Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/29/13


AREA FORECAST DISCUSSION
NWS PUEBLO CO
703 PM MDT MON OCT 28 2013 .UPDATE... ISSUED AT 637 PM MDT MON OCT 28 2013 UPDATED TO FORECAST TO REFLECT THE LATEST SATELLITE TRENDS AND HIGH-RES MODEL GUIDANCE...A BLEND OF THE HRRR AND WRF. DELAYED THE PRECIPITATION FOR MOST OF THE NIGHT ALONG THE CONTINENTAL DIVIDE WITH A RAMP UP OF POPS BY TUESDAY MORNING. BEFORE THAT...JUST ISOLATED SNOW SHOWERS ARE EXPECTED WITH AN INCH OR TWO POSSIBLE ACROSS THE PEAKS. REMOVED THE THUNDERSTORM CHANCES ALONG THE KANSAS BORDER FOR THIS EVENING...LATEST RADAR TRENDS HAVE THUNDERSTORMS WELL INTO KANSAS...WITH VERY LIMITED MOISTURE AND FORCING OVER OUR EASTERN COUNTIES. LOW STRATUS OVER NORTHEAST COLORADO WILL SHIFT SOUTH ACROSS THE PLAINS THROUGH THE OVERNIGHT. THIS AREA OF MOISTURE IS VERY SHALLOW WITH PATCHY FOG...AND OVERCAST CONDITIONS ACROSS MUCH OF THE PLAINS. THERE MAY ALSO BE SOME PATCHY FREEZING DRIZZLE OVER THE PALMER DIVIDE...AND CAUTION IS ADVISED TOWARD MORNING FOR PATCHY BLACK ICE. ELSEWHERE...MOISTURE LOOKS TO BE TOO SHALLOW FOR DRIZZLE. DELAYED WARMING ALONG THE ARKANSAS RIVER VALLEY FOR TOMORROW MORNING. PUEBLO MAY BE IN THE 30S TO 40S FOR MUCH OF THE DAY UNTIL MIXING TAKES OVER BY MID AFTERNOON. MOZLEY && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 337 PM MDT MON OCT 28 2013 COOL FRONT HAS SLIPPED DOWN TO THE CO/NM BORDER WITH THE BOUNDARY JUST N OF THE STATE LINE. NE COLO WAS SOCKED IN WITH LOW CLOUDS AND THESE CLOUDS WERE JUST MAKING IT INTO EXTREME N AND NE EL PASO COUNTY. A COUPLE OF WELL DEFINED WIND SHIFT LINES WERE NOTED OVER S EL PASO AND N PUEBLO COUNTIES. THESE BOUNDARIES WERE ASSOCIATED WITH WIND SHIFT LINES (NE WINDS VS SE WINDS). ELSEWHERE...A STRONG UPPER LOW WAS NOTED OVER NEVADA AND WAS MOVING SLOWLY EAST. QUITE A BIT OF DRY AIR IN THE UPPER LEVELS WAS NOTED IN ADVANCE OF THIS SYSTEM PER WATER VAP IMGY. REST OF TODAY INTO TONIGHT... FIRST CONCERN WILL BE THUNDER. SIMULATIONS CONTINUE TO SHOW TSRA BREAKING OUT ALONG THE CO/KS BORDER EARLY THIS EVENING. FOR THIS REASON KEPT VERY SLIGHT POPS ALONG THE BORDER FOR THIS EVENING. I AM HIGHLY CONFIDENT CONVECTION WILL OCCUR...BUT DO NOT KNOW WHICH SIDE OF THE BORDER IT WILL INITIATE ON. SPC HAS THE AREA OUTLOOKED WITH A 5% CHANCE OF SVR (HAIL). 2ND CONCERN IS LOW CLOUDS/FOG TONIGHT. VERY CONFIDENT LOW CLOUDS WILL BE OVER MOST OF THE PLAINS TONIGHT...HOWEVER CONFIDENCE IS NOT TOO HIGH ON HOW FAR WEST THESE CLOUDS WILL MAKE IT BACK TOWARDS THE MTNS. LATEST HRRR HAS BECOME A BIT MORE AGGRESSIVE MOVING THE CLOUDS ALL THE WAY BACK TO THE MTNS. CONCEPTUALLY...THIS LOOKS REALISTIC AND WILL LIKELY ADD MORE CLOUDS INTO THE NDFD. OVER THE CONTDVD...MSTR WILL SLOWLY INCREASE TONIGHT...BUT EXPECT MAINLY SNOW SHOWERS...ESPECIALLY THE SAN JUANS...WITH INSIGNIFICANT ACCUMS. SOME FREEZING FOG WILL BE POSSIBLE TONIGHT OVER EL PASO COUNTY. TUESDAY... UPPER LOW WILL MOVE CLOSER TO THE REGION AND FLOW ALOFT WILL INTENSIFY. SFC BOUNDARY ALONG THE CO/NM BORDER WILL LIKELY PUSH NORTH TOMORROW...BUT HOW FAR N IS THE QUESTION. ATTM...I HAVE THE BOUNDARY RUNNING ROUGHLY FROM KCOS DOWN TO KSPD BY MID AFTERNOON TOMORROW. LIKEWISE...GUSTY SW WINDS WILL BE LIKELY OVER THE S TIER FOR THE FCST AREA...AND WE WILL LIKELY MIX OUT ACROSS EL PASO SO COULD SEE SOME GUSTY WARM WINDS THIS LOCATION BY MID DAY. IT IS POSSIBLE KPUB AREA WILL NOT MIX OUT TOMORROW WHILE EL PASO COUNTY DOES MIX OUT. HIGH TEMPS TOMORROW AT KCOS MAY BE WARMER THAN KPUB. IF THIS VERIFIES...THEN CURRENT FCST WILL NEED TO BE ADJUSTED BY LATER SHIFTS. SNOWS WILL GRADUALLY RAMP UP OVER THE MTNS ALONG THE CONTDVD...ESPECIALLY LATER TOMORROW AFTERNOON. COULD SEE A COUPLE OF INCHES OF SNOW...ESPECIALLY ABOVE 10KFT BY LATE TOMORROW AFTERNOON. IT WILL LIKELY BE WINDY ANY WHERE SOUTH OF THE FRONT...WITH GUSTS TO 25 TO 35 MPH POSSIBLE...AND 40 TO 45 MPH OVER THE HIGHER TRRN. /HODANISH. .LONG TERM...(TUESDAY NIGHT THROUGH NEXT MONDAY) ISSUED AT 337 PM MDT MON OCT 28 2013 UNSETTLED METEOROLOGICAL CONDITIONS ARE ANTICIPATED OVER PORTIONS OF THE FORECAST DISTRICT FROM TUESDAY NIGHT INTO THURSDAY...ESPECIALLY OVER THE CENTRAL MOUNTAINS...AS A UPPER SYSTEM IMPACTS THE CWFA DURING THIS TIME-FRAME. A RETURN TO DRIER AND WARMER CONDITIONS IS THEN PROJECTED TO RETURN TO THE FORECAST DISTRICT BY THIS WEEKEND. RECENT LONGER RANGE COMPUTER SIMULATIONS AND FORECAST MODEL SOUNDINGS SUGGEST THAT DOUBLE-BARRELED CLOSED UPPER LOW INITIALLY LOCATED OVER NORTHWESTERN WYOMING AND SOUTHERN NEVADA RESPECTIVELY AT 06Z WEDNESDAY WILL ROTATE INTO AN EASTERN WYOMING/SOUTHWESTERN COLORADO LOCATION BY 00Z THURSDAY BEFORE SHIFTING EAST OF THE FORECAST DISTRICT BY 18Z THURSDAY. THIS SYSTEM WILL BE CAPABLE OF GENERATING SEVERAL INCHES OF ACCUMULATING SNOW OVER PORTIONS OF THE SOUTHWESTERN AND ESPECIALLY CENTRAL MOUNTAINS FROM TUESDAY NIGHT INTO THURSDAY MORNING(I.E. PORTIONS OF PUBLIC ZONES 58/59/60 AND POSSIBLY 66/68 AND 82). IN ADDITION...EVEN A FEW INCHES OF SNOW WILL BE POSSIBLE OVER PORTIONS OF EL PASO AND TELLER COUNTIES AS WELL AS POSSIBLY THE SANGRE DE CRISTO AND WET MOUNTAINS...ESPECIALLY FROM LATER WEDNESDAY INTO WEDNESDAY NIGHT. AT THIS TIME IT APPEARS THAT PRIMARILY WINTER WEATHER ADVISORY SNOW AMOUNTS WILL BE MOST LIKELY WITH THIS EVENT OVER PORTIONS OF PUBLIC ZONES 58/59/60 AND POSSIBLY 66/68 AND 82 FROM TUESDAY NIGHT INTO THURSDAY MORNING...ESPECIALLY IF THE 12Z/28TH ECMWF SOLUTION VERIFIES. ZONE 60 MAY BE THE MOST PRONE TO RECEIVE WINTER STORM WARNING TOTALS WITH THIS EVENT...ONCE AGAIN IF THE 12Z/28TH ECMWF IS CORRECT. WFO PUEBLO WILL MONITOR CLOSELY AND ISSUE NEEDED HIGHLIGHTS AS NEEDED AND AS WE NEAR THIS POTENTIAL EVENT. GUSTY WINDS(AROUND 50 KNOTS AT TIMES)...PRIMARILY FAVORING HIGHER TERRAIN LOCATIONS ARE ALSO ANTICIPATED TUESDAY NIGHT AND THEN AGAIN FROM LATER WEDNESDAY NIGHT INTO THURSDAY NIGHT. AS TOUCHED UPON BRIEFLY EARLIER...A RETURN TO WARMER AND DRIER CONDITIONS SHOULD THEN BE EXPERIENCED OVER THE FORECAST DISTRICT BY THIS WEEKEND AS DRY NORTHWESTERLY TO ZONAL UPPER FLOW DEVELOPS OVER SOUTHERN COLORADO. FINALLY...WARMEST MAXIMUM TEMPERATURES OF THE LONGER TERM ARE EXPECTED THIS WEEKEND. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 337 PM MDT MON OCT 28 2013 LATEST HRRR IS MORE AGGRESSIVE WITH CLOUDS MAKING IT BACK TO THE MTNS. LOW CIGS MAY AFFECT KCOS AND KPUB BY 06Z...AND MAY LAST THROUGH MID MORNING. WILL MAKE AMENDMENTS TO TAF BEFORE ROUTINE 00Z ISSUANCE. KALS WILL BE VFR TONIGHT. IT WILL LIKELY BE WINDY AT ALL TAF SITES TOMORROW WITH GUSTY SW WINDS. HOWEVER...THERE IS A CHANCE THAT KPUB MAY NOT MIX OUT AND WINDS MAY REMAIN LIGHT. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MOZLEY
AREA FORECAST DISCUSSION
NWS ALBANY NY
117 AM EDT SUN OCT 27 2013 .SYNOPSIS... LOW PRESSURE WILL TRACK EASTWARD ACROSS SOUTHERN QUEBEC OVERNIGHT...WHILE A COLD FRONT ASSOCIATED WITH THE LOW WILL MOVE THROUGH THE REGION TOWARDS DAYBREAK. SOME RAIN SHOWERS AND HIGH ELEVATION SNOW SHOWERS WILL ACCOMPANY THE FRONT AS IT PASSES THROUGH. BEHIND THE FRONT...IT WILL BE COOL AND BREEZY FOR SUNDAY BEFORE ANOTHER COLD FRONT APPROACHES FROM THE GREAT LAKES SUNDAY NIGHT...AND CROSSES OUR REGION ON MONDAY WITH PERHAPS A FEW MORE SHOWERS. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 115 AM EDT...THE SFC CYCLONE CONTINUES TO MOVE ACROSS S-CNTRL QUEBEC WITH A TRAILING COLD FRONT MOVING ACROSS LAKE ONTARIO AND WRN NY AT THIS TIME. THE LOW-LEVEL CONVERGENCE HAS INCREASED AHEAD OF THE BOUNDARY NEAR THE LAKE SHORES FOR AN INCREASE IN SHOWERS OVER W-CNTRL NY. THE WARM ADVECTION PCPN HAS DRIED UP OVER THE FCST AREA...AND MUCH OF IT HAS ERODED DUE TO THE DRY LOW LEVELS THAT IS EVIDENT IN THE 00Z KALB SOUNDING BELOW THE 775 HPA LAYER. THE T/TD DIFFERENCES ARE LARGE...AND LOWER ELEVATIONS ONLY RECEIVED MAINLY SPRINKLES. THE PCPN SHOULD INCREASE BETWEEN 03Z-06Z BASED ON THE HRRR WITH THE FRONT APPROACHING THE NW ZONES /WRN DACKS/...WITH SOME LAKE MOISTURE BEING TAPPED. HIGH CHC AND LIKELY POPS WERE CONTINUED OVER THE WRN DACKS...AND W-CNTRL MOHAWK VALLEY DURING THE OVERNIGHT. THE BOUNDARY BECOMES MORE MOISTURE STARVED...AS IT HEADS EASTWARD TOWARDS THE HUDSON RIVER VALLEY AND WRN NEW ENGLAND BTWN 06Z-12Z. ONLY SLIGHT OR VERY LOW CHC POPS WERE CONTINUED FROM THE CAPITAL REGION...AND BERKSHIRES NORTHWARD OVERNIGHT. SNOW AMOUNTS WERE LOWERED TO AN INCH OR SO OVER THE WRN DACKS. FOR ELEVATIONS BELOW 1000 FT WEST OF THE CAPITAL REGION AND THE HUDSON RIVER VALLEY...ANY LIGHT SNOW WILL DEPEND HOW FAST THE COLD ADVECTION SWEEPS IN BTWN 06Z- 12Z...WITH MAINLY RAIN SHOWERS EXPECTED. OVERALL...THIS IS SHAPING UP AS A VERY LIGHT PCPN EVENT. LOWS STILL LOOK TO RANGE FROM THE U20S OVER THE SRN DACKS TO M30S OVER THE CAPITAL REGION...MID HUDSON VALLEY...TACONICS...BERKSHIRES...AND NW CT. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/... ON SUNDAY...LOOKS TO FEATURE MAINLY DRY WEATHER IN THE VALLEYS WITH STILL A CHANCE OF LINGERING RAIN AND SNOW SHOWERS MAINLY NORTH AND WEST OF THE CAPITAL DISTRICT. IT WILL BE BREEZY WITH A FAIRLY STRONG NORTHWEST WIND WITH GUSTS OVER 25 MPH AT TIMES. MUCH OF THE DAY WILL FEATURE A CYCLONIC FLOW REGIME SO THERE COULD BE A DECENT AMOUNT OF STRATOCUMULUS CLOUDS AROUND...ESPECIALLY OVER THE HIGHER TERRAIN. TEMPS SHOULD REMAIN BELOW NORMAL ONCE AGAIN WITH HIGHS RANGING FROM THE LOW TO MID 40S NORTHWEST TO MID 50S SOUTHEAST. SUNDAY NIGHT...WILL HAVE TO WATCH FOR SOME POSSIBLE LAKE EFFECT DEVELOPMENT OVER THE WESTERN ADIRONDACKS AS THE LOW STARTS TO BACK TO A MORE WEST-SOUTHWEST DIRECTION AHEAD OF THE NEXT UPPER LEVEL SHORT WAVE AND SURFACE COLD FRONT DIVING SOUTHEASTWARD ACROSS ONTARIO. WILL MENTION CHANCE POPS FOR NOW...AS THE FLOW SHOULD BE FAIRLY TRANSITORY WITH SHORT WAVE FORECAST TO MOVE RATHER QUICKLY. LOWS SUNDAY NIGHT ARE EXPECTED TO BE IN THE UPPER 20S TO LOWER 30S. THE MAIN ENERGY ALOFT SHOULD PASS BY NORTH OF THE AREA ON MONDAY...WHILE THE SURFACE COLD FRONT MOVES THROUGH OUR AREA. VERY LIMITED MOISTURE AS WELL...SO WILL ONLY MENTION SLIGHT CHANCE TO LOW CHANCE POPS NORTH AND WEST OF ALBANY ASSOCIATED WITH THE FRONT. THE FRONT IS EXPECTED TO CLEAR THE AREA BY LATE MONDAY AFTERNOON. EXPECT HIGHS ON MONDAY TO BE IN THE MID 40S TO MID 50S DRY AND COLD CONDITIONS ARE EXPECTED FOR MONDAY NIGHT AND TUESDAY AS STRONG RIDGE OF HIGH PRESSURE BUILDS SOUTHEAST FROM CANADA AND MOVES ACROSS OUR REGION. EXPECT LOWS MONDAY NIGHT TO RANGE FROM THE MID TEENS NORTHWEST TO LOWER 30S SOUTHEAST. HIGHS ON TUESDAY ARE EXPECTED TO BE IN THE 40S. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... WITH THE FAST UPPER FLOW THROUGH THE PERIOD...THE TIMING OF THE SYSTEMS...AND TIMING OF RAIN AND DRY PERIODS...AS WELL AS CLOUD COVER TRENDS...WILL LIKELY BE ADJUSTED WITH EACH SET OF GUIDANCE OVER THE NEXT SEVERAL DAYS. TUE NT-WED...BASED ON CURRENT GUIDANCE/ENSEMBLES...A FAST MOVING NORTHERN STREAM UPPER IMPULSE TRACKS ACROSS THE GREAT LAKES AND ACROSS OUR REGION TUESDAY NIGHT INTO EARLY WEDNESDAY. MODELS DIFFER ON THE SFC REFLECTION...AND DEGREE OF MOISTURE THIS SYSTEM WILL HAVE ACROSS OUR REGION. THE 12Z/GEFS...GFS AND GEM INDICATE THAT A SFC WAVE DEVELOPS ALONG THE FRONTAL BOUNDARY AND PASSES SOUTH OF THE REGION TUE NT-WED MORNING. THE COMBINATION OF UPPER LEVEL DYNAMICS...AND MID LEVEL MOISTURE CONTRIBUTES TO LIGHT QPF ACROSS THE REGION. THE ECMWF APPEARS A BIT LESS EMPHATIC OVERALL WITH SFC REFLECTION AND QPF...AND SLIGHTLY FURTHER SOUTH. WILL INDICATE SLIGHT CHC POPS AT THIS TIME...TO ACCOUNT FOR THE POSSIBILITY THAT AT LEAST SOME LIGHT PRECIPITATION OCCURS AS THIS SYSTEM PASSES SOUTH OF THE REGION. THERMAL PROFILES SUGGEST ENOUGH COLD AIR WOULD BE IN PLACE TO SUPPORT SOME SNOW OR A WINTRY MIX...ESPECIALLY FROM AROUND INTERSTATE 90 NORTH...SHOULD PRECIP REACH THAT FAR NORTH. EXPECT ANY PRECIP TO TAPER OFF BY WED AFTERNOON. EXPECT TUE NT/WED AM MINS TO FALL INTO THE 20S AND 30S...WITH WED MAX TEMPS REACHING THE 40S IN MOST VALLEYS...EXCEPT SOME LOWER 50S POSSIBLE IN THE MID HUDSON VALLEY...WITH HIGHER ELEVATIONS MAINLY REMAINING IN THE UPPER 30S TO MID 40S. WED NT-THU NT...WARM ADVECTION STRENGTHENS AHEAD OF THE NEXT SYSTEM WEDNESDAY NIGHT INTO THURSDAY NIGHT. HAVE INDICATED THE CHANCES POPS FOR SHOWERS FOR THU AFTERNOON/NIGHT...WITH THE GREATEST CHANCES ACROSS NORTHERN AREAS. EXPECT TEMPS TO FALL INTO THE UPPER 20S TO MID 30S WED NT...RISE INTO THE 50S ON THU...AND DROP TO 45-50 FOR THU NT. FRI-SAT...A DYNAMIC SYSTEM TRACKS NORTH AND WEST OF THE REGION DURING THIS PERIOD...WITH THE POTENTIAL FOR SOME WINDY WEATHER...ALONG WITH RAIN SHOWERS. HIGHS FRIDAY IN THE 60S IN VALLEYS...AND 50S ACROSS HIGHER ELEVATIONS...WITH OVERNIGHT MINS FRI NT/SAT AM MAINLY IN THE 40S AND LOWER 50S. ONCE THE COLD FRONT EXITS SATURDAY...THERE ARE INDICATIONS THAT THE COLD ADVECTION MAY BE A BIT MODIFIED SINCE THE MEAN UPPER TROUGH COULD SET UP FAR ENOUGH WEST TO KEEP THE CORE OF THE COLDEST AIR JUST TO THE WEST. HIGHS SATURDAY AROUND 60 TO MID 60S...MID TO UPPER 50S IN THE SOUTHERN ADIRONDACKS AND SOUTHERN GREEN MOUNTAINS. && .AVIATION /05Z SUNDAY THROUGH THURSDAY/... LOW PRESSURE CONTINUES TO MOVE ACROSS SOUTHERN QUEBEC. A COLD FRONT ASSOCIATED WITH THE LOW PRESSURE SYSTEM WILL MOVE ACROSS ERN NY AND WRN NEW ENGLAND TOWARDS DAYBREAK THIS MORNING. HIGH PRESSURE WILL RIDGE IN FROM THE OHIO VALLEY LATE THIS AFTERNOON. VFR CONDITIONS WILL PREVAIL MOST OF THE NEXT 24 HOURS. SOME SPOTTY OR ISOLD SHOWERS/SPRINKLES WILL BE NEAR THE TAF SITES THROUGH ABOUT 10Z. VCSH GROUPS WERE USED FOR THE SPRINKLES IN THE AREA. ANY MVFR CEILINGS SHOULD BE TOO BRIEF TO MENTION IN TAFS THROUGH 12Z-13Z SO WILL NOT INCLUDE...BUT BEST CHANCES FOR BRIEF MVFR CEILINGS WOULD BE KGFL AND KPSF. AS THE FRONT CLEARS THE TAF SITES BTWN 10Z-13Z...THE WINDS WILL INCREASE FROM THE WEST. VFR CONDITIONS WILL CONTINUE INTO THE AFTERNOON AND EVENING WITH SOME SCT STRATOCUMULUS AND MID TO HIGH CLOUDS AROUND DECREASING TO SKC THIS EVENING. SOUTH TO SOUTHWEST AT 5-10 KTS WILL VEER TO W/SW AFTER THROUGH THE EARLY MORNING HOURS AT LESS THAN 10 KTS...AND THEN INCREASE FROM THE WEST IN THE MID TO LATE MORNING INTO THE AFTERNOON AT 10-15 KTS WITH SOME GUSTS IN THE 20-25 KT RANGE...ESPECIALLY AT KALB AND KPSF. WINDS SHOULD DIMINISH TO LESS THAN 6 KT THIS EVENING. OUTLOOK... SUN NIGHT-TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. TUE NIGHT: MODERATE OPERATIONAL IMPACT. ISOLATED SHRA...SHSN. WED-WED NT: MODERATE OPERATIONAL IMPACT. ISOLATED SHRA. THURSDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA. && .FIRE WEATHER... LOW PRESSURE WILL TRACK EASTWARD THROUGH SOUTHEAST CANADA TONIGHT...WHILE A COLD FRONT ASSOCIATED WITH THE LOW WILL PUSH THROUGH OUR REGION LATE TONIGHT. SOME RAIN SHOWERS AND HIGH ELEVATION SNOW SHOWERS WILL ACCOMPANY THE FRONT AS IT PASSES THROUGH. BEHIND THE FRONT...IT WILL BE COOL AND BREEZY FOR SUNDAY BEFORE ANOTHER COLD FRONT APPROACHES FROM THE GREAT LAKES SUNDAY NIGHT...AND CROSSES OUR REGION ON MONDAY WITH PERHAPS A FEW MORE SHOWERS. && .HYDROLOGY... NO HYDRO ISSUES ARE ANTICIPATED THROUGH AT LEAST THE NEXT 5 DAYS. OVERALL RIVER AND STREAM LEVELS ARE NEAR TO SLIGHTLY BELOW NORMAL FOR LATE OCTOBER. ONLY SOME LIGHT PRECIPITATION IS EXPECTED THROUGH THE MIDDLE OF NEXT WEEK FROM A FEW FRONTAL BOUNDARIES AND DISTURBANCES THAT WILL CROSS THE REGION THIS WEEKEND INTO EARLY NEXT WEEK AS WELL AS SOME LAKE EFFECT RAIN AND SNOW SHOWERS ACROSS THE WESTERN ADIRONDACKS. 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/JPV/WASULA NEAR TERM...JPV/WASULA SHORT TERM...11/JPV LONG TERM...KL/NAS AVIATION...NAS FIRE WEATHER...11 HYDROLOGY...11/JPV
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
402 AM EDT SUN OCT 27 2013 .SYNOPSIS... A COLD FRONT WAS MAKING ITS WAY ACROSS OUR REGION EARLY THIS MORNING. THE BOUNDARY SHOULD BE FOLLOWED BY HIGH PRESSURE FOR TODAY INTO MONDAY. ANOTHER COLD FRONT IS FORECAST TO ARRIVE ON MONDAY EVENING WITH HIGH PRESSURE EXPECTED TO NOSE INTO OUR REGION FROM THE NORTHWEST FOR TUESDAY AND WEDNESDAY. THE CENTER OF THE HIGH IS ANTICIPATED TO PASS OFF THE COAST LATE ON WEDNESDAY WITH A WARM FRONT EXPECTED TO LIFT THROUGH OUR REGION ON WEDNESDAY NIGHT OR THURSDAY. A STRONG COLD FRONT FROM THE WEST IS FORECAST TO ARRIVE EARLY ON SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A FAIRLY SHARP MID-LVL SHRTWV TROF IS MOVG EWD THROUGH PA AND IS FCST TO BE OFF THE NJ COAST BY AROUND 12Z. THE RAP INDICATES STRONG DOWNWARD VV AND DRYING BEHIND THE TROF WHICH IS HELPING TO DECREASE CLOUDS OVER MUCH OF PA ATTM. THIS TREND IS EXPECTED TO SHIFT EWD SO THAT BY SUNRISE THE CLOUDS SHOULD HAVE CLEARED OVER MOST OF ERN PA AS WELL AS NJ AND NRN DELMARVA. THE ASSOCD SFC FRONT IS NOT PARTICULARLY WELL DEFINED IN THE SFC OBS BUT THERE IS A DEFINITE WIND SHIFT FROM SW TO WEST. MID CLOUDS ASSOCD WITH THE FRONTAL BAND HAVE KEPT OVERNIGHT TEMPS FROM FALLING...BUT WITH A CLEARING TREND TEMPS MAY FALL YET A FEW DEGREES BEFORE SUNRISE. FOR TODAY...THERE IS ONLY RATHER WEAK COLD ADVECTION BEHIND THE FRONT AND WITH MOSTLY SUNNY SKIES MAX TEMPS THIS AFTERNOON WILL BE SIMILAR TO YDAY. WINDS NEAR THE TOP OF THE PBL ARE FCST AT 20-25 KT AND MIXING SHOULD BRING MOMENTUM DOWN RESULTING IN SOME GUSTINESS AT TIMES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... RATHER FLAT ZONAL FLOW ALOFT WITH LOW RH AND WEAK SUBSIDENCE SHOULD RESULT IN A CLEAR NIGHT WITH LIGHT TO CALM WINDS. WITH GOOD RADIATING CONDS OVERNIGHT MINS SHOULD BE IN THE 30S EXCEPT LOW 40S IN AND AROUND PHILA METRO AREA AND NEAR THE SHORE. FOR AREAS WHERE THE GROWING SEASON IS STILL ACTIVE...SOME SCT FROST IS POSSIBLE BUT A FREEZE IS NOT EXPECTED ATTM. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... THE MID LEVEL LONG WAVE TROUGH IS FORECAST TO LOSE IT INFLUENCE OVER OUR REGION GRADUALLY DURING THE FIRST HALF OF THE NEW WEEK AS THE FEATURE LIFTS TO THE NORTHEAST. ON MONDAY MORNING, SURFACE HIGH PRESSURE IS EXPECTED TO COVER MUCH OF THE SOUTHEASTERN STATES AND THE MIDDLE ATLANTIC REGION AS WELL AS THE ADJACENT OCEAN WATERS. A COLD FRONT IS FORECAST TO EXTEND FROM THE SAINT LAWRENCE RIVER VALLEY, ACROSS THE SOUTHERN PART OF THE GREAT LAKES REGION TO THE CENTRAL PLAINS. THE BOUNDARY IS ANTICIPATED TO DROP THROUGH OUR REGION LATE ON MONDAY. THE SEGMENT THAT SHOULD AFFECT US WILL LIKELY HAVE LIMITED MOISTURE ASSOCIATED WITH IT. AS A RESULT, NO PRECIPITATION IS EXPECTED. SURFACE HIGH PRESSURE FROM THE NORTHWEST IS FORECAST TO BUILD ACROSS THE GREAT LAKES AND TOWARD OUR REGION ON MONDAY NIGHT AND TUESDAY. THE CENTER OF THE HIGH SHOULD PASS OFF THE COAST LATE ON WEDNESDAY. THE PERIOD SHOULD BE DRY WITH ONE POSSIBLE EXCEPTION. A MID LEVEL SHORT WAVE TRAVELING IN THE DEPARTING CYCLONIC FLOW IS EXPECTED TO PASS OVERHEAD LATE ON TUESDAY NIGHT. THE LATEST GUIDANCE IS SUGGESTING SOME RAIN WITH THE FEATURE. FOR NOW, WE WILL CARRY A SLIGHT CHANCE OF RAIN SHOWERS. IF THE TREND CONTINUES IN SUBSEQUENT RUNS OF THE MODELS, WE WILL LIKELY INCREASE THE PROBABILITY. A MID LEVEL RIDGE IS FORECAST TO BUILD TOWARD ON REGION ON WEDNESDAY WITH ITS AXIS PASSING OVERHEAD ON WEDNESDAY NIGHT. WE ARE ANTICIPATING DRY WEATHER DURING THAT PERIOD. MOISTURE IS EXPECTED TO BE ON THE INCREASE DURING THURSDAY AND FRIDAY AS A SOUTH TO SOUTHWEST FLOW BECOMES ESTABLISHED IN ADVANCE OF AN APPROACHING MID LEVEL TROUGH AND ITS ASSOCIATED COLD FRONT. WE WILL INDICATE AN INCREASING CHANCE OF RAIN SHOWERS FOR THE LATE WEEK PERIOD. WE WILL CONTINUE TO TIME THE COLD FRONT`S ARRIVAL FOR EARLY ON SATURDAY. THE BOUNDARY SHOULD BE FOLLOWED BY DRY AIR RESULTING IN A DECREASING CHANCE OF SHOWERS ON SATURDAY MORNING. TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL FOR MONDAY, TUESDAY AND WEDNESDAY. TEMPERATURES SHOULD RISE TO ABOVE NORMAL LEVELS FOR THURSDAY AND FRIDAY IN THE SOUTH TO SOUTHWEST FLOW. HIGHS ON FRIDAY ARE FORECAST TO BE IN THE UPPER 60S AND LOWER 70S IN MUCH OF OUR REGION. READINGS ARE EXPECTED TO DROP BACK TOWARD NORMAL AFTER EARLY SATURDAY`S COLD FRONTAL PASSAGE. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDS ARE EXPECTED FOR THE TAF FCST PERIOD AND WELL BEYOND. SOME MID LEVEL CLOUDS ASSOCD WITH A COLD FRONT PASSAGE ARE RAPIDLY CLEARING EWD AND WILL SOON BE OUT OF THE PICTURE. EARLIER SW WIND HAVE MOSTLY SHIFTED TO THE WEST AND SHOULD CONT FROM THE W TO WNW TODAY. SOME 15 TO 20 KT GUSTS ARE POSSIBLE AT TIME TODAY WITH DIURNAL HEATING/MIXING...BUT WILL DIMINISH BY SUNSET AND BECOME 5 KT OR LESS OVERNIGHT. OUTLOOK... MONDAY THROUGH WEDNESDAY...MAINLY VFR. WEDNESDAY NIGHT AND THURSDAY...LATE NIGHT AND EARLY MORNING LOW CLOUDS AND FOG ARE POSSIBLE. && .MARINE... THE SMALL CRAFT ADVISORY FOR THE ATLANTIC COAST WATERS HAS BEEN LEFT AS IS FOR NOW...BEING SET TO EXPIRE AT 600 AM. EARLIER GUSTY SW WINDS HAVE BEGUN SHIFTING TO THE WEST AND HAVE DIMINISHED SOMEWHAT. SEAS AT BUOY 4409 ARE STILL RUNNING AROUND 5 FT HWVR. WILL MONITOR THE MARINE OBS...WHAT WE HAVE...AND PERHAPS EXTEND THE SCA A COUPLE OF HOURS IF NEED BE. WIND AND WAVE GUIDANCE GENERALLY SHOW A DOWNWARD TREND FOR TODAY. OTRW...WINDS AND SEAS SHOULD CONT TO DIMINISH TONIGHT AS THE DIFFUSE CENTER OF SFC HIGH PRES SHIFTS EWD TO THE COAST BY EARLY MONDAY MORN. OUTLOOK... WIND SPEEDS AND WAVE HEIGHTS ARE FORECAST TO REMAIN BELOW THE SMALL CRAFT ADVISORY CRITERIA FROM MONDAY THROUGH WEDNESDAY NIGHT. WIND GUSTS MAY APPROACH 25 KNOTS ON THURSDAY IN AN INCREASING SOUTH TO SOUTHWEST SURFACE FLOW. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 5 FEET AT THAT TIME. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR ANZ450>455. && $$ SYNOPSIS...IOVINO NEAR TERM...AMC SHORT TERM...AMC LONG TERM...IOVINO AVIATION...AMC/IOVINO MARINE...AMC/IOVINO
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
654 PM CDT Mon Oct 28 2013 ...UPDATED AVIATION... .SYNOPSIS... ISSUED AT 911 AM CDT MON OCT 28 2013 The 28.12Z 250 hPa RAOB map showed WSW-WNW of around 100 kt extending from KTUS/KFGZ to KDEN. At 500 hPa, a large 542 dm cyclone was located across western Nevada. Mid level cyclonic flow and a cold pool of -25C were associated with the pressure perturbation. At 700 hPa, KDDC temp was 5C, 1 degree warming compared yesterdays 12Z RAOB. More pronounced warming was noted at 850 hPa, observed at 17C versus 11C. At the sfc, a stationary front was noted across west-central Kansas. A weak dryline was noted across south-central Kansas. Dewpoints in the 50sF were advecting in from the south, east and south of said boundaries. Hurricane Raymond was located at 15.3N 116.8W at 28.03Z. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 333 PM CDT MON OCT 28 2013 ...Low end severe weather event possible this evening... This evening: Main concern for tonight is where convection will develop. Have the most confidence in convective initiation across the west central zones along a quasi-stationary boundary. The HRRR/NAM/4km NAM and WRF-NMM core shows thunderstorms developing along this quasi-stationary boundary towards the 00-01Z time frame. 0-6 km bulk shear of 60 km is more than adequate for rotating storms. In addition, there is strong anvil layer bulk shear for good storm top ventilation. A few negatives... first, mean flow is essentially parallel to the boundary, which will favor upscale convective growth. This should limit overall hail size through means of high beneficial competition for hail embryos. Farther south, some of the mesoscale models such as the 4 km NAM show convection developing along a weak dryline across the Texas/Oklahoma panhandles and drifting NE across the southeastern zones late tonight. In this region, MUCAPE is higher (500-1500 J/kg range) and there is more orthogonality to the sfc boundary, which could favor more isolated storms later this evening. Still a few negatives here though... cloud cover has hung around and dewpoints are marginal (well for October, actually good, but for instability - marginal). Bottom line, a low end severe event with a few hail and wind reports. Tornado chances are slim to none. Tuesday: Widespread low clouds are expected through the overnight. The thermodynamic profile could support patchy drizzle late tonight into early tomorrow morning. Overnight minimums will be very mild for late October standards... low 60sF southeast to around 50F northwest. Will have to watch out for record maximum minimums being set. Otherwise, a front will bisect the region. North of the front, have gone with cooler maximums as stratus could stick around. South of the front, a 800-600 hPa dry slot could result in morning clearing. An addition, pre-frontal warming/downslope plume will result in the highest maximums south of the Arkansas river. Have a gradient of maximums from 50sF northwest to 70sF southeast. .LONG TERM...(Tuesday night through Monday) ISSUED AT 248 PM CDT MON OCT 28 2013 A surface boundary will be located across western Kansas Tuesday night. Exact location of this boundary however is still somewhat unclear, but all models were hinting at a slightly further north solution that what was previously thought. Still given this trend am leaning towards the NAMs further south solution given precipitation chances tonight across northern Kansas which will enforce the cold air north of this boundary. As a result of where this boundary will be located Tuesday night and surface dewpoints near 60F ahead of this front will raise overnight lows for south central and portions of southwest Kansas. As for precipitation chances...warm air advection/isentropic lift will develop early Tuesday night north of the surface boundary with convection developing further south appearing to hold off until a weak short wave trough moves out of the Rockies and out into the central high plains towards midnight. At this time it appears the better opportunity for precipitation will be across south central and north central Kansas between midnight and 18z Wednesday. The GFS, ECMWF, and Ensembles were in decent agreement today with the upper level trough crossing western Kansas early Thursday. As this upper level trough passes, the surface front will move south into north Texas as high pressure at the surface crosses the Rockies and approaches the central high plains from the northwest. More seasonal temperatures can be expected as this surface high builds into western Kansas late week with afternoon highs mainly in the low to mid 60s. Another upper level trough will move out of the Rockies and across the central plains late week, however only mid to high level moisture is forecast to accompany this next, weaker upper level system. A gradual warming trend can be expected over the weekend period as an upper level ridge builds across the Rockies and out into the plains. A northwest flow will back more to the west by early Sunday and a trough of low pressure at the surface will deepen along the lee of the Rockies. Following the mean 850mb temperature trends from 00z to 00z the potential exists for highs climbing back into the lower 70s by Sunday afternoon. A cold front will be moving south into the northern plains late this weekend and another pacific upper level trough is forecast to move across the pacific northwest. Timing of this next cold front moving south into the central plains on day 7 is unclear, and given the location of the upper trough by 12z Monday am currently leaning towards the slower ECMWF. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 652 PM CDT MON OCT 28 2013 Details of the terminal forecasts this evening are dependent on how widespread the convection develops through 3 and 6 UTC. The mesoscale models develop discreet supercell storms across the area, any of which would have the chance to impact the local terminals. A broken line of elevated cells has already developed near liberal, moving northeast toward Garden city. We`ve introduced TEMPO convective period to each terminal and will likely requires a few amendments thorough the evening. Following the convective threat this evening, widespread LIFR stratus is likely to develop supported by the HRRR ceiling forecast through the afternoon Tuesday. && .PRELIMINARY POINT TEMPS/POPS... DDC 59 74 54 67 / 70 10 20 20 GCK 51 66 47 61 / 80 10 20 10 EHA 46 75 45 68 / 50 10 10 10 LBL 52 77 50 69 / 50 10 10 10 HYS 57 66 49 56 / 70 20 40 30 P28 63 77 61 74 / 70 20 40 40 && .DDC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...Sugden SHORT TERM...Sugden LONG TERM...Burgert AVIATION...Russell
AREA FORECAST DISCUSSION
NWS GRAY ME
916 AM EDT SUN OCT 27 2013 .SYNOPSIS... A COLD FRONT WILL PUSH OFFSHORE TODAY FOLLOWED BY A WEAK RIDGE OF HIGH PRESSURE. A SECOND COLD FRONT WILL APPROACH FROM THE NORTHWEST TONIGHT AND WILL CROSS THE REGION ON MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY NIGHT THROUGH TUESDAY AND WILL CREST OVER THE REGION ON WEDNESDAY. A WARM FRONT WILL APPROACH FROM THE SOUTHWEST ON THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATE... DRIER AIR CONTINUES TO FILTER IN FROM THE WEST PER LATEST SATELLITE IMAGERY AND CURRENT OBSERVATIONS. HOWEVER...STILL SOME LOW LEVEL MOISTURE IN PLACE...ESPECIALLY OVER EASTERN AREAS WHERE PATCHY DRIZZLE WILL CONTINUE FOR ANOTHER HOUR THIS MORNING. OTHERWISE...THE MAJORITY OF THE PRECIPITATION HAS SHIFTED EAST TOWARDS THE PENOBSCOT RIVER VALLEY THIS MORNING. THIS SHOWER ACTIVITY WILL END AROUND 14Z PER LATEST HRRR RUN. TEMPERATURES WILL REBOUND INTO THE LOWER 50S WITH PARTIAL CLEARING TODAY. PREV DISC... COLD FRONT WILL PUSH OFFSHORE EARLY TODAY BRINGING AN END TO SHOWERS CURRENTLY PARKED OVER COASTAL SECTIONS OF MAINE AND NEW HAMPSHIRE. EXPECT PARTIAL CLEARING DOWNWIND OF THE MOUNTAINS DURING THE MORNING HOURS AND THEN VARIABLE HIGH CLOUDS THROUGH THE AFTERNOON. IN THE NORTH EXPECT SKIES TO REMAIN MOSTLY CLOUDY IN UPSLOPE AREAS FOR MUCH OF THE DAY WITH JUST A SLIGHT CHANCE OF A SPRINKLE OR FLURRY OVER THE HIGHER TERRAIN. WILL TAKE A WHILE FOR COOLER AIR TO FILTER INTO SOUTHERN ZONES WHERE HIGHS WILL TOP OUT IN THE LOWER TO MID 50S. IN THE NORTH HIGHS WILL ONLY REACH THE LOWER TO MID 40S. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... AFTER A MOSTLY CLEAR START TO THE NIGHT CLOUDS WILL BE ON THE INCREASE AGAIN AFTER MIDNIGHT AS ANOTHER COLD FRONT APPROACHES FROM THE WEST. WILL SEE A CHANCE OF SNOW SHOWERS IN NORTHERN ZONES TOWARD DAYBREAK BUT THE REMAINDER OF THE FORECAST AREA SHOULD SEE A DRY NIGHT. LOWS WILL RANGE THROUGH THE 20S IN THE NORTH AND UPPER 20S TO LOWER 30S IN THE SOUTH. LOOKING AT A MOSTLY CLOUDY START TO MONDAY AS THE COLD FRONT PUSHES SOUTHEAST THROUGH THE REGION. BEST CHANCE OF PRECIP WILL BE IN THE MOUNTAINS WHERE RAIN OR SNOW SHOWERS WILL LAST UNTIL AROUND NOON. FARTHER SOUTH JUST A SLIGHT CHANCE OF A SPRINKLE AS THE FRONT PUSHES THROUGH. A FEW CLOUDS WILL LINGER IN THE MOUNTAINS THROUGH THE AFTERNOON BUT EXPECT AREAS DOWNWIND TO SEE CLEARING SKIES WITH HIGHS SIMILAR TO SUNDAY BEFORE COOLER AIR MOVES IN LATER IN THE AFTERNOON. && .LONG TERM /TUESDAY THROUGH SATURDAY/... LARGE CANADIAN HIGH PRES BUILDS IN FROM THE NW MONDAY NGT AND TUESDAY THEN SETTLES OVER THE REGION TUESDAY NGT AND WEDNESDAY. THE HIGH SHIFTS TO THE E WEDNESDAY NGT AS DRY FAIR WX PERSISTS. ON THURSDAY AN INTENSE UPR LVL SYSTEM BRINGS LOW PRES INTO THE GREAT LAKES WITH A SURGE OF VERY WARM AND MOIST AIR SPREADING TOWARD THE NE ON INCREASING SOUTHERLY FLOW AT THE SFC AND SW FLOW ALOFT. THIS WILL BRING A PERIOD OF UNSETTLED WX AND PRCP...POSSIBLY DEVELOPING THURSDAY AND MAYBE CONT INTO SATURDAY...DEPENDING ON THE MODELS WHICH SHOW VARIABILITY ON TIMING WHEN THE UPR LVL RIDGE BREAKS DOWN ALLOWING THE STORM SYSTEM TO MOVE IN FROM THE WEST.. USED A BLEND OF MODELS AND MOS GUIDANCE AND HPC QPF FOR PERIODS 4 AND 5...THEN USED A SUPER BLEND OF VARIOUS MODELS AND MOS GUIDANCE BIAS CORRECTED GUIDANCE AND THE PREVIOUS FORECAST FOR DAYS 4 THRU 8. && .AVIATION /13Z SUNDAY THROUGH THURSDAY/... SHORT TERM...VFR TODAY THROUGH MONDAY. LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...VFR MONDAY NGT THRU WEDNESDAY NGT. PRCP AND INCREASING ONSHORE WINDS MAY DEVELOP THURSDAY POSSIBLY BRINGING IFR CONDITIONS. && .MARINE... SHORT TERM...SCA`S IN EFFECT THROUGH THIS EVENING FOR WINDS AND SEAS. LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...NW FLOW BEHIND COLD FRONT COULD GUST TO SCA LEVELS AND SEAS COULD STILL BE AROUND SCA LEVELS MONDAY NGT. WINDS AND SEAS THEN BELOW SCA LEVELS UNTIL SW FLOW INCREASES AHEAD OF LARGE WX SYSTEM MOVING IN FROM THE W ON THURSDAY. WINDS AND SEAS COULD REACH SCA LEVELS BY LATE THURSDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ150>154. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
408 PM EDT SUN OCT 27 2013 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 407 PM EDT SUN OCT 27 2013 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE SWINGING SE THRU NRN ONTARIO. WAA PATTERN AHEAD OF WAVE HAS PRODUCED SOME PCPN ACROSS LAKE SUPERIOR. ALTHOUGH RADAR RETURNS ALSO BLOSSOMED ACROSS MUCH OF UPPER MI...DRY AIR AT THE LOW-LEVELS HAS KEPT MOST OF THE PCPN FROM REACHING THE GROUND. AT THE SFC...ASSOCIATED COLD FRONT IS JUST NOW ENTERING NW LAKE SUPERIOR. REGIONAL RADAR IMAGERY AND SFC OBS INDICATE SOME PCPN OCCURRING IN THE VCNTY OF AND BEHIND THE FRONT. AS SHORTWAVE CONTINUES TO SWING ACROSS NRN ONTARIO...ASSOCIATED COLD FRONT WILL QUICKLY SWEEP SE ACROSS THE FCST AREA THIS EVENING. HEALTHY PRES RISES OF 6-7MB/3HR WITH FAVORABLE ALIGNMENT OF THE ISALLOBARIC WIND WITH GRADIENT WIND WILL LEAD TO GUSTY NRLY WINDS BEHIND FRONT...ESPECIALLY CLOSE TO THE LAKE SUPERIOR SHORELINE AS OVERWATER INSTABILITY STRENGTHENS (850MB TEMPS DROP FROM ROUGHLY -4/-5C AT 00Z TO -9/-11C BY 06Z). WINDS WILL LIKELY GUSTS TO AROUND 40MPH AT EXPOSED LOCATIONS. OTHERWISE...EXPECT A PERIOD OF LAKE ENHANCED PCPN ALONG COLD FRONT AS LOW-LEVEL CONVERGENCE AND DEEP LAYER FORCING FROM SHORTWAVE ACT ON OVERWATER INSTABILITY (LAKE-850MB DELTA-T AROUND 13C). AFTER A PERIOD OF SHRASN IN VCNTY OF COLD FRONT...THERE WILL BE A TRANSITION TO N TO NE FLOW LES AS LAKE-850MB DELTA-T INCREASES TO 17C OR BETTER. HOWEVER...THERE WILL BE STRONG NEGATIVES WORKING AGAINST MUCH MORE THAN LIGHT LES. FIRST...LOW-LEVEL WIND FLOW BECOMES SHARPLY ANTICYCLONIC AS SFC HIGH PRES RIDGE QUICKLY NOSES SE INTO THE UPPER LAKES...AND SECOND... INVERSION CRASHES TO 4KFT WITH DENDRITIC SNOW GROWTH TEMP ZONE REMAINING ABOVE THE SHALLOW MOIST LAYER. LIKELY POPS STILL LOOK ON TRACK FOR THE N TO NE FLOW FAVORED LOCATIONS...BUT SNOW ACCUMULATIONS SHOULD BE MINIMAL (PERHAPS AN INCH OR TWO...INCLUDING EVENING PCPN ALONG FRONT...WHERE STRONGEST UPSLOPING OCCURS SUCH AS THE HURON MTNS). LATE IN THE NIGHT/EARLY MON MORNING...THERE ARE SOME HINTS THAT MOISTENING FROM LAKE NIPIGON MAY SUPPORT A BAND OF MORE PERSISTENT LES INTO FAR WRN UPPER MI AROUND KIWD/PORCUPINE MTNS. STRONG SFC HIGH PRES RIDGE WILL BUILD SE ACROSS THE UPPER LAKES DURING MON. ALTHOUGH INVERSION BASE TEMP AROUND -10C PROVIDES A LAKE-850MB DELTA-T AROUND 17C OR SO...LES WILL STRUGGLE MON DUE TO SHARP ANTICYCLONIC FLOW AND A LOW INVERSION AT 3-4KFT. COMBINED WITH EARLY SEASON NEGATIVE EFFECTS OF DAYTIME HEATING DISRUPTING LAKE EFFECT PROCESSES...WILL STICK WITH THE IDEA OF LES ENDING EARLY IN THE AFTN. ONLY POSSIBLE EXCEPTION MAY BE FOR SOME FLURRIES TO LINGER ALONG THE TRAJECTORY DOWN WIND FROM LAKE NIPIGON. ALTHOUGH FLOW WILL BE ANTICYCLONIC...MOISTURE PICKED UP OFF LAKE SUPERIOR WILL PROBABLY LEAD TO QUITE A BIT OF STRATOCU THRU THE DAY ACROSS MUCH OF THE FCST AREA. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 332 PM EDT SUN OCT 27 2013 AT 00Z TUE...A 1035MB SFC HIGH WILL BE CENTERED OVER SRN MANITOBA AND WILL WEAKEN SLIGHTLY WHILE BECOMING CENTERED OVER THE CWA BY TUE MORNING. 850MB TEMPS WILL BE AROUND -8C AND WITH MOSTLY CLEAR SKIES (AT LEAST INLAND)...MON NIGHT LOWS WILL FALL INTO THE TEENS INLAND AND INTO THE 20S CLOSER TO LAKE SUPERIOR. THE SFC HIGH WILL MOVE TO THE NE CONUS BY 00Z WED AS AN UPPER LOW SITS OVER THE INTERMOUNTAIN WEST...WITH THE ASSOCIATED SFC LOW DEVELOPING LEEWARD OF THE CO ROCKIES. THE SLY LOW LEVEL FLOW BETWEEN THESE SYSTEMS WILL BRING A WARM FRONT TO JUST S OF THE CWA BY TUE AFTERNOON WHILE A WEAK SHORTWAVE AND LEFT EXIT REGION OF AN UPPER JET MOVE NEAR OR OVER THE CWA. THESE FORCING MECHANISMS MAY BRING SOME PRECIP TO PORTIONS OF THE CWA TUE AFTERNOON/EVENING...WITH THE BEST CHANCES OF PRECIP OVER THE SRN CWA. STILL UNCERTAIN ON IF/WHERE PRECIP WILL FALL...BUT ANY PRECIP OVER THE CWA SHOULD FALL AS MOSTLY SNOW GIVEN ONLY A SHALLOW WARM LAYER NEAR THE SFC. HIGHS ON TUE LOOK TO BE IN THE 30S TO AROUND 40. THEN THROUGH FRIDAY...THE FORECAST IS VERY DEPENDENT ON THE TRACK/STRENGTH OF THE SYSTEM OVER THE WRN CONUS EARLIER IN THE WEEK. WHILE MODELS AGREE ON GENERAL SETUP...THEY VARY SIGNIFICANTLY WITH MORE SPECIFIC AND IMPORTANT DETAILS WITH THIS TYPE OF SYSTEM. THE OVERALL IDEA IS THAT THE UPPER LOW WILL EJECT OUT INTO THE PLAINS WHILE THE ASSOCIATED UPPER TROUGH BECOMES MORE NEGATIVELY TILTED AS IT MOVES TOWARD THE CWA...THIS LEADS TO A DEEPENING OF THE SFC LOW AS IT MOVES INTO THE GREAT LAKE REGION. MODEL VARIABILITY (BOTH BETWEEN MODELS AND WITH INTER MODEL RUN TO RUN CONTINUITY) MAY SEEM SMALL WITH RELATION TO THE TRACK/INTENSITY OF THE SYSTEM...BUT WITH A FAIRLY COMPACT LOW IT WILL MAKE HUGE DIFFERENCES IN WIND/WAVE FORECASTS AND WITH PRECIP AMOUNTS/TIMING. CONFIDENCE IN THESE ASPECTS OF THE FORECAST ARE VERY LOW FOR THIS PERIOD...ESPECIALLY SINCE MODELS WILL LIKELY CHANGE SIGNIFICANTLY WITH FUTURE RUNS AS IS COMMON WITH THIS TYPE OF SYSTEM. WHAT IS MORE CERTAIN IS THAT MOST (IF NOT ALL) PRECIP WILL BE RAIN GIVEN 850MB TEMPS INCREASING TO UP TO 10C AHEAD OF THE SYSTEM...OR A BIT COLDER IF THE SYSTEM STAY S OF THE CWA BUT STILL WARM ENOUGH FOR ALMOST ALL OF THE PRECIP TO BE RAIN...AND AIR COLD ENOUGH FOR SNOW BEHIND THE SYSTEM DOES NOT ARRIVE UNTIL THE SYSTEM IS WELL DOWNSTREAM OF THE CWA. FRI NIGHT AND SAT WILL SEE INCREASING CHANCES OF PRECIP...WITH INCREASING CHANCES OF THAT PRECIP BEING ALL SNOW WITH TIME. 850MB TEMPS BEHIND THE SYSTEM WILL DECEASE FROM -2C AT 00Z SAT TO AROUND -7C BY 00Z SUN. LOW LEVEL NW WINDS WILL BE SLIGHTLY CYCLONIC TO NEUTRAL IN DIRECTIONAL CHANGE ACROSS LAKE SUPERIOR. CONDITIONS ARE MORE UNCERTAIN FOR SUN AS MODELS DIFFER MUCH MORE SIGNIFICANTLY BE LATER IN THE DAY...BUT LES SHOULD BE ABLE TO CONTINUE AT LEAST THROUGH SAT NIGHT AND INTO SUN MORNING. GIVEN UNCERTAINTY OVERALL IN EXTENDED FORECAST...JUST USED A CONSENSUS OF MODELS...ESPECIALLY FOR WED THROUGH NEXT SUN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 139 PM EDT SUN OCT 27 2013 PREVAILING VFR CONDITIONS WILL CONTINUE AT KIWD/KCMX/KSAW FOR THE NEXT FEW HRS IN DRY SW FLOW IN ADVANCE OF AN APPROACHING COLD FRONT. ONCE THE FRONT PASSES LATE THIS AFTN/EARLY EVENING...MVFR CONDITIONS WILL DEVELOP WITH UPSLOPE/MOISTER NORTHERLY FLOW AIDED BY LAKE SUPERIOR. WITH RAPID COOLING/DESTABILIZATION AND STRONG PRES RISES BEHIND FRONT...WINDS WILL BE QUITE GUSTY INTO THE 25-35KT RANGE FOR A TIME. THE HEAVIEST/MOST PERSISTENT LAKE EFFECT -SHSN ARE MORE LIKELY AT KSAW...WHERE UPSLOPE WIND COMPONENT WILL BE SHARPEST. THE VIS AT KSAW IS LIKELY TO FALL TO IFR AT TIMES UNDER SOME OF THE HEAVIER SHSN. FAVORABLE CONVERGENCE MAY RESULT IN A BAND OF HEAVIER SHSN AND POSSIBLE IFR CONDITIONS AFFECTING KIWD EARLY MON MORNING. OTHERWISE...WINDS WILL DIMINISH OVERNIGHT INTO MON MORNING AS THE PRES GRADIENT SLACKENS WITH HIGH PRES RIDGE AXIS MOVING CLOSER. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 407 PM EDT SUN OCT 27 2013 COLD FRONT WILL QUICKLY DROP SE ACROSS LAKE SUPERIOR OVER THE NEXT SEVERAL HRS. WITH STRONG HIGH PRES RIDGING SE TOWARD LAKE SUPERIOR BEHIND FRONT...HEALTHY PRES RISES OF 6-7MB/3HR WILL FOLLOW THE FRONT. COMBINED WITH AN INFLUX OF COLDER AIR RESULTING IN STRONG OVERWATER INSTABILITY...EXPECT A PERIOD OF NORTHERLY 35-40KT GALES THIS EVENING OVER MUCH OF LAKE SUPERIOR. GALES WILL BE SHORT-LIVED...ENDING AFTER MIDNIGHT AS PRES RISE MAX QUICKLY SHIFTS S OF LAKE SUPERIOR. LIGHTER WINDS...MOSTLY UNDER 20KT...SHOULD THEN PREVAIL LATER MON THRU EARLY WED AS THE HIGH PRES RIDGE SETTLES OVER THE AREA. LATE WED THRU FRI THERE IS THE POTENTIAL FOR STRONGER WINDS OF AT LEAST 15-25KT...AND POSSIBLY TO GALE FORCE...AS A LOW PRESSURE SYSTEM LIFTS FROM THE PLAINS ACROSS THE GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 11 PM THIS EVENING TO 5 AM EDT MONDAY FOR LSZ267. GALE WARNING FROM 10 PM THIS EVENING TO 5 AM EDT MONDAY FOR LSZ265-266. GALE WARNING FROM 8 PM EDT /7 PM CDT/ THIS EVENING TO 2 AM EDT /1 AM CDT/ MONDAY FOR LSZ162-263-264. GALE WARNING FROM 8 PM THIS EVENING TO 5 AM EDT MONDAY FOR LSZ248>251. GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ MONDAY FOR LSZ240>245. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
333 PM EDT SUN OCT 27 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 409 AM EDT SUN OCT 27 2013 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF CENTERED OVER HUDSON BAY DOWNSTREAM OF RDG IN THE ROCKIES. IN THE WAKE OF THE SHRTWV RESPONSIBLE FOR THE HI WINDS ON SAT...A FAIRLY PRONOUNCED SFC/UPR RDG UNDER 12HR H3 HGT RISES UP TO 200M OBSVD BTWN 12Z-24Z AT INL IS MOVING INTO THE UPR GREAT LKS. 00Z INL RAOB ALSO SHOWS RATHER DRY NEAR SFC LYR UNDER SUBSIDENCE INVRN JUST ABV H85. SO EVEN THOUGH H85 THERMAL TROF WITH TEMPS DOWN ARND -7C IS MOVING THRU THE UPR LKS...LINGERING LK EFFECT -SHRASN IN LLVL NW FLOW HAVE BECOME ISOLD AND RESTRICTED TO AREAS E OF MQT. NEXT SHRTWV EMBEDDED IN THE NW FLOW ALF ARND HUDSON BAY TROF IS NOW NEAR LK WINNIPEG. A SHARP 120KT/80KT H3/H5 JET MAX IS SUPPORTING THIS FEATURE...WITH 12HR H3 HGT FALLS UP TO 110M REPORTED AT THE PAS MANITOBA. ASSOCIATED SFC COLD FNT IS DROPPING SWD THRU MANITOBA...BUT DRYNESS OF THE AIRMASS SHOWN ON THE 00Z BISMARCK RAOB AND EVEN THE LLVLS ON THE PAS SDNG ARE LIMITING THE COVERAGE OF PCPN AHEAD OF THE SHRTWV/FNT DESPITE RATHER EXTENSIVE MID/HI CLD COVER. THERE IS MORE SN ON THE COLD SIDE OF THE BNDRY IN MANITOBA. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE TIMING/IMPACT OF SHRTWV NOW NEAR LK WINNIPEG...ESPECIALLY ON POPS AND WINDS. TODAY...ANY LINGERING LES E OF MQT WL DIMINISH THIS MRNG AS THE SFC RDG AXIS PRESSES TO THE E AND LLVL FLOW BACKS TO THE SW AHEAD OF THE APRCHG SHRTWV/COLD FNT FM THE NW. GIVEN THE DRY NATURE OF THE UPSTREAM AIRMASS TO THE W AND SW AS WELL AS LACK OF PCPN AHEAD OF THE FNT/SHRTWV ATTM...PREFER THE DRIER LOOK OF THE 00Z NAM IN REGARDS TO PCPN UNTIL THE COLD FNT REACHES THE WRN CWA LATER THIS AFTN. THE NAM HINTS MOST OF THE -SHRA AHEAD OF THE FNT WL REMAIN OUT OVER LK SUP CLOSER TO THE TRACK OF THE SHRTWV THRU ONTARIO. OTRW... SKIES WL BE MOCLDY...WITH THE BEST CHC FOR PARTIAL SUNSHINE OVER THE SCENTRAL. DESPITE THE CLD COVER...TEMPS SHOULD RECOVER INTO THE 40S PER UPSTREAM OBS MAX TEMPS ON SAT. TNGT...AS THE SHRTWV MOVES ESEWD ACRS ONTARIO AND INTO WRN QUEBEC BY 12Z MON...ATTENDANT SFC COLD FNT IS FCST TO MOVE QUICKLY THRU THE CWA THIS EVNG AND TO THE SE BY 03Z IN ADVANCE OF STRONG H925 N WINDS UP TO 35 KTS. WITH UPSLOPE N FLOW...EXPECT SOME -SHRASN TO IMPACT MAINLY THE NRN TIER ZNS AS MODELS SHOW VIGOROUS DEEP LYR QVECTOR DVGC/MID LVL DRYING FOLLOWING QUICKLY BEHIND THE FROPA. N WIND GUSTS COULD REACH 40 MPH NEAR THE EXPOSED LK SUP SHORE...ENHANCED BY MIXING IN THE VIGOROUS CAD REGIME AND FAVORABLE ALIGNMENT OF THE ISALLOBARIC WIND COMPONENT AHEAD OF TRAILING AXIS OF PRES RISES WITH THE GRADIENT FLOW. THE WINDOW OF STRONGEST WINDS SHOULD BE RATHER LIMITED AND OCCUR MAINLY BEFORE 06Z...AFTER WHICH THE GRADIENT IS FCST TO WEAKEN FOLLOWING PASSAGE OF AXIS OF PRES RISES. THIS SURGE OF COLDER AIR...WITH H85 TEMPS FALLING TO -10C BY 06Z OVER LK SUP...WL ALSO BRING THE PROSPECT OF LES IN AREAS DOWNWIND OF THE LK IN LLVL N VEERING NE FLOW. BUT FCST SDNGS SHOW INVRN BASE CRASHING TOWARD 3-4K FT AFT 06Z. THIS IN CONCERT WITH DENDRITIC SN GROWTH ZN REMAINING ABV THE SHALLOW MOIST LYR AND INCRSG ACYC LOOK TO LLVL FLOW WL LIMIT LES ACCUMS. BUT DID MAINTAIN GOING LIKELY POPS THRU 12Z MON OVER THE HIER TERRAIN OF THE NCENTRAL...WHERE THE UPSLOPE WIND COMPONENT WL BE SHARPEST. GIVEN THE VIGOROUS NEGATIVE DYNAMICS/DRYING...EXPECT SOME CLRG OVER THE SCENTRAL FOLLOWING A DRY FROPA WITH DOWNSLOPE WINDS. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 332 PM EDT SUN OCT 27 2013 AT 00Z TUE...A 1035MB SFC HIGH WILL BE CENTERED OVER SRN MANITOBA AND WILL WEAKEN SLIGHTLY WHILE BECOMING CENTERED OVER THE CWA BY TUE MORNING. 850MB TEMPS WILL BE AROUND -8C AND WITH MOSTLY CLEAR SKIES (AT LEAST INLAND)...MON NIGHT LOWS WILL FALL INTO THE TEENS INLAND AND INTO THE 20S CLOSER TO LAKE SUPERIOR. THE SFC HIGH WILL MOVE TO THE NE CONUS BY 00Z WED AS AN UPPER LOW SITS OVER THE INTERMOUNTAIN WEST...WITH THE ASSOCIATED SFC LOW DEVELOPING LEEWARD OF THE CO ROCKIES. THE SLY LOW LEVEL FLOW BETWEEN THESE SYSTEMS WILL BRING A WARM FRONT TO JUST S OF THE CWA BY TUE AFTERNOON WHILE A WEAK SHORTWAVE AND LEFT EXIT REGION OF AN UPPER JET MOVE NEAR OR OVER THE CWA. THESE FORCING MECHANISMS MAY BRING SOME PRECIP TO PORTIONS OF THE CWA TUE AFTERNOON/EVENING...WITH THE BEST CHANCES OF PRECIP OVER THE SRN CWA. STILL UNCERTAIN ON IF/WHERE PRECIP WILL FALL...BUT ANY PRECIP OVER THE CWA SHOULD FALL AS MOSTLY SNOW GIVEN ONLY A SHALLOW WARM LAYER NEAR THE SFC. HIGHS ON TUE LOOK TO BE IN THE 30S TO AROUND 40. THEN THROUGH FRIDAY...THE FORECAST IS VERY DEPENDENT ON THE TRACK/STRENGTH OF THE SYSTEM OVER THE WRN CONUS EARLIER IN THE WEEK. WHILE MODELS AGREE ON GENERAL SETUP...THEY VARY SIGNIFICANTLY WITH MORE SPECIFIC AND IMPORTANT DETAILS WITH THIS TYPE OF SYSTEM. THE OVERALL IDEA IS THAT THE UPPER LOW WILL EJECT OUT INTO THE PLAINS WHILE THE ASSOCIATED UPPER TROUGH BECOMES MORE NEGATIVELY TILTED AS IT MOVES TOWARD THE CWA...THIS LEADS TO A DEEPENING OF THE SFC LOW AS IT MOVES INTO THE GREAT LAKE REGION. MODEL VARIABILITY (BOTH BETWEEN MODELS AND WITH INTER MODEL RUN TO RUN CONTINUITY) MAY SEEM SMALL WITH RELATION TO THE TRACK/INTENSITY OF THE SYSTEM...BUT WITH A FAIRLY COMPACT LOW IT WILL MAKE HUGE DIFFERENCES IN WIND/WAVE FORECASTS AND WITH PRECIP AMOUNTS/TIMING. CONFIDENCE IN THESE ASPECTS OF THE FORECAST ARE VERY LOW FOR THIS PERIOD...ESPECIALLY SINCE MODELS WILL LIKELY CHANGE SIGNIFICANTLY WITH FUTURE RUNS AS IS COMMON WITH THIS TYPE OF SYSTEM. WHAT IS MORE CERTAIN IS THAT MOST (IF NOT ALL) PRECIP WILL BE RAIN GIVEN 850MB TEMPS INCREASING TO UP TO 10C AHEAD OF THE SYSTEM...OR A BIT COLDER IF THE SYSTEM STAY S OF THE CWA BUT STILL WARM ENOUGH FOR ALMOST ALL OF THE PRECIP TO BE RAIN...AND AIR COLD ENOUGH FOR SNOW BEHIND THE SYSTEM DOES NOT ARRIVE UNTIL THE SYSTEM IS WELL DOWNSTREAM OF THE CWA. FRI NIGHT AND SAT WILL SEE INCREASING CHANCES OF PRECIP...WITH INCREASING CHANCES OF THAT PRECIP BEING ALL SNOW WITH TIME. 850MB TEMPS BEHIND THE SYSTEM WILL DECEASE FROM -2C AT 00Z SAT TO AROUND -7C BY 00Z SUN. LOW LEVEL NW WINDS WILL BE SLIGHTLY CYCLONIC TO NEUTRAL IN DIRECTIONAL CHANGE ACROSS LAKE SUPERIOR. CONDITIONS ARE MORE UNCERTAIN FOR SUN AS MODELS DIFFER MUCH MORE SIGNIFICANTLY BE LATER IN THE DAY...BUT LES SHOULD BE ABLE TO CONTINUE AT LEAST THROUGH SAT NIGHT AND INTO SUN MORNING. GIVEN UNCERTAINTY OVERALL IN EXTENDED FORECAST...JUST USED A CONSENSUS OF MODELS...ESPECIALLY FOR WED THROUGH NEXT SUN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 139 PM EDT SUN OCT 27 2013 PREVAILING VFR CONDITIONS WILL CONTINUE AT KIWD/KCMX/KSAW FOR THE NEXT FEW HRS IN DRY SW FLOW IN ADVANCE OF AN APPROACHING COLD FRONT. ONCE THE FRONT PASSES LATE THIS AFTN/EARLY EVENING...MVFR CONDITIONS WILL DEVELOP WITH UPSLOPE/MOISTER NORTHERLY FLOW AIDED BY LAKE SUPERIOR. WITH RAPID COOLING/DESTABILIZATION AND STRONG PRES RISES BEHIND FRONT...WINDS WILL BE QUITE GUSTY INTO THE 25-35KT RANGE FOR A TIME. THE HEAVIEST/MOST PERSISTENT LAKE EFFECT -SHSN ARE MORE LIKELY AT KSAW...WHERE UPSLOPE WIND COMPONENT WILL BE SHARPEST. THE VIS AT KSAW IS LIKELY TO FALL TO IFR AT TIMES UNDER SOME OF THE HEAVIER SHSN. FAVORABLE CONVERGENCE MAY RESULT IN A BAND OF HEAVIER SHSN AND POSSIBLE IFR CONDITIONS AFFECTING KIWD EARLY MON MORNING. OTHERWISE...WINDS WILL DIMINISH OVERNIGHT INTO MON MORNING AS THE PRES GRADIENT SLACKENS WITH HIGH PRES RIDGE AXIS MOVING CLOSER. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EDT SUN OCT 27 2013 EXPECT W-SW WINDS UP TO 20-25KTS TODAY AHEAD OF AN APPROACHING COLD FRONT TO SHIFT QUICKLY TO THE N-NE BEHIND THE FRONTAL PASSAGE THIS EVENING. THE COMBINATION OF SHARPENING PRES GRADIENT AND EFFICIENT MIXING WITH CHILLY AIRMASS FLOWING OVER THE RELATIVELY WARM LAKE WATERS WILL CAUSE GALES UP TO 35-40 KTS. THE GALES WILL DIMINISH LATE TONIGHT WITH THE CLOSER APPROACH OF A TRAILING HIGH PRESSURE SYSTEM AND WEAKER PRES GRADIENT. HIGH PRESSURE AND WEAKER GRADIENT ALLOWS FOR LIGHTER WINDS...MAINLY LESS THAN 20 KTS LATER MON INTO WED. POTENTIAL FOR STRONGER WINDS...POSSIBLY TO GALE FORCE...LATER WEDNESDAY THROUGH THURSDAY AS LOW PRESSURE SYSTEM IS FORECAST TO LIFT FROM THE PLAINS ACROSS THE UPPER GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 11 PM THIS EVENING TO 5 AM EDT MONDAY FOR LSZ267. GALE WARNING FROM 10 PM THIS EVENING TO 5 AM EDT MONDAY FOR LSZ265-266. GALE WARNING FROM 8 PM EDT /7 PM CDT/ THIS EVENING TO 2 AM EDT /1 AM CDT/ MONDAY FOR LSZ162-263-264. GALE WARNING FROM 8 PM THIS EVENING TO 5 AM EDT MONDAY FOR LSZ248>251. GALE WARNING FROM 7 PM EDT /6 PM CDT/ THIS EVENING TO 2 AM EDT /1 AM CDT/ MONDAY FOR LSZ241>245. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...ROLFSON MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
140 PM EDT SUN OCT 27 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 409 AM EDT SUN OCT 27 2013 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF CENTERED OVER HUDSON BAY DOWNSTREAM OF RDG IN THE ROCKIES. IN THE WAKE OF THE SHRTWV RESPONSIBLE FOR THE HI WINDS ON SAT...A FAIRLY PRONOUNCED SFC/UPR RDG UNDER 12HR H3 HGT RISES UP TO 200M OBSVD BTWN 12Z-24Z AT INL IS MOVING INTO THE UPR GREAT LKS. 00Z INL RAOB ALSO SHOWS RATHER DRY NEAR SFC LYR UNDER SUBSIDENCE INVRN JUST ABV H85. SO EVEN THOUGH H85 THERMAL TROF WITH TEMPS DOWN ARND -7C IS MOVING THRU THE UPR LKS...LINGERING LK EFFECT -SHRASN IN LLVL NW FLOW HAVE BECOME ISOLD AND RESTRICTED TO AREAS E OF MQT. NEXT SHRTWV EMBEDDED IN THE NW FLOW ALF ARND HUDSON BAY TROF IS NOW NEAR LK WINNIPEG. A SHARP 120KT/80KT H3/H5 JET MAX IS SUPPORTING THIS FEATURE...WITH 12HR H3 HGT FALLS UP TO 110M REPORTED AT THE PAS MANITOBA. ASSOCIATED SFC COLD FNT IS DROPPING SWD THRU MANITOBA...BUT DRYNESS OF THE AIRMASS SHOWN ON THE 00Z BISMARCK RAOB AND EVEN THE LLVLS ON THE PAS SDNG ARE LIMITING THE COVERAGE OF PCPN AHEAD OF THE SHRTWV/FNT DESPITE RATHER EXTENSIVE MID/HI CLD COVER. THERE IS MORE SN ON THE COLD SIDE OF THE BNDRY IN MANITOBA. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE TIMING/IMPACT OF SHRTWV NOW NEAR LK WINNIPEG...ESPECIALLY ON POPS AND WINDS. TODAY...ANY LINGERING LES E OF MQT WL DIMINISH THIS MRNG AS THE SFC RDG AXIS PRESSES TO THE E AND LLVL FLOW BACKS TO THE SW AHEAD OF THE APRCHG SHRTWV/COLD FNT FM THE NW. GIVEN THE DRY NATURE OF THE UPSTREAM AIRMASS TO THE W AND SW AS WELL AS LACK OF PCPN AHEAD OF THE FNT/SHRTWV ATTM...PREFER THE DRIER LOOK OF THE 00Z NAM IN REGARDS TO PCPN UNTIL THE COLD FNT REACHES THE WRN CWA LATER THIS AFTN. THE NAM HINTS MOST OF THE -SHRA AHEAD OF THE FNT WL REMAIN OUT OVER LK SUP CLOSER TO THE TRACK OF THE SHRTWV THRU ONTARIO. OTRW... SKIES WL BE MOCLDY...WITH THE BEST CHC FOR PARTIAL SUNSHINE OVER THE SCENTRAL. DESPITE THE CLD COVER...TEMPS SHOULD RECOVER INTO THE 40S PER UPSTREAM OBS MAX TEMPS ON SAT. TNGT...AS THE SHRTWV MOVES ESEWD ACRS ONTARIO AND INTO WRN QUEBEC BY 12Z MON...ATTENDANT SFC COLD FNT IS FCST TO MOVE QUICKLY THRU THE CWA THIS EVNG AND TO THE SE BY 03Z IN ADVANCE OF STRONG H925 N WINDS UP TO 35 KTS. WITH UPSLOPE N FLOW...EXPECT SOME -SHRASN TO IMPACT MAINLY THE NRN TIER ZNS AS MODELS SHOW VIGOROUS DEEP LYR QVECTOR DVGC/MID LVL DRYING FOLLOWING QUICKLY BEHIND THE FROPA. N WIND GUSTS COULD REACH 40 MPH NEAR THE EXPOSED LK SUP SHORE...ENHANCED BY MIXING IN THE VIGOROUS CAD REGIME AND FAVORABLE ALIGNMENT OF THE ISALLOBARIC WIND COMPONENT AHEAD OF TRAILING AXIS OF PRES RISES WITH THE GRADIENT FLOW. THE WINDOW OF STRONGEST WINDS SHOULD BE RATHER LIMITED AND OCCUR MAINLY BEFORE 06Z...AFTER WHICH THE GRADIENT IS FCST TO WEAKEN FOLLOWING PASSAGE OF AXIS OF PRES RISES. THIS SURGE OF COLDER AIR...WITH H85 TEMPS FALLING TO -10C BY 06Z OVER LK SUP...WL ALSO BRING THE PROSPECT OF LES IN AREAS DOWNWIND OF THE LK IN LLVL N VEERING NE FLOW. BUT FCST SDNGS SHOW INVRN BASE CRASHING TOWARD 3-4K FT AFT 06Z. THIS IN CONCERT WITH DENDRITIC SN GROWTH ZN REMAINING ABV THE SHALLOW MOIST LYR AND INCRSG ACYC LOOK TO LLVL FLOW WL LIMIT LES ACCUMS. BUT DID MAINTAIN GOING LIKELY POPS THRU 12Z MON OVER THE HIER TERRAIN OF THE NCENTRAL...WHERE THE UPSLOPE WIND COMPONENT WL BE SHARPEST. GIVEN THE VIGOROUS NEGATIVE DYNAMICS/DRYING...EXPECT SOME CLRG OVER THE SCENTRAL FOLLOWING A DRY FROPA WITH DOWNSLOPE WINDS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 409 AM EDT SUN OCT 27 2013 DEEP TROUGH THAT HAS BROUGHT BELOW NORMAL TEMPERATURES AND LAKE EFFECT PRECIPITATION OVER THE GREAT LAKES RECENTLY WILL RELAX THIS WEEK AS SPLIT FLOW PATTERN DEVELOPS. GOOD AGREEMENT THAT INITIAL SALVO...IN AT LEAST A TEMPORARY PATTERN CHANGE...OCCURS ON MONDAY AS SHARP SHORTWAVE TROUGH CURRENTLY DRIVING SOUTH ACROSS BRITISH COLUMBIA DIGS TOWARD THE SOUTHWEST CONUS WHILE EXPANDING INTO FAIRLY LARGE CUTOFF UPPER TROUGH. CONFLUENT FLOW ALOFT BETWEEN THE EASING TROUGH OVER EASTERN CANADA AND MORE ZONAL FLOW OVER MUCH OF THE CONUS OUT AHEAD OF THE CUTOFF WILL RESULT IN DRY WEATHER OVER THE GREAT LAKES MONDAY AND MONDAY NIGHT AS LARGE SPRAWLING SFC HIGH PRESSURE EXPANDS FM WESTERN CANADA ACROSS THE GREAT LAKES. AS THE HIGH BUILDS IN...LK EFFECT THAT DEVELOPS TONIGHT FOR NE FLOW AREAS WILL QUICKLY DIMINISH DUE TO STRONG SUBSIDENCE AND DRYING TIED INTO THE HIGH PRESSURE...EVEN AS TEMPS AT INVERSION TOP ARE NEAR -10C AT 12Z ON MONDAY MORNING. SOUNDINGS INDICATE STRATOCU MAY LINGER FOR UPSLOPE AREAS AS HIGHER H9 MOISTURE PERSISTS...BUT EVEN THESE CLOUDS SHOULD FADE AWAY LATER MONDAY AFTN. ONCE THE DRY WEATHER DEVELOPS ON MONDAY IT SHOULD REMAIN IN PLACE INTO TUESDAY THOUGH THIS IS WHERE MODEL DIFFERENCES BEGIN TO APPEAR. PRIMARY ISSUE IS HOW QUICKLY THE MODELS BRING H3-H2 JET ENERGY AROUND THE SOUTHWEST CUTOFF LOW...IMPACTING EVENTUAL EASTWARD MOVEMENT OF THE UPPER TROUGH ACROSS THE PLAINS. RECENT RUNS OF GFS ARE QUICKER THAN ECMWF/GEM-NH. NO REAL SURPRISE THERE. WPC PREFERS THE SLOWER IDEA...WHICH MORE OFTEN THAN NOT IS WHAT VERIFIES WHEN CUTOFF TYPE LOWS EMERGE FROM THE PLAINS. ACCORDINGLY...ON TUESDAY WILL DISMISS THE FARTHER EAST H5 TROUGH/LOW-LEVEL PLAINS TROUGHING/WETTER SOLUTION OFFERED BY THE GFS AND GO WITH ECMWF IDEA. 00Z GFS TRENDED AWAY FM VERY WET 26/18Z SOLUTION...LOOKING MORE LIKE ECMWF. HOWEVER...EVEN ECMWF IDEA HOLDS SOME POTENTIAL FOR AT LEAST SCATTERED PRECIP...MOSTLY IN THE FORM OF SNOW PER 1000-850/850-700MB THICKNESSES AND EXPECTED SHALLOW WARM LAYER NEAR SFC...AS FORCING FM WEAK SHORTWAVE IN NORTHERN STREAM AND DIVERGENCE FM UPPER JET STREAK INTERACT WITH H85 FRONT/HIGHER H85-H7 RH BANKED UP JUST SOUTH OF CWA. IF THE PRECIP DOES OCCUR WOULD BE OUT OF THE AREA BY LATER TUESDAY NIGHT. ATTN BY MIDWEEK SQUARELY ON UPPER TROUGH OVER NATIONS MID SECTION AND HOW QUICKLY IT DOES MOVE EAST. RESULT HAS DIRECT BEARING ON HOW SOON SFC TROUGHING MOVES TO THE UPPER MISSISSIPPI RIVER VALLEY. EVEN THE SOMEWHAT SLOWER 00Z GFS REMAINS ON THE FAST SIDE OF THE GUIDANCE ENVELOPE. ECMWF SLOWEST WHILE THE GEM-NH IS IN BETWEEN. 12Z UKMET LOOKS SIMILAR TO ECMWF/GEM-NH AT 12Z WEDNESDAY BUT BY THURSDAY TAKES ON THE LOOK OF QUICKER GFS. SYSTEM WILL HAVE ABUNDANT MOISTURE TO WORK WITH AS PWATS INCREASE OVER 1 INCH WHICH IS OVER 200 PCT OF NORMAL FOR THIS TIME OF YEAR. DRY SLOT MAY BE AN ISSUE SOMETIME IN THERE AS WELL. STEEPER MID-LEVEL LAPSE RATES OVER 7C/KM MAY RESULT IN TSRA CHANCES TOO. LOCATION OF ANY ENHANCED PRECIP AREAS/TSRA UNCERTAIN AS IS TIMING. PRETTY CLEAR THAT UNCERTAINTY RAMPS UP ONCE FORECAST IS PAST TUESDAY...SO FOR MOST PART USED MODEL CONSENSUS FOR THE DETAILS. TRIED TO INCREASE WINDS SOME THOUGH AS THE SYSTEM MAY HAVE BOTH STRONGER WINDS AHEAD OF IT WEDNESDAY NIGHT INTO THURSDAY AND ALSO IN THE WAKE OF IT THURSDAY NIGHT INTO FRIDAY. STRONGER WIND FIELDS AND LOWER PRESSURES MAY RESULT IN ADVY LEVEL GUSTS IN PARTS OF THE CWA LATER WEDNESDAY THOUGH THURSDAY. THANKFLLY PTYPE WITH THE SYSTEM IS CLEAR CUT. POSSIBILITY OF A BIT OF A RAIN/SNOW MIX VERY EARLY WEDNESDAY...BEFORE PRECIP BECOMES ONLY RAIN LATER WEDNESDAY MORNING THROUGH THURSDAY AS H85 TEMPS SURGE TOWARD +10C AND THE LOW-LEVEL COLD AIR THAT HAS BEEN OVER THE AREA FOR A WHILE TAKES A BREAK AS 1000-850MB THICKNESSES RISE OVER 1350M. SOME POTENTIAL FOR MIXED PRECIP TO RETURN NEXT FRIDAY INTO SATURDAY IN WAKE OF THE WEDNESDAY/THURSDAY LOW PRESSURE SYSTEM. VERY UNCLEAR ON THE EXTENT OF MOISTURE OR FORCING THAT WILL BE AROUND BY THAT TIME THOUGH. CAN SORT OUT THOSE DETAILS LATER THIS WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 139 PM EDT SUN OCT 27 2013 PREVAILING VFR CONDITIONS WILL CONTINUE AT KIWD/KCMX/KSAW FOR THE NEXT FEW HRS IN DRY SW FLOW IN ADVANCE OF AN APPROACHING COLD FRONT. ONCE THE FRONT PASSES LATE THIS AFTN/EARLY EVENING...MVFR CONDITIONS WILL DEVELOP WITH UPSLOPE/MOISTER NORTHERLY FLOW AIDED BY LAKE SUPERIOR. WITH RAPID COOLING/DESTABILIZATION AND STRONG PRES RISES BEHIND FRONT...WINDS WILL BE QUITE GUSTY INTO THE 25-35KT RANGE FOR A TIME. THE HEAVIEST/MOST PERSISTENT LAKE EFFECT -SHSN ARE MORE LIKELY AT KSAW...WHERE UPSLOPE WIND COMPONENT WILL BE SHARPEST. THE VIS AT KSAW IS LIKELY TO FALL TO IFR AT TIMES UNDER SOME OF THE HEAVIER SHSN. FAVORABLE CONVERGENCE MAY RESULT IN A BAND OF HEAVIER SHSN AND POSSIBLE IFR CONDITIONS AFFECTING KIWD EARLY MON MORNING. OTHERWISE...WINDS WILL DIMINISH OVERNIGHT INTO MON MORNING AS THE PRES GRADIENT SLACKENS WITH HIGH PRES RIDGE AXIS MOVING CLOSER. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EDT SUN OCT 27 2013 EXPECT W-SW WINDS UP TO 20-25KTS TODAY AHEAD OF AN APPROACHING COLD FRONT TO SHIFT QUICKLY TO THE N-NE BEHIND THE FRONTAL PASSAGE THIS EVENING. THE COMBINATION OF SHARPENING PRES GRADIENT AND EFFICIENT MIXING WITH CHILLY AIRMASS FLOWING OVER THE RELATIVELY WARM LAKE WATERS WILL CAUSE GALES UP TO 35-40 KTS. THE GALES WILL DIMINISH LATE TONIGHT WITH THE CLOSER APPROACH OF A TRAILING HIGH PRESSURE SYSTEM AND WEAKER PRES GRADIENT. HIGH PRESSURE AND WEAKER GRADIENT ALLOWS FOR LIGHTER WINDS...MAINLY LESS THAN 20 KTS LATER MON INTO WED. POTENTIAL FOR STRONGER WINDS...POSSIBLY TO GALE FORCE...LATER WEDNESDAY THROUGH THURSDAY AS LOW PRESSURE SYSTEM IS FORECAST TO LIFT FROM THE PLAINS ACROSS THE UPPER GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 11 PM THIS EVENING TO 5 AM EDT MONDAY FOR LSZ267. GALE WARNING FROM 10 PM THIS EVENING TO 5 AM EDT MONDAY FOR LSZ265-266. GALE WARNING FROM 8 PM EDT /7 PM CDT/ THIS EVENING TO 2 AM EDT /1 AM CDT/ MONDAY FOR LSZ162-263-264. GALE WARNING FROM 8 PM THIS EVENING TO 5 AM EDT MONDAY FOR LSZ248>251. GALE WARNING FROM 7 PM EDT /6 PM CDT/ THIS EVENING TO 2 AM EDT /1 AM CDT/ MONDAY FOR LSZ241>245. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...ROLFSON MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
726 AM EDT SUN OCT 27 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 409 AM EDT SUN OCT 27 2013 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF CENTERED OVER HUDSON BAY DOWNSTREAM OF RDG IN THE ROCKIES. IN THE WAKE OF THE SHRTWV RESPONSIBLE FOR THE HI WINDS ON SAT...A FAIRLY PRONOUNCED SFC/UPR RDG UNDER 12HR H3 HGT RISES UP TO 200M OBSVD BTWN 12Z-24Z AT INL IS MOVING INTO THE UPR GREAT LKS. 00Z INL RAOB ALSO SHOWS RATHER DRY NEAR SFC LYR UNDER SUBSIDENCE INVRN JUST ABV H85. SO EVEN THOUGH H85 THERMAL TROF WITH TEMPS DOWN ARND -7C IS MOVING THRU THE UPR LKS...LINGERING LK EFFECT -SHRASN IN LLVL NW FLOW HAVE BECOME ISOLD AND RESTRICTED TO AREAS E OF MQT. NEXT SHRTWV EMBEDDED IN THE NW FLOW ALF ARND HUDSON BAY TROF IS NOW NEAR LK WINNIPEG. A SHARP 120KT/80KT H3/H5 JET MAX IS SUPPORTING THIS FEATURE...WITH 12HR H3 HGT FALLS UP TO 110M REPORTED AT THE PAS MANITOBA. ASSOCIATED SFC COLD FNT IS DROPPING SWD THRU MANITOBA...BUT DRYNESS OF THE AIRMASS SHOWN ON THE 00Z BISMARCK RAOB AND EVEN THE LLVLS ON THE PAS SDNG ARE LIMITING THE COVERAGE OF PCPN AHEAD OF THE SHRTWV/FNT DESPITE RATHER EXTENSIVE MID/HI CLD COVER. THERE IS MORE SN ON THE COLD SIDE OF THE BNDRY IN MANITOBA. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE TIMING/IMPACT OF SHRTWV NOW NEAR LK WINNIPEG...ESPECIALLY ON POPS AND WINDS. TODAY...ANY LINGERING LES E OF MQT WL DIMINISH THIS MRNG AS THE SFC RDG AXIS PRESSES TO THE E AND LLVL FLOW BACKS TO THE SW AHEAD OF THE APRCHG SHRTWV/COLD FNT FM THE NW. GIVEN THE DRY NATURE OF THE UPSTREAM AIRMASS TO THE W AND SW AS WELL AS LACK OF PCPN AHEAD OF THE FNT/SHRTWV ATTM...PREFER THE DRIER LOOK OF THE 00Z NAM IN REGARDS TO PCPN UNTIL THE COLD FNT REACHES THE WRN CWA LATER THIS AFTN. THE NAM HINTS MOST OF THE -SHRA AHEAD OF THE FNT WL REMAIN OUT OVER LK SUP CLOSER TO THE TRACK OF THE SHRTWV THRU ONTARIO. OTRW... SKIES WL BE MOCLDY...WITH THE BEST CHC FOR PARTIAL SUNSHINE OVER THE SCENTRAL. DESPITE THE CLD COVER...TEMPS SHOULD RECOVER INTO THE 40S PER UPSTREAM OBS MAX TEMPS ON SAT. TNGT...AS THE SHRTWV MOVES ESEWD ACRS ONTARIO AND INTO WRN QUEBEC BY 12Z MON...ATTENDANT SFC COLD FNT IS FCST TO MOVE QUICKLY THRU THE CWA THIS EVNG AND TO THE SE BY 03Z IN ADVANCE OF STRONG H925 N WINDS UP TO 35 KTS. WITH UPSLOPE N FLOW...EXPECT SOME -SHRASN TO IMPACT MAINLY THE NRN TIER ZNS AS MODELS SHOW VIGOROUS DEEP LYR QVECTOR DVGC/MID LVL DRYING FOLLOWING QUICKLY BEHIND THE FROPA. N WIND GUSTS COULD REACH 40 MPH NEAR THE EXPOSED LK SUP SHORE...ENHANCED BY MIXING IN THE VIGOROUS CAD REGIME AND FAVORABLE ALIGNMENT OF THE ISALLOBARIC WIND COMPONENT AHEAD OF TRAILING AXIS OF PRES RISES WITH THE GRADIENT FLOW. THE WINDOW OF STRONGEST WINDS SHOULD BE RATHER LIMITED AND OCCUR MAINLY BEFORE 06Z...AFTER WHICH THE GRADIENT IS FCST TO WEAKEN FOLLOWING PASSAGE OF AXIS OF PRES RISES. THIS SURGE OF COLDER AIR...WITH H85 TEMPS FALLING TO -10C BY 06Z OVER LK SUP...WL ALSO BRING THE PROSPECT OF LES IN AREAS DOWNWIND OF THE LK IN LLVL N VEERING NE FLOW. BUT FCST SDNGS SHOW INVRN BASE CRASHING TOWARD 3-4K FT AFT 06Z. THIS IN CONCERT WITH DENDRITIC SN GROWTH ZN REMAINING ABV THE SHALLOW MOIST LYR AND INCRSG ACYC LOOK TO LLVL FLOW WL LIMIT LES ACCUMS. BUT DID MAINTAIN GOING LIKELY POPS THRU 12Z MON OVER THE HIER TERRAIN OF THE NCENTRAL...WHERE THE UPSLOPE WIND COMPONENT WL BE SHARPEST. GIVEN THE VIGOROUS NEGATIVE DYNAMICS/DRYING...EXPECT SOME CLRG OVER THE SCENTRAL FOLLOWING A DRY FROPA WITH DOWNSLOPE WINDS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 409 AM EDT SUN OCT 27 2013 DEEP TROUGH THAT HAS BROUGHT BELOW NORMAL TEMPERATURES AND LAKE EFFECT PRECIPITATION OVER THE GREAT LAKES RECENTLY WILL RELAX THIS WEEK AS SPLIT FLOW PATTERN DEVELOPS. GOOD AGREEMENT THAT INITIAL SALVO...IN AT LEAST A TEMPORARY PATTERN CHANGE...OCCURS ON MONDAY AS SHARP SHORTWAVE TROUGH CURRENTLY DRIVING SOUTH ACROSS BRITISH COLUMBIA DIGS TOWARD THE SOUTHWEST CONUS WHILE EXPANDING INTO FAIRLY LARGE CUTOFF UPPER TROUGH. CONFLUENT FLOW ALOFT BETWEEN THE EASING TROUGH OVER EASTERN CANADA AND MORE ZONAL FLOW OVER MUCH OF THE CONUS OUT AHEAD OF THE CUTOFF WILL RESULT IN DRY WEATHER OVER THE GREAT LAKES MONDAY AND MONDAY NIGHT AS LARGE SPRAWLING SFC HIGH PRESSURE EXPANDS FM WESTERN CANADA ACROSS THE GREAT LAKES. AS THE HIGH BUILDS IN...LK EFFECT THAT DEVELOPS TONIGHT FOR NE FLOW AREAS WILL QUICKLY DIMINISH DUE TO STRONG SUBSIDENCE AND DRYING TIED INTO THE HIGH PRESSURE...EVEN AS TEMPS AT INVERSION TOP ARE NEAR -10C AT 12Z ON MONDAY MORNING. SOUNDINGS INDICATE STRATOCU MAY LINGER FOR UPSLOPE AREAS AS HIGHER H9 MOISTURE PERSISTS...BUT EVEN THESE CLOUDS SHOULD FADE AWAY LATER MONDAY AFTN. ONCE THE DRY WEATHER DEVELOPS ON MONDAY IT SHOULD REMAIN IN PLACE INTO TUESDAY THOUGH THIS IS WHERE MODEL DIFFERENCES BEGIN TO APPEAR. PRIMARY ISSUE IS HOW QUICKLY THE MODELS BRING H3-H2 JET ENERGY AROUND THE SOUTHWEST CUTOFF LOW...IMPACTING EVENTUAL EASTWARD MOVEMENT OF THE UPPER TROUGH ACROSS THE PLAINS. RECENT RUNS OF GFS ARE QUICKER THAN ECMWF/GEM-NH. NO REAL SURPRISE THERE. WPC PREFERS THE SLOWER IDEA...WHICH MORE OFTEN THAN NOT IS WHAT VERIFIES WHEN CUTOFF TYPE LOWS EMERGE FROM THE PLAINS. ACCORDINGLY...ON TUESDAY WILL DISMISS THE FARTHER EAST H5 TROUGH/LOW-LEVEL PLAINS TROUGHING/WETTER SOLUTION OFFERED BY THE GFS AND GO WITH ECMWF IDEA. 00Z GFS TRENDED AWAY FM VERY WET 26/18Z SOLUTION...LOOKING MORE LIKE ECMWF. HOWEVER...EVEN ECMWF IDEA HOLDS SOME POTENTIAL FOR AT LEAST SCATTERED PRECIP...MOSTLY IN THE FORM OF SNOW PER 1000-850/850-700MB THICKNESSES AND EXPECTED SHALLOW WARM LAYER NEAR SFC...AS FORCING FM WEAK SHORTWAVE IN NORTHERN STREAM AND DIVERGENCE FM UPPER JET STREAK INTERACT WITH H85 FRONT/HIGHER H85-H7 RH BANKED UP JUST SOUTH OF CWA. IF THE PRECIP DOES OCCUR WOULD BE OUT OF THE AREA BY LATER TUESDAY NIGHT. ATTN BY MIDWEEK SQUARELY ON UPPER TROUGH OVER NATIONS MID SECTION AND HOW QUICKLY IT DOES MOVE EAST. RESULT HAS DIRECT BEARING ON HOW SOON SFC TROUGHING MOVES TO THE UPPER MISSISSIPPI RIVER VALLEY. EVEN THE SOMEWHAT SLOWER 00Z GFS REMAINS ON THE FAST SIDE OF THE GUIDANCE ENVELOPE. ECMWF SLOWEST WHILE THE GEM-NH IS IN BETWEEN. 12Z UKMET LOOKS SIMILAR TO ECMWF/GEM-NH AT 12Z WEDNESDAY BUT BY THURSDAY TAKES ON THE LOOK OF QUICKER GFS. SYSTEM WILL HAVE ABUNDANT MOISTURE TO WORK WITH AS PWATS INCREASE OVER 1 INCH WHICH IS OVER 200 PCT OF NORMAL FOR THIS TIME OF YEAR. DRY SLOT MAY BE AN ISSUE SOMETIME IN THERE AS WELL. STEEPER MID-LEVEL LAPSE RATES OVER 7C/KM MAY RESULT IN TSRA CHANCES TOO. LOCATION OF ANY ENHANCED PRECIP AREAS/TSRA UNCERTAIN AS IS TIMING. PRETTY CLEAR THAT UNCERTAINTY RAMPS UP ONCE FORECAST IS PAST TUESDAY...SO FOR MOST PART USED MODEL CONSENSUS FOR THE DETAILS. TRIED TO INCREASE WINDS SOME THOUGH AS THE SYSTEM MAY HAVE BOTH STRONGER WINDS AHEAD OF IT WEDNESDAY NIGHT INTO THURSDAY AND ALSO IN THE WAKE OF IT THURSDAY NIGHT INTO FRIDAY. STRONGER WIND FIELDS AND LOWER PRESSURES MAY RESULT IN ADVY LEVEL GUSTS IN PARTS OF THE CWA LATER WEDNESDAY THOUGH THURSDAY. THANKFLLY PTYPE WITH THE SYSTEM IS CLEAR CUT. POSSIBILITY OF A BIT OF A RAIN/SNOW MIX VERY EARLY WEDNESDAY...BEFORE PRECIP BECOMES ONLY RAIN LATER WEDNESDAY MORNING THROUGH THURSDAY AS H85 TEMPS SURGE TOWARD +10C AND THE LOW-LEVEL COLD AIR THAT HAS BEEN OVER THE AREA FOR A WHILE TAKES A BREAK AS 1000-850MB THICKNESSES RISE OVER 1350M. SOME POTENTIAL FOR MIXED PRECIP TO RETURN NEXT FRIDAY INTO SATURDAY IN WAKE OF THE WEDNESDAY/THURSDAY LOW PRESSURE SYSTEM. VERY UNCLEAR ON THE EXTENT OF MOISTURE OR FORCING THAT WILL BE AROUND BY THAT TIME THOUGH. CAN SORT OUT THOSE DETAILS LATER THIS WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 726 AM EDT SUN OCT 27 2013 EXPECT PREDOMINANT VFR CONDITIONS AT ALL 3 TAF SITES MOST OF TODAY WITH DRY SW FLOW IN ADVANCE OF AN APRCHG COLD FNT. ONCE THE FNT PASSES LATE THIS AFTN/EARLY EVNG...MVFR CONDITIONS WL DVLP WITH UPSLOPE AND MOISTER NNW FLOW. WITH RAPID COOLING/DESTABILIZATION AND QUICKLY SHARPENING PRES GRADIENT BEHIND THE FROPA...THESE WINDS WL BE QUITE GUSTY. THE HEAVIEST/MOST PERSISTENT LK EFFECT -SHSN ARE MOST LIKELY AT SAW...WHERE UPSLOPE WIND COMPONENT WL BE SHARPEST. THE VSBY AT SAW IS LIKELY TO FALL TO IFR AT TIMES UNDER SOME OF THE HEAVIER SHSN. WINDS WL TEND TO DIMINISH LATE IN THE TAF PERIOD AS THE PRES GRADIENT SLACKENS WITH CLOSER APRCH OF HI CENTER. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EDT SUN OCT 27 2013 EXPECT W-SW WINDS UP TO 20-25KTS TODAY AHEAD OF AN APPROACHING COLD FRONT TO SHIFT QUICKLY TO THE N-NE BEHIND THE FRONTAL PASSAGE THIS EVENING. THE COMBINATION OF SHARPENING PRES GRADIENT AND EFFICIENT MIXING WITH CHILLY AIRMASS FLOWING OVER THE RELATIVELY WARM LAKE WATERS WILL CAUSE GALES UP TO 35-40 KTS. THE GALES WILL DIMINISH LATE TONIGHT WITH THE CLOSER APPROACH OF A TRAILING HIGH PRESSURE SYSTEM AND WEAKER PRES GRADIENT. HIGH PRESSURE AND WEAKER GRADIENT ALLOWS FOR LIGHTER WINDS...MAINLY LESS THAN 20 KTS LATER MON INTO WED. POTENTIAL FOR STRONGER WINDS...POSSIBLY TO GALE FORCE...LATER WEDNESDAY THROUGH THURSDAY AS LOW PRESSURE SYSTEM IS FORECAST TO LIFT FROM THE PLAINS ACROSS THE UPPER GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 11 PM THIS EVENING TO 5 AM EDT MONDAY FOR LSZ267. GALE WARNING FROM 10 PM THIS EVENING TO 5 AM EDT MONDAY FOR LSZ265-266. GALE WARNING FROM 8 PM EDT /7 PM CDT/ THIS EVENING TO 2 AM EDT /1 AM CDT/ MONDAY FOR LSZ162-263-264. GALE WARNING FROM 8 PM THIS EVENING TO 5 AM EDT MONDAY FOR LSZ248>251. GALE WARNING FROM 7 PM EDT /6 PM CDT/ THIS EVENING TO 2 AM EDT /1 AM CDT/ MONDAY FOR LSZ241>245. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...KC MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
423 AM EDT SUN OCT 27 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 409 AM EDT SUN OCT 27 2013 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF CENTERED OVER HUDSON BAY DOWNSTREAM OF RDG IN THE ROCKIES. IN THE WAKE OF THE SHRTWV RESPONSIBLE FOR THE HI WINDS ON SAT...A FAIRLY PRONOUNCED SFC/UPR RDG UNDER 12HR H3 HGT RISES UP TO 200M OBSVD BTWN 12Z-24Z AT INL IS MOVING INTO THE UPR GREAT LKS. 00Z INL RAOB ALSO SHOWS RATHER DRY NEAR SFC LYR UNDER SUBSIDENCE INVRN JUST ABV H85. SO EVEN THOUGH H85 THERMAL TROF WITH TEMPS DOWN ARND -7C IS MOVING THRU THE UPR LKS...LINGERING LK EFFECT -SHRASN IN LLVL NW FLOW HAVE BECOME ISOLD AND RESTRICTED TO AREAS E OF MQT. NEXT SHRTWV EMBEDDED IN THE NW FLOW ALF ARND HUDSON BAY TROF IS NOW NEAR LK WINNIPEG. A SHARP 120KT/80KT H3/H5 JET MAX IS SUPPORTING THIS FEATURE...WITH 12HR H3 HGT FALLS UP TO 110M REPORTED AT THE PAS MANITOBA. ASSOCIATED SFC COLD FNT IS DROPPING SWD THRU MANITOBA...BUT DRYNESS OF THE AIRMASS SHOWN ON THE 00Z BISMARCK RAOB AND EVEN THE LLVLS ON THE PAS SDNG ARE LIMITING THE COVERAGE OF PCPN AHEAD OF THE SHRTWV/FNT DESPITE RATHER EXTENSIVE MID/HI CLD COVER. THERE IS MORE SN ON THE COLD SIDE OF THE BNDRY IN MANITOBA. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE TIMING/IMPACT OF SHRTWV NOW NEAR LK WINNIPEG...ESPECIALLY ON POPS AND WINDS. TODAY...ANY LINGERING LES E OF MQT WL DIMINISH THIS MRNG AS THE SFC RDG AXIS PRESSES TO THE E AND LLVL FLOW BACKS TO THE SW AHEAD OF THE APRCHG SHRTWV/COLD FNT FM THE NW. GIVEN THE DRY NATURE OF THE UPSTREAM AIRMASS TO THE W AND SW AS WELL AS LACK OF PCPN AHEAD OF THE FNT/SHRTWV ATTM...PREFER THE DRIER LOOK OF THE 00Z NAM IN REGARDS TO PCPN UNTIL THE COLD FNT REACHES THE WRN CWA LATER THIS AFTN. THE NAM HINTS MOST OF THE -SHRA AHEAD OF THE FNT WL REMAIN OUT OVER LK SUP CLOSER TO THE TRACK OF THE SHRTWV THRU ONTARIO. OTRW... SKIES WL BE MOCLDY...WITH THE BEST CHC FOR PARTIAL SUNSHINE OVER THE SCENTRAL. DESPITE THE CLD COVER...TEMPS SHOULD RECOVER INTO THE 40S PER UPSTREAM OBS MAX TEMPS ON SAT. TNGT...AS THE SHRTWV MOVES ESEWD ACRS ONTARIO AND INTO WRN QUEBEC BY 12Z MON...ATTENDANT SFC COLD FNT IS FCST TO MOVE QUICKLY THRU THE CWA THIS EVNG AND TO THE SE BY 03Z IN ADVANCE OF STRONG H925 N WINDS UP TO 35 KTS. WITH UPSLOPE N FLOW...EXPECT SOME -SHRASN TO IMPACT MAINLY THE NRN TIER ZNS AS MODELS SHOW VIGOROUS DEEP LYR QVECTOR DVGC/MID LVL DRYING FOLLOWING QUICKLY BEHIND THE FROPA. N WIND GUSTS COULD REACH 40 MPH NEAR THE EXPOSED LK SUP SHORE...ENHANCED BY MIXING IN THE VIGOROUS CAD REGIME AND FAVORABLE ALIGNMENT OF THE ISALLOBARIC WIND COMPONENT AHEAD OF TRAILING AXIS OF PRES RISES WITH THE GRADIENT FLOW. THE WINDOW OF STRONGEST WINDS SHOULD BE RATHER LIMITED AND OCCUR MAINLY BEFORE 06Z...AFTER WHICH THE GRADIENT IS FCST TO WEAKEN FOLLOWING PASSAGE OF AXIS OF PRES RISES. THIS SURGE OF COLDER AIR...WITH H85 TEMPS FALLING TO -10C BY 06Z OVER LK SUP...WL ALSO BRING THE PROSPECT OF LES IN AREAS DOWNWIND OF THE LK IN LLVL N VEERING NE FLOW. BUT FCST SDNGS SHOW INVRN BASE CRASHING TOWARD 3-4K FT AFT 06Z. THIS IN CONCERT WITH DENDRITIC SN GROWTH ZN REMAINING ABV THE SHALLOW MOIST LYR AND INCRSG ACYC LOOK TO LLVL FLOW WL LIMIT LES ACCUMS. BUT DID MAINTAIN GOING LIKELY POPS THRU 12Z MON OVER THE HIER TERRAIN OF THE NCENTRAL...WHERE THE UPSLOPE WIND COMPONENT WL BE SHARPEST. GIVEN THE VIGOROUS NEGATIVE DYNAMICS/DRYING...EXPECT SOME CLRG OVER THE SCENTRAL FOLLOWING A DRY FROPA WITH DOWNSLOPE WINDS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 409 AM EDT SUN OCT 27 2013 DEEP TROUGH THAT HAS BROUGHT BELOW NORMAL TEMPERATURES AND LAKE EFFECT PRECIPITATION OVER THE GREAT LAKES RECENTLY WILL RELAX THIS WEEK AS SPLIT FLOW PATTERN DEVELOPS. GOOD AGREEMENT THAT INITIAL SALVO...IN AT LEAST A TEMPORARY PATTERN CHANGE...OCCURS ON MONDAY AS SHARP SHORTWAVE TROUGH CURRENTLY DRIVING SOUTH ACROSS BRITISH COLUMBIA DIGS TOWARD THE SOUTHWEST CONUS WHILE EXPANDING INTO FAIRLY LARGE CUTOFF UPPER TROUGH. CONFLUENT FLOW ALOFT BETWEEN THE EASING TROUGH OVER EASTERN CANADA AND MORE ZONAL FLOW OVER MUCH OF THE CONUS OUT AHEAD OF THE CUTOFF WILL RESULT IN DRY WEATHER OVER THE GREAT LAKES MONDAY AND MONDAY NIGHT AS LARGE SPRAWLING SFC HIGH PRESSURE EXPANDS FM WESTERN CANADA ACROSS THE GREAT LAKES. AS THE HIGH BUILDS IN...LK EFFECT THAT DEVELOPS TONIGHT FOR NE FLOW AREAS WILL QUICKLY DIMINISH DUE TO STRONG SUBSIDENCE AND DRYING TIED INTO THE HIGH PRESSURE...EVEN AS TEMPS AT INVERSION TOP ARE NEAR -10C AT 12Z ON MONDAY MORNING. SOUNDINGS INDICATE STRATOCU MAY LINGER FOR UPSLOPE AREAS AS HIGHER H9 MOISTURE PERSISTS...BUT EVEN THESE CLOUDS SHOULD FADE AWAY LATER MONDAY AFTN. ONCE THE DRY WEATHER DEVELOPS ON MONDAY IT SHOULD REMAIN IN PLACE INTO TUESDAY THOUGH THIS IS WHERE MODEL DIFFERENCES BEGIN TO APPEAR. PRIMARY ISSUE IS HOW QUICKLY THE MODELS BRING H3-H2 JET ENERGY AROUND THE SOUTHWEST CUTOFF LOW...IMPACTING EVENTUAL EASTWARD MOVEMENT OF THE UPPER TROUGH ACROSS THE PLAINS. RECENT RUNS OF GFS ARE QUICKER THAN ECMWF/GEM-NH. NO REAL SURPRISE THERE. WPC PREFERS THE SLOWER IDEA...WHICH MORE OFTEN THAN NOT IS WHAT VERIFIES WHEN CUTOFF TYPE LOWS EMERGE FROM THE PLAINS. ACCORDINGLY...ON TUESDAY WILL DISMISS THE FARTHER EAST H5 TROUGH/LOW-LEVEL PLAINS TROUGHING/WETTER SOLUTION OFFERED BY THE GFS AND GO WITH ECMWF IDEA. 00Z GFS TRENDED AWAY FM VERY WET 26/18Z SOLUTION...LOOKING MORE LIKE ECMWF. HOWEVER...EVEN ECMWF IDEA HOLDS SOME POTENTIAL FOR AT LEAST SCATTERED PRECIP...MOSTLY IN THE FORM OF SNOW PER 1000-850/850-700MB THICKNESSES AND EXPECTED SHALLOW WARM LAYER NEAR SFC...AS FORCING FM WEAK SHORTWAVE IN NORTHERN STREAM AND DIVERGENCE FM UPPER JET STREAK INTERACT WITH H85 FRONT/HIGHER H85-H7 RH BANKED UP JUST SOUTH OF CWA. IF THE PRECIP DOES OCCUR WOULD BE OUT OF THE AREA BY LATER TUESDAY NIGHT. ATTN BY MIDWEEK SQUARELY ON UPPER TROUGH OVER NATIONS MID SECTION AND HOW QUICKLY IT DOES MOVE EAST. RESULT HAS DIRECT BEARING ON HOW SOON SFC TROUGHING MOVES TO THE UPPER MISSISSIPPI RIVER VALLEY. EVEN THE SOMEWHAT SLOWER 00Z GFS REMAINS ON THE FAST SIDE OF THE GUIDANCE ENVELOPE. ECMWF SLOWEST WHILE THE GEM-NH IS IN BETWEEN. 12Z UKMET LOOKS SIMILAR TO ECMWF/GEM-NH AT 12Z WEDNESDAY BUT BY THURSDAY TAKES ON THE LOOK OF QUICKER GFS. SYSTEM WILL HAVE ABUNDANT MOISTURE TO WORK WITH AS PWATS INCREASE OVER 1 INCH WHICH IS OVER 200 PCT OF NORMAL FOR THIS TIME OF YEAR. DRY SLOT MAY BE AN ISSUE SOMETIME IN THERE AS WELL. STEEPER MID-LEVEL LAPSE RATES OVER 7C/KM MAY RESULT IN TSRA CHANCES TOO. LOCATION OF ANY ENHANCED PRECIP AREAS/TSRA UNCERTAIN AS IS TIMING. PRETTY CLEAR THAT UNCERTAINTY RAMPS UP ONCE FORECAST IS PAST TUESDAY...SO FOR MOST PART USED MODEL CONSENSUS FOR THE DETAILS. TRIED TO INCREASE WINDS SOME THOUGH AS THE SYSTEM MAY HAVE BOTH STRONGER WINDS AHEAD OF IT WEDNESDAY NIGHT INTO THURSDAY AND ALSO IN THE WAKE OF IT THURSDAY NIGHT INTO FRIDAY. STRONGER WIND FIELDS AND LOWER PRESSURES MAY RESULT IN ADVY LEVEL GUSTS IN PARTS OF THE CWA LATER WEDNESDAY THOUGH THURSDAY. THANKFLLY PTYPE WITH THE SYSTEM IS CLEAR CUT. POSSIBILITY OF A BIT OF A RAIN/SNOW MIX VERY EARLY WEDNESDAY...BEFORE PRECIP BECOMES ONLY RAIN LATER WEDNESDAY MORNING THROUGH THURSDAY AS H85 TEMPS SURGE TOWARD +10C AND THE LOW-LEVEL COLD AIR THAT HAS BEEN OVER THE AREA FOR A WHILE TAKES A BREAK AS 1000-850MB THICKNESSES RISE OVER 1350M. SOME POTENTIAL FOR MIXED PRECIP TO RETURN NEXT FRIDAY INTO SATURDAY IN WAKE OF THE WEDNESDAY/THURSDAY LOW PRESSURE SYSTEM. VERY UNCLEAR ON THE EXTENT OF MOISTURE OR FORCING THAT WILL BE AROUND BY THAT TIME THOUGH. CAN SORT OUT THOSE DETAILS LATER THIS WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 125 AM EDT SUN OCT 27 2013 SFC HIGH PRES RIDGE WILL MOVE E TO THE UPPER GREAT LAKES OVERNIGHT. PREVAILING VFR CONDITIONS WILL CONTINUE AT ALL SITES THROUGH SUN AFTERNOON. ANOTHER COLD FRONT MOVES THROUGH LATE SUN AFTERNOON AND THIS WILL BRING BACK IN LAKE EFFECT SNOW SHOWERS AND MVFR CIGS AT ALL SITES AS WINDS AGAIN GO BACK TO THE NORTH OVER LAKE SUPERIOR. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EDT SUN OCT 27 2013 EXPECT W-SW WINDS UP TO 20-25KTS TODAY AHEAD OF AN APPROACHING COLD FRONT TO SHIFT QUICKLY TO THE N-NE BEHIND THE FRONTAL PASSAGE THIS EVENING. THE COMBINATION OF SHARPENING PRES GRADIENT AND EFFICIENT MIXING WITH CHILLY AIRMASS FLOWING OVER THE RELATIVELY WARM LAKE WATERS WILL CAUSE GALES UP TO 35-40 KTS. THE GALES WILL DIMINISH LATE TONIGHT WITH THE CLOSER APPROACH OF A TRAILING HIGH PRESSURE SYSTEM AND WEAKER PRES GRADIENT. HIGH PRESSURE AND WEAKER GRADIENT ALLOWS FOR LIGHTER WINDS...MAINLY LESS THAN 20 KTS LATER MON INTO WED. POTENTIAL FOR STRONGER WINDS...POSSIBLY TO GALE FORCE...LATER WEDNESDAY THROUGH THURSDAY AS LOW PRESSURE SYSTEM IS FORECAST TO LIFT FROM THE PLAINS ACROSS THE UPPER GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 11 PM THIS EVENING TO 5 AM EDT MONDAY FOR LSZ267. GALE WARNING FROM 10 PM THIS EVENING TO 5 AM EDT MONDAY FOR LSZ265-266. GALE WARNING FROM 8 PM EDT /7 PM CDT/ THIS EVENING TO 2 AM EDT /1 AM CDT/ MONDAY FOR LSZ162-263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...07 MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
125 AM EDT SUN OCT 27 2013 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 429 PM EDT SAT OCT 26 2013 PER WATER VAPOR IMAGERY AND RUC ANALYSIS...THE VIGOROUS SHORTWAVE THAT MOVED ACROSS THE AREA LAST NIGHT IS NOW IN SRN QUEBEC. ANOTHER SHORTWAVE THAT FOLLOWED THE FIRST PASSED ACROSS THE UPPER LAKES EARLY THIS AFTN AND HAS PROVIDED A BOOST TO LAKE EFFECT PCPN. ASSOCIATED SFC LOW WITH PRIMARY SHORTWAVE IS NOW LOCATED IN SW QUEBEC. TIGHT PRES GRADIENT BTWN THE DEPARTING LOW AND HIGH PRES RIDGE OVER THE DAKOTAS IS RELAXING...AND NOW THAT THE SFC PRES RISE MAX HAS SLIPPED JUST E OF LAKE SUPERIOR...WINDS ARE DIMINISHING. OBS OVER THE LAST HR OR TWO SHOW WINDS HAVE DIMINISHED ENOUGH TO DROP ONGOING WIND ADVYS WITH THIS FCST ISSUANCE. SHORTWAVES THAT PASSED ACROSS THE AREA LAST NIGHT AND EARLIER TODAY WILL BE FOLLOWED BY ANOTHER QUICKLY DIVING SE TOWARD THE UPPER GREAT LAKES SUN AFTN. WITH QUICK MOVEMENT OF SHORTWAVES...SFC HIGH PRES RIDGE CURRENTLY OVER THE DAKOTAS WILL REACH UPPER MI TONIGHT... RESULTING IN STEADILY BACKING WINDS WHICH WILL SHIFT ONGOING LAKE EFFECT PCPN UNDER 850MB TEMPS OF -7/-8C. DURING THE OVERNIGHT...WAA WILL GET UNDERWAY OVER THE W AHEAD OF THE NEXT SHORTWAVE. ONE NEGATIVE FOR LAKE EFFECT PCPN OVER THE W IS THE NOTABLY WELL-MIXED BOUNDARY LAYER SHOWN ON FCST SOUNDINGS. AS A RESULT...NOT EXPECTING MUCH IN THE WAY OF LAKE EFFECT PCPN OVER THE W TONIGHT. WHAT PCPN THERE IS MAY END UP MOSTLY CONCENTRATED IN THE CONVERGENCE ZONE THAT DEVELOPS DUE TO LAND BREEZE ENHANCED BACKING OF LARGER SCALE WINDS. TO THE E...INVERSION IS UP AROUND 7KFT. HOWEVER...A SOMEWHAT WELL MIXED BOUNDARY LAYER...DENDRITIC SNOW GROWTH ZONE MOSTLY ABOVE THE CONVECTIVE LAYER...BACKING WINDS AND -SHRA/SN/GRAUPEL MIX AT LEAST EARLIER IN THE EVENING WILL ALL WORK TO KEEP SNOW ACCUMULATIONS MINIMAL. MAY SEE LOCALLY AN INCH OR TWO OF SNOW INLAND FROM LAKE SUPERIOR. ON SUN...SHORTWAVE WILL BE DROPPING SE TOWARD THE AREA WITH ASSOCIATED COLD FRONT PROBABLY MOVING THRU THE NW HALF OF UPPER MI MID TO LATE AFTN. AHEAD OF THE FRONT...WINDS BACKING TO THE WSW WILL BRING AN END TO ANY LINGERING LK EFFECT -SHRASN OVER THE E NEAR LAKE SUPERIOR BY AFTN. OTHERWISE...IF THERE IS ANY MORNING SUNSHINE...IT WILL GIVE WAY TO THICKENING CLOUDS. MODEST DEEP LAYER FORCING PER QVECTORS OVERTOP ADEQUATE OVERWATER INSTABILITY SUGGESTS PCPN WILL DEVELOP OR BE ENHANCED IN THE CONVERGENCE ZONE ASSOCIATED WITH COLD FRONT. AS A RESULT...EXPECT INCREASING PCPN CHANCES TO SPREAD S FROM THE KEWEENAW IN THE MORNING TO MUCH OF THE N HALF OF UPPER MI BY 00Z MON. WITH WETBULB ZERO HEIGHTS INCREASING TO GENERALLY ABOVE 1500FT...PTYPE WILL BECOME MOSTLY RAIN...BUT THERE MAY BE SOME SNOW MIXED IN OVER THE HIGHER TERRAIN. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 429 PM EDT SAT OCT 26 2013 A COLD FRONT WILL BE EXITING THE ERN CWA AT 00Z MON AS A 1040MB SFC HIGH CENTERED OVER WRN CANADA CONTINUES A QUICK TRANSIT TOWARD THE CWA. AS THE COLDER AIR AND SFC HIGH PRESSURE MOVE IN SUN NIGHT...THE PRESSURE GRADIENT WILL TIGHTEN UP...LEADING TO INCREASE N-NNE WINDS POSSIBLY LEADING TO GALES OVER LAKE SUPERIOR. 850MB TEMPS WILL DECREASE FROM AROUND -5C TO -11C BETWEEN 00Z AND 12Z MON. THIS COMBINED WITH THE N-NNE WINDS WILL BRING LAKE EFFECT AND UPSLOPE SNOW TO CORRESPONDING AREAS NEAR LAKE SUPERIOR SUN NIGHT INTO MON. ALTHOUGH FLOW WILL BE SHARPLY ANTICYCLONIC...WHICH IS NOT FAVORABLE FOR LES...THE RIGHT ENTRANCE REGION OF THE UPPER JET WILL BE OVER THE CWA SUN NIGHT AND MON...HELPING TO OFFSET THE NEGATIVE EFFECTS OF THE INCREASING HIGH PRESSURE OVER THE LAKE. COULD SEE 2-3 INCHES OF SNOW OVER THE HIGHER TERRAIN OF MARQUETTE AND WRN ALGER COUNTIES...AS WELL AS THE HIGHER TERRAIN NEAR THE PORCUPINE MOUNTAINS IN GOGEBIC AND ONTONAGON COUNTIES. THE LES WILL TAPER OFF ALMOST COMPLETELY BY MID AFTERNOON MON AS THE DRY AIR AND SUBSIDENCE OF THE SFC HIGH DOMINATE. THE SFC HIGH WILL WEAKEN TO 1033MB AS IT MOVES TO BE CENTERED OVER THE CWA BY 12Z TUE...MOVING TO THE NE CONUS BY 00Z WED WHILE LEAVING A 1026MB RIDGE OVER THE CWA. MODELS DO SHOW SOME QPF OVER OR S OF THE SRN CWA TUE INTO TUE NIGHT AS A WARM FRONT MOVES INTO OR S OF THE CWA AND WE START WARM ADVECTING. IN FACT...BY 12Z WED...850MB TEMPS INCREASE TO NEAR 0C. THESE TEMPS SHOULD RESULT IN HIGH TEMPS IN THE 30S TO AROUND 40 ON TUE AND IN THE 40S TO AROUND 50 ON WED AS 850MB TEMPS INCREASE TO UP TO 7C. ALL THIS WARM AIR IS BEING DRAW UP INTO THE CWA AHEAD OF A DEEP UPPER LOW OVER THE INTERMOUNTAIN W AND A DEVELOPING SFC LOW LEEWARD OF THE CO ROCKIES ON TUE. THERE IS SOME MODEL DISAGREEMENT ON STRENGTH/TIMING/TRACK OF THE SYSTEM AS IT MOVES INTO THE REGION...BUT OVERALL MODELS AGREE DECENTLY ON THE GENERAL PATTERN. THE UPPER LOW OPENS INTO A TROUGH AND MOVES ACROSS THE GREAT LAKES REGION EITHER FROM LATE THU/THU NIGHT (12Z/25 GFS SOLUTION) OR ON FRI (00Z/25 ECMWF SOLUTION)...BRINGING A DEEPENING SFC LOW WITH IT AS THE TROUGH BECOMES NEGATIVELY TILTED BEFORE IT MOVES INTO THE AREA. AGAIN...EXACT TRACK AND STRENGTH OF THE SYSTEM WILL MAKE A BIG DIFFERENCE IN PRECIP AMOUNTS AND ESPECIALLY WINDS...SO THOSE ARE VERY UNCERTAIN AT THIS TIME. ONE ASPECT IS MORE CERTAIN...AND SIGNIFICANT FOR THIS TIME OF YEAR AND TYPE OF EVENT. PRECIP TYPE SHOULD BE ALL RAIN AS 850MB TEMPS INCREASE TO UP TO 10C AHEAD OF THE LOW AND DO NOT FALL BELOW 0C UNTIL THE SFC LOW IS IN QUEBEC. COULD SEE LAKE EFFECT SNOW BEHIND THE SYSTEM ON FRI NIGHT/SAT AS MODELS BRING COLDER LOW LEVEL TEMPS INTO THE CWA ALONG WITH AN UPPER TROUGH. HOWEVER...MODELED 850MB TEMPS DO NOT GET THAT COLD (AROUND -6C AT THE COLDEST) SO WOULD NEED ADDITIONAL SOURCES OF ENERGY TO SUPPORT LAKE ENHANCEMENT FOR ANY MORE SIGNIFICANT SNOWFALL TO OCCUR. THIS MAY HAPPEN...BUT CONFIDENCE IS LOW THAT FAR OUT ON SMALLER SCALE DETAILS THAT WOULD BE REQUIRED. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 125 AM EDT SUN OCT 27 2013 SFC HIGH PRES RIDGE WILL MOVE E TO THE UPPER GREAT LAKES OVERNIGHT. PREVAILING VFR CONDITIONS WILL CONTINUE AT ALL SITES THROUGH SUN AFTERNOON. ANOTHER COLD FRONT MOVES THROUGH LATE SUN AFTERNOON AND THIS WILL BRING BACK IN LAKE EFFECT SNOW SHOWERS AND MVFR CIGS AT ALL SITES AS WINDS AGAIN GO BACK TO THE NORTH OVER LAKE SUPERIOR. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 429 PM EDT SAT OCT 26 2013 WITH SFC HIGH PRES RIDGE QUICKLY MOVING E INTO THE UPPER GREAT LAKES TONIGHT...LINGERING GALES OVER ERN LAKE SUPERIOR WILL END EARLY THIS EVENING. NEXT COLD FRONT WILL QUICKLY DROP SE...CROSSING LAKE SUPERIOR SUN AFTN/EVENING. WITH STRONG HIGH PRES RIDGING SE TOWARD LAKE SUPERIOR BEHIND FRONT...HEALTHY PRES RISES WILL FOLLOW THE FRONT. COMBINED WITH AN INFLUX OF COLDER AIR AND INCREASED OVERWATER INSTABILITY...THERE SHOULD BE A PERIOD OF NORTHERLY 35KT GALES SUN EVENING OVER MUCH OF LAKE SUPERIOR. THESE GALES WILL BE SHORT-LIVED...ENDING AFTER MIDNIGHT SUN NIGHT. LIGHTER WINDS... MOSTLY UNDER 20KT...SHOULD THEN PREVAIL MON-WED AS THE HIGH PRES RIDGE SETTLES OVER THE AREA. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 10 PM THIS EVENING TO 3 AM EDT MONDAY FOR LSZ265-266. GALE WARNING FROM 8 PM THIS EVENING TO 2 AM EDT MONDAY FOR LSZ263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...07 MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1048 PM CDT MON OCT 28 2013 .UPDATE... ISSUED AT 824 PM CDT MON OCT 28 2013 BAND OF SHOWERS THAT HAS DEVELOPED ON THE NOSE OF THE LLJ OVER ERN NEB IS WHAT WE ARE WAITING ON FOR PRECIP IN THE MPX AREA TONIGHT. ADJUSTED THE POPS SOME TO MORE REFLECT THE TIMING SEEN WITH THE HRRR. BEST ISENTROPIC LIFT COMES THROUGH IN THE MORNING AND BY THE AFTERNOON...WE ARE LEFT WITH NOT MUCH TO HANG OUR HATS ON FOR PRECIP GENERATION...SO DID DECREASE POPS FROM TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...HOLDING THE MAX AT 50 PERCENT AS THIS PERIOD LOOKS TO BE DOMINATED BY OCCASIONAL BOUTS OF LIGHT RAIN OR DRIZZLE. FOR P-TYPE...LOOKING AT THE NAM/RAP/HRRR...TEMPS ARE ABOUT AS COLD AS THEY ARE GOING TO GET FOR TONIGHT RIGHT NOW ACROSS SRN/SW MN SO DID UP TEMPS SOME TONIGHT...WITH TEMPS CURRENTLY FORECAST TO REMAIN BETWEEN 33 AND 37 FROM ABOUT RWF...TO THE TWIN CITIES AND DOWN TO RED WING ON SOUTH. ALSO PULLED BACK SOME ON THE FZRA MENTION HAS BOTH THE HRRR/SREF KEEP THE FZRA CONFINED TO THE BUFFALO RIDGE. ANY FZRA MENTION HAS BEEN PUSHED BACK TO SW OF AN APPLETON TO MARSHALL LINE AS A RESULT. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 315 PM CDT MON OCT 28 2013 STRONG HIGH PRESSURE... 30.70 INCHES... WAS CENTERED NEAR LAKE WINNIPEG AT MID AFTERNOON. THE HIGH STRETCHED SOUTHEAST ACROSS THE UPPER GREAT LAKES AND WAS PROVIDING THE FA WITH A DRY NORTHEAST FLOW OF AIR WITH DEW POINTS IN THE TEENS TO MIDDLE 20S. THE DRY WEATHER PATTERN OVER THE LOCAL AREA WILL GIVE WAY TONIGHT AND TUESDAY AS A SHORT WAVE... CURRENTLY OVER WYOMING... DRIVES THROUGH. LOW LEVEL WAA WAS ALREADY EVIDENT THIS AFTERNOON TO OUR WEST AND SOUTHWEST WITH ELEVATED INSTABILITY UNDERWAY. THE UPGLIDE/SATURATION AND ADIABATIC OMEGA WILL INCREASE ACROSS CENTRAL AND SOUTHERN MN IN THE 06Z-12Z TIME FRAME AND ACROSS WEST CENTRAL WI EARLY TUESDAY MORNING. ONE CONCERN IS THAT THE DETERMINISTIC SOLUTIONS TODAY PAINT A PRETTY BLEAK PICTURE WITH PRECIPITATION AMOUNTS WHILE THE WRF SOLUTIONS... ESPECIALLY LOOKING AT THE 1KM REFLECTIVITY SHOW MORE OF A LIGHT PRECIPITATION EVENT. THIS LATTER IDEA SEEMS MORE REASONABLE GIVEN THE STRONG HIGH TO OUR NORTH AND THE SHORT DURATION OF THE FORCING. AT ANY RATE... THE PRECIPITATION WILL LIKELY BEGIN AS SNOW WITH SOME FREEZING RAIN ACROSS SOUTHEAST MN AND WEST CENTRAL MN PER THE ARW/NMM. THIS IS ALSO CONSISTENT WITH THE BUFKIT NAM/GFS PROFILE DATA. THE SNOW SHOULD CHANGE TO RAIN ACROSS SOUTH CENTRAL MN BY DAYBREAK AND ACROSS THE TWIN CITIES BY MID MORNING. THE THREAT FOR SNOW WILL LINGER ACROSS CENTRAL MN AND ADJOINING AREAS OF WEST CENTRAL WI THROUGH MID AFTERNOON. BASED ON THE SATURATION AND THERMAL PROFILE... THE GREATEST THREAT FOR SOME LIGHT ICE/SNOW ACCUMULATION IS ACROSS WEST CENTRAL MN. A HUNDREDTH OR TWO ON THE ICE WITH AROUND AN INCH OF SNOW ACCUMULATION IS FORECAST. SNOW ACCUMULATION ELSEWHERE WAS A HALF INCH OR LESS... WITH THE EXCEPTION OF SOUTH CENTRAL MN... WHERE LITTLE SNOW ACCUMULATION IS EXPECTED. TEMPERATURE WISE... TRENDED DOWN ON THE LOWS OVERNIGHT ACROSS CENTRAL MN AND WEST CENTRAL WI WITH FEW CLOUDS AND QUITE DRY AIR IN PLACE EARLY ON. LITTLE CHANGE NOTED ON HIGHS FOR TUESDAY FROM THE PREVIOUS FORECAST. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 315 PM CDT MON OCT 28 2013 MODELS ARE FAIRLY CONSISTENT WITH A LULL IN PRECIPITATION FROM TUESDAY EVENING THRU WEDNESDAY MORNING AS THE MAIN WAA PATTERN SHIFTS TO THE E/NE OF THE CWA. HOWEVER...OCCASIONAL -RA/-DZ OR -FZRA/-FZDZ MAY DEVELOP IN A BROAD AREA OF LOW CLDS AS THE MAIN UPPER LOW BEGINS TO LIFT NE ACROSS THE PLAINS. THERMAL PROFILES IN THE LOWEST 0.5 KM REMAIN PROBLEMATIC WITH CHC/S OF -FZRA/-FZDZ ACROSS THE FAR NORTHERN CWA. IN ADDITION...SNOW CHC/S WILL BE LIMITED DUE TO DRY CONDS IN THE DENDRITIC SNOW GROWTH ZONE. ANOTHER ASPECT IS THERE WILL BE LITTLE IN THE WAY OF TEMPERATURE CHG FROM TUESDAY AFTN/THRU WEDNESDAY MORNING AS LITTLE MIXING IN THE BOUNDARY LAYERS OCCURS. THUS WITH TEMPS HOLDING NEAR THE FREEZING MARK ACROSS CENTRAL MN...ANY PRECIPITATION COULD FREEZE ON AREA ROADWAYS...ESPECIALLY BRIDGES AND OVERPASSES...AND LESS TRAVELED ROADS. ONCE THE UPPER LOW MOVES OUT INTO THE PLAINS...AN AREA OF LOW PRESSURE WILL FORM ALONG THE OLD FRONTAL BOUNDARY AND DEEPEN AS IT MOVES NE ACROSS THE UPPER MIDWEST. A LARGE AREA OF PRECIPITATION WILL DEVELOP ALONG AND NORTH OF THIS RAPIDLY MOVING STORM SYSTEM. THERMAL PROFILES PAST WEDNESDAY MORNING ARE WARM ENOUGH TO KEEP PRECIPITATION TYPE IN THE FORM OF RAIN...WITH EMBEDDED TSRA IN FAR SOUTHERN MN DUE TO SOME ELEVATED INSTABILITY. RESIDUAL WRAP AROUND MOISTURE ASSOCIATED WITH THE UPPER LOW WILL GENERATE SOME -RA...PERHAPS SOME -SN THURSDAY AFTN/EVENING AS THE SYSTEM SLOWLY WEAKENS AND MOVES OUT OF THE REGION. A BRIEF COOL-DOWN WILL OCCUR FRIDAY/SATURDAY...BUT ANOTHER WARM PERIOD IS EXPECTED BY NEXT WEEK ALONG WITH MORE STORM WX. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1033 PM CDT MON OCT 28 2013 LOOKING AT THE LAST FEW RUNS OF THE HRRR...ALONG WITH THE 00Z NAM...IS LOOKING LIKE TONIGHT INTO TUESDAYS PRECIP EVENT MAY TURN OUT TO BE MUCH ADO ABOUT NOTHING. DID NOT CHANGE INHERITED TAFS MUCH...OTHER THAN TO REMOVE SNOW MENTION FROM EAU. GIVEN THE WIDE RANGE OF SOLUTIONS RANGING FROM NOT MUCH HAPPENING /HRRR/ TO A GOOD AMOUNT OF PRECIP MOVING THROUGH /18Z GFS/...HAVE CONTINUED TO BE RATHER CONSERVATIVE WITH PRECIP IN TAFS. BASED ON ALL THE DRY AIR IN THE MPX 00Z SOUNDING...IT MAY BE TOUGH TO GET MUCH OF ANYTHING TO THE GROUND...SO CONTINUED TO FAVOR THE DRIER END OF THINGS RIGHT NOW. FOR CIGS...HRRR/RAP WOULD SUGGEST MVFR CIGS IN TAFS ARE WAY OVER DONE FOR TODAY OUTSIDE OF WRN MN...WITH THE RAP SHOWING MOST MPX TAFS ENJOYING VFR CONDS TUESDAY. TUESDAY NIGHT...A MORE SIGNIFICANT PUSH OF MOISTURE WILL BE ARRIVING FROM THE SOUTH...AND WITH THAT...LOOKS LIKELY THAT ALL TERMINALS WILL EVENTUALLY END UP WITH IFR OR LOWER CIGS AT SOME POINT TUESDAY NIGHT. KMSP...CONFIDENCE BEGINNING TO DECREASE IN MSP SEEING ANY PRECIP TUE MORNING. STILL LOOKS TO BE A WINDOW FROM ABOUT 12-16Z WHERE A BRIEF RA OR SN SHOWER COULD BE SEEN...BUT LATEST RUNS OF THE NAM/HRRR DO NOT LEAVE MUCH HOPE FOR THAT OCCURRING. IN ADDITION...THE RAP WOULD SAY OTHER THAN THAT 12-16Z PRECIP WINDOW...CIGS WILL BE VFR ON TUESDAY...SO THE PROGRESSION OF MVFR CIGS TO THE SW WILL HAVE TO BE WATCHED CLOSELY AS CONDITIONS MAY BE SIGNIFICANTLY BETTER THAN CURRENTLY INDICATED...UNTIL TUESDAY NIGHT AT LEAST. /OUTLOOK FOR KMSP/ WED...MVFR OR LOWER CIGS/VIS WITH RA LIKELY IN AFTN. WINDS E 10KTS. THU...MVFR/IFR CIGS WITH -RA ENDING IN MRNG. WINDS BCMG W 10-15KTS. FRI...MVFR CIGS POSSIBLE. WINDS W 15G25KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ UPDATE...MPG SHORT TERM...RAH LONG TERM...JLT AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
824 PM CDT MON OCT 28 2013 .UPDATE... ISSUED AT 824 PM CDT MON OCT 28 2013 BAND OF SHOWERS THAT HAS DEVELOPED ON THE NOSE OF THE LLJ OVER ERN NEB IS WHAT WE ARE WAITING ON FOR PRECIP IN THE MPX AREA TONIGHT. ADJUSTED THE POPS SOME TO MORE REFLECT THE TIMING SEEN WITH THE HRRR. BEST ISENTROPIC LIFT COMES THROUGH IN THE MORNING AND BY THE AFTERNOON...WE ARE LEFT WITH NOT MUCH TO HANG OUR HATS ON FOR PRECIP GENERATION...SO DID DECREASE POPS FROM TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...HOLDING THE MAX AT 50 PERCENT AS THIS PERIOD LOOKS TO BE DOMINATED BY OCCASIONAL BOUTS OF LIGHT RAIN OR DRIZZLE. FOR P-TYPE...LOOKING AT THE NAM/RAP/HRRR...TEMPS ARE ABOUT AS COLD AS THEY ARE GOING TO GET FOR TONIGHT RIGHT NOW ACROSS SRN/SW MN SO DID UP TEMPS SOME TONIGHT...WITH TEMPS CURRENTLY FORECAST TO REMAIN BETWEEN 33 AND 37 FROM ABOUT RWF...TO THE TWIN CITIES AND DOWN TO RED WING ON SOUTH. ALSO PULLED BACK SOME ON THE FZRA MENTION HAS BOTH THE HRRR/SREF KEEP THE FZRA CONFINED TO THE BUFFALO RIDGE. ANY FZRA MENTION HAS BEEN PUSHED BACK TO SW OF AN APPLETON TO MARSHALL LINE AS A RESULT. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 315 PM CDT MON OCT 28 2013 STRONG HIGH PRESSURE... 30.70 INCHES... WAS CENTERED NEAR LAKE WINNIPEG AT MID AFTERNOON. THE HIGH STRETCHED SOUTHEAST ACROSS THE UPPER GREAT LAKES AND WAS PROVIDING THE FA WITH A DRY NORTHEAST FLOW OF AIR WITH DEW POINTS IN THE TEENS TO MIDDLE 20S. THE DRY WEATHER PATTERN OVER THE LOCAL AREA WILL GIVE WAY TONIGHT AND TUESDAY AS A SHORT WAVE... CURRENTLY OVER WYOMING... DRIVES THROUGH. LOW LEVEL WAA WAS ALREADY EVIDENT THIS AFTERNOON TO OUR WEST AND SOUTHWEST WITH ELEVATED INSTABILITY UNDERWAY. THE UPGLIDE/SATURATION AND ADIABATIC OMEGA WILL INCREASE ACROSS CENTRAL AND SOUTHERN MN IN THE 06Z-12Z TIME FRAME AND ACROSS WEST CENTRAL WI EARLY TUESDAY MORNING. ONE CONCERN IS THAT THE DETERMINISTIC SOLUTIONS TODAY PAINT A PRETTY BLEAK PICTURE WITH PRECIPITATION AMOUNTS WHILE THE WRF SOLUTIONS... ESPECIALLY LOOKING AT THE 1KM REFLECTIVITY SHOW MORE OF A LIGHT PRECIPITATION EVENT. THIS LATTER IDEA SEEMS MORE REASONABLE GIVEN THE STRONG HIGH TO OUR NORTH AND THE SHORT DURATION OF THE FORCING. AT ANY RATE... THE PRECIPITATION WILL LIKELY BEGIN AS SNOW WITH SOME FREEZING RAIN ACROSS SOUTHEAST MN AND WEST CENTRAL MN PER THE ARW/NMM. THIS IS ALSO CONSISTENT WITH THE BUFKIT NAM/GFS PROFILE DATA. THE SNOW SHOULD CHANGE TO RAIN ACROSS SOUTH CENTRAL MN BY DAYBREAK AND ACROSS THE TWIN CITIES BY MID MORNING. THE THREAT FOR SNOW WILL LINGER ACROSS CENTRAL MN AND ADJOINING AREAS OF WEST CENTRAL WI THROUGH MID AFTERNOON. BASED ON THE SATURATION AND THERMAL PROFILE... THE GREATEST THREAT FOR SOME LIGHT ICE/SNOW ACCUMULATION IS ACROSS WEST CENTRAL MN. A HUNDREDTH OR TWO ON THE ICE WITH AROUND AN INCH OF SNOW ACCUMULATION IS FORECAST. SNOW ACCUMULATION ELSEWHERE WAS A HALF INCH OR LESS... WITH THE EXCEPTION OF SOUTH CENTRAL MN... WHERE LITTLE SNOW ACCUMULATION IS EXPECTED. TEMPERATURE WISE... TRENDED DOWN ON THE LOWS OVERNIGHT ACROSS CENTRAL MN AND WEST CENTRAL WI WITH FEW CLOUDS AND QUITE DRY AIR IN PLACE EARLY ON. LITTLE CHANGE NOTED ON HIGHS FOR TUESDAY FROM THE PREVIOUS FORECAST. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 315 PM CDT MON OCT 28 2013 MODELS ARE FAIRLY CONSISTENT WITH A LULL IN PRECIPITATION FROM TUESDAY EVENING THRU WEDNESDAY MORNING AS THE MAIN WAA PATTERN SHIFTS TO THE E/NE OF THE CWA. HOWEVER...OCCASIONAL -RA/-DZ OR -FZRA/-FZDZ MAY DEVELOP IN A BROAD AREA OF LOW CLDS AS THE MAIN UPPER LOW BEGINS TO LIFT NE ACROSS THE PLAINS. THERMAL PROFILES IN THE LOWEST 0.5 KM REMAIN PROBLEMATIC WITH CHC/S OF -FZRA/-FZDZ ACROSS THE FAR NORTHERN CWA. IN ADDITION...SNOW CHC/S WILL BE LIMITED DUE TO DRY CONDS IN THE DENDRITIC SNOW GROWTH ZONE. ANOTHER ASPECT IS THERE WILL BE LITTLE IN THE WAY OF TEMPERATURE CHG FROM TUESDAY AFTN/THRU WEDNESDAY MORNING AS LITTLE MIXING IN THE BOUNDARY LAYERS OCCURS. THUS WITH TEMPS HOLDING NEAR THE FREEZING MARK ACROSS CENTRAL MN...ANY PRECIPITATION COULD FREEZE ON AREA ROADWAYS...ESPECIALLY BRIDGES AND OVERPASSES...AND LESS TRAVELED ROADS. ONCE THE UPPER LOW MOVES OUT INTO THE PLAINS...AN AREA OF LOW PRESSURE WILL FORM ALONG THE OLD FRONTAL BOUNDARY AND DEEPEN AS IT MOVES NE ACROSS THE UPPER MIDWEST. A LARGE AREA OF PRECIPITATION WILL DEVELOP ALONG AND NORTH OF THIS RAPIDLY MOVING STORM SYSTEM. THERMAL PROFILES PAST WEDNESDAY MORNING ARE WARM ENOUGH TO KEEP PRECIPITATION TYPE IN THE FORM OF RAIN...WITH EMBEDDED TSRA IN FAR SOUTHERN MN DUE TO SOME ELEVATED INSTABILITY. RESIDUAL WRAP AROUND MOISTURE ASSOCIATED WITH THE UPPER LOW WILL GENERATE SOME -RA...PERHAPS SOME -SN THURSDAY AFTN/EVENING AS THE SYSTEM SLOWLY WEAKENS AND MOVES OUT OF THE REGION. A BRIEF COOL-DOWN WILL OCCUR FRIDAY/SATURDAY...BUT ANOTHER WARM PERIOD IS EXPECTED BY NEXT WEEK ALONG WITH MORE STORM WX. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 708 PM CDT MON OCT 28 2013 MAIN CONCERN THIS TAF PERIOD IS ALSO THE SOURCE OF MUCH UNCERTAINTY...THE TIMING OF ANY POTENTIAL PRECIP LATE TONIGHT INTO TUESDAY AFTERNOON. STILL SEEING THE GFS BEING RATHER GUNG-HO WITH PRECIP...WHILE THE RAP ALONG WITH THE HRRR...HOPWRF...AND OTHER HIRES MODELS ARE RATHER CONSERVATIVE WITH BOTH THE GENERATION AND AMOUNTS OF PRECIP. AT THE MOMENT...WE ARE SEEING TWO BANDS OF PRECIP ON REGIONAL RADAR...ONE FROM NRN IA BACK WNW TO SW NODAK. THIS IS MAINLY VIRGA...THOUGH HAS THROWN OUT A SPIT OR TWO OF RAIN...THIS TREND IS EXPECTED TO CONTINUE THROUGH THE NIGHT. A SECOND...MORE ROBUST BAND HAS DEVELOPED IN THE LAST COUPLE OF HOURS ACROSS ERN NEB ON THE NOSE OF THE H85 LLJ...AND THIS IS WHAT WILL LIKELY BE THE MAIN PRECIP GENERATOR. THE HRRR ALONG WITH THE ARWWRF SEEMED TO HAVE PICKED UP ON THIS BAND...AND TIMING OF THIS BAND BY THESE MODELS MATCHES UP FAIRLY WELL WITH GOING TAFS...SO DID NOT MAKE MANY CHANGES TO THE TAF FOR PRECIP TIMING. ALL THAT WAS DONE WAS TO SPEED UP START OF SNOW AT AXN. BY THE AFTERNOON... FORCING TURNS INTO MORE OF JUST BROAD AND WEAK WAA AND MID LEVEL FGEN...WHICH LIKELY MEANS RATHER DISORGANIZED BOUTS OF -RA MOVING ACROSS THE AREA. BECAUSE OF THIS...ENDED PREVAILING PRECIP AT MOST TERMINALS BY THE AFTERNOON. RAP ALONG WITH THE 18Z NAM HAVE COME IN A BIT WARMER WITH TEMPS ACROSS SRN MN TONIGHT...SO FZRA POTENTIAL IS LOOKING QUITE LOW. THIS IS SUPPORTED BY PTYPE PROBS FROM THE 15Z SREF...WHICH HAS EITHER SNOW OR RAIN...WITH FZRA PROB AT ALL MPX TERMINALS AT 0%. AS FOR CIGS...THEY WILL DROP QUICKLY TO MVFR WHEN PRECIP MOVES IN. BY THE AFTERNOON...SREF/NAM INDICATING THAT CIGS MAY BRIEFLY RISE BACK TO VFR ACROSS ERN MN AND WI...BEFORE EVERYONE HEADS TOWARD IFR TUESDAY NIGHT. KMSP...MAY SEE A FEW SPRINKLES/FLURRIES AS EARLY AS 10Z...BUT MAIN PRECIP BAND...IF THERE ENDS UP BEING ONE...STILL LOOKS TO ARRIVE AFTER 12Z /THIS WOULD BE FROM THE ACTIVITY CURRENTLY DEVELOPING OVER ERN NEB/. AT THIS POINT...HAVE BEEN SHYING AWAY FROM THE MORE AGGRESSIVE GFS AND SIDING WITH THE HIRES MODELS...WHICH DO NOT SHOW A LOT OF SUSTAINED ACTIVITY IMPACTING MSP...MORE OF JUST OCCASIONAL BOUTS OF LIGHT PRECIP. BY THE TIME PRECIP GETS HERE...SFC TEMPS WILL BE BACK ABOVE FREEZING...IF THEY EVER GET THERE IN THE FIRST PLACE...SO STILL FEEL CONFIDENT IN KEEP PRECIP EITHER RAIN OR SNOW. LOW CLOUDS WILL COME IN PRETTY QUICK WITH PRECIP...AND MAY ACTUALLY COME IN BELOW 017 FOR A TIME IN THE MORNING. EXPECT SOME IMPROVEMENT IN HEIGHTS BY THE AFTERNOON...THOUGH NOT READY TO BITE OFF ON THE NAMS IDEA OF CIGS INCREASING TO AROUND 5K FEET IN THE AFTERNOON. BY THE END OF THE TAF...ANOTHER SURGE OF LOW LEVEL MOISTURE TUESDAY NIGHT MEANS CIGS WILL BE ON A DOWNWARD TREND. /OUTLOOK FOR KMSP/ WED...MVFR OR LOWER CIGS/VIS WITH RA LIKELY IN AFTN. WINDS E 10KTS. THU...MVFR/IFR CIGS WITH -RA ENDING IN MRNG. WINDS BCMG W 10-15KTS. FRI...MVFR CIGS POSSIBLE. WINDS W 15G25KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ UPDATE...MPG SHORT TERM...RAH LONG TERM...JLT AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
709 PM CDT MON OCT 28 2013 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 315 PM CDT MON OCT 28 2013 STRONG HIGH PRESSURE... 30.70 INCHES... WAS CENTERED NEAR LAKE WINNIPEG AT MID AFTERNOON. THE HIGH STRETCHED SOUTHEAST ACROSS THE UPPER GREAT LAKES AND WAS PROVIDING THE FA WITH A DRY NORTHEAST FLOW OF AIR WITH DEW POINTS IN THE TEENS TO MIDDLE 20S. THE DRY WEATHER PATTERN OVER THE LOCAL AREA WILL GIVE WAY TONIGHT AND TUESDAY AS A SHORT WAVE... CURRENTLY OVER WYOMING... DRIVES THROUGH. LOW LEVEL WAA WAS ALREADY EVIDENT THIS AFTERNOON TO OUR WEST AND SOUTHWEST WITH ELEVATED INSTABILITY UNDERWAY. THE UPGLIDE/SATURATION AND ADIABATIC OMEGA WILL INCREASE ACROSS CENTRAL AND SOUTHERN MN IN THE 06Z-12Z TIME FRAME AND ACROSS WEST CENTRAL WI EARLY TUESDAY MORNING. ONE CONCERN IS THAT THE DETERMINISTIC SOLUTIONS TODAY PAINT A PRETTY BLEAK PICTURE WITH PRECIPITATION AMOUNTS WHILE THE WRF SOLUTIONS... ESPECIALLY LOOKING AT THE 1KM REFLECTIVITY SHOW MORE OF A LIGHT PRECIPITATION EVENT. THIS LATTER IDEA SEEMS MORE REASONABLE GIVEN THE STRONG HIGH TO OUR NORTH AND THE SHORT DURATION OF THE FORCING. AT ANY RATE... THE PRECIPITATION WILL LIKELY BEGIN AS SNOW WITH SOME FREEZING RAIN ACROSS SOUTHEAST MN AND WEST CENTRAL MN PER THE ARW/NMM. THIS IS ALSO CONSISTENT WITH THE BUFKIT NAM/GFS PROFILE DATA. THE SNOW SHOULD CHANGE TO RAIN ACROSS SOUTH CENTRAL MN BY DAYBREAK AND ACROSS THE TWIN CITIES BY MID MORNING. THE THREAT FOR SNOW WILL LINGER ACROSS CENTRAL MN AND ADJOINING AREAS OF WEST CENTRAL WI THROUGH MID AFTERNOON. BASED ON THE SATURATION AND THERMAL PROFILE... THE GREATEST THREAT FOR SOME LIGHT ICE/SNOW ACCUMULATION IS ACROSS WEST CENTRAL MN. A HUNDREDTH OR TWO ON THE ICE WITH AROUND AN INCH OF SNOW ACCUMULATION IS FORECAST. SNOW ACCUMULATION ELSEWHERE WAS A HALF INCH OR LESS... WITH THE EXCEPTION OF SOUTH CENTRAL MN... WHERE LITTLE SNOW ACCUMULATION IS EXPECTED. TEMPERATURE WISE... TRENDED DOWN ON THE LOWS OVERNIGHT ACROSS CENTRAL MN AND WEST CENTRAL WI WITH FEW CLOUDS AND QUITE DRY AIR IN PLACE EARLY ON. LITTLE CHANGE NOTED ON HIGHS FOR TUESDAY FROM THE PREVIOUS FORECAST. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 315 PM CDT MON OCT 28 2013 MODELS ARE FAIRLY CONSISTENT WITH A LULL IN PRECIPITATION FROM TUESDAY EVENING THRU WEDNESDAY MORNING AS THE MAIN WAA PATTERN SHIFTS TO THE E/NE OF THE CWA. HOWEVER...OCCASIONAL -RA/-DZ OR -FZRA/-FZDZ MAY DEVELOP IN A BROAD AREA OF LOW CLDS AS THE MAIN UPPER LOW BEGINS TO LIFT NE ACROSS THE PLAINS. THERMAL PROFILES IN THE LOWEST 0.5 KM REMAIN PROBLEMATIC WITH CHC/S OF -FZRA/-FZDZ ACROSS THE FAR NORTHERN CWA. IN ADDITION...SNOW CHC/S WILL BE LIMITED DUE TO DRY CONDS IN THE DENDRITIC SNOW GROWTH ZONE. ANOTHER ASPECT IS THERE WILL BE LITTLE IN THE WAY OF TEMPERATURE CHG FROM TUESDAY AFTN/THRU WEDNESDAY MORNING AS LITTLE MIXING IN THE BOUNDARY LAYERS OCCURS. THUS WITH TEMPS HOLDING NEAR THE FREEZING MARK ACROSS CENTRAL MN...ANY PRECIPITATION COULD FREEZE ON AREA ROADWAYS...ESPECIALLY BRIDGES AND OVERPASSES...AND LESS TRAVELED ROADS. ONCE THE UPPER LOW MOVES OUT INTO THE PLAINS...AN AREA OF LOW PRESSURE WILL FORM ALONG THE OLD FRONTAL BOUNDARY AND DEEPEN AS IT MOVES NE ACROSS THE UPPER MIDWEST. A LARGE AREA OF PRECIPITATION WILL DEVELOP ALONG AND NORTH OF THIS RAPIDLY MOVING STORM SYSTEM. THERMAL PROFILES PAST WEDNESDAY MORNING ARE WARM ENOUGH TO KEEP PRECIPITATION TYPE IN THE FORM OF RAIN...WITH EMBEDDED TSRA IN FAR SOUTHERN MN DUE TO SOME ELEVATED INSTABILITY. RESIDUAL WRAP AROUND MOISTURE ASSOCIATED WITH THE UPPER LOW WILL GENERATE SOME -RA...PERHAPS SOME -SN THURSDAY AFTN/EVENING AS THE SYSTEM SLOWLY WEAKENS AND MOVES OUT OF THE REGION. A BRIEF COOL-DOWN WILL OCCUR FRIDAY/SATURDAY...BUT ANOTHER WARM PERIOD IS EXPECTED BY NEXT WEEK ALONG WITH MORE STORM WX. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 708 PM CDT MON OCT 28 2013 MAIN CONCERN THIS TAF PERIOD IS ALSO THE SOURCE OF MUCH UNCERTAINTY...THE TIMING OF ANY POTENTIAL PRECIP LATE TONIGHT INTO TUESDAY AFTERNOON. STILL SEEING THE GFS BEING RATHER GUNG-HO WITH PRECIP...WHILE THE RAP ALONG WITH THE HRRR...HOPWRF...AND OTHER HIRES MODELS ARE RATHER CONSERVATIVE WITH BOTH THE GENERATION AND AMOUNTS OF PRECIP. AT THE MOMENT...WE ARE SEEING TWO BANDS OF PRECIP ON REGIONAL RADAR...ONE FROM NRN IA BACK WNW TO SW NODAK. THIS IS MAINLY VIRGA...THOUGH HAS THROWN OUT A SPIT OR TWO OF RAIN...THIS TREND IS EXPECTED TO CONTINUE THROUGH THE NIGHT. A SECOND...MORE ROBUST BAND HAS DEVELOPED IN THE LAST COUPLE OF HOURS ACROSS ERN NEB ON THE NOSE OF THE H85 LLJ...AND THIS IS WHAT WILL LIKELY BE THE MAIN PRECIP GENERATOR. THE HRRR ALONG WITH THE ARWWRF SEEMED TO HAVE PICKED UP ON THIS BAND...AND TIMING OF THIS BAND BY THESE MODELS MATCHES UP FAIRLY WELL WITH GOING TAFS...SO DID NOT MAKE MANY CHANGES TO THE TAF FOR PRECIP TIMING. ALL THAT WAS DONE WAS TO SPEED UP START OF SNOW AT AXN. BY THE AFTERNOON... FORCING TURNS INTO MORE OF JUST BROAD AND WEAK WAA AND MID LEVEL FGEN...WHICH LIKELY MEANS RATHER DISORGANIZED BOUTS OF -RA MOVING ACROSS THE AREA. BECAUSE OF THIS...ENDED PREVAILING PRECIP AT MOST TERMINALS BY THE AFTERNOON. RAP ALONG WITH THE 18Z NAM HAVE COME IN A BIT WARMER WITH TEMPS ACROSS SRN MN TONIGHT...SO FZRA POTENTIAL IS LOOKING QUITE LOW. THIS IS SUPPORTED BY PTYPE PROBS FROM THE 15Z SREF...WHICH HAS EITHER SNOW OR RAIN...WITH FZRA PROB AT ALL MPX TERMINALS AT 0%. AS FOR CIGS...THEY WILL DROP QUICKLY TO MVFR WHEN PRECIP MOVES IN. BY THE AFTERNOON...SREF/NAM INDICATING THAT CIGS MAY BRIEFLY RISE BACK TO VFR ACROSS ERN MN AND WI...BEFORE EVERYONE HEADS TOWARD IFR TUESDAY NIGHT. KMSP...MAY SEE A FEW SPRINKLES/FLURRIES AS EARLY AS 10Z...BUT MAIN PRECIP BAND...IF THERE ENDS UP BEING ONE...STILL LOOKS TO ARRIVE AFTER 12Z /THIS WOULD BE FROM THE ACTIVITY CURRENTLY DEVELOPING OVER ERN NEB/. AT THIS POINT...HAVE BEEN SHYING AWAY FROM THE MORE AGGRESSIVE GFS AND SIDING WITH THE HIRES MODELS...WHICH DO NOT SHOW A LOT OF SUSTAINED ACTIVITY IMPACTING MSP...MORE OF JUST OCCASIONAL BOUTS OF LIGHT PRECIP. BY THE TIME PRECIP GETS HERE...SFC TEMPS WILL BE BACK ABOVE FREEZING...IF THEY EVER GET THERE IN THE FIRST PLACE...SO STILL FEEL CONFIDENT IN KEEP PRECIP EITHER RAIN OR SNOW. LOW CLOUDS WILL COME IN PRETTY QUICK WITH PRECIP...AND MAY ACTUALLY COME IN BELOW 017 FOR A TIME IN THE MORNING. EXPECT SOME IMPROVEMENT IN HEIGHTS BY THE AFTERNOON...THOUGH NOT READY TO BITE OFF ON THE NAMS IDEA OF CIGS INCREASING TO AROUND 5K FEET IN THE AFTERNOON. BY THE END OF THE TAF...ANOTHER SURGE OF LOW LEVEL MOISTURE TUESDAY NIGHT MEANS CIGS WILL BE ON A DOWNWARD TREND. /OUTLOOK FOR KMSP/ WED...MVFR OR LOWER CIGS/VIS WITH RA LIKELY IN AFTN. WINDS E 10KTS. THU...MVFR/IFR CIGS WITH -RA ENDING IN MRNG. WINDS BCMG W 10-15KTS. FRI...MVFR CIGS POSSIBLE. WINDS W 15G25KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...RAH LONG TERM...JLT AVIATION...MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
311 PM CDT SUN OCT 27 2013 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 310 PM CDT SUN OCT 27 2013 CURRENT VISIBLE SAT IMAGERY AND SFC OBS SHOW A WELL DEFINED COLD FRONT THAT HAS BEEN QUICKLY SWEEPING ACROSS THE NORTHLAND TODAY. AT 300 PM THE FRONT WAS POSITIONED FROM THUNDER BAY ONTARIO...SOUTHWEST OVER LAKE SUPERIOR AND ACROSS NEWEST WISCONSIN. BEHIND THE FRONT...STRONG CAA HAS RESULTED IN GUSTY NORTH WINDS AND CLOUDS. AS THE COLD FRONT CONTINUES TO PUSH SOUTH OUT OF THE REGION OVERNIGHT...IT WILL BE REPLACED BY A RIDGE OF CANADIAN HIGH PRESSURE BUILDING OVER THE BORDERLAND. MAIN STORY OVERNIGHT WILL BE NE WINDS OF 20-30 KT DEVELOPING OVER LAKE SUPERIOR IN RESPONSE TO THE STRENGTHENING PRESSURE GRADIENT AND COLD AIR MASS. THE NORTHEAST TO NORTH TRAJECTORIES WOULD FAVOR ANY LAKE ENHANCED SNOW SHOWERS TONIGHT FROM THE WESTERN TIP OF LAKE SUPERIOR...EAST ACROSS NORTHERN WISCONSIN. HOWEVER...DUE TO MARGINAL DELTA-T VALUES AND SIGNIFICANT PUSH OF DRY AIR LATE TONIGHT...ANY SNOW ACCUMULATION OVERNIGHT WILL BE MARGINAL. THE BEST CHANCE TO SEE ISOLD ONE INCH AMOUNTS THROUGH MONDAY MORNING WILL BE IN THE ELEVATED TERRAIN OF ASHLAND/IRON COUNTIES...ALONG THE GOGEBIC RANGE...WHERE CONDITIONS REMAIN FAVORABLE THE LONGEST. TEMPERATURES OVERNIGHT WILL BE GREATLY DEPENDENT ON SKY COVER AND TIMING OF CLEARING ACROSS THE NORTHERN ZONES. HAVE KEPT LOWS NEAR LATEST GUIDANCE VALUES. HOWEVER...IF SKIES CLEAR OUT BY MIDNIGHT TEMPERATURES WILL HAVE THE POTENTIAL TO FALL QUITE LOW AS DEW POINTS IN THE TEENS ARE OBSERVED UPSTREAM. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 310 PM CDT SUN OCT 27 2013 HIGH PRESSURE WILL KEEP THE NORTHLAND DRY MONDAY NIGHT...WITH CHANCES FOR LES LOW. THERE WILL BE AN ONSHORE FLOW OVER PORTIONS OF THE NEAR SHORE WATERS...INITIALLY ALONG THE SOUTH SHORE INTO THE TWIN PORTS...THEN ALONG PORTIONS OF THE NORTH SHORE LATE MONDAY NIGHT AS LOW LEVEL WINDS VEER. THE AIRMASS IS QUITE DRY THOUGH...WITH 850-700MB RH FIELDS MOSTLY BELOW 15 PERCENT...SO WE KEPT THE FORECAST DRY. WEAK WAA/FGEN WILL IMPACT PORTIONS OF THE NORTHLAND TUESDAY...MAINLY SOUTHERN AREAS. THERE WILL BE A CHANCE FOR SOME LIGHT PRECIP...WHICH SHOULD START AS MAINLY LIGHT SNOW/FLURRIES...THEN AS TEMPS WARM TRANSITION TO A RAIN/SNOW MIX. AMOUNTS LOOK TO BE RATHER LIGHT...AND WE ONLY HAVE LOW POPS. EMPHASIS SHIFTS TO AN APPROACHING LOW PRESSURE SYSTEM FOR THAT WILL IMPACT THE REGION WEDNESDAY INTO THURSDAY NIGHT. THE MODELS ARE IN GENERAL AGREEMENT...BUT DO SHOW SOME TIMING/STRENGTH DIFFERENCES. THE ECMWF IS SLOWEST BRINGING IN PRECIPITATION ON WEDNESDAY...AND HAS SOME SUPPORT FROM THE GEM. WE LEANED TOWARD THE FASTER NAM/GFS ON WEDNESDAY. THERE MAY BE A MIX OF PRECIP INITIALLY OVER NORTHERN AREAS WEDNESDAY...BUT THERE IS PLENTY OF WARM AIR MOVING IN THAT WILL SWITCH IT TO ALL RAIN DURING THE AFTERNOON. THE LOW IS EXPECTED TO MOVE INTO WESTERN WISCONSIN WEDNESDAY NIGHT...THEN CONTINUE TOWARD LAKE SUPERIOR THURSDAY. THE GEM/ECMWF ARE IN MUCH BETTER AGREEMENT WITH A SLOWER LOW MOVEMENT WEDNESDAY NIGHT-THURSDAY. TEMPERATURES LOOK WARM ENOUGH FOR MOSTLY RAIN UNTIL THURSDAY NIGHT WHEN SOME COLDER AIR WILL BRING A CHANCE FOR SNOW OR A MIX OVER NORTHEAST MINNESOTA. AN UPPER TROUGH WILL REMAIN OVER THE NORTHLAND FRIDAY INTO FRIDAY NIGHT WITH SOME LINGERING LIGHT PRECIP POSSIBLE. SOME HEAVIER RAIN/SNOW SHOWERS WILL BE POSSIBLE ALONG PORTIONS OF THE SOUTH SHORE WHICH WILL SEE NORTHERLY WINDS AND COLD LOW LEVEL TEMPERATURES. EXPECT HIGHS TUESDAY IN THE MID TO UPPER THIRTIES TO WARM INTO THE FORTIES ON WED-THU-FRI. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1241 PM CDT SUN OCT 27 2013 A COLD FRONT WAS MOVING THROUGH THE NORTHLAND...WITH WINDS SWITCHING TO THE NORTHWEST BEHIND IT. THIS HAS ALREADY OCCURRED OVER MUCH OF NORTHEAST MINNESOTA. WINDS WILL TURN TO NORTH...THEN NORTHEAST AS THE AFTERNOON/EVENING PROGRESS. MVFR CEILINGS WERE DEVELOPING OVER NORTHERN MINNESOTA...AND THEY SHOULD CONTINUE TO MOVE SOUTH THROUGH THE AFTERNOON/EARLY EVENING. GUIDANCE HAS NOT DONE A PARTICULARLY GOOD JOB DEPICTING THESE CEILINGS. THE RAP WAS DOING THE BEST JOB AT THIS TIME...AND WE USED IT FOR TIMING. WE MAY SEE BASES RISE THIS AFTERNOON/EVENING TO LOW VFR HIGH MVFR. WE DID TRANSITION TO VFR TONIGHT...BUT CONFIDENCE IS LOWER THAN AVERAGE. THERE ARE MORE MVFR CEILINGS WELL NORTH INTO MANITOBA/NORTHWEST ONTARIO THAT COULD IMPACT THE AREA LATER TONIGHT. && .PRELIMINARY POINT TEMPS/POPS... DLH 28 37 21 36 / 20 10 10 20 INL 14 31 14 34 / 10 0 0 0 BRD 23 37 23 36 / 10 0 0 40 HYR 27 38 22 38 / 30 20 0 40 ASX 32 37 21 39 / 40 30 10 20 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL NOON CDT MONDAY FOR LSZ121-146>148. SMALL CRAFT ADVISORY UNTIL 10 AM CDT MONDAY FOR LSZ140>145. && $$ SHORT TERM...GRANING LONG TERM...MELDE AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1241 PM CDT SUN OCT 27 2013 .UPDATE... ISSUED AT 1145 AM CDT SUN OCT 27 2013 BASED ON CURRENT CANADIAN RADAR IMAGERY AND SFC OBSERVATIONS UPSTREAM HAVE BROUGHT IN MENTION OF PATCHY DRIZZLE/FLURRIES TO NORTHERN HALF OF CWA LATE THIS AFTERNOON WITH COLD FRONTAL PASSAGE. LATEST DLHWRF/HRRR/4KM WRF ALL SUGGEST VERY LIGHT ISOLD PRECIP ACCOMPANIES THE LOW CLOUDS SEEN ON VIS SAT IMAGERY ADVANCING INTO THE BORDERLAND. UPDATE ISSUED AT 659 AM CDT SUN OCT 27 2013 UPDATED FOR NEW AVIATION DISCUSSION BELOW. && .SYNOPSIS... ISSUED AT 346 AM CDT SUN OCT 27 2013 A NICE CLIPPER SYSTEM IS POISED TO MOVE THROUGH THE FORECAST AREA TODAY. THERE IS A POTENT SURFACE LOW JUST SOUTH OF WINNIPEG MANITOBA WITH A TRAILING COLD FRONT EXTENDING JUST NORTH OF THE CANADIAN/U.S. BORDER. A WARM FRONT IS EXTENDING DOWN INTO EASTERN NORTH DAKOTA. AN AREA OF SNOW IS AFFECTING SOUTHWEST ONTARIO THIS MORNING...WHICH IS MOVING IN AN EAST-SOUTHEAST DIRECTION. && .SHORT TERM...(TODAY...TONIGHT AND MONDAY) ISSUED AT 346 AM CDT SUN OCT 27 2013 THE CLIPPER SYSTEM WILL MOVE THROUGH THE AREA TODAY...BRINGING A COLD FRONT ACROSS DURING THE DAY. AHEAD OF THE COLD FRONT IT WILL BE RELATIVELY MILD WITH HIGHS RISING TO AROUND 40 ALONG THE BORDERLAND...TO THE UPPER 40S TO LOW 50S ACROSS THE SOUTHERN COUNTIES. THE WARM AIR ADVECTION WING OF PRECIPITATION NOW OVER SOUTHWEST ONTARIO IS GOING TO MAINLY STAY NORTH OF THE FORECAST AREA...BUT DO EXPECT AT LEAST A SHORT PERIOD OF LIGHT RAIN/SNOW OVER THE TIP OF THE ARROWHEAD THIS MORNING AND EARLY AFTERNOON BEFORE IT MOVES OFF TO THE EAST. WINDS WILL SWITCH TO NORTHWEST THIS AFTERNOON BEHIND THE FRONT...AND THEN AROUND TO NORTH BY THIS EVENING. WITH LAKE SURFACE TEMPERATURES STILL IN THE MID 40S...EXPECT THAT WHILE WE STILL HAVE MOISTURE AROUND THE AREA ASSOCIATED WITH THE CLIPPER SOME LAKE EFFECT BANDS ARE GOING TO SET UP BEGINNING LATE THIS AFTERNOON AND EARLY EVENING...AND LINGER OVERNIGHT AND INTO MONDAY MORNING BEFORE DISSIPATING AS DRIER AIR MOVES INTO THE AREA. THIS IS LIKELY TO HAPPEN EVEN AS PRECIPITATION SHUTS OFF OVER THE REMAINDER OF THE FORECAST AREA. MIN TEMPS TONIGHT TO DROP OFF AFTER CLOUD COVER MOVES SOUTH TO OVER NORTHWEST WISCONSIN...AND HAVE MINS IN THE TEENS NORTH TO MID TO UPPER 20S SOUTH. COLD...DRY AIR MOVING IN FROM THE NORTH ON MONDAY WILL EVENTUALLY SHUT OFF THE LAKE EFFECT MECHANISM...AND ALLOWING SKIES TO CLEAR OFF FOR MOST OF THE DAY. HIGHS ARE LIKELY TO ONLY GET INTO THE 30S THOUGH...AFTER SUCH A COLD START TO THE MORNING. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 346 AM CDT SUN OCT 27 2013 A CONVERGENT UPPER LEVEL FLOW WILL DEVELOP MONDAY NIGHT...WITH UPPER LEVEL TROUGHING AND NW FLOW ACROSS OUR AREA...AND UPPER LEVEL RIDGING PUSHING INTO THE NORTHERN PLAINS. BY TUESDAY AND TUESDAY NIGHT...WE WILL HAVE TRANSITIONED INTO GENERAL UPPER LEVEL RIDGING...WITH MOISTURE ADVANCING NORTHWARD INTO THE REGION TUESDAY AND TUESDAY NIGHT. WE ARE LOOKING AT GENERALLY LIGHT QPF...MAINLY ACROSS THE SOUTH THROUGH TUESDAY NIGHT. THE MODELS HAVE CONSISTENTLY HAD A TOUGH TIME HANDLING THE EVOLUTION OF THE MAJOR SYSTEM EXPECTED TO PUSH ACROSS THE AREA FROM WEDNESDAY INTO WEDNESDAY NIGHT. WHILE THE STRENGTH OF THE SURFACE LOW AND THE POSITION OF THE TRACK OF THE LOW CHANGE FROM RUN TO RUN AND MODEL TO MODEL...ONE THING REMAINS THE SAME THOUGH. THAT IS THE EXPECTED WIDESPREAD PRECIPITATION ON WEDNESDAY NIGHT. IT LOOKS AS THOUGH MUCH OF THE PRECIPITATION WILL BE IN THE FORM OF RAIN DURING THAT TIME FRAME. THE MAIN PUSH WILL GRADUALLY LIFT TO THE NORTH AND EAST OF THE REGION BY THU...LEAVING US WITH MID RANGE POPS DUE TO WRAP AROUND PCPN. AFTER THIS SYSTEM MOVES THROUGH...WE ARE BACK TO AN UPPER LEVEL NW FLOW SCENARIO...WITH SHORTWAVES DROPPING SE INTO THE GREAT LAKES REGION. WILL CARRY SOME SMALL POPS INTO THE FIRST PART OF THE WEEKEND. HIGHS WILL LARGELY BE IN THE 40S...WITH SOME 30S AT TIMES IN THE NORTH. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1241 PM CDT SUN OCT 27 2013 A COLD FRONT WAS MOVING THROUGH THE NORTHLAND...WITH WINDS SWITCHING TO THE NORTHWEST BEHIND IT. THIS HAS ALREADY OCCURRED OVER MUCH OF NORTHEAST MINNESOTA. WINDS WILL TURN TO NORTH...THEN NORTHEAST AS THE AFTERNOON/EVENING PROGRESS. MVFR CEILINGS WERE DEVELOPING OVER NORTHERN MINNESOTA...AND THEY SHOULD CONTINUE TO MOVE SOUTH THROUGH THE AFTERNOON/EARLY EVENING. GUIDANCE HAS NOT DONE A PARTICULARLY GOOD JOB DEPICTING THESE CEILINGS. THE RAP WAS DOING THE BEST JOB AT THIS TIME...AND WE USED IT FOR TIMING. WE MAY SEE BASES RISE THIS AFTERNOON/EVENING TO LOW VFR HIGH MVFR. WE DID TRANSITION TO VFR TONIGHT...BUT CONFIDENCE IS LOWER THAN AVERAGE. THERE ARE MORE MVFR CEILINGS WELL NORTH INTO MANITOBA/NORTHWEST ONTARIO THAT COULD IMPACT THE AREA LATER TONIGHT. && .PRELIMINARY POINT TEMPS/POPS... DLH 45 26 36 21 / 10 20 0 10 INL 40 13 32 13 / 20 10 0 0 BRD 49 24 37 23 / 0 10 0 0 HYR 50 26 39 22 / 10 20 10 0 ASX 49 31 37 21 / 10 50 20 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO NOON CDT MONDAY FOR LSZ121-146>148. SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM CDT MONDAY FOR LSZ140>145. && $$ UPDATE...GRANING SYNOPSIS...LE SHORT TERM...LE LONG TERM...DAP AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
724 PM EDT MON OCT 28 2013 .SYNOPSIS... A WARMING TREND IS EXPECTED IN THE DAYS AHEAD WITH TEMPERATURES RUNNING ABOVE NORMAL TUESDAY THROUGH THE UPCOMING WEEK. A COLD FRONT WILL BRING UNSETTLED WEATHER FRIDAY AND SATURDAY FOLLOWED WITH COLDER AIR INTO THE REGION SUNDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 700 PM MONDAY...THE WEAKENING S/W TROF ALOFT WILL FURTHER WEAKEN AS IT PUSHES ACROSS THE FA AND OFFSHORE DURING THIS EVENING...WITH VARIOUS MODELS IN AGREEMENT. HAVE SCALED BACK POPS TO NO CHANCE FOR THE OVERNIGHT PERIOD...WITH THE BEST FORCING TO OCCUR OVER ADJACENT ATL WATERS EARLY THIS EVENING B4 SLIDING OFFSHORE. LATEST IR...THE 11-3.9 MICRON IMAGERY...HAS ILLUSTRATED BREAKS IN THE CLOUDINESS ACROSS SOUTH CENTRAL NC AND CENTRAL SC. THIS UPSTREAM CLEARING WILL CONTINUE EAST ACROSS THE ILM CWA THIS EVENING AND OVERNIGHT. WITH NW FLOW ALOFT...A DOWNSLOPE TRAJECTORY...MOISTURE WILL LIKELY FURTHER SCOUR OUT LEAVING A MOSTLY CLEAR TO PARTLY CLOUDY SKY OVERNIGHT. AT THIS POINT...STAYED CLOSER TO THE SLIGHTLY MILDER LOWS ADVERTISED BY THE NAM MOS...ALTHOUGH THE 18Z GFS MOS HAS INCREASED ITS LOWS FROM ITS PREVIOUS 12Z ISSUANCE. HAVE INCREASED THE PATCHY/AREAS OF FOG COVERAGE OVERNIGHT DUE TO LESSER AMOUNT OF CLOUDS BEING FORECAST. PREVIOUS DISCUSSION.............................................. AS OF 230 PM MONDAY...A COOL AND CLOUDY DAY CONTINUES ACROSS MUCH OF THE CAROLINAS. THIS SLIGHTLY UNSETTLED WEATHER IS CAUSED BY A COMBINATION OF TWO FEATURES...A WELL-DEFINED UPPER LEVEL LOW PRESSURE...AND A STRONG SURFACE RIDGE OF HIGH PRESSURE. ALTHOUGH UPPER LOW HAS BEEN DAMPENING ALL DAY...A STILL EASILY-RECOGNIZED CENTER IS MOVING ACROSS SC...AND WILL DRIFT EAST NEARLY OVERHEAD THROUGH TONIGHT. WEAK ISENTROPIC LIFT AHEAD OF THIS FEATURE HAS BEEN PRODUCING LIGHT SHOWERS/SPRINKLES ACROSS THE AREA TODAY...BUT THIS IS SLOWLY WEAKENING...AND GUIDANCE SHOWS IT SHUTTING OFF IN THE NEXT FEW HOURS. STILL...HAVE CONTINUED MENTION OF ISOLATED SHOWERS THROUGH THE EVE...BUT QPF WILL BE GENERALLY ZERO...0.01-0.02 AT BEST. THE SECOND ROUND OF PRECIP BACK ACROSS GEORGIA IS MORE CONVECTIVELY DRIVEN THANKS TO STEEPENED LAPSE RATES BENEATH THE -17C COLD POOL. AS THIS MOVES EAST AND ABOVE THE SURFACE HIGH PRESSURE...IT HAS SHOWN SIGNIFICANT WEAKENING (THANKS ALSO IN PART TO THE UPPER LOW FILLING)...AND THUS DO NOT ANTICIPATE ANY PRECIP AS THE LOW CENTER MOVES OVERHEAD THIS EVE. HIGH-RES GUIDANCE AGREES WITH THIS...NEITHER THE HRRR OR WRF SUGGEST ANY PRECIP ACROSS THE CWA TONIGHT...SO HAVE CUT BACK POP TO SILENT AFTER DARK. WITH THE LACK OF SUNSHINE /DRYING/ TODAY...AND A MOISTENED COLUMN...FOG IS A POSSIBILITY LATE TONIGHT. HAVE CONTINUED MENTION OF PATCHY/AREAS OF FOG ACROSS THE AREA AS BUFR SOUNDINGS DEPICT GOOD SURFACE SATURATION AND LOW-LEVEL HYDROLAPSE RATES...AND FORECAST LOWS APPROACH CROSSOVER TEMPS. THE INHIBITING FACTOR TO WIDESPREAD FOG WILL BE CONTINUED MID-LEVEL CLOUD COVER WHICH WILL INHIBIT...AT LEAST PARTIALLY...RADIATIONAL COOLING. THIS SAME CLOUD COVER WILL KEEP MINS FROM FALLING TOO LOW...AND HAVE LEANED PRIMARILY ON THE WARMER LAV NUMBERS SINCE THE MET/MAV CONTINUE TO BE TOO COOL. EXPECT LOWS A DEGREE OR TWO EITHER SIDE OF 50 ACROSS THE AREA. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 230 PM MONDAY...THE HEADLINE WEATHER STORY TUESDAY THROUGH WEDNESDAY IS THE EVOLUTION OF A LATE OCTOBER WARMING TREND WITH MAXIMUM TEMPERATURES RUNNING 4-9 DEGREES ABOVE NORMAL BOTH DAYS WITH WEDNESDAY BEING THE WARMER. DAYBREAK TUESDAY A SHORT-WAVE WILL BE EXITING THE COAST...AND IN IT`S WAKE AMPLIFICATION OF HEIGHTS ALOFT OCCUR AS AN UPPER RIDGE BULGES INTO THE CAROLINAS ESPECIALLY ON WEDNESDAY. THE PROXIMITY OF HEIGHT RISES WILL BOLSTER SURFACE HIGH PRESSURE...ALLOWING A SURFACE ANTI-CYCLONE OVER THE GREAT LAKES TO BUILD SE INTO CAROLINAS BEFORE SLIPPING OFFSHORE EARLY ON THURSDAY. MINIMUM TEMPERATURES TOO WILL BE RUNNING ABOVE NORMAL FOR THE SEASON BUT ONLY BY SEVERAL DEGREES SINCE OVERNIGHT RADIATION COOLING WILL BE DECENT TO VERY GOOD...ALLOWING HEAT ESCAPE AND SUBSEQUENT NIGHT-TIME COOLING AND A SOLID EARLY MORNING INVERSION EACH DAY. BOUTS OF FOG COULD BE AN ISSUE BUT CONFIDENCE IS NOT HIGH ENOUGH FOR INCLUSION INTO THE ZONES SINCE OCCASIONAL CLOUDS COULD INHIBIT FORMATION. DRY MID-LEVEL AIR DUE TO THE RIDGING ALOFT WILL PREVENT ANY MENTIONABLE POP VALUES THIS PERIOD. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 230 PM MONDAY...THURSDAY HIGHS TO END UP JUST SHY OF 10 DEGREES ABOVE CLIMO WITH SURFACE AND UPPER LEVEL RIDGING OFF THE EAST COAST. SIMILARLY A VERY MID THURSDAY NIGHT EXPECTED AS THE LOW LEVEL FLOW IS INCREASED AND VEERED BY THE APPROACH OF A COLD FRONT. FRIDAY STILL FINDS US IN A VERY WARM AIRMASS BUT INCREASING CLOUD COVER SHOULD TEMPER HIGHS A BIT. THE SLOW MOVEMENT OF THE BOUNDARY WHICH WILL BE ALIGNED WITH THE SOUTHWESTERLY MID LEVEL FLOW IMPLIES THAT PRECIP SHOULD BE HARD-PRESSED TO OCCUR MUCH AHEAD OF THE BOUNDARY ITSELF. BEST RAIN CHANCES THUS COME WITH ACTUAL FROPA FRIDAY NIGHT...INTO SATURDAY MORNING ALONG THE COAST. LOW LEVELS DRY OUT SATURDAY BY THE DEEPER LAYER DRY AIR ADVECTION WILL HAVE TO WAIT FOR THE TOUGH AXIS TO SWEEP THROUGH SATURDAY NIGHT. VERY LARGE HIGH BUILDS ACROSS NORTHEAST AND MID ATLANTIC SUNDAY AND MONDAY. THE ENSUING COLD ADVECTION LOOKS TO SIMPLY RETURN TEMPERATURES TO THEIR SEASONABLE NORMS ON SUNDAY AND ROUGHLY A CATEGORY LOWER BY MONDAY. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... AS OF 00Z...VFR WILL PREVAIL THROUGH THE VALID PERIOD WITH THE EXCEPTION OF AREAS OF FOG POSSIBLY CREATING BRIEF RESTRICTIONS OF MVFR OVERNIGHT INTO THE EARLY MORNING HOURS ON TUESDAY. ISOLATED AREAS OF -DZ HAS TAPERED OFF AS SEEN FROM LATEST RADAR IMAGERY...AS VFR PREVAILS THIS EVENING WITH NEARLY CALM WINDS AND BKN/OVC HIGH CLOUD DECK. POSSIBILITY OF FOG LATE OVERNIGHT INTO THE EARLY MORNING HOURS...WHICH MAY CREATE SHORT-LIVED PERIODS OF MVFR. AFTER DAYBREAK...LIGHT NE WINDS WILL BECOMING ESE BY THE AFTERNOON HOURS AOB 8 KTS...WITH MID/HIGH LEVEL CLOUDS THROUGHOUT THE DAY. WINDS WILL BECOME LIGHT TUESDAY EVENING WITH SCT CLOUDS. EXTENDED OUTLOOK...EARLY MORNING FOG POSSIBLE WEDNESDAY. CHANCE OF SHOWERS FRIDAY INTO SATURDAY WITH AN APPROACHING COLD FRONT. OTHERWISE VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 715 PM MONDAY...WEAK SFC PG AND UNORGANIZED PRESSURE PATTERN THIS EVENING WILL RESULT WITH A VARIABLE WIND DIRECTION LESS THAN 10 KTS THIS EVENING. AFTER MIDNIGHT THROUGH DAYBREAK TUE...STRONG RIDGING CENTERED OVER THE GREAT LAKES...WILL EXPAND SOUTHWARD ACROSS THE FA WATERS. LOOK FOR A MORE DOMINANT WIND DIRECTION... FROM THE NW-N TO OCCUR...WITH SPEEDS AT AROUND 10 KT. SIGNIFICANT SEAS WILL HAVE VERY LITTLE INPUT FROM ANY LOCALLY PRODUCED WIND DRIVEN WAVES. THE 1 TO 1.5 FOOT ESE GROUND SWELL AT 8 TO 9 SECOND PERIODS WILL DOMINATE THE SIGNIFICANT SEAS OVERNIGHT. PREVIOUS DISCUSSION............................................ AS OF 230 PM MONDAY...HIGH PRESSURE WITH A DIFFUSE CENTER ALIGNED ROUGHLY ALONG THE CAROLINA COASTS IS SLOWLY DRIFTING EAST...AS IT GETS PUSHED AWAY BY A MUCH STRONGER HIGH /1040MB CENTERED OVER CENTRAL CANADA/. THIS WILL HAPPEN SLOWLY TONIGHT...THUS THE CURRENT WEAK PRESSURE GRADIENT WILL PERSIST MUCH OF THE PERIOD...ONLY GRADUALLY TIGHTENING TOWARDS DAYBREAK TUESDAY. THIS WILL KEEP LIGHT AND VARIABLE WINDS THROUGH ABOUT MIDNIGHT...BEFORE A WEAK NORTHERLY SURGE DEVELOPS...DRIVING WINDS UP TO AROUND 10 KTS BY MORNING. SEAS WILL REMAIN LOW- AMPLITUDE...1-2 FT...ALTHOUGH AN ISOLATED 3 FTER IS POSSIBLE NEAR THE 20NM BOUNDARY LATE TONIGHT. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...NO ADVISORY OR CAUTIONARY FLAGS EXPECTED ON THE WATERS TUESDAY AND WEDNESDAY...ALTHOUGH WATERS WILL BECOME A BIT BUMPY AS NE WINDS INCREASE DUE TO HIGH PRESSURE BUILDING FROM THE NORTH ON TUESDAY...BECOMING SITUATED MORE OVERHEAD WITH EASING WIND WEDNESDAY. 2-3 FOOT SEAS EXPECTED BUT UP TO 4 FEET OFFSHORE NORTH OF CAPE FEAR AND AROUND NORTHERN FRINGES OF THE FRYING PAN SHOALS/BAR. THE STRONGEST WINDS AND HIGHEST SEAS CAN BE EXPECTED TUESDAY AFTERNOON INTO EVENING AS THE HIGH BUILDS SOUTH TOWARD OUR COAST. NO TSTMS ON THE 0-20NM WATERS THROUGH THE PERIOD ALTHOUGH A FEW TSTMS MAY BE ONGOING OVER THE GULF STREAM EARLY TUESDAY. SEAS WILL BE MADE UP OF 2 FT ESE WAVES EVERY 8-10 SECONDS MIXED WITH 1-2 FT E WAVES IN 5-6 SECOND INTERVALS. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 230 PM MONDAY...BROAD SOUTHERLY FLOW WILL BE FOUND ACROSS ALMOST THE ENTIRE EASTERN HALF OF THE NATION ON THURSDAY AS LARGE HIGH SITS OVER THE WEST ATLANTIC AND A COLD FRONT PRESSES EAST ACROSS THE NATIONS MIDSECTION. BUILDING SEAS WILL BE COMPRISED OF AN 11 SEC SE SWELL AND A LATE DAY/NIGHTTIME BUILDING WIND WAVE THAT COULD EVENTUALLY YIELD ADVISORY-LEVEL SEAS. AS THE SLOW MOVING FRONT APPROACHES FROM THE WEST ON FRIDAY THE GRADIENT WILL BE FURTHER TIGHTENING AND THE WIND FORECAST MAY RISE A CATEGORY INTO THE 20 TO 25KT RANGE ESPECIALLY OVER NORTHERN ZONES. A WELL PRONOUNCED VEER ASSOCIATED WITH LATE FRIDAY NIGHT FRONTAL PASSAGE TURNS THE WINDS FROM COAST-PARALLEL TO ALMOST PERPENDICULAR OFFSHORE. THIS OPENS UP A NEARSHORE/OFFSHORE GRADIENT IN WAVE HEIGHTS AS THE NEAR SHORE SEAS DIMINISH QUICKLY FROM LANDMASS SHADOWING. FURTHER FROM SHORE SEAS WILL EASE WITH LESS RAPIDITY BUT EASE NONETHELESS AS THE GRADIENT WEAKENS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MJC NEAR TERM...DCH/JDW SHORT TERM...MJC LONG TERM...MBB AVIATION...SGL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
749 AM EDT SUN OCT 27 2013 .SYNOPSIS... AN AREA OF HIGH PRESSURE WILL BRIEFLY BUILD OVER THE REGION FROM THE SOUTH TODAY AND TONIGHT. A WEAK COLD FRONT WILL MOVE SOUTH ACROSS THE LOCAL AREA ON MONDAY. ANOTHER AREA OF HIGH PRESSURE WILL BUILD IN FROM THE NORTH ON TUESDAY. A STORM SYSTEM WILL AFFECT THE REGION LATE WEDNESDAY INTO FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MADE SOME SLIGHT CHANGES TO THE SKY FORECAST BASED ON CURRENT SATELLITE TRENDS. LATEST HRRR MODEL IS STILL HINTING AT SHOWERS DEVELOPING OVER NW PA LATER THIS AM SO WILL LEAVE A PRECIP MENTION IN. ORIGINAL...THE COLD FRONT THAT BROUGHT RAIN TO THE AREA SATURDAY EVENING HAS MOVED INTO PENNSYLVANIA AND WILL CONTINUE TO MOVE EAST TODAY. THIS WILL ALLOW AN AREA OF WEAK HIGH PRESSURE TO BUILD INTO THE REGION TODAY. LOTS OF MID LEVEL CLOUDS MOVING OVER THE AREA THIS MORNING. THIS WILL BE THE TREND FOR THE DAY WITH BROKEN TO OCCASIONALLY SCATTERED SKIES. TEMPS WILL GET OFF TO A COOL START THIS MORNING BUT STILL THINK MUCH OF THE AREA HAS A SHOT AT GETTING TO 50 DEGREES THIS AFTERNOON. THE FLOW WILL REMAIN OFF THE LAKE TODAY EAST OF KCLE SO A FEW SHOWERS REMAIN POSSIBLE INTO THE AFTERNOON HOURS. MOST OF THIS ACTIVITY WILL BE CONFINED TO NW PA AND WOULD BE SURPRISED TO SEE MUCH MORE THAN A COUPLE HUNDREDTHS EVEN IF IT DOES RAIN. AS IT STANDS...THE PREVIOUS FORECAST HAD A SMALL AREA OF CHANCE POPS AND THAT SEEMS REASONABLE. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... THE AREA WILL ENJOY A FEW PERIODS OF DRY WEATHER BEFORE THE SYSTEM OVER THE PLAINS BEGINS TO IMPACT THE AREA TOWARD THE END OF THE PERIOD. TONIGHT WILL BE QUIET WITH COOL TEMPERATURES. A WEAK COLD FRONT WILL MOVE ACROSS THE LOCAL AREA ON MONDAY. MODELS... INCLUDING THE SREF CONTINUE TO SHOW A FEW SHOWERS OVER EASTERN LAKE ERIE AND PERHAPS NW PA. WILL GO WITH A SMALL PRECIP MENTION TOMORROW AFTERNOON IN NW PA BUT REALLY NOT EXPECTING MUCH MORE THAN SPRINKLES OR A BRIEF LIGHT SHOWER. ANOTHER HIGH WILL MOVE ACROSS THE REGION ON TUESDAY. TEMPS WON`T GET AS WARM AS PREVIOUSLY FORECAST BUT ALL AREAS SHOULD MAKE THE LOW TO MID 50S. THE MODELS CONTINUE TO SLOW THE ONSET OF PRECIPITATION WITH THE PLAINS LOW. IT NOW APPEARS THAT MOST IF NOT ALL OF WEDNESDAY WILL BE DRY AND WILL LIMIT PRECIP CHANCES TO THE WEST THROUGH LATE AFTERNOON. BETTER CHANCES WILL ARRIVE WEDNESDAY NIGHT. EXPECT TEMPS WEDNESDAY TO BE A TAD WARMER THAN TUESDAY EVEN WITH MORE CLOUDS. HAVE USED A BLEND OF GUIDANCE MOST OF THE PERIOD. && .LONG TERM /THURSDAY THROUGH SATURDAY/... UPPER LEVEL TROUGH WILL START THE PERIOD OVER THE PLAINS AND LIFT NORTHEAST TOWARDS THE GREAT LAKES REGION ON THURSDAY. SOUTHERN STREAM JET ENERGY COMING OFF THE PACIFIC WILL PROVIDE THE MECHANISM FOR STRONG MOISTURE TRANSPORT TOWARDS THE REGION IN ADVANCE OF THE TROUGH WITH PW VALUES INCREASING TO AROUND 1.3 INCHES. THE 00Z GFS IS FASTER THAN MOST OF THE OTHER LONG RANGE MODELS...INCLUDING MANY OF THE GFS ENSEMBLE MEMBERS BY THURSDAY. WILL ONLY CARRY CHANCE POPS ON THURSDAY FOR MOST AREAS AS WE RESIDE IN THE WARM SECTOR AHEAD OF THE APPROACHING TROUGH. ALTHOUGH WE WILL HAVE AMPLE CLOUD COVER ON THURSDAY...STRONG WARM ADVECTION WITH SOUTHERLY WINDS WILL PUSH TEMPERATURES INTO THE UPPER 60S. WIDESPREAD RAIN IS THEN EXPECTED FOR THURSDAY NIGHT AS THE LOW PRESSURE SYSTEM TRACKS NORTHEAST ACROSS THE CENTRAL GREAT LAKES. ALSO RAISED LOWS BY SEVERAL DEGREES ACROSS THE EASTERN HALF OF THE FORECAST AREA ON THURSDAY NIGHT. HIGHS ON FRIDAY WILL OCCUR EARLY IN THE DAY AHEAD OF THE COLD FRONT. RAIN WILL COME TO AN END FROM WEST TO EAST WITH PARTIAL CLEARING AS THE DRY-SLOT WRAPS OVERHEAD. TEMPERATURES WILL DROP BACK BELOW NORMAL FOR THE WEEKEND WITH NORTHWESTERLY FLOW. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... A BKN-OVC CLOUD DECK NEAR 6000 FEET WILL CONTINUE TO OVERSPREAD THE TAF SITES FROM WEST TO EAST THROUGH 13Z. VISIBILITIES MAY BRIEFLY DROP BELOW VFR AT YNG/CAK WITH PATCHY FOG BEFORE THE CLOUDS ARRIVE BUT WILL NOT LAST LONG. OTHERWISE VFR CONDITIONS EXPECTED THROUGH THE TAF CYCLE WITH HIGH PRESSURE BUILDING EAST ACROSS THE OHIO VALLEY. WEST TO SOUTHWEST WINDS WILL INCREASE TO 7-10 KNOTS TODAY THEN DECREASE AGAIN BY 00Z. CLOUDS WILL SCATTER OUT LATE THIS AFTERNOON. OUTLOOK...NON-VFR POSSIBLE MONDAY NIGHT ACROSS NRN OH/NW PA. NON- VFR ON WEDNESDAY THEN AGAIN IN RAIN SHOWERS ON THURSDAY. && .MARINE... WINDS AND WAVES ON LAKE ERIE WEST OF VERMILION HAVE DROPPED BELOW SMALL CRAFT ADVISORY CRITERIA THUS THE ADVISORY HAS BEEN CANCELLED. IT WILL TAKE UNTIL LATER THIS MORNING FOR THE WAVES OFFSHORE OF CLEVELAND TO DROP OFF SO HAVE ADJUSTED THE END TIME ON THE ADVISORY TO 10 AM. WE WILL MAINTAIN A WESTERLY TO SOUTHWEST WIND OF 15 TO 20 KNOTS ON THE EAST HALF OF THE LAKE THROUGH TONIGHT AND WAVES WILL REMAIN IN THE 4 TO 7 FOOT RANGE INTO MONDAY MORNING SO EXTENDED THE SMALL CRAFT ADVISORY EAST OF WILLOWICK. A BACK DOOR COLD FRONT WILL MOVE SOUTH ACROSS THE LAKE ON MONDAY WITH A WIND SHIFT TO THE NORTH. THIS WILL BE FOLLOWED BY STRONG HIGH PRESSURE BUILDING EAST ACROSS THE REGION THROUGH WEDNESDAY WITH GENERALLY GOOD MARINE CONDITIONS THROUGH MID-WEEK. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT MONDAY FOR LEZ147>149. SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LEZ145- 146. && $$ SYNOPSIS...KUBINA NEAR TERM...KUBINA SHORT TERM...KUBINA LONG TERM...KEC AVIATION...KEC MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
626 AM EDT SUN OCT 27 2013 .SYNOPSIS... AN AREA OF HIGH PRESSURE WILL BRIEFLY BUILD OVER THE REGION FROM THE SOUTH TODAY AND TONIGHT. A WEAK COLD FRONT WILL MOVE SOUTH ACROSS THE LOCAL AREA ON MONDAY. ANOTHER AREA OF HIGH PRESSURE WILL BUILD IN FROM THE NORTH ON TUESDAY. A STORM SYSTEM WILL AFFECT THE REGION LATE WEDNESDAY INTO FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MADE SOME SLIGHT CHANGES TO THE SKY FORECAST BASED ON CURRENT SATELLITE TRENDS. LATEST HRRR MODEL IS STILL HINTING AT SHOWERS DEVELOPING OVER NW PA LATER THIS AM SO WILL LEAVE A PRECIP MENTION IN. ORIGINAL...THE COLD FRONT THAT BROUGHT RAIN TO THE AREA SATURDAY EVENING HAS MOVED INTO PENNSYLVANIA AND WILL CONTINUE TO MOVE EAST TODAY. THIS WILL ALLOW AN AREA OF WEAK HIGH PRESSURE TO BUILD INTO THE REGION TODAY. LOTS OF MID LEVEL CLOUDS MOVING OVER THE AREA THIS MORNING. THIS WILL BE THE TREND FOR THE DAY WITH BROKEN TO OCCASIONALLY SCATTERED SKIES. TEMPS WILL GET OFF TO A COOL START THIS MORNING BUT STILL THINK MUCH OF THE AREA HAS A SHOT AT GETTING TO 50 DEGREES THIS AFTERNOON. THE FLOW WILL REMAIN OFF THE LAKE TODAY EAST OF KCLE SO A FEW SHOWERS REMAIN POSSIBLE INTO THE AFTERNOON HOURS. MOST OF THIS ACTIVITY WILL BE CONFINED TO NW PA AND WOULD BE SURPRISED TO SEE MUCH MORE THAN A COUPLE HUNDREDTHS EVEN IF IT DOES RAIN. AS IT STANDS...THE PREVIOUS FORECAST HAD A SMALL AREA OF CHANCE POPS AND THAT SEEMS REASONABLE. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... THE AREA WILL ENJOY A FEW PERIODS OF DRY WEATHER BEFORE THE SYSTEM OVER THE PLAINS BEGINS TO IMPACT THE AREA TOWARD THE END OF THE PERIOD. TONIGHT WILL BE QUIET WITH COOL TEMPERATURES. A WEAK COLD FRONT WILL MOVE ACROSS THE LOCAL AREA ON MONDAY. MODELS... INCLUDING THE SREF CONTINUE TO SHOW A FEW SHOWERS OVER EASTERN LAKE ERIE AND PERHAPS NW PA. WILL GO WITH A SMALL PRECIP MENTION TOMORROW AFTERNOON IN NW PA BUT REALLY NOT EXPECTING MUCH MORE THAN SPRINKLES OR A BRIEF LIGHT SHOWER. ANOTHER HIGH WILL MOVE ACROSS THE REGION ON TUESDAY. TEMPS WON`T GET AS WARM AS PREVIOUSLY FORECAST BUT ALL AREAS SHOULD MAKE THE LOW TO MID 50S. THE MODELS CONTINUE TO SLOW THE ONSET OF PRECIPITATION WITH THE PLAINS LOW. IT NOW APPEARS THAT MOST IF NOT ALL OF WEDNESDAY WILL BE DRY AND WILL LIMIT PRECIP CHANCES TO THE WEST THROUGH LATE AFTERNOON. BETTER CHANCES WILL ARRIVE WEDNESDAY NIGHT. EXPECT TEMPS WEDNESDAY TO BE A TAD WARMER THAN TUESDAY EVEN WITH MORE CLOUDS. HAVE USED A BLEND OF GUIDANCE MOST OF THE PERIOD. && .LONG TERM /THURSDAY THROUGH SATURDAY/... UPPER LEVEL TROUGH WILL START THE PERIOD OVER THE PLAINS AND LIFT NORTHEAST TOWARDS THE GREAT LAKES REGION ON THURSDAY. SOUTHERN STREAM JET ENERGY COMING OFF THE PACIFIC WILL PROVIDE THE MECHANISM FOR STRONG MOISTURE TRANSPORT TOWARDS THE REGION IN ADVANCE OF THE TROUGH WITH PW VALUES INCREASING TO AROUND 1.3 INCHES. THE 00Z GFS IS FASTER THAN MOST OF THE OTHER LONG RANGE MODELS...INCLUDING MANY OF THE GFS ENSEMBLE MEMBERS BY THURSDAY. WILL ONLY CARRY CHANCE POPS ON THURSDAY FOR MOST AREAS AS WE RESIDE IN THE WARM SECTOR AHEAD OF THE APPROACHING TROUGH. ALTHOUGH WE WILL HAVE AMPLE CLOUD COVER ON THURSDAY...STRONG WARM ADVECTION WITH SOUTHERLY WINDS WILL PUSH TEMPERATURES INTO THE UPPER 60S. WIDESPREAD RAIN IS THEN EXPECTED FOR THURSDAY NIGHT AS THE LOW PRESSURE SYSTEM TRACKS NORTHEAST ACROSS THE CENTRAL GREAT LAKES. ALSO RAISED LOWS BY SEVERAL DEGREES ACROSS THE EASTERN HALF OF THE FORECAST AREA ON THURSDAY NIGHT. HIGHS ON FRIDAY WILL OCCUR EARLY IN THE DAY AHEAD OF THE COLD FRONT. RAIN WILL COME TO AN END FROM WEST TO EAST WITH PARTIAL CLEARING AS THE DRY-SLOT WRAPS OVERHEAD. TEMPERATURES WILL DROP BACK BELOW NORMAL FOR THE WEEKEND WITH NORTHWESTERLY FLOW. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... HIGH PRESSURE WILL BUILD OVER THE OHIO VALLEY INTO SUNDAY MORNING WITH LIGHT WESTERLY WINDS AT ALL SITES EXCEPT ERI. THE FLOW OFF THE LAKE WILL MAINTAIN WESTERLY WINDS NEAR 10 KNOTS WITH OCCASIONAL GUSTS TO 20 KNOTS. PRECIPITATION HAS EXITED TO THE EAST WITH SKIES STARTING OFF AS MOSTLY CLEAR EXCEPT DOWNWIND OF LAKE ERIE AT ERI/YNG WHERE VFR CLOUDS WILL HANG ON FOR A FEW MORE HOURS. A CLOUD DECK NEAR 6000 FEET IS ALSO APPROACHING FROM THE WEST AND WILL MOVE INTO THE WESTERN SITES OVERNIGHT...WITH A BKN STRATOCU DECK RETURNING TO MOST AREAS WITH DIURNAL HEATING ON SUNDAY. LIGHT WINDS WILL BACK TO SOUTHWESTERLY BY SUNDAY EVENING. OUTLOOK...NON-VFR POSSIBLE MONDAY NIGHT ACROSS NRN OH/NW PA. NON- VFR POSSIBLE IN RAIN SHOWERS ON THURSDAY. && .MARINE... WINDS AND WAVES ON LAKE ERIE WEST OF VERMILION HAVE DROPPED BELOW SMALL CRAFT ADVISORY CRITERIA THUS THE ADVISORY HAS BEEN CANCELLED. IT WILL TAKE UNTIL LATER THIS MORNING FOR THE WAVES OFFSHORE OF CLEVELAND TO DROP OFF SO HAVE ADJUSTED THE END TIME ON THE ADVISORY TO 10 AM. WE WILL MAINTAIN A WESTERLY TO SOUTHWEST WIND OF 15 TO 20 KNOTS ON THE EAST HALF OF THE LAKE THROUGH TONIGHT AND WAVES WILL REMAIN IN THE 4 TO 7 FOOT RANGE INTO MONDAY MORNING SO EXTENDED THE SMALL CRAFT ADVISORY EAST OF WILLOWICK. A BACK DOOR COLD FRONT WILL MOVE SOUTH ACROSS THE LAKE ON MONDAY WITH A WIND SHIFT TO THE NORTH. THIS WILL BE FOLLOWED BY STRONG HIGH PRESSURE BUILDING EAST ACROSS THE REGION THROUGH WEDNESDAY WITH GENERALLY GOOD MARINE CONDITIONS THROUGH MID-WEEK. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT MONDAY FOR LEZ147>149. SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LEZ145- 146. && $$ SYNOPSIS...KUBINA NEAR TERM...KUBINA SHORT TERM...KUBINA LONG TERM...KEC AVIATION...KEC MARINE...KEC
AREA FORECAST DISCUSSION
NWS TULSA OK
952 PM CDT MON OCT 28 2013 .DISCUSSION... A FEW SHOWERS ARE BEGINNING TO DEVELOP ACROSS PARTS OF NORTHEAST OKLAHOMA AT THIS TIME. THIS ACTIVITY IS EXPECTED TO CONTINUE TO DEVELOP AND INCREASE IN BOTH COVERAGE AND INTENSITY OVERNIGHT PER THE LATEST HRRR MODEL DATA. THE MOST WIDESPREAD SHOWERS AND STORMS OVERNIGHT WILL LIKELY REMAIN NORTH OF INTERSTATE 44 AND THE BEST CHANCE FOR ANY ISOLATED SEVERE STORMS WILL BE TO THE NORTH OF THE OKLAHOMA/KANSAS BORDER. HAVE LOWERED POPS SLIGHTLY OVERNIGHT IN MOST PLACES BASED ON THE LATEST HRRR AND NAM MODEL RUNS. THE REST OF THE FORECAST LOOKS GOOD AT THIS TIME. UPDATE ON THE WAY. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...10 LONG TERM....05 PLATE
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1210 PM CDT SUN OCT 27 2013 .AVIATION 18Z DISCUSSION...STEADY STATE BKN-OVC CONDITIONS EXPECTED WITH CIGS GENERALLY IN THE 3KFT-5KFT RANGE. A WEAK STATIONARY BOUNDARY WILL ATTEMPT TO INTERACT WITH AN APPROACHING SHORTWAVE THIS EVENING AND TONIGHT. THUS...WILL INCLUDE VCSH FOR THE BNA AREA TONIGHT. FURTHER EAST...MOISTURE DEPTH WILL BE MORE FAVORABLE AND A TEMPO GROUP FOR -SHRA WILL BE INCLUDED AFT 05Z FOR CSV. PRECIP CHANCES WILL LESSEN AFT 12Z BUT CLOUDS WILL REMAIN. && .PREV DISCUSSION... /ISSUED 859 AM CDT SUN OCT 27 2013/ DISCUSSION UPDATE... CLOUDS IN PLACE ACROSS THE MID STATE. MODEL DATA SUPPORTS A CONTINUATION OF THE CLOUDINESS THROUGH THE DAY. CLOSEST SHOWER ACTIVITY IS OCCURRING BACK ACROSS AR AND INTO NRN MS. THIS IS IN ASSOCIATION WITH A WEAK UPPER LEVEL SHORTWAVE JUST EAST OF THE ARKLATEX. THIS FEATURE IS EXPECTED TO SLOWLY MOVE EAST TODAY AND PROVIDE A SLIGHT CHANCE OF SHOWER ACTIVITY FOR OUR AREA. A STATIONARY FRONTAL BOUNDARY IS IN PLACE ACROSS THE MID STATE THIS MORNING BUT LITTLE IN THE WAY OF SFC FORCING IS INDICATED. FOR THE FCST...LITTLE CHANGE IF ANY IS NEEDED AT THIS TIME. WAS THINKING ABOUT PERHAPS LOWERING MAX TEMPS A DEGREE OR TWO. BUT...18Z SFC TEMP PROGS CLEARLY SUPPORT THE CURRENT FCST HIGHS. WILL THEREFORE MAKE NO CHANGES FOR NOW. A SLIGHT CHANCE OF SHOWERS SOUTH AND SPRINKLES NORTH SHOULD CONTINUE TO COVER IT. HRRR IS IN GENERAL AGREEMENT. PREV DISCUSSION... /ISSUED 752 AM CDT SUN OCT 27 2013/ UPDATE...FOR 12Z AVIATION FORECASTS. AVIATION...EXPECT COPIOUS AMOUNTS OF LOW LEVEL MOISTURE TO KEEP CIGS NR 5K FT THROUGHOUT THE FORECAST PERIOD. POSSIBLE PATCHES OF MVFR IN BR, WHERE CLOUDS BREAK DURING THE LATE NIGHT AND EARLY MORNING HOURS. OTHERWISE, VFR. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION...CORRECTED LAST SENTENCE
NWS NASHVILLE TN
859 AM CDT SUN OCT 27 2013 .DISCUSSION UPDATE... CLOUDS IN PLACE ACROSS THE MID STATE. MODEL DATA SUPPORTS A CONTINUATION OF THE CLOUDINESS THROUGH THE DAY. CLOSEST SHOWER ACTIVITY IS OCCURRING BACK ACROSS AR AND INTO NRN MS. THIS IS IN ASSOCIATION WITH A WEAK UPPER LEVEL SHORTWAVE JUST EAST OF THE ARKLATEX. THIS FEATURE IS EXPECTED TO SLOWLY MOVE EAST TODAY AND PROVIDE A SLIGHT CHANCE OF SHOWER ACTIVITY FOR OUR AREA. A STATIONARY FRONTAL BOUNDARY IS IN PLACE ACROSS THE MID STATE THIS MORNING BUT LITTLE IN THE WAY OF SFC FORCING IS INDICATED. FOR THE FCST...LITTLE CHANGE IF ANY IS NEEDED AT THIS TIME. WAS THINKING ABOUT PERHAPS LOWERING MAX TEMPS A DEGREE OR TWO. BUT...18Z SFC TEMP PROGS CLEARLY SUPPORT THE CURRENT FCST HIGHS. WILL THEREFORE MAKE NO CHANGES FOR NOW. A SLIGHT CHANCE OF SHOWERS SOUTH AND SPRINKLES NORTH SHOULD CONTINUE TO COVER IT. HRRR IS IN GENERAL AGREEMENT. && .PREV DISCUSSION... /ISSUED 752 AM CDT SUN OCT 27 2013/ UPDATE...FOR 12Z AVIATION FORECASTS. AVIATION...EXPECT COPIOUS AMOUNTS OF LOW LEVEL MOISTURE TO KEEP CIGS NR 5K FT THROUGHOUT THE FORECAST PERIOD. POSSIBLE PATCHES OF MVFR IN BR, WHERE CLOUDS BREAK DURING THE LATE NIGHT AND EARLY MORNING HOURS. OTHERWISE, VFR. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1140 PM CDT SAT OCT 26 2013 .UPDATE... UPDATED FOR 06Z AVIATION DISCUSSION. && .PREV DISCUSSION... /ISSUED 958 PM CDT SAT OCT 26 2013/ UPDATE...EVENING UPDATE. CURRENTLY...AT 9PM...A CONVECTIVE COMPLEX IS DIGGING SSE-WARD TOWARDS THE ARKLATEX BORDER ALONG WITH AN ASSOCIATED SURFACE LOW LOCATED OVER THE DALLAS/FORT WORTH METRO AREA. THESE FEATURES ARE CONTRIBUTING TO THE SHOWERS AND THUNDERSTORM ACTIVITY IN THAT REGION. SOME SINKING MOTION LOCATED AROUND THE PERIPHERY OF THIS SYSTEM IS EFFECTIVELY INHIBITING ANY SHOWERS FROM REACHING OUR AREA. THEREFORE...HAVE TRIMMED BACK POPS FROM NOW UNTIL 12Z. HAVE ALSO BUMPED UP TEMPS A COUPLE OF DEGREES AROUND THE TENNESSEE RIVER AND MISSISSIPPI RIVERS IN WEST TENNESSEE AS DENSE CLOUD COVER WILL PREVENT ANY RAPID COOLING THIS EVENING. TEMPERATURES...AS OF 9PM...ARE RUNNING 15-20 DEGREES WARMER THAN AT THIS TIME YESTERDAY DUE TO THE WAA THIS AFTERNOON AND EARLY EVENING. EXPECT TEMPS TO REMAIN IN THE MID TO UPPER 40S ACROSS THE MAJORITY OF THE REGION OVERNIGHT. UPDATED ZONES WILL BE AVAILABLE SHORTLY. NO FURTHER CHANGES WERE MADE TO THE FORECAST. AC3 UPDATE... UPDATED FOR 00Z AVIATION DISCUSSION. PREV DISCUSSION... /ISSUED 345 PM CDT SAT OCT 26 2013/ DISCUSSION...20Z SURFACE ANALYSIS PLACES A COLD FRONT FROM SOUTHERN LAKE HURON SOUTHWEST BACK THROUGH SAINT LOUIS AND EXTENDING SOUTHWEST ALONG THE I-44 CORRIDOR AND INTO A SURFACE LOW LOCATED ACROSS THE RED RIVER VALLEY OF TEXAS/OKLAHOMA. A FEW RAIN SHOWERS HAVE DEVELOPED ALONG A WARM FRONT NEAR TEXARKANA...PRODUCING SOME RAIN SHOWERS ACROSS SOUTHWEST/SOUTH CENTRAL ARKANSAS LATE THIS AFTERNOON. RAIN CHANCES FOR TONIGHT AND AGAIN FOR MUCH OF NEXT WEEK REMAINS THE CHALLENGE IN THIS FORECAST. A WEAK COLD FRONT CURRENTLY LOCATED UPSTREAM OF THE MID SOUTH ACROSS MISSOURI WILL CONTINUE TO SLOWLY DROP SOUTHEAST INTO THE LOWER MISSISSIPPI VALLEY TONIGHT. LATEST SHORT TERM MODEL TRENDS INCLUDING THE 3KM HRRR INDICATE THE BEST RAINFALL POTENTIAL WILL REMAIN MAINLY SOUTH AND WEST OF THE FORECAST AREA TONIGHT WHERE BETTER MOISTURE AND ISENTROPIC LIFT WILL RESIDE. NONETHELESS...THINK BEST CHANCES RAIN /ISOLATED-SCATTERED COVERAGE/ WILL BE PREDOMINANTLY ACROSS PORTIONS OF EAST ARKANSAS AND NORTHWEST MISSISSIPPI. THIS FRONT WILL LINGER ACROSS NORTH MISSISSIPPI ON SUNDAY WITH ISOLATED RAIN CHANCES STILL POSSIBLE UNTIL THE FRONT PROGRESSES FURTHER SOUTH OF THE AREA. WRF/GFS/ECMWF MODELS INDICATE THIS FRONT WILL RETURN BACK NORTH AS A WARM FRONT MONDAY WITH ABOVE NORMAL TEMPERATURES RETURNING FOR THE MIDDLE OF NEXT WEEK AND SHOWER AND THUNDERSTORM CHANCES BEING CONFINED MOSTLY TO EAST/NORTHEAST ARKANSAS...AND THE MISSOURI BOOTHEEL. GFS/ECMWF LONG TERM MODELS CONTINUE TO DISAGREE WITH THE TIMING OF A DEEPER UPPER LEVEL TROUGH AND ASSOCIATED COLD FRONT MOVING THROUGH THE LOWER MISSISSIPPI VALLEY LATE NEXT WEEK. THE GFS CONTINUES TO BE ON THE QUICKER SIDE OF GUIDANCE THAN THE ECMWF. WILL CONTINUE TO LEAN FORECAST TOWARDS THE ECMWF UNTIL MODELS SHOW BETTER AGREEMENT AND RAIN CHANCES MAY NEED TO BE RAISED UPWARD ACCORDINGLY IN SUBSEQUENT FORECASTS FOR THURSDAY/FRIDAY. && .AVIATION... 06Z TAFS ELEVATED GULF MOISTURE AROUND FL050 WILL SPREAD THROUGH THE MIDSOUTH DURING THE OVERNIGHT... AHEAD OF A WEAKENING MIDLEVEL DISTURBANCE OVER SOUTHWEST AR. MOIST LOW LEVELS WERE EVIDENT ON THE 04Z SURFACE ANALYSIS OVER CENTRAL AR...WITH AN LIFR CIG REPORTED AT LIT. SOME OF THIS LOW LEVEL MOISTURE MAY MOVE INTO AREAS SOUTH AND WEST OF MEM DURING THE OVERNIGHT. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
628 PM CDT MON OCT 28 2013 .DISCUSSION... SEE AVIATION FOR THE 00Z TAF DISCUSSION. && .AVIATION... A MODERATE S TO SE FLOW IN THE BOUNDARY LAYER WILL RESULT IN THE EARLY ONSET OF MVFR CIGS THIS EVENING. THIS WILL INHIBIT SIGNIFICANT FOG FORMATION...WITH PATCHY VSBYS REMAINING AOA 1 MILE IN AREAS THAT EXPERIENCE DELAYED LOW CLOUD DEVELOPMENT. THERE ARE SOME TIMING DIFFERENCES BETWEEN THE 12Z HIRES-ARW AND THE 21Z RUC13 IN REGARDS TO THE FORMATION OF MVFR CIGS TONIGHT. WILL LEAN TOWARDS A BLEND OF THE SLOWER RUC13 AND LATEST LAMP MOS GUIDANCE. I-35 TERMINALS...MVFR CIGS WILL FORM BETWEEN 04Z AND 06Z...LOWERING TO IFR BY 11Z. CIGS IMPROVE TO MVFR BY 15Z...VFR BY 17Z. SFC WINDS OVERNIGHT SE AT 5 TO 8 KTS...SE 10 TO 15 KTS TUESDAY AFTERNOON. KDRT TERMINAL...MVFR CIGS FORM AROUND 07Z LOWERING TO IFR BY 10Z. CIGS IMPROVE TO MVFR BY 16Z...VFR BY 20Z. SFC WINDS OVERNIGHT SE AT 5 TO 10 KTS...AROUND 15 KTS TUESDAY AFTERNOON. && .PREV DISCUSSION... /ISSUED 323 PM CDT MON OCT 28 2013/ SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)... WARM SOUTHERLY FLOW IN THE BOUNDARY LAYER AND PACIFIC MOISTURE STREAMING INTO THE AREA IN THE UPPER LEVELS WILL RESULT IN ANOTHER HUMID AND CLOUDY NIGHT. SFC PRESSURE GRADIENTS APPEAR TO REMAIN TOO TIGHT TO PROMOTE WIDESPREAD DEVELOPMENT OF FOG...BUT COULD SEE PATCHY FOG DEVELOP IN THE NEAR-SUNRISE HOURS ACROSS EASTERN PORTIONS OF THE REGION. AN UPPER LEVEL LOW ACROSS THE WESTERN U.S. WILL PUSH EASTWARD TOWARD THE ROCKIES ON TUESDAY. THIS WILL ENHANCE THE SOUTHEASTERLY FLOW ACROSS OUR AREA AND RESULT IN ANOTHER PARTLY TO MOSTLY CLOUDY AND UNSEASONABLY WARM AFTERNOON. DEEPENING MOISTURE THROUGH THE LOWER LEVELS AND INCREASING INSTABILITY AS THE UPPER LOW APPROACHES WILL LEAD TO ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE HILL COUNTRY TUESDAY AFTERNOON. AN INCREASE IN AREAL COVERAGE IS EXPECTED TUESDAY NIGHT. OTHERWISE...THE CLOUDY MUGGY AND MILD PATTERN WILL PERSIST TUESDAY NIGHT WITH LOWS REMAINING MOSTLY NEAR 70. LONG TERM (WEDNESDAY THROUGH MONDAY)... AS THE UPPER LOW CONTINUES TO PUSH EASTWARD INTO THE CENTRAL PLAINS...IT WILL TRANSITION TO AN OPEN WAVE/TROUGH. A COLD FRONT WILL DEVELOP WITH THIS SYSTEM AND DIG INTO TEXAS ON THURSDAY. AHEAD OF THE PASSAGE OF THE FRONT...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE DRAMATICALLY ON WEDNESDAY AND WEDNESDAY NIGHT BEFORE TAPERING OFF THURSDAY AFTERNOON WITH THE FROPA. MODELS ARE PROJECTING PW VALUES TO SURGE TO ABOVE 2 INCHES ACROSS EASTERN PORTIONS OF THE REGION BY WEDNESDAY (NORMAL PWS FOR LATE OCTOBER ARE GENERALLY 1.25 TO 1.5 INCHES). GIVEN OUR POSITION IN THE WARM SECTOR AHEAD OF THE FRONT AND THE AMPLE MOISTURE...THERE IS A THREAT FOR LOCALLY HEAVY RAINFALL WITH THESE STORMS. RAINFALL TOTALS ARE EXPECTED TO AVERAGE ONE TO THREE INCHES...WITH ISOLATED TOTALS OF 5 INCHES OR MORE POSSIBLE. A FLASH FLOOD WATCH MAY BE NECESSARY. THE COLD FRONT WILL REACH THE COAST LATE THURSDAY AFTERNOON AND DRIER AIR WILL BEGIN TO FILTER INTO THE REGION THURSDAY NIGHT. THURSDAY EVENING WILL BE MILD WITH A LIGHT NORTHERLY WIND. TEMPERATURES WILL FALL TO THE UPPER 60S ACROSS MUCH OF THE REGION (LOW 60S HILL COUNTRY) BY 9 PM. THE DRIER AIR ENTERING THE REGION WILL BEGIN TO CLEAR OUT SKIES FROM NORTH TO SOUTH THURSDAY NIGHT. LOW TEMPERATURES FRIDAY MORNING WILL RANGE FROM THE MID 40S ACROSS THE HILL COUNTRY TO NEAR 60 ACROSS OUR SOUTHERN COUNTIES. UPPER LEVEL FLOW WILL BE NORTHWESTERLY ON FRIDAY AND FLATTEN-OUT OVER THE WEEKEND. THIS WILL KEEP A DRY AIRMASS OVER OUR AREA AND RESULT IN CHILLY MORNINGS AND WARM AFTERNOONS. SOUTHEASTERLY WINDS WILL RETURN IN THE LOWER LEVELS ON SUNDAY LEADING TO A RAPID WARMING TREND OF OVERNIGHT LOWS DURING THE BEGINNING OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 70 84 70 82 71 / 10 10 30 60 70 AUSTIN BERGSTROM INTL AIRPORT 67 84 70 80 71 / 10 10 30 60 70 NEW BRAUNFELS MUNI AIRPORT 68 85 71 82 70 / - 10 30 50 70 BURNET MUNI AIRPORT 67 81 67 78 66 / 10 10 30 70 70 DEL RIO INTL AIRPORT 70 83 71 83 65 / - 20 30 30 30 GEORGETOWN MUNI AIRPORT 67 82 68 81 68 / 10 10 30 70 70 HONDO MUNI AIRPORT 72 87 73 85 70 / - 10 30 50 50 SAN MARCOS MUNI AIRPORT 67 84 70 81 70 / - 10 30 60 70 LA GRANGE - FAYETTE REGIONAL 70 87 73 83 74 / 10 10 20 50 70 SAN ANTONIO INTL AIRPORT 72 86 73 83 71 / - 10 30 50 60 STINSON MUNI AIRPORT 72 88 73 85 73 / - 10 30 50 60 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...13 SYNOPTIC/GRIDS...04 PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1115 AM CDT SUN OCT 27 2013 .DISCUSSION...SHOWERS ACROSS SOUTH CENTRAL TEXAS ARE EXPECTED TO CONTINUE TO SLOWLY MOVE TO THE EAST. AN OUTFLOW BOUNDARY DID PUSH FARTHER SOUTH INTO THE EXTREME NORTHEASTERN PORTIONS OF THE CWA...AND EXPECTED TO CONTINUE TO HEAD INTO A REGION WITH NO DECENT UPPER LEVEL SUPPORT. THEREFORE...THESE SHOWERS SHOULD DIMINISH THROUGH THE AFTERNOON HOURS AS THE MID/UPPER LOW AND UPPER JET SHIFT FARTHER EAST. MADE CHANGES TO THE GRIDS TO REFLECT CURRENT TRENDS. THE WIND SHIFT ACROSS THE NORTHEASTERN CWA FROM THE OUTFLOW BOUNDARY SHOULD ONCE AGAIN RESUME OUT OF THE SOUTHEAST THIS AFTERNOON. && .PREV DISCUSSION... /ISSUED 623 AM CDT SUN OCT 27 2013/ DISCUSSION...PLEASE SEE THE AVIATION DISCUSSION BELOW FOR MORE DETAILS. AVIATION...MVFR/IFR CIGS/VSBYS WL IMPROVE TO VFR CONDITIONS BY 17Z ACROSS MOST OF THE AREA. A WEAKENING THUNDERSTORM COMPLEX MOVING INTO THE HOUSTON AREA WL SKIRT THE VCT AREA BY 14Z. BRIEF GUSTY WINDS AND OCCASIONAL LIGHTNING WL BE POSSIBLE AT VCT. ELSEWHERE...NO SIGNIFICANT RAINFALL IS EXPECTED AS THE RESPONSIBLE UPPER LEVEL DISTURBANCE TRACKS QUICKLY NEWD. BY MIDNIGHT...MVFR CONDITIONS WL ONCE BEGIN DEVELOPING AS A MOIST FLOW PERSISTS. PREV DISCUSSION... /ISSUED 441 AM CDT SUN OCT 27 2013/ DISCUSSION...VISIBILITIES HAVE CONTINUED TO DROP ACROSS CENTRAL AREAS OF THE CWA EARLY THIS MORNING. GIVEN THE LIGHT WINDS AND RELATIVELY CLEAR SKIES...THIS TREND WL CONTINUE. AS A RESULT...WL ISSUE A DENSE FOG ADVISORY FOR MOST OF THE INTERIOR COUNTIES EXCEPT THE FAR WEST AND EXTREME NORTHEAST THROUGH 14Z. NO OTHER CHANGES NECESSARY. PREV DISCUSSION... /ISSUED 347 AM CDT SUN OCT 27 2013/ SHORT TERM (TODAY THROUGH MONDAY)...A MULTICELL CONVECTIVE CLUSTER IN ASSCTN WITH A POTENT MIDLVL S/WV WAS CURRENTLY MOVING SEWD THIS MORNING ACROSS CENTRAL AND SOUTHEAST TX. MOST OF THE MESOSCALE MODELS INCLUDING THE HRRR AND THE SYNOPTIC-SCALE MODELS INDICATE THAT THIS CLUSTER WL BEGIN WEAKENING BEFORE REACHING THE NRN PORTION OF OUR CWA LATER THIS MORNING. HOWEVER IT WL LKLY NOT TOTALLY DISSIPATE BEFORE REACHING THE NRN CWA AND WL THUS GO WITH SLIGHT CHC TO CHC POPS FOR THE 12-18Z PD. ALTHOUGH SUBSIDENCE WL PREVAIL IN THE AFTN IN THE WAKE OF THE DEPARTING S/WV...RESIDUAL MOISTURE WL LKLY BE ENOUGH TO POSSIBLY PRODUCE SOME ISOLATED SHOWERS ACROSS MAINLY ERN AREAS. LIMITED MOISTURE AND A MOSTLY SUBSIDENT AIRMASS WL KEEP THINGS DRY FOR TNT AND MON. TEMPS THROUGH THE SHORT TERM WL REMAIN AROUND 5 DEGS ABV NORMAL ON HIGHS EACH DAY...ESPECIALLY ON MON AND AROUND 7-10 DEGS ABV NORMAL FOR OVERNIGHT LOWS. LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...MID LEVEL RIDGE IS PROGD TO BE ACROSS THE GULF MON NIGHT AS A POTENT UPPER LOW DEEPENS ACROSS THE ROCKIES. THIS WILL RESULT IN A SW FLOW ALOFT OVER S TX WITH EMBEDDED SHORT WAVES TRACKING ACROSS THE AREA THROUGH MID WEEK. AM EXPECTING ABV NORMAL TEMPS ON TUE WHICH WILL BE CONDUCIVE FOR A SEA BREEZE CIRCULATION TO DVLP AND MOVE INLAND. SUFFICIENT LOW LEVEL MOISTURE WILL BE IN PLACE ON TUE AND AM EXPECTING ISOLD SHRAS ALONG THE SEA BREEZE. MID LEVEL TEMPS WILL BE TOO WARM FOR ANY DEEP CONVECTION/TSRA`S ON TUE. MOISTURE IS PROGD TO DEEPEN THROUGH WED WITH PWAT`S NEAR 2 INCHES ACROSS MUCH OF THE CWA. AN EMBEDDED SHORT WAVE COMBINED WITH A SEA BREEZE SHOULD BE ABLE TO PRODUCE ISOLD/SCT CONVECTION. KEPT THE MENTION OF TSRAS FOR WED DUE TO THE INSTABILITY BUT MID LEVEL TEMPS ARE STILL FAIRLY WARM THEREFORE DID NOT GO ANY HIGHER THAN 30 POP. BOTH THE ECMWF AND GFS PROG INCREASING POPS INTO THU BUT DIFFER ON TIMING AND STRENGTH OF A COLD FRONT AND/OR COASTAL TROF. BOTH SHOW A BDRY MVG INTO THE NW CWA ON THU BUT THE ECMWF IS FASTER AT BRINGING THROUGH THE COLD FRONT...WHILE THE GFS STALLS IT AND DOES NOT BRING THE FRONT COMPLETELY THROUGH UNTIL FRI NIGHT. DUE TO A WSW FLOW ALOFT ON THU...AM EXPECTING THE FRONT TO HAVE A HARD TIME PUSHING THROUGH S TX INITIALLY. AM EXPECTING A COASTAL TROF TO DVLP LEADING TO A NELY FLOW ACROSS THE CWA ON THU WITH THE ACTUAL FRONT STALLING JUST N OR ACROSS THE NRN TIER OF THE CWA. THE FRONTAL BDRY LOSES ITS DEFINITION THROUGH FRI WHILE THE COASTAL TROF LIFTS NE...THUS LEADING TO A MODIFIED AIRMASS ACROSS S TX ON FRI THAT IS SLIGHTLY COOLER AND DRIER. THEN AN UPPER LEVEL LONG WAVE TROF IS PROGD TO TRACK E ACROSS THE PLAINS WHICH WILL HELP PUSH REINFORCING HIGH PRESSURE INTO S TX BY FRI OR FRI NIGHT WITH EVEN DRIER AND COOLER AIR FILTERING INTO S TX THROUGH SAT. WITH THIS SCENARIO...POPS WILL BE HIGHEST ON THU THEN DECREASING ON FRI FROM N TO S. DID NOT WANT TO GO ANY HIGHER THAN 40 PERCENT ON THU/THU NIGHT UNTIL CONFIDENCE IN MODEL SOLNS IS BETTER. MARINE...A CONTINUED RELAXING OF THE GRADIENT IN THE SRN/CENTRAL GULF WL CONTINUE TO SUBSIDE THE INCOMING SWELLS. THIS WL IN TURN LOWER THE RIP CURRENT THREAT TO MODERATE TODAY. RESIDUAL SWELLS AND INCREASING PRESSURE GRADIENT WL MAINTAIN THE MODERATE THREAT FOR RIP CURRENTS ON MONDAY AS WELL. SMALL CRAFT CAUTION CONDITIONS FOR THE NEARSHORE AND OFFSHORE WATERS TODAY WL BE DUE TO SWELLS. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 87 71 87 73 87 / 10 10 10 10 20 VICTORIA 85 66 86 69 86 / 30 10 10 10 20 LAREDO 91 72 92 74 92 / 10 10 10 10 10 ALICE 88 69 89 71 89 / 10 10 10 10 20 ROCKPORT 85 73 86 74 85 / 20 10 10 10 10 COTULLA 87 69 89 71 88 / 10 10 10 10 20 KINGSVILLE 87 70 88 72 89 / 10 10 10 10 20 NAVY CORPUS 84 74 85 77 85 / 10 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ CB/85...SHORT TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
623 AM CDT SUN OCT 27 2013 .DISCUSSION...PLEASE SEE THE AVIATION DISCUSSION BELOW FOR MORE DETAILS. && .AVIATION...MVFR/IFR CIGS/VSBYS WL IMPROVE TO VFR CONDITIONS BY 17Z ACROSS MOST OF THE AREA. A WEAKENING THUNDERSTORM COMPLEX MOVING INTO THE HOUSTON AREA WL SKIRT THE VCT AREA BY 14Z. BRIEF GUSTY WINDS AND OCCASIONAL LIGHTNING WL BE POSSIBLE AT VCT. ELSEWHERE...NO SIGNIFICANT RAINFALL IS EXPECTED AS THE RESPONSIBLE UPPER LEVEL DISTURBANCE TRACKS QUICKLY NEWD. BY MIDNIGHT...MVFR CONDITIONS WL ONCE BEGIN DEVELOPING AS A MOIST FLOW PERSISTS. && .PREV DISCUSSION... /ISSUED 441 AM CDT SUN OCT 27 2013/ DISCUSSION...VISIBILITIES HAVE CONTINUED TO DROP ACROSS CENTRAL AREAS OF THE CWA EARLY THIS MORNING. GIVEN THE LIGHT WINDS AND RELATIVELY CLEAR SKIES...THIS TREND WL CONTINUE. AS A RESULT...WL ISSUE A DENSE FOG ADVISORY FOR MOST OF THE INTERIOR COUNTIES EXCEPT THE FAR WEST AND EXTREME NORTHEAST THROUGH 14Z. NO OTHER CHANGES NECESSARY. PREV DISCUSSION... /ISSUED 347 AM CDT SUN OCT 27 2013/ SHORT TERM (TODAY THROUGH MONDAY)...A MULTICELL CONVECTIVE CLUSTER IN ASSCTN WITH A POTENT MIDLVL S/WV WAS CURRENTLY MOVING SEWD THIS MORNING ACROSS CENTRAL AND SOUTHEAST TX. MOST OF THE MESOSCALE MODELS INCLUDING THE HRRR AND THE SYNOPTIC-SCALE MODELS INDICATE THAT THIS CLUSTER WL BEGIN WEAKENING BEFORE REACHING THE NRN PORTION OF OUR CWA LATER THIS MORNING. HOWEVER IT WL LKLY NOT TOTALLY DISSIPATE BEFORE REACHING THE NRN CWA AND WL THUS GO WITH SLIGHT CHC TO CHC POPS FOR THE 12-18Z PD. ALTHOUGH SUBSIDENCE WL PREVAIL IN THE AFTN IN THE WAKE OF THE DEPARTING S/WV...RESIDUAL MOISTURE WL LKLY BE ENOUGH TO POSSIBLY PRODUCE SOME ISOLATED SHOWERS ACROSS MAINLY ERN AREAS. LIMITED MOISTURE AND A MOSTLY SUBSIDENT AIRMASS WL KEEP THINGS DRY FOR TNT AND MON. TEMPS THROUGH THE SHORT TERM WL REMAIN AROUND 5 DEGS ABV NORMAL ON HIGHS EACH DAY...ESPECIALLY ON MON AND AROUND 7-10 DEGS ABV NORMAL FOR OVERNIGHT LOWS. LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...MID LEVEL RIDGE IS PROGD TO BE ACROSS THE GULF MON NIGHT AS A POTENT UPPER LOW DEEPENS ACROSS THE ROCKIES. THIS WILL RESULT IN A SW FLOW ALOFT OVER S TX WITH EMBEDDED SHORT WAVES TRACKING ACROSS THE AREA THROUGH MID WEEK. AM EXPECTING ABV NORMAL TEMPS ON TUE WHICH WILL BE CONDUCIVE FOR A SEA BREEZE CIRCULATION TO DVLP AND MOVE INLAND. SUFFICIENT LOW LEVEL MOISTURE WILL BE IN PLACE ON TUE AND AM EXPECTING ISOLD SHRAS ALONG THE SEA BREEZE. MID LEVEL TEMPS WILL BE TOO WARM FOR ANY DEEP CONVECTION/TSRA`S ON TUE. MOISTURE IS PROGD TO DEEPEN THROUGH WED WITH PWAT`S NEAR 2 INCHES ACROSS MUCH OF THE CWA. AN EMBEDDED SHORT WAVE COMBINED WITH A SEA BREEZE SHOULD BE ABLE TO PRODUCE ISOLD/SCT CONVECTION. KEPT THE MENTION OF TSRAS FOR WED DUE TO THE INSTABILITY BUT MID LEVEL TEMPS ARE STILL FAIRLY WARM THEREFORE DID NOT GO ANY HIGHER THAN 30 POP. BOTH THE ECMWF AND GFS PROG INCREASING POPS INTO THU BUT DIFFER ON TIMING AND STRENGTH OF A COLD FRONT AND/OR COASTAL TROF. BOTH SHOW A BDRY MVG INTO THE NW CWA ON THU BUT THE ECMWF IS FASTER AT BRINGING THROUGH THE COLD FRONT...WHILE THE GFS STALLS IT AND DOES NOT BRING THE FRONT COMPLETELY THROUGH UNTIL FRI NIGHT. DUE TO A WSW FLOW ALOFT ON THU...AM EXPECTING THE FRONT TO HAVE A HARD TIME PUSHING THROUGH S TX INITIALLY. AM EXPECTING A COASTAL TROF TO DVLP LEADING TO A NELY FLOW ACROSS THE CWA ON THU WITH THE ACTUAL FRONT STALLING JUST N OR ACROSS THE NRN TIER OF THE CWA. THE FRONTAL BDRY LOSES ITS DEFINITION THROUGH FRI WHILE THE COASTAL TROF LIFTS NE...THUS LEADING TO A MODIFIED AIRMASS ACROSS S TX ON FRI THAT IS SLIGHTLY COOLER AND DRIER. THEN AN UPPER LEVEL LONG WAVE TROF IS PROGD TO TRACK E ACROSS THE PLAINS WHICH WILL HELP PUSH REINFORCING HIGH PRESSURE INTO S TX BY FRI OR FRI NIGHT WITH EVEN DRIER AND COOLER AIR FILTERING INTO S TX THROUGH SAT. WITH THIS SCENARIO...POPS WILL BE HIGHEST ON THU THEN DECREASING ON FRI FROM N TO S. DID NOT WANT TO GO ANY HIGHER THAN 40 PERCENT ON THU/THU NIGHT UNTIL CONFIDENCE IN MODEL SOLNS IS BETTER. MARINE...A CONTINUED RELAXING OF THE GRADIENT IN THE SRN/CENTRAL GULF WL CONTINUE TO SUBSIDE THE INCOMING SWELLS. THIS WL IN TURN LOWER THE RIP CURRENT THREAT TO MODERATE TODAY. RESIDUAL SWELLS AND INCREASING PRESSURE GRADIENT WL MAINTAIN THE MODERATE THREAT FOR RIP CURRENTS ON MONDAY AS WELL. SMALL CRAFT CAUTION CONDITIONS FOR THE NEARSHORE AND OFFSHORE WATERS TODAY WL BE DUE TO SWELLS. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 87 71 87 73 87 / 10 10 10 10 20 VICTORIA 85 66 86 69 86 / 30 10 10 10 20 LAREDO 91 72 92 74 92 / 10 10 10 10 10 ALICE 88 69 89 71 89 / 10 10 10 10 20 ROCKPORT 85 73 86 74 85 / 20 10 10 10 10 COTULLA 87 69 89 71 88 / 20 10 10 10 20 KINGSVILLE 88 70 88 72 89 / 10 10 10 10 20 NAVY CORPUS 84 74 85 77 85 / 10 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: BEE...DUVAL...GOLIAD...JIM WELLS...KLEBERG...LIVE OAK...MCMULLEN...NUECES...SAN PATRICIO. GM...NONE. && $$ MB
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
441 AM CDT SUN OCT 27 2013 .DISCUSSION...VISIBILITIES HAVE CONTINUED TO DROP ACROSS CENTRAL AREAS OF THE CWA EARLY THIS MORNING. GIVEN THE LIGHT WINDS AND RELATIVELY CLEAR SKIES...THIS TREND WL CONTINUE. AS A RESULT...WL ISSUE A DENSE FOG ADVISORY FOR MOST OF THE INTERIOR COUNTIES EXCEPT THE FAR WEST AND EXTREME NORTHEAST THROUGH 14Z. NO OTHER CHANGES NECESSARY. && .PREV DISCUSSION... /ISSUED 347 AM CDT SUN OCT 27 2013/ SHORT TERM (TODAY THROUGH MONDAY)...A MULTICELL CONVECTIVE CLUSTER IN ASSCTN WITH A POTENT MIDLVL S/WV WAS CURRENTLY MOVING SEWD THIS MORNING ACROSS CENTRAL AND SOUTHEAST TX. MOST OF THE MESOSCALE MODELS INCLUDING THE HRRR AND THE SYNOPTIC-SCALE MODELS INDICATE THAT THIS CLUSTER WL BEGIN WEAKENING BEFORE REACHING THE NRN PORTION OF OUR CWA LATER THIS MORNING. HOWEVER IT WL LKLY NOT TOTALLY DISSIPATE BEFORE REACHING THE NRN CWA AND WL THUS GO WITH SLIGHT CHC TO CHC POPS FOR THE 12-18Z PD. ALTHOUGH SUBSIDENCE WL PREVAIL IN THE AFTN IN THE WAKE OF THE DEPARTING S/WV...RESIDUAL MOISTURE WL LKLY BE ENOUGH TO POSSIBLY PRODUCE SOME ISOLATED SHOWERS ACROSS MAINLY ERN AREAS. LIMITED MOISTURE AND A MOSTLY SUBSIDENT AIRMASS WL KEEP THINGS DRY FOR TNT AND MON. TEMPS THROUGH THE SHORT TERM WL REMAIN AROUND 5 DEGS ABV NORMAL ON HIGHS EACH DAY...ESPECIALLY ON MON AND AROUND 7-10 DEGS ABV NORMAL FOR OVERNIGHT LOWS. LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...MID LEVEL RIDGE IS PROGD TO BE ACROSS THE GULF MON NIGHT AS A POTENT UPPER LOW DEEPENS ACROSS THE ROCKIES. THIS WILL RESULT IN A SW FLOW ALOFT OVER S TX WITH EMBEDDED SHORT WAVES TRACKING ACROSS THE AREA THROUGH MID WEEK. AM EXPECTING ABV NORMAL TEMPS ON TUE WHICH WILL BE CONDUCIVE FOR A SEA BREEZE CIRCULATION TO DVLP AND MOVE INLAND. SUFFICIENT LOW LEVEL MOISTURE WILL BE IN PLACE ON TUE AND AM EXPECTING ISOLD SHRAS ALONG THE SEA BREEZE. MID LEVEL TEMPS WILL BE TOO WARM FOR ANY DEEP CONVECTION/TSRA`S ON TUE. MOISTURE IS PROGD TO DEEPEN THROUGH WED WITH PWAT`S NEAR 2 INCHES ACROSS MUCH OF THE CWA. AN EMBEDDED SHORT WAVE COMBINED WITH A SEA BREEZE SHOULD BE ABLE TO PRODUCE ISOLD/SCT CONVECTION. KEPT THE MENTION OF TSRAS FOR WED DUE TO THE INSTABILITY BUT MID LEVEL TEMPS ARE STILL FAIRLY WARM THEREFORE DID NOT GO ANY HIGHER THAN 30 POP. BOTH THE ECMWF AND GFS PROG INCREASING POPS INTO THU BUT DIFFER ON TIMING AND STRENGTH OF A COLD FRONT AND/OR COASTAL TROF. BOTH SHOW A BDRY MVG INTO THE NW CWA ON THU BUT THE ECMWF IS FASTER AT BRINGING THROUGH THE COLD FRONT...WHILE THE GFS STALLS IT AND DOES NOT BRING THE FRONT COMPLETELY THROUGH UNTIL FRI NIGHT. DUE TO A WSW FLOW ALOFT ON THU...AM EXPECTING THE FRONT TO HAVE A HARD TIME PUSHING THROUGH S TX INITIALLY. AM EXPECTING A COASTAL TROF TO DVLP LEADING TO A NELY FLOW ACROSS THE CWA ON THU WITH THE ACTUAL FRONT STALLING JUST N OR ACROSS THE NRN TIER OF THE CWA. THE FRONTAL BDRY LOSES ITS DEFINITION THROUGH FRI WHILE THE COASTAL TROF LIFTS NE...THUS LEADING TO A MODIFIED AIRMASS ACROSS S TX ON FRI THAT IS SLIGHTLY COOLER AND DRIER. THEN AN UPPER LEVEL LONG WAVE TROF IS PROGD TO TRACK E ACROSS THE PLAINS WHICH WILL HELP PUSH REINFORCING HIGH PRESSURE INTO S TX BY FRI OR FRI NIGHT WITH EVEN DRIER AND COOLER AIR FILTERING INTO S TX THROUGH SAT. WITH THIS SCENARIO...POPS WILL BE HIGHEST ON THU THEN DECREASING ON FRI FROM N TO S. DID NOT WANT TO GO ANY HIGHER THAN 40 PERCENT ON THU/THU NIGHT UNTIL CONFIDENCE IN MODEL SOLNS IS BETTER. MARINE...A CONTINUED RELAXING OF THE GRADIENT IN THE SRN/CENTRAL GULF WL CONTINUE TO SUBSIDE THE INCOMING SWELLS. THIS WL IN TURN LOWER THE RIP CURRENT THREAT TO MODERATE TODAY. RESIDUAL SWELLS AND INCREASING PRESSURE GRADIENT WL MAINTAIN THE MODERATE THREAT FOR RIP CURRENTS ON MONDAY AS WELL. SMALL CRAFT CAUTION CONDITIONS FOR THE NEARSHORE AND OFFSHORE WATERS TODAY WL BE DUE TO SWELLS. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 87 71 87 73 87 / 10 10 10 10 20 VICTORIA 85 66 86 69 86 / 30 10 10 10 20 LAREDO 91 72 92 74 92 / 10 10 10 10 10 ALICE 88 69 89 71 89 / 10 10 10 10 20 ROCKPORT 85 73 86 74 85 / 20 10 10 10 10 COTULLA 87 69 89 71 88 / 20 10 10 10 20 KINGSVILLE 88 70 88 72 89 / 10 10 10 10 20 NAVY CORPUS 84 74 85 77 85 / 10 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: BEE...DUVAL...GOLIAD...JIM WELLS...KLEBERG...LIVE OAK...MCMULLEN...NUECES...SAN PATRICIO. GM...NONE. && $$ MB/80...SHORT TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
347 AM CDT SUN OCT 27 2013 .SHORT TERM (TODAY THROUGH MONDAY)...A MULTICELL CONVECTIVE CLUSTER IN ASSCTN WITH A POTENT MIDLVL S/WV WAS CURRENTLY MOVING SEWD THIS MORNING ACROSS CENTRAL AND SOUTHEAST TX. MOST OF THE MESOSCALE MODELS INCLUDING THE HRRR AND THE SYNOPTIC-SCALE MODELS INDICATE THAT THIS CLUSTER WL BEGIN WEAKENING BEFORE REACHING THE NRN PORTION OF OUR CWA LATER THIS MORNING. HOWEVER IT WL LKLY NOT TOTALLY DISSIPATE BEFORE REACHING THE NRN CWA AND WL THUS GO WITH SLIGHT CHC TO CHC POPS FOR THE 12-18Z PD. ALTHOUGH SUBSIDENCE WL PREVAIL IN THE AFTN IN THE WAKE OF THE DEPARTING S/WV...RESIDUAL MOISTURE WL LKLY BE ENOUGH TO POSSIBLY PRODUCE SOME ISOLATED SHOWERS ACROSS MAINLY ERN AREAS. LIMITED MOISTURE AND A MOSTLY SUBSIDENT AIRMASS WL KEEP THINGS DRY FOR TNT AND MON. TEMPS THROUGH THE SHORT-TERM WL REMAIN AROUND 5 DEGS ABV NORMAL ON HIGHS EACH DAY...ESPECIALLY ON MON AND AROUND 7-10 DEGS ABV NORMAL FOR OVERNIGHT LOWS. && .LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...MID LEVEL RIDGE IS PROGD TO BE ACROSS THE GULF MON NIGHT AS A POTENT UPPER LOW DEEPENS ACROSS THE ROCKIES. THIS WILL RESULT IN A SW FLOW ALOFT OVER S TX WITH EMBEDDED SHORT WAVES TRACKING ACROSS THE AREA THROUGH MID WEEK. AM EXPECTING ABV NORMAL TEMPS ON TUE WHICH WILL BE CONDUCIVE FOR A SEA BREEZE CIRCULATION TO DVLP AND MOVE INLAND. SUFFICIENT LOW LEVEL MOISTURE WILL BE IN PLACE ON TUE AND AM EXPECTING ISOLD SHRAS ALONG THE SEA BREEZE. MID LEVEL TEMPS WILL BE TOO WARM FOR ANY DEEP CONVECTION/TSRA`S ON TUE. MOISTURE IS PROGD TO DEEPEN THROUGH WED WITH PWAT`S NEAR 2 INCHES ACROSS MUCH OF THE CWA. AN EMBEDDED SHORT WAVE COMBINED WITH A SEA BREEZE SHOULD BE ABLE TO PRODUCE ISOLD/SCT CONVECTION. KEPT THE MENTION OF TSRAS FOR WED DUE TO THE INSTABILITY BUT MID LEVEL TEMPS ARE STILL FAIRLY WARM THEREFORE DID NOT GO ANY HIGHER THAN 30 POP. BOTH THE ECMWF AND GFS PROG INCREASING POPS INTO THU BUT DIFFER ON TIMING AND STRENGTH OF A COLD FRONT AND/OR COASTAL TROF. BOTH SHOW A BDRY MVG INTO THE NW CWA ON THU BUT THE ECMWF IS FASTER AT BRINGING THROUGH THE COLD FRONT...WHILE THE GFS STALLS IT AND DOES NOT BRING THE FRONT COMPLETELY THROUGH UNTIL FRI NIGHT. DUE TO A WSW FLOW ALOFT ON THU...AM EXPECTING THE FRONT TO HAVE A HARD TIME PUSHING THROUGH S TX INITIALLY. AM EXPECTING A COASTAL TROF TO DVLP LEADING TO A NELY FLOW ACROSS THE CWA ON THU WITH THE ACTUAL FRONT STALLING JUST N OR ACROSS THE NRN TIER OF THE CWA. THE FRONTAL BDRY LOSES ITS DEFINITION THROUGH FRI WHILE THE COASTAL TROF LIFTS NE...THUS LEADING TO A MODIFIED AIRMASS ACROSS S TX ON FRI THAT IS SLIGHTLY COOLER AND DRIER. THEN AN UPPER LEVEL LONG WAVE TROF IS PROGD TO TRACK E ACROSS THE PLAINS WHICH WILL HELP PUSH REINFORCING HIGH PRESSURE INTO S TX BY FRI OR FRI NIGHT WITH EVEN DRIER AND COOLER AIR FILTERING INTO S TX THROUGH SAT. WITH THIS SCENARIO...POPS WILL BE HIGHEST ON THU THEN DECREASING ON FRI FROM N TO S. DID NOT WANT TO GO ANY HIGHER THAN 40 PERCENT ON THU/THU NIGHT UNTIL CONFIDENCE IN MODEL SOLNS IS BETTER. && .MARINE...A CONTINUED RELAXING OF THE GRADIENT IN THE SRN/CENTRAL GULF WL CONTINUE TO SUBSIDE THE INCOMING SWELLS. THIS WL IN TURN LOWER THE RIP CURRENT THREAT TO MODERATE TODAY. RESIDUAL SWELLS AND INCREASING PRESSURE GRADIENT WL MAINTAIN THE MODERATE THREAT FOR RIP CURRENTS ON MONDAY AS WELL. SMALL CRAFT CAUTION CONDITIONS FOR THE NEARSHORE AND OFFSHORE WATERS TODAY WL BE DUE TO SWELLS. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 87 71 87 73 87 / 10 10 10 10 20 VICTORIA 85 66 86 69 86 / 30 10 10 10 20 LAREDO 91 72 92 74 92 / 10 10 10 10 10 ALICE 88 69 89 71 89 / 10 10 10 10 20 ROCKPORT 85 73 86 74 85 / 20 10 10 10 10 COTULLA 87 69 89 71 88 / 20 10 10 10 20 KINGSVILLE 88 70 88 72 89 / 10 10 10 10 20 NAVY CORPUS 84 74 85 77 85 / 10 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ MB/80...SHORT TERM TE/81...LONG TERM
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1255 AM CDT SUN OCT 27 2013 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...VFR THROUGH THE PERIOD. WILL EXPERIENCE FEW-SCT CIGS OVERNIGHT AROUND 3K FEET. THEN GUSTY WINDS BEGINNING IN THE LATE MORNING AND AFTERNOON HOURS. MID CLOUDS WILL INCREASE TOMORROW AFTERNOON WITH CIGS AROUND 10K FEET. WINDS WILL DECREASE AFTER SUNSET. && .PREV DISCUSSION... /ISSUED 624 PM CDT SAT OCT 26 2013/ DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. AVIATION...SCT TO BKN DECK BEGINNING TO THIN OUT THIS EVENING WITH LOSS OF DAYTIME HEATING. INLAND CIGS AROUND 6000...WITH HIGHER CIGS AROUND 10000 AT KBRO. SKIES WILL BECOME SKC OVERNIGHT AND CONTINUE INTO TOMORROW MORNING. SOUTHEAST WINDS DECREASE TO NEAR CALM WITHIN THE NEXT COUPLE HOURS. SOUTHEAST FLOW RETURN TO 10 TO 12 KNOTS BEFORE NOON TOMORROW...WHILE SCT TO BRIEFLY BKN CIGS AT 4000 TO 5000 REDEVELOP BY NOON AND SPREAD INLAND. PREV DISCUSSION... /ISSUED 300 PM CDT SAT OCT 26 2013/ SHORT TERM.../NOW THROUGH SUNDAY NIGHT/... A WEAK SHORTWAVE MOVING SOUTHEAST ACROSS OKLAHOMA AND NORTHERN TEXAS WILL HELP PUSH THE PERSISTENT HIGH PRESSURE OVER THE SOUTHERN PLAINS EASTWARD WITH ITS CENTERED OVER THE FLORIDA PANHANDLE. THIS WILL SHIFT THE UPPER LEVEL FLOW MORE SOUTHEASTERLY THE REST OF TODAY AND TONIGHT. AS THIS WAVE MOVES EASTWARD...SOUTHEAST WINDS WILL REMAIN LIGHT TONIGHT WITH SCATTERED CLOUDS DUE TO THE MOISTURE COMING FROM THE SOUTH INCREASING CLOSE TO THE SURFACE. KBRO 12Z SOUNDING SHOW THE SLOW INCREASE OF PWATS REACHING 1.32 INCHES THIS MORNING. AS THE ABUNDANT DRY AIR RAP AROUND THE PERIPHERY OF THE HIGH CONTINUES TO MOVE INLAND WITH THE E/SE FLOW...THE CHANCE OF SHOWERS REMAIN VERY LOW WITH A SILENT 10 ACROSS THE CWA TONIGHT AND SUNDAY. ISOLATED SHOWERS WILL BE POSSIBLE BUT REMAIN BRIEF WITH NO SIGNIFICANT RAINFALL EXPECTED TONIGHT AND SUNDAY. AS THE CLOUD COVERAGE INCREASES TONIGHT...LOW TEMPERATURES WILL BE IN THE WARMER TREND THROUGH THE NIGHT REACHING THE 70S ALONG THE RIVER AND THE UPPER 60S OVER THE NORTHERN RANCHLAND. INTO SUNDAY AND SUNDAY NIGHT...THE WINDS WILL REMAIN LIGHTER THAN TODAY WITH RIDGE BUILDING FROM THE WEST AND PERSISTENT SOUTHEAST FLOW ACROSS THE GULF. THE MOISTURE CONTENT IN THE LOWER LEVEL WILL CONTINUE TO INCREASE BUT THE 1000-500 MB RH SHOW THE LOW LEVEL MOISTURE IN THE 40 PERCENT LEVEL BETWEEN THE GFS AND THE NAM MODELS. THE LOW LEVEL MOISTURE IN THE AREA WILL LIMIT THE RAINFALL POTENTIAL WITH A FEW SHOWERS POSSIBLE MAINLY ALONG THE COAST. TEMPERATURES WILL WARM UP INTO THE MID TO UPPER 80S WITH A FEW LOCATIONS IN THE UPPER VALLEY NEARLY REACHING THE 90 DEGREES. NO SIGNIFICANT CHANGE EXPECTED THROUGH THE NIGHT AND LOW TEMPERATURES WILL REACH THE MID TO LOW 70S ACROSS THE MID AND LOWER VALLEY WITH MOST OF THE NORTHERN PORTION OF THE CWA IN THE MID 60S. LONG TERM.../MONDAY THROUGH SATURDAY/...LITTLE CHANGE IN MODEL AND FORECAST THINKING FOR THIS LONG TERM PACKAGE. THIS WILL BE A REHASH OF THE PREVIOUS FORECAST WITH LITTLE TO NO CHANGES WITH STILL A WIDE SPREAD BETWEEN TIMING OF THE MEDIUM RANGE MODELS. MAIN ELEMENTS OF CONCERN CONTINUE TO BE INCREASING SE-S WIND MONDAY THROUGH WEDNESDAY WITH PEAK WINDS TUES/WED. ALSO...TEMPERATURES CONTINUE TO INCREASE EACH DAY AS SOUTHERLY FLOW DEEPENS AND EVENTUALLY VEERS A BIT WEST OF SOUTH AHEAD OF THE APPROACHING UPPER TROUGH. AS MENTIONED LITTLE CHANGE WAS MADE TO THE INHERITED GRIDS. UPPER TROUGH OFF THE PACIFIC COAST TO MAKE SLOW EASTWARD PROGRESS THROUGH THE WEEK. SOUTH TEXAS TO LIE ON THE WESTERN END OF WARM SUBTROPICAL RIDGE. MODEL CONSENSUS REMAINS IN THE ECMWF/CANADIAN CAMP WITH A SLOWER EASTWARD MOVEMENT. HIGH PRESSURE RIDGE BUILDS OVER THE PACIFIC NORTHWEST WITH THE UPPER TROUGH TO SINK MORE SOUTH THEN KICK EAST INITIALLY. THE CLOSE TROUGH IS PROGGED TO OPEN UP INTO A POSITIVELY TILTED TROUGH THURSDAY LIFT NORTHEAST WELL NORTH OF TEXAS. THE FLOW OVER NORTHWEST MEXICO AND DEEP SOUTH TEXAS BECOMES INCREASINGLY ZONAL TO EVEN SOUTHWEST. THIS IS NOT VERY CONDUCIVE FOR FRONT PASSAGES. THE LATEST GFS MOS TEMPERATURES GUIDANCE AS WELL AS THE 00Z ECMWF ONLY SHOW A 3 TO 5 DEGREE DROP IN TEMPERATURES BEHIND A LATE THURSDAY/FRIDAY FRONT WHICH IS NOT EVEN APPROACHING SEASONAL NORMALS FOR NOVEMBER. PRESSURE GRADIENT BEGINS TO STRENGTHEN MONDAY MAINLY DUE TO GULF OF MEXICO RIDGE AND SOME WEAK LEE TROUGH OVER THE SIERRA MADRE. GFS IS TRENDING A BIT STRONG NEARING 30 MPH BETWEEN HWY 69E/69C BUT WILL TREND IN THE BREEZY /15-25MPH/ RANGE AND HOLD OFF ON THE WINDY /20-30/UNTIL TUESDAY AND WEDNESDAY AS THE TROUGH MOVES FARTHER EAST. 925-850MB WINDS JUST SLIGHTLY LOWER BUT STILL DECENT IN THE 35-45 KNOT RANGE DEPENDING ON MODEL OF CHOICE. AS FOR TEMPERATURES SAME THINKING WELL ABOVE NORMAL WITH SOUTH WINDS AND INCREASING HEIGHTS AND THICKNESS AHEAD OF THE UPPER TROUGH. EXPECT ANOMALIES TO REACH 10-15 DEGREES ABOVE NORMAL. POST TROUGH/FRONT AS MENTIONED ONLY A 3 TO 5 DEGREE DROP IS INDICATED AT THIS TIME. ONE ELEMENT OF NOTE IS THE INCREASE IN MOISTURE. SOUTHERLY FLOW TO PUMP IN GULF MOISTURE THROUGH THE COMING WEEK. PWATS ARE ADVERTISED TO JUMP ABOVE THE 1.5 THRESHOLD TUESDAY AND 2 INCHES WEDNESDAY. THE DEEPER MOISTURE WILL MAKE IN FEEL MUCH MORE HUMID BUT SHOWER ACTIVITY WILL BE LIMITED AT BEST ON WEDNESDAY WITH A BIT TOO MUCH WIND AND NOT THE BEST DIRECTION FOR AN ACTIVE SEA BREEZE. QUESTION ARISES FOR THURSDAY AND FRIDAY AS THE UPPER TROUGH AND FRONT APPROACH. GUIDANCE FAVORS HIGHER END CHANCE POPS BUT WILL MAINTAIN LOWER END WITH UNCERTAINTY IN TIMING AND STRENGTH. MARINE...NOW THROUGH SUNDAY NIGHT...A PERSISTENT HIGH PRESSURE OVER THE NORTHERN GULF OF MEXICO WILL KEEP AN EASTERLY ONSHORE FLOW FOR MOST OF THE SHORT TERM FORECAST. DUE TO THE LONG EASTERLY FETCH ACROSS THE GULF WATERS...THE SEAS WILL CONTINUE TO BUILD UP TO ADVISORY CRITERIA THROUGH THE NIGHT. A SMALL CRAFT ADVISORY IS IN EFFECT FOR GULF WATERS THROUGH TONIGHT WITH A COASTAL FLOOD STATEMENT AS THE SURF WATERS MOVES CLOSE TO THE DUNES. THE SEAS WILL REMAIN HIGH THROUGH THE DAY WITH BREEZE CONDITIONS GRADUALLY LOWERING INTO SUNDAY. SINCE TIDES HAVE BEEN 1FOOT ABOVE PREDICTED...WITH HIGH TIDE TONIGHT...EXPECT THE WATERS TO PUSH UP TO THE DUNE ONCE AGAIN TONIGHT. THIS WILL NOT CAUSE FLOODING BUT WILL FORCE FOR SOME BEACH ACCESS TO BE CLOSE. THERE IS A HIGH RIP CURRENT RISK DUE TO THE EASTERLY ONSHORE FLOW THROUGH SUNDAY EVENING. MONDAY THROUGH THURSDAY SOUTHEAST FLOW TO BEGIN TO STRENGTHEN MONDAY BECOMING STRONG TUESDAY INTO EARLY THURSDAY. SMALL CRAFT ADVISORIES ARE BECOMING MORE LIKELY AND POSSIBLY FOR AN EXTENDED MONDAY THROUGH THURSDAY PERIOD. SCA/S WILL BE MORE PREVALENT ACROSS THE LAGUNA MADRE DURING THE DAYTIME AND OFFSHORE AT NIGHT. AS THE STRONGEST GRADIENT DEVELOPS WEDNESDAY NIGHT STRONGER SCA CRITERIA WINDS COULD LINGER OVER THE LAGUNA WELL INTO THE EVENING HOURS. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...HIGH RIP CURRENT RISK UNTIL NOON CDT TODAY FOR TXZ251-256-257. COASTAL FLOOD ADVISORY UNTIL NOON CDT TODAY FOR TXZ251-256-257. GM...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 55
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1116 PM CDT SAT OCT 26 2013 .DISCUSSION... UPDATED AVIATION DISCUSSION. && .AVIATION... MAIN ISSUE WILL BE TIMING BAND OF SHOWERS AND THUNDERSTORMS WORKING ITS WAY FROM NORTH TO SOUTH ACROSS THE AREA. CLL WILL BE IMPACTED FIRST WILL FAIRLY IMPRESSIVE CELL TIMED TO COME NEAR THE AIRFIELD AROUND 06Z. MORE SHOWERS AND THUNDERSTORMS TO FOLLOW WITH MCS NOW DROPPING THROUGH NE TEXAS. TIMING ADJUSTMENTS HAVE BEEN MADE...GENERALLY MOVING UP THE TIMING BY AN HOUR OR TWO AT EACH TAF SITE...WITH A 2 OR 3 HOUR DURATION OF THUNDER. THIS IS CONSISTENT WITH MOST MESOSCALE MODELS INCLUDING THE LATEST RAPID REFRESH WHICH SEEMS TO HAVE A GOOD HANDLE ON THINGS. && .PREV DISCUSSION... /ISSUED 924 PM CDT SAT OCT 26 2013/ UPDATE... SEE DISCUSSION FOR EVENING UPDATE. DISCUSSION... SHORTWAVE MOVING TOWARDS THE SOUTHEAST THIS EVENING WITH AN MCS PUSHING TOWARDS THE SOUTH SLOWLY. DISCRETE CELLS OUT IN FRONT OF THE MCS HAVE BEEN PUSHING EASTWARDS TONIGHT AND WEAKENING AS THEY APPROACH THE CWA. STILL COULD SEE SOME RAIN FROM THESE CELLS LATER TONIGHT BEFORE THE MAIN MCS PUSHES INTO THE AREA. THE HRRR AND TEXAS TECH WRF HAVE BEEN SHOWING THE MCS MAKING IT INTO OUR FAR NORTHERN ZONES BY 6Z OR JUST AFTER MIDNIGHT. BY DAYBREAK THE REMNANTS OF THE MCS WILL BE APPROACHING THE COAST. MADE TWEAKS TO THE POP GRIDS TO ACCOUNT FOR THIS. CLOUD COVER ALSO APPEARS THAT IT WILL HANG AROUND TOMORROW. LOWERED HIGH TEMPERATURE GRIDS A TAD FOR TOMORROW TO ACCOUNT FOR THIS. 23 PREV DISCUSSION... /ISSUED 654 PM CDT SAT OCT 26 2013/ DISCUSSION... UPDATED AVIATION DISCUSSION. AVIATION... EAST WEST LINE OF STORMS NOW OVER NORTHERN TEXAS IS PROGGED BY HIGHER RESOLUTION MODELS TO SAG SOUTH TONIGHT...CROSSING THE TAF SITES FROM NORTH TO SOUTH...OVERNIGHT AND SUNDAY MORNING. CLUSTER OF STORMS IN ADVANCE OF THAT LINE WILL LIKELY DISSIPATE WITH LOSS OF DAYTIME HEATING OR POSSIBLY MERGE WITH THE LINE COMING DOWN FROM THE NORTH. AS FAR AS TIMING EXPECTING IT TO REACH CLL AND UTS BETWEEN 06Z AND 08Z...CXO CLOSER TO 10Z...IAH AROUND 12Z...AND HOU AND SGR 13-14Z. SHOULD SEE A 3 TO 4 HOUR PERIOD OF RAIN WITH THIS BAND. NOT SURE ABOUT THE IMPACTS FOR LBX AND GLS...AS LINE WILL BE PRETTY FAR REMOVED FROM THE UPPER VORT THAT IS HELPING TO TRIGGER THIS LINE...BUT HAVE INCLUDED A PERIOD OF SHOWERS AND STORMS UNDER THE ASSUMPTION THAT THE LINE HOLDS TOGETHER. AFTER LINE PASSES COULD SEE A FEW HOURS OF VARIABLE WINDS...THEN SW TO S WINDS SHOULD BECOME REESTABLISHED. WILL LIKELY SEE A PERIOD OF MVFR CONDITIONS AROUND THE TIME OF PASSAGE OF THIS BAND. 46 PREV DISCUSSION... /ISSUED 334 PM CDT SAT OCT 26 2013/ DISCUSSION... SEEING ISO/WIDELY SCT DEVELOPMENT OVER SC TX THIS AFTN WITH DEEP- ENING LOW LEVEL MOISTURE/DAYTIME HEATING...ALL AHEAD OF THE SHORT WAVE PROGGED FOR TONIGHT. MODELS IN DECENT AGREEMENT WITH TIMING/ MOVEMENT OF THIS EXPECTED ACTIVITY. POPS SHOULD DECREASE FROM THE W/NW BY SUN AFTN AS THE DISTURBANCE MOVES OUT OF THE AREA. THE OFFSHORE FLOW IN THE WAKE OF THE STORMS WILL BRIEF AS ONSHORE WINDS QUICKLY RECOVER. THIS STRENGTHENING FLOW FROM THE GULF WILL MAKE FOR WARM/HUMID CONDITIONS FOR SE TX DURING THE EARLY PART OF THE WEEK...THROUGH THURS. WHILE THE BEST POPS WILL LIKELY BE CON- FINED TO JUST AHEAD OF/WITH THE PASSAGE OF THE NEXT COLD FRONT ON THURS (AFTN OR NIGHT DEPENDING ON MODEL OF CHOICE)...STILL CANNOT RULE OUT ISO/WIDELY SCT WAA TYPE SHRA FOR THE COASTAL/NEAR COAST- AL LOCATIONS BY LATE TUES NIGHT/EARLY WEDS MORNING. FAVOURING THE SLIGHTLY SLOWER ECMWF IN THE EXTENDED FOR THE TIMING OF THIS NEXT COLD FRONT (AS IT HAS BEEN VERIFYING BEST OF LATE). WILL BE KEEP- ING A CLOSE EYE ON LATER RUNS TO SEE IF THEY CONTINUE WITH TRENDS OF LESS LIFT/WEAKER CAA WITH/BEHIND THIS FROPA. 41 MARINE... SURFACE HIGH PRESSURE EAST OF TEXAS WILL CONTINUE TO MOVE EAST AS A WEAK AREA OF LOW PRESSURE MOVES ALONG THE RED RIVER TONIGHT. THIS WILL KEEP WINDS SOUTHEASTERLY TONIGHT INTO TOMORROW WITH MODERATE SEAS. MODERATE SOUTHERLY WINDS SHOULD CONTINUE FOR THE EARLY PART OF THE COMING WEEK KEEPING SEAS AT LOW/MODERATE LEVELS. MAIN CONCERN WILL BE TUESDAY THROUGH THURSDAY WHEN LOW PRESSURE DEEPENS IN THE PLAINS. EXPECT WINDS TO INCREASE TO AROUND 20KTS ESPECIALLY AT NIGHT IN OFFSHORE AREAS. EXPECT SEAS TO BUILD TO 7-8FT AND ADVISORIES WILL LIKELY BE NEEDED DURING THIS TIME. A WEAK FRONT MAY PUSH OFF THE COAST LATE THURSDAY INTO FRIDAY. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 64 76 63 84 65 / 60 40 10 10 10 HOUSTON (IAH) 65 77 64 84 65 / 50 60 20 10 10 GALVESTON (GLS) 70 78 69 82 71 / 20 50 20 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
932 PM CDT MON OCT 28 2013 .UPDATE... 00Z DVN SOUNDING REFLECTING WARM ADVECTION BEGINNING AROUND 925 MB THROUGH 850 MB OVER DRY...COOL EAST-NORTHEAST FLOW BELOW 925 MB. NARROW SCATTERED TO BROKEN BAND OF WEAK RADAR RETURNS ON AREA RADARS FROM NE IOWA TO SW MN IN REGION OF 850 MB FRONTOGENESIS...WHICH LATEST 00Z NAM WEAKENS AS IT SHIFTS EASTWARD OVERNIGHT. STRONGEST RETURNS BETWEEN 30 DBZ AND 35 DBZ HAVE ONLY PRODUCED TRACE AMOUNTS/SEE KALO 0054Z OB/ WHICH ARE PROBABLY SPRINKLES WITH CEILING HEIGHTS OF 9K FT TO 11K FT. 00Z NAM AND HI- RES/RAPID UPDATE MODELS KEEP AREA DRY THROUGH 12Z TUE...THOUGH LAST TWO RUNS OF THE HRRR LOOK TO DEVELOP A SMALL BAND OF LAKE- EFFECT SHRA THAT WOULD AFFECT NRN OZAUKEE AND EASTERN SHEBOYGAN COUNTIES BETWEEN 09Z AND 12Z. WILL KEEP DRY FORECAST GOING WITH SLIGHTLY HIGHER...BUT STILL SUB-15 PCT... POPS OVER THE FAR NE AND IN THE NW WHERE SPRINKLES/FLURRIES ARE POSSIBLE. && .AVIATION/06Z TAFS/... WILL WATCH CIG HEIGHTS CAREFULLY UP TO ISSUANCE TIME...BUT LATEST NAM FORECAST SOUNDINGS INDICATE MVFR DECK SETTLES OVER REGION WITH 925-850 MB WARM AIR ADVECTION OVER COOL EASTERLY FLOW UNDERNEATH FOR THE OVERNIGHT HOURS INTO MID- MORNING TUESDAY. SOME SURFACE WARMING AS WINDS SHIFT SOUTHEAST WILL AID IN LIFTING THE CIGS TO VFR LEVELS AS LIFT WITH WARM AIR ADVECTION MOVES NORTHEAST. WILL AWAIT REST OF 00Z DATA...BUT CURRENT INDICATIONS ARE THAT RELATIVELY DRY SURFACE FLOW WILL HOLD OFF WIDESPREAD PCPN FROM MOVING INTO TAF SITES UNTIL AFTER 12Z WEDNESDAY. && .MARINE... WINDS HAVE BEEN GUSTING BELOW CRITERIA AT SHORELINE OB SITES SINCE THIS AFTERNOON...BUT GIVEN N-NE FETCH...WILL KEEP SMALL CRAFT ADVISORY GOING FOR THE NORTHERN ZONE UNTIL 06Z UNTIL WAVES SUBSIDE. SOUTHERN ZONES WILL BE SLOWER TO SUBSIDE UNTIL WINDS VEER TO THE EAST REDUCING THE FETCH SUFFICIENTLY FOR WAVES TO FALL BELOW CRITERIA. NO CHANGE TO END TIME IN THE SOUTH WITH THIS NSH ISSUANCE. && .PREV DISCUSSION... /ISSUED 240 PM CDT MON OCT 28 2013/ TONIGHT - CONFIDENCE...MEDIUM HIGH PRESSURE SPRAWLING FROM CANADA INTO THE NORTHERN PLAINS WILL SPREAD FURTHER SOUTHEAST INTO THE NORTHERN LAKES BY LATER TONIGHT. 850 MILLIBAR WARM AIR ADVECTION INCREASES INTO PORTIONS OF SC WI BETWEEN 6-12Z SO MID/HIGH CLOUD DEVELOPMENT LIKELY IN ASSOCIATION WITH THIS....ALREADY SEEING THE SIGNS ACRS SW MN AND NW IA. MEANWHILE AREA OF LOW CLOUDS EXTENDING FROM LOWER MICHIGAN WESTWARD INTO NE IA/SE MN NOT IN A HURRY TO GO ANYWHERE. LOW LEVEL RH PROGS/MOS AND SREF CIG PROBS MAINTAIN THIS CORRIDOR ACROSS SRN WI. SO NOT A BIG DROP OFF IN TEMPS DUE TO THE INSULATING BLANKET FOR MOST OF THE AREA. TUESDAY - CONFIDENCE...MEDIUM 850 WARM AIR ADVECTION CONTINUES WITH SOME ADIABATIC OMEGA AND LOWER CONDENSATION PRESSURE DEFICITS NOTED. LOW LEVEL DRY AIR WILL HAVE A SAY BUT BEST OVERLAP OF LIFT AND SOME MOISTURE SEEMS FOCUSED IN PORTIONS OF WESTERN AND NORTHERN CWA. EVEN THE USUALLY MORE ROBUST GFS HAS BACKED OFF ON QPF CWA WIDE...SO TRYING TO TRIM POPS BACK A BIT. WHILE 925 TEMPS ARE PROGGD TO PROGRESSIVELY MODERATE EXPECTING AN EXTENSIVE CLOUD COVER TO KEEP TEMPS FROM RISING AS HIGH AS THEY COULD GIVEN THOSE. NEVERTHELESS A MILDER AIRMASS WILL ADVECT NORTHWARD INTO THE AREA SO UPPER 40S/LOW 50S SEEMS REASONABLE. TUESDAY NIGHT INTO WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM. THE SURFACE WARM FRONT WILL LIKELY REMAIN SOUTH OF WISCONSIN UNTIL LATE WEDNESDAY MORNING OR EARLY AFTERNOON. HOWEVER...THE MAIN H8 WARM FRONT WILL PUSH NORTH OF THE CWA BY 12Z WEDNESDAY. WARM ADVECTION WILL BE RATHER PERSISTENT DURING THIS PERIOD...BUT AS MENTIONED IN PREVIOUS DISCUSSIONS...IT WILL BE BATTLING A DRY EAST TO SOUTHEAST FLOW. A FEW SHOWERS ARE POSSIBLE...ESPECIALLY OVER THE SOUTHERN AND WESTERN CWA...BUT SHOULD TURN TO MORE VIRGA ACROSS THE NORTH. HOWEVER...AS LOW PRESSURE BEGINS TO KICK OUT OF THE PLAINS AND HEADS TOWARD THE GREAT LAKES...RAIN WILL INCREASE IN COVERAGE AND INTENSITY FROM SOUTHWEST TO NORTHEAST WEDNESDAY AFTERNOON. WE COULD EVEN HEAR SOME THUNDER...BUT NOTHING SEVERE. THURSDAY AND THURSDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM TO HIGH. NO MAJOR CHANGES HERE. JUST UPPED POPS DUE TO INCREASING CONFIDENCE DUE TO MODEL CONSISTENCY FROM RUN TO RUN AND WITH EACH OTHER. MAIN SURGE OF MOISTURE AND FORCING COMES IN WEDNESDAY NIGHT. EVERYONE SHOULD SEE RAIN AND SOME OF IT COULD BE HEAVY AT TIMES AS PRECIPITABLE WATER VALUES ARE WELL ABOVE NORMAL FOR THIS TIME OF YEAR. THE SURFACE LOW WILL TRACK ACROSS NORTHWEST WISCONSIN DURING THE DAY ON THURSDAY WITH THE TRAILING COLD FRONT REACHING THE EASTERN CWA BY EARLY EVENING. THE ECMWF HAD BEEN SHOWING SOME SECONDARY DEVELOPMENT SOUTH ALONG THE FRONT THAT KEPT PRECIP GOING WELL INTO THURSDAY EVENING. IT DROPPED THAT SCENARIO ON LAST NIGHTS RUN. BUT IT IS BACK ON THE 12Z RUN. THE GEM IS CONTINUING TO SHOW IT AS WELL. THE GFS AND THE EXTRAPOLATED NAM DON/T REALLY HAVE THIS. OF COURSE THIS WILL HAVE A BIG IMPACT ON THOSE LITTLE TRICK-OR-TREATERS LATE THURSDAY AFTERNOON AND EVENING. IT/S A TIMING ISSUE AND WE/LL HAVE TO WAIT A BIT TO SEE HOW THIS WORKS OUT. WILL CONTINUE TO MENTION THUNDER THROUGH THURSDAY...MAINLY EAST...BUT NOTHING MAJOR. PROBABLY WIDESPREAD RAIN WITH EMBEDDED THUNDER. FRIDAY AND BEYOND...FORECAST CONFIDENCE IS MEDIUM. THE MAIN LOW WILL HAVE MOVED OFF TO THE EAST BY FRIDAY...BUT WE MAY SEE SOME LIGHT RAIN OR SPRINKLES IN SOME WRAP AROUND MOISTURE WITH A SECONDARY TROF MOVING THROUGH. THEN DRY WEATHER MOVES IN FOR THE WEEKEND. ANOTHER SYSTEM IS EXPECTED TO ORGANIZE AND BRING ANOTHER CHANCE FOR RAIN ON MONDAY. AVIATION/00Z TAFS/...VISIBLE SATELLITE LOOP/LOW LEVEL RH PROGS AND MOS ALL SUPPORT KEEPING THE CLOUD COVER IN PLACE THROUGH AT LEAST TUESDAY MORNING. CEILINGS MOSTLY MVFR THOUGH A FEW VFR POCKETS HERE AND THERE. SQUEEZE PLAY IS ON BETWEEN STRONG CANADIAN HIGH PRESSURE AND DEVELOPING LOW PRESSURE NEAR THE OKLAHOMA PANHANDLE. SURFACE HIGH BUILDS SOUTHEAST INTO THE EASTERN LAKES HEADING INTO TUESDAY SO FLOW WILL TURN FROM NORTHEAST TO MORE OF A SOUTHEAST FLOW...BUT THIS WILL MAINTAIN A DRY FLOW AND KEEP PRECIP MAINLY ACROSS CNTRL WI. THE NAM APPEARS TO BE DOING THE BEST JOB ON HANDLING THE DEEPER DRY AIR FEED INTO SRN WI. MARINE...A SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 1 AM TUESDAY FROM PORT WASHINGTON TO SHEBOYGAN. A SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 1 PM TUESDAY FROM NORTH POINT LIGHTHOUSE TO WINTHROP HARBOR ILLINOIS. THE WINDS AND WAVES WILL GRADUALLY LESSEN TNT BUT REMAIN SUFFICIENTLY HIGH TO POSE A DANGER TO SMALL CRAFT TNT INTO TUE. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 1 PM CDT TUESDAY FOR LMZ645-646. SMALL CRAFT ADVISORY UNTIL 1 AM CDT TUESDAY FOR LMZ643-644. && $$ UPDATE...REM TONIGHT/TUESDAY AND AVIATION/MARINE...COLLAR TUESDAY NIGHT THROUGH MONDAY...DAVIS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
944 PM MDT MON OCT 28 2013 .UPDATE... ISSUED AT 944 PM MDT MON OCT 28 2013 VISIBILITIES IN FOG HAVE IMPROVED OVER MUCH OF SOUTHEAST WYOMING AS OF 0330Z. THE FAIRLY TIGHT SURFACE PRESSURE GRADIENT AS WELL AS A CLOUD BAND MOVING OVER THE AREA HAVE HELPED TO IMPROVE THE VISIBILITIES. HAVE WENT AHEAD AND LIFTED THE DENSE FOG ADVISORY FOR ALL BUT EHS SOUTHERN LARAMIE RANGE. TOUGH CALL... BUT WITH SURFACE WINDS TRYING TO TURN MORE SOUTH AS THE NIGHT GOES ON BELIEVE VISIBILIITES SHOULD BE GREATER THAN EARLIER...BUT STILL MAY DROP TO A MILE OR LESS AT TIMES. FREEZING DRIZZLE STILL OCCURRING...BUT INDICATIONS ARE THAT INTENSITY HAS LET UP SOME.ALSO IN SOME PLACES...LIKE KCYS...THE FREEZING DRIZZLE HAS MIXED WITH LIGHT SNOW. TEMPERATURES IN THE 700 TO 600 MB LAYER SHOULD CONTINUE TO SLOWLY COOL THE REST OF THE NIGHT AND ENABLE MORE PLACES TO MIX WITH OR CHANGE TO LIGHT SNOW. ROADS ARE STILL SLICK IN MANY PLACES EAST OF THE LARAMIE RANGE DUE TO THE RECENT FREEZING DRIZZLE AND SO WILL KEEP THE ADVISORY GOING TIL 18Z. RECENT UPDATE AVAILABLE WHICH INCLUDES THE SMALLER AREA FOR THE DENSE FOG ADVISORY. UPDATE ISSUED AT 633 PM MDT MON OCT 28 2013 FOGGY CONDITIONS AND LIGHT PRECIPITATION WILL PERSIST OVER AND EAST OF THE LARAMIE RANGE TONIGHT AND TUESDAY. AT 00Z...THE PRECIPITATION OVER MUCH OF THAT AREA WAS FREEZING DRIZZLE OR EVEN FREEZING RAIN...AT KBFF AND KTOR. MEANWHILE...OVER NORTHERN SIOUX AND DAWES COUNTIES...THE PRECIPITATION AT THAT TIME WAS MAINLY IN THE FORM OF LIGHT SNOW. FROM AREA PROFILES AND RECEIVED 00Z RAOBS...COOLING HAS TAKEN PLACE BETWEEN 700 AND 500 MB DURING THE DAY. THAT SLOW TREND SHOULD CONTINUE THE REST OF TONIGHT... EVEN THOUGH SOME WARM AIR ADVECTION AT THAT LEVEL IS TRYING TO SPREAD NORTH IN ADVANCE OF THE UPSTREAM STORM SYSTEM. THE FREEZING DRIZZLE SHOULD MIX WITH AND PERHAPS CHANGE TO MORE LIGHT SNOW TONIGHT AND TUESDAY MORNING. THE UPSLOPE MOIST BOUNDARY LAYER WINDS WILL TURN TO MORE SOUTHEAST TONIGHT...AND SHOULD KEEP THE LOW CLOUDS AND FOG TONIGHT AND LIKELY THROUGH TUESDAY OVER AND EAST OF THE LARAMIE RANGE. AREAS OF LIGHT SNOW SHOULD ALSO SPREAD OVER THE WEST PART OF THE CWA TONIGHT AS SEVERAL BAROCLINIC BANDS ARE SPREADING INTO THAT AREA FROM AHEAD OF THE STORM. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 330 PM MDT MON OCT 28 2013 SEVERAL FORECAST CHALLENGES WITH THIS FORECAST PACKAGE...INCLUDING FREEZING DRIZZLE AND DENSE FOG THIS AFTERNOON THROUGH TUESDAY MORNING AS WELL AS A POSSIBLE HEAVY SNOW EVENT TUESDAY NIGHT INTO WEDNESDAY MORNING. CURRENTLY...LATEST WATER VAPOR IMAGERY SHOWING A CLOSED LOW ROTATING OVER CENTRAL NEVADA THIS AFTERNOON. IR IMAGERY SHOWING SOME ENERGY BEING SPUN OFF THE LOW WHICH IS EJECTING INTO SOUTHWESTERN WYOMING AND WESTERN COLORADO ATTM. LOOKS FAIRLY UNSTABLE OUT THAT WAY AND WE HAVE SEEN SOME LIGHTNING STRIKES RECENTLY OVER NEVADA AND EARLIER IN UTAH FROM THAT ENERGY MOVING INTO SOUTHWEST WYOMING. CLOSER TO HOME...THE SURFACE BOUNDARY CURRENTLY EXTENDS FROM NEAR DENVER...OUT ACROSS NORTHEASTERN UTAH...NORTH THROUGH IDAHO AND UP INTO BRITISH COLUMBIA. VERY ESTABLISHED NORTHEASTERLY WIND FLOW ACROSS THE PANHANDLE...ALL THE WAY TO RAWLINS THIS AFTERNOON. EXPANSIVE AREA OF STRATUS FROM SOUTH OF DENVER NORTH INTO SOUTHERN MONTANA. WE HAVE BEEN EXPERIENCING DENSE FOG AND FREEZING DRIZZLE MOST OF THE DAY. TEMPERATURES HAVE STRUGGLED WITH THIS NORTHEAST FLOW AND DENSE STRATUS...STILL ONLY 26 HERE AT CHEYENNE...28 AT DOUGLAS AND LOW 30S OUT IN THE PANHANDLE. WENT AHEAD AND ISSUED A DENSE FOG ADVISORY FOR AREAS ALONG THE EAST SLOPES OF THE LARAMIE RANGE FOR THE REST OF THE AFTERNOON AND OVERNIGHT. LATEST NAM SOUNDING CONTINUE TO SHOW DEEP LOW LEVEL MOISTURE PERSISTING THROUGH THE OVERNIGHT HOURS. GFS AND NAM SOUNDINGS SHOWING THE WINDS SHIFTING SOUTHEASTERLY THROUGH THE AFTERNOON...BUT SO FAR...NORTHEAST WINDS REMAIN IN PLACE. DO NOT THINK THAT WILL CHANGE ANY AS THE RUC SHOWS NORTHEASTERLY WINDS PERSISTING. WELL ESTABLISHED FREEZING DRIZZLE PROFILES PERSIST EAST OF THE LARAMIE RANGE AS WELL. SO WILL KEEP THE FREEZING DRIZZLE ADVISORY GOING AS SCHEDULED. COULD GET PRETTY NASTY EAST OF THE LARAMIE RANGE AFTER SUNSET AS TEMPERATURES CONTINUE TO COOL INTO THE LOW TO MID 20S BY EARLY TUESDAY MORNING. WOULD NOT BE SURPRISED TO SEE QUITE A BIT OF BLACK ICE ACROSS OUR CWA EAST OF THE LARAMIE RANGE. BE CAREFUL OUT THERE IF YOU ARE TRAVELING TONIGHT AND TUESDAY MORNING. BY MID TUESDAY MORNING...UPPER LOW FORECAST TO TRACK INTO WESTERN WYOMING. THIS SHOULD SHIFT LOW LEVEL WINDS MORE SOUTHEASTERLY. STRATUS LIKELY TO CONTINUE IN THIS SOUTHEASTERLY FLOW...BUT THE DENSE FOG AND FREEZING DRIZZLE SHOULD EASE AS TEMPERATURE RISE. STILL...A COOL DAY IN STORE FOR TUESDAY...WITH HIGHS IN THE LOW 40S EAST OF THE LARAMIE RANGE TO LOW 30S OVER THE NORTHERN PANHANDLE. DID SHAVE A FEW DEGREES OFF GUIDANCE TO ACCOUNT FOR THE STRATUS. FINALLY TUESDAY NIGHT INTO WEDNESDAY...MODELS IN GOOD AGREEMENT WITH SOME MID LEVEL FRONTOGENESIS DEVELOPING AHEAD OF THE EJECTING LOW. GFS PAINTING A .6 INCH QPF BULLSEYE OVER THE SOUTHERN PANHANDLE BACK TO CHEYENNE. LATEST ECMWF GUIDANCE SHOWING AROUND 0.4 INCHES OVER LARAMIE COUNTY EXTENDING UP INTO THE CENTRAL PANHANDLE...WHILE THE NAM SHOWS SOMETHING SIMILAR TO THE ECMWF...ONLY A LITTLE LIGHTER ON PRECIP AMOUNTS. USING NAM TEMPERATURE PROFILES...THIS PRECIP COULD FALL AS ALL SNOW WHILE THE GFS SHOWING A MUCH WARMER SCENARIO. LATER SHIFTS WILL NEED TO TRY TO NAIL DOWN A GOOD LOCATION FOR THE BANDING PRECIP DEVELOPMENT. WOULD THINK WE WOULD NEED AT LEAST A WINTER WEATHER ADVISORY OUT FOR THE AREA ONCE THE AREA HAS BEEN IDENTIFIED...MAYBE EVEN A SHORT FUSED WARNING IF THE GFS QPF FORECAST COMES TRUE. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 330 PM MDT MON OCT 28 2013 LONG RANGE MODELS IN GOOD AGREEMENT THROUGH THE WEEKEND...SHOWING THE UPPER LEVEL LOW BECOMING AN OPEN WAVE TROUGH AND EXITING THE REGION TO THE EAST WEDNESDAY NIGHT. EXPECT PRECIP TO GRADUALLY COME TO AN END BEHIND THE TROUGH AXIS FOR MOST AREAS OUTSIDE OF THE MOUNTAINS LATE WEDNESDAY NIGHT. MODELS SHOW DECENT UPSLOPE FLOW AND MOUNTAIN SNOW SHOWERS THROUGH FRIDAY AS SEVERAL WEAK SHORTWAVES PUSH ACROSS THE AREA EMBEDDED IN BROAD NORTHWEST FLOW ALOFT. THE PRIMARY FORECAST CONCERN LATER THIS WEEK IS THE POTENTIAL FOR STRONG GUSTY WINDS ACROSS PORTIONS OF SOUTHEAST WYOMING. LOOKS LIKE A CLASSIC GAP WIND CASE WITH 700MB WINDS APPROACHING 50 KNOTS ALONG THE I80 CORRIDOR ALONG WITH AN INCREASING PRESSURE GRADIENT ALONG THE FRONT RANGE. LOOKS LIKE HIGHER ELEVATIONS AND THE WIND PRONE AREAS MAY RECEIVE GUSTS UP TO 60 MPH...ALTHOUGH IT WILL BE PRETTY WINDY ACROSS THE LOWER ELEVATIONS OF SOUTHEAST WYOMING INTO THURSDAY AS WELL...WITH WESTERLY WINDS SUSTAINED BETWEEN 20 TO 35 MPH AND GUSTING UP TO 50 MPH. WITH NORTHWEST FLOW ALOFT...DO NOT EXPECT TEMPERATURES TO INCREASE TOO MUCH THIS WEEK. HIGHS WILL GENERALLY REMAIN IN THE 40S TO LOW 50S ACROSS THE FORECAST AREA. ALL MODELS INDICATE THE UPPER LEVEL FLOW BACKING INTO THE SOUTHWEST BY NEXT WEEKEND AS AN UPPER LEVEL RIDGE AXIS FLATTENS AND THEN MOVES ACROSS THE AREA. THIS WILL ALLOW TEMPERATURES TO MODERATE INTO THE 50S TO LOW 60S ACROSS THE AREA. MODELS INDICATE ANOTHER PACIFIC STORM SYSTEM AND ASSOCIATED COLD FRONT MOVING ACROSS THE PAC NORTHWEST THIS WEEKEND. THIS SYSTEM WILL EVENTUALLY PUSH EASTWARD INTO THE NORTHERN AND CENTRAL ROCKYS BY SUNDAY AND MONDAY. THIS STORM SYSTEM HAS THE POTENTIAL TO BRING MUCH COLDER AIR TO SOUTHEAST WYOMING AND WESTERN NEBRASKA FOR EARLY NEXT WEEK...WITH THE ADDITION OF ACCUMULATING SNOWFALL. DUE TO TIMING DIFFERENCES...ONLY INCREASED POP TO NEAR 20 PERCENT ACROSS SOUTHEAST WYOMING ON MONDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY EVENING) ISSUED AT 944 PM MDT MON OCT 28 2013 IFR CEILINGS AND VISIBILITIES IN FREEZING DRIZZLE...SNOW AND FOG WILL CONTINUE OVER MUCH OF THE CWA THE REST OF TONIGHT AND AT LEAST TUESDAY MORNING. CEILINGS AND VISIBILITIES WILL GRADUALLY IMPROVE FROM WEST TO EAST LATE TONIGHT AND TUESDAY MORNING AS THE SURFACE WINDS TURN MORE WESTERLY. THE MOUNTAINS WILL BE OBSCURED THROUGH TUESDAY AND RIME ICING WILL BE A CONCERN OVER THE EAST PART OF THE CWA DURING THAT TIME. SNOW WILL BECOME MORE WIDESPREAD OVER THE CWA TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. EASTERLY SURFACE WINDS WILL GUST AS HIGH AS 35 KNOTS THROUGH 12Z OVER ALBANY AND CARBON COUNTIES. && .FIRE WEATHER... ISSUED AT 330 PM MDT MON OCT 28 2013 LOW PRESSURE OVER SOUTHERN NEVADA IS MOVING INTO SOUTHWESTERN COLORADO LATER THIS AFTERNOON. THIS SYSTEM WILL BRING UNSETTLED WEATHER TO THE AREA AS WELL AS COLDER TEMPERATURES AND HIGH HUMIDITIES. THEREFORE...FIRE WEATHER CONCERNS WILL BE MINIMIZED THROUGH WEDNESDAY. AS THE LOW EXITS EAST WEDNESDAY NIGHT...STRONG SOUTHWEST WINDS ARE EXPECTED TO DEVELOP ACROSS SOUTHEAST WYOMING WITH GUSTS TO 45 TO 50 MPH POSSIBLE. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...FREEZING RAIN ADVISORY UNTIL NOON MDT TUESDAY FOR WYZ101-102- 106>108-117>119. DENSE FOG ADVISORY UNTIL 6 AM MDT TUESDAY FOR WYZ116. NE...FREEZING RAIN ADVISORY UNTIL NOON MDT TUESDAY FOR NEZ002-003-095- 096. && $$ UPDATE...WEILAND SHORT TERM...CLAYCOMB LONG TERM...TJT AVIATION...WEILAND FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
633 PM MDT MON OCT 28 2013 .UPDATE... ISSUED AT 633 PM MDT MON OCT 28 2013 FOGGY CONDITIONS AND LIGHT PRECIPITATION WILL PERSIST OVER AND EAST OF THE LARAMIE RANGE TONIGHT AND TUESDAY. AT 00Z...THE PRECIPITATION OVER MUCH OF THAT AREA WAS FREEZING DRIZZLE OR EVEN FREEZING RAIN...AT KBFF AND KTOR. MEANWHILE...OVER NORTHERN SIOUX AND DAWES COUNTIES...THE PRECIPITATION AT THAT TIME WAS MAINLY IN THE FORM OF LIGHT SNOW. FROM AREA PROFILES AND RECEIVED 00Z RAOBS...COOLING HAS TAKEN PLACE BETWEEN 700 AND 500 MB DURING THE DAY. THAT SLOW TREND SHOULD CONTINUE THE REST OF TONIGHT... EVEN THOUGH SOME WARM AIR ADVECTION AT THAT LEVEL IS TRYING TO SPREAD NORTH IN ADVANCE OF THE UPSTREAM STORM SYSTEM. THE FREEZING DRIZZLE SHOULD MIX WITH AND PERHAPS CHANGE TO MORE LIGHT SNOW TONIGHT AND TUESDAY MORNING. THE UPSLOPE MOIST BOUNDARY LAYER WINDS WILL TURN TO MORE SOUTHEAST TONIGHT...AND SHOULD KEEP THE LOW CLOUDS AND FOG TONIGHT AND LIKELY THROUGH TUESDAY OVER AND EAST OF THE LARAMIE RANGE. AREAS OF LIGHT SNOW SHOULD ALSO SPREAD OVER THE WEST PART OF THE CWA TONIGHT AS SEVERAL BAROCLINIC BANDS ARE SPREADING INTO THAT AREA FROM AHEAD OF THE STORM. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 330 PM MDT MON OCT 28 2013 SEVERAL FORECAST CHALLENGES WITH THIS FORECAST PACKAGE...INCLUDING FREEZING DRIZZLE AND DENSE FOG THIS AFTERNOON THROUGH TUESDAY MORNING AS WELL AS A POSSIBLE HEAVY SNOW EVENT TUESDAY NIGHT INTO WEDNESDAY MORNING. CURRENTLY...LATEST WATER VAPOR IMAGERY SHOWING A CLOSED LOW ROTATING OVER CENTRAL NEVADA THIS AFTERNOON. IR IMAGERY SHOWING SOME ENERGY BEING SPUN OFF THE LOW WHICH IS EJECTING INTO SOUTHWESTERN WYOMING AND WESTERN COLORADO ATTM. LOOKS FAIRLY UNSTABLE OUT THAT WAY AND WE HAVE SEEN SOME LIGHTNING STRIKES RECENTLY OVER NEVADA AND EARLIER IN UTAH FROM THAT ENERGY MOVING INTO SOUTHWEST WYOMING. CLOSER TO HOME...THE SURFACE BOUNDARY CURRENTLY EXTENDS FROM NEAR DENVER...OUT ACROSS NORTHEASTERN UTAH...NORTH THROUGH IDAHO AND UP INTO BRITISH COLUMBIA. VERY ESTABLISHED NORTHEASTERLY WIND FLOW ACROSS THE PANHANDLE...ALL THE WAY TO RAWLINS THIS AFTERNOON. EXPANSIVE AREA OF STRATUS FROM SOUTH OF DENVER NORTH INTO SOUTHERN MONTANA. WE HAVE BEEN EXPERIENCING DENSE FOG AND FREEZING DRIZZLE MOST OF THE DAY. TEMPERATURES HAVE STRUGGLED WITH THIS NORTHEAST FLOW AND DENSE STRATUS...STILL ONLY 26 HERE AT CHEYENNE...28 AT DOUGLAS AND LOW 30S OUT IN THE PANHANDLE. WENT AHEAD AND ISSUED A DENSE FOG ADVISORY FOR AREAS ALONG THE EAST SLOPES OF THE LARAMIE RANGE FOR THE REST OF THE AFTERNOON AND OVERNIGHT. LATEST NAM SOUNDING CONTINUE TO SHOW DEEP LOW LEVEL MOISTURE PERSISTING THROUGH THE OVERNIGHT HOURS. GFS AND NAM SOUNDINGS SHOWING THE WINDS SHIFTING SOUTHEASTERLY THROUGH THE AFTERNOON...BUT SO FAR...NORTHEAST WINDS REMAIN IN PLACE. DO NOT THINK THAT WILL CHANGE ANY AS THE RUC SHOWS NORTHEASTERLY WINDS PERSISTING. WELL ESTABLISHED FREEZING DRIZZLE PROFILES PERSIST EAST OF THE LARAMIE RANGE AS WELL. SO WILL KEEP THE FREEZING DRIZZLE ADVISORY GOING AS SCHEDULED. COULD GET PRETTY NASTY EAST OF THE LARAMIE RANGE AFTER SUNSET AS TEMPERATURES CONTINUE TO COOL INTO THE LOW TO MID 20S BY EARLY TUESDAY MORNING. WOULD NOT BE SURPRISED TO SEE QUITE A BIT OF BLACK ICE ACROSS OUR CWA EAST OF THE LARAMIE RANGE. BE CAREFUL OUT THERE IF YOU ARE TRAVELING TONIGHT AND TUESDAY MORNING. BY MID TUESDAY MORNING...UPPER LOW FORECAST TO TRACK INTO WESTERN WYOMING. THIS SHOULD SHIFT LOW LEVEL WINDS MORE SOUTHEASTERLY. STRATUS LIKELY TO CONTINUE IN THIS SOUTHEASTERLY FLOW...BUT THE DENSE FOG AND FREEZING DRIZZLE SHOULD EASE AS TEMPERATURE RISE. STILL...A COOL DAY IN STORE FOR TUESDAY...WITH HIGHS IN THE LOW 40S EAST OF THE LARAMIE RANGE TO LOW 30S OVER THE NORTHERN PANHANDLE. DID SHAVE A FEW DEGREES OFF GUIDANCE TO ACCOUNT FOR THE STRATUS. FINALLY TUESDAY NIGHT INTO WEDNESDAY...MODELS IN GOOD AGREEMENT WITH SOME MID LEVEL FRONTOGENESIS DEVELOPING AHEAD OF THE EJECTING LOW. GFS PAINTING A .6 INCH QPF BULLSEYE OVER THE SOUTHERN PANHANDLE BACK TO CHEYENNE. LATEST ECMWF GUIDANCE SHOWING AROUND 0.4 INCHES OVER LARAMIE COUNTY EXTENDING UP INTO THE CENTRAL PANHANDLE...WHILE THE NAM SHOWS SOMETHING SIMILAR TO THE ECMWF...ONLY A LITTLE LIGHTER ON PRECIP AMOUNTS. USING NAM TEMPERATURE PROFILES...THIS PRECIP COULD FALL AS ALL SNOW WHILE THE GFS SHOWING A MUCH WARMER SCENARIO. LATER SHIFTS WILL NEED TO TRY TO NAIL DOWN A GOOD LOCATION FOR THE BANDING PRECIP DEVELOPMENT. WOULD THINK WE WOULD NEED AT LEAST A WINTER WEATHER ADVISORY OUT FOR THE AREA ONCE THE AREA HAS BEEN IDENTIFIED...MAYBE EVEN A SHORT FUSED WARNING IF THE GFS QPF FORECAST COMES TRUE. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 330 PM MDT MON OCT 28 2013 LONG RANGE MODELS IN GOOD AGREEMENT THROUGH THE WEEKEND...SHOWING THE UPPER LEVEL LOW BECOMING AN OPEN WAVE TROUGH AND EXITING THE REGION TO THE EAST WEDNESDAY NIGHT. EXPECT PRECIP TO GRADUALLY COME TO AN END BEHIND THE TROUGH AXIS FOR MOST AREAS OUTSIDE OF THE MOUNTAINS LATE WEDNESDAY NIGHT. MODELS SHOW DECENT UPSLOPE FLOW AND MOUNTAIN SNOW SHOWERS THROUGH FRIDAY AS SEVERAL WEAK SHORTWAVES PUSH ACROSS THE AREA EMBEDDED IN BROAD NORTHWEST FLOW ALOFT. THE PRIMARY FORECAST CONCERN LATER THIS WEEK IS THE POTENTIAL FOR STRONG GUSTY WINDS ACROSS PORTIONS OF SOUTHEAST WYOMING. LOOKS LIKE A CLASSIC GAP WIND CASE WITH 700MB WINDS APPROACHING 50 KNOTS ALONG THE I80 CORRIDOR ALONG WITH AN INCREASING PRESSURE GRADIENT ALONG THE FRONT RANGE. LOOKS LIKE HIGHER ELEVATIONS AND THE WIND PRONE AREAS MAY RECEIVE GUSTS UP TO 60 MPH...ALTHOUGH IT WILL BE PRETTY WINDY ACROSS THE LOWER ELEVATIONS OF SOUTHEAST WYOMING INTO THURSDAY AS WELL...WITH WESTERLY WINDS SUSTAINED BETWEEN 20 TO 35 MPH AND GUSTING UP TO 50 MPH. WITH NORTHWEST FLOW ALOFT...DO NOT EXPECT TEMPERATURES TO INCREASE TOO MUCH THIS WEEK. HIGHS WILL GENERALLY REMAIN IN THE 40S TO LOW 50S ACROSS THE FORECAST AREA. ALL MODELS INDICATE THE UPPER LEVEL FLOW BACKING INTO THE SOUTHWEST BY NEXT WEEKEND AS AN UPPER LEVEL RIDGE AXIS FLATTENS AND THEN MOVES ACROSS THE AREA. THIS WILL ALLOW TEMPERATURES TO MODERATE INTO THE 50S TO LOW 60S ACROSS THE AREA. MODELS INDICATE ANOTHER PACIFIC STORM SYSTEM AND ASSOCIATED COLD FRONT MOVING ACROSS THE PAC NORTHWEST THIS WEEKEND. THIS SYSTEM WILL EVENTUALLY PUSH EASTWARD INTO THE NORTHERN AND CENTRAL ROCKYS BY SUNDAY AND MONDAY. THIS STORM SYSTEM HAS THE POTENTIAL TO BRING MUCH COLDER AIR TO SOUTHEAST WYOMING AND WESTERN NEBRASKA FOR EARLY NEXT WEEK...WITH THE ADDITION OF ACCUMULATING SNOWFALL. DUE TO TIMING DIFFERENCES...ONLY INCREASED POP TO NEAR 20 PERCENT ACROSS SOUTHEAST WYOMING ON MONDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY AFTERNOON) ISSUED AT 633 PM MDT MON OCT 28 2013 IFR CEILINGS AND VISIBILITIES IN FREEZING DRIZZLE...SNOW AND FOG WILL CONTINUE OVER AND EAST OF THE LARAMIE RANGE TONIGHT AND TUESDAY. CEILINGS AND VISIBILITIES WILL GRADUALLY LIFT SOME DURING THE DAY TUESDAY. THE MOUNTAINS WILL BE OBSCURED THROUGH TUESDAY AND RIME ICING WILL BE A CONCERN OVER THE EAST PART OF THE CWA DURING THAT TIME. OVER SOUTH CENTRAL WYOMING...THERE WILL BE PERIODS OF MVFR CEILINGS AND VISIBILITIES IN SNOW. SNOW WILL BECOME MORE WIDESPREAD OVER THE CWA TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. EASTERLY SURFACE WINDS WILL GUST AS HIGH AS 35 KNOTS THROUGH 06Z OVER PARTS OF ALBANY AND CARBON COUNTIES. && .FIRE WEATHER... ISSUED AT 330 PM MDT MON OCT 28 2013 LOW PRESSURE OVER SOUTHERN NEVADA IS MOVING INTO SOUTHWESTERN COLORADO LATER THIS AFTERNOON. THIS SYSTEM WILL BRING UNSETTLED WEATHER TO THE AREA AS WELL AS COLDER TEMPERATURES AND HIGH HUMIDITIES. THEREFORE...FIRE WEATHER CONCERNS WILL BE MINIMIZED THROUGH WEDNESDAY. AS THE LOW EXITS EAST WEDNESDAY NIGHT...STRONG SOUTHWEST WINDS ARE EXPECTED TO DEVELOP ACROSS SOUTHEAST WYOMING WITH GUSTS TO 45 TO 50 MPH POSSIBLE. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...FREEZING RAIN ADVISORY UNTIL NOON MDT TUESDAY FOR WYZ101-102- 106>108-117>119. DENSE FOG ADVISORY UNTIL 6 AM MDT TUESDAY FOR WYZ101-106-107- 117>119. NE...FREEZING RAIN ADVISORY UNTIL NOON MDT TUESDAY FOR NEZ002-003-095- 096. && $$ UPDATE...WEILAND SHORT TERM...CLAYCOMB LONG TERM...TJT AVIATION...WEILAND FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1111 PM MDT MON OCT 28 2013 .UPDATE... ISSUED AT 637 PM MDT MON OCT 28 2013 UPDATED TO FORECAST TO REFLECT THE LATEST SATELLITE TRENDS AND HIGH-RES MODEL GUIDANCE...A BLEND OF THE HRRR AND WRF. DELAYED THE PRECIPITATION FOR MOST OF THE NIGHT ALONG THE CONTINENTAL DIVIDE WITH A RAMP UP OF POPS BY TUESDAY MORNING. BEFORE THAT...JUST ISOLATED SNOW SHOWERS ARE EXPECTED WITH AN INCH OR TWO POSSIBLE ACROSS THE PEAKS. REMOVED THE THUNDERSTORM CHANCES ALONG THE KANSAS BORDER FOR THIS EVENING...LATEST RADAR TRENDS HAVE THUNDERSTORMS WELL INTO KANSAS...WITH VERY LIMITED MOISTURE AND FORCING OVER OUR EASTERN COUNTIES. LOW STRATUS OVER NORTHEAST COLORADO WILL SHIFT SOUTH ACROSS THE PLAINS THROUGH THE OVERNIGHT. THIS AREA OF MOISTURE IS VERY SHALLOW WITH PATCHY FOG...AND OVERCAST CONDITIONS ACROSS MUCH OF THE PLAINS. THERE MAY ALSO BE SOME PATCHY FREEZING DRIZZLE OVER THE PALMER DIVIDE...AND CAUTION IS ADVISED TOWARD MORNING FOR PATCHY BLACK ICE. ELSEWHERE...MOISTURE LOOKS TO BE TOO SHALLOW FOR DRIZZLE. DELAYED WARMING ALONG THE ARKANSAS RIVER VALLEY FOR TOMORROW MORNING. PUEBLO MAY BE IN THE 30S TO 40S FOR MUCH OF THE DAY UNTIL MIXING TAKES OVER BY MID AFTERNOON. MOZLEY && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 337 PM MDT MON OCT 28 2013 COOL FRONT HAS SLIPPED DOWN TO THE CO/NM BORDER WITH THE BOUNDARY JUST N OF THE STATE LINE. NE COLO WAS SOCKED IN WITH LOW CLOUDS AND THESE CLOUDS WERE JUST MAKING IT INTO EXTREME N AND NE EL PASO COUNTY. A COUPLE OF WELL DEFINED WIND SHIFT LINES WERE NOTED OVER S EL PASO AND N PUEBLO COUNTIES. THESE BOUNDARIES WERE ASSOCIATED WITH WIND SHIFT LINES (NE WINDS VS SE WINDS). ELSEWHERE...A STRONG UPPER LOW WAS NOTED OVER NEVADA AND WAS MOVING SLOWLY EAST. QUITE A BIT OF DRY AIR IN THE UPPER LEVELS WAS NOTED IN ADVANCE OF THIS SYSTEM PER WATER VAP IMGY. REST OF TODAY INTO TONIGHT... FIRST CONCERN WILL BE THUNDER. SIMULATIONS CONTINUE TO SHOW TSRA BREAKING OUT ALONG THE CO/KS BORDER EARLY THIS EVENING. FOR THIS REASON KEPT VERY SLIGHT POPS ALONG THE BORDER FOR THIS EVENING. I AM HIGHLY CONFIDENT CONVECTION WILL OCCUR...BUT DO NOT KNOW WHICH SIDE OF THE BORDER IT WILL INITIATE ON. SPC HAS THE AREA OUTLOOKED WITH A 5% CHANCE OF SVR (HAIL). 2ND CONCERN IS LOW CLOUDS/FOG TONIGHT. VERY CONFIDENT LOW CLOUDS WILL BE OVER MOST OF THE PLAINS TONIGHT...HOWEVER CONFIDENCE IS NOT TOO HIGH ON HOW FAR WEST THESE CLOUDS WILL MAKE IT BACK TOWARDS THE MTNS. LATEST HRRR HAS BECOME A BIT MORE AGGRESSIVE MOVING THE CLOUDS ALL THE WAY BACK TO THE MTNS. CONCEPTUALLY...THIS LOOKS REALISTIC AND WILL LIKELY ADD MORE CLOUDS INTO THE NDFD. OVER THE CONTDVD...MSTR WILL SLOWLY INCREASE TONIGHT...BUT EXPECT MAINLY SNOW SHOWERS...ESPECIALLY THE SAN JUANS...WITH INSIGNIFICANT ACCUMS. SOME FREEZING FOG WILL BE POSSIBLE TONIGHT OVER EL PASO COUNTY. TUESDAY... UPPER LOW WILL MOVE CLOSER TO THE REGION AND FLOW ALOFT WILL INTENSIFY. SFC BOUNDARY ALONG THE CO/NM BORDER WILL LIKELY PUSH NORTH TOMORROW...BUT HOW FAR N IS THE QUESTION. ATTM...I HAVE THE BOUNDARY RUNNING ROUGHLY FROM KCOS DOWN TO KSPD BY MID AFTERNOON TOMORROW. LIKEWISE...GUSTY SW WINDS WILL BE LIKELY OVER THE S TIER FOR THE FCST AREA...AND WE WILL LIKELY MIX OUT ACROSS EL PASO SO COULD SEE SOME GUSTY WARM WINDS THIS LOCATION BY MID DAY. IT IS POSSIBLE KPUB AREA WILL NOT MIX OUT TOMORROW WHILE EL PASO COUNTY DOES MIX OUT. HIGH TEMPS TOMORROW AT KCOS MAY BE WARMER THAN KPUB. IF THIS VERIFIES...THEN CURRENT FCST WILL NEED TO BE ADJUSTED BY LATER SHIFTS. SNOWS WILL GRADUALLY RAMP UP OVER THE MTNS ALONG THE CONTDVD...ESPECIALLY LATER TOMORROW AFTERNOON. COULD SEE A COUPLE OF INCHES OF SNOW...ESPECIALLY ABOVE 10KFT BY LATE TOMORROW AFTERNOON. IT WILL LIKELY BE WINDY ANY WHERE SOUTH OF THE FRONT...WITH GUSTS TO 25 TO 35 MPH POSSIBLE...AND 40 TO 45 MPH OVER THE HIGHER TRRN. /HODANISH. .LONG TERM...(TUESDAY NIGHT THROUGH NEXT MONDAY) ISSUED AT 337 PM MDT MON OCT 28 2013 UNSETTLED METEOROLOGICAL CONDITIONS ARE ANTICIPATED OVER PORTIONS OF THE FORECAST DISTRICT FROM TUESDAY NIGHT INTO THURSDAY...ESPECIALLY OVER THE CENTRAL MOUNTAINS...AS A UPPER SYSTEM IMPACTS THE CWFA DURING THIS TIME-FRAME. A RETURN TO DRIER AND WARMER CONDITIONS IS THEN PROJECTED TO RETURN TO THE FORECAST DISTRICT BY THIS WEEKEND. RECENT LONGER RANGE COMPUTER SIMULATIONS AND FORECAST MODEL SOUNDINGS SUGGEST THAT DOUBLE-BARRELED CLOSED UPPER LOW INITIALLY LOCATED OVER NORTHWESTERN WYOMING AND SOUTHERN NEVADA RESPECTIVELY AT 06Z WEDNESDAY WILL ROTATE INTO AN EASTERN WYOMING/SOUTHWESTERN COLORADO LOCATION BY 00Z THURSDAY BEFORE SHIFTING EAST OF THE FORECAST DISTRICT BY 18Z THURSDAY. THIS SYSTEM WILL BE CAPABLE OF GENERATING SEVERAL INCHES OF ACCUMULATING SNOW OVER PORTIONS OF THE SOUTHWESTERN AND ESPECIALLY CENTRAL MOUNTAINS FROM TUESDAY NIGHT INTO THURSDAY MORNING(I.E. PORTIONS OF PUBLIC ZONES 58/59/60 AND POSSIBLY 66/68 AND 82). IN ADDITION...EVEN A FEW INCHES OF SNOW WILL BE POSSIBLE OVER PORTIONS OF EL PASO AND TELLER COUNTIES AS WELL AS POSSIBLY THE SANGRE DE CRISTO AND WET MOUNTAINS...ESPECIALLY FROM LATER WEDNESDAY INTO WEDNESDAY NIGHT. AT THIS TIME IT APPEARS THAT PRIMARILY WINTER WEATHER ADVISORY SNOW AMOUNTS WILL BE MOST LIKELY WITH THIS EVENT OVER PORTIONS OF PUBLIC ZONES 58/59/60 AND POSSIBLY 66/68 AND 82 FROM TUESDAY NIGHT INTO THURSDAY MORNING...ESPECIALLY IF THE 12Z/28TH ECMWF SOLUTION VERIFIES. ZONE 60 MAY BE THE MOST PRONE TO RECEIVE WINTER STORM WARNING TOTALS WITH THIS EVENT...ONCE AGAIN IF THE 12Z/28TH ECMWF IS CORRECT. WFO PUEBLO WILL MONITOR CLOSELY AND ISSUE NEEDED HIGHLIGHTS AS NEEDED AND AS WE NEAR THIS POTENTIAL EVENT. GUSTY WINDS(AROUND 50 KNOTS AT TIMES)...PRIMARILY FAVORING HIGHER TERRAIN LOCATIONS ARE ALSO ANTICIPATED TUESDAY NIGHT AND THEN AGAIN FROM LATER WEDNESDAY NIGHT INTO THURSDAY NIGHT. AS TOUCHED UPON BRIEFLY EARLIER...A RETURN TO WARMER AND DRIER CONDITIONS SHOULD THEN BE EXPERIENCED OVER THE FORECAST DISTRICT BY THIS WEEKEND AS DRY NORTHWESTERLY TO ZONAL UPPER FLOW DEVELOPS OVER SOUTHERN COLORADO. FINALLY...WARMEST MAXIMUM TEMPERATURES OF THE LONGER TERM ARE EXPECTED THIS WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1106 PM MDT MON OCT 28 2013 KALS...VFR CONDITIONS THROUGH THE FORECAST PERIOD. GUSTY SOUTH- SOUTHWEST WINDS TO NEAR 30 KTS ARE LIKELY TUESDAY AFTERNOON. SHOWERS ARE FORECAST TO DEVELOP OVER THE MOUNTAINS AND SHIFT EAST INTO THE SAN LUIS VALLEY BY EARLY EVENING AND COULD POSSIBLY IMPACT THE TERMINAL. KCOS...CURRENT OBS INDICATE LOWERING CIGS AND VIS. EXPECT THE TREND TO CONTINUE THROUGH THE OVERNIGHT PERIOD WITH LOW STRATUS AND FOG PRODUCING IFR AND PERIODS OF LIFR. CONDITIONS WILL LIKELY REMAIN DEGRADED THROUGH 15Z WITH IMPROVEMENTS THROUGH 18Z TO VFR. ALL SHOWER ACTIVITY IS FORECAST TO REMAIN OVER THE RAMPART RANGE BY LATE AFTERNOON WITH NO IMPACTS EXPECTED AT THIS TIME. KPUB...CIGS CONTINUE TO LOWER THROUGH THE OVERNIGHT HOURS WITH CIGS FALLING TO NEAR 800 FEET. FOG WILL REMAIN POSSIBLE AFTER 08Z. IFR TO LIFR CONDITIONS WILL LIKELY PERSIST THROUGH AROUND 15Z WITH IMPROVEMENTS THROUGH 20Z TO VFR. MOZLEY && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MOZLEY AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
338 AM CDT TUE OCT 29 2013 .DISCUSSION... 337 AM CDT MAIN FORECAST CONCERNS CONTINUE TO BE WITH RAIN POTENTIAL AND MILDER TEMPERATURES ASSOCIATED WITH A STRONG LOW PRESSURE SYSTEM WHICH WILL MOVE THROUGH THE UPPER MIDWEST WEDNESDAY NIGHT THROUGH THURSDAY. SHORT TERM...TODAY THROUGH THURSDAY... UPPER FLOW PATTERN THIS MORNING IS DOMINATED BY A LARGE CLOSED LOW OVER THE INTER-MOUNTAIN WEST...WITH SPLIT BUT MAINLY ZONAL FLOW DOWNSTREAM ACROSS THE EASTERN CONUS. OVERNIGHT WATER VAPOR IMAGERY DEPICTS A STRONG SHORT WAVE PROPAGATING ACROSS THE CENTRAL PLAINS AND INTO THE MID-MISSOURI VALLEY...ALONG A LOW LEVEL BAROCLINIC ZONE ASSOCIATED WITH A STATIONARY SURFACE FRONT WHICH STRETCHES WEST-EAST FROM KANSAS TO THE OHIO VALLEY. FARTHER NORTH...AN ELONGATED AREA OF SURFACE HIGH PRESSURE STRETCHED FROM NEAR LAKE WINNIPEG ACROSS THE NORTHERN GREAT LAKES TO NEW ENGLAND. THE PLAINS SHORT WAVE WILL CONTINUE TO TRACK EASTWARD ALONG THE BAROCLINIC ZONE TODAY...WITH WARM ADVECTION/ISENTROPIC UPGLIDE DEVELOPING ACROSS THE REGION. THE FOCUS FOR STRONGER FORCING AND LOW LEVEL MOISTURE RETURN WILL REMAIN ACROSS FAR SOUTHERN IA/MISSOURI AND DOWNSTATE ILLINOIS THROUGH THIS AFTERNOON HOWEVER...WITH MAINLY JUST MID/HIGH CLOUDINESS EXPECTED ACROSS THE CWA AS LOW LEVEL FLOW BACKS MORE SOUTHEAST. THIS WILL PULL IN DRIER AIR FROM UPSTREAM... AS NOTED IN LAST EVENINGS 00Z SOUNDING FROM WILMINGTON OH. SOME POTENTIAL PROBABLY EXISTS FOR A SPRINKLE OR TWO FROM OUR DEVELOPING MID-DECK LATER TODAY...THOUGH IT APPEARS THAT ORGANIZED MEASURABLE PRECIP CHANCES WILL REMAIN PRETTY LOW WITH THE SUITE OF GUIDANCE NOT PRODUCING QPF. IT DOES APPEAR THAT PRECIP CHANCES WILL INCREASE SLOWLY FROM THE SOUTH TONIGHT...AS THE ELEVATED BAROCLINIC ZONE LIFTS SLOWLY NORTH IN RESPONSE TO PERSISTENT WARM ADVECTION ON SOUTH-SOUTHWEST WINDS. OTHER THAN MOISTURE TRANSPORT/CONVERGENCE ALONG THE ELEVATED WARM FRONT ON THE NOSE OF A 20-25 KT LOW LEVEL JET TONIGHT...LITTLE IN THE WAY OF SHORT WAVE SUPPORT IS NOTED AND HEIGHTS ACTUALLY RISE A BIT WITH WEAK RIDGING DEVELOPING ALOFT. GUIDANCE DOES BRING SOME LIGHT QPF ACROSS THE SOUTHERN PORTIONS OF THE CWA OVERNIGHT...THOUGH HAVE GENERALLY LOWERED POPS SIGNIFICANTLY FROM PREVIOUS FORECAST BASED ON CURRENT GUIDANCE TRENDS. THE WESTERN TROUGH BEGINS TO OPEN UP AND MOVE EAST WEDNESDAY AND WEDNESDAY NIGHT...WITH RENEWED SURFACE LOW PRESSURE DEVELOPMENT ACROSS THE CENTRAL PLAINS. THE LOW WILL LIFT ACROSS THE MID-MISSOURI VALLEY BY WEDNESDAY EVENING AND INTO THE UPPER MISSISSIPPI VALLEY BY THURSDAY MORNING...WITH SEVERAL MODELS DEPICTING A SHORT WAVE APPROACHING THE CWA WEDNESDAY AFTERNOON/EVENING. A MUCH STRONGER 40-50 KT 850 MB JET IS INDICATED WEDNESDAY NIGHT WHICH IMPINGES ON THE WARM FRONTAL ZONE AS IT LIFTS NORTH...SUGGESTING RAPIDLY INCREASING POTENTIAL FOR RAIN AND A FEW THUNDERSTORMS BY LATE WEDNESDAY AND CONTINUING INTO THURSDAY IN THE WARM SECTOR AHEAD OF THE APPROACHING COLD FRONT. STRONG MOISTURE ADVECTION...PWATS APPROACHING 1.5 INCHES...AND SURFACE DEW POINT TEMPS IN THE UPPER 50S...SUPPORT FAIRLY HIGH POPS DURING THIS PERIOD. AS FOR TEMPERATURES...INCREASING CLOUD COVER AND EAST-SOUTHEAST LOW LEVEL WINDS ARE EXPECTED TO KEEP RISES IN CHECK DESPITE WARMING ALOFT TODAY. WARMER TEMPS...IN THE 60S...WILL SPREAD NORTH WITH THE WARM FRONT INTO THE SOUTHERN CWA WEDNESDAY AND ACROSS THE ENTIRE AREA THURSDAY. RISING TEMPS ARE LIKELY WEDNESDAY NIGHT. LONG TERM...FRIDAY-MONDAY... THE LARGE SCALE UPPER TROUGH WILL LINGER ACROSS THE REGION FRIDAY AND SATURDAY AS ADDITIONAL SHORT WAVE ENERGY DIGS IN FROM THE NORTHWEST. COOL ADVECTION AND CYCLONIC LOW LEVEL FLOW IN SURFACE TROUGHING OVER THE LAKES WILL LIKELY SUPPORT CONSIDERABLE CLOUD COVER INITIALLY...WITH THE POTENTIAL FOR SOME SPRINKLES/SHOWERS ESPECIALLY FRIDAY NIGHT AND SATURDAY WITH A SECONDARY PUSH OF COLDER AIR. SURFACE HIGH PRESSURE THEN EVENTUALLY SPREADS ACROSS THE REGION LATE SATURDAY NIGHT AND SUNDAY. LONG RANGE MODEL SOLUTIONS MOVE THE HIGH QUICKLY OFF TO THE EAST SUNDAY NIGHT...WITH ANOTHER LOW PASSING NORTHWEST OF THE FORECAST AREA MONDAY. THIS SETS UP ANOTHER PERIOD OF SOUTH FLOW AND A RETURN OF RAIN CHANCES ESPECIALLY WEST ON MONDAY. TEMPS COOL TO THE UPPER 40S/LOW 50S OVER THE WEEKEND BEFORE MODERATING MONDAY. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * POSSIBLE MVFR CEILINGS EARLY THIS NEXT HOUR FOR BOTH ORD/MDW. * NORTHEAST WINDS BECOMING MORE EASTERLY LATER THIS MORNING...AND THEN EVENTUALLY SOUTHEAST BY MID/LATE MORNING. RODRIGUEZ //DISCUSSION...UPDATED 06Z... LATEST OBS AND SATELLITE IMAGERY DEPICTING LOW LEVEL STRATUS LINGERING ACROSS PORTIONS OF NORTHEAST ILLINOIS EARLY THIS MORNING. ALTHOUGH...FLOW WILL BECOME MORE EAST AND THEN SOUTHEAST THROUGH THIS MORNING WITH MOST OF THIS CLOUD COVER TO MOVE NORTH OF THE TERMINALS. THIS TREND SHOULD OCCUR HERE IN THE NEAR TERM BUT AS THIS OCCURS...THESE MVFR CEILINGS COULD STILL MOVE ACROSS ORD/MDW. SO HAVE INCLUDED A TEMPO GROUP FOR THIS FIRST HOUR TO SHOW THIS POSSIBILITY. WITH THESE LOW CEILINGS TO THE NORTH...ONLY MID/HIGH LEVEL CLOUD COVER EXPECTED THROUGH THE FORECAST PERIOD AND WITH ANY PRECIP APPROACHING LATER THIS EVENING TO STAY SOUTHWEST OF ALL THE TERMINALS. WINDS WILL CONTINUE A STEADY TREND FROM THE NORTHEAST TO THE EAST AND SOUTHEAST THIS MORNING...MAINTAINING THIS DIRECTION THROUGH MOST OF THE DAY BEFORE TURNING MORE SOUTH SOUTHEAST LATER THIS EVENING. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE WITH CEILING TRENDS. * HIGH CONFIDENCE WITH WIND SPEED/DIRECTION. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z SUNDAY...UPDATED 00Z... WEDNESDAY...CHC OF RAIN. SLIGHT CHC OF THUNDER LATE WED NGT. MVFR LIKELY WITH OCCASIONAL IFR CIGS. THURSDAY...RAIN LIKELY W/SLIGHT CHC OF THUNDER. MVFR CIGS. FRIDAY...SLIGHT CHANCE OF RAIN. MVFR POSSIBLE. SATURDAY THROUGH SUNDAY...VFR. BEACHLER && .MARINE... 226 PM CDT BREEZY CONDITIONS EXPECTED THROUGH MUCH OF THE WEEK...WITH PERIOD OF GALES POSSIBLE WEDNESDAY NIGHT INTO THURSDAY. TODAY...A COLD FRONT HAS CLEARED THE SOUTH END OF LAKE MICHIGAN WITH STRONG HIGH PRESSURE BUILDING EAST ACROSS THE CANADIAN PRAIRIES. THE HIGH WILL SHIFT ESE ACROSS THE EASTERN GREAT LAKES BY LATE TUESDAY...BUT THE GRADIENT WILL REMAIN MODERATELY TIGHT ACROSS SOUTHERN LAKE MICHIGAN WHERE WINDS WILL VEER FROM THE NORTHEAST TODAY TO SOUTHEAST TUESDAY NIGHT...BUT GENERALLY STAY IN THE 15 TO 20 KT RANGE. WINDS WILL BE WEAKER ACROSS THE NORTH HALF OF THE LAKE CLOSER TO THE RIDGE AXIS. MIDWEEK...DEEP LOW PRESSURE IS EXPECTED TO DEVELOP FROM THE PLAINS INTO THE MIDWEST. THIS LOW WILL STILL BE DEEPENING AS IT MOVES ACROSS THE UPPER PENINSULA OF MICHIGAN THURSDAY LEADING TO STRONG SOUTHERLY WINDS AHEAD OF THE LOW. IT APPEARS THAT THE GALES MAY OCCUR WEDNESDAY NIGHT INTO THURSDAY. A COLD FRONT WILL SWEEP ACROSS THE LAKE ON THURSDAY EVENING WITH WINDS TURNING WEST TO NORTHWEST AND REMAINING ELEVATED AROUND 30 KTS THROUGH SATURDAY. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 3 PM TUESDAY. && $$ 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 254 AM CDT Tue Oct 29 2013 .DISCUSSION... ISSUED 254 AM CDT Tue Oct 29 2013 Main challenges with this forecast package are rain chances today through Thursday and the potential for severe weather Thursday afternoon. Current upper air pattern features the main branch of the polar jet flowing well to the north across central and eastern Canada. Further southwest, a deep closed low has become cut-off from the flow and is now meandering eastward across the Great Basin. This low will be the dominant weather-maker across central Illinois for the next several days as it slowly makes its way eastward. SHORT TERM...Today through Thursday Weak frontal boundary that dropped into the area yesterday afternoon has now become stationary just north of the Ohio River. To the north of the front, a dry E/NE flow prevails across central Illinois early this morning, with 07z/2am dewpoints mainly in the 30s. This dry airmass will inhibit the eastward spread of precip currently developing ahead of a weak short-wave trough over the Plains. The onset of precip has been gradually delayed with each model run over the past couple of days, with the 00z Oct 29 suite now keeping the KILX CWA dry until afternoon. HRRR suggests light showers may arrive in the Winchester/Jacksonville area around midday, then will spread eastward to the Indiana border toward evening. Will therefore go with a dry forecast this morning, then will focus highest POPs across the southern CWA in closer proximity to the stalled front this afternoon. Further north toward the I-74 corridor, little or no precip is expected today. Once this initial wave passes, short-wave ridging in its wake will keep rain chances low tonight. Despite lack of upper forcing, moistening airmass and presence of surface boundary support low chance POPs through the night. As Great Basin upper low begins to approach from the west, surface front will get nudged northward on Wednesday. Thanks to southerly winds south of the boundary, afternoon high temperatures will rise into the upper 60s and lower 70s. In addition, showers and thunderstorms will become more widespread during the afternoon, particularly along/west of the Illinois River. Main rain/convective event is still slated for Wednesday night into Thursday as strong cold front approaches from the west. Models are generally in good agreement with their mass fields, but still have some minor differences in QPF. As boundary nears, copious amounts of moisture will advect northward from the Gulf of Mexico, with precipitable water values nearing 1.50 on Thursday. Given ample moisture, strong upper dynamics, and presence of approaching cold front, will carry likely to categorical POPs across the board Wednesday night and Thursday. Total rainfall with this system will generally range from 1 to 1.50, with isolated higher amounts within stronger storms. Strong to potentially severe thunderstorms will be possible Thursday afternoon as the front swings through the region: however, details remain uncertain at this point. NAM/GFS forecast soundings indicate a low CAPE/high shear environment in the warm sector ahead of the front, with the greatest instability focused further southeast from the Ohio River Valley to the western Gulf Coast. Latest DAY 3 convective outlook from SPC highlights this area for potential severe, but can not rule out a few strong storms with damaging wind gusts further north across east-central and southeast Illinois, particularly given impressive 0-6km bulk shear values of 70 to 75kt. LONG TERM...Friday through Monday Cooler and drier weather will return by the end of the week, as upper trough digs across the Great Lakes. GFS/ECMWF both suggest clouds and a few showers will be possible across northeast Illinois into north-central Indiana Friday into Saturday: however, think these will remain northeast of central Illinois. High pressure building into the Midwest will be the dominant weather feature in the extended, resulting in cool highs in the 50s Friday through Monday. Next chance for rain will likely hold off until Tuesday when another system approaches from the west. Barnes && .AVIATION... ISSUED 1151 PM CDT Mon Oct 28 2013 VFR conditions will prevail at all TAF sites next 24hrs. High cirrus will continue overnight and into the morning hours. Then mid clouds will overspread the TAF sites during the late morning. As the first wave approaches from the west and tries to make its way over the mid level ridge, pcpn will diminish as it moves toward the area. So, initial pcpn will go to saturate the lower levels first, in the afternoon. So will begin to see some lower clouds around 5kft in the afternoon with little bit lower mid clouds. Then by evening, after 00Z, lower clouds will thicken up and middle clouds will get lower too. At this point, unsure how widespread pcpn will be. Thinking it could be very light or scattered, so will have just VCSH for now. Winds will be northeasterly overnight and then become southeasterly tomorrow afternoon and continue into the evening hours. Wind speeds will generally be below 10kts. Auten && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
428 AM EDT TUE OCT 29 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 426 AM EDT TUE OCT 29 2013 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALF OVER THE UPR GREAT LKS BTWN UPR TROF CENTERED OVER ERN HUDSON BAY AND A RDG IN THE PLAINS. SPRAWLING SFC HI PRES/DRY AIRMASS WITH PWAT AOB 0.25 INCH IS CENTERED OVER THE UPR LKS...BRINGING QUIET WX TO THE CWA. ALTHOUGH SOME HI CLDS IN THE RRQ OF A 100KT H3 JET MAX ARE STREAMING INTO THE CWA...TEMPS HAVE FALLEN SHARPLY AND INTO THE TEENS OVER INTERIOR LOCATIONS WITH LIGHT WINDS UNDER THE SFC HI. MORE SC DOES LINGER OVER THE E NEAR LK SUP WITH LLVL NW FLOW E OF THE HI CENTER...AND THESE CLDS HAVE RESTRICTED THE DIURNAL TEMP FALL IN THIS AREA. LOOKING TO THE W...DESPITE SOME DRY LLVL AIR SHOWN ON THE 00Z ABERDEEN SDAKOTA AND BISMARK RAOBS...THERE IS AN AREA OF -SN OVER SRN NDAKOTA AND NRN SDAKOTA. THE PRIMARY FORCING MECHANISMS APPEAR TO BE SOME ISENTROPIC ASCENT ON THE 295-300K SFCS AS WELL AS A BAND OF H7-75 FGEN UNDER UPR DVGC IN RRQ OF THE H3 JET MAX. AN UPSLOPE SFC E WIND ALSO APPEARS TO BE AIDING IN THE LLVL MOISTENING DESPITE THE LLVL DRY AIR FEED OUT OF THE E ON THE SRN FLANK OF THE SFC HI PRES RDG. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE PCPN CHCS OVER UPR MI RELATED TO THE UPSTREAM DISTURBANCE CAUSING SOME -SN IN THE NRN PLAINS. TODAY...AS THE UPR JET CORE SHIFTS TO THE E TODAY...EXPECT THICKENING HI/MID CLDS UNDER ACCOMPANYING UPR DVGC IN THE RRQ OF THIS FEATURE AS SFC HI PRES RDG HANGS BACK INTO THE UPR LKS. AS THE FLOW BACKS TO THE SW...ANY LK CLDS OVER THE E SHOULD SHIFT BACK INTO THE LK. MOST OF THE LARGER SCALE MODELS SHOW SOME PCPN ARRIVING NEAR THE WI BORDER AFT 18Z AS BAND OF H7-75 FGEN SHIFTS TO THE NE. HOWEVER...MOST OF THE HIER RES MODELS SHOW ONLY PATCHY QPF. BIGGEST IMPEDIMENT WL BE LINGERING LLVL DRY AIR AND ABSENCE OF ANY SGNFT UPSLOPE WIND COMPONENT THAT IS AIDING THE LLVL MOISTENING UPSTREAM. OTHER NEGATIVES INCLUDE QUICK DEPARTURE OF UPR JET CORE TO THE E AFT 18Z AND WEAKENING MID LVL ISENTROPIC ASCENT. SO OPTED TO CUT BACK ON POPS OVER THE N HALF OF THE CWA...WITH HIER POPS FOR SOME -SN/-RA NEAR THE WI BORDER...ESPECIALLY IN MNM COUNTY/SCENTRAL WITH A LGT UPSLOPE SE WIND JUST TO THE S OF SFC RDG AXIS. THICKENING CLDS SHOULD RESTRICT THE DIURNAL TEMP RECOVERY...SO TENDED TOWARD THE LOWER END OF GUIDANCE FOR MAX TEMPS. TONIGHT...SUPPORT FOR PCPN IN THE EVNG WL FADE WITH THE ARRIVAL OF LARGER SCALE QVECTOR DVGC/UPR CNVGC IN ADVANCE OF THE UPR RDG MOVING NEWD FM THE PLAINS. ENDED THIS LINGERING PCPN OVER MAINLY THE SCENTRAL BY THE EARLY MRNG HRS ON WED. DESPITE THE VIGOROUS DRYING ALF...MOST MODEL FCST SDNGS INDICATE MSTR WL LINGER IN THE LOWER LVLS...ESPECIALLY OVER THE SCENTRAL WHERE PCPN IS MOST LIKELY TO FALL TODAY. SO MAINTAINED CLDY CONDITIONS IN THIS AREA...WITH PARTIAL CLRG OVER THE NW. THE LOWEST TEMPS SHOULD OCCUR OVER THE INTERIOR NW WHERE SOME CLRG IS LIKELY. IF THE CLDS BREAK UP ELSEWHERE...MIN TEMPS MAY HAVE TO BE ADJUSTED DOWN WITH LGT WINDS UNDER LINGERING SFC RDG AXIS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 426 AM EDT TUE OCT 29 2013 MID-UPR LEVEL TROUGH SLIDES EAST ACROSS THE NATIONS MID SECTION WEDNESDAY INTO THURSDAY. INITIAL TROUGHING LIFTS ACROSS GREAT LAKES TOWARD EASTERN CANADA FRIDAY INTO SATURDAY WHILE SOUTHERN PORTION OF THE TROUGH DOES NOT EXIT EASTERN CONUS UNTIL LATER IN THE WEEKEND. AS THE LEADING TROUGH LIFTS TOWARD GREAT LAKES...SFC LOW PRESSURE TROUGH OVER THE PLAINS ON WEDNESDAY DEVELOPS INTO 1000MB SFC LOW OVER UPR GREAT LAKES BY 12Z THURSDAY...THEN DEEPENS TO 975-980MB LOW BTWN LK SUPERIOR AND JAMES BAY BY 12Z FRIDAY. AS IT HAS LOOKED FOR A WHILE...MAIN PERIOD OF PRECIP...IN THE FORM OF RAIN...OCCURS LATER WEDNESDAY NIGHT INTO THURSDAY WITH MORE SHOWERY PRECIP TAKING OVER IN WAKE OF THE LOW LATER THURSDAY NIGHT INTO FRIDAY. SOUNDINGS FOR WEDNESDAY INDICATE MOISTURE BLO H7 WITH MINIMAL LIFT. THINKING THE LOW-LEVEL MOISTURE IS OVERDONE...BUT DO EXPECT CLOUDS TO THICKEN THROUGHOUT THE DAY AS WARM AIR ADVECTION DEVELOPS OUT AHEAD OF SFC LOW IN THE PLAINS. COULD BE JUST ENOUGH WEAK LIFT AND MOISTURE ADVECTION TO FORM SOME LGT RAIN LATER IN THE WEST OVER THE WEST AND SOUTH...NOT A BIG DEAL AT ALL AS PRIMARY AREA OF RAIN WILL NOT ARRIVE UNTIL LATER WEDNESDAY NIGHT. GIVEN THE CLOUDS...MAX TEMPS ON WEDNESDAY IN THE LOW-MID 40S. TEMPS SHOULD THEN STAY STEADY OR SLOWLY RISE THROUGH WEDNESDAY NIGHT. TIMING OF PRECIP ON WEDNESDAY NIGHT A BIT SLOWER THAN MODELS SHOWED 24 HR AGO. DIVERGENCE ALOFT ON NOSE OF 250MB JET STREAK LIFTING ACROSS UPR LAKES INTERACTS WITH H85 AND H7 MOISTURE ADVECTION TO THE NORTH OF SFC-H85 LOWS. EXPECT BRIEF PERIOD OF MODERATE RAIN TO SWEEP FROM SOUTH TO NORTH ACROSS CWA. EVEN WITH RAIN MOVING THROUGH...PUT A MENTION OF FOG IN OVERNIGHT WEDNESDAY NIGHT INTO THURSDAY MORNING AS DWPNTS RISING INTO THE 40S TO LOWER 50S WILL BE RIDING OVER COLDER GROUND SFC WITH 2 INCH SOIL TEMPS WELL BLO 40 THE LAST WEEK OR SO. IF THE RAIN EXITS QUICKER...THEN THE FOG WOULD LIKELY BECOME MORE WIDESPREAD. DRY SLOT/MID-LEVEL DRYING TAPERS OFF RAIN ON THURSDAY MORNING. AS LONG AS WINDS ARE NOT TOO STRONG FOG COULD PERSIST OVER THE UPSLOPE AREAS OF CNTRL UPR MICHIGAN INTO THE MIDDLE PART OF THE DAY. WINDS SHIFT TO WEST AND START TO INCREASE IN THE AFTN AS SFC LOW CENTER MOVES TO CNTRL OR EASTERN LK SUPERIOR WHILE DEEPENING. DESPITE CLOUDS/FOG AND SPOTTY RAIN...MAX TEMPS WILL STILL PUSH WELL INTO THE 50S FROM SHEAR ADVECTION ALONE IN THE WARM SECTOR OF THE SFC LOW. ANOTHER WAVE OF RAIN COULD DEVELOP LATE AFTN/THURSDAY EVENING AS PRIMARY HEIGHT FALLS AND DEEP LAYER Q-VECTOR CONVERGENCE SWEEPS IN OVER MAINLY SOUTH AND EAST CWA. KEPT POPS HIGHEST TO THE EAST OF MQT AND ESC AS THAT IS WHERE LARGER SCALE FORCING INTERACTS WITH BETTER MOISTURE ADVECTION. BASED ON GRADIENT OF MID-LEVEL MOISTURE AND FCST H7-H5 LAPSE RATES...THINKING BETTER CHANCES OF TSRA WILL REMAIN TO THE SOUTH AND EAST OF CWA LATER THURSDAY AFTN INTO EVENING. STRONGER SHORTWAVE/DEEP MOISTURE MAY DROP ACROSS GREAT LAKES FRIDAY NIGHT INTO SATURDAY WHILE COOLER AIRMASS LINGERS AS H85 TEMPS FALL TO -4C TO -6C BY 12Z SATURDAY. NW-NNW CYCLONIC FLOW AT 1000-850MB PERSISTS THROUGH SATURDAY SUGGESTING THERE WILL LIKELY BE SOME LAKE ENHANCED PRECIP. 1000-850MB/H85-H7 THICKNESSES AND FORECAST SFC TEMPS POINT TO MAINLY SNOW FOR PTYPE FRIDAY NIGHT INTO SATURDAY MORNING OVER THE WEST WITH RAIN/SNOW MIX FARTHER EAST. DETAILS WILL NEED TO BE SORTED OUT LATER THIS WEEK...BUT DOES SEEM THAT THE FRIDAY NIGHT INTO SATURDAY MORNING PERIOD HOLDS SOME POTENTIAL FOR ACCUMULATING SNOW OVER THE HIGHER TERRAIN OF WEST AND NORTHWEST UPR MICHIGAN. TEMPS COOL FURTHER INTO SATURDAY NIGHT BUT DEEPER MOISTURE AND CYCLONIC FLOW WILL BE EASING AS SFC-H85 RIDGE NEARS FROM THE WEST. LAKE EFFECT SNOW SHOWERS COULD CONTINUE MOST OF THE NIGHT...MAINLY FOR NW FLOW AREAS TO THE EAST OF MARQUETTE. SUNDAY IS A TRANSITION DAY IN WEATHER. EASTERN CONUS TROUGH EDGES EAST AS STRONGER JET ENERGY MOVES TO FRONT SIDE OF TROUGH WHICH THEN CLEARS WAY FOR WESTERN CONUS TROUGH TO EXPAND TOWARD ROCKIES AND RIDGING TO EXPAND ACROSS THE GREAT LAKES. RIDGING LOOKS BRIEF THOUGH AS THE TROUGHING OVER THE WESTERN CONUS EXPANDS INTO THE PLAINS LEADING TO A POTENTIALLY ACTIVE SW FLOW PATTERN ACROSS THE GREAT LAKES BY EARLY NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 125 AM EDT TUE OCT 29 2013 ALTHOUGH THERE WL BE A TREND TOWARD THICKENING HI/MID CLDS WELL N OF A WARM FNT...EXPECT VFR CONDITIONS AND LGT WINDS UNDER LINGERING SFC RDG AXIS THRU AT LEAST MOST OF THE DAY. AN UPR DISTURBANCE WL BRING SOME -SN TO MAINLY THE S HALF OF UPR MI LATE THIS AFTN/EVNG...AND CONDITIONS MAY DROP TO MVFR AT THE MORE SRN SAW/IWD LOCATIONS DURING THIS TIME IF THE LLVL DRY AIR IS MOISTENED SUFFICIENTLY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 426 AM EDT TUE OCT 29 2013 LIGHT WINDS LESS THAN 20 KTS THROUGH WEDNESDAY AS HIGH PRESSURE RIDGE OVER THE AREA SLOWLY MOVES TOWARD THE EAST COAST. LOW PRESSURE DEVELOPING OVER THE PLAINS ON WEDNESDAY WILL LIFT TOWARD THE UPPER GREAT LAKES ON THURSDAY THEN DEEPEN AS IT MOVES INTO QUEBEC ON FRIDAY. SE-E WINDS 20-25 KTS WEDNESDAY NIGHT INTO THURSDAY AHEAD OF THE SYSTEM...THEN AFTER THE LOW MOVES EAST OF THE LAKE...EXPECT WINDS TO SHIFT NW 25-30 KTS THURSDAY NIGHT THROUGH SATURDAY AS COLDER AIR PLUNGES ACROSS THE UPPER LAKES REGION. WINDS DIMINISH ON SUNDAY WITH ARRIVAL OF HIGH PRESSURE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...KC MARINE...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
346 AM CDT TUE OCT 29 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CDT TUE OCT 29 2013 LIGHT PRECIP WILL OVERSPREAD THE AREA THIS MORNING. WHILE THE CHANCE OF RECEIVING MEASURABLE PRECIP IS HIGH...PRECIP AMOUNTS WILL BE LOW /LIQUID AMOUNTS UNDER ONE TENTH OF AN INCH AND SNOW ACCUMS ONE HALF INCH OR LESS/. RAIN AND SNOW WILL REMAIN POSSIBLE ACROSS THE FORECAST AREA THROUGH THIS MORNING...AND THEN MAINLY NORTH OF INTERSTATE 94 THIS AFTERNOON. THERE WILL REMAIN A THREAT FOR LIGHT FREEZING PRECIP AND SLEET OVER FAR SOUTHWEST AND WEST CENTRAL MN FOR A FEW HOURS AFTER DAYBREAK...WHERE BRIGHT BANDING HAS BEEN OBSERVED ON RADAR OVERNIGHT. LOW CLOUDS MOVE IN TONIGHT...WITH FAINT ISENTROPIC UPGLIDE INDICATING THE POTENTIAL FOR OCCASIONAL DRIZZLE OR VERY LIGHT RAIN /POSSIBLY WITH SOME VERY LIGHT SNOW OVER CENTRAL MN/. TEMPERATURES WILL REMAIN FAIRLY STATIC OVER THE NEXT 24 HOURS...WITH HIGHS IN THE UPPER 30S TO UPPER 40S AND LOWS TONIGHT IN THE LOWER 30S TO LOWER 40S. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 345 AM CDT TUE OCT 29 2013 MAIN UPPER SYSTEM LIFTS NORTHEAST WEDNESDAY AFTERNOON INTO THURSDAY. WILL INCREASE POPS FROM SOUTHWEST TO NORTHEAST DURING THE PERIOD...WITH A PERIOD OF CATEGORICAL POPS INDICATED. LATEST AVAILABLE SREF PROBABILITY OF THUNDER BRINGS SMALL CHANCE INTO FAR SOUTHERN MINNESOTA WEDNESDAY AFTERNOON...AND SPREADS IT A BIT NORTHEAST AND WEAKENS OVERNIGHT. THIS IS IN LINE WITH THE WEAK MIXED LAYER/MOST UNSTABLE CAPE OF 200-400 J/KG PROGGED OFF THE GFS AND THE BEST LI`S AS LOW AS MINUS 4. THIS SHOULD BE ENOUGH AT LEAST FOR AN ISOLATED THUNDER MENTION OVERNIGHT. FAIRLY SIGNIFICANT MOISTURE TRANSPORT LIFTS NORTH ACROSS SOUTHEAST MN FROM 00Z.31 THROUGH 06Z.31 AS 35 KT LOW LEVEL JET LIFTS AND IS SHUNTED TO THE EAST. AS THE UPPER TROUGH LIFTS NORTHEAST...STRONG HEIGHT FALL CENTER OF OVER 120 DECAMETERS MOVES ACROSS THE AREA AS 130 KT UPPER JET NOSES INTO THE AREA. 24 HOUR QPF AMOUNTS 12Z WED THROUGH 12Z THU SHOULD RANGE AROUND ONE HALF TO THREE QUARTERS OF AN INCH OVER MUCH OF THE CENTRAL AND EASTERN PORTIONS OF THE CWA. SOME WRAPAROUND PRECIPITATION POSSIBLE INTO THURSDAY AS THE SYSTEM EXITS TO THE EAST. SHOULD WANE BY LATE AFTERNOON OVER THE WEST AND BY EVENING INTO HE EAST. MODELS CONTINUE TO SHOW POTENTIAL FROM ANOTHER SHORT WAVE DROPPING IN FROM THE NORTHWEST FOR FRIDAY. WILL HAVE TO MONITOR THIS FOR FURTHER POSSIBILITY OF ANOTHER LIGHT SHOWERY EVENT MOVING ACROSS THE CWA FRIDAY INTO FRIDAY NIGHT. ANY PRECIPITATION SHOULD BE LIGHT IF IT DOES OCCUR. RIDGING ALOFT DEVELOPS THEN INTO THE WEEKEND WITH TEMPERATURES WARMING BACK THROUGH THE LOWER 50S. SHOULD REMAIN DRY DURING THE PERIOD AS WELL. THIS MAY LINGER INTO EARLY NEXT WEEK AS WELL...AS MODELS CONTINUE TO DEVELOP ANOTHER SIGNIFICANT TROUGH OVER THE WESTERN CONUS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1033 PM CDT MON OCT 28 2013 LOOKING AT THE LAST FEW RUNS OF THE HRRR...ALONG WITH THE 00Z NAM...IS LOOKING LIKE TONIGHT INTO TUESDAYS PRECIP EVENT MAY TURN OUT TO BE MUCH ADO ABOUT NOTHING. DID NOT CHANGE INHERITED TAFS MUCH...OTHER THAN TO REMOVE SNOW MENTION FROM EAU. GIVEN THE WIDE RANGE OF SOLUTIONS RANGING FROM NOT MUCH HAPPENING /HRRR/ TO A GOOD AMOUNT OF PRECIP MOVING THROUGH /18Z GFS/...HAVE CONTINUED TO BE RATHER CONSERVATIVE WITH PRECIP IN TAFS. BASED ON ALL THE DRY AIR IN THE MPX 00Z SOUNDING...IT MAY BE TOUGH TO GET MUCH OF ANYTHING TO THE GROUND...SO CONTINUED TO FAVOR THE DRIER END OF THINGS RIGHT NOW. FOR CIGS...HRRR/RAP WOULD SUGGEST MVFR CIGS IN TAFS ARE WAY OVER DONE FOR TODAY OUTSIDE OF WRN MN...WITH THE RAP SHOWING MOST MPX TAFS ENJOYING VFR CONDS TUESDAY. TUESDAY NIGHT...A MORE SIGNIFICANT PUSH OF MOISTURE WILL BE ARRIVING FROM THE SOUTH...AND WITH THAT...LOOKS LIKELY THAT ALL TERMINALS WILL EVENTUALLY END UP WITH IFR OR LOWER CIGS AT SOME POINT TUESDAY NIGHT. KMSP...CONFIDENCE BEGINNING TO DECREASE IN MSP SEEING ANY PRECIP TUE MORNING. STILL LOOKS TO BE A WINDOW FROM ABOUT 12-16Z WHERE A BRIEF RA OR SN SHOWER COULD BE SEEN...BUT LATEST RUNS OF THE NAM/HRRR DO NOT LEAVE MUCH HOPE FOR THAT OCCURRING. IN ADDITION...THE RAP WOULD SAY OTHER THAN THAT 12-16Z PRECIP WINDOW...CIGS WILL BE VFR ON TUESDAY...SO THE PROGRESSION OF MVFR CIGS TO THE SW WILL HAVE TO BE WATCHED CLOSELY AS CONDITIONS MAY BE SIGNIFICANTLY BETTER THAN CURRENTLY INDICATED...UNTIL TUESDAY NIGHT AT LEAST. /OUTLOOK FOR KMSP/ WED...MVFR OR LOWER CIGS/VIS WITH RA LIKELY IN AFTN. WINDS E 10KTS. THU...MVFR/IFR CIGS WITH -RA ENDING IN MRNG. WINDS BCMG W 10-15KTS. FRI...MVFR CIGS POSSIBLE. WINDS W 15G25KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...LS LONG TERM...DWE AVIATION...MPG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
344 AM CDT TUE OCT 29 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 338 AM CDT TUE OCT 29 2013 THE DEEP H500 MB UPPER LEVEL LOW ACROSS THE WESTERN U.S. IS EXPECTED TO LIFT SLOWLY NORTHEAST INTO WRN WY BY 12Z WEDNESDAY. THE MODELS ARE STRENGTHENING THE WARM AIR ADVECTION FROM 850 MB TO 700 MB AS THE LOW LIFTS NORTH BUT REMAIN WEST OF THE FORECAST AREA. THUS THE THREAT OF FREEZING PRECIPITATION WOULD APPEAR TO BE DECREASING SOMEWHAT. THE MODELS SHOW A STRONG DRY SLOW WORKING INTO THE FCST AREA BETWEEN 850-700MB DURING THE DAY TODAY. AS THE UPPER LEVEL COLD POOL NOSES INTO WYOMING TONIGHT...STEEPENING LAPSES MIGHT SUPPORT AN ORGANIZED ROUND OF ACCUMULATING ICE ACROSS THE PANHANDLE AND PERHAPS INTO WESTERN NEBRASKA. TEMPERATURES AT 700 MB IN THESE AREAS COOL TO -2C TO -4C WHICH WOULD NOT SUPPORT RAPID SNOW GROWTH AND GIVEN THE STRENGTHENING WARM AIR ADVECTION AT 850MB...ALL MODELS ARE ABOVE FREEZING 1C TO 4C...FREEZING RAIN WOULD APPEAR TO BE THE ONLY THREAT. NOTE THE BEST GUESS AT MIN TEMPERATURES WEDNESDAY MORNING PRODUCED LOWS NEAR 30 ACROSS THE NORTHWEST ZONES WITH A FREEZING LINE RUNNING FROM ROUGHLY BIG SPRINGS TO AINSWORTH. HIGHS TODAY RISE TO THE MID 30S ACROSS SHERIDAN AND CHERRY COUNTIES. THE RAP MODEL PRODUCED HIGHS AROUND 33 IN THAT AREA THIS AFTERNOON AND THE HRRR SHOWED 35F. WITH LOWS FALLING TO AROUND 30 TONIGHT...IT WOULD APPEAR ABOUT 8 TO 10 HOURS OF SUBFREEZING WEATHER COULD DEVELOP WHICH WOULD NECESSITATE ANOTHER WINTER WEATHER ADVISORY ACROSS SHERIDAN AND CHERRY COUNTIES. TEMPERATURES TODAY SHOULD RISE ABOVE THE FREEZING MARK AROUND NOON IN THIS AREA AND WE ARE FORECASTING WARMER LOWS TONIGHT THAN ARE OCCURRING THIS MORNING. GIVEN THE DRY AIR MOVING IN ALOFT AHEAD OF THE UPPER LOW...FOG COULD BECOME A BIT MORE WIDESPREAD TONIGHT BUT MAINLY EAST OF HIGHWAY 83 AS SUGGESTED IN THE 850-700MB MOISTURE FIELDS. DRIZZLE WOULD APPEAR TO BE THE OPERATIVE PRECIPITATION MODE WITH THE SHALLOW MOISTURE PROFILES ALONG AND EAST OF HIGHWAY 83 BUT SOME SOLNS LIKE THE GFS DEVELOP WIDESPREAD LIGHT RAIN ALONG AND EAST OF HIGHWAY 83. THE OTHER MODELS DO THE SAME BUT ARE FARTHER EAST FAVORING CENTRAL AND EASTERN NEB WITH THIS RAIN. IT LOOKS LIKES THE GFS IS MAINTAINING A STRONGLY BACK LOW LEVEL FLOW TONIGHT WHILE THE NAM FOR EXAMPLE VEERS THE 850 WINDS A BIT MORE TOWARD ERN NEB. THE 305K ISENTROPIC MOISTURE TRANSPORT VECTORS IN BOTH MODELS IS DIRECTED TOWARD EASTERN AND CNTL NEB. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 338 AM CDT TUE OCT 29 2013 STORM SYSTEM WILL CONTINUE MOVING THROUGH THE CENTRAL AND NORTHERN PLAINS DURING THE DAY WEDNESDAY...EXITING TO THE NORTHEAST WEDNESDAY NIGHT. AS THE UPPER TROUGH AXIS CROSSES THE AREA WEDNESDAY...SHOWERS WILL CONTINUE TO BE POSSIBLE. WARM AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL CONTINUE TO KEEP MOST OF THE PRECIPITATION IN LIQUID FORM. REALLY LITTLE CHANCE OF SNOW...AS ALL MODELS KEEP TEMPERATURES AT 850MB ABOVE FREEZING. AT THE SURFACE HOWEVER...SHALLOW ARCTIC AIR WILL REMAIN ACROSS THE AREA...WITH TEMPERATURES WEDNESDAY MORNING NEAR OR A FEW DEGREES BELOW FREEZING ACROSS PORTIONS OF NORTHERN AND NORTHWEST NEBRASKA. FREEZING RAIN WILL LIKELY BEGIN THE DAY...BUT WILL QUICKLY CHANGE TO RAIN AS TEMPERATURES WARM ABOVE FREEZING BY MID MORNING. FARTHER EAST ACROSS CENTRAL AND SOUTHWEST NEBRASKA...SUFFICIENT MID LEVEL INSTABILITY WARRANTS A THUNDER MENTION DURING THE MORNING. BY AFTERNOON...DRY AIR IN THE MID LEVELS SPREADS NORTHEAST...ENDING PRECIPITATION FROM SOUTHWEST TO NORTHEAST. SKIES BEGIN TO CLEAR WEDNESDAY NIGHT...WITH DOWNSLOPE FLOW AND SUNNY SKIES BOOSTING HIGHS THURSDAY INTO THE 50S TO NEAR 60. DRY AND MILD WEATHER WILL CONTINUE THROUGH THE WEEKEND...AHEAD OF THE NEXT UPPER TROUGH AND POTENTIAL PRECIPITATION EARLY NEXT WEEK. DETAILS REMAIN SKETCHY WITH THIS NEXT SYSTEM...AND WILL ONLY CARRY SLIGHT CHANCES FOR RAIN/SNOW AT THIS TIME. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1151 PM CDT MON OCT 28 2013 WITH MARGINAL TEMPERATURES...THERE IS CONSIDERABLE UNCERTAINTY OVER WHETHER PRECIPITATION WILL BE FROZEN...FREEZING OR LIQUID IN A LARGE PART OF NORTH CENTRAL AND NORTHWEST NEBRASKA. OTHERWISE...CEILINGS IN WESTERN NEBRASKA ARE 500-1000 FEET AGL WITH A FEW BELOW 500 FEET. ALSO...AREAS OF DRIZZLE OR LIGHT RAIN WILL CONTINUE THROUGH THE NIGHT. IN NORTHERN NEBRASKA...WHICH INCLUDES ANW...VTN...TIF AND MHN...FREEZING DRIZZLE OR LIGHT FREEZING RAIN IS LIKELY. IN THE FAR NORTH...THAT IS VTN AND ANW...FREEZING RAIN/DRIZZLE MAY MIX WITH OR CHANGE OVER BRIEFLY TO SNOW. AFTER 16Z WHEN TEMPERATURES RISE ABOVE 32F...IT IS ALL EXPECTED TO BE LIQUID. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON CDT /11 AM MDT/ TODAY FOR NEZ004-005-094. && $$ SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
328 AM CDT TUE OCT 29 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 329 AM CDT TUE OCT 29 2013 FOCUS OF THE SHORT TERM INCLUDES ANTICIPATED DIMINISHING SNOWFALL THIS MORNING...THEN PRECIPITATION CHANCES AND PRECIP TYPE THIS AFTERNOON AND TONIGHT. AT 3 AM CDT...THE UPPER LEVEL LOW REMAINED OVER THE ROCKIES NEAR NEVADA/IDAHO WITH SOUTHWEST FLOW ALOFT ACROSS THE EASTERN ROCKIES...THE FRONT RANGE...AND INTO THE DAKOTAS. AT THE SURFACE...COLD HIGH PRESSURE WAS CENTERED AT THE BORDER OF MANITOBA/NORTH DAKOTA/MINNESOTA...WITH LOW PRESSURE OVER COLORADO/WYOMING. THIS WAS RESULTING IN MAINLY CLEAR SKIES OVER THE NORTHEASTERN HALF OF NORTH DAKOTA...AND CLOUDS OVER THE SOUTHWEST HALF. LIGHT SNOW FROM ISENTROPIC LIFT/OVERRUNNING PRECIPITATION FROM EASTERN MONTANA ACROSS WESTERN AND SOUTH CENTRAL NORTH DAKOTA INTO NORTHERN SOUTH DAKOTA APPEARED TO BE DECREASING IN INTENSITY AND COVERAGE OVER THE PAST COUPLE OF HOURS...EXCEPT FOR AN ENHANCED AREA OF LIGHT SNOW OVER NORTH CENTRAL/NORTHEASTERN SOUTH DAKOTA THAT WAS MOVING NORTHEASTWARD INTO THE JAMES RIVER VALLEY. THE HRRR 3KM REFLECTIVITY HAS A GOOD HANDLE ON CURRENT RADAR RETURNS AND WILL FOLLOW THIS TREND IN THAT MODEL FOR THE MORNING HOURS. THE HRRR DIMINISHES THE SNOWFALL OVER WESTERN NORTH DAKOTA TO NOTHING AFTER DAYBREAK/12Z. THE MODEL INDICATES SOME CHANCES OF PRECIPITATION IN PORTIONS OF SOUTH CENTRAL/SOUTHEASTERN NORTH DAKOTA DURING THE MORNING HOURS. FEEL CONFIDENT THAT BY 6 AM MDT THE ADVISORY SHOULD BE ALLOWED TO EXPIRE. WILL KEEP SMALL CHANCES OF PRECIPITATION ACROSS THE FAR SOUTHERN TIER OF COUNTIES THIS MORNING. FOR THIS AFTERNOON...THE MODELS DEPICT THE UPPER LOW MOVING NORTHEAST TO WYOMING AND CONTINUED UPPER LEVEL ENERGY IMPULSES MOVING NORTHEASTWARD TOWARDS NORTH DAKOTA. THUS THE MODELS WERE KEEPING PRECIPITATION VERY CLOSE TO THE ND BORDER IN SOUTH DAKOTA...AND WILL KEEP SMALL CHANCE MENTIONS OF LIGHT SNOW OR LIGHT RAIN. HIGH TEMPERATURES EXPECTED TO REACH ONLY INTO THE 30S...BUT WITH WARM ADVECTION ALOFT BRINGING A CHANCE OF RAIN/SNOW TO THE FAR SOUTH. FOR TONIGHT...THE UPPER LOW REMAINS OVER WYOMING WITH CONTINUED ENERGY IMPULSES MOVING NORTHWARD ACROSS THE DAKOTAS. WARM ADVECTION ALOFT CONTINUES WITH SURFACE TEMPERATURES DROPPING BACK INTO THE UPPER 20S. TEMPERATURE PROFILES FROM BUFKIT SOUNDINGS STILL SUPPORT FREEZING RAIN. THUS WILL CONTINUE THE CHANCES OF FREEZING RAIN ACROSS THE SOUTHERN TIER OF COUNTIES AS HAS BEEN ANTICIPATED FOR THE PAST FEW DAYS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 329 AM CDT TUE OCT 29 2013 MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE PRECIPITATION CHANCES AND TYPE WEDNESDAY AND WEDNESDAY NIGHT AS AN UPPER LEVEL LOW MOVES THROUGH THE LOCAL AREA. MODELS ARE IN REASONABLE AGREEMENT AND UTILIZED A MODEL BLEND WITH PERSISTENCE FOR FORECAST ELEMENTS. THE UPPER LEVEL LOW TRACKING ACROSS THE NORTHERN ROCKIES MOVES INTO THE NORTHERN PLAINS WEDNESDAY. THE MAIN SURFACE LOW REMAINS OVER THE CENTRAL PLAINS BUT WARM ADVECTION LIFTS FROM THE PLAINS INTO THE CENTRAL AND EASTERN DAKOTAS ON WEDNESDAY WITH THE GFS/EC AND GLOBAL GEM ALL PRODUCING QPF OVER OUR FAR SOUTH CENTRAL AND SOUTHEAST CWA. WITH SURFACE TEMPERATURES HOVERING AROUND FREEZING AND MAX TEMPERATURES ALOFT GENERALLY 2-4 DEGREES CELSIUS...THERE WILL BE A THREAT OF FREEZING RAIN ALONG THE SOUTH DAKOTA BORDER WEDNESDAY MORNING. AS TEMPERATURES RISE INTO THE UPPER 30S TO LOWER 40S WEDNESDAY AFTERNOON THE PRECIPITATION IS EXPECTED TO BE ALL RAIN. BY WEDNESDAY EVENING THE UPPER LOW MOVES EAST AND COLDER AIR FILTERS INTO THE REGION. BY THIS TIME ANY LINGERING PRECIPITATION IS EXPECTED TO BE MAINLY OVER THE JAMES RIVER VALLEY...AND AS TEMPERATURES COOL DURING THE EVENING WE COULD AGAIN SEE A MIXED BAG OF LIGHT RAIN/FREEZING RAIN OR SNOW BEFORE THE PRECIPITATION ENDS. WILL NEED TO MONITOR FOR POSSIBLE FREEZING RAIN HIGHLIGHTS FAR SOUTH CENTRAL AND SOUTHEAST...BUT AT THIS TIME THE GREATEST POTENTIAL FOR ACCUMULATING PRECIPITATION APPEARS TO BE WEDNESDAY AFTERNOON WHEN TEMPERATURES WILL BE WARM ENOUGH THAT RAIN WILL BE THE PREDOMINANT PRECIPITATION TYPE. NORTHWEST FLOW DEVELOPS THURSDAY INTO FRIDAY. EMBEDDED IMPULSES IN A STRONG NORTHWEST UPPER FLOW COULD BRING A RAIN OR SNOW SHOWER TO THE NORTH AND EAST ON FRIDAY...WITH BREEZY NORTHWEST WINDS EXPECTED ACROSS THE AREA. HIGH TEMPERATURES SHOULD REMAIN IN THE 40S. THE NEXT SYSTEM COMING OFF THE PACIFIC LIFTS INTO SOUTHERN CANADA OVER THE WEEKEND. THIS WILL INDUCE A SOUTHEAST FLOW ACROSS THE AREA LATE SATURDAY THROUGH SUNDAY WITH HIGH TEMPERATURES MAINLY IN THE MID TO UPPER 40S AND POSSIBLY SOME 50S IN THE WEST. A COLD FRONT MOVES THROUGH ON MONDAY BRINGING US BACK DOWN INTO THE UPPER 30S AND 40S. HAVE STUCK WITH PERSISTENCE AND KEPT A SLIGHT CHANCE OF PRECIPITATION ACROSS THE NORTH ON SUNDAY AND MONDAY. ALTHOUGH LATEST GUIDANCE IS SUGGESTING THAT THE LOW OVER SOUTHERN CANADA MAY BE FAR ENOUGH NORTH THAT WE WILL REMAIN IN THE DRY SECTOR...ESPECIALLY ON SUNDAY...WITH MAYBE A FEW COLD ADVECTION RAIN OR SNOW SHOWERS ON MONDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1245 AM CDT TUE OCT 29 2013 HAZARDS TO AVIATION TONIGHT WILL BE MVFR TO IFR CONDITIONS IN SNOW ACROSS SOUTHWEST NORTH DAKOTA. AT 1230 AM CDT...A LARGE SURFACE HIGH PRESSURE WAS CENTERED OVER THE BORDERS OF MANITOBA/NORTH DAKOTA/MINNESOTA...WITH LOW PRESSURE OVER COLORADO/WYOMING. THESE 2 FEATURES ARE FORECAST TO MOVE EAST TONIGHT. THIS WILL SPREAD SNOW ACROSS THE SOUTHERN HALF OF THE STATE...CONTINUING TO IMPACT KDIK WITH IFR CONDITIONS TONIGHT. MVFR VSBY AT KDIK SHOULD IMPROVE TO 5SM BY 09Z AND THOUGH SNOW SHOULD BE ENDING EXPECT FOG WITH MVFR VSBY UNTIL AROUND 18Z. MVFR IS FORECAST TO CONTINUE IN KISN...DEVELOP AT KBIS AROUND/AFTER 08Z AND AT KJMS AFT 09Z. OTHERWISE VFR AT KMOT. BECOMING VFR ALL TAF SITES BY 18Z. LATER TUESDAY EVENING A LARGE AREA OF LOW/MID CLOUDINESS SHOULD MOVE NORTHWARD BRINGING MVFR CIGS TO SOUTHERN TAF SITES OF KDIK/KBIS/KJMS AFT 02Z. && .BIS WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 AM MDT EARLY THIS MORNING FOR NDZ031>033-040-041-043-044. && $$ SHORT TERM...JV LONG TERM...TWH AVIATION...JV
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1130 PM CDT MON OCT 28 2013 .UPDATE... ISSUED AT 1130 PM CDT MON OCT 28 2013 HIGH PRESSURE AND ASSOCIATED DRY AIRMASS WILL KEEP THE SHIELD UP ACROSS THE REGION. THE 00Z NAM AND RAP INDICATE QPF ACROSS THE FAR SOUTHERN FA...WHILE THE 00Z GFS KEEPS ALL MEASURABLE PRECIP SOUTH OF THE FA. CONSIDERING THE SYNOPTIC SET-UP THE GFS MAKES MORE SENSE...BUT A FEW SNOWFLAKES STILL POSSIBLE AND WILL KEEP THE CHANCE POPS IN THE FORECAST. THE THICKER CIRRUS SHIELD NOW OVER THE REGION AND TEMPERATURES HAVE BEEN STEADY THE PAST HOUR OR TWO. FORECAST IS ON TRACK. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 305 PM CDT MON OCT 28 2013 FORECAST CHALLENGE WILL BE CLOUD TRENDS AND TEMPS TONIGHT AND ALSO PCPN WITH THE NEXT SYSTEM MAINLY TUE INTO WED. MODELS REMAIN IN DECENT AGREEMENT SO WILL CONTINUE TO UTILIZE A BLEND. AS OF LATE THIS AFTERNOON CLOUDS WERE THINNING PRETTY EXTENSIVELY. THEREFORE WILL START THE EVENING WITH JUST A BIT OF CLOUD COVER OVER THE FA AND EXPECT IT TO INCREASE FROM WEST TO EAST OVERNIGHT. LOOKING AT WIND SPEEDS BECOMING PRETTY LIGHT OR LIGHT EAST NORTHEAST SO IF ANY AREAS STAY CLEAR TEMPS COULD DROP OFF ONCE AGAIN. WILL KEEP COOLEST TEMPS IN THE NORTH AND NORTHEAST. AS FOR PCPN CHANCES THEY SHOULD HOLD OFF UNTIL AFTER MIDNIGHT AT LEAST. HAVE DISCOUNTED THE WETTEST NAM SOLUTION WHICH SHOWS A BAND OF A QUARTER INCH MOVING ALONG THE INTERSTATE 94 CORRIDOR. ECMWF/GEM SOLUTIONS LOOK MUCH MORE BELIEVABLE WITH THE DRY NORTHEAST SFC FLOW AND THEY HAVE LITTLE IF ANYTHING FALLING AFTER MIDNIGHT. PREVIOUS WWD MAPS HAD INDICATED A POTENTIAL FOR SOME FREEZING DRIZZLE BUT LATEST DAY1 HAS SHIFTED IT FURTHER SOUTH AND THIS LOOKS GOOD. PCPN CHANCES ON TUE ARE ALSO LOOKING PRETTY MEAGER AND WILL CONTINUE TO DISCOUNT THE NAM. OTHER MODELS SHOW ONLY MINIMAL CHANCES ACROSS THE VERY FAR SOUTH. SHOULD HAVE A LOT MORE CLOUD COVER ACROSS THE SOUTH WITH LITTLE ACROSS THE NORTH. ABOVE MENTIONED TRENDS CONTINUE INTO TUE NIGHT AS WELL SO MOST OF THE FA SHOULD STAY PCPN FREE DURING THIS TIME FRAME. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 305 PM CDT MON OCT 28 2013 THE WESTERN CUTOFF LOW WILL BEGIN TO MOVE INTO THE NORTHERN PLAINS WED INTO THU. PCPN CHANCES WILL FINALLY INCREASE AND MAINLY ACROSS THE SOUTH AND SOUTHEAST. MODELS HAVE BEEN WAFFLING ON THE DEGREE OF WRAPAROUND PCPN WHICH WOULD MAINLY AFFECT EASTERN ND. SOME RUNS HAVE BEEN DRY AND SOME WETTER BUT REGARDLESS THIS WOULD BE THE AREA FURTHEST AWAY FROM THE MAIN RAIN BAND. CURRENT EVENT FORECAST WOULD GIVE A HALF AN INCH OF RAIN OR SO FROM WAHPETON/BRECKENRIDGE UP TOWARD BEMIDJI. VERY LITTLE TO NOTHING EXPECTED FROM COOPERSTOWN TO GRAND FORKS TO ROSEAU. WILL MAINTAIN LINGERING LIGHT PRECIPITATION CHANCES FRIDAY OVER NORTHERN MINNESOTA MAINLY EAST OF A ROX-FSE-PKD LINE AS WRAPAROUND MOISTURE LINGERS. TEMP PROFILES SUGGEST MOSTLY LIGHT RAIN...IF ANY PRECIP FALLS. WEAK HIGH PRESSURE BUILDS IN ON SATURDAY THEN MODELS DIFFER WITH NEXT PACIFIC SYSTEM FOR SUN-MON. GFS REMAINS FARTHER SOUTH WITH SFC LOW AND PRECIP MORE ALONG THE INTERNATIONAL BORDER WHILE 12Z GEM/ECMWF AREA TAD FARTHER NORTH WITH 12Z ECMWF THE FARTHEST NORTH WITH SFC LOW TRACKING NORTH OF REGINA-WINNIPEG. WILL MAINTAIN A LOW POP RIGHT ALONG THE BORDER FOR MIXED RA/SN. OVERALL TEMPS WILL REBOUND TO NEAR NORMAL LEVELS WITH MOSTLY 40S FOR HIGHS THU-SUN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1130 PM CDT MON OCT 28 2013 A VERY DRY AIRMASS WILL REMAIN ACROSS THE REGION THROUGH THE PERIOD. CIRRUS WILL BE OVERHEAD THROUGH THE NIGHT INTO THE DAY ON TUESDAY. THERE COULD BE SOME MID-LEVEL CLOUDS CLOSER THE NORTH DAKOTA/SOUTH DAKOTA BORDER...BUT STILL VFR. LIGHT AND VARIABLE WINDS TONIGHT WILL TURN SOUTHEAST ON TUESDAY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...TG SHORT TERM...GODON LONG TERM...GODON/RIDDLE AVIATION...TG
AREA FORECAST DISCUSSION
NWS TULSA OK
1134 PM CDT MON OCT 28 2013 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. SCATTERED SHOWERS AND THUNDERSTORMS WILL WILL PLAGUE NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS LATE INTO TUESDAY MORNING. THIS WILL CREATE MVFR TO OCCASIONAL IFR CONDITIONS AT THE TAF SITES ACROSS THIS AREA. CONDITIONS LOOKS TO IMPROVE BY TUESDAY AFTERNOON. && .PREV DISCUSSION... /ISSUED 952 PM CDT MON OCT 28 2013/ DISCUSSION... A FEW SHOWERS ARE BEGINNING TO DEVELOP ACROSS PARTS OF NORTHEAST OKLAHOMA AT THIS TIME. THIS ACTIVITY IS EXPECTED TO CONTINUE TO DEVELOP AND INCREASE IN BOTH COVERAGE AND INTENSITY OVERNIGHT PER THE LATEST HRRR MODEL DATA. THE MOST WIDESPREAD SHOWERS AND STORMS OVERNIGHT WILL LIKELY REMAIN NORTH OF INTERSTATE 44 AND THE BEST CHANCE FOR ANY ISOLATED SEVERE STORMS WILL BE TO THE NORTH OF THE OKLAHOMA/KANSAS BORDER. HAVE LOWERED POPS SLIGHTLY OVERNIGHT IN MOST PLACES BASED ON THE LATEST HRRR AND NAM MODEL RUNS. THE REST OF THE FORECAST LOOKS GOOD AT THIS TIME. UPDATE ON THE WAY. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...10
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
432 AM CDT TUE OCT 29 2013 .SHORT TERM (TODAY THROUGH WEDNESDAY)...DEEP SOUTHERLY FLOW THROUGH THE LOWER PARTS OF THE ATMOSPHERE WILL BRING MOISTURE BACK INTO SOUTH TEXAS DURING THE SHORT TERM. STRATUS HAS DEVELOPED ACROSS MUCH OF SOUTH TEXAS OVERNIGHT BUT ANTICIPATE THE LOW CLOUDS TO MIX OUT LATER THIS MORNING. LATEST RUN HRRR PICKING UP ON SOME SHOWER ACTIVITY THROUGH THE MORNING AND HAVE INCLUDED A 10 POP WITH MENTION OF SHOWERS THROUGH 18Z. UPPER LOW OVER THE WESTERN CONUS WILL SLOWLY MOVE TO THE EAST TODAY...INTO FOUR CORNERS REGION ON WEDNESDAY. PRESSURE GRADIENT WILL STRENGTHEN OVER SOUTH TEXAS TODAY WITH SOUTHEASTERLY WINDS INCREASING BY THE AFTERNOON. SOME GUSTS AROUND 30 MPH WILL BE POSSIBLE ACROSS THE COASTAL BEND AND OVER THE RIO GRANDE PLAINS. HIGH TEMPS TODAY WILL AGAIN BE ABOVE NORMAL WITH UPPER 80S ACROSS EASTERN SECTIONS TO LOWER 90S OUT WEST. ON WEDNESDAY...DEEPER MOISTURE WILL GET DRAWN INTO SOUTH TEXAS AS LOW LEVEL FLOW REMAINS OUT OF THE SE AND SSE. PW VALUES WILL CLIMB TO NEAR 2 INCHES (2.1 INCHES IF THE GFS VERIFIES) AS DISTURBANCE SCOOTS TO THE NORTH OF THE AREA. HIGHEST CHANCES FOR SHOWERS AND STORMS ON WEDNESDAY WILL EXIST ACROSS THE NORTHEAST ZONES WHERE CAPPING WILL BE THE WEAKEST. POPS RANGE FROM SLIGHT CHANCE OVER THE SOUTHWEST ZONES TO LIKELY IN THE NORTHEAST SECTIONS. TEMPS ON WEDNESDAY WILL BE SIMILAR TO TODAY...EXCEPT OVER THE NORTHEAST WHERE BETTER RAIN CHANCES AND CLOUD COVER MAY KEEP TEMPS DOWN A FEW DEGREES. YET ANOTHER BREEZY TO WINDY DAY ON WEDNESDAY IN ADVANCE OF THURSDAY/S FROPA. && .MARINE/COASTAL...ONSHORE FLOW BEGIN TO INCREASE ACROSS THE GULF WATERS TODAY AS GRADIENT STRENGTHENS OVER THE AREA. SMALL CRAFT ADVISORY CONDITIONS WILL DEVELOP THIS EVENING WITH WINDS OF 20 TO 25 KNOTS. IN ADDITION...SEAS WILL CLIMB TO 7 TO 8 FEET OVER THE WATERS. THESE CONDITIONS WILL LIKELY CONTINUE INTO WEDNESDAY IN ADVANCE OF A COLD FRONT. THE SOUTHERN BAYS MAY FLIRT WITH SMALL CRAFT ADVISORY CONDITIONS TODAY BUT CONFIDENCE IS NOT HIGH ENOUGH TO ISSUE AN SCA AT THIS TIME. REGARDING THE RIP CURRENT RISK... SWELLS APPEAR TO BE FINALLY LOWERING A BIT...BUT THE STRONG ONSHORE FLOW THAT IS EXPECTED WARRANT CONTINUING THE RIP CURRENT STATEMENT FOR NOW. IF CONDITIONS IMPROVE...THEN LATER SHIFTS MAY CANCEL EARLY. && .LONG-TERM (WEDNESDAY NIGHT THROUGH MONDAY)...MODELS CONTINUE TO BE IN AGREEMENT WITH BRINGING A COLD FRONT THROUGH S TX ON THU...WITH SUBTLE DIFFERENCES IN TIMING AND STRENGTH. WED NIGHT AHD OF THE FRONT...MODELS PROG PWATS OF AROUND 2 INCHES ACROSS S TX. THIS DEEP MOISTURE IS PROGD TO COMBINE WITH AN UPPER LEVEL SHORT WAVE TO PRODUCE SCT TO NUM SHRA/TSRAS ACROSS THE NRN PORTIONS OF THE CWA. THE CAPPING INVERSION WILL BE TOO STRONG ACROSS THE SRN CWA WED NIGHT...HOWEVER AM STILL EXPECTING ISOLD PRECIP DUE TO ABUNDANT MOISTURE ABV THE INVERSION. THE COLD FRONT IS PROGD TO BE PUSHING ACROSS THE NRN CWA BTWN 15-18Z THU. THE VCT CROSSROADS HAS THE HIGHEST POPS DUE TO LITTLE TO NO CAP...HIGHEST CAPE AND PROXIMITY TO THE RRQ OF THE UPPER LEVEL JET. IN ADDITION...MODELS SHOW STRONGEST LOW LEVEL CONVERGENCE ACROSS THE NE CWA. STRONGEST DYNAMICS LOOK TO BE NE OF THE CWA (ACROSS EAST TX AND LA AND EXTENDING NE) WHERE THE STORMS PREDICTION CENTER HAS PLACED A SLIGHT RISK FOR DAY 3. THE NE CWA COULD BE ON THE TAIL END OF THE STRONGER STORMS WITH THE POSSIBILITY OF ISOLD SVR. GIVEN THE ABUNDANT DEEP MOISTURE AND FORCING ALONG THE FRONT...HVY RAIN IS ALSO EXPECTED ACROSS THE NE CWA...HOWEVER THE FRONT IS PROGD TO MOVE FAIRLY QUICKLY RESULTING IN TOTAL RAINFALL AMOUNTS LESS THAN 2 INCHES FOR THE EVENT. ISOLD AMOUNTS COULD BE 2-2.5 INCHES. MAIN CONCERN WOULD BE IF THE FRONT SLOWS OR STALLS SOMEWHERE BETWEEN VCT TO CRP...THEN RAINFALL AMOUNTS COULD BE MUCH HIGHER INTO THU EVENING DURING HALLOWEEN FESTIVITIES. TSRA CHCS ARE LOWER TO THE W DUE TO STRONGER CAP AND WEAKER OVERALL DYNAMICS...BUT STILL SHOULD BE SCT WITH RAINFALL AMOUNTS TOTALING 0.5-1 INCH. AS THE FRONT MOVES SE...SO WILL THE CONVECTION BUT THE HIGHEST POPS ARE EXPECTED TO SHIFT OFFSHORE BY THU EVENING...IF THE FRONT DOES NOT SLOW DOWN. RAIN CHANCES DIMINISH FROM NW TO SE THROUGH THU NIGHT WITH RESIDUAL ELEVATED -SHRAS BRIEFLY BEHIND THE FRONT. DRIER AND SLIGHTLY COOLER CONDITIONS WILL FILTER INTO S TX ON FRI WITH REINFORCING HIGH PRESSURE MVG INTO THE AREA FRI NIGHT. THIS WILL LEAD TO CLRG SKIES AND MILD MORE SEASONABLE TEMPS THROUGH THE WEEKEND. RAIN CHCS BEGIN TO INCREASE ONCE AGAIN BY NEXT MONDAY WITH RETURN FLOW. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 87 75 87 76 86 / 10 20 30 30 50 VICTORIA 87 73 84 72 82 / 10 20 70 60 70 LAREDO 92 76 93 77 90 / 10 10 20 20 40 ALICE 89 73 89 74 87 / 10 20 30 30 40 ROCKPORT 86 76 84 76 85 / 10 20 40 40 70 COTULLA 90 74 88 72 85 / 10 10 30 40 40 KINGSVILLE 89 75 90 76 87 / 10 20 30 30 40 NAVY CORPUS 85 77 86 78 84 / 10 20 30 30 40 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...RIP CURRENT RISK THROUGH LATE TONIGHT FOR THE FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES. GM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT WEDNESDAY 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...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. && $$ TB/78...SHORT TERM TE/81...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1132 PM CDT MON OCT 28 2013 .DISCUSSION... SEE AVIATION FOR THE 06Z TAF DISCUSSION. && .AVIATION... AT 04Z MVFR CIGS WERE DEVELOPING ACROSS SOUTH CENTRAL TEXAS...HAVING REACHED KSAT AND KSSF. MVFR CIGS WILL REACH KAUS BY 07Z AND KDRT BY 08Z. CONDITIONS WILL DETERIORATE TO IFR BETWEEN 10Z AND 11Z. CIGS WILL GRADUALLY IMPROVE TO MVFR BY 17Z...VFR BY 19Z. THE PREVAILING S TO SE FLOW OFF THE GULF WILL ALLOW MVFR CIGS TO RETURN BY 30/04Z. SFC WINDS OVERNIGHT SE AT 5 TO 8 KTS...10 TO 15 KTS TUESDAY AFTERNOON. WILL NOT MENTION CONVECTION IN THE TAFS ATTM FOR TUESDAY AFTERNOON AND EVENING DUE TO UNCERTAINTY IN TIMING. && .PREV DISCUSSION... /ISSUED 628 PM CDT MON OCT 28 2013/ DISCUSSION... SEE AVIATION FOR THE 00Z TAF DISCUSSION. AVIATION... A MODERATE S TO SE FLOW IN THE BOUNDARY LAYER WILL RESULT IN THE EARLY ONSET OF MVFR CIGS THIS EVENING. THIS WILL INHIBIT SIGNIFICANT FOG FORMATION...WITH PATCHY VSBYS REMAINING AOA 1 MILE IN AREAS THAT EXPERIENCE DELAYED LOW CLOUD DEVELOPMENT. THERE ARE SOME TIMING DIFFERENCES BETWEEN THE 12Z HIRES-ARW AND THE 21Z RUC13 IN REGARDS TO THE FORMATION OF MVFR CIGS TONIGHT. WILL LEAN TOWARDS A BLEND OF THE SLOWER RUC13 AND LATEST LAMP MOS GUIDANCE. I-35 TERMINALS...MVFR CIGS WILL FORM BETWEEN 04Z AND 06Z...LOWERING TO IFR BY 11Z. CIGS IMPROVE TO MVFR BY 15Z...VFR BY 17Z. SFC WINDS OVERNIGHT SE AT 5 TO 8 KTS...SE 10 TO 15 KTS TUESDAY AFTERNOON. KDRT TERMINAL...MVFR CIGS FORM AROUND 07Z LOWERING TO IFR BY 10Z. CIGS IMPROVE TO MVFR BY 16Z...VFR BY 20Z. SFC WINDS OVERNIGHT SE AT 5 TO 10 KTS...AROUND 15 KTS TUESDAY AFTERNOON. PREV DISCUSSION... /ISSUED 323 PM CDT MON OCT 28 2013/ SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)... WARM SOUTHERLY FLOW IN THE BOUNDARY LAYER AND PACIFIC MOISTURE STREAMING INTO THE AREA IN THE UPPER LEVELS WILL RESULT IN ANOTHER HUMID AND CLOUDY NIGHT. SFC PRESSURE GRADIENTS APPEAR TO REMAIN TOO TIGHT TO PROMOTE WIDESPREAD DEVELOPMENT OF FOG...BUT COULD SEE PATCHY FOG DEVELOP IN THE NEAR-SUNRISE HOURS ACROSS EASTERN PORTIONS OF THE REGION. AN UPPER LEVEL LOW ACROSS THE WESTERN U.S. WILL PUSH EASTWARD TOWARD THE ROCKIES ON TUESDAY. THIS WILL ENHANCE THE SOUTHEASTERLY FLOW ACROSS OUR AREA AND RESULT IN ANOTHER PARTLY TO MOSTLY CLOUDY AND UNSEASONABLY WARM AFTERNOON. DEEPENING MOISTURE THROUGH THE LOWER LEVELS AND INCREASING INSTABILITY AS THE UPPER LOW APPROACHES WILL LEAD TO ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE HILL COUNTRY TUESDAY AFTERNOON. AN INCREASE IN AREAL COVERAGE IS EXPECTED TUESDAY NIGHT. OTHERWISE...THE CLOUDY MUGGY AND MILD PATTERN WILL PERSIST TUESDAY NIGHT WITH LOWS REMAINING MOSTLY NEAR 70. LONG TERM (WEDNESDAY THROUGH MONDAY)... AS THE UPPER LOW CONTINUES TO PUSH EASTWARD INTO THE CENTRAL PLAINS...IT WILL TRANSITION TO AN OPEN WAVE/TROUGH. A COLD FRONT WILL DEVELOP WITH THIS SYSTEM AND DIG INTO TEXAS ON THURSDAY. AHEAD OF THE PASSAGE OF THE FRONT...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE DRAMATICALLY ON WEDNESDAY AND WEDNESDAY NIGHT BEFORE TAPERING OFF THURSDAY AFTERNOON WITH THE FROPA. MODELS ARE PROJECTING PW VALUES TO SURGE TO ABOVE 2 INCHES ACROSS EASTERN PORTIONS OF THE REGION BY WEDNESDAY (NORMAL PWS FOR LATE OCTOBER ARE GENERALLY 1.25 TO 1.5 INCHES). GIVEN OUR POSITION IN THE WARM SECTOR AHEAD OF THE FRONT AND THE AMPLE MOISTURE...THERE IS A THREAT FOR LOCALLY HEAVY RAINFALL WITH THESE STORMS. RAINFALL TOTALS ARE EXPECTED TO AVERAGE ONE TO THREE INCHES...WITH ISOLATED TOTALS OF 5 INCHES OR MORE POSSIBLE. A FLASH FLOOD WATCH MAY BE NECESSARY. THE COLD FRONT WILL REACH THE COAST LATE THURSDAY AFTERNOON AND DRIER AIR WILL BEGIN TO FILTER INTO THE REGION THURSDAY NIGHT. THURSDAY EVENING WILL BE MILD WITH A LIGHT NORTHERLY WIND. TEMPERATURES WILL FALL TO THE UPPER 60S ACROSS MUCH OF THE REGION (LOW 60S HILL COUNTRY) BY 9 PM. THE DRIER AIR ENTERING THE REGION WILL BEGIN TO CLEAR OUT SKIES FROM NORTH TO SOUTH THURSDAY NIGHT. LOW TEMPERATURES FRIDAY MORNING WILL RANGE FROM THE MID 40S ACROSS THE HILL COUNTRY TO NEAR 60 ACROSS OUR SOUTHERN COUNTIES. UPPER LEVEL FLOW WILL BE NORTHWESTERLY ON FRIDAY AND FLATTEN-OUT OVER THE WEEKEND. THIS WILL KEEP A DRY AIRMASS OVER OUR AREA AND RESULT IN CHILLY MORNINGS AND WARM AFTERNOONS. SOUTHEASTERLY WINDS WILL RETURN IN THE LOWER LEVELS ON SUNDAY LEADING TO A RAPID WARMING TREND OF OVERNIGHT LOWS DURING THE BEGINNING OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 70 84 70 82 71 / - 10 30 60 70 AUSTIN BERGSTROM INTL AIRPORT 67 84 70 80 71 / - 10 30 60 70 NEW BRAUNFELS MUNI AIRPORT 68 85 71 82 70 / - 10 30 50 70 BURNET MUNI AIRPORT 67 81 67 78 66 / - 10 30 70 70 DEL RIO INTL AIRPORT 70 83 71 83 65 / - 20 30 30 30 GEORGETOWN MUNI AIRPORT 67 82 68 81 68 / - 10 30 70 70 HONDO MUNI AIRPORT 72 87 73 85 70 / - 10 30 50 50 SAN MARCOS MUNI AIRPORT 67 84 70 81 70 / - 10 30 60 70 LA GRANGE - FAYETTE REGIONAL 70 87 73 83 74 / - 10 20 50 70 SAN ANTONIO INTL AIRPORT 72 86 73 83 71 / - 10 30 50 60 STINSON MUNI AIRPORT 72 88 73 85 73 / - 10 30 50 60 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...13 SYNOPTIC/GRIDS...04 Area Forecast Discussion National Weather Service Lincoln IL 956 AM CDT Tue Oct 29 2013 .DISCUSSION... ISSUED 955 AM CDT Tue Oct 29 2013 Large rain shield advancing eastward across Missouri, but the eastern edge is being chewed up by the dry air that is currently in place over Illinois. Initial radar returns will go toward moistening up the column from the top down, so it will probably be toward early afternoon before any steadier rains arrive in our forecast area, and then it will be most likely south of I-72. Have left slight chance PoP`s in across the northeast third of the CWA for now, although latest guidance from the NAM/RAP/HRRR models is indicating that any rain today will likely remain to the south, and would probably hold off until mid or late afternoon if it does manage to get that far north. Have sent some updated zones/grids to freshen up the temperature and rain trends, although no significant changes were made. Geelhart && .AVIATION... ISSUED 600 AM CDT Tue Oct 29 2013 VFR conditions into the afternoon hours, then timing of the MVFR/IFR cigs late this afternoon across the west and over the remainder of the area tonight will be the main forecast challenge. Band of showers over Missouri expected to weaken as it pushes east into a drier air mass today. None the less, we do expect some light shower activity to make it at least into the SPI and DEC in the 15z-18z time frame. Forecast soundings continue to hold with mainly VFR cigs despite the rain but feel with a persistent moistening occurring at the mid and low levels of the atmosphere over the next 12 to 18 hours...we should see deteriorating conditions with respect to cigs and vsbys...and that would be especially true for all areas tonight. Surface winds will be southeast at 10 to 15 kts today and tonight. Smith && .PREV DISCUSSION... ISSUED 254 AM CDT Tue Oct 29 2013 Main challenges with this forecast package are rain chances today through Thursday and the potential for severe weather Thursday afternoon. Current upper air pattern features the main branch of the polar jet flowing well to the north across central and eastern Canada. Further southwest, a deep closed low has become cut-off from the flow and is now meandering eastward across the Great Basin. This low will be the dominant weather-maker across central Illinois for the next several days as it slowly makes its way eastward. SHORT TERM...Today through Thursday Weak frontal boundary that dropped into the area yesterday afternoon has now become stationary just north of the Ohio River. To the north of the front, a dry E/NE flow prevails across central Illinois early this morning, with 07z/2am dewpoints mainly in the 30s. This dry airmass will inhibit the eastward spread of precip currently developing ahead of a weak short-wave trough over the Plains. The onset of precip has been gradually delayed with each model run over the past couple of days, with the 00z Oct 29 suite now keeping the KILX CWA dry until afternoon. HRRR suggests light showers may arrive in the Winchester/Jacksonville area around midday, then will spread eastward to the Indiana border toward evening. Will therefore go with a dry forecast this morning, then will focus highest POPs across the southern CWA in closer proximity to the stalled front this afternoon. Further north toward the I-74 corridor, little or no precip is expected today. Once this initial wave passes, short-wave ridging in its wake will keep rain chances low tonight. Despite lack of upper forcing, moistening airmass and presence of surface boundary support low chance POPs through the night. As Great Basin upper low begins to approach from the west, surface front will get nudged northward on Wednesday. Thanks to southerly winds south of the boundary, afternoon high temperatures will rise into the upper 60s and lower 70s. In addition, showers and thunderstorms will become more widespread during the afternoon, particularly along/west of the Illinois River. Main rain/convective event is still slated for Wednesday night into Thursday as strong cold front approaches from the west. Models are generally in good agreement with their mass fields, but still have some minor differences in QPF. As boundary nears, copious amounts of moisture will advect northward from the Gulf of Mexico, with precipitable water values nearing 1.50 on Thursday. Given ample moisture, strong upper dynamics, and presence of approaching cold front, will carry likely to categorical POPs across the board Wednesday night and Thursday. Total rainfall with this system will generally range from 1 to 1.50, with isolated higher amounts within stronger storms. Strong to potentially severe thunderstorms will be possible Thursday afternoon as the front swings through the region: however, details remain uncertain at this point. NAM/GFS forecast soundings indicate a low CAPE/high shear environment in the warm sector ahead of the front, with the greatest instability focused further southeast from the Ohio River Valley to the western Gulf Coast. Latest DAY 3 convective outlook from SPC highlights this area for potential severe, but can not rule out a few strong storms with damaging wind gusts further north across east-central and southeast Illinois, particularly given impressive 0-6km bulk shear values of 70 to 75kt. LONG TERM...Friday through Monday Cooler and drier weather will return by the end of the week, as upper trough digs across the Great Lakes. GFS/ECMWF both suggest clouds and a few showers will be possible across northeast Illinois into north-central Indiana Friday into Saturday: however, think these will remain northeast of central Illinois. High pressure building into the Midwest will be the dominant weather feature in the extended, resulting in cool highs in the 50s Friday through Monday. Next chance for rain will likely hold off until Tuesday when another system approaches from the west. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
653 AM CDT TUE OCT 29 2013 .DISCUSSION... 337 AM CDT MAIN FORECAST CONCERNS CONTINUE TO BE WITH RAIN POTENTIAL AND MILDER TEMPERATURES ASSOCIATED WITH A STRONG LOW PRESSURE SYSTEM WHICH WILL MOVE THROUGH THE UPPER MIDWEST WEDNESDAY NIGHT THROUGH THURSDAY. SHORT TERM...TODAY THROUGH THURSDAY... UPPER FLOW PATTERN THIS MORNING IS DOMINATED BY A LARGE CLOSED LOW OVER THE INTER-MOUNTAIN WEST...WITH SPLIT BUT MAINLY ZONAL FLOW DOWNSTREAM ACROSS THE EASTERN CONUS. OVERNIGHT WATER VAPOR IMAGERY DEPICTS A STRONG SHORT WAVE PROPAGATING ACROSS THE CENTRAL PLAINS AND INTO THE MID-MISSOURI VALLEY...ALONG A LOW LEVEL BAROCLINIC ZONE ASSOCIATED WITH A STATIONARY SURFACE FRONT WHICH STRETCHES WEST-EAST FROM KANSAS TO THE OHIO VALLEY. FARTHER NORTH...AN ELONGATED AREA OF SURFACE HIGH PRESSURE STRETCHED FROM NEAR LAKE WINNIPEG ACROSS THE NORTHERN GREAT LAKES TO NEW ENGLAND. THE PLAINS SHORT WAVE WILL CONTINUE TO TRACK EASTWARD ALONG THE BAROCLINIC ZONE TODAY...WITH WARM ADVECTION/ISENTROPIC UPGLIDE DEVELOPING ACROSS THE REGION. THE FOCUS FOR STRONGER FORCING AND LOW LEVEL MOISTURE RETURN WILL REMAIN ACROSS FAR SOUTHERN IA/MISSOURI AND DOWNSTATE ILLINOIS THROUGH THIS AFTERNOON HOWEVER...WITH MAINLY JUST MID/HIGH CLOUDINESS EXPECTED ACROSS THE CWA AS LOW LEVEL FLOW BACKS MORE SOUTHEAST. THIS WILL PULL IN DRIER AIR FROM UPSTREAM... AS NOTED IN LAST EVENINGS 00Z SOUNDING FROM WILMINGTON OH. SOME POTENTIAL PROBABLY EXISTS FOR A SPRINKLE OR TWO FROM OUR DEVELOPING MID-DECK LATER TODAY...THOUGH IT APPEARS THAT ORGANIZED MEASURABLE PRECIP CHANCES WILL REMAIN PRETTY LOW WITH THE SUITE OF GUIDANCE NOT PRODUCING QPF. IT DOES APPEAR THAT PRECIP CHANCES WILL INCREASE SLOWLY FROM THE SOUTH TONIGHT...AS THE ELEVATED BAROCLINIC ZONE LIFTS SLOWLY NORTH IN RESPONSE TO PERSISTENT WARM ADVECTION ON SOUTH-SOUTHWEST WINDS. OTHER THAN MOISTURE TRANSPORT/CONVERGENCE ALONG THE ELEVATED WARM FRONT ON THE NOSE OF A 20-25 KT LOW LEVEL JET TONIGHT...LITTLE IN THE WAY OF SHORT WAVE SUPPORT IS NOTED AND HEIGHTS ACTUALLY RISE A BIT WITH WEAK RIDGING DEVELOPING ALOFT. GUIDANCE DOES BRING SOME LIGHT QPF ACROSS THE SOUTHERN PORTIONS OF THE CWA OVERNIGHT...THOUGH HAVE GENERALLY LOWERED POPS SIGNIFICANTLY FROM PREVIOUS FORECAST BASED ON CURRENT GUIDANCE TRENDS. THE WESTERN TROUGH BEGINS TO OPEN UP AND MOVE EAST WEDNESDAY AND WEDNESDAY NIGHT...WITH RENEWED SURFACE LOW PRESSURE DEVELOPMENT ACROSS THE CENTRAL PLAINS. THE LOW WILL LIFT ACROSS THE MID-MISSOURI VALLEY BY WEDNESDAY EVENING AND INTO THE UPPER MISSISSIPPI VALLEY BY THURSDAY MORNING...WITH SEVERAL MODELS DEPICTING A SHORT WAVE APPROACHING THE CWA WEDNESDAY AFTERNOON/EVENING. A MUCH STRONGER 40-50 KT 850 MB JET IS INDICATED WEDNESDAY NIGHT WHICH IMPINGES ON THE WARM FRONTAL ZONE AS IT LIFTS NORTH...SUGGESTING RAPIDLY INCREASING POTENTIAL FOR RAIN AND A FEW THUNDERSTORMS BY LATE WEDNESDAY AND CONTINUING INTO THURSDAY IN THE WARM SECTOR AHEAD OF THE APPROACHING COLD FRONT. STRONG MOISTURE ADVECTION...PWATS APPROACHING 1.5 INCHES...AND SURFACE DEW POINT TEMPS IN THE UPPER 50S...SUPPORT FAIRLY HIGH POPS DURING THIS PERIOD. AS FOR TEMPERATURES...INCREASING CLOUD COVER AND EAST-SOUTHEAST LOW LEVEL WINDS ARE EXPECTED TO KEEP RISES IN CHECK DESPITE WARMING ALOFT TODAY. WARMER TEMPS...IN THE 60S...WILL SPREAD NORTH WITH THE WARM FRONT INTO THE SOUTHERN CWA WEDNESDAY AND ACROSS THE ENTIRE AREA THURSDAY. RISING TEMPS ARE LIKELY WEDNESDAY NIGHT. LONG TERM...FRIDAY-MONDAY... THE LARGE SCALE UPPER TROUGH WILL LINGER ACROSS THE REGION FRIDAY AND SATURDAY AS ADDITIONAL SHORT WAVE ENERGY DIGS IN FROM THE NORTHWEST. COOL ADVECTION AND CYCLONIC LOW LEVEL FLOW IN SURFACE TROUGHING OVER THE LAKES WILL LIKELY SUPPORT CONSIDERABLE CLOUD COVER INITIALLY...WITH THE POTENTIAL FOR SOME SPRINKLES/SHOWERS ESPECIALLY FRIDAY NIGHT AND SATURDAY WITH A SECONDARY PUSH OF COLDER AIR. SURFACE HIGH PRESSURE THEN EVENTUALLY SPREADS ACROSS THE REGION LATE SATURDAY NIGHT AND SUNDAY. LONG RANGE MODEL SOLUTIONS MOVE THE HIGH QUICKLY OFF TO THE EAST SUNDAY NIGHT...WITH ANOTHER LOW PASSING NORTHWEST OF THE FORECAST AREA MONDAY. THIS SETS UP ANOTHER PERIOD OF SOUTH FLOW AND A RETURN OF RAIN CHANCES ESPECIALLY WEST ON MONDAY. TEMPS COOL TO THE UPPER 40S/LOW 50S OVER THE WEEKEND BEFORE MODERATING MONDAY. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * LINGERING MVFR CEILINGS THRU 15Z TODAY FOR ORD ONLY. * EAST WINDS BECOMING SOUTHEAST W/ MID TEEN GUSTS BY MID/LATE MORNING. * MVFR CONDITIONS RETURN EARLY WEDNESDAY MORNING. * -SHRA MOVING NEAR THE TERMINALS TONIGHT. RODRIGUEZ //DISCUSSION...UPDATED 12Z... MVFR STRATUS PERSISTING PRIMARILY OVER ORD EARLY THIS MORNING...WITH ORD BEING IN A FAVORABLE AXIS FOR PERSISTENT DEVELOPMENT. THESE CONDITIONS WILL REMAIN OVER THE NEXT 2-3 HOURS BEFORE THESE CEILINGS LIFT NORTH OF THE TERMINALS. SHOULD ONLY AFFECT ORD...BUT COULD COME CLOSE TO DPA AS THIS LIFTS NORTHWARD. CEILINGS ARE CURRENTLY HOLDING AT 1500FT...WITH THEM NOT ANTICIPATED TO LOWER ANY FURTHER. WITH THE DEPARTURE OF THIS LOW STRATUS...ONLY MID/HIGH LEVEL CLOUD COVER EXPECTED TODAY INTO TONIGHT AS MOISTURE STREAMS OUT AHEAD OF AN APPROACHING SYSTEM TO THE WEST. SEVERAL MID LEVEL DISTURBANCES WILL MOVE ACROSS THE REGION THIS EVENING WITH THE LEADING EDGE OF THE CURRENT PRECIP SHIELD OVER THE CENTRAL PLAINS WORKING ITS WAY TOWARDS THE TERMINALS TONIGHT. ALTHOUGH OUTSIDE OF SOME SCT LIGHT SHOWERS NEAR RFD...IT DOES APPEAR AS IF BETTER FORCING WILL REMAIN TO THE SOUTH OF THE TERMINALS AND LIKEWISE PRECIP AXIS. ALTHOUGH FURTHER SATURATION IS EXPECTED OVERNIGHT INTO EARLY WEDNESDAY MORNING WITH CEILINGS LOWERING...AND MVFR CONDITIONS ONCE AGAIN RETURNING OVER THE TERMINALS. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 12Z... * HIGH CONFIDENCE WITH CEILINGS/TRENDS THIS MORNING AND TODAY...MEDIUM CONFIDENCE EARLY WEDNESDAY MORNING. * HIGH CONFIDENCE WITH WIND SPEED/DIRECTION. * LOW MEDIUM CONFIDENCE WITH -SHRA/TRENDS TONIGHT. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... WEDNESDAY NIGHT...SHRA W/ CHANCE OF TSRA. THURSDAY...SHRA W/ CHANCE OF TSRA. FRIDAY...CHANCE OF SHRA EARLY...OTHERWISE VFR. SATURDAY...CHANCE OF SHRA...OTHERWISE VFR. SUNDAY...VFR. MONDAY...SLIGHT CHANCE OF SHRA...OTHERWISE VFR. RODRIGUEZ && .MARINE... 418 AM CDT MAIN FORECAST CONCERN IS WITH A SYSTEM TO APPROACH THE GREAT LAKES REGION WEDNESDAY NIGHT INTO THURSDAY...WITH GALE FORCE GUSTS TO 35 KT POSSIBLE ACROSS THE WHOLE LAKE DURING THIS PERIOD. THE CENTER OF LARGE HIGH PRESSURE SPANNING SOUTHERN CANADA AND THE UPPER MIDWEST WILL SHIFT SOUTHEAST THROUGH THE GREAT LAKES REGION TO THE ATLANTIC COAST TODAY...WHILE A TROUGH OF LOW PRESSURE OVER THE SOUTHERN PLAINS REMAINS SITUATED. AS THIS OCCURS...EXPECT EAST WINDS TO DIMINISH TO 10 TO 15 KT WHILE TURNING TO THE SOUTHEAST TODAY AND TONIGHT. DESPITE THIS TROUGH OF LOW PRESSURE DEEPENING AS IT SLOWLY LIFTS NORTHEAST THROUGH THE CENTRAL PLAINS TONIGHT INTO WEDNESDAY...A FAIRLY RELAXED GRADIENT OVER THE LAKE WILL HELP LIGHT SOUTHEAST WINDS TO PERSIST DURING THE DAY WEDNESDAY. ALTHOUGH THIS LOW WILL CONTINUE DEEPENING AS IT LIFTS TO THE UPPER MIDWEST WEDNESDAY NIGHT AND AS THIS OCCURS...EXPECT THESE SOUTHEAST WINDS TO BECOME SOUTH AND INCREASE TO 30KT. ONCE AGAIN...ITS DURING THE WEDNESDAY NIGHT AND THURSDAY TIME FRAME WHEN GALE FORCE GUSTS ARE POSSIBLE. WILL NEED TO MONITOR THIS TIME FRAME AND IF INCREASING TRENDS OCCUR OVER THE NEXT FORECAST RUNS...POSSIBLE GALES WILL NOT BE OUT OF THE QUESTION. THIS LOW WILL MOVE EAST INTO SOUTHEAST ONTARIO AND QUEBEC THURSDAY NIGHT INTO FRIDAY BEFORE EXITING TO THE NORTHEAST FRIDAY NIGHT. EXPECT SOUTHWEST WINDS TO BECOME WEST STILL HOLDING AT 30 KT THROUGH EARLY FRIDAY...BEFORE DIMINISHING LATER THAT DAY. RODRIGUEZ && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 3 PM TUESDAY. && $$ 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 605 AM CDT Tue Oct 29 2013 .DISCUSSION... ISSUED 254 AM CDT Tue Oct 29 2013 Main challenges with this forecast package are rain chances today through Thursday and the potential for severe weather Thursday afternoon. Current upper air pattern features the main branch of the polar jet flowing well to the north across central and eastern Canada. Further southwest, a deep closed low has become cut-off from the flow and is now meandering eastward across the Great Basin. This low will be the dominant weather-maker across central Illinois for the next several days as it slowly makes its way eastward. SHORT TERM...Today through Thursday Weak frontal boundary that dropped into the area yesterday afternoon has now become stationary just north of the Ohio River. To the north of the front, a dry E/NE flow prevails across central Illinois early this morning, with 07z/2am dewpoints mainly in the 30s. This dry airmass will inhibit the eastward spread of precip currently developing ahead of a weak short-wave trough over the Plains. The onset of precip has been gradually delayed with each model run over the past couple of days, with the 00z Oct 29 suite now keeping the KILX CWA dry until afternoon. HRRR suggests light showers may arrive in the Winchester/Jacksonville area around midday, then will spread eastward to the Indiana border toward evening. Will therefore go with a dry forecast this morning, then will focus highest POPs across the southern CWA in closer proximity to the stalled front this afternoon. Further north toward the I-74 corridor, little or no precip is expected today. Once this initial wave passes, short-wave ridging in its wake will keep rain chances low tonight. Despite lack of upper forcing, moistening airmass and presence of surface boundary support low chance POPs through the night. As Great Basin upper low begins to approach from the west, surface front will get nudged northward on Wednesday. Thanks to southerly winds south of the boundary, afternoon high temperatures will rise into the upper 60s and lower 70s. In addition, showers and thunderstorms will become more widespread during the afternoon, particularly along/west of the Illinois River. Main rain/convective event is still slated for Wednesday night into Thursday as strong cold front approaches from the west. Models are generally in good agreement with their mass fields, but still have some minor differences in QPF. As boundary nears, copious amounts of moisture will advect northward from the Gulf of Mexico, with precipitable water values nearing 1.50 on Thursday. Given ample moisture, strong upper dynamics, and presence of approaching cold front, will carry likely to categorical POPs across the board Wednesday night and Thursday. Total rainfall with this system will generally range from 1 to 1.50, with isolated higher amounts within stronger storms. Strong to potentially severe thunderstorms will be possible Thursday afternoon as the front swings through the region: however, details remain uncertain at this point. NAM/GFS forecast soundings indicate a low CAPE/high shear environment in the warm sector ahead of the front, with the greatest instability focused further southeast from the Ohio River Valley to the western Gulf Coast. Latest DAY 3 convective outlook from SPC highlights this area for potential severe, but can not rule out a few strong storms with damaging wind gusts further north across east-central and southeast Illinois, particularly given impressive 0-6km bulk shear values of 70 to 75kt. LONG TERM...Friday through Monday Cooler and drier weather will return by the end of the week, as upper trough digs across the Great Lakes. GFS/ECMWF both suggest clouds and a few showers will be possible across northeast Illinois into north-central Indiana Friday into Saturday: however, think these will remain northeast of central Illinois. High pressure building into the Midwest will be the dominant weather feature in the extended, resulting in cool highs in the 50s Friday through Monday. Next chance for rain will likely hold off until Tuesday when another system approaches from the west. && .AVIATION... ISSUED 600 AM CDT Tue Oct 29 2013 VFR conditions into the afternoon hours, then timing of the MVFR/IFR cigs late this afternoon across the west and over the remainder of the area tonight will be the main forecast challenge. Band of showers over Missouri expected to weaken as it pushes east into a drier air mass today. None the less, we do expect some light shower activity to make it at least into the SPI and DEC in the 15z-18z time frame. Forecast soundings continue to hold with mainly VFR cigs despite the rain but feel with a persistent moistening occurring at the mid and low levels of the atmosphere over the next 12 to 18 hours...we should see deteriorating conditions with respect to cigs and vsbys...and that would be especially true for all areas tonight. Surface winds will be southeast at 10 to 15 kts today and tonight. Smith && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
625 AM CDT Tue Oct 29 2013 ...AVIATION UPDATE... .SHORT TERM...(Today and Tonight) Issued at 359 AM CDT TUE OCT 29 2013 08Z water vapor imagery shows a closed low over the Great Basin. At the surface, low pressure was centered over the TX panhandle where a cold front was pushing south southeast. An inverted trough stretched northeast from the area of low pressure across central KS, just west of the forecast area. Southerly flow continues to feed a relatively moist airmass into the MCS that has developed over eastern KS. For today and tonight, the thinking is that once the MCS passes to the east of the forecast area mid to late morning, that there should be a general lull in widespread precip. Much of the forcing for the MCS has been derived from the low level jet and isentropic assent feeding moisture north. Models show the low level jet veering to the southwest by mid morning which should focus the better forcing to the east across MO. Will keep a POP through the day however as low level isentropic surfaces maintain some weak lift within a saturated stable layer shown by the model forecast soundings. Because of this there could be some patchy drizzle throughout the day, although there are signs this lift weakens through the afternoon. The GFS and NA< also maintain some modest instability within the warm sector mainly south of the area. The biggest question for today is how far a weak low will propagate northeast along the inverted trough into north central KS. This has implications mainly for sky cover and temps. If it makes it into north central KS by this afternoon, the warm front could lift north along the I-70 corridor and allow for the low clouds to scatter out and temps to warm a little more. With the warmer temps, the surface based instability could move a little further north. Fortunately there does not appear to be a big shortwave within the flow to spark deep moist convection, and the forecast soundings keep a capping inversion over the warm sector. Nevertheless did not feel confident enough to just go with drizzle and maintained a mention of showers and thunderstorms through the afternoon. At this point think areas along and north of I-70 will remain overcast and cool with highs in the upper 50s along the NEB state line to the mid 60s along I-70. Have temps warming to near 70 from EMP to Abilene where the warm front is more likely to move to. Tonight timing of the next wave of precip is the main concern. Models suggest a weak wave lifting out of the based of the closed low to the west. This should cause the surface low pressure to redevelop back to the southwest near the TX/OK panhandles and cause the low level jet to back to the south again. The forecast shows POPs increasing after midnight, but it appears the forcing comes together mainly after 12Z. Lows should be mild for late October with upper 50s and low 60s due to cloud cover and continued moisture advection. Wolters .LONG TERM...(Wednesday through Monday) Issued at 359 AM CDT TUE OCT 29 2013 Main upper trough will begin to lift out of the Rockies and into the plains Wednesday and Wednesday night. Large scale ascent will be in the increase through the day as the warm front remains situated closer to the Nebraska border which is where the highest rainfall amounts are expected. As the cold front begins to make an eastward push across the CWA in the afternoon more showers and thunderstorms are expected to form along and ahead of it...however the degree of instability will remains uncertain with widespread cloud cover and precip ahead of it during much of the day. Although feel the models are overdoing the midday MLCAPE...still feel that 500-1000 J/kg are not unreasonable with plenty of shear. Therefore...could see a brief window in the late afternoon/early evening for strong to severe convection along the front as high temps slowly edge up through the upper 60s/near 70. As the front and axis of deeper moisture ahead of it slowly shift eastward across the Wednesday night...so will the higher pops...with likely chances limited to areas generally south and east of the Kansas Turnpike after midnight. As the cold front pushes southeast out of the county warning area Thursday morning...precipitation chance will go with it as much drier air in its wake as the main upper trough axis moves to the east in the afternoon. Will carry a dry forecast for Thursday afternoon as skies become mostly sunny all areas with highs in the lower 60s. Will then maintain a dry forecast Friday and through the weekend as the CWA remains in between the two troughs over the eastern and western CONUS. Although highs in the upper 50s and lower 60s will be in the rule Friday and Saturday...a return to southerly winds be Sunday and warm advection ahead of the advancing western trough should allow for highs to rebound back into the low to middle 60s on Sunday. The next chance for showers arrives Monday into Monday night with the approach of the upper trough in the Rockies. && .AVIATION...(For the 12Z TAFs through 12Z Wednesday Morning) Issued at 625 AM CDT TUE OCT 29 2013 With precip exiting to the east sooner than expected, will keep a dry forecast beginning at 12Z. There may still be some drizzle through the day, but latest OBS do not show drizzle immediately behind the precip shield. Main concern is how far north and east the warm front will lift this afternoon. The last several runs of the RAP13 have been going back and forth in bringing the boundary near the terminals. This will have a large impact on whether IFR/LIFR conditions persist or if CIGS lift to MVFR. For now stayed with persistence and maintained a IFR forecast since the NAM and now the RAP keep the warm front just south. Precip could move back into the terminals prior to 12Z Wed, but chances look better after 12Z so have not included a mention at this time. && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...Wolters LONG TERM...63 AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
725 AM EDT TUE OCT 29 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 426 AM EDT TUE OCT 29 2013 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALF OVER THE UPR GREAT LKS BTWN UPR TROF CENTERED OVER ERN HUDSON BAY AND A RDG IN THE PLAINS. SPRAWLING SFC HI PRES/DRY AIRMASS WITH PWAT AOB 0.25 INCH IS CENTERED OVER THE UPR LKS...BRINGING QUIET WX TO THE CWA. ALTHOUGH SOME HI CLDS IN THE RRQ OF A 100KT H3 JET MAX ARE STREAMING INTO THE CWA...TEMPS HAVE FALLEN SHARPLY AND INTO THE TEENS OVER INTERIOR LOCATIONS WITH LIGHT WINDS UNDER THE SFC HI. MORE SC DOES LINGER OVER THE E NEAR LK SUP WITH LLVL NW FLOW E OF THE HI CENTER...AND THESE CLDS HAVE RESTRICTED THE DIURNAL TEMP FALL IN THIS AREA. LOOKING TO THE W...DESPITE SOME DRY LLVL AIR SHOWN ON THE 00Z ABERDEEN SDAKOTA AND BISMARK RAOBS...THERE IS AN AREA OF -SN OVER SRN NDAKOTA AND NRN SDAKOTA. THE PRIMARY FORCING MECHANISMS APPEAR TO BE SOME ISENTROPIC ASCENT ON THE 295-300K SFCS AS WELL AS A BAND OF H7-75 FGEN UNDER UPR DVGC IN RRQ OF THE H3 JET MAX. AN UPSLOPE SFC E WIND ALSO APPEARS TO BE AIDING IN THE LLVL MOISTENING DESPITE THE LLVL DRY AIR FEED OUT OF THE E ON THE SRN FLANK OF THE SFC HI PRES RDG. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE PCPN CHCS OVER UPR MI RELATED TO THE UPSTREAM DISTURBANCE CAUSING SOME -SN IN THE NRN PLAINS. TODAY...AS THE UPR JET CORE SHIFTS TO THE E TODAY...EXPECT THICKENING HI/MID CLDS UNDER ACCOMPANYING UPR DVGC IN THE RRQ OF THIS FEATURE AS SFC HI PRES RDG HANGS BACK INTO THE UPR LKS. AS THE FLOW BACKS TO THE SW...ANY LK CLDS OVER THE E SHOULD SHIFT BACK INTO THE LK. MOST OF THE LARGER SCALE MODELS SHOW SOME PCPN ARRIVING NEAR THE WI BORDER AFT 18Z AS BAND OF H7-75 FGEN SHIFTS TO THE NE. HOWEVER...MOST OF THE HIER RES MODELS SHOW ONLY PATCHY QPF. BIGGEST IMPEDIMENT WL BE LINGERING LLVL DRY AIR AND ABSENCE OF ANY SGNFT UPSLOPE WIND COMPONENT THAT IS AIDING THE LLVL MOISTENING UPSTREAM. OTHER NEGATIVES INCLUDE QUICK DEPARTURE OF UPR JET CORE TO THE E AFT 18Z AND WEAKENING MID LVL ISENTROPIC ASCENT. SO OPTED TO CUT BACK ON POPS OVER THE N HALF OF THE CWA...WITH HIER POPS FOR SOME -SN/-RA NEAR THE WI BORDER...ESPECIALLY IN MNM COUNTY/SCENTRAL WITH A LGT UPSLOPE SE WIND JUST TO THE S OF SFC RDG AXIS. THICKENING CLDS SHOULD RESTRICT THE DIURNAL TEMP RECOVERY...SO TENDED TOWARD THE LOWER END OF GUIDANCE FOR MAX TEMPS. TONIGHT...SUPPORT FOR PCPN IN THE EVNG WL FADE WITH THE ARRIVAL OF LARGER SCALE QVECTOR DVGC/UPR CNVGC IN ADVANCE OF THE UPR RDG MOVING NEWD FM THE PLAINS. ENDED THIS LINGERING PCPN OVER MAINLY THE SCENTRAL BY THE EARLY MRNG HRS ON WED. DESPITE THE VIGOROUS DRYING ALF...MOST MODEL FCST SDNGS INDICATE MSTR WL LINGER IN THE LOWER LVLS...ESPECIALLY OVER THE SCENTRAL WHERE PCPN IS MOST LIKELY TO FALL TODAY. SO MAINTAINED CLDY CONDITIONS IN THIS AREA...WITH PARTIAL CLRG OVER THE NW. THE LOWEST TEMPS SHOULD OCCUR OVER THE INTERIOR NW WHERE SOME CLRG IS LIKELY. IF THE CLDS BREAK UP ELSEWHERE...MIN TEMPS MAY HAVE TO BE ADJUSTED DOWN WITH LGT WINDS UNDER LINGERING SFC RDG AXIS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 426 AM EDT TUE OCT 29 2013 MID-UPR LEVEL TROUGH SLIDES EAST ACROSS THE NATIONS MID SECTION WEDNESDAY INTO THURSDAY. INITIAL TROUGHING LIFTS ACROSS GREAT LAKES TOWARD EASTERN CANADA FRIDAY INTO SATURDAY WHILE SOUTHERN PORTION OF THE TROUGH DOES NOT EXIT EASTERN CONUS UNTIL LATER IN THE WEEKEND. AS THE LEADING TROUGH LIFTS TOWARD GREAT LAKES...SFC LOW PRESSURE TROUGH OVER THE PLAINS ON WEDNESDAY DEVELOPS INTO 1000MB SFC LOW OVER UPR GREAT LAKES BY 12Z THURSDAY...THEN DEEPENS TO 975-980MB LOW BTWN LK SUPERIOR AND JAMES BAY BY 12Z FRIDAY. AS IT HAS LOOKED FOR A WHILE...MAIN PERIOD OF PRECIP...IN THE FORM OF RAIN...OCCURS LATER WEDNESDAY NIGHT INTO THURSDAY WITH MORE SHOWERY PRECIP TAKING OVER IN WAKE OF THE LOW LATER THURSDAY NIGHT INTO FRIDAY. SOUNDINGS FOR WEDNESDAY INDICATE MOISTURE BLO H7 WITH MINIMAL LIFT. THINKING THE LOW-LEVEL MOISTURE IS OVERDONE...BUT DO EXPECT CLOUDS TO THICKEN THROUGHOUT THE DAY AS WARM AIR ADVECTION DEVELOPS OUT AHEAD OF SFC LOW IN THE PLAINS. COULD BE JUST ENOUGH WEAK LIFT AND MOISTURE ADVECTION TO FORM SOME LGT RAIN LATER IN THE WEST OVER THE WEST AND SOUTH...NOT A BIG DEAL AT ALL AS PRIMARY AREA OF RAIN WILL NOT ARRIVE UNTIL LATER WEDNESDAY NIGHT. GIVEN THE CLOUDS...MAX TEMPS ON WEDNESDAY IN THE LOW-MID 40S. TEMPS SHOULD THEN STAY STEADY OR SLOWLY RISE THROUGH WEDNESDAY NIGHT. TIMING OF PRECIP ON WEDNESDAY NIGHT A BIT SLOWER THAN MODELS SHOWED 24 HR AGO. DIVERGENCE ALOFT ON NOSE OF 250MB JET STREAK LIFTING ACROSS UPR LAKES INTERACTS WITH H85 AND H7 MOISTURE ADVECTION TO THE NORTH OF SFC-H85 LOWS. EXPECT BRIEF PERIOD OF MODERATE RAIN TO SWEEP FROM SOUTH TO NORTH ACROSS CWA. EVEN WITH RAIN MOVING THROUGH...PUT A MENTION OF FOG IN OVERNIGHT WEDNESDAY NIGHT INTO THURSDAY MORNING AS DWPNTS RISING INTO THE 40S TO LOWER 50S WILL BE RIDING OVER COLDER GROUND SFC WITH 2 INCH SOIL TEMPS WELL BLO 40 THE LAST WEEK OR SO. IF THE RAIN EXITS QUICKER...THEN THE FOG WOULD LIKELY BECOME MORE WIDESPREAD. DRY SLOT/MID-LEVEL DRYING TAPERS OFF RAIN ON THURSDAY MORNING. AS LONG AS WINDS ARE NOT TOO STRONG FOG COULD PERSIST OVER THE UPSLOPE AREAS OF CNTRL UPR MICHIGAN INTO THE MIDDLE PART OF THE DAY. WINDS SHIFT TO WEST AND START TO INCREASE IN THE AFTN AS SFC LOW CENTER MOVES TO CNTRL OR EASTERN LK SUPERIOR WHILE DEEPENING. DESPITE CLOUDS/FOG AND SPOTTY RAIN...MAX TEMPS WILL STILL PUSH WELL INTO THE 50S FROM SHEAR ADVECTION ALONE IN THE WARM SECTOR OF THE SFC LOW. ANOTHER WAVE OF RAIN COULD DEVELOP LATE AFTN/THURSDAY EVENING AS PRIMARY HEIGHT FALLS AND DEEP LAYER Q-VECTOR CONVERGENCE SWEEPS IN OVER MAINLY SOUTH AND EAST CWA. KEPT POPS HIGHEST TO THE EAST OF MQT AND ESC AS THAT IS WHERE LARGER SCALE FORCING INTERACTS WITH BETTER MOISTURE ADVECTION. BASED ON GRADIENT OF MID-LEVEL MOISTURE AND FCST H7-H5 LAPSE RATES...THINKING BETTER CHANCES OF TSRA WILL REMAIN TO THE SOUTH AND EAST OF CWA LATER THURSDAY AFTN INTO EVENING. STRONGER SHORTWAVE/DEEP MOISTURE MAY DROP ACROSS GREAT LAKES FRIDAY NIGHT INTO SATURDAY WHILE COOLER AIRMASS LINGERS AS H85 TEMPS FALL TO -4C TO -6C BY 12Z SATURDAY. NW-NNW CYCLONIC FLOW AT 1000-850MB PERSISTS THROUGH SATURDAY SUGGESTING THERE WILL LIKELY BE SOME LAKE ENHANCED PRECIP. 1000-850MB/H85-H7 THICKNESSES AND FORECAST SFC TEMPS POINT TO MAINLY SNOW FOR PTYPE FRIDAY NIGHT INTO SATURDAY MORNING OVER THE WEST WITH RAIN/SNOW MIX FARTHER EAST. DETAILS WILL NEED TO BE SORTED OUT LATER THIS WEEK...BUT DOES SEEM THAT THE FRIDAY NIGHT INTO SATURDAY MORNING PERIOD HOLDS SOME POTENTIAL FOR ACCUMULATING SNOW OVER THE HIGHER TERRAIN OF WEST AND NORTHWEST UPR MICHIGAN. TEMPS COOL FURTHER INTO SATURDAY NIGHT BUT DEEPER MOISTURE AND CYCLONIC FLOW WILL BE EASING AS SFC-H85 RIDGE NEARS FROM THE WEST. LAKE EFFECT SNOW SHOWERS COULD CONTINUE MOST OF THE NIGHT...MAINLY FOR NW FLOW AREAS TO THE EAST OF MARQUETTE. SUNDAY IS A TRANSITION DAY IN WEATHER. EASTERN CONUS TROUGH EDGES EAST AS STRONGER JET ENERGY MOVES TO FRONT SIDE OF TROUGH WHICH THEN CLEARS WAY FOR WESTERN CONUS TROUGH TO EXPAND TOWARD ROCKIES AND RIDGING TO EXPAND ACROSS THE GREAT LAKES. RIDGING LOOKS BRIEF THOUGH AS THE TROUGHING OVER THE WESTERN CONUS EXPANDS INTO THE PLAINS LEADING TO A POTENTIALLY ACTIVE SW FLOW PATTERN ACROSS THE GREAT LAKES BY EARLY NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 724 AM EDT TUE OCT 29 2013 ALTHOUGH THERE WL BE A TREND TOWARD THICKENING HI/MID CLDS WELL N OF A WARM FNT...EXPECT VFR CONDITIONS AND LGT WINDS UNDER LINGERING SFC RDG AXIS THRU AT LEAST MOST OF TODAY. AN UPR DISTURBANCE WL BRING SOME -SN TO MAINLY THE S HALF OF UPR MI LATE THIS AFTN/EVNG...AND CONDITIONS MAY DROP TO MVFR AT THE MORE SRN SAW/IWD LOCATIONS DURING THIS TIME IF THE LLVL DRY AIR IS MOISTENED SUFFICIENTLY. CMX IS LIKELY TO REMAIN VFR WITH THE PCPN REMAINING TO THE S. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 426 AM EDT TUE OCT 29 2013 LIGHT WINDS LESS THAN 20 KTS THROUGH WEDNESDAY AS HIGH PRESSURE RIDGE OVER THE AREA SLOWLY MOVES TOWARD THE EAST COAST. LOW PRESSURE DEVELOPING OVER THE PLAINS ON WEDNESDAY WILL LIFT TOWARD THE UPPER GREAT LAKES ON THURSDAY THEN DEEPEN AS IT MOVES INTO QUEBEC ON FRIDAY. SE-E WINDS 20-25 KTS WEDNESDAY NIGHT INTO THURSDAY AHEAD OF THE SYSTEM...THEN AFTER THE LOW MOVES EAST OF THE LAKE...EXPECT WINDS TO SHIFT NW 25-30 KTS THURSDAY NIGHT THROUGH SATURDAY AS COLDER AIR PLUNGES ACROSS THE UPPER LAKES REGION. WINDS DIMINISH ON SUNDAY WITH ARRIVAL OF HIGH PRESSURE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...KC MARINE...JLA
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
959 AM CDT Tue Oct 29 2013 .MESOSCALE DISCUSSION... Issued at 959 AM CDT TUE OCT 29 2013 Rainfall continues across the region this morning. There has been a decrease in lightning reports over the past hour or so, indicative of an instability starved airmass. Latest RUC forecast indicates MLCAPE at or below 500 J/kg over much of the area for the rest of today, thus it appears that our main issues for the rest of this morning into this afternoon will be a few cloud to ground lightning strikes and perhaps a storm capable of small hail (though the risk for hail is decreasing at this time). Rainfall has been heavy in spots and the radar estimations look to be in the ballpark based on observed rainfall reports this morning. Legacy precip estimations appear to most representative at this time. From a forecast perspective, concern is increasing for additional rounds of heavy rainfall and an increasing risk for flooding given observed rainfall from this morning and an increasingly moist airmass (both Pacific and Gulf connections). && .SYNOPSIS... Issued at 237 AM CDT TUE OCT 29 2013 Water vapor was showing large upper level closed system centered around Nevada with large Pacific moisture plume streaming from south of the low into the southern/central Plains into the mid Mississippi valley region. Convection developed during the mid to late evening in the Plains as pieces over shortwave energy have ejected out of the upper low along with a jet streak. In addition, a 30 to 45 kt low level jet has set up from the southern into central Plains. This convection has advanced into western Missouri early into the overnight hours, however most of the lightning strikes remain west of our CWA as instability is still lacking over the area. Joplin has picked up around .13 of an inch in the past hour. Our main focus in the short term (today and tonight) will be with convection and precipitation amounts. Several waves of precipitation will be possible through Thursday as the upper low slowly progresses eastward towards the area. && .SHORT TERM...(Today and Tonight) Issued at 237 AM CDT TUE OCT 29 2013 For today...first batch of convection (currently occurring over the western CWA) is expected to track east across the CWA. Will probably see scattered lightning strikes with this activity, but overall instability will remain low and not expecting much in the way of strong or severe storms with this first wave. Decent precipitation totals will be possible with some locations receiving between a half inch to inch. Isolated higher amounts will be possible, with the higher totals expected over the northwest half of the CWA. There will probably be a lull in activity from late in the day through much of the evening before convection redevelops over the northwestern CWA during the late evening and overnight hours. If we could get enough instability, there may be some elevated hailers with this activity, but overall severe chances look to be on the low side with the better instability remaining to the west. .LONG TERM...(Wednesday through Monday) Issued at 237 AM CDT TUE OCT 29 2013 The upper level system will begin to move into the Plains on Wednesday with strong southerly winds continuing out ahead of this system across the CWA. Best instability will remain south of the area late Wednesday into Wednesday night ahead of the approaching cold front, but convection ahead of the front during this time frame into Thursday will offer our best chance of stronger to possibly severe storms. No problem with the shear profiles with this dynamic system, but the instability still looks to be on the weaker side for any widespread severe risk. The bulk of the precipitation should move through by 18z Thu with the pre-frontal trough as drier air begins to work in from the west behind this. Total clearing should take place by Thursday evening. Widespread storm total QPF values of 1 to 3 inches are being forecast with this slower moving system as the Pacific moisture stream will be ongoing for much of the event, and eventual increase in Gulf moisture as well. For now will continue the trend of limited risk of flooding for the northwest half of the CWA which will have the higher expectant QPF. Generally quiet weather is expected after the passage of this system from Thursday night through the weekend. May start to see precipitation chances increase by early next week as another larger trough begins to push into the Plains. && .AVIATION... Pilots flying in and out of the southwest Missouri airports will need to monitor for low flight conditions this morning and again late tonight. A large cluster of showers and thunderstorms was progressing over eastern Kansas and much of Missouri this morning. Low ceilings and visibilities were observed at many locations, including Joplin, Springfield, and Branson. Additional IFR and MVFR conditions are expected this morning, prior to improving by mid day, as the rain shifts east of the region. Once the rain moves out of the Ozarks, expect mostly dry weather through the afternoon, as southerly breezes persist at around 10 mph. Additional scattered showers and thunderstorms are expected late tonight and into Wednesday morning. If a thunderstorms track over one of the airports, then low flight conditions can be expected. The intermittent stormy weather will continue into Thursday. Safe Travels. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ MESOSCALE...Gagan SYNOPSIS...Lindenberg SHORT TERM...Lindenberg LONG TERM...Lindenberg AVIATION...Cramer
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
620 AM CDT TUE OCT 29 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 338 AM CDT TUE OCT 29 2013 THE DEEP H500 MB UPPER LEVEL LOW ACROSS THE WESTERN U.S. IS EXPECTED TO LIFT SLOWLY NORTHEAST INTO WRN WY BY 12Z WEDNESDAY. THE MODELS ARE STRENGTHENING THE WARM AIR ADVECTION FROM 850 MB TO 700 MB AS THE LOW LIFTS NORTH BUT REMAIN WEST OF THE FORECAST AREA. THUS THE THREAT OF FREEZING PRECIPITATION WOULD APPEAR TO BE DECREASING SOMEWHAT. THE MODELS SHOW A STRONG DRY SLOW WORKING INTO THE FCST AREA BETWEEN 850-700MB DURING THE DAY TODAY. AS THE UPPER LEVEL COLD POOL NOSES INTO WYOMING TONIGHT...STEEPENING LAPSES MIGHT SUPPORT AN ORGANIZED ROUND OF ACCUMULATING ICE ACROSS THE PANHANDLE AND PERHAPS INTO WESTERN NEBRASKA. TEMPERATURES AT 700 MB IN THESE AREAS COOL TO -2C TO -4C WHICH WOULD NOT SUPPORT RAPID SNOW GROWTH AND GIVEN THE STRENGTHENING WARM AIR ADVECTION AT 850MB...ALL MODELS ARE ABOVE FREEZING 1C TO 4C...FREEZING RAIN WOULD APPEAR TO BE THE ONLY THREAT. NOTE THE BEST GUESS AT MIN TEMPERATURES WEDNESDAY MORNING PRODUCED LOWS NEAR 30 ACROSS THE NORTHWEST ZONES WITH A FREEZING LINE RUNNING FROM ROUGHLY BIG SPRINGS TO AINSWORTH. HIGHS TODAY RISE TO THE MID 30S ACROSS SHERIDAN AND CHERRY COUNTIES. THE RAP MODEL PRODUCED HIGHS AROUND 33 IN THAT AREA THIS AFTERNOON AND THE HRRR SHOWED 35F. WITH LOWS FALLING TO AROUND 30 TONIGHT...IT WOULD APPEAR ABOUT 8 TO 10 HOURS OF SUBFREEZING WEATHER COULD DEVELOP WHICH WOULD NECESSITATE ANOTHER WINTER WEATHER ADVISORY ACROSS SHERIDAN AND CHERRY COUNTIES. TEMPERATURES TODAY SHOULD RISE ABOVE THE FREEZING MARK AROUND NOON IN THIS AREA AND WE ARE FORECASTING WARMER LOWS TONIGHT THAN ARE OCCURRING THIS MORNING. GIVEN THE DRY AIR MOVING IN ALOFT AHEAD OF THE UPPER LOW...FOG COULD BECOME A BIT MORE WIDESPREAD TONIGHT BUT MAINLY EAST OF HIGHWAY 83 AS SUGGESTED IN THE 850-700MB MOISTURE FIELDS. DRIZZLE WOULD APPEAR TO BE THE OPERATIVE PRECIPITATION MODE WITH THE SHALLOW MOISTURE PROFILES ALONG AND EAST OF HIGHWAY 83 BUT SOME SOLNS LIKE THE GFS DEVELOP WIDESPREAD LIGHT RAIN ALONG AND EAST OF HIGHWAY 83. THE OTHER MODELS DO THE SAME BUT ARE FARTHER EAST FAVORING CENTRAL AND EASTERN NEB WITH THIS RAIN. IT LOOKS LIKES THE GFS IS MAINTAINING A STRONGLY BACK LOW LEVEL FLOW TONIGHT WHILE THE NAM FOR EXAMPLE VEERS THE 850 WINDS A BIT MORE TOWARD ERN NEB. THE 305K ISENTROPIC MOISTURE TRANSPORT VECTORS IN BOTH MODELS IS DIRECTED TOWARD EASTERN AND CNTL NEB. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 338 AM CDT TUE OCT 29 2013 STORM SYSTEM WILL CONTINUE MOVING THROUGH THE CENTRAL AND NORTHERN PLAINS DURING THE DAY WEDNESDAY...EXITING TO THE NORTHEAST WEDNESDAY NIGHT. AS THE UPPER TROUGH AXIS CROSSES THE AREA WEDNESDAY...SHOWERS WILL CONTINUE TO BE POSSIBLE. WARM AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL CONTINUE TO KEEP MOST OF THE PRECIPITATION IN LIQUID FORM. REALLY LITTLE CHANCE OF SNOW...AS ALL MODELS KEEP TEMPERATURES AT 850MB ABOVE FREEZING. AT THE SURFACE HOWEVER...SHALLOW ARCTIC AIR WILL REMAIN ACROSS THE AREA...WITH TEMPERATURES WEDNESDAY MORNING NEAR OR A FEW DEGREES BELOW FREEZING ACROSS PORTIONS OF NORTHERN AND NORTHWEST NEBRASKA. FREEZING RAIN WILL LIKELY BEGIN THE DAY...BUT WILL QUICKLY CHANGE TO RAIN AS TEMPERATURES WARM ABOVE FREEZING BY MID MORNING. FARTHER EAST ACROSS CENTRAL AND SOUTHWEST NEBRASKA...SUFFICIENT MID LEVEL INSTABILITY WARRANTS A THUNDER MENTION DURING THE MORNING. BY AFTERNOON...DRY AIR IN THE MID LEVELS SPREADS NORTHEAST...ENDING PRECIPITATION FROM SOUTHWEST TO NORTHEAST. SKIES BEGIN TO CLEAR WEDNESDAY NIGHT...WITH DOWNSLOPE FLOW AND SUNNY SKIES BOOSTING HIGHS THURSDAY INTO THE 50S TO NEAR 60. DRY AND MILD WEATHER WILL CONTINUE THROUGH THE WEEKEND...AHEAD OF THE NEXT UPPER TROUGH AND POTENTIAL PRECIPITATION EARLY NEXT WEEK. DETAILS REMAIN SKETCHY WITH THIS NEXT SYSTEM...AND WILL ONLY CARRY SLIGHT CHANCES FOR RAIN/SNOW AT THIS TIME. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 614 AM CDT TUE OCT 29 2013 WIDESPREAD IFR CONTINUES TODAY AND TONIGHT WITH UPSLOPE MOISTURE HOLDING CEILINGS LOW. A PERIOD OF MVFR IS EXPECTED LATE THIS MORNING THROUGH LATE THIS AFTERNOON ALONG AND EAST OF HIGHWAY 83. LOW CEILINGS ARE EXPECTED TONIGHT AS EASTERLY WINDS CONTINUE. AN UPPER LEVEL LOW...CURRENTLY ACROSS THE SWRN U.S....WILL LIFT NORTH INTO WYOMING. AS THIS OCCURS...ADDITIONAL SHOWERS AND ISOLATED TSTMS SHOULD REDEVELOP. FREEZING DRIZZLE OR FREEZING RAIN IS EXPECTED TO REDEVELOP TONIGHT ACROSS NORTHWEST NEBRASKA. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON CDT /11 AM MDT/ TODAY FOR NEZ004-005-094. && $$ SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1019 AM CDT TUE OCT 29 2013 .UPDATE... ISSUED AT 1017 AM CDT TUE OCT 29 2013 NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE. THE BIGGEST QUESTION WILL BE HOW MUCH STRATUS WILL BE ERODED THROUGH THE AFTERNOON. THE 14 UTC RAP HOLDS NEARLY THE ENTIRE STRATUS FIELD THIS MORNING IN PLACE...WHILE THE 12 UTC NAM SUGGESTS SOME CLEARING NORTH AS THE SURFACE RIDGE AXIS SLOWLY PROPAGATES SOUTH. WILL CONTINUE TO MONITOR TRENDS...HOWEVER...LEANED CLOSER TO THE RAP GIVEN WEAK EASTERLY UPSLOPE FLOW. UPDATE ISSUED AT 641 AM CDT TUE OCT 29 2013 HIGH PRESSURE JUST NORTH OF MINNESOTA AT 6 AM CDT WAS RESPONSIBLE FOR KEEPING SKIES MOSTLY CLEAR OVER THE NORTH CENTRAL PORTION OF THE STATE OVERNIGHT. LOWS HERE FELL INTO THE TEENS. SKIES WERE CLOUDY ACROSS THE REMAINDER OF THE FORECAST AREA. ALTHOUGH LIGHT SNOW THAT FELL ACROSS THE SOUTHWEST AND FAR SOUTH CENTRAL HAS NOW DISSIPATED. HAVE UPDATED POPS THIS MORNING...STARTING OUT DRY ACROSS THE CWA. MESOSCALE MODELS CONTINUE TO INDICATE LIGHT PRECIPITATION LIFTING NORTH FROM SOUTH DAKOTA DURING THE DAY SO BROUGHT IN SMALL PRECIPITATION CHANCES ACROSS THE FAR SOUTH DURING THE MORNING AND KEPT THE CHANCE ACROSS THE SOUTH THIS AFTERNOON. CLOUDS CONTINUE TO BUILD FROM WEST TO EAST ACROSS THE NORTH...SO THE MAINLY CLEAR SKIES IN THE NORTH CENTRAL EARLY THIS MORNING SHOULD CLOUD OVER IN THE NEXT FEW HOURS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 329 AM CDT TUE OCT 29 2013 FOCUS OF THE SHORT TERM INCLUDES ANTICIPATED DIMINISHING SNOWFALL THIS MORNING...THEN PRECIPITATION CHANCES AND PRECIP TYPE THIS AFTERNOON AND TONIGHT. AT 3 AM CDT...THE UPPER LEVEL LOW REMAINED OVER THE ROCKIES NEAR NEVADA/IDAHO WITH SOUTHWEST FLOW ALOFT ACROSS THE EASTERN ROCKIES...THE FRONT RANGE...AND INTO THE DAKOTAS. AT THE SURFACE...COLD HIGH PRESSURE WAS CENTERED AT THE BORDER OF MANITOBA/NORTH DAKOTA/MINNESOTA...WITH LOW PRESSURE OVER COLORADO/WYOMING. THIS WAS RESULTING IN MAINLY CLEAR SKIES OVER THE NORTHEASTERN HALF OF NORTH DAKOTA...AND CLOUDS OVER THE SOUTHWEST HALF. LIGHT SNOW FROM ISENTROPIC LIFT/OVERRUNNING PRECIPITATION FROM EASTERN MONTANA ACROSS WESTERN AND SOUTH CENTRAL NORTH DAKOTA INTO NORTHERN SOUTH DAKOTA APPEARED TO BE DECREASING IN INTENSITY AND COVERAGE OVER THE PAST COUPLE OF HOURS...EXCEPT FOR AN ENHANCED AREA OF LIGHT SNOW OVER NORTH CENTRAL/NORTHEASTERN SOUTH DAKOTA THAT WAS MOVING NORTHEASTWARD INTO THE JAMES RIVER VALLEY. THE HRRR 3KM REFLECTIVITY HAS A GOOD HANDLE ON CURRENT RADAR RETURNS AND WILL FOLLOW THIS TREND IN THAT MODEL FOR THE MORNING HOURS. THE HRRR DIMINISHES THE SNOWFALL OVER WESTERN NORTH DAKOTA TO NOTHING AFTER DAYBREAK/12Z. THE MODEL INDICATES SOME CHANCES OF PRECIPITATION IN PORTIONS OF SOUTH CENTRAL/SOUTHEASTERN NORTH DAKOTA DURING THE MORNING HOURS. FEEL CONFIDENT THAT BY 6 AM MDT THE ADVISORY SHOULD BE ALLOWED TO EXPIRE. WILL KEEP SMALL CHANCES OF PRECIPITATION ACROSS THE FAR SOUTHERN TIER OF COUNTIES THIS MORNING. FOR THIS AFTERNOON...THE MODELS DEPICT THE UPPER LOW MOVING NORTHEAST TO WYOMING AND CONTINUED UPPER LEVEL ENERGY IMPULSES MOVING NORTHEASTWARD TOWARDS NORTH DAKOTA. THUS THE MODELS WERE KEEPING PRECIPITATION VERY CLOSE TO THE ND BORDER IN SOUTH DAKOTA...AND WILL KEEP SMALL CHANCE MENTIONS OF LIGHT SNOW OR LIGHT RAIN. HIGH TEMPERATURES EXPECTED TO REACH ONLY INTO THE 30S...BUT WITH WARM ADVECTION ALOFT BRINGING A CHANCE OF RAIN/SNOW TO THE FAR SOUTH. FOR TONIGHT...THE UPPER LOW REMAINS OVER WYOMING WITH CONTINUED ENERGY IMPULSES MOVING NORTHWARD ACROSS THE DAKOTAS. WARM ADVECTION ALOFT CONTINUES WITH SURFACE TEMPERATURES DROPPING BACK INTO THE UPPER 20S. TEMPERATURE PROFILES FROM BUFKIT SOUNDINGS STILL SUPPORT FREEZING RAIN. THUS WILL CONTINUE THE CHANCES OF FREEZING RAIN ACROSS THE SOUTHERN TIER OF COUNTIES AS HAS BEEN ANTICIPATED FOR THE PAST FEW DAYS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 329 AM CDT TUE OCT 29 2013 MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE PRECIPITATION CHANCES AND TYPE WEDNESDAY AND WEDNESDAY NIGHT AS AN UPPER LEVEL LOW MOVES THROUGH THE LOCAL AREA. MODELS ARE IN REASONABLE AGREEMENT AND UTILIZED A MODEL BLEND WITH PERSISTENCE FOR FORECAST ELEMENTS. THE UPPER LEVEL LOW TRACKING ACROSS THE NORTHERN ROCKIES MOVES INTO THE NORTHERN PLAINS WEDNESDAY. THE MAIN SURFACE LOW REMAINS OVER THE CENTRAL PLAINS BUT WARM ADVECTION LIFTS FROM THE PLAINS INTO THE CENTRAL AND EASTERN DAKOTAS ON WEDNESDAY WITH THE GFS/EC AND GLOBAL GEM ALL PRODUCING QPF OVER OUR FAR SOUTH CENTRAL AND SOUTHEAST CWA. WITH SURFACE TEMPERATURES HOVERING AROUND FREEZING AND MAX TEMPERATURES ALOFT GENERALLY 2-4 DEGREES CELSIUS...THERE WILL BE A THREAT OF FREEZING RAIN ALONG THE SOUTH DAKOTA BORDER WEDNESDAY MORNING. AS TEMPERATURES RISE INTO THE UPPER 30S TO LOWER 40S WEDNESDAY AFTERNOON THE PRECIPITATION IS EXPECTED TO BE ALL RAIN. BY WEDNESDAY EVENING THE UPPER LOW MOVES EAST AND COLDER AIR FILTERS INTO THE REGION. BY THIS TIME ANY LINGERING PRECIPITATION IS EXPECTED TO BE MAINLY OVER THE JAMES RIVER VALLEY...AND AS TEMPERATURES COOL DURING THE EVENING WE COULD AGAIN SEE A MIXED BAG OF LIGHT RAIN/FREEZING RAIN OR SNOW BEFORE THE PRECIPITATION ENDS. WILL NEED TO MONITOR FOR POSSIBLE FREEZING RAIN HIGHLIGHTS FAR SOUTH CENTRAL AND SOUTHEAST...BUT AT THIS TIME THE GREATEST POTENTIAL FOR ACCUMULATING PRECIPITATION APPEARS TO BE WEDNESDAY AFTERNOON WHEN TEMPERATURES WILL BE WARM ENOUGH THAT RAIN WILL BE THE PREDOMINANT PRECIPITATION TYPE. NORTHWEST FLOW DEVELOPS THURSDAY INTO FRIDAY. EMBEDDED IMPULSES IN A STRONG NORTHWEST UPPER FLOW COULD BRING A RAIN OR SNOW SHOWER TO THE NORTH AND EAST ON FRIDAY...WITH BREEZY NORTHWEST WINDS EXPECTED ACROSS THE AREA. HIGH TEMPERATURES SHOULD REMAIN IN THE 40S. THE NEXT SYSTEM COMING OFF THE PACIFIC LIFTS INTO SOUTHERN CANADA OVER THE WEEKEND. THIS WILL INDUCE A SOUTHEAST FLOW ACROSS THE AREA LATE SATURDAY THROUGH SUNDAY WITH HIGH TEMPERATURES MAINLY IN THE MID TO UPPER 40S AND POSSIBLY SOME 50S IN THE WEST. A COLD FRONT MOVES THROUGH ON MONDAY BRINGING US BACK DOWN INTO THE UPPER 30S AND 40S. HAVE STUCK WITH PERSISTENCE AND KEPT A SLIGHT CHANCE OF PRECIPITATION ACROSS THE NORTH ON SUNDAY AND MONDAY. ALTHOUGH LATEST GUIDANCE IS SUGGESTING THAT THE LOW OVER SOUTHERN CANADA MAY BE FAR ENOUGH NORTH THAT WE WILL REMAIN IN THE DRY SECTOR...ESPECIALLY ON SUNDAY...WITH MAYBE A FEW COLD ADVECTION RAIN OR SNOW SHOWERS ON MONDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 1017 AM CDT TUE OCT 29 2013 WIDESPREAD STRATUS ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING WILL HOLD IN PLACE FOR MOST TAF SITES TODAY. IFR CONDITIONS WILL PERSIST FOR THE MAJORITY OF THE 12 UTC TAF PERIOD FOR KDIK. OTHERWISE...VFR STRATUS WILL LOWER TO IFR TONIGHT AT KJMS/KBIS WITH FREEZING DRIZZLE POSSIBLE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...JV LONG TERM...TWH AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
641 AM CDT TUE OCT 29 2013 .UPDATE... ISSUED AT 641 AM CDT TUE OCT 29 2013 HIGH PRESSURE JUST NORTH OF MINNESOTA AT 6 AM CDT WAS RESPONSIBLE FOR KEEPING SKIES MOSTLY CLEAR OVER THE NORTH CENTRAL PORTION OF THE STATE OVERNIGHT. LOWS HERE FELL INTO THE TEENS. SKIES WERE CLOUDY ACROSS THE REMAINDER OF THE FORECAST AREA. ALTHOUGH LIGHT SNOW THAT FELL ACROSS THE SOUTHWEST AND FAR SOUTH CENTRAL HAS NOW DISSIPATED. HAVE UPDATED POPS THIS MORNING...STARTING OUT DRY ACROSS THE CWA. MESOSCALE MODELS CONTINUE TO INDICATE LIGHT PRECIPITATION LIFTING NORTH FROM SOUTH DAKOTA DURING THE DAY SO BROUGHT IN SMALL PRECIPITATION CHANCES ACROSS THE FAR SOUTH DURING THE MORNING AND KEPT THE CHANCE ACROSS THE SOUTH THIS AFTERNOON. CLOUDS CONTINUE TO BUILD FROM WEST TO EAST ACROSS THE NORTH...SO THE MAINLY CLEAR SKIES IN THE NORTH CENTRAL EARLY THIS MORNING SHOULD CLOUD OVER IN THE NEXT FEW HOURS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 329 AM CDT TUE OCT 29 2013 FOCUS OF THE SHORT TERM INCLUDES ANTICIPATED DIMINISHING SNOWFALL THIS MORNING...THEN PRECIPITATION CHANCES AND PRECIP TYPE THIS AFTERNOON AND TONIGHT. AT 3 AM CDT...THE UPPER LEVEL LOW REMAINED OVER THE ROCKIES NEAR NEVADA/IDAHO WITH SOUTHWEST FLOW ALOFT ACROSS THE EASTERN ROCKIES...THE FRONT RANGE...AND INTO THE DAKOTAS. AT THE SURFACE...COLD HIGH PRESSURE WAS CENTERED AT THE BORDER OF MANITOBA/NORTH DAKOTA/MINNESOTA...WITH LOW PRESSURE OVER COLORADO/WYOMING. THIS WAS RESULTING IN MAINLY CLEAR SKIES OVER THE NORTHEASTERN HALF OF NORTH DAKOTA...AND CLOUDS OVER THE SOUTHWEST HALF. LIGHT SNOW FROM ISENTROPIC LIFT/OVERRUNNING PRECIPITATION FROM EASTERN MONTANA ACROSS WESTERN AND SOUTH CENTRAL NORTH DAKOTA INTO NORTHERN SOUTH DAKOTA APPEARED TO BE DECREASING IN INTENSITY AND COVERAGE OVER THE PAST COUPLE OF HOURS...EXCEPT FOR AN ENHANCED AREA OF LIGHT SNOW OVER NORTH CENTRAL/NORTHEASTERN SOUTH DAKOTA THAT WAS MOVING NORTHEASTWARD INTO THE JAMES RIVER VALLEY. THE HRRR 3KM REFLECTIVITY HAS A GOOD HANDLE ON CURRENT RADAR RETURNS AND WILL FOLLOW THIS TREND IN THAT MODEL FOR THE MORNING HOURS. THE HRRR DIMINISHES THE SNOWFALL OVER WESTERN NORTH DAKOTA TO NOTHING AFTER DAYBREAK/12Z. THE MODEL INDICATES SOME CHANCES OF PRECIPITATION IN PORTIONS OF SOUTH CENTRAL/SOUTHEASTERN NORTH DAKOTA DURING THE MORNING HOURS. FEEL CONFIDENT THAT BY 6 AM MDT THE ADVISORY SHOULD BE ALLOWED TO EXPIRE. WILL KEEP SMALL CHANCES OF PRECIPITATION ACROSS THE FAR SOUTHERN TIER OF COUNTIES THIS MORNING. FOR THIS AFTERNOON...THE MODELS DEPICT THE UPPER LOW MOVING NORTHEAST TO WYOMING AND CONTINUED UPPER LEVEL ENERGY IMPULSES MOVING NORTHEASTWARD TOWARDS NORTH DAKOTA. THUS THE MODELS WERE KEEPING PRECIPITATION VERY CLOSE TO THE ND BORDER IN SOUTH DAKOTA...AND WILL KEEP SMALL CHANCE MENTIONS OF LIGHT SNOW OR LIGHT RAIN. HIGH TEMPERATURES EXPECTED TO REACH ONLY INTO THE 30S...BUT WITH WARM ADVECTION ALOFT BRINGING A CHANCE OF RAIN/SNOW TO THE FAR SOUTH. FOR TONIGHT...THE UPPER LOW REMAINS OVER WYOMING WITH CONTINUED ENERGY IMPULSES MOVING NORTHWARD ACROSS THE DAKOTAS. WARM ADVECTION ALOFT CONTINUES WITH SURFACE TEMPERATURES DROPPING BACK INTO THE UPPER 20S. TEMPERATURE PROFILES FROM BUFKIT SOUNDINGS STILL SUPPORT FREEZING RAIN. THUS WILL CONTINUE THE CHANCES OF FREEZING RAIN ACROSS THE SOUTHERN TIER OF COUNTIES AS HAS BEEN ANTICIPATED FOR THE PAST FEW DAYS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 329 AM CDT TUE OCT 29 2013 MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE PRECIPITATION CHANCES AND TYPE WEDNESDAY AND WEDNESDAY NIGHT AS AN UPPER LEVEL LOW MOVES THROUGH THE LOCAL AREA. MODELS ARE IN REASONABLE AGREEMENT AND UTILIZED A MODEL BLEND WITH PERSISTENCE FOR FORECAST ELEMENTS. THE UPPER LEVEL LOW TRACKING ACROSS THE NORTHERN ROCKIES MOVES INTO THE NORTHERN PLAINS WEDNESDAY. THE MAIN SURFACE LOW REMAINS OVER THE CENTRAL PLAINS BUT WARM ADVECTION LIFTS FROM THE PLAINS INTO THE CENTRAL AND EASTERN DAKOTAS ON WEDNESDAY WITH THE GFS/EC AND GLOBAL GEM ALL PRODUCING QPF OVER OUR FAR SOUTH CENTRAL AND SOUTHEAST CWA. WITH SURFACE TEMPERATURES HOVERING AROUND FREEZING AND MAX TEMPERATURES ALOFT GENERALLY 2-4 DEGREES CELSIUS...THERE WILL BE A THREAT OF FREEZING RAIN ALONG THE SOUTH DAKOTA BORDER WEDNESDAY MORNING. AS TEMPERATURES RISE INTO THE UPPER 30S TO LOWER 40S WEDNESDAY AFTERNOON THE PRECIPITATION IS EXPECTED TO BE ALL RAIN. BY WEDNESDAY EVENING THE UPPER LOW MOVES EAST AND COLDER AIR FILTERS INTO THE REGION. BY THIS TIME ANY LINGERING PRECIPITATION IS EXPECTED TO BE MAINLY OVER THE JAMES RIVER VALLEY...AND AS TEMPERATURES COOL DURING THE EVENING WE COULD AGAIN SEE A MIXED BAG OF LIGHT RAIN/FREEZING RAIN OR SNOW BEFORE THE PRECIPITATION ENDS. WILL NEED TO MONITOR FOR POSSIBLE FREEZING RAIN HIGHLIGHTS FAR SOUTH CENTRAL AND SOUTHEAST...BUT AT THIS TIME THE GREATEST POTENTIAL FOR ACCUMULATING PRECIPITATION APPEARS TO BE WEDNESDAY AFTERNOON WHEN TEMPERATURES WILL BE WARM ENOUGH THAT RAIN WILL BE THE PREDOMINANT PRECIPITATION TYPE. NORTHWEST FLOW DEVELOPS THURSDAY INTO FRIDAY. EMBEDDED IMPULSES IN A STRONG NORTHWEST UPPER FLOW COULD BRING A RAIN OR SNOW SHOWER TO THE NORTH AND EAST ON FRIDAY...WITH BREEZY NORTHWEST WINDS EXPECTED ACROSS THE AREA. HIGH TEMPERATURES SHOULD REMAIN IN THE 40S. THE NEXT SYSTEM COMING OFF THE PACIFIC LIFTS INTO SOUTHERN CANADA OVER THE WEEKEND. THIS WILL INDUCE A SOUTHEAST FLOW ACROSS THE AREA LATE SATURDAY THROUGH SUNDAY WITH HIGH TEMPERATURES MAINLY IN THE MID TO UPPER 40S AND POSSIBLY SOME 50S IN THE WEST. A COLD FRONT MOVES THROUGH ON MONDAY BRINGING US BACK DOWN INTO THE UPPER 30S AND 40S. HAVE STUCK WITH PERSISTENCE AND KEPT A SLIGHT CHANCE OF PRECIPITATION ACROSS THE NORTH ON SUNDAY AND MONDAY. ALTHOUGH LATEST GUIDANCE IS SUGGESTING THAT THE LOW OVER SOUTHERN CANADA MAY BE FAR ENOUGH NORTH THAT WE WILL REMAIN IN THE DRY SECTOR...ESPECIALLY ON SUNDAY...WITH MAYBE A FEW COLD ADVECTION RAIN OR SNOW SHOWERS ON MONDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 641 AM CDT TUE OCT 29 2013 AT 630 AM CDT...A LARGE SURFACE HIGH PRESSURE WAS CENTERED OVER THE BORDERS OF MANITOBA/NORTH DAKOTA/MINNESOTA...WITH LOW PRESSURE OVER COLORADO/WYOMING. THESE 2 FEATURES ARE FORECAST TO MOVE EAST TODAY. MVFR CIGS WERE WEST OF KISN IN NORTHEASTERN MONTANA...THUS PUT A TEMPO GROUP FOR A FEW HOURS THIS MORNING AT KISN/KDIK. OTHERWISE VFR AT KBIS/KJMS/KMOT. LATER THIS TUESDAY EVENING A LARGE AREA OF LOW/MID CLOUDINESS SHOULD MOVE NORTHWARD BRINGING MVFR CIGS TO SOUTHERN TAF SITES OF KDIK/KBIS/KJMS AFT 02Z. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...JV LONG TERM...TWH AVIATION...TWH
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
953 AM EDT TUE OCT 29 2013 .SYNOPSIS... HIGH PRESSURE WILL RACE EAST ACROSS THE GREAT LAKES REGION TO THE EAST COAST BY TONIGHT. A STATIONARY FRONT JUST SOUTH OF THE AREA WILL MOVE NORTH AS A WARM FRONT WEDNESDAY. LOW PRESSURE WILL MOVE NORTHEAST ACROSS LAKE SUPERIOR THURSDAY. A COLD FRONT WILL MOVE EAST ACROSS THE REGION LATE THURSDAY NIGHT. A REINFORCING COLD FRONT WILL MOVE EAST ACROSS THE AREA ON SATURDAY AS LOW PRESSURE DEVELOPS OVER LAKE HURON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FAIR WEATHER WILL CONTINUE INTO THE AFTERNOON AS HIGH CLOUDS GRADUALLY INCREASE ACROSS THE REGION. LINGERING FOG NEAR MNN WILL DISSIPATE SOON. DIFFUSE WEAK FRONT OVER SOUTHERN WV AND OHIO WILL DRIFT NORTHWARD TOWARD EVENING. HRRR TEMPERATURE FORECAST FOR THE AFTERNOON IS SUPPORTED BY THE 12Z SOUNDINGS AT DTX AND ILN. HAVE ONLY MADE MINOR CHANGES TO THE HIGH TEMPERATURE FORECAST. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... CHANGES ARE ON THE WAY IN THE UPPER LEVEL PATTERN THROUGH FRIDAY NIGHT. WHAT IS NEARLY ZONAL FLOW TODAY WILL TREND TOWARD THE AMPLIFICATION OF THE RIDGE JUST TO OUR WEST. THIS UPPER LEVEL RIDGE WILL BUILD EAST OVER THE FORECAST AREA WEDNESDAY NIGHT AND MOVE EAST OF THE REGION ON THURSDAY. THIS WILL THEN ALLOW A TROUGH OF LOW PRESSURE ALOFT TO MOVE EAST INTO THE FORECAST AREA BY FRIDAY AND FRIDAY NIGHT. TONIGHT WILL STILL REMAIN QUIET UNDER THE INFLUENCE OF HIGH PRESSURE THAT WILL SETTLE IN OVER THE EASTERN UNITED STATES. THIS SHOULD SET THE MOTION OF THE WARM FRONT TO HEAD NORTH TOWARD THE REGION. THE WARM FRONT WILL MOVE NORTH ACROSS THE FORECAST AREA ON WEDNESDAY. THIS WILL BEGIN THE TRANSITION TO WARM AIR ADVECTION THAT WILL CONTINUE THROUGH EARLY THURSDAY NIGHT. A SURGE OF MOISTURE ASSOCIATED WITH THE WARM FRONT WILL AFFECT THE FORECAST AREA BY LATE WEDNESDAY INTO WEDNESDAY NIGHT AND BRING WITH IT AT LEAST A CHANCE FOR SOME SHOWERS. NOW...THERE IS SOME HINT THAT A DRY SLOT MAY DEVELOP BEHIND THE WARM FRONT AND AHEAD OF THE COLD FRONT ON THURSDAY ACROSS THE AREA. MODEL SOUNDINGS INDICATE THAT SEVERE POTENTIAL WILL BE NON EXISTENT BECAUSE OF THE EXTENSIVE CLOUD COVER AND MOISTURE PRODUCING NIL CAPE. HOWEVER...I DO BELIEVE WE WILL SEE SOME BREAKS OF SUN DURING THE DAY ON THURSDAY AND THERE IS A REMOTE POSSIBILITY THAT WITH DAY TIME HEATING...TEMPERATURES COULD JUMP UP ABOUT 4 TO 5 DEGREES. THIS WILL HELP TO PRODUCE ENOUGH CAPE AND INSTABILITY TO PRODUCE SOME STRONG TO SEVERE THUNDERSTORMS LATE IN THE DAY THURSDAY INTO THURSDAY EVENING. ANOTHER ISSUE IS THE FAIRLY HIGH HELICITY VALUES EXPECTED THURSDAY AFTERNOON INDICATING THE POTENTIAL FOR ROTATING THUNDERSTORMS. SO...IF ANY THING DEVELOPS THURSDAY...IT WILL HAVE TO BE WATCHED CLOSELY FOR SEVERE THUNDERSTORM POTENTIAL. CURRENT INDICATIONS ARE THAT ANY THREATS WILL BE STRONG DAMAGING WINDS BUT WITH THE HIGH HELICITY POTENTIAL...THERE COULD BE A HIGHER THREAT FOR SEVERE WEATHER. COLD FRONT SWEEPS EAST OF THE AREA LATE THURSDAY NIGHT INTO FRIDAY MORNING ENDING THE THREAT FOR SEVERE WEATHER. COLD AIR MASS BEHIND THE COLD FRONT IS NOT EXPECTED TO BE VERY STRONG SO HIGHS ON FRIDAY WILL ONLY BE KNOCKED DOWN A PEG OR TWO. THE TRUE COLD FRONT DOES NOT ARRIVE UNTIL SATURDAY. A RETURN TO WINTER WEATHER SHAPING UP FOR THE WEEKEND. && .LONG TERM /SATURDAY THROUGH MONDAY/... AN UPPER TROF WILL CROSS THE AREA ON SATURDAY AND THAT WILL CAUSE A THREAT OF SHOWERS ACROSS THE ENTIRE FORECAST AREA WITH THE BEST CHANCE OVER THE SNOW BELT AREA...BECAUSE THE MOISTURE AND OMEGA IS BEST. ON SATURDAY NIGHT IT COULD BE COLD ENOUGH FOR SOME RAIN AND SNOW MIX...MAINLY OVER NORTHEAST OHIO AND NW PA. ON SUNDAY THE AIR MASS IS DRYING OUT AND HIGH PRESSURE IS BUILDING IN QUICKLY FORM THE WEST...HOWEVER...A THREAT OF SHOWERS WILL CONTINUE ESPECIALLY OVER NW PA. FOR MONDAY HIGH PRESSURE WILL BE IN CONTROL WITH DRY WEATHER. THE MODELS ARE IN GENERAL AGREEMENT. USED A BLEND OF GUIDANCE FOR THE TEMPERATURE FORECAST. READINGS WILL BE NEAR OR JUST BELOW NORMAL. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... HIGH PRESSURE OVER THE NORTHERN GREAT LAKES WILL KEEP A NORTHEAST OR EAST FLOW OVER THE REGION THROUGH EARLY EVENING. SATELLITE PICTURES AND OBSERVATIONS SHOW SOME LOW CLOUDS OVER LAKE ERIE. THE QUESTION IS WILL THOSE CLOUDS MAKE IT INTO THE FORECAST AREA. CONFIDENCE IS LOW BUT SOME CEILINGS COULD FORM MAINLY ALONG THE LAKESHORE THROUGH THE MORNING. OTHERWISE SOME SCATTERED CUMULUS IS EXPECTED WITH SOME CIRRUS THIS AFTERNOON. SOME FOG WILL OCCUR THROUGH 14Z/10 AM EDT. AS THE FLOW BECOMES SOUTHEAST THIS EVENING ANY REMAINING LOW CLOUDS WILL GO AWAY AND ONLY HIGH CLOUDS WILL BE LEFT. SOME MID CLOUDS WILL BE COMING IN FROM THE WEST LATE TONIGHT. OUTLOOK...SOME NON-VFR POSSIBLE WEDNESDAY EVENING THROUGH FRIDAY AND MAINLY AROUND THE SNOWBELT FRI NIGHT AND SAT. && .MARINE... HIGH PRESSURE OVER THE NORTHERN LAKES TODAY WILL DRIFT SLOWLY EAST THROUGH WEDNESDAY NIGHT. A WARM FRONT WILL MOVE ACROSS THE LAKE WEDNESDAY NIGHT AND THEN A COLD FRONT WILL CROSS LAKE ERIE EARLY FRIDAY. IN THE MEANTIME EAST WINDS WILL BE ON THE DECREASE TODAY...SO NO SMALL CRAFT ADVISORY WILL BE NEEDED. THE NEXT THREAT FOR A SMALL CRAFT ADVISORY WILL BE THURSDAY THROUGH THE WEEKEND. ON THURSDAY IN A STRONG SOUTHWEST FLOW CONDITIONS SHOULD MEET SMALL CRAFT ADVISORY CRITERIA AND THEN EARLY FRIDAY INTO THE WEEKEND WHEN THE COLD ADVECTION STARTS. CONDITIONS COULD BE CLOSE TO GALES FOR SHORT TIME EARLY FRIDAY AFTER THE FRONTAL PASSAGE. ON THE EDGE WHETHER WILL COULD HAVE GALE FORCE WINDS IN THE WARM ADVECTION. OTHERWISE THE CONDITIONS WILL BE CLOSE TO SMALL CRAFT ADVISORY CONDITIONS FOR MUCH OF THE UPCOMING WEEKEND. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...LOMBARDY NEAR TERM...LAPLANTE SHORT TERM...LOMBARDY LONG TERM...KIELTYKA AVIATION...KIELTYKA MARINE...KIELTYKA
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
642 AM CDT TUE OCT 29 2013 .DISCUSSION...UPDATED FOR 06 AVIATION. && .AVIATION...MIX OF VFR/MVFR CEILINGS EXIST ACROSS SOUTH TEXAS TERMINALS THIS MORNING. ANY MVFR CEILINGS WILL MIX OUT BY 14Z OR 15Z. SOUTHEAST TO SOUTH SOUTHEAST WINDS WILL INCREASE TODAY WITH SOME GUSTS BETWEEN 25 AND 30 KNOTS THIS AFTERNOON. WINDS WILL DIMINISH AROUND 00Z...BUT REMAIN ELEVATED AT LRD THROUGH THE EVENING. LLJ OF 30 TO 35 KNOTS WILL DEVELOP TONIGHT WHICH SHOULD KEEP FOG POTENTIAL LOW...BUT MVFR STRATUS WILL AGAIN BE COMMON. CEILINGS MAY FALL BELOW MVFR TONIGHT...BUT CONFIDENCE IS TOO LOW TO MENTION IN THE TAFS ATTM. && .PREV DISCUSSION... /ISSUED 432 AM CDT TUE OCT 29 2013/ SHORT TERM (TODAY THROUGH WEDNESDAY)...DEEP SOUTHERLY FLOW THROUGH THE LOWER PARTS OF THE ATMOSPHERE WILL BRING MOISTURE BACK INTO SOUTH TEXAS DURING THE SHORT TERM. STRATUS HAS DEVELOPED ACROSS MUCH OF SOUTH TEXAS OVERNIGHT BUT ANTICIPATE THE LOW CLOUDS TO MIX OUT LATER THIS MORNING. LATEST RUN HRRR PICKING UP ON SOME SHOWER ACTIVITY THROUGH THE MORNING AND HAVE INCLUDED A 10 POP WITH MENTION OF SHOWERS THROUGH 18Z. UPPER LOW OVER THE WESTERN CONUS WILL SLOWLY MOVE TO THE EAST TODAY...INTO FOUR CORNERS REGION ON WEDNESDAY. PRESSURE GRADIENT WILL STRENGTHEN OVER SOUTH TEXAS TODAY WITH SOUTHEASTERLY WINDS INCREASING BY THE AFTERNOON. SOME GUSTS AROUND 30 MPH WILL BE POSSIBLE ACROSS THE COASTAL BEND AND OVER THE RIO GRANDE PLAINS. HIGH TEMPS TODAY WILL AGAIN BE ABOVE NORMAL WITH UPPER 80S ACROSS EASTERN SECTIONS TO LOWER 90S OUT WEST. ON WEDNESDAY...DEEPER MOISTURE WILL GET DRAWN INTO SOUTH TEXAS AS LOW LEVEL FLOW REMAINS OUT OF THE SE AND SSE. PW VALUES WILL CLIMB TO NEAR 2 INCHES (2.1 INCHES IF THE GFS VERIFIES) AS DISTURBANCE SCOOTS TO THE NORTH OF THE AREA. HIGHEST CHANCES FOR SHOWERS AND STORMS ON WEDNESDAY WILL EXIST ACROSS THE NORTHEAST ZONES WHERE CAPPING WILL BE THE WEAKEST. POPS RANGE FROM SLIGHT CHANCE OVER THE SOUTHWEST ZONES TO LIKELY IN THE NORTHEAST SECTIONS. TEMPS ON WEDNESDAY WILL BE SIMILAR TO TODAY...EXCEPT OVER THE NORTHEAST WHERE BETTER RAIN CHANCES AND CLOUD COVER MAY KEEP TEMPS DOWN A FEW DEGREES. YET ANOTHER BREEZY TO WINDY DAY ON WEDNESDAY IN ADVANCE OF THURSDAY/S FROPA. MARINE/COASTAL...ONSHORE FLOW BEGIN TO INCREASE ACROSS THE GULF WATERS TODAY AS GRADIENT STRENGTHENS OVER THE AREA. SMALL CRAFT ADVISORY CONDITIONS WILL DEVELOP THIS EVENING WITH WINDS OF 20 TO 25 KNOTS. IN ADDITION...SEAS WILL CLIMB TO 7 TO 8 FEET OVER THE WATERS. THESE CONDITIONS WILL LIKELY CONTINUE INTO WEDNESDAY IN ADVANCE OF A COLD FRONT. THE SOUTHERN BAYS MAY FLIRT WITH SMALL CRAFT ADVISORY CONDITIONS TODAY BUT CONFIDENCE IS NOT HIGH ENOUGH TO ISSUE AN SCA AT THIS TIME. REGARDING THE RIP CURRENT RISK... SWELLS APPEAR TO BE FINALLY LOWERING A BIT...BUT THE STRONG ONSHORE FLOW THAT IS EXPECTED WARRANT CONTINUING THE RIP CURRENT STATEMENT FOR NOW. IF CONDITIONS IMPROVE...THEN LATER SHIFTS MAY CANCEL EARLY. LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...MODELS CONTINUE TO BE IN AGREEMENT WITH BRINGING A COLD FRONT THROUGH S TX ON THU...WITH SUBTLE DIFFERENCES IN TIMING AND STRENGTH. WED NIGHT AHD OF THE FRONT...MODELS PROG PWATS OF AROUND 2 INCHES ACROSS S TX. THIS DEEP MOISTURE IS PROGD TO COMBINE WITH AN UPPER LEVEL SHORT WAVE TO PRODUCE SCT TO NUM SHRA/TSRAS ACROSS THE NRN PORTIONS OF THE CWA. THE CAPPING INVERSION WILL BE TOO STRONG ACROSS THE SRN CWA WED NIGHT...HOWEVER AM STILL EXPECTING ISOLD PRECIP DUE TO ABUNDANT MOISTURE ABV THE INVERSION. THE COLD FRONT IS PROGD TO BE PUSHING ACROSS THE NRN CWA BTWN 15-18Z THU. THE VCT CROSSROADS HAS THE HIGHEST POPS DUE TO LITTLE TO NO CAP...HIGHEST CAPE AND PROXIMITY TO THE RRQ OF THE UPPER LEVEL JET. IN ADDITION...MODELS SHOW STRONGEST LOW LEVEL CONVERGENCE ACROSS THE NE CWA. STRONGEST DYNAMICS LOOK TO BE NE OF THE CWA (ACROSS EAST TX AND LA AND EXTENDING NE) WHERE THE STORMS PREDICTION CENTER HAS PLACED A SLIGHT RISK FOR DAY 3. THE NE CWA COULD BE ON THE TAIL END OF THE STRONGER STORMS WITH THE POSSIBILITY OF ISOLD SVR. GIVEN THE ABUNDANT DEEP MOISTURE AND FORCING ALONG THE FRONT...HVY RAIN IS ALSO EXPECTED ACROSS THE NE CWA...HOWEVER THE FRONT IS PROGD TO MOVE FAIRLY QUICKLY RESULTING IN TOTAL RAINFALL AMOUNTS LESS THAN 2 INCHES FOR THE EVENT. ISOLD AMOUNTS COULD BE 2-2.5 INCHES. MAIN CONCERN WOULD BE IF THE FRONT SLOWS OR STALLS SOMEWHERE BETWEEN VCT TO CRP...THEN RAINFALL AMOUNTS COULD BE MUCH HIGHER INTO THU EVENING DURING HALLOWEEN FESTIVITIES. TSRA CHCS ARE LOWER TO THE W DUE TO STRONGER CAP AND WEAKER OVERALL DYNAMICS...BUT STILL SHOULD BE SCT WITH RAINFALL AMOUNTS TOTALING 0.5-1 INCH. AS THE FRONT MOVES SE...SO WILL THE CONVECTION BUT THE HIGHEST POPS ARE EXPECTED TO SHIFT OFFSHORE BY THU EVENING...IF THE FRONT DOES NOT SLOW DOWN. RAIN CHANCES DIMINISH FROM NW TO SE THROUGH THU NIGHT WITH RESIDUAL ELEVATED -SHRAS BRIEFLY BEHIND THE FRONT. DRIER AND SLIGHTLY COOLER CONDITIONS WILL FILTER INTO S TX ON FRI WITH REINFORCING HIGH PRESSURE MVG INTO THE AREA FRI NIGHT. THIS WILL LEAD TO CLRG SKIES AND MILD MORE SEASONABLE TEMPS THROUGH THE WEEKEND. RAIN CHCS BEGIN TO INCREASE ONCE AGAIN BY NEXT MONDAY WITH RETURN FLOW. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 87 75 87 76 86 / 10 20 30 30 50 VICTORIA 87 73 84 72 82 / 10 20 70 60 70 LAREDO 92 76 93 77 90 / 10 10 20 20 40 ALICE 89 73 89 74 87 / 10 20 30 30 40 ROCKPORT 86 76 84 76 85 / 10 20 40 40 70 COTULLA 90 74 88 72 85 / 10 10 30 40 40 KINGSVILLE 89 75 90 76 87 / 10 20 30 30 40 NAVY CORPUS 85 77 86 78 84 / 10 20 30 30 40 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...RIP CURRENT RISK THROUGH LATE TONIGHT FOR THE FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES. GM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT WEDNESDAY 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...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. && $$ TB/78...AVIATION
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
925 AM EDT TUE OCT 29 2013 .SYNOPSIS... A WEAK FRONT EXTENDED FROM VIRGINIA TO A LOW IN KANSAS MISSOURI...WHILE HIGH PRESSURE COVERED THE NORTHERN PLAINS TO THE GREAT LAKES. TUESDAY AND WEDNESDAY THE LOW WILL DEEPEN OVER THE CENTRAL PLAINS AND MOVE SLOWLY NORTHEAST. BY FRIDAY THE LOW WILL BE OVER THE GREAT LAKES AND A STRONG COLD FRONT WILL MOVE ACROSS THE EASTERN UNITED STATES. && .NEAR TERM /THROUGH TONIGHT/... AS OF 915 AM EDT TUESDAY... LOW CLOUDS AND FOG WILL SLOWLY LIFT OR ERODE WITH MIXING AND HEATING THIS MORNING. THIS MORNING 12Z/8AM RNK SOUNDING SHOWED LOW LEVEL MOISTURE UP TO 850 MB WITH THE NORTHWEST FLOW JUST ABOVE THE SURFACE. HRRR AND RNK WRFARW INDICATED LIGHT RAIN DEVELOP AFTER 18Z THIS AFTERNOON. DECIDED TO CUT BACK ON MORNING POPS INTO THIS AFTERNOON. WILL ALLOW FOR SOME ISOLATED RAIN MAINLY ALONG AND WEST OF I77 THIS AFTERNOON INTO TONIGHT. MODIFIED TEMPERATURES...DEW POINTS AND CLOUD COVER WITH LATEST OBS TRENDS FOR THIS MORNING. MORE CHANGES LATER TODAY... AS OF 345 AM EDT TUESDAY... A WEAK STATIONARY BOUNDARY ALONG THE NORTHERN EDGE OF AN AIR MASS WITH HIGHER SURFACE DEW POINTS. SCATTERED RAIN NORTH OF BLUEFIELD AND ROANOKE EARLY THIS MORNING WAS MOVING EAST AND DISSIPATING. DO NOT THINK THE PROBABILITY OF RAIN WILL COMPLETELY GO AWAY BUT JUST BE AT A MINIMUM TODAY. BY THIS EVENING ANOTHER SHORT WAVE TRACKING ALONG THE NORTHERN FRINGE OF BUILDING UPPER RIDGE WILL BE REACHING THE WESTERN COUNTY WARNING AREA. MODELS WERE ALSO SHOWING BETTER ISENTROPIC LIFT TONIGHT AROUND THE 290K LEVEL. EXPECT PROBABILITY OF PRECIPITATION TO INCREASE AND GRADUALLY MOVE EAST OVERNIGHT. WITH ALL THE CLOUD COVER TODAY...AGAIN WENT COOLER THAN GUIDANCE FOR MAXIMUM TEMPERATURES IN THE MOUNTAINS TODAY. GUIDANCE FOR MONDAY WAS TOO WARM IN THIS AREA. EAST OF THE BLUE RIDGE USED A BLEND OF BIAS CORRECTED ADJMET/ADJMAV NUMBERS. 850 MB START OUT FROM THE WEST TODAY AND EVENTUALLY BECOME SOUTH TONIGHT. WITH WEAK WARM ADVECTION AND ABUNDANT CLOUD COVER...TEMPERATURES WILL HAVE A LIMITED DROP OVERNIGHT...ESPECIALLY ALONG THE RIDGES. STAYED CLOSER TO WARMER MET GUIDANCE FOR MINIMUM TEMPERATURES. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... AS OF 330 AM EDT TUESDAY... FOR WEDNESDAY...MODELS ARE IN BETTER AGREEMENT THIS MORNING THAT WE WILL START THE DAY OFF WITH A WARM FRONT SITUATED NEAR THE INTERSTATE 64 CORRIDOR. MINOR DISTURBANCES RIDING ALONG THE BOUNDARY FROM THE WEST WILL PASS ACROSS OUR AREA DURING THE MORNING AND EARLY AFTERNOON...TRIGGERING SPOTTY SHOWERS GENERALLY WITH LIGHT RAINFALL AMOUNTS. THE FRONT WILL LIFT NORTH THROUGH THE DAY...LEAVING THE MID ATLANTIC SITUATED IN AN AREA OF STRONG SOUTHWESTERLY WINDFLOW. RISING 500MB HEIGHTS AS AN UPPER LEVEL RIDGE BUILDS IN FROM THE WEST WILL ALLOW THE WARMUP TO CONTINUE...AS AFTERNOON HIGHS RANGE FROM THE MID/UPPER 60S ACROSS THE MOUNTAINS...TO THE LOW 7OS FURTHER EAST. SHOWER ACTIVITY WILL INCREASE ON THURSDAY AS A DEEP LOW PRESSURE SYSTEM PASSES ACROSS THE WESTERN GREAT LAKES...DRAGGING A STRONG COLD FRONT EAST FROM THE MISSISSIPPI RIVER VALLEY. STUCK CLOSER TO THE NAM/ECMWF/CANADIAN MODEL SOLUTIONS RELATIVE TO TIMING OF THE MORE WIDESPREAD SHOWER ACTIVITY...ALL OF WHICH FAVOR HEAVIER RAINFALL ENTERING THE MOUNTAINS DURING THE EVENING. THE UPPER RIDGE AXIS IS EXPECTED TO BE SITUATED ALONG THE APPALACHIAN CHAIN THURSDAY AFTERNOON...AND WHEN FACTORING IN A DELAYED ONSET TO WIDESPREAD RAINFALL...BELIEVE THAT THURSDAY WILL BE THE WARMEST DAY FOR MOST AREAS...LIKELY ONLY A DEGREE OR TWO OVER WEDNESDAY`S HIGHS HOWEVER. SHOWER ACTIVITY IS EXPECTED TO BECOME WIDESPREAD DURING THE EARLY HOURS OF FRIDAY. MODELS CONTINUE TO SUGGEST LOW CAPE/INSTABILITY AS THE SUPPORTING UPPER LEVEL TROUGH MOVES ACROSS FROM THE WEST...BUT VERY HIGH SHEAR AND HELICITY AS A 50KT TO 60KT LOW LEVEL JET DEVELOPS. BELIEVE THESE CONDITIONS WILL SUPPORT MAINLY STRONG SHOWERS WITH ONLY MINIMAL LIGHTNING...BUT THAT THE STRONGER SHOWERS WILL BE CAPABLE OF DRAWING SOME OF THE STRONGER WINDS ALOFT DOWN TO THE SURFACE...RESULTING IN GUSTY AND LOCALLY DAMAGING WINDS. THE HIGH SHEAR AND HELICITY ALSO MEAN THAT ISOLATED AND SHORT LIVED TORNADOES WILL BE POSSIBLE. AREAS ALONG AND EAST OF THE BLUE RIDGE WILL HAVE A BETTER THREAT FOR SEVERE WEATHER...AS THE SMOOTHER TERRAIN WILL ALLOW FOR BETTER ORGANIZATION OF CONVECTION. IN ADDITION...IF TIMING OF THE UPPER TROUGH IS DELAYED ANY...DAYTIME HEATING MAY ENHANCE THE CONVECTION ACROSS THE PIEDMONTS. HEAVIEST RAINFALL WILL MOVE EAST OF OUR AREA BY EARLY AFTERNOON ON FRIDAY...WITH LINGERING SHOWER ACTIVITY EXPECTED THROUGH EVENING. MILD AIR WILL REMAIN OVER OUR AREA THROUGH FRIDAY NIGHT...WITH THE TRULY COLDER AIR NOT EXPECTED TO ARRIVE UNTIL AFTER SUNRISE SATURDAY. && .LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 100 PM EDT MONDAY... ON SATURDAY...WINDS WILL BECOME INCREASINGLY NORTHWESTERLY IN THE WAKE OF THE DEPARTING COLD FRONT. THIS WILL ALLOW FOR GOOD DOWNSLOPE CLEARING OF SKIES EAST OF THE CREST OF THE BLUE RIDGE. ACROSS THE MOUNTAINS...THE FLOW WILL BE UPSLOPE AND EXPECT THE DEVELOPMENT OF THE RAIN/SNOW SHOWERS ACROSS THE PREFERRED UPSLOPE REGIONS OF MAINLY SOUTHEAST WEST VIRGINIA...ACCOMPANYING COUNTIES OF SOUTHWEST VIRGINIA...AND THE NORTHERN MOUNTAINS OF THE NORTH CAROLINA. FLURRIES OR SPRINKLES WILL CARRY DOWNSTREAM OF THE MAIN ACTIVITY TO AROUND THE CREST OF THE BLUE RIDGE AND THE NORTH CAROLINA FOOTHILLS. THIS PATTERN WILL CONTINUE THROUGH AT LEAST SUNDAY...WITH GRADUALLY DECREASING COVERAGE OF THE SHOWER ACTIVITY AS 850 MB WINDS WEAKEN AND VEER NORTH TO NORTHEAST. && .AVIATION /13Z TUESDAY THROUGH SATURDAY/... AS OF 730 AM EDT TUESDAY... COMBINATION OF WEAK UPSLOPE LOW LEVEL WINDS AND A WEAK SURFACE BOUNDARY ACROSS WEST VIRGINIA AND VIRGINIA PRODUCED ENOUGH LIFT FOR SCATTERED LIGHT RAIN OVER THE MOUNTAINS. ENOUGH LOW LEVEL MOISTURE AND LIMITED MIXING WILL RESULT IN AREAS OF STRATUS AND FOG THIS MORNING. HIGH CONFIDENCE OF IFR CEILINGS AND VISIBILITIES AT KBLF/KLWB AND KBCB BEFORE THROUGH 15Z/11AM. LATEST LAMP GUIDANCE SUGGESTED IT WOULD TAKE MOST OF THE MORNING FOR CONDITIONS TO IMPROVE AT THESE SITES. KROA/KLYH AND KDAN WILL BE VFR TODAY. THE WEAK FRONT PASSED SOUTH OF KLYH AT 09Z/5AM AS INDICATED BY THE NORTH TO NORTHEAST WINDS AT 5 TO 10 KNOTS. THIS WAS ALSO REFLECTED IN THE MSAS ANALYSIS OF LIFTED INDEX VALUES. ANOTHER SHORT WAVE TRACKS NORTH OF THE UPPER RIDGE TODAY AND REACHES THE CENTRAL APPALACHIANS TONIGHT. TAF SITES IN THE MOUNTAINS WILL LOWER TO MVFR AFTER 05Z/1AM WITH THIS SHORT WAVE. CONFIDENCE IS NOT AS HIGH WITH THE COVERAGE OF LIGHT RAIN WITH THIS SHORT WAVE. FOR NOT HAVE ADDED R- TO THE KBCB/KLWB AND KBLF TAF OVERNIGHT. MVFR-VFR CONDITIONS ARE EXPECTED WEDNESDAY AND THURSDAY WITH EXTENSIVE MID/HIGH CLOUDS. CANNOT RULE OUT OCCASIONAL -SHRA IN ADVANCE OF A STRONG FRONT THURSDAY...BUT THE MAIN BAND OF PRECIPITATION WILL COME THURSDAY NIGHT/FRIDAY WITH HEAVY RAIN SHOWERS AND GUSTY WINDS AND POTENTIAL FOR LOW-LEVEL WIND SHEAR. THIS WILL BRING AT LEAST BRIEF PERIODS OF IFR CIGS/VSYBS AS WELL. IN THE WAKE OF THE COLD FRONT...LOOK FOR INCREASING NORTHWEST FLOW BEHIND THE SURFACE SYSTEM. THIS WILL RESULT IN UPSLOPE RAIN/SNOW SHOWERS ACROSS THE PREFERRED UPSLOPE REGIONS OF SOUTHEAST WEST VIRGINIA SATURDAY INTO SUNDAY ALONG WITH IFR-MVFR CEILINGS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...NF LONG TERM...DS AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
315 PM MDT TUE OCT 29 2013 .SHORT TERM...UPPER LEVEL LOW SPINNING OVER NORTHERN NEVADA THIS AFTERNOON WITH A STRONG JET ON ITS EAST SIDE STRETCHING FROM SOUTHWEST AZ NORTHWARD ACROSS THE WESTERN PART OF CO. ON WATER VAPOR IMAGERY SEE A NICE SIGNAL OF A SHORTWAVE ALSO MOVING ACROSS NORTHWESTERN AZ. A NICE BAND OF CLOUDINESS AND ECHOES IS DEVELOPING IN ASSOCIATION WITH THIS FORCING FROM CENTRAL AZ INTO SW CO AND THERE IS EVEN SOME LIGHTNING SHOWING UP NOW. THIS FEATURE ALONG WITH THE UPPER LEVEL JET WILL SHIFT OVER THE FORECAST AREA TONIGHT AS THE MAIN UPPER LEVEL LOW SPLITS WITH THE NORTHERN PORTION HEADING INTO WY AND THE SOUTHERN PORTION TOWARDS LAS VEGAS OVERNIGHT. THEN THE ENTIRE TROUGH PASSES ACROSS COLORADO TOMORROW INTO TOMORROW NIGHT. LATEST RUNS OF SHORTER TERM MODELS HRRR AND RAP CONTINUE TO EXPAND THE DEVELOPING BAND OF PRECIPITATION OVERNIGHT AND SHIFTING IT FIRST OVER THE MOUNTAINS AND THEN THE FOOTHILLS AND ADJACENT PLAINS WITH THE FIRST SLUG OF MAINLY RAIN SHOWERS INTO THE LOWER ELEVATIONS OF LARIMER COUNTY BEGINNING BY ABOUT 01 TO 02Z. THEN THE BAND EXPANDS SOUTHWARD INTO BOULDER COUNTY AND EVENTUALLY TO A LESSER EXTENT JEFFERSON COUNTY. AGAIN INITIALLY PRECIP WOULD BE MOSTLY RAIN AT LOWER ELEVATIONS THEN MIXING WITH AND CHANGING TO SNOW WESTERN PORTION OF THE PLAINS. COULD BE CLOSE TO ADVISORY CRITERIA IN SOME OF THE FOOTHILLS OF WESTERN BOULDER AND LARIMER COUNTIES BUT NOT ENOUGH CONFIDENCE TO HOIST ANY KIND OF ADVISORY. AND IN THE MOUNTAINS OROGRAPHIC COMPONENT IS NOT VERY GOOD SO AMOUNTS UP TO SEVERAL INCHES SHOULD REMAIN BELOW ANY ADVISORY LIMITS. THERE COULD ALSO BE A BAND OF MORE RAIN SHOWERS DEVELOPING TOWARDS THE NORTHEAST CORNER OF THE STATE WITH MORE SCATTERED SHOWER ACTIVITY IN BETWEEN. BEST CHANCE OF ACCUMULATING SNOWS WOULD BE WEST OF I-25 GENERALLY THOUGH FARTHER EAST AS WE GET INTO LARIMER COUNTY. STILL A TRICKY CALL WITHOUT ANY REAL UPSLOPE COMPONENT OF NOTE SO DO NOT WANT TO GET TOO CARRIED AWAY WITH AMOUNTS BUT DYNAMICS ARE CERTAINLY STRONG ENOUGH. FOR TOMORROW AS NOTED TROUGH AXIS MOVES ACROSS AREA LATER IN THE DAY WHILE AT THE SURFACE FLOW BECOMES GENERALLY NORTHWESTERLY. HIGHER RESOLUTION MODELS ARE INDICATING A LONGMONT ANTICYCLONE FLOW WHICH PUSHES MORE NORTHERLY WINDS INTO THE PALMER DIVIDE REGION AND THERE IS A CHANCE OF SOME SNOW DEVELOPING THERE DURING THE LATER AFTERNOON HOURS...CLOSER TO ANY UPPER LEVEL FORCING WITH THE SOUTHERN PART OF THE TROUGH AS IT LIFTS OUT. OTHERWISE MAYBE SOME RAIN OR SNOW SHOWERS AROUND BUT NOT MUCH EXPECTED ON THE PLAINS HOWEVER SNOW SHOWERS SHOULD BE LIKELY IN THE MOUNTAINS WITH BETTER OROGRAPHIC FLOW AND UNSTABLE LAPSE RATES WITH THE CENTER OF THE TROUGH. .LONG TERM...AN ELONGATED UPPER LEVEL TROUGH CONTINUES TO MAKE ITS WAY ACROSS THE CENTRAL ROCKY MOUNTAIN REGION WEDNESDAY NIGHT. QG LIFT...COLD ADVECTION WILL CONTINUE TO GENERATE SNOW SHOWERS IN THE HIGH COUNTRY...WITH SOME ADDITIONAL SNOW ACCUM ON WEST-NORTHWEST FACING MTN SLOPES. ON THE PLAINS...ANOTHER AREA OF QG FORCING CENTERED OVER SOUTHEAST COLORADO WEDNESDAY EVENING ALSO WARRANTS MENTIONING A CHANCE OF SNOW IN NORTHEAST COLORADO...PARTICULARLY ALONG THE PALMER DIVIDE. ANY ACCUMULATION SHOULD BE MINIMAL AT BEST. OVERNIGHT...UPPER TROUGH PASSES BY AND SOUTHWEST FLOW ALOFT TURNS NORTHWESTERLY. MODELS SHOW WEST-NORTHWEST WINDS INCREASING IN SPEED OVER AND ALONG THE EAST FACE OF THE FRONT RANGE LATE WEDNESDAY NIGHT AND THURSDAY MORNING. CROSS MOUNTAIN WIND COMPONENT AT MTN TOP PEAKS IN THE 30-45KT THURSDAY MORNING DURING THE PD OF STRONGEST COLD AIR ADVECTION. DOWNSLOPE SLOPE DRIES OUT PLAINS AIRMASS BUT SAME NORTHWEST FLOW KEEPS SNOW SHOWERS GOING IN THE HIGH COUNTRY... MAINLY ALONG AND WEST OF THE CONTINENTAL DIVIDE. HOWEVER...ANY ADDITIONAL ACCUMULATION SHOULD BE LIGHT WITH DEPTH OF MOISTURE DECREASING. BY THURSDAY EVENING...MODELS SHOW A WEAK DISTURBANCE SWINGING DOWN FROM WESTERN WYOMING AND POSSIBLY REGENERATING SNOWFALL IN THE HIGH COUNTRY. MAY ALSO SEE SOME BANDED LIGHT PRECIP IN THE FORM OF LIGHT RAIN ON THE PLAINS...AND MOST LIKELY ENDING BEFORE MORNING. FRIDAY THROUGH SUNDAY...UPPER TROUGH MARCHES EAST ACROSS THE CENTRAL ROCKY MTN REGION CAUSING TEMPERATURES TO WARM AND PROVIDING PLENTY OF CLEAR SKIES. FRIDAY LOOKS QUITE WINDY IN THE NORTHERN FOOTHILLS AND ACROSS THE NORTHEAST PLAINS. COULD SEE WIND SPEEDS APPROACHING 55 MPH IN THE FOOTHILLS AND 45 MPH ON THE FAR NORTHEAST PLAINS. SPEEDS WOULD NOT WARRANT THE ISSUANCE OF A HIGH WIND WATCH. SHOULD SEE STRONG NORTHWEST FLOW ALOFT QUICKLY DECOUPLING FOR THE BOUNDARY LAYER RESULTING IN A RAPID DROP OFF IN SFC WIND SPEEDS DURING THE EVENING. LOOKING AHEAD TO EARLY NEXT WEEK...MEDIUM RANGE MODELS STILL SHOW A PACIFIC WEATHER SYSTEM/UPPER TROUGH QUICKLY DIVING IN OVER WYOMING AND NORTHWEST COLORADO ON MONDAY. SYSTEM APPEARS TO BE PACKING A DECENT AMOUNT OF COLD AIR. SHOULD THIS SYSTEM PROGRESS AS MODELS INDICATE COULD SEE 24-36 HOURS OF WINTRY WEATHER IN THE HIGH COUNTRY...AND POSSIBLY ON THE PLAINS. HENCE THE CHANCE POPS FOR MONDAY AND TUESDAY. && .AVIATION...CLEARING SKIES HAVE GOTTEN CLOSE TO DIA BUT NOW CLOUD LINE IS SHIFTING SOUTH AGAIN IN NORTHERLY FLOW ON THE BACK SIDE OF A MODEST DENVER CYCLONE. SO CONTINUE LOW CLOUDS BUT FOG SHOULD STAY AWAY TONIGHT WHILE EVENTUALLY BAND OF RAIN SHOWERS MOVES ONTO THE PLAINS CHANGING TO SNOW LATE...MOST LIKELY FOR ANY SNOW AT BJC. && .HYDROLOGY...MODEST AMOUNTS OF SNOW POSSIBLE INTO THE FOOTHILLS ESPECIALLY OF BOULDER AND LARIMER COUNTIES OTHERWISE PRECIPITATION AMOUNTS SHOULD BE GENERALLY BELOW A QUARTER OF AN INCH OR SO OVERNIGHT AND QUITE A BIT LESS IN MOST AREAS. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SZOKE LONG TERM....BAKER AVIATION...SZOKE
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1100 AM MDT TUE OCT 29 2013 .UPDATE...UPPER LEVEL LOW CURRENTLY SPINNING OVER NORTHERN NEVADA WITH EMBEDDED SHORTWAVES ROTATING AROUND IT AND A STRONG UPPER LEVEL JET ON ITS EAST SIDE STRETCHING FROM NW COLORADO BACK TO FAR SOUTHERN CALIFORNIA. THE JET IS SUPPORTING ONE BAND OF PRECIPITATION NOW OVER WEST-CENTRAL COLORADO THAT IS HEADING MORE TO THE NORTH OF BOU FORECAST AREA. THE JET CONTINUES TO SHIFT EASTWARD LATER TODAY AND THEN IS OVER EASTERN COLORADO TONIGHT WITH THE ASSOCIATED UPPER LEVEL FORCING ALSO SHIFTING EASTWARD. SO EXPECT CLOUDS TO INCREASE ACROSS THE HIGH COUNTRY THIS AFTERNOON WITH SNOW SHOWERS GRADUALLY INCREASING LATER IN THE DAY AND THEN OVERNIGHT AS LOWER LEVEL FLOW BECOMES MORE OROGRAPHICALLY FAVORABLE. ON THE PLAINS TRICKY FORECAST FOR CLOUDINESS WITH ERROSION OF CLOUDS NOW ACROSS WESTERN PORTIONS OF THE PALMER DIVIDE AND AM UPDATING THE GRIDS RIGHT NOW FOR THIS. SOME ERROSION FROM THE WEST TOO BUT EXPECT A GRADUALLY INCREASING BUT STILL WEAKISH DENVER CYCLONE THIS AFTERNOON THAT WILL LIKELY KEEP THE LOWER CLOUDS SOCKED IN OVER MOST OF THE LOWER PLAINS. VISIBILITIES THOUGH ARE IMPROVING AND WILL DROP THE FOG ADVISORY FOR THE EASTERN PLAINS. MAY TWEAK HIGH TEMPERATURES TODAY FOR A LITTLE COOLER NORTH AND SLIGHTLY MILDER FAR SOUTH ON THE PLAINS. STILL ASSESSING SITUATION FOR TONIGHT WITH THE OPERATIONAL GFS AND NAM CONSISTENT IN POINTING TO BEST CHANCE OF A BAND OF PRECIP WITH SNOW IN THE FOOTHILLS AND SOME RAIN TO SNOW PLAINS MORE FROM BOULDER COUNTY NORTHWARDS. DOES NOT LOOK LIKE A SIGNIFICANT EVENT BUT COULD BE A FEW INCHES ESPECIALLY IN THE FOOTHILLS PER THE LATTEST RAP AND HRRR RUNS. && .AVIATION...AMENDED TAFS FOR IMPROVING VISIBILITIES AND GRADUAL LIFTING OF CEILINGS TODAY. AT THIS TIME ANY SIGNIFICANT PRECIPITATION SHOULD STAY NORTH OF DIA TONIGHT. && .HYDROLOGY...COULD BE A FEW INCHES OF SNOW IN THE FOOTHILLS OF BOULDER AND LARIMER COUNTY OVERNIGHT WITH THE BAND NOTED ABOVE AND SOME SNOW IN MOUNTAIN LOCATIONS BUT FORCING AND OROGRAPHIC FLOW DO NOT APPEAR TO BE SIGNIFICANT ENOUGH FOR ANY HIGHLIGHTS AT THIS TIME. && .PREV DISCUSSION... /ISSUED 834 AM MDT TUE OCT 29 2013/ UPDATE... SHORT TERM...JUST ISSUED A SHORT FUSED DENSE FOG ADVISORY FOR PORTIONS OF COLORADO/S NORTHEAST PLAINS. VISIBILITIES HAS CONTINUED TO VARY FROM 1/4 TO 1 MILE AT SEVERAL LOCALES IN MORGAN...WASHINGTON...SEDQWICK AND PHILLIPS COUNTIES...AS WELL AS EASTERN PORTIONS OF ADAMS...ARAPAHOE AND WELD COUNTIES. AND WITH TEMPERATURES AROUND 0C...GOOD BET THERE/S SOME FREEZING DRIZZLE AND FREEZING FOG OUT THERE. SO ROAD SURFCES MAY BE ICY IN AREAS. NO OTHER CHANGES TO THE FORECAST AT THIS TIME. PREV DISCUSSION... /ISSUED 503 AM MDT TUE OCT 29 2013/ SHORT TERM...ELONGATED UPPER LOW WILL MOVE SLOWLY NORTHEAST THROUGH TONIGHT...PUSHING AREAS OF LIFT OVER COLORADO. DURING THE DAY TODAY THERE WILL BE LIFT ASSOCIATED WITH A JET STREAK LIFTING OUT OF THE TROUGH. THIS IS MOVING OVER RATHER DRY MID LEVEL AIR...BUT IS HELPING WITH THE SHOWERS ON THE WESTERN COLORADO BORDER AT THIS TIME. OVERNIGHT TONIGHT THE BAROCLINIC BAND WILL SHIFT EASTWARD. MODELS INDICATE THAT THIS SHOULD BE DEVELOPING SOUTHWARD AS IT MOVES THROUGH...WHICH LOOKS GOOD. SHOWERS SHOULD BE MOVING INTO/DEVELOPING OVER THE MOUNTAINS THIS AFTERNOON...AND SOME OF THIS SHOULD SURVIVE ONTO THE PLAINS TONIGHT. A LITTLE COOLING WILL ACCOMPANY THIS...ENOUGH TO CHANGE PRECIP TO ALL SNOW IN THE MOUNTAINS. ON THE PLAINS WE HAVE OTHER ISSUES AS THE SATURATED COOL AIR IS NOT AS SHALLOW AS IT WAS SUPPOSED TO BE. IT GOT UP BETWEEN 9 AND 10 THOUSAND FEET ON THE EAST SLOPE OF THE FRONT RANGE. DESPITE THE STRONG SW WINDS ABOVE IT THERE IS NOT MUCH SIGN OF DISPLACEMENT...JUST A FEW HINTS OF WEST WINDS RIGHT AT THE TOP AROUND THE 9000 FOOT LEVEL. THE LOW LEVEL WINDS IN THE COOL AIR REMAIN NORTHEAST...INSTEAD OF BECOMING SOUTHEAST AS EXPECTED...AND THE MOISTURE HAS PUSHED FAR TO THE SOUTH...ALMOST TO OKLAHOMA. SO WHILE THERE IS DRY AIR AND WIND ABOVE THE CLOUDS...THERE IS NOT MUCH GOING ON AT LOW LEVELS TO CHANGE THE SITUATION. IN FACT...THE EASTERLY WINDS WILL LIKELY BE BRINGING IN WARMER BUT STILL SATURATED AIR WITH HIGHER DEW POINTS DURING THE DAY. THERE MAY YET BE SOME SCOURING FROM ABOVE BY THIS AFTERNOON...BUT THIS IS LOOKING PRETTY UNLIKELY IN AREAS ALONG AND NORTH OF INTERSTATE 76...AND QUESTIONABLE EVEN FURTHER SOUTH THOUGH THE ELEVATION OF THE PALMER DIVIDE MAY HELP. I DROPPED TEMPERATURES ABOUT 5 DEGREES IN MOST AREAS AND ADDED MORE DRIZZLE WHICH HAS BEEN FAIRLY WIDESPREAD THOUGH GENERALLY LIGHT. FOR TONIGHT ON THE PLAINS...IT SHOULD BE WARM ENOUGH FOR RAIN WITH ANY SHOWERS EARLY IN THE EVENING...AND PROBABLY STAY THAT WAY BUT WITH THE COOLING ALOFT AND POSSIBLY NOT BEING MUCH ABOVE FREEZING AT THE SURFACE TO BEGIN WITH THERE DOES APPEAR TO BE SOME CHANCE OF SNOW. WILL MENTION A MIX FOR NOW. LONG TERM...ON WEDNESDAY AT 12Z...MODELS HAVE THE UPPER LOW CENTERED OVER NORTHWESTERN WYOMING WITH THE UPPER TROUGH AXIS STRETCHING DOWN INTO BAJA CALIFORNIA. THE UPPER TROUGH AXIS IS PROGGED TO PUSH ACROSS THE FORECAST AREA WEDNESDAY NIGHT. IT IS OVER THE EASTERN COLORADO BORDER AT 12Z THURSDAY MORNING. NORTHWESTERLY FLOW ALOFT IS IN PLACE THE REST OF THURSDAY AND THURSDAY NIGHT. THERE IS UPWARD Q-G VERTICAL VELOCITY PROGGED OVER THE CWA WEDNESDAY INTO THE EVENING. AFTER 06Z...DOWNWARD MOTION IS PROGGED. BY THURSDAY AFTERNOON...THE SYNOPTIC SCALE ENERGY IS BENIGN. THE LOW LEVEL WINDS ARE PROGGED TO BE WEAK UPSLOPE ON WEDNESDAY AND WEDNESDAY EVENING. THEY BECOME DOWNSLOPING AFTER 06Z WEDNESDAY NIGHT AND CONTINUE THAT WAY THROUGH THURSDAY NIGHT. FOR MOISTURE...THERE IS SOME OVER THE PLAINS WEDNESDAY AND WEDNESDAY NIGHT....BUT MORE OVER THE MOUNTAINS AT THAT TIME. THINGS DRY OUT OVER MOST OF THE CWA THURSDAY...HOWEVER...THERE IS STILL SOME MOISTURE STICKING AROUND OVER THE HIGHER MOUNTAINS THURSDAY INTO FRIDAY MORNING. THERE QPF FIELDS DO SHOW SOME MEASURABLE PRECIPITATION AROUND THE CWA WEDNESDAY AND WEDNESDAY EVENING. MOST AREAS HAVE SOME...THE HIGHEST AMOUNTS OVER THE MOUNTAINS. THERE IS STILL LIMITED AMOUNTS PROGGED OVER THE MOUNTAINS THURSDAY AND THURSDAY NIGHT. WILL KEEP 30-60% POPS IN THE MOUNTAINS ALL FOUR PERIODS...AND 0-30%S OVER THE PLAINS FOR WEDNESDAY AND WEDNESDAY NIGHT. THE PLAINS WILL SEE RAIN FROM THE LATE MORNING HOURS INTO THE EARLY EVENING ON WEDNESDAY. SNOWFALL AMOUNTS SHOULD STAY UNDER ADVISORY CRITERIA. FOR TEMPERATURES...WEDNESDAY AND THURSDAY`S HIGHS LOOK CLOSE TO WHAT TODAY`S WILL BE. FOR THE LATER DAYS...FRIDAY THROUGH MONDAY...NORTHWESTERLY FLOW ALOFT WILL CONTINUE INTO FRIDAY NIGHT...THEN AN UPPER RIDGE WILL GET INTO COLORADO WITH ZONAL FLOW FOR THE CWA SATURDAY. ANOTHER UPPER TROUGH IS PROGGED INTO THE WESTERN UNITED STATES BY SATURDAY NIGHT. THE FLOW ALOFT BECOMES SOUTHWESTERLY SUNDAY AND SUNDAY NIGHT. BY MONDAY AFTERNOON...BOTH THE GFS AND ECMWF HAVE THE UPPER TROUGH AXIS OVER EASTERN UTAH/WESTERN COLORADO. THERE WILL STILL BE LIMITED MOISTURE IN THE MOUNTAINS FRIDAY WITH THE NORTHWESTERLY FLOW ALOFT. THEN IT WILL DRY EVERYWHERE THROUGH SUNDAY NIGHT...THEN SOME MOISTURE RETURNS TO THE WESTERN CWA MONDAY WITH THE UPPER TROUGH. AVIATION...IFR/LIFR CEILINGS WILL LIKELY LAST LONGER THAN PREVIOUSLY FORECAST...POSSIBLY INTO THE AFTERNOON. SOME IMPROVEMENT IS EXPECTED LATER IN THE DAY BUT MVFR CONDITIONS ARE STILL LIKELY...AND MVFR MAY LAST UNTIL THE TROUGH PASSES TONIGHT. ANY FREEZING DRIZZLE WILL BE VERY LIGHT...PRECIP TYPE EXPECTED TO BE MAINLY RAIN TONIGHT IN THE DENVER AREA. IF THERE IS SNOW THE THREAT OF ACCUMULATION ON RUNWAYS IS LESS THAN 10 PERCENT. && .BOU WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...SZOKE LONG TERM....RJK AVIATION...SZOKE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1231 PM CDT TUE OCT 29 2013 .DISCUSSION... 337 AM CDT MAIN FORECAST CONCERNS CONTINUE TO BE WITH RAIN POTENTIAL AND MILDER TEMPERATURES ASSOCIATED WITH A STRONG LOW PRESSURE SYSTEM WHICH WILL MOVE THROUGH THE UPPER MIDWEST WEDNESDAY NIGHT THROUGH THURSDAY. SHORT TERM...TODAY THROUGH THURSDAY... UPPER FLOW PATTERN THIS MORNING IS DOMINATED BY A LARGE CLOSED LOW OVER THE INTER-MOUNTAIN WEST...WITH SPLIT BUT MAINLY ZONAL FLOW DOWNSTREAM ACROSS THE EASTERN CONUS. OVERNIGHT WATER VAPOR IMAGERY DEPICTS A STRONG SHORT WAVE PROPAGATING ACROSS THE CENTRAL PLAINS AND INTO THE MID-MISSOURI VALLEY...ALONG A LOW LEVEL BAROCLINIC ZONE ASSOCIATED WITH A STATIONARY SURFACE FRONT WHICH STRETCHES WEST-EAST FROM KANSAS TO THE OHIO VALLEY. FARTHER NORTH...AN ELONGATED AREA OF SURFACE HIGH PRESSURE STRETCHED FROM NEAR LAKE WINNIPEG ACROSS THE NORTHERN GREAT LAKES TO NEW ENGLAND. THE PLAINS SHORT WAVE WILL CONTINUE TO TRACK EASTWARD ALONG THE BAROCLINIC ZONE TODAY...WITH WARM ADVECTION/ISENTROPIC UPGLIDE DEVELOPING ACROSS THE REGION. THE FOCUS FOR STRONGER FORCING AND LOW LEVEL MOISTURE RETURN WILL REMAIN ACROSS FAR SOUTHERN IA/MISSOURI AND DOWNSTATE ILLINOIS THROUGH THIS AFTERNOON HOWEVER...WITH MAINLY JUST MID/HIGH CLOUDINESS EXPECTED ACROSS THE CWA AS LOW LEVEL FLOW BACKS MORE SOUTHEAST. THIS WILL PULL IN DRIER AIR FROM UPSTREAM... AS NOTED IN LAST EVENINGS 00Z SOUNDING FROM WILMINGTON OH. SOME POTENTIAL PROBABLY EXISTS FOR A SPRINKLE OR TWO FROM OUR DEVELOPING MID-DECK LATER TODAY...THOUGH IT APPEARS THAT ORGANIZED MEASURABLE PRECIP CHANCES WILL REMAIN PRETTY LOW WITH THE SUITE OF GUIDANCE NOT PRODUCING QPF. IT DOES APPEAR THAT PRECIP CHANCES WILL INCREASE SLOWLY FROM THE SOUTH TONIGHT...AS THE ELEVATED BAROCLINIC ZONE LIFTS SLOWLY NORTH IN RESPONSE TO PERSISTENT WARM ADVECTION ON SOUTH-SOUTHWEST WINDS. OTHER THAN MOISTURE TRANSPORT/CONVERGENCE ALONG THE ELEVATED WARM FRONT ON THE NOSE OF A 20-25 KT LOW LEVEL JET TONIGHT...LITTLE IN THE WAY OF SHORT WAVE SUPPORT IS NOTED AND HEIGHTS ACTUALLY RISE A BIT WITH WEAK RIDGING DEVELOPING ALOFT. GUIDANCE DOES BRING SOME LIGHT QPF ACROSS THE SOUTHERN PORTIONS OF THE CWA OVERNIGHT...THOUGH HAVE GENERALLY LOWERED POPS SIGNIFICANTLY FROM PREVIOUS FORECAST BASED ON CURRENT GUIDANCE TRENDS. THE WESTERN TROUGH BEGINS TO OPEN UP AND MOVE EAST WEDNESDAY AND WEDNESDAY NIGHT...WITH RENEWED SURFACE LOW PRESSURE DEVELOPMENT ACROSS THE CENTRAL PLAINS. THE LOW WILL LIFT ACROSS THE MID-MISSOURI VALLEY BY WEDNESDAY EVENING AND INTO THE UPPER MISSISSIPPI VALLEY BY THURSDAY MORNING...WITH SEVERAL MODELS DEPICTING A SHORT WAVE APPROACHING THE CWA WEDNESDAY AFTERNOON/EVENING. A MUCH STRONGER 40-50 KT 850 MB JET IS INDICATED WEDNESDAY NIGHT WHICH IMPINGES ON THE WARM FRONTAL ZONE AS IT LIFTS NORTH...SUGGESTING RAPIDLY INCREASING POTENTIAL FOR RAIN AND A FEW THUNDERSTORMS BY LATE WEDNESDAY AND CONTINUING INTO THURSDAY IN THE WARM SECTOR AHEAD OF THE APPROACHING COLD FRONT. STRONG MOISTURE ADVECTION...PWATS APPROACHING 1.5 INCHES...AND SURFACE DEW POINT TEMPS IN THE UPPER 50S...SUPPORT FAIRLY HIGH POPS DURING THIS PERIOD. AS FOR TEMPERATURES...INCREASING CLOUD COVER AND EAST-SOUTHEAST LOW LEVEL WINDS ARE EXPECTED TO KEEP RISES IN CHECK DESPITE WARMING ALOFT TODAY. WARMER TEMPS...IN THE 60S...WILL SPREAD NORTH WITH THE WARM FRONT INTO THE SOUTHERN CWA WEDNESDAY AND ACROSS THE ENTIRE AREA THURSDAY. RISING TEMPS ARE LIKELY WEDNESDAY NIGHT. LONG TERM...FRIDAY-MONDAY... THE LARGE SCALE UPPER TROUGH WILL LINGER ACROSS THE REGION FRIDAY AND SATURDAY AS ADDITIONAL SHORT WAVE ENERGY DIGS IN FROM THE NORTHWEST. COOL ADVECTION AND CYCLONIC LOW LEVEL FLOW IN SURFACE TROUGHING OVER THE LAKES WILL LIKELY SUPPORT CONSIDERABLE CLOUD COVER INITIALLY...WITH THE POTENTIAL FOR SOME SPRINKLES/SHOWERS ESPECIALLY FRIDAY NIGHT AND SATURDAY WITH A SECONDARY PUSH OF COLDER AIR. SURFACE HIGH PRESSURE THEN EVENTUALLY SPREADS ACROSS THE REGION LATE SATURDAY NIGHT AND SUNDAY. LONG RANGE MODEL SOLUTIONS MOVE THE HIGH QUICKLY OFF TO THE EAST SUNDAY NIGHT...WITH ANOTHER LOW PASSING NORTHWEST OF THE FORECAST AREA MONDAY. THIS SETS UP ANOTHER PERIOD OF SOUTH FLOW AND A RETURN OF RAIN CHANCES ESPECIALLY WEST ON MONDAY. TEMPS COOL TO THE UPPER 40S/LOW 50S OVER THE WEEKEND BEFORE MODERATING MONDAY. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * WINDS SOMEWHAT VARIABLE IN DIRECTION BETWEEN ENE TO SSE. * LOWERING CIG TREND...WITH MVFR LIKELY SOMETIME WEDNESDAY. BMD //DISCUSSION...UPDATED 18Z... EXPECT FAIRLY STEADY STATE CONDITIONS THROUGH THE REST OF TODAY AND MOST OF TONIGHT...WITH ONLY SOME MINOR UNDULATIONS IN THE EASTERLY FLOW. LOW PRESSURE WILL CONTINUE TO DEEPEN AND MOVE NORTHEAST ACROSS THE CENTRAL PLAINS TODAY...WITH A WARM FRONT MOVING INTO CENTRAL ILLINOIS OVERNIGHT. WARM ADVECTION/ISENTROPIC ASCENT WILL HELP TO SATURATE THE COLUMN GRADUALLY THROUGH THE PERIOD WITH DRY LOW LEVEL EASTERLIES HELPING TO HOLD OFF PRECIPITATION. CIGS ARE EXPECTED TO BUILD DOWN TO MVFR SOMETIME WEDNESDAY MORNING...THOUGH TIMING IS A BIT UNCERTAIN...AS SOME MODELS HOLD OFF MVFR UNTIL LATE IN THE MORNING. DESPITE THE PERSISTENT ALBEIT WEAK LOW LEVEL FORCING... MID/UPPER LEVEL FORCING IS ABSENT AS UPPER RIDGE BUILDS ACROSS THE REGION WITH PERSISTENT HEIGHT RISES THROUGH MID EVENING. THAT SAID...A LEAD SHORTWAVE TROUGH WILL EJECT EAST RIDING UP THE RIDGE OVER THE AREA WEDNESDAY AFTERNOON AND WILL LEAD TO THE BEST CHANCE FOR PRECIP WITHIN THE CURRENT TAF PERIOD. SOME OF THE MODELS DEVELOP LIGHT PRECIP OVER THE AREA...AND CONVECTIVE ALLOWING MODELS HINT AT A FEW SCATTERED SHOWERS. FOR NOW WILL INCLUDE VCSH IN THE AFTERNOON...BUT IMPACTS AT THE TERMINALS ARE PRETTY UNLIKELY...AND A VCSH MIGHT EVEN BE A STRETCH. IF CIGS BUILD DOWN LOWER THAN EXPECTED...THEN DRIZZLE MAY END UP BEING MORE OF A CONCERN TOMORROW AFTERNOON. BMD //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION/SPEED. * HIGH CONFIDENCE IN GENERAL CIG TRENDS...LOW-MEDIUM CONFIDENCE IN TIMING CATEGORY CHANGE. * LOW CONFIDENCE IN PRECIP IMPACTING TERMINALS WEDNESDAY. BMD //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... WEDNESDAY NIGHT...SHRA W/ CHANCE OF TSRA. THURSDAY...SHRA W/ CHANCE OF TSRA. FRIDAY...CHANCE OF SHRA EARLY...OTHERWISE VFR. SATURDAY...CHANCE OF SHRA...OTHERWISE VFR. SUNDAY...VFR. MONDAY...SLIGHT CHANCE OF SHRA...OTHERWISE VFR. RODRIGUEZ && .MARINE... 418 AM CDT MAIN FORECAST CONCERN IS WITH A SYSTEM TO APPROACH THE GREAT LAKES REGION WEDNESDAY NIGHT INTO THURSDAY...WITH GALE FORCE GUSTS TO 35 KT POSSIBLE ACROSS THE WHOLE LAKE DURING THIS PERIOD. THE CENTER OF LARGE HIGH PRESSURE SPANNING SOUTHERN CANADA AND THE UPPER MIDWEST WILL SHIFT SOUTHEAST THROUGH THE GREAT LAKES REGION TO THE ATLANTIC COAST TODAY...WHILE A TROUGH OF LOW PRESSURE OVER THE SOUTHERN PLAINS REMAINS SITUATED. AS THIS OCCURS...EXPECT EAST WINDS TO DIMINISH TO 10 TO 15 KT WHILE TURNING TO THE SOUTHEAST TODAY AND TONIGHT. DESPITE THIS TROUGH OF LOW PRESSURE DEEPENING AS IT SLOWLY LIFTS NORTHEAST THROUGH THE CENTRAL PLAINS TONIGHT INTO WEDNESDAY...A FAIRLY RELAXED GRADIENT OVER THE LAKE WILL HELP LIGHT SOUTHEAST WINDS TO PERSIST DURING THE DAY WEDNESDAY. ALTHOUGH THIS LOW WILL CONTINUE DEEPENING AS IT LIFTS TO THE UPPER MIDWEST WEDNESDAY NIGHT AND AS THIS OCCURS...EXPECT THESE SOUTHEAST WINDS TO BECOME SOUTH AND INCREASE TO 30KT. ONCE AGAIN...ITS DURING THE WEDNESDAY NIGHT AND THURSDAY TIME FRAME WHEN GALE FORCE GUSTS ARE POSSIBLE. WILL NEED TO MONITOR THIS TIME FRAME AND IF INCREASING TRENDS OCCUR OVER THE NEXT FORECAST RUNS...POSSIBLE GALES WILL NOT BE OUT OF THE QUESTION. THIS LOW WILL MOVE EAST INTO SOUTHEAST ONTARIO AND QUEBEC THURSDAY NIGHT INTO FRIDAY BEFORE EXITING TO THE NORTHEAST FRIDAY NIGHT. EXPECT SOUTHWEST WINDS TO BECOME WEST STILL HOLDING AT 30 KT THROUGH EARLY FRIDAY...BEFORE DIMINISHING LATER THAT DAY. RODRIGUEZ && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 3 PM TUESDAY. && $$ 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 1216 PM CDT Tue Oct 29 2013 .DISCUSSION... ISSUED 955 AM CDT Tue Oct 29 2013 Large rain shield advancing eastward across Missouri, but the eastern edge is being chewed up by the dry air that is currently in place over Illinois. Initial radar returns will go toward moistening up the column from the top down, so it will probably be toward early afternoon before any steadier rains arrive in our forecast area, and then it will be most likely south of I-72. Have left slight chance PoP`s in across the northeast third of the CWA for now, although latest guidance from the NAM/RAP/HRRR models is indicating that any rain today will likely remain to the south, and would probably hold off until mid or late afternoon if it does manage to get that far north. Have sent some updated zones/grids to freshen up the temperature and rain trends, although no significant changes were made. Geelhart && .AVIATION... ISSUED 1215 PM CDT Tue Oct 29 2013 Incoming rain shield has been eroding on the leading edge due to the dry air currently in place, so will continue to limit any rain mention to VCSH at KPIA/KSPI and keep eastern TAFs dry for now. Main concern will be tonight, as ceilings lower below 3000 feet this evening from south to north, then are likely to drop to IFR range after 06Z, with the highest chances of this occurring at KSPI and KPIA. Drier air aloft will limit overnight precip chances to mainly some drizzle or very light showers. Ceilings should begin to come up Wednesday morning as a warm front lifts northward through central Illinois. Will maintain MVFR ceilings through the morning, although areas from KSPI-KCMI may see them lift above 3000 feet by late morning. Geelhart && .PREV DISCUSSION... ISSUED 254 AM CDT Tue Oct 29 2013 Main challenges with this forecast package are rain chances today through Thursday and the potential for severe weather Thursday afternoon. Current upper air pattern features the main branch of the polar jet flowing well to the north across central and eastern Canada. Further southwest, a deep closed low has become cut-off from the flow and is now meandering eastward across the Great Basin. This low will be the dominant weather-maker across central Illinois for the next several days as it slowly makes its way eastward. SHORT TERM...Today through Thursday Weak frontal boundary that dropped into the area yesterday afternoon has now become stationary just north of the Ohio River. To the north of the front, a dry E/NE flow prevails across central Illinois early this morning, with 07z/2am dewpoints mainly in the 30s. This dry airmass will inhibit the eastward spread of precip currently developing ahead of a weak short-wave trough over the Plains. The onset of precip has been gradually delayed with each model run over the past couple of days, with the 00z Oct 29 suite now keeping the KILX CWA dry until afternoon. HRRR suggests light showers may arrive in the Winchester/Jacksonville area around midday, then will spread eastward to the Indiana border toward evening. Will therefore go with a dry forecast this morning, then will focus highest POPs across the southern CWA in closer proximity to the stalled front this afternoon. Further north toward the I-74 corridor, little or no precip is expected today. Once this initial wave passes, short-wave ridging in its wake will keep rain chances low tonight. Despite lack of upper forcing, moistening airmass and presence of surface boundary support low chance POPs through the night. As Great Basin upper low begins to approach from the west, surface front will get nudged northward on Wednesday. Thanks to southerly winds south of the boundary, afternoon high temperatures will rise into the upper 60s and lower 70s. In addition, showers and thunderstorms will become more widespread during the afternoon, particularly along/west of the Illinois River. Main rain/convective event is still slated for Wednesday night into Thursday as strong cold front approaches from the west. Models are generally in good agreement with their mass fields, but still have some minor differences in QPF. As boundary nears, copious amounts of moisture will advect northward from the Gulf of Mexico, with precipitable water values nearing 1.50 on Thursday. Given ample moisture, strong upper dynamics, and presence of approaching cold front, will carry likely to categorical POPs across the board Wednesday night and Thursday. Total rainfall with this system will generally range from 1 to 1.50, with isolated higher amounts within stronger storms. Strong to potentially severe thunderstorms will be possible Thursday afternoon as the front swings through the region: however, details remain uncertain at this point. NAM/GFS forecast soundings indicate a low CAPE/high shear environment in the warm sector ahead of the front, with the greatest instability focused further southeast from the Ohio River Valley to the western Gulf Coast. Latest DAY 3 convective outlook from SPC highlights this area for potential severe, but can not rule out a few strong storms with damaging wind gusts further north across east-central and southeast Illinois, particularly given impressive 0-6km bulk shear values of 70 to 75kt. LONG TERM...Friday through Monday Cooler and drier weather will return by the end of the week, as upper trough digs across the Great Lakes. GFS/ECMWF both suggest clouds and a few showers will be possible across northeast Illinois into north-central Indiana Friday into Saturday: however, think these will remain northeast of central Illinois. High pressure building into the Midwest will be the dominant weather feature in the extended, resulting in cool highs in the 50s Friday through Monday. Next chance for rain will likely hold off until Tuesday when another system approaches from the west. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1104 AM CDT TUE OCT 29 2013 .DISCUSSION... 337 AM CDT MAIN FORECAST CONCERNS CONTINUE TO BE WITH RAIN POTENTIAL AND MILDER TEMPERATURES ASSOCIATED WITH A STRONG LOW PRESSURE SYSTEM WHICH WILL MOVE THROUGH THE UPPER MIDWEST WEDNESDAY NIGHT THROUGH THURSDAY. SHORT TERM...TODAY THROUGH THURSDAY... UPPER FLOW PATTERN THIS MORNING IS DOMINATED BY A LARGE CLOSED LOW OVER THE INTER-MOUNTAIN WEST...WITH SPLIT BUT MAINLY ZONAL FLOW DOWNSTREAM ACROSS THE EASTERN CONUS. OVERNIGHT WATER VAPOR IMAGERY DEPICTS A STRONG SHORT WAVE PROPAGATING ACROSS THE CENTRAL PLAINS AND INTO THE MID-MISSOURI VALLEY...ALONG A LOW LEVEL BAROCLINIC ZONE ASSOCIATED WITH A STATIONARY SURFACE FRONT WHICH STRETCHES WEST-EAST FROM KANSAS TO THE OHIO VALLEY. FARTHER NORTH...AN ELONGATED AREA OF SURFACE HIGH PRESSURE STRETCHED FROM NEAR LAKE WINNIPEG ACROSS THE NORTHERN GREAT LAKES TO NEW ENGLAND. THE PLAINS SHORT WAVE WILL CONTINUE TO TRACK EASTWARD ALONG THE BAROCLINIC ZONE TODAY...WITH WARM ADVECTION/ISENTROPIC UPGLIDE DEVELOPING ACROSS THE REGION. THE FOCUS FOR STRONGER FORCING AND LOW LEVEL MOISTURE RETURN WILL REMAIN ACROSS FAR SOUTHERN IA/MISSOURI AND DOWNSTATE ILLINOIS THROUGH THIS AFTERNOON HOWEVER...WITH MAINLY JUST MID/HIGH CLOUDINESS EXPECTED ACROSS THE CWA AS LOW LEVEL FLOW BACKS MORE SOUTHEAST. THIS WILL PULL IN DRIER AIR FROM UPSTREAM... AS NOTED IN LAST EVENINGS 00Z SOUNDING FROM WILMINGTON OH. SOME POTENTIAL PROBABLY EXISTS FOR A SPRINKLE OR TWO FROM OUR DEVELOPING MID-DECK LATER TODAY...THOUGH IT APPEARS THAT ORGANIZED MEASURABLE PRECIP CHANCES WILL REMAIN PRETTY LOW WITH THE SUITE OF GUIDANCE NOT PRODUCING QPF. IT DOES APPEAR THAT PRECIP CHANCES WILL INCREASE SLOWLY FROM THE SOUTH TONIGHT...AS THE ELEVATED BAROCLINIC ZONE LIFTS SLOWLY NORTH IN RESPONSE TO PERSISTENT WARM ADVECTION ON SOUTH-SOUTHWEST WINDS. OTHER THAN MOISTURE TRANSPORT/CONVERGENCE ALONG THE ELEVATED WARM FRONT ON THE NOSE OF A 20-25 KT LOW LEVEL JET TONIGHT...LITTLE IN THE WAY OF SHORT WAVE SUPPORT IS NOTED AND HEIGHTS ACTUALLY RISE A BIT WITH WEAK RIDGING DEVELOPING ALOFT. GUIDANCE DOES BRING SOME LIGHT QPF ACROSS THE SOUTHERN PORTIONS OF THE CWA OVERNIGHT...THOUGH HAVE GENERALLY LOWERED POPS SIGNIFICANTLY FROM PREVIOUS FORECAST BASED ON CURRENT GUIDANCE TRENDS. THE WESTERN TROUGH BEGINS TO OPEN UP AND MOVE EAST WEDNESDAY AND WEDNESDAY NIGHT...WITH RENEWED SURFACE LOW PRESSURE DEVELOPMENT ACROSS THE CENTRAL PLAINS. THE LOW WILL LIFT ACROSS THE MID-MISSOURI VALLEY BY WEDNESDAY EVENING AND INTO THE UPPER MISSISSIPPI VALLEY BY THURSDAY MORNING...WITH SEVERAL MODELS DEPICTING A SHORT WAVE APPROACHING THE CWA WEDNESDAY AFTERNOON/EVENING. A MUCH STRONGER 40-50 KT 850 MB JET IS INDICATED WEDNESDAY NIGHT WHICH IMPINGES ON THE WARM FRONTAL ZONE AS IT LIFTS NORTH...SUGGESTING RAPIDLY INCREASING POTENTIAL FOR RAIN AND A FEW THUNDERSTORMS BY LATE WEDNESDAY AND CONTINUING INTO THURSDAY IN THE WARM SECTOR AHEAD OF THE APPROACHING COLD FRONT. STRONG MOISTURE ADVECTION...PWATS APPROACHING 1.5 INCHES...AND SURFACE DEW POINT TEMPS IN THE UPPER 50S...SUPPORT FAIRLY HIGH POPS DURING THIS PERIOD. AS FOR TEMPERATURES...INCREASING CLOUD COVER AND EAST-SOUTHEAST LOW LEVEL WINDS ARE EXPECTED TO KEEP RISES IN CHECK DESPITE WARMING ALOFT TODAY. WARMER TEMPS...IN THE 60S...WILL SPREAD NORTH WITH THE WARM FRONT INTO THE SOUTHERN CWA WEDNESDAY AND ACROSS THE ENTIRE AREA THURSDAY. RISING TEMPS ARE LIKELY WEDNESDAY NIGHT. LONG TERM...FRIDAY-MONDAY... THE LARGE SCALE UPPER TROUGH WILL LINGER ACROSS THE REGION FRIDAY AND SATURDAY AS ADDITIONAL SHORT WAVE ENERGY DIGS IN FROM THE NORTHWEST. COOL ADVECTION AND CYCLONIC LOW LEVEL FLOW IN SURFACE TROUGHING OVER THE LAKES WILL LIKELY SUPPORT CONSIDERABLE CLOUD COVER INITIALLY...WITH THE POTENTIAL FOR SOME SPRINKLES/SHOWERS ESPECIALLY FRIDAY NIGHT AND SATURDAY WITH A SECONDARY PUSH OF COLDER AIR. SURFACE HIGH PRESSURE THEN EVENTUALLY SPREADS ACROSS THE REGION LATE SATURDAY NIGHT AND SUNDAY. LONG RANGE MODEL SOLUTIONS MOVE THE HIGH QUICKLY OFF TO THE EAST SUNDAY NIGHT...WITH ANOTHER LOW PASSING NORTHWEST OF THE FORECAST AREA MONDAY. THIS SETS UP ANOTHER PERIOD OF SOUTH FLOW AND A RETURN OF RAIN CHANCES ESPECIALLY WEST ON MONDAY. TEMPS COOL TO THE UPPER 40S/LOW 50S OVER THE WEEKEND BEFORE MODERATING MONDAY. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * MVFR CONDITIONS RETURN EARLY WEDNESDAY MORNING. * -SHRA MOVING NEAR THE TERMINALS TONIGHT. RODRIGUEZ/BMD //DISCUSSION...UPDATED 12Z... MVFR STRATUS PERSISTING PRIMARILY OVER ORD EARLY THIS MORNING...WITH ORD BEING IN A FAVORABLE AXIS FOR PERSISTENT DEVELOPMENT. THESE CONDITIONS WILL REMAIN OVER THE NEXT 2-3 HOURS BEFORE THESE CEILINGS LIFT NORTH OF THE TERMINALS. SHOULD ONLY AFFECT ORD...BUT COULD COME CLOSE TO DPA AS THIS LIFTS NORTHWARD. CEILINGS ARE CURRENTLY HOLDING AT 1500FT...WITH THEM NOT ANTICIPATED TO LOWER ANY FURTHER. WITH THE DEPARTURE OF THIS LOW STRATUS...ONLY MID/HIGH LEVEL CLOUD COVER EXPECTED TODAY INTO TONIGHT AS MOISTURE STREAMS OUT AHEAD OF AN APPROACHING SYSTEM TO THE WEST. SEVERAL MID LEVEL DISTURBANCES WILL MOVE ACROSS THE REGION THIS EVENING WITH THE LEADING EDGE OF THE CURRENT PRECIP SHIELD OVER THE CENTRAL PLAINS WORKING ITS WAY TOWARDS THE TERMINALS TONIGHT. ALTHOUGH OUTSIDE OF SOME SCT LIGHT SHOWERS NEAR RFD...IT DOES APPEAR AS IF BETTER FORCING WILL REMAIN TO THE SOUTH OF THE TERMINALS AND LIKEWISE PRECIP AXIS. ALTHOUGH FURTHER SATURATION IS EXPECTED OVERNIGHT INTO EARLY WEDNESDAY MORNING WITH CEILINGS LOWERING...AND MVFR CONDITIONS ONCE AGAIN RETURNING OVER THE TERMINALS. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH CONFIDENCE WITH CEILINGS/TRENDS TODAY...MEDIUM CONFIDENCE EARLY WEDNESDAY MORNING. * HIGH CONFIDENCE WITH WIND DIRECTION...LOW CONFIDENCE IN GUSTS. * LOW MEDIUM CONFIDENCE WITH -SHRA/TRENDS TONIGHT. RODRIGUEZ/BMD //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... WEDNESDAY NIGHT...SHRA W/ CHANCE OF TSRA. THURSDAY...SHRA W/ CHANCE OF TSRA. FRIDAY...CHANCE OF SHRA EARLY...OTHERWISE VFR. SATURDAY...CHANCE OF SHRA...OTHERWISE VFR. SUNDAY...VFR. MONDAY...SLIGHT CHANCE OF SHRA...OTHERWISE VFR. RODRIGUEZ && .MARINE... 418 AM CDT MAIN FORECAST CONCERN IS WITH A SYSTEM TO APPROACH THE GREAT LAKES REGION WEDNESDAY NIGHT INTO THURSDAY...WITH GALE FORCE GUSTS TO 35 KT POSSIBLE ACROSS THE WHOLE LAKE DURING THIS PERIOD. THE CENTER OF LARGE HIGH PRESSURE SPANNING SOUTHERN CANADA AND THE UPPER MIDWEST WILL SHIFT SOUTHEAST THROUGH THE GREAT LAKES REGION TO THE ATLANTIC COAST TODAY...WHILE A TROUGH OF LOW PRESSURE OVER THE SOUTHERN PLAINS REMAINS SITUATED. AS THIS OCCURS...EXPECT EAST WINDS TO DIMINISH TO 10 TO 15 KT WHILE TURNING TO THE SOUTHEAST TODAY AND TONIGHT. DESPITE THIS TROUGH OF LOW PRESSURE DEEPENING AS IT SLOWLY LIFTS NORTHEAST THROUGH THE CENTRAL PLAINS TONIGHT INTO WEDNESDAY...A FAIRLY RELAXED GRADIENT OVER THE LAKE WILL HELP LIGHT SOUTHEAST WINDS TO PERSIST DURING THE DAY WEDNESDAY. ALTHOUGH THIS LOW WILL CONTINUE DEEPENING AS IT LIFTS TO THE UPPER MIDWEST WEDNESDAY NIGHT AND AS THIS OCCURS...EXPECT THESE SOUTHEAST WINDS TO BECOME SOUTH AND INCREASE TO 30KT. ONCE AGAIN...ITS DURING THE WEDNESDAY NIGHT AND THURSDAY TIME FRAME WHEN GALE FORCE GUSTS ARE POSSIBLE. WILL NEED TO MONITOR THIS TIME FRAME AND IF INCREASING TRENDS OCCUR OVER THE NEXT FORECAST RUNS...POSSIBLE GALES WILL NOT BE OUT OF THE QUESTION. THIS LOW WILL MOVE EAST INTO SOUTHEAST ONTARIO AND QUEBEC THURSDAY NIGHT INTO FRIDAY BEFORE EXITING TO THE NORTHEAST FRIDAY NIGHT. EXPECT SOUTHWEST WINDS TO BECOME WEST STILL HOLDING AT 30 KT THROUGH EARLY FRIDAY...BEFORE DIMINISHING LATER THAT DAY. RODRIGUEZ && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 3 PM TUESDAY. && $$ 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 956 AM CDT Tue Oct 29 2013 .DISCUSSION... ISSUED 955 AM CDT Tue Oct 29 2013 Large rain shield advancing eastward across Missouri, but the eastern edge is being chewed up by the dry air that is currently in place over Illinois. Initial radar returns will go toward moistening up the column from the top down, so it will probably be toward early afternoon before any steadier rains arrive in our forecast area, and then it will be most likely south of I-72. Have left slight chance PoP`s in across the northeast third of the CWA for now, although latest guidance from the NAM/RAP/HRRR models is indicating that any rain today will likely remain to the south, and would probably hold off until mid or late afternoon if it does manage to get that far north. Have sent some updated zones/grids to freshen up the temperature and rain trends, although no significant changes were made. Geelhart && .AVIATION... ISSUED 600 AM CDT Tue Oct 29 2013 VFR conditions into the afternoon hours, then timing of the MVFR/IFR cigs late this afternoon across the west and over the remainder of the area tonight will be the main forecast challenge. Band of showers over Missouri expected to weaken as it pushes east into a drier air mass today. None the less, we do expect some light shower activity to make it at least into the SPI and DEC in the 15z-18z time frame. Forecast soundings continue to hold with mainly VFR cigs despite the rain but feel with a persistent moistening occurring at the mid and low levels of the atmosphere over the next 12 to 18 hours...we should see deteriorating conditions with respect to cigs and vsbys...and that would be especially true for all areas tonight. Surface winds will be southeast at 10 to 15 kts today and tonight. Smith && .PREV DISCUSSION... ISSUED 254 AM CDT Tue Oct 29 2013 Main challenges with this forecast package are rain chances today through Thursday and the potential for severe weather Thursday afternoon. Current upper air pattern features the main branch of the polar jet flowing well to the north across central and eastern Canada. Further southwest, a deep closed low has become cut-off from the flow and is now meandering eastward across the Great Basin. This low will be the dominant weather-maker across central Illinois for the next several days as it slowly makes its way eastward. SHORT TERM...Today through Thursday Weak frontal boundary that dropped into the area yesterday afternoon has now become stationary just north of the Ohio River. To the north of the front, a dry E/NE flow prevails across central Illinois early this morning, with 07z/2am dewpoints mainly in the 30s. This dry airmass will inhibit the eastward spread of precip currently developing ahead of a weak short-wave trough over the Plains. The onset of precip has been gradually delayed with each model run over the past couple of days, with the 00z Oct 29 suite now keeping the KILX CWA dry until afternoon. HRRR suggests light showers may arrive in the Winchester/Jacksonville area around midday, then will spread eastward to the Indiana border toward evening. Will therefore go with a dry forecast this morning, then will focus highest POPs across the southern CWA in closer proximity to the stalled front this afternoon. Further north toward the I-74 corridor, little or no precip is expected today. Once this initial wave passes, short-wave ridging in its wake will keep rain chances low tonight. Despite lack of upper forcing, moistening airmass and presence of surface boundary support low chance POPs through the night. As Great Basin upper low begins to approach from the west, surface front will get nudged northward on Wednesday. Thanks to southerly winds south of the boundary, afternoon high temperatures will rise into the upper 60s and lower 70s. In addition, showers and thunderstorms will become more widespread during the afternoon, particularly along/west of the Illinois River. Main rain/convective event is still slated for Wednesday night into Thursday as strong cold front approaches from the west. Models are generally in good agreement with their mass fields, but still have some minor differences in QPF. As boundary nears, copious amounts of moisture will advect northward from the Gulf of Mexico, with precipitable water values nearing 1.50 on Thursday. Given ample moisture, strong upper dynamics, and presence of approaching cold front, will carry likely to categorical POPs across the board Wednesday night and Thursday. Total rainfall with this system will generally range from 1 to 1.50, with isolated higher amounts within stronger storms. Strong to potentially severe thunderstorms will be possible Thursday afternoon as the front swings through the region: however, details remain uncertain at this point. NAM/GFS forecast soundings indicate a low CAPE/high shear environment in the warm sector ahead of the front, with the greatest instability focused further southeast from the Ohio River Valley to the western Gulf Coast. Latest DAY 3 convective outlook from SPC highlights this area for potential severe, but can not rule out a few strong storms with damaging wind gusts further north across east-central and southeast Illinois, particularly given impressive 0-6km bulk shear values of 70 to 75kt. LONG TERM...Friday through Monday Cooler and drier weather will return by the end of the week, as upper trough digs across the Great Lakes. GFS/ECMWF both suggest clouds and a few showers will be possible across northeast Illinois into north-central Indiana Friday into Saturday: however, think these will remain northeast of central Illinois. High pressure building into the Midwest will be the dominant weather feature in the extended, resulting in cool highs in the 50s Friday through Monday. Next chance for rain will likely hold off until Tuesday when another system approaches from the west. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
350 PM EDT TUE OCT 29 2013 .SYNOPSIS... HIGH PRESSURE WILL BUILD OVER THE AREA TONIGHT AND WILL MOVE EAST OF THE REGION ON THURSDAY. LOW PRESSURE WILL APPROACH LATE THURSDAY AND LIFT NORTH OF THE STATE THURSDAY NIGHT INTO FRIDAY. && .NEAR TERM /THROUGH WEDNESDAY/... MAJOR CHALLENGE WILL BE THE CLOUDS ACROSS THE NORTHERN 3RD OF THE CAW AND TEMPERATURES. 19Z VISIBLE SATL IMAGERY AND METARS SHOWED THE THICKEST CLOUD COVER ACROSS THE N AND W. FURTHER S AND E, MOSTLY CLEAR SKIES. THE LATEST 19Z LAPS/RAP SOUNDINGS SHOWED LLVL MOISTURE TRAPPED BELOW 850 MBS W/DRY AIR ALOFT. CLOUDS ACROSS THE NORTH AND WEST WILL DISSIPATE LATER THIS EVENING AS DRIER AIR WORKS ITS WAY THROUGH THE COLUMN AS SHOWN BY THE RAP BY 03Z LEADING TO CLEARING AND WINDS DECOUPLING. A S/WV SHOWING IN THE UPPER LEVELS IS FCST TO MOVE ACROSS CENTRAL AND SOUTHERN MAINE LATER TONIGHT INTO WEDNESDAY. MOST OF THE MOISTURE ASSOCIATED W/THIS FEATURE IS FROM 700-500MBS AND THIS WILL BE MOST PROMINENT ACROSS THE DOWNEAST AND COASTAL AREAS. THIS WILL AID IN CAPPING TEMPERATURES OVERNIGHT BY 06Z WHILE TEMPERATURES FURTHER N AND W WILL DROP OFF SIGNIFICANTLY DUE TO THE CLEAR SKIES AND WINDS DROPPING OFF BELOW 6 MPH. TEMPERATURES BY EARLY WEDNESDAY MORNING ARE FCST TO BE IN THE UPPER TEENS TO AROUND 20 ACROSS THE N AND W WHILE LOW TO MID 20S WILL BE COMMON IN THE CENTRAL AND DOWNEAST REGION. THE COAST WILL BE A TAD WARMER AS HIGH CLOUDS MOVE IN W/EXPECTED OVERNIGHT LOWS IN THE UPPER 20S. IN REGARDS TO THE S/WV MENTIONED ABV, THE LATEST RAP AND NAM INDICATED SOME WEAK MID LEVEL FORCING W/SOME LIGHT PRECIP EDGING THE COAST AND OFFSHORE WATERS. THE 12Z GFS AND GEM SHOWS THIS TO SOME EXTENT. THE 12Z UA DID SHOW A 30-35KT JETLET AT 700MBS ASSOCIATED W/THIS FEATURE AND THEREFORE ADDED 20-30% FOR LIGHT RAIN SHOWERS BY WEDNESDAY MORNING INTO EARLY AFTERNOON FOR THE IMMEDIATE COAST. THERE IS SOME CONCERN THAT THERE COULD BE SOME SPOTTY LIGHT FREEZING PRECIP BUT ATTM CONFIDENCE TO LOW ON THIS AND DECIDED TO KEEP THE WX ELEMENT AS SHOWERS W/THE BULK OF THE PRECIP ARRIVING NEAR OR AFTER 12Z W/TEMPERATURES WARMING. DUE TO DEWPOINTS BEING IN THE UPPER TEENS AND LOWER 20S, WOULD NOT BE SURPRISED IF SOME BRIEF FLAKES OR EVEN SLEET OCCURS AT THE ONSET OF ANY PRECIP. THE EVENING CREW CAN ASSESS THIS FURTHER TONIGHT. SKIES ARE EXPECTED TO BECOME AT LEAST PARTLY SUNNY AND TEMPERATURES ARE FCST TO WARM WELL INTO THE 30S ACROSS THE N AND W AND MID TO UPPER 40S CENTRAL AND DOWNEAST. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... INTENSE LOW PRESSURE MOVES INTO THE GREAT LAKES THEN INTO QUEBEC PROVINCE FRIDAY. AT THE SAME TIME STRONG HIGH PRESSURE WILL MOVE EAST INTO THE ATLANTIC DURING THE DAY THURSDAY. WILL USE A BLEND OF THE NAM12..GFS40..SREF AND ECMWF FOR POPS AND QPF. FOR TEMPERATURE WILL USE THE CONSENSUS RAW BLEND. FOR WINDS HAVE USED THE MOSG25. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... A STRONG COLD FRONT BEHIND THIS SYSTEM WILL MOVE THROUGH THE REGION FRIDAY NIGHT INTO SATURDAY. LOW PRESSURE IS EXPECTED TO DEVELOP ALONG THIS COLD FRONT SOUTH OF NEW ENGLAND LATE SATURDAY THEN MOVE TO THE NORTHEAST. STRONG HIGH PRESSURE WILL BUILD IN FROM THE WEST SUNDAY THEN CREST OVER THE REGION MONDAY. HAVE USED THE SUPPER BLEND TO INITIALIZE ALL GRIDS. WILL ADJUST WIND GUSTS USING 150 PERCENT OF THE SUSTAINED WIND SPEED. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... NEAR TERM: A BRIEF PERIOD OF MVFR FOR FAR NORTHERN TERMINALS SUCH AS KCAR/KFVE AND KPQI THIS EVENING AND THEN VFR. FROM KHUL TO KBHB, IT LOOKS LIKE VFR RIGHT INTO WEDNESDAY. SHORT TERM: EXPECT VFR CONDITIONS WEDNESDAY NIGHT. IFR CONDITIONS EXPECTED THURSDAY AND FRIDAY. MVFR CONDITIONS EXPECTED SATURDAY. VFR CONDITIONS EXPECTED MONDAY. && .MARINE... NEAR TERM: NO HEADLINES AS CONDITIONS WILL BE BELOW SCA THRESHOLDS. DECIDED TO FOLLOW THE SHORT TERM`S LEAD USING A BLEND OF THE NAM12 AND GFS40 FOR THE SUSTAINED WINDS WHICH SHOW AN INCREASE TO 10-15 KTS WEDNESDAY AFTERNOON. THIS IS IN RESPONSE TO THE S/WV MOVING ACROSS THE REGION. WAVE HEIGHTS ARE FCST TO BE NO HIGHER THAN 3 FT USING THE SWAN GUIDANCE TO INITIALIZE. SHORT TERM: FOR SUSTAINED WINDS HAVE USED A BLEND OF THE NAM12 ...GFS40 AND ECMWF OUT TO 1200Z FRIDAY THEN TRANSITION TO THE SUPPER BLEND WINDS. WILL LOWER SUSTAINED WIND SPEED THURSDAY NIGHT BY 10 PERCENT TO ACCOUNT FOR BOUNDARY LAYER CONDITIONS. FOR WIND GUST SPEED HAVE USED 110 PERCENT OF THE SUSTAINED WIND. FOR WAVES: EXPECT COMBINED SEAS ...MOSTLY COMPOSED OF LOCAL WIND WAVE TO SUBSIDE TO 1-2 FEET WEDNESDAY NIGHT. SOUTHERLY FETCH DEVELOPS FROM GULF OF MAINE AND EXTENDS TO SOUTH THURSDAY IN RESPONSE TO DEEP LOW PRESSURE MOVING INTO THE GREAT LAKES. EXPECT SOUTHERLY WAVE SYSTEM TO BUILD TO 15 FEET/9-10 SECONDS BY MID DAY FRIDAY. LONG PERIOD SOUTHERLY WAVE GROUP WILL SUBSIDE SLOWLY SATURDAY AND SUNDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT SHORT TERM...MIGNONE LONG TERM...MIGNONE AVIATION...HEWITT/MIGNONE MARINE...HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
118 PM EDT TUE OCT 29 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 426 AM EDT TUE OCT 29 2013 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALF OVER THE UPR GREAT LKS BTWN UPR TROF CENTERED OVER ERN HUDSON BAY AND A RDG IN THE PLAINS. SPRAWLING SFC HI PRES/DRY AIRMASS WITH PWAT AOB 0.25 INCH IS CENTERED OVER THE UPR LKS...BRINGING QUIET WX TO THE CWA. ALTHOUGH SOME HI CLDS IN THE RRQ OF A 100KT H3 JET MAX ARE STREAMING INTO THE CWA...TEMPS HAVE FALLEN SHARPLY AND INTO THE TEENS OVER INTERIOR LOCATIONS WITH LIGHT WINDS UNDER THE SFC HI. MORE SC DOES LINGER OVER THE E NEAR LK SUP WITH LLVL NW FLOW E OF THE HI CENTER...AND THESE CLDS HAVE RESTRICTED THE DIURNAL TEMP FALL IN THIS AREA. LOOKING TO THE W...DESPITE SOME DRY LLVL AIR SHOWN ON THE 00Z ABERDEEN SDAKOTA AND BISMARK RAOBS...THERE IS AN AREA OF -SN OVER SRN NDAKOTA AND NRN SDAKOTA. THE PRIMARY FORCING MECHANISMS APPEAR TO BE SOME ISENTROPIC ASCENT ON THE 295-300K SFCS AS WELL AS A BAND OF H7-75 FGEN UNDER UPR DVGC IN RRQ OF THE H3 JET MAX. AN UPSLOPE SFC E WIND ALSO APPEARS TO BE AIDING IN THE LLVL MOISTENING DESPITE THE LLVL DRY AIR FEED OUT OF THE E ON THE SRN FLANK OF THE SFC HI PRES RDG. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE PCPN CHCS OVER UPR MI RELATED TO THE UPSTREAM DISTURBANCE CAUSING SOME -SN IN THE NRN PLAINS. TODAY...AS THE UPR JET CORE SHIFTS TO THE E TODAY...EXPECT THICKENING HI/MID CLDS UNDER ACCOMPANYING UPR DVGC IN THE RRQ OF THIS FEATURE AS SFC HI PRES RDG HANGS BACK INTO THE UPR LKS. AS THE FLOW BACKS TO THE SW...ANY LK CLDS OVER THE E SHOULD SHIFT BACK INTO THE LK. MOST OF THE LARGER SCALE MODELS SHOW SOME PCPN ARRIVING NEAR THE WI BORDER AFT 18Z AS BAND OF H7-75 FGEN SHIFTS TO THE NE. HOWEVER...MOST OF THE HIER RES MODELS SHOW ONLY PATCHY QPF. BIGGEST IMPEDIMENT WL BE LINGERING LLVL DRY AIR AND ABSENCE OF ANY SGNFT UPSLOPE WIND COMPONENT THAT IS AIDING THE LLVL MOISTENING UPSTREAM. OTHER NEGATIVES INCLUDE QUICK DEPARTURE OF UPR JET CORE TO THE E AFT 18Z AND WEAKENING MID LVL ISENTROPIC ASCENT. SO OPTED TO CUT BACK ON POPS OVER THE N HALF OF THE CWA...WITH HIER POPS FOR SOME -SN/-RA NEAR THE WI BORDER...ESPECIALLY IN MNM COUNTY/SCENTRAL WITH A LGT UPSLOPE SE WIND JUST TO THE S OF SFC RDG AXIS. THICKENING CLDS SHOULD RESTRICT THE DIURNAL TEMP RECOVERY...SO TENDED TOWARD THE LOWER END OF GUIDANCE FOR MAX TEMPS. TONIGHT...SUPPORT FOR PCPN IN THE EVNG WL FADE WITH THE ARRIVAL OF LARGER SCALE QVECTOR DVGC/UPR CNVGC IN ADVANCE OF THE UPR RDG MOVING NEWD FM THE PLAINS. ENDED THIS LINGERING PCPN OVER MAINLY THE SCENTRAL BY THE EARLY MRNG HRS ON WED. DESPITE THE VIGOROUS DRYING ALF...MOST MODEL FCST SDNGS INDICATE MSTR WL LINGER IN THE LOWER LVLS...ESPECIALLY OVER THE SCENTRAL WHERE PCPN IS MOST LIKELY TO FALL TODAY. SO MAINTAINED CLDY CONDITIONS IN THIS AREA...WITH PARTIAL CLRG OVER THE NW. THE LOWEST TEMPS SHOULD OCCUR OVER THE INTERIOR NW WHERE SOME CLRG IS LIKELY. IF THE CLDS BREAK UP ELSEWHERE...MIN TEMPS MAY HAVE TO BE ADJUSTED DOWN WITH LGT WINDS UNDER LINGERING SFC RDG AXIS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 426 AM EDT TUE OCT 29 2013 MID-UPR LEVEL TROUGH SLIDES EAST ACROSS THE NATIONS MID SECTION WEDNESDAY INTO THURSDAY. INITIAL TROUGHING LIFTS ACROSS GREAT LAKES TOWARD EASTERN CANADA FRIDAY INTO SATURDAY WHILE SOUTHERN PORTION OF THE TROUGH DOES NOT EXIT EASTERN CONUS UNTIL LATER IN THE WEEKEND. AS THE LEADING TROUGH LIFTS TOWARD GREAT LAKES...SFC LOW PRESSURE TROUGH OVER THE PLAINS ON WEDNESDAY DEVELOPS INTO 1000MB SFC LOW OVER UPR GREAT LAKES BY 12Z THURSDAY...THEN DEEPENS TO 975-980MB LOW BTWN LK SUPERIOR AND JAMES BAY BY 12Z FRIDAY. AS IT HAS LOOKED FOR A WHILE...MAIN PERIOD OF PRECIP...IN THE FORM OF RAIN...OCCURS LATER WEDNESDAY NIGHT INTO THURSDAY WITH MORE SHOWERY PRECIP TAKING OVER IN WAKE OF THE LOW LATER THURSDAY NIGHT INTO FRIDAY. SOUNDINGS FOR WEDNESDAY INDICATE MOISTURE BLO H7 WITH MINIMAL LIFT. THINKING THE LOW-LEVEL MOISTURE IS OVERDONE...BUT DO EXPECT CLOUDS TO THICKEN THROUGHOUT THE DAY AS WARM AIR ADVECTION DEVELOPS OUT AHEAD OF SFC LOW IN THE PLAINS. COULD BE JUST ENOUGH WEAK LIFT AND MOISTURE ADVECTION TO FORM SOME LGT RAIN LATER IN THE WEST OVER THE WEST AND SOUTH...NOT A BIG DEAL AT ALL AS PRIMARY AREA OF RAIN WILL NOT ARRIVE UNTIL LATER WEDNESDAY NIGHT. GIVEN THE CLOUDS...MAX TEMPS ON WEDNESDAY IN THE LOW-MID 40S. TEMPS SHOULD THEN STAY STEADY OR SLOWLY RISE THROUGH WEDNESDAY NIGHT. TIMING OF PRECIP ON WEDNESDAY NIGHT A BIT SLOWER THAN MODELS SHOWED 24 HR AGO. DIVERGENCE ALOFT ON NOSE OF 250MB JET STREAK LIFTING ACROSS UPR LAKES INTERACTS WITH H85 AND H7 MOISTURE ADVECTION TO THE NORTH OF SFC-H85 LOWS. EXPECT BRIEF PERIOD OF MODERATE RAIN TO SWEEP FROM SOUTH TO NORTH ACROSS CWA. EVEN WITH RAIN MOVING THROUGH...PUT A MENTION OF FOG IN OVERNIGHT WEDNESDAY NIGHT INTO THURSDAY MORNING AS DWPNTS RISING INTO THE 40S TO LOWER 50S WILL BE RIDING OVER COLDER GROUND SFC WITH 2 INCH SOIL TEMPS WELL BLO 40 THE LAST WEEK OR SO. IF THE RAIN EXITS QUICKER...THEN THE FOG WOULD LIKELY BECOME MORE WIDESPREAD. DRY SLOT/MID-LEVEL DRYING TAPERS OFF RAIN ON THURSDAY MORNING. AS LONG AS WINDS ARE NOT TOO STRONG FOG COULD PERSIST OVER THE UPSLOPE AREAS OF CNTRL UPR MICHIGAN INTO THE MIDDLE PART OF THE DAY. WINDS SHIFT TO WEST AND START TO INCREASE IN THE AFTN AS SFC LOW CENTER MOVES TO CNTRL OR EASTERN LK SUPERIOR WHILE DEEPENING. DESPITE CLOUDS/FOG AND SPOTTY RAIN...MAX TEMPS WILL STILL PUSH WELL INTO THE 50S FROM SHEAR ADVECTION ALONE IN THE WARM SECTOR OF THE SFC LOW. ANOTHER WAVE OF RAIN COULD DEVELOP LATE AFTN/THURSDAY EVENING AS PRIMARY HEIGHT FALLS AND DEEP LAYER Q-VECTOR CONVERGENCE SWEEPS IN OVER MAINLY SOUTH AND EAST CWA. KEPT POPS HIGHEST TO THE EAST OF MQT AND ESC AS THAT IS WHERE LARGER SCALE FORCING INTERACTS WITH BETTER MOISTURE ADVECTION. BASED ON GRADIENT OF MID-LEVEL MOISTURE AND FCST H7-H5 LAPSE RATES...THINKING BETTER CHANCES OF TSRA WILL REMAIN TO THE SOUTH AND EAST OF CWA LATER THURSDAY AFTN INTO EVENING. STRONGER SHORTWAVE/DEEP MOISTURE MAY DROP ACROSS GREAT LAKES FRIDAY NIGHT INTO SATURDAY WHILE COOLER AIRMASS LINGERS AS H85 TEMPS FALL TO -4C TO -6C BY 12Z SATURDAY. NW-NNW CYCLONIC FLOW AT 1000-850MB PERSISTS THROUGH SATURDAY SUGGESTING THERE WILL LIKELY BE SOME LAKE ENHANCED PRECIP. 1000-850MB/H85-H7 THICKNESSES AND FORECAST SFC TEMPS POINT TO MAINLY SNOW FOR PTYPE FRIDAY NIGHT INTO SATURDAY MORNING OVER THE WEST WITH RAIN/SNOW MIX FARTHER EAST. DETAILS WILL NEED TO BE SORTED OUT LATER THIS WEEK...BUT DOES SEEM THAT THE FRIDAY NIGHT INTO SATURDAY MORNING PERIOD HOLDS SOME POTENTIAL FOR ACCUMULATING SNOW OVER THE HIGHER TERRAIN OF WEST AND NORTHWEST UPR MICHIGAN. TEMPS COOL FURTHER INTO SATURDAY NIGHT BUT DEEPER MOISTURE AND CYCLONIC FLOW WILL BE EASING AS SFC-H85 RIDGE NEARS FROM THE WEST. LAKE EFFECT SNOW SHOWERS COULD CONTINUE MOST OF THE NIGHT...MAINLY FOR NW FLOW AREAS TO THE EAST OF MARQUETTE. SUNDAY IS A TRANSITION DAY IN WEATHER. EASTERN CONUS TROUGH EDGES EAST AS STRONGER JET ENERGY MOVES TO FRONT SIDE OF TROUGH WHICH THEN CLEARS WAY FOR WESTERN CONUS TROUGH TO EXPAND TOWARD ROCKIES AND RIDGING TO EXPAND ACROSS THE GREAT LAKES. RIDGING LOOKS BRIEF THOUGH AS THE TROUGHING OVER THE WESTERN CONUS EXPANDS INTO THE PLAINS LEADING TO A POTENTIALLY ACTIVE SW FLOW PATTERN ACROSS THE GREAT LAKES BY EARLY NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 118 PM EDT TUE OCT 29 2013 EXPECT VFR CONDITIONS AND LGT WINDS UNDER LINGERING SFC RDG AXIS THRU MID AFTERNOON. AN UPR DISTURBANCE WL BRING SOME -SN TO MAINLY THE S HALF OF UPR MI LATE THIS AFTN/EVNG...AND CONDITIONS WILL DROP TO MVFR AT THE MORE SRN SAW/IWD LOCATIONS DURING THIS TIME WHEN THE LLVL DRY AIR IS MOISTENED SUFFICIENTLY BY THE PCPN. CMX IS LIKELY TO REMAIN VFR WITH THE PCPN REMAINING TO THE S. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 426 AM EDT TUE OCT 29 2013 LIGHT WINDS LESS THAN 20 KTS THROUGH WEDNESDAY AS HIGH PRESSURE RIDGE OVER THE AREA SLOWLY MOVES TOWARD THE EAST COAST. LOW PRESSURE DEVELOPING OVER THE PLAINS ON WEDNESDAY WILL LIFT TOWARD THE UPPER GREAT LAKES ON THURSDAY THEN DEEPEN AS IT MOVES INTO QUEBEC ON FRIDAY. SE-E WINDS 20-25 KTS WEDNESDAY NIGHT INTO THURSDAY AHEAD OF THE SYSTEM...THEN AFTER THE LOW MOVES EAST OF THE LAKE...EXPECT WINDS TO SHIFT NW 25-30 KTS THURSDAY NIGHT THROUGH SATURDAY AS COLDER AIR PLUNGES ACROSS THE UPPER LAKES REGION. WINDS DIMINISH ON SUNDAY WITH ARRIVAL OF HIGH PRESSURE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...07 MARINE...JLA
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1251 PM CDT TUE OCT 29 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 338 AM CDT TUE OCT 29 2013 THE DEEP H500 MB UPPER LEVEL LOW ACROSS THE WESTERN U.S. IS EXPECTED TO LIFT SLOWLY NORTHEAST INTO WRN WY BY 12Z WEDNESDAY. THE MODELS ARE STRENGTHENING THE WARM AIR ADVECTION FROM 850 MB TO 700 MB AS THE LOW LIFTS NORTH BUT REMAIN WEST OF THE FORECAST AREA. THUS THE THREAT OF FREEZING PRECIPITATION WOULD APPEAR TO BE DECREASING SOMEWHAT. THE MODELS SHOW A STRONG DRY SLOW WORKING INTO THE FCST AREA BETWEEN 850-700MB DURING THE DAY TODAY. AS THE UPPER LEVEL COLD POOL NOSES INTO WYOMING TONIGHT...STEEPENING LAPSES MIGHT SUPPORT AN ORGANIZED ROUND OF ACCUMULATING ICE ACROSS THE PANHANDLE AND PERHAPS INTO WESTERN NEBRASKA. TEMPERATURES AT 700 MB IN THESE AREAS COOL TO -2C TO -4C WHICH WOULD NOT SUPPORT RAPID SNOW GROWTH AND GIVEN THE STRENGTHENING WARM AIR ADVECTION AT 850MB...ALL MODELS ARE ABOVE FREEZING 1C TO 4C...FREEZING RAIN WOULD APPEAR TO BE THE ONLY THREAT. NOTE THE BEST GUESS AT MIN TEMPERATURES WEDNESDAY MORNING PRODUCED LOWS NEAR 30 ACROSS THE NORTHWEST ZONES WITH A FREEZING LINE RUNNING FROM ROUGHLY BIG SPRINGS TO AINSWORTH. HIGHS TODAY RISE TO THE MID 30S ACROSS SHERIDAN AND CHERRY COUNTIES. THE RAP MODEL PRODUCED HIGHS AROUND 33 IN THAT AREA THIS AFTERNOON AND THE HRRR SHOWED 35F. WITH LOWS FALLING TO AROUND 30 TONIGHT...IT WOULD APPEAR ABOUT 8 TO 10 HOURS OF SUBFREEZING WEATHER COULD DEVELOP WHICH WOULD NECESSITATE ANOTHER WINTER WEATHER ADVISORY ACROSS SHERIDAN AND CHERRY COUNTIES. TEMPERATURES TODAY SHOULD RISE ABOVE THE FREEZING MARK AROUND NOON IN THIS AREA AND WE ARE FORECASTING WARMER LOWS TONIGHT THAN ARE OCCURRING THIS MORNING. GIVEN THE DRY AIR MOVING IN ALOFT AHEAD OF THE UPPER LOW...FOG COULD BECOME A BIT MORE WIDESPREAD TONIGHT BUT MAINLY EAST OF HIGHWAY 83 AS SUGGESTED IN THE 850-700MB MOISTURE FIELDS. DRIZZLE WOULD APPEAR TO BE THE OPERATIVE PRECIPITATION MODE WITH THE SHALLOW MOISTURE PROFILES ALONG AND EAST OF HIGHWAY 83 BUT SOME SOLNS LIKE THE GFS DEVELOP WIDESPREAD LIGHT RAIN ALONG AND EAST OF HIGHWAY 83. THE OTHER MODELS DO THE SAME BUT ARE FARTHER EAST FAVORING CENTRAL AND EASTERN NEB WITH THIS RAIN. IT LOOKS LIKES THE GFS IS MAINTAINING A STRONGLY BACK LOW LEVEL FLOW TONIGHT WHILE THE NAM FOR EXAMPLE VEERS THE 850 WINDS A BIT MORE TOWARD ERN NEB. THE 305K ISENTROPIC MOISTURE TRANSPORT VECTORS IN BOTH MODELS IS DIRECTED TOWARD EASTERN AND CNTL NEB. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 338 AM CDT TUE OCT 29 2013 STORM SYSTEM WILL CONTINUE MOVING THROUGH THE CENTRAL AND NORTHERN PLAINS DURING THE DAY WEDNESDAY...EXITING TO THE NORTHEAST WEDNESDAY NIGHT. AS THE UPPER TROUGH AXIS CROSSES THE AREA WEDNESDAY...SHOWERS WILL CONTINUE TO BE POSSIBLE. WARM AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL CONTINUE TO KEEP MOST OF THE PRECIPITATION IN LIQUID FORM. REALLY LITTLE CHANCE OF SNOW...AS ALL MODELS KEEP TEMPERATURES AT 850MB ABOVE FREEZING. AT THE SURFACE HOWEVER...SHALLOW ARCTIC AIR WILL REMAIN ACROSS THE AREA...WITH TEMPERATURES WEDNESDAY MORNING NEAR OR A FEW DEGREES BELOW FREEZING ACROSS PORTIONS OF NORTHERN AND NORTHWEST NEBRASKA. FREEZING RAIN WILL LIKELY BEGIN THE DAY...BUT WILL QUICKLY CHANGE TO RAIN AS TEMPERATURES WARM ABOVE FREEZING BY MID MORNING. FARTHER EAST ACROSS CENTRAL AND SOUTHWEST NEBRASKA...SUFFICIENT MID LEVEL INSTABILITY WARRANTS A THUNDER MENTION DURING THE MORNING. BY AFTERNOON...DRY AIR IN THE MID LEVELS SPREADS NORTHEAST...ENDING PRECIPITATION FROM SOUTHWEST TO NORTHEAST. SKIES BEGIN TO CLEAR WEDNESDAY NIGHT...WITH DOWNSLOPE FLOW AND SUNNY SKIES BOOSTING HIGHS THURSDAY INTO THE 50S TO NEAR 60. DRY AND MILD WEATHER WILL CONTINUE THROUGH THE WEEKEND...AHEAD OF THE NEXT UPPER TROUGH AND POTENTIAL PRECIPITATION EARLY NEXT WEEK. DETAILS REMAIN SKETCHY WITH THIS NEXT SYSTEM...AND WILL ONLY CARRY SLIGHT CHANCES FOR RAIN/SNOW AT THIS TIME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1250 PM CDT TUE OCT 29 2013 WIDESPREAD IFR OR LIFR CONDITIONS EXPECTED TO CONTINUE THE NEXT 24 HOURS. PLENTIFUL MOISTURE IS TRAPPED IN THE BOUNDARY LAYER WITH MODELS IN GOOD AGREEMENT RESULTING IN HIGH CONFIDENCE OF CIGS REMAINS BELOW OVC010. BETTER LIFT WITHIN THE BOUNDARY LAYER RESULTING IN SCT SHOWERS EAST OF HIGHWAY 83...OTHERWISE AREAS OF DRIZZLE AND FOG WILL DOMINATE. TEMPERATURES TONIGHT ACROSS NW NEB DROP TO OR BELOW FREEZING WITH THE POSSIBILITY OF FREEZING PRECIP/LIGHT ICING. IMPACT AT THE KVTN TERMINAL IS POSSIBLE...HOWEVER EXPECT KLBF TO REMAIN WARM ENOUGH FOR LIQUID PRECIP. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
124 PM CDT TUE OCT 29 2013 .UPDATE... ISSUED AT 124 PM CDT TUE OCT 29 2013 HAVE RECEIVED REPORTS OF PATCHY FREEZING DRIZZLE ACROSS PORTIONS OF THE JAMES RIVER VALLEY SOUTH OF JAMESTOWN EARLY THIS AFTERNOON. THUS...ADDED THE MENTION OF PATCHY FREEZING DRIZZLE TO THESE LOCATIONS AND ACROSS THE SOUTHWEST WHERE CEILINGS ARE BELOW 1000 FEET. THE LACK OF ICE CRYSTALS IN THE COLUMN WITH SATURATION WARMER THAN -10 C AND SURFACE TEMPERATURES IN THE UPPER 20S WILL CONTINUE FOR THESE LOCATIONS THROUGH THE AFTERNOON...WITH THE THREAT EXPANDING TO POTENTIALLY IMPACT MOST LOCATIONS SOUTH OF ND HIGHWAY 200 THROUGH THE NIGHT. UPDATE ISSUED AT 1017 AM CDT TUE OCT 29 2013 NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE. THE BIGGEST QUESTION WILL BE HOW MUCH STRATUS WILL BE ERODED THROUGH THE AFTERNOON. THE 14 UTC RAP HOLDS NEARLY THE ENTIRE STRATUS FIELD THIS MORNING IN PLACE...WHILE THE 12 UTC NAM SUGGESTS SOME CLEARING NORTH AS THE SURFACE RIDGE AXIS SLOWLY PROPAGATES SOUTH. WILL CONTINUE TO MONITOR TRENDS...HOWEVER...LEANED CLOSER TO THE RAP GIVEN WEAK EASTERLY UPSLOPE FLOW. UPDATE ISSUED AT 641 AM CDT TUE OCT 29 2013 HIGH PRESSURE JUST NORTH OF MINNESOTA AT 6 AM CDT WAS RESPONSIBLE FOR KEEPING SKIES MOSTLY CLEAR OVER THE NORTH CENTRAL PORTION OF THE STATE OVERNIGHT. LOWS HERE FELL INTO THE TEENS. SKIES WERE CLOUDY ACROSS THE REMAINDER OF THE FORECAST AREA. ALTHOUGH LIGHT SNOW THAT FELL ACROSS THE SOUTHWEST AND FAR SOUTH CENTRAL HAS NOW DISSIPATED. HAVE UPDATED POPS THIS MORNING...STARTING OUT DRY ACROSS THE CWA. MESOSCALE MODELS CONTINUE TO INDICATE LIGHT PRECIPITATION LIFTING NORTH FROM SOUTH DAKOTA DURING THE DAY SO BROUGHT IN SMALL PRECIPITATION CHANCES ACROSS THE FAR SOUTH DURING THE MORNING AND KEPT THE CHANCE ACROSS THE SOUTH THIS AFTERNOON. CLOUDS CONTINUE TO BUILD FROM WEST TO EAST ACROSS THE NORTH...SO THE MAINLY CLEAR SKIES IN THE NORTH CENTRAL EARLY THIS MORNING SHOULD CLOUD OVER IN THE NEXT FEW HOURS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 329 AM CDT TUE OCT 29 2013 FOCUS OF THE SHORT TERM INCLUDES ANTICIPATED DIMINISHING SNOWFALL THIS MORNING...THEN PRECIPITATION CHANCES AND PRECIP TYPE THIS AFTERNOON AND TONIGHT. AT 3 AM CDT...THE UPPER LEVEL LOW REMAINED OVER THE ROCKIES NEAR NEVADA/IDAHO WITH SOUTHWEST FLOW ALOFT ACROSS THE EASTERN ROCKIES...THE FRONT RANGE...AND INTO THE DAKOTAS. AT THE SURFACE...COLD HIGH PRESSURE WAS CENTERED AT THE BORDER OF MANITOBA/NORTH DAKOTA/MINNESOTA...WITH LOW PRESSURE OVER COLORADO/WYOMING. THIS WAS RESULTING IN MAINLY CLEAR SKIES OVER THE NORTHEASTERN HALF OF NORTH DAKOTA...AND CLOUDS OVER THE SOUTHWEST HALF. LIGHT SNOW FROM ISENTROPIC LIFT/OVERRUNNING PRECIPITATION FROM EASTERN MONTANA ACROSS WESTERN AND SOUTH CENTRAL NORTH DAKOTA INTO NORTHERN SOUTH DAKOTA APPEARED TO BE DECREASING IN INTENSITY AND COVERAGE OVER THE PAST COUPLE OF HOURS...EXCEPT FOR AN ENHANCED AREA OF LIGHT SNOW OVER NORTH CENTRAL/NORTHEASTERN SOUTH DAKOTA THAT WAS MOVING NORTHEASTWARD INTO THE JAMES RIVER VALLEY. THE HRRR 3KM REFLECTIVITY HAS A GOOD HANDLE ON CURRENT RADAR RETURNS AND WILL FOLLOW THIS TREND IN THAT MODEL FOR THE MORNING HOURS. THE HRRR DIMINISHES THE SNOWFALL OVER WESTERN NORTH DAKOTA TO NOTHING AFTER DAYBREAK/12Z. THE MODEL INDICATES SOME CHANCES OF PRECIPITATION IN PORTIONS OF SOUTH CENTRAL/SOUTHEASTERN NORTH DAKOTA DURING THE MORNING HOURS. FEEL CONFIDENT THAT BY 6 AM MDT THE ADVISORY SHOULD BE ALLOWED TO EXPIRE. WILL KEEP SMALL CHANCES OF PRECIPITATION ACROSS THE FAR SOUTHERN TIER OF COUNTIES THIS MORNING. FOR THIS AFTERNOON...THE MODELS DEPICT THE UPPER LOW MOVING NORTHEAST TO WYOMING AND CONTINUED UPPER LEVEL ENERGY IMPULSES MOVING NORTHEASTWARD TOWARDS NORTH DAKOTA. THUS THE MODELS WERE KEEPING PRECIPITATION VERY CLOSE TO THE ND BORDER IN SOUTH DAKOTA...AND WILL KEEP SMALL CHANCE MENTIONS OF LIGHT SNOW OR LIGHT RAIN. HIGH TEMPERATURES EXPECTED TO REACH ONLY INTO THE 30S...BUT WITH WARM ADVECTION ALOFT BRINGING A CHANCE OF RAIN/SNOW TO THE FAR SOUTH. FOR TONIGHT...THE UPPER LOW REMAINS OVER WYOMING WITH CONTINUED ENERGY IMPULSES MOVING NORTHWARD ACROSS THE DAKOTAS. WARM ADVECTION ALOFT CONTINUES WITH SURFACE TEMPERATURES DROPPING BACK INTO THE UPPER 20S. TEMPERATURE PROFILES FROM BUFKIT SOUNDINGS STILL SUPPORT FREEZING RAIN. THUS WILL CONTINUE THE CHANCES OF FREEZING RAIN ACROSS THE SOUTHERN TIER OF COUNTIES AS HAS BEEN ANTICIPATED FOR THE PAST FEW DAYS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 329 AM CDT TUE OCT 29 2013 MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE PRECIPITATION CHANCES AND TYPE WEDNESDAY AND WEDNESDAY NIGHT AS AN UPPER LEVEL LOW MOVES THROUGH THE LOCAL AREA. MODELS ARE IN REASONABLE AGREEMENT AND UTILIZED A MODEL BLEND WITH PERSISTENCE FOR FORECAST ELEMENTS. THE UPPER LEVEL LOW TRACKING ACROSS THE NORTHERN ROCKIES MOVES INTO THE NORTHERN PLAINS WEDNESDAY. THE MAIN SURFACE LOW REMAINS OVER THE CENTRAL PLAINS BUT WARM ADVECTION LIFTS FROM THE PLAINS INTO THE CENTRAL AND EASTERN DAKOTAS ON WEDNESDAY WITH THE GFS/EC AND GLOBAL GEM ALL PRODUCING QPF OVER OUR FAR SOUTH CENTRAL AND SOUTHEAST CWA. WITH SURFACE TEMPERATURES HOVERING AROUND FREEZING AND MAX TEMPERATURES ALOFT GENERALLY 2-4 DEGREES CELSIUS...THERE WILL BE A THREAT OF FREEZING RAIN ALONG THE SOUTH DAKOTA BORDER WEDNESDAY MORNING. AS TEMPERATURES RISE INTO THE UPPER 30S TO LOWER 40S WEDNESDAY AFTERNOON THE PRECIPITATION IS EXPECTED TO BE ALL RAIN. BY WEDNESDAY EVENING THE UPPER LOW MOVES EAST AND COLDER AIR FILTERS INTO THE REGION. BY THIS TIME ANY LINGERING PRECIPITATION IS EXPECTED TO BE MAINLY OVER THE JAMES RIVER VALLEY...AND AS TEMPERATURES COOL DURING THE EVENING WE COULD AGAIN SEE A MIXED BAG OF LIGHT RAIN/FREEZING RAIN OR SNOW BEFORE THE PRECIPITATION ENDS. WILL NEED TO MONITOR FOR POSSIBLE FREEZING RAIN HIGHLIGHTS FAR SOUTH CENTRAL AND SOUTHEAST...BUT AT THIS TIME THE GREATEST POTENTIAL FOR ACCUMULATING PRECIPITATION APPEARS TO BE WEDNESDAY AFTERNOON WHEN TEMPERATURES WILL BE WARM ENOUGH THAT RAIN WILL BE THE PREDOMINANT PRECIPITATION TYPE. NORTHWEST FLOW DEVELOPS THURSDAY INTO FRIDAY. EMBEDDED IMPULSES IN A STRONG NORTHWEST UPPER FLOW COULD BRING A RAIN OR SNOW SHOWER TO THE NORTH AND EAST ON FRIDAY...WITH BREEZY NORTHWEST WINDS EXPECTED ACROSS THE AREA. HIGH TEMPERATURES SHOULD REMAIN IN THE 40S. THE NEXT SYSTEM COMING OFF THE PACIFIC LIFTS INTO SOUTHERN CANADA OVER THE WEEKEND. THIS WILL INDUCE A SOUTHEAST FLOW ACROSS THE AREA LATE SATURDAY THROUGH SUNDAY WITH HIGH TEMPERATURES MAINLY IN THE MID TO UPPER 40S AND POSSIBLY SOME 50S IN THE WEST. A COLD FRONT MOVES THROUGH ON MONDAY BRINGING US BACK DOWN INTO THE UPPER 30S AND 40S. HAVE STUCK WITH PERSISTENCE AND KEPT A SLIGHT CHANCE OF PRECIPITATION ACROSS THE NORTH ON SUNDAY AND MONDAY. ALTHOUGH LATEST GUIDANCE IS SUGGESTING THAT THE LOW OVER SOUTHERN CANADA MAY BE FAR ENOUGH NORTH THAT WE WILL REMAIN IN THE DRY SECTOR...ESPECIALLY ON SUNDAY...WITH MAYBE A FEW COLD ADVECTION RAIN OR SNOW SHOWERS ON MONDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 124 PM CDT TUE OCT 29 2013 IFR CONDITIONS IN STRATUS AND FREEZING DRIZZLE WILL CONTINUE AT KDIK THIS AFTERNOON THROUGH TONIGHT. KBIS AND KJMS ARE EXPECTED TO FALL TO IFR IN STRATUS AND FREEZING DRIZZLE AS WELL IN THE 06-09 UTC TIME FRAME TONIGHT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...JV LONG TERM...TWH AVIATION...AYD
AREA FORECAST DISCUSSION
NWS NORMAN OK
331 PM CDT TUE OCT 29 2013 .DISCUSSION... STORM SYSTEM OVER NEVADA WILL MOVE TOWARD THE AREA BRINGING STORM CHANCES THROUGH THURSDAY MORNING. FOR TONIGHT... WILL FIRST WATCH FOR ANY CONVECTION THAT MIGHT DEVELOP ALONG THE SURFACE FRONT THAT CURRENTLY EXTENDS FROM NORTH CENTRAL INTO WEST CENTRAL OKLAHOMA. SOME INSTABILITY HAS DEVELOPED PER MESOANALYSIS DESPITE THE CLOUDINESS. RAP... HRRR AND LOCAL WRF SUGGEST THAT SOME DEVELOPMENT IS AT LEAST POSSIBLE LATE THIS AFTERNOON. THIS BOUNDARY IS EXPECTED TO WASH OUT AND/OR LIFT NORTH INTO KANSAS. WITH THIS PRIMARY FOCUS LIFTING INTO KANSAS... THE HIGHEST CHANCE OF PRECIPITATION WILL BE ACROSS NORTHERN OKLAHOMA ALTHOUGH SOME NUMERICAL GUIDANCE SUGGEST THAT AT LEAST THE CHANCE FOR SCATTERED STORMS FARTHER SOUTH. STORMS ARE LIKELY AS THE STORM SYSTEM APPROACHES WEDNESDAY AND MOVES OVER THE PLAINS THURSDAY MORNING. HEAVY RAINFALL WILL BE POSSIBLE IN SOUTHEASTERN OKLAHOMA. DID CONSIDER A SMALL FLASH FLOOD WATCH SOUTHEAST... BUT THE FLASH FLOOD GUIDANCE IS STILL RELATIVELY HIGH AND THE HEAVIEST RAIN CURRENTLY LOOKS TO FALL JUST EAST OF THE CWA. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 66 72 61 71 / 40 70 50 20 HOBART OK 65 75 58 70 / 40 50 40 10 WICHITA FALLS TX 66 77 64 73 / 50 70 40 10 GAGE OK 60 75 48 68 / 40 30 30 0 PONCA CITY OK 66 73 59 67 / 60 80 60 30 DURANT OK 66 72 67 77 / 40 90 80 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
158 PM CDT TUE OCT 29 2013 .AVIATION... FOR THE 18Z TAFS...TIMING OF MVFR CIGS AND THE ONSET OF PRECIPITATION ACROSS THE REGION IS THE PRIMARY AVIATION WEATHER CONCERN THROUGH THE VALID FORECAST PERIOD. MVFR CIGS REMAINED IN PLACE ACROSS ALL AREA TAF SITES AT THE START OF THE VALID FORECAST PERIOD. LATEST RAP SOUNDINGS AND UPSTREAM TRENDS INDICATE CIGS SHOULD LIFT ABOVE 2 KFT BY 3 PM CDT...LIFTING TO VFR LEVELS BY 6 PM CDT. MVFR CIGS ARE LIKELY TO RETURN TO THE REGION LATE TONIGHT AS WEAK WARM AIR ADVECTION ASSOCIATED WITH A RELATIVELY STRONG LOW LEVEL JET OF 40 TO 45 KTS WILL PROVIDE SOME GRADUAL MOIST LIFT OVERNIGHT OVER THE REGION. ONCE IN PLACE...MVFR CIGS WILL LIKELY PERSIST THROUGHOUT THE DAY ON WEDNESDAY AS AN UNSEASONABLY DEEP MOIST AIR MASS HOLDS OVER THE AREA THROUGH THURSDAY AFTERNOON. ISOLATED TO SCATTERED RAIN SHOWERS ARE POSSIBLE ANYTIME FROM THIS EVENING THROUGH TOMORROW MORNING. AT THIS TIME THESE RAIN CHANCES WERE TOO LOW TO MENTION IN THE TAFS...SO JUST HAVE CHANGE GROUPS IN THE EARLY PART OF THE TAF FOR CIG HEIGHTS. WIDESPREAD RAIN SHOWERS ARE MORE LIKELY TOMORROW MORNING...AND HAVE A VCSH IN AT ALL AREA TAFS STARTING AT 15Z AS A RESULT. THUNDERSTORMS ARE MOST LIKELY TO AFFECT AREA TAF SITES WEDNESDAY AFTERNOON WHICH WAS BEYOND THE VALID FORECAST PERIOD FOR ALL SITES BUT DFW. WILL LIKELY NEED TO MAKE CHANGES TO THE TAFS WITH REGARDS TO THE TIMING OF PRECIPITATION IN FUTURE FORECASTS. CAVANAUGH && .PREV DISCUSSION... /ISSUED 403 AM CDT TUE OCT 29 2013/ AN UPPER LEVEL LOW CURRENTLY OVER NORTHERN NEVADA WILL MOVE EAST ACROSS THE NORTHERN AND CENTRAL PLAINS WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING. MODELS ARE IN GOOD AGREEMENT WITH THE TRACK AND TIMING OF THIS SYSTEM. WE WILL CONTINUE TO SEE AN INCREASE IN BOTH LOW LEVEL AND MID/UPPER LEVEL MOISTURE AHEAD OF THIS SYSTEM. PRECIPITABLE WATER VALUES EXPECTED TO CLIMB TO 1.5 TO OVER 2 INCHES BY WEDNESDAY MORNING. THIS WILL PUT MOST OF THE FORECAST AREA 2 STANDARD DEVIATIONS ABOVE CLIMATOLOGICAL NORMALS AND NEAR THE 99TH PERCENTILE. HAVE PLACED A MENTION OF HEAVY RAIN IN THE FORECAST FOR THE WEDNESDAY AND WEDNESDAY NIGHT PERIOD. RAINFALL TOTALS FOR THE EVENT WILL LIKELY AVERAGE FROM AROUND 1 INCH ACROSS THE NORTHWESTERN MOST COUNTIES TO 2 TO 4 INCHES ACROSS THE AREA ALONG AND EAST OF THE I-35 CORRIDOR. WE WILL LIKELY BE ISSUING A FLASH FLOOD WATCH FOR THE EASTERN TWO THIRDS OF THE FORECAST AREA FOR THE WEDNESDAY AND WEDNESDAY NIGHT PERIOD LATER THIS MORNING OR THIS AFTERNOON. THERE WILL ALSO BE THE POTENTIAL FOR SOME STORMS TO BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS BEING THE THREATS. AS THE TROUGH MOVES EAST...A COLD FRONT WILL MOVE INTO THE WESTERN PART OF THE FORECAST AREA AFTER MIDNIGHT WEDNESDAY NIGHT AND THIS FRONT WILL MOVE TO THE EAST OF THE FORECAST AREA BY MIDDAY. SOME HEAVY RAIN MAY CONTINUE INTO THURSDAY MORNING ACROSS THE SOUTHEASTERN THIRD OF THE FORECAST AREA. THE RAIN WILL END WEST OF A PARIS... CORSICANA...TEMPLE LINE BY MIDDAY THURSDAY AND END ACROSS THE REST OF THE FORECAST AREA DURING THE AFTERNOON. DRY WEATHER IS THEN EXPECTED FOR THE REST OF THURSDAY THROUGH SUNDAY. WE WILL BE IN NORTHWESTERLY FLOW ALOFT IN THE WAKE OF THE EXITING UPPER TROUGH FRIDAY THROUGH SATURDAY MORNING. UPPER LEVEL RIDGING WILL TRANSIT TEXAS SATURDAY AFTERNOON THROUGH SUNDAY MORNING AS ANOTHER UPPER LEVEL TROUGH DIGS INTO THE WESTERN U.S. THIS WILL PUT US IN SOUTHWESTERLY FLOW ALOFT FOR SUNDAY AFTERNOON INTO THE EARLY PART OF NEXT WEEK. RAIN CHANCES WILL RETURN TO THE FORECAST AREA SUNDAY NIGHT AND CONTINUE THROUGH TUESDAY. WE WILL THEN DRY OUT TUESDAY NIGHT AS THE UPPER LEVEL TROUGH MOVES OFF TO THE EAST. 58 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 80 69 77 69 80 / 20 40 80 90 30 WACO, TX 81 67 77 68 81 / 10 40 80 90 40 PARIS, TX 79 66 75 67 77 / 20 40 80 90 50 DENTON, TX 79 65 73 67 77 / 20 50 80 80 30 MCKINNEY, TX 79 68 75 68 78 / 20 40 80 90 30 DALLAS, TX 80 71 77 71 81 / 20 40 80 90 30 TERRELL, TX 81 69 76 69 79 / 10 40 80 90 50 CORSICANA, TX 81 68 77 70 79 / 10 30 70 90 50 TEMPLE, TX 81 68 77 69 80 / 10 40 70 90 50 MINERAL WELLS, TX 79 66 77 65 76 / 20 60 80 70 20 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
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AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
139 PM EDT TUE OCT 29 2013 .SYNOPSIS... A WEAK FRONT EXTENDED FROM VIRGINIA TO A LOW IN KANSAS MISSOURI...WHILE HIGH PRESSURE COVERED THE NORTHERN PLAINS TO THE GREAT LAKES. TUESDAY AND WEDNESDAY THE LOW WILL DEEPEN OVER THE CENTRAL PLAINS AND MOVE SLOWLY NORTHEAST. BY FRIDAY THE LOW WILL BE OVER THE GREAT LAKES AND A STRONG COLD FRONT WILL MOVE ACROSS THE EASTERN UNITED STATES. && .NEAR TERM /THROUGH TONIGHT/... AS OF 100 PM EDT TUESDAY... DECREASED CLOUD COVER AND POPS FOR THIS AFTERNOON INTO TONIGHT. ADJUSTED TEMPERATURES FOR THE LESS CLOUD COVER. AS OF 915 AM EDT TUESDAY... LOW CLOUDS AND FOG WILL SLOWLY LIFT OR ERODE WITH MIXING AND HEATING THIS MORNING. THIS MORNING 12Z/8AM RNK SOUNDING SHOWED LOW LEVEL MOISTURE UP TO 850 MB WITH THE NORTHWEST FLOW JUST ABOVE THE SURFACE. HRRR AND RNK WRFARW INDICATED LIGHT RAIN DEVELOP AFTER 18Z THIS AFTERNOON. DECIDED TO CUT BACK ON MORNING POPS INTO THIS AFTERNOON. WILL ALLOW FOR SOME ISOLATED RAIN MAINLY ALONG AND WEST OF I77 THIS AFTERNOON INTO TONIGHT. MODIFIED TEMPERATURES...DEW POINTS AND CLOUD COVER WITH LATEST OBS TRENDS FOR THIS MORNING. MORE CHANGES LATER TODAY... AS OF 345 AM EDT TUESDAY... A WEAK STATIONARY BOUNDARY ALONG THE NORTHERN EDGE OF AN AIR MASS WITH HIGHER SURFACE DEW POINTS. SCATTERED RAIN NORTH OF BLUEFIELD AND ROANOKE EARLY THIS MORNING WAS MOVING EAST AND DISSIPATING. DO NOT THINK THE PROBABILITY OF RAIN WILL COMPLETELY GO AWAY BUT JUST BE AT A MINIMUM TODAY. BY THIS EVENING ANOTHER SHORT WAVE TRACKING ALONG THE NORTHERN FRINGE OF BUILDING UPPER RIDGE WILL BE REACHING THE WESTERN COUNTY WARNING AREA. MODELS WERE ALSO SHOWING BETTER ISENTROPIC LIFT TONIGHT AROUND THE 290K LEVEL. EXPECT PROBABILITY OF PRECIPITATION TO INCREASE AND GRADUALLY MOVE EAST OVERNIGHT. WITH ALL THE CLOUD COVER TODAY...AGAIN WENT COOLER THAN GUIDANCE FOR MAXIMUM TEMPERATURES IN THE MOUNTAINS TODAY. GUIDANCE FOR MONDAY WAS TOO WARM IN THIS AREA. EAST OF THE BLUE RIDGE USED A BLEND OF BIAS CORRECTED ADJMET/ADJMAV NUMBERS. 850 MB START OUT FROM THE WEST TODAY AND EVENTUALLY BECOME SOUTH TONIGHT. WITH WEAK WARM ADVECTION AND ABUNDANT CLOUD COVER...TEMPERATURES WILL HAVE A LIMITED DROP OVERNIGHT...ESPECIALLY ALONG THE RIDGES. STAYED CLOSER TO WARMER MET GUIDANCE FOR MINIMUM TEMPERATURES. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... AS OF 330 AM EDT TUESDAY... FOR WEDNESDAY...MODELS ARE IN BETTER AGREEMENT THIS MORNING THAT WE WILL START THE DAY OFF WITH A WARM FRONT SITUATED NEAR THE INTERSTATE 64 CORRIDOR. MINOR DISTURBANCES RIDING ALONG THE BOUNDARY FROM THE WEST WILL PASS ACROSS OUR AREA DURING THE MORNING AND EARLY AFTERNOON...TRIGGERING SPOTTY SHOWERS GENERALLY WITH LIGHT RAINFALL AMOUNTS. THE FRONT WILL LIFT NORTH THROUGH THE DAY...LEAVING THE MID ATLANTIC SITUATED IN AN AREA OF STRONG SOUTHWESTERLY WINDFLOW. RISING 500MB HEIGHTS AS AN UPPER LEVEL RIDGE BUILDS IN FROM THE WEST WILL ALLOW THE WARMUP TO CONTINUE...AS AFTERNOON HIGHS RANGE FROM THE MID/UPPER 60S ACROSS THE MOUNTAINS...TO THE LOW 7OS FURTHER EAST. SHOWER ACTIVITY WILL INCREASE ON THURSDAY AS A DEEP LOW PRESSURE SYSTEM PASSES ACROSS THE WESTERN GREAT LAKES...DRAGGING A STRONG COLD FRONT EAST FROM THE MISSISSIPPI RIVER VALLEY. STUCK CLOSER TO THE NAM/ECMWF/CANADIAN MODEL SOLUTIONS RELATIVE TO TIMING OF THE MORE WIDESPREAD SHOWER ACTIVITY...ALL OF WHICH FAVOR HEAVIER RAINFALL ENTERING THE MOUNTAINS DURING THE EVENING. THE UPPER RIDGE AXIS IS EXPECTED TO BE SITUATED ALONG THE APPALACHIAN CHAIN THURSDAY AFTERNOON...AND WHEN FACTORING IN A DELAYED ONSET TO WIDESPREAD RAINFALL...BELIEVE THAT THURSDAY WILL BE THE WARMEST DAY FOR MOST AREAS...LIKELY ONLY A DEGREE OR TWO OVER WEDNESDAY`S HIGHS HOWEVER. SHOWER ACTIVITY IS EXPECTED TO BECOME WIDESPREAD DURING THE EARLY HOURS OF FRIDAY. MODELS CONTINUE TO SUGGEST LOW CAPE/INSTABILITY AS THE SUPPORTING UPPER LEVEL TROUGH MOVES ACROSS FROM THE WEST...BUT VERY HIGH SHEAR AND HELICITY AS A 50KT TO 60KT LOW LEVEL JET DEVELOPS. BELIEVE THESE CONDITIONS WILL SUPPORT MAINLY STRONG SHOWERS WITH ONLY MINIMAL LIGHTNING...BUT THAT THE STRONGER SHOWERS WILL BE CAPABLE OF DRAWING SOME OF THE STRONGER WINDS ALOFT DOWN TO THE SURFACE...RESULTING IN GUSTY AND LOCALLY DAMAGING WINDS. THE HIGH SHEAR AND HELICITY ALSO MEAN THAT ISOLATED AND SHORT LIVED TORNADOES WILL BE POSSIBLE. AREAS ALONG AND EAST OF THE BLUE RIDGE WILL HAVE A BETTER THREAT FOR SEVERE WEATHER...AS THE SMOOTHER TERRAIN WILL ALLOW FOR BETTER ORGANIZATION OF CONVECTION. IN ADDITION...IF TIMING OF THE UPPER TROUGH IS DELAYED ANY...DAYTIME HEATING MAY ENHANCE THE CONVECTION ACROSS THE PIEDMONTS. HEAVIEST RAINFALL WILL MOVE EAST OF OUR AREA BY EARLY AFTERNOON ON FRIDAY...WITH LINGERING SHOWER ACTIVITY EXPECTED THROUGH EVENING. MILD AIR WILL REMAIN OVER OUR AREA THROUGH FRIDAY NIGHT...WITH THE TRULY COLDER AIR NOT EXPECTED TO ARRIVE UNTIL AFTER SUNRISE SATURDAY. && .LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 100 PM EDT MONDAY... ON SATURDAY...WINDS WILL BECOME INCREASINGLY NORTHWESTERLY IN THE WAKE OF THE DEPARTING COLD FRONT. THIS WILL ALLOW FOR GOOD DOWNSLOPE CLEARING OF SKIES EAST OF THE CREST OF THE BLUE RIDGE. ACROSS THE MOUNTAINS...THE FLOW WILL BE UPSLOPE AND EXPECT THE DEVELOPMENT OF THE RAIN/SNOW SHOWERS ACROSS THE PREFERRED UPSLOPE REGIONS OF MAINLY SOUTHEAST WEST VIRGINIA...ACCOMPANYING COUNTIES OF SOUTHWEST VIRGINIA...AND THE NORTHERN MOUNTAINS OF THE NORTH CAROLINA. FLURRIES OR SPRINKLES WILL CARRY DOWNSTREAM OF THE MAIN ACTIVITY TO AROUND THE CREST OF THE BLUE RIDGE AND THE NORTH CAROLINA FOOTHILLS. THIS PATTERN WILL CONTINUE THROUGH AT LEAST SUNDAY...WITH GRADUALLY DECREASING COVERAGE OF THE SHOWER ACTIVITY AS 850 MB WINDS WEAKEN AND VEER NORTH TO NORTHEAST. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 137 PM EDT TUESDAY... SCT TO BKN MVFR CLOUDS THIS AFTERNOON INTO TONIGHT. ANOTHER SHORTWAVE TRACKS NORTH OF THE UPPER RIDGE AND REACHES THE CENTRAL APPALACHIANS TONIGHT. TAF SITES IN THE MOUNTAINS WILL LOWER TO MVFR AFTER 05Z/1AM WITH THIS SHORTWAVE. OVERNIGHT INTO WEDNESDAY MORNING EXPECTED MVFR CEILING WITH POCKETS OF IFR IN LOW CLOUDS...FOG AND LIGHT RAIN. MEDIUM CONFIDENCE IN CIGS THROUGH TAF PERIOD. MEDIUM CONFIDENCE IN VSBYS THROUGH TAF VALID PERIOD. HIGH CONFIDENCE IN WIND SPD/DIR THROUGH TAF VALID PERIOD. MVFR-VFR CONDITIONS ARE EXPECTED WEDNESDAY AND THURSDAY WITH EXTENSIVE MID/HIGH CLOUDS. CANNOT RULE OUT OCCASIONAL -SHRA IN ADVANCE OF A STRONG FRONT THURSDAY...BUT THE MAIN BAND OF PRECIPITATION WILL COME THURSDAY NIGHT/FRIDAY WITH HEAVY RAIN SHOWERS AND GUSTY WINDS AND POTENTIAL FOR LOW-LEVEL WIND SHEAR. THIS WILL BRING AT LEAST BRIEF PERIODS OF IFR CIGS/VSYBS AS WELL. IN THE WAKE OF THE COLD FRONT...LOOK FOR INCREASING NORTHWEST FLOW BEHIND THE SURFACE SYSTEM. THIS WILL RESULT IN UPSLOPE RAIN/SNOW SHOWERS ACROSS THE PREFERRED UPSLOPE REGIONS OF SOUTHEAST WEST VIRGINIA SATURDAY INTO SUNDAY ALONG WITH IFR-MVFR CEILINGS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...NF LONG TERM...DS AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
352 PM MDT TUE OCT 29 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 345 PM MDT TUE OCT 29 2013 ANOTHER CHALLENGING FORECAST FOR TONIGHT SINCE TEMPERATURES TODAY DID NOT WARM UP AS MUCH AS PREVIOUSLY THOUGHT. CURRENT SATELLITE LOOP SHOWS FOG AND LOW STRATUS ARE STILL PRESENT ACROSS PORTIONS OF EXTREME SOUTHEAST WYOMING AND MOST OF WESTERN NEBRASKA. TEMPERATURES JUMPED INTO THE 40S WEST OF THE LARAMIE RANGE...BUT HAVE STRUGGLED TO REACH THE MIDDLE 30S EAST OF THE LARAMIE RANGE. MODELS AND WATER VAPOR LOOP SHOW THE NEXT UPPER LEVEL DISTURBANCE ROUNDING THE BASE OF THE MAIN UPPER LEVEL LOW OVER THE GREAT BASIN. THIS DISTURBANCE IS EXPECTED TO IMPACT SOUTHEAST WYOMING AND PORTIONS OF WESTERN NEBRASKA TONIGHT RESULTING IN THE POTENTIAL OF ANOTHER WINTRY MIX ACROSS THE HIGH PLAINS. CURRENT SOUNDINGS HAVE STRUGGLED TO SHOW PRESENT CONDITIONS TODAY...WITH THE NAM BUFR SOUNDINGS COMING THE CLOSEST TO INITIAL CONDITIONS. EXPECT A PERIOD OF FREEZING FOG AND PATCHY FREEZING DRIZZLE LATE THIS EVENING EAST OF A DOUGLAS TO CHEYENNE LINE AHEAD OF THIS UPPER LEVEL DISTURBANCE. NAM SOUNDINGS SHOW NEAR OR SLIGHTLY BELOW FREEZING TEMPERATURES AT THE SURFACE EAST OF THE LARAMIE RANGE WITH NEARLY ISOTHERMAL TEMPERATURES UP TO 700MB...OR WARMING SLIGHTLY. ONCE THE AXIS OF THIS SHORTWAVE DISTURBANCE MOVES INTO THE AREA...EXPECT LIGHT FREEZING RAIN/SLEET/SNOW MIX TO DEVELOP...TRENDING TOWARDS SLEET AND SNOW MIX BY EARLY WEDNESDAY MORNING AS THE TEMPERATURES LOWER BELOW 0C ALOFT. FOR THE MOUNTAINS AND HIGHER RIDGES...INCLUDING LARAMIE AND CHEYENNE...LITTLE ICE OR FREEZING DRIZZLE IS EXPECTED WITH MORE OF A RAIN/SNOW MIX INITIALLY CHANGING TO ALL SNOW. WILL HAVE TO KEEP AN EYE ON THE I80 CORRIDOR TOWARDS THE NEBRASKA BORDER FOR SNOW ACCUMULATIONS OVER 3 INCHES SINCE MODELS CONTINUE TO INDICATE SOME ELEVATED INSTABILITY AS THE COLD AIR ALOFT MOVES INTO THE REGION. IN FACT...A FEW LIGHTNING STRIKES HAVE BEEN OBSERVED WITH THIS SHORTWAVE DISTURBANCE ACROSS SOUTHWEST COLORADO. FURTHER NORTH...EXPECT SOME ICE AND SNOW ACCUMULATION...AND ISSUED A WINTER WEATHER ADVISORY FOR A WINTRY MIX...NORTHEAST OF A WHEATLAND TO ALLIANCE LINE. EXPECT ICE ACCUMULATIONS AROUND ONE TENTH TO TWO TENTHS OF AN INCH IN THESE LOCATIONS WITH SNOW ACCUMULATIONS WEDNESDAY MORNING UP TO AN INCH. UPPER LEVEL DISTURBANCE QUICKLY MOVES NORTHEAST INTO THE DAKOTAS BY LATE WEDNESDAY MORNING WITH SUBSIDENCE AND DRIER CONDITIONS EXPECTED WEDNESDAY AFTERNOON AS WINDS SHIFT INTO THE WEST. THE NEXT FORECAST CONCERN WILL BE STRONG WINDS WEDNESDAY NIGHT AND THURSDAY AS THE PRESSURE GRADIENT STRENGTHENS ACROSS SOUTHEAST WYOMING. ISSUED A HIGH WIND WATCH BEGINNING MIDNIGHT LATE WEDNESDAY NIGHT FOR THE WIND PRONE AREAS ALONG I80 BETWEEN LARAMIE AND CHEYENNE INCLUDING THE I80 SUMMIT...AND THE ARLINGTON EXCHANGE WEST OF LARAMIE. GUSTS AROUND 60 MPH ARE EXPECTED IN THESE LOCATIONS BY EARLY THURSDAY MORNING. WINDS WILL INCREASE OUT OF THE NORTHWEST EVERYWHERE BY NOON THURSDAY AS LLVL MIXING OCCURS...WHERE WINDS MAY GUST AS HIGH AS 50 MPH OUTSIDE OF THE WATCH AREA. MAY NEED A WIND ADVISORY FOR PORTIONS OF NEBRASKA THURSDAY AFTERNOON WITH MOS GUIDANCE SHOWING SUSTAINED WINDS BETWEEN 25 TO 35 MPH. POP WILL BE BELOW 5 PERCENT ACROSS MOST OF THE FORECAST AREA OUTSIDE OF THE MOUNTAINS ON THURSDAY...BUT UPSLOPE FLOW WILL CONTINUE OVER THE MOUNTAINS WHERE 1 TO 3 INCHES OF SNOW MAY ACCUMULATE IN THE SNOWY AND SIERRA MADRE RANGES. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 330 AM MDT TUE OCT 29 2013 HIGH WINDS LOOK TO BE CONTINUING THE BEGINNING OF THE LONG TERM AS GFS SHOWING 700MB WINDS 50+ KTS OVER SOUTHERN WYOMING. WINDS WILL BE EASING DURING THE OVERNIGHT HOURS INTO FRIDAY MORNING...DOWN TO AROUND 35KTS BY 12Z FRIDAY. NORTHWEST FLOW FOR FRIDAY WITH FAIRLY COOL TEMPERATURES. 700MB TEMPERATURES -4 TO -6C SHOULD EQUATE TO 40 HIGHS OUT WEST. WITH A DOWNSLOPING COMPONENT THOUGH...AREAS EAST OF THE LARAMIE RANGE SHOULD MAKE IT INTO THE 50S FRIDAY AFTERNOON. BRIEF WARM UP FOR THE WEEKEND AS 700MB TEMPERATURES CLIMB BACK ABOVE FREEZING...UP TO +4 TO +6C SATURDAY INTO SUNDAY. LOOKING AT VERY NICE TEMPERATURES BOTH DAYS...60S EAST OF THE LARAMIE RANGE...50S WEST. WARM CONDITIONS WILL BE TEMPORARY THOUGH AS OUR NEXT PACIFIC STORM SYSTEM LOOKS TO MOVE INTO THE AREA SUNDAY NIGHT INTO MONDAY. 700MB TEMPERATURE FALL TO -8 TO -10C MONDAY AFTERNOON AS THE FRONT MOVES THROUGH THE AREA AND STALLS OVER NORTHERN COLORADO. BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT FOR WIDESPREAD PRECIP DEVELOPING INITIALLY OUT WEST OVER CARBON COUNTY...BUT SPREADING ACROSS THE ENTIRE CWFA BY MONDAY NIGHT. WITH THE COLD 700MB TEMPERATURES...THIS SHOULD ALL FALL AS SNOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING) ISSUED AT 1104 AM MDT TUE OCT 29 2013 TOUGH FORECAST FOR THE SOUTHEAST WYOMING AND NEBRASKA PANHANDLE AIRPORTS TODAY. RELYING HEAVILY ON LATEST HRRR FORECAST THAT BREAKS OUT CHEYENNE AND THE SOUTHERN PANHANDLE LATE THIS AFTERNOON FOR A BRIEF TIME. FOR CHADRON AND ALLIANCE...THINK THESE AIRPORTS WILL STAY DOWN ALL DAY. ALL AIRPORTS EAST OF THE LARAMIE RANGE WILL GO DOWN ONCE AGAIN THIS EVENING AS UPPER LOW EJECTS SOME ENERGY EAST. CONFIDENCE HIGH ON THIS HAPPENING. SHOULD SEE A RETURN TO VFR CONDITIONS FROM WEST TO EAST LATE WEDNESDAY MORNING. && .FIRE WEATHER... ISSUED AT 300 PM MDT TUE OCT 29 2013 WITH WINTRY WEATHER AND COOL TEMPERATURES EXPECTED THIS WEEK...AND AGAIN EARLY NEXT WEEK...NO FIRE WEATHER CONCERNS ARE ANTICIPATED. TEMPERATURES WILL GRADUALLY MODERATE LATE THIS WEEK WITH INCREASING WINDS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON MDT WEDNESDAY FOR WYZ102-107-108. HIGH WIND WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY AFTERNOON FOR WYZ110-116-117. NE...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON MDT WEDNESDAY FOR NEZ002-003-019-095-096. && $$ SHORT TERM...TJT LONG TERM...CLAYCOMB AVIATION...CLAYCOMB FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1109 AM MDT TUE OCT 29 2013 .UPDATE... ISSUED AT 951 AM MDT TUE OCT 29 2013 UPDATED FORECAST THROUGH TONIGHT WITH ONLY MINOR CHANGES TODAY. FORECAST FOR TODAY LOOKS ON TRACK WITH FOG AND FREEZING DRIZZLE CONTINUING LATE THIS MORNING. LOW STRATUS AND FOG IS TAKING ITS TIME LIFTING...SO LOWERED HOURLY TEMPERATURES BY 3-5 DEGREES THROUGH 3 PM THIS AFTERNOON. WILL CONTINUE WITH THE FREEZING RAIN ADVISORY UNTIL NOON WITH SEVERAL REPORTS ACROSS THE AREA OBSERVING ICE ACCUMULATIONS UP TO A QUARTER INCH FROM LARAMIE COUNTY NORTHEAST TO NORTHWEST NEBRASKA. EXPECT FOG TO GRADUALLY LIFT THIS AFTERNOON WITH SOME SUNSHINE EXPECTED...WHICH WILL MELT MOST OF THE ICE INTO THIS EVENING. ATTENTION THEN SHIFTS TO THE POTENTIAL FOR SNOW TONIGHT AS A POTENT SHORTWAVE...CURRENTLY OVER SOUTHERN NEVADA AND CALIFORNIA...EJECTS NORTHEASTWARD OVER SOUTHEAST WYOMING AND MAYBE WESTERN NEBRASKA. MODELS HAVE NOT BEEN CONSISTENT WITH THE PLACEMENT OF THIS FEATURE AND ASSOCIATED PRECIPITATION. DID INCREASE POP TONIGHT EAST OF A LINE FROM LARAMIE TO CHADRON. THERE IS THE POTENTIAL OF LIGHT TO MODERATE SNOW ACCUMULATIONS...BUT SNOW LEVEL WILL BE RELATIVELY HIGH...AROUND 6000 TO 7000 FEET. && .SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT) ISSUED AT 345 AM MDT TUE OCT 29 2013 PREDAWN WATER VAPOR SATELLITE IMAGERY SHOWED THE PACIFIC UPPER LOW CENTER HAD MOVED EAST INTO NORTHERN NEVADA WITH BROAD DIFFLUENT FLOW ALOFT FROM THE FOUR CORNERS THROUGH THE CENTRAL ROCKIES AND GREAT PLAINS. THE REGIONAL SURFACE ANALYSIS DEPICTED A STATIONARY FRONT FROM CENTRAL IDAHO THROUGH SOUTHWEST WYOMING... ALONG THE COLORADO FRONT RANGE TO THE SOUTH CENTRAL HIGH PLAINS. NORTH OF THIS BOUNDARY...A SHALLOW COLD AIR MASS WAS ENTRENCHED ACROSS THE CWA. WARM MOIST AIR OVERRUNNING THE COLD AIR ALOFT AND UPSLOPE LOW LEVEL FLOW WAS CREATING WIDESPREAD FOG...LIGHT FREEZING DRIZZLE AND SNOW. ICE ACCUMULATIONS HAVE BEEN LIGHT THUS FAR...BUT ARE CAUSING HAZARDOUS DRIVING CONDITIONS DUE TO BLACK ICE. SURFACE TEMPERATURES REMAINED STEADY IN THE 20S. VISIBILITIES IN FOG GENERALLY RANGED FROM 1 TO 5 MILES...BUT WERE AS LOW AS A QUARTER MILE ACROSS THE SOUTHERN LARAMIE RANGE WHERE A DENSE FOG ADVISORY REMAINS IN EFFECT UNTIL 6 AM. THE 00Z SHORT RANGE MODEL GUIDANCE IS IN GOOD AGREEMENT PROGGING THE NEVADA UPPER LOW TO MOVE NORTHEAST INTO WYOMING TONIGHT AND THE DAKOTAS ON WEDNESDAY. SYNOPTIC SCALE LIFT ASSOCIATED WITH THE ACCOMPANYING TROUGH WILL ENHANCE THE PRECIPITATION TONIGHT AND WEDNESDAY. FREEZING DRIZZLE MIXED WITH SNOW WILL PREVAIL THIS MORNING EAST OF THE LARAMIE RANGE...THEN CHANGE TO RAIN OR RAIN MIXED WITH SNOW THIS AFTERNOON AS TEMPERATURES RISE ABOVE FREEZING. AS THE UPPER LOW MOVES INTO WYOMING TONIGHT...COLDER AIR ALOFT WILL CHANGE THE MIXED PRECIPITATION TO SNOW. SNOW ACCUMULATIONS WILL RANGE FROM A HALF INCH FOR THE PLAINS TO MUCH AS 3 INCHES FOR THE SNOWY AND SIERRA MADRE RANGES. THE SNOW WILL LINGER THROUGH WEDNESDAY NIGHT WITH AN ADDITIONAL 1 TO 3 INCHES FOR THE SOUTHERN MOUNTAINS. LIGHT RAIN OR RAIN MIXED WITH SNOW IS EXPECTED FOR LOWER ELEVATIONS WEDNESDAY. WEST WINDS WILL BEGIN TO INCREASE WEDNESDAY AFTERNOON WEST OF THE LARAMIE RANGE AND SPREAD EAST INTO SOUTHEAST WYOMING WEDNESDAY NIGHT. TEMPERATURES DURING THE SHORT TERM PERIOD WILL AVERAGE BELOW SEASONAL NORMALS. HIGHS TODAY WILL RANGE FROM THE 20S MOUNTAINS... TO THE 30S TO MID 40S VALLEYS AND PLAINS. LOWS TONIGHT WILL RANGE FROM AROUND 20 MOUNTAINS TO THE LOWER AND MID 30S PLAINS. HIGHS WEDNESDAY WILL BE ABOUT 5 DEGREES MILDER FOR THE PLAINS WITH 40S TO AROUND 50. LOWS WEDNESDAY NIGHT WILL BE SIMILAR TO TONIGHT/S MINIMA. .LONG TERM...(THURSDAY THROUGH MONDAY NIGHT) ISSUED AT 345 AM MDT TUE OCT 29 2013 MODELS CONTINUE TO SHOW A GAP WIND EVENT SETTING UP FOR THURSDAY AS NW FLOW ALOFT INCREASES...AND HIGH PRESSURE BUILDS IN FROM THE WEST BOTH ALOFT AND AT THE SURFACE. THE LOW LEVEL GRADIENT WILL INCREASE THURSDAY MORNING WITH THE APPROACHING HIGH...PROMOTING AN INCREASE IN WESTERLY GRADIENT WINDS ACROSS THE FORECAST AREA. MID LEVEL WARM AIR ADVECTION WILL STRENGTHEN THE INVERSION BETWEEN 600 AND 700 MB...IN ESSENCE TRAPPING THE INCREASING GRADIENT FLOW NEAR THE SURFACE. IN THE HIGH COUNTRY...700 MB WINDS JUST BELOW THE INVERSION LOOK TO INCREASE TO AROUND 50 KT DUE TO THE ACCELERATION OF TRAPPED FLOW BETWEEN THE MOUNTAINS AND INVERSION. LOOKING AT SURFACE WINDS GUSTING AROUND 60 MPH IN THESE GAP AREAS ALONG AND WEST OF THE LARAMIE RANGE...IN ADDITION TO THE HIGHER MOUNTAIN PEAKS THROUGH THE MORNING AND EARLY AFTERNOON UNTIL THE INVERSION WEAKENS. GUSTS AROUND 50 MPH LOOK TO OCCUR IN THE PLAINS TO THE IMMEDIATE EAST OF THE LARAMIE RANGE...AND WILL ALSO SEE BREEZY CONDITIONS ELSEWHERE ACROSS WYOMING AND THE WESTERN NEBRASKA PANHANDLE DUE TO THE GENERAL INCREASING GRADIENT FLOW. THURSDAYS TEMPS WILL BE ON THE RISE AS A RESULT OF WARM AIR ADVECTION AND DOWNSLOPE WARMING...WITH 50S TO 60S LIKELY ACROSS THE EASTERN PLAINS AND 40S OUT WEST. WOULD EXPECT SOME MOUNTAIN WAVE CLOUDS AS WELL IN THIS PATTERN AND A FEW LIGHT OROGRAPHIC RAIN/SNOW SHOWERS IN THE SNOWY AND SIERRA MADRE MOUNTAINS. A SOMEWHAT DISORGANIZED SHORTWAVE WILL MOVE ACROSS THE FORECAST AREA THURSDAY NIGHT IN NW FLOW...ALONG WITH INCREASING MID LEVEL MOISTURE. UPPER LEVEL FORCING LOOKS RELATIVELY WEAK WITH THIS FEATURE...SO ANTICIPATE MAINLY OROGRAPHIC SHOWERS TO BE ENHANCED BY THE WAVE WITH A FEW SNEAKING OFF THE MOUNTAINS AND INTO THE IMMEDIATE EASTERN PLAINS THROUGH FRIDAY MORNING. LITTLE TO NO ACCUMULATION WILL OCCUR OVER THE PLAINS AND HIGH VALLEYS...WITH A FEW INCHES POSSIBLE IN THE MOUNTAINS. THE UPPER RIDGE WILL BUILD OVERHEAD FRIDAY AND SATURDAY WITH MILD AND MAINLY DRY CONDITIONS EXPECTED LATE FRIDAY THROUGH SATURDAY. THE NEXT UPPER TROUGH WILL MOVE TOWARD THE FORECAST AREA SATURDAY NIGHT AND SUNDAY AND WILL BACK UPPER LEVEL FLOW TO THE SOUTHWEST. THE LEE SIDE PRESSURE TROUGH WILL DEEPEN IN ADVANCE OF THIS WAVE SO WILL SEE BREEZY SOUTHWEST WINDS ACROSS THE AREA THROUGH MUCH OF THE WEEKEND. A COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL MOVE THROUGH THE AREA LATE IN THE WEEKEND AND WILL BRING A RETURN OF MUCH COOLER TEMPS AND SNOW FOR THE BEGINNING OF THE WEEK. WILL MAINTAIN LOW END CHANCES FOR SNOW AS MODELS CONTINUE TO SHOW SOME STRENGTH AND TIMING DIFFERENCES WITH THE UPPER TROUGH. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING) ISSUED AT 1104 AM MDT TUE OCT 29 2013 TOUGH FORECAST FOR THE SOUTHEAST WYOMING AND NEBRASKA PANHANDLE AIRPORTS TODAY. RELYING HEAVILY ON LATEST HRRR FORECAST THAT BREAKS OUT CHEYENNE AND THE SOUTHERN PANHANDLE LATE THIS AFTERNOON FOR A BRIEF TIME. FOR CHADRON AND ALLIANCE...THINK THESE AIRPORTS WILL STAY DOWN ALL DAY. ALL AIRPORTS EAST OF THE LARAMIE RANGE WILL GO DOWN ONCE AGAIN THIS EVENING AS UPPER LOW EJECTS SOME ENERGY EAST. CONFIDENCE HIGH ON THIS HAPPENING. SHOULD SEE A RETURN TO VFR CONDITIONS FROM WEST TO EAST LATE WEDNESDAY MORNING. && .FIRE WEATHER... ISSUED AT 238 AM MDT TUE OCT 29 2013 UPPER LEVEL LOW PRESSURE OVER NEVADA WILL MOVE INTO WYOMING TONIGHT. THIS LOW WILL BRING WIDESPREAD LIGHT RAIN...DRIZZLE AND SNOW TO THE DISTRICTS TODAY THROUGH WEDNESDAY. COLD TEMPERATURES AND HIGH RELATIVE HUMIDITIES WILL PRECLUDE FIRE WEATHER CONCERNS. AS THE LOW EXITS TO THE EAST LATE WEDNESDAY AND THURSDAY...SUSTAINED WESTERLY WINDS OF 25 TO 35 MPH WITH GUSTS TO 50 MPH WILL BE POSSIBLE FOR THE WIND PRONE AREAS OF SOUTHEAST WYOMING. DRIER AND MILDER CONDITIONS WILL RETURN LATER THIS WEEK AND LAST THROUGH THE WEEKEND. A CHANGE TO COLDER AND WETTER CONDITIONS IS EXPECTED FOR EARLY NEXT WEEK. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...TJT SHORT TERM...JAMSKI LONG TERM...RJM AVIATION...CLAYCOMB FIRE WEATHER...JAMSKI