Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/07/14


AREA FORECAST DISCUSSION...UPDATED
NWS SAN DIEGO CA
634 PM PDT TUE MAY 6 2014 .UPDATE... UPDATED THE FORECAST FOR THE EXPIRATION OF THE WIND ADVISORY FOR THE VALLEYS AND COAST. THE REMAINDER OF THE PREVIOUS FORECAST IS ON TRACK. ISOLATED TO SCATTERED RAIN AND MOUNTAIN SNOW SHOWERS OVER THE MOUNTAINS AND FAR INLAND VALLEYS WILL BE POSSIBLE THROUGH TONIGHT AS AN UPPER-LEVEL TROUGH CONTINUES ACROSS THE REGION. ONLY LIGHT ACCUMULATIONS OF RAIN IS FORECAST...EXCEPT IN HEAVIER SHOWERS WHERE AROUND ONE-QUARTER INCH IS POSSIBLE. A TRACE TO A FEW INCHES OF SNOW IS POSSIBLE ABOVE 5500 FT. THE HIGH WIND WARNING FOR THE SAN DIEGO AND RIVERSIDE COUNTY MOUNTAINS AND DESERTS...ALONG WITH THE WIND ADVISORY FOR THE SAN BERNARDINO COUNTY MOUNTAINS AND DESERTS...REMAINS IN EFFECT. && .SYNOPSIS... A LOW PRESSURE TROUGH MOVING THROUGH SOUTHERN CALIFORNIA WILL CONTINUE STRONG AND GUSTY WEST WINDS IN THE MOUNTAINS AND DESERTS THROUGH TONIGHT. LIGHT PRECIPITATION IS POSSIBLE ALONG AND WEST OF THE MOUNTAINS...WITH BEST CHANCES FOR PRECIPITATION ALONG THE COAST SLOPES. INCREASED INSTABILITY MAY CREATE ISOLATED THUNDERSTORMS THIS EVENING OVER THE NORTHERN AREAS. A FEW INCHES OF SNOW MAY ACCUMULATE ABOVE 6500 FEET IN HEAVIER SHOWERS. A WARMING AND DRYING TREND WILL FOLLOW FOR WEDNESDAY THROUGH SUNDAY AS HIGH PRESSURE GRADUALLY BUILDS ALOFT. THIS WILL RESULT IN A GRADUALLY SHALLOWER MARINE LAYER AS WELL. GUSTY OFFSHORE FLOW AND CONTINUED WARMING POSSIBLE FOR MONDAY. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... PREVIOUS DISCUSSION... GUSTY WESTERLY WINDS WILL CONTINUE THROUGH EARLY EVENING OVER THE MOUNTAINS AND DESERTS AS HIGH-RES MODELS SHOW MOUNTAIN WAVES REDEVELOPING. WINDS WILL BE SLIGHTLY LESS WINDY OVER THE MOUNTAINS AND DESERTS OF SAN BERNARDINO COUNTY...AS THOSE MOUNTAINS ARE ORIENTED WEST TO EAST...WHICH IS LESS FAVORABLE FOR MOUNTAIN WAVES FROM PREDOMINANTLY WESTERLY FLOW. A WIND ADVISORY CONTINUES FOR THOSE AREAS. ISOLATED TO SCATTERED SHOWERS ARE LIKELY TO INCREASE IN COVERAGE THROUGH EARLY EVENING AS THE CORE OF THE TROUGH MOVES OVER THE AREA ALONG WITH AN ASSOCIATED VORT MAX. THE HRRR SEEMS TO HAVE A GOOD HANDLE ON THE CURRENT PRECIPITATION. THE LOCAL WRF CONTINUES TO NOT SHOW TOO MUCH IN THE WAY OF PRECIPITATION OVERALL COMPARED TO THE CANSAC WRF...BUT IT DOES SHOW THE POTENTIAL FOR SOME ISOLATED HEAVIER SHOWERS EARLY THIS EVENING OVER THE MOUNTAINS. WITH THE COLD CORE OF THE TROUGH EXPECTED TO DROP DOWN OVER THE AREA LATER TODAY BRINGING INCREASED INSTABILITY...WILL CONTINUE A SLIGHT CHANCE OF THUNDERSTORMS TO THE NORTHERN SECTIONS OF THE FORECAST AREA THROUGH MID EVENING. CURRENT SNOW LEVELS ARE AT AROUND 5500 TO 6000 FEET...AND AREAS ABOVE 6500 FEET COULD SEE A COUPLE INCHES OF TOTAL SNOWFALL. WINDS WILL DIMINISH LATE TONIGHT THROUGH WEDNESDAY AS THE TROUGH MOVES OFF TO THE EAST. FOR WEDNESDAY THROUGH SUNDAY...WARMING AND DRYING WILL OCCUR UNDER DRY NORTHWEST FLOW ALOFT AND HIGHER 500 MB HEIGHTS. THE MARINE LAYER SHOULD ALSO BECOME GRADUALLY SHALLOWER...WITH NIGHT AND MORNING STRATUS CONFINED MAINLY TO THE COAST AND WESTERN VALLEYS BY SATURDAY NIGHT. WARMING IS LIKELY TO CONTINUE INTO SUNDAY...AND WE MAY GET GUSTY OFFSHORE FLOW LATE SUNDAY INTO MONDAY ACCORDING TO THE ECMWF. BY MONDAY...DAY-TIME HIGHS MAY REACH SEVERAL DEGREES ABOVE NORMAL. && .AVIATION... 062000Z...COAST/VALLEYS...MULTIPLE SCT-BKN STRATUS LAYERS BETWEEN 2000 FT MSL AND 6000 FT MSL WILL CONTINUE THIS EVENING WITH ISOLATED LIGHT RAIN SHOWERS. VSBY LOCALLY REDUCED TO 6SM IN SHOWERS. HIGHER TERRAIN WILL BE OBSCURED AT TIMES DUE TO THE LOW CLOUD DECK. A GUSTY WEST SFC WIND WILL DEVELOP THIS AFTERNOON INTO EARLY THIS EVENING GUSTS 20 TO 30 KNOTS THROUGH 07/0300Z. WINDS WILL DIMINISH AFTER 07/0300Z AND STRATUS BECOMING BKN-OVC WITH BASES 2000-2500 FT MSL AND TOPS 5000 FT MSL. STRATUS WILL SCATTER OUT AFT 07/1700Z. MTNS/DESERTS...AREAS OF SFC WIND GUSTS OVER 50 KNOTS IN ALONG NORTH-SOUTH MTN CRESTS AND ADJACENT DESERT SLOPES AND PASSES...WITH LOCAL 40 KNOT GUSTS IN SAN BERNARDINO MOUNTAINS PARTS OF THE HIGH DESERT. STG-SVR UDDFS AND LLWS OVER AND E OF THE MTNS POSSIBLE WITH THESE WINDS. VSBY LOCALLY REDUCED TO 3SM OR LESS IN BLDU. WINDS DIMINISHING THIS EVENING. && .MARINE... 100 PM...A TROUGH OF LOW PRESSURE MOVING THROUGH CALIFORNIA TODAY AND WEDNESDAY WILL PRODUCE WEST TO NORTHWEST WINDS 20-25 KT IN BOTH THE COASTAL WATERS WITH GUSTS AROUND 30 KT. GUSTS TO AROUND 35 KT POSSIBLE IN THE OUTER COASTAL WATERS...MAINLY THIS MORNING THROUGH THIS EVENING. WINDS WILL GRADUALLY WEAKEN TONIGHT AND WEDNESDAY MORNING. THESE STRONG WINDS AND A FRESH NORTHWEST SWELL WILL PRODUCE COMBINED SEAS NEAR 10 FEET AND VERY ROUGH CONDITIONS IN THE OUTER WATERS TODAY. THE SMALL CRAFT ADVISORY HAS BEEN UPGRADED TO A GALE WARNING FOR THE OUTER COASTAL WATERS. SEE LAXMWWSGX FOR INFO. && .SKYWARN... SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...HIGH WIND WARNING UNTIL 3 AM PDT WEDNESDAY FOR THE COACHELLA VALLEY...RIVERSIDE COUNTY MOUNTAINS...SAN DIEGO COUNTY DESERTS...SAN DIEGO COUNTY MOUNTAINS. WIND ADVISORY UNTIL 9 PM PDT THIS EVENING FOR THE APPLE AND LUCERNE VALLEYS...SAN BERNARDINO COUNTY MOUNTAINS. SMALL CRAFT ADVISORY UNTIL 3 AM PDT WEDNESDAY FOR THE SAN DIEGO COUNTY COASTAL AREAS. PZ...SMALL CRAFT ADVISORY FROM 3 AM TO 11 AM PDT WEDNESDAY FOR THE WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING 30 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND. GALE WARNING UNTIL 3 AM PDT WEDNESDAY FOR THE WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING 30 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND. SMALL CRAFT ADVISORY UNTIL 3 AM PDT WEDNESDAY FOR THE COASTAL WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER AND OUT 30 NM. && $$ PUBLIC...SH/JJT AVIATION/MARINE...JT
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
540 PM PDT TUE MAY 6 2014 .SYNOPSIS...SHOWERS WILL BE POSSIBLE THROUGH THE EARLY EVENING HOURS IN SAN BENITO COUNTY. SLIGHTLY COOLER THAN NORMAL TEMPERATURES ARE EXPECTED TO CONTINUE ACROSS THE AREA THROUGH AT LEAST MID WEEK. A WEAK COLD FRONT WILL BRING A SLIGHT CHANCE OF LIGHT RAIN OR DRIZZLE TO THE AREA THURSDAY. DRY AND WARMER WEATHER IS EXPECTED THIS WEEKEND THROUGH NEXT WEEK. && .DISCUSSSION...AS OF 2:46 PM PDT TUESDAY...CURRENTLY THE VISIBLE SATELLITE IMAGE IS SHOWING MOSTLY CLEAR SKIES AROUND THE SAN FRANCISCO BAY AREA WITH PARTLY TO MOSTLY CLOUDY SKIES OVER MONTEREY AND SAN BENITO COUNTIES. THE CUMULUS CLOUDS OVER SAN BENITO AND MONTEREY COUNTIES ARE DUE TO HEATING OF THE DAY AT THE SURFACE COMBINED WITH COOL AIR ALOFT ASSOCIATED WITH THE TROUGH OF LOW PRESSURE EXITING THE FORECAST AREA. HNX DOPPLER RADAR IS INDICATING SOME SHOWER ACTIVITY ALONG MUSTANG RIDGE AND THE CHALOME HILLS...JUST SOUTH OF SAN BENITO COUNTY. SHOWERS COULD ALSO BE OCCURRING IN THE SAN BENITO HILLS BUT RADAR BEAM BLOCKAGE COULD BE HIDING THESE SHOWERS. SHOWERS WILL TAPER OFF THIS EVENING AS HEATING OF THE DAY DISSIPATES AND THE AIRMASS STABILIZES. HAVE ADDED AN AREA OF SHOWERS TO THE FORECAST FOR SAN BENITO COUNTY AND SOUTHERN INTERIOR MONTEREY COUNTY VALID THROUGH LATE THIS EVENING. PROXIMITY SOUNDINGS PERFORMED WITH THE RUC13 MODEL LAUNCHED NEAR HERNANDEZ CONTINUE TO SHOW AN UNSTABLE ENVIRONMENT WITH LI VALUES AROUND -2.8 AND CAPE VALUES BETWEEN 200 AND 400 J/KG THIS AFTERNOON INTO THE EARLY EVENING HOURS. THE SOUNDINGS ARE INDICATING A DRY LAYER FROM 5000 FEET TO THE SURFACE SO MUCH OF THE PRECIPITATION WILL BE LIGHT IF NOT VIRGA. SURFACE ANALYSIS PERFORMED WITH THE 1800Z NAM12 AND 1200Z GFS40 CONTINUES TO INDICATE A WEAK COLD FRONT MOVING THROUGH THE AREA THURSDAY. LIGHT SHOWERS WILL BE POSSIBLE WITH THIS FRONT ESPECIALLY DURING THE LATE MORNING AND AFTERNOON HOURS. DRIZZLE WILL ALSO BE POSSIBLE WEDNESDAY NIGHT AT THE COAST AS THE MARINE LAYER DEEPENS AHEAD OF THE FRONT. THE 1200Z ECMWF AND GFS40 HAVE INITIALIZED WELL AND REMAIN IN GOOD AGREEMENT THROUGH AT LEAST SATURDAY. BOTH MODELS FORECAST A RIDGE OF HIGH PRESSURE OFF OF THE CALIFORNIA COAST WHICH SHOULD KEEP THE AREA DRY THIS WEEKEND THROUGH EARLY NEXT WEEK. THE ECMWF DOES FORECAST A TROUGH OF LOW PRESSURE DIVING INTO THE GREAT BASIN SATURDAY NIGHT EARLY SUNDAY MORNING HOWEVER THE GFS40 DOES NOT. IF THE ECMWF SOLUTION IS CORRECT THERE COULD BE GUSTY NORTH WINDS OVER THE NORTH AND EAST BAY HILLS SATURDAY NIGHT INTO SUNDAY. WILL HAVE TO KEEP AN EYE ON THIS TROUGH SINCE THESE NORTHERLY WINDS WILL FURTHER DRY OUT FUELS IN THE NORTH AND EAST BAY AREA. && .AVIATION...AS OF 5:40 PM PDT TUESDAY...GUSTY NW FLOW WILL CONTINUE IN TO THE EVENING. PRESENTLY THE ACV-SFO GRADIENT IS 6 MB AND THE SFO-SAC GRADIENT IS 3 MB. THE ACV-SFO GRADIENT WILL DRIFT DOWNWARD ONLY A LITTLE BIT THROUGH WED MORNING...REACHING 5 MB. THE SFO-SAC GRADIENT WILL DRIFT WEAKER VERY LATE TONIGHT THEN CLIMB BACK UP TO 4 MB WEDNESDAY AFTERNOON AND EVENING. VFR IS FORECAST. TEMPO MVFR IS POSSIBLE ON THE MONTEREY PENINSULA. VICINITY OF KSFO...VFR. STRONG AND GUSTY WEST WINDS CLOSE TO 40 KNOTS AT TIMES WILL CONTINUE THIS EVENING UNTIL ROUGHLY 9 PM. WINDS SHOULD SETTLE SOMEWHAT AFTER 9 PM BUT NOT ENTIRELY CONFIDENT ON THIS AS THE AIR MASS WILL STILL BE PLENTY WELL MIXED THROUGH LATE EVENING. AIRPORT WEATHER WARNING FOR WINDS CONTINUES THROUGH 9 PM LOCAL. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...BRIEF MVFR POSSIBLE THIS EVENING OTHERWISE VFR FORECAST FOR THE PERIOD. GUSTY WEST WINDS WILL DIMINISH LATER THIS EVENING. && .MARINE...AS OF 2:46 PM PDT TUESDAY...HIGH PRESSURE WILL PERSIST OVER THE EASTERN PACIFIC INTO TOMORROW MAINTAINING MODERATE NORTHWEST WINDS. THESE STRONG WINDS WILL PRODUCE STEEP FRESH SWELL. WINDS SUBSIDE DURING THE LATTER HALF OF THE WEEK. && .MTR WATCHES/WARNINGS/ADVISORIES... .TNGT...SCA...PT ARENA TO PT REYES 0-10 NM SCA...PT REYES TO PIGEON PT 0-10 NM SCA...PIGEON PT TO PT PINOS 0-10 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...PT ARENA TO PT REYES 10-60 NM SCA...PT REYES TO PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PINOS 10-60 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 11 PM SCA...SF BAY SOUTH OF THE BAY BRIDGE UNTIL 11 PM SCA...MONTEREY BAY UNTIL 11 PM && $$ PUBLIC FORECAST: LARRY AVIATION: CANEPA MARINE: MM VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
905 PM MDT TUE MAY 6 2014 .UPDATE... ISSUED AT 904 PM MDT TUE MAY 6 2014 EVENING SHOWERS AND THUNDERSTORMS DEVELOPED OVER BOULDER AND LARIMER COUNTIES AND THEN MOVED NORTHEAST ACROSS WELD COUNTY. THE LAST OF THESE SHOWERS ARE OVER NORTH-CENTRAL WELD COUNTY AND SHOULD DISSIPATE OR MOVE INTO THE NEBRASKA PANHANDLE BY 930 PM. THE SURFACE LOW PRESSURE AREA LINGERING OVER EASTERN COLORADO TONIGHT WILL HELP TO KEEP LOW LEVEL MOISTURE IN PLACE ACROSS THE PLAINS. EVENING MODELS CONTINUE TO SHOW AN UPPER DISTURBANCE MOVING OUT OF THE MOUNTAINS TOMORROW AFTERNOON WHICH WILL HELP ORGANIZE A ROUND OF SHOWERS AND THUNDERSTORMS ACROSS NORTHEAST COLORADO. THE LATEST RUNS OF THE RAP SHOW 2000+ JOULES OF CAPE ON THE PLAINS BY 18Z. WILL UPDATE THE FORECASTS TO INCLUDE HIGHER POPS ON THE PLAINS TOMORROW AFTERNOON AND EVENING. ALL INGREDIENTS SEEM LIKE THEY WILL BE IN PLACE TO PRODUCE SOME HEALTHY STORMS. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 352 PM MDT TUE MAY 6 2014 SOUTHWEST FLOW ALOFT OVER COLORADO AT THIS TIME WITH UPPER TROUGH ACROSS THE GREAT BASIN. STEADY STREAM OF MID AND HIGH LEVEL MOISTURE CONTINUES OVER AREA...BEGINNING TO SHOW SOME DECREASE. ACROSS PLAINS...EARLIER SURGE CREATED HAVOC WITH WINDS IN DENVER AREA. WINDS NOW TRENDING EAST SOUTHEAST MOST AREAS AS WEAK CYCLONE DEVELOPS NORTH OF DENVER. SOUTHERLY WINDS PREVAILING ALONG THE PALMER DIVIDE AND LINCOLN COUNTY. SURFACE DEWPOINTS INCREASED A BIT BEHIND SURGE WITH READINGS MAINLY IN THE 30S EXCEPT LOWER 50S NEAR THE WYOMING AND NEBRASKA BORDERS. AIRMASS DRIER ALONG THE PALMER DIVIDE WITH DEWPOINTS IN THE MID TEENS TO MID 20S. FIRE DANGER REMAINS ELEVATED ACROSS LINCOLN COUNTY WITH OCCASIONAL WIND GUSTS TO 25 MPH AND HUMIDITY READINGS IN THE LOW TEENS. AT THIS TIME...NO DEVELOPING STORMS OVER THE FAR NORTHEAST CORNER...BUT CAPES IN THIS AREA HAVE BEEN INCREASING. FOR TONIGHT...SOUTHWEST FLOW ALOFT TO CONTINUE. SHORT TERM MODELS INDICATE THE SURFACE CYCLONE MOVING EAST INTO WASHINGTON COUNTY THIS EVENING WITH NORTHERLY WINDS ALONG THE NORTHERN BORDER AND SOUTHWESTERLIES ELSEWHERE ACROSS THE PLAINS. DEEPER MOISTURE STILL EXPECTED ALONG THE NEBRASKA AND WYOMING BORDERS. WILL CONTINUE THE LOW POPS THIS AREA. ENOUGH SHEAR DURING THE EVENING FOR THE POSSIBILITY OF THUNDER. MAIN THREAT WILL BE GUSTY OUTFLOW WINDS. OTHERWISE...DRY CONDITIONS TO PREVAIL WITH INCREASING MID LEVEL MOISTURE. ON WEDNESDAY...UPPER TROUGH BEGINS MOVING TOWARD COLORADO WITH INCREASING ASCENT AND MOISTURE BY THE AFTERNOON. SHOULD BEGIN TO SEE SOME SHOWERS DEVELOPING ACROSS THE MOUNTAINS DURING THE MORNING HOURS ALONG WITH A FEW THUNDERSTORMS WITH A BETTER CHANCE OROGRAPHICS WEAK...BUT COLD ENOUGH SOME SNOW ABOVE 10000 FEET AGL ESPECIALLY IN THE MORNING WITH PERHAPS SOME LIGHT ACCUMULATION OVER THE PASSES. ACROSS THE PLAINS...BEST LIFT WILL BE ACROSS THE NORTHERN BORDER AND WILL KEEP SOME CHANCE OF SHOWERS NORTH OF DENVER AND AKRON. AIRMASS LOOKS UNSTABLE ENOUGH FOR A FEW STORMS. BY THE AFTERNOON...MODELS SHOW SURFACE CYCLOGENESIS OVER EAST CENTRAL COLORADO WITH SURFACE FRONT ACROSS THE NORTHERN BORDER. THIS FRONT EXPECTED TO SLIDE SOUTH THROUGH THE AFTERNOON. SHOULD SEE THE CHANCE OF SHOWERS AND THUNDERSTORMS SHIFT SOUTH THROUGH THE AFTERNOON. FORECAST SOUNDINGS INDICATED FAVORABLE SHEAR AND CAPES AROUND 1200 J/KG EAST OF A STERLING TO AKRON LINE AT 21Z. SHEAR WEAKER FURTHER WEST WITH LESS CAPE. APPEARS BEST CHANCE FOR SEVERE STORMS WILL BE ACROSS LOGAN...SEDGWICK AND PHILLIPS COUNTIES WITH HAIL AND WINDS THE MAIN THREAT. AIRMASS WILL REMAIN DRY ACROSS LINCOLN COUNTY WITH HUMIDITY READINGS IN THE LOW TEENS. THIS COMBINED WITH GUSTY SOUTHERLY WINDS WILL INCREASE THE FIRE DANGER. WILL HOIST A RED FLAG WARNING FOR LINCOLN COUNTY FROM NOON THROUGH 8PM. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 352 PM MDT TUE MAY 6 2014 MAIN CONCERN WILL BE SEVERE POTENTIAL ON THE NORTHEAST PLAINS WEDNESDAY EVENING AND PREIP TRENDS THROUGH WEDNESDAY NIGHT AND EARLY THURSDAY. SURFACE COLD FRONT WILL MOVE SOUTHWARD OVER THE NORTHEAST PLAINS WEDNESDAY EVENING WITH MAIN SEVERE THREAT ALONG THE FRONT WITH CONVERGENCE ZONE. NAM SHOWING SURFACE BASED CAPES FROM 1000-1500J/G ALONG WITH AMPLE SHEAR FOR THUNDERSTORMS AND SOME POSSIBLE SEVERE. MAIN THREAT WOULD BE HAIL AND EVEN A BRIEF TORNADO GIVEN CONVERGENCE ALONG THE FRONT. STRONG QG FORCING WILL ALSO BE OVER THE AREA IN ADVANCE OF THE UPPER TROF WHICH WILL SWING NORTHEAST FROM UTAH AND INTO NEBRASKA BY THURSDAY MORNING. STILL APPEARS THE NORTHERN SECTIONS WILL DO THE BEST WITH PRECIP AMOUNTS...WITH LESSER AMOUNTS FROM THE SOUTHERN FRONT RANGE AND DENVER SOUTHWARD THROUGH THE PALMER DIVIDE. MAIN CHANGES TO CURRENT FORECAST WAS TO INCREASE RAIN CHANCES TO LIKELY FOR WEDNESDAY NIGHT OVER THE NORTHEAST PLAINS. SOME SUBSIDENCE AND DRYING FOR THURSDAY WITH LESSER CHANCES OF RAIN. SOME DRYING AND WARMING FOR FRIDAY AND THE WEEKEND AS COLORADO WILL BE UNDER A NORTHWEST FLOW PATTERN. THERE WILL STILL BE LINGERING MOISTURE FOR ISOLATED LATE DAY SHOWERS AND THUNDERSTORMS. THE EUROPEAN AND GFS DIVERGE ON SOLUTIONS THIS WEEKEND AS THE EUROPEAN DEVELOPS A STRONGER TROF OVER THE GREAT BASIN WHILE THE GFS REMAINS IN A ZONAL FLOW PATTERN. FOR NOW WILL JUST KEEP POPS LOW UNTIL A MORE CONSISTENT SOLUTION DEVELOPS. HOWEVER IF THE EUROPEAN SOLUTION VERIFIES WILL NEED TO INCREASE CHANCES OF PRECIP FROM LATE IN THE WEEKEND THROUGH MONDAY. && .AVIATION...(FOR THE TAFS THROUGH 06Z WEDNESDAY EVENING) ISSUED AT 904 PM MDT TUE MAY 6 2014 SHOWER ACTIVITY TO THE NORTH OF DENVER HAS SENT NORTHERLY WINDS DOWN ACROSS THE METRO AREA AIRPORTS. THE PRESENCE OF THE SURFACE LOW IS GOING TO KEEP WINDS FROM RETURNING TO NORMAL DRAINAGE PATTERNS. IT IS UNCLEAR HOW MUCH STRATUS MAY DEVELOP TO THE NORTHEAST OF DENVER...BUT FOR NOW WILL NOT MENTION ANY LOWER CEILINGS IN THE TAFS. THIS MAY CHANGE AFTER FURTHERY EVALUATION OF THE EVENING MODEL RUNS. && .FIRE WEATHER... ISSUED AT 352 PM MDT TUE MAY 6 2014 AIRMASS WILL REMAIN DRY ACROSS LINCOLN COUNTY DURING THE AFTERNOON AND EARLY EVENING...WITH HUMIDITY READINGS DROPPING INTO THE LOW TEENS. THIS COMBINED WITH GUSTY SOUTHERLY WINDS OF 25 TO 30 MPH AND DRY FUELS WILL CREATE RED FLAG CONDITIONS THROUGH THE EARLY EVENING. WILL HOIST A RED FLAG WARNING FOR LINCOLN COUNTY FROM NOON THROUGH 8PM. WINDS ARE EXPECTED TO DECREASE DURING THE EVENING HUMIDITY READINGS INCREASING WHICH. && .HYDROLOGY... ISSUED AT 352 PM MDT TUE MAY 6 2014 SPRING FLOOD THREAT STILL LOW AT THIS TIME BUT SOME CREEKS ARE SHOWING A SLOW RISE IN THE PAST SEVERAL DAYS. THE UPCOMING TROF WILL COOL TEMPERATURES AND SLOW THE SNOWMELT A BIT FOR THURSDAY AND FRIDAY. WITH THE TROF PASSAGE MODELS ARE SHOWING SOME SIGNIFICANT QPF (.50-1" OF RAIN) ESPECIALLY OVER NORTHERN SECTIONS OF CWA...MAINLY LARIMER COUNTY AND STRETCHING EAST OVER THE PLAINS. GIVE COLDER TEMPERATURES AND SOME SNOW IN THE HIGHER FOOTHILLS DON`T SEE A HUGE INCREASE IN STREAM FLOWS FROM THIS STORM. && .BOU WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM NOON TO 8 PM MDT WEDNESDAY FOR COZ246-247. && $$ UPDATE...DANKERS SHORT TERM...D-L LONG TERM...ENTREKIN AVIATION...DANKERS FIRE WEATHER...D-L HYDROLOGY...ENTREKIN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1050 AM MDT MON MAY 5 2014 .UPDATE... ISSUED AT 1049 AM MDT MON MAY 5 2014 OVERALL..CURRENT FORECASTS LOOK REASONABLE. STILL FAIRLY EXTENSIVE WAVE CLOUD ACROSS MUCH OF THE FOOTHILLS...URBAN CORRIDOR AND ADJACENT PLAINS. AIRMASS SLIGHTLY COOLER ACROSS THE PLAINS WITH LESS WIND EXPECTED THIS AFTERNOON. BUT SHOULD BE ENOUGH MIXING DESPITE CLOUD COVER TO WARM TEMPERATURES TO NEAR 80 DEGREES ACROSS THE PLAINS. WILL INCREASE CLOUDS A BIT MORE...BASED ON THE LATEST SYNTHETIC SATELLITE DATA SHOWING AT LEAST PART OF THE WAVE CLOUD HANGING AROUND THROUGH THE DAY. ONLY PLANNING ON MAKING MINOR CHANGES TO TEMPS AT THIS TIME. && .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 340 AM MDT MON MAY 5 2014 HIGH CLOUDS WILL CONTINUE TO STREAM OVER COLORADO TODAY WHILE LOW LEVELS REMAIN DRY. SHALLOW PLAINS AIRMASS DID MAKE A BIT OF WESTWARD PROGRESS OVERNIGHT...BUT THIS SHOULD BE REVERSED BY EARLY AFTERNOON BETWEEN A SSE WIND AND MIXING ALONG THE EDGE OF THE COOLER AIR. STILL THINK IT WILL BE A BIT COOLER WITH HIGHER HUMIDITIES IN THE NORTHEAST CORNER...BUT NOT AS SHARP A DIFFERENCE AS YESTERDAY. SLIGHT COOLING AT LOW TO MID LEVELS SINCE YESTERDAY SHOULD RESULT IN SLIGHTLY LOWER HIGHS TODAY...AND THERE IS ALSO A BIT LESS WIND. ONLY MINOR ADJUSTMENTS TO THE FORECAST THIS MORNING...MOST NOTABLY TO INCREASE THE CLOUD COVER A BIT AGAIN. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 340 AM MDT MON MAY 5 2014 MODELS ARE ALL IN GENERAL AGREEMENT THAT THE FIRST HALF OF THE WEEK WILL FEATURE MODERATE SOUTHWEST FLOW ALOFT AHEAD OF A PACIFIC TROUGH MOVING OVER THE GREAT BASIN. THE TROUGH IS EXPECTED TO MOVE OVER COLORADO WEDNESDAY AND WEDNESDAY NIGHT WITH A GOOD CHANCE OF SHOWERS ACROSS THE FORECAST AREA DURING THOSE PERIODS. MODELS BEGIN TO DIVERGE AFTER THAT...BUT MOSTLY AGREE ON PUTTING COLORADO UNDER COOL...WEST-NORTHWEST FLOW ALOFT. THE UPPER TROUGH MOVING OVER THE STATE WEDNESDAY LOOKS LIKE IT WILL CARRY SOME PUNCH WITH IT...PRIMARILY OFF TO OUR EAST ON THURSDAY AFTERNOON. STILL THE COLD POOL ALOFT ACCOMPANYING THE BASE OF THE TROUGH WILL BE ENOUGH TO DE-STABILIZE THE AIRMASS AND CAUSE SHOWER ACTIVITY WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. PREVIOUS FORECAST PACKAGE HAD SCATTERED POPS ACROSS THE FORECAST AREA WHICH DID NOT NEED ANY ADJUSTMENT. TEMPERATURES WILL GO FROM WARMER THAN NORMAL ON TUESDAY TO MUCH COOLER THAN NORMAL ON THURSDAY...AS THE COLDEST AIR ALOFT IS MOVING OVER THE STATE. TEMPERATURES WILL THEN SLOWLY CLIMB BACK TO AROUND NORMAL OVER THE WEEKEND. SOME SHOWERS WILL ALSO CONTINUE DEVELOPING DURING THE AFTERNOONS LATE IN THE WEEK AS COOL TEMPERATURES AT MID AND UPPER LEVELS LINGER OVER THE ROCKY MOUNTAIN WEST. && .AVIATION...(FOR THE TAFS THROUGH 18Z TUESDAY MORNING) ISSUED AT 1049 AM MDT MON MAY 5 2014 CURRENT TAF TRENDS LOOK REASONABLE AT THIS TIME. SOUTHWESTERLY WINDS STILL EXPECTED TO SHIFT COUNTERCLOCKWISE TO THE SOUTHEAST THIS AFTERNOON...PERHAPS A BIT MORE EASTERLY AT KDEN. WINDS TO THEN BECOME SOUTHWEST THIS EVENING. LATEST MODELS ARE SHOWING SOME HINTS AT A DENVER CYCLONE DEVELOPING NORTH OF DENVER DURING THE AFTERNOON. BOTH THE RAP AND HRRR SHIFT THIS CYCLONE INTO EASTERN ADAMS COUNTY BY 22Z...BRINGING WESTERLY WINDS ACROSS KDEN. FOR NOW WILL KEEP SOUTHEASTERLIES AT KDEN THIS AFTERNOON AND CONTINUE TO MONITOR FOR ANY WESTERLY DEVELOPMENT. MID AND HIGH LEVEL MOISTURE OVER THE AREA...CEILINGS SHOULD REMAIN ABOVE 12000 FEET AGL. LIGHT SOUTHWEST WINDS EXPECTED TUESDAY...SPEEDS AROUND 8 KTS. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...D-L SHORT TERM...GIMMESTAD LONG TERM...DANKERS AVIATION...D-L
AREA FORECAST DISCUSSION
NWS TAUNTON MA
340 PM EDT MON MAY 5 2014 .SYNOPSIS... HIGH PRESSURE NORTH OF THE GREAT LAKES SLOWLY BUILDS INTO NEW ENGLAND THROUGH WED...PROVIDING DRY AND SEASONABLE WEATHER WITH MILD DAYS AND COOL NIGHTS. THEN A PERIOD OF UNSETTLED WET WEATHER IS EXPECTED FOR THE END OF THE WEEK INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... THROUGH 00Z...COLD POOL ALOFT PRODUCING MARGINAL INSTABILITY WITH ISOLD SHOWERS MOVING S ACROSS SE COASTAL MA AND E MA COASTAL WATER. STEEP MID LEVEL LAPSE RATES 7.0- 7.5 C/KM ACROSS E MA AND SBCAPES NEAR 250 J/KG. HRRR KEEPS THREAT OF ISOLD SHOWERS ACROSS EASTERN MA AND POSSIBLY INTO RI THROUGH THE AFTERNOON AND HAVE MAINTAINED SLIGHT CHC POPS. MAYBE AN ISOLD TSTM. CLEARING TREND TOWARD EVENING. TONIGHT...CLEARING SKIES EXPECTED THIS EVENING...BUT MODELS SHOW INCREASING MID LEVEL MOISTURE MOVING IN OVERNIGHT AHEAD OF NEXT SHORTWAVE. DIMINISHING WINDS THIS EVENING WILL PROVIDE A WINDOW FOR RADIATIONAL COOLING. USED A BLEND OF MOS AND BIAS CORRECTED GRIDS FOR MIN TEMPS...GENERALLY MID 30S TO LOWER 40S. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... TUESDAY... LOOKS LIKE A SIMILAR DAY TO TODAY AS MID LEVEL SHORTWAVE MOVES THROUGH WITH 500 MB TEMPS COOLING TO -25C. ENOUGH MOISTURE IN THE COLUMN FOR ABUNDANT CU/AC TO DEVELOP. STILL A LOW RISK FOR AN ISOLD SHOWER...BUT NOT QUITE AS UNSTABLE AS TODAY WITH WEAKER MID LEVEL LAPSE RATES AND TT LESS THAN 50 SO EXPECTING A MAINLY DRY DAY. 850 MB TEMPS 1-2C WHICH IS SIMILAR TO TODAY SO HIGH TEMPS LOW TO MID 60S...UPPER 50S NW HIGHER TERRAIN. NW WINDS IN THE BOUNDARY LAYER APPEAR STRONG ENOUGH TO PRECLUDE SEABREEZES. TUESDAY NIGHT... MID LEVEL TROF MOVES OUT AS SFC HIGH PRES GRADUALLY BUILDS IN FROM THE WEST. EXPECT CLEARING SKIES AND DIMINISHING WIND WHICH WILL RESULT IN A CHILLY NIGHT. MIN TEMPS MOSTLY IN THE 30S AWAY FROM THE COAST WITH SOME SUB-FREEZING READINGS NW MA AND SW NH. TEMPS IN THE LOWER 40S NEAR THE COAST. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... * HIGHLIGHTS... - SLIGHTLY COOL AND DRY WEATHER FOR MIDWEEK - UNSETTLED WEATHER BEGINNING EARLY THURSDAY THROUGH THE WEEKEND OVERVIEW AND MODEL PREFERENCES... 05.12Z MODEL GUIDANCE CONTINUES TO HIGHLIGHT THE SAME SYNOPTIC SCALE AGREEMENT THROUGH THE MID TERM WITH TYPICAL BIASES AND ISSUES RESOLVING THE FINAL SETUP OF A COLD CUTOFF ACROSS THE CENTRAL CANADIAN PRAIRIE. THERE ARE LARGE DISCREPANCIES NOT ONLY IN OPERATIONAL GUIDANCE BUT AVAILABLE ENSEMBLE GUIDANCE AS WELL. HOWEVER...ENSEMBLE MEANS HAVE SHOWN AT LEAST SOME CONSISTENCY AND CONTINUE TO SPLIT DIFFERENCES SEEN WITH INDIVIDUAL MEMBERS AND DETERMINISTIC RUNS. THEREFORE...WILL CONTINUE WITH ENSEMBLES AS A BASELINE FOR THIS FORECAST UPDATE. AS MENTIONED ABOVE THE KEY TO THE FORECAST WILL BE A WEAKENING CUTOFF WHICH IS EXPECTED TO SETTLE ACROSS CENTRAL CANADA...FOLLOWING AN H5 RIDGE WHICH WILL DELIVER MAINLY DRY CONDITIONS INTO WED NIGHT. THERE IS A WIDE SPREAD AS TO WHERE THIS CUTOFF FINALLY SETS UP WHICH WILL NEED TO BE RESOLVED FOR THE FINAL TIMING/STRENGTH OF THE ATTENDANT LOW PRES /WHICH WILL PASS TO THE NW DURING THE WEEKEND/ AND ANY SECONDARY FRONTAL WAVES. THEREFORE...HAVE HIGH CONFIDENCE IN UNSETTLED PATTERN PARTICULARLY FOR THE FRI-WEEKEND...BUT EXACTLY HOW MUCH RAFL AND WHEN IT FALLS REMAINS A BIT OF A QUESTION MARK AT THIS TIME. DETAILS... WED AND THU... DURING THE DAY...HIGH PRES CRESTS ACROSS THE REGION AS H5 RIDGE BEGINS TO SLIDE E OF NEW ENGLAND. THEREFORE...EXPECT DRY WX TO PREVAIL. DESPITE WHAT LOOKS TO BE EASY MIXING TO AROUND H85...TEMPS AT THIS LEVEL WILL STRUGGLE TO BREAK 0C BY PEAK MIXING...SO EXPECT HIGHS ONLY IN THE UPPER 50S TO LOW 60S...COOLER THAN SEASONAL NORMS. BY WED NIGHT AND THU A SFC WARM FRONT IS EXPECTED TO BECOME JAMMED TO THE SW IN WHAT APPEARS TO BE DECENT COLD AIR DAMMING SIGNATURE...THEREFORE ITS OVERRUNNING PROCESSES MAY STRUGGLE TO GENERATE PRECIP MUCH FURTHER N THAN SW CT. HAVE MOST POPS HIGHLIGHTED THERE. THE ONE CAVEAT MAY BE THE REMNANTS OF A WEAKENED MCS WHICH DEVELOPS W OF THE GREAT LAKES...SHOULD ITS MOISTURE/COLD POOL HOLD TOGETHER IT MAY DELIVER SOME RAINFALL FURTHER N THAN CURRENTLY FORECAST. BUT IN ANY CASE A POTENTIALLY SHARP PRECIP GRADIENT IS EXPECTED ACROSS SRN NEW ENGLAND FROM SW TO NE. TEMPS LOOK TO REMAIN NEAR TO COOLER THAN NORMAL THU AS WELL GIVEN THE COLD AIR DAMMING SIGNATURE AND POTENTIAL FOR MARINE INFLUENCED FLOW. THEREFORE...DESPITE MODELS ATTEMPTING TO BRING IN NEAR +4C AIR AT H85 FEEL IT WILL STRUGGLE TO BE WARMER THAN NORMALS...IF IT EVEN MAKES IT THAT FAR. ONE KEY TO WATCH WILL BE FINAL CLOUD COVER AND PRECIP. FRI AND THE WEEKEND... LIKELY THE MOST UNSETTLED PERIOD REGIONWIDE AS THE WARM FRONT FINALLY MAKES A RUN AT MOVING INTO NRN NEW ENGLAND AS THE FIRST IN A SERIES OF SHORTWAVES EJECTS FROM LONGWAVE TROF EXTENDING W OF THE GREAT LAKES. STILL A BIT OF A QUESTION AS TO WHETHER IT ACTUALLY DOES CROSS THE REGION AS SOME ENSEMBLE MEMBERS /AND EVEN THE GFS TO SOME EXTENT/ STILL SHOWS COLD AIR DAMMING SIGNAL IN BOTH MASS AND THETA FIELDS. PWAT VALUES AROUND 1.0-1.25 INCHES /NEARLY TWO STANDARD DEVIATIONS FROM NORMAL/ AND THE SFC LOW PRES AND ATTENDANT COLD FRONT ARE LIKELY TO BE SLOW MOVING THANKS TO BLOCKED FLOW AND SUBTROPICAL RIDGING TO THE E. THEREFORE...WITH THE COMBINATION OF TEMPORAL/SPATIAL UNCERTAINTY WITH ANY WAVES BEGINNING LATE IN THE DAY FRI-SUN...AND THE FACT THAT A SERIES OF FRONTAL WAVES ARE LIKELY TO MOVE ALONG THIS SLOW MOVING FRONT...A PERIOD OF AT LEAST CHANCE POPS IS WARRANTED AND WILL TAKE INTO ACCOUNT BOTH THE UNCERTAINTY AND POTENTIAL FOR A PROLONGED WET EVENT UNTIL BETTER HANDLING OF THE INITIALIZING CUTOFF IS OBSERVED. INSTABILITY ISSUES ARE A LOW CONFIDENCE FORECAST AT THIS TIME AND WILL DEPEND ON WHETHER PORTIONS OF SRN NEW ENGLAND ARE ULTIMATELY ALLOWED IN THE WARM SECTOR. TEMPS ARE THE SAME STORY...BUT THE SUGGESTION OF PRECIP AND CLOUD COVER WILL LEAN ON THE COOLER SIDE OF AVAILABLE GUIDANCE. EARLY NEXT WEEK... ALTHOUGH A BRIEF RIDGING /SUGGESTIVE OF DRY WX/ IS LIKELY TO FOLLOW THE SERIES OF FRONTAL WAVES ENDING AROUND SUNDAY...THE TIMING AND SPATIAL DIFFERENCES TRANSLATE INTO UNCERTAINTY WITH THE TIMING OF ANY DRY WX. HOWEVER...WILL LEAN TOWARD LOW OR NIL POPS AT LEAST FOR MON AND TUE GIVEN AT LEAST SOME CONSISTENCY THAT THE LAST WAVE IS LIKELY TO MOVE E BY SUN NIGHT. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY NIGHT/...HIGH CONFIDENCE. THROUGH 00Z...VFR CIGS 4-6K FT WITH NW GUSTS TO 20 KT. ISOLD SHOWERS EASTERN MA AND RI. TONIGHT THROUGH TUE NIGHT...VFR. BKN CU/AC DEVELOPING DURING TUE THEN CLEARING TUE NIGHT. NW GUSTS AROUND 20 KT DEVELOPING TUE AFTERNOON. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SEABREEZES UNLIKELY THIS AFTERNOON AND TUESDAY. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WED AND WED NIGHT...HIGH CONFIDENCE. VFR. NW FLOW SHIFTS TO THE SW BY LATE DAY/EVENING. SEA BREEZES LIKELY AT NEAR SHORE TERMINALS. THU AND FRI...MODERATE CONFIDENCE. VFR IS LIKELY TO DOMINATE THIS PERIOD. HOWEVER OCCASIONAL MVFR POSSIBLE IN SOME SHOWERS...WITH THE BEST CHANCE MAINLY ACROSS WRN CT AND EXTREME SE MA. WINDS MAINLY S TO SE. OVERNIGHT FOG A POSSIBILITY. SAT...MODERATE CONFIDENCE. BETTER CHANCES FOR MOSTLY MVFR/IFR CONDITIONS IN A MIX OF RAIN AND FOR POTENTIAL FOR THE REST OF SRN NEW ENGLAND TERMINALS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUE NIGHT/...HIGH CONFIDENCE. WINDS AND SEAS BELOW SCA THRESHOLDS THROUGH TUE NIGHT. GENERALLY NW WINDS UNDER 20 KT. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WED INTO FRI...HIGH CONFIDENCE. A PERIOD OF MAINLY QUIET BOATING WEATHER IS EXPECTED WITH WINDS AND SEAS BELOW SMALL CRAFT ADVISORY THRESHOLDS. WINDS SHIFT FROM THE NW TO THE SW BY WED EVENING...THEN REMAIN OUT OF THE S TO SE FOR THU INTO FRI. SOME SHOWERS POSSIBLE...ESPECIALLY ACROSS THE SRN WATERS ON THU AND FRI ALONG WITH THE LOW PROBABILITY OF SOME FOG LEADING TO VSBY REDUCTIONS. SAT...MODERATE CONFIDENCE. INCREASING THREAT FOR RAIN/FOG THROUGH THIS PERIOD. A COMBINATION OF INCREASING SLY WINDS WITH GUSTS TO AROUND 20 KT MAY COMBINE WITH A GRADUALLY BUILDING S SWELL AROUND 5-6 FT BY LATE DAY...LEADING TO THE POTENTIAL FOR SMALL CRAFT ADVISORY CONDITIONS. && .FIRE WEATHER... ELEVATED FIRE WEATHER POTENTIAL FOR TUE AS MIN RH VALUES DECREASE TO 25-30 PERCENT AWAY FROM THE COAST WITH NW WIND GUSTS TO 20-25 MPH. HOWEVER...THE UNDERLYING FUEL BED IS STILL DAMP PER STATE OFFICIALS. NOTE THAT THE DRY CONDITIONS ARE LIKELY TO LINGER ON WED AS WELL...BUT WITH WEAKER WINDS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...KJC/DOODY NEAR TERM...KJC SHORT TERM...KJC LONG TERM...DOODY AVIATION...KJC/DOODY MARINE...KJC/DOODY FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
242 PM EDT MON MAY 5 2014 .SYNOPSIS... HIGH PRESSURE NORTH OF THE GREAT LAKES SLOWLY BUILDS INTO NEW ENGLAND THROUGH WED...PROVIDING DRY AND SEASONABLE WEATHER WITH MILD DAYS AND COOL NIGHTS. THEN A PERIOD OF UNSETTLED WET WEATHER IS EXPECTED FOR THE END OF THE WEEK INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... THROUGH 00Z...COLD POOL ALOFT PRODUCING MARGINAL INSTABILITY WITH ISOLD SHOWERS MOVING S ACROSS SE COASTAL MA AND E MA COASTAL WATER. STEEP MID LEVEL LAPSE RATES 7.0- 7.5 C/KM ACROSS E MA AND SBCAPES NEAR 250 J/KG. HRRR KEEPS THREAT OF ISOLD SHOWERS ACROSS EASTERN MA AND POSSIBLY INTO RI THROUGH THE AFTERNOON AND HAVE MAINTAINED SLIGHT CHC POPS. MAYBE AN ISOLD TSTM. CLEARING TREND TOWARD EVENING. TONIGHT...CLEARING SKIES EXPECTED THIS EVENING...BUT MODELS SHOW INCREASING MID LEVEL MOISTURE MOVING IN OVERNIGHT AHEAD OF NEXT SHORTWAVE. DIMINISHING WINDS THIS EVENING WILL PROVIDE A WINDOW FOR RADIATIONAL COOLING. USED A BLEND OF MOS AND BIAS CORRECTED GRIDS FOR MIN TEMPS...GENERALLY MID 30S TO LOWER 40S. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... TUESDAY... LOOKS LIKE A SIMILAR DAY TO TODAY AS MID LEVEL SHORTWAVE MOVES THROUGH WITH 500 MB TEMPS COOLING TO -25C. ENOUGH MOISTURE IN THE COLUMN FOR ABUNDANT CU/AC TO DEVELOP. STILL A LOW RISK FOR AN ISOLD SHOWER...BUT NOT QUITE AS UNSTABLE AS TODAY WITH WEAKER MID LEVEL LAPSE RATES AND TT LESS THAN 50 SO EXPECTING A MAINLY DRY DAY. 850 MB TEMPS 1-2C WHICH IS SIMILAR TO TODAY SO HIGH TEMPS LOW TO MID 60S...UPPER 50S NW HIGHER TERRAIN. NW WINDS IN THE BOUNDARY LAYER APPEAR STRONG ENOUGH TO PRECLUDE SEABREEZES. TUESDAY NIGHT... MID LEVEL TROF MOVES OUT AS SFC HIGH PRES GRADUALLY BUILDS IN FROM THE WEST. EXPECT CLEARING SKIES AND DIMINISHING WIND WHICH WILL RESULT IN A CHILLY NIGHT. MIN TEMPS MOSTLY IN THE 30S AWAY FROM THE COAST WITH SOME SUB-FREEZING READINGS NW MA AND SW NH. TEMPS IN THE LOWER 40S NEAR THE COAST. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... */ HIGHLIGHTS... - SLIGHTLY COOL AND DRY WEATHER FOR MIDWEEK - UNSETTLED WEATHER BEGINNING EARLY THURSDAY THROUGH THE WEEKEND */ OVERVIEW AND MODEL PREFERENCE... A CONSENSUS BLEND IS PREFERRED THROUGH FRIDAY WEIGHTING TOWARDS THE WARM-FRONT BEING HELD FURTHER SW AGAINST COLD-AIR-DAMMING TO THE NE. ASSOCIATED HIGH PRES STRENGTHENS IN RESPONSE TO WARM-AIR-ADVECTION AHEAD OF THE LOW CENTER DEEPENING LEEWARD OF THE ROCKIES BY MIDWEEK AND LIFTING NE TOWARDS THE HUDSON BAY REGION TOWARDS THE WEEKEND. BUT CONTINUED SPREAD WITH THE WEEKEND FORECAST. PER THE GEFS THERE IS HIGH CONFIDENCE OF UNSETTLED WEATHER BUT SENSIBLE-WEATHER DETAILS REMAIN HIGHLY VARIABLE...ESPECIALLY WITH RESPECT TO PRECIPITATION AMOUNTS. ENSEMBLE MEANS ARE PREFERRED THOUGH DIFFER WITH REGARDS TO PRECIPITATION-AMOUNTS AND SPEED OF INDIVIDUAL WAVES COMPARED TO DETERMINISTIC SOLUTIONS. */ DAY-TO-DAY DETAILS... TUESDAY NIGHT THROUGH WEDNESDAY... A DRY FORECAST. SOME CONCERN OVER ELEVATED FIRE WEATHER POTENTIAL DUE TO THE LACK OF APPRECIABLE RAIN AND MINIMUM RELATIVE HUMIDITIES AROUND 30 PERCENT. THOUGH UNDER THE INFLUENCE OF HIGH PRESSURE... WINDS WILL BE BELOW RED-FLAG WARNING CRITERIA /25 MPH/ AND WE ARE IN THE PRE-GREEN-UP STAGES. NO NEED FOR FIRE WEATHER HEADLINES. CONDITIONS SLIGHTLY-BELOW SEASONABLE-LEVELS WITH HIGHS AROUND THE LOW-60S WITH LOWS AROUND THE LOW-40S WITH H85 TEMPERATURES RANGING AROUND +2C. WILL SEE INCREASING CLOUDS LATE AHEAD OF AN APPROACHING WARM-FRONT. MOSTLY CLEAR OTHERWISE. LIGHT NW-FLOW VEERING SOUTHERLY AS HIGH PRESSURE SHIFTS OFFSHORE. WEDNESDAY NIGHT THROUGH FRIDAY... WARM-FRONT LIFTS TOWARDS THE NE-CONUS IN RESPONSE TO AN INTENSIFYING AREA OF LOW-PRESSURE IN THE LEE OF THE ROCKIES. THE COMBINATION OF BROAD-SCALE ISENTROPIC LIFT AS WELL AS FORCED ASCENT PER MID-LEVEL DISTURBANCES ALONG THE WARM-FRONT WILL YIELD LIGHT RAIN CHANCES THE BETTER OF WHICH WILL BE ACROSS SW NEW ENGLAND AS COLD-AIR-DAMMING TO THE N/E INCREASES IN RESPONSE TO UPPER-LEVEL RIDGING E OF THE DEEP- TROUGHING BUILDING OUT OF THE W-CONUS. STILL SOME UNCERTAINTY AS CONVEYED BY THE PREVIOUS FORECASTER AS TO THE STRENGTH AND INFLUENCE OF POTENTIAL COLD-AIR-DAMMING. WILL GO WITH CHANCE POPS AND MOSTLY CLOUDY CONDITIONS WITH OVER-RUNNING. DO NOT BELIEVE THUNDERSTORMS WILL BE AN ISSUE WITH THE PROXIMITY OF A COOLER AND MORE STABLE AIRMASS. FRIDAY NIGHT THROUGH THE WEEKEND... CONTINUED VARIANCE AMONG MODEL-FORECAST SOLUTIONS IN HANDLING N- AND S-STREAM DISTURBANCES ALONG A COLD FRONT ATTENDANT TO A STRONG LOW LIFTING OUT OF THE GREAT PLAINS INTO THE HUDSON BAY REGION. HIGH CONFIDENCE OF UNSETTLED WEATHER AS THE GEFS EXHIBITS SIGNALS OF A DECENT PWAT AXIS THE MEAN VALUES OF WHICH EXCEED 1-INCH COLLOCATED WITH ANOMALOUS S/SW MOISTURE TRANSPORT +2 SD /SLIGHTLY GREATER IN AREAL EXTENT THAN YESTERDAYS 04.0Z GEFS/. BUT LOW CONFIDENCE WITH REGARDS TO EXACT SPECIFICS. SIGNIFICANT SPREAD IN PRECIPITATION OUTCOMES...WILL CONTINUE WITH HIGH-CHANCE POPS. THOUGH GEFS MEAN H85 TEMPS +10-12C SUGGEST WARMER-THAN-AVERAGE CONDITIONS...AGREE WITH THE PREVIOUS FORECASTER THAT THE ABUNDANCE OF WET WEATHER AND CLOUDS YIELD COOLER-THAN-AVERAGE CONDITIONS. SO THERE IS RANGE OF POSSIBILITIES WITH REGARDS TO TEMPERATURES...EVEN THE PLAUSIBILITY OF A WARM-SECTOR SCENARIO FOR SATURDAY. SHALL PREVAIL WITH CONDITIONS CLOSE TO SEASONABLE-NORMS. EARLY NEXT WEEK... 8-DAY CONSENSUS FORECAST PER THE CANADIAN STILL SUGGESTS A STRONG NEGATIVE ANOMALY OVER THE GREAT LAKES REGION. WHILE A PERIOD OF DRY WEATHER WILL FOLLOW THE WET WEATHER OVER THE WEEKEND...DISTURBED WEATHER MAY MAKE A RETURN. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY NIGHT/...HIGH CONFIDENCE. THROUGH 00Z...VFR CIGS 4-6K FT WITH NW GUSTS TO 20 KT. ISOLD SHOWERS EASTERN MA AND RI. TONIGHT THROUGH TUE NIGHT...VFR. BKN CU/AC DEVELOPING DURING TUE THEN CLEARING TUE NIGHT. NW GUSTS AROUND 20 KT DEVELOPING TUE AFTERNOON. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SEABREEZES UNLIKELY THIS AFTERNOON AND TUESDAY. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...WEDNESDAY THROUGH FRIDAY... WEDNESDAY...HIGH CONFIDENCE. VFR. NW-FLOW DIMINISHING TURNING SW. SEA-BREEZE POSSIBLE ALONG THE SHORES WEDNESDAY MIDDAY INTO AFTERNOON. WEDNESDAY NIGHT INTO FRIDAY NIGHT...MODERATE CONFIDENCE. CONDITIONS DETERIORATING LATE WITH LOW-END VFR TO MVFR CIGS. -SHRA ACROSS SW NEW ENGLAND INITIALLY... INCREASING AREAL COVERAGE NE. WINDS SHIFTING S AND INCREASING AHEAD OF AN APPROACHING COLD-FRONT. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUE NIGHT/...HIGH CONFIDENCE. WINDS AND SEAS BELOW SCA THRESHOLDS THROUGH TUE NIGHT. GENERALLY NW WINDS UNDER 20 KT. OUTLOOK...WEDNESDAY THROUGH FRIDAY... WEDNESDAY...HIGH CONFIDENCE. NW-WINDS DIMINISHING TURNING W. SEA-BREEZE ALONG THE SHORES WEDNESDAY MIDDAY INTO AFTERNOON. WAVES BELOW 5 FEET. GOOD BOATING WEATHER. WEDNESDAY NIGHT INTO FRIDAY NIGHT...MODERATE CONFIDENCE. WINDS TURNING SOUTHERLY. INCREASING AREAL COVERAGE OF RAIN SHOWERS INITIALLY OVER THE SW INTO FRIDAY...INCREASING NE TOWARDS SATURDAY MORNING. SEAS WILL GRADUALLY BUILD BUT REMAIN BELOW 5 FEET. NO VISIBILITY IMPACTS. && .FIRE WEATHER... ELEVATED FIRE WEATHER POTENTIAL FOR TUE AS MIN RH VALUES DECREASE TO 25-30 PERCENT AWAY FROM THE COAST WITH NW WIND GUSTS TO 20-25 MPH. HOWEVER...THE UNDERLYING FUEL BED IS STILL DAMP PER STATE OFFICIALS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...KJC NEAR TERM...KJC SHORT TERM...KJC LONG TERM...SIPPRELL AVIATION...KJC/SIPPRELL MARINE...KJC/SIPPRELL FIRE WEATHER...KJC
AREA FORECAST DISCUSSION
NWS TAUNTON MA
712 AM EDT MON MAY 5 2014 .SYNOPSIS... HIGH PRESSURE JUST NORTH OF THE GREAT LAKES SLOWLY BUILDS INTO NEW ENGLAND THROUGH WED...PROVIDING DRY AND SEASONABLE WEATHER WITH MILD DAYS AND COOL NIGHTS. THEN UNSETTLED WET WEATHER IS EXPECTED FOR THE END OF THE WEEK INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 730 AM UPDATE... MINOR CHANGES TO THE FORECAST. NOTING THE HRRR...HAVE INCREASED THE POSSIBILITY OF PRECIPITATION ACROSS EASTERN AND SOUTHEASTERN NEW ENGLAND FOR THE MIDDAY INTO AFTERNOON HOURS. THE MAJORITY OF FORECAST GUIDANCE HAS OUTCOMES COMPLETELY DRY WHEREAS THE HRRR IS THE LONE-OUTLIER. THUS HAVE GONE WITH A ROUGHLY 20-PERCENT CHANCE. REMAINDER OF THE FORECAST CONTINUES HIGHLIGHTED IN THE DISCUSSION BELOW. PREVIOUS DISCUSSION... ANOMALOUS CLOSED LOW /-2 STD FROM CLIMO/ OVER NOVA SCOTIA EARLY THIS MORNING SLOWLY MOVES SEAWARD TODAY. HOWEVER WEAK CYCLONIC FLOW CONTINUES OVER SOUTHERN NEW ENGLAND ALONG WITH COLD POOL ALOFT /-26C AT H5/. THIS YIELDS STEEP MID LEVEL LAPSE RATES ON THE ORDER OF 7.5C/KM...WHICH WILL BE SUFFICIENT FOR ABUNDANT DIURNAL CU TO DEVELOP. BUFKIT RH PROFILES SUGGEST MOISTURE WILL BE RATHER SHALLOW ALONG WITH HIGH CLOUD BASES...AROUND 5-6KFT. THUS ONLY EXPECTING A SPOT SHOWER/SPRINKLE OR PERHAPS JUST SOME VIRGA THIS AFTERNOON. HENCE MOST OF THE REGION WILL REMAIN DRY. GREATEST RISK FOR A SHOWER /ALBEIT VERY LOW/ WILL BE ACROSS SOUTHEAST MA WHERE LOCAL SEABREEZES MAY ENHANCE LOW LEVEL CONVERGENCE. OTHERWISE STRONG MAY SUNSHINE WILL GO TO WORK AND WARM AIRMASS INTO THE LOW AND MID 60S...WITH UPPER 50S ACROSS THE HIGHER TERRAIN. MORE CLOUDS OVER EASTERN MA AND RI WITH MORE SUNSHINE ACROSS CT AND WESTERN-CENTRAL MA. GUSTY NW WINDS THIS MORNING WILL EASE A BIT THIS AFTERNOON AS PGRAD RELAXES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... TONIGHT... DIURNAL CLOUDS QUICKLY ERODES WITH SUNSET. WINDS DIMINISH AS WELL YIELDING A COOL NIGHT WITH LOW TEMPS IN THE U30S TO M40S. TUESDAY... MORE OF THE SAME WITH MEAN MID LEVEL TROUGH AXIS JUST EAST OF NEW ENGLAND. THIS RESULTS IN CYCLONIC FLOW AND COLD POOL ALOFT LINGERING ACROSS EASTERN NEW ENGLAND FOR ONE MORE DAY. AS A RESULT EXPECT ANOTHER ROUND OF DIURNAL CLOUDS AND JUST THE SLIGHT CHANCE OF A BRIEF SPOT SHOWER OVER EASTERN MA GIVEN PROXIMITY TO CYCLONIC FLOW AND COLD POOL ALOFT. OTHERWISE A DRY DAY WITH COOL MORNING TEMPS REBOUNDING WELL INTO THE 60S AGAIN. WEAKENING PGRAD SUGGEST LIGHT WINDS WITH POSSIBLE AFTERNOON SEABREEZES. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... */ HIGHLIGHTS... - SLIGHTLY COOL AND DRY WEATHER FOR MIDWEEK - UNSETTLED WEATHER BEGINNING EARLY THURSDAY THROUGH THE WEEKEND */ OVERVIEW AND MODEL PREFERENCE... A CONSENSUS BLEND IS PREFERRED THROUGH FRIDAY WEIGHTING TOWARDS THE WARM-FRONT BEING HELD FURTHER SW AGAINST COLD-AIR-DAMMING TO THE NE. ASSOCIATED HIGH PRES STRENGTHENS IN RESPONSE TO WARM-AIR-ADVECTION AHEAD OF THE LOW CENTER DEEPENING LEEWARD OF THE ROCKIES BY MIDWEEK AND LIFTING NE TOWARDS THE HUDSON BAY REGION TOWARDS THE WEEKEND. BUT CONTINUED SPREAD WITH THE WEEKEND FORECAST. PER THE GEFS THERE IS HIGH CONFIDENCE OF UNSETTLED WEATHER BUT SENSIBLE-WEATHER DETAILS REMAIN HIGHLY VARIABLE...ESPECIALLY WITH RESPECT TO PRECIPITATION AMOUNTS. ENSEMBLE MEANS ARE PREFERRED THOUGH DIFFER WITH REGARDS TO PRECIPITATION-AMOUNTS AND SPEED OF INDIVIDUAL WAVES COMPARED TO DETERMINISTIC SOLUTIONS. */ DAY-TO-DAY DETAILS... TUESDAY NIGHT THROUGH WEDNESDAY... A DRY FORECAST. SOME CONCERN OVER ELEVATED FIRE WEATHER POTENTIAL DUE TO THE LACK OF APPRECIABLE RAIN AND MINIMUM RELATIVE HUMIDITIES AROUND 30 PERCENT. THOUGH UNDER THE INFLUENCE OF HIGH PRESSURE... WINDS WILL BE BELOW RED-FLAG WARNING CRITERIA /25 MPH/ AND WE ARE IN THE PRE-GREEN-UP STAGES. NO NEED FOR FIRE WEATHER HEADLINES. CONDITIONS SLIGHTLY-BELOW SEASONABLE-LEVELS WITH HIGHS AROUND THE LOW-60S WITH LOWS AROUND THE LOW-40S WITH H85 TEMPERATURES RANGING AROUND +2C. WILL SEE INCREASING CLOUDS LATE AHEAD OF AN APPROACHING WARM-FRONT. MOSTLY CLEAR OTHERWISE. LIGHT NW-FLOW VEERING SOUTHERLY AS HIGH PRESSURE SHIFTS OFFSHORE. WEDNESDAY NIGHT THROUGH FRIDAY... WARM-FRONT LIFTS TOWARDS THE NE-CONUS IN RESPONSE TO AN INTENSIFYING AREA OF LOW-PRESSURE IN THE LEE OF THE ROCKIES. THE COMBINATION OF BROAD-SCALE ISENTROPIC LIFT AS WELL AS FORCED ASCENT PER MID-LEVEL DISTURBANCES ALONG THE WARM-FRONT WILL YIELD LIGHT RAIN CHANCES THE BETTER OF WHICH WILL BE ACROSS SW NEW ENGLAND AS COLD-AIR-DAMMING TO THE N/E INCREASES IN RESPONSE TO UPPER-LEVEL RIDGING E OF THE DEEP- TROUGHING BUILDING OUT OF THE W-CONUS. STILL SOME UNCERTAINTY AS CONVEYED BY THE PREVIOUS FORECASTER AS TO THE STRENGTH AND INFLUENCE OF POTENTIAL COLD-AIR-DAMMING. WILL GO WITH CHANCE POPS AND MOSTLY CLOUDY CONDITIONS WITH OVER-RUNNING. DO NOT BELIEVE THUNDERSTORMS WILL BE AN ISSUE WITH THE PROXIMITY OF A COOLER AND MORE STABLE AIRMASS. FRIDAY NIGHT THROUGH THE WEEKEND... CONTINUED VARIANCE AMONG MODEL-FORECAST SOLUTIONS IN HANDLING N- AND S-STREAM DISTURBANCES ALONG A COLD FRONT ATTENDANT TO A STRONG LOW LIFTING OUT OF THE GREAT PLAINS INTO THE HUDSON BAY REGION. HIGH CONFIDENCE OF UNSETTLED WEATHER AS THE GEFS EXHIBITS SIGNALS OF A DECENT PWAT AXIS THE MEAN VALUES OF WHICH EXCEED 1-INCH COLLOCATED WITH ANOMALOUS S/SW MOISTURE TRANSPORT +2 SD /SLIGHLY GREATER IN AREAL EXTENT THAN YESTERDAYS 04.0Z GEFS/. BUT LOW CONFIDENCE WITH REGARDS TO EXACT SPECIFICS. SIGNIFICANT SPREAD IN PRECIPITATION OUTCOMES...WILL CONTINUE WITH HIGH-CHANCE POPS. THOUGH GEFS MEAN H85 TEMPS +10-12C SUGGEST WARMER-THAN-AVERAGE CONDITIONS...AGREE WITH THE PREVIOUS FORECASTER THAT THE ABUNDANCE OF WET WEATHER AND CLOUDS YIELD COOLER-THAN-AVERAGE CONDITIONS. SO THERE IS RANGE OF POSSIBILITIES WITH REGARDS TO TEMPERATURES...EVEN THE PLAUSIBILITY OF A WARM-SECTOR SCENARIO FOR SATURDAY. SHALL PREVAIL WITH CONDITIONS CLOSE TO SEASONABLE-NORMS. EARLY NEXT WEEK... 8-DAY CONSENSUS FORECAST PER THE CANADIAN STILL SUGGESTS A STRONG NEGATIVE ANOMALY OVER THE GREAT LAKES REGION. WHILE A PERIOD OF DRY WEATHER WILL FOLLOW THE WET WEATHER OVER THE WEEKEND...DISTURBED WEATHER MAY MAKE A RETURN. && .AVIATION /11Z MONDAY THROUGH FRIDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH MONDAY NIGHT/...HIGH CONFIDENCE. VFR. BREEZY NW WINDS WITH GUSTS UP TO AROUND 20 KTS DIMINISHING INTO THE EVENING. MIDDAY-AFTERNOON SHOWERS ARE POSSIBLE OVER E/SE NEW ENGLAND. SCT-BKN 4-5 KFT CIGS. WILL NEED TO MONITOR FOR A POTENTIAL SEA-BREEZE ACROSS SE MA. ACTIVITY DIMINISHES OVERNIGHT. VFR INTO TUESDAY WITH LESSER WNW WINDS AND GREATER POSSIBILITY OF SEA-BREEZES. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... TUESDAY NIGHT THROUGH WEDNESDAY...HIGH CONFIDENCE. VFR. NW-FLOW DIMINISHING TURNING SW. SEA-BREEZE POSSIBLE ALONG THE SHORES WEDNESDAY MIDDAY INTO AFTERNOON. WEDNESDAY NIGHT INTO FRIDAY NIGHT...MODERATE CONFIDENCE. CONDITIONS DETERIORATING LATE WITH LOW-END VFR TO MVFR CIGS. -SHRA ACROSS SW NEW ENGLAND INITIALLY... INCREASING AREAL COVERAGE NE. WINDS SHIFTING S AND INCREASING AHEAD OF AN APPROACHING COLD-FRONT. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUE/...HIGH CONFIDENCE. NW WINDS 15 TO 20 KT WITH GUSTS TO 25 THIS MORNING WILL BEGIN TO EASE TOWARD MIDDAY WITH LOCAL SEABREEZES POSSIBLE OVER SOUTHEAST MA. OTHER THAN A BRIEF SPOT AFTERNOON SHOWER NEAR SHORE EXPECTING DRY WEATHER AND GOOD VSBY THRU TUE. WNW WINDS 15-20 KT EXPECTED TONIGHT AND TUE. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... TUESDAY NIGHT THROUGH WEDNESDAY...HIGH CONFIDENCE. NW-WINDS DIMINISHING TURNING W. SEA-BREEZE ALONG THE SHORES WEDNESDAY MIDDAY INTO AFTERNOON. WAVES BELOW 5 FEET. GOOD BOATING WEATHER. WEDNESDAY NIGHT INTO FRIDAY NIGHT...MODERATE CONFIDENCE. WINDS TURNING SOUTHERLY. INCREASING AREAL COVERAGE OF RAIN SHOWERS INITIALLY OVER THE SW INTO FRIDAY...INCREASING NE TOWARDS SATURDAY MORNING. SEAS WILL GRADUALLY BUILD BUT REMAIN BELOW 5 FEET. NO VISIBILITY IMPACTS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ230>237-250- 251-254>256. && $$ SYNOPSIS...NOCERA/SIPPRELL NEAR TERM...NOCERA/SIPPRELL SHORT TERM...NOCERA LONG TERM...SIPPRELL AVIATION...NOCERA/SIPPRELL MARINE...NOCERA/SIPPRELL
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
136 AM EDT MON MAY 5 2014 .SYNOPSIS... HIGH PRESSURE WILL PREVAIL THIS WEEK. A COLD FRONT COULD APPROACH THE REGION NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... HIGH PRESSURE WILL EXTEND ACROSS THE AREA OVERNIGHT. A BACKDOOR COLD FRONT WILL APPROACH FROM THE NORTH EARLY MONDAY...BUT IS EXPECTED TO REMAIN NORTH OF THE SOUTH SANTEE RIVER. CLEAR SKIES OVERNIGHT WITH FORECAST OVERNIGHT LOWS NEAR 60 INLAND AND MID 60S CLOSE TO THE COAST. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/... ONGOING FORECASTS FOR MONDAY THROUGH WEDNESDAY REMAIN ON TRACK... WITH ONLY MINOR ADJUSTMENTS WITHIN THE SUNDAY AFTERNOON PACKAGE. DEEP LAYER HIGH PRESSURE CENTERED S/SW OF THE REGION WILL MAINTAIN A SYNOPTIC DOWNSLOPE/OFFSHORE FLOW...PINNING THE AFTERNOON SEA BREEZE CLOSE TO THE COAST MONDAY AND TUESDAY. HIGH TEMPS IN THE LOWER 90S WILL BE COMMON...AND HIGHS WELL INTO THE 80S WILL LIKELY PUSH TO THE BEACHES BEFORE THE SEA BREEZE DEVELOPS. A COLD FRONT WILL STALL OVER N/NE SC WEDNESDAY...AND THE CENTER OF SURFACE HIGH PRESSURE WILL SHIFT OFFSHORE. THUS...THE SEA BREEZE WILL DEVELOP EARLIER AND WILL PUSH INLAND. THE MARINE INFLUENCE WILL LIMIT HIGH TEMPERATURES ON AREA BEACHES TO THE 70S AND SHOULD TRANSLATE INTO SLIGHTLY LOWER INLAND TEMPERATURES AS COMPARED WITH HIGHS EXPECTED MONDAY-TUESDAY. HOWEVER...GIVEN THE BUILDING UPPER RIDGE OVER THE REGION...HIGHS CLOSE TO 90F WILL STILL PREVAIL AWAY FROM THE COAST. LOW TEMPERATURES IN THE LOWER TO MIDDLE 60S INLAND AND AROUND 70F ON THE BEACHES WILL BE COMMON. NO PRECIPITATION IS EXPECTED AND POPS REMAIN VIRTUALLY ZERO THROUGH THE PERIOD. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... DRY AND UNSEASONABLY WARM WEATHER WILL PERSIST THROUGH FRIDAY AS THE DEEP LAYERED RIDGE REMAINS IN PLACE. A DE-AMPLIFYING UPPER TROUGH WILL SHIFT INTO THE EASTERN UNITED STATES NEXT WEEKEND...PUSHING A A COLD FRONT TOWARD THE REGION FROM THE WEST. PROGRESS OF THE FRONT IS UNCERTAIN AND COULD BE SLOWED IF DEEP LAYER RIDGING PERSISTS ALONG THE SOUTHEAST COAST. EVEN SO...MOISTURE SHOULD INCREASE SUFFICIENTLY TO MAINTAIN ONGOING SLIGHT CHANCE POPS SATURDAY NIGHT AND SUNDAY. WEEKEND HIGH TEMPS WILL COOL SLIGHTLY INTO THE LOWER TO MIDDLE 80S. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... VFR. EXTENDED AVIATION OUTLOOK...VFR. && .MARINE... TONIGHT...LOWERED OVERNIGHT. WIND SPEEDS SLIGHTLY BASED ON 18Z MODEL AND SHORT TERM RAP MODEL DATA. EXPECT PEAK WINDS OF 10-15 KT...EXCEPT 15 KT CHARLESTON COUNTY WATERS AND PARTS OF THE GEORGIA OFFSHORE WATERS. SEAS 2-3 FT. MONDAY THROUGH TUESDAY...HIGH PRESSURE WILL BE CENTERED S/SW OF THE WATERS. AS A RESULT...DEEP LAYER OFFSHORE FLOW WILL DOMINATE MONDAY AND TUESDAY...AND THE SEA BREEZE CIRCULATION WILL CAUSE WINDS TO BACK TOWARD THE SW BOTH AFTERNOON. ALSO...04/12Z GUIDANCE SUGGEST THAT A MODEST NOCTURNAL SURGE OF SW WINDS WILL OCCUR EACH NIGHT...PERHAPS ACCOMPANIED BY OCCASIONAL GUSTS AS HIGH AS 20 KT ESPECIALLY MONDAY NIGHT. HOWEVER...WINDS WILL REMAIN BELOW SMALL CRAFT ADVISORY STRENGTH THROUGH THE FORECAST PERIOD. HIGH PRESSURE WILL SHIFT INTO THE WESTERN ATLANTIC MID TO LATE WEEK. AS A RESULT...SYNOPTIC SOUTHERLY FLOW WILL DEVELOP AND WILL SUPPORT AN ACTIVE SEA BREEZE CIRCULATION EACH MIDDAY THROUGH EARLY EVENING MID TO LATE WEEK. SEAS THROUGH THE PERIOD WILL RANGE FROM 1-3 FT WITHIN NEARSHORE WATERS TO AS HIGH AS 3-4 FT BEYOND 20 NM. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE...
AREA FORECAST DISCUSSION
NWS POCATELLO ID
924 AM MDT MON MAY 5 2014 .UPDATE...UPPER LOW CONTINUES TO DEEPEN OFF PACIFIC COAST. MOISTURE STREAMING INTO GREAT BASIN AHEAD OF STRONG SHORTWAVE ALONG CALIFORNIA COAST. RADAR SHOWING BAND OF WEAK RETURNS OVER SOUTHERN HIGHLANDS THIS MORNING. AREA WEB CAMS SHOWING VIRGA ACROSS THE REGION. WITH STRONG UPSTREAM MOISTURE EXPECT LOWER LEVELS TO CONTINUE TO MOISTEN THROUGH THE DAY. LATEST HRRR SHOWING CONVECTION BUBBLING ACROSS SOUTHERN PORTIONS OF FORECAST AREA. HAVE ADDED ISOLATED SHOWERS THIS MORNING TO HIGHER ELEVATIONS SOUTHERN HIGHLANDS AND INCREASED POPS SLIGHTLY THROUGH THE AFTERNOON. WINDS GUSTY EARLY THIS MORNING AND COULD BE BORDERLINE FOR LAKE WIND ADVISORY. STRONGEST GRADIENT IN LOWER SNAKE PLAIN OCCURS THIS MORNING AND GUIDANCE SUPPORTS WEAKENING OF WINDS LATER TODAY. WILL HOLD OFF ON LAKE HEADLINE FOR THIS MORNING. DMH && .PREV DISCUSSION... /ISSUED 254 AM MDT MON MAY 5 2014/ SHORT TERM...LOW PRESSURE TROUGH NEAR THE PACIFIC NORTHWEST COAST THIS MORNING PROJECTED BY MODELS TO MOVE OVER NEVADA BY TUESDAY MORNING. INCREASING SOUTHWEST FLOW ON THE LEADING EDGE OF THE TROUGH AND A DEVELOPING WAVE SHOULD FOCUS SCATTERED TO NUMEROUS SHOWERS IN THE CENTRAL MOUNTAINS LATER THIS AFTERNOON. NAM12 MODEL FAVORS A COUPLE OF SURFACE WAVES DEVELOPING LATE THIS AFTERNOON OR EARLY EVENING...ONE IN NEVADA AND ANOTHER IN THE UPPER SNAKE PLAIN. NEGATIVE SURFACE LIS AND STEEP TEMPERATURE LAPSE RATES IN THE SOUTH CENTRAL MOUNTAINS...AND TO A LESSER EXTENT IN THE LOST RIVER AND PAHSIMEROI AREA. ISOLATED THUNDERSTORMS WILL BE POSSIBLE IN BOTH AREAS. INCREASING CLOUD COVER SHOULD HELP LIMIT WIND SPEEDS ON AMERICAN FALLS TO SW AT 15 TO 20 MPH THIS AFTERNOON...THEREFORE NO ADVISORY WAS ISSUED FOR THE RESERVOIR. A 700 MB LOW DEVELOPING IN NE NEVADA NEAR MIDNIGHT TONIGHT DRIFTS EASTWARD TO ABOUT WHERE INTERSTATE 84 CROSSES THE IDAHO AND UTAH STATE LINE. THE FLOW WRAPPING AROUND THE LOW SHOULD FOCUS PRECIPITATION OVER CASSIA COUNTY DURING THE DAY TUESDAY. NORTHERLY WINDS ON COOL SIDE OF TROUGH ALSO LOWER SNOW LEVELS TO ABOUT 6200-6500 FEET ELEVATION. MAGIC MOUNTAIN COULD GET 3 TO 5 INCHES OF SNOW...MOSTLY ABOVE 6500 FEET. BOTH THE GFS AND ECMWF MODELS FAVOR VERY SLOW EASTWARD PROGRESSION OF THE UPPER TROUGH ON WEDNESDAY AND MAINTAIN SCATTERED SHOWERS OVER ALL SE IDAHO...WHILE THE NAM IS FASTER TO MOVE PRECIPITATION TO THE EAST. WITH A CLOSED CIRCULATION TO OUR NORTH IN CANADA AND ANOTHER CLOSED CIRCULATION CROSSING NEVADA AND UTAH...PREFERENCE WAS GIVEN TO THE SLOWER TIMING. CLOUDS...SHOWERS AND NORTHERLY SURFACE WINDS TUESDAY AND WEDNESDAY WILL HOLD AFTERNOON HIGHS TO AROUND 60F. NORTH WINDS WEDNESDAY MAY BE STRONG ENOUGH TO WARRANT A LAKE WIND ADVISORY ON AMERICAN FALLS RESERVOIR. A VERY SHORT LIVED BREAK IN THE WEATHER IS EXPECT THURSDAY...MODEL CONSENSUS LEANING TOWARDS ANOTHER DISTURBANCE BY FRIDAY MORNING. RS LONG TERM...THURSDAY NIGHT THROUGH SUNDAY. EAST IDAHO WILL BE MOSTLY DRY UNDER WEAK UPPER LEVEL RIDGE AND NORTHWEST FLOW FOR THURSDAY. A SHALLOW UPPER LEVEL TROUGH EMBEDDED IN NORTHWEST FLOW WILL MOVE THROUGH THE AREA ON FRIDAY AND GENERATE ADDITIONAL SHOWERS AND A FEW THUNDERSTORMS FOR THE AFTERNOON AND EVENING HOURS. UPPER LEVEL FLOW RETURNS TO NORTHWESTERLY FOR SATURDAY WITH THE POTENTIAL FOR SHOWERS ALONG THE MONTANA BORDER AGAIN. FOR SUNDAY...A HIGH DEGREE OF UNCERTAINTY IN THE FORECAST AS THE GFS AND ECMWF SHOWING DISTINCTLY DIFFERING TIMING ON THE NEXT SYSTEM. THE ECMWF INDICATES ANOTHER SYSTEM SWINGING THROUGH THE NORTHERN ROCKIES SUNDAY MORNING WHILE THE GFS DELAYS THE ARRIVAL UNTIL MONDAY MORNING. LOOK FOR MODERATE TO STRONG WINDS FRIDAY AND SATURDAY. TEMPERATURES WILL REMAIN SLIGHTLY BELOW NORMAL THROUGH THE EXTENDED PERIOD. DSH AVIATION...EXPECT VFR CONDITIONS TODAY WITH BREEZY DAYTIME WINDS OF 15 TO 25 MPH. WILL SEE SOME SHOWERS DEVELOP OVER PORTIONS OF THE NORTHERN CENTRAL MOUNTAINS AND OVER THE SOUTHEAST HIGHLANDS THIS AFTERNOON AND EVENING IN THE VICINITY OF PIH AND IDA. DSH HYDROLOGY...ANTICIPATED RAINFALL AND ABOVE NORMAL TEMPERATURES WILL CONTRIBUTE TO INCREASED FLOWS ON LOCAL RIVERS AND STREAMS. CURRENT ESTIMATES SUGGEST THE HENRYS FORK NEAR REXBURG WILL APPROACH BANK FULL BY THURSDAY. RS && .PIH WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1001 PM CDT TUE MAY 6 2014 .DISCUSSION... 909 PM CDT CONVECTION DEVELOPING ACROSS THE FAR NORTH METRO PROMPTED A SPECIAL WEATHER STATEMENT ISSUANCE. THE FORECAST WAS UPDATED TO REFLECT SLIGHTLY HIGHER CHANCES OF THUNDER NORTH OF INTERSTATE 80 THE REST OF TONIGHT...AS WELL AS TO MAKE SOME HOURLY FORECAST TEMPERATURE ADJUSTMENTS. THE SURFACE STATIONARY FRONT REMAINS DRAPED WELL TO OUR SOUTH THIS EVE WITH 00Z RAOBS AND CURRENT PROFILER ANALYSIS INDICATING A 40-45 KT SRLY LOW-LEVEL JET HAVING DEVELOPED NORTH OF THIS INTO IA AND ACROSS NORTHERN IL. THIN ARCS OF TCU WERE NOTED ON LATE DAY VISIBLE SATELLITE AND OBSERVATIONS HAVE INDICATED AN INCREASING LAYER OF 8K-10K FT CIGS. THE 00Z DVN RAOB AND AREA AMDAR SOUNDINGS WERE INDICATING A MOISTENING AROUND THAT 800-750MB LAYER...WHICH WHEN LIFTED FROM THAT LAYER ON THE DVN SOUNDING WOULD PROVIDE OVER 1500 J/KG OF MUCAPE...THOUGH WITH STILL A MINOR CAP. AS A SUBTLE SHORT WAVE NEAR KANSAS CITY PROGRESSES NORTHEAST AND OVERALL MOISTURE TRANSPORT STRENGTHENS...WOULD EXPECT TO SEE THAT SLIGHT CAPPING OVERCOME WITH ISOLATED TO SCATTERED CONVECTION DEVELOPING ACROSS THE EASTERN IA/SOUTHERN WI REGION...AND POSSIBLY NORTHERN IL...ESPECIALLY GIVEN CURRENT STORM WAS ALREADY ABLE TO DEVELOP. IN ADDITION...THE TREND WITH THE HOURLY-RAN HRRR HAS BEEN TO INCREASE COVERAGE OF SHOWERS/STORMS EARLY OVERNIGHT...WHICH GIVEN CURRENT OBSERVATIONAL ANALYSIS MAKES SENSE. HAVE BOOSTED POPS SOME OVER THE NORTHERN TWO TIERS OF COUNTIES BUT REMAIN IN THE CHANCE CATEGORY. GIVEN THE RADAR TRENDS WITH THE MCHENRY/LAKE COUNTY STORM...HAVING SPRUNG TO 40 DBZ OVER 35K FT WITHIN THREE SCANS OF DEVELOPING...COULD STILL SEE AN ELEVATED HAILER OR TWO ACROSS FAR NORTHERN ILLINOIS. THE ENVIRONMENT FOR THESE REMAINS MORE SUPPORTIVE TO THE WEST AND NORTHWEST OF THE LOCAL AREA. THE MARINE LAYER CONTINUED TO RE-INFORCE ITSELF EARLY THIS EVE ACROSS THE NORTH AND CENTRAL PARTS OF THE CHICAGO METRO...WITH SOME MID 40S ALONG THE LAKE SHORE AND LOWER 50S STARTING TO REACH SOME OUTLYING AREAS. DID ADJUST MINS DOWN BUT INDICATED SORT OF A LEVELING OFF TREND TO THIS TEMPERATURE FALL...WITH EVEN POTENTIAL RISING LATE GIVEN INCREASING SURFACE DEW POINTS. LOOKING AHEAD TO WEDNESDAY...STILL SOME POSSIBILITY TO SEE ISOLATED CONVECTION IN THE MORNING AS A WEAK SHORT WAVE PASSES...AND THE 00Z NAM CONTINUES TO SHOW THIS SUBTLE FEATURE. COULD ALSO BE SOME FOG DEVELOPING ACROSS FAR SOUTHERN LAKE MICHIGAN DURING THE MORNING AS THE WARM FRONT AND HIGH DEW POINTS BUTT UP AGAINST THE COOL LAKE. WITH THE WARM FRONT LIKELY TO PROGRESS SLOWER OVER THE MARINE LAYER...IT COULD INDUCE THE FOG. HAVE NOT ADDED INTO THE FORECAST AT THIS TIME BUT SOMETHING WE WILL WATCH AS THAT WOULD POSSIBLY MOVE INTO LAKE ADJACENT AREAS OF THE CHICAGO METRO. MTF //PREV DISCUSSION... 329 PM CDT SHORT TERM...TONIGHT THROUGH FRIDAY... PRIMARY FORECAST CONCERNS ARE WITH HOW WARM TEMPERATURES GET TOMORROW AND THURSDAY AND ON THUNDERSTORM POTENTIAL. W/V IMAGERY SHOWS THE ONGOING AMPLIFICATION OF UPPER RIDGING OVER THE MIDWEST INDUCED BY A DEEP TROUGH/CLOSED LOW OVER THE SOUTHWEST US. AT THE SURFACE...LOW PRESSURE IS DEVELOPING OVER THE SOUTHERN HIGH PLAINS WITH THE VERY STRONG WARM FRONT THAT HAS BEEN IN PLACE OVER THE REGION THE PAST FEW DAYS STRETCHING ACROSS DOWNSTATE IL AND IN. STRONG WAA ALOFT NORTH OF THE BOUNDARY HAS ALLOWED FOR TEMPERATURES TO WARM ABOVE 70 SOUTH OF I-80...WHILE ONSHORE FLOW HAS RESULTED IN ANOTHER COOL DAY FOR LAKESHORE AREAS. TONIGHT... AS THE SFC WARM FRONT INCHES NORTH...A STRONG LOW LEVEL JET WILL DEVELOP WITH GOOD MOISTURE TRANSPORT AND CONVERGENCE FOCUSED ON THE NOSE OF THE LLJ INTO NORTHEAST IA AND FAR SOUTHERN WI. GUIDANCE ALSO HINTS AT A MIDLEVEL SHORTWAVE RIDING IN ON SOUTHWEST FLOW. DESPITE SOME MODELS SUGGESTING CONTRARY...CONTINUE TO THINK THAT FOCUS FOR CONVECTION TONIGHT WILL REMAIN MAINLY NORTH OF THE CWA...THOUGH COULD CLIP THE FAR NORTH...WHERE GENERALLY SLIGHT POPS WERE MAINTAINED LATE EVE THROUGH OVERNIGHT. GIVEN PRESENCE OF MODERATE MUCAPE AND STRONG EFFECTIVE DEEP LAYER SHEAR...IF ANY STORMS DO OCCUR OVER THE FAR NORTH...STRONGER STORMS COULD YIELD ISOLATED SEVERE HAIL. LOW TEMPS WILL RANGE FROM MID 40S IN FAR NORTHEAST NEAR THE LAKE TO AROUND 60 IN THE SOUTHWEST CWA. WEDNESDAY AND WEDNESDAY NIGHT... MAIN UNCERTAINTY IS WITH TIMING OF SFC WARM FRONT LIFTING NORTH THROUGH CWA...THOUGH HAVE SOME CONCERN FOR ELEVATED HIGH-BASED CONVECTION NORTH OF THE WARM FRONT DURING THE MORNING MAINLY NORTH OF I-88. PRIMARY FOCUS SHOULD STILL BE NORTH OF THE CWA...BUT DID ADD A SLIGHT POP FOR AREA MENTIONED ABOVE. BIG STORY TOMORROW IS THE RAPID FLIP TO SUMMER WARMTH AS THE WARM FRONT LIFTS NORTH AS 850/925 MB TEMPS RISE TO LEVELS SUPPORTING AT LEAST LOW-MID 80S IN THE WARM SECTOR. SOME HIGH RES GUIDANCE REALLY SLOWS THE NWD PROGRESS OF THE FRONT TOMORROW...BUT THESE MODELS SUCH AS THE NAM ARE LIKELY AFFECTED BY OUTFLOW FROM OVERNIGHT CONVECTION. THE IL NORTH SHORE WILL LIKELY REMAIN QUITE COOL INTO THE AFTERNOON BUT THEN THE WARM AIR SOUTH OF THE BOUNDARY WILL RUSH IN BY THE LATE AFTERNOON OR EARLY EVENING...WITH TEMPS JUMPING SEVERAL DEGREES. DEWPOINTS WILL ALSO RISE TO CLOSE TO OR AROUND 60 AS THE FRONT LIFTS NORTH...ADDING A BIT OF A MUGGY FEEL TO THE AIRMASS. THE AREA SHOULD BE CAPPED TO CONVECTION ON WEDNESDAY NIGHT WITH NO REAL FOCUS TO BREACH THE CAP SO HAVE MAINTAINED A DRY FCST. OVERNIGHT TEMPS WILL BE NORMAL FOR MID SUMMER IN THE MID AND UPPER 60S. THIS WILL PROVIDE A WARM STARTING POINT FOR THURSDAY. THURSDAY AND THURSDAY NIGHT... CONTINUE TO SUSPECT AFTER EXAMINING FORECAST SOUNDINGS THAT MUCH IF NOT ALL OF THE AREA COULD SEE A MAINLY DRY DAYTIME WITH THE WARM SECTOR FIRMLY IN PLACE AND A STRONG CAP INDICATED. MOST OF THE MIDLEVEL SHORTWAVE FORCING DURING DAY SHOULD AT MOST SKIRTH THE FAR NORTHWEST CWA AND SFC COLD FRONT WILL BE WELL BACK TO THE WEST UNTIL THE NIGHTTIME. HAVE MAINTAINED GENERAL IDEA OF GRADUALLY SPREADING IN CHANCE POPS BUT BASED ON TRENDS TODAY...COULD FORSEE NEEDING TO LOWER THESE. THIS IS DESPITE HIGHS AGAIN IN THE MID 80S AND DEWPOINTS AROUND 60 SUPPORTING MODERATE MLCAPE VALUES. MORE FAVORABLE FORCING WILL ARRIVE DURING THE EVENING AND THEN MOISTURE CONVERGENCE ASSOCIATED WITH THE APPROACHING COLD FRONT WILL SUPPORT HIGHER SHOWER/TSTM COVERAGE OVERNIGHT. ARGUING AGAINST WIDESPREAD SEVERE STORMS WILL BE DIURNALLY UNFAVORABLE TIMING...BUT ESPECIALLY WESTERN CWA COULD HAVE ENOUGH INSTABILITY STILL IN PLACE ALONG WITH STRONG DEEP LAYER SHEAR TO SUPPORT A WIND/HAIL THREAT. WITH FRONT REMAINING TO THE WEST THROUGH THE NIGHT...OVERNIGHT TEMPS WILL AGAIN BE QUITE MILD IN THE MID 60S. FRIDAY... REMAINS OF OVERNIGHT CONVECTION SHOULD BE MOVING INTO EAST/SOUTHEAST CWA DURING MORNING...BUT WITH COLD FRONT ONLY MAKING SLOW PROGRESS AND AIR MASS STILL BEING WARM/MOST...WILL HAVE TO WATCH FOR REGENERATION OF STRONGER CONVECTION IN THE SOUTHEAST DURING THE AFTERNOON INTO THE EARLY EVENING. 850/925 MB TEMPS WILL REMAIN IN TEENS CELSIUS THROUGH AFTN SO HIGHS SHOULD REACH THE LOWER-MID 70S. LONG TERM...FRIDAY NIGHT THROUGH TUESDAY... UNLIKE WHAT WE HAVE SEEN AFTER PREVIOUS WARM SPELLS THIS SPRING...WE DO NOT LOOK TO RETURN TO A MUCH COOLER THAN NORMAL PATTERN AFTER THE PASSAGE OF THE LATE WEEK SYSTEM. THE JET STREAM PATTERN LOOKS TO REMAIN MORE ZONAL...WHICH WILL SUPPORT NORMAL TO SLIGHTLY ABOVE NORMAL TEMPS AND POSSIBLY MORESO AS PER 12Z OPERATIONAL EUROPEAN MODEL EARLY NEXT WEEK. UNCERTAINTY INCREASES IN THE OPERATIONAL AND ENSEMBLE MODELS...BUT IT APPEARS AFTER A PRIMARILY DRY SATURDAY...THE PATTERN COULD BE A BIT UNSETTLED WITH PERIODIC TSRA CHANCES. TIMING IS THE MAIN QUESTION AS THE GFS IS MUCH MORE PROGRESSIVE WITH THE NEXT SYSTEM. AS ALLUDED TO ABOVE...THIS WILL ALSO IMPACT HOW WARM TEMPERATURES GET EARLY NEXT WORK WEEK. CONFIDENCE IS ALSO LOWER ON WHICH DAYS ARE MOST SYNOPTICALLY FAVORABLE FOR ONSHORE FLOW KEEPING AT LEAST PORTIONS OF THE LAKEFRONT MUCH COOLER THAN INLAND. RC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * ISOLATED -TSRA/-SHRA POSSIBLE LATE TONIGHT INTO EARLY WEDNESDAY MORNING. BEST CHANCES NORTH. * WARM FROPA WEDNESDAY...MDW FIRST AND THEN ORD. KJB //DISCUSSION...UPDATED 00Z... EASTERLY WINDS WILL CONTINUE ACROSS THE TERMINALS TONIGHT INTO EARLY WEDNESDAY AS LOW PRESSURE SHIFTS ACROSS KANSAS. A WARM FRONT...EXTENDING EASTWARD FROM THIS LOW...IS EXPECTED TO MAKE A NORTHWARD TREK ACROSS THE AREA BY WEDNESDAY AFTERNOON. ONCE THIS FRONT PASSES NORTH OF THE TERMINALS...THE WINDS WILL TURN SOUTHERLY. ALTHOUGH CONFIDENCE IS HIGH WITH THIS WARM FRONT LIFTING NORTH OF THE TERMINALS WEDNESDAY AFTERNOON...CONFIDENCE ON THE EXACT TIMING OF THIS SOUTHERLY WIND SHIFT...PARTICULARLY AT KORD AND KMDW REMAINS A BIT LOW AT THIS TIME. THE OTHER SLIGHT CONCERN...MAINLY FOR TONIGHT IS THE POTENTIAL FOR CONVECTIVE ACTIVITY NEAR THE TERMINALS. REGIONAL SATELLITE IMAGERY LATE THIS AFTERNOON INDICATES AN AREA OF ALTO CUMULUS MOVING ACROSS NORTHERN ILLINOIS. THIS IS AN INDICATION OF THE PRESENCE OF SOME VERY STEEP MID LEVEL LAPSE RATES. THERE IS EVEN AN AREA OF SHOWERS CURRENTLY DEVELOPING ACROSS PORTIONS OF EASTERN ILLINOIS AND INTO INDIANA ALONG THIS ACTIVITY. OVERALL...IT STILL APPEARS THAT AS THE LOWER LEVEL WIND FIELD KICKS UP LATER THIS EVENING...THAT THE ASSOCIATED INCREASE IN MOISTURE WILL LEAD TO SCATTERED THUNDERSTORM DEVELOPMENT ACROSS SOUTHERN WISCONSIN AND EASTERN IOWA...AND POTENTIALLY INTO FAR NORTHERN ILLINOIS AS WELL. IT IS POSSIBLE THAT AN ISOLATED STORM COULD IMPACT THE TERMINALS LATER TONIGHT...HOWEVER...WITH THE BETTER FOCUS LIKELY REMAINING TO THE NORTH OF MOST TERMINALS...I HAVE CONTINUED WITH A DRY FORECAST AT THIS TIME. THE BEST TIMING FOR THIS ACTIVITY WILL LIKELY BE AFTER 04-05 UTC THIS EVENING THROUGH EARLY WEDNESDAY MORNING. RELATIVELY WARM TEMPERATURES ALOFT...SHOULD LIMIT THUNDERSTORM DEVELOPMENT ACROSS THE AREA DURING THE DAY WEDNESDAY. KJB //ORD AND MDW CONFIDENCE...UPDATED 03Z... * HIGH WITH WIND SPEED/DIRECTION TONIGHT...WITH LOW-MEDIUM WITH FROPA TIMING WEDNESDAY. * HIGH WITH PREVAILING -TSRA/-SHRA TO STAY NORTH OF THE TERMINALS...LOW WITH ANY ISOLATED STORMS NEAR THE TERMINALS. KJB //OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z... * THURSDAY...CHANCE OF TSRA IN THE AFTERNOON. GUSTY SOUTHERLY WINDS. * THURSDAY NIGHT...TSRA LIKELY. * FRIDAY...CHANCE OF TSRA. GUSTY WESTERLY WINDS. * SATURDAY...DRY/VFR. * SUNDAY AND MONDAY...CHANCE OF TSRA. KJB && .MARINE... 302 PM CDT HIGH PRESSURE EXTENDS FROM HUDSON BAY TO THE MID ATLANTIC WHILE LOW PRESSURE REMAINS NEARLY STATIONARY AND SLOWLY DEEPENS OVER THE CENTRAL PLAINS. A WARM FRONT EXTENDING EAST FROM THE LOW...THROUGH THE OHIO VALLEY WILL REMAIN NEARLY STATIONARY...WITH ANY NORTHWARD PROGRESS BLOCKED BY THE HIGH. THIS WILL KEEP BRISK EASTERLY FLOW OVER LAKE MICHIGAN UNTIL THE WARM FRONT CAN PUSH TO THE NORTH. BY LATE WEDNESDAY MORNING...THE HIGH WILL BEGIN TO SLIDE TO THE EAST...ALLOWING THE WARM FRONT TO SURGE NORTHWARD. THE PARENT LOW IS EXPECTED TO TRACK TO THE NORTHEAST AND BECOME ELONGATED THROUGH WEDNESDAY NIGHT AND INTO THURSDAY...WITH THE WARM FRONT REACHING THE FAR NORTH END OF THE LAKE BY THURSDAY AFTERNOON...WITH WINDS TURNING SOUTHERLY. THE WARM FRONT SHOULD FINALLY REACH THE FAR SOUTHERN TIP OF THE LAKE BY LATE WEDNESDAY MORNING...ALLOWING FLOW TO TURN OFFSHORE OF THE INDIANA COAST. THE FRONT SHOULD PUSH SOUTH OF THE ILLINOIS NEARSHORE WATERS BY LATE AFTERNOON...SO WILL NOT MAKE ANY CHANGES TO THE GOING SMALL CRAFT ADVISORY AT THIS TIME. THE SOUTHERLY GRADIENT WILL TIGHTEN THURSDAY INTO EARLY FRIDAY...ALLOWING SOUTHERLY WINDS TO STRENGTHEN...BUT VERY WARM AIR OVERSPREADING THE COLD LAKE WATER SHOULD HELP LIMIT MIXING...ESPECIALLY OVER THE OPEN WATERS. THE NEARSHORE WATERS ARE BEGINNING TO GET A BIT WARMER...SO THERE COULD BE BETTER MIXING THERE AND WIND SPEEDS MAY FLIRT WITH GALE FORCE...BUT FOR NOW...FEEL THAT 30KT SOUTHERLY WINDS SHOULD BE THE PREVAILING CONDITION FOR THURSDAY INTO EARLY FRIDAY AFTERNOON. BY LATE FRIDAY AFTERNOON OR EARLY FRIDAY EVENING...THE LOW WILL TRACK NORTH OF THE GREAT LAKES TO NEAR JAMES BAY. AN ASSOCIATED COLD FRONT WILL SWEEP ACROSS THE LAKE FRIDAY AFTERNOON...TURNING WINDS TO WESTERLY BY FRIDAY EVENING. HIGH PRESSURE WILL THEN BUILD ACROSS THE LAKE BEGINNING FRIDAY NIGHT AND REMAINING IN PLACE INTO SUNDAY MORNING. WHILE THE HIGH PRESSURE RESIDES OVER THE LAKE...WINDS SHOULD BE RELATIVELY LIGHT WITH LAKE BREEZE DEVELOPMENT POSSIBLE. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM WEDNESDAY. SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 PM WEDNESDAY. && $$ 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...UPDATED
NWS CHICAGO/ROMEOVILLE IL
912 PM CDT TUE MAY 6 2014 .DISCUSSION... 909 PM CDT CONVECTION DEVELOPING ACROSS THE FAR NORTH METRO PROMPTED A SPECIAL WEATHER STATEMENT ISSUANCE. THE FORECAST WAS UPDATED TO REFLECT SLIGHTLY HIGHER CHANCES OF THUNDER NORTH OF INTERSTATE 80 THE REST OF TONIGHT...AS WELL AS TO MAKE SOME HOURLY FORECAST TEMPERATURE ADJUSTMENTS. THE SURFACE STATIONARY FRONT REMAINS DRAPED WELL TO OUR SOUTH THIS EVE WITH 00Z RAOBS AND CURRENT PROFILER ANALYSIS INDICATING A 40-45 KT SRLY LOW-LEVEL JET HAVING DEVELOPED NORTH OF THIS INTO IA AND ACROSS NORTHERN IL. THIN ARCS OF TCU WERE NOTED ON LATE DAY VISIBLE SATELLITE AND OBSERVATIONS HAVE INDICATED AN INCREASING LAYER OF 8K-10K FT CIGS. THE 00Z DVN RAOB AND AREA AMDAR SOUNDINGS WERE INDICATING A MOISTENING AROUND THAT 800-750MB LAYER...WHICH WHEN LIFTED FROM THAT LAYER ON THE DVN SOUNDING WOULD PROVIDE OVER 1500 J/KG OF MUCAPE...THOUGH WITH STILL A MINOR CAP. AS A SUBTLE SHORT WAVE NEAR KANSAS CITY PROGRESSES NORTHEAST AND OVERALL MOISTURE TRANSPORT STRENGTHENS...WOULD EXPECT TO SEE THAT SLIGHT CAPPING OVERCOME WITH ISOLATED TO SCATTERED CONVECTION DEVELOPING ACROSS THE EASTERN IA/SOUTHERN WI REGION...AND POSSIBLY NORTHERN IL...ESPECIALLY GIVEN CURRENT STORM WAS ALREADY ABLE TO DEVELOP. IN ADDITION...THE TREND WITH THE HOURLY-RAN HRRR HAS BEEN TO INCREASE COVERAGE OF SHOWERS/STORMS EARLY OVERNIGHT...WHICH GIVEN CURRENT OBSERVATIONAL ANALYSIS MAKES SENSE. HAVE BOOSTED POPS SOME OVER THE NORTHERN TWO TIERS OF COUNTIES BUT REMAIN IN THE CHANCE CATEGORY. GIVEN THE RADAR TRENDS WITH THE MCHENRY/LAKE COUNTY STORM...HAVING SPRUNG TO 40 DBZ OVER 35K FT WITHIN THREE SCANS OF DEVELOPING...COULD STILL SEE AN ELEVATED HAILER OR TWO ACROSS FAR NORTHERN ILLINOIS. THE ENVIRONMENT FOR THESE REMAINS MORE SUPPORTIVE TO THE WEST AND NORTHWEST OF THE LOCAL AREA. THE MARINE LAYER CONTINUED TO RE-INFORCE ITSELF EARLY THIS EVE ACROSS THE NORTH AND CENTRAL PARTS OF THE CHICAGO METRO...WITH SOME MID 40S ALONG THE LAKE SHORE AND LOWER 50S STARTING TO REACH SOME OUTLYING AREAS. DID ADJUST MINS DOWN BUT INDICATED SORT OF A LEVELING OFF TREND TO THIS TEMPERATURE FALL...WITH EVEN POTENTIAL RISING LATE GIVEN INCREASING SURFACE DEW POINTS. LOOKING AHEAD TO WEDNESDAY...STILL SOME POSSIBILITY TO SEE ISOLATED CONVECTION IN THE MORNING AS A WEAK SHORT WAVE PASSES...AND THE 00Z NAM CONTINUES TO SHOW THIS SUBTLE FEATURE. COULD ALSO BE SOME FOG DEVELOPING ACROSS FAR SOUTHERN LAKE MICHIGAN DURING THE MORNING AS THE WARM FRONT AND HIGH DEW POINTS BUTT UP AGAINST THE COOL LAKE. WITH THE WARM FRONT LIKELY TO PROGRESS SLOWER OVER THE MARINE LAYER...IT COULD INDUCE THE FOG. HAVE NOT ADDED INTO THE FORECAST AT THIS TIME BUT SOMETHING WE WILL WATCH AS THAT WOULD POSSIBLY MOVE INTO LAKE ADJACENT AREAS OF THE CHICAGO METRO. MTF && .PREV DISCUSSION... 329 PM CDT SHORT TERM...TONIGHT THROUGH FRIDAY... PRIMARY FORECAST CONCERNS ARE WITH HOW WARM TEMPERATURES GET TOMORROW AND THURSDAY AND ON THUNDERSTORM POTENTIAL. W/V IMAGERY SHOWS THE ONGOING AMPLIFICATION OF UPPER RIDGING OVER THE MIDWEST INDUCED BY A DEEP TROUGH/CLOSED LOW OVER THE SOUTHWEST US. AT THE SURFACE...LOW PRESSURE IS DEVELOPING OVER THE SOUTHERN HIGH PLAINS WITH THE VERY STRONG WARM FRONT THAT HAS BEEN IN PLACE OVER THE REGION THE PAST FEW DAYS STRETCHING ACROSS DOWNSTATE IL AND IN. STRONG WAA ALOFT NORTH OF THE BOUNDARY HAS ALLOWED FOR TEMPERATURES TO WARM ABOVE 70 SOUTH OF I-80...WHILE ONSHORE FLOW HAS RESULTED IN ANOTHER COOL DAY FOR LAKESHORE AREAS. TONIGHT... AS THE SFC WARM FRONT INCHES NORTH...A STRONG LOW LEVEL JET WILL DEVELOP WITH GOOD MOISTURE TRANSPORT AND CONVERGENCE FOCUSED ON THE NOSE OF THE LLJ INTO NORTHEAST IA AND FAR SOUTHERN WI. GUIDANCE ALSO HINTS AT A MIDLEVEL SHORTWAVE RIDING IN ON SOUTHWEST FLOW. DESPITE SOME MODELS SUGGESTING CONTRARY...CONTINUE TO THINK THAT FOCUS FOR CONVECTION TONIGHT WILL REMAIN MAINLY NORTH OF THE CWA...THOUGH COULD CLIP THE FAR NORTH...WHERE GENERALLY SLIGHT POPS WERE MAINTAINED LATE EVE THROUGH OVERNIGHT. GIVEN PRESENCE OF MODERATE MUCAPE AND STRONG EFFECTIVE DEEP LAYER SHEAR...IF ANY STORMS DO OCCUR OVER THE FAR NORTH...STRONGER STORMS COULD YIELD ISOLATED SEVERE HAIL. LOW TEMPS WILL RANGE FROM MID 40S IN FAR NORTHEAST NEAR THE LAKE TO AROUND 60 IN THE SOUTHWEST CWA. WEDNESDAY AND WEDNESDAY NIGHT... MAIN UNCERTAINTY IS WITH TIMING OF SFC WARM FRONT LIFTING NORTH THROUGH CWA...THOUGH HAVE SOME CONCERN FOR ELEVATED HIGH-BASED CONVECTION NORTH OF THE WARM FRONT DURING THE MORNING MAINLY NORTH OF I-88. PRIMARY FOCUS SHOULD STILL BE NORTH OF THE CWA...BUT DID ADD A SLIGHT POP FOR AREA MENTIONED ABOVE. BIG STORY TOMORROW IS THE RAPID FLIP TO SUMMER WARMTH AS THE WARM FRONT LIFTS NORTH AS 850/925 MB TEMPS RISE TO LEVELS SUPPORTING AT LEAST LOW-MID 80S IN THE WARM SECTOR. SOME HIGH RES GUIDANCE REALLY SLOWS THE NWD PROGRESS OF THE FRONT TOMORROW...BUT THESE MODELS SUCH AS THE NAM ARE LIKELY AFFECTED BY OUTFLOW FROM OVERNIGHT CONVECTION. THE IL NORTH SHORE WILL LIKELY REMAIN QUITE COOL INTO THE AFTERNOON BUT THEN THE WARM AIR SOUTH OF THE BOUNDARY WILL RUSH IN BY THE LATE AFTERNOON OR EARLY EVENING...WITH TEMPS JUMPING SEVERAL DEGREES. DEWPOINTS WILL ALSO RISE TO CLOSE TO OR AROUND 60 AS THE FRONT LIFTS NORTH...ADDING A BIT OF A MUGGY FEEL TO THE AIRMASS. THE AREA SHOULD BE CAPPED TO CONVECTION ON WEDNESDAY NIGHT WITH NO REAL FOCUS TO BREACH THE CAP SO HAVE MAINTAINED A DRY FCST. OVERNIGHT TEMPS WILL BE NORMAL FOR MID SUMMER IN THE MID AND UPPER 60S. THIS WILL PROVIDE A WARM STARTING POINT FOR THURSDAY. THURSDAY AND THURSDAY NIGHT... CONTINUE TO SUSPECT AFTER EXAMINING FORECAST SOUNDINGS THAT MUCH IF NOT ALL OF THE AREA COULD SEE A MAINLY DRY DAYTIME WITH THE WARM SECTOR FIRMLY IN PLACE AND A STRONG CAP INDICATED. MOST OF THE MIDLEVEL SHORTWAVE FORCING DURING DAY SHOULD AT MOST SKIRTH THE FAR NORTHWEST CWA AND SFC COLD FRONT WILL BE WELL BACK TO THE WEST UNTIL THE NIGHTTIME. HAVE MAINTAINED GENERAL IDEA OF GRADUALLY SPREADING IN CHANCE POPS BUT BASED ON TRENDS TODAY...COULD FORSEE NEEDING TO LOWER THESE. THIS IS DESPITE HIGHS AGAIN IN THE MID 80S AND DEWPOINTS AROUND 60 SUPPORTING MODERATE MLCAPE VALUES. MORE FAVORABLE FORCING WILL ARRIVE DURING THE EVENING AND THEN MOISTURE CONVERGENCE ASSOCIATED WITH THE APPROACHING COLD FRONT WILL SUPPORT HIGHER SHOWER/TSTM COVERAGE OVERNIGHT. ARGUING AGAINST WIDESPREAD SEVERE STORMS WILL BE DIURNALLY UNFAVORABLE TIMING...BUT ESPECIALLY WESTERN CWA COULD HAVE ENOUGH INSTABILITY STILL IN PLACE ALONG WITH STRONG DEEP LAYER SHEAR TO SUPPORT A WIND/HAIL THREAT. WITH FRONT REMAINING TO THE WEST THROUGH THE NIGHT...OVERNIGHT TEMPS WILL AGAIN BE QUITE MILD IN THE MID 60S. FRIDAY... REMAINS OF OVERNIGHT CONVECTION SHOULD BE MOVING INTO EAST/SOUTHEAST CWA DURING MORNING...BUT WITH COLD FRONT ONLY MAKING SLOW PROGRESS AND AIR MASS STILL BEING WARM/MOST...WILL HAVE TO WATCH FOR REGENERATION OF STRONGER CONVECTION IN THE SOUTHEAST DURING THE AFTERNOON INTO THE EARLY EVENING. 850/925 MB TEMPS WILL REMAIN IN TEENS CELSIUS THROUGH AFTN SO HIGHS SHOULD REACH THE LOWER-MID 70S. LONG TERM...FRIDAY NIGHT THROUGH TUESDAY... UNLIKE WHAT WE HAVE SEEN AFTER PREVIOUS WARM SPELLS THIS SPRING...WE DO NOT LOOK TO RETURN TO A MUCH COOLER THAN NORMAL PATTERN AFTER THE PASSAGE OF THE LATE WEEK SYSTEM. THE JET STREAM PATTERN LOOKS TO REMAIN MORE ZONAL...WHICH WILL SUPPORT NORMAL TO SLIGHTLY ABOVE NORMAL TEMPS AND POSSIBLY MORESO AS PER 12Z OPERATIONAL EUROPEAN MODEL EARLY NEXT WEEK. UNCERTAINTY INCREASES IN THE OPERATIONAL AND ENSEMBLE MODELS...BUT IT APPEARS AFTER A PRIMARILY DRY SATURDAY...THE PATTERN COULD BE A BIT UNSETTLED WITH PERIODIC TSRA CHANCES. TIMING IS THE MAIN QUESTION AS THE GFS IS MUCH MORE PROGRESSIVE WITH THE NEXT SYSTEM. AS ALLUDED TO ABOVE...THIS WILL ALSO IMPACT HOW WARM TEMPERATURES GET EARLY NEXT WORK WEEK. CONFIDENCE IS ALSO LOWER ON WHICH DAYS ARE MOST SYNOPTICALLY FAVORABLE FOR ONSHORE FLOW KEEPING AT LEAST PORTIONS OF THE LAKEFRONT MUCH COOLER THAN INLAND. RC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * ISOLATED -TSRA/-SHRA POSSIBLE LATE TONIGHT INTO EARLY WEDNESDAY MORNING. * WARM FROPA WEDNESDAY...MDW FIRST AND THEN ORD. KJB //DISCUSSION...UPDATED 00Z... EASTERLY WINDS WILL CONTINUE ACROSS THE TERMINALS TONIGHT INTO EARLY WEDNESDAY AS LOW PRESSURE SHIFTS ACROSS KANSAS. A WARM FRONT...EXTENDING EASTWARD FROM THIS LOW...IS EXPECTED TO MAKE A NORTHWARD TREK ACROSS THE AREA BY WEDNESDAY AFTERNOON. ONCE THIS FRONT PASSES NORTH OF THE TERMINALS...THE WINDS WILL TURN SOUTHERLY. ALTHOUGH CONFIDENCE IS HIGH WITH THIS WARM FRONT LIFTING NORTH OF THE TERMINALS WEDNESDAY AFTERNOON...CONFIDENCE ON THE EXACT TIMING OF THIS SOUTHERLY WIND SHIFT...PARTICULARLY AT KORD AND KMDW REMAINS A BIT LOW AT THIS TIME. THE OTHER SLIGHT CONCERN...MAINLY FOR TONIGHT IS THE POTENTIAL FOR CONVECTIVE ACTIVITY NEAR THE TERMINALS. REGIONAL SATELLITE IMAGERY LATE THIS AFTERNOON INDICATES AN AREA OF ALTO CUMULUS MOVING ACROSS NORTHERN ILLINOIS. THIS IS AN INDICATION OF THE PRESENCE OF SOME VERY STEEP MID LEVEL LAPSE RATES. THERE IS EVEN AN AREA OF SHOWERS CURRENTLY DEVELOPING ACROSS PORTIONS OF EASTERN ILLINOIS AND INTO INDIANA ALONG THIS ACTIVITY. OVERALL...IT STILL APPEARS THAT AS THE LOWER LEVEL WIND FIELD KICKS UP LATER THIS EVENING...THAT THE ASSOCIATED INCREASE IN MOISTURE WILL LEAD TO SCATTERED THUNDERSTORM DEVELOPMENT ACROSS SOUTHERN WISCONSIN AND EASTERN IOWA...AND POTENTIALLY INTO FAR NORTHERN ILLINOIS AS WELL. IT IS POSSIBLE THAT AN ISOLATED STORM COULD IMPACT THE TERMINALS LATER TONIGHT...HOWEVER...WITH THE BETTER FOCUS LIKELY REMAINING TO THE NORTH OF MOST TERMINALS...I HAVE CONTINUED WITH A DRY FORECAST AT THIS TIME. THE BEST TIMING FOR THIS ACTIVITY WILL LIKELY BE AFTER 04-05 UTC THIS EVENING THROUGH EARLY WEDNESDAY MORNING. RELATIVELY WARM TEMPERATURES ALOFT...SHOULD LIMIT THUNDERSTORM DEVELOPMENT ACROSS THE AREA DURING THE DAY WEDNESDAY. KJB //ORD AND MDW CONFIDENCE...UPDATED 00Z... * HIGH CONFIDENCE WITH WIND SPEED/DIRECTION TONIGHT...WITH LOW MEDIUM CONFIDENCE OF FROPA TRENDS WEDNESDAY. * HIGH CONFIDENCE WITH PREVAILING -TSRA/-SHRA TO STAY NORTH OF THE TERMINALS...LOW CONFIDENCE WITH NEAR ISOLATED DEVELOPMENT. KJB //OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z... * THURSDAY...CHANCE OF TSRA IN THE AFTERNOON. GUSTY SOUTHERLY WINDS. * THURSDAY NIGHT...TSRA LIKELY. * FRIDAY...CHANCE OF TSRA. GUSTY WESTERLY WINDS. * SATURDAY...DRY/VFR. * SUNDAY AND MONDAY...CHANCE OF TSRA. KJB && .MARINE... 302 PM CDT HIGH PRESSURE EXTENDS FROM HUDSON BAY TO THE MID ATLANTIC WHILE LOW PRESSURE REMAINS NEARLY STATIONARY AND SLOWLY DEEPENS OVER THE CENTRAL PLAINS. A WARM FRONT EXTENDING EAST FROM THE LOW...THROUGH THE OHIO VALLEY WILL REMAIN NEARLY STATIONARY...WITH ANY NORTHWARD PROGRESS BLOCKED BY THE HIGH. THIS WILL KEEP BRISK EASTERLY FLOW OVER LAKE MICHIGAN UNTIL THE WARM FRONT CAN PUSH TO THE NORTH. BY LATE WEDNESDAY MORNING...THE HIGH WILL BEGIN TO SLIDE TO THE EAST...ALLOWING THE WARM FRONT TO SURGE NORTHWARD. THE PARENT LOW IS EXPECTED TO TRACK TO THE NORTHEAST AND BECOME ELONGATED THROUGH WEDNESDAY NIGHT AND INTO THURSDAY...WITH THE WARM FRONT REACHING THE FAR NORTH END OF THE LAKE BY THURSDAY AFTERNOON...WITH WINDS TURNING SOUTHERLY. THE WARM FRONT SHOULD FINALLY REACH THE FAR SOUTHERN TIP OF THE LAKE BY LATE WEDNESDAY MORNING...ALLOWING FLOW TO TURN OFFSHORE OF THE INDIANA COAST. THE FRONT SHOULD PUSH SOUTH OF THE ILLINOIS NEARSHORE WATERS BY LATE AFTERNOON...SO WILL NOT MAKE ANY CHANGES TO THE GOING SMALL CRAFT ADVISORY AT THIS TIME. THE SOUTHERLY GRADIENT WILL TIGHTEN THURSDAY INTO EARLY FRIDAY...ALLOWING SOUTHERLY WINDS TO STRENGTHEN...BUT VERY WARM AIR OVERSPREADING THE COLD LAKE WATER SHOULD HELP LIMIT MIXING...ESPECIALLY OVER THE OPEN WATERS. THE NEARSHORE WATERS ARE BEGINNING TO GET A BIT WARMER...SO THERE COULD BE BETTER MIXING THERE AND WIND SPEEDS MAY FLIRT WITH GALE FORCE...BUT FOR NOW...FEEL THAT 30KT SOUTHERLY WINDS SHOULD BE THE PREVAILING CONDITION FOR THURSDAY INTO EARLY FRIDAY AFTERNOON. BY LATE FRIDAY AFTERNOON OR EARLY FRIDAY EVENING...THE LOW WILL TRACK NORTH OF THE GREAT LAKES TO NEAR JAMES BAY. AN ASSOCIATED COLD FRONT WILL SWEEP ACROSS THE LAKE FRIDAY AFTERNOON...TURNING WINDS TO WESTERLY BY FRIDAY EVENING. HIGH PRESSURE WILL THEN BUILD ACROSS THE LAKE BEGINNING FRIDAY NIGHT AND REMAINING IN PLACE INTO SUNDAY MORNING. WHILE THE HIGH PRESSURE RESIDES OVER THE LAKE...WINDS SHOULD BE RELATIVELY LIGHT WITH LAKE BREEZE DEVELOPMENT POSSIBLE. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM WEDNESDAY. SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 PM WEDNESDAY. && $$ 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
NWS CHICAGO/ROMEOVILLE IL
407 AM CDT MON MAY 5 2014 .DISCUSSION... 249 AM CDT EARLY THIS MORNING CONSIDERABLE HIGH-BASED CLOUDS WERE SLIDING EAST ACROSS THE REGION. THIS WAS ASSOCIATED WITH A MID-LVL BOUNDARY THAT HAD STRONG ASCENT OF PARCELS AND GOOD LAPSE RATES. AS A RESULT A FEW SHOWERS/THUNDERSTORMS HAVE DEVELOPED ALONG A NORTHEAST IOWA TO CENTRAL IN LINE. HI-RES LCL GUIDANCE INDICATES THE TIMEFRAME TO BE NARROW...AND LIKELY COMING TO AN END ARND DAYBREAK. WITH THE CONTINUED EASTERLY FLOW AT THE SFC...DEW POINTS HAVE STRUGGLED TO RISE FROM THE UPR 20S IN MOST LOCATIONS. EXPECT ARND DAYBREAK THESE DEW POINTS SHUD MOISTEN SLIGHTLY TO THE LOW 30S. EASTERLY FLOW WILL PERSIST WITH THE SFC RIDGE CENTERED NORTH OF THE FORECAST AREA. TEMPS WILL BE A LITTLE WARMER THIS AFTN FOR THE BULK OF THE AREA...REACHING THE LOW/MID 60S NORTH OF I-80...MEANWHILE TO THE SOUTH TEMPS MAY NEAR 70 BY LATE THIS AFTN. THE PERSISTENT EASTERLY FLOW WILL KEEP AREAS ADJACENT AND DOWN WIND OF LAKE MICHIGAN IN FAR NORTHEAST IL GENERALLY IN THE LOW/MID 50S. CONFIDENCE...HIGH. TONIGHT THROUGH TUESDAY... 500MB HEIGHTS WILL BEGIN TO RISE OVERHEAD...AS BROAD MID-LVL RIDGING COVERS MUCH OF THE CENTRAL CONUS STRETCHING EAST THROUGH THE OHIO-VALLEY. NEAR SFC ANTI-CYCLONIC FLOW LINGERS TONIGHT...BEFORE STARTING TO SLIDE NORTHEAST AND WEAKEN TUESDAY NIGHT. A QUASI-BAROCLINIC FEATURE WILL STRETCH FROM THE NORTHERN PLAINS SOUTHEAST THRU CENTRAL IL/IN TONIGHT THRU TUE...BEFORE CYCLOGENESIS OCCURS OF THE PROGGED SFC LOW OVER THE SOUTHERN PLAINS LATE TONIGHT/EARLY TUE. DRY CONDS SHUD CONTINUE THRU THE BULK OF TUE...THEN AS THE SFC VORT BEGINS TO DRIFT NORTHEAST...THE STALLED BOUNDARY WILL BEGIN TO ADVECT NORTH. STRONG ASCENT OF PARCELS IS POISED TO BE ASSOCIATED WITH THIS FEATURE...ALONG WITH A NARROW CHANNEL OF INCREASED INSTABILITY...THUS TSRA/SHRA LATE TUE NIGHT WILL BE POSSIBLE ACROSS THE FORECAST AREA. TEMPS TUE WILL BE SLIGHTLY WARMER...REACHING THE LOW/MID 70S SOUTH OF I-80...AND TO THE NORTH IN THE 60S. MEANWHILE WITH CONTINUED EASTERLY FLOW A LAKE SHADOW EFFECT WILL KEEP TEMPS IN FAR NORTHEAST IL GENERALLY IN THE LOW/MID 50S. DEPENDING ON TIMING OF THE BOUNDARY ADVECTING NORTH WILL CONTROL TUE NGT TEMPS...WHICH COULD RESULT IN A MILD NIGHT. AT THIS TIME HAVE NUDGED THE SOUTHERN HALF OF THE CWFA INTO THE MID/UPR 50S...BUT IF THE BOUNDARY IS QUICKER THIS WOULD HOLD TEMPS ARND 60 TO PSBLY LOW 60S. THE WILDCARD IS ALSO THE CONTINUED DRY CONDS...WITH DEW POINTS IN THE 40S. THIS COULD ALLOW TEMPS TO STILL QUICKLY FALL AFT SUNSET TUE EVE INTO THE UPR 40S/LOW 50S FOR AREAS NORTH OF A LASALLE TO KANKAKEE LINE. CONFIDENCE...HIGH. WEDNESDAY THROUGH THURSDAY... WITH MID-LVL HEIGHTS INCREASING OVERHEAD...EXPECT THE ENVIRONMENT TO SLOWLY BECOME CAPPED AS TEMPS QUICKLY RISE INTO THE 80S. THE BIGGEST CONCERN IS THAT PERHAPS NUDGING TEMPS WARMER MAY NOT BE ENOUGH. COULD SEE TEMPS SOUTH OF I-80 POSSIBLY NEARING 90...MAINLY SOUTH OF A LASALLE TO KANKAKEE LINE. FURTHER NORTH CLOUDS/PRECIP FROM EARLY IN THE DAY SHUD KEEP TEMPS DOWN SLIGHTLY...HOWEVER STILL EXPECT 80-84 TO BECOME COMMON. THE STRONG SOUTHERLY FLOW WILL PREVENT ANY LAKE BREEZE FROM PUSHING INLAND...SO HAVE BOOSTED DOWNTOWN CHICAGO TEMPS TO REFLECT THE URBAN HEAT. THE SFC LOW WILL BE DRIFTING NORTH TO SLIGHTLY NORTHEAST INTO SOUTHEAST SOUTH DAKOTA/SOUTHWEST MINNESOTA WED NGT/EARLY THUR. EXPECT LLVL MOISTURE TO STEADILY ADVECT NORTH...WITH PWAT VALUES NEARING 1.5" AND DEW POINTS APPROACHING 60. A LITTLE CONCERNED LLVL MOISTURE MAY BE A TAD OVERDONE GIVEN THAT PRIOR TO WED NGT THERE IS NOT AN ABUNDANCE OF PRECIP. HOWEVER...HAVE ENOUGH CONFIDENCE IN THE SETUP THAT A STEADY CONVEYOR OF MOISTURE WILL ARRIVE WED NGT. THUR WILL FEATURE CONTINUED CHALLENGES WITH THE FORECAST...ESPECIALLY WITH TIMING OF PRECIP/CONVECTION. THE BEST FORCING AND THREAT FOR SEVERE WEATHER LOOKS TO REMAIN WELL WEST OF THE FORECAST AREA CLOSER TO THE SFC LOW. HAVE NUDGED POPS DOWN SLIGHTLY FOR THUR...AND COULD FEASIBLY SEE MUCH OF THUR BEING DRY. THEN AS THE AFTN PROGRESSES PRECIP COVERAGE SHUD INCREASE. TEMPS THUR SHUD ONCE AGAIN WARM WELL INTO THE MID/UPR 70S BY LATE MORNING...THEN TOP OUT IN THE LOW 80S. THE WARMEST WILL LIKELY BE EAST OF A LASALLE TO CRYSTAL LAKE LINE. CLOUDS WILL HELP MAINTAIN A MILD NIGHT...WITH TEMPS REMAINING IN THE 60S OVERNIGHT. LATE THUR THE SFC LOW WILL BE LIFTING NORTHEAST INTO THE UPPER MIDWEST/NORTHERN GREAT LAKES. A FEW GUIDANCE MEMBERS ARE TRYING TO DEVELOP AN A MOIST CHANNEL WITH ABUNDANT CONVECTION STRETCHING FROM THE OZARKS NORTH THRU THE FORECAST AREA LATE THUR NGT. WITH A DECENT NOCTURNAL LLVL JET OVERHEAD...AND A VERY MOIST ENVIRONMENT...EFFICIENT PRECIP FROM CONVECTION LOOKS POSSIBLE. CONFIDENCE IN TEMPS...HIGH. CONFIDENCE IN CONVECTION TIMING/COVERAGE THUR...MEDIUM. FRIDAY THROUGH THE UPCOMING WEEKEND... FOR THE END OF THE WEEK INTO THE UPCOMING WEEKEND...ENSEMBLES ARE INDICATING THE 500MB RIDGING OVER THE SOUTHEAST STATES TO WEAKEN AND DRIFT EAST OVER THE ATLANTIC WITH WEAK MID-LVL TROUGHING ARRIVING OVER THE CENTRAL CONUS SAT/SUN AND POSSIBLY PERSISTING THRU EARLY NEXT WEEK. GUIDANCE HAS A FRONTAL BOUNDARY ARRIVING EARLY FRI AND PUSHING EAST BY MIDDAY FRI...HOWEVER TIMING OF THIS FEATURE HAS BEEN EVOLVING THUS A LOW CONFIDENCE ON WHEN PRECIP MIGHT COME TO AN END FRI. HAVE BROUGHT POPS DOWN TO LOW CHC...THEN SLT CHC FRI NGT...BUT COULD SEE FRI TRENDING DRY. SFC RIDGE ARRIVES SAT AND WILL BRING A DRY PERIOD FOR THE WEEKEND. THEN ANOTHER WAVE IS PROGGED TO QUICKLY SLIDE EAST FROM THE ROCKIES SAT...ARRIVING FOR THE SECOND HALF OF THE WEEKEND. TEMPS WILL GENERALLY BE NEAR SEASONAL CONDS. HIGH PRESSURE OVERHEAD SAT WILL LIKELY ALLOW A LAKE BREEZE TO DEVELOP. CONFIDENCE...MEDIUM/HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 09Z... * ISOLATED SHRA/TSRA THROUGH SUNRISE. * GUSTY EAST/NORTHEAST WINDS TODAY. CMS //DISCUSSION...UPDATED 09Z... A FEW SHOWERS/SPRINKLES PASSED ACROSS THE TERMINALS IN THE PAST HOUR OR SO WITH AN AREA OF SHOWERS AND A FEW THUNDERSTORMS FROM SOUTHWEST OF ARR TO C09 AND IKK. THE CURRENT MOTION WOULD KEEP THIS ACTIVITY JUST SOUTH OF MDW/GYY IN THE NEXT 1-2 HOURS BUT ANOTHER SHOWER HAS DEVELOPED JUST NORTH OF FEP SO OPTED TO MAINTAIN CURRENT VCSH MENTION THROUGH 12Z FOR THE CHICAGO AREA TERMINALS WITH THE SMALL CHANCE THAT ANY STRONGER CELLS MAY BE STRONG ENOUGH FOR SOME BRIEF LIGHTNING. CMS PREVIOUS 06Z DISCUSSION... AN UPPER LEVEL WAVE MAY AID SHOWER DEVELOPMENT OVERNIGHT THROUGH DAYBREAK ACROSS THE AREA BUT CONFIDENCE REGARDING BOTH LOCATION AND COVERAGE IS FAIRLY LOW. MOST RECENT HIGH RES/SHORT TERM GUIDANCE HAS SHOWN A DECREASE IN EXPECTED COVERAGE. ACTIVITY WILL ALSO BE HIGH BASED WITH VERY DRY LOW LEVELS. HOWEVER... INSTABILITY ALOFT IS SUFFICIENT FOR ISOLATED THUNDERSTORMS. DESPITE THE EXPECTED COVERAGE...DECIDED TO LEAVE THE CURRENT VCSH AND WILL MONITOR TRENDS FOR UPDATES. ACTIVITY THAT DOES DEVELOP WILL BE SHORT IN DURATION WITH THE BEST CHANCES THROUGH 12Z THIS MORNING WITH THE REMAINDER OF THE PERIOD EXPECTED TO BE DRY. EASTERLY WINDS WILL PERSIST THROUGH THE PERIOD. AS THE LOW LEVELS BEGIN TO MIX AFTER SUNRISE COMBINED WITH A TIGHTENING PRESSURE GRADIENT...SPEEDS SHOULD INCREASE INTO THE 12-15KT RANGE WITH GUSTS APPROACHING 20KTS FOR THE DAYLIGHT HOURS WITH SPEEDS/GUSTS DIMINISHING AFTER SUNSET. CMS //ORD AND MDW CONFIDENCE...UPDATED 09Z... * LOW FOR SHRA/TSRA THROUGH SUNRISE. * MEDIUM FOR WINDS THROUGH THE PERIOD. CMS //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY...VFR...CHANCE TSRA TUES NGT. WEDNESDAY...SLGT CHANCE TSRA...MAINLY VFR. THURSDAY...VFR...TSRA LIKELY LATE. FRIDAY...CHANCE SHRA/TSRA...BUT MAINLY VFR. SATURDAY...VFR. RATZER && .MARINE... 240 AM...HIGH PRESSURE OVER ONTARIO AND THE EASTERN LAKES WILL SLOWLY DRIFT EAST TODAY AND TUESDAY AS LOW PRESSURE OVER KANSAS REMAINS NEARLY STATIONARY THROUGH WEDNESDAY. A WARM FRONT EXTENDING EAST FROM THIS LOW WILL LIFT NORTH TO THE SOUTHERN END OF THE LAKE WEDNESDAY AFTERNOON. UNTIL THAT TIME...EAST/NORTHEAST FLOW WILL PREVAIL ACROSS THE LAKE. WIND SPEEDS WILL GRADUALLY INCREASE AS THE WARM FRONT APPROACHES AS THE GRADIENT TIGHTENS. WINDS WILL THEN SHIFT SOUTHERLY SOUTH OF THE WARM FRONT AS IT MOVES NORTH ACROSS THE LAKE WEDNESDAY NIGHT AND THURSDAY. THE LOW OVER THE PLAINS WILL LIFT NORTHEAST TO WESTERN LAKE SUPERIOR BY FRIDAY MORNING AND THEN TO JAMES BAY BY SATURDAY MORNING. A COLD FRONT WILL MOVE ACROSS THE LAKE FRIDAY AND DURING THIS TIME PERIOD A PERIOD OF 30 KT WINDS IS POSSIBLE. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ 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 252 AM CDT Mon May 5 2014 .DISCUSSION... ISSUED 252 AM CDT Mon May 5 2014 SHORT TERM...Today through Wednesday 06z surface analysis showed low pressure over southwest KS with a quasi-stationary boundary extending east through central MO and into southern IL. This has kept a brisk ENE low level flow going locally off Canadian high perched over the Great Lakes. This is producing unseasonably low dew points in the 20s. Despite the dry boundary layer, strong elevated theta-e advection aided by at 50-55 kt low level jet over MO has managed to produce isolated showers just north and east of the local area on the cool side of the 850mb front. A few lightning strikes have even been noted just northwest of Henry. Hi-res models keep this isolated activity northeast of the area over the next few hours and it should fade towards sunrise as the LLJ wanes. The front to our south is progged to shift north near I-70 by late morning before drifting back south again during the afternoon. This brings another day of dry ENE flow to much of the CWA and with little change in the low to mid level airmass highs should again be in the upper 60s north to mid 70s central. Some low 80s will be possible south of I-70. The upper level flow begins to amplify on Tuesday with a digging western trough and downstream ridging building over the Great Lakes. This will push highs a few degrees warmer. The surface boundary is expected to surge north Tuesday night while the first in a series of mid-level waves lifts northeast from the Plains. The bulk of this activity should be north of the CWA though did maintain a strip of slight chance pops over the far north overnight. The local area will be firmly in the warm sector on Wednesday and brisk southerly winds will push highs well above normal, into the middle 80s. Dewpoints getting up into the lower 60s will bring higher humidity back to the region. Dry conditions should hold overnight as storms remain focused well to our north and west. LONG TERM...Thursday through Sunday Surface low pressure is forecast to lift into southern MN with a trailing cold front shifting into IA/MO Thursday evening. Will continue with chance pops west of I-55 Thursday afternoon as upper forcing ahead of the front could bring some scattered storms this far east. A better chance for more widespread t-storms will be tied to the frontal passage overnight. While low level moisture and wind shear could favor some stronger storms, unfavorable diurnal timing looks to mitigate the overall severe threat. A secondary disturbance lifting out of the Plains trough will likely hang the front up over central or eastern IL Friday afternoon/evening and will keep high chance pops going especially east of I-57. High pressure building in behind the front brings drying conditions from the northwest on Saturday. Lower confidence forecast for later in the weekend as a brief period of zonal flow over the central U.S. could see one or two low amplitude waves bring some precip to the Midwest. Model consensus low chance pops for Saturday night and Sunday are reasonable at this point. Upper level heights suggest seasonable temps during this period. 25 && .AVIATION... ISSUED 1126 PM CDT Sun May 4 2014 East-northeast winds have been gusting from 20-25 knots the last few hours, and will continue to be gusty for a few more hours. NAM model suggests some borderline LLWS conditions for a couple hours around 08-09Z, although the RAP is not quite as high, so will leave mention out of the upcoming TAFs. Frontal boundary across the southern third of Illinois may drift northward a bit on Monday before retreating, diminishing winds for a time late morning and into the afternoon, especially from KSPI-KCMI, before picking up again a bit in the evening. Cloud cover expected to remain above 12KFT through the period. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1229 AM CDT MON MAY 5 2014 .DISCUSSION... 826 PM CDT THE MAIN CONCERN TONIGHT IS THE POTENTIAL FOR SOME ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS OVERNIGHT. WATER VAPOR IMAGERY EARLY THIS EVENING INDICATES THAT THE MAIN BELT OF PERTURBED MID/UPPER LEVEL WESTERLIES ARE ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST...ATOP A LOW AMPLITUDE BROAD SCALE RIDGE ACROSS THE SOUTHERN CONUS. THE 00 UTC RAOBS REALLY SHOWS THE STOUT NORTHWEST TO EAST-SOUTHEASTERLY ORIENTED LOWER LEVEL BAROCLINIC ZONE ACROSS THE AREA. FOR EXAMPLE...KGRB REPORTED +1 CELSIUS AT 850 MB...WITH KDVN COMING IN AT +10 CELSIUS AND KSGF COMING IN WITH A SUMMER-LIKE +21 CELSIUS. THIS STRONG BAROCLINIC ZONE WILL ULTIMATELY HELP SET UP SOME GOOD WARM AIR ADVECTION/ISENTROPIC ASCENT TONIGHT IN RESPONSE TO A SOUTH-SOUTHWESTERLY VEERING LOW LEVEL JET. ALTHOUGH AREA RAOBS INDICATE RATHER UNIMPRESSIVE LOWER LEVEL MOISTURE CURRENTLY IN THE 850 TO 700 MB LAYER...IT APPEARS THAT CONTINUED ISENTROPIC ASCENT AND FROTOGENISIS WILL CONTINUE TO HELP MOISTEN THESE LAYERS...WITH HIGHER THETA E AIR LIKELY TO SET UP ACROSS THE AREA OVERNIGHT. GIVEN THAT THIS IS ALL EXPECTED TO OCCUR BENEATH SOME VERY IMPRESSIVE MID LEVEL LAPSE RATES...ELEVATED INSTABILITY SHOULD ALLOW FOR AT LEAST SOME ISOLATED TO WIDELY SCATTERED THUNDERSTORMS TO DEVELOP ACROSS PORTIONS OF THE AREA LATER TONIGHT. IT APPEARS THAT THESE STORMS COULD POSS A SMALL THREAT OF HAIL GIVEN THE COMBINATION OF THE VERY STEEP MID LEVEL LAPSE RATES AND THE FAIRLY STOUT MID/UPPER LEVEL WEST-NORTHWESTERLY WIND FIELD OVER THE AREA. WITH ALL THIS IN MIND...I HAVE ADDED THUNDER TO THE GRIDS AND WILL ALSO ADD THE MENTION IN THE HWO AS WELL. NO OTHER MAJOR CHANGES WERE MADE TO THE GOING FORECAST. KJB //PREV DISCUSSION... 311 PM CDT SYNOPSIS...SCATTERED SHOWERS ARE OVER THE CWA WITH VERY LITTLE PRECIP MAKING IT TO THE SURFACE. THEY SHOULD CONTINUE TO DISSIPATE WITH MONDAY LOOKING WARMER...EXCEPT FOR ALONG THE LAKE. A WARM UP CONTINUES THROUGH THE WEEK WITH MID 80S OR HIGHER POSSIBLE ON THURSDAY. WE ALSO GET INTO AN ACTIVE PATTERN WITH THUNDERSTORMS POSSIBLE TUESDAY NIGHT THROUGH LATE NEXT WEEK. SOME OF THESE STORMS MAY BECOME SEVERE THURSDAY NIGHT INTO FRIDAY. REST OF TODAY THROUGH TUESDAY... NORTHWEST FLOW IS ALOFT AS A LARGE RIDGE IS OVER THE CONUS. A WEAKENING SHORTWAVE TROUGH IS MOVING THROUGH THE REGION WITH SHOWERS SHOWING UP ON RADAR. THE RIDGE MOVES OVERHEAD TUESDAY. AT THE SURFACE...HIGH PRESSURE IS OVER THE REGION AND IT WILL REMAIN IN THE REGION THROUGH MID WEEK. LOW PRESSURE IS OVER THE SOUTHERN PLAINS WITH ITS WARM FRONT EXTENDING THROUGH THE MID MISSISSIPPI VALLEY. THE WARM FRONT WILL REMAIN WELL SOUTH OF THE CWA ACROSS SOUTHERN IL THROUGH TUESDAY. THE SHOWERS OVERHEAD NOW ARE WEAKENING QUICKLY WITH VERY FEW OBS INDICATING RAIN IS REACHING THE SURFACE. SHOULD BE RAIN FREE BY THE LATE AFTERNOON HOURS. GUIDANCE CONTINUES TO INDICATE SHOWERS WILL FORM OVER THE FAR SOUTHERN CWA THIS EVENING AND THEN SPREAD NORTH OVERNIGHT AS WAA SETS UP ALOFT. WITH CONSISTENT GUIDANCE...WENT WITH CHANCE POPS THROUGH EARLY MONDAY MORNING...BUT NOT EXPECTING A HUGE IMPACT ON THE MONDAY MORNING COMMUTE. LOWS TONIGHT WILL DIP IN TO THE LOWER 40S BUT ONLY A FEW ISOLATED SPOTS SHOULD GET INTO THE UPPER 30S AS THICK CLOUD COVER SHOULD LIMIT COOLING. WINDS REMAIN OFF OF THE LAKE MONDAY AND TUESDAY WITH TEMPS EXPECTED AROUND 50 ALONG THE LAKE BOTH DAYS. OUTLYING AREAS WILL WARM NICELY INTO THE 60S MONDAY AND THEN INTO THE LOW 70S TUESDAY. THE EASTERLY WINDS BECOME A BIT GUSTY TUESDAY WITH MAX GUSTS AROUND 25 MPH. OTHERWISE LOOKING AT TWO DRY NICE DAYS. TUESDAY NIGHT THROUGH FRIDAY... THE UPPER LEVEL RIDGE REMAINS OVER THE REGION THROUGH THURSDAY WITH AN OPEN GULF. AN UPPER LEVEL LOW OVER THE SW US FORMS AN OPEN WAVE OVER THE PLAINS THURSDAY AND THE WAVE PASSES TO W OR NW THURSDAY NIGHT. A SECOND WAVE ASSOCIATED WITH THE TROUGH PASSES FRIDAY NIGHT. AT THE SURFACE...THE FIRST LOW OVER THE PLAINS DISSIPATES WHILE A SECOND SURFACE LOW FORMS OVER THE PLAINS TUESDAY NIGHT. THIS LOW LIFTS A WARM FRONT NORTH THROUGH THE REGION WEDNESDAY. THE LOW THEN PASSES OVER WI FRIDAY WITH ITS COLD FRONT MOVING THROUGH THE CWA FRIDAY AS WELL. A WEAK SHORTWAVE MOVES AROUND THE RIDGE TUESDAY NIGHT WITH SHOWERS EXPECTED TO FORM NORTH OF I-80...MOST LIKELY ALONG THE IL/WI STATE LINE. THUNDERSTORMS ARE EXPECTED AS THE WARM FRONT LIFTS THROUGH THE REGION WEDNESDAY MORNING AND AFTERNOON. GUIDANCE NOW FEATURES SOME SIGNIFICANT CAPPING SO WHILE A STORM OR TWO MAY GO SEVERE IF IT CAN REACH THE 2000 J/KG OF CAPE ABOVE THE CAP...FOCUSING ON THURSDAY/FRIDAY FOR THE SEVERE WEATHER THREAT. WILL PROBABLY SEE STORMS MOVE NORTH INTO WI WEDNESDAY EVENING/NIGHT. HOWEVER PWATS WILL BE AN INCH PLUS SO COULD SEE SOME HEAVY DOWNPOURS WITH THE STORMS. WE WILL ENJOY THE WARM SECTOR THURSDAY...AND RAISED HIGH TEMPS INTO THE MID 80S. COULD SEE A FEW STORMS AND CLOUD COVER COULD LIMIT WARMING...BUT HAD ENOUGH CONFIDENCE TO GO INTO AT LEAST THE MID 80S RIGHT NOW. IF WE GET FULL SUNSHINE COULD SEE HIGHS EVEN WARMER THAN CURRENTLY FORECAST. THE LOW PASSES TO THE NORTH THROUGH WI THURSDAY NIGHT/FRIDAY AND ITS COLD FRONT SWINGS THROUGH AT THE SAME TIME. EXPECTING SHOWERS AND STORMS ALONG THE FRONT AND THIS SHOULD BE THE MAIN SEVERE WEATHER THREAT WITH THIS SYSTEM. PWATS REMAIN AT 1-1.25 INCHES SO HEAVY DOWNPOURS WILL BE POSSIBLE. CAPE VALUES ARE BIT MORE MEAGER AT AROUND 1000 J/KG BUT THE FORCING ALONG THE FRONT IS MUCH MORE SUBSTANTIAL. GUIDANCE DIFFERS ON THE SPEED OF THE COLD FRONT SO KEPT A SLIGHT CHANCE OF SHOWERS AND STORMS INTO FRIDAY NIGHT JUST IN CASE. FRIDAY WILL BE COOLER IN THE LOWER 70S AND GUIDANCE INDICATES A SURFACE HIGH MOVES OVER THE REGION FOR THE WEEKEND. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * CHANCE OF SHRA AND POSSIBLY ISOLATED TSRA THROUGH SUNRISE. * GUSTY EAST/NORTHEAST WINDS TODAY. CMS //DISCUSSION...UPDATED 06Z... AN UPPER LEVEL WAVE MAY AID SHOWER DEVELOPMENT OVERNIGHT THROUGH DAYBREAK ACROSS THE AREA BUT CONFIDENCE REGARDING BOTH LOCATION AND COVERAGE IS FAIRLY LOW. MOST RECENT HIGH RES/SHORT TERM GUIDANCE HAS SHOWN A DECREASE IN EXPECTED COVERAGE. ACTIVITY WILL ALSO BE HIGH BASED WITH VERY DRY LOW LEVELS. HOWEVER... INSTABILITY ALOFT IS SUFFICIENT FOR ISOLATED THUNDERSTORMS. DESPITE THE EXPECTED COVERAGE...DECIDED TO LEAVE THE CURRENT VCSH AND WILL MONITOR TRENDS FOR UPDATES. ACTIVITY THAT DOES DEVELOP WILL BE SHORT IN DURATION WITH THE BEST CHANCES THROUGH 12Z THIS MORNING WITH THE REMAINDER OF THE PERIOD EXPECTED TO BE DRY. EASTERLY WINDS WILL PERSIST THROUGH THE PERIOD. AS THE LOW LEVELS BEGIN TO MIX AFTER SUNRISE COMBINED WITH A TIGHTENING PRESSURE GRADIENT...SPEEDS SHOULD INCREASE INTO THE 12-15KT RANGE WITH GUSTS APPROACHING 20KTS FOR THE DAYLIGHT HOURS WITH SPEEDS/GUSTS DIMINISHING AFTER SUNSET. CMS //ORD AND MDW CONFIDENCE...UPDATED 06Z... * LOW FOR SHRA/TSRA THROUGH SUNRISE. * MEDIUM FOR WINDS THROUGH THE PERIOD. CMS //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY...VFR...CHANCE TSRA TUES NGT. WEDNESDAY...SLGT CHANCE TSRA...MAINLY VFR. THURSDAY...VFR...TSRA LIKELY LATE. FRIDAY...CHANCE SHRA/TSRA...BUT MAINLY VFR. SATURDAY...VFR. RATZER && .MARINE... 247 PM CDT HIGH PRESSURE CONTINUES TO SPREAD ACROSS LAKE MICHIGAN THIS AFTERNOON WITH WINDS AND WAVES DIMINISHING. THE HIGH WILL TRANSITION EAST OF THE LAKE TONIGHT AS LOW PRESSURE STARTS TO TAKE SHAPE OVER THE CENTRAL PLAINS. AS THIS OCCURS...NORTHEAST FLOW WILL BEGIN TO FRESHEN UP ACROSS LAKE MICHIGAN WITH WINDS INCREASING BACK INTO THE 10 TO 20 KT RANGE LATER IN THE DAY MONDAY. TUESDAY NIGHT AS THE LOW STARTS TO LIFT INTO THE UPPER MIDWEST...WINDS WILL VEER AROUND TO THE SOUTHEAST AND INCREASE INTO THE 15 TO 25 KT RANGE. THE LOW WILL CONTINUE TO LIFT INTO ONTARIO LATE IN THE WEEK...WITH A COLD FRONT PUSHING ACROSS LAKE MICHIGAN LATE FRIDAY INTO SATURDAY. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ 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 1126 PM CDT Sun May 4 2014 .DISCUSSION... ISSUED 817 PM CDT Sun May 4 2014 Concern for tonight will be with any rain chances across our northern CWA. Shortwave currently moving through central Nebraska continues to move east, and should be moving into western Illinois just before sunrise. Most of the models are reflecting some light rain accumulations north of I-74 late tonight, as lift increases ahead of the wave. However, there is an awful lot of dry air below 500 mb, per our evening sounding, that will have to be overcome. Dew points have dropped into the 20s from Bloomington eastward and with a stiff east wind, no moisture will be advecting in from that direction. Already seeing reports of virga over our northern CWA and this will probably be common for several more hours. The showers last night did manage to eke out some light but measurable amounts in a similar parched atmosphere, so will not rule out the possibility here, but am not expecting more than a hundredth at best. Have included some 30% PoP`s after midnight north of I-74. Increasing lapse rates suggest a couple rumbles of thunder could be possible as well, but will hold off on this for now. Otherwise, little change was needed to the other parts of the forecast. Geelhart && .AVIATION... ISSUED 1126 PM CDT Sun May 4 2014 East-northeast winds have been gusting from 20-25 knots the last few hours, and will continue to be gusty for a few more hours. NAM model suggests some borderline LLWS conditions for a couple hours around 08-09Z, although the RAP is not quite as high, so will leave mention out of the upcoming TAFs. Frontal boundary across the southern third of Illinois may drift northward a bit on Monday before retreating, diminishing winds for a time late morning and into the afternoon, especially from KSPI-KCMI, before picking up again a bit in the evening. Cloud cover expected to remain above 12KFT through the period. Geelhart && .PREV DISCUSSION... ISSUED 300 PM CDT Sun May 4 2014 Despite some minor model differences resolving the short term shortwaves in the quasi-zonal flow, the overall synoptic patterns are in agreement until the day 5-7 time frame. There will not be a major shift in the sensible weather between the short term solutions, with any light rain over the next few days being short-lived and barely measurable. Clouds and temps will show larger differences depending on the track of the waves. Therefore, only made minor adjustments to the ongoing precip forecast. A significant warmup still looks on track for Wed/Thur, as a broad ridge expands into the area. SHORT TERM...Tonight through Tuesday A departing shortwave from today will keep clouds and sprinkles across the north into the evening. The next shortwave will arrive after midnight, triggering additional slight chances of showers north of I-74 through Monday morning. Very little rain accumulation is expected from during that system. The stationary front just south of our forecast area tonight will lift north as a warm front on Monday, allowing areas south of I-70 to see some of the warm sector air mass a couple days early. On Tuesday, the front may slip back south slightly, but the ridging aloft and increasing heights will allow high temps to still climb a few degrees warmer than Monday. Tues should be a dry day with the next disturbance possibly Tuesday night across northern IL. We could see a few light showers from Galesburg to Lacon. LONG TERM...Wednesday through Sunday A much stronger push of warm air will come on Wednesday as the mid level warm front re-develops across northern IL/southern WI, allowing surface temps to climb around 10-12 deg above normal, in the 80-84 range. The MEX extended GFS guidance even has 88 for SPI on Wed. We trended warmer, but we tempered that big of a swing with this update due to some signals from the Canadian and ECMWF of slightly cooler 850mb temps than the GFS/NAM. We will remain firmly entrenched in the warm sector on Thursday but increasing clouds and storm chances may keep highs a few deg cooler than Wed depending on how much morning sunshine/warming occurs. The highest chances of storms this week looks to be Thursday night into Friday morning, with likely PoPs across the board in our forecast area. Due to increasing shear parameters and instability, we could see a few rotating storms with damaging winds and hail possible. Isolated tornadoes can not be ruled out either, but better chances of severe weather should remain west in Missouri and Iowa. Based on SPC Day 5 outlook, our severe potential will be mainly from Knox County to Schuyler County. Our lower severe chances will be aided by poor diurnal timing, as storms will be later Thursday night without the support of surface based instability. Elevated CAPE and shear will still be sufficient for a few vigorous updrafts advancing into western IL however. The cold front should push through IL on Friday, with dry air already across most of our counties by afternoon. Noticeably cooler air will return for Friday night and Saturday. The ECMWF is indicating a secondary wave of low pressure moving up the Ohio River Valley on Saturday, which could keep shower/storm chances in our southeast counties. The GFS does not resolve that feature, and keeps rain chances south of IL. For Sunday, the GFS introduces a wave of low pressure that the ECMWF does not show, so AllBlend PoPs were skewed upwards each day next weekend by alternating days of storm systems. Will keep any precip in the low chance or slight chance category due to the model differences. Some return of warmer air is forecast for Sunday in both the GFS and ECMWF, so that trend was allowed in the forecast. Shimon && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
202 PM EDT MON MAY 5 2014 .UPDATE... ISSUED AT 202 PM EDT MON MAY 5 2014 GOOD TEMPERATURE GRADIENT FROM NORTH TO SOUTH ACROSS THE AREA THIS AFTERNOON WITH MID 60S JUST NORTH OF FLEMING COUNTY TO THE MID 80S ACROSS SOUTHERN KENTUCKY. THUS...THE ONLY PLACE THAT MAY STRUGGLE TO GET INTO THE 80S TODAY MAY BE THE FAR NORTH. THIS SEEMS TO BE HANDLED WELL BY CURRENT FORECAST. THUS...NO CHANGES WARRANTED THIS AFTERNOON. UPDATE ISSUED AT 922 AM EDT MON MAY 5 2014 A WARM AND DRY DAY IS ON TAP ACROSS THE COAL FIELDS. TEMPERATURES ARE ALREADY ABOUT 5 TO 6 DEGREES AHEAD OF YESTERDAYS DIURNAL CURVE...SO GOING TO UP TEMPERATURES MORE SOLIDLY INTO THE MID 80S. A FEW 87 OR 88 DEGREE READINGS CANNOT BE RULED OUT GIVEN THE DRY SURFACE CONDITIONS IN PLACE ACROSS SOUTHEAST KENTUCKY. GIVEN THE WARMER TEMPS AND DRY SFC CONDITIONS...HAVE ISSUED AN SPS FOR AN ELEVATED FIRE DANGER THIS AFTERNOON AND HIGHLIGHTED IN THE HWO. ALSO...SCALED BACK THE SKY COVER WITH ONLY A VERY SCATTERED MID LEVEL DECK ARRIVING FROM THE NORTHWEST THROUGH THE AFTERNOON. OVERALL...WE SHOULD AVERAGE OUT TO A MOSTLY SUNNY SKY THROUGH THE DAY. UPDATE ISSUED AT 740 AM EDT MON MAY 5 2014 HOURLY GRIDS WERE UPDATED BASED ON RECENT SATELLITE...RADAR AND OBSERVATION TRENDS. CONVECTION SO FAR REMAINS NORTH AND EAST OF THE CWA...BUT RECENT NEAR TERM GUIDANCE SUGGESTS THAT A SHOWER OR TWO IS POSSIBLE ACROSS THE NORTHERN AND EASTERN FRINGES OF THE CWA THROUGH MIDDAY. CONFIDENCE IN THIS IS LOW...SO WE HAVE CONTINUED WITH SLIGHT CHANCE POPS IN THIS AREA. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 345 AM EDT MON MAY 5 2014 EARLY THIS MORNING...A NEARLY STATIONARY BOUNDARY EXTENDED EAST INTO THE COMMONWEALTH FROM LOW PRESSURE OVER THE CENTRAL PLAINS STATES. THIS BOUNDARY SEPARATED A MUCH DRIER AIRMASS ACROSS THE NORTHERN TWO THIRDS OF THE CWA FROM A SLIGHTLY MORE MOIST AIRMASS ACROSS THE SOUTHERN THIRD OF THE CWA. SFC DEWPOINTS CURRENTLY OVER NORTHEAST KY ARE IN THE LOWER 30S WITH DEWPOINTS IN THE LOWER 50S ALONG THE TN BORDER. A WEAK SHORTWAVE WORKING AROUND MID LEVEL RIDGING CENTERED OVER MEXICO AND EXTENDING NORTH INTO THE PLAINS AND LOWER MS VALLEY WAS INTERACTING WITH THE BAROCLINIC ZONE AND A LOW LEVEL JET OVER THE LOWER OH VALLEY REGION TO PRODUCE CONVECTION FROM NORTHEASTERN IL SOUTHEAST INTO CENTRAL WV. OTHER CONVECTION WAS A BIT FURTHER SOUTHWEST OF THIS ACTIVITY AND EARLIER PASSED NEAR KIND AND WAS PASSING NEAR THE KCVG VICINITY. THROUGH THE PERIOD...SOME AMPLIFICATION IS EXPECTED TO THE PATTERN WITH TROUGHING GRADUALLY DEPARTING THE NORTHEASTERN CONUS AND TROUGHING DIGGING SOUTH INTO THE DESERT SOUTHWEST LEADING TO A WESTERN CONUS AND SHARPER RIDGING EXTENDING FROM MEXICO AND THE GULF OF MEXICO NORTH INTO THE WESTERN GREAT LAKES AND MS VALLEY. WITH THE PATTERN SET TO AMPLIFY...THE CURRENT STATIONARY FRONT WILL GRADUALLY LIFT NORTHEAST...BUT MAY BE NEAR THE OH RIVER AND BIG SANDY RIVER VALLEYS AT THE END OF THE PERIOD. HOWEVER...MORE SATURATION OR DEEPER MOISTURE IS EXPECTED TO CONTINUE TO RESIDE WELL TO THE NORTH OF THE BOUNDARY WHICH SHOULD GRADUALLY LEAD TO CONVECTION THAT DEVELOPS AS DISTURBANCES WORK AROUND THE RIDGE BEING DISPLACED FURTHER NORTH AND EAST AWAY FROM THE JKL CWA. HOWEVER...UNTIL THEN...THE CONVECTION PASSING THROUGH THE CINCINNATI METRO AREA WOULD HAVE A CHANCE TO BRUSH THE FAR NORTH AND EASTERN PARTS OF THE CWA TOWARD DAWN INTO THE EARLY MORNING HOURS...IF IT HOLDS TOGETHER. CONFIDENCE IN THIS IS NOT ALL THAT HIGH...THUS JUST SLIGHT POPS. THE REST OF THE CONVECTION SEEMS TO BE HANDLED WELL BY THE LAST COUPLE OF HRRR RUNS...WHICH KEEP IT A LITTLE NORTH AND EAST OF THE CWA THROUGH MID AFTERNOON ON MONDAY. WITH THIS IN MIND...SLIGHT CHANCE POPS WERE USED THIS MORNING FROM FLEMING COUNTY SOUTHEAST TO ELLIOTT...MARTIN AND EASTERN PARTS OF PIKE COUNTY. THE OTHER CONCERN FOR TODAY IS FIRE WEATHER AS RELATIVELY CLOUD FREE SKIES WILL LEAD TO PLENTY OF SUNSHINE AND RATHER DEEP MIXING. THIS SHOULD ALLOW HIGHER MOMENTUM FROM ALOFT TO MIX DOWN FOR SOME 10 TO 15 MPH SUSTAINED WINDS AT TIMES ACROSS THE SOUTHWEST HALF OR SO OF THE CWA DURING THE AFTERNOON INTO THE EVENING. IN ADDITION...DEWPOINTS WILL LIKELY BE A BIT LOWER TODAY THAN ADVERTISED AS HAS BEEN THE TREND THE PAST COUPLE OF DAYS. THIS IS LIKELY DUE TO OUR STATE OF GREENNESS STILL LAGGING A BIT BEHIND AVERAGE AND THE POTENTIAL TO MIX DOWN SOME DRIER AIR FROM ALOFT. RH SHOULD FALL BELOW 30 PERCENT ACROSS SOUTHERN PARTS OF THE CWA THIS AFTERNOON AND MAY DROP TO 25 PERCENT IN A FEW SPOTS. AS FOR MAX TEMPS...STAYED WITH PERSISTENCE OF THE PREVIOUS FORECAST OF MAX T ABOVE GUIDANCE WHICH IS IN LINE WITH OUR SLIGHTLY BEHIND AVERAGE GREENNESS. TONIGHT...DESPITE THE BOUNDARY EXPECTED TO STILL BISECT THE CWA...THERE WILL EITHER BE CONSIDERABLE BREAKS IN CLOUD COVER FROM TO TIME IF NOT MOSTLY CLEAR TO CLEAR SKIES IN MORE SOUTHERN LOCATIONS AND ANOTHER RIDGE/VALLEY SPLIT IS ANTICIPATED. CLOUDS MAY LIMIT MAX T A BIT FROM THEIR POTENTIAL ON TUESDAY...HOWEVER... AT THIS POINT EXPECT TEMPERATURES SHOULD REMAIN MILD. DRY WEATHER IS ALSO EXPECTED AS RIDGING AND HEIGHT RISES WORK INTO THE REGION. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 300 AM EDT MON MAY 5 2014 HIGH PRESSURE WILL PROVIDE WARM AND DRY WEATHER FOR OUR REGION THROUGH THE MIDDLE OF THE WEEK. BOTH WEDNESDAY AND THURSDAY WILL FEATURE PLENTY OF SUNSHINE ALONG WITH BREEZY SOUTHWEST WINDS AND HIGHS IN THE MID TO UPPER 80S. WHILE GREENUP IS PROGRESSING NICELY...THE COMBINATION OF GUSTY WINDS AND LOW AFTERNOON HUMIDITY MAY LEAD TO SOME FIRE WEATHER CONCERNS BOTH WEDNESDAY AND THURSDAY AFTERNOON. A SERIES OF SHORTWAVES WILL THEN EJECT EASTWARD FROM THEIR PARENT LONGWAVE TROUGH OVER THE ROCKIES. THIS WILL RESULT IN THE RIDGE GETTING SHOVED TO OUR EAST AS THE WORK WEEK ENDS. AT THE SURFACE...A COLD FRONT WILL SLIDE EASTWARD INTO OUR AREA BY FRIDAY BRINGING INCREASING RAIN CHANCES. THE FRONT IS STILL PROGGED TO HANG UP OVER US OR VERY CLOSE BY...AND BE A FOCUS FOR ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH THE WEEKEND. WILL CONTINUE TO INDICATE GREATEST RAIN CHANCES FRIDAY NIGHT INTO SATURDAY AS MODELS DIVERGE A BIT ON THE TIMING/LOCATION OF ADDITIONAL SHORTWAVE ENERGY LATE IN THE WEEKEND AND WHETHER OR NOT THIS WILL SEND ANOTHER SURGE OF PRECIPITATION INTO OUR AREA SATURDAY NIGHT AND SUNDAY. EITHER WAY...PROGS INDICATE THE POTENTIAL FOR ANOTHER INCH OR TWO OF RAINFALL OVER THE WEEKEND. THE INCREASE IN CLOUDS AND PRECIPITATION WILL DROP HIGHS FROM AROUND 80 ON FRIDAY INTO THE 70S SATURDAY AND SUNDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 202 PM EDT MON MAY 5 2014 VFR CONDITIONS WILL CONTINUE OVER THE NEXT 24 TO 36 HOURS DESPITE THE PRESENCE OF A STATIONARY BOUNDARY LYING ACROSS THE NORTHERN PORTION OF THE AREA. MOISTURE IS LIMITED ALONG THIS BOUNDARY AND SHOULD NOT YIELD ANYTHING MORE THAN A FEW MID LEVEL CLOUDS. GUSTY SOUTHWEST WINDS WILL SUBSIDE AROUND SUNSET THIS EVENING...THEN REDEVELOP...BUT NOT QUITE AS STRONG TUESDAY MORNING AFTER SUNRISE. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...JP LONG TERM...ABE AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
922 AM EDT MON MAY 5 2014 .UPDATE... ISSUED AT 922 AM EDT MON MAY 5 2014 A WARM AND DRY DAY IS ON TAP ACROSS THE COAL FIELDS. TEMPERATURES ARE ALREADY ABOUT 5 TO 6 DEGREES AHEAD OF YESTERDAYS DIURNAL CURVE...SO GOING TO UP TEMPERATURES MORE SOLIDLY INTO THE MID 80S. A FEW 87 OR 88 DEGREE READINGS CANNOT BE RULED OUT GIVEN THE DRY SURFACE CONDITIONS IN PLACE ACROSS SOUTHEAST KENTUCKY. GIVEN THE WARMER TEMPS AND DRY SFC CONDITIONS...HAVE ISSUED AN SPS FOR AN ELEVATED FIRE DANGER THIS AFTERNOON AND HIGHLIGHTED IN THE HWO. ALSO...SCALED BACK THE SKY COVER WITH ONLY A VERY SCATTERED MID LEVEL DECK ARRIVING FROM THE NORTHWEST THROUGH THE AFTERNOON. OVERALL...WE SHOULD AVERAGE OUT TO A MOSTLY SUNNY SKY THROUGH THE DAY. UPDATE ISSUED AT 740 AM EDT MON MAY 5 2014 HOURLY GRIDS WERE UPDATED BASED ON RECENT SATELLITE...RADAR AND OBSERVATION TRENDS. CONVECTION SO FAR REMAINS NORTH AND EAST OF THE CWA...BUT RECENT NEAR TERM GUIDANCE SUGGESTS THAT A SHOWER OR TWO IS POSSIBLE ACROSS THE NORTHERN AND EASTERN FRINGES OF THE CWA THROUGH MIDDAY. CONFIDENCE IN THIS IS LOW...SO WE HAVE CONTINUED WITH SLIGHT CHANCE POPS IN THIS AREA. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 345 AM EDT MON MAY 5 2014 EARLY THIS MORNING...A NEARLY STATIONARY BOUNDARY EXTENDED EAST INTO THE COMMONWEALTH FROM LOW PRESSURE OVER THE CENTRAL PLAINS STATES. THIS BOUNDARY SEPARATED A MUCH DRIER AIRMASS ACROSS THE NORTHERN TWO THIRDS OF THE CWA FROM A SLIGHTLY MORE MOIST AIRMASS ACROSS THE SOUTHERN THIRD OF THE CWA. SFC DEWPOINTS CURRENTLY OVER NORTHEAST KY ARE IN THE LOWER 30S WITH DEWPOINTS IN THE LOWER 50S ALONG THE TN BORDER. A WEAK SHORTWAVE WORKING AROUND MID LEVEL RIDGING CENTERED OVER MEXICO AND EXTENDING NORTH INTO THE PLAINS AND LOWER MS VALLEY WAS INTERACTING WITH THE BAROCLINIC ZONE AND A LOW LEVEL JET OVER THE LOWER OH VALLEY REGION TO PRODUCE CONVECTION FROM NORTHEASTERN IL SOUTHEAST INTO CENTRAL WV. OTHER CONVECTION WAS A BIT FURTHER SOUTHWEST OF THIS ACTIVITY AND EARLIER PASSED NEAR KIND AND WAS PASSING NEAR THE KCVG VICINITY. THROUGH THE PERIOD...SOME AMPLIFICATION IS EXPECTED TO THE PATTERN WITH TROUGHING GRADUALLY DEPARTING THE NORTHEASTERN CONUS AND TROUGHING DIGGING SOUTH INTO THE DESERT SOUTHWEST LEADING TO A WESTERN CONUS AND SHARPER RIDGING EXTENDING FROM MEXICO AND THE GULF OF MEXICO NORTH INTO THE WESTERN GREAT LAKES AND MS VALLEY. WITH THE PATTERN SET TO AMPLIFY...THE CURRENT STATIONARY FRONT WILL GRADUALLY LIFT NORTHEAST...BUT MAY BE NEAR THE OH RIVER AND BIG SANDY RIVER VALLEYS AT THE END OF THE PERIOD. HOWEVER...MORE SATURATION OR DEEPER MOISTURE IS EXPECTED TO CONTINUE TO RESIDE WELL TO THE NORTH OF THE BOUNDARY WHICH SHOULD GRADUALLY LEAD TO CONVECTION THAT DEVELOPS AS DISTURBANCES WORK AROUND THE RIDGE BEING DISPLACED FURTHER NORTH AND EAST AWAY FROM THE JKL CWA. HOWEVER...UNTIL THEN...THE CONVECTION PASSING THROUGH THE CINCINNATI METRO AREA WOULD HAVE A CHANCE TO BRUSH THE FAR NORTH AND EASTERN PARTS OF THE CWA TOWARD DAWN INTO THE EARLY MORNING HOURS...IF IT HOLDS TOGETHER. CONFIDENCE IN THIS IS NOT ALL THAT HIGH...THUS JUST SLIGHT POPS. THE REST OF THE CONVECTION SEEMS TO BE HANDLED WELL BY THE LAST COUPLE OF HRRR RUNS...WHICH KEEP IT A LITTLE NORTH AND EAST OF THE CWA THROUGH MID AFTERNOON ON MONDAY. WITH THIS IN MIND...SLIGHT CHANCE POPS WERE USED THIS MORNING FROM FLEMING COUNTY SOUTHEAST TO ELLIOTT...MARTIN AND EASTERN PARTS OF PIKE COUNTY. THE OTHER CONCERN FOR TODAY IS FIRE WEATHER AS RELATIVELY CLOUD FREE SKIES WILL LEAD TO PLENTY OF SUNSHINE AND RATHER DEEP MIXING. THIS SHOULD ALLOW HIGHER MOMENTUM FROM ALOFT TO MIX DOWN FOR SOME 10 TO 15 MPH SUSTAINED WINDS AT TIMES ACROSS THE SOUTHWEST HALF OR SO OF THE CWA DURING THE AFTERNOON INTO THE EVENING. IN ADDITION...DEWPOINTS WILL LIKELY BE A BIT LOWER TODAY THAN ADVERTISED AS HAS BEEN THE TREND THE PAST COUPLE OF DAYS. THIS IS LIKELY DUE TO OUR STATE OF GREENNESS STILL LAGGING A BIT BEHIND AVERAGE AND THE POTENTIAL TO MIX DOWN SOME DRIER AIR FROM ALOFT. RH SHOULD FALL BELOW 30 PERCENT ACROSS SOUTHERN PARTS OF THE CWA THIS AFTERNOON AND MAY DROP TO 25 PERCENT IN A FEW SPOTS. AS FOR MAX TEMPS...STAYED WITH PERSISTENCE OF THE PREVIOUS FORECAST OF MAX T ABOVE GUIDANCE WHICH IS IN LINE WITH OUR SLIGHTLY BEHIND AVERAGE GREENNESS. TONIGHT...DESPITE THE BOUNDARY EXPECTED TO STILL BISECT THE CWA...THERE WILL EITHER BE CONSIDERABLE BREAKS IN CLOUD COVER FROM TO TIME IF NOT MOSTLY CLEAR TO CLEAR SKIES IN MORE SOUTHERN LOCATIONS AND ANOTHER RIDGE/VALLEY SPLIT IS ANTICIPATED. CLOUDS MAY LIMIT MAX T A BIT FROM THEIR POTENTIAL ON TUESDAY...HOWEVER... AT THIS POINT EXPECT TEMPERATURES SHOULD REMAIN MILD. DRY WEATHER IS ALSO EXPECTED AS RIDGING AND HEIGHT RISES WORK INTO THE REGION. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 300 AM EDT MON MAY 5 2014 HIGH PRESSURE WILL PROVIDE WARM AND DRY WEATHER FOR OUR REGION THROUGH THE MIDDLE OF THE WEEK. BOTH WEDNESDAY AND THURSDAY WILL FEATURE PLENTY OF SUNSHINE ALONG WITH BREEZY SOUTHWEST WINDS AND HIGHS IN THE MID TO UPPER 80S. WHILE GREENUP IS PROGRESSING NICELY...THE COMBINATION OF GUSTY WINDS AND LOW AFTERNOON HUMIDITY MAY LEAD TO SOME FIRE WEATHER CONCERNS BOTH WEDNESDAY AND THURSDAY AFTERNOON. A SERIES OF SHORTWAVES WILL THEN EJECT EASTWARD FROM THEIR PARENT LONGWAVE TROUGH OVER THE ROCKIES. THIS WILL RESULT IN THE RIDGE GETTING SHOVED TO OUR EAST AS THE WORK WEEK ENDS. AT THE SURFACE...A COLD FRONT WILL SLIDE EASTWARD INTO OUR AREA BY FRIDAY BRINGING INCREASING RAIN CHANCES. THE FRONT IS STILL PROGGED TO HANG UP OVER US OR VERY CLOSE BY...AND BE A FOCUS FOR ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH THE WEEKEND. WILL CONTINUE TO INDICATE GREATEST RAIN CHANCES FRIDAY NIGHT INTO SATURDAY AS MODELS DIVERGE A BIT ON THE TIMING/LOCATION OF ADDITIONAL SHORTWAVE ENERGY LATE IN THE WEEKEND AND WHETHER OR NOT THIS WILL SEND ANOTHER SURGE OF PRECIPITATION INTO OUR AREA SATURDAY NIGHT AND SUNDAY. EITHER WAY...PROGS INDICATE THE POTENTIAL FOR ANOTHER INCH OR TWO OF RAINFALL OVER THE WEEKEND. THE INCREASE IN CLOUDS AND PRECIPITATION WILL DROP HIGHS FROM AROUND 80 ON FRIDAY INTO THE 70S SATURDAY AND SUNDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 745 AM EDT MON MAY 5 2014 VFR CONDITIONS WILL PREVAIL OVER THE NEXT 24 HOURS ON AVERAGE. WE CAN EXPECT SCATTERED TO AT TIMES BROKEN MIDDLE AND HIGH LEVEL CLOUD COVER AT TIMES..ESPECIALLY AT JKL AND SJS. STRAY CONVECTION WITH BRIEF MVFR COULD PASS NEAR SJS 14Z TO 19Z...BUT NEARLY ALL LOCATIONS WILL REMAIN DRY. WINDS WILL BECOME A BIT GUSTY...AND SUSTAINED AROUND 12KT ESPECIALLY AT SME AND LOZ BETWEEN 14Z AND 00Z. OTHERWISE...WINDS WILL BE LIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...JP LONG TERM...ABE AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
748 AM EDT MON MAY 5 2014 .UPDATE... ISSUED AT 740 AM EDT MON MAY 5 2014 HOURLY GRIDS WERE UPDATED BASED ON RECENT SATELLITE...RADAR AND OBSERVATION TRENDS. CONVECTION SO FAR REMAINS NORTH AND EAST OF THE CWA...BUT RECENT NEAR TERM GUIDANCE SUGGESTS THAT A SHOWER OR TWO IS POSSIBLE ACROSS THE NORTHERN AND EASTERN FRINGES OF THE CWA THROUGH MIDDAY. CONFIDENCE IN THIS IS LOW...SO WE HAVE CONTINUED WITH SLIGHT CHANCE POPS IN THIS AREA. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 345 AM EDT MON MAY 5 2014 EARLY THIS MORNING...A NEARLY STATIONARY BOUNDARY EXTENDED EAST INTO THE COMMONWEALTH FROM LOW PRESSURE OVER THE CENTRAL PLAINS STATES. THIS BOUNDARY SEPARATED A MUCH DRIER AIRMASS ACROSS THE NORTHERN TWO THIRDS OF THE CWA FROM A SLIGHTLY MORE MOIST AIRMASS ACROSS THE SOUTHERN THIRD OF THE CWA. SFC DEWPOINTS CURRENTLY OVER NORTHEAST KY ARE IN THE LOWER 30S WITH DEWPOINTS IN THE LOWER 50S ALONG THE TN BORDER. A WEAK SHORTWAVE WORKING AROUND MID LEVEL RIDGING CENTERED OVER MEXICO AND EXTENDING NORTH INTO THE PLAINS AND LOWER MS VALLEY WAS INTERACTING WITH THE BAROCLINIC ZONE AND A LOW LEVEL JET OVER THE LOWER OH VALLEY REGION TO PRODUCE CONVECTION FROM NORTHEASTERN IL SOUTHEAST INTO CENTRAL WV. OTHER CONVECTION WAS A BIT FURTHER SOUTHWEST OF THIS ACTIVITY AND EARLIER PASSED NEAR KIND AND WAS PASSING NEAR THE KCVG VICINITY. THROUGH THE PERIOD...SOME AMPLIFICATION IS EXPECTED TO THE PATTERN WITH TROUGHING GRADUALLY DEPARTING THE NORTHEASTERN CONUS AND TROUGHING DIGGING SOUTH INTO THE DESERT SOUTHWEST LEADING TO A WESTERN CONUS AND SHARPER RIDGING EXTENDING FROM MEXICO AND THE GULF OF MEXICO NORTH INTO THE WESTERN GREAT LAKES AND MS VALLEY. WITH THE PATTERN SET TO AMPLIFY...THE CURRENT STATIONARY FRONT WILL GRADUALLY LIFT NORTHEAST...BUT MAY BE NEAR THE OH RIVER AND BIG SANDY RIVER VALLEYS AT THE END OF THE PERIOD. HOWEVER...MORE SATURATION OR DEEPER MOISTURE IS EXPECTED TO CONTINUE TO RESIDE WELL TO THE NORTH OF THE BOUNDARY WHICH SHOULD GRADUALLY LEAD TO CONVECTION THAT DEVELOPS AS DISTURBANCES WORK AROUND THE RIDGE BEING DISPLACED FURTHER NORTH AND EAST AWAY FROM THE JKL CWA. HOWEVER...UNTIL THEN...THE CONVECTION PASSING THROUGH THE CINCINNATI METRO AREA WOULD HAVE A CHANCE TO BRUSH THE FAR NORTH AND EASTERN PARTS OF THE CWA TOWARD DAWN INTO THE EARLY MORNING HOURS...IF IT HOLDS TOGETHER. CONFIDENCE IN THIS IS NOT ALL THAT HIGH...THUS JUST SLIGHT POPS. THE REST OF THE CONVECTION SEEMS TO BE HANDLED WELL BY THE LAST COUPLE OF HRRR RUNS...WHICH KEEP IT A LITTLE NORTH AND EAST OF THE CWA THROUGH MID AFTERNOON ON MONDAY. WITH THIS IN MIND...SLIGHT CHANCE POPS WERE USED THIS MORNING FROM FLEMING COUNTY SOUTHEAST TO ELLIOTT...MARTIN AND EASTERN PARTS OF PIKE COUNTY. THE OTHER CONCERN FOR TODAY IS FIRE WEATHER AS RELATIVELY CLOUD FREE SKIES WILL LEAD TO PLENTY OF SUNSHINE AND RATHER DEEP MIXING. THIS SHOULD ALLOW HIGHER MOMENTUM FROM ALOFT TO MIX DOWN FOR SOME 10 TO 15 MPH SUSTAINED WINDS AT TIMES ACROSS THE SOUTHWEST HALF OR SO OF THE CWA DURING THE AFTERNOON INTO THE EVENING. IN ADDITION...DEWPOINTS WILL LIKELY BE A BIT LOWER TODAY THAN ADVERTISED AS HAS BEEN THE TREND THE PAST COUPLE OF DAYS. THIS IS LIKELY DUE TO OUR STATE OF GREENNESS STILL LAGGING A BIT BEHIND AVERAGE AND THE POTENTIAL TO MIX DOWN SOME DRIER AIR FROM ALOFT. RH SHOULD FALL BELOW 30 PERCENT ACROSS SOUTHERN PARTS OF THE CWA THIS AFTERNOON AND MAY DROP TO 25 PERCENT IN A FEW SPOTS. AS FOR MAX TEMPS...STAYED WITH PERSISTENCE OF THE PREVIOUS FORECAST OF MAX T ABOVE GUIDANCE WHICH IS IN LINE WITH OUR SLIGHTLY BEHIND AVERAGE GREENNESS. TONIGHT...DESPITE THE BOUNDARY EXPECTED TO STILL BISECT THE CWA...THERE WILL EITHER BE CONSIDERABLE BREAKS IN CLOUD COVER FROM TO TIME IF NOT MOSTLY CLEAR TO CLEAR SKIES IN MORE SOUTHERN LOCATIONS AND ANOTHER RIDGE/VALLEY SPLIT IS ANTICIPATED. CLOUDS MAY LIMIT MAX T A BIT FROM THEIR POTENTIAL ON TUESDAY...HOWEVER... AT THIS POINT EXPECT TEMPERATURES SHOULD REMAIN MILD. DRY WEATHER IS ALSO EXPECTED AS RIDGING AND HEIGHT RISES WORK INTO THE REGION. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 300 AM EDT MON MAY 5 2014 HIGH PRESSURE WILL PROVIDE WARM AND DRY WEATHER FOR OUR REGION THROUGH THE MIDDLE OF THE WEEK. BOTH WEDNESDAY AND THURSDAY WILL FEATURE PLENTY OF SUNSHINE ALONG WITH BREEZY SOUTHWEST WINDS AND HIGHS IN THE MID TO UPPER 80S. WHILE GREENUP IS PROGRESSING NICELY...THE COMBINATION OF GUSTY WINDS AND LOW AFTERNOON HUMIDITY MAY LEAD TO SOME FIRE WEATHER CONCERNS BOTH WEDNESDAY AND THURSDAY AFTERNOON. A SERIES OF SHORTWAVES WILL THEN EJECT EASTWARD FROM THEIR PARENT LONGWAVE TROUGH OVER THE ROCKIES. THIS WILL RESULT IN THE RIDGE GETTING SHOVED TO OUR EAST AS THE WORK WEEK ENDS. AT THE SURFACE...A COLD FRONT WILL SLIDE EASTWARD INTO OUR AREA BY FRIDAY BRINGING INCREASING RAIN CHANCES. THE FRONT IS STILL PROGGED TO HANG UP OVER US OR VERY CLOSE BY...AND BE A FOCUS FOR ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH THE WEEKEND. WILL CONTINUE TO INDICATE GREATEST RAIN CHANCES FRIDAY NIGHT INTO SATURDAY AS MODELS DIVERGE A BIT ON THE TIMING/LOCATION OF ADDITIONAL SHORTWAVE ENERGY LATE IN THE WEEKEND AND WHETHER OR NOT THIS WILL SEND ANOTHER SURGE OF PRECIPITATION INTO OUR AREA SATURDAY NIGHT AND SUNDAY. EITHER WAY...PROGS INDICATE THE POTENTIAL FOR ANOTHER INCH OR TWO OF RAINFALL OVER THE WEEKEND. THE INCREASE IN CLOUDS AND PRECIPITATION WILL DROP HIGHS FROM AROUND 80 ON FRIDAY INTO THE 70S SATURDAY AND SUNDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 745 AM EDT MON MAY 5 2014 VFR CONDITIONS WILL PREVAIL OVER THE NEXT 24 HOURS ON AVERAGE. WE CAN EXPECT SCATTERED TO AT TIMES BROKEN MIDDLE AND HIGH LEVEL CLOUD COVER AT TIMES..ESPECIALLY AT JKL AND SJS. STRAY CONVECTION WITH BRIEF MVFR COULD PASS NEAR SJS 14Z TO 19Z...BUT NEARLY ALL LOCATIONS WILL REMAIN DRY. WINDS WILL BECOME A BIT GUSTY...AND SUSTAINED AROUND 12KT ESPECIALLY AT SME AND LOZ BETWEEN 14Z AND 00Z. OTHERWISE...WINDS WILL BE LIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...JP LONG TERM...ABE AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
418 AM EDT MON MAY 5 2014 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 345 AM EDT MON MAY 5 2014 EARLY THIS MORNING...A NEARLY STATIONARY BOUNDARY EXTENDED EAST INTO THE COMMONWEALTH FROM LOW PRESSURE OVER THE CENTRAL PLAINS STATES. THIS BOUNDARY SEPARATED A MUCH DRIER AIRMASS ACROSS THE NORTHERN TWO THIRDS OF THE CWA FROM A SLIGHTLY MORE MOIST AIRMASS ACROSS THE SOUTHERN THIRD OF THE CWA. SFC DEWPOINTS CURRENTLY OVER NORTHEAST KY ARE IN THE LOWER 30S WITH DEWPOINTS IN THE LOWER 50S ALONG THE TN BORDER. A WEAK SHORTWAVE WORKING AROUND MID LEVEL RIDGING CENTERED OVER MEXICO AND EXTENDING NORTH INTO THE PLAINS AND LOWER MS VALLEY WAS INTERACTING WITH THE BAROCLINIC ZONE AND A LOW LEVEL JET OVER THE LOWER OH VALLEY REGION TO PRODUCE CONVECTION FROM NORTHEASTERN IL SOUTHEAST INTO CENTRAL WV. OTHER CONVECTION WAS A BIT FURTHER SOUTHWEST OF THIS ACTIVITY AND EARLIER PASSED NEAR KIND AND WAS PASSING NEAR THE KCVG VICINITY. THROUGH THE PERIOD...SOME AMPLIFICATION IS EXPECTED TO THE PATTERN WITH TROUGHING GRADUALLY DEPARTING THE NORTHEASTERN CONUS AND TROUGHING DIGGING SOUTH INTO THE DESERT SOUTHWEST LEADING TO A WESTERN CONUS AND SHARPER RIDGING EXTENDING FROM MEXICO AND THE GULF OF MEXICO NORTH INTO THE WESTERN GREAT LAKES AND MS VALLEY. WITH THE PATTERN SET TO AMPLIFY...THE CURRENT STATIONARY FRONT WILL GRADUALLY LIFT NORTHEAST...BUT MAY BE NEAR THE OH RIVER AND BIG SANDY RIVER VALLEYS AT THE END OF THE PERIOD. HOWEVER...MORE SATURATION OR DEEPER MOISTURE IS EXPECTED TO CONTINUE TO RESIDE WELL TO THE NORTH OF THE BOUNDARY WHICH SHOULD GRADUALLY LEAD TO CONVECTION THAT DEVELOPS AS DISTURBANCES WORK AROUND THE RIDGE BEING DISPLACED FURTHER NORTH AND EAST AWAY FROM THE JKL CWA. HOWEVER...UNTIL THEN...THE CONVECTION PASSING THROUGH THE CINCINNATI METRO AREA WOULD HAVE A CHANCE TO BRUSH THE FAR NORTH AND EASTERN PARTS OF THE CWA TOWARD DAWN INTO THE EARLY MORNING HOURS...IF IT HOLDS TOGETHER. CONFIDENCE IN THIS IS NOT ALL THAT HIGH...THUS JUST SLIGHT POPS. THE REST OF THE CONVECTION SEEMS TO BE HANDLED WELL BY THE LAST COUPLE OF HRRR RUNS...WHICH KEEP IT A LITTLE NORTH AND EAST OF THE CWA THROUGH MID AFTERNOON ON MONDAY. WITH THIS IN MIND...SLIGHT CHANCE POPS WERE USED THIS MORNING FROM FLEMING COUNTY SOUTHEAST TO ELLIOTT...MARTIN AND EASTERN PARTS OF PIKE COUNTY. THE OTHER CONCERN FOR TODAY IS FIRE WEATHER AS RELATIVELY CLOUD FREE SKIES WILL LEAD TO PLENTY OF SUNSHINE AND RATHER DEEP MIXING. THIS SHOULD ALLOW HIGHER MOMENTUM FROM ALOFT TO MIX DOWN FOR SOME 10 TO 15 MPH SUSTAINED WINDS AT TIMES ACROSS THE SOUTHWEST HALF OR SO OF THE CWA DURING THE AFTERNOON INTO THE EVENING. IN ADDITION...DEWPOINTS WILL LIKELY BE A BIT LOWER TODAY THAN ADVERTISED AS HAS BEEN THE TREND THE PAST COUPLE OF DAYS. THIS IS LIKELY DUE TO OUR STATE OF GREENNESS STILL LAGGING A BIT BEHIND AVERAGE AND THE POTENTIAL TO MIX DOWN SOME DRIER AIR FROM ALOFT. RH SHOULD FALL BELOW 30 PERCENT ACROSS SOUTHERN PARTS OF THE CWA THIS AFTERNOON AND MAY DROP TO 25 PERCENT IN A FEW SPOTS. AS FOR MAX TEMPS...STAYED WITH PERSISTENCE OF THE PREVIOUS FORECAST OF MAX T ABOVE GUIDANCE WHICH IS IN LINE WITH OUR SLIGHTLY BEHIND AVERAGE GREENNESS. TONIGHT...DESPITE THE BOUNDARY EXPECTED TO STILL BISECT THE CWA...THERE WILL EITHER BE CONSIDERABLE BREAKS IN CLOUD COVER FROM TO TIME IF NOT MOSTLY CLEAR TO CLEAR SKIES IN MORE SOUTHERN LOCATIONS AND ANOTHER RIDGE/VALLEY SPLIT IS ANTICIPATED. CLOUDS MAY LIMIT MAX T A BIT FROM THEIR POTENTIAL ON TUESDAY...HOWEVER... AT THIS POINT EXPECT TEMPERATURES SHOULD REMAIN MILD. DRY WEATHER IS ALSO EXPECTED AS RIDGING AND HEIGHT RISES WORK INTO THE REGION. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 300 AM EDT MON MAY 5 2014 HIGH PRESSURE WILL PROVIDE WARM AND DRY WEATHER FOR OUR REGION THROUGH THE MIDDLE OF THE WEEK. BOTH WEDNESDAY AND THURSDAY WILL FEATURE PLENTY OF SUNSHINE ALONG WITH BREEZY SOUTHWEST WINDS AND HIGHS IN THE MID TO UPPER 80S. WHILE GREENUP IS PROGRESSING NICELY...THE COMBINATION OF GUSTY WINDS AND LOW AFTERNOON HUMIDITY MAY LEAD TO SOME FIRE WEATHER CONCERNS BOTH WEDNESDAY AND THURSDAY AFTERNOON. A SERIES OF SHORTWAVES WILL THEN EJECT EASTWARD FROM THEIR PARENT LONGWAVE TROUGH OVER THE ROCKIES. THIS WILL RESULT IN THE RIDGE GETTING SHOVED TO OUR EAST AS THE WORK WEEK ENDS. AT THE SURFACE...A COLD FRONT WILL SLIDE EASTWARD INTO OUR AREA BY FRIDAY BRINGING INCREASING RAIN CHANCES. THE FRONT IS STILL PROGGED TO HANG UP OVER US OR VERY CLOSE BY...AND BE A FOCUS FOR ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH THE WEEKEND. WILL CONTINUE TO INDICATE GREATEST RAIN CHANCES FRIDAY NIGHT INTO SATURDAY AS MODELS DIVERGE A BIT ON THE TIMING/LOCATION OF ADDITIONAL SHORTWAVE ENERGY LATE IN THE WEEKEND AND WHETHER OR NOT THIS WILL SEND ANOTHER SURGE OF PRECIPITATION INTO OUR AREA SATURDAY NIGHT AND SUNDAY. EITHER WAY...PROGS INDICATE THE POTENTIAL FOR ANOTHER INCH OR TWO OF RAINFALL OVER THE WEEKEND. THE INCREASE IN CLOUDS AND PRECIPITATION WILL DROP HIGHS FROM AROUND 80 ON FRIDAY INTO THE 70S SATURDAY AND SUNDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 150 AM EDT MON MAY 5 2014 VFR CONDITIONS WILL CONTINUE OVER THE NEXT 24 HOURS ON AVERAGE. WE CAN EXPECT SCATTERED TO AT TIMES BROKEN MIDDLE AND HIGH LEVEL CLOUD COVER AT ALL FOUR TAF STIES. LIGHT WINDS AND MOSTLY CLEAR SKIES COULD ALLOW FOR SOME FOG FORMATION OVERNIGHT...IN OUR DEEPEST RIVER VALLEYS. THE FOG WILL BECOME WIDESPREAD ENOUGH TO AFFECT ANY OF THE TAF SITES. STRAY CONVECTION WITH BRIEF MVFR COULD PASS NEAR KSJS 16Z TO 22Z. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JP LONG TERM...ABE AVIATION...JP
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
210 AM EDT MON MAY 5 2014 .SYNOPSIS... A COLD FRONT PUSHES SOUTH OF THE REGION OVERNIGHT...THEN STALLS OVER THE CAROLINAS ON MONDAY. THE FRONT STARTS TO MOVE BACK NORTH AS A WARM FRONT TUESDAY THROUGH WEDNESDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... CDFNT CURRENTLY MAKING PROGRESS SSW THROUGH INTERIOR E AND SE VA...AND WILL CONT TO SETTLE S THROUGH THE FCST NEXT FEW HRS. 00Z/05 RUC PUSHES THE FNT S INTO SRN NC BY 12Z/05. BECOMING COOLER POST CDFNT OVRNGT...W/ LO TEMPS RANGING FM M/U40S N...TO THE L/M50S S. VRB CLDS/PCLDY ACRS THE FA THE REST OF THE NGT...W/ POPS AOB 14%. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/... MID/UPPER LEVEL FLOW TURNS NW ON MONDAY AS THE FRONT STALLS OVER NC. LATEST GFS/NAM/ECMWF REMAIN IN GOOD AGREEMENT IN BRINGING INCREASING OVERRUNNING MOISTURE IN FROM THE WEST MON AFTN/MON NIGHT. AFTER SOME MORNING SUNSHINE...EXPECT SKIES TO CLOUD OVER FROM W TO E BY LATE MORNING INTO THE AFTN. WILL CARRY CHC POPS IN THE AFTN FOR MUCH OF THE AREA (HIGHEST W/NW). TEMPERATURES WILL BE QUITE A BIT COOLER WITH HIGHS ONLY IN THE MID 60S TO LOWER 70S DEPENDING ON THE AMOUNT OF SUNSHINE. BY LATE MON AFTN AND ESPECIALLY IN THE EVENING IS WHEN MID LEVEL (H7 TO H5) LAPSE RATES INCREASE TO 7-7.5 C IN SW 1/2 OF THE CWA. SHOWALTER INDICES ALSO GO NEGATIVE IN THESE AREAS DESPITE COOL BOUNDARY LAYER (AND +LI VALUES). THUS...WILL MAINTAIN ISOLATED TO WIDELY SCATTERED TSTMS (MAINLY ELEVATED) ALONG/SOUTH OF I-64. WEAK HIGH PRESSURE LOOKS TO PUSH A LITTLE TO THE SOUTH OFF THE COAST ON TUE...AND WILL LIKELY LIMIT POPS FOR TUE EXCEPT ACRS THE SW WHERE A 20% POP WILL BE MAINTAINED. LOW LEVEL LIGHT/E/NE FLOW WILL KEEP TEMPS FAIRLY COOL AGAIN...65-70F NEAR THE COAST AND LOW 70S WELL INLAND. THE FRONT OVER THE CAROLINAS WILL BEGIN TO LIFT BACK NORTH TUESDAY NIGHT/WED...AND MAY PROVIDE SOME FOCUS FOR SHWR AND ISOLD TSTSM CHANCES WED (ALTHOUGH BEST FORCING LOOKS TO BE W OF THE AKQ CWA). SLIGHTLY WARMER WITH HIGHS MAINLY IN THE 70S UNDER PARTLY/MOSTLY CLOUDY SKIES. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE EXTENDED FCST WILL BE HIGHLIGHTED BY ABOVE NORMAL TEMPS ACRS THE REGION. A WARM FRONT WILL LIFT THRU CNTRL AND ERN CNTIES WED NGT THRU THU...POSSIBLY PRODUCING A FEW SHOWERS. UPR RDG WILL BLD OVR THE AREA FOR THU AFTN THRU FRI...THEN SLIDES OFF THE CST FOR FRI NGT THRU SAT...AS A FRONTAL BOUNDARY APPROACHES AND MOVES IN FM THE W. THAT BOUNDARY WILL PUSH THRU THE REGION LATE SAT THRU SUN. WILL HAVE INCREASING POPS FM NW TO SE FRI NGT THRU SAT...THEN MAINLY HAVE CHC POPS EVERYWHERE SAT NGT THRU SUN...ALNG WITH SLGT CHC/CHC OF THUNDER. MIN TEMPS WILL RANGE THRU THE 50S THU MORNG...UPR 50S TO LWR 60S FRI MORNG...LWR TO MID 60S SAT MORNG...AND 60 TO 65 SUN MORNG. MAX TEMPS WILL RANGE FM THE LWR 70S TO THE MID 80S THU...UPR 70S TO MID 80S FRI...MID 70S TO MID 80S SAT...AND FM THE MID 70S TO ARND 80 SUN. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... A COLD FRONT IS NOW S OF THE REGION. THE WIND SHIFTED TO NE BEHIND THE FRONT AND SHOULD LARGELY BACK TO NORTHERLY THROUGH THIS MORNING ALONG WITH SCT MID CLOUDS ~10K FT. THE BOUNDARY WILL STALL OVER NC...WITH LOW PRESSURE TRACKING ALONG THE FRONT LATER THIS AFTERNOON THROUGH TUESDAY MORNING. CLOUDS SHOULD INCREASE THIS AFTERNOON...WITH CIGS LOWERING TO ~5K FT BY LATE THIS AFTERNOON AND EVENING. THE GREATEST PROBABILITY FOR -SHRA (60%) WILL BE OVER A CORRIDOR THAT INCLUDES RIC/PHF/ORF...WITH ECG/SBY IN A PERIPHERAL ZONE OF 40-50%. AN ISO -TSRA IS POSSIBLE...ESPECIALLY ALONG AND S OF THE VA/NC BORDER. THE FRONT LIFTS BACK N AS A WARM FRONT TUESDAY NIGHT INTO WEDNESDAY...WITH HIGH PRESSURE BECOMING ANCHORED OFF THE SOUTHEAST COAST LATER IN THE WEEK. && .MARINE... CDFNT TO MOVE THROUGH FAR SRN WTRS NEXT COUPLE HRS...ASSOCIATED W/ AN ABRUPT WIND SHIFT TO NNE AND GUSTS TO 25-30 KT. XPCG NNE WNDS ACRS THE WTRS THE REST OF THE NGT. KEEPING SCAS IN PLACE (THE ENTIRE CHES BAY AND THE JAMES RIVER FM THE JAMES RIVER BRIDGE TO THE HAMPTON RDS BRIDGE...AS WELL AS THE TWO NRN CSTL ZNS). ADDITIONALLY...SEAS SHOULD BRIEFLY REACH 4-5 FT FOR THE NRN OCEAN ZONES WITH 3-4 FT WAVES IN THE BAY. THE FRONT STALLS OVER NC EARLY NEXT WEEK...WITH LO PRES TRACKING ALONG THE BOUNDARY MON NGT INTO TUE. A PERIOD OF LIGHT ONSHORE FLOW IS EXPECTED DURING THIS TIMEFRAME. THAT FRONT WILL LIFT BACK NNE ACRS THE WTRS AS A WARM FRONT WED INTO THU. HI PRES EVENTUALLY SETTLES OFF THE MID ATLC/SE CST FOR LATE THU THRU FRI. && .HYDROLOGY... A RIVER FLOOD WARNING REMAINS IN EFFECT FOR THE APPOMATTOX RIVER AT MATTOAX DUE TO RECENT HEAVY RAINFALL. SEE LATEST FLSAKQ PRODUCTS FOR DETAILS. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ632- 634. SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ630- 631-638-650-652. && $$ SYNOPSIS...ALB/LKB NEAR TERM...ALB/LKB SHORT TERM...JDM/LKB LONG TERM...TMG AVIATION...AJZ MARINE...TMG HYDROLOGY...AKQ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
745 PM EDT TUE MAY 6 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 322 PM EDT TUE MAY 6 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW BLDG UPR RDG/SFC HI PRES OVER THE UPR LKS BTWN TROF IN FAR ERN CANADA AND A PAIR OF CLOSED LOWS IN SPLIT FLOW ACRS THE W...ONE OVER ALBERTA AND THE OTHER DIGGING INTO THE DESERT SW. 12Z GRB/APX/MPX RAOBS INDICATE A DRY...STABLE AIRMASS IS IN PLACE...WITH PWAT AS LO AS 0.25 INCH AT APX. BUT THERE ARE PLENTY OF MID/HI CLDS ASSOCIATED WITH WAD/ ISENTROPIC ASCENT IN THE SW FLOW ALF BTWN THE HI OVER THE UPR LKS AND LOWER HGTS/MSLP TO THE W ASSOCIATED WITH THE WRN TROFFING. THERE IS A BAND OF THICKER MID LVL CLDS MOVING ENEWD THRU NE MN/WRN LK SUP AND TOWARD THE WRN LAND CWA ASSOCIATED WITH SHARPER ISENTROPIC ASCENT BEST SHOWN ON THE 300-305K SFCS...OR ABOUT H6-7...WELL TO THE NE OF DVLPG SFC-H85 WARM FNT IN THE CENTRAL PLAINS. BUT ADVECTION OF DRIER AIR IN THE LLVLS WITH STEADY ESE WINDS ON THE WRN FLANK OF THE SFC HI IS PREVENTING ANY PCPN FM REACHING THE GROUND E OF FAR WRN LK SUP. MAIN FCST CONCERN IN THE SHORTER TERM FOCUS ON PCPN CHCS ASSOCIATED WITH LARGER SCALE WAD/ISENTROPIC ASCENT TO THE NE OF WARM FNT NOW IN THE CENTRAL PLAINS. THIS AFTN/TNGT...ALTHOUGH HI CLDS WL SPILL OVER THE ENTIRE CWA THIS AFTN...BAND OF THICKER MID CLDS IS FCST TO IMPACT MAINLY THE NW PORTIONS OF THE CWA THIS AFTN BEFORE SHIFTING TO THE NE AFT SUNSET. THE LLVLS SHOULD REMAIN SUFFICIENTLY DRY TO KEEP PCPN FM REACHING THE SFC EVEN WHERE THE CLDS ARE THICKEST. THE PERIOD FM 00Z-06Z SHOULD BE DRY DESPITE CONSIDERABLE HI CLDS. WITH AN INCRSG H85 SW LLJ/THETA E ADVCTN/DEEP LYR QVECTOR CNVGC TNGT...MORE NMRS SHRA/TS ARE LIKELY TO DVLP AHEAD OF THE WARM FNT MOVING SLOWLY TO THE NE TOWARD SRN MN/WI BY 12Z. BUT SINCE THE SHARPER DEEP LYR QVECTOR CNVGC AND UPR DVGC ARE FCST TO REMAIN S OF UPR MI CLOSER TO THE WARM FNT...CORFIDI VECTORS FCST TO BE WNW IN WI TO THE N OF THE H85 WARM FNT WHICH WOULD RESULT IN MOST NMRS SHRA/TS REMAINING TO THE S AND ROBBING MSTR FOR PCPN FARTHER N...AND DRY AIR IS FCST TO LINGER IN THE SFC-H7 LYR WITHIN PERSISTENT ESE LLVL TRAJECTORIES...SUSPECT THE 12Z GFS IS TOO AGGRESSIVE TO LIFT PCPN INTO MUCH OF UPR MI BY 12Z WED. WL TREND THE FCST CLOSER TO THE DRIER 12Z NAM/REGIONAL CNDN MODELS. THIS GUIDANCE RESTRICTS QPF TO AREAS NEAR THE WI BORDER AND BAND OF SHARPER H85 FGEN. WL FCST HIER CHC POPS OVER SRN MENOMINEE COUNTY BUT GO WITH A DRY FCST FOR THE NE CWA. WED...SFC WARM FNT NEAR THE SRN MN/WI BORDER AND H85 WARM FNT INTO CENTRAL WI IS FCST TO REMAIN NEARLY STNRY THRU 00Z THU WELL TO THE NE OF DEEP TROF LINGERING IN THE DESERT SW. WELL TO THE NE OF THIS MAIN FORCING MECHANISM...12Z MODELS INDICATE DEEP LYR QVECTOR DVGC/SOME UPR CNVGC WL DOMINATE THRU MUCH OF THE AFTN UNDER INCRSGLY AMPLIFIED UPR RDG/HGT RISES TO THE N OF THE WARM FNT AND DIMINISHING DEEP LYR QVECTOR CNVGC THAT WL SUPPORT THE MAIN AREA OF SHRA/TS TO THE S AND SHIFT MAINLY TO THE E INTO THE LOWER LKS PARALLEL TO THE WARM FNT. SO SUSPECT THE MORE NMRS SHRA WL EXIT THE FAR SCENTRAL EARLY IN THE DAY AND LEAVE JUST ISOLD-SCT SHRA NEAR THE WI BORDER MOST OF THE DAY. INCLUDED MENTION OF SOME ELEVATED TS OVER THE FAR SCENTRAL LATER IN THE DAY TO ACCOUNT FOR AREA OF FCST LOWER SSI SHOWN BY THE MORE STABLE GFS. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 441 PM EDT TUE MAY 6 2014 WHEN...WHERE...AND HOW MUCH PRECIPITATION WILL FALL ALONG WITH THE THUNDERSTORM POTENTIAL WILL BE THE MAIN CONCERNS IN THIS LONG TERM PERIOD. THE SLIGHT RISK TS POTENTIAL FROM SPC IS ALONG THE WI BORDER FOR THE WEDNESDAY NIGHT PERIOD. ANOTHER CONCERN WITH THE WARMER AIR WILL BE FOG...WHICH IS STILL FCST TUESDAY NIGHT THROUGH FRIDAY...PARTICULARLY ACROSS LAKE SUPERIOR AND LAKE MI. THE 500MB LOW CURRENTLY ALONG THE ALBERTA AND SASKATCHEWAN BORDER AND TROUGH EXTENDING ACROSS NV AND S CA THIS AFTERNOON WILL EVER SO SLOWLY PROGRESS E...STRETCHING FROM SASKATCHEWAN THROUGH THE 4-CORNERS REGION BY 06Z THURSDAY...AS THE HIGH AMPLITUDE RIDGE CONTINUES TO BUILD ACROSS THE UPPER GREAT LAKES /WITH THE APEX OVER MAINLY CENTRAL AND E UPPER MI/. WENT WITH HIGH CHANCE TO LIKELY POPS FOR THE W HALF OF UPPER MI WEDNESDAY NIGHT...SO DESPITE THE SE WINDS...TEMPERATURES SHOULD BE ABLE TO COOL INTO THE LOW TO MID 40S. THE WARM FRONT LOOKS TO CROSS INTO S WI AROUND 00Z THURSDAY...WITH SEVERAL DISTURBANCES EJECTING NE INTO THE AREA TO KEEP CHANCE TO LIKELY POPS GOING THROUGH THURSDAY. THE WARMEST DAY OVER THE W HALF /PENDING RAIN SHOWER/ LOOKS TO BE THURSDAY AS 850MB TEMPS RISE TO A CWA AVG OF 18C. CURRENTLY FCSTING HIGHS IN THE MID TO UPPER 60S AS THE SFC LOW TRACKS ACROSS S MN AND EXTENDING UP THROUGH W LAKE SUPERIOR. JUST HOW FAR N THE WARM FRONT CAN PUSH ACROSS THE REGION WILL BE A CONCERN TS WISE. AT THIS POINT IT LOOKS LIKE THE WARM FRONT MAY HOOK UP THROUGH SW UPPER MI AND NEAR THE WI BORDER AT 12Z THURSDAY...BEFORE THE SFC LOW AND ASSOCIATED COLD FRONT CATCH UP TO IT AS THE LOW SHIFTS OVER E MN/NW WI AND THE W HALF OF UPPER MI BY 06Z FRIDAY. EXPECT THE LOW TO N OF LAKE SUPERIOR ACROSS ONTARIO BY MID DAY FRIDAY...DRAGGING THE INITIAL COLD FRONT E OF UPPER MI. THE SECONDARY FRONT MAY BRING SOME WRAP AROUND MOISTURE INTO THE W HALF OF THE CWA FOR THE REMAINDER OF FRIDAY...AS WINDS BECOME MORE W-NW. 850MB TEMPS SHOULD FALL TO AROUND 2C BY SATURDAY MORNING AS PW VALUES FALL TO AROUND 0.3IN...OR 45-60 PERCENT OF NORMAL. CURRENTLY HAVE UPPER 30S FCST FOR THE W THIRD OF THE CWA...BUT WOULD NOT BE SURPRISED IF IT ENDS UP BEING A BIT LOWER. CONTINUED THE TREND OF LOWERING DEW POINTS ON SATURDAY...AS DRY HIGH PRESSURE TEMPORARILY BUILDS ACROSS THE UPPER GREAT LAKES. THE NEXT LOW /PICKED UP MUCH BETTER CONSISTENCY WISE OFF THE 12Z GFS AND ECMWF/ LOOKS TO BE OVER S CANADA AND MN AT 12Z SUNDAY. LOOK FOR THE RETURN OF RAIN SHOWERS. KEPT ANY MENTION OF TS TO THE SW AT THIS TIME. PRECIP LOOKS TO CONTINUE INTO MONDAY...AS LOW PRESSURE LINGERS ACROSS THE REGION. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 744 PM EDT TUE MAY 6 2014 THERE WILL BE PLENTY OF HIGH AND MID CLOUDS AROUND DURING THIS FCST PERIOD WELL TO THE N OF WARM FRONT IN THE PLAINS. ALTHOUGH THERE WILL BE SOME LOWERING OF THE CLOUDS DURING THE DAY WED...A DRY...STEADY ESE FLOW OF DRY AIR OUT OF HIGH PRES IN ONTARIO EXITING ONLY SLOWLY TO THE NE SHOULD WORK TO MAINTAIN VFR CONDITIONS THRU THE FCST PERIOD...EVEN IF SOME -SHRA MOVE INTO KIWD/KSAW LATE TONIGHT OR WED MORNING. INCREASING WINDS ABOVE NOCTURNAL INVERSION MAY LEAD TO LLWS AT KIWD TONIGHT INTO WED MORNING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 322 PM EDT TUE MAY 6 2014 AS THE PRES GRADIENT TIGHTENS OVER LAKE SUPERIOR ON THE SW FLANK OF HI PRES RETREATING THRU ONTARIO AND IN ADVANCE OF LO PRES/ATTENDANT WARM FRONT LIFTING NE FROM THE PLAINS...EXPECT SLOWLY VEERING NE TO SE WINDS UP TO 15-25 KTS TO DOMINATE INTO THU. AS HIGHER DEW POINTS ARRIVE ON WED NIGHT/THU...FOG WILL DEVELOP OVER THE COLDER/ICE COVERED LAKE WATERS. WINDS WILL THEN VEER FROM THE SE TO THE W ON THU NIGHT THRU SAT AS THE LOW PRES TRACKS OVER FAR WESTERN LAKE SUPERIOR AND INTO NW ONTARIO. THE ARRIVAL OF DRIER AIR IN THE WAKE OF THIS LOW WILL CAUSE THE FOG TO DISSIPATE FRI NIGHT. WINDS WILL THEN SHIFT TO THE E ON SUN AS THE HI PRES TRAILING THE DEPARTING LO MOVES TO THE E. NO GALES SEEN IN THIS FORECAST PERIOD. && .HYDROLOGY... ISSUED AT 309 PM EDT TUE MAY 6 2014 STREAMS AND RIVERS WILL CONTINUE TO EXPERIENCE HIGHER LEVELS. LOCATIONS STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER IN HOUGHTON AND BARAGA COUNTIES AND THE TAHQUAMENON RIVER NEAR PARADISE. WHILE WET WEATHER WILL RETURN LATE TONIGHT THROUGH FRIDAY EVENING...RAINFALL SHOULD AROUND A TENTH OF AN INCH OR LESS THROUGH THE DAY WEDNESDAY. AT THE CURRENT TIME MOST OF THE RAIN LOOKS TO FALL OVER THE STURGEON RIVER BASIN THURSDAY EVENING. ADDING TO THIS WILL BE THE FEW INCHES OF SNOW WATER EQUIVALENT BEING SHOWN FROM NOHRSC SET UP FROM THE TIP OF THE KEWEENAW PENINSULA THROUGH PAINESDALE...DONKEN...AND WINONA. THIS LINES UP WELL WITH THE LATEST SNOW DEPTHS REPORTED AT PAINESDALE AND HERMAN. WILL SEE HOW THIS SNOW MELT /GIVEN WARMER FCST TEMPS FOR THE REST OF THE WEEK/ IMPACTS DOWNSTREAM RIVERS INCLUDING THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES AND THE TRAP ROCK RIVER. MOST IF NOT ALL OF THE SNOW COULD MELT BY THIS WEEKEND. FLOWS WILL LIKELY INCREASE OUT OF THE PRICKETT DAM OVER THE NEXT DAY OR TWO...WHICH WILL LEAD TO CONTINUED HIGHER LEVELS ON THE STURGEON RIVER IN HOUGHTON/BARAGA COUNTIES. WITH THE ALREADY HIGH LEVELS...ALSM4/CLLM4 MAY REACH FLOOD STAGE. BACK TO THE WET WEATHER EXPECTED THROUGH FRIDAY EVENING...SEVERAL ROUNDS OF SHOWERS AND POTENTIALLY THUNDERSTORMS WILL AFFECT THE AREA DURING THE SECOND HALF OF THE WORK WEEK. RAINFALL AMOUNTS WILL LIKELY EXCEED A HALF OF AN INCH FOR MOST OF UPPER MICHIGAN...AND LOCALIZED AMOUNTS OVER AN INCH SHOULD OCCUR WHERE THUNDERSTORMS TRACK. THIS WILL KEEP THE RIVER LEVELS HIGH INTO NEXT WEEKEND. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KF AVIATION...ROLFSON MARINE...KC HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
350 PM EDT MON MAY 5 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 259 PM EDT MON MAY 5 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF ACRS THE UPR LKS TO THE N OF SLOWLY BLDG RDG OVER THE SRN PLAINS. ALTHOUGH A SFC HI PRES RDG IS EXTENDING OVER UPR MI TO THE S OF HI PRES CENTER ACRS NW ONTARIO...PASSAGE OF SHRTWV EMBEDDED IN THIS FLOW/SOME DEEPER MSTR SHOWN ON THE 12Z INL RAOB RESULTED IN SOME -RA MIXED WITH SN THIS MRNG...ESPECIALLY OVER AREAS NEAR THE WI BORDER. BUT INCRSG DNVA/MID LVL DRYING HAS RESULTED IN A DIMINISHING TREND OF THE PCPN THIS AFTN EVEN THOUGH PLENTY OF LOWER CLDS HAVE LINGERED PER HIER MSTR SHOWN ON THE 12Z INL RAOB. THESE LOWER CLDS EXTENDS WNW THRU MOST OF THE N HALF OF MN AND NDAKOTA/SCENTRAL CANADA IN THE SFC E FLOW ON THE PERIPHERY OF THE SFC HI PRES IN NW ONTARIO. THERE HAS BEEN MORE CLRG OVER THE ECENTRAL UNDER THE SFC RDG AXIS. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE CLDS TRENDS/IMPACT ON TEMPS. TNGT...WITH LARGER SCALE QVECTOR DVGC/SUBSIDENCE UNDER BLDG HGTS... EXPECT DRY WX TO DOMINATE. BUT EVEN THOUGH SFC HI PRES IS FCST TO EXPAND FM NW ONTARIO INTO LK SUP...CONCERNED SOME LOWER CLDS/SC THAT EXTEND WELL TO THE WNW MAY LINGER...ESPECIALLY NEAR THE WI BORDER WHERE MORE...ALBEIT LGT PCPN FELL THIS MRNG. PAINTED THE LOWEST MIN TEMPS OVER THE INTERIOR E HALF...WHERE SKIES ARE MORE LIKELY TO BE MOCLR FOR A LONGER PERIOD OF TIME. TUE...UPR MI WL BE UNDER BLDG RDG AXIS DOWNSTREAM OF DEEPENING TROF IN THE ROCKIES. ALTHOUGH THE DAY WL START OUT MOSUNNY...EXPECT THE RETURN OF SOME MID/HI CLDS ESPECIALLY OVER THE W WITH RETURN WAD/ ISENTROPIC ASCENT AS THE SFC HI PRES SHIFTS TO THE E AND WINDS VEER TO THE SSW. WITH H85 TEMPS FCST TO RISE TO 3-4C IN THE AFTN AND DAYTIME HEATING/MIXING...DEEP MIXING TO NEAR H8 ON FCST SDNGS INDICATES MAX TEMPS WL REACH 55 TO 60 AWAY FM LK MODERATION IN LLVL ESE FLOW TO THE W OF RETREATING HI PRES. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 347 PM EDT MON MAY 5 2014 MUCH OF THE WEATHER FOR THIS LONG TERM PERIOD WILL BE WRAPPED AROUND THE SFC LOW ORGANIZING OFF THE HIGH PLAINS THROUGH THURSDAY. BY 00Z WEDNESDAY...THE MAIN 500MB LOW WILL BE SET UP ALONG THE ALBERTA/SASKATCHEWAN BORDER...WITH A SIGNIFICANT THROUGH EXTENDING DOWN THROUGH NV AND S CA. CLOSER TO HOME THE 500MB RIDGE WILL COVER MUCH OF THE CENTRAL AND SE U.S...UP THROUGH MANITOBA AND QUEBEC. THE INITIAL GLANCE OF SHOWERS WILL BE EXITING THE NW CORNER OF LAKE SUPERIOR...AS INCREASED WAA SURGES ACROSS THE UPPER GREAT LAKES. 850MB TEMPS AVERAGING 2C AT 00Z WEDNESDAY WILL RISE TO AN AVG 5C BY DAYBREAK WEDNESDAY ON SSE WINDS. DOWNSLOPE AREAS FROM IWD TO ONTONAGON SHOULD STAY RELATIVELY WARM OVERNIGHT...THAT IS UNLESS ISOTROPIC LIFT/WWA RAIN SHOWERS COME IN AS EXPECTED MAINLY AFTER 06Z WEDNESDAY. THE SFC LOW WILL STILL BE SET UP AROUND NE/KS AT 12Z WEDNESDAY. BASICALLY...A SERIES OF SHORTWAVES WILL CONTINUE TO EJECT NE OUT OF THE LONGWAVE TROUGH OVER THE SW STATES. MUCH OF THE NE PROGRESS OF THE SFC LOW WILL TAKE PLACE DURING THE DAY THURSDAY...SHIFTING FROM NE TO SW MN BY 00Z FRIDAY...IN RESPONSE TO THE EJECTING 500MB TROUGH SLIDING TO THE NE ND AREA. IT WILL BE DIFFICULT TO TIME INDIVIDUAL WAVES OF RAIN AT LEAST AT THIS TIME...BUT WET WEATHER LOOKS TO BE THE RULE WEDNESDAY AFTERNOON THROUGH AT LEAST FRIDAY MORNING. WILL KEEP THE MENTION OF FOG IN THE FCST WEDNESDAY NIGHT THROUGH FRIDAY MORNING...LIMITING THE POTENTIAL SLIGHTLY DURING THE DAY DUE TO INCREASED MIXING. WITH E-SE SFC WINDS...THE BEST POTENTIAL FOR FOG WILL LIKELY BE NEAR LAKE MICHIGAN...OVER THE KEWEENAW...AND THE HIGHER TERRAIN OF CENTRAL UPPER MICHIGAN. ELEVATED CONVECTION POTENTIAL LATE WEDNESDAY AFTERNOON INTO THURSDAY NIGHT AS THE WARM FRONT MOVES OVERHEAD. AS WITH LATEST FCST PACKAGE...WILL CONTINUE TO UTILIZE FCST MUCAPE AND SHOWALTER VALUES FOR THE INCLUSION OF TS. THE MAIN THREAT WILL LIKELY BE HEAVY RAIN GIVE THE ELEVATED NATURE. THE ENTIRE SYSTEM WILL BECOME MORE STACKED SFC-500MB BY 12Z FRIDAY OVER MN. PREVIOUS SOLUTIONS OVER THE WEEKEND SHOWED MORE RAPID DEEPENING OF THE LOW AS IT MOVED ACROSS ONTARIO FRIDAY AND TO JAMES BAY BY 12Z SATURDAY...MORE SIMILAR TO THE LATEST 12Z RUN OF THE ECMWF. THE MAIN COLD FRONT WILL CROSS UPPER MI ON FRIDAY...WITH A POTENT SECONDARY FRONT SWINGING IN AND FINALLY CHANGING THE NEAR SFC WINDS TO THE NW FRIDAY NIGHT/SATURDAY MORNING. AS A RESULT...WITH AGREEMENT OF THE GFS/ECMWF/GEM...THE BEST CHANCE FOR WIDESPREAD MODERATE RAIN WILL BE 00-06Z FRI OVER THE W HALF OF UPPER MI. BEHIND THE EXITING LOW SATURDAY AFTERNOON THROUGH SUNDAY NIGHT LOOK DRY FOR NOW...AS A RIDGE OF HIGH PRESSURE EXTENDS ACROSS THE UPPER GREAT LAKES. THERE IS SIGNIFICANT ENOUGH DISCREPANCIES IN THE FCST SOLUTION FROM SUNDAY ON TO RESULT IN A LOW CONFIDENCE FCST FOR DAYS 6/SUNDAY AND 7/MONDAY. BOTH THE GFS AND ECMWF HAVE A LOW SOMEWHERE TO OUR W AT 12Z SUNDAY...WITH A 500MB TROUGH EXTENDING S FROM THE 500MB LOW STILL STUCK ACROSS CANADA /NEAR N SASKATCHEWAN AND MANITOBA/. THE BEST CHANCE OF MAINLY DRY CONDITIONS WILL BE OVER N CENTRAL AND E UPPER MI NEAR LAKE SUPERIOR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 124 PM EDT MON MAY 5 2014 ALTHOUGH THERE COULD BE SOME LINGERING MVFR CIGS AT IWD EARLY IN THE FCST PERIOD...EXPECT VFR CONDITIONS AND LGT WINDS TO PREVAIL AT ALL 3 TAF SITES WITH DRY HI PRES DOMINATING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 259 PM EDT MON MAY 5 2014 WITH HI PRES LINGERING NEAR THE UPPER GREAT LAKES THRU TUE...EXPECT LIGHT WINDS. A STRONGER E WIND UP TO 20-25KTS WILL DEVELOP ON WED INTO THU AS A LO PRES AND ATTENDANT WARM FRONT APPROACH AND SHARPEN THE PRES GRADIENT OVER LAKE SUPERIOR. AS MOISTER AIR ARRIVES LATER ON WED/THU...EXPECT FOG TO DEVELOP OVER THE COLDER/ICE COVERED LAKE WATERS. WINDS WILL THEN VEER FROM THE SE TO THE W ON THU NIGHT THRU SAT AS THE LO PRES TRACKS OVER FAR WESTERN LAKE SUPERIOR AND INTO NW ONTARIO. THE ARRIVAL OF DRIER AIR IN THE WAKE OF THIS LO WILL CAUSE THE FOG TO DISSIPATE BY SAT. && .HYDROLOGY... ISSUED AT 347 PM EDT MON MAY 5 2014 STREAMS AND RIVERS WILL CONTINUE TO EXPERIENCE HIGHER LEVELS. LOCATIONS STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER IN HOUGHTON AND BARAGA COUNTIES AND THE TAHQUAMENON RIVER NEAR PARADISE. THE STURGEON RIVER NEAR NAHMA JUNCTION HAS CONTINUED IS STEADY DECLINE OVERNIGHT AND TODAY...GOING BELOW ADVISORY STAGE. WITH RELATIVELY DRY HIGH PRESSURE SETTLING IN ACROSS THE UPPER GREAT LAKES...MAINLY DRY CONDITIONS SHOULD PREVAIL UNTIL WEDNESDAY-FRIDAY. AS A RESULT OF THE STILL SLIGHTLY BELOW TEMPERATURES...WITH LOW TEMPERATURES BOTTOMING OUT NEAR OR BELOW FREEZING...RUNOFF CONTINUES TO BE A SLOW PROCESS...PARTICULARLY IN THE WOODED AND HIGHER ELEVATION AREAS OF THE WESTERN UPPER MI. THE LATEST SNOW WATER EQUIVALENT ANALYSIS FROM NOHRSC STILL HAS A FEW INCHES OF SNOW WATER EQUIVALENT FROM THE TIP OF THE KEWEENAW PENINSULA THROUGH PAINESDALE...DONKEN...AND WINONA. THIS LINES UP WELL WITH THE 20IN OF SNOW DEPTH REPORTED AROUND 8 AM SUNDAY STILL AT PAINESDALE...AND THE 16IN OF SNOW DEPTH AT HERMAN AROUND 8 AM MONDAY. THE AREAS THAT ARE DOWNSTREAM OF THIS MELTING SNOW WOULD BE THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES AND THE TRAP ROCK RIVER. EXPECT MULTIPLE DAYS WITH TEMPS IN THE 40S AND 50S THOUGH THE MIDDLE OF THIS WEEK TO SLOWLY MELT MOST IF NOT ALL OF THE REMAINING SNOW. FLOWS WILL LIKELY INCREASE OUT OF THE PRICKETT DAM OVER THE NEXT DAY OR TWO...WHICH WILL LEAD TO CONTINUED HIGHER LEVELS ON THE STURGEON RIVER IN HOUGHTON/BARAGA COUNTIES. WITH THE ALREADY HIGH LEVELS...ALSM4/CLLM4 MAY REACH FLOOD STAGE. THE NEXT CHANCE OF WIDESPREAD RAINFALL WILL OCCUR DURING THE LATTER HALF OF THE UPCOMING WORK WEEK...WHEN RAINFALL AMOUNTS MAY EXCEED A HALF OF AN INCH. THIS WILL LIKELY KEEP THE RIVER LEVELS HIGH INTO NEXT WEEKEND. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KF AVIATION...KC MARINE...KC HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
301 PM EDT MON MAY 5 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 259 PM EDT MON MAY 5 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF ACRS THE UPR LKS TO THE N OF SLOWLY BLDG RDG OVER THE SRN PLAINS. ALTHOUGH A SFC HI PRES RDG IS EXTENDING OVER UPR MI TO THE S OF HI PRES CENTER ACRS NW ONTARIO...PASSAGE OF SHRTWV EMBEDDED IN THIS FLOW/SOME DEEPER MSTR SHOWN ON THE 12Z INL RAOB RESULTED IN SOME -RA MIXED WITH SN THIS MRNG...ESPECIALLY OVER AREAS NEAR THE WI BORDER. BUT INCRSG DNVA/MID LVL DRYING HAS RESULTED IN A DIMINISHING TREND OF THE PCPN THIS AFTN EVEN THOUGH PLENTY OF LOWER CLDS HAVE LINGERED PER HIER MSTR SHOWN ON THE 12Z INL RAOB. THESE LOWER CLDS EXTENDS WNW THRU MOST OF THE N HALF OF MN AND NDAKOTA/SCENTRAL CANADA IN THE SFC E FLOW ON THE PERIPHERY OF THE SFC HI PRES IN NW ONTARIO. THERE HAS BEEN MORE CLRG OVER THE ECENTRAL UNDER THE SFC RDG AXIS. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE CLDS TRENDS/IMPACT ON TEMPS. TNGT...WITH LARGER SCALE QVECTOR DVGC/SUBSIDENCE UNDER BLDG HGTS... EXPECT DRY WX TO DOMINATE. BUT EVEN THOUGH SFC HI PRES IS FCST TO EXPAND FM NW ONTARIO INTO LK SUP...CONCERNED SOME LOWER CLDS/SC THAT EXTEND WELL TO THE WNW MAY LINGER...ESPECIALLY NEAR THE WI BORDER WHERE MORE...ALBEIT LGT PCPN FELL THIS MRNG. PAINTED THE LOWEST MIN TEMPS OVER THE INTERIOR E HALF...WHERE SKIES ARE MORE LIKELY TO BE MOCLR FOR A LONGER PERIOD OF TIME. TUE...UPR MI WL BE UNDER BLDG RDG AXIS DOWNSTREAM OF DEEPENING TROF IN THE ROCKIES. ALTHOUGH THE DAY WL START OUT MOSUNNY...EXPECT THE RETURN OF SOME MID/HI CLDS ESPECIALLY OVER THE W WITH RETURN WAD/ ISENTROPIC ASCENT AS THE SFC HI PRES SHIFTS TO THE E AND WINDS VEER TO THE SSW. WITH H85 TEMPS FCST TO RISE TO 3-4C IN THE AFTN AND DAYTIME HEATING/MIXING...DEEP MIXING TO NEAR H8 ON FCST SDNGS INDICATES MAX TEMPS WL REACH 55 TO 60 AWAY FM LK MODERATION IN LLVL ESE FLOW TO THE W OF RETREATING HI PRES. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 449 AM EDT MON MAY 5 2014 HIGH PRESSURE WILL BE IN CONTROL OVER THE U.P. TO START TUESDAY...AS AN UPPER RIDGE DEVELOPS OVER THE UPPER GREAT REGION IN RESPONSE TO A UPPER TROUGH DIVING SOUTHEAST TOWARDS THE SOUTHWEST CONUS. THIS UPPER TROUGH WILL DRIVE MUCH OF THE WEATHER FOR THE MIDDLE-END OF THE THIS WORK WEEK. FOR TUESDAY...FILTERED SUNSHINE IS EXPECTED AS HIGH CLOUDS ARE STREAMING NORTHEAST AHEAD OF THE UPPER TROUGH AND INCREASING SOUTHWEST FLOW ALOFT. WARMING TEMPS OVER LAND (INTERIOR HIGHS IN THE MID-UPPER 50S) AND LIGHT EASTERLY WINDS UNDER THE HIGH SHOULD LEAD TO LAKE BREEZES DEVELOPING AGAIN ON TUESDAY (ESPECIALLY OVER THE CENTRAL/EAST)...KEEPING HIGHS COOLER NEAR THE GREAT LAKES. IN THE AFTERNOON...BROAD WARM AIR ADVECTION BETWEEN 850-500MB OVER THE UPPER MISSISSIPPI VALLEY COULD PRODUCE AN ISOLATED SHOWER OR TWO OVER WESTERN LAKE SUPERIOR. THE REST OF THE WORK WEEK WILL BE DOMINATED BY A SERIES OF SHORTWAVES EJECTING NORTHEAST OUT OF THE LONGWAVE TROUGH OVER THE SOUTHWESTERN CONUS. THEN THURSDAY INTO FRIDAY...THE MAIN SHORTWAVE WITH THE UPPER TROUGH WILL SEND THE ASSOCIATED SURFACE LOW NORTHEAST FROM THE CENTRAL PLAINS AND THROUGH WESTERN LAKE SUPERIOR THURSDAY NIGHT. AS THE LOW TAKES SHAPE IN THE CENTRAL PLAINS TODAY...A WARM FRONT WILL DEVELOP EASTWARD ACROSS MISSOURI AND THE OHIO RIVER VALLEY. THIS FRONT WILL SLOWLY MAKE ITS WAY NORTH TOWARDS THE AREA WEDNESDAY INTO THURSDAY. SINCE CONVECTION THAT DEVELOPS ALONG THE FRONT WILL LIKELY PLAY A ROLE IN ITS NORTHWARD ADVANCEMENT...TEND TO LIKE THE SLOWER AND FARTHER SOUTH IDEA WITH THE WARM FRONT UNTIL THE LOW STARTS MOVING NORTHEAST WEDNESDAY NIGHT INTO THURSDAY. FORTUNATELY...THE 00Z MODELS HAVE TRENDED TOWARDS THAT IDEA. EVEN WITH THAT IDEA...IT STILL LOOKS LIKE SHOWERS WILL DEVELOP LATE TUESDAY NIGHT INTO WEDNESDAY MORNING AS THE FIRST WAVE OF BROAD WARM AIR ADVECTION SHIFTS THROUGH. HAVE CONTINUED THE IDEA OF INCREASING CHANCES THROUGH THE NIGHT...ALTHOUGH DID TREND UP TO LOW END LIKELYS OVER THE SOUTH CENTRAL CWA BASED OFF THE CONSISTENCY IN THE MODELS ON THE LOCATION OF THESE SHOWERS. TRENDED POPS BACK INTO THE CHANCE CATEGORY BY WEDNESDAY AFTERNOON AND CONTINUED INTO WEDNESDAY NIGHT AND THURSDAY MORNING. THIS TIME PERIOD WILL GREATLY DEPEND ON WHERE THE WARM FRONT IS LOCATED. IF IT IS IN SOUTHERN WISCONSIN AS SHOWN WITH THE 00Z GFS THE AREA WILL LIKELY SEE MORE OF A FOG/STRATUS/DRIZZLE PERIOD WITH INDICATIONS THAT DEEPER MOISTURE CUTS OUT. THE 00Z ECMWF SHIFTS THE FRONT A LITTLE FARTHER NORTH AND WOULD PUT THE AREA ON THE NORTHERN EDGE OF CONVECTION ALONG IT. THE GEM IS EVEN FARTHER NORTH AND WOULD PUT THE CONVECTIVE SHOWERS EVEN FARTHER TO THE NORTH. OPTED TO FOLLOW A COMPROMISE OF THE GFS/ECMWF AND GO WITH THE BETTER CHANCES TO THE SOUTH HALF OF THE CWA. WILL CONTINUE TO FOLLOW MUCAPE/SHOWALTER VALUES FOR THUNDER CHANCES DURING THIS PERIOD...WITH MUCH OF THE CONVECTION BEING ELEVATED. BEST OPPORTUNITY FOR MODERATE RAIN AND CONVECTION LOOKS TO BE ON THURSDAY AFTERNOON INTO THURSDAY NIGHT WITH THE LOW MOVING NORTHEAST TOWARDS THE AREA AND FINALLY ALLOWING THE WARM FRONT AND ASSOCIATED FORCING TO MOVE OVER THE AREA. WITH THE AMOUNT OF LOW LEVEL MOISTURE PRODUCING FOG AND LOW CLOUDS...WOULD EXPECT THE CONVECTION THAT DEVELOPS TO THE SOUTHWEST TO BECOME ELEVATED BY THE TIME IT GETS TO THIS AREA AND WILL LIMIT THE SEVERE THREAT...ALTHOUGH PERIODS OF HEAVY RAIN WOULD BE POSSIBLE. QPF AMOUNTS ARE TRICKY DUE TO CONVECTION...AS THEY NORMALLY ARE DURING THE WARM SEASON...SO HAVE BROAD BRUSHED THE AMOUNTS AT THIS POINT. OVERALL...SEEMS LIKE A DECENT CHANCE OF SEEING OVER 0.5IN AND DEPENDING WHERE THE WARM FRONT AND THEN CONVECTION ASSOCIATED WITH THE LOW MOVING THROUGH WESTERN LAKE SUPERIOR THURSDAY NIGHT...IT IS POSSIBLE LOCATIONS COULD SEE OVER AN INCH OF RAIN. HAVE CONTINUED THE INCREASE IN FOG WEDNESDAY INTO WEDNESDAY NIGHT OVER THE GREAT LAKES DUE TO THE WARM/MOIST AIR MOVING OVER THE VERY COLD (AND IN SOME AREAS ICE COVERED) GREAT LAKES. WITH THE CONSISTENT SIGNAL IN THE MODELS FOR THE LAST TWO NIGHTS...DID EXPAND THE FOG OVER THE LAND AREAS FOR WEDNESDAY NIGHT THROUGH FRIDAY MORNING. USED A COMBINATION OF WIND DIRECTION AND ELEVATION TO DEFINE THE AREAS...WITH SOME DECREASE DURING THE DAYTIME HOURS DUE TO MIXING. SINCE THERE WILL BE EAST-SOUTHEAST WINDS DURING THAT TIME...SHOWED THE WORST CONDITIONS NEAR LAKE MICHIGAN...OVER THE KEWEENAW...AND THE HIGHER TERRAIN OF CENTRAL UPPER MICHIGAN WITH UPSLOPE ASSISTANCE. THE SURFACE LOW WILL QUICKLY MOVE NORTHEAST INTO ONTARIO ON FRIDAY AND DRIER AIR ARRIVING BEHIND IT SHOULD BRING A WEST TO EAST DECREASE IN POPS AND FOG. THE 18Z GFS AND THE 00Z ECMWF DO HINT AT THE LOW LINGERING A LITTLE LONGER ON FRIDAY...WHICH WOULD LINGER PRECIP OVER THE NW HALF OF THE CWA INTO FRIDAY EVENING. FOLLOWED THE DRIER CONSENSUS...BUT WILL BE SOMETHING TO WATCH. FRIDAY NIGHT INTO SATURDAY LOOK TO BE DRY AS A RIDGE OF HIGH PRESSURE MOVES IN BEHIND THE DEPARTING LOW. ANOTHER UPPER TROUGH AND SURFACE LOW THEN LOOK TO AFFECT THE AREA ON SUNDAY AND BRING ANOTHER OPPORTUNITY FOR RAIN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 124 PM EDT MON MAY 5 2014 ALTHOUGH THERE COULD BE SOME LINGERING MVFR CIGS AT IWD EARLY IN THE FCST PERIOD...EXPECT VFR CONDITIONS AND LGT WINDS TO PREVAIL AT ALL 3 TAF SITES WITH DRY HI PRES DOMINATING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 259 PM EDT MON MAY 5 2014 WITH HI PRES LINGERING NEAR THE UPPER GREAT LAKES THRU TUE...EXPECT LIGHT WINDS. A STRONGER E WIND UP TO 20-25KTS WILL DEVELOP ON WED INTO THU AS A LO PRES AND ATTENDANT WARM FRONT APPROACH AND SHARPEN THE PRES GRADIENT OVER LAKE SUPERIOR. AS MOISTER AIR ARRIVES LATER ON WED/THU...EXPECT FOG TO DEVELOP OVER THE COLDER/ICE COVERED LAKE WATERS. WINDS WILL THEN VEER FROM THE SE TO THE W ON THU NIGHT THRU SAT AS THE LO PRES TRACKS OVER FAR WESTERN LAKE SUPERIOR AND INTO NW ONTARIO. THE ARRIVAL OF DRIER AIR IN THE WAKE OF THIS LO WILL CAUSE THE FOG TO DISSIPATE BY SAT. && .HYDROLOGY... ISSUED AT 449 AM EDT MON MAY 5 2014 STREAMS AND RIVERS WILL CONTINUE TO EXPERIENCE HIGHER LEVELS. LOCATIONS STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER IN HOUGHTON AND BARAGA COUNTIES...THE STURGEON RIVER NEAR NAHMA JUNCTION...AND THE TAHQUAMENON RIVER NEAR PARADISE. WITH RELATIVELY DRY HIGH PRESSURE SETTLING IN ACROSS THE UPPER GREAT LAKES...MAINLY DRY CONDITIONS SHOULD PREVAIL UNTIL WEDNESDAY-FRIDAY. AS A RESULT OF THE STILL SLIGHTLY BELOW TEMPERATURES...WITH LOW TEMPERATURES BOTTOMING OUT NEAR OR BELOW FREEZING...RUNOFF CONTINUES TO BE A SLOW PROCESS...PARTICULARLY IN THE WOODED AND HIGHER ELEVATION AREAS OF THE WESTERN UPPER MI. THE LATEST SNOW WATER EQUIVALENT ANALYSIS FROM NOHRSC STILL HAS A FEW INCHES OF SNOW WATER EQUIVALENT FROM THE TIP OF THE KEWEENAW PENINSULA THROUGH PAINESDALE...DONKEN...AND WINONA. THIS LINES UP WELL WITH THE 20IN OF SNOW DEPTH REPORTED AT 8 AM SUNDAY STILL AT PAINESDALE. THE AREAS THAT ARE DOWNSTREAM OF THIS MELTING SNOW WOULD BE THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES AND THE TRAP ROCK RIVER. EXPECT MULTIPLE DAYS WITH TEMPS IN THE 40S AND 50S THOUGH THE MIDDLE OF THIS WEEK TO SLOWLY MELT MOST IF NOT ALL OF THE REMAINING SNOW. FLOWS WILL LIKELY INCREASE OUT OF THE PRICKETT DAM OVER THE NEXT DAY OR TWO...WHICH WILL LEAD TO CONTINUED HIGHER LEVELS ON THE STURGEON RIVER IN HOUGHTON/BARAGA COUNTIES. WITH THE ALREADY HIGH LEVELS...ALSM4/CLLM4 MAY REACH FLOOD STAGE. THE NEXT CHANCE OF WIDESPREAD RAINFALL WILL OCCUR DURING THE LATTER HALF OF THE UPCOMING WORK WEEK...WHEN RAINFALL AMOUNTS MAY EXCEED A HALF OF AN INCH. THIS WILL LIKELY KEEP THE RIVER LEVELS HIGH INTO NEXT WEEKEND. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...KC MARINE...KC HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
323 AM CDT Mon May 5 2014 .SHORT TERM: (Through Tonight) Issued at 106 AM CDT Mon May 5 2014 Not much change from the prev forecast. Main focus will continue to be the location of the quasi-stationary fnt. This fnt is expected to lift nwd this morning, before being pushed back swd this afternoon thru tonight as the sfc ridge builds back into the region from the Great Lakes region. With a lack of moisture across the region, have kept the period dry. Mdls continue to over forecast dewpoint with no moisture return with a sfc ridge cutting off flow from the Gulf. Tilly .LONG TERM: (Tuesday through Sunday) Issued at 205 AM CDT Mon May 5 2014 Once again, not many changes to the prev forecast. Continued trending cooler with dewpoints as mentioned above. Gulf shud finally open up again by Thurs allowing moisture return once again. That said, expect dewpoints to pool along and just S of the sfc fnt. However, there is not enuf pooling expected to generate TSRA. The location of this fnt will determine temps thru Tues with upper 80s and lower 90s on the S side of the fnt, and 70s to 80 on the N side. By Wed morning, the fnt shud be well N of the region. Chance for TSRA increases on Thurs as cyclogenesis ramps up and the upper trof ejects into the Plains. Believe this system will behave very similar to the system last week where a leading s/w ejects into the region ahead of the main trof. This s/w is progd to push thru the CWA late Thurs into Thurs night. Another round of TSRA is expected across sern portions of the CWA on Fri as the main trof pushes thru. Either of these periods of TSRA have the potential of producing severe wx. However, questions regarding moisture return will determine severe wx potential and areas affected. For Sat and beyond, pattern becomes more typical of May with a quasi-stationary sfc boundary in the general area with waves of trofs moving thru the region. With questions regarding timing, have kept POPs in the lower chance range for now. As the large sfc ridge builds into the region, temps shud be cooler. Tilly && .AVIATION: (For the 00z TAFs through 00z Monday Evening) Issued at 431 PM CDT Sun May 4 2014 VFR through the period with occasional mid and high clouds. The primary forecast issue is the prevailing wind direction because a stalled frontal boundary will continue to waver across the region over the next few days. Winds will be easterly on the north side of the front, lgt/var along the front, and southerly to southwesterly on the south side of the front. Precipitation is very unlikely due to strong capping and lack of moisture. Local WRF and RAP forecasts in BUFKIT both show strong southwest winds above KCOU tonight at around 1000 ft during a time when surface winds should be from the south. Local WRF and RAP models also show fairly strong winds above KUIN at around 1000 ft, but the winds are more unidirectional with height through that layer compared to winds at KCOU. LLWS has been added to the TAFs for KCOU and KUIN. Specifics for KSTL: VFR through the period with occasional mid and high clouds. The prevailing wind direction will depend on the location of a quasistationary frontal boundary (easterly winds on the north side of the front and south to southwest winds on the south side of the front). Kanofsky && .PRELIMINARY POINT TEMPS/POPS: Saint Louis 90 60 86 64 / 10 5 5 5 Quincy 76 49 77 62 / 5 5 10 10 Columbia 88 57 87 64 / 10 5 5 5 Jefferson City 90 58 87 64 / 5 5 5 5 Salem 85 57 83 61 / 10 5 5 5 Farmington 89 57 86 61 / 5 5 5 5 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
130 AM CDT Mon May 5 2014 .SHORT TERM: (Through Tonight) Issued at 106 AM CDT Mon May 5 2014 Not much change from the prev forecast. Main focus will continue to be the location of the quasi-stationary fnt. This fnt is expected to lift nwd this morning, before being pushed back swd this afternoon thru tonight as the sfc ridge builds back into the region from the Great Lakes region. With a lack of moisture across the region, have kept the period dry. Mdls continue to over forecast dewpoint with no moisture return with a sfc ridge cutting off flow from the Gulf. Tilly .LONG TERM: (Monday through Next Sunday) Issued at 239 PM CDT Sun May 4 2014 The main issue for at least the next several days will be the location of the east-west quasi-stationary front and resultant impact on temperatures. Guidance is good agreement moving the boundary northward on Monday morning to around a Moberly-Matoon line by early afternoon. While there will be a few more clouds around on Monday, the character of the air mass and low level flow regime is not expected to change. Thus it appears highs in the 80s to lower 90s will be the norm within the warm sector, and in the 70s to the north of the front. The front then sags south again on Monday night as surface high pressure builds southeastward from the Great Lakes region. This southward position doesn`t appear to last long however as the front is forecast to retreat northward again on Tuesday, draped across northern MO into central IL by late afternoon and exiting the CWA by late evening. This northward retreat is in response to falling pressures across the Plains and the movement of an initial low pressure wave into eastern Nebraska. The entire region will be well within the warm sector on Wednesday with highs area-wide in the 80s. The models have been overforecasting the surface dew points recently and this trend will persist for the next several days as high pressure in the northern Gulf is inhibiting southerly return flow. The combination of warm temps aloft and limited low level moisture will result in an air mass capped to surface-based convection through Wednesday. I think Wednesday night will remain quiet and mild with a general increase in clouds. Things begin to change on Thursday with shower and thunderstorm chances ramping up, especially Thursday night into Friday. We should see a more robust return of low level moisture as the Gulf opens up, and the western U.S. upper trof ejects northeastward across the Rockies and Plains into the upper MS valley sending a cold front into the area Thursday night. This front will temporarily stall across portions of southern MO and southern IL late Friday into Friday night, before lifting back northward on Saturday. Glass && .AVIATION: (For the 00z TAFs through 00z Monday Evening) Issued at 431 PM CDT Sun May 4 2014 VFR through the period with occasional mid and high clouds. The primary forecast issue is the prevailing wind direction because a stalled frontal boundary will continue to waver across the region over the next few days. Winds will be easterly on the north side of the front, lgt/var along the front, and southerly to southwesterly on the south side of the front. Precipitation is very unlikely due to strong capping and lack of moisture. Local WRF and RAP forecasts in BUFKIT both show strong southwest winds above KCOU tonight at around 1000 ft during a time when surface winds should be from the south. Local WRF and RAP models also show fairly strong winds above KUIN at around 1000 ft, but the winds are more unidirectional with height through that layer compared to winds at KCOU. LLWS has been added to the TAFs for KCOU and KUIN. Specifics for KSTL: VFR through the period with occasional mid and high clouds. The prevailing wind direction will depend on the location of a quasistationary frontal boundary (easterly winds on the north side of the front and south to southwest winds on the south side of the front). Kanofsky && .PRELIMINARY POINT TEMPS/POPS: Saint Louis 60 86 64 87 / 5 5 5 10 Quincy 49 77 62 85 / 5 10 10 10 Columbia 57 87 64 87 / 5 5 5 10 Jefferson City 58 87 64 88 / 5 5 5 10 Salem 57 83 61 84 / 5 5 5 10 Farmington 57 86 61 85 / 5 5 5 10 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
936 PM MDT TUE MAY 6 2014 .UPDATE... LARGE UPPER LOW DIGGING INTO THE FOUR CORNERS REGION COMBINED WITH AN UPPER LOW OVER EASTERN IDAHO WILL PROVIDE A DIFFLUENT FLOW ALOFT AND A DEEP UPSLOPE FLOW ACROSS OUR FORECAST AREA...MAINLY THE WESTERN HALF...FOR THE NEXT 24 HOURS OR SO. AREAS OF RAIN CONTINUE FROM ABOUT BIG HORN AND TREASURE COUNTIES WESTWARD. COLD FRONT MADE ITS WAY THROUGH JUDITH GAP THIS AFTERNOON WHERE THE TEMPERATURE IS 32 DEGREES AND HAS RECENTLY GONE THROUGH BIG TIMBER (36 DEGREES) BUT HAS YET TO MAKE IT INTO BILLINGS. STILL BELIEVE THE COLDER AIR WILL SINK INTO BILLINGS AFTER MIDNIGHT. RAIN HAS MIXED WITH AND CHANGED TO SNOW ACROSS THE RED LODGE AREA THIS EVENING AND AT THE SAME TIME A FEW THUNDERSTORMS HAVE MOVED NORTH OUT OF WYOMING INTO CARTER COUNTY. THE BULK OF THE THUNDERSTORMS HAVE BEEN SOUTH INTO EAST CENTRAL AND NORTHEAST WYOMING THIS EVENING WHERE PLENTY OF SUNSHINE THIS AFTERNOON WARMED TEMPERATURES QUITE A BIT AND PROVIDED A GOOD DEAL OF INSTABILITY TO THAT AREA. CURRENT FORECAST REMAINS ON TRACK FOR TONIGHT INTO WEDNESDAY MORNING. HOWEVER...LATEST 00Z GUIDANCE HAS COME IN ABOUT 7 DEGREES WARMER FOR BILLINGS TONIGHT SO WILL NEED TO MONITOR THROUGHOUT THE NIGHT AS TOO HOW SOON THE RAIN CHANGES TO SNOW. CURRENT WINTER STORM WARNING AND ADVISORIES FOR THE MOUNTAINS AND FOOTHILLS CONTINUE TO LOOK GOOD. HOOLEY && .SHORT TERM...VALID FOR WED AND THU... DEEP UPPER LOW CURRENTLY EXISTS OVER NEVADA WITH DIFFLUENT/ UNSTABLE SOUTH FLOW OVER UT/WY...WITH HEALTHY TS ACTIVITY IN WESTERN WY. NORTHERN BRANCH TROF OVER ALBERTA/SASKATCHEWAN IS ASSOCIATED WITH A CANADIAN COLD FRONT WHICH HAS PUSHED SOUTHWARD TODAY AND IS NOW NEAR JUDITH GAP...A FEATURE THAT WILL SUPPLY OUR COLDER AIR TONIGHT. OUR REGION REMAINS IN A FAVORABLE REGION FOR DEEP ASCENT FOR AN EXTENDED PERIOD OF TIME...AND SHOWER ACTIVITY HAS RESPONDED ACCORDINGLY AND HAS BECOME WIDESPREAD ACROSS OUR WEST AND CENTRAL PARTS OVER THE PAST FEW HOURS. PCPN WILL CONTINUE TONIGHT AND TOMORROW WITH 1 TO 1.5 INCHES EXPECTED IN OUR WESTERN AND CENTRAL PARTS...GREATEST IN UPSLOPE AREAS...AND JUST A BIT LESS IN OUR EAST. COULD ALSO SEE A FEW THUNDERSTORMS IN OUR S/SE INTO THIS EVENING...WHERE SFC TEMPS HAVE WARMED TO NEAR 60F. STRONGER STORMS SHOULD STAY TO OUR SOUTH THOUGH FROM CENTRAL TO EAST CENTRAL WY ALONG/NEAR SFC BOUNDARY LOCATED THERE. A FEW INTERESTING OBSERVATIONS TO NOTE. FIRST IS THE AFTERNOON TEMPS FROM CTB-GTF ARE COLDER THAN ANY OF THE GUIDANCE SUGGESTS AT 21Z BY SEVERAL DEGREES...AND NOTICE THE 32F READING AT MONARCH CANYON AT 5200 FEET IN THE LITTLE BELTS INDICATIVE OF THE COLD ADVECTION/LOWERING FREEZING LEVELS WITH THE FRONTAL PASSAGE. NEXT IS THE DEWPT OF 24F AT CUT BANK WHICH MAY ALLOW FOR A COUPLE ADDITIONAL DEGREES OF WET BULBING DOWN ONCE THAT AIRMASS ADVECTS INTO OUR CWA LATER TONIGHT. THE LAST FEW RAP RUNS HAVE ALSO TRENDED COLDER FASTER AT 850MB...SHOWING THE 0C LINE THRU JUDITH GAP AROUND MIDNIGHT AND BILLINGS BY 09Z. ALL OF THIS POINTS TO INCREASED CONFIDENCE IN A TRANSITION TO SNOW ACROSS OUR WESTERN LOWER ELEVATIONS TONIGHT...PERHAPS A BIT EARLIER THAN PREVIOUSLY THOUGHT. WILL MAKE NO CHANGES TO ANY OF THE WINTER HIGHLIGHTS ALREADY IN EFFECT. THE BEARTOOTH ABSAROKAS AND THEIR FOOTHILLS WILL SEE SIGNIFICANT SNOWFALL ALONG THE NORTH ASPECTS BEGINNING BY THIS EVENING AND CONTINUING THRU MUCH OF TOMORROW. THE BIG HORNS ARE NOT OROGRAPHICALLY FAVORED IN THIS EVENT W/ SOUTH FLOW ALOFT...BUT STRONG ASCENT WILL BE ENOUGH FOR ADVY SNOW AMTS LATER TONIGHT AND WEDNESDAY. SO MAIN ISSUE TODAY WAS TO WORK OUT LOWER ELEVATIONS AND POTENTIAL IMPACTS. ENERGY DROPPING OUT OF BRITISH COLUMBIA IN NW FLOW ALOFT WILL ATTEMPT TO PHASE WITH GREAT BASIN TROF LATE TONIGHT/WEDNESDAY... ALLOWING FOR A WEAK MID LEVEL LOW TO STALL OUT NEAR WEST YELLOWSTONE...AGREED UPON BY THE GFS AND ECMWF. AS A RESULT WE WILL SEE A PROLONGED PERIOD OF ASCENT AND DEEP EASTERLY UPSLOPE WINDS IN OUR WEST EVEN AFTER PCPN CHANGES TO SNOW TONIGHT. HAVE OPTED TO ISSUE A WINTER WX ADVY FOR LIVINGSTON AREA...SWEET GRASS AND STILLWATER THRU TOMORROW...WITH EXPECTATION OF A FEW INCHES OF ACCUMULATION OVER THE HIGHER TERRAIN IN THIS AREA. FURTHER EAST...PCPN WILL BE ABUNDANT TONIGHT BUT MOST OF IT WILL BE RAIN. GFS/ECMWF SHOW SOME MID LEVEL DRY SLOTTING IN THIS AREA TOMORROW...EAST OF AFOREMENTIONED MID LEVEL LOW...SO NOT SURE IF THERE WILL BE ENOUGH SNOWFALL TO WARRANT A SNOW ADVY FOR AREAS SE OF BILLINGS INCLUDING SHERIDAN AND LAME DEER. THAT BEING SAID... WOULD EXPECT SOME ACCUMULATION OVER THE PASSES SUCH AS ABERDEEN HILL AND LAME DEER DIVIDE. WILL LET THE EVENING AND NIGHT SHIFTS MONITOR MODEL TRENDS HERE TO SEE IF AN ADVY IS NEEDED...BUT NOT ENOUGH CONFIDENCE NOW. AS FOR BILLINGS...IT IS GOING TO SNOW THE QUESTION IS HOW MUCH. SFC TEMPS WILL BOTTOM OUT IN THE LOW 30S BY TOMORROW MORNING AND WILL LIKELY STAY IN THE 30S THRU THE AFTN. THIS SHOULD BE ENOUGH FOR A LITTLE ACCUMULATION ON THE GRASS IN THE CITY...AND A LITTLE MORE OVER THE SURROUNDING HILLS...PERHAPS A COUPLE INCHES. IF TEMPS MANAGE TO MAKE IT TO THE UPPER 20S WE COULD SEE MORE THAN THIS...BUT NEITHER THE MODELS NOR UPSTREAM OBS SUGGEST THIS WILL HAPPEN. SO WILL KEEP YELLOWSTONE COUNTY OUT OF A WINTER HIGHLIGHT AT THIS TIME. FOR THOSE AREAS RECEIVING SNOWFALL...IMPACTS WOULD INCLUDE TRAVEL ALONG THE FOOTHILLS AND PASSES....AND POSSIBLY STRESSED BUDDING TREES FROM THE WET SNOW. OUR FAR EAST MAY MIX WITH SNOW TOMORROW MORNING BUT WITH LITTLE IF ANY ACCUMULATION FOR LOWER ELEVATIONS...IE FOR PLACES FROM MILES CITY TO BROADUS EASTWARD...AND MAYBE AN INCH OVER THE HILLS. SYSTEM WILL DEPART TO THE EAST WEDNESDAY NIGHT INTO EARLY THURSDAY AND WE WILL SEE A PERIOD OF DRY WEATHER THRU THURSDAY NIGHT. STRONG ENERGY COMING OUT OF THE CENTRAL ROCKIES ON THURSDAY DOES LOOK TO STAY TO OUR EAST. AFTER A VERY CHILLY DAY TOMORROW WITH HIGHS ONLY IN THE MID 30S TO MID 40S AND A COLD WEDNESDAY NIGHT WITH A FREEZE IN MANY LOCATIONS...TEMPS THURSDAY WILL RISE TO THE 50S/NEAR 60...STILL BELOW NORMAL FOR THIS TIME OF YEAR. JKL .LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE... FAIRLY UNSETTLED PATTERN IN THE LONG TERM PERIOD...WHICH BEGINS FRIDAY. MODELS ARE HINTING AT SOME SIMILAR FEATURES AT THE 500MB LEVEL...HOWEVER...SOME IMPORTANT THINGS NEED TO BE IRONED OUT BEFORE MAKING ANY BIG WHOLESALE CHANGES TO THE GOING FORECAST. NORTHWESTERLY TO ZONAL FLOW WILL DOMINATE THE NW UNITED STATES OVER THE WEEKEND. ACTUALLY...MONTANA FALLS IN SOMEWHAT OF A TRANSITION ZONE BETWEEN THE FLOW FROM AN UPPER LOW OVER NORTHERN CANADA AND ANOTHER SYSTEM WELL TO THE SOUTH. THE PROGRESSIVENESS OF THIS PATTERN WILL ALLOW SEVERAL VORT MAXES TO MAKE IT THROUGH THE REGION WELL INTO NEXT WEEK. TEMPERATURES WILL BE FAIRLY MILD FOR THIS TIME OF YEAR...WITH DAYTIME HIGHS STRUGGLING TO GET OUT OF THE 60S. DECIDED TO KEEP PRECIPITATION CHANCES AT OR NEAR CLIMO VALUES FOR MOST DAYS...WITH THE UNSETTLED NATURE OF THIS PATTERN AND LOW CONFIDENCE IN MODEL GUIDANCE. SINGER && .AVIATION... EXPECT WIDESPREAD PRECIP AND MVFR/IFR CONDITIONS TONIGHT...WITH RAIN TRANSITIONING TO SNOW LATER TONIGHT IN THE KLVM AND KBIL AREAS. PRECIP WILL MAINLY BE STRATIFORM IN NATURE...WITH AN OCCASIONAL RUMBLE OF THUNDER POSSIBLE ACROSS FAR SOUTHEASTERN MT THROUGH 05Z. MVFR/IFR CONDITIONS WILL CONTINUE INTO WEDNESDAY ACROSS MUCH OF THE REGION AS MOUNTAINS REMAIN OBSCURED. STC && .PRELIMINARY POINT TEMP/POPS... WED THU FRI SAT SUN MON TUE ----------------------------------------------------------- BIL 034/038 030/057 039/067 043/061 039/057 040/058 040/058 ++/O 52/W 02/T 53/W 33/W 33/W 33/W LVM 032/038 027/060 034/063 036/057 037/055 036/053 036/056 ++/O 61/B 14/T 53/W 33/W 33/W 33/W HDN 037/040 032/057 033/068 039/063 034/060 040/059 040/060 ++/O 52/W 02/T 53/W 33/W 33/W 33/W MLS 038/044 035/057 035/067 043/061 038/059 039/058 040/059 99/O 32/W 02/T 44/W 33/W 33/W 33/W 4BQ 041/044 034/054 034/067 041/062 036/059 039/058 040/056 ++/R 52/W 11/U 44/W 33/W 33/W 33/W BHK 040/045 035/053 032/063 041/060 036/056 038/055 038/055 89/R 42/W 11/U 45/W 33/W 33/W 33/W SHR 037/039 031/053 031/065 038/059 033/056 036/056 037/054 99/O 52/W 02/T 53/W 34/W 33/W 43/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL MIDNIGHT MDT WEDNESDAY NIGHT FOR ZONES 34-41-65. WINTER STORM WARNING IN EFFECT UNTIL MIDNIGHT MDT WEDNESDAY NIGHT FOR ZONES 56-66-67. WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL MIDNIGHT MDT WEDNESDAY NIGHT FOR ZONE 98. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
626 PM CDT TUE MAY 6 2014 .SHORT TERM...(TONIGHT THROUGH FRIDAY) ISSUED AT 305 PM CDT TUE MAY 6 2014 THE MAIN FORECAST CONCERNS IN THE SHORT TERM ARE SMALL PRECIP CHANCES TONIGHT...FIRE WEATHER CONCERNS AND HOW WARM TEMPERATURES WILL GET WEDNESDAY...THEN RAIN CHANCES WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. FIRE WEATHER FORECAST CONCERNS ARE ADDRESSED BELOW. THIS MORNING/S UPPER AIR MAPS SHOWED A MID TROPOSPHERIC TROF OVER THE WEST COAST WITH A RIDGE OVER THE SOUTHEAST U.S. SOUTHWEST FLOW ALOFT WAS TRANSPORTING SOME MID LEVEL MOISTURE INTO THE REGION. WARM...+12C H7 TEMPERATURES WERE NOTED OVER KANSAS. AT H85...THERE WAS SOME POOLING OF HIGHER DEWPOINTS AT OAX...HOWEVER IT WAS FAIRLY DRY AT H85 ACROSS THE PLAINS. THE SURFACE MAP AT 20Z...CONTINUED TO SHOW EAST AND SOUTHEAST FLOW WITH TEMPERATURES IN THE 70S...HOWEVER...THE MID 80 HAD MADE IT INTO FALLS CITY. BASED ON THE SURFACE WINDS AND TEMPERATURES...IT APPEARS THE WARM FRONT HAD LIFTED INTO SOUTHEAST NEBRASKA AND SHOULD BE AROUND LINCOLN. TONIGHT AND WEDNESDAY...THE SURFACE FRONT WILL LIFT NORTH INTO NORTHEAST NEBRASKA AS SURFACE LOW PRESSURE FORMS IN NORTHEAST COLORADO. THE LOW LEVEL JET WILL STRENGTHEN ACROSS EASTERN KANSAS INTO SOUTHEAST NEBRASKA AND THERE IS SOME BROAD SYNOPTIC LIFT ALONG WITH STEEP LAPSE RATES AND WEAK FRONTOGENESIS ALONG WITH SOME WEAK HEIGHT FALLS. THE TRAJECTORY FOR THE BEST PLACEMENT OF PRECIPITATION IS MORE TOWARD CENTRAL IOWA INTO MINNESOTA...HOWEVER SOMETHING ISOLATED MAY TRY TO DEVELOP IN OUR FORECAST AREA...ALONG AND NORTH OF THE WARM FRONT. DEEP MOISTURE APPEARS TO BE A LIMITING FACTOR AND MOST OF THE OPERATIONAL MODELS KEEP THE PRECIP CHANCES ON THE FRINGES OF OUR FORECAST AREA OR OUT OF THE AREA. FORECAST SOUNDINGS SHOW THAT IF SOMETHING HIGH BASED DOES DEVELOP...THERE WOULD BE THE POTENTIAL FOR SOME GUSTY WINDS WITH ANY ISOLATED STORMS. FOR NOW...FAR NORTHEAST NEBRASKA AND WESTERN IOWA IS WHERE OUR ISOLATED THUNDERSTORM CHANCES ARE MENTIONED. THE LATEST RAP IS HINTING AT SOMETHING IN SOUTHEAST NEBRASKA THIS EVENING...SO THIS WILL NEED TO BE WATCHED. WEDNESDAY AFTERNOON...THE VERY DRY AIR OVER PARTS OF SOUTHWEST KANSAS ARE FORECAST TO BE DRAWN NORTHEASTWARD AHEAD OF THE FRONT. THIS COMBINED WITH FAVORABLE MIXING AND SOUTHWEST WINDS SHOULD RESULT IN HOTTER TEMPERATURES IN THE 80S TO LOWER 90S...RESULTING VERY HIGH TO EXTREME FIRE DANGER CONDITIONS. IT DOES NOT LOOK LIKE RECORDS 95/96/99 OMAHA/LINCOLN/NORFOLK... BUT COULD GET CLOSE IF FULL HEATING IS REALIZED. AS DISCUSSED BELOW...DUE TO THE GREENESS...THE RFW WAS LIMITED TO THE AREA THAT HAS BEEN THE DRIEST. WEDNESDAY NIGHT INTO THURSDAY NIGHT...THE MID LEVEL TROF CONTINUE TO MOVE INTO THE PLAINS WITH MOISTURE RICH AIR RETURNING TO EASTERN KANSAS AND A NARROW AREA MAKING IT INTO EASTERN NEBRASKA AND WESTERN IOWA. DO HAVE SCATTERED SHOWERS AND THUNDERSTORMS MENTIONED. THERE IS A SEVERE POTENTIAL WITH THESE STORMS DUE TO THE MODERATE INSTABILITY AND FAVORABLE SHEAR PROFILES. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 305 PM CDT TUE MAY 6 2014 THERE ARE STILL SOME LARGE MODEL DIFFERENCES. STILL LOOKS LIKE A CHANCE FOR THUNDERSTORMS SATURDAY AND SATURDAY NIGHT. LARGER DIFFERENCES FOR THE REST OF THE WEEKEND INTO EARLY NEXT WEEK. TEMPERATURES STILL LOOK TO MOSTLY BE IN THE 60S AND 70S. && .AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 622 PM CDT TUE MAY 6 2014 MOSTLY VFR CONDITIONS ARE FORECAST FOR THE TAF SITES DURING THE PERIOD. A WARM FRONT WILL EXTEND THROUGH THE AREA WHICH WILL VARY THE SFC WINDS SLIGHTLY THROUGH THE PERIOD. EARLIER FORECAST MODELS WERE INDICATING MVFR CIGS WERE POSSIBLE...BUT HAVE REMOVED THIS FROM THE FORECAST AS CONDITIONS ARE NOT LOOKING AS PROBABLE. WILL CONTINUE TO MONITOR AND AMMEND AS NECESSARY. OTHERWISE...TSTMS COULD DEVELOP TO THE NORTHEAST OF THE TAF SITES OVERNIGHT BUT DO EXPECT DRY CONDITIONS AT ALL 3 TAF SITES. DID INCLUDE SOME LOW LEVEL WIND SHEAR AT KOMA AND KLNK FOR THE EARLY MORNING HOURS AS A STRONG LOW LEVEL JET INCREASES OVERNIGHT. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...RED FLAG WARNING FROM NOON TO 8 PM CDT WEDNESDAY FOR NEZ051-065- 066-078-088-089. IA...NONE. && $$ SHORT TERM...ZAPOTOCNY LONG TERM...ZAPOTOCNY AVIATION...KERN
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
620 AM CDT MON MAY 5 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 405 AM CDT MON MAY 5 2014 FORECAST MAX TEMPERATURES SATURDAY AND SUNDAY BUSTED BIG TIME AS THE DETERMINISTIC SOLNS ERRED BY AS MUCH AS 10F TOO WARM. THIS MAY BE A PROBLEM WITH TOO MUCH VERTICAL MIXING IN THE MODELS. THE EASTERLIES COMING OFF THE CANADIAN HIGH APPEAR TO BE STRONGER THAN ANTICIPATED. HIGHS SUNDAY IN THE DAKOTAS AND MINNESOTA WERE IN THE 40S AND 50S AND IT SNOWED IN MINOT. FOR TODAY THE TEMPERATURE FORECAST USES 50 PERCENT OF THE ECM AND A 50 PERCENT BLEND OF THE GEMREG AND MOS WHICH REPRESENT THE COOLER MODEL SOLNS. THERE ARE 13 MODELS TO CHOOSE FROM AND AT NORTH PLATTE THE RUC FORECASTS A HIGH OF 81F TODAY AND THE ECM 70F. SO WE WILL TRY UPPER 60S IN THE NORTHEAST TO NEAR 80 IN THE SOUTHWEST WITH MID 70S IN NORTH PLATTE. THE CANADIAN HIGH WILL CONTINUE TO RIDGE THROUGH THE NRN PLAINS AND UPPER MIDWEST SENDING COOL EASTERLIES THROUGH THE FCST AREA AND HIGH CLOUDINESS IS EXPECTED TO CONTINUE TODAY. FOR TONIGHT...LOW PRESSURE WILL DEEPEN ACROSS THE NRN HIGH PLAINS SETTING UP STRONG S-SE RETURN FLOW THROUGH WRN NEB. THIS SHOULD KEEP MIN TEMPS A BIT WARMER THAN THIS MORNING AS WINDS WILL INCREASE TO AROUND 15 KT. THE MODELS SHOW A DISTURBANCE MOVING THROUGH THE NRN PLAINS TONIGHT. ALL SOLNS KEEP THE FCST AREA DRY EXCEPT FOR THE GFS WHICH PRODUCES DRIZZLE. GIVEN THE VERY DRY AIR IN THE LOWER LEVELS AND THE FACT THAT NONE OF THE MODELS ARE PRODUCING ANYWHERE NEAR SATURATION IN THE BOUNDARY LAYER SHOWN BY THE GFS...THE FCST IS DRY TONIGHT WITH LOWS IN THE 40S. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 405 AM CDT MON MAY 5 2014 THE MAIN CONCERNS WITH THE FORECAST IN THE MID AND EXTENDED RANGE DEAL WITH PRECIPITATION CHANCES ALONG WITH A GOOD STRETCH OF BELOW NORMAL TEMPERATURES. THE QUASI-ZONAL PATTERN CURRENTLY SEEN OVER THE CONUS WILL GIVE WAY TO A MORE AMPLIFIED PATTERN IN THE NEXT SEVERAL DAYS AS THE UPPER LEVEL TROUGH OFF THE PACIFIC NORTHWEST COAST WILL DIG SOUTH TOWARDS THE FOUR CORNERS BY WEDNESDAY AFTERNOON. MEANWHILE...ANOTHER UPPER LEVEL LOW OVER CANADA WILL STAY NEARLY STATIONARY THIS WEEK OVER ALBERTA AND SASKATCHEWAN. THE MODELS ARE IN FAIR AGREEMENT WITH SLOWLY LIFTING THE SOUTHERN SYSTEM NORTHEAST ACROSS WESTERN NEBRASKA ON THURSDAY THEN INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION BY THE WEEKEND. ALTHOUGH THE 500MB LOW CENTERS ARE VERY CLOSE IN PLACEMENT AS THE SYSTEM LIFTS THROUGH THE AREA...GOING DOWN TOWARD THE SURFACE...MINOR DIFFERENCES IN THE LOCATION OF THE LOW IS HAVING AN IMPACT ON TEMPERATURES AND PRECIPITATION CHANCES...AS WELL AS PRECIPITATION TYPE FOR WEDNESDAY NIGHT. THE FIRST INFLUENCES FROM THE SYSTEM WILL BE ON TUESDAY. A SURFACE LOW WILL DEVELOP AHEAD OF THE UPPER LEVEL TROUGH ALLOWING SOUTHERLY FLOW TO BE ESTABLISHED DURING THE DAY. THIS WILL BRING GOOD WARM AIR ADVECTION INTO THE CENTRAL PLAINS ALONG WITH A GOOD MOISTURE FEED INTO THE REGION FROM THE GULF. THE QUESTION AT HAND FOR TUESDAY AFTERNOON AND EVENING WILL BE IF CONVECTION WILL FIRE...AND IF IT DOES...WHAT AREAS ARE MOST LIKELY TO SEE ACTIVITY. THE MODELS ARE SHOWING WEAK RIPPLES OF ENERGY PUSHING OUT OF THE BASE OF THE UPPER LEVEL TROUGH TO HELP PROVIDE LIFT. BUT...MOST OF THE MODEL SOLUTIONS WERE KEEPING THE MAJORITY OF THE FORECAST AREA CAPPED THROUGH THE EVENING HOURS WITH THE EXCEPTION OF PARTS OF THE PANHANDLE. ALSO...EVEN THOUGH MOISTURE RETURN WILL BE ONGOING BY SOMETIME IN THE AFTERNOON...CROSS-SECTIONS SHOW VERY ABUNDANT DRY AIR WHICH DOESN/T AID IN GROWING CONFIDENCE IN PRECIPITATION CHANCES. AT THIS TIME...HAVE CHANCES IN MAINLY FOR THE PANHANDLE...BUT IT IS POSSIBLE THAT THEY WILL NEED TO BE EXPANDED EAST THROUGH LATE EVENING. ON WEDNESDAY...THE UPPER LEVEL LOW IS PROJECTED TO MOVE INTO COLORADO. WITH THE SURFACE LOW STAYING FAIRLY STATIONARY...AND NOTHING LOOKING TO DISRUPT THE MOISTURE FLOWING NORTH...EXPECTING DEWPOINTS TO RISE SIGNIFICANTLY IN PARTS OF THE REGION DURING THE DAY. THAT BEING SAID...THE DRYLINE IS LOOKING TO MOVE ACROSS WESTERN KANSAS AND INTO SOUTHEAST NEBRASKA BY LATE WEDNESDAY AFTERNOON...BUT THE EASTERLY FLOW NORTH OF THE WARM FRONT IS LOOKING TO PULL A GOOD AMOUNT OF THE MOISTURE BACK TO THE WEST AND ACROSS MUCH OF THE LOCAL FORECAST AREA. IT DOES APPEAR THAT A PORTION OF THE REGION WILL BE IN THE DRY SLOT FOR A WHILE AS THE SYSTEM MOVES THROUGH...BUT AT THE CURRENT TIME...THAT INFLUENCE IS LOOKING TO BE FROM SOUTH CENTRAL INTO NORTHEAST NEBRASKA...IMPACTING ONLY THE FAR SOUTHEAST PARTS OF THE LOCAL AREA. AS ALL OF THIS IS OCCURRING...COLDER AIR WILL BE CIRCULATING AROUND THE EARLIER MENTIONED SYSTEM IN CANADA WHICH WILL BE PULLED SOUTH INTO THE AREA. THE AIRMASS DIFFERENCES WILL CAUSE FRONTGENETICAL FORCING TO DEVELOP AND EXPECT A GOOD DEFORMATION BAND ON THE BACK SIDE OF THE SYSTEM FOR LATER WEDNESDAY AND CONTINUING THROUGH THURSDAY. THERE ARE INDICATIONS THAT DECENT AMOUNTS OF PRECIPITATION WILL FALL WHEREVER THE DEFORMATION BAND SETS UP...WITH UP TO AN INCH AND A HALF OR TWO INCHES POSSIBLE. CURRENTLY THE MAJORITY OF THE PRECIPITATION LOOKS TO FALL WEST OF A LINE FROM IMPERIAL TO VALENTINE. ALSO WORTH MENTIONING...WITH THE COLDER AIR BEING PULLED INTO THE SYSTEM THERE IS POTENTIAL FOR AT LEAST A MIX OF RAIN AND SNOW FOR PARTS OF SHERIDAN AND WESTERN CHERRY COUNTIES. AT THIS TIME...LIMITED THE MENTION OF SNOW TO THE NORTHERN PARTS OF SHERIDAN COUNTY AS THERE IS NOT ENOUGH CONFIDENCE ON ANYTHING ACCUMULATING...OR THE SNOW FALLING IN GENERAL. TEMPERATURES FROM MOST MODELS ARE JUST 3 TO 4 DEGREES TOO WARM...WHILE THE NAM KEEPS SURFACE TEMPERATURES HOVERING RIGHT AROUND FREEZING WHICH WOULD ALLOW THE SNOW TO FALL AND PERHAPS ACCUMULATE. WILL KEEP A CLOSE EYE ON THIS IN THE COMING DAYS. THERE WILL ALSO BE A SLIGHT CHANCE FOR A STRONG TO SEVERE STORMS ON WEDNESDAY ON THE BACKSIDE OF THE LOW WHERE THE HIGHER MOISTURE POOLS. THESE STORMS WOULD BE ELEVATED WITH HAIL BEING THE MAIN THREAT. ALSO...ON THURSDAY LOOKING FOR STRONG NORTHWEST WINDS AS THE SYSTEM BEGINS TO DEPART TO THE EAST. THE PRESSURE GRADIENT WILL BE STRONG ENOUGH FOR SUSTAINED WINDS OF 20 TO 25KTS...BUT IF THE BOUNDARY LAYER MIXES...COULD BRING DOWN 40KT WINDS FROM 850MB. THE SYSTEM FINALLY EXITS THE REGION THURSDAY NIGHT...AND BEYOND THAT...QUITE A BIT OF UNCERTAINTY IS SEEN FROM THE LONGER TERM MODELS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 618 AM CDT MON MAY 5 2014 VFR IS EXPECTED ALL AREAS TODAY AND TONIGHT. HIGH CLOUDS WILL CONTINUE TO STREAM ACROSS THE CNTL ROCKIES AND CNTL PLAINS AS AN UPPER LEVEL DISTURBANCE MOVES THROUGH THE NRN PLAINS. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...BROOKS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
405 AM CDT MON MAY 5 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 405 AM CDT MON MAY 5 2014 FORECAST MAX TEMPERATURES SATURDAY AND SUNDAY BUSTED BIG TIME AS THE DETERMINISTIC SOLNS ERRED BY AS MUCH AS 10F TOO WARM. THIS MAY BE A PROBLEM WITH TOO MUCH VERTICAL MIXING IN THE MODELS. THE EASTERLIES COMING OFF THE CANADIAN HIGH APPEAR TO BE STRONGER THAN ANTICIPATED. HIGHS SUNDAY IN THE DAKOTAS AND MINNESOTA WERE IN THE 40S AND 50S AND IT SNOWED IN MINOT. FOR TODAY THE TEMPERATURE FORECAST USES 50 PERCENT OF THE ECM AND A 50 PERCENT BLEND OF THE GEMREG AND MOS WHICH REPRESENT THE COOLER MODEL SOLNS. THERE ARE 13 MODELS TO CHOOSE FROM AND AT NORTH PLATTE THE RUC FORECASTS A HIGH OF 81F TODAY AND THE ECM 70F. SO WE WILL TRY UPPER 60S IN THE NORTHEAST TO NEAR 80 IN THE SOUTHWEST WITH MID 70S IN NORTH PLATTE. THE CANADIAN HIGH WILL CONTINUE TO RIDGE THROUGH THE NRN PLAINS AND UPPER MIDWEST SENDING COOL EASTERLIES THROUGH THE FCST AREA AND HIGH CLOUDINESS IS EXPECTED TO CONTINUE TODAY. FOR TONIGHT...LOW PRESSURE WILL DEEPEN ACROSS THE NRN HIGH PLAINS SETTING UP STRONG S-SE RETURN FLOW THROUGH WRN NEB. THIS SHOULD KEEP MIN TEMPS A BIT WARMER THAN THIS MORNING AS WINDS WILL INCREASE TO AROUND 15 KT. THE MODELS SHOW A DISTURBANCE MOVING THROUGH THE NRN PLAINS TONIGHT. ALL SOLNS KEEP THE FCST AREA DRY EXCEPT FOR THE GFS WHICH PRODUCES DRIZZLE. GIVEN THE VERY DRY AIR IN THE LOWER LEVELS AND THE FACT THAT NONE OF THE MODELS ARE PRODUCING ANYWHERE NEAR SATURATION IN THE BOUNDARY LAYER SHOWN BY THE GFS...THE FCST IS DRY TONIGHT WITH LOWS IN THE 40S. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 405 AM CDT MON MAY 5 2014 THE MAIN CONCERNS WITH THE FORECAST IN THE MID AND EXTENDED RANGE DEAL WITH PRECIPITATION CHANCES ALONG WITH A GOOD STRETCH OF BELOW NORMAL TEMPERATURES. THE QUASI-ZONAL PATTERN CURRENTLY SEEN OVER THE CONUS WILL GIVE WAY TO A MORE AMPLIFIED PATTERN IN THE NEXT SEVERAL DAYS AS THE UPPER LEVEL TROUGH OFF THE PACIFIC NORTHWEST COAST WILL DIG SOUTH TOWARDS THE FOUR CORNERS BY WEDNESDAY AFTERNOON. MEANWHILE...ANOTHER UPPER LEVEL LOW OVER CANADA WILL STAY NEARLY STATIONARY THIS WEEK OVER ALBERTA AND SASKATCHEWAN. THE MODELS ARE IN FAIR AGREEMENT WITH SLOWLY LIFTING THE SOUTHERN SYSTEM NORTHEAST ACROSS WESTERN NEBRASKA ON THURSDAY THEN INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION BY THE WEEKEND. ALTHOUGH THE 500MB LOW CENTERS ARE VERY CLOSE IN PLACEMENT AS THE SYSTEM LIFTS THROUGH THE AREA...GOING DOWN TOWARD THE SURFACE...MINOR DIFFERENCES IN THE LOCATION OF THE LOW IS HAVING AN IMPACT ON TEMPERATURES AND PRECIPITATION CHANCES...AS WELL AS PRECIPITATION TYPE FOR WEDNESDAY NIGHT. THE FIRST INFLUENCES FROM THE SYSTEM WILL BE ON TUESDAY. A SURFACE LOW WILL DEVELOP AHEAD OF THE UPPER LEVEL TROUGH ALLOWING SOUTHERLY FLOW TO BE ESTABLISHED DURING THE DAY. THIS WILL BRING GOOD WARM AIR ADVECTION INTO THE CENTRAL PLAINS ALONG WITH A GOOD MOISTURE FEED INTO THE REGION FROM THE GULF. THE QUESTION AT HAND FOR TUESDAY AFTERNOON AND EVENING WILL BE IF CONVECTION WILL FIRE...AND IF IT DOES...WHAT AREAS ARE MOST LIKELY TO SEE ACTIVITY. THE MODELS ARE SHOWING WEAK RIPPLES OF ENERGY PUSHING OUT OF THE BASE OF THE UPPER LEVEL TROUGH TO HELP PROVIDE LIFT. BUT...MOST OF THE MODEL SOLUTIONS WERE KEEPING THE MAJORITY OF THE FORECAST AREA CAPPED THROUGH THE EVENING HOURS WITH THE EXCEPTION OF PARTS OF THE PANHANDLE. ALSO...EVEN THOUGH MOISTURE RETURN WILL BE ONGOING BY SOMETIME IN THE AFTERNOON...CROSS-SECTIONS SHOW VERY ABUNDANT DRY AIR WHICH DOESN/T AID IN GROWING CONFIDENCE IN PRECIPITATION CHANCES. AT THIS TIME...HAVE CHANCES IN MAINLY FOR THE PANHANDLE...BUT IT IS POSSIBLE THAT THEY WILL NEED TO BE EXPANDED EAST THROUGH LATE EVENING. ON WEDNESDAY...THE UPPER LEVEL LOW IS PROJECTED TO MOVE INTO COLORADO. WITH THE SURFACE LOW STAYING FAIRLY STATIONARY...AND NOTHING LOOKING TO DISRUPT THE MOISTURE FLOWING NORTH...EXPECTING DEWPOINTS TO RISE SIGNIFICANTLY IN PARTS OF THE REGION DURING THE DAY. THAT BEING SAID...THE DRYLINE IS LOOKING TO MOVE ACROSS WESTERN KANSAS AND INTO SOUTHEAST NEBRASKA BY LATE WEDNESDAY AFTERNOON...BUT THE EASTERLY FLOW NORTH OF THE WARM FRONT IS LOOKING TO PULL A GOOD AMOUNT OF THE MOISTURE BACK TO THE WEST AND ACROSS MUCH OF THE LOCAL FORECAST AREA. IT DOES APPEAR THAT A PORTION OF THE REGION WILL BE IN THE DRY SLOT FOR A WHILE AS THE SYSTEM MOVES THROUGH...BUT AT THE CURRENT TIME...THAT INFLUENCE IS LOOKING TO BE FROM SOUTH CENTRAL INTO NORTHEAST NEBRASKA...IMPACTING ONLY THE FAR SOUTHEAST PARTS OF THE LOCAL AREA. AS ALL OF THIS IS OCCURRING...COLDER AIR WILL BE CIRCULATING AROUND THE EARLIER MENTIONED SYSTEM IN CANADA WHICH WILL BE PULLED SOUTH INTO THE AREA. THE AIRMASS DIFFERENCES WILL CAUSE FRONTGENETICAL FORCING TO DEVELOP AND EXPECT A GOOD DEFORMATION BAND ON THE BACK SIDE OF THE SYSTEM FOR LATER WEDNESDAY AND CONTINUING THROUGH THURSDAY. THERE ARE INDICATIONS THAT DECENT AMOUNTS OF PRECIPITATION WILL FALL WHEREVER THE DEFORMATION BAND SETS UP...WITH UP TO AN INCH AND A HALF OR TWO INCHES POSSIBLE. CURRENTLY THE MAJORITY OF THE PRECIPITATION LOOKS TO FALL WEST OF A LINE FROM IMPERIAL TO VALENTINE. ALSO WORTH MENTIONING...WITH THE COLDER AIR BEING PULLED INTO THE SYSTEM THERE IS POTENTIAL FOR AT LEAST A MIX OF RAIN AND SNOW FOR PARTS OF SHERIDAN AND WESTERN CHERRY COUNTIES. AT THIS TIME...LIMITED THE MENTION OF SNOW TO THE NORTHERN PARTS OF SHERIDAN COUNTY AS THERE IS NOT ENOUGH CONFIDENCE ON ANYTHING ACCUMULATING...OR THE SNOW FALLING IN GENERAL. TEMPERATURES FROM MOST MODELS ARE JUST 3 TO 4 DEGREES TOO WARM...WHILE THE NAM KEEPS SURFACE TEMPERATURES HOVERING RIGHT AROUND FREEZING WHICH WOULD ALLOW THE SNOW TO FALL AND PERHAPS ACCUMULATE. WILL KEEP A CLOSE EYE ON THIS IN THE COMING DAYS. THERE WILL ALSO BE A SLIGHT CHANCE FOR A STRONG TO SEVERE STORMS ON WEDNESDAY ON THE BACKSIDE OF THE LOW WHERE THE HIGHER MOISTURE POOLS. THESE STORMS WOULD BE ELEVATED WITH HAIL BEING THE MAIN THREAT. ALSO...ON THURSDAY LOOKING FOR STRONG NORTHWEST WINDS AS THE SYSTEM BEGINS TO DEPART TO THE EAST. THE PRESSURE GRADIENT WILL BE STRONG ENOUGH FOR SUSTAINED WINDS OF 20 TO 25KTS...BUT IF THE BOUNDARY LAYER MIXES...COULD BRING DOWN 40KT WINDS FROM 850MB. THE SYSTEM FINALLY EXITS THE REGION THURSDAY NIGHT...AND BEYOND THAT...QUITE A BIT OF UNCERTAINTY IS SEEN FROM THE LONGER TERM MODELS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1239 AM CDT MON MAY 5 2014 THE SHORT RANGE FORECAST SOUNDINGS ARE SHOWING A WEAK FOG SIGNAL IN THE PLATTE RIVER VALLEY WITH MOISTURE BELOW THE 875MB LEVEL INCREASING WITH HEIGHT. LIGHT EAST WIND IN THE PLATTE RIVER VALLEY WOULD SUPPORT SOME BR/FG TONIGHT...SO PATCHY FOG/MIST IS POSSIBLE TONIGHT. THE EVENING SOUNDING AT LBF HAS A FOG SIGNAL WITH UNIFORM MOISTURE INDICATED IN THE LOWEST 1000 FEET BUT THE TEMPERATURE WOULD NEED TO BE BELOW 40F. AT THIS TIME...WE ARE NOT EXPECTING TEMPERATURES TO BE THAT LOW. SINCE HIGHER MOISTURE IS INDICATED UPWIND OF LBF...IT IS POSSIBLE THAT THE VERTICAL MOISTURE PROFILE WILL CHANGE OVER THE NEXT 4-6 HOURS AND CONDITIONS MAY BECOME MORE FAVORABLE FOR FOG DEVELOPMENT. WITH THE UNCERTAINTY STILL PRETTY HIGH...WE WILL NOT INCLUDE VISIBILITY BELOW 3SM IN THE TERMINAL FORECAST FOR LBF BUT WILL INCLUDE 3SM WITH BCFG IN THE FORECAST. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...BROOKS AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
745 PM MDT TUE MAY 6 2014 .UPDATE... UPDATED FORECAST TO ISSUE A WIND ADVISORY FOR WEDNESDAY FOR MUCH OF CENTRAL...SOUTH CENTRAL AND EASTERN NEW MEXICO. ALSO UPGRADED THE FIRE WEATHER WATCH FOR THE MIDDLE RIO GRANDE VALLEY. TIMING OF THE COLD FRONT WEDNESDAY AROUND MAX HEATING HERE IN THE MIDDLE RIO GRANDE VALLEY LENDING MORE CONFIDENCE TO SEEING AT LEAST A COUPLE HOURS OF WIND ADVISORY SPEEDS...WITH BLOWING DUST LOOKING MORE LIKELY AS WELL. THE WIND ADVISORY EXPIRES AT 8 PM MDT WEDNESDAY... BUT MAY NEED TO BE EXTENDED FOR SOME OF THE EAST CENTRAL AND NORTHEAST PLAINS GIVEN THE TIMING OF THE CORE OF STRONGER WINDS ALOFT AS THE UPPER TROUGH PULLS NE ACROSS NW NEW MEXICO AND INTO COLORADO. 11 && .PREV DISCUSSION...537 PM MDT TUE MAY 6 2014... .AVIATION... 00Z TAF CYCLE GUSTY WINDS ARE THE PREDOMINANT AVIATION CONCERN ACROSS NORTHERN AND CENTRAL NM EARLY THIS EVENING...AND THIS WILL BE THE CASE INTO WEDNESDAY AS WELL. THROUGH 07/0200UTC SOME OCCASIONAL GUSTS TO 30-35 KT WILL BE POSSIBLE ALMOST ACROSS THE ENTIRE FORECAST AREA BEFORE THEY DIMINISH OVERNIGHT. SOME SMOKE MAY BE VISIBLE NEAR AND DOWNWIND OR EAST NORTHEAST OF THE JEMEZ MOUNTAINS WHERE PRESCRIBED BURNS HAVE BEEN ONGOING...BUT NO PERCEIVABLE VISIBILITY REDUCTIONS ARE EXPECTED. WINDS WILL BE STRONGEST IN CENTRAL TO EASTERN NEW MEXICO WEDNESDAY AFTERNOON WHERE OCCASIONAL GUSTS WILL APPROACH 40 TO 45 KT. 52 && .PREV DISCUSSION...246 PM MDT TUE MAY 6 2014... .SYNOPSIS... THE NEXT STORM SYSTEM APPROACHING NEW MEXICO FROM THE WEST WILL DELIVER ANOTHER PUNCH OF SPRING WINDS AND BLOWING DUST WEDNESDAY. WIDESPREAD DANGEROUS FIRE WEATHER CONDITIONS WILL ACCOMPANY THE WIND AS CONDITIONS ARE EXTREMELY DRY OVER THE AREA. THE WELL ABOVE NORMAL HIGH TEMPERATURES OVER THE PAST SEVERAL DAYS WILL COOL BACK TO BELOW NORMAL FOR THE WEST WEDNESDAY...THEN ALL AREAS THURSDAY AND FRIDAY. A FEW LOCATIONS ACROSS THE NORTHERN AND WESTERN HIGH TERRAIN ALSO HAVE THE POTENTIAL FOR A COUPLE SHOWERS AND THUNDERSTORMS BOTH DAYS. TEMPERATURES WILL REBOUND AGAIN BACK NEAR TO SLIGHTLY ABOVE NORMAL FOR THE WEEKEND WITH WIDESPREAD BREEZY CONDITIONS EXPECTED. && .DISCUSSION... MSAS ANALYSIS SHOWED SURFACE LOW PRESSURE DEEPENED TO 994MB AT 19Z OVER SE COLORADO AND THE 19Z RAP INDICATES THIS WILL CONTINUE TO 989MB BY 00Z. MEANWHILE UPPER LEVEL WINDS ARE INCREASING OVER THE REGION AHEAD OF AN APPROACHING H5 UPPER LOW OVER EAST CENTRAL NV. SURFACE OBS AT KLVS HAVE BEEN NEAR OR JUST ABOVE WIND ADVISORY A COUPLE TIMES BUT SINCE ISOLD IN NATURE WILL NOT ISSUE HIGHLIGHTS. MORE SIGNIFICANT WINDS WILL ARRIVE WEDNESDAY AS THE CORE OF A 40-50KT 700-500MB JET SLIDES OVER CENTRAL/EASTERN NM. WILL PASS ALONG WIND ADVISORY HIGHLIGHTS TO OVERNIGHT CREW. ON THE QPF SIDE OF THINGS THERE ISNT MUCH TO GET EXCITED ABOUT. WPC PROBABILISTIC QPF VALUES FOR 0.10 OR MORE DO SHOW VALUES AROUND 30 PCT OVER SW FACING SLOPES OF THE NW MTS WEDNESDAY. GFS/NAM LIFTED INDICES ARE NEAR -2C FOR TMRW AFTERNOON SO THUNDER POTENTIAL STILL EXISTS. RAISED POPS INTO THE 40 AND 50 PCT RANGE BUT AMOUNTS WILL BE VERY LIGHT. ALSO TOSSED IN DUST FOR THE NW PLATEAU. MAX TEMPS WILL TREND COLDER OVER THE WEST THEN 5 TO 15F BLW NORMAL FOR ALL AREAS THURSDAY. IT WILL FEEL QUITE COOL THURSDAY WITH WIDESPREAD BREEZY CONDITIONS AND ANOTHER ROUND OF SHOWERS/ISOLD STORMS NEAR AND EAST OF HIGH TERRAIN. AGAIN QPF WILL BE VERY LIGHT. FLOW WILL RELAX SLIGHTLY AND BECOME MORE ZONAL WITH WARM ADVECTION THRU THE WEEKEND. GENERALLY CLEAR SKIES ARE EXPECTED MOST AREAS WITH THE EXCEPTION OF HIGH CLOUDS OVER THE NORTH. 700MB TEMPS WILL WARM TO NEAR +12C WHICH IS NEAR THE 75 PERCENTILE FOR MID MAY. THAT WILL TRANSLATE TO HIGHS 5 TO 15F ABV NORMAL AGAIN. MODEL CONSISTENCY AND OUTLOOK FOR NEXT WEEK IS ALMOST COMICAL SO WILL LEAVE THAT FOR LATER. GUYER && .FIRE WEATHER... WIDESPREAD RED FLAG CONDITIONS WILL CONTINUE THROUGH MID EVENING. HAVE UPGRADED ZONES 103 AND 107 TO A RED FLAG WARNING FOR WEDNESDAY LATE MORNING TO EARLY EVENING. WILL LEAVE ZONE 106 AS A WATCH AND LET THE STELLAR NIGHT CREW TAKE ONE MORE LOOK. CHANGE IN THE WEATHER IS ON THE WAY WITH COOLER TEMPERATURES AND EVENTUALLY LESS WIND...THANKS TO A POTENT COLD FRONT TOMORROW AND UPPER LEVEL DISTURBANCE. ONLY MODEST PRECIPITATION CHANCES ACROSS THE NORTH IN THE WEDNESDAY THROUGH THURSDAY TIME PERIOD. WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS TO CONTINUE THROUGH MID EVENING FOR MUCH OF NORTHERN AND CENTRAL NEW MEXICO. WINDS TO SUBSIDE DURING THE NIGHT ASIDE FROM MODERATE BREEZES OVER THE MOUNTAINS AND EAST SLOPES. WINDS WILL INCREASE QUICKLY WEDNESDAY AND BE THE STRONGEST WINDS OF THE WEEK. CRITICAL FIRE WEATHER WILL BE EASILY REACHED OVER MOST CENTRAL AND ALL EASTERN AREAS. HIGH TEMPERATURES WILL BE LOWER EVERYWHERE...BUT STILL ABOVE NORMAL IN THE FAR EAST. THIS WILL BE THE AREA WITH THE LOWEST RH VALUES WITH SINGLE DIGIT READINGS FOR ABOUT 10 HOURS. HAINES VALUES TO BE HIGH TO MODERATE. AREAS TO THE WEST ARE MORE IN THE GREY AREA AS TO HOW TO TREAT THE CRITICAL FIRE WEATHER CONDITIONS. WHILE WINDS WILL BE VERY STRONG AND HUMIDITIES BELOW 15 PERCENT FOR MANY HOURS...THE TEMPERATURES WILL BE NEAR TO BELOW NORMAL IN ZONES 103 AND 107. WITH HAINES VALUES STILL PARTLY IN THE HIGH CATEGORY IN ZONES 103 AND 10 WILL GO AHEAD AND UPGRADE THESE ZONES TO A RED FLAG WARNING FOR WEDNESDAY. WILL LEAVE ZONE 106...MIDDLE RIO GRANDE VALLEY...AS A WATCH. CERTAINLY WINDS AND HUMIDITIES WILL BE CRITICAL FOR SEVERAL HOURS...BUT LOW TO MODERATE HAINES VALUES AND HIGHS SEVERAL DEGREES BELOW NORMAL BRING A MIXED SIGNAL AS TO JUST HOW CRITICAL THIS AREA WILL BE. AS MENTIONED ABOVE WILL LET NIGHT CREW MAKE THE CALL ON ZONE 106. WILL NEED TO FACTOR IN HOW INCREDIBLY DRY IT HAS BEEN LATELY AS WELL. AS FOR CHANCE OF PRECIPITATION...ONLY THE NORTHWEST AND NORTH CENTRAL HIGHER TERRAIN COULD SEE A SHOWER OR THUNDERSTORM WEDNESDAY. MUCH COOLER AIR WILL CONTINUE TO POUR INTO THE STATE WEDNESDAY NIGHT AND THURSDAY. WINDS WILL ALSO FINALLY DIMINISH FOR MOST AREAS. IT WILL STILL BE BREEZY ACROSS THE EAST CENTRAL AREAS. A FEW RAIN AND MOUNTAIN SNOW SHOWERS WILL BE POSSIBLE ACROSS THE WEST AND NORTH BUT NO WETTING PRECIPITATION. FRIDAY SHOULD BE DRY AND MILDER WITH NEAR NORMAL TEMPERATURES AND NOT MUCH WIND. THE WEEKEND SHOULD BE MOSTLY DRY WITH THE WARMING TREND CONTINUING SATURDAY AND LEVELING OFF ON SUNDAY. AN APPROACHING BACK DOOR COLD FRONT COULD TRIGGER A SHOWER IN THE NORTHEAST AND OVER THE NORTHERN MOUNTAINS LATE SUNDAY. THE START OF NEXT WEEK WILL BE COOLER IN THE EAST. IT WILL BE DRY ASIDE FROM A NORTHERN MOUNTAIN SHOWER. THE EUROPEAN MODEL IS MORE BULLISH WITH A TROUGH AND THE PRECIPITATION POTENTIAL FOR EARLY NEXT WEEK. THEN THE GFS GOES BONKERS WITH A STRONG BACK DOOR COLD FRONT BY THE MIDDLE OF NEXT WEEK AND SIGNIFICANT PRECIPITATION IN THE EAST BEHIND THE FRONT. JUST WISHFUL THINKING AT THIS POINT. CHJ && .AVIATION... 18Z TAF CYCLE STORM OVER THE GREAT BASIN TO HEAD SLOWLY EAST. NEAR SFC WINDS STRONGER TODAY THAN MONDAY. SW WIND GUSTS OF 28-30 KTS AT FMN...ABQ...AEG AND SAF. SW WIND GUSTS OF 35-37 KTS OTHER TAF SITES. NO RESTRICTIONS TO VSBY DUE TO DUST IN ANY TAF FORECAST BUT COULD BE SOME MODEST RESTRICTIONS ARE NOT ENTIRELY OUT OF THE QUESTION...MAINLY FOR LVS...TCC AND ROW. OTHERWISE...VFR CONDITIONS ARE FORECAST TO PERSIST. STRONG WINDS AGAIN WED OVER THE E...LOWER SPEEDS IN THE WEST. 40 && .ABQ WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR THE FOLLOWING ZONES...NMZ103>109. RED FLAG WARNING FROM 10 AM TO 8 PM MDT WEDNESDAY FOR THE FOLLOWING ZONES...NMZ103-104-106>108. WIND ADVISORY FROM NOON TO 8 PM MDT WEDNESDAY FOR THE FOLLOWING ZONES...NMZ515-519>540. && $$ 11
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
537 PM MDT TUE MAY 6 2014 .AVIATION... 00Z TAF CYCLE GUSTY WINDS ARE THE PREDOMINANT AVIATION CONCERN ACROSS NORTHERN AND CENTRAL NM EARLY THIS EVENING...AND THIS WILL BE THE CASE INTO WEDNESDAY AS WELL. THROUGH 07/0200UTC SOME OCCASIONAL GUSTS TO 30-35 KT WILL BE POSSIBLE ALMOST ACROSS THE ENTIRE FORECAST AREA BEFORE THEY DIMINISH OVERNIGHT. SOME SMOKE MAY BE VISIBLE NEAR AND DOWNWIND OR EAST NORTHEAST OF THE JEMEZ MOUNTAINS WHERE PRESCRIBED BURNS HAVE BEEN ONGOING...BUT NO PERCEIVABLE VISIBILITY REDUCTIONS ARE EXPECTED. WINDS WILL BE STRONGEST IN CENTRAL TO EASTERN NEW MEXICO WEDNESDAY AFTERNOON WHERE OCCASIONAL GUSTS WILL APPROACH 40 TO 45 KT. 52 && .PREV DISCUSSION...246 PM MDT TUE MAY 6 2014... .SYNOPSIS... THE NEXT STORM SYSTEM APPROACHING NEW MEXICO FROM THE WEST WILL DELIVER ANOTHER PUNCH OF SPRING WINDS AND BLOWING DUST WEDNESDAY. WIDESPREAD DANGEROUS FIRE WEATHER CONDITIONS WILL ACCOMPANY THE WIND AS CONDITIONS ARE EXTREMELY DRY OVER THE AREA. THE WELL ABOVE NORMAL HIGH TEMPERATURES OVER THE PAST SEVERAL DAYS WILL COOL BACK TO BELOW NORMAL FOR THE WEST WEDNESDAY...THEN ALL AREAS THURSDAY AND FRIDAY. A FEW LOCATIONS ACROSS THE NORTHERN AND WESTERN HIGH TERRAIN ALSO HAVE THE POTENTIAL FOR A COUPLE SHOWERS AND THUNDERSTORMS BOTH DAYS. TEMPERATURES WILL REBOUND AGAIN BACK NEAR TO SLIGHTLY ABOVE NORMAL FOR THE WEEKEND WITH WIDESPREAD BREEZY CONDITIONS EXPECTED. && .DISCUSSION... MSAS ANALYSIS SHOWED SURFACE LOW PRESSURE DEEPENED TO 994MB AT 19Z OVER SE COLORADO AND THE 19Z RAP INDICATES THIS WILL CONTINUE TO 989MB BY 00Z. MEANWHILE UPPER LEVEL WINDS ARE INCREASING OVER THE REGION AHEAD OF AN APPROACHING H5 UPPER LOW OVER EAST CENTRAL NV. SURFACE OBS AT KLVS HAVE BEEN NEAR OR JUST ABOVE WIND ADVISORY A COUPLE TIMES BUT SINCE ISOLD IN NATURE WILL NOT ISSUE HIGHLIGHTS. MORE SIGNIFICANT WINDS WILL ARRIVE WEDNESDAY AS THE CORE OF A 40-50KT 700-500MB JET SLIDES OVER CENTRAL/EASTERN NM. WILL PASS ALONG WIND ADVISORY HIGHLIGHTS TO OVERNIGHT CREW. ON THE QPF SIDE OF THINGS THERE ISNT MUCH TO GET EXCITED ABOUT. WPC PROBABILISTIC QPF VALUES FOR 0.10 OR MORE DO SHOW VALUES AROUND 30 PCT OVER SW FACING SLOPES OF THE NW MTS WEDNESDAY. GFS/NAM LIFTED INDICES ARE NEAR -2C FOR TMRW AFTERNOON SO THUNDER POTENTIAL STILL EXISTS. RAISED POPS INTO THE 40 AND 50 PCT RANGE BUT AMOUNTS WILL BE VERY LIGHT. ALSO TOSSED IN DUST FOR THE NW PLATEAU. MAX TEMPS WILL TREND COLDER OVER THE WEST THEN 5 TO 15F BLW NORMAL FOR ALL AREAS THURSDAY. IT WILL FEEL QUITE COOL THURSDAY WITH WIDESPREAD BREEZY CONDITIONS AND ANOTHER ROUND OF SHOWERS/ISOLD STORMS NEAR AND EAST OF HIGH TERRAIN. AGAIN QPF WILL BE VERY LIGHT. FLOW WILL RELAX SLIGHTLY AND BECOME MORE ZONAL WITH WARM ADVECTION THRU THE WEEKEND. GENERALLY CLEAR SKIES ARE EXPECTED MOST AREAS WITH THE EXCEPTION OF HIGH CLOUDS OVER THE NORTH. 700MB TEMPS WILL WARM TO NEAR +12C WHICH IS NEAR THE 75 PERCENTILE FOR MID MAY. THAT WILL TRANSLATE TO HIGHS 5 TO 15F ABV NORMAL AGAIN. MODEL CONSISTENCY AND OUTLOOK FOR NEXT WEEK IS ALMOST COMICAL SO WILL LEAVE THAT FOR LATER. GUYER && .FIRE WEATHER... WIDESPREAD RED FLAG CONDITIONS WILL CONTINUE THROUGH MID EVENING. HAVE UPGRADED ZONES 103 AND 107 TO A RED FLAG WARNING FOR WEDNESDAY LATE MORNING TO EARLY EVENING. WILL LEAVE ZONE 106 AS A WATCH AND LET THE STELLAR NIGHT CREW TAKE ONE MORE LOOK. CHANGE IN THE WEATHER IS ON THE WAY WITH COOLER TEMPERATURES AND EVENTUALLY LESS WIND...THANKS TO A POTENT COLD FRONT TOMORROW AND UPPER LEVEL DISTURBANCE. ONLY MODEST PRECIPITATION CHANCES ACROSS THE NORTH IN THE WEDNESDAY THROUGH THURSDAY TIME PERIOD. WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS TO CONTINUE THROUGH MID EVENING FOR MUCH OF NORTHERN AND CENTRAL NEW MEXICO. WINDS TO SUBSIDE DURING THE NIGHT ASIDE FROM MODERATE BREEZES OVER THE MOUNTAINS AND EAST SLOPES. WINDS WILL INCREASE QUICKLY WEDNESDAY AND BE THE STRONGEST WINDS OF THE WEEK. CRITICAL FIRE WEATHER WILL BE EASILY REACHED OVER MOST CENTRAL AND ALL EASTERN AREAS. HIGH TEMPERATURES WILL BE LOWER EVERYWHERE...BUT STILL ABOVE NORMAL IN THE FAR EAST. THIS WILL BE THE AREA WITH THE LOWEST RH VALUES WITH SINGLE DIGIT READINGS FOR ABOUT 10 HOURS. HAINES VALUES TO BE HIGH TO MODERATE. AREAS TO THE WEST ARE MORE IN THE GREY AREA AS TO HOW TO TREAT THE CRITICAL FIRE WEATHER CONDITIONS. WHILE WINDS WILL BE VERY STRONG AND HUMIDITIES BELOW 15 PERCENT FOR MANY HOURS...THE TEMPERATURES WILL BE NEAR TO BELOW NORMAL IN ZONES 103 AND 107. WITH HAINES VALUES STILL PARTLY IN THE HIGH CATEGORY IN ZONES 103 AND 10 WILL GO AHEAD AND UPGRADE THESE ZONES TO A RED FLAG WARNING FOR WEDNESDAY. WILL LEAVE ZONE 106...MIDDLE RIO GRANDE VALLEY...AS A WATCH. CERTAINLY WINDS AND HUMIDITIES WILL BE CRITICAL FOR SEVERAL HOURS...BUT LOW TO MODERATE HAINES VALUES AND HIGHS SEVERAL DEGREES BELOW NORMAL BRING A MIXED SIGNAL AS TO JUST HOW CRITICAL THIS AREA WILL BE. AS MENTIONED ABOVE WILL LET NIGHT CREW MAKE THE CALL ON ZONE 106. WILL NEED TO FACTOR IN HOW INCREDIBLY DRY IT HAS BEEN LATELY AS WELL. AS FOR CHANCE OF PRECIPITATION...ONLY THE NORTHWEST AND NORTH CENTRAL HIGHER TERRAIN COULD SEE A SHOWER OR THUNDERSTORM WEDNESDAY. MUCH COOLER AIR WILL CONTINUE TO POUR INTO THE STATE WEDNESDAY NIGHT AND THURSDAY. WINDS WILL ALSO FINALLY DIMINISH FOR MOST AREAS. IT WILL STILL BE BREEZY ACROSS THE EAST CENTRAL AREAS. A FEW RAIN AND MOUNTAIN SNOW SHOWERS WILL BE POSSIBLE ACROSS THE WEST AND NORTH BUT NO WETTING PRECIPITATION. FRIDAY SHOULD BE DRY AND MILDER WITH NEAR NORMAL TEMPERATURES AND NOT MUCH WIND. THE WEEKEND SHOULD BE MOSTLY DRY WITH THE WARMING TREND CONTINUING SATURDAY AND LEVELING OFF ON SUNDAY. AN APPROACHING BACK DOOR COLD FRONT COULD TRIGGER A SHOWER IN THE NORTHEAST AND OVER THE NORTHERN MOUNTAINS LATE SUNDAY. THE START OF NEXT WEEK WILL BE COOLER IN THE EAST. IT WILL BE DRY ASIDE FROM A NORTHERN MOUNTAIN SHOWER. THE EUROPEAN MODEL IS MORE BULLISH WITH A TROUGH AND THE PRECIPITATION POTENTIAL FOR EARLY NEXT WEEK. THEN THE GFS GOES BONKERS WITH A STRONG BACK DOOR COLD FRONT BY THE MIDDLE OF NEXT WEEK AND SIGNIFICANT PRECIPITATION IN THE EAST BEHIND THE FRONT. JUST WISHFUL THINKING AT THIS POINT. CHJ && .AVIATION... 18Z TAF CYCLE STORM OVER THE GREAT BASIN TO HEAD SLOWLY EAST. NEAR SFC WINDS STRONGER TODAY THAN MONDAY. SW WIND GUSTS OF 28-30 KTS AT FMN...ABQ...AEG AND SAF. SW WIND GUSTS OF 35-37 KTS OTHER TAF SITES. NO RESTRICTIONS TO VSBY DUE TO DUST IN ANY TAF FORECAST BUT COULD BE SOME MODEST RESTRICTIONS ARE NOT ENTIRELY OUT OF THE QUESTION...MAINLY FOR LVS...TCC AND ROW. OTHERWISE...VFR CONDITIONS ARE FORECAST TO PERSIST. STRONG WINDS AGAIN WED OVER THE E...LOWER SPEEDS IN THE WEST. 40 && .ABQ WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR THE FOLLOWING ZONES...NMZ103>109. RED FLAG WARNING FROM 10 AM TO 8 PM MDT WEDNESDAY FOR THE FOLLOWING ZONES...NMZ103-104-107-108. FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR THE FOLLOWING ZONES...NMZ106. && $$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
143 AM EDT MON MAY 5 2014 .SYNOPSIS... HIGH PRESSURE WILL BUILD DOWN FROM CANADA TODAY, BRINGING DRY AND COOL WEATHER TO NY AND PA THROUGH WEDNESDAY. A WARM FRONT WILL APPROACH FROM THE OHIO VALLEY WEDNESDAY NIGHT, BRINGING MILDER TEMPERATURES AND SCATTERED SHOWERS. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 10 PM UPDATE... A TOUCH MILDER /0-2 DEG/ ON THE EXPECTED MIN TEMPERATURES OVERNIGHT...OTHERWISE NO CHANGE FROM 730 PM UPDATE. MOST OF STRATOCUMULUS DEVELOPMENT OVERNIGHT WILL BE IN CENTRAL NY. 730 PM UPDATE... FORECAST IN GOOD SHAPE...ONLY MADE VERY MINOR ADJUSTMENTS KEEPING UP WITH LATEST OBSERVATIONS AND RADAR TRENDS. SCATTERED SPRINKLES/SHOWERS FROM DIURNAL HEATING ARE FALLING APART...EXCEPT FOR FOCUS OF SHOWERS THROUGH THIS EVENING IN THE UPPER MOHAWK VALLEY FROM OROGRAPHIC LIFT AND PROXIMITY TO DEPARTING UPPER LOW. ALSO...THOUGH DEEPER MOISTURE IS QUICK TO EXIT...925-850MB RH FIELDS IN NAM AND RUC MODELS SUGGEST STRATOCUMULUS WILL PRESS SOUTH ACROSS A GOOD CHUNK OF THE AREA OVERNIGHT BEFORE MIXING OUT MONDAY MORNING. SKY GRIDS ADJUSTED ACCORDINGLY. PREVIOUS DISCUSSION... AT 330 PM...LOCAL RADARS SHOWED SCATTERED LIGHT SHOWERS OVER NORTHEAST PENNSYLVANIA AND IN THE HIGHER TERRAIN OF CENTRAL NEW YORK. MORE WIDESPREAD ACTIVITY CONTINUES OVER NORTHERN ONIDA COUNTY. FOR TONIGHT, VERTICALLY STACKED LOW OVER NRN NEW ENGLAND WILL MOVE INTO THE CANADIAN MARITIMES. WRAP AROUND MOISTURE FROM THIS FEATURE WILL KEEP MOSTLY CLOUDY SKIES TONIGHT IN THE NRN CWA ALONG WITH SCATTERED TO WIDESPREAD SHOWERS OVER NRN ONEIDA COUNTY INTO THE LATE EVENING PERIOD. FOR THE REST OF THE REGION SKIES WILL BECOME PARTLY TO MAINLY CLEAR OVERNIGHT WITH ANY LINGERING LIGHT SHOWERS EXPECTED TO DISSIPATE BY EARLY EVENING. OVERNIGHT LOWS WILL RANGE IN THE MID TO UPPER 30S AND WITH BOUNDARY LAYER MIXING ANY FROST FORMATION IS UNLIKELY. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/... MONDAY THROUGH WEDNESDAY...SFC HIGH PRES OVER JAMES BAY WILL GRADUALLY BUILD SOUTH ACROSS THE AREA BY TUE/TUE NIGHT THEN TO THE NEW JERSEY COAST BY WEDNESDAY. DRY WEATHER IS EXPECTED THROUGH THE PERIOD ALTHOUGH BREEZY CONDITIONS ARE LIKELY BOTH MONDAY AND TUESDAY AS NORTHWEST FLOW KEEPS TEMPS ON THE COOL SIDE. BOTH MONDAY NIGHT AND TUESDAY NIGHT, WEAKER WINDS AND PARTLY TO MAINLY CLEAR CONDITIONS COULD LEAD TO SCATTERED FROST IN THE FINGER LAKES REGION AND WYOMING VALLEY WHERE THE GROWING SEASON HAS BEGUN. FROST ADVISORIES MAY BE NEEDED HERE. MAX TEMPS MON/TUE WILL RANGE FROM THE MID 50S TO AROUND 60 WITH MODERATION INTO THE LOWER TO MIDDLE 60S BY WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... 2 PM UPDATE... MEDIUM RANGE MODELS CONTINUE TO SHOW GOOD AGREEMENT THROUGH EXTENDED PERIOD. FOLLOWED WPC GUIDANCE. UNSETTLED PATTERN BUT WARMER. WARM FRONT AHEAD OF A LARGE UPPER LEVEL RIDGE. THE WARM FRONT SHOULD LIFT NORTH THROUGH THE CWA THU NGT. FRIDAY WILL BE THE WARMEST OF THE WEEK WITH 70S. A COLD FRONT QUICKLY FOLLOWS LATE FRI AND FRI NGT PROBABLY WITH THUNDERSTORMS. THE FRONT STALLS JUST TO THE EAST. DIFFERENCES FOR THE WEEKEND ON WHERE THE NEXT STORM TRACKS NE. KEPT CHC POPS BOTH DAYS BUT SATURDAY MAY END UP DRY BETWEEN THE COLD FRONT AND THE SUNDAY LOW FROM THE SW. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... 06Z UPDATE... STRATOCU HAS SPREAD INTO MOST NY TERMINALS WITH BKN VFR CIGS PREDOMINANT THOUGH AN OCCASIONAL MVFR CIG WILL BE POSSIBLE NEXT SEVERAL HOURS, ESPECIALLY AT RME, ITH AND BGM CLOSER TO DEEPER LOW LEVEL MOISTURE. SYR AND ELM WILL REMAIN VFR. POTENTIAL EXISTS FOR AVP TO SNEAK IN WITH A 3KFT CIG FROM NOW THROUGH 10Z THIS MORNING. HAVE LEFT SHOWERS OUT OF TERMINAL FORECASTS AS THEY ARE DISSIPATING RAPIDLY AND WILL NOT CAUSE ANY RESTRICTIONS. DRY AIR WORKS IN FROM ALOFT AFTER 14Z THIS MORNING WITH STRATOCU RAPIDLY MIXING OUT. SKIES WILL LIKELY CLEAR BRIEFLY BEFORE HIGH CIRRUS MOVES IN DURING THE AFTERNOON. EXPECT CIRRUS WILL BE THE MAIN STORY THROUGH 06Z TUESDAY WITH ALL TERMINALS AT VFR. WINDS FROM THE WNW WILL GUST OCCASIONALLY THROUGH THE AFTERNOON BEFORE BECOMING LIGHT THIS EVENING. OUTLOOK... LATE MON NIGHT TO WED...MAINLY VFR. WED NIGHT TO FRI...RESTRICTIONS POSSIBLE IN RAIN SHOWERS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DJP NEAR TERM...MDP/RRM SHORT TERM...RRM LONG TERM...TAC AVIATION...PVN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
103 AM EDT MON MAY 5 2014 .SYNOPSIS... A COLD FRONT WILL DROP SOUTH INTO THE AREA EARLY THIS MORNING AND MEANDER ACROSS COASTAL NORTH CAROLINA INTO WEDNESDAY. AN UPPER RIDGE WILL CONTROL AREA WEATHER THROUGH LATE WEEK. THE RIDGE WILL WEAKEN OVER THE WEEKEND AND THERE COULD BE SHOWERS IN THE AREA BY SUNDAY. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... AS OF 130 AM MONDAY...THE BACKDOOR COLD FRONT IS CURRENTLY LOCATED JUST NORTH OF HATTERAS...NEW BERN AND GREENVILLE NC...AND IS ON-TRACK TO REACH SOUTHEASTERN NC BEFORE DAYBREAK. THE 00Z NAM IS IN EXCELLENT AGREEMENT WITH THE 03Z RUC AND 02Z HRRR WITH THE TIMING AND MOVEMENT OF THIS BOUNDARY OVER THE NEXT 6-8 HOURS. OUT AHEAD OF THE FRONT A SOUTHWESTERLY LOW LEVEL JET WITH 30 KNOTS WINDS AT 1500 FEET IS KEEPING THE BOUNDARY LAYER FROM COMPLETELY DECOUPLING...BUT OTHERWISE EXCELLENT RADIATIONAL COOLING CONDITIONS (CLEAR SKIES AND DRY AIR) ARE HELPING DEEPEN THE NOCTURNAL INVERSION...ESPECIALLY INLAND FROM THE COAST. LITTLE CHANGE IS NEEDED TO THE FORECAST WITH THIS NEAR-TERM EARLY MORNING UPDATE. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...FRONT THAT DROPS INTO THE AREA TONIGHT WILL RETREAT NORTHWARD MONDAY INTO TUESDAY BEFORE DROPPING BACK INTO THE AREA TUESDAY NIGHT. AS A RESULT...WEATHER LOOKS QUIET WITH MOSTLY CLEAR SKIES AND WARM TEMPERATURES...THOUGHT THERE COULD BE A LITTLE MORE CLOUDINESS NE IN ASSOCIATION WITH THE FRONT...ESPECIALLY TUESDAY AFTERNOON AND NIGHT. MAX TEMPERATURES BOTH DAYS SHOULD REACH THE MID 80S TO AROUND 90. LOWS EACH NIGHT SHOULD FALL TO THE LOWER 60S WITH A FEW MID 50S POSSIBLE NW. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 300 PM SUNDAY...WEDNESDAY SHOULD BE THE ONE DAY OF THE PERIOD WITH TEMPS NEAR OR BELOW CLIMO AS BACKDOOR COLD FRONT LIES JUST TO OUR SOUTH. RAIN CHANCES WILL REMAIN TO OUR NORTH HOWEVER WITH BETTER NOTED SFC CONVERGENCE AND SOME WAA. WEDNESDAY NIGHT INTO THURSDAY THIS WEAKENING BOUNDARY LIFTS BACK TO OUR NORTH ALLOWING FOR A RETURN OF WARM WEATHER. THE LACK OF ANY APPRECIABLE MOISTURE ADVECTION PAIRED WITH RISING HEIGHTS WILL KEEP RAIN CHANCES OUT OF THE FORECAST FOR THE REMAINDER OF THE WORK WEEK. CHANGES MAY BEGIN ON SATURDAY AS THE 850MB RIDGE MOVES EAST OFFSHORE ALLOWING FOR DEEPER MOISTURE. AT THE SAME TIME THE CAPPING MID LEVEL RIDGE WILL MOVE OFFSHORE AND THUS IS EFFECTS LESSENED. RAIN CHANCES MAY THEN RETURN ON SUNDAY. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AS OF 06Z...EXPECT VFR TO PREVAIL THROUGH THIS TAF PERIOD. A DRY COLD FRONT WILL DIP SOUTHWARD OVERNIGHT...PASSING THROUGH KLBT/KILM AROUND 09Z AND KCRE/KFLO/KMYR AROUND 12Z. W-SW WINDS 5-10 KTS (STRONGER ALONG THE COAST OVER THE NEXT FEW HOURS WITH A HEFTY LOW-LEVEL JET) WILL VEER TO THE NORTH BEHIND THE FRONT...THEN NORTHEAST AFTER 12Z. THE FRONT WILL STALL...THEN RETREAT NORTHWARD DURING THE EARLY AFTERNOON...THOUGH THERE IS STILL SOME UNCERTAINTY ABOUT THE EXACT TIMING. THERE COULD BE A BRIEF PERIOD OF LIGHT/VRB WINDS AS THE BOUNDARY WAVERS OVERHEAD...BUT BY 18Z EXPECT SOUTHEAST WINDS 10 KTS IN A COMBINED SYNOPTIC/SEABREEZE FLOW. EXTENDED OUTLOOK...SLIGHT CHANCE OF SHOWERS LATE TUESDAY INTO EARLY WEDNESDAY. MVFR/IFR CIGS POSSIBLE WEDNESDAY AND THURSDAY MORNING. OTHERWISE VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 130 AM MONDAY...A BACKDOOR COLD FRONT IS NOSING ITS WAY DOWN THE OUTER BANKS EARLY THIS MORNING. THE FRONT IS CURRENTLY JUST NORTH OF HATTERAS BUT SHOULD ENTER THE SOUTHEASTER NORTH CAROLINA WATERS NEAR CAPE FEAR BEFORE DAYBREAK. WEST-SOUTHWEST WINDS WILL VEER TO THE NORTH...THEN NORTHEAST AFTER DAYBREAK AS THIS FRONT SLIPS INTO THE MYRTLE BEACH VICINITY BEFORE STALLING. WIND SPEEDS AROUND 15 KNOTS ARE AS HIGH AS 20 KNOTS IN SPOTS EARLY THIS MORNING...FED BY A LOW-LEVEL JET WITH 30-35 KNOT WIND SPEEDS A COUPLE THOUSAND FEET ALOFT. THIS LOW-LEVEL JET SHOULD WEAKEN AS THE FRONT APPROACHES LATE TONIGHT. SEAS RANGE FROM 2 FEET ALONG THE SC COAST TO AS HIGH AS 4 FEET EAST OF CAPE FEAR WHERE THE EFFECTIVE FETCH IS LONGEST. FEW CHANGES ARE NEEDED TO THE FORECAST WITH THIS EARLY-MORNING NEAR-TERM UPDATE. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...WEAK BACK DOOR COLD FRONT WILL WAVER NEAR THE AREA THE FIRST PART OF THE WEEK. ALTHOUGH A BRIEF PERIOD OF LIGHT NE WINDS ARE EXPECTED OVER AMZ250 EARLY MONDAY...MOST OF MONDAY AND A GOOD CHUNK OF THE DAYLIGHT HOURS TUESDAY WILL FEATURE SW WINDS OF 10-15 KTS AS HIGH PRESSURE RIDGES UP FROM THE SOUTH. LATE TUESDAY AFTN AND TUESDAY NIGHT...FRONT WILL SAG FURTHER SOUTH...CREATING A WIND SHIFT TO THE NE ACROSS ALL THE WATERS BY THE END OF THE SHORT TERM...BUT AT SPEEDS ONLY AROUND 10 KTS. SEAS WILL BE PRIMARILY DRIVEN BY A 4-6 SEC WIND WAVE...FROM THE SW MONDAY AND TUESDAY...WITH A E/NE WIND CHOP DEVELOPING TUESDAY NIGHT. THIS WILL CREATE A CONFUSED SPECTRUM LATE IN THE PERIOD...BUT SEAS WILL REMAIN MAINLY IN THE 2-3 FT RANGE WITH A FEW 4 FOOTERS POSSIBLE. LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 3 PM SUNDAY...A BACKDOOR FRONT JUST TO THE SOUTH OF THE FORECAST ZONES WILL BRING A LIGHT ONSHORE/EASTERLY FLOW. OFFSHORE FLOW TENDS TO DIMINISH THE RANGE IN WAVE HEIGHTS OFTEN OBSERVED NEARSHORE VS OFFSHORE AND THIS WILL BE THE CASE. HOWEVER OVERALL WAVE HEIGHTS WILL BE RATHER MINIMAL ANYWAY AND SO THIS EFFECT WILL BE RATHER MARGINAL. VEERING EXPECTED WEDNESDAY NIGHT AS THE BOUNDARY LIFTS TO OUR NORTH AND A SOUTHERLY FLOW COMPONENT MAKES ITS WAY NORTH ACROSS THE FORECAST ZONES. SOUTHWEST WINDS WILL REMAIN IN PLACE FOR THE REST OF THE LONG TERM. ON THURSDAY SPEED MAY BE CAPPED AT 10KT YIELDING JUST 2 FT WAVES. BOTH WIND AND SEAS MAY INCREASE FRIDAY AS THE GRADIENT TIGHTENS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RAN NEAR TERM...TRA SHORT TERM...RAN LONG TERM...MBB AVIATION...BJR/TRA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1204 AM CDT MON MAY 5 2014 .UPDATE... ISSUED AT 1204 AM CDT MON MAY 5 2014 LATEST WATER VAPOR IMAGERY AND REGIONAL RADAR DEPICT THE NEXT SHORTWAVE JUST NORTHWEST OF BILLINGS MONTANA WITH A COUPLE OF LIGHTNING STRIKES ASSOCIATED WITH IT. CURRENT BOWMAN RADAR SHOWS REFLECTIVITY`S EXTENDING TO NEAR SLOPE AND BOWMAN COUNTIES. SURFACE OBSERVATIONS SHOW MOSTLY MID LEVEL MOISTURE WITH NO EVIDENCE THAT ANYTHING IS REACHING THE GROUND TO THE IMMEDIATE WEST. THE GFS INITIALIZED WELL WITH THE LOCATION OF THIS WAVE AND MOVES IT TO NEAR DICKINSON BY 12Z MONDAY. THE HRRR AND SREF INDICATE SOME POTENTIAL FOR LIGHT QPF IN THE SOUTHWEST AND HAVE DECIDED TO ADD A SLIGHT CHC/CHC OF POPS AS THIS SHORTWAVE SCOOTS EAST OVERNIGHT. OTHERWISE PRECIPITATION OVER THE TURTLE MOUNTAINS CONTINUES TO SHIFT EAST. PLENTY OF OVERCAST CONDITIONS PER FOG/STRATUS LOOP WHICH WILL BE MAINTAINED OVERNIGHT AND BEGIN SCATTERING OUT BETWEEN 12Z AND 18Z MONDAY. UPDATE ISSUED AT 955 PM CDT SUN MAY 4 2014 RAIN AND SNOW IS CURRENTLY MOVING OUT OF NORTH CENTRAL INTO NORTHEAST NORTH DAKOTA. BACK EDGE IS MAKING ITS WAY THROUGH WESTERN BOTTINEAU COUNTY AS OF 0230 UTC. HAVE ADJUSTED POP GRIDS BASED ON LATEST RADAR IMAGERY. MAIN PRECIPITATION AREA SHOULD BE OUT OF THE NORTH CENTRAL AROUND 06-07 UTC...BUT DID KEEP SOME LINGERING SLIGHT CHANCE POPS A BIT LONGER. ALSO ADDED A MENTION OF FOG ACROSS THE FAR NORTHWEST AND NORTH CENTRAL WITH THE LATEST PRECIPITATION AND LINGERING MOISTURE IN THE LOWER ATMOSPHERE. ANOTHER WEAK IMPULSE IS CURRENTLY MOVING THROUGH SOUTH CENTRAL MONTANA. LATEST 00 UTC HRRR SEEMS TO HAVE A PRETTY GOOD HANDLE ON THIS WITH SOME LIGHT TO MODERATE INTENSITY REFLECTIVITIES SHOWING UP NORTH OF BILLINGS MT. HRRR BRINGS SOME LIGHT PRECIPITATION INTO THE FAR SOUTHWEST AROUND 07 UTC...AND THEN DISSIPATES BY AROUND 11 UTC BEFORE MAKING IT INTO THE SOUTH CENTRAL. THE RAP DID NOT INITIALIZE AS WELL BUT DOES SHOW SOME LIGHT REFLECTIVITIES THAT DRY UP BEFORE REACHING SOUTHWEST NORTH DAKOTA. WILL LEAVE IT DRY FOR NOW IN THE SOUTHWEST AND THE OVERNIGHT SHIFT CAN TAKE ANOTHER LOOK AS WE HEAD PAST MIDNIGHT. ANY PRECIPITATION HERE WOULD BE NEGLIGIBLE. UPDATE ISSUED AT 800 PM CDT SUN MAY 4 2014 QUICK UPDATE MAINLY FOR POPS AS PRECIPITATION IS RAPIDLY ENDING FROM WEST TO EAST. BACK EDGE OF MAIN PRECIPITATION BAND IS FROM AROUND SHERWOOD SOUTHWEST TO KENMARE AND STANLEY. WEST OF THIS LINE...ACCUMULATING PRECIPITATION IS OVER FOR THE EVENING. BEST AREA FOR PRECIPITATION IN THE NEXT FEW HOURS IS OVER BOTTINEAU... ROLETTE...MCHENRY AND PIERCE COUNTIES...WITH SNOW ENDING OVER RENVILLE AND WARD IN THE NEXT 1-2 HOURS. ELIMINATED THE SLIGHT CHANCE POPS ACROSS THE FAR SOUTH THIS EVENING AS TRAILING EDGE OF THIS SYSTEM IS DRY AND ANY PRECIP ALONG AND SOUTH OF I94 WILL LIKELY NOT REACH THE GROUND. ACTUALLY A BIT OF CLEARING IN THE FAR SOUTHWEST. UPDATE ISSUED AT 544 PM CDT SUN MAY 4 2014 PRECIPITATION CONTINUES TO MOVE QUICKLY EAST ACROSS NORTHWEST AND NORTH CENTRAL NORTH DAKOTA. LOOKS LIKE PREVIOUS FORECAST HAD A GOOD HANDLE ON POPS BASED ON HRRR/RAP OUTPUT. ONLY SOME MINOR TWEAKS TO POPS BASED ON LATEST RADAR. DID UPDATE TEMPERATURES WITH LOWER 30S ACROSS THE FAR NORTHWEST AND NORTH CENTRAL. HERE WILL LIKELY SEE ALL SNOW. WEATHER CAMERAS FROM RAY...PORTAL AND CARPIO INDICATE LIGHT ACCUMULATIONS ON GRASSY SURFACES. HEAVIEST PRECIPITATION AMOUNTS THROUGH EARLY EVENING LOOK WILL BE OVER THE FAR NORTH CENTRAL...ALONG THE CANADIAN BORDER. AS YOU MOVE FARTHER EAST INTO THE BOTTINEAU...ROLLA AND RUGBY AREAS...PREVIOUS INSOLATION HAS PUSHED TEMPERATURES INTO THE LOW TO MID 40S SO WE WILL LIKELY SEE A LITTLE RAIN BEFORE PRECIPITATION CHANGES TO SNOW. WITH THE BACK EDGE ALREADY MOVING INTO THE FAR NORTHWEST...THINK 1 TO 2 INCHES ON GRASSY SURFACES WILL BE THE EXTENT TO ANY ACCUMULATIONS. WILL SEND UPDATED TEXT PRODUCTS SHORTLY. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 339 PM CDT SUN MAY 4 2014 SNOWFALL POTENTIAL LATE THIS AFTERNOON AND EVENING WILL HIGHLIGHT THE SHORT TERM FORECAST. WILL FOLLOW CLOSELY TO THE 18 UTC RAP/HRRR WHOSE PREVIOUS RUNS HAVE HAD A GOOD HANDLE ON THE PRECIPITATION EXTENT AND TYPE ACROSS NORTHEAST MONTANA AND INTO FAR NORTHWEST NORTH DAKOTA THIS AFTERNOON. AS OF 20 UTC...SNOW IS BEING REPORTED FROM ESTEVAN AND CROSBY THROUGH TIOGA. AS LIFTING INCREASES ACROSS NORTHWEST AND FAR NORTH CENTRAL NORTH DAKOTA LATE THIS AFTERNOON AND EARLY EVENING...AND AIDED BY DECREASING INSOLATION...RAIN IS EXPECTED TO MIX WITH OR CHANGE TO ALL SNOW AS SURFACE TEMPERATURES DROP INTO THE 32-35 F RANGE WHICH IS CURRENTLY SUPPORTING SNOW. ONE TO TWO INCHES OF SNOW IS POSSIBLE FOR US HIGHWAY 2 AND POINTS NORTH...MOSTLY ON GRASSY SURFACES...WITH PERHAPS UP TO THREE INCHES ACROSS DIVIDE COUNTY WHICH THE RAP HAS CONSISTENTLY HIGHLIGHTED FOR THE GREATEST TOTALS IN NORTH DAKOTA. FOR NOW...HAVE AN SPS OUT TO COVER THE THREAT AND WILL MONITOR CONDITIONS CLOSELY SHOULD A WINTER WEATHER ADVISORY BECOME NECESSARY. THE PRECIPITATION BAND IS EXPECTED TO BECOME FOCUSED PRIMARILY ACROSS NORTHEAST NORTH DAKOTA AND NORTHWEST MINNESOTA AFTER 06 UTC. FOR MONDAY...A WARMER DAY IS EXPECTED WITH PLENTIFUL INSOLATION AND LOW LEVEL WARM AIR ADVECTION AHEAD OF A LEE SURFACE TROUGH WITH WIDESPREAD HIGHS IN THE 60S. DID MAINTAIN SLIGHT CHANCE POPS FOR THUNDERSTORMS GENERALLY WEST OF HIGHWAY 83 MONDAY AFTERNOON WITH 200-400 J/KG OF ML CAPE FORECAST WITH WEAK IMPULSES CRESTING THE BROAD UPPER LEVEL RIDGE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 339 PM CDT SUN MAY 4 2014 MAIN FORECAST ISSUES IN THE LONG TERM PERIOD INCLUDE PRECIPITATION TRENDS/COVERAGE/AMOUNTS THROUGH THE UPCOMING WEEK. BY MONDAY NIGHT A LARGE-SCALE LONGWAVE TROUGH IS FORECAST TO HAVE SET UP OVER THE WEST COAST...AND EMERGE INTO THE CENTRAL PART OF NORTH AMERICA BY THURSDAY- EXTENDING FROM NORTH CENTRAL CANADA TO THE SOUTHERN US PLAINS. THIS WILL BRING A PERIOD OF GOOD CHANCES OF SHOWERS AND THUNDERSTORMS TO THE REGION...WITH CHANCES OF RAIN EACH DAY AND NIGHT THROUGH THURSDAY. TOTAL RAINFALL ESTIMATES DURING THE MONDAY NIGHT THROUGH THURSDAY PERIOD RANGE FROM 1/4 INCH TO 1 1/4 INCHES OVER A WIDESPREAD AREA OF WESTERN AND CENTRAL NORTH DAKOTA. RENEWED RISES ON AREAS RIVERS ARE POSSIBLE...THESE TYPE OF AMOUNTS WOULD NOT CAUSE ANY SIGNIFICANT FLOODING ISSUES. ABUNDANT CLOUD COVER WILL HELP SUPPRESS TEMPS AND INSTABILITY...SO THE OVERALL SEVERE WEATHER THREAT THROUGH THE PERIOD IS LOW. BY FRIDAY A SEMI-PERMANENT LOW OVER NORTH CENTRAL CANADA REMAINS IN PLACE...AS THE SOUTHERN EXTENSION OF THE LARGE-SCALE TROUGH LIFTS NORTHEASTWARD THROUGH THE GREAT LAKES TOWARDS HUDSON BAY. THIS WILL LOWER THE CHANCES OF SHOWERS TO THE FORECAST AREA...AND ALLOW TEMPERATURES TO CLIMB BACK INTO THE 60S ON FRIDAY. THE CHANCES OF SHOWERS RETURN ON SATURDAY AS THE NEXT UPPER LEVEL SHORTWAVE IS FORECAST TO MOVE EAST ACROSS THE NORTHERN US ROCKIES AND INTO THE NORTH CENTRAL STATES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1204 AM CDT MON MAY 5 2014 CIGS BETWEEN 3500FT AND 4500FT AGL WILL SLOWLY RISE AND BEGIN TO SCATTER OUT BY 12Z MONDAY. THE EXCEPTION WILL BE KMOT WHERE IFR CIGS AND MVFR/IFR VSBYS WILL PERSIST UNTIL 10Z MONDAY...BEFORE CIGS IMPROVE TO MVFR. THEREAFTER...ALL TERMINALS WILL EXPERIENCE SCT/BKN VFR CIGS DURING THE DAY MONDAY. HOWEVER...THE NEXT SURGE OF SIGNIFICANT RAIN SHOWERS WILL BEGIN TO IMPINGE ACROSS THE WESTERN AERODROMES OF KISN/KDIK BETWEEN 00Z AND 06Z TUESDAY. EXPECT CIGS AND VSBYS TO BEGIN DETERIORATING MONDAY NIGHT INTO TUESDAY AS THE PRECIPITATION BECOMES WIDESPREAD OVER WESTERN AND CENTRAL NORTH DAKOTA. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KS SHORT TERM...AYD LONG TERM...JV AVIATION...KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1152 PM CDT SUN MAY 4 2014 .UPDATE... ISSUED AT 1151 PM CDT SUN MAY 4 2014 RAIN HAS DEVELOPED DOWN INTO FARGO...SO ADJUSTED HIGHER POPS A BIT FURTHER SOUTH. INCLUDED A BIT MORE SNOW MIXING IN AS WEB CAMS AND OBS HAVE SHOWN SOME FLAKES IN A FEW SPOTS IN THE NORTHWEST. THINK THAT THE BAND WILL MOVE EASTWARD OVERNIGHT AND THERE COULD BE SOME RAIN/SNOW MIX IN THE NORTHEAST TOWARDS MORNING. UPDATE ISSUED AT 952 PM CDT SUN MAY 4 2014 RAIN HAS BEEN FILLING IN ALONG THE HIGHWAY 2 CORRIDOR...FINALLY SATURATING DOWN IN THE LAST FEW HOURS. THIS TREND SHOULD CONTINUE AS MODELS SHOW THE 700MB FRONTOGENESIS INTENSIFYING OVER THE NEXT FEW HOURS OVER THE NORTHERN COUNTIES. BUMPED UP POPS INTO THE CATEGORICAL RANGE AND SPREAD THEM EASTWARD FOR THE NEXT FEW HOURS. HARVEY HAS HAD SOME SNOW ACCUMULATING ON THE GRASS JUST TO THE WEST OF OUR CWA...SO INCLUDED SOME RAIN AND SNOW MENTION IN THE FAR WESTERN COUNTIES WHERE TEMPS ARE IN THE MID 30S. DO NOT THINK WE WILL HAVE ANY ACCUMULATION BUT WILL KEEP AN EYE ON IT. UPDATE ISSUED AT 651 PM CDT SUN MAY 4 2014 RADAR RETURNS HAVE ENTERED THE NORTHWESTERN CWA ALTHOUGH THE COLUMN IS TAKING ITS SWEET TIME SATURATING AND NOT MUCH IS REACHING THE GROUND YET. WILL CONTINUE THE TREND OF LIKELY POPS SLOWLY RAMPING UP TO DEFINITE THROUGHOUT THE EVENING. TEMPS WILL SLOWLY FALL OFF INTO THE MID TO UPPER 30S. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 318 PM CDT SUN MAY 4 2014 LATEST RADAR IMAGE FROM KMBX (MINOT...ND) IS SHOWING MID LEVEL MOISTURE CURRENTLY SPREADING ACROSS SOURIS RIVER BASIN...HOWEVER GROUND TRUTH AS FAR AS PRECIP REPORTS IS FURTHER WEST...ROUGHLY ALONG A WILLISTON TO ESTEVAN (SASK) LINE. HAVE BEEN GOING WITH A RUC/NAM SOLUTION...PRIMARILY USING RUC AS GUIDANCE THROUGH 09Z THEN TRENDING TOWARD NAM FOR MONDAY. TONIGHT...A VORT MAX EMBEDDED IN ZONAL UPPER LEVEL FLOR...CURRENTLY OVER NORTHWESTERN ND...WILL MOVE ACROSS THE STATE AND INTO W CNTRL MN TONIGHT. WEAK ADIABATIC OMEGA AND H700 FG FORCING WILL PROVIDE SOME FORCING TO GENERATE SHOWERS AS THE VORT MAX MOVES ACROSS THE STATE. CIGS HAVE DROPPED DOWN TO 4K FT IN PORTIONS OF NW ND...GIVING MORE CONFIDENCE RAIN WILL MAKE IT TO THE SFC. OVERALL...HOWEVER...MODELS APPEAR A BIT BULLISH ON MOISTURE AND EXPECTING ONLY TEN TO TWENTY HUNDREDTHS OVER DVL BASIN. DO HAVE CATEGORICAL POPS OVER THIS REGION WITH LIKELIES IN THE NORTH CENTRAL VALLEY...TAPERING OFF TO HIGH CHANCE POPS AS ACTIVITY GETS TO THE EASTERN ZONES...MAINLY DUE TO LESS CONFIDENCE ON TIMING. BY 12Z...NAM SHOWING DOWNWARD VERTICAL MOTION ACROSS MAJORITY OF AREA AND DRYING THINGS UP SHORTLY AFT 12Z. AGAIN...HAVE USED RUC AS GUIDANCE FOR HOURLY POPS THROUGH 09Z WITH NAM FOR THE 09Z TO 12Z TIMEFRAME...THEN DRY ON MONDAY. ONE CAVEAT...RUC DOES HOLD ON TO SHOWERS IN THE NORTHWESTERN ZONES...AND TRENDED TOWARD A DRIER SOLUTION IN THIS AREA (MORE IN LINE WITH NAM). OVERNIGHT LOWS IN THE NORTHWEST AND NORTHEAST WILL BE IN THE LOWER 30S AND DID MENTION SNOW FOR THESE AREAS BUT NO ACCUMULATION EXPECTED IF THERE IS A CHANGE OVER BEFORE SHOWERS MOVE OUT OF AREA. MONDAY AND MONDAY NIGHT...BROAD WEAK RIDGING ALOFT WILL KEEP MONDAY DRY. RETURN FLOW WILL INCREASE THROUGHOUT THE DAY AND INCREASED SOLAR WILL ALLOW TEMP TO CLING INTO THE MID 50S TO MID 60S...WITH WARMEST TEMPS ACROSS SOUTHEASTERN ND. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 318 PM CDT SUN MAY 4 2014 MONDAY NIGHT THROUGH TUESDAY NIGHT...UPPER RIDGE WILL SHIFT EAST AND SW FLOW PATTERN WILL SET UP ALOFT...WITH A WAVE DEVELOPING AND EJECTING OUT OF CNTRL ROCKIES EARLY TUES MORNING. PRECIP WILL DEVELOP OVER WRN DAKOTAS TUE MORNING. SFC LOW OVER SOUTHERN PLAINS WILL STRENGTHEN AND HELP PUMP GULF MOISTURE UP INTO EASTERN DAKOTAS. 12Z GFS SHOWING INCREASING H850 MOISTURE FLUX INTO CNTRL DAKOTAS...WITH PWATS REACHING AROUND ONE INCH BY 18Z. GFS ALSO SHOWS BAND OF MID LEVEL FRONTOGENESIS FORMING MID DAY TUESDAY. WILL KEEP INHERITED LIKELIES IN FOR TUESDAY. ECMWF AND GFS IN DECENT AGREEMENT WITH MOST PRECIP FALLING ALONG AND NORTH OF HIGHWAY 200 CORRIDOR...WITH NAM FOCUSING ON DVL BASIN...WHICH IS WHERE I WILL LIMIT LIKELIES FOR TUE AFTN. CURRENT QPF VALUES APPROACHING ONE HALF INCH FOR PORTIONS OF N CNTRL ND...BUT PLENTY OF TIME TO WORK OUT THOSE DETAILS. WED...INVERTED TROUGH SHIFTS OFF TO EAST DURING DAY WED...WITH NORTH TO NORTHEAST FLOW SETTING UP. SHOULD SEE PORTIONS OF THE NORTHWESTERN CWA DRY UP...HOWEVER MODELS ALL OVER THE PLACE WITH MOISTURE FOR WEDNESDAY. GENERALLY LIKE THE GFS SOLUTION OF DRYING OUT THE DVL LAKE BASIN...BUT THE ECMWF CONTINUES RATHER BULLISH MOISTURE OVER THE AREA AND EVEN THE NAM SHOWS SOME POPS OVER THE AREA. INHERITED CHANCE POPS THEREFORE SEEMS REASONABLE...SUPPORTED BY CONSALL..AND NOT ENOUGH CONFIDENCE AT THIS POINT TO TRY AND TIME CLEARING FOR WED AFTN. WED NIGHT THROUGH SUNDAY...ACTIVE ZONAL/SW FLOW ALOFT DEPICTED BY ALL THE MODELS. THE MAIN CHALLENGE WILL BE TIMING OF INDIVIDUAL WAVES WITHIN THIS FLOW. THE BEST CONSENSUS FOR HIGHER SHOWER CHANCES APPEARS TO BE WED NIGHT INTO THUR NIGHT...AND THEN AGAIN ON SATURDAY. DURING THIS ENTIRE PERIOD...IT APPEARS THAT 1-2 INCHES OF RAINFALL IS PROBABLE. TEMPERATURES WILL BE DEPENDENT ON CLOUDS COVER AND ACTUAL TIMING OF SHOWERS...BUT GENERALLY NEAR OR SLIGHTLY BELOW NORMAL VALUES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1151 PM CDT SUN MAY 4 2014 MVFR CIGS HAVE DEVELOPED OVER KGFK AND KTVF...AND KDVL HAS GONE ALL THE WAY DOWN TO 500 FT. WILL CONTINUE TO KEEP RESTRICTIONS IN THOSE AREAS THROUGHOUT THE TIME PERIOD FROM 06 TO 12Z WHERE WE ARE EXPECTING RAIN...SPREADING INTO KBJI LATER TONIGHT. KFAR IS EXPECTED TO STAY VFR...BUT WILL HAVE TO BE WATCHED AS THEY TOOK A BRIEF DIP TO MVFR AND WENT BACK UP. THINK THAT LOWER CIGS WILL REMAIN FOR A BIT LONGER IN THE EARLY MORNING AFTER THE RAIN HAS TAPERED OFF...BUT CONDITIONS SHOULD BE ALL VFR BY MID MORNING. EAST WINDS WILL CONTINUE AT BELOW 12 KTS. && .HYDROLOGY... ISSUED AT 108 PM CDT SAT MAY 3 2014 TRIBUTARIES INTO THE MAINSTEM RED CONTINUE TO SEE FALLING STAGES. THE RED RIVER AT FARGO IS FORECAST TO FALL BELOW MODERATE FLOOD STAGE OVERNIGHT TONIGHT. FARTHER NORTH...A BROAD FLAT CREST HAS OCCURRED ACROSS CENTRAL INTO NORTHERN SECTIONS OF THE RED. A VERY GRADUAL RECESSION IN STAGES IS FORECAST FROM EAST GRAND FORKS TO OSLO...WITH SOME GRADUAL RISES ANTICIPATED TO CONTINUE FROM DRAYTON NORTHWARD TO PEMBINA BELOW FLOOD STAGE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...JR SHORT TERM...SPEICHER LONG TERM...TG/SPEICHER AVIATION...JR HYDROLOGY...MAKOWSKI
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
739 PM EDT TUE MAY 6 2014 .SYNOPSIS... A WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA TONIGHT INTO WEDNESDAY. A COLD FRONT WILL MOVE ACROSS THE REGION FRIDAY NIGHT INTO SATURDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... QUIET WEATHER THIS EVENING WITH VASTLY DIFFERENT TEMPERATURES ACROSS THE AREA. TEMPERATURES IN THE MIDDLE TO UPPER 50S NEAR THE LAKE SHORE VERSUS 70 DEGREES ACROSS THE SOUTHERN TIER COUNTIES ALL THANKS TO LAKE ERIE. LATEST HRRR MODEL IS JUST NOW COMING IN AND IT INDICATES SOME SHOWER ACTIVITY ACROSS THE FORECAST AREA FROM ABOUT 08Z UNTIL 13Z TO 14Z. THIS IS IN LINE WITH CURRENT FORECAST SO WILL NOT MAKE ANY ADJUSTMENTS. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/... THE WARM FRONT WILL MAKE SLOW NORTHEASTWARD PROGRESS THROUGH WEDNESDAY AFTERNOON. MODELS ARE INDICATING A BIT OF LOW LEVEL INSTABILITY DEVELOPING ALONG THE WARM FRONT...ESPECIALLY ACROSS THE EASTERN PORTION OF THE COUNTY WARNING AREA. IF THIS DOES OCCUR A FEW OF THE THUNDERSTORMS COULD BE ON THE STRONG SIDE. LOW LEVEL MOISTURE WILL BE HIGHER ALONG WITH THE STRONGER WARM ADVECTION AS THE FRONT LIFTS ACROSS THE NORTHEAST PORTION OF THE COUNTY WARNING AREA. SO THAT SHOULD LEAD TO HIGHER CHANCES OF SHOWERS AND THUNDERSTORMS. INCREASED UPPER LEVEL RIDGING AND THE LIKELIHOOD OF A MIDDLE LEVEL CAP SHOULD ALLOW FOR A PARTLY CLOUDY AND HOT DAY. HIGHS THURSDAY AFTERNOON SHOULD BE ABLE TO WARM WELL INTO THE 80S. COOLER ON FRIDAY WITH INCREASED CLOUD COVER BUT IT WILL NOT PROBABLY ONLY 5 TO 8 DEGREES COOLER. JET ENERGY AND THE COLD FRONT SHOULD REMAIN WEST OF THE REGION ON FRIDAY SO THE THREAT OF THUNDER WILL LIKELY HINGE ON THE LOCATIONS OF ANY OUTFLOW FROM THURSDAY NIGHTS CONVECTION ACROSS ILLINOIS INTO INDIANA. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AN ACTIVE WEATHER PATTERN IS EXPECTED DURING THE EXTENDED PORTION OF THE FORECAST. THE MOISTURE AXIS WILL REMAINS OVERHEAD ON SATURDAY AND EXPECT ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS AS A TROUGH LIFTS OUT OF THE PLAINS. THIS SYSTEM WAS SUPPOSED TO PUSH A COLD FRONT SOUTH ACROSS THE AREA BUT NOW IT LOOKS LIKE IT MAY STALL ACROSS NRN OHIO THROUGH THE WEEKEND. IT BECOMES HARDER TO TIME OPPORTUNITIES FOR SHOWERS AND THUNDERSTORMS INTO EARLY NEXT WEEK THEN AS THIS BOUNDARY AND SOME RESIDUAL MOISTURE REMAIN IN PLACE. THE GFS IS MORE PROGRESSIVE THAN THE ECMWF AND CMC THROUGH MONDAY. THE OTHER MODELS ARE OFFERING A MORE CONSISTENT SOLUTION WITH EACH OTHER AND PREVIOUS RUNS SO LEANED THE FORECAST IN THAT DIRECTION. THE FORECAST IS RATHER VAGUE WITH A CHANCE OF SHOWERS AND THUNDERSTORMS MOST DAYS AND TEMPERATURES JUST SLIGHTLY ABOVE NORMAL. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... A WARM FRONT OVER THE OHIO VALLEY WITH STRENGTHEN AS IT BEGINS TO MOVE NORTH LATE TONIGHT AND WEDNESDAY. THE FRONT MAY NOT MAKE IT TO LAKE ERIE BY WEDNESDAY LATE AFTERNOON. EXPECT A FEW SHOWERS AND PERHAPS A THUNDERSTORM TO DEVELOP. VFR CONDITIONS WILL PERSIST EXCEPT UNDER A FEW OF THE HEAVIER SHOWERS. WINDS WILL SHIFT FROM EAST TO SOUTH FOLLOWING THE FRONTAL PASSAGE. .OUTLOOK...NON VFR AT TIMES DEVELOPING FRIDAY AND CONTINUING INTO SUNDAY MORNING IN SHOWERS AND THUNDERSTORMS. && .MARINE... HIGH PRESSURE OVER THE CENTRAL GREAT LAKES WILL SHIFT TO NEW ENGLAND OVERNIGHT. A WARM FRONT LOCATED NEAR THE OHIO VALLEY WILL LIFT NORTH OVERNIGHT CAUSING EASTERLY WINDS TO INCREASE TO 10 TO 20 KNOTS ON THE WESTERN HALF OF THE LAKE. THIS WILL CAUSE WAVES TO BUILD TO 1 TO 4 FEET FOR A PERIOD OF TIME LATE TONIGHT INTO WEDNESDAY BEFORE THE FLOW SHIFTS TO SOUTHEASTERLY AND THE HIGHEST WAVES SHIFT TOWARDS THE NORTH SHORE. THERE IS A LOW CHANCE OF NEEDING A SMALL CRAFT ADVISORY IF WINDS END UP BEING STRONGER OR THE FRONT IS SLOWER TO SHIFT NORTH. WINDS WILL SHIFT TO THE SOUTH ON THURSDAY WITH THE PASSAGE OF THE WARM FRONT WITH STABLE CONDITIONS AND WAVES DECREASING TO 2 FEET OR LESS. AN ACTIVE WEATHER PATTERN WITH OCCASIONAL SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH SATURDAY...WITH LOWER CHANCES OF SHOWERS AND THUNDERSTORMS CONTINUING INTO NEXT WEEK. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...MULLEN NEAR TERM...LOMBARDY SHORT TERM...MULLEN LONG TERM...KEC AVIATION...KOSARIK MARINE...KEC
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
425 PM EDT MON MAY 5 2014 .SYNOPSIS... STATIONARY FRONT REMAINS ACROSS THE SOUTHERN COAL FIELDS TONIGHT AND TUESDAY...BEFORE LIFTING NORTH AS A WARM FRONT ON WEDNESDAY. SUMMER PREVIEW THURSDAY INTO FRIDAY. MOISTURE INCREASES LATE FRIDAY. && .NEAR TERM /THROUGH TUESDAY/... ELEVATED CONVECTION THAT MOVED THROUGH OHIO OVERNIGHT AND CENTRAL WV LOWLANDS THIS MORNING IS CURRENTLY MOVING ESE WITH SOME LIGHTNING BEING PICKED UP IN THE VICINITY OF THE WV/VA BORDER NEAR SOUTHERN POCAHONTAS CO...DOWNPLAYED THUNDERSTORM COVERAGE AS DEWPTS IN OBS REMAINED WELL BELOW MODEL GUIDANCE WITH NAM OVER DOING MOISTURE ADVECTION SO WENT WITH DRIER RUC SOLUTION THROUGH THE AFTERNOON INTO THE EVENING...SOUTHERN PORTION OF WEAK UPPER LEVEL SHORTWAVE MOVES ACROSS THE STATIONARY BOUNDARY ACROSS EASTERN KENTUCKY AND THE CENTRAL WV LOWLANDS IN THE PREDAWN HOURS PRODUCING JUST ENOUGH LIFT TO TRIGGER A CHANCE OF SCATTERED SHOWERS BUT OTHERWISE SHOULD RESULT IN MOSTLY CLOUDY SKIES BEFORE CLEARING AFTER SUNRISE...WARM AIR WILL SLOWLY PROGRESS NORTHWARD WITH MOST OF THE CWA REACHING THE LOW TO MID 70`S AND OUR EXTREME SOUTHERN COUNTIES NEARING 80. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... THE WARM FRONT WILL SLOWLY EXIT NORTH OF THE AREA TUESDAY NIGHT INTO WEDNESDAY TAKING THE RAIN SHOWERS WITH IT. A BRIEF HIGH PRESSURE TAKES CONTROL LATE WEDNESDAY THROUGH THURSDAY. A LOW PRESSURE SYSTEM MOVES NORTHEAST OUT OF THE PLAINS...BY MID WEEK...SETTING DEEP SOUTHWESTERLY FLOW. WITH MOSTLY SUNNY SKIES COURTESY OF THE SURFACE HIGH PRESSURE...MUCH WARMER AIR IS EXPECTED WEDNESDAY AND THURSDAY. TEMPERATURES COULD REACH INTO THE UPPER 80S OR PERHAPS REACH 90 DEGREES...THE WARMEST WEATHER SO FAR THIS YEAR FOR MOST LOCATIONS. ADJUSTED POPS A BIT AS WELL AS TEMPERATURES. WENT GENERALLY WITH THE CONSENSUS NUMBERS THROUGH THE PERIOD. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... THE SUMMER PREVIEW WILL BE AIRING ON THE START FOR THURSDAY EVENING. WE WERE A BIT SLOWER MOVING THE DEEPER MOISTURE EAST FRIDAY AFTERNOON AND FRIDAY NIGHT...THUS A BIT SLOWER ON INCREASING POPS...AND A BIT HIGHER ON MAXIMUM TEMPERATURES IN THE CRW-CKB CORRIDOR ON EAST ON FRIDAY. PROBABLY ENOUGH CLOUDS TO HOLD TEMPERATURES DOWN A BIT. 500 MB HEIGHTS ONLY DROPPING SLOWLY FRIDAY...AS INITIAL ENERGY WITH NORTHERN BRANCH LIFTS THROUGH GREAT LAKES INTO ONTARIO. 500 MB DISTURBANCES LIFTING OUT OF THE SOUTHERN MISSISSIPPI VALLEY PASS BY OUR VICINITY BY 12Z SUNDAY. SO HIGHEST POPS ARE ON SATURDAY INTO SATURDAY NIGHT. STILL TRIED TO HOLD MAXIMUM TEMPERATURES BELOW GUIDANCE WITH CLOUDS AND PCPN. THE MID/UPPER RIDGE HOLDS OVER THE SOUTHEAST...SO THE FRONT NEVER CLEARS THE UPPER OHIO VALLEY OVER THE WEEKEND. THE 12Z ECWMF BUILDS BACK RIDGE STRONGER THAN THE 12Z GFS FOR DAY 7/MONDAY. THE 12Z MODELS AGREE THAT THE DEEPER MOISTURE GET SHUNTED TO OUR EAST BY MOTHERS DAY. HOWEVER...IF FRONT NEVER CLEARS...STILL VULNERABLE TO ANY WEAKER DISTURBANCES IN THE LEFTOVER INSTABILITY. I TRENDED TOWARD LOWER CHANCE AND SLIGHT CHANCE POPS ON SUNDAY INTO MONDAY AND SLIGHTER WARMER MAXIMUM TEMPERATURES. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... SHOWERS AND A FEW ISOLATED THUNDERSTORMS ASSOCIATED WITH STATIONARY FRONT JUST SOUTH OF HTS AND CRW EXTENDING DUE EAST/WEST EXHIBITING RELATIVELY STRONG THERMAL GRADIENT...DECREASED EXTENT OF THUNDERSTORM COVERAGE FROM PREVIOUS FORECAST DUE TO LOWER DEWPTS ACROSS SOUTHERN THIRD OF THE STATE AND CLOUD COVER FROM ELEVATED CONVECTION THROUGH THE CENTRAL LOWLANDS OF WV THIS MORNING KEPT CLOUD COVER AREA WIDE INTO THE AFTERNOON...VFR WILL PERSIST THROUGH THE PERIOD AS SHOWERS MOVE E WITH A CHANCE OF MVFR IN ANY HEAVIER SHOWERS...LINGERING EARLY MORNING MOISTURE WILL PRODUCE SOME LOW CLOUDS DURING OVERNIGHT WITH CLEARING AFTER SUNRISE ON TUESDAY. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY... FORECAST CONFIDENCE: MEDIUM TO HIGH. ALTERNATE SCENARIOS: THERE MAY BE MORE MVFR IN SHRA / TSRA THIS PERIOD...WITH IFR ALSO POSSIBLE. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H M M EKN CONSISTENCY M M M M H H H H H H M M PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY M M H H H H H H H H H H AFTER 18Z TUESDAY... IFR POSSIBLE IN RAIN SHOWERS SATURDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/ARJ/JM NEAR TERM...JM SHORT TERM...ARJ LONG TERM...KTB AVIATION...KTB/JM/LS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
304 PM EDT MON MAY 5 2014 .SYNOPSIS... STATIONARY FRONT REMAINS ACROSS THE SOUTHERN COAL FIELDS TONIGHT AND TUESDAY...BEFORE LIFTING NORTH AS A WARM FRONT ON WEDNESDAY. SUMMER PREVIEW THURSDAY INTO FRIDAY. COLD FRONT CROSSES SATURDAY. && .NEAR TERM /THROUGH TUESDAY/... ELEVATED CONVECTION THAT MOVED THROUGH OHIO OVERNIGHT AND CENTRAL WV LOWLANDS THIS MORNING IS CURRENTLY MOVING ESE WITH SOME LIGHTNING BEING PICKED UP IN THE VICINITY OF THE WV/VA BORDER NEAR SOUTHERN POCAHONTAS CO...DOWNPLAYED THUNDERSTORM COVERAGE AS DEWPTS IN OBS REMAINED WELL BELOW MODEL GUIDANCE WITH NAM OVER DOING MOISTURE ADVECTION SO WENT WITH DRIER RUC SOLUTION THROUGH THE AFTERNOON INTO THE EVENING...SOUTHERN PORTION OF WEAK UPPER LEVEL SHORTWAVE MOVES ACROSS THE STATIONARY BOUNDARY ACROSS EASTERN KENTUCKY AND THE CENTRAL WV LOWLANDS IN THE PREDAWN HOURS PRODUCING JUST ENOUGH LIFT TO TRIGGER A CHANCE OF SCATTERED SHOWERS BUT OTHERWISE SHOULD RESULT IN MOSTLY CLOUDY SKIES BEFORE CLEARING AFTER SUNRISE...WARM AIR WILL SLOWLY PROGRESS NORTHWARD WITH MOST OF THE CWA REACHING THE LOW TO MID 70`S AND OUR EXTREME SOUTHERN COUNTIES NEARING 80. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... THE WARM FRONT WILL SLOWLY EXIT NORTH OF THE AREA TUESDAY NIGHT INTO WEDNESDAY TAKING THE RAIN SHOWERS WITH IT. A BRIEF HIGH PRESSURE TAKES CONTROL LATE WEDNESDAY THROUGH THURSDAY. A LOW PRESSURE SYSTEM MOVES NORTHEAST OUT OF THE PLAINS...BY MID WEEK...SETTING DEEP SOUTHWESTERLY FLOW. WITH MOSTLY SUNNY SKIES COURTESY OF THE SURFACE HIGH PRESSURE...MUCH WARMER AIR IS EXPECTED WEDNESDAY AND THURSDAY. TEMPERATURES COULD REACH INTO THE UPPER 80S OR PERHAPS REACH 90 DEGREES...THE WARMEST WEATHER SO FAR THIS YEAR FOR MOST LOCATIONS. ADJUSTED POPS A BIT AS WELL AS TEMPERATURES. WENT GENERALLY WITH THE CONSENSUS NUMBERS THROUGH THE PERIOD. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... BASING FORECAST ON WARM FRONT EXITING WEDNESDAY EVENING. NEXT FRONT FROM THE NORTHERN STREAM APPROACHES FRIDAY NIGHT. YET...AS THAT 500 MB TROF LIFTS NORTHEAST THROUGH GREAT LAKES AND INTO ONTARIO...EXPECTED FRONTAL BOUNDARY TO STALL OUT IN OHIO VALLEY FOR SATURDAY INTO SUNDAY. 500 MB TROF IN SOUTHERN STREAM APPEARS TO LIFT NORTHEAST THROUGH OUR VICINITY SUNDAY AFTERNOON. SO AFTER A PREVIEW OF SUMMER ON THURSDAY AND THURSDAY EVENING... HAVE POPS INCREASING DURING FRIDAY INTO FRIDAY EVENING WITH THE INITIAL APPROACH OF THE MIDWESTERN FRONT. NOT OVERLY EXCITED ABOUT SEVERE POTENTIAL HERE LATE FRIDAY WITH THAT ENERGY LIFTING NORTH. THEN EXPECT ROUNDS OF SHOWERS/THUNDERSTORMS OVER THE MOTHERS DAY WEEKEND. STILL THINK WE CAN KEEP MAXIMUM TEMPERATURES A BIT LOWER ON SATURDAY AND SUNDAY THAN GUIDANCE...COUNTING ON NO LARGE INTERVALS OF CLEARING. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... SHOWERS AND A FEW ISOLATED THUNDERSTORMS ASSOCIATED WITH STATIONARY FRONT JUST SOUTH OF HTS AND CRW EXTENDING DUE EAST/WEST EXHIBITING RELATIVELY STRONG THERMAL GRADIENT...DECREASED EXTENT OF THUNDERSTORM COVERAGE FROM PREVIOUS FORECAST DUE TO LOWER DEWPTS ACROSS SOUTHERN THIRD OF THE STATE AND CLOUD COVER FROM ELEVATED CONVECTION THROUGH THE CENTRAL LOWLANDS OF WV THIS MORNING KEPT CLOUD COVER AREA WIDE INTO THE AFTERNOON...VFR WILL PERSIST THROUGH THE PERIOD AS SHOWERS MOVE E WITH A CHANCE OF MVFR IN ANY HEAVIER SHOWERS...LINGERING EARLY MORNING MOISTURE WILL PRODUCE SOME LOW CLOUDS DURING OVERNIGHT WITH CLEARING AFTER SUNRISE ON TUESDAY. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY... FORECAST CONFIDENCE: MEDIUM TO HIGH. ALTERNATE SCENARIOS: THERE MAY BE MORE MVFR IN SHRA / TSRA THIS PERIOD...WITH IFR ALSO POSSIBLE. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY M H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY M H H H H H H H H H H H EKN CONSISTENCY M L L L L M H M H H H H PKB CONSISTENCY M M H H H H H H H H H H CKB CONSISTENCY M M M M M H H H H H H H AFTER 18Z TUESDAY... NO WIDESPREAD IFR EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/ARJ/JM NEAR TERM...JM SHORT TERM...ARJ LONG TERM...KTB AVIATION...JM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
234 PM EDT MON MAY 5 2014 .SYNOPSIS... STATIONARY FRONT REMAINS ACROSS THE SOUTHERN COAL FIELDS TONIGHT AND TUESDAY...BEFORE LIFTING NORTH AS A WARM FRONT ON WEDNESDAY. SUMMER PREVIEW THURSDAY INTO FRIDAY. COLD FRONT CROSSES SATURDAY. && .NEAR TERM /THROUGH TUESDAY/... ELEVATED CONVECTION THAT MOVED THROUGH OHIO OVERNIGHT AND CENTRAL WV LOWLANDS THIS MORNING IS CURRENTLY MOVING ESE WITH SOME LIGHTNING BEING PICKED UP IN THE VICINITY OF THE WV/VA BORDER NEAR SOUTHERN POCAHONTAS CO...DOWNPLAYED THUNDERSTORM COVERAGE AS DEWPTS IN OBS REMAINED WELL BELOW MODEL GUIDANCE WITH NAM OVER DOING MOISTURE ADVECTION SO WENT WITH DRIER RUC SOLUTION THROUGH THE AFTERNOON INTO THE EVENING...SOUTHERN PORTION OF WEAK UPPER LEVEL SHORTWAVE MOVES ACROSS THE STATIONARY BOUNDARY ACROSS EASTERN KENTUCKY AND THE CENTRAL WV LOWLANDS IN THE PREDAWN HOURS PRODUCING JUST ENOUGH LIFT TO TRIGGER A CHANCE OF SCATTERED SHOWERS BUT OTHERWISE SHOULD RESULT IN MOSTLY CLOUDY SKIES BEFORE CLEARING AFTER SUNRISE...WARM AIR WILL SLOWLY PROGRESS NORTHWARD WITH MOST OF THE CWA REACHING THE LOW TO MID 70`S AND OUR EXTREME SOUTHERN COUNTIES NEARING 80. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... PERIOD STARTS OUT WITH SHOWERS TAPERING OFF AS WAVE MONDAY NIGHT EXITS TO THE EAST. MUCH OF THE DAY TUESDAY SHOULD REMAIN RELATIVELY QUIET...HOWEVER...WILL BE INCHING TOWARDS A MUCH WARMER...AND MORE HUMID PERIOD. STALLED FRONTAL BOUNDARY WILL LIFT NORTH ON WEDNESDAY...AS LOW PRESSURE MOVES NORTHEAST OUT OF THE PLAINS...WITH BUILDING UPPER HEIGHTS ACROSS THE AREA AS ASSOCIATED UPPER TROUGH DEEPENS ACROSS THE CENTER OF THE COUNTRY. MUCH WARMER AIR AS OF LATE WILL MOVE INTO THE AREA. IN FACT...THIS WILL PROBABLY BE THE WARMEST WEATHER SO FAR THIS YEAR FOR MOST LOCATIONS. BEST CHANCE FOR PRECIPITATION ON WEDNESDAY WILL BE ACROSS THE NORTH AS A DISTURBANCE RIDES OVER THE TOP OF THE RIDGE. RAISED MAX TEMPERATURES SEVERAL DEGREES ON WEDNESDAY FROM PREVIOUS FORECAST. && .LONG TERM /THURSDAY THROUGH MONDAY/... BASING FORECAST ON WARM FRONT EXITING WEDNESDAY EVENING. NEXT FRONT FROM THE NORTHERN STREAM APPROACHES FRIDAY NIGHT. YET...AS THAT 500 MB TROF LIFTS NORTHEAST THROUGH GREAT LAKES AND INTO ONTARIO...EXPECTED FRONTAL BOUNDARY TO STALL OUT IN OHIO VALLEY FOR SATURDAY INTO SUNDAY. 500 MB TROF IN SOUTHERN STREAM APPEARS TO LIFT NORTHEAST THROUGH OUR VICINITY SUNDAY AFTERNOON. SO AFTER A PREVIEW OF SUMMER ON THURSDAY AND THURSDAY EVENING... HAVE POPS INCREASING DURING FRIDAY INTO FRIDAY EVENING WITH THE INITIAL APPROACH OF THE MIDWESTERN FRONT. NOT OVERLY EXCITED ABOUT SEVERE POTENTIAL HERE LATE FRIDAY WITH THAT ENERGY LIFTING NORTH. THEN EXPECT ROUNDS OF SHOWERS/THUNDERSTORMS OVER THE MOTHERS DAY WEEKEND. STILL THINK WE CAN KEEP MAXIMUM TEMPERATURES A BIT LOWER ON SATURDAY AND SUNDAY THAN GUIDANCE...COUNTING ON NO LARGE INTERVALS OF CLEARING. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... SHOWERS AND A FEW ISOLATED THUNDERSTORMS ASSOCIATED WITH STATIONARY FRONT JUST SOUTH OF HTS AND CRW EXTENDING DUE EAST/WEST EXHIBITING RELATIVELY STRONG THERMAL GRADIENT...DECREASED EXTENT OF THUNDERSTORM COVERAGE FROM PREVIOUS FORECAST DUE TO LOWER DEWPTS ACROSS SOUTHERN THIRD OF THE STATE AND CLOUD COVER FROM ELEVATED CONVECTION THROUGH THE CENTRAL LOWLANDS OF WV THIS MORNING KEPT CLOUD COVER AREA WIDE INTO THE AFTERNOON...VFR WILL PERSIST THROUGH THE PERIOD AS SHOWERS MOVE E WITH A CHANCE OF MVFR IN ANY HEAVIER SHOWERS...LINGERING EARLY MORNING MOISTURE WILL PRODUCE SOME LOW CLOUDS DURING OVERNIGHT WITH CLEARING AFTER SUNRISE ON TUESDAY. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY... FORECAST CONFIDENCE: MEDIUM TO HIGH. ALTERNATE SCENARIOS: THERE MAY BE MORE MVFR IN SHRA / TSRA THIS PERIOD...WITH IFR ALSO POSSIBLE. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY M H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY M H H H H H H H H H H H EKN CONSISTENCY M L L L L M H M H H H H PKB CONSISTENCY M M H H H H H H H H H H CKB CONSISTENCY M M M M M H H H H H H H AFTER 18Z TUESDAY... NO WIDESPREAD IFR EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/ARJ/JM NEAR TERM...JM SHORT TERM...SL LONG TERM...KTB AVIATION...JM
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
639 AM EDT MON MAY 5 2014 .SYNOPSIS... AN EMBEDDED DISTURBANCE WITHIN A NORTHWEST FLOW ALOFT WILL BRING A THREAT FOR SHOWERS AND THUNDERSTORMS TO PARTS OF THE REGION TODAY. AT THE SAME TIME...A FRONTAL BOUNDARY LOCATED TO OUR SOUTHWEST WILL NUDGE A LITTLE FARTHER NORTHEAST THIS AFTERNOON. THE PROXIMITY OF THIS FRONT WILL RESULT IN A WIDE RANGE OF HIGH TEMPERATURES. FOR TONIGHT INTO TUESDAY...SURFACE HIGH PRESSURE ACROSS THE GREAT LAKES WILL PUSH THE FRONT JUST SOUTH OF OUR AREA ONCE AGAIN. THE FRONT WILL THEN RETURN NORTHEAST AS A WARM FRONT TUESDAY NIGHT INTO WEDNESDAY. TEMPERATURES WILL WARM APPRECIABLY ALL AREAS IN THE WAKE OF THE WARM FRONT WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... BASED ON LATEST RADAR TRENDS AND THE HRRR MODEL...WILL TRANSLATE LIKELY POPS TO THE NRN/NERN CWFA THIS MORNING WITH DECREASING CHANCES HEADING TOWARD THE SW CWFA. HIGHER POPS ARE BEING EMPLOYED N AND NE IN RESPONSE TO AN APPROACHING S/WV IN THE NW FLOW ALOFT. IT NOW LOOKS LIKE ELEVATED INSTABILITY WILL WEAKEN AS IT HEADS EAST SO HAVE LOWERED THE THREAT OF THUNDER TO SLIGHT CHANCE. BY THIS AFTERNOON...WE SHOULD SEE A MINIMUM IN PCPN COVERAGE. A STATIONARY FRONT WAS LOCATED TO OUR SOUTHWEST THIS MORNING. MODELS SHOW THIS FRONTAL BOUNDARY LIFTING NORTHEAST INTO OUR FAR SOUTHWEST CWFA BY THIS AFTN. THE PROXIMITY OF THIS BOUNDARY ALONG WITH VARYING AMOUNTS OF CLOUD COVER WILL MAKE FORECASTING HIGH TEMPERATURES QUITE DIFFICULT. HAVE USED A SREF BLEND AS A STARTING POINT. THIS RESULTS IN HIGHS RANGING FROM THE UPPER 50S FAR N AND NE TO NEAR 80 FAR SOUTHWEST. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... FRONTAL BOUNDARY WILL PUSH JUST SOUTH OF OUR AREA TONIGHT AS HIGH PRESSURE BUILDS EAST INTO THE GREAT LAKES. THERE COULD BE A SMALL CHANCE OF A SHOWER/STORM EARLY ON NORTH OF THE FRONT...BUT ACTIVITY SHOULD CEASE AFTERNOON MIDNIGHT. SKIES WILL CLEAR FROM THE NORTH BUT REMAIN AT LEAST PARTLY CLOUDY ALONG AND SOUTH OF THE OHIO RIVER. FOR TUESDAY...SURFACE HIGH MOVES EAST AS FRONTAL BOUNDARY REMAINS QUASI STATIONARY. AMPLE SUNSHINE ACRS THE NORTH WILL RESULT IN WARMER HIGHS THAN TODAY. HIGHS WILL RANGE FROM THE MID 60S NORTH TO THE MID 70S FAR SOUTH. FOR TUESDAY NIGHT INTO WEDNESDAY...MODELS CONCUR THAT A MID LEVEL RIDGE WILL BUILD EAST TO THE GREAT LAKES AND OHIO VALLEY. AS THIS OCCURS...AFOREMENTIONED FRONTAL BOUNDARY WILL MOVE NORTHEAST AS A WARM FRONT. HAVE MAINTAINED A LOW CHANCE OF A SHOWER/STORMS WITH THE WARM FRONT PASSAGE ACROSS THE NORTH AS WEAK FORCING IS DEPICTED IN THIS AREA. THE ENTIRE CWFA SHOULD BECOME WARM SECTORED BY WEDNESDAY AFTERNOON. UNDER BREEZY CONDITIONS...TEMPERATURES WILL RISE INTO THE UPPER 70S TO THE LOWER 80S. FOR WEDNESDAY NIGHT INTO THURSDAY...MID LEVEL RIDGE AXIS WILL BEGIN TO MOVE EAST. WARM AND DRY WEATHER IS EXPECTED WITH HIGHS IN THE LOWER 80S ON THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... MOST OF THE CONCERN IN THIS PERIOD WILL RESIDE ON FRI/SAT/SUN ATTENDANT TO APPROACH OF SHORTWAVE TROUGH ENERGY EJECTING OUT OF LARGER SCALE LONGWAVE TROUGH TO THE WEST...PUSHING A SLOWING/WEAKENING FRONTAL BOUNDARY INTO THE OHIO VALLEY. FORECAST CONFIDENCE IN THIS TIME RANGE IS ACTUALLY QUITE GOOD THROUGH FRIDAY...BUT DIMINISHES SAT/SUN AS DIFFERENCES IN SHORTWAVE DISTRIBUTION/TIMING IN THE LARGER SCALE FLOW DEVELOPS WITH TIME. SHORTWAVE EJECTS AND DEEPENS WITH A LITTLE MORE FERVOR ON THURS AFTN/FRIDAY...BEING ENVELOPED INTO LARGE SCALE CLOSED LOW OVER SCNTL CANADA ON FRI AS IT PASSES WELL TO OUR NW INTO MN AND WRN ONTARIO. THIS WILL LEAD TO FALLING HEIGHTS OVER THE GREAT LAKES WHICH ALLOWS A COLD FRONT TO PUSH INTO THE AREA FRI NIGHT/SATURDAY. WITH PARENT DYNAMICS ALREADY ABSORBED INTO STATIONARY SCNTL CANADA CYCLONE...LOW LEVEL FRONTOLYTIC PROCESSES WILL BE ONGOING AND HAVE DOUBTS HOW STRONG /OR FAR SOUTH/ THIS FRONT WILL GET THROUGH SATURDAY GIVEN UPSTREAM ENERGY COMING BACK INTO THE LONGWAVE TROUGH TO THE WEST. MOST 04.12Z GUIDANCE WANTS TO TRICKLE FRONT INTO THE OHIO RIVER AREA BEFORE STALLING...AND PERHAPS AWAITING SRN STREAM WAVE TO BE INDUCED AND THEN RIDE ALONG IT. EITHER WAY...ALL 04.12Z AND 04.00Z DETERMINISTIC RUNS SUPPORT ENSEMBLE MEAN/PROBABILISTICS THAT SHOW SHOWERS/STORMS PUSHING INTO THE AREA FROM WEST TO EAST ON FRIDAY AFTERNOON/NIGHT GIVEN MODEST INSTBY/ABOVE NORMAL PWAT/AND LOW LEVEL BOUNDARY. NOT REALLY TOO CONCERNED ABOUT A MORE APPRECIABLE SVR THREAT - LOW LEVEL MOISTURE AND FLOW IS RATHER MARGINAL AS THE FRONT LOSES STEAM...AND AND LACK OF FURTHER HEIGHT FALLS AND SLOWING FRONT ISN/T TYPICALLY THE BEST ENVIRONMENT FOR SVR. ACTUALLY A LITTLE MORE CONCERNED FOR HEAVY RAIN IF SRN STREAM WAVE INDEED RIPPLES THE BOUNDARY SAT/SAT NIGHT /AS PER 04.00Z ECMWF/. A LOT MORE UNCERTAINTY HERE...WHICH MAKES SUNDAY FORECAST VERY LOW CONFIDENCE DEPENDING ON TIMING OF ANY WAVES IN THE DEAMPLIFYING FLOW/BROAD LONGWAVE TROUGH TO THE WEST. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AREAS OF RAIN WILL CONTINUE TO MOVE ACROSS THE REGION THIS MORNING. MOST OF THE RAIN IS FAIRLY LIGHT (AND SHOULD STAY IN THE VFR CATEGORY)...BUT A FEW EMBEDDED THUNDERSTORMS HAVE ALSO EXISTED...AND COULD POSSIBLY AFFECT THE COLUMBUS TAF SITES THIS MORNING. THE MORE LIKELY SCENARIO (AS INCLUDED IN THE 12Z TAFS) IS THAT ONLY VFR RAIN SHOWERS (WITH RELATIVELY HIGH CLOUD BASES) WILL PREVAIL FOR A WHILE. RAIN WILL BECOME LESS LIKELY BY LATE MORNING. DRY CONDITIONS ARE THEN EXPECTED THROUGH THE AFTERNOON. AS THE NWS WILMINGTON OHIO FORECAST AREA WILL REMAIN NORTH OF THE SURFACE BOUNDARY...WINDS AT THE TAF SITES ARE EXPECTED TO REMAIN EASTERLY THROUGH THE DAY. THERE IS ANOTHER CHANCE OF SOME SHOWERS DEVELOPING EARLY ON TUESDAY MORNING...AND A VCSH HAS BEEN INCLUDED FOR THE DAYTON AND CINCINNATI TAFS. OUTLOOK...SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON WEDNESDAY MORNING. SHOWERS AND THUNDERSTORMS ARE MORE LIKELY ON FRIDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HICKMAN NEAR TERM...HICKMAN SHORT TERM...HICKMAN LONG TERM...BINAU AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
553 AM EDT MON MAY 5 2014 .SYNOPSIS... AN EMBEDDED DISTURBANCE WITHIN A NORTHWEST FLOW ALOFT WILL BRING A THREAT FOR SHOWERS AND THUNDERSTORMS TO PARTS OF THE REGION TODAY. AT THE SAME TIME...A FRONTAL BOUNDARY LOCATED TO OUR SOUTHWEST WILL NUDGE A LITTLE FARTHER NORTHEAST THIS AFTERNOON. THE PROXIMITY OF THIS FRONT WILL RESULT IN A WIDE RANGE OF HIGH TEMPERATURES. FOR TONIGHT INTO TUESDAY...SURFACE HIGH PRESSURE ACROSS THE GREAT LAKES WILL PUSH THE FRONT JUST SOUTH OF OUR AREA ONCE AGAIN. THE FRONT WILL THEN RETURN NORTHEAST AS A WARM FRONT TUESDAY NIGHT INTO WEDNESDAY. TEMPERATURES WILL WARM APPRECIABLY ALL AREAS IN THE WAKE OF THE WARM FRONT WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... BASED ON LATEST RADAR TRENDS AND THE HRRR MODEL...WILL TRANSLATE LIKELY POPS TO THE NRN/NERN CWFA THIS MORNING WITH DECREASING CHANCES HEADING TOWARD THE SW CWFA. HIGHER POPS ARE BEING EMPLOYED N AND NE IN RESPONSE TO AN APPROACHING S/WV IN THE NW FLOW ALOFT. IT NOW LOOKS LIKE ELEVATED INSTABILITY WILL WEAKEN AS IT HEADS EAST SO HAVE LOWERED THE THREAT OF THUNDER TO SLIGHT CHANCE. BY THIS AFTERNOON...WE SHOULD SEE A MINIMUM IN PCPN COVERAGE. A STATIONARY FRONT WAS LOCATED TO OUR SOUTHWEST THIS MORNING. MODELS SHOW THIS FRONTAL BOUNDARY LIFTING NORTHEAST INTO OUR FAR SOUTHWEST CWFA BY THIS AFTN. THE PROXIMITY OF THIS BOUNDARY ALONG WITH VARYING AMOUNTS OF CLOUD COVER WILL MAKE FORECASTING HIGH TEMPERATURES QUITE DIFFICULT. HAVE USED A SREF BLEND AS A STARTING POINT. THIS RESULTS IN HIGHS RANGING FROM THE UPPER 50S FAR N AND NE TO NEAR 80 FAR SOUTHWEST. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... FRONTAL BOUNDARY WILL PUSH JUST SOUTH OF OUR AREA TONIGHT AS HIGH PRESSURE BUILDS EAST INTO THE GREAT LAKES. THERE COULD BE A SMALL CHANCE OF A SHOWER/STORM EARLY ON NORTH OF THE FRONT...BUT ACTIVITY SHOULD CEASE AFTERNOON MIDNIGHT. SKIES WILL CLEAR FROM THE NORTH BUT REMAIN AT LEAST PARTLY CLOUDY ALONG AND SOUTH OF THE OHIO RIVER. FOR TUESDAY...SURFACE HIGH MOVES EAST AS FRONTAL BOUNDARY REMAINS QUASI STATIONARY. AMPLE SUNSHINE ACRS THE NORTH WILL RESULT IN WARMER HIGHS THAN TODAY. HIGHS WILL RANGE FROM THE MID 60S NORTH TO THE MID 70S FAR SOUTH. FOR TUESDAY NIGHT INTO WEDNESDAY...MODELS CONCUR THAT A MID LEVEL RIDGE WILL BUILD EAST TO THE GREAT LAKES AND OHIO VALLEY. AS THIS OCCURS...AFOREMENTIONED FRONTAL BOUNDARY WILL MOVE NORTHEAST AS A WARM FRONT. HAVE MAINTAINED A LOW CHANCE OF A SHOWER/STORMS WITH THE WARM FRONT PASSAGE ACROSS THE NORTH AS WEAK FORCING IS DEPICTED IN THIS AREA. THE ENTIRE CWFA SHOULD BECOME WARM SECTORED BY WEDNESDAY AFTERNOON. UNDER BREEZY CONDITIONS...TEMPERATURES WILL RISE INTO THE UPPER 70S TO THE LOWER 80S. FOR WEDNESDAY NIGHT INTO THURSDAY...MID LEVEL RIDGE AXIS WILL BEGIN TO MOVE EAST. WARM AND DRY WEATHER IS EXPECTED WITH HIGHS IN THE LOWER 80S ON THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... MOST OF THE CONCERN IN THIS PERIOD WILL RESIDE ON FRI/SAT/SUN ATTENDANT TO APPROACH OF SHORTWAVE TROUGH ENERGY EJECTING OUT OF LARGER SCALE LONGWAVE TROUGH TO THE WEST...PUSHING A SLOWING/WEAKENING FRONTAL BOUNDARY INTO THE OHIO VALLEY. FORECAST CONFIDENCE IN THIS TIME RANGE IS ACTUALLY QUITE GOOD THROUGH FRIDAY...BUT DIMINISHES SAT/SUN AS DIFFERENCES IN SHORTWAVE DISTRIBUTION/TIMING IN THE LARGER SCALE FLOW DEVELOPS WITH TIME. SHORTWAVE EJECTS AND DEEPENS WITH A LITTLE MORE FERVOR ON THURS AFTN/FRIDAY...BEING ENVELOPED INTO LARGE SCALE CLOSED LOW OVER SCNTL CANADA ON FRI AS IT PASSES WELL TO OUR NW INTO MN AND WRN ONTARIO. THIS WILL LEAD TO FALLING HEIGHTS OVER THE GREAT LAKES WHICH ALLOWS A COLD FRONT TO PUSH INTO THE AREA FRI NIGHT/SATURDAY. WITH PARENT DYNAMICS ALREADY ABSORBED INTO STATIONARY SCNTL CANADA CYCLONE...LOW LEVEL FRONTOLYTIC PROCESSES WILL BE ONGOING AND HAVE DOUBTS HOW STRONG /OR FAR SOUTH/ THIS FRONT WILL GET THROUGH SATURDAY GIVEN UPSTREAM ENERGY COMING BACK INTO THE LONGWAVE TROUGH TO THE WEST. MOST 04.12Z GUIDANCE WANTS TO TRICKLE FRONT INTO THE OHIO RIVER AREA BEFORE STALLING...AND PERHAPS AWAITING SRN STREAM WAVE TO BE INDUCED AND THEN RIDE ALONG IT. EITHER WAY...ALL 04.12Z AND 04.00Z DETERMINISTIC RUNS SUPPORT ENSEMBLE MEAN/PROBABILISTICS THAT SHOW SHOWERS/STORMS PUSHING INTO THE AREA FROM WEST TO EAST ON FRIDAY AFTERNOON/NIGHT GIVEN MODEST INSTBY/ABOVE NORMAL PWAT/AND LOW LEVEL BOUNDARY. NOT REALLY TOO CONCERNED ABOUT A MORE APPRECIABLE SVR THREAT - LOW LEVEL MOISTURE AND FLOW IS RATHER MARGINAL AS THE FRONT LOSES STEAM...AND AND LACK OF FURTHER HEIGHT FALLS AND SLOWING FRONT ISN/T TYPICALLY THE BEST ENVIRONMENT FOR SVR. ACTUALLY A LITTLE MORE CONCERNED FOR HEAVY RAIN IF SRN STREAM WAVE INDEED RIPPLES THE BOUNDARY SAT/SAT NIGHT /AS PER 04.00Z ECMWF/. A LOT MORE UNCERTAINTY HERE...WHICH MAKES SUNDAY FORECAST VERY LOW CONFIDENCE DEPENDING ON TIMING OF ANY WAVES IN THE DEAMPLIFYING FLOW/BROAD LONGWAVE TROUGH TO THE WEST. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... CONDITIONS ARE TRANQUIL AT THE START OF THE TAF PERIOD...BUT SHOWERS AND POSSIBLY SOME THUNDERSTORMS ARE EXPECTED TO DEVELOP BETWEEN 08Z AND 12Z. CONFIDENCE IN STORM LOCATION AND TIMING IS STILL NOT VERY HIGH...SO CONDITIONS HAVE BEEN KEPT RATHER GENERIC IN THE TAFS. WHILE CEILINGS ARE LIKELY TO REMAIN VFR...HEAVIER SHOWERS WILL BE CAPABLE OF MVFR VISIBILITIES. A FEW SHOWERS MAY PERSIST INTO THE DAY (ESPECIALLY FOR THE COLUMBUS TAF SITES)...BUT GENERALLY DRY CONDITIONS ARE EXPECTED. AS THE NWS WILMINGTON OHIO FORECAST AREA WILL REMAIN NORTH OF THE SURFACE BOUNDARY...WINDS AT THE TAF SITES ARE EXPECTED TO REMAIN EASTERLY THROUGH THE DAY. THERE IS ANOTHER SLIGHT CHANCE OF SOME SHOWERS DEVELOPING EARLY ON TUESDAY MORNING. OUTLOOK...SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON WEDNESDAY MORNING. SHOWERS AND THUNDERSTORMS ARE MORE LIKELY ON FRIDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HICKMAN NEAR TERM...HICKMAN SHORT TERM...HICKMAN LONG TERM...BINAU AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1052 PM CDT TUE MAY 6 2014 .UPDATE... ISSUED AT 919 PM CDT TUE MAY 6 2014 HAVE UPDATED TO INCREASE CHANCE POPS FURTHER WEST THAN WHAT WE HAVE BEEN CARRYING. HRRR HAS BEEN CONSISTENTLY CARRYING DEVELOPMENT STARTING BY 06Z AROUND FSD AND EAST...WITH THIS ORDINARY CONVECTION THEN MOVING NORTH LATE TONIGHT INTO THE EARLY MORNING. BOTH THE 18Z AND NEW 00Z NAM12 INDICATE A MID LEVEL BOUNDARY COUPLED WITH A TIGHT THETA E GRADIENT WHICH CLOSELY MATCHES THE HRRR FORECAST DEVELOPMENT. THE ACTIVITY SHOULD THEN MOVE NORTHEAST OF THE AREA DURING WEDNESDAY MORNING INSTEAD OF FADING OFF TO THE EAST AS WE HAD BEFORE. MAIN POINT OF THE UPDATE IS WE SEEM TO NEED A LITTLE MORE THAN BARELY MENTIONABLE SLIGHT CHANCE POPS WEST OF THE EASTERN SD BORDER. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 340 PM CDT TUE MAY 6 2014 NOT MUCH GOING ON AROUND THE REGION THIS AFTERNOON WITH LOW PRESSURE AND ASSOCIATED WARM FRONT STILL LOCATED OVER THE CENTRAL PLAINS AT THE THIS TIME. THESE FEATURES WILL SLOWLY MOVE TO THE NORTH OVERNIGHT...AND STILL COULD SEE SCATTERED ELEVATED CONVECTION DEVELOP IN PORTIONS OF OUR EAST LATER TONIGHT WITH INCREASING THETA E ADVECTION/INSTABILITY AND LOWER LEVEL CONVERGENCE AS A LOW LEVEL JET DEVELOPS THROUGH EASTERN NEBRASKA AND WESTERN IOWA. ELEVATED CAPE WILL ACTUALLY BE FAIRLY DECENT...RUNNING AROUND 1500 J/KG...THOUGH ANY PARCEL WILL BE LIFTED ABOVE THE BETTER DIRECTIONAL SHEAR...THUS LOOKING AT ANY USABLE SHEAR IN THE FORM OF MAINLY SPEED SHEAR...AND THAT BEING AROUND 25 KTS. IN LIGHT OF THAT...NOT EXPECTING MUCH IN THE WAY OF SEVERE STORMS. IT WILL BE A MILD NIGHT ACROSS THE AREA WITH LOWS IN THE 50S. ANY OVERNIGHT CONVECTION SHOULD QUICKLY WANE BY WEDNESDAY MORNING AS FORCING IS LOST. AFTER THAT...THINK MUCH OF THE AREA WILL BE DRY INTO THE AFTERNOON WITH THE SURFACE LOW PRESSURE NUDGING INTO NEBRASKA AND A WARM FRONT LIFTING INTO THE SOUTHEASTERN PORTIONS OF OUR CWA. WITH A STRENGTHENING CAP THROUGH MUCH OF THE SOUTHERN AND EASTERN PORTIONS OF THE CWA DURING THE DAY...NOT EXPECTING CONVECTION THROUGH THAT AREA DURING THE AFTERNOON...THOUGH THERE WILL BE A POSSIBILITY OF CONVECTION DEVELOPING ACROSS MAINLY OUR WEST AND NORTHWEST IN THE VICINITY OF THE LOW/MIDLEVEL FRONT...WITH INCREASING UPPER LEVEL SUPPORT PROVIDED BY AN UPPER LEVEL JET BEGINNING TO STREAM THROUGH THE CENTRAL PORTIONS OF NEBRASKA AND SOUTH DAKOTA. WOULD NOT EXPECT MUCH IN THE WAY OF SEVERE WEATHER WITH ANY ACTIVITY THAT DEVELOPS OVER THIS AREA WITH THE BETTER INSTABILITY REMAINING FARTHER TO THE SOUTH AND EAST IN THE WARM SECTOR OF THE SYSTEM. WITH THE FRONTAL BOUNDARY BISECTING THE CWA DURING THE DAY...THERE WILL BE A WIDE RANGE OF TEMPERATURES ACROSS THE AREA. THIS WILL PLAY OUT TO HIGHS IN THE UPPER 60S ACROSS THE FAR NORTH AND WEST...TO THE 80S OVER NORTHWESTERN IOWA...REACHING 90 AROUND SIOUX CITY. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 340 PM CDT TUE MAY 6 2014 WEDNESDAY NIGHT...THE GFS AND NAM HAVE TAKEN THEIR RESPECTIVE SURFACE LOWS AND GIVEN THEM A DECIDED TILT TOWARD A SLIGHTLY FURTHER EAST SOLUTION...MORE SIMILAR TO WHAT THE EUROPEAN AND CANADIAN MODELS HAVE BEEN SHOWING FOR A FEW DAYS NOW. BECAUSE OF THIS... NUDGED THE DRY SLOT A BIT FURTHER EASTWARD INTO THE HEART OF NORTHWEST IA WHERE WE LEFT THINGS DRY. THEN SLOWLY BUT SURELY INCREASED POPS HEADING WESTWARD TO WHERE LOW END CATEGORICAL POPS ARE WARRANTED INTO THE DEEP...COOL AND SATURATED AIR MASS IN CENTRAL SD. THE NAM12 AND HIRES NAM ARE BRINGING A CLUSTER OF SHOWER AND THUNDERSTORMS NORTHEASTWARD ACROSS OUR WESTERN ZONES IN THE LATE EVENING AND OVERNIGHT HOURS BEHIND THE LOW...ALONG AN AXIS OF STRONG MID LEVEL FRONTOGENESIS...AND SHORT WAVE ENERGY JUST A BIT FURTHER TO THE WEST. CANNOT TOTALLY RULE OUT THE SCENARIO OF THAT HAPPENING AS THE SATURATION IS QUITE DEEP AS MENTIONED ABOVE. CONCERNING SEVERE WEATHER CHANCES WEDNESDAY NIGHT...RIGHT NOW IF ANY SEVERE WEATHER PANS OUT IT LOOKS TO BE ALONG AN AXIS FROM YANKTON...TO SIOUX FALLS...TO BROOKINGS AND MARSHALL. THESE LOCATIONS ARE PLACED IN BETWEEN THE MORE STABLE AIR TO THE WEST...AND THE DRY SLOTTING PROJECTED IN NORTHWEST IA. STORMS WILL BE ELEVATED...AND 850MB MU CAPES ARE IN THE RANGE OF 1500-2000 J/KG FOR THESE LOCATIONS. THAT SAID...THE TREMENDOUS VEERING SHEAR PROFILES IN THE LOWEST KILOMETER WILL NOT BE TAPPED...SO IF SEVERE WEATHER DEVELOPS...NOT EXPECTING A TON OF IT...NOR ESPECIALLY STRONG. BUT CALCULATED BULK SHEAR VECTORS IN THE 850-500MB LAYER WHICH SHOW A STOUT 40-50 KNOTS DURING THE EVENING SO THAT PARAMETER IS RATHER STRONG...IT JUST MAY BE HARD TO MAINTAIN AN UPDRAFT FOR VERY LONG. FOR LOWS...THIS TIME AROUND SOME OF THE BIAS CORRECTED VALUES LOOKED A BIT TOO COLD ACROSS THE FORECAST AREA GIVEN THE DEGREE OF PROJECTED CLOUD COVER...ESPECIALLY WEST OF I 29. THEREFORE PREFERRED LOWS USING MORE OF THE RAW BLEND NUMBERS AND SOME ECMWF MOS. THURSDAY IS VERY INTERESTING IN THAT THERE ARE NOW INDICATIONS OF A WET DAY IN THE AREA. THE WESTERN ZONES ARE STILL IN THE DEEP...COOL AND SATURATED AIR. BUT FROM I 29 AND POINTS EAST...IT APPEARS THAT THE CRUX OF THE UPPER LOW AND ACCOMPANYING SHORT WAVE MOVES UP AND ACROSS OUR EASTERN ZONES DURING THE AFTERNOON. WHATS LEFT OF THE DRY SLOT IN THE MORNING WILL LIKELY FILL IN THROUGH THE AFTERNOON. SO FOR THE AFTERNOON HOURS...HAVE LIKELY POPS IN MANY AREAS...EXCEPT FOR THE LINGERING CATEGORICAL POPS IN OUR FAR WEST. IN THE MIDDLE... RAISED POPS INTO THE HIGH CHANCE CATEGORY WHERE THE LAST REMNANTS OF DRY SLOTTING MAY EXIST. BUT IF THESE LATEST TRENDS CONTINUE...NEARLY ALL OF THE FORECAST AREA STANDS TO RECEIVE RAIN THURSDAY AFTERNOON. REALLY ONLY THE NAM IS SHOWING A DRY THURSDAY AFTERNOON FOR MANY AREAS WITH THE REST OF THE MODELS...INCLUDING THE GFS...REVERTING BACK TO THEIR SOLUTIONS OF A FEW DAYS AGO AND KEEPING THINGS WET. SEVERE WEATHER IS PROBLEMATIC ON THURSDAY AND COULD STAY EAST OF OUR AREA. BUT CANNOT RULE OUT A BIT OF SEVERE WEATHER IN OUR FAR EASTERN ZONES THURSDAY AFTERNOON IN THE WARM SECTOR...WITH THE GFS 925MB-850MB MU CAPE VALUES AVERAGING CLOSE TO 2000 J/KG EAST OF I 29. BUT SIMILAR TO WEDNESDAY NIGHT...MUCH OF THE VEERING WIND SHEAR IN THE LOWEST KILOMETER MAY NOT BE TAPPED AS THE STORMS MAY BE SOMEWHAT ELEVATED. IN ADDITION...MANY HIGHS ALONG AND EAST OF I 29 WILL LIKELY BE REALIZED BY MIDDAY WITH SLOWLY FALLING AFTERNOON TEMPERATURES WHICH COULD INHIBIT OVERALL INSTABILITY. THE POWERFUL WAVE EXITS NORTHEAST OF OUR AREA THURSDAY NIGHT AND WEAKENS. OPTED TO PLACE LIKELY POPS FOR LINGERING RAINFALL IN OUR NORTHERN ZONES...WITH A DRY FRIDAY TO FOLLOW. FRIDAY LOOKS FAIRLY PLEASANT RIGHT NOW WITH HIGHS IN THE 60S...BUT NORTHWEST WINDS WILL BE A BIT ON THE BREEZY SIDE. FOR THE EXTENDED PORTION OF THE FORECAST...DETERMINISTIC MODELS ARE IN GOOD AGREEMENT ON SATURDAY IN BRINGING A ROBUST SHORT WAVE RIGHT ACROSS OUR ZONES THROUGH THE DAY. STRONG CHANCE POPS ARE WARRANTED AND IF THESE TRENDS CONTINUE...WILL PROBABLY UPGRADE TO LIKELY OR EVEN CATEGORICAL IN FUTURE FORECASTS. INSTABILITY AT AND BELOW 925MB IS MEAGER...BUT THERE IS A BIT OF INSTABILITY UPSTAIRS AROUND 850-800MB SO CARRIED A CHANCE FOR ISOLATED THUNDER EMBEDDED IN THE SHOWER ACTIVITY. DID NOT ALTER THE GOING HIGHS MUCH AT ALL AS MIXING STILL SUGGESTS READINGS GENERALLY ABOUT 65 TO 70. THE SYSTEM EXITS QUICKLY SATURDAY NIGHT. POPS MAY BE NEED TO BE DROPPED IN OUR WESTERN ZONES IN FUTURE FORECASTS. BUT THEN THE MODELS BEGIN TO DIVERGE RAPIDLY IN THE SUNDAY THROUGH TUESDAY TIME FRAME. ACTUALLY THE ECMWF/GEM GLOBAL/UKMET ARE IN ONE CAMP IN TAKING THE NEXT UPPER WAVE AND DIGGING IT SOUTHEASTWARD TOWARD THE SOUTHERN ROCKIES BY 12Z MONDAY. THE ECMWF THEN EJECTS THE WAVE THROUGH THE PLAINS IN THE MONDAY AND TUESDAY TIME FRAME. THE 12Z GFS IS A SEVERE OUTLIER IN THAT AFTER THE SHORT WAVE OF SATURDAY AND SATURDAY NIGHT EXITS...IT HAS NOTHING TO DO WITH ANY SEMBLANCE OF A LARGE UPPER TROUGH DIGGING THROUGH THE WESTERN UNITED STATES. AT THE SURFACE...IT IS PROBABLE THAT LOW PRESSURE WILL DEVELOP IN RESPONSE IN COLORADO...THEN EXIT VIA THE SOUTHERN AND EASTERN PLAINS ON MONDAY AND TUESDAY. THIS WILL PLACE OUR FORECAST AREA MAINLY ON THE COOL SIDE OF THE DEVELOPING WARM FRONT KEEPING INSTABILITY LIMITED. FOR NOW...THE SURFACE WIND PATTERN REFLECTS A BLEND COMPOSITE...BUT HEDGED THE PRECIP AND INSTABILITY FORECAST DEFINITELY TOWARD THE ECMWF/GEM/UKMET. THEREFORE THE PATTERN LOOKS RATHER UNSETTLED. NOW DEPENDING ON THE AMOUNT OF CLOUD COVER...WOULD NOT BE SURPRISED IF HIGH TEMPERATURES TURN OUT A BIT COOLER SUNDAY THROUGH TUESDAY BEING ON THE COOL SIDE OF THE SYSTEM. ALREADY BLENDED SOME COOLER GUIDANCE READINGS INTO THE ALLBLEND TO BEGIN A SLOW TREND TO REFLECT THIS THINKING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1051 PM CDT TUE MAY 6 2014 LOW CLOUDS AND THUNDERSTORM CHANCES ARE THE MAIN CONCERN FOR AVIATION. FOR CONVECTION...WHILE THERE LOOKS TO BE SCATTERED CONVECTION EAST AND NORTH OF SIOUX FALLS...THE CHANCES DECREASE MARKEDLY TOWARD SIOUX FALLS AND ARE EVEN LESS IN HURON AND SIOUX CITY. SIMILARLY...FOR LATE WED AFTERNOON AND NIGHT...THE BEST CHANCE FOR CONVECTION LOOKS TO BE IN SW MN WITH ALMOST NO CHANCE IN SIOUX CITY AND SIOUX FALLS AND A LOW CHANCE IN HURON. SO DECIDED NOT TO ADD ANY CONVECTION TO TAF THROUGH 06Z THURSDAY. AS FOR CLOUDS...THERE WILL LIKELY BE SCATTERED TO BROKEN STRATUS AS THE MID LEVEL WARM FRONT MOVES NORTH. FOR SIOUX CITY...THE MOISTURE APPEARS TOO LIMITED TO GET MORE THAN SCATTERED BUT WITH THE FRONT APPROACHING SIOUX FALL IN THE LATE MORNING AND AFTERNOON DID KEEP A BROKEN MVFR CIG IN FROM 16Z TO 20Z. FOR KHON AS MOISTURE GETS ADVECTED WEST...EXPECT LOW CLOUDS THERE AS WELL AFTER 00Z THURSDAY...AGAIN...MOSTLY LIKELY MVFR. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE... SHORT TERM...JM LONG TERM...MJ AVIATION...SCHUMACHER
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
919 PM CDT TUE MAY 6 2014 .UPDATE... ISSUED AT 919 PM CDT TUE MAY 6 2014 HAVE UPDATED TO INCREASE CHANCE POPS FURTHER WEST THAN WHAT WE HAVE BEEN CARRYING. HRRR HAS BEEN CONSISTENTLY CARRYING DEVELOPMENT STARTING BY 06Z AROUND FSD AND EAST...WITH THIS ORDINARY CONVECTION THEN MOVING NORTH LATE TONIGHT INTO THE EARLY MORNING. BOTH THE 18Z AND NEW 00Z NAM12 INDICATE A MID LEVEL BOUNDARY COUPLED WITH A TIGHT THETA E GRADIENT WHICH CLOSELY MATCHES THE HRRR FORECAST DEVELOPMENT. THE ACTIVITY SHOULD THEN MOVE NORTHEAST OF THE AREA DURING WEDNESDAY MORNING INSTEAD OF FADING OFF TO THE EAST AS WE HAD BEFORE. MAIN POINT OF THE UPDATE IS WE SEEM TO NEED A LITTLE MORE THAN BARELY MENTIONABLE SLIGHT CHANCE POPS WEST OF THE EASTERN SD BORDER. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 340 PM CDT TUE MAY 6 2014 NOT MUCH GOING ON AROUND THE REGION THIS AFTERNOON WITH LOW PRESSURE AND ASSOCIATED WARM FRONT STILL LOCATED OVER THE CENTRAL PLAINS AT THE THIS TIME. THESE FEATURES WILL SLOWLY MOVE TO THE NORTH OVERNIGHT...AND STILL COULD SEE SCATTERED ELEVATED CONVECTION DEVELOP IN PORTIONS OF OUR EAST LATER TONIGHT WITH INCREASING THETA E ADVECTION/INSTABILITY AND LOWER LEVEL CONVERGENCE AS A LOW LEVEL JET DEVELOPS THROUGH EASTERN NEBRASKA AND WESTERN IOWA. ELEVATED CAPE WILL ACTUALLY BE FAIRLY DECENT...RUNNING AROUND 1500 J/KG...THOUGH ANY PARCEL WILL BE LIFTED ABOVE THE BETTER DIRECTIONAL SHEAR...THUS LOOKING AT ANY USABLE SHEAR IN THE FORM OF MAINLY SPEED SHEAR...AND THAT BEING AROUND 25 KTS. IN LIGHT OF THAT...NOT EXPECTING MUCH IN THE WAY OF SEVERE STORMS. IT WILL BE A MILD NIGHT ACROSS THE AREA WITH LOWS IN THE 50S. ANY OVERNIGHT CONVECTION SHOULD QUICKLY WANE BY WEDNESDAY MORNING AS FORCING IS LOST. AFTER THAT...THINK MUCH OF THE AREA WILL BE DRY INTO THE AFTERNOON WITH THE SURFACE LOW PRESSURE NUDGING INTO NEBRASKA AND A WARM FRONT LIFTING INTO THE SOUTHEASTERN PORTIONS OF OUR CWA. WITH A STRENGTHENING CAP THROUGH MUCH OF THE SOUTHERN AND EASTERN PORTIONS OF THE CWA DURING THE DAY...NOT EXPECTING CONVECTION THROUGH THAT AREA DURING THE AFTERNOON...THOUGH THERE WILL BE A POSSIBILITY OF CONVECTION DEVELOPING ACROSS MAINLY OUR WEST AND NORTHWEST IN THE VICINITY OF THE LOW/MIDLEVEL FRONT...WITH INCREASING UPPER LEVEL SUPPORT PROVIDED BY AN UPPER LEVEL JET BEGINNING TO STREAM THROUGH THE CENTRAL PORTIONS OF NEBRASKA AND SOUTH DAKOTA. WOULD NOT EXPECT MUCH IN THE WAY OF SEVERE WEATHER WITH ANY ACTIVITY THAT DEVELOPS OVER THIS AREA WITH THE BETTER INSTABILITY REMAINING FARTHER TO THE SOUTH AND EAST IN THE WARM SECTOR OF THE SYSTEM. WITH THE FRONTAL BOUNDARY BISECTING THE CWA DURING THE DAY...THERE WILL BE A WIDE RANGE OF TEMPERATURES ACROSS THE AREA. THIS WILL PLAY OUT TO HIGHS IN THE UPPER 60S ACROSS THE FAR NORTH AND WEST...TO THE 80S OVER NORTHWESTERN IOWA...REACHING 90 AROUND SIOUX CITY. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 340 PM CDT TUE MAY 6 2014 WEDNESDAY NIGHT...THE GFS AND NAM HAVE TAKEN THEIR RESPECTIVE SURFACE LOWS AND GIVEN THEM A DECIDED TILT TOWARD A SLIGHTLY FURTHER EAST SOLUTION...MORE SIMILAR TO WHAT THE EUROPEAN AND CANADIAN MODELS HAVE BEEN SHOWING FOR A FEW DAYS NOW. BECAUSE OF THIS... NUDGED THE DRY SLOT A BIT FURTHER EASTWARD INTO THE HEART OF NORTHWEST IA WHERE WE LEFT THINGS DRY. THEN SLOWLY BUT SURELY INCREASED POPS HEADING WESTWARD TO WHERE LOW END CATEGORICAL POPS ARE WARRANTED INTO THE DEEP...COOL AND SATURATED AIR MASS IN CENTRAL SD. THE NAM12 AND HIRES NAM ARE BRINGING A CLUSTER OF SHOWER AND THUNDERSTORMS NORTHEASTWARD ACROSS OUR WESTERN ZONES IN THE LATE EVENING AND OVERNIGHT HOURS BEHIND THE LOW...ALONG AN AXIS OF STRONG MID LEVEL FRONTOGENESIS...AND SHORT WAVE ENERGY JUST A BIT FURTHER TO THE WEST. CANNOT TOTALLY RULE OUT THE SCENARIO OF THAT HAPPENING AS THE SATURATION IS QUITE DEEP AS MENTIONED ABOVE. CONCERNING SEVERE WEATHER CHANCES WEDNESDAY NIGHT...RIGHT NOW IF ANY SEVERE WEATHER PANS OUT IT LOOKS TO BE ALONG AN AXIS FROM YANKTON...TO SIOUX FALLS...TO BROOKINGS AND MARSHALL. THESE LOCATIONS ARE PLACED IN BETWEEN THE MORE STABLE AIR TO THE WEST...AND THE DRY SLOTTING PROJECTED IN NORTHWEST IA. STORMS WILL BE ELEVATED...AND 850MB MU CAPES ARE IN THE RANGE OF 1500-2000 J/KG FOR THESE LOCATIONS. THAT SAID...THE TREMENDOUS VEERING SHEAR PROFILES IN THE LOWEST KILOMETER WILL NOT BE TAPPED...SO IF SEVERE WEATHER DEVELOPS...NOT EXPECTING A TON OF IT...NOR ESPECIALLY STRONG. BUT CALCULATED BULK SHEAR VECTORS IN THE 850-500MB LAYER WHICH SHOW A STOUT 40-50 KNOTS DURING THE EVENING SO THAT PARAMETER IS RATHER STRONG...IT JUST MAY BE HARD TO MAINTAIN AN UPDRAFT FOR VERY LONG. FOR LOWS...THIS TIME AROUND SOME OF THE BIAS CORRECTED VALUES LOOKED A BIT TOO COLD ACROSS THE FORECAST AREA GIVEN THE DEGREE OF PROJECTED CLOUD COVER...ESPECIALLY WEST OF I 29. THEREFORE PREFERRED LOWS USING MORE OF THE RAW BLEND NUMBERS AND SOME ECMWF MOS. THURSDAY IS VERY INTERESTING IN THAT THERE ARE NOW INDICATIONS OF A WET DAY IN THE AREA. THE WESTERN ZONES ARE STILL IN THE DEEP...COOL AND SATURATED AIR. BUT FROM I 29 AND POINTS EAST...IT APPEARS THAT THE CRUX OF THE UPPER LOW AND ACCOMPANYING SHORT WAVE MOVES UP AND ACROSS OUR EASTERN ZONES DURING THE AFTERNOON. WHATS LEFT OF THE DRY SLOT IN THE MORNING WILL LIKELY FILL IN THROUGH THE AFTERNOON. SO FOR THE AFTERNOON HOURS...HAVE LIKELY POPS IN MANY AREAS...EXCEPT FOR THE LINGERING CATEGORICAL POPS IN OUR FAR WEST. IN THE MIDDLE... RAISED POPS INTO THE HIGH CHANCE CATEGORY WHERE THE LAST REMNANTS OF DRY SLOTTING MAY EXIST. BUT IF THESE LATEST TRENDS CONTINUE...NEARLY ALL OF THE FORECAST AREA STANDS TO RECEIVE RAIN THURSDAY AFTERNOON. REALLY ONLY THE NAM IS SHOWING A DRY THURSDAY AFTERNOON FOR MANY AREAS WITH THE REST OF THE MODELS...INCLUDING THE GFS...REVERTING BACK TO THEIR SOLUTIONS OF A FEW DAYS AGO AND KEEPING THINGS WET. SEVERE WEATHER IS PROBLEMATIC ON THURSDAY AND COULD STAY EAST OF OUR AREA. BUT CANNOT RULE OUT A BIT OF SEVERE WEATHER IN OUR FAR EASTERN ZONES THURSDAY AFTERNOON IN THE WARM SECTOR...WITH THE GFS 925MB-850MB MU CAPE VALUES AVERAGING CLOSE TO 2000 J/KG EAST OF I 29. BUT SIMILAR TO WEDNESDAY NIGHT...MUCH OF THE VEERING WIND SHEAR IN THE LOWEST KILOMETER MAY NOT BE TAPPED AS THE STORMS MAY BE SOMEWHAT ELEVATED. IN ADDITION...MANY HIGHS ALONG AND EAST OF I 29 WILL LIKELY BE REALIZED BY MIDDAY WITH SLOWLY FALLING AFTERNOON TEMPERATURES WHICH COULD INHIBIT OVERALL INSTABILITY. THE POWERFUL WAVE EXITS NORTHEAST OF OUR AREA THURSDAY NIGHT AND WEAKENS. OPTED TO PLACE LIKELY POPS FOR LINGERING RAINFALL IN OUR NORTHERN ZONES...WITH A DRY FRIDAY TO FOLLOW. FRIDAY LOOKS FAIRLY PLEASANT RIGHT NOW WITH HIGHS IN THE 60S...BUT NORTHWEST WINDS WILL BE A BIT ON THE BREEZY SIDE. FOR THE EXTENDED PORTION OF THE FORECAST...DETERMINISTIC MODELS ARE IN GOOD AGREEMENT ON SATURDAY IN BRINGING A ROBUST SHORT WAVE RIGHT ACROSS OUR ZONES THROUGH THE DAY. STRONG CHANCE POPS ARE WARRANTED AND IF THESE TRENDS CONTINUE...WILL PROBABLY UPGRADE TO LIKELY OR EVEN CATEGORICAL IN FUTURE FORECASTS. INSTABILITY AT AND BELOW 925MB IS MEAGER...BUT THERE IS A BIT OF INSTABILITY UPSTAIRS AROUND 850-800MB SO CARRIED A CHANCE FOR ISOLATED THUNDER EMBEDDED IN THE SHOWER ACTIVITY. DID NOT ALTER THE GOING HIGHS MUCH AT ALL AS MIXING STILL SUGGESTS READINGS GENERALLY ABOUT 65 TO 70. THE SYSTEM EXITS QUICKLY SATURDAY NIGHT. POPS MAY BE NEED TO BE DROPPED IN OUR WESTERN ZONES IN FUTURE FORECASTS. BUT THEN THE MODELS BEGIN TO DIVERGE RAPIDLY IN THE SUNDAY THROUGH TUESDAY TIME FRAME. ACTUALLY THE ECMWF/GEM GLOBAL/UKMET ARE IN ONE CAMP IN TAKING THE NEXT UPPER WAVE AND DIGGING IT SOUTHEASTWARD TOWARD THE SOUTHERN ROCKIES BY 12Z MONDAY. THE ECMWF THEN EJECTS THE WAVE THROUGH THE PLAINS IN THE MONDAY AND TUESDAY TIME FRAME. THE 12Z GFS IS A SEVERE OUTLIER IN THAT AFTER THE SHORT WAVE OF SATURDAY AND SATURDAY NIGHT EXITS...IT HAS NOTHING TO DO WITH ANY SEMBLANCE OF A LARGE UPPER TROUGH DIGGING THROUGH THE WESTERN UNITED STATES. AT THE SURFACE...IT IS PROBABLE THAT LOW PRESSURE WILL DEVELOP IN RESPONSE IN COLORADO...THEN EXIT VIA THE SOUTHERN AND EASTERN PLAINS ON MONDAY AND TUESDAY. THIS WILL PLACE OUR FORECAST AREA MAINLY ON THE COOL SIDE OF THE DEVELOPING WARM FRONT KEEPING INSTABILITY LIMITED. FOR NOW...THE SURFACE WIND PATTERN REFLECTS A BLEND COMPOSITE...BUT HEDGED THE PRECIP AND INSTABILITY FORECAST DEFINITELY TOWARD THE ECMWF/GEM/UKMET. THEREFORE THE PATTERN LOOKS RATHER UNSETTLED. NOW DEPENDING ON THE AMOUNT OF CLOUD COVER...WOULD NOT BE SURPRISED IF HIGH TEMPERATURES TURN OUT A BIT COOLER SUNDAY THROUGH TUESDAY BEING ON THE COOL SIDE OF THE SYSTEM. ALREADY BLENDED SOME COOLER GUIDANCE READINGS INTO THE ALLBLEND TO BEGIN A SLOW TREND TO REFLECT THIS THINKING. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 626 PM CDT TUE MAY 6 2014 MAIN CONCERN FOR THE NEXT 24 H IS PRIMARY LOW CLOUDS. CURRENTLY LOWEST CEILINGS ARE AROUND KHON AT 5000 FT. AS THE WARM FRONT MOVES NORTH AND CONVERGENCE ALONG THE FRONT INCREASES...EXPECT SOME STRATUS TO FORM FIRST AROUND KSUX AND THEN TOWARD KFSD EARLY WEDNESDAY MORNING. AT THIS POINT...WITH MOISTURE RATHER LIMITED...KEPT CIGS AROUND 2000 FT FOR ONLY A FEW HOURS AT KSUX AND KFSD. EXPECT THAT THE SAME LOW CLOUDS WILL MOVE INTO KHON LATER TOMORROW AFTERNOON. AS FOR THUNDERSTORMS...AT THIS POINT...EXPECTATION IS THAT STORMS WILL PRIMARILY BE NORTHEAST OF KSUX AND WEST OF KHON. THERE COULD BE AN ISOLATED STORM OVERNIGHT AROUND KSUX. A LITTLE BIT BETTER CHANCE IN KHON LATE WEDNESDAY AFTERNOON BUT AT THIS POINT...THE CHANCE IS TOO LOW TO PUT INTO THE TAF. WINDS AT ALL THREE SITES WILL BACK TO NORTHEAST OVERNIGHT. AS THE WARM FRONT MOVES GOES THROUGH KSUX TOMORROW AFTERNOON...EXPECT THAT WINDS WILL VEER BACK TO SOUTHEAST. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE... SHORT TERM...JM LONG TERM...MJ AVIATION...SCHUMACHER
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
633 PM CDT TUE MAY 6 2014 .AVIATION... /00Z TAFS/ Stratus with MVFR CIGS returns along the I-10 corridor around 9Z and spreads northward. A few patches of stratus may affect KSJT, but most should stay south. Winds will increase mid morning and further increase late afternoon as lee trough strengthens. Isolated dryline thunderstorm possible late Wednesday afternoon, but coverage too low to put TAFS. && .PREV DISCUSSION... /ISSUED 357 PM CDT TUE MAY 6 2014/ SHORT TERM... (Tonight and Wednesday) Expect hot and dry weather this afternoon and a chance of thunderstorms Wednesday afternoon. A dryline was located along a Fredrick, OK to Abilene to Sonora line at 20Z. Latest SPC mesoanaylsis indicates weak instability(MLCAPES 500 to 1000 J/KG) ahead of the dryline over the eastern part of our area. The remaining convective inhibition or low level inversion may be erased for isolated storms to develop mainly after 22Z across the northern Heartland and eastern Big Country. the HRRR convective allowing model has been showing isolated storms developing the past several hourly runs. High LCLs and an inverted-v sounding profiles favor strong gusty winds and hail with the stronger storms. Also, storms will produce dangerous cloud to ground lightning. Any storms that do develop will exit the area or quickly dissipate by 02Z. The rest of tonight will see low level southerly flow and low level moisture returning. The dryline will retreat to just west of our area by 12Z Wednesday. Lows tonight will be in the 60s to around 70. For Wednesday, the morning looks quiet with low clouds across much of the area. Low clouds will break up across much of the area by early afternoon. Aloft, a strong upper level trough will be located over the southern Rockies. A dryline will move slowly east to along a Haskell to San Angelo line by late in the afternoon. Low level convergence along the dryline and increasing large scale ascent from approaching trough will cause isolated to scattered thunderstorms to develop across much of West Central Texas mainly after 20Z. The combination of some instability(MLCAPES of 1500 to 2000 J/KG) and 0-6KM bulk shear of 45 to 50 knots, will result in some storms being severe. The main threats will be large hail, damaging winds and dangerous cloud to ground lightning. Highs will be 90 to 95. LONG TERM... (Wednesday night through next Tuesday) By Wednesday night, the large upper level trough currently near Las Vegas will be moving east through the desert southwest toward west Texas. This feature will bring synoptic scale upward motion with it into west and west central Texas from Wednesday evening into Thursday. Have generally bumped PoPs up again with this forecast, as we get closer to the event, and become more confident in thunderstorms taking place. In addition, have added the mention of severe thunderstorms to the forecast for Wednesday evening, carrying over the mention from the afternoon. With 0-6km bulk shear values of 40-55 knots, and SFC and mixed layer CAPE values ranging from near 1000 J/kg to as high as 1500 J/kg, there will be enough instability, and storm organization carried over into the evening hours for the threat of severe weather to be possible. As with the previous period, the main concerns will be large hail and damaging winds. As the event evolves overnight, the instability will wane, and thus have the mention of severe weather in the forecast only through 06Z. In addition to the severe weather possibility, some of the thunderstorms will contain heavy rainfall, and localized flooding will be possible, mainly in urban areas. On Thursday, we will likely continue to see a broken line of showers with embedded thunderstorms for the eastern half of the area, especially during the morning hours as steering flow remain southwest, making the exit of precipitation a little slow. Severe weather concern will be limited with this mainly morning activity. One more weak shortwave will move through the area Friday afternoon and evening, possibly providing one more shot at precipitation for southeastern areas Friday afternoon and night. Expect temperatures to continue to be above normal through the forecast period. Thursday and Friday will be the cooler days averaging mainly in the upper 80s to lower 90s. Temperatures will quickly warm back into the mid 90s for the weekend. Have not made any significant changes beyond the end of this week as there is still a lot of uncertainty associated with the forecast for early next week. The GFS is much more progressive and weaker with an upper level system, sending a cold front into the area Sunday night whereas the ECMWF is slower and stronger, and waits until Monday evening to send a cold front into the area. FIRE WEATHER... Critical fire weather conditions are expected this afternoon and early evening, generally west of a Haskell to Bronte line. A Red Flag Warning is in effect until 9 PM across the western Big Country and Northern Concho Valley due to RH values of 7 to 12 percent and southwest winds around 20 mph. Also, ERC values are at record levels across this area. An increase in low level moisture late tonight should result in RH values recovering to 60 to 80 percent across much of West Central Texas. Elevated fire weather conditions are expected Wednesday afternoon west of a Haskell to Ozona line due to RH values of 15 to 25 percent and wind speeds of 15 mph. Thunderstorms will bring potential wetting rains across mainly northern and eastern areas Wednesday night and Thursday. && .PRELIMINARY POINT TEMPS/POPS... Abilene 71 94 67 87 61 / 5 30 50 30 10 San Angelo 68 94 68 91 57 / 5 20 40 20 10 Junction 64 91 70 87 66 / 10 20 50 40 10 && .SJT WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING until 9 PM CDT this evening FOR THE FOLLOWING ZONES: Coke...Fisher...Haskell...Jones...Nolan...Sterling... Taylor. && $$ 21/04
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
920 PM EDT TUE MAY 6 2014 .SYNOPSIS... A FRONT WILL REMAIN STALLED ACROSS OUR REGION TONIGHT THROUGH WEDNESDAY. AN UPPER RIDGE WILL BUILD OVER THE REGION THURSDAY... RESULTING IN WARMER AND DRIER CONDITIONS. HIGH PRESSURE WILL GIVE WAY TO A SLOW MOVING FRONTAL SYSTEM LATE FRIDAY INTO SATURDAY. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 900 PM EDT TUESDAY... EVENING RNK SOUNDING SHOWING QUITE A BIT OF LOW LEVEL INSTABILITY WITH CAPES NEAR 2K BEING CAPPED ALOFT VIA A DECENT INVERSION JUST ABOVE 7H. HOWEVER LOW LEVELS REMAIN DRY WITH BETTER SURFACE COOLING ONGOING AS THE EASTERLY FLOW HAS NOW FLOPPED BACK TO AS FAR WEST AS THE BLUE RIDGE. IN ADDITION...SUPPORT ALOFT LACKING ATTM TO ERODE THE CAP ...WHILE THE SURFACE BOUNDARY REMAINS TO THE SW WHERE THE AIR REMAINS ARID ON THE WEST SIDE OF THE FRONT OVER THE NW NC RIDGES. THUS LITTLE TO TRIGGER CONVECTION THERE. HOWEVER DEWPOINTS LOOK TO SLOWLY RECOVER NORTHWARD EAST OF THE BLUE RIDGE OVERNIGHT WITH A WEAK IMPULSE SLIDING ACROSS LATE IN THE NW FLOW ALOFT. MODELS REMAIN OVERDONE WITH CONVECTION BUT APPEARS A WINDOW POSSIBLE DURING THE NEXT FEW HOURS INTO THE EARLY MORNING HOURS OVER THE FAR NORTH TO SEE A FEW BANDS OF SHRA/TSRA WITH THIS FAINT FEATURE. GIVEN CURRENT LACK OF COVERAGE BASICALLY REMOVED POPS EARLY THIS EVENING...AND CUT BACK TO MOSTLY ISOLATED TO CHANCE COVERAGE NORTH OF HIGHWAY 460 DURING THE OVERNIGHT. OTRW EXPECT LOW CLOUDS TO FILL BACK IN ESPCLY EAST AS THE WEDGE DEEPENS AGAIN WITH MAINLY CLEAR SKIES OVER THE WEST/SW. SOME PATCHY FOG ALSO POSSIBLE OUT EAST AND IN THE VALLEYS BUT QUITE SPOTTY. ADJUSTED LOWS DOWN SOME BLUE RIDGE EAST PER EASTERLY FLOW AND BUMPED UP WEST GIVEN SLOW TO FALL READINGS AND MORE OF A LIGHT WEST WIND THROUGH DAYBREAK. UPDATE AS OF 630 PM EDT TUESDAY... EARLY UPDATE TO REMOVE GOING POPS ACROSS THE REGION INTO THIS EVENING GIVEN LOW LEVEL DRY AIR IN PLACE PER OBS/MSAS AND LACK OF MUCH CONVERGENCE OR SHRA. STILL POTENTIAL FOR ISOLATED COVERAGE TO BREAK THE CAP ALOFT SEEN OFF EARLIER SOUNDINGS BUT CURRENT CLOUD FIELDS AND LATEST MODELS SUGGEST MAY BE LATER WHEN A WEAK IMPULSE ALOFT RIDES IN FROM THE NW. OTRW STILL SEEING QUITE A SPREAD IN TEMPS FROM THE WEDGING IN THE NE TO THE VERY WARM TEMPS OVER THE SW WHERE THE AIR IS VERY DRY PER HUMIDITY LEVELS BELOW 20 PERCENT. WILL LEAVE IN CURRENT CHANCE POPS AFTER SUNSET WHEN MAY SEE MOISTURE POOL ALONG THE BLUE RIDGE OTRW RUNNING DRY OVER THE NEXT COUPLE OF HOURS PER THE LASTEST HRRR. PREVIOUS DISCUSSION AS OF 330 PM EDT TUESDAY... FRONTAL BOUNDARY REMAINS ACROSS REGION THROUGH TONIGHT. SHORTWAVE COMES OVER UPPER RIDGE INTO THE FORECAST AREA LATE TONIGHT. DESPITE SOLAR HEATING...STRONG CAP THIS AFTERNOON HINDERING CONVECTION DEVELOPMENT. WEAK DPVA ASSOCIATED WITH SHORTWAVE MAY BE ABLE TO OVERCOME THE HEALTHY CAP. LIKE YESTERDAY...SWODY1 ADDED THE MENTION OF A SEE TEXT FOR ISOLATED SEVERE THUNDERSTORMS WITH A HAIL AND WIND THREAT FOR VIRGINIA. MODIFIED FCST SOUNDINGS SUGGEST RELATIVELY COLD AIR ALOFT AND GOOD LAPSE RATES FOR THIS AFTERNOON INTO TONIGHT. RNK WRFARW DEVELOPS SOME CONVECTION THIS AFTERNOON ACROSS THE NORTH TO NORTHEAST CORNER OF CWA AND DROP SOUTHEAST. HRRR SHOWED SOME ISOLATED CONVECTION ACROSS THE NORTH THIS EVENING INTO TONIGHT. GFS AND ECMWF STILL SHOWING SCATTERED CONVECTION ACROSS THE NORTH WITH WAA TONIGHT. WILL KEEP ISOLATED TO SCATTERED CONVECTION IN FOR THIS EVENING INTO TONIGHT ACROSS THE NORTH. BUT...HAVE CONCERNS THAT CAP MAY HOLD AND LIMITED CONVECTION. PLAYED LOW TEMPERATURES CLOSE TO ADJMAVBC WITH READINGS FROM LOWER 50S IN THE NORTHERN MOUNTAINS TO THE UPPER 50S IN THE PIEDMONT. THE H8 WARN FRONT LIFTS NORTH ON WEDNESDAY. BEST LIFT AND INSTABILITY IS ACROSS THE NORTH FOR WEDNESDAY. GOOD LAPSE RATE AND ELEVATED INSTABILITY SUPPORT MENTION OF SHOWERS AND ISOLATED ACROSS THE NORTH. FLOW BECOME SOUTHERLY IN THE SOUTH ON WEDNESDAY AND CAP IS EVEN STRONGER...ELECTED TO KEEP MENTION OF STORMS OUT OF SOUTHERN PORTIONS OF FA. HIGH TEMPERATURES ON WEDNESDAY CHALLENGING FOR THE NORTHEASTERN THIRD OF THE CWA WITH CLOUDS AND POTENTIAL CONVECTION. HIGH TEMPERATURES ON WEDNESDAY WILL VARY FROM AROUND 70 IN THE NORTH TO THE LOWER TO MID 80S IN THE FAR SOUTHWEST AND ALONG THE FOOTHILLS OF THE SOUTHERN BLUE RIDGE MOUNTAINS. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... AS OF 330 PM EDT TUESDAY... TEMPERATURES WELL ABOVE NORMAL TO FINISH OFF THE WORK WEEK. HIGH AMPLITUDE UPPER LEVEL FLOW WILL SUBJECT FORECAST AREA TO A SURGE OF VERY WARM AIR THURSDAY AND FRIDAY. AN UPPER LEVEL RIDGE OF HIGH PRESSURE IS EXPECTED TO AMPLIFY INTO THE 582 TO 588 DECAMETER RANGE OVER THE EASTERN CONUS...AXIS RUNNING NORTH-SOUTH FROM ONTARIO CANADA TO FLORIDA. THE GREATEST AMPLITUDE IS EXPECTED THURSDAY... THEN BREAKING DOWN FRIDAY AS A MID CONUS TROF MOVES EAST. 850 MB TEMPS THURSDAY ARE PROGGED NEAR 18 DEG C. THIS ALONE WILL PROMOTE TEMPERATURES WELL INTO THE 80S. AN ADDED BOOST WILL OCCUR FROM ADIABATIC WARMING...WESTERLY WINDS RESULTING IN COMPRESSIONAL HEATING AS THE AIR PASSES OVER AND DOWN THE MTNS. THE NET EFFECT WILL BE TEMPERATURES WHICH WILL TEST THE 90 DEGREE MARK ON THE EAST SIDE OF THE MOUNTAINS THURSDAY...AND TO A LESSER DEGREE FRIDAY AS THE WINDS BACK MORE TOWARD THE SOUTHWEST AHEAD OF THE APPROACHING MID CONUS TROUGH. STRONG SUBSIDENCE THURSDAY WILL SQUELCH ANY CHANCE OF SHOWER ACTIVITY YIELDING A MOSTLY SUNNY DAY. AS THE SUBSIDENCE WEAKENS FRIDAY...SHOULD SEE A BIT MORE CUMULUS...BUT THINK ANY THREAT OF SHOWER OR STORM ACTIVITY WILL HOLD OFF UNTIL LATE UNLESS AN OUTFLOW BOUNDARY MOVES EAST OF THE MAIN MID CONUS FRONT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 330 PM EDT TUESDAY... VARIABILITY IN THE MODELS LEADS TO A LOW CONFIDENCE FORECAST... ESPECIALLY NEXT WEEK. SATURDAY IS THE ONLY DAY WHERE THE MODELS REMOTELY LOOK SIMILAR...THEN THEY DIVERGE RESULTING IN DIFFERING SOLUTIONS FOR SUNDAY THROUGH TUESDAY. THE GFS IS PROGRESSIVE AND AND FAVORS ZONAL FLOW ALOFT NEXT WEEK VS. THE MORE AMPLIFIED ECMWF. FOR SATURDAY BOTH MODELS BRING SURGE OF MOISTURE INTO THE AREA AHEAD OF APPROACHING SURFACE FRONT. THIS RESULTS IN LIKELIHOOD OF SHOWERS AND POSSIBLE THUNDERSTORMS...ESP ACROSS THE MOUNTAINS. THE GFS THEN PUSHES THE FRONT THROUGH THE AREA QUICKLY WITH ANOTHER FRONT COMING THROUGH ABOUT TUESDAY. THE ECMWF SLOWS SATURDAYS FRONT WITH TROUGHING LINGERING THROUGH THE WEEKEND...FOLLOWED BY HIGHER AMPLITUDE RIDGING ALOFT EARLY NEXT WEEK WITH THE SURFACE FRONT GETTING CAUGHT UNDERNEATH THE RIDGE. THIS RESULTS IN A WETTER SOLUTION THIS WEEKEND FOLLOWED BY A DAY OR TWO OF EASTERLY LOW LEVEL FLOW MONDAY AND TUESDAY UNTIL WE MIX OUT THE MIDDLE OF NEXT WEEK. SINCE THE CURRENT PATTERN FAVORS A MORE AMPLIFIED SOLUTION WILL ENTERTAIN A FORECAST CLOSER TO THE ECMWF. AS SUCH TRENDED THE FORECAST CLOUDIER AND COOLER TO START THE WEEK...TEMPERATURES MONDAY AND TUESDAY CLOSER TO NORMAL ALONG WITH A CHANCE OF SHOWERS. BY MID WEEK...FLOW ALOFT SHOULD BECOME SOUTHWEST WITH ANOTHER WARM SURGE PRIOR TO ANY FRONTAL PASSAGE IN THE WEDNESDAY...THURSDAY TIME FRAME. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... AS OF 635 PM EDT TUESDAY... FRONTAL BOUNDARY WILL REMAIN NEARLY STATIONARY ACROSS THE EXTREME SW PORTION OF THE REGION AGAIN TONIGHT. WINDS TONIGHT WILL BE MAINLY FROM THE EAST/NE EAST OF THE MOUNTAINS AND WEST TO SW TO THE WEST. HOWEVER AS THE WEDGE ENHANCES AFTER DARK SHOULD SEE THE FLOW TURN MORE EASTERLY AGAIN OVERNIGHT INTO EARLY WEDNESDAY. FRONT REMAINS LOCKED IN ATTM WITH MORE OF A LOW LEVEL WEDGE STUCK OVER THE EAST. LACK OF MUCH UPPER SUPPORT SUGGESTS ANY CONVECTION WILL BE ISOLATED AT THIS POINT BUT MAY INCREASE SOME LATER TONIGHT AS ANOTHER MID LEVEL WAVE JETS IN FROM THE NW. OTRW LOW CLOUDS AND FOG THE MAIN ISSUES AGAIN OVERNIGHT AS THE WEDGE FLOPS BACK TO THE WEST BY MORNING. GIVEN LOW CONFIDENCE IN SEEING IFR/LIFR CIGS AS SUGGESTED BY SOME GUIDANCE...LEFT IN OVERALL MVFR CIGS OUT EAST...WITH AN EARLY MORNING TEMPO GROUP SUGGESTING A PERIOD OF IFR WITH MVFR/IFR FOG AS WELL EAST OF KBLF. THE FRONT WILL START TO DRIFT BACK EAST AS A WARM FRONT LATER WEDNESDAY BUT LIKELY REMAIN OVER THE MOUNTAINS INTO WEDNESDAY EVENING. THIS WILL RESULT IN A PERSISTENT EASTERLY FLOW THAT WILL GRADUALLY TURN MORE SOUTH AND SE BY WEDNESDAY AFTERNOON. THIS MAY RESULT IN A MORE WIDESPREAD CANOPY OF LOWER CIGS ESPCLY ALONG THE BLUE RIDGE EARLY WEDNESDAY WITH SLOW IMPROVEMENT TO VFR BY WEDNESDAY AFTERNOON AS THE FLOW TURNS MORE SOUTHERLY. ISOLATED SHRA/TSRA AGAIN POSSIBLE ON WEDNESDAY AS THE BOUNDARY FINALLY STARTS TO LIFT NORTH BUT IFFY AT THIS POINT SO LEAVING OUT ANY SHRA/TSRA MENTION WEDNESDAY. THURSDAY...THE FRONT LIFTS TO THE NORTH WITH WARMER AIR ALOFT PUTTING A CAP ON ANY CONVECTION UNDER VFR CU FIELDS. BY LATE FRIDAY A COLD FRONT WILL APPROACH FROM THE WEST...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS DURING THE EVENING. BETTER CHANCE FOR SUB-VFR AT TIMES SAT AFTERNOON/EVENING WITH THE FRONT SLOWLY MOVING EAST AND DEEPER MOISTURE IN PLACE. BOUNDARY MAY WASH OUT UPON CROSSING THE AREA BY SUNDAY WITH MAINLY VFR CONDITIONS EXPECTED OUTSIDE OF OCNL MVFR IN SCATTERED AFTERNOON/EVENING SHRA. && .CLIMATE... HIGH TEMPERATURE RECORDS IN THE MOUNTAINS ARE IN JEOPARDY THURSDAY. MAY GET CLOSE IN THE EAST. CURRENT RECORDS FOR MAY 8TH... ROANOKE......94/1940 LYNCHBURG....94/1940 DANVILLE.....92/1986 BLACKSBURG...85/2000 BLUEFIELD....84/2004 LEWISBURG....82/2000 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...KK NEAR TERM...JH/KK SHORT TERM...PM LONG TERM...PM AVIATION...AMS/JH/KK CLIMATE...PM
AREA FORECAST DISCUSSION...UPDATED
NWS BLACKSBURG VA
657 PM EDT TUE MAY 6 2014 .SYNOPSIS... A FRONT WILL REMAIN STALLED ACROSS OUR REGION TONIGHT THROUGH WEDNESDAY. AN UPPER RIDGE WILL BUILD OVER THE REGION THURSDAY... RESULTING IN WARMER AND DRIER CONDITIONS. HIGH PRESSURE WILL GIVE WAY TO A SLOW MOVING FRONTAL SYSTEM LATE FRIDAY INTO SATURDAY. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 630 PM EDT TUESDAY... EARLY UPDATE TO REMOVE GOING POPS ACROSS THE REGION INTO THIS EVENING GIVEN LOW LEVEL DRY AIR IN PLACE PER OBS/MSAS AND LACK OF MUCH CONVERGENCE OR SHRA. STILL POTENTIAL FOR ISOLATED COVERAGE TO BREAK THE CAP ALOFT SEEN OFF EARLIER SOUNDINGS BUT CURRENT CLOUD FIELDS AND LATEST MODELS SUGGEST MAY BE LATER WHEN A WEAK IMPULSE ALOFT RIDES IN FROM THE NW. OTRW STILL SEEING QUITE A SPREAD IN TEMPS FROM THE WEDGING IN THE NE TO THE VERY WARM TEMPS OVER THE SW WHERE THE AIR IS VERY DRY PER HUMIDITY LEVELS BELOW 20 PERCENT. WILL LEAVE IN CURRENT CHANCE POPS AFTER SUNSET WHEN MAY SEE MOISTURE POOL ALONG THE BLUE RIDGE OTRW RUNNING DRY OVER THE NEXT COUPLE OF HOURS PER THE LASTEST HRRR. PREVIOUS DISCUSSION AS OF 330 PM EDT TUESDAY... FRONTAL BOUNDARY REMAINS ACROSS REGION THROUGH TONIGHT. SHORTWAVE COMES OVER UPPER RIDGE INTO THE FORECAST AREA LATE TONIGHT. DESPITE SOLAR HEATING...STRONG CAP THIS AFTERNOON HINDERING CONVECTION DEVELOPMENT. WEAK DPVA ASSOCIATED WITH SHORTWAVE MAY BE ABLE TO OVERCOME THE HEALTHY CAP. LIKE YESTERDAY...SWODY1 ADDED THE MENTION OF A SEE TEXT FOR ISOLATED SEVERE THUNDERSTORMS WITH A HAIL AND WIND THREAT FOR VIRGINIA. MODIFIED FCST SOUNDINGS SUGGEST RELATIVELY COLD AIR ALOFT AND GOOD LAPSE RATES FOR THIS AFTERNOON INTO TONIGHT. RNK WRFARW DEVELOPS SOME CONVECTION THIS AFTERNOON ACROSS THE NORTH TO NORTHEAST CORNER OF CWA AND DROP SOUTHEAST. HRRR SHOWED SOME ISOLATED CONVECTION ACROSS THE NORTH THIS EVENING INTO TONIGHT. GFS AND ECMWF STILL SHOWING SCATTERED CONVECTION ACROSS THE NORTH WITH WAA TONIGHT. WILL KEEP ISOLATED TO SCATTERED CONVECTION IN FOR THIS EVENING INTO TONIGHT ACROSS THE NORTH. BUT...HAVE CONCERNS THAT CAP MAY HOLD AND LIMITED CONVECTION. PLAYED LOW TEMPERATURES CLOSE TO ADJMAVBC WITH READINGS FROM LOWER 50S IN THE NORTHERN MOUNTAINS TO THE UPPER 50S IN THE PIEDMONT. THE H8 WARN FRONT LIFTS NORTH ON WEDNESDAY. BEST LIFT AND INSTABILITY IS ACROSS THE NORTH FOR WEDNESDAY. GOOD LAPSE RATE AND ELEVATED INSTABILITY SUPPORT MENTION OF SHOWERS AND ISOLATED ACROSS THE NORTH. FLOW BECOME SOUTHERLY IN THE SOUTH ON WEDNESDAY AND CAP IS EVEN STRONGER...ELECTED TO KEEP MENTION OF STORMS OUT OF SOUTHERN PORTIONS OF FA. HIGH TEMPERATURES ON WEDNESDAY CHALLENGING FOR THE NORTHEASTERN THIRD OF THE CWA WITH CLOUDS AND POTENTIAL CONVECTION. HIGH TEMPERATURES ON WEDNESDAY WILL VARY FROM AROUND 70 IN THE NORTH TO THE LOWER TO MID 80S IN THE FAR SOUTHWEST AND ALONG THE FOOTHILLS OF THE SOUTHERN BLUE RIDGE MOUNTAINS. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... AS OF 330 PM EDT TUESDAY... TEMPERATURES WELL ABOVE NORMAL TO FINISH OFF THE WORK WEEK. HIGH AMPLITUDE UPPER LEVEL FLOW WILL SUBJECT FORECAST AREA TO A SURGE OF VERY WARM AIR THURSDAY AND FRIDAY. AN UPPER LEVEL RIDGE OF HIGH PRESSURE IS EXPECTED TO AMPLIFY INTO THE 582 TO 588 DECAMETER RANGE OVER THE EASTERN CONUS...AXIS RUNNING NORTH-SOUTH FROM ONTARIO CANADA TO FLORIDA. THE GREATEST AMPLITUDE IS EXPECTED THURSDAY... THEN BREAKING DOWN FRIDAY AS A MID CONUS TROF MOVES EAST. 850 MB TEMPS THURSDAY ARE PROGGED NEAR 18 DEG C. THIS ALONE WILL PROMOTE TEMPERATURES WELL INTO THE 80S. AN ADDED BOOST WILL OCCUR FROM ADIABATIC WARMING...WESTERLY WINDS RESULTING IN COMPRESSIONAL HEATING AS THE AIR PASSES OVER AND DOWN THE MTNS. THE NET EFFECT WILL BE TEMPERATURES WHICH WILL TEST THE 90 DEGREE MARK ON THE EAST SIDE OF THE MOUNTAINS THURSDAY...AND TO A LESSER DEGREE FRIDAY AS THE WINDS BACK MORE TOWARD THE SOUTHWEST AHEAD OF THE APPROACHING MID CONUS TROUGH. STRONG SUBSIDENCE THURSDAY WILL SQUELCH ANY CHANCE OF SHOWER ACTIVITY YIELDING A MOSTLY SUNNY DAY. AS THE SUBSIDENCE WEAKENS FRIDAY...SHOULD SEE A BIT MORE CUMULUS...BUT THINK ANY THREAT OF SHOWER OR STORM ACTIVITY WILL HOLD OFF UNTIL LATE UNLESS AN OUTFLOW BOUNDARY MOVES EAST OF THE MAIN MID CONUS FRONT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 330 PM EDT TUESDAY... VARIABILITY IN THE MODELS LEADS TO A LOW CONFIDENCE FORECAST... ESPECIALLY NEXT WEEK. SATURDAY IS THE ONLY DAY WHERE THE MODELS REMOTELY LOOK SIMILAR...THEN THEY DIVERGE RESULTING IN DIFFERING SOLUTIONS FOR SUNDAY THROUGH TUESDAY. THE GFS IS PROGRESSIVE AND AND FAVORS ZONAL FLOW ALOFT NEXT WEEK VS. THE MORE AMPLIFIED ECMWF. FOR SATURDAY BOTH MODELS BRING SURGE OF MOISTURE INTO THE AREA AHEAD OF APPROACHING SURFACE FRONT. THIS RESULTS IN LIKELIHOOD OF SHOWERS AND POSSIBLE THUNDERSTORMS...ESP ACROSS THE MOUNTAINS. THE GFS THEN PUSHES THE FRONT THROUGH THE AREA QUICKLY WITH ANOTHER FRONT COMING THROUGH ABOUT TUESDAY. THE ECMWF SLOWS SATURDAYS FRONT WITH TROUGHING LINGERING THROUGH THE WEEKEND...FOLLOWED BY HIGHER AMPLITUDE RIDGING ALOFT EARLY NEXT WEEK WITH THE SURFACE FRONT GETTING CAUGHT UNDERNEATH THE RIDGE. THIS RESULTS IN A WETTER SOLUTION THIS WEEKEND FOLLOWED BY A DAY OR TWO OF EASTERLY LOW LEVEL FLOW MONDAY AND TUESDAY UNTIL WE MIX OUT THE MIDDLE OF NEXT WEEK. SINCE THE CURRENT PATTERN FAVORS A MORE AMPLIFIED SOLUTION WILL ENTERTAIN A FORECAST CLOSER TO THE ECMWF. AS SUCH TRENDED THE FORECAST CLOUDIER AND COOLER TO START THE WEEK...TEMPERATURES MONDAY AND TUESDAY CLOSER TO NORMAL ALONG WITH A CHANCE OF SHOWERS. BY MID WEEK...FLOW ALOFT SHOULD BECOME SOUTHWEST WITH ANOTHER WARM SURGE PRIOR TO ANY FRONTAL PASSAGE IN THE WEDNESDAY...THURSDAY TIME FRAME. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 635 PM EDT TUESDAY... FRONTAL BOUNDARY WILL REMAIN NEARLY STATIONARY ACROSS THE EXTREME SW PORTION OF THE REGION AGAIN TONIGHT. WINDS TONIGHT WILL BE MAINLY FROM THE EAST/NE EAST OF THE MOUNTAINS AND WEST TO SW TO THE WEST. HOWEVER AS THE WEDGE ENHANCES AFTER DARK SHOULD SEE THE FLOW TURN MORE EASTERLY AGAIN OVERNIGHT INTO EARLY WEDNESDAY. FRONT REMAINS LOCKED IN ATTM WITH MORE OF A LOW LEVEL WEDGE STUCK OVER THE EAST. LACK OF MUCH UPPER SUPPORT SUGGESTS ANY CONVECTION WILL BE ISOLATED AT THIS POINT BUT MAY INCREASE SOME LATER TONIGHT AS ANOTHER MID LEVEL WAVE JETS IN FROM THE NW. OTRW LOW CLOUDS AND FOG THE MAIN ISSUES AGAIN OVERNIGHT AS THE WEDGE FLOPS BACK TO THE WEST BY MORNING. GIVEN LOW CONFIDENCE IN SEEING IFR/LIFR CIGS AS SUGGESTED BY SOME GUIDANCE...LEFT IN OVERALL MVFR CIGS OUT EAST...WITH AN EARLY MORNING TEMPO GROUP SUGGESTING A PERIOD OF IFR WITH MVFR/IFR FOG AS WELL EAST OF KBLF. THE FRONT WILL START TO DRIFT BACK EAST AS A WARM FRONT LATER WEDNESDAY BUT LIKELY REMAIN OVER THE MOUNTAINS INTO WEDNESDAY EVENING. THIS WILL RESULT IN A PERSISTENT EASTERLY FLOW THAT WILL GRADUALLY TURN MORE SOUTH AND SE BY WEDNESDAY AFTERNOON. THIS MAY RESULT IN A MORE WIDESPREAD CANOPY OF LOWER CIGS ESPCLY ALONG THE BLUE RIDGE EARLY WEDNESDAY WITH SLOW IMPROVEMENT TO VFR BY WEDNESDAY AFTERNOON AS THE FLOW TURNS MORE SOUTHERLY. ISOLATED SHRA/TSRA AGAIN POSSIBLE ON WEDNESDAY AS THE BOUNDARY FINALLY STARTS TO LIFT NORTH BUT IFFY AT THIS POINT SO LEAVING OUT ANY SHRA/TSRA MENTION WEDNESDAY. THURSDAY...THE FRONT LIFTS TO THE NORTH WITH WARMER AIR ALOFT PUTTING A CAP ON ANY CONVECTION UNDER VFR CU FIELDS. BY LATE FRIDAY A COLD FRONT WILL APPROACH FROM THE WEST...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS DURING THE EVENING. BETTER CHANCE FOR SUB-VFR AT TIMES SAT AFTERNOON/EVENING WITH THE FRONT SLOWLY MOVING EAST AND DEEPER MOISTURE IN PLACE. BOUNDARY MAY WASH OUT UPON CROSSING THE AREA BY SUNDAY WITH MAINLY VFR CONDITIONS EXPECTED OUTSIDE OF OCNL MVFR IN SCATTERED AFTERNOON/EVENING SHRA. && .CLIMATE... HIGH TEMPERATURE RECORDS IN THE MOUNTAINS ARE IN JEOPARDY THURSDAY. MAY GET CLOSE IN THE EAST. CURRENT RECORDS FOR MAY 8TH... ROANOKE......94/1940 LYNCHBURG....94/1940 DANVILLE.....92/1986 BLACKSBURG...85/2000 BLUEFIELD....84/2004 LEWISBURG....82/2000 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...KK NEAR TERM...AMS/JH/KK SHORT TERM...PM LONG TERM...PM AVIATION...AMS/JH/KK CLIMATE...PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
215 PM EDT MON MAY 5 2014 .SYNOPSIS... A WEAK FRONT TRAILED FROM MISSOURI TO SOUTHWEST VIRGINIA AND INTO NORTHERN NORTH CAROLINA. LITTLE CHANGE IN THIS WEATHER PATTERN IS EXPECTED THROUGH WEDNESDAY. AN UPPER RIDGE WILL BUILD OVER THE REGION THURSDAY...RESULTING IN WARMER...DRIER CONDITIONS. HIGH PRESSURE WILL GIVE WAY TO A SLOW MOVING FRONTAL SYSTEM LATE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 130 PM EDT MONDAY... RAISED TEMPERATURES AND HIGH TEMPERATURES IN THE WEST TO MATCH UP BETTER WITH LATEST SFC OBS AND MODEL TRENDS. FOCUS OF CONVECTION ACROSS THE NORTH SIMILAR TO RNK WRFARW. CAP TO SOUTH IS HOLDING BACK DEVELOPMENT OF CONVECTION THIS AFTERNOON ACROSS SOUTHERN PORTIONS OF CWA. BETTER COVERAGE OF STORMS ACROSS THE NORTHERN PORTION OF FORECAST AREA. MORE CHANGES LATER THIS AFTERNOON. AS OF 935 AM EDT MONDAY... UPDATED POPS AND WEATHER TO MATCH UP WSR-88D TRENDS. IN GENERAL INCREASED POPS ACROSS THE NORTHERN HALF OF CWA FOR THIS MORNING INTO THIS AFTERNOON. THE NEW SWODY1 HAS PLACED SEE TEXT FOR PORTIONS OF CWA FOR THIS AFTERNOON WITH MAIN THREAT HAIL AND DAMAGING WIND. UPDATED HWO TO HIGHLIGHT STRONG TO SEVERE THUNDERSTORMS FOR THIS AFTERNOON. THE HRRR TAKES FIRST AREA OF CONVECTION SOUTHEAST OUT OF CWA...THEN A SECOND ROUND MOVE ACROSS NORTHERN PORTIONS OF CWA AFTER 18Z THIS AFTERNOON UNTIL 23Z THIS EVENING. THE LOCAL RNKWRFARW KEPT ISOLATED TO SCATTERED CONVECTION ACROSS THE NORTH MAINLY NORTH OF INTERSTATE 64. THE NAM AND GFS PLACED ADDITIONAL CONVECTION ACROSS THE WEST THIS AFTERNOON INTO THIS EVENING. ELECTED TO PLACED HIGHEST POP ACROSS THE NORTH AND ADD MENTION OF THUNDERSTORM FURTHER SOUTH. WILL GIVE FORECAST HIGHS A CHANCE...BUT ADDITIONAL CLOUD COVER MAY COOL HIGHS. MORE CHANGES LATER... AS OF 400 AM EDT MONDAY... LINE OF SHOWERS WAS PARALLEL TO AND NORTH OF A STATIONARY FRONT. THE SHOWERS WERE LINED UP FROM NORTH OF INDIANAPOLIS TO SOUTH OF COLUMBUS TO NORTH OF CHARLESTON WV. THE ACTUAL FRONT EXTENDED FROM NEAR ST. LOUIS TO SOUTHERN VIRGINIA. LITTLE CHANGE IS EXPECTED IN THE POSITION AND ORIENTATION OF THE FRONT AND BAROCLINIC ZONE TODAY AND TONIGHT SINCE THEY WILL BE PARALLEL TO THE UPPER FLOW THROUGH THIS TIME FRAME. RAP AND NAM GUIDANCE HAVE REASONABLE PLACEMENT OF AXIS OF PRECIPITATION THROUGH TONIGHT. EAST END OF THE FRONT WILL PUSH FARTHER SOUTH IN TO NORTH CAROLINA THIS MORNING WITH A POCKET OF COOLER AND MORE STABLE AIR JUST BEHIND IT. THIS WAS REFLECTED IN THE BUFKIT SOUNDINGS WHICH SHOWED A MID LEVEL CAP AT DANVILLE AND LYNCHBURG TODAY WITH MORE SURFACE BASED INSTABILITY AND CAPE IN THE MOUNTAINS. WITH THE DEEP NORTHWEST FLOW ASIDE FROM NEAR THE SURFACE...ANY SHOWERS AND THUNDERSTORMS WILL ENCOUNTER SUBSIDENCE EAST OF THE BLUE RIDGE. BEST PROBABILITY OF PRECIPITATION WILL BE IN THE NORTHWEST PART OF THE COUNTY WARNING AREA. NOT MUCH CHANGE IN AIR MASS FROM SUNDAY ABOVE THE BOUNDARY LAYER. 850 MB TEMPERATURES REMAIN ABOUT THE SAME BUT MUCH OF FORECAST AREA IS ON THE COOLER SIDE OF THE FRONT AND THERE WILL BE MORE CLOUD COVER IN THE NORTHERN COUNTY WARNING AREA TODAY SO MAXIMUM TEMPERATURES WILL BE CLOSER TO NORMAL. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... AS OF 330 AM EDT MONDAY... WEAK BOUNDARY REMAINS IN THE REGION THROUGH WEDNESDAY...BUT LIKE THE PAST FEW DAYS...THERE REMAINS NO TRIGGER FOR WIDESPREAD OR EVEN SCATTERED SHOWERS/THUNDERSTORMS. MODEL SOUNDINGS CONTINUE TO FORECAST DEWPOINTS/MOISTURE THAT DOES NOT FIT CURRENT OBSERVATIONS AND PWATS. KEPT ONLY SLT CHC POPS CONSIDERING THESE INCONSISTENCIES. WEAK SURFACE HIGH PRESSURE JUST SOUTH OF THE DELMARVA ON TUESDAY...SHOULD KEEP AN EASTERLY SURFACE BREEZE AND REINFORCE SLIGHTLY COOLER TEMPS...EXCEPT FOR EXTREME SW VA. THIS IS ONLY TEMPORARY AS A PESKY BOUNDARY MOVES BACK NORTH AS A WARM FRONT LATE WEDNESDAY. WAA WITH H85 TEMPS NEAR +18C COULD PUSH THE CITIES TO 90F THURSDAY. HOWEVER THE ECMWF IS DECIDEDLY COOLER...SO HOLDING OFF FOLLOWING THE HOT MEX MOS UNTIL THE MAX T SPREAD BETWEEN THE ECMWF AND GFS LESSENS. ATTM...WOULD LEAN TOWARDS THE WARMER VALUES OF THE MEX AT THE END OF THE SHORT TERM PERIOD. && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 350 PM EDT SATURDAY... NOTABLE DIFFERENCES EXHIBITED AMONG THE GFS AND ECMWF. THE GFS SHIFTS THE CENTRAL U.S. UPPER TROUGH INTO THE REGION FRI...BUT HOLDS A BROAD UPPER TROUGH AND CONSIDERABLE ENERGY BACK TO THE WEST...WHICH QUICKLY EVOLVES INTO ANOTHER DEEP UPPER TROUGH AFFECTING THE REGION BY SUN-MON. THE ECMWF SHEARS OUT THE FIRST TROUGH THROUGH THE OH VALLEY/NE U.S...THEN BRINGS THE MAIN TROUGH INTO THE REGION LATE IN THE WEEKEND/EARLY NEXT WEEK. CONSEQUENTLY...THE MODELS PRESENT COMPLETELY DIFFERENT SOLUTIONS WITH RESPECT TO TIMING OF SHRA/TSRA. HAVE CONTINUED WITH HIGH CHC- LOW LIKELY POPS FOR THE WESTERN AREAS SAT...THEN BROAD BRUSHED CHC POPS FOR SUN-MON UNTIL A CLEARER SOLUTION AND BETTER CONSISTENCY IS OBTAINED AMONG THE MODELS. THERE IS CLEARLY THE POTENTIAL FOR BONAFIDE WIDESPREAD RAINFALL SOMEWHERE IN THE FRI- MON TIME FRAME. CLOUD COVER AND INCREASED RAIN CHANCES WILL RESULT IN LOWER TEMPERATURES FRI INTO THE WEEKEND...ALTHOUGH THE PIEDMONT COULD REMAIN IN THE 80S YET FRIDAY. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 215 PM EDT MONDAY... FRONTAL BOUNDARY WILL REMAIN NEARLY STATIONARY ACROSS THE REGION DURING THE TAF PERIOD. WINDS TONIGHT MAY SHIFT DIRECTION PERIODICALLY AS THE FRONT WAVERS BACK AND FORTH ACROSS THE REGION. UNSTABLE AIR WILL DEVELOP SOUTH OF THE FRONT BY THIS AFTERNOON. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL LINE UP ALONG THE FRONT FROM ILLINOIS INTO VIRGINIA. BUFKIT SOUNDINGS SHOWED A CAP AT KDAN AND KLYH WHICH MAY SUPPRESS THE GROWTH OF SHOWERS AND THUNDERSTORMS TODAY BUT HAVE KEPT A BETTER CHANCE IN THE KBCB/KLWB/KBLF AND KROA TAFS THIS AFTERNOON INTO TONIGHT. CONVECTION IS LINING UP NICELY WITH LATEST RUN OF RNK WRFARW. THE GFS LOOKS OVERDONE WITH CONVECTION FOR THE NEW RIVER VALLEY...WITH STRONG CAP IN PLACE THIS AFTERNOON. THE NAM AND ECMWF HAD GOOD COVERAGE ACROSS THE NORTHERN HALF OF FORECAST AREA THIS AFTERNOON AND LIFT IT NORTH TONIGHT. MVFR CEILINGS AND VISIBILITIES ARE LIKELY WITH THE THUNDERSTORMS. COVERAGE OF SHOWERS AND THUNDERSTORMS WILL DIMINISH AROUND SUNSET. TUESDAY INTO WEDNESDAY...THE FRONT WILL REMAIN STALLED OVER THE FORECAST AREA RESULTING IN A PERSISTENT CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON AND EVENING. MVFR CONDITIONED SHOULD BE EXPECTED WITH ANY OF THE SHOWERS AND STORMS. MEDIUM CONFIDENCE IN VISIBILITY...CEILINGS AND WINDS DURING THE TAF PERIOD. THURSDAY THE FRONT LIFTS NORTH WITH DRIER WEATHER AND WARMER AIR MOVING INTO THE REGION. BY LATE FRIDAY A COLD FRONT WILL APPROACH FROM THE WEST...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...KM LONG TERM...RAB AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
951 AM EDT MON MAY 5 2014 .SYNOPSIS... A WEAK FRONT TRAILED FROM MISSOURI TO SOUTHWEST VIRGINIA AND INTO NORTHERN NORTH CAROLINA. LITTLE CHANGE IN THIS WEATHER PATTERN IS EXPECTED THROUGH WEDNESDAY. AN UPPER RIDGE WILL BUILD OVER THE REGION THURSDAY...RESULTING IN WARMER...DRIER CONDITIONS. HIGH PRESSURE WILL GIVE WAY TO A SLOW MOVING FRONTAL SYSTEM LATE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 935 AM EDT MONDAY... UPDATED POPS AND WEATHER TO MATCH UP WSR-88D TRENDS. IN GENERAL INCREASED POPS ACROSS THE NORTHERN HALF OF CWA FOR THIS MORNING INTO THIS AFTERNOON. THE NEW SWODY1 HAS PLACED SEE TEXT FOR PORTIONS OF CWA FOR THIS AFTERNOON WITH MAIN THREAT HAIL AND DAMAGING WIND. UPDATED HWO TO HIGHLIGHT STRONG TO SEVERE THUNDERSTORMS FOR THIS AFTERNOON. THE HRRR TAKES FIRST AREA OF CONVECTION SOUTHEAST OUT OF CWA...THEN A SECOND ROUND MOVE ACROSS NORTHERN PORTIONS OF CWA AFTER 18Z THIS AFTERNOON UNTIL 23Z THIS EVENING. THE LOCAL RNKWRFARW KEPT ISOLATED TO SCATTERED CONVECTION ACROSS THE NORTH MAINLY NORTH OF INTERSTATE 64. THE NAM AND GFS PLACED ADDITIONAL CONVECTION ACROSS THE WEST THIS AFTERNOON INTO THIS EVENING. ELECTED TO PLACED HIGHEST POP ACROSS THE NORTH AND ADD MENTION OF THUNDERSTORM FURTHER SOUTH. WILL GIVE FORECAST HIGHS A CHANCE...BUT ADDITIONAL CLOUD COVER MAY COOL HIGHS. MORE CHANGES LATER... AS OF 400 AM EDT MONDAY... LINE OF SHOWERS WAS PARALLEL TO AND NORTH OF A STATIONARY FRONT. THE SHOWERS WERE LINED UP FROM NORTH OF INDIANAPOLIS TO SOUTH OF COLUMBUS TO NORTH OF CHARLESTON WV. THE ACTUAL FRONT EXTENDED FROM NEAR ST. LOUIS TO SOUTHERN VIRGINIA. LITTLE CHANGE IS EXPECTED IN THE POSITION AND ORIENTATION OF THE FRONT AND BAROCLINIC ZONE TODAY AND TONIGHT SINCE THEY WILL BE PARALLEL TO THE UPPER FLOW THROUGH THIS TIME FRAME. RAP AND NAM GUIDANCE HAVE REASONABLE PLACEMENT OF AXIS OF PRECIPITATION THROUGH TONIGHT. EAST END OF THE FRONT WILL PUSH FARTHER SOUTH IN TO NORTH CAROLINA THIS MORNING WITH A POCKET OF COOLER AND MORE STABLE AIR JUST BEHIND IT. THIS WAS REFLECTED IN THE BUFKIT SOUNDINGS WHICH SHOWED A MID LEVEL CAP AT DANVILLE AND LYNCHBURG TODAY WITH MORE SURFACE BASED INSTABILITY AND CAPE IN THE MOUNTAINS. WITH THE DEEP NORTHWEST FLOW ASIDE FROM NEAR THE SURFACE...ANY SHOWERS AND THUNDERSTORMS WILL ENCOUNTER SUBSIDENCE EAST OF THE BLUE RIDGE. BEST PROBABILITY OF PRECIPITATION WILL BE IN THE NORTHWEST PART OF THE COUNTY WARNING AREA. NOT MUCH CHANGE IN AIR MASS FROM SUNDAY ABOVE THE BOUNDARY LAYER. 850 MB TEMPERATURES REMAIN ABOUT THE SAME BUT MUCH OF FORECAST AREA IS ON THE COOLER SIDE OF THE FRONT AND THERE WILL BE MORE CLOUD COVER IN THE NORTHERN COUNTY WARNING AREA TODAY SO MAXIMUM TEMPERATURES WILL BE CLOSER TO NORMAL. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... AS OF 330 AM EDT MONDAY... WEAK BOUNDARY REMAINS IN THE REGION THROUGH WEDNESDAY...BUT LIKE THE PAST FEW DAYS...THERE REMAINS NO TRIGGER FOR WIDESPREAD OR EVEN SCATTERED SHOWERS/THUNDERSTORMS. MODEL SOUNDINGS CONTINUE TO FORECAST DEWPOINTS/MOISTURE THAT DOES NOT FIT CURRENT OBSERVATIONS AND PWATS. KEPT ONLY SLT CHC POPS CONSIDERING THESE INCONSISTENCIES. WEAK SURFACE HIGH PRESSURE JUST SOUTH OF THE DELMARVA ON TUESDAY...SHOULD KEEP AN EASTERLY SURFACE BREEZE AND REINFORCE SLIGHTLY COOLER TEMPS...EXCEPT FOR EXTREME SW VA. THIS IS ONLY TEMPORARY AS A PESKY BOUNDARY MOVES BACK NORTH AS A WARM FRONT LATE WEDNESDAY. WAA WITH H85 TEMPS NEAR +18C COULD PUSH THE CITIES TO 90F THURSDAY. HOWEVER THE ECMWF IS DECIDEDLY COOLER...SO HOLDING OFF FOLLOWING THE HOT MEX MOS UNTIL THE MAX T SPREAD BETWEEN THE ECMWF AND GFS LESSENS. ATTM...WOULD LEAN TOWARDS THE WARMER VALUES OF THE MEX AT THE END OF THE SHORT TERM PERIOD. && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 350 PM EDT SATURDAY... NOTABLE DIFFERENCES EXHIBITED AMONG THE GFS AND ECMWF. THE GFS SHIFTS THE CENTRAL U.S. UPPER TROUGH INTO THE REGION FRI...BUT HOLDS A BROAD UPPER TROUGH AND CONSIDERABLE ENERGY BACK TO THE WEST...WHICH QUICKLY EVOLVES INTO ANOTHER DEEP UPPER TROUGH AFFECTING THE REGION BY SUN-MON. THE ECMWF SHEARS OUT THE FIRST TROUGH THROUGH THE OH VALLEY/NE U.S...THEN BRINGS THE MAIN TROUGH INTO THE REGION LATE IN THE WEEKEND/EARLY NEXT WEEK. CONSEQUENTLY...THE MODELS PRESENT COMPLETELY DIFFERENT SOLUTIONS WITH RESPECT TO TIMING OF SHRA/TSRA. HAVE CONTINUED WITH HIGH CHC- LOW LIKELY POPS FOR THE WESTERN AREAS SAT...THEN BROAD BRUSHED CHC POPS FOR SUN-MON UNTIL A CLEARER SOLUTION AND BETTER CONSISTENCY IS OBTAINED AMONG THE MODELS. THERE IS CLEARLY THE POTENTIAL FOR BONAFIDE WIDESPREAD RAINFALL SOMEWHERE IN THE FRI- MON TIME FRAME. CLOUD COVER AND INCREASED RAIN CHANCES WILL RESULT IN LOWER TEMPERATURES FRI INTO THE WEEKEND...ALTHOUGH THE PIEDMONT COULD REMAIN IN THE 80S YET FRIDAY. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... AS OF 730 AM EDT MONDAY... STATIONARY FRONT EXTENDED FROM MISSOURI TO NORTH CAROLINA THIS MORNING. LITTLE MOVEMENT OF THIS BOUNDARY IS EXPECTED THROUGH THE 06Z END OF THE TAF PERIOD. LOW CONFIDENCE ON THE DIRECTION OF THE WIND TODAY AND TONIGHT. WINDS MAY SHIFT DIRECTION PERIODICALLY AS THE FRONT WAVERS BACK AND FORTH ACROSS THE REGION. UNSTABLE AIR WILL DEVELOP SOUTH OF THE FRONT BY THIS AFTERNOON. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL LINE UP ALONG THE FRONT FROM ILLINOIS INTO VIRGINIA. BUFKIT SOUNDINGS SHOWED A CAP AT KDAN AND KLYH WHICH MAY SUPPRESS THE GROWTH OF SHOWERS AND THUNDERSTORMS TODAY BUT HAVE KEPT A BETTER CHANCE IN THE KBCB/KLWB/KBLF AND KROA TAFS THIS AFTERNOON. MVFR CEILINGS AND VISIBILITIES ARE LIKELY WITH THE THUNDERSTORMS. COVERAGE OF SHOWERS AND THUNDERSTORMS WILL DIMINISH AROUND SUNSET. TUESDAY INTO WEDNESDAY...THE FRONT WILL REMAIN STALLED OVER THE FORECAST AREA RESULTING IN A PERSISTENT CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON AND EVENING. MVFR CONDITIONED SHOULD BE EXPECTED WITH ANY OF THE SHOWERS AND STORMS. THURSDAY THE FRONT LIFTS NORTH WITH DRIER WEATHER AND WARMER AIR MOVING INTO THE REGION. BY LATE FRIDAY A COLD FRONT WILL APPROACH FROM THE WEST...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...KM LONG TERM...RAB AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
732 AM EDT MON MAY 5 2014 .SYNOPSIS... A WEAK FRONT TRAILED FROM MISSOURI TO SOUTHWEST VIRGINIA AND INTO NORTHERN NORTH CAROLINA. LITTLE CHANGE IN THIS WEATHER PATTERN IS EXPECTED THROUGH WEDNESDAY. AN UPPER RIDGE WILL BUILD OVER THE REGION THURSDAY...RESULTING IN WARMER...DRIER CONDITIONS. HIGH PRESSURE WILL GIVE WAY TO A SLOW MOVING FRONTAL SYSTEM LATE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EDT MONDAY... LINE OF SHOWERS WAS PARALLEL TO AND NORTH OF A STATIONARY FRONT. THE SHOWERS WERE LINED UP FROM NORTH OF INDIANAPOLIS TO SOUTH OF COLUMBUS TO NORTH OF CHARLESTON WV. THE ACTUAL FRONT EXTENDED FROM NEAR ST. LOUIS TO SOUTHERN VIRGINIA. LITTLE CHANGE IS EXPECTED IN THE POSITION AND ORIENTATION OF THE FRONT AND BAROCLINIC ZONE TODAY AND TONIGHT SINCE THEY WILL BE PARALLEL TO THE UPPER FLOW THROUGH THIS TIME FRAME. RAP AND NAM GUIDANCE HAVE REASONABLE PLACEMENT OF AXIS OF PRECIPITATION THROUGH TONIGHT. EAST END OF THE FRONT WILL PUSH FARTHER SOUTH IN TO NORTH CAROLINA THIS MORNING WITH A POCKET OF COOLER AND MORE STABLE AIR JUST BEHIND IT. THIS WAS REFLECTED IN THE BUFKIT SOUNDINGS WHICH SHOWED A MID LEVEL CAP AT DANVILLE AND LYNCHBURG TODAY WITH MORE SURFACE BASED INSTABILITY AND CAPE IN THE MOUNTAINS. WITH THE DEEP NORTHWEST FLOW ASIDE FROM NEAR THE SURFACE...ANY SHOWERS AND THUNDERSTORMS WILL ENCOUNTER SUBSIDENCE EAST OF THE BLUE RIDGE. BEST PROBABILITY OF PRECIPITATION WILL BE IN THE NORTHWEST PART OF THE COUNTY WARNING AREA. NOT MUCH CHANGE IN AIR MASS FROM SUNDAY ABOVE THE BOUNDARY LAYER. 850 MB TEMPERATURES REMAIN ABOUT THE SAME BUT MUCH OF FORECAST AREA IS ON THE COOLER SIDE OF THE FRONT AND THERE WILL BE MORE CLOUD COVER IN THE NORTHERN COUNTY WARNING AREA TODAY SO MAXIMUM TEMPERATURES WILL BE CLOSER TO NORMAL. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... AS OF 330 AM EDT MONDAY... WEAK BOUNDARY REMAINS IN THE REGION THROUGH WEDNESDAY...BUT LIKE THE PAST FEW DAYS...THERE REMAINS NO TRIGGER FOR WIDESPREAD OR EVEN SCATTERED SHOWERS/THUNDERSTORMS. MODEL SOUNDINGS CONTINUE TO FORECAST DEWPOINTS/MOISTURE THAT DOES NOT FIT CURRENT OBSERVATIONS AND PWATS. KEPT ONLY SLT CHC POPS CONSIDERING THESE INCONSISTENCIES. WEAK SURFACE HIGH PRESSURE JUST SOUTH OF THE DELMARVA ON TUESDAY...SHOULD KEEP AN EASTERLY SURFACE BREEZE AND REINFORCE SLIGHTLY COOLER TEMPS...EXCEPT FOR EXTREME SW VA. THIS IS ONLY TEMPORARY AS A PESKY BOUNDARY MOVES BACK NORTH AS A WARM FRONT LATE WEDNESDAY. WAA WITH H85 TEMPS NEAR +18C COULD PUSH THE CITIES TO 90F THURSDAY. HOWEVER THE ECMWF IS DECIDEDLY COOLER...SO HOLDING OFF FOLLOWING THE HOT MEX MOS UNTIL THE MAX T SPREAD BETWEEN THE ECMWF AND GFS LESSENS. ATTM...WOULD LEAN TOWARDS THE WARMER VALUES OF THE MEX AT THE END OF THE SHORT TERM PERIOD. && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 350 PM EDT SATURDAY... NOTABLE DIFFERENCES EXHIBITED AMONG THE GFS AND ECMWF. THE GFS SHIFTS THE CENTRAL U.S. UPPER TROUGH INTO THE REGION FRI...BUT HOLDS A BROAD UPPER TROUGH AND CONSIDERABLE ENERGY BACK TO THE WEST...WHICH QUICKLY EVOLVES INTO ANOTHER DEEP UPPER TROUGH AFFECTING THE REGION BY SUN-MON. THE ECMWF SHEARS OUT THE FIRST TROUGH THROUGH THE OH VALLEY/NE U.S...THEN BRINGS THE MAIN TROUGH INTO THE REGION LATE IN THE WEEKEND/EARLY NEXT WEEK. CONSEQUENTLY...THE MODELS PRESENT COMPLETELY DIFFERENT SOLUTIONS WITH RESPECT TO TIMING OF SHRA/TSRA. HAVE CONTINUED WITH HIGH CHC- LOW LIKELY POPS FOR THE WESTERN AREAS SAT...THEN BROAD BRUSHED CHC POPS FOR SUN-MON UNTIL A CLEARER SOLUTION AND BETTER CONSISTENCY IS OBTAINED AMONG THE MODELS. THERE IS CLEARLY THE POTENTIAL FOR BONAFIDE WIDESPREAD RAINFALL SOMEWHERE IN THE FRI- MON TIME FRAME. CLOUD COVER AND INCREASED RAIN CHANCES WILL RESULT IN LOWER TEMPERATURES FRI INTO THE WEEKEND...ALTHOUGH THE PIEDMONT COULD REMAIN IN THE 80S YET FRIDAY. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AS OF 730 AM EDT MONDAY... STATIONARY FRONT EXTENDED FROM MISSOURI TO NORTH CAROLINA THIS MORNING. LITTLE MOVEMENT OF THIS BOUNDARY IS EXPECTED THROUGH THE 06Z END OF THE TAF PERIOD. LOW CONFIDENCE ON THE DIRECTION OF THE WIND TODAY AND TONIGHT. WINDS MAY SHIFT DIRECTION PERIODICALLY AS THE FRONT WAVERS BACK AND FORTH ACROSS THE REGION. UNSTABLE AIR WILL DEVELOP SOUTH OF THE FRONT BY THIS AFTERNOON. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL LINE UP ALONG THE FRONT FROM ILLINOIS INTO VIRGINIA. BUFKIT SOUNDINGS SHOWED A CAP AT KDAN AND KLYH WHICH MAY SUPPRESS THE GROWTH OF SHOWERS AND THUNDERSTORMS TODAY BUT HAVE KEPT A BETTER CHANCE IN THE KBCB/KLWB/KBLF AND KROA TAFS THIS AFTERNOON. MVFR CEILINGS AND VISIBILITIES ARE LIKELY WITH THE THUNDERSTORMS. COVERAGE OF SHOWERS AND THUNDERSTORMS WILL DIMINISH AROUND SUNSET. TUESDAY INTO WEDNESDAY...THE FRONT WILL REMAIN STALLED OVER THE FORECAST AREA RESULTING IN A PERSISTENT CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON AND EVENING. MVFR CONDITIONED SHOULD BE EXPECTED WITH ANY OF THE SHOWERS AND STORMS. THURSDAY THE FRONT LIFTS NORTH WITH DRIER WEATHER AND WARMER AIR MOVING INTO THE REGION. BY LATE FRIDAY A COLD FRONT WILL APPROACH FROM THE WEST...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...KM LONG TERM...RAB AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
442 AM EDT MON MAY 5 2014 .SYNOPSIS... A WEAK FRONT TRAILED FROM MISSOURI TO SOUTHWEST VIRGINIA AND INTO NORTHERN NORTH CAROLINA. LITTLE CHANGE IN THIS WEATHER PATTERN IS EXPECTED THROUGH WEDNESDAY. AN UPPER RIDGE WILL BUILD OVER THE REGION THURSDAY...RESULTING IN WARMER...DRIER CONDITIONS. HIGH PRESSURE WILL GIVE WAY TO A SLOW MOVING FRONTAL SYSTEM LATE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EDT MONDAY... LINE OF SHOWERS WAS PARALLEL TO AND NORTH OF A STATIONARY FRONT. THE SHOWERS WERE LINED UP FROM NORTH OF INDIANAPOLIS TO SOUTH OF COLUMBUS TO NORTH OF CHARLESTON WV. THE ACTUAL FRONT EXTENDED FROM NEAR ST. LOUIS TO SOUTHERN VIRGINIA. LITTLE CHANGE IS EXPECTED IN THE POSITION AND ORIENTATION OF THE FRONT AND BAROCLINIC ZONE TODAY AND TONIGHT SINCE THEY WILL BE PARALLEL TO THE UPPER FLOW THROUGH THIS TIME FRAME. RAP AND NAM GUIDANCE HAVE REASONABLE PLACEMENT OF AXIS OF PRECIPITATION THROUGH TONIGHT. EAST END OF THE FRONT WILL PUSH FARTHER SOUTH IN TO NORTH CAROLINA THIS MORNING WITH A POCKET OF COOLER AND MORE STABLE AIR JUST BEHIND IT. THIS WAS REFLECTED IN THE BUFKIT SOUNDINGS WHICH SHOWED A MID LEVEL CAP AT DANVILLE AND LYNCHBURG TODAY WITH MORE SURFACE BASED INSTABILITY AND CAPE IN THE MOUNTAINS. WITH THE DEEP NORTHWEST FLOW ASIDE FROM NEAR THE SURFACE...ANY SHOWERS AND THUNDERSTORMS WILL ENCOUNTER SUBSIDENCE EAST OF THE BLUE RIDGE. BEST PROBABILITY OF PRECIPITATION WILL BE IN THE NORTHWEST PART OF THE COUNTY WARNING AREA. NOT MUCH CHANGE IN AIR MASS FROM SUNDAY ABOVE THE BOUNDARY LAYER. 850 MB TEMPERATURES REMAIN ABOUT THE SAME BUT MUCH OF FORECAST AREA IS ON THE COOLER SIDE OF THE FRONT AND THERE WILL BE MORE CLOUD COVER IN THE NORTHERN COUNTY WARNING AREA TODAY SO MAXIMUM TEMPERATURES WILL BE CLOSER TO NORMAL. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... AS OF 330 AM EDT MONDAY... WEAK BOUNDARY REMAINS IN THE REGION THROUGH WEDNESDAY...BUT LIKE THE PAST FEW DAYS...THERE REMAINS NO TRIGGER FOR WIDESPREAD OR EVEN SCATTERED SHOWERS/THUNDERSTORMS. MODEL SOUNDINGS CONITNUE TO FORECAST DEWPOINTS/MOISTURE THAT DOES NOT FIT CURRENT OBSERVATIONS AND PWATS. KEPT ONLY SLT CHC POPS CONSIDERING THESE INCONSISTENCIES. WEAK SURFACE HIGH PRESSURE JUST SOUTH OF THE DELMARVA ON TUESDAY...SHOULD KEEP AN EASTERLY SURFACE BRREZE AND REINFORCE SLIGHTLY COOLER TEMPS...EXCEPT FOR EXTREME SW VA. THIS IS ONLY TEMPORARY AS A PESKY BOUNDARY MOVES BACK NORTH AS A WARM FRONT LATE WEDNESDAY. WAA WITH H85 TEMPS NEAR +18C COULD PUSH THE CITIES TO 90F THURSDAY. HOWEVER THE ECMWF IS DECIDEDLY COOLER...SO HOLDING OFF FOLLOWING THE HOT MEX MOS UNTIL THE MAX T SPREAD BETWEEN THE ECMWF AND GFS LESSENS. ATTM...WOULD LEAN TOWARDS THE WARMER VALUES OF THE MEX AT THE END OF THE SHORT TERM PERIOD. && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 350 PM EDT SATURDAY... NOTABLE DIFFERENCES EXHIBITED AMONG THE GFS AND ECMWF. THE GFS SHIFTS THE CENTRAL U.S. UPPER TROUGH INTO THE REGION FRI...BUT HOLDS A BROAD UPPER TROUGH AND CONSIDERABLE ENERGY BACK TO THE WEST...WHICH QUICKLY EVOLVES INTO ANOTHER DEEP UPPER TROUGH AFFECTING THE REGION BY SUN-MON. THE ECMWF SHEARS OUT THE FIRST TROUGH THROUGH THE OH VALLEY/NE U.S...THEN BRINGS THE MAIN TROUGH INTO THE REGION LATE IN THE WEEKEND/EARLY NEXT WEEK. CONSEQUENTLY...THE MODELS PRESENT COMPLETELY DIFFERENT SOLUTIONS WITH RESPECT TO TIMING OF SHRA/TSRA. HAVE CONTINUED WITH HIGH CHC- LOW LIKELY POPS FOR THE WESTERN AREAS SAT...THEN BROAD BRUSHED CHC POPS FOR SUN-MON UNTIL A CLEARER SOLUTION AND BETTER CONSISTENCY IS OBTAINED AMONG THE MODELS. THERE IS CLEARLY THE POTENTIAL FOR BONAFIDE WIDESPREAD RAINFALL SOMEWHERE IN THE FRI- MON TIME FRAME. CLOUD COVER AND INCREASED RAIN CHANCES WILL RESULT IN LOWER TEMPERATURES FRI INTO THE WEEKEND...ALTHOUGH THE PIEDMONT COULD REMAIN IN THE 80S YET FRIDAY. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... AS OF 140 AM EDT MONDAY... STATIONARY FRONT EXTENDED ACROSS KENTUCKY AND VIRGINIA EARLY THIS MORNING. LITTLE MOVEMENT OF THIS BOUNDARY IS EXPECTED THROUGH THE 06Z END OF THE TAF PERIOD. LOW CONFIDENCE ON THE DIRECTION OF THE WIND TODAY AND TONIGHT. WINDS WERE LIGHT AND VARIABLE AT 05Z/1AM AND MAY SHIFT DIRECTION PERIODICALLY AS THE FRONT WAVERS BACK AND FORTH ACROSS THE REGION. UNSTABLE AIR WILL DEVELOP SOUTH OF THE FRONT BY THIS AFTERNOON. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL LINE UP ALONG THE FRONT FROM ILLINOIS INTO VIRGINIA. BUFKIT SOUNDINGS SHOWED A CAP AT KDAN AND KLYH WHICH WILL SUPPRESS THE GROWTH OF SHOWERS AND THUNDERSTORMS TODAY BUT HAVE KEPT A LOW CHANCE IN THE KBCB/KLWB/KBLF AND KROA TAFS THIS AFTERNOON. MVFR CEILINGS AND VISIBILITIES ARE LIKELY WITH THE THUNDERSTORMS. COVERAGE OF SHOWERS AND THUNDERSTORMS WILL DIMINISH AROUND SUNSET. TONIGHT INTO WEDNESDAY...THE FRONT WILL REMAIN STALLED OVER THE FORECAST AREA. IMPULSES ALONG THIS BOUNDARY WILL BRING AN INCREASING CHANCE FOR SUB-VFR CEILINGS AND PERIODS OF SHRA/TSRA. THURSDAY THE FRONT LIFTS NORTH WITH DRIER WEATHER AND WARMER AIR MOVING INTO THE REGION. BY LATE FRIDAY A COLD FRONT WILL APPROACH FROM THE WEST...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...KM LONG TERM...RAB AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
945 PM CDT TUE MAY 6 2014 .UPDATE... LATEST HRRR MESOSCALE MODEL HAS THE NARROW BAND OF SHOWERS AND THUNDERSTORMS AND MOVES THEM OFF TO THE EAST. THEN NOT MUCH UNTIL 3 AM CDT WHEN THERE IS A RAPID INCREASE IN COVERAGE THAT CONTINUES THROUGH THE REST OF THE NIGHT. UPPER DIVERGENCE INCREASES AT THIS TIME ALONG WITH UPWARD MOTION. NAM HAS 500 JOULES/KG OF ELEVATED CAPE LIFTED FROM 5 THSD FT LATER TONIGHT. GIVEN THE BRIEF SMALL HAIL PRODUCERS...EXPECT HAIL POTENTIAL WITH THE LATER DEVELOPING STORMS AS WELL. && .AVIATION/06Z TAFS/... LATEST HRRR MESOSCALE MODEL HAS THE NARROW BAND OF SHOWERS AND THUNDERSTORMS AND MOVES THEM OFF TO THE EAST. THEN NOT MUCH UNTIL 3 AM CDT WHEN THERE IS A RAPID INCREASE IN COVERAGE THAT CONTINUES THROUGH THE REST OF THE NIGHT. UPPER DIVERGENCE INCREASES AT THIS TIME ALONG WITH UPWARD MOTION. NAM HAS 500 JOULES/KG OF ELEVATED CAPE LIFTED FROM 5 THSD FT LATER TONIGHT. GIVEN THE BRIEF SMALL HAIL PRODUCERS...EXPECT HAIL POTENTIAL WITH THE LATER DEVELOPING STORMS AS WELL. VFR CONDITIONS BECOMING MVFR TOWARDS SUNRISE AS THE PRECIPITATION INCREASES. THE SHOWERS AND STORMS SHOULD GRADUALLY SHIFT NORTHEASTWARD WEDNESDAY MORNING...LOW CLOUDS WITH MVFR CEILINGS SHOULD GRADUALLY BECOME SCATTERED TO BROKEN IN THE AFTERNOON...WITH MAINLY VFR CEILINGS. && .PREV DISCUSSION... /ISSUED 341 PM CDT TUE MAY 6 2014/ TONIGHT AND WEDNESDAY..FORECAST CONFIDENCE IS HIGH. SHORT TERM MODELS STILL IN PRETTY GOOD AGREEMENT WITH FOCUSED 850MB WARM AIR ADVECTION OCCURRING ACROSS THE AREA LATER TONIGHT...AIDED BY AN INCREASING 850MB LOW LEVEL JET. THIS SHOULD COMBINE WITH SOME 700 MB TO 500 MB FRONTOGENESIS AND MOISTURE ADVECTION ABOVE THE INVERSION TO BRING A ROUND OF SHOWERS AND THUNDERSTORMS LATER TONIGHT. A 500 MB VORTICITY MAXIMUM MOVING NORTHEAST FROM THE SOUTH CENTRAL PLAINS MAY ALSO HELP AID PRECIPITATION. BEST POPS WILL BE ACROSS THE NORTHERN PORTIONS OF THE AREA...WHERE BEST UPWARD VERTICAL MOTION IS EXPECTED. ELEVATED CAPES OF 500 TO 800 J/KG WITH DECENT EFFECTIVE LAYER SHEAR SUGGESTS SMALL HAIL IS POSSIBLE WITH ANY STORMS. GUSTY EAST WINDS WILL LINGER...WITH MID 40S LAKESIDE TO AROUND 50 WELL INLAND. MAIN ISSUE WILL BE STRONG CAP THAT IS EXPECTED TO DEVELOP LATER TONIGHT AND REMAIN ON WEDNESDAY ACROSS THE AREA. THE WARM AIR ADVECTION HELPS BUILD THIS CAP...WHICH IS EXPECTED TO BE QUITE STRONG...OVER 100 J/KG BY WEDNESDAY AFTERNOON. THUS...IT WILL TAKE VERY STRONG UPWARD VERTICAL MOTION TO BREAK THIS CAP. SO...GRADUALLY BROUGHT POPS DOWNWARD IN THE MORNING FROM SOUTH TO NORTH. WENT WITH A DRY FORECAST SOUTH IN THE AFTERNOON AND LOW POPS IN THE NORTH. THE AFTERNOON MAY BE DRY ACROSS THE ENTIRE AREA. LOW CLOUDS IN THE MORNING WITH PRECIPITATION SHOULD BECOME MORE SCATTERED TO BROKEN DURING THE AFTERNOON. EASTERLY WINDS WILL LINGER...AND WILL KEEP LAKESHORE AREAS IN THE 50S. 60S ARE EXPECTED NORTH OF MADISON...WITH 70S TO THE SOUTH OF THERE. MAY CRACK 80 IN THE FAR SOUTHWEST COUNTIES. WEDNESDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM. THE SURFACE WARM FRONT WILL MAKE A MOVE NORTH THROUGH THE FORECAST AREA OVERNIGHT...WHILE THE 850MB WARM FRONT WILL BLAST WELL NORTH OF OUR CWA DURING THE EVENING. IF THIS PANS OUT...THE CHANCE FOR THUNDERSTORMS WILL BE MAINLY LIMITED TO NORTH OF MILWAUKEE AND MADISON. ACTUALLY...GIVEN THIS SCENARIO IT LOOKS LIKE THE ENTIRE FORECAST AREA WILL STAY DRY WEDNESDAY NIGHT WITH THE FOCUS WELL NORTH IN THE BETTER BAROCLINIC ZONE. IN ADDITION...A WEAK SHORT WAVE WILL BE EXITING TO THE NORTH WITH SHORT WAVE RIDING MOST LIKELY FOR THE AREA THIS PERIOD. THE SOUNDINGS SHOW THE H8 WARM SECTOR PROVIDING A SERIOUS CAP TO CONVECTION WITH THE ATMOSPHERE LOOKING VERY DRY ABOVE 4KFT AS WELL. MAIN MESSAGE...LOTS OF NEGATIVES TO ANY PRECIP DEVELOPMENT...BUT CAN/T RULE IT OUT COMPLETELY. IT/S ALL ABOUT THE WARM FRONT... THURSDAY AND THURSDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM. WE/LL BE SOLIDLY IN THE WARM SECTOR ON THURSDAY WITH DEW POINTS CLIMBING TO AROUND 60. MUCH OF THE GUIDANCE SUGGESTS THE EAST WILL STAY DRY INTO THE AFTERNOON AND COMBINED WITH A LITTLE SUNSHINE WE SHOULD SEE MANY AREAS HIT THE 80 DEGREE MARK. THE FOCUS WILL BE ON A STRONG SURFACE THAT LOW WILL TRACK INTO SOUTHERN MN BY EARLY THU EVENING WITH THE TRAILING COLD FRONT STILL OUT ACROSS WESTERN IOWA. THE LOW LEVEL CAP DOES ERODE BY AFTERNOON AND WITH THE UPPER TROF APPROACHING THERE WILL BE A SERIES OF SHORT WAVES ROLLING NORTH INTO THE REGION. THE AGGREGATE SEVERE WEATHER PARAMETER FROM THE NAM CLIMBS TO THE LOWER 80S WEST OF MADISON DURING THE AFTERNOON WITH THE GFS JUST A BIT LOWER. THE CIPS ANALOGS SHOW AN ACTIVE HISTORICAL COMPARISON TO THIS PATTERN. SO...THURSDAY IS LOOKING VERY WARM WITH THE CHANCE FOR STORMS MAINLY WEST OF MADISON THROUGH THE DAY. GIVEN THE CAPE AND SHEAR PROFILES...SEVERE STORMS POSSIBLE AND WE ARE OUTLOOKED BY SPC. THE COLD FRONT WILL ENTER THE CWA LATER THURSDAY NIGHT SO POPS WILL INCREASE OVERNIGHT. IT/S TOO EARLY TO TELL HOW STRONG THESE STORMS MAY BE OVERNIGHT ESPECIALLY WITH THE PARENT LOW MOVING UP INTO WESTERN LAKE SUPERIOR. TRENDS WILL CERTAINLY FADE AS THE EVENING PROGRESSES. FRIDAY...FORECAST CONFIDENCE IS MEDIUM. THE FRONT WILL EXIT TO THE EAST EARLY IN THE MORNING WITH THE PRECIP COMING TO AN END AS COOLER AND DRIER AIR ADVECTS IN. WE SHOULD STILL GET INTO THE 60S HOWEVER. FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE IS HIGH. HIGH PRESSURE WILL BRING US A DRY PERIOD HERE. TEMPS ON SATURDAY WILL CLIMB INTO THE MID AND UPPER 60S WITH SOME SUNSHINE. SATURDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE IS LOW. THE ECMWF AND THE GFS ARE HANDLING THE EVOLUTION OF LOW PRESSURE MOVING THROUGH THE GREAT LAKES VERY DIFFERENTLY. THE EC IS MUCH SLOWER WITH A SOUTHERN LOW PRESSURE SYSTEM THAT CREEPS NORTH SUNDAY THROUGH MONDAY. MEANWHILE...THE GFS DEVELOPS LOW PRESSURE TO OUR NORTH AND WEST AND MOVES IT THROUGH THE WESTERN GREAT LAKES. EITHER WAY...THIS WILL RESULT IN CHANCES OF SHOWERS AND THUNDERSTORMS. AVIATION/00Z TAFS/... VFR CONDITIONS ARE EXPECTED THROUGH THIS EVENING ACROSS TAF SITES. EAST TO NORTHEAST WINDS WITH GUSTS TO AROUND 20 KNOTS ARE EXPECTED INTO THE EARLY EVENING...BECOMING EAST BY MID TO LATE EVENING. THE MIDDLE TO HIGH CLOUDS WILL GRADUALLY MOVE EAST INTO THE AREA THIS EVENING. THE EAST WINDS WILL LINGER TONIGHT...BECOMING EAST TO SOUTHEAST ON WEDNESDAY. GUSTS TO AROUND 20 KNOTS ARE POSSIBLE WEDNESDAY AS WELL. SHOWERS AND THUNDERSTORMS SHOULD DEVELOP AROUND 07Z TO 09Z WEDNESDAY...AND LINGER UNTIL AROUND 12Z WEDNESDAY. MVFR VISIBILITIES ARE EXPECTED IN ANY STORMS...ALONG WITH SMALL HAIL. THE SHOWERS AND STORMS SHOULD GRADUALLY SHIFT NORTHEASTWARD WEDNESDAY MORNING...LEAVING THE TAF SITES DRY IN THE LATE MORNING AND IN THE AFTERNOON. LOW CLOUDS WITH MVFR CEILINGS SHOULD GRADUALLY BECOME SCATTERED TO BROKEN IN THE AFTERNOON...WITH VFR CEILINGS. MARINE... A TIGHT PRESSURE GRADIENT WILL CONTINUE TO DEVELOP TONIGHT INTO WEDNESDAY...AS LOW PRESSURE ORGANIZES IN THE CENTRAL PLAINS. THIS WILL RESULT IN A PERIOD OF INCREASING EAST TO NORTHEAST WINDS ACROSS THE NEARSHORE WATERS OF LAKE MICHIGAN INTO THE EVENING...BECOMING EAST TO SOUTHEAST ON WEDNESDAY. SOME GUSTS WILL REACH 25 KNOTS LATER TONIGHT INTO WEDNESDAY. RESULTANT WAVES SHOULD INCREASE INTO THE 3 TO 5 FOOT RANGE LATER TONIGHT...AND 3 TO 6 FEET ON WEDNESDAY. THUS...A SMALL CRAFT ADVISORY WAS ISSUED FROM 09Z WEDNESDAY TO 00Z THURSDAY. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 4 AM TO 7 PM CDT WEDNESDAY FOR LMZ643>646. && $$ UPDATE...HENTZ TONIGHT/WEDNESDAY AND AVIATION/MARINE...WOOD WEDNESDAY NIGHT THROUGH TUESDAY...DAVIS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
352 AM CDT MON MAY 5 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 350 AM CDT MON MAY 5 2014 WATER VAPOR IMAGERY SHOWS A SHORT WAVE TROUGH MOVING EAST THROUGH NORTHERN WISCONSIN AND SOUTHEAST MINNESOTA. WITH 290K ISENTROPIC CONDENSATION DEFICITS SOUTH OF WISCONSIN 29 RUNNING BETWEEN 100 TO 200 MB...NOT EXPECTING ANY RAIN SOUTH OF THIS STATE HIGHWAY. MEANWHILE ACROSS NORTHERN AND EASTERN TAYLOR COUNTY...290K ISENTROPIC CONDENSATION PRESSURE DEFICITS ARE LESS THAN 10 MB. DUE TO THIS...KEPT A 20 TO 30 PERCENT CHANCE OF RAIN THROUGH 05.15Z. IN THE WAKE OF THIS SYSTEM...ANOTHER SHORT WAVE TROUGH /CURRENTLY OVER NORTHWEST MINNESOTA/ WILL MOVE THROUGH NORTH CENTRAL WISCONSIN AROUND 05.18Z. WHILE THE 290K ISENTROPIC CONDENSATION PRESSURE DEFICITS ARE RUNNING 20 MB OR LESS...THE ONLY MESO MODEL WHICH GENERATES ANY PRECIPITATION IS THE NMM. SINCE THIS MODEL TENDS TO OVER DO ITS PRECIPITATION KEPT THE FORECAST DRY FOR NOW. WILL HAVE TO MONITOR RADAR TRENDS CLOSELY THIS MORNING TO MAKE THAT THE DRY FORECAST TREND WITH THIS SYSTEM CONTINUES. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 350 AM CDT MON MAY 5 2014 ON TUESDAY EVENING...THE GFS...NAM...AND ECMWF CONTINUE TO SUGGEST THAT A THUNDERSTORM COMPLEX WILL DEVELOP OVER EASTERN SOUTH DAKOTA...SOUTHWEST MINNESOTA...AND NORTHWEST IOWA. CORFIDI VECTORS THEN SUGGEST THAT THIS COMPLEX WILL MOVE EAST NORTHEAST ACROSS SOUTHEAST MINNESOTA...AND ALONG AND NORTH OF INTERSTATE 90 IN WESTERN WISCONSIN. BUFKIT SOUNDINGS SUGGEST THAT THIS SYSTEM WILL BE ELEVATED. STRONG 850 MB MOISTURE TRANSPORT WILL BE BRINGING MOST UNSTABLE CAPES OF 1500 TO 2500 J/KG INTO THE AREAS ALONG AND SOUTH OF THE INTERSTATE 90 CORRIDOR. IN ADDITION...THE 1-6 KN SHEAR IS IN THE EXCESS OF 40 KNOTS. THIS IS SUFFICIENT FOR A FEW ELEVATED SUPERCELLS. HOWEVER THE BUFKIT SOUNDINGS CONTINUE TO SHOW VERY SKINNY CAPE...SO THERE ARE QUESTIONS ON WHETHER YOU WILL BE ABLE TO GENERATE LARGE HAIL OR NOT. HOWEVER WITH A FREEZING LEVEL AROUND 13K FEET...COULD NOT RULE OUT A FEW STORMS PRODUCING QUARTER SIZE HAIL. ON WEDNESDAY...THE MODELS CONTINUE TO STRUGGLE ON WHERE THE WARM FRONT WILL BE LOCATED. THIS HAS A HUGE IMPACT ON HIGH TEMPERATURES FOR THIS DAY. THE UKMET HAS THE WARM FRONT NORTH OF THE FORECAST AREA. AS A RESULT...TEMPERATURES NORTH OF INTERSTATE 94 ARE IN THE 70S AND WELL INTO THE 80S ALONG AND SOUTH OF THIS INTERSTATE. THE GEM HAS THE WARM FRONT MOVING UP INTO THE INTERSTATE 94 CORRIDOR. IT HAS HIGH TEMPERATURES IN THE LOWER AND MID 80S SOUTH OF INTERSTATE 94...AND IN THE 50S AND 60S FOR CLARK AND TAYLOR COUNTIES. THE ECMWF HAS THE FRONT AS FAR NORTH AS INTERSTATE 90. IT HAS HIGH TEMPERATURES IN THE LOWER AND MID 80S ACROSS NORTHEAST IOWA AND SOUTHWEST WISCONSIN...NEAR 70 ALONG THE INTERSTATE 90 CORRIDOR...AND IN THE 50S AND 60S ALONG AND NORTH OF INTERSTATE 94. MEANWHILE THE GFS AND NAM HAS THE WARM FRONT LOCATED OVER NORTHEAST IOWA AND SOUTHWEST WISCONSIN. THIS RESULTS IN HIGH TEMPERATURES IN THE 70S ACROSS NORTHEAST IOWA AND SOUTHEAST MINNESOTA...AND IN THE 50S AND 60S ACROSS THE REMAINDER OF THE AREA. DUE TO THE WIDE VARIETY OF SOLUTIONS...OPTED TO GO WITH CONSENSUS. ON WEDNESDAY NIGHT...THERE CONTINUES TO BE QUITE A BIT OF UNCERTAINTY ON WHERE ANOTHER MESOSCALE CONVECTIVE COMPLEX WILL TRACK. THE U.S. MODELS SUGGEST THAT THIS SYSTEM WILL TRACK EAST ALONG INTERSTATE 90. MEANWHILE THE NON U.S. MODELS SUGGEST THAT THIS SYSTEM WILL DEVELOP MUCH FURTHER NORTH AND THE AREA MAY REMAIN DRY. SINCE THE NON U.S. MODELS SEEM TO MAKE A BIT MORE SENSE BASED ON THE POSITION OF THE SHORT WAVE TROUGH...OPTED TO TREND THE FORECAST MORE TOWARD THEM. ON THURSDAY...A WARM CONVEYOR BELT OF GULF MOISTURE MOVES NORTHWARD INTO THE AREA AHEAD OF THE SHORT WAVE OVER THE PLAINS. DEPENDING ON WHEN THIS ARRIVES...THERE MAY BE ENOUGH TIME TO BUILD ENOUGH CAPES FOR THE POSSIBILITY OF A FEW ISOLATED SEVERE STORMS TO DEVELOP. ONCE THIS BAND OF PRECIPITATION MOVES INTO THE AREA MUCH OF THIS CAPES IS USED TO GENERATE BANDS OF SHOWERS AND THUNDERSTORMS. WITH THE 0-6 KM SHEAR GENERALLY LESS THAN 30 KNOTS...NOT EXPECTING ANY SEVERE WEATHER AT THIS TIME. ON THURSDAY NIGHT...THE MODELS SHOW THAT A NEGATIVE TILTED SHORT WAVE TROUGH WILL MOVE NORTHEAST THROUGH THE AREA. WHILE THERE IS SUFFICIENT 0-3 KM AND 0-6 KM SHEAR OVER THE AREA FOR SUPERCELLS TO DEVELOP...THE SURFACE BASED...ML CAPES...AND MOST UNSTABLE CAPES REMAIN LESS THAN 250 J/KG. AS A RESULT...NOT IMPRESSED WITH THE SEVERE WEATHER CHANCES EAST OF INTERSTATE 35. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1143 PM CDT SUN MAY 4 2014 THE TAF SITES LOOK TO BE IN BETWEEN SYSTEMS FOR THE OVERNIGHT HOURS. SHORT WAVE TROUGH MOVING ACROSS NORTH DAKOTA WILL TRACK ACROSS MINNESOTA AND LAKE SUPERIOR THROUGH MONDAY MORNING. THE FRONTOGENESIS WITH THIS WAVE WILL SET UP ACROSS NORTHERN WISCONSIN WITH THE 05.00Z NAM AND HRRR KEEPING ANY OF THE LIGHT RAIN THAT DEVELOPS WELL TO THE NORTH. ANOTHER SHORT WAVE TROUGH MOVING ACROSS NEBRASKA WILL TRACK SOUTH OF THE TAF SITES ACROSS SOUTHERN IOWA INTO ILLINOIS. THERE SHOULD BE SOME WEAK MOISTURE TRANSPORT AHEAD OF THIS WAVE BUT THE HRRR KEEPS PUSHING THE AREA WHERE SOME SHOWERS MAY DEVELOP FARTHER EAST INTO ILLINOIS...WHICH IS WHERE THE NAM ALSO NOW SHOWS THIS OCCURRING. THIS SHOULD JUST LEAVE MID LEVEL CLOUDS AND VFR CEILINGS OVER THE TAF SITES TONIGHT. THESE CLOUDS SHOULD THEN SCATTER OUT MONDAY MORNING WITH ONLY HIGH CLOUDS FOR THE REMAINDER OF THE PERIOD. && .HYDROLOGY... ISSUED AT 355 AM CDT MON MAY 5 2014 FLOODING CONTINUES ALONG THE MAIN STEM OF THE MISSISSIPPI RIVER...WITH LOCATIONS CRESTING THIS WEEK. CHECK OUT THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS. THE NEXT ROUNDS OF SHOWERS AND THUNDERSTORMS FOR THE TUESDAY NIGHT THROUGH FRIDAY COULD HELP KEEP THE RIVER LEVEL ELEVATED...SLOWING THE RATE OF FALL AFTER CREST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...04 HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1143 PM CDT SUN MAY 4 2014 .SHORT TERM...(TONIGHT AND MONDAY) ISSUED AT 240 PM CDT SUN MAY 4 2014 A WEAK PERTURBATION ALONG THE UPPER LEVEL FLOW WILL SLIDE ACROSS THE NORTHERN PLAINS TONIGHT...MOVING OVER NORTHERN PARTS OF THE REGION OVERNIGHT/MON MORNING. THE LEFT ENTRANCE REGION OF AN UPPER LEVEL JET STREAK WILL ENHANCE THE LIFT FROM THE SHORTWAVE...AND WITH ENOUGH SATURATION PER RH FIELDS...AN AREA OF SHOWERS SHOULD DEVELOP. NAM/GFS/EC AND THE MESO MODELS ALL FAVOR A SWATH RUNNING FROM NORTHERN MN INTO NORTHERN WI...EXITING SOUTHEAST MON AFTERNOON. THE AIR IS RATHER DRY IN THE SUB CLOUD LAYER...BUT WITH BASES 5-6 KFT...RAIN SHOULD BE ABLE TO REACH THE SFC. MEANWHILE TO THE SOUTH...SOME HINTS IN THE MODELS THAT ANOTHER AREA OF PCPN COULD DEVELOP LATER TONIGHT. THIS WOULD BE NORTH OF A WARM FRONT HANGING OUT OVER THE MID MISSISSIPPI RIVER VALLEY. LOW LEVEL MOISTURE TRANSPORT INTO AND NORTH OF FRONT WOULD PUSH INTO SLOPING/ELEVATED FRONTOGENETIC LIFT...RESULTING IN A BAND OF SHOWERS OVER EASTERN IA/ILL. ENOUGH MODEL CONSENSUS TO ADD IN SMALL CHANCES FOR PARTS OF NORTHEAST IA/SOUTHWEST WI LATE TONIGHT/EARLY MONDAY. ALL IN ALL...DON/T EXPECT MUCH QPF OUT OF WHATEVER RAIN FALLS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 240 PM CDT SUN MAY 4 2014 LATE TUE THROUGH FRIDAY BRINGS A PERIOD OF WET CONDITIONS TO THE REGION AS A WEST COAST UPPER LEVEL TROUGH LIFTS INTO THE PLAINS...AND THEN ACROSS THE UPPER MISSISSIPPI RIVER VALLEY BY 12Z FRI. TUE NIGHT...A WEST-EAST RUNNING WARM FRONT WILL LAY UP ACROSS CENTRAL IA/NORTHERN ILL...WITH A PUSH OF 850 MB MOISTURE INTO AND NORTH OF IT. BITS OF UPPER LEVEL ENERGY ARE PROGGED TO SPIN OUT OF THE TROUGH STILL WELL WEST AT THIS TIME...AND MOVE ACROSS THE REGION...WHILE WEAK INSTABILITY POOLS AROUND THE SFC FRONT. EXPECT AN AREA OF SHOWERS AND THUNDERSTORMS TO DEVELOP IN RESPONSE TO THE FORCING...WITH THE LOW LEVEL JET/MOISTURE TRANSPORT HAVING A LARGE ROLE. MODELS SHIFT THE WARM FRONT NORTHWARD ON THU AS THE TROUGH AND ITS ASSOCIATED SFC LOW MOVE INTO THE PLAINS. SHOULD BE A WARM DAY...PERHAPS WARMEST DAY OF THE YOUNG SPRING SEASON...WITH EC 850 MB TEMP ANOMALIES OF 1 TO 2. HIGHS WILL TOP OUT IN THE 70S. THAT SAID...THE WARM TEMPS COULD BE TEMPERED BY PCPN. GFS BUFKIT SOUNDINGS POINT TO A STRONG CAP THANKS TO THE LOW LEVEL WARMING THU...INHIBITING ANY SFC BASED CONVECTION AHEAD OF THE APPROACHING LOW/COLD FRONT. HOWEVER...THE EC AND GFS CONTINUE TO PAINT QPF AHEAD OF THE FRONT AS PIECES OF UPPER LEVEL ENERGY SPIN ACROSS THE REGION. PLENTY OF INSTABILITY A LOFT FOR THE SHORTWAVES TO TAP INTO...WHICH COULD LEAD TO CONVECTION ABOVE THE CAP. IF STORMS GET GOING...AND COULD GET SFC BASED...0-3 AND 0-6 KM SHEAR ARE FAVORABLE FOR SEVERE STORM DEVELOPMENT. HOWEVER...IF THE STAY ABOVE THE CAP...1-6 KM SHEAR SITS AROUND 30 KTS. OKAY...BUT NOT GREAT FOR SEVERE POTENTIAL. THERE IS ABOUT 2000 J/KG OF MUCAPE TO WORK WITH. A LOT OF VARIABLES TO WATCH...BUT THU DOES POSE A SEVERE WEATHER AT THIS TIME. TO THE WEST...ALONG AND POST THE COLD FRONT...A STRONG LOW LEVEL JET...FRONTOGENETIC FORCING...AND THE UPPER LEVEL SHORTWAVE WILL WORK TOGETHER TO PRODUCE A BROAD AREA OF SHOWERS AND THUNDERSTORMS. CURRENT FORECAST TRACK OF THE STORM SYSTEM WOULD PLACE THE HEAVIEST RAIN ACROSS IA AND MN...JUST WEST OF THE LOCAL FORECAST AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1143 PM CDT SUN MAY 4 2014 THE TAF SITES LOOK TO BE IN BETWEEN SYSTEMS FOR THE OVERNIGHT HOURS. SHORT WAVE TROUGH MOVING ACROSS NORTH DAKOTA WILL TRACK ACROSS MINNESOTA AND LAKE SUPERIOR THROUGH MONDAY MORNING. THE FRONTOGENESIS WITH THIS WAVE WILL SET UP ACROSS NORTHERN WISCONSIN WITH THE 05.00Z NAM AND HRRR KEEPING ANY OF THE LIGHT RAIN THAT DEVELOPS WELL TO THE NORTH. ANOTHER SHORT WAVE TROUGH MOVING ACROSS NEBRASKA WILL TRACK SOUTH OF THE TAF SITES ACROSS SOUTHERN IOWA INTO ILLINOIS. THERE SHOULD BE SOME WEAK MOISTURE TRANSPORT AHEAD OF THIS WAVE BUT THE HRRR KEEPS PUSHING THE AREA WHERE SOME SHOWERS MAY DEVELOP FARTHER EAST INTO ILLINOIS...WHICH IS WHERE THE NAM ALSO NOW SHOWS THIS OCCURRING. THIS SHOULD JUST LEAVE MID LEVEL CLOUDS AND VFR CEILINGS OVER THE TAF SITES TONIGHT. THESE CLOUDS SHOULD THEN SCATTER OUT MONDAY MORNING WITH ONLY HIGH CLOUDS FOR THE REMAINDER OF THE PERIOD. && .HYDROLOGY... ISSUED AT 240 PM CDT SUN MAY 4 2014 FLOODING CONTINUES ALONG THE MAIN STEM OF THE MISSISSIPPI RIVER...WITH LOCATIONS CRESTING THIS WEEK. CHECK OUT THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS. THE NEXT ROUNDS OF SHOWERS AND THUNDERSTORMS FOR THE TUE NIGHT-FRI PERIOD COULD HELP KEEP THE RIVER LEVEL ELEVATED...SLOWING THE RATE OF FALL AFTER CREST. MODELS CURRENTLY FAVOR DROPPING THE HEAVIEST RAIN ACROSS THE HEADWATERS OF THE MISSISSIPPI THU/THU NIGHT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RIECK LONG TERM....RIECK AVIATION...04 HYDROLOGY....RIECK
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
545 PM MDT TUE MAY 6 2014 .SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY NIGHT) ISSUED AT 320 PM MDT TUE MAY 6 2014 HIGH CLOUD COVER LIMITED SFC HEATING OVER MUCH OF THE PLAINS THROUGH MIDDAY...HOWEVER MUCH BETTER CLEARING IS NOW SEEN OVER THE CWA. DEWPOINTS ACROSS THE PLAINS ARE LARGELY IN THE 40S SO THERE IS DECENT LLVL MOISTURE. WOULD BE MOST CONCERNED ABOUT STRONG TO MARGINALLY SEVERE STORMS IN CONVERSE COUNTY. THE RUC INDICATES AROUND 1000 J/KG OF SFC BASED CAPE THROUGH THE EARLY EVENING ALONG WITH GOOD DEEP LAYER SHEAR OF 50 KTS. THE HRRR MODELS HAS ALSO BEEN CONSISTENT AT SHOWING A DISCRETE CELL JUST TO THE NORTH OF CONVERSE COUNTY. NOT AS MUCH INSTABILITY (AROUND 500 J/KG OF CAPE) IS FCSTED OVER THE WESTERN NEBRASKA PANHANDLE...SO NOT AS CONCERNED ABOUT STRONG STORMS OUT THERE. ANY STORMS THAT DO DEVELOP SHOULD WEAKEN BY LATE EVENING. ONE MORE MILD NIGHT ACROSS THE CWA AHEAD OF THE UPPER TROUGH THAT IS LOCATED OVER UTAH. SFC LOW STRENGTHENS OVER NORTHEASTERN COLORADO BY LATE WED MORNING WITH NORTHEAST WINDS DEVELOPING ACROSS THE PLAINS. WEATHER CONCERN FROM LATE MORNING WED THROUGH THE AFTN WILL BE ON THE SEVERE THREAT OVER THE EXTREME SOUTHEASTERN PART OF THE CWA. SPC HAS A SLIGHT RISK OVER THE SOUTHERN HALF OF THE PANHANDLE. CAPE VALUES INCREASE TO AROUND 1000 J/KG BY 18Z ALONG INTERSTATE 80 IN THE SOUTHERN PANHANDLE. 0-3 KM HELICITY IS CLOSE TO 300 ALONG 0-6 KM SHEAR VALUES OF 55 KTS. THINKING THAT HAIL WILL BE THE PRIMARY THREAT...BUT CAN NOT RULE OUT A WEAK TORNADO WITH THE GOOD LLVL SHEAR. THE WINDOW FOR SVR WEATHER SHOULD NOT EXTEND MUCH LATER THAN THE EARLY AFTN HOWEVER...AS WINDS BECOME NORTHERLY BY LATE AFTN AND INSTABILITY IS ON THE DECREASE BEHIND THE FRONT. THE MODELS HAVE BEEN CONSISTENT WITH THE TRACK OF THE UPPER LEVEL SYSTEM. IT PUSHES INTO NORTHEASTERN COLORADO ON WED EVENING AND THEN BEGINS TO CLOSE OFF OVER SOUTHWESTERN NEBRASKA BY LATE WED NIGHT. A TROWAL IS SHOWN PUSHING INTO THE WESTERN NEBRASKA PANHANDLE BETWEEN 00-12Z THURS. EXCELLENT DEEP LAYER UPWARD MOTION IS DEPICTED LATE WED AFTN AND INTO THE EVENING OVER THE PLAINS OF SOUTHEAST WY...WHICH THEN SHIFTS INTO THE NEBRASKA PANHANDLE AFTER 06Z. THUS...STILL EXPECTING A WIDESPREAD HEAVY QPF EVENT FOR MUCH OF THE PLAINS. HPC HAS THE PANHANDLE IN A SLIGHT RISK FOR EXCEEDING FLASH FLOOD GUIDANCE. MUCH OF THE PRECIP WILL FALL AS RAIN OVER THE PLAINS...HOWEVER A TRANSITION TO SNOW COULD OCCUR AFTER AROUND 09Z FOR ELEVATIONS ABOVE 5000 FT OR SO. THE GFS HAS BEEN CONSISTENTLY THE WARMEST IN THE POST FRONTAL AIRMASS AS IT KEEPS SFC WET BULB TEMPS ABOVE 37F TO THE EAST OF THE LARAMIE RANGE THROUGH WED NIGHT...WHEREAS THE NAM IS CLOSE TO FREEZING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 320 PM MDT TUE MAY 6 2014 MEDIUM RANGE MODEL GUIDANCE IS IN EXCELLENT AGREEMENT WITH A POTENT UPPER-LEVEL SHORTWAVE AND ASSOCIATED SFC LOW EJECTING NORTHEAST INTO THE CENTRAL PLAINS EARLY IN THE PERIOD. BOTH THE GFS AND NAM SHOW A DISTINCT TROWAL FEATURE ON THE BACK SIDE OF THE LOW OVER THE WESTERN PANHANDLE. THIS COMBINED WITH GOOD QG ASCENT WILL MOST LIKELY YIELD A CONTINUATION OF MODERATE TO HEAVY PCPN FROM THE PANHANDLE INTO EAST CENTRAL WY BETWEEN 12-18Z THU. WITH 700-850 TEMPS BETWEEN 0 AND -5 C...WOULD EXPECT RAIN TO AT LEAST MIX WITH SNOW ESPECIALLY OVER THE HIGHER TERRAIN NEAR THE PINE RIDGE. NOT THINKING RATES WILL BE HIGH ENOUGH FOR SIGNIFICANT ACCUMULATIONS...BUT STILL CANNOT RULE OUT A FEW INCHES OF SNOW OVER OUR NORTHERN ZONES IN THE DEEPER COLD AIR. BEST FORCING AND MOISTURE SHIFTS NORTH AND EAST OF THE CWA BY EARLY AFTN...WITH PCPN CHANCES DIMINISHING THEREAFTER. QUASI-ZONAL FLOW ALOFT RETURNS TO THE AREA ON FRI AND SAT WITH A FEW NUISANCE DISTURBANCES EMBEDDED WITHIN. DESPITE SOME MODEST COOLING ALOFT FROM TIME TO TIME...WESTERLY DOWNSLOPE FLOW WILL GIVE WAY TO SEASONABLE TEMPS IN THE LOW TO MID 60S OVER THE PLAINS. COULD SEE A FEW SHOWERS OR RUMBLES OF THUNDER EACH AFTERNOON OVER MUCH OF THE AREA. GFS CAPES ARE GENERALLY LESS THAN 100 J/KG...BUT WITH STEEP MID LEVEL LAPSE RATES IN EXCESS OF 8.5 DEG C/KM...A STRAY LIGHTNING STRIKE CAN NEVER BE RULED OUT. BIG QUESTIONS COME INTO PLAY FOR THE SECOND HALF OF THE WEEKEND AND INTO EARLY NEXT WEEK. THE ECMWF REMAINS CONSISTENT WITH A CLOSED LOW AND TROUGH DIGGING INTO THE FOUR CORNERS WITH SFC CYCLOGENESIS OVER THE PLAINS OF EASTERN CO. LATEST GEM SHOWS A VERY SIMILAR FEATURE... SO THIS WILL BEAR WATCHING. 12Z GFS TELLS A DIFFERENT TALE...WITH A VERY PROGRESSIVE AND POSITIVELY TILTED OPEN WAVE MOVING QUICKLY ACROSS THE PLAINS. MADE VERY FEW CHANGES TO THE PREVIOUS FCST GIVEN THESE DIFFERENCES...BUT POTENTIAL EXISTS FOR ANOTHER MAJOR STORM LATE IN THE PERIOD IF THE ECMWF WERE TO VERIFY. SNOW WOULD AGAIN BE A GOOD POSSIBILITY AS H7 TEMPS PLUNGE AS LOW AS -10C. REGARDLESS OF WHICH MODEL IS CORRECT...COOLER AND BREEZY CONDITIONS SEEM TO BE A GOOD BET LATE IN THE WEEKEND. TRIMMED A FEW DEGREES OFF FCST HIGHS ON SUN AFTN AS WIDESPREAD CLOUD COVER AND COLD AIR ALOFT DO NOT LEND CREDENCE TO HIGHS NEAR 60F. && .AVIATION...(FOR THE 00Z TAFS THROUGH NOON WEDNESDAY) THE MAIN CONCERN WITH TAF ISSUANCE IS THE POTENTIAL FOR THUNDERSTORMS THIS EVENING ALONG WITH IFR/MVFR CEILINGS DEVELOPING OVER THE PANHANDLE OVERNIGHT. THUNDERSTORMS WILL GENERALLY BE ISOLATED IN NATURE UNTIL MIDNIGHT WITH ANOTHER CHANCE OF STRONG TO SEVERE TSTORMS ON WEDNESDAY EAST OF THE LARAMIE RANGE. OTHERWISE...LOW CIGS AND NEAR IFR CONDITIONS WILL BEGIN TO DEVELOP AROUND MIDNIGHT ACROSS THE NEBRASKA PANHANDLE DUE TO MOIST UPSLOPE FLOW...AND MAY PUSH INTO FAR SOUTHEAST WYOMING. PATCHY FOG IS ALSO POSSIBLE EARLY WEDNESDAY MORNING. && .FIRE WEATHER... ISSUED AT 320 PM MDT TUE MAY 6 2014 VERY DRY CONDITIONS EXIST TO THE WEST OF THE LARAMIE RANGE THIS AFTERNOON WITH RELATIVE HUMIDITY VALUES AT 10-15 PERCENT. SOUTHWEST WINDS ARE ALSO GUSTING TO 30 MPH. HOWEVER...FUELS ARE NOT SUPPORTIVE OF FIRE GROWTH WITH THE GREENUP IN PROGRESS. A STORM SYSTEM WILL MOVE ACROSS THE REGION ON WEDNESDAY AND WEDNESDAY NIGHT WITH AN EXCELLENT CHANCE OF WETTING PRECIPITATION...ESPECIALLY ALONG AND EAST OF THE LARAMIE RANGE. && .HYDROLOGY... ISSUED AT 320 PM MDT TUE MAY 6 2014 WARM TEMPERATURES THROUGH THIS AFTERNOON WILL RESULT IN EFFICIENT HIGH ELEVATION SNOW MELT. LATEST RIVER FORECASTS CONTINUE TO SURPASS FLOOD STAGE ON THE LITTLE SNAKE RIVER AT SAVERY BY LATE TONIGHT AND A FLOOD WARNING IS IN EFFECT. COOLER TEMPERATURES ON WEDNESDAY AND THURSDAY WILL SLOW SNOW MELT. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...FINCH LONG TERM...HAMMER AVIATION...TJT FIRE WEATHER...FINCH HYDROLOGY...FINCH
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
206 AM MST WED MAY 7 2014 .SYNOPSIS... PACIFIC LOW PRESSURE WILL CONTINUE TO MOVE THROUGH THE REGION TODAY...BRINGING COOLER TEMPERATURES AND ANOTHER ROUND OF AFTERNOON BREEZES. WINDS ARE NOT EXPECTED AS STRONG AS THOSE OBSERVED TUESDAY...WITH ONLY ISOLATED GUSTS POSSIBLE IN THE AFTERNOON. FORECAST DAYTIME HIGHS WILL FALL WELL BELOW NORMAL AT MANY DESERT LOCATIONS THROUGH THURSDAY. DRY AND WARMER WEATHER IS ON TAP FRIDAY AND THROUGH THE WEEKEND AS HIGH TEMPERATURES CLIMB BACK INTO THE 90S ACROSS THE LOWER DESERTS. && .DISCUSSION... SHARPLY DEFINED PACIFIC TROUGH CONTINUES TO SLOWLY CIRCULATE INTO THE REGION...WITH THE TROUGH AXIS NEARING THE COLORADO RIVER VALLEY THIS MORNING. NEARLY CLEAR SKIES LEFT OVER THE WHOLE CWA IN THE WAKE OF THE VIGOROUS COLD FRONT PASSAGE TUESDAY. SOME EARLY EVENING/OVERNIGHT LIGHT SHOWER ACTIVITY CONTINUES NEAR THE COLD CORE OF THE TROUGH OVER SOUTHERN NEVADA AND TO A LESSER EXTENT SOUTHEAST CALIFORNIA...WITH MOST SITES ONLY REPORTING OVERCAST SKIES AND A HUNDREDTH OR TWO OF PRECIP ACROSS THE SOUTHERN NEVADA STATIONS. WATER VAPOR LOOP AND POTENTIAL VORTICITY MODEL OVERLAY PLOT A POCKET OF ENHANCED VORTICITY/SPIN COMING AROUND THE TROUGH BOTTOM AND ACROSS THE CA/INTL BORDER THIS MORNING. THIS VORT LOBE IS PROGGED THROUGH CENTRAL ARIZONA BY MIDDAY BEFORE QUICKLY DIFFUSING AND CLEARING EAST THIS EVENING. MOISTURE TRANSPORT AND PWATS NOT OVERLY FAVORABLE FOR SIGNIFICANT SHOWER ACTIVITY...WITH THE BEST PWATS OF NEAR HALF AN INCH OVER THE COLORADO RIVER VALLEY BY MIDDAY AND NOT EXTENDING MUCH FURTHER EAST. EVENING RUNS OF THE HI-RES HRRR AND ARW SHOW ANY SHOWER ACTIVITY DEVELOPING ACROSS NORTHERN ARIZONA THROUGH THE DAY AS THE TROUGH CONTINUES THROUGH THE AREA...WITH ONLY VERY SPOTTY DEVELOPMENT SKIRTING ACROSS THE NORTHERN PORTIONS OF MARICOPA AND GILA COUNTIES THROUGH THE AFTERNOON. SLIGHT CHANCE POPS WERE KEPT ACROSS THE HIGHER TERRAIN TO THE NORTH/EAST OF PHOENIX...WITH MENTION DROPPING OFF AFTER 08/03Z (8PM LOCAL) ONCE HEATING SUPPORT IS LOST WITH SUNSET. SIGNIFICANT COOLING OBSERVED BEHIND THE COLD FRONT...AS MUCH AS 10 DEGREES FROM THE SFC UP THROUGH 400MB VIA THE KVEF 00Z RAOB AND 6-8 DEGREES FROM KFGZ...WILL KEEP TEMPERATURES TODAY AND THURSDAY WELL BELOW SEASONAL NORMALS. LOOK FOR MID TO UPPER 70S ACROSS THE SOUTH- CENTRAL ARIZONA DESERTS WITH SLIGHTLY WARMER VALUES ACROSS THE WESTERN FORECAST AREA IN THE LOW 80S WEDNESDAY AND WIDESPREAD 80S AREAWIDE FOR THURSDAY UNDER MOSTLY CLEAR SKIES. BY FRIDAY...TROUGHING WILL HAVE MOSTLY CLEARED THE AREA WITH DRY WEST TO NORTHWESTERLY FLOW OVERTAKING THE REGION. TEMPERATURES WILL REBOUND BACK TOWARDS EARLY MAY NORMALS WITH LOW TO MID 90 DEGREE READINGS IN STORE FOR THE WEEKEND. ANOTHER LOW PRESSURE SYSTEM WILL DROP OUT OF THE PACIFIC NORTHWEST LATE SATURDAY INTO SUNDAY...BUT CURRENT THINKING FROM WPC AND THE BETTER PERFORMING OPERATIONAL/ENSEMBLE RUNS OF THE ECMWF KEEP THE BULK OF THE ENERGY AND ANY PRECIPITATION WELL TO OUR NORTH THROUGH MUCH OF THE GREAT BASIN STATES AND ONLY SKIRTING THE FAR NORTHERN PORTIONS OF ARIZONA. COULD SEE SOME ENHANCED BREEZINESS AS SOME GRADIENT TIGHTENING IS FORECAST...BUT VERY STRONG WINDS ARE NOT EXPECTED AT THIS TIME. 500MB HEIGHTS AND THICKNESSES WILL SEE SOME DECREASE...WHICH WILL KEEP DAYTIME TEMPERATURES FROM TAKING OFF TOO RAPIDLY FOR EARLY NEXT WEEK AND STAYING CLOSER TOWARDS NORMAL READINGS IN THE LOW TO MID 90S. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... CIRRUS DECK WILL CONTINUE TO MOVE EAST...AS UPPER LEVEL LOW MOVES OVER THE REGION TONIGHT. MID LEVEL CLOUD DECKS MAY FORM OVERNIGHT WITH SCT CU AROUND 9000FT POSSIBLE OVER THE AREA. GUSTY WINDS WILL CONTINUE TO DECREASE OVERNIGHT...SETTLING IN AROUND 10KT...AND MAINTAINING A WEST-SOUTHWEST COMPONENT DURING THE TAF PERIOD. SUSPENDED DUST MAY ALSO CREATE SOME AREAS OF HAZE AND SLANT-WISE VISIBILITY ISSUES AT SOME AIRFIELDS WEDNESDAY MORNING. WINDS WILL INCREASE AGAIN WEDNESDAY AFTERNOON...WITH GUSTS UP TO 20 MPH COMMON AFTER 19Z. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... GUSTY SOUTHWEST TO WEST WINDS...UP TO 30 KTS...WILL PERSIST ACROSS SOUTHEAST CALIFORNIA THROUGH AT LEAST 06Z. WINDS TAPER OFF AT KBLH BUT WILL REMAIN ELEVATED AT KIPL UNTIL AROUND 12Z WEDNESDAY MORNING. OTHER THAN A FEW-SCT MID LEVEL CU AS UPPER LEVEL LOW MOVES OVER THE REGION TONIGHT...EXPECT MOSTLY CLEAR SKIES OVERNIGHT. WINDS WILL INCREASE AGAIN WEDNESDAY AFTERNOON...WITH GUSTS UP TO 25 MPH COMMON AFTER 19Z. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... THURSDAY THROUGH MONDAY... HIGH PRESSURE AND DRY NORTHWESTERLY FLOW ALOFT WILL BUILD EASTWARD INTO THE DESERT SOUTHWEST...AND BRING DRY CONDITIONS AND A SLOW WARMING TREND TO THE REGION THROUGH THE FORECAST PERIOD. HIGHS IN THE 80S ON THURSDAY WILL GRADUALLY WARM INTO THE MID TO UPPER 90S BY SUNDAY AND MONDAY. MINIMUM RH VALUES IN THE TEENS ON THURSDAY WILL LOWER BACK INTO THE SINGLE DIGITS OVER MUCH OF THE LOWER DESERTS BY THE WEEKEND. WINDS ARE EXPECTED TO REMAIN MOSTLY ON THE LIGHT SIDE EACH DAY...WITH JUST SOME TYPICAL AFTERNOON GUSTINESS. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...NOLTE AVIATION....MEYERS FIRE WEATHER...PERCHA/CB
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1246 AM CDT WED MAY 7 2014 .DISCUSSION... 909 PM CDT CONVECTION DEVELOPING ACROSS THE FAR NORTH METRO PROMPTED A SPECIAL WEATHER STATEMENT ISSUANCE. THE FORECAST WAS UPDATED TO REFLECT SLIGHTLY HIGHER CHANCES OF THUNDER NORTH OF INTERSTATE 80 THE REST OF TONIGHT...AS WELL AS TO MAKE SOME HOURLY FORECAST TEMPERATURE ADJUSTMENTS. THE SURFACE STATIONARY FRONT REMAINS DRAPED WELL TO OUR SOUTH THIS EVE WITH 00Z RAOBS AND CURRENT PROFILER ANALYSIS INDICATING A 40-45 KT SRLY LOW-LEVEL JET HAVING DEVELOPED NORTH OF THIS INTO IA AND ACROSS NORTHERN IL. THIN ARCS OF TCU WERE NOTED ON LATE DAY VISIBLE SATELLITE AND OBSERVATIONS HAVE INDICATED AN INCREASING LAYER OF 8K-10K FT CIGS. THE 00Z DVN RAOB AND AREA AMDAR SOUNDINGS WERE INDICATING A MOISTENING AROUND THAT 800-750MB LAYER...WHICH WHEN LIFTED FROM THAT LAYER ON THE DVN SOUNDING WOULD PROVIDE OVER 1500 J/KG OF MUCAPE...THOUGH WITH STILL A MINOR CAP. AS A SUBTLE SHORT WAVE NEAR KANSAS CITY PROGRESSES NORTHEAST AND OVERALL MOISTURE TRANSPORT STRENGTHENS...WOULD EXPECT TO SEE THAT SLIGHT CAPPING OVERCOME WITH ISOLATED TO SCATTERED CONVECTION DEVELOPING ACROSS THE EASTERN IA/SOUTHERN WI REGION...AND POSSIBLY NORTHERN IL...ESPECIALLY GIVEN CURRENT STORM WAS ALREADY ABLE TO DEVELOP. IN ADDITION...THE TREND WITH THE HOURLY-RAN HRRR HAS BEEN TO INCREASE COVERAGE OF SHOWERS/STORMS EARLY OVERNIGHT...WHICH GIVEN CURRENT OBSERVATIONAL ANALYSIS MAKES SENSE. HAVE BOOSTED POPS SOME OVER THE NORTHERN TWO TIERS OF COUNTIES BUT REMAIN IN THE CHANCE CATEGORY. GIVEN THE RADAR TRENDS WITH THE MCHENRY/LAKE COUNTY STORM...HAVING SPRUNG TO 40 DBZ OVER 35K FT WITHIN THREE SCANS OF DEVELOPING...COULD STILL SEE AN ELEVATED HAILER OR TWO ACROSS FAR NORTHERN ILLINOIS. THE ENVIRONMENT FOR THESE REMAINS MORE SUPPORTIVE TO THE WEST AND NORTHWEST OF THE LOCAL AREA. THE MARINE LAYER CONTINUED TO RE-INFORCE ITSELF EARLY THIS EVE ACROSS THE NORTH AND CENTRAL PARTS OF THE CHICAGO METRO...WITH SOME MID 40S ALONG THE LAKE SHORE AND LOWER 50S STARTING TO REACH SOME OUTLYING AREAS. DID ADJUST MINS DOWN BUT INDICATED SORT OF A LEVELING OFF TREND TO THIS TEMPERATURE FALL...WITH EVEN POTENTIAL RISING LATE GIVEN INCREASING SURFACE DEW POINTS. LOOKING AHEAD TO WEDNESDAY...STILL SOME POSSIBILITY TO SEE ISOLATED CONVECTION IN THE MORNING AS A WEAK SHORT WAVE PASSES...AND THE 00Z NAM CONTINUES TO SHOW THIS SUBTLE FEATURE. COULD ALSO BE SOME FOG DEVELOPING ACROSS FAR SOUTHERN LAKE MICHIGAN DURING THE MORNING AS THE WARM FRONT AND HIGH DEW POINTS BUTT UP AGAINST THE COOL LAKE. WITH THE WARM FRONT LIKELY TO PROGRESS SLOWER OVER THE MARINE LAYER...IT COULD INDUCE THE FOG. HAVE NOT ADDED INTO THE FORECAST AT THIS TIME BUT SOMETHING WE WILL WATCH AS THAT WOULD POSSIBLY MOVE INTO LAKE ADJACENT AREAS OF THE CHICAGO METRO. MTF //PREV DISCUSSION... 329 PM CDT SHORT TERM...TONIGHT THROUGH FRIDAY... PRIMARY FORECAST CONCERNS ARE WITH HOW WARM TEMPERATURES GET TOMORROW AND THURSDAY AND ON THUNDERSTORM POTENTIAL. W/V IMAGERY SHOWS THE ONGOING AMPLIFICATION OF UPPER RIDGING OVER THE MIDWEST INDUCED BY A DEEP TROUGH/CLOSED LOW OVER THE SOUTHWEST US. AT THE SURFACE...LOW PRESSURE IS DEVELOPING OVER THE SOUTHERN HIGH PLAINS WITH THE VERY STRONG WARM FRONT THAT HAS BEEN IN PLACE OVER THE REGION THE PAST FEW DAYS STRETCHING ACROSS DOWNSTATE IL AND IN. STRONG WAA ALOFT NORTH OF THE BOUNDARY HAS ALLOWED FOR TEMPERATURES TO WARM ABOVE 70 SOUTH OF I-80...WHILE ONSHORE FLOW HAS RESULTED IN ANOTHER COOL DAY FOR LAKESHORE AREAS. TONIGHT... AS THE SFC WARM FRONT INCHES NORTH...A STRONG LOW LEVEL JET WILL DEVELOP WITH GOOD MOISTURE TRANSPORT AND CONVERGENCE FOCUSED ON THE NOSE OF THE LLJ INTO NORTHEAST IA AND FAR SOUTHERN WI. GUIDANCE ALSO HINTS AT A MIDLEVEL SHORTWAVE RIDING IN ON SOUTHWEST FLOW. DESPITE SOME MODELS SUGGESTING CONTRARY...CONTINUE TO THINK THAT FOCUS FOR CONVECTION TONIGHT WILL REMAIN MAINLY NORTH OF THE CWA...THOUGH COULD CLIP THE FAR NORTH...WHERE GENERALLY SLIGHT POPS WERE MAINTAINED LATE EVE THROUGH OVERNIGHT. GIVEN PRESENCE OF MODERATE MUCAPE AND STRONG EFFECTIVE DEEP LAYER SHEAR...IF ANY STORMS DO OCCUR OVER THE FAR NORTH...STRONGER STORMS COULD YIELD ISOLATED SEVERE HAIL. LOW TEMPS WILL RANGE FROM MID 40S IN FAR NORTHEAST NEAR THE LAKE TO AROUND 60 IN THE SOUTHWEST CWA. WEDNESDAY AND WEDNESDAY NIGHT... MAIN UNCERTAINTY IS WITH TIMING OF SFC WARM FRONT LIFTING NORTH THROUGH CWA...THOUGH HAVE SOME CONCERN FOR ELEVATED HIGH-BASED CONVECTION NORTH OF THE WARM FRONT DURING THE MORNING MAINLY NORTH OF I-88. PRIMARY FOCUS SHOULD STILL BE NORTH OF THE CWA...BUT DID ADD A SLIGHT POP FOR AREA MENTIONED ABOVE. BIG STORY TOMORROW IS THE RAPID FLIP TO SUMMER WARMTH AS THE WARM FRONT LIFTS NORTH AS 850/925 MB TEMPS RISE TO LEVELS SUPPORTING AT LEAST LOW-MID 80S IN THE WARM SECTOR. SOME HIGH RES GUIDANCE REALLY SLOWS THE NWD PROGRESS OF THE FRONT TOMORROW...BUT THESE MODELS SUCH AS THE NAM ARE LIKELY AFFECTED BY OUTFLOW FROM OVERNIGHT CONVECTION. THE IL NORTH SHORE WILL LIKELY REMAIN QUITE COOL INTO THE AFTERNOON BUT THEN THE WARM AIR SOUTH OF THE BOUNDARY WILL RUSH IN BY THE LATE AFTERNOON OR EARLY EVENING...WITH TEMPS JUMPING SEVERAL DEGREES. DEWPOINTS WILL ALSO RISE TO CLOSE TO OR AROUND 60 AS THE FRONT LIFTS NORTH...ADDING A BIT OF A MUGGY FEEL TO THE AIRMASS. THE AREA SHOULD BE CAPPED TO CONVECTION ON WEDNESDAY NIGHT WITH NO REAL FOCUS TO BREACH THE CAP SO HAVE MAINTAINED A DRY FCST. OVERNIGHT TEMPS WILL BE NORMAL FOR MID SUMMER IN THE MID AND UPPER 60S. THIS WILL PROVIDE A WARM STARTING POINT FOR THURSDAY. THURSDAY AND THURSDAY NIGHT... CONTINUE TO SUSPECT AFTER EXAMINING FORECAST SOUNDINGS THAT MUCH IF NOT ALL OF THE AREA COULD SEE A MAINLY DRY DAYTIME WITH THE WARM SECTOR FIRMLY IN PLACE AND A STRONG CAP INDICATED. MOST OF THE MIDLEVEL SHORTWAVE FORCING DURING DAY SHOULD AT MOST SKIRTH THE FAR NORTHWEST CWA AND SFC COLD FRONT WILL BE WELL BACK TO THE WEST UNTIL THE NIGHTTIME. HAVE MAINTAINED GENERAL IDEA OF GRADUALLY SPREADING IN CHANCE POPS BUT BASED ON TRENDS TODAY...COULD FORSEE NEEDING TO LOWER THESE. THIS IS DESPITE HIGHS AGAIN IN THE MID 80S AND DEWPOINTS AROUND 60 SUPPORTING MODERATE MLCAPE VALUES. MORE FAVORABLE FORCING WILL ARRIVE DURING THE EVENING AND THEN MOISTURE CONVERGENCE ASSOCIATED WITH THE APPROACHING COLD FRONT WILL SUPPORT HIGHER SHOWER/TSTM COVERAGE OVERNIGHT. ARGUING AGAINST WIDESPREAD SEVERE STORMS WILL BE DIURNALLY UNFAVORABLE TIMING...BUT ESPECIALLY WESTERN CWA COULD HAVE ENOUGH INSTABILITY STILL IN PLACE ALONG WITH STRONG DEEP LAYER SHEAR TO SUPPORT A WIND/HAIL THREAT. WITH FRONT REMAINING TO THE WEST THROUGH THE NIGHT...OVERNIGHT TEMPS WILL AGAIN BE QUITE MILD IN THE MID 60S. FRIDAY... REMAINS OF OVERNIGHT CONVECTION SHOULD BE MOVING INTO EAST/SOUTHEAST CWA DURING MORNING...BUT WITH COLD FRONT ONLY MAKING SLOW PROGRESS AND AIR MASS STILL BEING WARM/MOST...WILL HAVE TO WATCH FOR REGENERATION OF STRONGER CONVECTION IN THE SOUTHEAST DURING THE AFTERNOON INTO THE EARLY EVENING. 850/925 MB TEMPS WILL REMAIN IN TEENS CELSIUS THROUGH AFTN SO HIGHS SHOULD REACH THE LOWER-MID 70S. LONG TERM...FRIDAY NIGHT THROUGH TUESDAY... UNLIKE WHAT WE HAVE SEEN AFTER PREVIOUS WARM SPELLS THIS SPRING...WE DO NOT LOOK TO RETURN TO A MUCH COOLER THAN NORMAL PATTERN AFTER THE PASSAGE OF THE LATE WEEK SYSTEM. THE JET STREAM PATTERN LOOKS TO REMAIN MORE ZONAL...WHICH WILL SUPPORT NORMAL TO SLIGHTLY ABOVE NORMAL TEMPS AND POSSIBLY MORESO AS PER 12Z OPERATIONAL EUROPEAN MODEL EARLY NEXT WEEK. UNCERTAINTY INCREASES IN THE OPERATIONAL AND ENSEMBLE MODELS...BUT IT APPEARS AFTER A PRIMARILY DRY SATURDAY...THE PATTERN COULD BE A BIT UNSETTLED WITH PERIODIC TSRA CHANCES. TIMING IS THE MAIN QUESTION AS THE GFS IS MUCH MORE PROGRESSIVE WITH THE NEXT SYSTEM. AS ALLUDED TO ABOVE...THIS WILL ALSO IMPACT HOW WARM TEMPERATURES GET EARLY NEXT WORK WEEK. CONFIDENCE IS ALSO LOWER ON WHICH DAYS ARE MOST SYNOPTICALLY FAVORABLE FOR ONSHORE FLOW KEEPING AT LEAST PORTIONS OF THE LAKEFRONT MUCH COOLER THAN INLAND. RC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * ISOLATED TSRA EARLY THIS MORNING NORTH OF ORD. * WARM FRONT AND ASSOCIATED WIND DIRECTIONS/SPEEDS FROM SUNRISE THROUGH LATE AFTERNOON. //DISCUSSION...UPDATED 06Z... ISOLATED THUNDERSTORMS ARE STILL POSSIBLE ACROSS FAR NORTHEAST IA AND FAR NORTHWEST IL THROUGH DAYBREAK AS AN UPPER LEVEL RIDGE BUILDS NORTH ACROSS THE REGION. ANYTHING THAT FORMS WILL LIFT NORTHEAST AND NOT EXPECTING ANY OF THIS ACTIVITY TO REACH THE CHICAGO AREA TERMINALS...REMAINING NORTH OF ORD/DPA. DURATION WILL ALSO BE RATHER SHORT AT RFD...BUT CONFIDENCE FOR TIMING IS LOW SO MAINTAINED CURRENT 08Z-11Z TIMING. DAYLIGHT HOURS TODAY INTO TONIGHT ARE EXPECTED TO BE DRY ACROSS THE ENTIRE AREA. A WARM FRONT CURRENTLY EXTENDS FROM NORTHERN MISSOURI AND ACROSS CENTRAL ILLINOIS AND WILL SLOWLY LIFT NORTH THIS MORNING AND SHOULD REACH THE I-80 CORRIDOR BY LATE MORNING. ITS PROGRESS NORTH COULD BE SLOWED BY THE COLDER AIR OVER LAKE MICHIGAN AND HOW FAST IT ADVANCES NORTH FIRST TO MDW AND THEN TO ORD/DPA IS SOMEWHAT UNCERTAIN AND MAINTAINED CURRENT TIMING FROM PREVIOUS FORECASTS. ITS POSSIBLE THAT THIS FRONTAL BOUNDARY MAY STALL IN AND AROUND ORD/MDW WITH SOME GUIDANCE SHOWING SOUTHERLY WINDS TURNING BACK SOUTHEASTERLY LATE IN THE AFTERNOON. UPDATES/CHANGES TO THIS WIND FORECAST CAN BE EXPECTED AS THE FRONT APPROACHES LATER THIS MORNING INTO THIS AFTERNOON AND TIMING/SPEED BECOMES MORE CERTAIN. CMS //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM ANY TSRA EARLY THIS MORNING WILL REMAIN NORTH OF ORD. * MEDIUM FOR WIND DIRECTIONS/SPEEDS THROUGH SUNRISE...THEN LOW THIS MORNING AND THIS AFTERNOON AS WARM FRONT LIFTS NORTH. CMS //OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z... * THURSDAY...CHANCE OF TSRA IN THE AFTERNOON. GUSTY SOUTHERLY WINDS. * THURSDAY NIGHT...TSRA LIKELY. * FRIDAY...CHANCE OF TSRA. GUSTY WESTERLY WINDS. * SATURDAY...DRY/VFR. * SUNDAY AND MONDAY...CHANCE OF TSRA. KJB && .MARINE... 302 PM CDT HIGH PRESSURE EXTENDS FROM HUDSON BAY TO THE MID ATLANTIC WHILE LOW PRESSURE REMAINS NEARLY STATIONARY AND SLOWLY DEEPENS OVER THE CENTRAL PLAINS. A WARM FRONT EXTENDING EAST FROM THE LOW...THROUGH THE OHIO VALLEY WILL REMAIN NEARLY STATIONARY...WITH ANY NORTHWARD PROGRESS BLOCKED BY THE HIGH. THIS WILL KEEP BRISK EASTERLY FLOW OVER LAKE MICHIGAN UNTIL THE WARM FRONT CAN PUSH TO THE NORTH. BY LATE WEDNESDAY MORNING...THE HIGH WILL BEGIN TO SLIDE TO THE EAST...ALLOWING THE WARM FRONT TO SURGE NORTHWARD. THE PARENT LOW IS EXPECTED TO TRACK TO THE NORTHEAST AND BECOME ELONGATED THROUGH WEDNESDAY NIGHT AND INTO THURSDAY...WITH THE WARM FRONT REACHING THE FAR NORTH END OF THE LAKE BY THURSDAY AFTERNOON...WITH WINDS TURNING SOUTHERLY. THE WARM FRONT SHOULD FINALLY REACH THE FAR SOUTHERN TIP OF THE LAKE BY LATE WEDNESDAY MORNING...ALLOWING FLOW TO TURN OFFSHORE OF THE INDIANA COAST. THE FRONT SHOULD PUSH SOUTH OF THE ILLINOIS NEARSHORE WATERS BY LATE AFTERNOON...SO WILL NOT MAKE ANY CHANGES TO THE GOING SMALL CRAFT ADVISORY AT THIS TIME. THE SOUTHERLY GRADIENT WILL TIGHTEN THURSDAY INTO EARLY FRIDAY...ALLOWING SOUTHERLY WINDS TO STRENGTHEN...BUT VERY WARM AIR OVERSPREADING THE COLD LAKE WATER SHOULD HELP LIMIT MIXING...ESPECIALLY OVER THE OPEN WATERS. THE NEARSHORE WATERS ARE BEGINNING TO GET A BIT WARMER...SO THERE COULD BE BETTER MIXING THERE AND WIND SPEEDS MAY FLIRT WITH GALE FORCE...BUT FOR NOW...FEEL THAT 30KT SOUTHERLY WINDS SHOULD BE THE PREVAILING CONDITION FOR THURSDAY INTO EARLY FRIDAY AFTERNOON. BY LATE FRIDAY AFTERNOON OR EARLY FRIDAY EVENING...THE LOW WILL TRACK NORTH OF THE GREAT LAKES TO NEAR JAMES BAY. AN ASSOCIATED COLD FRONT WILL SWEEP ACROSS THE LAKE FRIDAY AFTERNOON...TURNING WINDS TO WESTERLY BY FRIDAY EVENING. HIGH PRESSURE WILL THEN BUILD ACROSS THE LAKE BEGINNING FRIDAY NIGHT AND REMAINING IN PLACE INTO SUNDAY MORNING. WHILE THE HIGH PRESSURE RESIDES OVER THE LAKE...WINDS SHOULD BE RELATIVELY LIGHT WITH LAKE BREEZE DEVELOPMENT POSSIBLE. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM WEDNESDAY. SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 PM WEDNESDAY. && $$ 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
NWS GOODLAND KS
226 AM MDT WED MAY 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 225 AM MDT WED MAY 7 2014 EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW DEEPENING TROUGH CURRENTLY CENTERED OVER THE GREAT BASIN WITH SW FLOW EXTENDING ACROSS CENTRAL ROCKIES AND PLAINS. AT THE SURFACE LOW PRESSURE CURRENTLY EXTENDS FROM EASTCENTRAL COLORADO ACROSS THE TRI STATE REGION WITH A STATIONARY FRONT BISECTING THIS FEATURE GENERALLY ALONG AND SOUTH OF INTERSTATE 70. A DRY LINE EXTENDING ACROSS CENTRAL KS HAS BEEN BACKING UP TOWARDS THE EASTERN PART OF OUR CWA. PARTICULARLY LOW CONFIDENCE IN FORECAST FOR TODAY AS A RESULT OF THE LINGERING STATIONARY FRONT AND INCONSISTENCIES BETWEEN GUIDANCE ON EVOLUTION OF SURFACE LOW AND FRONT TIMING AS UPPER TROUGH SHIFTS EAST INTO THE PLAINS. THIS IS A REFLECTION OF MODEL DIFFERENCES ON EVOLUTION/TRACK OF CLOSED H5/H7 LOW CENTERS ACROSS THE PLAINS TODAY/TONIGHT. WE COULD SEE WIDE RANGING IMPACTS DEPENDING ON ALL OF THE ABOVE MENTIONED VARIANCES ON BOTH OUR RFW...A POSSIBLE WIND ADVISORY...AND POTENTIAL SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE NORTHERN HALF OF OUR CWA. THERE IS SO MUCH SPREAD BETWEEN MODELS FROM THE I-70 CORRIDOR NORTH ALL I WAS UNCOMFORTABLE DOING MORE THAN NUDGING TOWARDS THE LATEST BLENDS/NAM TRENDS. THIS PUTS THE SE HALF OF OUR CWA NEAR WIND ADVISORY CRITERIA...AND ANOTHER ROW OF COUNTIES WITHIN RFW CRITERIA. REGARDING THE CURRENT RFW AND POSSIBLE WIND ADVISORY...CONFIDENCE IS JUST TOO LOW TO MAKE HIGHLIGHT CHANGES. BASED ON EVOLUTION OF SURFACE FEATURES WE COULD SEE THUNDERSTORM INITIATION AND SEVERE POTENTIAL BY MIDDAY FURTHER SOUTH (I-70 CORRIDOR) BEFORE ANY PRIMARY THUNDERSTORM CHANCES TRANSITION NORTH AND WEST. WE WILL NEED TO MONITOR AND ADJUST AS CONFIDENCE INCREASE BASED ON REAL TIME DATA AND NEW RUNS OF SHORT RANGE GUIDANCE TO GET A BETTER HANDLE ON SENSIBLE WEATHER OVER OUR CWA THROUGH THIS EVENING. AS UPPER LOW TRANSITIONS EAST A COLD FRONT EVENTUALLY WILL PUSH SOUTH TONIGHT BEFORE STALLING ACROSS THE SOUTHERN PART OF OUR CWA. BESIDES COMPLICATING THE TEMP FORECAST...THIS FEATURE COULD ACT AS A FOCUS FOR ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT AS A SECONDARY SHORTWAVE TROUGH MOVES ACROSS THE NORTHERN PLAINS BEHIND THE INITIAL UPPER LOW. I USED A CONSENSUS BLEND OF TEMPS THROUGH FRI AND LINGERED POPS THROUGH FRI NIGHT TO ACCOUNT FOR LIFT/MOISTURE ALONG FRONT AND ASSOCIATE WITH WEAK TROUGH PASSAGE. WHILE TEMPS SHOULD RETURN TO NEAR SEASONAL VALUES...IT DOES LOOK LIKE WE HAVE POTENTIAL FOR LOW TEMPS TO DROP WELL BELOW NORMAL IN THE 30S...AND ACTUALLY WITHIN FROST ADVISORY CRITERIA. .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 215 AM MDT WED MAY 7 2014 WESTERLY ZONAL FLOW ALOFT WILL BE PRESENT ACROSS THE HIGH PLAINS SATURDAY...WHICH WILL BRING BENIGN CONDITIONS ACROSS THE FORECAST AREA. A POSITIVELY TILTED UPPER LEVEL TROUGH WILL BEGIN TO MOVE INTO THE GREAT BASIN REGION AND CONTINUE TO PROGRESS INTO THE TRI STATE AREA SATURDAY NIGHT. MODEL RUNS DIFFER AS TO THE LOCATION OF THE ENSUING TROUGH AS WELL AS THE TIMING OF THE PASSAGE OF THE TROUGH AXIS THROUGH THE REGION...BUT THIS WEATHER MAKING SYSTEM SHOULD AFFECT THE AREA SOMETIME BETWEEN THE SATURDAY NIGHT TO MONDAY NIGHT TIME FRAME. MOST MODEL FORECASTS INDICATE A SHORTWAVE RIDGE WILL MOVE INTO THE HIGH PLAINS ONCE THE TROUGH AXIS MOVES EASTWARD ON TUESDAY...BUT THE GEM MODEL HAS THE UPPER LEVEL LOW SYSTEM BECOMING CUT OFF OVER THE HIGH PLAINS REGION. TENDED TO SIDE WITH THE DRY FORECAST AS THE ECMWF...GFS AND DGEX FORECASTS INDICATE THE RIDGE. THE MAIN CONCERN FOR THE LONG TERM FORECAST PERIOD WILL BE THE CHANCES FOR THUNDERSTORMS SATURDAY NIGHT THROUGH MONDAY. THUNDERSTORMS AND PRECIPITATION CHANCES MAY LINGER INTO TUESDAY IF THE FLOW ALOFT BECOMES CUT OFF...WHICH WILL AID IN MORE PRECIPITATION PRODUCTION. LATEST MODEL FORECASTS PLACE THE GREATEST MID AND LOWER LEVEL JET SPEEDS AND HIGHEST AREAS OF INSTABILITY WELL TO THE EAST OF THE FORECAST AREA FOR THE PERIOD FOR GREATEST PRECIPITATION POTENTIAL...SO THUNDERSTORM ACTIVITY IS NOT EXPECTED TO BECOME SEVERE. DUE TO THE ZONAL FLOW PATTERN SATURDAY FOLLOWED BY A PUSH OF COOLER AIR ALOFT WITH THE TROUGH PATTERN...TEMPERATURES THROUGH THE LONG TERM PERIOD WILL BE NEAR TO SLIGHTLY BELOW NORMAL WITH HIGHS GENERALLY IN THE MID 60S TO LOWER 70S. LOW TEMPERATURES WILL SPAN DURING THIS PERIOD BETWEEN THE LOW TO UPPER 40S...WITH SOME SPOTS IN EASTERN COLORADO DIPPING INTO THE UPPER 30S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1140 PM MDT TUE MAY 6 2014 VFR CONDITIONS WILL PREVAIL AT MCK AND GLD THROUGH THE TAF PERIOD. A WARM FRONT PUSHES NORTH ACROSS THE REGION DURING THE DAY ON WEDNESDAY AS A SURFACE LOW PRESSURE CENTER DEEPENS OVER EASTERN COLORADO. AS THE FRONT PASSES OVER THE TAF SITES BETWEEN 19-21Z...WINDS ARE EXPECTED TO TURN SOUTH AND BECOME GUSTY DURING THE AFTERNOON AND EVENING. THERE IS A POSSIBILITY OF PATCHY FOG DEVELOPING NEAR MCK BETWEEN 10Z-14Z WEDNESDAY MORNING AS TEMPERATURES COOL AND APPROACH THE DEWPOINT VALUES IN THE LOWER 50S WHICH WILL BRING THE BOUNDARY LAYER NEAR SATURATION. HAVE INCLUDED A PREVAILING CONDITION OF 6SM WITH A LOW CLOUD LAYER AT MCK AS A RESULT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING FROM 11 AM MDT /NOON CDT/ THIS MORNING TO 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ013>016-027>029-041-042. CO...RED FLAG WARNING FROM 11 AM THIS MORNING TO 9 PM MDT THIS EVENING FOR COZ253-254. NE...NONE. && $$ SHORT TERM...DR LONG TERM...MK AVIATION...LOCKHART
AREA FORECAST DISCUSSION...CORRECTED
NWS BALTIMORE MD/WASHINGTON DC
407 AM EDT WED MAY 7 2014 .SYNOPSIS... A STATIONARY FRONT JUST SOUTH OF THE AREA WILL RETURN NORTH AS A WARM FRONT TODAY. HOWEVER...HIGH PRESSURE BUILDING IN FROM THE NORTH WILL LIMIT PROGRESSION OF THE FRONT THROUGH THE AREA AND INSTEAD AN ONSHORE FLOW WILL DEVELOP AS THE HIGH PRESSURE DRIFTS OFFSHORE. THE FRONT MAY SAG SOUTHWARD AS A BACKDOOR COLD FRONT THURSDAY NIGHT. HIGH PRESSURE WILL REMAIN PARKED OFF THE SOUTHEAST COAST LATE IN THE WEEK AND THIS WEEKEND WITH SOUTHERLY RETURN FLOW YIELDING WARM AND HUMID CONDITIONS. && .NEAR TERM /THROUGH THURSDAY/... AS OF 08Z...1025MB SFC HIGH SOUTH OF JAMES BAY IN QUEBEC. A STATIONARY SFC FRONT IS CURRENTLY OVER CENTRAL VA...THOUGH IT IS DIFFICULT TO PINPOINT FROM SFC OBS/RADAR/SATELLITE. LIGHT SHOWERS OVER SWRN ZONES HAVE DISSIPATED FOR NOW...BUT REDEVELOPMENT IS EXPECTED. WITH MID LEVEL LAPSE RATES AROUND 6 C/KM...ELEVATED THUNDERSTORM DEVELOPMENT IS STILL POSSIBLE...WARRANTING AN ISOLATED THUNDER MENTION. WILL HAVE TO WATCH THE CONVECTIVE COMPLEX OVER MI/NWRN OH THAT WILL CONTINUE TO SHIFT SOUTHEAST IN ELEVATED UNSTABLE AIR. SPC MESOANALYSIS HAS 500 MUCAPE EXTENDING SOUTHEAST ACROSS THE SWRN HALF OF THE LWX CWA SO AS OF NOW THIS WOULD SPREAD ACROSS THE CENTRAL OR SOUTHERN PORTION OF THE CWA LATE THIS MORNING THROUGH MIDDAY. 06Z HRRR DEPICTS SOME REMNANTS CROSSING NRN/CNTRL PARTS OF THE CWA FROM 10 AM TO 2PM. THIS WILL ALL BE CLOSELY MONITORED WITH GRID UPDATES AS NECESSARY. TODAY...WARM FRONT LIFTS NORTH INTO THE AREA WITH CHANCE POPS SPREADING ACROSS THE DC METRO AREA THROUGH MIDDAY. HOWEVER...AS THE CANADIAN SFC HIGH PRESSURE SHIFTS SSE ACROSS NJ THIS AFTERNOON...AN ONSHORE FLOW DEVELOPS FOR THE WRN SHORE. A VORTMAX RIDES THE NWLY FLOW AS WELL...ALLOWING CHANCE POPS ACROSS NERN MD LATE THIS AFTERNOON AND EVENING (MAY BE EARLIER WITH ONGOING ACTIVITY ENTERING OHIO). MAX TEMP UNCERTAINTY TODAY DUE TO TIMING QUESTION OF WARM FRONT AND ONSHORE FLOW. MAV/MET/GMOS BLEND GAVE GREATER BALTIMORE AROUND 70F...SLOWLY INCREASING SW FROM THERE WITH MID 70S IN SHEN VLY AND VLYS WEST OF THERE. SFC HIGH SETS UP SSE OF DC WITH A SLY FLOW THEN THROUGH THURSDAY. MAINLY DRY THURSDAY WITH INCREASING TEMPS. QUESTION IS IF ONSHORE FLOW COMPONENT CAN HANG ON. THEREFORE...LOW 70S IN FOR HARFORD WITH LOW TO MID 80S FOR MOST OF THE REST OF THE CWA. WILL NEED TO WATCH FOR 90F IN SOUTHEAST. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... UPPER RIDGE AXIS PROGRESSES EWD OVER THE REGION THU NGT AND FRI MRNG. MODELS CONTINUE TO ADVERTISE HIPRES OFF THE NEW ENGLAND COAST RIDGING SWWD INTO THE AREA THU NGT AND A BACKDOOR COLD FRONT TO PUSH THRU NORTH-CENTRAL MD. ONSHORE FLOW ON THE COOL SIDE OF THE BOUNDARY COULD RESULT IN DEVELOPMENT OF STRATUS AND PATCHY DRIZZLE THU NGT. SWLY FLOW WILL STRENGTHEN ON FRI AS THE RIDGE AXIS MOVES OFFSHORE AND AN UPSTREAM TROUGH APPROACHES FROM THE CENTRAL CONUS. THE HIGH SUN ANGLE WILL CONTRIBUTE TO STRONG HEATING...ALLOWING ANY STRATUS EAST OF THE BLUE RIDGE TO MIX OUT BY MIDDAY. WARM AIRMASS UNDERNEATH THE RIDGE CHARACTERIZED BY +2SD 925 MB TEMPS WILL YIELD HIGHS IN THE 80S. DID RAISE MAX TEMPS A BIT ON FRI WITH SOME WARMER SPOTS IN CENTRAL VA HAVING THE POTENTIAL TO REACH 90F ASSUMING FULL HEATING. SUBSIDENCE INVERSION WEAKENS FRI AFTN AND FRI NGT IN ASSOCIATION WITH HEIGHT FALLS AHEAD OF THE APPROACHING TROUGH WILL HELP ERODE THE SUBSIDENCE INVERSION. MODELS SHOWING SOME POTENTIAL FOR CONVECTIVE DEVELOPMENT OVER THE MTS DURING THE PEAK HEATING HRS IN ASSOCIATION WITH LIFT FROM A LEADING MID-LVL SHORTWAVE ENERGY AND SFC PRESSURE TROUGH. INTRODUCED ISO COVERAGE OF TSTMS DURING THE AFTN AND EVE WITH SBCAPE AROUND 1000 J/KG. SHOWERS MAY SPREAD EWD TOWARD I-95 DURING THE EVE BEFORE MOST OF THE ACTIVITY WANES OVERNIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... MID- AND UPPER-LVL FLOW WILL FLATTEN OUT THIS WEEKEND AS THE MAIN ENERGY ASSOCIATED WITH AN UPPER TROUGH AND SFC LOW LIFTING NEWD INTO QUEBEC. A SWLY LLVL JET AHEAD OF THE TROUGH AND ON THE BACKSIDE OF THE BERMUDA HIGH WILL DRAW MOISTURE FROM THE GULF OF MEXICO TOWARD THE MID-ATLANTIC REGION. SHOWERS ARE LIKELY ON SAT AS FORCING FOR ASCENT WITH A SHORTWAVE TROUGH AND WITHIN RIGHT-ENTRANCE REGION OF ULVL JET STREAK SPREADING INTO THE AREA. CHANCE POPS OVER THE NRN PIEDMONT AND SRN MD INCREASE TO LIKELY N/W OF DC TO CATEGORICAL ALONG THE ALLEGHENY FRONT. KEPT AFTN TSTM COVERAGE ISO DUE TO FCST UNCERTAINTY WITH CLOUD COVER OVER THE AREA. MODEL SOUNDINGS FROM THE 00Z GFS SHOW A RATHER CLOUDY AND STABLE AIRMASS ON SAT WHILE THE 00Z ECMWF DEPICTS A GREATER POTENTIAL FOR HEATING AND TSTMS. SYNOPTIC PATTERN EXPECTED TO BECOME FAIRLY ZONAL ACROSS THE ERN HALF OF THE CONUS SUN AND MON. ABOVE NORMAL TEMPS AND SOMEWHAT HUMID WITH DEWPOINTS NEAR 60F) WILL CONTINUE THRU ERY NEXT WEEK WITH SLY RETURN FLOW IN THE LLVLS. ATTEMPTED TO KEEP CHANCES FOR PRECIP LOW DURING THIS TIME WITH A LACK OF ORGANIZED SYNOPTIC LIFT. A COLD FRONT WILL APPROACH FROM THE WEST MIDWEEK. STILL PLENTY OF DIFFERENCES BETWEEN TIMING OF FROPA. FCST FOLLOWS WPC GUIDANCE... GIVING US INCREASING CHANCES FOR SHOWERS AND STORMS TUE. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... MID LEVEL CLOUDS INCREASE AS WARM FRONT APPROACHES FROM THE SOUTH. WILL HAVE TO WATCH THUNDERSTORMS MOVING SOUTHEAST FROM CNTRL OH IN ELEVATED UNSTABLE AIR THIS MORNING THAT WILL APPROACH SOME OF THE TERMINALS (THOUGH THIS WILL ALSO HAVE TO BE WATCHED) EARLIER THAN THE GUIDANCE WHICH PROGS LATE AFTERNOON/EVENING. ONSHORE FLOW DEVELOPS TONIGHT WITH LOW CLOUDS...NEAR IFR THURSDAY MORNING BEFORE SLY FLOW SLOWLY CLEARS THE CONDS TO VFR FOR THE REST OF THURSDAY. A BACKDOOR COLD FRONT SHOULD MOVE THRU BWI-MTN THU NGT AND POTENTIALLY REACH DCA-IAD. MVFR/IFR CIGS IN STRATUS POSSIBLE THU NGT AND FRI MRNG ON THE COLD SIDE OF THE BOUNDARY. SCT SHRA AND ISO TSTM POSSIBLE IN THE MTS FRI AFTN/EVE. BETTER COVERAGE OF SHRA EXPECTED SAT WITH A DISTURBANCE MOVING THRU THE TERMINALS. IFR VSBYS POSSIBLE IN HEAVIER SHOWERS OR STORMS. S-SW WINDS MAY GUST 15-25 KT SAT AFTN. MAINLY VFR THRU THE REMAINDER OF THE WEEKEND. && .MARINE... NELY FLOW 10 TO 15 KT OVER THE WATERS WILL BECOME ELY THIS AFTERNOON AS HIGH PRESSURE BUILDS SOUTH TO NJ. WILL NEED TO WATCH THUNDERSTORM COMPLEX OVER OHIO FOR MIDDAY THUNDERSTORM POTENTIAL FOR THE BAY WITH ELEVATED INSTABILITY ACROSS THE REGION. FLOW BECOMES ELY THIS AFTERNOON...ESELY FOR SRN MD WATERS WHICH WILL CHANNEL UP THE TIDAL POTOMAC AND POSSIBLY THE TIDAL PATUXENT THIS EVENING. MARGINAL SCA UP FOR LOWER AND MIDDLE TIDAL POTOMAC AS WELL AS LOWER SRN MD WATERS STARTING THIS AFTERNOON...EXPANDING UP TO NORTH BEACH THIS EVENING. GUST POTENTIAL IS AROUND 20 KT. FLOW BECOMES MORE LIGHT AND VARIABLE THURSDAY AS HIGH PRESSURE MOVES SOUTHEAST OF THE AREA AND A WEAK PRESSURE PATTERN OCCURS OVER THE MD PART OF THE BAY. LGT SLY WINDS LATE THIS WEEK. A SCA MAY BE NEEDED FOR THE WATERS ON SAT AS S-SWLY FLOW INCREASES AHEAD OF A TROUGH OF LOPRES. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 2 AM EDT THURSDAY FOR ANZ533-542. SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 2 AM EDT THURSDAY FOR ANZ534-536-537-543. && $$ SYNOPSIS...JRK NEAR TERM...BAJ SHORT TERM...JRK LONG TERM...JRK AVIATION...BAJ/JRK MARINE...BAJ/JRK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
416 AM EDT WED MAY 7 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 322 PM EDT TUE MAY 6 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW BLDG UPR RDG/SFC HI PRES OVER THE UPR LKS BTWN TROF IN FAR ERN CANADA AND A PAIR OF CLOSED LOWS IN SPLIT FLOW ACRS THE W...ONE OVER ALBERTA AND THE OTHER DIGGING INTO THE DESERT SW. 12Z GRB/APX/MPX RAOBS INDICATE A DRY...STABLE AIRMASS IS IN PLACE...WITH PWAT AS LO AS 0.25 INCH AT APX. BUT THERE ARE PLENTY OF MID/HI CLDS ASSOCIATED WITH WAD/ ISENTROPIC ASCENT IN THE SW FLOW ALF BTWN THE HI OVER THE UPR LKS AND LOWER HGTS/MSLP TO THE W ASSOCIATED WITH THE WRN TROFFING. THERE IS A BAND OF THICKER MID LVL CLDS MOVING ENEWD THRU NE MN/WRN LK SUP AND TOWARD THE WRN LAND CWA ASSOCIATED WITH SHARPER ISENTROPIC ASCENT BEST SHOWN ON THE 300-305K SFCS...OR ABOUT H6-7...WELL TO THE NE OF DVLPG SFC-H85 WARM FNT IN THE CENTRAL PLAINS. BUT ADVECTION OF DRIER AIR IN THE LLVLS WITH STEADY ESE WINDS ON THE WRN FLANK OF THE SFC HI IS PREVENTING ANY PCPN FM REACHING THE GROUND E OF FAR WRN LK SUP. MAIN FCST CONCERN IN THE SHORTER TERM FOCUS ON PCPN CHCS ASSOCIATED WITH LARGER SCALE WAD/ISENTROPIC ASCENT TO THE NE OF WARM FNT NOW IN THE CENTRAL PLAINS. THIS AFTN/TNGT...ALTHOUGH HI CLDS WL SPILL OVER THE ENTIRE CWA THIS AFTN...BAND OF THICKER MID CLDS IS FCST TO IMPACT MAINLY THE NW PORTIONS OF THE CWA THIS AFTN BEFORE SHIFTING TO THE NE AFT SUNSET. THE LLVLS SHOULD REMAIN SUFFICIENTLY DRY TO KEEP PCPN FM REACHING THE SFC EVEN WHERE THE CLDS ARE THICKEST. THE PERIOD FM 00Z-06Z SHOULD BE DRY DESPITE CONSIDERABLE HI CLDS. WITH AN INCRSG H85 SW LLJ/THETA E ADVCTN/DEEP LYR QVECTOR CNVGC TNGT...MORE NMRS SHRA/TS ARE LIKELY TO DVLP AHEAD OF THE WARM FNT MOVING SLOWLY TO THE NE TOWARD SRN MN/WI BY 12Z. BUT SINCE THE SHARPER DEEP LYR QVECTOR CNVGC AND UPR DVGC ARE FCST TO REMAIN S OF UPR MI CLOSER TO THE WARM FNT...CORFIDI VECTORS FCST TO BE WNW IN WI TO THE N OF THE H85 WARM FNT WHICH WOULD RESULT IN MOST NMRS SHRA/TS REMAINING TO THE S AND ROBBING MSTR FOR PCPN FARTHER N...AND DRY AIR IS FCST TO LINGER IN THE SFC-H7 LYR WITHIN PERSISTENT ESE LLVL TRAJECTORIES...SUSPECT THE 12Z GFS IS TOO AGGRESSIVE TO LIFT PCPN INTO MUCH OF UPR MI BY 12Z WED. WL TREND THE FCST CLOSER TO THE DRIER 12Z NAM/REGIONAL CNDN MODELS. THIS GUIDANCE RESTRICTS QPF TO AREAS NEAR THE WI BORDER AND BAND OF SHARPER H85 FGEN. WL FCST HIER CHC POPS OVER SRN MENOMINEE COUNTY BUT GO WITH A DRY FCST FOR THE NE CWA. WED...SFC WARM FNT NEAR THE SRN MN/WI BORDER AND H85 WARM FNT INTO CENTRAL WI IS FCST TO REMAIN NEARLY STNRY THRU 00Z THU WELL TO THE NE OF DEEP TROF LINGERING IN THE DESERT SW. WELL TO THE NE OF THIS MAIN FORCING MECHANISM...12Z MODELS INDICATE DEEP LYR QVECTOR DVGC/SOME UPR CNVGC WL DOMINATE THRU MUCH OF THE AFTN UNDER INCRSGLY AMPLIFIED UPR RDG/HGT RISES TO THE N OF THE WARM FNT AND DIMINISHING DEEP LYR QVECTOR CNVGC THAT WL SUPPORT THE MAIN AREA OF SHRA/TS TO THE S AND SHIFT MAINLY TO THE E INTO THE LOWER LKS PARALLEL TO THE WARM FNT. SO SUSPECT THE MORE NMRS SHRA WL EXIT THE FAR SCENTRAL EARLY IN THE DAY AND LEAVE JUST ISOLD-SCT SHRA NEAR THE WI BORDER MOST OF THE DAY. INCLUDED MENTION OF SOME ELEVATED TS OVER THE FAR SCENTRAL LATER IN THE DAY TO ACCOUNT FOR AREA OF FCST LOWER SSI SHOWN BY THE MORE STABLE GFS. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 441 PM EDT TUE MAY 6 2014 WHEN...WHERE...AND HOW MUCH PRECIPITATION WILL FALL ALONG WITH THE THUNDERSTORM POTENTIAL WILL BE THE MAIN CONCERNS IN THIS LONG TERM PERIOD. THE SLIGHT RISK TS POTENTIAL FROM SPC IS ALONG THE WI BORDER FOR THE WEDNESDAY NIGHT PERIOD. ANOTHER CONCERN WITH THE WARMER AIR WILL BE FOG...WHICH IS STILL FCST TUESDAY NIGHT THROUGH FRIDAY...PARTICULARLY ACROSS LAKE SUPERIOR AND LAKE MI. THE 500MB LOW CURRENTLY ALONG THE ALBERTA AND SASKATCHEWAN BORDER AND TROUGH EXTENDING ACROSS NV AND S CA THIS AFTERNOON WILL EVER SO SLOWLY PROGRESS E...STRETCHING FROM SASKATCHEWAN THROUGH THE 4-CORNERS REGION BY 06Z THURSDAY...AS THE HIGH AMPLITUDE RIDGE CONTINUES TO BUILD ACROSS THE UPPER GREAT LAKES /WITH THE APEX OVER MAINLY CENTRAL AND E UPPER MI/. WENT WITH HIGH CHANCE TO LIKELY POPS FOR THE W HALF OF UPPER MI WEDNESDAY NIGHT...SO DESPITE THE SE WINDS...TEMPERATURES SHOULD BE ABLE TO COOL INTO THE LOW TO MID 40S. THE WARM FRONT LOOKS TO CROSS INTO S WI AROUND 00Z THURSDAY...WITH SEVERAL DISTURBANCES EJECTING NE INTO THE AREA TO KEEP CHANCE TO LIKELY POPS GOING THROUGH THURSDAY. THE WARMEST DAY OVER THE W HALF /PENDING RAIN SHOWER/ LOOKS TO BE THURSDAY AS 850MB TEMPS RISE TO A CWA AVG OF 18C. CURRENTLY FCSTING HIGHS IN THE MID TO UPPER 60S AS THE SFC LOW TRACKS ACROSS S MN AND EXTENDING UP THROUGH W LAKE SUPERIOR. JUST HOW FAR N THE WARM FRONT CAN PUSH ACROSS THE REGION WILL BE A CONCERN TS WISE. AT THIS POINT IT LOOKS LIKE THE WARM FRONT MAY HOOK UP THROUGH SW UPPER MI AND NEAR THE WI BORDER AT 12Z THURSDAY...BEFORE THE SFC LOW AND ASSOCIATED COLD FRONT CATCH UP TO IT AS THE LOW SHIFTS OVER E MN/NW WI AND THE W HALF OF UPPER MI BY 06Z FRIDAY. EXPECT THE LOW TO N OF LAKE SUPERIOR ACROSS ONTARIO BY MID DAY FRIDAY...DRAGGING THE INITIAL COLD FRONT E OF UPPER MI. THE SECONDARY FRONT MAY BRING SOME WRAP AROUND MOISTURE INTO THE W HALF OF THE CWA FOR THE REMAINDER OF FRIDAY...AS WINDS BECOME MORE W-NW. 850MB TEMPS SHOULD FALL TO AROUND 2C BY SATURDAY MORNING AS PW VALUES FALL TO AROUND 0.3IN...OR 45-60 PERCENT OF NORMAL. CURRENTLY HAVE UPPER 30S FCST FOR THE W THIRD OF THE CWA...BUT WOULD NOT BE SURPRISED IF IT ENDS UP BEING A BIT LOWER. CONTINUED THE TREND OF LOWERING DEW POINTS ON SATURDAY...AS DRY HIGH PRESSURE TEMPORARILY BUILDS ACROSS THE UPPER GREAT LAKES. THE NEXT LOW /PICKED UP MUCH BETTER CONSISTENCY WISE OFF THE 12Z GFS AND ECMWF/ LOOKS TO BE OVER S CANADA AND MN AT 12Z SUNDAY. LOOK FOR THE RETURN OF RAIN SHOWERS. KEPT ANY MENTION OF TS TO THE SW AT THIS TIME. PRECIP LOOKS TO CONTINUE INTO MONDAY...AS LOW PRESSURE LINGERS ACROSS THE REGION. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 107 AM EDT WED MAY 7 2014 ALTHOUGH SFC HIGH PRES RIDGE FROM NRN ONTARIO TO THE LWR LAKES WILL DRIFT E...DRIER E TO SE NEAR SFC FLOW EMANATING FROM THE RIDGE SHOULD WORK TO MAINTAIN VFR CONDITIONS AT KIWD/KCMX/KSAW THRU THIS FCST PERIOD. GRADUAL INCREASE IN MOISTURE/INSTABILITY ABOVE THE SHALLOW DRIER AIR WILL PROBABLY LEAD TO SOME SCT SHRA LIFTING INTO UPPER MI AT TIMES DESPITE WARM FRONT WELL S OF THE AREA. AT THIS POINT... THERE IS NOT MUCH CONFIDENCE IN PINNING DOWN BEST TIME PERIODS FOR PCPN. BEST CHC MAY BE AT KIWD LATER IN THE NIGHT AND THEN AGAIN THIS EVENING...SO VCSH WAS MENTIONED THERE. LLWS WAS INCLUDED OVERNIGHT AT KIWD/KSAW (LATEST KMQT RADAR VAD WIND PROFILE SHOWS SE WIND AROUND 30KT AT 500FT AGL). && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 415 AM EDT WED MAY 7 2014 LAKE SUPERIOR WILL INCREASINGLY COME UNDER THE INFLUENCE OF AN AREA OF LOW PRESSURE CURRENTLY FORMING OVER WESTERN KANSAS OVER THE NEXT TWO DAYS. EXPECT GENERAL EASTERLY FLOW OVER THE LAKE THROUGH THURSDAY...WITH A TREND MORE TO THE NORTHEAST OVER WESTERN HALF AND THE SOUTHEAST OVER THE EAST HALF. THIS FLOW WILL MAINLY PRODUCE WINDS UP TO 25KTS DURING THAT TIMEFRAME...WITH A FEW HIGHER GUSTS OVER FAR WESTERN LAKE SUPERIOR THROUGH TONIGHT WHERE THERE IS FAVORABLE FUNNELLING. AS THE LOW LIFTS ACROSS WESTERN LAKE SUPERIOR ON THURSDAY NIGHT AND EARLY FRIDAY MORNING...WINDS OVER THE EASTERN 2/3RD WILL SHIFT TO THE SOUTH AND REMAIN UP TO 25KTS. ALTHOUGH THERE WILL BE STRONGER WINDS ALOFT...EXPECT THE MARINE LAYER TO KEEP THE WINDS AT THE SURFACE LOWER. THE LOW WILL CONTINUE NORTHEAST TO JAMES BAY ON FRIDAY AND DRAG A TRAILING COLD FRONT ACROSS LAKE SUPERIOR ON FRIDAY...SHIFTING WINDS TO THE WEST. A HIGH PRESSURE RIDGE WILL MOVE OVER THE LAKE ON FRIDAY NIGHT AND REMAIN INTO SATURDAY...LEADING TO LIGHT WINDS. && .HYDROLOGY... ISSUED AT 309 PM EDT TUE MAY 6 2014 STREAMS AND RIVERS WILL CONTINUE TO EXPERIENCE HIGHER LEVELS. LOCATIONS STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER IN HOUGHTON AND BARAGA COUNTIES AND THE TAHQUAMENON RIVER NEAR PARADISE. WHILE WET WEATHER WILL RETURN LATE TONIGHT THROUGH FRIDAY EVENING...RAINFALL SHOULD AROUND A TENTH OF AN INCH OR LESS THROUGH THE DAY WEDNESDAY. AT THE CURRENT TIME MOST OF THE RAIN LOOKS TO FALL OVER THE STURGEON RIVER BASIN THURSDAY EVENING. ADDING TO THIS WILL BE THE FEW INCHES OF SNOW WATER EQUIVALENT BEING SHOWN FROM NOHRSC SET UP FROM THE TIP OF THE KEWEENAW PENINSULA THROUGH PAINESDALE...DONKEN...AND WINONA. THIS LINES UP WELL WITH THE LATEST SNOW DEPTHS REPORTED AT PAINESDALE AND HERMAN. WILL SEE HOW THIS SNOW MELT /GIVEN WARMER FCST TEMPS FOR THE REST OF THE WEEK/ IMPACTS DOWNSTREAM RIVERS INCLUDING THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES AND THE TRAP ROCK RIVER. MOST IF NOT ALL OF THE SNOW COULD MELT BY THIS WEEKEND. FLOWS WILL LIKELY INCREASE OUT OF THE PRICKETT DAM OVER THE NEXT DAY OR TWO...WHICH WILL LEAD TO CONTINUED HIGHER LEVELS ON THE STURGEON RIVER IN HOUGHTON/BARAGA COUNTIES. WITH THE ALREADY HIGH LEVELS...ALSM4/CLLM4 MAY REACH FLOOD STAGE. BACK TO THE WET WEATHER EXPECTED THROUGH FRIDAY EVENING...SEVERAL ROUNDS OF SHOWERS AND POTENTIALLY THUNDERSTORMS WILL AFFECT THE AREA DURING THE SECOND HALF OF THE WORK WEEK. RAINFALL AMOUNTS WILL LIKELY EXCEED A HALF OF AN INCH FOR MOST OF UPPER MICHIGAN...AND LOCALIZED AMOUNTS OVER AN INCH SHOULD OCCUR WHERE THUNDERSTORMS TRACK. THIS WILL KEEP THE RIVER LEVELS HIGH INTO NEXT WEEKEND. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KF AVIATION...ROLFSON MARINE...SRF HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
112 AM EDT WED MAY 7 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 322 PM EDT TUE MAY 6 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW BLDG UPR RDG/SFC HI PRES OVER THE UPR LKS BTWN TROF IN FAR ERN CANADA AND A PAIR OF CLOSED LOWS IN SPLIT FLOW ACRS THE W...ONE OVER ALBERTA AND THE OTHER DIGGING INTO THE DESERT SW. 12Z GRB/APX/MPX RAOBS INDICATE A DRY...STABLE AIRMASS IS IN PLACE...WITH PWAT AS LO AS 0.25 INCH AT APX. BUT THERE ARE PLENTY OF MID/HI CLDS ASSOCIATED WITH WAD/ ISENTROPIC ASCENT IN THE SW FLOW ALF BTWN THE HI OVER THE UPR LKS AND LOWER HGTS/MSLP TO THE W ASSOCIATED WITH THE WRN TROFFING. THERE IS A BAND OF THICKER MID LVL CLDS MOVING ENEWD THRU NE MN/WRN LK SUP AND TOWARD THE WRN LAND CWA ASSOCIATED WITH SHARPER ISENTROPIC ASCENT BEST SHOWN ON THE 300-305K SFCS...OR ABOUT H6-7...WELL TO THE NE OF DVLPG SFC-H85 WARM FNT IN THE CENTRAL PLAINS. BUT ADVECTION OF DRIER AIR IN THE LLVLS WITH STEADY ESE WINDS ON THE WRN FLANK OF THE SFC HI IS PREVENTING ANY PCPN FM REACHING THE GROUND E OF FAR WRN LK SUP. MAIN FCST CONCERN IN THE SHORTER TERM FOCUS ON PCPN CHCS ASSOCIATED WITH LARGER SCALE WAD/ISENTROPIC ASCENT TO THE NE OF WARM FNT NOW IN THE CENTRAL PLAINS. THIS AFTN/TNGT...ALTHOUGH HI CLDS WL SPILL OVER THE ENTIRE CWA THIS AFTN...BAND OF THICKER MID CLDS IS FCST TO IMPACT MAINLY THE NW PORTIONS OF THE CWA THIS AFTN BEFORE SHIFTING TO THE NE AFT SUNSET. THE LLVLS SHOULD REMAIN SUFFICIENTLY DRY TO KEEP PCPN FM REACHING THE SFC EVEN WHERE THE CLDS ARE THICKEST. THE PERIOD FM 00Z-06Z SHOULD BE DRY DESPITE CONSIDERABLE HI CLDS. WITH AN INCRSG H85 SW LLJ/THETA E ADVCTN/DEEP LYR QVECTOR CNVGC TNGT...MORE NMRS SHRA/TS ARE LIKELY TO DVLP AHEAD OF THE WARM FNT MOVING SLOWLY TO THE NE TOWARD SRN MN/WI BY 12Z. BUT SINCE THE SHARPER DEEP LYR QVECTOR CNVGC AND UPR DVGC ARE FCST TO REMAIN S OF UPR MI CLOSER TO THE WARM FNT...CORFIDI VECTORS FCST TO BE WNW IN WI TO THE N OF THE H85 WARM FNT WHICH WOULD RESULT IN MOST NMRS SHRA/TS REMAINING TO THE S AND ROBBING MSTR FOR PCPN FARTHER N...AND DRY AIR IS FCST TO LINGER IN THE SFC-H7 LYR WITHIN PERSISTENT ESE LLVL TRAJECTORIES...SUSPECT THE 12Z GFS IS TOO AGGRESSIVE TO LIFT PCPN INTO MUCH OF UPR MI BY 12Z WED. WL TREND THE FCST CLOSER TO THE DRIER 12Z NAM/REGIONAL CNDN MODELS. THIS GUIDANCE RESTRICTS QPF TO AREAS NEAR THE WI BORDER AND BAND OF SHARPER H85 FGEN. WL FCST HIER CHC POPS OVER SRN MENOMINEE COUNTY BUT GO WITH A DRY FCST FOR THE NE CWA. WED...SFC WARM FNT NEAR THE SRN MN/WI BORDER AND H85 WARM FNT INTO CENTRAL WI IS FCST TO REMAIN NEARLY STNRY THRU 00Z THU WELL TO THE NE OF DEEP TROF LINGERING IN THE DESERT SW. WELL TO THE NE OF THIS MAIN FORCING MECHANISM...12Z MODELS INDICATE DEEP LYR QVECTOR DVGC/SOME UPR CNVGC WL DOMINATE THRU MUCH OF THE AFTN UNDER INCRSGLY AMPLIFIED UPR RDG/HGT RISES TO THE N OF THE WARM FNT AND DIMINISHING DEEP LYR QVECTOR CNVGC THAT WL SUPPORT THE MAIN AREA OF SHRA/TS TO THE S AND SHIFT MAINLY TO THE E INTO THE LOWER LKS PARALLEL TO THE WARM FNT. SO SUSPECT THE MORE NMRS SHRA WL EXIT THE FAR SCENTRAL EARLY IN THE DAY AND LEAVE JUST ISOLD-SCT SHRA NEAR THE WI BORDER MOST OF THE DAY. INCLUDED MENTION OF SOME ELEVATED TS OVER THE FAR SCENTRAL LATER IN THE DAY TO ACCOUNT FOR AREA OF FCST LOWER SSI SHOWN BY THE MORE STABLE GFS. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 441 PM EDT TUE MAY 6 2014 WHEN...WHERE...AND HOW MUCH PRECIPITATION WILL FALL ALONG WITH THE THUNDERSTORM POTENTIAL WILL BE THE MAIN CONCERNS IN THIS LONG TERM PERIOD. THE SLIGHT RISK TS POTENTIAL FROM SPC IS ALONG THE WI BORDER FOR THE WEDNESDAY NIGHT PERIOD. ANOTHER CONCERN WITH THE WARMER AIR WILL BE FOG...WHICH IS STILL FCST TUESDAY NIGHT THROUGH FRIDAY...PARTICULARLY ACROSS LAKE SUPERIOR AND LAKE MI. THE 500MB LOW CURRENTLY ALONG THE ALBERTA AND SASKATCHEWAN BORDER AND TROUGH EXTENDING ACROSS NV AND S CA THIS AFTERNOON WILL EVER SO SLOWLY PROGRESS E...STRETCHING FROM SASKATCHEWAN THROUGH THE 4-CORNERS REGION BY 06Z THURSDAY...AS THE HIGH AMPLITUDE RIDGE CONTINUES TO BUILD ACROSS THE UPPER GREAT LAKES /WITH THE APEX OVER MAINLY CENTRAL AND E UPPER MI/. WENT WITH HIGH CHANCE TO LIKELY POPS FOR THE W HALF OF UPPER MI WEDNESDAY NIGHT...SO DESPITE THE SE WINDS...TEMPERATURES SHOULD BE ABLE TO COOL INTO THE LOW TO MID 40S. THE WARM FRONT LOOKS TO CROSS INTO S WI AROUND 00Z THURSDAY...WITH SEVERAL DISTURBANCES EJECTING NE INTO THE AREA TO KEEP CHANCE TO LIKELY POPS GOING THROUGH THURSDAY. THE WARMEST DAY OVER THE W HALF /PENDING RAIN SHOWER/ LOOKS TO BE THURSDAY AS 850MB TEMPS RISE TO A CWA AVG OF 18C. CURRENTLY FCSTING HIGHS IN THE MID TO UPPER 60S AS THE SFC LOW TRACKS ACROSS S MN AND EXTENDING UP THROUGH W LAKE SUPERIOR. JUST HOW FAR N THE WARM FRONT CAN PUSH ACROSS THE REGION WILL BE A CONCERN TS WISE. AT THIS POINT IT LOOKS LIKE THE WARM FRONT MAY HOOK UP THROUGH SW UPPER MI AND NEAR THE WI BORDER AT 12Z THURSDAY...BEFORE THE SFC LOW AND ASSOCIATED COLD FRONT CATCH UP TO IT AS THE LOW SHIFTS OVER E MN/NW WI AND THE W HALF OF UPPER MI BY 06Z FRIDAY. EXPECT THE LOW TO N OF LAKE SUPERIOR ACROSS ONTARIO BY MID DAY FRIDAY...DRAGGING THE INITIAL COLD FRONT E OF UPPER MI. THE SECONDARY FRONT MAY BRING SOME WRAP AROUND MOISTURE INTO THE W HALF OF THE CWA FOR THE REMAINDER OF FRIDAY...AS WINDS BECOME MORE W-NW. 850MB TEMPS SHOULD FALL TO AROUND 2C BY SATURDAY MORNING AS PW VALUES FALL TO AROUND 0.3IN...OR 45-60 PERCENT OF NORMAL. CURRENTLY HAVE UPPER 30S FCST FOR THE W THIRD OF THE CWA...BUT WOULD NOT BE SURPRISED IF IT ENDS UP BEING A BIT LOWER. CONTINUED THE TREND OF LOWERING DEW POINTS ON SATURDAY...AS DRY HIGH PRESSURE TEMPORARILY BUILDS ACROSS THE UPPER GREAT LAKES. THE NEXT LOW /PICKED UP MUCH BETTER CONSISTENCY WISE OFF THE 12Z GFS AND ECMWF/ LOOKS TO BE OVER S CANADA AND MN AT 12Z SUNDAY. LOOK FOR THE RETURN OF RAIN SHOWERS. KEPT ANY MENTION OF TS TO THE SW AT THIS TIME. PRECIP LOOKS TO CONTINUE INTO MONDAY...AS LOW PRESSURE LINGERS ACROSS THE REGION. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 107 AM EDT WED MAY 7 2014 ALTHOUGH SFC HIGH PRES RIDGE FROM NRN ONTARIO TO THE LWR LAKES WILL DRIFT E...DRIER E TO SE NEAR SFC FLOW EMANATING FROM THE RIDGE SHOULD WORK TO MAINTAIN VFR CONDITIONS AT KIWD/KCMX/KSAW THRU THIS FCST PERIOD. GRADUAL INCREASE IN MOISTURE/INSTABILITY ABOVE THE SHALLOW DRIER AIR WILL PROBABLY LEAD TO SOME SCT SHRA LIFTING INTO UPPER MI AT TIMES DESPITE WARM FRONT WELL S OF THE AREA. AT THIS POINT... THERE IS NOT MUCH CONFIDENCE IN PINNING DOWN BEST TIME PERIODS FOR PCPN. BEST CHC MAY BE AT KIWD LATER IN THE NIGHT AND THEN AGAIN THIS EVENING...SO VCSH WAS MENTIONED THERE. LLWS WAS INCLUDED OVERNIGHT AT KIWD/KSAW (LATEST KMQT RADAR VAD WIND PROFILE SHOWS SE WIND AROUND 30KT AT 500FT AGL). && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 322 PM EDT TUE MAY 6 2014 AS THE PRES GRADIENT TIGHTENS OVER LAKE SUPERIOR ON THE SW FLANK OF HI PRES RETREATING THRU ONTARIO AND IN ADVANCE OF LO PRES/ATTENDANT WARM FRONT LIFTING NE FROM THE PLAINS...EXPECT SLOWLY VEERING NE TO SE WINDS UP TO 15-25 KTS TO DOMINATE INTO THU. AS HIGHER DEW POINTS ARRIVE ON WED NIGHT/THU...FOG WILL DEVELOP OVER THE COLDER/ICE COVERED LAKE WATERS. WINDS WILL THEN VEER FROM THE SE TO THE W ON THU NIGHT THRU SAT AS THE LOW PRES TRACKS OVER FAR WESTERN LAKE SUPERIOR AND INTO NW ONTARIO. THE ARRIVAL OF DRIER AIR IN THE WAKE OF THIS LOW WILL CAUSE THE FOG TO DISSIPATE FRI NIGHT. WINDS WILL THEN SHIFT TO THE E ON SUN AS THE HI PRES TRAILING THE DEPARTING LO MOVES TO THE E. NO GALES SEEN IN THIS FORECAST PERIOD. && .HYDROLOGY... ISSUED AT 309 PM EDT TUE MAY 6 2014 STREAMS AND RIVERS WILL CONTINUE TO EXPERIENCE HIGHER LEVELS. LOCATIONS STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER IN HOUGHTON AND BARAGA COUNTIES AND THE TAHQUAMENON RIVER NEAR PARADISE. WHILE WET WEATHER WILL RETURN LATE TONIGHT THROUGH FRIDAY EVENING...RAINFALL SHOULD AROUND A TENTH OF AN INCH OR LESS THROUGH THE DAY WEDNESDAY. AT THE CURRENT TIME MOST OF THE RAIN LOOKS TO FALL OVER THE STURGEON RIVER BASIN THURSDAY EVENING. ADDING TO THIS WILL BE THE FEW INCHES OF SNOW WATER EQUIVALENT BEING SHOWN FROM NOHRSC SET UP FROM THE TIP OF THE KEWEENAW PENINSULA THROUGH PAINESDALE...DONKEN...AND WINONA. THIS LINES UP WELL WITH THE LATEST SNOW DEPTHS REPORTED AT PAINESDALE AND HERMAN. WILL SEE HOW THIS SNOW MELT /GIVEN WARMER FCST TEMPS FOR THE REST OF THE WEEK/ IMPACTS DOWNSTREAM RIVERS INCLUDING THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES AND THE TRAP ROCK RIVER. MOST IF NOT ALL OF THE SNOW COULD MELT BY THIS WEEKEND. FLOWS WILL LIKELY INCREASE OUT OF THE PRICKETT DAM OVER THE NEXT DAY OR TWO...WHICH WILL LEAD TO CONTINUED HIGHER LEVELS ON THE STURGEON RIVER IN HOUGHTON/BARAGA COUNTIES. WITH THE ALREADY HIGH LEVELS...ALSM4/CLLM4 MAY REACH FLOOD STAGE. BACK TO THE WET WEATHER EXPECTED THROUGH FRIDAY EVENING...SEVERAL ROUNDS OF SHOWERS AND POTENTIALLY THUNDERSTORMS WILL AFFECT THE AREA DURING THE SECOND HALF OF THE WORK WEEK. RAINFALL AMOUNTS WILL LIKELY EXCEED A HALF OF AN INCH FOR MOST OF UPPER MICHIGAN...AND LOCALIZED AMOUNTS OVER AN INCH SHOULD OCCUR WHERE THUNDERSTORMS TRACK. THIS WILL KEEP THE RIVER LEVELS HIGH INTO NEXT WEEKEND. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KF AVIATION...ROLFSON MARINE...KC HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
434 AM CDT WED MAY 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 434 AM CDT WED MAY 7 2014 SURFACE WARM FRONT THIS MORNING WAS JUST CROSSING THE BORDER FROM MO INTO IA AND IS ASSOCIATED WITH A 995 MB SFC LOW IN THE VICINITY OF CO/KS/NEB. THERE ARE A COUPLE OF BANDS OF STORMS OUT THERE THIS MORNING. ONE EXTENDS FROM CLEVELAND BACK TO GREEN BAY THAT YOU CAN FOLLOW BACK TO SHOWERS IN THE DULUTH AREA AND ASSOCIATED WITH THE ARRIVAL OF THE ELEVATED CAPE. AT THE NOSE OF THE LLJ AND EDGE OF THE CAPPING INVERSION /WHERE H7 TEMPS EXCEED +9C/ YOU WILL FIND A BROKEN LINE OF STORMS ALONG THE MN/IA. MPXWRF AND SPCWRF PRETTY MUCH NAILED THESE STORMS...SO FOLLOWED THE TREND OF THESE MODELS FOR WORKING HIGHER POPS SOUTH OF A MANKATO/RED WING/CHIP FALLS LINE THROUGH THE MORNING. GIVEN THE RAPS DEPICTION OF THE LLJ VEERING MORE EASTERLY THROUGH THE MORNING WITH LITTLE DEVELOPMENT NORTH...IT MAKES SENSE THAT THESE STORMS WILL NOT BUILD MUCH FARTHER NORTH OF THEIR CURRENT LATITUDE AND WILL INSTEAD HEAD MORE OR LESS DOWN I-90 INTO CENTRAL WI WITH THE LLJ. NOT EXPECTING MUCH SEVERE POTENTIAL OUT OF THESE...BUT WITH EFFECTIVE SHEAR UP NEAR 30 KTS AND CAPE BETWEEN -10C AND -30C /HAIL CAPE/ UP AROUND 500 J/KG...WE WILL LIKELY CONTINUE TO SEE THE OCCASIONAL STORM PUT OUT HAIL THAT GETS UP IN THE 1 INCH TERRITORY OR SLIGHTLY LARGER. BEHIND THIS MORNING ACTIVITY...H7 TEMPS WILL PUSH UP TO BETWEEN 8 AND 10C...WITH A VERY DRY PLUME OF AIR COMING IN IN THE H7-H5 LEVEL AS WELL. THIS WILL LIKELY KEEP THE MPX AREA CAPPED AND DRY MUCH OF THE DAY AS WE WATCH THE WARM FRONT LIFT NORTH ACROSS IOWA. BY PEAK HEATING...THIS WARM FRONT LOOKS TO BE UP NEAR I-90. WARM SECTOR COMING UP WITH THIS FRONT IS THE SAME AIRMASS THAT HAS SPENT THE LAST THREE DAYS BREAKING RECORD HIGHS ACROSS TX/OK/KS...SO IT WILL BE WARM TO SAY THE LEAST...WITH HIGHS IN THE 90S LIKELY CLEAR UP TO THE I-80 CORRIDOR. THIS WARM FRONT STILL MAKES FOR A DIFFICULT FORECAST AS OVERCAST CONDITIONS TO THE NORTH OF THE FRONT WILL HOLD HIGHS BACK IN THE 50S/60S...WHILE SOUTH OF THE BOUNDARY IT WILL BE FEELING LIKE SUMMER. CONTINUED TO FAVOR THIS FORECAST TOWARD THE ECMWF...WHICH HAS MID 80S ALONG I-90 THAT FALL BACK TO THE UPPER 50S/LOWER 60S NORTH OF I-94. WE WILL HAVE TO WATCH THOSE TEMPS THOUGH. THERE IS VIRTUALLY NO CLOUD COVER ACROSS IOWA RIGHT NOW...AND IF THIS TREND CONTINUES OVER US THIS AFTERNOON...THEN SOMETHING MUCH CLOSER TO WHAT THE RAP HAS BEEN SHOWING ALL MORNING IS POSSIBLE...WHICH IS LOWER 90S COMING UP AS FAR NORTH AS MANKATO/REDWOOD FALLS...WITH HIGHS CLOSER TO 80 IN THE CITIES...WITH EVEN THE COLDER AREAS AROUND LADYSMITH PUSHING 70. MAIN QUESTION FOR THIS EVENING/TONIGHT IS WHEN DOES THE CAP BREAK. ONCE IT DOES...IT IS LOOKING LIKE A VERY ACTIVE NIGHT ACROSS THE MPX CWA. THROUGH THE AFTERNOON...ANY ACTIVITY LOOKS TO REMAIN TO THE NW OF THE CAP...WHICH WOULD KEEP THE BULK OF THE ACTIVITY TODAY OUT FROM CENTRAL SODAK INTO NW MN. EVENTUALLY...A STRENGTHENING LLJ AND THE APPROACH OF THE MAIN UPPER TROUGH WILL START TO ERODE THE CAP. GENERALLY FOLLOWED THE IDEA OF THE SPCWRF AND THE NMM/ARW WITH ACTIVITY TAKING OFF BETWEEN 2Z AND 4Z. GIVEN THE DEGREE OF INSTABILITY EXPECTED AND EFFECTIVE SHEARS UP AROUND 50 KTS...IT IS VERY LIKELY THAT THESE STORMS WILL BE ABLE TO PRODUCE LARGE HAIL...SO THE DAY1 SLIGHT RISK IS MORE THAN WARRANTED. ALTHOUGH NO CONVECTION IS CURRENTLY ANTICIPATED IN THE AFTERNOON...IF WE WERE TO SEE SOMETHING GO IT WOULD HAVE A HIGH LIKELIHOOD OF BEING SEVERE...WITH A TORNADO THREAT IF IT IS CLOSE TO THE WARM FRONT. HOWEVER...THE WARM/DRY LAYER NOTED EARLIER AROUND H7 WILL MOST LIKELY KEEP ANYTHING FROM GOING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 434 AM CDT WED MAY 7 2014 THE EXTENDED PERIOD WILL BE AN ACTIVE ONE WITH ONLY ONE DRY PERIOD FORECAST AND THAT IS FRIDAY NIGHT. THURSDAY IS THE DAY OF INTEREST. ALL INDICATIONS ARE FOR LOW PRESSURE OVER EASTERN NEBRASKA THURSDAY MORNING TO SLOWLY DEEPEN WHILE MOVING INTO SOUTHWEST MINNESOTA DURING THE AFTERNOON AND INTO CENTRAL MINNESOTA DURING THE EVENING. CONVECTION IS ANTICIPATED TO BE ONGOING THURSDAY MORNING ACROSS CENTRAL MN AND WEST CENTRAL WI. THIS WILL MOVE NORTHEAST EARLY ON ALLOWING FOR THE DESTABILIZATION TO COMMENCE. PROJECTIONS FOR THE AFTERNOON AND EVENING HOURS ARE FOR 0-1KM SHEAR TO BE IN THE 25-35 KNOT RANGE AHEAD OF THE LOW AND COLD FRONT WITH 0-6KM SHEAR IN THE 40-50 KNOT RANGE. EASTERN MN AND WESTERN WI ARE ALSO IN A FAVORABLE COUPLED JET ALOFT WITH 100 KNOT RIGHT ENTRANCE REGION OVER NORTHERN MN WHILE A 100+ KNOT JET SURGES INTO EASTERN IA DURING THE AFTERNOON. THE DIFFERENTIAL DIVERGENCE IS QUITE STRONG BY EVENING ACROSS THE TWIN CITIES. ALSO...VARIOUS SOLUTIONS ARE POINTING TO 0-3KM CAPE REACHING 100-150 J/KG BY LATE IN THE AFTERNOON...AGAIN CLOSE TO THE TWIN CITIES. HENCE...A SEVERE AFTERNOON AND EVENING IS LOOKING MORE AND MORE LIKELY WITH ALL FORMS OF SEVERE WEATHER POSSIBLE INCLUDING A FEW TORNADOES. THE SEVERE THREAT SHOULD BE OVER BY MIDNIGHT ACROSS WESTERN WI AS THE ATTENDANT COLD FRONT MOVES THROUGH. HIGHS ON THURSDAY HAVE POTENTIAL TO RUN INTO THE 80S FROM THE TWIN CITIES ON SOUTH AND SOUTHWEST. BLENDED GUIDANCE KEPT HIGHS IN THE UPPER 70S. A FEW SHOWERS MAY LINGER OVER NORTHERN AND EASTERN AREAS OF THE FA ON FRIDAY UNDER THE COLD UPPER TROUGH. AS MENTIONED EARLIER...FRIDAY NIGHT IS THE ONLY DRY PERIOD AS A WEAK RIDGE OF HIGH PRESSURE MOVES THROUGH. THE PATTERN STARTS TO BECOME MORE ACTIVE AGAIN ON SATURDAY AS NORTHERN AND SOUTHERN STREAM ENERGY BEGIN TO INFLUENCE THE WESTERN HALF OF THE CONUS. THIS DEVELOPS ANOTHER WAVE OF LOW PRESSURE TO OUR SOUTHWEST WITH SHOWER CHANCES INCREASING THROUGH THE WEEKEND AND EARLY NEXT WEEK. SOME SIGNIFICANT DIFFERENCES EXIST BETWEEN THE GFS AND EC BY EARLY NEXT WEEK ON THE LOCATION OF THE SURFACE LOW. THE GFS WOULD BE FLATTER AND FURTHER EAST WITH THE LOW WHILE THE EC IS MORE ROBUST WITH THE UPPER TROUGH AND SURFACE LOW. THIS WILL NEED TO BE WATCHED AS WE COULD BE CLOSE TO THE WARM SECTOR ALONG WITH A SEVERE WEATHER THREAT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1247 AM CDT WED MAY 7 2014 AT ABOUT 530Z...TSRA STARTED BUBBLING UP TO THE SOUTH OF FSD...RIGHT ABOUT WHEN/WHERE THE HRRR AND MPXWRF HAD THEM FORMING. FOLLOWED THOSE MODELS FOR TIMING WHAT SHOULD BE A LINE OF TSRA TO NEAR THE EAU AREA BETWEEN 12Z AND 14Z. THIS ACTIVITY LOOKS TO REMAIN SOUTH OF RWF/MSP...BUT LOOKS TO GET CLOSE ENOUGH TO WARRANT A CONTINUED MENTION OF A VCSH. ALSO NEEDED TO SLOW DOWN THE ARRIVAL OF ANY SHRA AS WELL AND ALSO SIGNIFICANTLY SLOWED DOWN THE ARRIVAL OF MVFR OR LOWER CIGS. FOLLOWED THE NAM/HRRR IDEA WITH CIGS REMAINING MORE AROUND 4K FT MUCH OF THE DAY UNTIL THE WARM FRONT GETS CLOSER TO EACH TERMINAL...WHICH IS WHEN A SIGNIFICANT DROP IN CIGS IS ANTICIPATED. WITH CIGS TO THE NORTH OF THE WARM FRONT ACROSS IA STILL UP BETWEEN 5K AND 7K FT...FOUND IT HARD TO BELIEVE THE GFSLAMP FOR HOW AGGRESSIVE IT IS WITH BRINGING IN THE LOWER CIGS. NOT EXPECTING ANY PRECIP ON WED...BUT FAVORED THE SPCWRF FOR HOW MORE WIDESPREAD TSRA ACTIVITY GOES DOWN AT THE END OF THE TAF PERIOD. KMSP...CONFIDENCE IS HIGH THAT TSRA TONIGHT/WED MORNING WILL REMAIN SOUTH OF THE FIELD...BUT MAY BE CLOSE ENOUGH TO IMPACT ANY DEPARTING/ARRIVING TRAFFIC. LESS CONFIDENCE IN CIG FORECAST AS THE APPROACH OF THE WARM FRONT COINCIDING WITH PEAK HEATING MAY MAKE IT TOUGH FOR MVFR CIGS TO DEVELOP EVEN AS EARLY AS 6Z TAF HAS IT. CONFIDENCE MUCH HIGHER IN TSRA IMPACTING THE FIELD WED NIGHT...THOUGH LESS CONFIDENCE ON TIMING. THE WARM FRONT LOOKS TO SURGE NORTH AFTER 00Z...WHICH SHOULD AID IN THE RAPID EXPANSION OF TSRA ACROSS MN. ONCE STORMS START...COULD BE A VERY LONG NIGHT FOR SEEING ACTIVITY IN THE AREA. /OUTLOOK FOR KMSP/ THU...VFR EARLY WITH IFR/TSRA LIKELY IN THE AFTERNOON. SOME STORMS MAY BE SEVERE. WINDS SE BECOMING S AT 10G20KTS. FRI...MVFR EARLY...THEN VFR. WINDS W AT 10G20KTS. SAT...VFR. WINDS S 5-10KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...RAH AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
105 AM CDT WED MAY 7 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 249 PM CDT TUE MAY 6 2014 A DEFUSE WARM FRONT WAS LOCATED OVER NORTHERN MISSOURI AND NORTHERN KANSAS AT 3 PM WHICH WILL ADVANCE SLOWLY NORTHWARD TO THE I-80 CORRIDOR BY EARLY WEDNESDAY MORNING. THIS WILL NOT DO MUCH TO GENERATE STORMS. INSTEAD...THE MAIN FORCING MECHANISM FOR STORM DEVELOPMENT TONIGHT WILL BE STRONG WAA AT 850 MB...KICKED OFF BY A STRENGTHENING LLJ THIS EVENING. AS THE INVERSION AT 850 CONTINUES TO INCREASE...ELEVATED INSTABILITY WILL GROW ABOVE THIS LEVEL...BUT CAPPING AT THIS LEVEL WILL ALSO MAKE IT MORE DIFFICULT TO GENERATE STORMS AWAY FROM THE FORCING OF THE JET. THE BEST POTENTIAL FOR STORMS WILL BE ACROSS SOUTHERN MINNESOTA AND PORTIONS OF SOUTHWEST AND WEST CENTRAL WISCONSIN...MAINLY SOUTH OF A LINE FROM HUDSON TO LADYSMITH. SYNOPTIC MODELS SEEM TO HAVE A GOOD HANDLE ON THIS IN TERMS OF QPF PLACEMENT...BUT THE MOST RECENT RUN OF THE HOPWRF /15Z/ SHOWS STORMS INITIATING FURTHER NORTH INCLUDING THE REDWOOD FALLS...TWIN CITIES...AND NEW RICHMOND AREAS AROUND MIDNIGHT. THUS...ENOUGH UNCERTAINTY STILL EXISTS TO PREVENT US FROM REDUCING POPS TOO MUCH ACROSS EASTERN MINNESOTA AND NORTHWESTERN WISCONSIN. LIKELY OR CATEGORICAL POPS ARE STILL IN PLACE TO THE SOUTH. BROAD ISENTROPIC LIFT ACROSS THE UPPER MIDWEST WILL BRING THE REST OF THE AREA A SLIGHT CHANCE OF STORMS...INCLUDING WESTERN AND CENTRAL MINNESOTA. MODEST AMOUNTS OF SHEAR WILL KEEP SEVERE WEATHER CHANCES MARGINAL...HOWEVER A SEVERE STORM OR TWO ARE CERTAINLY POSSIBLE FROM SOUTH CENTRAL MN TO WEST CENTRAL WI GIVEN STEEPENING MID LEVEL LAPSE RATES. WEDNESDAY WILL BE MOSTLY DRY. WITHOUT THE LLJ...NOT MUCH FORCING WILL EXIST TO OVERCOME SIGNIFICANT CAPPING BETWEEN 700-800 MB. BEST POTENTIAL FOR DEVELOPMENT WILL BE ACROSS WESTERN MN WHERE A SURFACE LOW LIFTING NORTH MAY ERODE SOME OF THE STRONG CAPPING. THIS LOW WILL ALSO DRAG THE WARM FRONT FROM IOWA NORTHWARD INTO FAR SOUTHERN MINNESOTA DURING THE AFTERNOON. MODELS ARE ALL OVER THE PLACE IN TERMS OF PLACEMENT...AND THIS WILL PLAY A BIG ROLE IN HOW WARM LOCATIONS GET. SOUTH OF THE FRONT...LOW TO MID 80S WILL BE EASILY ATTAINABLE WITH EVEN 90S ACROSS EASTERN NEBRASKA AND IOWA...BUT NORTH WILL BE SOCKED IN CONSIDERABLE CLOUDS AND AN EASTERLY FLOW KEEPING TEMPS IN THE UPPER 50S AND 60S. GEM SEEMS A BIT TOO FAR NORTH WITH THE FRONT REACHING CENTRAL MN...WHEREAS THE GFS DOES NOT SEEM AGGRESSIVE ENOUGH KEEPING IT ACROSS NORTHERN IOWA. SPLIT THE DIFFERENCE FOR THE GRIDS...WHICH MATCHES BEST WITH THE NAM AND ECMWF BRINGING 80S UP TO THE I-90 CORRIDOR. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 249 PM CDT TUE MAY 6 2014 A STRONG STORM SYSTEM IS STILL FORECAST TO IMPACT THE AREA WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. THERE REMAINS SOME MODEL DISAGREEMENTS IN TERMS OF OVERALL TRACK AND TIMING OF THE SFC LOW...AND THE STRENGTH OF A DRY SLOT TO AFFECT THE AREA. THEN THE LONGER RANGE MODELS SHOW ANOTHER POTENTIAL SYSTEM MOVING ACROSS THE AREA SAT NIGHT/SUN WITH HINTS AT ANOTHER STRONG STORM SYSTEM FOR THE BEGINNING OF NEXT WEEK. INTO WEDNESDAY NIGHT...THE STRENGTHENING LLJ WILL LEAD TO BETTER CHANCES FOR STORMS NORTH OF THE WARM FRONT. WE HAVE CONTINUED TO TREND POPS FROM AROUND 70% FOR CENTRAL MN TO JUST 30% DOWN TOWARD I-90. MID LEVEL FLOW IS FORECAST TO INTO TO NEAR 50 KTS/MUCAPE OVER 2000 J/KG AND MID LEVEL LAPSE RATES FROM 8-9C/KM...THERE WILL BE AMPLE OPPORTUNITY FOR THIS ACTIVITY TO BE SEVERE...WITH LARGE HAIL BEING THE MAIN THREAT GIVEN THE ELEVATED NATURE OF THE ACTIVITY NORTH OF THE WAR FRONT. FOR THURSDAY...THERE REMAINS SOME UNCERTAINTY WITH HOW THE EVENT WILL DEVELOP. PREVIOUS CONVECTION WILL HAVE SOME AFFECT ON OVERALL DEVELOPMENT EARLY IN THE PERIOD..AND HOW FAR NORTH THE WARM SECTOR WILL MOVE. THE GFS AND ECMWF HAVE COME INTO SOME AGREEMENT ON SLOWER MOVEMENT OF THE UPPER TROUGH AND THE MOVEMENT OF THE SURFACE LOW. THERE WILL LIKELY BE SOME SCATTERED CONVECTION OVER THE NORTHERN CWA EARLY THURSDAY. DEVELOPMENT WILL LIKELY INITIATE EARLY INTO THE SOUTHWEST...WITH LIKELY POPS AGAIN OVER MUCH OF THE AREA AFTER 15Z. CATEGORICAL POPS REMAIN OVER THE NORTH AND EAST PART OF THE CWA INTO THE AFTERNOON AS WELL...AS THE SURFACE LOW LIFTS NORTHEAST ACROSS THE CENTRAL CWA. THE GFS IS INDICATING SOME HIGH PROBABILITIES OF TORNADO DEVELOPMENT INTO CENTRAL AND EASTERN CWA INTO THE AFTERNOON. WE CERTAINLY HAVE ENOUGH INSTABILITY AND FORCING/110KT 30H JET MAX NOSING INTO EASTERN MN DURING THE AFTERNOON. THE 12Z ECMWF IS SLOWER WITH DEVELOPMENT INTO THE AFTERNOON BUT IT DEVELOPS EVEN A LARGER AREA OF HEAVY RAIN OVER THE CENTRAL AND EASTERN PORTIONS OF THE AREA. AT THE MOMENT...THE SLIGHT RISK FOR MUCH OF THE AREA IS WARRANTED....WITH HAIL AND STRONG WINDS A GOOD BET. CANT RULE OUT THE ISOLATED TORNADO HOWEVER. THE GFS AND ECMWF CONTINUE TO SHOW A WEAK WAVE LIFTING EAST OVER THE AREA SATURDAY NIGHT/SUNDAY TIME FRAME. THEN THEY DIVERGE HOWEVER ...WITH THE ECMWF MUCH SLOWER WITH THE WESTERN CONUS TROUGH...AND IT AFFECTS THIS REGION INTO EARLY NEXT WEEK. WILL HAVE TO HOLD ONTO SOME LOW CHANCE POPS DURING THIS PERIOD BECAUSE OF MODEL DISCREPANCIES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1247 AM CDT WED MAY 7 2014 AT ABOUT 530Z...TSRA STARTED BUBBLING UP TO THE SOUTH OF FSD...RIGHT ABOUT WHEN/WHERE THE HRRR AND MPXWRF HAD THEM FORMING. FOLLOWED THOSE MODELS FOR TIMING WHAT SHOULD BE A LINE OF TSRA TO NEAR THE EAU AREA BETWEEN 12Z AND 14Z. THIS ACTIVITY LOOKS TO REMAIN SOUTH OF RWF/MSP...BUT LOOKS TO GET CLOSE ENOUGH TO WARRANT A CONTINUED MENTION OF A VCSH. ALSO NEEDED TO SLOW DOWN THE ARRIVAL OF ANY SHRA AS WELL AND ALSO SIGNIFICANTLY SLOWED DOWN THE ARRIVAL OF MVFR OR LOWER CIGS. FOLLOWED THE NAM/HRRR IDEA WITH CIGS REMAINING MORE AROUND 4K FT MUCH OF THE DAY UNTIL THE WARM FRONT GETS CLOSER TO EACH TERMINAL...WHICH IS WHEN A SIGNIFICANT DROP IN CIGS IS ANTICIPATED. WITH CIGS TO THE NORTH OF THE WARM FRONT ACROSS IA STILL UP BETWEEN 5K AND 7K FT...FOUND IT HARD TO BELIEVE THE GFSLAMP FOR HOW AGGRESSIVE IT IS WITH BRINGING IN THE LOWER CIGS. NOT EXPECTING ANY PRECIP ON WED...BUT FAVORED THE SPCWRF FOR HOW MORE WIDESPREAD TSRA ACTIVITY GOES DOWN AT THE END OF THE TAF PERIOD. KMSP...CONFIDENCE IS HIGH THAT TSRA TONIGHT/WED MORNING WILL REMAIN SOUTH OF THE FIELD...BUT MAY BE CLOSE ENOUGH TO IMPACT ANY DEPARTING/ARRIVING TRAFFIC. LESS CONFIDENCE IN CIG FORECAST AS THE APPROACH OF THE WARM FRONT COINCIDING WITH PEAK HEATING MAY MAKE IT TOUGH FOR MVFR CIGS TO DEVELOP EVEN AS EARLY AS 6Z TAF HAS IT. CONFIDENCE MUCH HIGHER IN TSRA IMPACTING THE FIELD WED NIGHT...THOUGH LESS CONFIDENCE ON TIMING. THE WARM FRONT LOOKS TO SURGE NORTH AFTER 00Z...WHICH SHOULD AID IN THE RAPID EXPANSION OF TSRA ACROSS MN. ONCE STORMS START...COULD BE A VERY LONG NIGHT FOR SEEING ACTIVITY IN THE AREA. /OUTLOOK FOR KMSP/ THU...VFR EARLY WITH IFR/TSRA LIKELY IN THE AFTERNOON. SOME STORMS MAY BE SEVERE. WINDS SE BECOMING S AT 10G20KTS. FRI...MVFR EARLY...THEN VFR. WINDS W AT 10G20KTS. SAT...VFR. WINDS S 5-10KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...BORGHOFF LONG TERM...DWE AVIATION...MPG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
335 AM CDT WED MAY 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM CDT WED MAY 7 2014 ISOLATED ELEVATED STRONG TO SEVERE THUNDERSTORMS ARE ONGOING THIS MORNING. THE HRRR AND RAP REALLY ARE NOT HANDLING THE STORM TRACK AS THESE METEOROLOGICAL CHALLENGED MODELS PREFER TO TRACK THE ACTIVITY MORE NORTHEAST THROUGH NORTHWEST NEB VS THE WRN SANDHILLS. THIS LIKELY A RESULT OF THE STORM(S) BECOMING ROOTED IN THE LOW LEVEL EASTERLIES. AT ANY RATE THE CURRENT THINKING IS THE STORMS WILL EITHER WEAKEN BEFORE 12Z OR CONTINUE TRACKING TOWARD SCNTL SD. A BLEND OF THE NAM...RAP...ECM...SREF AND THE PREVIOUS FORECAST SUGGESTED SCATTERED POPS THIS MORNING BECOMING LIKELY THIS AFTERNOON. THE RAP HAS ANALYZED A CLOSED H700MB LOW OVER NORTHEAST COLO AT 07Z WHICH LIFTS NORTHEAST THROUGH NWRN NEB THIS MORNING TO FOLLOWED BY A SECOND AND THIRD H7 WAVES THIS AFTERNOON AND EARLY THIS EVENING. THIS WOULD LIKELY KEEP THE WARM SECTOR FROM KIML TO KONL AND SOUTH DRY TODAY. THE NAM SUGGESTS SOME CONVECTION COULD DEVELOP OFF THE FRONT RANGE THIS AFTN AND SWEEP NORTHEAST THROUGH THE SRN AND NERN ZONES. THE THREAT OF SEVERE WEATHER IS OBVIOUS WITH BULK SHEAR 50 KTS OR GREATER AND STEEPENING LAPSE RATES WITH THE APPROACHING 4 CORNERS LOW. SPC HATCHED AN EGG OF VERY LARGE HAIL ACROSS THE WRN SANDHILLS AND PANHANDLE. THIS IS ALONG AND NORTH OF SFC FRONT WHICH IS EXPECTED TO LIFT THROUGH SRN AND NERN NEB LATE THIS AFTN. VERY LARGE HAIL IS POSSIBLE WITH STORMS THIS AFTERNOON AND EVENING AND MOST IF NOT ALL OF THIS SHOULD BE IN THE COLD AIR NORTH OF THE SFC FRONT. THE 5 PERCENT TORNADO AND 15 PERCENT WIND PROBABILITIES WOULD APPEAR CONDITIONALLY TIED TO STORMS FORMING ALONG THE SFC FRONT WHICH LIFTS NORTH OF I-80 AROUND 21Z THIS AFTN AND THEN DROPS BACK SOUTH. SEVERE WEATHER CONTINUES THIS EVENING...PRESUMABLY ELEVATED...WITH THE APPROACH OF THE MAIN UPPER LEVEL LOW. THE NAM AND OTHER MODELS LIFT A DECENT SHOT OF PV15 THROUGH THE FCST AREA. MEANWHILE...LATE SEASON ARCTIC AIR...CURRENTLY IN MONTANA DROPS THROUGH THE HIGH PLAINS FOR A ZONE OF THUNDERSTORMS CHANGING TO WET HEAVY SNOW. THE NAM BACKS THE ELEVATED INSTABILITY RIGHT UP AGAINST THE RAIN SNOW LINE ACROSS SHERIDAN COUNTY AROUND 09Z. THIS MIGHT BE TOO SLOW GIVEN THE PROXIMITY OF THE COLD AIR ACROSS MT AND THE RAIN SNOW LINE OVER NERN WY. THE RAP CAN FIGURE THIS OUT LATER TODAY. FOR NOW THE RAP HAS THE H700MB FREEZING LINE MOVING THROUGH SERN WY AT 00Z THIS EVENING SO A QUICKER CHANGE TO SNOW IS POSSIBLE. THE BEST GUESS ON SNOW AMOUNTS USES THE NAM...GEMREG...SREF AND ECM FOR QPF WITH A 5 OT 1 RATIO FOR UP TO 4 INCHES IN NORTHERN SHERIDAN COUNTY THROUGH 12Z THURSDAY MORING. LOCALLY HIGHER AMOUNTS COULD DEVELOP ESPECIALLY IF THE CHANGE OVER OCCURS AT 06Z VS THE NAM MODEL SHOWING 09Z. THE RAP HAS BEEN THE BEST PERFORMER THIS SPRING IN RAIN SNOW EVENTS FOLLOWED THE NAM. A WINTER WEATHER ADVISORY IS IN PLACE FOR SHERIDAN COUNTY 09Z-15Z TONIGHT THROUGH THURSDAY MORNING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 335 AM CDT WED MAY 7 2014 LARGE UPPER LEVEL TROUGH WILL CONTINUE TO SHIFT EAST NORTHEAST ACROSS THE CENTRAL PLAINS ON THURSDAY...REACHING THE NORTHERN MISSOURI VALLEY EARLY FRIDAY. IN THE WAKE OF THE UPPER TROUGH ...QUASI-ZONAL FLOW WILL PREVAIL THROUGH MUCH OF THE WEEKEND...BUT EVENTUALLY BREAK DOWN WITH THE APPROACH OF THE NEXT APPRECIABLE WESTERN STATES UPPER TROUGH. THE SURFACE PATTERN FAVORS A NORTHEASTWARD ADVANCING LOW TOWARD MINNESOTA AND FINALLY INTO SOUTHWEST ONTARIO BY EARLY FRIDAY. THIS LOW WILL DRAG A FRONT THROUGH THE CWA LEAVING POST FRONTAL CONDITIONS INTO EARLY FRIDAY...BUT THE LOWER TROPOSPHERIC FLOW WILL RETURN TO SOUTHERLY AS A LEE TROUGH DEVELOPS OFF THE HIGH PLAINS FRIDAY WITH THE APPROACH OF A WEAK NORTHERN PLAINS UPPER WAVE. THIS WAVE...AS IT/S PREDECESSOR...WILL DRAG AN ADDITIONAL FRONT THROUGH THE CWA ON SATURDAY. THE SATURDAY BAROCLINIC ZONE IS FORECAST TO BE WEAK...WITH LITTLE TO NO SENSIBLE CHANGES ANTICIPATED. FOR THURSDAY...WINTER WEATHER ADVISORY ACROSS SHERIDAN COUNTY WILL CONTINUE UNTIL 15Z. ALL THE MEDIUM RANGE DETERMINISTIC MODELS HAVE CONVERGED SOMEWHAT ON A SOLUTION FOR WHICH THERMAL PROFILES WOULD SUPPORT SNOW ACROSS SHERIDAN COUNTY. THERMAL PROFILES INDICATE A DEEP SATURATION...AT TIMES EXTENDING INTO THE DGZ...BUT WARM GROUND TEMPERATURES AND SFC T/S NEAR OR SLIGHTLY ABOVE 0C CREATE LOW CONFIDENCE FORECAST CONCERNING ACCUMULATIONS. SINCE A STRONG DEFORMATION ZONE IS SHOWN TO SET UP IN THIS AREA...CO-LOCATED IN THE TROWAL REGION OF THE SYSTEM...SNOW RATES MAY BE SUFFICIENT TO OVERCOME THE HIGH SUN ANGLE AND WARM TEMPERATURES...BUT CONFIDENCE IS NOT ENOUGH TO EXPIRE THE ADVISORY BEFORE 15Z. CONSEQUENTLY...GIVEN THE STRENGTH OF THE DEFORMATION...SNOW RATES MAY BE SUFFICIENT TO ALLOW FOR SLUSH ACCUMULATION PAST 15Z THURSDAY. FORECAST TIMING WITH THE CURRENT WINTER WEATHER ADVISORY MAY CHANGE WITH NEAR TERM GUIDANCE. WITH LOW LEVEL CAA ONGOING...HIGH TEMPERATURES THURSDAY WILL BE CHILLY...40S FOR THE NORTHWEST...POSSIBLY SOME 60S SOUTHEAST. WILL NEED TO MONITOR CLOUDS THURSDAY NIGHT AND FRIDAY MORNING AS ANY CLEARING WOULD LEAD TO SUB 0C LOWS...WITH THE THREAT OF A LIGHT FREEZE. ATTM...FAVORING THE ECMWF SOLUTION WHICH IS ON SLOWER SIDE...KEEPING SUFFICIENT CLOUDS ACROSS MUCH OF THE FORECAST AREA TO PREVENT A WIDESPREAD FREEZE. ATTM...NORTHWEST NEBRASKA WOULD HAVE THE HIGHEST POTENTIAL OF SEEING A DAMAGING FREEZE /TO YOUNG PLANTS/...ESPECIALLY IF SNOW TOTALS ARE HIGHER THAN CURRENTLY ANTICIPATED. THE ENTIRE NORTH PLATTE CWA HAS NOT REACHED THE 50 PERCENTILE FOR LAST FREEZE DATE...WE DO NOT PLAN TO FROST/FREEZE HEADLINES ATTM. FRIDAY...WITH RETURN FLOW DIRECTING WAA BACK INTO THE CWA...TEMPERATURES SHOULD WARM BACK WELL INTO THE 60S...POSSIBLY LOWER 70S FOR THE ENTIRE CWA. BUT A FAST MOVING WAVE PASSING THROUGH THE QUASI-ZONAL FLOW MAY SPARK OFF A SHOWER OR TWO DURING THE EVENING AND EARLY ON SATURDAY...WITH A WEAK WIND SHIFT TO FOLLOW. AGAIN SATURDAY TEMPERATURES WON/T BE TOO FAR OFF FROM CLIMO...GENERALLY HIGHS IN THE 60S TO LOWER 70S CAN BE EXPECTED FOR MOST IF NOT ALL LOCATIONS. LATE WEEKEND INTO EARLY NEXT WEEK...ANOTHER SYSTEM LOOKS TO MOVE INTO THE CENTRAL ROCKIES SATURDAY NIGHT AND EMERGE ONTO THE PLAINS SUNDAY AND MONDAY. WIDESPREAD PRECIPITATION WILL BE POSSIBLE...AND DESPITE DIFFERENCES WITH THE HANDLING OF THE SYSTEM...WILL MAINTAIN 30-40 POPS LATE WEEKEND INTO EARLY NEXT WEEK FOR MUCH OF THE CWA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1224 AM CDT WED MAY 7 2014 ISOLATED THUNDERSTORMS WILL DISSIPATE IN THE OVERNIGHT HOURS ACROSS THE EASTERN NEBRASKA PANHANDLE AND NORTHWESTERN SANDHILLS. ATTM THIS ACTIVITY WILL REMAIN WEST OF THE KLBF AND KVTN TERMINALS. SKIES WILL BE MOSTLY CLOUDY OVERNIGHT WITH CIGS RANGING FROM 15000 TO 20000 FT AGL. AT THE KLBF TERMINAL...SOME LOW CLOUDS MAY DEVELOP OVERNIGHT TONIGHT AS LOW LEVEL MOISTURE PUSHES INTO SOUTHERN AND CENTRAL NEBRASKA FROM THE EAST. CIGS MAY DROP TO AROUND 1000 FT AGL AT THE KLBF TERMINAL AROUND 12Z WEDNESDAY. CIGS WILL LIFT BY LATE MORNING WITH MOSTLY HIGH CLOUDS EXPECTED INTO THE AFTERNOON AND EVENING HOURS. BY 22Z WEDNESDAY...THE THREAT FOR THUNDERSTORMS WILL INCREASE ACROSS SOUTHWESTERN NEBRASKA AND CONTINUE THROUGH LATE EVENING WEDNESDAY. AT THIS TIME...THE THREAT WILL BE FAIRLY LOW AND WILL BE HANDLED WITH A PROB 30 GROUP. FOR THE KVTN TERMINAL...BROKEN CIGS AROUND 15000 FT AGL WILL LOWER TO AROUND 4000 FT AGL BY MID MORNING WEDNESDAY AND PERSIST THROUGH 06Z THURSDAY. THE THREAT FOR THUNDERSTORMS WILL INCREASE AFTER 00Z THURSDAY. WITH SCATTERED COVERAGE EXPECTED AND SOME DOUBT AS TO WHEN THUNDERSTORMS WILL OCCUR...WILL HANDLE THE MENTION WITH A PROB 30 GROUP. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 3 AM TO 9 AM MDT THURSDAY FOR NEZ004. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1137 PM CDT TUE MAY 6 2014 .SHORT TERM...(TONIGHT THROUGH FRIDAY) ISSUED AT 305 PM CDT TUE MAY 6 2014 THE MAIN FORECAST CONCERNS IN THE SHORT TERM ARE SMALL PRECIP CHANCES TONIGHT...FIRE WEATHER CONCERNS AND HOW WARM TEMPERATURES WILL GET WEDNESDAY...THEN RAIN CHANCES WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. FIRE WEATHER FORECAST CONCERNS ARE ADDRESSED BELOW. THIS MORNING/S UPPER AIR MAPS SHOWED A MID TROPOSPHERIC TROF OVER THE WEST COAST WITH A RIDGE OVER THE SOUTHEAST U.S. SOUTHWEST FLOW ALOFT WAS TRANSPORTING SOME MID LEVEL MOISTURE INTO THE REGION. WARM...+12C H7 TEMPERATURES WERE NOTED OVER KANSAS. AT H85...THERE WAS SOME POOLING OF HIGHER DEWPOINTS AT OAX...HOWEVER IT WAS FAIRLY DRY AT H85 ACROSS THE PLAINS. THE SURFACE MAP AT 20Z...CONTINUED TO SHOW EAST AND SOUTHEAST FLOW WITH TEMPERATURES IN THE 70S...HOWEVER...THE MID 80 HAD MADE IT INTO FALLS CITY. BASED ON THE SURFACE WINDS AND TEMPERATURES...IT APPEARS THE WARM FRONT HAD LIFTED INTO SOUTHEAST NEBRASKA AND SHOULD BE AROUND LINCOLN. TONIGHT AND WEDNESDAY...THE SURFACE FRONT WILL LIFT NORTH INTO NORTHEAST NEBRASKA AS SURFACE LOW PRESSURE FORMS IN NORTHEAST COLORADO. THE LOW LEVEL JET WILL STRENGTHEN ACROSS EASTERN KANSAS INTO SOUTHEAST NEBRASKA AND THERE IS SOME BROAD SYNOPTIC LIFT ALONG WITH STEEP LAPSE RATES AND WEAK FRONTOGENESIS ALONG WITH SOME WEAK HEIGHT FALLS. THE TRAJECTORY FOR THE BEST PLACEMENT OF PRECIPITATION IS MORE TOWARD CENTRAL IOWA INTO MINNESOTA...HOWEVER SOMETHING ISOLATED MAY TRY TO DEVELOP IN OUR FORECAST AREA...ALONG AND NORTH OF THE WARM FRONT. DEEP MOISTURE APPEARS TO BE A LIMITING FACTOR AND MOST OF THE OPERATIONAL MODELS KEEP THE PRECIP CHANCES ON THE FRINGES OF OUR FORECAST AREA OR OUT OF THE AREA. FORECAST SOUNDINGS SHOW THAT IF SOMETHING HIGH BASED DOES DEVELOP...THERE WOULD BE THE POTENTIAL FOR SOME GUSTY WINDS WITH ANY ISOLATED STORMS. FOR NOW...FAR NORTHEAST NEBRASKA AND WESTERN IOWA IS WHERE OUR ISOLATED THUNDERSTORM CHANCES ARE MENTIONED. THE LATEST RAP IS HINTING AT SOMETHING IN SOUTHEAST NEBRASKA THIS EVENING...SO THIS WILL NEED TO BE WATCHED. WEDNESDAY AFTERNOON...THE VERY DRY AIR OVER PARTS OF SOUTHWEST KANSAS ARE FORECAST TO BE DRAWN NORTHEASTWARD AHEAD OF THE FRONT. THIS COMBINED WITH FAVORABLE MIXING AND SOUTHWEST WINDS SHOULD RESULT IN HOTTER TEMPERATURES IN THE 80S TO LOWER 90S...RESULTING VERY HIGH TO EXTREME FIRE DANGER CONDITIONS. IT DOES NOT LOOK LIKE RECORDS 95/96/99 OMAHA/LINCOLN/NORFOLK... BUT COULD GET CLOSE IF FULL HEATING IS REALIZED. AS DISCUSSED BELOW...DUE TO THE GREENESS...THE RFW WAS LIMITED TO THE AREA THAT HAS BEEN THE DRIEST. WEDNESDAY NIGHT INTO THURSDAY NIGHT...THE MID LEVEL TROF CONTINUE TO MOVE INTO THE PLAINS WITH MOISTURE RICH AIR RETURNING TO EASTERN KANSAS AND A NARROW AREA MAKING IT INTO EASTERN NEBRASKA AND WESTERN IOWA. DO HAVE SCATTERED SHOWERS AND THUNDERSTORMS MENTIONED. THERE IS A SEVERE POTENTIAL WITH THESE STORMS DUE TO THE MODERATE INSTABILITY AND FAVORABLE SHEAR PROFILES. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 305 PM CDT TUE MAY 6 2014 THERE ARE STILL SOME LARGE MODEL DIFFERENCES. STILL LOOKS LIKE A CHANCE FOR THUNDERSTORMS SATURDAY AND SATURDAY NIGHT. LARGER DIFFERENCES FOR THE REST OF THE WEEKEND INTO EARLY NEXT WEEK. TEMPERATURES STILL LOOK TO MOSTLY BE IN THE 60S AND 70S. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1134 PM CDT TUE MAY 6 2014 VFR CONDITIONS ARE EXPECTED THROUGH THE TAF CYCLE. ADVERTISED LOW LEVEL MOISTURE HAS NOT PRODUCED AN MVFR CLOUD DECK SO HAVE REMOVED ANY MENTION IN TAFS. SOME HAZY CONDITIONS CANNOT BE COMPLETELY RULED OUT IN THE MORNING...HOWEVER CONFIDENCE IN THIS IS FAIRLY LOW SO WILL NOT MENTION IN THE TAFS. A WARM FRONT IN THE AREA WILL CONTINUE TO SLOWLY DRIFT NORTH. SOUTHWEST SFC WINDS WILL INCREASE AT KLNK AND KOMA WED AFTERNOON HOWEVER MAY REMAIN FAIRLY LIGHT OUT OF THE SOUTHEAST AT KOFK. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...RED FLAG WARNING FROM NOON TO 8 PM CDT WEDNESDAY FOR NEZ051-065- 066-078-088-089. IA...NONE. && $$ SHORT TERM...ZAPOTOCNY LONG TERM...ZAPOTOCNY AVIATION...KERN
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1143 PM MDT TUE MAY 6 2014 .AVIATION... 06Z TAF CYCLE WINDS HAVE DIMINISHED ACROSS NORTHERN AND CENTRAL NEW MEXICO THIS EVENING...BUT ARE EXPECTED TO STRENGTHEN AGAIN LATE WEDNESDAY MORNING...REMAINING GUSTY THROUGH EARLY TOMORROW EVENING. SOME SMOKE MAY BE VISIBLE NEAR AND DOWNWIND OR EAST NORTHEAST OF THE JEMEZ MOUNTAINS WHERE PRESCRIBED BURNS HAVE BEEN ONGOING...BUT NO PERCEIVABLE VISIBILITY REDUCTIONS ARE EXPECTED. WINDS WILL BE STRONGEST IN CENTRAL TO EASTERN NEW MEXICO WEDNESDAY AFTERNOON WHERE OCCASIONAL GUSTS WILL APPROACH 40 TO 45 KT. 52 && .PREV DISCUSSION...745 PM MDT TUE MAY 6 2014... .UPDATE... UPDATED FORECAST TO ISSUE A WIND ADVISORY FOR WEDNESDAY FOR MUCH OF CENTRAL...SOUTH CENTRAL AND EASTERN NEW MEXICO. ALSO UPGRADED THE FIRE WEATHER WATCH FOR THE MIDDLE RIO GRANDE VALLEY. TIMING OF THE COLD FRONT WEDNESDAY AROUND MAX HEATING HERE IN THE MIDDLE RIO GRANDE VALLEY LENDING MORE CONFIDENCE TO SEEING AT LEAST A COUPLE HOURS OF WIND ADVISORY SPEEDS...WITH BLOWING DUST LOOKING MORE LIKELY AS WELL. THE WIND ADVISORY EXPIRES AT 8 PM MDT WEDNESDAY... BUT MAY NEED TO BE EXTENDED FOR SOME OF THE EAST CENTRAL AND NORTHEAST PLAINS GIVEN THE TIMING OF THE CORE OF STRONGER WINDS ALOFT AS THE UPPER TROUGH PULLS NE ACROSS NW NEW MEXICO AND INTO COLORADO. 11 && .PREV DISCUSSION...246 PM MDT TUE MAY 6 2014... .SYNOPSIS... THE NEXT STORM SYSTEM APPROACHING NEW MEXICO FROM THE WEST WILL DELIVER ANOTHER PUNCH OF SPRING WINDS AND BLOWING DUST WEDNESDAY. WIDESPREAD DANGEROUS FIRE WEATHER CONDITIONS WILL ACCOMPANY THE WIND AS CONDITIONS ARE EXTREMELY DRY OVER THE AREA. THE WELL ABOVE NORMAL HIGH TEMPERATURES OVER THE PAST SEVERAL DAYS WILL COOL BACK TO BELOW NORMAL FOR THE WEST WEDNESDAY...THEN ALL AREAS THURSDAY AND FRIDAY. A FEW LOCATIONS ACROSS THE NORTHERN AND WESTERN HIGH TERRAIN ALSO HAVE THE POTENTIAL FOR A COUPLE SHOWERS AND THUNDERSTORMS BOTH DAYS. TEMPERATURES WILL REBOUND AGAIN BACK NEAR TO SLIGHTLY ABOVE NORMAL FOR THE WEEKEND WITH WIDESPREAD BREEZY CONDITIONS EXPECTED. && .DISCUSSION... MSAS ANALYSIS SHOWED SURFACE LOW PRESSURE DEEPENED TO 994MB AT 19Z OVER SE COLORADO AND THE 19Z RAP INDICATES THIS WILL CONTINUE TO 989MB BY 00Z. MEANWHILE UPPER LEVEL WINDS ARE INCREASING OVER THE REGION AHEAD OF AN APPROACHING H5 UPPER LOW OVER EAST CENTRAL NV. SURFACE OBS AT KLVS HAVE BEEN NEAR OR JUST ABOVE WIND ADVISORY A COUPLE TIMES BUT SINCE ISOLD IN NATURE WILL NOT ISSUE HIGHLIGHTS. MORE SIGNIFICANT WINDS WILL ARRIVE WEDNESDAY AS THE CORE OF A 40-50KT 700-500MB JET SLIDES OVER CENTRAL/EASTERN NM. WILL PASS ALONG WIND ADVISORY HIGHLIGHTS TO OVERNIGHT CREW. ON THE QPF SIDE OF THINGS THERE ISNT MUCH TO GET EXCITED ABOUT. WPC PROBABILISTIC QPF VALUES FOR 0.10 OR MORE DO SHOW VALUES AROUND 30 PCT OVER SW FACING SLOPES OF THE NW MTS WEDNESDAY. GFS/NAM LIFTED INDICES ARE NEAR -2C FOR TMRW AFTERNOON SO THUNDER POTENTIAL STILL EXISTS. RAISED POPS INTO THE 40 AND 50 PCT RANGE BUT AMOUNTS WILL BE VERY LIGHT. ALSO TOSSED IN DUST FOR THE NW PLATEAU. MAX TEMPS WILL TREND COLDER OVER THE WEST THEN 5 TO 15F BLW NORMAL FOR ALL AREAS THURSDAY. IT WILL FEEL QUITE COOL THURSDAY WITH WIDESPREAD BREEZY CONDITIONS AND ANOTHER ROUND OF SHOWERS/ISOLD STORMS NEAR AND EAST OF HIGH TERRAIN. AGAIN QPF WILL BE VERY LIGHT. FLOW WILL RELAX SLIGHTLY AND BECOME MORE ZONAL WITH WARM ADVECTION THRU THE WEEKEND. GENERALLY CLEAR SKIES ARE EXPECTED MOST AREAS WITH THE EXCEPTION OF HIGH CLOUDS OVER THE NORTH. 700MB TEMPS WILL WARM TO NEAR +12C WHICH IS NEAR THE 75 PERCENTILE FOR MID MAY. THAT WILL TRANSLATE TO HIGHS 5 TO 15F ABV NORMAL AGAIN. MODEL CONSISTENCY AND OUTLOOK FOR NEXT WEEK IS ALMOST COMICAL SO WILL LEAVE THAT FOR LATER. GUYER && .FIRE WEATHER... WIDESPREAD RED FLAG CONDITIONS WILL CONTINUE THROUGH MID EVENING. HAVE UPGRADED ZONES 103 AND 107 TO A RED FLAG WARNING FOR WEDNESDAY LATE MORNING TO EARLY EVENING. WILL LEAVE ZONE 106 AS A WATCH AND LET THE STELLAR NIGHT CREW TAKE ONE MORE LOOK. CHANGE IN THE WEATHER IS ON THE WAY WITH COOLER TEMPERATURES AND EVENTUALLY LESS WIND...THANKS TO A POTENT COLD FRONT TOMORROW AND UPPER LEVEL DISTURBANCE. ONLY MODEST PRECIPITATION CHANCES ACROSS THE NORTH IN THE WEDNESDAY THROUGH THURSDAY TIME PERIOD. WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS TO CONTINUE THROUGH MID EVENING FOR MUCH OF NORTHERN AND CENTRAL NEW MEXICO. WINDS TO SUBSIDE DURING THE NIGHT ASIDE FROM MODERATE BREEZES OVER THE MOUNTAINS AND EAST SLOPES. WINDS WILL INCREASE QUICKLY WEDNESDAY AND BE THE STRONGEST WINDS OF THE WEEK. CRITICAL FIRE WEATHER WILL BE EASILY REACHED OVER MOST CENTRAL AND ALL EASTERN AREAS. HIGH TEMPERATURES WILL BE LOWER EVERYWHERE...BUT STILL ABOVE NORMAL IN THE FAR EAST. THIS WILL BE THE AREA WITH THE LOWEST RH VALUES WITH SINGLE DIGIT READINGS FOR ABOUT 10 HOURS. HAINES VALUES TO BE HIGH TO MODERATE. AREAS TO THE WEST ARE MORE IN THE GREY AREA AS TO HOW TO TREAT THE CRITICAL FIRE WEATHER CONDITIONS. WHILE WINDS WILL BE VERY STRONG AND HUMIDITIES BELOW 15 PERCENT FOR MANY HOURS...THE TEMPERATURES WILL BE NEAR TO BELOW NORMAL IN ZONES 103 AND 107. WITH HAINES VALUES STILL PARTLY IN THE HIGH CATEGORY IN ZONES 103 AND 10 WILL GO AHEAD AND UPGRADE THESE ZONES TO A RED FLAG WARNING FOR WEDNESDAY. WILL LEAVE ZONE 106...MIDDLE RIO GRANDE VALLEY...AS A WATCH. CERTAINLY WINDS AND HUMIDITIES WILL BE CRITICAL FOR SEVERAL HOURS...BUT LOW TO MODERATE HAINES VALUES AND HIGHS SEVERAL DEGREES BELOW NORMAL BRING A MIXED SIGNAL AS TO JUST HOW CRITICAL THIS AREA WILL BE. AS MENTIONED ABOVE WILL LET NIGHT CREW MAKE THE CALL ON ZONE 106. WILL NEED TO FACTOR IN HOW INCREDIBLY DRY IT HAS BEEN LATELY AS WELL. AS FOR CHANCE OF PRECIPITATION...ONLY THE NORTHWEST AND NORTH CENTRAL HIGHER TERRAIN COULD SEE A SHOWER OR THUNDERSTORM WEDNESDAY. MUCH COOLER AIR WILL CONTINUE TO POUR INTO THE STATE WEDNESDAY NIGHT AND THURSDAY. WINDS WILL ALSO FINALLY DIMINISH FOR MOST AREAS. IT WILL STILL BE BREEZY ACROSS THE EAST CENTRAL AREAS. A FEW RAIN AND MOUNTAIN SNOW SHOWERS WILL BE POSSIBLE ACROSS THE WEST AND NORTH BUT NO WETTING PRECIPITATION. FRIDAY SHOULD BE DRY AND MILDER WITH NEAR NORMAL TEMPERATURES AND NOT MUCH WIND. THE WEEKEND SHOULD BE MOSTLY DRY WITH THE WARMING TREND CONTINUING SATURDAY AND LEVELING OFF ON SUNDAY. AN APPROACHING BACK DOOR COLD FRONT COULD TRIGGER A SHOWER IN THE NORTHEAST AND OVER THE NORTHERN MOUNTAINS LATE SUNDAY. THE START OF NEXT WEEK WILL BE COOLER IN THE EAST. IT WILL BE DRY ASIDE FROM A NORTHERN MOUNTAIN SHOWER. THE EUROPEAN MODEL IS MORE BULLISH WITH A TROUGH AND THE PRECIPITATION POTENTIAL FOR EARLY NEXT WEEK. THEN THE GFS GOES BONKERS WITH A STRONG BACK DOOR COLD FRONT BY THE MIDDLE OF NEXT WEEK AND SIGNIFICANT PRECIPITATION IN THE EAST BEHIND THE FRONT. JUST WISHFUL THINKING AT THIS POINT. CHJ && .AVIATION... 18Z TAF CYCLE STORM OVER THE GREAT BASIN TO HEAD SLOWLY EAST. NEAR SFC WINDS STRONGER TODAY THAN MONDAY. SW WIND GUSTS OF 28-30 KTS AT FMN...ABQ...AEG AND SAF. SW WIND GUSTS OF 35-37 KTS OTHER TAF SITES. NO RESTRICTIONS TO VSBY DUE TO DUST IN ANY TAF FORECAST BUT COULD BE SOME MODEST RESTRICTIONS ARE NOT ENTIRELY OUT OF THE QUESTION...MAINLY FOR LVS...TCC AND ROW. OTHERWISE...VFR CONDITIONS ARE FORECAST TO PERSIST. STRONG WINDS AGAIN WED OVER THE E...LOWER SPEEDS IN THE WEST. 40 && .ABQ WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 10 AM TO 8 PM MDT WEDNESDAY FOR THE FOLLOWING ZONES...NMZ103-104-106>108. WIND ADVISORY FROM NOON TO 8 PM MDT WEDNESDAY FOR THE FOLLOWING ZONES...NMZ515-519>540. && $$
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1150 PM CDT TUE MAY 6 2014 .UPDATE... ISSUED AT 1150 PM CDT TUE MAY 6 2014 LOCAL/REGIONAL RADARS SHOWING AN AREA OF RAIN SHOWERS IN WESTERN SOUTH DAKOTA HEADING NORTHEAST WITH TIME. THE HRRR MODEL CAPTURES THIS AREA THE BEST AND SHIFTS IT INTO SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA OVERNIGHT INTO MID MORNING WEDNESDAY. HAVE USED THIS FOR THE POPS/PRECIPITATION FORECAST. STILL APPEARS THAT THE WEST WILL REMAIN UNDER THE HIGHEST POPS FOR THE REST OF TUESDAY NIGHT AND A PORTION OF WEDNESDAY...BEFORE THE MAIN SURGE OF SHOWERS SHIFTS INTO CENTRAL NORTH DAKOTA WEDNESDAY NIGHT IN TANDEM WITH APPROACH OF A MID LEVEL CLOSED CIRCULATION. CURRENT FORECAST HAS THE NEAR TERM HANDLED WELL AND ONLY MINOR TWEAKS TO CURRENT POPS/WEATHER. UPDATE ISSUED AT 950 PM CDT TUE MAY 6 2014 LATEST RADAR IMAGERY SHOWS ISOLATED SHOWERS LIFTING NORTHEAST ACROSS CENTRAL NORTH DAKOTA. MAIN SHOWER ACTIVITY REMAINS OVER EASTERN MONTANA...WITH ANOTHER AREA OF SHOWERS LIFTING NORTHEAST ACROSS FAR SOUTHEAST MONTANA INTO NORTHWEST SOUTH DAKOTA. HAVE MADE SOME POP ADJUSTMENTS...KEEPING MAINLY SLIGHT CHANCE TO CHANCE POPS THIS EVENING...AND THEN BRINGING HIGHER POPS FROM WEST TO EAST LATE TONIGHT. CONVECTION HAS ENDED IN THE NORTHWEST AND THINK THE CONVECTION OVER NORTHEAST WYOMING WILL HAVE A HARD TIME MAINTAINING ITSELF AS IT MOVES CLOSER TO NORTH DAKOTA LATE THIS EVENING. OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST. UPDATE ISSUED AT 617 PM CDT TUE MAY 6 2014 UPDATE MAINLY TO BRING A MENTION OF SHOWERS AND THUNDER TO THE NORTHWEST EARLY THIS EVENING. CONVERGENCE ALONG A WEAKENING COLD FRONT MOVING INTO THE WESTERN DAKOTAS COMBINED WITH WEAK LOW LEVEL INSTABILITY AND MODERATE SHEAR MOVING IN FROM THE WEST HAS RESULTED IN AN AREA OF SHOWERS AND ONE THUNDERSTORM CELL THAT IS CURRENTLY MOVING INTO THE FAR NORTHWEST. ISSUED A NOWCAST WITH A MENTION OF SMALL HAIL...AFFECTING SOUTHWEST DIVIDE AND NORTHWEST WILLIAMS...INCLUDING GRENORA. BUMPED UP POPS IN THE FAR NORTHWEST THROUGH WEST CENTRAL EARLY THIS EVENING...AND LOWERED POPS ACROSS THE CENTRAL...WITH ONLY SOME ISOLATED SHOWER ACTIVITY FROM BOWMAN NORTHEAST THROUGH BISMARCK TO THE CARRINGTON AREA. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 328 PM CDT TUE MAY 6 2014 PRECIPITATION POTENTIAL WILL HIGHLIGHT THE SHORT TERM FORECAST. THINNING CLOUD COVER ACROSS NORTHWEST AND MUCH OF SOUTH CENTRAL AND SOUTHEAST NORTH DAKOTA MAY LEAD TO ISOLATED TO SCATTERED SHOWER DEVELOPMENT LATE THIS AFTERNOON AND INTO THE EARLY EVENING WITH SUFFICIENT SURFACE DESTABILIZATION. THE FAR SOUTH CENTRAL NEAR THE SOUTH DAKOTA BORDER AND NORTHWEST NORTH DAKOTA DO HAVE THE POTENTIAL FOR THUNDERSTORMS WHERE MID LEVEL LAPSE RATES ARE STEEPEST. AFTER SUNSET...RAIN SHOWER ACTIVITY IS EXPECTED TO DECREASE IN COVERAGE UNTIL THE 06-08 UTC TIME FRAME WHEN PRECIPITATION INCREASES ACROSS THE WEST WHEN THE BROADER AREA OF PRECIPITATION ACROSS SOUTH CENTRAL THROUGH NORTHEAST MONTANA AS OF 20 UTC PROPAGATES EAST. WIDESPREAD RAIN SHOWER ACTIVITY WILL CONTINUE THROUGHOUT WEDNESDAY ACROSS THE CENTRAL AND SOUTHWEST...WITH A POTENTIAL DECREASE IN RAINFALL ACTIVITY NORTHWEST AS THE WEAKENING SURFACE HIGH PROPAGATES IN. FINALLY...DID ADD A MENTION OF PATCHY FOG TO MOST AREAS WITH STRATUS BUILD DOWN TONIGHT. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 328 PM CDT TUE MAY 6 2014 A PERSISTENT UPPER LEVEL LOW OVER NORTHERN SASKATCHEWAN WILL GENERATE AN UNSETTLED WEATHER PATTERN OVER NORTH DAKOTA THROUGH THE EXTENDED. WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...THE AFOREMENTIONED LOW COMBINED WITH A LONGWAVE TROUGH OVER THE ROCKIES WILL CONTRIBUTE TO PERSISTENT RAIN SHOWER CHANCES OVER WESTERN AND CENTRAL NORTH DAKOTA WEDNESDAY NIGHT...AND IN CENTRAL AND SOUTHWESTERN NORTH DAKOTA ON THURSDAY...AND SOUTH CENTRAL NORTH DAKOTA THURSDAY NIGHT. THE MODEL CONSENSUS CONTINUES TO INDICATE THE HIGHEST RAINFALL AMOUNTS OVER SOUTH CENTRAL NORTH DAKOTA...WITH AREAS ALONG AND SOUTHEAST OF A LINE FROM SIOUX AND GRANT COUNTY TO BISMARCK/MANDAN TO CARRINGTON RECEIVING ANYWHERE FROM 1/2 INCH TO NEARLY 1 INCH IN THIS 36-HOUR PERIOD. PRECIPITATION TOTALS FROM TUESDAY NIGHT THROUGH THURSDAY NIGHT...AREAS ALONG AND SOUTHEAST OF A BOWMAN TO DICKINSON...TO GARRISON TO RUGBY MAY EXPECT ANYWHERE FROM 1/2 INCH TO 1 1/4 INCHES OF PRECIPITATION. A BREAK IN PRECIP CHANCES IS FORECAST FOR FRIDAY AS A WEAK SHORTWAVE RIDGE SNEAKS UNDER THE PERSISTENT SASKATCHEWAN LOW. TEMPERATURES ARE EXPECTED TO REACH INTO THE 60S FRIDAY. THE SASKATCHEWAN LOW IS THEN PROGGED TO USHER IN SHORTWAVE AFTER SHORTWAVE OVER NORTH DAKOTA THROUGH THE REMAINDER OF THE EXTENDED. DUE TO TIMING/INTENSITY UNCERTAINTIES...BROADBRUSHED CHANCE POPS OVER THE FORECAST AREA SATURDAY THROUGH TUESDAY. TEMPERATURES WILL LIKELY REMAIN BELOW NORMAL...MAINLY HIGHS IN THE 50S...WITH THE UNSETTLED WEATHER PATTERN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1150 PM CDT TUE MAY 6 2014 AN AREA OF IFR CIGS WILL EXPAND ACROSS THE WEST THROUGH 12Z IMPACTING KISN/KDIK. IN COMBINATION WITH THE LOWERING CIGS WEST WILL BE AN AREA OF RAIN SHOWERS MOVING NORTHEAST FROM WESTERN SOUTH DAKOTA. THIS WILL SLIDE INTO KDIK AND KBIS BEFORE 12Z WEDNESDAY. LIGHT RAIN SHOWERS WILL CONTINUE AT KISN AS MOISTURE IS REPLENISHED IN EASTERN MONTANA AND MOVING NORTHEAST WITH TIME. IFR CIGS AND MVFR VSBYS CAN BE EXPECTED AT KMOT/KDIK FROM AROUND 12Z TUESDAY THROUGH 06Z WEDNESDAY. MVFR CIGS ARE FORECAST FOR KBIS. KJMS WILL REMAIN VFR UNTIL 03Z WEDNESDAY...AS THE BULK OF THE STEADY RAIN SHOWERS ARRIVE AFTER 06Z THURSDAY. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KS SHORT TERM...AYD LONG TERM...JV AVIATION...KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
418 AM EDT WED MAY 7 2014 .SYNOPSIS... A WARM FRONT WILL LIFT NORTH THROUGH THE OHIO VALLEY TODAY...ALLOWING FOR TEMPERATURES WELL ABOVE NORMAL TODAY AND THURSDAY. SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE AREA ON FRIDAY AND SATURDAY...AS A COLD FRONT SLOWLY MOVES EAST THROUGH THE REGION. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A RATHER HEALTHY BAND OF CONVECTION HAS DEVELOPED IN SOUTHERN MICHIGAN AND NORTHWESTERN OHIO...ALONG AN AXIS GENERALLY PARALLEL TO (BUT A COUPLE HUNDRED MILES REMOVED FROM) THE SURFACE WARM FRONT. OBVIOUSLY ELEVATED IN NATURE...THIS CONVECTION IS ON A TRAJECTORY TO MISS THE ILN FORECAST AREA ENTIRELY. JUST A SLIGHT CHANCE OF A SHOWER HAS BEEN KEPT IN THE FAR NORTHERN/NORTHEASTERN ILN COUNTIES FOR A FEW HOURS. RIDGING IS ALREADY BUILDING INTO THE FORECAST AREA...WITH 925MB TEMPERATURES ALREADY BEGINNING TO RISE. THE ACTUAL SURFACE WARM FRONT WILL CROSS THE CWA FROM SOUTH TO NORTH BETWEEN EARLY THIS MORNING AND AROUND 18Z...SHIFTING FLOW TO THE SOUTHWEST THROUGH THE COLUMN...SETTING UP A FAVORABLE WARM ADVECTION PATTERN. ALL SIGNS POINT TO A WELL MIXED BOUNDARY LAYER TODAY...WHICH SHOULD ALLOW FOR A SIGNIFICANT WARMING IN TEMPERATURES TO THE LOWER TO MID 80S...AS WELL AS WIND GUSTS INTO THE 20-30 MPH RANGE. RECORD HIGHS FOR TODAY (MAY 7) APPEAR TO BE SAFE. CMH: 87 / 1936 DAY: 87 / 1926 AND 1897 CVG: 89 / 1940 ONLY THE RAP (WITH ITS OVER-MIXED BOUNDARY LAYER TENDENCIES) HAD VALUES ANYWHERE NEAR THOSE NUMBERS. THIS FORECAST WILL STAY A FEW DEGREES BELOW THE RAP...BUT ON THE HIGHER SIDE OF THE REST OF THE GUIDANCE. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... CONTINUED SOUTHWESTERLY FLOW WILL LEAD TO MILD CONDITIONS TONIGHT...BEFORE ANOTHER VERY WARM DAY IS EXPECTED ON THURSDAY. THE OVERALL WEATHER PATTERN WILL BE CHANGING VERY LITTLE...WITH MID-LEVEL RIDGING OVER THE OHIO VALLEY (EXTENDING FROM THE SOUTHEASTERN STATES). ANOTHER WELL-MIXED DAY WITH APPRECIABLE AMOUNTS OF SUN WILL LEAD TO SIMILAR TEMPERATURES TO WEDNESDAY...PERHAPS EVEN A FEW DEGREES WARMER. RECORD HIGHS FOR ALL THREE CLIMATE SITES ARE 89 DEGREES FOR MAY 8...AND AGAIN AS ON WEDNESDAY...THESE LOOK TO BE SAFE. GOING INTO FRIDAY...A BROAD UPPER TROUGH WILL BE MOVING NORTHEAST FROM THE PLAINS INTO CANADA...WITH A SURFACE LOW FORECAST TO RIDE ALONG THE TROUGH THROUGH MINNESOTA AND INTO NORTHERN ONTARIO. A COLD FRONT WILL EXTEND FROM SOUTH OF THIS LOW AND WILL MOVE INTO THE OHIO VALLEY ON FRIDAY. WITH THE LOW SO FAR AWAY FROM THE REGION...AND THE MID-LEVEL FLOW FAILING TO BECOME PARTICULARLY SHARP...THERE IS LITTLE IMPETUS FOR THE FRONT TO MAINTAIN ITS STRENGTH AS IT LUMBERS EASTWARD. THIS SETS UP FORECAST WITH SPECIFICS THAT REMAIN RATHER UNCERTAIN...WITH CONCERNS OF TIMING AND FORCING STRENGTH PRECLUDING ANY HIGHER THAN 70-PERCENT POPS DURING THE SPAN FROM FRIDAY THROUGH SATURDAY (EVEN THOUGH IT IS VERY LIKELY THAT THE ENTIRE CWA WILL GET SOME RAIN OUT OF THIS SYSTEM). THE FIRST WAVE AHEAD OF THE FRONT (MOVING INTO THE ILN CWA ON FRIDAY MORNING) APPEARS TO FALL APART AS IT GETS TOO FAR AHEAD OF THE SURFACE TROUGH...AND THE BIGGEST QUESTION WITH THE SECOND WAVE IS THE TIMING (WITH A FEW MODELS NOW SHOWING THIS MORE AS A FRIDAY NIGHT ISSUE THAN A SATURDAY ONE). WITH QUESTIONABLE LOW-LEVEL MOISTURE ON FRIDAY (LIMITING INSTABILITY)...AND THE WEAK FORCING AND SLOW FRONTAL MOTION ALSO FACTORED IN...THE THREAT FOR STRONG STORMS APPEARS RATHER LOW. THE PLACEMENT OF THE SECOND WAVE WILL END UP DETERMINING IF ANY CHANCE FOR HEAVY OR PROLONGED RAIN MIGHT LEAD TO A POSSIBILITY OF FLOODING...BUT THIS ALSO APPEARS TO BE A LOW-END THREAT. TEMPERATURES WILL ALSO BE HELD DOWN BY THE OCCASIONAL RAIN AND PERSISTENT CLOUD COVER...WITH A GRADIENT FROM THE MID 70S (NW CWA) TO NEAR 80 (SE CWA) ON FRIDAY...THEN NEAR 70 DEGREES EXPECTED ON SATURDAY. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... MODEL SOLUTIONS DIVERGE THEREAFTER. ELECTED TO GO CLOSER TO THE ECMWF WHICH...AFTER AN INTERLUDE OF SOMEWHAT DRIER CONDITIONS ON SUNDAY AND MONDAY...BRINGS THE NEXT COLD FRONT CONTAINING A CHANCE OF THUNDERSTORMS ON TUESDAY. EXPECT HIGH TEMPERATURES PRIMARILY IN THE 70S. THE EXCEPTION MAY BE ON MONDAY...WHEN WARM ADVECTION MAY PUSH READINGS INTO THE LOWER 80S. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... A MID LEVEL RIDGE WILL BUILD NORTH INTO THE SOUTHERN GREAT LAKES TODAY. AS THIS OCCURS...A WARM FRONT WILL LIFT NORTH ACROSS THE REGION THIS MORNING. THERE MAY BE ENOUGH LIFT/ASCENT AHEAD OF THE FRONT FOR AN ISOLATED SHOWER/THUNDERSTORM NEAR THE KCMH/KLCK TERMINALS. GIVEN THE LOW PROBABILITY...THE TAFS WILL BE KEPT DRY. FOR THIS AFTERNOON...REGION WILL BE LOCATED IN THE WARM SECTOR. DAYTIME MIXING WILL RESULT IN SOUTHERLY WINDS IN THE 10 TO 15 KNOT RANGE WITH GUSTS GENERALLY IN THE 20 TO 25 KNOT RANGE. MAINLY HIGH LEVEL CLOUDS WILL THIN SOME BY AFTERNOON. FOR TONIGHT...MID LEVEL RIDGE WILL REMAIN IN PLACE WITH MOSTLY CLEAR SKIES EXPECTED. OUTLOOK...THUNDERSTORMS POSSIBLE FRIDAY INTO SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HATZOS NEAR TERM...HATZOS SHORT TERM...HATZOS LONG TERM...CONIGLIO AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
342 AM CDT WED MAY 7 2014 .SHORT TERM...THROUGH FRIDAY WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY CONTINUES BOTH SOUTH AND WEST OF THE CWA THANKS TO SOUTHWEST FLOW ALOFT WITH WEAK EMBEDDED WAVES. THE 06Z HRRR BRINGS CONVECTIVE REMNANTS INTO THE WESTERN CWA THROUGH THE MORNING HOURS...BUT HAVE ALREADY SEEN SIMILAR ATTEMPTS BY SHOWERS TO CROSS INTO THE FORECAST AREA...ONLY TO WASH OUT...SO FORECASTER CONFIDENCE CONTINUES TO REMAIN LOW EVEN IN THE NEAR TERM. MODELS DO HAVE A BETTER DEFINED WAVE MOVING UP FROM THE SOUTH TODAY. BEST ISENTROPIC FORCING WILL SET UP JUST NORTH OF A KMBG TO KPHP LINE. INSTABILITY PEAKS JUST SOUTH OF A WARM FRONT FOR THE EASTERN CWA THIS AFTERNOON AS WELL. LOOKING AT NAM/RAP PROFILES...SURFACE BASED CONVECTION APPEARS UNLIKELY AS THE FRONT IS SOUTH OF THE CWA...AND GUIDANCE HAS A DIFFICULT TIME WARMING ENOUGH TO OVERCOME THE INVERSION. STEEP LAPSE RATES ABOVE THE INVERSION WITH STRONG SOUTHWEST MID LEVEL FLOW WILL SUPPORT A HAIL THREAT IF ANY STORMS DO DEVELOP. OVERNIGHT...A COUPLED JET STRUCTURE WILL SUPPORT AN AREA OF RAIN THAT WILL LIFT OUT OF THE NEBRASKA PANHANDLE THROUGH WESTERN/CENTRAL SOUTH DAKOTA. MOST OF THE GUIDANCE TAKES THIS FEATURE NORTHEAST BETWEEN KPIR AND KMBG...THOUGH SREF GUIDANCE IS A TAD FARTHER WEST. SREF PROBABILITIES SUGGEST FAIRLY HIGH QPF POTENTIAL WITH THIS FEATURE...WHICH IS SUPPORTED WITHIN MOST GUIDANCE. THE GFS IS PEGGED AT NEARLY 30 MICROBARS OF LIFT BY 12Z THURSDAY. TROWAL WRAP AROUND LIGHT RAIN WILL CONTINUE THROUGH THE DAY...BUT WE WILL SEE ISENTROPIC DOWNGLIDE BY LATE AFTERNOON/EVENING HELPING TO DRY US OUT FOR FRIDAY. .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY THE EXTENDED PERIOD CONTINUES THE ACTIVE PATTERN WITH A COUPLE OF SYSTEMS MOVING THROUGH. THE FIRST WEAKER WAVE MOVES OFF THE ROCKIES FRIDAY NIGHT AND INTO EASTERN SD SATURDAY BRINGING SOME SHOWERS AND TSTORMS. THERE WILL LIKELY BE A BRIEF BREAK IN PRECIP SAT MORNING BEFORE A MORE WELL DEVELOPED SFC LOW ENTERS THE CENTRAL PLAINS SAT NIGHT. AT THE SAME TIME AN UPPER LOW WILL DROP DOWN INTO ND. WHILE THE MODELS AGREE ON THE SFC SYNOPTIC PATTERN...THERE IS SOME DISCREPANCY AT JUST WHEN THE UPPER TROF WILL BEGIN TO AFFECT THE NORTHERN PLAINS. THIS WILL INFLUENCE AREAL COVERAGE OF PRECIP DURING ANY GIVEN PERIOD FROM SAT NIGHT THROUGH TUESDAY. THE ECMWF KEEPS THE PRECIP ONLY OVER THE FAR SOUTHERN CWA WHILE THE GFS HAS THE ENERGY FROM THE UPPER LOW DIGGING A LITTLE FARTHER SOUTH ON SUNDAY. KEPT ALLBLEND POPS FOR NOW OVER THE WEEKEND BUT A DRIER SOLUTION IS POSSIBLE. TEMPERATURES WILL TREND DOWN THROUGH THE PERIOD WITH THE COOLEST TEMPS OCCURRING WHEN THE LONGWAVE TROUGH MOVES OVER THE PLAINS. TEMPS WILL BE AROUND 10 DEGREES COOLER THAN AVERAGE BY THE LATTER HALF OF THE EXTENDED. && .AVIATION... 06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH THE OVERNIGHT HOURS. SHOWER AND THUNDERSTORMS WILL OVERSPREAD THE WESTERN CWA DURING THE LATE MORNING AND EARLY AFTERNOON HOURS...THEN WILL SPREAD EASTWARD DURING THE LATE AFTERNOON AND EVENING. THE MOST LIKELY LOCATION TO SEE THUNDERSTORMS ACTIVITY WILL BE ACROSS THE SOUTHERN AND FAR EASTERN CWA...POSSIBLY AFFECTING KPIR AND KATY. CIGS WILL FALL INTO THE MVFR CATEGORY BY MIDDAY...THEN INTO THE VFR CATEGORY DURING THE LATE AFTERNOON HOURS. MVFR VSBYS WILL BE POSSIBLE WITH THE PRECIPITATION AS WELL. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ SHORT TERM...CONNELLY LONG TERM...WISE AVIATION...WISE WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1133 PM CDT Tue May 6 2014 .UPDATE... Increased overnight lows and introduced a slight chance of thunderstorms along the I-10 corridor and northeast into the Mason...Brady and San Saba. && .DISCUSSION... Extensive mid/upper clouds associated with the subtropical jet and isolated thunderstorms in southwest Texas were moving northeast across the region. Updated to increase lows into the upper 60s to around 70. Also introduced a slight chance of thunderstorms over areas south and east of the Concho Valley. The main threat from storms will be strong gusty winds and deadly lightning. && .AVIATION... /06Z TAFS/ MVFR stratus developing in the Hill Country was likely be delayed by extensive mid/upper cloudiness over the region. However it should eventually reach the I-10 corridor and areas around Brady around 9Z. Stratus deck may make it to San Angelo, though confidence is not high, so kept it as a scattered layer. Isolated dry line thunderstorm activity possible late Wednesday afternoon and evening, but best chance of storms will be after 06Z/Thursday, so left thunder out of this TAF issuance. && .PREV DISCUSSION... /ISSUED 633 PM CDT TUE MAY 6 2014/ AVIATION... /00Z TAFS/ Stratus with MVFR CIGS returns along the I-10 corridor around 9Z and spreads northward. A few patches of stratus may affect KSJT, but most should stay south. Winds will increase mid morning and further increase late afternoon as lee trough strengthens. Isolated dry line thunderstorm possible late Wednesday afternoon, but coverage too low to put TAFS. PREV DISCUSSION... /ISSUED 357 PM CDT TUE MAY 6 2014/ SHORT TERM... (Tonight and Wednesday) Expect hot and dry weather this afternoon and a chance of thunderstorms Wednesday afternoon. A dryline was located along a Fredrick, OK to Abilene to Sonora line at 20Z. Latest SPC mesoanaylsis indicates weak instability(MLCAPES 500 to 1000 J/KG) ahead of the dryline over the eastern part of our area. The remaining convective inhibition or low level inversion may be erased for isolated storms to develop mainly after 22Z across the northern Heartland and eastern Big Country. the HRRR convective allowing model has been showing isolated storms developing the past several hourly runs. High LCLs and an inverted-v sounding profiles favor strong gusty winds and hail with the stronger storms. Also, storms will produce dangerous cloud to ground lightning. Any storms that do develop will exit the area or quickly dissipate by 02Z. The rest of tonight will see low level southerly flow and low level moisture returning. The dryline will retreat to just west of our area by 12Z Wednesday. Lows tonight will be in the 60s to around 70. For Wednesday, the morning looks quiet with low clouds across much of the area. Low clouds will break up across much of the area by early afternoon. Aloft, a strong upper level trough will be located over the southern Rockies. A dryline will move slowly east to along a Haskell to San Angelo line by late in the afternoon. Low level convergence along the dryline and increasing large scale ascent from approaching trough will cause isolated to scattered thunderstorms to develop across much of West Central Texas mainly after 20Z. The combination of some instability(MLCAPES of 1500 to 2000 J/KG) and 0-6KM bulk shear of 45 to 50 knots, will result in some storms being severe. The main threats will be large hail, damaging winds and dangerous cloud to ground lightning. Highs will be 90 to 95. LONG TERM... (Wednesday night through next Tuesday) By Wednesday night, the large upper level trough currently near Las Vegas will be moving east through the desert southwest toward west Texas. This feature will bring synoptic scale upward motion with it into west and west central Texas from Wednesday evening into Thursday. Have generally bumped PoPs up again with this forecast, as we get closer to the event, and become more confident in thunderstorms taking place. In addition, have added the mention of severe thunderstorms to the forecast for Wednesday evening, carrying over the mention from the afternoon. With 0-6km bulk shear values of 40-55 knots, and SFC and mixed layer CAPE values ranging from near 1000 J/kg to as high as 1500 J/kg, there will be enough instability, and storm organization carried over into the evening hours for the threat of severe weather to be possible. As with the previous period, the main concerns will be large hail and damaging winds. As the event evolves overnight, the instability will wane, and thus have the mention of severe weather in the forecast only through 06Z. In addition to the severe weather possibility, some of the thunderstorms will contain heavy rainfall, and localized flooding will be possible, mainly in urban areas. On Thursday, we will likely continue to see a broken line of showers with embedded thunderstorms for the eastern half of the area, especially during the morning hours as steering flow remain southwest, making the exit of precipitation a little slow. Severe weather concern will be limited with this mainly morning activity. One more weak shortwave will move through the area Friday afternoon and evening, possibly providing one more shot at precipitation for southeastern areas Friday afternoon and night. Expect temperatures to continue to be above normal through the forecast period. Thursday and Friday will be the cooler days averaging mainly in the upper 80s to lower 90s. Temperatures will quickly warm back into the mid 90s for the weekend. Have not made any significant changes beyond the end of this week as there is still a lot of uncertainty associated with the forecast for early next week. The GFS is much more progressive and weaker with an upper level system, sending a cold front into the area Sunday night whereas the ECMWF is slower and stronger, and waits until Monday evening to send a cold front into the area. FIRE WEATHER... Critical fire weather conditions are expected this afternoon and early evening, generally west of a Haskell to Bronte line. A Red Flag Warning is in effect until 9 PM across the western Big Country and Northern Concho Valley due to RH values of 7 to 12 percent and southwest winds around 20 mph. Also, ERC values are at record levels across this area. An increase in low level moisture late tonight should result in RH values recovering to 60 to 80 percent across much of West Central Texas. Elevated fire weather conditions are expected Wednesday afternoon west of a Haskell to Ozona line due to RH values of 15 to 25 percent and wind speeds of 15 mph. Thunderstorms will bring potential wetting rains across mainly northern and eastern areas Wednesday night and Thursday. && .PRELIMINARY POINT TEMPS/POPS... Abilene 69 94 67 87 61 / 5 30 50 30 10 San Angelo 71 94 68 91 57 / 5 20 40 20 10 Junction 71 91 70 87 66 / 10 20 50 40 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 04/24
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
210 AM EDT WED MAY 7 2014 .SYNOPSIS... A FRONT WILL REMAIN STALLED ACROSS OUR REGION TONIGHT THROUGH WEDNESDAY. AN UPPER RIDGE WILL BUILD OVER THE REGION THURSDAY... RESULTING IN WARMER AND DRIER CONDITIONS. HIGH PRESSURE WILL GIVE WAY TO A SLOW MOVING FRONTAL SYSTEM LATE FRIDAY INTO SATURDAY. && .NEAR TERM /THROUGH TODAY/... AS OF 900 PM EDT TUESDAY... EVENING RNK SOUNDING SHOWING QUITE A BIT OF LOW LEVEL INSTABILITY WITH CAPES NEAR 2K BEING CAPPED ALOFT VIA A DECENT INVERSION JUST ABOVE 7H. HOWEVER LOW LEVELS REMAIN DRY WITH BETTER SURFACE COOLING ONGOING AS THE EASTERLY FLOW HAS NOW FLOPPED BACK TO AS FAR WEST AS THE BLUE RIDGE. IN ADDITION...SUPPORT ALOFT LACKING ATTM TO ERODE THE CAP ...WHILE THE SURFACE BOUNDARY REMAINS TO THE SW WHERE THE AIR REMAINS ARID ON THE WEST SIDE OF THE FRONT OVER THE NW NC RIDGES. THUS LITTLE TO TRIGGER CONVECTION THERE. HOWEVER DEWPOINTS LOOK TO SLOWLY RECOVER NORTHWARD EAST OF THE BLUE RIDGE OVERNIGHT WITH A WEAK IMPULSE SLIDING ACROSS LATE IN THE NW FLOW ALOFT. MODELS REMAIN OVERDONE WITH CONVECTION BUT APPEARS A WINDOW POSSIBLE DURING THE NEXT FEW HOURS INTO THE EARLY MORNING HOURS OVER THE FAR NORTH TO SEE A FEW BANDS OF SHRA/TSRA WITH THIS FAINT FEATURE. GIVEN CURRENT LACK OF COVERAGE BASICALLY REMOVED POPS EARLY THIS EVENING...AND CUT BACK TO MOSTLY ISOLATED TO CHANCE COVERAGE NORTH OF HIGHWAY 460 DURING THE OVERNIGHT. OTRW EXPECT LOW CLOUDS TO FILL BACK IN ESPCLY EAST AS THE WEDGE DEEPENS AGAIN WITH MAINLY CLEAR SKIES OVER THE WEST/SW. SOME PATCHY FOG ALSO POSSIBLE OUT EAST AND IN THE VALLEYS BUT QUITE SPOTTY. ADJUSTED LOWS DOWN SOME BLUE RIDGE EAST PER EASTERLY FLOW AND BUMPED UP WEST GIVEN SLOW TO FALL READINGS AND MORE OF A LIGHT WEST WIND THROUGH DAYBREAK. UPDATE AS OF 630 PM EDT TUESDAY... EARLY UPDATE TO REMOVE GOING POPS ACROSS THE REGION INTO THIS EVENING GIVEN LOW LEVEL DRY AIR IN PLACE PER OBS/MSAS AND LACK OF MUCH CONVERGENCE OR SHRA. STILL POTENTIAL FOR ISOLATED COVERAGE TO BREAK THE CAP ALOFT SEEN OFF EARLIER SOUNDINGS BUT CURRENT CLOUD FIELDS AND LATEST MODELS SUGGEST MAY BE LATER WHEN A WEAK IMPULSE ALOFT RIDES IN FROM THE NW. OTRW STILL SEEING QUITE A SPREAD IN TEMPS FROM THE WEDGING IN THE NE TO THE VERY WARM TEMPS OVER THE SW WHERE THE AIR IS VERY DRY PER HUMIDITY LEVELS BELOW 20 PERCENT. WILL LEAVE IN CURRENT CHANCE POPS AFTER SUNSET WHEN MAY SEE MOISTURE POOL ALONG THE BLUE RIDGE OTRW RUNNING DRY OVER THE NEXT COUPLE OF HOURS PER THE LATEST HRRR. PREVIOUS DISCUSSION AS OF 330 PM EDT TUESDAY... FRONTAL BOUNDARY REMAINS ACROSS REGION THROUGH TONIGHT. SHORTWAVE COMES OVER UPPER RIDGE INTO THE FORECAST AREA LATE TONIGHT. DESPITE SOLAR HEATING...STRONG CAP THIS AFTERNOON HINDERING CONVECTION DEVELOPMENT. WEAK DPVA ASSOCIATED WITH SHORTWAVE MAY BE ABLE TO OVERCOME THE HEALTHY CAP. LIKE YESTERDAY...SWODY1 ADDED THE MENTION OF A SEE TEXT FOR ISOLATED SEVERE THUNDERSTORMS WITH A HAIL AND WIND THREAT FOR VIRGINIA. MODIFIED FCST SOUNDINGS SUGGEST RELATIVELY COLD AIR ALOFT AND GOOD LAPSE RATES FOR THIS AFTERNOON INTO TONIGHT. RNK WRFARW DEVELOPS SOME CONVECTION THIS AFTERNOON ACROSS THE NORTH TO NORTHEAST CORNER OF CWA AND DROP SOUTHEAST. HRRR SHOWED SOME ISOLATED CONVECTION ACROSS THE NORTH THIS EVENING INTO TONIGHT. GFS AND ECMWF STILL SHOWING SCATTERED CONVECTION ACROSS THE NORTH WITH WAA TONIGHT. WILL KEEP ISOLATED TO SCATTERED CONVECTION IN FOR THIS EVENING INTO TONIGHT ACROSS THE NORTH. BUT...HAVE CONCERNS THAT CAP MAY HOLD AND LIMITED CONVECTION. PLAYED LOW TEMPERATURES CLOSE TO ADJMAVBC WITH READINGS FROM LOWER 50S IN THE NORTHERN MOUNTAINS TO THE UPPER 50S IN THE PIEDMONT. THE H8 WARN FRONT LIFTS NORTH ON WEDNESDAY. BEST LIFT AND INSTABILITY IS ACROSS THE NORTH FOR WEDNESDAY. GOOD LAPSE RATE AND ELEVATED INSTABILITY SUPPORT MENTION OF SHOWERS AND ISOLATED ACROSS THE NORTH. FLOW BECOME SOUTHERLY IN THE SOUTH ON WEDNESDAY AND CAP IS EVEN STRONGER...ELECTED TO KEEP MENTION OF STORMS OUT OF SOUTHERN PORTIONS OF FA. HIGH TEMPERATURES ON WEDNESDAY CHALLENGING FOR THE NORTHEASTERN THIRD OF THE CWA WITH CLOUDS AND POTENTIAL CONVECTION. HIGH TEMPERATURES ON WEDNESDAY WILL VARY FROM AROUND 70 IN THE NORTH TO THE LOWER TO MID 80S IN THE FAR SOUTHWEST AND ALONG THE FOOTHILLS OF THE SOUTHERN BLUE RIDGE MOUNTAINS. && .SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... AS OF 330 PM EDT TUESDAY... TEMPERATURES WELL ABOVE NORMAL TO FINISH OFF THE WORK WEEK. HIGH AMPLITUDE UPPER LEVEL FLOW WILL SUBJECT FORECAST AREA TO A SURGE OF VERY WARM AIR THURSDAY AND FRIDAY. AN UPPER LEVEL RIDGE OF HIGH PRESSURE IS EXPECTED TO AMPLIFY INTO THE 582 TO 588 DM RANGE OVER THE EASTERN CONUS...AXIS RUNNING NORTH-SOUTH FROM ONTARIO CANADA TO FLORIDA. THE GREATEST AMPLITUDE IS EXPECTED THURSDAY... THEN BREAKING DOWN FRIDAY AS A MID CONUS TROF MOVES EAST. 850 MB TEMPS THURSDAY ARE PROGGED NEAR 18 DEG C. THIS ALONE WILL PROMOTE TEMPERATURES WELL INTO THE 80S. AN ADDED BOOST WILL OCCUR FROM ADIABATIC WARMING...WESTERLY WINDS RESULTING IN COMPRESSIONAL HEATING AS THE AIR PASSES OVER AND DOWN THE MTNS. THE NET EFFECT WILL BE TEMPERATURES WHICH WILL TEST THE 90 DEGREE MARK ON THE EAST SIDE OF THE MOUNTAINS THURSDAY...AND TO A LESSER DEGREE FRIDAY AS THE WINDS BACK MORE TOWARD THE SOUTHWEST AHEAD OF THE APPROACHING MID CONUS TROUGH. STRONG SUBSIDENCE THURSDAY WILL SQUELCH ANY CHANCE OF SHOWER ACTIVITY YIELDING A MOSTLY SUNNY DAY. AS THE SUBSIDENCE WEAKENS FRIDAY...SHOULD SEE A BIT MORE CUMULUS...BUT THINK ANY THREAT OF SHOWER OR STORM ACTIVITY WILL HOLD OFF UNTIL LATE UNLESS AN OUTFLOW BOUNDARY MOVES EAST OF THE MAIN MID CONUS FRONT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 330 PM EDT TUESDAY... VARIABILITY IN THE MODELS LEADS TO A LOW CONFIDENCE FORECAST... ESPECIALLY NEXT WEEK. SATURDAY IS THE ONLY DAY WHERE THE MODELS REMOTELY LOOK SIMILAR...THEN THEY DIVERGE RESULTING IN DIFFERING SOLUTIONS FOR SUNDAY THROUGH TUESDAY. THE GFS IS PROGRESSIVE AND AND FAVORS ZONAL FLOW ALOFT NEXT WEEK VS. THE MORE AMPLIFIED ECMWF. FOR SATURDAY BOTH MODELS BRING SURGE OF MOISTURE INTO THE AREA AHEAD OF APPROACHING SURFACE FRONT. THIS RESULTS IN LIKELIHOOD OF SHOWERS AND POSSIBLE THUNDERSTORMS...ESP ACROSS THE MOUNTAINS. THE GFS THEN PUSHES THE FRONT THROUGH THE AREA QUICKLY WITH ANOTHER FRONT COMING THROUGH ABOUT TUESDAY. THE ECMWF SLOWS SATURDAYS FRONT WITH TROUGHING LINGERING THROUGH THE WEEKEND...FOLLOWED BY HIGHER AMPLITUDE RIDGING ALOFT EARLY NEXT WEEK WITH THE SURFACE FRONT GETTING CAUGHT UNDERNEATH THE RIDGE. THIS RESULTS IN A WETTER SOLUTION THIS WEEKEND FOLLOWED BY A DAY OR TWO OF EASTERLY LOW LEVEL FLOW MONDAY AND TUESDAY UNTIL WE MIX OUT THE MIDDLE OF NEXT WEEK. SINCE THE CURRENT PATTERN FAVORS A MORE AMPLIFIED SOLUTION WILL ENTERTAIN A FORECAST CLOSER TO THE ECMWF. AS SUCH TRENDED THE FORECAST CLOUDIER AND COOLER TO START THE WEEK...TEMPERATURES MONDAY AND TUESDAY CLOSER TO NORMAL ALONG WITH A CHANCE OF SHOWERS. BY MID WEEK...FLOW ALOFT SHOULD BECOME SOUTHWEST WITH ANOTHER WARM SURGE PRIOR TO ANY FRONTAL PASSAGE IN THE WEDNESDAY...THURSDAY TIME FRAME. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 150 AM EDT WEDNESDAY... CONSIDERABLE UNCERTAINTY AT THIS POINT REGARDING THE DEVELOPMENT...TIMING...AND DURATION OF LOW CLOUDS AND ASSOCIATED MVFR TO IFR CIGS AND MVFR VSBYS. BACK DOOR FRONT SHIFTED BACK TO THE WEST AFTER SUNSET...AND NOW APPEARS TO BE BACK INTO FAR SW VA NEAR MKJ. E-ENE WINDS EVIDENT ACROSS MOST OF THE CWA...OR CALM BCB/LWB. ALL MODELS POINT TOWARD THE COOLER...EASTERLY MARITIME FLOW DOMINATING MUCH OF THE DAYTIME TODAY AS OPPOSED TO YESTERDAY. THIS WILL OCCUR AS FAIRLY TYPICAL WEDGE SUPPORTING PATTERN OF UPPER RIDGE BUILDING OVER SFC WEDGE/COLD AIR DAMMING. AS OF NOW...THERE IS LITTLE TO NO EVIDENCE OF LOW CLOUDS ACROSS THE PIEDMONT OR COASTAL PLAIN...BUT WATCHING POTENTIAL DEVELOPMENT OF LOW CLOUDS ALONG THE BLUE RIDGE IN 11-3.9UM SATELLITE...WITH SCT036 JUST NOW APPEARING IN ROA MTR. OTHER PATCHES OF LOW CLOUDS BEGINNING TO APPEAR NEAR LYH. AMENDMENTS/ADJUSTMENTS LIKELY AS LOW CLOUD DEVELOPMENT BECOMES MORE APPARENT. MEANWHILE...EXTENSIVE MID CLOUDS IN THE 080-090 RANGE WILL CONTINUE TO SPREAD ACROSS THE REGION FROM NW-SE IN NW FLOW ALOFT THROUGH THE MORNING HOURS. THEN...THIS BAND OF CLOUDS WILL BEGIN TO LIFT NORTHWARD TOWARD MD/PA AS UPPER RIDGE AMPLIFIES. ONCE THE CLOUD COVER DEVELOPS...MANY QUESTIONS ALSO ARISE AS TO THE DURATION OF SUCH...WITH MOST MODEL GUIDANCE SUGGESTING IT WILL REMAIN IN PLACE THROUGH LATE MORNING/EARLY AFTERNOON AT LEAST. THIS SEEMS TO BE A GOOD COMPROMISE AT THIS POINT...AS SYNOPTIC PATTERN COULD SUPPORT SUCH CLOUDS REMAINING IN PLACE MOST OF THE DAY EAST OF THE BLUE RIDGE. SOME POTENTIAL FOR MVFR VSBYS IN BR LATE NIGHT/EARLY MORNING HOURS...BUT OVERALL POTENTIAL FOR SUCH APPEARS LESS THAN YESTERDAY WITH STRATUS LOOKING MORE LIKELY TODAY. THIS IS SUPPORTED BY BUFKIT SOUNDINGS AS WELL. WINDS TODAY SHOULD GENERALLY BE ESE-SE MOST SITES AT SPEEDS OF 5-8KTS...BECOMING CALM/VRB03KT AROUND 00Z THU. LOW CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD. MEDIUM CONFIDENCE IN VSBYS THROUGH 15Z...THEN HIGH CONFIDENCE IN VFR VSBYS. HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION DISCUSSION... THURSDAY...THE FRONT LIFTS TO THE NORTH WITH WARMER AIR ALOFT PUTTING A CAP ON ANY CONVECTION UNDER VFR CU FIELDS. BY LATE FRIDAY A COLD FRONT WILL APPROACH FROM THE WEST...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS DURING THE EVENING. BETTER CHANCE FOR SUB-VFR AT TIMES SAT AFTERNOON/EVENING WITH THE FRONT SLOWLY MOVING EAST AND DEEPER MOISTURE IN PLACE. BOUNDARY MAY WASH OUT UPON CROSSING THE AREA BY SUNDAY WITH MAINLY VFR CONDITIONS EXPECTED OUTSIDE OF OCNL MVFR IN SCATTERED AFTERNOON/EVENING SHRA. && .CLIMATE... HIGH TEMPERATURE RECORDS IN THE MOUNTAINS ARE IN JEOPARDY THURSDAY. MAY GET CLOSE IN THE EAST. CURRENT RECORDS FOR MAY 8TH... ROANOKE......94/1940 LYNCHBURG....94/1940 DANVILLE.....92/1986 BLACKSBURG...85/2000 BLUEFIELD....84/2004 LEWISBURG....82/2000 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...KK NEAR TERM...JH/KK SHORT TERM...PM LONG TERM...PM AVIATION...JH/RAB CLIMATE...PM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
425 AM CDT WED MAY 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 425 AM CDT WED MAY 7 2014 AT 3 AM...WATCHING 2 AREAS OF CONVECTION. THE FIRST IS LOCATED OVER EAST CENTRAL WISCONSIN. MEANWHILE THE OTHER ONE IS LOCATED BETWEEN SIOUX FALLS SOUTH DAKOTA AND FAIRMONT MINNESOTA. BOTH OF THESE ARE LOCATED ON THE EASTERN EDGE STRONG 700 MB MOISTURE CONVERGENT AREA. IN ADDITION...THEY ARE LOCATED ONE THE NORTHERN PERIPHERY OF 1000 J/KG MOST UNSTABLE CAPE. THE ARW...NMM...HOP WRF AND SPC WRF SUGGEST THAT THE LATTER AREA OF CONVECTION WILL MOVE EAST ALONG THE INTERSTATE 90 CORRIDOR THIS MORNING. EARLIER IN THE NIGHT THE HRRR SUGGESTED A SIMILAR SCENARIO...BUT WITH ITS LATEST RUN IT HAS BACKED AWAY FROM THIS SOLUTION. HOWEVER THIS SCENARIO DOES NOT MAKE A LOT OF SENSE...SO BACKED AWAY FROM FOLLOWING IT. TRENDED THE PRECIPITATION FORECAST FOR TODAY TOWARD A BLEND OF ARW...NMM...HOP WRF AND SPC WRF. HOWEVER I AM A BIT CONCERNED THAT AS IT MOVES EAST THAT THE NOCTURNAL JET WILL WEAKEN AND THAT THE CONVECTION COULD DISSIPATE BEFORE IT GETS INTO OUR AREA. IF THE CONVECTION DOES HAPPEN TO GET INTO OUR AREA...THE SPC RAP SUGGESTS THAT EFFECTIVE SHEAR WILL INCREASE OVER 40 KNOTS THROUGH 07.14Z. THIS COULD RESULT IN THE DEVELOPMEMT OF SOME ELEVATED SUPER CELLS. WE WILL HAVE TO MONITOR THIS OVER THE NEXT COUPLE OF HOURS. FOR LATER THIS MORNING AND AFTERNOON...MANY OF THE MESO MODELS AND AND NAM SUGGEST THAT THE AREA WILL REMAIN DRY. THIS IS A RESULT OF AN ELEVATED MIXED LAYER BEING BROUGHT ISENTROPICALLY OFF OF THE SOUTHERN PLAINS. THIS LAYER FORMS A STRONG 800 TO 600 MB CAP ACROSS THE FORECAST AREA. MEANWHILE THE GFS CONTINUES TO TRY AND DEVELOP STRATIFORM PRECIPITATION BELOW THE CAP. THIS LOOKS VERY UNLIKELY BECAUSE ITS SATURATED THE AIR MASS BELOW 800 MB TOO MUCH. DUE TO THIS...STAYED WITH A DRY FORECAST FOR THE TIME PERIOD. TONIGHT...MANY OF DETERMINISTIC RUNS ARE GENERATING PRECIPITATION ACROSS MUCH OF THE FORECAST AREA. HOWEVER BUFKIT SOUNDINGS CONTINUE TO SHOW A FAIRLY STRONG CAP ALONG AND SOUTH OF INTERSTATE 94. THIS IS GOOD AGREEMENT WITH WHAT SHOWS UP IN THE ARW AND SPC WRF. DUE TO THIS...WENT WITH MUCH LOWER POPS THAN WHAT NORMALLY WOULD BE EXPECTED SOUTH OF INTERSTATE 94. IF THUNDERSTORMS DID DEVELOP...IT LOOKS TO BE SO HIGH /BASES OF 2 TO 3 KM/ THAT YOUR SHEAR IS GREATLY DECREASED TO LESS 25 KNOTS...SO THERE WILL NOT BE SUPERCELLS. HOWEVER THE CAPE PROFILE IS MUCH FATTER THAN THIS MORNING AND THIS COULD POTENTIALLY RESULT IN SOME LARGE HAIL. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 425 AM CDT WED MAY 7 2014 ON THURSDAY AND THURSDAY NIGHT...THE 07.00Z MODELS CONTINUE TO SHOW THAT A PLUME OF SUBTROPICAL MOISTURE WILL SURGE NORTHWARD AHEAD OF THE LONG WAVE TROUGH. EMBEDDED WAVES IN THIS FLOW WILL RESULT IN SHOWERS AND THUNDERSTORMS WHICH WILL USE UP MUCH OF THE CAPE PRIOR TO THE ARRIVAL OF A MUCH MORE FAVORABLE SHEAR PROFILE. DUE TO THIS...STILL THINKING THAT THE BEST SEVERE WEATHER THREAT WILL REMAIN WEST OF INTERSTATE 35. WITH THIS PLUME NOT ARRIVING UNTIL MID MORNING...LOWERED THE PRECIPITATION PROBABILITIES BETWEEN 08.12Z AND 08.15Z. FROM SATURDAY NIGHT THROUGH TUESDAY...A SERIES OF SHORT WAVE TROUGHS WILL EJECTED OUT OF THE LONG WAVE OVER THE WESTERN UNITED STATES. THIS WILL BRING ROUND OF SHOWERS AND THUNDERSTORMS INTO THE AREA. WITH STILL SOME TIMING DIFFERENCES AND SUBTLE DIFFERENCES IN THE MODELS...STAYED WITH THE MODEL CONSENSUS. TOWARD THE MIDDLE OF NEXT WEEK...IT LOOKS LIKE THERE WILL BE A PATTERN SHIFT AS THE UPPER LEVEL FLOW BECOMES NORTHWEST AND WEST ACROSS THE EASTERN UNITED STATES. LOOKS LIKE HIGHS MAY RANGE FROM THE UPPER 40S TO MID 50S...AND LOWS WILL RANGE FROM THE MID 30S TO MID 40S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1141 PM CDT TUE MAY 6 2014 SAW ONE BAND OF SHRA/TS DEVELOP EAST OF KLSE EARLIER THIS EVENING...BUT THAT HAS SINCE MOVED INTO EAST CENTRAL WI. FAIRLY QUIET AT THE MOMENT UPSTREAM PER RADAR MOSAIC AND SURFACE OBSERVATION IN ADVANCE OF A WARM FRONT LIFTING NORTHWARD OUT OF THE CENTRAL PLAINS. MODELS PUSHING THE WARM FRONTAL BOUNDARY INTO THE AREA WEDNESDAY...TO ALONG I-94 BY WEDNESDAY EVENING. A FEW OF THE MODELS STILL DEVELOPING SHRA/TS ACTIVITY OVERNIGHT WITH SURGE OF MOISTURE/LIFT OUT AHEAD OF THE FRONT...BUT STILL A FAIR AMOUNT OF UNCERTAINTY THOUGH BETWEEN THE MODELS ON COVERAGE OF THIS SHRA/TS ACTIVITY AND WHETHER KLSE/KRST WILL BE AFFECTED. WILL MAINTAIN VCSH/VCTS IN THE TAFS IN THE 06-13Z TIMEFRAME. OTHERWISE...VFR CONDITIONS EXPECTED. BACKED OFF ON MVFR STRATOCUMULUS IN THE MORNING DUE TO LACK OF WIDESPREAD PRECIPITATION AND BOUNDARY LAYER MOISTENING. PLAN ON VFR CONDITIONS THROUGH THE REST OF THE PERIOD AS WELL WITH ANY CONVECTION ASSOCIATED WITH THE WARM FRONT EXPECTED TO REMAIN NORTH OF THE KRST/KLSE TAF SITES. && .HYDROLOGY... ISSUED AT 425 AM CDT WED MAY 7 2014 FLOODING CONTINUES ALONG THE MAIN STEM OF THE MISSISSIPPI RIVER...WITH LOCATIONS CRESTING FROM NORTH MCGREGOR. SHOWERS AND THUNDERSTORMS ON THURSDAY AND THURSDAY NIGHT WILL PRODUCE ANYWHERE FROM A HALF INCH TO ONE INCH. THIS WILL LIKELY SLOW THE FALL FOR LOCATIONS NORTH OF MCGREGOR...AND MAY INCREASE CRESTS SLIGHTLY SOUTH OF MCGREGOR. CHECK OUT THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...DAS HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1110 PM MDT TUE MAY 6 2014 .SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY NIGHT) ISSUED AT 320 PM MDT TUE MAY 6 2014 HIGH CLOUD COVER LIMITED SFC HEATING OVER MUCH OF THE PLAINS THROUGH MIDDAY...HOWEVER MUCH BETTER CLEARING IS NOW SEEN OVER THE CWA. DEWPOINTS ACROSS THE PLAINS ARE LARGELY IN THE 40S SO THERE IS DECENT LLVL MOISTURE. WOULD BE MOST CONCERNED ABOUT STRONG TO MARGINALLY SEVERE STORMS IN CONVERSE COUNTY. THE RUC INDICATES AROUND 1000 J/KG OF SFC BASED CAPE THROUGH THE EARLY EVENING ALONG WITH GOOD DEEP LAYER SHEAR OF 50 KTS. THE HRRR MODELS HAS ALSO BEEN CONSISTENT AT SHOWING A DISCRETE CELL JUST TO THE NORTH OF CONVERSE COUNTY. NOT AS MUCH INSTABILITY (AROUND 500 J/KG OF CAPE) IS FCSTED OVER THE WESTERN NEBRASKA PANHANDLE...SO NOT AS CONCERNED ABOUT STRONG STORMS OUT THERE. ANY STORMS THAT DO DEVELOP SHOULD WEAKEN BY LATE EVENING. ONE MORE MILD NIGHT ACROSS THE CWA AHEAD OF THE UPPER TROUGH THAT IS LOCATED OVER UTAH. SFC LOW STRENGTHENS OVER NORTHEASTERN COLORADO BY LATE WED MORNING WITH NORTHEAST WINDS DEVELOPING ACROSS THE PLAINS. WEATHER CONCERN FROM LATE MORNING WED THROUGH THE AFTN WILL BE ON THE SEVERE THREAT OVER THE EXTREME SOUTHEASTERN PART OF THE CWA. SPC HAS A SLIGHT RISK OVER THE SOUTHERN HALF OF THE PANHANDLE. CAPE VALUES INCREASE TO AROUND 1000 J/KG BY 18Z ALONG INTERSTATE 80 IN THE SOUTHERN PANHANDLE. 0-3 KM HELICITY IS CLOSE TO 300 ALONG 0-6 KM SHEAR VALUES OF 55 KTS. THINKING THAT HAIL WILL BE THE PRIMARY THREAT...BUT CAN NOT RULE OUT A WEAK TORNADO WITH THE GOOD LLVL SHEAR. THE WINDOW FOR SVR WEATHER SHOULD NOT EXTEND MUCH LATER THAN THE EARLY AFTN HOWEVER...AS WINDS BECOME NORTHERLY BY LATE AFTN AND INSTABILITY IS ON THE DECREASE BEHIND THE FRONT. THE MODELS HAVE BEEN CONSISTENT WITH THE TRACK OF THE UPPER LEVEL SYSTEM. IT PUSHES INTO NORTHEASTERN COLORADO ON WED EVENING AND THEN BEGINS TO CLOSE OFF OVER SOUTHWESTERN NEBRASKA BY LATE WED NIGHT. A TROWAL IS SHOWN PUSHING INTO THE WESTERN NEBRASKA PANHANDLE BETWEEN 00-12Z THURS. EXCELLENT DEEP LAYER UPWARD MOTION IS DEPICTED LATE WED AFTN AND INTO THE EVENING OVER THE PLAINS OF SOUTHEAST WY...WHICH THEN SHIFTS INTO THE NEBRASKA PANHANDLE AFTER 06Z. THUS...STILL EXPECTING A WIDESPREAD HEAVY QPF EVENT FOR MUCH OF THE PLAINS. HPC HAS THE PANHANDLE IN A SLIGHT RISK FOR EXCEEDING FLASH FLOOD GUIDANCE. MUCH OF THE PRECIP WILL FALL AS RAIN OVER THE PLAINS...HOWEVER A TRANSITION TO SNOW COULD OCCUR AFTER AROUND 09Z FOR ELEVATIONS ABOVE 5000 FT OR SO. THE GFS HAS BEEN CONSISTENTLY THE WARMEST IN THE POST FRONTAL AIRMASS AS IT KEEPS SFC WET BULB TEMPS ABOVE 37F TO THE EAST OF THE LARAMIE RANGE THROUGH WED NIGHT...WHEREAS THE NAM IS CLOSE TO FREEZING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 320 PM MDT TUE MAY 6 2014 MEDIUM RANGE MODEL GUIDANCE IS IN EXCELLENT AGREEMENT WITH A POTENT UPPER-LEVEL SHORTWAVE AND ASSOCIATED SFC LOW EJECTING NORTHEAST INTO THE CENTRAL PLAINS EARLY IN THE PERIOD. BOTH THE GFS AND NAM SHOW A DISTINCT TROWAL FEATURE ON THE BACK SIDE OF THE LOW OVER THE WESTERN PANHANDLE. THIS COMBINED WITH GOOD QG ASCENT WILL MOST LIKELY YIELD A CONTINUATION OF MODERATE TO HEAVY PCPN FROM THE PANHANDLE INTO EAST CENTRAL WY BETWEEN 12-18Z THU. WITH 700-850 TEMPS BETWEEN 0 AND -5 C...WOULD EXPECT RAIN TO AT LEAST MIX WITH SNOW ESPECIALLY OVER THE HIGHER TERRAIN NEAR THE PINE RIDGE. NOT THINKING RATES WILL BE HIGH ENOUGH FOR SIGNIFICANT ACCUMULATIONS...BUT STILL CANNOT RULE OUT A FEW INCHES OF SNOW OVER OUR NORTHERN ZONES IN THE DEEPER COLD AIR. BEST FORCING AND MOISTURE SHIFTS NORTH AND EAST OF THE CWA BY EARLY AFTN...WITH PCPN CHANCES DIMINISHING THEREAFTER. QUASI-ZONAL FLOW ALOFT RETURNS TO THE AREA ON FRI AND SAT WITH A FEW NUISANCE DISTURBANCES EMBEDDED WITHIN. DESPITE SOME MODEST COOLING ALOFT FROM TIME TO TIME...WESTERLY DOWNSLOPE FLOW WILL GIVE WAY TO SEASONABLE TEMPS IN THE LOW TO MID 60S OVER THE PLAINS. COULD SEE A FEW SHOWERS OR RUMBLES OF THUNDER EACH AFTERNOON OVER MUCH OF THE AREA. GFS CAPES ARE GENERALLY LESS THAN 100 J/KG...BUT WITH STEEP MID LEVEL LAPSE RATES IN EXCESS OF 8.5 DEG C/KM...A STRAY LIGHTNING STRIKE CAN NEVER BE RULED OUT. BIG QUESTIONS COME INTO PLAY FOR THE SECOND HALF OF THE WEEKEND AND INTO EARLY NEXT WEEK. THE ECMWF REMAINS CONSISTENT WITH A CLOSED LOW AND TROUGH DIGGING INTO THE FOUR CORNERS WITH SFC CYCLOGENESIS OVER THE PLAINS OF EASTERN CO. LATEST GEM SHOWS A VERY SIMILAR FEATURE... SO THIS WILL BEAR WATCHING. 12Z GFS TELLS A DIFFERENT TALE...WITH A VERY PROGRESSIVE AND POSITIVELY TILTED OPEN WAVE MOVING QUICKLY ACROSS THE PLAINS. MADE VERY FEW CHANGES TO THE PREVIOUS FCST GIVEN THESE DIFFERENCES...BUT POTENTIAL EXISTS FOR ANOTHER MAJOR STORM LATE IN THE PERIOD IF THE ECMWF WERE TO VERIFY. SNOW WOULD AGAIN BE A GOOD POSSIBILITY AS H7 TEMPS PLUNGE AS LOW AS -10C. REGARDLESS OF WHICH MODEL IS CORRECT...COOLER AND BREEZY CONDITIONS SEEM TO BE A GOOD BET LATE IN THE WEEKEND. TRIMMED A FEW DEGREES OFF FCST HIGHS ON SUN AFTN AS WIDESPREAD CLOUD COVER AND COLD AIR ALOFT DO NOT LEND CREDENCE TO HIGHS NEAR 60F. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY EVENING) ISSUED AT 1108 PM MDT TUE MAY 6 2014 THE MAIN CONCERN WITH TAF ISSUANCE IS THE POTENTIAL FOR THUNDERSTORMS ALONG WITH IFR/MVFR CEILINGS DEVELOPING OVER THE PANHANDLE OVERNIGHT. THUNDERSTORMS WILL GENERALLY BE ISOLATED IN NATURE UNTIL 3AM OVER THE SOUTHERN AND CENTRAL PANHANDLE WITH ANOTHER CHANCE OF STRONG TO SEVERE TSTORMS ON WEDNESDAY EAST OF THE LARAMIE RANGE. OTHERWISE...LOW CIGS AND NEAR IFR CONDITIONS WILL BEGIN TO DEVELOP AROUND 08Z ACROSS THE NEBRASKA PANHANDLE DUE TO MOIST UPSLOPE FLOW...AND MAY PUSH INTO FAR SOUTHEAST WYOMING. PATCHY FOG IS ALSO POSSIBLE EARLY WEDNESDAY MORNING. && .FIRE WEATHER... ISSUED AT 320 PM MDT TUE MAY 6 2014 VERY DRY CONDITIONS EXIST TO THE WEST OF THE LARAMIE RANGE THIS AFTERNOON WITH RELATIVE HUMIDITY VALUES AT 10-15 PERCENT. SOUTHWEST WINDS ARE ALSO GUSTING TO 30 MPH. HOWEVER...FUELS ARE NOT SUPPORTIVE OF FIRE GROWTH WITH THE GREENUP IN PROGRESS. A STORM SYSTEM WILL MOVE ACROSS THE REGION ON WEDNESDAY AND WEDNESDAY NIGHT WITH AN EXCELLENT CHANCE OF WETTING PRECIPITATION...ESPECIALLY ALONG AND EAST OF THE LARAMIE RANGE. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...FINCH LONG TERM...HAMMER AVIATION...CLAYCOMB FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
500 AM MST WED MAY 7 2014 .UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS. && .SYNOPSIS... PACIFIC LOW PRESSURE WILL CONTINUE TO MOVE THROUGH THE REGION TODAY...BRINGING COOLER TEMPERATURES AND ANOTHER ROUND OF AFTERNOON BREEZES. WINDS ARE NOT EXPECTED AS STRONG AS THOSE OBSERVED TUESDAY...WITH ONLY ISOLATED GUSTS POSSIBLE IN THE AFTERNOON. FORECAST DAYTIME HIGHS WILL FALL WELL BELOW NORMAL AT MANY DESERT LOCATIONS THROUGH THURSDAY. DRY AND WARMER WEATHER IS ON TAP FRIDAY AND THROUGH THE WEEKEND AS HIGH TEMPERATURES CLIMB BACK INTO THE 90S ACROSS THE LOWER DESERTS. && .DISCUSSION... SHARPLY DEFINED PACIFIC TROUGH CONTINUES TO SLOWLY CIRCULATE INTO THE REGION...WITH THE TROUGH AXIS NEARING THE COLORADO RIVER VALLEY THIS MORNING. NEARLY CLEAR SKIES LEFT OVER THE WHOLE CWA IN THE WAKE OF THE VIGOROUS COLD FRONT PASSAGE TUESDAY. SOME EARLY EVENING/OVERNIGHT LIGHT SHOWER ACTIVITY CONTINUES NEAR THE COLD CORE OF THE TROUGH OVER SOUTHERN NEVADA AND TO A LESSER EXTENT SOUTHEAST CALIFORNIA...WITH MOST SITES ONLY REPORTING OVERCAST SKIES AND A HUNDREDTH OR TWO OF PRECIP ACROSS THE SOUTHERN NEVADA STATIONS. WATER VAPOR LOOP AND POTENTIAL VORTICITY MODEL OVERLAY PLOT A POCKET OF ENHANCED VORTICITY/SPIN COMING AROUND THE TROUGH BOTTOM AND ACROSS THE CA/INTL BORDER THIS MORNING. THIS VORT LOBE IS PROGGED THROUGH CENTRAL ARIZONA BY MIDDAY BEFORE QUICKLY DIFFUSING AND CLEARING EAST THIS EVENING. MOISTURE TRANSPORT AND PWATS NOT OVERLY FAVORABLE FOR SIGNIFICANT SHOWER ACTIVITY...WITH THE BEST PWATS OF NEAR HALF AN INCH OVER THE COLORADO RIVER VALLEY BY MIDDAY AND NOT EXTENDING MUCH FURTHER EAST. EVENING RUNS OF THE HI-RES HRRR AND ARW SHOW ANY SHOWER ACTIVITY DEVELOPING ACROSS NORTHERN ARIZONA THROUGH THE DAY AS THE TROUGH CONTINUES THROUGH THE AREA...WITH ONLY VERY SPOTTY DEVELOPMENT SKIRTING ACROSS THE NORTHERN PORTIONS OF MARICOPA AND GILA COUNTIES THROUGH THE AFTERNOON. SLIGHT CHANCE POPS WERE KEPT ACROSS THE HIGHER TERRAIN TO THE NORTH/EAST OF PHOENIX...WITH MENTION DROPPING OFF AFTER 08/03Z (8PM LOCAL) ONCE HEATING SUPPORT IS LOST WITH SUNSET. SIGNIFICANT COOLING OBSERVED BEHIND THE COLD FRONT...AS MUCH AS 10 DEGREES FROM THE SFC UP THROUGH 400MB VIA THE KVEF 00Z RAOB AND 6-8 DEGREES FROM KFGZ...WILL KEEP TEMPERATURES TODAY AND THURSDAY WELL BELOW SEASONAL NORMALS. LOOK FOR MID TO UPPER 70S ACROSS THE SOUTH- CENTRAL ARIZONA DESERTS WITH SLIGHTLY WARMER VALUES ACROSS THE WESTERN FORECAST AREA IN THE LOW 80S WEDNESDAY AND WIDESPREAD 80S AREAWIDE FOR THURSDAY UNDER MOSTLY CLEAR SKIES. BY FRIDAY...TROUGHING WILL HAVE MOSTLY CLEARED THE AREA WITH DRY WEST TO NORTHWESTERLY FLOW OVERTAKING THE REGION. TEMPERATURES WILL REBOUND BACK TOWARDS EARLY MAY NORMALS WITH LOW TO MID 90 DEGREE READINGS IN STORE FOR THE WEEKEND. ANOTHER LOW PRESSURE SYSTEM WILL DROP OUT OF THE PACIFIC NORTHWEST LATE SATURDAY INTO SUNDAY...BUT CURRENT THINKING FROM WPC AND THE BETTER PERFORMING OPERATIONAL/ENSEMBLE RUNS OF THE ECMWF KEEP THE BULK OF THE ENERGY AND ANY PRECIPITATION WELL TO OUR NORTH THROUGH MUCH OF THE GREAT BASIN STATES AND ONLY SKIRTING THE FAR NORTHERN PORTIONS OF ARIZONA. COULD SEE SOME ENHANCED BREEZINESS AS SOME GRADIENT TIGHTENING IS FORECAST...BUT VERY STRONG WINDS ARE NOT EXPECTED AT THIS TIME. 500MB HEIGHTS AND THICKNESSES WILL SEE SOME DECREASE...WHICH WILL KEEP DAYTIME TEMPERATURES FROM TAKING OFF TOO RAPIDLY FOR EARLY NEXT WEEK AND STAYING CLOSER TOWARDS NORMAL READINGS IN THE LOW TO MID 90S. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... UPPER LOW WILL CONTINUE TO MOVE EAST ACROSS THE AREA TODAY INTO TONIGHT. EXPECT SCT-BKN CU/SC DECKS TO DEVELOP ACROSS THE CENTRAL DESERTS LATER THIS MORNING...CONTINUING INTO THE AFTERNOON HOURS WITH BASES GENLY 8-10K FEET. NO PRECIP EXPECTED AT THE TAF SITES...ONLY ACROSS HIGHER ELEVATIONS NORTH/EAST OF PHOENIX. WINDS TO STAY MOSTLY OUT OF THE WEST THIS MORNING...INCREASING AND BECOMING LOCALLY GUSTY BY LATE MORNING OR EARLY AFTN. MAY SEE A FEW GUSTS TO 25KT OR SO BY AFTN. WINDS TO TAPER OFF AFTER SUNSET...SKIES TO BECOME MOSTLY CLEAR. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... UPPER LOW WILL CONTINUE TO MOVE EAST ACROSS THE AREA TODAY...BRINGING LOCALLY GUSTY WEST WINDS TO THE TAF SITES ALONG WITH FEW-SCT CUMULUS DECKS. THERE MAY BE SOME CIGS AROUND 8-10K THIS MORNING...WITH CLOUDS THINNING BY AFTERNOON AS SUBSIDENCE MOVES INTO AREA BEHIND A COLD FRONT. EXPECT SOME WIND GUSTS TO AT LEAST 25KT AT TIMES AT KIPL THIS AFTERNOON...A BIT LESS WIND AT KBLH. WINDS TO TAPER OFF AFTER SUNSET FOLLOWING LACK OF MIXING...AND SKIES TO BECOME GENLY CLEAR. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... FRIDAY THROUGH TUESDAY... DRY NORTHWEST FLOW ALOFT WILL SETTLE IN ACROSS THE AREA FRIDAY INTO THE WEEKEND...ALLOWING FOR A GRADUAL WARMING TREND WITH DESERT HIGHS CLIMBING INTO THE MID 90S BY SATURDAY. HUMIDITIES WILL BE ON THE LOW SIDE...RANGING FROM SINGLE DIGITS TO THE LOW TEENS EACH DAY. A WEATHER DISTURBANCE PASSING BY TO THE NORTH OVER THE WEEKEND WILL LEAD TO LOCALLY BREEZY CONDITIONS DURING THE AFTERNOON AND EVENING HOURS SATURDAY AND SUNDAY. EVEN HIGHER PRESSURE ALOFT WILL THEN BUILD BACK INTO THE DESERT SOUTHWEST EARLY NEXT WEEK FOR LIGHTER WIND...ALONG WITH WARMER AND DRIER CONDITIONS. BY NEXT TUESDAY EXPECT THE WARMER DESERTS TO EXCEED 100 DEGREES...AND MINIMUM HUMIDITIES TO FALL WELL BELOW 10 PERCENT OVER THE DRIER LOWER DESERT. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...NOLTE AVIATION....CB FIRE WEATHER...CB
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
425 AM PDT WED MAY 7 2014 .SYNOPSIS...A WEAK COLD FRONT WILL BRING A SLIGHT CHANCE OF LIGHT RAIN OR DRIZZLE TO THE AREA THURSDAY AND THURSDAY NIGHT. OTHERWISE DRY AND MILD WEATHER IS FORECAST THROUGH THE REMAINDER OF THE WEEK AND INTO THE UPCOMING WEEKEND. && .DISCUSSSION...AS OF 3:37 AM PDT WEDNESDAY...SATELLITE IMAGERY SHOWS MOSTLY CLEAR SKIES ACROSS THE NORTHERN PORTION OF THE DISTRICT WITH SOME AREAS OF STRATO-CU OVER THE EAST BAY...THE SAN FRANCISCO PENINSULA...AND AROUND THE MONTEREY BAY AND NORTHERN MONTEREY COUNTY. THE SURFACE PRESSURE GRADIENTS ARE MODERATE TO STRONG ONSHORE WITH 2.4 MB FROM SFO-SAC...AND STRONG NORTHERLY WITH 5.1 MB FROM ACV TO SFO. GRADIENTS ARE FORECAST TO TIGHTEN AGAIN THIS AFTERNOON FOR ENHANCED ONSHORE SEA BREEZES. HIGH TEMPERATURES ARE EXPECTED TO BE SIMILAR TO THOSE ON TUESDAY WITH 60S AND 70S MOST AREAS...80S IN THE WARMEST INTERIOR SECTIONS. ON THURSDAY A WEAK UPPER LEVEL SYSTEM WILL APPROACH THE PACIFIC NORTHWEST AND BRING THE POSSIBILITY FOR SOME LIGHT PRECIP ACROSS MAINLY THE NORTHERN PORTIONS OF THE DISTRICT LATE THURSDAY THROUGH THURSDAY NIGHT. CONFIDENCE IS LOW AS THE MAIN MOISTURE FIELD IS FORECAST TO BE WELL TO THE NORTH. IF RAIN DOES FALL...AMOUNTS WILL ALMOST CERTAINLY BE UNDER A TENTH OF AN INCH. THE UPPER LOW ASSOCIATED WITH THE THURSDAY SYSTEM IS FORECAST TO MOVE INTO THE PACIFIC NORTHWEST BY LATE FRIDAY NIGHT AND THEN INTO THE NORTHERN GREAT BASIN BY SATURDAY NIGHT. THIS COULD TIGHTEN THE SURFACE PRESSURE GRADIENTS TO RESULT IN GUSTY NORTHERLY WINDS IN OUR HILLS ON SATURDAY NIGHT AND SUNDAY MORNING. WARMER WEATHER IS EXPECTED BY SUNDAY AND INTO NEXT WEEK AS DRY NORTHERLY FLOW DEVELOPS AND AN UPPER RIDGE BEGINS TO DEVELOP NEAR THE COAST. && .AVIATION...AS OF 4:20 AM PDT WEDNESDAY...MAINLY VFR CONDITIONS WILL PREVAIL AFTER 16Z. MODERATE CONFIDENCE. ANOTHER DAY OF STRONG WEST TO NORTHWEST WINDS ARE IN STORE FOR THE REGION THIS AFTERNOON INTO THE EARLY EVENING HOURS. OTHERWISE...A STORM SYSTEM IS FORECAST TO MOVE SOUTH TOWARD THE REGION EARLY THURSDAY MORNING...BRINGING POSSIBLE MVFR CIGS AT THE VERY END OF THE FORECAST PERIOD. VICINITY OF KSFO...PATCHY LOW CLOUDS SURROUND THE BAY...WITH SFO ON THE EDGE OF CLOUDS. SCT CLOUDS MAY IMPACT THE TERMINAL THROUGH THE 16Z HOUR...LOW CONFIDENCE. OTHERWISE...WEST WINDS WILL INCREASE SIGNIFICANTLY THIS AFTERNOON...WITH WIND GUSTS TO 35 KT PROBABLE. KSFO BRIDGE APPROACH...PATCHES OF SCT LOW CLOUDS MAY IMPACT THE APPROACH THROUGH THE 16Z HOUR PREVENTING VISUALS. MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH AT LEAST THE 18Z HOUR...LOW CONFIDENCE. NUMERICAL GUIDANCE IS ALL OVER THE PLACE WITH CLEARING TIMES...FROM 15Z TO AN ALL DAY EVENT. THE MODELS ARE IN BETTER AGREEMENT THAT KSNS WILL SEE CLEARING BETWEEN 18Z AND 19Z...WHEREAS KMRY IS A BIT MORE PESSIMISTIC. THE HRRR AND LAMP INDICATE AN ALL DAY EVENT...SO WENT WITH A LATER CLEARING TIME OF 19Z. AGAIN LOW CONFIDENCE. && .MARINE...AS OF 02:40 AM PDT WEDNESDAY...MODERATE TO OCCASIONALLY STRONG WINDS WILL CONTINUE OVER THE WATERS THROUGH THIS EVENING AS SURFACE HIGH PRESSURE DOMINATES THE EASTERN PACIFIC. WINDS WILL SHIFT TO A WESTERLY DIRECTION ON THURSDAY MORNING AS A STORM SYSTEM CLIPS NORTHERN CA. OTHERWISE...HIGH PRESSURE WILL ONCE AGAIN SHIFT WINDS TO THE NORTHWEST AND CONTINUE INTO THE WEEKEND. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT ARENA TO PT REYES 0-10 NM SCA...PT REYES TO PIGEON PT 0-10 NM SCA...PIGEON PT TO PT PINOS 0-10 NM SCA...PT ARENA TO PT REYES 10-60 NM SCA...PT REYES TO PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PINOS 10-60 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...ROUGH BAR ADVISORY FOR SF BAR UNTIL 3 PM SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM SCA...SF BAY SOUTH OF THE BAY BRIDGE FROM 1 PM SCA...MONTEREY BAY FROM 1 PM && $$ PUBLIC FORECAST: SIMS AVIATION/MARINE: RILEY VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1042 AM EDT WED MAY 7 2014 .SYNOPSIS... A HIGH PRESSURE RIDGE OVER THE FORECAST AREA WILL EASE OFFSHORE LATER TODAY. A WARM FRONT OVER THE OHIO VALLEY AND CAROLINAS WILL SLOWLY MOVE NORTHEAST AND PASS THROUGH THE FORECAST AREA AROUND FRIDAY. A WEAK COLD FRONT IS FORECAST TO CROSS THE AREA LATE SATURDAY OR EARLY SUNDAY AND THEN STALL JUST SOUTH OF THE AREA. THIS FRONT IS THEN EXPECTED TO REVERSE COURSE AND START MOVING NORTHWARD THROUGH OUR REGION AGAIN ON MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A RIDGE OF HIGH PRESSURE ACROSS THE REGION WILL WEAKEN TODAY WHILE A WARM FRONT MOVES NORTH/EAST FROM THE OHIO VALLEY. AN AREA OF TSTMS ASSOC WITH A SHORT WAVE MOVING SE ACROSS WRN MD/S CENT PA WILL CONTINUE TO MOVE SE AS PER THE RECENT HRRR WHICH HAS A GOOD HANDLE ON IT. THESE SHOWERS WILL ARRIVE ACROSS THE DELMARVA AREAS EARLY THIS AFTERNOON...SO POPS ACROSS THESE AREAS HAVE BEEN INCREASED ON THE MOST RECENT ESTF. WE USED A BLEND OF MAV/MET MOS AND MOS GUIDE FOR DAYTIME HIGHS. WITH THE THICKENING CLOUD COVER DURING THE DAY, HIGHS ARE FORECAST TO BE A COUPLE OF DEGREES BELOW NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/... AS THE AFOREMENTIONED HIGH PRESSURE CONTINUES TO RECEDE AND SHIFT EASTWARD OFF THE COAST, THE WARM FRONT WILL PUSH CLOSER TO THE AREA OVERNIGHT. A COUPLE OF SHORT WAVE/VORT MAXES ARE FORECAST TO TRAVERSE THE AREA OVERNIGHT, WHICH COMBINED WITH THE AVAILABLE MOISTURE IS EXPECTED TO ENHANCE SHOWER ACTIVITY ACROSS THE AREA. THERE IS NOT MUCH INSTABILITY, BUT WE WILL KEEP THE CHANCE OF THUNDERSTORMS IN THE FORECAST FOR NOW AS THERE IS SOME WEAK ELEVATED INSTABILITY. ALSO, TOTAL TOTALS INCH UP TO THE MID-UPPER 40S AND K-INDEX VALUES CLIMB INTO THE MID-UPPER 20S. WE USED A BLEND OF MAV/MET MOS AND MOS GUIDE FOR OVERNIGHT LOWS WHICH KEEPS EVERYONE WITHIN A DEGREE OR TWO OF NORMAL. && .LONG TERM /THURSDAY THROUGH TUESDAY/... NEITHER DOMESTIC MODEL`S INITIALIZATION IN THE MIDWEST LOOKED THAT GRAND AND THE GFS IS ALREADY WAY TOO HOT WITH ITS QPF FIELDS IN ITS FIRST SIX HOURS. IF ANYTHING, THE GENERAL MODELING CONSENSUS HAS A SOUTHWARD BIAS ON ONGOING MIDWEST CONVECTION. FORECAST CONFIDENCE IS REDUCED BY WHAT LOOKS LIKE FEEDBACK VORT MAXES, ESPECIALLY ON THE GFS. WHETHER REALISTIC OR NOT, A DP/DT ON THEM THU AND FRI SHOW VERY LITTLE RUN TO RUN CONTINUITY. ADJUSTMENTS TO THE LONG TERM WILL BE A BLEND OF NON-GFS MODELS WITH WPC GUIDANCE AND CONTINUITY. GREATEST EMPHASIS ON POPS REMAINS EARLY THURSDAY AND SATURDAY. WE PREFER THE MORE NORTHERN MODELING SOLUTIONS TO START OUR HIGHEST PCPN CHANCES ON THURSDAY MORNING. AS THE MORNING AND AFTERNOON PROGRESSES, PCPN CHANCES ARE EXPECTED TO BE LESS AS THE TRIGGERING SHORT WAVE MOVES OFFSHORE AND FORECAST MOISTURE ABOVE 925MB DECREASES. FORECAST UNCERTAINTY WITH THE ONSHORE FLOW IS HOW MUCH CLEARING WILL OCCUR AS THERE WILL BE AN INVERSION. ONE WOULD THINK THAT THE MAY SUN WILL HAVE SOME EFFECT. LEAST CONFIDENCE THOUGH IS NORTHEAST WITH GREATEST CONFIDENCE OVER DELMARVA. WIDE RANGE IN MAX TEMPS ACROSS OUR CWA REFLECT THIS. WE DIDN`T CHANGE THEM MUCH FROM CONTINUITY. ANOTHER MID LEVEL WAA SURGE (SOME FGEN AND QVEC FORCING SHOWING UP IN THE FIELDS ALSO) IS FORECAST FOR THURSDAY NIGHT. THIS ONE HAS MORE ELEVATED CONVECTIVE INSTABILITY THAN TONIGHT, BUT RIGHT NOW IS NOT COUPLED WITH AN ATTENDANT SHORT WAVE. OVERALL WEAK FLOW ALOFT AND NO PREDICTED LLJ. POPS THUS WERE KEPT BLO LIKELY LEVELS. IN ADDITION, THE CONTINUING ONSHORE FLOW WITH DEW POINT TEMPERATURES RISING ABOVE THE WATER TEMPERATURES INCREASES THE CHANCES FOR MARINE FOG ADVECTING INLAND. WHILE POSSIBLE, WE MIGHT ALSO HAVE SOME DRIZZLE WHICH WOULD MAKE FOR AN OXYMORONIC METEOROLOGICAL PAIRING, DRIZZLE CAUSED BY THE STABLE TRAPPING OF MOISTURE BELOW THE FRONTAL INVERSION, BUT AN UNSTABLE AIR MASS ABOVE THE INVERSION CAPABLE OF TRIGGERING THUNDERSTORMS. ON FRIDAY, THE WARM FRONT IS PREDICTED TO MAKE MORE NORTHWARD PROGRESS AS THE 500MB RIDGE AXIS EASES TO THE EAST. RELATIVELY DRY AIR ONCE AGAIN IS PREDICTED TO PASS OVER OUR CWA, SO THE PCPN CHANCES ONCE AGAIN SHOULD DECREASE DURING THE MIDDLE OF THE DAY WITH A SLIGHT UPTICK IN CHANCES NORTHWEST LATE IN THE DAY. WHILE ON THURSDAY WE MIGHT BE TOO WARM WITH MAX TEMPS, FRIDAY WE MIGHT BE TOO LOW, ESPECIALLY DELMARVA. FRIDAY NIGHT WE INCREASE THE POPS AGAIN AS THE COLD FRONT APPROACHES. SATURDAY POTENTIALLY COULD HAVE STRONG THUNDERSTORMS AS THE COLD FRONT COMES CLOSER. THE FORECAST WIND FIELD (LLJ AND JET ALF COUPLET) SURE DO LOOK BETTER AND THE EFFECTIVE PREDICTED BULK SHEAR IS MORE ROBUST. THE LACK OF A LEE SIDE TROF FORMING BACKING THE WINDS FURTHER TO THE SOUTH WOULD BE THE LIMITING FACTOR TO COVERAGE. DONT BELIEVE CLOUDS OR TOO LOW TEMPS WILL BE THE WET BLANKET. FOR NOW, WE MAINTAIN INCREASINGLY HIGHER POPS WITH GREATEST CHANCES WEST. WE ARE DEEP IN THE SW FLOW BY SATURDAY, SO WE ARE PRETTY CONFIDENT WE WILL REACH OUR FORECAST MAX TEMPS. THE LATEST ECMWF AND GFS RUNS ARE MORE OPTIMISTIC ABOUT THE COLD FRONT CLEARING OUR CWA ON MOTHER`S DAY AND WE LOWERED POPS AND REMOVED THE MENTION OF THUNDER. THE AIR MASS BEHIND THE COLD FRONT IS NOT THAT MUCH COOLER, NOT MUCH OF A DROP OFF IN TEMPS. STILL ABOVE NORMAL. WHETHER ITS THE AFOREMENTIONED FRONT BACKING TO THE NORTH AGAIN, OR ANOTHER FRONT APPROACHING FROM THE WEST. BOTH INCREASE OUR CHANCES FOR SHOWERS AND THUNDERSTORMS ON MONDAY AND TUESDAY. TEMPERATURES THOUGH STILL LOOK PRETTY, PRETTY WARM FOR THE START OF THE WORK WEEK. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDITIONS ARE EXPECTED TO REMAIN ACROSS THE TAF SITES FOR TODAY INTO THE EARLY PART OF THE EVENING, ALTHOUGH CLOUDS WILL BE THICKENING AND LOWERING THROUGH THE DAY. THERE COULD BE SOME SCATTERED SHOWERS LATE IN THE DAY, BUT THEY ARE NOT EXPECTED TO REDUCE CIGS/VSBYS. AS WE GO INTO LATE EVENING HOURS AND INTO THE OVERNIGHT HOURS, CONDITIONS ARE EXPECTED TO LOWER TO MVFR, AND EVENTUALLY IFR AS AN AREA OF SHOWERS MOVES INTO THE AREA. THERE IS A SMALL CHANCE OF THUNDERSTORMS, BUT WE WILL KEEP THEM OUT OF THE TAFS FOR NOW SINCE CONFIDENCE IS NOT VERY HIGH ON THEM ACTUALLY OCCURRING. LIGHT WINDS EARLY THIS MORNING, MOSTLY FROM THE NORTHEAST, WILL BECOME MORE SOUTHEASTERLY OR SOUTHERLY THIS AFTERNOON. WINDS WILL SWITCH BACK TO THE SOUTHEAST THEN EAST LATER THIS EVENING AND OVERNIGHT. OUTLOOK... THURSDAY AND THURSDAY NIGHT...MVFR CONDITIONS AT TIMES DUE TO SHOWERS AND THUNDERSTORMS AS WELL AS LOWER CLOUDS AND FOG AT NIGHT. FRIDAY AND FRIDAY NIGHT...PRIMARILY VFR DURING THE DAY AND SOME MVFR CONDITIONS AT NIGHT. SATURDAY...OCCASIONALLY MVFR TO BRIEFLY IFR CONDITIONS IN SCATTERED SHOWERS AND THUNDERSTORMS. SUNDAY...PREDOMINATELY VFR. && .MARINE... SUB-ADVISORY CONDITIONS WILL PREVAIL ACROSS THE WATERS THROUGH TODAY AND TONIGHT AS HIGH PRESSURE THAT HAS BEEN OVER THE AREA RECEDES AND LIFTS TO THE NORTHEAST, ALTHOUGH WINDS MAY PERIODICALLY GUST AROUND 15-20 KNOTS. OUTLOOK... SUB SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED FOR THE NEXT SEVERAL DAYS. FOG MAY BE THE GREATER CONCERN, ESPECIALLY THURSDAY NIGHT WHEN THE SREF IS INDICATING A FOG BANK FORMING OVER OUR ATLANTIC WATERS. WITH A VEERING OF WINDS TOWARD THE SOUTH, THE CONCERN MAY MOVE OUT OF OUR AREA BY FRIDAY NIGHT. WE CONTINUE TO BE MORE CONSERVATIVE THAN WAVE WATCH SEAS WITH THE SW FLOW PRECEDING THE NEXT COLD FRONT ON THE WEEKEND AND THE POST FRONTAL SFC WINDS ARE RELATIVELY WEAK. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...AMC/GIGI NEAR TERM...ROBERTSON/PO SHORT TERM...ROBERTSON LONG TERM...GIGI AVIATION...AMC/GIGI/ROBERTSON MARINE...AMC/GIGI/ROBERTSON
AREA FORECAST DISCUSSION
NWS POCATELLO ID
900 AM MDT WED MAY 7 2014 .UPDATE...PRECIPITATION CONTINUES THIS MORNING WITH SNOW LEVELS RIGHT AROUND 5000 FEET. ACCUMULATIONS THUS FAR HAVE BEEN NO MORE THAN A DUSTING BUT STILL EXPECTING SNOW LEVELS TO RISE THROUGH THE DAY TODAY TO AROUND 7000 FEET. NAM AND HRRR BOTH ARE CONTINUING TO SHOW FAVORED CONVECTION IN THE SOUTH AND EAST HIGHLANDS WITH ISOLATED THUNDERSTORMS POSSIBLE. DEPENDING ON THE AMOUNT OF CLEARING IN THE CENTRAL MOUNTAINS...CONVECTION IS POSSIBLE IN THOSE AREAS AS WELL. WINDS NEAR AMERICAN FALLS RESERVOIR ARE STILL NORTHEAST AND STRONG ENOUGH TO SUPPORT THE LAKE WIND ADVISORY THAT IS IN EFFECT. STILL LOOKS LIKE A WIND SHIFT WILL HAPPEN EARLY AFTERNOON IN THAT AREA SO EXPIRING THE LAKE WIND AROUND 2 PM STILL LOOKS GOOD. ALL GRIDS STILL LOOK ON TRACK SO DID NOT MAKE ANY CHANGES. EP && .PREV DISCUSSION... /ISSUED 310 AM MDT WED MAY 7 2014/ SHORT TERM...TODAY THROUGH FRIDAY NIGHT. THE CURRENT SATELLITE IMAGERY WAS SHOWING AN UPPER LOW ROTATING INTO SW UTAH WHILE ASSOCIATED MOISTURE AND SHOWERS LIFTED NORTH INTO SE IDAHO. MODELS SUGGEST THAT THE UPPER LOW WILL LIFT NNE TODAY THROUGH UTAH LEAVING SE IDAHO UNDER A MOIST-UNSTABLE AIRMASS. AN INVERTED SURFACE LOW EXTENDING FROM COLORADO NE INTO SE IDAHO WILL SUPPORT NORTH WINDS THROUGHOUT THE UPPER VALLEY TODAY WHILE WEST WINDS SPREAD EAST THROUGH THE ERN MAGIC VALLEY. TOUGH CALL TODAY ON HOW LONG AND/OR HOW STRONG THE NORTH WINDS WILL BE ACROSS THE AMERICAN FALLS RESERVOIR. NEARBY OBS ARE CURRENTLY SHOWING NE WINDS NEAR ADVISORY LEVELS...THUS WILL PUSH A LAKE WIND ADV OUT THE DOOR WITH THE MORNING PACKAGE. THE LOW PASSES EAST OVERNIGHT WITH DRIER CONDITIONS SPREADING INTO THE REGION FROM THE WEST. A NEGATIVELY TILTED PAC TROUGH SWINGS INTO THE NW STATES THURSDAY AFTERNOON...SPREADING EAST ACROSS SRN IDAHO THURSDAY NIGHT/FRIDAY MORNING WITH ANOTHER ROUND OF WIDESPREAD PRECIPITATION AND BREEZY/WINDY CONDITIONS ANTICIPATED FOR SE IDAHO. HUSTON LONG TERM...SATURDAY THROUGH TUESDAY. THE 7/00Z RUN OF THE GFS HAS INCREASED THE WAVE AMPLITUDE AND OVERALL MOVED CLOSER IN LINE TO THE ECMWF WHICH TAKES A LOW NEAR THE OREGON COAST SATURDAY MORNING AND MOVES IT OVER UTAH BY SUNDAY MORNING. KEEPING CHANCE POPS IN THE MOUNTAINS SATURDAY AND SATURDAY NIGHT APPEARS TO BE A GOOD MOVE AND MAY NEED TO BE INCREASED SOME MORE. THAT LEAVES A HIGH PRESSURE RIDGE DEVELOPING NEAR THE WEST COAST BY SUNDAY AND DECREASING SHOWERS IN SOUTHEAST IDAHO SUNDAY EVENING. THE LATEST ECMWF IS NOT WITHOUT CHANGES. THERE ARE TWO MINOR DISTURBANCE CROSSING NORTHERN IDAHO...ONE MONDAY AND ANOTHER TUESDAY THAT RESULT IN A FLATTER RIDGE AND TAKING A LITTLE EDGE OFF THE WARM UP FOR EARLY NEXT WEEK. RS AVIATION...FOR KBYI...KPIH AND KIDA MORE SCATTERED RAIN SHOWERS ARE IN ORDER BETWEEN 10Z AND 19Z TODAY AS THE CIRCULATION IN NORTHWEST UTAH MOVES EAST TO NORTHEAST. THE INSTABILITY IS NOT AS STRONG AS YESTERDAY BUT CANT RULE OUT AN ISOLATED THUNDERSTORM IN THE CARIBOU HIGHLANDS AND BEAR LAKE AREA THIS AFTERNOON. MVFR CEILINGS WITH THE SHOWERS A GOOD BET. HIGH PRESSURE MOVES IN TONIGHT AND THURSDAY PROVIDING A BREAK IN THE WEATHER UNTIL A COLD FRONT COMES THROUGH FRIDAY MORNING. RS && .PIH WATCHES/WARNINGS/ADVISORIES... LAKE WIND ADVISORY UNTIL 2 PM MDT THIS AFTERNOON IDZ021. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
545 AM MDT WED MAY 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 225 AM MDT WED MAY 7 2014 EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW DEEPENING TROUGH CURRENTLY CENTERED OVER THE GREAT BASIN WITH SW FLOW EXTENDING ACROSS CENTRAL ROCKIES AND PLAINS. AT THE SURFACE LOW PRESSURE CURRENTLY EXTENDS FROM EASTCENTRAL COLORADO ACROSS THE TRI STATE REGION WITH A STATIONARY FRONT BISECTING THIS FEATURE GENERALLY ALONG AND SOUTH OF INTERSTATE 70. A DRY LINE EXTENDING ACROSS CENTRAL KS HAS BEEN BACKING UP TOWARDS THE EASTERN PART OF OUR CWA. PARTICULARLY LOW CONFIDENCE IN FORECAST FOR TODAY AS A RESULT OF THE LINGERING STATIONARY FRONT AND INCONSISTENCIES BETWEEN GUIDANCE ON EVOLUTION OF SURFACE LOW AND FRONT TIMING AS UPPER TROUGH SHIFTS EAST INTO THE PLAINS. THIS IS A REFLECTION OF MODEL DIFFERENCES ON EVOLUTION/TRACK OF CLOSED H5/H7 LOW CENTERS ACROSS THE PLAINS TODAY/TONIGHT. WE COULD SEE WIDE RANGING IMPACTS DEPENDING ON ALL OF THE ABOVE MENTIONED VARIANCES ON BOTH OUR RFW...A POSSIBLE WIND ADVISORY...AND POTENTIAL SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE NORTHERN HALF OF OUR CWA. THERE IS SO MUCH SPREAD BETWEEN MODELS FROM THE I-70 CORRIDOR NORTH ALL I WAS UNCOMFORTABLE DOING MORE THAN NUDGING TOWARDS THE LATEST BLENDS/NAM TRENDS. THIS PUTS THE SE HALF OF OUR CWA NEAR WIND ADVISORY CRITERIA...AND ANOTHER ROW OF COUNTIES WITHIN RFW CRITERIA. REGARDING THE CURRENT RFW AND POSSIBLE WIND ADVISORY...CONFIDENCE IS JUST TOO LOW TO MAKE HIGHLIGHT CHANGES. BASED ON EVOLUTION OF SURFACE FEATURES WE COULD SEE THUNDERSTORM INITIATION AND SEVERE POTENTIAL BY MIDDAY FURTHER SOUTH (I-70 CORRIDOR) BEFORE ANY PRIMARY THUNDERSTORM CHANCES TRANSITION NORTH AND WEST. WE WILL NEED TO MONITOR AND ADJUST AS CONFIDENCE INCREASE BASED ON REAL TIME DATA AND NEW RUNS OF SHORT RANGE GUIDANCE TO GET A BETTER HANDLE ON SENSIBLE WEATHER OVER OUR CWA THROUGH THIS EVENING. AS UPPER LOW TRANSITIONS EAST A COLD FRONT EVENTUALLY WILL PUSH SOUTH TONIGHT BEFORE STALLING ACROSS THE SOUTHERN PART OF OUR CWA. BESIDES COMPLICATING THE TEMP FORECAST...THIS FEATURE COULD ACT AS A FOCUS FOR ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT AS A SECONDARY SHORTWAVE TROUGH MOVES ACROSS THE NORTHERN PLAINS BEHIND THE INITIAL UPPER LOW. I USED A CONSENSUS BLEND OF TEMPS THROUGH FRI AND LINGERED POPS THROUGH FRI NIGHT TO ACCOUNT FOR LIFT/MOISTURE ALONG FRONT AND ASSOCIATE WITH WEAK TROUGH PASSAGE. WHILE TEMPS SHOULD RETURN TO NEAR SEASONAL VALUES...IT DOES LOOK LIKE WE HAVE POTENTIAL FOR LOW TEMPS TO DROP WELL BELOW NORMAL IN THE 30S...AND ACTUALLY WITHIN FROST ADVISORY CRITERIA. .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 215 AM MDT WED MAY 7 2014 WESTERLY ZONAL FLOW ALOFT WILL BE PRESENT ACROSS THE HIGH PLAINS SATURDAY...WHICH WILL BRING BENIGN CONDITIONS ACROSS THE FORECAST AREA. A POSITIVELY TILTED UPPER LEVEL TROUGH WILL BEGIN TO MOVE INTO THE GREAT BASIN REGION AND CONTINUE TO PROGRESS INTO THE TRI STATE AREA SATURDAY NIGHT. MODEL RUNS DIFFER AS TO THE LOCATION OF THE ENSUING TROUGH AS WELL AS THE TIMING OF THE PASSAGE OF THE TROUGH AXIS THROUGH THE REGION...BUT THIS WEATHER MAKING SYSTEM SHOULD AFFECT THE AREA SOMETIME BETWEEN THE SATURDAY NIGHT TO MONDAY NIGHT TIME FRAME. MOST MODEL FORECASTS INDICATE A SHORTWAVE RIDGE WILL MOVE INTO THE HIGH PLAINS ONCE THE TROUGH AXIS MOVES EASTWARD ON TUESDAY...BUT THE GEM MODEL HAS THE UPPER LEVEL LOW SYSTEM BECOMING CUT OFF OVER THE HIGH PLAINS REGION. TENDED TO SIDE WITH THE DRY FORECAST AS THE ECMWF...GFS AND DGEX FORECASTS INDICATE THE RIDGE. THE MAIN CONCERN FOR THE LONG TERM FORECAST PERIOD WILL BE THE CHANCES FOR THUNDERSTORMS SATURDAY NIGHT THROUGH MONDAY. THUNDERSTORMS AND PRECIPITATION CHANCES MAY LINGER INTO TUESDAY IF THE FLOW ALOFT BECOMES CUT OFF...WHICH WILL AID IN MORE PRECIPITATION PRODUCTION. LATEST MODEL FORECASTS PLACE THE GREATEST MID AND LOWER LEVEL JET SPEEDS AND HIGHEST AREAS OF INSTABILITY WELL TO THE EAST OF THE FORECAST AREA FOR THE PERIOD FOR GREATEST PRECIPITATION POTENTIAL...SO THUNDERSTORM ACTIVITY IS NOT EXPECTED TO BECOME SEVERE. DUE TO THE ZONAL FLOW PATTERN SATURDAY FOLLOWED BY A PUSH OF COOLER AIR ALOFT WITH THE TROUGH PATTERN...TEMPERATURES THROUGH THE LONG TERM PERIOD WILL BE NEAR TO SLIGHTLY BELOW NORMAL WITH HIGHS GENERALLY IN THE MID 60S TO LOWER 70S. LOW TEMPERATURES WILL SPAN DURING THIS PERIOD BETWEEN THE LOW TO UPPER 40S...WITH SOME SPOTS IN EASTERN COLORADO DIPPING INTO THE UPPER 30S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 545 AM MDT WED MAY 7 2014 EARLY IN THE TAF PERIODS LOW LEVEL MOISTURE POOLING NORTH OF STATIONARY FRONT WILL LEAD TO VIS VARYING FROM 4-7SM OVER NW KS AND SW NE THROUGH ABOUT 15Z. NOT CONFIDENT ENOUGH TO PUT MVFR VIS IN TAF...SO LIMITED VIS RESTRICTION TO 6SM AS THIS LIGHT FOG IS FAIRLY PATCHY. AS FRONT LIFTS NORTH TODAY AND SURFACE LOW DEEPENS GUSTY SOUTH WINDS WILL DEVELOP WITH GUSTS TO 30KT AT KGLD AND AROUND 20-25KT AT MCK. A LOT OF SPREAD ON GUIDANCE ON TIMING OF THIS FRONT AND A POTENTIAL COLD FRONT TONIGHT. FOR NOW SHOWED WIND SHIFT TO W-NW TONIGHT AT BOTH TERMINALS BASED ON LATEST NAM/RAP. WITH SLOWER WARM FRONT IT LOOKS LIKE A FEW THUNDERSTORMS COULD DEVELOP AROUND BOTH TERMINALS...HOWEVER AT THIS TIME CONFIDENCE WAS TOO LOW IN INITIATION OR COVERAGE TO ADD MENTION TO TAFS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING FROM 11 AM MDT /NOON CDT/ THIS MORNING TO 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ013>016-027>029-041-042. CO...RED FLAG WARNING FROM 11 AM THIS MORNING TO 9 PM MDT THIS EVENING FOR COZ253-254. NE...NONE. && $$ SHORT TERM...DR LONG TERM...MK AVIATION...DR
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
943 AM EDT WED MAY 7 2014 .SYNOPSIS... A FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS NORTH CAROLINA TODAY. THE FRONT LIFTS NORTH AS A WARM FRONT TONIGHT INTO THURSDAY MORNING. HIGH PRESSURE WILL BECOME ANCHORED OFF THE SOUTHEAST COAST THURSDAY AFTERNOON THROUGH FRIDAY...AS THE FRONTAL BOUNDARY LINGERS ALONG THE MID ATLANTIC COAST. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MID-MORNING WX ANALYSIS FEATURES ~1024MB SFC HIGH PRESSURE OVER JAMES BAY NOSING SOUTH INTO THE NORTHEAST/MID-ATLANTIC REGION, WITH A QUASI-STATIONARY FRONTAL BOUNDARY DRAPED WELL SOUTH INTO THE CAROLINAS. ALOFT, WV/IR IMAGERY SHOWING UPPER LEVEL RIDGE AXIS EXTENDING FROM THE SOUTHEAST INTO THE TN RVR VALLEY THIS MORNING...WITH A DEEP TROUGH IN PLACE OVER THE INTERMOUNTAIN WEST, AND A SECOND DEPARTING TROUGH OVER ATLANTIC CANADA. CONTINUING TO SEE SOME CLUSTERS OF CONVECTIVE SHRAS/ISO T IN ASSOCIATION WITH SHORTWAVE ENERGY EJECTING FROM THE TROUGH OVER THE WEST. THIS ACTIVITY IS EXPECTED TO RIDE THE NW FLOW PATTERN ALOFT FROM W PA INTO THE MID ATLANTIC REGION BY THIS AFTN. WHILE DYNAMICS ARE LESS THAN FAVORABLE FOR ANY SIGNIFICANT/WIDESPREAD TSTM DEVELOPMENT (DIMINISHING EFFECTIVE SHEAR/PERSISTENT MID- LEVEL CAPPING/MODEST MLCAPE <500 J/KG), EXPECT SOME SCT SHRAS WL MAKE IT ACROSS AS WEAKENING VORTMAX SWINGS ACROSS THE MASON-DIXON LINE THROUGH THIS AFTN. LATEST HRRR SEEMS TO BE PERFORMING WELL ALONGSIDE LATEST SAT/RADAR TRENDS, AND HV THEREFORE INSTALLED SOME CHC/"SCT" POPS FOR EASTERN SHORE COUNTIES AND FAR NE VA NORTHERN NECK COUNTIES, MAINLY ALONG AND NORTH OF US-360. OTEHRWISE, EXPECT A DRY DAY FOR MOST OF THE AREA, WITH LITTLE OR NO FOCUS FOR ADDITIONAL CONVECTIVE DEVELOPMENT. DEVELOPING SW FLOW OVER THE SOUTHERN PLAINS AND SOUTHEAST SHOULD ALLOW THE STATIONARY FRONT TO SHIFT BACK TO THE NORTH THIS AFTN/TNGT AS A WARM FRONT, WITH MID-HIGH CLOUDS MOVING FROM SW-NE THROUGH THE DAY. HOWEVER, THE FRONT SHOULD REMAIN S OF THE LOCAL AREA THROUGH 00Z/8P EDT. HIGHS SHOULD RANGE FROM THE UPPER 60S TO AROUND 70 OVER THE EASTERN SHORE...TO THE MID/UPPER 70S FROM INTERIOR NE NC TO CENTRAL VA. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... THE STATIONARY FRONT LIFTS NNE LATE TONIGHT INTO THURSDAY MORNING THROUGH MOST OF THE AREA...BEFORE STALLING IN VICINITY OF THE LOWER MD EASTERN SHORE. A SECOND, MORE DEFINED SHORTWAVE TROUGH TRACKS THROUGH THE NW FLOW TONIGHT INTO EARLY THURSDAY. THE BEST POTENTIAL FOR SHOWERS/TSTMS WILL BE OVER PA/NJ/NRN DE/FAR NE MD. HOWEVER...PORTIONS OF THE LOCAL AREA (EASTERN SHORE AND NRN NECK) ARE CLOSE ENOUGH TO THE MID-LEVEL FORCING TO INCLUDED A 20-30% POP. THUNDER WILL BE INCLUDED BASED ON UPSTREAM ACTIVITY...MODESTLY STEEP MID-LEVEL LAPSE RATES...AND THETA-E RIDGING EXTENDING N FROM THE SUBTROPICAL WRN ATLANTIC. CLOUDS SHOULD GRADUALLY DECREASE FROM SW-NE THURSDAY...BUT THE LOWER MD EASTERN SHORE COULD REMAIN MOSTLY CLOUDY THROUGH THE DAY. THURSDAY HAS THE POTENTIAL TO BE THE WARMEST DAY OF THE YEAR SO FAR W OF THE BAY...WITH HIGHS RANGING FROM THE MID 80S TO AROUND 90. HIGHS OVER THE EASTERN SHORE SHOULD RANGE FROM THE LOW/MID 70S ALONG THE IMMEDIATE ATLANTIC COAST...TO THE UPPER 70S/AROUND 80 INLAND. THE FRONT MAY ACTUALLY DROP BACK S INTO THE EASTERN SHORE AS A BACKDOOR COLD FRONT THURSDAY NIGHT INTO EARLY FRIDAY...BEFORE RETREATING NNE FRIDAY AFTERNOON. THIS WILL MAKE FOR A CHALLENGING TEMPERATURE/SKY COVER FORECAST. NAM/GFS BUFR AT SBY SOUNDINGS SUGGEST SOME STRATUS COULD COME INLAND FROM THE OCEAN. THIS AND THE ULTIMATE PLACEMENT OF THE FRONT WILL HAVE A LARGE INFLUENCE ON HIGHS FRIDAY. THE CURRENT FORECAST IS FOR HIGHS AROUND 70 ALONG THE COAST...TO MID/UPPER 70S FOR INTERIOR PORTIONS. ELSEWHERE...EXPECT A SUNNY AND WARM DAY WITH HIGHS IN THE MID/UPPER 80S (LOCALLY LOW 80S COASTAL SE VA/NE NC). && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... BERMUDA HIGH PRESSURE REMAINS ANCHORED OFF THE SERN COAST THROUGH THE WEEKEND. LATEST MODEL DATA SLOWS THE APPRCH OF NEXT FRNT ACROSS THE MTS UNTIL SUNDAY. KEPT FRI NIGHT/SAT MORNING DRY. SCT CONVECTION PSBL INVOF LEE TROF RESULTING IN DIURNAL POPS SAT AFTN/EVE. LOWS FRI NIGHT L-M60S. HIGHS SAT 80-85...XCPT M-U70S COASTAL AREAS. FRONT APPRCHS THE AREA SAT NIGHT THEN WEAKENS/WASHES OUT ACROSS THE MID ATLNTC RGN SUNDAY. HOWEVER...MODELS NOW WANT TO KEEP THIS WEAKEN BNDRY/TROF HANGING ARND THE RGN THROUGH ERLY NEXT WEEK. GIVEN THIS TRIGGER...KEPT CHC SHWRS/TSTMS (20-40%...HIGHEST W OF BAY) IN FCST THROUGH THE PRD. HIGHS EACH DAY 80-85 EXCEPT REMAINING IN THE 70S COASTAL SECTIONS. LOWS U50S-M60S. && .AVIATION /13Z WEDNESDAY THROUGH SUNDAY/... STALLED FRONTAL BOUNDARY REMAINS DRAPED OVER THE CAROLINAS AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. A WEAK WAVE IN NWLY FLOW ALOFT IS PRODUCING BKN-OVC SKIES WITH DECKS GENERALLY 6-10K FT AGL EARLY THIS MORNING. OTHERWISE...WINDS GENERALLY CALM- LESS THAN 5 KT. FOR TODAY...VFR CONDITIONS PREVAIL AS HIGH PRESSURE BUILDS OFFSHORE. ADDITIONAL UPPER LEVEL WAVE WILL KEEP SCT-BKN MID LEVEL CLOUDS AROUND...WITH SOME SCT-BKN LOWER MID-LEVEL CLOUDS (3-5K FT AGL) OVER SE VA/NE NC. SE WINDS REMAIN GENERALLY AOB 10 KT. FRONTAL BOUNDARY WILL BEGIN TO LIFT NWD TONIGHT AS A WARM FRONT...WITH SOME STRATUS POSSIBLE. HOWEVER...MOISTURE RETURN WILL BE LIMITED...SO DO NOT ANTICIPATE WIDESPREAD STRATUS. THEREAFTER...VFR CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK. THERE IS A SLIGHT TO LOW END CHANCE OF SHOWERS/THUNDERSTORMS OVER THE MD ERN SHORE...INCLUDING KSBY TONIGHT AND THURSDAY. BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS ARE IN PLACE SUNDAY. && .MARINE... STALLED FRONTAL BOUNDARY REMAINS DRAPED OVER THE CAROLINAS AS HIGH PRESSURE OVER SE CANADA RIDGES SWD OVER THE WATERS. THE RESULT IS LIGHT SELY FLOW AOB 10 KT OVER THE WATERS WITH WAVES AND SEAS GENERALLY 1-2 FT. HIGH PRESSURE LOCATES JUST OFF THE MID-ATLANTIC COAST THIS AFTERNOON AS THE STALLED FRONTAL BOUNDARY BEGINS TO LIFT NWD AS A WARM FRONT. AS THIS OCCURS...A WEAK WAVE OF LOW PRESSURE WILL LIFT ALONG THE FRONT...RESULTING IN A STRENGTHENING PRESSURE GRADIENT OVER THE WATERS. WINDS ALOFT WILL INCREASE TO 20-25 KT...BUT COOL WATERS AND WARM TEMPS ALOFT WILL RESULT IN AN INVERSION OVER THE WATERS...PREVENTING THE STRONGER WINDS FROM MIXING TO THE WATER. HOWEVER...ENOUGH OF A SFC PRESSURE GRADIENT WILL RESULT IN WINDS AROUND 15 KT OVER THE BAY LATE TODAY INTO EARLY TONIGHT BEFORE DIMINISHING AFTER MIDNIGHT. A FEW GUSTS UP TO 18-20 KT ARE POSSIBLE...BUT SCA CONDITIONS ARE NOT ANTICIPATED. WARM FRONT LIFTS OVER THE WATERS TONIGHT INTO THURS...WITH FLOW BECOMING S-SW BEHIND THE FRONT. SW FLOW PREVAILS THRU THE WEEKEND AS HIGH PRESSURE ANCHORS OVER THE WRN ATLANTIC...RESULTING IN ONGOING SUB-SCA CONDITIONS. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...AJZ NEAR TERM...AJZ/MAM SHORT TERM...AJZ LONG TERM...MPR AVIATION...SAM MARINE...SAM
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
703 AM CDT WED MAY 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 434 AM CDT WED MAY 7 2014 SURFACE WARM FRONT THIS MORNING WAS JUST CROSSING THE BORDER FROM MO INTO IA AND IS ASSOCIATED WITH A 995 MB SFC LOW IN THE VICINITY OF CO/KS/NEB. THERE ARE A COUPLE OF BANDS OF STORMS OUT THERE THIS MORNING. ONE EXTENDS FROM CLEVELAND BACK TO GREEN BAY THAT YOU CAN FOLLOW BACK TO SHOWERS IN THE DULUTH AREA AND ASSOCIATED WITH THE ARRIVAL OF THE ELEVATED CAPE. AT THE NOSE OF THE LLJ AND EDGE OF THE CAPPING INVERSION /WHERE H7 TEMPS EXCEED +9C/ YOU WILL FIND A BROKEN LINE OF STORMS ALONG THE MN/IA. MPXWRF AND SPCWRF PRETTY MUCH NAILED THESE STORMS...SO FOLLOWED THE TREND OF THESE MODELS FOR WORKING HIGHER POPS SOUTH OF A MANKATO/RED WING/CHIP FALLS LINE THROUGH THE MORNING. GIVEN THE RAPS DEPICTION OF THE LLJ VEERING MORE EASTERLY THROUGH THE MORNING WITH LITTLE DEVELOPMENT NORTH...IT MAKES SENSE THAT THESE STORMS WILL NOT BUILD MUCH FARTHER NORTH OF THEIR CURRENT LATITUDE AND WILL INSTEAD HEAD MORE OR LESS DOWN I-90 INTO CENTRAL WI WITH THE LLJ. NOT EXPECTING MUCH SEVERE POTENTIAL OUT OF THESE...BUT WITH EFFECTIVE SHEAR UP NEAR 30 KTS AND CAPE BETWEEN -10C AND -30C /HAIL CAPE/ UP AROUND 500 J/KG...WE WILL LIKELY CONTINUE TO SEE THE OCCASIONAL STORM PUT OUT HAIL THAT GETS UP IN THE 1 INCH TERRITORY OR SLIGHTLY LARGER. BEHIND THIS MORNING ACTIVITY...H7 TEMPS WILL PUSH UP TO BETWEEN 8 AND 10C...WITH A VERY DRY PLUME OF AIR COMING IN IN THE H7-H5 LEVEL AS WELL. THIS WILL LIKELY KEEP THE MPX AREA CAPPED AND DRY MUCH OF THE DAY AS WE WATCH THE WARM FRONT LIFT NORTH ACROSS IOWA. BY PEAK HEATING...THIS WARM FRONT LOOKS TO BE UP NEAR I-90. WARM SECTOR COMING UP WITH THIS FRONT IS THE SAME AIRMASS THAT HAS SPENT THE LAST THREE DAYS BREAKING RECORD HIGHS ACROSS TX/OK/KS...SO IT WILL BE WARM TO SAY THE LEAST...WITH HIGHS IN THE 90S LIKELY CLEAR UP TO THE I-80 CORRIDOR. THIS WARM FRONT STILL MAKES FOR A DIFFICULT FORECAST AS OVERCAST CONDITIONS TO THE NORTH OF THE FRONT WILL HOLD HIGHS BACK IN THE 50S/60S...WHILE SOUTH OF THE BOUNDARY IT WILL BE FEELING LIKE SUMMER. CONTINUED TO FAVOR THIS FORECAST TOWARD THE ECMWF...WHICH HAS MID 80S ALONG I-90 THAT FALL BACK TO THE UPPER 50S/LOWER 60S NORTH OF I-94. WE WILL HAVE TO WATCH THOSE TEMPS THOUGH. THERE IS VIRTUALLY NO CLOUD COVER ACROSS IOWA RIGHT NOW...AND IF THIS TREND CONTINUES OVER US THIS AFTERNOON...THEN SOMETHING MUCH CLOSER TO WHAT THE RAP HAS BEEN SHOWING ALL MORNING IS POSSIBLE...WHICH IS LOWER 90S COMING UP AS FAR NORTH AS MANKATO/REDWOOD FALLS...WITH HIGHS CLOSER TO 80 IN THE CITIES...WITH EVEN THE COLDER AREAS AROUND LADYSMITH PUSHING 70. MAIN QUESTION FOR THIS EVENING/TONIGHT IS WHEN DOES THE CAP BREAK. ONCE IT DOES...IT IS LOOKING LIKE A VERY ACTIVE NIGHT ACROSS THE MPX CWA. THROUGH THE AFTERNOON...ANY ACTIVITY LOOKS TO REMAIN TO THE NW OF THE CAP...WHICH WOULD KEEP THE BULK OF THE ACTIVITY TODAY OUT FROM CENTRAL SODAK INTO NW MN. EVENTUALLY...A STRENGTHENING LLJ AND THE APPROACH OF THE MAIN UPPER TROUGH WILL START TO ERODE THE CAP. GENERALLY FOLLOWED THE IDEA OF THE SPCWRF AND THE NMM/ARW WITH ACTIVITY TAKING OFF BETWEEN 2Z AND 4Z. GIVEN THE DEGREE OF INSTABILITY EXPECTED AND EFFECTIVE SHEARS UP AROUND 50 KTS...IT IS VERY LIKELY THAT THESE STORMS WILL BE ABLE TO PRODUCE LARGE HAIL...SO THE DAY1 SLIGHT RISK IS MORE THAN WARRANTED. ALTHOUGH NO CONVECTION IS CURRENTLY ANTICIPATED IN THE AFTERNOON...IF WE WERE TO SEE SOMETHING GO IT WOULD HAVE A HIGH LIKELIHOOD OF BEING SEVERE...WITH A TORNADO THREAT IF IT IS CLOSE TO THE WARM FRONT. HOWEVER...THE WARM/DRY LAYER NOTED EARLIER AROUND H7 WILL MOST LIKELY KEEP ANYTHING FROM GOING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 434 AM CDT WED MAY 7 2014 THE EXTENDED PERIOD WILL BE AN ACTIVE ONE WITH ONLY ONE DRY PERIOD FORECAST AND THAT IS FRIDAY NIGHT. THURSDAY IS THE DAY OF INTEREST. ALL INDICATIONS ARE FOR LOW PRESSURE OVER EASTERN NEBRASKA THURSDAY MORNING TO SLOWLY DEEPEN WHILE MOVING INTO SOUTHWEST MINNESOTA DURING THE AFTERNOON AND INTO CENTRAL MINNESOTA DURING THE EVENING. CONVECTION IS ANTICIPATED TO BE ONGOING THURSDAY MORNING ACROSS CENTRAL MN AND WEST CENTRAL WI. THIS WILL MOVE NORTHEAST EARLY ON ALLOWING FOR THE DESTABILIZATION TO COMMENCE. PROJECTIONS FOR THE AFTERNOON AND EVENING HOURS ARE FOR 0-1KM SHEAR TO BE IN THE 25-35 KNOT RANGE AHEAD OF THE LOW AND COLD FRONT WITH 0-6KM SHEAR IN THE 40-50 KNOT RANGE. EASTERN MN AND WESTERN WI ARE ALSO IN A FAVORABLE COUPLED JET ALOFT WITH 100 KNOT RIGHT ENTRANCE REGION OVER NORTHERN MN WHILE A 100+ KNOT JET SURGES INTO EASTERN IA DURING THE AFTERNOON. THE DIFFERENTIAL DIVERGENCE IS QUITE STRONG BY EVENING ACROSS THE TWIN CITIES. ALSO...VARIOUS SOLUTIONS ARE POINTING TO 0-3KM CAPE REACHING 100-150 J/KG BY LATE IN THE AFTERNOON...AGAIN CLOSE TO THE TWIN CITIES. HENCE...A SEVERE AFTERNOON AND EVENING IS LOOKING MORE AND MORE LIKELY WITH ALL FORMS OF SEVERE WEATHER POSSIBLE INCLUDING A FEW TORNADOES. THE SEVERE THREAT SHOULD BE OVER BY MIDNIGHT ACROSS WESTERN WI AS THE ATTENDANT COLD FRONT MOVES THROUGH. HIGHS ON THURSDAY HAVE POTENTIAL TO RUN INTO THE 80S FROM THE TWIN CITIES ON SOUTH AND SOUTHWEST. BLENDED GUIDANCE KEPT HIGHS IN THE UPPER 70S. A FEW SHOWERS MAY LINGER OVER NORTHERN AND EASTERN AREAS OF THE FA ON FRIDAY UNDER THE COLD UPPER TROUGH. AS MENTIONED EARLIER...FRIDAY NIGHT IS THE ONLY DRY PERIOD AS A WEAK RIDGE OF HIGH PRESSURE MOVES THROUGH. THE PATTERN STARTS TO BECOME MORE ACTIVE AGAIN ON SATURDAY AS NORTHERN AND SOUTHERN STREAM ENERGY BEGIN TO INFLUENCE THE WESTERN HALF OF THE CONUS. THIS DEVELOPS ANOTHER WAVE OF LOW PRESSURE TO OUR SOUTHWEST WITH SHOWER CHANCES INCREASING THROUGH THE WEEKEND AND EARLY NEXT WEEK. SOME SIGNIFICANT DIFFERENCES EXIST BETWEEN THE GFS AND EC BY EARLY NEXT WEEK ON THE LOCATION OF THE SURFACE LOW. THE GFS WOULD BE FLATTER AND FURTHER EAST WITH THE LOW WHILE THE EC IS MORE ROBUST WITH THE UPPER TROUGH AND SURFACE LOW. THIS WILL NEED TO BE WATCHED AS WE COULD BE CLOSE TO THE WARM SECTOR ALONG WITH A SEVERE WEATHER THREAT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 649 AM CDT WED MAY 7 2014 BIGGEST THING TO SAY FIRST IS THE GFSLAMP WAS IGNORED IN TERMS OF ITS CIG FORECAST. THE WARM FRONT IS MAKING ITS WAY NORTH ACROSS IOWA...HOWEVER THERE ARE VIRTUALLY NO CLOUDS BELOW 12K FEET IN IOWA...SO FIND IT HARD TO BELIEVE THE VERY PESSIMISTIC LAMP FORECASTS. INSTEAD CONTINUED TO FOLLOW THE IDEA OF THE NAM...WITH CIGS NOT REALLY LOWERING MUCH UNTIL A LOCATION GETS CLOSER TO THE WARM FRONT. AND EVEN THEN...THE HRRR/RAP SAY WE WILL NOT SEE MUCH IN THE WAY OF STRATUS ANYWAYS...SO CONTINUED THE TREND OF BACKING OFF ON THE MVFR MENTION. HI-RES MODELS CONTINUE TO SHOW TSRA DEVELOPING IN THE VCNTY OF RWF BETWEEN 00Z AND 03Z...THEN RAPIDLY EXPANDING ACROSS THE AREA AFTER 3Z AS THE WARM FRONT LIFTS NORTH. COULD BE SEVERAL HOURS OF SHRA/TSRA ACTIVITY FOR STC/AXN ONCE THINGS GO. THIS IS ALSO THE PERIOD WHEN LOWER CIGS WOULD BE MOST LIKELY...BUT EVEN THEN WE MAY STAY PREDOMINATELY VFR. KMSP...STORMS WILL STAY WELL SOUTH OF THE FIELD THIS MORNING...AND ATMOSPHERE WILL REMAIN CAPPED TO KEEP THE FIELD DRY UNTIL LIKELY BETWEEN 2Z AND 4Z. CONFIDENCE HIGH IN TSRA IMPACTING THE FIELD TONIGHT...BUT A BIT LOWER ON EXACT TIMING. DO FEEL WARM FRONT WILL HAVE LIFTED FAR ENOUGH THOUGH BY 12Z THU THAT MSP SHOULD BE DONE WITH THE OVERNIGHT ACTIVITY BY THEN. AS FOR CIGS...BEGINNING TO LOSE CONFIDENCE THAT WE WILL SEE MUCH IN THE WAY OF RESTRICTIONS AT ALL OUTSIDE OF PRECIP...SO CONTINUED TO TREND TOWARD KEEPING CIGS HIGHER. /OUTLOOK FOR KMSP/ THU...VFR EARLY WITH IFR/TSRA LIKELY IN THE AFTERNOON. SOME STORMS MAY BE SEVERE. WINDS SE BECOMING S AT 10G20KTS. FRI...MVFR EARLY...THEN VFR. WINDS W AT 10G20KTS. SAT...VFR. WINDS S 5-10KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...RAH AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
633 AM CDT WED MAY 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM CDT WED MAY 7 2014 ISOLATED ELEVATED STRONG TO SEVERE THUNDERSTORMS ARE ONGOING THIS MORNING. THE HRRR AND RAP REALLY ARE NOT HANDLING THE STORM TRACK AS THESE METEOROLOGICAL CHALLENGED MODELS PREFER TO TRACK THE ACTIVITY MORE NORTHEAST THROUGH NORTHWEST NEB VS THE WRN SANDHILLS. THIS LIKELY A RESULT OF THE STORM(S) BECOMING ROOTED IN THE LOW LEVEL EASTERLIES. AT ANY RATE THE CURRENT THINKING IS THE STORMS WILL EITHER WEAKEN BEFORE 12Z OR CONTINUE TRACKING TOWARD SCNTL SD. A BLEND OF THE NAM...RAP...ECM...SREF AND THE PREVIOUS FORECAST SUGGESTED SCATTERED POPS THIS MORNING BECOMING LIKELY THIS AFTERNOON. THE RAP HAS ANALYZED A CLOSED H700MB LOW OVER NORTHEAST COLO AT 07Z WHICH LIFTS NORTHEAST THROUGH NWRN NEB THIS MORNING TO FOLLOWED BY A SECOND AND THIRD H7 WAVES THIS AFTERNOON AND EARLY THIS EVENING. THIS WOULD LIKELY KEEP THE WARM SECTOR FROM KIML TO KONL AND SOUTH DRY TODAY. THE NAM SUGGESTS SOME CONVECTION COULD DEVELOP OFF THE FRONT RANGE THIS AFTN AND SWEEP NORTHEAST THROUGH THE SRN AND NERN ZONES. THE THREAT OF SEVERE WEATHER IS OBVIOUS WITH BULK SHEAR 50 KTS OR GREATER AND STEEPENING LAPSE RATES WITH THE APPROACHING 4 CORNERS LOW. SPC HATCHED AN EGG OF VERY LARGE HAIL ACROSS THE WRN SANDHILLS AND PANHANDLE. THIS IS ALONG AND NORTH OF SFC FRONT WHICH IS EXPECTED TO LIFT THROUGH SRN AND NERN NEB LATE THIS AFTN. VERY LARGE HAIL IS POSSIBLE WITH STORMS THIS AFTERNOON AND EVENING AND MOST IF NOT ALL OF THIS SHOULD BE IN THE COLD AIR NORTH OF THE SFC FRONT. THE 5 PERCENT TORNADO AND 15 PERCENT WIND PROBABILITIES WOULD APPEAR CONDITIONALLY TIED TO STORMS FORMING ALONG THE SFC FRONT WHICH LIFTS NORTH OF I-80 AROUND 21Z THIS AFTN AND THEN DROPS BACK SOUTH. SEVERE WEATHER CONTINUES THIS EVENING...PRESUMABLY ELEVATED...WITH THE APPROACH OF THE MAIN UPPER LEVEL LOW. THE NAM AND OTHER MODELS LIFT A DECENT SHOT OF PV15 THROUGH THE FCST AREA. MEANWHILE...LATE SEASON ARCTIC AIR...CURRENTLY IN MONTANA DROPS THROUGH THE HIGH PLAINS FOR A ZONE OF THUNDERSTORMS CHANGING TO WET HEAVY SNOW. THE NAM BACKS THE ELEVATED INSTABILITY RIGHT UP AGAINST THE RAIN SNOW LINE ACROSS SHERIDAN COUNTY AROUND 09Z. THIS MIGHT BE TOO SLOW GIVEN THE PROXIMITY OF THE COLD AIR ACROSS MT AND THE RAIN SNOW LINE OVER NERN WY. THE RAP CAN FIGURE THIS OUT LATER TODAY. FOR NOW THE RAP HAS THE H700MB FREEZING LINE MOVING THROUGH SERN WY AT 00Z THIS EVENING SO A QUICKER CHANGE TO SNOW IS POSSIBLE. THE BEST GUESS ON SNOW AMOUNTS USES THE NAM...GEMREG...SREF AND ECM FOR QPF WITH A 5 OT 1 RATIO FOR UP TO 4 INCHES IN NORTHERN SHERIDAN COUNTY THROUGH 12Z THURSDAY MORING. LOCALLY HIGHER AMOUNTS COULD DEVELOP ESPECIALLY IF THE CHANGE OVER OCCURS AT 06Z VS THE NAM MODEL SHOWING 09Z. THE RAP HAS BEEN THE BEST PERFORMER THIS SPRING IN RAIN SNOW EVENTS FOLLOWED THE NAM. A WINTER WEATHER ADVISORY IS IN PLACE FOR SHERIDAN COUNTY 09Z-15Z TONIGHT THROUGH THURSDAY MORNING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 335 AM CDT WED MAY 7 2014 LARGE UPPER LEVEL TROUGH WILL CONTINUE TO SHIFT EAST NORTHEAST ACROSS THE CENTRAL PLAINS ON THURSDAY...REACHING THE NORTHERN MISSOURI VALLEY EARLY FRIDAY. IN THE WAKE OF THE UPPER TROUGH ...QUASI-ZONAL FLOW WILL PREVAIL THROUGH MUCH OF THE WEEKEND...BUT EVENTUALLY BREAK DOWN WITH THE APPROACH OF THE NEXT APPRECIABLE WESTERN STATES UPPER TROUGH. THE SURFACE PATTERN FAVORS A NORTHEASTWARD ADVANCING LOW TOWARD MINNESOTA AND FINALLY INTO SOUTHWEST ONTARIO BY EARLY FRIDAY. THIS LOW WILL DRAG A FRONT THROUGH THE CWA LEAVING POST FRONTAL CONDITIONS INTO EARLY FRIDAY...BUT THE LOWER TROPOSPHERIC FLOW WILL RETURN TO SOUTHERLY AS A LEE TROUGH DEVELOPS OFF THE HIGH PLAINS FRIDAY WITH THE APPROACH OF A WEAK NORTHERN PLAINS UPPER WAVE. THIS WAVE...AS IT/S PREDECESSOR...WILL DRAG AN ADDITIONAL FRONT THROUGH THE CWA ON SATURDAY. THE SATURDAY BAROCLINIC ZONE IS FORECAST TO BE WEAK...WITH LITTLE TO NO SENSIBLE CHANGES ANTICIPATED. FOR THURSDAY...WINTER WEATHER ADVISORY ACROSS SHERIDAN COUNTY WILL CONTINUE UNTIL 15Z. ALL THE MEDIUM RANGE DETERMINISTIC MODELS HAVE CONVERGED SOMEWHAT ON A SOLUTION FOR WHICH THERMAL PROFILES WOULD SUPPORT SNOW ACROSS SHERIDAN COUNTY. THERMAL PROFILES INDICATE A DEEP SATURATION...AT TIMES EXTENDING INTO THE DGZ...BUT WARM GROUND TEMPERATURES AND SFC T/S NEAR OR SLIGHTLY ABOVE 0C CREATE LOW CONFIDENCE FORECAST CONCERNING ACCUMULATIONS. SINCE A STRONG DEFORMATION ZONE IS SHOWN TO SET UP IN THIS AREA...CO-LOCATED IN THE TROWAL REGION OF THE SYSTEM...SNOW RATES MAY BE SUFFICIENT TO OVERCOME THE HIGH SUN ANGLE AND WARM TEMPERATURES...BUT CONFIDENCE IS NOT ENOUGH TO EXPIRE THE ADVISORY BEFORE 15Z. CONSEQUENTLY...GIVEN THE STRENGTH OF THE DEFORMATION...SNOW RATES MAY BE SUFFICIENT TO ALLOW FOR SLUSH ACCUMULATION PAST 15Z THURSDAY. FORECAST TIMING WITH THE CURRENT WINTER WEATHER ADVISORY MAY CHANGE WITH NEAR TERM GUIDANCE. WITH LOW LEVEL CAA ONGOING...HIGH TEMPERATURES THURSDAY WILL BE CHILLY...40S FOR THE NORTHWEST...POSSIBLY SOME 60S SOUTHEAST. WILL NEED TO MONITOR CLOUDS THURSDAY NIGHT AND FRIDAY MORNING AS ANY CLEARING WOULD LEAD TO SUB 0C LOWS...WITH THE THREAT OF A LIGHT FREEZE. ATTM...FAVORING THE ECMWF SOLUTION WHICH IS ON SLOWER SIDE...KEEPING SUFFICIENT CLOUDS ACROSS MUCH OF THE FORECAST AREA TO PREVENT A WIDESPREAD FREEZE. ATTM...NORTHWEST NEBRASKA WOULD HAVE THE HIGHEST POTENTIAL OF SEEING A DAMAGING FREEZE /TO YOUNG PLANTS/...ESPECIALLY IF SNOW TOTALS ARE HIGHER THAN CURRENTLY ANTICIPATED. THE ENTIRE NORTH PLATTE CWA HAS NOT REACHED THE 50 PERCENTILE FOR LAST FREEZE DATE...WE DO NOT PLAN TO FROST/FREEZE HEADLINES ATTM. FRIDAY...WITH RETURN FLOW DIRECTING WAA BACK INTO THE CWA...TEMPERATURES SHOULD WARM BACK WELL INTO THE 60S...POSSIBLY LOWER 70S FOR THE ENTIRE CWA. BUT A FAST MOVING WAVE PASSING THROUGH THE QUASI-ZONAL FLOW MAY SPARK OFF A SHOWER OR TWO DURING THE EVENING AND EARLY ON SATURDAY...WITH A WEAK WIND SHIFT TO FOLLOW. AGAIN SATURDAY TEMPERATURES WON/T BE TOO FAR OFF FROM CLIMO...GENERALLY HIGHS IN THE 60S TO LOWER 70S CAN BE EXPECTED FOR MOST IF NOT ALL LOCATIONS. LATE WEEKEND INTO EARLY NEXT WEEK...ANOTHER SYSTEM LOOKS TO MOVE INTO THE CENTRAL ROCKIES SATURDAY NIGHT AND EMERGE ONTO THE PLAINS SUNDAY AND MONDAY. WIDESPREAD PRECIPITATION WILL BE POSSIBLE...AND DESPITE DIFFERENCES WITH THE HANDLING OF THE SYSTEM...WILL MAINTAIN 30-40 POPS LATE WEEKEND INTO EARLY NEXT WEEK FOR MUCH OF THE CWA. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 632 AM CDT WED MAY 7 2014 MVFR/IFR IN SHOWERS AND SEVERE THUNDERSTORMS TODAY...MAINLY NORTH AND WEST OF KOGA-KVTN. VFR IS GENERALLY EXPECTED ELSEWHERE. TONIGHT THIS WEATHER SPREADS EAST TO KIML-KONL. AS THE UPPER LOW...CURRENTLY OVER WRN UT...LIFTS THROUGH WRN NEB LATE TONIGHT...MVFR CIGS SHOULD FILL IN SOUTH OF KVTN-KOGA. NOTE NORTH OF THAT LINE...MVFR/IFR/LOCAL LIFR IN RAIN AND SNOW IS EXPECTED. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 3 AM TO 9 AM MDT THURSDAY FOR NEZ004. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1027 AM CDT WED MAY 7 2014 .UPDATE... ISSUED AT 1026 AM CDT WED MAY 7 2014 UPDATE TO ADD SNOW AND SLEET TO PORTIONS OF NORTHWEST AND NORTH CENTRAL NORTH DAKOTA THIS MORNING FOR LOCATIONS IN THE MID TO UPPER 30S AS OF 1530 UTC. THIS IS BASED UPON MULTIPLE REPORTS BETWEEN WATFORD CITY AND WILLISTON AND THE KEENE AREAS AND DUAL POL SIGNATURES. UPDATE ISSUED AT 826 AM CDT WED MAY 7 2014 QUICK UPDATE TO ADJUST POPS TO THE LATEST OBSERVED TRENDS THROUGH 13 UTC...INCORPORATING THE 11 UTC RAP/HRRR THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY EVENING. ALSO DECREASED CLOUD COVER ACROSS THE NORTHWEST WHERE LOW TO MID LEVEL DECKS ARE THINNING WHICH SHOULD LEAD TO AT LEAST PARTLY SUNNY SKIES. UPDATE ISSUED AT 650 AM CDT WED MAY 7 2014 CURRENT RADAR OBS/TRENDS MATCH THE ONGOING FORECAST. FURTHERMORE...THE LATEST HRRR MATCHES THE LATEST RADAR OBS AND FORECAST TRENDS. WILL CONTINUE TO LEAN HEAVILY ON THE HRRR FOR HOURLY POPS THROUGH THE AFTERNOON. OTHERWISE...THE CURRENT FORECAST IS ON TRACK WITH NO MAJOR UPDATES REQUIRED. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 324 AM CDT WED MAY 7 2014 THE LATEST WATER VAPOR CONTINUES TO SHOW A MOIST SOUTHWEST FLOW INTO NORTH DAKOTA WITH MULTIPLE SHORTWAVES AHEAD OF A MAIN UPPER LOW NOW ALONG THE NEVADA/UTAH BORDER. THIS LOW WILL CLOSE OFF AND PIVOT NORTHEAST THROUGH THE SHORT TERM PERIOD...AND WILL BECOME THE MAIN PRECIPITATION PRODUCER OVER SOUTH CENTRAL NORTH DAKOTA LATER WEDNESDAY NIGHT. UNTIL THEN...MODEL GUIDANCE SUGGESTING SEVERAL AREAS OF RAIN SHOWERS WILL MOVE FROM SOUTHWEST TO NORTHEAST TODAY AND THUS FAR LOCAL/REGIONAL RADAR CONFIRMS THIS. OVERALL POPS ARE LIKELY TO CATEGORICAL FOR WESTERN AND MOST OF CENTRAL NORTH DAKOTA TODAY...WITH THE JAMES RIVER VALLEY SEEING HIGHEST POPS LATER THIS AFTERNOON AND AGAIN LATE WEDNESDAY NIGHT. CATEGORICAL POPS HAVE BEEN PAINTED ALONG/NEAR A SURFACE INVERTED TROUGH/BAROCLINIC ZONE...WHICH CURRENTLY STRETCHES FROM SHERWOOD TO MINOT...SOUTH TO CENTER AND INTO MOBRIDGE SOUTH DAKOTA. THIS SURFACE TROUGH WILL SHIFT EAST DURING THE DAY REACHING THE JAMES RIVER VALLEY LATE THIS AFTERNOON. ONCE THIS TROUGH EXITS THE JAMES RIVER VALLEY EARLY THIS EVENING...EXPECT A BRIEF LULL IN THE WIDESPREAD PRECIPITATION...ESSENTIALLY COVERING THE 00Z-06Z THURSDAY TIME FRAME. HOWEVER POPS WILL ONCE AGAIN INCREASE ACROSS THE SOUTH AND SOUTH CENTRAL TOWARD AND AFTER 06Z THURSDAY IN RESPONSE TO THE VERTICAL MOTION FIELD AS THE CLOSED MID LEVEL LOW APPROACHES. HAVE MAINTAINED THE TREND TO KEEP ANY MENTION OF THUNDER SOUTH OF THE BORDER AS INSTABILITY PARAMETERS PER GFS FOLLOW THIS TREND. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 324 AM CDT WED MAY 7 2014 AN UPPER LEVEL SHORTWAVE EMANATING FROM THE ROCKIES IS PROGGED TO LIFT NORTH ACROSS THE CENTRAL AND NORTHERN PLAINS THURSDAY. THIS FEATURE SHOULD GENERATE RAIN SHOWERS EXTENDING ALONG AND SOUTH OF A LINE FROM HETTINGER TO BISMARCK TO HARVEY. HOWEVER...HIGH PRESSURE BUILDING INTO EASTERN MONTANA SHOULD KEEP THE FORECAST DRY FOR NORTHWESTERN NORTH DAKOTA. A BREAK IN PRECIP CHANCES IS FORECAST FOR FRIDAY AS HIGH PRESSURE CRESTS ACROSS THE REGION. TEMPERATURES ARE FORECAST TO GET IN THE MID TO UPPER 60S FRIDAY. PRECIPITATION CHANCES RETURN OVER NORTH DAKOTA SATURDAY AS A SHORTWAVE EMANATING FROM THE PACIFIC NORTHWEST TRAVERSES THE NORTHERN PLAINS. THE MEDIUM RANGE MODELS DIVERGE WITH RESPECT TO THE UPPER PATTERN OVER THE CONUS SUNDAY THROUGH THE REMAINDER OF THE PERIOD. THEREFORE...THERE IS QUITE A BIT OF UNCERTAINTY REGARDING THE FORECAST FOR THE FIRST HALF OF NEXT WEEK. EVEN THOUGH A PERSISTENT UPPER LEVEL LOW OVER SASKATCHEWAN IS FORECAST TO MAINTAIN AN UNSETTLED WEATHER REGIME OVER NORTH DAKOTA...THE MODELS HAVE BEEN BACKING OFF ON PRECIP CHANCES/QPF AMOUNTS DUE TO DRY SLOTTING. AS A RESULT...LOWERED POPS TO SLIGHT CHANCE/LOW-END CHANCE SUNDAY AND MONDAY...AND REMOVED POPS FOR MOST OF THE CWA TUESDAY. TEMPERATURES ARE STILL FORECAST TO REMAIN BELOW CLIMO VALUES THIS WEEKEND THROUGH THE FIRST PART OF NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY) ISSUED AT 1026 AM CDT WED MAY 7 2014 IFR/LIFR CONDITIONS AT KDIK AND KMOT IN RAIN...STRATUS AND FOG WILL IMPROVE TO MVFR BY AFTERNOON. MVFR CONDITIONS IN RAIN WILL BEGIN AT KBIS BY 16 UTC...AND CONTINUE THROUGH 19-20 UTC. RAIN WILL APPROACH KJMS BY 18 UTC AND CONTINUE THROUGH 22-23 UTC. MVFR CONDITIONS IN STRATUS ARE POSSIBLE AT KBIS/KJMS THEREAFTER. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...KS LONG TERM...TM AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
826 AM CDT WED MAY 7 2014 .UPDATE... ISSUED AT 826 AM CDT WED MAY 7 2014 QUICK UPDATE TO ADJUST POPS TO THE LATEST OBSERVED TRENDS THROUGH 13 UTC...INCORPORATING THE 11 UTC RAP/HRRR THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY EVENING. ALSO DECREASED CLOUD COVER ACROSS THE NORTHWEST WHERE LOW TO MID LEVEL DECKS ARE THINNING WHICH SHOULD LEAD TO AT LEAST PARTLY SUNNY SKIES. UPDATE ISSUED AT 650 AM CDT WED MAY 7 2014 CURRENT RADAR OBS/TRENDS MATCH THE ONGOING FORECAST. FURTHERMORE...THE LATEST HRRR MATCHES THE LATEST RADAR OBS AND FORECAST TRENDS. WILL CONTINUE TO LEAN HEAVILY ON THE HRRR FOR HOURLY POPS THROUGH THE AFTERNOON. OTHERWISE...THE CURRENT FORECAST IS ON TRACK WITH NO MAJOR UPDATES REQUIRED. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 324 AM CDT WED MAY 7 2014 THE LATEST WATER VAPOR CONTINUES TO SHOW A MOIST SOUTHWEST FLOW INTO NORTH DAKOTA WITH MULTIPLE SHORTWAVES AHEAD OF A MAIN UPPER LOW NOW ALONG THE NEVADA/UTAH BORDER. THIS LOW WILL CLOSE OFF AND PIVOT NORTHEAST THROUGH THE SHORT TERM PERIOD...AND WILL BECOME THE MAIN PRECIPITATION PRODUCER OVER SOUTH CENTRAL NORTH DAKOTA LATER WEDNESDAY NIGHT. UNTIL THEN...MODEL GUIDANCE SUGGESTING SEVERAL AREAS OF RAIN SHOWERS WILL MOVE FROM SOUTHWEST TO NORTHEAST TODAY AND THUS FAR LOCAL/REGIONAL RADAR CONFIRMS THIS. OVERALL POPS ARE LIKELY TO CATEGORICAL FOR WESTERN AND MOST OF CENTRAL NORTH DAKOTA TODAY...WITH THE JAMES RIVER VALLEY SEEING HIGHEST POPS LATER THIS AFTERNOON AND AGAIN LATE WEDNESDAY NIGHT. CATEGORICAL POPS HAVE BEEN PAINTED ALONG/NEAR A SURFACE INVERTED TROUGH/BAROCLINIC ZONE...WHICH CURRENTLY STRETCHES FROM SHERWOOD TO MINOT...SOUTH TO CENTER AND INTO MOBRIDGE SOUTH DAKOTA. THIS SURFACE TROUGH WILL SHIFT EAST DURING THE DAY REACHING THE JAMES RIVER VALLEY LATE THIS AFTERNOON. ONCE THIS TROUGH EXITS THE JAMES RIVER VALLEY EARLY THIS EVENING...EXPECT A BRIEF LULL IN THE WIDESPREAD PRECIPITATION...ESSENTIALLY COVERING THE 00Z-06Z THURSDAY TIME FRAME. HOWEVER POPS WILL ONCE AGAIN INCREASE ACROSS THE SOUTH AND SOUTH CENTRAL TOWARD AND AFTER 06Z THURSDAY IN RESPONSE TO THE VERTICAL MOTION FIELD AS THE CLOSED MID LEVEL LOW APPROACHES. HAVE MAINTAINED THE TREND TO KEEP ANY MENTION OF THUNDER SOUTH OF THE BORDER AS INSTABILITY PARAMETERS PER GFS FOLLOW THIS TREND. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 324 AM CDT WED MAY 7 2014 AN UPPER LEVEL SHORTWAVE EMANATING FROM THE ROCKIES IS PROGGED TO LIFT NORTH ACROSS THE CENTRAL AND NORTHERN PLAINS THURSDAY. THIS FEATURE SHOULD GENERATE RAIN SHOWERS EXTENDING ALONG AND SOUTH OF A LINE FROM HETTINGER TO BISMARCK TO HARVEY. HOWEVER...HIGH PRESSURE BUILDING INTO EASTERN MONTANA SHOULD KEEP THE FORECAST DRY FOR NORTHWESTERN NORTH DAKOTA. A BREAK IN PRECIP CHANCES IS FORECAST FOR FRIDAY AS HIGH PRESSURE CRESTS ACROSS THE REGION. TEMPERATURES ARE FORECAST TO GET IN THE MID TO UPPER 60S FRIDAY. PRECIPITATION CHANCES RETURN OVER NORTH DAKOTA SATURDAY AS A SHORTWAVE EMANATING FROM THE PACIFIC NORTHWEST TRAVERSES THE NORTHERN PLAINS. THE MEDIUM RANGE MODELS DIVERGE WITH RESPECT TO THE UPPER PATTERN OVER THE CONUS SUNDAY THROUGH THE REMAINDER OF THE PERIOD. THEREFORE...THERE IS QUITE A BIT OF UNCERTAINTY REGARDING THE FORECAST FOR THE FIRST HALF OF NEXT WEEK. EVEN THOUGH A PERSISTENT UPPER LEVEL LOW OVER SASKATCHEWAN IS FORECAST TO MAINTAIN AN UNSETTLED WEATHER REGIME OVER NORTH DAKOTA...THE MODELS HAVE BEEN BACKING OFF ON PRECIP CHANCES/QPF AMOUNTS DUE TO DRY SLOTTING. AS A RESULT...LOWERED POPS TO SLIGHT CHANCE/LOW-END CHANCE SUNDAY AND MONDAY...AND REMOVED POPS FOR MOST OF THE CWA TUESDAY. TEMPERATURES ARE STILL FORECAST TO REMAIN BELOW CLIMO VALUES THIS WEEKEND THROUGH THE FIRST PART OF NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 826 AM CDT WED MAY 7 2014 IFR/LIFR CONDITIONS AT KDIK AND KMOT IN RAIN...STRATUS AND FOG WILL IMPROVE TO MVFR BY AFTERNOON. MVFR CONDITIONS IN RAIN WILL BEGIN AT KBIS BY 16 UTC...AND CONTINUE THROUGH 19-20 UTC. RAIN WILL APPROACH KJMS BY 18 UTC AND CONTINUE THROUGH 22-23 UTC. MVFR CONDITIONS IN STRATUS ARE POSSIBLE AT KBIS/KJMS THEREAFTER. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...KS LONG TERM...TM AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
650 AM CDT WED MAY 7 2014 .UPDATE... ISSUED AT 650 AM CDT WED MAY 7 2014 CURRENT RADAR OBS/TRENDS MATCH THE ONGOING FORECAST. FURTHERMORE...THE LATEST HRRR MATCHES THE LATEST RADAR OBS AND FORECAST TRENDS. WILL CONTINUE TO LEAN HEAVILY ON THE HRRR FOR HOURLY POPS THROUGH THE AFTERNOON. OTHERWISE...THE CURRENT FORECAST IS ON TRACK WITH NO MAJOR UPDATES REQUIRED. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 324 AM CDT WED MAY 7 2014 THE LATEST WATER VAPOR CONTINUES TO SHOW A MOIST SOUTHWEST FLOW INTO NORTH DAKOTA WITH MULTIPLE SHORTWAVES AHEAD OF A MAIN UPPER LOW NOW ALONG THE NEVADA/UTAH BORDER. THIS LOW WILL CLOSE OFF AND PIVOT NORTHEAST THROUGH THE SHORT TERM PERIOD...AND WILL BECOME THE MAIN PRECIPITATION PRODUCER OVER SOUTH CENTRAL NORTH DAKOTA LATER WEDNESDAY NIGHT. UNTIL THEN...MODEL GUIDANCE SUGGESTING SEVERAL AREAS OF RAIN SHOWERS WILL MOVE FROM SOUTHWEST TO NORTHEAST TODAY AND THUS FAR LOCAL/REGIONAL RADAR CONFIRMS THIS. OVERALL POPS ARE LIKELY TO CATEGORICAL FOR WESTERN AND MOST OF CENTRAL NORTH DAKOTA TODAY...WITH THE JAMES RIVER VALLEY SEEING HIGHEST POPS LATER THIS AFTERNOON AND AGAIN LATE WEDNESDAY NIGHT. CATEGORICAL POPS HAVE BEEN PAINTED ALONG/NEAR A SURFACE INVERTED TROUGH/BAROCLINIC ZONE...WHICH CURRENTLY STRETCHES FROM SHERWOOD TO MINOT...SOUTH TO CENTER AND INTO MOBRIDGE SOUTH DAKOTA. THIS SURFACE TROUGH WILL SHIFT EAST DURING THE DAY REACHING THE JAMES RIVER VALLEY LATE THIS AFTERNOON. ONCE THIS TROUGH EXITS THE JAMES RIVER VALLEY EARLY THIS EVENING...EXPECT A BRIEF LULL IN THE WIDESPREAD PRECIPITATION...ESSENTIALLY COVERING THE 00Z-06Z THURSDAY TIME FRAME. HOWEVER POPS WILL ONCE AGAIN INCREASE ACROSS THE SOUTH AND SOUTH CENTRAL TOWARD AND AFTER 06Z THURSDAY IN RESPONSE TO THE VERTICAL MOTION FIELD AS THE CLOSED MID LEVEL LOW APPROACHES. HAVE MAINTAINED THE TREND TO KEEP ANY MENTION OF THUNDER SOUTH OF THE BORDER AS INSTABILITY PARAMETERS PER GFS FOLLOW THIS TREND. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 324 AM CDT WED MAY 7 2014 AN UPPER LEVEL SHORTWAVE EMANATING FROM THE ROCKIES IS PROGGED TO LIFT NORTH ACROSS THE CENTRAL AND NORTHERN PLAINS THURSDAY. THIS FEATURE SHOULD GENERATE RAIN SHOWERS EXTENDING ALONG AND SOUTH OF A LINE FROM HETTINGER TO BISMARCK TO HARVEY. HOWEVER...HIGH PRESSURE BUILDING INTO EASTERN MONTANA SHOULD KEEP THE FORECAST DRY FOR NORTHWESTERN NORTH DAKOTA. A BREAK IN PRECIP CHANCES IS FORECAST FOR FRIDAY AS HIGH PRESSURE CRESTS ACROSS THE REGION. TEMPERATURES ARE FORECAST TO GET IN THE MID TO UPPER 60S FRIDAY. PRECIPITATION CHANCES RETURN OVER NORTH DAKOTA SATURDAY AS A SHORTWAVE EMANATING FROM THE PACIFIC NORTHWEST TRAVERSES THE NORTHERN PLAINS. THE MEDIUM RANGE MODELS DIVERGE WITH RESPECT TO THE UPPER PATTERN OVER THE CONUS SUNDAY THROUGH THE REMAINDER OF THE PERIOD. THEREFORE...THERE IS QUITE A BIT OF UNCERTAINTY REGARDING THE FORECAST FOR THE FIRST HALF OF NEXT WEEK. EVEN THOUGH A PERSISTENT UPPER LEVEL LOW OVER SASKATCHEWAN IS FORECAST TO MAINTAIN AN UNSETTLED WEATHER REGIME OVER NORTH DAKOTA...THE MODELS HAVE BEEN BACKING OFF ON PRECIP CHANCES/QPF AMOUNTS DUE TO DRY SLOTTING. AS A RESULT...LOWERED POPS TO SLIGHT CHANCE/LOW-END CHANCE SUNDAY AND MONDAY...AND REMOVED POPS FOR MOST OF THE CWA TUESDAY. TEMPERATURES ARE STILL FORECAST TO REMAIN BELOW CLIMO VALUES THIS WEEKEND THROUGH THE FIRST PART OF NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 650 AM CDT WED MAY 7 2014 WIDESPREAD RAIN SHOWERS WILL CONTINUE RESULTING IN IFR CIGS AND MVFR VSBYS AT KDIK/KMOT THROUGH EARLY WEDNESDAY EVENING. ALTHOUGH KISN WILL BEGIN WITH BORDERLINE IFR CIGS...EXPECT PRECIPITATION TO END WITH CIGS IMPROVING TO VFR BY 15Z WEDNESDAY. AT KBIS...CIGS WILL DETERIORATE TO MVFR BY 16Z WEDNESDAY AND REMAIN THERE THROUGH 12Z THURSDAY. KJMS WILL REMAIN VFR THROUGH WEDNESDAY EVENING...THEN IFR CIGS AND MVFR VSBYS TAKE CONTROL BY 09Z THURSDAY. NORTHERLY WINDS OF 15KT TO 25KT WILL SPREAD FROM WEST TO EAST THROUGH THE TAF PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TM SHORT TERM...KS LONG TERM...TM AVIATION...KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
652 AM EDT WED MAY 7 2014 .SYNOPSIS... A WARM FRONT WILL LIFT NORTH THROUGH THE OHIO VALLEY TODAY...ALLOWING FOR TEMPERATURES WELL ABOVE NORMAL TODAY AND THURSDAY. SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE AREA ON FRIDAY AND SATURDAY...AS A COLD FRONT SLOWLY MOVES EAST THROUGH THE REGION. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A RATHER HEALTHY BAND OF CONVECTION HAS DEVELOPED IN SOUTHERN MICHIGAN AND NORTHWESTERN OHIO...ALONG AN AXIS GENERALLY PARALLEL TO (BUT A COUPLE HUNDRED MILES REMOVED FROM) THE SURFACE WARM FRONT. OBVIOUSLY ELEVATED IN NATURE...THIS CONVECTION IS ON A TRAJECTORY TO MISS THE ILN FORECAST AREA ENTIRELY. JUST A SLIGHT CHANCE OF A SHOWER HAS BEEN KEPT IN THE FAR NORTHERN/NORTHEASTERN ILN COUNTIES FOR A FEW HOURS. RIDGING IS ALREADY BUILDING INTO THE FORECAST AREA...WITH 925MB TEMPERATURES ALREADY BEGINNING TO RISE. THE ACTUAL SURFACE WARM FRONT WILL CROSS THE CWA FROM SOUTH TO NORTH BETWEEN EARLY THIS MORNING AND AROUND 18Z...SHIFTING FLOW TO THE SOUTHWEST THROUGH THE COLUMN...SETTING UP A FAVORABLE WARM ADVECTION PATTERN. ALL SIGNS POINT TO A WELL MIXED BOUNDARY LAYER TODAY...WHICH SHOULD ALLOW FOR A SIGNIFICANT WARMING IN TEMPERATURES TO THE LOWER TO MID 80S...AS WELL AS WIND GUSTS INTO THE 20-30 MPH RANGE. RECORD HIGHS FOR TODAY (MAY 7) APPEAR TO BE SAFE. CMH: 87 / 1936 DAY: 87 / 1926 AND 1897 CVG: 89 / 1940 ONLY THE RAP (WITH ITS OVER-MIXED BOUNDARY LAYER TENDENCIES) HAD VALUES ANYWHERE NEAR THOSE NUMBERS. THIS FORECAST WILL STAY A FEW DEGREES BELOW THE RAP...BUT ON THE HIGHER SIDE OF THE REST OF THE GUIDANCE. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... CONTINUED SOUTHWESTERLY FLOW WILL LEAD TO MILD CONDITIONS TONIGHT...BEFORE ANOTHER VERY WARM DAY IS EXPECTED ON THURSDAY. THE OVERALL WEATHER PATTERN WILL BE CHANGING VERY LITTLE...WITH MID-LEVEL RIDGING OVER THE OHIO VALLEY (EXTENDING FROM THE SOUTHEASTERN STATES). ANOTHER WELL-MIXED DAY WITH APPRECIABLE AMOUNTS OF SUN WILL LEAD TO SIMILAR TEMPERATURES TO WEDNESDAY...PERHAPS EVEN A FEW DEGREES WARMER. RECORD HIGHS FOR ALL THREE CLIMATE SITES ARE 89 DEGREES FOR MAY 8...AND AGAIN AS ON WEDNESDAY...THESE LOOK TO BE SAFE. GOING INTO FRIDAY...A BROAD UPPER TROUGH WILL BE MOVING NORTHEAST FROM THE PLAINS INTO CANADA...WITH A SURFACE LOW FORECAST TO RIDE ALONG THE TROUGH THROUGH MINNESOTA AND INTO NORTHERN ONTARIO. A COLD FRONT WILL EXTEND FROM SOUTH OF THIS LOW AND WILL MOVE INTO THE OHIO VALLEY ON FRIDAY. WITH THE LOW SO FAR AWAY FROM THE REGION...AND THE MID-LEVEL FLOW FAILING TO BECOME PARTICULARLY SHARP...THERE IS LITTLE IMPETUS FOR THE FRONT TO MAINTAIN ITS STRENGTH AS IT LUMBERS EASTWARD. THIS SETS UP FORECAST WITH SPECIFICS THAT REMAIN RATHER UNCERTAIN...WITH CONCERNS OF TIMING AND FORCING STRENGTH PRECLUDING ANY HIGHER THAN 70-PERCENT POPS DURING THE SPAN FROM FRIDAY THROUGH SATURDAY (EVEN THOUGH IT IS VERY LIKELY THAT THE ENTIRE CWA WILL GET SOME RAIN OUT OF THIS SYSTEM). THE FIRST WAVE AHEAD OF THE FRONT (MOVING INTO THE ILN CWA ON FRIDAY MORNING) APPEARS TO FALL APART AS IT GETS TOO FAR AHEAD OF THE SURFACE TROUGH...AND THE BIGGEST QUESTION WITH THE SECOND WAVE IS THE TIMING (WITH A FEW MODELS NOW SHOWING THIS MORE AS A FRIDAY NIGHT ISSUE THAN A SATURDAY ONE). WITH QUESTIONABLE LOW-LEVEL MOISTURE ON FRIDAY (LIMITING INSTABILITY)...AND THE WEAK FORCING AND SLOW FRONTAL MOTION ALSO FACTORED IN...THE THREAT FOR STRONG STORMS APPEARS RATHER LOW. THE PLACEMENT OF THE SECOND WAVE WILL END UP DETERMINING IF ANY CHANCE FOR HEAVY OR PROLONGED RAIN MIGHT LEAD TO A POSSIBILITY OF FLOODING...BUT THIS ALSO APPEARS TO BE A LOW-END THREAT. TEMPERATURES WILL ALSO BE HELD DOWN BY THE OCCASIONAL RAIN AND PERSISTENT CLOUD COVER...WITH A GRADIENT FROM THE MID 70S (NW CWA) TO NEAR 80 (SE CWA) ON FRIDAY...THEN NEAR 70 DEGREES EXPECTED ON SATURDAY. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... MODEL SOLUTIONS DIVERGE THEREAFTER. ELECTED TO GO CLOSER TO THE ECMWF WHICH...AFTER AN INTERLUDE OF SOMEWHAT DRIER CONDITIONS ON SUNDAY AND MONDAY...BRINGS THE NEXT COLD FRONT CONTAINING A CHANCE OF THUNDERSTORMS ON TUESDAY. EXPECT HIGH TEMPERATURES PRIMARILY IN THE 70S. THE EXCEPTION MAY BE ON MONDAY...WHEN WARM ADVECTION MAY PUSH READINGS INTO THE LOWER 80S. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... A MID LEVEL RIDGE WILL BUILD NORTH INTO THE SOUTHERN GREAT LAKES TODAY. AS THIS OCCURS...A WARM FRONT WILL LIFT NORTH ACROSS THE REGION THIS MORNING. FOR THIS AFTERNOON...REGION WILL BE LOCATED IN THE WARM SECTOR. DAYTIME MIXING WILL RESULT IN SOUTHERLY WINDS IN THE 10 TO 15 KNOT RANGE WITH GUSTS GENERALLY IN THE 20 TO 25 KNOT RANGE. MAINLY HIGH LEVEL CLOUDS WILL THIN SOME BY AFTERNOON. FOR TONIGHT...MID LEVEL RIDGE WILL REMAIN IN PLACE WITH MOSTLY CLEAR SKIES EXPECTED. OUTLOOK...THUNDERSTORMS POSSIBLE FRIDAY INTO SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HATZOS NEAR TERM...HATZOS SHORT TERM...HATZOS LONG TERM...CONIGLIO AVIATION...HICKMAN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1058 AM CDT WED MAY 7 2014 .UPDATE... MADE A FEW CHANGES TO THE FORECAST THIS MORNING...MAINLY TO DECREASE POP THROUGH THIS AFTERNOON. AN UPPER LEVEL SHORT WAVE JUST OFF TO THE WEST OF ABERDEEN WILL CONTINUE TO PUSH NORTHEASTWARD INTO NORTH DAKOTA. THIS SYSTEM IS PRODUCING LIGHT SHOWERS ACROSS NORTH CENTRAL SOUTH DAKOTA. BETTER LLM AND SHEAR FURTHER EAST IS RESULTING IN MARGINALLY STRONG STORMS WITH RADAR SHOWING SOME SMALL HAIL POSSIBLE. THESE STORMS SHOULD CONTINUE PUSHING INTO SE NORTH DAKOTA WITHIN THE NEXT FEW HOURS. THERE IS A GOOD POSSIBILITY FOR DRY CONDITIONS THROUGH THIS AFTERNOON BEFORE THE NEXT UPPER LEVEL SHORT WAVE MOVES INTO THE REGION FROM THE SOUTHWEST. && .PREVIOUS DISCUSSION... .SHORT TERM...THROUGH FRIDAY WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY CONTINUES BOTH SOUTH AND WEST OF THE CWA THANKS TO SOUTHWEST FLOW ALOFT WITH WEAK EMBEDDED WAVES. THE 06Z HRRR BRINGS CONVECTIVE REMNANTS INTO THE WESTERN CWA THROUGH THE MORNING HOURS...BUT HAVE ALREADY SEEN SIMILAR ATTEMPTS BY SHOWERS TO CROSS INTO THE FORECAST AREA...ONLY TO WASH OUT...SO FORECASTER CONFIDENCE CONTINUES TO REMAIN LOW EVEN IN THE NEAR TERM. MODELS DO HAVE A BETTER DEFINED WAVE MOVING UP FROM THE SOUTH TODAY. BEST ISENTROPIC FORCING WILL SET UP JUST NORTH OF A KMBG TO KPHP LINE. INSTABILITY PEAKS JUST SOUTH OF A WARM FRONT FOR THE EASTERN CWA THIS AFTERNOON AS WELL. LOOKING AT NAM/RAP PROFILES...SURFACE BASED CONVECTION APPEARS UNLIKELY AS THE FRONT IS SOUTH OF THE CWA...AND GUIDANCE HAS A DIFFICULT TIME WARMING ENOUGH TO OVERCOME THE INVERSION. STEEP LAPSE RATES ABOVE THE INVERSION WITH STRONG SOUTHWEST MID LEVEL FLOW WILL SUPPORT A HAIL THREAT IF ANY STORMS DO DEVELOP. OVERNIGHT...A COUPLED JET STRUCTURE WILL SUPPORT AN AREA OF RAIN THAT WILL LIFT OUT OF THE NEBRASKA PANHANDLE THROUGH WESTERN/CENTRAL SOUTH DAKOTA. MOST OF THE GUIDANCE TAKES THIS FEATURE NORTHEAST BETWEEN KPIR AND KMBG...THOUGH SREF GUIDANCE IS A TAD FARTHER WEST. SREF PROBABILITIES SUGGEST FAIRLY HIGH QPF POTENTIAL WITH THIS FEATURE...WHICH IS SUPPORTED WITHIN MOST GUIDANCE. THE GFS IS PEGGED AT NEARLY 30 MICROBARS OF LIFT BY 12Z THURSDAY. TROWAL WRAP AROUND LIGHT RAIN WILL CONTINUE THROUGH THE DAY...BUT WE WILL SEE ISENTROPIC DOWNGLIDE BY LATE AFTERNOON/EVENING HELPING TO DRY US OUT FOR FRIDAY. .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY THE EXTENDED PERIOD CONTINUES THE ACTIVE PATTERN WITH A COUPLE OF SYSTEMS MOVING THROUGH. THE FIRST WEAKER WAVE MOVES OFF THE ROCKIES FRIDAY NIGHT AND INTO EASTERN SD SATURDAY BRINGING SOME SHOWERS AND TSTORMS. THERE WILL LIKELY BE A BRIEF BREAK IN PRECIP SAT MORNING BEFORE A MORE WELL DEVELOPED SFC LOW ENTERS THE CENTRAL PLAINS SAT NIGHT. AT THE SAME TIME AN UPPER LOW WILL DROP DOWN INTO ND. WHILE THE MODELS AGREE ON THE SFC SYNOPTIC PATTERN...THERE IS SOME DISCREPANCY AT JUST WHEN THE UPPER TROF WILL BEGIN TO AFFECT THE NORTHERN PLAINS. THIS WILL INFLUENCE AREAL COVERAGE OF PRECIP DURING ANY GIVEN PERIOD FROM SAT NIGHT THROUGH TUESDAY. THE ECMWF KEEPS THE PRECIP ONLY OVER THE FAR SOUTHERN CWA WHILE THE GFS HAS THE ENERGY FROM THE UPPER LOW DIGGING A LITTLE FARTHER SOUTH ON SUNDAY. KEPT ALLBLEND POPS FOR NOW OVER THE WEEKEND BUT A DRIER SOLUTION IS POSSIBLE. TEMPERATURES WILL TREND DOWN THROUGH THE PERIOD WITH THE COOLEST TEMPS OCCURRING WHEN THE LONGWAVE TROUGH MOVES OVER THE PLAINS. TEMPS WILL BE AROUND 10 DEGREES COOLER THAN AVERAGE BY THE LATTER HALF OF THE EXTENDED. && .AVIATION... 12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS VFR CONDITIONS ARE EXPECTED THROUGH EARLY AFTERNOON. SHOWERS AND THUNDERSTORMS WILL SPREAD EASTWARD DURING THE LATE AFTERNOON AND EVENING. THE MOST LIKELY LOCATION TO SEE THUNDERSTORM ACTIVITY WILL BE ACROSS THE SOUTHERN AND FAR EASTERN CWA...POSSIBLY AFFECTING KPIR AND KATY FROM 21Z. CIGS WILL FALL INTO THE MVFR CATEGORY BY LATE AFTERNOON...THEN INTO THE IFR CATEGORY BEHIND THE LOW OVERNIGHT. LOWER VSBYS WILL BE POSSIBLE WITH THE PRECIPITATION AS WELL. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...SD SHORT TERM...CONNELLY LONG TERM...WISE AVIATION...WISE WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
656 AM CDT WED MAY 7 2014 .UPDATE... KNOCKED BACK EASTERN PROGRESSION OF POPS THIS MORNING AS LITTLE IF ANYTHING IS MAKING IT EAST OF THE MISSOURI RIVER ON RADAR. ALSO TOOK OUT MENTION OF THUNDER THIS MORNING. BEST CHANCES FOR TSTORM DEVELOPMENT APPEAR TO BE 20Z INTO THIS EVENING. SEE UPDATED AVIATION DISCUSSION BELOW. && .PREVIOUS DISCUSSION... .SHORT TERM...THROUGH FRIDAY WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY CONTINUES BOTH SOUTH AND WEST OF THE CWA THANKS TO SOUTHWEST FLOW ALOFT WITH WEAK EMBEDDED WAVES. THE 06Z HRRR BRINGS CONVECTIVE REMNANTS INTO THE WESTERN CWA THROUGH THE MORNING HOURS...BUT HAVE ALREADY SEEN SIMILAR ATTEMPTS BY SHOWERS TO CROSS INTO THE FORECAST AREA...ONLY TO WASH OUT...SO FORECASTER CONFIDENCE CONTINUES TO REMAIN LOW EVEN IN THE NEAR TERM. MODELS DO HAVE A BETTER DEFINED WAVE MOVING UP FROM THE SOUTH TODAY. BEST ISENTROPIC FORCING WILL SET UP JUST NORTH OF A KMBG TO KPHP LINE. INSTABILITY PEAKS JUST SOUTH OF A WARM FRONT FOR THE EASTERN CWA THIS AFTERNOON AS WELL. LOOKING AT NAM/RAP PROFILES...SURFACE BASED CONVECTION APPEARS UNLIKELY AS THE FRONT IS SOUTH OF THE CWA...AND GUIDANCE HAS A DIFFICULT TIME WARMING ENOUGH TO OVERCOME THE INVERSION. STEEP LAPSE RATES ABOVE THE INVERSION WITH STRONG SOUTHWEST MID LEVEL FLOW WILL SUPPORT A HAIL THREAT IF ANY STORMS DO DEVELOP. OVERNIGHT...A COUPLED JET STRUCTURE WILL SUPPORT AN AREA OF RAIN THAT WILL LIFT OUT OF THE NEBRASKA PANHANDLE THROUGH WESTERN/CENTRAL SOUTH DAKOTA. MOST OF THE GUIDANCE TAKES THIS FEATURE NORTHEAST BETWEEN KPIR AND KMBG...THOUGH SREF GUIDANCE IS A TAD FARTHER WEST. SREF PROBABILITIES SUGGEST FAIRLY HIGH QPF POTENTIAL WITH THIS FEATURE...WHICH IS SUPPORTED WITHIN MOST GUIDANCE. THE GFS IS PEGGED AT NEARLY 30 MICROBARS OF LIFT BY 12Z THURSDAY. TROWAL WRAP AROUND LIGHT RAIN WILL CONTINUE THROUGH THE DAY...BUT WE WILL SEE ISENTROPIC DOWNGLIDE BY LATE AFTERNOON/EVENING HELPING TO DRY US OUT FOR FRIDAY. .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY THE EXTENDED PERIOD CONTINUES THE ACTIVE PATTERN WITH A COUPLE OF SYSTEMS MOVING THROUGH. THE FIRST WEAKER WAVE MOVES OFF THE ROCKIES FRIDAY NIGHT AND INTO EASTERN SD SATURDAY BRINGING SOME SHOWERS AND TSTORMS. THERE WILL LIKELY BE A BRIEF BREAK IN PRECIP SAT MORNING BEFORE A MORE WELL DEVELOPED SFC LOW ENTERS THE CENTRAL PLAINS SAT NIGHT. AT THE SAME TIME AN UPPER LOW WILL DROP DOWN INTO ND. WHILE THE MODELS AGREE ON THE SFC SYNOPTIC PATTERN...THERE IS SOME DISCREPANCY AT JUST WHEN THE UPPER TROF WILL BEGIN TO AFFECT THE NORTHERN PLAINS. THIS WILL INFLUENCE AREAL COVERAGE OF PRECIP DURING ANY GIVEN PERIOD FROM SAT NIGHT THROUGH TUESDAY. THE ECMWF KEEPS THE PRECIP ONLY OVER THE FAR SOUTHERN CWA WHILE THE GFS HAS THE ENERGY FROM THE UPPER LOW DIGGING A LITTLE FARTHER SOUTH ON SUNDAY. KEPT ALLBLEND POPS FOR NOW OVER THE WEEKEND BUT A DRIER SOLUTION IS POSSIBLE. TEMPERATURES WILL TREND DOWN THROUGH THE PERIOD WITH THE COOLEST TEMPS OCCURRING WHEN THE LONGWAVE TROUGH MOVES OVER THE PLAINS. TEMPS WILL BE AROUND 10 DEGREES COOLER THAN AVERAGE BY THE LATTER HALF OF THE EXTENDED. && .AVIATION... 12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS VFR CONDITIONS ARE EXPECTED THROUGH EARLY AFTERNOON. SHOWERS AND THUNDERSTORMS WILL SPREAD EASTWARD DURING THE LATE AFTERNOON AND EVENING. THE MOST LIKELY LOCATION TO SEE THUNDERSTORM ACTIVITY WILL BE ACROSS THE SOUTHERN AND FAR EASTERN CWA...POSSIBLY AFFECTING KPIR AND KATY FROM 21Z. CIGS WILL FALL INTO THE MVFR CATEGORY BY LATE AFTERNOON...THEN INTO THE IFR CATEGORY BEHIND THE LOW OVERNIGHT. LOWER VSBYS WILL BE POSSIBLE WITH THE PRECIPITATION AS WELL. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...WISE SHORT TERM...CONNELLY LONG TERM...WISE AVIATION...WISE WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1132 AM EDT WED MAY 7 2014 .SYNOPSIS... HIGH PRESSURE ALONG THE EAST COAST WILL KEEP A RELATIVELY COOL AIRMASS ACROSS MUCH OF THE REGION TODAY. A WEAK FRONTAL BOUNDARY ACROSS SOUTHWEST VIRGINIA INTO WESTERN NORTH CAROLINA WILL RETURN NORTHWARD THURSDAY AS HIGH PRESSURE ALOFT BUILDS ACROSS THE REGION. VERY WARM CONDITIONS THURSDAY AND FRIDAY UNDER THE UPPER RIDGE WILL GIVE WAY TO SHOWERS AND THUNDERSTORMS OVER THE WEEKEND AS AN UPPER TROUGH APPROACHES THE REGION FROM THE WEST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1130 AM EDT WEDNESDAY... REGIONAL WSR-88D LOOP SHOWED MAIN COMPLEX OF THUNDERSTORMS NORTH OF OUR REGION ACROSS NORTHERN VA AND WESTERN MD. THIS IS WHERE THE BEST INSTABILITY IS LOCATED NORTH OF FRONTAL BOUNDARY. SATELLITE IMAGES SHOWED LOW CLOUDS ERODING ACROSS OUR CWA. DECREASED CLOUD COVER FOR THIS AFTERNOON AND INCREASED TEMPERATURES AND HIGH TEMPERATURES FOR THIS AFTERNOON. HAVE A GOOD AFTERNOON. AS OF 943 AM EDT WEDNESDAY... SATELLITE LOOP SHOWED THAT LOW LEVEL CLOUDS MIXING OUT THIS MORNING...WITH THE RICHES CLOUDS ACROSS SOUTHERN PORTIONS OF CWA. ADJUSTED CLOUD COVER FOR THIS MORNING INTO THIS AFTERNOON WITH LATEST TRENDS. LOOKS LIKE THE NAM AND GFS ARE OVERDONE WITH CONVECTION THIS AFTERNOON FOR CWA. PREFER THE HRRR WITH STORMS STAYING TO THE NORTH OF OUR AREA. MATCHES UP NICELY WITH SWODY1 GENERAL THUNDERSTORM OUTLOOK FOR TODAY. THIS SEEM REASONABLE WITH UPPER RIDGE BUILDING INTO THE REGION FROM THE WEST...AND BAROCLINIC ZONE NORTHWARD TODAY. CAPPED ALOFT WAS QUITE HEALTHY ESPECIALLY ACROSS SOUTHERN PORTIONS OF CWA. WITH PATCHY CLOUDINESS...AND COOL WEDGE WILL HOLD WITH FORECAST HIGH TEMPERATURES FOR THIS AFTERNOON. MAY NEED TO RAISE HIGHS DEPENDING ON CLOUD COVER LATE THIS MORNING INTO THIS AFTERNOON. ONLY MINOR ADJUSTMENTS IN TEMPERATURES AND DEW POINTS IN ISC GRIDS. MORE CHANGES LATER.... AS OF 420 AM EDT WEDNESDAY... QUASI-STATIONARY FRONT OF THE PAST SEVERAL DAYS MOVED BACK WEST AGAIN TUESDAY EVENING...AND EARLY THIS MORNING WAS LOCATED FROM NEAR LWB-BLF-TNB. AS EXPECTED LOW CLOUDS ARE DEVELOPING EAST OF THE FRONT...ESPECIALLY IN UPSLOPE AREAS ALONG THE BLUE RIDGE FROM SIF-ROA-LYH. FAIRLY FAVORABLE WEDGE PATTERN WITH BUILDING RIDGE ALOFT AND SFC HIGH PRESSURE ANCHORED FROM QUEBEC SOUTHEASTWARD TO OFF THE DELMARVA PENINSULA. THUS...EXPECT MUCH OF THE CWA TO REMAIN MOSTLY CLOUDY AND RELATIVELY COOL TODAY WITH EASTERLY MARITIME FLOW. MOST AREAS WILL SEE HIGHS IN THE UPPER 60S TO LOWER 70S EAST OF THE ALLEGHANY FRONT...MID 70S ACROSS THE NC COUNTIES...APPROACHING 80 IN FAR SW VA/SOUTHERN WV...WHICH WILL EITHER REMAIN WEST OF THE WEDGE BOUNDARY OR MOVE BACK INTO THE WARM SECTOR DURING THE AFTERNOON. WITH RESPECT TO CONVECTION...THE CHANCE FOR SUCH IN OUR CWA IS DECREASING. WITH UPPER RIDGE BUILDING INTO THE REGION FROM THE WEST...BAROCLINIC ZONE WILL BE PUSHED NORTHWARD...AND TODAY SHOULD RESIDE FROM NORTHERN WV INTO NORTHERN VA. WITH WARMING TEMPS ALOFT AND A COOL STABLE LAYER AT THE SFC...EXPECT LITTLE IF ANY CONVECTION. IN THE FAR SW WHERE IT WILL BE MORE UNSTABLE IT WILL BE CAPPED ALOFT...SO NOTHING EXPECTED THERE EITHER. HOWEVER...A FEW SHOWERS OR SPRINKLES CANNOT BE TOTALLY RULED OUT...ESPECIALLY THROUGH MID-DAY...BETWEEN THE BLUE RIDGE AND THE ALLEGHANY FRONT ALONG-NORTH OF I-64...SUCH AS WE HAVE SEEN FROM TIME-TO-TIME OVERNIGHT. WITH ALL OF THESE FACTORS IN MIND...HAVE OPTED NOT TO MENTION TSRA FOR THE NEAR TERM. MODEL INSTABILITY IS GROSSLY OVER ESTIMATED AND MY THINKING IS CONSISTENT WITH SPCS LACK OF EVEN A GENERAL THUNDER AREA FOR OUR CWA TODAY. && .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... AS OF 330 AM EDT WEDNESDAY... THURSDAY IS SHAPING UP TO BE DRY AND VERY WARM AS AN UPPER LEVEL RIDGE PASSES ACROSS THE APPALACHIAN CHAIN. THE COMBINATION OF VERY WARM AIR BUILDING IN FROM THE SOUTHWEST...COMBINED WITH ABUNDANT SUNSHINE AND GENERAL DOWNSLOPE WIND FLOW WILL ALLOW AFTERNOON TEMPERATURES TO TOP OUT JUST ABOVE 90 IN A FEW AREAS ACROSS THE SOUTHSIDE...WHILE THE MOUNTAINS CAN EXPECT MID 80S TO UPPER 70S...WITH COOLER TEMPERATURES AT HIGHER ELEVATIONS. A STRONG LAYER OF STABLE AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL KEEP SHOWERS AND THUNDERSTORMS AT BAY. SOUTHWESTERLY FLOW WILL ALSO RESULT IN WARM OVERNIGHT LOWS...WITH MID 50S TO LOW 60S EXPECTED AREAWIDE. UPPER RIDGING WILL SHIFT EAST ON FRIDAY...RESULTING IN SLIGHTLY MORE INSTABILITY...PARTICULARLY DURING LATE AFTERNOON AND EARLY EVENING. CONTINUED SOUTHWESTERLY FLOW WILL RESULT IN ANOTHER WARM DAY. HOWEVER...WITH INCREASING CLOUD COVER AHEAD OF ANOTHER APPROACHING FRONT...EXPECT FRIDAY AFTERNOON HIGHS TO BE SLIGHTLY COOLER THAN THOSE ON THURSDAY. STILL...WILL BE LOOKING AT 80S FOR A MAJORITY OF THE FORECAST REGION. EXPECT A FEW SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE MOUNTAINS WITH MAXIMUM DAYTIME HEATING. INSTABILITY APPEARS TO BE LIMITED...AND WITH ONLY VERY WEAK UPPER LEVEL DISTURBANCES EXPECTED...CONVECTION SHOULD REMAIN SPOTTY AND DISORGANIZED. LONG RANGE MODELS APPEAR IN BETTER AGREEMENT THIS MORNING THAT UPPER LEVEL RIDGING ACROSS THE EAST WILL GIVE WAY TO A MORE ZONAL WEST TO EAST FLOW ON SATURDAY MORNING. THE ZONAL FLOW WILL CAUSE THE APPROACHING COLD FRONT TO LOSE ITS COLD AIR PUSH...FORCING IT TO STALL WEST OF OUR AREA. MINOR UPPER LEVEL DISTURBANCES WILL PASS ACROSS THE REGION THROUGH THE DAY...RESULTING IN ROUNDS OF SHOWER AND SOME THUNDERSTORM ACTIVITY...WITH THE BRUNT OF THE RAINFALL OCCURRING ACROSS THE MOUNTAINS. REGARDLESS...INSTABILITY APPEARS TO BE MARGINAL...AND THE POTENTIAL FOR STRONG THUNDERSTORMS WILL BE REMOTE. INCREASED CLOUD COVER AND SPOTTY RAINFALL WILL MAKE FOR COOLER AFTERNOON TEMPERATURES...WITH HIGHS REACHING INTO THE 70S MOST LOCATIONS...POSSIBLY TOUCHING 80 AROUND DANVILLE. && .LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 330 PM EDT TUESDAY... VARIABILITY IN THE MODELS LEADS TO A LOW CONFIDENCE FORECAST FOR SUNDAY THROUGH TUESDAY. THE GFS FAVORS A MORE ZONAL FLOW ALOFT NEXT WEEK VS. A MORE AMPLIFIED ECMWF SOLUTION. FOR SUNDAY...THE GFS INDICATES A LOW AMPLITUDE RIDGE BUILDING IN FROM THE WEST...WITH ANOTHER FRONT COMING THROUGH ABOUT TUESDAY EVENING. THE ECMWF IS MORE AMPLIFIED WITH THE RIDGING...CAUSING THE SURFACE FRONT TO GET CAUGHT UNDERNEATH THE RIDGE AND HOLD WEST OF OUR AREA. THIS RESULTS IN A WETTER SOLUTION OVERALL FOR THE LONG TERM PERIOD. SINCE THE CURRENT PATTERN FAVORS A MORE AMPLIFIED SOLUTION WILL ENTERTAIN A FORECAST CLOSER TO THE ECMWF. AS SUCH TRENDED THE FORECAST CLOUDIER AND COOLER TO START THE WEEK...TEMPERATURES MONDAY AND TUESDAY WILL BE CLOSER TO NORMAL ALONG WITH A CHANCE OF SHOWERS. BY MID WEEK...FLOW ALOFT SHOULD BECOME SOUTHWEST WITH ANOTHER WARM SURGE PRIOR TO ANY FRONTAL PASSAGE IN THE LATE TUESDAY...THURSDAY TIME FRAME. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... AS OF 745 AM EDT WEDNESDAY... LOW CLOUDS DEVELOPED AS EXPECTED...MAINLY EAST OF THE ALLEGHANY FRONT. UNCERTAINTY REMAINS CONCERNING DURATION OF LOW CLOUDS AND ASSOCIATED MVFR TO IFR CIGS AND MVFR VSBYS. BACK DOOR FRONT SHIFTED BACK TO THE WEST AFTER SUNSET TUESDAY...AND NOW APPEARS TO BE BACK INTO FAR SW VA NEAR MKJ. E-ENE WINDS EVIDENT ACROSS MOST OF THE CWA. ALL MODELS POINT TOWARD THE COOLER...EASTERLY MARITIME FLOW DOMINATING MUCH OF THE DAYTIME TODAY AS OPPOSED TO YESTERDAY. THIS WILL OCCUR AS FAIRLY TYPICAL WEDGE SUPPORTING PATTERN OF UPPER RIDGE BUILDING OVER SFC WEDGE/COLD AIR DAMMING. CIGS IN LOW CLOUD AREAS GENERALLY IN THE 015-040 RANGE...SO A VARIETY OF MVFR TO VFR. SOME IFR CIGS NOTED ACROSS NORTH CENTRAL NC. LOWEST CIGS RIGHT ALONG UPSLOPE AREAS OF BLUE RIDGE...WITH AREAS FURTHER EAST...E.G. LYH/DAN...SEEING MOSTLY VFR CIGS. AMENDMENTS/ADJUSTMENTS WILL LIKELY CONTINUE THROUGH THE MORNING. BY AFTERNOON...EXPECT GRADUAL IMPROVEMENT OF CIGS...WITH MOSTLY VFR CONDITIONS WEST OF THE ALLEGHANY FRONT. MID-CLOUD DECK WILL LIFT NORTH THROUGH THE DAY WITH THE WARM FRONT. VSBYS SHOULD REMAIN MOSTLY VFR FROM THIS POINT THROUGH THE DAY. AS WEDGE CONTINUES TO ERODE OVERNIGHT...EXPECT RETURN TO VFR CONDITIONS ALL AREAS...ALTHOUGH SOME MVFR BR MAY DEVELOP LATE NIGHT/EARLY THU MORNING AT LWB/LYH/BCB. WINDS TODAY SHOULD GENERALLY BE ESE-SE MOST SITES AT SPEEDS OF 5-8KTS...BECOMING CALM/VRB03KT AROUND 00Z THU...THEN SW AFTER 12Z THU. LOW TO MEDIUM CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD. MEDIUM CONFIDENCE IN VSBYS THROUGH 15Z...THEN HIGH CONFIDENCE IN VFR VSBYS. HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION DISCUSSION... THURSDAY...THE FRONT LIFTS TO THE NORTH WITH WARMER AIR ALOFT PUTTING A CAP ON ANY CONVECTION UNDER VFR CU FIELDS. BY LATE FRIDAY A COLD FRONT WILL APPROACH FROM THE WEST...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS DURING THE EVENING. BETTER CHANCE FOR SUB-VFR AT TIMES SAT AFTERNOON/EVENING WITH THE FRONT SLOWLY MOVING EAST AND DEEPER MOISTURE IN PLACE. BOUNDARY MAY WASH OUT UPON CROSSING THE AREA BY SUNDAY WITH MAINLY VFR CONDITIONS EXPECTED OUTSIDE OF OCNL MVFR IN SCATTERED AFTERNOON/EVENING SHRA. && .CLIMATE... HIGH TEMPERATURE RECORDS IN THE MOUNTAINS ARE IN JEOPARDY THURSDAY. MAY GET CLOSE IN THE EAST. CURRENT RECORDS FOR MAY 8TH... ROANOKE......94/1940 LYNCHBURG....94/1940 DANVILLE.....92/1986 BLACKSBURG...85/2000 BLUEFIELD....84/2004 LEWISBURG....82/2000 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...RAB/KK NEAR TERM...KK/RAB SHORT TERM...NF LONG TERM...NF/PM AVIATION...JH/RAB CLIMATE...PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
944 AM EDT WED MAY 7 2014 .SYNOPSIS... HIGH PRESSURE ALONG THE EAST COAST WILL KEEP A RELATIVELY COOL...CLOUDY AIR MASS ACROSS MUCH OF THE REGION TODAY. A WEAK FRONTAL BOUNDARY ACROSS SOUTHWEST VIRGINIA INTO WESTERN NORTH CAROLINA WILL RETURN NORTHWARD THURSDAY AS HIGH PRESSURE ALOFT BUILDS ACROSS THE REGION. VERY WARM CONDITIONS THURSDAY AND FRIDAY UNDER THE UPPER RIDGE WILL GIVE WAY TO SHOWERS AND THUNDERSTORMS OVER THE WEEKEND AS AN UPPER TROUGH APPROACHES THE REGION FROM THE WEST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 943 AM EDT WEDNESDAY... SATELLITE LOOP SHOWED THAT LOW LEVEL CLOUDS MIXING OUT THIS MORNING...WITH THE RICHES CLOUDS ACROSS SOUTHERN PORTIONS OF CWA. ADJUSTED CLOUD COVER FOR THIS MORNING INTO THIS AFTERNOON WITH LATEST TRENDS. LOOKS LIKE THE NAM AND GFS ARE OVERDONE WITH CONVECTION THIS AFTERNOON FOR CWA. PREFER THE HRRR WITH STORMS STAYING TO THE NORTH OF OUR AREA. MATCHES UP NICELY WITH SWODY1 GENERAL THUNDERSTORM OUTLOOK FOR TODAY. THIS SEEM REASONABLE WITH UPPER RIDGE BUILDING INTO THE REGION FROM THE WEST...AND BAROCLINIC ZONE NORTHWARD TODAY. CAPPED ALOFT WAS QUITE HEALTHY ESPECIALLY ACROSS SOUTHERN PORTIONS OF CWA. WITH PATCHY CLOUDINESS...AND COOL WEDGE WILL HOLD WITH FORECAST HIGH TEMPERATURES FOR THIS AFTERNOON. MAY NEED TO RAISE HIGHS DEPENDING ON CLOUD COVER LATE THIS MORNING INTO THIS AFTERNOON. ONLY MINOR ADJUSTMENTS IN TEMPERATURES AND DEW POINTS IN ISC GRIDS. MORE CHANGES LATER.... AS OF 420 AM EDT WEDNESDAY... QUASI-STATIONARY FRONT OF THE PAST SEVERAL DAYS MOVED BACK WEST AGAIN TUESDAY EVENING...AND EARLY THIS MORNING WAS LOCATED FROM NEAR LWB-BLF-TNB. AS EXPECTED LOW CLOUDS ARE DEVELOPING EAST OF THE FRONT...ESPECIALLY IN UPSLOPE AREAS ALONG THE BLUE RIDGE FROM SIF-ROA-LYH. FAIRLY FAVORABLE WEDGE PATTERN WITH BUILDING RIDGE ALOFT AND SFC HIGH PRESSURE ANCHORED FROM QUEBEC SOUTHEASTWARD TO OFF THE DELMARVA PENINSULA. THUS...EXPECT MUCH OF THE CWA TO REMAIN MOSTLY CLOUDY AND RELATIVELY COOL TODAY WITH EASTERLY MARITIME FLOW. MOST AREAS WILL SEE HIGHS IN THE UPPER 60S TO LOWER 70S EAST OF THE ALLEGHANY FRONT...MID 70S ACROSS THE NC COUNTIES...APPROACHING 80 IN FAR SW VA/SOUTHERN WV...WHICH WILL EITHER REMAIN WEST OF THE WEDGE BOUNDARY OR MOVE BACK INTO THE WARM SECTOR DURING THE AFTERNOON. WITH RESPECT TO CONVECTION...THE CHANCE FOR SUCH IN OUR CWA IS DECREASING. WITH UPPER RIDGE BUILDING INTO THE REGION FROM THE WEST...BAROCLINIC ZONE WILL BE PUSHED NORTHWARD...AND TODAY SHOULD RESIDE FROM NORTHERN WV INTO NORTHERN VA. WITH WARMING TEMPS ALOFT AND A COOL STABLE LAYER AT THE SFC...EXPECT LITTLE IF ANY CONVECTION. IN THE FAR SW WHERE IT WILL BE MORE UNSTABLE IT WILL BE CAPPED ALOFT...SO NOTHING EXPECTED THERE EITHER. HOWEVER...A FEW SHOWERS OR SPRINKLES CANNOT BE TOTALLY RULED OUT...ESPECIALLY THROUGH MID-DAY...BETWEEN THE BLUE RIDGE AND THE ALLEGHANY FRONT ALONG-NORTH OF I-64...SUCH AS WE HAVE SEEN FROM TIME-TO-TIME OVERNIGHT. WITH ALL OF THESE FACTORS IN MIND...HAVE OPTED NOT TO MENTION TSRA FOR THE NEAR TERM. MODEL INSTABILITY IS GROSSLY OVER ESTIMATED AND MY THINKING IS CONSISTENT WITH SPCS LACK OF EVEN A GENERAL THUNDER AREA FOR OUR CWA TODAY. && .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... AS OF 330 AM EDT WEDNESDAY... THURSDAY IS SHAPING UP TO BE DRY AND VERY WARM AS AN UPPER LEVEL RIDGE PASSES ACROSS THE APPALACHIAN CHAIN. THE COMBINATION OF VERY WARM AIR BUILDING IN FROM THE SOUTHWEST...COMBINED WITH ABUNDANT SUNSHINE AND GENERAL DOWNSLOPE WIND FLOW WILL ALLOW AFTERNOON TEMPERATURES TO TOP OUT JUST ABOVE 90 IN A FEW AREAS ACROSS THE SOUTHSIDE...WHILE THE MOUNTAINS CAN EXPECT MID 80S TO UPPER 70S...WITH COOLER TEMPERATURES AT HIGHER ELEVATIONS. A STRONG LAYER OF STABLE AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL KEEP SHOWERS AND THUNDERSTORMS AT BAY. SOUTHWESTERLY FLOW WILL ALSO RESULT IN WARM OVERNIGHT LOWS...WITH MID 50S TO LOW 60S EXPECTED AREAWIDE. UPPER RIDGING WILL SHIFT EAST ON FRIDAY...RESULTING IN SLIGHTLY MORE INSTABILITY...PARTICULARLY DURING LATE AFTERNOON AND EARLY EVENING. CONTINUED SOUTHWESTERLY FLOW WILL RESULT IN ANOTHER WARM DAY. HOWEVER...WITH INCREASING CLOUD COVER AHEAD OF ANOTHER APPROACHING FRONT...EXPECT FRIDAY AFTERNOON HIGHS TO BE SLIGHTLY COOLER THAN THOSE ON THURSDAY. STILL...WILL BE LOOKING AT 80S FOR A MAJORITY OF THE FORECAST REGION. EXPECT A FEW SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE MOUNTAINS WITH MAXIMUM DAYTIME HEATING. INSTABILITY APPEARS TO BE LIMITED...AND WITH ONLY VERY WEAK UPPER LEVEL DISTURBANCES EXPECTED...CONVECTION SHOULD REMAIN SPOTTY AND DISORGANIZED. LONG RANGE MODELS APPEAR IN BETTER AGREEMENT THIS MORNING THAT UPPER LEVEL RIDGING ACROSS THE EAST WILL GIVE WAY TO A MORE ZONAL WEST TO EAST FLOW ON SATURDAY MORNING. THE ZONAL FLOW WILL CAUSE THE APPROACHING COLD FRONT TO LOSE ITS COLD AIR PUSH...FORCING IT TO STALL WEST OF OUR AREA. MINOR UPPER LEVEL DISTURBANCES WILL PASS ACROSS THE REGION THROUGH THE DAY...RESULTING IN ROUNDS OF SHOWER AND SOME THUNDERSTORM ACTIVITY...WITH THE BRUNT OF THE RAINFALL OCCURRING ACROSS THE MOUNTAINS. REGARDLESS...INSTABILITY APPEARS TO BE MARGINAL...AND THE POTENTIAL FOR STRONG THUNDERSTORMS WILL BE REMOTE. INCREASED CLOUD COVER AND SPOTTY RAINFALL WILL MAKE FOR COOLER AFTERNOON TEMPERATURES...WITH HIGHS REACHING INTO THE 70S MOST LOCATIONS...POSSIBLY TOUCHING 80 AROUND DANVILLE. && .LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 330 PM EDT TUESDAY... VARIABILITY IN THE MODELS LEADS TO A LOW CONFIDENCE FORECAST FOR SUNDAY THROUGH TUESDAY. THE GFS FAVORS A MORE ZONAL FLOW ALOFT NEXT WEEK VS. A MORE AMPLIFIED ECMWF SOLUTION. FOR SUNDAY...THE GFS INDICATES A LOW AMPLITUDE RIDGE BUILDING IN FROM THE WEST...WITH ANOTHER FRONT COMING THROUGH ABOUT TUESDAY EVENING. THE ECMWF IS MORE AMPLIFIED WITH THE RIDGING...CAUSING THE SURFACE FRONT TO GET CAUGHT UNDERNEATH THE RIDGE AND HOLD WEST OF OUR AREA. THIS RESULTS IN A WETTER SOLUTION OVERALL FOR THE LONG TERM PERIOD. SINCE THE CURRENT PATTERN FAVORS A MORE AMPLIFIED SOLUTION WILL ENTERTAIN A FORECAST CLOSER TO THE ECMWF. AS SUCH TRENDED THE FORECAST CLOUDIER AND COOLER TO START THE WEEK...TEMPERATURES MONDAY AND TUESDAY WILL BE CLOSER TO NORMAL ALONG WITH A CHANCE OF SHOWERS. BY MID WEEK...FLOW ALOFT SHOULD BECOME SOUTHWEST WITH ANOTHER WARM SURGE PRIOR TO ANY FRONTAL PASSAGE IN THE LATE TUESDAY...THURSDAY TIME FRAME. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... AS OF 745 AM EDT WEDNESDAY... LOW CLOUDS DEVELOPED AS EXPECTED...MAINLY EAST OF THE ALLEGHANY FRONT. UNCERTAINTY REMAINS CONCERNING DURATION OF LOW CLOUDS AND ASSOCIATED MVFR TO IFR CIGS AND MVFR VSBYS. BACK DOOR FRONT SHIFTED BACK TO THE WEST AFTER SUNSET TUESDAY...AND NOW APPEARS TO BE BACK INTO FAR SW VA NEAR MKJ. E-ENE WINDS EVIDENT ACROSS MOST OF THE CWA. ALL MODELS POINT TOWARD THE COOLER...EASTERLY MARITIME FLOW DOMINATING MUCH OF THE DAYTIME TODAY AS OPPOSED TO YESTERDAY. THIS WILL OCCUR AS FAIRLY TYPICAL WEDGE SUPPORTING PATTERN OF UPPER RIDGE BUILDING OVER SFC WEDGE/COLD AIR DAMMING. CIGS IN LOW CLOUD AREAS GENERALLY IN THE 015-040 RANGE...SO A VARIETY OF MVFR TO VFR. SOME IFR CIGS NOTED ACROSS NORTH CENTRAL NC. LOWEST CIGS RIGHT ALONG UPSLOPE AREAS OF BLUE RIDGE...WITH AREAS FURTHER EAST...E.G. LYH/DAN...SEEING MOSTLY VFR CIGS. AMENDMENTS/ADJUSTMENTS WILL LIKELY CONTINUE THROUGH THE MORNING. BY AFTERNOON...EXPECT GRADUAL IMPROVEMENT OF CIGS...WITH MOSTLY VFR CONDITIONS WEST OF THE ALLEGHANY FRONT. MID-CLOUD DECK WILL LIFT NORTH THROUGH THE DAY WITH THE WARM FRONT. VSBYS SHOULD REMAIN MOSTLY VFR FROM THIS POINT THROUGH THE DAY. AS WEDGE CONTINUES TO ERODE OVERNIGHT...EXPECT RETURN TO VFR CONDITIONS ALL AREAS...ALTHOUGH SOME MVFR BR MAY DEVELOP LATE NIGHT/EARLY THU MORNING AT LWB/LYH/BCB. WINDS TODAY SHOULD GENERALLY BE ESE-SE MOST SITES AT SPEEDS OF 5-8KTS...BECOMING CALM/VRB03KT AROUND 00Z THU...THEN SW AFTER 12Z THU. LOW TO MEDIUM CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD. MEDIUM CONFIDENCE IN VSBYS THROUGH 15Z...THEN HIGH CONFIDENCE IN VFR VSBYS. HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION DISCUSSION... THURSDAY...THE FRONT LIFTS TO THE NORTH WITH WARMER AIR ALOFT PUTTING A CAP ON ANY CONVECTION UNDER VFR CU FIELDS. BY LATE FRIDAY A COLD FRONT WILL APPROACH FROM THE WEST...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS DURING THE EVENING. BETTER CHANCE FOR SUB-VFR AT TIMES SAT AFTERNOON/EVENING WITH THE FRONT SLOWLY MOVING EAST AND DEEPER MOISTURE IN PLACE. BOUNDARY MAY WASH OUT UPON CROSSING THE AREA BY SUNDAY WITH MAINLY VFR CONDITIONS EXPECTED OUTSIDE OF OCNL MVFR IN SCATTERED AFTERNOON/EVENING SHRA. && .CLIMATE... HIGH TEMPERATURE RECORDS IN THE MOUNTAINS ARE IN JEOPARDY THURSDAY. MAY GET CLOSE IN THE EAST. CURRENT RECORDS FOR MAY 8TH... ROANOKE......94/1940 LYNCHBURG....94/1940 DANVILLE.....92/1986 BLACKSBURG...85/2000 BLUEFIELD....84/2004 LEWISBURG....82/2000 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...RAB NEAR TERM...KK/RAB SHORT TERM...NF LONG TERM...NF/PM AVIATION...JH/RAB CLIMATE...PM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
655 AM CDT WED MAY 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 425 AM CDT WED MAY 7 2014 AT 3 AM...WATCHING 2 AREAS OF CONVECTION. THE FIRST IS LOCATED OVER EAST CENTRAL WISCONSIN. MEANWHILE THE OTHER ONE IS LOCATED BETWEEN SIOUX FALLS SOUTH DAKOTA AND FAIRMONT MINNESOTA. BOTH OF THESE ARE LOCATED ON THE EASTERN EDGE STRONG 700 MB MOISTURE CONVERGENT AREA. IN ADDITION...THEY ARE LOCATED ONE THE NORTHERN PERIPHERY OF 1000 J/KG MOST UNSTABLE CAPE. THE ARW...NMM...HOP WRF AND SPC WRF SUGGEST THAT THE LATTER AREA OF CONVECTION WILL MOVE EAST ALONG THE INTERSTATE 90 CORRIDOR THIS MORNING. EARLIER IN THE NIGHT THE HRRR SUGGESTED A SIMILAR SCENARIO...BUT WITH ITS LATEST RUN IT HAS BACKED AWAY FROM THIS SOLUTION. HOWEVER THIS SCENARIO DOES NOT MAKE A LOT OF SENSE...SO BACKED AWAY FROM FOLLOWING IT. TRENDED THE PRECIPITATION FORECAST FOR TODAY TOWARD A BLEND OF ARW...NMM...HOP WRF AND SPC WRF. HOWEVER I AM A BIT CONCERNED THAT AS IT MOVES EAST THAT THE NOCTURNAL JET WILL WEAKEN AND THAT THE CONVECTION COULD DISSIPATE BEFORE IT GETS INTO OUR AREA. IF THE CONVECTION DOES HAPPEN TO GET INTO OUR AREA...THE SPC RAP SUGGESTS THAT EFFECTIVE SHEAR WILL INCREASE OVER 40 KNOTS THROUGH 07.14Z. THIS COULD RESULT IN THE DEVELOPMEMT OF SOME ELEVATED SUPER CELLS. WE WILL HAVE TO MONITOR THIS OVER THE NEXT COUPLE OF HOURS. FOR LATER THIS MORNING AND AFTERNOON...MANY OF THE MESO MODELS AND AND NAM SUGGEST THAT THE AREA WILL REMAIN DRY. THIS IS A RESULT OF AN ELEVATED MIXED LAYER BEING BROUGHT ISENTROPICALLY OFF OF THE SOUTHERN PLAINS. THIS LAYER FORMS A STRONG 800 TO 600 MB CAP ACROSS THE FORECAST AREA. MEANWHILE THE GFS CONTINUES TO TRY AND DEVELOP STRATIFORM PRECIPITATION BELOW THE CAP. THIS LOOKS VERY UNLIKELY BECAUSE ITS SATURATED THE AIR MASS BELOW 800 MB TOO MUCH. DUE TO THIS...STAYED WITH A DRY FORECAST FOR THE TIME PERIOD. TONIGHT...MANY OF DETERMINISTIC RUNS ARE GENERATING PRECIPITATION ACROSS MUCH OF THE FORECAST AREA. HOWEVER BUFKIT SOUNDINGS CONTINUE TO SHOW A FAIRLY STRONG CAP ALONG AND SOUTH OF INTERSTATE 94. THIS IS GOOD AGREEMENT WITH WHAT SHOWS UP IN THE ARW AND SPC WRF. DUE TO THIS...WENT WITH MUCH LOWER POPS THAN WHAT NORMALLY WOULD BE EXPECTED SOUTH OF INTERSTATE 94. IF THUNDERSTORMS DID DEVELOP...IT LOOKS TO BE SO HIGH /BASES OF 2 TO 3 KM/ THAT YOUR SHEAR IS GREATLY DECREASED TO LESS 25 KNOTS...SO THERE WILL NOT BE SUPERCELLS. HOWEVER THE CAPE PROFILE IS MUCH FATTER THAN THIS MORNING AND THIS COULD POTENTIALLY RESULT IN SOME LARGE HAIL. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 425 AM CDT WED MAY 7 2014 ON THURSDAY AND THURSDAY NIGHT...THE 07.00Z MODELS CONTINUE TO SHOW THAT A PLUME OF SUBTROPICAL MOISTURE WILL SURGE NORTHWARD AHEAD OF THE LONG WAVE TROUGH. EMBEDDED WAVES IN THIS FLOW WILL RESULT IN SHOWERS AND THUNDERSTORMS WHICH WILL USE UP MUCH OF THE CAPE PRIOR TO THE ARRIVAL OF A MUCH MORE FAVORABLE SHEAR PROFILE. DUE TO THIS...STILL THINKING THAT THE BEST SEVERE WEATHER THREAT WILL REMAIN WEST OF INTERSTATE 35. WITH THIS PLUME NOT ARRIVING UNTIL MID MORNING...LOWERED THE PRECIPITATION PROBABILITIES BETWEEN 08.12Z AND 08.15Z. FROM SATURDAY NIGHT THROUGH TUESDAY...A SERIES OF SHORT WAVE TROUGHS WILL EJECTED OUT OF THE LONG WAVE OVER THE WESTERN UNITED STATES. THIS WILL BRING ROUND OF SHOWERS AND THUNDERSTORMS INTO THE AREA. WITH STILL SOME TIMING DIFFERENCES AND SUBTLE DIFFERENCES IN THE MODELS...STAYED WITH THE MODEL CONSENSUS. TOWARD THE MIDDLE OF NEXT WEEK...IT LOOKS LIKE THERE WILL BE A PATTERN SHIFT AS THE UPPER LEVEL FLOW BECOMES NORTHWEST AND WEST ACROSS THE EASTERN UNITED STATES. LOOKS LIKE HIGHS MAY RANGE FROM THE UPPER 40S TO MID 50S...AND LOWS WILL RANGE FROM THE MID 30S TO MID 40S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 655 AM CDT WED MAY 7 2014 THROUGH 07.1330Z STRONG TO SEVERE THUNDERSTORMS WILL AFFECT KRST. THE MAIN THREAT WITH THESE THUNDERSTORMS WILL BE LARGE HAIL. WITH THE WEAKENING OF THE LOW LEVEL JET...EXPECT THE SHOWERS AND THUNDERSTORMS ALONG AND NORTH OF INTERSTATE 90 TO DISSIPATE BY 07.15Z. WHILE BOTH THE GFS AND NAM SOUNDINGS SUGGEST MVFR CEILINGS THROUGH TONIGHT. THE RAP SOUNDINGS SHOW THAT CEILINGS WILL REMAIN VFR. LOOKING AT CEILINGS AROUND THE REGION...THE RAP IS VERIFYING THE BEST...SO TRENDED THE TAFS THAT WAY. FOR TONIGHT...THE MESO MODELS SUGGEST THAT ADDITIONAL SHOWERS AND THUNDERSTORMS WILL FIRE WELL NORTH OF THE TAF SITES...THUS... WENT DRY WITH VFR CEILINGS. && .HYDROLOGY... ISSUED AT 425 AM CDT WED MAY 7 2014 FLOODING CONTINUES ALONG THE MAIN STEM OF THE MISSISSIPPI RIVER...WITH LOCATIONS CRESTING FROM NORTH MCGREGOR. SHOWERS AND THUNDERSTORMS ON THURSDAY AND THURSDAY NIGHT WILL PRODUCE ANYWHERE FROM A HALF INCH TO ONE INCH. THIS WILL LIKELY SLOW THE FALL FOR LOCATIONS NORTH OF MCGREGOR...AND MAY INCREASE CRESTS SLIGHTLY SOUTH OF MCGREGOR. CHECK OUT THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...BOYNE HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
631 AM MDT WED MAY 7 2014 .UPDATE... ISSUED AT 602 AM MDT WED MAY 7 2014 WILL ADD SOME FOG TO THE FORECAST GRIDS THROUGH MID MORNING. FOG HAS FORMED MAINLY ALONG THE LEADING EDGE OF A COLD FRONT THIS MORNING...GENERALLY FROM LARAMIE TO CHEYENNE TO KIMBALL. SOME LOCALLY DENSE FOR IS POSSIBLE. THE FOG SHOULD LIFT INTO A STRATUS DECK BY MID MORNING. ALSO OF NOTE IS THE 06Z MODEL RUNS. BOTH THE NAM AND GFS PUSH THE SURFACE COLD FRONT ABOUT 30 TO 40 MILES FARTHER SOUTH THAN THE 00Z RUNS. THE IMPLICATIONS OF THIS ARE MANY. FIRST...THIS WILL SHIFT THE SEVERE THREAT SLIGHTLY SOUTHWARD...AND WILL GREATLY REDUCE THE THREAT FOR TORNADIC ACTIVITY IN THE CWA THIS AFTERNOON. WILL STILL HAVE TO KEEP AN EYE ON THE LOCATION OF THE SURFACE FRONT THIS AFTERNOON...BUT LOOKS LIKE THE MAIN TORNADO THREAT WILL BE JUST SOUTH OF THE NEBRASKA BORDER. THE OTHER IMPACT WILL BE ON SNOW AMOUNTS. A DEEPER COLD BOUNDARY LAYER IS MORE FAVORABLE FOR RAIN CHANGING TO SNOW TONIGHT. IT MAY BE JUST COLD ENOUGH GIVEN HIGH PRECIPITATION RATES FOR A GOOD DEAL OF SNOW ACCUMULATIONS...WITH SNOW ADVISORIES AND WINTER STORM WARNINGS A MUCH GREATER LIKELIHOOD TONIGHT INTO THURSDAY MORNING. MODELS ARE ALSO SLOWER WITH THE DEPARTURE OF THIS SYSTEM WITH COULD ALSO INCREASE SNOW ACCUMULATIONS. LATEST OBSERVATIONS ACROSS NORTHEAST WYOMING SHOWING TEMPERATURES IN THE LOWER TO MIDDLE 30S...SO THE 06Z MODEL RUNS MAY BE ON TO SOMETHING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 445 AM MDT WED MAY 7 2014 WOW...LOTS OF WEATHER CONCERNS TODAY...FROM RIVER FLOODING TO FLASH FLOODING...TO SEVERE THUNDERSTORMS WITH TORNADOES POSSIBLE... TO THE POTENTIAL FOR HEAVY SNOW TONIGHT. THIS MORNING WILL BE RELATIVELY QUIET WITH SHOWERS DEVELOPING AS AN UPPER LEVEL SYSTEM APPROACHES AND COULD SEE A FEW THUNDERSTORMS BY LATER THIS MORNING. THE MAIN CHANCES FOR THUNDERSTORMS WILL HOLD OFF UNTIL THIS AFTERNOON. THERE IS A HIGH PROBABILITY FOR SOME OF THESE THUNDERSTORMS TO BECOME SEVERE...MAINLY OVER FAR SOUTHEAST WYOMING AND INTO NEBRASKA PANHANDLE. OF COURSE ALL THIS IS PREDICATED ON THE EXACT TRACK OF THE UPPER LEVEL LOW. AT THIS TIME IT APPEARS THERE WILL BE SUFFICIENT UPPER LEVEL FORCING AND MID LEVEL INSTABILITY FOR SEVERE THUNDERSTORMS. INTO THE SOUTHERN NEBRASKA PANHANDLE...MODELS SHOWING MOST UNSTABLE CAPE VALUES 2000 J/KG ALONG AND JUST NORTH OF A STALLED FRONTAL BOUNDARY. ALSO LOOKING AT 50 TO 60 KTS OF BULK SHEAR WHICH IS MORE THAN ENOUGH FOR ROTATING SUPERCELL THUNDERSTORMS. ASSUMING THE FRONT IS LOCATED NEAR THE INTERSTATE 80 CORRIDOR...SHOULD SEE STORMS FIRE NEAR THE BOUNDARY AND THEN LIFT NORTHWARD UNDER STRONG SOUTHERN MIDLEVEL WINDS. NOT 100 PERCENT CONFIDENT ON THE EXACT LOCATION OF THE FRONT...BUT IT SHOULD BE BETWEEN INTERSTATE 80 AND THE COLORADO BORDER. THERE IS THE POSSIBILITY FOR TORNADIC ACTIVITY ALONG THIS FRONTAL BOUNDARY FROM ABOUT MID AFTERNOON INTO EARLY EVENING. AIR TEMPERATURES WILL BE RATHER COOL...BUT THAT WILL NOT NECESSARILY PRECLUDE TORNADO DEVELOPMENT. STRONG LOW LEVEL SHEAR AND LIFTED CONDENSATION LEVELS ONLY A FEW THOUSAND FEET AGL ARE FAVORABLE FOR TORNADIC DEVELOPMENT. THE TORNADO THREAT WILL BE CONFINED TO AREAS ALONG AND NEAR THE BOUNDARY...MAINLY BETWEEN PINE BLUFF TO KIMBALL TO SIDNEY. ALSO WORTH MENTIONING THE THE POTENTIAL FOR VERY LARGE HAIL. THE STORM PREDICATION CENTER HAS HATCHED HAIL FOR STONES UP TO 2 INCHES IN DIAMETER. THIS SEEMS VERY REASONABLE GIVEN MIDLEVEL CAPE VALUES AND SHEAR PARAMETERS. SHOULD CAPE VALUES END UP BEING MUCH HIGHER...BASEBALL OR LARGER HAIL WOULD COME INTO PLAY. ANOTHER THING TO CONSIDER IS FREEZING LEVELS ARE LOW...SO FALLING HAIL WILL NOT SEE MUCH MELTING. FOR FLASH FLOOD POTENTIAL IN THE SOUTHERN NEBRASKA PANHANDLE LATER TODAY... SEE THE HYDROLOGY DISCUSSION BELOW. LATER TONIGHT THE ATTENTION TURNS TO THE POTENTIAL FOR SNOW...AND POSSIBILITY HEAVY SNOW. CONFIDENCE NOT HIGH WITH THE CURRENT SNOW FORECAST AS THERE AREA MORE VARIABLES AT PLAY WITH THIS SPRING STORM SYSTEM. WHERE AND HOW MUCH SNOW FALLS WILL BE LARGELY DEPENDENT ONLY A FEW DEGREES DIFFERENCE IN ACTUALLY AIR TEMPERATURES...AND DEPENDENT ON PRECIPITATION RATES. MODELS HAVE TRENDED SLIGHTLY COLDER...WHICH MAKES THE POTENTIAL FOR HEAVY SNOW A GREATER POSSIBILITY...EVEN INTO THE PLAINS IN THE NEBRASKA PANHANDLE. MODELS SHOWING A PERIOD OF MODERATE RAIN ON THE BACKSIDE OF THE AREA OF LOW PRESSURE. THIS PRECIPITATION COULD EASILY WETBULB DOWN TO THE POINT WHERE SNOW ACCUMULATES AS RATES OF AN INCH OR MORE PER HOUR. THE WARM GROUND WILL INITIALLY MELT MUCH OF THE SNOW...BUT WITH SEVERAL HOURS OF HIGH SNOW RATES...SOME PLACE CERTAINLY COULD PUSH SNOW ADVISORY LEVELS...AND NOT DISCOUNTING WARNING CRITERIA BEING REACHED AT A FEW LOCATIONS. GIVEN LARGE UNCERTAINTY AND WITH THE THREAT FOR SEVERE WEATHER INTO EARLY THIS EVENING...DID NOT ISSUE ANY HEADLINES. WILL HAVE TO SEE WHAT WHAT THE 12 MODEL RUNS SHOW...BUT VERY WELL MAY NEED WINTER WEATHER HEADLINES AT SOME POINT. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 330 AM MDT WED MAY 7 2014 UNSETTLED WEATHER CONTINUES IN THE LONG TERM WITH A PRETTY GOOD WINTER SYSTEM POSSIBLE SUNDAY INTO MONDAY. STARTING OFF ON FRIDAY...FAST MOVING SHORTWAVE MOVES THROUGH NORTHERN PORTIONS OF WYOMING WITH SHOWERS CONTINUING OVER OUR WESTERN MOUNTAINS. TEMPERATURES LOOK WARM ENOUGH FOR MAINLY RAIN SHOWERS. WILL NEED TO WATCH THIS FRIDAY AS THE RAIN COULD EXACERBATE SNOW MELT OVER THE SNOWY AND SIERRA MADRE RANGES. BY SATURDAY AFTERNOON...A PRETTY STRONG PACIFIC LOW PRESSURE SYSTEM LOOKS TO MOVE INTO SOUTHERN IDAHO. A FRONTAL BOUNDARY BEGINS TO SAG SOUTH INTO CENTRAL WYOMING LATE SATURDAY NIGHT AND ENDS UP DOWN NEAR THE COLORADO/WYOMING BORDER BY SUNDAY MORNING. PRETTY COLD 700MB TEMPERATURES BEHIND THE FRONT...GFS SHOWING -6 TO -8C 700MB TEMPERATURES ACROSS MOST OF SOUTHEAST WYOMING SUNDAY MORNING. UPPER SHORTWAVE SUNDAY MORNING TRACKS INTO NORTHERN UTAH AND ACROSS NORTHERN COLORADO DURING THE DAY SUNDAY. NEW ECMWF VERY SIMILAR TO THE GFS ON THE TRACK OF THIS SHORTWAVE...IT IS EVEN COLDER THAN THE GFS THOUGH WITH 700MB TEMPERATURES OF -8 TO -10C BY SUNDAY AFTERNOON. WENT MUCH COLDER THAN GUIDANCE ON TEMPERATURES SUNDAY AND BOOSTED POPS OVER GUIDANCE AS WELL. PROBABLY NOT COLD ENOUGH THOUGH AND LATER SHIFTS WILL NEED TO LOWER EVEN MORE. THIS SYSTEM FINALLY PUSHES SOUTHEAST SUNDAY NIGHT INTO MONDAY. LOOKS LIKE A PRETTY COLD MORNING MONDAY WITH LOWS IN THE 20S FOR MANY LOCATIONS. SHOULD START TO SEE A REBOUND IN TEMPERATURE THOUGH MONDAY AFTERNOON AS 700MB TEMPERATURES CLIMB TO ABOVE FREEZING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 627 AM MDT WED MAY 7 2014 WIDESPREAD LOW CLOUDS AND FOG THIS MORNING THROUGH AT LEAST 16-17Z TIME FRAME BEFORE CLOUDS BEGIN TO BREAK UP. LATEST HRRR FORECAST DOING VERY WELL ON THIS STRATUS AND FOG AND GENERALLY FOLLOWED ITS GUIDANCE. CONVECTION STILL LOOKS TO BE A GOOD POSSIBILITY THIS AFTERNOON AND EARLY EVENING. THEN TONIGHT...WITH COLDER TEMPERATURES...WE SHOULD SEE RAIN TURN OVER TO SNOW WITH IFR/LIFR RETURNING. && .FIRE WEATHER... ISSUED AT 408 AM MDT WED MAY 7 2014 NO FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK. VERY WET LATER TODAY THROUGH TONIGHT. RAIN AND SNOW FOR MUCH OF THE AREA. COULD SEE SNOW ACCUMULATIONS IN SOME PLACES. DRIER FOR FRIDAY AND SATURDAY WITH A FEW SHOWERS HERE OR THERE...THEN ANOTHER LARGE STORM SYSTEM POSSIBLE SATURDAY NIGHT AND SUNDAY WITH SNOW POSSIBLE ESPECIALLY OVER SOUTHEAST WYOMING. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH LATE TONIGHT FOR WYZ119. NE...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH LATE TONIGHT FOR NEZ020-021-054-055. && $$ UPDATE...SML SHORT TERM...SML LONG TERM...CLAYCOMB AVIATION...CLAYCOMB FIRE WEATHER...SML
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
230 PM MST WED MAY 7 2014 .UPDATE...UPDATED AVIATION DISCUSSION... && .SYNOPSIS... PACIFIC LOW PRESSURE WILL CONTINUE TO MOVE THROUGH THE REGION TODAY...BRINGING COOLER TEMPERATURES AND ANOTHER ROUND OF AFTERNOON BREEZES. WINDS ARE NOT EXPECTED AS STRONG AS THOSE OBSERVED TUESDAY...WITH ONLY ISOLATED GUSTS POSSIBLE IN THE AFTERNOON. FORECAST DAYTIME HIGHS WILL FALL WELL BELOW NORMAL AT MANY DESERT LOCATIONS THROUGH THURSDAY. DRY AND WARMER WEATHER IS ON TAP FRIDAY AND THROUGH THE WEEKEND AS HIGH TEMPERATURES CLIMB BACK INTO THE 90S ACROSS THE LOWER DESERTS. && .DISCUSSION... COLD FRONT FROM YESTERDAY IS NOW IN NEW MEXICO BUT A FAIRLY TIGHT SURFACE PRESSURE GRADIENT REMAINS ACROSS THE FORECAST AREA AND THUS SOME BREEZINESS CAN BE EXPECTED AS THE DAY PROGRESSES BUT MUCH LESS WIND THAN YESTERDAY. MEANWHILE THE UPPER REMAINS OVER THE INTERIOR WEST WITH 12Z PLOT DATA INDICATING THE NORTH-SOUTH ORIENTED AXIS OVER WESTERN UTAH AND WESTERN ARIZONA WITH THE CENTER OF THE UPPER CIRCULATION OVER WESTERN UTAH. SATELLITE IMAGERY SHOWS A FAIR AMOUNT OF MID CLOUDS OVER NORTHERN AND EASTERN ARIZONA. SATELLITE IMAGERY ALSO SHOWS A VORT LOBE ROUNDING THE BOTTOM OF THE TROUGH OVER SOUTHERN ARIZONA. UVV ASSOCIATED WITH THIS FEATURE WILL BE SHIFTING TO NEW MEXICO BY AFTERNOON. COLD AIR ALOFT WILL ALLOW FOR SOME MEAGER CAPE...MAINLY OVER NORTHERN ARIZONA...BUT BOTH 12Z NAM AND GFS HAVE MORE CIN THAN CAPE. A TRAILING SHORT WAVE TONIGHT WILL HAVE EVEN LESS LIFT THAN THE ONE FOR TODAY. SO...SLIGHT CHANCES OF PRECIP OVER SOME HIGHER TERRAIN PORTIONS OF THE FORECAST AREA WILL BE ABOUT THE MOST WE CAN MUSTER. OTHERWISE...JUST SOME MID CLOUDS. OTHERWISE...FORECAST TEMPS ON TRACK FOR A NICE COOL DAY TODAY. && .PREVIOUS DISCUSSION ISSUED 206 AM... SHARPLY DEFINED PACIFIC TROUGH CONTINUES TO SLOWLY CIRCULATE INTO THE REGION...WITH THE TROUGH AXIS NEARING THE COLORADO RIVER VALLEY THIS MORNING. NEARLY CLEAR SKIES LEFT OVER THE WHOLE CWA IN THE WAKE OF THE VIGOROUS COLD FRONT PASSAGE TUESDAY. SOME EARLY EVENING/OVERNIGHT LIGHT SHOWER ACTIVITY CONTINUES NEAR THE COLD CORE OF THE TROUGH OVER SOUTHERN NEVADA AND TO A LESSER EXTENT SOUTHEAST CALIFORNIA...WITH MOST SITES ONLY REPORTING OVERCAST SKIES AND A HUNDREDTH OR TWO OF PRECIP ACROSS THE SOUTHERN NEVADA STATIONS. WATER VAPOR LOOP AND POTENTIAL VORTICITY MODEL OVERLAY PLOT A POCKET OF ENHANCED VORTICITY/SPIN COMING AROUND THE TROUGH BOTTOM AND ACROSS THE CA/INTL BORDER THIS MORNING. THIS VORT LOBE IS PROGGED THROUGH CENTRAL ARIZONA BY MIDDAY BEFORE QUICKLY DIFFUSING AND CLEARING EAST THIS EVENING. MOISTURE TRANSPORT AND PWATS NOT OVERLY FAVORABLE FOR SIGNIFICANT SHOWER ACTIVITY...WITH THE BEST PWATS OF NEAR HALF AN INCH OVER THE COLORADO RIVER VALLEY BY MIDDAY AND NOT EXTENDING MUCH FURTHER EAST. EVENING RUNS OF THE HI-RES HRRR AND ARW SHOW ANY SHOWER ACTIVITY DEVELOPING ACROSS NORTHERN ARIZONA THROUGH THE DAY AS THE TROUGH CONTINUES THROUGH THE AREA...WITH ONLY VERY SPOTTY DEVELOPMENT SKIRTING ACROSS THE NORTHERN PORTIONS OF MARICOPA AND GILA COUNTIES THROUGH THE AFTERNOON. SLIGHT CHANCE POPS WERE KEPT ACROSS THE HIGHER TERRAIN TO THE NORTH/EAST OF PHOENIX...WITH MENTION DROPPING OFF AFTER 08/03Z (8PM LOCAL) ONCE HEATING SUPPORT IS LOST WITH SUNSET. SIGNIFICANT COOLING OBSERVED BEHIND THE COLD FRONT...AS MUCH AS 10 DEGREES FROM THE SFC UP THROUGH 400MB VIA THE KVEF 00Z RAOB AND 6-8 DEGREES FROM KFGZ...WILL KEEP TEMPERATURES TODAY AND THURSDAY WELL BELOW SEASONAL NORMALS. LOOK FOR MID TO UPPER 70S ACROSS THE SOUTH- CENTRAL ARIZONA DESERTS WITH SLIGHTLY WARMER VALUES ACROSS THE WESTERN FORECAST AREA IN THE LOW 80S WEDNESDAY AND WIDESPREAD 80S AREAWIDE FOR THURSDAY UNDER MOSTLY CLEAR SKIES. BY FRIDAY...TROUGHING WILL HAVE MOSTLY CLEARED THE AREA WITH DRY WEST TO NORTHWESTERLY FLOW OVERTAKING THE REGION. TEMPERATURES WILL REBOUND BACK TOWARDS EARLY MAY NORMALS WITH LOW TO MID 90 DEGREE READINGS IN STORE FOR THE WEEKEND. ANOTHER LOW PRESSURE SYSTEM WILL DROP OUT OF THE PACIFIC NORTHWEST LATE SATURDAY INTO SUNDAY...BUT CURRENT THINKING FROM WPC AND THE BETTER PERFORMING OPERATIONAL/ENSEMBLE RUNS OF THE ECMWF KEEP THE BULK OF THE ENERGY AND ANY PRECIPITATION WELL TO OUR NORTH THROUGH MUCH OF THE GREAT BASIN STATES AND ONLY SKIRTING THE FAR NORTHERN PORTIONS OF ARIZONA. COULD SEE SOME ENHANCED BREEZINESS AS SOME GRADIENT TIGHTENING IS FORECAST...BUT VERY STRONG WINDS ARE NOT EXPECTED AT THIS TIME. 500MB HEIGHTS AND THICKNESSES WILL SEE SOME DECREASE...WHICH WILL KEEP DAYTIME TEMPERATURES FROM TAKING OFF TOO RAPIDLY FOR EARLY NEXT WEEK AND STAYING CLOSER TOWARDS NORMAL READINGS IN THE LOW TO MID 90S. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... WINDS CONTINUE TO REMAIN BREEZY TO GUSTY INTO THE LATE AFTERNOON AND EVENING HOURS...GUSTS TO 25 KTS OR SO ARE POSSIBLE. PREDOMINANTLY FROM THE WEST-SOUTHWEST DIRECTION AND SHOULD SWING TO AN EASTERLY HEADING BY 12Z THURSDAY MORNING. EXPECT LOWER CLOUD DECKS...8-10KT FEET TO LINGER THROUGH THE EVENING HOURS. LINGERING DUST/HAZE SHOULD IMPROVE AS MIXING CONTINUES...BUT MAY HANG AROUND THROUGH THE EVENING. VISIBILITIES SHOULD NOT BE IMPACTED BY HAZE. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... ELEVATED WINDS ACROSS SOUTHEAST CALIFORNIA TAF SITES AS WEATHER SYSTEM DEPARTS TO THE EAST WILL TAPER OFF AFTER SUNSET. HOLDING WESTERLY DIRECTION...WINDS SHOULD REMAIN BREEZY WITH GUSTS BELOW 25 KTS. MOSTLY CLEAR SKIES WITH SOME CU DECKS 8-10 KT FT POSSIBLE ESPECIALLY NEAR KBLH. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH WEDNESDAY... DRY NORTHWEST FLOW ALOFT WILL SETTLE IN ACROSS THE AREA INTO THE WEEKEND...ALLOWING FOR A GRADUAL WARMING TREND WITH DESERT HIGHS CLIMBING INTO THE MID 90S BY SATURDAY. HUMIDITIES WILL BE ON THE LOW SIDE...RANGING FROM SINGLE DIGITS TO THE LOW TEENS EACH DAY. A WEATHER DISTURBANCE PASSING BY TO THE NORTH OVER THE WEEKEND WILL LEAD TO LOCALLY BREEZY CONDITIONS DURING THE AFTERNOON AND EVENING HOURS SATURDAY AND SUNDAY. EVEN HIGHER PRESSURE ALOFT WILL THEN BUILD BACK INTO THE DESERT SOUTHWEST EARLY NEXT WEEK FOR LIGHTER WIND...ALONG WITH WARMER AND DRIER CONDITIONS. BY NEXT TUESDAY EXPECT THE WARMER DESERTS TO EXCEED 100 DEGREES...AND MINIMUM HUMIDITIES TO FALL WELL BELOW 10 PERCENT OVER THE DRIER LOWER DESERT. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...AJ PREVIOUS DISCUSSION...NOLTE AVIATION...CDEWEY FIRE WEATHER...CB
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
955 AM MST WED MAY 7 2014 .SYNOPSIS... PACIFIC LOW PRESSURE WILL CONTINUE TO MOVE THROUGH THE REGION TODAY...BRINGING COOLER TEMPERATURES AND ANOTHER ROUND OF AFTERNOON BREEZES. WINDS ARE NOT EXPECTED AS STRONG AS THOSE OBSERVED TUESDAY...WITH ONLY ISOLATED GUSTS POSSIBLE IN THE AFTERNOON. FORECAST DAYTIME HIGHS WILL FALL WELL BELOW NORMAL AT MANY DESERT LOCATIONS THROUGH THURSDAY. DRY AND WARMER WEATHER IS ON TAP FRIDAY AND THROUGH THE WEEKEND AS HIGH TEMPERATURES CLIMB BACK INTO THE 90S ACROSS THE LOWER DESERTS. && .DISCUSSION... COLD FRONT FROM YESTERDAY IS NOW IN NEW MEXICO BUT A FAIRLY TIGHT SURFACE PRESSURE GRADIENT REMAINS ACROSS THE FORECAST AREA AND THUS SOME BREEZINESS CAN BE EXPECTED AS THE DAY PROGRESSES BUT MUCH LESS WIND THAN YESTERDAY. MEANWHILE THE UPPER REMAINS OVER THE INTERIOR WEST WITH 12Z PLOT DATA INDICATING THE NORTH-SOUTH ORIENTED AXIS OVER WESTERN UTAH AND WESTERN ARIZONA WITH THE CENTER OF THE UPPER CIRCULATION OVER WESTERN UTAH. SATELLITE IMAGERY SHOWS A FAIR AMOUNT OF MID CLOUDS OVER NORTHERN AND EASTERN ARIZONA. SATELLITE IMAGERY ALSO SHOWS A VORT LOBE ROUNDING THE BOTTOM OF THE TROUGH OVER SOUTHERN ARIZONA. UVV ASSOCIATED WITH THIS FEATURE WILL BE SHIFTING TO NEW MEXICO BY AFTERNOON. COLD AIR ALOFT WILL ALLOW FOR SOME MEAGER CAPE...MAINLY OVER NORTHERN ARIZONA...BUT BOTH 12Z NAM AND GFS HAVE MORE CIN THAN CAPE. A TRAILING SHORT WAVE TONIGHT WILL HAVE EVEN LESS LIFT THAN THE ONE FOR TODAY. SO...SLIGHT CHANCES OF PRECIP OVER SOME HIGHER TERRAIN PORTIONS OF THE FORECAST AREA WILL BE ABOUT THE MOST WE CAN MUSTER. OTHERWISE...JUST SOME MID CLOUDS. OTHERWISE...FORECAST TEMPS ON TRACK FOR A NICE COOL DAY TODAY. && .PREVIOUS DISCUSSION ISSUED 206 AM... SHARPLY DEFINED PACIFIC TROUGH CONTINUES TO SLOWLY CIRCULATE INTO THE REGION...WITH THE TROUGH AXIS NEARING THE COLORADO RIVER VALLEY THIS MORNING. NEARLY CLEAR SKIES LEFT OVER THE WHOLE CWA IN THE WAKE OF THE VIGOROUS COLD FRONT PASSAGE TUESDAY. SOME EARLY EVENING/OVERNIGHT LIGHT SHOWER ACTIVITY CONTINUES NEAR THE COLD CORE OF THE TROUGH OVER SOUTHERN NEVADA AND TO A LESSER EXTENT SOUTHEAST CALIFORNIA...WITH MOST SITES ONLY REPORTING OVERCAST SKIES AND A HUNDREDTH OR TWO OF PRECIP ACROSS THE SOUTHERN NEVADA STATIONS. WATER VAPOR LOOP AND POTENTIAL VORTICITY MODEL OVERLAY PLOT A POCKET OF ENHANCED VORTICITY/SPIN COMING AROUND THE TROUGH BOTTOM AND ACROSS THE CA/INTL BORDER THIS MORNING. THIS VORT LOBE IS PROGGED THROUGH CENTRAL ARIZONA BY MIDDAY BEFORE QUICKLY DIFFUSING AND CLEARING EAST THIS EVENING. MOISTURE TRANSPORT AND PWATS NOT OVERLY FAVORABLE FOR SIGNIFICANT SHOWER ACTIVITY...WITH THE BEST PWATS OF NEAR HALF AN INCH OVER THE COLORADO RIVER VALLEY BY MIDDAY AND NOT EXTENDING MUCH FURTHER EAST. EVENING RUNS OF THE HI-RES HRRR AND ARW SHOW ANY SHOWER ACTIVITY DEVELOPING ACROSS NORTHERN ARIZONA THROUGH THE DAY AS THE TROUGH CONTINUES THROUGH THE AREA...WITH ONLY VERY SPOTTY DEVELOPMENT SKIRTING ACROSS THE NORTHERN PORTIONS OF MARICOPA AND GILA COUNTIES THROUGH THE AFTERNOON. SLIGHT CHANCE POPS WERE KEPT ACROSS THE HIGHER TERRAIN TO THE NORTH/EAST OF PHOENIX...WITH MENTION DROPPING OFF AFTER 08/03Z (8PM LOCAL) ONCE HEATING SUPPORT IS LOST WITH SUNSET. SIGNIFICANT COOLING OBSERVED BEHIND THE COLD FRONT...AS MUCH AS 10 DEGREES FROM THE SFC UP THROUGH 400MB VIA THE KVEF 00Z RAOB AND 6-8 DEGREES FROM KFGZ...WILL KEEP TEMPERATURES TODAY AND THURSDAY WELL BELOW SEASONAL NORMALS. LOOK FOR MID TO UPPER 70S ACROSS THE SOUTH- CENTRAL ARIZONA DESERTS WITH SLIGHTLY WARMER VALUES ACROSS THE WESTERN FORECAST AREA IN THE LOW 80S WEDNESDAY AND WIDESPREAD 80S AREAWIDE FOR THURSDAY UNDER MOSTLY CLEAR SKIES. BY FRIDAY...TROUGHING WILL HAVE MOSTLY CLEARED THE AREA WITH DRY WEST TO NORTHWESTERLY FLOW OVERTAKING THE REGION. TEMPERATURES WILL REBOUND BACK TOWARDS EARLY MAY NORMALS WITH LOW TO MID 90 DEGREE READINGS IN STORE FOR THE WEEKEND. ANOTHER LOW PRESSURE SYSTEM WILL DROP OUT OF THE PACIFIC NORTHWEST LATE SATURDAY INTO SUNDAY...BUT CURRENT THINKING FROM WPC AND THE BETTER PERFORMING OPERATIONAL/ENSEMBLE RUNS OF THE ECMWF KEEP THE BULK OF THE ENERGY AND ANY PRECIPITATION WELL TO OUR NORTH THROUGH MUCH OF THE GREAT BASIN STATES AND ONLY SKIRTING THE FAR NORTHERN PORTIONS OF ARIZONA. COULD SEE SOME ENHANCED BREEZINESS AS SOME GRADIENT TIGHTENING IS FORECAST...BUT VERY STRONG WINDS ARE NOT EXPECTED AT THIS TIME. 500MB HEIGHTS AND THICKNESSES WILL SEE SOME DECREASE...WHICH WILL KEEP DAYTIME TEMPERATURES FROM TAKING OFF TOO RAPIDLY FOR EARLY NEXT WEEK AND STAYING CLOSER TOWARDS NORMAL READINGS IN THE LOW TO MID 90S. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... UPPER LOW WILL CONTINUE TO MOVE EAST ACROSS THE AREA TODAY INTO TONIGHT. EXPECT SCT-BKN CU/SC DECKS TO DEVELOP ACROSS THE CENTRAL DESERTS LATER THIS MORNING...CONTINUING INTO THE AFTERNOON HOURS WITH BASES GENLY 8-10K FEET. NO PRECIP EXPECTED AT THE TAF SITES...ONLY ACROSS HIGHER ELEVATIONS NORTH/EAST OF PHOENIX. WINDS TO STAY MOSTLY OUT OF THE WEST THIS MORNING...INCREASING AND BECOMING LOCALLY GUSTY BY LATE MORNING OR EARLY AFTN. MAY SEE A FEW GUSTS TO 25KT OR SO BY AFTN. WINDS TO TAPER OFF AFTER SUNSET...SKIES TO BECOME MOSTLY CLEAR. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... UPPER LOW WILL CONTINUE TO MOVE EAST ACROSS THE AREA TODAY...BRINGING LOCALLY GUSTY WEST WINDS TO THE TAF SITES ALONG WITH FEW-SCT CUMULUS DECKS. THERE MAY BE SOME CIGS AROUND 8-10K THIS MORNING...WITH CLOUDS THINNING BY AFTERNOON AS SUBSIDENCE MOVES INTO AREA BEHIND A COLD FRONT. EXPECT SOME WIND GUSTS TO AT LEAST 25KT AT TIMES AT KIPL THIS AFTERNOON...A BIT LESS WIND AT KBLH. WINDS TO TAPER OFF AFTER SUNSET FOLLOWING LACK OF MIXING...AND SKIES TO BECOME GENLY CLEAR. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... FRIDAY THROUGH TUESDAY... DRY NORTHWEST FLOW ALOFT WILL SETTLE IN ACROSS THE AREA FRIDAY INTO THE WEEKEND...ALLOWING FOR A GRADUAL WARMING TREND WITH DESERT HIGHS CLIMBING INTO THE MID 90S BY SATURDAY. HUMIDITIES WILL BE ON THE LOW SIDE...RANGING FROM SINGLE DIGITS TO THE LOW TEENS EACH DAY. A WEATHER DISTURBANCE PASSING BY TO THE NORTH OVER THE WEEKEND WILL LEAD TO LOCALLY BREEZY CONDITIONS DURING THE AFTERNOON AND EVENING HOURS SATURDAY AND SUNDAY. EVEN HIGHER PRESSURE ALOFT WILL THEN BUILD BACK INTO THE DESERT SOUTHWEST EARLY NEXT WEEK FOR LIGHTER WIND...ALONG WITH WARMER AND DRIER CONDITIONS. BY NEXT TUESDAY EXPECT THE WARMER DESERTS TO EXCEED 100 DEGREES...AND MINIMUM HUMIDITIES TO FALL WELL BELOW 10 PERCENT OVER THE DRIER LOWER DESERT. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...AJ PREVIOUS DISCUSSION...NOLTE AVIATION...CB FIRE WEATHER...CB
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
901 AM PDT WED MAY 7 2014 .SYNOPSIS...A WEAK COLD FRONT WILL BRING A SLIGHT CHANCE OF LIGHT RAIN OR DRIZZLE TO THE AREA THURSDAY AND THURSDAY NIGHT. OTHERWISE DRY AND MILD WEATHER IS FORECAST THROUGH THE REMAINDER OF THE WEEK AND INTO THE UPCOMING WEEKEND. && .DISCUSSSION...AS OF 8:50 AM PDT WEDNESDAY...STRATO-CU STILL REMAINS FIRMLY ENTRENCHED ALONG THE COAST FROM SAN MATEO TO PT SUR AND INLAND THROUGH PACHECO PASS. ELSEWHERE...MOSTLY SUNNY SKIES PREVAIL THIS MORNING. FOR THE REST OF TODAY...EXPECT THE PESKY STRATO-CU TO SLOWLY ERODE BACK TO THE COAST. LATEST HI-RES MODELS... LIKE THE HRRR...KEEP CLOUDS AROUND MRY BAY AND THE SAN MATEO COAST FOR THE REST OF THE DAY. THIS SEEMS PLAUSIBLE GIVEN THE LATEST SATELLITE IMAGERY AND CONTINUED ONSHORE FLOW. THE MORE NOTABLE WEATHER FEATURE WILL BE THE STRONG NORTHERLY WINDS TODAY. THE N-S GRADIENT IS FORECAST TO INCREASE AGAIN THIS AFTERNOON...WITH VERY WINDS CONDITIONS OVER THE COASTAL WATERS AND ALONG THE COAST. NO UPDATE IS PLANNED AT THIS TIME. CURRENT FORECAST IS ON TRACK. THE NEXT FORECAST CHALLENGE WILL BE LOW CONFIDENCE RAIN CHANCES ON THURSDAY. A WEAK TROUGH IS FORECAST TO MOVE THROUGH ON THURSDAY BRINGING A SLIGHT CHANCE OF RAIN TO THE REGION. MODEL GUIDANCE CONTINUES TO SHOW THAT THE BEST CHANCE FOR PRECIP REMAINS OVER THE NORTHERN HALF OF THE CWA...OR ABOUT NORTH OF MONTEREY BAY. IF RAIN DOES FALL...AMOUNTS WILL BE LIGHT AND A ONLY A FEW HUNDREDTHS. .PREVIOUS DISCUSSION...THE UPPER LOW ASSOCIATED WITH THE THURSDAY SYSTEM IS FORECAST TO MOVE INTO THE PACIFIC NORTHWEST BY LATE FRIDAY NIGHT AND THEN INTO THE NORTHERN GREAT BASIN BY SATURDAY NIGHT. THIS COULD TIGHTEN THE SURFACE PRESSURE GRADIENTS TO RESULT IN GUSTY NORTHERLY WINDS IN OUR HILLS ON SATURDAY NIGHT AND SUNDAY MORNING. WARMER WEATHER IS EXPECTED BY SUNDAY AND INTO NEXT WEEK AS DRY NORTHERLY FLOW DEVELOPS AND AN UPPER RIDGE BEGINS TO DEVELOP NEAR THE COAST. && .AVIATION...AS OF 4:20 AM PDT WEDNESDAY...MAINLY VFR CONDITIONS WILL PREVAIL AFTER 16Z. MODERATE CONFIDENCE. ANOTHER DAY OF STRONG WEST TO NORTHWEST WINDS ARE IN STORE FOR THE REGION THIS AFTERNOON INTO THE EARLY EVENING HOURS. OTHERWISE...A STORM SYSTEM IS FORECAST TO MOVE SOUTH TOWARD THE REGION EARLY THURSDAY MORNING...BRINGING POSSIBLE MVFR CIGS AT THE VERY END OF THE FORECAST PERIOD. VICINITY OF KSFO...PATCHY LOW CLOUDS SURROUND THE BAY...WITH SFO ON THE EDGE OF CLOUDS. SCT CLOUDS MAY IMPACT THE TERMINAL THROUGH THE 16Z HOUR...LOW CONFIDENCE. OTHERWISE...WEST WINDS WILL INCREASE SIGNIFICANTLY THIS AFTERNOON...WITH WIND GUSTS TO 35 KT PROBABLE. KSFO BRIDGE APPROACH...PATCHES OF SCT LOW CLOUDS MAY IMPACT THE APPROACH THROUGH THE 16Z HOUR PREVENTING VISUALS. MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH AT LEAST THE 18Z HOUR...LOW CONFIDENCE. NUMERICAL GUIDANCE IS ALL OVER THE PLACE WITH CLEARING TIMES...FROM 15Z TO AN ALL DAY EVENT. THE MODELS ARE IN BETTER AGREEMENT THAT KSNS WILL SEE CLEARING BETWEEN 18Z AND 19Z...WHEREAS KMRY IS A BIT MORE PESSIMISTIC. THE HRRR AND LAMP INDICATE AN ALL DAY EVENT...SO WENT WITH A LATER CLEARING TIME OF 19Z. AGAIN LOW CONFIDENCE. && .MARINE...AS OF 08:50 AM PDT WEDNESDAY...ROUGH SEAS WITH MODERATE TO OCCASIONALLY STRONG NORTHERLY WINDS WILL CONTINUE ACROSS THE WATERS THROUGH THIS EVENING. A WEAK COLD FRONT WILL PASS OVER THE WATERS LATE TONIGHT INTO THURSDAY. THIS FRONT WILL DISRUPT THE SURFACE PRESSURE GRADIENT WHICH WILL RESULT IN DECREASING WINDS AND IMPROVING SEA CONDITIONS. WINDS WILL INCREASE ONCE AGAIN FRIDAY EVENING AS THE SURFACE PRESSURE GRADIENT STRENGTHENS ALONG THE CALIFORNIA COAST. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT ARENA TO PT REYES 0-10 NM SCA...PT REYES TO PIGEON PT 0-10 NM SCA...PIGEON PT TO PT PINOS 0-10 NM SCA...PT ARENA TO PT REYES 10-60 NM SCA...PT REYES TO PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PINOS 10-60 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...ROUGH BAR ADVISORY FOR SF BAR UNTIL 3 PM SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM SCA...SF BAY SOUTH OF THE BAY BRIDGE FROM 1 PM SCA...MONTEREY BAY FROM 1 PM && $$ PUBLIC FORECAST: SIMS AVIATION: RILEY MARINE: LARRY VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
638 PM EDT WED MAY 7 2014 .SYNOPSIS... HIGH PRESSURE WILL SLOWLY MOVE OFFSHORE THROUGH TONIGHT. A WARM FRONT OVER THE OHIO VALLEY AND CAROLINAS WILL SLOWLY MOVE NORTHEAST AND PASS THROUGH THE FORECAST AREA EARLY SATURDAY. A WEAK COLD FRONT IS FORECAST TO CROSS THE AREA LATE SATURDAY OR EARLY SUNDAY AND THEN STALL JUST SOUTH OF THE AREA. ANOTHER WARM FRONT IS FORECAST TO CROSS THE AREA MONDAY OR TUESDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 445 PM ESTF UPDATED AT 630 PM: TEMPS TRIMMED SEVERAL DEGREES FURTHER THIS EVENING. NO THUNDER THRU 06Z AND PLAYED DOWN THUNDER IN THE WORDING TIL LATE. BEST POTENTIAL FOR ANY THUNDER AND HEAVY RAIN SHOWERS VERY LATE TONIGHT IS E CENTRAL AND SE PA AND S 1/2 NJ..ALONG AND S OF KABE-KBLM. THAT IS ALSO THE 18Z GFS SOLN AND I AM THINKING THAT HAS THE BEST CHANCE OF VERIFICATION WITH PROXIMITY TO THE UNSTABLE AIR. IN OTHER WORDS...REDEVELOPING CONVECTIVE CLUSTERS ARE USUALLY TOWARD THE GREATEST INSTABILITY. DIFFERENTIAL WAA IN A NW FLOW ALOFT SITUATION WITH SHORT WAVES ASSISTING PERIODS OF LIFT. USING SPC WRF...HRRR AND RAP TO ADJUST POPS AND A BEST MATCH TO THE GOING REALITY THIS EVENING. BASED ON OBSERVED TRENDS AT 830 PM WILL PROBABLY SHIFT HIGHEST POPS IN THE 06Z-15Z TIME FRAME FURTHER SOUTH AND THE WORDING AS POSSIBLY HEAVY SHOWERS AND ISOLATED TSTMS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... A CLOUDY/SHOWERY MORNING IS EXPECTED ACROSS THE AREA WITH A BIG RANGE IN TEMPERATURES ACROSS THE REGION DURING THE AFTN. HAVE ALREADY CUT POPS TO 12 PCT MOST OF THE AREA 16Z-22Z TIME FRAME...IN OTHER WORDS...I THINK ITS A RAINFREE AFTERNOON. HIGHS OVER MARYLANDS EASTERN SHORE MAY REACH THE MID/UPPER 70S WHILE FURTHER N OVER NRN NJ AND THE SRN POCONOS...THE HIGHS WILL ONLY RISE MAYBE NEAR 60. SCT TSTMS ARE POSSIBLE THU AS WELL...BUT CAPES ARE RATHER LOW...SO WE WILL JUST KEEP WORDING SCT FOR NOW. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... A WARM FRONT WILL BE WORKING ITS WAY NORTHWARD SLOWLY THU NIGHT INTO FRI. PRECIP CHANCES WILL OCCUR ALG THE FRONT AND END (OR DECREASE SUBSTANTIALLY) BEHIND IT. THE GFS SEEMS ANOMALOUSLY WET COMPARED TO THE OTHER GUID EARLY FRI AND WAS IGNORED. THE HIGHEST PRECIP CHCS ON THRU FRI WILL BE OVER NRN AREAS WHERE THE FRONT WILL TAKE THE LONGEST TIME TO CLEAR. FOR MANY AREAS, THE BULK OF FRI CUD BE DRY. FRI NIGHT LOOKS CLOUDY WITH CHC POPS AS THE AREA REMAINS IN THE WARM SECTOR, BUT A CDFNT IS APPROACHING FROM THE W. POPS WILL CONTINUE TO INCREASE ON SAT AS THE AFOREMENTIONED CDFNT GETS CLOSER AND CROSSES THE REGION LATER SAT. PRECIP SHUD DECREASE DURG SAT EVE AFTER FROPA. HIGH PRES THEN BUILDS BACK IN FOR SAT NIGHT INTO SUN. THEN THERE IS CONSIDERABLE MDL DISAGREEMENT FOR EARLY NEXT WEEK. THE GFS IS QUITE A BIT FASTER WITH THE NEXT LOW/CDFNT AND ASSOCD PRECIP THAN THE ECMWF. THE GFS HAS SOME DIURNAL PRECIP ON MON BUT A BETTER SHOT WITH THE CDFNT ON TUE. THE ECMWF IS ESSENTIALLY DRY THRU THE PD. THERE IS THE CHANCE OF SOME DIURNAL SHWRS MON BUT THEN NOTHING BEFORE THE CDFNT, WHICH IS AT LEAST A DAY BEHIND THE GFS. SO, IF THE ECMWF IS CORRECT, EARLY NEXT WEEK WOULD BE DRIER THAN THE GFS IS INDICATING, BUT THERE IS STILL A WEEK TO SORT THINGS OUT. BY EARLY NEXT WEEK, THE MDLS BUILD AN UPR RIDGE BACK OVER THE AREA. TEMPS WILL GENLY BE ABV NRML ON FRI BEHIND THE WMFNT AND NR OR PSBLY BELOW NRML AHEAD OF THE FRONT (ALSO DEPENDENT ON CLOUDS/PRECIP). THEN MOST OF THE REST OF THE UPCOMING WEEK WILL FEATURE ABOVE NRML TEMPS WITH HIGHS NR 80 THU THE WKND INTO ERLY NEXT WEEK. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TONIGHT...BKN-OVC CIGS AOA 5000 FT WITH A MVFR CIG POSSIBLY DEVELOPING AFTER 06Z. SCT SHOWERS...MOSTLY KABE SOUTH. THUNDER POTENTIAL IN MORE ORGANIZED HEAVY SHOWERS LIKELY AFTER 06Z WHERE IFR CONDS MAY DEVELOP IN SHOWERS/STRATUS...PROBABLY FOR MANY TAF SITES. LIGHT WIND. THURSDAY...MVFR CIGS MAY BREAK TO MAINLY VFR CIGS AOA 3000 FT THU AFTN. SHOWERS MAINLY IN THE MORNING MAYBE WITH ISOLATED TSTMS. LIGHT WIND TRENDING NE. OUTLOOK... THU NIGHT...MVFR CONDITIONS AT TIMES DUE TO SHWRS AND TSTMS EARLY (MAINLY N)...AS WELL AS LOWER CLOUDS AND FOG AS WARM FRONT MOVES NWD THRU THE REGION. MDT CONFIDENCE. FRI AND FRI NIGHT...PRIMARILY VFR DURING THE DAY AND SOME MVFR CONDS AT NIGHT. MDT-HIGH CONFIDENCE. SAT...OCCASIONAL MVFR TO BRIEFLY IFR CONDITIONS IN SCATTERED SHOWERS AND THUNDERSTORMS. MDT CONFIDENCE SUN-SUN NIGHT...VFR. HIGH CONFIDENCE. MON...MAINLY VFR. PSBL AFTN SHWRS/TSTMS THAT CUD LWR VSBYS/CIGS. LOW-MDT CONFIDENCE. && .MARINE... CONDITIONS ON THE WATERS WILL REMAIN BELOW SMALL CRAFT CRITERIA THROUGH THURSDAY. THERE MAY BE A FEW SCT TSTMS LATE TONIGHT AND THURSDAY. WINDS LIGHT TRENDING EASTERLY WITH TIME THRU THURSDAY. OUTLOOK... SUB SCA CONDS ARE EXPECTED THU NIGHT THRU FRI. FOG MAY BE THE GREATER CONCERN, ESPECIALLY THURSDAY NIGHT. WITH A VEERING OF WINDS TOWARD THE SOUTH, THE CONCERN MAY MOVE OUT OF OUR AREA BY FRIDAY NIGHT. SEAS INCREASE OVER THE WEEKEND, BUT WE ARE PLAYING IT A BIT MORE CONSERVATIVE DUE TO SWLY FLOW...BUT THERE IS SOME SCA POTENTIAL THERE. A GREATER SCA POTENTIAL OCCURS EARLY NEXT WEEK IN ADVANCE OF THE NEXT SYS, BUT THERE ARE STILL SOME TIMING ISSUES WRT TO THIS SYS. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...NIERENBERG NEAR TERM...DRAG/O`HARA 638 SHORT TERM...DRAG/O`HARA 638 LONG TERM...NIERENBERG AVIATION...DRAG/NIERENBERG/O`HARA 638 MARINE...DRAG/NIERENBERG/O`HARA 638
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
502 PM EDT WED MAY 7 2014 .SYNOPSIS... HIGH PRESSURE WILL SLOWLY MOVE OFFSHORE THROUGH TONIGHT. A WARM FRONT OVER THE OHIO VALLEY AND CAROLINAS WILL SLOWLY MOVE NORTHEAST AND PASS THROUGH THE FORECAST AREA AROUND FRIDAY. A WEAK COLD FRONT IS FORECAST TO CROSS THE AREA LATE SATURDAY OR EARLY SUNDAY AND THEN STALL JUST SOUTH OF THE AREA. ANOTHER WARM FRONT IS FORECAST TO CROSS THE AREA MONDAY OR TUESDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 630 PM ESTF SENT 445PM: TEMPS SIGNIFICANTLY COOLER THIS EVE. NO THUNDER THRU 06Z AND PLAYED DOWN THUNDER IN THE WORDING LATE. BEST POTENTIAL FOR ANY THUNDER AND HEAVY RAIN SHOWERS VERY LATE TONIGHT IS E CENTRAL AND SE PA AND S 1/2 NJ..ALONG AND S OF KABE-KBLM. DIFFERENTIAL WAA IN A NW FLOW ALOFT SITUATION WITH SHORT WAVES ASSISTING PERIODS OF LIFT. USING SPC WRF...HRRR AND RAP TO ADJUST POPS AND A BEST MATCH TO THE GOING REALITY. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... THE WARM FRONT WILL BE LIFTING ACROSS THE AREA THURSDAY. A CLOUDY/SHOWERY DAY IS EXPECTED ACROSS THE AREA WITH A BIG RANGE IN TEMPERATURES ACROSS THE REGION. HIGHS OVER THE DELMARVA MAY REACH THE MID/UPPER 70S WHILE FURTHER NE OVER NRN NJ AND THE SRN POCONOS...THE HIGHS WILL ONLY RISE INTO THE LOW 60S. SCT TSTMS ARE POSSIBLE THU AS WELL...BUT CAPES ARE RATHER LOW...SO WE WILL JUST KEEP WORDING SCT FOR NOW. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... A WARM FRONT WILL BE WORKING ITS WAY NORTHWARD SLOWLY THU NIGHT INTO FRI. PRECIP CHANCES WILL OCCUR ALG THE FRONT AND END (OR DECREASE SUBSTANTIALLY) BEHIND IT. THE GFS SEEMS ANOMALOUSLY WET COMPARED TO THE OTHER GUID EARLY FRI AND WAS IGNORED. THE HIGHEST PRECIP CHCS ON THRU FRI WILL BE OVER NRN AREAS WHERE THE FRONT WILL TAKE THE LONGEST TIME TO CLEAR. FOR MANY AREAS, THE BULK OF FRI CUD BE DRY. FRI NIGHT LOOKS CLOUDY WITH CHC POPS AS THE AREA REMAINS IN THE WARM SECTOR, BUT A CDFNT IS APPROACHING FROM THE W. POPS WILL CONTINUE TO INCREASE ON SAT AS THE AFOREMENTIONED CDFNT GETS CLOSER AND CROSSES THE REGION LATER SAT. PRECIP SHUD DECREASE DURG SAT EVE AFTER FROPA. HIGH PRES THEN BUILDS BACK IN FOR SAT NIGHT INTO SUN. THEN THERE IS CONSIDERABLE MDL DISAGREEMENT FOR EARLY NEXT WEEK. THE GFS IS QUITE A BIT FASTER WITH THE NEXT LOW/CDFNT AND ASSOCD PRECIP THAN THE ECMWF. THE GFS HAS SOME DIURNAL PRECIP ON MON BUT A BETTER SHOT WITH THE CDFNT ON TUE. THE ECMWF IS ESSENTIALLY DRY THRU THE PD. THERE IS THE CHANCE OF SOME DIURNAL SHWRS MON BUT THEN NOTHING BEFORE THE CDFNT, WHICH IS AT LEAST A DAY BEHIND THE GFS. SO, IF THE ECMWF IS CORRECT, EARLY NEXT WEEK WOULD BE DRIER THAN THE GFS IS INDICATING, BUT THERE IS STILL A WEEK TO SORT THINGS OUT. BY EARLY NEXT WEEK, THE MDLS BUILD AN UPR RIDGE BACK OVER THE AREA. TEMPS WILL GENLY BE ABV NRML ON FRI BEHIND THE WMFNT AND NR OR PSBLY BELOW NRML AHEAD OF THE FRONT (ALSO DEPENDENT ON CLOUDS/PRECIP). THEN MOST OF THE REST OF THE UPCOMING WEEK WILL FEATURE ABOVE NRML TEMPS WITH HIGHS NR 80 THU THE WKND INTO ERLY NEXT WEEK. && .AVIATION /21Z WEDNESDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TONIGHT...BKN-OVC CIGS AOA 5000 FT WITH A MVFR CIG POSSIBLY DEVELOPING AFTER 06Z. SCT SHOWERS...MOSTLY KABE SOUTH. THUNDER POTENTIAL IN MORE ORGANIZED HEAVY SHOWERS POSSIBLE AFTER 06Z WHERE IFR CONDS MAY DEVELOP IN SHOWERS/STRATUS. LIGHT WIND. THURSDAY...MVFR CIGS MAY BREAK TO MAINLY VFR CIGS AOA 3000 FT THU AFTN. SHOWERS MAINLY IN THE MORNING MAYBE WITH ISOLATED TSTMS. LIGHT WIND TRENDING NE. OUTLOOK... THU NIGHT...MVFR CONDITIONS AT TIMES DUE TO SHWRS AND TSTMS EARLY (MAINLY N)...AS WELL AS LOWER CLOUDS AND FOG AS WARM FRONT MOVES NWD THRU THE REGION. MDT CONFIDENCE. FRI AND FRI NIGHT...PRIMARILY VFR DURING THE DAY AND SOME MVFR CONDS AT NIGHT. MDT-HIGH CONFIDENCE. SAT...OCCASIONAL MVFR TO BRIEFLY IFR CONDITIONS IN SCATTERED SHOWERS AND THUNDERSTORMS. MDT CONFIDENCE SUN-SUN NIGHT...VFR. HIGH CONFIDENCE. MON...MAINLY VFR. PSBL AFTN SHWRS/TSTMS THAT CUD LWR VSBYS/CIGS. LOW-MDT CONFIDENCE. && .MARINE... CONDITIONS ON THE WATERS WILL REMAIN BELOW SMALL CRAFT CRITERIA THROUGH THURSDAY. THERE MAY BE A FEW SCT TSTMS LATE TONIGHT AND THURSDAY. WINDS LIGHT TRENDING EASTERLY WITH TIME THRU THURSDAY. OUTLOOK... SUB SCA CONDS ARE EXPECTED THU NIGHT THRU FRI. FOG MAY BE THE GREATER CONCERN, ESPECIALLY THURSDAY NIGHT. WITH A VEERING OF WINDS TOWARD THE SOUTH, THE CONCERN MAY MOVE OUT OF OUR AREA BY FRIDAY NIGHT. SEAS INCREASE OVER THE WEEKEND, BUT WE ARE PLAYING IT A BIT MORE CONSERVATIVE DUE TO SWLY FLOW...BUT THERE IS SOME SCA POTENTIAL THERE. A GREATER SCA POTENTIAL OCCURS EARLY NEXT WEEK IN ADVANCE OF THE NEXT SYS, BUT THERE ARE STILL SOME TIMING ISSUES WRT TO THIS SYS. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...NIERENBERG NEAR TERM...DRAG/O`HARA 502 SHORT TERM...O`HARA 502 LONG TERM...NIERENBERG AVIATION...DRAG/NIERENBERG/O`HARA 502 MARINE...DRAG/NIERENBERG/O`HARA 502
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
209 PM EDT WED MAY 7 2014 .SYNOPSIS... UPPER-LEVEL RIDGING AS WELL AS SURFACE HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH FRIDAY. THE RIDGE WILL WEAKEN SATURDAY AS A DISSIPATING FRONTAL SYSTEM MOVES INTO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... THE PRESSURE RIDGE EXTENDING INTO THE FORECAST AREA FROM THE ATLANTIC WILL MAINTAIN THE DRY CONDITIONS. SATELLITE TRENDS SUPPORT MOSTLY CLEAR SKIES. THE TEMPERATURE GUIDANCE WAS CONSISTENT. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE INTO THE FORECAST AREA FROM THE ATLANTIC THROUGH FRIDAY NIGHT. ALOFT...THE MODELS INDICATE THE RIDGE WILL SHIFT OFF THE COAST FRIDAY. THE GUIDANCE TEMPERATURES WERE CONSISTENT...BUT THE HIGH TEMPERATURE GUIDANCE MAY BE A LITTLE TOO COOL BASED ON RECENT VERIFICATION...DRY CONDITIONS...AND UPPER RIDGE. IT MAY BE SLIGHTLY COOLER FRIDAY AS SOME MID- AND HIGH-LEVEL CLOUDS MAY SPREAD INTO THE AREA IN THE SOUTHWESTERLY FLOW. && .LONG TERM /SATURDAY THROUGH TUESDAY/... THE MODELS SHOW SOME MOISTURE ASSOCIATED WITH THE REMNANTS OF A FRONT IN THE FORECAST AREA EARLY IN THE MEDIUM-RANGE PERIOD. A COLD FRONT MAY MOVE INTO THE AREA LATE IN THE PERIOD. THE GFS... ECMWF...AND EKD MOS HAVE BEEN TRENDING LOWER WITH THE POPS. THE LATEST GUIDANCE HAS POPS OF 20 TO 30 PERCENT. THE PATTERN SUPPORTS TEMPERATURES A LITTLE ABOVE NORMAL DURING THE PERIOD. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... MODERATE HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THE TAF PERIOD. HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL CONTINUE CONTROL THE WEATHER. THE AIR MASS WILL REMAIN RELATIVELY DRY WITH LITTLE IN THE WAY OF CLOUDS. WINDS WILL BE SOUTHWEST TO WEST 5 TO 10 KNOTS WITH OCCASIONAL GUST UP TO 18 KTS THROUGH THE AFTERNOON. LIGHT AND VARIABLE WILL RETURN THIS EVENING AS AN INVERSION DEVELOPS. THE NAM AND RUC MODELS INDICATED INCREASING LOW LEVEL MOISTURE FOR THE POSSIBILITY OF FOG OR STRATUS DEVELOPMENT AT AGS AND OGB 08/09Z THROUGH 08/12Z. THE SREF MODEL KEPT CIG/VSBY RESTRICTIONS SOUTHEAST OF THE TAF SITES. GIVEN A DRY AIR MASS AND THE DEVELOPMENT OF A LOW LEVEL JET FOR BOUNDARY LAYER MIXING AS WELL AS VERY LOW CONFIDENCE...WILL NOT INCLUDE FOG OVERNIGHT. .EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS TO AVIATION EXPECTED THURSDAY THROUGH SUNDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
548 PM EDT WED MAY 7 2014 .SYNOPSIS... ISSUED AT 547 PM EDT WED MAY 7 2014 A WARM FRONT WILL CONTINUE TO SHIFT NORTH THROUGH LOWER MICHIGAN TONIGHT. ANY SHOWERS AND THUNDERSTORMS ARE EXPECTED TO REMAIN WELL NORTH OF THE FRONT...WHICH SHOULD RESULT IN DRY CONDITIONS ACROSS OUR AREA TONIGHT. LOWS OVERNIGHT WILL RANGE FROM THE MID 50S OVER SOUTHEAST MICHIGAN AND NORTHWEST OHIO TO THE MID 60S OVER CENTRAL INDIANA. SUNNY TO PARTLY CLOUDY SKIES SHOULD ALLOW HIGH TEMPERATURES TO REACH WELL INTO THE MID 80S THROUGHOUT THE AREA THURSDAY. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 352 PM EDT WED MAY 7 2014 NEAR TERM FOCUS ON WIDELY SCT TSTMS ACROSS N ILLINOIS WITH WEAKER SHOWERS COMING ACROSS SOUTHERN LK MI. ILLINOIS ACTIVITY WAS BEING ENHANCED TO SOME DEGREE BY NE MOVING SHORT WAVE WHICH WILL PASS ACROSS THE AREA INTO THIS EVENING. STEEP MID LEVEL LAPSE RATES WERE IN PLACE ACROSS THE REGION...BUT STRONG ELEVATED MIXED LAYER WAS PREVENTING MORE WIDESPREAD DEVELOPMENT. ACTIVITY MOVING ACROSS THE LAKE WAS WEAKENING AS IT MOVES EAST. WARM FRONT HAS BEEN SURGING NORTH MUCH OF THE DAY WITH SW HALF OF THE AREA NOW IN THE UPR 70S TO LOW 80S. KIWX 88D APPEARS TO BE SHOWING THIS FEATURE WHICH LOOKS TO BE QUASI STATIONARY ALONG ROUTE 30. WOULD EXPECT THIS TO GET MOVING AGAIN ONCE THE SHORT WAVE PUSHES THROUGH. FOR NOW WILL HAVE A DRY FORECAST WITH EVE SHIFT TO MONITOR TRENDS FOR ADDITION OF ISOLATED CONVECTION UNTIL SUNSET. LOW LEVEL MSTR WILL CONTINUE TO PUSH INTO THE REGION TONIGHT WITH A BALMY EARLY MAY NIGHT IN STORE WITH LOWS A GOOD 10 TO 15 DEGREES ABOVE NORMAL RANGING FROM THE MID 50S TO LOW 60S. SEVERAL OF THE HIGH RES MODELS HAVE BEEN TRYING TO DEVELOP A STRATUS DECK ACROSS MUCH OF THE AREA AS COOLING TAKES PLACE. WHILE SETUP CAN`T BE FULLY DISMISSED...THINK MODELS ARE GETTING A BIT CARRIED AWAY WITH IT AT THIS POINT. IF ON THE OTHER HAND THE FRONTAL BOUNDARY REMAINS STALLED IN THE AREA...THEN A GREATER LIKELIHOOD OF LOW CLOUDS WOULD EXIST. STILL HOLDING WITH MOSTLY CLEAR/PARTLY CLOUDY SKIES TONIGHT. THURSDAY SHOULD BE WARM AND UNSTABLE AS TEMPS SOAR INTO THE LOW TO MID 80S. SFC BASED INSTABILITY WILL EXIST...BUT LACK OF TRIGGER AND STRONG EML STILL IN PLACE TO PRECLUDE ALL BUT SOME CU DEVELOPMENT. && .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 352 PM EDT WED MAY 7 2014 NORTHWARD LOW LEVEL MOISTURE TRANSPORT TO COMMENCE THURSDAY NIGHT VIA A 50 KNOT SOUTHERLY LOW LEVEL JET. SEVERAL WEAK MID/UPPER PERTURBATIONS WILL LIKELY TRACK INTO THE OHIO VALLEY/WESTERN GREAT LAKES REGION DURING THIS TIME. ELEVATED MIXED LAYER WILL LIKELY LIMIT ANY CONVECTION FOR MOST OF THE THURSDAY NIGHT PERIOD. CORFIDI VECTORS SHOULD TEND TO BECOME MORE SOUTHWESTERLY LATE THURSDAY NIGHT POSSIBLY FAVORING EASTWARD PROPAGATION OF IL CONVECTION INTO WESTERN PORTIONS OF THE AREA TOWARD FRIDAY MORNING. A FAIRLY STRONG WEST TO EAST ORIENTED MUCAPE GRADIENT SHOULD EXIST ACROSS THE REGION HOWEVER...SO SOME QUESTION AS TO WHAT PROPAGATION MODE THIS CONVECTION WILL TAKE. HAVE NOT MADE SIGNIFICANT CHANGES TO PREVIOUS POP FORECAST THURSDAY NIGHT...CONFINING OVERNIGHT LIKELY POPS TO THE FAR WEST. PRIMARY LOW LEVEL MOISTURE TONGUE WILL ADVECT INTO THE REGION EARLY FRIDAY...AIDED BY BROAD SYNOPTIC SCALE PRE-FRONTAL LOW LEVEL CONFLUENCE. THIS SHOULD SUPPORT EASTWARD EXPANSION OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS IN THE MORNING. CONFIDENCE IN FRIDAY AFTERNOON CONVECTIVE POTENTIAL STILL SOMEWHAT MUDDLED BY INFLUENCES OF MORNING PRECIP. MODELS ALSO STILL EXHIBITING SOME SIGNIFICANT DIFFERENCES IN TERMS OF TIMING NEXT PV ANOMALY TO LIFT INTO THE GREAT LAKES REGION SOME TIME LATE FRIDAY AFTERNOON/NIGHT. EXIT REGION OF 120 KNOT UPPER JET STREAK SHOULD ALSO ENHANCE SYNOPTIC SCALE LIFT BY FRIDAY EVENING...SUPPORTING ADDITIONAL CONVECTIVE DEVELOPMENT ALONG MAIN COLD FRONTAL BOUNDARY. ENHANCED DEEP LAYER SHEAR ASSOCIATED WITH THIS POCKET OF STRONGER UPPER FLOW...AND MORE LIKELY POSITION OF PRIMARY INSTABILITY AXIS ACROSS WESTERN PORTIONS OF FORECAST AREA LATE FRIDAY AFTERNOON/EARLY FRIDAY EVENING...MAY LEND TO A SMALL WINDOW OF SEVERE POTENTIAL DURING THIS PERIOD. AFOREMENTIONED PV ANOMALY TO BECOME MORE INFLUENCED BY UPPER LEVEL DEFORMATION FLOW AS IT LIFTS NORTHEASTWARD ACROSS THE GREAT LAKES/SOUTHERN ONTARIO WHICH SHOULD TEND TO SLOW EASTWARD FRONTAL PROGRESSION LATE FRIDAY NIGHT/EARLY SATURDAY. FRONTAL CONVERGENCE SHOULD TEND TO WEAKEN AS THIS OCCURS...SO WOULD EXPECT DIMINISHING COVERAGE DURING THE OVERNIGHT HOURS. HAVE MAINTAINED LOW CHANCE POPS ACROSS FAR SOUTHEAST SATURDAY DUE TO SLOWING NATURE OF BOUNDARY...BUT GREATER CONFIDENCE IN NEXT ROUND OF PRECIP SHOULD HOLD OFF UNTIL LATE SATURDAY NIGHT AS LOW LEVEL ISENTROPIC UPGLIDE COMMENCES OVER THIS BOUNDARY...PARTICULARLY ACROSS WESTERN PORTIONS OF THE AREA. DISTURBED SOUTHWESTERLY UPPER FLOW IN ADVANCE OF NEXT MORE SIGNIFICANT UPPER TROUGH ACROSS WESTERN CONUS WILL PROVIDE AT LEAST CHANCE OF SHOWERS/STORMS THROUGH MUCH OF THE LATE WEEKEND THROUGH EARLY NEXT PERIOD. HOWEVER...SOME SUBSTANTIAL MEDIUM RANGE MODEL DIFFERENCES PERSIST REGARDING PHASING THIS WESTERN CONUS TROUGH WITH SOUTH CENTRAL CANADIAN UPPER LOW. EC/GEM REMAIN MUCH SLOWER AND BETTER PHASED...WHILE GFS IS MUCH MORE PROGRESSIVE AND LESS PHASED...TAKING COLD FRONTAL BOUNDARY EAST OF THE AREA MONDAY NIGHT. AT THIS FORECAST DISTANCE WITH LARGE DETERMINISTIC/ENSEMBLE SPREADS...HAVE NOT STRAYED FAR FROM CONSENSUS APPROACH OF CRALLBLEND WHICH PROVIDES COMPROMISE IN TIMING OF THESE TWO CAMPS. OF HIGHER CONFIDENCE IS ANOTHER WARMING TREND LATE WEEKEND INTO MONDAY IN ADVANCE OF THIS SYSTEM...WITH HIGHS FROM MID 70S TO AROUND 80 POSSIBLE AGAIN BY SUNDAY. COOLER CONDITIONS EXPECTED ACROSS PORTIONS OF SOUTHWEST LOWER MICHIGAN WITH SWRLY LOW LEVEL COMPONENT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 144 PM EDT WED MAY 7 2014 WARM FRONT WAS CLEARING KFWA AND WILL ARRIVE AT KSBN SHORTLY ALLOWING FOR SOUTHERLY FLOW TO SET UP. MID/HIGH CLOUDS ABOUT ALL THAT IS AROUND FOR THE TIME BEING. WILL BE MONITORING CONVECTION DEVELOPING ACROSS CENTRAL ILLINOIS THAT COULD DRIFT INTO THE AREA LATER THIS AFTERNOON/EVE. SETUP NOT THE MOST FAVORABLE SO NO MENTION IN TAFS. OTHERWISE...INCREASE IN LL MSTR WILL TAKE PLACE TONIGHT WITH MANY OF THE HIGH RES MODELS SUGGESTING STRATUS DEVELOPING (SOME HINTS AT EVEN IFR CIGS). NOT READY TO BUY THIS YET WITH RUC STILL SHOWING GENERALLY CLEAR CONDITIONS SO WILL MAINTAIN PREV FORECAST. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...FISHER/KG SHORT TERM...FISHER LONG TERM...MARSILI AVIATION...FISHER VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
353 PM EDT WED MAY 7 2014 .SYNOPSIS... ISSUED AT 152 PM EDT WED MAY 7 2014 A WARM FRONT SHIFT QUICKLY NORTH INTO LOWER MICHIGAN BY TONIGHT. THUNDERSTORMS ARE EXPECTED TO REMAIN WELL NORTH OF THE FRONT... WHICH SHOULD RESULT IN DRY CONDITIONS ACROSS OUR AREA TODAY AND TONIGHT. TEMPERATURES WILL BE WARMER... WITH HIGHS TODAY IN THE 70S OVER SOUTHERN MICHIGAN AND NORTHERN PORTIONS OF NORTHWEST OHIO... AND IN THE LOWER TO MIDDLE 80S OVER THE REST OF THE AREA. LOWS TONIGHT WILL RANGE FROM THE MID 50S OVER SOUTHEAST MICHIGAN AND NORTHWEST OHIO TO THE MID 60S OVER CENTRAL INDIANA. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 352 PM EDT WED MAY 7 2014 NEAR TERM FOCUS ON WIDELY SCT TSTMS ACROSS N ILLINOIS WITH WEAKER SHOWERS COMING ACROSS SOUTHERN LK MI. ILLINOIS ACTIVITY WAS BEING ENHANCED TO SOME DEGREE BY NE MOVING SHORT WAVE WHICH WILL PASS ACROSS THE AREA INTO THIS EVENING. STEEP MID LEVEL LAPSE RATES WERE IN PLACE ACROSS THE REGION...BUT STRONG ELEVATED MIXED LAYER WAS PREVENTING MORE WIDESPREAD DEVELOPMENT. ACTIVITY MOVING ACROSS THE LAKE WAS WEAKENING AS IT MOVES EAST. WARM FRONT HAS BEEN SURGING NORTH MUCH OF THE DAY WITH SW HALF OF THE AREA NOW IN THE UPR 70S TO LOW 80S. KIWX 88D APPEARS TO BE SHOWING THIS FEATURE WHICH LOOKS TO BE QUASI STATIONARY ALONG ROUTE 30. WOULD EXPECT THIS TO GET MOVING AGAIN ONCE THE SHORT WAVE PUSHES THROUGH. FOR NOW WILL HAVE A DRY FORECAST WITH EVE SHIFT TO MONITOR TRENDS FOR ADDITION OF ISOLATED CONVECTION UNTIL SUNSET. LOW LEVEL MSTR WILL CONTINUE TO PUSH INTO THE REGION TONIGHT WITH A BALMY EARLY MAY NIGHT IN STORE WITH LOWS A GOOD 10 TO 15 DEGREES ABOVE NORMAL RANGING FROM THE MID 50S TO LOW 60S. SEVERAL OF THE HIGH RES MODELS HAVE BEEN TRYING TO DEVELOP A STRATUS DECK ACROSS MUCH OF THE AREA AS COOLING TAKES PLACE. WHILE SETUP CAN`T BE FULLY DISMISSED...THINK MODELS ARE GETTING A BIT CARRIED AWAY WITH IT AT THIS POINT. IF ON THE OTHER HAND THE FRONTAL BOUNDARY REMAINS STALLED IN THE AREA...THEN A GREATER LIKELIHOOD OF LOW CLOUDS WOULD EXIST. STILL HOLDING WITH MOSTLY CLEAR/PARTLY CLOUDY SKIES TONIGHT. THURSDAY SHOULD BE WARM AND UNSTABLE AS TEMPS SOAR INTO THE LOW TO MID 80S. SFC BASED INSTABILITY WILL EXIST...BUT LACK OF TRIGGER AND STRONG EML STILL IN PLACE TO PRECLUDE ALL BUT SOME CU DEVELOPMENT. && .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 352 PM EDT WED MAY 7 2014 NORTHWARD LOW LEVEL MOISTURE TRANSPORT TO COMMENCE THURSDAY NIGHT VIA A 50 KNOT SOUTHERLY LOW LEVEL JET. SEVERAL WEAK MID/UPPER PERTURBATIONS WILL LIKELY TRACK INTO THE OHIO VALLEY/WESTERN GREAT LAKES REGION DURING THIS TIME. ELEVATED MIXED LAYER WILL LIKELY LIMIT ANY CONVECTION FOR MOST OF THE THURSDAY NIGHT PERIOD. CORFIDI VECTORS SHOULD TEND TO BECOME MORE SOUTHWESTERLY LATE THURSDAY NIGHT POSSIBLY FAVORING EASTWARD PROPAGATION OF IL CONVECTION INTO WESTERN PORTIONS OF THE AREA TOWARD FRIDAY MORNING. A FAIRLY STRONG WEST TO EAST ORIENTED MUCAPE GRADIENT SHOULD EXIST ACROSS THE REGION HOWEVER...SO SOME QUESTION AS TO WHAT PROPAGATION MODE THIS CONVECTION WILL TAKE. HAVE NOT MADE SIGNIFICANT CHANGES TO PREVIOUS POP FORECAST THURSDAY NIGHT...CONFINING OVERNIGHT LIKELY POPS TO THE FAR WEST. PRIMARY LOW LEVEL MOISTURE TONGUE WILL ADVECT INTO THE REGION EARLY FRIDAY...AIDED BY BROAD SYNOPTIC SCALE PRE-FRONTAL LOW LEVEL CONFLUENCE. THIS SHOULD SUPPORT EASTWARD EXPANSION OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS IN THE MORNING. CONFIDENCE IN FRIDAY AFTERNOON CONVECTIVE POTENTIAL STILL SOMEWHAT MUDDLED BY INFLUENCES OF MORNING PRECIP. MODELS ALSO STILL EXHIBITING SOME SIGNIFICANT DIFFERENCES IN TERMS OF TIMING NEXT PV ANOMALY TO LIFT INTO THE GREAT LAKES REGION SOME TIME LATE FRIDAY AFTERNOON/NIGHT. EXIT REGION OF 120 KNOT UPPER JET STREAK SHOULD ALSO ENHANCE SYNOPTIC SCALE LIFT BY FRIDAY EVENING...SUPPORTING ADDITIONAL CONVECTIVE DEVELOPMENT ALONG MAIN COLD FRONTAL BOUNDARY. ENHANCED DEEP LAYER SHEAR ASSOCIATED WITH THIS POCKET OF STRONGER UPPER FLOW...AND MORE LIKELY POSITION OF PRIMARY INSTABILITY AXIS ACROSS WESTERN PORTIONS OF FORECAST AREA LATE FRIDAY AFTERNOON/EARLY FRIDAY EVENING...MAY LEND TO A SMALL WINDOW OF SEVERE POTENTIAL DURING THIS PERIOD. AFOREMENTIONED PV ANOMALY TO BECOME MORE INFLUENCED BY UPPER LEVEL DEFORMATION FLOW AS IT LIFTS NORTHEASTWARD ACROSS THE GREAT LAKES/SOUTHERN ONTARIO WHICH SHOULD TEND TO SLOW EASTWARD FRONTAL PROGRESSION LATE FRIDAY NIGHT/EARLY SATURDAY. FRONTAL CONVERGENCE SHOULD TEND TO WEAKEN AS THIS OCCURS...SO WOULD EXPECT DIMINISHING COVERAGE DURING THE OVERNIGHT HOURS. HAVE MAINTAINED LOW CHANCE POPS ACROSS FAR SOUTHEAST SATURDAY DUE TO SLOWING NATURE OF BOUNDARY...BUT GREATER CONFIDENCE IN NEXT ROUND OF PRECIP SHOULD HOLD OFF UNTIL LATE SATURDAY NIGHT AS LOW LEVEL ISENTROPIC UPGLIDE COMMENCES OVER THIS BOUNDARY...PARTICULARLY ACROSS WESTERN PORTIONS OF THE AREA. DISTURBED SOUTHWESTERLY UPPER FLOW IN ADVANCE OF NEXT MORE SIGNIFICANT UPPER TROUGH ACROSS WESTERN CONUS WILL PROVIDE AT LEAST CHANCE OF SHOWERS/STORMS THROUGH MUCH OF THE LATE WEEKEND THROUGH EARLY NEXT PERIOD. HOWEVER...SOME SUBSTANTIAL MEDIUM RANGE MODEL DIFFERENCES PERSIST REGARDING PHASING THIS WESTERN CONUS TROUGH WITH SOUTH CENTRAL CANADIAN UPPER LOW. EC/GEM REMAIN MUCH SLOWER AND BETTER PHASED...WHILE GFS IS MUCH MORE PROGRESSIVE AND LESS PHASED...TAKING COLD FRONTAL BOUNDARY EAST OF THE AREA MONDAY NIGHT. AT THIS FORECAST DISTANCE WITH LARGE DETERMINISTIC/ENSEMBLE SPREADS...HAVE NOT STRAYED FAR FROM CONSENSUS APPROACH OF CRALLBLEND WHICH PROVIDES COMPROMISE IN TIMING OF THESE TWO CAMPS. OF HIGHER CONFIDENCE IS ANOTHER WARMING TREND LATE WEEKEND INTO MONDAY IN ADVANCE OF THIS SYSTEM...WITH HIGHS FROM MID 70S TO AROUND 80 POSSIBLE AGAIN BY SUNDAY. COOLER CONDITIONS EXPECTED ACROSS PORTIONS OF SOUTHWEST LOWER MICHIGAN WITH SWRLY LOW LEVEL COMPONENT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 144 PM EDT WED MAY 7 2014 WARM FRONT WAS CLEARING KFWA AND WILL ARRIVE AT KSBN SHORTLY ALLOWING FOR SOUTHERLY FLOW TO SET UP. MID/HIGH CLOUDS ABOUT ALL THAT IS AROUND FOR THE TIME BEING. WILL BE MONITORING CONVECTION DEVELOPING ACROSS CENTRAL ILLINOIS THAT COULD DRIFT INTO THE AREA LATER THIS AFTERNOON/EVE. SETUP NOT THE MOST FAVORABLE SO NO MENTION IN TAFS. OTHERWISE...INCREASE IN LL MSTR WILL TAKE PLACE TONIGHT WITH MANY OF THE HIGH RES MODELS SUGGESTING STRATUS DEVELOPING (SOME HINTS AT EVEN IFR CIGS). NOT READY TO BUY THIS YET WITH RUC STILL SHOWING GENERALLY CLEAR CONDITIONS SO WILL MAINTAIN PREV FORECAST. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...FISHER SHORT TERM...FISHER LONG TERM...MARSILI AVIATION...FISHER VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
152 PM EDT WED MAY 7 2014 .SYNOPSIS... ISSUED AT 152 PM EDT WED MAY 7 2014 A WARM FRONT SHIFT QUICKLY NORTH INTO LOWER MICHIGAN BY TONIGHT. THUNDERSTORMS ARE EXPECTED TO REMAIN WELL NORTH OF THE FRONT... WHICH SHOULD RESULT IN DRY CONDITIONS ACROSS OUR AREA TODAY AND TONIGHT. TEMPERATURES WILL BE WARMER... WITH HIGHS TODAY IN THE 70S OVER SOUTHERN MICHIGAN AND NORTHERN PORTIONS OF NORTHWEST OHIO... AND IN THE LOWER TO MIDDLE 80S OVER THE REST OF THE AREA. LOWS TONIGHT WILL RANGE FROM THE MID 50S OVER SOUTHEAST MICHIGAN AND NORTHWEST OHIO TO THE MID 60S OVER CENTRAL INDIANA. && .UPDATE... ISSUED AT 144 PM EDT WED MAY 7 2014 FORECAST REMAINS ON TRACK FOR THE TIME BEING WITH WARM FRONT MAKING PROGRESS NORTH ACROSS THE AREA. OBSERVATIONS INDICATE A LOCATIONS SOMEWHERE ALONG OR JUST NORTH OF ROUTE 30 WITH A RAPID JUMP INTO THE 70S TO NEAR 80 SOUTH IT AND TEMPS WELL NE OF THE BOUNDARY STILL IN THE LOWER 60S. AS MENTIONED IN PREV UPDATE...EYES WOULD BE FOCUSED ON CENTRAL ILLINOIS BASED ON SOME OF THE HIGH RES MODELS INDICATING POSSIBLE WIDELY SCT CONVECTION AS MISSOURI SHORT WAVE MOVES NE. RADAR TRENDS OVER THE LAST HALF HOUR HAVE SHOWN NEW DEVELOPMENT FROM OVER THE KILX SITE NW...WITH THIS MOVING NNE. THIS ACTIVITY IS WELL SOUTH OF THE WARM FRONT...BUT MAY STILL BE SOMEWHAT ELEVATED GIVEN EML IN PLACE. REGARDLESS...ADDITIONAL MONITORING WILL BE NEEDED ACROSS THIS AREA FOR POSSIBLE WIDELY SCT CONVECTION LATER THIS AFTERNOON. WILL MAINTAIN DRY FORECAST FOR NOW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 458 AM EDT WED MAY 7 2014 HIGH PRESSURE OVER SE CANADA WILL CONTINUE TO MOVE SLOWLY EAST TODAY ALLOWING WARM FRONT OVER KY AND SRN IN/IL TO LIFT NORTH TO THE MI/IN-OH BORDER. BAND OF SHOWERS/TSTMS WHICH DEVELOPED IN THE STRONG THETA-E ADVECTION REGIME NORTH OF THIS WARM FRONT FROM WI SEWD INTO NW OH EARLY THIS MORNING WAS MOVG SLOWLY EAST WITH SOME BACKBUILDING. THUS, THE THREAT OF CONVECTION CONTS ACROSS THE NE PORTION OF THE CWA EARLY THIS MORNING... BUT EXPECT IT WILL END BY 12Z SO HAVE A PRE-FIRST PERIOD IN THE ZFP TO HANDLE ONGOING ACTIVITY. REST OF THE DAY SHOULD BE RAIN-FREE ACROSS OUR AREA AS WARM AND RELATIVELY DRY AIRMASS EVIDENT ON ILX`S 00Z SOUNDING OVERSPREADS OUR CWA. IR SATELLITE IMAGERY SUGGESTS CONSIDERABLE HIGH CLOUDINESS OVER OUR AREA AND UPSTREAM ACROSS IL/MO AND INTO THE SRN PLAINS. EXPECT PARTLY SUNNY SKIES ACROSS OUR AREA TODAY WITH MAINLY HIGH CLOUDINESS. TEMPS SHOULD RESPOND TO THE WARM FRONT MOVING NORTH WITH HIGHS IN THE L-M80S OVER THE AREA EXCEPT ONLY IN THE 70S OVER SRN MI AND NRN PORTIONS OF NW OH WHICH SHOULD REMAIN NORTH OF THE FRONT. WARM FRONT SHOULD CONT TO LIFT SLOWLY NORTH ACROSS LWR MI TONIGHT AS A STRONG SHRTWV LIFTS NE AHEAD OF ROCKIES TROF CAUSING STNRY SFC LOW OVER THE CENTRAL PLAINS TO LIFT NE TO ERN SD. CONVECTION SHOULD AGAIN BE WELL NORTH OF THE FRONT AS AIRMASS TO THE SOUTH REMAINS RELATIVELY DRY. THUS, CONTD DRY FCST FOR TONIGHT IN OUR AREA WITH MILD LOWS RANGING FROM THE M50S NE TO THE M60S SW. && .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 458 AM EDT WED MAY 7 2014 VERY WARM TEMPERATURES ON TRACK FOR THURSDAY WITH 850 MB TEMPS APPROACHING 20C PER LATEST 12KM/NAM. RAISED HIGHS A LITTLE TO COME IN LINE WITH THE GFS/MAV WHICH APPEARS ON TRACK WITH HIGHS APPROACHING RECORDS IN THE UPPER 80S AT FT WAYNE. THE FRONT WILL MOVE ACROSS THE AREA FRIDAY/FRIDAY NIGHT. THE GFS AND ECMWF HAVE COME INTO VERY GOOD AGREEMENT WITH THE TIMING OF THE FRONT...SO HAVE ADJUSTED RAIN/STORM CHANCES ACCORDINGLY. THE BEST CHANCE FOR SEVERE STORMS APPEARS TO BE OVER NORTHERN INDIANA LATE FRIDAY AFTERNOON INTO EARLY FRIDAY NIGHT AHEAD OF THE FRONT WHERE LOW LEVEL CONVERGENCE ALONG THE FRONT COMBINED WITH THE RIGHT ENTRANCE REGION OF THE JET MAY ALLOW SOME STORMS TO BECOME SEVERE. OTHERWISE... TEMPERATURES WILL BE COOLING BACK TO NORMAL FOR THE REST OF THE PERIOD. THE GFS AND ECMWF RUN TO RUN CONSISTENCY CONTINUES TO BE POOR LATE IN THE EXTENDED PERIOD...SO TRIED TO KEEP THE ONGOING FORECAST WITHOUT MAKING MANY CHANGES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 144 PM EDT WED MAY 7 2014 WARM FRONT WAS CLEARING KFWA AND WILL ARRIVE AT KSBN SHORTLY ALLOWING FOR SOUTHERLY FLOW TO SET UP. MID/HIGH CLOUDS ABOUT ALL THAT IS AROUND FOR THE TIME BEING. WILL BE MONITORING CONVECTION DEVELOPING ACROSS CENTRAL ILLINOIS THAT COULD DRIFT INTO THE AREA LATER THIS AFTERNOON/EVE. SETUP NOT THE MOST FAVORABLE SO NO MENTION IN TAFS. OTHERWISE...INCREASE IN LL MSTR WILL TAKE PLACE TONIGHT WITH MANY OF THE HIGH RES MODELS SUGGESTING STRATUS DEVELOPING (SOME HINTS AT EVEN IFR CIGS). NOT READY TO BUY THIS YET WITH RUC STILL SHOWING GENERALLY CLEAR CONDITIONS SO WILL MAINTAIN PREV FORECAST. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ UPDATE...FISHER SYNOPSIS...JT SHORT TERM...JT LONG TERM...SKIPPER AVIATION...FISHER VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS TOPEKA KS
515 PM CDT Wed May 7 2014 ...AVIATION UPDATE... .SHORT TERM...(This Evening through Thursday) Issued at 304 PM CDT WED MAY 7 2014 Tonight through Thursday ... Water vapor imagery showed the deep mid-level trough stretched across the western U.S. with southwesterly flow aloft over the Central Plains. At the surface, low pressure stretched across southwest to north central Kansas with the dryline nearly bisecting the state from north to south at 20z. With a tight pressure gradient in place across much of the region, south-southwesterly winds were gusting upwards of 25-35mph this afternoon, which aided in decent WAA as well as moisture advection across eastern Kansas with dewpoints reaching into the lower to middle 60s. It was another mild day across the region as high temperatures rose into the upper 80s/low 90s across eastern Kansas and into the mid/upper 90s over north central Kansas. The warmest conditions across north central Kansas were co-located with the drier conditions as dewpoints plunged as low as into the middle 30s, resulting in RH values dropping into the teens. These dry conditions combined with the breezy winds will keep very high fire danger concerns in place through early this evening, so a Red Flag Warning remains in effect through 8pm across portions of north central Kansas. Visible satellite this afternoon showed a few storms popping up across northern Texas/southern Oklahoma along the dryline. The last few runs of the HRRR/RAP have shown good run-to-run consistency as well as good agreement with each other regarding the current mid-afternoon development and additional northward development of showers and thunderstorms along this dryline this evening. This initial thunderstorm development looks to be supported by a mid-level shortwave, and as this wave tracks northward into the area this evening it will help to provide enhanced lift over the region. Model soundings show the cap eroding away this afternoon across the central portions of the forecast area (roughly from Council Grove northward toward Manhattan), with short-range models showing this region being well-primed for scattered thunderstorm development, beginning between 22z-00z. MLCAPE values in this region could be upwards of 2000-3000 J/kg with upwards of 20-30kts of 0-6km bulk shear. As a result, the stronger storms may be capable of producing large hail and possibly some stronger wind gusts later this evening as the LLJ increases over the region. This activity should diminish overnight with the loss of diurnal heating. Southerly winds will remain breezy overnight due to the aforementioned increasing LLJ, so this strong southerly flow combined with increasing mid-level cloud cover will keep low temperatures tonight mild in the middle 60s west to upper 60s/near 70 east. There is the potential for strong to severe thunderstorms once again on Thursday as the mid-level trough ejects into the Central Plains, finally pushing the cold front associated with this system eastward across the area by Thursday night. 12z model runs have come into better agreement with the timing of this frontal passage and the eastward progression of the dryline through the day. Latest model trends show any morning precipitation to be focused across far eastern Kansas, but there are discrepancies with the coverage of this activity. Feel that this activity should be fairly limited, which would lead to more time for the environment to recover to support redevelopment of thunderstorms along the dryline during the afternoon hours. While there are still some minor discrepancies with the exact placement of the dryline by the afternoon, thunderstorm initiation looks to occur somewhere between Abilene and Manhattan and between 18z-21z. The cap looks to quickly weaken during the early/mid afternoon hours with upwards of 1500-2000 J/kg of MUCAPE and 45-55kts of 0-6km bulk shear. While there certainly looks to be decent shear in place, it looks to be fairly unidirectional. The main threats with the strongest storms will be large hail and damaging winds, but cannot rule out the potential for a few isolated tornadoes. The increasing mid-level cloud cover will limit the daytime heating with Thursday highs likely reaching into the middle 70s to low 80s. .LONG TERM...(Thursday Night through Wednesday) Issued at 304 PM CDT WED MAY 7 2014 Extended focus will be on impacts of first system Thursday night and second system over the weekend. Thurs Night...ongoing convection should become focused across east central Kansas as convergence is maximized along the north side of a secondary surface low and boundary so will keep high precip chcs across that area. Much cooler and drier air will arrive for Friday with highs back toward average in the lower 70s with dewpoints in the 40s. The next longwave trough will begin to take shape across the Rockies by Saturday with sfc low pressure forecast to develop across southeast Colorado. Moisture advection along and north of the developing warm front could result in SCT convection so will leave low pops on Sat. Better chances for showers and t-storms will arrive Saturday night into Sunday as the sfc low sags into western OK and the associated sfc front also sags south. It would appear that given moisture and shear that Sunday could bring a risk for severe storms but that is dependent on details of front position so confidence in severe risk Sunday is low at the moment. Overall confidence in weather trends is higher by Monday so look for a wet and colder start to the next work week with precip chcs decreasing Monday night and ending by Tuesday. Temps next week should remain near Average of 70 to 75. && .AVIATION...(For the 00Z TAFs through 00Z Thursday Evening) Issued at 515 PM CDT WED MAY 7 2014 Amended the TAFs to remove the TEMPO for TS at TOP and FOE. Latest RAP and NAM show the axis of instability remaining fairly close to the dryline with larger amounts of CIN to the east. Therefore confidence in TS moving into the terminals is to low to keep a tempo. MHK conversely is just east of the dryline with some convection bubbling up to the southwest. Therefore will keep the tempo, but have shortened the duration of the tempo based on the latest HRRR prog of convection. Also backed off on the MVFR CIGS for Thursday morning. Don`t see a huge increase in low level moisture so am not sure why the NAM is saturating the boundary layer. The RAP fails to saturate the boundary layer so am skeptical of a CIG and will just mention a SCT deck possible at TOP and FOE Thursday morning. && .TOP WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING until 8 PM CDT this evening FOR KSZ008-009-020- 021-034-035. && $$ SHORT TERM...Hennecke LONG TERM...Omitt AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
147 PM MDT WED MAY 7 2014 .UPDATE... ISSUED AT 1048 AM MDT WED MAY 7 2014 ISSUED A WIND ADVISORY FOR THE SOUTHERNMOST SIX COUNTIES FOR LATER THIS AFTERNOON THROUGH EARLY EVENING. DEEP MIXING SHOULD ALLOW FOR GUSTS TO REACH 45 MPH IN THIS AREA. STILL SOME UNCERTAINTY HOW FAR NORTH STRONGER WINDS WILL DEVELOP BUT THE GREATEST THREAT OF ADVISORY CRITERIA WINDS SHOULD STAY SOUTH OF INTERSTATE 70. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 225 AM MDT WED MAY 7 2014 EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW DEEPENING TROUGH CURRENTLY CENTERED OVER THE GREAT BASIN WITH SW FLOW EXTENDING ACROSS CENTRAL ROCKIES AND PLAINS. AT THE SURFACE LOW PRESSURE CURRENTLY EXTENDS FROM EAST CENTRAL COLORADO ACROSS THE TRI STATE REGION WITH A STATIONARY FRONT BISECTING THIS FEATURE GENERALLY ALONG AND SOUTH OF INTERSTATE 70. A DRY LINE EXTENDING ACROSS CENTRAL KS HAS BEEN BACKING UP TOWARDS THE EASTERN PART OF OUR CWA. PARTICULARLY LOW CONFIDENCE IN FORECAST FOR TODAY AS A RESULT OF THE LINGERING STATIONARY FRONT AND INCONSISTENCIES BETWEEN GUIDANCE ON EVOLUTION OF SURFACE LOW AND FRONT TIMING AS UPPER TROUGH SHIFTS EAST INTO THE PLAINS. THIS IS A REFLECTION OF MODEL DIFFERENCES ON EVOLUTION/TRACK OF CLOSED H5/H7 LOW CENTERS ACROSS THE PLAINS TODAY/TONIGHT. WE COULD SEE WIDE RANGING IMPACTS DEPENDING ON ALL OF THE ABOVE MENTIONED VARIANCES ON BOTH OUR RFW...A POSSIBLE WIND ADVISORY...AND POTENTIAL SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE NORTHERN HALF OF OUR CWA. THERE IS SO MUCH SPREAD BETWEEN MODELS FROM THE I-70 CORRIDOR NORTH ALL I WAS UNCOMFORTABLE DOING MORE THAN NUDGING TOWARDS THE LATEST BLENDS/NAM TRENDS. THIS PUTS THE SE HALF OF OUR CWA NEAR WIND ADVISORY CRITERIA...AND ANOTHER ROW OF COUNTIES WITHIN RFW CRITERIA. REGARDING THE CURRENT RFW AND POSSIBLE WIND ADVISORY...CONFIDENCE IS JUST TOO LOW TO MAKE HIGHLIGHT CHANGES. BASED ON EVOLUTION OF SURFACE FEATURES WE COULD SEE THUNDERSTORM INITIATION AND SEVERE POTENTIAL BY MIDDAY FURTHER SOUTH (I-70 CORRIDOR) BEFORE ANY PRIMARY THUNDERSTORM CHANCES TRANSITION NORTH AND WEST. WE WILL NEED TO MONITOR AND ADJUST AS CONFIDENCE INCREASE BASED ON REAL TIME DATA AND NEW RUNS OF SHORT RANGE GUIDANCE TO GET A BETTER HANDLE ON SENSIBLE WEATHER OVER OUR CWA THROUGH THIS EVENING. AS UPPER LOW TRANSITIONS EAST A COLD FRONT EVENTUALLY WILL PUSH SOUTH TONIGHT BEFORE STALLING ACROSS THE SOUTHERN PART OF OUR CWA. BESIDES COMPLICATING THE TEMP FORECAST...THIS FEATURE COULD ACT AS A FOCUS FOR ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT AS A SECONDARY SHORTWAVE TROUGH MOVES ACROSS THE NORTHERN PLAINS BEHIND THE INITIAL UPPER LOW. I USED A CONSENSUS BLEND OF TEMPS THROUGH FRI AND LINGERED POPS THROUGH FRI NIGHT TO ACCOUNT FOR LIFT/MOISTURE ALONG FRONT AND ASSOCIATE WITH WEAK TROUGH PASSAGE. WHILE TEMPS SHOULD RETURN TO NEAR SEASONAL VALUES...IT DOES LOOK LIKE WE HAVE POTENTIAL FOR LOW TEMPS TO DROP WELL BELOW NORMAL IN THE 30S...AND ACTUALLY WITHIN FROST ADVISORY CRITERIA. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 135 PM MDT WED MAY 7 2014 TROUGH AXIS WILL BE MOVING EAST AND OUT OF THE AREA THURSDAY NIGHT WITH PRECIPITATION CHANCES DIMINISHING. CLEARING SKIES AND LIGHT WEST TO NORTHWEST WINDS WILL ALLOW TEMPERATURES TO DROP INTO THE UPPER 30S TO LOWER 40S...JUST ABOVE FROST ADVISORY CRITERIA. WEAK SHORTWAVE TROUGH EMBEDDED IN THE ZONAL FLOW ON FRIDAY AFTERNOON AND EVENING WILL BRING LOW CHANCES FOR RAIN SHOWERS IN NORTHEAST COLORADO AND THE NEBRASKA BORDER AREA...BUT WITH MUCAPE FORECAST TO BE ZERO DID NOT INCLUDE ANY MENTION OF THUNDER. TEMPERATURES WILL BE NEAR NORMAL...WITH LOWS FRIDAY NIGHT WELL ABOVE FROST CRITERIA. ZONAL FLOW ALOFT CONTINUES THROUGH THE REMAINDER OF THE EXTENDED PERIOD...WITH OCCASIONAL CHANCES FOR PRECIPITATION. BEST CHANCES APPEAR TO BE BETWEEN SATURDAY NIGHT AND MONDAY WITH A BETTER DEFINED SHORTWAVE TROUGH IN THE FLOW. THERE ARE SOME CONSIDERABLE TIMING DIFFERENCES AMONG THE MODELS SO DID NOT GET TOO SPECIFIC. THE COMBINATION OF CLOUDS AND COLD ADVECTION AT THE SURFACE WILL RESULT IN BELOW NORMAL TEMPERATURES. MUCAPE IS NEAR ZERO OR VERY LOW SO DO NOT HAVE ANY MENTION OF THUNDER UNTIL VERY LATE IN THE PERIOD WHEN MODELS HINT AT SOME WEAK INSTABILITY. WET BULB ZERO HEIGHTS SUGGEST A RAIN/SNOW MIX POSSIBLE SUNDAY AND MONDAY IN THE HIGHER TERRAIN OF THE WESTERN FORECAST AREA...BUT NO ACCUMULATION IS EXPECTED. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1142 AM MDT WED MAY 7 2014 VFR CONDITIONS ARE EXPECTED AT BOTH TERMINALS THROUGH THE PERIOD. THE WIND FORECAST IS QUITE CHALLENGING AND MAY REQUIRE AMENDMENTS THIS AFTERNOON. NORTHEASTERLY WINDS BEHIND A WEAK NEARLY STATIONARY FRONT HAVE PERSISTED THROUGH THE MORNING BUT SHOULD GRADUALLY TRANSITION TO SOUTHERLY AT GLD AS THE FRONT MOVES NORTHWARD. WINDS COULD BECOME GUSTY THIS AFTERNOON...ESPECIALLY AFTER 21Z LASTING INTO THE EARLY EVENING. AT KMCK WINDS ARE EXPECTED TO REMAIN EASTERLY/NORTHEASTERLY THROUGH THE FIRST PART OF THE NIGHT. AT BOTH TERMINALS A COLD FRONT WILL MOVE THROUGH LATE RESULTING IN A SHIFT TO NORTHWESTERLY WINDS...WITH GUSTS 30-35 KNOTS POSSIBLE...ESPECIALLY BY MID MORNING. THUNDERSTORMS WILL LIKELY FORM NORTH OF THE BOUNDARY LATE THIS AFTERNOON AND EVENING. THE GREATEST CHANCES WILL BE NORTHWEST OF BOTH TERMINALS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ013>016-027>029-041-042. WIND ADVISORY UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ027>029-041-042. CO...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ253-254. WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR COZ092. NE...NONE. && $$ UPDATE...BRB SHORT TERM...DR LONG TERM...024 AVIATION...BRB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1142 AM MDT WED MAY 7 2014 .UPDATE... ISSUED AT 1048 AM MDT WED MAY 7 2014 ISSUED A WIND ADVISORY FOR THE SOUTHERNMOST SIX COUNTIES FOR LATER THIS AFTERNOON THROUGH EARLY EVENING. DEEP MIXING SHOULD ALLOW FOR GUSTS TO REACH 45 MPH IN THIS AREA. STILL SOME UNCERTAINTY HOW FAR NORTH STRONGER WINDS WILL DEVELOP BUT THE GREATEST THREAT OF ADVISORY CRITERIA WINDS SHOULD STAY SOUTH OF INTERSTATE 70. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 225 AM MDT WED MAY 7 2014 EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW DEEPENING TROUGH CURRENTLY CENTERED OVER THE GREAT BASIN WITH SW FLOW EXTENDING ACROSS CENTRAL ROCKIES AND PLAINS. AT THE SURFACE LOW PRESSURE CURRENTLY EXTENDS FROM EASTCENTRAL COLORADO ACROSS THE TRI STATE REGION WITH A STATIONARY FRONT BISECTING THIS FEATURE GENERALLY ALONG AND SOUTH OF INTERSTATE 70. A DRY LINE EXTENDING ACROSS CENTRAL KS HAS BEEN BACKING UP TOWARDS THE EASTERN PART OF OUR CWA. PARTICULARLY LOW CONFIDENCE IN FORECAST FOR TODAY AS A RESULT OF THE LINGERING STATIONARY FRONT AND INCONSISTENCIES BETWEEN GUIDANCE ON EVOLUTION OF SURFACE LOW AND FRONT TIMING AS UPPER TROUGH SHIFTS EAST INTO THE PLAINS. THIS IS A REFLECTION OF MODEL DIFFERENCES ON EVOLUTION/TRACK OF CLOSED H5/H7 LOW CENTERS ACROSS THE PLAINS TODAY/TONIGHT. WE COULD SEE WIDE RANGING IMPACTS DEPENDING ON ALL OF THE ABOVE MENTIONED VARIANCES ON BOTH OUR RFW...A POSSIBLE WIND ADVISORY...AND POTENTIAL SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE NORTHERN HALF OF OUR CWA. THERE IS SO MUCH SPREAD BETWEEN MODELS FROM THE I-70 CORRIDOR NORTH ALL I WAS UNCOMFORTABLE DOING MORE THAN NUDGING TOWARDS THE LATEST BLENDS/NAM TRENDS. THIS PUTS THE SE HALF OF OUR CWA NEAR WIND ADVISORY CRITERIA...AND ANOTHER ROW OF COUNTIES WITHIN RFW CRITERIA. REGARDING THE CURRENT RFW AND POSSIBLE WIND ADVISORY...CONFIDENCE IS JUST TOO LOW TO MAKE HIGHLIGHT CHANGES. BASED ON EVOLUTION OF SURFACE FEATURES WE COULD SEE THUNDERSTORM INITIATION AND SEVERE POTENTIAL BY MIDDAY FURTHER SOUTH (I-70 CORRIDOR) BEFORE ANY PRIMARY THUNDERSTORM CHANCES TRANSITION NORTH AND WEST. WE WILL NEED TO MONITOR AND ADJUST AS CONFIDENCE INCREASE BASED ON REAL TIME DATA AND NEW RUNS OF SHORT RANGE GUIDANCE TO GET A BETTER HANDLE ON SENSIBLE WEATHER OVER OUR CWA THROUGH THIS EVENING. AS UPPER LOW TRANSITIONS EAST A COLD FRONT EVENTUALLY WILL PUSH SOUTH TONIGHT BEFORE STALLING ACROSS THE SOUTHERN PART OF OUR CWA. BESIDES COMPLICATING THE TEMP FORECAST...THIS FEATURE COULD ACT AS A FOCUS FOR ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT AS A SECONDARY SHORTWAVE TROUGH MOVES ACROSS THE NORTHERN PLAINS BEHIND THE INITIAL UPPER LOW. I USED A CONSENSUS BLEND OF TEMPS THROUGH FRI AND LINGERED POPS THROUGH FRI NIGHT TO ACCOUNT FOR LIFT/MOISTURE ALONG FRONT AND ASSOCIATE WITH WEAK TROUGH PASSAGE. WHILE TEMPS SHOULD RETURN TO NEAR SEASONAL VALUES...IT DOES LOOK LIKE WE HAVE POTENTIAL FOR LOW TEMPS TO DROP WELL BELOW NORMAL IN THE 30S...AND ACTUALLY WITHIN FROST ADVISORY CRITERIA. .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 215 AM MDT WED MAY 7 2014 WESTERLY ZONAL FLOW ALOFT WILL BE PRESENT ACROSS THE HIGH PLAINS SATURDAY...WHICH WILL BRING BENIGN CONDITIONS ACROSS THE FORECAST AREA. A POSITIVELY TILTED UPPER LEVEL TROUGH WILL BEGIN TO MOVE INTO THE GREAT BASIN REGION AND CONTINUE TO PROGRESS INTO THE TRI STATE AREA SATURDAY NIGHT. MODEL RUNS DIFFER AS TO THE LOCATION OF THE ENSUING TROUGH AS WELL AS THE TIMING OF THE PASSAGE OF THE TROUGH AXIS THROUGH THE REGION...BUT THIS WEATHER MAKING SYSTEM SHOULD AFFECT THE AREA SOMETIME BETWEEN THE SATURDAY NIGHT TO MONDAY NIGHT TIME FRAME. MOST MODEL FORECASTS INDICATE A SHORTWAVE RIDGE WILL MOVE INTO THE HIGH PLAINS ONCE THE TROUGH AXIS MOVES EASTWARD ON TUESDAY...BUT THE GEM MODEL HAS THE UPPER LEVEL LOW SYSTEM BECOMING CUT OFF OVER THE HIGH PLAINS REGION. TENDED TO SIDE WITH THE DRY FORECAST AS THE ECMWF...GFS AND DGEX FORECASTS INDICATE THE RIDGE. THE MAIN CONCERN FOR THE LONG TERM FORECAST PERIOD WILL BE THE CHANCES FOR THUNDERSTORMS SATURDAY NIGHT THROUGH MONDAY. THUNDERSTORMS AND PRECIPITATION CHANCES MAY LINGER INTO TUESDAY IF THE FLOW ALOFT BECOMES CUT OFF...WHICH WILL AID IN MORE PRECIPITATION PRODUCTION. LATEST MODEL FORECASTS PLACE THE GREATEST MID AND LOWER LEVEL JET SPEEDS AND HIGHEST AREAS OF INSTABILITY WELL TO THE EAST OF THE FORECAST AREA FOR THE PERIOD FOR GREATEST PRECIPITATION POTENTIAL...SO THUNDERSTORM ACTIVITY IS NOT EXPECTED TO BECOME SEVERE. DUE TO THE ZONAL FLOW PATTERN SATURDAY FOLLOWED BY A PUSH OF COOLER AIR ALOFT WITH THE TROUGH PATTERN...TEMPERATURES THROUGH THE LONG TERM PERIOD WILL BE NEAR TO SLIGHTLY BELOW NORMAL WITH HIGHS GENERALLY IN THE MID 60S TO LOWER 70S. LOW TEMPERATURES WILL SPAN DURING THIS PERIOD BETWEEN THE LOW TO UPPER 40S...WITH SOME SPOTS IN EASTERN COLORADO DIPPING INTO THE UPPER 30S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1142 AM MDT WED MAY 7 2014 VFR CONDITIONS ARE EXPECTED AT BOTH TERMINALS THROUGH THE PERIOD. THE WIND FORECAST IS QUITE CHALLENGING AND MAY REQUIRE AMENDMENTS THIS AFTERNOON. NORTHEASTERLY WINDS BEHIND A WEAK NEARLY STATIONARY FRONT HAVE PERSISTED THROUGH THE MORNING BUT SHOULD GRADUALLY TRANSITION TO SOUTHERLY AT GLD AS THE FRONT MOVES NORTHWARD. WINDS COULD BECOME GUSTY THIS AFTERNOON...ESPECIALLY AFTER 21Z LASTING INTO THE EARLY EVENING. AT KMCK WINDS ARE EXPECTED TO REMAIN EASTERLY/NORTHEASTERLY THROUGH THE FIRST PART OF THE NIGHT. AT BOTH TERMINALS A COLD FRONT WILL MOVE THROUGH LATE RESULTING IN A SHIFT TO NORTHWESTERLY WINDS...WITH GUSTS 30-35 KNOTS POSSIBLE...ESPECIALLY BY MID MORNING. THUNDERSTORMS WILL LIKELY FORM NORTH OF THE BOUNDARY LATE THIS AFTERNOON AND EVENING. THE GREATEST CHANCES WILL BE NORTHWEST OF BOTH TERMINALS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ013>016-027>029-041-042. WIND ADVISORY FROM 3 PM MDT /4 PM CDT/ THIS AFTERNOON TO 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ027>029-041-042. CO...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ253-254. WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 9 PM MDT THIS EVENING FOR COZ092. NE...NONE. && $$ UPDATE...BRB SHORT TERM...DR LONG TERM...MK AVIATION...BRB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1050 AM MDT WED MAY 7 2014 .UPDATE... ISSUED AT 1048 AM MDT WED MAY 7 2014 ISSUED A WIND ADVISORY FOR THE SOUTHERNMOST SIX COUNTIES FOR LATER THIS AFTERNOON THROUGH EARLY EVENING. DEEP MIXING SHOULD ALLOW FOR GUSTS TO REACH 45 MPH IN THIS AREA. STILL SOME UNCERTAINTY HOW FAR NORTH STRONGER WINDS WILL DEVELOP BUT THE GREATEST THREAT OF ADVISORY CRITERIA WINDS SHOULD STAY SOUTH OF INTERSTATE 70. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 225 AM MDT WED MAY 7 2014 EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW DEEPENING TROUGH CURRENTLY CENTERED OVER THE GREAT BASIN WITH SW FLOW EXTENDING ACROSS CENTRAL ROCKIES AND PLAINS. AT THE SURFACE LOW PRESSURE CURRENTLY EXTENDS FROM EASTCENTRAL COLORADO ACROSS THE TRI STATE REGION WITH A STATIONARY FRONT BISECTING THIS FEATURE GENERALLY ALONG AND SOUTH OF INTERSTATE 70. A DRY LINE EXTENDING ACROSS CENTRAL KS HAS BEEN BACKING UP TOWARDS THE EASTERN PART OF OUR CWA. PARTICULARLY LOW CONFIDENCE IN FORECAST FOR TODAY AS A RESULT OF THE LINGERING STATIONARY FRONT AND INCONSISTENCIES BETWEEN GUIDANCE ON EVOLUTION OF SURFACE LOW AND FRONT TIMING AS UPPER TROUGH SHIFTS EAST INTO THE PLAINS. THIS IS A REFLECTION OF MODEL DIFFERENCES ON EVOLUTION/TRACK OF CLOSED H5/H7 LOW CENTERS ACROSS THE PLAINS TODAY/TONIGHT. WE COULD SEE WIDE RANGING IMPACTS DEPENDING ON ALL OF THE ABOVE MENTIONED VARIANCES ON BOTH OUR RFW...A POSSIBLE WIND ADVISORY...AND POTENTIAL SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE NORTHERN HALF OF OUR CWA. THERE IS SO MUCH SPREAD BETWEEN MODELS FROM THE I-70 CORRIDOR NORTH ALL I WAS UNCOMFORTABLE DOING MORE THAN NUDGING TOWARDS THE LATEST BLENDS/NAM TRENDS. THIS PUTS THE SE HALF OF OUR CWA NEAR WIND ADVISORY CRITERIA...AND ANOTHER ROW OF COUNTIES WITHIN RFW CRITERIA. REGARDING THE CURRENT RFW AND POSSIBLE WIND ADVISORY...CONFIDENCE IS JUST TOO LOW TO MAKE HIGHLIGHT CHANGES. BASED ON EVOLUTION OF SURFACE FEATURES WE COULD SEE THUNDERSTORM INITIATION AND SEVERE POTENTIAL BY MIDDAY FURTHER SOUTH (I-70 CORRIDOR) BEFORE ANY PRIMARY THUNDERSTORM CHANCES TRANSITION NORTH AND WEST. WE WILL NEED TO MONITOR AND ADJUST AS CONFIDENCE INCREASE BASED ON REAL TIME DATA AND NEW RUNS OF SHORT RANGE GUIDANCE TO GET A BETTER HANDLE ON SENSIBLE WEATHER OVER OUR CWA THROUGH THIS EVENING. AS UPPER LOW TRANSITIONS EAST A COLD FRONT EVENTUALLY WILL PUSH SOUTH TONIGHT BEFORE STALLING ACROSS THE SOUTHERN PART OF OUR CWA. BESIDES COMPLICATING THE TEMP FORECAST...THIS FEATURE COULD ACT AS A FOCUS FOR ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT AS A SECONDARY SHORTWAVE TROUGH MOVES ACROSS THE NORTHERN PLAINS BEHIND THE INITIAL UPPER LOW. I USED A CONSENSUS BLEND OF TEMPS THROUGH FRI AND LINGERED POPS THROUGH FRI NIGHT TO ACCOUNT FOR LIFT/MOISTURE ALONG FRONT AND ASSOCIATE WITH WEAK TROUGH PASSAGE. WHILE TEMPS SHOULD RETURN TO NEAR SEASONAL VALUES...IT DOES LOOK LIKE WE HAVE POTENTIAL FOR LOW TEMPS TO DROP WELL BELOW NORMAL IN THE 30S...AND ACTUALLY WITHIN FROST ADVISORY CRITERIA. .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 215 AM MDT WED MAY 7 2014 WESTERLY ZONAL FLOW ALOFT WILL BE PRESENT ACROSS THE HIGH PLAINS SATURDAY...WHICH WILL BRING BENIGN CONDITIONS ACROSS THE FORECAST AREA. A POSITIVELY TILTED UPPER LEVEL TROUGH WILL BEGIN TO MOVE INTO THE GREAT BASIN REGION AND CONTINUE TO PROGRESS INTO THE TRI STATE AREA SATURDAY NIGHT. MODEL RUNS DIFFER AS TO THE LOCATION OF THE ENSUING TROUGH AS WELL AS THE TIMING OF THE PASSAGE OF THE TROUGH AXIS THROUGH THE REGION...BUT THIS WEATHER MAKING SYSTEM SHOULD AFFECT THE AREA SOMETIME BETWEEN THE SATURDAY NIGHT TO MONDAY NIGHT TIME FRAME. MOST MODEL FORECASTS INDICATE A SHORTWAVE RIDGE WILL MOVE INTO THE HIGH PLAINS ONCE THE TROUGH AXIS MOVES EASTWARD ON TUESDAY...BUT THE GEM MODEL HAS THE UPPER LEVEL LOW SYSTEM BECOMING CUT OFF OVER THE HIGH PLAINS REGION. TENDED TO SIDE WITH THE DRY FORECAST AS THE ECMWF...GFS AND DGEX FORECASTS INDICATE THE RIDGE. THE MAIN CONCERN FOR THE LONG TERM FORECAST PERIOD WILL BE THE CHANCES FOR THUNDERSTORMS SATURDAY NIGHT THROUGH MONDAY. THUNDERSTORMS AND PRECIPITATION CHANCES MAY LINGER INTO TUESDAY IF THE FLOW ALOFT BECOMES CUT OFF...WHICH WILL AID IN MORE PRECIPITATION PRODUCTION. LATEST MODEL FORECASTS PLACE THE GREATEST MID AND LOWER LEVEL JET SPEEDS AND HIGHEST AREAS OF INSTABILITY WELL TO THE EAST OF THE FORECAST AREA FOR THE PERIOD FOR GREATEST PRECIPITATION POTENTIAL...SO THUNDERSTORM ACTIVITY IS NOT EXPECTED TO BECOME SEVERE. DUE TO THE ZONAL FLOW PATTERN SATURDAY FOLLOWED BY A PUSH OF COOLER AIR ALOFT WITH THE TROUGH PATTERN...TEMPERATURES THROUGH THE LONG TERM PERIOD WILL BE NEAR TO SLIGHTLY BELOW NORMAL WITH HIGHS GENERALLY IN THE MID 60S TO LOWER 70S. LOW TEMPERATURES WILL SPAN DURING THIS PERIOD BETWEEN THE LOW TO UPPER 40S...WITH SOME SPOTS IN EASTERN COLORADO DIPPING INTO THE UPPER 30S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 545 AM MDT WED MAY 7 2014 EARLY IN THE TAF PERIODS LOW LEVEL MOISTURE POOLING NORTH OF STATIONARY FRONT WILL LEAD TO VIS VARYING FROM 4-7SM OVER NW KS AND SW NE THROUGH ABOUT 15Z. NOT CONFIDENT ENOUGH TO PUT MVFR VIS IN TAF...SO LIMITED VIS RESTRICTION TO 6SM AS THIS LIGHT FOG IS FAIRLY PATCHY. AS FRONT LIFTS NORTH TODAY AND SURFACE LOW DEEPENS GUSTY SOUTH WINDS WILL DEVELOP WITH GUSTS TO 30KT AT KGLD AND AROUND 20-25KT AT MCK. A LOT OF SPREAD ON GUIDANCE ON TIMING OF THIS FRONT AND A POTENTIAL COLD FRONT TONIGHT. FOR NOW SHOWED WIND SHIFT TO W-NW TONIGHT AT BOTH TERMINALS BASED ON LATEST NAM/RAP. WITH SLOWER WARM FRONT IT LOOKS LIKE A FEW THUNDERSTORMS COULD DEVELOP AROUND BOTH TERMINALS...HOWEVER AT THIS TIME CONFIDENCE WAS TOO LOW IN INITIATION OR COVERAGE TO ADD MENTION TO TAFS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ013>016-027>029-041-042. WIND ADVISORY FROM 3 PM MDT /4 PM CDT/ THIS AFTERNOON TO 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ027>029-041-042. CO...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ253-254. WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 9 PM MDT THIS EVENING FOR COZ092. NE...NONE. && $$ UPDATE...BRB SHORT TERM...DR LONG TERM...MK AVIATION...DR
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
401 PM EDT WED MAY 7 2014 .SYNOPSIS... A WEAK FRONTAL BOUNDARY WILL LIFT NORTH AS A WARM FRONT TONIGHT INTO THURSDAY MORNING. HIGH PRESSURE WILL BECOME ANCHORED OFF THE SOUTHEAST COAST THURSDAY AFTERNOON THROUGH FRIDAY...AS THE FRONTAL BOUNDARY LINGERS ALONG THE MID ATLANTIC COAST. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... MID-AFTERNOON WX ANALYSIS FEATURES ~1024MB SFC HIGH PRESSURE OVER ON/QC, RIDGING SOUTHEAST INTO THE NORTHEAST/MID-ATLANTIC REGION, WITH A QUASI-STATIONARY FRONTAL BOUNDARY STILL IN PLACE FROM SE NC BACK INTO THE CENTRAL APPALACHIANS. ALOFT, UPPER AIR ANALYSIS SHOWS A DEEP TROUGH IN PLACE OVER THE INTERMOUNTAIN WEST, AND A SECOND DEPARTING TROUGH OVER ATLANTIC CANADA. MID/UPPER LEVEL RIDGE AXIS CONTINUES TO TRANSLATE EASTWARD TODAY, ORIENTED FROM THE SOUTHEAST INTO THE OHIO VALLEY. QUICK MOVING SHORTWAVE TROUGH PINWHEELED FROM WESTERN PA/MD ACROSS TO THE LOWER EASTERN SHORE BY MID AFTERNOON. MUCH OF THIS ACTIVITY HAS PUSHED OFFSHORE, BUT HAVE RETAINED SOME ISO TO SCT SHRA WORDING FOR THE BALANCE OF THE AFTN/EARLY EVENING AS THIS AREA REMAINS ON THE SOUTHERN PERIPHERY OF DEEPER LAYER MOISTURE AS UPPER RIDGE EDGES NORTHEAST THROUGH TONIGHT. OTHERWISE, EXPECT A DRY AFTN/EVENING. SW FLOW OVER THE SOUTHERN PLAINS AND SOUTHEAST WILL SHUNT THE STATIONARY FRONT BACK TO THE NORTH TNGT AND OVERNIGHT AS A WARM FRONT. A SECOND, MORE DEFINED SHORTWAVE TROUGH TRACKS THROUGH THE NW FLOW TONIGHT INTO EARLY THURSDAY. HOWEVER, AS THE UPPER RIDGE AND SFC WARM FRONT SLIP NORTH, THE BEST POTENTIAL FOR SHOWERS/TSTMS WILL SHIFT INTO PA/NJ/NRN DE/FAR NE MD. DID RETAIN A LOW POP GIVEN THAT THE EASTERN SHORE AND NRN NECK WILL REMAIN CLOSE ENOUGH TO THE MID-LEVEL FORCING TO INCLUDED A 20-30% POP BUT EXPECT MOST OF THE NIGHT TO BE DRY EVEN OVER THESE AREAS. LEANED TOWARDS HIGHER ENVELOPE OF MOS GUIDANCE GIVEN PERSISTENT MID LVL CLOUDINESS...AS WELL WHAT WILL LIKELY BE AREAS OF STRATUS ACROSS THE COASTAL PLAIN OVERNIGHT AS THE FRONT SLIPS NORTH. LOOK FOR EARLY MORNING LOWS IN THE LOWER TO MIDDLE 60S FOR MOST...U50S TO NEAR 60 EASTERN SHORE. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... CLOUDS WL GRADUALLY DECREASE FROM SW-NE THURSDAY...BUT EXPECT CLOUDS TO LINGER FOR MUCH OF THE DAY OVER THE EASTERN SHORE AS FRONT REMAINS SLOW TO LIFT ACROSS NORTHEAST COASTAL PLAIN GIVEN PERSISTENT LLVL EASTERLY FLOW OFF OF THE STILL QUITE CHILLY ATLANTIC COASTAL WATERS. MEANWHILE BEHIND THE FRONT, EXPECT THURSDAY TO BE THE WARMEST DAY OF THE YEAR SO FAR W OF THE BAY. EXPECT HIGHS RANGING FROM THE MID 80S TO AROUND 90. HIGHS OVER THE EASTERN SHORE SHOULD RANGE FROM THE LOW/MID 70S ALONG THE IMMEDIATE ATLANTIC COAST...TO THE UPPER 70S/AROUND 80 INLAND. THE FRONT MAY ACTUALLY DROP BACK S INTO THE EASTERN SHORE AS A BACKDOOR COLD FRONT THURSDAY NIGHT INTO EARLY FRIDAY...BEFORE RETREATING NNE FRIDAY AFTERNOON. NAM/GFS BUFR AT SBY SOUNDINGS SUGGEST SOME STRATUS COULD COME INLAND FROM THE OCEAN. THIS AND THE ULTIMATE PLACEMENT OF THE FRONT WILL HAVE A LARGE INFLUENCE ON HIGHS FRIDAY. WITH UPPER RIDGING IN PLACE FROM THE MID-ATLANTIC WELL NORTH INTO EASTERN CANADA, AND SURFACE HIGH ALONG/JUST OFFSHORE...EXPECT ANOTHER VERY WARM TO HOT DAY INLAND ON SW WINDS. ALSO LOOK FOR A BIT MORE IN THE WAY OF INSTABILITY, AS HIGH RES MODELS ARE BEGINNING TO HOOK ON TO SOME SUBTLE LEE TROUGHING FRIDAY AFTN/EVENING. GIVEN THAT DOWNSLOPE FLOW MAY WELL MAKE IT TOO DRY FOR WIDESPREAD OR EVEN ORGANIZED CONVECTIVE DEVELOPMENT, WILL CAP POP AT SILENT FOR RIGHT NOW. HOWEVER, WILL NEED TO KEEP AN EYE OUT FOR SOME ISOLATED, DISORGANIZED CONVECTION FIRING ACROSS THE WEST ON FRIDAY AFTN/EVENING. HIGHS WARM RIGHT BACK INTO THE 80S TO NEAR 90 WEST OF THE BAY...WITH U70S TO LOWER 80S OVER THE EASTERN SHORE. GOOD AGREEMENT AMONGST MODELS IN WASHING OUT NEXT COLD FRONT TO THE WEST IN WARM/DRY QUASI-ZONAL FLOW. WILL SEE A BIT MORE IN THE WAY OF SOME DIURNALLY DRIVEN, WIDELY SCT THUNDERSTORMS. HOWEVER, ONCE AGAIN DYNAMICS AND INSTABILITY OVER OUR REGION APPEAR AS IF THEY WILL BE RATHER MEAGER. HIGHS GENERALLY BACK INTO THE 80S INLAND...70S TO NEAR 80 OVER THE EASTERN SHORE. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... EARLY SUMMER PATTERN SETTING UP AS BERMUDA RIDGE HOLDS FIRM ACROSS THE AREA THRU MID WEEK. WASHED OUT FRONTAL BOUNDARY WILL COMBINE WITH ANY RESIDUAL CONVECTIVE BOUNDARIES SUN THRU TUES. UPSHOT WILL BE LOW CHCS (20-30%) FOR AFTN/EVENING SHRAS/TSTMS EACH DAY. HIGHS SUN U70S-L80S XCPT L-M70S AT THE BEACHES. HIGH MON/TUES 80-85...XCPT 75-80 CSTL AREAS. LOWS GNRLY 60-65. MODELS DEPICT NEXT FRONTAL BOUNDARY CROSSING THE AREA WED. THIS PRBLY THE BEST CHC FOR ANY WDSPRD PCPN AS IT APPEARS THAT SOME TROPICAL MSTR GETS TRANSPORTED NORTH ALONG IT. KEPT POPS IN CHC CATEGORY FOR NOW GIVEN 7 DAYS OUT. HIGHS WED 75-80. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... THE FRONTAL BOUNDARY TO THE SOUTH WILL SLOWLY MOVE BACK NORTH STARTING TONIGHT. THE 85H FRONTAL IS MOVING NORTH OF THE AREA THIS AFTERNOON. THIS HAD SOME SHOWERS AND THUNDERSTORMS WHICH MOVED INTO THE DELMARVA THIS AFTERNOON. THE 85H FRONT WILL BE WELL NORTH OF THE AREA LATER TONIGHT SO ANY SHOWERS THAT FORM ALONG IT WILL BE TO THE NORTH OF THE AREA. THE FRONT TO THE SOUTH HAS SOME LOW LEVEL MOISTURE WITH IT. THIS COULD BRING CIGS DOWN TO MVFR OVERNIGHT TONIGHT AS THE BOUNDARY SLOWLY WORKS NORTH. LOOKING AT RUC AND NAM ON BUFKIT CAN SEE CLOUDS LOWERING AFTER MIDNIGHT ACROSS ALL TAF SITES. NOT COMPLETELY CONVINCED THE ALL THIS LOW LEVEL MOISTURE WILL RETURN. SO WILL ONLY BRING MVFR CONDITIONS IN AFTER MIDNIGHT THROUGH SUNRISE. POTENTIAL FOR THESE CLOUDS TO BE LOWER LATE TONIGHT AND AT SUNRISE. AFTER SUNRISE CLOUDS RISE QUICKLY AND DISSIPATE AT ALL SITES AS THE WARM FRONT MOVES NORTH OF THE AREA. THIS WILL ALLOW FOR VFR CONDITIONS ON THURSDAY. EXPECT MAINLY VFR CONDITIONS THROUGH THE WEEKEND BUT SCATTERED THUNDERSTORMS WILL DEVELOP BOTH SATURDAY AND SUNDAY AFTERNOON WHICH COULD BE IFR CONDITIONS FOR A SHORT TIME TO THE TAF SITES. && .MARINE... SFC PRESSURE GRADIENT BTWN THE S/W TO THE NORTH AND FRNTL BNDRY TO THE SOUTH RESULTING IN WINDS AROUND 15 KT WITH A FEW GUSTS TO 20 KTS OVER THE SRN MOST PART OF THE CHES BAY ATTM. THESE CNDTNS XPCTD TO CONT THRU LATE AFTRN BEFORE DMNSHG TONIGHT. NO SCA ANTICIPATED ATTM. WARM FRONT PROGGED TO LIFT NORTH OVER THE WATERS TONIGHT AND THU. FLOW BECOMES S-SW AND PREVAILS THRU THE WEEKEND AS HIGH PRESSURE ANCHORS OVER THE WRN ATLANTIC. WINDS AOB 15 KTS...SEAS 2-4 FT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...AJZ/MAM LONG TERM...MPR AVIATION...JAB MARINE...SAM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
258 PM EDT WED MAY 7 2014 .SYNOPSIS... A FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS NORTH CAROLINA TODAY. THE FRONT LIFTS NORTH AS A WARM FRONT TONIGHT INTO THURSDAY MORNING. HIGH PRESSURE WILL BECOME ANCHORED OFF THE SOUTHEAST COAST THURSDAY AFTERNOON THROUGH FRIDAY...AS THE FRONTAL BOUNDARY LINGERS ALONG THE MID ATLANTIC COAST. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MID-MORNING WX ANALYSIS FEATURES ~1024MB SFC HIGH PRESSURE OVER JAMES BAY NOSING SOUTH INTO THE NORTHEAST/MID-ATLANTIC REGION, WITH A QUASI-STATIONARY FRONTAL BOUNDARY DRAPED WELL SOUTH INTO THE CAROLINAS. ALOFT, WV/IR IMAGERY SHOWING UPPER LEVEL RIDGE AXIS EXTENDING FROM THE SOUTHEAST INTO THE TN RVR VALLEY THIS MORNING...WITH A DEEP TROUGH IN PLACE OVER THE INTERMOUNTAIN WEST, AND A SECOND DEPARTING TROUGH OVER ATLANTIC CANADA. CONTINUING TO SEE SOME CLUSTERS OF CONVECTIVE SHRAS/ISO T IN ASSOCIATION WITH SHORTWAVE ENERGY EJECTING FROM THE TROUGH OVER THE WEST. THIS ACTIVITY IS EXPECTED TO RIDE THE NW FLOW PATTERN ALOFT FROM W PA INTO THE MID ATLANTIC REGION BY THIS AFTN. WHILE DYNAMICS ARE LESS THAN FAVORABLE FOR ANY SIGNIFICANT/WIDESPREAD TSTM DEVELOPMENT (DIMINISHING EFFECTIVE SHEAR/PERSISTENT MID- LEVEL CAPPING/MODEST MLCAPE <500 J/KG), EXPECT SOME SCT SHRAS WL MAKE IT ACROSS AS WEAKENING VORTMAX SWINGS ACROSS THE MASON-DIXON LINE THROUGH THIS AFTN. LATEST HRRR SEEMS TO BE PERFORMING WELL ALONGSIDE LATEST SAT/RADAR TRENDS, AND HV THEREFORE INSTALLED SOME CHC/"SCT" POPS FOR EASTERN SHORE COUNTIES AND FAR NE VA NORTHERN NECK COUNTIES, MAINLY ALONG AND NORTH OF US-360. OTEHRWISE, EXPECT A DRY DAY FOR MOST OF THE AREA, WITH LITTLE OR NO FOCUS FOR ADDITIONAL CONVECTIVE DEVELOPMENT. DEVELOPING SW FLOW OVER THE SOUTHERN PLAINS AND SOUTHEAST SHOULD ALLOW THE STATIONARY FRONT TO SHIFT BACK TO THE NORTH THIS AFTN/TNGT AS A WARM FRONT, WITH MID-HIGH CLOUDS MOVING FROM SW-NE THROUGH THE DAY. HOWEVER, THE FRONT SHOULD REMAIN S OF THE LOCAL AREA THROUGH 00Z/8P EDT. HIGHS SHOULD RANGE FROM THE UPPER 60S TO AROUND 70 OVER THE EASTERN SHORE...TO THE MID/UPPER 70S FROM INTERIOR NE NC TO CENTRAL VA. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... THE STATIONARY FRONT LIFTS NNE LATE TONIGHT INTO THURSDAY MORNING THROUGH MOST OF THE AREA...BEFORE STALLING IN VICINITY OF THE LOWER MD EASTERN SHORE. A SECOND, MORE DEFINED SHORTWAVE TROUGH TRACKS THROUGH THE NW FLOW TONIGHT INTO EARLY THURSDAY. THE BEST POTENTIAL FOR SHOWERS/TSTMS WILL BE OVER PA/NJ/NRN DE/FAR NE MD. HOWEVER...PORTIONS OF THE LOCAL AREA (EASTERN SHORE AND NRN NECK) ARE CLOSE ENOUGH TO THE MID-LEVEL FORCING TO INCLUDED A 20-30% POP. THUNDER WILL BE INCLUDED BASED ON UPSTREAM ACTIVITY...MODESTLY STEEP MID-LEVEL LAPSE RATES...AND THETA-E RIDGING EXTENDING N FROM THE SUBTROPICAL WRN ATLANTIC. CLOUDS SHOULD GRADUALLY DECREASE FROM SW-NE THURSDAY...BUT THE LOWER MD EASTERN SHORE COULD REMAIN MOSTLY CLOUDY THROUGH THE DAY. THURSDAY HAS THE POTENTIAL TO BE THE WARMEST DAY OF THE YEAR SO FAR W OF THE BAY...WITH HIGHS RANGING FROM THE MID 80S TO AROUND 90. HIGHS OVER THE EASTERN SHORE SHOULD RANGE FROM THE LOW/MID 70S ALONG THE IMMEDIATE ATLANTIC COAST...TO THE UPPER 70S/AROUND 80 INLAND. THE FRONT MAY ACTUALLY DROP BACK S INTO THE EASTERN SHORE AS A BACKDOOR COLD FRONT THURSDAY NIGHT INTO EARLY FRIDAY...BEFORE RETREATING NNE FRIDAY AFTERNOON. THIS WILL MAKE FOR A CHALLENGING TEMPERATURE/SKY COVER FORECAST. NAM/GFS BUFR AT SBY SOUNDINGS SUGGEST SOME STRATUS COULD COME INLAND FROM THE OCEAN. THIS AND THE ULTIMATE PLACEMENT OF THE FRONT WILL HAVE A LARGE INFLUENCE ON HIGHS FRIDAY. THE CURRENT FORECAST IS FOR HIGHS AROUND 70 ALONG THE COAST...TO MID/UPPER 70S FOR INTERIOR PORTIONS. ELSEWHERE...EXPECT A SUNNY AND WARM DAY WITH HIGHS IN THE MID/UPPER 80S (LOCALLY LOW 80S COASTAL SE VA/NE NC). && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... BERMUDA HIGH PRESSURE REMAINS ANCHORED OFF THE SERN COAST THROUGH THE WEEKEND. LATEST MODEL DATA SLOWS THE APPRCH OF NEXT FRNT ACROSS THE MTS UNTIL SUNDAY. KEPT FRI NIGHT/SAT MORNING DRY. SCT CONVECTION PSBL INVOF LEE TROF RESULTING IN DIURNAL POPS SAT AFTN/EVE. LOWS FRI NIGHT L-M60S. HIGHS SAT 80-85...XCPT M-U70S COASTAL AREAS. FRONT APPRCHS THE AREA SAT NIGHT THEN WEAKENS/WASHES OUT ACROSS THE MID ATLNTC RGN SUNDAY. HOWEVER...MODELS NOW WANT TO KEEP THIS WEAKEN BNDRY/TROF HANGING ARND THE RGN THROUGH ERLY NEXT WEEK. GIVEN THIS TRIGGER...KEPT CHC SHWRS/TSTMS (20-40%...HIGHEST W OF BAY) IN FCST THROUGH THE PRD. HIGHS EACH DAY 80-85 EXCEPT REMAINING IN THE 70S COASTAL SECTIONS. LOWS U50S-M60S. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... THE FRONTAL BOUNDARY TO THE SOUTH WILL SLOWLY MOVE BACK NORTH STARTING TONIGHT. THE 85H FRONTAL IS MOVING NORTH OF THE AREA THIS AFTERNOON. THIS HAD SOME SHOWERS AND THUNDERSTORMS WHICH MOVED INTO THE DELMARVA THIS AFTERNOON. THE 85H FRONT WILL BE WELL NORTH OF THE AREA LATER TONIGHT SO ANY SHOWERS THAT FORM ALONG IT WILL BE TO THE NORTH OF THE AREA. THE FRONT TO THE SOUTH HAS SOME LOW LEVEL MOISTURE WITH IT. THIS COULD BRING CIGS DOWN TO MVFR OVERNIGHT TONIGHT AS THE BOUNDARY SLOWLY WORKS NORTH. LOOKING AT RUC AND NAM ON BUFKIT CAN SEE CLOUDS LOWERING AFTER MIDNIGHT ACROSS ALL TAF SITES. NOT COMPLETELY CONVINCED THE ALL THIS LOW LEVEL MOISTURE WILL RETURN. SO WILL ONLY BRING MVFR CONDITIONS IN AFTER MIDNIGHT THROUGH SUNRISE. POTENTIAL FOR THESE CLOUDS TO BE LOWER LATE TONIGHT AND AT SUNRISE. AFTER SUNRISE CLOUDS RISE QUICKLY AND DISSIPATE AT ALL SITES AS THE WARM FRONT MOVES NORTH OF THE AREA. THIS WILL ALLOW FOR VFR CONDITIONS ON THURSDAY. EXPECT MAINLY VFR CONDITIONS THROUGH THE WEEKEND BUT SCATTERED THUNDERSTORMS WILL DEVELOP BOTH SATURDAY AND SUNDAY AFTERNOON WHICH COULD BE IFR CONDITIONS FOR A SHORT TIME TO THE TAF SITES. && .MARINE... STALLED FRONTAL BOUNDARY REMAINS DRAPED OVER THE CAROLINAS AS HIGH PRESSURE OVER SE CANADA RIDGES SWD OVER THE WATERS. THE RESULT IS LIGHT SELY FLOW AOB 10 KT OVER THE WATERS WITH WAVES AND SEAS GENERALLY 1-2 FT. HIGH PRESSURE LOCATES JUST OFF THE MID-ATLANTIC COAST THIS AFTERNOON AS THE STALLED FRONTAL BOUNDARY BEGINS TO LIFT NWD AS A WARM FRONT. AS THIS OCCURS...A WEAK WAVE OF LOW PRESSURE WILL LIFT ALONG THE FRONT...RESULTING IN A STRENGTHENING PRESSURE GRADIENT OVER THE WATERS. WINDS ALOFT WILL INCREASE TO 20-25 KT...BUT COOL WATERS AND WARM TEMPS ALOFT WILL RESULT IN AN INVERSION OVER THE WATERS...PREVENTING THE STRONGER WINDS FROM MIXING TO THE WATER. HOWEVER...ENOUGH OF A SFC PRESSURE GRADIENT WILL RESULT IN WINDS AROUND 15 KT OVER THE BAY LATE TODAY INTO EARLY TONIGHT BEFORE DIMINISHING AFTER MIDNIGHT. A FEW GUSTS UP TO 18-20 KT ARE POSSIBLE...BUT SCA CONDITIONS ARE NOT ANTICIPATED. WARM FRONT LIFTS OVER THE WATERS TONIGHT INTO THURS...WITH FLOW BECOMING S-SW BEHIND THE FRONT. SW FLOW PREVAILS THRU THE WEEKEND AS HIGH PRESSURE ANCHORS OVER THE WRN ATLANTIC...RESULTING IN ONGOING SUB-SCA CONDITIONS. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...AJZ NEAR TERM...AJZ/MAM SHORT TERM...AJZ LONG TERM...MPR AVIATION...JAB MARINE...SAM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
457 PM EDT WED MAY 7 2014 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 407 PM EDT WED MAY 7 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW FAIRLY HI AMPLITUDE RDG BLDG FM THE SE CONUS INTO THE UPR LKS DOWNSTREAM OF A DEEP TROF IN THE ROCKIES. THERE ARE TWO CLOSED LOWS EMBEDDED IN THE TROF. ONE LO IS CENTERED OVER SASKATCHEWAN AND THE OVER THE DESERT SW. THE LO OVER THE DESERT SW WL HAVE THE MOST IMPACT ON UPR MI WX. WARM FNT TO THE E OF ASSOCIATED LO PRES IN THE CENTRAL PLAINS IS EXTENDING E THRU IOWA TOWARD THE LOWER LKS...WITH H85 FNT MOVING N INTO SRN MN/WI. A PAIR OF ELEVATED CONVECTIVE CLUSTERS THAT MOVED ENEWD WELL N OF THE WARM FNT IMPACTED MAINLY THE SCENTRAL COUNTIES THIS MRNG/EARLY AFTN...BUT LINGERING DRY AIR BEST DEPICTED ON THE 12Z APX RAOB AND HIER STABILITY THAT IS PRESENT FARTHER TO THE N PER LATEST SPC MESOANALYSIS LIMITED THE N PUSH OF THESE SHRA/TS INTO THE CWA. ABSENCE OF DYNAMIC FORCING OTHER THAN SOME GENERAL WAD/ ISENTROPIC ASCENT UNDER BLDG UPR RDG SO FAR TO THE NE OF MAIN FORCING MECHANISM CLOSER TO THE DESERT SW UPR LO IS RESULTING IN MAINLY DRY WX THIS AFTN...WITH MAINLY JUST THICKER HI CLDS IMPACTING AREAS AWAY FM THE SCENTRAL. MAIN FCST CONCERNS THRU THU INVOLVE POPS/ELEVATED TS CHCS AND INTENSITY TO THE N OF APRCHG SFC LO/ATTENDANT WARM FNT AS WELL AS POTENTIAL FOR FOG DVLPMNT. TNGT...UPR LO OVER THE DESERT SW IF FCST TO MOVE TO THE NE AND REACH THE WCENTRAL PLAINS BY 12Z THU. AS THE SFC LO SHIFTS SLOWLY TO THE NE AS WELL...ATTENDANT SFC WARM FNT IS FCST TO MOVE ONLY SLOWLY TO THE N INTO SCNTRL WI...BUT THE H85 FNT IS PROGGED TO LIFT MORE QUICKLY N THRU THE CWA. THE MOST APPRECIABLE DEEP LYR QVECTOR CNVGC/ UPR DVCG THAT IS NOW SUPPORTING MORE NMRS SHRA/SOME TS OVER THE NRN PLAINS INTO WRN MN IS FCST TO SWING INTO THE AREA FM THE W THIS EVNG AND IMPACT MAINLY THE NW PORTION OF THE CWA BEFORE EXITING TO THE NE LATER. AT LEAST SCT SHRA/SOME TS WL LIKELY SHIFT FARTHER TO THE ESE PARALLEL TO THE APRCHG H85 WARM FNT IN LINE WITH FCST CORFIDI VECTORS AND TOWARD STEEPER H7-5 LAPSE RATES. SINCE THE CONVECTION WL BE ELEVATED...PWAT WL BE APRCHG 200 PCT OF NORMAL AS WARMER/MOISTER AIR WITH H85 DEWPTS UP TO 12C FOLLOWING THE WARM FNT...AND FCST SDNGS IN THE MORE SATURATED AIRMASS SHOW THIN SKINNY CAPE...SUSPECT HEAVY RA WL BE THE MAIN THREAT. BUT SOME HAIL MAY FALL OVER THE STRONGER CELLS MAINLY NEAR THE SRN END OF THE SHRA AREA...WHERE FCST SDNGS SHOW STEEPER MID LVL LAPSE RATES /ALBEIT WITH A BIT MORE OF A CAP/ AND H85-3 WIND SHEAR IN THE ELEVATED UNSTABLE LYR IS AOA 40-50 KTS. THIS CAPPING WL BECOME MORE PRONOUNCED LATER FOLLOWING THE H85 WARM FROPA AND TEND TO DIMINISH POPS FM THE SW. AS THE LLVLS TO THE N OF INCRSGLY SHALLOW WARM FNT INVRN MOISTEN...EXPECT SOME FOG TO DVLP LATE...MAINLY WHERE THE EXPECTED ESE NEAR SFC FLOW UPSLOPES OFF LK MI. BUT TENDED TO CUT BACK ON THE FOG FCST TO ACCOUNT FOR STILL VERY DRY LLVLS. WITH INCRSG MSTR AND THE APRCH OF THE WARM FNT... EXPECT LTL DIURNAL TEMP FALL. THU...AS SHRTWV LIFTS TO THE NE AND INTO THE NRN PLAINS BY 00Z FRI...SFC LO IS FCST TO MOVE INTO SW MN BY 00Z FRI...WITH SFC WARM FNT TO THE E ARPCHG THE WI BORDER LATE. EXPECT PLENTY OF LO CLD TO THE N OF INCRSGLY SHALLOW WARM FNTL INVRN WITH SOME FOG AS WELL IN AREAS THAT EXPERIENCE UPSLOPE FLOW WITH THE LLVL SE WIND TO THE N OF THE FNT. BEST CHC FOR MORE NMRS SHRA/TS WL BE IN THE MRNG OVER THE NE HALF BEFORE CAPPING BEHIND H85 WARM FROPA/AREA OF DEEP LYR FORCING SHIFT TO THE NE AND GIVE WAY TO LARGER SCALE QVECTOR DVGC/ STRENGTHENING OF CAPPING INVRN. PREFER THE 12Z REGIONAL CNDN MODEL HANDLING OF THE POPS SHIFTED A BIT TO THE NE TOWARD THE LARGER SCALE FORCING AND AWAY FM LIKELY CAP. BEST CHC FOR SOME SUNSHINE WL BE OVER THE W IN THE AFTN WITH DOWNSLOPE SE WIND UNDER MID LVL CAPPING/ DRYING. HI TEMPS WL AT LEAST APRCH 70 IN THIS AREA. LINE OF SHRA/TS FED BY THIS HEATING AND CLOSER APRCH OF THE LO MAY MOVE INTO THE FAR W LATE IN THE DAY. THE CURRENT SPC OUTLOOK INDICATES FAR WRN UPR MI IS UNDER THE SLGT RISK FOR SVR STORMS. WITH SFC-6KM BULK SHEAR VALUES APRCHG 40-50KTS TOWARD 00Z IN THIS AREA AT THE TIME THE LINE OF CVNCTN MIGHT BE ARRIVING LATE IN THE DAY AHEAD OF THE SHARPER DEEP LYR QVECTOR CNVGC AND FCST MUCAPE AOA 1000J/KG...STRONGER STORMS WL BE PSBL IF SFC BASED PARCELS CAN BREAK THRU THE CAP. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 449 PM EDT WED MAY 7 2014 MODELS ADVERTISE A FAIRLY ACTIVE SPRING WEATHER PATTERN FOR THE UPPER GREAT LAKES REGION FROM LATE THIS WEEK INTO THE FIRST HALF OF NEXT WEEK AS A MEAN MID-UPPER LEVEL TROUGH PERSISTS OVER THE WESTERN HALF OF THE CONTINENT ALLOWING FOR A SERIES OF SW FLOW SHORTWAVES TO BRING PERIODIC SHOWERS TO THE FCST AREA. BEGINNING THU NIGHT INTO FRI...A SHORTWAVE NOW NEAR THE AZ/MEXICO BORDER ROUNDING THE BASE OF THE WRN CONUS TROF IS EXPECTED TO LIFT NE THROUGH THE SRN ROCKIES AND CENTRAL PLAINS TONIGHT INTO THURSDAY. MODELS INDICATE THIS SHORTWAVE AND ITS ASSOC 3H JET MAX WILL TRACK ACROSS WESTERN LAKE SUPERIOR THU NIGHT INTO FRI MORNING WITH THE BEST MID-LVL Q-VECT CONVERGENCE AND UPPER DIVERGENCE STAYING NW OF THE FCST AREA. BUT DESPITE THE LACK OF FAVORABLE DYNAMICS OVER THE AREA...THE SHORTWAVE WILL DRIVE A WARM FRONT TOWARD THE UPPER GREAT LAKES LATE THU AND THEN PUSH THE SFC LOW AND ASSOC COLD FRONT INTO THE WRN PORTION OF THE CWA LATE THU NIGHT INTO EARLY FRI INCREASING LOW-LVL CONVERGENCE. DEPENDING ON EVOLUTION OF CONVECTION ALONG INCOMING WARM FRONT...POOLING OF LOW-LVL MOISTURE AND SOME ELEVATED INSTABILITY TO NEAR 500 J/KG ALONG WITH BULK SHEAR VALUES TO NEAR 40 KT COULD RESULT IN SOME STRONGER STORMS MAINLY NEAR THE WI BDR COUNTIES THU EVENING. HOWEVER...GIVEN HOW CAPPED LOW- LEVELS ARE FROM FCST SNDGS WOULD THINK THREAT OF SVR WOULD BE PRETTY MINIMAL. OTHERWISE...WEAKENING INSTABILITY SHOULD RESULT IN JUST A GENERAL THUNDERSTORM RISK LATE THU NIGHT INTO FRIDAY ALONG AND AHEAD OF COLD FRONTAL PASSAGE. FRI NIGHT AND SATURDAY...EXPECT DRIER CONDITIONS AS A MID-LVL SHORTWAVE RIDGE AND ASSOC SFC RDG BUILD IN FM WEST BEHIND THE FRIDAYS FRONTAL SYSTEM. TEMPS RIGHT ALONG LAKE SUPERIOR WILL LIKELY BE COOL ON SATURDAY (GENERALLY IN THE 50S) IN A LIGHT NRLY FLOW BUT FARTHER INLAND OVER THE INTERIOR WEST HALF LOWER TO MID 60S CAN BE EXPECTED UNDER PREVALENT SUNSHINE. SAT NIGHT...MODELS SHOW THE NEXT SW FLOW SHORTWAVE RIPPLING THROUGH THE UPPER LAKES. WAA ASSOC WITH THIS SHORTWAVE WILL BRING ANOTHER ROUND OF SCT SHRA TO THE AREA. MODELS MORE UNCERTAIN ON EVOLVING PATTERN DETAILS FOR SUNDAY INTO NEXT WED AS A PACIFIC SHORTWAVE DIGS SE...DEEPENING MID-UPR LVL TROF OVER THE SW CONUS FOR EARLY NEXT WEEK. BOTH THE ECMWF AND GEM-NH SHOW A MORE AMPLIFIED MID-UPR LEVEL TROF DEVELOPING OVER THE ROCKIES/WRN PLAINS FOR EARLY NEXT WEEK ALLOWING FOR A SOUTHERLY FLOW OF GULF MOISTURE AHEAD OF THE ASSOC FRONTAL SYSTEM TO WORK ITS WAY NORTH INTO THE UPPER GREAT LAKES REGION. THE GFS ON THE OTHER HAND IS LESS AMPLIFIED AND MORE PROGRESSIVE WITH THIS FRONT MOVING IT THROUGH RATHER QUICKLY SUN NIGHT INTO EARLY MONDAY. DECIDED TO GO ALONG MORE WITH NCEP PREFERRED SLOWER/MORE AMPLIFIED ECMWF/GEM IDEA WHICH SHOULD YIELD MORE SHOWERS OVER THE UPPER GREAT LAKES...ESPECIALLY MONDAY INTO MONDAY NIGHT. ALSO INCLUDED A SLIGHT CHC FOR TSRA OVER MUCH OF THE CWA ON MON NIGHT AND FOR THE ERN PORTION OF CWA ON TUE AS ECMWF INDICATES NEG SHOWALTER INDICES IN WARM SECTOR AHEAD OF FRONTAL PASSAGE. MODELS SUGGEST DRIER AND COOLER CONDITIONS TUE NIGHT INTO WED IN THE WAKE OF THE COLD FRONT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 407 PM EDT WED MAY 7 2014 ALTHOUGH THERE WL BE PLENTY OF HI AND MID CLDS ARND INTO THIS EVNG...PERSISTENT DRY ESE FETCH WL MAINTAIN VFR WX AT ALL 3 TAF SITES THRU AT LEAST SUNSET. BUT THE ARRIVAL OF MORE SHRA AND POSSIBLY A TS BY LATE EVNG AS WELL AS AN APRCHG WARM FNT/LOWERING INVRN/INCRSGLY MOIST AIRMASS TAPPED BY THE SE FLOW...EXPECT MVFR CONDITIONS TO DVLP LATE TNGT AT SAW AND CMX...WHERE THIS FLOW WL UPSLOPE. DOWNSLOPE NATURE OF THE WIND AT IWD SHOULD MAINTAIN VFR CONDITIONS THERE. SOME MARGINAL LLWS MAY IMPACT ALL 3 SITES WITH THE STRENGTHENING/LOWERING FRONTAL INVRN...ESPECIALLY AT CMX WHERE THE LLVL WINDS ABV THE MORE STABLE NEAR SFC LYR WL BE STRONGER. MORE LLVL MOISTENING AHEAD OF APRCHG SFC WARM FNT WL CAUSE CIGS TO DROP INTO THE IFR RANGE AT CMX AND SAW AND TO MVFR AT IWD ON THU MRNG. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 407 PM EDT WED MAY 7 2014 EXPECT ENE WINDS UP TO 25 KTS TO VEER TO THE SE THRU THU AS LO PRES IN THE PLAINS APPROACHES THE AREA. THE STRONGEST WINDS ARE MOST LIKELY OVER THE W HALF OF LAKE SUPERIOR...WHERE THE TERRAIN WILL FUNNEL AND ENHANCE THE WINDS. SINCE THE LOW LEVEL AIR IS DRIER THAN EARLIER EXPECTED...TENDED TO SLOW DOWN THE ARRIVAL OF FOG AND CUT BACK ON THE COVERAGE. BUT AS MORE HUMID AIR MOVES IN LATER IN THE DAY AND THU NIGHT WITH A WIND SHIFT TO THE S AHEAD OF THE LO MOVING THRU MN...THE FOG SHOULD BECOME WIDESPREAD AND PERHAPS LOCALLY DENSE. THE LO WILL CONTINUE NE TOWARD JAMES BAY ON FRIDAY AND DRAG A TRAILING COLD FRONT ACROSS LAKE SUPERIOR DURING THE DAY...SHIFTING WINDS TO THE W. A HI PRES RIDGE WILL MOVE OVER THE LAKE ON FRI NIGHT AND REMAIN INTO SATURDAY...LEADING TO LIGHT WINDS. AS THE HI SHIFTS TO THE E AND ANOTHER DISTURBANCE APPROACHES FROM THE NW AND THEN PASSES ON MON...THE LLVL WINDS WILL VEER TO THE SSW AHEAD OF THE DISTURBANCE AND THEN THE TO NW FOLLOWING ITS PASSAGE EARLY MON. && .HYDROLOGY... ISSUED AT 449 PM EDT WED MAY 7 2014 WITH THE RECENT DRIER AND COOLER WEATHER...RIVER AND STREAM LEVELS HAVE SLOWLY COME DOWN OVER THE LAST 24 HOURS...ALTHOUGH THE STURGEON RIVER NEAR CHASSELL REMAINS CLOSE TO BANKFULL. WET WEATHER WILL RETURN TONIGHT INTO FRIDAY. MOST OF THE RAIN LOOKS TO FALL OVER THE STURGEON RIVER BASIN THURSDAY EVENING. ADDING TO THIS WILL BE A FEW INCHES OF SNOW WATER EQUIVALENT SHOWN FROM NOHRSC MODEL FROM THE TIP OF THE KEWEENAW PENINSULA THROUGH PAINESDALE...DONKEN...AND WINONA. THIS LINES UP WELL WITH THE LATEST SNOW DEPTHS REPORTED AT PAINESDALE AND HERMAN. WILL SEE HOW THIS SNOW MELT /WARMER FCST TEMPS FOR THE REST OF THE WEEK/ IMPACT DOWNSTREAM RIVERS INCLUDING THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES AND THE TRAP ROCK RIVER. MOST IF NOT ALL OF THE SNOW COULD MELT BY THIS WEEKEND. SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS WILL AFFECT THE AREA TONIGHT INTO EARLY FRIDAY. RAINFALL AMOUNTS WILL LIKELY EXCEED A HALF OF AN INCH FOR MOST OF UPPER MICHIGAN...AND LOCALIZED AMOUNTS OVER AN INCH SHOULD OCCUR WHERE THUNDERSTORMS TRACK. THIS WILL KEEP THE RIVER LEVELS HIGH INTO EARLY NEXT WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...VOSS AVIATION...KC MARINE...KC HYDROLOGY...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
408 PM EDT WED MAY 7 2014 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 407 PM EDT WED MAY 7 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW FAIRLY HI AMPLITUDE RDG BLDG FM THE SE CONUS INTO THE UPR LKS DOWNSTREAM OF A DEEP TROF IN THE ROCKIES. THERE ARE TWO CLOSED LOWS EMBEDDED IN THE TROF. ONE LO IS CENTERED OVER SASKATCHEWAN AND THE OVER THE DESERT SW. THE LO OVER THE DESERT SW WL HAVE THE MOST IMPACT ON UPR MI WX. WARM FNT TO THE E OF ASSOCIATED LO PRES IN THE CENTRAL PLAINS IS EXTENDING E THRU IOWA TOWARD THE LOWER LKS...WITH H85 FNT MOVING N INTO SRN MN/WI. A PAIR OF ELEVATED CONVECTIVE CLUSTERS THAT MOVED ENEWD WELL N OF THE WARM FNT IMPACTED MAINLY THE SCENTRAL COUNTIES THIS MRNG/EARLY AFTN...BUT LINGERING DRY AIR BEST DEPICTED ON THE 12Z APX RAOB AND HIER STABILITY THAT IS PRESENT FARTHER TO THE N PER LATEST SPC MESOANALYSIS LIMITED THE N PUSH OF THESE SHRA/TS INTO THE CWA. ABSENCE OF DYNAMIC FORCING OTHER THAN SOME GENERAL WAD/ ISENTROPIC ASCENT UNDER BLDG UPR RDG SO FAR TO THE NE OF MAIN FORCING MECHANISM CLOSER TO THE DESERT SW UPR LO IS RESULTING IN MAINLY DRY WX THIS AFTN...WITH MAINLY JUST THICKER HI CLDS IMPACTING AREAS AWAY FM THE SCENTRAL. MAIN FCST CONCERNS THRU THU INVOLVE POPS/ELEVATED TS CHCS AND INTENSITY TO THE N OF APRCHG SFC LO/ATTENDANT WARM FNT AS WELL AS POTENTIAL FOR FOG DVLPMNT. TNGT...UPR LO OVER THE DESERT SW IF FCST TO MOVE TO THE NE AND REACH THE WCENTRAL PLAINS BY 12Z THU. AS THE SFC LO SHIFTS SLOWLY TO THE NE AS WELL...ATTENDANT SFC WARM FNT IS FCST TO MOVE ONLY SLOWLY TO THE N INTO SCNTRL WI...BUT THE H85 FNT IS PROGGED TO LIFT MORE QUICKLY N THRU THE CWA. THE MOST APPRECIABLE DEEP LYR QVECTOR CNVGC/ UPR DVCG THAT IS NOW SUPPORTING MORE NMRS SHRA/SOME TS OVER THE NRN PLAINS INTO WRN MN IS FCST TO SWING INTO THE AREA FM THE W THIS EVNG AND IMPACT MAINLY THE NW PORTION OF THE CWA BEFORE EXITING TO THE NE LATER. AT LEAST SCT SHRA/SOME TS WL LIKELY SHIFT FARTHER TO THE ESE PARALLEL TO THE APRCHG H85 WARM FNT IN LINE WITH FCST CORFIDI VECTORS AND TOWARD STEEPER H7-5 LAPSE RATES. SINCE THE CONVECTION WL BE ELEVATED...PWAT WL BE APRCHG 200 PCT OF NORMAL AS WARMER/MOISTER AIR WITH H85 DEWPTS UP TO 12C FOLLOWING THE WARM FNT...AND FCST SDNGS IN THE MORE SATURATED AIRMASS SHOW THIN SKINNY CAPE...SUSPECT HEAVY RA WL BE THE MAIN THREAT. BUT SOME HAIL MAY FALL OVER THE STRONGER CELLS MAINLY NEAR THE SRN END OF THE SHRA AREA...WHERE FCST SDNGS SHOW STEEPER MID LVL LAPSE RATES /ALBEIT WITH A BIT MORE OF A CAP/ AND H85-3 WIND SHEAR IN THE ELEVATED UNSTABLE LYR IS AOA 40-50 KTS. THIS CAPPING WL BECOME MORE PRONOUNCED LATER FOLLOWING THE H85 WARM FROPA AND TEND TO DIMINISH POPS FM THE SW. AS THE LLVLS TO THE N OF INCRSGLY SHALLOW WARM FNT INVRN MOISTEN...EXPECT SOME FOG TO DVLP LATE...MAINLY WHERE THE EXPECTED ESE NEAR SFC FLOW UPSLOPES OFF LK MI. BUT TENDED TO CUT BACK ON THE FOG FCST TO ACCOUNT FOR STILL VERY DRY LLVLS. WITH INCRSG MSTR AND THE APRCH OF THE WARM FNT... EXPECT LTL DIURNAL TEMP FALL. THU...AS SHRTWV LIFTS TO THE NE AND INTO THE NRN PLAINS BY 00Z FRI...SFC LO IS FCST TO MOVE INTO SW MN BY 00Z FRI...WITH SFC WARM FNT TO THE E ARPCHG THE WI BORDER LATE. EXPECT PLENTY OF LO CLD TO THE N OF INCRSGLY SHALLOW WARM FNTL INVRN WITH SOME FOG AS WELL IN AREAS THAT EXPERIENCE UPSLOPE FLOW WITH THE LLVL SE WIND TO THE N OF THE FNT. BEST CHC FOR MORE NMRS SHRA/TS WL BE IN THE MRNG OVER THE NE HALF BEFORE CAPPING BEHIND H85 WARM FROPA/AREA OF DEEP LYR FORCING SHIFT TO THE NE AND GIVE WAY TO LARGER SCALE QVECTOR DVGC/ STRENGTHENING OF CAPPING INVRN. PREFER THE 12Z REGIONAL CNDN MODEL HANDLING OF THE POPS SHIFTED A BIT TO THE NE TOWARD THE LARGER SCALE FORCING AND AWAY FM LIKELY CAP. BEST CHC FOR SOME SUNSHINE WL BE OVER THE W IN THE AFTN WITH DOWNSLOPE SE WIND UNDER MID LVL CAPPING/ DRYING. HI TEMPS WL AT LEAST APRCH 70 IN THIS AREA. LINE OF SHRA/TS FED BY THIS HEATING AND CLOSER APRCH OF THE LO MAY MOVE INTO THE FAR W LATE IN THE DAY. THE CURRENT SPC OUTLOOK INDICATES FAR WRN UPR MI IS UNDER THE SLGT RISK FOR SVR STORMS. WITH SFC-6KM BULK SHEAR VALUES APRCHG 40-50KTS TOWARD 00Z IN THIS AREA AT THE TIME THE LINE OF CVNCTN MIGHT BE ARRIVING LATE IN THE DAY AHEAD OF THE SHARPER DEEP LYR QVECTOR CNVGC AND FCST MUCAPE AOA 1000J/KG...STRONGER STORMS WL BE PSBL IF SFC BASED PARCELS CAN BREAK THRU THE CAP. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 449 AM EDT WED MAY 7 2014 NAM SHOWS A 500 MB RIDGE OVER THE UPPER GREAT LAKES 12Z THU WITH A TROUGH OVER THE ROCKIES 12Z THU AND THIS TROUGH HEADS EAST INTO THE NORTHERN PLAINS ON THU AND INTO THE UPPER GREAT LAKES ON FRI. NAM BRINGS IN SOME ISENTROPIC LIFT AND MOISTURE ON I290K-I305K SURFACES ON THU WITH THE LIFT MOVING OUT OF THE AREA THU NIGHT. NAM ALSO BRINGS IN SOME 850-500 MB Q-VECTOR CONVERGENCE ON THU THAT LASTS INTO FRI MORNING BEFORE DEPARTING. GFS SHOWS ABOUT THE SAME THING. BASICALLY...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST. TRYING TO FIGURE OUT THE CONVECTION IS TOUGH AND BROADBRUSHED IT FOR THE MOST PART WITH SCATTERED TO NUMEROUS POPS IN FOR THU. THU NIGHT LOOKS TO BE THE BEST CHANCE FOR PCPN AS THE WARM FRONT MOVES THROUGH AND WENT CATEGORICAL OVER THE WEST. HAVE A DRY SLOT MOVING THROUGH ON FRIDAY WITH DIMINISHING POPS. DID NOT MAKE TOO MANY CHANGES TO THE TEMPERATURES OVERALL. STILL LOOKS LIKE FOG IS A GOOD BET ESPECIALLY THU NIGHT ACROSS THE AREA. IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE WESTERN U.S. WITH A TROUGH OVER THE UPPER GREAT LAKES 12Z SAT. THE TROUGH IN THE WESTERN U.S. DIGS INTO THE ROCKIES 12Z SUN WITH A SHORTWAVE MOVING INTO THE UPPER GREAT LAKES. THIS TROUGH DIGS FURTHER INTO THE ROCKIES 12Z MON AND INTO THE PLAINS 12Z TUE. WHAT THIS WILL MEAN FOR THE AREA IS THE WEATHER WILL REMAIN UNSETTLED THROUGH THE PERIOD WITH THE ONLY DRY PERIOD LOOKING LIKE IT WILL BE SATURDAY. OTHERWISE...THERE WILL BE SLIGHT CHANCE TO CHANCE POPS IN FOR THE REST OF THE PERIOD. TEMPERATURES WILL REMAIN BELOW NORMAL FOR THIS FORECAST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 407 PM EDT WED MAY 7 2014 ALTHOUGH THERE WL BE PLENTY OF HI AND MID CLDS ARND INTO THIS EVNG...PERSISTENT DRY ESE FETCH WL MAINTAIN VFR WX AT ALL 3 TAF SITES THRU AT LEAST SUNSET. BUT THE ARRIVAL OF MORE SHRA AND POSSIBLY A TS BY LATE EVNG AS WELL AS AN APRCHG WARM FNT/LOWERING INVRN/INCRSGLY MOIST AIRMASS TAPPED BY THE SE FLOW...EXPECT MVFR CONDITIONS TO DVLP LATE TNGT AT SAW AND CMX...WHERE THIS FLOW WL UPSLOPE. DOWNSLOPE NATURE OF THE WIND AT IWD SHOULD MAINTAIN VFR CONDITIONS THERE. SOME MARGINAL LLWS MAY IMPACT ALL 3 SITES WITH THE STRENGTHENING/LOWERING FRONTAL INVRN...ESPECIALLY AT CMX WHERE THE LLVL WINDS ABV THE MORE STABLE NEAR SFC LYR WL BE STRONGER. MORE LLVL MOISTENING AHEAD OF APRCHG SFC WARM FNT WL CAUSE CIGS TO DROP INTO THE IFR RANGE AT CMX AND SAW AND TO MVFR AT IWD ON THU MRNG. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 407 PM EDT WED MAY 7 2014 EXPECT ENE WINDS UP TO 25 KTS TO VEER TO THE SE THRU THU AS LO PRES IN THE PLAINS APPROACHES THE AREA. THE STRONGEST WINDS ARE MOST LIKELY OVER THE W HALF OF LAKE SUPERIOR...WHERE THE TERRAIN WILL FUNNEL AND ENHANCE THE WINDS. SINCE THE LOW LEVEL AIR IS DRIER THAN EARLIER EXPECTED...TENDED TO SLOW DOWN THE ARRIVAL OF FOG AND CUT BACK ON THE COVERAGE. BUT AS MORE HUMID AIR MOVES IN LATER IN THE DAY AND THU NIGHT WITH A WIND SHIFT TO THE S AHEAD OF THE LO MOVING THRU MN...THE FOG SHOULD BECOME WIDESPREAD AND PERHAPS LOCALLY DENSE. THE LO WILL CONTINUE NE TOWARD JAMES BAY ON FRIDAY AND DRAG A TRAILING COLD FRONT ACROSS LAKE SUPERIOR DURING THE DAY...SHIFTING WINDS TO THE W. A HI PRES RIDGE WILL MOVE OVER THE LAKE ON FRI NIGHT AND REMAIN INTO SATURDAY...LEADING TO LIGHT WINDS. AS THE HI SHIFTS TO THE E AND ANOTHER DISTURBANCE APPROACHES FROM THE NW AND THEN PASSES ON MON...THE LLVL WINDS WILL VEER TO THE SSW AHEAD OF THE DISTURBANCE AND THEN THE TO NW FOLLOWING ITS PASSAGE EARLY MON. && .HYDROLOGY... ISSUED AT 449 AM EDT WED MAY 7 2014 STREAMS AND RIVERS WILL CONTINUE TO EXPERIENCE HIGHER LEVELS. LOCATIONS STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER IN HOUGHTON AND BARAGA COUNTIES. WET WEATHER WILL RETURN TONIGHT THROUGH FRIDAY EVENING. MOST OF THE RAIN LOOKS TO FALL OVER THE STURGEON RIVER BASIN THURSDAY EVENING. ADDING TO THIS WILL BE THE FEW INCHES OF SNOW WATER EQUIVALENT BEING SHOWN FROM NOHRSC SET UP FROM THE TIP OF THE KEWEENAW PENINSULA THROUGH PAINESDALE...DONKEN...AND WINONA. THIS LINES UP WELL WITH THE LATEST SNOW DEPTHS REPORTED AT PAINESDALE AND HERMAN. WILL SEE HOW THIS SNOW MELT /GIVEN WARMER FCST TEMPS FOR THE REST OF THE WEEK/ IMPACTS DOWNSTREAM RIVERS INCLUDING THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES AND THE TRAP ROCK RIVER. MOST IF NOT ALL OF THE SNOW COULD MELT BY THIS WEEKEND. SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS WILL AFFECT THE AREA TONIGHT THROUGH FRIDAY NIGHT. RAINFALL AMOUNTS WILL LIKELY EXCEED A HALF OF AN INCH FOR MOST OF UPPER MICHIGAN...AND LOCALIZED AMOUNTS OVER AN INCH SHOULD OCCUR WHERE THUNDERSTORMS TRACK. THIS WILL KEEP THE RIVER LEVELS HIGH INTO EARLY NEXT WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...07 AVIATION...KC MARINE...KC HYDROLOGY...07
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
146 PM CDT WED MAY 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 434 AM CDT WED MAY 7 2014 SURFACE WARM FRONT THIS MORNING WAS JUST CROSSING THE BORDER FROM MO INTO IA AND IS ASSOCIATED WITH A 995 MB SFC LOW IN THE VICINITY OF CO/KS/NEB. THERE ARE A COUPLE OF BANDS OF STORMS OUT THERE THIS MORNING. ONE EXTENDS FROM CLEVELAND BACK TO GREEN BAY THAT YOU CAN FOLLOW BACK TO SHOWERS IN THE DULUTH AREA AND ASSOCIATED WITH THE ARRIVAL OF THE ELEVATED CAPE. AT THE NOSE OF THE LLJ AND EDGE OF THE CAPPING INVERSION /WHERE H7 TEMPS EXCEED +9C/ YOU WILL FIND A BROKEN LINE OF STORMS ALONG THE MN/IA. MPXWRF AND SPCWRF PRETTY MUCH NAILED THESE STORMS...SO FOLLOWED THE TREND OF THESE MODELS FOR WORKING HIGHER POPS SOUTH OF A MANKATO/RED WING/CHIP FALLS LINE THROUGH THE MORNING. GIVEN THE RAPS DEPICTION OF THE LLJ VEERING MORE EASTERLY THROUGH THE MORNING WITH LITTLE DEVELOPMENT NORTH...IT MAKES SENSE THAT THESE STORMS WILL NOT BUILD MUCH FARTHER NORTH OF THEIR CURRENT LATITUDE AND WILL INSTEAD HEAD MORE OR LESS DOWN I-90 INTO CENTRAL WI WITH THE LLJ. NOT EXPECTING MUCH SEVERE POTENTIAL OUT OF THESE...BUT WITH EFFECTIVE SHEAR UP NEAR 30 KTS AND CAPE BETWEEN -10C AND -30C /HAIL CAPE/ UP AROUND 500 J/KG...WE WILL LIKELY CONTINUE TO SEE THE OCCASIONAL STORM PUT OUT HAIL THAT GETS UP IN THE 1 INCH TERRITORY OR SLIGHTLY LARGER. BEHIND THIS MORNING ACTIVITY...H7 TEMPS WILL PUSH UP TO BETWEEN 8 AND 10C...WITH A VERY DRY PLUME OF AIR COMING IN IN THE H7-H5 LEVEL AS WELL. THIS WILL LIKELY KEEP THE MPX AREA CAPPED AND DRY MUCH OF THE DAY AS WE WATCH THE WARM FRONT LIFT NORTH ACROSS IOWA. BY PEAK HEATING...THIS WARM FRONT LOOKS TO BE UP NEAR I-90. WARM SECTOR COMING UP WITH THIS FRONT IS THE SAME AIRMASS THAT HAS SPENT THE LAST THREE DAYS BREAKING RECORD HIGHS ACROSS TX/OK/KS...SO IT WILL BE WARM TO SAY THE LEAST...WITH HIGHS IN THE 90S LIKELY CLEAR UP TO THE I-80 CORRIDOR. THIS WARM FRONT STILL MAKES FOR A DIFFICULT FORECAST AS OVERCAST CONDITIONS TO THE NORTH OF THE FRONT WILL HOLD HIGHS BACK IN THE 50S/60S...WHILE SOUTH OF THE BOUNDARY IT WILL BE FEELING LIKE SUMMER. CONTINUED TO FAVOR THIS FORECAST TOWARD THE ECMWF...WHICH HAS MID 80S ALONG I-90 THAT FALL BACK TO THE UPPER 50S/LOWER 60S NORTH OF I-94. WE WILL HAVE TO WATCH THOSE TEMPS THOUGH. THERE IS VIRTUALLY NO CLOUD COVER ACROSS IOWA RIGHT NOW...AND IF THIS TREND CONTINUES OVER US THIS AFTERNOON...THEN SOMETHING MUCH CLOSER TO WHAT THE RAP HAS BEEN SHOWING ALL MORNING IS POSSIBLE...WHICH IS LOWER 90S COMING UP AS FAR NORTH AS MANKATO/REDWOOD FALLS...WITH HIGHS CLOSER TO 80 IN THE CITIES...WITH EVEN THE COLDER AREAS AROUND LADYSMITH PUSHING 70. MAIN QUESTION FOR THIS EVENING/TONIGHT IS WHEN DOES THE CAP BREAK. ONCE IT DOES...IT IS LOOKING LIKE A VERY ACTIVE NIGHT ACROSS THE MPX CWA. THROUGH THE AFTERNOON...ANY ACTIVITY LOOKS TO REMAIN TO THE NW OF THE CAP...WHICH WOULD KEEP THE BULK OF THE ACTIVITY TODAY OUT FROM CENTRAL SODAK INTO NW MN. EVENTUALLY...A STRENGTHENING LLJ AND THE APPROACH OF THE MAIN UPPER TROUGH WILL START TO ERODE THE CAP. GENERALLY FOLLOWED THE IDEA OF THE SPCWRF AND THE NMM/ARW WITH ACTIVITY TAKING OFF BETWEEN 2Z AND 4Z. GIVEN THE DEGREE OF INSTABILITY EXPECTED AND EFFECTIVE SHEARS UP AROUND 50 KTS...IT IS VERY LIKELY THAT THESE STORMS WILL BE ABLE TO PRODUCE LARGE HAIL...SO THE DAY1 SLIGHT RISK IS MORE THAN WARRANTED. ALTHOUGH NO CONVECTION IS CURRENTLY ANTICIPATED IN THE AFTERNOON...IF WE WERE TO SEE SOMETHING GO IT WOULD HAVE A HIGH LIKELIHOOD OF BEING SEVERE...WITH A TORNADO THREAT IF IT IS CLOSE TO THE WARM FRONT. HOWEVER...THE WARM/DRY LAYER NOTED EARLIER AROUND H7 WILL MOST LIKELY KEEP ANYTHING FROM GOING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 434 AM CDT WED MAY 7 2014 THE EXTENDED PERIOD WILL BE AN ACTIVE ONE WITH ONLY ONE DRY PERIOD FORECAST AND THAT IS FRIDAY NIGHT. THURSDAY IS THE DAY OF INTEREST. ALL INDICATIONS ARE FOR LOW PRESSURE OVER EASTERN NEBRASKA THURSDAY MORNING TO SLOWLY DEEPEN WHILE MOVING INTO SOUTHWEST MINNESOTA DURING THE AFTERNOON AND INTO CENTRAL MINNESOTA DURING THE EVENING. CONVECTION IS ANTICIPATED TO BE ONGOING THURSDAY MORNING ACROSS CENTRAL MN AND WEST CENTRAL WI. THIS WILL MOVE NORTHEAST EARLY ON ALLOWING FOR THE DESTABILIZATION TO COMMENCE. PROJECTIONS FOR THE AFTERNOON AND EVENING HOURS ARE FOR 0-1KM SHEAR TO BE IN THE 25-35 KNOT RANGE AHEAD OF THE LOW AND COLD FRONT WITH 0-6KM SHEAR IN THE 40-50 KNOT RANGE. EASTERN MN AND WESTERN WI ARE ALSO IN A FAVORABLE COUPLED JET ALOFT WITH 100 KNOT RIGHT ENTRANCE REGION OVER NORTHERN MN WHILE A 100+ KNOT JET SURGES INTO EASTERN IA DURING THE AFTERNOON. THE DIFFERENTIAL DIVERGENCE IS QUITE STRONG BY EVENING ACROSS THE TWIN CITIES. ALSO...VARIOUS SOLUTIONS ARE POINTING TO 0-3KM CAPE REACHING 100-150 J/KG BY LATE IN THE AFTERNOON...AGAIN CLOSE TO THE TWIN CITIES. HENCE...A SEVERE AFTERNOON AND EVENING IS LOOKING MORE AND MORE LIKELY WITH ALL FORMS OF SEVERE WEATHER POSSIBLE INCLUDING A FEW TORNADOES. THE SEVERE THREAT SHOULD BE OVER BY MIDNIGHT ACROSS WESTERN WI AS THE ATTENDANT COLD FRONT MOVES THROUGH. HIGHS ON THURSDAY HAVE POTENTIAL TO RUN INTO THE 80S FROM THE TWIN CITIES ON SOUTH AND SOUTHWEST. BLENDED GUIDANCE KEPT HIGHS IN THE UPPER 70S. A FEW SHOWERS MAY LINGER OVER NORTHERN AND EASTERN AREAS OF THE FA ON FRIDAY UNDER THE COLD UPPER TROUGH. AS MENTIONED EARLIER...FRIDAY NIGHT IS THE ONLY DRY PERIOD AS A WEAK RIDGE OF HIGH PRESSURE MOVES THROUGH. THE PATTERN STARTS TO BECOME MORE ACTIVE AGAIN ON SATURDAY AS NORTHERN AND SOUTHERN STREAM ENERGY BEGIN TO INFLUENCE THE WESTERN HALF OF THE CONUS. THIS DEVELOPS ANOTHER WAVE OF LOW PRESSURE TO OUR SOUTHWEST WITH SHOWER CHANCES INCREASING THROUGH THE WEEKEND AND EARLY NEXT WEEK. SOME SIGNIFICANT DIFFERENCES EXIST BETWEEN THE GFS AND EC BY EARLY NEXT WEEK ON THE LOCATION OF THE SURFACE LOW. THE GFS WOULD BE FLATTER AND FURTHER EAST WITH THE LOW WHILE THE EC IS MORE ROBUST WITH THE UPPER TROUGH AND SURFACE LOW. THIS WILL NEED TO BE WATCHED AS WE COULD BE CLOSE TO THE WARM SECTOR ALONG WITH A SEVERE WEATHER THREAT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1257 PM CDT WED MAY 7 2014 AT LEAST A COUPLE ROUNDS OF THUNDERSTORMS ARE EXPECTED OVER THE NEXT 24 HOURS. THE FIRST ROUND ARRIVES THIS EVENING AND SHOULD MAINLY AFFECT EASTERN MN AND WESTERN WI BETWEEN 01Z-06Z. THE MAIN THREAT WITH THE STORMS TONIGHT WILL BE LARGE. THE SECOND ROUND OF STORMS IS EXPECTED LATE IN THE MORING IN WESTERN MN AND DURING THE AFTERNOON IN EASTERN MN AND WESTERN WI. MVFR CEILINGS HAVE BEEN SLOW TO ADVANCE NORTH TODAY...AND IT ACTUALLY LOOKS LIKE THAT MOST OF THE 2000-3000FT CEILINGS WILL STAY IN FAR WESTERN MN. KMSP... NO AVIATION WEATHER CONCERNS FOR THE REMAINDER OF THE DAYLIGHT HOURS /INCLUDING THE EVENING PUSH/. WE EXPECTED THUNDERSTORMS IN EASTERN MN LATE THIS EVENING...BUT MOST OF THE ACTIVITY WILL OCCUR BETWEEN 02-04Z...WITH THE PRIMARY THREAT BEING LARGE HAIL. WE ARE MUCH LESS CONFIDENT IN HOW MUCH ACTIVITY WILL PERSIST OVERNIGHT AND INTO THE THURSDAY MORNING COMMUTE. MOST OF THE ACTIVITY SHOULD FOCUS ITSELF NORTH OF THE AIRPORT. THE SECOND ROUND HAS A BETTER CHANCE AT PRODUCING SEVERE WEATHER TOMORROW AFTERNOON. /OUTLOOK FOR KMSP/ THU NIGHT...MVFR CONDITIONS POSSIBLE WITH SHOWERS AND THUNDERSTORMS. WINDS S BECOMING W AT 10G20KTS. FRI...MVFR EARLY...THEN VFR. WINDS W AT 10G20KTS. SAT...VFR. WINDS S 5-10KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...RAH AVIATION...CLF
AREA FORECAST DISCUSSION
NWS BILLINGS MT
324 PM MDT WED MAY 7 2014 .SHORT TERM...VALID FOR THU AND FRI... AREAS OF RAIN/SNOW CONTINUE THIS AFTERNOON AS WE CONTINUE TO BE AFFECTED BY SLOW MOVING TROF OVER THE NORTHERN/CENTRAL ROCKIES AND DEEP UPSLOPE FLOW...THOUGH WITH DIMINISHED PCPN RATES. MID AND UPPER LEVEL DRY SLOTTING IS IMPACTING OUR SOUTH CENTRAL AND SOUTHEAST PARTS...SO HAVE DROPPED THE ADVISORY FOR THE BIG HORNS. COLDER TOPS CONTINUE FOR OUR WEST...AND SOME CONVECTION IN WESTERN WY MAY FEED INTO THE MTNS OVER THE NEXT FEW HOURS...SO WILL LET THE WARNING FOR THE BEARTOOTH ABSAROKAS RIDE INTO THE EVENING. COLE CREEK SNOTEL IN THE MTNS ABOVE RED LODGE HAS ALREADY PICKED UP AT LEAST A FOOT OF SNOW SINCE YESTERDAY. OTHERWISE...ONLY LIGHT PCPN EXPECTED INTO THIS EVENING WITH A GRADUAL TAPERING OFF TONIGHT AS BEGIN TO PULL IN DRIER AIR FROM THE NW. SFC RIDGING IN EASTERN MT SUPPORTS LIGHT WINDS TONIGHT...WHICH ALONG WITH THE ABUNDANT LOW LEVEL MOISTURE IN PLACE SHOULD RESULT IN SOME FOG TONIGHT ESPECIALLY WITH A LITTLE CLEARING FROM THE NW LATER ON. 12Z GUIDANCE NOT SHOWING MUCH BUT RECENT RAP RUNS SEEM TO BE TRENDING TOWARD BETTER FOG POTENTIAL AFTER MIDNIGHT. HAVE ADDED FOG TO THE FORECAST FROM 06-15Z. OTHER IMPACT TONIGHT WILL BE FREEZING TEMPS FOR MUCH OF THE REGION...SO TAKE PRECAUTIONS IF YOU HAVE SENSITIVE PLANTS OUTDOORS. QUIET DAY IN STORE TOMORROW AS HEIGHTS BUILD FROM THE WEST AND WE BEGIN TO WARM UP. ENERGY COMING OUT OF THE CENTRAL ROCKIES WILL ALMOST ENTIRELY MISS OUR CWA TO THE SE...SO A DRY FORECAST LOOKS GOOD FOR TOMORROW AFTER SOME EARLY MORNING FOG OR LIGHT RAIN/SNOW SHOWERS. HIGHS THURSDAY WILL REACH THE 50S TO LOW 60S...WARMEST WEST. NEXT PACIFIC SHORTWAVE WILL PUSH INTO THE NORTHERN ROCKIES FRIDAY...GIVING US A GOOD CHANCE OF SHOWERS AND A FEW THUNDERSTORMS. LATEST MODEL TRENDS ARE A BIT FASTER WITH THIS ENERGY SO COULD SEE SHOWERS IN OUR WEST BY MORNING...SO NOT QUITE AS GOOD A CONVECTIVE OPPORTUNITY AS A RESULT FOR OUR WEST. NONETHELESS WITH GOOD QG FORCING HAVE RAISED POPS FRI AND FRI NITE. MID LEVEL TEMPS WILL COOL ENOUGH TO TURN PCPN BACK TO SNOW FOR OUR MTNS BY FRI EVENING...WITH A BIT OF ACCUMULATION FOR THE MTNS FRI NITE. SHOULD ALSO SEE SOME GUSTY W-NW WINDS FRI AFTN AND EVENING PER THE FRONTAL PASSAGE AND SHOWER ACTIVITY. HIGH TEMPS ON FRI WILL REACH THE 60S...AND PERHAPS NEAR 70 IN OUR EAST W/ LATER FROPA. JKL .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... MODELS ARE COMING INTO BETTER AGREEMENT IN THE EXTENDED PERIOD. THIS COMING WEEKEND WILL BE SOMEWHAT WET...AFTER A WARMER FRIDAY...AS A SHORTWAVE MAKES ITS WAY THROUGH SOUTHERN MONTANA. SNOW LEVELS WILL REMAIN AROUND 6000 FT ACROSS THE REGION...SO MOST OF THE PRECIP SHOULD BE IN THE FORM OF RAIN AT LOWER ELEVATIONS. AT HIGHER ELEVATIONS...ADDITIONAL SNOW ACCUMULATION IS POSSIBLE. INTO NEXT WEEK...THE REGION WILL BE UNDER THE INFLUENCE OF NORTHWESTERLY FLOW ALOFT ON THE EASTERN SIDE OF A RIDGE. SEVERAL SHORTWAVES WILL ATTEMPT TO RIDE THIS RIDGE INTO SOUTH CENTRAL MONTANA. THEREFORE...HAVE KEPT POP VALUES AROUND CLIMO UNTIL CERTAINTY BECOMES CLEARER. TEMPS WILL REMAIN FAIRLY MILD WELL INTO NEXT WEEK WITH NO SIGNIFICANT WARMUP IN SIGHT. THE COOLER TEMPERATURES WILL STUNT THE MELTING OF HIGHER ELEVATION SNOWPACK ANOTHER WEEK. SINGER && .AVIATION... STILL SOME LINGERING RAIN AND SNOW SHOWERS IN AND AROUND KBIL...KMLS...AND KSHR THIS AFTERNOON AS THE STORM SYSTEM WORKS ITS WAY EASTWARD. MOST OF THIS ACTIVITY SHOULD WIND DOWN BY THE EARLY EVENING HOURS. THE POTENTIAL FOR FOG WILL PRESENT ITSELF...ESPECIALLY AT KBIL...DURING THE OVERNIGHT HOURS CAUSING POTENTIAL VISIBILITY ISSUES. SINGER && .PRELIMINARY POINT TEMP/POPS... THU FRI SAT SUN MON TUE WED ----------------------------------------------------------- BIL 030/057 040/065 043/058 038/057 040/062 042/065 043/062 51/B 04/T 55/W 43/W 33/W 22/W 44/W LVM 025/061 037/061 036/055 035/056 035/059 038/064 039/064 51/U 16/T 55/W 43/W 33/W 32/W 22/W HDN 032/057 033/068 039/060 034/060 037/064 039/067 040/064 51/B 03/T 64/W 53/W 33/W 22/W 44/W MLS 033/057 035/069 043/059 037/058 038/062 041/064 042/060 31/B 02/T 55/W 52/W 23/W 23/W 44/W 4BQ 032/054 034/068 041/059 035/058 036/061 039/064 040/060 52/W 01/B 54/W 32/W 23/W 22/W 33/W BHK 033/054 032/067 041/059 035/056 036/058 038/060 039/057 31/B 01/U 55/W 42/W 22/W 23/W 33/W SHR 031/054 031/065 038/056 032/055 034/059 036/063 037/062 52/W 02/T 54/W 44/W 34/W 33/W 33/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...WINTER STORM WARNING IN EFFECT UNTIL MIDNIGHT MDT TONIGHT FOR ZONE 67. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
357 PM CDT WED MAY 7 2014 .SHORT TERM...(TONIGHT THROUGH SATURDAY) ISSUED AT 352 PM CDT WED MAY 7 2014 CHANCES FOR THUNDERSTORMS TONIGHT AND THURSDAY ARE THE PRIMARY FORECAST CONCERNS. EARLY AFTERNOON SURFACE ANALYSIS SHOWED A FRONTAL BOUNDARY EXTENDING FROM LOW PRESSURE IN SOUTHEAST SOUTH DAKOTA SOUTHWEST THROUGH NORTHEAST NEBRASKA. NORTHEAST WINDS NORTHWEST OF THE FRONT WERE KEEPING TEMPERATURES IN THE 70S THERE...WHILE GUSTY SOUTH WINDS SOUTHEAST OF THE FRONT HAD PUSHED TEMPS WELL INTO THE 80S WITH SOME 90S ALSO SEEN/EXPECTED. IN OUR SOUTHWEST CWA...DEEPER MIXING WAS OCCURRING...WITH WINDS BECOMING SOUTHWESTERLY WHICH WERE DRYING LOW LEVELS AND BOOSTING TEMPERATURES. RELATIVE HUMIDITIES CLOSE TO 15 PERCENT WERE NOSING INTO JEFFERSON/SALINE COUNTIES AS OF 2 PM...AND WILL LIKELY SPREAD EAST ACROSS RED FLAG WARNING AREA THROUGH THE AFTERNOON. SO WILL KEEP THAT GOING INTO THE EVENING. A COUPLE OF AREAS OF POTENTIAL CONVECTION WERE OF NOTE AT EARLY AFTERNOON. ONE EXTENDING FROM NORTH CENTRAL NEBRASKA INTO SOUTH DAKOTA...AND THE OTHER ACROSS CENTRAL KANSAS. CONGESTUS-LOOKING CLOUDS WERE TRYING TO IGNITE IN NORTH CENTRAL NEBRASKA...AND CLOUD TOP COOLING ALGORITHMS WERE SUGGESTING A SMALL CHANCE FOR THOSE CLOUDS TO CONVECT. BUT IF THEY DO...THEY WILL MOST LIKELY RIDE NORTH- NORTHEAST INTO SOUTH DAKOTA. SIGNIFICANT CONVECTIVE INHIBITION WAS NOTED OVER THIS AREA...SO THERE IS A MUCH BETTER CHANCE NOTHING WILL GO CLOSE TO OUR AREA...FOCUSING ACTIVITY MORE IN WESTERN NEBRASKA AND THE FOOTHILLS WHERE INHIBITION IS LOW. KANSAS POTENTIAL CONVECTION WAS BUBBLING UP UNDER INCREASING MID LEVEL WIND FIELD AHEAD OF TROUGH APPROACHING THE SOUTHERN ROCKIES...AND WHERE SURFACE TEMPERATURES WERE WELL INTO THE 90S. DRYLINE WAS IN THIS AREA AS WELL...ADDING LOW LEVEL CONVERGENCE INTO THE MIX. ALSO OF NOTE...MESOSCALE MODELS RAP AND HRRR ALONG WITH NAM12 EVENTUALLY BUBBLE CONVECTION NORTH AND NORTHEAST OF THIS AREA LATER THIS EVENING...AND MOVE THAT INTO EASTERN NEBRASKA AND SOUTHWEST IOWA WHERE INTERACTION WITH SURFACE FRONT WILL ENHANCE POTENTIAL. CINH IS LOWERING DRAMATICALLY ACROSS SOUTHEAST NEBRASKA WHERE DEW POINTS HAD ONLY MIXED INTO THE 50S...WITH OVER 2000 J/KG MUCAPE AVAILABLE. SO GIVEN INSTABILITY...FRONT IN THE AREA...AND A PREPONDERANCE OF MODEL DATA FIRING CONVECTION...WILL ADD AT LEAST SMALL POPS TO MOST OF OUR AREA THIS EVENING AND OVERNIGHT. SOME STORMS COULD APPROACH SEVERE...WITH AT LEAST SMALL HAIL AND GUSTY WINDS POSSIBLE. THEN LATER TONIGHT...STORMS FIRING IN THE NEBRASKA PANHANDLE REGION IS FORECAST TO SLOWLY SHIFT EAST-NORTHEAST OVERNIGHT...AND COULD REACH PARTS OF NORTHEAST NEBRASKA BEFORE MORNING. OTHERWISE EXPECT ANY MORNING STORMS TO GRADUALLY WORK EAST AND NORTHEAST OF OUR AREA BY MID MORNING BEFORE NEXT POTENTIAL ROUND SETS UP IN THE AFTERNOON. UPPER TROUGH/LOW IS EXPECTED TO EJECT NORTHEAST INTO THE PLAINS ON THURSDAY...REACHING THE DAKOTAS BY LATE AFTERNOON. MEANWHILE TRAILING SURFACE COLD FRONT WILL BE MARCHING EAST INTO EASTERN NEBRASKA IN THE AFTERNOON. VARYING MODEL TIMING OF THIS FEATURE IS STILL APPARENT...BUT WERE BETTER IN LINE SHOWING BEST CONVECTIVE CHANCES NEAR AND EAST OF THE MISSOURI RIVER AT TIME OF MAX HEATING AND INSTABILITY. EXPECT STORMS TO FIRE ALONG COLD FRONT FROM WEST CENTRAL IOWA INTO SOUTHEAST NEBRASKA BY MID/LATE AFTERNOON WHERE SURFACE-BASED CAPES WILL EXCEED 2000 J/KG AND CLOSE TO 50KT OF 0-6KM BULK SHEAR WILL RESIDE. HAIL AND DAMAGING WINDS WILL CERTAINLY BE POSSIBLE WHERE STORMS DO FIRE. STORMS WILL RACE NORTHEAST AS FRONT PUSHES EAST...SO EXPECT MOST CONVECTION TO BE WELL EAST OF OUR AREA BY MID EVENING. SOME LINGERING STORMS WILL BE POSSIBLE IN FAR SOUTHEAST NEBRASKA AND SOUTHWEST IOWA WHERE FRONT WILL BE SLOWER TO CLEAR THOSE AREAS. SOME WRAP-AROUND SHOWERS ARE ALSO POSSIBLE IN NORTHEAST NEBRASKA THURSDAY EVENING. FRIDAY LOOKS DRY AND COOLER BEHIND EXITING FRONT...WITH HIGHS FROM THE UPPER 60S TO LOWER 70S. A QUICK RETURN TO SOUTHERLY LOW LEVEL FLOW DEVELOPS FRIDAY NIGHT AS A TRAILING UPPER WAVE INDUCES SURFACE LOW PRESSURE IN THE HIGH PLAINS. AS WAVE TRACKS EAST ON SATURDAY...SURFACE FRONT WILL ENTER NORTHEAST NEBRASKA IN THE MORNING...THEN INTO NORTHERN KANSAS AND MISSOURI SATURDAY EVENING. SHOWERS AND SOME THUNDERSTORMS WILL BE POSSIBLE WITH THIS FRONT THROUGH THE DAY SATURDAY...WITH TEMPERATURES REMAINING GENERALLY IN THE 70S. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 352 PM CDT WED MAY 7 2014 A STRONGER MID LEVEL TROUGH IS FORECAST TO SETTLE INTO THE ROCKIES BY SUNDAY...THEN PROGRESS INTO THE PLAINS MONDAY AND TUESDAY OF NEXT WEEK. TIMING DIFFERENCES ABOUND BETWEEN GFS/ECMWF AND THEIR ENSEMBLE MEMBERS...BUT ALL POINT TO AN UNSETTLED WEATHER PATTERN AND CHANCES FOR PRECIPITATION AT LEAST INTO MONDAY NIGHT. EXPECT MORE OF AN OVERRUNNING-TYPE SCENARIO FOR OUR AREA AS FRONTAL BOUNDARY REMAIN TO OUR SOUTH FOCUSING CONVECTION ACROSS KANSAS AND MISSOURI. ECMWF HAS TRENDED TOWARD GFS SOLUTION IN THIS REGARD. SO HAVE AT LEAST CHANCE POPS FOR RAIN/SHOWERS ACROSS A GOOD PART OF THE AREA SATURDAY NIGHT INTO MONDAY NIGHT. BEYOND MONDAY NIGHT...EXPECT NORTHWEST FLOW ALOFT TO RULE INTO WEDNESDAY. A SHORTWAVE OR TWO COULD BRING ISOLATED PRECIP CHANCES DURING THIS TIME...BUT MAIN STORY WILL BE COOLER TEMPERATURES WITH HIGHS GENERALLY IN THE 60S. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 116 PM CDT WED MAY 7 2014 SURFACE LOW WAS LOCATED OVER EAST CENTRAL NEBRASKA AT 18Z WITH WARM FRONT BEGINNING TO PIVOT NORTHWEST INTO NORTHEAST NEBRASKA. THIS BOUNDARY IS EXPECTED TO REMAIN ACROSS THE AREA THROUGH THURSDAY MORNING AS A SECONDARY SURFACE WAVE LIFTS NORTHEAST OUT OF COLORADO TOWARDS SOUTHWEST MINNESOTA THURSDAY AFTERNOON. VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT BOTH KLNK AND KOMA AS THEY REMAIN IN THE WARM SECTOR...WHILE MORE VARIABLE CONDITIONS LIKELY AT KOFK WITH A PERIOD OF MVFR CIGS AND VSBY 03Z-12Z AS SHOWERS AND THUNDERSTORMS DEVELOP ON THE NORTH SIDE OF THE FRONTAL BOUNDARY. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR NEZ050-051- 065>068-078-088>090. IA...NONE. && $$ SHORT TERM...DERGAN LONG TERM...DERGAN AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS HASTINGS NE
353 PM CDT WED MAY 7 2014 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 333 PM CDT WED MAY 7 2014 MAP ANALYSIS INDICATES AN UPPER TROPOSPHERIC LONGWAVE TROUGH AXIS NEARING THE ROCKY MOUNTAIN RANGE...AND A RIDGE OVER THE EASTERN CONUS. A CLOSED UPPER TROPOSPHERIC LOW IS ALSO NOTED EMBEDDED WITHIN THE LONGWAVE TROUGH AXIS. ENHANCED UPPER TROPOSPHERIC JET ENERGY EXTENDS SOUTH ALONG THE WESTERN CONUS COAST. THIS ENHANCED FLOW THEN SPLITS INTO TWO BRANCHES...WITH ONE BRANCH EXTENDING EAST ACROSS THE SOUTHERN CONUS...AND ANOTHER EXTENDING NORTHEAST INTO THE PLAINS AND THEN EAST/SOUTHEAST OVER THE GREAT LAKES REGION AND INTO THE NORTHEASTERN CONUS. UPPER TROPOSPHERIC FLOW OVER OUR AREA MAXES OUT AT AROUND 55KTS NEAR 36000FT AGL PER 12Z SOUNDING DATA FROM KLBF AND KOAX. WATER VAPOR IMAGERY SHOWS THE AFOREMENTIONED LONGWAVE TROUGH AXIS AND RIDGE AXIS. WATER VAPOR IMAGERY ALSO SHOWS INCREASED UPPER TROPOSPHERIC MOISTURE EXTENDING FROM THE FOUR CORNERS REGION INTO THE CENTRAL HIGH PLAINS...AS WELL AS FROM SOUTHERN TEXAS INTO THE MID-MISSISSIPPI VALLEY. AN UPPER TROPOSPHERIC DRY INTRUSION IS NOTED MOVING FROM WEST-TEXAS INTO THE SOUTHERN AND CENTRAL PLAINS. AT THE SURFACE AN AREA OF LOW BAROMETRIC PRESSURE IS NOTED OVER WESTERN KANSAS AND EASTERN COLORADO...WITH A WARM FRONT EXTENDING FROM THE LOW NORTHEASTWARD INTO CENTRAL AND EAST-CENTRAL NEBRASKA. ANOTHER AREA OF LOW BAROMETRIC PRESSURE IS NOTED STRENGTHENING ALONG THE LOWER TROPOSPHERIC BAROCLINIC ZONE OVER EAST-CENTRAL NEBRASKA. A DRY LINE IS NOTED EXTENDING SOUTH/SOUTHWEST FROM THIS SECONDARY LOW AND AS OF 20Z WAS NOTED FROM NEAR KBIE...TO NEAR KCNK...TO NEAR KGBD. THE RESULTANT LOWER TROPOSPHERIC WIND FIELD ACROSS OUR AREA REMAINS FROM THE NORTH/NORTHEAST ACROSS OUR NORTH/NORTHWESTERN CWA...WHILE LOCATIONS FARTHER SOUTH/SOUTHEAST...SOUTH OF THE WARM FRONT AND BEHIND THE DRY LINE...HAS TURNED MORE SOUTHWESTERLY. GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL SUGGEST THE WESTERN CONUS UPPER TROPOSPHERIC LONGWAVE TROUGH WILL MOVE EAST...WITH THE EMBEDDED CLOSED LOW WEAKENING INTO AN OPEN WAVE AND MOVING EAST/NORTHEAST...AS A NEGATIVELY-TILTED SHORT WAVE...FROM THE CENTRAL HIGH PLAINS INTO PORTIONS OF THE NORTHERN PLAINS THROUGH THE NEXT 24 HOURS. THE AREA OF LOW BAROMETRIC PRESSURE AT THE SURFACE OVER WESTERN KANSAS IS EXPECTED TO MOVE NORTHEAST INTO CENTRAL NEBRASKA BY 12Z THURSDAY...AND INTO SOUTHWESTERN MINNESOTA BY 00Z FRIDAY. AS THE SURFACE LOW MOVES INTO CENTRAL NEBRASKA...THE LOWER TROPOSPHERIC WIND FIELD ACROSS OUR AREA SHOULD BECOME MORE SOUTH/SOUTHWESTERLY TONIGHT...BEFORE BECOMING MORE NORTHWESTERLY DURING THE DAY THURSDAY AS AN ASSOCIATED LOWER TROPOSPHERIC BAROCLINIC ZONE CLEARS THE AREA. THE AFOREMENTIONED UPPER TROPOSPHERIC SHORT WAVE IS EXPECTED TO REMAIN WEST/NORTHWEST OF OUR AREA TONIGHT INTO TOMORROW...THUS KEEPING THE VAST MAJORITY OF RESULTANT OMEGA TO OUR NORTHWEST AS WELL. AS A RESULT...PRECIPITATION PRODUCTION IS ALSO EXPECTED TO REMAIN NORTHWEST OF OUR AREA THIS AFTERNOON INTO THIS EVENING...A SOLUTION SUPPORTED BY QPF FIELDS FROM THE NAM...OPERATIONAL GFS...EC...SREF-MEAN...AS WELL AS SIMULATED REFLECTIVITY FROM THE HRRR...1KM WRF-ARW...1KM WRF-NMM AND 4KM WRF-NMM. THAT BEING SAID...THERE ARE INDICATIONS FROM SOME SIMULATED REFLECTIVITY OUTPUT THAT SOME OF THE HIGH PLAINS CONVECTION COULD BRUSH OUR FAR WESTERN CWA BETWEEN 23Z AND 02Z. ALTHOUGH THE EVENING SHIFT WILL WANT TO MONITOR HIGH PLAINS CONVECTION IN CASE IT TRIES TO MAKE A PUSH EAST INTO OUR WESTERN CWA...FOR NOW WILL MAINTAIN A DRY FORECAST THROUGH THIS EVENING. IT ALSO WORTH MENTIONING THAT VARIOUS SETS OF GUIDANCE SUGGEST CONVECTION COULD BE REALIZED THIS AFTERNOON INTO EARLY THIS EVENING ALONG THE DRY LINE ADVANCING ACROSS THE REGION...BUT SINCE THIS DRY LINE HAS ALREADY CLEARED OUR AREA ANY RESULTANT CONVECTION SHOULD REMAIN SOUTH/SOUTHEAST OF OUR AREA...MORE INTO KANSAS AND SOUTHEASTERN NEBRASKA. OVERNIGHT TONIGHT...GUIDANCE SUGGESTS A ~60KT JET AXIS JUST ABOVE THE BOUNDARY LAYER WILL DEVELOP FROM CENTRAL KANSAS INTO PORTIONS SOUTH CENTRAL NEBRASKA. THERMAL ADVECTION ALONG THIS AXIS AND MOISTURE CONVERGENCE NEAR THE NOSE OF THIS JET APPEAR AS THOUGH THEY WILL BE SUFFICIENT FOR PRECIPITATION PRODUCTION ACROSS MUCH OF THE CWA...A SOLUTION SUPPORTED BY THE NAM...OPERATIONAL GFS ...SREF-MEAN...AS WELL AS SIMULATED REFLECTIVITY FROM THE HRRR AND 1KM WRF-ARW. COVERAGE APPEARS AS THOUGH IT WILL BE SPOTTY AT BEST AND THUS DID NOT WANT TO GO MUCH HIGHER THAN A 20% POP FOR MUCH OF THE CWA...AND SUCH HAS BEEN PRESENTED IN THE OFFICIAL FORECAST FOR THE MOST PART. THE LOWER TROPOSPHERIC JET AXIS SHOULD WEAKEN TOWARDS DAYBREAK THURSDAY AS IT MOVES OFF TO THE EAST...THUS ALLOWING FOR DECREASING POPS ACROSS OUR AREA THURSDAY MORNING. THAT BEING SAID...THERMAL ADVECTION AHEAD OF THE WESTERN CONUS LONGWAVE TROUGH AXIS MAY MOVE JUST FAR ENOUGH EAST TO IMPACT EXTREME WEST/NORTHWEST PORTIONS OF OUR CWA AND AS A RESULT...WENT AHEAD WITH A ~20% POP ACROSS OUR WEST/NORTHWEST DURING THE DAY THURSDAY. LOCATIONS ACROSS OUR EXTREME EAST COULD ALSO OBSERVE ISOLATED CONVECTIVE ACTIVITY BY DURING THE AFTERNOON AS THE AFOREMENTIONED LOWER TROPOSPHERIC BAROCLINIC ZONE CLEARS THE AREA BEHIND THE SURFACE LOW. AS A RESULT...ALSO WENT AHEAD WITH A ~20% POP ACROSS OUR EXTREME EAST FOR THURSDAY AFTERNOON. FORECAST PROXIMITY SOUNDINGS FROM ACROSS OUR CWA...PER THE NAM AND OPERATIONAL GFS...SUGGEST PARCELS ROOTED TO AROUND 800MB WILL HAVE ~1000J/KG OF POTENTIAL ENERGY WITH MINIMAL CIN. DEEP LAYER BULK SHEAR OF 30-40KTS IS ALSO EXPECTED OVER THE AREA TONIGHT. SO ALTHOUGH THE THREAT FOR LARGE HAIL DOES NOT SEEM OVERLY IMPRESSIVE...WILL CONTINUE TO MENTION THE POTENTIAL FOR A STRONG STORM...WITH HAIL UP TO THE SIZE OF NICKELS...FOR TONIGHT IN THE HWO. FOR TOMORROW AFTERNOON...LITTLE IF ANY POTENTIAL INSTABILITY IS EXPECTED TO EXIST OVER OUR WEST/NORTHWESTERN CWA SO WENT AHEAD WITH NO MENTION OF THUNDER OUT THAT WAY. ACROSS OUR EXTREME EAST IN THE VICINITY OF THE BAROCLINIC ZONE...THE INTRUSION OF A DRIER LOWER TROPOSPHERIC AIR MASS WILL LIKELY PREVENT POTENTIAL INSTABILITY FROM CLIMBING MUCH ABOVE 1000J/KG...ALTHOUGH DEEP LAYER BULK SHEAR COULD APPROACH 50KTS. WILL GO AHEAD AND MENTION HAIL TO THE SIZE OF NICKELS ACROSS OUR EXTREME EAST IN THE HWO FOR THURSDAY AFTERNOON AS A RESULT. INCREASING SOUTHERLY LOWER TROPOSPHERIC FLOW...ALONG WITH INCREASED CLOUD COVER AND POTENTIAL PRECIPITATION...SHOULD HELP PROMOTE ANOTHER WARM NIGHT TONIGHT WITH LOWS IN THE 50S AND 60S CURRENTLY FORECAST. A COOLER LOWER TROPOSPHERIC AIR MASS WILL WORK INTO THE AREA BEHIND THE BAROCLINIC ZONE DURING THE DAY THURSDAY...THUS PROMOTING A COOLER DAY FOR MOST LOCATIONS ON THURSDAY WHEN COMPARED TO WEDNESDAY. THURSDAY HIGHS IN THE 60S AND 70S ARE CURRENTLY FORECAST FOR MOST LOCATIONS ACROSS THE AREA AS A RESULT. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 333 PM CDT WED MAY 7 2014 ALOFT: MULTI-DAY 500 MB MEANS FROM THE GFS AND EC ENSEMBLES SHOW THAT THE LONGWAVE TROF WILL BE OVER THE WRN USA THRU MON 5/12...WITH THE RIDGE OVER THE ERN USA. THE LEAD SHORTWAVE TROF WILL EXIT E OF THE REGION FRI...TEMPORARILY DEAMPLIFYING THE WRN USA TROF/ERN USA RIDGE. THE LOW CURRENTLY OVER THE GULF OF AK WILL DROP INTO THE WRN TROF SAT...RESULTING IN RE-AMPLIFICATION SUN- MON. BY THIS TIME FRAME...THE USUAL MODEL BIASES APPEAR WITH THE 06Z/12Z GFS ON THE FAST SIDE OF THE GUIDANCE ENVELOP...AND THE 00Z/12Z GEM ON THE SLOWEST SIDE. THE LAST 3 RUNS OF THE EC DO FAVOR THE SLOWER GEM. EVEN THE LAST 3 RUNS OF THE UKMET COINCIDE WITH THE GEM. THAT IS GOOD NEWS FOR RAINFALL. THIS RENEWED TROF WILL ADVANCE INTO THE PLAINS TUE AND THEN INTO THE ERN USA WED-FRI WITH NW FLOW DEVELOPING HERE. THE TROF MOVING INTO THE W SAT LOOKS LIKE IT WILL SEND A SHORTWAVE TROF E INTO THE NRN PLAINS WHILE THE REST OF THE ENERGY DROPS INTO THE INTERMOUNTAIN WEST. SURFACE: NRN PLAINS HIGH PRES WILL SLIP S INTO THE REGION THU NIGHT WITH THE COOL FRONT DEPARTING FURTHER TO THE S AND E. A NEW LEE SIDE TROF WILL DEVELOP FRI...WITH AN OCCLUDED LOW ADVANCING THRU THE NRN PLAINS FRI-SAT /ASSOCIATED WITH THE TROF MENTIONED IN THE PREVIOUS PARAGRAPH/. THE COOL FRONT WILL MOVE THRU HERE FRI NIGHT. THAT FRONT WILL THEN BECOME STATIONARY FROM THE SRN PLAINS TO THE GREAT LAKES SUN AS HEIGHTS FALL IN THE W...AND CYCLOGENESIS COMMENCES. THIS LOW WILL TRACK UP THE FRONT...ACROSS KANSAS CITY MON MORNING...AND SHOULD BE OVER IL BY 00Z/TUE BASED ON THE 00Z EC ENSEMBLE MEAN. EXPANSIVE HIGH PRES WILL ENVELOP THE PLAINS TUE- WED. AS FAR AS SENSIBLE WX...THIS MEANS TEMPS WILL AVERAGE COOLER THAN NORMAL FRI-WED...WITH VERY HIGH POTENTIAL FOR AT LEAST 1 DAY OF MUCH COOLER THAN NORMAL TEMPS. RIGHT NOW IT/S MON. ANOTHER VERY GOOD ASPECT OF THIS SYSTEM IS THAT THE EXITING COOL FRONT WILL NOT PLUNGE DEEP INTO THE S. GULF MOISTURE WILL NOT BE FAR AWAY. THE LOW WILL ALSO BE TRACKING S OF THE FCST AREA. THIS COULD RESULT IN BENEFICIAL/SOAKING RAIN FOR PARTS OF THE FCST AREA. THIS REALLY ISNT MODELED YET...BUT THE PATTERN LOOKS FAVORABLE WITH THE FRONT HAVING ANABATIC CHARACTER. THE 16Z WPC EXTENDED FCST DISCUSSION WAS REVIEWED. HAZARDS: TSTMS ARE POSSIBLE SAT NIGHT INTO SUN S-SE OF THE TRI- CITIES. DOESNT CURRENTLY LOOK FAVORABLE FOR SEVERE. THERE IS A LOW PROBABILITY THAT WE MAY NEED A WIND ADVISORY SOMETIME SUN-MON. THE DAILY DETAILS... FRI: CLEARING AS A SHORTWAVE RIDGE MOVES IN DURING THE AFTERNOON. VERY NICE WITH LIGHT WINDS AND NEAR NORMAL TEMPS. FRI NIGHT: INCREASING MID-HIGH CLOUDS AS THE NEGATIVE TILT NRN PLAINS TROF MOVES THRU ALONG WITH THE EXIT REGION OF A 100 KT TROPOPAUSE JET. A SLIGHT CHANCE OF WARM ADVECTION-INDUCED SPRINKLES HAS BEEN INTRODUCED INTO THE FCST PRIMARILY ALONG AND N OF I-80. CLOUD BASES WILL BE NO LOWER THAN 10K FT. SO IT WILL BE TOUGH TO GET MEASURABLE RAIN. SAT: MORNING COOL FRONTAL PASSAGE. THE CHANCE OF MORNING SHWRS/TSTMS WAS WITHDRAWN FROM THE FCST AND REPLACED WITH A SLIGHT CHANCE OF SPRINKLES N AND E OF THE TRI-CITIES. THEN CLEARING AND A LITTLE WARMER. SAT NIGHT: A 50 KT LOW-LEVEL JET /LLJ/ WILL INDUCE STRONG WARM/MOIST AIR ADVECTION AND FRONTOGENESIS. THIS WILL RESULT IN MCS DEVELOPMENT BUT WITH THE LLJ VEERING THRU THE NIGHT...IT IS LIKELY TO BE E OF THE FCST AREA. SUN-MON: LOTS OF DETAILS LEFT TO BE DETERMINED. BELIEVE ODDS ARE VERY HIGH OUR CURRENT HIGH TEMPS ARE WAY TOO WARM BOTH DAYS. WE ARE BASICALLY CARRYING 60-70F. CONSENSUS OF MODEL 2M TEMPS SUGGEST 50S AND THIS LOOKS MUCH MORE REASONABLE. THIS WILL OCCUR WITH BLUSTERY N WINDS. THE BEST CHANCE FOR RAIN IS CURRENTLY SLATED FOR SUN NIGHT INTO MON MORNING...BUT THIS IS ONLY AVERAGE CONFIDENCE DUE TO MODEL DISAGREEMENT. TUE: DRY WITH NEAR NORMAL TEMPS. NW FLOW ALOFT. WED: NW FLOW MAY DELIVER A WEAK SHORTWAVE TROF...POSSIBLY RESULTING IN A FEW LIGHT SHWRS OR SPRINKLES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 132 PM CDT WED MAY 7 2014 VFR CONDITIONS EXPECTED UNTIL 03Z...MVFR CONDITIONS FORECAST 03-14Z...AND THEN VFR CONDITIONS TO FINISH THE FORECAST PERIOD. PERIODIC CLOUD COVER NEAR 4000FT AGL WILL REMAIN POSSIBLE THIS AFTERNOON INTO TONIGHT. THE DEVELOPMENT OF A ~60KT JET AXIS JUST ABOVE THE BOUNDARY LAYER ACROSS PORTIONS OF NORTH CENTRAL KANSAS AND PERHAPS SOUTH CENTRAL NEBRASKA MAY RESULT IN THE DEVELOPMENT OF STRATUS TONIGHT...WITH MULTIPLE SETS OF GUIDANCE SUGGESTING THIS STRATUS WILL IMPACT GRI. GUIDANCE SUGGESTS A CEILING NEAR 2000FT AGL COULD RESULT AND ALTHOUGH CONFIDENCE IS NOT PARTICULARLY HIGH REGARDING THIS STRATUS...WITH MULTIPLE SETS OF GUIDANCE SUGGESTING SUCH CONDITIONS FELT IT PRUDENT TO INTRODUCE MVFR CONDITIONS TO THE TAF AND LET FUTURE SHIFTS ADJUST AS NECESSARY. THERMAL ADVECTION AND MOISTURE CONVERGENCE NEAR THE NOSE OF THE AFOREMENTIONED JET AXIS COULD ALSO PROMOTE ISOLATED PRECIPITATION PRODUCTION NEAR GRI TONIGHT...WITH CONVECTIVE ACTIVITY ALSO NOT OUT OF THE QUESTION. WENT AHEAD WITH VCTS 08-14Z AS A RESULT. INCREASED DIABATIC HEATING AND INCREASING BOUNDARY LAYER HEIGHT AND MIXING POST-SUNRISE ON THURSDAY SHOULD DIMINISH ANY STRATUS THAT IS REALIZED...THUS THE VFR CONDITIONS WHICH ARE FORECAST 14Z ONWARD IN THE TAF. THE SURFACE WIND WILL REMAIN FAIRLY LIGHT AND AT TIMES VARIABLE THIS AFTERNOON INTO TONIGHT...BUT WILL BECOME MORE ESTABLISHED FROM THE SOUTH OR SOUTHWEST DURING THE DAY THURSDAY. THE WEAK LOWER TROPOSPHERIC WIND FIELD...ALONG WITH NEAR-ZERO LOWER TROPOSPHERIC DEW POINT DEPRESSIONS...COULD ALSO RESULT IN PATCHY FOG TONIGHT AT GRI...THUS 5SM IN BR HAS BEEN INTRODUCED INTO THE TAF 08-14Z. && .GID WATCHES/WARNINGS/ADVISORIES... NE...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR NEZ049-063-064- 074>077-083>087. KS...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR KSZ005>007- 017>019. && $$ SHORT TERM...BRYANT LONG TERM...HALBLAUB AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1250 PM CDT WED MAY 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM CDT WED MAY 7 2014 ISOLATED ELEVATED STRONG TO SEVERE THUNDERSTORMS ARE ONGOING THIS MORNING. THE HRRR AND RAP REALLY ARE NOT HANDLING THE STORM TRACK AS THESE METEOROLOGICAL CHALLENGED MODELS PREFER TO TRACK THE ACTIVITY MORE NORTHEAST THROUGH NORTHWEST NEB VS THE WRN SANDHILLS. THIS LIKELY A RESULT OF THE STORM(S) BECOMING ROOTED IN THE LOW LEVEL EASTERLIES. AT ANY RATE THE CURRENT THINKING IS THE STORMS WILL EITHER WEAKEN BEFORE 12Z OR CONTINUE TRACKING TOWARD SCNTL SD. A BLEND OF THE NAM...RAP...ECM...SREF AND THE PREVIOUS FORECAST SUGGESTED SCATTERED POPS THIS MORNING BECOMING LIKELY THIS AFTERNOON. THE RAP HAS ANALYZED A CLOSED H700MB LOW OVER NORTHEAST COLO AT 07Z WHICH LIFTS NORTHEAST THROUGH NWRN NEB THIS MORNING TO FOLLOWED BY A SECOND AND THIRD H7 WAVES THIS AFTERNOON AND EARLY THIS EVENING. THIS WOULD LIKELY KEEP THE WARM SECTOR FROM KIML TO KONL AND SOUTH DRY TODAY. THE NAM SUGGESTS SOME CONVECTION COULD DEVELOP OFF THE FRONT RANGE THIS AFTN AND SWEEP NORTHEAST THROUGH THE SRN AND NERN ZONES. THE THREAT OF SEVERE WEATHER IS OBVIOUS WITH BULK SHEAR 50 KTS OR GREATER AND STEEPENING LAPSE RATES WITH THE APPROACHING 4 CORNERS LOW. SPC HATCHED AN EGG OF VERY LARGE HAIL ACROSS THE WRN SANDHILLS AND PANHANDLE. THIS IS ALONG AND NORTH OF SFC FRONT WHICH IS EXPECTED TO LIFT THROUGH SRN AND NERN NEB LATE THIS AFTN. VERY LARGE HAIL IS POSSIBLE WITH STORMS THIS AFTERNOON AND EVENING AND MOST IF NOT ALL OF THIS SHOULD BE IN THE COLD AIR NORTH OF THE SFC FRONT. THE 5 PERCENT TORNADO AND 15 PERCENT WIND PROBABILITIES WOULD APPEAR CONDITIONALLY TIED TO STORMS FORMING ALONG THE SFC FRONT WHICH LIFTS NORTH OF I-80 AROUND 21Z THIS AFTN AND THEN DROPS BACK SOUTH. SEVERE WEATHER CONTINUES THIS EVENING...PRESUMABLY ELEVATED...WITH THE APPROACH OF THE MAIN UPPER LEVEL LOW. THE NAM AND OTHER MODELS LIFT A DECENT SHOT OF PV15 THROUGH THE FCST AREA. MEANWHILE...LATE SEASON ARCTIC AIR...CURRENTLY IN MONTANA DROPS THROUGH THE HIGH PLAINS FOR A ZONE OF THUNDERSTORMS CHANGING TO WET HEAVY SNOW. THE NAM BACKS THE ELEVATED INSTABILITY RIGHT UP AGAINST THE RAIN SNOW LINE ACROSS SHERIDAN COUNTY AROUND 09Z. THIS MIGHT BE TOO SLOW GIVEN THE PROXIMITY OF THE COLD AIR ACROSS MT AND THE RAIN SNOW LINE OVER NERN WY. THE RAP CAN FIGURE THIS OUT LATER TODAY. FOR NOW THE RAP HAS THE H700MB FREEZING LINE MOVING THROUGH SERN WY AT 00Z THIS EVENING SO A QUICKER CHANGE TO SNOW IS POSSIBLE. THE BEST GUESS ON SNOW AMOUNTS USES THE NAM...GEMREG...SREF AND ECM FOR QPF WITH A 5 OT 1 RATIO FOR UP TO 4 INCHES IN NORTHERN SHERIDAN COUNTY THROUGH 12Z THURSDAY MORNING. LOCALLY HIGHER AMOUNTS COULD DEVELOP ESPECIALLY IF THE CHANGE OVER OCCURS AT 06Z VS THE NAM MODEL SHOWING 09Z. THE RAP HAS BEEN THE BEST PERFORMER THIS SPRING IN RAIN SNOW EVENTS FOLLOWED THE NAM. A WINTER WEATHER ADVISORY IS IN PLACE FOR SHERIDAN COUNTY 09Z-15Z TONIGHT THROUGH THURSDAY MORNING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 335 AM CDT WED MAY 7 2014 LARGE UPPER LEVEL TROUGH WILL CONTINUE TO SHIFT EAST NORTHEAST ACROSS THE CENTRAL PLAINS ON THURSDAY...REACHING THE NORTHERN MISSOURI VALLEY EARLY FRIDAY. IN THE WAKE OF THE UPPER TROUGH ...QUASI-ZONAL FLOW WILL PREVAIL THROUGH MUCH OF THE WEEKEND...BUT EVENTUALLY BREAK DOWN WITH THE APPROACH OF THE NEXT APPRECIABLE WESTERN STATES UPPER TROUGH. THE SURFACE PATTERN FAVORS A NORTHEASTWARD ADVANCING LOW TOWARD MINNESOTA AND FINALLY INTO SOUTHWEST ONTARIO BY EARLY FRIDAY. THIS LOW WILL DRAG A FRONT THROUGH THE CWA LEAVING POST FRONTAL CONDITIONS INTO EARLY FRIDAY...BUT THE LOWER TROPOSPHERIC FLOW WILL RETURN TO SOUTHERLY AS A LEE TROUGH DEVELOPS OFF THE HIGH PLAINS FRIDAY WITH THE APPROACH OF A WEAK NORTHERN PLAINS UPPER WAVE. THIS WAVE...AS IT/S PREDECESSOR...WILL DRAG AN ADDITIONAL FRONT THROUGH THE CWA ON SATURDAY. THE SATURDAY BAROCLINIC ZONE IS FORECAST TO BE WEAK...WITH LITTLE TO NO SENSIBLE CHANGES ANTICIPATED. FOR THURSDAY...WINTER WEATHER ADVISORY ACROSS SHERIDAN COUNTY WILL CONTINUE UNTIL 15Z. ALL THE MEDIUM RANGE DETERMINISTIC MODELS HAVE CONVERGED SOMEWHAT ON A SOLUTION FOR WHICH THERMAL PROFILES WOULD SUPPORT SNOW ACROSS SHERIDAN COUNTY. THERMAL PROFILES INDICATE A DEEP SATURATION...AT TIMES EXTENDING INTO THE DGZ...BUT WARM GROUND TEMPERATURES AND SFC T/S NEAR OR SLIGHTLY ABOVE 0C CREATE LOW CONFIDENCE FORECAST CONCERNING ACCUMULATIONS. SINCE A STRONG DEFORMATION ZONE IS SHOWN TO SET UP IN THIS AREA...CO-LOCATED IN THE TROWAL REGION OF THE SYSTEM...SNOW RATES MAY BE SUFFICIENT TO OVERCOME THE HIGH SUN ANGLE AND WARM TEMPERATURES...BUT CONFIDENCE IS NOT ENOUGH TO EXPIRE THE ADVISORY BEFORE 15Z. CONSEQUENTLY...GIVEN THE STRENGTH OF THE DEFORMATION...SNOW RATES MAY BE SUFFICIENT TO ALLOW FOR SLUSH ACCUMULATION PAST 15Z THURSDAY. FORECAST TIMING WITH THE CURRENT WINTER WEATHER ADVISORY MAY CHANGE WITH NEAR TERM GUIDANCE. WITH LOW LEVEL CAA ONGOING...HIGH TEMPERATURES THURSDAY WILL BE CHILLY...40S FOR THE NORTHWEST...POSSIBLY SOME 60S SOUTHEAST. WILL NEED TO MONITOR CLOUDS THURSDAY NIGHT AND FRIDAY MORNING AS ANY CLEARING WOULD LEAD TO SUB 0C LOWS...WITH THE THREAT OF A LIGHT FREEZE. ATTM...FAVORING THE ECMWF SOLUTION WHICH IS ON SLOWER SIDE...KEEPING SUFFICIENT CLOUDS ACROSS MUCH OF THE FORECAST AREA TO PREVENT A WIDESPREAD FREEZE. ATTM...NORTHWEST NEBRASKA WOULD HAVE THE HIGHEST POTENTIAL OF SEEING A DAMAGING FREEZE /TO YOUNG PLANTS/...ESPECIALLY IF SNOW TOTALS ARE HIGHER THAN CURRENTLY ANTICIPATED. THE ENTIRE NORTH PLATTE CWA HAS NOT REACHED THE 50 PERCENTILE FOR LAST FREEZE DATE...WE DO NOT PLAN TO FROST/FREEZE HEADLINES ATTM. FRIDAY...WITH RETURN FLOW DIRECTING WAA BACK INTO THE CWA...TEMPERATURES SHOULD WARM BACK WELL INTO THE 60S...POSSIBLY LOWER 70S FOR THE ENTIRE CWA. BUT A FAST MOVING WAVE PASSING THROUGH THE QUASI-ZONAL FLOW MAY SPARK OFF A SHOWER OR TWO DURING THE EVENING AND EARLY ON SATURDAY...WITH A WEAK WIND SHIFT TO FOLLOW. AGAIN SATURDAY TEMPERATURES WON/T BE TOO FAR OFF FROM CLIMO...GENERALLY HIGHS IN THE 60S TO LOWER 70S CAN BE EXPECTED FOR MOST IF NOT ALL LOCATIONS. LATE WEEKEND INTO EARLY NEXT WEEK...ANOTHER SYSTEM LOOKS TO MOVE INTO THE CENTRAL ROCKIES SATURDAY NIGHT AND EMERGE ONTO THE PLAINS SUNDAY AND MONDAY. WIDESPREAD PRECIPITATION WILL BE POSSIBLE...AND DESPITE DIFFERENCES WITH THE HANDLING OF THE SYSTEM...WILL MAINTAIN 30-40 POPS LATE WEEKEND INTO EARLY NEXT WEEK FOR MUCH OF THE CWA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1249 PM CDT WED MAY 7 2014 COMPLEX STORM SYSTEM TO BRING AN ARRAY OF WEATHER TO THE AREA THIS AFTERNOON THROUGH TOMORROW MORNING. THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND LIFT TO THE NORTHEAST ACROSS THE AREA. THESE STORMS COULD PRODUCE SOME LARGE HAIL AND DAMAGING WINDS. DID INCLUDE TSRA AT KLBF...HOWEVER KLBF LIKELY TO BE ON THE EAST SIDE OF THE ACTIVITY. HIGHER CONFIDENCE KVTN WILL SEE AN IMPACT FROM THUNDERSTORMS. THEN A COLD FRONT WILL PUSH ACROSS THE AREA WITH MVFR CIGS...POSSIBLY IFR CIGS...BEHIND THE FRONT. WINDS INCREASE BEHIND THE FRONT AND NORTHERN NEB...INCLUDING THE KVTN AREA...WILL SEE RAIN SHOWERS. FAR NORTHWEST NEBRASKA COULD SEE SOME SNOW LATE TONIGHT INTO TOMORROW MORNING. CONDITIONS IMPROVE TOMORROW MORNING...ESPECIALLY IN THE SOUTHWEST PART OF NEBRASKA. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 3 AM TO 9 AM MDT THURSDAY FOR NEZ004. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
137 PM CDT WED MAY 7 2014 .UPDATE... ISSUED AT 137 PM CDT WED MAY 7 2014 NO SIGNIFICANT CHANGES WITH THIS UPDATE OTHER THAN TO ADJUST POPS FOR THE LATEST RADAR TRENDS THROUGH 1830 UTC...BLENDED TO THE 17 UTC RAP AND THE REMAINING 12 UTC DETERMINISTIC CONSENSUS WHICH SUGGESTS PRECIPITATION DECREASING SIGNIFICANTLY BY 21-00 UTC AND THROUGH THE NIGHT. DID MAINTAIN A MENTION OF SNOW ACROSS THE WEST WITH MULTIPLE LOCATIONS AT LEAST INTERMITTENTLY CONTINUING TO REPORT SNOW. UPDATE ISSUED AT 1026 AM CDT WED MAY 7 2014 UPDATE TO ADD SNOW AND SLEET TO PORTIONS OF NORTHWEST AND NORTH CENTRAL NORTH DAKOTA THIS MORNING FOR LOCATIONS IN THE MID TO UPPER 30S AS OF 1530 UTC. THIS IS BASED UPON MULTIPLE REPORTS BETWEEN WATFORD CITY AND WILLISTON AND THE KEENE AREAS AND DUAL POL SIGNATURES. UPDATE ISSUED AT 826 AM CDT WED MAY 7 2014 QUICK UPDATE TO ADJUST POPS TO THE LATEST OBSERVED TRENDS THROUGH 13 UTC...INCORPORATING THE 11 UTC RAP/HRRR THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY EVENING. ALSO DECREASED CLOUD COVER ACROSS THE NORTHWEST WHERE LOW TO MID LEVEL DECKS ARE THINNING WHICH SHOULD LEAD TO AT LEAST PARTLY SUNNY SKIES. UPDATE ISSUED AT 650 AM CDT WED MAY 7 2014 CURRENT RADAR OBS/TRENDS MATCH THE ONGOING FORECAST. FURTHERMORE...THE LATEST HRRR MATCHES THE LATEST RADAR OBS AND FORECAST TRENDS. WILL CONTINUE TO LEAN HEAVILY ON THE HRRR FOR HOURLY POPS THROUGH THE AFTERNOON. OTHERWISE...THE CURRENT FORECAST IS ON TRACK WITH NO MAJOR UPDATES REQUIRED. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 324 AM CDT WED MAY 7 2014 THE LATEST WATER VAPOR CONTINUES TO SHOW A MOIST SOUTHWEST FLOW INTO NORTH DAKOTA WITH MULTIPLE SHORTWAVES AHEAD OF A MAIN UPPER LOW NOW ALONG THE NEVADA/UTAH BORDER. THIS LOW WILL CLOSE OFF AND PIVOT NORTHEAST THROUGH THE SHORT TERM PERIOD...AND WILL BECOME THE MAIN PRECIPITATION PRODUCER OVER SOUTH CENTRAL NORTH DAKOTA LATER WEDNESDAY NIGHT. UNTIL THEN...MODEL GUIDANCE SUGGESTING SEVERAL AREAS OF RAIN SHOWERS WILL MOVE FROM SOUTHWEST TO NORTHEAST TODAY AND THUS FAR LOCAL/REGIONAL RADAR CONFIRMS THIS. OVERALL POPS ARE LIKELY TO CATEGORICAL FOR WESTERN AND MOST OF CENTRAL NORTH DAKOTA TODAY...WITH THE JAMES RIVER VALLEY SEEING HIGHEST POPS LATER THIS AFTERNOON AND AGAIN LATE WEDNESDAY NIGHT. CATEGORICAL POPS HAVE BEEN PAINTED ALONG/NEAR A SURFACE INVERTED TROUGH/BAROCLINIC ZONE...WHICH CURRENTLY STRETCHES FROM SHERWOOD TO MINOT...SOUTH TO CENTER AND INTO MOBRIDGE SOUTH DAKOTA. THIS SURFACE TROUGH WILL SHIFT EAST DURING THE DAY REACHING THE JAMES RIVER VALLEY LATE THIS AFTERNOON. ONCE THIS TROUGH EXITS THE JAMES RIVER VALLEY EARLY THIS EVENING...EXPECT A BRIEF LULL IN THE WIDESPREAD PRECIPITATION...ESSENTIALLY COVERING THE 00Z-06Z THURSDAY TIME FRAME. HOWEVER POPS WILL ONCE AGAIN INCREASE ACROSS THE SOUTH AND SOUTH CENTRAL TOWARD AND AFTER 06Z THURSDAY IN RESPONSE TO THE VERTICAL MOTION FIELD AS THE CLOSED MID LEVEL LOW APPROACHES. HAVE MAINTAINED THE TREND TO KEEP ANY MENTION OF THUNDER SOUTH OF THE BORDER AS INSTABILITY PARAMETERS PER GFS FOLLOW THIS TREND. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 324 AM CDT WED MAY 7 2014 AN UPPER LEVEL SHORTWAVE EMANATING FROM THE ROCKIES IS PROGGED TO LIFT NORTH ACROSS THE CENTRAL AND NORTHERN PLAINS THURSDAY. THIS FEATURE SHOULD GENERATE RAIN SHOWERS EXTENDING ALONG AND SOUTH OF A LINE FROM HETTINGER TO BISMARCK TO HARVEY. HOWEVER...HIGH PRESSURE BUILDING INTO EASTERN MONTANA SHOULD KEEP THE FORECAST DRY FOR NORTHWESTERN NORTH DAKOTA. A BREAK IN PRECIP CHANCES IS FORECAST FOR FRIDAY AS HIGH PRESSURE CRESTS ACROSS THE REGION. TEMPERATURES ARE FORECAST TO GET IN THE MID TO UPPER 60S FRIDAY. PRECIPITATION CHANCES RETURN OVER NORTH DAKOTA SATURDAY AS A SHORTWAVE EMANATING FROM THE PACIFIC NORTHWEST TRAVERSES THE NORTHERN PLAINS. THE MEDIUM RANGE MODELS DIVERGE WITH RESPECT TO THE UPPER PATTERN OVER THE CONUS SUNDAY THROUGH THE REMAINDER OF THE PERIOD. THEREFORE...THERE IS QUITE A BIT OF UNCERTAINTY REGARDING THE FORECAST FOR THE FIRST HALF OF NEXT WEEK. EVEN THOUGH A PERSISTENT UPPER LEVEL LOW OVER SASKATCHEWAN IS FORECAST TO MAINTAIN AN UNSETTLED WEATHER REGIME OVER NORTH DAKOTA...THE MODELS HAVE BEEN BACKING OFF ON PRECIP CHANCES/QPF AMOUNTS DUE TO DRY SLOTTING. AS A RESULT...LOWERED POPS TO SLIGHT CHANCE/LOW-END CHANCE SUNDAY AND MONDAY...AND REMOVED POPS FOR MOST OF THE CWA TUESDAY. TEMPERATURES ARE STILL FORECAST TO REMAIN BELOW CLIMO VALUES THIS WEEKEND THROUGH THE FIRST PART OF NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 137 PM CDT WED MAY 7 2014 IFR CONDITIONS AT KDIK AND KMOT IN RAIN...STRATUS AND FOG WILL CONTINUE TO IMPROVE TO MVFR BY LATE THIS AFTERNOON. MVFR CONDITIONS IN RAIN WILL CONTINUE AT KBIS THROUGH 20 UTC AND 22-23 UTC AT KJMS. MVFR CONDITIONS IN STRATUS ARE POSSIBLE AT KBIS/KJMS THEREAFTER. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...KS LONG TERM...TM AVIATION...AYD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
339 PM CDT WED MAY 7 2014 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 311 PM CDT WED MAY 7 2014 CURRENT SURFACE ANALYSIS SHOWING A SURFACE TROUGH AXIS LOCATED THROUGH NORTHWESTERN IOWA WITH A WARM FRONT EXTENDING EASTWARD ACROSS THAT AREA. HAVE SEEN SOME SCATTERED CONVECTION DEVELOP THROUGH THE NORTHERN JAMES RIVER VALLEY ALONG THE EDGE OF A STRONG CAP LOCATED ACROSS MOST OF THE REST OF THE CWA PER SPC MESOANALYSIS...WITH THIS CONVECTION TRENDING OFF TO THE NORTHEAST AT THIS TIME. THE RAP13 HAS HANDLED CONVECTIVE TRENDS FAIRLY WELL THROUGH THE DAY...WITH THE HRRR LESS SO...AND THE RAP AS WELL AS A COUPLE HI RES MODELS INDICATING ADDITIONAL CONVECTIVE DEVELOPMENT SOMEWHERE IN THE VICINITY OF THE IOWA GREAT LAKES/PORTIONS OF SOUTHWESTERN MINNESOTA IN THE LATE AFTERNOON/EARLY EVENING...IF THE CAP CAN BE BROKEN. SOUNDINGS WOULD SUGGEST THIS TO BE A POSSIBILITY BY LATE AFTERNOON AS A WEAK MID LEVEL WAVE TRACKS THROUGH THE REGION. IF THIS WERE TO OCCUR...PRESENT INSTABILITY AND EFFECTIVE SHEAR VALUES RUNNING AROUND 40 KTS WOULD INDICATE THAT SEVERE STORMS WOULD BE POSSIBLE WITH LARGE HAIL BEING THE MAIN THREAT. OTHERWISE...THE FOCUS FOR ADDITIONAL CONVECTION OVERNIGHT MAY BE CLOSER TO THE MID LEVEL FRONT ORIENTED FROM SOUTH CENTRAL SOUTH DAKOTA THEN CURVING NORTHWARD INTO NORTHEASTERN SOUTH DAKOTA. OTHERWISE...SHORTER TERM MODELS ALSO HINTING CONVECTION DEVELOPING THROUGH SOUTHERN NEBRASKA...POSSIBLY WORKING NORTHWARD INTO PORTIONS OF OUR SOUTHERN CWA LATE TONIGHT...THOUGH MUCH UNCERTAINTY ON THIS SCENARIO WITH MODEL DIFFERENCES. THERE WILL BE A WIDE RANGE OF TEMPERATURES ACROSS THE AREA TONIGHT...WITH COOL UPPER 40S IN OUR FAR WEST ON THE BACKSIDE OF THE LOW PRESSURE...WHILE DROPPING ONLY INTO THE LOWER 60S THROUGH NORTHWESTERN IOWA WHICH WILL REMAIN IN THE WARM SECTOR OF THE SYSTEM. MODELS IN FAIRLY DECENT AGREEMENT ON THE SURFACE LOW PULLING INTO SOUTHWESTERN MINNESOTA BY THURSDAY EVENING...THOUGH DIFFERING ON STRENGTH AND DURATION OF THE DRY SLOT ACROSS OUR AREA. THE NAM/GEM ARE MORE AGGRESSIVE WITH THIS FEATURE...KEEPING OUR EAST FAIRLY DRY THROUGH MUCH OF THE DAY...THROUGH THE GFS/ECMWF OFFER A WETTER SOLUTION. IN ANY EVENT...BETTER CHANCES OF PRECIPITATION WILL EXIST ACROSS THE NORTH AND WEST IN THE COOLER/DEEPER SATURATED LAYER. THERE AGAIN WILL BE A WIDE RANGE IN TEMPERATURES ACROSS THE AREA...WITH PLACES IN THE WARM SECTOR OUT AHEAD OF THE LOW CLIMBING INTO THE 70S TO NEAR 80...WHILE BACK TO THE WEST HIGHS WILL ONLY MAKE IT INTO THE 50S. AS FAR AS SEVERE WEATHER...IT WILL PROBABLY COME DOWN TO TIMING...AS THE INSTABILITY WANES PRETTY QUICKLY FROM WEST TO EAST THROUGH THE DAY AS THE LOW MOVES EASTWARD...THOUGH IF IT WERE TO OCCUR IT WOULD PROBABLY BE IN OUR FAR EAST DURING THE AFTERNOON AT MAXIMUM HEATING. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 311 PM CDT WED MAY 7 2014 WAVE EXITS RAPIDLY TO THE NORTHEAST THURSDAY NIGHT MAINLY LEAVING RESIDUAL CHANCES FOR RAINFALL. THE ATMOSPHERE STABILIZES QUICKLY... AND THE BEST CHANCE FOR MEASURABLE RAIN WILL BE ALONG AND BEHIND THE WIND SHIFT/COLD FRONT WHERE THE MOISTURE IS DEEPER IN THE STABLE AIR. LOOKING FURTHER TO THE SOUTHEAST...NORTHWEST IA IS MORE IN THE SHALLOW MOISTURE/DRY SLOT AREA SO NOT REAL KEEN ON PRECIP CHANCES IN THAT LOCATION AT THIS TIME. FRIDAY WILL BE A PLEASANT DAY...ALBEIT RATHER BREEZY EAST OF THE JAMES RIVER VALLEY. BUT A WELL MIXED ATMOSPHERE SHOULD GIVE HIGHS WELL INTO THE 60S. IF WE MIX A BIT HIGHER...WE MAY NEED TO TACK ON A COUPLE OF DEGREES MORE TO THESE READINGS. FRIDAY NIGHT IS HIGHLIGHTED BY A STRONG SURGE OF THETAE ADVECTION WHICH IS BASICALLY HARMLESS AS THE ATMOSPHERE REMAINS MOISTURE STARVED BELOW ABOUT 600MB. THERE MAY BE A FEW STORMS MOVING INTO SOUTH CENTRAL SD BY LATE TONIGHT...BUT OTHER LOCATIONS WILL REMAIN DRY WITH LOWS WELL INTO THE 40S. THE THETAE ADVECTION IS IN ADVANCE OF THE NEXT SHORT WAVE PASSAGE ON SATURDAY. BOTH THE NAM AND GFS SHOW THE CRUX OF THE WAVE MOVING THROUGH OUR SOUTHERN AND EASTERN ZONES PER THE UPPER QG FORCING. LOW LEVEL MOISTURE DOES APPEAR TO PICK UP AHEAD OF THE SURFACE WIND SHIFT...SO 50 POPS WERE PLACED EAST OF I 29. ELEVATED INSTABILITY ALSO LOOKS RATHER ABUNDANT AT THIS TIME...SO JUST OPTED TO GO PURE THUNDERSTORMS FOR NOW FOR THE AFTERNOON HOURS GENERALLY ALONG AND EAST OF I 29. FOR HIGHS...SATURDAY LOOKS LIKE ANOTHER BREEZY AND WELL MIXED DAY AND WITH A WARM LOWER ATMOSPHERE...WE ARE LOOKING AT UPPER 60S IN HURON TO MID 70S AT SIOUX CITY AND STORM LAKE. IN THE EXTENDED...THERE IS STILL QUITE A BIT OF DISCREPANCY BETWEEN THE VARIOUS DETERMINISTIC SOLUTIONS. THEREFORE BLENDED THE SOLUTIONS. THE ECMWF CONTINUES TO BE THE SOLUTION WHICH IS THE MOST BULLISH WITH REGARDS TO RAINFALL IN THE SUNDAY THROUGH MONDAY NIGHT TIME FRAME. BUT ADMITTEDLY IT IS DIFFICULT TO TELL BECAUSE EACH MODEL HAS BEEN VERY CONSISTENT WITH THEIR RESPECTIVE OUTPUTS. MORE CERTAIN IS THAT TEMPERATURES WILL BE WELL BELOW NORMAL THROUGH THE MIDDLE OF NEXT WEEK WITH BREEZY CONDITIONS LIKELY EARLY IN THE WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1211 PM CDT WED MAY 7 2014 LOW CONFIDENCE IS CONVECTIVE CHANCES THROUGH THE TAF PERIOD WITH MODEL DIFFERENCES...THOUGH MAY SEE SCATTERED THUNDERSTORMS DEVELOP IN SOUTHWESTERN MINNESOTA LATE THIS AFTERNOON...THEN THROUGH CENTRAL SOUTH DAKOTA TONIGHT INTO TOMORROW MORNING. FARTHER TO THE SOUTH AND EAST...DRY SLOT MAY RULE AND DID NOT INCLUDE CONVECTION AT KFSD AND KSUX...THOUGH CANNOT RULE IT OUT. DOES LOOK LIKE CEILINGS WILL LOWER LATER TONIGHT INTO THE MVFR/UPPER IFR RANGE OVER PORTIONS OF THE AREA. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...JM LONG TERM...MJ AVIATION...JM
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
104 PM CDT WED MAY 7 2014 .UPDATE... SEE UPDATED AVIATION DISCUSSION BELOW. MADE A FEW CHANGES TO THE FORECAST THIS MORNING...MAINLY TO DECREASE POP THROUGH THIS AFTERNOON. AN UPPER LEVEL SHORT WAVE JUST OFF TO THE WEST OF ABERDEEN WILL CONTINUE TO PUSH NORTHEASTWARD INTO NORTH DAKOTA. THIS SYSTEM IS PRODUCING LIGHT SHOWERS ACROSS NORTH CENTRAL SOUTH DAKOTA. BETTER LLM AND SHEAR FURTHER EAST IS RESULTING IN MARGINALLY STRONG STORMS WITH RADAR SHOWING SOME SMALL HAIL POSSIBLE. THESE STORMS SHOULD CONTINUE PUSHING INTO SE NORTH DAKOTA WITHIN THE NEXT FEW HOURS. THERE IS A GOOD POSSIBILITY FOR DRY CONDITIONS THROUGH THIS AFTERNOON BEFORE THE NEXT UPPER LEVEL SHORT WAVE MOVES INTO THE REGION FROM THE SOUTHWEST. && .PREVIOUS DISCUSSION... .SHORT TERM...THROUGH FRIDAY WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY CONTINUES BOTH SOUTH AND WEST OF THE CWA THANKS TO SOUTHWEST FLOW ALOFT WITH WEAK EMBEDDED WAVES. THE 06Z HRRR BRINGS CONVECTIVE REMNANTS INTO THE WESTERN CWA THROUGH THE MORNING HOURS...BUT HAVE ALREADY SEEN SIMILAR ATTEMPTS BY SHOWERS TO CROSS INTO THE FORECAST AREA...ONLY TO WASH OUT...SO FORECASTER CONFIDENCE CONTINUES TO REMAIN LOW EVEN IN THE NEAR TERM. MODELS DO HAVE A BETTER DEFINED WAVE MOVING UP FROM THE SOUTH TODAY. BEST ISENTROPIC FORCING WILL SET UP JUST NORTH OF A KMBG TO KPHP LINE. INSTABILITY PEAKS JUST SOUTH OF A WARM FRONT FOR THE EASTERN CWA THIS AFTERNOON AS WELL. LOOKING AT NAM/RAP PROFILES...SURFACE BASED CONVECTION APPEARS UNLIKELY AS THE FRONT IS SOUTH OF THE CWA...AND GUIDANCE HAS A DIFFICULT TIME WARMING ENOUGH TO OVERCOME THE INVERSION. STEEP LAPSE RATES ABOVE THE INVERSION WITH STRONG SOUTHWEST MID LEVEL FLOW WILL SUPPORT A HAIL THREAT IF ANY STORMS DO DEVELOP. OVERNIGHT...A COUPLED JET STRUCTURE WILL SUPPORT AN AREA OF RAIN THAT WILL LIFT OUT OF THE NEBRASKA PANHANDLE THROUGH WESTERN/CENTRAL SOUTH DAKOTA. MOST OF THE GUIDANCE TAKES THIS FEATURE NORTHEAST BETWEEN KPIR AND KMBG...THOUGH SREF GUIDANCE IS A TAD FARTHER WEST. SREF PROBABILITIES SUGGEST FAIRLY HIGH QPF POTENTIAL WITH THIS FEATURE...WHICH IS SUPPORTED WITHIN MOST GUIDANCE. THE GFS IS PEGGED AT NEARLY 30 MICROBARS OF LIFT BY 12Z THURSDAY. TROWAL WRAP AROUND LIGHT RAIN WILL CONTINUE THROUGH THE DAY...BUT WE WILL SEE ISENTROPIC DOWNGLIDE BY LATE AFTERNOON/EVENING HELPING TO DRY US OUT FOR FRIDAY. .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY THE EXTENDED PERIOD CONTINUES THE ACTIVE PATTERN WITH A COUPLE OF SYSTEMS MOVING THROUGH. THE FIRST WEAKER WAVE MOVES OFF THE ROCKIES FRIDAY NIGHT AND INTO EASTERN SD SATURDAY BRINGING SOME SHOWERS AND TSTORMS. THERE WILL LIKELY BE A BRIEF BREAK IN PRECIP SAT MORNING BEFORE A MORE WELL DEVELOPED SFC LOW ENTERS THE CENTRAL PLAINS SAT NIGHT. AT THE SAME TIME AN UPPER LOW WILL DROP DOWN INTO ND. WHILE THE MODELS AGREE ON THE SFC SYNOPTIC PATTERN...THERE IS SOME DISCREPANCY AT JUST WHEN THE UPPER TROF WILL BEGIN TO AFFECT THE NORTHERN PLAINS. THIS WILL INFLUENCE AREAL COVERAGE OF PRECIP DURING ANY GIVEN PERIOD FROM SAT NIGHT THROUGH TUESDAY. THE ECMWF KEEPS THE PRECIP ONLY OVER THE FAR SOUTHERN CWA WHILE THE GFS HAS THE ENERGY FROM THE UPPER LOW DIGGING A LITTLE FARTHER SOUTH ON SUNDAY. KEPT ALLBLEND POPS FOR NOW OVER THE WEEKEND BUT A DRIER SOLUTION IS POSSIBLE. TEMPERATURES WILL TREND DOWN THROUGH THE PERIOD WITH THE COOLEST TEMPS OCCURRING WHEN THE LONGWAVE TROUGH MOVES OVER THE PLAINS. TEMPS WILL BE AROUND 10 DEGREES COOLER THAN AVERAGE BY THE LATTER HALF OF THE EXTENDED. && .AVIATION... 18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS REGIONAL SATL AND RADAR ANALYSIS SHOWS LAST OF THE MORNING SHOWERS AND TSTORMS EXITING THE AREA TO THE NORTH AND NORTHEAST AND SOME BINOVC OR CLR SKIES DEVELOPING ACROSS CENTRAL AND NERN SD. VFR CONDITIONS EXPECTED AT ALL TERMINALS INTO THE AFTN. KEPT VCTS FOR LATER THIS AFTN AT ATY AS EAST CENTRAL SD STANDS THE BEST CHC TO SEE TSTORMS DEVELOP. PUSHED RAIN CHANCES BACK FARTHER INTO THE EVENING FOR ABR AS LATEST GUIDANCE SUGGESTS AREA OF PCPN MOVING IN AFTER SUNSET AND LATE TONIGHT. HELD ONTO RAIN CHANCES FOR PIR AND MBG EARLY THIS EVENING WITH BEST SHOT OF RAIN LATE AS WELL. RAIN IS EXPECTED TO CONTINUE FOR ALL TAF SITES DURING THE MRNG HRS THURSDAY WITH MVFR CIGS. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...SD SHORT TERM...CONNELLY LONG TERM...WISE AVIATION...VIPOND WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
323 PM CDT WED MAY 7 2014 .SHORT TERM (TONIGHT THROUGH ...COMPLEX AND DIFFICULT FORECAST THROUGH THE SHORT TERM REGARDING POPS. WEAK UPPER LEVEL DISTURBANCE AND SUBTROPICAL PLUME OF MOISTURE FROM THE PACIFIC HAS GENERATED WEAK RETURNS ON THE RADAR TODAY ACROSS THE CWA. SPRINKLES AND LIGHT RAIN HAVE REACHED THE GROUND IN ISOLATED LOCATIONS...BUT A DRY 900-650MB LAYER HAS RESULTED IN MOSTLY VIRGA THUS FAR. MODELS VARY WIDELY TONIGHT INTO THURSDAY MORNING WITH PRECIP PLACEMENT... AND THE POORLY SAMPLED PACIFIC PLUME OF MOISTURE AND EMBEDDED DISTURBANCES UPSTREAM ACROSS MEXICO ARE NOT HELPING. GENERALLY MODELS DO SHOW THE AFOREMENTIONED DRY LAYER MOISTENING FROM WEST TO EAST OVERNIGHT THROUGH MIDDAY THURSDAY...ALONG WITH 850MB THETA-E RIDGE AXIS WEST OF THE RIO GRANDE MOVING EAST ON THURSDAY. PWATS BY MIDDAY THURSDAY ARE AROUND 1.8-2 INCHES ACROSS THE CWA. GFS AND HRRR INDICATING ELEVATED CONVECTION MOVING NORTHEAST OUT OF MEXICO INTO THE WESTERN CWA LATER THIS EVENING AND OVERNIGHT... ALONG WITH 4KM TEXAS TECH WRF. ECMWF EVEN MORE BULLISH WITH QPF AMOUNTS AND FARTHER EAST INTO THE COASTAL BEND AND EASTERN BRUSH COUNTRY. HOWEVER...NAM12 WELL NORTHWEST OF THE AREA WITH QPF AND HI RES NMM/ARW KEYING IN ON AREAS SOUTH OF THE CWA. BASED ON SATELLITE TRENDS UPSTREAM IN MEXICO HAVE SIDED TOWARDS LOW END CHANCE POPS FOR NOW ACROSS THE WESTERN HALF OF THE CWA TONIGHT... WITH THE FEELING THAT MID LEVEL DISTURBANCE IN THE SOUTHWEST FLOW ALOFT AND MOISTENING OF THE DRY LAYER OUT WEST WILL ALLOW FOR ELEVATED PRECIP TO REACH THE GROUND. DURING THE DAY ON THURSDAY...AGAIN MODELS ARE GENERALLY CONSISTENT WITH PLACEMENT OF MOISTURE AXIS MOVING WEST INTO CENTRAL AND EVENTUALLY AREAS OF THE CWA. GOOD CHANCES FOR SURFACE BASED CONVECTION TO DEVELOP THE BRUSH COUNTRY AND INLAND AREAS OF THE COASTAL BEND DURING THE DAY ON THURSDAY...AS CAP ERODES AND MID LEVEL DISTURBANCE CONTINUES EAST ACROSS THE CWA. BETTER JET DYNAMICS MAY REMAIN JUST NORTH AND NORTHWEST OF THE CWA. HOWEVER...THERE IS SUFFICIENT DEEP LAYER SHEAR IN PLACE AND IF ANY SIGNIFICANT BREAKS IN CLOUD COVER OCCUR ACROSS THE CENTRAL AND WESTERN CWA THERE COULD BE A FEW STRONGER STORMS. CONVECTION COULD LINGER INTO THURSDAY NIGHT ACROSS THE COASTAL BEND AND VICTORIA CROSSROADS. OVERALL THROUGH...CONFIDENCE IN THE ENTIRE SHORT TERM FORECAST IS LOW GIVEN AFOREMENTIONED REASONS. && .LONG-TERM (FRIDAY THROUGH WEDNESDAY)...NOT A WHOLE LOT OF MODEL CONSENSUS IN THE EXTENDED PERIOD...AND DIFFICULT TO FIND A CLEAR MODEL WINNER SO CONFIDENCE IN THIS PACKAGE IS SOMEWHAT LOWER THAN TYPICAL. GENERAL IDEA IS FOR AN UPPER DISTURBANCE TO TRIGGER SCATTERED PRECIPITATION FRIDAY...THEN TAPERING FRIDAY NIGHT AND SATURDAY. AFTER RIDGING BUILDS IN FOR SUNDAY...A STRONGER WAVE LOOKS TO FORCE A COLD FRONT THROUGH THE REGION. GFS IS MORE THAN 12 HOURS FASTER WITH THE FRONTAL PASSAGE THAN THE ECMWF. BASED ON PROJECTED UPPER AIR PATTERN HAVE SLIGHTLY MORE FAITH IN THE ECMWF SOLUTION AT THIS TIME. TEMPERATURES FROM MONDAY THROUGH WEDNESDAY WILL BE HIGHLY DEPENDENT ON TIMING OF THE FRONT AND OF SURFACE HIGH PRESSURE THAT BUILDS IN BEHIND THE FRONT. GFS AS USUAL IS VERY AGGRESSIVE WITH COOL AIR BEHIND THE FRONT...SO FORECAST PACKAGE IS SOMEWHAT WARMER AND CLOUDIER THAN WHAT NUMERICAL GUIDANCE WOULD SUGGEST. BY WEDNESDAY SUBSIDENT HIGH PRESSURE IS WELL ESTABLISHED WITH DRIER OFFSHORE FLOW. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 75 86 73 87 73 / 20 50 30 40 30 VICTORIA 73 84 73 86 70 / 20 50 30 40 30 LAREDO 77 94 75 97 76 / 40 30 20 30 20 ALICE 74 89 73 90 72 / 30 50 30 40 30 ROCKPORT 74 80 73 86 73 / 20 30 30 40 30 COTULLA 74 92 72 93 71 / 40 50 20 30 20 KINGSVILLE 74 88 74 89 73 / 20 50 30 30 20 NAVY CORPUS 74 82 74 84 74 / 20 40 30 30 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ JR/76...SHORT TERM JV/71...LONG TERM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
359 PM EDT WED MAY 7 2014 .SYNOPSIS... A WEAK FRONTAL BOUNDARY ACROSS SOUTHWEST VIRGINIA INTO WESTERN NORTH CAROLINA TONIGHT WILL RETURN NORTHWARD THURSDAY AS HIGH PRESSURE ALOFT BUILDS ACROSS THE REGION. VERY WARM CONDITIONS THURSDAY AND FRIDAY UNDER THE UPPER RIDGE WILL GIVE WAY TO SHOWERS AND THUNDERSTORMS OVER THE WEEKEND AS AN UPPER TROUGH APPROACHES THE REGION FROM THE WEST. && .NEAR TERM /THROUGH THURSDAY/... AS OF 350 PM EDT WEDNESDAY... REGIONAL WSR-88D IMAGES SHOWED DISSIPATING COMPLEX OF SHOWERS AND THUNDERSTORMS NORTH OF OUR REGION MOVING EAST ACROSS NORTHERN VA TO THE ATLANTIC COAST. SATELLITE PICTURE INDICATED HIGH CLOUDS PUSHING SOUTH ACROSS THE REGION WITH CU FIELDS MAINLY ACROSS THE MOUNTAINS. FRONTAL BOUNDARY REMAINS ACROSS OUR REGION THIS AFTERNOON INTO TONIGHT. CAP IS STILL HOLDING DESPITE THE SOLAR HEATING...BUT IT IS WEAKENING. HRRR GENERATE A FEW SHOWERS ACROSS THE SOUTHWEST HIGH TERRAIN BUT KEPT MOST OF THE STORMS NORTH OF OUR AREA. THE NAM AND GFS GENERATE SOME STORMS ACROSS THE NORTH THIS AFTERNOON INTO THIS EVENING. THUS..ALLOWED FOR JUST A FEW SHOWERS THIS EVENING IN THE HIGHER TERRAIN. UPPER RIDGE IS BUILDING INTO THE REGION FROM THE WEST...AND BAROCLINIC ZONE NORTHWARD TONIGHT. WITH LOW LEVEL MOISTURE AND LIGHT WINDS ELECTED TO ADD THE MENTION OF FOG OVERNIGHT. WENT WITH LOW TEMPERATURES CLOSE TO THE ADJMAVBC WITH READINGS FROM THE LOWER 50S IN THE NORTH TO THE LOWER 60S ACROSS THE RIDGES. THURSDAY WILL BE A VERY WARM DAY AS AN UPPER LEVEL RIDGE PASSES ACROSS THE APPALACHIAN CHAIN. THE COMBINATION OF VERY WARM AIR BUILDING IN FROM THE SOUTHWEST...COMBINED WITH ABUNDANT SUNSHINE AND DOWNSLOPE WIND FLOW WILL ALLOW AFTERNOON TEMPERATURES TO TOP IN THE LOWER 90S IN THE PIEDMONT...WHILE THE MOUNTAINS CAN EXPECT MID 80S TO UPPER 70S...WITH COOLER TEMPERATURES AT HIGHER ELEVATIONS. A STRONG LAYER OF STABLE AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL HINDER SHOWERS AND THUNDERSTORMS DEVELOPMENT. HIGH TEMPERATURE RECORDS IN THE MOUNTAINS ARE IN JEOPARDY THURSDAY REFER TO CLIMATE SECTION. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... AS OF 330 PM EDT WEDNESDAY... RIDGE OVERHEAD THU NIGHT WILL GET PUSHED EAST BY TROUGH DIGGING ACROSS THE MIDDLE OF THE COUNTRY WITH ASSOCIATED SHORTWAVES PUSHING INTO THE OHIO VALLEY FRIDAY. FRONTAL BOUNDARY WORKING TOWARD THE OHIO VALLEY FRIDAY WILL BE BRINGING INCREASED MOISTURE INTO THE MOUNTAINS. THINK ENOUGH CONVERGENCE AND UPPER SUPPORT FOR SHOWERS AND THUNDERSTORMS TO BE ISOLATED TO SCATTERED. ANOTHER WARM DAY WITH HIGHS IN THE 80S. FRI NIGHT-SAT...FRONT SLOWS DOWN AS IT BECOMES MORE PARALLEL TO UPPER FLOW WHICH BECOMES MORE ZONAL. SHOWERS AND STORMS EDGE CLOSER AND BY SATURDAY MORNING THE WRN CWA SHOULD SEE A GOOD THREAT FOR SHOWERS. DO NOT EXPECT TO SEE A SVR THREAT GIVEN TIMING AND BEST UPPER SUPPORT STAYS NORTH OVER THE GREAT LAKES. SATURDAY WILL BE COOLER WITH CLOUD COVER AND SCATTERED SHOWERS/ISOLATED STORMS WITH 70S WEST TO AROUND 80 EAST. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 330 PM EDT WEDNESDAY... OPERATIONAL RUNS OF THE GFS/ECMWF CONTINUE TO DIFFER ON THE PATTERN NEXT WEEK...WITH THE ECWMF ENSEMBLES OVERALL PRETTY CONSISTENT. THE UPPER PATTERN GOES FROM A SOUTHEAST RIDGE TO SOUTHWEST FLOW ALOFT WITH 5H TROUGH DIGGING THRU THE CENTRAL PART OF THE COUNTRY MONDAY AND BECOMING NEGATIVELY TILTED BY MIDWEEK. MAIN FRONT TO MOVE ACROSS OUR REGION WEDNESDAY. FOR THIS FORECAST ENOUGH CONVERGENCE WITH LEE TROUGH...UPPER DIVERGENCE WITH SHORTWAVE OVER THE GULF COAST TO KEEP CHANCE POPS IN SUNDAY. WILL SEE DIURNAL TYPE CYCLE FOR POPS INTO MONDAY WITH SFC HIGH SITUATED OFF THE SE COAST WITH WARM/STATIONARY FRONTAL BOUNDARY LINGERING OVER NOVA/NORTHERN WV. HUMIDITY EXPECTED TO BE ELEVATED AS WELL. AS WE HEAD TOWARD TUE-WED FRONTAL BOUNDARY AND UPPER LEVEL FORCING WILL CLOSE IN WITH BETTER THREAT OF SHOWERS AND STORMS. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... AS OF 135 PM EDT WEDNESDAY... MVFR SCT TO BKN CLOUDS EXPECTED THIS AFTERNOON INTO TONIGHT. MORNING LOW CLOUDS ERODING ACROSS NORTH CAROLINA. CU FIELDS DEVELOPING ACROSS THE MOUNTAINS THIS AFTERNOON. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE ESPECIALLY ACROSS THE HIGHEST TERRAIN ALONG THE SOUTHERN BLUE RIDGE THIS AFTERNOON INTO TONIGHT. HIGH CLOUDS WILL PUSH SOUTH ACROSS NORTHEAST PORTION OF CWA FROM THUNDERSTORMS TO OUR NORTH THIS AFTERNOON INTO THIS EVENING. AS WEDGE CONTINUES TO ERODE OVERNIGHT...EXPECT RETURN TO VFR CONDITIONS ALL AREAS...ALTHOUGH SOME MVFR BR MAY DEVELOP LATE NIGHT/EARLY THU MORNING AT LWB/LYH/BCB. THIS AFTERNOON WINDS SHOULD GENERALLY BE ESE-SE MOST SITES AT SPEEDS OF 5-8KTS...BECOMING CALM/VRB03KT AROUND 00Z THU...THEN SW AFTER 12Z THU. ON THURSDAY...THE FRONT LIFTS TO THE NORTH WITH WARMER AIR ALOFT PUTTING A CAP ON ANY CONVECTION UNDER VFR CU FIELDS. MEDIUM TO HIGH CONFIDENCE IN CEILINGS AND VISIBILITIES. HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION DISCUSSION... BY LATE FRIDAY A COLD FRONT WILL APPROACH FROM THE WEST...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS DURING THE EVENING. BETTER CHANCE FOR SUB-VFR AT TIMES SAT AFTERNOON/EVENING WITH THE FRONT SLOWLY MOVING EAST AND DEEPER MOISTURE IN PLACE. BOUNDARY MAY WASH OUT UPON CROSSING THE AREA BY SUNDAY WITH MAINLY VFR CONDITIONS EXPECTED OUTSIDE OF OCNL MVFR IN SCATTERED AFTERNOON/EVENING SHRA. && .CLIMATE... HIGH TEMPERATURE RECORDS IN THE MOUNTAINS ARE IN JEOPARDY THURSDAY. MAY GET CLOSE IN THE EAST. CURRENT RECORDS FOR MAY 8TH... ROANOKE......94/1940 LYNCHBURG....94/1940 DANVILLE.....92/1986 BLACKSBURG...85/2000 BLUEFIELD....84/2004 LEWISBURG....82/2000 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...KK/RAB NEAR TERM...KK SHORT TERM...WP LONG TERM...WP AVIATION...KK/RAB CLIMATE...PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
142 PM EDT WED MAY 7 2014 .SYNOPSIS... HIGH PRESSURE ALONG THE EAST COAST WILL KEEP A RELATIVELY COOL AIRMASS ACROSS MUCH OF THE REGION TODAY. A WEAK FRONTAL BOUNDARY ACROSS SOUTHWEST VIRGINIA INTO WESTERN NORTH CAROLINA WILL RETURN NORTHWARD THURSDAY AS HIGH PRESSURE ALOFT BUILDS ACROSS THE REGION. VERY WARM CONDITIONS THURSDAY AND FRIDAY UNDER THE UPPER RIDGE WILL GIVE WAY TO SHOWERS AND THUNDERSTORMS OVER THE WEEKEND AS AN UPPER TROUGH APPROACHES THE REGION FROM THE WEST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1130 AM EDT WEDNESDAY... REGIONAL WSR-88D LOOP SHOWED MAIN COMPLEX OF THUNDERSTORMS NORTH OF OUR REGION ACROSS NORTHERN VA AND WESTERN MD. THIS IS WHERE THE BEST INSTABILITY IS LOCATED NORTH OF FRONTAL BOUNDARY. SATELLITE IMAGES SHOWED LOW CLOUDS ERODING ACROSS OUR CWA. DECREASED CLOUD COVER FOR THIS AFTERNOON AND INCREASED TEMPERATURES AND HIGH TEMPERATURES FOR THIS AFTERNOON. HAVE A GOOD AFTERNOON. AS OF 943 AM EDT WEDNESDAY... SATELLITE LOOP SHOWED THAT LOW LEVEL CLOUDS MIXING OUT THIS MORNING...WITH THE RICHES CLOUDS ACROSS SOUTHERN PORTIONS OF CWA. ADJUSTED CLOUD COVER FOR THIS MORNING INTO THIS AFTERNOON WITH LATEST TRENDS. LOOKS LIKE THE NAM AND GFS ARE OVERDONE WITH CONVECTION THIS AFTERNOON FOR CWA. PREFER THE HRRR WITH STORMS STAYING TO THE NORTH OF OUR AREA. MATCHES UP NICELY WITH SWODY1 GENERAL THUNDERSTORM OUTLOOK FOR TODAY. THIS SEEM REASONABLE WITH UPPER RIDGE BUILDING INTO THE REGION FROM THE WEST...AND BAROCLINIC ZONE NORTHWARD TODAY. CAPPED ALOFT WAS QUITE HEALTHY ESPECIALLY ACROSS SOUTHERN PORTIONS OF CWA. WITH PATCHY CLOUDINESS...AND COOL WEDGE WILL HOLD WITH FORECAST HIGH TEMPERATURES FOR THIS AFTERNOON. MAY NEED TO RAISE HIGHS DEPENDING ON CLOUD COVER LATE THIS MORNING INTO THIS AFTERNOON. ONLY MINOR ADJUSTMENTS IN TEMPERATURES AND DEW POINTS IN ISC GRIDS. MORE CHANGES LATER.... AS OF 420 AM EDT WEDNESDAY... QUASI-STATIONARY FRONT OF THE PAST SEVERAL DAYS MOVED BACK WEST AGAIN TUESDAY EVENING...AND EARLY THIS MORNING WAS LOCATED FROM NEAR LWB-BLF-TNB. AS EXPECTED LOW CLOUDS ARE DEVELOPING EAST OF THE FRONT...ESPECIALLY IN UPSLOPE AREAS ALONG THE BLUE RIDGE FROM SIF-ROA-LYH. FAIRLY FAVORABLE WEDGE PATTERN WITH BUILDING RIDGE ALOFT AND SFC HIGH PRESSURE ANCHORED FROM QUEBEC SOUTHEASTWARD TO OFF THE DELMARVA PENINSULA. THUS...EXPECT MUCH OF THE CWA TO REMAIN MOSTLY CLOUDY AND RELATIVELY COOL TODAY WITH EASTERLY MARITIME FLOW. MOST AREAS WILL SEE HIGHS IN THE UPPER 60S TO LOWER 70S EAST OF THE ALLEGHANY FRONT...MID 70S ACROSS THE NC COUNTIES...APPROACHING 80 IN FAR SW VA/SOUTHERN WV...WHICH WILL EITHER REMAIN WEST OF THE WEDGE BOUNDARY OR MOVE BACK INTO THE WARM SECTOR DURING THE AFTERNOON. WITH RESPECT TO CONVECTION...THE CHANCE FOR SUCH IN OUR CWA IS DECREASING. WITH UPPER RIDGE BUILDING INTO THE REGION FROM THE WEST...BAROCLINIC ZONE WILL BE PUSHED NORTHWARD...AND TODAY SHOULD RESIDE FROM NORTHERN WV INTO NORTHERN VA. WITH WARMING TEMPS ALOFT AND A COOL STABLE LAYER AT THE SFC...EXPECT LITTLE IF ANY CONVECTION. IN THE FAR SW WHERE IT WILL BE MORE UNSTABLE IT WILL BE CAPPED ALOFT...SO NOTHING EXPECTED THERE EITHER. HOWEVER...A FEW SHOWERS OR SPRINKLES CANNOT BE TOTALLY RULED OUT...ESPECIALLY THROUGH MID-DAY...BETWEEN THE BLUE RIDGE AND THE ALLEGHANY FRONT ALONG-NORTH OF I-64...SUCH AS WE HAVE SEEN FROM TIME-TO-TIME OVERNIGHT. WITH ALL OF THESE FACTORS IN MIND...HAVE OPTED NOT TO MENTION TSRA FOR THE NEAR TERM. MODEL INSTABILITY IS GROSSLY OVER ESTIMATED AND MY THINKING IS CONSISTENT WITH SPCS LACK OF EVEN A GENERAL THUNDER AREA FOR OUR CWA TODAY. && .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... AS OF 330 AM EDT WEDNESDAY... THURSDAY IS SHAPING UP TO BE DRY AND VERY WARM AS AN UPPER LEVEL RIDGE PASSES ACROSS THE APPALACHIAN CHAIN. THE COMBINATION OF VERY WARM AIR BUILDING IN FROM THE SOUTHWEST...COMBINED WITH ABUNDANT SUNSHINE AND GENERAL DOWNSLOPE WIND FLOW WILL ALLOW AFTERNOON TEMPERATURES TO TOP OUT JUST ABOVE 90 IN A FEW AREAS ACROSS THE SOUTHSIDE...WHILE THE MOUNTAINS CAN EXPECT MID 80S TO UPPER 70S...WITH COOLER TEMPERATURES AT HIGHER ELEVATIONS. A STRONG LAYER OF STABLE AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL KEEP SHOWERS AND THUNDERSTORMS AT BAY. SOUTHWESTERLY FLOW WILL ALSO RESULT IN WARM OVERNIGHT LOWS...WITH MID 50S TO LOW 60S EXPECTED AREAWIDE. UPPER RIDGING WILL SHIFT EAST ON FRIDAY...RESULTING IN SLIGHTLY MORE INSTABILITY...PARTICULARLY DURING LATE AFTERNOON AND EARLY EVENING. CONTINUED SOUTHWESTERLY FLOW WILL RESULT IN ANOTHER WARM DAY. HOWEVER...WITH INCREASING CLOUD COVER AHEAD OF ANOTHER APPROACHING FRONT...EXPECT FRIDAY AFTERNOON HIGHS TO BE SLIGHTLY COOLER THAN THOSE ON THURSDAY. STILL...WILL BE LOOKING AT 80S FOR A MAJORITY OF THE FORECAST REGION. EXPECT A FEW SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE MOUNTAINS WITH MAXIMUM DAYTIME HEATING. INSTABILITY APPEARS TO BE LIMITED...AND WITH ONLY VERY WEAK UPPER LEVEL DISTURBANCES EXPECTED...CONVECTION SHOULD REMAIN SPOTTY AND DISORGANIZED. LONG RANGE MODELS APPEAR IN BETTER AGREEMENT THIS MORNING THAT UPPER LEVEL RIDGING ACROSS THE EAST WILL GIVE WAY TO A MORE ZONAL WEST TO EAST FLOW ON SATURDAY MORNING. THE ZONAL FLOW WILL CAUSE THE APPROACHING COLD FRONT TO LOSE ITS COLD AIR PUSH...FORCING IT TO STALL WEST OF OUR AREA. MINOR UPPER LEVEL DISTURBANCES WILL PASS ACROSS THE REGION THROUGH THE DAY...RESULTING IN ROUNDS OF SHOWER AND SOME THUNDERSTORM ACTIVITY...WITH THE BRUNT OF THE RAINFALL OCCURRING ACROSS THE MOUNTAINS. REGARDLESS...INSTABILITY APPEARS TO BE MARGINAL...AND THE POTENTIAL FOR STRONG THUNDERSTORMS WILL BE REMOTE. INCREASED CLOUD COVER AND SPOTTY RAINFALL WILL MAKE FOR COOLER AFTERNOON TEMPERATURES...WITH HIGHS REACHING INTO THE 70S MOST LOCATIONS...POSSIBLY TOUCHING 80 AROUND DANVILLE. && .LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 330 PM EDT TUESDAY... VARIABILITY IN THE MODELS LEADS TO A LOW CONFIDENCE FORECAST FOR SUNDAY THROUGH TUESDAY. THE GFS FAVORS A MORE ZONAL FLOW ALOFT NEXT WEEK VS. A MORE AMPLIFIED ECMWF SOLUTION. FOR SUNDAY...THE GFS INDICATES A LOW AMPLITUDE RIDGE BUILDING IN FROM THE WEST...WITH ANOTHER FRONT COMING THROUGH ABOUT TUESDAY EVENING. THE ECMWF IS MORE AMPLIFIED WITH THE RIDGING...CAUSING THE SURFACE FRONT TO GET CAUGHT UNDERNEATH THE RIDGE AND HOLD WEST OF OUR AREA. THIS RESULTS IN A WETTER SOLUTION OVERALL FOR THE LONG TERM PERIOD. SINCE THE CURRENT PATTERN FAVORS A MORE AMPLIFIED SOLUTION WILL ENTERTAIN A FORECAST CLOSER TO THE ECMWF. AS SUCH TRENDED THE FORECAST CLOUDIER AND COOLER TO START THE WEEK...TEMPERATURES MONDAY AND TUESDAY WILL BE CLOSER TO NORMAL ALONG WITH A CHANCE OF SHOWERS. BY MID WEEK...FLOW ALOFT SHOULD BECOME SOUTHWEST WITH ANOTHER WARM SURGE PRIOR TO ANY FRONTAL PASSAGE IN THE LATE TUESDAY...THURSDAY TIME FRAME. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AS OF 135 PM EDT WEDNESDAY... MVFR SCT TO BKN CLOUDS EXPECTED THIS AFTERNOON INTO TONIGHT. MORNING LOW CLOUDS ERODING ACROSS NORTH CAROLINA. CU FIELDS DEVELOPING ACROSS THE MOUNTAINS THIS AFTERNOON. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE ESPECIALLY ACROSS THE HIGHEST TERRAIN ALONG THE SOUTHERN BLUE RIDGE THIS AFTERNOON INTO TONIGHT. HIGH CLOUDS WILL PUSH SOUTH ACROSS NORTHEAST PORTION OF CWA FROM THUNDERSTORMS TO OUR NORTH THIS AFTERNOON INTO THIS EVENING. AS WEDGE CONTINUES TO ERODE OVERNIGHT...EXPECT RETURN TO VFR CONDITIONS ALL AREAS...ALTHOUGH SOME MVFR BR MAY DEVELOP LATE NIGHT/EARLY THU MORNING AT LWB/LYH/BCB. THIS AFTERNOON WINDS SHOULD GENERALLY BE ESE-SE MOST SITES AT SPEEDS OF 5-8KTS...BECOMING CALM/VRB03KT AROUND 00Z THU...THEN SW AFTER 12Z THU. ON THURSDAY...THE FRONT LIFTS TO THE NORTH WITH WARMER AIR ALOFT PUTTING A CAP ON ANY CONVECTION UNDER VFR CU FIELDS. MEDIUM TO HIGH CONFIDENCE IN CEILINGS AND VISIBILITIES. HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION DISCUSSION... BY LATE FRIDAY A COLD FRONT WILL APPROACH FROM THE WEST...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS DURING THE EVENING. BETTER CHANCE FOR SUB-VFR AT TIMES SAT AFTERNOON/EVENING WITH THE FRONT SLOWLY MOVING EAST AND DEEPER MOISTURE IN PLACE. BOUNDARY MAY WASH OUT UPON CROSSING THE AREA BY SUNDAY WITH MAINLY VFR CONDITIONS EXPECTED OUTSIDE OF OCNL MVFR IN SCATTERED AFTERNOON/EVENING SHRA. && .CLIMATE... HIGH TEMPERATURE RECORDS IN THE MOUNTAINS ARE IN JEOPARDY THURSDAY. MAY GET CLOSE IN THE EAST. CURRENT RECORDS FOR MAY 8TH... ROANOKE......94/1940 LYNCHBURG....94/1940 DANVILLE.....92/1986 BLACKSBURG...85/2000 BLUEFIELD....84/2004 LEWISBURG....82/2000 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...RAB NEAR TERM...KK/RAB SHORT TERM...NF LONG TERM...NF/PM AVIATION...KK/RAB CLIMATE...PM
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND THURSDAY ISSUED AT 253 PM CDT WED MAY 7 2014 THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE OVER THE KANSAS/NEBRASKA BORDER WITH A WARM FRONT EXTENDING EAST FROM NORTHERN IOWA ACROSS NORTHERN ILLINOIS TO THE CENTRAL APPALACHIANS. NORTH OF THIS WARM FRONT...A SHORTWAVE TURNED MCV IS EXITING THE STATE OVER NORTHERN LAKE MICHIGAN. WAKE LOW WINDS HAVE SUBSIDED BEHIND THIS MCV...BUT SCATTERED CONVECTION CONTINUES TO REDEVELOP FROM WAUSAU TO MANITOWOC IN A REGION OF MID-LEVEL FGEN AND MOISTURE CONVERGENCE ALONG AN 850MB WARM FRONT. THINK THIS CONVECTION WILL LIFT NORTHEAST AND WEAKEN FOR THE REST OF THIS AFTERNOON WHICH SHOULD LEAD TO A PERIOD OF RELATIVELY QUIET CONDITIONS INTO THIS EVENING. LOOKING UPSTREAM...CONVECTION IS DEVELOPING OVER THE EASTERN DAKOTAS AND WESTERN MINNESOTA ALONG AN INVERTED TROUGH. TOUGH TO PICK OUT ANY NOTABLE SHORTWAVES IN THE SOUTHWEST FLOW ALOFT OVER THE PLAINS TO KEY ON FOR PRECIP TONIGHT. WITH BROAD WARM AND MOIST ADVECTION CONTINUE OVER THE NEXT 24 HOURS...THUNDERSTORM AND SEVERE WEATHER CHANCES ARE THE MAIN FORECAST CONCERNS. TONIGHT...AS LOW PRESSURE MOVES INTO THE CENTRAL GREAT PLAINS...AN 850MB WARM FRONT WILL BE LIFTING NORTHWARD ACROSS CENTRAL AND NORTHERN WISCONSIN DURING THE EVENING. THOUGH A PERIOD OF SUBSIDENCE MAY STILL BE ONGOING BEHIND THE MCV THAT IS EXITING NORTHEAST WISCONSIN CURRENTLY...ASCENT OVER THIS WARM FRONT ON THE EDGE OF THE ELEVATED MIXED LAYER SHOULD EVENTUALLY LEAD TO A RE-DEVELOPMENT OF SHOWERS AND THUNDERSTORMS OVER FAR NORTHERN WISCONSIN AND THE UPPER PENINSULA. WITH NO DISCERNIBLE SHORTWAVES UPSTREAM...TIMING OF RE-DEVELOPMENT IS TOUGH TO GET A HANDLE ON...SO KEPT PROBABILITIES IN THE CHANCE RANGE THIS EVENING...AND INCREASED THEM TO LIKELY OVERNIGHT. DUE TO STEEP MID-LEVEL LAPSE RATES IN THE 7-8 C/KM RANGE...ELEVATED CAPES UPWARDS OF 1100 J/KG...AND 0-6 KM BULK SHEARS OF 30-35 KTS...TOUGH TO RULE OUT A MINOR SEVERE THREAT. LARGE HAIL WILL BE THE MAIN THREAT AND DAMAGING WINDS TO A LESSER EXTENT. THURSDAY...LOW PRESSURE WILL LIFT NORTHEAST TOWARDS SOUTH-CENTRAL MINNESOTA. AT THE SAME TIME...A SURFACE WARM FRONT WILL BE SHIFTING NORTHWARD ACROSS THE STATE. HOW QUICKLY THAT WARM FRONT MOVES NORTH IS A BIG QUESTION MARK AS ITS FORWARD PROGRESS WILL LIKELY BE IMPEDED BY MORNING CONVECTION AND CLOUD COVER. IF CLOUDS AND RAINFALL CONTINUE INTO THE AFTERNOON...HAVE A TOUGH TIME SEEING THIS WARM FRONT REACHING THE UPPER PENINSULA BORDER BY 00Z FRI. THE 12Z ECMWF SHOWS THIS WARM FRONT ONLY REACHING THE ROUTE 29 CORRIDOR BY THIS TIME SO THIS SCENARIO IS NOT OUT OF REALM OF POSSIBILITY. WILL SHOW LIKELY POPS OVER N-C WISCONSIN DURING THE MORNING AND A CHANCE EVERYWHERE ELSE AS ISENTROPIC ASCENT CONTINUES. CENTRAL WISCONSIN AND THE FOX VALLEY HAVE THE BEST CHANCE OF CLEARING THE WARM FRONT DURING THE AFTERNOON WHERE TEMPS HAVE POTENTIAL TO REACH INTO THE UPPER 70S TO LOWER 80S. WITH SURFACE DEWPOINTS RISING INTO THE LOWER 60S...ML CAPES WILL RANGE FROM 1500-2000 J/KG OVER CENTRAL WISCONSIN AND THE SOUTHERN FOX VALLEY. 0-6KM BULK SHEAR WILL BE MORE THAN SUFFICIENT FOR THE POSSIBILITY OF DISCRETE CELLS AND WILL HAVE FORCING VIA ISENTROPIC/MOISTURE ADVECTION. LARGE SCALE FORCING WILL STILL BE A CONSIDERABLE DISTANCE TO THE WEST...SO SEVERE WEATHER CHANCES MAY GET DELAYED INTO THE EVENING...BUT CANNOT RULE OUT A FEW SEVERE THUNDERSTORMS TOMORROW AFTERNOON. THE MAIN THREATS WILL BE DAMAGING WINDS AND LARGE HAIL. NO SIGNIFICANT CHANGES TO TEMPS. .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY ISSUED AT 253 PM CDT WED MAY 7 2014 LOW AMPLITUDE/SLIGHTLY AMPLIFIED MEAN FLOW TO GRADUALLY TRANSITION TO A WEST COAST UPR RDG/E-CNTRL NOAM UPR TROF PATTERN NEXT WEEK. THE MAIN FEATURE OF INTEREST WL BE THE PROGRESSIVE EWD MOVEMENT OF A LONGWAVE TROF ACROSS THE CNTRL CONUS EARLY NEXT WEEK. THIS PATTERN SHIFT TO BRING A SW FLOW ALOFT TO NE WI WHICH TRANSLATES TO NEAR NORMAL TEMPS...BUT ALSO A WET PATTERN WITH SEVERAL ROUNDS OF PCPN. SFC LOW CONTS TO SLOWLY TRACK NE ACROSS MN THU NGT WHILE THE CDFNT PUSHES INTO WRN WI DURING THE OVRNGT HOURS. PERSISTENT SW WINDS AHEAD OF THE CDFNT/SHORTWAVE TROF WL CONT TO GET PUMPED INTO WI WITH INDIVIDUAL MID-LEVEL SHORTWAVES LIFTING NE INTO THE GREAT LAKES. ENUF SHEAR IS EVIDENT TO SUPPORT ORGANIZED/ROTATING STORMS...THUS A POTENTIAL OF SEVERE STORMS PERSISTS THU NGT. THE HIGHEST PROBABILITY OF SEVERE LOOKS TO BE TO OUR WEST NEAR THE TRACK OF THE SFC LOW...HOWEVER LARGE HAIL AND/OR DAMAGING WINDS ARE POSSIBLE ACROSS THE ENTIRE FCST AREA. MIN TEMPS TO ACTUALLY HAVE SUMMER FEEL TO THEM WITH DEW POINTS HOLDING IN THE 50S THRU THE NGT. LOOK FOR READINGS TO ONLY DROP INTO THE LWR TO MID 50S AROUND DOOR COUNTY TO THE LWR 60S ACROSS E-CNTRL WI. THE CDFNT DRIVES THRU CNTRL WI FRI MORNING/ERN WI EARLY TO MID FRI AFTERNOON AND WL NEED TO CARRY POPS UNTIL THIS FNT CLEARS THE AREA. EVEN BEHIND THE FNT...CANNOT RULE OUT ADDITIONAL SHWR ACTIVITY AS THE SHORTWAVE TROF/EMBEDDED SHORTWAVE MOVE THRU WI. HAVE CONTINUED THE LOW-END POPS ACROSS THE ENTIRE FCST AREA THRU THE AFTERNOON HOURS. WARMEST TEMPS ON FRI TO BE OVER ERN WI PRIOR TO THE COLD FRONTAL PASSAGE WITH READINGS IN THE UPR 60S. WEAKENING SHORTWAVE TROF IS FCST TO LIFT NE INTO ONTARIO FRI NGT... BUT MAY STILL BE CLOSE ENUF TO NE WI TO WARRANT A SMALL POP OVER NRN SECTIONS OF THE FCST AREA FRI EVENING. OTHERWISE...A WEAK RDG OF HI PRES WL BUILD TOWARD THE WRN GREAT LAKES LATER FRI NGT AND BRING CLEARING SKIES AND COOLER CONDITIONS TO THE REGION. MIN TEMPS TO RANGE FROM THE UPR 30S TO LWR 40S NORTH TO THE LWR TO MID 40S SOUTH. THIS SFC RDG QUICKLY MOVES ACROSS WI ON SAT WITH CLOUDS ALREADY BEGINNING TO INCREASE AHEAD OF A SHORTWAVE TROF PUSHING TOWARD THE UPR MS VALLEY. HAVE KEPT ANY PCPN OUT OF THE FCST AREA FOR NOW AND KEPT MAX TEMPS MAINLY IN THE 65-70 DEG RANGE (COOLER NEAR LAKE MI). UNSETTLED WEATHER EXPECTED FOR THE FIRST HALF OF NEXT WEEK AS AN UPR TROF SLOWLY WORKS ACROSS THE CNTRL CONUS. SW FLOW ALOFT WL BRING GULF MOISTURE INTO THE WRN GREAT LAKES WITH CHC POPS NECESSARY FROM SAT NGT THRU MON NGT. THE PASSAGE OF A CDFNT MON NGT FOLLOWED BY A DRY SLOT ON TUE COULD BRING A BREAK IN THE PCPN BEFORE THE UPR TROF ARRIVES AND BRINGS CHC POPS BACK INTO THE FCST. TEMPS WL COOL A BIT EARLY NEXT WEEK WITH READINGS SLIGHTLY BELOW NORMAL. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1150 AM CDT WED MAY 7 2014 A STRONG WARM FRONT WILL BE LIFTING NORTHWARD ACROSS THE WESTERN GREAT LAKES AND INTO CENTRAL WISCONSIN BY THE END OF THE TAF PERIOD. NORTH OF THE WARM FRONT...PERIODS OF SHOWERS AND THUNDERSTORMS ARE LIKELY...BUT TIMING THESE PERIODS REMAINS VERY DIFFICULT. THE ROUND MOVING ACROSS NORTHEAST WISCONSIN CURRENTLY WILL EXIT OVER THE NEXT HOUR OR TWO...THEN COULD SEE A SEVERAL HOUR BREAK INTO EARLY THIS EVENING. TOUGH TO RULE OUT A POP UP STORM...BUT COVERAGE IS EXPECTED TO BE ISOLATED UNTIL THE EVENING. THEN THE FOCUS WILL LOOK TOWARD FAR NORTHERN WISCONSIN TONIGHT...BUT STORMS COULD TURN SOUTHEAST INTO CENTRAL PARTS OF THE STATE TOO. REDEVELOPMENT OF THUNDERSTORMS IS POSSIBLE BY MID TO LATE EVENING. ANOTHER ROUND OF STORMS COULD ALSO ARRIVE TOMORROW MORNING. WITH THE APPROACHING WARM FRONT...EXPECT CIGS AND VSBYS TO FALL TONIGHT INTO THURSDAY MORNING. && .MARINE... ISSUED AT 253 PM CDT WED MAY 7 2014 FOG IS POSSIBLE LATE TONIGHT INTO TOMORROW AS WARM AND HUMID AIR INVADES FROM THE SOUTH. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KALLAS AVIATION.......MPC MARINE.........MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1245 PM CDT WED MAY 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 425 AM CDT WED MAY 7 2014 AT 3 AM...WATCHING 2 AREAS OF CONVECTION. THE FIRST IS LOCATED OVER EAST CENTRAL WISCONSIN. MEANWHILE THE OTHER ONE IS LOCATED BETWEEN SIOUX FALLS SOUTH DAKOTA AND FAIRMONT MINNESOTA. BOTH OF THESE ARE LOCATED ON THE EASTERN EDGE STRONG 700 MB MOISTURE CONVERGENT AREA. IN ADDITION...THEY ARE LOCATED ONE THE NORTHERN PERIPHERY OF 1000 J/KG MOST UNSTABLE CAPE. THE ARW...NMM...HOP WRF AND SPC WRF SUGGEST THAT THE LATTER AREA OF CONVECTION WILL MOVE EAST ALONG THE INTERSTATE 90 CORRIDOR THIS MORNING. EARLIER IN THE NIGHT THE HRRR SUGGESTED A SIMILAR SCENARIO...BUT WITH ITS LATEST RUN IT HAS BACKED AWAY FROM THIS SOLUTION. HOWEVER THIS SCENARIO DOES NOT MAKE A LOT OF SENSE...SO BACKED AWAY FROM FOLLOWING IT. TRENDED THE PRECIPITATION FORECAST FOR TODAY TOWARD A BLEND OF ARW...NMM...HOP WRF AND SPC WRF. HOWEVER I AM A BIT CONCERNED THAT AS IT MOVES EAST THAT THE NOCTURNAL JET WILL WEAKEN AND THAT THE CONVECTION COULD DISSIPATE BEFORE IT GETS INTO OUR AREA. IF THE CONVECTION DOES HAPPEN TO GET INTO OUR AREA...THE SPC RAP SUGGESTS THAT EFFECTIVE SHEAR WILL INCREASE OVER 40 KNOTS THROUGH 07.14Z. THIS COULD RESULT IN THE DEVELOPMEMT OF SOME ELEVATED SUPER CELLS. WE WILL HAVE TO MONITOR THIS OVER THE NEXT COUPLE OF HOURS. FOR LATER THIS MORNING AND AFTERNOON...MANY OF THE MESO MODELS AND AND NAM SUGGEST THAT THE AREA WILL REMAIN DRY. THIS IS A RESULT OF AN ELEVATED MIXED LAYER BEING BROUGHT ISENTROPICALLY OFF OF THE SOUTHERN PLAINS. THIS LAYER FORMS A STRONG 800 TO 600 MB CAP ACROSS THE FORECAST AREA. MEANWHILE THE GFS CONTINUES TO TRY AND DEVELOP STRATIFORM PRECIPITATION BELOW THE CAP. THIS LOOKS VERY UNLIKELY BECAUSE ITS SATURATED THE AIR MASS BELOW 800 MB TOO MUCH. DUE TO THIS...STAYED WITH A DRY FORECAST FOR THE TIME PERIOD. TONIGHT...MANY OF DETERMINISTIC RUNS ARE GENERATING PRECIPITATION ACROSS MUCH OF THE FORECAST AREA. HOWEVER BUFKIT SOUNDINGS CONTINUE TO SHOW A FAIRLY STRONG CAP ALONG AND SOUTH OF INTERSTATE 94. THIS IS GOOD AGREEMENT WITH WHAT SHOWS UP IN THE ARW AND SPC WRF. DUE TO THIS...WENT WITH MUCH LOWER POPS THAN WHAT NORMALLY WOULD BE EXPECTED SOUTH OF INTERSTATE 94. IF THUNDERSTORMS DID DEVELOP...IT LOOKS TO BE SO HIGH /BASES OF 2 TO 3 KM/ THAT YOUR SHEAR IS GREATLY DECREASED TO LESS 25 KNOTS...SO THERE WILL NOT BE SUPERCELLS. HOWEVER THE CAPE PROFILE IS MUCH FATTER THAN THIS MORNING AND THIS COULD POTENTIALLY RESULT IN SOME LARGE HAIL. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 425 AM CDT WED MAY 7 2014 ON THURSDAY AND THURSDAY NIGHT...THE 07.00Z MODELS CONTINUE TO SHOW THAT A PLUME OF SUBTROPICAL MOISTURE WILL SURGE NORTHWARD AHEAD OF THE LONG WAVE TROUGH. EMBEDDED WAVES IN THIS FLOW WILL RESULT IN SHOWERS AND THUNDERSTORMS WHICH WILL USE UP MUCH OF THE CAPE PRIOR TO THE ARRIVAL OF A MUCH MORE FAVORABLE SHEAR PROFILE. DUE TO THIS...STILL THINKING THAT THE BEST SEVERE WEATHER THREAT WILL REMAIN WEST OF INTERSTATE 35. WITH THIS PLUME NOT ARRIVING UNTIL MID MORNING...LOWERED THE PRECIPITATION PROBABILITIES BETWEEN 08.12Z AND 08.15Z. FROM SATURDAY NIGHT THROUGH TUESDAY...A SERIES OF SHORT WAVE TROUGHS WILL EJECTED OUT OF THE LONG WAVE OVER THE WESTERN UNITED STATES. THIS WILL BRING ROUND OF SHOWERS AND THUNDERSTORMS INTO THE AREA. WITH STILL SOME TIMING DIFFERENCES AND SUBTLE DIFFERENCES IN THE MODELS...STAYED WITH THE MODEL CONSENSUS. TOWARD THE MIDDLE OF NEXT WEEK...IT LOOKS LIKE THERE WILL BE A PATTERN SHIFT AS THE UPPER LEVEL FLOW BECOMES NORTHWEST AND WEST ACROSS THE EASTERN UNITED STATES. LOOKS LIKE HIGHS MAY RANGE FROM THE UPPER 40S TO MID 50S...AND LOWS WILL RANGE FROM THE MID 30S TO MID 40S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1245 PM CDT WED MAY 7 2014 IN THE WAKE OF MORNING STORMS...COOL STABLE EASTERLY FLOW HAS ANCHORED THE WARM FRONT WELL TO THE SOUTH ACROSS CENTRAL IOWA. IN THE PAST COUPLE HOURS...THERE HAS BEEN A SLOW PUSH TO THE NORTH BUT NOT EXPECTING THE FRONT TO MAKE IT TO THE TAF SITES UNTIL THE SURFACE LOW BEGINS TO LIFT MORE TO THE NORTH THIS EVENING. FOR THE OVERNIGHT PERIOD...SOME INDICATIONS THAT STORMS COULD FIRE UP ACROSS SOUTHWEST MINNESOTA INTO CENTRAL MINNESOTA. UNCERTAINTY REMAINS WHETHER KRST WILL BE IMPACTED...BUT FOR NOW INCLUDED A VCTS GROUP. THIS ACTIVITY SHOULD LIFT AWAY FROM THE AREA BY SUNRISE. AFTER 12Z THURSDAY...INCREASING MOISTURE AND LIFT ASSOCIATED WITH THE STRONGER SURFACE LOW AND COLD FRONT TO THE WEST WILL LEAD TO WIDESPREAD SHOWERS AND THUNDERSTORMS...ESPECIALLY CLOSER TO 18Z. THIS IS WHEN THE MOST IMPACTS TO THE TERMINALS COULD BE EXPERIENCED. && .HYDROLOGY... ISSUED AT 425 AM CDT WED MAY 7 2014 FLOODING CONTINUES ALONG THE MAIN STEM OF THE MISSISSIPPI RIVER...WITH LOCATIONS CRESTING FROM NORTH MCGREGOR. SHOWERS AND THUNDERSTORMS ON THURSDAY AND THURSDAY NIGHT WILL PRODUCE ANYWHERE FROM A HALF INCH TO ONE INCH. THIS WILL LIKELY SLOW THE FALL FOR LOCATIONS NORTH OF MCGREGOR...AND MAY INCREASE CRESTS SLIGHTLY SOUTH OF MCGREGOR. CHECK OUT THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM....BOYNE AVIATION.....ZT HYDROLOGY....BOYNE