST A RAIN SNOW MIX TROUGH THE MORNING HOURS AND WILL INCLUDE THIS MENTION IN THE FORECAST. TUESDAY NIGHT AND BEYOND...UPPER LOW PRESSURE WILL MEANDER OVER EASTERN IOWA BEFORE LIFTING INTO THE WESTERN GREAT LAKES ON THURSDAY INTO THURSDAY NIGHT. THE THREAT FOR LIGHT PRECIPITATION WILL CONTINUE THROUGH THURSDAY WITH A LIMITED CHANCE FOR RAIN OR SNOW OVER NORTHERN NEBRASKA DURING THE OVERNIGHT AND EARLY MORNING HOURS. WILL KEEP POPS SLIGHT AS MOISTURE WILL BE FAIRLY LIMITED AS WE HEAD INTO THE MIDDLE AND END OF THE WEEK. TEMPERATURES WILL SLOWLY MODERATE INTO THE 50S FOR WEDNESDAY AND THURSDAY...APPROACHING THE LOWER 60S FOR FRIDAY AND SATURDAY AS THE UPPER LEVEL LOW IS ABSORBED BY THE NRN STREAM AND LIFTED INTO EASTERN CANADA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 127 PM CDT SAT APR 26 2014 A SURFACE LOW OVER NORTHEAST COLORADO WILL SLOWLY MOVE EASTWARD THROUGH SUNDAY AFTERNOON. AS THIS OCCURS...BREEZY SOUTHEAST TO EASTERLY WINDS WILL OCCUR FOR MUCH OF THE NIGHT HOURS FOR PORTIONS OF CENTRAL INTO NORTH CENTRAL NEBRASKA. TO THE WEST...LIGHTER WINDS WILL BE OBSERVED IN THE REGION OF THE LOW...AND UP THROUGH THE PANHANDLE. WINDS WILL INCREASE IN THE WESTERN AREAS SUNDAY AFTERNOON AS THE LOW DRIFTS EAST. THERE WILL BE CHANCES FOR THUNDERSTORMS LATER THIS EVENING AND OVERNIGHT...MAINLY ACROSS THE PANHANDLE AND NORTH CENTRAL NEBRASKA. && .FIRE WEATHER... ISSUED AT 358 PM CDT SAT APR 26 2014 FIRE WEATHER CONCERNS WILL REMAIN HIGH THIS EVENING AS THE WARM FRONT LIFTS NORTH TO KEEP DRY AND BREEZY CONDITIONS ACROSS FIRE ZONE 210. CONDITIONS WILL IMPROVE AROUND MID EVENING AS TEMPERATURES FALL AND HUMIDITY STARTS TO RECOVER. TEMPERATURES WILL BE ON THE DOWNSLIDE FOR THE NEXT WEEK AS A LARGE STORM SYSTEM SITS OVER THE REGION. MUCH OF THE WEEK WILL SEE HIGHS IN THE 40S AND 50S...WITH PERIODIC CHANCES FOR RAIN...AND EVEN A CHANCE FOR SNOW IN SOME AREAS. HOWEVER...THIS SYSTEM WILL ALSO BRING AN EXTENDED PERIOD OF STRONG WINDS. IT LOOKS LIKELY FOR STRONG WINDS OF 30 TO 40 MPH TO BE POSSIBLE ALMOST DAILY IN PARTS OF THE AREA THROUGH THURSDAY. && .LBF WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 10 PM CDT THIS EVENING FOR NEZ210. && $$ SYNOPSIS...BROOKS SHORT TERM...BROOKS LONG TERM...CLB AVIATION...BROOKS FIRE WEATHER...BROOKS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
323 PM CDT SAT APR 26 2014 .SHORT TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 322 PM CDT SAT APR 26 2014 STORM SYSTEM IS DEEPENING AND BEGINNING TO AFFECT THE PLAINS. SUBJECTIVE 12Z UPPER AIR ANALYSIS INDICATES DEEPENING 500MB TROUGH IN THE WESTERN US...WITH 500MB HEIGHT FALLS UP TO 170M CENTERED IN THE CA/NV/AZ BORDER REGION...AND WITH SOUTHWESTERLY UPPER-LEVEL FLOW ACROSS THE CENTRAL US. 300MB JET UP TO 130KT WAS STILL ON THE WEST SIDE OF THE TROUGH...WITH 105-115KT AROUND THE BASE AND TOWARD THE EAST OF THE TROUGH AXIS. 850MB MOISTURE AT 12Z WAS FOCUSED IN TWO SEPARATE AREAS...ONE RIGHT ALONG THE GULF COAST...AND FROM WEST TX THROUGH OK INTO SOUTHWEST MO...WITH 850MB WINDS UP TO AROUND 50KT TRANSPORTING MOISTURE NORTHWARD INTO THE CENTRAL PLAINS. WEAK 850MB FRONT WAS NOTED FROM LOW IN NORTHERN WY/SOUTHERN MT THROUGH NEB INTO NORTHERN MO. 700-500MB DELTA-T OF 20-24C WAS NOTED ACROSS THE PLAINS...WITH THE HIGHEST VALUES ALONG THE HIGH PLAINS TOWARD OK/WEST TX. SURFACE LOW AT 19Z WAS CENTERED IN NORTHEAST CO...WITH WIND SHIFT WARM FRONT EXTENDING ACROSS NEB NEAR THE PLATTE RIVER TOWARD WEST CENTRAL TO SOUTHEAST IA...AND WITH MOISTURE GRADIENT NEAR THE KS/NE BORDER AS UPPER 50S DEWPOINTS HAD ADVANCED INTO NORTHEAST TO CENTRAL KS. MAIN FORECAST CONCERN IS VERY CONDITIONAL CONVECTIVE POTENTIAL THIS EVENING...CONVECTION ON CWA MARGINS TONIGHT...AND MORE WIDESPREAD CONVECTIVE POTENTIAL TOMORROW. RAP CONTINUES TO MIX OUT PROFILE DEEPLY BY 23-00Z AND DEVELOP VERY HIGH-BASED CONVECTION...WHILE HRRR HAS TRENDED FROM PRODUCING A CELL OR TWO THIS EVENING TO NEARLY DRY...AND 12Z 4KM WRF KEPT THE AREA MAINLY DRY THROUGH TONIGHT. MODELS THAT DO PRODUCE SOME CONVECTION LATER TONIGHT ARE DOING SO JUST IN OUR NORTHEASTERNMOST CWA. HAVE KEPT A VERY LOW-CONFIDENCE SMALL AREA OF POPS ADVANCING FROM SOUTHEAST NEB TO NEAR THE I-80 CORRIDOR IN THE EARLY EVENING...THEN SLIGHT CHANCES IN THE NORTHERN CWA THE REST OF THE EVENING BEFORE FOCUSING ON THE NORTHEASTERNMOST FRINGE FOR TONIGHT. AS UPPER LOW EJECTS ACROSS THE ROCKIES TOWARD KS/NEB ON SUNDAY...WITH INCREASING MOISTURE TRANSPORT INTO THE CENTRAL PLAINS...SHOULD SEE CONVECTION DEVELOP BY MIDDAY IN EASTERN NEB...SPREADING INTO WESTERN IA QUICKLY. WITH ABUNDANT SHEAR ACROSS THE AREA...POTENTIAL FOR SEVERE WEATHER DOES EXIST FOR ANY CONVECTION AS IT GETS GOING ACROSS THE AREA FROM MIDDAY THROUGH THE AFTERNOON. ALSO...AM THINKING THAT THERE WILL BE ENOUGH OF A BREAK IN CONVECTION TONIGHT THROUGH MUCH OF THE MORNING THAT AIRMASS WILL HAVE TIME TO SUFFICIENTLY DESTABILIZE AT LEAST IN THE SOUTHERN HALF OF THE CWA IF NOT ACROSS THE ENTIRE CWA. WITH SUCH STRONG UPPER- LEVEL SUPPORT THOUGH...CONVECTION WILL BE QUITE WIDESPREAD...AND THUS CONVECTIVE MODE/THREATS WILL BE MESSY AND COMPLICATED. WITH VERY STRONG DEEP-LAYER SHEAR...ROTATING LARGE HAIL WILL BE A THREAT...AS WELL AS POTENTIAL FOR DAMAGING WIND GUSTS. ENOUGH 0-1KM SHEAR EXISTS FOR A TORNADO THREAT FOR STORMS IF THEY CAN STAND ALONE...THOUGH WORTH NOTING THAT HODOGRAPHS ARE MORE STRAIGHT THAN CURVED IN MOST MODEL SOLUTIONS. STORMS WILL MOVE FAIRLY RAPIDLY TOWARD THE NORTH-NORTHEAST...AND AS THE SURFACE LOW PUSHES EASTWARD...SHOULD EXIT THE CWA THROUGH THE LATE AFTERNOON TO EARLY EVENING HOURS...LEAVING CWA IN DRY SLOT FOR THE REST OF THE NIGHT AND THROUGH MUCH OF MONDAY. ONCE UPPER LOW ADVANCES INTO NEB...IT IS PROGGED TO STALL THROUGH MONDAY...THEN FILL AND DRIFT EASTWARD INTO IOWA ON TUESDAY. PRECIPITATION WILL RETURN TO THE CWA IN THE WRAPAROUND AREA BEGINNING LATE MONDAY...EXPANDING ACROSS THE CWA THROUGH MONDAY NIGHT AND TUESDAY...WITH AT LEAST OCCASIONAL LIGHT PRECIPITATION CONTINUING THROUGH THURSDAY AS CWA REMAINS IN COOL CYCLONIC FLOW BEHIND THE UPPER LOW. REMOVED THUNDER MENTION FROM ANY PRECIPITATION FROM MONDAY EVENING ONWARD...AS AIRMASS REALLY STABILIZES ON THE COLD SIDE OF THE LOW. TEMPERATURES WILL BE MUCH COOLER BEHIND THE LOW...WITH TEMPERATURES ON MONDAY DOWN INTO THE 50S AND LIKELY STRUGGLING TO EVEN REACH 50 ON TUESDAY. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 322 PM CDT SAT APR 26 2014 GENERALLY COOLER AND UNSETTLED WEATHER PATTERN WILL CONTINUE THROUGH NEXT WEEKEND. HAVE KEPT SPECIFIC POP MENTIONS OUT OF MOST PERIODS FOR NOW...BUT THINK THERE IS A DECENT CHANCE TO GET AT LEAST LIGHT PRECIPITATION IN AT LEAST SOME PART OF THE CWA ON SOME PERIOD. FOR NOW...HAVE INCREASED CLOUDS A BIT. ALSO KEPT TEMPERATURES ON THE COOL SIDE...WITH TEMPERATURES CONTINUING IN THE 50S THROUGH THURSDAY BEFORE POSSIBLY REBOUNDING INTO THE 60S IN AT LEAST PART OF THE AREA BY FRIDAY OR SATURDAY. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1221 PM CDT SAT APR 26 2014 WILL LEAVE KOMA/KLNK TAF SITES DRY THROUGH THE PERIOD. ANY TSRA DEVELOPMENT THIS AFTN/EVNG WOULD BE TO ISOLATED TO INCLUDE AND AFTER THIS TIME THE ACTIVITY WILL LIKELY BE NORTH OF THE TAF SITES. THERE IS AN INCREASE THREAT OF SHRA/TSRA SUN MORNING AT THESE TAF SITES BUT TIMING AND COVERAGE CONCERNS PRECLUDE ANY MENTION AT THIS TIME. FOR KOFK WE WILL INCLUDE SOME SHOWERS SUN MORNING. OTHERWISE WE WILL SEEM MVFR CIGS MOVE INTO ALL TAFS AFTER 06Z TONIGHT AND MAY LOWER TO IFR AT KOFK BY SUN MORNING. WE WILL ALSO LIKELY SEE SOME MVFR VISBY AS WELL WITH INCREASING MOISTURE. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MAYES LONG TERM...MAYES AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1225 PM CDT SAT APR 26 2014 .UPDATE... ISSUED AT 1102 AM CDT SAT APR 26 2014 THE 12Z UPPER AIR ANALYSIS AND MODELS DID LITTLE IN PROVIDING A DECISIVE ANSWER AS TO THE THREAT OF SURFACED-BASED CONVECTIVE INITIATION LATER THIS AFTERNOON. THE UPPER AIR ANALYSIS INDICATED A WELL DEFINED EML EXTNG ACROSS THE PLAINS FROM THE DAKOTAS TO TX WITH 700 TO 500 MB DELTA-T VALUES >20 C WITH KOMA/KTOP ON THE ERN EDGE OF THIS CAPPING INVERSION AT 12Z. AT 500 MB THE MAIN STORM SYSTEM WAS STILL IN SRN NV/CA ASSOCIATED WITH A 170 M HEIGHT FALL AT LAS VEGAS. DOWNSTREAM HEIGHT FALLS WERE NOTED ACROSS THE HIGH PLAINS FROM KRAP TO KDDC TO KAMA OF 10 TO 30 M. THE LOW-LEVEL MOISTURE PROFILE AT 850 MB WAS STILL RATHER NARROW BUT DID SHOW AN AXIS OF >+10 C FROM WRN OK INTO SW TX. MODELS ARE INSISTENT THAT A STRONG AIRMASS ADJUSTMENT WILL TAKE PLACE TODAY WITH THIS SRN PLAINS MOISTURE MOVING INTO SE NEB BY LATE THIS AFTERNOON. ALTHOUGH THIS MAY BE OVERDONE TO SOME DEGREE...COMPARISON OF THE 15Z OBS TO 3 HOUR FORECAST FROM THE NAM INDICATES GOOD AGREEMENT. AS STRONG MIXING CONTINUES THROUGH THE AFTERNOON WE EXPECT TO SEE A BIT MORE OF A GAP IN THE FORECAST AND OBSERVED...BUT NEVERTHELESS LOWER TO MID 50S SHOULD MAKE IT INTO NE KS/SE NEB BY LATE AFTERNOON. GIVEN THE SEASONABLY STEEP MID TROPOSHERIC LAPSE RATES THIS WILL CREATE MLCAPE OF 1500-2000 J/KG BY 00Z. MODELS...ESPECIALLY THE GFS...ADVERTISE THE 10-20 M HEIGHT FALLS OVER-SPREADING ERN NEB THIS AFTERNOON. THIS...ALONG WITH THE CWA RESIDING IN THE LEFT EXIT REGION OF THE 65 KT H3 JET SAMPLED BY THE 12Z UPPER AIR ANALYSIS OVER WRN NEB/CO WILL AT LEAST CREATE A LARGE-SCALE ENVIRONMENT ISN`T OVERALY DETRIMENTAL TO CONVECTION INITIATION. POINT FORECAST SOUNDINGS FROM THE NAM CONT TO INSIST THAT THE EML WILL HOLD AND NO SURFACE-BASED CONVECTION WILL OCCUR. GIVEN THE MARGINAL MOISTURE AND LACK OF LARGE-SCALE ASCENT THIS ISN`T OUT OF THE QUESTION. SOME OF THE HIGH-RES MODELS /I.E. HRRR- RAP/ AS WELL AS THE OPERATIONAL GFS INDICATE THAT CI WILL OCCUR. THE POINT FORECAST SOUNDINGS FROM THE RAP APPEAR TO OVER MIX THE BOUNDARY LAYER LEADING TO A REDUCTION IN THE CAP THOUGH. HAVING SAID ALL THIS WE WILL MAINTAIN SOME SCHC FOR SOME STORMS THIS EVENING IN THE SOUTH...OTHERWISE IT STILL APPEARS THAT THE LOW- LEVEL JET WILL INCREASE ACTIVITY IN THE NORTH LATE THIS EVENING. IF STORMS DO DEVELOP 23-01Z IN THE SW ALL MODES OF SEVERE WEATHER STILL APPEAR POSSIBLE OTHERWISE THE STORMS IN THE NORTH SHOULD HAVE A MARGINAL HAIL THREAT. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 334 AM CDT SAT APR 26 2014 POTENTIAL FOR SEVERE THUNDERSTORMS THROUGH SUNDAY NIGHT REMAINS THE PRIMARY FORECAST CHALLENGE. SEVERAL BOUTS OF SEVERE STORMS ARE POSSIBLE TODAY AND SUNDAY IN PARTS OF EASTERN NEBRASKA AND SOUTHWEST IOWA...BUT THERE IS STILL WIDE VARIATION IN POSSIBLE SCENARIOS IN TIMING/LOCATION OF HIGHEST PROBABILITIES. UPPER TROUGH MOVING THROUGH CENTRAL CALIFORNIA THIS MORNING WILL MOVE THROUGH THE ROCKIES LATER TONIGHT AND EMERGE IN THE HIGH PLAINS SUNDAY AS A CLOSED LOW...WITH SURFACE LOW POSITION SETTING UP IN NORTHEAST QUADRANT OF UPPER LOW. NAM AND GFS ARE A COUPLE HUNDRED MILES APART IN SURFACE LOW POSITION AT 18Z SUNDAY...WITH ECMWF MORE IN LINE WITH NAM. HAVE FOLLOWED ECMWF MORE CLOSELY THAN OTHER MODELS IN THIS REGARD. SURFACE DEW POINTS ARE EXPECTED TO INCREASE INTO THE 50S LATER TODAY AS PRESSURES FALL IN THE HIGH PLAINS UNDER INCREASING DIFFLUENT FLOW ALOFT AHEAD OF UPPER WAVE. 50S DEW POINTS WERE SHOWING UP IN THE TEXAS PANHANDLE THIS MORNING...IN LINE WITH 6-HOUR FORECASTS OF 00Z MODELS...AND WILL ADVECT THROUGH KANSAS INTO SOUTHEAST NEBRASKA THIS AFTERNOON. MEANWHILE SURFACE TEMPERATURES WILL CLIMB INTO THE LOWER 80S...YIELDING SURFACE-BASED CAPE VALUES CLOSE TO 1200 J/KG BY 00Z IN SOUTHEAST NEBRASKA. HOWEVER FORECAST SOUNDINGS AND EXTRAPOLATION OF WARM MID LEVEL AIR CURRENTLY IN WEST TEXAS AND NEW MEXICO SUGGEST CAPPING WILL BE STRONG THROUGH THE AFTERNOON ACROSS ALL OF OUR AREA. WHILE SOME MODEL SOLUTIONS POP A FEW SHOWERS/STORMS BY LATE AFTERNOON...FEEL CAPPING WILL HOLD UNTIL LATER IN THE EVENING WHEN LOW LEVEL JET KICKS IN. BROAD AREA OF MOST-UNSTABLE CAPE NEAR 2000 J/KG AS PER ECMWF WILL ADVECT NORTH FROM CENTRAL KANSAS INTO EASTERN NEBRASKA BY 06Z. BULK SHEAR CLOSE TO 40KT WILL ALSO DEVELOP AS STRONGER FLOW AND COOLER TEMPERATURES AT MID LEVELS SPREAD INTO THE PLAINS. EXPECT CONVECTIVE INITIATION TO OCCUR IN SOUTH CENTRAL NEBRASKA DURING THE EVENING AND SPREAD/DEVELOP EAST/NORTHEAST INTO OUR AREA BY LATE EVENING. IF STORMS DO FIRE HERE...SURFACE WARM FRONT WILL COME INTO PLAY...ENHANCING LOW LEVEL SHEAR/HELICITY FOR AN ENHANCED RISK OF POTENTIAL TORNADIC STORMS...GENERALLY IN AREAS FROM ALBION TO COLUMBUS TO LINCOLN AND SOUTHWEST. A SECOND AREA OF INITIATION AROUND OR AFTER MIDNIGHT APPEARS LIKELY ON NOSE OF LOW LEVEL JET RIDING UP AND OVER SURFACE FRONT...FOCUSING ON AREAS FROM NORTHEAST NEBRASKA INTO WEST CENTRAL IOWA. THESE STORMS WILL BE ELEVATED WITH CAPE NEAR 1500 J/KG AND SHEAR OF 40KT TO WORK WITH...THUS LARGE HAIL WILL BE POSSIBLE. BY SUNDAY MORNING...A MID LEVEL WAVE ROTATING NORTHEAST AROUND UPPER LOW SPARKING CONVECTION IN KANSAS OVERNIGHT WILL SWING INTO EASTERN NEBRASKA. EXPECT MORE STORMS TO INVADE SOUTHEAST NEBRASKA EARLY IN THE DAY AND SPREAD NORTH THROUGH THE MORNING. INSTABILITY SHOULD BE WANING DURING THE MORNING...BUT SHEAR INCREASING. SO DESPITE A NORMAL LULL IN POTENTIAL SEVERE DURING THE MORNING HOURS...COMBINATION OF SHEAR/INSTABILITY WILL STILL SUPPORT AT LEAST SEVERE HAIL POTENTIAL IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. BY EARLY SUNDAY AFTERNOON...SURFACE DRYLINE IS FORECAST TO BE APPROACHING OUR SOUTHWEST CWA AND ROTATING EAST/NORTHEAST TOWARD THE MISSOURI RIVER BY LATE IN THE AFTERNOON OR EARLY EVENING. MORNING CONVECTION WILL PLAY A ROLE IN RECOVERY OF ATMOSPHERE AHEAD OF THE DRYLINE...WITH ECMWF SHOWING MOST-UNSTABLE CAPES DROPPING TO BELOW 1000 J/KG. BUT BULK SHEAR VALUES WILL STILL BE HIGH...AND ENHANCED LOW LEVEL SHEAR NEAR WARM FRONT/DRYLINE TRIPLE POINT LOOKS TO SET UP NEAR OR NORTH OF THE OMAHA METRO AREA BY 00Z. SO EXPECT EITHER A STRENGTHENING OF ONGOING CONVECTION OR NEW CONVECTION SUNDAY AFTERNOON IN AN ARC FROM NORTHEAST NEBRASKA INTO EAST CENTRAL NEBRASKA AND SOUTHWEST IOWA...WITH WIND/HAIL PRIMARY SEVERE POTENTIAL...AND A TORNADO POSSIBILITY NEAR WARM FRONT/DRYLINE INTERSECTION NEAR/NORTH OF OMAHA AND SOUTHEAST THROUGH SOUTHWEST IOWA. THIS CONVECTION IS EXPECTED TO ROTATE NORTHEAST SUNDAY EVENING AND SHOULD BE OUT OF OUR AREA SHORTLY AFTER MIDNIGHT. MEANWHILE UPPER LOW WILL BE DRIFTING EAST SUNDAY NIGHT INTO MONDAY...BUT SHOULD REMAIN WEST OF THE CWA. ECMWF KEEPS MOST OF OUR CWA DRY MONDAY...BUT COLD POOL ALOFT WILL ENHANCE LAPSE RATES...SO WILL LIKELY SEE SCATTERED SHOWERS/STORMS POPPING MONDAY AFTERNOON. SEVERE THREAT THEN SHOULD BE MINIMAL. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 334 AM CDT SAT APR 26 2014 SPEED OF UPPER LOW DRIFTING THROUGH THE PLAINS WILL BE THE PRIMARY CHALLENGE FOR NEXT WEEK...AND WILL BRING COOLER TEMPERATURES AND OFF- AND-ON SHOWER CHANCES AT LEAST THROUGH THURSDAY. TUESDAY APPEARS TO BE THE MOST LIKELY TIME OF WIDESPREAD SHOWERS AS UPPER LOW MOVES INTO IOWA/MISSOURI AND SIGNIFICANT WAVE ROTATES AROUND THE LOW. OTHERWISE WILL HAVE AT LEAST SMALL POPS EACH DAY/NIGHT THROUGH THURSDAY. HIGH TEMPERATURES THROUGH THE WEEK WILL AVERAGE IN THE 50S WITH A LITTLE WARMER WEATHER RETURNING FRIDAY AS UPPER LOW EXITS EAST. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1221 PM CDT SAT APR 26 2014 WILL LEAVE KOMA/KLNK TAF SITES DRY THROUGH THE PERIOD. ANY TSRA DEVELOPMENT THIS AFTN/EVNG WOULD BE TO ISOLATED TO INCLUDE AND AFTER THIS TIME THE ACTIVITY WILL LIKELY BE NORTH OF THE TAF SITES. THERE IS AN INCREASE THREAT OF SHRA/TSRA SUN MORNING AT THESE TAF SITES BY TIMING AND COVERAGE CONCERNS PRECLUDE ANY MENTION AT THIS TIME. FOR KOFK WE WILL INCLUDE SOME SHOWERS SUN MORNING. OTHERWISE WE WILL SEEM MVFR CIGS MOVE INTO ALL TAFS AFTER 06Z TONIGHT AND MAY LOWER TO IFR AT KOFK BY SUN MORNING. WE WILL ALSO LIKELY SEE SOME MVFR VISBY AS WELL WITH INCREASING MOISTURE. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ UPDATE...BOUSTEAD SHORT TERM...DERGAN LONG TERM...DERGAN AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1125 AM CDT SAT APR 26 2014 .UPDATE... ISSUED AT 1102 AM CDT SAT APR 26 2014 THE 12Z UPPER AIR ANALYSIS AND MODELS DID LITTLE IN PROVIDING A DECISIVE ANSWER AS TO THE THREAT OF SURFACED-BASED CONVECTIVE INITIATION LATER THIS AFTERNOON. THE UPPER AIR ANALYSIS INDICATED A WELL DEFINED EML EXTNG ACROSS THE PLAINS FROM THE DAKOTAS TO TX WITH 700 TO 500 MB DELTA-T VALUES >20 C WITH KOMA/KTOP ON THE ERN EDGE OF THIS CAPPING INVERSION AT 12Z. AT 500 MB THE MAIN STORM SYSTEM WAS STILL IN SRN NV/CA ASSOCIATED WITH A 170 M HEIGHT FALL AT LAS VEGAS. DOWNSTREAM HEIGHT FALLS WERE NOTED ACROSS THE HIGH PLAINS FROM KRAP TO KDDC TO KAMA OF 10 TO 30 M. THE LOW-LEVEL MOISTURE PROFILE AT 850 MB WAS STILL RATHER NARROW BUT DID SHOW AN AXIS OF >+10 C FROM WRN OK INTO SW TX. MODELS ARE INSISTENT THAT A STRONG AIRMASS ADJUSTMENT WILL TAKE PLACE TODAY WITH THIS SRN PLAINS MOISTURE MOVING INTO SE NEB BY LATE THIS AFTERNOON. ALTHOUGH THIS MAY BE OVERDONE TO SOME DEGREE...COMPARISON OF THE 15Z OBS TO 3 HOUR FORECAST FROM THE NAM INDICATES GOOD AGREEMENT. AS STRONG MIXING CONTINUES THROUGH THE AFTERNOON WE EXPECT TO SEE A BIT MORE OF A GAP IN THE FORECAST AND OBSERVED...BUT NEVERTHELESS LOWER TO MID 50S SHOULD MAKE IT INTO NE KS/SE NEB BY LATE AFTERNOON. GIVEN THE SEASONABLY STEEP MID TROPOSHERIC LAPSE RATES THIS WILL CREATE MLCAPE OF 1500-2000 J/KG BY 00Z. MODELS...ESPECIALLY THE GFS...ADVERTISE THE 10-20 M HEIGHT FALLS OVER-SPREADING ERN NEB THIS AFTERNOON. THIS...ALONG WITH THE CWA RESIDING IN THE LEFT EXIT REGION OF THE 65 KT H3 JET SAMPLED BY THE 12Z UPPER AIR ANALYSIS OVER WRN NEB/CO WILL AT LEAST CREATE A LARGE-SCALE ENVIRONMENT ISN`T OVERALY DETRIMENTAL TO CONVECTION INITIATION. POINT FORECAST SOUNDINGS FROM THE NAM CONT TO INSIST THAT THE EML WILL HOLD AND NO SURFACE-BASED CONVECTION WILL OCCUR. GIVEN THE MARGINAL MOISTURE AND LACK OF LARGE-SCALE ASCENT THIS ISN`T OUT OF THE QUESTION. SOME OF THE HIGH-RES MODELS /I.E. HRRR- RAP/ AS WELL AS THE OPERATIONAL GFS INDICATE THAT CI WILL OCCUR. THE POINT FORECAST SOUNDINGS FROM THE RAP APPEAR TO OVER MIX THE BOUNDARY LAYER LEADING TO A REDUCTION IN THE CAP THOUGH. HAVING SAID ALL THIS WE WILL MAINTAIN SOME SCHC FOR SOME STORMS THIS EVENING IN THE SOUTH...OTHERWISE IT STILL APPEARS THAT THE LOW- LEVEL JET WILL INCREASE ACTIVITY IN THE NORTH LATE THIS EVENING. IF STORMS DO DEVELOP 23-01Z IN THE SW ALL MODES OF SEVERE WEATHER STILL APPEAR POSSIBLE OTHERWISE THE STORMS IN THE NORTH SHOULD HAVE A MARGINAL HAIL THREAT. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 334 AM CDT SAT APR 26 2014 POTENTIAL FOR SEVERE THUNDERSTORMS THROUGH SUNDAY NIGHT REMAINS THE PRIMARY FORECAST CHALLENGE. SEVERAL BOUTS OF SEVERE STORMS ARE POSSIBLE TODAY AND SUNDAY IN PARTS OF EASTERN NEBRASKA AND SOUTHWEST IOWA...BUT THERE IS STILL WIDE VARIATION IN POSSIBLE SCENARIOS IN TIMING/LOCATION OF HIGHEST PROBABILITIES. UPPER TROUGH MOVING THROUGH CENTRAL CALIFORNIA THIS MORNING WILL MOVE THROUGH THE ROCKIES LATER TONIGHT AND EMERGE IN THE HIGH PLAINS SUNDAY AS A CLOSED LOW...WITH SURFACE LOW POSITION SETTING UP IN NORTHEAST QUADRANT OF UPPER LOW. NAM AND GFS ARE A COUPLE HUNDRED MILES APART IN SURFACE LOW POSITION AT 18Z SUNDAY...WITH ECMWF MORE IN LINE WITH NAM. HAVE FOLLOWED ECMWF MORE CLOSELY THAN OTHER MODELS IN THIS REGARD. SURFACE DEW POINTS ARE EXPECTED TO INCREASE INTO THE 50S LATER TODAY AS PRESSURES FALL IN THE HIGH PLAINS UNDER INCREASING DIFFLUENT FLOW ALOFT AHEAD OF UPPER WAVE. 50S DEW POINTS WERE SHOWING UP IN THE TEXAS PANHANDLE THIS MORNING...IN LINE WITH 6-HOUR FORECASTS OF 00Z MODELS...AND WILL ADVECT THROUGH KANSAS INTO SOUTHEAST NEBRASKA THIS AFTERNOON. MEANWHILE SURFACE TEMPERATURES WILL CLIMB INTO THE LOWER 80S...YIELDING SURFACE-BASED CAPE VALUES CLOSE TO 1200 J/KG BY 00Z IN SOUTHEAST NEBRASKA. HOWEVER FORECAST SOUNDINGS AND EXTRAPOLATION OF WARM MID LEVEL AIR CURRENTLY IN WEST TEXAS AND NEW MEXICO SUGGEST CAPPING WILL BE STRONG THROUGH THE AFTERNOON ACROSS ALL OF OUR AREA. WHILE SOME MODEL SOLUTIONS POP A FEW SHOWERS/STORMS BY LATE AFTERNOON...FEEL CAPPING WILL HOLD UNTIL LATER IN THE EVENING WHEN LOW LEVEL JET KICKS IN. BROAD AREA OF MOST-UNSTABLE CAPE NEAR 2000 J/KG AS PER ECMWF WILL ADVECT NORTH FROM CENTRAL KANSAS INTO EASTERN NEBRASKA BY 06Z. BULK SHEAR CLOSE TO 40KT WILL ALSO DEVELOP AS STRONGER FLOW AND COOLER TEMPERATURES AT MID LEVELS SPREAD INTO THE PLAINS. EXPECT CONVECTIVE INITIATION TO OCCUR IN SOUTH CENTRAL NEBRASKA DURING THE EVENING AND SPREAD/DEVELOP EAST/NORTHEAST INTO OUR AREA BY LATE EVENING. IF STORMS DO FIRE HERE...SURFACE WARM FRONT WILL COME INTO PLAY...ENHANCING LOW LEVEL SHEAR/HELICITY FOR AN ENHANCED RISK OF POTENTIAL TORNADIC STORMS...GENERALLY IN AREAS FROM ALBION TO COLUMBUS TO LINCOLN AND SOUTHWEST. A SECOND AREA OF INITIATION AROUND OR AFTER MIDNIGHT APPEARS LIKELY ON NOSE OF LOW LEVEL JET RIDING UP AND OVER SURFACE FRONT...FOCUSING ON AREAS FROM NORTHEAST NEBRASKA INTO WEST CENTRAL IOWA. THESE STORMS WILL BE ELEVATED WITH CAPE NEAR 1500 J/KG AND SHEAR OF 40KT TO WORK WITH...THUS LARGE HAIL WILL BE POSSIBLE. BY SUNDAY MORNING...A MID LEVEL WAVE ROTATING NORTHEAST AROUND UPPER LOW SPARKING CONVECTION IN KANSAS OVERNIGHT WILL SWING INTO EASTERN NEBRASKA. EXPECT MORE STORMS TO INVADE SOUTHEAST NEBRASKA EARLY IN THE DAY AND SPREAD NORTH THROUGH THE MORNING. INSTABILITY SHOULD BE WANING DURING THE MORNING...BUT SHEAR INCREASING. SO DESPITE A NORMAL LULL IN POTENTIAL SEVERE DURING THE MORNING HOURS...COMBINATION OF SHEAR/INSTABILITY WILL STILL SUPPORT AT LEAST SEVERE HAIL POTENTIAL IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. BY EARLY SUNDAY AFTERNOON...SURFACE DRYLINE IS FORECAST TO BE APPROACHING OUR SOUTHWEST CWA AND ROTATING EAST/NORTHEAST TOWARD THE MISSOURI RIVER BY LATE IN THE AFTERNOON OR EARLY EVENING. MORNING CONVECTION WILL PLAY A ROLE IN RECOVERY OF ATMOSPHERE AHEAD OF THE DRYLINE...WITH ECMWF SHOWING MOST-UNSTABLE CAPES DROPPING TO BELOW 1000 J/KG. BUT BULK SHEAR VALUES WILL STILL BE HIGH...AND ENHANCED LOW LEVEL SHEAR NEAR WARM FRONT/DRYLINE TRIPLE POINT LOOKS TO SET UP NEAR OR NORTH OF THE OMAHA METRO AREA BY 00Z. SO EXPECT EITHER A STRENGTHENING OF ONGOING CONVECTION OR NEW CONVECTION SUNDAY AFTERNOON IN AN ARC FROM NORTHEAST NEBRASKA INTO EAST CENTRAL NEBRASKA AND SOUTHWEST IOWA...WITH WIND/HAIL PRIMARY SEVERE POTENTIAL...AND A TORNADO POSSIBILITY NEAR WARM FRONT/DRYLINE INTERSECTION NEAR/NORTH OF OMAHA AND SOUTHEAST THROUGH SOUTHWEST IOWA. THIS CONVECTION IS EXPECTED TO ROTATE NORTHEAST SUNDAY EVENING AND SHOULD BE OUT OF OUR AREA SHORTLY AFTER MIDNIGHT. MEANWHILE UPPER LOW WILL BE DRIFTING EAST SUNDAY NIGHT INTO MONDAY...BUT SHOULD REMAIN WEST OF THE CWA. ECMWF KEEPS MOST OF OUR CWA DRY MONDAY...BUT COLD POOL ALOFT WILL ENHANCE LAPSE RATES...SO WILL LIKELY SEE SCATTERED SHOWERS/STORMS POPPING MONDAY AFTERNOON. SEVERE THREAT THEN SHOULD BE MINIMAL. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 334 AM CDT SAT APR 26 2014 SPEED OF UPPER LOW DRIFTING THROUGH THE PLAINS WILL BE THE PRIMARY CHALLENGE FOR NEXT WEEK...AND WILL BRING COOLER TEMPERATURES AND OFF- AND-ON SHOWER CHANCES AT LEAST THROUGH THURSDAY. TUESDAY APPEARS TO BE THE MOST LIKELY TIME OF WIDESPREAD SHOWERS AS UPPER LOW MOVES INTO IOWA/MISSOURI AND SIGNIFICANT WAVE ROTATES AROUND THE LOW. OTHERWISE WILL HAVE AT LEAST SMALL POPS EACH DAY/NIGHT THROUGH THURSDAY. HIGH TEMPERATURES THROUGH THE WEEK WILL AVERAGE IN THE 50S WITH A LITTLE WARMER WEATHER RETURNING FRIDAY AS UPPER LOW EXITS EAST. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 608 AM CDT SAT APR 26 2014 VFR CONDITIONS ARE EXPECTED THROUGHOUT MUCH OF THE TAF CYCLE. THE EXCEPTION WILL BE IN ANY TSTMS THAT DEVELOP. HAVE CONTINUED PROB30 GROUPS FOR ALL 3 SITES FROM THIS EVENING AND INTO EARLY SUNDAY MORNING WHEN SCATTERED CONVECTION IS POSSIBLE. SOME SEVERE STORMS ARE POSSIBLE. GUSTY SOUTHEAST WINDS OF 15 TO 20KTS WITH GUSTS TO 30KTS ARE LIKELY LATER THIS MORNING AND AFTERNOON. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ UPDATE...BOUSTEAD SHORT TERM...DERGAN LONG TERM...DERGAN AVIATION...KERN
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1135 PM CDT FRI APR 25 2014 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 344 PM CDT FRI APR 25 2014 THE ONGOING DROUGHT WILL CONTINUE THE FOCUS FOR CRITICAL FIRE CONDITIONS SATURDAY AS WARM FRONT LIFTS NORTH AND EAST. DEEP MOISTURE WILL BE LACKING WHERE STORMS THAT DO FORM WILL CREATE A BETTER CHANCE FOR HIGH BASED THUNDERSTORMS AND A LIGHTNING DANGER FOR FIRE IGNITION. SEE FIRE WEATHER DISCUSSION BELOW FOR MORE DETAILS. FORECAST TONIGHT INTO SATURDAY TRENDED TOWARD THE HIRES ECMWF. THE MODELS ARE CREATING MORE OF A SPREAD AS THE UPPER FLOW PATTERN SLOWS. THE 250 MB JETSTREAM WILL CONTINUE TO CARVE OUT THE LONGWAVE TROUGH MOVING INLAND ACROSS THE WEST COAST THIS EVENING. THE MODELS MAY STILL BE TOO FAST MOVING THE SURFACE LOW PRESSURE SYSTEM OUT ON THE PLAINS SATURDAY EVENING. FOR THE LOCAL AREA TONIGHT QUIET WITH SOME HIGH CLOUDS WHILE TEMPERATURES DROP INTO THE 40S. SATURDAY THE SURFACE SYSTEM WILL ORGANIZE WITH THE DRYLINE EXTENDING SOUTH FROM NEAR IMPERIAL SOUTH ACROSS WESTERN KANSAS. A WARM FRONT WILL LIFT NORTH AND EAST WITH TEMPERATURES CLIMBING INTO THE MID 80S SOUTHWEST TO MID 70S NORTH CENTRAL. THE PREVAILING SOUTHWEST FLOW WILL DO LITTLE TO IMPROVE DEEP MOISTURE THROUGH 21Z WITH A NARROW OPPORTUNITY FOR STORM DEVELOPMENT UNTIL EVENING. ISOLATED THUNDERSTORMS THAT FORM SHOULD BE HIGH BASED WITH BETTER FOCUS TOWARD THE SOUTH CENTRAL BY EVENING AS LOW LEVEL JET STRENGTHENS TO INCREASE THE MOISTURE PROFILE FOR BETTER STORM POTENTIAL IN THE SATURDAY NIGHT PERIOD...WITH STORM MOTION TO FOCUS OVER THE NORTH CENTRAL WHERE A SLIGHT RISK FOR SEVERE STORMS CURRENTLY EXISTS. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 344 PM CDT FRI APR 25 2014 HIGHLIGHTS OF THE LONG TERM PORTION OF THE FORECAST BEGIN WITH SEVERE THUNDERSTORM CHANCES SATURDAY NIGHT AND SUNDAY...THEN TURN TO POTENTIAL FOR SNOW AND COLD AND WINDY CONDITIONS AS A LARGE STORM SYSTEM SLOWLY MAKES ITS WAY ACROSS THE CENTRAL PART OF THE COUNTRY. THE UPPER LEVEL TROUGH CURRENTLY OFF THE WEST COAST WILL MAKE ITS WAY ACROSS THE GREAT BASIN THROUGH THE DAY SATURDAY THEN WILL LIFT INTO THE CENTRAL PLAINS SATURDAY NIGHT AND SUNDAY. AS A SURFACE LOW DEVELOPS AHEAD OF THE UPPER LEVEL SYSTEM...THE WARM FRONT WILL LIFT NORTH ACROSS NEBRASKA SATURDAY EVENING AND BY 06Z SHOULD BE ROUGHLY FROM EXTREME NORTHEAST COLORADO INTO NORTHEAST NEBRASKA WITH THE SURFACE LOW SITUATED OVER THE SOUTHEAST NEBRASKA PANHANDLE. THE MODELS HAVE BEEN CONSISTENT WITH A DRYLINE EXTENDING SLIGHTLY EAST OF THE LOW TO NEAR HIGHWAY 83 BY KLBF AND THEN GOING SOUTH THROUGH WESTERN KANSAS. THIS IS A FAIRLY TIGHT DRYLINE WITH DEWPOINTS VARYING FROM THE LOW 20S TO THE MID 50S IN A SHORT AREA. THERE WILL BE A STRONG LOW LEVEL JET SATURDAY EVENING...HOWEVER SOUNDINGS ARE SHOWING AREAS IN THE WARM SECTOR STAYING CAPPED. THERE IS DECENT SHEAR...SO IF ENOUGH MOISTURE IS BROUGHT NORTH TO GET STORMS TO DEVELOP ALONG THE WARM FRONT THEY COULD BECOME ORGANIZED. SO THERE IS POTENTIAL FOR STORMS...YET HIGHER CHANCES WILL LIE INTO EASTERN NEBRASKA WHERE MORE MOISTURE WILL BE IN PLACE. WITH THE CAP IN PLACE AND LACK OF MOISTURE IN THE LOWER LEVELS...BETTER CHANCES MAY BE FOR ELEVATED CONVECTION SO THREATS FROM STORMS WOULD BE MAINLY LARGE HAIL AND STRONG WINDS. THAT BEING SAID...THE TRACK OF THE UPPER LEVEL SYSTEM WOULD SUGGEST MUCH OF NEBRASKA MAY GET DRY SLOTTED SATURDAY NIGHT INTO SUNDAY. THE TREND IN THE MOST RECENT MODEL RUNS HAS BEEN IN THIS DIRECTION SO PRECIPITATION CHANCES HAVE BEEN REDUCED ACCORDINGLY. BY SUNDAY MORNING AT 12Z...THE UPPER LOW IS CENTERED OVER EASTERN COLORADO AND BEYOND THAT POINT DIFFERENCES IN THE NORTH TO SOUTH ASPECT OF THE SYSTEM START TO DIVERGE. BY 28.00Z THE DIFFERENCE IN THE 500MB LOW RANGES FROM ROUGHLY OVER SHERIDAN AND CHERRY COUNTIES INTO SOUTH DAKOTA IN THE GFS TO THE WESTERN NEBRASKA SANDHILLS IN THE ECMWF AND GEM...TO THE COLBY/HILL CITY AREAS IN KANSAS IN THE NAM. THE DIFFERENCE IN THESE SOLUTIONS BRINGS A CONSIDERABLE LACK IN CONFIDENCE ON WHAT THE OUTCOME WILL BE FOR SENSIBLE WEATHER SUNDAY AND BEYOND. THIS FORECAST PACKAGE TRENDED BETWEEN THE MORE SOUTHERN SOLUTIONS WITH IT COMING FROM BLENDS OF THESE MODELS. WITH THE GFS NOT BEING CONSIDERED...DRY AIR DOES CONTINUE TO MOVE INTO THE REGION AS THE UPPER LOW MOVES ACROSS THE CENTRAL PLAINS. HOWEVER THE ECMWF/GEM RUNS WOULD KEEP A LOT OF THE AREA DRY ALL DAY WHILE PRECIPITATION WOULD BE EXPECTED OVER MUCH OF NORTHERN NEBRASKA. WHEREVER THE SURFACE LOW TRACKS...THERE WILL BE A TIGHT DRYLINE ORIENTED EAST OF THE LOW...THEN SOUTHWARD THROUGH EASTERN KANSAS. THE MODELS DO SHOW MOISTURE BING TRANSPORTED BACK INTO NORTH CENTRAL NEBRASKA AHEAD OF THE DRYLINE AND SOUNDINGS SHOW THE CAP ERODING BY MID AFTERNOON SO CONVECTION IS POSSIBLE. THE HIGHER CHANCES CURRENTLY ARE OVER NORTH CENTRAL NEBRASKA...AND WHILE THE DEEP LAYER BULK SHEAR ISN/T GREAT...THERE IS ABOUT 30KTS IN THESE AREAS SO WHILE WIDESPREAD SEVERE STORMS MAY NOT OCCUR...ITS NOT OUT OF THE QUESTION TO MAYBE GET A FEW STRONG TO SEVERE STORMS. ANOTHER CONCERN FOR SUNDAY IS IF THE NAM IS ON THE RIGHT TRACK...THERE COULD BE A VERY NARROW BAND OF WEAK CAPE THAT IS PULLED AROUND THE LOW LEVEL CIRCULATION. THIS WOULD BE CO-LOCATED WITH STEEP LOW LEVEL LAPSE RATES /AS COLD AIR WITH THE UPPER LEVEL LOW MOVES INTO THE AREA/...AS WELL AS A SURFACE INVERTED TROUGH FROM SOUTHWEST INTO NORTH CENTRAL NEBRASKA. IF THIS SITUATION WOULD PAN OUT...ANY CONVECTION ALONG THIS SURFACE BOUNDARY COULD HAVE THE POTENTIAL TO PRODUCE NON- SUPERCELL TORNADOS. SUNDAY NIGHT...COLD AIR WILL ADVECT INTO THE FORECAST AREA ON THE BACKSIDE OF THE SYSTEM. HOW COLD THE AIR WILL BE IS STILL IN QUESTION DEPENDENT ON THE TRACK OF THE UPPER LOW. THE ECMWF/GEM/NAM WOULD BRING ENOUGH COLD AIR INTO THE PANHANDLE AND WESTERN SANDHILLS TO SUGGEST PRECIPITATION WILL CHANGE OVER TO SNOW OVERNIGHT. AS THE NORTHERN SOLUTION HAS BEEN DISCOUNTED AT THIS TIME...DID INSERT A RAIN/SNOW MIX INTO THE FORECAST FOR SUNDAY NIGHT INTO MONDAY MORNING. AT THIS TIME AM NOT GOING TO INTRODUCE ANY AMOUNTS DUE TO HIGH UNCERTAINTY IN ACCUMULATION...BUT WOULD NOT BE SURPRISED TO SEE A FEW FLAKES AT LEAST. THAT BEING SAID...IF THE NAM WOULD BE ON THE RIGHT TRACK...THERE WOULD BE POTENTIAL FOR ACCUMULATING SNOW...ESPECIALLY FROM OGALLALA TO THEDFORD TO AINSWORTH AND AREAS TO THE WEST. MOVING THROUGH THE WEEK...A SHORT LIVED REX BLOCKING PATTERN SETS UP WITH AN UPPER HIGH OVER HUDSON BAY AND CENTRAL CANADA WITH THE WEEKEND SYSTEM STAYING CENTERED OVER THE CENTRAL PLAINS. THE UPPER LEVEL SYSTEM IS LIKELY TO SIT AND SPIN OVER THE REGION THROUGH MUCH OF THE NEXT WEEK. WHILE THIS IS ONGOING...TEMPERATURES WILL BE COOL /HIGHS IN THE 40S AND 50S...LOWS IN THE 30S./ WITH CHANCES FOR LIGHT PRECIPITATION DAILY. IT ALSO DOES LOOK COLD ENOUGH MONDAY AND TUESDAY NIGHTS FOR ANOTHER SHOT OF SNOW FOR PORTIONS OF THE AREA. AGAIN...CONFIDENCE ON ACCUMULATING SNOW IS LOW SO AT THIS TIME JUST HAVE A CHANCE FOR RAIN/SNOW IN THIS TIME PERIOD. THE MODELS ARE STARTING TO AT LEAST SLOWLY MOVE THE SYSTEM EAST BY THE END OF THE WORK WEEK. THIS WILL ALLOW A VERY GRADUAL WARM UP INTO NEXT WEEKEND WITH CHANCES FOR PRECIPITATION WANING. THE LAST CONCERN IS WINDS. AS THE SYSTEM MOVES ACROSS THE PLAINS...THERE WILL BE POTENTIAL FOR STRONG WINDS DAILY...SUNDAY NIGHT THROUGH THURSDAY. WITH THE SLOW MOVEMENT...AREAS ESPECIALLY WEST OF HIGHWAY 83 WILL BE ON THE BACK SIDE OF THE SYSTEM WHICH WILL LEAD TO A TIGHT PRESSURE GRADIENT...COLD AIR ADVECTION...SUBSIDENCE AT TIMES...AND WITH STRONG WINDS ALOFT...ANY MIXING COULD BRING VERY STRONG WINDS TO THE AREA. WILL NEED TO WATCH THE NEED FOR HEADLINES FOR WINDS THROUGH MUCH OF THE WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 1135 PM CDT FRI APR 25 2014 VFR IS EXPECTED ALL AREAS TONIGHT THROUGH 21Z SATURDAY. THEREAFTER...ISOLATED STRONG THUNDERSTORMS MAY DEVELOP...GENERALLY ALONG AND NORTH OF NEBRASKA HIGHWAY 2. STORM MOTION WILL BE NORTHEAST AT AROUND 25 MPH. STORM DEVELOPMENT IS EXPECTED TO BECOME SCATTERED ACROSS NORTHWEST NEB SATURDAY EVENING WHILE REMAINING ISOLATED ELSEWHERE. VFR CIGS PREVAIL THROUGH AT LEAST 03Z SATURDAY EVENING. THERE IS A CHANCE FOR MVFR CIGS IN THE NORTHEAST AS MOISTURE POOLS ALONG A STATIONARY FRONT. THIS WOULD BECOME MORE LIKELY FROM 06Z SATURDAY NIGHT ONWARD. && .FIRE WEATHER... ISSUED AT 1135 PM CDT FRI APR 25 2014 THE RAP AND NAM MODELS ARE GIVING A GOOD SIGNAL FOR RED FLAG CONDITIONS ACROSS THE FRENCHMAN BASIN SATURDAY. A SURGE OF DRY AIR WILL BE MOVING NORTH THRU KS DURING THE AFTN. A RED FLAG WARNING IS IN PLACE FOR FRENCHMAN BASIN. && .LBF WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 1 PM TO 10 PM CDT SATURDAY FOR NEZ210. && $$ SHORT TERM...KECK LONG TERM...BROOKS AVIATION...CDC FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS ELKO NV
1124 AM PDT SAT APR 26 2014 .SYNOPSIS...LINGERING SHOWERS WILL CONTINUE ACROSS EASTERN NEVADA TODAY BEHIND A STRONG LATE WINTER STORM. DRY WEATHER RETURNS BRIEFLY SATURDAY NIGHT...FOLLOWED BY MORE SNOW SHOWERS ACROSS NORTHERN NEVADA ON SUNDAY. DRIER AND WARMER WEATHER IS EXPECTED TO RETURN NEXT WEEK. && .UPDATE...LET WINTER WEATHER PRODUCTS EXPIRE AT 11 AM AS STORM SYSTEM EXITING THE AREA WITH ONLY ISOLATED TO SCATTERED SNOW SHOWERS OCCURRING AT THIS TIME ACROSS ERN NV WITH LITTLE OR NO ADDITIONAL ACCUMULATION EXPECTED. ALSO REDUCED SHOWER COVERAGE INTO THE ISOLATED TO SCATTERED CATEGORY. && .PREV DISCUSSION... /ISSUED AT 815 AM / SYNOPSIS...A STRONG LATE WINTER STORM WILL BRING WIDESPREAD RAIN AND SNOW TO NEVADA THROUGH SATURDAY MORNING. DRY WEATHER RETURNS BRIEFLY SATURDAY NIGHT...FOLLOWED BY MORE SNOW SHOWERS ACROSS NORTHERN NEVADA ON SUNDAY. DRIER AND WARMER WEATHER IS EXPECTED TO RETURN NEXT WEEK. SHORT TERM...TODAY THROUGH MONDAY. STRONG BUT PROGRESSIVE LATE WINTER/SPRING STORM SHAPING UP PRETTY MUCH AS PLANNED THIS MORNING. NAM/GFS/HRRR GUIDANCE IN EXCELLENT AGREEMENT THAT THE PEAK OF THIS WINTER WEATHER EVENT WILL OCCUR EARLY THIS MORNING, A FEW HOURS EITHER SIDE OF SUNRISE, ALONG A TONOPAH-EUREKA-NW WHITE PINE COUNTY-SE ELKO COUNTY LINE. HEAVY WET SNOW WILL FALL IN THIS CORRIDOR FOR SEVERAL HOURS FROM NOW THROUGH EARLY SATURDAY MORNING, WITH SEVERAL INCHES EXPECTED ESPECIALLY ON ELEVATED/VEGETATED SURFACES. IMPACTS WILL BE VERY ELEVATION DEPENDENT, TYPICAL OF LATE APRIL SNOWSTORMS, BUT PASSES AND SUMMITS ABOVE 5500 FEET WILL BE SLUSH/SNOW COVERED AND TREACHEROUS THIS MORNING. WILL ALLOW WINTER STORM WARNINGS TO CONTINUE AS PLANNED. A WILDCARD IN REGARD TO SNOWFALL AMOUNTS IS CONVECTION. LIGHTNING DETECTION AND IR SATELLITE CONTINUES TO INDICATE THUNDERSTORMS ROTATING NORTHWARD INTO WHITE PINE COUNTY. SNOWFALL RATES WILL BE ERRATIC AND BRIEFLY INTENSE IN THE WINTER STORM WARNING AREA THIS MORNING. SINCE THE SNOW IS OCCURRING ON A SATURDAY MORNING WITH NO SCHOOL AND LIMITED COMMUTING, IMPACTS WILL BE LIMITED, BUT NONETHELESS THESE INTENSE SNOWFALL RATES WILL LIKELY OVERCOME ANY WARM ROADWAYS AND MAKE TRAVEL DANGEROUS AT TIMES UNTIL THE MID-MORNING HOURS. REGARDING ELKO COUNTY...00Z NAM AND HRRR BOTH DEPICT A VERY TIGHT PRECIPITATION GRADIENT, WITH NW ELKO COUNTY GETTING LITTLE TO NO SNOW, AND HEAVY SNOW FALLING ON THE RUBY MOUNTAINS AND SE ELKO COUNTY. SNOWFALL FROM 00Z NAM SHOWS THIS TIGHT GRADIENT AND APPEARS VERY REASONABLE ON THE NW EDGE OF THE DEFORMATION BAND. EXPECTING ABOUT 1/2 INCH AT ELKO PROPER, 2-4 INCHES IN SPRING CREEK, AND NEAR 6 INCHES ADJACENT TO THE RUBY MOUNTAINS, SUCH AS JIGGS, LEE, AND LAMOILLE. WILL ALSO KEEP THE WINTER WEATHER ADVISORY GOING FOR ELEVATIONS ABOVE 5500 FEET FOR ELKO COUNTY THROUGH 11 AM. PRIMARY SURFACE LOW SW OF ELY EARLY THIS MORNING WILL RAPIDLY PULL EASTWARD THROUGH UTAH THIS MORNING, AND BE IN WYOMING BY MIDDAY. IN OTHER WORDS, SYSTEM IS QUITE PROGRESSIVE AND SNOW SHOWERS WILL TAPER OFF QUICKLY AFTER NOON. ALSO, IMPACTS TO ROADWAYS WILL END RAPIDLY AFTER 11 AM WITH THE LATE APRIL SUNSHINE, SO ALL WINTER HEADLINES WILL EXPIRE AT THAT TIME. NW FLOW AND COLD AIR ALOFT IS QUITE AGITATED THIS AFTERNOON, SO KEPT PLENTY OF SNOW/SNOW PELLET SHOWERS MENTIONED THIS AFTERNOON, BUT AMOUNTS WILL BE LIGHT. NW WINDS WILL BE STRONG AND GUSTY TODAY AS THE STORM SYSTEM DEPARTS. NW WINDS WILL AVERAGE 20-30 MPH WITH HIGHER GUSTS. BELIEVE WINDS WILL REMAIN BELOW ADVISORY CRITERIA, WITH THE EXCEPTION OF NW NYE COUNTY/TONOPAH. WIND GUSTS OF 50-55 MPH APPEAR LIKELY HERE TODAY, AND ISSUED A WIND ADVISORY FOR NW NYE COUNTY FROM 5 AM THROUGH 5 PM. A BRIEF BREAK OF DRY WEATHER TONIGHT, WITH LOWS NEAR FREEZING. SUNDAY...FINAL SHORTWAVE SKIRTS THROUGH NORTHERN NEVADA IN THE CHILLY NW FLOW. THIS SHOULD BE A PROLIFIC SNOW AND GRAUPEL SHOWER PRODUCER SUNDAY AFTERNOON MAINLY ACROSS ELKO COUNTY. INCREASED SHOWER COVERAGE IN THE GRIDS, BUT APPEARS TO BE A HIGH POP/LOW QPF SITUATION IN WHICH AMOUNTS WILL BE INSIGNIFICANT. STILL, VISIBILITY WILL BE SHARPLY REDUCED BY THESE PASSING CONVECTIVE SNOW SHOWERS. 00Z GFS DEPICTS LIFTED INDEX LESS THAN ZERO ACROSS ELKO COUNTY SUNDAY AFTERNOON, SO MENTIONED ISOLATED THUNDER AS WELL. SUNDAY WILL BE A DECIDEDLY UNPLEASANT "SPRING" DAY IN NEVADA WITH TEMPERATURES STUCK IN THE 40S MOST OF THE DAY, AND STRONG GUSTY WEST WINDS OF 20-30 MPH MAKING IT FEEL EVEN COLDER THAN THAT. SOME DECREASE IN CLOUDS SUNDAY NIGHT, ALLOWING FOR COLDER LOWS MONDAY MORNING IN THE MID TO UPPER 20S. MONDAY...DRY WEATHER RETURNS UNDER DRY NW FLOW. STILL QUITE CHILLY, WITH TEMPERATURES RUNNING ABOUT 10 DEGREES BELOW LATE APRIL NORMALS. TURNER LONG TERM...MONDAY NIGHT THROUGH FRIDAY. HIGH PRESSURE WILL BRING DRY CONDITIONS TO THE GREAT BASIN WITH A WARMING TREND. THERE IS GOOD MODEL AGREEMENT INDICATING THAT A PACIFIC RIDGE WILL STRONGLY AMPLIFY NEXT WEEK AND PROGRESS EAST AT AN EXTREMELY SLOW RATE. THE RIDGE AXIS WILL ONLY MOVE FROM OFF THE CALIFORNIA COAST MONDAY NIGHT TO REPOSITION THROUGH NEVADA FRIDAY...AS THE DE-AMPLIFICATION PROCESS BEGINS. LOW TEMPERATURES WILL GENERALLY FALL INTO THE 20S MONDAY NIGHT...AND THE 30S THEREAFTER. HIGH TEMPERATURES WILL GENERALLY BE IN THE 50S TUESDAY...RISE INTO THE 60S WEDNESDAY...THEN INTO THE 70S IN MANY PLACES THURSDAY AND FRIDAY. AVIATION...A MOISTURE-LADEN STORM SYSTEM WILL CONTINUE TO BRING WIDESPREAD RAIN AND SNOW SHOWERS THROUGH SATURDAY MORNING PRODUCING AREAS OF MVFR CONDITIONS. SHOWERS WILL TAPER OFF THIS EVENING AND THERE MAY BE A BRIEF BREAK AFTER THIS STORM EXITS. HOWEVER ANOTHER WAVE OF LOW PRESSURE WILL BRING MORE SHOWER ACTIVITY THROUGH SUNDAY MORNING. && .LKN WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR NORTHWESTERN NYE COUNTY. && $$ 91/99/92
AREA FORECAST DISCUSSION
NWS ELKO NV
815 AM PDT SAT APR 26 2014 .SYNOPSIS...A STRONG LATE WINTER STORM WILL BRING WIDESPREAD RAIN AND SNOW TO NEVADA THROUGH SATURDAY MORNING. DRY WEATHER RETURNS BRIEFLY SATURDAY NIGHT...FOLLOWED BY MORE SNOW SHOWERS ACROSS NORTHERN NEVADA ON SUNDAY. DRIER AND WARMER WEATHER IS EXPECTED TO RETURN NEXT WEEK. && .SHORT TERM...TODAY THROUGH MONDAY. STRONG BUT PROGRESSIVE LATE WINTER/SPRING STORM SHAPING UP PRETTY MUCH AS PLANNED THIS MORNING. NAM/GFS/HRRR GUIDANCE IN EXCELLENT AGREEMENT THAT THE PEAK OF THIS WINTER WEATHER EVENT WILL OCCUR EARLY THIS MORNING, A FEW HOURS EITHER SIDE OF SUNRISE, ALONG A TONOPAH-EUREKA-NW WHITE PINE COUNTY-SE ELKO COUNTY LINE. HEAVY WET SNOW WILL FALL IN THIS CORRIDOR FOR SEVERAL HOURS FROM NOW THROUGH EARLY SATURDAY MORNING, WITH SEVERAL INCHES EXPECTED ESPECIALLY ON ELEVATED/VEGETATED SURFACES. IMPACTS WILL BE VERY ELEVATION DEPENDENT, TYPICAL OF LATE APRIL SNOWSTORMS, BUT PASSES AND SUMMITS ABOVE 5500 FEET WILL BE SLUSH/SNOW COVERED AND TREACHEROUS THIS MORNING. WILL ALLOW WINTER STORM WARNINGS TO CONTINUE AS PLANNED. A WILDCARD IN REGARD TO SNOWFALL AMOUNTS IS CONVECTION. LIGHTNING DETECTION AND IR SATELLITE CONTINUES TO INDICATE THUNDERSTORMS ROTATING NORTHWARD INTO WHITE PINE COUNTY. SNOWFALL RATES WILL BE ERRATIC AND BRIEFLY INTENSE IN THE WINTER STORM WARNING AREA THIS MORNING. SINCE THE SNOW IS OCCURRING ON A SATURDAY MORNING WITH NO SCHOOL AND LIMITED COMMUTING, IMPACTS WILL BE LIMITED, BUT NONETHELESS THESE INTENSE SNOWFALL RATES WILL LIKELY OVERCOME ANY WARM ROADWAYS AND MAKE TRAVEL DANGEROUS AT TIMES UNTIL THE MID-MORNING HOURS. REGARDING ELKO COUNTY...00Z NAM AND HRRR BOTH DEPICT A VERY TIGHT PRECIPITATION GRADIENT, WITH NW ELKO COUNTY GETTING LITTLE TO NO SNOW, AND HEAVY SNOW FALLING ON THE RUBY MOUNTAINS AND SE ELKO COUNTY. SNOWFALL FROM 00Z NAM SHOWS THIS TIGHT GRADIENT AND APPEARS VERY REASONABLE ON THE NW EDGE OF THE DEFORMATION BAND. EXPECTING ABOUT 1/2 INCH AT ELKO PROPER, 2-4 INCHES IN SPRING CREEK, AND NEAR 6 INCHES ADJACENT TO THE RUBY MOUNTAINS, SUCH AS JIGGS, LEE, AND LAMOILLE. WILL ALSO KEEP THE WINTER WEATHER ADVISORY GOING FOR ELEVATIONS ABOVE 5500 FEET FOR ELKO COUNTY THROUGH 11 AM. PRIMARY SURFACE LOW SW OF ELY EARLY THIS MORNING WILL RAPIDLY PULL EASTWARD THROUGH UTAH THIS MORNING, AND BE IN WYOMING BY MIDDAY. IN OTHER WORDS, SYSTEM IS QUITE PROGRESSIVE AND SNOW SHOWERS WILL TAPER OFF QUICKLY AFTER NOON. ALSO, IMPACTS TO ROADWAYS WILL END RAPIDLY AFTER 11 AM WITH THE LATE APRIL SUNSHINE, SO ALL WINTER HEADLINES WILL EXPIRE AT THAT TIME. NW FLOW AND COLD AIR ALOFT IS QUITE AGITATED THIS AFTERNOON, SO KEPT PLENTY OF SNOW/SNOW PELLET SHOWERS MENTIONED THIS AFTERNOON, BUT AMOUNTS WILL BE LIGHT. NW WINDS WILL BE STRONG AND GUSTY TODAY AS THE STORM SYSTEM DEPARTS. NW WINDS WILL AVERAGE 20-30 MPH WITH HIGHER GUSTS. BELIEVE WINDS WILL REMAIN BELOW ADVISORY CRITERIA, WITH THE EXCEPTION OF NW NYE COUNTY/TONOPAH. WIND GUSTS OF 50-55 MPH APPEAR LIKELY HERE TODAY, AND ISSUED A WIND ADVISORY FOR NW NYE COUNTY FROM 5 AM THROUGH 5 PM. A BRIEF BREAK OF DRY WEATHER TONIGHT, WITH LOWS NEAR FREEZING. SUNDAY...FINAL SHORTWAVE SKIRTS THROUGH NORTHERN NEVADA IN THE CHILLY NW FLOW. THIS SHOULD BE A PROLIFIC SNOW AND GRAUPEL SHOWER PRODUCER SUNDAY AFTERNOON MAINLY ACROSS ELKO COUNTY. INCREASED SHOWER COVERAGE IN THE GRIDS, BUT APPEARS TO BE A HIGH POP/LOW QPF SITUATION IN WHICH AMOUNTS WILL BE INSIGNIFICANT. STILL, VISIBILITY WILL BE SHARPLY REDUCED BY THESE PASSING CONVECTIVE SNOW SHOWERS. 00Z GFS DEPICTS LIFTED INDEX LESS THAN ZERO ACROSS ELKO COUNTY SUNDAY AFTERNOON, SO MENTIONED ISOLATED THUNDER AS WELL. SUNDAY WILL BE A DECIDEDLY UNPLEASANT "SPRING" DAY IN NEVADA WITH TEMPERATURES STUCK IN THE 40S MOST OF THE DAY, AND STRONG GUSTY WEST WINDS OF 20-30 MPH MAKING IT FEEL EVEN COLDER THAN THAT. SOME DECREASE IN CLOUDS SUNDAY NIGHT, ALLOWING FOR COLDER LOWS MONDAY MORNING IN THE MID TO UPPER 20S. MONDAY...DRY WEATHER RETURNS UNDER DRY NW FLOW. STILL QUITE CHILLY, WITH TEMPERATURES RUNNING ABOUT 10 DEGREES BELOW LATE APRIL NORMALS. TURNER .LONG TERM...MONDAY NIGHT THROUGH FRIDAY. HIGH PRESSURE WILL BRING DRY CONDITIONS TO THE GREAT BASIN WITH A WARMING TREND. THERE IS GOOD MODEL AGREEMENT INDICATING THAT A PACIFIC RIDGE WILL STRONGLY AMPLIFY NEXT WEEK AND PROGRESS EAST AT AN EXTREMELY SLOW RATE. THE RIDGE AXIS WILL ONLY MOVE FROM OFF THE CALIFORNIA COAST MONDAY NIGHT TO REPOSITION THROUGH NEVADA FRIDAY...AS THE DE-AMPLIFICATION PROCESS BEGINS. LOW TEMPERATURES WILL GENERALLY FALL INTO THE 20S MONDAY NIGHT...AND THE 30S THEREAFTER. HIGH TEMPERATURES WILL GENERALLY BE IN THE 50S TUESDAY...RISE INTO THE 60S WEDNESDAY...THEN INTO THE 70S IN MANY PLACES THURSDAY AND FRIDAY. && .AVIATION...A MOISTURE-LADEN STORM SYSTEM WILL CONTINUE TO BRING WIDESPREAD RAIN AND SNOW SHOWERS THROUGH SATURDAY MORNING PRODUCING AREAS OF MVFR CONDITIONS. SHOWERS WILL TAPER OFF THIS EVENING AND THERE MAY BE A BRIEF BREAK AFTER THIS STORM EXITS. HOWEVER ANOTHER WAVE OF LOW PRESSURE WILL BRING MORE SHOWER ACTIVITY THROUGH SUNDAY MORNING. && .LKN WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 11 AM PDT THIS MORNING FOR RUBY MOUNTAINS/EAST HUMBOLDT RANGE...SOUTHERN LANDER COUNTY AND SOUTHERN EUREKA COUNTY...WHITE PINE COUNTY. WINTER WEATHER ADVISORY UNTIL 11 AM PDT THIS MORNING FOR SOUTH CENTRAL ELKO COUNTY. WINTER WEATHER ADVISORY UNTIL 11 AM PDT THIS MORNING ABOVE 5500 FEET FOR SOUTHWESTERN ELKO COUNTY. WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 PM PDT THIS AFTERNOON FOR NORTHWESTERN NYE COUNTY. && $$ 99/92/92
AREA FORECAST DISCUSSION
NWS ELKO NV
111 AM PDT SAT APR 26 2014 .SYNOPSIS...A STRONG LATE WINTER STORM WILL BRING WIDESPREAD RAIN AND SNOW TO NEVADA THROUGH SATURDAY MORNING. DRY WEATHER RETURNS BRIEFLY SATURDAY NIGHT...FOLLOWED BY MORE SNOW SHOWERS ACROSS NORTHERN NEVADA ON SUNDAY. DRIER AND WARMER WEATHER IS EXPECTED TO RETURN NEXT WEEK. && .SHORT TERM...TODAY THROUGH MONDAY. STRONG BUT PROGRESSIVE LATE WINTER/SPRING STORM SHAPING UP PRETTY MUCH AS PLANNED THIS MORNING. NAM/GFS/HRRR GUIDANCE IN EXCELLENT AGREEMENT THAT THE PEAK OF THIS WINTER WEATHER EVENT WILL OCCUR EARLY THIS MORNING, A FEW HOURS EITHER SIDE OF SUNRISE, ALONG A TONOPAH-EUREKA-NW WHITE PINE COUNTY-SE ELKO COUNTY LINE. HEAVY WET SNOW WILL FALL IN THIS CORRIDOR FOR SEVERAL HOURS FROM NOW THROUGH EARLY SATURDAY MORNING, WITH SEVERAL INCHES EXPECTED ESPECIALLY ON ELEVATED/VEGETATED SURFACES. IMPACTS WILL BE VERY ELEVATION DEPENDENT, TYPICAL OF LATE APRIL SNOWSTORMS, BUT PASSES AND SUMMITS ABOVE 5500 FEET WILL BE SLUSH/SNOW COVERED AND TREACHEROUS THIS MORNING. WILL ALLOW WINTER STORM WARNINGS TO CONTINUE AS PLANNED. A WILDCARD IN REGARD TO SNOWFALL AMOUNTS IS CONVECTION. LIGHTNING DETECTION AND IR SATELLITE CONTINUES TO INDICATE THUNDERSTORMS ROTATING NORTHWARD INTO WHITE PINE COUNTY. SNOWFALL RATES WILL BE ERRATIC AND BRIEFLY INTENSE IN THE WINTER STORM WARNING AREA THIS MORNING. SINCE THE SNOW IS OCCURRING ON A SATURDAY MORNING WITH NO SCHOOL AND LIMITED COMMUTING, IMPACTS WILL BE LIMITED, BUT NONETHELESS THESE INTENSE SNOWFALL RATES WILL LIKELY OVERCOME ANY WARM ROADWAYS AND MAKE TRAVEL DANGEROUS AT TIMES UNTIL THE MID-MORNING HOURS. REGARDING ELKO COUNTY...00Z NAM AND HRRR BOTH DEPICT A VERY TIGHT PRECIPITATION GRADIENT, WITH NW ELKO COUNTY GETTING LITTLE TO NO SNOW, AND HEAVY SNOW FALLING ON THE RUBY MOUNTAINS AND SE ELKO COUNTY. SNOWFALL FROM 00Z NAM SHOWS THIS TIGHT GRADIENT AND APPEARS VERY REASONABLE ON THE NW EDGE OF THE DEFORMATION BAND. EXPECTING ABOUT 1/2 INCH AT ELKO PROPER, 2-4 INCHES IN SPRING CREEK, AND NEAR 6 INCHES ADJACENT TO THE RUBY MOUNTAINS, SUCH AS JIGGS, LEE, AND LAMOILLE. WILL ALSO KEEP THE WINTER WEATHER ADVISORY GOING FOR ELEVATIONS ABOVE 5500 FEET FOR ELKO COUNTY THROUGH 11 AM. PRIMARY SURFACE LOW SW OF ELY EARLY THIS MORNING WILL RAPIDLY PULL EASTWARD THROUGH UTAH THIS MORNING, AND BE IN WYOMING BY MIDDAY. IN OTHER WORDS, SYSTEM IS QUITE PROGRESSIVE AND SNOW SHOWERS WILL TAPER OFF QUICKLY AFTER NOON. ALSO, IMPACTS TO ROADWAYS WILL END RAPIDLY AFTER 11 AM WITH THE LATE APRIL SUNSHINE, SO ALL WINTER HEADLINES WILL EXPIRE AT THAT TIME. NW FLOW AND COLD AIR ALOFT IS QUITE AGITATED THIS AFTERNOON, SO KEPT PLENTY OF SNOW/SNOW PELLET SHOWERS MENTIONED THIS AFTERNOON, BUT AMOUNTS WILL BE LIGHT. NW WINDS WILL BE STRONG AND GUSTY TODAY AS THE STORM SYSTEM DEPARTS. NW WINDS WILL AVERAGE 20-30 MPH WITH HIGHER GUSTS. BELIEVE WINDS WILL REMAIN BELOW ADVISORY CRITERIA, WITH THE EXCEPTION OF NW NYE COUNTY/TONOPAH. WIND GUSTS OF 50-55 MPH APPEAR LIKELY HERE TODAY, AND ISSUED A WIND ADVISORY FOR NW NYE COUNTY FROM 5 AM THROUGH 5 PM. A BRIEF BREAK OF DRY WEATHER TONIGHT, WITH LOWS NEAR FREEZING. SUNDAY...FINAL SHORTWAVE SKIRTS THROUGH NORTHERN NEVADA IN THE CHILLY NW FLOW. THIS SHOULD BE A PROLIFIC SNOW AND GRAUPEL SHOWER PRODUCER SUNDAY AFTERNOON MAINLY ACROSS ELKO COUNTY. INCREASED SHOWER COVERAGE IN THE GRIDS, BUT APPEARS TO BE A HIGH POP/LOW QPF SITUATION IN WHICH AMOUNTS WILL BE INSIGNIFICANT. STILL, VISIBILITY WILL BE SHARPLY REDUCED BY THESE PASSING CONVECTIVE SNOW SHOWERS. 00Z GFS DEPICTS LIFTED INDEX LESS THAN ZERO ACROSS ELKO COUNTY SUNDAY AFTERNOON, SO MENTIONED ISOLATED THUNDER AS WELL. SUNDAY WILL BE A DECIDEDLY UNPLEASANT "SPRING" DAY IN NEVADA WITH TEMPERATURES STUCK IN THE 40S MOST OF THE DAY, AND STRONG GUSTY WEST WINDS OF 20-30 MPH MAKING IT FEEL EVEN COLDER THAN THAT. SOME DECREASE IN CLOUDS SUNDAY NIGHT, ALLOWING FOR COLDER LOWS MONDAY MORNING IN THE MID TO UPPER 20S. MONDAY...DRY WEATHER RETURNS UNDER DRY NW FLOW. STILL QUITE CHILLY, WITH TEMPERATURES RUNNING ABOUT 10 DEGREES BELOW LATE APRIL NORMALS. TURNER .LONG TERM...MONDAY NIGHT THROUGH FRIDAY. THE PERIOD BEGINS WITH STRONG UPPER RIDGE BUILDING INTO THE REGION FOR DRY AND WARMER WEATHER. THE RIDGE WILL REACH ITS PEAK STRENGTH WEDNESDAY AND THURSDAY THEN BEGIN TO FLATTEN ON FRIDAY. TEMPS WILL BEGIN THE PERIOD SLIGHTLY BELOW NORMAL WITH HIGHS IN THE MID 50S TO THE MID 60S BUT WILL END THE PERIOD MUCH ABOVE NORMAL WITH HIGHS GENERALLY IN THE UPPER 60S TO THE MID 70S. && .AVIATION...STORM SYSTEM WILL BRING WIDESPREAD SHOWERS THROUGH SATURDAY MORNING WITH AREAS OF MVFR CONDITIONS. RAIN IS EXPECTED TO TURN OVER TO SNOW AT KTPH AROUND 04Z, AT KELY AROUND 10Z, AND KEKO AROUND 12Z BRINGING IFR CONDITIONS. && .LKN WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 11 AM PDT THIS MORNING FOR RUBY MOUNTAINS/EAST HUMBOLDT RANGE...SOUTHERN LANDER COUNTY AND SOUTHERN EUREKA COUNTY...WHITE PINE COUNTY. WINTER WEATHER ADVISORY UNTIL 11 AM PDT THIS MORNING FOR SOUTH CENTRAL ELKO COUNTY. WINTER WEATHER ADVISORY UNTIL 11 AM PDT THIS MORNING ABOVE 5500 FEET FOR SOUTHWESTERN ELKO COUNTY. WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 PM PDT THIS AFTERNOON FOR NORTHWESTERN NYE COUNTY. && $$ 99/92/92
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
324 AM EDT SAT APR 26 2014 .SYNOPSIS... A LOW PRESSURE SYSTEM WILL TRACK EAST ACROSS THE AREA TONIGHT BRINGING SOME SHOWERS. A FEW SHOWERS WILL LINGER SATURDAY AND SATURDAY NIGHT AS UPPER LEVEL LOW PRESSURE MOVES ACROSS THE AREA. HIGH PRESSURE OVER EASTERN CANADA WILL BRING A RETURN TO MAINLY DRY WEATHER SUNDAY AND MONDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 810 PM UPDATE... NUMEROUS LOPRES CNTRS ON SFC ANALYSIS THIS EVNG, ONE OVR UP OF MICHIGAN, ANOTHER OVR WRN NY AND YET ANOTHER DOWN OVR THE PIEDMONT OF NC. TWO AREAS OF SHOWERS AFFECTING CWA AT THIS TIME, WITH FIRST BATCH HVG MVD UP FM PA IN AREA OF ISENTROPIC LIFT. AREA OF SHOWERS MVG IN FM WRN NY ASSOC WITH FRONTAL BNDRY PUSHING EWRD. BACK EDGE OF RAIN SHIELD IS HANDLED BEAUTIFULLY BY LATEST HRRR AND EXPECT THIS TO BE ALONG THE I-81 CORRIDOR BY 07Z. CURRENT GRIDS REFLECT THIS WELL AND THE ONLY CHG NEEDED WAS TO RMV THUNDER MENTION THRU THE OVRNGT. NEAREST IN-CLOUD LIGHTNING STRIKES ARE DOWN ACRS THE VA CAPES WITH LATEST GUIDANCE KEEPING SHOWALTERS WELL ABV ZERO TONIGHT. EXPECT LO CLDS TO LINGER THRU THE MRNG HRS WITH A BRIEF POTENTIAL FOR PCLDY SKIES DRG THE MRNG HRS UNTIL PARENT H5 LOW DROPS ACRS NY STATE DRG THE DAY. WITH LOW-LVL MOISTURE RMNG, ESPECIALLY IN CNTR NY, SKIES WL CLD BACK UP BY NOON WITH POSSIBLE SHOWERS DVLPNG DRG THE DAY. PREV DISCUSSION BLO... MID TO HI CLOUDS ARE RAPIDLY INCREASING OVER CENTRAL NY AND NORTHEAST PA AS PER VISIBLE SATELLITE IMAGERY AS MOISTURE STREAMS EASTWARD ALOFT AHEAD OF NEXT UPPER LEVEL WAVE AND ASSOCIATED SURFACE SYSTEM. THIS UPPER LEVEL WAVE WAS SEEN WELL ON THE WATER VAPOR IMAGERY OVER OHIO AND WAS MOVG EAST/NORTHEAST. THERE WAS SIGNIFICANT MID TO HIGH LEVEL ISENTROPIC LIFT OR ALTERNATELY WARM AIR ADVECTION FOR THOSE WHO LIKE PRESSURE COORDINATES! WITH THIS, WAS ALSO SIGNIFICANT MOISTURE ADVECTION. THE END RESULT WAS INCREASING MID TO HI CLDS THAT WILL CONTINUE FOR THE REST OF THE AFTERNOON INTO THE EARLY EVENING HOURS. BY 00Z, THE POTENTIAL VORTICITY MAXIMUM WITH THE UPPER LEVEL WAVE WILL REACH WRN PA TO WRN NY AND PROVIDE SIGNIFICANT MID LEVEL LIFTG OF AIR THAT IS ALREADY RISING UP THE MOIST AND SATURATED ADIABATS. THIS WILL USHER IN A STEADY RAIN FROM SW TO NE ACRS C NY/NE PA BTWN ABT 22Z FROM SW STEUBEN CO TO WILKES BARRE TO 02Z IN THE RME AREA. THIS UPPER LEVEL POTENTIAL VORTICITY MAX WILL BECOME MORE STRETCHED AND ELONGATED IN TIME AS IT PASSES BY C NY/NE PA BY 6Z-10Z TONIGHT. THE RAIN WILL TAPER OFF AT THIS TIME. MODELS INDICATE SOME ELEVATED INSTABILITY LATER THIS EVENING WITH SHOWALTER INDICES DROPPING TO NEAR OR BELOW 0C. SO I HAVE ADDED A SLGHT CHC TO CHC OF THUNDER IN NE PA AND SC NY LATER IN THE EVENING. PRECIP WINDS DOWN LATE TONIGHT. FOR SATURDAY AM, THERE WILL BE PLENTY OF LOW CLOUDS AROUND AS WE ARE IN BETWEEN THE FIRST UPPER WAVE HEADING TO OUR NORTHEAST AND THE NEXT SIGNIFICANT UPPER LEVEL WAVE AND SIGNIFICANT SHOT OF COLD AIR ADVECTION COMING FROM THE GREAT LAKES REGION. HENCE I SEE LOTS OF LEFT OVER CLOUDS AROUND SAT AM. SHRA WILL DEVELOP BY SAT PM, AS BNDRY LAYER HEATING COMBINES WITH COOLING ALOFT ARRIVING WITH THIS NEXT SHOT OF COLD AIR ADVECTION AND LIFTG. HENCE I SEE PLENTY OF SHRA DEVELOP BY AFTERNOON. SAT WILL BE COOL AND BREEZY AS WELL. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... OPERATIONAL MODELS ARE IN GOOD AGREEMENT WITH THE FORECAST SCENARIO THROUGH THIS PERIOD. UPPER LEVEL LOW PRESSURE WILL DIG SOUTHEAST FROM THE NORTHERN GREAT LAKES TO SOUTHERN NEW ENGLAND SATURDAY NIGHT ACCOMPANIED BY SCATTERED SHOWERS ESPECIALLY NORTH OF THE NY/PA BORDER. A FEW SNOW FLAKES COULD MIX WITH THE RAIN LATER SATURDAY NIGHT ESPECIALLY OVER HIGHER ELEVATIONS AS TEMPERATURES WILL BECOME MARGINAL FOR SOME MIXED PRECIPITATION... BUT NO ACCUMULATIONS ARE EXPECTED. PRECIPITATION AMOUNTS SATURDAY NIGHT WILL BE LIGHT. LOW TEMPERATURES WILL BE IN THE 30S. SCATTERED SHOWERS... SPRINKLES OF MORNING FLURRIES MAY LINGER FOR AWHILE ON SUNDAY IN MOIST NNW FLOW PATTERN... ESPECIALLY OVER NY STATE. 850 MB TEMPERATURES DOWN AROUND -4 C WILL NOT BE COLD ENOUGH FOR ANY REAL LAKE ENHANCEMENT WITH LAKE ONTARIO TEMP STILL AROUND +2... SO MAIN CONCENTRATION OF SHOWERS MAY BE INLAND FROM THE FINGER LAKES TO THE SOUTHERN TIER OF NY... AS OPPOSED TO FARTHER NORTH NEAR LAKE ONTARIO. DRY AIR ASSOCIATED WITH HIGH PRESSURE OVER EASTERN CANADA WILL EVENTUALLY BREAK UP THE CLOUD COVER ACROSS THE AREA DURING THE AFTERNOON OR EVENING HOURS. TEMPERATURES SUNDAY WILL BE BELOW NORMAL WITH READINGS MAINLY IN THE 50S. AFTER A CLEAR CHILLY NIGHT SUNDAY NIGHT MONDAY WILL BE DRY WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES UNDER HIGH PRESSURE AT THE SURFACE AND ALOFT. THE NEXT CHC OF RAIN WILL BE LATER MONDAY NIGHT OR TUESDAY AS SURFACE THROUGH UPPER LEVEL LOW PRESSURE APPROACHES FROM THE SOUTHWEST AND ISENTROPIC LIFT DEVELOPS WITH INCREASING SW FLOW ALOFT. && .LONG TERM /MONDAY THROUGH FRIDAY/... 320 AM UPDATE...MODELS CONTINUE TO BE IN EXCELLENT AGREEMENT THROUGH THE MEDIUM RANGE AS AN UPPER LEVEL LOW AND ASSOCIATED SFC FEATURE SLOWLY TRACK FROM THE MID WEST NORTHEAST INTO THE GREAT LAKES REGION AND EVENTUALLY EASTERN CANADA. A PROLONGED PERIOD OF SHOWERS AND COOL WEATHER IS EXPECTED WITH THIS PATTERN. RAISED POPS INTO THE LIKELY CATEGORY FROM TUESDAY THROUGH WEDNESDAY NIGHT WITH CHANCE POPS CONTINUING THROUGH FRIDAY. PREVIOUS DISC... A STRONG HIGH PRESSURE RIDGE DEVELOPING OVER CENTRAL CANADA WILL FAVOR UPPER LEVEL LOW PRESSURE TO THE SOUTH-SOUTHEAST OVER THE CENTRAL AND EASTERN U.S. THROUGH THIS PERIOD. GFS/ECMWF HAVE BEEN ADVERTISING THIS PATTERN FOR QUITE SOME TIME NOW AND THERE IS HIGH CONFIDENCE FOR A GENERALLY UNSETTLED PERIOD OF WEATHER DURING THE MIDDLE AND LATE PART OF NEXT WEEK... ALTHOUGH THE DETAILS OF COURSE REMAIN VERY UNCLEAR AT THIS TIME RANGE. CURRENT FORECAST INDICATING AT LEAST A CHC OF SHOWERS EACH DAY FROM TUESDAY THROUGH FRIDAY APPEARS REASONABLE. TEMPERATURES LOOK TO BE AT LEAST A LITTLE BELOW NORMAL THROUGH THIS PERIOD... ALTHOUGH HOW FAR BELOW NORMAL WILL DEVELOP ON EXACTLY WHERE THE UPPER LOW DEVELOPS. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... SFC COLD FRONT HAS CLEARED MOST TAF SITES AND WILL PASS THROUGH KRME/KAVP DURING THE NEXT COUPLE OF HOURS. BEHIND BOUNDARY WIDESPREAD IFR CIGS ARE EXPECTED UNTIL 12Z EXCEPT FOR KAVP. BETWEEN 12Z-16Z CONDITIONS WILL GENERALLY IMPROVE TO VFR BUT A MID LEVEL SHORT WAVE WILL PRODUCE SCATTERED SHOWERS DURING THE AFTERNOON WITH BRIEF MVFR CONDITIONS POSSIBLE AT ALL SITES BUT KELM/KAVP. THIS EVENING COLD NORTHWEST UPSLOPE FLOW WILL RESULT IN WIDESPREAD MVFR CIGS EXCEPT VFR AT KELM/KAVP. WINDS BECOMING WESTERLY EARLY THIS MORNING AT 10-12 KNOTS THEN INCREASING BY MID MORNING TO 12-15 KNOTS WITH GUSTS 20-25 KNOTS. WINDS DECREASING TO AROUND 10 KNOTS BY 00Z. OUTLOOK... SUN-MON...VFR. TUE AND WED...RESTRICTIONS POSSIBLE IN RAIN SHOWERS. && .FIRE WEATHER... RAINFALL HAS MOVED INTO NORTHEAST PENNSYLVANIA THIS EVENING WITH AMOUNTS RANGING FROM A FEW HUNDREDTHS OF AN INCH TO A TENTH OF AN INCH. WITH SHOWERS EXPECTED TONIGHT AND AGAIN SATURDAY, NO THREAT FOR FIRE WEATHER CONDITIONS EXIST THROUGH THE WEEKEND. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MSE/TAC NEAR TERM...DJN/PVN SHORT TERM...MSE LONG TERM...MSE/RRM AVIATION...RRM FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
158 AM EDT SAT APR 26 2014 .SYNOPSIS... A LOW PRESSURE SYSTEM WILL TRACK EAST ACROSS THE AREA TONIGHT BRINGING SOME SHOWERS. A FEW SHOWERS WILL LINGER SATURDAY AND SATURDAY NIGHT AS UPPER LEVEL LOW PRESSURE MOVES ACROSS THE AREA. HIGH PRESSURE OVER EASTERN CANADA WILL BRING A RETURN TO MAINLY DRY WEATHER SUNDAY AND MONDAY. && .NEAR TERM /THROUGH TODAY/... 810 PM UPDATE... NUMEROUS LOPRES CNTRS ON SFC ANALYSIS THIS EVNG, ONE OVR UP OF MICHIGAN, ANOTHER OVR WRN NY AND YET ANOTHER DOWN OVR THE PIEDMONT OF NC. TWO AREAS OF SHOWERS AFFECTING CWA AT THIS TIME, WITH FIRST BATCH HVG MVD UP FM PA IN AREA OF ISENTROPIC LIFT. AREA OF SHOWERS MVG IN FM WRN NY ASSOC WITH FRONTAL BNDRY PUSHING EWRD. BACK EDGE OF RAIN SHIELD IS HANDLED BEAUTIFULLY BY LATEST HRRR AND EXPECT THIS TO BE ALONG THE I-81 CORRIDOR BY 07Z. CURRENT GRIDS REFLECT THIS WELL AND THE ONLY CHG NEEDED WAS TO RMV THUNDER MENTION THRU THE OVRNGT. NEAREST IN-CLOUD LIGHTNING STRIKES ARE DOWN ACRS THE VA CAPES WITH LATEST GUIDANCE KEEPING SHOWALTERS WELL ABV ZERO TONIGHT. EXPECT LO CLDS TO LINGER THRU THE MRNG HRS WITH A BRIEF POTENTIAL FOR PCLDY SKIES DRG THE MRNG HRS UNTIL PARENT H5 LOW DROPS ACRS NY STATE DRG THE DAY. WITH LOW-LVL MOISTURE RMNG, ESPECIALLY IN CNTR NY, SKIES WL CLD BACK UP BY NOON WITH POSSIBLE SHOWERS DVLPNG DRG THE DAY. PREV DISCUSSION BLO... MID TO HI CLOUDS ARE RAPIDLY INCREASING OVER CENTRAL NY AND NORTHEAST PA AS PER VISIBLE SATELLITE IMAGERY AS MOISTURE STREAMS EASTWARD ALOFT AHEAD OF NEXT UPPER LEVEL WAVE AND ASSOCIATED SURFACE SYSTEM. THIS UPPER LEVEL WAVE WAS SEEN WELL ON THE WATER VAPOR IMAGERY OVER OHIO AND WAS MOVG EAST/NORTHEAST. THERE WAS SIGNIFICANT MID TO HIGH LEVEL ISENTROPIC LIFT OR ALTERNATELY WARM AIR ADVECTION FOR THOSE WHO LIKE PRESSURE COORDINATES! WITH THIS, WAS ALSO SIGNIFICANT MOISTURE ADVECTION. THE END RESULT WAS INCREASING MID TO HI CLDS THAT WILL CONTINUE FOR THE REST OF THE AFTERNOON INTO THE EARLY EVENING HOURS. BY 00Z, THE POTENTIAL VORTICITY MAXIMUM WITH THE UPPER LEVEL WAVE WILL REACH WRN PA TO WRN NY AND PROVIDE SIGNIFICANT MID LEVEL LIFTG OF AIR THAT IS ALREADY RISING UP THE MOIST AND SATURATED ADIABATS. THIS WILL USHER IN A STEADY RAIN FROM SW TO NE ACRS C NY/NE PA BTWN ABT 22Z FROM SW STEUBEN CO TO WILKES BARRE TO 02Z IN THE RME AREA. THIS UPPER LEVEL POTENTIAL VORTICITY MAX WILL BECOME MORE STRETCHED AND ELONGATED IN TIME AS IT PASSES BY C NY/NE PA BY 6Z-10Z TONIGHT. THE RAIN WILL TAPER OFF AT THIS TIME. MODELS INDICATE SOME ELEVATED INSTABILITY LATER THIS EVENING WITH SHOWALTER INDICES DROPPING TO NEAR OR BELOW 0C. SO I HAVE ADDED A SLGHT CHC TO CHC OF THUNDER IN NE PA AND SC NY LATER IN THE EVENING. PRECIP WINDS DOWN LATE TONIGHT. FOR SATURDAY AM, THERE WILL BE PLENTY OF LOW CLOUDS AROUND AS WE ARE IN BETWEEN THE FIRST UPPER WAVE HEADING TO OUR NORTHEAST AND THE NEXT SIGNIFICANT UPPER LEVEL WAVE AND SIGNIFICANT SHOT OF COLD AIR ADVECTION COMING FROM THE GREAT LAKES REGION. HENCE I SEE LOTS OF LEFT OVER CLOUDS AROUND SAT AM. SHRA WILL DEVELOP BY SAT PM, AS BNDRY LAYER HEATING COMBINES WITH COOLING ALOFT ARRIVING WITH THIS NEXT SHOT OF COLD AIR ADVECTION AND LIFTG. HENCE I SEE PLENTY OF SHRA DEVELOP BY AFTERNOON. SAT WILL BE COOL AND BREEZY AS WELL. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... OPERATIONAL MODELS ARE IN GOOD AGREEMENT WITH THE FORECAST SCENARIO THROUGH THIS PERIOD. UPPER LEVEL LOW PRESSURE WILL DIG SOUTHEAST FROM THE NORTHERN GREAT LAKES TO SOUTHERN NEW ENGLAND SATURDAY NIGHT ACCOMPANIED BY SCATTERED SHOWERS ESPECIALLY NORTH OF THE NY/PA BORDER. A FEW SNOW FLAKES COULD MIX WITH THE RAIN LATER SATURDAY NIGHT ESPECIALLY OVER HIGHER ELEVATIONS AS TEMPERATURES WILL BECOME MARGINAL FOR SOME MIXED PRECIPITATION... BUT NO ACCUMULATIONS ARE EXPECTED. PRECIPITATION AMOUNTS SATURDAY NIGHT WILL BE LIGHT. LOW TEMPERATURES WILL BE IN THE 30S. SCATTERED SHOWERS... SPRINKLES OF MORNING FLURRIES MAY LINGER FOR AWHILE ON SUNDAY IN MOIST NNW FLOW PATTERN... ESPECIALLY OVER NY STATE. 850 MB TEMPERATURES DOWN AROUND -4 C WILL NOT BE COLD ENOUGH FOR ANY REAL LAKE ENHANCEMENT WITH LAKE ONTARIO TEMP STILL AROUND +2... SO MAIN CONCENTRATION OF SHOWERS MAY BE INLAND FROM THE FINGER LAKES TO THE SOUTHERN TIER OF NY... AS OPPOSED TO FARTHER NORTH NEAR LAKE ONTARIO. DRY AIR ASSOCIATED WITH HIGH PRESSURE OVER EASTERN CANADA WILL EVENTUALLY BREAK UP THE CLOUD COVER ACROSS THE AREA DURING THE AFTERNOON OR EVENING HOURS. TEMPERATURES SUNDAY WILL BE BELOW NORMAL WITH READINGS MAINLY IN THE 50S. AFTER A CLEAR CHILLY NIGHT SUNDAY NIGHT MONDAY WILL BE DRY WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES UNDER HIGH PRESSURE AT THE SURFACE AND ALOFT. THE NEXT CHC OF RAIN WILL BE LATER MONDAY NIGHT OR TUESDAY AS SURFACE THROUGH UPPER LEVEL LOW PRESSURE APPROACHES FROM THE SOUTHWEST AND ISENTROPIC LIFT DEVELOPS WITH INCREASING SW FLOW ALOFT. && .LONG TERM /MONDAY THROUGH FRIDAY/... A STRONG HIGH PRESSURE RIDGE DEVELOPING OVER CENTRAL CANADA WILL FAVOR UPPER LEVEL LOW PRESSURE TO THE SOUTH-SOUTHEAST OVER THE CENTRAL AND EASTERN U.S. THROUGH THIS PERIOD. GFS/ECMWF HAVE BEEN ADVERTISING THIS PATTERN FOR QUITE SOME TIME NOW AND THERE IS HIGH CONFIDENCE FOR A GENERALLY UNSETTLED PERIOD OF WEATHER DURING THE MIDDLE AND LATE PART OF NEXT WEEK... ALTHOUGH THE DETAILS OF COURSE REMAIN VERY UNCLEAR AT THIS TIME RANGE. CURRENT FORECAST INDICATING AT LEAST A CHC OF SHOWERS EACH DAY FROM TUESDAY THROUGH FRIDAY APPEARS REASONABLE. TEMPERATURES LOOK TO BE AT LEAST A LITTLE BELOW NORMAL THROUGH THIS PERIOD... ALTHOUGH HOW FAR BELOW NORMAL WILL DEVELOP ON EXACTLY WHERE THE UPPER LOW DEVELOPS. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... SFC COLD FRONT HAS CLEARED MOST TAF SITES AND WILL PASS THROUGH KRME/KAVP DURING THE NEXT COUPLE OF HOURS. BEHIND BOUNDARY WIDESPREAD IFR CIGS ARE EXPECTED UNTIL 12Z EXCEPT FOR KAVP. BETWEEN 12Z-16Z CONDITIONS WILL GENERALLY IMPROVE TO VFR BUT A MID LEVEL SHORT WAVE WILL PRODUCE SCATTERED SHOWERS DURING THE AFTERNOON WITH BRIEF MVFR CONDITIONS POSSIBLE AT ALL SITES BUT KELM/KAVP. THIS EVENING COLD NORTHWEST UPSLOPE FLOW WILL RESULT IN WIDESPREAD MVFR CIGS EXCEPT VFR AT KELM/KAVP. WINDS BECOMING WESTERLY EARLY THIS MORNING AT 10-12 KNOTS THEN INCREASING BY MID MORNING TO 12-15 KNOTS WITH GUSTS 20-25 KNOTS. WINDS DECREASING TO AROUND 10 KNOTS BY 00Z. OUTLOOK... SUN-MON...VFR. TUE AND WED...RESTRICTIONS POSSIBLE IN RAIN SHOWERS. && .FIRE WEATHER... RAINFALL HAS MOVED INTO NORTHEAST PENNSYLVANIA THIS EVENING WITH AMOUNTS RANGING FROM A FEW HUNDREDTHS OF AN INCH TO A TENTH OF AN INCH. WITH SHOWERS EXPECTED TONIGHT AND AGAIN SATURDAY, NO THREAT FOR FIRE WEATHER CONDITIONS EXIST THROUGH THE WEEKEND. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MSE/TAC NEAR TERM...DJN/PVN SHORT TERM...MSE LONG TERM...MSE AVIATION...RRM FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
933 PM CDT SUN APR 27 2014 .UPDATE... ISSUED AT 933 PM CDT SUN APR 27 2014 FORECAST IS UNFOLDING AS EXPECTED. THE ONLY UPDATE WILL BE TO INDICATE A BRIEF BREAK IN ACTIVITY WITH 30% POPS. THE REGION WILL REMAIN WITHIN THE TROWAL (WHICH WILL GRADUALLY LIFT NORTH OVERNIGHT). WE KNOW THAT RAIN WILL OCCUR WITHIN THIS FEATURE...AND ALL AREAS WILL RECEIVE RAINFALL. THE HARD PART IS ATTEMPTING TO FORECAST EXACTLY WHEN AND WHERE WAVES ROTATING AROUND THE MAIN UPPER LOW WILL INFLUENCE AREAS WITHIN THE TROWAL. THE HRRR DID A GOOD JOB LAST NIGHT...AND WILL FOLLOW AS GUIDANCE FOR TONIGHT. THE RAIN ACROSS THE SOUTHERN FA WILL LIFT NORTH OVERNIGHT...AND ANTICIPATE A BREAK IN ACTIVITY ONCE THIS ACTIVITY MOVES TO THE NORTH. ADJUSTED POPS FOR THIS THINKING. THE NEXT WAVE...OR AREA OF FORCING...IS ASSOCIATED WITH THE ACTIVITY JUST ENTERING SOUTHERN IOWA. THIS ACTIVITY SHOULD EXPAND TO THE NORTHWEST OVERNIGHT...ENTERING WEST CENTRAL MINNESOTA 10Z-12Z...THEN EXPANDING INTO MUCH OF THE FA AFTER 12Z MONDAY MORNING (CONTINUING THROUGH MUCH OF THE DAY...STARTING TO DRY FROM THE NORTHEAST BY LATE AFTERNOON). && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 343 PM CDT SUN APR 27 2014 CHALLENGES INCLUDE WINDS LATE THIS AFTERNOON AND EVENING AND THEN PRECIP CHANCES/TYPE/AMOUNTS THROUGH THE REMAINDER OF THE FORECAST PERIOD. WILL USE RAP/HRRR FOR THE NEXT 6 TO 12 HOURS AND THEN TRANSITION TO A GLOBAL MODEL BLEND THEREAFTER AS GFS/NAM/ECMWF/ GEM ARE IN RELATIVELY GOOD AGREEMENT. IN THE NEAR TERM...WILL LET WIND ADVISORY CONTINUE UNTIL 7 PM CDT. MOST AREAS WON/T HIT CRITERIA...BUT FINALLY STARTING TO SEE SOME MORE WIDESPREAD OBSERVATIONS AT OR ABOVE 30 MPH. 20 UTC WATER VAPOR LOOP SHOWS PRIMARY VORTICITY MAXIMA ACROSS WESTERN KS WITH A STRONG SHORT-WAVE ROTATING OUT OF ITS BASE. STRONG WARM AIR AND MOISTURE ADVECTION (PWATS TO ONE INCH) ALONG THE 850 HPA SFC THIS EVENING AND OVERNIGHT...COMBINED WITH DIVERGENT FLOW ALOFT WILL RESULT IN INCREASING SHOWERS MOVING FROM SOUTH TO NORTH. ADDED THUNDER BACK INTO THE FORECAST ACROSS THE SOUTH THIS EVENING WITH ISOLATED LIGHTNING STRIKES ALONG THE ND/SD BORDER. INSTABILITY IS MINIMAL...BUT SPC MESOANALYSIS SHOWS A COUPLE HUNDRED JOULES OF MOST UNSTABLE CAPE. THERMAL PROFILES WARM ENOUGH TONIGHT FOR ALL RAIN...BUT COULD SEE A FEW FLAKES IN THE MIX. WILL LIFT CATEGORICAL POPS TO THE NORTH TONIGHT AND MONDAY. MONDAY WILL BE CLOUDY AND COOL WITH PERIODS OF LIGHT TO MODERATE RAIN SHOWERS. TEMPERATURES WILL RISE INTO THE UPPER 30S TO MID 40S WITH PERSISTENT BREEZY EASTERLY WIND. 850 HPA TEMPERATURES BEGIN TO FALL BELOW FREEZING MONDAY NIGHT WITH MOST OF THE COLUMN BELOW 0 C BY TUESDAY MORNING EXCEPT THE NEAR SFC LAYER. PTYPE WILL DEPEND HEAVILY ON SFC TEMPERATURES...BUT WITH FORECAST VALUES PLUS OR MINUS A FEW DEGREES AROUND FREEZING MONDAY NIGHT...WILL KEEP A RAIN/SNOW MIX IN THE WEATHER GRIDS. NOT REALLY EXPECTING MUCH ACCUMULATION AS MOST SNOW THAT DOES FALL SHOULD MELT ON CONTACT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 343 PM CDT SUN APR 27 2014 STRONG DRYING WILL WORK ITS WAY SOUTH ON TUESDAY AS THE LOW PRESSURE SYSTEM SCOOTS ACROSS IA INTO WI. SHOULD SEE A BREAK IN PRECIP...ESPECIALLY FOR THE CENTRAL AND NORTHERN FORECAST AREA. COULD EVEN SEE SOME PEAKS OF SUN. PTYPE SHOULD BE MOSTLY RAIN WITH HIGHS RISING INTO THE MID TO UPPER 40S. WINDS WILL REMAIN BREEZY AND SHIFT TO THE NORTH. WRAP AROUND PRECIP WILL RETURN WEDNESDAY AS THE LOW WOBBLES ACROSS WI WITH A GREATER CHANCE FOR A RAIN/SNOW MIX OR EVEN ALL SNOW AT TIMES GIVEN A SATURATED SUB-FREEZING COLUMN. PTYPE WILL AGAIN DEPEND ON SFC TEMPERATURES WITH MINIMAL ACCUMULATIONS. WHEN ALL IS SAID AND DONE...LIQUID ACCUMULATIONS OVER THE 2 TO 3 DAY PERIOD WILL BE 1 TO 2 INCHES WITH LOCALLY HIGHER AMOUNTS IN HEAVIER SHOWERS OR THUNDERSTORMS. ANY SNOW ACCUMULATION SHOULD BE CONFINED MAINLY TO THE HIGHER TERRAIN ON EITHER SIDE OF THE VALLEY BUT ONLY AN INCH OR LESS. UPPER LOW AND SURFACE LOW WILL REMAIN OVER THE GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY WITH NORTH WINDS AND SPOTTY RAIN SHOWERS ALONG WITH CONTINUED WELL BELOW NORMAL TEMPERATURES. 12Z ECMWF/GFS ALL INDICATE 500 MB TROUGH TO REMAIN IN PLACE WITH NEXT SHORT WAVE DROPPING SOUTH INTO THE NRN PLAINS FRIDAY NIGHT-SATURDAY WITH ANOTHER CHANCE OF SHOWERS. NO HEAVY RAINFALL THIS PERIOD BUT AT LEAST A CHANCE FOR SHOWERS EACH DAY AND TEMPS REMAIN BELOW AVERAGE INTO THE WEEKEND. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 645 PM CDT SUN APR 27 2014 CONDITIONS ARE EXPECTED TO DETERIORATE THROUGH THE OVERNIGHT HOURS...BUT BY HOW MUCH REMAINS THE QUESTION. LOW LEVEL EASTERLY FLOW FROM A DRY AIRMASS WILL REMAIN THROUGH MUCH OF THE TAF PERIOD...PUTTING INTO QUESTION EXACTLY HOW LOW CIGS WILL BECOME. AS THE MORE STEADY RAIN MOVES INTO EACH SITE...EXPECT CIGS AND VSBY TO LOWER...BUT NOT AS MUCH AS MOS GUIDANCE SUGGESTS. ATTEMPTED TO FOLLOW MORE OF THE GRIDDED RAP GUIDANCE FOR CIGS...AND THE RAP/HRRR FOR RAIN CHANCES. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...TG SHORT TERM...ROGERS LONG TERM...ROGERS/RIDDLE AVIATION...TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1131 AM CDT SAT APR 26 2014 .UPDATE... ISSUED AT 1131 AM CDT SAT APR 26 2014 QUICK UPDATE TO ISSUE A WIND ADVISORY FOR THE SOUTHWEST AND PARTS OF SOUTH CENTRAL THROUGH MUCH OF THIS EVENING. WINDS HAVE INCREASED IN THE SOUTHWEST...AND WERE HIGHER THAN PREVIOUSLY FORECAST. ALSO...LATEST GUIDANCE INDICATES STRONGER WINDS AND PERSISTING INTO THE EVENING. UPDATE ISSUED AT 940 AM CDT SAT APR 26 2014 NARROW BAND OF SHOWERS NOW HAD ADVANCED NORTHWARD TO WILLISTON...MCLEAN COUNTY (NORTH OF LAKE SAKAKAWEA) TO BETWEEN BISMARCK AND JAMESTOWN. THE BISMARCK AIRPORT RECORDED 0.07 INCHES OF RAIN AS THE PRECIP BAND WENT THROUGH. THE BAND CONTINUES LIFTING NORTHWARD AND EXPECT A FEW HUNDREDTHS OF AN INCH TO PERHAPS A TENTH OF AN INCH OF RAIN MOST AREAS. ADJUSTED TIMING OF PRECIPITATION ACCORDINGLY. BY EARLY AFTERNOON THE PRECIPITATION BAND SHOULD BE MAINLY NORTH OF THE CANADIAN BORDER...WITH THE SOUTHEASTERN PORTION DISSIPATING. OTHERWISE FORECAST ON TRACK - MINOR HOURLY ADJUSTMENTS FOR WIND AND TEMPERATURES. UPDATE ISSUED AT 642 AM CDT SAT APR 26 2014 NARROW BAND OF SHOWERS FROM WEST CENTRAL INTO SOUTH CENTRAL NORTH DAKOTA CONTINUES TO LIFT NORTH THIS MORNING. ONLY SOME SLIGHT MODIFICATIONS TO THE CURRENT HRRR POP PLACEMENT TODAY. ALSO BUMPED UP SKY COVER THROUGH THE MORNING SOUTHWEST BASED ON LATEST SATELLITE IMAGERY. OTHERWISE CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 353 AM CDT SAT APR 26 2014 THE HIGHLIGHT OF THE SHORT TERM IS PRECIPITATION POTENTIAL. FOR TODAY...THE HRRR HAS HAD A GOOD HANDLE ON THE NARROW BAND OF RAIN SHOWERS MOVING INTO SOUTHWEST NORTH DAKOTA AS OF 0830 UTC WITH THE LEADING SHORTWAVE. THUS...WILL FOLLOW THE 07 UTC HRRR AND ITS PARENT RAP FOR POPS THIS MORNING AND INTO THE AFTERNOON. THESE SOLUTIONS ARE IN AGREEMENT WITH THE 00 UTC 4 KM WRF AND LARGER SCALE DETERMINISTIC GUIDANCE WHICH QUICKLY MOVE THE RAIN SHOWERS TO THE INTERNATIONAL BORDER BY EARLY AFTERNOON. THUS...AFTER THE NARROW BAND OF SHOWERS PASS...THE DAY SHOULD BE PRECIPITATION FREE FOR NEARLY ALL OF THE CWA. IN REGARDS TO WINDS FOR TODAY...EXPECT WIDESPREAD EAST-SOUTHEAST GUSTS OF 30-35 KTS FOR MOST AREAS. HOWEVER...A LOW LEVEL INVERSION IN WARM AIR ADVECTION WILL LIMIT THE TRANSFER OF HIGHER MOMENTUM AND FORGO THE NEED FOR A WIND ADVISORY. FOR TONIGHT...SURFACE LOW PRESSURE CONTINUES TO DEEPEN ACROSS WESTERN NEBRASKA...AS THE OVERALL SYSTEM BECOMES NEARLY VERTICALLY STACKED LATE TONIGHT AS THE POTENT UPPER LEVEL WAVE PROPAGATES ONTO THE PLAINS. RESULTING MOISTURE TRANSPORT INCREASES ACROSS THE NORTHERN PLAINS...WITH RAIN SHOWER COVERAGE INCREASING AFTER 06 UTC ACROSS WESTERN NORTH DAKOTA IN THE VICINITY OF THE INVERTED TROUGH EXTENDING INTO EASTERN MONTANA...AND ACROSS SOUTHERN NORTH DAKOTA IN LOW LEVEL WARM AIR ADVECTION. THE BULK OF ELEVATED INSTABILITY TONIGHT REMAINS IN SOUTH DAKOTA...HOWEVER AN EMBEDDED THUNDERSTORM IS POSSIBLE ACROSS FAR SOUTH CENTRAL NORTH DAKOTA . .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 329 AM CDT SAT APR 26 2014 THE MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE THE STRONG SPRING STORM SYSTEM AFFECTING ALL OF WESTERN AND CENTRAL NORTH DAKOTA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE TRACK OF THE SURFACE AND UPPER LEVEL FEATURES THROUGH TUESDAY...WITH DIFFERENCES INCREASING THEREAFTER. STILL SOME DIFFERENCES IN QPF PATTERN THROUGH THE EVOLUTION OF THE SYSTEM WITH THE GFS BEING THE DRIEST ACROSS PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. ALL MODELS HOWEVER ARE PINPOINTING THE FAR SOUTHWEST WITH SOME OF THE HIGHEST RAINFALL AMOUNTS. STRONG SHORTWAVE JUST MOVING ONTO THE SOUTHERN CALIFORNIA COAST WITH AN UPPER LEVEL LOW CLOSING OFF JUST TO ITS NORTH. BROAD FETCH OF MOISTURE IN SOUTHWEST UPPER FLOW INTO THE NORTHERN PLAINS...SETTING THE STAGE FOR AN EXTENDED PERIOD OF RAINY WEATHER. BY SUNDAY MORNING THE UPPER LOW IS PROGGED TO BE OVER EASTERN COLORADO WITH A RAPIDLY DEEPENING SURFACE SYSTEM OVER THE CENTRAL PLAINS. THE INITIAL SURGE OF ENERGY MOVES INTO THE AREA LATE TONIGHT INTO SUNDAY MORNING. ALTHOUGH BEST ELEVATED INSTABILITY REMAINS JUST TO OUR SOUTH...SYSTEM IS STRONG ENOUGH THAT A MENTION OF THUNDER SEEMED WARRANTED SUNDAY MORNING. BEST PRECIPITATION CHANCES DURING THE DAY WILL BE OVER THE SOUTHWEST HALF OF THE CWA...AND THERE MAY BE PERIODS OF NO RAIN AS WELL AS DRIER AIR WRAPS AROUND THE STACKED SYSTEM. ANOTHER STRONG IMPULSE LIFTS THROUGH THE AREA SUNDAY NIGHT AS THE UPPER LOW REACHES ITS FARTHEST POINT NORTH BEFORE WOBBLING BACK SOUTH ON MONDAY. BY THIS TIME CHANCES OF CONVECTION WILL BE MINIMAL AS COOLER AIR GETS PULLED INTO THE SYSTEM. THE FAR NORTH AND HIGHER ELEVATIONS IN THE FAR WEST COULD SEE PERIODS OF SNOW LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING. LATEST MODEL RUNS ARE A LITTLE COOLER IN THE WEST SO WILL NEED TO MONITOR FOR SOME LIGHT ACCUMULATING SNOWS IN THE FAR WEST...BUT AT THIS TIME ITS TOO EARLY FOR ANY MENTION OF ACCUMULATIONS. PRECIPITATION BEGINS TO WANE ON MONDAY AS THE LOW DROPS SOUTH. ALTHOUGH LOW LEVEL FORCING WILL BE ON THE DECREASE...SYNOPTIC SCALE FORCING WILL REMAIN THROUGH TUESDAY AS WE REMAIN UNDER THE CYCLONIC FLOW OF THE UPPER LEVEL LOW. THUS LIKELY POPS REMAIN MONDAY INTO MONDAY NIGHT...WITH HIGH CHANCE POPS TUESDAY. AGAIN WE WILL SEE THE POSSIBILITY OF SNOW MONDAY NIGHT INTO TUESDAY MORNING...AND LIGHT ACCUMULATIONS ARE CERTAINLY NOT OUT OF THE QUESTION. THE UPPER LOW LIFTS BACK NORTHWARD TUESDAY NIGHT INTO WEDNESDAY WITH ANOTHER WAVE OF MOISTURE SWINGING EAST TO WEST ACROSS THE AREA ON WEDNESDAY BRINGING A CHANCE OF RAIN OR SNOW SHOWERS. THE SYSTEM FINALLY EXITS THE ARE LATE IN THE WORK WEEK...WITH ANOTHER IMPULSE IN A NORTHWEST FLOW PATTERN POSSIBLE BY NEXT WEEKEND. ALL IN ALL A WET AND COOL PERIOD IS IN STORE THROUGH MOST OF THE EXTENDED PERIOD. WILL ISSUE A HYDROLOGIC STATEMENT MENTIONING THE POSSIBILITY OF FLOODING DUE TO AN EXTENDED PERIOD OF RAIN. WPC DEPICTS PORTIONS OF THE SOUTHWEST WITH A SLIGHT CHANCE OF EXCESSIVE RAINFALL 12Z SUNDAY THROUGH 12Z MONDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 642 AM CDT SAT APR 26 2014 A NARROW BAND OF LIGHT RAIN SHOWERS HAS MOVED INTO WESTERN INTO SOUTH CENTRAL NORTH DAKOTA AS OF 1130 UTC...AND WILL CONTINUE TO MOVE NORTH-NORTHEAST THROUGH THE MORNING. RAIN SHOWER ACTIVITY IN THE AFTERNOON IS EXPECTED TO LARGELY REMAIN NORTH OF KISN AND KMOT. STRONG EAST-SOUTHEAST WINDS WITH GUSTS OF 30-35 KTS ARE EXPECTED FOR MUCH OF THE AREA TODAY. A LARGE STORM SYSTEM WILL BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA SATURDAY NIGHT...WITH CONDITIONS TRENDING TOWARDS MVFR/IFR IN STRATUS AND RAIN. && .HYDROLOGY... ISSUED AT 353 AM CDT SAT APR 26 2014 ISSUED A HYDROLOGIC OUTLOOK...ESF...FOR WESTERN NORTH DAKOTA REGARDING THE UPCOMING HEAVY RAIN EVENT AND POTENTIAL IMPACTS. AS OF NOW...THE 00 UTC DETERMINISTIC SUITE REMAINS IN SOME DISAGREEMENT ON THE PLACEMENT OF THE HEAVIEST QPF AXIS. THIS HAS SIGNIFICANT IMPACTS IN BASIN HYDROLOGIC RESPONSE. FURTHERMORE...THE REMOVAL OF FROST FROM THE GROUND AND RECENT DRY WEATHER PLACES ADDITIONAL UNCERTAINTY IN HOW MUCH WATER THE SOILS WILL BE ABLE TO HOLD. THAT SAID...RIVER AND STREAM RISES...POTENTIALLY ABOVE FLOOD STAGE...ARE POSSIBLE. HOWEVER...WHICH SPECIFIC WATERWAYS RESPOND THE MOST IS HIGHLY DEPENDENT ON QPF PLACEMENT. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 10 PM CDT /9 PM MDT/ THIS EVENING FOR NDZ017>020-031>035-040>047-050. && $$ UPDATE...JV SHORT TERM...AYD LONG TERM...TWH AVIATION...AYD HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
940 AM CDT SAT APR 26 2014 .UPDATE... ISSUED AT 940 AM CDT SAT APR 26 2014 NARROW BAND OF SHOWERS NOW HAD ADVANCED NORTHWARD TO WILLISTON...MCLEAN COUNTY (NORTH OF LAKE SAKAKAWEA) TO BETWEEN BISMARCK AND JAMESTOWN. THE BISMARCK AIRPORT RECORDED 0.07 INCHES OF RAIN AS THE PRECIP BAND WENT THROUGH. THE BAND CONTINUES LIFTING NORTHWARD AND EXPECT A FEW HUNDREDTHS OF AN INCH TO PERHAPS A TENTH OF AN INCH OF RAIN MOST AREAS. ADJUSTED TIMING OF PRECIPITATION ACCORDINGLY. BY EARLY AFTERNOON THE PRECIPITATION BAND SHOULD BE MAINLY NORTH OF THE CANADIAN BORDER...WITH THE SOUTHEASTERN PORTION DISSIPATING. OTHERWISE FORECAST ON TRACK - MINOR HOURLY ADJUSTMENTS FOR WIND AND TEMPERATURES. UPDATE ISSUED AT 642 AM CDT SAT APR 26 2014 NARROW BAND OF SHOWERS FROM WEST CENTRAL INTO SOUTH CENTRAL NORTH DAKOTA CONTINUES TO LIFT NORTH THIS MORNING. ONLY SOME SLIGHT MODIFICATIONS TO THE CURRENT HRRR POP PLACEMENT TODAY. ALSO BUMPED UP SKY COVER THROUGH THE MORNING SOUTHWEST BASED ON LATEST SATELLITE IMAGERY. OTHERWISE CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 353 AM CDT SAT APR 26 2014 THE HIGHLIGHT OF THE SHORT TERM IS PRECIPITATION POTENTIAL. FOR TODAY...THE HRRR HAS HAD A GOOD HANDLE ON THE NARROW BAND OF RAIN SHOWERS MOVING INTO SOUTHWEST NORTH DAKOTA AS OF 0830 UTC WITH THE LEADING SHORTWAVE. THUS...WILL FOLLOW THE 07 UTC HRRR AND ITS PARENT RAP FOR POPS THIS MORNING AND INTO THE AFTERNOON. THESE SOLUTIONS ARE IN AGREEMENT WITH THE 00 UTC 4 KM WRF AND LARGER SCALE DETERMINISTIC GUIDANCE WHICH QUICKLY MOVE THE RAIN SHOWERS TO THE INTERNATIONAL BORDER BY EARLY AFTERNOON. THUS...AFTER THE NARROW BAND OF SHOWERS PASS...THE DAY SHOULD BE PRECIPITATION FREE FOR NEARLY ALL OF THE CWA. IN REGARDS TO WINDS FOR TODAY...EXPECT WIDESPREAD EAST-SOUTHEAST GUSTS OF 30-35 KTS FOR MOST AREAS. HOWEVER...A LOW LEVEL INVERSION IN WARM AIR ADVECTION WILL LIMIT THE TRANSFER OF HIGHER MOMENTUM AND FORGO THE NEED FOR A WIND ADVISORY. FOR TONIGHT...SURFACE LOW PRESSURE CONTINUES TO DEEPEN ACROSS WESTERN NEBRASKA...AS THE OVERALL SYSTEM BECOMES NEARLY VERTICALLY STACKED LATE TONIGHT AS THE POTENT UPPER LEVEL WAVE PROPAGATES ONTO THE PLAINS. RESULTING MOISTURE TRANSPORT INCREASES ACROSS THE NORTHERN PLAINS...WITH RAIN SHOWER COVERAGE INCREASING AFTER 06 UTC ACROSS WESTERN NORTH DAKOTA IN THE VICINITY OF THE INVERTED TROUGH EXTENDING INTO EASTERN MONTANA...AND ACROSS SOUTHERN NORTH DAKOTA IN LOW LEVEL WARM AIR ADVECTION. THE BULK OF ELEVATED INSTABILITY TONIGHT REMAINS IN SOUTH DAKOTA...HOWEVER AN EMBEDDED THUNDERSTORM IS POSSIBLE ACROSS FAR SOUTH CENTRAL NORTH DAKOTA . .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 329 AM CDT SAT APR 26 2014 THE MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE THE STRONG SPRING STORM SYSTEM AFFECTING ALL OF WESTERN AND CENTRAL NORTH DAKOTA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE TRACK OF THE SURFACE AND UPPER LEVEL FEATURES THROUGH TUESDAY...WITH DIFFERENCES INCREASING THEREAFTER. STILL SOME DIFFERENCES IN QPF PATTERN THROUGH THE EVOLUTION OF THE SYSTEM WITH THE GFS BEING THE DRIEST ACROSS PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. ALL MODELS HOWEVER ARE PINPOINTING THE FAR SOUTHWEST WITH SOME OF THE HIGHEST RAINFALL AMOUNTS. STRONG SHORTWAVE JUST MOVING ONTO THE SOUTHERN CALIFORNIA COAST WITH AN UPPER LEVEL LOW CLOSING OFF JUST TO ITS NORTH. BROAD FETCH OF MOISTURE IN SOUTHWEST UPPER FLOW INTO THE NORTHERN PLAINS...SETTING THE STAGE FOR AN EXTENDED PERIOD OF RAINY WEATHER. BY SUNDAY MORNING THE UPPER LOW IS PROGGED TO BE OVER EASTERN COLORADO WITH A RAPIDLY DEEPENING SURFACE SYSTEM OVER THE CENTRAL PLAINS. THE INITIAL SURGE OF ENERGY MOVES INTO THE AREA LATE TONIGHT INTO SUNDAY MORNING. ALTHOUGH BEST ELEVATED INSTABILITY REMAINS JUST TO OUR SOUTH...SYSTEM IS STRONG ENOUGH THAT A MENTION OF THUNDER SEEMED WARRANTED SUNDAY MORNING. BEST PRECIPITATION CHANCES DURING THE DAY WILL BE OVER THE SOUTHWEST HALF OF THE CWA...AND THERE MAY BE PERIODS OF NO RAIN AS WELL AS DRIER AIR WRAPS AROUND THE STACKED SYSTEM. ANOTHER STRONG IMPULSE LIFTS THROUGH THE AREA SUNDAY NIGHT AS THE UPPER LOW REACHES ITS FARTHEST POINT NORTH BEFORE WOBBLING BACK SOUTH ON MONDAY. BY THIS TIME CHANCES OF CONVECTION WILL BE MINIMAL AS COOLER AIR GETS PULLED INTO THE SYSTEM. THE FAR NORTH AND HIGHER ELEVATIONS IN THE FAR WEST COULD SEE PERIODS OF SNOW LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING. LATEST MODEL RUNS ARE A LITTLE COOLER IN THE WEST SO WILL NEED TO MONITOR FOR SOME LIGHT ACCUMULATING SNOWS IN THE FAR WEST...BUT AT THIS TIME ITS TOO EARLY FOR ANY MENTION OF ACCUMULATIONS. PRECIPITATION BEGINS TO WANE ON MONDAY AS THE LOW DROPS SOUTH. ALTHOUGH LOW LEVEL FORCING WILL BE ON THE DECREASE...SYNOPTIC SCALE FORCING WILL REMAIN THROUGH TUESDAY AS WE REMAIN UNDER THE CYCLONIC FLOW OF THE UPPER LEVEL LOW. THUS LIKELY POPS REMAIN MONDAY INTO MONDAY NIGHT...WITH HIGH CHANCE POPS TUESDAY. AGAIN WE WILL SEE THE POSSIBILITY OF SNOW MONDAY NIGHT INTO TUESDAY MORNING...AND LIGHT ACCUMULATIONS ARE CERTAINLY NOT OUT OF THE QUESTION. THE UPPER LOW LIFTS BACK NORTHWARD TUESDAY NIGHT INTO WEDNESDAY WITH ANOTHER WAVE OF MOISTURE SWINGING EAST TO WEST ACROSS THE AREA ON WEDNESDAY BRINGING A CHANCE OF RAIN OR SNOW SHOWERS. THE SYSTEM FINALLY EXITS THE ARE LATE IN THE WORK WEEK...WITH ANOTHER IMPULSE IN A NORTHWEST FLOW PATTERN POSSIBLE BY NEXT WEEKEND. ALL IN ALL A WET AND COOL PERIOD IS IN STORE THROUGH MOST OF THE EXTENDED PERIOD. WILL ISSUE A HYDROLOGIC STATEMENT MENTIONING THE POSSIBILITY OF FLOODING DUE TO AN EXTENDED PERIOD OF RAIN. WPC DEPICTS PORTIONS OF THE SOUTHWEST WITH A SLIGHT CHANCE OF EXCESSIVE RAINFALL 12Z SUNDAY THROUGH 12Z MONDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 642 AM CDT SAT APR 26 2014 A NARROW BAND OF LIGHT RAIN SHOWERS HAS MOVED INTO WESTERN INTO SOUTH CENTRAL NORTH DAKOTA AS OF 1130 UTC...AND WILL CONTINUE TO MOVE NORTH-NORTHEAST THROUGH THE MORNING. RAIN SHOWER ACTIVITY IN THE AFTERNOON IS EXPECTED TO LARGELY REMAIN NORTH OF KISN AND KMOT. STRONG EAST-SOUTHEAST WINDS WITH GUSTS OF 30-35 KTS ARE EXPECTED FOR MUCH OF THE AREA TODAY. A LARGE STORM SYSTEM WILL BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA SATURDAY NIGHT...WITH CONDITIONS TRENDING TOWARDS MVFR/IFR IN STRATUS AND RAIN. && .HYDROLOGY... ISSUED AT 353 AM CDT SAT APR 26 2014 ISSUED A HYDROLOGIC OUTLOOK...ESF...FOR WESTERN NORTH DAKOTA REGARDING THE UPCOMING HEAVY RAIN EVENT AND POTENTIAL IMPACTS. AS OF NOW...THE 00 UTC DETERMINISTIC SUITE REMAINS IN SOME DISAGREEMENT ON THE PLACEMENT OF THE HEAVIEST QPF AXIS. THIS HAS SIGNIFICANT IMPACTS IN BASIN HYDROLOGIC RESPONSE. FURTHERMORE...THE REMOVAL OF FROST FROM THE GROUND AND RECENT DRY WEATHER PLACES ADDITIONAL UNCERTAINTY IN HOW MUCH WATER THE SOILS WILL BE ABLE TO HOLD. THAT SAID...RIVER AND STREAM RISES...POTENTIALLY ABOVE FLOOD STAGE...ARE POSSIBLE. HOWEVER...WHICH SPECIFIC WATERWAYS RESPOND THE MOST IS HIGHLY DEPENDENT ON QPF PLACEMENT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JV SHORT TERM...AYD LONG TERM...TWH AVIATION...AYD HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
642 AM CDT SAT APR 26 2014 .UPDATE... ISSUED AT 642 AM CDT SAT APR 26 2014 NARROW BAND OF SHOWERS FROM WEST CENTRAL INTO SOUTH CENTRAL NORTH DAKOTA CONTINUES TO LIFT NORTH THIS MORNING. ONLY SOME SLIGHT MODIFICATIONS TO THE CURRENT HRRR POP PLACEMENT TODAY. ALSO BUMPED UP SKY COVER THROUGH THE MORNING SOUTHWEST BASED ON LATEST SATELLITE IMAGERY. OTHERWISE CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 353 AM CDT SAT APR 26 2014 THE HIGHLIGHT OF THE SHORT TERM IS PRECIPITATION POTENTIAL. FOR TODAY...THE HRRR HAS HAD A GOOD HANDLE ON THE NARROW BAND OF RAIN SHOWERS MOVING INTO SOUTHWEST NORTH DAKOTA AS OF 0830 UTC WITH THE LEADING SHORTWAVE. THUS...WILL FOLLOW THE 07 UTC HRRR AND ITS PARENT RAP FOR POPS THIS MORNING AND INTO THE AFTERNOON. THESE SOLUTIONS ARE IN AGREEMENT WITH THE 00 UTC 4 KM WRF AND LARGER SCALE DETERMINISTIC GUIDANCE WHICH QUICKLY MOVE THE RAIN SHOWERS TO THE INTERNATIONAL BORDER BY EARLY AFTERNOON. THUS...AFTER THE NARROW BAND OF SHOWERS PASS...THE DAY SHOULD BE PRECIPITATION FREE FOR NEARLY ALL OF THE CWA. IN REGARDS TO WINDS FOR TODAY...EXPECT WIDESPREAD EAST-SOUTHEAST GUSTS OF 30-35 KTS FOR MOST AREAS. HOWEVER...A LOW LEVEL INVERSION IN WARM AIR ADVECTION WILL LIMIT THE TRANSFER OF HIGHER MOMENTUM AND FORGO THE NEED FOR A WIND ADVISORY. FOR TONIGHT...SURFACE LOW PRESSURE CONTINUES TO DEEPEN ACROSS WESTERN NEBRASKA...AS THE OVERALL SYSTEM BECOMES NEARLY VERTICALLY STACKED LATE TONIGHT AS THE POTENT UPPER LEVEL WAVE PROPAGATES ONTO THE PLAINS. RESULTING MOISTURE TRANSPORT INCREASES ACROSS THE NORTHERN PLAINS...WITH RAIN SHOWER COVERAGE INCREASING AFTER 06 UTC ACROSS WESTERN NORTH DAKOTA IN THE VICINITY OF THE INVERTED TROUGH EXTENDING INTO EASTERN MONTANA...AND ACROSS SOUTHERN NORTH DAKOTA IN LOW LEVEL WARM AIR ADVECTION. THE BULK OF ELEVATED INSTABILITY TONIGHT REMAINS IN SOUTH DAKOTA...HOWEVER AN EMBEDDED THUNDERSTORM IS POSSIBLE ACROSS FAR SOUTH CENTRAL NORTH DAKOTA . .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 329 AM CDT SAT APR 26 2014 THE MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE THE STRONG SPRING STORM SYSTEM AFFECTING ALL OF WESTERN AND CENTRAL NORTH DAKOTA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE TRACK OF THE SURFACE AND UPPER LEVEL FEATURES THROUGH TUESDAY...WITH DIFFERENCES INCREASING THEREAFTER. STILL SOME DIFFERENCES IN QPF PATTERN THROUGH THE EVOLUTION OF THE SYSTEM WITH THE GFS BEING THE DRIEST ACROSS PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. ALL MODELS HOWEVER ARE PINPOINTING THE FAR SOUTHWEST WITH SOME OF THE HIGHEST RAINFALL AMOUNTS. STRONG SHORTWAVE JUST MOVING ONTO THE SOUTHERN CALIFORNIA COAST WITH AN UPPER LEVEL LOW CLOSING OFF JUST TO ITS NORTH. BROAD FETCH OF MOISTURE IN SOUTHWEST UPPER FLOW INTO THE NORTHERN PLAINS...SETTING THE STAGE FOR AN EXTENDED PERIOD OF RAINY WEATHER. BY SUNDAY MORNING THE UPPER LOW IS PROGGED TO BE OVER EASTERN COLORADO WITH A RAPIDLY DEEPENING SURFACE SYSTEM OVER THE CENTRAL PLAINS. THE INITIAL SURGE OF ENERGY MOVES INTO THE AREA LATE TONIGHT INTO SUNDAY MORNING. ALTHOUGH BEST ELEVATED INSTABILITY REMAINS JUST TO OUR SOUTH...SYSTEM IS STRONG ENOUGH THAT A MENTION OF THUNDER SEEMED WARRANTED SUNDAY MORNING. BEST PRECIPITATION CHANCES DURING THE DAY WILL BE OVER THE SOUTHWEST HALF OF THE CWA...AND THERE MAY BE PERIODS OF NO RAIN AS WELL AS DRIER AIR WRAPS AROUND THE STACKED SYSTEM. ANOTHER STRONG IMPULSE LIFTS THROUGH THE AREA SUNDAY NIGHT AS THE UPPER LOW REACHES ITS FARTHEST POINT NORTH BEFORE WOBBLING BACK SOUTH ON MONDAY. BY THIS TIME CHANCES OF CONVECTION WILL BE MINIMAL AS COOLER AIR GETS PULLED INTO THE SYSTEM. THE FAR NORTH AND HIGHER ELEVATIONS IN THE FAR WEST COULD SEE PERIODS OF SNOW LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING. LATEST MODEL RUNS ARE A LITTLE COOLER IN THE WEST SO WILL NEED TO MONITOR FOR SOME LIGHT ACCUMULATING SNOWS IN THE FAR WEST...BUT AT THIS TIME ITS TOO EARLY FOR ANY MENTION OF ACCUMULATIONS. PRECIPITATION BEGINS TO WANE ON MONDAY AS THE LOW DROPS SOUTH. ALTHOUGH LOW LEVEL FORCING WILL BE ON THE DECREASE...SYNOPTIC SCALE FORCING WILL REMAIN THROUGH TUESDAY AS WE REMAIN UNDER THE CYCLONIC FLOW OF THE UPPER LEVEL LOW. THUS LIKELY POPS REMAIN MONDAY INTO MONDAY NIGHT...WITH HIGH CHANCE POPS TUESDAY. AGAIN WE WILL SEE THE POSSIBILITY OF SNOW MONDAY NIGHT INTO TUESDAY MORNING...AND LIGHT ACCUMULATIONS ARE CERTAINLY NOT OUT OF THE QUESTION. THE UPPER LOW LIFTS BACK NORTHWARD TUESDAY NIGHT INTO WEDNESDAY WITH ANOTHER WAVE OF MOISTURE SWINGING EAST TO WEST ACROSS THE AREA ON WEDNESDAY BRINGING A CHANCE OF RAIN OR SNOW SHOWERS. THE SYSTEM FINALLY EXITS THE ARE LATE IN THE WORK WEEK...WITH ANOTHER IMPULSE IN A NORTHWEST FLOW PATTERN POSSIBLE BY NEXT WEEKEND. ALL IN ALL A WET AND COOL PERIOD IS IN STORE THROUGH MOST OF THE EXTENDED PERIOD. WILL ISSUE A HYDROLOGIC STATEMENT MENTIONING THE POSSIBILITY OF FLOODING DUE TO AN EXTENDED PERIOD OF RAIN. WPC DEPICTS PORTIONS OF THE SOUTHWEST WITH A SLIGHT CHANCE OF EXCESSIVE RAINFALL 12Z SUNDAY THROUGH 12Z MONDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 642 AM CDT SAT APR 26 2014 A NARROW BAND OF LIGHT RAIN SHOWERS HAS MOVED INTO WESTERN INTO SOUTH CENTRAL NORTH DAKOTA AS OF 1130 UTC...AND WILL CONTINUE TO MOVE NORTH-NORTHEAST THROUGH THE MORNING. RAIN SHOWER ACTIVITY IN THE AFTERNOON IS EXPECTED TO LARGELY REMAIN NORTH OF KISN AND KMOT. STRONG EAST-SOUTHEAST WINDS WITH GUSTS OF 30-35 KTS ARE EXPECTED FOR MUCH OF THE AREA TODAY. A LARGE STORM SYSTEM WILL BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA SATURDAY NIGHT...WITH CONDITIONS TRENDING TOWARDS MVFR/IFR IN STRATUS AND RAIN. && .HYDROLOGY... ISSUED AT 353 AM CDT SAT APR 26 2014 ISSUED A HYDROLOGIC OUTLOOK...ESF...FOR WESTERN NORTH DAKOTA REGARDING THE UPCOMING HEAVY RAIN EVENT AND POTENTIAL IMPACTS. AS OF NOW...THE 00 UTC DETERMINISTIC SUITE REMAINS IN SOME DISAGREEMENT ON THE PLACEMENT OF THE HEAVIEST QPF AXIS. THIS HAS SIGNIFICANT IMPACTS IN BASIN HYDROLOGIC RESPONSE. FURTHERMORE...THE REMOVAL OF FROST FROM THE GROUND AND RECENT DRY WEATHER PLACES ADDITIONAL UNCERTAINTY IN HOW MUCH WATER THE SOILS WILL BE ABLE TO HOLD. THAT SAID...RIVER AND STREAM RISES...POTENTIALLY ABOVE FLOOD STAGE...ARE POSSIBLE. HOWEVER...WHICH SPECIFIC WATERWAYS RESPOND THE MOST IS HIGHLY DEPENDENT ON QPF PLACEMENT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...AYD LONG TERM...TWH AVIATION...AYD HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
356 AM CDT SAT APR 26 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 353 AM CDT SAT APR 26 2014 THE HIGHLIGHT OF THE SHORT TERM IS PRECIPITATION POTENTIAL. FOR TODAY...THE HRRR HAS HAD A GOOD HANDLE ON THE NARROW BAND OF RAIN SHOWERS MOVING INTO SOUTHWEST NORTH DAKOTA AS OF 0830 UTC WITH THE LEADING SHORTWAVE. THUS...WILL FOLLOW THE 07 UTC HRRR AND ITS PARENT RAP FOR POPS THIS MORNING AND INTO THE AFTERNOON. THESE SOLUTIONS ARE IN AGREEMENT WITH THE 00 UTC 4 KM WRF AND LARGER SCALE DETERMINISTIC GUIDANCE WHICH QUICKLY MOVE THE RAIN SHOWERS TO THE INTERNATIONAL BORDER BY EARLY AFTERNOON. THUS...AFTER THE NARROW BAND OF SHOWERS PASS...THE DAY SHOULD BE PRECIPITATION FREE FOR NEARLY ALL OF THE CWA. IN REGARDS TO WINDS FOR TODAY...EXPECT WIDESPREAD EAST-SOUTHEAST GUSTS OF 30-35 KTS FOR MOST AREAS. HOWEVER...A LOW LEVEL INVERSION IN WARM AIR ADVECTION WILL LIMIT THE TRANSFER OF HIGHER MOMENTUM AND FORGO THE NEED FOR A WIND ADVISORY. FOR TONIGHT...SURFACE LOW PRESSURE CONTINUES TO DEEPEN ACROSS WESTERN NEBRASKA...AS THE OVERALL SYSTEM BECOMES NEARLY VERTICALLY STACKED LATE TONIGHT AS THE POTENT UPPER LEVEL WAVE PROPAGATES ONTO THE PLAINS. RESULTING MOISTURE TRANSPORT INCREASES ACROSS THE NORTHERN PLAINS...WITH RAIN SHOWER COVERAGE INCREASING AFTER 06 UTC ACROSS WESTERN NORTH DAKOTA IN THE VICINITY OF THE INVERTED TROUGH EXTENDING INTO EASTERN MONTANA...AND ACROSS SOUTHERN NORTH DAKOTA IN LOW LEVEL WARM AIR ADVECTION. THE BULK OF ELEVATED INSTABILITY TONIGHT REMAINS IN SOUTH DAKOTA...HOWEVER AN EMBEDDED THUNDERSTORM IS POSSIBLE ACROSS FAR SOUTH CENTRAL NORTH DAKOTA . .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 329 AM CDT SAT APR 26 2014 THE MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE THE STRONG SPRING STORM SYSTEM AFFECTING ALL OF WESTERN AND CENTRAL NORTH DAKOTA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE TRACK OF THE SURFACE AND UPPER LEVEL FEATURES THROUGH TUESDAY...WITH DIFFERENCES INCREASING THEREAFTER. STILL SOME DIFFERENCES IN QPF PATTERN THROUGH THE EVOLUTION OF THE SYSTEM WITH THE GFS BEING THE DRIEST ACROSS PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. ALL MODELS HOWEVER ARE PINPOINTING THE FAR SOUTHWEST WITH SOME OF THE HIGHEST RAINFALL AMOUNTS. STRONG SHORTWAVE JUST MOVING ONTO THE SOUTHERN CALIFORNIA COAST WITH AN UPPER LEVEL LOW CLOSING OFF JUST TO ITS NORTH. BROAD FETCH OF MOISTURE IN SOUTHWEST UPPER FLOW INTO THE NORTHERN PLAINS...SETTING THE STAGE FOR AN EXTENDED PERIOD OF RAINY WEATHER. BY SUNDAY MORNING THE UPPER LOW IS PROGGED TO BE OVER EASTERN COLORADO WITH A RAPIDLY DEEPENING SURFACE SYSTEM OVER THE CENTRAL PLAINS. THE INITIAL SURGE OF ENERGY MOVES INTO THE AREA LATE TONIGHT INTO SUNDAY MORNING. ALTHOUGH BEST ELEVATED INSTABILITY REMAINS JUST TO OUR SOUTH...SYSTEM IS STRONG ENOUGH THAT A MENTION OF THUNDER SEEMED WARRANTED SUNDAY MORNING. BEST PRECIPITATION CHANCES DURING THE DAY WILL BE OVER THE SOUTHWEST HALF OF THE CWA...AND THERE MAY BE PERIODS OF NO RAIN AS WELL AS DRIER AIR WRAPS AROUND THE STACKED SYSTEM. ANOTHER STRONG IMPULSE LIFTS THROUGH THE AREA SUNDAY NIGHT AS THE UPPER LOW REACHES ITS FARTHEST POINT NORTH BEFORE WOBBLING BACK SOUTH ON MONDAY. BY THIS TIME CHANCES OF CONVECTION WILL BE MINIMAL AS COOLER AIR GETS PULLED INTO THE SYSTEM. THE FAR NORTH AND HIGHER ELEVATIONS IN THE FAR WEST COULD SEE PERIODS OF SNOW LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING. LATEST MODEL RUNS ARE A LITTLE COOLER IN THE WEST SO WILL NEED TO MONITOR FOR SOME LIGHT ACCUMULATING SNOWS IN THE FAR WEST...BUT AT THIS TIME ITS TOO EARLY FOR ANY MENTION OF ACCUMULATIONS. PRECIPITATION BEGINS TO WANE ON MONDAY AS THE LOW DROPS SOUTH. ALTHOUGH LOW LEVEL FORCING WILL BE ON THE DECREASE...SYNOPTIC SCALE FORCING WILL REMAIN THROUGH TUESDAY AS WE REMAIN UNDER THE CYCLONIC FLOW OF THE UPPER LEVEL LOW. THUS LIKELY POPS REMAIN MONDAY INTO MONDAY NIGHT...WITH HIGH CHANCE POPS TUESDAY. AGAIN WE WILL SEE THE POSSIBILITY OF SNOW MONDAY NIGHT INTO TUESDAY MORNING...AND LIGHT ACCUMULATIONS ARE CERTAINLY NOT OUT OF THE QUESTION. THE UPPER LOW LIFTS BACK NORTHWARD TUESDAY NIGHT INTO WEDNESDAY WITH ANOTHER WAVE OF MOISTURE SWINGING EAST TO WEST ACROSS THE AREA ON WEDNESDAY BRINGING A CHANCE OF RAIN OR SNOW SHOWERS. THE SYSTEM FINALLY EXITS THE ARE LATE IN THE WORK WEEK...WITH ANOTHER IMPULSE IN A NORTHWEST FLOW PATTERN POSSIBLE BY NEXT WEEKEND. ALL IN ALL A WET AND COOL PERIOD IS IN STORE THROUGH MOST OF THE EXTENDED PERIOD. WILL ISSUE A HYDROLOGIC STATEMENT MENTIONING THE POSSIBILITY OF FLOODING DUE TO AN EXTENDED PERIOD OF RAIN. WPC DEPICTS PORTIONS OF THE SOUTHWEST WITH A SLIGHT CHANCE OF EXCESSIVE RAINFALL 12Z SUNDAY THROUGH 12Z MONDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 353 AM CDT SAT APR 26 2014 LIGHT RAIN SHOWERS HAVE MOVED INTO SOUTHWEST NORTH DAKOTA AS OF 830 UTC...AND WILL CONTINUE TO MOVE NORTH-NORTHEAST THROUGH SATURDAY MORNING. RAIN SHOWER ACTIVITY IN THE AFTERNOON IS EXPECTED TO LARGELY REMAIN NORTH OF KISN AND KMOT. STRONG EAST- SOUTHEAST WINDS WITH GUSTS OF 30-35 KTS ARE EXPECTED FOR MUCH OF THE AREA TODAY. A LARGE STORM SYSTEM WILL BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA SATURDAY NIGHT...WITH CONDITIONS TRENDING TOWARDS MVFR/IFR IN STRATUS AND RAIN. && .HYDROLOGY... ISSUED AT 353 AM CDT SAT APR 26 2014 ISSUED A HYDROLOGIC OUTLOOK...ESF...FOR WESTERN NORTH DAKOTA REGARDING THE UPCOMING HEAVY RAIN EVENT AND POTENTIAL IMPACTS. AS OF NOW...THE 00 UTC DETERMINISTIC SUITE REMAINS IN SOME DISAGREEMENT ON THE PLACEMENT OF THE HEAVIEST QPF AXIS. THIS HAS SIGNIFICANT IMPACTS IN BASIN HYDROLOGIC RESPONSE. FURTHERMORE...THE REMOVAL OF FROST FROM THE GROUND AND RECENT DRY WEATHER PLACES ADDITIONAL UNCERTAINTY IN HOW MUCH WATER THE SOILS WILL BE ABLE TO HOLD. THAT SAID...RIVER AND STREAM RISES...POTENTIALLY ABOVE FLOOD STAGE...ARE POSSIBLE. HOWEVER...WHICH SPECIFIC WATERWAYS RESPOND THE MOST IS HIGHLY DEPENDENT ON QPF PLACEMENT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AYD LONG TERM...TWH AVIATION...AYD HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
108 AM CDT SAT APR 26 2014 .UPDATE... ISSUED AT 107 AM CDT SAT APR 26 2014 FOLLOWED THE TREND OF THE 02 THROUGH 04 UTC HRRR RUNS FOR POPS THE REMAINDER OF THE NIGHT...WHICH IS TO SCALE BACK THE OVERALL COVERAGE AND INTENSITY OF RAIN. THIS IS ALSO IN LINE WITH THE LARGER SCALE 00 UTC DETERMINISTIC MODELS. UPDATE ISSUED AT 920 PM CDT FRI APR 25 2014 LATE EVENING UPDATE FOR MINOR CHANGES TO POPS FOR THE OVERNIGHT HOURS. A SHORTWAVE TROUGH WILL LIFT NORTHEAST THROUGH THE REGION OVERNIGHT INTO SATURDAY MORNING...SUPPORTING AN AREA OF SHOWERS. MUCH OF THE RAIN SHOULD OCCUR PRIOR TO MIDDAY...WITH ONLY ISOLATED SHOWERS DURING THE AFTERNOON. WINDS MAY APPROACH ADVISORY CRITERIA SATURDAY...ESPECIALLY ACROSS THE SOUTHWEST. UPDATE ISSUED AT 623 PM CDT FRI APR 25 2014 NO SIGNIFICANT CHANGES FOR EARLY EVENING UPDATE. A BAND OF SHOWERS IS EXPECTED TO LIFT INTO SOUTHERN NORTH DAKOTA DURING THE EARLY MORNING HOURS...AND CONTINUE TO LIFT NORTH ACROSS THE REST OF THE FORECAST AREA SATURDAY MORNING. SHOWERS WILL DIMINISH ACROSS THE NORTH SATURDAY AFTERNOON...FOLLOWED BY MORE SUBSTANTIAL RAINFALL LATE SATURDAY NIGHT AND SUNDAY. && .SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY) ISSUED AT 235 PM CDT FRI APR 25 2014 FRIDAY AFTERNOON...A FRONTAL BOUNDARY EXTENDED FROM NORTHEAST MONTANA ACROSS WEST CENTRAL NORTH DAKOTA INTO THE SOUTHEAST. NORTH OF THIS FRONT COOL AIR AND CLOUDS COVERED THE NORTH CENTRAL KEEPING THIS REGION QUITE COOL FRIDAY. TONIGHT...THE LOCATION OF THIS FRONT WILL PLAY AN IMPORTANT ROLE IN THE LOCATION OF THE SHOWERS AND THUNDERSTORMS. FOR THE REST OF THIS AFTERNOON...WIND CONVERGENCE WAS RESPONSIBLE FOR INCREASING CUMULUS CLOUDS ACROSS THE FRONTAL ZONE IN NORTHWEST NORTH DAKOTA. SEEING SOME SCATTERED SHOWERS IN NORTHEAST MONTANA AND WILL ADD A LATE AFTERNOON/EVENING PERIOD FOR SHOWERS NORTHWEST. TONIGHT...THE ONSET OF SHOWERS ACROSS THE SOUTHWEST SHOULD BEGIN MID EVENING AS THE EVENING SHOWERS ACROSS THE NORTHWEST FADE AWAY AFTER PEAK HEATING. PLACED THE BOUNDARY FOR THUNDERSTORMS ACROSS THE FAR SOUTHWEST TONIGHT AND THE SOUTH CENTRAL SATURDAY FOLLOWING THE 1KM MIXED LAYER CAPE. SEE LITTLE IN THE WAY OF INSTABILITY TO SUPPORT THUNDERSTORMS NORTH IF INTERSTATE 94 ON SATURDAY. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 235 PM CDT FRI APR 25 2014 LATEST WATER VAPOR IMAGERY SHOWS A NICE DARKENING SIGNATURE/SUBSIDENCE JUST BEHIND A SHORTWAVE SEEN CIRCULATING NEAR 38N/128W. WITH A JET STREAK STILL UPSTREAM OF THIS SHORTWAVE TROUGH...EXPECT A CONTINUE DIGGING AND DEEPENING OF THE SYSTEM AS IT SLIDES INTO THE SOUTHWEST SATURDAY...THEN CLOSES OFF AS IT EJECTS INTO THE CENTRAL PLAINS/UPPER MIDWEST SUNDAY THROUGH WEDNESDAY. THE OVERALL TREND CONTINUES TO SHOW A WIDESPREAD RAIN EVENT SUNDAY INTO TUESDAY. TOTAL RAINFALL AMOUNTS THROUGH TUESDAY LOOK TO RANGE FROM 1 TO 1.25 INCHES FROM FROM THE TURTLE MOUNTAINS INTO THE JAMES RIVER VALLEY...INCREASING TOWARDS THE WEST WITH 2 TO 3 INCHES OF LIQUID FROM CROSBY TO WILLISTON AND SOUTH TO BOWMAN. THERE CONTINUES TO BE A WEAK THREAT OF ELEVATED CONVECTION IN THE FAR SOUTHWEST AND FAR SOUTH CENTRAL SUNDAY...BUT THIS LOOKS TOO MARGINAL FOR ANY MENTION OF THUNDERSTORMS AT THIS TIME. THERE WILL LIKELY BE A MIX OF RAIN AND SNOW AT NIGHT...ESPECIALLY SUNDAY NIGHT AND MONDAY NIGHT ACROSS THE NORTHWEST AND NORTH CENTRAL. HOWEVER ANY SNOWFALL ACCUMULATIONS WILL REMAIN NEGLIGIBLE. AS THE AFOREMENTIONED UPPER LOW AND ASSOCIATED SURFACE LOW APPROACH LATE SATURDAY NIGHT INTO SUNDAY...A STRONG EAST TO SOUTHEAST WIND WILL DEVELOP WITH WINDS OF 25 TO 40 MPH ACROSS CENTRAL NORTH DAKOTA. THE STRONGEST SUSTAINED WINDS ARE FORECAST IN SOUTH CENTRAL NORTH DAKOTA AND THIS MAY NECESSITATE A WINDY ADVISORY IN THE FUTURE. THE UPPER LOW WILL SLOWLY MEANDER INTO THE UPPER MIDWEST TUESDAY AND AND INTO THE GREAT LAKES WEDNESDAY/THURSDAY. HIGHS IN THE 40S WILL DOMINATE SUNDAY THROUGH TUESDAY WITH A GRADUAL MODERATING TREND WEDNESDAY THROUGH FRIDAY. PRECIPITATION WILL BEGIN TO WANE TUESDAY WITH DRIER WEATHER WEDNESDAY. BEYOND WEDNESDAY...THE UPPER AIR PATTERN IS IN QUESTION...WITH THE GFS TRYING TO TRANSITION FROM A NORTHERLY FLOW TO A BROAD/SOMEWHAT MOIST WESTERLY FLOW INTO THE UPCOMING WEEKEND. MEANWHILE THE ECMWF MAINTAINS A STRONGER NORTHWEST FLOW WITH SUCCESSIVE SURGES OF COOLER AIR AND SOME PRECIPITATION INTO NORTH DAKOTA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 107 AM CDT SAT APR 26 2014 LIGHT RAIN SHOWERS WILL MOVE INTO SOUTHWEST NORTH DAKOTA AFTER 08 UTC TONIGHT...AND MOVE NORTH-NORTHEAST THROUGH SATURDAY MORNING. RAIN SHOWER ACTIVITY IN THE AFTERNOON IS EXPECTED TO LARGELY REMAIN NORTH OF KISN AND KMOT. HOWEVER...A LARGE STORM SYSTEM WILL BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA SATURDAY NIGHT...WITH CONDITIONS TRENDING TOWARDS MVFR/IFR IN STRATUS AND RAIN. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...WAA LONG TERM...KS AVIATION...AYD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
413 PM EDT SAT APR 26 2014 .SYNOPSIS... A WEAK COLD FRONT HAS SAGGED INTO CENTRAL OHIO AND INDIANA AS A WEATHER SYSTEM SHIFTS THROUGH THE GREAT LAKES. THE FRONT WILL STALL NEAR THE OHIO RIVER TONIGHT AS AN UPPER LEVEL RIDGE OF HIGH PRESSURE BUILDS OVER THE FRONT AND BRINGS CONTINUED QUIET WEATHER THROUGH SUNDAY. A LARGE...POTENT LOW PRESSURE SYSTEM WILL MOVE SLOWLY OUT OF THE ROCKIES INTO THE HIGH PLAINS ON SUNDAY NIGHT AND MONDAY ALLOWING THE STALLED BOUNDARY ALONG THE OHIO RIVER TO RETURN NORTHWARD AS A WARM FRONT. WITH THIS PUSH OF SOUTHERLY AIR...WARMTH AND MOISTURE AND WILL SPREAD NORTHWARD AND BRING UNSETTLED WEATHER THROUGH THE FIRST HALF OF THE WORK WEEK...WITH EPISODES OF SHOWERS AND THUNDERSTORMS ON TAP FROM LATE SUNDAY NIGHT ALL THE WAY THROUGH WEDNESDAY. A COOLER AND STILL UNSETTLED PATTERN WILL TAKE HOLD FOR THE END OF THE WORK WEEK AND INTO NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AT 18Z...SURFACE ANALYSIS PLACES A RATHER WELL-DEFINED COLD FRONT FROM NEAR PITTSBURGH TO COLUMBUS TO INDIANAPOLIS. A WARM AND DEEPLY MIXED BOUNDARY LAYER EXISTS SOUTH OF THE FRONT ACROSS THE LOCAL AREA WITH SCT CUMULUS BASED AROUND 7KFT AND TEMPS THAT HAVE WARMED WELL INTO THE 70S...AND A DEWPOINT DROP INTO THE 40S. THE FRONT IS ONLY WEAKLY CONVERGENT...AND MOST NWP SOLUTIONS ARE IN GROSS ERROR WITH THE AMOUNT OF MOISTURE IN THE BOUNDARY LAYER. HRRR HAS CAUGHT ONTO THIS WITH TIME - AND HAS SLOWLY DROPPED THE COVERAGE OF ANY POTENTIAL SHOWERS DEVELOPING FROM THE HIGH-BASED CUMULUS ALONG THE FRONT. GIVEN VERY DRY SUB-CLOUD LAYERS...AND A REDUCTION IN INSTBY VIA THE MIXED BOUNDARY LAYER...WILL LIKELY NOT MENTION ANY SHRA THROUGH THE NEXT 3-4 HOURS AND HOLD WITH SPRINKLE MENTIONS IN THE SCIOTO VALLEY THROUGH SUNSET FROM SOME OF THE DEEPER CUMULUS. AS THE BOUNDARY LAYER DECOUPLES TONIGHT...TEMPS SHOULD DROP OFF GIVEN THE DRY BOUNDARY LAYER. MID LEVEL WARM ADVECTION COUPLED WITH A VERY WEAK WAVE CRESTING THE BUILDING MID LEVEL RIDGE WILL LIKELY CONTINUE TO ALLOW MID-CLOUD TO DEVELOP ACROSS THE AREA OVERNIGHT. THIS...COUPLED WITH SOME INCREASING CIRRUS...SHOULD ALLOW FOR PARTLY CLOUDY SKIES AND TEMPS IN THE UPPER 30S TO LOWER 50S FROM NORTH TO SOUTH, && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... CURRENT GOES WATER VAPOR LOOPS AND 26.18Z RAP ANALYSIS CLEARLY SHOW POTENT UPPER LOW DIGGING/TURNING EAST NOW THROUGH AZ. THIS HAS INDUCED STRONG DOWNSTREAM RIDGING FROM THE LOWER MS VALLEY NORTHWARD INTO THE DAKOTAS WHILE GREAT LAKES SYSTEM DRIVING THE COLD FRONT MENTIONED ABOVE SLIDES INTO NEW ENGLAND. THE PROGRESSION OF THE LATTER SYSTEM INTO NEW ENGLAND AND THE FORMER SYSTEM OUT INTO COLORADO WILL ALLOW LARGE SCALE/AMPLIFIED RIDGING INTO AND ACROSS THE OHIO VALLEY ON SUNDAY. THESE RISING HEIGHTS WILL ACT TO STALL THE COLD FRONT CURRENTLY SAGGING THROUGH OHIO...WITH THE FRONT SETTING UP SOMEWHERE NEAR/ALONG THE OHIO RIVER. THERE IS A WEALTH OF MID/UPPER LEVEL MOISTURE STREAMING NORTHEASTWARD THROUGH THE NATIONS MIDSECTION IN THE STRONGER SWLY FLOW ON THE WEST SIDE OF THE RIDGE...SO FEEL TOMORROW WILL HAVE MORE CLOUDS THAN TODAY...LIKELY SOME MID LEVEL AC AND CIRRUS AS WARM/MOIST ADVECTION BEGINS FIRST AT THOSE LEVELS THE RIDGE CROSSES THE AREA. UNDERNEATH...WEAK HIGH PRESSURE WILL BE NOSING SOUTHWARD INTO EASTERN OHIO ON SUNDAY PROVIDING A DRY/EASTERLY BREEZE WHICH WILL KEEP TEMPERATURES A LITTLE COOLER THAN SATURDAY ESP NORTH OF THE OHIO RIVER. THERE WILL STILL BE QUITE A TEMP GRADIENT FROM NRN KY /SOUTH OF THE FRONT/ WHERE TEMPS NEAR 80 WILL BE POSSIBLE AGAIN...AND NORTH OF THE FRONT THE FACTOR OF EAST WINDS...MORE CLOUDS...WILL KEEP TEMPS IN THE 60S. COULD BE A SNEAKY BUST DAY IN TERMS OF TEMPS NOT WARMING AS MUCH AS EXPECTED WITH THE EASTERLY FLOW QUITE STRONG THE FURTHER NORTH OF THE OHIO RIVER ONE GOES. FIRST WAVES OF STRONGER THETA-E ADVECTION ARRIVE /850-700MB/ SUNDAY NIGHT AND PRIMARILY IN LATTER HALF OF THIS PERIOD...AS INITIAL PUSH OF MOISTURE TRANSPORT OCCURS AS SURFACE LOW SWINGS OUT INTO NEBRASKA AND DEEPENS AS THE UPPER LOW REACHES MATURITY AND BECOMES CUT OFF. DESPITE MID/UPPER LEVEL RIDGING STILL LARGELY BEING INTACT OVER THE OHIO VALLEY...THERE IS ENOUGH THERMODYNAMIC FORCING WITH THE WARM/MOIST ADVECTION THAT EXPECT A SCT-BKN WAVE OF SHOWERS AND ISOLD STORMS TO EVOLVE LATER SUNDAY EVENING TO OUR WEST AND CROSS THE AREA LATE SUNDAY NIGHT INTO MONDAY MORNING. DON/T SEE MUCH SEVERE THREAT WITH THIS AT ALL...PER 26.12Z GFS/NAM BUFR SOUNDINGS...INSTBY IS MARGINAL /LESS THAN 1000 J/KG/ AND EFFECTIVE SHEAR FOR THE PARCELS ABOVE THE BOUNDARY LAYER IS RATHER WEAK. THESE SHOULD BE ELEVATED STORMS AND MAIN IMPACTS/THREATS WILL BE SMALL HAIL AND/OR LOCALLY HEAVY DOWNPOURS. HAVE CONTINUED THE MENTION OF 60-75% RAIN CHANCES FOR THIS ACTIVITY...AS THERE REMAINS SOME UNCERTAINTY AT LEAST WITH HOW STRONG THE PUSH OF DEEPER MOISTURE IS AND THE REMAINING ANTECEDENT DRY AIRMASS OVER THE FORECAST AREA. ON MONDAY...THIS INITIAL WAVE OF ADVECTION-INDUCED SHOWERS/STORMS SHOULD PUSH NORTHEAST QUICKLY THROUGH THE MORNING AND MAY VERY WELL HAVE A LULL WITH BREAKS OF SUN IN THE AFTERNOON. HARD TO TELL FOR CERTAIN...WITH LARGE UPPER SYSTEM WELL TO THE WEST...THE ABSENCE OF SYNOPTIC FORCING IS RATHER EASY TO SEE. BUT MOIST FLOW AND CONTINUED WARMING OF THE LOWER TROP SHOULD ALLOW INSTABILITY TO BUILD AND THIS DEVELOPING WARM SECTOR MAY VERY WELL BE FILLED WITH A NUMBER OF CLUSTERS OF SHOWERS AND ISOLATED STORMS. SO THE AFTERNOON HOURS ON MONDAY REMAIN UP FOR GRABS...THERE MAY BE LESS RAIN COVERAGE IN THIS TIME PERIOD THAN CURRENT FORECAST DEPICTS. FEELING MORE CONFIDENT THAT CONFLUENT LOW LEVEL FLOW ALONG/EAST OF MS RIVER INTO THE MID OHIO VALLEY WILL IGNITE WITH SHOWERS/STORMS ON MONDAY EVENING AND NIGHT WHICH SHOULD INVOLVE THE LOCAL AREA AS THE NEXT SHORTWAVE SWINGS THROUGH AND EJECTS NORTHEAST OUT OF THE BASE OF THE LARGE CNTL CONUS TROUGH. GIVEN THE DEEP MSLP WAY TO THE WEST...LOW LEVEL WIND FLOWS WILL HAVE SOME COMPONENT OF SOUTHEAST OR EAST-SOUTHEAST TRAJECTORY ON MONDAY AFTN/EVE...AND GIVEN FAST/SWLY MID/UPPER LEVEL FLOW...PRESENTS AN OPPORTUNITY FOR ORGANIZED SEVERE STORMS ESP IN THE SOUTH WHERE BOUNDARY LAYER INSTBY WILL HAVE THE MOST TIME TO BUILD IN WAKE OF MONDAY MORNING ACTIVITY. HOWEVER...POINT FCST BUFR SOUNDINGS SHOW LACK OF DECENT EML TO STEEPEN TROPOSPHERIC LAPSE RATES...AND CAPE IS THUS TALL/SKINNY AND OVERALL INSTBY STILL LOOKING MARGINAL. BUT SHEAR WILL BE GOOD ESP WITH ANY EASTERLY COMPONENT TO THE LOW LEVEL WIND FIELD...SO IF ANY PROLONGED PERIOD OF HEATING DEVELOPS MONDAY AFTERNOON THE SUBSEQUENT THREATS FOR SEVERE GO UP LATE MON AFTN/NIGHT. RIGHT NOW THERE IS ENOUGH UNCERTAINTY NOT TO GET CARRIED AWAY...AND ACTUALLY GIVEN THE THERMODYNAMICS/PWAT ANOMALIES THERE IS JUST AS MUCH CONCERN FOR A BAND OF HEAVY/EXCESSIVE RAINFALL DEPENDING ON WHERE THE CONFLUENCE SETS UP. SO WATCHING THIS PERIOD CLOSELY. DECIDED NOT TO GET CUTE IN THE FORECAST...AND JUST RUNNING A HIGHER CHANCE FOR SHOWERS/STORMS FROM MONDAY THROUGH MONDAY NIGHT GIVEN OVERALL ENSEMBLE PROBS...DEEP MOISTURE...AND ARRIVAL OF TWO WAVES OF FORCING MENTIONED ABOVE. && .LONG TERM /TUESDAY THROUGH SATURDAY/... LARGE SLOW MOVING UPPER LEVEL LOW OVER THE NATIONS MID SECTION TO PROGRESS INTO THE GREAT LAKES BY THE END OF THE WEEK. WITH THE UPPER LOW POSITIONED TO OUR WEST...SFC FRONT LOOKS TO PUSH THROUGH ON TUESDAY. SOME MODEL SOLN DIFFERENCES EXIST REGARDING TIMING...SO UNCERTAINTY EXISTS REGARDING INSTABILITY AND POTENTIAL FOR SEVERE WEATHER. AS THE LOW APPROACHES... WIND FIELDS INCREASE WITH MARGINAL INSTBY INDICATED ON LATEST RUNS. WILL BECOME MORE FAVORABLE FOR HEAVY RAIN...ESPECIALLY ACROSS THE SE IN THE MORNING. SEVERE WEATHER IS A POSSIBILITY WITH THE BEST THREAT ACROSS THE SOUTH BUT THE DEGREE OF THREAT WILL DEPEND ON THE TRACK AND TIMING OF THE APPROACHING LOW/SFC FRONTAL PASSAGE. WILL CONTINUE LKLY POPS DURG TUESDAY IN THE EAST EARLY AND THEN ENTERING THE WEST LATE. MODEL SOLNS WORKING SOME DRIER AIR INTO ILN/S FA WEDNESDAY AS THE UPPER LOW PIVOTS INTO THE GREAT LAKES. WILL LIMIT POPS TO CHANCE CATEGORY. A DECREASING CHANCE FOR SHOWERS WILL CONTINUE THURSDAY INTO FRIDAY WITH THE UPPER LOW POSITIONED TO OUR NORTH. EXPECT SHOWER ACTIVITY TO BECOME MORE DIURNALLY DRIVEN WITH THE BEST CHANCE ACROSS THE NORTH. MODEL DIFFERENCES INCREASE ON HOW FAST THE UPPER LOW OPENS UP NEXT WEEKEND. WILL CONTINUE LOW POP CHANCE FOR A SHOWER WITH THE BEST THREAT ACRS THE NORTH. TEMP WISE...READINGS TO START OUT A LTL ABOVE NORMAL ON THE WARM SIDE OF THE SYSTEM TUESDAY AND THEN COOL DOWN TO CLOSE TO 10 DEGREES BELOW NORMAL THURSDAY/FRIDAY AS A COOLER AIRMASS MOVES INTO THE REGION. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... A WEAK FRONT IS MOVING SOUTH THROUGH THE TAF SITES THIS AFTERNOON...WITH WINDS SHIFTING GENTLY TODAY FROM THE WSW TO THE WNW. TONIGHT...THESE WINDS WILL SHIFT MORE APPRECIABLY IN DIRECTION...TURNING COUNTERCLOCKWISE TO NORTH AND THEN ENE BY MORNING. WIND GUSTS THIS AFTERNOON WILL PEAK OUT IN THE 20-25 KNOT RANGE...BUT CONDITIONS OVERNIGHT (THOUGH NOT CALM) WILL BE A LITTLE LIGHTER.` CHANCES OF PRECIPITATION ARE VERY LOW TODAY...THOUGH A FEW PATCHES OF CLOUDS (HIGH-BASED CUMULUS OR MID CLOUDS) WILL STILL DRIFT THROUGH THE AREA. CLOUDS WILL THICKEN AND LOWER SOMEWHAT DURING THE NEXT 24 HOURS...BUT STILL REMAINING EASILY IN THE VFR RANGE. THERE WILL BE A VERY SMALL CHANCE OF LIGHT RAIN EARLY ON SUNDAY MORNING...PERHAPS A LITTLE MORE LIKELY FOR DAYTON OR AREAS NORTHWEST OF THERE...BUT THIS SET OF TAFS WILL ONLY INDICATE SOME ADDITIONAL LOWERING OF THE CLOUD DECK FROM 08Z-12Z. OUTLOOK...MVFR TO IFR CONDITIONS WILL BE POSSIBLE AT TIMES IN RAIN AND THUNDERSTORMS FROM SUNDAY NIGHT THROUGH TUESDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...BINAU NEAR TERM...BINAU SHORT TERM...BINAU LONG TERM...AR AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS NORMAN OK
1235 PM CDT SAT APR 26 2014 .DISCUSSION... AVIATION DISCUSSION FOR THE 18Z TAFS IS BELOW. && .AVIATION... MAINLY VFR CONDITIONS ARE EXPECTED. TSRA COVERAGE...INTENSITY...LOCATIONS...AND TIMING REMAIN VERY UNCERTAIN. THUS...REMOVED TEMPO/PREVAILING MENTION OF THEM. WILL AMEND IF CONFIDENCE OF TSRA AFFECTING ANY GIVEN SITE INCREASES. MVFR CONDITIONS WILL DEVELOP EAST OF KEND-KLAW-KSPS 06-12Z. BRIEF IFR CONDITIONS MAY OCCUR AS WELL...BUT WERE NOT MENTIONED DUE TO LOW CONFIDENCE OF OCCURRENCE. NON CONVECTIVE LOW LEVEL WIND SHEAR IS POSSIBLE 01-14Z...BUT DID NOT MENTION DUE TO LOW CONFIDENCE. STRONG SOUTHWEST WINDS WILL DEVELOP 14-16Z. GUSTS OVER 35 KT AND MVFR RESTRICTIONS IN BLDU ARE POSSIBLE. DID NOT MENTION BLDU DUE TO LOW CONFIDENCE. MBS && .PREV DISCUSSION... /ISSUED 1057 AM CDT SAT APR 26 2014/ UPDATE... AS NEW DATA CONTINUES TO FILTER IN THIS MORNING... IT APPEARS THAT STORM CHANCES ARE LESS LIKELY TODAY AND THIS EVENING. 12Z OUN SOUNDING SHOWS ENOUGH OF A CAPPING INVERSION TO BE AN ISSUE FOR STORM DEVELOPMENT... ESPECIALLY WITH THE RELATIVELY LATE RETURN OF LOW-LEVEL MOISTURE. THE HRRR AND RAP CONTINUE WITH SOME LATE AFTERNOON DEVELOPMENT IN THE KNOX CITY-HOBART-ENID CORRIDOR LATE THIS AFTERNOON... BUT THIS IS ALSO WITH FORECAST TEMPERATURES CLIMBING INTO THE UPPER 90S TO TRIPLE DIGITS. IF TEMPERATURES DO GET WARMER THAN OUR CURRENT FORECAST... THEN THERE WILL BE A CHANCE OF ISOLATED HIGH-BASED STORMS DEVELOPING ALONG THE WESTERN EDGE OF THE MOISTURE AXIS... BUT CURRENT THOUGHTS ARE TO LOWER STORM CHANCES TO ISOLATED/LESS THAN 20 PERCENT FOR THIS AFTERNOON AND LOWER POPS FOR THIS EVENING AS WELL. THE EXPECTED HIGH BASES OF THE STORMS WILL ALSO MAKE THE SEVERE WEATHER SCENARIO /IF STORMS FORM/ PRIMARILY A HAIL/WIND THREAT. WILL CONTINUE TO WATCH TRENDS IN THE WEATHER THROUGH THE AFTERNOON AND MAKE ADDITIONAL ADJUSTMENTS AS NECESSARY. .26. PREV DISCUSSION... /ISSUED 643 AM CDT SAT APR 26 2014/ AVIATION... 26/12Z TAFS...VFR CONDITIONS EXPECTED TO PREVAIL MAJORITY OF FORECAST PERIOD WITH DEVELOPMENT OF STRONG SOUTH-SOUTHWEST WINDS. TSRA CHANCES WILL INCREASE TOWARD AND AFTER 00Z FROM SOUTHWEST OKLAHOMA AND KSPS TOWARD CENTRAL OKLAHOMA TERMINALS TOWARD AND AFTER 06Z. PRIMARILY MVFR/IFR IN TSRA WITH MVFR CIGS OUTSIDE OF TSRA SOUTHERN OKLAHOMA LATE TONIGHT AHEAD OF DRYLINE. PREV DISCUSSION... /ISSUED 501 AM CDT SAT APR 26 2014/ DISCUSSION... LATEST ITERATION OF FINE-SCALE MODELS STILL POINT TO AT LEAST ISOLATED THUNDERSTORM DEVELOPMENT ACROSS SOUTHWEST OKLAHOMA TOWARD OR JUST AFTER 00Z. TAKING THESE INTO ACCOUNT...AND LOOKING AT 00Z GFS/ECM AND NOW 06Z WRF... PROBABLE INITIATION AREAS AND MODE EVOLUTION FAIRLY DIVERSE. WE DO NOT THINK THAT THE MODELS HAVE A GOOD HANDLE ON QUALITY/DEPTH OF MOISTURE RETURN BUT ECM HAS VERIFIED MUCH BETTER THAN THE OTHER MODELS LAST 12 TO 24 HOURS AND WILL BE FOLLOWED CLOSER FOR NOW. WITH NEW OBS-U/A THIS MORNING HOPEFULLY THERE WILL BE BETTER CONSENSUS WITH 12Z MODELS. WE STILL EXPECT THE GREATEST POTENTIAL FOR RELATIVELY HIGH-BASED SUPERCELLS SW OKLAHOMA AND WRN NORTH TEXAS TOWARD AND AFTER 6 PM WHERE COINCIDENCE OF HOTTER TEMPS AND DEEPER MOISTURE WILL RESIDE. ADDITIONAL AND MORE WIDESPREAD DEVELOPMENT OF STORMS POSSIBLE AHEAD OF DRYLINE/PAC-FRONT LATE EVENING AND OVERNIGHT AS SUBSTANTIAL FORCING FINALLY APPROACHES. WITH INTENSE FORCING AND BACKING DEEP LAYER SHEAR...WE STILL EXPECT THE EVOLUTION OF A (OR MULTIPLE) ELEVATED CLUSTERS/BOW SEGMENTS THROUGH THE OVERNIGHT HOURS. THERE COULD STILL BE STRONG/SEVERE STORMS EARLY SUNDAY MORNING/DAYBREAK ACROSS CENTRAL AND EASTERN PORTIONS OF OKLAHOMA. REDEVELOPMENT SUNDAY AFTERNOON/EVENING ARE EXPECTED TO BE PRIMARILY EAST OF OUR CWA. GOING TO BE WINDY TODAY...WITH CURRENT GRIDS MARGINALLY APPROACHING WIND ADVISORY. SUNDAY WILL BE WINDIER MOST LOCATIONS AND A WIND ADVISORY IS EXPECTED. ALSO...WE HAVE ISSUED A FIRE WEATHER WATCH FOR MAJORITY OF WESTERN OKLAHOMA AND ADJACENT PARTS OF NORTH TEXAS WITH DRY/WARM AND WINDY CONDITIONS BEHIND DRYLINE/PAC-FRONT. DID NOT BRING WATCH INTO OKC METRO WITH TRANSITION TO GREEN FUELS. WATCH WAS PRIMARILY FOCUSED ON AREAS THAT ARE JUST ENTERING TRANSITION PHASE OF FUELS AND DROUGHT STRICKEN LOCATIONS. COOL WEEK WITH OCCASIONAL WINDY DAYS WITH PERSISTENT NORTHWEST FLOW. LIGHT SHOWERS WILL BE POSSIBLE MAINLY WEST/NORTH PARTS OF OKLAHOMA DURING THE WEEK WITH PASSAGE OF THERMAL TROUGHS THAT WILL ROTATE AROUND LARGE U.S. UPPER CYCLONE. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 87 66 81 51 / 10 50 30 10 HOBART OK 89 60 81 50 / 10 40 10 0 WICHITA FALLS TX 88 65 84 52 / 10 40 10 0 GAGE OK 90 58 77 46 / 10 20 10 10 PONCA CITY OK 88 66 81 49 / 10 50 40 10 DURANT OK 85 67 83 56 / 0 30 60 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR OKZ004>007-009>012-014>018-021>024-033>038-044. TX...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR TXZ083>089. && $$ 26/17/17
AREA FORECAST DISCUSSION
NWS NORMAN OK
1057 AM CDT SAT APR 26 2014 .UPDATE... AS NEW DATA CONTINUES TO FILTER IN THIS MORNING... IT APPEARS THAT STORM CHANCES ARE LESS LIKELY TODAY AND THIS EVENING. 12Z OUN SOUNDING SHOWS ENOUGH OF A CAPPING INVERSION TO BE AN ISSUE FOR STORM DEVELOPMENT... ESPECIALLY WITH THE RELATIVELY LATE RETURN OF LOW-LEVEL MOISTURE. THE HRRR AND RAP CONTINUE WITH SOME LATE AFTERNOON DEVELOPMENT IN THE KNOX CITY-HOBART-ENID CORRIDOR LATE THIS AFTERNOON... BUT THIS IS ALSO WITH FORECAST TEMPERATURES CLIMBING INTO THE UPPER 90S TO TRIPLE DIGITS. IF TEMPERATURES DO GET WARMER THAN OUR CURRENT FORECAST... THEN THERE WILL BE A CHANCE OF ISOLATED HIGH-BASED STORMS DEVELOPING ALONG THE WESTERN EDGE OF THE MOISTURE AXIS... BUT CURRENT THOUGHTS ARE TO LOWER STORM CHANCES TO ISOLATED/LESS THAN 20 PERCENT FOR THIS AFTERNOON AND LOWER POPS FOR THIS EVENING AS WELL. THE EXPECTED HIGH BASES OF THE STORMS WILL ALSO MAKE THE SEVERE WEATHER SCENARIO /IF STORMS FORM/ PRIMARILY A HAIL/WIND THREAT. WILL CONTINUE TO WATCH TRENDS IN THE WEATHER THROUGH THE AFTERNOON AND MAKE ADDITIONAL ADJUSTMENTS AS NECESSARY. .26. && .PREV DISCUSSION... /ISSUED 643 AM CDT SAT APR 26 2014/ AVIATION... 26/12Z TAFS...VFR CONDITIONS EXPECTED TO PREVAIL MAJORITY OF FORECAST PERIOD WITH DEVELOPMENT OF STRONG SOUTH-SOUTHWEST WINDS. TSRA CHANCES WILL INCREASE TOWARD AND AFTER 00Z FROM SOUTHWEST OKLAHOMA AND KSPS TOWARD CENTRAL OKLAHOMA TERMINALS TOWARD AND AFTER 06Z. PRIMARILY MVFR/IFR IN TSRA WITH MVFR CIGS OUTSIDE OF TSRA SOUTHERN OKLAHOMA LATE TONIGHT AHEAD OF DRYLINE. PREV DISCUSSION... /ISSUED 501 AM CDT SAT APR 26 2014/ DISCUSSION... LATEST ITERATION OF FINE-SCALE MODELS STILL POINT TO AT LEAST ISOLATED THUNDERSTORM DEVELOPMENT ACROSS SOUTHWEST OKLAHOMA TOWARD OR JUST AFTER 00Z. TAKING THESE INTO ACCOUNT...AND LOOKING AT 00Z GFS/ECM AND NOW 06Z WRF... PROBABLE INITIATION AREAS AND MODE EVOLUTION FAIRLY DIVERSE. WE DO NOT THINK THAT THE MODELS HAVE A GOOD HANDLE ON QUALITY/DEPTH OF MOISTURE RETURN BUT ECM HAS VERIFIED MUCH BETTER THAN THE OTHER MODELS LAST 12 TO 24 HOURS AND WILL BE FOLLOWED CLOSER FOR NOW. WITH NEW OBS-U/A THIS MORNING HOPEFULLY THERE WILL BE BETTER CONSENSUS WITH 12Z MODELS. WE STILL EXPECT THE GREATEST POTENTIAL FOR RELATIVELY HIGH-BASED SUPERCELLS SW OKLAHOMA AND WRN NORTH TEXAS TOWARD AND AFTER 6 PM WHERE COINCIDENCE OF HOTTER TEMPS AND DEEPER MOISTURE WILL RESIDE. ADDITIONAL AND MORE WIDESPREAD DEVELOPMENT OF STORMS POSSIBLE AHEAD OF DRYLINE/PAC-FRONT LATE EVENING AND OVERNIGHT AS SUBSTANTIAL FORCING FINALLY APPROACHES. WITH INTENSE FORCING AND BACKING DEEP LAYER SHEAR...WE STILL EXPECT THE EVOLUTION OF A (OR MULTIPLE) ELEVATED CLUSTERS/BOW SEGMENTS THROUGH THE OVERNIGHT HOURS. THERE COULD STILL BE STRONG/SEVERE STORMS EARLY SUNDAY MORNING/DAYBREAK ACROSS CENTRAL AND EASTERN PORTIONS OF OKLAHOMA. REDEVELOPMENT SUNDAY AFTERNOON/EVENING ARE EXPECTED TO BE PRIMARILY EAST OF OUR CWA. GOING TO BE WINDY TODAY...WITH CURRENT GRIDS MARGINALLY APPROACHING WIND ADVISORY. SUNDAY WILL BE WINDIER MOST LOCATIONS AND A WIND ADVISORY IS EXPECTED. ALSO...WE HAVE ISSUED A FIRE WEATHER WATCH FOR MAJORITY OF WESTERN OKLAHOMA AND ADJACENT PARTS OF NORTH TEXAS WITH DRY/WARM AND WINDY CONDITIONS BEHIND DRYLINE/PAC-FRONT. DID NOT BRING WATCH INTO OKC METRO WITH TRANSITION TO GREEN FUELS. WATCH WAS PRIMARILY FOCUSED ON AREAS THAT ARE JUST ENTERING TRANSITION PHASE OF FUELS AND DROUGHT STRICKEN LOCATIONS. COOL WEEK WITH OCCASIONAL WINDY DAYS WITH PERSISTENT NORTHWEST FLOW. LIGHT SHOWERS WILL BE POSSIBLE MAINLY WEST/NORTH PARTS OF OKLAHOMA DURING THE WEEK WITH PASSAGE OF THERMAL TROUGHS THAT WILL ROTATE AROUND LARGE U.S. UPPER CYCLONE. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 87 66 81 51 / 10 60 30 10 HOBART OK 89 60 81 50 / 20 50 10 0 WICHITA FALLS TX 88 65 84 52 / 20 60 10 0 GAGE OK 90 58 77 46 / 10 30 10 10 PONCA CITY OK 88 66 81 49 / 10 60 40 10 DURANT OK 85 67 83 56 / 10 50 60 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR OKZ004>007-009>012-014>018-021>024-033>038-044. TX...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR TXZ083>089. && $$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
541 PM EDT SAT APR 26 2014 .SYNOPSIS... AN UPPER LEVEL LOW WILL DROP THROUGH NEW ENGLAND TONIGHT. MINOR RIDGING MOVES IN FROM THE WEST...AND SHOULD MAKE FOR DRY WEATHER SUNDAY AND MOST OF MONDAY. BUT ANOTHER UPPER LEVEL LOW WILL DEVELOP OVER THE CENTRAL U.S. DURING THE UPCOMING WEEK. THIS FEATURE WILL CREATE A PROLONGED PERIOD OF UNSETTLED WEATHER FOR PENNSYLVANIA. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... WEAK FORCING ROLLING THRU NY STATE AND N/ERN PA WILL MAKE FOR SOME SCT SHRA. CURRENT CROP OF SHOWERS SEEMS WIDESPREAD OVER THE NERN THIRD OF THE AREA...BUT HARDLY ANYTHING BUT SPRINKLES ARE MAKING IT DOWN TO THE SURFACE FROM SUCH LOFTY HEIGHTS. WINDS ARE PRETTY STRONG AND GUSTING INTO THE M30S. BUT NOT QUITE BAD ENOUGH TO WARRANT AN ADVY. DEWPOINTS JUST A LITTTLE HIGHER IN MD AND SOME SFC/LLVL CONVG WILL LEAD TO COUPLE OF SHOWERS OR PERHAPS A TSRA IN THE SE BY EVENING. BUT THE DRY AIR IS MAKING IT REALLY TOUGH. LATEST RUC BARELY MAKES A SPRINKLE ANYWHERE IN THE CWA. WILL THEREFORE TAKE THE POPS LOWER THAN MY EARLIER THINKING. SOME HIGHER GUSTS OUT OF THE SHRA ARE STILL POSS. ANY SHOWERS SHOULD BE TO THE EAST/SOUTH OF THE AREA AFTER THE TROUGH/WEAK FRONT PUSHES OUT LATE THIS AFTN/VERY EARLY THIS EVENING. SKIES WILL CLEAR OUT OVER MUCH OF THE AREA THIS EVENING. NERN AREAS WILL HAVE TO DEAL WITH SOME LOW CLOUDS FOR THE FIRST HALF OF THE NIGHT. BUT AS THE UPPER LOW MOVES A LITTLE TO THE EAST AFTER SUNRISE...IT SHOULD GET SUNNY THERE...TOO. TEMPS WILL DIP INTO THE M30S IN THE CENTRAL MTS TONIGHT. WINDS REMAIN UP ENOUGH - GENERALLY ABOVE 5KTS - THAT WIDESPREAD FROST IS NOT ANTICIPATED. WILL MENTION PATCHY FROST FOR NOW IN THE CENTRAL VALLEYS. SERN AREAS WILL REMAIN MILDER THAN FROST ADVY WORRIES AND THE NW ISN/T IN THE GROWING SEASON YET. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... WINDS SHOULD PICK UP A BIT FROM A MINOR LULL IN THE SUNRISE/EARLY MORNING - MAINLY IN THE EAST CLOSER TO THE LOW PRESSURE MOVING OFF THE COAST. OTHER THAN SOME EARLY CLOUDS IN THE NE...THE SKY SHOULD BE MAINLY CLEAR SINCE WE ARE DOWNSTREAM OF THE RIDGE OVER THE UPPER GREAT LAKES. TEMPS WILL RISE QUICKLY AND ATTAIN 60-65F IN THE SRN HALF OF THE AREA AND U50S ELSEWHERE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... RIDGE OVER EASTERN U.S. WILL BRING MAINLY QUIET WEATHER SUNDAY NIGHT INTO MONDAY. LOW LEVEL WINDS TURN SE-SW...WITH CORE OF SOMEWHAT STRONGER FLOW FOCUSED OVER OHIO VALLEY - BEGINNING SURGE OF INCREASINGLY MOIST AIR FURTHER NORTHWARD IN THE FORM OF A WARM FRONT. BROAD UPPER LOW WILL CONTINUE TO SPIN OVER UPPER MIDWEST WHILE GRADUALLY DRIFTING EASTWARD...AS PATTERN REMAINS BLOCKED INTO EARLY NEXT WEEK. WARM FRONT BECOMES MORE DEFINED TO OUR SOUTH...AND WILL BECOME THE FOCUS FOR WIDESPREAD SHOWERS BY TUE/WED/THU AS LOW CREEPS EASTWARD TO PROVIDE AREA OF SYNOPTIC LIFT. QPF TOTALS LOOK TO BE IN THE QUARTER OF AN INCH RANGE BOTH TUE AND WED...WITH POTENTIAL FOR HEAVIER PRECIP WED NIGHT INTO THU AS SURFACE WAVE RIDES ALONG FRONTAL BOUNDARY. A WIDESPREAD 1-2 INCH TOTAL STILL SEEMS PLAUSIBLE OVER A 24-36HR PERIOD WED AFT INTO THU AS PWAT VALUES PEAK /AND INSTABILITY BRINGS CHANCE FOR TSTMS/. GIVEN THE PROJECTED SYNOPTIC PATTERN WITH CLOUDS AND SE FLOW...EXPECT DAYTIME TEMPS TO BE COOLER THAN NORMAL WHILE OVERNIGHT TEMPS AVG A LITTLE ABOVE LATE APRIL/EARLY MAY CLIMO. RIDGE RE-ESTABLISHES ITSELF OVER THE WEST COAST HEADING INTO NEXT WEEKEND...WHICH WILL KEEP BROAD TROUGH IN VICINITY AND KEEP FEEDING COOLER AIR INTO PA LATE WEEK INTO THE WEEKEND...ALONG WITH KEEPING A MENTION OF LIGHTER SHOWERS IN THE FORECAST /ESP IN THE NW HALF/. && .AVIATION /22Z SATURDAY THROUGH THURSDAY/... ADJUSTED WINDS SOME. OTHER CONCERN IS SHOWERS NEAR THE MD BORDER...GIVEN STRONG WIND FIELDS. EXPECT THESE TWO PROBLEMS TO EASE OFF BY SUNSET. 21Z TAFS SENT. EARLIER DISCUSSION BELOW. WIND STRONG AND GUSTY OUT OF THE WEST. GUSTS ARE CURRENTLY OVER 35 KTS OVER THE WRN MTS. CLOUD BASES ARE VFR BUT BKN/OVC MOST LOCATIONS IN THE DIURNAL INSTABILITY. SOME MVFR CIGS ARE SNEAKING TOWARD KBFD AND THE COOLING BEHIND THE WEAK FRONT/DRY LINE PASSING THROUGH MAY HELP LOWER THE BASES/CIGS THERE TO ABOUT FL025. SHOWERS MOVING THROUGH THE NE ARE HARDLY REACHING THE GROUND. WILL CONTINUE TO JUST MENTION VCSH INTO THE LATE AFTN/EVEN IN THE SRN TERMINALS. THEN CLEARING SHOULD ENSUE AT ALL BUT KBFD AND PERHAPS KIPT. THE COLD AIR/CYCLONIC FLOW MAY KEEP A BKN CIG THERE INTO THE NIGHT BEFORE IT BREAKS UP. WINDS WILL DIMINISH SOMEWHAT TONIGHT. HAVE OPTED TO KEEP FOG OUT OF THE TAFS SINCE THE AIR IS SO DRY. IF IT COULD ACTUALLY RAIN...THAT MIGHT HAPPEN. BUT SO FAR THE FL050 PLUS BASES TO THE CLOUDS DO NOT LEND THEMSELVES TO MOD OR HEAVY RAIN. HIGH PRESSURE BUILDS IN SUNDAY AND MONDAY...WITH GENERALLY UNRESTRICTED CONDITIONS. OUTLOOK... .SUN...VFR. .MON...VFR. .MON NIGHT...LOWERING CIGS AS WARM FRONT PASSES WITH MVFR/IFR AND DEVELOPING SHRA. .TUE-WED...MVFR/IFR WITH PERIODS OF RAIN/THUNDER. .THUR...MAINLY VFR...SCT SHRA POSS W. && .FIRE WEATHER... ANOTHER 1 TO 2 HOURS OF STRONG WIND GUST...SOME OVER 40 MPH. DEWPOINTS ON THE LOW SIDE. THE COMBINATION OF WINDS AND LOW DEWPOINTS WILL CONTINUE TO DRY THINGS OUT THROUGH SUNSET. EARLIER DISCUSSION BELOW. THE WINDS ARE STRONG...BUT SHOULD SLACKEN BUT NOT DROP OFF TOTALLY TONIGHT. THE RH/S SHOULD RISE ABOVE 30PCT TONIGHT AND BARELY TOUCH THAT NUMBER SUNDAY AFTN THANKS TO SOMEWHAT COOLER DAY TIME TEMPS. THE WINDS WILL STAY UNDER RED FLAG CRIT FOR MOST OF THE AREA SUNDAY...ONLY IN THE EAST WHERE PRESSURE GRADIENT IS TIGHT ENOUGH WILL THE WINDS GUST ABOVE 15 KTS. SO...IT IS A MARGINAL SITUATION FOR WINDS AND MIN RH/S THERE. BUT NOT CONFIDENT ENOUGH TO POST A FIRE WX WATCH AT THIS POINT. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...RXR AVIATION...DANGELO/MARTIN FIRE WEATHER...DANGELO/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
352 PM EDT SAT APR 26 2014 .SYNOPSIS... AN UPPER LEVEL LOW WILL DROP THROUGH NEW ENGLAND TONIGHT. MINOR RIDGING MOVES IN FROM THE WEST...AND SHOULD MAKE FOR DRY WEATHER SUNDAY AND MOST OF MONDAY. BUT ANOTHER UPPER LEVEL LOW WILL DEVELOP OVER THE CENTRAL U.S. DURING THE UPCOMING WEEK. THIS FEATURE WILL CREATE A PROLONGED PERIOD OF UNSETTLED WEATHER FOR PENNSYLVANIA. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... WEAK FORCING ROLLING THRU NY STATE AND N/ERN PA WILL MAKE FOR SOME SCT SHRA. CURRENT CROP OF SHOWERS SEEMS WIDESPREAD OVER THE NERN THIRD OF THE AREA...BUT HARDLY ANYTHING BUT SPRINKLES ARE MAKING IT DOWN TO THE SURFACE FROM SUCH LOFTY HEIGHTS. WINDS ARE PRETTY STRONG AND GUSTING INTO THE M30S. BUT NOT QUITE BAD ENOUGH TO WARRANT AN ADVY. DEWPOINTS JUST A LITTTLE HIGHER IN MD AND SOME SFC/LLVL CONVG WILL LEAD TO COUPLE OF SHOWERS OR PERHAPS A TSRA IN THE SE BY EVENING. BUT THE DRY AIR IS MAKING IT REALLY TOUGH. LATEST RUC BARELY MAKES A SPRINKLE ANYWHERE IN THE CWA. WILL THEREFORE TAKE THE POPS LOWER THAN MY EARLIER THINKING. SOME HIGHER GUSTS OUT OF THE SHRA ARE STILL POSS. ANY SHOWERS SHOULD BE TO THE EAST/SOUTH OF THE AREA AFTER THE TROUGH/WEAK FRONT PUSHES OUT LATE THIS AFTN/VERY EARLY THIS EVENING. SKIES WILL CLEAR OUT OVER MUCH OF THE AREA THIS EVENING. NERN AREAS WILL HAVE TO DEAL WITH SOME LOW CLOUDS FOR THE FIRST HALF OF THE NIGHT. BUT AS THE UPPER LOW MOVES A LITTLE TO THE EAST AFTER SUNRISE...IT SHOULD GET SUNNY THERE...TOO. TEMPS WILL DIP INTO THE M30S IN THE CENTRAL MTS TONIGHT. WINDS REMAIN UP ENOUGH - GENERALLY ABOVE 5KTS - THAT WIDESPREAD FROST IS NOT ANTICIPATED. WILL MENTION PATCHY FROST FOR NOW IN THE CENTRAL VALLEYS. SERN AREAS WILL REMAIN MILDER THAN FROST ADVY WORRIES AND THE NW ISN/T IN THE GROWING SEASON YET. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... WINDS SHOULD PICK UP A BIT FROM A MINOR LULL IN THE SUNRISE/EARLY MORNING - MAINLY IN THE EAST CLOSER TO THE LOW PRESSURE MOVING OFF THE COAST. OTHER THAN SOME EARLY CLOUDS IN THE NE...THE SKY SHOULD BE MAINLY CLEAR SINCE WE ARE DOWNSTREAM OF THE RIDGE OVER THE UPPER GREAT LAKES. TEMPS WILL RISE QUICKLY AND ATTAIN 60-65F IN THE SRN HALF OF THE AREA AND U50S ELSEWHERE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... RIDGE OVER EASTERN U.S. WILL BRING MAINLY QUIET WEATHER SUNDAY NIGHT INTO MONDAY. LOW LEVEL WINDS TURN SE-SW...WITH CORE OF SOMEWHAT STRONGER FLOW FOCUSED OVER OHIO VALLEY - BEGINNING SURGE OF INCREASINGLY MOIST AIR FURTHER NORTHWARD IN THE FORM OF A WARM FRONT. BROAD UPPER LOW WILL CONTINUE TO SPIN OVER UPPER MIDWEST WHILE GRADUALLY DRIFTING EASTWARD...AS PATTERN REMAINS BLOCKED INTO EARLY NEXT WEEK. WARM FRONT BECOMES MORE DEFINED TO OUR SOUTH...AND WILL BECOME THE FOCUS FOR WIDESPREAD SHOWERS BY TUE/WED/THU AS LOW CREEPS EASTWARD TO PROVIDE AREA OF SYNOPTIC LIFT. QPF TOTALS LOOK TO BE IN THE QUARTER OF AN INCH RANGE BOTH TUE AND WED...WITH POTENTIAL FOR HEAVIER PRECIP WED NIGHT INTO THU AS SURFACE WAVE RIDES ALONG FRONTAL BOUNDARY. A WIDESPREAD 1-2 INCH TOTAL STILL SEEMS PLAUSIBLE OVER A 24-36HR PERIOD WED AFT INTO THU AS PWAT VALUES PEAK /AND INSTABILITY BRINGS CHANCE FOR TSTMS/. GIVEN THE PROJECTED SYNOPTIC PATTERN WITH CLOUDS AND SE FLOW...EXPECT DAYTIME TEMPS TO BE COOLER THAN NORMAL WHILE OVERNIGHT TEMPS AVG A LITTLE ABOVE LATE APRIL/EARLY MAY CLIMO. RIDGE RE-ESTABLISHES ITSELF OVER THE WEST COAST HEADING INTO NEXT WEEKEND...WHICH WILL KEEP BROAD TROUGH IN VICINITY AND KEEP FEEDING COOLER AIR INTO PA LATE WEEK INTO THE WEEKEND...ALONG WITH KEEPING A MENTION OF LIGHTER SHOWERS IN THE FORECAST /ESP IN THE NW HALF/. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... WIND STRONG AND GUSTY OUT OF THE WEST. GUSTS ARE CURRENTLY OVER 35 KTS OVER THE WRN MTS. CLOUD BASES ARE VFR BUT BKN/OVC MOST LOCATIONS IN THE DIURNAL INSTABILITY. SOME MVFR CIGS ARE SNEAKING TOWARD KBFD AND THE COOLING BEHIND THE WEAK FRONT/DRY LINE PASSING THROUGH MAY HELP LOWER THE BASES/CIGS THERE TO ABOUT FL025. SHOWERS MOVING THROUGH THE NE ARE HARDLY REACHING THE GROUND. WILL CONTINUE TO JUST MENTION VCSH INTO THE LATE AFTN/EVEN IN THE SRN TERMINALS. THEN CLEARING SHOULD ENSUE AT ALL BUT KBFD AND PERHAPS KIPT. THE COLD AIR/CYCLONIC FLOW MAY KEEP A BKN CIG THERE INTO THE NIGHT BEFORE IT BREAKS UP. WINDS WILL DIMINISH SOMEWHAT TONIGHT. HAVE OPTED TO KEEP FOG OUT OF THE TAFS SINCE THE AIR IS SO DRY. IF IT COULD ACTUALLY RAIN...THAT MIGHT HAPPEN. BUT SO FAR THE FL050 PLUS BASES TO THE CLOUDS DO NOT LEND THEMSELVES TO MOD OR HEAVY RAIN. HIGH PRESSURE BUILDS IN SUNDAY AND MONDAY...WITH GENERALLY UNRESTRICTED CONDITIONS. OUTLOOK... .SUN...VFR. .MON...VFR. .MON NIGHT...LOWERING CIGS AS WARM FRONT PASSES WITH MVFR/IFR AND DEVELOPING SHRA. .TUE-WED...MVFR/IFR WITH PERIODS OF RAIN/THUNDER. .THUR...MAINLY VFR...SCT SHRA POSS W. && .FIRE WEATHER... SHOWERS TODAY ARE NOT HELPING RAISE ANY MOISTURE LEVELS. THE WINDS ARE STRONG...BUT SHOULD SLACKEN BUT NOT DROP OFF TOTALLY TONIGHT. THE RH/S SHOULD RISE ABOVE 30PCT TONIGHT AND BARELY TOUCH THAT NUMBER SUNDAY AFTN THANKS TO SOMEWHAT COOLER DAY TIME TEMPS. THE WINDS WILL STAY UNDER RED FLAG CRIT FOR MOST OF THE AREA SUNDAY...ONLY IN THE EAST WHERE PRESSURE GRADIENT IS TIGHT ENOUGH WILL THE WINDS GUST ABOVE 15 KTS. SO...IT IS A MARGINAL SITUATION FOR WINDS AND MIN RH/S THERE. BUT NOT CONFIDENT ENOUGH TO POST A FIRE WX WATCH AT THIS POINT. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...RXR AVIATION...DANGELO FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
238 PM EDT SAT APR 26 2014 .SYNOPSIS... AN UPPER LEVEL LOW WILL DROP THROUGH NEW ENGLAND TONIGHT. MINOR RIDGING MOVES IN FROM THE WEST...AND SHOULD MAKE FOR DRY WEATHER SUNDAY AND MOST OF MONDAY. BUT ANOTHER UPPER LEVEL LOW WILL DEVELOP OVER THE CENTRAL U.S. DURING THE UPCOMING WEEK. THIS FEATURE WILL CREATE A PROLONGED PERIOD OF UNSETTLED WEATHER FOR PENNSYLVANIA. && .NEAR TERM /THROUGH TONIGHT/... WEAK FORCING ROLLING THRU NY STATE AND N/ERN PA WILL MAKE FOR SOME SCT SHRA. CURRENT CROP OF SHOWERS SEEMS WIDESPREAD OVER THE NERN THIRD OF THE AREA...BUT HARDLY ANYTHING BUT SPRINKLES ARE MAKING IT DOWN TO THE SURFACE FROM SUCH LOFTY HEIGHTS. WINDS ARE PRETTY STRONG AND GUSTING INTO THE M30S. BUT NOT QUITE BAD ENOUGH TO WARRANT AN ADVY. DEWPOINTS JUST A LITTTLE HIGHER IN MD AND SOME SFC/LLVL CONVG WILL LEAD TO COUPLE OF SHOWERS OR PERHAPS A TSRA IN THE SE BY EVENING. BUT THE DRY AIR IS MAKING IT REALLY TOUGH. LATEST RUC BARELY MAKES A SPRINKLE ANYWHERE IN THE CWA. WILL THEREFORE TAKE THE POPS LOWER THAN MY EARLIER THINKING. SOME HIGHER GUSTS OUT OF THE SHRA ARE STILL POSS. ANY SHOWERS SHOULD BE TO THE EAST/SOUTH OF THE AREA AFTER THE TROUGH/WEAK FRONT PUSHES OUT LATE THIS AFTN/VERY EARLY THIS EVENING. SKIES WILL CLEAR OUT OVER MUCH OF THE AREA THIS EVENING. NERN AREAS WILL HAVE TO DEAL WITH SOME LOW CLOUDS FOR THE FIRST HALF OF THE NIGHT. BUT AS THE UPPER LOW MOVES A LITTLE TO THE EAST AFTER SUNRISE...IT SHOULD GET SUNNY THERE...TOO. TEMPS WILL DIP INTO THE M30S IN THE CENTRAL MTS TONIGHT. WINDS REMAIN UP ENOUGH - GENERALLY ABOVE 5KTS - THAT WIDESPREAD FROST IS NOT ANTICIPATED. WILL MENTION PATCHY FROST FOR NOW IN THE CENTRAL VALLEYS. SERN AREAS WILL REMAIN MILDER THAN FROST ADVY WORRIES AND THE NW ISN/T IN THE GROWING SEASON YET. && .SHORT TERM /SUNDAY/... WINDS SHOULD PICK UP A BIT FROM A MINOR LULL IN THE SUNRISE/EARLY MORNING - MAINLY IN THE EAST CLOSER TO THE LOW PRESSURE MOVING OFF THE COAST. OTHER THAN SOME EARLY CLOUDS IN THE NE...THE SKY SHOULD BE MAINLY CLEAR SINCE WE ARE DOWNSTREAM OF THE RIDGE OVER THE UPPER GREAT LAKES. TEMPS WILL RISE QUICKLY AND ATTAIN 60-65F IN THE SRN HALF OF THE AREA AND U50S ELSEWHERE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... THE 26/00Z MEDIUM RANGE MODEL AND ENSEMBLE GUIDANCE CONTINUES TO ADVERTISE A LARGE SCALE PATTERN SHIFT TO A BLOCKING REGIME ACROSS THE CONUS FOR DAYS 4-7/MON-FRI...WITH REX BLOCK OVER CENTRAL NOAM AND UPPER RIDGES ALONG THE WEST/EAST COASTS. AFTER AN INITIALLY DRY PERIOD ON SUNDAY INTO EARLY MONDAY ASSOCIATED WITH A NARROW SFC HIGH PINCHED IN-BETWEEN SFC LOWS MIGRATING OVER THE PLAINS/NRN ATLC...THE EVOLVING PATTERN FAVORS INCREASINGLY WET AND RELATIVELY COOL CONDITIONS OVER CENTRAL PA. THEREFORE HAVE ADJUSTED POPS UPWARD IN THE LONG TERM...WITH INCREASING CONFIDENCE IN SIGNIFICANT/BENEFICIAL RAINFALL FOCUSED IN THE TUE-THR TIMEFRAME. A WIDESPREAD 1-2 INCHES SEEMS PLAUSIBLE AT THIS TIME OVER A 48-72HR PERIOD CENTERED AROUND THE MIDDLE OF NEXT WEEK. GIVEN THE PROJECTED SYNOPTIC PATTERN WITH CLOUDS AND SE FLOW...EXPECT DAYTIME TEMPS TO BE COOLER THAN NORMAL WHILE OVERNIGHT TEMPS AVG A LITTLE ABOVE LATE APRIL/EARLY MAY CLIMO. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... WIND STRONG AND GUSTY OUT OF THE WEST. GUSTS ARE CURRENTLY OVER 35 KTS OVER THE WRN MTS. CLOUD BASES ARE VFR BUT BKN/OVC MOST LOCATIONS IN THE DIURNAL INSTABILITY. SOME MVFR CIGS ARE SNEAKING TOWARD KBFD AND THE COOLING BEHIND THE WEAK FRONT/DRY LINE PASSING THROUGH MAY HELP LOWER THE BASES/CIGS THERE TO ABOUT FL025. SHOWERS MOVING THROUGH THE NE ARE HARDLY REACHING THE GROUND. WILL CONTINUE TO JUST MENTION VCSH INTO THE LATE AFTN/EVEN IN THE SRN TERMINALS. THEN CLEARING SHOULD ENSUE AT ALL BUT KBFD AND PERHAPS KIPT. THE COLD AIR/CYCLONIC FLOW MAY KEEP A BKN CIG THERE INTO THE NIGHT BEFORE IT BREAKS UP. WINDS WILL DIMINISH SOMEWHAT TONIGHT. HAVE OPTED TO KEEP FOG OUT OF THE TAFS SINCE THE AIR IS SO DRY. IF IT COULD ACTUALLY RAIN...THAT MIGHT HAPPEN. BUT SO FAR THE FL050 PLUS BASES TO THE CLOUDS DO NOT LEND THEMSELVES TO MOD OR HEAVY RAIN. HIGH PRESSURE BUILDS IN SUNDAY AND MONDAY...WITH GENERALLY UNRESTRICTED CONDITIONS. OUTLOOK... .SUN...VFR. .MON...VFR. .MON NIGHT...LOWERING CIGS AS WARM FRONT PASSES WITH MVFR/IFR AND DEVELOPING SHRA. .TUE-WED...MVFR/IFR WITH PERIODS OF RAIN/THUNDER. .THUR...MAINLY VFR...SCT SHRA POSS W. && .FIRE WEATHER... SHOWERS TODAY ARE NOT HELPING RAISE ANY MOISTURE LEVELS. THE WINDS ARE STRONG...BUT SHOULD SLACKEN BUT NOT DROP OFF TOTALLY TONIGHT. THE RH/S SHOULD RISE ABOVE 30PCT TONIGHT AND BARELY TOUCH THAT NUMBER SUNDAY AFTN THANKS TO SOMEWHAT COOLER DAY TIME TEMPS. THE WINDS WILL STAY UNDER RED FLAG CRIT FOR MOST OF THE AREA SUNDAY...ONLY IN THE EAST WHERE PRESSURE GRADIENT IS TIGHT ENOUGH WILL THE WINDS GUST ABOVE 15 KTS. SO...IT IS A MARGINAL SITUATION FOR WINDS AND MIN RH/S THERE. BUT NOT CONFIDENT ENOUGH TO POST A FIRE WX WATCH AT THIS POINT. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...STEINBUGL AVIATION...DANGELO FIRE WEATHER...DANGELO
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1016 PM EDT SUN APR 27 2014 .SYNOPSIS... A WET AND STORMY PATTERN WILL SET UP ACROSS THE AREA MONDAY THROUGH WEDNESDAY...FOLLOWED BY COOL AND DRIER HIGH PRESSURE BY THE END OF THE WEEK. && .NEAR TERM /THROUGH MONDAY/... AS OF 1010 PM EDT SUNDAY...BLENDED POPS ARE WORKING WELL AS SCATTERED LIGHT SHOWERS HAVE DEVELOPED OVER THE WESTERN ZONES...AND A FEW STRONGER STORMS HAVE DEVELOPED NOT TOO FAR UPSTREAM OF THE FORECAST AREA. POPS AND SKY COVER LOOK GOOD. AT 735 PM EDT SUNDAY...BLENDED A POP DERIVED FROM LOCAL CONVECTIVE ALLOWING MODELS AND THE OFFICIAL FORECAST TO GO WITH A SMALL AREA OF HIGH CHANCE AND LIKELY POPS FROM THE UPSTATE INTO THE SRN AND CENTRAL NC MTNS. THE 18 UTC NAM HAD A LITTLE BETTER ELEVATED CAPE ACROSS THIS AREA AND THE HRRR AND WRF-ARW ARE INCREASES CONVECTIVE COVERAGE OVER THIS AREA LATER TONIGHT. OTHERWISE...INCREASED SKY COVER AND MADE SOME MINOR TWEAKS TO THE REST OF THE GRIDS. AT 430 PM EDT SUNDAY...ADJUSTED SKY GRIDS TO ACCOUNT FOR ENCROACHING HIGH CLOUDS AS WELL AS A CU DECK THAT IS DEVELOPING ACROSS NE GA...THE SW NC MTNS AND THE WRN UPSTATE. SOME OF THE MESOSCALE MODELS BRING ELEVATED CONVECTION ACROSS THE FORECAST AREA OVERNIGHT AS THE LEADING EDGE OF THE ELEVATED MIXED LAYER WORKS IN FROM THE WEST. I DON/T SEE MUCH MUCAPE ON THE 18 UTC NAM...SO THINK MOST OF THE ACTIVITY WILL BE WEAK. I WON/T ADJUST THE OVERNIGHT GRIDS JUST YET..BUT I NEED TO RAMP UP POPS WITH SUBSEQUENT UPDATES. AT 200 PM EDT SUNDAY...A NEGATIVELY TILTED UPPER TROUGH WILL SLOWLY PROGRESS ACROSS THE SOUTHERN APPALACHIANS AND GREAT LAKES TONIGHT... WHILE A CLOSED UPPER LOW MOVES NE ACROSS THE GREAT PLAINS. THE RIDGE AXIS MOVES EAST OF THE MOUNTAINS ON MONDAY...WHILE THE UPPER LOW DRIFTS BACK SOUTH OVER THE PLAINS. ISENTROPIC UPGLIDE WILL SPREAD ACROSS THE UPPER SAVANNAH RIVER VALLEY AND SOUTHERN APPALACHIANS LATE THIS AFTERNOON AND THIS EVENING. INSTABILITY SHOULD BECOME SUFFICIENT FOR CONVECTION TO FORM BEFORE EVENING...HOWEVER NEITHER SHEAR NOR INSTABILITY APPEAR IMPRESSIVE. A BACK DOOR COLD FRONT WILL SETTLE SOUTH ACROSS WESTERN NC TONIGHT...REACHING THE SC BORDER EAST OF THE MOUNTAINS BY DAYBREAK. THE BOUNDARY WILL BECOME A FOCUS FOR CONVECTIVE ACTIVITY ON MONDAY...WHEN BETTER SHEAR AND INSTABILITY WILL BE PRESENT. SPC HAS OUR ENTIRE AREA IN A SLIGHT RISK FOR SEVERE WEATHER ON DAY TWO...MENTIONING AN ENVIRONMENT FAVORABLE FOR SUPERCELLS. THE AREA NORTH OF INTERSTATE 40 MAY REMAIN UNFAVORABLE FOR CONVECTION DURING THE DAYLIGHT HOURS ON MONDAY...AS COOL NE FLOW PREVAILS BEHIND THE FRONT...AND A CAP REMAINS AT AROUND 875 MB. WITH THE BEST GULF INFLOW STILL WELL TO THE WEST...EXCESSIVE RAINFALL IS NOT EXPECTED...HOWEVER INDIVIDUAL STORMS MAY PUT DOWN LOCALLY HEAVY RAINFALL. MINIMUM TEMPERATURES WILL BE WELL ABOVE NORMAL UNDER INCREASING CLOUDS COVER AND THE UPPER RIDGE. HIGH TEMPERATURES ON MONDAY WILL RUN SLIGHTLY ABOVE NORMAL...AS CLOUD COVERAGE OFFSETS THE INFLUENCE OF THE UPPER RIDGE. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... AS OF 235 PM SUNDAY...NOTHING IN THE NEW GUIDANCE TO CHANGE EARLIER THINKING THAT WE ARE ON A COLLISION COURSE WITH A VERY WET AND VERY STORMY PATTERN DURING THE LATE MONDAY TO WEDNESDAY TIME FRAME. IMPORTANT DETAILS SUCH AS THE TIMING OF ENHANCED SEVERE THUNDERSTORM THREATS...AND STORM TOTAL RAINFALL...STILL REMAIN IN DOUBT. ONE INTERESTING TREND OR POINT OF CONCERN IS BROUGHT TO LIGHT IN THE LATEST NAM MONDAY NIGHT AND EARLY TUESDAY MORNING. A WEDGE BOUNDARY OF SORTS IS INDICATED EVEN FARTHER SOUTH THAN PREVIOUS RUNS...DOWN CLOSER TO THE SC/NC BORDER. THE AIR MASS TO THE SOUTH OF THE BOUNDARY MIGHT BE FAIRLY RICH WITH BUOYANCY. THE SREF HAS A VERY HIGH PROBABILITY OF CAPE GREATER THAN 1000 J/KG LATE IN THE DAY...AND EVEN THE GENERALLY MORE CONSERVATIVE GFS HAS CAPE IN THE 1000 - 1500 J/KG RANGE. SHEAR AND SRH WILL INCREASE STEADILY THROUGH THE EVENING HOURS IN THE PRESENCE OF ADEQUATE BUOYANCY...THUS OUR CHANCES FOR ORGANIZED SEVERE THUNDERSTORMS WILL ALSO INCREASE. AGREE WITH THE EXPANSION OF THE DAY2 SLIGHT RISK FURTHER EAST IN THE NEW OUTLOOK. IF THE WEST TO EAST ORIENTED BOUNDARY REMAINS IN THE AREA...THIS COULD PROVIDE THE FOCUS FOR SEVERE STORMS AND TORNADIC ACTIVITY SOMEWHERE IN THE CAROLINAS WELL INTO THE OVERNIGHT HOURS. THERE IS ALSO THE CONCERN THAT SUPERCELLULAR CONVECTION MOVING IN FROM GEORGIA DURING THE EVENING WILL GET A SHOT OF INCREASED SHEAR AS IT INTERACTS WITH A BOUNDARY. AT THE SAME TIME...THE FRONTAL ZONE OF HEAVIER RAIN WILL MOVE INTO THE MOUNTAINS. CONFIDENCE IN THE TIMING OF ANY MESOSCALE CONVECTIVE SYSTEMS GOES DOWN AFTER LATE MONDAY NIGHT...BUT WE WILL RETAIN A FAVORABLE COMBINATION OF SHEAR AND INSTABILITY TO KEEP A THREAT OF SEVERE STORMS THROUGH TUESDAY ACROSS MOST OF THE FCST AREA...WITH PERHAPS THE EXCEPTION OF THE WRN NC MTNS...AND INTO WEDNESDAY EAST OF THE MOUNTAINS. ONE MIGHT EXPECT A BIT OF A LULL OR RECHARGE PERIOD TUESDAY MORNING...BEFORE MORE ORGANIZED SEVERE WEATHER AFFECTS THE REGION TUESDAY AFTERNOON AND EVENING WITH DIURNAL ENHANCEMENT. CAPE PROFILES SUGGEST THAT WE MIGHT HAVE A BIT LESS OF A CHANCE OF SUPERCELLS AND THE LIKE...BECAUSE OF CONVECTIVE DEBRIS/ OVERTURNING...BUT STILL ENOUGH OF A TORNADO THREAT FOR CONTINUED CONCERN BECAUSE OF THE SHEAR. ADDITIONAL DETAILS WILL HOPEFULLY COME MORE INTO FOCUS WITH SUBSEQUENT FCST PACKAGES. AT ANY RATE...PRECIP CHANCES RAMP UP STEADILY FROM THE WEST INTO THE LIKELY TO CATEGORICAL RANGE MONDAY NIGHT AND INTO TUESDAY AND TUESDAY NIGHT. THE LATEST QPF GUIDANCE FROM WPC IS VERY TROUBLESOME. ON THE ONE HAND...ANOMALY GUIDANCE DOES NOT SHOW ANYTHING OVERLY ALARMING WITH REGARD TO PRECIPITABLE WATER...BUT ON THE OTHER HAND THE SLOW MOVING NATURE OF THE COLD FRONT WILL PERMIT WAVES OF MODERATE TO HEAVY RAIN STARTING EARLY TUESDAY MORNING...AND CONTINUING INTO WEDNESDAY. UNLESS THERE IS SOME CHANGE IN THINKING... THE NEED FOR A FLOOD WATCH IS NEARLY A FOREGONE CONCLUSION...BUT THE MAIN THREAT OF FLOODING DOES NOT RAMP UP UNTIL DURING THE DAY ON TUESDAY BASED ON THE QPF BREAKDOWN. SINCE THIS IS THE 4TH FCST PERIOD AND WE HAVE SOME TIME TO GAIN MORE CONFIDENCE... WILL HOLD OFF ON A FLOOD WATCH FOR ONE MORE FCST CYCLE. MODEL GUIDANCE SHOWS THE FRONT CROSSING THE FCST AREA WEDNESDAY EVENING AND THAT SHOULD BRING AN END TO MOST OF THE PRECIP...WITH SOME LINGERING SHOWERS POSSIBLE ON THE TN BORDER OVER THE NRN MTNS. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 1 PM SUNDAY...EXPANSIVE UPPER TROUGH WILL REMAIN OVER THE ERN CONUS THROUGH THE MEDIUM RANGE...WITH THE FLOW EVENTUALLY FLATTENING BY THE END OF NEXT WEEKEND. FAIRLY UNSETTLED CONDITIONS WILL CONTINUE ACRS THE SOUTHEAST REGION UNTIL THAT TIME. FRONTAL BOUNDARY LAYS OUT JUST OFFSHORE FRIDAY. GFS/EC/GEM AGREE ON A SHORTWAVE ROUNDING THE LARGER SCALE TROUGH AND BRINGING A WAVE OUT OF THE GULF OF MEXICO ALONG THE FRONT. THEY DISAGREE HOWEVER ON THE TIMING OF THIS EVENT. 12Z GFS/GEM DEVELOP ONLY A WEAK WAVE FRIDAY...AND HAVE A LOW IMPACT ON OUR CWFA WITH VERY LITTLE QPF. ORIENTATION OF THE FRONT ON THE 00Z EC LEADS IT TO DEVELOP A STRONGER WAVE AND BRING ANOTHER ROUND OF PRECIP TO THE PIEDMONT FRIDAY NIGHT AND SATURDAY. GFS CONCURRENTLY DEVELOPS SHOWERS IN THE MTNS AS IT BRINGS THE WAVE ACRS EARLY SATURDAY...WITH ADDITIONAL NW FLOW PRECIP CONTINUING INTO EARLY SUNDAY. THIS IS A PLAUSIBLE SCENARIO THOUGH IT IS THE ONLY MODEL SHOWING IT. QPF FROM THIS ACTIVITY IS NOTABLE BUT NOT HIGH ENOUGH FOR CONCERN...SO IT WILL BE MINIMALLY REFLECTED IN THE FCST. IN FACT...NCEP/CMC ENSEMBLES GIVE LITTLE SUPPORT TO A WETTER EC-LIKE SOLUTION SO POPS WILL BE KEPT ON THE LOW SIDE FOR THE POTENTIAL FRONTAL WAVE PRECIP...ALONG WITH QPF. AFTER ABV NORMAL TEMPS THU...TEMPS RETURN TO AROUND NORMAL FRI INTO SAT WITH CLOUD COVER. LOWS SUNDAY MRNG SHOULD BE A COUPLE CATEGORIES BELOW NORMAL BUT TEMPS REBOUND SUNDAY UNDER CLEARER SKIES. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... AT KCLT...PUSHED THE TIMING OF THE VFR AND THEN MVFR CIGS BACK 4 TO 6 HOURS. A WEAK BACK DOOR FRONT IS STILL EXPECTED TO TURN THE WINDS LIGHT OUT OF THE EAST OR ENE LATE TONIGHT AND THROUGH MUCH OF THE MORNING HOURS ON MON. AND IT IS POSSIBLE THAT MVFR CIGS WILL ACCOMPANY THE BNDRY...SO I DIDN/T REMOVE THEM...THOUGH I JUST DON/T SEE A LOT TO FORCE LOWER CLOUDS. SHRA/TSTMS ARE EXPECTED TO FIRE UP NEAR THE WEAK SFC FRONT MONDAY AFTN...AND THE PROB30 PERIOD OF THE TAF HAS BEEN PUSHED BACK TO 16-20 UTC TO ACCOUNT FOR THIS. ELSEWHERE...ALSO PUSHED BACK THE TIMING OF LOWERING CIGS AT THE OTHER TAF SITES. AND AT KAVL PUSHED THE TIMING WAY BACK AND DIDN/T GO AS LOW WITH THE CIGS. A FEW SHOWERS ARE POSSIBLE LATER THIS EVENING AND VCSH HAS BEEN ADDED TO A FEW SITES TO ACCOUNT FOR THIS. SHRA/TSTMS ARE EXPECTED TO DEVELOP OVER THE REGION MON AFTN AND EVENING. PUSHED THE PROB30 GROUPS BACK INTO THE LATE AFTN AND EARLY EVENING TO ACCOUNT FOR THIS. THE KHKY AIRFIELD IS EXPECTED TO REMAIN NORTH OF THE WEAK FRONT UNTIL LATE IN THE DAY AND ONLY ADDED PROBS FOR SHOWERS THERE. OUTLOOK...INCREASING MOISTURE WILL BRING PERIODIC CIG AND VSBY RESTRICTIONS IN SHRA/TSRA...AND MORNING FOG. UNSETTLED WEATHER WILL CONTINUE UNTIL A COLD FRONT PASSAGE EARLY THURSDAY. CONFIDENCE TABLE... 02-08Z 08-14Z 14-20Z 20-02Z KCLT HIGH 100% HIGH 96% HIGH 97% HIGH 91% KGSP HIGH 100% HIGH 97% HIGH 97% HIGH 100% KAVL HIGH 100% HIGH 90% HIGH 100% HIGH 91% KHKY HIGH 100% HIGH 95% HIGH 83% HIGH 80% KGMU HIGH 100% HIGH 97% HIGH 97% HIGH 100% KAND HIGH 100% HIGH 92% HIGH 97% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...SBK NEAR TERM...JAT/MCAVOY SHORT TERM...PM LONG TERM...WIMBERLEY AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
747 PM EDT SUN APR 27 2014 .SYNOPSIS... A WET AND STORMY PATTERN WILL SET UP ACROSS THE AREA MONDAY THROUGH WEDNESDAY...FOLLOWED BY COOL AND DRIER HIGH PRESSURE BY THE END OF THE WEEK. && .NEAR TERM /THROUGH MONDAY/... AT 735 PM EDT SUNDAY...BLENDED A POP DERIVED FROM LOCAL CONVECTIVE ALLOWING MODELS AND THE OFFICIAL FORECAST TO GO WITH A SMALL AREA OF HIGH CHANCE AND LIKELY POPS FROM THE UPSTATE INTO THE SRN AND CENTRAL NC MTNS. THE 18 UTC NAM HAD A LITTLE BETTER ELEVATED CAPE ACROSS THIS AREA AND THE HRRR AND WRF-ARW ARE INCREASES CONVECTIVE COVERAGE OVER THIS AREA LATER TONIGHT. OTHERWISE...INCREASED SKY COVER AND MADE SOME MINOR TWEAKS TO THE REST OF THE GRIDS. AT 430 PM EDT SUNDAY...ADJUSTED SKY GRIDS TO ACCOUNT FOR ENCROACHING HIGH CLOUDS AS WELL AS A CU DECK THAT IS DEVELOPING ACROSS NE GA...THE SW NC MTNS AND THE WRN UPSTATE. SOME OF THE MESOSCALE MODELS BRING ELEVATED CONVECTION ACROSS THE FORECAST AREA OVERNIGHT AS THE LEADING EDGE OF THE ELEVATED MIXED LAYER WORKS IN FROM THE WEST. I DON/T SEE MUCH MUCAPE ON THE 18 UTC NAM...SO THINK MOST OF THE ACTIVITY WILL BE WEAK. I WON/T ADJUST THE OVERNIGHT GRIDS JUST YET..BUT I NEED TO RAMP UP POPS WITH SUBSEQUENT UPDATES. AT 200 PM EDT SUNDAY...A NEGATIVELY TILTED UPPER TROUGH WILL SLOWLY PROGRESS ACROSS THE SOUTHERN APPALACHIANS AND GREAT LAKES TONIGHT... WHILE A CLOSED UPPER LOW MOVES NE ACROSS THE GREAT PLAINS. THE RIDGE AXIS MOVES EAST OF THE MOUNTAINS ON MONDAY...WHILE THE UPPER LOW DRIFTS BACK SOUTH OVER THE PLAINS. ISENTROPIC UPGLIDE WILL SPREAD ACROSS THE UPPER SAVANNAH RIVER VALLEY AND SOUTHERN APPALACHIANS LATE THIS AFTERNOON AND THIS EVENING. INSTABILITY SHOULD BECOME SUFFICIENT FOR CONVECTION TO FORM BEFORE EVENING...HOWEVER NEITHER SHEAR NOR INSTABILITY APPEAR IMPRESSIVE. A BACK DOOR COLD FRONT WILL SETTLE SOUTH ACROSS WESTERN NC TONIGHT...REACHING THE SC BORDER EAST OF THE MOUNTAINS BY DAYBREAK. THE BOUNDARY WILL BECOME A FOCUS FOR CONVECTIVE ACTIVITY ON MONDAY...WHEN BETTER SHEAR AND INSTABILITY WILL BE PRESENT. SPC HAS OUR ENTIRE AREA IN A SLIGHT RISK FOR SEVERE WEATHER ON DAY TWO...MENTIONING AN ENVIRONMENT FAVORABLE FOR SUPERCELLS. THE AREA NORTH OF INTERSTATE 40 MAY REMAIN UNFAVORABLE FOR CONVECTION DURING THE DAYLIGHT HOURS ON MONDAY...AS COOL NE FLOW PREVAILS BEHIND THE FRONT...AND A CAP REMAINS AT AROUND 875 MB. WITH THE BEST GULF INFLOW STILL WELL TO THE WEST...EXCESSIVE RAINFALL IS NOT EXPECTED...HOWEVER INDIVIDUAL STORMS MAY PUT DOWN LOCALLY HEAVY RAINFALL. MINIMUM TEMPERATURES WILL BE WELL ABOVE NORMAL UNDER INCREASING CLOUDS COVER AND THE UPPER RIDGE. HIGH TEMPERATURES ON MONDAY WILL RUN SLIGHTLY ABOVE NORMAL...AS CLOUD COVERAGE OFFSETS THE INFLUENCE OF THE UPPER RIDGE. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... AS OF 235 PM SUNDAY...NOTHING IN THE NEW GUIDANCE TO CHANGE EARLIER THINKING THAT WE ARE ON A COLLISION COURSE WITH A VERY WET AND VERY STORMY PATTERN DURING THE LATE MONDAY TO WEDNESDAY TIME FRAME. IMPORTANT DETAILS SUCH AS THE TIMING OF ENHANCED SEVERE THUNDERSTORM THREATS...AND STORM TOTAL RAINFALL...STILL REMAIN IN DOUBT. ONE INTERESTING TREND OR POINT OF CONCERN IS BROUGHT TO LIGHT IN THE LATEST NAM MONDAY NIGHT AND EARLY TUESDAY MORNING. A WEDGE BOUNDARY OF SORTS IS INDICATED EVEN FARTHER SOUTH THAN PREVIOUS RUNS...DOWN CLOSER TO THE SC/NC BORDER. THE AIR MASS TO THE SOUTH OF THE BOUNDARY MIGHT BE FAIRLY RICH WITH BUOYANCY. THE SREF HAS A VERY HIGH PROBABILITY OF CAPE GREATER THAN 1000 J/KG LATE IN THE DAY...AND EVEN THE GENERALLY MORE CONSERVATIVE GFS HAS CAPE IN THE 1000 - 1500 J/KG RANGE. SHEAR AND SRH WILL INCREASE STEADILY THROUGH THE EVENING HOURS IN THE PRESENCE OF ADEQUATE BUOYANCY...THUS OUR CHANCES FOR ORGANIZED SEVERE THUNDERSTORMS WILL ALSO INCREASE. AGREE WITH THE EXPANSION OF THE DAY2 SLIGHT RISK FURTHER EAST IN THE NEW OUTLOOK. IF THE WEST TO EAST ORIENTED BOUNDARY REMAINS IN THE AREA...THIS COULD PROVIDE THE FOCUS FOR SEVERE STORMS AND TORNADIC ACTIVITY SOMEWHERE IN THE CAROLINAS WELL INTO THE OVERNIGHT HOURS. THERE IS ALSO THE CONCERN THAT SUPERCELLULAR CONVECTION MOVING IN FROM GEORGIA DURING THE EVENING WILL GET A SHOT OF INCREASED SHEAR AS IT INTERACTS WITH A BOUNDARY. AT THE SAME TIME...THE FRONTAL ZONE OF HEAVIER RAIN WILL MOVE INTO THE MOUNTAINS. CONFIDENCE IN THE TIMING OF ANY MESOSCALE CONVECTIVE SYSTEMS GOES DOWN AFTER LATE MONDAY NIGHT...BUT WE WILL RETAIN A FAVORABLE COMBINATION OF SHEAR AND INSTABILITY TO KEEP A THREAT OF SEVERE STORMS THROUGH TUESDAY ACROSS MOST OF THE FCST AREA...WITH PERHAPS THE EXCEPTION OF THE WRN NC MTNS...AND INTO WEDNESDAY EAST OF THE MOUNTAINS. ONE MIGHT EXPECT A BIT OF A LULL OR RECHARGE PERIOD TUESDAY MORNING...BEFORE MORE ORGANIZED SEVERE WEATHER AFFECTS THE REGION TUESDAY AFTERNOON AND EVENING WITH DIURNAL ENHANCEMENT. CAPE PROFILES SUGGEST THAT WE MIGHT HAVE A BIT LESS OF A CHANCE OF SUPERCELLS AND THE LIKE...BECAUSE OF CONVECTIVE DEBRIS/ OVERTURNING...BUT STILL ENOUGH OF A TORNADO THREAT FOR CONTINUED CONCERN BECAUSE OF THE SHEAR. ADDITIONAL DETAILS WILL HOPEFULLY COME MORE INTO FOCUS WITH SUBSEQUENT FCST PACKAGES. AT ANY RATE...PRECIP CHANCES RAMP UP STEADILY FROM THE WEST INTO THE LIKELY TO CATEGORICAL RANGE MONDAY NIGHT AND INTO TUESDAY AND TUESDAY NIGHT. THE LATEST QPF GUIDANCE FROM WPC IS VERY TROUBLESOME. ON THE ONE HAND...ANOMALY GUIDANCE DOES NOT SHOW ANYTHING OVERLY ALARMING WITH REGARD TO PRECIPITABLE WATER...BUT ON THE OTHER HAND THE SLOW MOVING NATURE OF THE COLD FRONT WILL PERMIT WAVES OF MODERATE TO HEAVY RAIN STARTING EARLY TUESDAY MORNING...AND CONTINUING INTO WEDNESDAY. UNLESS THERE IS SOME CHANGE IN THINKING... THE NEED FOR A FLOOD WATCH IS NEARLY A FOREGONE CONCLUSION...BUT THE MAIN THREAT OF FLOODING DOES NOT RAMP UP UNTIL DURING THE DAY ON TUESDAY BASED ON THE QPF BREAKDOWN. SINCE THIS IS THE 4TH FCST PERIOD AND WE HAVE SOME TIME TO GAIN MORE CONFIDENCE... WILL HOLD OFF ON A FLOOD WATCH FOR ONE MORE FCST CYCLE. MODEL GUIDANCE SHOWS THE FRONT CROSSING THE FCST AREA WEDNESDAY EVENING AND THAT SHOULD BRING AN END TO MOST OF THE PRECIP...WITH SOME LINGERING SHOWERS POSSIBLE ON THE TN BORDER OVER THE NRN MTNS. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 1 PM SUNDAY...EXPANSIVE UPPER TROUGH WILL REMAIN OVER THE ERN CONUS THROUGH THE MEDIUM RANGE...WITH THE FLOW EVENTUALLY FLATTENING BY THE END OF NEXT WEEKEND. FAIRLY UNSETTLED CONDITIONS WILL CONTINUE ACRS THE SOUTHEAST REGION UNTIL THAT TIME. FRONTAL BOUNDARY LAYS OUT JUST OFFSHORE FRIDAY. GFS/EC/GEM AGREE ON A SHORTWAVE ROUNDING THE LARGER SCALE TROUGH AND BRINGING A WAVE OUT OF THE GULF OF MEXICO ALONG THE FRONT. THEY DISAGREE HOWEVER ON THE TIMING OF THIS EVENT. 12Z GFS/GEM DEVELOP ONLY A WEAK WAVE FRIDAY...AND HAVE A LOW IMPACT ON OUR CWFA WITH VERY LITTLE QPF. ORIENTATION OF THE FRONT ON THE 00Z EC LEADS IT TO DEVELOP A STRONGER WAVE AND BRING ANOTHER ROUND OF PRECIP TO THE PIEDMONT FRIDAY NIGHT AND SATURDAY. GFS CONCURRENTLY DEVELOPS SHOWERS IN THE MTNS AS IT BRINGS THE WAVE ACRS EARLY SATURDAY...WITH ADDITIONAL NW FLOW PRECIP CONTINUING INTO EARLY SUNDAY. THIS IS A PLAUSIBLE SCENARIO THOUGH IT IS THE ONLY MODEL SHOWING IT. QPF FROM THIS ACTIVITY IS NOTABLE BUT NOT HIGH ENOUGH FOR CONCERN...SO IT WILL BE MINIMALLY REFLECTED IN THE FCST. IN FACT...NCEP/CMC ENSEMBLES GIVE LITTLE SUPPORT TO A WETTER EC-LIKE SOLUTION SO POPS WILL BE KEPT ON THE LOW SIDE FOR THE POTENTIAL FRONTAL WAVE PRECIP...ALONG WITH QPF. AFTER ABV NORMAL TEMPS THU...TEMPS RETURN TO AROUND NORMAL FRI INTO SAT WITH CLOUD COVER. LOWS SUNDAY MRNG SHOULD BE A COUPLE CATEGORIES BELOW NORMAL BUT TEMPS REBOUND SUNDAY UNDER CLEARER SKIES. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... AT KCLT...PUSHED THE TIMING OF THE VFR AND THEN MVFR CIGS BACK 4 TO 6 HOURS. A WEAK BACK DOOR FRONT IS STILL EXPECTED TO TURN THE WINDS LIGHT OUT OF THE EAST OR ENE LATE TONIGHT AND THROUGH MUCH OF THE MORNING HOURS ON MON. AND IT IS POSSIBLE THAT MVFR CIGS WILL ACCOMPANY THE BNDRY...SO I DIDN/T REMOVE THEM...THOUGH I JUST DON/T SEE A LOT TO FORCE LOWER CLOUDS. SHRA/TSTMS ARE EXPECTED TO FIRE UP NEAR THE WEAK SFC FRONT MONDAY AFTN...AND THE PROB30 PERIOD OF THE TAF HAS BEEN PUSHED BACK TO 16-20 UTC TO ACCOUNT FOR THIS. ELSEWHERE...ALSO PUSHED BACK THE TIMING OF LOWERING CIGS AT THE OTHER TAF SITES. AND AT KAVL PUSHED THE TIMING WAY BACK AND DIDN/T GO AS LOW WITH THE CIGS. A FEW SHOWERS ARE POSSIBLE LATER THIS EVENING AND VCSH HAS BEEN ADDED TO A FEW SITES TO ACCOUNT FOR THIS. SHRA/TSTMS ARE EXPECTED TO DEVELOP OVER THE REGION MON AFTN AND EVENING. PUSHED THE PROB30 GROUPS BACK INTO THE LATE AFTN AND EARLY EVENING TO ACCOUNT FOR THIS. THE KHKY AIRFIELD IS EXPECTED TO REMAIN NORTH OF THE WEAK FRONT UNTIL LATE IN THE DAY AND ONLY ADDED PROBS FOR SHOWERS THERE. OUTLOOK...INCREASING MOISTURE WILL BRING PERIODIC CIG AND VSBY RESTRICTIONS IN SHRA/TSRA...AND MORNING FOG. UNSETTLED WEATHER WILL CONTINUE UNTIL A COLD FRONT PASSAGE EARLY THURSDAY. CONFIDENCE TABLE... 23-05Z 05-11Z 11-17Z 17-23Z KCLT HIGH 100% MED 62% MED 67% HIGH 84% KGSP HIGH 100% MED 62% MED 66% MED 78% KAVL MED 62% LOW 55% LOW 54% MED 78% KHKY HIGH 100% MED 63% HIGH 94% MED 66% KGMU HIGH 100% MED 62% MED 66% MED 78% KAND HIGH 100% MED 62% MED 62% HIGH 80% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...SBK NEAR TERM...JAT/MCAVOY SHORT TERM...PM LONG TERM...WIMBERLEY AVIATION...MCAVOY
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
946 PM MDT SUN APR 27 2014 .UPDATE... ISSUED AT 939 PM MDT SUN APR 27 2014 DECIDED TO START HIGH WIND WARNING SINCE THE AREA IN THE WATCH WAS ALREADY IN WARNING CRITERIA...KRAP GUST TO 52KT AT 0202Z. LOOKING AT LATEST HI RES MODEL GUIDANCE...HRRR AND RAP...LOOKS LIKE 30 TO 40 MPH WINDS WILL CONTINUE THRU THE NIGHT BEFORE REALLY PICKING UP BY 13Z MONDAY. SEEING VERY STRONG DOWNSLOPE WINDS FROM THE BLACK HILLS IN THE HIGH WIND WARNING AREA. COULD SEE SOME LIGHTER WINDS OVERNIGHT...HOWEVER SINCE WE WERE ALREADY HAVING HIGH WINDS AND CONFIDENCE IN HIGH WINDS FOR MONDAY AND TUESDAY WERE HIGH...DECIDED TO GO WITH THE WARNING. UPDATE ISSUED AT 822 PM MDT SUN APR 27 2014 DECIDED TO PUT OUT A WINTER WEATHER ADVISORY FOR SNOW FOR SHANNON AND BENNETT COUNTIES. MADE A FEW CALLS AND LOOKING AT WEBCAMS MARTIN ALREADY HAD AN INCH AND PINE RIDGE HAD A COUPLE INCHES. LATEST RAP MODEL AND HRRR BOTH INDICATE A TROWAL SETTING UP OVER THIS AREA TONIGHT. EXPECT A BAND OF HEAVY SNOW WITH AMOUNTS OF 2 TO 5 INCHES FOR THIS AREA. ONLY HAVE THE ADVISORY TIL 12Z...BUT SNOW MAY CONTINUE A BIT LONGER. ONCE THE SNOW STOPS THE WINDS WILL START IN THIS AREA SO KEPT WIND ADVISORY BEGINNING AT 12Z. NEXT SHIFT MAY HAVE TO ADJUST THE TIMING DEPENDING ON THE SNOWFALL. UPDATE ISSUED AT 640 PM MDT SUN APR 27 2014 LATEST HRRR MODEL AND SURFACE ANALYSIS SHOWS A LEE MESO-LOW OVER CENTRAL CUSTER COUNTY. THE ISOBARS SHOW A TIGHT GRADIENT OVER WESTERN FALL RIVER COUNTY AND ALONG THE EASTERN FOOTHILLS FROM RAPID CITY TO HERMOSA AND ABOUT 60 MILES EAST ONTO THE PLAINS. THIS FEATURE IS PROGGED TO CONTINUE THROUGH 02Z-03Z THIS EVENING. THE RESULT WILL BE A BRIEF PERIOD OF GUSTY NORTHWEST WINDS OF 35 TO 40 MPH AND GUSTS UP TO 55 MPH. SINCE THIS FEATURE IS VERY LOCALIZED AND WILL BE SHORT LIVED WITH WINDS DIMINISHING AFTER 03Z BEFORE INCREASING AGAIN EARLY MONDAY MORNING...THOUGHT IT WOULD BE BEST COVERED WITH A SPECIAL WEATHER STATEMENT INSTEAD OF GOING WITH A WIND ADVISORY OR HIGH WIND WARNING. OTHERWISE THE FORECAST IS ON TRACK...AM WATCHING THE NORTHERN HILLS CLOSELY SINCE SOME AREAS HAVE ALREADY PICKED UP A FEW INCHES OF SNOW. HOWEVER WINTER STORM WARNING AT THE HIGHER ELEVATIONS AND WINTER WEATHER ADVISORY AROUND SPEARFISH LOOK TO BE GOOD AT THIS TIME. && .SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT ISSUED AT 219 PM MDT SUN APR 27 2014 CURRENT SURFACE ANALYSIS PLACES LOW OVER NWRN KANSAS/SWRN NEBRASKA...WHILE UPPER LEVEL ANALYSIS INDICATES LOW HAS BECOME STACKED. TWO MAIN AREAS OF PRECIP HAVE DEVELOPED OVER THE CWA WITH THE FIRST ONE ORIENTATED N/S ALONG THE WRN SD BORDER ALONG AREA OF STRONG MID-LEVEL FRONTOGENESIS WHILE SECONDARY AREA OF PRIMARILY THUNDERSTORMS CONTINUES TO PUSH W/NWRLY NEAR NOSE OF JET STREAK. FOR THE REST OF THIS AFTERNOON INTO TONIGHT...A POTPOURRI OF WEATHER TYPES ARE EXPECTED AS STRONG LOW PRESSURE SYSTEM CREEPS ITS WAY THROUGH THE REGION. LATEST GUIDANCE KEEPING THE SYSTEM A BIT FURTHER SOUTH THAN PREVIOUSLY THOUGHT WITH LOW SLOWLY SHIFTING THROUGH THE NIGHT TOWARDS CTRL NEBRASKA. PLENTY OF MOISTURE WILL CONTINUE TO WRAP INTO THE SYSTEM KEEPING PRECIPITATION GOING THROUGH THE NIGHT. KEY FORECAST CHALLENGE IS PRECIP TYPES. APPEARS CHANGEOVER TO SNOW HAS OCCURRED OVER THE BLKHLS FOLLOWING A COOLER SOLUTION GIVEN THE SOUTHERN TREND OF THE MODELS. WITH SNOW EXPECTED TO CONTINUE GIVEN LARGE SCALE FORCING ALONG WITH UPSLOPE ENHANCEMENT HAVE UPGRADED TO WINTER STORM WARNING. TOWARDS THE ERN CWA MODELS CONTINUE TO INDICATE MODEST INSTABILITY SO WILL KEEP THUNDERSTORM CHANCES GOING INTO EVENING. THE TRICKY PART IS THE REMAINDER OF THE CWA WHERE TEMPERATURES ARE EXPECTED TO BE RIGHT NEAR THE RAIN/SNOW TRANSITION. HAVE KEEP SNOW ACCUMULATIONS TONIGHT OVER THE PLAINS ON THE LIGHTER SIDE BUT WILL RE-EVALUATE THIS THRU THE AFTERNOON/EVE BECAUSE IF ENOUGH COLD AIR PULLS IN RESULTING IN AN EARLY TRANSITION MORE SNOW WILL NEED TO BE ADDED. ON MONDAY...LOW SLOWLY LOITERS ITS WAY TOWARDS ERN NEBRASKA WITH PRECIPITATION CONTINUING TO AFFECT THE AREA. NEW CONCERN ADDED TO THE EQUATION WILL BE WINDS WITH PRESSURE GRADIENT TIGHTENING OVER THE AREA. GUSTY WINDS WILL BE ON THE INCREASE IN THE MORNING...WITH THE STRONGEST WINDS OVER THE ERN SIDE OF THE BLACK HILLS. PRECIP TYPES REMAIN TRICKY GIVEN THE TEMPS REMAINING NEAR THE TRANSITION...BUT CURRENTLY LOOKS AS IF MOST AREAS SHOULD BE RAIN IN THE AFTERNOON. MONDAY NIGHT...LOW WORKS ITS WAY TOWARDS THE IOWA/MISSOURI BORDER OVERNIGHT. EXPECT COOLER AIR TO WORK INTO THE SYSTEM BRINGING A PROBABLE TRANSITION TOWARDS SNOW TO MOST AREAS...THOUGH PRECIP RATES SHOULD BE LOWER...PARTICULARLY OVER THE FAR WRN CWA WITH THE SYSTEM SLOWLY PUSHING EAST. && .LONG TERM...TUESDAY THROUGH SUNDAY ISSUED AT 219 PM MDT SUN APR 27 2014 CLOSED UPPER LOW WILL SLOWLY MEANDER EAST IN THE PERIOD...SUPPORTING SEMI-BLOCKED FLOW. HEAVY NON-PROGRESSIVE TENDENCIES FAVORED IN THE PERIOD WITH COOL BELOW NORMAL TEMPS EXPECTED. LINGERING WANING DEFORMATION ZONE WILL BE PRESENT OVER THE FA AT THE START OF THE PERIOD...SUPPORTING SNOW ACCUMULATIONS AT SOME LOCATIONS. ALTHOUGH THIS SYSTEM WILL SHIFT EAST SLOWLY THE REMAINDER OF THE PERIOD...CYCLONIC FLOW WITH STEEP LAPSE RATES WILL LINGER THROUGH MUCH OF THE PERIOD BEFORE THE WESTERN NOAM RIDGE BEGINS TO EDGE EAST. HOWEVER...GIVEN THE HIGH AMPLITUDE NATURE OF THE UPPER RIDGE...WITH HIGH LATITUDINAL EXTENT...LONG TRAJECTORY NORTHERLY FLOW WILL SET THE STAGE FOR ANOTHER INTRUSION OF CP TOWARD THE END OF THE PERIOD. THIS HAS FAVORED A DOWNWARD TREND IN TEMPS IN THE SUNDAY PERIOD. GIVEN H85 TEMPS IN THE -2 TO 0C RANGE WITH A PASSING DISTURBANCE...SNOW ACCUMS MAY BE A POSSIBILITY ONCE AGAIN...ESP IN THE HIGHER TERRAIN. TUE-THU...LINGERING DEFORMATION ZONE WILL SUPPORT CHANCES FOR LIGHT RAIN/SNOW...ESP IN THE TUE PERIOD...WITH A HEAVY WANE IN ACTIVITY TOWARD WED GIVEN EAST PROPAGATION OF THE UPPER LOW WITH DRY AIR ADV INTO THE FA FORM THE NORTH. HOWEVER...LINGERING CYCLONIC FLOW WITH STEEP LL LAPSE RATES AND AVAILABLE LL MOISTURE WILL BE SUFFICIENT FOR A FEW SHOWERS INTO THUR. ADJUSTED TEMPS DOWN SOME...ESP TUE GIVEN PRECIP WITH AMPLE CLOUD CLOVER AND COOL THERMAL FIELDS. MODERATE SNOW ACCUMS ARE EXPECTED INTO TUE MORNING OVER THE NORTHERN BLACK HILLS...WITH SOME LIGHT ACCUMS ON THE SD PLAINS...UP TO AN INCH OR SO. THU-SUN...SLIGHT WARMING TREND THROUGH FRIDAY WITH LINGERING LOW CHANCES FOR SHOWERS THU. RIDGE FRONT DISTURBANCE LOOKS TO SHIFT SE INTO THE REGION FRI...POSSIBLY SUPPORTING A FEW SHOWERS WITH PEAK HEATING. OTHERWISE...A POTENTIALLY STRONGER SYSTEM LOOKS TO AFFECT THE REGION INTO THE WEEKEND...BRING MORE COOLER WEATHER BY SUNDAY AND THE CHANCE FOR RAIN AND/OR SNOW ONCE AGAIN. GIVEN AVAILABILITY OF COLD AIR PER HIGH LATITUDE RIDGING...THE POTENTIAL WILL EXIST FOR SOME SNOW ACCUMS. && .AVIATION...FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING ISSUED AT 549 PM MDT SUN APR 27 2014 SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE PERIOD WITH WIDESPREAD IFR CONDITIONS OVER THE BLACK HILLS AND SD PLAINS. DOWNSLOPING SHOULD CONFINE CIGS TO MVFR AT KRAP THROUGH MOST OF THE PERIOD. GUSTY NORTHWESTERLY WINDS WILL CONTINUE TO INCREASE OVERNIGHT WITH SURFACE WINDS OF 50KT POSSIBLE AROUND KRAP BY MONDAY MORNING. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR SDZ024-028. WINTER WEATHER ADVISORY UNTIL 6 AM MDT MONDAY FOR SDZ042-044. WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ MONDAY TO 6 PM MDT /7 PM CDT/ TUESDAY FOR SDZ001-002-012>014-025-027-032-041>044-046- 047-049. HIGH WIND WARNING UNTIL 6 PM MDT TUESDAY FOR SDZ026-030-031- 072>074. WINTER WEATHER ADVISORY UNTIL NOON MDT MONDAY FOR SDZ025. WY...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR WYZ057. && $$ UPDATE...MLS SHORT TERM...77 LONG TERM...JC AVIATION...MLS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
830 PM MDT SUN APR 27 2014 .UPDATE... ISSUED AT 822 PM MDT SUN APR 27 2014 DECIDED TO PUT OUT A WINTER WEATHER ADVISORY FOR SNOW FOR SHANNON AND BENNETT COUNTIES. MADE A FEW CALLS AND LOOKING AT WEBCAMS MARTIN ALREADY HAD AN INCH AND PINE RIDGE HAD A COUPLE INCHES. LATEST RAP MODEL AND HRRR BOTH INDICATE A TROWAL SETTING UP OVER THIS AREA TONIGHT. EXPECT A BAND OF HEAVY SNOW WITH AMOUNTS OF 2 TO 5 INCHES FOR THIS AREA. ONLY HAVE THE ADVISORY TIL 12Z...BUT SNOW MAY CONTINUE A BIT LONGER. ONCE THE SNOW STOPS THE WINDS WILL START IN THIS AREA SO KEPT WIND ADVISORY BEGINNING AT 12Z. NEXT SHIFT MAY HAVE TO ADJUST THE TIMING DEPENDING ON THE SNOWFALL. UPDATE ISSUED AT 640 PM MDT SUN APR 27 2014 LATEST HRRR MODEL AND SURFACE ANALYSIS SHOWS A LEE MESO-LOW OVER CENTRAL CUSTER COUNTY. THE ISOBARS SHOW A TIGHT GRADIENT OVER WESTERN FALL RIVER COUNTY AND ALONG THE EASTERN FOOTHILLS FROM RAPID CITY TO HERMOSA AND ABOUT 60 MILES EAST ONTO THE PLAINS. THIS FEATURE IS PROGGED TO CONTINUE THROUGH 02Z-03Z THIS EVENING. THE RESULT WILL BE A BRIEF PERIOD OF GUSTY NORTHWEST WINDS OF 35 TO 40 MPH AND GUSTS UP TO 55 MPH. SINCE THIS FEATURE IS VERY LOCALIZED AND WILL BE SHORT LIVED WITH WINDS DIMINISHING AFTER 03Z BEFORE INCREASING AGAIN EARLY MONDAY MORNING...THOUGHT IT WOULD BE BEST COVERED WITH A SPECIAL WEATHER STATEMENT INSTEAD OF GOING WITH A WIND ADVISORY OR HIGH WIND WARNING. OTHERWISE THE FORECAST IS ON TRACK...AM WATCHING THE NORTHERN HILLS CLOSELY SINCE SOME AREAS HAVE ALREADY PICKED UP A FEW INCHES OF SNOW. HOWEVER WINTER STORM WARNING AT THE HIGHER ELEVATIONS AND WINTER WEATHER ADVISORY AROUND SPEARFISH LOOK TO BE GOOD AT THIS TIME. && .SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT ISSUED AT 219 PM MDT SUN APR 27 2014 CURRENT SURFACE ANALYSIS PLACES LOW OVER NWRN KANSAS/SWRN NEBRASKA...WHILE UPPER LEVEL ANALYSIS INDICATES LOW HAS BECOME STACKED. TWO MAIN AREAS OF PRECIP HAVE DEVELOPED OVER THE CWA WITH THE FIRST ONE ORIENTATED N/S ALONG THE WRN SD BORDER ALONG AREA OF STRONG MID-LEVEL FRONTOGENESIS WHILE SECONDARY AREA OF PRIMARILY THUNDERSTORMS CONTINUES TO PUSH W/NWRLY NEAR NOSE OF JET STREAK. FOR THE REST OF THIS AFTERNOON INTO TONIGHT...A POTPOURRI OF WEATHER TYPES ARE EXPECTED AS STRONG LOW PRESSURE SYSTEM CREEPS ITS WAY THROUGH THE REGION. LATEST GUIDANCE KEEPING THE SYSTEM A BIT FURTHER SOUTH THAN PREVIOUSLY THOUGHT WITH LOW SLOWLY SHIFTING THROUGH THE NIGHT TOWARDS CTRL NEBRASKA. PLENTY OF MOISTURE WILL CONTINUE TO WRAP INTO THE SYSTEM KEEPING PRECIPITATION GOING THROUGH THE NIGHT. KEY FORECAST CHALLENGE IS PRECIP TYPES. APPEARS CHANGEOVER TO SNOW HAS OCCURRED OVER THE BLKHLS FOLLOWING A COOLER SOLUTION GIVEN THE SOUTHERN TREND OF THE MODELS. WITH SNOW EXPECTED TO CONTINUE GIVEN LARGE SCALE FORCING ALONG WITH UPSLOPE ENHANCEMENT HAVE UPGRADED TO WINTER STORM WARNING. TOWARDS THE ERN CWA MODELS CONTINUE TO INDICATE MODEST INSTABILITY SO WILL KEEP THUNDERSTORM CHANCES GOING INTO EVENING. THE TRICKY PART IS THE REMAINDER OF THE CWA WHERE TEMPERATURES ARE EXPECTED TO BE RIGHT NEAR THE RAIN/SNOW TRANSITION. HAVE KEEP SNOW ACCUMULATIONS TONIGHT OVER THE PLAINS ON THE LIGHTER SIDE BUT WILL RE-EVALUATE THIS THRU THE AFTERNOON/EVE BECAUSE IF ENOUGH COLD AIR PULLS IN RESULTING IN AN EARLY TRANSITION MORE SNOW WILL NEED TO BE ADDED. ON MONDAY...LOW SLOWLY LOITERS ITS WAY TOWARDS ERN NEBRASKA WITH PRECIPITATION CONTINUING TO AFFECT THE AREA. NEW CONCERN ADDED TO THE EQUATION WILL BE WINDS WITH PRESSURE GRADIENT TIGHTENING OVER THE AREA. GUSTY WINDS WILL BE ON THE INCREASE IN THE MORNING...WITH THE STRONGEST WINDS OVER THE ERN SIDE OF THE BLACK HILLS. PRECIP TYPES REMAIN TRICKY GIVEN THE TEMPS REMAINING NEAR THE TRANSITION...BUT CURRENTLY LOOKS AS IF MOST AREAS SHOULD BE RAIN IN THE AFTERNOON. MONDAY NIGHT...LOW WORKS ITS WAY TOWARDS THE IOWA/MISSOURI BORDER OVERNIGHT. EXPECT COOLER AIR TO WORK INTO THE SYSTEM BRINGING A PROBABLE TRANSITION TOWARDS SNOW TO MOST AREAS...THOUGH PRECIP RATES SHOULD BE LOWER...PARTICULARLY OVER THE FAR WRN CWA WITH THE SYSTEM SLOWLY PUSHING EAST. && .LONG TERM...TUESDAY THROUGH SUNDAY ISSUED AT 219 PM MDT SUN APR 27 2014 CLOSED UPPER LOW WILL SLOWLY MEANDER EAST IN THE PERIOD...SUPPORTING SEMI-BLOCKED FLOW. HEAVY NON-PROGRESSIVE TENDENCIES FAVORED IN THE PERIOD WITH COOL BELOW NORMAL TEMPS EXPECTED. LINGERING WANING DEFORMATION ZONE WILL BE PRESENT OVER THE FA AT THE START OF THE PERIOD...SUPPORTING SNOW ACCUMULATIONS AT SOME LOCATIONS. ALTHOUGH THIS SYSTEM WILL SHIFT EAST SLOWLY THE REMAINDER OF THE PERIOD...CYCLONIC FLOW WITH STEEP LAPSE RATES WILL LINGER THROUGH MUCH OF THE PERIOD BEFORE THE WESTERN NOAM RIDGE BEGINS TO EDGE EAST. HOWEVER...GIVEN THE HIGH AMPLITUDE NATURE OF THE UPPER RIDGE...WITH HIGH LATITUDINAL EXTENT...LONG TRAJECTORY NORTHERLY FLOW WILL SET THE STAGE FOR ANOTHER INTRUSION OF CP TOWARD THE END OF THE PERIOD. THIS HAS FAVORED A DOWNWARD TREND IN TEMPS IN THE SUNDAY PERIOD. GIVEN H85 TEMPS IN THE -2 TO 0C RANGE WITH A PASSING DISTURBANCE...SNOW ACCUMS MAY BE A POSSIBILITY ONCE AGAIN...ESP IN THE HIGHER TERRAIN. TUE-THU...LINGERING DEFORMATION ZONE WILL SUPPORT CHANCES FOR LIGHT RAIN/SNOW...ESP IN THE TUE PERIOD...WITH A HEAVY WANE IN ACTIVITY TOWARD WED GIVEN EAST PROPAGATION OF THE UPPER LOW WITH DRY AIR ADV INTO THE FA FORM THE NORTH. HOWEVER...LINGERING CYCLONIC FLOW WITH STEEP LL LAPSE RATES AND AVAILABLE LL MOISTURE WILL BE SUFFICIENT FOR A FEW SHOWERS INTO THUR. ADJUSTED TEMPS DOWN SOME...ESP TUE GIVEN PRECIP WITH AMPLE CLOUD CLOVER AND COOL THERMAL FIELDS. MODERATE SNOW ACCUMS ARE EXPECTED INTO TUE MORNING OVER THE NORTHERN BLACK HILLS...WITH SOME LIGHT ACCUMS ON THE SD PLAINS...UP TO AN INCH OR SO. THU-SUN...SLIGHT WARMING TREND THROUGH FRIDAY WITH LINGERING LOW CHANCES FOR SHOWERS THU. RIDGE FRONT DISTURBANCE LOOKS TO SHIFT SE INTO THE REGION FRI...POSSIBLY SUPPORTING A FEW SHOWERS WITH PEAK HEATING. OTHERWISE...A POTENTIALLY STRONGER SYSTEM LOOKS TO AFFECT THE REGION INTO THE WEEKEND...BRING MORE COOLER WEATHER BY SUNDAY AND THE CHANCE FOR RAIN AND/OR SNOW ONCE AGAIN. GIVEN AVAILABILITY OF COLD AIR PER HIGH LATITUDE RIDGING...THE POTENTIAL WILL EXIST FOR SOME SNOW ACCUMS. && .AVIATION...FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING ISSUED AT 549 PM MDT SUN APR 27 2014 SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE PERIOD WITH WIDESPREAD IFR CONDITIONS OVER THE BLACK HILLS AND SD PLAINS. DOWNSLOPING SHOULD CONFINE CIGS TO MVFR AT KRAP THROUGH MOST OF THE PERIOD. GUSTY NORTHWESTERLY WINDS WILL CONTINUE TO INCREASE OVERNIGHT WITH SURFACE WINDS OF 50KT POSSIBLE AROUND KRAP BY MONDAY MORNING. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR SDZ024-028. WINTER WEATHER ADVISORY UNTIL 6 AM MDT MONDAY FOR SDZ042-044. WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ MONDAY TO 6 PM MDT /7 PM CDT/ TUESDAY FOR SDZ001-002-012>014-025-027-032-041>044-046- 047-049. HIGH WIND WATCH FROM 6 AM MDT MONDAY THROUGH TUESDAY AFTERNOON FOR SDZ026-030-031-072>074. WINTER WEATHER ADVISORY UNTIL NOON MDT MONDAY FOR SDZ025. WY...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR WYZ057. && $$ UPDATE...MLS SHORT TERM...77 LONG TERM...JC AVIATION...MLS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
640 PM MDT SUN APR 27 2014 .UPDATE... ISSUED AT 640 PM MDT SUN APR 27 2014 LATEST HRRR MODEL AND SURFACE ANALYSIS SHOWS A LEE MESO-LOW OVER CENTRAL CUSTER COUNTY. THE ISOBARS SHOW A TIGHT GRADIENT OVER WESTERN FALL RIVER COUNTY AND ALONG THE EASTERN FOOTHILLS FROM RAPID CITY TO HERMOSA AND ABOUT 60 MILES EAST ONTO THE PLAINS. THIS FEATURE IS PROGGED TO CONTINUE THROUGH 02Z-03Z THIS EVENING. THE RESULT WILL BE A BRIEF PERIOD OF GUSTY NORTHWEST WINDS OF 35 TO 40 MPH AND GUSTS UP TO 55 MPH. SINCE THIS FEATURE IS VERY LOCALIZED AND WILL BE SHORT LIVED WITH WINDS DIMINISHING AFTER 03Z BEFORE INCREASING AGAIN EARLY MONDAY MORNING...THOUGHT IT WOULD BE BEST COVERED WITH A SPECIAL WEATHER STATEMENT INSTEAD OF GOING WITH A WIND ADVISORY OR HIGH WIND WARNING. OTHERWISE THE FORECAST IS ON TRACK...AM WATCHING THE NORTHERN HILLS CLOSELY SINCE SOME AREAS HAVE ALREADY PICKED UP A FEW INCHES OF SNOW. HOWEVER WINTER STORM WARNING AT THE HIGHER ELEVATIONS AND WINTER WEATHER ADVISORY AROUND SPEARFISH LOOK TO BE GOOD AT THIS TIME. && .SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT ISSUED AT 219 PM MDT SUN APR 27 2014 CURRENT SURFACE ANALYSIS PLACES LOW OVER NWRN KANSAS/SWRN NEBRASKA...WHILE UPPER LEVEL ANALYSIS INDICATES LOW HAS BECOME STACKED. TWO MAIN AREAS OF PRECIP HAVE DEVELOPED OVER THE CWA WITH THE FIRST ONE ORIENTATED N/S ALONG THE WRN SD BORDER ALONG AREA OF STRONG MID-LEVEL FRONTOGENESIS WHILE SECONDARY AREA OF PRIMARILY THUNDERSTORMS CONTINUES TO PUSH W/NWRLY NEAR NOSE OF JET STREAK. FOR THE REST OF THIS AFTERNOON INTO TONIGHT...A POTPOURRI OF WEATHER TYPES ARE EXPECTED AS STRONG LOW PRESSURE SYSTEM CREEPS ITS WAY THROUGH THE REGION. LATEST GUIDANCE KEEPING THE SYSTEM A BIT FURTHER SOUTH THAN PREVIOUSLY THOUGHT WITH LOW SLOWLY SHIFTING THROUGH THE NIGHT TOWARDS CTRL NEBRASKA. PLENTY OF MOISTURE WILL CONTINUE TO WRAP INTO THE SYSTEM KEEPING PRECIPITATION GOING THROUGH THE NIGHT. KEY FORECAST CHALLENGE IS PRECIP TYPES. APPEARS CHANGEOVER TO SNOW HAS OCCURRED OVER THE BLKHLS FOLLOWING A COOLER SOLUTION GIVEN THE SOUTHERN TREND OF THE MODELS. WITH SNOW EXPECTED TO CONTINUE GIVEN LARGE SCALE FORCING ALONG WITH UPSLOPE ENHANCEMENT HAVE UPGRADED TO WINTER STORM WARNING. TOWARDS THE ERN CWA MODELS CONTINUE TO INDICATE MODEST INSTABILITY SO WILL KEEP THUNDERSTORM CHANCES GOING INTO EVENING. THE TRICKY PART IS THE REMAINDER OF THE CWA WHERE TEMPERATURES ARE EXPECTED TO BE RIGHT NEAR THE RAIN/SNOW TRANSITION. HAVE KEEP SNOW ACCUMULATIONS TONIGHT OVER THE PLAINS ON THE LIGHTER SIDE BUT WILL RE-EVALUATE THIS THRU THE AFTERNOON/EVE BECAUSE IF ENOUGH COLD AIR PULLS IN RESULTING IN AN EARLY TRANSITION MORE SNOW WILL NEED TO BE ADDED. ON MONDAY...LOW SLOWLY LOITERS ITS WAY TOWARDS ERN NEBRASKA WITH PRECIPITATION CONTINUING TO AFFECT THE AREA. NEW CONCERN ADDED TO THE EQUATION WILL BE WINDS WITH PRESSURE GRADIENT TIGHTENING OVER THE AREA. GUSTY WINDS WILL BE ON THE INCREASE IN THE MORNING...WITH THE STRONGEST WINDS OVER THE ERN SIDE OF THE BLACK HILLS. PRECIP TYPES REMAIN TRICKY GIVEN THE TEMPS REMAINING NEAR THE TRANSITION...BUT CURRENTLY LOOKS AS IF MOST AREAS SHOULD BE RAIN IN THE AFTERNOON. MONDAY NIGHT...LOW WORKS ITS WAY TOWARDS THE IOWA/MISSOURI BORDER OVERNIGHT. EXPECT COOLER AIR TO WORK INTO THE SYSTEM BRINGING A PROBABLE TRANSITION TOWARDS SNOW TO MOST AREAS...THOUGH PRECIP RATES SHOULD BE LOWER...PARTICULARLY OVER THE FAR WRN CWA WITH THE SYSTEM SLOWLY PUSHING EAST. && .LONG TERM...TUESDAY THROUGH SUNDAY ISSUED AT 219 PM MDT SUN APR 27 2014 CLOSED UPPER LOW WILL SLOWLY MEANDER EAST IN THE PERIOD...SUPPORTING SEMI-BLOCKED FLOW. HEAVY NON-PROGRESSIVE TENDENCIES FAVORED IN THE PERIOD WITH COOL BELOW NORMAL TEMPS EXPECTED. LINGERING WANING DEFORMATION ZONE WILL BE PRESENT OVER THE FA AT THE START OF THE PERIOD...SUPPORTING SNOW ACCUMULATIONS AT SOME LOCATIONS. ALTHOUGH THIS SYSTEM WILL SHIFT EAST SLOWLY THE REMAINDER OF THE PERIOD...CYCLONIC FLOW WITH STEEP LAPSE RATES WILL LINGER THROUGH MUCH OF THE PERIOD BEFORE THE WESTERN NOAM RIDGE BEGINS TO EDGE EAST. HOWEVER...GIVEN THE HIGH AMPLITUDE NATURE OF THE UPPER RIDGE...WITH HIGH LATITUDINAL EXTENT...LONG TRAJECTORY NORTHERLY FLOW WILL SET THE STAGE FOR ANOTHER INTRUSION OF CP TOWARD THE END OF THE PERIOD. THIS HAS FAVORED A DOWNWARD TREND IN TEMPS IN THE SUNDAY PERIOD. GIVEN H85 TEMPS IN THE -2 TO 0C RANGE WITH A PASSING DISTURBANCE...SNOW ACCUMS MAY BE A POSSIBILITY ONCE AGAIN...ESP IN THE HIGHER TERRAIN. TUE-THU...LINGERING DEFORMATION ZONE WILL SUPPORT CHANCES FOR LIGHT RAIN/SNOW...ESP IN THE TUE PERIOD...WITH A HEAVY WANE IN ACTIVITY TOWARD WED GIVEN EAST PROPAGATION OF THE UPPER LOW WITH DRY AIR ADV INTO THE FA FORM THE NORTH. HOWEVER...LINGERING CYCLONIC FLOW WITH STEEP LL LAPSE RATES AND AVAILABLE LL MOISTURE WILL BE SUFFICIENT FOR A FEW SHOWERS INTO THUR. ADJUSTED TEMPS DOWN SOME...ESP TUE GIVEN PRECIP WITH AMPLE CLOUD CLOVER AND COOL THERMAL FIELDS. MODERATE SNOW ACCUMS ARE EXPECTED INTO TUE MORNING OVER THE NORTHERN BLACK HILLS...WITH SOME LIGHT ACCUMS ON THE SD PLAINS...UP TO AN INCH OR SO. THU-SUN...SLIGHT WARMING TREND THROUGH FRIDAY WITH LINGERING LOW CHANCES FOR SHOWERS THU. RIDGE FRONT DISTURBANCE LOOKS TO SHIFT SE INTO THE REGION FRI...POSSIBLY SUPPORTING A FEW SHOWERS WITH PEAK HEATING. OTHERWISE...A POTENTIALLY STRONGER SYSTEM LOOKS TO AFFECT THE REGION INTO THE WEEKEND...BRING MORE COOLER WEATHER BY SUNDAY AND THE CHANCE FOR RAIN AND/OR SNOW ONCE AGAIN. GIVEN AVAILABILITY OF COLD AIR PER HIGH LATITUDE RIDGING...THE POTENTIAL WILL EXIST FOR SOME SNOW ACCUMS. && .AVIATION...FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING ISSUED AT 549 PM MDT SUN APR 27 2014 SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE PERIOD WITH WIDESPREAD IFR CONDITIONS OVER THE BLACK HILLS AND SD PLAINS. DOWNSLOPING SHOULD CONFINE CIGS TO MVFR AT KRAP THROUGH MOST OF THE PERIOD. GUSTY NORTHWESTERLY WINDS WILL CONTINUE TO INCREASE OVERNIGHT WITH SURFACE WINDS OF 50KT POSSIBLE AROUND KRAP BY MONDAY MORNING. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR SDZ024-028. WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ MONDAY TO 6 PM MDT /7 PM CDT/ TUESDAY FOR SDZ001-002-012>014-025-027-032-041>044-046- 047-049. HIGH WIND WATCH FROM 6 AM MDT MONDAY THROUGH TUESDAY AFTERNOON FOR SDZ026-030-031-072>074. WINTER WEATHER ADVISORY UNTIL NOON MDT MONDAY FOR SDZ025. WY...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR WYZ057. && $$ UPDATE...MLS SHORT TERM...77 LONG TERM...JC AVIATION...MLS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1009 PM CDT SUN APR 27 2014 .UPDATE... SHOWER AND ISOLATED TSTM ACTIVITY NOW CONFINED TO GENERALLY THE NORTHEASTERN HALF OF THE MID STATE. LATEST HRRR SHOWS REDEVELOPMENT OVER OUR NORTHWESTERN COUNTIES AROUND 3 OR 4 AM IN THE MORNING. THE ACTIVITY AT THAT TIME STILL DOES NOT LOOK SEVERE. ELSEWHERE...JUST SCT ACTIVITY IS POSSIBLE. MODELS ARE IN AGREEMENT WITH A BUILDUP OF SUBSIDENCE TOWARD 12Z OVER WESTERN TN. SO...ONSET OF SEVERE MAY HOLD OFF UNTIL AFTER THE 12Z-15Z WINDOW. FOR THIS NEXT UPDATE...WILL BE LOWERING POPS FOR THE REMAINDER OF THE OVERNIGHT. BUT...WILL AT LEAST MAINTAIN LIKELY POPS FOR MUCH OF THE NORTHWEST. ELSEWHERE...WILL GENERALLY KEEP POPS IN THE CHC CATEGORY. OTW...LOW TEMPS LOOK FINE AS DEWPOINTS WILL REMAIN NEARLY STEADY. FOR THE REMAINDER OF THE OVERNIGHT...IT DOES NOT LOOK AS THOUGH ANY SEVERE WEATHER WILL HIT US. BUT...THAT WILL CHANGE AFTER 12Z-15Z. && .PREV DISCUSSION... /ISSUED 805 PM CDT SUN APR 27 2014/ DISCUSSION... CURRENT RADAR IMAGERY SHOWING A LARGE AMOUNT OF REFLECTIVITY COVERAGE IN THE FORM OF SHOWERS AND NON SEVERE TSTMS. MODELS SHOW THAT AN INCREASE IN MOISTURE DEPTH IS EXPECTED THIS EVENING AND OVERNIGHT. WILL GO AHEAD AND UP POPS AREA WIDE. OTW...IN TERMS OF THE SEVERE POTENTIAL ANALYSIS...LATEST SOUNDING FOR OHX IS IN NOW. CURRENT LI IS + 1.8 AND SUPPORTS THE RELATIVELY STABLE CONDITIONS ACROSS MIDDLE TN AT THIS TIME. THE FURTHER WEST YOU GO HOWEVER...INSTABILITIES DO INCREASE. THE CLOSEST SEVERE WARNINGS ARE ACROSS NW MS AND THE BOOTHEEL OF MO. THE ACTIVITY LOOKS ESPECIALLY NASTY IN THE CENTRAL AR AREA. MODELS IN AGREEMENT AND SUPPORT INCREASINGLY UNSTABLE AIR THE FURTHER WEST YOU GO. THROUGH 12Z...WE REALLY SEE NO INCREASE IN INSTABILITY LEVELS OVER MIDDLE AND EASTERN AREAS OF THE MID STATE. HOWEVER...OVER THE WESTERN QUARTER OR SO OF MIDDLE TN...WE DO SEE A SUBSTANTIAL DECREASE IN SHOWALTER VALUES. THE MID AND LOW LEVEL JET DYNAMICS WILL BE ON THE INCREASE OVER WESTERN TN OVERNIGHT AS WELL. ALL IN ALL...LOOKS LIKE NON SEVERE TSTMS OVERNIGHT EXCEPT AS WE APPROACH 12Z...THE RISK OF SEVERE WILL BEGIN TO INCREASE OVER OUR FAR WESTERN AREAS. AGAIN...WILL UP THE POPS FOR ALL AREAS FOR TONIGHT. UPDATES WILL BE SENT SHORTLY. PREV DISCUSSION... /ISSUED 717 PM CDT SUN APR 27 2014/ UPDATE...FOR 00Z TAFS. AVIATION... SIGNIFICANT SYSTEM TO CROSS THE MID-SOUTH THE NEXT 24 HOURS. SHWRS/STMS EXPECTED TO AFFECT ALL SITES OFF AND ON THROUGH THE PERIOD...WHICH WILL BRING A MULTITUDE OF VARYING CONDITIONS. BEST CHANCE FOR STRONGEST STORMS LOOKS TO BE THE 15-00Z RANGE MONDAY. STORMS WILL CONTAIN VERY HEAVY RAIN WHICH WILL GREATLY REDUCES VSBYS AND POSSIBLY CIGS. STRONG STMS LIKELY TO CONTAIN 40+KT WIND GUSTS AS WELL. PREV DISCUSSION... /ISSUED 355 PM CDT SUN APR 27 2014/ AS OF 3 PM...ISOLATED SHOWERS AND STORM DEVELOPMENT CONTINUED NORTH OF THE WARM FRONT AND ITS ASSOCIATED CONVECTION. THE FRONT HAS BEEN VERY SLUGGISH TO PROGRESS NORTHWARD...AND AS A RESULT...HAS RESULTED IN SOME FLASH FLOODING CONCERNS IN NORTHERN MS. THIS ACTIVITY SHOULD CONTINUE TO INCH NORTH THROUGH THE LATE AFTERNOON AND EVENING. STILL THINK THAT HEAVY RAINS...FREQUENT CG STRIKES...AND SOME SMALL HAIL/GUSTY WINDS WILL BE THE THREATS UNTIL NIGHTFALL...THEN ACTIVITY SHOULD MELLOW AS IT EXITS NORTH OF THE STATE LINE. REGARDING THE FORECAST SEVERE LINE OF STORMS THAT HAS BEEN ADVERTISED FOR THE LAST FEW DAYS...HRRR/RAP/WRF HI RES MODELS CONTINUE TO INDICATE A SEVERE LINE OF STORMS THAT SHOULD REACH THE TN RIVER WELL AFTER MIDNIGHT. ALL THE DETERMINISTIC MODELS BLOW THIS SQUALL LINE THROUGH THE MID STATE BY LATE MORNING MONDAY. FOR THE PERIOD 18Z MONDAY THROUGH 06Z TUESDAY... THIS CONTINUES TO BE THE TIMEFRAME IN WHICH THE HIGHEST POTENTIAL FOR SEVERE WEATHER APPEARS TO BE. THE POTENTIAL FOR A WIDESPREAD SEVERE WEATHER OUTBREAK INCLUDING VERY LARGE HAIL AND STRONG...POTENTIALLY NUMEROUS...TORNADOES CONTINUES TO EXIST. AFTER CLOSE EXAMINATION OF THE DETERMINISTIC MODELS...THE ONLY NOTABLE DIFFERENCE FROM PREVIOUS FORECASTS APPEARS TO BE A SOMEWHAT EARLIER POSSIBLE CONVECTIVE INITIATION TIMING ESTIMATE. 12Z-15Z FORECAST SOUNDINGS INDICATE VERY RAPID WARMING AND RAPIDLY INCREASING INSTABILITY PARAMETERS FOR THE WESTERN HALF OF THE MID STATE. SIMULTANEOUSLY...THE RIGHT EXIT REGION OF A 250 MB JET STREAK WILL BE DEVELOPING OVER THE MS RIVER AND SHOULD BE AROUND THE TN RIVER BY 18Z. OMEGA FIELDS ECHO THE IMPLIED DEEP LAYER LIFT DEVELOPING IN WESTERN TN IN THE MORNING AND A VERY STRONG DYNAMIC AND RAPIDLY DEVELOPING CONVECTIVE SET UP LOOKS TO BE IN STORE FOR THE WESTERN TN AND WESTERN MIDDLE TENNESSEE AREAS. THE BIGGEST QUESTION AROUND THIS TIME IS WHERE IN FACT CI WILL TAKE PLACE...AND INTERROGATING SUBTLETIES IN THE WIND FIELDS OF ALL THE PROGGED SFC WIND FIELDS...A SUBTLE SURFACE CONFLUENCE ZONE LOCATED JUST WEST OF THE TN RIVER MAY BE THE LOCATION THAT THIS CI TAKES PLACE. CONFIDENCE IS QUITE LOW IN THAT REGARD HOWEVER. AFTER CI TAKES PLACE...THESE CELLS SHOULD BEGIN TAKING SUPERCELL STRUCTURE AND STEERING FLOW SHOULD BE EAST NORTHEASTERLY AT ABOUT 40-50 KTS. THIS WOULD PUT ALL OF MIDDLE TENNESSEE IN THE PATH OF VERY STRONG SUPERCELLS SHOULD THIS OUTCOME COME TO FRUITION. IF EVERYTHING GOES AS INDICATED IN THE MODELS...THE 21Z TO 03Z TIMEFRAME LOOKS TO BE THE TIMEFRAME OF PEAK THREAT. OVERALL FORECAST LIMITING FACTORS...SOME OF THE VARIABLES THAT CONTINUE TO COMPLICATE THE FORECAST. THERE IS LOWER CONFIDENCE IN THE HI RES MODELS OF LATE DUE TO ITS INABILITY TO ACCURATELY HANDLE THE CONVECTION FROM TODAY. THIS MAKES THE SQUALL LINE POTENTIAL FOR TONIGHT MORE QUESTIONABLE HOWEVER THERE ARE STILL A FEW MORE HOURS OF POTENTIAL DEVELOPMENT OUT WEST. ADDITIONALLY...THE LARGE AMOUNTS OF RAINFALL THAT HAS BEEN OBSERVED IN NORTHERN MS AND WESTERN TN MAY KEEP THE LOW LEVEL ATMOSPHERE QUITE MOIST TOMORROW AND THUS KEEP LOW LEVEL CLOUD COVER IN THE AREA IF THE PREVIOUSLY FORECAST SQUALL LINE DOES NOT COME TO FRUITION AND CLEAR EVERYTHING OUT. THIS WOULD RESULT IN INHIBITED INSTABILITY AND DELAY STORM DEVELOPMENT INTO THE LATER AFTERNOON. WITH THE MULTITUDE OF VARIABLES UNKNOWN DUE TO ONGOING CONVECTION...THESE LIMITING FACTORS ARE DIFFICULT TO ASSESS. ADDITIONALLY...PWAT VALUES SHOULD STAY WELL ABOVE NORMAL THROUGHOUT THE NEXT 48 HOURS. SO IN ADDITION TO THE SEVERE WEATHER POTENTIAL...HEAVY RAIN POTENTIAL AND POSSIBLE FLASH FLOODING WILL BE A SIGNIFICANT THREAT. HPC IS INDICATING AROUND 5 INCHES OF RAIN FROM 00Z TONIGHT THROUGH 00Z WEDNESDAY. NOTE HOWEVER THAT A LARGE PORTION OF THIS RESTS ON WHETHER TONIGHTS STORM SYSTEM DEVELOPS AS FORECAST IN THE SHORT RANGE MODELS. BEYOND 06Z TUESDAY...LEFT FORECAST BASICALLY UNCHANGED WITH ANOTHER POTENTIAL ROUND OF STRONG TO SEVERE WEATHER POSSIBLE TUESDAY AFTERNOON AND EVENING. PREFER NOT TO ADD ANY MORE DETAILS TO THIS FORECAST WITHOUT SEEING HOW TOMORROW UNFOLDS FIRST AS IT WILL DIRECTLY IMPACT WHAT HAPPENS TUESDAY. BUT FOR WHAT ITS WORTH...SPC HAS DOWNGRADED TUESDAYS THREAT FOR MIDDLE TENNESSEE TO ONLY GENERAL THUNDERSTORMS. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
752 PM CDT SUN APR 27 2014 .UPDATE... UPDATE FOR ISOLATED THUNDERSTORMS MOVING TOWARD BURLESON AND WASHINGTON COUNTIES FROM THE WEST. 40 && .DISCUSSION... DRY LINE/COLD FRONT APPROACHING FROM THE WEST. ISOLATED THUNDERSTORMS HAVE DEVELOPED AHEAD OF THE DRY LINE IN BASTROP AND LEE COUNTIES AND WERE MOVING INTO BURLESON AND WASHINGTON COUNTIES. LARGE HAIL HAS BEEN REPORTED...BUT THE STORM MOVING THROUGH BURLESON COUNTY WEAKENED BEFORE MOVING INTO THE COUNTY. THE 00Z CRP SOUNDING HAD A SURFACE BASED CAPE OF ALMOST 4700... ALTHOUGH THERE WAS A DECENT CAP IN PLACE. ISOLATED STRONG TO SEVERE STORMS ARE POSSIBLE THROUGH MID EVENING AS THE STORMS THAT DO DEVELOP MOVE OFF THE DRYLINE...ESPECIALLY ALONG AND NORTH OF A LINE FROM BRENHAM TO HUNTSVILLE. DO EXPECT THE STORMS TO BEGIN LOSING INTENSITY DURING THE LATE EVENING DUE TO THE LOSS OF DAYTIME HEATING. 40 && .PREV DISCUSSION... /ISSUED 641 PM CDT SUN APR 27 2014/ DISCUSSION... 00Z TAF DISCUSSION IN AVIATION SECTION. AVIATION... SFC ANALYSIS HAS DRYLINE ALONG THE I-35 CORRIDOR WITH A FEW ISO STORMS WEST OF KAUS. CAP EAST OF THESE STORMS PROBABLY STRONG ENOUGH THAT THE STORMS SHOULD WEAKEN BEFORE REACHING KCLL SO WILL CONTINUE TO MONITOR. LEFT TAF VOID OF CONVECTION AS PROBABILITIES SMALL AT THIS POINT. MAIN CONCERN WILL BE LOW MVFR CIGS AHEAD OF WEAK PACIFIC FRONT. DRIER AIR SHOULD MIX INTO THE AREA BY THE MORNING HOURS AND HELP SCT OUT CIGS 12-15Z WITH MAINLY CLEAR SKIES AFTER THAT. WINDS SHOULD TURN TO THE WSW/WNW DIRECTIONS AROUND 10KTS. BOUNDARY SHOULD WORK BACK NORTH MONDAY NIGHT WITH STRONGER PACIFIC FRONT ON TUESDAY. 39 PREV DISCUSSION... /ISSUED 310 PM CDT SUN APR 27 2014/ DISCUSSION... VISIBLE SATELLITE SHOWS DRY LINE CLEARLY ACROSS CENTRAL TEXAS THIS AFTERNOON. THE DRY LINE IS NOW JUST AT DALLAS- FORT WORTH AND IS EXPECTED TO PUSH EAST THROUGH THE NIGHT. GLOBAL MODELS CONTINUE TO OVER DUE PRECIP ACROSS THE AREA AS THE CAP HAS REMAINED STRONG. A SPECIAL 18Z SOUNDING LAUNCH FROM TEXAS A&M SHOWS A PRETTY STOUT CAP IN PLACE AT 750 MB. CONVECTIVE TEMPERATURE FROM THIS SOUNDING IS IN THE MID 90S WHICH IS VERY UNLIKELY TO OCCUR THIS AFTERNOON. HIGH RES HRRR AND TEXAS TECH WRF STRUGGLE TO DEVELOP PRECIP THIS AFTERNOON INTO EVENING. THE HRRR AND TEXAS TECH WRF DO TRY TO DEVELOP SOMETHING IN HOUSTON COUNTY BUT QUICKLY MOVE IT OFF TO THE NORTHEAST. UPPER LEVEL DIFFLUENCE ALSO APPEARS TO BE NOW MOVING OFF TO THE NORTH AND EAST WITH THE ADVANCING UPPER LEVEL LOW. DUE TO THE MENTIONED ABOVE HAVE TRIMMED BACK POPS AND THE MENTION OF SEVERE. TOMORROW THE DRY LINE WILL STALL OUT ACROSS THE AREA GENERALLY ALONG A LINE FROM WHARTON TO HARRIS TO SAN JACINTO COUNTY. BEHIND THE DRY LINE LIGHT WEST TO NORTHWEST WINDS AND MOSTLY CLEAR SKIES WILL ALLOW TEMPERATURES TO QUICKLY RISE. HIGHS IN THE LOWER 90S LOOKS LIKELY. NEAR THE COAST TEMPERATURES SHOULD REMAIN MORE CHECKED DUE TO ONSHORE WINDS AND HIGHER DEWPOINTS. STILL EXPECT TEMPERATURES TO REACH THE LOWER 80S. TUESDAY MORNING THE DRY LINE WILL START TO RETREAT AS THE NEXT COLD FRONT APPROACHES THE AREA. WITH LIGHT WINDS AND RISING DEWPOINTS CAN`T RULE OUT SOME PATCHY FOG TUESDAY MORNING. THE SURFACE COLD FRONT IS THEN EXPECTED TO SLOWLY PUSH THROUGH THE AREA ON TUESDAY. THE GFS REMAINS VERY QUICK WITH THE FRONT WHILE THE ECMWF... CANADIAN AND NAM 12 ARE SLOWER. HAVE LEANED TOWARDS THE EURO AS FRONTS USUALLY SLOW DOWN IN THE AFTERNOON IN COMBINATION WITH THE OCCLUDING MID- LATITUDE CYCLONE. FOR THE REST OF THE WORK WEEK BELOW NORMAL TEMPERATURES WILL BE THE STORY AS SOUTHEAST TEXAS REMAINS ON THE BACK SIDE OF THE UPPER LEVEL LOW. THURSDAY A SHORT WAVE WILL BEGIN TO DIVE SOUTHWARDS HELPING TO REINFORCE THE LONG WAVE TROUGH. THIS SHORT WAVE WILL PUSH A WEAK WIND SHIFT THROUGH THE AREA. AS THE VORT MAX MOVES SOUTHWARDS MODELS ARE GENERATING SOME QPF. MOISTURE WILL BE LIMITED BUT CAN`T RULE OUT THE CHANCE COMPLETELY. CURRENT FORECAST LOOKS ON TRACK WITH THIS. 23 MARINE... MODERATE TO STRONG ONSHORE WINDS WILL CONTINUE THROUGH TONIGHT UNDER A TIGHT PRESSURE GRADIENT. CAUTION FLAGS ARE UP FOR THE BAYS...AND ADVISORIES ARE IN EFFECT FOR THE COASTAL WATERS. WINDS AND SEAS WILL COME DOWN ON MONDAY AS THE GRADIENT WEAKENS. A STRONG COLD FRONT THAT IS EXPECTED TO BE NEAR THE COAST LATE TUESDAY AFTERNOON OR EARLY TUESDAY EVENING WILL MOVE THROUGH THE WATERS TUESDAY NIGHT. BEHIND THE FRONT... CAUTION FLAGS ARE LIKELY AND ADVISORIES MIGHT BE NEEDED FOR STRENGTHENING NORTH WINDS AND BUILDING SEAS. 42 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 65 91 62 82 51 / 30 10 10 10 10 HOUSTON (IAH) 72 91 68 86 55 / 20 20 10 10 10 GALVESTON (GLS) 73 82 72 82 62 / 20 10 10 20 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 AM CDT MONDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. SMALL CRAFT ADVISORY UNTIL 4 AM CDT MONDAY FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...40 AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
708 PM CDT SUN APR 27 2014 .UPDATE... LATEST MESO-ANALYSIS INDICATED A STATIONARY DRY LINE FROM BONHAM TO MESQUITE TO NEAR CAMERON. MEANWHILE A PACIFIC COLD FRONT WAS JUST A FEW MILES TO ITS WEST...ALONG A LINE SHERMAN TO FORT WORTH TO LAMPASAS. WINDS BEHIND THE FRONT WERE STRONGER AND FROM THE WEST BUT RAPID BOUNDARY LAYER DECOUPLING SHOULD OCCUR IN THE NEXT HOUR WITH WINDS DROPPING BELOW WIND ADVISORY CRITERIA. EXPIRED WIND ADVISORY ON TIME AT 7 PM. MORE CONCERNING WITH THE FORECAST IS THE CONVECTIVE POTENTIAL THIS EVENING. WITH THE SUN SETTING...THE THREAT FOR INITIATION OF SURFACE BASED CONVECTION ALONG THE DRY LINE WILL WANE DUE TO INCREASING CIN AND THE SEVERE WATCH WILL LIKELY EXPIRE AT 8PM. THE DRY LINE WILL MOVE BACK TO THE WEST AFTER SUNSET AS IS OFTEN THE CASE...LIKELY MEETING OR PERHAPS ALSO PUSHING THE PACIFIC FRONT BACKWARD. THE FRONT IS AWAITING A PUSH FROM A STRONG SHORTWAVE THAT WILL ARRIVE LATER THIS EVENING...WITH STRONG UPWARD FORCING BEGINNING TO SPREAD ACROSS THE REGION AFTER 10 PM. WHILE SURFACE BASED CONVECTION FIRING ALONG A WESTWARD RETREATING DRY LINE DURING THE EVENING IS RARE DUE TO INCREASED CIN...IT DOES HAPPEN OCCASIONALLY. INSTEAD WHAT IS LIKELY TO HAPPEN IS THAT UPWARD FORCING OCCURRING IN THE PRESENCE OF NEARLY DRY ADIABATIC LAPSE RATES UP TO 14000 FEET WILL SQUEEZE OUT WHATEVER MOISTURE IT CAN FIND FOR ELEVATED HIGH BASED CONVECTION. MODEL SOUNDINGS FROM THE RAP ARE MOST AGGRESSIVE WITH THIS SCENARIO...AND SUGGEST ISOLATED TO SCATTERED ELEVATED THUNDERSTORMS DEVELOPING ALONG THE I-35 CORRIDOR AND GATHERING STRENGTH AS THEY HEAD INTO THE DEEPER MOISTURE ACROSS THE EASTERN ZONES. OBVIOUSLY ANY STORMS IN THIS ENVIRONMENT WILL HAVE A LARGE HAIL THREAT. WHILE THIS IS A POSSIBLE SCENARIO...IT IS UNCERTAIN RIGHT NOW HOW LIKELY IT IS. THEREFORE WE WILL KEEP POPS AT 20-30 PERCENT THROUGH 1 AM OVER AREAS JUST EAST OF I-35 AND CONTINUE TO WATCH TRENDS IN SATELLITE AND RADAR DATA FOR ADDITIONAL DEVELOPMENT LATER THIS EVENING. TR.92 && .AVIATION... VFR CONDITIONS ARE EXPECTED BUT STILL A SLIGHT POSSIBILITY SOME DUST MAY EFFECT THE METROPLEX SITES...BUT THIS SHOULD REMAIN NORTHWEST OF TAF SITES. OTHERWISE THE DRY LINE IS STATIONARY JUST EAST OF KDAL AND KACT...WITH A PACIFIC COLD FRONT ANALYZED BETWEEN DFW AND FTW/AFW. WINDS BEHIND THE PACIFIC FRONT WERE STRONGER AND MORE WESTERLY BUT WITH SUNSET APPROACHING THESE WINDS SHOULD NOT BE TOO STRONG AND NO CROSSWIND ISSUES ARE EXPECTED AT DFW/DAL THIS EVENING. DRY LINE WILL TRY TO HEAD BACK TO THE WEST AND WINDS MAY BECOME LIGHT SOUTHERLY BEHIND IT FOR DFW/GKY AND ESPECIALLY DAL THIS EVENING. THERE IS SOME CONCERN FOR REDEVELOPMENT OF CONVECTION AND STORMS TONIGHT AS STRONG UPPER FORCING ARRIVES. CONFIDENCE IS LOW BUT STILL A BIT NERVOUS ABOUT FORCING ARRIVING WITH DRY LINE STILL IN THE AREA. WILL SHOW VCTS FOR DAL/ACT FROM 4Z TO 8Z. BELIEVE THIS ACTIVITY...SHOULD IT DEVELOP...WILL BE HIGH BASED ALONG I-35 CORRIDOR...BUT MAY RESULT IN LIGHTNING STRIKES. THE MORE ROBUST CONVECTION SHOULD BE EAST OF TAF SITES LATER TONIGHT...SHOULD IT DEVELOP. WEST WINDS NEAR 10-15KT AND VFR WILL PREVAIL TOMORROW. TR.92 && .PREV DISCUSSION... /ISSUED 319 PM CDT SUN APR 27 2014/ DRYLINE/SURFACE TROUGH CONTINUES MOVING EAST AND CURRENTLY EXTENDED FROM NEAR BONHAM...TO DALLAS...TEMPLE AND WAS MOVING SLOWLY EAST. ONE ISOLATED STRONG STORM WAS UP NEAR BONHAM WITH ANOTHER POTENTIALLY DEVELOPING CELL OVER EASTERN COLLIN CO... OTHERWISE IT REMAINED QUIET. DESPITE SURFACE DEW POINTS BETWEEN 65-70 DEGREES...WARM TEMPERATURES...INSTABILITY ABOVE 2000 J/K AND GOOD SHEAR...LOW LEVEL CONVERGENCE ACROSS OUR CENTRAL TEXAS COUNTIES WAS NOT AS GOOD DUE TO SLIGHTLY VEERED FLOW AHEAD OF THE DRYLINE. THIS MAY CHANGE AS A 300MB SPEED MAX CONTINUES ROTATING NORTHEAST THROUGH 00Z AND HELPS TRIGGER ISOLATED STORMS...POSSIBLY MORE SCATTERED IN THE FAR E/NE FROM CORSICANA/ATHENS NORTHWARD. QUICK CHAT WITH SPC WAS THAT CURRENT SEVERE THUNDERSTORM WATCH 94 WOULD BE ALLOWED TO EXPIRE AT 3 PM AND REPLACED BY SEVERE THUNDERSTORM WATCH 99 FOR OUR FAR EAST CENTRAL AND NORTHEAST COUNTIES THROUGH 8 PM. SEVERE STORMS ARE ALREADY DEVELOPING RAPIDLY AND BECOMING SEVERE BETWEEN BONHAM AND PARIS WITH OTHER SIGNS OF DEVELOPMENT SOUTHWEST TOWARD ROCKWALL AND TERRELL. LOOK FOR A 10-30 PERCENT COVERAGE OF POSSIBLE STRONG TO SEVERE STORMS ACROSS THE EASTERN THIRD OF NORTH TEXAS INTO EARLY EVENING WITH HAIL AND DAMAGING WINDS THE MAIN THREATS DUE TO THE AFOREMENTIONED SLIGHTLY VEERED FLOW AHEAD OF THE DRYLINE. BEHIND THE DRYLINE...GUSTY WEST-SOUTHWEST WINDS 20 TO 30 MPH WITH GUST 35 TO 40 MPH ARE EXPECTED AND MAY RESULT IN SOME BLOWING DUST FROM THE DFW METROPLEX NORTH AND WEST THROUGH MID EVENING. BEYOND MID EVENING...WE EXPECT THE DRYLINE TO REACH OUR EASTERN EDGE AND RISK FOR SEVERE STORMS MOVING INTO EAST TEXAS...THE ARKLATEX AND MID MS VALLEY. DRIER AIR TONIGHT COMBINED WITH DIMINISHING WEST WINDS SHOULD ALLOW FOR A COOL AND PLEASANT NIGHT...BEFORE ANOTHER WINDY... DRY AND VERY WARM DAY ENSUES MONDAY WITH FIRE WEATHER CONCERNS AND POSSIBLY ANOTHER WIND ADVISORY NEEDING TO BE ISSUED. WEST- SOUTHWEST WINDS 15-25 MPH AND GUSTY ARE EXPECTED OR POSSIBLY SLIGHTLY HIGHER BY MONDAY AFTERNOON. THE FIRST OF SEVERAL COLD FRONTAL SURGES IS EXPECTED TO ARRIVE MONDAY NIGHT INTO TUESDAY MORNING. MEANWHILE...ANOTHER STRONG CYCLONICALLY CURVED SHORTWAVE WILL ROTATE ACROSS THE RED RIVER WITH MOST MOISTURE ANCHORED ABOVE 700MB. ONLY MENTIONED ISOLATED HIGH-BASED OR ELEVATED SHOWERS FOR THIS PERIOD...THOUGH EVENTUALLY THUNDER MAY NEED TO BE INTRODUCED IF LAPSE RATES REMAIN HIGH. THE LOW LEVELS WILL REMAIN VERY DRY...SO LITTLE MEASURABLE RAINFALL WOULD OCCUR WITH THE FRONTAL PASSAGE. MAY WELL BE JUST SOME VIRGA WOULD COULD POSSIBLY TRANSLATE SOME GUSTIER NORTHWEST WINDS DOWN THE SURFACE BY TUESDAY MORNING. AFTERWARD...A DRY AND SEASONABLY COOL PERIOD IS EXPECTED WITH THE DRY CONTINENTAL AIRMASS BEING SUPPORTED BY STALLING AND OCCLUDING UPPER LOW PIN-BALLING OVER THE MID MISSISSIPPI VALLEY AND MIDWEST. AS NOTED IN PREVIOUS DISCUSSIONS...THE REASON FOR THE UPPER LEVEL LOW REMAINING STATIONARY IS A BLOCKING UPPER HIGH OVER EASTERN CANADA. THE AIRMASS WILL BE UNUSUALLY DRY FOR HEADING INTO EARLY MAY AND ALLOW FOR A LARGE DIURNAL RANGE ON LOWS AND HIGHS WITH 45-50 FOR LOWS AND HIGHS 70-75...EXCEPT SLIGHTLY WARMER OVER CENTRAL TEXAS. FLOW ALOFT OVER NORTH TEXAS DAMPENS BY NEXT WEEKEND AS THE EASTERN CANADIAN RIDGE FINALLY WEAKENS AND ALLOW THE OCCLUDED UPPER LOW TO BE OPENED UP AND CARRIED QUICKLY EAST. SOUTHERLY LOW LEVEL FLOW THEN RETURNS AND HIGHS REBOUND BACK INTO THE 80S. 05/ && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 58 84 52 75 50 / 5 5 10 10 5 WACO, TX 56 87 51 80 47 / 20 5 5 5 5 PARIS, TX 57 79 51 72 46 / 30 5 10 10 5 DENTON, TX 52 84 48 74 45 / 5 5 10 5 5 MCKINNEY, TX 53 84 49 73 46 / 20 5 10 10 5 DALLAS, TX 62 86 54 75 51 / 5 5 10 10 5 TERRELL, TX 57 83 52 75 47 / 30 5 10 10 5 CORSICANA, TX 58 86 55 78 48 / 30 5 5 10 5 TEMPLE, TX 59 88 55 79 48 / 20 5 5 5 5 MINERAL WELLS, TX 52 87 49 76 47 / 5 5 10 10 5 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
641 PM CDT SUN APR 27 2014 .DISCUSSION... 00Z TAF DISCUSSION IN AVIATION SECTION. && .AVIATION... SFC ANALYSIS HAS DRYLINE ALONG THE I-35 CORRIDOR WITH A FEW ISO STORMS WEST OF KAUS. CAP EAST OF THESE STORMS PROBABLY STRONG ENOUGH THAT THE STORMS SHOULD WEAKEN BEFORE REACHING KCLL SO WILL CONTINUE TO MONITOR. LEFT TAF VOID OF CONVECTION AS PROBABILITIES SMALL AT THIS POINT. MAIN CONCERN WILL BE LOW MVFR CIGS AHEAD OF WEAK PACIFIC FRONT. DRIER AIR SHOULD MIX INTO THE AREA BY THE MORNING HORUS AND HELP SCT OUT CIGS 12-15Z WITH MAINLY CLEAR SKIES AFTER THAT. WINDS SHOULD TURN TO THE WSW/WNW DIRECTIONS AROUND 10KTS. BOUNDARY SHOULD WORK BACK NORTH MONDAY NIGHT WITH STRONGER PACIFIC FRONT ON TUESDAY. 39 && .PREV DISCUSSION... /ISSUED 310 PM CDT SUN APR 27 2014/ DISCUSSION... VISIBLE SATELLITE SHOWS DRY LINE CLEARLY ACROSS CENTRAL TEXAS THIS AFTERNOON. THE DRY LINE IS NOW JUST AT DALLAS- FORT WORTH AND IS EXPECTED TO PUSH EAST THROUGH THE NIGHT. GLOBAL MODELS CONTINUE TO OVER DUE PRECIP ACROSS THE AREA AS THE CAP HAS REMAINED STRONG. A SPECIAL 18Z SOUNDING LAUNCH FROM TEXAS A&M SHOWS A PRETTY STOUT CAP IN PLACE AT 750 MB. CONVECTIVE TEMPERATURE FROM THIS SOUNDING IS IN THE MID 90S WHICH IS VERY UNLIKELY TO OCCUR THIS AFTERNOON. HIGH RES HRRR AND TEXAS TECH WRF STRUGGLE TO DEVELOP PRECIP THIS AFTERNOON INTO EVENING. THE HRRR AND TEXAS TECH WRF DO TRY TO DEVELOP SOMETHING IN HOUSTON COUNTY BUT QUICKLY MOVE IT OFF TO THE NORTHEAST. UPPER LEVEL DIFFLUENCE ALSO APPEARS TO BE NOW MOVING OFF TO THE NORTH AND EAST WITH THE ADVANCING UPPER LEVEL LOW. DUE TO THE MENTIONED ABOVE HAVE TRIMMED BACK POPS AND THE MENTION OF SEVERE. TOMORROW THE DRY LINE WILL STALL OUT ACROSS THE AREA GENERALLY ALONG A LINE FROM WHARTON TO HARRIS TO SAN JANCINTO COUNTY. BEHIND THE DRY LINE LIGHT WEST TO NORTHWEST WINDS AND MOSTLY CLEAR SKIES WILL ALLOW TEMPERATURES TO QUICKLY RISE. HIGHS IN THE LOWER 90S LOOKS LIKELY. NEAR THE COAST TEMPERATURES SHOULD REMAIN MORE CHECKED DUE TO ONSHORE WINDS AND HIGHER DEWPOINTS. STILL EXPECT TEMPERATURES TO REACH THE LOWER 80S. TUESDAY MORNING THE DRY LINE WILL START TO RETREAT AS THE NEXT COLD FRONT APPROACHES THE AREA. WITH LIGHT WINDS AND RISING DEWPOINTS CAN`T RULE OUT SOME PATCHY FOG TUESDAY MORNING. THE SURFACE COLD FRONT IS THEN EXPECTED TO SLOWLY PUSH THROUGH THE AREA ON TUESDAY. THE GFS REMAINS VERY QUICK WITH THE FRONT WHILE THE ECMWF... CANADIAN AND NAM 12 ARE SLOWER. HAVE LEANED TOWARDS THE EURO AS FRONTS USUALLY SLOW DOWN IN THE AFTERNOON IN COMBINATION WITH THE OCCLUDING MID- LATITUDE CYCLONE. FOR THE REST OF THE WORK WEEK BELOW NORMAL TEMPERATURES WILL BE THE STORY AS SOUTHEAST TEXAS REMAINS ON THE BACK SIDE OF THE UPPER LEVEL LOW. THURSDAY A SHORT WAVE WILL BEGIN TO DIVE SOUTHWARDS HELPING TO REINFORCE THE LONG WAVE TROUGH. THIS SHORT WAVE WILL PUSH A WEAK WIND SHIFT THROUGH THE AREA. AS THE VORT MAX MOVES SOUTHWARDS MODELS ARE GENERATING SOME QPF. MOISTURE WILL BE LIMITED BUT CAN`T RULE OUT THE CHANCE COMPLETELY. CURRENT FORECAST LOOKS ON TRACK WITH THIS. 23 MARINE... MODERATE TO STRONG ONSHORE WINDS WILL CONTINUE THROUGH TONIGHT UNDER A TIGHT PRESSURE GRADIENT. CAUTION FLAGS ARE UP FOR THE BAYS...AND ADVISORIES ARE IN EFFECT FOR THE COASTAL WATERS. WINDS AND SEAS WILL COME DOWN ON MONDAY AS THE GRADIENT WEAKENS. A STRONG COLD FRONT THAT IS EXPECTED TO BE NEAR THE COAST LATE TUESDAY AFTERNOON OR EARLY TUESDAY EVENING WILL MOVE THROUGH THE WATERS TUESDAY NIGHT. BEHIND THE FRONT... CAUTION FLAGS ARE LIKELY AND ADVISORIES MIGHT BE NEEDED FOR STRENGTHENING NORTH WINDS AND BUILDING SEAS. 42 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 65 91 62 82 51 / 10 10 10 10 10 HOUSTON (IAH) 72 91 68 86 55 / 20 20 10 10 10 GALVESTON (GLS) 73 82 72 82 62 / 20 10 10 20 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: BRAZORIA...CHAMBERS...FORT BEND...GALVESTON... HARRIS...JACKSON...LIBERTY...MATAGORDA...WHARTON. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 AM CDT MONDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. SMALL CRAFT ADVISORY UNTIL 4 AM CDT MONDAY FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...40 AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
415 PM CDT SAT APR 26 2014 .SHORT TERM... (Tonight and Sunday) Conditionally severe thunderstorm threat tonight, mainly in the Big Country and Concho Valley. West Central Texas is certainly unstable with RUC SB CAPES up to 3000 J/KG, but warm air aloft may prevent storms from occurring. Surface Observations show only weak low level convergence along the dryline. Some virga indicated in the Big Country from Abilene to west of Wichita Falls, but the mid level instability associated with it appears to be fairly high, above 10000 FT AGL. Both the GFS and the HRRR models develop isolated storms in the Big Country this evening, with the GFS the only one to develop storms later tonight, as a Pacific front catches up with dryline towards midnight. Region should become more unstable as cooler air aloft moves in as an upper trough approaches. There will also be stronger low level convergence, with west winds behind the Pacific front. But storm development is still conditional. Strong downslope west warming winds expected Sunday behind the Pacific Front. Should see Wind Advisory criteria of 25 to 35 mph, with gusts to 45 mph by midmorning. Have a Red Flag Warning for dangerous fire conditions from 11 AM to 10 PM. .FIRE WEATHER... A Red Flag Warning for fire weather is in effect for West Central Texas from 11 AM to 10 PM. Dangerous fire weather conditions Sunday as the dryline and Pacific front sweep through, bringing dry and windy west winds Minimum RH values will fall near 10 percent with 20 foot west winds of 20 to 30 mph gusting to 35 mph. Added Mason and San Saba counties to the Red Flag Warning as 20 foot winds will be close to 20 mph. Elevated fire weather conditions are also expected Monday due to gusty west winds and very dry conditions. .LONG TERM... (Sunday night through next Saturday) Warm and dry weather will prevail on Monday, with cooler temperatures Tuesday through next Friday. The large closed upper low will be centered over the Central Plains late this weekend, and will move slowly northeast to the Great Lakes region by mid week. Associated surface low currently over eastern Colorado this evening, will move northeast into eastern Nebraska Sunday evening. Monday will be another warm day with gusty west winds once again with afternoon highs in the mid and upper 80s. A cold front will move across the area Monday night, bringing much cooler temperatures for Tuesday, with highs mainly in the 70s. Northwest flow aloft will prevail across the area Tuesday through much of next week. A persistent surface ridge will remain in place and will result in unseasonably cool temperatures for West Central Texas through Friday. High temperatures through Friday will be mainly in the 70s, with overnight lows in the 40s and 50s. Warmer weather is expected next weekend with near seasonal temperatures. No rain is forecast through the period. && .PRELIMINARY POINT TEMPS/POPS... Abilene 92 63 88 51 83 / 20 40 0 0 0 San Angelo 94 63 90 51 88 / 10 30 0 0 0 Junction 90 66 92 50 90 / 10 30 5 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING from 11 AM to 10 PM CDT Sunday FOR THE FOLLOWING ZONES: Brown...Callahan...Coke...Coleman...Concho... Crockett...Fisher...Haskell...Irion...Jones...Kimble...Mason... McCulloch...Menard...Nolan...Runnels...San Saba...Schleicher... Shackelford...Sterling...Sutton...Taylor...Throckmorton...Tom Green. WIND ADVISORY from 10 AM to 7 PM CDT Sunday FOR THE FOLLOWING ZONES: Callahan...Coke...Coleman...Concho...Crockett...Fisher... Haskell...Irion...Jones...Nolan...Runnels...Schleicher... Shackelford...Sterling...Taylor...Throckmorton...Tom Green. && $$ 04/24
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
100 AM CDT SAT APR 26 2014 .DISCUSSION...SEE AVIATION BELOW FOR 06Z TAF UPDATE. && .AVIATION...MVFR TO IFR CEILINGS ONCE AGAIN FILLING IN ACROSS THE REGION TONIGHT. EXPECT LOW CLOUD DECK TO REMAIN OVER THE REGION OVERNIGHT AND INTO THE MID MORNING. LIGHT PATCHY FOG WILL ALSO SLIGHTLY IMPACT VISIBILITIES ACROSS THE REGION...BUT WITH WINDS OVERNIGHT REMAINING MORE ELEVATED THAN YESTERDAY...NOT EXPECTING FOG TO BECOME DENSE. LOWEST VSBYS WILL OCCUR AOA KVCT...TEMPORARILY DROPPING TO IFR CRITERIA IN THE EARLY MORNING THROUGH SUNRISE. EXPECT INCREASED SOUTH TO SOUTHEAST WINDS DURING THE DAY SATURDAY. DURING THE EARLY AFTERNOON CEILINGS WILL LIFT AND DISSIPATE ENOUGH FOR VFR CRITERIA AT KVCT...KALI...AND KLRD. MVFR CEILINGS WILL LINGER OVER KCRP DURING THE AFTERNOON HOWEVER. SIMILAR CONDITIONS WILL BE LIKELY DURING THE LATE OVERNIGHT HOURS THEN ONCE AGAIN. && .PREV DISCUSSION... /ISSUED 730 PM CDT FRI APR 25 2014/ DISCUSSION...THE PAST SEVERAL RUNS OF THE HRRR HAVE CONTINUED TO INDICATE THAT SOME OF THE ONGOING SIERRA MADRE CONVECTION MAY AFFECT WESTERN PORTIONS OF WEBB COUNTY LATER THIS EVENING BEFORE EVENTUALLY DISSIPATING IN AN INCREASINGLY CAPPED ENVIRONMENT. CURRENT RADAR TRENDS LEAD CREDENCE TO THE HRRR. WL THUS INTRODUCE SLIGHT CHC POPS FOR WESTERN WEBB COUNTY FOR THIS EVENING. OTHERWISE...MOSTLY MINOR CHANGES WERE MADE FOR THIS EVENING PACKAGE BASED UPON CURRENT AND EXPECTED TRENDS. MORE WIND TNT WL KEEP FOG FROM GETTING TOO WIDESPREAD AND TOO LOW VSBY-WISE. MARINE...THE OVERALL GRADIENT HAS INCREASED FROM 24 HOURS AGO BUT IS STILL EXPECTED TO REMAIN BELOW SCA THRESHOLDS FOR TNT. DID LOWER THE WAVEHEIGHTS BY AROUND 1 FOOT FROM THE PREVIOUS PACKAGE FOR TONIGHT AND SATURDAY. AN INCREASING GRADIENT/LLJ IN RESPONSE TO AN APPROACHING STRONG S/WV CURRENTLY MOVING THROUGH CALIFORNIA WL PRODUCE SCA CONDITIONS FOR THE SRN BAYS SATURDAY AFTN AND MOST AREAS SAT NIGHT INTO SUNDAY. PREV DISCUSSION... /ISSUED 632 PM CDT FRI APR 25 2014/ DISCUSSION...SEE AVIATION SECTION FOR 00Z TAFS. AVIATION...OTHER THAN SOME SPOTTY MVFR CEILINGS NEAR THE COAST...VFR CONDITIONS WILL CONTINUE OVER THE REGION DURING THE EARLY EVENING HOURS. EXPECT STRATUS/MVFR CEILINGS AROUND 1500 FEET TO DEVELOP OVER THE COASTAL PLAINS 03-04Z. CEILINGS ARE EXPECTED TO LOWER TO IFR FROM 06-07Z WITH MVFR VSBYS WITH FOG OVER COASTAL SITES. OCCASIONAL IFR VSBYS WILL BE POSSIBLE OVER THE VICTORIA CROSSROADS BEFORE SUNRISE. MVFR CIGS WILL SPREAD WEST INTO LAREDO AREA BY 08Z AND PERSIST UNTIL 16Z SATURDAY. WILL CONTINUE TO MONITOR ISOLATED CONVECTION THAT DEVELOPED OVER THE HIGHER TERRAIN IN NORTHEAST MEXICO AHEAD OF A WEAK UPPER LEVEL DISTURBANCE. ADVECTION OF DRIER AIR IN THE LOWER LEVELS SHOULD INHIBIT ACTIVITY FROM REACHING THE RIO GRANDE LATER THIS EVENING. MVFR CIGS WILL PERSIST THROUGH THE MORNING WITH CLOUDS SCATTERING OUT FOR MOST OF THE REGION EXCEPT FOR THE COASTAL BEND WHERE MVFR CIGS MAY PERSIST THROUGH THE AFTERNOON. PREV DISCUSSION... /ISSUED 323 PM CDT FRI APR 25 2014/ SHORT TERM...25 TO 30 KT LLJ EXPECTED TO DEVELOP TONIGHT IN RESPONSE TO A DEEPENING LOW PRESSURE SYSTEM OVER THE HIGH PLAINS. THIS...IN COMBINATION WITH AMPLE MOISTURE TO AID IN NOCTURNAL STRATUS DEVELOPMENT...SHOULD PREVENT MUCH IN THE WAY OF FOG DEVELOPMENT TONIGHT...THOUGH WIDESPREAD LOW STRATUS IS LIKELY. AFTER THE CLOUD DECK BURNS OFF...TOMORROW WILL SEE TEMPS ABOVE AVERAGE...BECOMING DOWNRIGHT TOASTY OVER THE WESTERN BRUSH COUNTRY AS A DRYLINE CROSSES THE RIO GRANDE IN THE AFTERNOON WITH NEAR TRIPLE DIGIT HIGHS. BY LATE AFTERNOON...UPPER LEVEL DIFLUENCE FROM THE PHASING OF THE POLAR AND SUBTROPICAL JETS WILL BEGIN TO AFFECT THE REGION. 30-40 KT 0-6 KM BULK SHEAR...2000-3000 J/KG OF MLCAPE...AND MODERATE HELICITY VALUES MAY ALLOW FOR SOME STRONG THUNDERSTORMS TO DEVELOP...PARTICULARLY DEVELOPING OFF OF THE SIERRA MADRE AND CROSSING THE RIO GRANDE. THE STORM ENVIRONMENT LOOKS TO BE SLIGHTLY LESS FAVORABLE NEAR THE COAST...BUT HAVE STILL INCLUDED MUCH OF THE AREA WITH 20 POPS. THE ENVIRONMENT WILL REMAIN FAVORABLE OVERNIGHT. LONG TERM (SUNDAY THROUGH FRIDAY)...PERIOD COULD BEGIN ACTIVE WITH THUNDERSTORMS /POSSIBLY MCS/ MOVING EASTWARD THROUGH THE CWA AS THETA E RIDGE PROGRESSES EASTWARD. MOST OF THE AREA SHOULD BE CAPPED WITH 850 TEMPS 20 DEGREES OR HIGHER...BUT IF CONVECTION DEVELOPS IT MAY SUSTAIN ITSELF INTO NORTHEASTERN PARTS OF CWA. DRYLINE MOVES THROUGH MUCH OF THE AREA ON SUNDAY WITH TEMPERATURES VERY WARM...INTO THE 90S FOR MOST OF THE AREA...WITH ABOVE 100 DEGREES POSSIBLE ALONG THE RIO GRANDE. THIS IS DEPENDENT THOUGH ON ANY LINGERING MID/HIGH CLOUD THAT COULD BE LEFTOVER FROM POTENTIAL MCS SATURDAY NIGHT/SUNDAY. MONDAY HAS SIMILAR SETUP...BUT WITHOUT THE CAVEAT OF MID/HIGH CLOUDS. SHOULD SEE HOT TEMPERATURES BEHIND DRYLINE THAT WILL MOVE THROUGH MOST OF THE AREA. TRICKY TEMPERATURES FOR TUESDAY WITH COLD FRONT TIMING AROUND NOON. WILL SEE SOME /THOUGH NOT SIGNIFICANT/ COLD ADVECTION BEHIND THE FRONT...SO THINK TEMPS SHOULD BE SEVERAL DEGREES COOLER THAN MONDAY...THOUGH STILL IN THE 90S UNLESS TIMING SPEEDS UP. MOISTURE POOLING ALONG AND OFF THE COAST WILL PRODUCE A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS MAINLY IN OFFSHORE AREAS TUESDAY WITH THE FRONT. COLD FRONT SHOULD KNOCK TEMPERATURES BACK INTO THE 80S FOR THE FOLLOWING FEW DAYS WITH MUCH DRIER CONDITIONS AS DPTS DROP TO MUCH MORE PLEASANT LEVELS /40S AND 50S/. ONSHORE FLOW REDEVELOPS LATE THURSDAY AND WILL BRING A GRADUAL INCREASE IN MOISTURE FOR FRIDAY. MODELS NOT IN GOOD AGREEMENT FOR FRIDAY...BUT MODELS HINTING AT ANOTHER UPPER TROUGH FOR FRIDAY INTO THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 88 73 94 71 92 / 10 20 20 10 10 VICTORIA 87 71 88 69 92 / 10 20 30 10 10 LAREDO 99 73 101 71 99 / 20 30 10 10 10 ALICE 93 73 97 70 96 / 10 30 20 10 10 ROCKPORT 81 71 82 72 85 / 10 20 30 10 10 COTULLA 95 71 98 68 97 / 20 30 10 10 10 KINGSVILLE 91 73 96 71 95 / 10 20 20 10 10 NAVY CORPUS 83 73 83 72 82 / 10 20 20 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ LK/84...AVIATION
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1139 PM CDT FRI APR 25 2014 .AVIATION... SURFACE DEWPOINTS ARE NOW IN THE LOW 60S ACROSS CENTRAL AND SOUTHEAST TEXAS AND MOISTURE WILL CONTINUE TO SURGE NORTHWARD THROUGH THE TAF SITES DURING THE NEXT FEW HOURS. SURFACE TEMPS SHOULD BE WARM ENOUGH TO LIMIT ANY ADVECTION FOG...BUT LOW STRATUS APPEARS LIKELY FOR KACT AFTER 10Z. MVFR/IFR STRATUS IS NOW BEGINNING TO FORM ACROSS THE TEXAS COASTAL PLAINS...AND WACO MAY CONTEND WITH MVFR OR PERHAPS BRIEF IFR STRATUS AROUND AND SHORTLY AFTER DAYBREAK. STRATUS MAY STRUGGLE TO REACH AS FAR NORTH AS THE METROPLEX...BUT WILL SHOW TEMPO MVFR CIGS FROM 12-14Z FOR DFW/DAL/GKY WHERE SOME OF THE HIGH RES GUIDANCE AND THE RUC/NAM INDICATE LOW LEVEL SATURATION OCCURRING. ANY STRATUS SHOULD LIFT/SCATTER FAIRLY QUICKLY BY MID MORNING. ASIDE FROM MID-HIGH CLOUDS JUST SOME FAIR WEATHER CUMULUS EXPECTED SATURDAY AFTERNOON AND EVENING WITH SOUTH WINDS INCREASING TO NEAR 20KT AND GUSTY. MVFR STRATUS WILL LIKELY RETURN AROUND MIDNIGHT SATURDAY NIGHT TO THE TAF SITES. THUNDERSTORMS SHOULD REMAIN WELL WEST AND NORTHWEST OF THE TAF SITES TOMORROW EVENING. HOWEVER...ELEVATED CONVECTION WILL LIKELY BEGIN TO AFFECT THE TAF SITES BY 9Z AND HAVE INDICATED A VCTS TO COVER THIS THREAT. MODELS CONTINUE TO INDICATE DRYLINE/PACIFIC FRONT WILL MOVE EAST OF TAF SITES BY SUNDAY AFTERNOON BEFORE NEXT ROUND OF SEVERE CONVECTION FIRES...BUT STILL NEED TO MONITOR THIS POTENTIAL. TR.92 && .UPDATE... QUICK UPDATE TO THE FORECAST TO ADD A LITTLE MORE CLOUD COVER EARLY SATURDAY MORNING...MAINLY TO THE SOUTHERN HALF OF THE CWA AS STRONG MOISTURE RETURN CONTINUES. A LOOK AT THE LATEST NAM GUIDANCE CONTINUES TO SHOW SEVERE CONVECTIVE POTENTIAL TOMORROW AFTERNOON/EVENING ACROSS WEST CENTRAL TEXAS. NO CHANGES MADE TO THE CURRENT CONVECTIVE FORECAST FOR TOMORROW INTO TOMORROW NIGHT. THE RAP DOES SHOW SOME WEAKENING OF THE CAP EARLIER IN THE AFTERNOON OUT WEST WHICH COULD LEAD TO A SLIGHTLY EARLIER INITIATION TIME BUT OTHERWISE THE GENERAL THINKING IS UNCHANGED. FOR SUNDAY...MODEL GUIDANCE IS IN GOOD AGREEMENT WITH MOVING THE DRYLINE/FRONT EAST INTO SUNDAY MORNING...ACTUALLY BEHAVING MORE LIKE A FRONT WITH COOLING TEMPERATURES BEHIND IT AT 850MB. IT IS APPEARING MORE LIKELY THAT THIS FEATURE WILL BE ALONG OR EAST OF I-35 BEFORE SURFACE BASED CONVECTION CAN DEVELOP ON SUNDAY. THE HIGHEST THREAT FOR SEVERE WEATHER ON SUNDAY WILL BE ACROSS THE EASTERN COUNTIES INTO THE ARKLATEX. SOME ELEVATED CONVECTION IS EXPECTED TO BE ONGOING EARLY SUNDAY MORNING AND THIS COULD QUICKLY BECOME SURFACE BASED BY EARLY AFTERNOON GENERALLY EAST OF I-35. CURRENT FORECAST HANDLES THIS WELL AND NO CHANGES ARE NEEDED AT THIS TIME. DUNN && .SHORT TERM/THOUGH MONDAY/... A STRONG UPPER LOW CONTINUES MOVING INLAND OVER THE WESTERN STATES WITH A SHORTWAVE RIDGE ACROSS NORTH AND CENTRAL TEXAS LINGERING THROUGH TONIGHT. THIS SYSTEM IS A WAYS OFF WITH A SUBSTANTIAL CAP THAT SHOULD KEEP THE WEATHER DRY TONIGHT AND THROUGH THE DAY SATURDAY. BREEZY SOUTH WINDS AND RAPIDLY INCREASING DEW POINTS FROM THE TEXAS COASTAL AREAS ARE EXPECTED TO HOLD LOWS TONIGHT BETWEEN 55 AND 66 DEGREES WITH HIGHS WARMING WELL INTO THE 80S SATURDAY AND EVEN THE LOWER 90S ACROSS THE WEST. IF YOU WANT TO ENJOY PART OF THE WEEKEND AND BE OUTDOORS...SATURDAY IS YOUR BEST BET. SATURDAY NIGHT THROUGH SUNDAY EVENING IS EXPECTED TO BE AN ACTIVE PERIOD WEATHER-WISE...AS LEAD SHORTWAVE ENERGY BEGINS NEGATIVELY ROTATING THROUGH THE FOUR CORNERS AND OVER THE WESTERN HIGH PLAINS BY SUNRISE SUNDAY. RAPID HEIGHT FALLS MOVING OUT OF THE ROCKIES WILL HELP DEEPEN A SURFACE DRYLINE ACROSS THE SOUTH PLAINS AND TEXAS PANHANDLE THROUGH SATURDAY EVENING. IT WILL LIKELY TAKE UNTIL LATE AFTERNOON OR NEAR 00Z BEFORE A FEW DISCRETE STORMS INITIATE FROM NORTHWEST OF ABILENE AND UP THROUGH CHILDRESS AND SOUTHWEST OKLAHOMA...VERY FAST SSW FLOW STEERING THE MAJORITY OF ACTIVITY TO THE NORTHEAST. THE DRYLINE SHOULD BEGIN TRANSVERSING EAST THROUGH THE EVENING HOURS WITH ISOLATED TO SCATTERED STORMS POSSIBLY ENTERING OUR FAR W/NW COUNTIES BEFORE MIDNIGHT. IN ADDITION...SURFACE-BASED STORMS WILL REMAIN POSSIBLE MOST OF THE EVENING WITH ALL MODES OF SEVERE WEATHER POSSIBLE WITH ANY SUPERCELLS BEFORE AN INCREASING LLJ OVERNIGHT AND WAA HELP RE- INTENSIFY THE CAPPING INVERSION WITH CONVECTION EXPECTED TO BE ELEVATED OVERNIGHT AND THROUGH THE SUNRISE HOURS SUNDAY. STORM CHANCES SHOULD BE HIGHEST ACROSS THE NORTHERN COUNTIES WHERE BULK OF FORCING FROM ENHANCED ELEVATED WAA AND FASTER EASTWARD PROGRESSION OF THE SURFACE DRYLINE WILL OCCUR. DESPITE THE ELEVATED NATURE OF STORMS...VERY STEEP LAPSE RATES BETWEEN 850-650MB WILL ALLOW FOR PLENTY OF MUCAPE IN THE HAIL GROWTH ZONE. HAVE LEFT SEVERE MENTION IN FOR THE OVERNIGHT PERIOD FOR THE POTENTIAL OF SOME LARGER HAIL. THE CHALLENGES CONTINUE AS WE MOVE THROUGH THE DAY SUNDAY AS THE STRONG SHORTWAVE TROUGH CONTINUES TO NEGATIVELY TILT OVER CENTRAL HIGH PLAINS. THE STRONG WEST- SOUTHWEST COMPONENT ATOP THE APPROACHING SURFACE DRYLINE WILL HELP MOVE IT EAST FASTER ACROSS NORTH TEXAS VERSUS FURTHER SOUTH OVER OUR CENTRAL TEXAS COUNTIES THROUGH EARLY AFTERNOON. MODELS STILL SHOW A VARIANCE OF THE DRYLINE POSITION SUNDAY AFTERNOON WITH AS FAR WEST AS I-35/35E...TO AS FAR EAST AS I-45 UP THROUGH I-30. WITH THIS IN MIND...HAVE ORIENTED POPS NE-SW ALONG THE DRYLINE WITH HIGHEST CHANCES FOR SEVERE SUPERCELL STORMS OCCURRING MAINLY EAST OF A BONHAM-TERRELL-HEARNE LINE. THE VERY WARM TEMPERATURES AND HIGH DEW PTS PRODUCING SBCAPE VALUES OF 2500-3500 J/KG EAST OF THE DRYLINE AND WESTERLY EFFECTIVE SHEAR VALUES 30-35 KTS WITH SOUTHERLY 0-1KM SHEAR 20 KTS+...SURFACE- BASED STORMS SHOULD ALLOW FOR ALL POSSIBLE MODES OF SEVERE WEATHER INCLUDING A FEW TORNADOES. THE WINDOW FOR SEVERE WEATHER LOOKS TO BE EARLY AFTERNOON THROUGH EARLY EVENING...WHEN BETTER FORCING BOTH SURFACE AND ALOFT SHOULD SHIFT EAST OUT OF THE AREA TOWARD THE MODERATE RISK AREA ACROSS THE ARKLATEX. WINDY AND WARM CONDITIONS WILL LIKELY RAMP UP THE FIRE DANGER ACROSS THE WESTERN TWO THIRDS OF THE AREA WITH MINIMUM HUMIDITY VALUES FALLING BELOW 20 PERCENT. GREEN UP OF GRASSES AND LIGHTER WINDS ON SUNDAY SHOULD KEEP THE FIRE DANGER ONLY AT ELEVATED LEVELS. WE MAY HAVE TO WATCH FOR HIGH TO CRITICAL FIRE WEATHER CONDITIONS FOR MONDAY AFTERNOON WITH MORE GUSTIER WEST WINDS. && .LONG TERM/MON NIGHT AND BEYOND/... THE FIRST OF A COUPLE OF LATE SEASON COLD FRONTS ARRIVES MONDAY NIGHT WITH SLIGHTLY COOLER TEMPERATURES ON TUESDAY. IT APPEARS IT WILL BE A RELATIVELY BENIGN WEEK FOR THE SOUTHERN PLAINS WITH THE UPPER LOW OVER THE PLAINS BEING HELD UP BY SEMI OMEGA BLOCKING UPPER HIGH OVER EASTERN CANADA. THE UPPER LOW WILL ONLY MIGRATE SLOWLY NORTHEAST TOWARD THE GREAT LAKES THROUGH THE END OF THE WEEK. THIS SHOULD ALLOW FOR PERIODIC FRONTAL PASSAGES AND KEEP A NORTH COMPONENT TO THE WIND AND A DRY AIRMASS IN PLACE THROUGH MUCH OF THE WEEK AND KEEP TEMPERATURES 5-10 DEGREES BELOW NORMALS. IT APPEARS MOISTURE WILL BE TOO SHALLOW AND SCANT WITH A STRONG SHORTWAVE ROTATING ACROSS TEXAS THURSDAY INTO FRIDAY AND HAVE LEFT A DRY FORECAST FOR NOW ALL THE WAY INTO NEXT WEEKEND. 05/ && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 61 86 69 90 61 / 0 5 40 40 5 WACO, TX 62 85 68 90 55 / 0 5 20 30 5 PARIS, TX 54 85 67 80 56 / 0 5 40 70 30 DENTON, TX 60 85 68 87 55 / 5 5 60 40 5 MCKINNEY, TX 58 85 68 87 56 / 0 5 50 50 10 DALLAS, TX 61 87 69 90 62 / 0 5 40 50 5 TERRELL, TX 58 85 68 84 54 / 0 5 30 50 10 CORSICANA, TX 60 84 68 85 57 / 0 5 20 50 10 TEMPLE, TX 63 86 69 89 57 / 0 10 20 30 5 MINERAL WELLS, TX 61 88 69 88 55 / 5 10 50 20 5 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1041 PM CDT SUN APR 27 2014 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND MONDAY ISSUED AT 238 PM CDT SUN APR 27 2014 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW OCCLUDED LOW PRESSURE SPINNING OVER WESTERN KANSAS. A WARM FRONT EXTENDS FROM THIS LOW EASTWARD INTO THE OHIO VALLEY. NORTH OF THIS WARM FRONT...MID-LEVEL THETAE ADVECTION AND FGEN IS CONTRIBUTING TO A BAND OF LIGHT RAIN PROGRESSING NORTHWARD ACROSS THE FORECAST AREA THIS AFTERNOON. SHOWERS ARE TRYING TO REDEVELOP SOUTH OF THIS RAIN BAND OVER SOUTHWEST WISCONSIN...BUT COVERAGE IS SIGNIFICANTLY LESS OVER EASTERN IOWA AND NORTHERN ILLINOIS. THEN A POTENT LINE OF STORMS IS PROGRESSING NORTHEAST ACROSS IOWA AND MISSOURI. RAIN CHANCES AND AMOUNTS ARE THE MAIN FORECAST CONCERN IN THE SHORT TERM. TONIGHT...THE OCCLUDED CYCLONE OVER THE CENTRAL PLAINS WILL MOVE VERY LITTLE TO THE NORTHEAST FROM CENTRAL KANSAS TO NORTHEAST NEBRASKA WHILE HUDSON BAY HIGH PRESSURE REMAINS IN PLACE. ANTICIPATING THAT ARCING BAND OF RAIN ASSOCIATED WITH MID-LEVEL MOISTURE ADVECTION AND FGEN WILL HAVE WEAKENED AT THE START OF THE EVENING AS IT MOVES INTO A DRIER AIRMASS...BUT COULD STILL BE SOME SHOWERS HANGING ON ACROSS NORTHERN WISCONSIN AND WILL LEAVE A CHANCE IN THE FORECAST. THEN ANTICIPATE THAT THERE WILL BE A BREAK OR REDUCED COVERAGE OF PRECIP FOR A PERIOD THIS EVENING BEFORE THE LINE OF CONVECTION OVER THE PLAINS PIVOTS AS IT MOVES NE INTO WISCONSIN. THINK THIS LINE WILL MAKE IT INTO CENTRAL WISCONSIN AND THE SOUTHERN FOX VALLEY LATE TONIGHT (THOUGH WILL NOT BE NEARLY AS INTENSE AS IT STANDS CURRENTLY) DUE TO INCREASING 900-800MB MOISTURE TRANSPORT AND FGEN. PRIOR TO THIS AREA OF RAIN ARRIVING...CANNOT RULE OUT SPOTTY TO SCATTERED SHOWERS REDEVELOPING. BUT IN GENERAL...WILL HAVE THE LOWEST CHANCE OF PRECIP EARLY IN THE EVENING AND THEN GRADUALLY INCREASE CHANCES THROUGH THE NIGHT. LOWS SHOULD BE RELATIVELY STEADY IN THE MIDDLE TO UPPER 30S. MONDAY...THE ARCING BAND OF RAIN WILL SLOWLY LIFT NORTHEAST THROUGH THE DAY BUT SHOULD BE GRADUALLY WEAKENING AS IT DOES SO. SOME CONCERN THAT THE RAINS COULD BRING DOWN SOME BEEFY GUSTS FROM ALOFT AS THE NAM IS DEPICTING WINDS UPWARDS OF 60 KTS ABOUT 2KFT ABOVE THE SURFACE OVER CENTRAL WISCONSIN. WILL MENTION HIGHER GUSTS IN THE HWO. DESPITE MID-LEVEL HEIGHT FALLS...INSTABILITY APPEARS TOO MARGINAL FOR MUCH OF A THUNDER CHANCE. BUT WITH PWATS OVER AN INCH AND THE SLOWLY FORWARD PROGRESSION...DECENT RAINS ARE LIKELY OVER CENTRAL AND EAST-CENTRAL WISCONSIN OF A HALF INCH TO AN INCH. NORTHERN AND NE WISCONSIN WILL BE RELATIVELY DRIER DUE TO THE DRY NE LOW LEVEL FLOW BUT THAT AREA SHOULD SEE RAIN TOO. HIGHS ONLY IN THE LOW TO MIDDLE 40S. .LONG TERM...MONDAY NIGHT THROUGH SUNDAY ISSUED AT 238 PM CDT SUN APR 27 2014 PCPN TRENDS THROUGHOUT THE PERIOD...AND STRONG E-NE WINDS MONDAY NIGHT INTO TUESDAY MORNING...ARE THE MAIN FCST CONCERNS. AN UPPER LEVEL LOW WILL MOVE TOWARD THE UPPER MISSISSIPPI VALLEY ON MONDAY NIGHT...REMAIN OVER THE WESTERN GREAT LAKES FROM TUESDAY THROUGH THURSDAY...THEN WEAKEN AND GRADUALLY SHIFT NE ON THURSDAY NIGHT AND FRIDAY. ALTHOUGH PCPN WILL BE IN THE FCST THROUGHOUT THE PERIOD...THE BEST RAINFALL SHOULD OCCUR AS A STRONG S/W TROF ROTATES THROUGH LATE MONDAY NIGHT INTO TUESDAY MORNING...AND AS ANOTHER WAVE OR WEAK UPPER LOW AFFECTS NE/N WI LATE TUESDAY NIGHT INTO WEDNESDAY. PCPN SHOULD BECOME MORE SCATTERED IN NATURE DURING THE LATTER HALF OF THE WEEK. MOST OF THE PCPN SHOULD FALL AS RAIN... ALTHOUGH A MIX OF RAIN/SNOW IS POSSIBLE OVER PARTS OF NC/FAR NE WI LATE MON NGT/EARLY TUE...AND AGAIN LATE WED NGT/EARLY THU AND LATE THU NGT/EARLY FRI. SIGNIFICANT RAINFALL AMOUNTS MAY CAUSE SOME MINOR RIVER FLOODING DURING THE UPCOMING WORK WEEK. A STRONG PRESSURE GRADIENT WILL SET UP BETWEEN A LARGE HUDSON BAY HIGH AND LOW PRESSURE APPROACHING FROM THE CENTRAL PLAINS ON MON NGT. WITH ENE WINDS OF 35-50 KTS ABOUT A THOUSAND FEET OFF THE SFC...STRONG GUSTS OF 30 TO 40 MPH MAY OCCUR IN THE FAVORED LOCATIONS...MAINLY CENTRAL WI AND THE FOX VALLEY. THE WINDS ARE EXPECTED TO DECREASE AS AN INVERTED SFC TROF ARRIVES AND THE GRADIENT WEAKENS TUESDAY AFTERNOON. THE MAIN WEATHER FEATURE FOR NEXT WEEKEND IS A COLD FRONT THAT IS PROGGED TO MOVE THROUGH THE REGION ON SUNDAY. THIS LOOKS LIKE A FAIRLY DYNAMIC SYSTEM...SO POPS MAY NEED TO BE INCREASED WITH SUBSEQUENT FCSTS. TEMPERATURES WILL REMAIN WELL BELOW NORMAL...WITH HIGHS IN THE 40S AND LOWER 50S THROUGH MOST OF THE PERIOD. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1041 PM CDT SUN APR 27 2014 A LARGE UPPER LOW SYSTEM SLOWLY CHURNING ACROSS MID SECTION OF THE COUNTRY THIS WEEK WILL CONTINUE TO LIFT BANDS OF SHOWERS NORTH OVER THE STATE FOR MUCH OF THE WEEK. DRY AIR ON EASTERLY WINDS WILL CONTINUE TO POUR INTO THE AREA TO KEEP CIGS MAINLY AT VFR LEVELS FOR MOST OF TONIGHT INTO MONDAY. AS SHOWERS BECOME MORE WIDESPREAD FROM SOUTHWEST TO NORTHEAST MONDAY...CIGS WILL ALSO LOWER TO MVFR LEVELS FROM SOUTHWEST TO NORTHEAST. COMPACT PRESSURE GRADIENT AHEAD OF THE LARGE SURFACE LOW OVER THE CENTRAL PLAINS WILL ENSURE GUSTY WINDS AT THE SURFACE FOR A FEW DAYS ALONG WITH LLWS CONDITIONS DUE TO 2000 FOOT WINDS WINDS UP TO 50 KTS THROUGH MONDAY. && .HYDROLOGY... ISSUED AT 238 PM CDT SUN APR 27 2014 RAINFALL TOTALS OF 1.5 INCHES OVER FAR NORTHERN WI...AND 1.5 TO 2.5 INCHES OVER THE SRN THREE-QUARTERS OF THE FCST AREA...ARE EXPECTED DURING THE SUNDAY NGT THROUGH WEDNESDAY NGT PERIOD. THE RESULTING RUNOFF COULD CAUSE SOME MINOR RIVER FLOODING...AS SEVERAL RIVERS STILL REMAIN ABOVE BANKFULL. WILL CONTINUE TO MENTION THE RIVER FLOODING THREAT IN A HYDROLOGIC OUTLOOK AND THE HAZARDOUS WEATHER OUTLOOK. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KIECKBUSCH AVIATION.......TDH HYDROLOGY......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
830 PM CDT SUN APR 27 2014 .UPDATE... THINGS HAVE QUIETED DOWN ACROSS THE AREA THIS EVENING...NOT THAT IT EVER REALLY GOT LOUD. THE BIG STORMS TO OUR SOUTHWEST LATE THIS AFTERNOON JUST COULDN/T SURVIVE UP IN THESE PARTS WITH A BOUNDARY LAYER TEMP SITTING IN THE 40S WITH DEWPOINTS IN THE 30S. ALTHOUGH THE BOUNDARY LAYER IS STABLE...JUST ABOVE IT THERE IS AMPLE MOISTURE AND SOME HEAT RETURNING AS THE WARM CONVEYOR BELT LIFTS UP THIS WAY. IT WILL BE WET ON AND OFF THROUGH THE NIGHT WITH A FEW RUMBLES OF THUNDER POSSIBLE. THE MAIN MOISTURE AXIS SHOULD LIFT UP HERE AFTER ABOUT 3-4AM WITH DECENT RAINFALL EXPECTED DURING MONDAY MORNING. THIS IS JUST THE FIRST OF A FEW WAVES OF RAINFALL OVER THE NEXT COUPLE OF DAYS. && .AVIATION/06Z TAFS/... LOOK FOR CONDITIONS TO STEADILY DETERIORATE OVERNIGHT AS PERSISTENT RAIN FINALLY SATURATES UP THE BOUNDARY LAYER AND WE EVENTUALLY GET INTO MVFR/IFR CIGS/VSBYS LATER TONIGHT AND THROUGH THE REMAINDER OF THE TAF PERIOD. THE EASTERLY WINDS HAVE DIMINISHED SOME DUE TO THE COLD BOUNDARY LAYER WHICH IS RAISING CONCERN FOR LOW LEVEL WIND SHEAR. WILL INTRODUCE IT INTO THE TAFS FOR THE INTIAL HOURS...UNTIL WE MIX OUT TOMORROW MORNING. WINDS AT JUST 2KFT ARE BLOWING 50KTS WHILE AT THE SURFACE THEY ARE AROUND 15KTS. && .PREV DISCUSSION... /ISSUED 336 PM CDT SUN APR 27 2014/ SHORT TERM... TONIGHT AND MONDAY...FORECAST CONFIDENCE IS HIGH. SCATTERED SHOWERS CONTINUE TO DEVELOP ACROSS WESTERN PORTIONS OF THE AREA...WITH MORE SHOWERS AND STORMS DEVELOPING INTO WEST CENTRAL TO NORTH CENTRAL ILLINOIS. THESE CONTINUE TO DEVELOP ON THE 850 MB LOW LEVEL JET AND FOCUSED LOW LEVEL WARM AIR ADVECTION. ADDED POPS THROUGH THE REST OF THE AFTERNOON TO ACCOUNT FOR THE CURRENT SHOWERS OVER THE WESTERN COUNTIES. THE ACTIVITY TO OUR SOUTH MAY MOVE INTO THE SOUTHERN PORTIONS OF THE AREA BY 00Z MONDAY PER HRRR AND 4KM WRF/NMM MODELS. ELEVATED CAPES ARE A FEW HUNDRED J/KG...SO COULD HEAR CLAPS OF THUNDER AS WELL. THUS...KEPT THE POPS GOING INTO THE EARLY EVENING IN THE WEST AND SOUTHWEST COUNTIES. MAY HAVE TO GO HIGHER WITH POPS IF THIS ACTIVITY REMAINS ORGANIZED. HRRR AND 4KM WRF/NMM MODELS BRINGING MAIN WARM CONVEYOR BELT RAIN INTO THE AREA AT SLIGHTLY DIFFERENT TIMES...THE HRRR NOT UNTIL AFTER MIDNIGHT AND THE WRF/NMM AFTER 03Z MONDAY. USED THE 4KM WRF/NMM FOR TIMING...AS IT SEEMS TO HAVE A DECENT HANDLE ON CURRENT CONVECTION AND PRECIPITATION. HIGH POPS THEN LINGER LATER TONIGHT INTO MONDAY...WITH WARM CONVEYOR BELT RAIN OVER THE AREA. ISOLATED THUNDER KEPT WITH WEAK ELEVATED CAPE. COULD SEE LIGHTER RAIN IN THE AFTERNOON IN THE WESTERN COUNTIES...AS BEST UPWARD VERTICAL MOTION SHIFTS NORTH OF THAT AREA FOR A TIME. QPF TONIGHT INTO MONDAY NIGHT IS FORECAST BETWEEN 1.75 AND AROUND 2.00 INCHES. GUSTY EAST WINDS WILL LINGER TONIGHT AND MONDAY...WITH TIGHT PRESSURE GRADIENT ACROSS THE AREA. GUSTS TO 30 TO 33 KNOTS ARE EXPECTED AT TIMES. MAY SEE A FEW GUSTS AND SUSTAINED WINDS GET NEAR WIND ADVISORY LEVELS...MAINLY IN THE WEST...WITH STRONG LOW LEVEL WINDS JUST OFF THE SURFACE. MOST GUSTS WILL REMAIN BELOW CRITERIA. TEMPERATURES WILL REMAIN COOL WITH THE RAIN AND GUSTY EAST WINDS. MONDAY NIGHT THROUGH WEDNESDAY...FORECAST CONFIDENCE MEDIUM. THE OCCLUDED LOW WILL BE OVER FAR ERN NE EARLY MONDAY EVENING AND SLOWLY MOVE EWD. THE UPPER TROUGH AXIS EXTENDING FROM THE OCCLUSION WILL PIVOT NWD THROUGH WI MON NT...BRINGING ANOTHER ROUND OF WIDESPREAD MODERATE RAINFALL. THE OCCLUDED FRONT WILL MAKE IT TO THE IL/WI BORDER BY 12Z TUE. THE SFC LOW WILL THEN BECOME A BROAD N-S TROUGH OF LOW PRESSURE FROM SRN WI THROUGH IL. THIS WILL BRING THE OCCLUDED FRONT NWD INTO CENTRAL WI...THUS MILDER TEMPS ARE EXPECTED FOR TUE BUT SHOWERY CONDITIONS WILL CONTINUE ALONG WITH CHANCES OF TSTORMS WITH THE WARMER AND MORE UNSTABLE CONDITIONS. THE LARGE UPPER LOW OVER THE UPPER MS RIVER VALLEY WILL THEN AID IN ANOTHER ROUND OF CYCLOGENESIS OVER MI TUE NT BUT THAT WILL ALSO QUICKLY OCCLUDE WITH THE LOW OVER WI OR MI FOR WED. THE LARGE UPPER LOW ALOFT WILL ENSURE SHOWERY CONDITIONS CONTINUING THROUGH THIS PERIOD. AROUND 2 INCHES OF RAIN IS FORECAST FROM TNT THROUGH MON NT WITH SHOWERY CONDITIONS EXPECTED AFTERWARD. REISSUED THE HYDROLOGIC OUTLOOK WITH MANY RIVERS EXPECTED TO BE AT ABOVE NORMAL FLOWS WITH A FEW REACHING MINOR FLOOD STAGE. LONG TERM... THURSDAY THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM THE LARGE OCCLUDED LOW WILL TAKE UNTIL ABOUT SAT TO MOVE AWAY WITH A WEAK RIDGE OF HIGH PRESSURE SHIFTING EWD ACROSS THE REGION. ANOTHER STRONG SHORTWAVE TROUGH AND SFC WAVE WITH THE POLAR JET STREAM WILL THEN QUICKLY MOVE EWD ACROSS WI FOR SUN. THUS THE RAIN CHANCES WILL CONTINUE THROUGH THE EXTENDED AS WELL. BELOW NORMAL TEMPS TO PREVAIL. AVIATION/00Z TAFS/... SCATTERED SHOWERS AND AN ISOLATED STORM ARE POSSIBLE THROUGH EARLY THIS EVENING...ESPECIALLY AT MADISON. COULD SEE MVFR VISIBILITIES IF ANY OF THESE GO OVER THE AIRPORT. FOR NOW...MAY PUT VICINITY SHOWERS IN TAF AT MADISON. MAIN ROUND OF MODERATE RAIN/SHOWERS WILL MOVE NORTHEAST INTO TAF SITES THIS EVENING...BY 03Z MONDAY AT MADISON AND 06Z MONDAY AT THE EASTERN SITES. THE RAIN WILL THEN LINGER LATER TONIGHT AND MONDAY. MVFR CEILINGS AND VISIBILITIES ARE EXPECTED DURING THIS TIME...WITH IFR VISIBILITIES POSSIBLE IN HEAVIER RAIN. ISOLATED THUNDERSTORMS ARE POSSIBLE...BUT WILL LEAVE MENTION OUT OF TAFS FOR NOW. GUSTY EAST WINDS WILL LINGER TONIGHT AND MONDAY...AS LOW PRESSURE SLOWLY MOVES TOWARD THE REGION FROM THE WEST. SOME GUSTS TO 30 KNOTS ARE EXPECTED. SOME POTENTIAL FOR LOW LEVEL WIND SHEAR TONIGHT INTO EARLY MONDAY MORNING...AS EASTERLY 1500 FOOT WINDS APPROACHING 50 TO 55 KNOTS. STILL FEEL THAT SUSTAINED WINDS AND GUSTS WILL BE STRONG ENOUGH TO PREVENT MENTION IN TAFS FOR NOW. MARINE... SMALL CRAFT ADVISORY CONTINUES FOR THE NEARSHORE WATERS OF LAKE MICHIGAN UNTIL LATER TUESDAY AFTERNOON. WINDS ARE EXPECTED TO RAMP BACK UPWARDS BY EARLY EVENING...WITH TIGHT PRESSURE GRADIENT WITH APPROACHING LOW PRESSURE FROM THE WEST. GUSTY EAST WINDS ARE THEN EXPECTED TO LINGER INTO MONDAY. GUSTS TO 30 KNOTS ARE EXPECTED TONIGHT INTO MONDAY...WITH A FEW TO 35 KNOTS. NOT EXPECTING GALE FORCE GUSTS TO BE FREQUENT ENOUGH FOR A GALE WARNING AT THIS TIME. WINDS WILL THEN SLOWLY WEAKEN MONDAY NIGHT AND TUESDAY. HIGH WAVES ARE EXPECTED WITH THE GUSTY ONSHORE WINDS TONIGHT INTO TUESDAY AFTERNOON. THEY SHOULD BUILD TO 6 TO 10 FEET TONIGHT INTO MONDAY...WITH SOME 8 TO 12 FOOT WAVES POSSIBLE SOUTH OF NORTH POINT LIGHTHOUSE. WAVES WILL SLOWLY SUBSIDE MONDAY NIGHT INTO TUESDAY...FALLING BELOW 4 FEET BY LATE TUESDAY AFTERNOON. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 4 PM CDT TUESDAY FOR LMZ643>646. && $$ UPDATE...DAVIS TONIGHT/MONDAY AND AVIATION/MARINE...WOOD MONDAY NIGHT THROUGH SUNDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
605 PM CDT SUN APR 27 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 313 PM CDT SUN APR 27 2014 CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED TROUGHING ALONG THE BRITISH COLUMBIA COAST...A POTENT NEGATIVELY TILTED TROUGH AND UPPER LOW OVER KANSAS...AND A STRONG UPPER LEVEL RIDGE FROM THE SOUTHEASTERN U.S. INTO MANITOBA. IN- BETWEEN THE UPPER LOW AND RIDGE...PROFILER AND VWP DATA SHOWED A 30- 50 KT JET CORE AT 850MB FROM THE WESTERN GULF OF MEXICO NORTHWARD THROUGH MINNESOTA RAPIDLY TRANSPORTING MOISTURE NORTHWARD. GOES PRECIPITABLE WATER IMAGERY DEPICTED VALUES OF 1-1.5 INCHES ENCOMPASSING MUCH OF IOWA SOUTHWARD INTO LOUISIANA...WITH LOWER VALUES OF LESS THAN 0.5 INCH OVER MUCH OF KANSAS INTO WESTERN OKLAHOMA WHERE A DRY SLOT EXISTS. ALONG AND JUST EAST/NORTHEAST OF THIS GRADIENT OF PRECIPITABLE WATER...NUMEROUS SHOWERS AND THUNDERSTORMS HAVE DEVELOPED FROM CENTRAL IOWA AND MISSOURI. SOME OF THESE STORMS ARE INTENSE TOO...MOSTLY SOUTH OF I-80 WHERE 750-1500 J/KG OF MLCAPE EXISTS PER RAP ANALYSIS. FARTHER NORTHEAST... SHOWERS AND EMBEDDED THUNDERSTORMS THAT AFFECTED THE FORECAST AREA THIS MORNING HAVE MOSTLY LIFTED NORTH OF I-90. THESE ARE ASSOCIATED WITH MID-LEVEL FRONTOGENESIS AND RIGHT ENTRANCE REGION OF AN UPPER JET OVER LAKE SUPERIOR. LASTLY...A TIGHT PRESSURE GRADIENT IN PLACE COMBINED WITH THAT AFOREMENTIONED STRONG 850MB JET CORE HAS LED TO BRISK EAST WINDS. THESE HAVE BEEN SUSTAINED AT 15-35 MPH WITH GUSTS OF 25-45 MPH...STRONGEST WEST OF THE MS RIVER. VERY GOOD MODEL AGREEMENT CONTINUES THAT THE BAND OF SHOWERS AND THUNDERSTORMS TO OUR SOUTHWEST WILL LIFT NORTHEAST THROUGH THE FORECAST AREA TONIGHT INTO MONDAY MORNING. THIS IS ALL IN RESPONSE TOO THE UPPER LOW AND ASSOCIATED SHORTWAVE TROUGH LIFTING INTO NEBRASKA AND IOWA BY 18Z MONDAY. THE QUESTION IS AMOUNT WHICH HAS BIG IMPACTS ON POTENTIAL FOR RIVER FLOODING. THE AMOUNT HAS STRONG TIES TO EVOLUTION OF CONVECTION OVER WESTERN MISSOURI AND SOUTHWEST IOWA IN WHICH THERE ARE THREE SCENARIOS... 1. THE CONVECTION TURNS INTO A FORWARD PROPAGATING SQUALL LINE...ESSENTIALLY LIMITING HEAVIER RAINFALL INTO THE FORECAST AREA. THIS SQUALL LINE FALLS APART OVER ILLINOIS LATE THIS EVENING AS IT RUNS INTO MORE STABLE AIR. 2. THE CONVECTION WEAKENS AS IT PUSHES EAST...RESULTING IN A PERSISTENT WARM CONVEYOR BELT OF SHOWERS AND EMBEDDED THUNDERSTORMS. THE TRAINING FACTOR COMES INTO PLAY...ALLOWING FOR HEAVIER RAINFALL...ESPECIALLY ACROSS NORTHEAST IOWA THIS EVENING. 3. THE CONVECTION WEAKENS AS IT PUSHES EAST...AND ESSENTIALLY MUCH OF THE SHOWER ACTIVITY FALLS APART BY 04Z. ALL THREE IDEAS ARE CERTAINLY PLAUSIBLE...BUT IT IS SERIOUSLY WORTH NOTING THE CONVECTION HAS BEEN OUTRUNNING MOST MODELS. THE ONLY MODEL THAT HAS BEEN HANDLING THIS WELL IS THE 00Z SPC WRF-NMM... WHICH IS SCENARIO NUMBER 3 ABOVE. THEREFORE...HAVE TRIED TO LEAN MORE TOWARDS THAT FOR PRECIPITATION CHANCES AND QPF. STILL...THE FORECAST MAY BE OVERDONE...ESPECIALLY WITH PRECIPITATION CHANCES IN THAT 04-09Z TIME FRAME. WOULD THINK THAT PERSISTENT 850MB MOISTURE TRANSPORT WOULD AT LEAST CONTINUE SOME SHOWER ACTIVITY AND NOT COMPLETELY END...THUS THE HIGHER CHANCES IN THE FORECAST. ALL THREE SCENARIOS ABOVE REGENERATE SHOWERS AND EMBEDDED THUNDERSTORM ACTIVITY OVER THE FORECAST AREA AROUND 09Z...ASSOCIATED WITH DPVA FROM THE APPROACHING NEGATIVELY TILTED SHORTWAVE TROUGH. SEE HYDROLOGY SECTION BELOW FOR IMPACT ON RIVERS. AFTER THE RAIN AND CONVECTION TONIGHT/MONDAY MORNING...ATTENTION THEN TURNS TO A WARM FRONT PROGGED TO LIFT THROUGH IOWA. THE MAJORITY OF MODELS KEEP IT JUST SOUTH OF THE FORECAST AREA...EITHER ALONG OR SOUTH OF US-20. THE NORTHWARD PROGRESS OF THE FRONT HINGES QUITE A BIT ON MORNING PRECIPITATION. CONVECTION LOOKS LIKELY TO FIRE ALONG AND SOUTH OF THIS FRONTAL BOUNDARY. SOME OF THIS CONVECTION COULD CREEP INTO FAR SOUTHERN PORTIONS OF THE FORECAST AREA IN THE LATE AFTERNOON...AND POSSIBLY BE SEVERE. NOTE THAT A VERY TIGHT GRADIENT OF INSTABILITY WILL EXIST...SO ANY SEVERE THREAT SHOULD BE CONFINED TO FAYETTE EAST TO GRANT COUNTIES. LASTLY...REGARDING THE WIND ADVISORY...AS EXPECTED THE CONDITIONS HAVE BEEN MARGINAL. WILL KEEP IT GOING THROUGH 9 PM AS SUSTAINED SPEEDS CONTINUE TO PULSE UP AND DOWN TO 30 MPH. THERE IS A POSSIBILITY THE ADVISORY MAY NEED TO BE EXTENDED TO MIDNIGHT SEEING SOME LAV GUIDANCE HOLDING RST...TOB AND OLZ BETWEEN 25-30 KT TO 06Z. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 313 PM CDT SUN APR 27 2014 THE UPPER LOW OVER NEBRASKA ON MONDAY IS THE MAIN FEATURE OF FOCUS FOR THE LONG TERM PERIOD. MODELS CONTINUE TO SUGGEST THIS UPPER LOW WILL PLAGUE THE FORECAST AREA THROUGH AT LEAST THURSDAY AS IT SLOWLY TRACKS NORTHEAST INTO UPPER MICHIGAN. HEADING INTO THE WEEKEND...THE UPPER PATTERN REMAINS COOL AS RIDGING HOLDS IN PLACE OVER THE WESTERN U.S. INTO WESTERN CANADA...CAUSING TROUGHING TO PERSIST OVER THE GREAT LAKES REGION. THIS IS VERY WELL AGREED UPON BY THE 27.06Z/12Z GFS AND 27.00Z/12Z ECMWF. FOR MONDAY NIGHT INTO TUESDAY. CONDITIONS REMAIN FAVORABLE FOR A BAND OF SHOWERS TO FORM JUST NORTH OF THAT WARM FRONTAL BOUNDARY IN IOWA MONDAY EVENING...ASSOCIATED WITH DPVA FORCING AND 800-900MB FRONTOGENESIS. THIS BAND...AFFECTING LOCATIONS SOUTH OF I-90 MONDAY EVENING...SHOULD TRANSLATE NORTHWARD TO ALONG AND NORTH OF I-90 BY TUESDAY MORNING...WITH PRECIPITATION POSSIBLY TAILING OFF TO THE SOUTH. THEN WE GET INTO A COLD CONVEYOR BELT SCENARIO FOR TUESDAY AFTERNOON OVER NORTHWESTERN SECTIONS OF THE FORECAST AREA. OTHER SHOWERS SHOULD POP UP ELSEWHERE UNDER THE UPPER LOW DUE TO MID LEVEL COLD AIR. THERE COULD EVEN BE SOME THUNDER WITH THEM...BUT CONFIDENCE TOO LOW TO INCLUDE RIGHT NOW. FROM TUESDAY NIGHT THROUGH THURSDAY...THE FORECAST AREA PRETTY MUCH SITS IN A GRADUALLY WEAKENING COLD CONVEYOR BELT OF SHOWERS...WITH PERHAPS SOME DIURNAL ENHANCEMENT THAT COULD INCREASE COVERAGE. GIVEN HIGH CONFIDENCE OF PRECIPITATION AROUND...HAVE USED COVERAGE VERBIAGE. WITH PLENTY OF CLOUDS AND SHOWER ACTIVITY AROUND... COMBINED WITH 850MB TEMPS ONLY AROUND 0C PLUS OR MINUS 2 C...EXPECT CHILLY TEMPERATURES. CHANCES OF PRECIPITATION CONTINUE OFF AND ON FOR THURSDAY NIGHT RIGHT THROUGH SUNDAY AS SHORTWAVES DROP SOUTHEAST THROUGH THE GREAT LAKES TROUGHING. SOME SIGNAL THAT A SHORTWAVE TROUGH ON SUNDAY MIGHT BE MORE POTENT...SO CHANCES MAY NEED TO BE RAISED BEYOND THE CURRENT FORECAST OF A MODEL CONSENSUS. AS IT STANDS RIGHT NOW THE AIR IS NOT COLD ENOUGH FOR SNOW...BUT ITS NOT FAR OFF. 850MB STANDARDIZED ANOMALIES GENERALLY HOLD AROUND 1 STANDARD DEVIATION BELOW NORMAL...OR BETWEEN -4C AND 0C. NEEDLESS TO SAY...BELOW NORMAL TEMPERATURES CONTINUE. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 605 PM CDT SUN APR 27 2014 CHALLENGING FORECAST AS THERE WILL BE PERIODS OF RA/TSRA...AND PIN POINTING WHERE THE BREAKS IN THE PCPN WILL BE IS PROBLEMATIC. IN ADDITION...WINDS WILL STAY STRONG AND GUSTY THROUGH TUESDAY AS TIGHT PRESSURE GRADIENT PERSISTS FOR MUCH OF THE UPPER MISSISSIPPI RIVER VALLEY - WITH THE RESPONSIBLE SFC LOW JUST TO THE SOUTH. WINDS WILL ALSO REMAIN STRONG JUST OFF THE SFC...50-60 KTS AROUND 2 KFT. LLWS WILL BE A FACTOR FOR KLSE INTO MONDAY AFTERNOON. BACK TO THE PCPN - FIRST BAND OF SHRA/TS GOING TO TRACK NORTHWARD ACROSS KRST/KLSE THRU 02-03Z. SHOULD SEE A BREAK IN THE PCPN AFTER THAT...ALTHOUGH ENOUGH UNCERTAINTY THAT WILL HOLD A VCSH FOR STRAGGLERS THAT COULD LINGER. ANOTHER BATCH OF SHRA COULD DEVELOP ON THE NOSE OF AN INCREASING LOW LEVEL JET TOWARD 06Z. A MORE SIGNIFICANT SWATH OF THE WIDESPREAD SHRA/TS WILL RETURN NEAR 12Z MON AS AN UPPER LEVEL SHORTWAVE TROUGH SPINS NORTHEAST OUT OF THE SOUTHERN PLAINS. SHOULD MAKE FOR A SOGGY MORNING WITH MVFR VSBYS. ANTICIPATING CIGS IN THE IFR/MVFR RANGE BY THIS TIME. MODEL TRENDS WOULD FAVOR LIFTING THIS NORTH OF THE TAF SITES BY 18- 20Z...BRINGING ANOTHER MOSTLY DRY PERIOD FOR THE AFTERNOON. HOWEVER...ANOTHER ROUND OF PCPN APPEARS LIKELY AS SHRA/TS FIRE UP ALONG A WARM FRONT JUST TO THE SOUTH LATE AFTERNOON/EVENING...WHICH COULD PUSH NORTH. BOTTOM-LINE...AN EXTENDED PERIOD OF WET WEATHER WITH IFR/MVFR IMPLICATIONS FOR CIGS AND VSBYS. SOME THUNDER WILL BE POSSIBLE. WINDS ARE GOING TO STAY STRONG...MOSTLY EAST-NORTHEAST...AND LLWS WILL REMAIN A CONCERN AT KLSE INTO MON AFTERNOON. && .HYDROLOGY... ISSUED AT 313 PM CDT SUN APR 27 2014 PRECIPITATION FORECASTS REMAIN VERY UNCERTAIN FOR TONIGHT AS SHOWERS AND EMBEDDED THUNDERSTORMS OVER CENTRAL IOWA ARE MOVING FASTER THAN MOST MODELS. IN FACT...THE ONE MODEL THAT IS HANDLING THE PRECIPITATION WELL SUGGESTS WE COULD HAVE A BREAK OF 6 HOURS OF NO PRECIPITATION TONIGHT AFTER THEY PASS. ADDITIONALLY...THE CONVECTION TO THE SOUTH MAY END UP INGESTING MORE OF THE MOISTURE...LIMITING HEAVIER RAINFALL OVER THE FORECAST AREA. THIS SCENARIO IS LOOKING MORE LIKELY FOR TONIGHT. BETTER CONFIDENCE FOR MUCH OF THE AREA TO SEE ANYWHERE FROM 1/4 TO 1 INCH OF RAIN ON MONDAY...WITH ANOTHER 1/2 TO 1 INCH FROM MONDAY NIGHT INTO TUESDAY. IN SUMMARY...BASED ON RFC FORECAST DATA...CONFIDENCE WAS ONLY HIGH ENOUGH TO PUT A FLOOD WATCH ON THE TURKEY RIVER. SHOULD AROUND 1 INCH MATERIALIZE OVER THE BASIN THIS EVENING...THE WATCH WILL NEED TO BE UPGRADED. ELSEWHERE...HAVE CONTINUED THE ESF. THERE ARE SOME SIGNALS THAT HEAVIER QPF COULD FALL OVER WISCONSIN. SHOULD THIS MATERIALIZE...MORE FLOOD WATCHES FOR AREA RIVERS MAY BE REQUIRED. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR MNZ086-087-094-095. IA...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR IAZ008>010-018-019- 029. && $$ SHORT TERM...AJ LONG TERM....AJ AVIATION.....RIECK HYDROLOGY....AJ
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND SUNDAY ISSUED AT 251 PM CDT SAT APR 26 2014 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE RIDGE AXIS EXTENDING SOUTHWARD FROM A HUDSON BAY HIGH AND BISECTING WISCONSIN EARLY THIS AFTERNOON. EAST OF THIS RIDGE AXIS...NORTHEAST WINDS HAVE BEEN ADVECTING A LOW STRATUS DECK OVER MUCH OF NORTH-CENTRAL AND NORTHEAST WISCONSIN. TEMPS HAVE BEEN HELD BACK DUE TO THESE CLOUDS AND RANGE THROUGH THE 40S. LOOKING OUT TO THE WEST...MID AND HIGH CLOUDS ARE SPILLING OVER A SHARP MID-LEVEL RIDGE AXIS OVER THE NORTHERN PLAINS. THIS IS AHEAD OF A DEEP TROUGH MOVING ACROSS THE WESTERN CONUS. ALSO TO THE EAST OF THIS TROUGH...A SURFACE WARM FRONT IS SHIFTING NORTHWARD OVER THE CENTRAL PLAINS WITH RETURN FLOWING INCREASING. AS THIS WARM FRONT LIFTS NORTH OVER THE NEXT 24 HOURS...LIGHT PRECIP CHANCES ARE THE MAIN FORECAST CONCERN. TONIGHT...HUDSON BAY HIGH RIDGE AXIS WILL SHIFT FROM THE CENTRAL TO THE EASTERN GREAT LAKES WHILE LOW PRESSURE EMERGES INTO THE CENTRAL PLAINS. AHEAD OF THE LOW...MID AND HIGH CLOUDS WILL BE PUSHING ACROSS THE STATE THIS EVENING BUT DRY NORTHEAST TO EAST WINDS WILL KEEP THE AREA DRY. BY LATE TONIGHT THOUGH...40-50 KTS OF FLOW WILL RIDE OVER THE MID-LEVEL THERMAL GRADIENT OVER THE NORTHERN MISSISSIPPI VALLEY. THIS WILL CAUSE CLOUDS TO LOWER OVER CENTRAL AND EAST-CENTRAL WISCONSIN AND VARIOUS MODELS BRING IN LIGHT PRECIP INTO THE AREA BY 09Z. BECAUSE OF THE DRY EAST FLOW...THINK THIS IS TOO AGGRESSIVE AND HAVE BACKED OFF PRECIP CHANCES A LITTLE AFTER MIDNIGHT. MAY HAVE ENOUGH SATURATION FOR LIGHT RAIN BETWEEN 09-12Z SO HAVE KEPT POPS IN THE HIGH CHANCE RANGE BUT STILL THINK THERE IS POTENTIAL FOR THE DRY AIR TO WIN OUT. THE EAST WINDS WILL BE BREEZY TONIGHT...WHICH WILL MAKE IT FEEL BLUSTERY AND DAMP. LOWS RANGING FROM THE UPPER 20S NORTH TO UPPER 30S SOUTH. SUNDAY...THE LOW PRESSURE SYSTEM WILL MOVE VERY LITTLE EASTWARD OVER THE CENTRAL PLAINS...BUT THE RETURN FLOW WILL PUSH NORTHEAST ACROSS THE STATE OVER THE COURSE OF THE DAY. AS THIS OCCURS...THE DRY AIR WILL LOSE ITS INFLUENCE GRADUALLY...AND PRECIP CHANCES WILL INCREASE OVER CENTRAL AND EAST-CENTRAL WISCONSIN. THE RAIN SHOULD REMAIN LIGHT...BUT INCREASING MID-LEVEL FGEN COMBINED WITH PWATS OVER AN INCH SUPPORT LIKELY POPS OVER CENTRAL WISCONSIN AND THE SOUTHERN FOX VALLEY DURING THE AFTERNOON. TEMPS ARE DIFFICULT DEPENDING UPON THE COVERAGE OF RAIN OVER SOUTHERN WISCONSIN...AND THE LACK OF LOW CLOUDS OVER NORTHEAST WISCONSIN. WILL GO WITH FAIRLY UNIFORM TEMPS RANGING FROM THE UPPER 40S TO LOWER 50S. .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY ISSUED AT 251 PM CDT SAT APR 26 2014 PCPN TRENDS THROUGHOUT THE PERIOD...AND STRONG E-NE WINDS EARLY NEXT WEEK...ARE THE MAIN FCST CONCERNS. AN UPPER LEVEL RIDGE WILL SHIFT NORTHEAST SUNDAY NIGHT AND MONDAY...AS AN UPPER LEVEL LOW MOVES INTO SOUTH DAKOTA/NEBRASKA. THIS WILL CAUSE PCPN TO SLOWLY SHIFT NE ACROSS THE FORECAST AREA...ALTHOUGH ITS PROGRESS WILL BE SLOWED ACROSS FAR N/NE WI...DUE TO DRY AIR FEEDING OUT OF A STRONG HUDSON BAY HIGH. HAVE ADJUSTED POPS/QPF TO ACCOUNT FOR THE DRY AIR. FARTHER SOUTH...ACROSS C/EC WI...QPF AMOUNTS WILL PROBABLY EXCEED AN INCH FROM LATE SUNDAY NIGHT THROUGH MONDAY. A STRONG PRESSURE GERADIENT WILL SET UP BETWEEN THE HUDSON BAY HIGH AND LOW PRESSURE APPROACHING FROM THE NORTHERN PLAINS. EAST WINDS OF 15 TO 25 MPH...WITH GUSTS TO 30 TO 35 MPH...CAN BE EXPECTED ACROSS THE REGION. STRONG NE WINDS (GUSTING TO 35 TO 40 MPH) ARE ALSO POSSIBLE OVER THE FOX VALLEY MONDAY NIGHT INTO TUESDAY. THE UPPER LEVEL LOW IS EXPECTED TO GRADUALLY SHIFT NE...REMAIN OVER THE WESTERN GREAT LAKES FROM TUESDAY THROUGH THURSDAY...THEN WEAKEN INTO AN OPEN TROF AND SHIFT NE INTO CANADA BY FRIDAY. ALTHOUGH PCPN WILL BE IN THE FCST THROUGHOUT THE PERIOD...THE BEST CHANCES SHOULD OCCUR AS STRONG S/W TROFS ROTATE THROUGH LATE MONDAY NIGHT INTO TUESDAY MORNING...AND OVER NORTHERN WI LATE TUESDAY NIGHT INTO WEDNESDAY. PCPN SHOULD BECOME MORE SCATTERED IN NATURE DURING THE LATTER HALF OF THE WEEK. OVERALL...MOST OF THE PCPN SHOULD FALL AS RAIN...ALTHOUGH A MIX OF RAIN/SNOW IS POSSIBLE OVER PARTS OF NC/FAR NE WI LATE MONDAY NIGHT AND EARLY TUESDAY...AND AT TIMES FROM WEDNESDAY NIGHT THROUGH FRIDAY. TEMPERATURES WILL REMAIN WELL BELOW NORMAL...WITH HIGHS IN THE 40S AND LOWER 50S...THROUGH MIOST OF THE PERIOD. SOME MODERATION IS EXPECTED LATE IN THE WEEK AS THE UPPER LOW SHIFTS OUT OF THE REGION. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1225 PM CDT SAT APR 26 2014 SCATTERED TO BROKEN MVFR CLOUDS ACROSS THE NORTHEAST HALF OF WISCONSIN WILL LIFT TO MVFR BY MIDDAY...BUT WILL TAKE UNTIL MID TO LATE AFTERNOON TO DISSIPATE. MID AND HIGH CLOUDS WILL THEN ARRIVE LATER THIS AFTERNOON AND LOWER THROUGH THE EVENING AHEAD OF THE NEXT STORM SYSTEM. MODELS TRY TO BRING LIGHT RAIN INTO CENTRAL WISCONSIN AFTER MIDNIGHT TONIGHT...BUT THINKING DRY EAST FLOW WILL DELAY THIS ARRIVAL OF PRECIP UNTIL AT LEAST SUNDAY MORNING. UNCERTAINTY IS HIGH ENOUGH TO JUST INDICATE VCSH IN THE TAFS FOR NOW. CEILINGS AND VISIBILITIES SHOULD REMAIN RELATIVELY HIGH EVEN IF LIGHT RAIN DOES MOVE IN. BETTER CHANCES OF LIGHT RAIN WILL OCCUR SUNDAY AFTERNOON. && .HYDROLOGY... ISSUED AT 251 PM CDT SAT APR 26 2014 RAINFALL TOTAL OF 1.5 TO 2.5 INCHES ARE EXPECTED ACROSS THE SOUTHERN TWO-THIRDS OF THE FORECAST AREA FROM SUNDAY NIGHT THROUGH WEDNESDAY. THIS COULD RESULT IN SOME MINOR RIVER FLOODING...AS SEVERAL RIVERS STILL REMAIN ABOVE BANKFULL. PLAN TO ISSUE AN ESF AND MENTION FLOODING CONCERNS IN THE HWO. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KIECKBUSCH AVIATION.......MPC HYDROLOGY......KIECKBUSCH
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1210 PM CDT SAT APR 26 2014 .UPDATE...AREA OF LOW CLOUDS HAVE MOVED SOUTHWESTWARD INTO THE NORTHEAST COUNTIES THIS MORNING AND HAVE LINGERED. THE SOUTHWESTWARD ADVANCE SEEMS TO HAVE STOPPED FOR THE MOMENT...AS DAYTIME HEATING ERODES THE LEADING EDGE OF THIS CLOUD BAND. COULD STILL SEE THIS BAND SLIDE A BIT FURTHER SOUTHWEST INTO THE AREA INTO THE AFTERNOON HOURS. THESE CLOUDS SHOULD GRADUALLY BECOME MORE SCATTERED TO BROKEN BY THE LATE AFTERNOON HOURS...WITH DAYTIME HEATING. MIDDLE TO HIGH CLOUDS SHOULD MOVE EAST INTO THE AREA THIS AFTERNOON AS WELL. NORTHEAST WINDS WITH THE CLOUDS SHOULD KEEP HIGHS IN THE MID 40S IN THE CLOUDY AREAS THIS AFTERNOON. MID 40S WILL ALSO BE FOUND NEAR LAKE MICHIGAN WITH THE ONSHORE WINDS. HIGHS ELSEWHERE SHOULD RISE INTO THE 50S...NEAR 60 IN LAFAYETTE COUNTY. && .AVIATION/18Z TAFS/...AREA OF MVFR CEILINGS MAY AFFECT TAF SITES THROUGH THE MID AFTERNOON HOURS. HOWEVER...CONFIDENCE IS LOW WITH HOW FAR SOUTHWEST THEY WILL MOVE...SO WILL LEAVE FEW TO SCATTERED IN TAFS FOR NOW. NORTHEAST WINDS WILL BECOME EAST THIS AFTERNOON AT MADISON...WITH NORTHEAST WINDS AT THE EASTERN SITES. SHOULD SEE GUSTS TO 18 KNOTS AT TIMES THIS AFTERNOON. WINDS WILL VEER EAST TONIGHT AT THE EASTERN SITES...AND BECOME STRONGER LATER TONIGHT INTO SUNDAY AT ALL SITES. GUSTS TO 30 KNOTS ARE EXPECTED BY LATER TONIGHT...LASTING INTO SUNDAY. SOME 35 KNOT GUSTS ARE POSSIBLE. THERE IS SOME LOW LEVEL WIND SHEAR POTENTIAL TONIGHT INTO EARLY SUNDAY MORNING...AS 1500 FOOT WINDS MAY REACH 45 KNOTS. HOWEVER...SURFACE WINDS AND GUSTS SHOULD BE STRONG ENOUGH TO NEGATE MENTION FOR NOW. VFR CEILINGS TONIGHT INTO SUNDAY WILL GRADUALLY LOWER. RAIN SHOWERS ARE POSSIBLE MAINLY LATER TONIGHT INTO SUNDAY. FOR NOW...WILL CONTINUE MENTION IN TAFS FOR MADISON. THE EASTERN SITES MAY NOT SEE THE SHOWERS UNTIL SUNDAY NIGHT. MVFR CEILINGS AND VISIBILITIES ARE POSSIBLE...BUT WILL LEAVE OUT MENTION DUE TO LOW CONFIDENCE. && .MARINE...NORTHEAST WINDS OF 15 TO 20 KNOTS ARE EXPECTED THIS AFTERNOON...WITH WAVES OF 2 TO 4 FEET. A FEW GUSTS MAY REACH 22 KNOTS...BUT NOT FREQUENT ENOUGH TO ISSUE A SMALL CRAFT ADVISORY. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FOR SUNDAY INTO AT LEAST TUESDAY...WITH PERSISTENT AND GUSTY ONSHORE WINDS AS LOW PRESSURE APPROACHES THE REGION. HIGH WAVES ARE LIKELY AS WELL...BUILDING INTO THE 5 TO 10 FOOT RANGE BY SUNDAY NIGHT. DO NOT THINK GALES WILL OCCUR SUNDAY...AS INVERSION ABOVE SURFACE SHOULD LIMIT MIXING OF WINDS TO AROUND 30 KNOTS AT BEST. && .PREV DISCUSSION... /ISSUED 347 AM CDT SAT APR 26 2014/ SHORT TERM... TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM. SURFACE OBS AND LOCAL RADAR SHOW COLD FRONT HAD PUSHED THROUGH ALL BUT THE FAR SW PORTION OF CWA BY 07Z. AS VORT MAX OVER THE SOO MOVES OFF TO THE EAST OVER LAKE HURON...A COMBINATION OF 700 MB WARM AIR ADVECTION AND CONVERGENCE ON PERIPHERY OF MID-LEVEL CYCLONIC FLOW IS PRODUCING ACCAS SHOWERS OVER NRN IL...WELL DEPICTED ON 00Z GFS AND HI-RES/RAPID UPDATE MODELS. STEEP LAPSE RATES ABOVE 850 MB AND MEAGER ELEVATED CAPE...REFLECTED ON RAP SOUNDINGS...PRODUCING LIGHT SHOWERS WITH REPORTS OF IN-CLOUD LIGHTNING OVER NRN IL. MODELS ALL KEEP THIS BAND OUT OF THE CWA AS IT SHIFTS TO THE EAST-SOUTHEAST OF IL BY 12Z. SOUTHERN PORTION OF SURFACE HIGH SETTLING OVER STATE TODAY AND 500 MB RIDGING WILL KEEP THE DAYTIME HOURS DRY...WITH A COOL NORTHEAST TO EAST WIND PREVENTING HIGHS IN THE LAKESHORE COUNTIES FROM GETTING OUT OF THE 40S. LOW TO MID 50S EXPECTED WEST OF THE KETTLE MORAINE...WITH MID-UPR 50S FROM MADISON WEST...WITH A 60 OR TWO IN THE FAR SW. MODELS DEPICTING NICE BAND OF MAINLY ISENTROPICALLY-DRIVEN 700 MB OMEGA AND HIGHER RH CROSSING REGION AFTER 00Z SUNDAY...AND ARE PRODUCING SOME LIGHT QPF. BUT SIMILAR TO EARLIER THIS WEEK...CROSS SECTIONS AND FORECAST SOUNDINGS SHOWING RELATIVELY DRY EASTERLY FLOW PREVENTING SATURATION BELOW 7K-8K FEET THROUGH MOST OF THE NIGHT...WITH SOME SATURATION IN THE FAR WEST AFTER 06Z. WILL KEEP POPS NO HIGHER THAN THE CHANCE CATEGORY PRIOR TO 12Z EXCEPT FOR LOW LIKELY POPS IN THE EXTREME WEST AFTER 09Z. SUNDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM. THE OCCLUDED LOW PRESSURE SYSTEM WILL STALL OVER THE CENTRAL PLAINS UNTIL EARLY NEXT WEEK. THE 925MB WARM FRONT WILL BE STATIONED ACROSS NORTHERN IL ON SUNDAY...THEN CREEP NORTHWARD INTO FAR SOUTHERN WI THROUGH MONDAY NIGHT. MEANWHILE...THE 850MB WARM FRONT WILL REMAIN STATIONARY OVER CENTRAL WI. THE INITIAL WARM AIR ADVECTION SHOWERS ON SUNDAY WILL STRUGGLE TO OVERCOME THE LOW LEVEL DRY AIR IN PLACE. THE DEEP MOISTURE WILL FINALLY ARRIVE SUNDAY EVENING AS WAVES OF VORTICITY AND WARM AIR ADVECTION LEAD TO STRONG UPWARD MOTION OVER SOUTHERN WI. STEEP MID LEVEL LAPSE RATES AND THE STRONG OMEGA WILL ALLOW FOR EMBEDDED THUNDERSTORMS. MODERATE RAIN SHOWERS WITH PERIODS OF HEAVY RAIN WILL BE POSSIBLE SUNDAY NIGHT THROUGH MONDAY NIGHT. RAINFALL TOTALS DURING THIS TIME ARE ESTIMATED TO BE IN THE 1.3 TO 1.8 INCH RANGE WITH THE HIGHER TOTALS IN SW WI AND THE LOWER TOTALS OVER EAST CENTRAL WI. THIS RAIN AND THE ADDITIONAL EXPECTED NEXT WEEK WILL CAUSE MANY RIVERS TO REACH BANKFULL STAGE AND AT LEAST A FEW REACHING MINOR FLOOD STAGE. PLAN ON BREEZY EAST WINDS SUNDAY AND MONDAY WITH THE SURFACE LOW PARKED OVER NEBRASKA. THIS WILL KEEP TEMPERATURES VERY COOL IN THE UPPER 40S AND LOWER 50S. LONG TERM... TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM. THE OCCLUDED LOW WILL MEANDER NORTHEAST OVER THE UPPER GREAT LAKES THROUGH THURSDAY. THE DRY SLOT IS EXPECTED TO ARRIVE INTO SOUTHERN WI SOMETIME TUESDAY OR TUESDAY NIGHT WHICH WOULD CUT OFF THE DEEP MOISTURE. CLOUDS AND SCATTERED SHOWERS WILL CONTINUE TO BE POSSIBLE THROUGH FRIDAY DUE TO THE CYCLONIC FLOW AND LINGERING LOW LEVEL MOISTURE. WINDS WILL GENERALLY BE OUT OF THE EAST FOR THE WEEK WHICH MEANS COOLER NEAR THE LAKE WITH HIGHS IN THE UPPER 40S THERE AND LOWER 50S INLAND. MODELS ARE SHOWING ANOTHER UPPER TROUGH SWINGING DOWN THROUGH WI FOR NEXT WEEKEND WHICH WOULD ALLOW FOR MORE CLOUDS AND SHOWERS. THERE IS STILL UNCERTAINTY IN TIMING...SO THERE MAY BE A PERIOD OF DRY WEATHER ON FRIDAY OR SATURDAY. AVIATION/12Z TAFS/... VFR CONDITIONS THROUGH THE PERIOD WITH RAIN EXPECTED TO HOLD OFF UNTIL AROUND/SHORTLY AFTER 12Z SUNDAY...THOUGH A FEW SPRINKLES POSSIBLER BEFORE...ESPECIALLY AT KMSN AND WEST. NORTH WINDS THIS MORNING BEHIND COLD FRONT WILL TURN NORTHEAST AND THEN EAST AS RIDGE OF SURFACE HIGH PRESSURE NOSES OVER STATE...THEN INCREASE LATER TONIGHT WITH TIGHTENING GRADIENT AS RIDGE SHIFTS OVER LOWER MICHIGAN AND DEEPENING LOW PRESSURE MOVES OUT INTO THE CENTRAL PLAINS. MARINE... LOOKING AT NORTH WINDS THIS MORNING TURNING NORTHEAST AND EAST AS RIDGE OF SURFACE HIGH PRESSURE NOSES DOWN OVER STATE AND LAKE MICHIGAN...THEN INCREASE LATER TONIGHT WITH TIGHTENING GRADIENT AS RIDGE SHIFTS OVER LOWER MICHIGAN AND DEEPENING LOW PRESSURE MOVES OUT INTO THE CENTRAL PLAINS. THE SOMETIMES GUSTY ONSHORE WINDS ARE EXPECTED TO PERSIST FROM SUNDAY INTO WEDNESDAY...AS THE LOW PRESSURE SLOWLY APPROACHES THE AREA. THESE WIND GUSTS WILL LIKELY REACH SMALL CRAFT CRITERIA AT TIMES....WITH WINDS JUST A FEW HUNDRED FEET OFF THE SURFACE REACHING 40 KTS. DO NOT FEEL THESE STRONGER WINDS WILL MIX DOWN THROUGH THE NEAR-WATER STABLE LAYER...BUT A FEW GALE GUSTS ARE NOT OUT OF THE QUESTION...ESPECIALLY SUNDAY NIGHT INTO MONDAY EVENING. THE ONSHORE WINDS SHOULD ALSO GENERATE WAVES IN THE 3 TO 6 FOOT RANGE. A SMALL CRAFT ADVISORY MAY BE NEEDED AT TIMES DURING THIS PERIOD. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...WOOD TODAY/TONIGHT AND AVIATION/MARINE...REM SUNDAY THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
347 AM CDT SAT APR 26 2014 .SHORT TERM... TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM. SURFACE OBS AND LOCAL RADAR SHOW COLD FRONT HAD PUSHED THROUGH ALL BUT THE FAR SW PORTION OF CWA BY 07Z. AS VORT MAX OVER THE SOO MOVES OFF TO THE EAST OVER LAKE HURON...A COMBINATION OF 700 MB WARM AIR ADVECTION AND CONVERGENCE ON PERIPHERY OF MID-LEVEL CYCLONIC FLOW IS PRODUCING ACCAS SHOWERS OVER NRN IL...WELL DEPICTED ON 00Z GFS AND HI-RES/RAPID UPDATE MODELS. STEEP LAPSE RATES ABOVE 850 MB AND MEAGER ELEVATED CAPE...REFLECTED ON RAP SOUNDINGS...PRODUCING LIGHT SHOWERS WITH REPORTS OF IN-CLOUD LIGHTNING OVER NRN IL. MODELS ALL KEEP THIS BAND OUT OF THE CWA AS IT SHIFTS TO THE EAST-SOUTHEAST OF IL BY 12Z. SOUTHERN PORTION OF SURFACE HIGH SETTLING OVER STATE TODAY AND 500 MB RIDGING WILL KEEP THE DAYTIME HOURS DRY...WITH A COOL NORTHEAST TO EAST WIND PREVENTING HIGHS IN THE LAKESHORE COUNTIES FROM GETTING OUT OF THE 40S. LOW TO MID 50S EXPECTED WEST OF THE KETTLE MORAINE...WITH MID-UPR 50S FROM MADISON WEST...WITH A 60 OR TWO IN THE FAR SW. MODELS DEPICTING NICE BAND OF MAINLY ISENTROPICALLY-DRIVEN 700 MB OMEGA AND HIGHER RH CROSSING REGION AFTER 00Z SUNDAY...AND ARE PRODUCING SOME LIGHT QPF. BUT SIMILAR TO EARLIER THIS WEEK...CROSS SECTIONS AND FORECAST SOUNDINGS SHOWING RELATIVELY DRY EASTERLY FLOW PREVENTING SATURATION BELOW 7K-8K FEET THROUGH MOST OF THE NIGHT...WITH SOME SATURATION IN THE FAR WEST AFTER 06Z. WILL KEEP POPS NO HIGHER THAN THE CHANCE CATEGORY PRIOR TO 12Z EXCEPT FOR LOW LIKELY POPS IN THE EXTREME WEST AFTER 09Z. SUNDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM. THE OCCLUDED LOW PRESSURE SYSTEM WILL STALL OVER THE CENTRAL PLAINS UNTIL EARLY NEXT WEEK. THE 925MB WARM FRONT WILL BE STATIONED ACROSS NORTHERN IL ON SUNDAY...THEN CREEP NORTHWARD INTO FAR SOUTHERN WI THROUGH MONDAY NIGHT. MEANWHILE...THE 850MB WARM FRONT WILL REMAIN STATIONARY OVER CENTRAL WI. THE INITIAL WARM AIR ADVECTION SHOWERS ON SUNDAY WILL STRUGGLE TO OVERCOME THE LOW LEVEL DRY AIR IN PLACE. THE DEEP MOISTURE WILL FINALLY ARRIVE SUNDAY EVENING AS WAVES OF VORTICITY AND WARM AIR ADVECTION LEAD TO STRONG UPWARD MOTION OVER SOUTHERN WI. STEEP MID LEVEL LAPSE RATES AND THE STRONG OMEGA WILL ALLOW FOR EMBEDDED THUNDERSTORMS. MODERATE RAIN SHOWERS WITH PERIODS OF HEAVY RAIN WILL BE POSSIBLE SUNDAY NIGHT THROUGH MONDAY NIGHT. RAINFALL TOTALS DURING THIS TIME ARE ESTIMATED TO BE IN THE 1.3 TO 1.8 INCH RANGE WITH THE HIGHER TOTALS IN SW WI AND THE LOWER TOTALS OVER EAST CENTRAL WI. THIS RAIN AND THE ADDITIONAL EXPECTED NEXT WEEK WILL CAUSE MANY RIVERS TO REACH BANKFULL STAGE AND AT LEAST A FEW REACHING MINOR FLOOD STAGE. PLAN ON BREEZY EAST WINDS SUNDAY AND MONDAY WITH THE SURFACE LOW PARKED OVER NEBRASKA. THIS WILL KEEP TEMPERATURES VERY COOL IN THE UPPER 40S AND LOWER 50S. .LONG TERM... TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM. THE OCCLUDED LOW WILL MEANDER NORTHEAST OVER THE UPPER GREAT LAKES THROUGH THURSDAY. THE DRY SLOT IS EXPECTED TO ARRIVE INTO SOUTHERN WI SOMETIME TUESDAY OR TUESDAY NIGHT WHICH WOULD CUT OFF THE DEEP MOISTURE. CLOUDS AND SCATTERED SHOWERS WILL CONTINUE TO BE POSSIBLE THROUGH FRIDAY DUE TO THE CYCLONIC FLOW AND LINGERING LOW LEVEL MOISTURE. WINDS WILL GENERALLY BE OUT OF THE EAST FOR THE WEEK WHICH MEANS COOLER NEAR THE LAKE WITH HIGHS IN THE UPPER 40S THERE AND LOWER 50S INLAND. MODELS ARE SHOWING ANOTHER UPPER TROUGH SWINGING DOWN THROUGH WI FOR NEXT WEEKEND WHICH WOULD ALLOW FOR MORE CLOUDS AND SHOWERS. THERE IS STILL UNCERTAINTY IN TIMING...SO THERE MAY BE A PERIOD OF DRY WEATHER ON FRIDAY OR SATURDAY. && .AVIATION/12Z TAFS/... VFR CONDITIONS THROUGH THE PERIOD WITH RAIN EXPECTED TO HOLD OFF UNTIL AROUND/SHORTLY AFTER 12Z SUNDAY...THOUGH A FEW SPRINKLES POSSIBLER BEFORE...ESPECIALLY AT KMSN AND WEST. NORTH WINDS THIS MORNING BEHIND COLD FRONT WILL TURN NORTHEAST AND THEN EAST AS RIDGE OF SURFACE HIGH PRESSURE NOSES OVER STATE...THEN INCREASE LATER TONIGHT WITH TIGHTENING GRADIENT AS RIDGE SHIFTS OVER LOWER MICHIGAN AND DEEPENING LOW PRESSURE MOVES OUT INTO THE CENTRAL PLAINS. && .MARINE... LOOKING AT NORTH WINDS THIS MORNING TURNING NORTHEAST AND EAST AS RIDGE OF SURFACE HIGH PRESSURE NOSES DOWN OVER STATE AND LAKE MICHIGAN...THEN INCREASE LATER TONIGHT WITH TIGHTENING GRADIENT AS RIDGE SHIFTS OVER LOWER MICHIGAN AND DEEPENING LOW PRESSURE MOVES OUT INTO THE CENTRAL PLAINS. THE SOMETIMES GUSTY ONSHORE WINDS ARE EXPECTED TO PERSIST FROM SUNDAY INTO WEDNESDAY...AS THE LOW PRESSURE SLOWLY APPROACHES THE AREA. THESE WIND GUSTS WILL LIKELY REACH SMALL CRAFT CRITERIA AT TIMES....WITH WINDS JUST A FEW HUNDRED FEET OFF THE SURFACE REACHING 40 KTS. DO NOT FEEL THESE STRONGER WINDS WILL MIX DOWN THROUGH THE NEAR-WATER STABLE LAYER...BUT A FEW GALE GUSTS ARE NOT OUT OF THE QUESTION...ESPECIALLY SUNDAY NIGHT INTO MONDAY EVENING. THE ONSHORE WINDS SHOULD ALSO GENERATE WAVES IN THE 3 TO 6 FOOT RANGE. A SMALL CRAFT ADVISORY MAY BE NEEDED AT TIMES DURING THIS PERIOD. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...REM SUNDAY THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1050 PM MDT SUN APR 27 2014 .UPDATE... ISSUED AT 1050 PM MDT SUN APR 27 2014 UPDATED TO INCREASE POPS ACROSS THE CENTRAL MTS THROUGH THE OVERNIGHT. UPDATE ISSUED AT 856 PM MDT SUN APR 27 2014 UPDATED FOR LATEST OBS...SATELLITE AND RADAR TRENDS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 327 PM MDT SUN APR 27 2014 CURRENTLY...STRONG UPPER LEVEL AND SURFACE LOW PRESSURE STACKED OVER NORTHWESTERN KS WITH SOUTHERN END OF WRAP AROUND DEFORMATION PRECIP SLOWLY WEAKENING OVER SOUTHEAST CO. FARTHER WEST...LAPS SURFACE PRESSURE DATA SHOWS WEAK SECONDARY LOW PRESSURE NEAR KPUB...WHICH HAS CREATED LIGHTER WINDS OVER MUCH OF PUEBLO COUNTY THIS AFTERNOON...AND HAS IN GENERAL WEAKENED THE PRESSURE GRADIENT ACROSS SOUTHEAST COLORADO. WITH CONVECTION ENDING AND STRONG SURFACE GRADIENT LACKING...WIND SPEEDS HAVE BEGUN TO VERY SLOWLY DECREASE ACROSS THE PLAINS...AND STRONGEST GUSTS HAVE FALLEN BACK INTO THE 40- 45 KT RANGE. LATEST HRRR SUGGESTS WIND SPEEDS HAVE ALREADY PEAKED...AND GIVEN LACK OF OBSERVED 50 KT GUSTS...WILL CANCEL THE HIGH WIND WARNING FOR THE FAR SOUTHEAST. OVER THE MOUNTAINS...STILL SOME -SHSN OVER THE CONTINENTAL DIVIDE...THOUGH WEB CAMS SUGGEST LITTLE IN THE WAY OF ACCUMULATION OR LOW VISIBILITY...AT LEAST AT PASS LEVEL. TONIGHT...WILL KEEP SOME LOW POPS IN THE EVENING TO ACCOUNT FOR LINGERING -SHRA OVER THE SOUTHEAST PLAINS...WITH SOME HIGHER POPS FOR THE CENTRAL MOUNTAINS ALONG THE CONTINENTAL DIVIDE...WHERE SECONDARY UPPER WAVE WILL LIKELY HELP INCREASE -SHSN COVERAGE LATER TONIGHT. EXPECT WINDS TO GRADUALLY DIMINISH ALL AREAS THROUGH THE NIGHT...THOUGH MANY LOCATIONS WILL STAY BREEZY AS STRONG WINDS JUST OFF THE SURFACE PERSIST. EXPECTING ENOUGH IN THE WAY OF WINDS/CLOUDS TO KEEP PLAINS FROM A HARD FREEZE...THOUGH MOST MOUNTAINS AND HIGH VALLEYS WILL DROP INTO THE 20S OR COLDER. MONDAY...UPPER LOW VERY SLOWLY DRIFTS INTO ERN NEBRASKA DURING THE DAY...KEEPING STRONG NW FLOW AT THE SURFACE AND ALOFT ACROSS MOST OF SOUTHERN COLORADO. EXPECT WINDS TO INCREASE ALL AREAS BY MID MORNING...WITH GUSTS IN THE 30-40 KT RANGE MOST LOCATIONS BY AFTERNOON. GIVEN RATHER COLD AIR ALOFT/STEEP LAPSE RATES IN PLACE MON AFTERNOON...SUSPECT AT LEAST ISOLATED RAIN AND SNOW SHOWERS WILL DEVELOP OVER THE MOUNTAINS...WITH PERHAPS A FEW SPRINKLES/LIGHT SHOWERS OVER LOWER ELEVATIONS LATE IN THE DAY. LOW LEVELS WILL BE FAIRLY DRY...WHICH WILL KEEP PRECIP AMOUNTS LIGHT. MAX TEMPS WILL REMAIN COOL...WITH BLENDED NUMERICAL GUIDANCE LOOKING OK FOR HIGHS. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 327 PM MDT SUN APR 27 2014 VERY UNSETTLED PATTERN QUEUED UP FOR THE FORECAST AREA THROUGH THE EXTENDED FORECAST...BUT MODELS ARE LEANING TOWARDS TWO SEPARATE PERIODS OF WEATHER TYPES. MONDAY NIGHT THROUGH THURSDAY...LONG RANGE MODELS INDICATE THAT THE UPPER LOW PRESSURE SYSTEM WILL PINWHEEL ABOUT THE US CENTRAL PLAINS AND UPPER MISSISSIPPI RIVER VALLEY THROUGH THU...BEFORE FINALLY EJECTING TO THE NE ACROSS THE GREAT LAKES. THIS SOLUTION WILL KEEP VERY BRISK AND COOL NORTHERLY FLOW IN PLACE FOR THE STATE INTO THU...AS WELL AS A DAILY SHOT OF SHOWER ACTIVITY FOR THE CWA. AS THE LOW LINGERS...LOBES OF ENERGY WILL ROTATE AROUND THE SYSTEM AND BRING PERIODICALLY BETTER CHANCES FOR SHOWERS...THOUGH THE EXACT TIMING OF THESE WINDOWS IS NEAR IMPOSSIBLE TO PREDICT AT THIS TIME. LOOK FOR MAX TEMPS EACH DAY IN THE 50S TO AROUND 60 F FOR THE LOWER ELEVATIONS...AND 30S TO 40S FOR THE MTS. THE HIGHER TERRAIN IS EXPECTED TO EXPERIENCE ISOLATED TO LOW END SCATTERED POPS THROUGH THU...WITH THE BEST SHOT OF SOME ISOLATED CONVECTION FOR THE PLAINS COMING TUE AFTN...AND AGAIN WED AFTN AND EVE. FRIDAY THROUGH SUNDAY...THE GFS AND EC MODELS HINT THAT BY FRI THE UPPER LOW WILL FINALLY BE PULLING AWAY FROM THE REGION...ALLOWING THE UPPER FLOW TO SHIFT TO A MORE WESTERLY DIRECTION INTO THE WEEKEND. BOTH MODELS DO CONTINUE TO SHOW MEAGER SHOWER ACTIVITY BOTH FRI AND SAT...MAINLY TIED TO THE HIGHER TERRAIN...BUT FEEL THAT THIS FAR OUT THIS MAY BE A BIT OVERDONE. BY SUNDAY PCPN SHOULD COME TO AN END. LOOK FOR A WARMING TREND INTO THE WEEKEND AS THE UPPER FLOW SHIFTS...WITH MAX TEMPS IN THE 60S FOR FRI...THEN 70S FOR BOTH SAT AND SUN. MOORE && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1050 PM MDT SUN APR 27 2014 MODERATE TO STRONG NORTH TO NORTHWEST FLOW ALOFT WILL PERSIST ACROSS THE STATE THROUGH THE MIDDLE OF THE WORK WEEK. THIS WILL KEEP BREEZY TO WINDY CONDITIONS ACROSS THE AREA FROM THE LATE MORNINGS THROUGH THE LATE EVENING HOURS. WITH THAT SAID...VFR CONDITIONS EXPECTED AT ALS...COS AND PUB OVER THE NEXT 24 HOURS. SHOULD SEE GUSTY NORTH TO NORTHWEST WIND OF 20-35KT DEVELOPING AT TAF SITES AFT 16Z AND DIMINISH AFT 02Z. COULD SEE ISOLATED SHOWERS ACROSS THE HIGHER TERRAIN AFT 18Z...THOUGH DOES NOT LOOK TO AFFECT TAFS ATTM. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MW SHORT TERM...PETERSEN LONG TERM...MOORE AVIATION...MW
AREA FORECAST DISCUSSION
NWS ALBANY NY
444 AM EDT MON APR 28 2014 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 445 AM EDT...PATCHY CLOUDS ACROSS PORTIONS OF THE WESTERN ADIRONDACKS...AND THE UPPER HUDSON VALLEY REGION ARE FINALLY BEGINNING TO ERODE. WE EXPECT THESE CLOUDS TO CONTINUE TO DECREASE IN AREAL COVERAGE THROUGH SUNRISE...ALLOWING TEMPS TO FALL SEVERAL MORE DEGREES IN MOST AREAS. AFTER DAYBREAK...WE EXPECT MOSTLY SUNNY SKIES TO START THE DAY. HOWEVER...ADDITIONAL PATCHES OF CLOUDS ARE EXPECTED TO APPROACH FROM THE NORTHEAST LATER TODAY...AFFECTING MAINLY SOUTHERN VT...NORTHERN MA...AND POSSIBLY THE UPPER HUDSON RIVER VALLEY. IN ADDITION...HIGHER CLOUDS WILL BEGIN TO APPROACH SOUTHERN AND WESTERN AREAS LATE THIS AFTERNOON. THE CLOUDS ACROSS NORTHEAST AREAS WILL BE THE RESULT OF SOME RESIDUAL MOISTURE ROTATING AROUND THE WESTERN PERIPHERY OF THE STORM SYSTEM WELL OFF THE NEW ENGLAND COAST. SOME OF THE HI-RES MODELS...INCLUDING THE HRRR AND THE OPERATIONAL NAM WRF HINT AT SOME LIGHT SHOWERS OR SPRINKLES POSSIBLY AFFECTING SOME HIGHER ELEVATIONS OF SOUTHERN VT BY EVENING. WILL INDICATE SOME SLIGHT CHC POPS FOR ISOLATED SHOWERS/SPRINKLES IN THIS REGION TO ACCOUNT FOR THIS REMOTE POSSIBILITY. DEEP MIXING TODAY TO AROUND 825 MB SHOULD ALLOW TEMPS TO REACH 60-65 IN MOST VALLEY AREAS...AND 55-60 ACROSS HIGHER ELEVATIONS TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... TONIGHT...A DEVELOPING EASTERLY LOW LEVEL FLOW WILL INITIALLY ENHANCE LOW LEVEL MOISTURE AND LOW CLOUD POTENTIAL ACROSS THE REGION LATER TONIGHT. THIS IS PARTICULARLY SUGGESTED BY THE RUC-13 AND NAM...AS WELL AS THE REGIONAL GEM. IN ADDITION...HIGH CLOUDS WILL CONTINUE TO INCREASE FROM THE SOUTH AND WEST. SO...WILL INDICATE PARTLY TO MOSTLY CLOUDY SKIES OVERNIGHT...WITH CLOUDS BECOMING MOST WIDESPREAD AFTER MIDNIGHT. WILL ALSO KEEP SLIGHT CHC POPS ACROSS PORTIONS OF SOUTHERN VT/NORTHWEST MA FOR SOME ISOLATED SHOWERS OR SPRINKLES...ESP THIS EVENING. WILL ALSO SIDE ON THE MILDER SIDE OF GUIDANCE...WITH GENERALLY 40-45 EXPECTED IN VALLEYS...AND 35-40 ACROSS HIGHER TERRAIN. TUESDAY...THE MID LEVEL RIDGE AXIS WILL SLOWLY MOVE EAST OF THE REGION DURING THE DAY...ALLOWING DEEPER MOISTURE TO BEGIN TO OVERSPREAD THE REGION FROM SOUTHWEST TO NORTHEAST. HOWEVER...IT APPEARS THAT FOR AREAS NEAR AND E OF THE HUDSON RIVER VALLEY...MOST OF THE MORNING HOURS SHOULD REMAIN DRY. WILL LIMIT POPS IN THESE AREAS FOR THE AFTERNOON HOURS...MAINLY IN THE CHC RANGE. TO THE W...WILL INDICATE MAINLY CHC POPS IN THE MORNING...AND BOOST TO LIKELY IN THE AFTERNOON. MOST OF THE RAIN SHOULD BE LIGHT...AS IT WILL ENCOUNTER INITIALLY DRY LOW/MID LEVEL AIR AND MID LEVEL SUBSIDENCE. TEMPS WILL BE SOMEWHAT TRICKY...AS ANY DELAY IN RAINFALL WILL ALLOW FOR WARMER MAX TEMPS. WILL SIDE ON THE WARMER SIDE OF GUIDANCE ACROSS THE UPPER HUDSON RIVER VALLEY AND SOUTHERN VT...WHERE THE RAIN SHOULD DEVELOP LATEST...AND THE POSSIBILITY FOR SOME THIN SPOTS ON THE OVERCAST WILL BE GREATEST. IN ADDITION...SOME ENHANCED DOWNSLOPING WITH THE INCREASING E/SE LOW LEVEL FLOW MAY HELP BOOST TEMPS FURTHER IN THESE AREAS...WHICH COULD REACH AROUND 60. ELSEWHERE...EXPECT MAX TEMPS TO REACH THE MID/UPPER 50S IN VALLEYS FROM ALBANY N...W AND NORTHEAST...AND 50-55 TO THE SOUTH AND WEST WHERE CLOUDS...RAIN...AND A COOLER MARINE MODIFIED AIR MASS SHOULD KEEP TEMPS COOLER. TUE NT-WED...ALTHOUGH IT APPEARS UNSETTLED DURING THIS PERIOD...IT LOOKS LIKE IT WON/T BE A COMPLETE WASHOUT...AS POCKETS OF SYNOPTIC LIFT MOVE ACROSS THE REGION. HOWEVER...THE GREATEST FORCING AND LOW LEVEL MOISTURE CONVERGENCE WILL REMAIN MAINLY SOUTH AND WEST OF THE REGION. SO...EXPECT SEVERAL ROUNDS OF SHOWERS AND/OR PERIODS OF RAINFALL...BUT THERE COULD EASILY BE SOME PERIODS WHERE ONLY SOME SPRINKLES OR PATCHY DRIZZLE OCCUR. AS A WEDGE OF DRIER AIR ADVECTS WESTWARD AROUND THE SOUTHERN PERIPHERY OF THE VERY STRONG HIGH TO OUR N...THERE IS ACTUALLY SOME POTENTIAL FOR SLEET TO MIX IN WITH ANY SHOWERS ACROSS HIGHER ELEVATIONS OF THE SOUTHERN ADIRONDACKS AND WESTERN NEW ENGLAND LATE TUE NT/EARLY WED AM. TEMPS WILL COOL INTO THE MID 30S TO LOWER 40S TUE NT...AND SHOULD ONLY REACH THE MID 40S TO LOWER 50S ON WED. IN FACT...SHOULD RAINFALL BE MORE PERSISTENT/STEADIER ON WED...EVEN COOLER MAX TEMPS COULD OCCUR...WITH MOST AREAS REMAINING BELOW 50. WINDS WILL ALSO INCREASE DURING THIS PERIOD AS THE LOW LEVEL PRESSURE GRADIENT TIGHTENS BETWEEN THE AFOREMENTIONED STRONG EASTERN CANADIAN HIGH...AND LOW PRESSURE APPROACHING FROM THE SOUTH AND WEST. EAST/SOUTHEAST WINDS WILL BECOME QUITE GUSTY AT TIMES...WITH SOME GUSTS OF 30-40 MPH POSSIBLE AT TIMES BY WED AFTN...PARTICULARLY ACROSS HIGHER ELEVATIONS OF THE TACONICS...SOUTHERN GREEN MTNS...AND NORTHERN BERKSHIRES...AS WELL AS ACROSS PORTIONS OF THE WESTERN ADIRONDACKS...MOHAWK VALLEY AND CATSKILLS. WED NT...THE BEST FORCING FROM THE COMBINATION OF ISENTROPIC LIFT...MOISTURE TRANSPORT AND LOW LEVEL JET DYNAMICS APPEARS TO BE DURING THIS PERIOD...LEADING TO WIDESPREAD SHOWERS OR A STEADY RAIN. SOME OF THE RAIN COULD BE HEAVY AT TIMES. IT WILL ALSO INITIALLY REMAIN WINDY...ESP THROUGH MIDNIGHT...WHERE SOME GUSTS INTO THE 35-45 MPH RANGE COULD OCCUR IN PORTIONS OF THE SOUTHERN GREENS AND NORTHERN BERKSHIRES. IT APPEARS THAT A WIDESPREAD 1-2 INCHES OF RAINFALL SHOULD OCCUR THROUGH DAYBREAK THU...WITH GREATER AMTS POSSIBLE ACROSS PORTIONS OF THE SE CATSKILLS...MID HUDSON VALLEY...AND NW CT. OVERNIGHT MINS SHOULD MAINLY BE IN THE UPPER 30S TO MID 40S. && .LONG TERM /THURSDAY THROUGH SUNDAY/... MORE UNSETTLED WEATHER IS EXPECTED TO LAST THROUGH THE UPCOMING WEEKEND. A VERTICALLY STACKED CUTOFF LOW WILL SIT AND SPIN OVER THE GREAT LAKES REGION AS PIECES OF ENERGY ROTATE AROUND IT ACROSS THE NORTHEAST. THIS WILL KEEP AT LEAST SCATTERED SHOWERS ACROSS OUR REGION THURSDAY THROUGH SUNDAY. WHILE IT WILL NOT BE RAINING ALL OF THE TIME THERE WILL BE PERIODS WHERE THE SHOWERS WILL BE MORE NUMEROUS WHICH WILL BE ON THURSDAY INTO FRIDAY. RAINFALL AMOUNTS ON THURSDAY THROUGH THURSDAY NIGHT WILL GENERALLY BE A THIRD OF AN INCH TO THREE QUARTERS OF AN INCH. EXPECT HIGHS ON THURSDAY TO RANGE FROM THE UPPER 50S AND LOWER 60S NORTHWEST TO LOWER 70S SOUTHEAST. LOWS THURSDAY NIGHT WILL BE IN THE UPPER 30S TO UPPER 40S AND HIGHS ON FRIDAY WILL BE IN THE MID 50S TO MID 60S. THE UPPER LEVEL TROUGH WILL EXPAND EASTWARD TOWARDS THE NORTHEAST FOR FRIDAY NIGHT INTO THE WEEKEND...AND START TO WEAKEN SOMEWHAT. AS A RESULT...WE WILL STILL SEE THE OPPORTUNITY FOR SHOWERS EACH DAY...MAINLY TIED TO DIURNAL HEATING AND TIMING OF WEAK VORTICITY MAXES ROTATING AROUND THE UPPER LEVEL LOW. EXPECT LOWS FRIDAY NIGHT TO RANGE FROM THE UPPER 30S NORTHWEST TO THE MID 40S SOUTHEAST WITH HIGHS ON SATURDAY IN THE MID 50S TO MID 60S. LOWS ON SATURDAY NIGHT ARE EXPECTED TO RANGE FROM THE MID 30S NORTHWEST TO THE MID 40S SOUTHEAST. THERE IS THE POSSIBILITY OF A LITTLE SNOW ACROSS THE SOUTHERN ADIRONDACKS LATE SATURDAY NIGHT. HIGHS ON SUNDAY WILL BE IN THE MID 50S TO LOWER 60S. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... VFR CONDITIONS ARE EXPECTED AT ALL THE TAF SITES THROUGH THE END OF THE TAF PERIOD ENDING AT 06Z TUESDAY. DURING THE OVERNIGHT HOURS EXPECT SCT-BKN STRATOCU CLOUDS OVER THE AREA. THESE CLOUDS WILL DISSIPATE BY DAYBREAK AT MOST SITES ALTHOUGH IT MAY TAKE A LITTLE LONGER AT KALB AS THE CLOUD AREAS IS SHRINKING FROM THE EAST AND WEST...SO KALB WILL LIKELY BE THE LAST TO LOSE THE CLOUD DECK WHICH WILL BE AT 4-6 KFT OVERNIGHT. N-NE WINDS WL AVG 4-6 KTS OVERNIGHT. DURING THE DAY ON MONDAY...N-NW WINDS WILL BE ABOUT 5-10 KTS WITH SCT DIURNAL CU AT 4-6 KFT DEVELOPING DURING THE DAY. THERE WILL BE SOME PASSING CIRRUS CLOUDS AS WELL...BUT NO PRECIPITATION IS EXPECTED DUE TO HIGH PRESSURE NEARBY...AND VFR CONDITIONS WILL CONTINUE. THE CIRRUS CLOUDS WILL BECOME THICKER BY EVENING. OUTLOOK... TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA. WEDNESDAY: HIGH OPERATIONAL IMPACT.WINDY WITH GUSTS TO 31.0 LIKELY SHRA. WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. OCNL SHRA. THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA. THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. && .FIRE WEATHER... ...RH VALUES WILL FALL INTO THE 25-30 PERCENT RANGE THIS AFTERNOON... HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY...ALONG WITH A WETTING RAINFALL. THE RH WILL FALL INTO THE 25-35 PERCENT RANGE FOR MOST AREAS THIS AFTERNOON...LOWEST IN VALLEY AREAS. THE RH WILL THEN RECOVER TO 80-95 PERCENT TONIGHT...THEN FALL INTO THE 30-40 PERCENT RANGE FOR NORTHERN AREAS...AND 40-60 PERCENT RANGE FOR SOUTHERN AND WESTERN AREAS TUESDAY AFTERNOON. NORTHWEST WINDS AT 5-10 MPH THIS MORNING WILL BECOME NORTH TO NORTHEAST AND INCREASE TO 5-15 MPH THIS AFTERNOON...WITH SOME GUSTS POSSIBLY REACHING UP TO 20 MPH AT TIMES ACROSS PORTIONS OF THE UPPER HUDSON RIVER VALLEY. WINDS WILL VEER INTO THE EAST TONIGHT AT 5-15 MPH...THEN BECOME E TO SE ON TUESDAY AND INCREASE TO 10-20 MPH...WITH SOME GUSTS OF 20-30 MPH POSSIBLE IN THE AFTERNOON...ESP ACROSS PORTIONS OF SOUTHERN VT. A WETTING RAINFALL IS EXPECTED FOR LATE TUESDAY THROUGH THURSDAY. && .HYDROLOGY... NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED THROUGH EARLY IN THE WEEK. EXPECTING DRY WEATHER THROUGH TONIGHT AS HIGH PRESSURE DOMINATES. WET WEATHER WILL RETURN FOR MID WEEK AS A LARGE SLOW MOVING LOW PRESSURE SYSTEM TO OUR WEST IMPACTS THE REGION. THIS SYSTEM HAS THE POTENTIAL TO PRODUCE SOME HEAVY RAIN. HOWEVER THERE IS UNCERTAINTY IN THE POTENTIAL QPF AMOUNTS. AT THIS TIME...IT APPEARS THAT THE POTENTIAL FOR A WIDESPREAD 1-2 INCHES OF RAINFALL IS INCREASING...WITH SOME LOCALLY HIGHER AMTS POSSIBLE...PARTICULARLY ACROSS PORTIONS OF THE SE CATSKILLS...MID HUDSON VALLEY...AND NW CT. THIS SHOULD CAUSE SIGNIFICANT WITHIN BANK RISES ON MOST RIVERS...WITH THE POSSIBILITY OF SOME REACHING ACTION STAGE...ESPECIALLY IN THE HOUSATONIC BASIN...AND POSSIBLY ACROSS PORTIONS OF THE CATSKILLS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...KL/IAA/FRUGIS NEAR TERM...KL SHORT TERM...KL LONG TERM...FRUGIS/11 AVIATION...FRUGIS/11 FIRE WEATHER...KL/IAA HYDROLOGY...KL/IAA
AREA FORECAST DISCUSSION
NWS JACKSON KY
152 AM EDT MON APR 28 2014 .UPDATE... ISSUED AT 151 AM EDT MON APR 28 2014 CURRENTLY ACROSS EASTERN KENTUCKY...A LINE OF SHOWERS HAS MOVED NORTHEAST THROUGH THE AREA ALONG THE WARM FRONT. BEHIND THIS...ANOTHER LINE OF SHOWERS IS STARTING TO DEVELOP AS IT SLIDES EAST AND EAST NORTHEAST THROUGH THE AREA. IT SEEMS A BIT MORE INSTABILITY IS PRESENT WITH THIS AND UPSTREAM IN TN...SOME INDICATION OF MORE MOIST AND UNSTABLE AIR IS STARTING TO STREAM NORTH. WITH ALL THIS IN MIND...HAVE UPDATED THE FORECAST AND SENT OUT A ZFP TO BRING IN POPS A BIT EARLIER AND BRING LIKELY POPS IN BY THE MORNING AS THE ANTICIPATED FIRST WAVE BEHINDS TO PUSH NORTHEAST. UPDATE ISSUED AT 1030 PM EDT SUN APR 27 2014 AS EXPECTED...EARLIER THUNDERSTORMS HAVE WEAKENED WITH JUST SOME WIDELY ISOLATED SHOWERS PUSHING ACROSS THE AREA WITH THE WARM FRONT. THIS ACTIVITY WILL CONTINUE TO PUSH NORTHWARD OVER THE NEXT 3 TO 5 HOURS...WITH DRIER WEATHER RETURNING THROUGH THE LATTER HALF OF THE NIGHT. HOWEVER...PLENTY OF SHOWERS AND THUNDERSTORMS UPSTREAM ACROSS ARKANSAS AND FAR WESTERN KENTUCKY. SOME OF THIS MAY CONGEAL INTO AN MCS AND TRACK TOWARDS THE AREA TOMORROW MORNING. THIS COULD BRING THE THREAT OF DAMP WEATHER BACK TO THE AREA AROUND OR SHORTLY AFTER DAYBREAK. AT THIS TIME...IT DOES NOT APPEAR THIS ACTIVITY WILL POSE A SEVERE RISK AS SURFACE INSTABILITY WILL BE AT A MINIMUM EARLY IN THE MORNING. IT LOOKING MORE LIKE WE MAY HAVE MORE OF A SEVERE THREAT ARRIVING MONDAY EVENING OR MONDAY NIGHT AS WE MAY SEE AN MCS MOVE INTO THE AREA INTO THE OVERNIGHT TIME PERIOD. THUS...SEVERE THREAT APPEARS TO BE PUSHED BACK INTO MONDAY EVENING OR MONDAY NIGHT. UPDATE ISSUED AT 745 PM EDT SUN APR 27 2014 A FEW SHOWERS AND STORMS BEGINNING TO ENCROACH UPON EASTERN KENTUCKY. THE FIRST ONE IS JUST GRAZING THE WESTERN EDGE OF WAYNE COUNTY AS IT MOVES NORTHWARD...WITH A SECONDARY AREA MOVING INTO SOUTHERN BELL/WHITLEY COUNTIES. NOT MUCH OTHER ACTIVITY ON RADAR AT PRESENT TIME. WITH MORE OF A STRATIFORM LIGHT RAIN DEVELOPING FARTHER TO THE SOUTHWEST ACROSS NORTH CENTRAL TENNESSEE. STILL PLENTY OF DRY AIR IN PLACE ACROSS EASTERN KENTUCKY WHICH WILL LIKELY PUT THE END TO ANY STORM CHANCES AS STUFF TRIES TO PUSH INTO THE AREA. THUS...WITH SUN SETTING...WE WILL BE LOSING ANY INSTABILITY WE HAVE OUT THERE WITH THUNDERSTORMS DIMINISHING TOWARDS SHOWERS. EVEN THE SHOWERS WILL HAVE A TOUGH TIME SURVIVING AS THEY MOVE INTO THE DRIER AIR IN THE EAST. THUS...HAVE BACKED OFF POPS THIS EVENING INTO THE OVERNIGHT HOURS. ALSO BACKED OFF THUNDER CHANCES AFTER THE NEXT HOUR OR SO. NEXT ROUND OF SHOWERS AND THUNDERSTORMS REMAIN OUT ACROSS WESTERN TENNESSEE AND WESTERN KENTUCKY AND IF IT HOLDS TOGETHER...WOULD NOT BE INTO THE AREA UNTIL AFTER MIDNIGHT. UPDATED FORECAST IS ALREADY OUT. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 355 PM EDT SUN APR 27 2014 STARTING INTO AN ACTIVE PERIOD DURING THE SHORT TERM. A SURFACE LOW PRESSURE SYSTEM WILL REMAIN OVER THE CENTRAL PLAINS THIS EVENING...WHILE SEVERAL WAVES OF ENERGY WILL CONTINUE TO ROTATE AROUND THIS SYSTEM. EASTERN KY WILL REMAIN IN THE WARM SECTOR...WITH A WARM FRONT POSITIONED ACROSS MUCH OF THE STATE. MEANWHILE...WESTERN AND CENTRAL KY WILL FIND THEMSELVES POSITIONED BETWEEN THE WARM FRONT AND COLD FRONT...WITH WARM UNSTABLE AIR CONTINUING TO FILTER IN AND ABUNDANT MOISTURE TO ACCOMPANY. WHILE NOT MUCH PROGRESSION IS EXPECTED THIS AFTERNOON OR TONIGHT IN TERMS OF THE SURFACE LOW AND THE ASSOCIATED FRONTS...THE INCREASED INSTABILITY DURING THE AFTERNOON WILL WORK TO HELP ANY CONVECTIVE DEVELOPMENT TO SPREAD EASTWARD SLOWLY. LATEST HIRES MODELS...INCLUDING THE NAM12/HRRR/AND ECMWF ALL POINT AT PRECIP ENTERING INTO EASTERN KY BETWEEN 0 AND 6Z AND THEN CONTINUING EASTWARD THROUGHOUT THE NIGHT. IT IS ALSO AROUND THIS POINT THAT GFS40 AND NAM12 FORECAST SOUNDINGS SHOW SOME IMPRESSIVE LOW LEVEL SHEER IN PORTIONS OF EASTERN KY. WHILE LINGERING DRY LOW LEVEL AIR AND SE DOWNSLOPE WINDS COULD WORK TO HOLD OFF SOME PRECIP IN THE EVENING...EXPECT THAT ISOLATED TO SCATTERED SHOWERS WILL DEVELOP. IN DOING SO...MOISTENING OF THE LOW LEVELS WILL BE ENOUGH TO ALLOW UNSTABLE AIR TO RISE AND THUNDERSTORMS TO DEVELOP. IN ADDITION...BASED ON STRONG STORMS THAT HAVE DEVELOPED UPSTREAM...HAVE KEPT THUNDER AS THE PREDOMINATE WX TYPE THIS EVENING AND THROUGH THE NIGHT. BETWEEN 3Z AND 12Z MONDAY...CHANCE POPS WILL OVERSPREAD THE AREA. HOWEVER...LATEST HI-RES GUIDANCE IS POINTING AT A DRY POCKET DEVELOPING AS DOWNSLOPE FLOW INCREASES SLIGHTLY ACROSS THE SOUTHEAST PORTION OF THE STATE. LATEST RUC13 OMEGA IS ALSO SUPPORTIVE OF THIS IDEA...SHOWING DOWNWARD MOTION ACROSS THE SE PORTION OF THE STATE BY 9Z. THE QUESTION THEN WILL BE...HOW MUCH WILL THIS DOWNSLOPING INHIBIT ANY STORM DEVELOPMENT? HOW FAR INTO EASTERN KY COULD IT POTENTIALLY INHIBIT STORM GROWTH AND RAIN...AND WILL WE STILL EXPECT SOME ISOLATED TO SCATTERED CHANCES...OR WILL DOWNSLOPE CUT OFF POTENTIAL ALL TOGETHER? UNFORTUNATELY...THESE ARE ALL QUESTIONS WHICH CAN/T REALLY BE ANSWERED UNTIL THE MAIN CONVECTION REACHES OUR AREA. UNTIL THEN...WILL TRY TO PLAY ON THIS THINKING...AND TREND DOWN POPS SLIGHTLY FOR THE SE PORTION OF THE CWA. DURING THE DAY TOMORROW...SURFACE LOW WILL HAVE PROGRESSED ONLY SLIGHTLY EASTWARD...THOUGH THE SURFACE COLD FRONT WILL HAVE ENTERED INTO THE MISSISSIPPI VALLEY REGION. WITH THE FORCING SO GREAT IN PROXIMITY TO THIS FRONT...AND A STRONG PULL OF GULF MOISTURE...EXPECT SHOWERS/TSRA TO OVERCOME THE DOWNSLOPING PULL. ESPECIALLY IF WINDS SHIFT MORE SOUTHERLY FOR A PERIOD OF TIME...COULD SEE MORE WIDESPREAD DEVELOPMENT ACROSS THIS AREA. UNFORTUNATELY...EVEN THE HI-RES MODELS ARE SHOWING SOME DISAGREEMENT ON THE EXTENT AND MAGNITUDE OF PRECIP FOR TOMORROW...SO HAVE TRIED TO STICK TO A BLEND. Q VECTORS ARE SHOWING THE BEST AREAS FOR UPWARD MOTION AND STORM DEVELOPMENT REMAINING JUST TO OUR NORTH TOMORROW...MAINLY OVER THE UPPER GREAT LAKES REGION. SOME DECENT CONVERGENCE DOES MAKE IT INTO KY AS WELL...MOVING FROM WEST TO EAST ACROSS THE STATE. AS IT HEADS INTO EASTERN KY...EVEN THE QVECTOR CONVERGENCE PICKS UP ON A BRIEF LULL IN ACTIVITY ACROSS THE SE PORTION OF THE STATE WITH DOWNSLOPE WINDS IN PLACE. THIS QUICKLY DISAPPEARS AS THE BEST CONVERGENCE MOVES OVER THE REGION...SO FURTHER SUPPORT THAT AT SOME POINT THE MOISTURE WILL BE ENOUGH TO OVERCOME ANY EFFECTS FROM THE WIND DIRECTION. LOW LEVEL WIND SHEAR DURING THE DAY TOMORROW ISN/T QUITE AS IMPRESSIVE AS THAT EXPECTED THIS EVENING...BUT IT SEEMS TO BE A BIT DEEPER. WINDS IN THE UPPER LEVELS ARE QUITE STRONG...SO EXPECT A GOOD DRIVING FORCE AND THE POTENTIAL FOR A LINE OF SHOWERS/STORMS TO TRAVERSE KY /AS WAS REFLECTED IN THE MONDAY EVENING/MONDAY NIGHT POPS AND WEATHER/. MONDAY NIGHT/S LINE OF STORMS IS ALSO EXPECTED TO BRING THE BEST THREAT FOR HEAVY PRECIP DURING THE SHORT TERM ACCORDING TO THE LAST FEW MODEL RUNS. AFTER ROUND ONE OF PRECIP MOVES IN TONIGHT AND TOMORROW...A STRONGER SECOND LINE WILL DEVELOP CLOSER TO THE FRONT. MOISTURE GETTING PULLED IN WILL ALLOW FOR 6 HOUR QPF AMOUNTS WELL IN THE 1 TO 3 INCH RANGE BY 6Z TUESDAY...TRAVERSING EASTERN KY DURING THIS TIME. WITH THIS AMOUNT OF EXPECTED CONVECTIVE RAIN...AND THE CONTINUED POTENTIAL FOR SOME THUNDERSTORMS PRODUCING HEAVY SHOWERS OVER SMALL AREAS...THERE DOES LIE THE THREAT OF FLOODING ACROSS PORTIONS OF THE STATE...INCLUDING EASTERN KY. WINDS ALOFT ARE QUITE IMPRESSIVE AS THIS LINE MOVES OVER...SO ANY STORMS OR HEAVY RAIN SHOWERS BRING THE THREAT OF TRANSFERRING SOME OF THESE POTENTIALLY DAMAGING WINDS TO THE GROUND. AS FAR AS THE FLOODING...WILL PROBABLY NEED TO ISSUE A WATCH AT SOME POINT IN THE NEAR FUTURE. ELECTED NOT TO DURING THE DAY SHIFT JUST FOR THE SHEER FACT THAT THE MODELS ARE STILL HAVING A HARD TIME AGREEING...AND REALLY ITS GOING TO BE A MATTER OF HOW MUCH PRECIP WE END UP RECEIVING OVERNIGHT TONIGHT AND TOMORROW MORNING TO KNOW HOW SATURATED THE SOIL WILL BE LEADING INTO THE EVENING. WILL MENTION CONCERNS TO INCOMING SHIFT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 425 PM EDT SUN APR 27 2014 THE MODELS CONTINUE TO BE IN GOOD AGREEMENT ALOFT WITH THE LARGE AND LUMBERING CLOSED LOW OVER THE MID SECTION OF THE NATION AT THE START OF THE EXTENDED. THIS DOMINANT FEATURE ROLLS OVER ON ITSELF AS IT SLOWLY FILLS AND LIFTS NORTH INTO THE UPPER MIDWEST AND WESTERN GREAT LAKES BY 00Z THURSDAY. THE SYSTEM BECOMES MORE PROGRESSIVE TOWARD THE END OF THE WEEK...EVENTUALLY EXITING INTO EASTERN CANADA. BEFORE IT DOES SO...A CONTINUATION OF A SERIES OF MID LEVEL ENERGY PACKETS WILL PLOW THROUGH KENTUCKY BRINGING PERIODIC SUPPORT TO CONVECTION THROUGHOUT THE REGION. FOR TUESDAY...A KEY ONE OF THESE PACKETS MOVES OVER EAST KENTUCKY EARLY FOLLOWED BY ANOTHER LATE IN THE DAY AND INTO EARLY WEDNESDAY. THESE PACKETS DO WEAKEN WITH TIME SO THAT THE VERSION THAT GOES THROUGH ON MIDDAY WEDNESDAY WILL LIKELY NOT PACK THE PUNCH OF THE EARLIER ONES. FALLING HEIGHTS LOCALLY WILL BE NOTED INTO THURSDAY MORNING EVEN AS THE MAIN LOW TO THE NORTH WEAKENS BUT BY THIS TIME THE ENERGY SWIRLING PAST WILL BE SIMILARLY WEAKER. IT IS ALSO ABOUT THIS TIME THAT THE AGREEMENT OF THE GEM WITH THE NEARLY LOCKSTEP ECMWF AND GFS AT MID LEVELS FADES AND ITS SOLUTION IS SUBSEQUENTLY DISCOUNTED. THE OTHER MODELS CONTINUE TO MAINTAIN LOWER THAN NORMAL 500MB HEIGHTS OVER EAST KENTUCKY INTO THE WEEKEND DUE TO THE ARRIVAL OF ANOTHER...MORE PROGRESSIVE AND OPEN...TROUGH FROM THE PLAINS. THE GFS IS A BIT BETTER CONSOLIDATED WITH THIS THAN THE ECMWF AS IT TAKES ITS AXIS THROUGH EAST KENTUCKY EARLY SATURDAY WHILE THE ECMWF SNEAKS A LEAD WAVE THROUGH ON FRIDAY WITH THE REST OF THE SYSTEM PASSING THROUGH LATER SATURDAY. HEIGHTS WILL THEN TICK UP IN THE WAKE OF THIS ACTION TO CLOSE OUT THE WEEKEND ON A WELCOMED QUIETER NOTE. FOR THE FORECAST HAVE FOLLOWED A GENERAL MODEL BLEND THROUGH THE REST OF THE WORK WEEK WITH A SLIGHT PREFERENCE FOR THE LATEST ECMWF THEREAFTER. SENSIBLE WEATHER WILL FEATURE AT LEAST ONE LAST STORMY DAY AND NIGHT TO START THE EXTENDED. THE EXPECTATION IS THAT AN ONGOING CLUSTER OF STORMS WILL BE MOVING OUT OF EASTERN KENTUCKY AT 12Z TUESDAY. HOWEVER...THE NEXT SURGE OF LIFT ASSOCIATED WITH THE MID LEVEL WAVE ROLLING INTO THE AREA LATER THAT DAY WILL START TO ACT ON THE ENVIRONMENT OF EAST KENTUCKY DURING THE AFTERNOON. THIS WILL COMBINE WITH THE MOIST BOUNDARY LAYER...HEATING THROUGH THE DAY...TO GENERATE DECENT INSTABILITY LIKELY KICKING OFF ANOTHER CONVECTIVE CLUSTER. WITH THE VEERING SHEAR PROFILE AND POTENTIAL FOR HIGHER INSTABILITY BY EVENING TUESDAY...WILL CONTINUE THE THREAT OF STRONG TO SEVERE STORMS. THESE STORMS MAY LINGER INTO THE NIGHT BEFORE CLEARING OUT TO THE EAST ALONG WITH THE SYSTEM/S SLOW MOVING COLD FRONT FINALLY PUSHING OUT OF THE AREA. THE NEARBY FRONT AND LOW MID LEVEL HEIGHTS SHOULD LEAVE WEDNESDAY WITH A POTENTIAL FOR RENEWED CONVECTION...THOUGH THE THUNDER THREAT WILL PROBABLY BE LIMITED TO THE FAR EAST AND MAINLY EARLIER IN THE DAY. THE THREAT OF SHOWERS WILL THEN CONTINUE THROUGH THE REST OF THE WORK WEEK AND INTO THE FIRST PART OF THE WEEKEND WHILE LIMITED INSTABILITY AND COOLER TEMPERATURES KEEP THE THREAT OF THUNDER TO A MINIMUM. HAVE GONE WITH DRY WEATHER FOR SUNDAY AS HIGH PRESSURE SHOULD BE MOVING OVERHEAD. TEMPERATURES WILL BE DEFINITELY ON THE COOL SIDE OF NORMAL FOR THE BULK OF THE EXTENDED IN THE WAKE OF THE SYSTEM/S SLOW MOVING COLD FRONT PASSING THROUGH ON WEDNESDAY. TUESDAY REMAINS THE MOST CHALLENGING DAY FOR MAX TEMPERATURES DUE TO QUESTIONS OF CLEARING BEHIND THE DEPARTING EARLY MORNING BATCH OF CONVECTION. MORE...AND QUICKER...CLEARING WILL ALLOW TEMPERATURES TO SOAR INTO THE UPPER 70S AND ALSO SPIKE THE INSTABILITY MAKING FOR A BETTER POTENTIAL FOR SEVERE WEATHER. HOWEVER...THERE IS A POTENTIAL FOR CONVECTIVE DEBRIS AND LINGERING LOW CLOUDS/SHOWERS TO KEEP TEMPERATURES CAPPED AND INSTABILITY/SVR POTENTIAL MORE LIMITED. THE CR GRID LOAD CAME IN PRETTY GOOD FOR THE BULK OF THE EXTENDED... THOUGH DID MAKE SOME ADJUSTMENTS TOWARD THE LATEST ECMWF SOLUTION FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND...PARTICULARLY FOR A DRY SUNDAY. DID ALSO FINE TUNE SOME LOW TEMP GRIDS LATER IN THE FORECAST TO ALLOW FOR SOME ENHANCED RIDGE AND VALLEY DETAIL OVER THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 151 AM EDT MON APR 28 2014 VFR CONDITIONS WILL BEGIN THE TAF PERIOD THROUGH THE LATE TONIGHT HOURS. BY THE MORNING...SHOWERS AND THUNDERSTORMS WILL BEGIN TO MOVE INTO THE WESTERN CWA WITH A LINE PUSHING THROUGH THE TAF SITES AND HAVE PUT IN SOME MVFR CONDITIONS THROUGH THE 12Z TO 16Z RANGE MAINLY DUE TO VISIBILITY IN THE SLIGHTLY HEAVIER SHOWERS. WILL THEN SHOW SOME VFR TOMORROW AFTERNOON BEFORE THE NEXT STRONG TO SEVERE LINE OF SHOWERS AND STORMS MOVE IN BY THE LAST 6 HOURS OF THE TAF PERIOD AND HAVE GONE IFR DURING THIS PERIOD. WINDS WILL BE OUT OF THE SOUTH FOR MUCH OF THE PERIOD WITH GUSTS UP TO 20 KNOT OUTSIDE OF THUNDERSTORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SHALLENBERGER SHORT TERM...JMW LONG TERM...GREIF AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1155 PM CDT SUN APR 27 2014 .DISCUSSION... FOR 06Z TAFS...IFR CONDITIONS STARTING TO MOVE INTO WESTERN AREA...WILL STAY THAT WAY THROUGH THE OVERNIGHT HOURS. MVFR ELSEWHERE IS EXPECTED THROUGH THE MORNING. STILL NOT CERTAIN ON HOW MUCH...IF ANY PRECIP WILL OCCUR AT SOUTHERN TAF SITES SO STILL HOLDING OFF ON MENTIONING IT...BUT MAY NEED TO BE ADDED FOR THE MORNING HOURS. WILL BE CARRYING A TEMPO GROUP FOR THUNDERSTORMS AT KAEX IN THE MORNING HOURS. && .PREV DISCUSSION... /ISSUED 943 PM CDT SUN APR 27 2014/ DISCUSSION... UPDATED THE AREAL DISTRIBUTION OF POPS TO MORE CLOSELY FOLLOW THE HRR (HIGH RESOLUTION RAPID REFRESH) SOLUTION. OTHERWISE...THE ZONE PACKAGE IS ON TARGET. JT PREV DISCUSSION... /ISSUED 630 PM CDT SUN APR 27 2014/ DISCUSSION... FOR 00Z TAFS...VFR TO MVFR CONDITIONS EXPECTED THIS EVENING...WITH GUSTY SOUTH WINDS. NOT EXPECTING THE NEXT ROUND OF PRECIP UNTIL TOWARDS DAYBREAK...BUT LOW CONFIDENCE ON COVERAGE AT THIS POINT. PREV DISCUSSION... /ISSUED 436 PM CDT SUN APR 27 2014/ DISCUSSION... LATEST WATER VAPOR SATELLITE IMAGERY SHOWED A VIGOROUS UPPER LOW OVER NW KS/SW NE...WITH A VIGOROUS PACIFIC JET NOSING IN FROM THE PAC NW AND CURLING CYCLONICALLY THROUGH THE BASE OF THE LOW. A SUBTROPICAL JET WAS NOTED TO THE SOUTH ACROSS CENTRAL MX INTO THE WRN GULF. KLCH AND KPOE VWPS CONTINUE TO SHOW A 50KT PLUS SOUTHWESTERLY LLJ. AT THE SFC...LOW PRESSURE IS HARD TO MISS OVER NW KS...WITH A TRAILING CDFNT/DRYLINE THROUGH CENTRAL OK/TX. HARD TO HAVE A GREAT DEAL OF FAITH IN ANY SPECIFIC SHORT TERM GUIDANCE...AS PRECIOUS FEW CAUGHT THE ISOLATED TO SCATTERED ELEVATED CONVECTION THAT DEVELOPED THIS AFTERNOON. THE ONLINE SPC 4KM WRF WASNT TOO BAD...AND THE HRRR DID FINALLY CATCH ON. THESE TWO MODELS...WITH SOME ADDITIONAL SUPPORT FROM GLOBAL MODELS...DEPICT A BAND OF CONVECTION INITIATING AFTER MIDNIGHT IN THE VICINITY OF EAST CENTRAL TEXAS NE TWD SHREVEPORT. THE SOUTHWESTWARD EXTENT OF ANY SUCH DEVELOPMENT IS A BIT UNCERTAIN...BUT IT IS NOT OUT OF THE QUESTION FOR NORTHERN ZONES TO BE AFFECTED GIVEN THE THE PROJECTED EAST/NORTHEAST MOVEMENT. WILL MAINTAIN HIGHEST POPS TONIGHT IN THIS AREA...AND HOLD ONTO THE SEVERE WORDING. GENERALLY PRESERVED THE INHERITED INLAND WIND HAZARDS...BUT DID TWEAK THE MARINE HAZARDS A BIT...EASING OUT OF THE SCA FOR THE COASTAL LAKES AND BAYS MID EVENING...AND THE INLAND WATERS WEST OF CAMERON AFTER MIDNIGHT CONCURRENT WITH LATEST PROGS THAT SHOW WINDS STARTING TO DECREASE FROM WEST TO EAST OVERNIGHT AND INTO TOMORROW. A WIND ADVISORY MAY STILL BE WARRANTED FOR A TIME ACROSS SOUTH/EAST CENTRAL LOUISIANA...BUT WILL LET THE OVERNIGHT CREW MAKE THE CALL ON THAT AS IT LOOKS A LITTLE MORE MARGINAL. CONVECTIVE PROSPECTS WILL ALSO SHIFT EAST TOMORROW...AS THE CDFNT PUSHES JUST EAST OF A KSHV TO KLFK LINE BY TOMORROW AFTERNOON. HAVE GENERALLY LEFT THIS PART OF THE FORECAST AS IS...STAYING MAINLY WITH LOW TO MID RANGE POPS AND PRESERVING THE SEVERE WORDING PER SPC DAY 2 CONVECTIVE OUTLOOK. THE FRONT IS STILL FCST TO PUSH THROUGH THE DURING THE AFTERNOON AND EVENING HOURS ON TUE...WITH THE SEVERE RISK DISPLACED TO OUR EAST BY THIS TIME. ALTHOUGH STILL NOT IN IDEAL AGREEMENT...THE GFS HAS COME A LONG WAY TOWARD THE ECMWF SOLUTION IN DEPICTING SOUTHWESTERLY FLOW ALOFT...WITH ONE OR MORE FRONTAL WAVES/LOWS DEVELOPING ALONG THE FRONT. APPEARS THAT THE BEST CHANCE OF ANY RAIN AFFECTING THE AREA WOULD BE THU NIGHT-FRI...AS BOTH MODELS DEPICTING A SHORTWAVE TROF PIVOTING THROUGH THE NW GULF COAST REGION. MARINE... GUSTY SOUTH WINDS AND ROUGH SEAS WILL CONTINUE THIS EVENING AS A LOW PRESSURE SYSTEM DEVELOPS IN THE PLAINS. WINDS WILL BEGIN TO DIMINISH A BIT OVER THE COASTAL LAKES AND BAYS TONIGHT AND THE WATERS WEST OF CAMERON LATE TONIGHT INTO TOMORROW. TIDES WILL BE RUNNING ABOUT ONE FOOT ABOVE NORMAL TODAY AND MONDAY. THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL ALSO CONTINUE INTO EARLY NEXT WEEK AS THIS LOW PRESSURE SYSTEM SLOWLY MOVES EAST THROUGH THE CENTRAL UNTIED STATES...CULMINATING IN A FRONT CROSSING THE REGION TUESDAY NIGHT. OFFSHORE FLOW WILL PREVAIL IN THE WAKE OF THE FRONT FOR THE REST OF THE WORK WEEK. && .PRELIMINARY POINT TEMPS/POPS... KLCH 72 84 70 85 57 / 20 30 20 20 20 KBPT 72 84 69 85 58 / 20 20 20 20 10 KAEX 71 85 67 83 53 / 50 50 30 30 10 KLFT 72 84 71 85 58 / 30 40 40 30 30 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: ACADIA...CALCASIEU...EAST CAMERON...IBERIA... JEFFERSON DAVIS...LAFAYETTE...LOWER ST. MARTIN...ST. MARY... UPPER ST. MARTIN...VERMILION...WEST CAMERON. TX...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: JEFFERSON...ORANGE. GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM...WATERS FROM INTRACOASTAL CITY TO CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON LA TO HIGH ISLAND TX FROM 20 TO 60 NM...WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM. SMALL CRAFT EXERCISE CAUTION UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: CALCASIEU LAKE...SABINE LAKE. SMALL CRAFT EXERCISE CAUTION UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING ZONES: VERMILION BAY. SMALL CRAFT ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM. SMALL CRAFT EXERCISE CAUTION UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM. && FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.LAKECHARLES.GOV WWW.TWITTER.COM/NWSLAKECHARLES WWW.YOUTUBE.COM/NWSLAKECHARLES && $$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1250 AM EDT MON APR 28 2014 .SYNOPSIS... LOW PRESSURE SOUTH OF NOVA SCOTIA WILL CONTINUE MOVING INTO THE OPEN ATLANTIC TONIGHT INTO MONDAY. HIGH PRESSURE WILL BUILD SOUTH ACROSS THE REGION MONDAY NIGHT THROUGH WEDNESDAY. && .NEAR TERM /THROUGH TODAY/... 1250 AM UPDATE...STARTING TO SEE SHOWERS DEVELOPING OVER WESTERN/SOUTHERN NEW BRUNSWICK. THIS ACTIVITY WILL CONTINUE TO MOVE WESTWARD AROUND THE TOP OF THE DEPARTING UPPER LOW. THIS INFLUX OF MOISTURE HAS PROHIBITED TEMPERATURES FROM DROPPING VERY MUCH TONIGHT; MOST AREAS ARE STILL IN THE UPPER 30S TO LOWER 40S. FOR THIS UPDATE, ADJUSTED POPS UP A BIT, ESPECIALLY OVER WASHINGTON COUNTY AS PER RADAR TRENDS. ALSO RAISED OVERNIGHT LOWS BY A DEGREE OR TWO ACROSS THE NORTH. NO OTHER CHANGES WERE NEEDED. PREVIOUS DISCUSSION... THE CHALLENGE WILL DEFINITELY BE THE TEMPERATURES AND WHERE TO PLACE RAINFALL CHANCES. LOW PRES WAS SPINNING SE OF NOVA SCOTIA PER THE 18Z ANALYSIS. SFC TROUGH EXTENDING OFF THIS LOW EXTENDED BACK EASTERN AND CENTRAL MAINE. THE FIRST BATCH OF LIGHT RAIN/SHOWERS MOVED SSW EARLY TODAY AND ANOTHER ROUND IS APPROACHING FROM NEW BRUNSWICK. THE RAIN HAS BEEN WEAKENING AS IT RUNS INTO DRIER AIR AS SEEN BY THE LATEST SATELLITE VISIBLE IMAGERY SHOWING BREAKS IN THE CLOUDS. BEST SUPPORT FOR SUBSTANTIAL RAIN HAS BEEN OVER THE EASTERN SECTIONS OF WASHINGTON COUNTY. DECENT LLVL CONVERGENCE AND MID LEVEL FORCING IS THERE AS SEEN BY BOTH THE RAP AND NAM12. EXPECTING THIS TREND TO CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON. CARRIED CHANCE POPS(30-50%) FOR THE CWA TONIGHT W/THE HIGHEST CHANCES ACROSS NORTHERN AND EASTERN SECTIONS. AS ONE TRAVELS FURTHER W AND SW, SHOWERS WILL WEAKEN DUE TO SUBSIDENCE IN PLACE. CLOUDS WILL HANG AROUND THROUGHOUT THE NIGHT AND THIS WILL KEEP TEMPERATURES WELL ABOVE 32F WHICH SHOULD ALLOW FOR ALL LIQUID PRECIP. RAINFALL AMOUNTS HAVE BEEN LIGHT AND SEE NO SUPPORT FOR THIS TO CHANGE MUCH OVER THE NEXT 24 HRS. THEREFORE, STAYED W/QPF OF 0.10" OR LESS THROUGH MONDAY. CONDITIONS LOOK TO IMPROVE THROUGHOUT THE DAY ON MONDAY AS HIGH PRES IS FORECAST TO WEDGE DOWN FROM CANADA. SOME SUNSHINE IS EXPECTED BY MONDAY AFTERNOON ESPECIALLY ACROSS THE NORTHERN AND EASTERN SECTIONS WHILE THE CENTRAL HIGHLANDS WILL HANG ON TO MORE CLOUDS. THIS WILL LEAD TO A VARIATION IN TEMPERATURES. DECIDED TO BOOST DAYTIME HIGHS ON MONDAY UP TO READINGS AOA 50F MAINLY FOR THE NORTHERN AND EASTERN SECTIONS. CENTRAL AND WESTERN AREAS WILL HANG W/MORE CLOUDS THUS KEEPING TEMPERATURES DOWN INTO THE 40S SOMEWHAT SIMILAR TO TODAY. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY/... HIGH PRESSURE WILL RIDGE SOUTH ACROSS THE REGION MONDAY NIGHT THROUGH EARLY WEDNESDAY...THEN BEGIN TO MOVE EAST LATER WEDNESDAY. CLOUD COVER WILL DECREASE ACROSS THE REGION MONDAY NIGHT. MOSTLY CLEAR SKIES WILL OCCUR ACROSS THE REGION TUESDAY INTO EARLY WEDNESDAY. CLOUD COVER WILL THEN BEGIN TO INCREASE LATER WEDNESDAY...PARTICULARLY ACROSS WESTERN PORTIONS OF THE FORECAST AREA. TEMPERATURES WILL BE AT NEAR NORMAL...TO SLIGHTLY BELOW NORMAL...LEVELS TUESDAY/WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AN UNSETTLED PATTERN WILL TAKE HOLD ONCE AGAIN FOR THE LONG RANGE AS THE RIDGE BREAKS DOWN AND THE NEXT UPPER LEVEL LOW ADVANCES TOWARD THE REGION. CLOUDS WILL INCREASE WEDNESDAY NIGHT WITH RAIN AND SHOWERS DEVELOPING WEST TO EAST FOR THURSDAY AS AN OCCLUSION MOVES THROUGH AHEAD OF A SURFACE LOW ADVANCING NORTH ALONG THE COAST. STEADIER RAIN LOOKS TO TAPER OFF THURSDAY NIGHT WITH RAIN AMOUNTS OF A HALF INCH TO AN INCH POSSIBLE BY THIS TIME. EXPECT SHOWERS TO LINGER INTO FRIDAY IN ASSOCIATION WITH THE BROAD UPPER LEVEL LOW SITUATED OVER THE GREAT LAKES BY THIS TIME AND A LINGERING SURFACE TROUGH. SOME UNCERTAINTY DEVELOPS IN THE FORECAST FOR THE BEGINNING OF NEXT WEEKEND. OVERALL, THE UNSETTLED PATTERN REMAINS HOWEVER THE ECMWF MODEL BRINGS A BRIEF WINDOW OF SOME PARTIAL CLEARING AND DRYING IN FOR SATURDAY WHILE THE GFS SUGGESTS MORE CLOUDS WITH AT LEAST A FEW LINGERING SHOWERS. AT THIS POINT WILL KEEP IN THE CHANCE OF SHOWERS WITH MOSTLY CLOUDY SKIES. A BETTER CHANCE FOR MORE WIDESPREAD RAIN AND SHOWERS DEVELOPS ONCE AGAIN FOR SATURDAY NIGHT AND SUNDAY AS THE NEXT SURFACE WAVE ASSOCIATED WITH THE BROAD UPPER TROUGH DEVELOPS SOUTH OF THE REGION AND MOVES NORTH UP THE COAST. TEMPERATURES THROUGH THE LONG RANGE ARE FORECAST TO REMAIN WITHIN A FEW DEGREES OF AVERAGE FOR THIS TIME OF YEAR. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... NEAR TERM: VFR AT ALL THE TERMINALS AS OF 01Z. EXPECTATION IS FOR CIGS TO DROP TO MVFR ACROSS ALL THE TERMINALS OVERNIGHT. A PERIOD OF IFR IS POSSIBLE LATE TONIGHT(AFT 08Z) AND THIS WILL MAINLY BE FOR THE NORTHERN TERMINALS. DECIDED TO STAY W/MVFR THROUGH MIDDAY MONDAY. AN IMPROVEMENT TO VFR IS EXPECTED BY MON EVENING. SHORT TERM: VFR CONDITIONS ARE EXPECTED ACROSS THE REGION MONDAY NIGHT THROUGH WEDNESDAY. VFR WEDNESDAY NIGHT WILL GIVE WAY TO MVFR AND THEN IFR THURSDAY AS RAIN MOVES IN FROM WEST TO EAST. MVFR/IFR CONDITIONS ARE LIKELY TO PERSIST INTO FRIDAY DUE TO LOW STRATUS WITH LINGERING SHOWERS. && .MARINE... NEAR TERM: NO SCA ATTM. LATEST MODEL GUIDANCE HAS BEEN RUNNING TOO HIGH FOR THE WINDS AND ADJUSTMENTS WERE MADE TO PUSH THE SPEEDS BACK. THE WIND WILL GRADUALLY INCREASE OVER THE NEXT 24 HOURS AND THE SEAS WILL SLOWLY BUILD. A SCA MAY BE NEEDED BY LATE MONDAY. SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE ON THE WATERS MONDAY NIGHT INTO EARLY TUESDAY NIGHT. CONDITIONS ARE EXPECTED TO BE BELOW SMALL CRAFT ADVISORY LEVELS LATER TUESDAY NIGHT INTO WEDNESDAY. SCA CONDITIONS WILL BE POSSIBLE THURSDAY AS SE WINDS STRENGTHEN AND WAVE HEIGHTS INCREASE AHEAD OF AN OCCLUSION MOVING THROUGH WHICH WILL ALSO BRING RAIN AND THE POTENTIAL FOR FOG. THESE CONDITIONS IMPROVE FOR FRIDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HASTINGS/HEWITT SHORT TERM...NORCROSS LONG TERM...FITZSIMMONS AVIATION...HASTINGS/HEWITT/NORCROSS MARINE...HASTINGS/HEWITT/NORCROSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
513 AM EDT MON APR 28 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 511 AM EDT MON APR 28 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER LEVEL TROUGH FROM THE NW CONUS THROUGH THE CENTRAL PLAINS WITH A CLOSED LOW OVER NEBRASKA. DOWNSTREAM A RIDGE EXTENDED FROM THE SE CONUS THROUGH WRN LAKES INTO MANITOBA. AT THE SFC...A BRISK ERLY FLOW PREVAILED THROUGH THE NRN LAKES BETWEEN HIGH PRES OVER HUDSON BAY AND A DEEP LOW OVER ERN NEBRASKA. ISENTROPIC ASCENT AS NOTED ON THE 295K SFC HAS PRODUCED SEVERAL BANDS OF LIGHT PCPN OVER UPPER MI THIS MORNING BUT THIS PCPN HAS FALLEN MAINLY AS JUST SPRINKLES/FLURRIES AS IT ENCOUNTERS VERY DRY AIR BELOW 750 MB. TODAY...MODELS CONSISTENT SHOWING SYSTEM OVER ERN NEBRASKA STALLING AND BEGINNING TO OCCLUDE TODAY. MODELS SHOW WEAKENING ISENTROPIC ASCENT OVER UPR MI AND A LACK OF 850-700 MB MOISTURE ADVECTION INTO THE REGION. THIS FACT ALONG WITH MID-LVL RDG GENERALLY STAYING IN PLACE SHOULD KEEP MUCH OF THE CWA DRY TODAY. INCREASING 850-700 MB MOISTURE ADV AND ISENTROPIC ASCENT COULD BRING IN A BETTER CHC OF RAIN TOWARD 00Z THIS EVENING OVER MAINLY FAR SCNTRL CWA. TONIGHT...MODELS SHOW MORE SUBSTANTIAL SHORTWAVE LOBE ROTATING NORTHWARD AHEAD OF PLAINS CLOSED LOW WHICH IN TURN WILL PROPEL 850 MB WARM FRONT NORTHWARD INTO THE SE CWA LATE TONIGHT. INCREASING ISENTROPIC ASCENT AND 850-700 MB MOISTURE ADVECTION SPREADING IN FROM THE SSE AHEAD OF THE WARM FRONT WILL BRING INCREASING RAIN CHCS INTO SCNTRL CWA THIS EVENING SPREADING INTO THE REST OF THE SE HALF OF THE CWA OVERNIGHT TONIGHT. THICKNESS VALUES AND SOUNDINGS SUGGEST SNOW MAY MIX WITH RAIN OVER NCNTRL AND NW CWA LATE TONIGHT BUT PCPN SHOULD BE LIGHT THAT ANY SNOW AMTS WILL HAVE LITTLE IMPACT ON TRAVEL. MODEL QPF INDICATES SCNTRL CWA COULD SEE FROM .25 TO PERHAPS .75 OF AN INCH OF RAINFALL TONIGHT WHICH WILL ADD TO RUNOFF FOR AREA STREAMS AND RIVERS INTO MIDWEEK. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 358 AM EDT MON APR 28 2014 FOCUSED ATTENTION ON TUE-WED NIGHT TIME FRAME AS MOST SIGNIFICANT PRECIP IS EXPECTED DURING THAT TIME. THE SETUP FOR MID WEEK IS QUITE INTERESTING ACROSS THE CONUS AS A DEEP CLOSED UPPER LOW IS OVER THE CENTRAL CONUS...BORDERED ON THE W...N AND E BY AMPLIFIED UPPER RIDGING. ALSO...AT THE START OF THE LONG TERM /12 TUE/...THE UPPER LOW WILL BE ABSORBING A WEAK UPPER LOW THAT ORIGINATED OVER QUEBEC. THE SYSTEM WILL BE QUITE WRAPPED UP...WITH GREAT MOISTURE TRANSPORT FROM BOTH THE GULF OF MEXICO AND THE ATLANTIC THAT FOCUSES OVER THE LOWER GREAT LAKES BEFORE WRAPPING W ACROSS THE CWA AND EVENTUALLY TO THE W OF THE LOW /WHICH IS OVER IA AT 12Z TUE/. PRECIP TUE WILL BE PRIMARILY FORCED BY 50-60KT 900-700MB WINDS...RESULTING IN GOOD MOISTURE TRANSPORT IN THIS LAYER AS WELL AS STRONG ISENTROPIC ASCENT AS ISENTROPIC SURFACES INCREASE IN HEIGHT BY AROUND 1KM FROM UPSTREAM TO DOWNSTREAM ACROSS THE CWA. PWAT VALUES WILL BE 0.75-1.00 INCHES...OR GENERALLY 150-200 PERCENT OF NORMAL. ANOTHER SIGNIFICANT FORCING MECHANISM IS A SHORTWAVE THAT MODELS SHOW MOVING ACROSS THE CWA TUE...WHICH LEADS TO STEEP 700-500MB LAPSE RATES OF JUST OVER 7C/KM. ADDITIONALLY...THE LEFT EXIT REGION OF AN UPPER JET WILL BE ACROSS THE CWA. ALL THESE INGREDIENTS COME TOGETHER TO PRODUCE SIGNIFICANT QPF AMOUNTS FROM THE MODELS LATE MON NIGHT INTO TUE. THE MOST PRECIP SHOULD FALL NEAR LAKE MICHIGAN WHERE THE BEST FORCING AND MOISTURE IS EXPECTED. EVEN THE LOWER RES MODELS /THAT TYPICALLY DO NOT PERFORM AS WELL IN THIS TYPE OF SITUATION/ HAVE UP TO AN INCH OF QPF NEAR LAKE MICHIGAN...WHILE THE NAM HAS THE MOST QPF AT 2.25 INCHES. WILL GO WITH A CONSENSUS APPROACH OF GFS/ECMWF AND REGIONAL GEM /WHICH HAS UP TO 1.85 INCHES/...WHICH INCORPORATES MON NIGHT /SHORT TERM/. THE ECMWF/GFS HAVE THE BEST PRECIP LATE MON NIGHT INTO TUE MORNING...WHILE THE NAM HAS THE BEST PRECIP ON TUE. THE REGIONAL GEM IS BETWEEN THE NAM AND GFS/ECMWF. A COMPLICATING FACTOR TO THIS TIME FRAME IS THAT MODEL TEMP PROFILES FAVOR PRECIP TO BE SNOW OVER WRN UPPER MI AND RAIN NEAR LAKE MICHIGAN AND E...WITH A MIX BETWEEN. DUE TO SFC TEMPS BEING NEAR OR ABOVE FREEZING AND STRONG SOLAR EFFECTS THIS TIME OF YEAR...ACCUMULATIONS ON PAVED SURFACES SHOULD BE MINIMAL...BUT GRASSY SURFACES OVER THE HIGHER TERRAIN OF WRN UPPER MI COULD SEE 2-3 INCHES OF SNOW. GIVEN VERY MINIMAL EXPECTED IMPACTS TO TRAVEL...WILL CONTINUE TO NOT MENTION SNOW IN THE HWO. DEPENDING ON EXACT PRECIP AMOUNTS...COULD SEE SOME SIGNIFICANT RISES ON AREA RIVERS. ANOTHER SHOT AT GOOD ISENTROPIC ASCENT AND A STRONG SHORTWAVE ARE SHOWN BY MODELS FOR WED AS THE UPPER LOW CONTINUES TO WEAKEN AND BEGINS MOVING NE TOWARD THE CWA. SIGNALS FOR PRECIP AMOUNTS AND TRENDS ARE A LOT MORE MUDDLED ON WED INTO WED NIGHT AS THE CWA WILL BE MORE REMOVED FROM THE BEST MOISTURE TRANSPORT...WHICH WILL BE MORE FOCUSED E AND N OF THE CWA. THINK THAT MUCH OF THE CWA WILL SEE PRECIP...WITH POTENTIAL FOR UP TO AN INCH OF ADDITIONAL PRECIP DURING THIS TIME PERIOD. USED A BROAD CONSENSUS OF GUIDANCE DURING THIS PERIOD. THE UPPER LOW WILL CONTINUE TO WEAKEN AND MOVE SLOWLY NE INTO LATE WEEK BEFORE ADDITIONAL UPPER LEVEL ENERGY MOVES INTO THE REGION LATE THIS WEEK INTO THE WEEKEND...LEADING TO CONTINUED WET WEATHER...BUT AMOUNTS WILL BE LOWER THROUGH THE REST OF THE WEEK. USED A CONSENSUS OF GUIDANCE FOR THIS PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 129 AM EDT MON APR 28 2014 VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD UNDER MID CLOUDS. E-NE WINDS COULD GUST NEAR 25 KT AT ALL TAF SITES AS PRES GRADIENT TIGHTENS AHEAD OF LOW PRES OVER THE CENTRAL PLAINS. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 511 AM EDT MON APR 28 2014 EAST TO NORTHEAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE DEEPENS OVER THE PLAINS. EXPECT ENE GALES TO 35KTS OVER MUCH OF WRN LAKE SUPERIOR INTO TUE MORNING. THERE IS ALSO A CHANCE FOR ENE GALES TO 35 KNOTS OVER CENTRAL LAKE SUPERIOR FOR LATE TONIGHT INTO TUE SO HAVE ISSUED A GALE WATCH FOR LSZ264-266 WINDS SHOULD GRADUALLY DIMINISH LATE TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE EVENING. WINDS ARE EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED INTO FRI AS THE LOW FILLS AND REMAINS NEAR UPPER MICHIGAN. && .HYDROLOGY... ISSUED AT 358 AM EDT MON APR 28 2014 RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER NEAR NAHMA JUNCTION. AT LEAST THROUGH TONIGHT THESE RIVERS ARE NOT EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS WILL START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF HIGHER QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK. REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR LSZ264>266. GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ TUESDAY FOR LSZ162-263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...TITUS AVIATION...07/JV MARINE...VOSS HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 AM EDT MON APR 28 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 432 PM EDT SUN APR 27 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER LEVEL TROUGH THROUGH THE NW CONUS WITH A LOW OVER WRN KS AND A DOWNSTREAM RIDGE FROM THE SE CONUS THROUGH WRN LAKES INTO MANITOBA. AT THE SFC...A BRISK ERLY FLOW PREVAILED THROUGH THE NRN LAKES BETWEEN HIGH PRES OVER HUDSON BAY AND A DEEP LOW OVER NW KS. AN INITIAL BAND OF LIGHT PCPN WAS PRODUCING MAINLY JUST SPRINKLES INTO THE FAR WRN CWA NEAR IWD AS IT ENCOUNTERS THE VERY DRY LAYER BELOW 750 MB. HOWEVER...A MORE SUBSTANTIAL AREA OF RAIN OVER WRN INTO N CNTRL WI...SUPPORTED BY 300K ISENTROPIC LIFT WAS LIFTING TOWARD UPPER MI. TONIGHT...RADAR TRENDS AND SHORT TERM MODELS SUGGEST THAT SOME LIGHT SHOWERS WILL MOVE INTO THE WEST LATE THIS AFTERNOON AND EVENING. HOWEVER...THERE IS A LOWER CHANCE THAT THERE WILL BE MEASURABLE PCPN GIVEN THE AMOUNT OF DRY AIR TO OVERCOME WITH THE ERLY LOW LEVEL INFLOW. FARTHER TO THE EAST...OVER S CNTRL UPPER MI...THE DRY AIR...PER 12Z APX SOUNDING...SHOULD BE MORE EFFECTIVE AT SLOWING THE ADVANCE AND REDUCING PCPN CHANCES. WITH EVAPORATIVE COOLING AT THE LEADING EDGE OF THE PCPN...SOME SNOW OR SLEET MAY ALSO MIX IN WITH THE RAIN LATE THIS EVENING AND OVERNIGHT...PER NAM LOW LEVEL THICKNESS AND WET-BULB ZERO HEIGHTS. MON...THE MODELS WERE IN SLIGHTLY BETTER AGREEMENT IN HANDLING THE ADVANCE OF PCPN INTO UPPER MICHIGAN. THE NAM/GFS/ECMWF WERE NOW ON THE SLOWER SIDE COMPARED TO GEM. AS THE MID/UPPER LEVEL LOW SLOWLY WOBBLES TO THE NORTHEAST AND AN ELONGATED TROUGH/FRONT EXTENDS FROM SRN IA INTO NRN INDIANA. ANOTHER BAND OF RAIN WILL MOVE TOWARD UPPER MI WITH INCREASING 300K-305K ISENTROPIC ASCENT NORTH OF THE 850 MB WARM FRONT THROUGH CNTRL WI. THERE IS STILL LIKELY TO BE SHARP CUTOFF TO THE NRN EDGE OF THE PCPN BAND THROUGH CNTRL UPPER MI. THE HIGHEST CHANCES WILL REMAIN ALONG THE WI BORDER WITH ONLY A SLIGHT CHANCE OVER THE NORTH. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 358 AM EDT MON APR 28 2014 FOCUSED ATTENTION ON TUE-WED NIGHT TIME FRAME AS MOST SIGNIFICANT PRECIP IS EXPECTED DURING THAT TIME. THE SETUP FOR MID WEEK IS QUITE INTERESTING ACROSS THE CONUS AS A DEEP CLOSED UPPER LOW IS OVER THE CENTRAL CONUS...BORDERED ON THE W...N AND E BY AMPLIFIED UPPER RIDGING. ALSO...AT THE START OF THE LONG TERM /12 TUE/...THE UPPER LOW WILL BE ABSORBING A WEAK UPPER LOW THAT ORIGINATED OVER QUEBEC. THE SYSTEM WILL BE QUITE WRAPPED UP...WITH GREAT MOISTURE TRANSPORT FROM BOTH THE GULF OF MEXICO AND THE ATLANTIC THAT FOCUSES OVER THE LOWER GREAT LAKES BEFORE WRAPPING W ACROSS THE CWA AND EVENTUALLY TO THE W OF THE LOW /WHICH IS OVER IA AT 12Z TUE/. PRECIP TUE WILL BE PRIMARILY FORCED BY 50-60KT 900-700MB WINDS...RESULTING IN GOOD MOISTURE TRANSPORT IN THIS LAYER AS WELL AS STRONG ISENTROPIC ASCENT AS ISENTROPIC SURFACES INCREASE IN HEIGHT BY AROUND 1KM FROM UPSTREAM TO DOWNSTREAM ACROSS THE CWA. PWAT VALUES WILL BE 0.75-1.00 INCHES...OR GENERALLY 150-200 PERCENT OF NORMAL. ANOTHER SIGNIFICANT FORCING MECHANISM IS A SHORTWAVE THAT MODELS SHOW MOVING ACROSS THE CWA TUE...WHICH LEADS TO STEEP 700-500MB LAPSE RATES OF JUST OVER 7C/KM. ADDITIONALLY...THE LEFT EXIT REGION OF AN UPPER JET WILL BE ACROSS THE CWA. ALL THESE INGREDIENTS COME TOGETHER TO PRODUCE SIGNIFICANT QPF AMOUNTS FROM THE MODELS LATE MON NIGHT INTO TUE. THE MOST PRECIP SHOULD FALL NEAR LAKE MICHIGAN WHERE THE BEST FORCING AND MOISTURE IS EXPECTED. EVEN THE LOWER RES MODELS /THAT TYPICALLY DO NOT PERFORM AS WELL IN THIS TYPE OF SITUATION/ HAVE UP TO AN INCH OF QPF NEAR LAKE MICHIGAN...WHILE THE NAM HAS THE MOST QPF AT 2.25 INCHES. WILL GO WITH A CONSENSUS APPROACH OF GFS/ECMWF AND REGIONAL GEM /WHICH HAS UP TO 1.85 INCHES/...WHICH INCORPORATES MON NIGHT /SHORT TERM/. THE ECMWF/GFS HAVE THE BEST PRECIP LATE MON NIGHT INTO TUE MORNING...WHILE THE NAM HAS THE BEST PRECIP ON TUE. THE REGIONAL GEM IS BETWEEN THE NAM AND GFS/ECMWF. A COMPLICATING FACTOR TO THIS TIME FRAME IS THAT MODEL TEMP PROFILES FAVOR PRECIP TO BE SNOW OVER WRN UPPER MI AND RAIN NEAR LAKE MICHIGAN AND E...WITH A MIX BETWEEN. DUE TO SFC TEMPS BEING NEAR OR ABOVE FREEZING AND STRONG SOLAR EFFECTS THIS TIME OF YEAR...ACCUMULATIONS ON PAVED SURFACES SHOULD BE MINIMAL...BUT GRASSY SURFACES OVER THE HIGHER TERRAIN OF WRN UPPER MI COULD SEE 2-3 INCHES OF SNOW. GIVEN VERY MINIMAL EXPECTED IMPACTS TO TRAVEL...WILL CONTINUE TO NOT MENTION SNOW IN THE HWO. DEPENDING ON EXACT PRECIP AMOUNTS...COULD SEE SOME SIGNIFICANT RISES ON AREA RIVERS. ANOTHER SHOT AT GOOD ISENTROPIC ASCENT AND A STRONG SHORTWAVE ARE SHOWN BY MODELS FOR WED AS THE UPPER LOW CONTINUES TO WEAKEN AND BEGINS MOVING NE TOWARD THE CWA. SIGNALS FOR PRECIP AMOUNTS AND TRENDS ARE A LOT MORE MUDDLED ON WED INTO WED NIGHT AS THE CWA WILL BE MORE REMOVED FROM THE BEST MOISTURE TRANSPORT...WHICH WILL BE MORE FOCUSED E AND N OF THE CWA. THINK THAT MUCH OF THE CWA WILL SEE PRECIP...WITH POTENTIAL FOR UP TO AN INCH OF ADDITIONAL PRECIP DURING THIS TIME PERIOD. USED A BROAD CONSENSUS OF GUIDANCE DURING THIS PERIOD. THE UPPER LOW WILL CONTINUE TO WEAKEN AND MOVE SLOWLY NE INTO LATE WEEK BEFORE ADDITIONAL UPPER LEVEL ENERGY MOVES INTO THE REGION LATE THIS WEEK INTO THE WEEKEND...LEADING TO CONTINUED WET WEATHER...BUT AMOUNTS WILL BE LOWER THROUGH THE REST OF THE WEEK. USED A CONSENSUS OF GUIDANCE FOR THIS PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 129 AM EDT MON APR 28 2014 VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD UNDER MID CLOUDS. E-NE WINDS COULD GUST NEAR 25 KT AT ALL TAF SITES AS PRES GRADIENT TIGHTENS AHEAD OF LOW PRES OVER THE CENTRAL PLAINS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 432 PM EDT SUN APR 27 2014 EAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE DEEPENS OVER THE PLAINS. EXPECT ENE GALES TO 35KTS OVER WESTERN LK SUPERIOR TOWARD DULUTH INTO TUE MORNING. EAST GALES ARE THEN EXPECTED LATE TONIGHT INTO MON OVER THE REST OF THE WESTERN LAKE. WINDS WILL GRADUALLY DIMINISH TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE. WINDS ARE EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED INTO THU AS THE LOW FILLS AND REMAINS NEAR UPPER MICHIGAN. && .HYDROLOGY... ISSUED AT 358 AM EDT MON APR 28 2014 RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER NEAR NAHMA JUNCTION. AT LEAST THROUGH TONIGHT THESE RIVERS ARE NOT EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS WILL START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF HIGHER QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK. REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 11 AM EDT /10 AM CDT/ TUESDAY FOR LSZ162. GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...TITUS AVIATION...07/JV MARINE...JLB HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
132 AM EDT MON APR 28 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 432 PM EDT SUN APR 27 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER LEVEL TROUGH THROUGH THE NW CONUS WITH A LOW OVER WRN KS AND A DOWNSTREAM RIDGE FROM THE SE CONUS THROUGH WRN LAKES INTO MANITOBA. AT THE SFC...A BRISK ERLY FLOW PREVAILED THROUGH THE NRN LAKES BETWEEN HIGH PRES OVER HUDSON BAY AND A DEEP LOW OVER NW KS. AN INITIAL BAND OF LIGHT PCPN WAS PRODUCING MAINLY JUST SPRINKLES INTO THE FAR WRN CWA NEAR IWD AS IT ENCOUNTERS THE VERY DRY LAYER BELOW 750 MB. HOWEVER...A MORE SUBSTANTIAL AREA OF RAIN OVER WRN INTO N CNTRL WI...SUPPORTED BY 300K ISENTROPIC LIFT WAS LIFTING TOWARD UPPER MI. TONIGHT...RADAR TRENDS AND SHORT TERM MODELS SUGGEST THAT SOME LIGHT SHOWERS WILL MOVE INTO THE WEST LATE THIS AFTERNOON AND EVENING. HOWEVER...THERE IS A LOWER CHANCE THAT THERE WILL BE MEASURABLE PCPN GIVEN THE AMOUNT OF DRY AIR TO OVERCOME WITH THE ERLY LOW LEVEL INFLOW. FARTHER TO THE EAST...OVER S CNTRL UPPER MI...THE DRY AIR...PER 12Z APX SOUNDING...SHOULD BE MORE EFFECTIVE AT SLOWING THE ADVANCE AND REDUCING PCPN CHANCES. WITH EVAPORATIVE COOLING AT THE LEADING EDGE OF THE PCPN...SOME SNOW OR SLEET MAY ALSO MIX IN WITH THE RAIN LATE THIS EVENING AND OVERNIGHT...PER NAM LOW LEVEL THICKNESS AND WET-BULB ZERO HEIGHTS. MON...THE MODELS WERE IN SLIGHTLY BETTER AGREEMENT IN HANDLING THE ADVANCE OF PCPN INTO UPPER MICHIGAN. THE NAM/GFS/ECMWF WERE NOW ON THE SLOWER SIDE COMPARED TO GEM. AS THE MID/UPPER LEVEL LOW SLOWLY WOBBLES TO THE NORTHEAST AND AN ELONGATED TROUGH/FRONT EXTENDS FROM SRN IA INTO NRN INDIANA. ANOTHER BAND OF RAIN WILL MOVE TOWARD UPPER MI WITH INCREASING 300K-305K ISENTROPIC ASCENT NORTH OF THE 850 MB WARM FRONT THROUGH CNTRL WI. THERE IS STILL LIKELY TO BE SHARP CUTOFF TO THE NRN EDGE OF THE PCPN BAND THROUGH CNTRL UPPER MI. THE HIGHEST CHANCES WILL REMAIN ALONG THE WI BORDER WITH ONLY A SLIGHT CHANCE OVER THE NORTH. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 432 PM EDT SUN APR 27 2014 UPPER LOW OVER THE CENTRAL PLAINS MONDAY AFTERNOON AND ASSOCIATED SFC LOW AND WARM FRONT WILL BE MAIN FOCUS FOR THE FORECAST THIS UPCOMING WEEK. MODELS VERY LOCKED INTO IDEA THAT WHILE WIDESPREAD SHRA AND TSRA AND SEVERE WEATHER IMPACT MID TO LOWER MISSISSIPPI RIVER VALLEY...ADDITIONAL SHRA/TSRA DEVELOP LATE MONDAY AFTN ALONG WARM FRONT EXTENDING TO THE EAST OF SFC LOW OVER NEB. THIS IS IN RESPONSE TO SHORTWAVE/PV ANAMOLY LIFTING AHEAD OF PARENT UPPER LOW. POSSIBLE THAT ADDITIONAL SHRA WILL ALREADY BE LIFTING TOWARD UPR MICHIGAN AS WELL DUE TO REMNANTS OF SHRA/TSRA DEVELOPING OVER THE UPPER MISSISSIPPI RIVER VALLEY MONDAY MORNING PER SSW-NNE ORIENTED FORWARD PROPAGATING CORFIDI VECTORS AND H85-H7 MOSITURE TRANSPORT. AREA OF SHRA/TSRA ALONG WARM FRONT WILL GLIDE TOWARD UPR MICHIGAN OVERNIGHT INTO TUESDAY MORNING DUE TO THE ARRIVAL OF SHORTWAVE AND H85-H5 Q-VECTOR CONVERGENCE ALONG WITH VEERING H85-H7 FLOW FM ESE TO MORE SSW. FOLLOWING THE Q-VECTOR CONVERGENCE AND RIBBON OF MOISTURE TRANSPORT...EXPECT MOST PRECIPITATION TO OCCUR IN THE MORNING. BASED ON 1000-850MB THICKNESSES/H85 TEMPS AND HEIGHT OF WBZERO...MAY SEE SNOW OR A RAIN/SNOW MIX OVER HIGHER TERRAIN OF WEST AND NCNTRL UPR MICHIGAN PERHAPS EVEN LINGERING INTO MID AFTN. MINOR SNOW ACCUMULATIONS SEEM POSSIBLE...ESPECIALLY ON GRASSY SURFACES. WILL LEAVE OUT OF HAZARDOUS WEATHER OUTLOOK FOR NOW AS TRAVEL WOULD PROBABLY BE ONLY MINIMALLY IMPACTED. BY LATE AFTN...EXPECT CHANGE OVER TO RAIN AS H85 TEMPS SURGE ABOVE ZERO. THIS MAY BE OCCURRING WHEN MAJORITY OF HEAVIER PRECIPITATION IS COMING TO AN END THOUGH. BY TUE EVENING...FORECAST SOUNDINGS SHOW DRYING ABOVE H9...SO THERE MAY BE DRIZZLE. TEMPS WILL CONTINUE TO RISE SFC-H85 SO BY THAT TIME WILL ONLY BE DEALING WITH LIQUID PRECIP. ON WEDNESDAY...PRIMARY SHORTWAVE LIFTS NORTH ACROSS THE UPPER GREAT LAKES. SEEMS TO BE A TREND FOR BEST MOISTURE TRANSPORT TO MISS UPR MICHIGAN TO THE EAST...ALLOWING BULK OF RAIN ON WEDNESDAY TO SURGE NORTH ACROSS THE LOWER LAKES. HOWEVER...SIGNAL THAT HIGHER THETA-E AT H8-H7 WILL BE WRAPPING WESTWARD ACROSS UPR MICHIGAN ON CYCLONIC NORTH SIDE OF FILLING SFC-H85 LOWS. RAIN ON WEDNESDAY WOULD ONLY BE BOLSTERED OVER HIGHER TERRAIN OF WESTERN AND NORTH CENTRAL UPPER MICHIGAN WITH NE BLYR WINDS. WEDNESDAY NIGHT INTO THURSDAY...THE VERTICALLY STACKED LOW PRESSURE SYSTEM REMAINS NEARLY STATIONARY OVER THE UPPER GREAT LAKES. UNSETTLED WEATHER PATTERN AND WILL KEEP WITH THE CHANCES THAT CONSENSUS OF MODELS SHOWS. THE GREATEST CHANCES OF RAIN WILL BE ALONG AND NORTH AND WEST OF H85 LOW WHERE HIGHER THETA-E CONTINUES TO WRAP AROUND THE LOW AND ALSO WHERE LINGERING Q-VECTOR CONVERGENCE IS LOCATED. YET...CANNOT RULE OUT PRECIP JUST ABOUT ANYWHERE OVER THE CWA AS OTHER SHORTWAVES WILL PROBABLY BE CYCLING AROUND THE MAIN UPPER LOW CENTER AND THERE SHOULD BE PLENTY OF LOW-MID LEVEL MOISTURE REMAINING OVER REGION. DO NOT EXPECT THE PRECIP THAT OCCURS BEYOND WEDNESDAY EVENING TO BE HEAVY AS RICHER MOISTURE WILL BE HEADING WELL TO THE EAST OF THE REGION BY THAT TIME. GRADUALLY COOLING TEMPERATURES ALOFT AND EVENTUALLY AT THE SFC /H85 TEMPS DROPPING BLO 0C PER GFS/ECMWF/ COULD RESULT IN MIXED RAIN AND SNOW OVER PORTIONS OF CWA LATER WEDNESDAY NIGHT INTO THURSDAY MORNING AND AGAIN THURSDAY NIGHT INTO FRIDAY MORNING. MAY EVEN SEE MIX LATER FRIDAY NIGHT INTO SATURDAY MORNING. ONLY SLIGHT CHANCES FOR POPS BY THAT TIME THOUGH AS SYSTEM WILL BE UNRAVELLING AS IT LIFTS EAST AND NORTH AWAY FM LK SUPERIOR/UPR MICHIGAN. UPPER LEVEL TROUGH STILL FORECAST OVER THE REGION NEXT WEEKEND...SO NO WARM UP IS IN STORE. COULD BE MORE RAIN/SNOW BY NEXT SUNDAY AS THERE ARE HINTS OF STRONGER SYSTEM WORKING THROUGH AT THAT TIME. HOWEVER...SINCE THE TIMING FOR THAT SYSTEM WILL BE COMPLETELY DICTATED BY THE UPPER LOW THIS WEEK AND HOW QUICK IT DEPARTS...THERE IS CONSIDERABLE UNCERTAINTY IN HOW ALL THESE DETAILS WILL EVENTUALLY WORK OUT. THUS...CHANGES TO MODEL CONSENSUS BEYEOND THURSDAY WERE MINIMAL GIVEN THE UNCERTAINTY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 129 AM EDT MON APR 28 2014 VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD UNDER MID CLOUDS. E-NE WINDS COULD GUST NEAR 25 KT AT ALL TAF SITES AS PRES GRADIENT TIGHTENS AHEAD OF LOW PRES OVER THE CENTRAL PLAINS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 432 PM EDT SUN APR 27 2014 EAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE DEEPENS OVER THE PLAINS. EXPECT ENE GALES TO 35KTS OVER WESTERN LK SUPERIOR TOWARD DULUTH INTO TUE MORNING. EAST GALES ARE THEN EXPECTED LATE TONIGHT INTO MON OVER THE REST OF THE WESTERN LAKE. WINDS WILL GRADUALLY DIMINISH TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE. WINDS ARE EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED INTO THU AS THE LOW FILLS AND REMAINS NEAR UPPER MICHIGAN. && .HYDROLOGY... ISSUED AT 432 PM EDT SUN APR 27 2014 RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS...AND THE STURGEON RIVER NEAR NAHMA JUNCTION IN DELTA COUNTY. AT LEAST THROUGH MONDAY NONE OF THESE RIVERS ARE EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS MAY START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY LATE THIS WEEK. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK...ESPECIALLY OVER THE NORTHWEST HALF OF UPPER MICHIGAN WHERE SNOWMELT WILL ALSO ADD TO THE RUNOFF. REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE. WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. HOWEVER...THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 11 AM EDT /10 AM CDT/ TUESDAY FOR LSZ162. GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...07/JV MARINE...JLB HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
342 AM CDT Mon Apr 28 2014 .SHORT TERM: (Through Late This Afternoon) Issued at 152 AM CDT Mon Apr 28 2014 Latest HRRR weakens most of the convection currently across our forecast area, or shifts it southeast of the region by 12z Monday. There may be a brief lull in the convection early this morning, then new convection should break out late this morning and early this afternoon from Edina to Quincy and south through the St Louis metro area to the FAM area, then shift eastward through our IL counties later this afternoon. This will occur as a shortwave ejects out of the southern Plains into southeast MO and a cold front/dry line surges eastward into eastern MO by 00z Tue. Should have CAPEs up to 2000-2500 J/Kg ahead of the cold front around 18z Monday with surface LI values down to around -10. Strongest low-mid level wind shear should be across southeast MO and southwest IL with strong 500 mb wind max moving through AR into portions of southeast MO, southern IL, and western portions of TN and KY. The severe weather threat should be over the eastern portion of our area, in portions of west central and southwest IL with the primary threat being large hail and damaging winds. This will occur from the late morning, through the afternoon and into the early evening hours. GKS .LONG TERM: (Tonight through Sunday) Issued at 341 AM CDT Mon Apr 28 2014 The showers and thunderstorms should be confined to areas east of the Mississippi River this evening and should be weakening by late evening as the higher surface dewpoints and instability shifts east of our forecast area. Little if any precipitation should be left late tonight. Temperatures will be cooler tonight due to low level cold air advection in our area south of the upper level and associated surface low. More showers and a few thunderstorms on Tuesday as the moisture wraps around the slow moving upper/surface low north of our area. The best chance for rain will be across the northwest half of our forecast area. The models keep the showers going Tuesday night as shortwaves rotate around the mid-upper level low. The gradual cooling trend will continue with well below normal temperatures for Wednesday and Wednesday night. The GFS and ECMWF models drop the zero degree C 850 mb isotherm southeastward into our forecast area Tuesday night or Wednesday, the cooler NAM even earlier. Although there will likely be rain across our area again on Wednesday it should be on the light side. The rain should be mainly diurnal on Thursday and Friday and favor the northern portion of our forecast area as the upper level low weakens and moves into the Great Lakes region. Will see warmer high temperatures for the weekend as the upper level heights begin to rise and southerly surface/low level flow returns Saturday night. Low-mid level warm air advection ahead of a weak shortwave and associated surface low may bring showers to the extreme northern portion of our forecast area late Saturday night and Sunday. GKS && .AVIATION: (For the 06z TAFs through 06z Monday Night) Issued at 1147 PM CDT Sun Apr 27 2014 Back edge of storms slowly making their way east. Precipitation should come to an end at KCOU by taf issuance time. As for rest of taf sites, kept mention of showers and thunderstorms through about 08z Monday. Mvfr/ifr cigs/vsbys expected with the heavier activity, otherwise vfr conditions to prevail. Next round of activity will be with main cold front later today, though they will fire up just east of KCOU, so kept them dry. As for rest of taf sites, added vcnty TS mention after 17z then coming to an end by 23z. As for winds, to prevail from the southeast to south before veering to the southwest behind the cold front. Could see winds pickup by 17z with gusts to near 25 kts at times before diminishing this evening. Specifics for KSTL: Back edge of storms slowly making their way east. Precipitation should come to an end through about 08z. Mvfr/ifr cigs/vsbys expected with the heavier activity, otherwise vfr conditions to prevail. Next round of activity will be with main cold front later today, so added vcnty TS mention after 17z then coming to an end by 23z. As for winds, to prevail from the southeast to south before veering to the southwest behind the cold front. Could see winds pickup by 17z with gusts to near 25 kts at times before diminishing this evening. Byrd && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
154 AM CDT Mon Apr 28 2014 .SHORT TERM: (Through Late This Afternoon) Issued at 152 AM CDT Mon Apr 28 2014 Latest HRRR weakens most of the convection currently across our forecast area, or shifts it southeast of the region by 12z Monday. There may be a brief lull in the convection early this morning, then new convection should break out late this morning and early this afternoon from Edina to Quincy and south through the St Louis metro area to the FAM area, then shift eastward through our IL counties later this afternoon. This will occur as a shortwave ejects out of the southern Plains into southeast MO and a cold front/dry line surges eastward into eastern MO by 00z Tue. Should have CAPEs up to 2000-2500 J/Kg ahead of the cold front around 18z Monday with surface LI values down to around -10. Strongest low-mid level wind shear should be across southeast MO and southwest IL with strong 500 mb wind max moving through AR into portions of southeast MO, southern IL, and western portions of TN and KY. The severe weather threat should be over the eastern portion of our area, in portions of west central and southwest IL with the primary threat being large hail and damaging winds. This will occur from the late morning, through the afternoon and into the early evening hours. GKS .LONG TERM: (Monday through Next Sunday) Issued at 355 PM CDT Sun Apr 27 2014 Mon...Thunderstorms are expected to develop on Mon ahead of the approaching cold front/dryline. Favorable environmental parameters for severe weather include H7-H5 lapse rates of 7-8 deg C/km, 0-6km bulk shear of 40-70 kts, and at least 1000 J/kg of CAPE. The greatest threat appears to be across the eastern half of the CWA during the afternoon hours when this area will be beneath the left exit region of an upper jet streak. Tue through Thu...With cold temperatures aloft creating steep lapse rates, cyclonic flow aloft, multiple shortwaves rotating through the trough, and fairly low freezing levels, this looks like a good pattern for diurnally-driven afternoon SHRA/TSRA with small hail. Pcpn coverage should diminish quickly after sunset each day. Expect daily temperatures to be 10-15 degrees cooler than average during this period. Fri through Sat...Although the approximate center of the large upper low is forecast to have moved north and east of MO/IL by Fri, models show that a broad trough remains in place with several shortwaves moving through the flow. These disturbances could support SHRA/TSRA at times. Kanofsky && .AVIATION: (For the 06z TAFs through 06z Monday Night) Issued at 1147 PM CDT Sun Apr 27 2014 Back edge of storms slowly making their way east. Precipitation should come to an end at KCOU by taf issuance time. As for rest of taf sites, kept mention of showers and thunderstorms through about 08z Monday. Mvfr/ifr cigs/vsbys expected with the heavier activity, otherwise vfr conditions to prevail. Next round of activity will be with main cold front later today, though they will fire up just east of KCOU, so kept them dry. As for rest of taf sites, added vcnty TS mention after 17z then coming to an end by 23z. As for winds, to prevail from the southeast to south before veering to the southwest behind the cold front. Could see winds pickup by 17z with gusts to near 25 kts at times before diminishing this evening. Specifics for KSTL: Back edge of storms slowly making their way east. Precipitation should come to an end through about 08z. Mvfr/ifr cigs/vsbys expected with the heavier activity, otherwise vfr conditions to prevail. Next round of activity will be with main cold front later today, so added vcnty TS mention after 17z then coming to an end by 23z. As for winds, to prevail from the southeast to south before veering to the southwest behind the cold front. Could see winds pickup by 17z with gusts to near 25 kts at times before diminishing this evening. Byrd && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1227 AM CDT MON APR 28 2014 .SYNOPSIS... ISSUED AT 407 PM CDT SUN APR 27 2014 A POTENT...UPPER LEVEL LOW WAS CENTERED OVER WESTERN KS THIS AFTERNOON. A NICE JET STREAK EXTENDED FROM NORTHERN CALIFORNIA...AROUND THE BASE OF THE LOW...NOSING INTO CENTRAL KS. DOWNSTREAM OF THE TROUGH...A HIGH AMPLITUDE...NEGATIVE TILTED RIDGE EXTENDED FROM THE SERN STATES INTO NRN MANITOBA. AT THE SURFACE...LOW PRESSURE WAS NOTED OVER GOODLAND KS WITH A COLD FRONT EXTENDING SSW INTO NERN NEW MEXICO. AN INVERTED TROUGH AXIS EXTENDED NORTH OF THE LOW ALONG THE COLORADO/KS BORDER INTO THE NEBRASKA PANHANDLE. WEST OF THIS INVERTED TROUGH...TEMPS WERE IN THE LOWER TO MID 40S...WHILE EAST OF THE TROUGH AXIS...TEMPS WERE IN THE 60S AND 70S. A DRY LINE...EXTENDED NORTH OF THE SURFACE LOW INTO SWRN NEBRASKA...WHERE IT TURNED SOUTHEAST INTO SOUTH CENTRAL NEBRASKA. THUNDERSTORMS HAVE FIRED ALONG THE DRYLINE THIS AFTERNOON WITH THE TORNADIC THREAT GENERALLY IN SOUTH CENTRAL NEBRASKA WHERE BETTER DIRECTIONAL SHEAR EXISTS. FURTHER NORTH ACROSS THE CENTRAL AND NORTHERN SANDHILLS...GOOD SPEED SHEAR EXISTS...HOWEVER DIRECTIONAL SHEAR IS LACKING PER LATEST KLNX VAD WIND PROFILER. IN THESE AREAS...STRONG TO SEVERE STORMS HAVE OCCURRED WITH LARGE HAIL BEING THE MAIN SEVERE THREAT. && .UPDATE... ISSUED AT 1225 AM CDT MON APR 28 2014 CURRENT UPDATE TO ACCOUNT FOR SNOW INTO PERKINS COUNTY. LAYING DOWN SOME SNOW ON NDOR CAMERAS. UPDATE ISSUED AT 1027 PM CDT SUN APR 27 2014 THE HIGH WIND WATCH HAS BEEN UPGRADED TO A HIGH WIND WARNING BASED ON THE RAP AND 00Z NAM MODEL RUNS WHICH KEEP THE STRONGEST WINDS ALONG HIGHWAY 61. THE AREA TO WATCH IS THE CENTRAL SANDHILLS WHERE THE RAP AND NAM SHOW VERY STRONG 500M AGL WINDS APPROACHING 40 MPH AT THE SFC MONDAY AFTERNOON. NOTE THE FORECAST CONTINUES STRONG OR HIGH WINDS MONDAY NIGHT AND TUESDAY WHICH WOULD NECESSITATE EXTENSIONS OF THE ON GOING HIGH LIGHTS. UPDATE ISSUED AT 837 PM CDT SUN APR 27 2014 A LOOK AT THE NEBRASKA DOR CAMS AND THE RAP MODEL SUGGEST WINTER WEATHER ADVISORY CONDITIONS ACROSS SHERIDAN AND WESTERN CHERRY COUNTIES. THE RAP INDICATES SEVERAL INCHES OF WET SNOW THIS EVENING WHICH TAPERS OFF OR MIXES WITH RAIN AFTER MIDNIGHT. RADAR INDICATES A DEFORMATION ZONE UNDERWAY ACROSS THIS AREA BUT MAINLY ACROSS NRN SHERIDAN COUNTY. A WINTER ADVISORY IS IN PLACE FOR THESE AREA AND IT OPERATES UNTIL 13Z. THE FORECAST UPDATE FOLLOWS 50 PERCENT OF THE 23Z RAP AND 50 PERCENT OF THE PREVIOUS FORECAST. THE PTYPE USES THE RAP MODEL WHICH SPREADS WET SNOW AS FAR SOUTH AS DEUEL COUNTY BUT LITTLE ACCUMULATION IS EXPECTED THAT FAR SOUTH. IT LOOKS LIKE THE FAVORED AREA FOR SNOW IS NORTHWEST NEBRASKA...NORTH OF THE NORTH PLATTE VALLEY FOLLOWING THE H750 MB FRONT WHICH IS STRONGLY STACKED AND MOVING VERY SLOWLY EAST TONIGHT. NOTE THE 23Z RAP PRODUCES OVER 1 INCH OF QPF ACROSS SHERIDAN COUNTY TONIGHT. THE FORECAST USES A RATIO OF 6 TO 1 FOR 3 TO NEARLY 8 INCHES OF SNOW FAVORING PINE RIDGE. && .SHORT TERM...(THIS EVENING THROUGH TONIGHT) ISSUED AT 407 PM CDT SUN APR 27 2014 FORECAST CONCERNS CONTINUE WITH THUNDERSTORM CHANCES TONIGHT...THEN LEAD TO FORMATION OF DEFORMATION BAND AND SNOW POTENTIAL. THE UPPER LOW WAS CENTERED OVER NORTHWEST KANSAS AS OF 20Z...WITH THE SURFACE CIRCULATION ALMOST DIRECTLY OVER KCBK. WITH THE SYSTEM BEING NEARLY VERTICALLY STACKED OVER NORTHWEST KANSAS THIS AFTERNOON...THERE IS CONCERN THAT THE MODELS MAY BE TRYING TO KICK THE SYSTEM EAST TOO QUICKLY THIS EVENING AND OVERNIGHT. THIS WILL IMPACT THE AREAS THAT CONTINUE TO SEE CONVECTION...WHERE THE PRECIPITATION FALLS...WHERE THE WINDS STRENGTHEN...AND WHERE AND WHEN THE RAIN SWITCHES OVER TO SNOW. THE LATEST RAP MODEL MOVES THE SURFACE CIRCULATION TO NEAR KMCK BY 00Z THIS EVENING THEN OVER KHSI AT 06Z AND THEN MOVES IT UP TO AROUND KBVN BY 12Z. THIS SOLUTION IS QUITE SIMILAR TO THE NEW 18Z NAM. THESE SOLUTIONS CONTINUE TO TRANSPORT MOISTURE AROUND THE CIRCULATION AND ACROSS WESTERN AND CENTRAL NEBRASKA THROUGH THE OVERNIGHT HOURS. STRONG FRONTOGENESIS SETS UP ON THE BACK SIDE OF THE SYSTEM...CENTERED OVER THE PANHANDLE AND WESTERN SANDHILLS OVERNIGHT. WITH GOOD MOISTURE IN THAT AREA AND SUBSTANTIAL LIFT DUE TO THE LARGE SCALE FORCING AND FRONTOGENESIS...EXPECT A GOOD DEFORMATION BAND TO BE ONGOING THROUGH MUCH OF THE NIGHT. SOME AREAS COULD SEE UP TO AN INCH OF MOISTURE BY 12Z MONDAY MORNING. THE BIG QUESTION WITH THE PRECIPITATION IS IF ENOUGH COLD AIR WILL MOVE IN TO GET SOME AREAS TO GET A CHANGEOVER TO SNOW. THE NAM AND THE RAP BOTH SHOW WET BULB PROFILES BELOW ZERO UNTIL ABOUT 300FT OR LESS ABOVE THE GROUND IN AREAS OVER THE NORTHEAST PANHANDLE...ESPECIALLY THE PINE RIDGE. IF THIS TURNS OUT...MAY SEE LOTS OF SNOW FALLING BUT WILL BE MELTING WHEN HITTING THE SURFACE OR JUST PRIOR. BUT...EVEN ONE DEGREE DIFFERENCE WILL BE ALL THAT IS NEEDED TO CHANGE OVER COMPLETELY TO SNOW AND IF RATES BECOME STRONG ENOUGH...COULD GET DECENT ACCUMULATIONS. AT THIS TIME...WITH THE MODELS ALL KEEPING THE WET BULB TEMPERATURE ABOVE 0C...DID PUT A COMPLETE CHANGEOVER TO SNOW IN THE NORTHWEST ZONES...BUT ONLY HAVE ACCUMULATIONS UP TO 2 INCHES ASSUMING THERE WILL BE SUBSTANTIAL MELTING AT THE SURFACE. THE NEXT QUESTION WILL BE WHAT WILL REMAIN FOR CONVECTION AND THUNDERSTORM CHANCES OVERNIGHT. KEPT AT LEAST A MENTION OF ISOLATED THUNDER IN AREAS ALONG THE INVERTED TROUGH GOING NORTH OF THE SURFACE LOW AS MOISTURE AND SOME WEAK INSTABILITY WILL CONTINUE TO CIRCULATE AROUND THE SYSTEM. MOVING ON TO WINDS...A VERY TIGHT PRESSURE GRADIENT WILL BE SEEN ON THE BACKSIDE OF THE SYSTEM...WHICH SHOULD CAUSE WINDS TO STRENGTHEN ACROSS THE AREA AS THE LOW MOVES EAST TONIGHT. THE ONGOING WIND ADVISORY FOR AREAS MAINLY WEST OF HIGHWAY 83 FOR THE OVERNIGHT PERIODS CONTINUES TO LOOK GOOD AS SUSTAINED WINDS AROUND 30MPH STILL LOOK LIKELY. WITH THE POTENTIAL FOR MODERATE TO HEAVY SNOW AND STRONG WINDS OVER THE NORTHEAST PART OF THE FORECAST AREA TONIGHT...DID CONSIDER A NEED FOR A WINTER WEATHER ADVISORY FOR LATE TONIGHT INTO MONDAY MORNING. AT THIS TIME...DUE TO THE UNCERTAINTY ON THE SWITCHOVER TO SNOW...OPTED TO NOT ISSUE AT THIS TIME AND WILL MONITOR CLOSELY IF HEADLINES ARE NEEDED. .LONG TERM...(MONDAY THROUGH SUNDAY) ISSUED AT 407 PM CDT SUN APR 27 2014 TOMORROW THROUGH WEDNESDAY...MAIN FORECAST CHALLENGES ARE WINDS AND PRECIPITATION CHANCES IN ASSOCIATION WITH A SLOW MOVING UPPER LEVEL LOW...WHICH WILL MIGRATE FROM EASTERN NEBRASKA INTO THE UPPER MISSISSIPPI VALLEY OVER THE NEXT 24 TO 84 HOURS. IN ADDITION TO PRECIPITATION CHANCES...THE THREAT FOR SNOW...PARTICULARLY DURING THE NIGHTTIME HOURS...WILL BE A CONCERN ACROSS NORTHERN NEBRASKA MONDAY NIGHT AND TUESDAY NIGHT. FOR MONDAY...PRECIPITATION CHANCES AND WINDS WILL BE THE MAIN FORECASTING CONCERN. ON MONDAY...THE MAIN UPPER LEVEL LOW WILL MEANDER ACROSS CENTRAL NEBRASKA...DRIFTING INTO EASTERN NEBRASKA BY LATE AFTERNOON. STRONG WINDS WILL DEVELOP ACROSS CENTRAL AND WESTERN PORTIONS OF THE FORECAST AREA MONDAY AS H85 WINDS REACH 40 TO 50 KTS IN THE SOUTHWEST AND SOUTHEASTERN PANHANDLE MONDAY AFTERNOON. WIND SPEEDS DECREASE FAIRLY QUICKLY EAST OF THE HIGHWAY 83 CORRIDOR AND DO NOT REALLY BEGIN TO KICK IN UNTIL MONDAY EVENING. TO AVOID CONFUSION...DECIDED TO HOIST A HIGH WIND WATCH FOR LOCATIONS ROUGHLY WEST OF A LINE FROM HAYES CENTER...TO ARTHUR...TO GARDEN COUNTY. IN THESE AREAS...A WIND ADVISORY WILL LIKELY BE NEEDED TOMORROW...BUT AT THIS TIME...I DO NOT HAVE ENOUGH CONFIDENCE TO ISSUE A HIGH WIND WARNING AND WILL ISSUE A WATCH AND LET THE MIDNIGHT CREW MAKE THE CALL. FURTHER EAST...TO THE HIGHWAY 83 CORRIDOR...NORTHERLY WINDS WILL INCREASE BY MIDDAY AND ARE EXPECTED TO REACH ADVISORY CRITERIA...FROM LINCOLN COUNTY NWD TO WESTERN CHERRY COUNTY AND WILL HOIST A WIND ADVISORY FOR THESE AREAS. IN ADDITION TO WIND...THERE IS STILL A SMALL THREAT FOR ACCUMULATING SNOWS MONDAY MORNING IN THE FAR NORTHWESTERN FORECAST AREA IN THE VICINITY OF THE PINE RIDGE. LIKE YESTERDAY...THE NAM HAS THE COLDEST BOUNDARY LAYER OF THE THREE MID RANGE MODELS. GIVEN THE LACK OF COLD UPSTREAM AIR ACROSS NERN WYOMING AND WESTERN SOUTH DAKOTA ATTM...AM INCLINED TO TREND TEMPS TOWARD THE WARMER GFS AND ECMWF SOLNS. WITH THIS IN MIND...HAVE WORDED THE FORECAST WITH A RAIN SNOW MIX THROUGH MID MORNING WITH LITTLE OR NO SNOW ACCUMS EXPECTED. WILL CONTINUE TO MONITOR THIS AREA CLOSELY. AS THE DAY PROGRESSES...WIDESPREAD RAIN WILL CONTINUE...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE FORECAST AREA...WHERE A STRONG MID LEVEL DEFORMATION ZONE WILL SET UP AND PERSISTENT ISENTROPIC LIFT CONTINUES THROUGH THE AFTERNOON HOURS. ON MONDAY NIGHT...WINDS WILL INCREASE IN THE EAST AND SUBSIDE SOME IN THE WEST AS THE UPPER LEVEL LOW MEANDERS INTO SWRN IOWA AND NORTHWEST MISSOURI. WINDS WILL REMAIN ON THE GUSTY SIDE INTO THE OVERNIGHT HOURS...WHICH MAY NECESSITATE ISSUANCE OF A WIND ADVISORY MONDAY NIGHT. BASED ON THE LATEST MAV GUIDANCE AND BUFKIT DATA...ALMOST THE ENTIRE FORECAST AREA MAY NEED A WIND ADVISORY FOR MONDAY NIGHT. GIVEN THE ONGOING WIND HEADLINES...WILL HOLD OFF ON ISSUANCE ATTM TO AVOID CONFUSION WITH OUR CURRENT HEADLINES. DECENT ISENTROPIC LIFT CONTINUES INTO TUESDAY MORNING...ESPECIALLY OVER CENTRAL AND NORTHERN NEBRASKA AND WILL CONTINUE LIKELY TO CATEGORICAL POPS OVERNIGHT. TUESDAY THROUGH WEDNESDAY...THE UPPER LEVEL LOW WILL MEANDER EAST ON TUESDAY INTO WEDNESDAY...ENDING UP OVER THE WESTERN GREAT LAKES BY THURSDAY MORNING. DURING THE PERIOD...THE THREAT FOR LIGHT RAIN WILL CONTINUE TUESDAY WITH GUSTY WINDS EXPECTED AS WELL. H85 WINDS WILL DECREASE TO 35 TO 45 KTS ON TUESDAY...SO ANOTHER MAY BE NEEDED FOR TUESDAY ACROSS MOST OF THE FORECAST AREA. TEMPS WILL REMAIN COOL HOWEVER WITH MOSTLY CLOUDY SKIES AND WITH H85 TEMPS RANGING FROM -2C IN THE NORTHEAST...TO 3 C IN THE SOUTHWEST...HIGHS TUESDAY WILL STRUGGLE TO GET OUT OF THE UPPER 30S TO 40S. ON WEDNESDAY...H85 TEMPS WILL WARM TO 1C IN THE NORTHEAST...TO 5C IN THE SOUTHWEST. AFTERNOON HIGHS WILL REBOUND SLIGHTLY TO THE 40S TO LOWER 50S. WINDS WILL BE SOMEWHAT LIGHTER...THOUGH WINDY WITH WIND SPEEDS OF 20 TO 30 MPH...WITH SOME HIGHER GUSTS TO 40 MPH. AT THIS TIME...AM NOT ANTICIPATING ANY WIND HEADLINES ATTM. WEDNESDAY NIGHT AND BEYOND...THE UPPER LEVEL LOW WILL BE ABSORBED BY THE NORTHERN STREAM AND LIFTED EAST TOWARD THE END OF THE WEEK. HOWEVER...LOW PRESSURE ALOFT WILL REMAIN ANCHORED OVER SOUTH CENTRAL CANADA...AND WILL FORCE COLD AIR INTO THE NORTHERN PLAINS LATE IN THE WEEK INTO THE WEEKEND. MAINLY DRY CONDITIONS ARE EXPECTED WITH THIS FLOW REGIME. HIGHS WILL BE MORE MARCH LIKE WITH READINGS IN THE 50S EXPECTED FRIDAY...SATURDAY AND SUNDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1141 PM CDT SUN APR 27 2014 WIDESPREAD MVFR/IFR IN RAIN AND SNOW IS EXPECTED TONIGHT THROUGH MONDAY EVENING AS A SLOW MOVING STORM TRACKS THROUGH THE CENTRAL PLAINS. WINDS 32035G45KT SHOULD REDEVELOP MONDAY MORNING AND SPREAD FROM WEST TO EAST THROUGH MONDAY AFTN. WINDS SUBSIDE AROUND SUNSET. && .LBF WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FROM 7 AM CDT /6 AM MDT/ THIS MORNING TO 7 PM CDT /6 PM MDT/ THIS EVENING FOR NEZ022-035-056>058-069-070. WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ THIS MORNING FOR NEZ022- 035-056>058-069-070. WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NEZ004- 023>025-036-037-059-071-094. WINTER WEATHER ADVISORY UNTIL 7 AM MDT MONDAY FOR NEZ004-094. WIND ADVISORY FROM 7 AM THIS MORNING TO 7 PM CDT THIS EVENING FOR NEZ005-006-008-009-026-027-038. && $$ UPDATE...POWER SYNOPSIS...CLB SHORT TERM...BROOKS LONG TERM...CLB AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1143 PM CDT SUN APR 27 2014 .SYNOPSIS... ISSUED AT 407 PM CDT SUN APR 27 2014 A POTENT...UPPER LEVEL LOW WAS CENTERED OVER WESTERN KS THIS AFTERNOON. A NICE JET STREAK EXTENDED FROM NORTHERN CALIFORNIA...AROUND THE BASE OF THE LOW...NOSING INTO CENTRAL KS. DOWNSTREAM OF THE TROUGH...A HIGH AMPLITUDE...NEGATIVE TILTED RIDGE EXTENDED FROM THE SERN STATES INTO NRN MANITOBA. AT THE SURFACE...LOW PRESSURE WAS NOTED OVER GOODLAND KS WITH A COLD FRONT EXTENDING SSW INTO NERN NEW MEXICO. AN INVERTED TROUGH AXIS EXTENDED NORTH OF THE LOW ALONG THE COLORADO/KS BORDER INTO THE NEBRASKA PANHANDLE. WEST OF THIS INVERTED TROUGH...TEMPS WERE IN THE LOWER TO MID 40S...WHILE EAST OF THE TROUGH AXIS...TEMPS WERE IN THE 60S AND 70S. A DRY LINE...EXTENDED NORTH OF THE SURFACE LOW INTO SWRN NEBRASKA...WHERE IT TURNED SOUTHEAST INTO SOUTH CENTRAL NEBRASKA. THUNDERSTORMS HAVE FIRED ALONG THE DRYLINE THIS AFTERNOON WITH THE TORNADIC THREAT GENERALLY IN SOUTH CENTRAL NEBRASKA WHERE BETTER DIRECTIONAL SHEAR EXISTS. FURTHER NORTH ACROSS THE CENTRAL AND NORTHERN SANDHILLS...GOOD SPEED SHEAR EXISTS...HOWEVER DIRECTIONAL SHEAR IS LACKING PER LATEST KLNX VAD WIND PROFILER. IN THESE AREAS...STRONG TO SEVERE STORMS HAVE OCCURRED WITH LARGE HAIL BEING THE MAIN SEVERE THREAT. && .UPDATE... ISSUED AT 1027 PM CDT SUN APR 27 2014 THE HIGH WIND WATCH HAS BEEN UPGRADED TO A HIGH WIND WARNING BASED ON THE RAP AND 00Z NAM MODEL RUNS WHICH KEEP THE STRONGEST WINDS ALONG HIGHWAY 61. THE AREA TO WATCH IS THE CENTRAL SANDHILLS WHERE THE RAP AND NAM SHOW VERY STRONG 500M AGL WINDS APPROACHING 40 MPH AT THE SFC MONDAY AFTERNOON. NOTE THE FORECAST CONTINUES STRONG OR HIGH WINDS MONDAY NIGHT AND TUESDAY WHICH WOULD NECESSITATE EXTENSIONS OF THE ON GOING HIGH LIGHTS. UPDATE ISSUED AT 837 PM CDT SUN APR 27 2014 A LOOK AT THE NEBRASKA DOR CAMS AND THE RAP MODEL SUGGEST WINTER WEATHER ADVISORY CONDITIONS ACROSS SHERIDAN AND WESTERN CHERRY COUNTIES. THE RAP INDICATES SEVERAL INCHES OF WET SNOW THIS EVENING WHICH TAPERS OFF OR MIXES WITH RAIN AFTER MIDNIGHT. RADAR INDICATES A DEFORMATION ZONE UNDERWAY ACROSS THIS AREA BUT MAINLY ACROSS NRN SHERIDAN COUNTY. A WINTER ADVISORY IS IN PLACE FOR THESE AREA AND IT OPERATES UNTIL 13Z. THE FORECAST UPDATE FOLLOWS 50 PERCENT OF THE 23Z RAP AND 50 PERCENT OF THE PREVIOUS FORECAST. THE PTYPE USES THE RAP MODEL WHICH SPREADS WET SNOW AS FAR SOUTH AS DEUEL COUNTY BUT LITTLE ACCUMULATION IS EXPECTED THAT FAR SOUTH. IT LOOKS LIKE THE FAVORED AREA FOR SNOW IS NORTHWEST NEBRASKA...NORTH OF THE NORTH PLATTE VALLEY FOLLOWING THE H750 MB FRONT WHICH IS STRONGLY STACKED AND MOVING VERY SLOWLY EAST TONIGHT. NOTE THE 23Z RAP PRODUCES OVER 1 INCH OF QPF ACROSS SHERIDAN COUNTY TONIGHT. THE FORECAST USES A RATIO OF 6 TO 1 FOR 3 TO NEARLY 8 INCHES OF SNOW FAVORING PINE RIDGE. && .SHORT TERM...(THIS EVENING THROUGH TONIGHT) ISSUED AT 407 PM CDT SUN APR 27 2014 FORECAST CONCERNS CONTINUE WITH THUNDERSTORM CHANCES TONIGHT...THEN LEAD TO FORMATION OF DEFORMATION BAND AND SNOW POTENTIAL. THE UPPER LOW WAS CENTERED OVER NORTHWEST KANSAS AS OF 20Z...WITH THE SURFACE CIRCULATION ALMOST DIRECTLY OVER KCBK. WITH THE SYSTEM BEING NEARLY VERTICALLY STACKED OVER NORTHWEST KANSAS THIS AFTERNOON...THERE IS CONCERN THAT THE MODELS MAY BE TRYING TO KICK THE SYSTEM EAST TOO QUICKLY THIS EVENING AND OVERNIGHT. THIS WILL IMPACT THE AREAS THAT CONTINUE TO SEE CONVECTION...WHERE THE PRECIPITATION FALLS...WHERE THE WINDS STRENGTHEN...AND WHERE AND WHEN THE RAIN SWITCHES OVER TO SNOW. THE LATEST RAP MODEL MOVES THE SURFACE CIRCULATION TO NEAR KMCK BY 00Z THIS EVENING THEN OVER KHSI AT 06Z AND THEN MOVES IT UP TO AROUND KBVN BY 12Z. THIS SOLUTION IS QUITE SIMILAR TO THE NEW 18Z NAM. THESE SOLUTIONS CONTINUE TO TRANSPORT MOISTURE AROUND THE CIRCULATION AND ACROSS WESTERN AND CENTRAL NEBRASKA THROUGH THE OVERNIGHT HOURS. STRONG FRONTOGENESIS SETS UP ON THE BACK SIDE OF THE SYSTEM...CENTERED OVER THE PANHANDLE AND WESTERN SANDHILLS OVERNIGHT. WITH GOOD MOISTURE IN THAT AREA AND SUBSTANTIAL LIFT DUE TO THE LARGE SCALE FORCING AND FRONTOGENESIS...EXPECT A GOOD DEFORMATION BAND TO BE ONGOING THROUGH MUCH OF THE NIGHT. SOME AREAS COULD SEE UP TO AN INCH OF MOISTURE BY 12Z MONDAY MORNING. THE BIG QUESTION WITH THE PRECIPITATION IS IF ENOUGH COLD AIR WILL MOVE IN TO GET SOME AREAS TO GET A CHANGEOVER TO SNOW. THE NAM AND THE RAP BOTH SHOW WET BULB PROFILES BELOW ZERO UNTIL ABOUT 300FT OR LESS ABOVE THE GROUND IN AREAS OVER THE NORTHEAST PANHANDLE...ESPECIALLY THE PINE RIDGE. IF THIS TURNS OUT...MAY SEE LOTS OF SNOW FALLING BUT WILL BE MELTING WHEN HITTING THE SURFACE OR JUST PRIOR. BUT...EVEN ONE DEGREE DIFFERENCE WILL BE ALL THAT IS NEEDED TO CHANGE OVER COMPLETELY TO SNOW AND IF RATES BECOME STRONG ENOUGH...COULD GET DECENT ACCUMULATIONS. AT THIS TIME...WITH THE MODELS ALL KEEPING THE WET BULB TEMPERATURE ABOVE 0C...DID PUT A COMPLETE CHANGEOVER TO SNOW IN THE NORTHWEST ZONES...BUT ONLY HAVE ACCUMULATIONS UP TO 2 INCHES ASSUMING THERE WILL BE SUBSTANTIAL MELTING AT THE SURFACE. THE NEXT QUESTION WILL BE WHAT WILL REMAIN FOR CONVECTION AND THUNDERSTORM CHANCES OVERNIGHT. KEPT AT LEAST A MENTION OF ISOLATED THUNDER IN AREAS ALONG THE INVERTED TROUGH GOING NORTH OF THE SURFACE LOW AS MOISTURE AND SOME WEAK INSTABILITY WILL CONTINUE TO CIRCULATE AROUND THE SYSTEM. MOVING ON TO WINDS...A VERY TIGHT PRESSURE GRADIENT WILL BE SEEN ON THE BACKSIDE OF THE SYSTEM...WHICH SHOULD CAUSE WINDS TO STRENGTHEN ACROSS THE AREA AS THE LOW MOVES EAST TONIGHT. THE ONGOING WIND ADVISORY FOR AREAS MAINLY WEST OF HIGHWAY 83 FOR THE OVERNIGHT PERIODS CONTINUES TO LOOK GOOD AS SUSTAINED WINDS AROUND 30MPH STILL LOOK LIKELY. WITH THE POTENTIAL FOR MODERATE TO HEAVY SNOW AND STRONG WINDS OVER THE NORTHEAST PART OF THE FORECAST AREA TONIGHT...DID CONSIDER A NEED FOR A WINTER WEATHER ADVISORY FOR LATE TONIGHT INTO MONDAY MORNING. AT THIS TIME...DUE TO THE UNCERTAINTY ON THE SWITCHOVER TO SNOW...OPTED TO NOT ISSUE AT THIS TIME AND WILL MONITOR CLOSELY IF HEADLINES ARE NEEDED. .LONG TERM...(MONDAY THROUGH SUNDAY) ISSUED AT 407 PM CDT SUN APR 27 2014 TOMORROW THROUGH WEDNESDAY...MAIN FORECAST CHALLENGES ARE WINDS AND PRECIPITATION CHANCES IN ASSOCIATION WITH A SLOW MOVING UPPER LEVEL LOW...WHICH WILL MIGRATE FROM EASTERN NEBRASKA INTO THE UPPER MISSISSIPPI VALLEY OVER THE NEXT 24 TO 84 HOURS. IN ADDITION TO PRECIPITATION CHANCES...THE THREAT FOR SNOW...PARTICULARLY DURING THE NIGHTTIME HOURS...WILL BE A CONCERN ACROSS NORTHERN NEBRASKA MONDAY NIGHT AND TUESDAY NIGHT. FOR MONDAY...PRECIPITATION CHANCES AND WINDS WILL BE THE MAIN FORECASTING CONCERN. ON MONDAY...THE MAIN UPPER LEVEL LOW WILL MEANDER ACROSS CENTRAL NEBRASKA...DRIFTING INTO EASTERN NEBRASKA BY LATE AFTERNOON. STRONG WINDS WILL DEVELOP ACROSS CENTRAL AND WESTERN PORTIONS OF THE FORECAST AREA MONDAY AS H85 WINDS REACH 40 TO 50 KTS IN THE SOUTHWEST AND SOUTHEASTERN PANHANDLE MONDAY AFTERNOON. WIND SPEEDS DECREASE FAIRLY QUICKLY EAST OF THE HIGHWAY 83 CORRIDOR AND DO NOT REALLY BEGIN TO KICK IN UNTIL MONDAY EVENING. TO AVOID CONFUSION...DECIDED TO HOIST A HIGH WIND WATCH FOR LOCATIONS ROUGHLY WEST OF A LINE FROM HAYES CENTER...TO ARTHUR...TO GARDEN COUNTY. IN THESE AREAS...A WIND ADVISORY WILL LIKELY BE NEEDED TOMORROW...BUT AT THIS TIME...I DO NOT HAVE ENOUGH CONFIDENCE TO ISSUE A HIGH WIND WARNING AND WILL ISSUE A WATCH AND LET THE MIDNIGHT CREW MAKE THE CALL. FURTHER EAST...TO THE HIGHWAY 83 CORRIDOR...NORTHERLY WINDS WILL INCREASE BY MIDDAY AND ARE EXPECTED TO REACH ADVISORY CRITERIA...FROM LINCOLN COUNTY NWD TO WESTERN CHERRY COUNTY AND WILL HOIST A WIND ADVISORY FOR THESE AREAS. IN ADDITION TO WIND...THERE IS STILL A SMALL THREAT FOR ACCUMULATING SNOWS MONDAY MORNING IN THE FAR NORTHWESTERN FORECAST AREA IN THE VICINITY OF THE PINE RIDGE. LIKE YESTERDAY...THE NAM HAS THE COLDEST BOUNDARY LAYER OF THE THREE MID RANGE MODELS. GIVEN THE LACK OF COLD UPSTREAM AIR ACROSS NERN WYOMING AND WESTERN SOUTH DAKOTA ATTM...AM INCLINED TO TREND TEMPS TOWARD THE WARMER GFS AND ECMWF SOLNS. WITH THIS IN MIND...HAVE WORDED THE FORECAST WITH A RAIN SNOW MIX THROUGH MID MORNING WITH LITTLE OR NO SNOW ACCUMS EXPECTED. WILL CONTINUE TO MONITOR THIS AREA CLOSELY. AS THE DAY PROGRESSES...WIDESPREAD RAIN WILL CONTINUE...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE FORECAST AREA...WHERE A STRONG MID LEVEL DEFORMATION ZONE WILL SET UP AND PERSISTENT ISENTROPIC LIFT CONTINUES THROUGH THE AFTERNOON HOURS. ON MONDAY NIGHT...WINDS WILL INCREASE IN THE EAST AND SUBSIDE SOME IN THE WEST AS THE UPPER LEVEL LOW MEANDERS INTO SWRN IOWA AND NORTHWEST MISSOURI. WINDS WILL REMAIN ON THE GUSTY SIDE INTO THE OVERNIGHT HOURS...WHICH MAY NECESSITATE ISSUANCE OF A WIND ADVISORY MONDAY NIGHT. BASED ON THE LATEST MAV GUIDANCE AND BUFKIT DATA...ALMOST THE ENTIRE FORECAST AREA MAY NEED A WIND ADVISORY FOR MONDAY NIGHT. GIVEN THE ONGOING WIND HEADLINES...WILL HOLD OFF ON ISSUANCE ATTM TO AVOID CONFUSION WITH OUR CURRENT HEADLINES. DECENT ISENTROPIC LIFT CONTINUES INTO TUESDAY MORNING...ESPECIALLY OVER CENTRAL AND NORTHERN NEBRASKA AND WILL CONTINUE LIKELY TO CATEGORICAL POPS OVERNIGHT. TUESDAY THROUGH WEDNESDAY...THE UPPER LEVEL LOW WILL MEANDER EAST ON TUESDAY INTO WEDNESDAY...ENDING UP OVER THE WESTERN GREAT LAKES BY THURSDAY MORNING. DURING THE PERIOD...THE THREAT FOR LIGHT RAIN WILL CONTINUE TUESDAY WITH GUSTY WINDS EXPECTED AS WELL. H85 WINDS WILL DECREASE TO 35 TO 45 KTS ON TUESDAY...SO ANOTHER MAY BE NEEDED FOR TUESDAY ACROSS MOST OF THE FORECAST AREA. TEMPS WILL REMAIN COOL HOWEVER WITH MOSTLY CLOUDY SKIES AND WITH H85 TEMPS RANGING FROM -2C IN THE NORTHEAST...TO 3 C IN THE SOUTHWEST...HIGHS TUESDAY WILL STRUGGLE TO GET OUT OF THE UPPER 30S TO 40S. ON WEDNESDAY...H85 TEMPS WILL WARM TO 1C IN THE NORTHEAST...TO 5C IN THE SOUTHWEST. AFTERNOON HIGHS WILL REBOUND SLIGHTLY TO THE 40S TO LOWER 50S. WINDS WILL BE SOMEWHAT LIGHTER...THOUGH WINDY WITH WIND SPEEDS OF 20 TO 30 MPH...WITH SOME HIGHER GUSTS TO 40 MPH. AT THIS TIME...AM NOT ANTICIPATING ANY WIND HEADLINES ATTM. WEDNESDAY NIGHT AND BEYOND...THE UPPER LEVEL LOW WILL BE ABSORBED BY THE NORTHERN STREAM AND LIFTED EAST TOWARD THE END OF THE WEEK. HOWEVER...LOW PRESSURE ALOFT WILL REMAIN ANCHORED OVER SOUTH CENTRAL CANADA...AND WILL FORCE COLD AIR INTO THE NORTHERN PLAINS LATE IN THE WEEK INTO THE WEEKEND. MAINLY DRY CONDITIONS ARE EXPECTED WITH THIS FLOW REGIME. HIGHS WILL BE MORE MARCH LIKE WITH READINGS IN THE 50S EXPECTED FRIDAY...SATURDAY AND SUNDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1141 PM CDT SUN APR 27 2014 WIDESPREAD MVFR/IFR IN RAIN AND SNOW IS EXPECTED TONIGHT THROUGH MONDAY EVENING AS A SLOW MOVING STORM TRACKS THROUGH THE CENTRAL PLAINS. WINDS 32035G45KT SHOULD REDEVELOP MONDAY MORNING AND SPREAD FROM WEST TO EAST THROUGH MONDAY AFTN. WINDS SUBSIDE AROUND SUNSET. && .LBF WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FROM 7 AM CDT /6 AM MDT/ TO 7 PM CDT /6 PM MDT/ MONDAY FOR NEZ022-035-056>058-069-070. WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NEZ022-035- 056>058-069-070. WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ MONDAY FOR NEZ004- 023>025-036-037-059-071-094. WINTER WEATHER ADVISORY UNTIL 7 AM MDT MONDAY FOR NEZ004-094. WIND ADVISORY FROM 7 AM TO 7 PM CDT MONDAY FOR NEZ005-006-008- 009-026-027-038. && $$ UPDATE...CDC SYNOPSIS...CLB SHORT TERM...BROOKS LONG TERM...CLB AVIATION...CDC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
335 AM CDT MON APR 28 2014 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 335 AM CDT MON APR 28 2014 THE MAIN FORECAST FOCUS WILL BE CONTINUED PRECIP CHANCES TODAY AND TONIGHT. WATER VAPOR IMAGERY THIS MORNING SHOWS THE WELL-DEFINED MID-LEVEL CYCLONE OVER NEBRASKA...WITH MOISTURE ROTATING NORTHWARD ON THE EASTERN FLANK OF THE SYSTEM...AND THE STRONGER CONVECTION WELL TO THE SOUTHEAST. THE CURRENT BAND OF RAIN CONTINUES TO LIFT ACROSS THE NORTHERN FORECAST AREA...WITH A BREAK TO THE SOUTH. BASED ON SFC OBS...SOME MIXED PRECIP MAY BE OCCURRING FROM NC ND INTO THE DVL BASIN. MORE RAIN CONTINUES TO DEVELOP ACROSS S MN/IOWA WHICH WILL LIFT TO THE NORTH AND WEST TODAY BRINGING WIDESPREAD RAINFALL TO THE REGION...WITH ADDITIONAL AMOUNTS OVER AN INCH POSSIBLE. THE AREA MOST LIKELY TO MISS OUT ON THE MAJORITY OF THE PRECIP WILL BE UP TOWARDS THE LAKE OF THE WOODS AREA...WITH THE MODEL CONSENSUS SUGGESTING THE HEAVIEST PRECIP FROM THE NORTHERN VALLEY SOUTHEAST INTO CENTRAL MN. VERY DRY AIR IS STILL IN PLACE UP TOWARDS FLAG ISLAND...SO THERE COULD BE A SHARP CUT-OFF IN PRECIP UP IN THIS AREA...WITH EVEN SOME DRYING FROM THE NORTHEAST LATE IN THE DAY. SO POP TRENDS WILL NEED TO BE FINE-TUNED IN LATER UPDATES. WINDS WILL BE BRISK FROM THE EAST...WITH TEMPS NOT MOVING MUCH TODAY WITH THE WIDESPREAD PRECIP AND CLOUDS. BY TONIGHT...AN UPPER JET/SHORTWAVE WILL NOSE INTO THE OHIO VALLEY...SHUNTING THE BETTER MOISTURE EASTWARD. AT THE SAME TIME...DRY AIR WILL WORK IN FROM THE NORTHEAST. PRECIP SHOULD END TO THE NORTH WITH SOME LIGHT PRECIP REMAINING FARTHER SOUTH. AS TEMPS COOL...PRECIP COULD MIX WITH OR CHANGE TO SNOW...WITH PERHAPS SOME LIGHT ACCUMULATIONS IN AREAS. TUESDAY LOOKS TO BE DRY OVER MUCH OF THE AREA WITH NORTHERLY FLOW. THE POSSIBLE EXCEPTION COULD BE ALONG THE SD BORDER INTO WC MN CLOSER TO THE LOW. WITH SOME SUN...TEMPS COULD CREEP UP TOWARDS 50...ALTHOUGH WINDS WILL REMAIN ON THE STRONG SIDE WITH COLD ADVECTION. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 335 AM CDT MON APR 28 2014 AS THE STACKED LOW PRESSURE SYSTEM SLOWLY PUSHES TOWARDS THE GREAT LAKES TUES NIGHT/WEDNESDAY AND SHORTWAVE ENERGY ROTATES AROUND THE CIRCULATION...PRECIP CHANCES WILL INCREASE FROM THE WEST. BY THIS TIME...THE BETTER LOW-LEVEL MOISTURE TRANSPORT WILL BE WELL EAST...SO TOTALS WOULD BE LIGHT. THE GFS IS A BIT WETTER AND BRINGS THE PRECIP FARTHER WEST...WHILE THE ECMWF KEEPS MOST OF THE PRECIP IN MN. IT MAY BE JUST COLD ENOUGH FOR SOME SNOW TUES NIGHT INTO WEDNESDAY...BUT ACCUMULATIONS WOULD BE LIGHT. WITH THE UPPER PATTERN CHANGING LITTLE...WEDNESDAY WILL BE ANOTHER COOL DAY WITH HIGHS IN THE 40S AND A TIGHT SFC GRADIENT KEEPING WINDS QUITE BREEZY FROM THE NORTH. FOR THURSDAY THROUGH SUNDAY...EXPECT THE CONTINUATION OF TEMPS BELOW NORMAL ALONG WITH PERIODIC CHANCES FOR RAIN SHOWERS. THERE COULD EVEN BE SOME SNOW MIXING IN AT TIMES OVERNIGHT...BUT OVERALL ANY PRECIP SHOULD REMAIN LIQUID. ANY PRECIP SHOULD ALSO BE LIGHT...WITH DEEPER MOISTURE WELL TO OUR SOUTH. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1140 PM CDT SUN APR 27 2014 THE FIRST BATCH OF RAIN IS MOVING NORTHWARD ACROSS THE REGION. EXPECT A BRIEF BREAK IN ACTIVITY SOMETIME DURING THE OVERNIGHT AND/OR EARLY MORNING HOURS. A SECOND BATCH OF RAIN WILL THEN EXPAND INTO A MAJORITY OF THE REGION SOMETIME AFTER SUNRISE MONDAY MORNING. ATTEMPTED TO ADD THIS DETAIL TO THE FORECAST. CIGS WILL CONTINUE TO BE TRICKY AS MOST GUIDANCE IS TOO LOW (BECAUSE OF THE LOW LEVEL EASTERLY FLOW FROM A DRY AIRMASS). RAP GUIDANCE APPEARS TO HAVE THE BEST IDEA THAT CURRENT CONDITIONS WILL PREVAIL THROUGH THE PERIOD...WITH POSSIBLE LOWER CIGS AS PRECIP RATES INCREASE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...MAKOWSKI LONG TERM...DK/MAKOWSKI AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1140 PM CDT SUN APR 27 2014 .UPDATE... ISSUED AT 933 PM CDT SUN APR 27 2014 FORECAST IS UNFOLDING AS EXPECTED. THE ONLY UPDATE WILL BE TO INDICATE A BRIEF BREAK IN ACTIVITY WITH 30% POPS. THE REGION WILL REMAIN WITHIN THE TROWAL (WHICH WILL GRADUALLY LIFT NORTH OVERNIGHT). WE KNOW THAT RAIN WILL OCCUR WITHIN THIS FEATURE...AND ALL AREAS WILL RECEIVE RAINFALL. THE HARD PART IS ATTEMPTING TO FORECAST EXACTLY WHEN AND WHERE WAVES ROTATING AROUND THE MAIN UPPER LOW WILL INFLUENCE AREAS WITHIN THE TROWAL. THE HRRR DID A GOOD JOB LAST NIGHT...AND WILL FOLLOW AS GUIDANCE FOR TONIGHT. THE RAIN ACROSS THE SOUTHERN FA WILL LIFT NORTH OVERNIGHT...AND ANTICIPATE A BREAK IN ACTIVITY ONCE THIS ACTIVITY MOVES TO THE NORTH. ADJUSTED POPS FOR THIS THINKING. THE NEXT WAVE...OR AREA OF FORCING...IS ASSOCIATED WITH THE ACTIVITY JUST ENTERING SOUTHERN IOWA. THIS ACTIVITY SHOULD EXPAND TO THE NORTHWEST OVERNIGHT...ENTERING WEST CENTRAL MINNESOTA 10Z-12Z...THEN EXPANDING INTO MUCH OF THE FA AFTER 12Z MONDAY MORNING (CONTINUING THROUGH MUCH OF THE DAY...STARTING TO DRY FROM THE NORTHEAST BY LATE AFTERNOON). && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 343 PM CDT SUN APR 27 2014 CHALLENGES INCLUDE WINDS LATE THIS AFTERNOON AND EVENING AND THEN PRECIP CHANCES/TYPE/AMOUNTS THROUGH THE REMAINDER OF THE FORECAST PERIOD. WILL USE RAP/HRRR FOR THE NEXT 6 TO 12 HOURS AND THEN TRANSITION TO A GLOBAL MODEL BLEND THEREAFTER AS GFS/NAM/ECMWF/ GEM ARE IN RELATIVELY GOOD AGREEMENT. IN THE NEAR TERM...WILL LET WIND ADVISORY CONTINUE UNTIL 7 PM CDT. MOST AREAS WON/T HIT CRITERIA...BUT FINALLY STARTING TO SEE SOME MORE WIDESPREAD OBSERVATIONS AT OR ABOVE 30 MPH. 20 UTC WATER VAPOR LOOP SHOWS PRIMARY VORTICITY MAXIMA ACROSS WESTERN KS WITH A STRONG SHORT-WAVE ROTATING OUT OF ITS BASE. STRONG WARM AIR AND MOISTURE ADVECTION (PWATS TO ONE INCH) ALONG THE 850 HPA SFC THIS EVENING AND OVERNIGHT...COMBINED WITH DIVERGENT FLOW ALOFT WILL RESULT IN INCREASING SHOWERS MOVING FROM SOUTH TO NORTH. ADDED THUNDER BACK INTO THE FORECAST ACROSS THE SOUTH THIS EVENING WITH ISOLATED LIGHTNING STRIKES ALONG THE ND/SD BORDER. INSTABILITY IS MINIMAL...BUT SPC MESOANALYSIS SHOWS A COUPLE HUNDRED JOULES OF MOST UNSTABLE CAPE. THERMAL PROFILES WARM ENOUGH TONIGHT FOR ALL RAIN...BUT COULD SEE A FEW FLAKES IN THE MIX. WILL LIFT CATEGORICAL POPS TO THE NORTH TONIGHT AND MONDAY. MONDAY WILL BE CLOUDY AND COOL WITH PERIODS OF LIGHT TO MODERATE RAIN SHOWERS. TEMPERATURES WILL RISE INTO THE UPPER 30S TO MID 40S WITH PERSISTENT BREEZY EASTERLY WIND. 850 HPA TEMPERATURES BEGIN TO FALL BELOW FREEZING MONDAY NIGHT WITH MOST OF THE COLUMN BELOW 0 C BY TUESDAY MORNING EXCEPT THE NEAR SFC LAYER. PTYPE WILL DEPEND HEAVILY ON SFC TEMPERATURES...BUT WITH FORECAST VALUES PLUS OR MINUS A FEW DEGREES AROUND FREEZING MONDAY NIGHT...WILL KEEP A RAIN/SNOW MIX IN THE WEATHER GRIDS. NOT REALLY EXPECTING MUCH ACCUMULATION AS MOST SNOW THAT DOES FALL SHOULD MELT ON CONTACT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 343 PM CDT SUN APR 27 2014 STRONG DRYING WILL WORK ITS WAY SOUTH ON TUESDAY AS THE LOW PRESSURE SYSTEM SCOOTS ACROSS IA INTO WI. SHOULD SEE A BREAK IN PRECIP...ESPECIALLY FOR THE CENTRAL AND NORTHERN FORECAST AREA. COULD EVEN SEE SOME PEAKS OF SUN. PTYPE SHOULD BE MOSTLY RAIN WITH HIGHS RISING INTO THE MID TO UPPER 40S. WINDS WILL REMAIN BREEZY AND SHIFT TO THE NORTH. WRAP AROUND PRECIP WILL RETURN WEDNESDAY AS THE LOW WOBBLES ACROSS WI WITH A GREATER CHANCE FOR A RAIN/SNOW MIX OR EVEN ALL SNOW AT TIMES GIVEN A SATURATED SUB-FREEZING COLUMN. PTYPE WILL AGAIN DEPEND ON SFC TEMPERATURES WITH MINIMAL ACCUMULATIONS. WHEN ALL IS SAID AND DONE...LIQUID ACCUMULATIONS OVER THE 2 TO 3 DAY PERIOD WILL BE 1 TO 2 INCHES WITH LOCALLY HIGHER AMOUNTS IN HEAVIER SHOWERS OR THUNDERSTORMS. ANY SNOW ACCUMULATION SHOULD BE CONFINED MAINLY TO THE HIGHER TERRAIN ON EITHER SIDE OF THE VALLEY BUT ONLY AN INCH OR LESS. UPPER LOW AND SURFACE LOW WILL REMAIN OVER THE GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY WITH NORTH WINDS AND SPOTTY RAIN SHOWERS ALONG WITH CONTINUED WELL BELOW NORMAL TEMPERATURES. 12Z ECMWF/GFS ALL INDICATE 500 MB TROUGH TO REMAIN IN PLACE WITH NEXT SHORT WAVE DROPPING SOUTH INTO THE NRN PLAINS FRIDAY NIGHT-SATURDAY WITH ANOTHER CHANCE OF SHOWERS. NO HEAVY RAINFALL THIS PERIOD BUT AT LEAST A CHANCE FOR SHOWERS EACH DAY AND TEMPS REMAIN BELOW AVERAGE INTO THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1140 PM CDT SUN APR 27 2014 THE FIRST BATCH OF RAIN IS MOVING NORTHWARD ACROSS THE REGION. EXPECT A BRIEF BREAK IN ACTIVITY SOMETIME DURING THE OVERNIGHT AND/OR EARLY MORNING HOURS. A SECOND BATCH OF RAIN WILL THEN EXPAND INTO A MAJORITY OF THE REGION SOMETIME AFTER SUNRISE MONDAY MORNING. ATTEMPTED TO ADD THIS DETAIL TO THE FORECAST. CIGS WILL CONTINUE TO BE TRICKY AS MOST GUIDANCE IS TOO LOW (BECAUSE OF THE LOW LEVEL EASTERLY FLOW FROM A DRY AIRMASS). RAP GUIDANCE APPEARS TO HAVE THE BEST IDEA THAT CURRENT CONDITIONS WILL PREVAIL THROUGH THE PERIOD...WITH POSSIBLE LOWER CIGS AS PRECIP RATES INCREASE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...TG SHORT TERM...ROGERS LONG TERM...ROGERS/RIDDLE AVIATION...TG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
214 AM EDT MON APR 28 2014 .SYNOPSIS... A WET AND STORMY PATTERN WILL SET UP ACROSS THE AREA MONDAY THROUGH WEDNESDAY...FOLLOWED BY COOL AND DRIER HIGH PRESSURE BY THE END OF THE WEEK. && .NEAR TERM /THROUGH TODAY/... AS OF 2 AM...SCATTERED SHOWERS ACROSS NC HAVE BEEN ON A GENERAL DECREASING TREND OVER THE PAST COUPLE OF HOURS...SO HAVE GENERALLY FEATURED GRADUALLY WANING POPS AS THE CURRENT ACTIVITY LIFTS ACROSS THE FOOTHILLS AND PIEDMONT. HOWEVER...ADDITIONAL WARM SECTOR SHOWERS AND EVEN A TS OR TWO HAVE BEEN INITIATING OVER THE TN VALLEY IN REGION OF GENERAL WAA AND B.L. CONVERGENCE...SO SMALL POPS WILL BE RETAINED ACROSS THE FAR WESTERN MTNS THROUGH THE OVERNIGHT. DEWPOINTS IN THE 50S AND WIDESPREAD CIRRUS BLOW-OFF FROM TENN/MISS VALLEY CONVECTIVE COMPLEX WILL HOLD MIN TEMPS ABOUT 10-15 DEGREES ABOVE CLIMO THIS MORNING. AS OF 1010 PM EDT SUNDAY...BLENDED POPS ARE WORKING WELL AS SCATTERED LIGHT SHOWERS HAVE DEVELOPED OVER THE WESTERN ZONES...AND A FEW STRONGER STORMS HAVE DEVELOPED NOT TOO FAR UPSTREAM OF THE FORECAST AREA. POPS AND SKY COVER LOOK GOOD. AT 735 PM EDT SUNDAY...BLENDED A POP DERIVED FROM LOCAL CONVECTIVE ALLOWING MODELS AND THE OFFICIAL FORECAST TO GO WITH A SMALL AREA OF HIGH CHANCE AND LIKELY POPS FROM THE UPSTATE INTO THE SRN AND CENTRAL NC MTNS. THE 18 UTC NAM HAD A LITTLE BETTER ELEVATED CAPE ACROSS THIS AREA AND THE HRRR AND WRF-ARW ARE INCREASES CONVECTIVE COVERAGE OVER THIS AREA LATER TONIGHT. OTHERWISE...INCREASED SKY COVER AND MADE SOME MINOR TWEAKS TO THE REST OF THE GRIDS. AT 430 PM EDT SUNDAY...ADJUSTED SKY GRIDS TO ACCOUNT FOR ENCROACHING HIGH CLOUDS AS WELL AS A CU DECK THAT IS DEVELOPING ACROSS NE GA...THE SW NC MTNS AND THE WRN UPSTATE. SOME OF THE MESOSCALE MODELS BRING ELEVATED CONVECTION ACROSS THE FORECAST AREA OVERNIGHT AS THE LEADING EDGE OF THE ELEVATED MIXED LAYER WORKS IN FROM THE WEST. I DON/T SEE MUCH MUCAPE ON THE 18 UTC NAM...SO THINK MOST OF THE ACTIVITY WILL BE WEAK. I WON/T ADJUST THE OVERNIGHT GRIDS JUST YET..BUT I NEED TO RAMP UP POPS WITH SUBSEQUENT UPDATES. AT 200 PM EDT SUNDAY...A NEGATIVELY TILTED UPPER TROUGH WILL SLOWLY PROGRESS ACROSS THE SOUTHERN APPALACHIANS AND GREAT LAKES TONIGHT... WHILE A CLOSED UPPER LOW MOVES NE ACROSS THE GREAT PLAINS. THE RIDGE AXIS MOVES EAST OF THE MOUNTAINS ON MONDAY...WHILE THE UPPER LOW DRIFTS BACK SOUTH OVER THE PLAINS. ISENTROPIC UPGLIDE WILL SPREAD ACROSS THE UPPER SAVANNAH RIVER VALLEY AND SOUTHERN APPALACHIANS LATE THIS AFTERNOON AND THIS EVENING. INSTABILITY SHOULD BECOME SUFFICIENT FOR CONVECTION TO FORM BEFORE EVENING...HOWEVER NEITHER SHEAR NOR INSTABILITY APPEAR IMPRESSIVE. A BACK DOOR COLD FRONT WILL SETTLE SOUTH ACROSS WESTERN NC TONIGHT...REACHING THE SC BORDER EAST OF THE MOUNTAINS BY DAYBREAK. THE BOUNDARY WILL BECOME A FOCUS FOR CONVECTIVE ACTIVITY ON MONDAY...WHEN BETTER SHEAR AND INSTABILITY WILL BE PRESENT. SPC HAS OUR ENTIRE AREA IN A SLIGHT RISK FOR SEVERE WEATHER ON DAY TWO...MENTIONING AN ENVIRONMENT FAVORABLE FOR SUPERCELLS. THE AREA NORTH OF INTERSTATE 40 MAY REMAIN UNFAVORABLE FOR CONVECTION DURING THE DAYLIGHT HOURS ON MONDAY...AS COOL NE FLOW PREVAILS BEHIND THE FRONT...AND A CAP REMAINS AT AROUND 875 MB. WITH THE BEST GULF INFLOW STILL WELL TO THE WEST...EXCESSIVE RAINFALL IS NOT EXPECTED...HOWEVER INDIVIDUAL STORMS MAY PUT DOWN LOCALLY HEAVY RAINFALL. MINIMUM TEMPERATURES WILL BE WELL ABOVE NORMAL UNDER INCREASING CLOUDS COVER AND THE UPPER RIDGE. HIGH TEMPERATURES ON MONDAY WILL RUN SLIGHTLY ABOVE NORMAL...AS CLOUD COVERAGE OFFSETS THE INFLUENCE OF THE UPPER RIDGE. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... AS OF 235 PM SUNDAY...NOTHING IN THE NEW GUIDANCE TO CHANGE EARLIER THINKING THAT WE ARE ON A COLLISION COURSE WITH A VERY WET AND VERY STORMY PATTERN DURING THE LATE MONDAY TO WEDNESDAY TIME FRAME. IMPORTANT DETAILS SUCH AS THE TIMING OF ENHANCED SEVERE THUNDERSTORM THREATS...AND STORM TOTAL RAINFALL...STILL REMAIN IN DOUBT. ONE INTERESTING TREND OR POINT OF CONCERN IS BROUGHT TO LIGHT IN THE LATEST NAM MONDAY NIGHT AND EARLY TUESDAY MORNING. A WEDGE BOUNDARY OF SORTS IS INDICATED EVEN FARTHER SOUTH THAN PREVIOUS RUNS...DOWN CLOSER TO THE SC/NC BORDER. THE AIR MASS TO THE SOUTH OF THE BOUNDARY MIGHT BE FAIRLY RICH WITH BUOYANCY. THE SREF HAS A VERY HIGH PROBABILITY OF CAPE GREATER THAN 1000 J/KG LATE IN THE DAY...AND EVEN THE GENERALLY MORE CONSERVATIVE GFS HAS CAPE IN THE 1000 - 1500 J/KG RANGE. SHEAR AND SRH WILL INCREASE STEADILY THROUGH THE EVENING HOURS IN THE PRESENCE OF ADEQUATE BUOYANCY...THUS OUR CHANCES FOR ORGANIZED SEVERE THUNDERSTORMS WILL ALSO INCREASE. AGREE WITH THE EXPANSION OF THE DAY2 SLIGHT RISK FURTHER EAST IN THE NEW OUTLOOK. IF THE WEST TO EAST ORIENTED BOUNDARY REMAINS IN THE AREA...THIS COULD PROVIDE THE FOCUS FOR SEVERE STORMS AND TORNADIC ACTIVITY SOMEWHERE IN THE CAROLINAS WELL INTO THE OVERNIGHT HOURS. THERE IS ALSO THE CONCERN THAT SUPERCELLULAR CONVECTION MOVING IN FROM GEORGIA DURING THE EVENING WILL GET A SHOT OF INCREASED SHEAR AS IT INTERACTS WITH A BOUNDARY. AT THE SAME TIME...THE FRONTAL ZONE OF HEAVIER RAIN WILL MOVE INTO THE MOUNTAINS. CONFIDENCE IN THE TIMING OF ANY MESOSCALE CONVECTIVE SYSTEMS GOES DOWN AFTER LATE MONDAY NIGHT...BUT WE WILL RETAIN A FAVORABLE COMBINATION OF SHEAR AND INSTABILITY TO KEEP A THREAT OF SEVERE STORMS THROUGH TUESDAY ACROSS MOST OF THE FCST AREA...WITH PERHAPS THE EXCEPTION OF THE WRN NC MTNS...AND INTO WEDNESDAY EAST OF THE MOUNTAINS. ONE MIGHT EXPECT A BIT OF A LULL OR RECHARGE PERIOD TUESDAY MORNING...BEFORE MORE ORGANIZED SEVERE WEATHER AFFECTS THE REGION TUESDAY AFTERNOON AND EVENING WITH DIURNAL ENHANCEMENT. CAPE PROFILES SUGGEST THAT WE MIGHT HAVE A BIT LESS OF A CHANCE OF SUPERCELLS AND THE LIKE...BECAUSE OF CONVECTIVE DEBRIS/ OVERTURNING...BUT STILL ENOUGH OF A TORNADO THREAT FOR CONTINUED CONCERN BECAUSE OF THE SHEAR. ADDITIONAL DETAILS WILL HOPEFULLY COME MORE INTO FOCUS WITH SUBSEQUENT FCST PACKAGES. AT ANY RATE...PRECIP CHANCES RAMP UP STEADILY FROM THE WEST INTO THE LIKELY TO CATEGORICAL RANGE MONDAY NIGHT AND INTO TUESDAY AND TUESDAY NIGHT. THE LATEST QPF GUIDANCE FROM WPC IS VERY TROUBLESOME. ON THE ONE HAND...ANOMALY GUIDANCE DOES NOT SHOW ANYTHING OVERLY ALARMING WITH REGARD TO PRECIPITABLE WATER...BUT ON THE OTHER HAND THE SLOW MOVING NATURE OF THE COLD FRONT WILL PERMIT WAVES OF MODERATE TO HEAVY RAIN STARTING EARLY TUESDAY MORNING...AND CONTINUING INTO WEDNESDAY. UNLESS THERE IS SOME CHANGE IN THINKING... THE NEED FOR A FLOOD WATCH IS NEARLY A FOREGONE CONCLUSION...BUT THE MAIN THREAT OF FLOODING DOES NOT RAMP UP UNTIL DURING THE DAY ON TUESDAY BASED ON THE QPF BREAKDOWN. SINCE THIS IS THE 4TH FCST PERIOD AND WE HAVE SOME TIME TO GAIN MORE CONFIDENCE... WILL HOLD OFF ON A FLOOD WATCH FOR ONE MORE FCST CYCLE. MODEL GUIDANCE SHOWS THE FRONT CROSSING THE FCST AREA WEDNESDAY EVENING AND THAT SHOULD BRING AN END TO MOST OF THE PRECIP...WITH SOME LINGERING SHOWERS POSSIBLE ON THE TN BORDER OVER THE NRN MTNS. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 1 PM SUNDAY...EXPANSIVE UPPER TROUGH WILL REMAIN OVER THE ERN CONUS THROUGH THE MEDIUM RANGE...WITH THE FLOW EVENTUALLY FLATTENING BY THE END OF NEXT WEEKEND. FAIRLY UNSETTLED CONDITIONS WILL CONTINUE ACRS THE SOUTHEAST REGION UNTIL THAT TIME. FRONTAL BOUNDARY LAYS OUT JUST OFFSHORE FRIDAY. GFS/EC/GEM AGREE ON A SHORTWAVE ROUNDING THE LARGER SCALE TROUGH AND BRINGING A WAVE OUT OF THE GULF OF MEXICO ALONG THE FRONT. THEY DISAGREE HOWEVER ON THE TIMING OF THIS EVENT. 12Z GFS/GEM DEVELOP ONLY A WEAK WAVE FRIDAY...AND HAVE A LOW IMPACT ON OUR CWFA WITH VERY LITTLE QPF. ORIENTATION OF THE FRONT ON THE 00Z EC LEADS IT TO DEVELOP A STRONGER WAVE AND BRING ANOTHER ROUND OF PRECIP TO THE PIEDMONT FRIDAY NIGHT AND SATURDAY. GFS CONCURRENTLY DEVELOPS SHOWERS IN THE MTNS AS IT BRINGS THE WAVE ACRS EARLY SATURDAY...WITH ADDITIONAL NW FLOW PRECIP CONTINUING INTO EARLY SUNDAY. THIS IS A PLAUSIBLE SCENARIO THOUGH IT IS THE ONLY MODEL SHOWING IT. QPF FROM THIS ACTIVITY IS NOTABLE BUT NOT HIGH ENOUGH FOR CONCERN...SO IT WILL BE MINIMALLY REFLECTED IN THE FCST. IN FACT...NCEP/CMC ENSEMBLES GIVE LITTLE SUPPORT TO A WETTER EC-LIKE SOLUTION SO POPS WILL BE KEPT ON THE LOW SIDE FOR THE POTENTIAL FRONTAL WAVE PRECIP...ALONG WITH QPF. AFTER ABV NORMAL TEMPS THU...TEMPS RETURN TO AROUND NORMAL FRI INTO SAT WITH CLOUD COVER. LOWS SUNDAY MRNG SHOULD BE A COUPLE CATEGORIES BELOW NORMAL BUT TEMPS REBOUND SUNDAY UNDER CLEARER SKIES. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AT KCLT...THE FIRST 12 HOURS OR SO OF THE FORECAST IS RELATIVELY STRAIGHT FORWARD...WITH PRIMARILY HIGH/MID-LEVEL CLOUDS EXPECTED ALONG WITH SOUTH WINDS. HOWEVER...UNCERTAINTY INCREASES SUBSTANTIALLY FROM AFTERNOON ONWARD. A WEAK BACK DOOR FRONT WILL DROP SLOWLY SOUTH ACROSS THE PIEDMONT LATER THIS MORNING (WITH WINDS TURNING TO THE E/NE NORTH OF THE FRONT) BEFORE STALLING AND EVENTUALLY LIFTING NORTH...BUT IT IS VERY UNCERTAIN AS TO WHETHER THIS WILL MAKE IT AS FAR SOUTH AS KCLT. CERTAINLY A CONSENSUS OF FORECAST GUIDANCE WOULD KEEP THE FRONT NORTH OF THE TERMINAL...AND WE HAVE SIDED WITH THIS CONSENSUS. WHEREVER THE FRONT SETS UP...IT IS EXPECTED TO PROVIDE A FOCUS FOR THUNDERSTORM DEVELOPMENT THIS AFTERNOON...AS THE ATMOSPHERE IS EXPECTED TO BECOME MODERATELY UNSTABLE. HOWEVER...THE DEGREE OF COVERAGE AND TIMING OF THIS IS STILL QUITE UNCERTAIN. FOR NOW...PROB30S HAVE BEEN INTRODUCED FOR THE 18-20Z TIME FRAME...WITH A TEMPO THROUGH 00Z. TS CHANCES WILL CONTINUE THROUGH THE END OF THE PERIOD. ELSEWHERE...DESPITE INCREASING LOW LEVEL MOISTURE...EXTENSIVE HIGH CLOUDS ASSOCIATED WITH MISS/TENN VALLEY CONVECTION IS EXPECTED TO KEEP COVERAGE OF FOG LIMITED THIS MORNING (EXCEPT PERHAPS ACROSS THE MOUNTAIN VALLEYS WEST OF KAVL)...BUT HAVE INCLUDED A PERIOD OF MVFR FOG AT KAND. A BACKDOOR COLD FRONT IS EXPECTED TO PUSH THROUGH KHKY AROUND SUNRISE...AND MVFR CIGS ARE EXPECTED TO DEVELOP THERE BY MID-MORNING OR SO. OTHERWISE...THE PRIMARY FORECAST CHALLENGE IS TIMING AND OVERALL COVERAGE OF THUNDERSTORMS LATER TODAY. CHANCES SHOULD GRADUALLY INCREASE THROUGHOUT THE DAY...AND HAVE RESERVED CATEGORICAL SHOWERS FOR VERY LATE THIS AFTERNOON AND THIS EVENING... WITH VCTS FAVORED EARLIER IN THE PERIOD. OUTLOOK...PERIODS OF NUMEROUS/WIDESPREAD SHOWERS AND THUNDERSTORMS AND ASSOCIATED RESTRICTION ARE EXPECTED FROM EARLY TUESDAY THROUGH AT LEAST WEDNESDAY. DRIER WEATHER IS ANTICIPATED FOR LATE WEEK INTO THE WEEKEND. CONFIDENCE TABLE... 06-12Z 12-18Z 18-24Z 00-06Z KCLT HIGH 100% HIGH 93% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 93% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 98% HIGH 100% HIGH 98% KHKY HIGH 100% MED 79% HIGH 85% HIGH 93% KGMU HIGH 100% HIGH 93% HIGH 100% HIGH 100% KAND HIGH 97% HIGH 94% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...SBK NEAR TERM...JAT/JDL/MCAVOY SHORT TERM...PM LONG TERM...WIMBERLEY AVIATION...JDL
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
344 AM CDT MON APR 28 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 344 AM CDT MON APR 28 2014 CURRENT WATER VAPOR IMAGERY SHOWS THE LOW IN THE MID LEVELS OF THE ATMOSPHERE SPINNING AWAY RIGHT IN THE MIDDLE OF NEBRASKA...WITH THE WELL ADVERTISED DRY SLOT ALOFT NOSING UP IN FRONT OF IT AND ENCOMPASSING MUCH OF OUR FORECAST AREA. THE MOST PRONOUNCED DRYING ALOFT IS ALONG THE I 29 CORRIDOR CURRENTLY. MODEL CONSENSUS IS GOOD IN PROGGING THE LOW SLOWLY EASTWARD TOWARD SOUTHEAST IA BY VERY LATE TONIGHT. THE SURFACE LOW FOLLOWS SUIT...AND IT LOOKS LIKE OUR ENTIRE FORECAST AREA WILL BE PLACED NORTH OF THE WARM FRONT THROUGH TODAY AND TONIGHT. THE BEST CHANCES FOR WIDESPREAD BENEFICIAL RAINFALL TODAY WILL BE BEHIND THE INVERTED TROUGH WHICH WILL BE CONFINED TO OUR FAR WESTERN ZONES APPROACHING CENTRAL SD. THE REST OF OUR AREA WILL SEE LESS NUMEROUS SHOWERS AND RAINFALL. BUT THERE IS ENOUGH ELEVATED INSTABILITY TO POP A THUNDERSTORM OR TWO ALMOST AT ANYTIME THROUGHOUT THE ENTIRE DAY...ESPECIALLY WHEN A MICROSCALE AREA OF WARM AIR ADVECTION DECIDES TO MOVE NORTHWARD WHICH THE MODELS CANNOT HANDLE VERY WELL ON THAT SCALE. INTERESTINGLY...BOTH THE GFS AND GEM PAINT A BROAD STRIPE OF DECENT QPF THIS AFTERNOON JUST NORTH OF THE WARM FRONT FROM SIOUX CITY TO STORM LAKE. IN ADDITION...THE PAST FEW RUNS OF THE HRRR ARE ALSO SHOWING THE POSSIBILITY OF DECENT CONVECTION IN THOSE AREAS AGAIN DUE TO THE PROXIMITY OF THE WARM FRONT JUST TO THE SOUTH. AT THIS TIME...IT LOOKS TOO STABLE FOR MUCH IN THE WAY OF SEVERE WEATHER...AND ALSO THE WIND SHEAR IS NOT REAL GREAT FROM SIOUX CITY TO STORM LAKE AS THE ENTIRE LOWEST 3 KILOMETERS HAS A WIND DIRECTION OUT OF THE EAST. ONE THING TO WATCH FOR HOWEVER IS IF A ROGUE SEVERE STORM WHICH BLOWS UP FURTHER TO THE SOUTHEAST NUDGES INTO THOSE AREAS BEFORE WEAKENING. TO THE NORTH...KEPT THE COVERAGE OF POPS IN THE SCATTERED CATEGORY THIS AFTERNOON ALONG THE I 29 CORRIDOR WHERE THE DRY SLOT ALOFT HAS THE MOST IMPACT. BUT OTHER AREAS MAY START TO FILL IN MORE WITH RAINFALL IN OUR FAR EAST AND INTO THE JAMES RIVER VALLEY FROM THE WEST AS MOISTURE PROGS SATURATE UP BETTER ALOFT. FEEL THERE IS NO NEED FOR A WIND ADVISORY TODAY AS SOUNDINGS ONLY MIX TO ABOUT 925-900MB AREA WIDE. WINDS IN THAT LAYER ARE STOUT... AVERAGING 30 TO 35 KNOTS...BUT USUALLY IT TAKES A LITTLE MORE THAN THAT TO WARRANT A WIND ADVISORY IN OUR AREA...CLOSER TO 40 KNOTS. HOWEVER TONIGHT ON THE BACK SIDE OF THE LOW...OUR FAR SOUTHWEST ZONES MAY GET CLOSE TO ADVISORY CRITERIA AFTER MIDNIGHT. MUCH OF OUR FORECAST AREA TONIGHT IS WELL PLACED IN THE UPPER LEFT QUADRANT OF THE LOW TRACK TO RECEIVE PRECIP. THERE IS EVEN SOME WEAK TROWALING IN THE 290-295K LAYER NUDGING INTO OUR AREA FROM THE EAST...AND SATURATION LOOKS TO BE IN NO SHORT SUPPLY FROM THE SURFACE TO AROUND 500MB. IN THE EVENING...AGAIN THE I 29 CORRIDOR MAY NOT RECEIVE MUCH RAIN...BUT PRECIP WILL FILL INTO THAT AREA OVERNIGHT. CONCERNING TEMPERATURES...WITH A FEW BREAKS POSSIBLE NEAR THE WARM FRONT... AREAS FROM YANKTON TO STORM LAKE AND SOUTHWARD SHOULD HIT 60 TO 65...PROGRESSIVELY COOLING OFF HEADING NORTHWARD. TONIGHT IS TRICKY...AND HAD TO ADD IN A SNOW MIX TO OUR NORTHERN AND WESTERN ZONES AS SURFACE TEMPERATURES COOL INTO THE MID 30S IN THOSE AREAS COUPLED WITH SUB ZERO 850MB TEMPERATURES. USED THE MODEL CONSENSUS 850MB -2 DEGREE C AND 925MB ZERO DEGREE C ISOTHERMS FOR THE RAIN AND SNOW LINES...COUPLED WITH TEMPERATURES NEAR 35. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 344 AM CDT MON APR 28 2014 TUESDAY WILL START FAIRLY RAINY OVER THE AREA...THOUGH AMOUNTS SHOULD BE LESS THAN A QUARTER INCH FOR THE DAY. DRYING WILL BEGIN FROM THE NORTH/NORTHEAST DURING THE AFTERNOON OVER THE WESTERN PART OF THE FORECAST AREA AS SOME SUBSIDENCE SPREADS IN FROM THE NORTH/ NORTHEAST BETWEEN LOBES ROTATING AROUND THE UPPER LOW TO THE EAST. FOR NOW WILL KEEP SOME VERY MINIMAL POPS IN THE WEST FOR TUESDAY NIGHT...WHILE ONLY SHAVING POPS TO LOW LIKELIES ALONG OUR EASTERN EDGE IN MN AND IA. FOR NOW AM GOING FOR ALL OF THIS PRECIPITATION TO BE LIGHT RAIN EXCEPT MAYBE SOME MODERATE RAIN LINGERING TUESDAY MORNING IN THE EAST...MAYBE WITH A BIT OF WET SNOW MIXED IN WEST AND NORTH EARLY MORNING BUT NO ACCUMULATION. FOR TUESDAY NIGHT...THOUGH TEMPERATURES ALOFT WILL BE MARGINAL FOR A LITTLE MIXED SNOW AGAIN... THERE MAY BE NO PRECIPITATION AT ALL IN THE WEST WHICH WOULD HAVE THE BETTER SHOT AT SOME SNOW. SURFACE AND NEAR SURFACE TEMPERATURES WILL LIKELY BE A BIT TOO WARM WITH THE LIGHTER NATURE OF PRECIPITATION...IF THERE IS ANY AROUND IN THE FIRST PLACE...AND DYNAMIC COOLING WILL BE NIL. TO THE EAST...THE DEEPER MOIST AIR SHOULD PRECLUDE ENOUGH COOLING TO GET SNOW TO THE SURFACE...AND EVEN THERE THE PRECIPITATION SHOULD BE PRETTY LIGHT. TEMPERATURES WILL NOT BE SHOWING A LOT OF SPREAD WITH 40S HIGHS AND 30S LOWS. IT WILL STILL BE WINDY TUESDAY BUT EXPECT WINDS WILL STAY BELOW ADVISORY CRITERIA. WEDNESDAY WILL BRING THE NEXT LOBE ROTATING OVER THE AREA AND A RESURGENCE OF LIGHT RAIN WEST/SOUTHWESTWARD AGAIN. TEMPERATURES AGAIN WILL CLIMB INTO THE 40S AND IT WILL BE WINDY AGAIN. IT COULD EVEN BE SLIGHTLY WINDIER THAN TUESDAY WITH THE LOBE PASSING OVER THE AREA. THURSDAY WILL BRING THE SYSTEM STARTING TO MOVE SLOWLY EAST OF THE AREA AND WILL KEEP LIGHT RAIN POPS IN THE CHANCE CATEGORY. WEDNESDAY NIGHT LOWS SHOULD BE IN THE 30S AGAIN...THOUGH IT MAY BE A DEGREE OR TWO LESS COOL THERE WITH MODELS HINTING AT VERY SLIGHT LOW LEVEL WARMING. WITH LESSER PRECIPITATION COVERAGE...THURSDAY DAY TEMPERATURES ARE EXPECTED TO BE A TAD LESS COOL...UPPER 40S TO LOWER 50S FOR HIGHS. THIS PROCESS WILL CONTINUE ON FRIDAY...REMEMBER THE SLOWNESS OF THIS SYSTEM...BUT POPS WILL BE PRETTY LOW WITH PRECIPITATION CONFINED MAINLY TO EAST OF FSD. 50 TO 55 LOOKS RIGHT FOR HIGHS FRIDAY. THE WEEKEND SHOULD BE A LITTLE WARMER YET...BUT STILL BELOW NORMAL...AHEAD OF A CANADIAN WAVE APPROACHING IN NORTHWEST FLOW BEHIND THE CURRENT SYSTEM. WILL GO WITH THE EXTENDED GUIDANCE GRIDS OF SHOWER CHANCE PEAKING ABOUT SATURDAY NIGHT. THIS SEEMS TO BE THE BEST PLAN FOR NOW ON EITHER THE GFS OR EC SOLUTION. THE EC HAS STRONGER RIDGING BETWEEN SYSTEMS THAN THE GFS AND WOULD BRING TEMPERATURES A LITTLE CLOSER TO NORMAL FOR THE WEEKEND...BUT THE LIGHT SHOWER THREAT IS STILL THERE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1120 PM CDT SUN APR 27 2014 WIDESPREAD CEILINGS AROUND 500 TO 1500 WILL BE THE MAIN STORY THROUGH THE PERIOD. SOME VFR CEILINGS NEAR THE MISSOURI VALLEY WILL QUICKLY GIVE WAY TO LOW STRATUS THROUGH THE NEXT FEW HOURS...WITH SHOWERS AND THUNDERSTORMS PUSHING INTO SOUTH CENTRAL SD INTO THE EARLY MORNING HOURS. CEILINGS AND VISIBILITY WILL FURTHER DROP IN ANY SHOWERS AND STORMS. STRATUS STICKS AROUND THROUGHOUT THE DAY ON MONDAY...WITH THE ONLY POTENTIAL LIFTING OF CEILINGS ABOVE 3000 EXPECTED NEAR THE MISSOURI RIVER ONCE AGAIN. ADDITIONAL SHOWER ACTIVITY SPREADS FROM WEST TO EAST MAINLY 15Z THROUGH THE END OF THE TAF PERIOD. WINDS WILL REMAIN GENERALLY EASTERLY AND BREEZY AROUND 15 TO 25 KT WITH GUSTS TO 32 KT...BUT WILL BEGIN TO SHIFT NORTHEAST THEN NORTH ACROSS OUR WESTERN HALF AFTER 21Z. A LULL IN THE WINDS WILL DEVELOP ON MONDAY NEAR THE MISSOURI VALLEY. ISOLATED STRONGER OR SEVERE STORMS ARE ALSO POSSIBLE MONDAY AFTERNOON AND EVENING MAINLY NEAR THE MISSOURI VALLEY...WITH HAIL AND GUSTY WINDS POSSIBLE. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...MJ LONG TERM... AVIATION...
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1152 PM MDT SUN APR 27 2014 .UPDATE... ISSUED AT 1147 PM MDT SUN APR 27 2014 RAIN HAS CHANGED TO SNOW ACROSS NORTHWESTERN SOUTH DAKOTA. EXPECT SNOWFALL TO CONTINUE INTO MONDAY MORNING WITH AMOUNTS OF 2 TO 5 INCHES. THUS DELAYED THE WIND ADVISORY UNTIL 18Z AND STARTED A WINTER WEATHER ADVISORY FOR NORTHWESTERN SOUTH DAKOTA THAT GOES UNTIL 18Z. UPDATE ISSUED AT 939 PM MDT SUN APR 27 2014 DECIDED TO START HIGH WIND WARNING SINCE THE AREA IN THE WATCH WAS ALREADY IN WARNING CRITERIA...KRAP GUST TO 52KT AT 0202Z. LOOKING AT LATEST HI RES MODEL GUIDANCE...HRRR AND RAP...LOOKS LIKE 30 TO 40 MPH WINDS WILL CONTINUE THRU THE NIGHT BEFORE REALLY PICKING UP BY 13Z MONDAY. SEEING VERY STRONG DOWNSLOPE WINDS FROM THE BLACK HILLS IN THE HIGH WIND WARNING AREA. COULD SEE SOME LIGHTER WINDS OVERNIGHT...HOWEVER SINCE WE WERE ALREADY HAVING HIGH WINDS AND CONFIDENCE IN HIGH WINDS FOR MONDAY AND TUESDAY WERE HIGH...DECIDED TO GO WITH THE WARNING. UPDATE ISSUED AT 822 PM MDT SUN APR 27 2014 DECIDED TO PUT OUT A WINTER WEATHER ADVISORY FOR SNOW FOR SHANNON AND BENNETT COUNTIES. MADE A FEW CALLS AND LOOKING AT WEBCAMS MARTIN ALREADY HAD AN INCH AND PINE RIDGE HAD A COUPLE INCHES. LATEST RAP MODEL AND HRRR BOTH INDICATE A TROWAL SETTING UP OVER THIS AREA TONIGHT. EXPECT A BAND OF HEAVY SNOW WITH AMOUNTS OF 2 TO 5 INCHES FOR THIS AREA. ONLY HAVE THE ADVISORY TIL 12Z...BUT SNOW MAY CONTINUE A BIT LONGER. ONCE THE SNOW STOPS THE WINDS WILL START IN THIS AREA SO KEPT WIND ADVISORY BEGINNING AT 12Z. NEXT SHIFT MAY HAVE TO ADJUST THE TIMING DEPENDING ON THE SNOWFALL. UPDATE ISSUED AT 640 PM MDT SUN APR 27 2014 LATEST HRRR MODEL AND SURFACE ANALYSIS SHOWS A LEE MESO-LOW OVER CENTRAL CUSTER COUNTY. THE ISOBARS SHOW A TIGHT GRADIENT OVER WESTERN FALL RIVER COUNTY AND ALONG THE EASTERN FOOTHILLS FROM RAPID CITY TO HERMOSA AND ABOUT 60 MILES EAST ONTO THE PLAINS. THIS FEATURE IS PROGGED TO CONTINUE THROUGH 02Z-03Z THIS EVENING. THE RESULT WILL BE A BRIEF PERIOD OF GUSTY NORTHWEST WINDS OF 35 TO 40 MPH AND GUSTS UP TO 55 MPH. SINCE THIS FEATURE IS VERY LOCALIZED AND WILL BE SHORT LIVED WITH WINDS DIMINISHING AFTER 03Z BEFORE INCREASING AGAIN EARLY MONDAY MORNING...THOUGHT IT WOULD BE BEST COVERED WITH A SPECIAL WEATHER STATEMENT INSTEAD OF GOING WITH A WIND ADVISORY OR HIGH WIND WARNING. OTHERWISE THE FORECAST IS ON TRACK...AM WATCHING THE NORTHERN HILLS CLOSELY SINCE SOME AREAS HAVE ALREADY PICKED UP A FEW INCHES OF SNOW. HOWEVER WINTER STORM WARNING AT THE HIGHER ELEVATIONS AND WINTER WEATHER ADVISORY AROUND SPEARFISH LOOK TO BE GOOD AT THIS TIME. && .SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT ISSUED AT 219 PM MDT SUN APR 27 2014 CURRENT SURFACE ANALYSIS PLACES LOW OVER NWRN KANSAS/SWRN NEBRASKA...WHILE UPPER LEVEL ANALYSIS INDICATES LOW HAS BECOME STACKED. TWO MAIN AREAS OF PRECIP HAVE DEVELOPED OVER THE CWA WITH THE FIRST ONE ORIENTATED N/S ALONG THE WRN SD BORDER ALONG AREA OF STRONG MID-LEVEL FRONTOGENESIS WHILE SECONDARY AREA OF PRIMARILY THUNDERSTORMS CONTINUES TO PUSH W/NWRLY NEAR NOSE OF JET STREAK. FOR THE REST OF THIS AFTERNOON INTO TONIGHT...A POTPOURRI OF WEATHER TYPES ARE EXPECTED AS STRONG LOW PRESSURE SYSTEM CREEPS ITS WAY THROUGH THE REGION. LATEST GUIDANCE KEEPING THE SYSTEM A BIT FURTHER SOUTH THAN PREVIOUSLY THOUGHT WITH LOW SLOWLY SHIFTING THROUGH THE NIGHT TOWARDS CTRL NEBRASKA. PLENTY OF MOISTURE WILL CONTINUE TO WRAP INTO THE SYSTEM KEEPING PRECIPITATION GOING THROUGH THE NIGHT. KEY FORECAST CHALLENGE IS PRECIP TYPES. APPEARS CHANGEOVER TO SNOW HAS OCCURRED OVER THE BLKHLS FOLLOWING A COOLER SOLUTION GIVEN THE SOUTHERN TREND OF THE MODELS. WITH SNOW EXPECTED TO CONTINUE GIVEN LARGE SCALE FORCING ALONG WITH UPSLOPE ENHANCEMENT HAVE UPGRADED TO WINTER STORM WARNING. TOWARDS THE ERN CWA MODELS CONTINUE TO INDICATE MODEST INSTABILITY SO WILL KEEP THUNDERSTORM CHANCES GOING INTO EVENING. THE TRICKY PART IS THE REMAINDER OF THE CWA WHERE TEMPERATURES ARE EXPECTED TO BE RIGHT NEAR THE RAIN/SNOW TRANSITION. HAVE KEEP SNOW ACCUMULATIONS TONIGHT OVER THE PLAINS ON THE LIGHTER SIDE BUT WILL RE-EVALUATE THIS THRU THE AFTERNOON/EVE BECAUSE IF ENOUGH COLD AIR PULLS IN RESULTING IN AN EARLY TRANSITION MORE SNOW WILL NEED TO BE ADDED. ON MONDAY...LOW SLOWLY LOITERS ITS WAY TOWARDS ERN NEBRASKA WITH PRECIPITATION CONTINUING TO AFFECT THE AREA. NEW CONCERN ADDED TO THE EQUATION WILL BE WINDS WITH PRESSURE GRADIENT TIGHTENING OVER THE AREA. GUSTY WINDS WILL BE ON THE INCREASE IN THE MORNING...WITH THE STRONGEST WINDS OVER THE ERN SIDE OF THE BLACK HILLS. PRECIP TYPES REMAIN TRICKY GIVEN THE TEMPS REMAINING NEAR THE TRANSITION...BUT CURRENTLY LOOKS AS IF MOST AREAS SHOULD BE RAIN IN THE AFTERNOON. MONDAY NIGHT...LOW WORKS ITS WAY TOWARDS THE IOWA/MISSOURI BORDER OVERNIGHT. EXPECT COOLER AIR TO WORK INTO THE SYSTEM BRINGING A PROBABLE TRANSITION TOWARDS SNOW TO MOST AREAS...THOUGH PRECIP RATES SHOULD BE LOWER...PARTICULARLY OVER THE FAR WRN CWA WITH THE SYSTEM SLOWLY PUSHING EAST. && .LONG TERM...TUESDAY THROUGH SUNDAY ISSUED AT 219 PM MDT SUN APR 27 2014 CLOSED UPPER LOW WILL SLOWLY MEANDER EAST IN THE PERIOD...SUPPORTING SEMI-BLOCKED FLOW. HEAVY NON-PROGRESSIVE TENDENCIES FAVORED IN THE PERIOD WITH COOL BELOW NORMAL TEMPS EXPECTED. LINGERING WANING DEFORMATION ZONE WILL BE PRESENT OVER THE FA AT THE START OF THE PERIOD...SUPPORTING SNOW ACCUMULATIONS AT SOME LOCATIONS. ALTHOUGH THIS SYSTEM WILL SHIFT EAST SLOWLY THE REMAINDER OF THE PERIOD...CYCLONIC FLOW WITH STEEP LAPSE RATES WILL LINGER THROUGH MUCH OF THE PERIOD BEFORE THE WESTERN NOAM RIDGE BEGINS TO EDGE EAST. HOWEVER...GIVEN THE HIGH AMPLITUDE NATURE OF THE UPPER RIDGE...WITH HIGH LATITUDINAL EXTENT...LONG TRAJECTORY NORTHERLY FLOW WILL SET THE STAGE FOR ANOTHER INTRUSION OF CP TOWARD THE END OF THE PERIOD. THIS HAS FAVORED A DOWNWARD TREND IN TEMPS IN THE SUNDAY PERIOD. GIVEN H85 TEMPS IN THE -2 TO 0C RANGE WITH A PASSING DISTURBANCE...SNOW ACCUMS MAY BE A POSSIBILITY ONCE AGAIN...ESP IN THE HIGHER TERRAIN. TUE-THU...LINGERING DEFORMATION ZONE WILL SUPPORT CHANCES FOR LIGHT RAIN/SNOW...ESP IN THE TUE PERIOD...WITH A HEAVY WANE IN ACTIVITY TOWARD WED GIVEN EAST PROPAGATION OF THE UPPER LOW WITH DRY AIR ADV INTO THE FA FORM THE NORTH. HOWEVER...LINGERING CYCLONIC FLOW WITH STEEP LL LAPSE RATES AND AVAILABLE LL MOISTURE WILL BE SUFFICIENT FOR A FEW SHOWERS INTO THUR. ADJUSTED TEMPS DOWN SOME...ESP TUE GIVEN PRECIP WITH AMPLE CLOUD CLOVER AND COOL THERMAL FIELDS. MODERATE SNOW ACCUMS ARE EXPECTED INTO TUE MORNING OVER THE NORTHERN BLACK HILLS...WITH SOME LIGHT ACCUMS ON THE SD PLAINS...UP TO AN INCH OR SO. THU-SUN...SLIGHT WARMING TREND THROUGH FRIDAY WITH LINGERING LOW CHANCES FOR SHOWERS THU. RIDGE FRONT DISTURBANCE LOOKS TO SHIFT SE INTO THE REGION FRI...POSSIBLY SUPPORTING A FEW SHOWERS WITH PEAK HEATING. OTHERWISE...A POTENTIALLY STRONGER SYSTEM LOOKS TO AFFECT THE REGION INTO THE WEEKEND...BRING MORE COOLER WEATHER BY SUNDAY AND THE CHANCE FOR RAIN AND/OR SNOW ONCE AGAIN. GIVEN AVAILABILITY OF COLD AIR PER HIGH LATITUDE RIDGING...THE POTENTIAL WILL EXIST FOR SOME SNOW ACCUMS. && .AVIATION...FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT ISSUED AT 1119 PM MDT SUN APR 27 2014 RAIN AND SNOW SHOWERS WILL CONTINUE THROUGH THE PERIOD WITH WIDESPREAD IFR CONDITIONS OVER THE BLACK HILLS AND SD PLAINS. DOWNSLOPING SHOULD CONFINE CIGS TO MVFR AT KRAP THROUGH MOST OF THE PERIOD. GUSTY NORTHWESTERLY WINDS WILL CONTINUE TO INCREASE OVERNIGHT WITH SURFACE WINDS OF 50KT POSSIBLE AROUND KRAP BY MONDAY MORNING. A DRY SLOT WILL BRING VFR CONDITIONS TO PORTIONS OF NE WYOMING AND SOUTH CENTRAL SOUTH DAKOTA THROUGH 12Z. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR SDZ024-028. WINTER WEATHER ADVISORY UNTIL 6 AM MDT MONDAY FOR SDZ042-044. WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ MONDAY TO 6 PM MDT /7 PM CDT/ TUESDAY FOR SDZ013-014-027-032-041>044-046-047-049. WINTER WEATHER ADVISORY UNTIL NOON MDT MONDAY FOR SDZ001-002-012- 025. WIND ADVISORY FROM NOON MONDAY TO 6 PM MDT TUESDAY FOR SDZ001- 002-012-025. HIGH WIND WARNING UNTIL 6 PM MDT TUESDAY FOR SDZ026-030-031- 072>074. WY...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR WYZ057. && $$ UPDATE...MLS SHORT TERM...77 LONG TERM...JC AVIATION...MLS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1122 PM MDT SUN APR 27 2014 .UPDATE... ISSUED AT 939 PM MDT SUN APR 27 2014 DECIDED TO START HIGH WIND WARNING SINCE THE AREA IN THE WATCH WAS ALREADY IN WARNING CRITERIA...KRAP GUST TO 52KT AT 0202Z. LOOKING AT LATEST HI RES MODEL GUIDANCE...HRRR AND RAP...LOOKS LIKE 30 TO 40 MPH WINDS WILL CONTINUE THRU THE NIGHT BEFORE REALLY PICKING UP BY 13Z MONDAY. SEEING VERY STRONG DOWNSLOPE WINDS FROM THE BLACK HILLS IN THE HIGH WIND WARNING AREA. COULD SEE SOME LIGHTER WINDS OVERNIGHT...HOWEVER SINCE WE WERE ALREADY HAVING HIGH WINDS AND CONFIDENCE IN HIGH WINDS FOR MONDAY AND TUESDAY WERE HIGH...DECIDED TO GO WITH THE WARNING. UPDATE ISSUED AT 822 PM MDT SUN APR 27 2014 DECIDED TO PUT OUT A WINTER WEATHER ADVISORY FOR SNOW FOR SHANNON AND BENNETT COUNTIES. MADE A FEW CALLS AND LOOKING AT WEBCAMS MARTIN ALREADY HAD AN INCH AND PINE RIDGE HAD A COUPLE INCHES. LATEST RAP MODEL AND HRRR BOTH INDICATE A TROWAL SETTING UP OVER THIS AREA TONIGHT. EXPECT A BAND OF HEAVY SNOW WITH AMOUNTS OF 2 TO 5 INCHES FOR THIS AREA. ONLY HAVE THE ADVISORY TIL 12Z...BUT SNOW MAY CONTINUE A BIT LONGER. ONCE THE SNOW STOPS THE WINDS WILL START IN THIS AREA SO KEPT WIND ADVISORY BEGINNING AT 12Z. NEXT SHIFT MAY HAVE TO ADJUST THE TIMING DEPENDING ON THE SNOWFALL. UPDATE ISSUED AT 640 PM MDT SUN APR 27 2014 LATEST HRRR MODEL AND SURFACE ANALYSIS SHOWS A LEE MESO-LOW OVER CENTRAL CUSTER COUNTY. THE ISOBARS SHOW A TIGHT GRADIENT OVER WESTERN FALL RIVER COUNTY AND ALONG THE EASTERN FOOTHILLS FROM RAPID CITY TO HERMOSA AND ABOUT 60 MILES EAST ONTO THE PLAINS. THIS FEATURE IS PROGGED TO CONTINUE THROUGH 02Z-03Z THIS EVENING. THE RESULT WILL BE A BRIEF PERIOD OF GUSTY NORTHWEST WINDS OF 35 TO 40 MPH AND GUSTS UP TO 55 MPH. SINCE THIS FEATURE IS VERY LOCALIZED AND WILL BE SHORT LIVED WITH WINDS DIMINISHING AFTER 03Z BEFORE INCREASING AGAIN EARLY MONDAY MORNING...THOUGHT IT WOULD BE BEST COVERED WITH A SPECIAL WEATHER STATEMENT INSTEAD OF GOING WITH A WIND ADVISORY OR HIGH WIND WARNING. OTHERWISE THE FORECAST IS ON TRACK...AM WATCHING THE NORTHERN HILLS CLOSELY SINCE SOME AREAS HAVE ALREADY PICKED UP A FEW INCHES OF SNOW. HOWEVER WINTER STORM WARNING AT THE HIGHER ELEVATIONS AND WINTER WEATHER ADVISORY AROUND SPEARFISH LOOK TO BE GOOD AT THIS TIME. && .SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT ISSUED AT 219 PM MDT SUN APR 27 2014 CURRENT SURFACE ANALYSIS PLACES LOW OVER NWRN KANSAS/SWRN NEBRASKA...WHILE UPPER LEVEL ANALYSIS INDICATES LOW HAS BECOME STACKED. TWO MAIN AREAS OF PRECIP HAVE DEVELOPED OVER THE CWA WITH THE FIRST ONE ORIENTATED N/S ALONG THE WRN SD BORDER ALONG AREA OF STRONG MID-LEVEL FRONTOGENESIS WHILE SECONDARY AREA OF PRIMARILY THUNDERSTORMS CONTINUES TO PUSH W/NWRLY NEAR NOSE OF JET STREAK. FOR THE REST OF THIS AFTERNOON INTO TONIGHT...A POTPOURRI OF WEATHER TYPES ARE EXPECTED AS STRONG LOW PRESSURE SYSTEM CREEPS ITS WAY THROUGH THE REGION. LATEST GUIDANCE KEEPING THE SYSTEM A BIT FURTHER SOUTH THAN PREVIOUSLY THOUGHT WITH LOW SLOWLY SHIFTING THROUGH THE NIGHT TOWARDS CTRL NEBRASKA. PLENTY OF MOISTURE WILL CONTINUE TO WRAP INTO THE SYSTEM KEEPING PRECIPITATION GOING THROUGH THE NIGHT. KEY FORECAST CHALLENGE IS PRECIP TYPES. APPEARS CHANGEOVER TO SNOW HAS OCCURRED OVER THE BLKHLS FOLLOWING A COOLER SOLUTION GIVEN THE SOUTHERN TREND OF THE MODELS. WITH SNOW EXPECTED TO CONTINUE GIVEN LARGE SCALE FORCING ALONG WITH UPSLOPE ENHANCEMENT HAVE UPGRADED TO WINTER STORM WARNING. TOWARDS THE ERN CWA MODELS CONTINUE TO INDICATE MODEST INSTABILITY SO WILL KEEP THUNDERSTORM CHANCES GOING INTO EVENING. THE TRICKY PART IS THE REMAINDER OF THE CWA WHERE TEMPERATURES ARE EXPECTED TO BE RIGHT NEAR THE RAIN/SNOW TRANSITION. HAVE KEEP SNOW ACCUMULATIONS TONIGHT OVER THE PLAINS ON THE LIGHTER SIDE BUT WILL RE-EVALUATE THIS THRU THE AFTERNOON/EVE BECAUSE IF ENOUGH COLD AIR PULLS IN RESULTING IN AN EARLY TRANSITION MORE SNOW WILL NEED TO BE ADDED. ON MONDAY...LOW SLOWLY LOITERS ITS WAY TOWARDS ERN NEBRASKA WITH PRECIPITATION CONTINUING TO AFFECT THE AREA. NEW CONCERN ADDED TO THE EQUATION WILL BE WINDS WITH PRESSURE GRADIENT TIGHTENING OVER THE AREA. GUSTY WINDS WILL BE ON THE INCREASE IN THE MORNING...WITH THE STRONGEST WINDS OVER THE ERN SIDE OF THE BLACK HILLS. PRECIP TYPES REMAIN TRICKY GIVEN THE TEMPS REMAINING NEAR THE TRANSITION...BUT CURRENTLY LOOKS AS IF MOST AREAS SHOULD BE RAIN IN THE AFTERNOON. MONDAY NIGHT...LOW WORKS ITS WAY TOWARDS THE IOWA/MISSOURI BORDER OVERNIGHT. EXPECT COOLER AIR TO WORK INTO THE SYSTEM BRINGING A PROBABLE TRANSITION TOWARDS SNOW TO MOST AREAS...THOUGH PRECIP RATES SHOULD BE LOWER...PARTICULARLY OVER THE FAR WRN CWA WITH THE SYSTEM SLOWLY PUSHING EAST. && .LONG TERM...TUESDAY THROUGH SUNDAY ISSUED AT 219 PM MDT SUN APR 27 2014 CLOSED UPPER LOW WILL SLOWLY MEANDER EAST IN THE PERIOD...SUPPORTING SEMI-BLOCKED FLOW. HEAVY NON-PROGRESSIVE TENDENCIES FAVORED IN THE PERIOD WITH COOL BELOW NORMAL TEMPS EXPECTED. LINGERING WANING DEFORMATION ZONE WILL BE PRESENT OVER THE FA AT THE START OF THE PERIOD...SUPPORTING SNOW ACCUMULATIONS AT SOME LOCATIONS. ALTHOUGH THIS SYSTEM WILL SHIFT EAST SLOWLY THE REMAINDER OF THE PERIOD...CYCLONIC FLOW WITH STEEP LAPSE RATES WILL LINGER THROUGH MUCH OF THE PERIOD BEFORE THE WESTERN NOAM RIDGE BEGINS TO EDGE EAST. HOWEVER...GIVEN THE HIGH AMPLITUDE NATURE OF THE UPPER RIDGE...WITH HIGH LATITUDINAL EXTENT...LONG TRAJECTORY NORTHERLY FLOW WILL SET THE STAGE FOR ANOTHER INTRUSION OF CP TOWARD THE END OF THE PERIOD. THIS HAS FAVORED A DOWNWARD TREND IN TEMPS IN THE SUNDAY PERIOD. GIVEN H85 TEMPS IN THE -2 TO 0C RANGE WITH A PASSING DISTURBANCE...SNOW ACCUMS MAY BE A POSSIBILITY ONCE AGAIN...ESP IN THE HIGHER TERRAIN. TUE-THU...LINGERING DEFORMATION ZONE WILL SUPPORT CHANCES FOR LIGHT RAIN/SNOW...ESP IN THE TUE PERIOD...WITH A HEAVY WANE IN ACTIVITY TOWARD WED GIVEN EAST PROPAGATION OF THE UPPER LOW WITH DRY AIR ADV INTO THE FA FORM THE NORTH. HOWEVER...LINGERING CYCLONIC FLOW WITH STEEP LL LAPSE RATES AND AVAILABLE LL MOISTURE WILL BE SUFFICIENT FOR A FEW SHOWERS INTO THUR. ADJUSTED TEMPS DOWN SOME...ESP TUE GIVEN PRECIP WITH AMPLE CLOUD CLOVER AND COOL THERMAL FIELDS. MODERATE SNOW ACCUMS ARE EXPECTED INTO TUE MORNING OVER THE NORTHERN BLACK HILLS...WITH SOME LIGHT ACCUMS ON THE SD PLAINS...UP TO AN INCH OR SO. THU-SUN...SLIGHT WARMING TREND THROUGH FRIDAY WITH LINGERING LOW CHANCES FOR SHOWERS THU. RIDGE FRONT DISTURBANCE LOOKS TO SHIFT SE INTO THE REGION FRI...POSSIBLY SUPPORTING A FEW SHOWERS WITH PEAK HEATING. OTHERWISE...A POTENTIALLY STRONGER SYSTEM LOOKS TO AFFECT THE REGION INTO THE WEEKEND...BRING MORE COOLER WEATHER BY SUNDAY AND THE CHANCE FOR RAIN AND/OR SNOW ONCE AGAIN. GIVEN AVAILABILITY OF COLD AIR PER HIGH LATITUDE RIDGING...THE POTENTIAL WILL EXIST FOR SOME SNOW ACCUMS. && .AVIATION...FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT ISSUED AT 1119 PM MDT SUN APR 27 2014 RAIN AND SNOW SHOWERS WILL CONTINUE THROUGH THE PERIOD WITH WIDESPREAD IFR CONDITIONS OVER THE BLACK HILLS AND SD PLAINS. DOWNSLOPING SHOULD CONFINE CIGS TO MVFR AT KRAP THROUGH MOST OF THE PERIOD. GUSTY NORTHWESTERLY WINDS WILL CONTINUE TO INCREASE OVERNIGHT WITH SURFACE WINDS OF 50KT POSSIBLE AROUND KRAP BY MONDAY MORNING. A DRY SLOT WILL BRING VFR CONDITIONS TO PORTIONS OF NE WYOMING AND SOUTH CENTRAL SOUTH DAKOTA THROUGH 12Z. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR SDZ024-028. WINTER WEATHER ADVISORY UNTIL 6 AM MDT MONDAY FOR SDZ042-044. WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ MONDAY TO 6 PM MDT /7 PM CDT/ TUESDAY FOR SDZ001-002-012>014-025-027-032-041>044-046- 047-049. HIGH WIND WARNING UNTIL 6 PM MDT TUESDAY FOR SDZ026-030-031- 072>074. WINTER WEATHER ADVISORY UNTIL NOON MDT MONDAY FOR SDZ025. WY...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR WYZ057. && $$ UPDATE...MLS SHORT TERM...77 LONG TERM...JC AVIATION...MLS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1245 AM CDT MON APR 28 2014 .UPDATE...FOR 06Z TAFS. && .AVIATION... SIGNIFICANT SYSTEM TO CROSS THE MID-SOUTH THE NEXT 18-24 HOURS. SHWRS/STMS EXPECTED TO AFFECT ALL SITES OFF AND ON THROUGH THE PERIOD...WHICH WILL BRING VARYING CONDITIONS. BEST CHANCE FOR STRONGEST STORMS LOOKS TO BE THE 18-03Z RANGE MON-TUE. STORMS WILL CONTAIN VERY HEAVY RAIN WHICH WILL GREATLY REDUCES VSBYS AND POSSIBLY CIGS. STRONG STMS LIKELY TO CONTAIN 30-40+KT WIND GUSTS AS WELL. && .PREV DISCUSSION... /ISSUED 1009 PM CDT SUN APR 27 2014/ UPDATE... SHOWER AND ISOLATED TSTM ACTIVITY NOW CONFINED TO GENERALLY THE NORTHEASTERN HALF OF THE MID STATE. LATEST HRRR SHOWS REDEVELOPMENT OVER OUR NORTHWESTERN COUNTIES AROUND 3 OR 4 AM IN THE MORNING. THE ACTIVITY AT THAT TIME STILL DOES NOT LOOK SEVERE. ELSEWHERE...JUST SCT ACTIVITY IS POSSIBLE. MODELS ARE IN AGREEMENT WITH A BUILDUP OF SUBSIDENCE TOWARD 12Z OVER WESTERN TN. SO...ONSET OF SEVERE MAY HOLD OFF UNTIL AFTER THE 12Z-15Z WINDOW. FOR THIS NEXT UPDATE...WILL BE LOWERING POPS FOR THE REMAINDER OF THE OVERNIGHT. BUT...WILL AT LEAST MAINTAIN LIKELY POPS FOR MUCH OF THE NORTHWEST. ELSEWHERE...WILL GENERALLY KEEP POPS IN THE CHC CATEGORY. OTW...LOW TEMPS LOOK FINE AS DEWPOINTS WILL REMAIN NEARLY STEADY. FOR THE REMAINDER OF THE OVERNIGHT...IT DOES NOT LOOK AS THOUGH ANY SEVERE WEATHER WILL HIT US. BUT...THAT WILL CHANGE AFTER 12Z-15Z. PREV DISCUSSION... /ISSUED 805 PM CDT SUN APR 27 2014/ DISCUSSION... CURRENT RADAR IMAGERY SHOWING A LARGE AMOUNT OF REFLECTIVITY COVERAGE IN THE FORM OF SHOWERS AND NON SEVERE TSTMS. MODELS SHOW THAT AN INCREASE IN MOISTURE DEPTH IS EXPECTED THIS EVENING AND OVERNIGHT. WILL GO AHEAD AND UP POPS AREA WIDE. OTW...IN TERMS OF THE SEVERE POTENTIAL ANALYSIS...LATEST SOUNDING FOR OHX IS IN NOW. CURRENT LI IS + 1.8 AND SUPPORTS THE RELATIVELY STABLE CONDITIONS ACROSS MIDDLE TN AT THIS TIME. THE FURTHER WEST YOU GO HOWEVER...INSTABILITIES DO INCREASE. THE CLOSEST SEVERE WARNINGS ARE ACROSS NW MS AND THE BOOTHEEL OF MO. THE ACTIVITY LOOKS ESPECIALLY NASTY IN THE CENTRAL AR AREA. MODELS IN AGREEMENT AND SUPPORT INCREASINGLY UNSTABLE AIR THE FURTHER WEST YOU GO. THROUGH 12Z...WE REALLY SEE NO INCREASE IN INSTABILITY LEVELS OVER MIDDLE AND EASTERN AREAS OF THE MID STATE. HOWEVER...OVER THE WESTERN QUARTER OR SO OF MIDDLE TN...WE DO SEE A SUBSTANTIAL DECREASE IN SHOWALTER VALUES. THE MID AND LOW LEVEL JET DYNAMICS WILL BE ON THE INCREASE OVER WESTERN TN OVERNIGHT AS WELL. ALL IN ALL...LOOKS LIKE NON SEVERE TSTMS OVERNIGHT EXCEPT AS WE APPROACH 12Z...THE RISK OF SEVERE WILL BEGIN TO INCREASE OVER OUR FAR WESTERN AREAS. AGAIN...WILL UP THE POPS FOR ALL AREAS FOR TONIGHT. UPDATES WILL BE SENT SHORTLY. PREV DISCUSSION... /ISSUED 717 PM CDT SUN APR 27 2014/ UPDATE...FOR 00Z TAFS. AVIATION... SIGNIFICANT SYSTEM TO CROSS THE MID-SOUTH THE NEXT 24 HOURS. SHWRS/STMS EXPECTED TO AFFECT ALL SITES OFF AND ON THROUGH THE PERIOD...WHICH WILL BRING A MULTITUDE OF VARYING CONDITIONS. BEST CHANCE FOR STRONGEST STORMS LOOKS TO BE THE 15-00Z RANGE MONDAY. STORMS WILL CONTAIN VERY HEAVY RAIN WHICH WILL GREATLY REDUCES VSBYS AND POSSIBLY CIGS. STRONG STMS LIKELY TO CONTAIN 40+KT WIND GUSTS AS WELL. PREV DISCUSSION... /ISSUED 355 PM CDT SUN APR 27 2014/ AS OF 3 PM...ISOLATED SHOWERS AND STORM DEVELOPMENT CONTINUED NORTH OF THE WARM FRONT AND ITS ASSOCIATED CONVECTION. THE FRONT HAS BEEN VERY SLUGGISH TO PROGRESS NORTHWARD...AND AS A RESULT...HAS RESULTED IN SOME FLASH FLOODING CONCERNS IN NORTHERN MS. THIS ACTIVITY SHOULD CONTINUE TO INCH NORTH THROUGH THE LATE AFTERNOON AND EVENING. STILL THINK THAT HEAVY RAINS...FREQUENT CG STRIKES...AND SOME SMALL HAIL/GUSTY WINDS WILL BE THE THREATS UNTIL NIGHTFALL...THEN ACTIVITY SHOULD MELLOW AS IT EXITS NORTH OF THE STATE LINE. REGARDING THE FORECAST SEVERE LINE OF STORMS THAT HAS BEEN ADVERTISED FOR THE LAST FEW DAYS...HRRR/RAP/WRF HI RES MODELS CONTINUE TO INDICATE A SEVERE LINE OF STORMS THAT SHOULD REACH THE TN RIVER WELL AFTER MIDNIGHT. ALL THE DETERMINISTIC MODELS BLOW THIS SQUALL LINE THROUGH THE MID STATE BY LATE MORNING MONDAY. FOR THE PERIOD 18Z MONDAY THROUGH 06Z TUESDAY... THIS CONTINUES TO BE THE TIMEFRAME IN WHICH THE HIGHEST POTENTIAL FOR SEVERE WEATHER APPEARS TO BE. THE POTENTIAL FOR A WIDESPREAD SEVERE WEATHER OUTBREAK INCLUDING VERY LARGE HAIL AND STRONG...POTENTIALLY NUMEROUS...TORNADOES CONTINUES TO EXIST. AFTER CLOSE EXAMINATION OF THE DETERMINISTIC MODELS...THE ONLY NOTABLE DIFFERENCE FROM PREVIOUS FORECASTS APPEARS TO BE A SOMEWHAT EARLIER POSSIBLE CONVECTIVE INITIATION TIMING ESTIMATE. 12Z-15Z FORECAST SOUNDINGS INDICATE VERY RAPID WARMING AND RAPIDLY INCREASING INSTABILITY PARAMETERS FOR THE WESTERN HALF OF THE MID STATE. SIMULTANEOUSLY...THE RIGHT EXIT REGION OF A 250 MB JET STREAK WILL BE DEVELOPING OVER THE MS RIVER AND SHOULD BE AROUND THE TN RIVER BY 18Z. OMEGA FIELDS ECHO THE IMPLIED DEEP LAYER LIFT DEVELOPING IN WESTERN TN IN THE MORNING AND A VERY STRONG DYNAMIC AND RAPIDLY DEVELOPING CONVECTIVE SET UP LOOKS TO BE IN STORE FOR THE WESTERN TN AND WESTERN MIDDLE TENNESSEE AREAS. THE BIGGEST QUESTION AROUND THIS TIME IS WHERE IN FACT CI WILL TAKE PLACE...AND INTERROGATING SUBTLETIES IN THE WIND FIELDS OF ALL THE PROGGED SFC WIND FIELDS...A SUBTLE SURFACE CONFLUENCE ZONE LOCATED JUST WEST OF THE TN RIVER MAY BE THE LOCATION THAT THIS CI TAKES PLACE. CONFIDENCE IS QUITE LOW IN THAT REGARD HOWEVER. AFTER CI TAKES PLACE...THESE CELLS SHOULD BEGIN TAKING SUPERCELL STRUCTURE AND STEERING FLOW SHOULD BE EAST NORTHEASTERLY AT ABOUT 40-50 KTS. THIS WOULD PUT ALL OF MIDDLE TENNESSEE IN THE PATH OF VERY STRONG SUPERCELLS SHOULD THIS OUTCOME COME TO FRUITION. IF EVERYTHING GOES AS INDICATED IN THE MODELS...THE 21Z TO 03Z TIMEFRAME LOOKS TO BE THE TIMEFRAME OF PEAK THREAT. OVERALL FORECAST LIMITING FACTORS...SOME OF THE VARIABLES THAT CONTINUE TO COMPLICATE THE FORECAST. THERE IS LOWER CONFIDENCE IN THE HI RES MODELS OF LATE DUE TO ITS INABILITY TO ACCURATELY HANDLE THE CONVECTION FROM TODAY. THIS MAKES THE SQUALL LINE POTENTIAL FOR TONIGHT MORE QUESTIONABLE HOWEVER THERE ARE STILL A FEW MORE HOURS OF POTENTIAL DEVELOPMENT OUT WEST. ADDITIONALLY...THE LARGE AMOUNTS OF RAINFALL THAT HAS BEEN OBSERVED IN NORTHERN MS AND WESTERN TN MAY KEEP THE LOW LEVEL ATMOSPHERE QUITE MOIST TOMORROW AND THUS KEEP LOW LEVEL CLOUD COVER IN THE AREA IF THE PREVIOUSLY FORECAST SQUALL LINE DOES NOT COME TO FRUITION AND CLEAR EVERYTHING OUT. THIS WOULD RESULT IN INHIBITED INSTABILITY AND DELAY STORM DEVELOPMENT INTO THE LATER AFTERNOON. WITH THE MULTITUDE OF VARIABLES UNKNOWN DUE TO ONGOING CONVECTION...THESE LIMITING FACTORS ARE DIFFICULT TO ASSESS. ADDITIONALLY...PWAT VALUES SHOULD STAY WELL ABOVE NORMAL THROUGHOUT THE NEXT 48 HOURS. SO IN ADDITION TO THE SEVERE WEATHER POTENTIAL...HEAVY RAIN POTENTIAL AND POSSIBLE FLASH FLOODING WILL BE A SIGNIFICANT THREAT. HPC IS INDICATING AROUND 5 INCHES OF RAIN FROM 00Z TONIGHT THROUGH 00Z WEDNESDAY. NOTE HOWEVER THAT A LARGE PORTION OF THIS RESTS ON WHETHER TONIGHTS STORM SYSTEM DEVELOPS AS FORECAST IN THE SHORT RANGE MODELS. BEYOND 06Z TUESDAY...LEFT FORECAST BASICALLY UNCHANGED WITH ANOTHER POTENTIAL ROUND OF STRONG TO SEVERE WEATHER POSSIBLE TUESDAY AFTERNOON AND EVENING. PREFER NOT TO ADD ANY MORE DETAILS TO THIS FORECAST WITHOUT SEEING HOW TOMORROW UNFOLDS FIRST AS IT WILL DIRECTLY IMPACT WHAT HAPPENS TUESDAY. BUT FOR WHAT ITS WORTH...SPC HAS DOWNGRADED TUESDAYS THREAT FOR MIDDLE TENNESSEE TO ONLY GENERAL THUNDERSTORMS. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
421 AM CDT MON APR 28 2014 .DISCUSSION... BKN LINE OF TSTMS HAS DEVELOPED SEVERAL MILES AHEAD OF THE SFC TROF EXTENDING FROM NORTHEAST TEXAS AND INTO NORTHERN PARTS OF SE TX. NO REPORTS OF SEVERE WX IN OUR CWA JUST YET BUT WOULD BE SURPRISED IF NO HAIL IS EVENTUALLY REPORTED FROM HOUSTON COUNTY W/ THOSE STORMS. THINK MAJORITY OF THESE WILL REMAIN ELEVATED SO HAIL WILL BE PRIMARY THREAT. HRRR MODEL HAS BEEN DOING A GOOD JOB IN THE PAST 24 HOURS AND HAS CONTINUED DOING WELL WITH CURRENT TRENDS. IT SHOWS THIS PRECIPITATION MAKING ITS WAY SEWD TOWARD THE UPPER TX COAST IN THE NEXT 6 HOURS SO HAVE BUMPED POPS UP ACROSS A GOOD PART OF THE AREA. SFC TROF WILL MAKE IT ALMOST TO THE COAST BY LATE MORNING ENDING PRECIP CHANCES AND BRINGING A DRY AIRMASS INTO MOST OF THE AREA. THIS DRY AIRMASS AND SUNSHINE SHOULD ALLOW FOR A RAPID WARM UP ACROSS THE AREA THIS AFTN. SFC TROF MOVES BACK NORTH LATE TONIGHT AND BECOME OVERTAKEN BY THE PRIMARY COLD FRONT THAT WILL PUSH ACROSS THE AREA DURING THE DAY TUE. CURRENT GUIDANCE COMING IN A TOUCH COOLER THAN EARLIER FCSTS SO NUDGED HIGHS/LOWS DOWN A BIT FOR THE NEXT SEVERAL DAYS. THRU LATE WEEK WE SHOULD STILL BE IN A WSW FLOW ALOFT UNDER BROAD UPPER TROF SITUATED ACROSS CNTL PARTS OF THE COUNTRY. MAY SEE PERIODS OF HIGH CLOUDINESS BUT MEAGER LLVL MOISTURE LEVELS SHOULD KEEP THINGS MOSTLY DRY. SHOULD TRANSITION TO A DRY NW FLOW LATE IN THE WEEK AND EARLY WEEKEND AS UPPER TROF MOVES EWD. OTHERWISE...LOOKS QUITE DRY THRU THE 1ST WEEK OF MAY. 47 && .MARINE... WILL EXTEND THE CURRENT ADVISORIES OVER THE COASTAL WATERS/CAUTION FLAGS ON THE BAYS INTO THE MID MORNING HRS BASED ON CURRENT TRENDS. GRADIENT STILL EXPECTED TO WEAKEN BY THE AFTN WITH THE APPROACH OF THE PACIFIC FRONT FROM THE WEST. AS THIS BOUNDARY STALLS ALONG THE COASTLINE...WINDS SHOULD REMAIN OUT OF THE SW/S THROUGH THE DAY/TO- NIGHT. THE MAIN PUSH OF STRONG NORTH WINDS STILL FCST FOR TUE AFTN WITH THE CANADIAN COLD FRONT. BEHIND THIS FRONT...CAUTION/ADVISORY FLAGS WILL BE LIKELY FROM TUE NIGHT INTO WEDS NIGHT. THIS OFFSHORE FLOW COULD EXTEND THROUGH THE END OF THE WEEK. 41 && .AVIATION... HAVING TO KEEP AN EYE ON DEVELOPMENT OUT TO OUR W/NW THRU THE MORN- ING HOURS. PROBABLY CANNOT AVOID THE MENTION OF THUNDER IN THE NRN HALF TAF SITES (CLL/UTS/CXO/IAH) THIS MORNING UNTIL THIS AFTN. THE APPROACH/PASSAGE OF THE PACIFIC FRONT (IN WHICH THIS PCPN IS FOCUS- ING ON) SHOULD BRING DRIER AIR AND VFR CONDITIONS TO THE AREA LATE THIS AFTN/TONIGHT. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 90 59 82 51 75 / 20 10 10 0 0 HOUSTON (IAH) 91 62 86 55 78 / 50 10 10 0 0 GALVESTON (GLS) 84 71 84 62 77 / 50 10 20 0 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 7 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. SMALL CRAFT ADVISORY UNTIL 7 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
326 AM CDT MON APR 28 2014 .SHORT TERM (TODAY THROUGH TUESDAY)...WARM AND DRY TODAY AND TUESDAY TOO (MOST AREAS)...AS COLD AIR IS EXPECTED TO LAG BEHIND THE FRONTAL BOUNDARY ON TUESDAY. LOOKS LIKE ANOTHER HOT DAY...BUT NOT AS HOT AS YESTERDAY AT LEAST OUT TO THE WEST AS BOUNDARY LAYER TEMPERATURES ARE PROGGED TO BE SEVERAL DEGREES COOLER (SO IF THAT HAPPENS IT SHOULD BE COOLER). 4KM RUC IS SHOWING TEMPERATURES TOPPING 100 DEGREE BARRIER OVER THE SOUTHERN AREAS...AND WILL GO 101/102 OVER THE SOUTHWESTERN AREAS. OTHERWISE...MORNING LOW CLOUDS OVER THE EAST WILL QUICKLY LIFT AND SHOULD SEE LOTS OF SUN WITH NORTHWEST WINDS AS DRY LINE MOVES FARTHER EAST THAN YESTERDAY. LOW LEVEL MOISTURE IS TOO SCOURED OUT FOR ANY MENTION OF RAIN (EVEN OFFSHORE) SO HAVE REMOVED (4KM MODELS KEEP THINGS DRY TOO). FOR TONIGHT...ONLY NAM IS BRINGING COOLER AIR MUCH FASTER THAN GFS/ECMWF (ALTHOUGH CANADIAN IS COOL TOO...AS USUAL). AM GOING TO PREFER TO GO MORE ON THE WARM SIDE TONIGHT ALTHOUGH IF WINDS ARE TOO LIGHT AND SURFACE MOISTURE IS TOO LOW...WE COULD REALLY BOTTOM OUT (GIVEN WARM DAY EXPECTED TODAY WILL PREFER TO STAY ON THE WARM SIDE THOUGH). COOLER AGAIN ON TUESDAY BUT STILL WARMER THAN NORMAL WITH COLD AIR LAGGING ON FRONT. MAY SEE A FEW 80S IN THE VICTORIA AREA. MOISTURE AGAIN TOO LIMITED FOR PRECIPITATION. && .MARINE (TODAY THROUGH TUESDAY)...HAVE EXTENDED THE SCA TIL 4 AM FOR THE BAYS/WATERWAYS...AND LONGER FOR THE GULF WATERS. MAY NEED TO EXTEND AGAIN AT THE LAST MINUTE IF WINDS STAY UP AGAIN. WINDS HAVE STAYED UP LONGER THAN EXPECTED WITH GUSTS OVER 30 KNOTS AT KNGP. 4KM RUC HAS WINDS CRANKING TIL 12Z OR SO...BUT THIS IS NORMALLY ON THE HIGH SIDE (BUT STILL DOING BETTER THAN NAM12 OR OTHER MODELS). WINDS DO DECREASE BY SUNRISE...BUT SEAS STAY UP. THUS...THE GULF WATER SCA WILL MAINLY BE FOR HIGH SEAS MONDAY...WITH SCA CONDITIONS ENDING AROUND NOON. VISIBILITIES OVER THE MARINE AREAS ARE BETWEEN 1 AND 3 MILES...AND THAT SHOULD CLEAR UP LATER THIS MORNING. MORE FOG TONIGHT BUT THAT SHOULD BE OVER THE OFFSHORE WATERS (IF THAT)...AS DRIER AIR DOES GET INTO THE NEARSHORE WATERS. COULD NOT RULE OUT A ROGUE SHOWER NEAR MATAGORDA ISLAND BUT THAT WILL BE VERY BRIEF AND UNLIKELY TO HAPPEN (SO NOT IN FORECAST). && .FIRE WEATHER (TODAY THROUGH TUESDAY)...FIRE WEATHER PROCEDURE IS SHOWING ELEVATED CONDITIONS/ISOLATED CRITICAL OVER MUCH OF THE AREA ON TUESDAY. FUEL DRYNESS FORECAST MAP IS SHOWING MOST AREAS IN NORMAL MOISTURE..WITH ONLY A PART OF THE NORTHERN COASTAL BEND (LIVE OAK AND PORTIONS OF BEE AND MCMULLEN COUNTIES) IN DRY FUELS. SINCE THESE COUNTIES ARE FORECAST TO BE IN ELEVATED CONDITIONS ON TUESDAY...NO NEED FOR FIRE WEATHER WATCH OR RED FLAG WARNING. DAY SHIFT OR NEXT MID SHIFT CAN RE-EVALUATE...ESPECIALLY IF FUEL DRYNESS MAP CHANGES THE NEXT DAY. && .LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...PERIOD BEGINS WITH COOLER TEMPERATURES AND DRY CONDITION IN WAKE OF TUESDAY/S/S FROPA. BROAD LONGWAVE TROUGH CENTERED OVER THE FAR NORTH CENTRAL STATES WILL KEEP FAIRLY ZONAL FLOW OVER SOUTH TEXAS THROUGH THURSDAY. TROUGH WILL FINALLY SWING OVER THE REGION THURSDAY NIGHT INTO FRIDAY. ECMWF CONTINUES TO BE THE WETTER SOLUTION WITH THIS PASSING WHILE THE GFS/NAM STAY MOSTLY DRY OVERLAND. WHILE THERE IS THE UPPER LEVEL SUPPORT FOR PERHAPS SOME SPRINKLES AND RAIN TO DEVELOP THERE IS AN OVERALL LACK OF SUFFICIENT MOISTURE OVER MOST OF THE REGION EXCEPT IN THE OVER THE OFFSHORE WATERS THURSDAY NIGHT INTO FRIDAY MORNING. KEPT THE 20 POPS MENTION OVER THE OFFSHORE WATERS FOR NOW...BUT EVEN THIS MAY BE GOING TOO HIGH. OTHERWISE EXPECT A CONTINUED DRY FORECAST. TEMPERATURES WILL BE NICELY COOLER (BELOW AVERAGE) THROUGH THE END OF THE WEEK BEFORE RETURNING TO NORMAL ON BY THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 99 66 93 61 80 / 10 0 10 10 10 VICTORIA 93 63 88 55 81 / 10 0 10 10 10 LAREDO 104 69 98 62 86 / 0 0 10 10 10 ALICE 102 64 96 57 83 / 10 0 10 10 10 ROCKPORT 92 67 89 62 79 / 10 0 10 10 10 COTULLA 98 63 92 54 83 / 0 0 0 10 10 KINGSVILLE 102 65 97 60 81 / 10 0 10 10 10 NAVY CORPUS 90 67 87 65 79 / 10 0 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 11 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 4 AM CDT EARLY THIS MORNING FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O`CONNOR. SMALL CRAFT ADVISORY UNTIL 7 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM. && $$ GW/86...SHORT TERM LK/84...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1226 AM CDT MON APR 28 2014 .DISCUSSION...SEE 06Z AVIATION DISCUSSION AND MARINE DISCUSSION...AS EXTENDED THE SCA FOR ANOTHER FEW HOURS. && .AVIATION...IFR CIGS WILL CONTINUE OR DEVELOP AT KCRP AND KVCT...AND MAY EVEN GET INTO KALI BEFORE SUNRISE. VSBYS SHOULD BE MVFR FOR THE MOST PART...BUT COULD SEE SOME TEMPO IFR AT KVCT AND KALI. SURFACE TROUGH APPROACHES THIS MORNING...BRINGING NORTHWEST WINDS AND SHOULD RAPIDLY LIFT IFR CONDITIONS BY 15Z. CONDITIONS SHOULD REMAIN VFR FOR THE REST OF THE PERIOD...EXCEPT MAYBE SOME LIGHT FOG AT KVCT ONCE THE WINDS DIE DOWN. GENERALLY N-NW WINDS BY 15Z DIMINISHING IN THE AFTERNOON...THEN LIGHT SOUTHERLY AFTER SUNSET AS SEA-BREEZE DIMINISHES. && .MARINE...WINDS NEAR THE COAST ARE STILL GOING PRETTY STRONG...WITH KNGP GUSTING TO OVER 30 KNOTS. BASED ON HRRR AND LOWER RESOLUTION MODEL DATA...HAVE EXTENDED THE SCA FOR THE BAYS AND FOR THE NEARSHORE WATERS ANOTHER 1-2 HOURS. WILL KEEP MENTION OF CONVECTION IN FOR NOW...BUT MAY PULL IT OUT IN THE MORNING PACKAGE IF DRIER MODEL TRENDS CONTINUE. UPDATED MWW AND CWF OUT. && .PREV DISCUSSION... /ISSUED 710 PM CDT SUN APR 27 2014/ DISCUSSION...UPDATED FOR 00Z AVIATION. AVIATION...DRYLINE HAS RETREATED THIS EVENING WITH E TO ESE WINDS RETURNING TO ALI/CRP. VFR CONDITIONS WILL PERSIST THROUGH AT LEAST 06Z...BUT MVFR/IFR CONDITIONS MAY DEVELOP AT ALI/VCT LATE TONIGHT WITH LOW CLOUDS AND FOG/BR...AND MVFR CONDITIONS AT CRP DUE TO BR. CONDITIONS WILL IMPROVE BY 14Z ON MONDAY WITH VFR CONDITIONS THROUGH THE REMAINDER OF THE DAY. PREV DISCUSSION... /ISSUED 413 PM CDT SUN APR 27 2014/ SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...CONCUR WITH THE GFS/NAM THAT AN UPPER LOW WILL MEANDER OVER THE PLAINS DRG THE PERIOD WITH EMBEDDED DISTURBANCES/SHORTWAVES MOVG WWD ACRS SOUTH CENTRAL TX AND AN UPPER JET ACRS NRN/CNTRL TX. THUS MUCH OF THE DYNAMICS WILL REMAIN NORTH OF THE CWA/MSA. ANTICIPATE THE DEVELOPMENT OF RADIATIONAL FOG EARLY MONDAY OVER THE ERN CWA PER NAM SOUNDINGS/SREF OUTPUT. SUFFICIENT MSTR PER NAM PWAT AND LIMITED DYNAMICS MAY RESULT IN ISOLD CONVECTION NEAR THE COAST EARLY MONDAY BEFORE SIGNIFICANT DRYING OCCURS. THE DRY LINE IS EXPECTED TO MOVE ACRS THE CWA AGAIN RESULTING IN HOT CONDITIONS MONDAY AFTN AT LEAST OVER THE CNTRL/WRN SECTIONS. MARINE...EXPECT SCA CONDITIONS TO PERSIST OVER THE COASTAL WATERS OVERNIGHT PER NAM DETERMINISTIC/UPPER JET DYNAMICS TO THE NW. ANTICIPATE THAT SCA CONDITIONS OVER THE SRN BAYS WL CONTINUE AT LEAST UNTIL 03Z MONDAY YET CONFIDENCE NOT TOO GREAT. PATCHY SEA FOG EXPECTED OVER THE BAYS/COASTAL WATERS TONIGHT WHEN CONSIDERING SFC DEW POINTS/SST VALUES/WIND. LIKELIHOOD FOR SEA FOG DECREASES AFTER 12Z MONDAY OWING TO FCST WIND PATTERN. PATCHY SEA FOG EXPECTED TO DEVELOP AGAIN OVER THE COASTAL WATERS DRG THE 00-09Z TUESDAY PERIOD BEFORE WIND BECOMES UNFAVORABLE AGAIN. LONG TERM (TUESDAY THROUGH SUNDAY)...FRONTAL BOUNDARY WILL MOVE THROUGH THE CWA SOMETIME BETWEEN 12Z AND 18Z ON TUESDAY. GFS NAM AND SREF OUTPUT ALL GENERALLY AGREEING ON AN EARLIER FRONTAL PASSAGE AROUND 12Z...WITH ECM FAVORING A PASSAGE CLOSER TO 18Z. WITH THE COOLER AIRMASS MOVING IN BEHIND THE FRONT...THIS MAKES FOR A RATHER UNCERTAIN HIGH TEMPERATURE FORECAST SINCE ITS HARD TO GAUGE HOW MUCH TEMPERATURES ARE GOING TO WARM UP IN ADVANCE OF THE FRONT. REGARDLESS...THERE IS NOT MUCH OF A CHANCE FOR PRECIPITATION DUE TO INSUFFICIENT MOISTURE. DECIDED TO GO COOLER RATHER THAN WARMER DUE TO MORE NWP MODELS CALLING FOR THE EARLIER PASSAGE. HIGH PRESSURE SURFACE RIDGE SETTLES IN BEHIND THE FRONT AND DOESNT REALLY GO ANYWHERE UNTIL SATURDAY. ADDITIONALLY...PERSISTENT MID LEVEL GENERALLY WESTERLY FLOW ALOFT WILL PREVAIL DURING THIS TIME ON THE SOUTH SIDE OF A LARGE AND SLOW MOVING CLOSED UPPER LEVEL LOW CENTERED OVER THE MIDWEST. WINDS AT THE SURFACE WILL REMAIN NE ON WED AND THEN BECOME MORE EASTERLY ON THURSDAY AND FRIDAY. MAY SEE SOME SCEC/SCA CONDITIONS OFFSHORE WEDNESDAY AND THURSDAY AS THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO A SURFACE TROUGH LOCATED OVER THE YUCATAN. THURSDAY AND FRIDAY WILL SEE MORE MID LEVEL MOISTURE AND THUS MORE CLOUD COVER...KEEPING TEMPERATURES COOLER. A STRONG SHORTWAVE DISTURBANCE IS FORECAST TO MOVE OVERHEAD FRIDAY...BUT THE BEST MOISTURE AVAILABILITY SHOULD BE TOO FAR SOUTH FOR ANY DECENT POPS. HAVE STILL INCLUDED 20 POPS OVER THE OFFSHORE WATERS AS MOISTURE CONTENT LOOKS AS IF IT WILL BE SLIGHTLY HIGHER THERE. OVER THE WEEKEND...SURFACE HIGH PRESSURE FINALLY SHIFTS OFFSHORE...WITH MODERATE TO STRONG SOUTHEASTERLY FLOW RETURNING AS A RESULT. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 66 85 60 84 60 / 10 10 10 10 10 VICTORIA 64 82 54 81 53 / 10 10 10 10 10 LAREDO 68 89 60 86 60 / 10 10 10 10 10 ALICE 64 86 57 84 56 / 10 10 10 10 10 ROCKPORT 68 84 63 83 61 / 10 10 10 10 10 COTULLA 62 86 55 84 55 / 0 0 10 10 10 KINGSVILLE 65 88 58 83 58 / 10 10 10 10 10 NAVY CORPUS 69 83 64 80 64 / 10 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 2 AM CDT EARLY THIS MORNING FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O`CONNOR. SMALL CRAFT ADVISORY UNTIL 5 AM CDT EARLY THIS MORNING FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM. && $$ GW/86...AVIATION
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1148 PM CDT SUN APR 27 2014 .UPDATE... FORECAST IS ON TRACK. POPS OF 20-30 PERCENT OVER THE EAST SHOULD COVER ISOLATED TO SCATTERED NATURE OF SEVERE CONVECTION...BUT DID EXTEND DURATION FROM 6Z TO 9Z. UPDATED TEXT PRODUCTS TO INCLUDE MENTION OF NEW TORNADO WATCH. WHILE LARGE HAIL IS THE MAIN THREAT...ANY SUPERCELL STORMS WILL HAVE THE ABILITY TO OVERCOME LOW LEVEL INHIBITION AND ACCESS NEAR SURFACE AIR PARCELS WHICH WILL INCREASE THE RISK FOR ROTATION AND TORNADOGENESIS. THIS IS MOST LIKELY PARTICULARLY ACROSS THE SOUTHEAST ZONES WHERE CIN IS LOWEST. TR.92 && .AVIATION... ALL CURRENT CONVECTION FIRING EAST OF TAF SITES AND WILL CONTINUE TO MOVE EAST AWAY FROM THE TRACON. OTHERWISE...VFR FORECAST WITH NO CONCERNS. MID-HIGH CLOUDS WILL BE IN PLACE OVERNIGHT...BUT SHOULD SCATTER OUT TOMORROW...ONLY TO ARRIVE AGAIN MONDAY EVENING. LIGHT SOUTHWEST WINDS TONIGHT WILL BECOME NORTHWEST BEHIND A WEAK FRONT BY SUNRISE. WITH DEEP MIXING...WINDS SHOULD TURN TO A MORE WESTERLY DIRECTION AT SPEEDS NEAR 15KT TOMORROW AFTERNOON. SPEEDS LIKELY NOT HIGH ENOUGH TO CAUSE MAJOR ISSUES WITH N-S RUNWAYS. TR.92 && .UPDATE... LATEST MESO-ANALYSIS INDICATED A STATIONARY DRY LINE FROM BONHAM TO MESQUITE TO NEAR CAMERON. MEANWHILE A PACIFIC COLD FRONT WAS JUST A FEW MILES TO ITS WEST...ALONG A LINE SHERMAN TO FORT WORTH TO LAMPASAS. WINDS BEHIND THE FRONT WERE STRONGER AND FROM THE WEST BUT RAPID BOUNDARY LAYER DECOUPLING SHOULD OCCUR IN THE NEXT HOUR WITH WINDS DROPPING BELOW WIND ADVISORY CRITERIA. EXPIRED WIND ADVISORY ON TIME AT 7 PM. MORE CONCERNING WITH THE FORECAST IS THE CONVECTIVE POTENTIAL THIS EVENING. WITH THE SUN SETTING...THE THREAT FOR INITIATION OF SURFACE BASED CONVECTION ALONG THE DRY LINE WILL WANE DUE TO INCREASING CIN AND THE SEVERE WATCH WILL LIKELY EXPIRE AT 8PM. THE DRY LINE WILL MOVE BACK TO THE WEST AFTER SUNSET AS IS OFTEN THE CASE...LIKELY MEETING OR PERHAPS ALSO PUSHING THE PACIFIC FRONT BACKWARD. THE FRONT IS AWAITING A PUSH FROM A STRONG SHORTWAVE THAT WILL ARRIVE LATER THIS EVENING...WITH STRONG UPWARD FORCING BEGINNING TO SPREAD ACROSS THE REGION AFTER 10 PM. WHILE SURFACE BASED CONVECTION FIRING ALONG A WESTWARD RETREATING DRY LINE DURING THE EVENING IS RARE DUE TO INCREASED CIN...IT DOES HAPPEN OCCASIONALLY. INSTEAD WHAT IS LIKELY TO HAPPEN IS THAT UPWARD FORCING OCCURRING IN THE PRESENCE OF NEARLY DRY ADIABATIC LAPSE RATES UP TO 14000 FEET WILL SQUEEZE OUT WHATEVER MOISTURE IT CAN FIND FOR ELEVATED HIGH BASED CONVECTION. MODEL SOUNDINGS FROM THE RAP ARE MOST AGGRESSIVE WITH THIS SCENARIO...AND SUGGEST ISOLATED TO SCATTERED ELEVATED THUNDERSTORMS DEVELOPING ALONG THE I-35 CORRIDOR AND GATHERING STRENGTH AS THEY HEAD INTO THE DEEPER MOISTURE ACROSS THE EASTERN ZONES. OBVIOUSLY ANY STORMS IN THIS ENVIRONMENT WILL HAVE A LARGE HAIL THREAT. WHILE THIS IS A POSSIBLE SCENARIO...IT IS UNCERTAIN RIGHT NOW HOW LIKELY IT IS. THEREFORE WE WILL KEEP POPS AT 20-30 PERCENT THROUGH 1 AM OVER AREAS JUST EAST OF I-35 AND CONTINUE TO WATCH TRENDS IN SATELLITE AND RADAR DATA FOR ADDITIONAL DEVELOPMENT LATER THIS EVENING. TR.92 && .PREV DISCUSSION... /ISSUED 319 PM CDT SUN APR 27 2014/ DRYLINE/SURFACE TROUGH CONTINUES MOVING EAST AND CURRENTLY EXTENDED FROM NEAR BONHAM...TO DALLAS...TEMPLE AND WAS MOVING SLOWLY EAST. ONE ISOLATED STRONG STORM WAS UP NEAR BONHAM WITH ANOTHER POTENTIALLY DEVELOPING CELL OVER EASTERN COLLIN CO... OTHERWISE IT REMAINED QUIET. DESPITE SURFACE DEW POINTS BETWEEN 65-70 DEGREES...WARM TEMPERATURES...INSTABILITY ABOVE 2000 J/K AND GOOD SHEAR...LOW LEVEL CONVERGENCE ACROSS OUR CENTRAL TEXAS COUNTIES WAS NOT AS GOOD DUE TO SLIGHTLY VEERED FLOW AHEAD OF THE DRYLINE. THIS MAY CHANGE AS A 300MB SPEED MAX CONTINUES ROTATING NORTHEAST THROUGH 00Z AND HELPS TRIGGER ISOLATED STORMS...POSSIBLY MORE SCATTERED IN THE FAR E/NE FROM CORSICANA/ATHENS NORTHWARD. QUICK CHAT WITH SPC WAS THAT CURRENT SEVERE THUNDERSTORM WATCH 94 WOULD BE ALLOWED TO EXPIRE AT 3 PM AND REPLACED BY SEVERE THUNDERSTORM WATCH 99 FOR OUR FAR EAST CENTRAL AND NORTHEAST COUNTIES THROUGH 8 PM. SEVERE STORMS ARE ALREADY DEVELOPING RAPIDLY AND BECOMING SEVERE BETWEEN BONHAM AND PARIS WITH OTHER SIGNS OF DEVELOPMENT SOUTHWEST TOWARD ROCKWALL AND TERRELL. LOOK FOR A 10-30 PERCENT COVERAGE OF POSSIBLE STRONG TO SEVERE STORMS ACROSS THE EASTERN THIRD OF NORTH TEXAS INTO EARLY EVENING WITH HAIL AND DAMAGING WINDS THE MAIN THREATS DUE TO THE AFOREMENTIONED SLIGHTLY VEERED FLOW AHEAD OF THE DRYLINE. BEHIND THE DRYLINE...GUSTY WEST-SOUTHWEST WINDS 20 TO 30 MPH WITH GUST 35 TO 40 MPH ARE EXPECTED AND MAY RESULT IN SOME BLOWING DUST FROM THE DFW METROPLEX NORTH AND WEST THROUGH MID EVENING. BEYOND MID EVENING...WE EXPECT THE DRYLINE TO REACH OUR EASTERN EDGE AND RISK FOR SEVERE STORMS MOVING INTO EAST TEXAS...THE ARKLATEX AND MID MS VALLEY. DRIER AIR TONIGHT COMBINED WITH DIMINISHING WEST WINDS SHOULD ALLOW FOR A COOL AND PLEASANT NIGHT...BEFORE ANOTHER WINDY... DRY AND VERY WARM DAY ENSUES MONDAY WITH FIRE WEATHER CONCERNS AND POSSIBLY ANOTHER WIND ADVISORY NEEDING TO BE ISSUED. WEST- SOUTHWEST WINDS 15-25 MPH AND GUSTY ARE EXPECTED OR POSSIBLY SLIGHTLY HIGHER BY MONDAY AFTERNOON. THE FIRST OF SEVERAL COLD FRONTAL SURGES IS EXPECTED TO ARRIVE MONDAY NIGHT INTO TUESDAY MORNING. MEANWHILE...ANOTHER STRONG CYCLONICALLY CURVED SHORTWAVE WILL ROTATE ACROSS THE RED RIVER WITH MOST MOISTURE ANCHORED ABOVE 700MB. ONLY MENTIONED ISOLATED HIGH-BASED OR ELEVATED SHOWERS FOR THIS PERIOD...THOUGH EVENTUALLY THUNDER MAY NEED TO BE INTRODUCED IF LAPSE RATES REMAIN HIGH. THE LOW LEVELS WILL REMAIN VERY DRY...SO LITTLE MEASURABLE RAINFALL WOULD OCCUR WITH THE FRONTAL PASSAGE. MAY WELL BE JUST SOME VIRGA WOULD COULD POSSIBLY TRANSLATE SOME GUSTIER NORTHWEST WINDS DOWN THE SURFACE BY TUESDAY MORNING. AFTERWARD...A DRY AND SEASONABLY COOL PERIOD IS EXPECTED WITH THE DRY CONTINENTAL AIRMASS BEING SUPPORTED BY STALLING AND OCCLUDING UPPER LOW PIN-BALLING OVER THE MID MISSISSIPPI VALLEY AND MIDWEST. AS NOTED IN PREVIOUS DISCUSSIONS...THE REASON FOR THE UPPER LEVEL LOW REMAINING STATIONARY IS A BLOCKING UPPER HIGH OVER EASTERN CANADA. THE AIRMASS WILL BE UNUSUALLY DRY FOR HEADING INTO EARLY MAY AND ALLOW FOR A LARGE DIURNAL RANGE ON LOWS AND HIGHS WITH 45-50 FOR LOWS AND HIGHS 70-75...EXCEPT SLIGHTLY WARMER OVER CENTRAL TEXAS. FLOW ALOFT OVER NORTH TEXAS DAMPENS BY NEXT WEEKEND AS THE EASTERN CANADIAN RIDGE FINALLY WEAKENS AND ALLOW THE OCCLUDED UPPER LOW TO BE OPENED UP AND CARRIED QUICKLY EAST. SOUTHERLY LOW LEVEL FLOW THEN RETURNS AND HIGHS REBOUND BACK INTO THE 80S. 05/ && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 58 84 52 75 50 / 5 5 10 10 5 WACO, TX 56 87 51 80 47 / 10 5 5 5 5 PARIS, TX 57 79 51 72 46 / 30 5 10 10 5 DENTON, TX 52 84 48 74 45 / 5 5 10 5 5 MCKINNEY, TX 53 84 49 73 46 / 20 5 10 10 5 DALLAS, TX 62 86 54 75 51 / 10 5 10 10 5 TERRELL, TX 57 83 52 75 47 / 30 5 10 10 5 CORSICANA, TX 58 86 55 78 48 / 30 5 5 10 5 TEMPLE, TX 59 88 55 79 48 / 20 5 5 5 5 MINERAL WELLS, TX 52 87 49 76 47 / 5 5 10 10 5 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1142 PM CDT SUN APR 27 2014 .DISCUSSION... 06Z TAF DISCUSSION IN AVIATION SECTION. && .AVIATION... DRYLINE/PAC FRONT LOOKS TO BE MAKING SOME PROGRESS THROUGH C TX TONIGHT. HRRR AND EVEN NAM HINTING AT POSSIBILITY OF CONVECTION DURING THE MORNING HOURS AS BOUNDARY MOVES SOUTH. BASED OFF EVENING SOUNDING DATA THINK CAP MAY BE TOO STRONG FOR CONVECTION BUT WORTH NOTING. WILL LEAVE OUT MENTION OF TSRA IN TAFS FOR NOW. CONVECTION ALONG BOUNDARY MAY SUGGEST THESE MODELS ARE ON THE RIGHT TRACK. OTHERWISE EXPECT IFR/MVFR CIGS UNTIL BOUNDARY PUSHES SOUTH WITH DRIER AIR BEHIND IT. HAVE CLEAR SKIES FOR TOMORROW AFTERNOON. BOUNDARY MAY PUSH BACK NORTH WITH MOISTURE SOUTH OF THE FRONT. COULD GET LOW CLOUD DECKS AGAIN. 39 && .PREV DISCUSSION... /ISSUED 1120 PM CDT SUN APR 27 2014/ UPDATE... UPDATED THE FORECAST FOR TORNADO WATCH 105 ISSUED UNTIL 5 AM THAT INCLUDES HOUSTON AND TRINITY COUNTIES. ADDED ISOLATED SEVERE THUNDERSTORMS FOR BOTH COUNTIES. 40 PREV DISCUSSION... /ISSUED 940 PM CDT SUN APR 27 2014/ DISCUSSION... ISOLATED STRONG TO SEVERE THUNDERSTORMS THAT OCCURRED ALONG HIGHWAY 290 IN WESTERN AND CENTRAL WASHINGTON COUNTY HAVE WEAKENED. AS THE DRY LINE MOVES INTO SE TX...ISOLATED SHOWERS OR THUNDERSTORMS MAY DEVELOP LATER TONIGHT. AFTER LOOKING AT THE SHORT RANGE MODELS...IT APPEARS THAT THE BEST LOCATIONS ARE GENERALLY ALONG AND NORTH OF A LINE FROM BRENHAM TO CLEVELAND. THE 00Z RUN OF THE NAM12 WEAKENS THE LOW-LEVEL JET OVERHEAD OF THE AREA LATER THIS EVENING. WITH THIS IN MIND...TOOK OUT THE MENTION OF DRIZZLE FOR THE REMAINDER OF THE NIGHT. 40 PREV DISCUSSION... /ISSUED 752 PM CDT SUN APR 27 2014/ UPDATE... UPDATE FOR ISOLATED THUNDERSTORMS MOVING TOWARD BURLESON AND WASHINGTON COUNTIES FROM THE WEST. 40 DISCUSSION... DRY LINE/COLD FRONT APPROACHING FROM THE WEST. ISOLATED THUNDERSTORMS HAVE DEVELOPED AHEAD OF THE DRY LINE IN BASTROP AND LEE COUNTIES AND WERE MOVING INTO BURLESON AND WASHINGTON COUNTIES. LARGE HAIL HAS BEEN REPORTED...BUT THE STORM MOVING THROUGH BURLESON COUNTY WEAKENED BEFORE MOVING INTO THE COUNTY. THE 00Z CRP SOUNDING HAD A SURFACE BASED CAPE OF ALMOST 4700... ALTHOUGH THERE WAS A DECENT CAP IN PLACE. ISOLATED STRONG TO SEVERE STORMS ARE POSSIBLE THROUGH MID EVENING AS THE STORMS THAT DO DEVELOP MOVE OFF THE DRYLINE...ESPECIALLY ALONG AND NORTH OF A LINE FROM BRENHAM TO HUNTSVILLE. DO EXPECT THE STORMS TO BEGIN LOSING INTENSITY DURING THE LATE EVENING DUE TO THE LOSS OF DAYTIME HEATING. 40 PREV DISCUSSION... /ISSUED 641 PM CDT SUN APR 27 2014/ DISCUSSION... 00Z TAF DISCUSSION IN AVIATION SECTION. AVIATION... SFC ANALYSIS HAS DRYLINE ALONG THE I-35 CORRIDOR WITH A FEW ISO STORMS WEST OF KAUS. CAP EAST OF THESE STORMS PROBABLY STRONG ENOUGH THAT THE STORMS SHOULD WEAKEN BEFORE REACHING KCLL SO WILL CONTINUE TO MONITOR. LEFT TAF VOID OF CONVECTION AS PROBABILITIES SMALL AT THIS POINT. MAIN CONCERN WILL BE LOW MVFR CIGS AHEAD OF WEAK PACIFIC FRONT. DRIER AIR SHOULD MIX INTO THE AREA BY THE MORNING HOURS AND HELP SCT OUT CIGS 12-15Z WITH MAINLY CLEAR SKIES AFTER THAT. WINDS SHOULD TURN TO THE WSW/WNW DIRECTIONS AROUND 10KTS. BOUNDARY SHOULD WORK BACK NORTH MONDAY NIGHT WITH STRONGER PACIFIC FRONT ON TUESDAY. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 65 91 62 82 51 / 20 10 10 10 10 HOUSTON (IAH) 72 91 68 86 55 / 20 20 10 10 10 GALVESTON (GLS) 73 82 72 82 62 / 20 10 10 20 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. SMALL CRAFT ADVISORY UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...40 AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
402 AM EDT MON APR 28 2014 .SYNOPSIS... A WEAK STATIONARY FRONT WILL REMAIN JUST SOUTH AND WEST OF THE REGION TODAY INTO TUESDAY. A LARGE AND COMPLEX STORM SYSTEM LOCATED OVER THE CENTRAL UNITED STATES WILL SLOWLY MOVE EAST. THIS SYSTEM WILL PROVIDE RAINFALL FOR MUCH OF THE UPCOMING WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 250 AM EDT MONDAY... WEAK BACKDOOR TYPE COLD FRONT NOW HEADING INTO THE SW PORTIONS OF THE CWA WITH A STIFF EASTERLY FLOW DEVELOPING ESPCLY EAST OF THE BLUE RIDGE WHERE BEST COOL ADVECTION WILL TAKE SHAPE THIS MORNING. INIT MID LEVEL WAVE EJECTING OUT INTO THE SHORTWAVE RIDGING ALOFT LIKELY TO HELP MOISTEN THE COLUMN EARLY ON WITH MAINLY JUST SPOTTY -RA OR SPRINKLES INTO MID MORNING PER LATEST RADAR TRENDS. MAIN SHOT AT MORE WIDESPREAD RAINFALL LOOKS TO COME FROM LATE MORNING INTO MID AFTERNOON AS ANOTHER WAVE SLIDES BY TO THE NW AND HELPS UPWARD MOTION SWING ACROSS THE NORTH UNDER A CORE OF SLIGHTLY HIGHER 85H WINDS. MOST GUIDANCE ON TRACK WITH THIS FEATURE WITH THE LATEST HRRR EXPANDING THIS AXIS EAST TO ALONG THE BLUE RIDGE AROUND MIDDAY BEFORE TAKING IT TO THE EAST DURING THE AFTERNOON ALONG THE GRADIENT OF THE THETA-E AXIS ALOFT. THUS HAVE INCLUDED SOME CHANCE POPS MAINLY WEST EARLY THIS MORNING...THEN A PERIOD OF LIKELYS FROM WEST TO EAST THROUGH LATE AFTERNOON WHEN SEE BEST OVERRUNNING. HOWEVER QPF DOESNT LOOK TOO IMPRESSIVE WITH THIS FEATURE WITH A TENTH TO A QUARTER INCH POSSIBLE WITH ANY THUNDER FAR WEST AWAY FROM THE DEVELOPING EASTERN WEDGE. HIGH TEMPS REMAIN TRICKY AS COULD SEE AREAS ACROSS THE NE ONLY RISE A FEW DEGREES WHILE JUMPING ABOVE 70 ALONG THE I-77 CORRIDOR. WENT CLOSER TO THE COLDER MET MOS ALONG/EAST OF THE BLUE RIDGE AND A BLEND OUT WEST. IMPULSE EXITS BY THIS EVENING LEAVING MOST OF THE REGION IN A STRONG WEDGE WITH ABSENCE OF MUCH LIFT WITH A BAND OF DEEPER CONVECTION APPROACHING THE MOUNTAINS FROM THE WEST LATE. HOWEVER SOUNDINGS SHOW A RATHER DEEP EAST/SE LOW LEVEL FLOW UNDER VEERING ALOFT WHICH WOULD SUPPORT AT LEAST SPOTTY -RA/DZ OUTSIDE THE FAR WEST WITH ADDED UPSLOPE LIKELY ENHANCING COVERAGE EASTERN SLOPES OF THE BLUE RIDGE. WEAKENING SHRA/TSRA HEADED IN FROM THE WEST AROUND DAYBREAK COULD REACH THE WESTERN SLOPES SO KEPT IN SOME THUNDER MENTION ON THE PERIMETER OF THE WEDGE FOR NOW OVERNIGHT. OTRW CLOUDY AND DAMP WITH PERIODS OF -RA/DZ AND PERHAPS A FEW MORE -SHRA SW AS DEEPER WARM ADVECTION SPREADS NORTH ALOFT LATE. KEPT LOWS CLOSER TO THE COOLER MET MOS AGAIN IN EXPECTING A STRONGER WEDGE IN THE WAKE OF EARLIER RAINFALL. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM EDT MONDAY... DEEP UPPER CLOSED LOW OVER IOWA AND THE UPPER RIDGE ALONG THE EAST COAST WILL MOVE EAST DURING THE PERIOD. THE MAIN LOW MOVES EAST ACROSS THE GREAT LAKES WHILE A WAVE OF LOW PRESSURE ALONG THE FRONTAL BOUNDARY WILL TRACK TOWARD THE MISSISSIPPI RIVER BY TUESDAY EVENING. PLENTY OF MOISTURE IS TRANSPORTED INTO THE REGION FROM THE ATLANTIC OCEAN AT LOWEST LEVELS AND FROM THE GULF OF MEXICO THROUGH A DEEP LAYER FARTHER ALOFT. HIGH TEMPERATURES ON TUESDAY ARE TRICKY DEPENDING SUNSHINE AND AMOUNT OF RAIN. PLAYED HIGHS TOWARDS THE COOLER ADJMET WITH VALUES FROM THE UPPER 50S ACROSS THE NORTH TO THE LOWER 70S ACROSS THE SOUTH. THE SWODY2 HAS A FEW SOUTHEAST COUNTIES IN THE SLIGHT RISK FOR SEVERE THUNDERSTORMS. APPEARS THAT THEY ARE ALLOWING THE WEDGE TO WEAKEN ON THE SOUTHERN END FOR A FEW HOURS. WITH THE STRENGHT OF THE WEDGE...GENERALLY UNDERDONE ON THE MODELS...QUESTIONS ON WHETHER THE WEDGE MIXES OUT FOR A FEW HOURS TUESDAY AFTERNOON. BEST Q-V FORCING AND UPPER DIFFLUENCE IN THE RIGHT REAR QUADRANT OF THE UPPER JET WILL BE TUESDAY NIGHT AND WEDNESDAY. PRECIPITABLE WATER VALUES RISE TO AS HIGH AS 1.6 INCHES ACROSS THE SOUTHERN AND EASTERN COUNTY WARNING AREA TUESDAY...WHICH IS AROUND TWO STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR. KEPT THE HIGHEST QPF IN THE TUESDAY NIGHT TO WEDNESDAY TIME FRAME...SIMILAR TO WPC GUIDANCE. HPC HAS PLACED EXCESSIVE RAINFALL POTENTIAL FOR DAY 2-3 ALONG AND EAST OF THE BLUE RIDGE. HOWEVER WILL HOLD OFF ON A FLOOD WATCH FOR NOW GIVEN INTERVALS OF HEAVY RAIN AND WHERE EXCESSIVE MAY OCCUR BASED ON RAINFALL THROUGH MONDAY NIGHT. THUS WILL MENTION FLOODING POTENTIAL IN THE HWO FOR TUESDAY INTO WEDNESDAY. CLOUDS MAY HOLD UP LOW TEMPERATURES TUESDAY NIGHT. PLAYED OVERNIGHT LOW TEMPERATURES FOR THE LOWER 50S IN THE NORTHERN MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT. WEDNESDAY LOOKS MORE UNSTABLE WITH LIS AROUND MINUS 5 AND CAPES POTENTIALLY EXCEEDING 2000 J/KG. INCREASED THE COVERAGE OF THUNDERSTORMS WEDNESDAY. THE SWODY3 HAS MUCH OF THE CWA IN THE SLIGHT RISK AHEAD OF THE COLD FRONT. THE MAIN THREAT WILL BE DAMAGING WINDS. HIGH TEMPERATURES ON WEDNESDAY WILL BE WARMER THAN TUESDAY WITH READINGS FROM THE UPPER 60S IN THE MOUNTAINS TO THE MID 70S IN THE PIEDMONT. TAPER POPS OFF WEDNESDAY NIGHT INTO THURSDAY. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE THE MID 40S IN THE MOUNTAINS TO AROUND 60 DEGREES IN THE PIEDMONT. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 300 PM EDT SUNDAY... ON THURSDAY...THE CLOSED UPPER LOW WILL BE OVER THE GREAT LAKES WITH THE LARGE TROF COVERING MUCH OF THE CENTRAL AND EASTERN UNITED STATES. THE PATTERN REMAINS AMPLIFIED THROUGH SATURDAY BUT THE REX BLOCK WEAKENS...THE LOW OPENS UP AND THE TROF GRADUALLY MOVES EAST BY SATURDAY. A SHORT WAVE TRACKING THROUGH THE BASE OF THE UPPER TROF WILL MOVE ACROSS THE TENNESSEE VALLEY ON SATURDAY. A STRONGER SHORT WAVE MOVES INTO THE TROF AXIS FROM SOUTHERN CANADA AND CLOSES OFF OVER THE UPPER MISSISSIPPI VALLEY ON SUNDAY. ECMWF WAS SHOWING A WAVE ALONG THE SURFACE FRONT WHICH WILL LIKELY SLOW THE PASSAGE OF THE BOUNDARY ACROSS THE AREA ON WEDNESDAY NIGHT AND THURSDAY. THE FRONT SHOULD BE WELL OFF THE SOUTHEAST COAST ON FRIDAY. FRIDAY NIGHT THROUGH SUNDAY HIGH PRESSURE IS BUILDING OVER THE GULF OF MEXICO AND THE SOUTHEAST UNITED STATES. MODELS STILL BRING UNSEASONABLY COLD AIR INTO THE AREA BEHIND THIS SYSTEM ON THURSDAY NIGHT AND FRIDAY. SUNDAY MORNING HAS THE POTENTIAL TO REACH WELL INTO THE 30S FOR LOWS IN THE MOUNTAINS. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... AS OF 1255 AM EDT MONDAY... INCREASINGLY MOIST EASTERLY FLOW WILL CONTINUE OVERNIGHT INTO MONDAY WITH THE CURRENT VFR CIGS/VSBYS DETERIORATING TOWARD MVFR ESPCLY ALONG THE BLUE RIDGE AND POINTS EAST BY DAYBREAK. CONDITIONS MAY IMPROVE MID- MORNING FOR SEVERAL HOURS BEFORE THE ONSET OF LIGHT SHOWERS BY EARLY THIS MORNING AS A WEAK RIPPLE OF ENERGY SLIDES ACROSS THE REGION PROVIDING ANOTHER BOOST TO LOW LEVEL MOISTURE. BETTER MOISTURE ADVECTION SHOULD PRODUCE LOWER CIGS AND INCREASING PRECIPITATION CHANCES AGAIN BY AFTERNOON WITH A LOBE OF SHOWERS PROGGED TO MOVE EAST THROUGH THE AREA AHEAD OF ANOTHER MID LEVEL WAVE ALOFT...WITH EVEN SOME CHANCE FOR THUNDER BUT MUCH BETTER CHANCES TO OUR SOUTH AND WEST MONDAY AFTERNOON. LATEST GUIDANCE SUGGESTS THAT ONCE THE INITIAL PATCHY RAINFALL EXITS AND THE WEDGE BECOMES BETTER ENHANCED WILL SEE FLYING CONDITIONS QUICKLY WORSEN LATER THIS AFTERNOON WITH STRATUS/FOG DEVELOPING IN MANY LOCATIONS MAKING FOR WIDESPREAD MVFR TO IFR FOR ALL SITES WITH LIFR POSSIBLE ESPCLY AROUND BCB/ROA TO THE EAST. THIS MAY ACTUALLY OCCUR WITH LACK OF PRECIP THIS EVENING AS THE MAIN BATCH OF CONVECTION AHEAD OF THE FRONT ALOFT REMAINS OFF TO THE WEST. EXTENDED AVIATION DISCUSSION... MUCH OF THE UPCOMING WEEK WILL BE DOMINATED BY CLOUD COVER AS A DEEP AREA OF LOW PRESSURE ALOFT SLOWLY DRIFTS INTO THE REGION FROM THE WEST. ONCE THIS SYSTEM ARRIVES...IT WILL LINGER ACROSS THE REGION FOR SEVERAL DAYS. SUB VFR CONDITIONS CAN BE EXPECTED AT INCREASING FREQUENCY AS THE WEEK PROGRESSES WITH POTENTIAL FOR SCATTERED SHRA/TSRA IN ADDITION TO AREAS OF LIGHT RAIN AND DRIZZLE NEAR THE BLUE RIDGE. APPEARS ENOUGH DRYING ALOFT TO PERHAPS SEE IMPROVEMENT TO VFR ACROSS THE EAST LATER THURSDAY INTO FRIDAY WITH MVFR LIKELY LINGERING AT TIMES ACROSS THE SE WEST VA LOCATIONS INTO FRIDAY. && .HYDROLOGY... AS OF 300 PM EDT SUNDAY... THERE IS A CHANCE FOR MAINSTEM RIVER FLOODING BY MID TO LATE THIS WEEK. BUT STILL FAR TOO EARLY FOR HIGH CONFIDENCE IN WHICH RIVERS AND HOW WIDESPREAD FLOODING WILL BE. STAY TUNED. PATTERN SETTING UP WITH SOME IMPRESSIVE STRONG SIGNALS FOR A PROLONGED PERIOD OF RAINFALL WITH HEAVY RAIN AMOUNTS BECOMING MORE LIKELY...ESPECIALLY TUESDAY AFTERNOON INTO WEDNESDAY. LATEST RUNS OF ENSEMBLE MODEL FORECAST FROM THE GEFS AND THE NAEFS WERE SUGGESTING AN INCREASING PROBABILITY OF MODERATE RIVER FLOODING ON THE DAN RIVER AT SOUTH BOSTON AND ON THE ROANOKE AT RANDOLPH. FLOODING POSSIBILITIES ARE ALSO INDICATED FOR PARTS OF THE JAMES AND GREENBRIER RIVER BASINS. FLASH FLOODING APPEARS TO BE LESS OF A LIKELIHOOD AT LEAST AT THE ONSET AS MUCH OF THE RAINFALL WILL BE OF THE STRATIFORM VARIETY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/PC/WP NEAR TERM...JH SHORT TERM...KK LONG TERM...KK AVIATION...JH/KM/PC/PM HYDROLOGY...AMS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1110 PM CDT SUN APR 27 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 313 PM CDT SUN APR 27 2014 CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED TROUGHING ALONG THE BRITISH COLUMBIA COAST...A POTENT NEGATIVELY TILTED TROUGH AND UPPER LOW OVER KANSAS...AND A STRONG UPPER LEVEL RIDGE FROM THE SOUTHEASTERN U.S. INTO MANITOBA. IN- BETWEEN THE UPPER LOW AND RIDGE...PROFILER AND VWP DATA SHOWED A 30- 50 KT JET CORE AT 850MB FROM THE WESTERN GULF OF MEXICO NORTHWARD THROUGH MINNESOTA RAPIDLY TRANSPORTING MOISTURE NORTHWARD. GOES PRECIPITABLE WATER IMAGERY DEPICTED VALUES OF 1-1.5 INCHES ENCOMPASSING MUCH OF IOWA SOUTHWARD INTO LOUISIANA...WITH LOWER VALUES OF LESS THAN 0.5 INCH OVER MUCH OF KANSAS INTO WESTERN OKLAHOMA WHERE A DRY SLOT EXISTS. ALONG AND JUST EAST/NORTHEAST OF THIS GRADIENT OF PRECIPITABLE WATER...NUMEROUS SHOWERS AND THUNDERSTORMS HAVE DEVELOPED FROM CENTRAL IOWA AND MISSOURI. SOME OF THESE STORMS ARE INTENSE TOO...MOSTLY SOUTH OF I-80 WHERE 750-1500 J/KG OF MLCAPE EXISTS PER RAP ANALYSIS. FARTHER NORTHEAST... SHOWERS AND EMBEDDED THUNDERSTORMS THAT AFFECTED THE FORECAST AREA THIS MORNING HAVE MOSTLY LIFTED NORTH OF I-90. THESE ARE ASSOCIATED WITH MID-LEVEL FRONTOGENESIS AND RIGHT ENTRANCE REGION OF AN UPPER JET OVER LAKE SUPERIOR. LASTLY...A TIGHT PRESSURE GRADIENT IN PLACE COMBINED WITH THAT AFOREMENTIONED STRONG 850MB JET CORE HAS LED TO BRISK EAST WINDS. THESE HAVE BEEN SUSTAINED AT 15-35 MPH WITH GUSTS OF 25-45 MPH...STRONGEST WEST OF THE MS RIVER. VERY GOOD MODEL AGREEMENT CONTINUES THAT THE BAND OF SHOWERS AND THUNDERSTORMS TO OUR SOUTHWEST WILL LIFT NORTHEAST THROUGH THE FORECAST AREA TONIGHT INTO MONDAY MORNING. THIS IS ALL IN RESPONSE TOO THE UPPER LOW AND ASSOCIATED SHORTWAVE TROUGH LIFTING INTO NEBRASKA AND IOWA BY 18Z MONDAY. THE QUESTION IS AMOUNT WHICH HAS BIG IMPACTS ON POTENTIAL FOR RIVER FLOODING. THE AMOUNT HAS STRONG TIES TO EVOLUTION OF CONVECTION OVER WESTERN MISSOURI AND SOUTHWEST IOWA IN WHICH THERE ARE THREE SCENARIOS... 1. THE CONVECTION TURNS INTO A FORWARD PROPAGATING SQUALL LINE...ESSENTIALLY LIMITING HEAVIER RAINFALL INTO THE FORECAST AREA. THIS SQUALL LINE FALLS APART OVER ILLINOIS LATE THIS EVENING AS IT RUNS INTO MORE STABLE AIR. 2. THE CONVECTION WEAKENS AS IT PUSHES EAST...RESULTING IN A PERSISTENT WARM CONVEYOR BELT OF SHOWERS AND EMBEDDED THUNDERSTORMS. THE TRAINING FACTOR COMES INTO PLAY...ALLOWING FOR HEAVIER RAINFALL...ESPECIALLY ACROSS NORTHEAST IOWA THIS EVENING. 3. THE CONVECTION WEAKENS AS IT PUSHES EAST...AND ESSENTIALLY MUCH OF THE SHOWER ACTIVITY FALLS APART BY 04Z. ALL THREE IDEAS ARE CERTAINLY PLAUSIBLE...BUT IT IS SERIOUSLY WORTH NOTING THE CONVECTION HAS BEEN OUTRUNNING MOST MODELS. THE ONLY MODEL THAT HAS BEEN HANDLING THIS WELL IS THE 00Z SPC WRF-NMM... WHICH IS SCENARIO NUMBER 3 ABOVE. THEREFORE...HAVE TRIED TO LEAN MORE TOWARDS THAT FOR PRECIPITATION CHANCES AND QPF. STILL...THE FORECAST MAY BE OVERDONE...ESPECIALLY WITH PRECIPITATION CHANCES IN THAT 04-09Z TIME FRAME. WOULD THINK THAT PERSISTENT 850MB MOISTURE TRANSPORT WOULD AT LEAST CONTINUE SOME SHOWER ACTIVITY AND NOT COMPLETELY END...THUS THE HIGHER CHANCES IN THE FORECAST. ALL THREE SCENARIOS ABOVE REGENERATE SHOWERS AND EMBEDDED THUNDERSTORM ACTIVITY OVER THE FORECAST AREA AROUND 09Z...ASSOCIATED WITH DPVA FROM THE APPROACHING NEGATIVELY TILTED SHORTWAVE TROUGH. SEE HYDROLOGY SECTION BELOW FOR IMPACT ON RIVERS. AFTER THE RAIN AND CONVECTION TONIGHT/MONDAY MORNING...ATTENTION THEN TURNS TO A WARM FRONT PROGGED TO LIFT THROUGH IOWA. THE MAJORITY OF MODELS KEEP IT JUST SOUTH OF THE FORECAST AREA...EITHER ALONG OR SOUTH OF US-20. THE NORTHWARD PROGRESS OF THE FRONT HINGES QUITE A BIT ON MORNING PRECIPITATION. CONVECTION LOOKS LIKELY TO FIRE ALONG AND SOUTH OF THIS FRONTAL BOUNDARY. SOME OF THIS CONVECTION COULD CREEP INTO FAR SOUTHERN PORTIONS OF THE FORECAST AREA IN THE LATE AFTERNOON...AND POSSIBLY BE SEVERE. NOTE THAT A VERY TIGHT GRADIENT OF INSTABILITY WILL EXIST...SO ANY SEVERE THREAT SHOULD BE CONFINED TO FAYETTE EAST TO GRANT COUNTIES. LASTLY...REGARDING THE WIND ADVISORY...AS EXPECTED THE CONDITIONS HAVE BEEN MARGINAL. WILL KEEP IT GOING THROUGH 9 PM AS SUSTAINED SPEEDS CONTINUE TO PULSE UP AND DOWN TO 30 MPH. THERE IS A POSSIBILITY THE ADVISORY MAY NEED TO BE EXTENDED TO MIDNIGHT SEEING SOME LAV GUIDANCE HOLDING RST...TOB AND OLZ BETWEEN 25-30 KT TO 06Z. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 313 PM CDT SUN APR 27 2014 THE UPPER LOW OVER NEBRASKA ON MONDAY IS THE MAIN FEATURE OF FOCUS FOR THE LONG TERM PERIOD. MODELS CONTINUE TO SUGGEST THIS UPPER LOW WILL PLAGUE THE FORECAST AREA THROUGH AT LEAST THURSDAY AS IT SLOWLY TRACKS NORTHEAST INTO UPPER MICHIGAN. HEADING INTO THE WEEKEND...THE UPPER PATTERN REMAINS COOL AS RIDGING HOLDS IN PLACE OVER THE WESTERN U.S. INTO WESTERN CANADA...CAUSING TROUGHING TO PERSIST OVER THE GREAT LAKES REGION. THIS IS VERY WELL AGREED UPON BY THE 27.06Z/12Z GFS AND 27.00Z/12Z ECMWF. FOR MONDAY NIGHT INTO TUESDAY. CONDITIONS REMAIN FAVORABLE FOR A BAND OF SHOWERS TO FORM JUST NORTH OF THAT WARM FRONTAL BOUNDARY IN IOWA MONDAY EVENING...ASSOCIATED WITH DPVA FORCING AND 800-900MB FRONTOGENESIS. THIS BAND...AFFECTING LOCATIONS SOUTH OF I-90 MONDAY EVENING...SHOULD TRANSLATE NORTHWARD TO ALONG AND NORTH OF I-90 BY TUESDAY MORNING...WITH PRECIPITATION POSSIBLY TAILING OFF TO THE SOUTH. THEN WE GET INTO A COLD CONVEYOR BELT SCENARIO FOR TUESDAY AFTERNOON OVER NORTHWESTERN SECTIONS OF THE FORECAST AREA. OTHER SHOWERS SHOULD POP UP ELSEWHERE UNDER THE UPPER LOW DUE TO MID LEVEL COLD AIR. THERE COULD EVEN BE SOME THUNDER WITH THEM...BUT CONFIDENCE TOO LOW TO INCLUDE RIGHT NOW. FROM TUESDAY NIGHT THROUGH THURSDAY...THE FORECAST AREA PRETTY MUCH SITS IN A GRADUALLY WEAKENING COLD CONVEYOR BELT OF SHOWERS...WITH PERHAPS SOME DIURNAL ENHANCEMENT THAT COULD INCREASE COVERAGE. GIVEN HIGH CONFIDENCE OF PRECIPITATION AROUND...HAVE USED COVERAGE VERBIAGE. WITH PLENTY OF CLOUDS AND SHOWER ACTIVITY AROUND... COMBINED WITH 850MB TEMPS ONLY AROUND 0C PLUS OR MINUS 2 C...EXPECT CHILLY TEMPERATURES. CHANCES OF PRECIPITATION CONTINUE OFF AND ON FOR THURSDAY NIGHT RIGHT THROUGH SUNDAY AS SHORTWAVES DROP SOUTHEAST THROUGH THE GREAT LAKES TROUGHING. SOME SIGNAL THAT A SHORTWAVE TROUGH ON SUNDAY MIGHT BE MORE POTENT...SO CHANCES MAY NEED TO BE RAISED BEYOND THE CURRENT FORECAST OF A MODEL CONSENSUS. AS IT STANDS RIGHT NOW THE AIR IS NOT COLD ENOUGH FOR SNOW...BUT ITS NOT FAR OFF. 850MB STANDARDIZED ANOMALIES GENERALLY HOLD AROUND 1 STANDARD DEVIATION BELOW NORMAL...OR BETWEEN -4C AND 0C. NEEDLESS TO SAY...BELOW NORMAL TEMPERATURES CONTINUE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1110 PM CDT SUN APR 27 2014 CHALLENGING FORECAST AS THERE WILL BE PERIODS OF RA/TSRA...AND PIN POINTING WHERE THE BREAKS IN THE PCPN WILL BE IS PROBLEMATIC. IN ADDITION...WINDS WILL STAY STRONG AND GUSTY THROUGH TUESDAY AS TIGHT PRESSURE GRADIENT PERSISTS FOR MUCH OF THE UPPER MISSISSIPPI RIVER VALLEY - WITH THE RESPONSIBLE SFC LOW JUST TO THE SOUTH. WINDS WILL ALSO REMAIN STRONG JUST OFF THE SFC...50-60 KTS AROUND 2 KFT. LLWS WILL BE A FACTOR FOR KLSE THRU MONDAY AFTERNOON. BRIEF BREAK IN -SHRA FOR KRST/KLSE AS ONE BAND OF PCPN SHIFTED NORTH EARLIER THIS EVENING. ANOTHER BATCH OF SHRA/TS IS DEVELOPING ON THE NOSE OF AN INCREASING LOW LEVEL JET ACROSS CENTRAL/EASTERN IA. A MORE SIGNIFICANT SWATH OF THE WIDESPREAD SHRA/TS WILL RETURN NEAR 12Z MON AS AN UPPER LEVEL SHORTWAVE TROUGH SPINS NORTHEAST OUT OF THE SOUTHERN PLAINS. SHOULD MAKE FOR A SOGGY MORNING WITH MVFR VSBYS. ANTICIPATING CIGS IN THE IFR/MVFR RANGE BY THIS TIME. MODEL TRENDS WOULD FAVOR LIFTING THIS NORTH OF THE TAF SITES BY 18- 20Z...BRINGING ANOTHER MOSTLY DRY PERIOD FOR THE AFTERNOON. HOWEVER...ANOTHER ROUND OF PCPN APPEARS LIKELY AS SHRA/TS FIRE UP ALONG A WARM FRONT JUST TO THE SOUTH LATE AFTERNOON/EVENING...WHICH COULD PUSH NORTH. BOTTOM-LINE...AN EXTENDED PERIOD OF WET WEATHER WITH IFR/MVFR IMPLICATIONS FOR CIGS AND VSBYS. SOME THUNDER WILL BE POSSIBLE. WINDS ARE GOING TO STAY STRONG...MOSTLY EAST-NORTHEAST...AND LLWS WILL REMAIN A CONCERN AT KLSE INTO MON AFTERNOON. && .HYDROLOGY... ISSUED AT 313 PM CDT SUN APR 27 2014 PRECIPITATION FORECASTS REMAIN VERY UNCERTAIN FOR TONIGHT AS SHOWERS AND EMBEDDED THUNDERSTORMS OVER CENTRAL IOWA ARE MOVING FASTER THAN MOST MODELS. IN FACT...THE ONE MODEL THAT IS HANDLING THE PRECIPITATION WELL SUGGESTS WE COULD HAVE A BREAK OF 6 HOURS OF NO PRECIPITATION TONIGHT AFTER THEY PASS. ADDITIONALLY...THE CONVECTION TO THE SOUTH MAY END UP INGESTING MORE OF THE MOISTURE...LIMITING HEAVIER RAINFALL OVER THE FORECAST AREA. THIS SCENARIO IS LOOKING MORE LIKELY FOR TONIGHT. BETTER CONFIDENCE FOR MUCH OF THE AREA TO SEE ANYWHERE FROM 1/4 TO 1 INCH OF RAIN ON MONDAY...WITH ANOTHER 1/2 TO 1 INCH FROM MONDAY NIGHT INTO TUESDAY. IN SUMMARY...BASED ON RFC FORECAST DATA...CONFIDENCE WAS ONLY HIGH ENOUGH TO PUT A FLOOD WATCH ON THE TURKEY RIVER. SHOULD AROUND 1 INCH MATERIALIZE OVER THE BASIN THIS EVENING...THE WATCH WILL NEED TO BE UPGRADED. ELSEWHERE...HAVE CONTINUED THE ESF. THERE ARE SOME SIGNALS THAT HEAVIER QPF COULD FALL OVER WISCONSIN. SHOULD THIS MATERIALIZE...MORE FLOOD WATCHES FOR AREA RIVERS MAY BE REQUIRED. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR MNZ086-087-094-095. IA...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR IAZ008>010-018-019- 029. && $$ SHORT TERM...AJ LONG TERM....AJ AVIATION.....RIECK HYDROLOGY....AJ
AREA FORECAST DISCUSSION
NWS ALBANY NY
614 AM EDT MON APR 28 2014 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 615 AM EDT...PATCHY CLOUDS ARE PERSISTING ACROSS PORTIONS OF THE SOUTHERN GREENS...NORTHERN BERKSHIRES...AND NORTH/CENTRAL TACONICS...ALBEIT WITH LESS AREAL COVERAGE NOTED OVER THE LAST 2 HOURS. WE EXPECT THESE PATCHY CLOUDS TO CONTINUE TO ERODE OVER THE NEXT 1-3 HOURS...AS THEY MOVE SOUTH/SOUTHWEST. OTHERWISE...WE EXPECT GENERALLY MOSTLY SUNNY SKIES TO START THE DAY. HOWEVER...ADDITIONAL PATCHES OF CLOUDS ARE EXPECTED TO APPROACH FROM THE NORTHEAST ONCE AGAIN LATER TODAY...AFFECTING MAINLY SOUTHERN VT...NORTHERN MA...AND POSSIBLY THE UPPER HUDSON RIVER VALLEY. IN ADDITION...HIGHER CLOUDS WILL BEGIN TO APPROACH SOUTHERN AND WESTERN AREAS LATE THIS AFTERNOON. THE CLOUDS ACROSS NORTHEAST AREAS WILL BE THE RESULT OF SOME RESIDUAL MOISTURE ROTATING AROUND THE WESTERN PERIPHERY OF THE STORM SYSTEM WELL OFF THE NEW ENGLAND COAST. SOME OF THE HI-RES MODELS...INCLUDING THE HRRR AND THE OPERATIONAL NAM WRF HINT AT SOME LIGHT SHOWERS OR SPRINKLES POSSIBLY AFFECTING SOME HIGHER ELEVATIONS OF SOUTHERN VT BY EVENING. WILL INDICATE SOME SLIGHT CHC POPS FOR ISOLATED SHOWERS/SPRINKLES IN THIS REGION TO ACCOUNT FOR THIS REMOTE POSSIBILITY. DEEP MIXING TODAY TO AROUND 825 MB SHOULD ALLOW TEMPS TO REACH 60-65 IN MOST VALLEY AREAS...AND 55-60 ACROSS HIGHER ELEVATIONS TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... TONIGHT...A DEVELOPING EASTERLY LOW LEVEL FLOW WILL INITIALLY ENHANCE LOW LEVEL MOISTURE AND LOW CLOUD POTENTIAL ACROSS THE REGION LATER TONIGHT. THIS IS PARTICULARLY SUGGESTED BY THE RUC-13 AND NAM...AS WELL AS THE REGIONAL GEM. IN ADDITION...HIGH CLOUDS WILL CONTINUE TO INCREASE FROM THE SOUTH AND WEST. SO...WILL INDICATE PARTLY TO MOSTLY CLOUDY SKIES OVERNIGHT...WITH CLOUDS BECOMING MOST WIDESPREAD AFTER MIDNIGHT. WILL ALSO KEEP SLIGHT CHC POPS ACROSS PORTIONS OF SOUTHERN VT/NORTHWEST MA FOR SOME ISOLATED SHOWERS OR SPRINKLES...ESP THIS EVENING. WILL ALSO SIDE ON THE MILDER SIDE OF GUIDANCE...WITH GENERALLY 40-45 EXPECTED IN VALLEYS...AND 35-40 ACROSS HIGHER TERRAIN. TUESDAY...THE MID LEVEL RIDGE AXIS WILL SLOWLY MOVE EAST OF THE REGION DURING THE DAY...ALLOWING DEEPER MOISTURE TO BEGIN TO OVERSPREAD THE REGION FROM SOUTHWEST TO NORTHEAST. HOWEVER...IT APPEARS THAT FOR AREAS NEAR AND E OF THE HUDSON RIVER VALLEY...MOST OF THE MORNING HOURS SHOULD REMAIN DRY. WILL LIMIT POPS IN THESE AREAS FOR THE AFTERNOON HOURS...MAINLY IN THE CHC RANGE. TO THE W...WILL INDICATE MAINLY CHC POPS IN THE MORNING...AND BOOST TO LIKELY IN THE AFTERNOON. MOST OF THE RAIN SHOULD BE LIGHT...AS IT WILL ENCOUNTER INITIALLY DRY LOW/MID LEVEL AIR AND MID LEVEL SUBSIDENCE. TEMPS WILL BE SOMEWHAT TRICKY...AS ANY DELAY IN RAINFALL WILL ALLOW FOR WARMER MAX TEMPS. WILL SIDE ON THE WARMER SIDE OF GUIDANCE ACROSS THE UPPER HUDSON RIVER VALLEY AND SOUTHERN VT...WHERE THE RAIN SHOULD DEVELOP LATEST...AND THE POSSIBILITY FOR SOME THIN SPOTS ON THE OVERCAST WILL BE GREATEST. IN ADDITION...SOME ENHANCED DOWNSLOPING WITH THE INCREASING E/SE LOW LEVEL FLOW MAY HELP BOOST TEMPS FURTHER IN THESE AREAS...WHICH COULD REACH AROUND 60. ELSEWHERE...EXPECT MAX TEMPS TO REACH THE MID/UPPER 50S IN VALLEYS FROM ALBANY N...W AND NORTHEAST...AND 50-55 TO THE SOUTH AND WEST WHERE CLOUDS...RAIN...AND A COOLER MARINE MODIFIED AIR MASS SHOULD KEEP TEMPS COOLER. TUE NT-WED...ALTHOUGH IT APPEARS UNSETTLED DURING THIS PERIOD...IT LOOKS LIKE IT WON/T BE A COMPLETE WASHOUT...AS POCKETS OF SYNOPTIC LIFT MOVE ACROSS THE REGION. HOWEVER...THE GREATEST FORCING AND LOW LEVEL MOISTURE CONVERGENCE WILL REMAIN MAINLY SOUTH AND WEST OF THE REGION. SO...EXPECT SEVERAL ROUNDS OF SHOWERS AND/OR PERIODS OF RAINFALL...BUT THERE COULD EASILY BE SOME PERIODS WHERE ONLY SOME SPRINKLES OR PATCHY DRIZZLE OCCUR. AS A WEDGE OF DRIER AIR ADVECTS WESTWARD AROUND THE SOUTHERN PERIPHERY OF THE VERY STRONG HIGH TO OUR N...THERE IS ACTUALLY SOME POTENTIAL FOR SLEET TO MIX IN WITH ANY SHOWERS ACROSS HIGHER ELEVATIONS OF THE SOUTHERN ADIRONDACKS AND WESTERN NEW ENGLAND LATE TUE NT/EARLY WED AM. TEMPS WILL COOL INTO THE MID 30S TO LOWER 40S TUE NT...AND SHOULD ONLY REACH THE MID 40S TO LOWER 50S ON WED. IN FACT...SHOULD RAINFALL BE MORE PERSISTENT/STEADIER ON WED...EVEN COOLER MAX TEMPS COULD OCCUR...WITH MOST AREAS REMAINING BELOW 50. WINDS WILL ALSO INCREASE DURING THIS PERIOD AS THE LOW LEVEL PRESSURE GRADIENT TIGHTENS BETWEEN THE AFOREMENTIONED STRONG EASTERN CANADIAN HIGH...AND LOW PRESSURE APPROACHING FROM THE SOUTH AND WEST. EAST/SOUTHEAST WINDS WILL BECOME QUITE GUSTY AT TIMES...WITH SOME GUSTS OF 30-40 MPH POSSIBLE AT TIMES BY WED AFTN...PARTICULARLY ACROSS HIGHER ELEVATIONS OF THE TACONICS...SOUTHERN GREEN MTNS...AND NORTHERN BERKSHIRES...AS WELL AS ACROSS PORTIONS OF THE WESTERN ADIRONDACKS...MOHAWK VALLEY AND CATSKILLS. WED NT...THE BEST FORCING FROM THE COMBINATION OF ISENTROPIC LIFT...MOISTURE TRANSPORT AND LOW LEVEL JET DYNAMICS APPEARS TO BE DURING THIS PERIOD...LEADING TO WIDESPREAD SHOWERS OR A STEADY RAIN. SOME OF THE RAIN COULD BE HEAVY AT TIMES. IT WILL ALSO INITIALLY REMAIN WINDY...ESP THROUGH MIDNIGHT...WHERE SOME GUSTS INTO THE 35-45 MPH RANGE COULD OCCUR IN PORTIONS OF THE SOUTHERN GREENS AND NORTHERN BERKSHIRES. IT APPEARS THAT A WIDESPREAD 1-2 INCHES OF RAINFALL SHOULD OCCUR THROUGH DAYBREAK THU...WITH GREATER AMTS POSSIBLE ACROSS PORTIONS OF THE SE CATSKILLS...MID HUDSON VALLEY...AND NW CT. OVERNIGHT MINS SHOULD MAINLY BE IN THE UPPER 30S TO MID 40S. && .LONG TERM /THURSDAY THROUGH SUNDAY/... MORE UNSETTLED WEATHER IS EXPECTED TO LAST THROUGH THE UPCOMING WEEKEND. A VERTICALLY STACKED CUTOFF LOW WILL SIT AND SPIN OVER THE GREAT LAKES REGION AS PIECES OF ENERGY ROTATE AROUND IT ACROSS THE NORTHEAST. THIS WILL KEEP AT LEAST SCATTERED SHOWERS ACROSS OUR REGION THURSDAY THROUGH SUNDAY. WHILE IT WILL NOT BE RAINING ALL OF THE TIME THERE WILL BE PERIODS WHERE THE SHOWERS WILL BE MORE NUMEROUS WHICH WILL BE ON THURSDAY INTO FRIDAY. RAINFALL AMOUNTS ON THURSDAY THROUGH THURSDAY NIGHT WILL GENERALLY BE A THIRD OF AN INCH TO THREE QUARTERS OF AN INCH. EXPECT HIGHS ON THURSDAY TO RANGE FROM THE UPPER 50S AND LOWER 60S NORTHWEST TO LOWER 70S SOUTHEAST. LOWS THURSDAY NIGHT WILL BE IN THE UPPER 30S TO UPPER 40S AND HIGHS ON FRIDAY WILL BE IN THE MID 50S TO MID 60S. THE UPPER LEVEL TROUGH WILL EXPAND EASTWARD TOWARDS THE NORTHEAST FOR FRIDAY NIGHT INTO THE WEEKEND...AND START TO WEAKEN SOMEWHAT. AS A RESULT...WE WILL STILL SEE THE OPPORTUNITY FOR SHOWERS EACH DAY...MAINLY TIED TO DIURNAL HEATING AND TIMING OF WEAK VORTICITY MAXES ROTATING AROUND THE UPPER LEVEL LOW. EXPECT LOWS FRIDAY NIGHT TO RANGE FROM THE UPPER 30S NORTHWEST TO THE MID 40S SOUTHEAST WITH HIGHS ON SATURDAY IN THE MID 50S TO MID 60S. LOWS ON SATURDAY NIGHT ARE EXPECTED TO RANGE FROM THE MID 30S NORTHWEST TO THE MID 40S SOUTHEAST. THERE IS THE POSSIBILITY OF A LITTLE SNOW ACROSS THE SOUTHERN ADIRONDACKS LATE SATURDAY NIGHT. HIGHS ON SUNDAY WILL BE IN THE MID 50S TO LOWER 60S. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... VFR CONDITIONS ARE EXPECTED AT ALL THE TAF SITES THROUGH THE END OF THE TAF PERIOD ENDING AT 12Z TUESDAY. DURING TODAY...N-NW WINDS WILL BE ABOUT 5-10 KTS WITH SCT DIURNAL CU AT 4-6 KFT DEVELOPING DURING THE DAY. THERE WILL BE SOME PASSING CIRRUS CLOUDS AS WELL...BUT NO PRECIPITATION IS EXPECTED DUE TO HIGH PRESSURE NEARBY...AND VFR CONDITIONS WILL CONTINUE. THE CIRRUS CLOUDS WILL BECOME THICKER BY EVENING. OUTLOOK... TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA. WEDNESDAY: HIGH OPERATIONAL IMPACT.WINDY WITH GUSTS TO 31.0 LIKELY SHRA. WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. OCNL SHRA. THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA. THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. && .FIRE WEATHER... RH VALUES WILL FALL INTO THE 25-30 PERCENT RANGE THIS AFTERNOON... HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY...ALONG WITH A WETTING RAINFALL. THE RH WILL FALL INTO THE 25-35 PERCENT RANGE FOR MOST AREAS THIS AFTERNOON...LOWEST IN VALLEY AREAS. THE RH WILL THEN RECOVER TO 80-95 PERCENT TONIGHT...THEN FALL INTO THE 30-40 PERCENT RANGE FOR NORTHERN AREAS...AND 40-60 PERCENT RANGE FOR SOUTHERN AND WESTERN AREAS TUESDAY AFTERNOON. NORTHWEST WINDS AT 5-10 MPH THIS MORNING WILL BECOME NORTH TO NORTHEAST AND INCREASE TO 5-15 MPH THIS AFTERNOON...WITH SOME GUSTS POSSIBLY REACHING UP TO 20 MPH AT TIMES ACROSS PORTIONS OF THE UPPER HUDSON RIVER VALLEY. WINDS WILL VEER INTO THE EAST TONIGHT AT 5-15 MPH...THEN BECOME E TO SE ON TUESDAY AND INCREASE TO 10-20 MPH...WITH SOME GUSTS OF 20-30 MPH POSSIBLE IN THE AFTERNOON...ESP ACROSS PORTIONS OF SOUTHERN VT. A WETTING RAINFALL IS EXPECTED FOR LATE TUESDAY THROUGH THURSDAY. && .HYDROLOGY... NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED THROUGH EARLY IN THE WEEK. EXPECTING DRY WEATHER THROUGH TONIGHT AS HIGH PRESSURE DOMINATES. WET WEATHER WILL RETURN FOR MID WEEK AS A LARGE SLOW MOVING LOW PRESSURE SYSTEM TO OUR WEST IMPACTS THE REGION. THIS SYSTEM HAS THE POTENTIAL TO PRODUCE SOME HEAVY RAIN. HOWEVER THERE IS UNCERTAINTY IN THE POTENTIAL QPF AMOUNTS. AT THIS TIME...IT APPEARS THAT THE POTENTIAL FOR A WIDESPREAD 1-2 INCHES OF RAINFALL IS INCREASING...WITH SOME LOCALLY HIGHER AMTS POSSIBLE...PARTICULARLY ACROSS PORTIONS OF THE SE CATSKILLS...MID HUDSON VALLEY...AND NW CT. THIS SHOULD CAUSE SIGNIFICANT WITHIN BANK RISES ON MOST RIVERS...WITH THE POSSIBILITY OF SOME REACHING ACTION STAGE...ESPECIALLY IN THE HOUSATONIC BASIN...AND POSSIBLY ACROSS PORTIONS OF THE CATSKILLS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...KL/FRUGIS/IAA NEAR TERM...KL SHORT TERM...KL LONG TERM...FRUGIS/11 AVIATION...FRUGIS/11 FIRE WEATHER...KL/IAA HYDROLOGY...KL/IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
605 AM EDT MON APR 28 2014 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 445 AM EDT...PATCHY CLOUDS ACROSS PORTIONS OF THE WESTERN ADIRONDACKS...AND THE UPPER HUDSON VALLEY REGION ARE FINALLY BEGINNING TO ERODE. WE EXPECT THESE CLOUDS TO CONTINUE TO DECREASE IN AREAL COVERAGE THROUGH SUNRISE...ALLOWING TEMPS TO FALL SEVERAL MORE DEGREES IN MOST AREAS. AFTER DAYBREAK...WE EXPECT MOSTLY SUNNY SKIES TO START THE DAY. HOWEVER...ADDITIONAL PATCHES OF CLOUDS ARE EXPECTED TO APPROACH FROM THE NORTHEAST LATER TODAY...AFFECTING MAINLY SOUTHERN VT...NORTHERN MA...AND POSSIBLY THE UPPER HUDSON RIVER VALLEY. IN ADDITION...HIGHER CLOUDS WILL BEGIN TO APPROACH SOUTHERN AND WESTERN AREAS LATE THIS AFTERNOON. THE CLOUDS ACROSS NORTHEAST AREAS WILL BE THE RESULT OF SOME RESIDUAL MOISTURE ROTATING AROUND THE WESTERN PERIPHERY OF THE STORM SYSTEM WELL OFF THE NEW ENGLAND COAST. SOME OF THE HI-RES MODELS...INCLUDING THE HRRR AND THE OPERATIONAL NAM WRF HINT AT SOME LIGHT SHOWERS OR SPRINKLES POSSIBLY AFFECTING SOME HIGHER ELEVATIONS OF SOUTHERN VT BY EVENING. WILL INDICATE SOME SLIGHT CHC POPS FOR ISOLATED SHOWERS/SPRINKLES IN THIS REGION TO ACCOUNT FOR THIS REMOTE POSSIBILITY. DEEP MIXING TODAY TO AROUND 825 MB SHOULD ALLOW TEMPS TO REACH 60-65 IN MOST VALLEY AREAS...AND 55-60 ACROSS HIGHER ELEVATIONS TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... TONIGHT...A DEVELOPING EASTERLY LOW LEVEL FLOW WILL INITIALLY ENHANCE LOW LEVEL MOISTURE AND LOW CLOUD POTENTIAL ACROSS THE REGION LATER TONIGHT. THIS IS PARTICULARLY SUGGESTED BY THE RUC-13 AND NAM...AS WELL AS THE REGIONAL GEM. IN ADDITION...HIGH CLOUDS WILL CONTINUE TO INCREASE FROM THE SOUTH AND WEST. SO...WILL INDICATE PARTLY TO MOSTLY CLOUDY SKIES OVERNIGHT...WITH CLOUDS BECOMING MOST WIDESPREAD AFTER MIDNIGHT. WILL ALSO KEEP SLIGHT CHC POPS ACROSS PORTIONS OF SOUTHERN VT/NORTHWEST MA FOR SOME ISOLATED SHOWERS OR SPRINKLES...ESP THIS EVENING. WILL ALSO SIDE ON THE MILDER SIDE OF GUIDANCE...WITH GENERALLY 40-45 EXPECTED IN VALLEYS...AND 35-40 ACROSS HIGHER TERRAIN. TUESDAY...THE MID LEVEL RIDGE AXIS WILL SLOWLY MOVE EAST OF THE REGION DURING THE DAY...ALLOWING DEEPER MOISTURE TO BEGIN TO OVERSPREAD THE REGION FROM SOUTHWEST TO NORTHEAST. HOWEVER...IT APPEARS THAT FOR AREAS NEAR AND E OF THE HUDSON RIVER VALLEY...MOST OF THE MORNING HOURS SHOULD REMAIN DRY. WILL LIMIT POPS IN THESE AREAS FOR THE AFTERNOON HOURS...MAINLY IN THE CHC RANGE. TO THE W...WILL INDICATE MAINLY CHC POPS IN THE MORNING...AND BOOST TO LIKELY IN THE AFTERNOON. MOST OF THE RAIN SHOULD BE LIGHT...AS IT WILL ENCOUNTER INITIALLY DRY LOW/MID LEVEL AIR AND MID LEVEL SUBSIDENCE. TEMPS WILL BE SOMEWHAT TRICKY...AS ANY DELAY IN RAINFALL WILL ALLOW FOR WARMER MAX TEMPS. WILL SIDE ON THE WARMER SIDE OF GUIDANCE ACROSS THE UPPER HUDSON RIVER VALLEY AND SOUTHERN VT...WHERE THE RAIN SHOULD DEVELOP LATEST...AND THE POSSIBILITY FOR SOME THIN SPOTS ON THE OVERCAST WILL BE GREATEST. IN ADDITION...SOME ENHANCED DOWNSLOPING WITH THE INCREASING E/SE LOW LEVEL FLOW MAY HELP BOOST TEMPS FURTHER IN THESE AREAS...WHICH COULD REACH AROUND 60. ELSEWHERE...EXPECT MAX TEMPS TO REACH THE MID/UPPER 50S IN VALLEYS FROM ALBANY N...W AND NORTHEAST...AND 50-55 TO THE SOUTH AND WEST WHERE CLOUDS...RAIN...AND A COOLER MARINE MODIFIED AIR MASS SHOULD KEEP TEMPS COOLER. TUE NT-WED...ALTHOUGH IT APPEARS UNSETTLED DURING THIS PERIOD...IT LOOKS LIKE IT WON/T BE A COMPLETE WASHOUT...AS POCKETS OF SYNOPTIC LIFT MOVE ACROSS THE REGION. HOWEVER...THE GREATEST FORCING AND LOW LEVEL MOISTURE CONVERGENCE WILL REMAIN MAINLY SOUTH AND WEST OF THE REGION. SO...EXPECT SEVERAL ROUNDS OF SHOWERS AND/OR PERIODS OF RAINFALL...BUT THERE COULD EASILY BE SOME PERIODS WHERE ONLY SOME SPRINKLES OR PATCHY DRIZZLE OCCUR. AS A WEDGE OF DRIER AIR ADVECTS WESTWARD AROUND THE SOUTHERN PERIPHERY OF THE VERY STRONG HIGH TO OUR N...THERE IS ACTUALLY SOME POTENTIAL FOR SLEET TO MIX IN WITH ANY SHOWERS ACROSS HIGHER ELEVATIONS OF THE SOUTHERN ADIRONDACKS AND WESTERN NEW ENGLAND LATE TUE NT/EARLY WED AM. TEMPS WILL COOL INTO THE MID 30S TO LOWER 40S TUE NT...AND SHOULD ONLY REACH THE MID 40S TO LOWER 50S ON WED. IN FACT...SHOULD RAINFALL BE MORE PERSISTENT/STEADIER ON WED...EVEN COOLER MAX TEMPS COULD OCCUR...WITH MOST AREAS REMAINING BELOW 50. WINDS WILL ALSO INCREASE DURING THIS PERIOD AS THE LOW LEVEL PRESSURE GRADIENT TIGHTENS BETWEEN THE AFOREMENTIONED STRONG EASTERN CANADIAN HIGH...AND LOW PRESSURE APPROACHING FROM THE SOUTH AND WEST. EAST/SOUTHEAST WINDS WILL BECOME QUITE GUSTY AT TIMES...WITH SOME GUSTS OF 30-40 MPH POSSIBLE AT TIMES BY WED AFTN...PARTICULARLY ACROSS HIGHER ELEVATIONS OF THE TACONICS...SOUTHERN GREEN MTNS...AND NORTHERN BERKSHIRES...AS WELL AS ACROSS PORTIONS OF THE WESTERN ADIRONDACKS...MOHAWK VALLEY AND CATSKILLS. WED NT...THE BEST FORCING FROM THE COMBINATION OF ISENTROPIC LIFT...MOISTURE TRANSPORT AND LOW LEVEL JET DYNAMICS APPEARS TO BE DURING THIS PERIOD...LEADING TO WIDESPREAD SHOWERS OR A STEADY RAIN. SOME OF THE RAIN COULD BE HEAVY AT TIMES. IT WILL ALSO INITIALLY REMAIN WINDY...ESP THROUGH MIDNIGHT...WHERE SOME GUSTS INTO THE 35-45 MPH RANGE COULD OCCUR IN PORTIONS OF THE SOUTHERN GREENS AND NORTHERN BERKSHIRES. IT APPEARS THAT A WIDESPREAD 1-2 INCHES OF RAINFALL SHOULD OCCUR THROUGH DAYBREAK THU...WITH GREATER AMTS POSSIBLE ACROSS PORTIONS OF THE SE CATSKILLS...MID HUDSON VALLEY...AND NW CT. OVERNIGHT MINS SHOULD MAINLY BE IN THE UPPER 30S TO MID 40S. && .LONG TERM /THURSDAY THROUGH SUNDAY/... MORE UNSETTLED WEATHER IS EXPECTED TO LAST THROUGH THE UPCOMING WEEKEND. A VERTICALLY STACKED CUTOFF LOW WILL SIT AND SPIN OVER THE GREAT LAKES REGION AS PIECES OF ENERGY ROTATE AROUND IT ACROSS THE NORTHEAST. THIS WILL KEEP AT LEAST SCATTERED SHOWERS ACROSS OUR REGION THURSDAY THROUGH SUNDAY. WHILE IT WILL NOT BE RAINING ALL OF THE TIME THERE WILL BE PERIODS WHERE THE SHOWERS WILL BE MORE NUMEROUS WHICH WILL BE ON THURSDAY INTO FRIDAY. RAINFALL AMOUNTS ON THURSDAY THROUGH THURSDAY NIGHT WILL GENERALLY BE A THIRD OF AN INCH TO THREE QUARTERS OF AN INCH. EXPECT HIGHS ON THURSDAY TO RANGE FROM THE UPPER 50S AND LOWER 60S NORTHWEST TO LOWER 70S SOUTHEAST. LOWS THURSDAY NIGHT WILL BE IN THE UPPER 30S TO UPPER 40S AND HIGHS ON FRIDAY WILL BE IN THE MID 50S TO MID 60S. THE UPPER LEVEL TROUGH WILL EXPAND EASTWARD TOWARDS THE NORTHEAST FOR FRIDAY NIGHT INTO THE WEEKEND...AND START TO WEAKEN SOMEWHAT. AS A RESULT...WE WILL STILL SEE THE OPPORTUNITY FOR SHOWERS EACH DAY...MAINLY TIED TO DIURNAL HEATING AND TIMING OF WEAK VORTICITY MAXES ROTATING AROUND THE UPPER LEVEL LOW. EXPECT LOWS FRIDAY NIGHT TO RANGE FROM THE UPPER 30S NORTHWEST TO THE MID 40S SOUTHEAST WITH HIGHS ON SATURDAY IN THE MID 50S TO MID 60S. LOWS ON SATURDAY NIGHT ARE EXPECTED TO RANGE FROM THE MID 30S NORTHWEST TO THE MID 40S SOUTHEAST. THERE IS THE POSSIBILITY OF A LITTLE SNOW ACROSS THE SOUTHERN ADIRONDACKS LATE SATURDAY NIGHT. HIGHS ON SUNDAY WILL BE IN THE MID 50S TO LOWER 60S. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... VFR CONDITIONS ARE EXPECTED AT ALL THE TAF SITES THROUGH THE END OF THE TAF PERIOD ENDING AT 12Z TUESDAY. DURING TODAY...N-NW WINDS WILL BE ABOUT 5-10 KTS WITH SCT DIURNAL CU AT 4-6 KFT DEVELOPING DURING THE DAY. THERE WILL BE SOME PASSING CIRRUS CLOUDS AS WELL...BUT NO PRECIPITATION IS EXPECTED DUE TO HIGH PRESSURE NEARBY...AND VFR CONDITIONS WILL CONTINUE. THE CIRRUS CLOUDS WILL BECOME THICKER BY EVENING. OUTLOOK... TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA. WEDNESDAY: HIGH OPERATIONAL IMPACT.WINDY WITH GUSTS TO 31.0 LIKELY SHRA. WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. OCNL SHRA. THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA. THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. && .FIRE WEATHER... RH VALUES WILL FALL INTO THE 25-30 PERCENT RANGE THIS AFTERNOON... HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY...ALONG WITH A WETTING RAINFALL. THE RH WILL FALL INTO THE 25-35 PERCENT RANGE FOR MOST AREAS THIS AFTERNOON...LOWEST IN VALLEY AREAS. THE RH WILL THEN RECOVER TO 80-95 PERCENT TONIGHT...THEN FALL INTO THE 30-40 PERCENT RANGE FOR NORTHERN AREAS...AND 40-60 PERCENT RANGE FOR SOUTHERN AND WESTERN AREAS TUESDAY AFTERNOON. NORTHWEST WINDS AT 5-10 MPH THIS MORNING WILL BECOME NORTH TO NORTHEAST AND INCREASE TO 5-15 MPH THIS AFTERNOON...WITH SOME GUSTS POSSIBLY REACHING UP TO 20 MPH AT TIMES ACROSS PORTIONS OF THE UPPER HUDSON RIVER VALLEY. WINDS WILL VEER INTO THE EAST TONIGHT AT 5-15 MPH...THEN BECOME E TO SE ON TUESDAY AND INCREASE TO 10-20 MPH...WITH SOME GUSTS OF 20-30 MPH POSSIBLE IN THE AFTERNOON...ESP ACROSS PORTIONS OF SOUTHERN VT. A WETTING RAINFALL IS EXPECTED FOR LATE TUESDAY THROUGH THURSDAY. && .HYDROLOGY... NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED THROUGH EARLY IN THE WEEK. EXPECTING DRY WEATHER THROUGH TONIGHT AS HIGH PRESSURE DOMINATES. WET WEATHER WILL RETURN FOR MID WEEK AS A LARGE SLOW MOVING LOW PRESSURE SYSTEM TO OUR WEST IMPACTS THE REGION. THIS SYSTEM HAS THE POTENTIAL TO PRODUCE SOME HEAVY RAIN. HOWEVER THERE IS UNCERTAINTY IN THE POTENTIAL QPF AMOUNTS. AT THIS TIME...IT APPEARS THAT THE POTENTIAL FOR A WIDESPREAD 1-2 INCHES OF RAINFALL IS INCREASING...WITH SOME LOCALLY HIGHER AMTS POSSIBLE...PARTICULARLY ACROSS PORTIONS OF THE SE CATSKILLS...MID HUDSON VALLEY...AND NW CT. THIS SHOULD CAUSE SIGNIFICANT WITHIN BANK RISES ON MOST RIVERS...WITH THE POSSIBILITY OF SOME REACHING ACTION STAGE...ESPECIALLY IN THE HOUSATONIC BASIN...AND POSSIBLY ACROSS PORTIONS OF THE CATSKILLS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...IAA/FRUGIS/KL NEAR TERM...KL SHORT TERM...KL LONG TERM...FRUGIS/11 AVIATION...FRUGIS/11 FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
AREA FORECAST DISCUSSION
NWS MIAMI FL
1003 AM EDT MON APR 28 2014 .UPDATE... NO PLANS FOR CHANGES TO THE CURRENT FORECAST. THE 12Z SOUNDING FOR MFL SHOWS VERY STEEP MID LEVEL LAPSE RATES COMING IN AT 7C/KM WHICH IS ABOUT AS UNSTABLE AS IT GETS IN SOUTH FLORIDA. ALONG WITH WARM SURFACE FORECAST TEMPERATURES OF THE MID 90S ACROSS THE INTERIOR, THE ONLY MISSING INGREDIENT IS DEEP LAYER MOISTURE CONTENT WHICH IS SERIOUSLY LACKING. BUT WITH THIS KIND OF INSTABILITY, A FEW THUNDERSTORMS ARE DEFINITELY POSSIBLE ACROSS THE INTERIOR AND HRRR DOES SHOW SOME ISOLATED DEVELOPMENT FOR COLLIER NORTH TO GLADES COUNTIES. THE MARINE FORECAST IS ON TRACK ALSO SO NO CHANGES PLANNED THEIR EITHER. KOB && .PREV DISCUSSION... /ISSUED 721 AM EDT MON APR 28 2014/ AVIATION... LIGHT SOUTHEAST WINDS EARLY THIS MORNING WILL INCREASE TO 10-15 KNOTS WITH HIGHER GUSTS BY MID/LATE MORNING. GULF COAST SEA BREEZE IS FORECAST AT KAPF THIS AFTERNOON...WITH A SOUTH TO SOUTHWEST WIND. WINDS WILL DIMINISH THIS EVENING. LOW LEVEL MOISTURE WILL INCREASE LATE IN THE TAF PERIOD FROM THE SOUTHEAST...BRINGING AN INCREASE IN CLOUD COVER. PREV DISCUSSION... /ISSUED 300 AM EDT MON APR 28 2014/ .A FEW THUNDERSTORMS POSSIBLE WESTERN INTERIOR THIS AFTERNOON... SHORT TERM... HIGH PRESSURE OVER THE WESTERN ATLANTIC WATERS WILL REMAIN NEARLY STATIONARY TODAY INTO TUESDAY...AS LOW PRESSURE OVER THE CENTRAL UNITED STATES MOVES SLOWLY TO THE NORTHEAST TOWARDS THE GREAT LAKES. A MID TO UPPER LEVEL SHORTWAVE TROUGH OVER THE CENTRAL GULF OF MEXICO WILL ALSO MOVE EAST AND THROUGH THE FLORIDA PENINSULA THIS AFTERNOON BEFORE MOVING INTO THE WESTERN ATLANTIC WATERS TONIGHT. THIS WEATHER PATTERN WILL ALLOW FOR A SOUTHEAST WIND FLOW OVER SOUTH FLORIDA TODAY INTO TUESDAY ALONG WITH THE EAST AND WEST COAST SEA BREEZES DEVELOPING AND PUSHING INLAND EACH DAY. SO THERE WILL BE A SLIGHT CHANCE OF SHOWERS OVER THE INTERIOR AREAS EACH AFTERNOON WITH EVEN A SLIGHT CHANCE OF THUNDERSTORMS THIS AFTERNOON WEST OF LAKE OKEECHOBEE. THE LOW WILL CONTINUE TO MOVE SLOWLY NORTHEAST ACROSS THE GREAT LAKES FOR THE MIDDLE TO END OF THE WEEK...AS THE HIGH MOVES SLOWLY EAST FURTHER INTO THE ATLANTIC WATERS. THIS WILL ALLOW FOR A COLD FRONT ASSOCIATED WITH THE LOW TO MOVE SOUTHEAST INTO THE SOUTHEASTERN UNITED STATES FROM THE CENTRAL UNITED STATES. THIS IN TURN WILL ALLOW FOR THE WIND FLOW OVER SOUTH FLORIDA TO BECOME MORE SOUTHERLY...AND ALLOW FOR DEEPER TROPICAL MOISTURE TO WORK INTO THE AREA FROM THE SOUTH. THEREFORE...THE POPS WILL REMAIN IN THE ISOLATED TO SCATTERED RANGE OVER SOUTH FLORIDA WITH THE HIGHEST POPS AROUND THE LAKE OKEECHOBEE REGION. THERE COULD ALSO BE SOME THUNDERSTORMS FOR THE MIDDLE TO END OF THE WEEK OVER THE INTERIOR AND LAKE OKEECHOBEE REGION. LONG TERM... THE COLD FRONT WILL CONTINUE TO MOVE SOUTHWARD THROUGH SOUTH FLORIDA EARLY NEXT WEEKEND...BEFORE HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTH FOR LATE NEXT WEEKEND. THIS WILL KEEP THE TROPICAL MOISTURE IN PLACE OVER SOUTH FLORIDA EARLY NEXT WEEKEND...BEFORE DRIER AIR WORKS INTO SOUTH FLORIDA FOR LATE NEXT WEEKEND. SO WILL KEEP ISOLATED TO SCATTERED POPS OVER SOUTH FLORIDA FOR THE FIRST HALF OF NEXT WEEKEND...BEFORE GOING DRY FOR THE SECOND HALF OF NEXT WEEKEND. MARINE... THE WINDS WILL BE FROM THE SOUTHEAST AT 10 TO 15 KNOTS TODAY INTO TUESDAY...BEFORE SWINGING TO A MORE SOUTHERLY DIRECTION FOR THE MIDDLE TO END OF THE WEEK. THIS WILL KEEP THE SEAS AT BELOW 6 FEET IN BOTH THE ATLANTIC AND GULF WATERS OF SOUTH FLORIDA THROUGH THE WEEK. THERE COULD ALSO BE A NORTHEAST SWELL OF 2 TO 3 FEET THAT WILL BUILD INTO SOUTH FLORIDA ATLANTIC WATERS LATE THIS WEEK FROM THE NORTH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 77 88 77 / 10 10 10 10 FORT LAUDERDALE 87 79 87 79 / 10 10 10 10 MIAMI 88 78 88 78 / 10 10 10 10 NAPLES 89 74 89 74 / 10 10 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
620 AM EDT MON APR 28 2014 .SYNOPSIS... ATLANTIC HIGH PRESSURE EARLY THIS WEEK WILL DIMINISH AHEAD OF A SLOW MOVING COLD FRONT...BRINGING UNSETTLED WEATHER FOR THE MIDDLE OF THE WEEK. THE FRONT WILL THEN LINGER JUST OFFSHORE THROUGH LATE IN THE WEEK...BEFORE HIGH PRESSURE BUILDS INTO THE REGION BY NEXT SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 28/09Z RAP SOUNDINGS DEPICTED AN EVEN WEAKER CAP ACROSS INTERIOR SOUTHEAST SOUTH CAROLINA AHEAD OF THE SEA BREEZE. HAVE OPTED TO INCLUDE A SLIGHT CHANCE OF SHOWERS/TSTMS FOR A FEW HOURS THIS AFTERNOON GIVEN THIS TREND. NO OTHER CHANGES WERE MADE TO THE GOING FORECAST. A CLASSIC OMEGA BLOCKING PATTERN WILL REMAIN IN TACT ACROSS THE EASTERN HALF OF THE U.S. TODAY WITH A STRONG AND QUITE PRONOUNCED UPPER RIDGE CENTERED DIRECTLY OVER THE SOUTHEAST STATES. AT THE SURFACE...THE AREA IS LOCATED ALONG THE WESTERN FLANKS OF ATLANTIC HIGH PRESSURE...WHICH IS HELPING TO KEEP ELEVATED DEWPOINTS IN THE 60S IN PLACE. TODAY HAS THE POTENTIAL TO BE THE WARMEST DAY SO FAR THIS YEAR WITH VARIOUS GUIDANCE TRENDS AND LOW-LEVEL THICKNESSES SCHEMES SUPPORTING HIGHS IN THE UPPER 80S TO LOWER 90S AWAY FROM THE BEACHES. THE DEGREE OF WARMTH WILL BE HEAVILY INFLUENCED BY THE AMOUNT OF CLOUD COVER TODAY. THIN CIRRIFORM CLOUDS TRAVERSING THE FORECAST AREA THIS MORNING WILL GRADUALLY SHIFT NORTH WITH BOTH THE CMC AND NAM SIMULATED CLOUD PRODUCTS SHOWING SKIES CLEARING LATER THIS MORNING. THE RESULTING STRONG INSOLATION AND 60+ DEGREE DEWPOINTS WILL PROMOTE A SHALLOW CUMULUS FIELD FORMING AHEAD OF THE SEA BREEZE BY THIS AFTERNOON WITH ANOTHER BATCH OF MID/HIGH-LEVEL CLOUDS STREAMING BACK IN FROM THE WEST CLOSER TO SUNSET. THE RESULTANT SEA BREEZE CIRCULATION IS EXPECTED TO REACH THE I-95 CORRIDOR BY MID-AFTERNOON AND FAR INLAND AREAS LATE. RAP/NAM SOUNDINGS SHOW A PRONOUNCED SUBSIDENCE INVERSION ASSOCIATED WITH THE MID/UPPER-LEVEL RIDGE AXIS. THIS INVERSION IS FORECAST TO HOLD FOR MUCH OF THE DAY...DESPITE TEMPERATURES WARMING TO NEAR 90 DEGREES. THERE ARE SOME SIGNALS THAT THE CAP MAY WEAKEN JUST ENOUGH ACROSS THE NORTHERN HALF OF THE FORECAST AREA TO SUPPORT AN ISOLATED SHOWER/TSTM ALONG THE BROAD LOW-LEVEL CONVERGENCE ZONE ASSOCIATED WITH THE THERMALLY DIRECT SEA BREEZE CIRCULATION...BUT MOST OF THE HIGHER RESOLUTION MODEL RUNS SHOW LITTLE...IF ANY...QPF. SINCE THE MODELS HAVE BEEN TOO AGGRESSIVE WITH CONVECTIVE DEVELOPMENT WITHIN THIS SUBSIDENT REGIME OVER THE PAST FEW DAYS...POPS WILL BE HELD BELOW MENTIONABLE THRESHOLDS FOR THE AFTERNOON HOURS. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... TONIGHT...THE RESULTANT SEA BREEZE WILL CLEAR THE FAR WESTERN AREAS SHORTLY AFTER SUNSET AS THE AREA REMAINS ALONG THE WESTERN FLANKS OF ATLANTIC HIGH PRESSURE. LOW-LEVEL WIND FIELDS ARE FORECAST TO INCREASE OVERNIGHT AS NOCTURNAL JETTING INTENSIFIES AHEAD OF AN APPROACHING COLD FRONT. THIS SHOULD KEEP THE ATMOSPHERE FAIRLY WELL MIXED OVERNIGHT AND KEEPING THE BOUNDARY LAYER FROM FULLY DECOUPLING. THIS WILL RESULT IN A WARM AND FAIRLY HUMID NIGHT WITH LOWS RANGING FROM THE MID 60S WELL INLAND TO AROUND 70 ACROSS THE COASTAL COUNTIES. IT WILL BE A DRY NIGHT WITH ANY SHOWER ACTIVITY THAT DEVELOPS LIKELY REMAINING WELL TO THE WEST THROUGH SUNRISE AND POSSIBLY OVER THE WESTERN WALL OF THE GULF STREAM. TUESDAY...THE AXIS OF THE UPPER RIDGE WILL SHIFT INTO THE NEARBY ATLANTIC WATERS DURING THE MORNING HOURS...AS A ROBUST STACKED LOW SYSTEM BEGINS TO BREAK THE OMEGA BLOCKING PATTERN AND MOVE NORTH/NORTHEAST ACROSS THE MID MISSISSIPPI VALLEY. THE SOUTHEAST STATES WILL BECOME LOCATED BETWEEN A WARM FRONT LIFTING WELL NORTH OF THE AREA AND THE COLD FRONT TRAILING FROM THE LOW SYSTEM FAR UPSTREAM. SOLID SOUTHERLY FLOW WILL CONTINUE TO SUPPORT INCREASING LOW LEVEL MOISTURE AND WARM TEMPERATURES PEAKING FAR ABOVE SEASONAL NORMALS. AS A RESULT...DECENT INSTABILITY WILL DEVELOP TUESDAY AFTERNOON...WHILE MID LEVEL LAPSE RATES INCREASE UP TO 7 C/KM. A BAND OF WEAK SHORTWAVE ENERGY RIDING ALONG THE PERIPHERY OF THE RETREATING UPPER RIDGE COULD PROVIDE SOME FORCING. YET WITH STRONGEST DYNAMICS STILL WEST OF THE AREA...BEST CONVECTIVE COVERAGE WILL BE ACROSS INLAND AREAS...AS THUNDERSTORM DEVELOPMENT AND INTENSIFICATION WILL BE MAINLY DRIVEN BY SEABREEZE AND BOUNDARY INTERACTIONS. WILL STILL NEED TO MONITOR FOR THE POSSIBILITY THAT AN ISOLATED THUNDERSTORM COULD BECOME ORGANIZED OR SEVERE WITHIN LOW TO MODERATE INSTABILITY AND SOME INCREASE IN SHEAR PROFILES...ESPECIALLY IF ANY ONGOING UPSTREAM CONVECTION CAN SLIP INTO THE FAR WESTERN PERIPHERY LATE IN THE DAY. CONSIDERING THE STEADILY INTENSIFYING UPPER LEVEL SUPPORT AHEAD OF THE IMPRESSIVE LOW SYSTEM TO THE WEST...WILL MAINTAIN SLIGHT TO LOW CHANCE POPS ACROSS THE FORECAST AREA THROUGH TUESDAY NIGHT. WEDNESDAY...THE COLD FRONT TRAILING FROM THE MASSIVE LOW SYSTEM NOW LOCATED ACROSS THE OHIO VALLEY/GREAT LAKES REGION WILL MAKE SLOW YET GRADUAL PROGRESS EASTWARD. THE FORECAST AREA WILL REMAIN IN THE WARM SECTOR OF THE APPROACHING SYSTEM...WITH THE SLOW- MOVING FRONT JUST ALONG THE WESTERN PERIPHERY OF THE AREA BY DAYBREAK THURSDAY. DESPITE THICK CLOUDS REDUCING INSOLATION AS WELL AS INCREASING SHOWER/THUNDERSTORM COVERAGE...TEMPERATURES WILL STILL RISE INTO THE LOW TO MID 80S WITHIN WARM SOUTHERLY FLOW AND SOME PRE-FRONTAL COMPRESSION EFFECTS. AS BOTH LOW LEVEL AND UPPER LEVEL JETTING INCREASE ACROSS THE SOUTHEAST AND MID- ATLANTIC STATES DOWNSTREAM OF THE UPPER TROUGH AXIS...SHEAR WILL ALSO INCREASE ACROSS THE AREA AT THE SAME TIME THAT MID LEVEL LAPSE RATES REACH 7 TO 7.5 C/KM. THUNDERSTORM COVERAGE WILL BE HIGHEST LATE WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...WITH RAIN CHANCES UP TO 50 PERCENT DURING THIS TIME FRAME. CONSIDERING SUCH A STRONGLY DYNAMIC SYSTEM...THERE IS STILL A POTENTIAL FOR ISOLATED THUNDERSTORMS TO BECOME SEVERE...ESPECIALLY WHERE BOUNDARY INTERACTIONS OCCUR AND ENHANCE UPDRAFT STRENGTH. THE MAIN LIMITING FACTOR WOULD BE SUPPRESSED INSTABILITY IN AREAS OF THICK CLOUD COVER AND HEAVY RAIN. THURSDAY...THE COLD FRONT WILL SLOWLY PROGRESS THROUGH THE FORECAST AREA AND INTO THE COASTAL WATERS THROUGH THE DAY. IT APPEARS THAT THE BULK OF THE CONVECTION WILL HAVE OCCURRED AHEAD OF THE ACTUAL FRONT...AND THUS RAIN COVERAGE WILL BE DOWN TO SCATTERED OR EVEN ISOLATED AS THE FRONT MOVES THROUGH REGION. PROGRESSION OF THE FEATURE APPEARS TO SLOW EVEN FURTHER LATE IN THE DAY...ALLOWING CONVERGENCE AND DEEP MOISTURE ALONG THE FRONTAL ZONE TO LINGER ALONG COASTAL AREAS THROUGH THE NIGHTTIME HOURS. HAVE THUS MAINTAINED SLIGHT TO LOW CHANCE POPS INTO FRIDAY MORNING. HIGH TEMPERATURES WILL BE SEVERAL DEGREES COOLER THAN SEEN DURING THE EARLY TO MID WEEK PERIOD...PEAKING IN THE LOW 80S AWAY FROM THE LOCALLY COOLER COASTLINE. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... MEDIUM RANGE NUMERICAL MODEL SOLUTIONS ARE COMING INTO BETTER AGREEMENT REGARDING THE POTENTIAL FOR THE OFFSHORE FRONT TO LINGER NEARBY THROUGH THURSDAY NIGHT. SHORTWAVE ENERGY WILL SWING ACROSS THE GULF COAST STATES INTO THE SOUTHEAST REGION ALONG THE BASE OF THE LONGWAVE UPPER TROUGH...PROVIDING SUFFICIENT ENERGY TO DEVELOP A WEAK WAVE OF LOW PRESSURE ALONG THE MEANDERING BOUNDARY. AS THIS OCCURS...CONVECTION WILL ONCE AGAIN SPREAD INLAND ON FRIDAY...BEFORE THE FRONT IS PULLED OFFSHORE WITH THE SURFACE WAVE FRIDAY NIGHT. SURFACE HIGH PRESSURE WILL FINALLY BE ABLE TO BUILD INTO THE REGION...WHILE THE EARLIER HIGHLY AMPLIFIED PATTERN ALOFT DAMPENS INTO NEARLY ZONAL FLOW BY EARLY NEXT WEEK. RAIN CHANCES PEAKING IN THE 40 PERCENT RANGE FRIDAY AFTERNOON WILL THEN STEADILY TREND DOWNWARD FRIDAY NIGHT INTO SATURDAY...WITH POPS FALLING BELOW 15 PERCENT SATURDAY NIGHT INTO MONDAY. HIGH TEMPERATURES WILL BE COOLEST ON FRIDAY...PEAKING ONLY IN THE LOW TO MID 70S...BEFORE TRENDING BACK UP TOWARD SEASONAL NORMALS IN THE UPPER 70S FOR THE REMAINDER OF THE PERIOD. LOW TEMPERATURES WILL FALL INTO THE LOW TO MID 50S FRIDAY AND SATURDAY NIGHTS...THEN ALSO MODERATE A FEW DEGREES FOR THE NIGHTTIME HOURS EARLY NEXT WEEK. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... VFR. EXTENDED AVIATION OUTLOOK...THE MOST LIKELY PERIOD WITH FLIGHT RESTRICTIONS IS WEDNESDAY INTO THURSDAY DUE TO SHRA/TSRA ASSOCIATED WITH THE NEXT COLD FRONT. BREEZY CONDITIONS BOTH TUESDAY AND WEDNESDAY AT THE TERMINALS. && .MARINE... TODAY...NO CONCERNS. SOUTHERLY WIND REGIME WILL PERSIST WITH WINDS 10-15 KT AND SEAS 2-3 FT WITH AN UNDERLYING 1-2 FT 8-9 SECOND GROUND SWELL. TONIGHT...WINDS WILL INCREASE IN RESPONSE TO NOCTURNAL JETTING. MIXING PROFILES WILL NOT BE IDEAL IN THE SOUTHERLY WIND REGIME SO WINDS WERE CAPPED AT 15-20 KT. SEAS WILL BUILD 3-4 FT NEARSHORE WATERS AND 4-5 FT OFFSHORE WATERS. TUESDAY AND WEDNESDAY...THE PRESSURE GRADIENT WILL TIGHTEN AHEAD OF A SLOW-MOVING COLD FRONT INTO THE MID WEEK PERIOD. EXPECT SOUTHERLY FLOW TO INCREASE AND SEAS TO BUILD ACCORDINGLY. MIXING WILL BE SOMEWHAT LIMITED WITHIN THE WARM ADVECTION REGIME...HOWEVER ENHANCEMENTS FROM THE AFTERNOON SEA BREEZE AND NOCTURNAL LOW LEVEL JETTING COULD SUPPORT MARGINAL SMALL CRAFT ADVISORY CONDITIONS AT TIMES...ESPECIALLY IN CHARLESTON HARBOR AND THE OUTER GEORGIA WATERS. THURSDAY THROUGH FRIDAY...THE COLD FRONT WILL STRUGGLE TO SHIFT THROUGH THE WATERS...LIKELY STALLING OVER OR NEAR THE MARINE AREA LATE IN THE WEEK. ANY LINGERING ADVISORY-LEVEL WINDS OR SEAS WILL LIKELY WILL END BY THURSDAY MORNING AND REMAIN BELOW CRITERIA FRIDAY. MARINERS ARE CAUTIONED THAT SOME STRONG OR SEVERE STORMS COULD IMPACT THE COASTAL WATERS WEDNESDAY AND THURSDAY. REMEMBER TO MAINTAIN A WEATHER WATCH AND MONITOR NOAA WEATHER RADIO...ALL HAZARDS. RIP CURRENTS...MID TO HIGH-END LOW RISK FOR TODAY GIVEN STEADY ONSHORE WINDS AND A 8 TO OCCASIONAL 9 SECOND 1-2 FT GROUND SWELL. AN ENHANCED RISK FOR RIP CURRENTS IS POSSIBLE TUESDAY AND PERHAPS WEDNESDAY GIVEN THE NEW MOON AND STRONGER ONSHORE WINDS. && .TIDES/COASTAL FLOODING... GIVEN INFLUENCES FROM THE UPCOMING NEW MOON AND AN INCREASING AND PERSISTENT ONSHORE WINDS...TIDAL DEPARTURES MAY BE ENOUGH TO RESULT IN SHALLOW COASTAL FLOODING WITH THE EVENING HIGH TIDES THROUGH EARLY THIS WEEK...MAINLY ACROSS SOUTH COASTAL SOUTH CAROLINA. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ ST
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1035 AM EDT MON APR 28 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 304 AM EDT MON APR 28 2014 A LARGE AND SLOW MOVING LOW PRESSURE SYSTEM IS EXPECTED TO GRADUALLY MOVE FROM THE PLAINS INTO THE GREAT LAKES REGION BY LATE THIS WEEK. THIS LOW WILL KEEP THE WEATHER UNSETTLED FOR MOST OF THIS UPCOMING WEEK. && .NEAR TERM /TODAY AND TONIGHT/... ISSUED AT 950 AM EDT MON APR 28 2014 RADAR MOSAIC AT 930 AM SHOWS LARGE AREA OF RAIN OVER THE NORTHEAST HALF OR SO OF THE AREA MOVING OFF TO THE NORTHEAST WITH MORE RAIN OVER SOUTHERN ILLINOIS/WESTERN KENTUCKY MOVING NORTHEAST AS WELL TOWARD SOUTHERN INDIANA. VISIBLE SATELLITE SHOWS A CLEAR SLOT OVER CENTRAL ILLINOIS...BUT A LOOP OF THIS FEATURE SHOWS IT ROTATING MAINLY TO THE NORTH AND THUS COULD STAY OVER ILLINOIS AND MOVE INTO NORTHERN INDIANA BUT KEEP CENTRAL INDIANA IN MOSTLY TO COMPLETELY CLOUDY SKIES FOR THE DAY. FOR THE UPDATE ADDED SOME TIMING FOR POPS FOR THE REST OF THE MORNING/EARLY AFTERNOON WITH A BREAK IN PRECIP MOVING IN FROM THE EAST AND LASTING FOR THE NEXT FEW HOURS. KEPT HIGH CHANCE TO LIKELY POPS GOING IN THE SOUTH FOR THE AFOREMENTIONED ECHOES MOVING NORTHEAST FROM S IL/W KY. HI RES MODELS ARE SHOWING DIFFERENT SCENARIOS FOR THE AFTERNOON/EARLY EVENING AND THIS IS CONTRIBUTING TO HIGH UNCERTAINTY FOR THAT PERIOD. HRRR SHOWS ALL DEVELOPMENT OCCURRING TO THE NORTH OF THE AREA WITH NOTHING FURTHER UNTIL THE COLD FRONT ARRIVES LATER TONIGHT. RAP CONTINUES TO DEVELOP SCATTERED CONVECTION THIS AFTERNOON. HESITANT TO BUY INTO HRRR HOOK LINE AND SINKER WITH SUCH A DYNAMIC SYSTEM SO WENT WITH LOW CHANCE POPS ACROSS THE AREA LATE MORNING/EARLY AFTERNOON INCREASING TO LIKELY ACROSS THE AREA AFTER 20Z. AGAIN WITH MODEL VARIABILITY...NOT READY TO CHANGE SEVERE OUTLOOK OR TIMING FROM PREVIOUS FORECAST. PREVIOUS DISCUSSION FOLLOWS... ADDITIONAL DEVELOPMENT LATER TODAY A LITTLE MORE QUESTIONABLE...AS SOME OF THE MODEL DATA SUGGEST MORE SHOWER/THUNDERSTORMS DEVELOPMENT THIS AFTERNOON ALONG THE EDGE OF THE APPROACHING DRY SLOT/STEEPER LAPSE RATES...WHILE OTHERS SUGGEST DEVELOPMENT MAY HOLD OFF UNTIL TOWARDS/AFTER 290000Z WHEN SURFACE COLD FRONT/OCCLUSION MOVES THROUGH. AT THIS POINT...WILL KEEP RATHER HIGH POPS GOING THROUGH ABOUT MIDNIGHT TONIGHT...WITH THE HIGHEST POPS THROUGH ABOUT MIDDAY TODAY. SEVERE POTENTIAL TODAY AND TONIGHT A LITTLE LESS CLEAR. MODEL DATA STILL SUGGEST ADEQUATE DEEP SHEAR/LAPSE RATES BY LATER THIS AFTERNOON AND TONIGHT FOR SEVERE...ALTHOUGH THE DEEP SHEAR LOOKS A LITTLE WEAKER TODAY THAN IT DID YESTERDAY. ALSO...LARGE AMOUNTS OF CONVECTION DEVELOPING SOUTH OF THE OHIO RIVER IS GETTING CLOSE TO CUTTING OFF THE FLOW OF DEEPER MOISTURE/MORE UNSTABLE AIR INTO THE AREA. APPEARS THE BEST CHANCE FOR SEVERE WILL BE FROM THE MID AFTERNOON HOURS UNTIL ABOUT MIDNIGHT TONIGHT...EMANATING EITHER FROM DEVELOPMENT ALONG THE EDGE OF DRY SLOT LATER THIS AFTERNOON OR WITH ACTIVITY TONIGHT NEAR THE SURFACE FRONT. TODAY/S GFS MOS SEEMS TO MAY LOST ITS WARM BIAS OF THE PAST COUPLE OF DAYS...AND THE NUMBERS FOR TODAY AND TONIGHT LOOK MORE REASONABLE. ONLY MINOR ADJUSTMENTS PLANNED. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... ISSUED AT 304 AM EDT MON APR 28 2014 MODEL DATA SUGGEST A LARGE UPPER LOW WILL GRADUALLY SHIFT NORTHEAST FROM THE PLAINS INTO THE MIDWEST DURING THIS PERIOD...KEEPING THE WEATHER UNSETTLED. BY TUESDAY...MODEL DATA SUGGEST DRIER AIR WRAPPING AROUND THE UPPER LOW WILL MOVE INTO THE AREA. LAPSE RATES ARE QUITE STEEP ON TUESDAY...HOWEVER BETTER SHEAR PUSHES OFF TO THE EAST WITH TIME. WILL GO WITH CHANCE POPS FOR SHOWERS/THUNDERSTORMS ON TUESDAY AND TUESDAY NIGHT AS A SURFACE TROUGH MOVES THROUGH...WHICH MAY SERVE AS FOCUS FOR CONVECTION. THE PRESENCE OF THE STEEP LAPSE RATES ON TUESDAY SUGGEST HAIL POTENTIAL WITH ANY STRONGER CELLS THAT MAY DEVELOP. WILL KEEP SOME CHANCE POPS GOING INTO WEDNESDAY AND WEDNESDAY NIGHT AS FILLING UPPER LOW MOVES INTO THE GREAT LAKES. BASED OFF ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS HIGHS FOR TUESDAY AND WEDNESDAY LOOK A LITTLE WARM. WILL CUT A FEW DEGREES OFF THE GUIDANCE HIGHS ON BOTH DAYS. LOWS LOOK REASONABLE. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 338 AM EDT MON APR 28 2014 A LARGE UPPER LOW OVER THE GREAT LAKES THURSDAY WILL LIFT NORTH INTO SOUTHERN CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY. A CYCLONIC UPPER FLOW FROM THIS UPPER LOW WILL KEEP MOSTLY CLOUDY SKIES AND CHANCES OF SHOWERS THURSDAY INTO SATURDAY. A WEAK COLD FRONT WILL MOVE ACROSS OUR REGION EARLY SATURDAY FOLLOWED BY A HIGH PRESSURE RIDGE SATURDAY NIGHT. SEVERAL MODELS INDICATE ANOTHER CHANCE OF PRECIPITATION MAY BEGIN SUNDAY AS ANOTHER SYSTEM APPROACHES. ADDED ISOLATED THUNDER TO SUNDAY AS MODELS INDICATE MU CAPES OF UP TO 500 J/KG. OTHERWISE...ANY PRECIPITATION WILL BE ONLY BE SCATTERED LIGHT SHOWERS OR SPRINKLES. TEMPERATURES WILL REMAIN QUITE COOL THURSDAY THROUGH SATURDAY AND THEN MODERATE A LITTLE SUNDAY. ONLY MADE MINOR TWEAKS TO ALL BLEND TEMPERATURES MAINLY TO RAISE MINS SLIGHTLY THURSDAY AND FRIDAY NIGHT AS THERE WILL BE LOTS OF CLOUDS. && .AVIATION /DISCUSSION FOR 281200Z TAF ISSUANCE/... ISSUED AT 1032 AM EDT MON APR 28 2014 1430Z UPDATE...FEW UPDATES TO THE TAFS. REMOVED -SHRA AND TS FOR THE NEXT SEVERAL HOURS AND LOWERED THE FLIGHT CATEGORY TO IFR FOR THE NEXT SEVERAL HOURS AT OUTLYING SITES SUCH AS KHUF AND KBMG BASED ON OBSERVATIONS. KIND AND KLAF APPEAR TO BE REMAINING AT MFVR AND GETTING DOUBTFUL THEY WILL REACH VFR BEFORE NEXT SYSTEM MOVES THROUGH LATER TODAY. PREVIOUS DISC FOLLOWS. NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS EARLY THIS MORNING. THERE COULD BE ANOTHER PERIOD OF NUMEROUS SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON OR EARLY TONIGHT PER MODELS. OTHERWISE...WILL MENTION VCSH REST OF THE PERIOD THROUGH MIDNIGHT TONIGHT. STRONG LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE SLOWLY NORTHEAST INTO THE UPPER MIDWEST. SHOWERS AND A FEW THUNDERSTORMS THIS MORNING MAY IN MVFR CONDITIONS AT TIME. MOST OF THE SHOWERS SHOULD MOVE OUT BY 15Z...BUT AREAS OF MVFR CEILINGS MAY PERSIST INTO MIDDAY. SEVERAL MODELS INDICATE THERE COULD BE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. WILL ADD ANOTHER PERIOD OF VCTS AS A RESULT FROM 20Z TO ABOUT 05Z. NAM REFLECTIVITY MODEL MOST OF THIS WILL MOVE OUT AFTER MIDNIGHT AS A DRY SLOT PUSHES INTO OUR AREA. COULD BE ANOTHER PERIOD OF MVFR CEILINGS TONIGHT. EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JAS NEAR TERM...JAS/CP SHORT TERM...JAS LONG TERM....JH AVIATION...SMF/JH VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
950 AM EDT MON APR 28 2014 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 304 AM EDT MON APR 28 2014 A LARGE AND SLOW MOVING LOW PRESSURE SYSTEM IS EXPECTED TO GRADUALLY MOVE FROM THE PLAINS INTO THE GREAT LAKES REGION BY LATE THIS WEEK. THIS LOW WILL KEEP THE WEATHER UNSETTLED FOR MOST OF THIS UPCOMING WEEK. && .NEAR TERM /TODAY AND TONIGHT/... ISSUED AT 950 AM EDT MON APR 28 2014 RADAR MOSAIC AT 930 AM SHOWS LARGE AREA OF RAIN OVER THE NORTHEAST HALF OR SO OF THE AREA MOVING OFF TO THE NORTHEAST WITH MORE RAIN OVER SOUTHERN ILLINOIS/WESTERN KENTUCKY MOVING NORTHEAST AS WELL TOWARD SOUTHERN INDIANA. VISIBLE SATELLITE SHOWS A CLEAR SLOT OVER CENTRAL ILLINOIS...BUT A LOOP OF THIS FEATURE SHOWS IT ROTATING MAINLY TO THE NORTH AND THUS COULD STAY OVER ILLINOIS AND MOVE INTO NORTHERN INDIANA BUT KEEP CENTRAL INDIANA IN MOSTLY TO COMPLETELY CLOUDY SKIES FOR THE DAY. FOR THE UPDATE ADDED SOME TIMING FOR POPS FOR THE REST OF THE MORNING/EARLY AFTERNOON WITH A BREAK IN PRECIP MOVING IN FROM THE EAST AND LASTING FOR THE NEXT FEW HOURS. KEPT HIGH CHANCE TO LIKELY POPS GOING IN THE SOUTH FOR THE AFOREMENTIONED ECHOES MOVING NORTHEAST FROM S IL/W KY. HI RES MODELS ARE SHOWING DIFFERENT SCENARIOS FOR THE AFTERNOON/EARLY EVENING AND THIS IS CONTRIBUTING TO HIGH UNCERTAINTY FOR THAT PERIOD. HRRR SHOWS ALL DEVELOPMENT OCCURRING TO THE NORTH OF THE AREA WITH NOTHING FURTHER UNTIL THE COLD FRONT ARRIVES LATER TONIGHT. RAP CONTINUES TO DEVELOP SCATTERED CONVECTION THIS AFTERNOON. HESITANT TO BUY INTO HRRR HOOK LINE AND SINKER WITH SUCH A DYNAMIC SYSTEM SO WENT WITH LOW CHANCE POPS ACROSS THE AREA LATE MORNING/EARLY AFTERNOON INCREASING TO LIKELY ACROSS THE AREA AFTER 20Z. AGAIN WITH MODEL VARIABILITY...NOT READY TO CHANGE SEVERE OUTLOOK OR TIMING FROM PREVIOUS FORECAST. PREVIOUS DISCUSSION FOLLOWS... ADDITIONAL DEVELOPMENT LATER TODAY A LITTLE MORE QUESTIONABLE...AS SOME OF THE MODEL DATA SUGGEST MORE SHOWER/THUNDERSTORMS DEVELOPMENT THIS AFTERNOON ALONG THE EDGE OF THE APPROACHING DRY SLOT/STEEPER LAPSE RATES...WHILE OTHERS SUGGEST DEVELOPMENT MAY HOLD OFF UNTIL TOWARDS/AFTER 290000Z WHEN SURFACE COLD FRONT/OCCLUSION MOVES THROUGH. AT THIS POINT...WILL KEEP RATHER HIGH POPS GOING THROUGH ABOUT MIDNIGHT TONIGHT...WITH THE HIGHEST POPS THROUGH ABOUT MIDDAY TODAY. SEVERE POTENTIAL TODAY AND TONIGHT A LITTLE LESS CLEAR. MODEL DATA STILL SUGGEST ADEQUATE DEEP SHEAR/LAPSE RATES BY LATER THIS AFTERNOON AND TONIGHT FOR SEVERE...ALTHOUGH THE DEEP SHEAR LOOKS A LITTLE WEAKER TODAY THAN IT DID YESTERDAY. ALSO...LARGE AMOUNTS OF CONVECTION DEVELOPING SOUTH OF THE OHIO RIVER IS GETTING CLOSE TO CUTTING OFF THE FLOW OF DEEPER MOISTURE/MORE UNSTABLE AIR INTO THE AREA. APPEARS THE BEST CHANCE FOR SEVERE WILL BE FROM THE MID AFTERNOON HOURS UNTIL ABOUT MIDNIGHT TONIGHT...EMANATING EITHER FROM DEVELOPMENT ALONG THE EDGE OF DRY SLOT LATER THIS AFTERNOON OR WITH ACTIVITY TONIGHT NEAR THE SURFACE FRONT. TODAY/S GFS MOS SEEMS TO MAY LOST ITS WARM BIAS OF THE PAST COUPLE OF DAYS...AND THE NUMBERS FOR TODAY AND TONIGHT LOOK MORE REASONABLE. ONLY MINOR ADJUSTMENTS PLANNED. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... ISSUED AT 304 AM EDT MON APR 28 2014 MODEL DATA SUGGEST A LARGE UPPER LOW WILL GRADUALLY SHIFT NORTHEAST FROM THE PLAINS INTO THE MIDWEST DURING THIS PERIOD...KEEPING THE WEATHER UNSETTLED. BY TUESDAY...MODEL DATA SUGGEST DRIER AIR WRAPPING AROUND THE UPPER LOW WILL MOVE INTO THE AREA. LAPSE RATES ARE QUITE STEEP ON TUESDAY...HOWEVER BETTER SHEAR PUSHES OFF TO THE EAST WITH TIME. WILL GO WITH CHANCE POPS FOR SHOWERS/THUNDERSTORMS ON TUESDAY AND TUESDAY NIGHT AS A SURFACE TROUGH MOVES THROUGH...WHICH MAY SERVE AS FOCUS FOR CONVECTION. THE PRESENCE OF THE STEEP LAPSE RATES ON TUESDAY SUGGEST HAIL POTENTIAL WITH ANY STRONGER CELLS THAT MAY DEVELOP. WILL KEEP SOME CHANCE POPS GOING INTO WEDNESDAY AND WEDNESDAY NIGHT AS FILLING UPPER LOW MOVES INTO THE GREAT LAKES. BASED OFF ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS HIGHS FOR TUESDAY AND WEDNESDAY LOOK A LITTLE WARM. WILL CUT A FEW DEGREES OFF THE GUIDANCE HIGHS ON BOTH DAYS. LOWS LOOK REASONABLE. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 338 AM EDT MON APR 28 2014 A LARGE UPPER LOW OVER THE GREAT LAKES THURSDAY WILL LIFT NORTH INTO SOUTHERN CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY. A CYCLONIC UPPER FLOW FROM THIS UPPER LOW WILL KEEP MOSTLY CLOUDY SKIES AND CHANCES OF SHOWERS THURSDAY INTO SATURDAY. A WEAK COLD FRONT WILL MOVE ACROSS OUR REGION EARLY SATURDAY FOLLOWED BY A HIGH PRESSURE RIDGE SATURDAY NIGHT. SEVERAL MODELS INDICATE ANOTHER CHANCE OF PRECIPITATION MAY BEGIN SUNDAY AS ANOTHER SYSTEM APPROACHES. ADDED ISOLATED THUNDER TO SUNDAY AS MODELS INDICATE MU CAPES OF UP TO 500 J/KG. OTHERWISE...ANY PRECIPITATION WILL BE ONLY BE SCATTERED LIGHT SHOWERS OR SPRINKLES. TEMPERATURES WILL REMAIN QUITE COOL THURSDAY THROUGH SATURDAY AND THEN MODERATE A LITTLE SUNDAY. ONLY MADE MINOR TWEAKS TO ALL BLEND TEMPERATURES MAINLY TO RAISE MINS SLIGHTLY THURSDAY AND FRIDAY NIGHT AS THERE WILL BE LOTS OF CLOUDS. && .AVIATION /DISCUSSION FOR 281200Z TAF ISSUANCE/... ISSUED AT 700 AM EDT MON APR 28 2014 NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS EARLY THIS MORNING. THERE COULD BE ANOTHER PERIOD OF NUMEROUS SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON OR EARLY TONIGHT PER MODELS. OTHERWISE...WILL MENTION VCSH REST OF THE PERIOD THROUGH MIDNIGHT TONIGHT. STRONG LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE SLOWLY NORTHEAST INTO THE UPPER MIDWEST. SHOWERS AND A FEW THUNDERSTORMS THIS MORNING MAY IN MVFR CONDITIONS AT TIME. MOST OF THE SHOWERS SHOULD MOVE OUT BY 15Z...BUT AREAS OF MVFR CEILINGS MAY PERSIST INTO MIDDAY. SEVERAL MODELS INDICATE THERE COULD BE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. WILL ADD ANOTHER PERIOD OF VCTS AS A RESULT FROM 20Z TO ABOUT 05Z. NAM REFLECTIVITY MODEL MOST OF THIS WILL MOVE OUT AFTER MIDNIGHT AS A DRY SLOT PUSHES INTO OUR AREA. COULD BE ANOTHER PERIOD OF MVFR CEILINGS TONIGHT. EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JAS NEAR TERM...JAS/CP SHORT TERM...JAS LONG TERM....JH AVIATION...50/JH VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1101 AM EDT MON APR 28 2014 LATEST UPDATE... UPDATE/MARINE .SYNOPSIS... ISSUED AT 325 AM EDT MON APR 28 2014 AN EXPANSIVE AND STRONG SYSTEM CENTERED ACROSS THE CENTRAL PLAINS STATES WILL DRIVE RAINFALL INTO THE AREA AHEAD OF AN ASSOCIATED FRONTAL SYSTEM TO OUR SOUTH. COOL AND WINDY CONDITIONS CAN BE EXPECTED TODAY WITH AN INCREASING CHANCE OF RAIN. RAIN WILL CONTINUE INTO EARLY TUESDAY BEFORE THE RAIN MOVES NORTH AND A SHORT PERIOD OF WARMER AIR MOVES IN ACROSS THE AREA. ADDITIONAL SHOWERS AND STORMS WILL BE POSSIBLE TUESDAY AND WEDNESDAY AS ADDITIONAL WAVES OF LOW PRESSURE MOVE THROUGH THE AREA. COOLER CONDITIONS WILL THEN RETURN FOR LATE THIS WEEK ALONG WITH A CONTINUED CHANCE OF RAIN SHOWERS. && .UPDATE... ISSUED AT 1056 AM EDT MON APR 28 2014 WILL KEEP THE WIND ADVISORY GOING. WHILE OBS ARE MOSTLY BELOW CRITERIA...THE MODELS SUGGEST MIXING HEIGHTS WILL INCREASE EARLY THIS AFTERNOON AS THE LOW LEVEL JET STRENGTHENS. WE ARE ALSO SEEING SOME POWER OUTAGES SHOWING UP ON THE CONSUMERS WEBSITE. THE BAND OF SHOWERS MOVING IN FROM THE SOUTH CONTINUES TO WEAKEN. WHILE MOST LOCATIONS WILL SEE SOME PRECIPITATION...WHAT DOES FALL TH IS AFTERNOON SHOULD BE LIGHT. SO I FEATURES LIGHT RAIN SHOWERS...AND TONED BACK THE THUNDER WORDING. MODELS SHOWING NO INSTABILITY THROUGH 00Z TUE. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 325 AM EDT MON APR 28 2014 THE MAIN CHANGE WITH THIS FCST PACKAGE IS TO EXPAND THE WIND ADVISORY TO THE EAST THROUGH THE REMAINDER OF THE CWFA FOR TODAY. OTHERWISE...THE FCST REMAINS MAINLY ON TRACK WITH A SLIGHTLY SLOWER TREND TO THE RAIN MOVING IN FOR TODAY. REGARDING THE EXPANSION OF THE WIND ADVISORY FIRST...WINDS REMAIN RATHER BRISK AND THIS EARLY MORNING HOUR ACROSS THE CWFA. SOME GUSTS OF AROUND 30 KNOTS ARE ALREADY OCCURRING THIS MORNING...AND THIS WILL ONLY INCREASE DURING THE DAYLIGHT HOURS AS THE GRADIENT TIGHTENS MORE AND AS DIURNAL MIXING WILL HELP TO BRING SOME OF THE STRONGER WINDS DOWN FROM ALOFT. IT SEEMS THAT 40 KNOTS SHOULD BE PRETTY EASY TO MIX DOWN...EVEN IN A WAA PATTERN. AS FAR AS THE RAINFALL IS CONCERNED...THE TREND OVER THE PAST 24 HOURS IS THAT OF A SLOWER ONE WITH THE FEED OF DRY AIR COMING IN ON THE BRISK ERLY WINDS AND HELPING TO DIMINISH MOST ALL PCPN TRYING TO MOVE IN. THE UPPER RIDGE AXIS THAT IS ONLY SLOWLY CRAWLING EASTWARD ACROSS THE CWFA IS FAR ENOUGH EAST AT THIS TIME THAT ENOUGH MOISTURE TRANSPORT IS OCCURRING AND A COUPLE OF SPRINKLES/LIGHT SHOWERS ARE OCCURRING ACROSS THE FAR SW CORNER OF THE CWFA. WE DO EXPECT THAT PCPN WILL BE ON THE INCREASE TODAY FROM SW TO NE AS THE UPPER LOW ROTATES A LITTLE CLOSER. THUNDER IS STILL POSSIBLE ACROSS THE FAR SOUTH THIS AFTERNOON AS SLIGHTLY NEGATIVE ELEVATED LI/S MOVE UP INTO THE AREA. SEVERE WX IS NOT EXPECTED AT THIS TIME WITH NO SFC INSTABILITY EXPECTED THROUGH TONIGHT. THE BEST THREAT OF RAIN SHOWERS AND STORMS LOOKS TO COME THIS EVENING AND INTO THE OVERNIGHT HOURS. THE BEST MOISTURE AXIS PASSES FROM SOUTH TO NORTH DURING THIS TIME FRAME...OUT AHEAD OF THE OCCLUDED FRONT. WE CONTINUE TO EXPECT LITTLE THREAT OF SEVERE STORMS TONIGHT ONCE AGAIN AS THE INSTABILITY WILL ONCE AGAIN BE ELEVATED. THE RAIN CHANCES WILL THEN DIMINISH LATE TONIGHT AND EARLY TUE MORNING AS THE MOISTURE TRANSPORT AND LLJ PEEL OFF TO THE EAST OF THE STATE. WE CONTINUE TO LOOK FOR A BRIEF WARM UP FOR THE DAY ON TUE WITH 70 DEGREE TEMPERATURES LOOKING MORE LIKELY. THE FRONT WILL BE NEAR THE SRN STATE BORDER AT 12Z ON TUE. THE UPPER LOW COMING IN FROM THE WEST WILL PUSH THE FRONT NORTH THROUGH THE AREA. EVEN THOUGH IT WILL NOT BE THE TRUE WARM SECTOR...H850 TEMPS ARE STILL VERY MILD...AND WILL WE TAP THAT WARMTH AS THE DRY SLOT MOVES IN AND WE GET SOME SUN. H850 TEMPS AROUND +10 C WILL SUPPORT MANY LOCATIONS HITTING 70. IT DOES LOOK LIKE LATE IN THE AFTERNOON WE WILL SEE CONVECTION TRY TO FIRE OVERHEAD AS A WAVE ROTATES AROUND THE UPPER LOW AND MOVES TOWARD THE AREA. THERE IS SOME CONCERN WITH CONVECTION FIRING ON TUE AFTERNOON AS STRONG JET STREAM WINDS WILL STILL BE OVERHEAD ACROSS SE LOWER. THIS WILL PROVIDE FOR GOOD SHEAR IN THE DEEP LAYER. MUCH BETTER INSTABILITY /LI/S OF -6 TO -8C/ WILL BE FOUND FURTHER SE ALSO. WE STAY RELATIVELY WARM THROUGH MOST OF WED AS THE LOW LEVEL COLD AIR DOES NOT COME IN UNTIL LATE WED AFTERNOON AND WED EVENING. THIS IS THE CASE AS THE UPPER LOW HELPS ANOTHER WAVE TOWARD THE AREA AND THE FLOW AHEAD OF IT WILL CONTINUE TO SUPPORT WARM TEMPS UNTIL THE LOW MOVES THROUGH LATE WED. SHOWERS AND STORMS WILL REMAIN POSSIBLE AHEAD OF THIS WAVE FOR TUE NIGHT AND WED. WE WILL LIKELY NOT REACH 70 AGAIN...BUT WE SHOULD BE WELL INTO THE 60S. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 325 AM EDT MON APR 28 2014 LITTLE QUESTION OCCASIONAL SHOWERS AND COOLER THAN NORMAL TEMPERATURES WILL PREVAIL THROUGH SATURDAY AS WE REMAIN ON THE CYCLONIC SIDE OF THE UPPER JET WITH A FAIR AMOUNT OF DEEP MOISTURE. SOME QUESTION ARISES WHAT HAPPENS FROM SUNDAY AND BEYOND SO I KEEP THE LOW CHANCE POP FOR SUNDAY BUT IT MAY BE WE ACTUALLY GET TO SEE THE SUN ONCE AGAIN BY SUNDAY AS THE UPPER JET MAY FINALLY LIFT NORTH OF LOWER MICHIGAN MY THEN. MODEL CONTINUE TO BE IN GOOD AGREEMENT WITH THE CLOSED UPPER LOW REMAINING IN PLACE INTO AS LEAST SATURDAY. THE 500 MB HEIGHT ANOMALIES ARE ON THE ORDER OF 2-3 STD BELOW NORMAL INTO SATURDAY OVER THE LOWER GREAT LAKES. 850 MB TEMPERATURES ARE 1 TO 2 STD BELOW NORMAL INTO SATURDAY. THE MODELS CONTINUE TO FEATURE THAT ARCTIC JET STREAK FEEDING INTO THE SYSTEM FRIDAY INTO SATURDAY. THAT WILL MAINTAIN THIS PATTERN INTO SATURDAY FOR SURE. FROM SUNDAY ON THERE IS A QUESTION OF WHETHER ANOTHER PACIFIC SYSTEM CAN BREAK THROUGH THE WESTERN RIDGE TO PUSH THIS PATTERN OUT OF THE WAY OR IF WE WILL CONTINUE TO SEE MORE IN A SERIES OF NORTHERN STREAM OF SYSTEMS. I KEEP LOW CHANCE POPS FOR SUNDAY JUST IN CASE THE LATER OCCURS. AS FOR THE SHOWERS WEDNESDAY NIGHT THROUGH SATURDAY AFTERNOON... GIVEN THE DEEP CYCLONIC FLOW...DEEP MOISTURE AND SATURATED DGZ PLUS SURFACE CONVERGENCE ALONG THE LAKE MICHIGAN SHORE AREAS INTO SATURDAY I HAVE TO BELIEVE WE WILL CONTINUE TO SEE LIGHT SHOWER THROUGH THIS ENTIRE PERIOD. I HAVE CONTINUED THE LIKELY POPS INTO FRIDAY AND HIGH CHANCE INTO SATURDAY. TEMPERATURES WILL BE BETWEEN 5 AND 10 DEGREES BELOW NORMAL THROUGH THIS PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 741 AM EDT MON APR 28 2014 OUR MAJOR QUESTION IS WHEN WILL THE RAIN ARRIVE AND MORE THAN THAT WHEN WILL THE MVFR/IFR CIGS/VSBY MOVE IN AS THE STORM TO OUR SOUTHWEST SLOWLY MOVES TOWARD THE REGION. THE HUDSON BAY HIGH CONTINUES TO FEED VERY DRY AIR FROM THE EAST AND IT WILL CONTINUE TO ERROD THE RAIN AS MOVES INTO SOUTHWEST MICHIGAN. THIS IS NOT TO SAY THERE WILL NOT BE SOME LIGHT RAIN SHOWERS BUT IT SEEMS THE BULK OF THE SIGNIFICANT RAIN WILL LARGELY STAY NEAR AND SOUTH OF INTERSTATE 94 TODAY (USING THE RAP13 MODEL AND HRRR ). I DID BRING THE SHOWERS INTO THE AZO...BTL AND JXN BY LATE MORNING BUT I DID NOT BRING THOSE SHOWERS INTO GRR...MKG AND LAN TILL LATE AFTERNOON... EVEN THEN VSBY SHOULD BE VFR FOR THE MOST PART. I PUT VCSH AT ALL THE TAF SITES DURING THE MID MORNING HOURS SINCE SHOWERS WILL BE AROUND BUT VERY LIGHT (MOSTLY SPRINKLES). THE MVFR CIGS/VSBY SHOULD REACH THE I-94 TAT SITES BY LATE AFTERNOON THEN SPREAD INTO THE I-96 SITES AFTER 00Z. ANY THUNDERSTORM ACTIVITY SHOULD HOLD OFF UNTIL TUESDAY. && .MARINE... ISSUED AT 1056 AM EDT MON APR 28 2014 GALE WARNING TO CONTINUE. SOME GUSTS OVER GALE FORCE ALREADY OBSERVED. WINDS LIKELY TO INCREASE AS THE LOW LEVEL JET STRENGTHENS AND MIXING HEIGHTS INCREASE. && .HYDROLOGY... ISSUED AT 241 PM EDT SUN APR 27 2014 I DOWNPLAYED THE QPF THROUGH TUE. THE DRY AIRMASS CURRENTLY IN PLACE SHOULD ACT TO DELAY THE ARRIVAL OF THE SHOWERS. MODELS ARE GENERALLY SHOWING A DIMINISHING TREND TO THE INITIAL BAND OF SHOWERS DURING THE DAY ON MONDAY. STILL LOOKS LIKE ENOUGH RAIN TO CAUSE RIVER RISES. ANOTHER BATCH OF RAIN TUE NIGHT INTO WED MAY BE HEAVY. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ037>040-043>046- 050>052-056>059-064>067-071>074. LM...GALE WARNING UNTIL 8 AM EDT TUESDAY FOR LMZ844>849. && $$ UPDATE...MJS SYNOPSIS...NJJ SHORT TERM...NJJ LONG TERM...WDM AVIATION...WDM HYDROLOGY...MJS MARINE...MJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
741 AM EDT MON APR 28 2014 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 325 AM EDT MON APR 28 2014 AN EXPANSIVE AND STRONG SYSTEM CENTERED ACROSS THE CENTRAL PLAINS STATES WILL DRIVE RAINFALL INTO THE AREA AHEAD OF AN ASSOCIATED FRONTAL SYSTEM TO OUR SOUTH. COOL AND WINDY CONDITIONS CAN BE EXPECTED TODAY WITH AN INCREASING CHANCE OF RAIN. RAIN WILL CONTINUE INTO EARLY TUESDAY BEFORE THE RAIN MOVES NORTH AND A SHORT PERIOD OF WARMER AIR MOVES IN ACROSS THE AREA. ADDITIONAL SHOWERS AND STORMS WILL BE POSSIBLE TUESDAY AND WEDNESDAY AS ADDITIONAL WAVES OF LOW PRESSURE MOVE THROUGH THE AREA. COOLER CONDITIONS WILL THEN RETURN FOR LATE THIS WEEK ALONG WITH A CONTINUED CHANCE OF RAIN SHOWERS. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 325 AM EDT MON APR 28 2014 THE MAIN CHANGE WITH THIS FCST PACKAGE IS TO EXPAND THE WIND ADVISORY TO THE EAST THROUGH THE REMAINDER OF THE CWFA FOR TODAY. OTHERWISE...THE FCST REMAINS MAINLY ON TRACK WITH A SLIGHTLY SLOWER TREND TO THE RAIN MOVING IN FOR TODAY. REGARDING THE EXPANSION OF THE WIND ADVISORY FIRST...WINDS REMAIN RATHER BRISK AND THIS EARLY MORNING HOUR ACROSS THE CWFA. SOME GUSTS OF AROUND 30 KNOTS ARE ALREADY OCCURRING THIS MORNING...AND THIS WILL ONLY INCREASE DURING THE DAYLIGHT HOURS AS THE GRADIENT TIGHTENS MORE AND AS DIURNAL MIXING WILL HELP TO BRING SOME OF THE STRONGER WINDS DOWN FROM ALOFT. IT SEEMS THAT 40 KNOTS SHOULD BE PRETTY EASY TO MIX DOWN...EVEN IN A WAA PATTERN. AS FAR AS THE RAINFALL IS CONCERNED...THE TREND OVER THE PAST 24 HOURS IS THAT OF A SLOWER ONE WITH THE FEED OF DRY AIR COMING IN ON THE BRISK ERLY WINDS AND HELPING TO DIMINISH MOST ALL PCPN TRYING TO MOVE IN. THE UPPER RIDGE AXIS THAT IS ONLY SLOWLY CRAWLING EASTWARD ACROSS THE CWFA IS FAR ENOUGH EAST AT THIS TIME THAT ENOUGH MOISTURE TRANSPORT IS OCCURRING AND A COUPLE OF SPRINKLES/LIGHT SHOWERS ARE OCCURRING ACROSS THE FAR SW CORNER OF THE CWFA. WE DO EXPECT THAT PCPN WILL BE ON THE INCREASE TODAY FROM SW TO NE AS THE UPPER LOW ROTATES A LITTLE CLOSER. THUNDER IS STILL POSSIBLE ACROSS THE FAR SOUTH THIS AFTERNOON AS SLIGHTLY NEGATIVE ELEVATED LI/S MOVE UP INTO THE AREA. SEVERE WX IS NOT EXPECTED AT THIS TIME WITH NO SFC INSTABILITY EXPECTED THROUGH TONIGHT. THE BEST THREAT OF RAIN SHOWERS AND STORMS LOOKS TO COME THIS EVENING AND INTO THE OVERNIGHT HOURS. THE BEST MOISTURE AXIS PASSES FROM SOUTH TO NORTH DURING THIS TIME FRAME...OUT AHEAD OF THE OCCLUDED FRONT. WE CONTINUE TO EXPECT LITTLE THREAT OF SEVERE STORMS TONIGHT ONCE AGAIN AS THE INSTABILITY WILL ONCE AGAIN BE ELEVATED. THE RAIN CHANCES WILL THEN DIMINISH LATE TONIGHT AND EARLY TUE MORNING AS THE MOISTURE TRANSPORT AND LLJ PEEL OFF TO THE EAST OF THE STATE. WE CONTINUE TO LOOK FOR A BRIEF WARM UP FOR THE DAY ON TUE WITH 70 DEGREE TEMPERATURES LOOKING MORE LIKELY. THE FRONT WILL BE NEAR THE SRN STATE BORDER AT 12Z ON TUE. THE UPPER LOW COMING IN FROM THE WEST WILL PUSH THE FRONT NORTH THROUGH THE AREA. EVEN THOUGH IT WILL NOT BE THE TRUE WARM SECTOR...H850 TEMPS ARE STILL VERY MILD...AND WILL WE TAP THAT WARMTH AS THE DRY SLOT MOVES IN AND WE GET SOME SUN. H850 TEMPS AROUND +10 C WILL SUPPORT MANY LOCATIONS HITTING 70. IT DOES LOOK LIKE LATE IN THE AFTERNOON WE WILL SEE CONVECTION TRY TO FIRE OVERHEAD AS A WAVE ROTATES AROUND THE UPPER LOW AND MOVES TOWARD THE AREA. THERE IS SOME CONCERN WITH CONVECTION FIRING ON TUE AFTERNOON AS STRONG JET STREAM WINDS WILL STILL BE OVERHEAD ACROSS SE LOWER. THIS WILL PROVIDE FOR GOOD SHEAR IN THE DEEP LAYER. MUCH BETTER INSTABILITY /LI/S OF -6 TO -8C/ WILL BE FOUND FURTHER SE ALSO. WE STAY RELATIVELY WARM THROUGH MOST OF WED AS THE LOW LEVEL COLD AIR DOES NOT COME IN UNTIL LATE WED AFTERNOON AND WED EVENING. THIS IS THE CASE AS THE UPPER LOW HELPS ANOTHER WAVE TOWARD THE AREA AND THE FLOW AHEAD OF IT WILL CONTINUE TO SUPPORT WARM TEMPS UNTIL THE LOW MOVES THROUGH LATE WED. SHOWERS AND STORMS WILL REMAIN POSSIBLE AHEAD OF THIS WAVE FOR TUE NIGHT AND WED. WE WILL LIKELY NOT REACH 70 AGAIN...BUT WE SHOULD BE WELL INTO THE 60S. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 325 AM EDT MON APR 28 2014 LITTLE QUESTION OCCASIONAL SHOWERS AND COOLER THAN NORMAL TEMPERATURES WILL PREVAIL THROUGH SATURDAY AS WE REMAIN ON THE CYCLONIC SIDE OF THE UPPER JET WITH A FAIR AMOUNT OF DEEP MOISTURE. SOME QUESTION ARISES WHAT HAPPENS FROM SUNDAY AND BEYOND SO I KEEP THE LOW CHANCE POP FOR SUNDAY BUT IT MAY BE WE ACTUALLY GET TO SEE THE SUN ONCE AGAIN BY SUNDAY AS THE UPPER JET MAY FINALLY LIFT NORTH OF LOWER MICHIGAN MY THEN. MODEL CONTINUE TO BE IN GOOD AGREEMENT WITH THE CLOSED UPPER LOW REMAINING IN PLACE INTO AS LEAST SATURDAY. THE 500 MB HEIGHT ANOMALIES ARE ON THE ORDER OF 2-3 STD BELOW NORMAL INTO SATURDAY OVER THE LOWER GREAT LAKES. 850 MB TEMPERATURES ARE 1 TO 2 STD BELOW NORMAL INTO SATURDAY. THE MODELS CONTINUE TO FEATURE THAT ARCTIC JET STREAK FEEDING INTO THE SYSTEM FRIDAY INTO SATURDAY. THAT WILL MAINTAIN THIS PATTERN INTO SATURDAY FOR SURE. FROM SUNDAY ON THERE IS A QUESTION OF WHETHER ANOTHER PACIFIC SYSTEM CAN BREAK THROUGH THE WESTERN RIDGE TO PUSH THIS PATTERN OUT OF THE WAY OR IF WE WILL CONTINUE TO SEE MORE IN A SERIES OF NORTHERN STREAM OF SYSTEMS. I KEEP LOW CHANCE POPS FOR SUNDAY JUST IN CASE THE LATER OCCURS. AS FOR THE SHOWERS WEDNESDAY NIGHT THROUGH SATURDAY AFTERNOON... GIVEN THE DEEP CYCLONIC FLOW...DEEP MOISTURE AND SATURATED DGZ PLUS SURFACE CONVERGENCE ALONG THE LAKE MICHIGAN SHORE AREAS INTO SATURDAY I HAVE TO BELIEVE WE WILL CONTINUE TO SEE LIGHT SHOWER THROUGH THIS ENTIRE PERIOD. I HAVE CONTINUED THE LIKELY POPS INTO FRIDAY AND HIGH CHANCE INTO SATURDAY. TEMPERATURES WILL BE BETWEEN 5 AND 10 DEGREES BELOW NORMAL THROUGH THIS PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 741 AM EDT MON APR 28 2014 OUR MAJOR QUESTION IS WHEN WILL THE RAIN ARRIVE AND MORE THAN THAT WHEN WILL THE MVFR/IFR CIGS/VSBY MOVE IN AS THE STORM TO OUR SOUTHWEST SLOWLY MOVES TOWARD THE REGION. THE HUDSON BAY HIGH CONTINUES TO FEED VERY DRY AIR FROM THE EAST AND IT WILL CONTINUE TO ERROD THE RAIN AS MOVES INTO SOUTHWEST MICHIGAN. THIS IS NOT TO SAY THERE WILL NOT BE SOME LIGHT RAIN SHOWERS BUT IT SEEMS THE BULK OF THE SIGNIFICANT RAIN WILL LARGELY STAY NEAR AND SOUTH OF INTERSTATE 94 TODAY (USING THE RAP13 MODEL AND HRRR ). I DID BRING THE SHOWERS INTO THE AZO...BTL AND JXN BY LATE MORNING BUT I DID NOT BRING THOSE SHOWERS INTO GRR...MKG AND LAN TILL LATE AFTERNOON... EVEN THEN VSBY SHOULD BE VFR FOR THE MOST PART. I PUT VCSH AT ALL THE TAF SITES DURING THE MID MORNING HOURS SINCE SHOWERS WILL BE AROUND BUT VERY LIGHT (MOSTLY SPRINKLES). THE MVFR CIGS/VSBY SHOULD REACH THE I-94 TAT SITES BY LATE AFTERNOON THEN SPREAD INTO THE I-96 SITES AFTER 00Z. ANY THUNDERSTORM ACTIVITY SHOULD HOLD OFF UNTIL TUESDAY. && .MARINE... ISSUED AT 325 AM EDT MON APR 28 2014 WE HAVE CONTINUED THE GALE WARNING FOR THE ENTIRE NEARSHORE AND ADDED 12 HRS TO THE DURATION FOR THIS FCST PACKAGE. COASTAL OBSERVATIONS INDICATE THAT WINDS ARE ON THE VERGE OF GALE CRITERIA ALREADY EARLY THIS MORNING. WE EXPECTED TO WIND GUSTS TO CONTINUE WITH THE FLOW BEING AN OFFSHORE ONE AND DIURNAL MIXING INLAND HELPING TO INCREASE THE GUSTS AFTER SUNRISE TODAY. STRONGER WINDS JUST OFF THE SFC WILL REMAIN FOR MOST OF THE NIGHT BEFORE DIMINISHING ON TUE. && .HYDROLOGY... ISSUED AT 241 PM EDT SUN APR 27 2014 I DOWNPLAYED THE QPF THROUGH TUE. THE DRY AIRMASS CURRENTLY IN PLACE SHOULD ACT TO DELAY THE ARRIVAL OF THE SHOWERS. MODELS ARE GENERALLY SHOWING A DIMINISHING TREND TO THE INITIAL BAND OF SHOWERS DURING THE DAY ON MONDAY. STILL LOOKS LIKE ENOUGH RAIN TO CAUSE RIVER RISES. ANOTHER BATCH OF RAIN TUE NIGHT INTO WED MAY BE HEAVY. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ037>040-043>046- 050>052-056>059-064>067-071>074. LM...GALE WARNING UNTIL 8 AM EDT TUESDAY FOR LMZ844>849. && $$ SYNOPSIS...NJJ SHORT TERM...NJJ LONG TERM...WDM AVIATION...WDM HYDROLOGY...MJS MARINE...NJJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
717 AM EDT MON APR 28 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 511 AM EDT MON APR 28 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER LEVEL TROUGH FROM THE NW CONUS THROUGH THE CENTRAL PLAINS WITH A CLOSED LOW OVER NEBRASKA. DOWNSTREAM A RIDGE EXTENDED FROM THE SE CONUS THROUGH WRN LAKES INTO MANITOBA. AT THE SFC...A BRISK ERLY FLOW PREVAILED THROUGH THE NRN LAKES BETWEEN HIGH PRES OVER HUDSON BAY AND A DEEP LOW OVER ERN NEBRASKA. ISENTROPIC ASCENT AS NOTED ON THE 295K SFC HAS PRODUCED SEVERAL BANDS OF LIGHT PCPN OVER UPPER MI THIS MORNING BUT THIS PCPN HAS FALLEN MAINLY AS JUST SPRINKLES/FLURRIES AS IT ENCOUNTERS VERY DRY AIR BELOW 750 MB. TODAY...MODELS CONSISTENT SHOWING SYSTEM OVER ERN NEBRASKA STALLING AND BEGINNING TO OCCLUDE TODAY. MODELS SHOW WEAKENING ISENTROPIC ASCENT OVER UPR MI AND A LACK OF 850-700 MB MOISTURE ADVECTION INTO THE REGION. THIS FACT ALONG WITH MID-LVL RDG GENERALLY STAYING IN PLACE SHOULD KEEP MUCH OF THE CWA DRY TODAY. INCREASING 850-700 MB MOISTURE ADV AND ISENTROPIC ASCENT COULD BRING IN A BETTER CHC OF RAIN TOWARD 00Z THIS EVENING OVER MAINLY FAR SCNTRL CWA. TONIGHT...MODELS SHOW MORE SUBSTANTIAL SHORTWAVE LOBE ROTATING NORTHWARD AHEAD OF PLAINS CLOSED LOW WHICH IN TURN WILL PROPEL 850 MB WARM FRONT NORTHWARD INTO THE SE CWA LATE TONIGHT. INCREASING ISENTROPIC ASCENT AND 850-700 MB MOISTURE ADVECTION SPREADING IN FROM THE SSE AHEAD OF THE WARM FRONT WILL BRING INCREASING RAIN CHCS INTO SCNTRL CWA THIS EVENING SPREADING INTO THE REST OF THE SE HALF OF THE CWA OVERNIGHT TONIGHT. THICKNESS VALUES AND SOUNDINGS SUGGEST SNOW MAY MIX WITH RAIN OVER NCNTRL AND NW CWA LATE TONIGHT BUT PCPN SHOULD BE LIGHT THAT ANY SNOW AMTS WILL HAVE LITTLE IMPACT ON TRAVEL. MODEL QPF INDICATES SCNTRL CWA COULD SEE FROM .25 TO PERHAPS .75 OF AN INCH OF RAINFALL TONIGHT WHICH WILL ADD TO RUNOFF FOR AREA STREAMS AND RIVERS INTO MIDWEEK. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 358 AM EDT MON APR 28 2014 FOCUSED ATTENTION ON TUE-WED NIGHT TIME FRAME AS MOST SIGNIFICANT PRECIP IS EXPECTED DURING THAT TIME. THE SETUP FOR MID WEEK IS QUITE INTERESTING ACROSS THE CONUS AS A DEEP CLOSED UPPER LOW IS OVER THE CENTRAL CONUS...BORDERED ON THE W...N AND E BY AMPLIFIED UPPER RIDGING. ALSO...AT THE START OF THE LONG TERM /12 TUE/...THE UPPER LOW WILL BE ABSORBING A WEAK UPPER LOW THAT ORIGINATED OVER QUEBEC. THE SYSTEM WILL BE QUITE WRAPPED UP...WITH GREAT MOISTURE TRANSPORT FROM BOTH THE GULF OF MEXICO AND THE ATLANTIC THAT FOCUSES OVER THE LOWER GREAT LAKES BEFORE WRAPPING W ACROSS THE CWA AND EVENTUALLY TO THE W OF THE LOW /WHICH IS OVER IA AT 12Z TUE/. PRECIP TUE WILL BE PRIMARILY FORCED BY 50-60KT 900-700MB WINDS...RESULTING IN GOOD MOISTURE TRANSPORT IN THIS LAYER AS WELL AS STRONG ISENTROPIC ASCENT AS ISENTROPIC SURFACES INCREASE IN HEIGHT BY AROUND 1KM FROM UPSTREAM TO DOWNSTREAM ACROSS THE CWA. PWAT VALUES WILL BE 0.75-1.00 INCHES...OR GENERALLY 150-200 PERCENT OF NORMAL. ANOTHER SIGNIFICANT FORCING MECHANISM IS A SHORTWAVE THAT MODELS SHOW MOVING ACROSS THE CWA TUE...WHICH LEADS TO STEEP 700-500MB LAPSE RATES OF JUST OVER 7C/KM. ADDITIONALLY...THE LEFT EXIT REGION OF AN UPPER JET WILL BE ACROSS THE CWA. ALL THESE INGREDIENTS COME TOGETHER TO PRODUCE SIGNIFICANT QPF AMOUNTS FROM THE MODELS LATE MON NIGHT INTO TUE. THE MOST PRECIP SHOULD FALL NEAR LAKE MICHIGAN WHERE THE BEST FORCING AND MOISTURE IS EXPECTED. EVEN THE LOWER RES MODELS /THAT TYPICALLY DO NOT PERFORM AS WELL IN THIS TYPE OF SITUATION/ HAVE UP TO AN INCH OF QPF NEAR LAKE MICHIGAN...WHILE THE NAM HAS THE MOST QPF AT 2.25 INCHES. WILL GO WITH A CONSENSUS APPROACH OF GFS/ECMWF AND REGIONAL GEM /WHICH HAS UP TO 1.85 INCHES/...WHICH INCORPORATES MON NIGHT /SHORT TERM/. THE ECMWF/GFS HAVE THE BEST PRECIP LATE MON NIGHT INTO TUE MORNING...WHILE THE NAM HAS THE BEST PRECIP ON TUE. THE REGIONAL GEM IS BETWEEN THE NAM AND GFS/ECMWF. A COMPLICATING FACTOR TO THIS TIME FRAME IS THAT MODEL TEMP PROFILES FAVOR PRECIP TO BE SNOW OVER WRN UPPER MI AND RAIN NEAR LAKE MICHIGAN AND E...WITH A MIX BETWEEN. DUE TO SFC TEMPS BEING NEAR OR ABOVE FREEZING AND STRONG SOLAR EFFECTS THIS TIME OF YEAR...ACCUMULATIONS ON PAVED SURFACES SHOULD BE MINIMAL...BUT GRASSY SURFACES OVER THE HIGHER TERRAIN OF WRN UPPER MI COULD SEE 2-3 INCHES OF SNOW. GIVEN VERY MINIMAL EXPECTED IMPACTS TO TRAVEL...WILL CONTINUE TO NOT MENTION SNOW IN THE HWO. DEPENDING ON EXACT PRECIP AMOUNTS...COULD SEE SOME SIGNIFICANT RISES ON AREA RIVERS. ANOTHER SHOT AT GOOD ISENTROPIC ASCENT AND A STRONG SHORTWAVE ARE SHOWN BY MODELS FOR WED AS THE UPPER LOW CONTINUES TO WEAKEN AND BEGINS MOVING NE TOWARD THE CWA. SIGNALS FOR PRECIP AMOUNTS AND TRENDS ARE A LOT MORE MUDDLED ON WED INTO WED NIGHT AS THE CWA WILL BE MORE REMOVED FROM THE BEST MOISTURE TRANSPORT...WHICH WILL BE MORE FOCUSED E AND N OF THE CWA. THINK THAT MUCH OF THE CWA WILL SEE PRECIP...WITH POTENTIAL FOR UP TO AN INCH OF ADDITIONAL PRECIP DURING THIS TIME PERIOD. USED A BROAD CONSENSUS OF GUIDANCE DURING THIS PERIOD. THE UPPER LOW WILL CONTINUE TO WEAKEN AND MOVE SLOWLY NE INTO LATE WEEK BEFORE ADDITIONAL UPPER LEVEL ENERGY MOVES INTO THE REGION LATE THIS WEEK INTO THE WEEKEND...LEADING TO CONTINUED WET WEATHER...BUT AMOUNTS WILL BE LOWER THROUGH THE REST OF THE WEEK. USED A CONSENSUS OF GUIDANCE FOR THIS PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 711 AM EDT MON APR 28 2014 VFR CONDITIONS WILL PREVAIL UNTIL LATE TONIGHT. THERE COULD BE SOME INTERMITTENT LIGHT RAIN/SPRINKLES AT KIWD THIS MORNING BUT OTHERWISE MID CLOUDS AND VFR CONDITIONS WILL PREVAIL. INCREASING MOISTURE AHEAD OF A WARM FRONT WILL BRING INCREASING CHCS OF RAIN LATE TONIGHT AT ALL TAF SITES AS CIGS LOWER TO MVFR AND POSSIBLY IFR. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 511 AM EDT MON APR 28 2014 EAST TO NORTHEAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE DEEPENS OVER THE PLAINS. EXPECT ENE GALES TO 35KTS OVER MUCH OF WRN LAKE SUPERIOR INTO TUE MORNING. THERE IS ALSO A CHANCE FOR ENE GALES TO 35 KNOTS OVER CENTRAL LAKE SUPERIOR FOR LATE TONIGHT INTO TUE SO HAVE ISSUED A GALE WATCH FOR LSZ264-266 WINDS SHOULD GRADUALLY DIMINISH LATE TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE EVENING. WINDS ARE EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED INTO FRI AS THE LOW FILLS AND REMAINS NEAR UPPER MICHIGAN. && .HYDROLOGY... ISSUED AT 358 AM EDT MON APR 28 2014 RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER NEAR NAHMA JUNCTION. AT LEAST THROUGH TONIGHT THESE RIVERS ARE NOT EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS WILL START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF HIGHER QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK. REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR LSZ264>266. GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ TUESDAY FOR LSZ162-263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...TITUS AVIATION...VOSS MARINE...VOSS HYDROLOGY...TITUS
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
633 AM CDT Mon Apr 28 2014 .SHORT TERM: (Through Late This Afternoon) Issued at 152 AM CDT Mon Apr 28 2014 Latest HRRR weakens most of the convection currently across our forecast area, or shifts it southeast of the region by 12z Monday. There may be a brief lull in the convection early this morning, then new convection should break out late this morning and early this afternoon from Edina to Quincy and south through the St Louis metro area to the FAM area, then shift eastward through our IL counties later this afternoon. This will occur as a shortwave ejects out of the southern Plains into southeast MO and a cold front/dry line surges eastward into eastern MO by 00z Tue. Should have CAPEs up to 2000-2500 J/Kg ahead of the cold front around 18z Monday with surface LI values down to around -10. Strongest low-mid level wind shear should be across southeast MO and southwest IL with strong 500 mb wind max moving through AR into portions of southeast MO, southern IL, and western portions of TN and KY. The severe weather threat should be over the eastern portion of our area, in portions of west central and southwest IL with the primary threat being large hail and damaging winds. This will occur from the late morning, through the afternoon and into the early evening hours. GKS .LONG TERM: (Tonight through Sunday) Issued at 341 AM CDT Mon Apr 28 2014 The showers and thunderstorms should be confined to areas east of the Mississippi River this evening and should be weakening by late evening as the higher surface dewpoints and instability shifts east of our forecast area. Little if any precipitation should be left late tonight. Temperatures will be cooler tonight due to low level cold air advection in our area south of the upper level and associated surface low. More showers and a few thunderstorms on Tuesday as the moisture wraps around the slow moving upper/surface low north of our area. The best chance for rain will be across the northwest half of our forecast area. The models keep the showers going Tuesday night as shortwaves rotate around the mid-upper level low. The gradual cooling trend will continue with well below normal temperatures for Wednesday and Wednesday night. The GFS and ECMWF models drop the zero degree C 850 mb isotherm southeastward into our forecast area Tuesday night or Wednesday, the cooler NAM even earlier. Although there will likely be rain across our area again on Wednesday it should be on the light side. The rain should be mainly diurnal on Thursday and Friday and favor the northern portion of our forecast area as the upper level low weakens and moves into the Great Lakes region. Will see warmer high temperatures for the weekend as the upper level heights begin to rise and southerly surface/low level flow returns Saturday night. Low-mid level warm air advection ahead of a weak shortwave and associated surface low may bring showers to the extreme northern portion of our forecast area late Saturday night and Sunday. GKS && .AVIATION: (For the 12z TAFs through 12z Tuesday Morning) Issued at 633 AM CDT Mon Apr 28 2014 VFR conditions outside of TSRA will prevail at the TAF sites thru the valid period. Another round of TSRA is expected to develop mainly east of the MS river around midday, leaving UIN and the STL Metro sites on the backedge of what does form. Due to these TAF sites being on the backedge, have elected to keep VCTS mention versus TEMPO until we get closer to initiation time. What does develop should shove off to the northeast by late afternoon. Gusty southerly winds are expected, diminishing tonight. Specifics for KSTL: VFR outside of TSRA thru the valid period. Another round of TSRA is expected to develop over the STL Metro area around midday with what does form shoving off to the northeast by mid-afternoon. Due to the terminal anticipated to being on the backedge, have elected to keep VCTS mention versus TEMPO until we get closer to initiation time. Gusty southerly winds are expected, diminishing tonight. TES && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1040 AM EDT MON APR 28 2014 .SYNOPSIS...A STALLED SURFACE BOUNDARY ACROSS CENTRAL NC WILL LIFT NORTHWARD AS A WARM FRONT THIS AFTERNOON. A WARM...MOIST AND UNSTABLE AIR MASS WILL RESIDE OVER CENTRAL NC TONIGHT THROUGH WEDNESDAY NIGHT. A SERIES OF UPPER LEVEL DISTURBANCES WILL INTERACT WITH THIS AIR MASS TRIGGERING SHOWERS AND THUNDERSTORMS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1040 AM MONDAY... A WEAK COLD FRONT AND SHALLOW STABLE AIRMASS SETTLED SOUTH THROUGH THE AREAS OVERNIGHT...MAKING IT ESSENTIALLY TO THE SC BORDER AND CREATING A RATHER LARGE GRADIENT IN TEMPS AND DEWPOINTS. THE PARENT SURFACE HIGH BEHIND THE FRONT WILL CONTINUE TO SUPPLY A NORTHEASTERLY WIND TODAY...BUT WITH CLEARING ALREADY OCCURRING ACROSS THE SOUTHERN PIEDMONT AND A SOUTHWESTERLY WIND AT 925MB...THE BOUNDARY SHOULD MIX BACK TO THE NORTH TODAY. HIGHS FOR TODAY ARE TOUGH GIVEN THE VARYING CLOUD COVER AND SLOWLY VEERING SURFACE WINDS ACROSS THE SOUTH. TEMPS OVER PORTION OF SC HAVE ALREADY JUMPED INTO THE MID AND UPPER 70S. ACROSS THE NORTH THE AMOUNT OF SUN IS A BIT MORE UNCERTAIN...WITH ADDITIONAL CLOUD COVER MOVING EAST ACROSS THE BLUE RIDGE. ADJUSTMENTS TO TEMP TRENDS YIELDS MID 60S NORTH TO LOWER 80S SOUTH. REGARDING CONVECTION... THE MAIN LIMITING FACTOR IS THE SHORTWAVE RIDGE OVERHEAD...BUT FORECAST SOUNDINGS SUGGEST HEATING AND MOISTURE RECOVER WILL BE ABLE TO OVERCOME THE MID-LEVEL CAP. THE LATEST RAP RUNS SHOW AN INSTABILITY AXIS ON THE ORDER OF 500-1000 J/KG MLCAPE NOSING NORTH ACROSS THE SOUTHERN PIEDMONT BY MIDDAY...WITH DESTABILIZATION TO THE EAST CROSS THE SANDHILLS AND SOUTHERN COASTAL PLAIN WITH TIME. THE SEEMS TO MESH WELL WITH SATELLITE TRENDS AND DEWPOINTS RECOVERING INTO THE MID TO UPPER 60S....SO AREAS SOUTH OF HWY 64 LOOK TO MOST FAVORABLE FOR CONVECTION THIS AFTERNOON. BULK SHEAR WILL BE STRONGER TO THE NORTH...BUT GUIDANCE SUGGESTS AS MUCH AS 30KT WHICH COULD SUPPORT SOME MULTICELL CLUSTERS WITH A GENERAL MOTION FROM WEST TO EAST. THE MAIN THREAT FROM STORMS WILL BE DAMAGING WINDS...THOUGH STORMS FARTHER NORTH IN THE VICINITY OF THE RETREATING SURFACE BOUNDARY AND BACKED SURFACE WINDS WILL ENCOUNTER GREATER SHEAR AND HAVE A BETTER CHANCE OF ROTATING. AGAIN...THE THREAT OF SEVERE WEATHER IS CONDITIONED UPON DEVELOPMENT OF STORMS...WHICH SHOULD BE MOSTLY SCATTERED IN NATURE. -SMITH TONIGHT...SFC FRONT PROJECTED TO BE STALLED ACROSS THE NORTHERN COUNTIES. WEAK CONVERGENCE ALONG THIS FEATURE WILL MAINTAIN A THREAT FOR SCATTERED SHOWERS THROUGH THE NIGHT. EXPECT SHOWERS TO BE MORE ISOLATED ACROSS THE SOUTH. RATHER MILD TONIGHT WITH MIN TEMPS NO LOWER THAN THE MID 60S ACROSS THE SOUTH...TRENDING TO THE UPPER 50S/NEAR 60 SOUTH. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... AS OF 330 AM MONDAY... TUESDAY AND TUESDAY NIGHT...ACTIVE WEATHER PATTERN APPEARS LIKELY ACROSS CENTRAL NC WITH A CHANCE FOR MORE THAN ONE ROUND OF STRONG TO SEVERE STORMS. THE DEEP LOW PRESSURE SYSTEM OVER THE CENTRAL PLAINS/MID MS VALLEY WILL REMAIN NEARLY STATIONARY THIS PERIOD. A SERIES OF UPPER LEVEL DISTURBANCES WILL ROTATE AROUND THIS LOW SIMILAR TO SPOKES AROUND TEH CENTER OF A WHEEL. AS A DISTURBANCE CROSSES CENTRAL NC AND INTERACTS WITH THE WARM MOIST UNSTABLE AIR MASS IN PLACE...EXPECT SCATTERED TO NUMEROUS SHOWERS AND STORMS TO OCCUR. BASED ON MODEL TIMING 9WHICH WILL LIKELY CHANGE OR ADJUST IN LATER MODEL RUNS)...APPEARS FIRST ROUND OF SHOWERS AND STORMS WILL CROSS THE REGION TUESDAY AFTERNOON WITH ANOTHER ROUND LATE TUESDAY NIGHT. WIND PROFILES TUESDAY AFTERNOON ARE SUPPORTIVE OF STRONG UPDRAFTS WITH LOW LEVEL HELICITY VALUES IN THE 150-300 M2/S2 RANGE LATE TUESDAY INTO TUESDAY NIGHT. IN ADDITION...STRONG LIFT EXPECTED THROUGH TEH COLUMN AS CENTRAL NC WILL BE IN THE RIGHT ENTRANCE REGION OF A 100- 110KT UPPER JET. THUS...POTENTIAL FOR A FEW SEVERE STORMS TUESDAY AFTERNOON AND TUESDAY NIGHT WITH A FEW TORNADOES PROBABLE. ALSO...POTENTIAL FOR STORMS TO REPEAT ACROSS THE SAME AREA. WITH PRECIP WATER VALUES 1.5-1.75 INCHES PROJECTED...THIS SUGGEST THAT THE HEAVY SHOWERS AND STORMS WILL BE CAPABLE FOR PRODUCING HEAVY RAIN...LEADING TO FLOODING IN URBANIZED AREAS (AND EVENTUALLY SOME RIVER FLOODING). MAX TEMPS TUESDAY DEPENDENT UPON WHETHER THE SFC BOUNDARY LIFTS ENTIRELY INTO VA OR LAGS ALONG OUR NORTHERN COUNTIES. APPEARS TO BE ENOUGH OF A SLY FETCH JUST ABOVE THE SFC TO PUSH THE BOUNDARY NWD SO HAVE LEANED TOWARD THE WARMER GUIDANCE FOR TUESDAY. MAX TEMPS MID 70S FAR NORTH-NW TO THE LOWER 80S SOUTH. MIN TEMPS TUESDAY NIGHT LOW 60S FAR NORTH-NW TO MID-UPPER 60S ELSEWHERE. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 305 AM MONDAY... WEDNESDAY AND WEDNESDAY NIGHT: THE DEEP MID LEVEL LOW AND SURFACE LOW ARE EXPECTED TO LINGER ACROSS THE UPPER MIDWEST AND GREAT LAKES REGION ON WEDNESDAY AND WEDNESDAY NIGHT WITH THE SYSTEM QUITE WRAPPED UP AND OCCLUDED. THIS WILL RESULT IN STRONG SOUTH- SOUTHWESTERLY MID LEVEL FLOW ACROSS OUR REGION ALONG WITH A SLOW APPROACHING COLD FRONT. EXPECT THE HEAVIEST AND MORE WIDESPREAD PRECIP WILL BE ACROSS WESTERN PORTIONS OF THE AREA ON WEDNESDAY. THIS MAY LEAD TO A DECENT DIFFERENTIAL HEATING BOUNDARY SETTING UP ACROSS THE REGION. GIVEN DEEP LAYER SHEAR VALUES ARE EXPECTED TO BE AROUND 35 TO 50 KTS WEDNESDAY AFTERNOON INTO THE EVENING... WITH THE POTENTIAL FOR UPWARDS OF 1000 TO 2000 J/KG OF MLCAPE FOR LOCATIONS THAT WARM UP NICELY AND SEE A BIT LESS RAIN... EXPECT WE WILL HAVE A THREAT FOR SEVERE STORMS. IF WE INDEED SEE A BOUNDARY SET UP OR LINGERING BOUNDARY FROM EARLIER THEN WE COULD SEE AN INCREASE RISK FOR TORNADOES... AS 0-1 KM SRH VALUES ARE EXPECTED TO BE IN THE 150 TO 400 M2/S2 RANGE WITH RIGHT LOOPING HODOGRAPHS. GIVEN THE IMPRESSIVE DEEP LAYER SHEAR AND POSSIBLE MODERATE INSTABILITY... SUPERCELLS WILL BE POSSIBLE... WITH DAMAGING WIND AND LARGE HAIL AS WELL. IN ADDITION... WITH PW VALUES EXPECTED TO BE AROUND 1.5 INCHES (WELL ABOVE NORMAL FOR THIS TIME OF YEAR) EXPECT THE SHOWERS AND STORMS WILL PRODUCE HEAVY RAIN. THIS COUPLED WITH THE SLOW MOVING FRONT WILL POSE A RISK FOR FLASH FLOODING AND RIVER FLOODING... ESPECIALLY ACROSS THE WESTERN PIEDMONT (WHERE SEVERAL DAYS WORTH OF MODERATE TO HEAVY RAIN MAY LEAD TO 3 TO 4+ INCHES OF RAINFALL). THE MAIN AXIS OF SHOWERS AND STORMS WILL BEGIN TO SLOWLY SHIFT EASTWARD BY EARLY THURSDAY MORNING AS THE SURFACE COLD FRONT BEGINS TO PUSH THROUGH THE AREA... WITH THE MAIN AREAS OF SHOWERS AND STORMS FROM GENERALLY RALEIGH EASTWARD BY MIDNIGHT THURSDAY. TEMPS ON WEDNESDAY WILL BE TRICKY AND DRIVEN BY CLOUDS AND PRECIP. FOR NOW WILL SHOW HIGHS IN THE WEST (WHERE THE MOST RAIN IS EXPECTED) IN AROUND THE MID 70S (CLOSER TO THE COOL SIDE OF GUIDANCE) TO THE LOWER 80S SE. LOWS THURSDAY MORNING SHOULD REMAIN MILD WITH AT LEAST CONTINUED LINGERING LOW LEVEL CLOUD COVER. THUS... WILL GO WITH LOWS IN THE LOWER 60S WEST TO UPPER 60S EAST. THURSDAY THROUGH SUNDAY: THE COLD FRONT WILL SLOWLY MOVE ACROSS CENTRAL NC WEDNESDAY NIGHT/THURSDAY MORNING... WITH A FINAL SECONDARY PUSH NOT COMING THROUGH UNTIL THURSDAY NIGHT/FRIDAY MORNING. HOWEVER... WITH MID LEVEL DRY AIR FILTERING INTO THE WESTERN/NORTHWESTERN HALF OF THE CWA ON THURSDAY EXPECT WE WILL BEGIN TO DRY OUT A BIT IN PIEDMONT ON THURSDAY INTO THURSDAY NIGHT. GIVEN THE MID LEVEL TROUGH AXIS IS EXPECTED TO REMAIN TO OUR WEST UNTIL LATE SATURDAY/SATURDAY NIGHT WITH THE SURFACE FRONT EXPECTED TO LINGER NEAR THE COAST THROUGH SATURDAY MORNING... EXPECT WE COULD SEE SOME MORE SHOWERS AND EVEN SOME STORMS... WITH THE HIGHEST PROBABILITIES ACROSS OUR FAR EAST/SOUTHEASTERN AREAS. DRY WEATHER IS EXPECTED TO RETURN FOR SUNDAY. EXPECT HIGH TEMPS WILL BE IN THE 70S TO NEAR 80 EAST ON THURSDAY... WITH HIGH TEMPS GENERALLY AROUND 70 TO THE MID 70S FOR FRIDAY THROUGH SUNDAY. LOW TEMPS WILL BE IN THE 40S AND 50S FOR THIS TIME FRAME. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AS OF 140 AM MONDAY... VFR CONDITIONS EXPECTED TO LINGER THROUGH THE OVERNIGHT INTO EARLY THIS MORNING AS LOW STRATUS HAS BEEN SLOW TO DEVELOP NE OF OUR REGION. WILL CONTINUE TO MONITOR BUT THE GFS MODEL MAY BE OVERDONE IN ITS DEPICTION OF LOW CLOUDS (MVFR/IFR CEILINGS) OVER A LARGE PART OF CENTRAL NC THROUGH 11Z. THE APPROACH OF AN UPPER LEVEL DISTURBANCE FROM THE SW AND A STALLED SURFACE BOUNDARY OVER CENTRAL NC WILL CAUSE AREAS OF SHOWERS TO DEVELOP BY 13Z IN THE WESTERN AND SOUTHERN PIEDMONT...LIFTING NE INTO THE COASTAL PLAIN AND NE PIEDMONT BY MID AFTERNOON. THESE SHOWERS WILL CAUSE PERIODS OF LOW END VFR/HIGH END MVFR CEILINGS AND VISIBILITY. WHILE BEST INSTABILITY EXPECTED TO RESIDE OVER THE SOUTHERN PIEDMONT...BEST SHEAR FOR SUSTAINED UPDRAFTS WILL BE LOCATED FARTHER NORTH NEAR THE VA BORDER. STILL A SLIGHT-SMALL CHANCE FOR A FEW THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL NC BUT CONFIDENCE OF THUNDER OCCURRING WITHIN 10 SM OF A TAF SITE LOW AT THIS TIME. THUS WILL REFRAIN FROM MENTIONING THUNDER IN THE TAF SITES WITH THE 06Z TAF PACKAGE. A PERIOD OF UNSETTLED WEATHER IS ANTICIPATED THROUGH EARLY THURSDAY AS A DEEP LOW PRESSURE SYSTEM TO OUR WEST EDGES SLOWLY EAST THROUGH MID WEEK. THIS WEATHER SYSTEM WILL SPREAD AREAS OF SHOWERS AND THUNDERSTORMS (ASSOCIATED MVFR-IFR CONDITIONS) ACROSS CENTRAL NC TUESDAY THROUGH EARLY THURSDAY. STRONG TO SEVERE STORMS APPEAR HIGHLY PROBABLE TUESDAY AFTERNOON THROUGH WEDNESDAY NIGHT. IMPROVING AVIATION CONDITIONS ANTICIPATED BY LATE IN THE WEEK. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...WSS/SMITH SHORT TERM...WSS LONG TERM...BSD AVIATION...WSS
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
636 AM CDT MON APR 28 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 344 AM CDT MON APR 28 2014 CURRENT WATER VAPOR IMAGERY SHOWS THE LOW IN THE MID LEVELS OF THE ATMOSPHERE SPINNING AWAY RIGHT IN THE MIDDLE OF NEBRASKA...WITH THE WELL ADVERTISED DRY SLOT ALOFT NOSING UP IN FRONT OF IT AND ENCOMPASSING MUCH OF OUR FORECAST AREA. THE MOST PRONOUNCED DRYING ALOFT IS ALONG THE I 29 CORRIDOR CURRENTLY. MODEL CONSENSUS IS GOOD IN PROGGING THE LOW SLOWLY EASTWARD TOWARD SOUTHEAST IA BY VERY LATE TONIGHT. THE SURFACE LOW FOLLOWS SUIT...AND IT LOOKS LIKE OUR ENTIRE FORECAST AREA WILL BE PLACED NORTH OF THE WARM FRONT THROUGH TODAY AND TONIGHT. THE BEST CHANCES FOR WIDESPREAD BENEFICIAL RAINFALL TODAY WILL BE BEHIND THE INVERTED TROUGH WHICH WILL BE CONFINED TO OUR FAR WESTERN ZONES APPROACHING CENTRAL SD. THE REST OF OUR AREA WILL SEE LESS NUMEROUS SHOWERS AND RAINFALL. BUT THERE IS ENOUGH ELEVATED INSTABILITY TO POP A THUNDERSTORM OR TWO ALMOST AT ANYTIME THROUGHOUT THE ENTIRE DAY...ESPECIALLY WHEN A MICROSCALE AREA OF WARM AIR ADVECTION DECIDES TO MOVE NORTHWARD WHICH THE MODELS CANNOT HANDLE VERY WELL ON THAT SCALE. INTERESTINGLY...BOTH THE GFS AND GEM PAINT A BROAD STRIPE OF DECENT QPF THIS AFTERNOON JUST NORTH OF THE WARM FRONT FROM SIOUX CITY TO STORM LAKE. IN ADDITION...THE PAST FEW RUNS OF THE HRRR ARE ALSO SHOWING THE POSSIBILITY OF DECENT CONVECTION IN THOSE AREAS AGAIN DUE TO THE PROXIMITY OF THE WARM FRONT JUST TO THE SOUTH. AT THIS TIME...IT LOOKS TOO STABLE FOR MUCH IN THE WAY OF SEVERE WEATHER...AND ALSO THE WIND SHEAR IS NOT REAL GREAT FROM SIOUX CITY TO STORM LAKE AS THE ENTIRE LOWEST 3 KILOMETERS HAS A WIND DIRECTION OUT OF THE EAST. ONE THING TO WATCH FOR HOWEVER IS IF A ROGUE SEVERE STORM WHICH BLOWS UP FURTHER TO THE SOUTHEAST NUDGES INTO THOSE AREAS BEFORE WEAKENING. TO THE NORTH...KEPT THE COVERAGE OF POPS IN THE SCATTERED CATEGORY THIS AFTERNOON ALONG THE I 29 CORRIDOR WHERE THE DRY SLOT ALOFT HAS THE MOST IMPACT. BUT OTHER AREAS MAY START TO FILL IN MORE WITH RAINFALL IN OUR FAR EAST AND INTO THE JAMES RIVER VALLEY FROM THE WEST AS MOISTURE PROGS SATURATE UP BETTER ALOFT. FEEL THERE IS NO NEED FOR A WIND ADVISORY TODAY AS SOUNDINGS ONLY MIX TO ABOUT 925-900MB AREA WIDE. WINDS IN THAT LAYER ARE STOUT... AVERAGING 30 TO 35 KNOTS...BUT USUALLY IT TAKES A LITTLE MORE THAN THAT TO WARRANT A WIND ADVISORY IN OUR AREA...CLOSER TO 40 KNOTS. HOWEVER TONIGHT ON THE BACK SIDE OF THE LOW...OUR FAR SOUTHWEST ZONES MAY GET CLOSE TO ADVISORY CRITERIA AFTER MIDNIGHT. MUCH OF OUR FORECAST AREA TONIGHT IS WELL PLACED IN THE UPPER LEFT QUADRANT OF THE LOW TRACK TO RECEIVE PRECIP. THERE IS EVEN SOME WEAK TROWALING IN THE 290-295K LAYER NUDGING INTO OUR AREA FROM THE EAST...AND SATURATION LOOKS TO BE IN NO SHORT SUPPLY FROM THE SURFACE TO AROUND 500MB. IN THE EVENING...AGAIN THE I 29 CORRIDOR MAY NOT RECEIVE MUCH RAIN...BUT PRECIP WILL FILL INTO THAT AREA OVERNIGHT. CONCERNING TEMPERATURES...WITH A FEW BREAKS POSSIBLE NEAR THE WARM FRONT... AREAS FROM YANKTON TO STORM LAKE AND SOUTHWARD SHOULD HIT 60 TO 65...PROGRESSIVELY COOLING OFF HEADING NORTHWARD. TONIGHT IS TRICKY...AND HAD TO ADD IN A SNOW MIX TO OUR NORTHERN AND WESTERN ZONES AS SURFACE TEMPERATURES COOL INTO THE MID 30S IN THOSE AREAS COUPLED WITH SUB ZERO 850MB TEMPERATURES. USED THE MODEL CONSENSUS 850MB -2 DEGREE C AND 925MB ZERO DEGREE C ISOTHERMS FOR THE RAIN AND SNOW LINES...COUPLED WITH TEMPERATURES NEAR 35. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 344 AM CDT MON APR 28 2014 TUESDAY WILL START FAIRLY RAINY OVER THE AREA...THOUGH AMOUNTS SHOULD BE LESS THAN A QUARTER INCH FOR THE DAY. DRYING WILL BEGIN FROM THE NORTH/NORTHEAST DURING THE AFTERNOON OVER THE WESTERN PART OF THE FORECAST AREA AS SOME SUBSIDENCE SPREADS IN FROM THE NORTH/ NORTHEAST BETWEEN LOBES ROTATING AROUND THE UPPER LOW TO THE EAST. FOR NOW WILL KEEP SOME VERY MINIMAL POPS IN THE WEST FOR TUESDAY NIGHT...WHILE ONLY SHAVING POPS TO LOW LIKELIES ALONG OUR EASTERN EDGE IN MN AND IA. FOR NOW AM GOING FOR ALL OF THIS PRECIPITATION TO BE LIGHT RAIN EXCEPT MAYBE SOME MODERATE RAIN LINGERING TUESDAY MORNING IN THE EAST...MAYBE WITH A BIT OF WET SNOW MIXED IN WEST AND NORTH EARLY MORNING BUT NO ACCUMULATION. FOR TUESDAY NIGHT...THOUGH TEMPERATURES ALOFT WILL BE MARGINAL FOR A LITTLE MIXED SNOW AGAIN... THERE MAY BE NO PRECIPITATION AT ALL IN THE WEST WHICH WOULD HAVE THE BETTER SHOT AT SOME SNOW. SURFACE AND NEAR SURFACE TEMPERATURES WILL LIKELY BE A BIT TOO WARM WITH THE LIGHTER NATURE OF PRECIPITATION...IF THERE IS ANY AROUND IN THE FIRST PLACE...AND DYNAMIC COOLING WILL BE NIL. TO THE EAST...THE DEEPER MOIST AIR SHOULD PRECLUDE ENOUGH COOLING TO GET SNOW TO THE SURFACE...AND EVEN THERE THE PRECIPITATION SHOULD BE PRETTY LIGHT. TEMPERATURES WILL NOT BE SHOWING A LOT OF SPREAD WITH 40S HIGHS AND 30S LOWS. IT WILL STILL BE WINDY TUESDAY BUT EXPECT WINDS WILL STAY BELOW ADVISORY CRITERIA. WEDNESDAY WILL BRING THE NEXT LOBE ROTATING OVER THE AREA AND A RESURGENCE OF LIGHT RAIN WEST/SOUTHWESTWARD AGAIN. TEMPERATURES AGAIN WILL CLIMB INTO THE 40S AND IT WILL BE WINDY AGAIN. IT COULD EVEN BE SLIGHTLY WINDIER THAN TUESDAY WITH THE LOBE PASSING OVER THE AREA. THURSDAY WILL BRING THE SYSTEM STARTING TO MOVE SLOWLY EAST OF THE AREA AND WILL KEEP LIGHT RAIN POPS IN THE CHANCE CATEGORY. WEDNESDAY NIGHT LOWS SHOULD BE IN THE 30S AGAIN...THOUGH IT MAY BE A DEGREE OR TWO LESS COOL THERE WITH MODELS HINTING AT VERY SLIGHT LOW LEVEL WARMING. WITH LESSER PRECIPITATION COVERAGE...THURSDAY DAY TEMPERATURES ARE EXPECTED TO BE A TAD LESS COOL...UPPER 40S TO LOWER 50S FOR HIGHS. THIS PROCESS WILL CONTINUE ON FRIDAY...REMEMBER THE SLOWNESS OF THIS SYSTEM...BUT POPS WILL BE PRETTY LOW WITH PRECIPITATION CONFINED MAINLY TO EAST OF FSD. 50 TO 55 LOOKS RIGHT FOR HIGHS FRIDAY. THE WEEKEND SHOULD BE A LITTLE WARMER YET...BUT STILL BELOW NORMAL...AHEAD OF A CANADIAN WAVE APPROACHING IN NORTHWEST FLOW BEHIND THE CURRENT SYSTEM. WILL GO WITH THE EXTENDED GUIDANCE GRIDS OF SHOWER CHANCE PEAKING ABOUT SATURDAY NIGHT. THIS SEEMS TO BE THE BEST PLAN FOR NOW ON EITHER THE GFS OR EC SOLUTION. THE EC HAS STRONGER RIDGING BETWEEN SYSTEMS THAN THE GFS AND WOULD BRING TEMPERATURES A LITTLE CLOSER TO NORMAL FOR THE WEEKEND...BUT THE LIGHT SHOWER THREAT IS STILL THERE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 632 AM CDT MON APR 28 2014 IT APPEARS WIDESPREAD LIFR TO IFR CONDITIONS WILL BE PERSISTENT ACROSS THE SIOUX FALLS FORECAST AREA BOTH TODAY AND TONIGHT. IN ADDITION AS STRONG LOW PRESSURE NUDGES VERY SLOWLY EASTWARD... WINDS WILL OCCASIONALLY GUST AROUND 25 TO 30 KNOTS AT TIMES BOTH TODAY AND TONIGHT...AS THE OVERALL FLOW BENDS FROM THE EAST TO THE NORTH TONIGHT. IN THE NEAR TERM...KSUX IS THE MOST CHALLENGING SITE IN THAT CLEARING WITH VFR CONDITIONS IS NOT TOO FAR AWAY TO THEIR SOUTHWEST. HOWEVER...THE WIND PROFILE ALL THE WAY FROM THE SURFACE TO 500MB IS DECIDEDLY EASTWARD ALL DAY TODAY. SO THEREFORE IT APPEARS THAT THE CLEARING MAY NEVER MAKE IT INTO KSUX...SO TOOK THE PESSIMISTIC ROUTE FOR THEM. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...MJ LONG TERM... AVIATION...MJ
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1058 AM CDT MON APR 28 2014 .DISCUSSION... ADDED CLIMATE SECTION. && .CLIMATE... HIGH TEMPERATURES TODAY WILL LIKELY REACH 90 DEGREES. THE LAST TIME THE CITY OF HOUSTON (KIAH) REACH 90 DEGREES WAS OCTOBER 5TH OF LAST YEAR (93). THE LAST TIME COLLEGE STATION (CLL) REACHED 90 DEGREES WAS OCTOBER 1ST OF LAST YEAR (91). HERE ARE THE RECORDS FOR THE THREE FIRST ORDER CLIMATE SITES FOR TODAY WITH THEIR FORECASTED HIGHS TO THE FAR RIGHT: CLL (COLLEGE STATION) : 94 (1987) || 91 IAH (CITY OF HOUSTON) : 95 (1987) || 92 GLS (CITY OF GALVESTON):87 (1987) || 84 && .PREV DISCUSSION... /ISSUED 1038 AM CDT MON APR 28 2014/ UPDATE... SEE DISCUSSION FOR MORNING UPDATE. DISCUSSION... PRECIP HAS COME TO AN END ACROSS MOST OF THE AREA THIS MORNING AS DRIER AIR WORKS ITS WAY IN FROM THE WEST. HRRR SHOWS A CELL OR TWO TRYING TO DEVELOP IN CHAMBERS COUNTY AS THE DRY LINE STALLS NEAR THE COAST THIS AFTERNOON. THE TORNADO WATCH FOR THE AREA WILL BE ALLOWED TO CONTINUE UNTIL 17Z. BEHIND THE DRY LINE LIGHT NORTHWEST WINDS... LITTLE CLOUD COVER AND DRY AIR WILL HELP THE AREA TO QUICKLY HEAT UP. CURRENT AMDAR SOUNDING FOR HOUSTON SUPPORTS TEMPERATURES IN THE LOWER 90S. MOST OF THE AREA IS ALREADY AT OR SLIGHTLY ABOVE 80. 90 DEGREES LOOKS POSSIBLE FOR MOST SITES ACROSS THE AREA (MINUS NORTHEAST COUNTIES AND AT THE COAST). NUDGED MAX TEMPERATURE GRID UP SLIGHTLY FOR THIS AFTERNOON. ALSO TRIMMED POPS BACK AS THE CHANCE FOR CONVECTION APPEARS TO BE COMING TO AN END. NO OTHER CHANGES TO GRIDS AT THIS TIME. 23 PREV DISCUSSION... /ISSUED 421 AM CDT MON APR 28 2014/ DISCUSSION... BKN LINE OF TSTMS HAS DEVELOPED SEVERAL MILES AHEAD OF THE SFC TROF EXTENDING FROM NORTHEAST TEXAS AND INTO NORTHERN PARTS OF SE TX. NO REPORTS OF SEVERE WX IN OUR CWA JUST YET BUT WOULD BE SURPRISED IF NO HAIL IS EVENTUALLY REPORTED FROM HOUSTON COUNTY W/ THOSE STORMS. THINK MAJORITY OF THESE WILL REMAIN ELEVATED SO HAIL WILL BE PRIMARY THREAT. HRRR MODEL HAS BEEN DOING A GOOD JOB IN THE PAST 24 HOURS AND HAS CONTINUED DOING WELL WITH CURRENT TRENDS. IT SHOWS THIS PRECIPITATION MAKING ITS WAY SEWD TOWARD THE UPPER TX COAST IN THE NEXT 6 HOURS SO HAVE BUMPED POPS UP ACROSS A GOOD PART OF THE AREA. SFC TROF WILL MAKE IT ALMOST TO THE COAST BY LATE MORNING ENDING PRECIP CHANCES AND BRINGING A DRY AIRMASS INTO MOST OF THE AREA. THIS DRY AIRMASS AND SUNSHINE SHOULD ALLOW FOR A RAPID WARM UP ACROSS THE AREA THIS AFTN. SFC TROF MOVES BACK NORTH LATE TONIGHT AND BECOME OVERTAKEN BY THE PRIMARY COLD FRONT THAT WILL PUSH ACROSS THE AREA DURING THE DAY TUE. CURRENT GUIDANCE COMING IN A TOUCH COOLER THAN EARLIER FCSTS SO NUDGED HIGHS/LOWS DOWN A BIT FOR THE NEXT SEVERAL DAYS. THRU LATE WEEK WE SHOULD STILL BE IN A WSW FLOW ALOFT UNDER BROAD UPPER TROF SITUATED ACROSS CNTL PARTS OF THE COUNTRY. MAY SEE PERIODS OF HIGH CLOUDINESS BUT MEAGER LLVL MOISTURE LEVELS SHOULD KEEP THINGS MOSTLY DRY. SHOULD TRANSITION TO A DRY NW FLOW LATE IN THE WEEK AND EARLY WEEKEND AS UPPER TROF MOVES EWD. OTHERWISE...LOOKS QUITE DRY THRU THE 1ST WEEK OF MAY. 47 MARINE... WILL EXTEND THE CURRENT ADVISORIES OVER THE COASTAL WATERS/CAUTION FLAGS ON THE BAYS INTO THE MID MORNING HRS BASED ON CURRENT TRENDS. GRADIENT STILL EXPECTED TO WEAKEN BY THE AFTN WITH THE APPROACH OF THE PACIFIC FRONT FROM THE WEST. AS THIS BOUNDARY STALLS ALONG THE COASTLINE...WINDS SHOULD REMAIN OUT OF THE SW/S THROUGH THE DAY/TO- NIGHT. THE MAIN PUSH OF STRONG NORTH WINDS STILL FCST FOR TUE AFTN WITH THE CANADIAN COLD FRONT. BEHIND THIS FRONT...CAUTION/ADVISORY FLAGS WILL BE LIKELY FROM TUE NIGHT INTO WEDS NIGHT. THIS OFFSHORE FLOW COULD EXTEND THROUGH THE END OF THE WEEK. 41 AVIATION... HAVING TO KEEP AN EYE ON DEVELOPMENT OUT TO OUR W/NW THRU THE MORN- ING HOURS. PROBABLY CANNOT AVOID THE MENTION OF THUNDER IN THE NRN HALF TAF SITES (CLL/UTS/CXO/IAH) THIS MORNING UNTIL THIS AFTN. THE APPROACH/PASSAGE OF THE PACIFIC FRONT (IN WHICH THIS PCPN IS FOCUS- ING ON) SHOULD BRING DRIER AIR AND VFR CONDITIONS TO THE AREA LATE THIS AFTN/TONIGHT. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 91 59 82 51 75 / 10 10 10 0 0 HOUSTON (IAH) 92 62 86 55 78 / 20 10 10 0 0 GALVESTON (GLS) 84 71 84 62 77 / 20 10 20 0 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 2 PM CDT THIS AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION/CLIMATE...23
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1038 AM CDT MON APR 28 2014 .UPDATE... SEE DISCUSSION FOR MORNING UPDATE. && .DISCUSSION... PRECIP HAS COME TO AN END ACROSS MOST OF THE AREA THIS MORNING AS DRIER AIR WORKS ITS WAY IN FROM THE WEST. HRRR SHOWS A CELL OR TWO TRYING TO DEVELOP IN CHAMBERS COUNTY AS THE DRY LINE STALLS NEAR THE COAST THIS AFTERNOON. THE TORNADO WATCH FOR THE AREA WILL BE ALLOWED TO CONTINUE UNTIL 17Z. BEHIND THE DRY LINE LIGHT NORTHWEST WINDS... LITTLE CLOUD COVER AND DRY AIR WILL HELP THE AREA TO QUICKLY HEAT UP. CURRENT AMDAR SOUNDING FOR HOUSTON SUPPORTS TEMPERATURES IN THE LOWER 90S. MOST OF THE AREA IS ALREADY AT OR SLIGHTLY ABOVE 80. 90 DEGREES LOOKS POSSIBLE FOR MOST SITES ACROSS THE AREA (MINUS NORTHEAST COUNTIES AND AT THE COAST). NUDGED MAX TEMPERATURE GRID UP SLIGHTLY FOR THIS AFTERNOON. ALSO TRIMMED POPS BACK AS THE CHANCE FOR CONVECTION APPEARS TO BE COMING TO AN END. NO OTHER CHANGES TO GRIDS AT THIS TIME. 23 && .PREV DISCUSSION... /ISSUED 421 AM CDT MON APR 28 2014/ DISCUSSION... BKN LINE OF TSTMS HAS DEVELOPED SEVERAL MILES AHEAD OF THE SFC TROF EXTENDING FROM NORTHEAST TEXAS AND INTO NORTHERN PARTS OF SE TX. NO REPORTS OF SEVERE WX IN OUR CWA JUST YET BUT WOULD BE SURPRISED IF NO HAIL IS EVENTUALLY REPORTED FROM HOUSTON COUNTY W/ THOSE STORMS. THINK MAJORITY OF THESE WILL REMAIN ELEVATED SO HAIL WILL BE PRIMARY THREAT. HRRR MODEL HAS BEEN DOING A GOOD JOB IN THE PAST 24 HOURS AND HAS CONTINUED DOING WELL WITH CURRENT TRENDS. IT SHOWS THIS PRECIPITATION MAKING ITS WAY SEWD TOWARD THE UPPER TX COAST IN THE NEXT 6 HOURS SO HAVE BUMPED POPS UP ACROSS A GOOD PART OF THE AREA. SFC TROF WILL MAKE IT ALMOST TO THE COAST BY LATE MORNING ENDING PRECIP CHANCES AND BRINGING A DRY AIRMASS INTO MOST OF THE AREA. THIS DRY AIRMASS AND SUNSHINE SHOULD ALLOW FOR A RAPID WARM UP ACROSS THE AREA THIS AFTN. SFC TROF MOVES BACK NORTH LATE TONIGHT AND BECOME OVERTAKEN BY THE PRIMARY COLD FRONT THAT WILL PUSH ACROSS THE AREA DURING THE DAY TUE. CURRENT GUIDANCE COMING IN A TOUCH COOLER THAN EARLIER FCSTS SO NUDGED HIGHS/LOWS DOWN A BIT FOR THE NEXT SEVERAL DAYS. THRU LATE WEEK WE SHOULD STILL BE IN A WSW FLOW ALOFT UNDER BROAD UPPER TROF SITUATED ACROSS CNTL PARTS OF THE COUNTRY. MAY SEE PERIODS OF HIGH CLOUDINESS BUT MEAGER LLVL MOISTURE LEVELS SHOULD KEEP THINGS MOSTLY DRY. SHOULD TRANSITION TO A DRY NW FLOW LATE IN THE WEEK AND EARLY WEEKEND AS UPPER TROF MOVES EWD. OTHERWISE...LOOKS QUITE DRY THRU THE 1ST WEEK OF MAY. 47 MARINE... WILL EXTEND THE CURRENT ADVISORIES OVER THE COASTAL WATERS/CAUTION FLAGS ON THE BAYS INTO THE MID MORNING HRS BASED ON CURRENT TRENDS. GRADIENT STILL EXPECTED TO WEAKEN BY THE AFTN WITH THE APPROACH OF THE PACIFIC FRONT FROM THE WEST. AS THIS BOUNDARY STALLS ALONG THE COASTLINE...WINDS SHOULD REMAIN OUT OF THE SW/S THROUGH THE DAY/TO- NIGHT. THE MAIN PUSH OF STRONG NORTH WINDS STILL FCST FOR TUE AFTN WITH THE CANADIAN COLD FRONT. BEHIND THIS FRONT...CAUTION/ADVISORY FLAGS WILL BE LIKELY FROM TUE NIGHT INTO WEDS NIGHT. THIS OFFSHORE FLOW COULD EXTEND THROUGH THE END OF THE WEEK. 41 AVIATION... HAVING TO KEEP AN EYE ON DEVELOPMENT OUT TO OUR W/NW THRU THE MORN- ING HOURS. PROBABLY CANNOT AVOID THE MENTION OF THUNDER IN THE NRN HALF TAF SITES (CLL/UTS/CXO/IAH) THIS MORNING UNTIL THIS AFTN. THE APPROACH/PASSAGE OF THE PACIFIC FRONT (IN WHICH THIS PCPN IS FOCUS- ING ON) SHOULD BRING DRIER AIR AND VFR CONDITIONS TO THE AREA LATE THIS AFTN/TONIGHT. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 91 59 82 51 75 / 10 10 10 0 0 HOUSTON (IAH) 92 62 86 55 78 / 20 10 10 0 0 GALVESTON (GLS) 84 71 84 62 77 / 20 10 20 0 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 2 PM CDT THIS AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...23
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
635 AM CDT MON APR 28 2014 .DISCUSSION...SEE 12Z AVIATION DISCUSSION. && .AVIATION...LOW CIGS/VSBYS RAPIDLY LIFTING AS WINDS HAVE SHIFTED. WILL LIKELY JUST HAVE SOME TEMPO CONDITIONS ENDING BY NO LATER THAN 14Z EASTERN TERMINALS. SHOULD MAINLY HAVE N-NW WINDS ESPECIALLY BY 14Z WITH MAINLY CLEAR SKIES. SEA-BREEZE COMES IN AGAIN LATE THIS AFTERNOON AND SHIFT WINDS SOUTHERLY STARTING ABOUT 20Z AT KCRP AND SPREADING WESTWARD. WINDS DIMINISH TONIGHT AND MAINLY BECOME LIGHT AND VARIABLE OVERNIGHT. COULD HAVE SOME GROUND FOG KCRP AND KVCT TOWARD END OF TAF PERIOD AS LIGHT WINDS AND CLEAR SKIES CREATE FOG. && .PREV DISCUSSION... /ISSUED 326 AM CDT MON APR 28 2014/ SHORT TERM (TODAY THROUGH TUESDAY)...WARM AND DRY TODAY AND TUESDAY TOO (MOST AREAS)...AS COLD AIR IS EXPECTED TO LAG BEHIND THE FRONTAL BOUNDARY ON TUESDAY. LOOKS LIKE ANOTHER HOT DAY...BUT NOT AS HOT AS YESTERDAY AT LEAST OUT TO THE WEST AS BOUNDARY LAYER TEMPERATURES ARE PROGGED TO BE SEVERAL DEGREES COOLER (SO IF THAT HAPPENS IT SHOULD BE COOLER). 4KM RUC IS SHOWING TEMPERATURES TOPPING 100 DEGREE BARRIER OVER THE SOUTHERN AREAS...AND WILL GO 101/102 OVER THE SOUTHWESTERN AREAS. OTHERWISE...MORNING LOW CLOUDS OVER THE EAST WILL QUICKLY LIFT AND SHOULD SEE LOTS OF SUN WITH NORTHWEST WINDS AS DRY LINE MOVES FARTHER EAST THAN YESTERDAY. LOW LEVEL MOISTURE IS TOO SCOURED OUT FOR ANY MENTION OF RAIN (EVEN OFFSHORE) SO HAVE REMOVED (4KM MODELS KEEP THINGS DRY TOO). FOR TONIGHT...ONLY NAM IS BRINGING COOLER AIR MUCH FASTER THAN GFS/ECMWF (ALTHOUGH CANADIAN IS COOL TOO...AS USUAL). AM GOING TO PREFER TO GO MORE ON THE WARM SIDE TONIGHT ALTHOUGH IF WINDS ARE TOO LIGHT AND SURFACE MOISTURE IS TOO LOW...WE COULD REALLY BOTTOM OUT (GIVEN WARM DAY EXPECTED TODAY WILL PREFER TO STAY ON THE WARM SIDE THOUGH). COOLER AGAIN ON TUESDAY BUT STILL WARMER THAN NORMAL WITH COLD AIR LAGGING ON FRONT. MAY SEE A FEW 80S IN THE VICTORIA AREA. MOISTURE AGAIN TOO LIMITED FOR PRECIPITATION. MARINE (TODAY THROUGH TUESDAY)...HAVE EXTENDED THE SCA TIL 4 AM FOR THE BAYS/WATERWAYS...AND LONGER FOR THE GULF WATERS. MAY NEED TO EXTEND AGAIN AT THE LAST MINUTE IF WINDS STAY UP AGAIN. WINDS HAVE STAYED UP LONGER THAN EXPECTED WITH GUSTS OVER 30 KNOTS AT KNGP. 4KM RUC HAS WINDS CRANKING TIL 12Z OR SO...BUT THIS IS NORMALLY ON THE HIGH SIDE (BUT STILL DOING BETTER THAN NAM12 OR OTHER MODELS). WINDS DO DECREASE BY SUNRISE...BUT SEAS STAY UP. THUS...THE GULF WATER SCA WILL MAINLY BE FOR HIGH SEAS MONDAY...WITH SCA CONDITIONS ENDING AROUND NOON. VISIBILITIES OVER THE MARINE AREAS ARE BETWEEN 1 AND 3 MILES...AND THAT SHOULD CLEAR UP LATER THIS MORNING. MORE FOG TONIGHT BUT THAT SHOULD BE OVER THE OFFSHORE WATERS (IF THAT)...AS DRIER AIR DOES GET INTO THE NEARSHORE WATERS. COULD NOT RULE OUT A ROGUE SHOWER NEAR MATAGORDA ISLAND BUT THAT WILL BE VERY BRIEF AND UNLIKELY TO HAPPEN (SO NOT IN FORECAST). FIRE WEATHER (TODAY THROUGH TUESDAY)...FIRE WEATHER PROCEDURE IS SHOWING ELEVATED CONDITIONS/ISOLATED CRITICAL OVER MUCH OF THE AREA ON TUESDAY. FUEL DRYNESS FORECAST MAP IS SHOWING MOST AREAS IN NORMAL MOISTURE..WITH ONLY A PART OF THE NORTHERN COASTAL BEND (LIVE OAK AND PORTIONS OF BEE AND MCMULLEN COUNTIES) IN DRY FUELS. SINCE THESE COUNTIES ARE FORECAST TO BE IN ELEVATED CONDITIONS ON TUESDAY...NO NEED FOR FIRE WEATHER WATCH OR RED FLAG WARNING. DAY SHIFT OR NEXT MID SHIFT CAN RE-EVALUATE...ESPECIALLY IF FUEL DRYNESS MAP CHANGES THE NEXT DAY. LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...PERIOD BEGINS WITH COOLER TEMPERATURES AND DRY CONDITION IN WAKE OF TUESDAY/S/S FROPA. BROAD LONGWAVE TROUGH CENTERED OVER THE FAR NORTH CENTRAL STATES WILL KEEP FAIRLY ZONAL FLOW OVER SOUTH TEXAS THROUGH THURSDAY. TROUGH WILL FINALLY SWING OVER THE REGION THURSDAY NIGHT INTO FRIDAY. ECMWF CONTINUES TO BE THE WETTER SOLUTION WITH THIS PASSING WHILE THE GFS/NAM STAY MOSTLY DRY OVERLAND. WHILE THERE IS THE UPPER LEVEL SUPPORT FOR PERHAPS SOME SPRINKLES AND RAIN TO DEVELOP THERE IS AN OVERALL LACK OF SUFFICIENT MOISTURE OVER MOST OF THE REGION EXCEPT IN THE OVER THE OFFSHORE WATERS THURSDAY NIGHT INTO FRIDAY MORNING. KEPT THE 20 POPS MENTION OVER THE OFFSHORE WATERS FOR NOW...BUT EVEN THIS MAY BE GOING TOO HIGH. OTHERWISE EXPECT A CONTINUED DRY FORECAST. TEMPERATURES WILL BE NICELY COOLER (BELOW AVERAGE) THROUGH THE END OF THE WEEK BEFORE RETURNING TO NORMAL ON BY THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 99 66 93 61 80 / 10 0 10 10 10 VICTORIA 93 63 88 55 81 / 10 0 10 10 10 LAREDO 104 69 98 62 86 / 0 0 10 10 10 ALICE 102 64 96 57 83 / 10 0 10 10 10 ROCKPORT 92 67 89 62 79 / 10 0 10 10 10 COTULLA 98 63 92 54 83 / 0 0 0 10 10 KINGSVILLE 102 65 97 60 81 / 10 0 10 10 10 NAVY CORPUS 90 67 87 65 79 / 10 0 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM. SMALL CRAFT ADVISORY UNTIL 11 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. && $$ GW/86...AVIATION
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
711 AM EDT MON APR 28 2014 .SYNOPSIS... A WEAK STATIONARY FRONT WILL REMAIN JUST SOUTH AND WEST OF THE REGION TODAY INTO TUESDAY. A LARGE AND COMPLEX STORM SYSTEM LOCATED OVER THE CENTRAL UNITED STATES WILL SLOWLY MOVE EAST. THIS SYSTEM WILL PROVIDE RAINFALL FOR MUCH OF THE UPCOMING WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 250 AM EDT MONDAY... WEAK BACKDOOR TYPE COLD FRONT NOW HEADING INTO THE SW PORTIONS OF THE CWA WITH A STIFF EASTERLY FLOW DEVELOPING ESPCLY EAST OF THE BLUE RIDGE WHERE BEST COOL ADVECTION WILL TAKE SHAPE THIS MORNING. INIT MID LEVEL WAVE EJECTING OUT INTO THE SHORTWAVE RIDGING ALOFT LIKELY TO HELP MOISTEN THE COLUMN EARLY ON WITH MAINLY JUST SPOTTY -RA OR SPRINKLES INTO MID MORNING PER LATEST RADAR TRENDS. MAIN SHOT AT MORE WIDESPREAD RAINFALL LOOKS TO COME FROM LATE MORNING INTO MID AFTERNOON AS ANOTHER WAVE SLIDES BY TO THE NW AND HELPS UPWARD MOTION SWING ACROSS THE NORTH UNDER A CORE OF SLIGHTLY HIGHER 85H WINDS. MOST GUIDANCE ON TRACK WITH THIS FEATURE WITH THE LATEST HRRR EXPANDING THIS AXIS EAST TO ALONG THE BLUE RIDGE AROUND MIDDAY BEFORE TAKING IT TO THE EAST DURING THE AFTERNOON ALONG THE GRADIENT OF THE THETA-E AXIS ALOFT. THUS HAVE INCLUDED SOME CHANCE POPS MAINLY WEST EARLY THIS MORNING...THEN A PERIOD OF LIKELYS FROM WEST TO EAST THROUGH LATE AFTERNOON WHEN SEE BEST OVERRUNNING. HOWEVER QPF DOESNT LOOK TOO IMPRESSIVE WITH THIS FEATURE WITH A TENTH TO A QUARTER INCH POSSIBLE WITH ANY THUNDER FAR WEST AWAY FROM THE DEVELOPING EASTERN WEDGE. HIGH TEMPS REMAIN TRICKY AS COULD SEE AREAS ACROSS THE NE ONLY RISE A FEW DEGREES WHILE JUMPING ABOVE 70 ALONG THE I-77 CORRIDOR. WENT CLOSER TO THE COLDER MET MOS ALONG/EAST OF THE BLUE RIDGE AND A BLEND OUT WEST. IMPULSE EXITS BY THIS EVENING LEAVING MOST OF THE REGION IN A STRONG WEDGE WITH ABSENCE OF MUCH LIFT WITH A BAND OF DEEPER CONVECTION APPROACHING THE MOUNTAINS FROM THE WEST LATE. HOWEVER SOUNDINGS SHOW A RATHER DEEP EAST/SE LOW LEVEL FLOW UNDER VEERING ALOFT WHICH WOULD SUPPORT AT LEAST SPOTTY -RA/DZ OUTSIDE THE FAR WEST WITH ADDED UPSLOPE LIKELY ENHANCING COVERAGE EASTERN SLOPES OF THE BLUE RIDGE. WEAKENING SHRA/TSRA HEADED IN FROM THE WEST AROUND DAYBREAK COULD REACH THE WESTERN SLOPES SO KEPT IN SOME THUNDER MENTION ON THE PERIMETER OF THE WEDGE FOR NOW OVERNIGHT. OTRW CLOUDY AND DAMP WITH PERIODS OF -RA/DZ AND PERHAPS A FEW MORE -SHRA SW AS DEEPER WARM ADVECTION SPREADS NORTH ALOFT LATE. KEPT LOWS CLOSER TO THE COOLER MET MOS AGAIN IN EXPECTING A STRONGER WEDGE IN THE WAKE OF EARLIER RAINFALL. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM EDT MONDAY... DEEP UPPER CLOSED LOW OVER IOWA AND THE UPPER RIDGE ALONG THE EAST COAST WILL MOVE EAST DURING THE PERIOD. THE MAIN LOW MOVES EAST ACROSS THE GREAT LAKES WHILE A WAVE OF LOW PRESSURE ALONG THE FRONTAL BOUNDARY WILL TRACK TOWARD THE MISSISSIPPI RIVER BY TUESDAY EVENING. PLENTY OF MOISTURE IS TRANSPORTED INTO THE REGION FROM THE ATLANTIC OCEAN AT LOWEST LEVELS AND FROM THE GULF OF MEXICO THROUGH A DEEP LAYER FARTHER ALOFT. HIGH TEMPERATURES ON TUESDAY ARE TRICKY DEPENDING SUNSHINE AND AMOUNT OF RAIN. PLAYED HIGHS TOWARDS THE COOLER ADJMET WITH VALUES FROM THE UPPER 50S ACROSS THE NORTH TO THE LOWER 70S ACROSS THE SOUTH. THE SWODY2 HAS A FEW SOUTHEAST COUNTIES IN THE SLIGHT RISK FOR SEVERE THUNDERSTORMS. APPEARS THAT THEY ARE ALLOWING THE WEDGE TO WEAKEN ON THE SOUTHERN END FOR A FEW HOURS. WITH THE STRENGHT OF THE WEDGE...GENERALLY UNDERDONE ON THE MODELS...QUESTIONS ON WHETHER THE WEDGE MIXES OUT FOR A FEW HOURS TUESDAY AFTERNOON. BEST Q-V FORCING AND UPPER DIFFLUENCE IN THE RIGHT REAR QUADRANT OF THE UPPER JET WILL BE TUESDAY NIGHT AND WEDNESDAY. PRECIPITABLE WATER VALUES RISE TO AS HIGH AS 1.6 INCHES ACROSS THE SOUTHERN AND EASTERN COUNTY WARNING AREA TUESDAY...WHICH IS AROUND TWO STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR. KEPT THE HIGHEST QPF IN THE TUESDAY NIGHT TO WEDNESDAY TIME FRAME...SIMILAR TO WPC GUIDANCE. HPC HAS PLACED EXCESSIVE RAINFALL POTENTIAL FOR DAY 2-3 ALONG AND EAST OF THE BLUE RIDGE. HOWEVER WILL HOLD OFF ON A FLOOD WATCH FOR NOW GIVEN INTERVALS OF HEAVY RAIN AND WHERE EXCESSIVE MAY OCCUR BASED ON RAINFALL THROUGH MONDAY NIGHT. THUS WILL MENTION FLOODING POTENTIAL IN THE HWO FOR TUESDAY INTO WEDNESDAY. CLOUDS MAY HOLD UP LOW TEMPERATURES TUESDAY NIGHT. PLAYED OVERNIGHT LOW TEMPERATURES FOR THE LOWER 50S IN THE NORTHERN MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT. WEDNESDAY LOOKS MORE UNSTABLE WITH LIS AROUND MINUS 5 AND CAPES POTENTIALLY EXCEEDING 2000 J/KG. INCREASED THE COVERAGE OF THUNDERSTORMS WEDNESDAY. THE SWODY3 HAS MUCH OF THE CWA IN THE SLIGHT RISK AHEAD OF THE COLD FRONT. THE MAIN THREAT WILL BE DAMAGING WINDS. HIGH TEMPERATURES ON WEDNESDAY WILL BE WARMER THAN TUESDAY WITH READINGS FROM THE UPPER 60S IN THE MOUNTAINS TO THE MID 70S IN THE PIEDMONT. TAPER POPS OFF WEDNESDAY NIGHT INTO THURSDAY. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE THE MID 40S IN THE MOUNTAINS TO AROUND 60 DEGREES IN THE PIEDMONT. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 300 PM EDT SUNDAY... ON THURSDAY...THE CLOSED UPPER LOW WILL BE OVER THE GREAT LAKES WITH THE LARGE TROF COVERING MUCH OF THE CENTRAL AND EASTERN UNITED STATES. THE PATTERN REMAINS AMPLIFIED THROUGH SATURDAY BUT THE REX BLOCK WEAKENS...THE LOW OPENS UP AND THE TROF GRADUALLY MOVES EAST BY SATURDAY. A SHORT WAVE TRACKING THROUGH THE BASE OF THE UPPER TROF WILL MOVE ACROSS THE TENNESSEE VALLEY ON SATURDAY. A STRONGER SHORT WAVE MOVES INTO THE TROF AXIS FROM SOUTHERN CANADA AND CLOSES OFF OVER THE UPPER MISSISSIPPI VALLEY ON SUNDAY. ECMWF WAS SHOWING A WAVE ALONG THE SURFACE FRONT WHICH WILL LIKELY SLOW THE PASSAGE OF THE BOUNDARY ACROSS THE AREA ON WEDNESDAY NIGHT AND THURSDAY. THE FRONT SHOULD BE WELL OFF THE SOUTHEAST COAST ON FRIDAY. FRIDAY NIGHT THROUGH SUNDAY HIGH PRESSURE IS BUILDING OVER THE GULF OF MEXICO AND THE SOUTHEAST UNITED STATES. MODELS STILL BRING UNSEASONABLY COLD AIR INTO THE AREA BEHIND THIS SYSTEM ON THURSDAY NIGHT AND FRIDAY. SUNDAY MORNING HAS THE POTENTIAL TO REACH WELL INTO THE 30S FOR LOWS IN THE MOUNTAINS. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AS OF 650 AM EDT MONDAY... INCREASINGLY MOIST EASTERLY FLOW WILL CONTINUE TODAY WITH THE CURRENT VFR CIGS/VSBYS DETERIORATING TOWARD MVFR ESPCLY ALONG THE BLUE RIDGE AND POINTS EAST THROUGH LATE MORNING. DEEPER MOISTURE ADVECTION SHOULD PRODUCE EVEN LOWER CIGS AND INCREASING PRECIPITATION CHANCES AGAIN BY AFTERNOON WITH A LOBE OF SHOWERS PROGGED TO MOVE EAST THROUGH THE AREA AHEAD OF ANOTHER MID LEVEL WAVE ALOFT...WITH EVEN SOME CHANCE FOR THUNDER BUT MUCH BETTER CHANCES TO OUR SOUTH AND WEST THIS AFTERNOON. LATEST GUIDANCE SUGGESTS THAT ONCE THE INITIAL PATCHY RAINFALL EXITS AND THE WEDGE BECOMES BETTER ENHANCED WILL SEE FLYING CONDITIONS QUICKLY WORSEN THIS AFTERNOON WITH STRATUS/FOG DEVELOPING IN MANY LOCATIONS MAKING FOR WIDESPREAD MVFR TO IFR FOR ALL SITES WITH LIFR POSSIBLE ESPCLY AROUND BCB/ROA TO THE EAST. THIS MAY ACTUALLY OCCUR WITH LACK OF PRECIP THIS EVENING AS THE MAIN BATCH OF CONVECTION AHEAD OF THE FRONT ALOFT REMAINS OFF TO THE WEST. POOR FLYING CONDITIONS WILL PREVAIL OVERNIGHT AS DEEP LAYER MOISTURE ON EASTERLY FLOW GETS ENTRENCHED WITH PATCHY -RA/DZ AN FOG AROUND MAKING FOR WIDESPREAD IFR/LIFR CIGS AND MVFR TO IFR VSBYS OVERNIGHT. BANDS OF HEAVIER SHOWERS AND POSSIBLE THUNDERSTORMS ARRIVE TUESDAY WITH WIDESPREAD SUB-VFR CONDITIONS CONTINUING INTO TUESDAY EVENING. EXTENDED AVIATION DISCUSSION... THE MIDWEEK PERIOD WILL BE DOMINATED BY CLOUD COVER AS A DEEP AREA OF LOW PRESSURE ALOFT SLOWLY DRIFTS INTO THE REGION FROM THE WEST. SUB VFR CONDITIONS CAN BE EXPECTED AGAIN ON WEDNESDAY WITH POTENTIAL FOR BANDS OF SHRA/TSRA IN ADDITION TO AREAS OF LIGHT RAIN AND DRIZZLE NEAR THE BLUE RIDGE. APPEARS ENOUGH DRYING ALOFT TO PERHAPS SEE IMPROVEMENT TO VFR ACROSS THE EAST LATER THURSDAY INTO FRIDAY WITH MVFR LIKELY LINGERING AT TIMES ACROSS THE SE WEST VA LOCATIONS INTO FRIDAY. && .HYDROLOGY... AS OF 300 PM EDT SUNDAY... THERE IS A CHANCE FOR MAINSTEM RIVER FLOODING BY MID TO LATE THIS WEEK. BUT STILL FAR TOO EARLY FOR HIGH CONFIDENCE IN WHICH RIVERS AND HOW WIDESPREAD FLOODING WILL BE. STAY TUNED. PATTERN SETTING UP WITH SOME IMPRESSIVE STRONG SIGNALS FOR A PROLONGED PERIOD OF RAINFALL WITH HEAVY RAIN AMOUNTS BECOMING MORE LIKELY...ESPECIALLY TUESDAY AFTERNOON INTO WEDNESDAY. LATEST RUNS OF ENSEMBLE MODEL FORECAST FROM THE GEFS AND THE NAEFS WERE SUGGESTING AN INCREASING PROBABILITY OF MODERATE RIVER FLOODING ON THE DAN RIVER AT SOUTH BOSTON AND ON THE ROANOKE AT RANDOLPH. FLOODING POSSIBILITIES ARE ALSO INDICATED FOR PARTS OF THE JAMES AND GREENBRIER RIVER BASINS. FLASH FLOODING APPEARS TO BE LESS OF A LIKELIHOOD AT LEAST AT THE ONSET AS MUCH OF THE RAINFALL WILL BE OF THE STRATIFORM VARIETY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/PC/WP NEAR TERM...JH SHORT TERM...KK LONG TERM...KK AVIATION...JH/KM/PC/PM HYDROLOGY...AMS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
647 PM EDT MON APR 28 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 349 PM EDT MON APR 28 2014 A LARGE UPPER LEVEL LOW PRESSURE SYSTEM HANGING AROUND THE MIDWEST FOR THE NEXT SEVERAL DAYS WILL KEEP UNSETTLED WEATHER IN THE FORECAST. CHANCES FOR THUNDERSTORMS WILL REMAIN TONIGHT THROUGH TUESDAY NIGHT WITH SOME INSTABILITY AROUND...AND CHANCES FOR RAIN WILL CONTINUE INTO THE WEEKEND. && .NEAR TERM /THIS EVENING AND TONIGHT/... ISSUED AT 349 PM EDT MON APR 28 2014 RADAR MOSAIC AT 330 PM SHOWS A LARGE AREA OF SHOWERS WITH SOME EMBEDDED THUNDER MOVING NORTHEAST THROUGH THE SOUTHERN PORTIONS OF CENTRAL INDIANA STRETCHING BACK SOUTHWEST INTO SOUTHERN ILLINOIS AND WESTERN KENTUCKY. ANOTHER LINE OF STORMS COULD BE FOUND ALONG THE COLD FRONT/DRY LINE IN EASTERN MISSOURI HEADING INTO ILLINOIS...AND SOME OTHER CELLS FORMING ALONG THE PORTION OF THE WARM FRONT IN IOWA AND WESTERN TO CENTRAL ILLINOIS. VISIBLE SATELLITE SHOWS CENTRAL INDIANA SOCKED IN WITH CLOUD COVER AS IT HAS BEEN ALL DAY. HI RES MODELS CONTINUE TO SHOW BIG DISAGREEMENTS IN THE SHORT TERM AND HOW/WHERE CONVECTION WILL DEVELOP FOR THE REMAINDER OF THE AFTERNOON INTO TONIGHT MAKING THIS A FORECAST WITH HIGH UNCERTAINTY. HRRR MOVES THE CURRENT ECHOES NORTHEAST THROUGH THE AREA OVER THE NEXT FEW HOURS...BUT THEN SHOWS LITTLE DEVELOPMENT UNTIL THE COLD FRONT MOVES IN LATER TONIGHT /AROUND 4Z OR SO IN THE WEST/. RAP DEVELOPS SCATTERED CONVECTION ACROSS THE AREA AND AN ORGANIZED AREA ALONG THE WARM FRONT STRETCHING ACROSS NORTHERN AND CENTRAL INDIANA. 18Z ILX SOUNDING SHOWED A PRETTY DECENT INVERSION AND BASED ON ACTIVITY /OR LACK THEREOF/ ACROSS CENTRAL INDIANA INFER THAT THE INVERSION COULD BE MORE STOUT HERE. IN ADDITION INSTABILITY HERE IS LIMITED DUE TO THE AFOREMENTIONED CLOUD COVER. NAM12 SHOWS 500 MB JET MAX APPROACHING OVER THE NEXT COUPLE OF HOURS THOUGH...SO SOME STRONG FORCING POTENTIAL WITH SOME SHEAR IS STILL OUT THERE. THUS NOT READY TO ABANDON THE SEVERE RISK YET BUT DO THINK IT COULD BE DECREASING AT LEAST FOR CENTRAL INDIANA. TIMED THE NEXT FEW HOURS OF POP GRIDS BASED ON THE HRRR AND RADAR LOOP. FOR THE TONIGHT PERIOD THERE ARE SOME BIG DIFFERENCES IN HRRR...RAP...NAM12 AND GFS AS WELL AS SREFS. FINALLY DECIDED GIVEN THE HIGH UNCERTAINTY WOULD INCLUDE A HIGH CHANCE POP AND SCATTERED THUNDERSTORM WORDING. DID NOT FEEL CONFIDENT ENOUGH ON PLACEMENT/TIMING TO GET ANY MORE SPECIFIC THAN THAT UNTIL AFTER 6Z WHEN CHANCES SHOULD START TO DECREASE FROM WEST TO EAST. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... ISSUED AT 349 PM EDT MON APR 28 2014 FORECAST FOCUS IS ON POPS THROUGHOUT AND SEVERE POTENTIAL TUESDAY. MODELS ARE SHOWING AGREEMENT ON GENERAL PATTERN BUT DIFFERENCES ON THE DETAILS THAT DETERMINE TIMING OF PRECIP. GENERALLY TRIED TO USE AN AVERAGE. FOR TUESDAY EXPECT TO SEE A LULL IN THE PRECIP ON TUESDAY MORNING AS THE FRONT WILL BE NORTH OF THE AREA AND UPPER LOW VORT MAXES ARE NOT IN FAVORABLE POSITIONS. BY AFTERNOON THOUGH STEEP LAPSE RATES ADVECT IN AND SOME INSTABILITY BUILDS EVEN THOUGH SOME DRYING OF THE AIR MASS WILL HAVE OCCURRED. A VORT MAX WILL APPROACH FROM THE SOUTHWEST LEADING UP TO 0Z. BEST JET DYNAMICS LOOK LIKE THEY WILL SET UP EAST OF THE AREA...BUT STILL ENOUGH IN PLACE ESPECIALLY WITH THE STEEP LAPSE RATES THAT LARGE HAIL COULD BE A PROBLEM. STUCK WITH MAV POPS BUT RAMPED UP TO THEM WITH THE BEST POTENTIAL STARTING AROUND 21Z. BROUGHT LIKELY IN THE EAST AFTER 0Z WED AS VORT MAX ROTATES THROUGH THE EASTERN COUNTIES AND ANOTHER WEAK SURFACE BOUNDARY MOVES NORTH THROUGH THE AREA. KEPT CHANCES FOR RAIN GOING WEDNESDAY AND THURSDAY UNDER THE INFLUENCE OF THE UPPER LOW AND DROPPED TO A SLIGHT CHANCE IN THE SOUTHWEST ON WEDNESDAY NIGHT WITH LESS FORCING AVAILABLE THEN. LOOKS LIKE MOST INSTABILITY WILL BE MOVING OUT AND THE UPPER LOW WEAKENS AS IT WOBBLES AROUND WEDNESDAY THROUGH THURSDAY SO DID NOT INCLUDE THUNDER DURING THOSE TIMES. FOR TEMPERATURES TUESDAY STUCK CLOSER TO THE COOLER MET NUMBERS WITH MAV LOOKING TOO WARM GIVEN EXPECTED CLOUD COVER. OTHERWISE GENERALLY USED CONSENSUS NUMBERS. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... ISSUED AT 203 PM EDT MON APR 28 2014 A LARGE UPPER LOW OVER THE GREAT LAKES WILL LIFT NORTH INTO SOUTHERN CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY AS PRECIPITATION CHANCES WANE AND TEMPERATURES BEGIN TO INCREASE BACK TOWARD NORMAL. A FEW WAVES WILL ROTATE THROUGH THE REGION THROUGH EARLY THIS WEEKEND ALLOWING MOSTLY CLOUDY SKIES AND CHANCE FOR SHOWERS TO PERSIST. A RETURN TO MORE CLIMO TEMPS AND DRY WEATHER LOOKS TO BE IN STORE FOR EARLY NEXT WEEK. && .AVIATION /DISCUSSION FOR 290000Z TAF ISSUANCE/... ISSUED AT 647 PM EDT MON APR 28 2014 MVFR OR LOWER POSSIBLE IN CONVECTION...ESPECIALLY IN THE FIRST 6 HOURS OR SO OF THE TAF PERIOD. OTHERWISE GENERALLY VFR EXPECTED. AREA OF SHOWERS AND SCATTERED THUNDERSTORMS WILL MOVE INTO THE AREA FROM THE SOUTHWEST EARLY IN THE PERIOD. LATEST OBSERVATIONS NOT SHOWING A LOT OF MVFR CONDITIONS WITH THESE. THUS WILL GO WITH VFR CONDITIONS IN THIS AREA WITH VCTS MENTION. OF COURSE IN ANY HEAVIER CONVECTION MVFR OR LOWER IS POSSIBLE BRIEFLY. WATCHING LINE OF TSRA ACROSS ILLINOIS THAT IS MOVING TOWARD THE AREA. MAY HAVE TO ADD TEMPO GROUPS FOR THIS LINE LATER THIS EVENING IF IT HOLDS TOGETHER. AGAIN MVFR OR WORSE POSSIBLE WITH THIS LINE. OVERNIGHT SCATTERED SHOWERS ARE STILL POSSIBLE SO WILL KEEP VCSH. ON TUESDAY ADDITIONAL CONVECTION MAY DEVELOP IN AFTERNOON BUT NOT SURE ON LOCATION/COVERAGE SO LEFT OUT OF TAFS. WINDS WILL GUST OVER 20KT TUESDAY. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CP NEAR TERM...CP SHORT TERM...CP LONG TERM....SMF AVIATION...50 VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
422 PM EDT MON APR 28 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 349 PM EDT MON APR 28 2014 A LARGE UPPER LEVEL LOW PRESSURE SYSTEM HANGING AROUND THE MIDWEST FOR THE NEXT SEVERAL DAYS WILL KEEP UNSETTLED WEATHER IN THE FORECAST. CHANCES FOR THUNDERSTORMS WILL REMAIN TONIGHT THROUGH TUESDAY NIGHT WITH SOME INSTABILITY AROUND...AND CHANCES FOR RAIN WILL CONTINUE INTO THE WEEKEND. && .NEAR TERM /THIS EVENING AND TONIGHT/... ISSUED AT 349 PM EDT MON APR 28 2014 RADAR MOSAIC AT 330 PM SHOWS A LARGE AREA OF SHOWERS WITH SOME EMBEDDED THUNDER MOVING NORTHEAST THROUGH THE SOUTHERN PORTIONS OF CENTRAL INDIANA STRETCHING BACK SOUTHWEST INTO SOUTHERN ILLINOIS AND WESTERN KENTUCKY. ANOTHER LINE OF STORMS COULD BE FOUND ALONG THE COLD FRONT/DRY LINE IN EASTERN MISSOURI HEADING INTO ILLINOIS...AND SOME OTHER CELLS FORMING ALONG THE PORTION OF THE WARM FRONT IN IOWA AND WESTERN TO CENTRAL ILLINOIS. VISIBLE SATELLITE SHOWS CENTRAL INDIANA SOCKED IN WITH CLOUD COVER AS IT HAS BEEN ALL DAY. HI RES MODELS CONTINUE TO SHOW BIG DISAGREEMENTS IN THE SHORT TERM AND HOW/WHERE CONVECTION WILL DEVELOP FOR THE REMAINDER OF THE AFTERNOON INTO TONIGHT MAKING THIS A FORECAST WITH HIGH UNCERTAINTY. HRRR MOVES THE CURRENT ECHOES NORTHEAST THROUGH THE AREA OVER THE NEXT FEW HOURS...BUT THEN SHOWS LITTLE DEVELOPMENT UNTIL THE COLD FRONT MOVES IN LATER TONIGHT /AROUND 4Z OR SO IN THE WEST/. RAP DEVELOPS SCATTERED CONVECTION ACROSS THE AREA AND AN ORGANIZED AREA ALONG THE WARM FRONT STRETCHING ACROSS NORTHERN AND CENTRAL INDIANA. 18Z ILX SOUNDING SHOWED A PRETTY DECENT INVERSION AND BASED ON ACTIVITY /OR LACK THEREOF/ ACROSS CENTRAL INDIANA INFER THAT THE INVERSION COULD BE MORE STOUT HERE. IN ADDITION INSTABILITY HERE IS LIMITED DUE TO THE AFOREMENTIONED CLOUD COVER. NAM12 SHOWS 500 MB JET MAX APPROACHING OVER THE NEXT COUPLE OF HOURS THOUGH...SO SOME STRONG FORCING POTENTIAL WITH SOME SHEAR IS STILL OUT THERE. THUS NOT READY TO ABANDON THE SEVERE RISK YET BUT DO THINK IT COULD BE DECREASING AT LEAST FOR CENTRAL INDIANA. TIMED THE NEXT FEW HOURS OF POP GRIDS BASED ON THE HRRR AND RADAR LOOP. FOR THE TONIGHT PERIOD THERE ARE SOME BIG DIFFERENCES IN HRRR...RAP...NAM12 AND GFS AS WELL AS SREFS. FINALLY DECIDED GIVEN THE HIGH UNCERTAINTY WOULD INCLUDE A HIGH CHANCE POP AND SCATTERED THUNDERSTORM WORDING. DID NOT FEEL CONFIDENT ENOUGH ON PLACEMENT/TIMING TO GET ANY MORE SPECIFIC THAN THAT UNTIL AFTER 6Z WHEN CHANCES SHOULD START TO DECREASE FROM WEST TO EAST. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... ISSUED AT 349 PM EDT MON APR 28 2014 FORECAST FOCUS IS ON POPS THROUGHOUT AND SEVERE POTENTIAL TUESDAY. MODELS ARE SHOWING AGREEMENT ON GENERAL PATTERN BUT DIFFERENCES ON THE DETAILS THAT DETERMINE TIMING OF PRECIP. GENERALLY TRIED TO USE AN AVERAGE. FOR TUESDAY EXPECT TO SEE A LULL IN THE PRECIP ON TUESDAY MORNING AS THE FRONT WILL BE NORTH OF THE AREA AND UPPER LOW VORT MAXES ARE NOT IN FAVORABLE POSITIONS. BY AFTERNOON THOUGH STEEP LAPSE RATES ADVECT IN AND SOME INSTABILITY BUILDS EVEN THOUGH SOME DRYING OF THE AIR MASS WILL HAVE OCCURRED. A VORT MAX WILL APPROACH FROM THE SOUTHWEST LEADING UP TO 0Z. BEST JET DYNAMICS LOOK LIKE THEY WILL SET UP EAST OF THE AREA...BUT STILL ENOUGH IN PLACE ESPECIALLY WITH THE STEEP LAPSE RATES THAT LARGE HAIL COULD BE A PROBLEM. STUCK WITH MAV POPS BUT RAMPED UP TO THEM WITH THE BEST POTENTIAL STARTING AROUND 21Z. BROUGHT LIKELY IN THE EAST AFTER 0Z WED AS VORT MAX ROTATES THROUGH THE EASTERN COUNTIES AND ANOTHER WEAK SURFACE BOUNDARY MOVES NORTH THROUGH THE AREA. KEPT CHANCES FOR RAIN GOING WEDNESDAY AND THURSDAY UNDER THE INFLUENCE OF THE UPPER LOW AND DROPPED TO A SLIGHT CHANCE IN THE SOUTHWEST ON WEDNESDAY NIGHT WITH LESS FORCING AVAILABLE THEN. LOOKS LIKE MOST INSTABILITY WILL BE MOVING OUT AND THE UPPER LOW WEAKENS AS IT WOBBLES AROUND WEDNESDAY THROUGH THURSDAY SO DID NOT INCLUDE THUNDER DURING THOSE TIMES. FOR TEMPERATURES TUESDAY STUCK CLOSER TO THE COOLER MET NUMBERS WITH MAV LOOKING TOO WARM GIVEN EXPECTED CLOUD COVER. OTHERWISE GENERALLY USED CONSENSUS NUMBERS. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... ISSUED AT 203 PM EDT MON APR 28 2014 A LARGE UPPER LOW OVER THE GREAT LAKES WILL LIFT NORTH INTO SOUTHERN CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY AS PRECIPITATION CHANCES WANE AND TEMPERATURES BEGIN TO INCREASE BACK TOWARD NORMAL. A FEW WAVES WILL ROTATE THROUGH THE REGION THROUGH EARLY THIS WEEKEND ALLOWING MOSTLY CLOUDY SKIES AND CHANCE FOR SHOWERS TO PERSIST. A RETURN TO MORE CLIMO TEMPS AND DRY WEATHER LOOKS TO BE IN STORE FOR EARLY NEXT WEEK. && .AVIATION /DISCUSSION FOR 282100Z TAF UPDATE/... ISSUED AT 422 PM EDT MON APR 28 2014 AREA OF SHOWERS AND ISOLATED THUNDERSTORMS SHOULD STAY SOUTH AND EAST OF KIND FOR NOW /OTHER THAN PERHAPS SOME SPRINKLES AT THE MOMENT/ SO REMOVED MENTION. BEFORE ADDITIONAL SHOWERS/STORMS MOVE IN AFTER 00Z LOOKS LIKE VFR CONDITIONS WILL PREVAIL WITH GUSTY WINDS. PREVIOUS DISCUSSION FOLLOWS... GUIDANCE IS INDICATING THERE WILL BE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. TIMING VARIES AMONG THE MODELS SO THE AVIATION FORECAST IS VERY DIFFICULT TO PIN DOWN AT THIS TIME. BASED ON HRRR...ADDED -SHRA AND VCTS WITH CB GROUPS TO MANY OF THE TAF SITES AS THIS SHORT RANGE MODEL INDICATES THE NEXT ROUND FOR SHOWERS WILL BEGIN IMPACTING CENTRAL INDIANA. THEN AS A WARM FRONT LIFTS NORTH OVER THE REGION THIS EVENING AND WE ARE FIRMLY PLACED IN THE WARM SECTOR EXPECT SCATTERED SHRA/TSRA TO CONTINUE OVERNIGHT. COULD BE ANOTHER PERIOD OF MVFR CEILINGS TONIGHT WHICH WAS INDICATED IN THE TAFS. A LULL IN ACTIVITY MAY BE IN STORE FOR EARLY TOMORROW BEFORE A COLD FRONT MOVES THROUGH TUESDAY AFTERNOON. EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CP NEAR TERM...CP SHORT TERM...CP LONG TERM....SMF AVIATION...SMF/50 VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
351 PM EDT MON APR 28 2014 .UPDATE... THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 349 PM EDT MON APR 28 2014 A LARGE UPPER LEVEL LOW PRESSURE SYSTEM HANGING AROUND THE MIDWEST FOR THE NEXT SEVERAL DAYS WILL KEEP UNSETTLED WEATHER IN THE FORECAST. CHANCES FOR THUNDERSTORMS WILL REMAIN TONIGHT THROUGH TUESDAY NIGHT WITH SOME INSTABILITY AROUND...AND CHANCES FOR RAIN WILL CONTINUE INTO THE WEEKEND. && .NEAR TERM /THIS EVENING AND TONIGHT/... ISSUED AT 349 PM EDT MON APR 28 2014 RADAR MOSAIC AT 330 PM SHOWS A LARGE AREA OF SHOWERS WITH SOME EMBEDDED THUNDER MOVING NORTHEAST THROUGH THE SOUTHERN PORTIONS OF CENTRAL INDIANA STRETCHING BACK SOUTHWEST INTO SOUTHERN ILLINOIS AND WESTERN KENTUCKY. ANOTHER LINE OF STORMS COULD BE FOUND ALONG THE COLD FRONT/DRY LINE IN EASTERN MISSOURI HEADING INTO ILLINOIS...AND SOME OTHER CELLS FORMING ALONG THE PORTION OF THE WARM FRONT IN IOWA AND WESTERN TO CENTRAL ILLINOIS. VISIBLE SATELLITE SHOWS CENTRAL INDIANA SOCKED IN WITH CLOUD COVER AS IT HAS BEEN ALL DAY. HI RES MODELS CONTINUE TO SHOW BIG DISAGREEMENTS IN THE SHORT TERM AND HOW/WHERE CONVECTION WILL DEVELOP FOR THE REMAINDER OF THE AFTERNOON INTO TONIGHT MAKING THIS A FORECAST WITH HIGH UNCERTAINTY. HRRR MOVES THE CURRENT ECHOES NORTHEAST THROUGH THE AREA OVER THE NEXT FEW HOURS...BUT THEN SHOWS LITTLE DEVELOPMENT UNTIL THE COLD FRONT MOVES IN LATER TONIGHT /AROUND 4Z OR SO IN THE WEST/. RAP DEVELOPS SCATTERED CONVECTION ACROSS THE AREA AND AN ORGANIZED AREA ALONG THE WARM FRONT STRETCHING ACROSS NORTHERN AND CENTRAL INDIANA. 18Z ILX SOUNDING SHOWED A PRETTY DECENT INVERSION AND BASED ON ACTIVITY /OR LACK THEREOF/ ACROSS CENTRAL INDIANA INFER THAT THE INVERSION COULD BE MORE STOUT HERE. IN ADDITION INSTABILITY HERE IS LIMITED DUE TO THE AFOREMENTIONED CLOUD COVER. NAM12 SHOWS 500 MB JET MAX APPROACHING OVER THE NEXT COUPLE OF HOURS THOUGH...SO SOME STRONG FORCING POTENTIAL WITH SOME SHEAR IS STILL OUT THERE. THUS NOT READY TO ABANDON THE SEVERE RISK YET BUT DO THINK IT COULD BE DECREASING AT LEAST FOR CENTRAL INDIANA. TIMED THE NEXT FEW HOURS OF POP GRIDS BASED ON THE HRRR AND RADAR LOOP. FOR THE TONIGHT PERIOD THERE ARE SOME BIG DIFFERENCES IN HRRR...RAP...NAM12 AND GFS AS WELL AS SREFS. FINALLY DECIDED GIVEN THE HIGH UNCERTAINTY WOULD INCLUDE A HIGH CHANCE POP AND SCATTERED THUNDERSTORM WORDING. DID NOT FEEL CONFIDENT ENOUGH ON PLACEMENT/TIMING TO GET ANY MORE SPECIFIC THAN THAT UNTIL AFTER 6Z WHEN CHANCES SHOULD START TO DECREASE FROM WEST TO EAST. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... ISSUED AT 349 PM EDT MON APR 28 2014 FORECAST FOCUS IS ON POPS THROUGHOUT AND SEVERE POTENTIAL TUESDAY. MODELS ARE SHOWING AGREEMENT ON GENERAL PATTERN BUT DIFFERENCES ON THE DETAILS THAT DETERMINE TIMING OF PRECIP. GENERALLY TRIED TO USE AN AVERAGE. FOR TUESDAY EXPECT TO SEE A LULL IN THE PRECIP ON TUESDAY MORNING AS THE FRONT WILL BE NORTH OF THE AREA AND UPPER LOW VORT MAXES ARE NOT IN FAVORABLE POSITIONS. BY AFTERNOON THOUGH STEEP LAPSE RATES ADVECT IN AND SOME INSTABILITY BUILDS EVEN THOUGH SOME DRYING OF THE AIR MASS WILL HAVE OCCURRED. A VORT MAX WILL APPROACH FROM THE SOUTHWEST LEADING UP TO 0Z. BEST JET DYNAMICS LOOK LIKE THEY WILL SET UP EAST OF THE AREA...BUT STILL ENOUGH IN PLACE ESPECIALLY WITH THE STEEP LAPSE RATES THAT LARGE HAIL COULD BE A PROBLEM. STUCK WITH MAV POPS BUT RAMPED UP TO THEM WITH THE BEST POTENTIAL STARTING AROUND 21Z. BROUGHT LIKELY IN THE EAST AFTER 0Z WED AS VORT MAX ROTATES THROUGH THE EASTERN COUNTIES AND ANOTHER WEAK SURFACE BOUNDARY MOVES NORTH THROUGH THE AREA. KEPT CHANCES FOR RAIN GOING WEDNESDAY AND THURSDAY UNDER THE INFLUENCE OF THE UPPER LOW AND DROPPED TO A SLIGHT CHANCE IN THE SOUTHWEST ON WEDNESDAY NIGHT WITH LESS FORCING AVAILABLE THEN. LOOKS LIKE MOST INSTABILITY WILL BE MOVING OUT AND THE UPPER LOW WEAKENS AS IT WOBBLES AROUND WEDNESDAY THROUGH THURSDAY SO DID NOT INCLUDE THUNDER DURING THOSE TIMES. FOR TEMPERATURES TUESDAY STUCK CLOSER TO THE COOLER MET NUMBERS WITH MAV LOOKING TOO WARM GIVEN EXPECTED CLOUD COVER. OTHERWISE GENERALLY USED CONSENSUS NUMBERS. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... ISSUED AT 203 PM EDT MON APR 28 2014 A LARGE UPPER LOW OVER THE GREAT LAKES WILL LIFT NORTH INTO SOUTHERN CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY AS PRECIPITATION CHANCES WANE AND TEMPERATURES BEGIN TO INCREASE BACK TOWARD NORMAL. A FEW WAVES WILL ROTATE THROUGH THE REGION THROUGH EARLY THIS WEEKEND ALLOWING MOSTLY CLOUDY SKIES AND CHANCE FOR SHOWERS TO PERSIST. A RETURN TO MORE CLIMO TEMPS AND DRY WEATHER LOOKS TO BE IN STORE FOR EARLY NEXT WEEK. && .AVIATION /DISCUSSION FOR 281800Z TAF ISSUANCE/... ISSUED AT 115 PM EDT MON APR 28 2014 GUIDANCE IS INDICATING THERE WILL BE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. TIMING VARIES AMONG THE MODELS SO THE AVIATION FORECAST IS VERY DIFFICULT TO PIN DOWN AT THIS TIME. BASED ON HRRR...ADDED -SHRA AND VCTS WITH CB GROUPS TO MANY OF THE TAF SITES AS THIS SHORT RANGE MODEL INDICATES THE NEXT ROUND FOR SHOWERS WILL BEGIN IMPACTING CENTRAL INDIANA. THEN AS A WARM FRONT LIFTS NORTH OVER THE REGION THIS EVENING AND WE ARE FIRMLY PLACED IN THE WARM SECTOR EXPECT SCATTERED SHRA/TSRA TO CONTINUE OVERNIGHT. COULD BE ANOTHER PERIOD OF MVFR CEILINGS TONIGHT WHICH WAS INDICATED IN THE TAFS. A LULL IN ACTIVITY MAY BE IN STORE FOR EARLY TOMORROW BEFORE A COLD FRONT MOVES THROUGH TUESDAY AFTERNOON. EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CP NEAR TERM...CP SHORT TERM...CP LONG TERM....SMF AVIATION...SMF VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
204 PM EDT MON APR 28 2014 .UPDATE... THE LONG TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 304 AM EDT MON APR 28 2014 A LARGE AND SLOW MOVING LOW PRESSURE SYSTEM IS EXPECTED TO GRADUALLY MOVE FROM THE PLAINS INTO THE GREAT LAKES REGION BY LATE THIS WEEK. THIS LOW WILL KEEP THE WEATHER UNSETTLED FOR MOST OF THIS UPCOMING WEEK. && .NEAR TERM /TODAY AND TONIGHT/... ISSUED AT 950 AM EDT MON APR 28 2014 RADAR MOSAIC AT 930 AM SHOWS LARGE AREA OF RAIN OVER THE NORTHEAST HALF OR SO OF THE AREA MOVING OFF TO THE NORTHEAST WITH MORE RAIN OVER SOUTHERN ILLINOIS/WESTERN KENTUCKY MOVING NORTHEAST AS WELL TOWARD SOUTHERN INDIANA. VISIBLE SATELLITE SHOWS A CLEAR SLOT OVER CENTRAL ILLINOIS...BUT A LOOP OF THIS FEATURE SHOWS IT ROTATING MAINLY TO THE NORTH AND THUS COULD STAY OVER ILLINOIS AND MOVE INTO NORTHERN INDIANA BUT KEEP CENTRAL INDIANA IN MOSTLY TO COMPLETELY CLOUDY SKIES FOR THE DAY. FOR THE UPDATE ADDED SOME TIMING FOR POPS FOR THE REST OF THE MORNING/EARLY AFTERNOON WITH A BREAK IN PRECIP MOVING IN FROM THE EAST AND LASTING FOR THE NEXT FEW HOURS. KEPT HIGH CHANCE TO LIKELY POPS GOING IN THE SOUTH FOR THE AFOREMENTIONED ECHOES MOVING NORTHEAST FROM S IL/W KY. HI RES MODELS ARE SHOWING DIFFERENT SCENARIOS FOR THE AFTERNOON/EARLY EVENING AND THIS IS CONTRIBUTING TO HIGH UNCERTAINTY FOR THAT PERIOD. HRRR SHOWS ALL DEVELOPMENT OCCURRING TO THE NORTH OF THE AREA WITH NOTHING FURTHER UNTIL THE COLD FRONT ARRIVES LATER TONIGHT. RAP CONTINUES TO DEVELOP SCATTERED CONVECTION THIS AFTERNOON. HESITANT TO BUY INTO HRRR HOOK LINE AND SINKER WITH SUCH A DYNAMIC SYSTEM SO WENT WITH LOW CHANCE POPS ACROSS THE AREA LATE MORNING/EARLY AFTERNOON INCREASING TO LIKELY ACROSS THE AREA AFTER 20Z. AGAIN WITH MODEL VARIABILITY...NOT READY TO CHANGE SEVERE OUTLOOK OR TIMING FROM PREVIOUS FORECAST. PREVIOUS DISCUSSION FOLLOWS... ADDITIONAL DEVELOPMENT LATER TODAY A LITTLE MORE QUESTIONABLE...AS SOME OF THE MODEL DATA SUGGEST MORE SHOWER/THUNDERSTORMS DEVELOPMENT THIS AFTERNOON ALONG THE EDGE OF THE APPROACHING DRY SLOT/STEEPER LAPSE RATES...WHILE OTHERS SUGGEST DEVELOPMENT MAY HOLD OFF UNTIL TOWARDS/AFTER 290000Z WHEN SURFACE COLD FRONT/OCCLUSION MOVES THROUGH. AT THIS POINT...WILL KEEP RATHER HIGH POPS GOING THROUGH ABOUT MIDNIGHT TONIGHT...WITH THE HIGHEST POPS THROUGH ABOUT MIDDAY TODAY. SEVERE POTENTIAL TODAY AND TONIGHT A LITTLE LESS CLEAR. MODEL DATA STILL SUGGEST ADEQUATE DEEP SHEAR/LAPSE RATES BY LATER THIS AFTERNOON AND TONIGHT FOR SEVERE...ALTHOUGH THE DEEP SHEAR LOOKS A LITTLE WEAKER TODAY THAN IT DID YESTERDAY. ALSO...LARGE AMOUNTS OF CONVECTION DEVELOPING SOUTH OF THE OHIO RIVER IS GETTING CLOSE TO CUTTING OFF THE FLOW OF DEEPER MOISTURE/MORE UNSTABLE AIR INTO THE AREA. APPEARS THE BEST CHANCE FOR SEVERE WILL BE FROM THE MID AFTERNOON HOURS UNTIL ABOUT MIDNIGHT TONIGHT...EMANATING EITHER FROM DEVELOPMENT ALONG THE EDGE OF DRY SLOT LATER THIS AFTERNOON OR WITH ACTIVITY TONIGHT NEAR THE SURFACE FRONT. TODAY/S GFS MOS SEEMS TO MAY LOST ITS WARM BIAS OF THE PAST COUPLE OF DAYS...AND THE NUMBERS FOR TODAY AND TONIGHT LOOK MORE REASONABLE. ONLY MINOR ADJUSTMENTS PLANNED. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... ISSUED AT 304 AM EDT MON APR 28 2014 MODEL DATA SUGGEST A LARGE UPPER LOW WILL GRADUALLY SHIFT NORTHEAST FROM THE PLAINS INTO THE MIDWEST DURING THIS PERIOD...KEEPING THE WEATHER UNSETTLED. BY TUESDAY...MODEL DATA SUGGEST DRIER AIR WRAPPING AROUND THE UPPER LOW WILL MOVE INTO THE AREA. LAPSE RATES ARE QUITE STEEP ON TUESDAY...HOWEVER BETTER SHEAR PUSHES OFF TO THE EAST WITH TIME. WILL GO WITH CHANCE POPS FOR SHOWERS/THUNDERSTORMS ON TUESDAY AND TUESDAY NIGHT AS A SURFACE TROUGH MOVES THROUGH...WHICH MAY SERVE AS FOCUS FOR CONVECTION. THE PRESENCE OF THE STEEP LAPSE RATES ON TUESDAY SUGGEST HAIL POTENTIAL WITH ANY STRONGER CELLS THAT MAY DEVELOP. WILL KEEP SOME CHANCE POPS GOING INTO WEDNESDAY AND WEDNESDAY NIGHT AS FILLING UPPER LOW MOVES INTO THE GREAT LAKES. BASED OFF ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS HIGHS FOR TUESDAY AND WEDNESDAY LOOK A LITTLE WARM. WILL CUT A FEW DEGREES OFF THE GUIDANCE HIGHS ON BOTH DAYS. LOWS LOOK REASONABLE. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... ISSUED AT 203 PM EDT MON APR 28 2014 A LARGE UPPER LOW OVER THE GREAT LAKES WILL LIFT NORTH INTO SOUTHERN CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY AS PRECIPITATION CHANCES WANE AND TEMPERATURES BEGIN TO INCREASE BACK TOWARD NORMAL. A FEW WAVES WILL ROTATE THROUGH THE REGION THROUGH EARLY THIS WEEKEND ALLOWING MOSTLY CLOUDY SKIES AND CHANCE FOR SHOWERS TO PERSIST. A RETURN TO MORE CLIMO TEMPS AND DRY WEATHER LOOKS TO BE IN STORE FOR EARLY NEXT WEEK. && .AVIATION /DISCUSSION FOR 281800Z TAF ISSUANCE/... ISSUED AT 115 PM EDT MON APR 28 2014 GUIDANCE IS INDICATING THERE WILL BE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. TIMING VARIES AMONG THE MODELS SO THE AVIATION FORECAST IS VERY DIFFICULT TO PIN DOWN AT THIS TIME. BASED ON HRRR...ADDED -SHRA AND VCTS WITH CB GROUPS TO MANY OF THE TAF SITES AS THIS SHORT RANGE MODEL INDICATES THE NEXT ROUND FOR SHOWERS WILL BEGIN IMPACTING CENTRAL INDIANA. THEN AS A WARM FRONT LIFTS NORTH OVER THE REGION THIS EVENING AND WE ARE FIRMLY PLACED IN THE WARM SECTOR EXPECT SCATTERED SHRA/TSRA TO CONTINUE OVERNIGHT. COULD BE ANOTHER PERIOD OF MVFR CEILINGS TONIGHT WHICH WAS INDICATED IN THE TAFS. A LULL IN ACTIVITY MAY BE IN STORE FOR EARLY TOMORROW BEFORE A COLD FRONT MOVES THROUGH TUESDAY AFTERNOON. EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JAS NEAR TERM...JAS/CP SHORT TERM...JAS LONG TERM....SMF AVIATION...SMF VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
123 PM EDT MON APR 28 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 304 AM EDT MON APR 28 2014 A LARGE AND SLOW MOVING LOW PRESSURE SYSTEM IS EXPECTED TO GRADUALLY MOVE FROM THE PLAINS INTO THE GREAT LAKES REGION BY LATE THIS WEEK. THIS LOW WILL KEEP THE WEATHER UNSETTLED FOR MOST OF THIS UPCOMING WEEK. && .NEAR TERM /TODAY AND TONIGHT/... ISSUED AT 950 AM EDT MON APR 28 2014 RADAR MOSAIC AT 930 AM SHOWS LARGE AREA OF RAIN OVER THE NORTHEAST HALF OR SO OF THE AREA MOVING OFF TO THE NORTHEAST WITH MORE RAIN OVER SOUTHERN ILLINOIS/WESTERN KENTUCKY MOVING NORTHEAST AS WELL TOWARD SOUTHERN INDIANA. VISIBLE SATELLITE SHOWS A CLEAR SLOT OVER CENTRAL ILLINOIS...BUT A LOOP OF THIS FEATURE SHOWS IT ROTATING MAINLY TO THE NORTH AND THUS COULD STAY OVER ILLINOIS AND MOVE INTO NORTHERN INDIANA BUT KEEP CENTRAL INDIANA IN MOSTLY TO COMPLETELY CLOUDY SKIES FOR THE DAY. FOR THE UPDATE ADDED SOME TIMING FOR POPS FOR THE REST OF THE MORNING/EARLY AFTERNOON WITH A BREAK IN PRECIP MOVING IN FROM THE EAST AND LASTING FOR THE NEXT FEW HOURS. KEPT HIGH CHANCE TO LIKELY POPS GOING IN THE SOUTH FOR THE AFOREMENTIONED ECHOES MOVING NORTHEAST FROM S IL/W KY. HI RES MODELS ARE SHOWING DIFFERENT SCENARIOS FOR THE AFTERNOON/EARLY EVENING AND THIS IS CONTRIBUTING TO HIGH UNCERTAINTY FOR THAT PERIOD. HRRR SHOWS ALL DEVELOPMENT OCCURRING TO THE NORTH OF THE AREA WITH NOTHING FURTHER UNTIL THE COLD FRONT ARRIVES LATER TONIGHT. RAP CONTINUES TO DEVELOP SCATTERED CONVECTION THIS AFTERNOON. HESITANT TO BUY INTO HRRR HOOK LINE AND SINKER WITH SUCH A DYNAMIC SYSTEM SO WENT WITH LOW CHANCE POPS ACROSS THE AREA LATE MORNING/EARLY AFTERNOON INCREASING TO LIKELY ACROSS THE AREA AFTER 20Z. AGAIN WITH MODEL VARIABILITY...NOT READY TO CHANGE SEVERE OUTLOOK OR TIMING FROM PREVIOUS FORECAST. PREVIOUS DISCUSSION FOLLOWS... ADDITIONAL DEVELOPMENT LATER TODAY A LITTLE MORE QUESTIONABLE...AS SOME OF THE MODEL DATA SUGGEST MORE SHOWER/THUNDERSTORMS DEVELOPMENT THIS AFTERNOON ALONG THE EDGE OF THE APPROACHING DRY SLOT/STEEPER LAPSE RATES...WHILE OTHERS SUGGEST DEVELOPMENT MAY HOLD OFF UNTIL TOWARDS/AFTER 290000Z WHEN SURFACE COLD FRONT/OCCLUSION MOVES THROUGH. AT THIS POINT...WILL KEEP RATHER HIGH POPS GOING THROUGH ABOUT MIDNIGHT TONIGHT...WITH THE HIGHEST POPS THROUGH ABOUT MIDDAY TODAY. SEVERE POTENTIAL TODAY AND TONIGHT A LITTLE LESS CLEAR. MODEL DATA STILL SUGGEST ADEQUATE DEEP SHEAR/LAPSE RATES BY LATER THIS AFTERNOON AND TONIGHT FOR SEVERE...ALTHOUGH THE DEEP SHEAR LOOKS A LITTLE WEAKER TODAY THAN IT DID YESTERDAY. ALSO...LARGE AMOUNTS OF CONVECTION DEVELOPING SOUTH OF THE OHIO RIVER IS GETTING CLOSE TO CUTTING OFF THE FLOW OF DEEPER MOISTURE/MORE UNSTABLE AIR INTO THE AREA. APPEARS THE BEST CHANCE FOR SEVERE WILL BE FROM THE MID AFTERNOON HOURS UNTIL ABOUT MIDNIGHT TONIGHT...EMANATING EITHER FROM DEVELOPMENT ALONG THE EDGE OF DRY SLOT LATER THIS AFTERNOON OR WITH ACTIVITY TONIGHT NEAR THE SURFACE FRONT. TODAY/S GFS MOS SEEMS TO MAY LOST ITS WARM BIAS OF THE PAST COUPLE OF DAYS...AND THE NUMBERS FOR TODAY AND TONIGHT LOOK MORE REASONABLE. ONLY MINOR ADJUSTMENTS PLANNED. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... ISSUED AT 304 AM EDT MON APR 28 2014 MODEL DATA SUGGEST A LARGE UPPER LOW WILL GRADUALLY SHIFT NORTHEAST FROM THE PLAINS INTO THE MIDWEST DURING THIS PERIOD...KEEPING THE WEATHER UNSETTLED. BY TUESDAY...MODEL DATA SUGGEST DRIER AIR WRAPPING AROUND THE UPPER LOW WILL MOVE INTO THE AREA. LAPSE RATES ARE QUITE STEEP ON TUESDAY...HOWEVER BETTER SHEAR PUSHES OFF TO THE EAST WITH TIME. WILL GO WITH CHANCE POPS FOR SHOWERS/THUNDERSTORMS ON TUESDAY AND TUESDAY NIGHT AS A SURFACE TROUGH MOVES THROUGH...WHICH MAY SERVE AS FOCUS FOR CONVECTION. THE PRESENCE OF THE STEEP LAPSE RATES ON TUESDAY SUGGEST HAIL POTENTIAL WITH ANY STRONGER CELLS THAT MAY DEVELOP. WILL KEEP SOME CHANCE POPS GOING INTO WEDNESDAY AND WEDNESDAY NIGHT AS FILLING UPPER LOW MOVES INTO THE GREAT LAKES. BASED OFF ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS HIGHS FOR TUESDAY AND WEDNESDAY LOOK A LITTLE WARM. WILL CUT A FEW DEGREES OFF THE GUIDANCE HIGHS ON BOTH DAYS. LOWS LOOK REASONABLE. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 338 AM EDT MON APR 28 2014 A LARGE UPPER LOW OVER THE GREAT LAKES THURSDAY WILL LIFT NORTH INTO SOUTHERN CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY. A CYCLONIC UPPER FLOW FROM THIS UPPER LOW WILL KEEP MOSTLY CLOUDY SKIES AND CHANCES OF SHOWERS THURSDAY INTO SATURDAY. A WEAK COLD FRONT WILL MOVE ACROSS OUR REGION EARLY SATURDAY FOLLOWED BY A HIGH PRESSURE RIDGE SATURDAY NIGHT. SEVERAL MODELS INDICATE ANOTHER CHANCE OF PRECIPITATION MAY BEGIN SUNDAY AS ANOTHER SYSTEM APPROACHES. ADDED ISOLATED THUNDER TO SUNDAY AS MODELS INDICATE MU CAPES OF UP TO 500 J/KG. OTHERWISE...ANY PRECIPITATION WILL BE ONLY BE SCATTERED LIGHT SHOWERS OR SPRINKLES. TEMPERATURES WILL REMAIN QUITE COOL THURSDAY THROUGH SATURDAY AND THEN MODERATE A LITTLE SUNDAY. ONLY MADE MINOR TWEAKS TO ALL BLEND TEMPERATURES MAINLY TO RAISE MINS SLIGHTLY THURSDAY AND FRIDAY NIGHT AS THERE WILL BE LOTS OF CLOUDS. && .AVIATION /DISCUSSION FOR 281800Z TAF ISSUANCE/... ISSUED AT 115 PM EDT MON APR 28 2014 GUIDANCE IS INDICATING THERE WILL BE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. TIMING VARIES AMONG THE MODELS SO THE AVIATION FORECAST IS VERY DIFFICULT TO PIN DOWN AT THIS TIME. BASED ON HRRR...ADDED -SHRA AND VCTS WITH CB GROUPS TO MANY OF THE TAF SITES AS THIS SHORT RANGE MODEL INDICATES THE NEXT ROUND FOR SHOWERS WILL BEGIN IMPACTING CENTRAL INDIANA. THEN AS A WARM FRONT LIFTS NORTH OVER THE REGION THIS EVENING AND WE ARE FIRMLY PLACED IN THE WARM SECTOR EXPECT SCATTERED SHRA/TSRA TO CONTINUE OVERNIGHT. COULD BE ANOTHER PERIOD OF MVFR CEILINGS TONIGHT WHICH WAS INDICATED IN THE TAFS. A LULL IN ACTIVITY MAY BE IN STORE FOR EARLY TOMORROW BEFORE A COLD FRONT MOVES THROUGH TUESDAY AFTERNOON. EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JAS NEAR TERM...JAS/CP SHORT TERM...JAS LONG TERM....JH AVIATION...SMF VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1238 PM CDT MON APR 28 2014 .UPDATE... ISSUED AT 1126 AM CDT MON APR 28 2014 THE FRONTAL BOUNDARY IS ROUGHLY ALONG A KTQE...KAWG...TO KCMI LINE AT 16Z AND IT HAS NOT MOVED FOR SEVERAL HOURS. TRENDS IN THE RAP INDICATE VERY LITTLE IN THE WAY OF MOMENT OF THIS FRONTAL BOUNDARY THIS AFTERNOON. IF CORRECT...ROUGHLY THE NORTHERN HALF OF THE AREA WILL REMAIN IN THE 50S WITH THE HWY 20 CORRIDOR POSSIBLY STRUGGLING TO REACH 50. SATELLITE TRENDS INDICATE THERMALS ARE ACTIVE WHICH HAS ALLOWED CU TO DEVELOP ALONG/AHEAD OF THE COLD FRONT ACROSS MISSOURI. CONVECTION SHOULD DEVELOP WITHIN A FEW HOURS FROM CENTRAL INTO SOUTHERN MISSOURI ALONG THE FRONT AND MOVE NORTHEAST. PRECIPITATION CHANCES SHOULD THEREFORE BE ON THE INCREASE STARTING AROUND MID AFTERNOON ACROSS THE AREA. UPDATE ISSUED AT 923 AM CDT MON APR 28 2014 RADAR TRENDS INDICATE SHOWERS ACROSS THE NORTHERN PARTS OF THE AREA WILL CONTINUE TO SLOWLY DECAY THE REMAINDER OF THE MORNING. CLOUDS AND STRONG EASTERLY FLOW NORTH OF THE PRONOUNCED FRONT SOUTH OF I-80 WILL KEEP THIS AREA COOL FOR MUCH OF THE DAY. STRONG DIURNAL HEATING SOUTH OF THE FRONT IS EXPECTED TO SET THE STAGE FOR NEW CONVECTION DEVELOPING EITHER LATE THIS MORNING OR DURING THE EARLY AFTERNOON. SATELLITE TRENDS HAS A NARROW BAND OF ACCAS IN SOUTHERN MISSOURI INDICATING INSTABILITY FOR NEW STORMS TO DEVELOP. && .SYNOPSIS... ISSUED AT 357 AM CDT MON APR 28 2014 NEARLY STACKED SURFACE AND UPPER LEVEL LOWS WERE LOCATED OVER CENTRAL NEB EARLY THIS MORNING. WELL OUT IN ADVANCE...AN ELONGATED COMPLEX OF SEVERE STORMS STRETCHED FROM EASTERN TX THROUGH THE MID MS VALLEY INTO THE OHIO RIVER VALLEY. OVER THE LOCAL AREA... WIDESPREAD SHOWERS AND THUNDERSTORMS SUNDAY EVENING HAVE SINCE STRATIFORMED INTO MAINLY WEAKENING LIGHT SHOWERS DRIFTING NORTHWARD THROUGH THE REGION. STRONG EASTERLY WINDS CONTINUE...FROM 20 TO 30 MPH AND AS HIGH AS 30 TO 40 MPH AT TIMES MAINLY NORTH OF I-80. TO THE SOUTH...WINDS WERE MUCH LIGHTER AND VEERED TO MORE SOUTHEASTERLY ALONG AND SOUTH OF THE MAIN STATIONARY FRONT CONNECTED TO THE NEB LOW. IN THE LOCAL AREA THIS BOUNDARY RAN ROUGHLY FROM JUST NORTH OF WASHINGTON SOUTHEAST TO NORTH OF MACOMB. TEMPERATURES AND DEWPOINTS WERE IN THE UPPER 50S TO LOWER 60S SOUTH OF THIS BOUNDARY...WHILE TO THE NORTH TEMPERATURES RANGED FROM THE LOWER 40S NORTH TO LOWER 50S ALONG THE I-80 CORRIDOR. && .SHORT TERM...(TODAY) ISSUED AT 357 AM CDT MON APR 28 2014 FOCUS IS ON THREAT FOR MORE SEVERE WEATHER TODAY. SHARP FRONTAL BOUNDARY WILL LIKELY REMAIN IN PLACE ACROSS THE SOUTH THROUGH MIDDAY...THEN TRY TO LIFT NORTH TOWARD EVENING. PRIMARY SEVERE WEATHER THREAT WILL BE CENTERED PRIMARILY ON SE IA INTO W CENTRAL IL THIS AFTERNOON. UPPER LEVEL DIFLUENCE AND MID LEVEL LIFT ASSOCIATED WITH A LOBE OF ENERGY ROTATING AROUND THE BASE OF THE NEB LOW FOCUSES ON THIS REGION BY AFTERNOON. THIS WILL ENHANCE LIFT OVER THE FRONTAL BOUNDARY...AND WHERE MODELS INDICATE A POTENTIAL FOR MIXED LAYER CAPES OF 1000 J/KG OR HIGHER...SEVERE STORMS WITH LARGE HAIL AND DAMAGING WIND WILL BE POSSIBLE. THIS APPEARS TO BE MAXIMIZED OVER FAR SE IA INTO W CENTRAL IL...WHERE SPC HAS A SLIGHT RISK. IT IS IN THIS REGION THAT THE BETTER SHEAR OVER THE EAST AND HIGHER INSTABILITY AXIS FROM CENTRAL IL REACHING INTO CENTRAL IA MAY OVERLAP. THERE WILL BE A RISK OF TORNADIC STORMS...ESPECIALLY IF THE MODEL ADVERTISED WEAK LOW OR TRIPLE POINT MIGRATES EASTWARD ALONG THE BOUNDARY INTO THIS MORE FAVORABLE ENVIRONMENT. IF THE BOUNDARY WERE TO PUSH FURTHER NORTH THAN ANTICIPATED DURING PEAK HEATING...AS SOME MODELS DEPICT...THIS RISK OF SEVERE STORMS WOULD EXTEND FURTHER NORTH. THE RISK FOR HEAVY RAIN APPEARS TO BE SOMEWHAT LESS CERTAIN CONSIDERING THE LARGE COMPLEXES TO THE SOUTH THAT MAY INTERRUPT THE MOISTURE FEED. THE GREATEST FEED OF DEEP MOISTURE APPEARS TO BE MAXIMIZED OVER THE AREA TONIGHT...THEN MODEL PW FIELDS SHOW A WEAKENING AREA AXIS REACHING INTO NORTHERN IL AND EASTERN IA FROM THE SOUTHEAST TODAY. ANY SEVERE STORMS THAT DEVELOP THIS AFTERNOON WILL CERTAINLY BE CAPABLE OF HEAVY RAINFALL...BUT OUTSIDE OF THESE... RAINFALL AMOUNTS SHOULD NOT BE EXCESSIVE AND HAVE QPF AMOUNTS GENERALLY IN A QUARTER TO HALF INCH RANGE. THE SHARP BOUNDARY WILL AGAIN RESULT IN A WIDE RANGE OF TEMPERATURE AND HAVE HIGHS FROM THE 50S AND 60S ACROSS THE NORTH WITH 70S FAR SOUTH. ..11.. .LONG TERM...(TONIGHT THROUGH NEXT SUNDAY) ISSUED AT 357 AM CDT MON APR 28 2014 TONIGHT...SEVERAL HIRES PROGS AND ASSESSING STANDARD 00Z RUN MODELS SUGGEST AN ARCING CLUSTER OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO PUSH NORTH AND NORTHEAST ACRS THE NORTHERN 2/3S OF THE DVN CWA EARLY THIS EVENING WHILE NEARLY STACKED VORTEX ROLLS ACRS SOUTHWESTERN IA. LINGERING SHEAR AND THERMODYNAMIC PROFILES STILL SUGGEST A FEW STORMS MAY BE STRONG OR SVR THROUGH 02Z TUE ALONG AND JUST NORTH OF OCCLUDED SFC FRONT WHICH IS GENERALLY SREF PLACED ALONG I80...BUT WONDER IF MODELS ARE TOO FAR NORTH WITH THIS FEATURE STILL AT THIS POINT. MUCH OF THE CONVECTIVE ACTIVITY MAY THEN BE ON THE WANE AND EXITING TO THE NORTH OF THE DVN CWA AFTER 03Z THIS EVENING...WITH ADDITIONAL RAINFALL AMOUNTS OF 0.25 TO 0.75 OF AN INCH WHERE THE BAND/MAIN CLUSTER OF STORMS MIGRATES NORTHWARD ACRS. CURRENT THINKING THIS ALONG AND NORTH OF I80 AN TARGETING THE NORTHEASTERN THIRD OF THE DVN CWA. WILL HAVE TO WATCH FOR LOW CLOUDS...FOG AND DRIZZLE IN VCNTY OF LINGERING OCCLUSION OVERNIGHT AFTER THE RAIN CLEARS. WILL HAVE TO WATCH FOR ADDITIONAL WRAP-AROUND SHOWERS OR HYBRID RAIN BANDS ENTERING THE NORTHWESTERN CWA TOWARD DAWN TUE AS UPPER LOW PUSHES TOWARD THE WESTERN CWA. LOW OVERNIGHT GENERALLY IN THE 40S. TUESDAY AND WEDNESDAY...LATEST 00Z RUN MEDIUM RANGE SOLUTIONS CONTINUE TO SUGGEST LARGE SUB TROPICAL VORTEX-NEARLY STACKED MONSTER CYCLONE TO SLOW ROLL IN SOME FASHION ACRS IA TOWARD THE WESTERN GRT LKS THIS PERIOD. WITH THE CENTER OVERHEAD AND DIURNALLY UNSTABLE SOUNDINGS DEVELOPING ON TUE...FEEL THERE COULD BE MORE SCTRD TO ISOLATED THUNDERSTORMS ALONG WITH INHERENT SHOWERS AS THE DAY PROGRESSES. VERTICAL THERMAL PROFILES AND IDEAL WBZ/FZL HEIGHTS CONTINUE TO SUGGEST SOME OF THESE STORMS COULD PRODUCE HAIL WITH ANY SUSTAINED UPDRAFTS. SCTRD SHOWERS/STORMS TO WANE DIURNALLY AFTER SUNSET TUE NIGHT INTO EARLY WED MORNING. AMBIENT TEMPS TO COOL BY WED INTO THE MID 50S OR EVEN THE UPPER 40S AS LOW TO MID LEVEL COLD CONVEYOR INCREASES INTO THE BACKSIDE OF CYCLONE COMPLEX. MORE SHOWERS WED AS SATELLITE VORT SPOKE ROTATES ACRS THE REGION. THURSDAY THROUGH NEXT SUNDAY...LONGER RANGE INDICATIONS ARE NOW A BIT MORE PROGRESSIVE/LESS BLOCKED WITH UPPER LOW ROLLING ALONG INTO THE GRT LKS OR EVEN TOWARD THE SOUTHERN JAMES BAY REGION BY FRI. STILL EXPECT OCCASIONAL ROUNDS OF SHOWERS ESPECIALLY DURING THE DAY...AS WELL AS WELL BELOW NORMAL TEMPS THROUGH THE PERIOD. HIGHS THU AND FRI ONLY IN THE 50S...HAPPY MAY DAY. RESULTANT LARGE/BROAD SCALE L/W UPPER TROF PATTERN ACRS THE EASTERN HALF OF THE CONUS TO CONTINUE A RATHER COOL TEMP REGIME INTO THE WEEKEND FOR MUCH OF THE UPPER MIDWEST/MS RVR VALLEY REGION. BUT THEN LONGER RANGE SIGNALS AND UPPER JET PATTERNS SUGGEST A FLATTENING OF THE MEAN STEERING FLOW REGIME ACRS MUCH OF THE CONUS AS THE WEEKEND PROGRESSES. EMBEDDED RIDGE RIDING/DAMPENING WAVE AND SOME LLVL BAROCLINIC TIGHTENING MAY COMBINE TO BRING MORE RAIN CHANCES TO THE REGION BY LATE SAT NIGHT OR NEXT SUNDAY. ..12.. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1235 PM CDT MON APR 28 2014 IFR CONDS THROUGH MOST OF THIS TAF CYCLE AT KCID/KDBQ OTHERWISE IFR AT KMLI BECOMING MVFR CONDS THIS EVENING. VFR CONDS THROUGH THIS TAF CYCLE AT KBRL. A LINE OF THUNDERSTORMS SHOULD DEVELOP IN SOUTHEAST IA EARLY TO MID AFTERNOON IMPACTING KBRL AND THEN SPREADING NORTHEAST OVER THE REMAINING TAF SITES LATE THIS AFTERNOON AND EVENING. SOME OF THE STORMS ALONG AND SOUTH OF I-80 MAY PRODUCE LARGE HAIL AND DAMAGING WINDS. EAST TO SOUTHEAST WINDS SUSTAINED 15 TO 20 KNOTS WITH GUSTS TO 25 TO 30 KNOTS THIS AFTERNOON...DIMINISHING TO LESS THAN 10 KNOTS THIS EVENING. NORTHEAST WINDS LESS THAN 10 KNOTS ON TUESDAY AT KCID/KDBQ BUT SOUTHWEST WINDS AT KMLI/KBRL. && .HYDROLOGY... ISSUED AT 357 AM CDT MON APR 28 2014 THE FLOOD WATCH FOR AREA RIVERS AND STREAMS CONTINUES TODAY AND THIS EVENING. THE THREAT OF FLOODING ON AREA TRIBUTARIES AND THE MISSISSIPPI RIVER WILL INCREASE AS THE WEEK PROGRESSES WITH A ACCUMULATIVE EFFECT OF SEVERAL RAIN EVENTS...INCLUDING THIS PAST SUNDAY EVENING/S HEAVY RAIN...THEN MORE LOCALIZED HEAVY RAIN POSSIBLE THIS AFTERNOON AND EVENING. LATEST THINKING SUGGESTS WIDESPREAD RAINFALL AMOUNTS OF 1 TO 4 INCHES WILL FALL OVER MUCH OF THE FORECAST AREA BY WEDNESDAY...INCLUDING THE RAINFALL FROM YESTERDAY AND LAST NIGHT. SINCE THE PRECIPITATION WILL OCCUR OVER AN EXTENDED PERIOD OF TIME...THE THREAT OF FLASH FLOODING WILL BE LOW. HOWEVER...RIVER FLOODING IS EXPECTED WITH SEVERAL OF THE AREA TRIBUTARIES AND THE MISSISSIPPI RIVER POSSIBLY SEEING AT LEAST MINOR TO MODERATE FLOODING BY THE MIDDLE OF THE WEEK. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...FLOOD WATCH UNTIL MIDNIGHT CDT TONIGHT FOR BENTON-BUCHANAN-CEDAR- CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-JACKSON- JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-MUSCATINE- SCOTT-VAN BUREN-WASHINGTON. IL...FLOOD WATCH UNTIL MIDNIGHT CDT TONIGHT FOR BUREAU-CARROLL- HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER- PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE. MO...FLOOD WATCH UNTIL MIDNIGHT CDT TONIGHT FOR CLARK-SCOTLAND. && $$ UPDATE...08 SYNOPSIS...11 SHORT TERM...11 LONG TERM...12 AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1134 AM CDT MON APR 28 2014 .UPDATE... ISSUED AT 1126 AM CDT MON APR 28 2014 THE FRONTAL BOUNDARY IS ROUGHLY ALONG A KTQE...KAWG...TO KCMI LINE AT 16Z AND IT HAS NOT MOVED FOR SEVERAL HOURS. TRENDS IN THE RAP INDICATE VERY LITTLE IN THE WAY OF MOMENT OF THIS FRONTAL BOUNDARY THIS AFTERNOON. IF CORRECT...ROUGHLY THE NORTHERN HALF OF THE AREA WILL REMAIN IN THE 50S WITH THE HWY 20 CORRIDOR POSSIBLY STRUGGLING TO REACH 50. SATELLITE TRENDS INDICATE THERMALS ARE ACTIVE WHICH HAS ALLOWED CU TO DEVELOP ALONG/AHEAD OF THE COLD FRONT ACROSS MISSOURI. CONVECTION SHOULD DEVELOP WITHIN A FEW HOURS FROM CENTRAL INTO SOUTHERN MISSOURI ALONG THE FRONT AND MOVE NORTHEAST. PRECIPITATION CHANCES SHOULD THEREFORE BE ON THE INCREASE STARTING AROUND MID AFTERNOON ACROSS THE AREA. UPDATE ISSUED AT 923 AM CDT MON APR 28 2014 RADAR TRENDS INDICATE SHOWERS ACROSS THE NORTHERN PARTS OF THE AREA WILL CONTINUE TO SLOWLY DECAY THE REMAINDER OF THE MORNING. CLOUDS AND STRONG EASTERLY FLOW NORTH OF THE PRONOUNCED FRONT SOUTH OF I-80 WILL KEEP THIS AREA COOL FOR MUCH OF THE DAY. STRONG DIURNAL HEATING SOUTH OF THE FRONT IS EXPECTED TO SET THE STAGE FOR NEW CONVECTION DEVELOPING EITHER LATE THIS MORNING OR DURING THE EARLY AFTERNOON. SATELLITE TRENDS HAS A NARROW BAND OF ACCAS IN SOUTHERN MISSOURI INDICATING INSTABILITY FOR NEW STORMS TO DEVELOP. && .SYNOPSIS... ISSUED AT 357 AM CDT MON APR 28 2014 NEARLY STACKED SURFACE AND UPPER LEVEL LOWS WERE LOCATED OVER CENTRAL NEB EARLY THIS MORNING. WELL OUT IN ADVANCE...AN ELONGATED COMPLEX OF SEVERE STORMS STRETCHED FROM EASTERN TX THROUGH THE MID MS VALLEY INTO THE OHIO RIVER VALLEY. OVER THE LOCAL AREA... WIDESPREAD SHOWERS AND THUNDERSTORMS SUNDAY EVENING HAVE SINCE STRATIFORMED INTO MAINLY WEAKENING LIGHT SHOWERS DRIFTING NORTHWARD THROUGH THE REGION. STRONG EASTERLY WINDS CONTINUE...FROM 20 TO 30 MPH AND AS HIGH AS 30 TO 40 MPH AT TIMES MAINLY NORTH OF I-80. TO THE SOUTH...WINDS WERE MUCH LIGHTER AND VEERED TO MORE SOUTHEASTERLY ALONG AND SOUTH OF THE MAIN STATIONARY FRONT CONNECTED TO THE NEB LOW. IN THE LOCAL AREA THIS BOUNDARY RAN ROUGHLY FROM JUST NORTH OF WASHINGTON SOUTHEAST TO NORTH OF MACOMB. TEMPERATURES AND DEWPOINTS WERE IN THE UPPER 50S TO LOWER 60S SOUTH OF THIS BOUNDARY...WHILE TO THE NORTH TEMPERATURES RANGED FROM THE LOWER 40S NORTH TO LOWER 50S ALONG THE I-80 CORRIDOR. && .SHORT TERM...(TODAY) ISSUED AT 357 AM CDT MON APR 28 2014 FOCUS IS ON THREAT FOR MORE SEVERE WEATHER TODAY. SHARP FRONTAL BOUNDARY WILL LIKELY REMAIN IN PLACE ACROSS THE SOUTH THROUGH MIDDAY...THEN TRY TO LIFT NORTH TOWARD EVENING. PRIMARY SEVERE WEATHER THREAT WILL BE CENTERED PRIMARILY ON SE IA INTO W CENTRAL IL THIS AFTERNOON. UPPER LEVEL DIFLUENCE AND MID LEVEL LIFT ASSOCIATED WITH A LOBE OF ENERGY ROTATING AROUND THE BASE OF THE NEB LOW FOCUSES ON THIS REGION BY AFTERNOON. THIS WILL ENHANCE LIFT OVER THE FRONTAL BOUNDARY...AND WHERE MODELS INDICATE A POTENTIAL FOR MIXED LAYER CAPES OF 1000 J/KG OR HIGHER...SEVERE STORMS WITH LARGE HAIL AND DAMAGING WIND WILL BE POSSIBLE. THIS APPEARS TO BE MAXIMIZED OVER FAR SE IA INTO W CENTRAL IL...WHERE SPC HAS A SLIGHT RISK. IT IS IN THIS REGION THAT THE BETTER SHEAR OVER THE EAST AND HIGHER INSTABILITY AXIS FROM CENTRAL IL REACHING INTO CENTRAL IA MAY OVERLAP. THERE WILL BE A RISK OF TORNADIC STORMS...ESPECIALLY IF THE MODEL ADVERTISED WEAK LOW OR TRIPLE POINT MIGRATES EASTWARD ALONG THE BOUNDARY INTO THIS MORE FAVORABLE ENVIRONMENT. IF THE BOUNDARY WERE TO PUSH FURTHER NORTH THAN ANTICIPATED DURING PEAK HEATING...AS SOME MODELS DEPICT...THIS RISK OF SEVERE STORMS WOULD EXTEND FURTHER NORTH. THE RISK FOR HEAVY RAIN APPEARS TO BE SOMEWHAT LESS CERTAIN CONSIDERING THE LARGE COMPLEXES TO THE SOUTH THAT MAY INTERRUPT THE MOISTURE FEED. THE GREATEST FEED OF DEEP MOISTURE APPEARS TO BE MAXIMIZED OVER THE AREA TONIGHT...THEN MODEL PW FIELDS SHOW A WEAKENING AREA AXIS REACHING INTO NORTHERN IL AND EASTERN IA FROM THE SOUTHEAST TODAY. ANY SEVERE STORMS THAT DEVELOP THIS AFTERNOON WILL CERTAINLY BE CAPABLE OF HEAVY RAINFALL...BUT OUTSIDE OF THESE... RAINFALL AMOUNTS SHOULD NOT BE EXCESSIVE AND HAVE QPF AMOUNTS GENERALLY IN A QUARTER TO HALF INCH RANGE. THE SHARP BOUNDARY WILL AGAIN RESULT IN A WIDE RANGE OF TEMPERATURE AND HAVE HIGHS FROM THE 50S AND 60S ACROSS THE NORTH WITH 70S FAR SOUTH. ..11.. .LONG TERM...(TONIGHT THROUGH NEXT SUNDAY) ISSUED AT 357 AM CDT MON APR 28 2014 TONIGHT...SEVERAL HIRES PROGS AND ASSESSING STANDARD 00Z RUN MODELS SUGGEST AN ARCING CLUSTER OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO PUSH NORTH AND NORTHEAST ACRS THE NORTHERN 2/3S OF THE DVN CWA EARLY THIS EVENING WHILE NEARLY STACKED VORTEX ROLLS ACRS SOUTHWESTERN IA. LINGERING SHEAR AND THERMODYNAMIC PROFILES STILL SUGGEST A FEW STORMS MAY BE STRONG OR SVR THROUGH 02Z TUE ALONG AND JUST NORTH OF OCCLUDED SFC FRONT WHICH IS GENERALLY SREF PLACED ALONG I80...BUT WONDER IF MODELS ARE TOO FAR NORTH WITH THIS FEATURE STILL AT THIS POINT. MUCH OF THE CONVECTIVE ACTIVITY MAY THEN BE ON THE WANE AND EXITING TO THE NORTH OF THE DVN CWA AFTER 03Z THIS EVENING...WITH ADDITIONAL RAINFALL AMOUNTS OF 0.25 TO 0.75 OF AN INCH WHERE THE BAND/MAIN CLUSTER OF STORMS MIGRATES NORTHWARD ACRS. CURRENT THINKING THIS ALONG AND NORTH OF I80 AN TARGETING THE NORTHEASTERN THIRD OF THE DVN CWA. WILL HAVE TO WATCH FOR LOW CLOUDS...FOG AND DRIZZLE IN VCNTY OF LINGERING OCCLUSION OVERNIGHT AFTER THE RAIN CLEARS. WILL HAVE TO WATCH FOR ADDITIONAL WRAP-AROUND SHOWERS OR HYBRID RAIN BANDS ENTERING THE NORTHWESTERN CWA TOWARD DAWN TUE AS UPPER LOW PUSHES TOWARD THE WESTERN CWA. LOW OVERNIGHT GENERALLY IN THE 40S. TUESDAY AND WEDNESDAY...LATEST 00Z RUN MEDIUM RANGE SOLUTIONS CONTINUE TO SUGGEST LARGE SUB TROPICAL VORTEX-NEARLY STACKED MONSTER CYCLONE TO SLOW ROLL IN SOME FASHION ACRS IA TOWARD THE WESTERN GRT LKS THIS PERIOD. WITH THE CENTER OVERHEAD AND DIURNALLY UNSTABLE SOUNDINGS DEVELOPING ON TUE...FEEL THERE COULD BE MORE SCTRD TO ISOLATED THUNDERSTORMS ALONG WITH INHERENT SHOWERS AS THE DAY PROGRESSES. VERTICAL THERMAL PROFILES AND IDEAL WBZ/FZL HEIGHTS CONTINUE TO SUGGEST SOME OF THESE STORMS COULD PRODUCE HAIL WITH ANY SUSTAINED UPDRAFTS. SCTRD SHOWERS/STORMS TO WANE DIURNALLY AFTER SUNSET TUE NIGHT INTO EARLY WED MORNING. AMBIENT TEMPS TO COOL BY WED INTO THE MID 50S OR EVEN THE UPPER 40S AS LOW TO MID LEVEL COLD CONVEYOR INCREASES INTO THE BACKSIDE OF CYCLONE COMPLEX. MORE SHOWERS WED AS SATELLITE VORT SPOKE ROTATES ACRS THE REGION. THURSDAY THROUGH NEXT SUNDAY...LONGER RANGE INDICATIONS ARE NOW A BIT MORE PROGRESSIVE/LESS BLOCKED WITH UPPER LOW ROLLING ALONG INTO THE GRT LKS OR EVEN TOWARD THE SOUTHERN JAMES BAY REGION BY FRI. STILL EXPECT OCCASIONAL ROUNDS OF SHOWERS ESPECIALLY DURING THE DAY...AS WELL AS WELL BELOW NORMAL TEMPS THROUGH THE PERIOD. HIGHS THU AND FRI ONLY IN THE 50S...HAPPY MAY DAY. RESULTANT LARGE/BROAD SCALE L/W UPPER TROF PATTERN ACRS THE EASTERN HALF OF THE CONUS TO CONTINUE A RATHER COOL TEMP REGIME INTO THE WEEKEND FOR MUCH OF THE UPPER MIDWEST/MS RVR VALLEY REGION. BUT THEN LONGER RANGE SIGNALS AND UPPER JET PATTERNS SUGGEST A FLATTENING OF THE MEAN STEERING FLOW REGIME ACRS MUCH OF THE CONUS AS THE WEEKEND PROGRESSES. EMBEDDED RIDGE RIDING/DAMPENING WAVE AND SOME LLVL BAROCLINIC TIGHTENING MAY COMBINE TO BRING MORE RAIN CHANCES TO THE REGION BY LATE SAT NIGHT OR NEXT SUNDAY. ..12.. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 700 AM CDT MON APR 28 2014 CIGS WERE LOWERING TO IFR NORTH OF A STATIONARY FRONT REACHING ACROSS SOUTHERN IOWA INTO CENTRAL ILLINOIS EARLY THIS MORNING. STRONG EASTERLY WINDS NORTH OF THIS BOUNDARY WILL CONTINUE THROUGH MUCH OF THE DAY AT CID...MLI...AND DBQ. THE IFR CONDITIONS DUE TO THE LOW CIGS AND LIGHT FOG SHOULD IMPROVE TO MVFR BY MID MORNING AT THESE SITES...WHILE BRL REMAINS VFR. THIS AFTERNOON...ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED TO LIFT THROUGH THE REGION. LATEST FORECASTS HAVE THIS HANDLED WITH A TEMPO GROUP AT BRL...WHILE LOWER CONFIDENCE TIMING AND COVERAGE AFFECTING THE OTHER TERMINALS WILL MAINTAIN PROB30 WORDING. WINDS WILL DIMINISH TONIGHT AND VEER A BIT MORE SOUTHEASTERLY AS THE FRONT TRIES TO LIFT NORTH. THIS NORTHWARD SHIFT SHOULD RESULT IN MVFR TO VFR CONDITIONS AT BRL AND MLI...WHILE CID AND DBQ LIKELY LOWER TO IFR. && .HYDROLOGY... ISSUED AT 357 AM CDT MON APR 28 2014 THE FLOOD WATCH FOR AREA RIVERS AND STREAMS CONTINUES TODAY AND THIS EVENING. THE THREAT OF FLOODING ON AREA TRIBUTARIES AND THE MISSISSIPPI RIVER WILL INCREASE AS THE WEEK PROGRESSES WITH A ACCUMULATIVE EFFECT OF SEVERAL RAIN EVENTS...INCLUDING THIS PAST SUNDAY EVENING/S HEAVY RAIN...THEN MORE LOCALIZED HEAVY RAIN POSSIBLE THIS AFTERNOON AND EVENING. LATEST THINKING SUGGESTS WIDESPREAD RAINFALL AMOUNTS OF 1 TO 4 INCHES WILL FALL OVER MUCH OF THE FORECAST AREA BY WEDNESDAY...INCLUDING THE RAINFALL FROM YESTERDAY AND LAST NIGHT. SINCE THE PRECIPITATION WILL OCCUR OVER AN EXTENDED PERIOD OF TIME...THE THREAT OF FLASH FLOODING WILL BE LOW. HOWEVER...RIVER FLOODING IS EXPECTED WITH SEVERAL OF THE AREA TRIBUTARIES AND THE MISSISSIPPI RIVER POSSIBLY SEEING AT LEAST MINOR TO MODERATE FLOODING BY THE MIDDLE OF THE WEEK. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...FLOOD WATCH THROUGH THIS EVENING FOR BENTON-BUCHANAN-CEDAR- CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-JACKSON- JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-MUSCATINE- SCOTT-VAN BUREN-WASHINGTON. IL...FLOOD WATCH THROUGH THIS EVENING FOR BUREAU-CARROLL-HANCOCK- HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE. MO...FLOOD WATCH THROUGH THIS EVENING FOR CLARK-SCOTLAND. && $$ UPDATE...08 SYNOPSIS...11 SHORT TERM...11 LONG TERM...12 AVIATION...11
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
425 PM EDT MON APR 28 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 425 PM EDT MON APR 28 2014 19Z SFC ANALYSIS SHOWS THE DEEP AREA OF LOW PRESSURE SPINNING OVER THE CENTRAL PLAINS. THIS SYSTEM/S WARM FRONT IS LAID OUT TO THE EAST JUST NORTH OF THE OHIO RIVER. THIS PLACES EAST KENTUCKY WELL INTO TO THE BROAD WARM SECTOR AND THUS RIPE FOR PERIODS OF SHOWERS AND THUNDERSTORMS. EARLIER SUNSHINE IN THE FAR EAST LED TO WARMER TEMPERATURES AND THIS IS HELPING STORMS SUSTAIN THEMSELVES NEAR THE VIRGINIA BORDER. MEANWHILE...MUCH COOLER TEMPERATURES IN THE REST OF THE CWA...DUE TO THE COLD POOL FROM THE EARLIER MCS TO THE WEST AND MORE EXTENSIVE CLOUD COVER...HAS KEPT THE CONVECTION TAME THERE...FOR NOW. DEWPOINTS REMAIN IN THE UPPER 50S TO LOWER 60S THROUGHOUT THE AREA WHILE THE WINDS ARE RATHER VARIABLE WITH OCCASIONAL SOUTH TO SOUTHWEST GUSTS TO 20 KTS...OUTSIDE OF STORMS. THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE DEEP UPPER LOW TRANSITIONING INTO THE MID MISSISSIPPI VALLEY TONIGHT AND SPREADING WAVES OF ENERGY CLUSTERS OVER EAST KENTUCKY AS IT DOES SO. THE BROAD CLOSED LOW THEN LIFTS NORTH INTO THE WESTERN GREAT LAKES LATER TUESDAY WHILE ONE LAST BATCH OF ENERGY RIDES THROUGH KENTUCKY DURING THE NIGHT. GIVEN THE MODEL AGREEMENT...HAVE FOLLOWED A BLEND WITH A LEAN TOWARD THE NAM12 AND HRRR FOR THE NEAR TERM DETAILS. SENSIBLE WEATHER WILL FEATURE PERIODS OF SHOWERS AND THUNDERSTORMS THROUGH THE SHORT TERM PORTION OF THE FORECAST. EACH NEW CLUSTER WILL HAVE A CHANCE TO BECOME SEVERE DEPENDING ON THE INSTABILITY LEFT BEHIND BY EARLIER STORMS AND CLEARING THAT CAN TAKE PLACE DURING THE DAYLIGHT HOURS. THIS WAS WHAT SET UP THE STORMS FOR FAR EAST KENTUCKY THIS AFTERNOON. EXPECT THESE TO CLEAR OUT OVER THE NEXT HOUR OR SO. ABOUT THAT TIME...THE NEXT ROUND OF STORMS SHOULD BE DEVELOPING IN SOUTH CENTRAL KENTUCKY AND WORKING TO MOVE NORTHEAST INTO EAST KENTUCKY LATER IN THE EVENING. STORMS WILL CONTINUE THROUGH THE NIGHT AS THE SET UP REMAINS INTACT. THE ACTUAL COVERAGE AND TIMING OF THESE LATER EVENTS WILL BE PARTIALLY DEPENDENT ON THE EARLIER EVOLUTION SO IT BECOMES HARDER TO PIN POINT. DO EXPECT THIS OVERNIGHT WAVE OF STORMS TO MOVE ON THROUGH TOWARDS DAWN AND EARLY TUESDAY MORNING IN FAR EASTERN PARTS OF THE STATE. ISOLATED TRAINING AND HEAVY RAINS WILL BE POSSIBLE THROUGH THE NIGHT...POSSIBLY RESULTING IN A FLASH FLOOD THREAT. THIS WILL CONTINUE TO BE HIGHLIGHTED IN THE HWO AND SPS. AFTER A MIDDAY LULL ON TUESDAY...LOW TOPPED STORMS SHOULD DEVELOP ACROSS EAST KENTUCKY BY LATE AFTERNOON WITH A CONTINUING POTENTIAL TO BE SEVERE...INCLUDING A SLIGHT TORNADO THREAT DUE TO FAVORABLE WIND SHEAR IN THE LOW LEVELS. THE MORE SUNSHINE THAT MANAGES TO OCCUR DURING THE DAY TUESDAY WILL PLAY INTO HOW STRONG THE STORMS COULD BECOME. THE SYSTEM/S COLD FRONT WILL SWEEP THROUGH LATER THAT NIGHT AND SHOULD END THE RISK FOR SEVERE WEATHER AND ALSO WIND DOWN THE THUNDER CHANCES. USED THE CONSSHORT AS A STARTING POINT FOR THE GRIDS THROUGH THE NEXT 24 HOURS WITH THE CONSALL THEREAFTER. MADE ONLY MINOR ADJUSTMENTS TO THE NUMBERS MAINLY TO CAPTURE THE CURRENT CONDITIONS AND TRENDS. AS FOR POPS...ENDED UP ON THE HIGH SIDE OF ALL GUIDANCE THROUGH THE FORECAST. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 330 PM EDT MON APR 28 2014 MODELS REMAIN IN GOOD AGREEMENT WITH THE EVOLUTION OF THE UPPER AIR PATTERN THROUGH THE MIDDLE AND END OF THE WEEK. THE LARGE UPPER LOW OVER THE UPPER MS VALLEY WILL MAKES ITS WAY INTO THE GREAT LAKES REGION BY THURSDAY...AND THEN ON INTO CANADA BY FRIDAY. AFTER THIS THERE WILL BE OCCASIONAL SHORT WAVE TROUGHS PASSING BY AS A MEAN LONG WAVE TROUGH REMAINS OVER THE EASTERN PART OF THE U.S. INTO EARLY NEXT WEEK. IT DOES APPEAR THE FLOW WILL BE SLOWLY DEAMPLIFYING THOUGH. HIGHER RAIN AND THUNDERSTORMS CHANCES WILL LINGER INTO THE DAY WEDNESDAY...MAINLY IN THE EASTERN PART OF THE FORECAST AREA. THE DEEPER MOISTURE AND FORCING WILL BE EXITING THE AREA ON WEDNESDAY...BUT MAINLY DIURNAL SHOWER CHANCES WILL LINGER INTO THE WEEKEND. WITH A MEAN TROUGH OVER THE AREA TEMPERATURES WILL ALSO AVERAGE BELOW NORMAL FOR THE END OF THE WEEK AND INTO THE WEEKEND. TEMPERATURES WILL BE WARMING LATE IN THE WEEKEND AND INTO EARLY NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 215 PM EDT MON APR 28 2014 VFR CONDITIONS WILL CONTINUE FOR MUCH OF THE AREA THIS AFTERNOON... OUTSIDE OF A ZONE OF STRONGER STORMS FOR THE NEXT FEW HOURS LOCATED SOUTH AND EAST OF THE TAF SITES. THE NEXT STRONG TO SEVERE CLUSTER OF SHOWERS AND STORMS MOVE IN AROUND 00Z. HAVE GONE WITH MVFR TO IFR CEILINGS AND VISIBILITY THROUGH MUCH OF THE NIGHT AND INTO EARLY TUESDAY MORNING WITH THIS OVERNIGHT ROUND OR TWO OF STORMS. CONDITIONS IMPROVE TEMPORARILY INTO MIDDAY TUESDAY WITH VFR CIGS AND VIS EXPECTED FOR A TIME. WINDS WILL BE OUT OF THE SOUTH FOR MUCH OF THE PERIOD WITH GUSTS UP TO 20 KTS POSSIBLE...OUTSIDE OF THUNDERSTORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GREIF LONG TERM...SBH AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
423 PM EDT MON APR 28 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 423 PM EDT MON APR 28 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER LEVEL TROUGH FROM THE NRN ROCKIES TO THE CENTRAL PLAINS AND MID MS VALLEY. DOWNSTREAM A RIDGE EXTENDED FROM THE MID ATLANTIC THROUGH THE ERN LAKES TO WRN HUDSON BAY. AT THE SFC...GUSTY EAST WINDS PREVAILED AS A RESULT OF A TIGHT PRES GRADIENT BETWEEN STRONG HIGH PRES OVER HUDSON BAY AND A LOW OVER ERN NEBRASKA. A BAND OF RAIN OVER NRN WI SUPPORTED BY 295K-300K ISENTROPIC LIFT WAS MAKING VERY SLOW PROGRESS IN LIFTING TO THE NORTH AS IT ENCOUNTERS IT ENCOUNTERS DRY EASTERLY FLOW (BELOW 800 MB) TO THE NORTH AND EAST...PER 12Z APX SOUNDING. SOME PCPN MAY DEVELOP ALONG THE WI BORDER THIS EVENING BUT SINCE IT SHOULD BE RELATIVELY LIGHT...MAINLY SPRINKLES...ONLY CHANCE POPS WERE INCLUDED. AS THE MID LEVEL LOW WOBBLES TO THE NORTHEAST AND A SHORTWAVE LIFTS NORTH INTO UPPER MI...EXPECT WIDESPREAD PCPN TO SPREAD INTO THE SOUTH LATE TONIGHT AND ACROSS THE REST OF THE CWA TUE MORNING. THE PCPN IS EXPECTED TO TAPER OFF FROM SSE TO NNW BY MID TO LATE AFTERNOON. THE REGION WILL FALL UNDER THE TROWAL REGION NORTH OF THE MID/UPPER LOW...PER MODELS 310-320 THETA-E LAYER. ALTHOUGH MOST AREAS SHOULD SEE QPF AMOUNTS IN THE 0.50 TO .75 INCH RANGE...THE STRONGEST LIFT AND MOISTURE INFLOW IS EXPECTED OVER THE SE CWA WHERE QPF COULD EXCEED AN INCH THROUGH TUE. UPSLOPE NE FLOW INTO N CNTRL UPPER MI COULD ALSO SUPPORT RELATIVELY HIGHER PCPN AMOUNTS. UNCERTAINTY REMAINS WITH THE PCPN TYPE OVER THE HIGHER TERRAIN OF THE WRN HALF OF UPPER MI. THE 12Z NAM LOW LEVEL THICKNESS AND WET-BULB ZERO HEIGHTS SUGGEST THAT SNOW MAY BE THE PREDOMINATE PCPN TYPE OVER THE INTERIOR...AND ESPECIALLY OVER THE HIGHER TERRAIN OF THE WRN THIRD TOWARD IWD. EVEN WITH THE HIGH QPF AMOUNTS...VERY LOW SLR VALUES AND RELATIVELY WARM ROAD SURFACES SHOULD MINIMIZE ANY ACCUMULATIONS WITH SNOW AMOUNTS ONLY TO AROUND AN INCH EXPECTED ON GRASSY OR SNOW COVERED AREAS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 423 PM EDT MON APR 28 2014 MUCH OF THE LONG TERM FORECAST WILL DEAL WITH THE UPPER LOW CURRENTLY OVER THE CENTRAL CONUS THAT WILL GRADUALLY LIFT NORTHEAST THROUGH MUCH OF THE REST OF THE WORK WEEK. THE STRONGEST WAVE OF PRECIPITATION WILL MOVE NORTH THROUGH THE AREA ON TUESDAY AND SHOULD BE SITUATED OVER WESTERN LAKE SUPERIOR AND THE WESTERN THIRD OF THE U.P. AT THE START OF THE LONG TERM PERIOD. THIS WILL CONTINUE TO ROTATE NORTHWEST TUESDAY NIGHT AND LEAD TO A LITTLE BIT OF A BREAK ON THE PRECIPITATION FOR TUESDAY EVENING OVER THE CENTRAL/EAST. AS THE SURFACE LOW MOVES UP INTO THE GREAT LAKES REGION...A MID LEVEL TROUGH WILL SLIDE NORTH THROUGH THE AREA LATE TUESDAY NIGHT THROUGH WEDNESDAY. THINK THE HEAVIEST PRECIP WOULD BE OVER THE EAST THIRD...BUT STILL WOULD EXPECT SCATTERED/NUMEROUS SHOWERS OVER THE WEST/CENTRAL. BETTER DEEP MOISTURE SHIFTS OVER THE WESTERN LAKE AFTER THAT...AND WILL LIKELY LEAD TO A MORE SCATTERED NATURE TO THE SHOWERS. THIS WILL CONTINUE THROUGH THE FIRST PART OF THE WEEKEND AS THE AS THE UPPER LOW SPINS AND BROADENS/WEAKENS. THUS...WILL CONTINUE TO SHOW A GRADUAL DECREASING TREND TO THE POPS. WITH THE POTENTIAL FOR WEAK DISTURBANCES ROTATING THROUGH...THERE MAY BE PERIODS WHERE POPS NEED TO BE BUMPED UP...BUT PINNING THOSE DOWN AT THIS TIME IS TOO DIFFICULT. AS FOR PRECIP TYPE...SHOULD BE ENOUGH WARM AIR WRAPPING IN DURING THE DAY TOMORROW TO CHANGE THE PRECIP OVER TO RAIN OVER MUCH OF THE AREA BY TUESDAY EVENING (EXCEPT FOR A LINGERING MIX NEAR IRONWOOD). THE WARM AIR CONTINUES TO MOVE WEST AROUND THE LOW (REMAINING AROUND 2-4C AT 850MB) THROUGH WEDNESDAY EVENING AND WILL KEEP EVERYTHING AS RAIN. THEN AS THE FLOW STARTS TO BECOME A LITTLE MORE NORTHERLY ON WEDNESDAY NIGHT AND INTO THURSDAY...TEMPERATURES ALOFT BEGIN TO COOL FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA AND COULD LEAD TO A TRANSITION TO TO MORE OF A RAIN/SNOW MIX HEADING INTO THURSDAY/FRIDAY. OPTED TO FOLLOW THE GENERAL IDEA SHOWN BY THE 1000-850MB THICKNESS AND WETBULB0 HEIGHTS THROUGH THE FORECAST PERIOD SINCE IT WAS LARGELY DEALING WITH A NEAR SURFACE WARM LAYER. DID PUT IN SOME FOG FOR THE FAVORED UPSLOPE HIGHER TERRAIN LOCATIONS OF THE CENTRAL/NORTH-CENTRAL ON TUESDAY NIGHT INTO WEDNESDAY WITH THE FAVORABLE EASTERLY UPSLOPE FLOW OF MOIST AIR. ELSEWHERE...WOULD EXPECT IT TO BE JUST A LOW STRATUS DECK. ALL IN ALL...LOOKS TO BE A COOL/CLOUDY/SHOWERY PERIOD THROUGH THE FIRST HALF OF THE WEEKEND. UPPER TROUGH/LOW FINALLY SHIFTS EAST OF THE AREA FOR THE SECOND HALF OF THE WEEKEND...BUT MODELS DIFFER ON EVOLUTION OF THE UPPER LEVEL PATTERN AT THAT POINT. THE GENERAL IDEA IS FOR MORE ZONAL FLOW OR WEAK UPPER LEVEL RIDGING TO DEVELOP OVER THE NORTH-CENTRAL CONUS...WHICH SHOULD LEAD TO A LITTLE DRIER PERIOD THAN SEEN THIS WEEK. THERE ARE HINTS IN THE 12Z GEM/GFS/ECMWF THAT A WEAK DISTURBANCE WILL SHIFT EAST ACROSS THE AREA ON SUNDAY AND BRING SOME SHOWERS. OTHERWISE...MONDAY IS LOOKING LIKE IT MAY END UP DRY WITH THE WEAK UPPER RIDGE SHIFTING CLOSER TO THE AREA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 135 PM EDT MON APR 28 2014 VFR CONDITIONS WILL PREVAIL UNTIL LATE TONIGHT. THERE COULD BE SOME INTERMITTENT LIGHT RAIN/SPRINKLES AT KIWD THIS MORNING BUT OTHERWISE MID CLOUDS AND VFR CONDITIONS WILL PREVAIL. INCREASING MOISTURE AHEAD OF A WARM FRONT WILL BRING AN INCREASING CHANCE OF RAIN RAIN LATE TONIGHT AT ALL TAF SITES AS CIGS LOWER TO MVFR. A MIX OF RAIN AND SNOW WILL MOVE IN DURING THE MORNING WITH CIGS LIKELY LOWERING INTO THE IFR RANGE WITH VSBY REMAINING MVFR. THE BEST CHANCE FOR SNOW WILL BE OVER THE WEST TOWARD CMX AND ESPECIALLY IWD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 423 PM EDT MON APR 28 2014 EAST TO NORTHEAST GALES ARE EXPECTED TO CONTINUE OVER THE WRN PORTION OF LAKE SUPERIOR THROUGH TUE INTO TUE EVENING AS A RESULT OF THE STRONG PRES GRADIENT BTWN A DEEP LOW OVER ERN NEBRASKA AND A STRONG HIGH OVER HUDSON BAY. ENE GALES TO 35 KNOTS ARE ALSO POSSIBLE CENTRAL LAKE SUPERIOR TUE BUT SINCE THERE WAS STILL UNCERTAINTY WHETHER THE 30 KNOTS WINDS WILL INCREASE TO GALES...THE WATCH WAS RETAINED FOR THIS LOCATION. THE WINDS WILL DIMINISH TUE EVENING AS THE LOW LIFTS TO THE NORTH TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER WINDS TO 30 KNOTS ARE STILL EXPECTED UNTIL LATE TUE NIGHT. WINDS ARE EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED INTO FRI AS THE LOW FILLS AND REMAINS NEAR UPPER MICHIGAN. && .HYDROLOGY... ISSUED AT 423 PM EDT MON APR 28 2014 RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER NEAR NAHMA JUNCTION. AT LEAST THROUGH TUESDAY MORNING THESE RIVERS ARE NOT EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS WILL START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF HIGHER QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK. REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR LSZ264>266. GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ TUESDAY FOR LSZ162-263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...JLB MARINE...JLB HYDROLOGY...SRF/TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
136 PM EDT MON APR 28 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 511 AM EDT MON APR 28 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER LEVEL TROUGH FROM THE NW CONUS THROUGH THE CENTRAL PLAINS WITH A CLOSED LOW OVER NEBRASKA. DOWNSTREAM A RIDGE EXTENDED FROM THE SE CONUS THROUGH WRN LAKES INTO MANITOBA. AT THE SFC...A BRISK ERLY FLOW PREVAILED THROUGH THE NRN LAKES BETWEEN HIGH PRES OVER HUDSON BAY AND A DEEP LOW OVER ERN NEBRASKA. ISENTROPIC ASCENT AS NOTED ON THE 295K SFC HAS PRODUCED SEVERAL BANDS OF LIGHT PCPN OVER UPPER MI THIS MORNING BUT THIS PCPN HAS FALLEN MAINLY AS JUST SPRINKLES/FLURRIES AS IT ENCOUNTERS VERY DRY AIR BELOW 750 MB. TODAY...MODELS CONSISTENT SHOWING SYSTEM OVER ERN NEBRASKA STALLING AND BEGINNING TO OCCLUDE TODAY. MODELS SHOW WEAKENING ISENTROPIC ASCENT OVER UPR MI AND A LACK OF 850-700 MB MOISTURE ADVECTION INTO THE REGION. THIS FACT ALONG WITH MID-LVL RDG GENERALLY STAYING IN PLACE SHOULD KEEP MUCH OF THE CWA DRY TODAY. INCREASING 850-700 MB MOISTURE ADV AND ISENTROPIC ASCENT COULD BRING IN A BETTER CHC OF RAIN TOWARD 00Z THIS EVENING OVER MAINLY FAR SCNTRL CWA. TONIGHT...MODELS SHOW MORE SUBSTANTIAL SHORTWAVE LOBE ROTATING NORTHWARD AHEAD OF PLAINS CLOSED LOW WHICH IN TURN WILL PROPEL 850 MB WARM FRONT NORTHWARD INTO THE SE CWA LATE TONIGHT. INCREASING ISENTROPIC ASCENT AND 850-700 MB MOISTURE ADVECTION SPREADING IN FROM THE SSE AHEAD OF THE WARM FRONT WILL BRING INCREASING RAIN CHCS INTO SCNTRL CWA THIS EVENING SPREADING INTO THE REST OF THE SE HALF OF THE CWA OVERNIGHT TONIGHT. THICKNESS VALUES AND SOUNDINGS SUGGEST SNOW MAY MIX WITH RAIN OVER NCNTRL AND NW CWA LATE TONIGHT BUT PCPN SHOULD BE LIGHT THAT ANY SNOW AMTS WILL HAVE LITTLE IMPACT ON TRAVEL. MODEL QPF INDICATES SCNTRL CWA COULD SEE FROM .25 TO PERHAPS .75 OF AN INCH OF RAINFALL TONIGHT WHICH WILL ADD TO RUNOFF FOR AREA STREAMS AND RIVERS INTO MIDWEEK. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 358 AM EDT MON APR 28 2014 FOCUSED ATTENTION ON TUE-WED NIGHT TIME FRAME AS MOST SIGNIFICANT PRECIP IS EXPECTED DURING THAT TIME. THE SETUP FOR MID WEEK IS QUITE INTERESTING ACROSS THE CONUS AS A DEEP CLOSED UPPER LOW IS OVER THE CENTRAL CONUS...BORDERED ON THE W...N AND E BY AMPLIFIED UPPER RIDGING. ALSO...AT THE START OF THE LONG TERM /12 TUE/...THE UPPER LOW WILL BE ABSORBING A WEAK UPPER LOW THAT ORIGINATED OVER QUEBEC. THE SYSTEM WILL BE QUITE WRAPPED UP...WITH GREAT MOISTURE TRANSPORT FROM BOTH THE GULF OF MEXICO AND THE ATLANTIC THAT FOCUSES OVER THE LOWER GREAT LAKES BEFORE WRAPPING W ACROSS THE CWA AND EVENTUALLY TO THE W OF THE LOW /WHICH IS OVER IA AT 12Z TUE/. PRECIP TUE WILL BE PRIMARILY FORCED BY 50-60KT 900-700MB WINDS...RESULTING IN GOOD MOISTURE TRANSPORT IN THIS LAYER AS WELL AS STRONG ISENTROPIC ASCENT AS ISENTROPIC SURFACES INCREASE IN HEIGHT BY AROUND 1KM FROM UPSTREAM TO DOWNSTREAM ACROSS THE CWA. PWAT VALUES WILL BE 0.75-1.00 INCHES...OR GENERALLY 150-200 PERCENT OF NORMAL. ANOTHER SIGNIFICANT FORCING MECHANISM IS A SHORTWAVE THAT MODELS SHOW MOVING ACROSS THE CWA TUE...WHICH LEADS TO STEEP 700-500MB LAPSE RATES OF JUST OVER 7C/KM. ADDITIONALLY...THE LEFT EXIT REGION OF AN UPPER JET WILL BE ACROSS THE CWA. ALL THESE INGREDIENTS COME TOGETHER TO PRODUCE SIGNIFICANT QPF AMOUNTS FROM THE MODELS LATE MON NIGHT INTO TUE. THE MOST PRECIP SHOULD FALL NEAR LAKE MICHIGAN WHERE THE BEST FORCING AND MOISTURE IS EXPECTED. EVEN THE LOWER RES MODELS /THAT TYPICALLY DO NOT PERFORM AS WELL IN THIS TYPE OF SITUATION/ HAVE UP TO AN INCH OF QPF NEAR LAKE MICHIGAN...WHILE THE NAM HAS THE MOST QPF AT 2.25 INCHES. WILL GO WITH A CONSENSUS APPROACH OF GFS/ECMWF AND REGIONAL GEM /WHICH HAS UP TO 1.85 INCHES/...WHICH INCORPORATES MON NIGHT /SHORT TERM/. THE ECMWF/GFS HAVE THE BEST PRECIP LATE MON NIGHT INTO TUE MORNING...WHILE THE NAM HAS THE BEST PRECIP ON TUE. THE REGIONAL GEM IS BETWEEN THE NAM AND GFS/ECMWF. A COMPLICATING FACTOR TO THIS TIME FRAME IS THAT MODEL TEMP PROFILES FAVOR PRECIP TO BE SNOW OVER WRN UPPER MI AND RAIN NEAR LAKE MICHIGAN AND E...WITH A MIX BETWEEN. DUE TO SFC TEMPS BEING NEAR OR ABOVE FREEZING AND STRONG SOLAR EFFECTS THIS TIME OF YEAR...ACCUMULATIONS ON PAVED SURFACES SHOULD BE MINIMAL...BUT GRASSY SURFACES OVER THE HIGHER TERRAIN OF WRN UPPER MI COULD SEE 2-3 INCHES OF SNOW. GIVEN VERY MINIMAL EXPECTED IMPACTS TO TRAVEL...WILL CONTINUE TO NOT MENTION SNOW IN THE HWO. DEPENDING ON EXACT PRECIP AMOUNTS...COULD SEE SOME SIGNIFICANT RISES ON AREA RIVERS. ANOTHER SHOT AT GOOD ISENTROPIC ASCENT AND A STRONG SHORTWAVE ARE SHOWN BY MODELS FOR WED AS THE UPPER LOW CONTINUES TO WEAKEN AND BEGINS MOVING NE TOWARD THE CWA. SIGNALS FOR PRECIP AMOUNTS AND TRENDS ARE A LOT MORE MUDDLED ON WED INTO WED NIGHT AS THE CWA WILL BE MORE REMOVED FROM THE BEST MOISTURE TRANSPORT...WHICH WILL BE MORE FOCUSED E AND N OF THE CWA. THINK THAT MUCH OF THE CWA WILL SEE PRECIP...WITH POTENTIAL FOR UP TO AN INCH OF ADDITIONAL PRECIP DURING THIS TIME PERIOD. USED A BROAD CONSENSUS OF GUIDANCE DURING THIS PERIOD. THE UPPER LOW WILL CONTINUE TO WEAKEN AND MOVE SLOWLY NE INTO LATE WEEK BEFORE ADDITIONAL UPPER LEVEL ENERGY MOVES INTO THE REGION LATE THIS WEEK INTO THE WEEKEND...LEADING TO CONTINUED WET WEATHER...BUT AMOUNTS WILL BE LOWER THROUGH THE REST OF THE WEEK. USED A CONSENSUS OF GUIDANCE FOR THIS PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 135 PM EDT MON APR 28 2014 VFR CONDITIONS WILL PREVAIL UNTIL LATE TONIGHT. THERE COULD BE SOME INTERMITTENT LIGHT RAIN/SPRINKLES AT KIWD THIS MORNING BUT OTHERWISE MID CLOUDS AND VFR CONDITIONS WILL PREVAIL. INCREASING MOISTURE AHEAD OF A WARM FRONT WILL BRING AN INCREASING CHANCE OF RAIN RAIN LATE TONIGHT AT ALL TAF SITES AS CIGS LOWER TO MVFR. A MIX OF RAIN AND SNOW WILL MOVE IN DURING THE MORNING WITH CIGS LIKELY LOWERING INTO THE IFR RANGE WITH VSBY REMAINING MVFR. THE BEST CHANCE FOR SNOW WILL BE OVER THE WEST TOWARD CMX AND ESPECIALLY IWD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 511 AM EDT MON APR 28 2014 EAST TO NORTHEAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE DEEPENS OVER THE PLAINS. EXPECT ENE GALES TO 35KTS OVER MUCH OF WRN LAKE SUPERIOR INTO TUE MORNING. THERE IS ALSO A CHANCE FOR ENE GALES TO 35 KNOTS OVER CENTRAL LAKE SUPERIOR FOR LATE TONIGHT INTO TUE SO HAVE ISSUED A GALE WATCH FOR LSZ264-266 WINDS SHOULD GRADUALLY DIMINISH LATE TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE EVENING. WINDS ARE EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED INTO FRI AS THE LOW FILLS AND REMAINS NEAR UPPER MICHIGAN. && .HYDROLOGY... ISSUED AT 358 AM EDT MON APR 28 2014 RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER NEAR NAHMA JUNCTION. AT LEAST THROUGH TONIGHT THESE RIVERS ARE NOT EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS WILL START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF HIGHER QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK. REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR LSZ264>266. GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ TUESDAY FOR LSZ162-263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...TITUS AVIATION...JLB MARINE...VOSS HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1258 PM EDT MON APR 28 2014 LATEST UPDATE... UPDATE .SYNOPSIS... ISSUED AT 325 AM EDT MON APR 28 2014 AN EXPANSIVE AND STRONG SYSTEM CENTERED ACROSS THE CENTRAL PLAINS STATES WILL DRIVE RAINFALL INTO THE AREA AHEAD OF AN ASSOCIATED FRONTAL SYSTEM TO OUR SOUTH. COOL AND WINDY CONDITIONS CAN BE EXPECTED TODAY WITH AN INCREASING CHANCE OF RAIN. RAIN WILL CONTINUE INTO EARLY TUESDAY BEFORE THE RAIN MOVES NORTH AND A SHORT PERIOD OF WARMER AIR MOVES IN ACROSS THE AREA. ADDITIONAL SHOWERS AND STORMS WILL BE POSSIBLE TUESDAY AND WEDNESDAY AS ADDITIONAL WAVES OF LOW PRESSURE MOVE THROUGH THE AREA. COOLER CONDITIONS WILL THEN RETURN FOR LATE THIS WEEK ALONG WITH A CONTINUED CHANCE OF RAIN SHOWERS. && .UPDATE... ISSUED AT 1256 PM EDT MON APR 28 2014 FORECASTS WILL BE UPDATED TO ACCOUNT FOR LESS RAIN THIS AFTERNOON. THE BAND OF RAIN CONTINUES TO DIMINISH...SO I LOWERED POPS. SOME BREAKS IN THE CLOUDS SHOWING UP AS WELL...THUS I FEATURED LESS CLOUD COVER AS WELL. WITH ADDED HEATING...MIXING HEIGHTS WILL INCREASE. THUS IT WILL REMAIN WINDY THROUGH THE AFTERNOON. UPDATE ISSUED AT 1056 AM EDT MON APR 28 2014 WILL KEEP THE WIND ADVISORY GOING. WHILE OBS ARE MOSTLY BELOW CRITERIA...THE MODELS SUGGEST MIXING HEIGHTS WILL INCREASE EARLY THIS AFTERNOON AS THE LOW LEVEL JET STRENGTHENS. WE ARE ALSO SEEING SOME POWER OUTAGES SHOWING UP ON THE CONSUMERS WEBSITE. THE BAND OF SHOWERS MOVING IN FROM THE SOUTH CONTINUES TO WEAKEN. WHILE MOST LOCATIONS WILL SEE SOME PRECIPITATION...WHAT DOES FALL TH IS AFTERNOON SHOULD BE LIGHT. SO I FEATURES LIGHT RAIN SHOWERS...AND TONED BACK THE THUNDER WORDING. MODELS SHOWING NO INSTABILITY THROUGH 00Z TUE. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 325 AM EDT MON APR 28 2014 THE MAIN CHANGE WITH THIS FCST PACKAGE IS TO EXPAND THE WIND ADVISORY TO THE EAST THROUGH THE REMAINDER OF THE CWFA FOR TODAY. OTHERWISE...THE FCST REMAINS MAINLY ON TRACK WITH A SLIGHTLY SLOWER TREND TO THE RAIN MOVING IN FOR TODAY. REGARDING THE EXPANSION OF THE WIND ADVISORY FIRST...WINDS REMAIN RATHER BRISK AND THIS EARLY MORNING HOUR ACROSS THE CWFA. SOME GUSTS OF AROUND 30 KNOTS ARE ALREADY OCCURRING THIS MORNING...AND THIS WILL ONLY INCREASE DURING THE DAYLIGHT HOURS AS THE GRADIENT TIGHTENS MORE AND AS DIURNAL MIXING WILL HELP TO BRING SOME OF THE STRONGER WINDS DOWN FROM ALOFT. IT SEEMS THAT 40 KNOTS SHOULD BE PRETTY EASY TO MIX DOWN...EVEN IN A WAA PATTERN. AS FAR AS THE RAINFALL IS CONCERNED...THE TREND OVER THE PAST 24 HOURS IS THAT OF A SLOWER ONE WITH THE FEED OF DRY AIR COMING IN ON THE BRISK ERLY WINDS AND HELPING TO DIMINISH MOST ALL PCPN TRYING TO MOVE IN. THE UPPER RIDGE AXIS THAT IS ONLY SLOWLY CRAWLING EASTWARD ACROSS THE CWFA IS FAR ENOUGH EAST AT THIS TIME THAT ENOUGH MOISTURE TRANSPORT IS OCCURRING AND A COUPLE OF SPRINKLES/LIGHT SHOWERS ARE OCCURRING ACROSS THE FAR SW CORNER OF THE CWFA. WE DO EXPECT THAT PCPN WILL BE ON THE INCREASE TODAY FROM SW TO NE AS THE UPPER LOW ROTATES A LITTLE CLOSER. THUNDER IS STILL POSSIBLE ACROSS THE FAR SOUTH THIS AFTERNOON AS SLIGHTLY NEGATIVE ELEVATED LI/S MOVE UP INTO THE AREA. SEVERE WX IS NOT EXPECTED AT THIS TIME WITH NO SFC INSTABILITY EXPECTED THROUGH TONIGHT. THE BEST THREAT OF RAIN SHOWERS AND STORMS LOOKS TO COME THIS EVENING AND INTO THE OVERNIGHT HOURS. THE BEST MOISTURE AXIS PASSES FROM SOUTH TO NORTH DURING THIS TIME FRAME...OUT AHEAD OF THE OCCLUDED FRONT. WE CONTINUE TO EXPECT LITTLE THREAT OF SEVERE STORMS TONIGHT ONCE AGAIN AS THE INSTABILITY WILL ONCE AGAIN BE ELEVATED. THE RAIN CHANCES WILL THEN DIMINISH LATE TONIGHT AND EARLY TUE MORNING AS THE MOISTURE TRANSPORT AND LLJ PEEL OFF TO THE EAST OF THE STATE. WE CONTINUE TO LOOK FOR A BRIEF WARM UP FOR THE DAY ON TUE WITH 70 DEGREE TEMPERATURES LOOKING MORE LIKELY. THE FRONT WILL BE NEAR THE SRN STATE BORDER AT 12Z ON TUE. THE UPPER LOW COMING IN FROM THE WEST WILL PUSH THE FRONT NORTH THROUGH THE AREA. EVEN THOUGH IT WILL NOT BE THE TRUE WARM SECTOR...H850 TEMPS ARE STILL VERY MILD...AND WILL WE TAP THAT WARMTH AS THE DRY SLOT MOVES IN AND WE GET SOME SUN. H850 TEMPS AROUND +10 C WILL SUPPORT MANY LOCATIONS HITTING 70. IT DOES LOOK LIKE LATE IN THE AFTERNOON WE WILL SEE CONVECTION TRY TO FIRE OVERHEAD AS A WAVE ROTATES AROUND THE UPPER LOW AND MOVES TOWARD THE AREA. THERE IS SOME CONCERN WITH CONVECTION FIRING ON TUE AFTERNOON AS STRONG JET STREAM WINDS WILL STILL BE OVERHEAD ACROSS SE LOWER. THIS WILL PROVIDE FOR GOOD SHEAR IN THE DEEP LAYER. MUCH BETTER INSTABILITY /LI/S OF -6 TO -8C/ WILL BE FOUND FURTHER SE ALSO. WE STAY RELATIVELY WARM THROUGH MOST OF WED AS THE LOW LEVEL COLD AIR DOES NOT COME IN UNTIL LATE WED AFTERNOON AND WED EVENING. THIS IS THE CASE AS THE UPPER LOW HELPS ANOTHER WAVE TOWARD THE AREA AND THE FLOW AHEAD OF IT WILL CONTINUE TO SUPPORT WARM TEMPS UNTIL THE LOW MOVES THROUGH LATE WED. SHOWERS AND STORMS WILL REMAIN POSSIBLE AHEAD OF THIS WAVE FOR TUE NIGHT AND WED. WE WILL LIKELY NOT REACH 70 AGAIN...BUT WE SHOULD BE WELL INTO THE 60S. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 325 AM EDT MON APR 28 2014 LITTLE QUESTION OCCASIONAL SHOWERS AND COOLER THAN NORMAL TEMPERATURES WILL PREVAIL THROUGH SATURDAY AS WE REMAIN ON THE CYCLONIC SIDE OF THE UPPER JET WITH A FAIR AMOUNT OF DEEP MOISTURE. SOME QUESTION ARISES WHAT HAPPENS FROM SUNDAY AND BEYOND SO I KEEP THE LOW CHANCE POP FOR SUNDAY BUT IT MAY BE WE ACTUALLY GET TO SEE THE SUN ONCE AGAIN BY SUNDAY AS THE UPPER JET MAY FINALLY LIFT NORTH OF LOWER MICHIGAN MY THEN. MODEL CONTINUE TO BE IN GOOD AGREEMENT WITH THE CLOSED UPPER LOW REMAINING IN PLACE INTO AS LEAST SATURDAY. THE 500 MB HEIGHT ANOMALIES ARE ON THE ORDER OF 2-3 STD BELOW NORMAL INTO SATURDAY OVER THE LOWER GREAT LAKES. 850 MB TEMPERATURES ARE 1 TO 2 STD BELOW NORMAL INTO SATURDAY. THE MODELS CONTINUE TO FEATURE THAT ARCTIC JET STREAK FEEDING INTO THE SYSTEM FRIDAY INTO SATURDAY. THAT WILL MAINTAIN THIS PATTERN INTO SATURDAY FOR SURE. FROM SUNDAY ON THERE IS A QUESTION OF WHETHER ANOTHER PACIFIC SYSTEM CAN BREAK THROUGH THE WESTERN RIDGE TO PUSH THIS PATTERN OUT OF THE WAY OR IF WE WILL CONTINUE TO SEE MORE IN A SERIES OF NORTHERN STREAM OF SYSTEMS. I KEEP LOW CHANCE POPS FOR SUNDAY JUST IN CASE THE LATER OCCURS. AS FOR THE SHOWERS WEDNESDAY NIGHT THROUGH SATURDAY AFTERNOON... GIVEN THE DEEP CYCLONIC FLOW...DEEP MOISTURE AND SATURATED DGZ PLUS SURFACE CONVERGENCE ALONG THE LAKE MICHIGAN SHORE AREAS INTO SATURDAY I HAVE TO BELIEVE WE WILL CONTINUE TO SEE LIGHT SHOWER THROUGH THIS ENTIRE PERIOD. I HAVE CONTINUED THE LIKELY POPS INTO FRIDAY AND HIGH CHANCE INTO SATURDAY. TEMPERATURES WILL BE BETWEEN 5 AND 10 DEGREES BELOW NORMAL THROUGH THIS PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 741 AM EDT MON APR 28 2014 OUR MAJOR QUESTION IS WHEN WILL THE RAIN ARRIVE AND MORE THAN THAT WHEN WILL THE MVFR/IFR CIGS/VSBY MOVE IN AS THE STORM TO OUR SOUTHWEST SLOWLY MOVES TOWARD THE REGION. THE HUDSON BAY HIGH CONTINUES TO FEED VERY DRY AIR FROM THE EAST AND IT WILL CONTINUE TO ERROD THE RAIN AS MOVES INTO SOUTHWEST MICHIGAN. THIS IS NOT TO SAY THERE WILL NOT BE SOME LIGHT RAIN SHOWERS BUT IT SEEMS THE BULK OF THE SIGNIFICANT RAIN WILL LARGELY STAY NEAR AND SOUTH OF INTERSTATE 94 TODAY (USING THE RAP13 MODEL AND HRRR ). I DID BRING THE SHOWERS INTO THE AZO...BTL AND JXN BY LATE MORNING BUT I DID NOT BRING THOSE SHOWERS INTO GRR...MKG AND LAN TILL LATE AFTERNOON... EVEN THEN VSBY SHOULD BE VFR FOR THE MOST PART. I PUT VCSH AT ALL THE TAF SITES DURING THE MID MORNING HOURS SINCE SHOWERS WILL BE AROUND BUT VERY LIGHT (MOSTLY SPRINKLES). THE MVFR CIGS/VSBY SHOULD REACH THE I-94 TAT SITES BY LATE AFTERNOON THEN SPREAD INTO THE I-96 SITES AFTER 00Z. ANY THUNDERSTORM ACTIVITY SHOULD HOLD OFF UNTIL TUESDAY. && .MARINE... ISSUED AT 1056 AM EDT MON APR 28 2014 GALE WARNING TO CONTINUE. SOME GUSTS OVER GALE FORCE ALREADY OBSERVED. WINDS LIKELY TO INCREASE AS THE LOW LEVEL JET STRENGTHENS AND MIXING HEIGHTS INCREASE. && .HYDROLOGY... ISSUED AT 241 PM EDT SUN APR 27 2014 I DOWNPLAYED THE QPF THROUGH TUE. THE DRY AIRMASS CURRENTLY IN PLACE SHOULD ACT TO DELAY THE ARRIVAL OF THE SHOWERS. MODELS ARE GENERALLY SHOWING A DIMINISHING TREND TO THE INITIAL BAND OF SHOWERS DURING THE DAY ON MONDAY. STILL LOOKS LIKE ENOUGH RAIN TO CAUSE RIVER RISES. ANOTHER BATCH OF RAIN TUE NIGHT INTO WED MAY BE HEAVY. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ037>040-043>046- 050>052-056>059-064>067-071>074. LM...GALE WARNING UNTIL 8 AM EDT TUESDAY FOR LMZ844>849. && $$ UPDATE...MJS SYNOPSIS...NJJ SHORT TERM...NJJ LONG TERM...WDM AVIATION...WDM HYDROLOGY...MJS MARINE...MJS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
412 PM CDT MON APR 28 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 410 PM CDT MON APR 28 2014 BIGGEST CONCERN IN THE SHORT TERM IS THE POTENTIAL FOR ACCUMULATING SNOW LATE TONIGHT THROUGH TUESDAY AS A DEFORMATION BAND OF PRECIP SETS UP SHOP OVER THE MPX AREA AND DOES NOT REALLY GO ANYWHERE UNTIL WEDNESDAY. SFC LOW AND VERTICALLY STACKED SYSTEM WAS CENTERED NEAR COLUMBUS... NEB TO THE WEST OF OMAHA. DURING THIS PERIOD...THIS LOW WILL REMAIN CUTOFF...WHICH MEANS IT WILL NOT BE GOING VERY FAR...MAKING IT TO ABOUT THE IA/IL/WI BORDER BY 00Z WED. THIS WILL LEAVE US WITHIN A WAA REGION TONIGHT...THAT WILL RATHER SEAMLESSLY TRANSITION INTO DEFORMATION PRECIPITATION FOR TUESDAY. AT THE START OF THIS PERIOD WE WILL HAVE A BRIEF RESPITE FROM THE PRECIP WORK ACROSS MOST OF THE MPX CWA...THIS IS IN RESPONSE TO A LOSS IN DEEP MOISTURE SHOWN BY THE GFS/NAM AND OTHER DETERMINISTIC MODELS THAT IS REFLECTED IN THE HI-RES MODELS BY A LACK OF PRECIPITATION GENERATION THROUGH ABOUT 6Z TONIGHT. HOWEVER...CONTINUED WAA AND MOISTURE TRANSPORT WILL QUICKLY START TO FILL IN THIS MOMENTARY BREAK THIS EVENING. FOR POP GRIDS...FOLLOWED THE HRRR/MPXWRF FOR TRYING TO TIME THE LOWER POPS ACROSS THE AREA... BEFORE BRINGING POPS BACK IN FROM EAST TO WEST AS DEEP MOISTURE MAKES ITS RETURN AFTER 6Z. GIVEN ALL OF THE CLOUD COVER...DO NOT EXPECT MUCH OF A DROP IN TEMPERATURES TONIGHT. HOWEVER...AS THE DEFORMATION PRECIP STARTS TO GET GOING TONIGHT...DYNAMIC COOLING OF THE ATMOSPHERE BENEATH THIS BAND SHOWS CRITICAL TEMPS/THICKNESSES BECOMING COLD ENOUGH FOR SNOW. LIKE THE IDEA OF THE SPC WRF FOR P-TYPE...WHICH MATCHES UP NICELY WITH THE NAM/ECMWF. THIS SCENARIO SHOWS PRECIP STARTING TO TURN OVER TO SNOW AFTER 9Z ACROSS CENTRAL MN. AS THE DEFORMATION BAND GETS SETUP ACROSS MN TUESDAY MORNING...EXPECT THIS MIX OR JUST SNOW TO BUILD SOUTH WITH THE LOW. WITHIN THE HEART OF THIS DEFORMATION BAND...DYNAMIC COOLING MAY VERY WELL KEEP THE ATMOSPHERE COLD ENOUGH TO KEEP THE P-TYPE AS ALL SNOW THROUGH THE DAY ON TUESDAY. AT THE MOMENT...THERE IS GOOD MODEL AGREEMENT ON THIS DEFORMATION BAND SETTING UP FROM AROUND THE CENTRAL MN/IA BORDER...UP THROUGH MANKATO AND THE TWIN CITIES UP TOWARD THE WESTERN TIP OF LAKE SUPERIOR. IT IS THIS REGION THAT COULD SEE MAINLY SNOW TOMORROW IF THE COOLING FROM DYNAMIC LIFT WITH THE DEFORMATION BAND IS STRONG ENOUGH. FOR NOW...BROUGHT TEMPS FOR TOMORROW AFTERNOON WHERE THIS BAND IS EXPECTED TO SETUP DOWN INTO THE MID 30S...COLD ENOUGH TO BRING A MENTION OF A NORTH-SOUTH ORIENTED BAND OF RA/SN MIX THROUGH THE DAY ACROSS THE CENTER OF THE MPX CWA. RIGHT NOW...HAVE A COUPLE INCHES OF ACCUMULATION UP AROUND KANABEC COUNTY...BUT COULD CERTAINLY SEE MORE DEPENDING ON HOW MUCH AND HOW LONG WE CAN THINGS COOL ENOUGH FOR SNOW. AT ANY RATE...WOULD NOT BE AT ALL SURPRISED IF FOR MUCH OF THE DAY...FOLKS IN THE TWIN CITIES ARE WATCHING THE FLAKES FLY AS OPPOSED TO RAIN FALL. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 410 PM CDT MON APR 28 2014 -HIGH CONFIDENCE IN PERIODS OF LIGHT RAIN /MIXED WITH WET SNOW AT TIMES/ ACROSS THE ENTIRE FORECAST AREA THROUGH THURSDAY. -HIGH CONFIDENCE IN BELOW NORMAL TEMPS THROUGH THE EXTENDED MN/WI WILL BE UNDER THE INFLUENCE OF A CLOSED UPPER LOW THROUGH THURSDAY. PERSISTENT CLOUD COVER...BREEZY WINDS...AND PERIODS OF LIGHT RAIN ARE EXPECTED UNTIL THE SYSTEM FINALLY LIFTS OFF TO THE NORTHEAST ON FRIDAY. THE TROUGH CURRENTLY OFF THE COAST OF NOVA SCOTIA WILL CONTINUE TO LIFT INTO THE NORTH ATLANTIC AND GET ABSORBED BY THE LONG WAVE TROUGH OVER NEWFOUNDLAND. THIS WILL ALLOW THE RIDGE OVER HUDSON BAY TO WEAKEN AND SLIDE EAST. THEREFORE...THE UPPER LOW CURRENTLY PARKED OVER NEBRASKA WILL HAVE ROOM TO LIFT NORTH AND ACTUALLY RETROGRADE BACK TO THE NORTHWEST ON WEDNESDAY. AS A RESULT...WE HAVE DECIDED TO FORECAST 70-90% RAIN FOR MOST OF THE FORECAST AREA THROUGH THURSDAY. THE RAIN MAY CLEAR FOR SEVERAL HOURS AT A TIME OR BECOME LESS WIDESPREAD IN COVERAGE DURING THIS STRETCH...BUT WE DON`T THINK MANY LOCATIONS WILL GO 6-12 HOURS WITHOUT SEEING AT LEAST LIGHT RAIN. THE GOOD NEWS FOR SWOLLEN DITCHES...RIVERS AND STREAMS WILL BE A TRANSITION TO LIGHT RAIN WITH TIME WITH LITTLE CHANCE FOR THUNDER. MANY LOCATIONS IN MN HAVE SEEN 0.30-0.75" EVERY 6 HOURS FOR THE PAST 36 HOURS. FOR WEDNESDAY AND THURSDAY...WE THINK QPF WILL BE MORE ON THE ORDER OF 0.05-0.15" ON A 6-HOURLY BASIS. EVEN BEYOND THE UPPER LOW EXITING THE FORECAST AREA...NORTHWEST FLOW AND EMBEDDED SHORTWAVES KEEP THE CHANCE FOR LIGHT RAIN /OR BRIEF PERIODS OF LIGHT SNOW IN THE MIX/ THROUGH THE WEEKEND. THE PRECIP CHANCES BEYOND THURSDAY ARE MORE UNCERTAIN...BUT ONE THING THAT ISN`T UNCERTAIN IS THE LIKELIHOOD OF COOLER THAN NORMAL TEMPS. NORMAL HIGHS ARE IN THE LOWER TO MID 60S OVER THE NEXT WEEK AND WE SHOULD REMAIN 10 TO 20 DEGREES BELOW THAT OVER THE NEXT 7 DAYS - CONFIRMED BY BOTH THE OPERATIONAL AND ENSEMBLE GUIDANCE FROM THE GFS AND ECMWF. .HYDRO...ENDURED THE HEAVIEST PCPN OF THE STORM LAST 48 HRS...AND NOW ONTO LIGHTER AMOUNTS THOUGH PRETTY CONSISTENT FOR THE NEXT FEW DAYS. SMALLER STREAMS/TRIBS WILL BEGIN TO SLOW THEIR RISES NEXT 24 HRS...REMAINING BELOW FS. WILL CONTINUE TO WATCH SAND CREEK/JORDAN THOUGH EXPECT IT TO QUICKLY BACK OFF NOW THAT MAIN PCPN BAND HAS MOVED NORTH. MAINSTEM RIVERS WILL CONTINUE SLOW RISE THROUGH THE WEEK...WITH BANKFUL BECOMING POSSIBLE ALONG MISSISSIPPI N AND S OF TWIN CITIES. HWVR...THREAT OF REACHING FS STILL MARGINAL AT BEST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1248 PM CDT MON APR 28 2014 THREE MAIN CONCERNS THIS TAF PERIOD ARE THE PRECIP BREAK COMING UP FROM THE SOUTH...HOW FAR WEST DO VFR CIGS OVER WI MAKE INTO MN...AND P-TYPE LATE TONIGHT/TUE MORNING. SEEING WARMING OF CLOUD TOPS COMING UP FROM THE SOUTH...AND GFS/NAM RH TIME CROSS SECTIONS SHOWS THIS IS ASSOCIATED WITH A MOMENTARY LOSS IN DEEP MOISTURE...WHICH SUPPORTS THE BRIEF DRYING NOTED IN THE HIGH RES MODELS. THEREFORE...FOLLOWED THE HRRR AND OTHER HIGH RES MODELS WITH BRINGING A BREAK IN THE FALLING PRECIP THIS EVENING...BEFORE EVERYTHING FILLS BACK IN TONIGHT. HOWEVER...NOT COMPLETELY SOLD ON THIS DRYING HAPPENING AS WE WILL STILL BE WITHIN A WAA PATTERN WITH DECENT MOISTURE TRANSPORT...SO THERE IS POTENTIAL FOR ANY BREAK TO FILL IN RATHER QUICKLY. ALSO SEE EAST WINDS TRYING TO BRING SOME HIGHER CIGS IN FROM CENTRAL WI...BUT RAIN MOISTENED AIR OVER MN SEEMS TO BE PUTTING ANY HALT TO THIS. THOUGH IF THE END IN PRECIP DOES MATERIALIZE...THEN WE COULD SEE THESE CIGS MAKE A RUN TO ABOUT MSP/STC BEFORE PRECIP RETURNS AS MID/UPPER LEVEL MOISTURE RETURNS. FOR P-TYPE...LIKE THE IDEA OF THE NAM AND OTHER HIRES MODELS WITH PRECIP TURNING OVER TO SNOW UP TOWARD DULUTH/PARK RAPIDS TONIGHT THAT WILL BUILD SOUTH INTO CENTRAL MN AFTER 9Z AS A STRONG DEFORMATION BAND OF PRECIP SETS UP. EXPECT THE HEART OF THIS PRECIP BAND TO SEE MAINLY SNOW DURING THE DAY ON TUESDAY. FOR NOW...BEST CHANCE OF SNOW /AND ACCUMULATING AT THAT/ IS AT STC DOWN TO THE WRN TWIN CITIES...BUT MSP CERTAINLY NOT OUT OF THE WOODS. ONCE THIS DEFORMATION BAND SETS UP BY TUESDAY MORNING...CONFIDENCE IS HIGH IN IFR CIGS/VIS DOMINATING ALL BUT MAYBE AXN/EAU FOR MOST OF TUESDAY. KMSP...CONFIDENCE IS MODERATE WITH MOMENTARY END TO PRECIP THIS EVENING...BUT LOWER WITH WHEN IN IT WILL RETURN TONIGHT...BUT FEEL ANY BREAK WILL BE DONE BY 6Z. AFTER THAT...THE QUESTION BECOMES DO WE SWITCH OVER TO A RASN MIX OR JUST PLAIN SNOW AT SOME POINT TUESDAY MORNING. DID INTRODUCE A MIX WITH THIS TAF. BASED ON THE NAM...12Z MAY BE A BIT EARLY...BUT IT IS NOT ENTIRELY OUT OF THE QUESTION THAT THE PREDOMINATE P-TYPE AT MSP FOR MUCH OF TOMORROW WILL BE ALL SNOW. NOT EXPECTING MUCH IN THE WAY OF ACCUMS ON PAVED SFCS...BUT IF WE DO GO MOSTLY SNOW...THAT WILL REALLY TANK THE VSBYS TOMORROW. IF YOU ARE LOOKING FOR SOME HIGH CONFIDENCE IN THIS TAF...LOOK NO FURTHER THAN THE WINDS. /OUTLOOK FOR KMSP/ WED...MVFR/IFR CONDS WITH PERIODS OF -SHRA. WINDS NW 10-15 KTS. THU...MVFR/IFR CONDS WITH PERIODS OF -SHRA. WINDS NW 10-15 KTS. FRI...MVFR CONDS...PRECIP DECREASING. WINDS NW 10-15 KTS. && .HYDROLOGY... ISSUED AT 410 PM CDT MON APR 28 2014 ENDURED THE HEAVIEST PCPN OF THE STORM LAST 48 HRS...AND NOW ONTO LIGHTER AMOUNTS THOUGH PRETTY CONSISTENT FOR THE NEXT FEW DAYS. SMALLER STREAMS/TRIBS WILL BEGIN TO SLOW THEIR RISES NEXT 24 HRS...REMAINING BELOW FS. WILL CONTINUE TO WATCH SAND CREEK/JORDAN THOUGH EXPECT IT TO QUICKLY BACK OFF NOW THAT MAIN PCPN BAND HAS MOVED NORTH. MAINSTEM RIVERS WILL CONTINUE SLOW RISE THROUGH THE WEEK...WITH BANKFUL BECOMING POSSIBLE ALONG MISSISSIPPI N AND S OF TWIN CITIES. HWVR...THREAT OF REACHING FS STILL MARGINAL AT BEST. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...CLF AVIATION...MPG HYDROLOGY...CCS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
134 PM CDT MON APR 28 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 415 AM CDT MON APR 28 2014 THE NEXT SPOKE OF 700-600MB FRONTOGENESIS/OMEGA WILL LIFT ACROSS THE AREA THIS MORNING...AND BRING THE NEXT BOUT OF RAIN SHOWERS. GROUND CONDITIONS ARE QUITE SATURATED...ESPECIALLY EAST OF AN ALEXANDRIA TO MANKATO LINE...TOWARD THE TWIN CITIES AND TURTLE LAKE WISCONSIN...WHERE RAINFALL AMOUNTS ON THE ORDER OF 1.5 TO 3 INCHES FELL OVER THE LAST 24 HOURS. UNFORTUNATELY...THIS AREA APPEARS TO GET NAILED WITH ANOTHER 1-3 INCHES TODAY. VIEW THE HYDROLOGY DISCUSSION BELOW FOR MORE INFORMATION ON HOW THIS WILL IMPACT THE RIVERS AND LOW LYING AREAS. BY LATE AFTERNOON...WE SHOULD START TO SEE SOME DRYING WORKING INTO SOUTHERN MN...BUT THAT WILL QUICKLY FILL BACK IN WITH PRECIPITATION THIS EVE AS THE LOW SHIFTS TO CENTRAL IA AND THE DEFORMATION PRECIP SETS UP OVER THE AREA. COLDER AIR WILL ALSO WORK INTO CENTRAL MN FROM THE NORTH...WHICH WILL MEAN THE POTENTIAL FOR SNOW TO ENTER THE MIX DURING THE NIGHTTIME HOURS. COULD SEE SOME MINOR ACCUMULATIONS ACROSS CENTRAL MN BETWEEN MIDNIGHT AND DAYBREAK TUESDAY. HIGHS TODAY WILL NOT GO VERY FAR...NOR WILL LOWS TONIGHT...AS ABUNDANT LOW CLOUDS AND PRECIP LINGER. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 415 AM CDT MON APR 28 2014 MODELS REMAIN LOCKED INTO THIS VERY UNUSUAL WEATHER PATTERN AS THE UPPER LOW CONTROLS THE UPPER MIDWEST THRU FRIDAY. SYNOPTICALLY...THE UPPER LOW AND ASSOCIATED SFC FEATURE WILL WEAKEN AND FILL ACROSS THE PLAINS...AND INTO THE UPPER MIDWEST AS THE MEAN UPPER FLOW IS CUTOFF THRU THU. MODELS ARE NEARLY IDENTICAL ON THE ORIENTATION OF THE UPPER LOW AS IT MOVES SLOWLY EASTWARD TOWARD IOWA BY TUESDAY MORNING...THEN PIVOTS AND ROTATES ACROSS THE WESTERN GREAT LAKES THRU THURSDAY NIGHT. AS PREVIOUS DISCUSSED WITH CUTOFF SYSTEMS...MODELS ARE USUALLY TOO FAST ON MOVING THEM OUT. IT USUALLY TAKES A KICKER OR SOME STRONGER WX FEATURE TO MOVE IT ALONG. ONLY THE GFS HOLDS ONTO THE UPPER LOW A BIT SLOWER THAN THE EC/GEM. ALTHOUGH THE KICKER WILL BE ANOTHER SHRTWV MOVING SE ACROSS THE PLAINS OF CANADA...IT REMAINS TOO FAST BASED ON THE ASSOCIATED BIASES OF THE MODELS. THEREFORE...THE CONTINUED TREND OF CLOUDS...SCATTERED PRECIPITATION AND COOL CONDS WILL REMAIN AT LEAST THRU THURSDAY. LATEST FORECAST HAS A DIMINISHING TREND ON POPS WITH ONLY CHC/SLIGHT CHC/S BY THU/FRI. THE DIMINISHING TREND IS BASED ON THE MAIN MOISTURE FEED CUTOFF FROM THE GULF AND ONLY RESIDUAL MOISTURE WILL BE PRESENT AFTER MONDAY NIGHT. ONE TREND THE MODELS HAVE INDICATED IN PREVIOUS RUNS IS THE THICKNESS VALUES DECREASING TO CRITICAL LEVELS BY LATE MONDAY/TUESDAY MORNING...AND ESPECIALLY WED. AS THE UPPER LOW BEGINS TO PIVOT TUE/WED...THE AIR MASS WHICH IS CURRENTLY OVER SE CANADA...WILL BE DRAWN WESTWARD OVER THE NORTHERN GREAT LAKES...AND ACROSS THE UPPER MIDWEST/NORTHERN PLAINS. AS THICKNESS VALUES FALL AND THE THERMAL COLUMN BLW 1KM HOLDS OR EVEN FALLS TO NEAR +1C...THE RAIN WILL BEGIN TO MIX WITH SNOW. EVEN THE WRF MODELS NMM/ARW HAVE THE PRECIPITATION TYPE MIXING OR CHANGING OVER TO SNOW TUE MORNING...AND AGAIN TUESDAY NIGHT AS SFC TEMPS FALL INTO THE MID 30S. IT IS NOT OUT OF THE QUESTION TO SEE SOME LIGHT ACCUMULATIONS IF ALL THE RIGHT INGREDIENTS OCCUR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1248 PM CDT MON APR 28 2014 THREE MAIN CONCERNS THIS TAF PERIOD ARE THE PRECIP BREAK COMING UP FROM THE SOUTH...HOW FAR WEST DO VFR CIGS OVER WI MAKE INTO MN...AND P-TYPE LATE TONIGHT/TUE MORNING. SEEING WARMING OF CLOUD TOPS COMING UP FROM THE SOUTH...AND GFS/NAM RH TIME CROSS SECTIONS SHOWS THIS IS ASSOCIATED WITH A MOMENTARY LOSS IN DEEP MOISTURE...WHICH SUPPORTS THE BRIEF DRYING NOTED IN THE HIGH RES MODELS. THEREFORE...FOLLOWED THE HRRR AND OTHER HIGH RES MODELS WITH BRINGING A BREAK IN THE FALLING PRECIP THIS EVENING...BEFORE EVERYTHING FILLS BACK IN TONIGHT. HOWEVER...NOT COMPLETELY SOLD ON THIS DRYING HAPPENING AS WE WILL STILL BE WITHIN A WAA PATTERN WITH DECENT MOISTURE TRANSPORT...SO THERE IS POTENTIAL FOR ANY BREAK TO FILL IN RATHER QUICKLY. ALSO SEE EAST WINDS TRYING TO BRING SOME HIGHER CIGS IN FROM CENTRAL WI...BUT RAIN MOISTENED AIR OVER MN SEEMS TO BE PUTTING ANY HALT TO THIS. THOUGH IF THE END IN PRECIP DOES MATERIALIZE...THEN WE COULD SEE THESE CIGS MAKE A RUN TO ABOUT MSP/STC BEFORE PRECIP RETURNS AS MID/UPPER LEVEL MOISTURE RETURNS. FOR P-TYPE...LIKE THE IDEA OF THE NAM AND OTHER HIRES MODELS WITH PRECIP TURNING OVER TO SNOW UP TOWARD DULUTH/PARK RAPIDS TONIGHT THAT WILL BUILD SOUTH INTO CENTRAL MN AFTER 9Z AS A STRONG DEFORMATION BAND OF PRECIP SETS UP. EXPECT THE HEART OF THIS PRECIP BAND TO SEE MAINLY SNOW DURING THE DAY ON TUESDAY. FOR NOW...BEST CHANCE OF SNOW /AND ACCUMULATING AT THAT/ IS AT STC DOWN TO THE WRN TWIN CITIES...BUT MSP CERTAINLY NOT OUT OF THE WOODS. ONCE THIS DEFORMATION BAND SETS UP BY TUESDAY MORNING...CONFIDENCE IS HIGH IN IFR CIGS/VIS DOMINATING ALL BUT MAYBE AXN/EAU FOR MOST OF TUESDAY. KMSP...CONFIDENCE IS MODERATE WITH MOMENTARY END TO PRECIP THIS EVENING...BUT LOWER WITH WHEN IN IT WILL RETURN TONIGHT...BUT FEEL ANY BREAK WILL BE DONE BY 6Z. AFTER THAT...THE QUESTION BECOMES DO WE SWITCH OVER TO A RASN MIX OR JUST PLAIN SNOW AT SOME POINT TUESDAY MORNING. DID INTRODUCE A MIX WITH THIS TAF. BASED ON THE NAM...12Z MAY BE A BIT EARLY...BUT IT IS NOT ENTIRELY OUT OF THE QUESTION THAT THE PREDOMINATE P-TYPE AT MSP FOR MUCH OF TOMORROW WILL BE ALL SNOW. NOT EXPECTING MUCH IN THE WAY OF ACCUMS ON PAVED SFCS...BUT IF WE DO GO MOSTLY SNOW...THAT WILL REALLY TANK THE VSBYS TOMORROW. IF YOU ARE LOOKING FOR SOME HIGH CONFIDENCE IN THIS TAF...LOOK NO FURTHER THAN THE WINDS. /OUTLOOK FOR KMSP/ WED...MVFR/IFR CONDS WITH PERIODS OF -SHRA. WINDS NW 10-15 KTS. THU...MVFR/IFR CONDS WITH PERIODS OF -SHRA. WINDS NW 10-15 KTS. FRI...MVFR CONDS...PRECIP DECREASING. WINDS NW 10-15 KTS. && .HYDROLOGY... ISSUED AT 415 AM CDT MON APR 28 2014 24 HOUR PRECIP AMOUNTS /ENDING AT 09Z MONDAY/ INDICATE A SOLID SWATH OF 1 TO 2.5 INCHES FELL ACROSS CENTRAL AND SOUTH CENTRAL MN AND INTO WEST CENTRAL WI...GENERALLY EAST OF AN ALEXANDRIA TO MANKATO LINE...ACROSS THE INTERSTATE 35 CORRIDOR AND INTO WEST CENTRAL WISCONSIN /AS FAR EAST AS TURTLE LAKE AND NEW RICHMOND/. THIS AREA WILL BE UNDER THE GUN AGAIN TODAY FOR ANOTHER DOUSING OF RAIN ON THE ORDER OF 1-2 INCHES. THE IMMEDIATE CONCERN WILL BE FOR MINOR AREAL FLOODING IN LOW LYING AREAS AND POOR DRAINAGE LOCALES. WHILE THE BRIEF RESPITE FROM RAIN OVERNIGHT SHOULD HELP A BIT...THERE WILL LIKELY BE SPOTS THAT HAVE PONDING ISSUES FURTHER EXACERBATED BY TODAY/S BOUT OF RAIN. THE SECOND CONCERN HYDROLOGICALLY SPEAKING IS WITH REGARD TO THE POTENTIAL FOR RIVER FLOODING. RISES ON LOCAL STREAMS HAVE YIELDED SMALL RISES ON THE ST CROIX...MISSISSIPPI... MINNESOTA...CHIPPEWA...AND CROW RIVERS AMONG OTHERS. WILL LIKELY SEE SEVERAL SITES ALONG THESE RIVERS CREEP TOWARD THEIR ACTION STAGES WITH THE ADDITIONAL 1 TO 2 INCHES EXPECTED TODAY. THE SITE OF GREATEST CONCERN AT THE CURRENT TIME IS THE MISSISSIPPI AT HASTINGS...WHICH COULD RISE ABOVE FLOOD STAGE IF THE PRECIPITATION FORECAST WORKS OUT AS ANTICIPATED. THANKFULLY...THE RESPONSE TIME IS NOT QUICK...SO THERE IS TIME FOR FORECAST REFINEMENT GIVEN CURRENT INDICATIONS ARE THAT IT WOULD NOT RISE ABOVE FS UNTIL THE 3RD OF MAY. FOR THE WI SITES...THE CHIPPEWA AT DURAND BEARS WATCHING...BUT HAS MORE WIGGLE ROOM GIVEN PRECIP 24 PRECIP AMOUNTS FEEDING INTO THE RIVER WERE SLIGHTLY LOWER. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...LS LONG TERM...JLT AVIATION...MPG HYDROLOGY...LS
AREA FORECAST DISCUSSION
NWS JACKSON MS
1141 AM CDT MON APR 28 2014 .UPDATE......SEVERE WEATHER OUTBREAK EXPECTED THIS AFTERNOON AND EVENING... ...SIGNIFICANT FLOODING POSSIBLE MONDAY INTO EARLY TUESDAY... .UPDATE...NOT MANY UPDATES MADE TO GOING FORECAST AS SEVERE WEATHER OUTBREAK REMAINS ON TRACK FOR LATE THIS MORNING AND ESPECIALLY INTO THIS AFTERNOON AND EVENING WHERE STRONG AND POSSIBLY LONG TRACK TORNADOES COULD OCCUR. CAUTION IS HIGHLY ADVISED FOR THIS POTENTIALLY LIFE THREATENING AND DANGEROUS SITUATION. .DISCUSSION...INITIAL LEAD S/WV RESPONSIBLE FOR THIS MORNINGS ACTIVELY IS LIFTING NE AWAY FROM THE REGION RESULTING IN A WEAKENING TREND OF THAT ACTIVITY. HOWEVER, A CYCLONICALLY CURVED H5-H3 JET STREAK IS OBSERVED ON WV CHANNELS...REGIONAL VAD WIND PROFILES AND IN NWP SURGING INTO THE NW DELTA AND THE ARKLAMISS AT THIS HOUR. THIS SIGNATURE COUPLED WITH NEAR 2000 J/KG SBCAPE IS ALREADY INITIALIZING ACROSS THE DELTA REGION WITH THE THIS NEXT AND MORE POTENT ROUND OF SEVERE WEATHER EXPECTED FOR THE REGION. 0-1 KM ESRH REMAINS NEAR 200M2/S2 PER MESOANALYSIS AS OF 16Z BUT NWP SUITE SUGGESTS STEADILY INCREASING LOW LVL SHEAR VALUES TOWARDS 300M2/S2 AND POSSIBLY HIGHER THROUGH THE EARLY AFTN AND EVENING WHERE WORRISOME 0-1 KM EHI AND STRONG TORNADO PARAMETERS VALUES INDICATE HEALTHY ENVIRONMENT CAPABLE OF SUPPORTING SOME STRONG AND POSSIBLY LONG TRACK TORNADOES. SPC SSEO UPDRAFT HELICITY SIGNALS SUGGEST THAT GREATEST RISK FOR THESE TORNADOES COULD BE ACROSS NORTH CENTRAL AND NORTHEAST MISSISSIPPI EXTENDING ALONG THE NATCHEZ TRACE CORRIDOR TOWARDS THE JACKSON METROPLEX MID TO LATE AFTERNOON INTO THE EVENING. A COUPLE OF ROUGE STORMS COULD ALSO DEVELOP SOUTH OF I-20 AND WITH LESS COMPETITION FOR RESOURCES AND POTENTIALLY NON-BLOCKED INFLOW COULD BE TROUBLESOME. THE TRENDS OF LOCAL WRF AND THE HRRR ECHO SPC SSEO HELICITY SIGNALS THAT WHAT SEMI-DISCRETE STORMS DEVELOP WILL BE CAPABLE OF STRONG ROTATING UPDRAFTS. NAM BUFR SOUNDINGS FOR JACKSON FOR MID AFTN SUGGEST 0-3 SRH VALUES NEAR 500 M2/S2 WITH THIS ENVIRONMENT LIKELY IN PLACE ALONG THE TRACE CORRIDOR. GRAPHICS HAVE BEEN UPDATED TO REFLECT THIS HIGHER RISK AREA. UPDATES ARE OUT AND AN UPDATED AVIATION DISCUSSION CAN BE FOUND DIRECTLY BELOW. /ALLEN/ && .AVIATION...MVFR CIGS WERE STILL BEING REPORTED AT 15Z IN THE SOUTH BUT CIGS SHOULD RISE ABOVE 3KFT BY 17Z AREAWIDE. BREEZY SOUTH WINDS OF 15-20KTS WITH GUSTS 30KTS AWAY FROM STORMS TODAY. CONDITIONS COULD DETERIORATE THIS AFTN INTO THE EVENING AS WIDESPREAD TSTMS...SOME SEVERE WL BE PSBL. AWAY FROM STORMS...MVFR CIGS WL REDEVELOP TONIGHT AREAWIDE. STRONGER SW WINDS AND ANOTHER ROUND OF POTENTIALLY SEVERE TSTMS ARE EXPECTED TUESDAY...ESPECIALLY OVER THE SE HALF OF THE AREA. /22/ && .PREV DISCUSSION... /ISSUED 350 AM CDT MON APR 28 2014/ SHORT TERM...TODAY THROUGH TUESDAY NIGHT SEVERAL ROUNDS OF SIGNIFICANT SEVERE WEATHER HAZARDS ARE EXPECTED TO IMPACT THE REGION TODAY THROUGH TUESDAY ALONG WITH SOME POSSIBLE SIGNIFICANT FLOODING FROM HEAVY RAINFALL. TODAY STILL LOOKS TO BE PARTICULARLY VOLATILE...ESPECIALLY WITH THE STRONG SHEAR IN PLACE. THE LATEST SATELLITE IMAGERY SHOWED A STRONG CLOSED STORM CIRCULATION OVER THE CENTRAL PLAINS AROUND NEBRASKA WITH SEVERE CONVECTION PUSHING ACROSS THE ARKLATEX. A SERIES OF VORT LOBES WERE ROTATING AROUND THE CLOSED STORM SYSTEM WHICH WAS BRINGING ASCENT FOR CONVECTIVE FORMATION. A STRONG JET STREAM WAS PIVOTING AROUND THE SOUTHERN AXIS OF THE CLOSED SYSTEM. THERE WAS AN ASSOCIATED 985 MB SURFACE LOW WITH AS ASSOCIATED COLD FRONT AND DRY LINE EXTENDING DOWN INTO TEXAS. WE WERE IN THE WARM SECTOR WITH DEWPOINTS IN THE MID 60S TO AROUND 70. THE ATMOSPHERE HAD GOOD JET DYNAMICS ...STRONG VERTICAL SHEAR(EFFECTIVE BULK SHEAR 40-60 KNOTS AND INSTABILITY IN PLACE FOR MULTIPLE ROUNDS OF A SEVERE WEATHER OUTBREAK FOR FOR TODAY THROUGH TUESDAY. FOR TODAY A STRONG SHORTWAVE WILL ROTATE AROUND THE CLOSED SYSTEM WHILE THE STORM SYSTEM WILL CONTINUE TO DEEPEN. HEIGHT FALLS... STRONG LAPSE RATES...STRONG DYNAMIC SHEAR AND INSTABILITY WILL PUSH INTO THE REGION. THIS COULD HELP SEVERE CONVECTION TO DEVELOP ACROSS THE WEST EARLY AND SPREAD ACROSS THE REGION DURING THE DAY. THE BROKEN LINE OF DISCRETE SUPERCELL STORMS TO THE WEST WILL PUSH ACROSS THE REGION TODAY. THE MODEL SOUNDINGS CONTINUE TO SHOW IMPRESSIVE SIGNATURES FOR ALL MODES OF SEVERE WEATHER FOR TODAY THROUGH TUESDAY INCLUDING THE RISK OF SOME STRONG TORNADOES. THE FIRST ROUND WILL AFFECT THE WESTERN AREAS THIS MORNING AND MARCH ACROSS THE REGION DURING THE DAY. THE SURFACE BOUNDARY/DRYLINE WILL BE SLOWLY APPROACHING FROM THE WEST. LATEST SPC WRF SHOWS SOME STRONG MAXIMUM UPDRAFT HELICITY VALUES WITH THESE STORMS. AS WE GO INTO TONIGHT EXPECT SOME MORE DEVELOPMENT FROM THE WEST. ALOT WILL DEPEND HOW THE CONVECTIVE FEATURES WILL DEVELOP DURING THE PERIOD FOR BRIEF PERIODS OF LULLS BETWEEN ROUNDS OF SEVERE WEATHER. SPC HAS PUT MOST OF THE REGION UNDER A MODERATE RISK FOR DAY ONE. ALSO THE LOCAL WRF SHOWS IMPRESSIVE UPDRAFT HELICITY IN THE NORTHEAST FOR LATE THIS AFTERNOON WITH THESE STORMS FROM DISCRETE SUPERCELLS. HEAVY RAIN WILL ALSO BE A CONCERN FOR TODAY THROUGH EARLY TUESDAY WITH STRONG UPPER DIVERGENCE. MODELS SOUNDINGS AND CROSS SECTIONS SHOWS STRONG ASCENT FOR THE INFLOW OF GULF MOISTURE WITH PWATS AROUND 1.8 INCHES. THE DAY ONE GRAPHIC FOR EXCESSIVE RAIN SHOWS A MODERATE RISK ACROSS MOST OF THE AREA. SOME OF THE WRF MODELS SHOWS SOME POSSIBLE TRAINING ACROSS SOME OF OUR RIVER BASINS. CORFIDI VECTORS SHOWS SOME RIDGING MOVING ACROSS THE REGION FOR SOME TRAINING OF CELLS FOR HEAVY RAINFALL AND SOME POSSIBLE BACKBUILDING. WPC SHOWS 2 TO 4 INCH RAINFALL AMOUNTS ACROSS THE REGION. SO WITH THAT IN MIND HAVE EXPANDED THE TIME OF THE CURRENT WATCH AS WELL AS ADDED THE SOUTHEAST PORTION OF THE REGION AT 22Z UNTIL 12Z TUESDAY. FOR TUESDAY AND TUESDAY NIGHT...ANOTHER STRONG SHORTWAVE WILL ROTATE AROUND THE CLOSED SYSTEM OVER NORTHERN MISSOURI. MODELS SHOWS THAT THE LOW LEVEL INFLOW WILL WEAKEN SOME IN THE LOW LEVELS OF 850 MBS AND BELOW. THIS WILL WEAKEN THE BULK SHEAR SOME IN THE 1 AND 2 KM LAYER. HOWEVER THE DEEP LAYER SHEAR 0-6 KM WILL MAKE UP FOR IT WITH READINGS FROM 60 TO NEAR 100 KNOTS. THIS COMBINED WITH STRONG INSTABILITY WILL KEEP ALL MODES OF SEVERE WEATHER ON TRACK. THE SURFACE BOUNDARY WILL MOVE THROUGH THE REGION TUESDAY AFTERNOON AND EVENING. EXPECT THE BULK OF THE SEVERE WEATHER TO AFFECT MAINLY THE EAST HALF OF THE REGION AND EXIT OUT OF THE ARKLAMISS BY EARLY TUESDAY EVENING. AS FAR AS TEMPS ARE CONCERN WENT CLOSE TO GMOS TEMPS FOR DAILY HIGHS AND CLOSE TO CURRENT FORECAST FOR NIGHTLY LOWS. MOS GUIDANCE LOOKED A LITTLE COOL FOR THE NIGHTLY LOWS./17/ LONGTERM...WEDNESDAY THROUGH SUNDAY...DESPITE CONTINUED MID/UPPER LEVEL SW FLOW STILL STREAMING MOISTURE OVER THE REGION WED/THU...LOW LEVEL NORTHERLY FLOW BEHIND SURFACE BOUNDARY...BY NOW OVER AL...WILL HAVE SCOURED OUT MAJORITY OF APPRECIABLE MOISTURE. WHILE BOTH THE GFS AND ECMWF SHOW THIS SCENARIO...GFS MOS WANTS TO PAINT SLIGHT POPS FOR MUCH OF THE PERIOD WITH NO QPF AT ALL. DO AGREE THAT THERE WILL BE SOME SLIGHT CHANCE FOR PASSING MID LEVEL WAVE ON FRIDAY...BUT NOT ALL DURING THE WEEK LEADING UP TO THEN. HAVE CUT POPS FOR WED/THU AND AGAIN SAT/SUN AS PATTERN JUST DOES NOT LOOK CONDUCIVE FOR APPRECIABLE...IF ANY...PRECIPITATION. ECMWF SHOWING SOME CAPES AROUND 500 J/KG AVAILABLE FOR FRIDAY AFTERNOON...WILL ADD SOME POSSIBILITY FOR THUNDER TO THE EXPECTED SHOWERS. TEMPS DURING THIS TIMEFRAME WILL BE UNSEASONABLY COOL AND SOME 10 TO 15 DEGREES BELOW NORMAL. DESPITE THE COOL NIGHTTIME LOWS IN THE 40S...TEMPS STILL WILL BE JUST A LITTLE BIT TOO WARM FOR FROST CONCERNS./26/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 85 68 83 55 / 76 90 59 29 MERIDIAN 85 66 84 55 / 56 100 73 51 VICKSBURG 85 66 82 54 / 84 82 44 22 HATTIESBURG 86 69 85 60 / 40 100 55 31 NATCHEZ 84 69 83 54 / 72 81 36 15 GREENVILLE 83 63 79 52 / 87 79 49 23 GREENWOOD 82 65 81 53 / 86 99 61 28 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR MSZ018-019-025>052. FLASH FLOOD WATCH FROM 5 PM CDT THIS AFTERNOON THROUGH TUESDAY MORNING FOR MSZ055>058-063>066-072>074. LA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR LAZ007>009-015-016. AR...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR ARZ074-075. && $$ ALLEN/22/17/26
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1136 AM CDT Mon Apr 28 2014 .UPDATE: Issued at 1135 AM CDT Mon Apr 28 2014 Large cumulus field has recently developed across central Missouri in convergence zone just ahead of surface cold front/dryline. Environment is becoming increasing unstable with latest 16Z SPC MLCAPES showing 500-1000 J/kg over central and eastern Missouri with little CINH right ahead of the front. Current thinking is that thunderstorms will develop in the next hour or two right ahead of the the front and move east and northeast across eastern Missouri into Illinois during the afternoon hours. Severe threat including hail and damaging winds continues given the increasing instability and impressive deep layer shear. Also, 0-1km SRH values are currently between 100 and 250 across eastern Missouri and Illinois support an isolated tornado risk. Britt && .SHORT TERM: (Through Late This Afternoon) Issued at 152 AM CDT Mon Apr 28 2014 Latest HRRR weakens most of the convection currently across our forecast area, or shifts it southeast of the region by 12z Monday. There may be a brief lull in the convection early this morning, then new convection should break out late this morning and early this afternoon from Edina to Quincy and south through the St Louis metro area to the FAM area, then shift eastward through our IL counties later this afternoon. This will occur as a shortwave ejects out of the southern Plains into southeast MO and a cold front/dry line surges eastward into eastern MO by 00z Tue. Should have CAPEs up to 2000-2500 J/Kg ahead of the cold front around 18z Monday with surface LI values down to around -10. Strongest low-mid level wind shear should be across southeast MO and southwest IL with strong 500 mb wind max moving through AR into portions of southeast MO, southern IL, and western portions of TN and KY. The severe weather threat should be over the eastern portion of our area, in portions of west central and southwest IL with the primary threat being large hail and damaging winds. This will occur from the late morning, through the afternoon and into the early evening hours. GKS .LONG TERM: (Tonight through Sunday) Issued at 341 AM CDT Mon Apr 28 2014 The showers and thunderstorms should be confined to areas east of the Mississippi River this evening and should be weakening by late evening as the higher surface dewpoints and instability shifts east of our forecast area. Little if any precipitation should be left late tonight. Temperatures will be cooler tonight due to low level cold air advection in our area south of the upper level and associated surface low. More showers and a few thunderstorms on Tuesday as the moisture wraps around the slow moving upper/surface low north of our area. The best chance for rain will be across the northwest half of our forecast area. The models keep the showers going Tuesday night as shortwaves rotate around the mid-upper level low. The gradual cooling trend will continue with well below normal temperatures for Wednesday and Wednesday night. The GFS and ECMWF models drop the zero degree C 850 mb isotherm southeastward into our forecast area Tuesday night or Wednesday, the cooler NAM even earlier. Although there will likely be rain across our area again on Wednesday it should be on the light side. The rain should be mainly diurnal on Thursday and Friday and favor the northern portion of our forecast area as the upper level low weakens and moves into the Great Lakes region. Will see warmer high temperatures for the weekend as the upper level heights begin to rise and southerly surface/low level flow returns Saturday night. Low-mid level warm air advection ahead of a weak shortwave and associated surface low may bring showers to the extreme northern portion of our forecast area late Saturday night and Sunday. GKS && .AVIATION: (For the 12z TAFs through 12z Tuesday Morning) Issued at 633 AM CDT Mon Apr 28 2014 VFR conditions outside of TSRA will prevail at the TAF sites thru the valid period. Another round of TSRA is expected to develop mainly east of the MS river around midday, leaving UIN and the STL Metro sites on the backedge of what does form. Due to these TAF sites being on the backedge, have elected to keep VCTS mention versus TEMPO until we get closer to initiation time. What does develop should shove off to the northeast by late afternoon. Gusty southerly winds are expected, diminishing tonight. Specifics for KSTL: VFR outside of TSRA thru the valid period. Another round of TSRA is expected to develop over the STL Metro area around midday with what does form shoving off to the northeast by mid-afternoon. Due to the terminal anticipated to being on the backedge, have elected to keep VCTS mention versus TEMPO until we get closer to initiation time. Gusty southerly winds are expected, diminishing tonight. TES && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
641 PM EDT MON APR 28 2014 .SYNOPSIS... UNSETTLED WEATHER WILL PERSIST OVER THE NEXT COUPLE OF DAYS. SHOWERS AND THUNDERSTORMS ARE EXPECTED INCREASE IN COVERAGE THROUGH WEDNESDAY AS A TROUGH OF LOW PRESSURE APPROACHES FROM THE WEST. ANOTHER QUICK ROUND OF RAIN IS POSSIBLE LATE FRIDAY AND SATURDAY BEFORE CONDITIONS DRY OUT INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 645 PM MONDAY...A CLUSTER OF STRONG TO SEVERE THUNDERSTORMS DEVELOPED ALONG A STATIONARY FRONT ACROSS SOUTHERN NORTH CAROLINA A FEW HOURS AGO. SUBJECTIVE SURFACE ANALYSIS SHOWED SIGNIFICANT BACKING OF THE LOW-LEVEL WIND ACROSS THE COASTAL PLAIN OF NC WHILE MODIFIED 18Z MODEL SOUNDINGS INDICATED CAPE AS HIGH AS 2700 J/KG EARLIER. MULTICELL STORMS DEVELOPED BUT DID NOT DISPLAY SIGNIFICANT DEVIANT MOTION AS THEY MIGHT HAVE HAD SUPERCELLS DEVELOPED. STILL... HIGH REFLECTIVITY CORES REACHED INTO COLD ENOUGH LAYERS OF THE ATMOSPHERE TO LEAD US TO BELIEVE LARGE HAIL WAS A SIGNIFICANT THREAT. IF YOU OBSERVED HAIL OR WIND DAMAGE ACROSS ROBESON OR BLADEN COUNTIES THIS EVENING PLEASE LET US KNOW! THE FRONT SHOULD REMAIN NEARLY STATIONARY ACROSS SOUTHERN NORTH CAROLINA THIS EVENING...MAINLY JUST NORTH OF LUMBERTON AND ELIZABETHTOWN ARCING NORTHEASTWARD TOWARD NEW BERN ALONG THE COAST. THIS WILL LEAVE OUR FORECAST AREA IN A WARM AND HUMID TROPICAL AIRMASS WITH DEWPOINTS AND LOW TEMPERATURES FORECAST TO BE IN THE UPPER 60S. THE 500 MB RIDGE AXIS THAT HAS HELPED TO SUPPRESS PRECIPITATION OVER THE PAST FEW HOURS WILL FINALLY PUSH OFFSHORE LATE TONIGHT...AND THERE IS THE POTENTIAL FOR A REDEVELOPMENT OF AT LEAST ISOLATED SHOWERS/T-STORMS JUST BEFORE DAYBREAK AS WIND VECTORS BECOME DIFLUENT ALOFT AND THE 850 MB WIND BACKS AND STRENGTHENS. PREVIOUS DISCUSSION FROM 230 PM FOLLOWS... INCREASINGLY WARM AND MORE UNSTABLE AIR MASS WITH TEMPS INTO THE 80S MOST PLACES. MODELS STILL SHOW MID TO UPPER RIDGE LINED UP THE SOUTHEAST COAST WHICH SHOULD HELP TO INHIBIT SOME OF THE STRONGEST CONVECTION RUNNING SOUTH...BUT AS TEMPS WARMED INTO THE 80S AND DEWPOINTS INTO THE MID 60S CLOSER TO 70 OVER SOUTH CAROLINA. HRRR AND RUC SHOWING BEST CAPE LINED UP INLAND FROM SOUTH TO NORTH TOWARD DARLINGTON AND MARLBORO...BUT MAIN FOCUS OF STRONGER CONVECTION WILL BE ALONG THE LINGERING FRONTAL BOUNDARY JUST TO THE NORTH OF LOCAL FORECAST AREA. EXPECT SCT CONVECTION OVER THE AREA WITH MAIN FOCUS ALONG SEA BREEZE CONVERGENT BOUNDARY AND RUNNING ALONG LINGERING FRONTAL BOUNDARY. JUST NORTH OF BOUNDARY STILL SEEING TEMPS NOT EVEN REACHING 70 WITH COOLER AIR WEDGED IN. BEST HELICITY WILL RUN ALONG WARM FRONT WITH VALUES ABOVE 200 JUST TO NORTH. OVERALL SHOULD BE RATHER FINE BOUNDARY OF STRONGEST STORMS AS FORCING REMAINS WEAKER FARTHER SOUTH DUE TO INCREASED SUBSIDENCE WITH MID TO UPPER RIDGE OVER THE SOUTHEAST COAST. OVERALL THREAT OF HAIL AND STRONG WINDS WITH ANY STORMS THAT MAY REACH INTO OUR NORTHERN TIER COUNTIES. THE STEERING FLOW WILL PUSH ANY SHWRS/TSTMS THAT DEVELOP TOWARD THE COAST BUT THE MORE STABILIZED AIR BEHIND SEA BREEZE SHOULD KEEP THE IMMEDIATE COAST FREE OF STORMS. KEPT POPS VERY CLOSE TO PREVIOUS FORECAST WITH ONLY MINOR ADJUSTMENTS AND WILL UPDATE AS NEEDED ONCE CONVECTION FLARES. SHOULD SEE A FAIR AMOUNT OF CLOUDS AS CONVECTIVE DEBRIS CLOUDS WILL BE STEERED EAST MIXED WITH CU FIELD ACROSS THE AREA. THE STALLED BOUNDARY WILL BEGIN TO LIFT NORTH THROUGH TONIGHT AND EXPECT LOCALIZED CONVECTION TO SHUT DOWN AS HEATING OF THE DAY CUTS OFF AFTER SUNSET. THEREFORE WILL TAPER OFF POPS AFTER SUNSET LEAVING BEST CHC TO THE NORTH ALONG BOUNDARY. SHOULD BE A RELATIVELY QUIET NIGHT WITH LOWS WELL ABOVE CLIMO...RUNNING IN THE MID 60S IN A WARM AND HUMID AIRMASS. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 330 PM MONDAY...ATTENTION THROUGHOUT THE ENTIRE FORECAST PERIOD WILL FOCUS ON UNSETTLED WEATHER...INCLUDING THE THREAT FOR SEVERE WEATHER JUST AHEAD OF AN APPROACHING COLD FRONT. LATEST GUIDANCE CONTINUES TO ILLUSTRATE A LONGWAVE TROUGH ACROSS THE CONUS WITH A PERSISTENT UPPER LEVEL LOW WHICH WILL SLOWLY PROGRESS ACROSS THE MIDWEST OVER THE NEXT COUPLE OF DAYS. WARM TEMPERATURES AND SOUTHWEST FLOW WILL ALLOW FOR A MOISTURE-RICH ATMOSPHERE...AS DEWPOINTS ARE WELL IN THE 60S...TO REMAIN IN PLACE WITH HIGHS ON TUESDAY IN THE LOWER 80S ACROSS THE ENTIRE FORECAST AREA. SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGHOUT THE DAY ON TUESDAY WHICH IS IN GOOD AGREEMENT AS OUR AREA IS INCLUDED IN SPC`S SLIGHT RISK. INTO WEDNESDAY...CONDITIONS WILL CONTINUE TO PROGRESS IN INCREASE...AS IT LOOKS THE BETTER INSTABILITY AND LIFT WILL MOVE INTO THE CENTRAL SC/NC/VA AREA...WITH A HEIGHTENED POSSIBILITY OF SEVERE ESPECIALLY IN OUR WESTERN ZONES. DIFFICULTY WILL BE TIMING AS MODELS HAVE EVER SO SLIGHTLY SLOWED DOWN THE PROGRESSION OF THE SYSTEM IN PAST RUNS. HOWEVER...OVERALL ANTICIPATE MAIN THREAT TO OCCUR WEDNESDAY THROUGHOUT THE DAY WITH AMPLE DIURNAL HEATING WITH HIGHS ON WEDNESDAY AGAIN IN THE 80S...INTO EARLY THURSDAY MORNING. WILL ALSO TAKE INTO ACCOUNT THE INTERACTION OF THE SEA BREEZE AS WELL ON BOTH DAYS AND ANY OTHER WANDERING BOUNDARIES ABOUT THE AREA. THE PRIMARY THREATS WILL BE HAIL AND DAMAGING WINDS...ALONG WITH THE POSSIBILITY OF TORNADOES. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 300 PM MONDAY...THURSDAY MAY BE RATHER ACTIVE. THE UPPER RIDGE AXIS WILL BE OFFSHORE ALLOWING FOR DEEP SWRLY FLOW. SURFACE BOUNDARY AND UPPER LEVEL VORT MAXES MAY SPONSOR DEEP ENOUGH LIFT FOR FAIRLY WIDESPREAD CONVECTION. WIND FIELDS MAY BE STRONG ENOUGH FOR STORM ORGANIZATION WITH DAMAGING WIND AND/OR HAIL. MORE QUESTIONABLE WHETHER OR NOT INSTABILITY MANAGES TO DEVELOP HOWEVER. BOUNDARY PUSHES OFFSHORE THURSDAY NIGHT WHICH MAY ALLOW FOR A COOLER AND DRIER FRIDAY. TRAILING UPPER ENERGY ON SATURDAY BUT TOUGH CALL AS TO WHETHER OR NOT ENOUGH MOISTURE AROUND FOR MEANINGFUL RAIN CHANCES. DRY WNW FLOW FOR SUNDAY AND MONDAY. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 18Z..STILL LOOKING FOR CONVECTION TO FIRE ALONG A DIFFUSE WARM FRONT THIS AFTERNOON. MOST OF THE ACTIVITY WILL BE OVER THE NORTHERN THIRD OF THE CWA...BUT COULD NOT RULE OUT WEAK CONVECTION TO THE SOUTH ALONG THE SEA BREEZE BOUNDARY. BRIEF IFR PERIODS ARE POSSIBLE...MAINLY AT LBT AND ILM. MOST OF THE ACTIVITY WILL END THIS EVENING AS THE WARM FRONT WAVES NORTH. WITH THE SOUTHWESTERLY FLOW TONIGHT...IFR STRATUS IS A REASONABLE BET. TUESDAY...BECOMING VFR WITH ANOTHER ROUND OF CONVECTION POSSIBLE BY THE END OF THE FORECAST PERIOD. EXTENDED OUTLOOK...SCATTERED AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS POSSIBLE THROUGH THURSDAY. OTHERWISE EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 645 PM MONDAY...BASED ON OBSERVATIONS AND THE 18Z MODELS I HAVE INCREASED WIND SPEEDS THROUGH THE NIGHT BY A FEW KNOTS...WITH 10-15 KNOTS EXPECTED FOR MOST AREAS THROUGH THE NIGHT. THAT SHOULD SUPPORT 2 FOOT SEAS BUILDING THROUGH 3 FEET OVERNIGHT. A CLUSTER OF STRONG TO SEVERE THUNDERSTORMS ACROSS SOUTHEASTERN NC SHOULD LARGELY MISS THE COASTAL WATERS...BUT THERE IS A POTENTIAL FOR ISOLATED SHOWERS OR T-STORMS THIS EVENING...THEN PERHAPS REDEVELOPING VERY LATE TONIGHT. PREVIOUS DISCUSSION FROM 230 PM FOLLOWS... QUIET MARINE CONDITIONS OVERALL THROUGH THIS AFTERNOON. HIGH PRESSURE REMAINS OVER THE AREA WITH LINGERING BOUNDARY LIFTING NORTH OF THE THE WATERS. GRADIENT REMAINS LIGHT WITH SOUTH TO SOUTHEAST FLOW REMAINING UNDER 10 KT THROUGH THE MORNING HOURS WITH SEAS 2 FT OR LESS. MAY SEE A FEW LINGERING SHOWERS MAKE IT OVER THE WATERS JUST ALONG NORTHERN PORTION OF LOCAL WATERS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 330 PM MONDAY...EXPECT SOUTH- SOUTHWEST FLOW TO PERSIST THROUGH THE FORECAST PERIOD WITH INCREASING WINDS WEDNESDAY INTO WEDNESDAY EVENING WHERE WINDS WILL INCREASE TO AROUND 20 TO 25 KTS...WHILE THE REMAINDER OF THE PERIOD ANTICIPATE 15 TO 20 KTS WITH ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE. AS FOR SEAS...2 TO 4 FT WITH 5 FT POSSIBLE. COULD SEE 6 TO 7 FT POSSIBLE IN THE OUTER WATERS WEDNESDAY INTO THURSDAY MORNING. ANTICIPATE CONDITIONS WILL WARRANT A SMALL CRAFT ADVISORY WEDNESDAY EVENING. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 300 PM MONDAY...PREFRONTAL FLOW REGIME ON THURSDAY PROBABLY STRONG ENOUGH TO WARRANT A SMALL CRAFT ADVISORY. A WINDSHIFT TO A MORE OFFSHORE DIRECTION THURSDAY NIGHT INTO FRIDAY PAIRED WITH A DOWNWARD TREND IN THE WIND SPEED WILL ALLOW ADVISORY TO BE DROPPED. OFFSHORE WINDS AND FAIRLY SEASONABLE SEAS CONTINUES INTO SATURDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...COASTAL FLOOD ADVISORY FOR INLAND NEW HANOVER COUNTY FROM 9 PM UNTIL MIDNIGHT. MARINE...NONE. && $$ SYNOPSIS...SGL NEAR TERM...RGZ/TRA SHORT TERM...SGL LONG TERM...MBB AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
348 PM EDT MON APR 28 2014 .SYNOPSIS... UNSETTLED WEATHER WILL PERSIST OVER THE NEXT COUPLE OF DAYS AS SHOWERS AND THUNDERSTORMS ARE EXPECTED INCREASE IN COVERAGE TODAY THROUGH WEDNESDAY AS A TROUGH OF LOW PRESSURE APPROACHES FROM THE WEST. ANOTHER QUICK ROUND OF RAIN IS POSSIBLE LATE FRIDAY AND SATURDAY BEFORE CONDITIONS DRY OUT INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 230 PM MONDAY...INCREASINGLY WARM AND MORE UNSTABLE AIR MASS WITH TEMPS INTO THE 80S MOST PLACES. MODELS STILL SHOW MID TO UPPER RIDGE LINED UP THE SOUTHEAST COAST WHICH SHOULD HELP TO INHIBIT SOME OF THE STRONGEST CONVECTION RUNNING SOUTH...BUT AS TEMPS WARMED INTO THE 80S AND DEWPOINTS INTO THE MID 60S CLOSER TO 70 OVER SOUTH CAROLINA. HRRR AND RUC SHOWING BEST CAPE LINED UP INLAND FROM SOUTH TO NORTH TOWARD DARLINGTON AND MARLBORO...BUT MAIN FOCUS OF STRONGER CONVECTION WILL BE ALONG THE LINGERING FRONTAL BOUNDARY JUST TO THE NORTH OF LOCAL FORECAST AREA. EXPECT SCT CONVECTION OVER THE AREA WITH MAIN FOCUS ALONG SEA BREEZE CONVERGENT BOUNDARY AND RUNNING ALONG LINGERING FRONTAL BOUNDARY. JUST NORTH OF BOUNDARY STILL SEEING TEMPS NOT EVEN REACHING 70 WITH COOLER AIR WEDGED IN. BEST HELICITY WILL RUN ALONG WARM FRONT WITH VALUES ABOVE 200 JUST TO NORTH. OVERALL SHOULD BE RATHER FINE BOUNDARY OF STRONGEST STORMS AS FORCING REMAINS WEAKER FARTHER SOUTH DUE TO INCREASED SUBSIDENCE WITH MID TO UPPER RIDGE OVER THE SOUTHEAST COAST. OVERALL THREAT OF HAIL AND STRONG WINDS WITH ANY STORMS THAT MAY REACH INTO OUR NORTHERN TIER COUNTIES. THE STEERING FLOW WILL PUSH ANY SHWRS/TSTMS THAT DEVELOP TOWARD THE COAST BUT THE MORE STABILIZED AIR BEHIND SEA BREEZE SHOULD KEEP THE IMMEDIATE COAST FREE OF STORMS. KEPT POPS VERY CLOSE TO PREVIOUS FORECAST WITH ONLY MINOR ADJUSTMENTS AND WILL UPDATE AS NEEDED ONCE CONVECTION FLARES. SHOULD SEE A FAIR AMOUNT OF CLOUDS AS CONVECTIVE DEBRIS CLOUDS WILL BE STEERED EAST MIXED WITH CU FIELD ACROSS THE AREA. THE STALLED BOUNDARY WILL BEGIN TO LIFT NORTH THROUGH TONIGHT AND EXPECT LOCALIZED CONVECTION TO SHUT DOWN AS HEATING OF THE DAY CUTS OFF AFTER SUNSET. THEREFORE WILL TAPER OFF POPS AFTER SUNSET LEAVING BEST CHC TO THE NORTH ALONG BOUNDARY. SHOULD BE A RELATIVELY QUIET NIGHT WITH LOWS WELL ABOVE CLIMO...RUNNING IN THE MID 60S IN A WARM AND HUMID AIRMASS. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 330 PM MONDAY...ATTENTION THROUGHOUT THE ENTIRE FORECAST PERIOD WILL FOCUS ON UNSETTLED WEATHER...INCLUDING THE THREAT FOR SEVERE WEATHER JUST AHEAD OF AN APPROACHING COLD FRONT. LATEST GUIDANCE CONTINUES TO ILLUSTRATE A LONGWAVE TROUGH ACROSS THE CONUS WITH A PERSISTENT UPPER LEVEL LOW WHICH WILL SLOWLY PROGRESS ACROSS THE MIDWEST OVER THE NEXT COUPLE OF DAYS. WARM TEMPERATURES AND SOUTHWEST FLOW WILL ALLOW FOR A MOISTURE-RICH ATMOSPHERE...AS DEWPOINTS ARE WELL IN THE 60S...TO REMAIN IN PLACE WITH HIGHS ON TUESDAY IN THE LOWER 80S ACROSS THE ENTIRE FORECAST AREA. SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGHOUT THE DAY ON TUESDAY WHICH IS IN GOOD AGREEMENT AS OUR AREA IS INCLUDED IN SPC`S SLIGHT RISK. INTO WEDNESDAY...CONDITIONS WILL CONTINUE TO PROGRESS IN INCREASE...AS IT LOOKS THE BETTER INSTABILITY AND LIFT WILL MOVE INTO THE CENTRAL SC/NC/VA AREA...WITH A HEIGHTENED POSSIBILITY OF SEVERE ESPECIALLY IN OUR WESTERN ZONES. DIFFICULTY WILL BE TIMING AS MODELS HAVE EVER SO SLIGHTLY SLOWED DOWN THE PROGRESSION OF THE SYSTEM IN PAST RUNS. HOWEVER...OVERALL ANTICIPATE MAIN THREAT TO OCCUR WEDNESDAY THROUGHOUT THE DAY WITH AMPLE DIURNAL HEATING WITH HIGHS ON WEDNESDAY AGAIN IN THE 80S...INTO EARLY THURSDAY MORNING. WILL ALSO TAKE INTO ACCOUNT THE INTERACTION OF THE SEA BREEZE AS WELL ON BOTH DAYS AND ANY OTHER WANDERING BOUNDARIES ABOUT THE AREA. THE PRIMARY THREATS WILL BE HAIL AND DAMAGING WINDS...ALONG WITH THE POSSIBILITY OF TORNADOES. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 300 PM MONDAY...THURSDAY MAY BE RATHER ACTIVE. THE UPPER RIDGE AXIS WILL BE OFFSHORE ALLOWING FOR DEEP SWRLY FLOW. SURFACE BOUNDARY AND UPPER LEVEL VORT MAXES MAY SPONSOR DEEP ENOUGH LIFT FOR FAIRLY WIDESPREAD CONVECTION. WIND FIELDS MAY BE STRONG ENOUGH FOR STORM ORGANIZATION WITH DAMAGING WIND AND/OR HAIL. MORE QUESTIONABLE WHETHER OR NOT INSTABILITY MANAGES TO DEVELOP HOWEVER. BOUNDARY PUSHES OFFSHORE THURSDAY NIGHT WHICH MAY ALLOW FOR A COOLER AND DRIER FRIDAY. TRAILING UPPER ENERGY ON SATURDAY BUT TOUGH CALL AS TO WHETHER OR NOT ENOUGH MOISTURE AROUND FOR MEANINGFUL RAIN CHANCES. DRY WNW FLOW FOR SUNDAY AND MONDAY. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... AS OF 18Z..STILL LOOKING FOR CONVECTION TO FIRE ALONG A DIFFUSE WARM FRONT THIS AFTERNOON. MOST OF THE ACTIVITY WILL BE OVER THE NORTHERN THIRD OF THE CWA...BUT COULD NOT RULE OUT WEAK CONVECTION TO THE SOUTH ALONG THE SEA BREEZE BOUNDARY. BRIEF IFR PERIODS ARE POSSIBLE...MAINLY AT LBT AND ILM. MOST OF THE ACTIVITY WILL END THIS EVENING AS THE WARM FRONT WAVES NORTH. WITH THE SOUTHWESTERLY FLOW TONIGHT...IFR STRATUS IS A REASONABLE BET. TUESDAY...BECOMING VFR WITH ANOTHER ROUND OF CONVECTION POSSIBLE BY THE END OF THE FORECAST PERIOD. EXTENDED OUTLOOK...SCATTERED AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS POSSIBLE THROUGH THURSDAY. OTHERWISE EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 230 PM MONDAY...QUIET MARINE CONDITIONS OVERALL THROUGH THIS AFTERNOON. HIGH PRESSURE REMAINS OVER THE AREA WITH LINGERING BOUNDARY LIFTING NORTH OF THE THE WATERS. GRADIENT REMAINS LIGHT WITH SOUTH TO SOUTHEAST FLOW REMAINING UNDER 10 KT THROUGH THE MORNING HOURS WITH SEAS 2 FT OR LESS. MAY SEE A FEW LINGERING SHOWERS MAKE IT OVER THE WATERS JUST ALONG NORTHERN PORTION OF LOCAL WATERS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 330 PM MONDAY...EXPECT SOUTH- SOUTHWEST FLOW TO PERSIST THROUGH THE FORECAST PERIOD WITH INCREASING WINDS WEDNESDAY INTO WEDNESDAY EVENING WHERE WINDS WILL INCREASE TO AROUND 20 TO 25 KTS...WHILE THE REMAINDER OF THE PERIOD ANTICIPATE 15 TO 20 KTS WITH ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE. AS FOR SEAS...2 TO 4 FT WITH 5 FT POSSIBLE. COULD SEE 6 TO 7 FT POSSIBLE IN THE OUTER WATERS WEDNESDAY INTO THURSDAY MORNING. ANTICIPATE CONDITIONS WILL WARRANT A SMALL CRAFT ADVISORY WEDNESDAY EVENING. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 300 PM MONDAY...PREFRONTAL FLOW REGIME ON THURSDAY PROBABLY STRONG ENOUGH TO WARRANT A SMALL CRAFT ADVISORY. A WINDSHIFT TO A MORE OFFSHORE DIRECTION THURSDAY NIGHT INTO FRIDAY PAIRED WITH A DOWNWARD TREND IN THE WIND SPEED WILL ALLOW ADVISORY TO BE DROPPED. OFFSHORE WINDS AND FAIRLY SEASONABLE SEAS CONTINUES INTO SATURDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SGL NEAR TERM...RGZ SHORT TERM...SGL LONG TERM...MBB AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
230 PM EDT MON APR 28 2014 .SYNOPSIS... HIGH PRESSURE OFF THE SOUTHEAST UNITED STATES WILL CONTINUE TO BRING MILD SOUTHERLY WINDS TO THE REGION. SHOWERS AND THUNDERSTORMS WILL INCREASE IN COVERAGE TODAY THROUGH WEDNESDAY AS A TROUGH OF LOW PRESSURE APPROACHES FROM THE WEST. ANOTHER QUICK ROUND OF RAIN IS POSSIBLE LATE FRIDAY AND SATURDAY BEFORE CONDITIONS DRY OUT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 230 PM MONDAY...INCREASINGLY WARM AND MORE UNSTABLE AIR MASS WITH TEMPS INTO THE 80S MOST PLACES. MODELS STILL SHOW MID TO UPPER RIDGE LINED UP THE SOUTHEAST COAST WHICH SHOULD HELP TO INHIBIT SOME OF THE STRONGEST CONVECTION RUNNING SOUTH...BUT AS TEMPS WARMED INTO THE 80S AND DEWPOINTS INTO THE MID 60S CLOSER TO 70 OVER SOUTH CAROLINA. HRRR AND RUC SHOWING BEST CAPE LINED UP INLAND FROM SOUTH TO NORTH TOWARD DARLINGTON AND MARLBORO...BUT MAIN FOCUS OF STRONGER CONVECTION WILL BE ALONG THE LINGERING FRONTAL BOUNDARY JUST TO THE NORTH OF LOCAL FORECAST AREA. EXPECT SCT CONVECTION OVER THE AREA WITH MAIN FOCUS ALONG SEA BREEZE CONVERGENT BOUNDARY AND RUNNING ALONG LINGERING FRONTAL BOUNDARY. JUST NORTH OF BOUNDARY STILL SEEING TEMPS NOT EVEN REACHING 70 WITH COOLER AIR WEDGED IN. BEST HELICITY WILL RUN ALONG WARM FRONT WITH VALUES ABOVE 200 JUST TO NORTH. OVERALL SHOULD BE RATHER FINE BOUNDARY OF STRONGEST STORMS AS FORCING REMAINS WEAKER FARTHER SOUTH DUE TO INCREASED SUBSIDENCE WITH MID TO UPPER RIDGE OVER THE SOUTHEAST COAST. THE STEERING FLOW WILL PUSH ANY SHWRS/TSTMS THAT DEVELOP TOWARD THE COAST BUT THE MORE STABILIZED AIR BEHIND SEA BREEZE SHOULD KEEP THE IMMEDIATE COAST FREE OF STORMS. KEPT POPS VERY CLOSE TO PREVIOUS FORECAST WITH ONLY MINOR ADJUSTMENTS AND WILL UPDATE AS NEEDED ONCE CONVECTION FLARES. SHOULD SEE CLOUDS BLANKET MUCH OF THE AREA THROUGH THIS AFTERNOON AS CONVECTIVE DEBRIS CLOUDS WILL BE STEERED EAST AND HIGH CLOUDS WILL SPILL OVER THE MID TO UPPER RIDGE INTO LOCAL AREA. THE STALLED BOUNDARY WILL BEGIN TO LIFT NORTH THROUGH TONIGHT AND EXPECT LOCALIZED CONVECTION TO SHUT DOWN AS HEATING OF THE DAY CUTS OFF AFTER SUNSET. THEREFORE WILL TAPER OFF POPS AFTER SUNSET LEAVING BEST CHC TO THE NORTH ALONG BOUNDARY. SHOULD BE A RELATIVELY QUIET NIGHT WITH ABUNDANT CLOUD COVER AND LOWS WELL ABOVE CLIMO...RUNNING IN THE MID 60S IN A WARM AND HUMID AIRMASS. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY...ALL EYES WILL BE ON THE SYSTEM NOW MOVING ACROSS THE CENTRAL U.S AS IT MAKES ITS MOVE ON THE EAST COAST. THE GFS...WHICH I HAVE BEEN LEANING TOWARD FOR A FEW CYCLES NOW REMAINS CONSISTENT WITH THE BEST LIFT AND MOISTURE COUPLING LATE WEDNESDAY AND INTO THE MORNING HOURS THURSDAY. I HAVE INCREASED POPS BASICALLY ACROSS THE BOARD MORE SO FOR THE LATER PERIODS. SPC CONTINUES TO HAVE THE AREA IN A SLIGHT RISK FOR BOTH DAYS. TEMPERATURE GUIDANCE IS IN GOOD AGREEMENT OUTSIDE OF DAYTIME HIGHS FOR WEDNESDAY WITH THE NAM/MET NUMBERS ONCE AGAIN COOLER. INHERITED BLEND WILL SUFFICE FOR NOW. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 3 AM MONDAY...THE FOCUS FOR THE EXTENDED BEGINS TO SHIFT FROM THE LONG ADVERTISED SYSTEM THAT IS CURRENTLY PLODDING ACROSS THE CENTRAL U.S TO A SECONDARY WAVE LATE IN THE PERIOD. THE LATEST MEDIUM RANGE GUIDANCE CONTINUES TO ADVERTISE A WET SCENARIO MAINLY ALONG THE COAST. I HAVE TWEAKED THE POPS FOR SATURDAY TO REPRESENT MORE OF A COASTAL SYSTEM ALTHOUGH THERE IS STILL PLENTY OF TIME FOR THIS TO CHANGE. POPS REMAIN IN THE FORECAST FOR THURSDAY AND FRIDAY MOSTLY VIA THE LOWER CONFIDENCE IN THE PROGRESS OF THE INITIAL SYSTEM. NO CHANGES TO THE TEMPERATURE FORECAST. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 18Z..STILL LOOKING FOR CONVECTION TO FIRE ALONG A DIFFUSE WARM FRONT THIS AFTERNOON. MOST OF THE ACTIVITY WILL BE OVER THE NORTHERN THIRD OF THE CWA...BUT COULD NOT RULE OUT WEAK CONVECTION TO THE SOUTH ALONG THE SEA BREEZE BOUNDARY. BRIEF IFR PERIODS ARE POSSIBLE...MAINLY AT LBT AND ILM. MOST OF THE ACTIVITY WILL END THIS EVENING AS THE WARM FRONT WAVES NORTH. WITH THE SOUTHWESTERLY FLOW TONIGHT...IFR STRATUS IS A REASONABLE BET. TUESDAY...BECOMING VFR WITH ANOTHER ROUND OF CONVECTION POSSIBLE BY THE END OF THE FORECAST PERIOD. EXTENDED OUTLOOK...SCATTERED AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS POSSIBLE THROUGH THURSDAY. OTHERWISE EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 230 PM MONDAY...QUIET MARINE CONDITIONS OVERALL THROUGH THIS AFTERNOON. HIGH PRESSURE REMAINS OVER THE AREA WITH LINGERING BOUNDARY LIFTING NORTH OF THE THE WATERS. GRADIENT REMAINS LIGHT WITH SOUTH TO SOUTHEAST FLOW REMAINING UNDER 10 KT THROUGH THE MORNING HOURS WITH SEAS 2 FT OR LESS. MAY SEE A FEW LINGERING SHOWERS MAKE IT OVER THE WATERS JUST ALONG NORTHERN PORTION OF LOCAL WATERS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY...A SOUTH TO OCCASIONALLY SOUTHEAST FLOW WILL PREVAIL THROUGH THE PERIOD. THE STRONGEST WINDS SHOULD OCCUR LATE WEDNESDAY WHEN A RANGE OF 20-25 KNOTS. FOR THE MOST PART A RANGE OF 15-20 KNOTS SHOULD BE FAIRLY PERSISTENT BEFORE THIS. SEAS WILL GRADUALLY BUILD FROM AN INITIAL RANGE OF 1-3 FEET TO 3-5 AND POSSIBLY 4-6 FEET BY THE END OF SECOND HALF OF THE PERIOD. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 3 AM MONDAY...THE MAIN ISSUE FOR THE MARINE COMMUNITY WILL BE THE TIMING OF THE WIND SHIFT WITH THE FRONT ASSOCIATED WITH THE MAIN INITIAL SYSTEM. THIS SHOULD OCCUR LATE THURSDAY/EARLY FRIDAY ALTHOUGH CONFIDENCE IS LOW DUE TO THE SLOW NATURE OF THIS SYSTEM. PRECEDING THIS...EXPECT A SOUTHWEST FLOW OF 15-20 KNOTS. FOR FRIDAY EXPECT A LIGHTER AND MORE VARIABLE FLOW. SIGNIFICANT SEAS WILL BE HOVERING AT OR JUST BELOW SMALL CRAFT CRITERIA THURSDAY 3-5 FEET DROPPING SLIGHTLY FRIDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RGZ SHORT TERM...SHK LONG TERM...SHK AVIATION...DL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EDT MON APR 28 2014 .SYNOPSIS...A STALLED SURFACE BOUNDARY ACROSS CENTRAL NC WILL LIFT NORTHWARD AS A WARM FRONT THIS AFTERNOON. A WARM...MOIST AND UNSTABLE AIR MASS WILL RESIDE OVER CENTRAL NC TONIGHT THROUGH WEDNESDAY NIGHT. A SERIES OF UPPER LEVEL DISTURBANCES WILL INTERACT WITH THIS AIR MASS TRIGGERING SHOWERS AND THUNDERSTORMS. && .NEAR TERM /THROUGH TUESDAY NIGHT/... AS OF 1040 AM MONDAY... A WEAK COLD FRONT AND SHALLOW STABLE AIRMASS SETTLED SOUTH THROUGH THE AREAS OVERNIGHT...MAKING IT ESSENTIALLY TO THE SC BORDER AND CREATING A RATHER LARGE GRADIENT IN TEMPS AND DEWPOINTS. THE PARENT SURFACE HIGH BEHIND THE FRONT WILL CONTINUE TO SUPPLY A NORTHEASTERLY WIND TODAY...BUT WITH CLEARING ALREADY OCCURRING ACROSS THE SOUTHERN PIEDMONT AND A SOUTHWESTERLY WIND AT 925MB...THE BOUNDARY SHOULD MIX BACK TO THE NORTH TODAY. HIGHS FOR TODAY ARE TOUGH GIVEN THE VARYING CLOUD COVER AND SLOWLY VEERING SURFACE WINDS ACROSS THE SOUTH. TEMPS OVER PORTION OF SC HAVE ALREADY JUMPED INTO THE MID AND UPPER 70S. ACROSS THE NORTH THE AMOUNT OF SUN IS A BIT MORE UNCERTAIN...WITH ADDITIONAL CLOUD COVER MOVING EAST ACROSS THE BLUE RIDGE. ADJUSTMENTS TO TEMP TRENDS YIELDS MID 60S NORTH TO LOWER 80S SOUTH. REGARDING CONVECTION... THE MAIN LIMITING FACTOR IS THE SHORTWAVE RIDGE OVERHEAD...BUT FORECAST SOUNDINGS SUGGEST HEATING AND MOISTURE RECOVER WILL BE ABLE TO OVERCOME THE MID-LEVEL CAP. THE LATEST RAP RUNS SHOW AN INSTABILITY AXIS ON THE ORDER OF 500-1000 J/KG MLCAPE NOSING NORTH ACROSS THE SOUTHERN PIEDMONT BY MIDDAY...WITH DESTABILIZATION TO THE EAST CROSS THE SANDHILLS AND SOUTHERN COASTAL PLAIN WITH TIME. THE SEEMS TO MESH WELL WITH SATELLITE TRENDS AND DEWPOINTS RECOVERING INTO THE MID TO UPPER 60S....SO AREAS SOUTH OF HWY 64 LOOK TO MOST FAVORABLE FOR CONVECTION THIS AFTERNOON. BULK SHEAR WILL BE STRONGER TO THE NORTH...BUT GUIDANCE SUGGESTS AS MUCH AS 30KT WHICH COULD SUPPORT SOME MULTICELL CLUSTERS WITH A GENERAL MOTION FROM WEST TO EAST. THE MAIN THREAT FROM STORMS WILL BE DAMAGING WINDS...THOUGH STORMS FARTHER NORTH IN THE VICINITY OF THE RETREATING SURFACE BOUNDARY AND BACKED SURFACE WINDS WILL ENCOUNTER GREATER SHEAR AND HAVE A BETTER CHANCE OF ROTATING. AGAIN...THE THREAT OF SEVERE WEATHER IS CONDITIONED UPON DEVELOPMENT OF STORMS...WHICH SHOULD BE MOSTLY SCATTERED IN NATURE. -SMITH TONIGHT...SFC FRONT PROJECTED TO BE STALLED ACROSS THE NORTHERN COUNTIES. WEAK CONVERGENCE ALONG THIS FEATURE WILL MAINTAIN A THREAT FOR SCATTERED SHOWERS THROUGH THE NIGHT. EXPECT SHOWERS TO BE MORE ISOLATED ACROSS THE SOUTH. RATHER MILD TONIGHT WITH MIN TEMPS NO LOWER THAN THE MID 60S ACROSS THE SOUTH...TRENDING TO THE UPPER 50S/NEAR 60 SOUTH. TUESDAY AND TUESDAY NIGHT...ACTIVE WEATHER PATTERN APPEARS LIKELY ACROSS CENTRAL NC WITH A CHANCE FOR MORE THAN ONE ROUND OF STRONG TO SEVERE STORMS. THE DEEP LOW PRESSURE SYSTEM OVER THE CENTRAL PLAINS/MID MS VALLEY WILL REMAIN NEARLY STATIONARY THIS PERIOD. A SERIES OF UPPER LEVEL DISTURBANCES WILL ROTATE AROUND THIS LOW SIMILAR TO SPOKES AROUND TEH CENTER OF A WHEEL. AS A DISTURBANCE CROSSES CENTRAL NC AND INTERACTS WITH THE WARM MOIST UNSTABLE AIR MASS IN PLACE...EXPECT SCATTERED TO NUMEROUS SHOWERS AND STORMS TO OCCUR. BASED ON MODEL TIMING 9WHICH WILL LIKELY CHANGE OR ADJUST IN LATER MODEL RUNS)...APPEARS FIRST ROUND OF SHOWERS AND STORMS WILL CROSS THE REGION TUESDAY AFTERNOON WITH ANOTHER ROUND LATE TUESDAY NIGHT. WIND PROFILES TUESDAY AFTERNOON ARE SUPPORTIVE OF STRONG UPDRAFTS WITH LOW LEVEL HELICITY VALUES IN THE 150-300 M2/S2 RANGE LATE TUESDAY INTO TUESDAY NIGHT. IN ADDITION...STRONG LIFT EXPECTED THROUGH TEH COLUMN AS CENTRAL NC WILL BE IN THE RIGHT ENTRANCE REGION OF A 100- 110KT UPPER JET. THUS...POTENTIAL FOR A FEW SEVERE STORMS TUESDAY AFTERNOON AND TUESDAY NIGHT WITH A FEW TORNADOES PROBABLE. ALSO...POTENTIAL FOR STORMS TO REPEAT ACROSS THE SAME AREA. WITH PRECIP WATER VALUES 1.5-1.75 INCHES PROJECTED...THIS SUGGEST THAT THE HEAVY SHOWERS AND STORMS WILL BE CAPABLE FOR PRODUCING HEAVY RAIN...LEADING TO FLOODING IN URBANIZED AREAS (AND EVENTUALLY SOME RIVER FLOODING). MAX TEMPS TUESDAY DEPENDENT UPON WHETHER THE SFC BOUNDARY LIFTS ENTIRELY INTO VA OR LAGS ALONG OUR NORTHERN COUNTIES. APPEARS TO BE ENOUGH OF A SLY FETCH JUST ABOVE THE SFC TO PUSH THE BOUNDARY NWD SO HAVE LEANED TOWARD THE WARMER GUIDANCE FOR TUESDAY. MAX TEMPS MID 70S FAR NORTH-NW TO THE LOWER 80S SOUTH. MIN TEMPS TUESDAY NIGHT LOW 60S FAR NORTH-NW TO MID-UPPER 60S ELSEWHERE. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 240 PM MONDAY... FOR WED/WED NIGHT: LOOKS LIKE ANOTHER ROUND OF STRONG TO POSSIBLY SEVERE STORMS LATE WED INTO WED NIGHT... ALTHOUGH THE DEGREE OF THREAT WILL DEPEND LARGELY ON THE EXTENT OF CLOUDINESS WED MORNING AND ITS IMPACT ON INSTABILITY HEADING THROUGH THE DAY. THE POTENT MID LEVEL VORTEX WILL WOBBLE SLOWLY EASTWARD ACROSS THE UPPER MIDWEST/WRN GREAT LAKES AS AN 80 KT MID LEVEL JET STREAK TRACKS UP ALONG THE SRN/CENTRAL APPALACHIANS/FOOTHILLS... WITH UPPER DIVERGENCE MAXIMIZING OVER THE ERN HALF OF NC LATE IN THE DAY. PROVIDED THAT TUE NIGHT`S CONVECTIVE DEBRIS CLOUDS CAN CLEAR OUT OF CENTRAL/ERN NC BY MID AFTERNOON AND ALLOW FOR SOME INSOLATION... WE MAY ACHIEVE MUCAPE VALUES OF 1000-2000 J/KG COINCIDENT WITH DEEP LAYER SHEAR OF 30-40 KTS. FORECAST HODOGRAPHS REMAIN BROADLY CURVED WED WITH 0-3 KM HELICITY OVER 200 M2/S2... EHI EXCEEDING 2.5... AND VGP OVER 0.3 M/S2... SUGGESTING ROTATING UPDRAFTS ARE A GOOD BET GIVEN ENOUGH ASCENT VIA DYNAMIC AND THERMODYNAMIC PROCESSES. WILL CONTINUE TO HIGHLIGHT THE SEVERE THREAT FOR WED AFTERNOON/EVENING FOR ALL OF CENTRAL NC... FOR THE POSSIBILITY OF DAMAGING WIND- PRODUCING BOWING SEGMENTS AND/OR SUPERCELLS PRODUCING A FEW TORNADOES. EQUALLY AS CONCERNING IS THE THREAT FOR REPEATED BOUTS OF TRAINING CONVECTIVE BANDS/CLUSTERS GENERATING EXTENDED PERIODS OF HEAVY RAINFALL... AS MUCH AS 2-4 INCHES FROM TUE THROUGH WED NIGHT. LARGE SCALE MODELS AGREE ON THIS PATTERN WITH THE GREATEST TOTALS FROM THE NC MOUNTAINS THROUGH THE PIEDMONT... AND GIVEN PROJECTIONS OF PW VALUES WELL OVER 200% OF NORMAL FROM LATE TUE LASTING THROUGH WED NIGHT AND A DEEP WARM LAYER OVER 3.5 KM FAVORING WARM RAIN PROCESSES... IT IS NEARLY CERTAIN THAT THE FLOODING THREAT WILL EXTEND THROUGH WED NIGHT. CONSIDERABLE STREET FLOODING... SWOLLEN CREEKS... AND SIGNIFICANT RISES ON MAINSTEM RIVERS ARE ALL POSSIBLE. MAX TEMPS ARE A TOUGH CALL GIVEN THE UNCERTAINTY AS TO HOW MUCH SUNSHINE WE`LL GET... BUT MODEL TRENDS AND THICKNESSES WITH STRONG WARM AIR ADVECTION SUPPORT RAISING HIGHS A BIT TO 77-84. THE COLD FRONT IS LIKELY TO SLOW TO A CRAWL AS IT EASES EASTWARD INTO THE FAR WRN PIEDMONT WED NIGHT AS IT BECOMES PARALLEL TO THE STEERING FLOW AND LOSES FORWARD MOMENTUM. THE LOSS OF HEATING AND THE WANING DYNAMIC FORCING AS THE MID LEVEL FLOW FLATTENS SHOULD RESULT IN A DECREASING SEVERE THREAT OVERNIGHT. THE STRONG LOW LEVEL MOISTURE TRANSPORT WILL SLOWLY SHIFT EASTWARD INTO ERN NC LATE... AS SHOULD THE GREATEST PW VALUES... LIKELY RESULTING IN A DIMINISHING FLOODING THREAT LATE (ALTHOUGH STREET AND RIVER FLOODING MAY BE ONGOING). WITH WARM SW FLOW AND PLENTIFUL CLOUD COVER... EXPECT MILD LOWS OF 60-67. FOR THU/THU NIGHT: WHAT APPEARS TO BE DEPICTED AS A PREFRONTAL TROUGH SHIFTS INTO THE COASTAL AREAS OF NC BY THU MORNING WITH THE PRIMARY FRONT STILL HANGING BACK OVER WRN NC WHILE BECOMING INCREASINGLY DIFFUSE. THE LOW LEVEL MOISTURE TRANSPORT AND PW REMAIN ELEVATED OVER ERN NC... NECESSITATING A CONTINUED GOOD CHANCE OF SHOWERS AND ISOLATED STORMS IN THE COASTAL PLAIN THROUGH THU... WHILE THE NW CWA SHOULD SEE GENERALLY DRY WEATHER AND FAIR SKIES. SHORTWAVE ENERGY RIDING NE OVER THE SRN GREAT LAKES/ST LAWRENCE VALLEY SHOULD HELP PUSH THE SURFACE FRONT TO OUR SE BY THU NIGHT... LEADING TO DIMINISHED RAIN CHANCES AS LOW LEVEL FLOW BECOMES MORE WESTERLY OR WNW. HIGHS 75-82. LOWS FROM 49 NW TO 57 EAST. -GIH && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 305 AM MONDAY... GIVEN THE MID LEVEL TROUGH AXIS IS EXPECTED TO REMAIN TO OUR WEST UNTIL LATE SATURDAY/SATURDAY NIGHT WITH THE SURFACE FRONT EXPECTED TO LINGER NEAR THE COAST THROUGH SATURDAY MORNING... EXPECT WE COULD SEE SOME MORE SHOWERS AND EVEN SOME STORMS... WITH THE HIGHEST PROBABILITIES ACROSS OUR FAR EAST/SOUTHEASTERN AREAS. DRY WEATHER IS EXPECTED TO RETURN FOR SUNDAY. EXPECT HIGH TEMPS WILL BE IN THE 70S TO NEAR 80 EAST ON THURSDAY... WITH HIGH TEMPS GENERALLY AROUND 70 TO THE MID 70S FOR FRIDAY THROUGH SUNDAY. LOW TEMPS WILL BE IN THE 40S AND 50S FOR THIS TIME FRAME. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 150 PM MONDAY... UNSETTLED WEATHER WILL PERSIST THROUGH MIDWEEK... AS A POWERFUL STORM SYSTEM HOLDS OVER THE CENTRAL STATES... WITH A WARM FRONT EXTENDING EASTWARD THROUGH OUR REGION AND A MOIST LOW LEVEL FLOW FROM THE SOUTHWEST GRADUALLY DEVELOPING OVER NC. AVIATION CONDITIONS NOW VARYING FROM MVFR TO LOW-END VFR ARE EXPECTED TO PERSIST THROUGH THIS AFTERNOON... WITH VFR CONDITIONS DOMINATING AT MOST SITES AFTER 20Z. CONDITIONS ARE LIKELY TO WORSEN BY EARLY THIS EVENING WITH A GOOD CHANCE OF MVFR VSBYS IN SHOWERS AND STORMS. THIS IS LIKELY TO BE FOLLOWED BY LOWERING CIGS TO IFR/LIFR LATE TONIGHT AS LOW STRATUS FORMS OVER THE AREA. WHILE WE`RE UNLIKELY TO MEET LLWS CRITERIA TONIGHT... WINDS THAT ARE FROM THE SE AT 5-10 KTS AT THE SURFACE WILL VEER WITH HEIGHT TO SW AT 25-30 KTS AROUND 1500 FT AGL LATE TONIGHT... WHICH MAY CAUSE DIFFICULTY IN HANDLING SOME AIRCRAFT. THE THREAT OF PATCHY SHOWERS AND A STORM OR TWO WILL LINGER OVERNIGHT... THEN MORE ORGANIZED AND STRONGER STORMS ARE EXPECTED TO FORM TUE AFTERNOON... AS CIGS RISE TO MVFR TOWARD THE END OF THE TAF VALID PERIOD... WITH SURFACE WINDS BECOMING SOUTHERLY OR SOUTHWESTERLY AND INCREASING TO AROUND 15 KTS AS THE WARM FRONTAL ZONE SURGES NORTH OF CENTRAL NC. LOOKING BEYOND 18Z TUE... AVIATION INTERESTS SHOULD CLOSELY MONITOR THE LATEST CONDITIONS TUE AFTERNOON THROUGH WED EVENING... AS THERE IS A HEIGHTENED RISK OF STRONG TO SEVERE STORMS... ANY OF WHICH COULD PRODUCE DANGEROUS AVIATION WEATHER. OTHERWISE... EXPECT MAINLY MVFR CIGS THROUGH THE REST OF TUE AFTERNOON WITH GUSTY WINDS FROM THE SW AND A PEAK IN STORM COVERAGE INTO TUE EVENING. IFR/LIFR CIGS/VSBYS LIKELY TO RESUME AFTER 05Z WED... IMPROVING SLOWLY TO MVFR BY 16Z WED WITH ANOTHER PEAK IN STORM COVERAGE EXPECTED LATE WED AFTERNOON INTO THE EVENING. EXPECT A COLD FRONT TO SHIFT INTO CENTRAL NC AND WEAKEN EARLY THU... RESULTING IN PROBABLE VFR CONDITIONS AT GSO/INT AND MVFR/IFR HOLDING AT RDU/RWI/FAY THU. CONTINUED UNSETTLED FRI ESPECIALLY IN EASTERN TERMINALS WITH POSSIBLE MVFR CONDITIONS PERSISTING. VFR CONDITIONS EXPECTED SAT. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...WSS/SMITH SHORT TERM...HARTFIELD LONG TERM...BSD AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
150 PM EDT MON APR 28 2014 .SYNOPSIS...A STALLED SURFACE BOUNDARY ACROSS CENTRAL NC WILL LIFT NORTHWARD AS A WARM FRONT THIS AFTERNOON. A WARM...MOIST AND UNSTABLE AIR MASS WILL RESIDE OVER CENTRAL NC TONIGHT THROUGH WEDNESDAY NIGHT. A SERIES OF UPPER LEVEL DISTURBANCES WILL INTERACT WITH THIS AIR MASS TRIGGERING SHOWERS AND THUNDERSTORMS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1040 AM MONDAY... A WEAK COLD FRONT AND SHALLOW STABLE AIRMASS SETTLED SOUTH THROUGH THE AREAS OVERNIGHT...MAKING IT ESSENTIALLY TO THE SC BORDER AND CREATING A RATHER LARGE GRADIENT IN TEMPS AND DEWPOINTS. THE PARENT SURFACE HIGH BEHIND THE FRONT WILL CONTINUE TO SUPPLY A NORTHEASTERLY WIND TODAY...BUT WITH CLEARING ALREADY OCCURRING ACROSS THE SOUTHERN PIEDMONT AND A SOUTHWESTERLY WIND AT 925MB...THE BOUNDARY SHOULD MIX BACK TO THE NORTH TODAY. HIGHS FOR TODAY ARE TOUGH GIVEN THE VARYING CLOUD COVER AND SLOWLY VEERING SURFACE WINDS ACROSS THE SOUTH. TEMPS OVER PORTION OF SC HAVE ALREADY JUMPED INTO THE MID AND UPPER 70S. ACROSS THE NORTH THE AMOUNT OF SUN IS A BIT MORE UNCERTAIN...WITH ADDITIONAL CLOUD COVER MOVING EAST ACROSS THE BLUE RIDGE. ADJUSTMENTS TO TEMP TRENDS YIELDS MID 60S NORTH TO LOWER 80S SOUTH. REGARDING CONVECTION... THE MAIN LIMITING FACTOR IS THE SHORTWAVE RIDGE OVERHEAD...BUT FORECAST SOUNDINGS SUGGEST HEATING AND MOISTURE RECOVER WILL BE ABLE TO OVERCOME THE MID-LEVEL CAP. THE LATEST RAP RUNS SHOW AN INSTABILITY AXIS ON THE ORDER OF 500-1000 J/KG MLCAPE NOSING NORTH ACROSS THE SOUTHERN PIEDMONT BY MIDDAY...WITH DESTABILIZATION TO THE EAST CROSS THE SANDHILLS AND SOUTHERN COASTAL PLAIN WITH TIME. THE SEEMS TO MESH WELL WITH SATELLITE TRENDS AND DEWPOINTS RECOVERING INTO THE MID TO UPPER 60S....SO AREAS SOUTH OF HWY 64 LOOK TO MOST FAVORABLE FOR CONVECTION THIS AFTERNOON. BULK SHEAR WILL BE STRONGER TO THE NORTH...BUT GUIDANCE SUGGESTS AS MUCH AS 30KT WHICH COULD SUPPORT SOME MULTICELL CLUSTERS WITH A GENERAL MOTION FROM WEST TO EAST. THE MAIN THREAT FROM STORMS WILL BE DAMAGING WINDS...THOUGH STORMS FARTHER NORTH IN THE VICINITY OF THE RETREATING SURFACE BOUNDARY AND BACKED SURFACE WINDS WILL ENCOUNTER GREATER SHEAR AND HAVE A BETTER CHANCE OF ROTATING. AGAIN...THE THREAT OF SEVERE WEATHER IS CONDITIONED UPON DEVELOPMENT OF STORMS...WHICH SHOULD BE MOSTLY SCATTERED IN NATURE. -SMITH TONIGHT...SFC FRONT PROJECTED TO BE STALLED ACROSS THE NORTHERN COUNTIES. WEAK CONVERGENCE ALONG THIS FEATURE WILL MAINTAIN A THREAT FOR SCATTERED SHOWERS THROUGH THE NIGHT. EXPECT SHOWERS TO BE MORE ISOLATED ACROSS THE SOUTH. RATHER MILD TONIGHT WITH MIN TEMPS NO LOWER THAN THE MID 60S ACROSS THE SOUTH...TRENDING TO THE UPPER 50S/NEAR 60 SOUTH. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... AS OF 330 AM MONDAY... TUESDAY AND TUESDAY NIGHT...ACTIVE WEATHER PATTERN APPEARS LIKELY ACROSS CENTRAL NC WITH A CHANCE FOR MORE THAN ONE ROUND OF STRONG TO SEVERE STORMS. THE DEEP LOW PRESSURE SYSTEM OVER THE CENTRAL PLAINS/MID MS VALLEY WILL REMAIN NEARLY STATIONARY THIS PERIOD. A SERIES OF UPPER LEVEL DISTURBANCES WILL ROTATE AROUND THIS LOW SIMILAR TO SPOKES AROUND TEH CENTER OF A WHEEL. AS A DISTURBANCE CROSSES CENTRAL NC AND INTERACTS WITH THE WARM MOIST UNSTABLE AIR MASS IN PLACE...EXPECT SCATTERED TO NUMEROUS SHOWERS AND STORMS TO OCCUR. BASED ON MODEL TIMING 9WHICH WILL LIKELY CHANGE OR ADJUST IN LATER MODEL RUNS)...APPEARS FIRST ROUND OF SHOWERS AND STORMS WILL CROSS THE REGION TUESDAY AFTERNOON WITH ANOTHER ROUND LATE TUESDAY NIGHT. WIND PROFILES TUESDAY AFTERNOON ARE SUPPORTIVE OF STRONG UPDRAFTS WITH LOW LEVEL HELICITY VALUES IN THE 150-300 M2/S2 RANGE LATE TUESDAY INTO TUESDAY NIGHT. IN ADDITION...STRONG LIFT EXPECTED THROUGH TEH COLUMN AS CENTRAL NC WILL BE IN THE RIGHT ENTRANCE REGION OF A 100- 110KT UPPER JET. THUS...POTENTIAL FOR A FEW SEVERE STORMS TUESDAY AFTERNOON AND TUESDAY NIGHT WITH A FEW TORNADOES PROBABLE. ALSO...POTENTIAL FOR STORMS TO REPEAT ACROSS THE SAME AREA. WITH PRECIP WATER VALUES 1.5-1.75 INCHES PROJECTED...THIS SUGGEST THAT THE HEAVY SHOWERS AND STORMS WILL BE CAPABLE FOR PRODUCING HEAVY RAIN...LEADING TO FLOODING IN URBANIZED AREAS (AND EVENTUALLY SOME RIVER FLOODING). MAX TEMPS TUESDAY DEPENDENT UPON WHETHER THE SFC BOUNDARY LIFTS ENTIRELY INTO VA OR LAGS ALONG OUR NORTHERN COUNTIES. APPEARS TO BE ENOUGH OF A SLY FETCH JUST ABOVE THE SFC TO PUSH THE BOUNDARY NWD SO HAVE LEANED TOWARD THE WARMER GUIDANCE FOR TUESDAY. MAX TEMPS MID 70S FAR NORTH-NW TO THE LOWER 80S SOUTH. MIN TEMPS TUESDAY NIGHT LOW 60S FAR NORTH-NW TO MID-UPPER 60S ELSEWHERE. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 305 AM MONDAY... WEDNESDAY AND WEDNESDAY NIGHT: THE DEEP MID LEVEL LOW AND SURFACE LOW ARE EXPECTED TO LINGER ACROSS THE UPPER MIDWEST AND GREAT LAKES REGION ON WEDNESDAY AND WEDNESDAY NIGHT WITH THE SYSTEM QUITE WRAPPED UP AND OCCLUDED. THIS WILL RESULT IN STRONG SOUTH- SOUTHWESTERLY MID LEVEL FLOW ACROSS OUR REGION ALONG WITH A SLOW APPROACHING COLD FRONT. EXPECT THE HEAVIEST AND MORE WIDESPREAD PRECIP WILL BE ACROSS WESTERN PORTIONS OF THE AREA ON WEDNESDAY. THIS MAY LEAD TO A DECENT DIFFERENTIAL HEATING BOUNDARY SETTING UP ACROSS THE REGION. GIVEN DEEP LAYER SHEAR VALUES ARE EXPECTED TO BE AROUND 35 TO 50 KTS WEDNESDAY AFTERNOON INTO THE EVENING... WITH THE POTENTIAL FOR UPWARDS OF 1000 TO 2000 J/KG OF MLCAPE FOR LOCATIONS THAT WARM UP NICELY AND SEE A BIT LESS RAIN... EXPECT WE WILL HAVE A THREAT FOR SEVERE STORMS. IF WE INDEED SEE A BOUNDARY SET UP OR LINGERING BOUNDARY FROM EARLIER THEN WE COULD SEE AN INCREASE RISK FOR TORNADOES... AS 0-1 KM SRH VALUES ARE EXPECTED TO BE IN THE 150 TO 400 M2/S2 RANGE WITH RIGHT LOOPING HODOGRAPHS. GIVEN THE IMPRESSIVE DEEP LAYER SHEAR AND POSSIBLE MODERATE INSTABILITY... SUPERCELLS WILL BE POSSIBLE... WITH DAMAGING WIND AND LARGE HAIL AS WELL. IN ADDITION... WITH PW VALUES EXPECTED TO BE AROUND 1.5 INCHES (WELL ABOVE NORMAL FOR THIS TIME OF YEAR) EXPECT THE SHOWERS AND STORMS WILL PRODUCE HEAVY RAIN. THIS COUPLED WITH THE SLOW MOVING FRONT WILL POSE A RISK FOR FLASH FLOODING AND RIVER FLOODING... ESPECIALLY ACROSS THE WESTERN PIEDMONT (WHERE SEVERAL DAYS WORTH OF MODERATE TO HEAVY RAIN MAY LEAD TO 3 TO 4+ INCHES OF RAINFALL). THE MAIN AXIS OF SHOWERS AND STORMS WILL BEGIN TO SLOWLY SHIFT EASTWARD BY EARLY THURSDAY MORNING AS THE SURFACE COLD FRONT BEGINS TO PUSH THROUGH THE AREA... WITH THE MAIN AREAS OF SHOWERS AND STORMS FROM GENERALLY RALEIGH EASTWARD BY MIDNIGHT THURSDAY. TEMPS ON WEDNESDAY WILL BE TRICKY AND DRIVEN BY CLOUDS AND PRECIP. FOR NOW WILL SHOW HIGHS IN THE WEST (WHERE THE MOST RAIN IS EXPECTED) IN AROUND THE MID 70S (CLOSER TO THE COOL SIDE OF GUIDANCE) TO THE LOWER 80S SE. LOWS THURSDAY MORNING SHOULD REMAIN MILD WITH AT LEAST CONTINUED LINGERING LOW LEVEL CLOUD COVER. THUS... WILL GO WITH LOWS IN THE LOWER 60S WEST TO UPPER 60S EAST. THURSDAY THROUGH SUNDAY: THE COLD FRONT WILL SLOWLY MOVE ACROSS CENTRAL NC WEDNESDAY NIGHT/THURSDAY MORNING... WITH A FINAL SECONDARY PUSH NOT COMING THROUGH UNTIL THURSDAY NIGHT/FRIDAY MORNING. HOWEVER... WITH MID LEVEL DRY AIR FILTERING INTO THE WESTERN/NORTHWESTERN HALF OF THE CWA ON THURSDAY EXPECT WE WILL BEGIN TO DRY OUT A BIT IN PIEDMONT ON THURSDAY INTO THURSDAY NIGHT. GIVEN THE MID LEVEL TROUGH AXIS IS EXPECTED TO REMAIN TO OUR WEST UNTIL LATE SATURDAY/SATURDAY NIGHT WITH THE SURFACE FRONT EXPECTED TO LINGER NEAR THE COAST THROUGH SATURDAY MORNING... EXPECT WE COULD SEE SOME MORE SHOWERS AND EVEN SOME STORMS... WITH THE HIGHEST PROBABILITIES ACROSS OUR FAR EAST/SOUTHEASTERN AREAS. DRY WEATHER IS EXPECTED TO RETURN FOR SUNDAY. EXPECT HIGH TEMPS WILL BE IN THE 70S TO NEAR 80 EAST ON THURSDAY... WITH HIGH TEMPS GENERALLY AROUND 70 TO THE MID 70S FOR FRIDAY THROUGH SUNDAY. LOW TEMPS WILL BE IN THE 40S AND 50S FOR THIS TIME FRAME. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 150 PM MONDAY... UNSETTLED WEATHER WILL PERSIST THROUGH MIDWEEK... AS A POWERFUL STORM SYSTEM HOLDS OVER THE CENTRAL STATES... WITH A WARM FRONT EXTENDING EASTWARD THROUGH OUR REGION AND A MOIST LOW LEVEL FLOW FROM THE SOUTHWEST GRADUALLY DEVELOPING OVER NC. AVIATION CONDITIONS NOW VARYING FROM MVFR TO LOW-END VFR ARE EXPECTED TO PERSIST THROUGH THIS AFTERNOON... WITH VFR CONDITIONS DOMINATING AT MOST SITES AFTER 20Z. CONDITIONS ARE LIKELY TO WORSEN BY EARLY THIS EVENING WITH A GOOD CHANCE OF MVFR VSBYS IN SHOWERS AND STORMS. THIS IS LIKELY TO BE FOLLOWED BY LOWERING CIGS TO IFR/LIFR LATE TONIGHT AS LOW STRATUS FORMS OVER THE AREA. WHILE WE`RE UNLIKELY TO MEET LLWS CRITERIA TONIGHT... WINDS THAT ARE FROM THE SE AT 5-10 KTS AT THE SURFACE WILL VEER WITH HEIGHT TO SW AT 25-30 KTS AROUND 1500 FT AGL LATE TONIGHT... WHICH MAY CAUSE DIFFICULTY IN HANDLING SOME AIRCRAFT. THE THREAT OF PATCHY SHOWERS AND A STORM OR TWO WILL LINGER OVERNIGHT... THEN MORE ORGANIZED AND STRONGER STORMS ARE EXPECTED TO FORM TUE AFTERNOON... AS CIGS RISE TO MVFR TOWARD THE END OF THE TAF VALID PERIOD... WITH SURFACE WINDS BECOMING SOUTHERLY OR SOUTHWESTERLY AND INCREASING TO AROUND 15 KTS AS THE WARM FRONTAL ZONE SURGES NORTH OF CENTRAL NC. LOOKING BEYOND 18Z TUE... AVIATION INTERESTS SHOULD CLOSELY MONITOR THE LATEST CONDITIONS TUE AFTERNOON THROUGH WED EVENING... AS THERE IS A HEIGHTENED RISK OF STRONG TO SEVERE STORMS... ANY OF WHICH COULD PRODUCE DANGEROUS AVIATION WEATHER. OTHERWISE... EXPECT MAINLY MVFR CIGS THROUGH THE REST OF TUE AFTERNOON WITH GUSTY WINDS FROM THE SW AND A PEAK IN STORM COVERAGE INTO TUE EVENING. IFR/LIFR CIGS/VSBYS LIKELY TO RESUME AFTER 05Z WED... IMPROVING SLOWLY TO MVFR BY 16Z WED WITH ANOTHER PEAK IN STORM COVERAGE EXPECTED LATE WED AFTERNOON INTO THE EVENING. EXPECT A COLD FRONT TO SHIFT INTO CENTRAL NC AND WEAKEN EARLY THU... RESULTING IN PROBABLE VFR CONDITIONS AT GSO/INT AND MVFR/IFR HOLDING AT RDU/RWI/FAY THU. CONTINUED UNSETTLED FRI ESPECIALLY IN EASTERN TERMINALS WITH POSSIBLE MVFR CONDITIONS PERSISTING. VFR CONDITIONS EXPECTED SAT. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...WSS/SMITH SHORT TERM...WSS LONG TERM...BSD AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1159 AM EDT MON APR 28 2014 .SYNOPSIS... HIGH PRESSURE OFF THE SOUTHEAST UNITED STATES WILL CONTINUE TO BRING MILD SOUTHERLY WINDS TO THE REGION. SHOWERS AND THUNDERSTORMS WILL INCREASE IN COVERAGE TODAY THROUGH WEDNESDAY AS A TROUGH OF LOW PRESSURE APPROACHES FROM THE WEST. ANOTHER QUICK ROUND OF RAIN IS POSSIBLE LATE FRIDAY AND SATURDAY BEFORE CONDITIONS DRY OUT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1130 AM MONDAY...EXPECT LOCALIZED CONVECTION MAINLY ALONG LINGERING FRONT BASICALLY RUNNING ACROSS NORTH CAROLINA FROM WEST TO EAST ALONG NORTHERN TIER COUNTIES OF FORECAST AREA. MOIST SOUTHERLY FLOW OVER MOST OF CWA WITH TEMPS UP AROUND 80 AND DEWPOINTS IN THE MID 60S RUNNING UP AGAINST NORTHERLY WINDS WITH TEMPS CLOSER TO 70 AND DEWPOINTS IN THE 50S JUST NORTH OF LOCAL FORECAST AREA. THIS BOUNDARY WILL REMAIN THE FOCUS FOR CONVECTION THIS AFTERNOON BUT ALSO EXPECT CONVECTIVE DEVELOPMENT ALONG SEA BREEZE CONVERGENT BOUNDARY. THE SEA BREEZE WILL BE SLOW TO MOVE INLAND AS IT RUNS UP AGAINST A DECENT W-SW COMPONENT TO THE FLOW ABOVE THE SURFACE. RUC AND HRRR SHOW SHWRS POPPING BETWEEN 1 AND 2 PM. THE STEERING FLOW WILL PUSH ANY SHWRS/TSTMS THAT DEVELOP TOWARD THE COAST BUT THE MORE STABILIZED AIR BEHIND SEA BREEZE SHOULD KEEP THE IMMEDIATE COAST FREE OF STORMS. KEPT POPS VERY CLOSE TO PREVIOUS FORECAST WITH ONLY MINOR ADJUSTMENTS AND WILL UPDATE AS NEEDED ONCE CONVECTION FLARES. SHOULD SEE CLOUDS BLANKET MUCH OF THE AREA THROUGH THIS AFTERNOON AS CONVECTIVE DEBRIS CLOUDS WILL BE STEERED EAST AND HIGH CLOUDS WILL SPILL OVER THE MID TO UPPER RIDGE INTO LOCAL AREA THE STALLED BOUNDARY WILL BEGIN TO LIFT SLOWLY NORTH THROUGH THE DAY AND THIS MAY HELP TO SHIFT CONVECTION NORTH EVENTUALLY. WITH MID TO UPPER RIDGE OVER THE SOUTHEAST AND MORE IN THE WAY OF SUBSIDENCE THAN LIFT...DO NOT EXPECT MUCH IN THE WAY OF STRONG THUNDERSTORMS IN WARM AIR MASS TO THE SOUTH OF FRONT. ALSO EXPECT LOCALIZED CONVECTION TO SHUT DOWN AS HEATING OF THE DAY CUTS OFF AFTER SUNSET. THEREFORE WILL TAPER OFF POPS AFTER SUNSET LEAVING BEST CHC TO THE NORTH ALONG BOUNDARY. SHOULD BE A RELATIVELY QUIET NIGHT WITH ABUNDANT CLOUD COVER AND LOWS WELL ABOVE CLIMO...RUNNING IN THE MID 60S IN A WARM AND HUMID AIRMASS. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY...ALL EYES WILL BE ON THE SYSTEM NOW MOVING ACROSS THE CENTRAL U.S AS IT MAKES ITS MOVE ON THE EAST COAST. THE GFS...WHICH I HAVE BEEN LEANING TOWARD FOR A FEW CYCLES NOW REMAINS CONSISTENT WITH THE BEST LIFT AND MOISTURE COUPLING LATE WEDNESDAY AND INTO THE MORNING HOURS THURSDAY. I HAVE INCREASED POPS BASICALLY ACROSS THE BOARD MORE SO FOR THE LATER PERIODS. SPC CONTINUES TO HAVE THE AREA IN A SLIGHT RISK FOR BOTH DAYS. TEMPERATURE GUIDANCE IS IN GOOD AGREEMENT OUTSIDE OF DAYTIME HIGHS FOR WEDNESDAY WITH THE NAM/MET NUMBERS ONCE AGAIN COOLER. INHERITED BLEND WILL SUFFICE FOR NOW. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 3 AM MONDAY...THE FOCUS FOR THE EXTENDED BEGINS TO SHIFT FROM THE LONG ADVERTISED SYSTEM THAT IS CURRENTLY PLODDING ACROSS THE CENTRAL U.S TO A SECONDARY WAVE LATE IN THE PERIOD. THE LATEST MEDIUM RANGE GUIDANCE CONTINUES TO ADVERTISE A WET SCENARIO MAINLY ALONG THE COAST. I HAVE TWEAKED THE POPS FOR SATURDAY TO REPRESENT MORE OF A COASTAL SYSTEM ALTHOUGH THERE IS STILL PLENTY OF TIME FOR THIS TO CHANGE. POPS REMAIN IN THE FORECAST FOR THURSDAY AND FRIDAY MOSTLY VIA THE LOWER CONFIDENCE IN THE PROGRESS OF THE INITIAL SYSTEM. NO CHANGES TO THE TEMPERATURE FORECAST. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... AS OF 12..SOME LIGHT SHOWERS ARE MOVING THROUGH THE EASTERN PORTION OF THE REGION. PRECIP IS FALLING MAINLY OUT OF MID CLOUD. VFR THIS MORNING. MODELS ARE IN REASONABLY GOOD AGREEMENT IN INTRODUCING CONVECTION THIS AFTERNOON OVER THE NORTHERN HALF OF THE CWA...ASSOCIATED WITH A WARM FRONT AND RETURN MOISTURE FLOW. MOISTURE IS FAIRLY DEEP...AND IF THE CONVECTIVE TEMP IS REACHED...THERE SHOULD BE FAIRLY GOOD COVERAGE OF SHOWERS. MOST OF THE ACTIVITY WILL END THIS EVENING AS THE WARM FRONT WAVES NORTH. WITH THE SOUTHWESTERLY FLOW TONIGHT...IFR STRATUS IS A REASONABLE BET. EXTENDED OUTLOOK...ISOLATED AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS POSSIBLE THROUGH WEDNESDAY. OTHERWISE EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1130 AM MONDAY...QUIET MARINE CONDITIONS OVERALL THROUGH THIS AFTERNOON. HIGH PRESSURE REMAINS OVER THE AREA WITH LINGERING BOUNDARY LIFTING NORTH OF THE THE WATERS. GRADIENT REMAINS LIGHT WITH SOUTH TO SOUTHEAST FLOW REMAINING UNDER 10 KT THROUGH THE MORNING HOURS WITH SEAS 2 FT OR LESS. MAY SEE A FEW LINGERING SHOWERS MAKE IT OVER THE WATERS JUST ALONG NORTHERN PORTION OF LOCAL WATERS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY...A SOUTH TO OCCASIONALLY SOUTHEAST FLOW WILL PREVAIL THROUGH THE PERIOD. THE STRONGEST WINDS SHOULD OCCUR LATE WEDNESDAY WHEN A RANGE OF 20-25 KNOTS. FOR THE MOST PART A RANGE OF 15-20 KNOTS SHOULD BE FAIRLY PERSISTENT BEFORE THIS. SEAS WILL GRADUALLY BUILD FROM AN INITIAL RANGE OF 1-3 FEET TO 3-5 AND POSSIBLY 4-6 FEET BY THE END OF SECOND HALF OF THE PERIOD. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 3 AM MONDAY...THE MAIN ISSUE FOR THE MARINE COMMUNITY WILL BE THE TIMING OF THE WIND SHIFT WITH THE FRONT ASSOCIATED WITH THE MAIN INITIAL SYSTEM. THIS SHOULD OCCUR LATE THURSDAY/EARLY FRIDAY ALTHOUGH CONFIDENCE IS LOW DUE TO THE SLOW NATURE OF THIS SYSTEM. PRECEDING THIS...EXPECT A SOUTHWEST FLOW OF 15-20 KNOTS. FOR FRIDAY EXPECT A LIGHTER AND MORE VARIABLE FLOW. SIGNIFICANT SEAS WILL BE HOVERING AT OR JUST BELOW SMALL CRAFT CRITERIA THURSDAY 3-5 FEET DROPPING SLIGHTLY FRIDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RGZ SHORT TERM...SHK LONG TERM...SHK AVIATION...DL
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1229 PM CDT MON APR 28 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 344 AM CDT MON APR 28 2014 CURRENT WATER VAPOR IMAGERY SHOWS THE LOW IN THE MID LEVELS OF THE ATMOSPHERE SPINNING AWAY RIGHT IN THE MIDDLE OF NEBRASKA...WITH THE WELL ADVERTISED DRY SLOT ALOFT NOSING UP IN FRONT OF IT AND ENCOMPASSING MUCH OF OUR FORECAST AREA. THE MOST PRONOUNCED DRYING ALOFT IS ALONG THE I 29 CORRIDOR CURRENTLY. MODEL CONSENSUS IS GOOD IN PROGGING THE LOW SLOWLY EASTWARD TOWARD SOUTHEAST IA BY VERY LATE TONIGHT. THE SURFACE LOW FOLLOWS SUIT...AND IT LOOKS LIKE OUR ENTIRE FORECAST AREA WILL BE PLACED NORTH OF THE WARM FRONT THROUGH TODAY AND TONIGHT. THE BEST CHANCES FOR WIDESPREAD BENEFICIAL RAINFALL TODAY WILL BE BEHIND THE INVERTED TROUGH WHICH WILL BE CONFINED TO OUR FAR WESTERN ZONES APPROACHING CENTRAL SD. THE REST OF OUR AREA WILL SEE LESS NUMEROUS SHOWERS AND RAINFALL. BUT THERE IS ENOUGH ELEVATED INSTABILITY TO POP A THUNDERSTORM OR TWO ALMOST AT ANYTIME THROUGHOUT THE ENTIRE DAY...ESPECIALLY WHEN A MICROSCALE AREA OF WARM AIR ADVECTION DECIDES TO MOVE NORTHWARD WHICH THE MODELS CANNOT HANDLE VERY WELL ON THAT SCALE. INTERESTINGLY...BOTH THE GFS AND GEM PAINT A BROAD STRIPE OF DECENT QPF THIS AFTERNOON JUST NORTH OF THE WARM FRONT FROM SIOUX CITY TO STORM LAKE. IN ADDITION...THE PAST FEW RUNS OF THE HRRR ARE ALSO SHOWING THE POSSIBILITY OF DECENT CONVECTION IN THOSE AREAS AGAIN DUE TO THE PROXIMITY OF THE WARM FRONT JUST TO THE SOUTH. AT THIS TIME...IT LOOKS TOO STABLE FOR MUCH IN THE WAY OF SEVERE WEATHER...AND ALSO THE WIND SHEAR IS NOT REAL GREAT FROM SIOUX CITY TO STORM LAKE AS THE ENTIRE LOWEST 3 KILOMETERS HAS A WIND DIRECTION OUT OF THE EAST. ONE THING TO WATCH FOR HOWEVER IS IF A ROGUE SEVERE STORM WHICH BLOWS UP FURTHER TO THE SOUTHEAST NUDGES INTO THOSE AREAS BEFORE WEAKENING. TO THE NORTH...KEPT THE COVERAGE OF POPS IN THE SCATTERED CATEGORY THIS AFTERNOON ALONG THE I 29 CORRIDOR WHERE THE DRY SLOT ALOFT HAS THE MOST IMPACT. BUT OTHER AREAS MAY START TO FILL IN MORE WITH RAINFALL IN OUR FAR EAST AND INTO THE JAMES RIVER VALLEY FROM THE WEST AS MOISTURE PROGS SATURATE UP BETTER ALOFT. FEEL THERE IS NO NEED FOR A WIND ADVISORY TODAY AS SOUNDINGS ONLY MIX TO ABOUT 925-900MB AREA WIDE. WINDS IN THAT LAYER ARE STOUT... AVERAGING 30 TO 35 KNOTS...BUT USUALLY IT TAKES A LITTLE MORE THAN THAT TO WARRANT A WIND ADVISORY IN OUR AREA...CLOSER TO 40 KNOTS. HOWEVER TONIGHT ON THE BACK SIDE OF THE LOW...OUR FAR SOUTHWEST ZONES MAY GET CLOSE TO ADVISORY CRITERIA AFTER MIDNIGHT. MUCH OF OUR FORECAST AREA TONIGHT IS WELL PLACED IN THE UPPER LEFT QUADRANT OF THE LOW TRACK TO RECEIVE PRECIP. THERE IS EVEN SOME WEAK TROWALING IN THE 290-295K LAYER NUDGING INTO OUR AREA FROM THE EAST...AND SATURATION LOOKS TO BE IN NO SHORT SUPPLY FROM THE SURFACE TO AROUND 500MB. IN THE EVENING...AGAIN THE I 29 CORRIDOR MAY NOT RECEIVE MUCH RAIN...BUT PRECIP WILL FILL INTO THAT AREA OVERNIGHT. CONCERNING TEMPERATURES...WITH A FEW BREAKS POSSIBLE NEAR THE WARM FRONT... AREAS FROM YANKTON TO STORM LAKE AND SOUTHWARD SHOULD HIT 60 TO 65...PROGRESSIVELY COOLING OFF HEADING NORTHWARD. TONIGHT IS TRICKY...AND HAD TO ADD IN A SNOW MIX TO OUR NORTHERN AND WESTERN ZONES AS SURFACE TEMPERATURES COOL INTO THE MID 30S IN THOSE AREAS COUPLED WITH SUB ZERO 850MB TEMPERATURES. USED THE MODEL CONSENSUS 850MB -2 DEGREE C AND 925MB ZERO DEGREE C ISOTHERMS FOR THE RAIN AND SNOW LINES...COUPLED WITH TEMPERATURES NEAR 35. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 344 AM CDT MON APR 28 2014 TUESDAY WILL START FAIRLY RAINY OVER THE AREA...THOUGH AMOUNTS SHOULD BE LESS THAN A QUARTER INCH FOR THE DAY. DRYING WILL BEGIN FROM THE NORTH/NORTHEAST DURING THE AFTERNOON OVER THE WESTERN PART OF THE FORECAST AREA AS SOME SUBSIDENCE SPREADS IN FROM THE NORTH/ NORTHEAST BETWEEN LOBES ROTATING AROUND THE UPPER LOW TO THE EAST. FOR NOW WILL KEEP SOME VERY MINIMAL POPS IN THE WEST FOR TUESDAY NIGHT...WHILE ONLY SHAVING POPS TO LOW LIKELIES ALONG OUR EASTERN EDGE IN MN AND IA. FOR NOW AM GOING FOR ALL OF THIS PRECIPITATION TO BE LIGHT RAIN EXCEPT MAYBE SOME MODERATE RAIN LINGERING TUESDAY MORNING IN THE EAST...MAYBE WITH A BIT OF WET SNOW MIXED IN WEST AND NORTH EARLY MORNING BUT NO ACCUMULATION. FOR TUESDAY NIGHT...THOUGH TEMPERATURES ALOFT WILL BE MARGINAL FOR A LITTLE MIXED SNOW AGAIN... THERE MAY BE NO PRECIPITATION AT ALL IN THE WEST WHICH WOULD HAVE THE BETTER SHOT AT SOME SNOW. SURFACE AND NEAR SURFACE TEMPERATURES WILL LIKELY BE A BIT TOO WARM WITH THE LIGHTER NATURE OF PRECIPITATION...IF THERE IS ANY AROUND IN THE FIRST PLACE...AND DYNAMIC COOLING WILL BE NIL. TO THE EAST...THE DEEPER MOIST AIR SHOULD PRECLUDE ENOUGH COOLING TO GET SNOW TO THE SURFACE...AND EVEN THERE THE PRECIPITATION SHOULD BE PRETTY LIGHT. TEMPERATURES WILL NOT BE SHOWING A LOT OF SPREAD WITH 40S HIGHS AND 30S LOWS. IT WILL STILL BE WINDY TUESDAY BUT EXPECT WINDS WILL STAY BELOW ADVISORY CRITERIA. WEDNESDAY WILL BRING THE NEXT LOBE ROTATING OVER THE AREA AND A RESURGENCE OF LIGHT RAIN WEST/SOUTHWESTWARD AGAIN. TEMPERATURES AGAIN WILL CLIMB INTO THE 40S AND IT WILL BE WINDY AGAIN. IT COULD EVEN BE SLIGHTLY WINDIER THAN TUESDAY WITH THE LOBE PASSING OVER THE AREA. THURSDAY WILL BRING THE SYSTEM STARTING TO MOVE SLOWLY EAST OF THE AREA AND WILL KEEP LIGHT RAIN POPS IN THE CHANCE CATEGORY. WEDNESDAY NIGHT LOWS SHOULD BE IN THE 30S AGAIN...THOUGH IT MAY BE A DEGREE OR TWO LESS COOL THERE WITH MODELS HINTING AT VERY SLIGHT LOW LEVEL WARMING. WITH LESSER PRECIPITATION COVERAGE...THURSDAY DAY TEMPERATURES ARE EXPECTED TO BE A TAD LESS COOL...UPPER 40S TO LOWER 50S FOR HIGHS. THIS PROCESS WILL CONTINUE ON FRIDAY...REMEMBER THE SLOWNESS OF THIS SYSTEM...BUT POPS WILL BE PRETTY LOW WITH PRECIPITATION CONFINED MAINLY TO EAST OF FSD. 50 TO 55 LOOKS RIGHT FOR HIGHS FRIDAY. THE WEEKEND SHOULD BE A LITTLE WARMER YET...BUT STILL BELOW NORMAL...AHEAD OF A CANADIAN WAVE APPROACHING IN NORTHWEST FLOW BEHIND THE CURRENT SYSTEM. WILL GO WITH THE EXTENDED GUIDANCE GRIDS OF SHOWER CHANCE PEAKING ABOUT SATURDAY NIGHT. THIS SEEMS TO BE THE BEST PLAN FOR NOW ON EITHER THE GFS OR EC SOLUTION. THE EC HAS STRONGER RIDGING BETWEEN SYSTEMS THAN THE GFS AND WOULD BRING TEMPERATURES A LITTLE CLOSER TO NORMAL FOR THE WEEKEND...BUT THE LIGHT SHOWER THREAT IS STILL THERE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1228 CDT MON APR 28 2014 LINGERING SFC LOW WILL CONTINUE TO BRING IFR AND LOWER CONDITIONS TO HON...FSD AND SUX. WAVES OF SHRA WITH LOWER VIS WILL CONTINUE THRU THE TAF PD WITH CIGS JUPMING AROUND FROM 1KFT TO JUST BELOW 1KFT. WIND WILL PICK UP AGAIN WITH GUSTS AROUND 30KTS BY TUES MORNING. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...MJ LONG TERM... AVIATION...SALLY
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
514 PM CDT MON APR 28 2014 .MESOSCALE UPDATE... LATEST LAPS DATA CLEARLY SHOWS THAT THE BETTER INSTABILITY IS OVER OUR SOUTHERN AREAS WHICH IS WHERE THE TOR WATCH IS IN EFFECT. CAPE VALUES...SHOWALTERS ALL IN SUPPORT OF THE SUBSTANTIAL AMOUNTS OF INSTABILITY ACROSS THE SOUTH. CURRENT RADAR SHOWS THE STRONGEST ACTIVITY FROM DICKSON COUNTY SOUTHWARD THROUGH GILES COUNTY WITH AGAIN...THE STRONGEST ACTIVITY THE FURTHER SOUTH YOU GO. WE DO SEE A LINE OF THUNDERSTORMS ATTEMPTING TO DEVELOP BACK ACROSS WESTERN KY. HOWEVER...THERE IS A DEGREE OF INCREASING CAP STRENGTH ACROSS OUR NORTHERN AREAS. THUS...IT MAY HAVE A TOUGH TIME DEVELOPING INTO SOMETHING MORE SUBSTANTIAL. HRRR FURTHER CONCURS WITH THE IDEA OF NO REDEVELOPMENT TONIGHT TO THE WEST OF THE AFOREMENTIONED STRONGEST CONVECTION. BIGGEST POTENTIAL IMPACT OVER THE NEXT FEW HOURS WILL BE OVER OUR SOUTHERN AREAS WHERE THE POTENTIALLY TORNADIC CELLS COULD CLIP OUR FAR SOUTHERN COUNTIES AND EVENTUALLY OUR SOUTHERN PLATEAU. AS FOR THE FLOOD THREAT...THE FLASH FLOOD WATCH CONTINUES THROUGH TUESDAY EVENING. && .PREV DISCUSSION... /ISSUED 256 PM CDT MON APR 28 2014/ DISCUSSION... ..SIGNIFICANT SEVERE WEATHER THREAT STILL EXISTS OVER FAR SOUTHERN MIDDLE TN THROUGH TONIGHT... A STRONG LOW PRESSURE CENTER OVER EASTERN NEBRASKA WILL DRAG A COLD FRONT THROUGH THE REGION LATE TONIGHT...WITH ITS UPPER LOW LAGGING AND SPINNING ACROSS THE UPPER MIDWEST. STRONG DIVERGENCE ALOFT ON THE NOSE OF A 115-KT UPPER JET HAS LED TO AMPLE PRECIP ACROSS MIDDLE TN THIS MORNING THROUGH THE EARLY AFTERNOON HOURS. THIS ACTIVITY HAS LED TO 3-5 INCH RAINFALL AMOUNTS MAINLY WEST OF I-65 AND SOUTH OF I-40...WHERE RESIDUAL FLOODING AND FLASH FLOODING CONTINUE. A FLASH FLOOD WATCH CONTINUES FOR ALL OF MIDDLE TN AND WILL BE EXTENDED THROUGH TUESDAY AFTERNOON GIVEN THE RIVER FLOODING THREAT FROM ADDITIONAL RAINS FROM THIS EVENING THROUGH THE OVERNIGHT HOURS. WILL ISSUE THE UPDATED FLASH FLOOD WATCH SOON. MORE INTERESTINGLY...THE MORNING CONVECTION DROPPED AN OUTFLOW BOUNDARY ACROSS FAR SOUTHERN MIDDLE TN...WHERE POINTS NORTH OF THAT BOUNDARY REMAIN IN THE COLD POOL REGION...AND POINTS ALONG AND SOUTH OF THIS BOUNDARY REMAIN VERY UNSTABLE. THIS BOUNDARY EVEN CURLS BACK TO THE WEST A BIT OVER OUR FAR EASTERN CWA. WITH SFC CAPE VALUES AROUND 2000 J/KG AND AMPLE LOW-LEVEL SHEAR AS WELL AS DEEP LAYER SHEAR SOUTH OF THIS BOUNDARY...SPC ISSUED A PDS TORNADO WATCH FOR MAINLY OUR SOUTHERN TWO TIERS OF COUNTIES UNTIL 9PM. ANYTHING CLOSEST TO THE HUNTSVILLE COUNTY WARNING AREA WILL HAVE THE BEST CHANCE SEEING A SIGNIFICANT THREAT FOR SUPERCELLS...WHICH MEANS A TORNADO...HAIL AND DAMAGING WIND THREAT. TORNADOES ON THE GROUND HAVE BEEN REPORTED IN NORTHERN MS ALREADY...MOVING NE. IT WILL BE A CLOSE CALL FOR FAR SOUTHERN MIDDLE TN. FYI...WE WILL ADD GRUNDY COUNTY TO THE WATCH AS WELL. ALSO...NORTH OF THIS BOUNDARY...SEVERE STORMS WILL STILL BE POSSIBLE BUT HAIL WILL BE THE ONLY SEVERE WEATHER THREAT FOR STORMS IN THE COLD POOL. SUPERCELLS OVER MS SHOULD COAGULATE INTO A LARGE AREA OF CONVECTION AND THIS SHOULD SPREAD NORTHWARD WITH TIME. OVERNIGHT...THIS WILL MOVE EAST THROUGH MIDDLE TN...AND POPS COULD TAPER FROM WEST TO EAST TOWARDS TUESDAY MORNING. AN ADDITIONAL 1-2 INCHES OF RAINFALL WILL BE POSSIBLE THROUGH TONIGHT...WITH LOWS AROUND 60. ON TUESDAY...THE SFC LOW SHOULD ROTATE A LITTLE FURTHER EAST AND ANOTHER LOBE OF ENERGY FROM THE UPPER LOW WILL SWING THROUGH THE REGION. WOULD THINK ANOTHER ROUND OF AFTERNOON-EVENING CONVECTION SHOULD EASILY BE GENERATED...THIS TIME WITH MORE SHEAR ACROSS MIDDLE TN...MORE SUNSHINE THROUGH THE MORNING HOURS...AND COLDER AIR ALOFT WITH THE UPPER LOW GETTING CLOSER. WOULD EXPECT ANOTHER ROUND OF SEVERE WEATHER TOMORROW AFTERNOON AND EVENING...WITH LARGE HAIL AND DAMAGING WINDS THE BEST THREAT. EVEN AN ISOLATED TORNADO OR TWO CAN NOT BE RULED OUT. FINALLY THE SYSTEM WILL MOSTLY PULL OUT ON WEDNESDAY...WITH PERHAPS SOME LINGERING SHOWERS INTO WEDNESDAY EVENING. TEMPS WILL COOL OFF INTO THE 70S ON WEDNESDAY...AND EVEN COOLER THURSDAY- SATURDAY IN THE 60S. CONDITIONS SHOULD MOSTLY BE DRY THURSDAY ON...WITH TEMPS WARMING BACK UP TO NEAR 80 SUNDAY AND MONDAY. && .OHX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR TNZ005>011-023>034- 056>066-075-077>080-093>095. && $$ 21
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1243 PM CDT MON APR 28 2014 .DISCUSSION...NOTE AVIATION DISCUSSION BELOW. && .AVIATION...VFR CONDITIONS ARE EXPECTED DURING THE TAF PERIOD EXCEPT FOR MVFR/IFR CONDITIONS GENERALLY EAST OF U.S. ROUTE 281 OWING TO MIST/FOG DRG THE 07-13Z TUESDAY PERIOD. MODERATE NORTH WIND THIS AFTN BECOMING LIGHT SOUTH/VARIABLE OVERNIGHT THEN MODERATE NORTH WIND TUESDAY BY MID MORNING IN RESPONSE TO A COLD FRONT. && .PREV DISCUSSION... /ISSUED 635 AM CDT MON APR 28 2014/ DISCUSSION...SEE 12Z AVIATION DISCUSSION. AVIATION...LOW CIGS/VSBYS RAPIDLY LIFTING AS WINDS HAVE SHIFTED. WILL LIKELY JUST HAVE SOME TEMPO CONDITIONS ENDING BY NO LATER THAN 14Z EASTERN TERMINALS. SHOULD MAINLY HAVE N-NW WINDS ESPECIALLY BY 14Z WITH MAINLY CLEAR SKIES. SEA-BREEZE COMES IN AGAIN LATE THIS AFTERNOON AND SHIFT WINDS SOUTHERLY STARTING ABOUT 20Z AT KCRP AND SPREADING WESTWARD. WINDS DIMINISH TONIGHT AND MAINLY BECOME LIGHT AND VARIABLE OVERNIGHT. COULD HAVE SOME GROUND FOG KCRP AND KVCT TOWARD END OF TAF PERIOD AS LIGHT WINDS AND CLEAR SKIES CREATE FOG. PREV DISCUSSION... /ISSUED 326 AM CDT MON APR 28 2014/ SHORT TERM (TODAY THROUGH TUESDAY)...WARM AND DRY TODAY AND TUESDAY TOO (MOST AREAS)...AS COLD AIR IS EXPECTED TO LAG BEHIND THE FRONTAL BOUNDARY ON TUESDAY. LOOKS LIKE ANOTHER HOT DAY...BUT NOT AS HOT AS YESTERDAY AT LEAST OUT TO THE WEST AS BOUNDARY LAYER TEMPERATURES ARE PROGGED TO BE SEVERAL DEGREES COOLER (SO IF THAT HAPPENS IT SHOULD BE COOLER). 4KM RUC IS SHOWING TEMPERATURES TOPPING 100 DEGREE BARRIER OVER THE SOUTHERN AREAS...AND WILL GO 101/102 OVER THE SOUTHWESTERN AREAS. OTHERWISE...MORNING LOW CLOUDS OVER THE EAST WILL QUICKLY LIFT AND SHOULD SEE LOTS OF SUN WITH NORTHWEST WINDS AS DRY LINE MOVES FARTHER EAST THAN YESTERDAY. LOW LEVEL MOISTURE IS TOO SCOURED OUT FOR ANY MENTION OF RAIN (EVEN OFFSHORE) SO HAVE REMOVED (4KM MODELS KEEP THINGS DRY TOO). FOR TONIGHT...ONLY NAM IS BRINGING COOLER AIR MUCH FASTER THAN GFS/ECMWF (ALTHOUGH CANADIAN IS COOL TOO...AS USUAL). AM GOING TO PREFER TO GO MORE ON THE WARM SIDE TONIGHT ALTHOUGH IF WINDS ARE TOO LIGHT AND SURFACE MOISTURE IS TOO LOW...WE COULD REALLY BOTTOM OUT (GIVEN WARM DAY EXPECTED TODAY WILL PREFER TO STAY ON THE WARM SIDE THOUGH). COOLER AGAIN ON TUESDAY BUT STILL WARMER THAN NORMAL WITH COLD AIR LAGGING ON FRONT. MAY SEE A FEW 80S IN THE VICTORIA AREA. MOISTURE AGAIN TOO LIMITED FOR PRECIPITATION. MARINE (TODAY THROUGH TUESDAY)...HAVE EXTENDED THE SCA TIL 4 AM FOR THE BAYS/WATERWAYS...AND LONGER FOR THE GULF WATERS. MAY NEED TO EXTEND AGAIN AT THE LAST MINUTE IF WINDS STAY UP AGAIN. WINDS HAVE STAYED UP LONGER THAN EXPECTED WITH GUSTS OVER 30 KNOTS AT KNGP. 4KM RUC HAS WINDS CRANKING TIL 12Z OR SO...BUT THIS IS NORMALLY ON THE HIGH SIDE (BUT STILL DOING BETTER THAN NAM12 OR OTHER MODELS). WINDS DO DECREASE BY SUNRISE...BUT SEAS STAY UP. THUS...THE GULF WATER SCA WILL MAINLY BE FOR HIGH SEAS MONDAY...WITH SCA CONDITIONS ENDING AROUND NOON. VISIBILITIES OVER THE MARINE AREAS ARE BETWEEN 1 AND 3 MILES...AND THAT SHOULD CLEAR UP LATER THIS MORNING. MORE FOG TONIGHT BUT THAT SHOULD BE OVER THE OFFSHORE WATERS (IF THAT)...AS DRIER AIR DOES GET INTO THE NEARSHORE WATERS. COULD NOT RULE OUT A ROGUE SHOWER NEAR MATAGORDA ISLAND BUT THAT WILL BE VERY BRIEF AND UNLIKELY TO HAPPEN (SO NOT IN FORECAST). FIRE WEATHER (TODAY THROUGH TUESDAY)...FIRE WEATHER PROCEDURE IS SHOWING ELEVATED CONDITIONS/ISOLATED CRITICAL OVER MUCH OF THE AREA ON TUESDAY. FUEL DRYNESS FORECAST MAP IS SHOWING MOST AREAS IN NORMAL MOISTURE..WITH ONLY A PART OF THE NORTHERN COASTAL BEND (LIVE OAK AND PORTIONS OF BEE AND MCMULLEN COUNTIES) IN DRY FUELS. SINCE THESE COUNTIES ARE FORECAST TO BE IN ELEVATED CONDITIONS ON TUESDAY...NO NEED FOR FIRE WEATHER WATCH OR RED FLAG WARNING. DAY SHIFT OR NEXT MID SHIFT CAN RE-EVALUATE...ESPECIALLY IF FUEL DRYNESS MAP CHANGES THE NEXT DAY. LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...PERIOD BEGINS WITH COOLER TEMPERATURES AND DRY CONDITION IN WAKE OF TUESDAY/S/S FROPA. BROAD LONGWAVE TROUGH CENTERED OVER THE FAR NORTH CENTRAL STATES WILL KEEP FAIRLY ZONAL FLOW OVER SOUTH TEXAS THROUGH THURSDAY. TROUGH WILL FINALLY SWING OVER THE REGION THURSDAY NIGHT INTO FRIDAY. ECMWF CONTINUES TO BE THE WETTER SOLUTION WITH THIS PASSING WHILE THE GFS/NAM STAY MOSTLY DRY OVERLAND. WHILE THERE IS THE UPPER LEVEL SUPPORT FOR PERHAPS SOME SPRINKLES AND RAIN TO DEVELOP THERE IS AN OVERALL LACK OF SUFFICIENT MOISTURE OVER MOST OF THE REGION EXCEPT IN THE OVER THE OFFSHORE WATERS THURSDAY NIGHT INTO FRIDAY MORNING. KEPT THE 20 POPS MENTION OVER THE OFFSHORE WATERS FOR NOW...BUT EVEN THIS MAY BE GOING TOO HIGH. OTHERWISE EXPECT A CONTINUED DRY FORECAST. TEMPERATURES WILL BE NICELY COOLER (BELOW AVERAGE) THROUGH THE END OF THE WEEK BEFORE RETURNING TO NORMAL ON BY THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 66 93 61 80 59 / 0 10 10 10 10 VICTORIA 63 88 55 81 51 / 0 10 10 10 10 LAREDO 69 98 62 86 60 / 0 10 10 10 10 ALICE 64 96 57 83 54 / 0 10 10 10 10 ROCKPORT 67 89 62 79 61 / 0 10 10 10 10 COTULLA 63 92 54 83 54 / 0 0 10 10 10 KINGSVILLE 65 97 60 81 57 / 0 10 10 10 10 NAVY CORPUS 67 87 65 79 65 / 0 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ WC/87...AVIATION
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1212 PM CDT MON APR 28 2014 .AVIATION... MUCH DRIER AIR IS FILTERING INTO SOUTHEAST TEXAS RESULTING IN MOSTLY CLEAR SKIES. SOME LOWER CLOUDS ARE EAST OF THE TAF SITES AND ALONG THE COAST WHERE THE DEEPEST MOISTURE EXISTS...AND THAT IS WHERE THE HRRR CONTINUES TO WANT TO DEVELOP SOME SHOWERS THIS AFTERNOON. WILL MONITOR CLOSELY...BUT AT THIS TIME NOT CONFIDENT ENOUGH TO INCLUDE ANY MENTION IN THE 18Z TAF PACKAGE. THERE IS A CHANCE THAT ENOUGH MOISTURE COULD BE PRESENT OVERNIGHT FOR POSSIBLE LOW CLOUD AND FOG DEVELOPMENT...FROM ROUGHLY CXO SOUTHWARD TO THE COAST. FOR NOW...WILL ONLY MENTION THIS IN THE CXO AND LBX TAFS WHERE MODELS ARE HITTING IT THE HARDEST. STRONG COLD FRONT WILL MOVE ACROSS SOUTHEAST TEXAS TOMORROW MORNING AND OFF THE COAST LATE IN THE MORNING OR EARLY IN THE AFTERNOON WITH GUSTY NORTH TO NORTHWEST WINDS BEHIND THE BOUNDARY. NO SHOWERS OR THUNDERTORMS ARE EXPECTED WITH THE FRONT. 42 && .PREV DISCUSSION... /ISSUED 1058 AM CDT MON APR 28 2014/ DISCUSSION... ADDED CLIMATE SECTION. CLIMATE... HIGH TEMPERATURES TODAY WILL LIKELY REACH 90 DEGREES. THE LAST TIME THE CITY OF HOUSTON (KIAH) REACH 90 DEGREES WAS OCTOBER 5TH OF LAST YEAR (93). THE LAST TIME COLLEGE STATION (CLL) REACHED 90 DEGREES WAS OCTOBER 1ST OF LAST YEAR (91). HERE ARE THE RECORDS FOR THE THREE FIRST ORDER CLIMATE SITES FOR TODAY WITH THEIR FORECASTED HIGHS TO THE FAR RIGHT: CLL (COLLEGE STATION) : 94 (1987) || 91 IAH (CITY OF HOUSTON) : 95 (1987) || 92 GLS (CITY OF GALVESTON):87 (1987) || 84 PREV DISCUSSION... /ISSUED 1038 AM CDT MON APR 28 2014/ UPDATE... SEE DISCUSSION FOR MORNING UPDATE. DISCUSSION... PRECIP HAS COME TO AN END ACROSS MOST OF THE AREA THIS MORNING AS DRIER AIR WORKS ITS WAY IN FROM THE WEST. HRRR SHOWS A CELL OR TWO TRYING TO DEVELOP IN CHAMBERS COUNTY AS THE DRY LINE STALLS NEAR THE COAST THIS AFTERNOON. THE TORNADO WATCH FOR THE AREA WILL BE ALLOWED TO CONTINUE UNTIL 17Z. BEHIND THE DRY LINE LIGHT NORTHWEST WINDS... LITTLE CLOUD COVER AND DRY AIR WILL HELP THE AREA TO QUICKLY HEAT UP. CURRENT AMDAR SOUNDING FOR HOUSTON SUPPORTS TEMPERATURES IN THE LOWER 90S. MOST OF THE AREA IS ALREADY AT OR SLIGHTLY ABOVE 80. 90 DEGREES LOOKS POSSIBLE FOR MOST SITES ACROSS THE AREA (MINUS NORTHEAST COUNTIES AND AT THE COAST). NUDGED MAX TEMPERATURE GRID UP SLIGHTLY FOR THIS AFTERNOON. ALSO TRIMMED POPS BACK AS THE CHANCE FOR CONVECTION APPEARS TO BE COMING TO AN END. NO OTHER CHANGES TO GRIDS AT THIS TIME. 23 PREV DISCUSSION... /ISSUED 421 AM CDT MON APR 28 2014/ DISCUSSION... BKN LINE OF TSTMS HAS DEVELOPED SEVERAL MILES AHEAD OF THE SFC TROF EXTENDING FROM NORTHEAST TEXAS AND INTO NORTHERN PARTS OF SE TX. NO REPORTS OF SEVERE WX IN OUR CWA JUST YET BUT WOULD BE SURPRISED IF NO HAIL IS EVENTUALLY REPORTED FROM HOUSTON COUNTY W/ THOSE STORMS. THINK MAJORITY OF THESE WILL REMAIN ELEVATED SO HAIL WILL BE PRIMARY THREAT. HRRR MODEL HAS BEEN DOING A GOOD JOB IN THE PAST 24 HOURS AND HAS CONTINUED DOING WELL WITH CURRENT TRENDS. IT SHOWS THIS PRECIPITATION MAKING ITS WAY SEWD TOWARD THE UPPER TX COAST IN THE NEXT 6 HOURS SO HAVE BUMPED POPS UP ACROSS A GOOD PART OF THE AREA. SFC TROF WILL MAKE IT ALMOST TO THE COAST BY LATE MORNING ENDING PRECIP CHANCES AND BRINGING A DRY AIRMASS INTO MOST OF THE AREA. THIS DRY AIRMASS AND SUNSHINE SHOULD ALLOW FOR A RAPID WARM UP ACROSS THE AREA THIS AFTN. SFC TROF MOVES BACK NORTH LATE TONIGHT AND BECOME OVERTAKEN BY THE PRIMARY COLD FRONT THAT WILL PUSH ACROSS THE AREA DURING THE DAY TUE. CURRENT GUIDANCE COMING IN A TOUCH COOLER THAN EARLIER FCSTS SO NUDGED HIGHS/LOWS DOWN A BIT FOR THE NEXT SEVERAL DAYS. THRU LATE WEEK WE SHOULD STILL BE IN A WSW FLOW ALOFT UNDER BROAD UPPER TROF SITUATED ACROSS CNTL PARTS OF THE COUNTRY. MAY SEE PERIODS OF HIGH CLOUDINESS BUT MEAGER LLVL MOISTURE LEVELS SHOULD KEEP THINGS MOSTLY DRY. SHOULD TRANSITION TO A DRY NW FLOW LATE IN THE WEEK AND EARLY WEEKEND AS UPPER TROF MOVES EWD. OTHERWISE...LOOKS QUITE DRY THRU THE 1ST WEEK OF MAY. 47 MARINE... WILL EXTEND THE CURRENT ADVISORIES OVER THE COASTAL WATERS/CAUTION FLAGS ON THE BAYS INTO THE MID MORNING HRS BASED ON CURRENT TRENDS. GRADIENT STILL EXPECTED TO WEAKEN BY THE AFTN WITH THE APPROACH OF THE PACIFIC FRONT FROM THE WEST. AS THIS BOUNDARY STALLS ALONG THE COASTLINE...WINDS SHOULD REMAIN OUT OF THE SW/S THROUGH THE DAY/TO- NIGHT. THE MAIN PUSH OF STRONG NORTH WINDS STILL FCST FOR TUE AFTN WITH THE CANADIAN COLD FRONT. BEHIND THIS FRONT...CAUTION/ADVISORY FLAGS WILL BE LIKELY FROM TUE NIGHT INTO WEDS NIGHT. THIS OFFSHORE FLOW COULD EXTEND THROUGH THE END OF THE WEEK. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 91 59 82 51 75 / 10 10 10 0 0 HOUSTON (IAH) 92 62 86 55 78 / 20 10 10 0 0 GALVESTON (GLS) 84 71 84 62 77 / 20 10 20 0 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 2 PM CDT THIS AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...23 AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT MON APR 28 2014 .SHORT TERM...(TONIGHT AND TUESDAY) ISSUED AT 322 PM CDT MON APR 28 2014 WATCHING THE FRONTAL STRUCTURE TO THE SOUTH CLOSELY AND INSTABILITY TO SEE IF CHANGES IN SEVERE WEATHER FORECASTS NEED TO BE CHANGED...AND TRYING TO BUILD IN BETTER TIMING OVERNIGHT FOR NEXT WAVE OF RAIN. WINDS STILL STRONG...BUT THOSE SHOULD BE DECREASING AFTER MIDNIGHT. GOES WATER VAPOR IMAGERY SHOWING THE MAIN LONG WAVE ANCHORED NEAR CENTRAL NEB WITH A NUMBER OF SHORTWAVE TROUGHS WITHIN THE LARGE TROUGH AREA MOVING NORTH THROUGH IA/MO. IT APPEARS ONE SMALLER CURL CAN BE SEEN IN NERN MO HEADING NORTH. THE AREA HAS BEEN UNDER 300-500MB QG CONVERGENCE LIFT AHEAD OF THIS BROAD TROUGH SPOKE ROTATING NORTHWARD...WITH ISENTROPIC LIFT IN THE LOW-LEVELS NORTH OF THE WARM FRONT...AND THE RAIN TODAY NOW LIFTING NORTH. THE WARM FRONT CONTINUES TO HOLD NEARLY IN PLACE SOUTH OF I-80 AT 19Z. MEANWHILE THE COLD FRONT FROM OMAHA TO CENTRAL MO WAS CLEAR ON VISIBLE IMAGERY AND CONVECTING NOW...AND OVER THE PAST HOURS THE OCCLUSION AND TRIPLE POINT ARE RIPPING EAST...NOW NEAR KDSM. THE STORMS ON THIS OCCLUSION AND COLD FRONT WILL ROTATE NORTHWARD TONIGHT INTO THE FORECAST AREA. 12Z RAOB PRECIPITABLE WATER VALUES ARE NOT AS HIGH AS THE MORNING MODEL INITIALIZATIONS...WITH THE 28.12Z GFS/NAM SHOWING A 1-1.25 INCH PLUME FROM NRN IL INTO SERN MN. KMPX WAS ONLY 0.62 AT 12Z FROM THE RAOB. 1500 FT WINDS OF AREA 88D VAD WINDS ARE STILL IN THE 40-50KT RANGE FROM KMKX- KMPX...EXPLAINING THE CONTINUED WIND GUSTS IN THE 30S MPH. AS THE LATER AFTERNOON PROGRESSES...THE COLD FRONT WILL CONTINUE THE OCCLUSION PROGRESSES SEWRD TOWARD IL. BY EVENING THE TRIPLE POINT SHOULD BE WELL INTO IL WITH A BAND OF TSRA ALONG AND NORTH OF THE OCCLUSION HEADING NORTH TOWARD THE AREA. THE OCCLUSION BOUNDARY STAYS NEAR I-80 IN THE LATEST HRRR RUNS...WITH THE ELEVATED TSRA AND PRECIPITATION BAND ROTATING INTO MN/WI. THE MOST UNSTABLE CAPE ANALYSIS SHOWS 250 J/KG IN THE SOUTHERN FORECAST AREA AT 20Z...WITH ABOUT 500 J/KG APPROACHING THE SOUTHERN FORECAST AREA. AS WITH DAYS PAST...AS THIS TSRA BAND APPROACHES NERN IA AND SWRN WI AFTER 5 PM...CONVECTIVE ACTIVITY IS EXPECTED TO DEGRADE. SOME SMALL HAIL IS POSSIBLE FROM THE STORMS IN THE SOUTHERN FORECAST AREA...BUT THEN A TRANSITION TO A MORE STRATIFORM RAIN REGION WILL OCCUR. THERE IS EXCELLENT AGREEMENT ON THE MODEL GUIDANCE ON THE BAND ROTATING NORTH THROUGH THE AREA OVERNIGHT. HAVE FORECAST AMOUNTS OF LESS THAN ONE-HALF OF AN INCH. WITH MODELS TOO HIGH ON PRECIPITABLE WATER...HAVE DISCOUNTED HEAVIER RAINFALL TOTALS SUCH AS THE 28.12Z. THE BAND WILL ROTATE INTO THE NORTHERN FORECAST AREA TUESDAY MORNING AND SLOW ITS PROGRESS AS THE SURFACE LOW SHIFTS TOWARD ROCKFORD IL. THIS WILL PROVIDE A QUICK WARM UP TO THE BOUNDARY LAYER AND SOME INSTABILITY ACROSS SOUTHWEST WI FOR A TIME TUESDAY. HAVE ADDED SOME THUNDER THERE BUT DO NOT EXPECT MORE THAN PEA SIZED HAIL WITH 250 J/KG OF CAPE OR SO. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 322 PM MON APR 28 2014 TUESDAY NIGHT THROUGH THURSDAY NIGHT THE AREA WILL BE RIGHT UNDER THE OCCLUDED DEEP LOW WITH SPOKES OF ENERGY CONTINUING TO ROTATE THROUGH THE AREA. THE MODEL GUIDANCE AGREES ON THE BIG PICTURE BUT THE DETAILS OF TIMING ON RAIN CHANCES ARE ALL OVER THE PLACE AMONG ALL THE AVAILABLE MODELS. HAVE KEPT THIS PERIOD SHOWERY WITH MUCH LIGHTER WINDS THAN WE HAVE SEEN. FAIRLY SATURATED CONDITIONS AND SHORTWAVES THAT WILL BE ROTATING THROUGH THE LONG WAVE WILL BRING MORE ORGANIZED SHOWER AREAS I AM SURE. AT THIS POINT...RAISED RAIN CHANCES THROUGH THIS PERIOD TO AT LEAST 60 PERCENT WITH MORE DETAIL TO BE ADDED AS WE GET CLOSER TO THOSE DAYS AND CAN IDENTIFY WHERE TO IMPROVE THE FORECAST. COOL AND CLOUDY WITH LIGHT RAINFALL /LESS THAN ONE TENTH PER 12 HOURS/ FOR MOST EVERYWHERE. FRIDAY THROUGH MONDAY A BELOW NORMAL TEMPERATURE PERIOD. LONG WAVE TROUGH AND SHORTWAVE ACTIVITY SPOKING AROUND THE LOW WILL MAKE FOR DETAILS IN THIS PERIOD DIFFICULT. BY FRIDAY IT WOULD APPEAR THE MODEL CONSENSUS SUGGEST THE AREA INTO NORTHWEST FLOW WHICH CAUSES ITS OWN ISSUES FOR TIMING OF SHOWERS WITH SHORTWAVE TROUGHS. HEIGHTS RISE MORE OVER THE GREAT LAKES ON FRIDAY NIGHT AND SATURDAY AS ENERGY CRASHES ONTO THE WEST COAST. THIS ENERGY THEN EJECTS INTO THE PLAINS BY LATER SATURDAY WITH CYCLOGENESIS AND SOUTHERLY RETURN FLOW ACTIVATING ON THE FRONT TO THE SOUTHWEST. FOR A 150 HOUR FORECAST...THERE IS PRETTY GOOD AGREEMENT WITH THE LATEST TWO RUNS OF THE ECMWF/GFS MODELS THAT SHOWERS/RAIN WILL SPREAD ACROSS THE REGION SUNDAY WITH THE NORMAL WARM FRONTAL LIFT SIGNALS OF ISENTROPIC LIFT...MOISTURE TRANSPORT CONVERGENCE. WHILE PLACEMENT IS VARIED...THE GENERAL AGREEMENT ADDS TO CONFIDENCE. BOTTOM LINE IS SATURDAY LOOKS LIKE THE DRIER DAY STILL BUT CONFIDENCE IS SOMEWHAT LOW WITH NORTHWEST FLOW VERY DIFFICULT TO FORECAST 5 DAYS OUT. TEMPERATURES DONT LOOK TO REBOUND MUCH UNTIL SATURDAY...BUT CLOUDS MAKE ALL THE DIFFERENCE THIS TIME OF YEAR. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 600 PM CDT MON APR 28 2014 CLOSED...VERTICALLY STACKED LOW WILL BE THE WEATHER MAKER OVER THE NEXT FEW DAYS. THIS WILL KEEP KRST/KLSE UNDER A PROLONGED PERIOD OF MVFR/IFR CIGS...WITH BOUTS OF MVFR VSBYS DURING -SHRA/RA. WINDS WILL STAY STRONG TONIGHT...BUT AS THE LOW INCHES NORTHWARD TUE...EXPECT SOME SLACKENING IN THE PRESSURE GRADIENT...AND A REDUCTION IN WIND SPEEDS. DIRECTION WILL BECOME MORE NORTHERLY TUE...THEN SHIFTING NORTHWEST LATE TUE NIGHT. LLWS REMAINS A CONCERN AT KLSE WITH AROUND 50 KTS AT 2 KFT. WILL CONTINUE A MENTION IN FORECAST INTO THE OVERNIGHT HOURS. && .HYDROLOGY... ISSUED AT 322 PM CDT MON APR 28 2014 AFTER RECEIVING LESS RAIN OVERNIGHT THAN ORIGINALLY THOUGHT...THE RIVER SITUATION SEEMS LIKE IT WILL BEHAVE FOR THIS STORM. WE ARE EXPECTING ABOUT 0.50 TO 0.75 INCHES OF RAIN TONIGHT AND TUESDAY FOR MOST AREAS WHICH WILL MEAN BANKFULL RIVER RISES FOR MOST RIVERS...AND A LOW FLOODING THREAT. THE KICKAPOO MAY BE THE CLOSEST RIVER TO FLOODING. MAYBE THE MAIN STORY IS THE MISSISSIPPI RIVER THAT WILL SWALLOW ALL THE INCOMING TRIBUTARY WATER AND CONTINUE TO RISE ALL NEXT WEEK. FROM WINONA MN SOUTH...IT APPEARS THE MISSISSIPPI RIVER WILL BE APPROACHING MINOR FLOOD LEVELS BY LATER THIS WEEK...WITH FLOODING LIKELY FURTHER NORTH. THE FLOOD WATCH HAS BEEN ISSUED FOR THE WINONA AND SOUTH FLOODING THREAT. AFTER TONIGHT...RAINFALL AMOUNTS WILL TURN MORE SHOWERY AS THE GULF MOISTURE PLUME IS SHUNTED EAST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR WIZ041-053-054-061. MN...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR MNZ088-096. IA...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR IAZ011-030. && SHORT TERM...BAUMGARDT LONG TERM....BAUMGARDT AVIATION.....RIECK HYDROLOGY....BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
323 PM CDT MON APR 28 2014 .SHORT TERM...(TONIGHT AND TUESDAY) ISSUED AT 322 PM CDT MON APR 28 2014 WATCHING THE FRONTAL STRUCTURE TO THE SOUTH CLOSELY AND INSTABILITY TO SEE IF CHANGES IN SEVERE WEATHER FORECASTS NEED TO BE CHANGED...AND TRYING TO BUILD IN BETTER TIMING OVERNIGHT FOR NEXT WAVE OF RAIN. WINDS STILL STRONG...BUT THOSE SHOULD BE DECREASING AFTER MIDNIGHT. GOES WATER VAPOR IMAGERY SHOWING THE MAIN LONG WAVE ANCHORED NEAR CENTRAL NEB WITH A NUMBER OF SHORTWAVE TROUGHS WITHIN THE LARGE TROUGH AREA MOVING NORTH THROUGH IA/MO. IT APPEARS ONE SMALLER CURL CAN BE SEEN IN NERN MO HEADING NORTH. THE AREA HAS BEEN UNDER 300-500MB QG CONVERGENCE LIFT AHEAD OF THIS BROAD TROUGH SPOKE ROTATING NORTHWARD...WITH ISENTROPIC LIFT IN THE LOW-LEVELS NORTH OF THE WARM FRONT...AND THE RAIN TODAY NOW LIFTING NORTH. THE WARM FRONT CONTINUES TO HOLD NEARLY IN PLACE SOUTH OF I-80 AT 19Z. MEANWHILE THE COLD FRONT FROM OMAHA TO CENTRAL MO WAS CLEAR ON VISIBLE IMAGERY AND CONVECTING NOW...AND OVER THE PAST HOURS THE OCCLUSION AND TRIPLE POINT ARE RIPPING EAST...NOW NEAR KDSM. THE STORMS ON THIS OCCLUSION AND COLD FRONT WILL ROTATE NORTHWARD TONIGHT INTO THE FORECAST AREA. 12Z RAOB PRECIPITABLE WATER VALUES ARE NOT AS HIGH AS THE MORNING MODEL INITIALIZATIONS...WITH THE 28.12Z GFS/NAM SHOWING A 1-1.25 INCH PLUME FROM NRN IL INTO SERN MN. KMPX WAS ONLY 0.62 AT 12Z FROM THE RAOB. 1500 FT WINDS OF AREA 88D VAD WINDS ARE STILL IN THE 40-50KT RANGE FROM KMKX- KMPX...EXPLAINING THE CONTINUED WIND GUSTS IN THE 30S MPH. AS THE LATER AFTERNOON PROGRESSES...THE COLD FRONT WILL CONTINUE THE OCCLUSION PROGRESSES SEWRD TOWARD IL. BY EVENING THE TRIPLE POINT SHOULD BE WELL INTO IL WITH A BAND OF TSRA ALONG AND NORTH OF THE OCCLUSION HEADING NORTH TOWARD THE AREA. THE OCCLUSION BOUNDARY STAYS NEAR I-80 IN THE LATEST HRRR RUNS...WITH THE ELEVATED TSRA AND PRECIPITATION BAND ROTATING INTO MN/WI. THE MOST UNSTABLE CAPE ANALYSIS SHOWS 250 J/KG IN THE SOUTHERN FORECAST AREA AT 20Z...WITH ABOUT 500 J/KG APPROACHING THE SOUTHERN FORECAST AREA. AS WITH DAYS PAST...AS THIS TSRA BAND APPROACHES NERN IA AND SWRN WI AFTER 5 PM...CONVECTIVE ACTIVITY IS EXPECTED TO DEGRADE. SOME SMALL HAIL IS POSSIBLE FROM THE STORMS IN THE SOUTHERN FORECAST AREA...BUT THEN A TRANSITION TO A MORE STRATIFORM RAIN REGION WILL OCCUR. THERE IS EXCELLENT AGREEMENT ON THE MODEL GUIDANCE ON THE BAND ROTATING NORTH THROUGH THE AREA OVERNIGHT. HAVE FORECAST AMOUNTS OF LESS THAN ONE-HALF OF AN INCH. WITH MODELS TOO HIGH ON PRECIPITABLE WATER...HAVE DISCOUNTED HEAVIER RAINFALL TOTALS SUCH AS THE 28.12Z. THE BAND WILL ROTATE INTO THE NORTHERN FORECAST AREA TUESDAY MORNING AND SLOW ITS PROGRESS AS THE SURFACE LOW SHIFTS TOWARD ROCKFORD IL. THIS WILL PROVIDE A QUICK WARM UP TO THE BOUNDARY LAYER AND SOME INSTABILITY ACROSS SOUTHWEST WI FOR A TIME TUESDAY. HAVE ADDED SOME THUNDER THERE BUT DO NOT EXPECT MORE THAN PEA SIZED HAIL WITH 250 J/KG OF CAPE OR SO. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 322 PM MON APR 28 2014 TUESDAY NIGHT THROUGH THURSDAY NIGHT THE AREA WILL BE RIGHT UNDER THE OCCLUDED DEEP LOW WITH SPOKES OF ENERGY CONTINUING TO ROTATE THROUGH THE AREA. THE MODEL GUIDANCE AGREES ON THE BIG PICTURE BUT THE DETAILS OF TIMING ON RAIN CHANCES ARE ALL OVER THE PLACE AMONG ALL THE AVAILABLE MODELS. HAVE KEPT THIS PERIOD SHOWERY WITH MUCH LIGHTER WINDS THAN WE HAVE SEEN. FAIRLY SATURATED CONDITIONS AND SHORTWAVES THAT WILL BE ROTATING THROUGH THE LONG WAVE WILL BRING MORE ORGANIZED SHOWER AREAS I AM SURE. AT THIS POINT...RAISED RAIN CHANCES THROUGH THIS PERIOD TO AT LEAST 60 PERCENT WITH MORE DETAIL TO BE ADDED AS WE GET CLOSER TO THOSE DAYS AND CAN IDENTIFY WHERE TO IMPROVE THE FORECAST. COOL AND CLOUDY WITH LIGHT RAINFALL /LESS THAN ONE TENTH PER 12 HOURS/ FOR MOST EVERYWHERE. FRIDAY THROUGH MONDAY A BELOW NORMAL TEMPERATURE PERIOD. LONG WAVE TROUGH AND SHORTWAVE ACTIVITY SPOKING AROUND THE LOW WILL MAKE FOR DETAILS IN THIS PERIOD DIFFICULT. BY FRIDAY IT WOULD APPEAR THE MODEL CONSENSUS SUGGEST THE AREA INTO NORTHWEST FLOW WHICH CAUSES ITS OWN ISSUES FOR TIMING OF SHOWERS WITH SHORTWAVE TROUGHS. HEIGHTS RISE MORE OVER THE GREAT LAKES ON FRIDAY NIGHT AND SATURDAY AS ENERGY CRASHES ONTO THE WEST COAST. THIS ENERGY THEN EJECTS INTO THE PLAINS BY LATER SATURDAY WITH CYCLOGENESIS AND SOUTHERLY RETURN FLOW ACTIVATING ON THE FRONT TO THE SOUTHWEST. FOR A 150 HOUR FORECAST...THERE IS PRETTY GOOD AGREEMENT WITH THE LATEST TWO RUNS OF THE ECMWF/GFS MODELS THAT SHOWERS/RAIN WILL SPREAD ACROSS THE REGION SUNDAY WITH THE NORMAL WARM FRONTAL LIFT SIGNALS OF ISENTROPIC LIFT...MOISTURE TRANSPORT CONVERGENCE. WHILE PLACEMENT IS VARIED...THE GENERAL AGREEMENT ADDS TO CONFIDENCE. BOTTOM LINE IS SATURDAY LOOKS LIKE THE DRIER DAY STILL BUT CONFIDENCE IS SOMEWHAT LOW WITH NORTHWEST FLOW VERY DIFFICULT TO FORECAST 5 DAYS OUT. TEMPERATURES DONT LOOK TO REBOUND MUCH UNTIL SATURDAY...BUT CLOUDS MAKE ALL THE DIFFERENCE THIS TIME OF YEAR. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 1215 PM CDT MON APR 28 2014 AN EXTENDED PERIOD OF MVFR/IFR CIGS SETTING UP FOR THE TAF SITES. THIS AS A LARGE/COLD/MOIST SFC TO MID LEVEL LOW OVER THE CENTRAL PLAINS DRIFTS SLOWLY NORTHEAST INTO THE UPPER MIDWEST. MAINLY VFR VSBYS EXPECTED AS BRISK...BUT DRIER...EASTERLY BECOMING NORTHEAST AND NORTH SFC-925MB FLOW CONTINUES OVER SOUTHEAST MN/WESTERN WI THRU TONIGHT/TUE. SOME MVFR/LCL IFR VSBYS EXPECTED IN BANDS OF HEAVIER RAIN AS THEY ROTATE NORTH AND NORTHWEST ACROSS THE AREA. ONE OF THESE TO IMPACT THE TAF SITES INTO THE EARLY AFTERNOON HOURS TODAY...WITH ANOTHER EXPECTED TO LIFT NORTH ACROSS THE TAF SITES DURING THE LATER EVENING AND OVERNIGHT HOURS. GENERALLY LIGHTER PRECIP EXPECTED TUE WITH MAINLY VFR VSBYS. TIGHT PRESSURE GRADIENT AND BRISK/GUSTY EAST WINDS WILL PERSIST ACROSS THE TAF SITS THIS AFTERNOON/EVENING. AS THE SFC LOW MOVES INTO EASTERN IA/NORTHERN IL LATER TONIGHT/TUE...PRESSURE GRADIENT OVER THE AREA WILL RELAX WITH WINDS STILL BRISK BUT MORE IN THE 10- 20KT RANGE AND BECOMING NORTHEAST TO NORTH. && .HYDROLOGY... ISSUED AT 322 PM CDT MON APR 28 2014 AFTER RECEIVING LESS RAIN OVERNIGHT THAN ORIGINALLY THOUGHT...THE RIVER SITUATION SEEMS LIKE IT WILL BEHAVE FOR THIS STORM. WE ARE EXPECTING ABOUT 0.50 TO 0.75 INCHES OF RAIN TONIGHT AND TUESDAY FOR MOST AREAS WHICH WILL MEAN BANKFULL RIVER RISES FOR MOST RIVERS...AND A LOW FLOODING THREAT. THE KICKAPOO MAY BE THE CLOSEST RIVER TO FLOODING. MAYBE THE MAIN STORY IS THE MISSISSIPPI RIVER THAT WILL SWALLOW ALL THE INCOMING TRIBUTARY WATER AND CONTINUE TO RISE ALL NEXT WEEK. FROM WINONA MN SOUTH...IT APPEARS THE MISSISSIPPI RIVER WILL BE APPROACHING MINOR FLOOD LEVELS BY LATER THIS WEEK...WITH FLOODING LIKELY FURTHER NORTH. THE FLOOD WATCH HAS BEEN ISSUED FOR THE WINONA AND SOUTH FLOODING THREAT. AFTER TONIGHT...RAINFALL AMOUNTS WILL TURN MORE SHOWERY AS THE GULF MOISTURE PLUME IS SHUNTED EAST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR WIZ041-053-054-061. MN...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR MNZ088-096. IA...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR IAZ011-030. && SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...SWERMAN HYDROLOGY...BAUMGARDT
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND TUESDAY ISSUED AT 240 PM CDT MON APR 28 2014 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A LARGE AND STUBBORN UPPER LOW SPINNING OVER THE CENTRAL GREAT PLAINS AND A WARM FRONT POSITIONED OVER CENTRAL IOWA TO CENTRAL INDIANA. WARM CONVEYOR BELT IS RISING OVER THE 850MB FRONT LOCATED OVER SOUTHERN WISCONSIN AND ALONG WITH MID-LEVEL FGEN...IS HELPING TO PRODUCE AN ARCING BAND OF RAIN FROM CENTRAL MINNESO