Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/04/13


AREA FORECAST DISCUSSION
NWS PUEBLO CO
905 PM MDT WED APR 3 2013 .UPDATE... ISSUED AT 905 PM MDT WED APR 3 2013 CURRENT WATER VAPOR IMAGERY INDICATING AN EMBEDDED SHORT WAVE TRANSLATING ACROSS SOUTH CENTRAL WYOMING AND INTO NORTH CENTRAL COLORADO AT THIS TIME. REGIONAL RADARS INDICATING SHOWERS ALONG WITH A FEW LIGHTNING STRIKES ASSOCIATED WITH THIS SYSTEM MOVING ACROSS NORTHERN COLORADO AT THIS TIME. LATEST NAM AND RAP HAVE SHOWERS DIMINISHING AS THEY CONTINUE TO MOVE SOUTH AND EAST WITH ONLY INCREASING MID AND AND HIGH LEVEL CLOUDS ACROSS SOUTH CENTRAL AND SOUTHEAST COLORADO. HOWEVER...THE LAST FEW RUNS OF THE HRRR IS INDICATING A FEW SHOWERS MOVING OUT ACROSS THE FRONT RANGE AND INTO NORTHERN AND EASTERN PORTIONS OF EL PASO COUNTY AFTER MIDNIGHT. HAVE NOT BOUGHT OFF ON THIS SCENARIO WITH SHOWERS SEEMINGLY DIMINISHING WITH THE LOSS OF HEATING...THOUGH WILL NEED TO MONITOR LATEST HRRR TRENDS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 313 PM MDT WED APR 3 2013 CURRENTLY... SKIES CLEARING PRETTY QUICKLY FROM NW TO SE ACROSS THE REGION. ONLY AREA OF CONSIDERABLE CLOUDINESS AT 2 PM WAS OVER THE FAR SE PLAINS. Q WAS BUBBLING OVER THE S MTNS. TEMPS WERE IN THE 40S OVER THE PLAINS WHERE THERE WAS SUN...AND 30S WHERE IT WAS CLOUDY. THE SLV WAS IN THE 50S. REST OF TODAY INTO TONIGHT... RIDGING WILL BUILD OVER THE FCST AREA AND SKIES WILL CONTINUE TO CLEAR. A FEW CONVECTIVE SHOWERS WILL BE POSSIBLE OVER THE SAN JUANS AND S MTNS THE REST OF THIS AFTERNOON AND EARLY EVENING. OTHERWISE EXPECT CLEARING SKIES. THE ONLY CONCERN I HAVE FOR TONIGHT WILL BE PATCHY GROUND FOG IN PLACES. BASED ON CURRENT RH PROGS...BEST CHANCE FOR SOME FOG WILL BE OVER THE FAR E PLAINS...MAINLY ALONG THE ARK RVR. TEMPS TONIGHT WILL BE COOL WITH U20S TO L30S ACROSS THE PLAINS...AND 20S VALLEYS. THURSDAY... 500 MB RIDGE AXIS WILL BE OVER THE STATE BY LATE AFTERNOON. TEMP-WISE...TOMORROW WILL BE QUITE A NICE DAY WITH HIGHS IN THE L70S MOST OF THE PLAINS WITH 60S IN THE VALLEYS. SKIES WILL BE MOSTLY SUNNY. NO PRECIP IS EXPECTED. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 313 PM MDT WED APR 3 2013 SOME ADJUSTMENTS NEEDED DURING THE LONGER TERM WITH MAIN METEOROLOGICAL ISSUES CONTINUING TO BE TEMPERATURES...GUSTY WINDS AT TIMES...ELEVATED FIRE WEATHER CONCERNS FROM FRIDAY AFTERNOON INTO FRIDAY EVENING...THUNDERSTORM THREAT OVER PORTIONS OF THE FAR EASTERN PLAINS...ESPECIALLY FROM SUNDAY EVENING INTO SUNDAY NIGHT AND FINALLY THE IMPACT THAT UPPER SYSTEM WILL PRODUCE OVER THE FORECAST DISTRICT EARLY NEXT WEEK. IT STILL APPEARS THE RELATIVELY BENIGN AND MILD TO WARM METEOROLOGICAL CONDITIONS SHOULD BE NOTED OVER THE CWFA INTO FRIDAY...THANKS TO A TRANSITORY UPPER RIDGE MOVING ACROSS THE AREA. IN ADDITION...ELEVATED FIRE CONCERNS ARE STILL ANTICIPATED FROM FRIDAY AFTERNOON INTO FRIDAY EVENING...ESPECIALLY OVER PORTIONS OF FIRE WEATHER ZONES 222/224/225/228>233 AND 235 DUE TO PROJECTED LOW MINIMUM RELATIVE HUMIDITIES AND GUSTY WINDS AT TIMES. AS TOUCHED UPON IN PREVIOUS DISCUSSIONS...UPPER LEVEL DISTURBANCES...IMPACTING PRIMARILY NORTHERN PORTIONS OF THE FORECAST DISTRICT WITH INCREASED PRECIPITATION CHANCES ARE PROJECTED TO IMPACT THE CWFA FROM LATER FRIDAY INTO THE WEEKEND...ALLOWING FOR SOMEWHAT COOLER TEMPERATURES AS WELL AS GUSTY WINDS AT TIMES. IN ADDITION...INCREASED THUNDERSTORM CHANCES MAY BE NOTED OVER FAR EASTERN PORTIONS OF THE FORECAST DISTRICT FROM SUNDAY EVENING INTO SUNDAY NIGHT AS DEEPER ATMOSPHERIC MOISTURE INTERACTS WITH RELATIVELY HEALTHY 0 TO 6 KM BULK SHEARS. UPPER TROUGH SHOULD THEN IMPACT THE FORECAST DISTRICT BY EARLY NEXT WEEK WITH THE HIGHEST POTENTIAL FOR WIDESPREAD PRECIPITATION PROJECTED FROM LATER MONDAY INTO AT LEAST TUESDAY NIGHT. HAVE PAINTED GENERALLY SCATTERED POPS DURING THIS TIME-FRAME WITH A POTENTIAL FOR HEALTHY ACCUMULATING SNOW...ESPECIALLY OVER HIGHER TERRAIN AREAS. WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY. GUSTY WINDS WILL BE POSSIBLE FROM FRIDAY INTO FRIDAY NIGHT AND THEN AGAIN FROM NEXT TUESDAY INTO TUESDAY NIGHT. WARMEST TEMPERATURES OF THE LONGER TERM ARE EXPECTED FRIDAY WHILE COOLEST CONDITIONS ARE ANTICIPATED BY NEXT TUESDAY AND WEDNESDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 313 PM MDT WED APR 3 2013 VFR CONDITIONS ARE EXPECTED THE NEXT 24H AT ALL 3 TAF SITES...KPUB...KALS AND KCOS. THE ONLY CONCERN I HAVE AT EACH OF THESE SITES IS SOME PATCHY GROUND FOG DEVELOPING LATE TONIGHT/EARLY TOMORROW MORNING...HOWEVER PROBABILITY OF IT OCCURRING APPEARS TOO LOW TO MENTION EXPLICITLY IN THE TAF PRODUCT. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MW SHORT TERM...HODANISH LONG TERM...77 AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1059 AM MDT TUE APR 2 2013 .UPDATE... && .SHORT TERM...MOST IF NOT ALL OF CWA HAS BEEN UNDER AN AREA OF DRIER AIR AHEAD OF THE MAIN UPPER LOW OVER EASTERN UTAH. SOME CLEARING NOTED EARLIER ACROSS SUMMIT COUNTY. LATEST MODELS DO HAVE THE MOISTURE INCREASING AND PRECIP REDEVELOPING BY THE AFTERNOON. BEGINNING TO SEE SOME CLOUD ENHANCEMENT ACROSS MOUNTAINS AND ALONG FOOTHILLS. BASED ON CURRENT CONDITIONS...BACKED OFF ON PRECIP CHANCES ACROSS MOUNTAINS...FOOTHILLS AND VALLEYS THIS MORNING. AS FOR PLAINS...DROPPED THE MENTION OF THE PRECIP THROUGH 18Z MOST AREAS EXCEPT NEAR THE FOOTHILLS AND WYOMING BORDER. KEPT SOME LOW POPS ALONG THE PALMER DIVIDE AS WELL. BY AFTERNOON...INCREASING MOISTURE AND INSTABILITY ALONG WITH LIFT WILL ALL COMBINE TO INCREASE THE PRECIP CHANCES. LATEST RAP INCREASES THE EASTERLY FLOW AFTER 21Z...PROVIDING UPSLOPE. OVERALL...CURRENT FORECASTS FOR THIS AFTERNOON AND EVENING SEEM REASONABLE. WILL BOOST THE FOOTHILLS POPS A BIT AFTER 21Z THROUGH THE EVENING. SNOW LEVELS BETWEEN 5 AND 7 THOUSAND FEET THIS AFTERNOON STILL SEEMS REASONABLE...LOWERING TO 4 TO 6 THOUSAND FEET TONIGHT. OVERALL... PRECIP WILL GENERALLY BE LIGHT. THERE MAY BE SOME AREAS WHERE SHOWERS COULD BE HEAVIER...PERHAPS IN EAST FACING SLOPES. .AVIATION...EARLIER CLEARING HAD FILLED IN AS LOCAL MESOCYCLONE BROUGHT MVFR CEILINGS TO THE AREA AIRPORTS. STILL EXPECTING CEILINGS TO IMPROVE A BIT AROUND 18Z...THEN LOWER AGAIN AFTER 21Z AS RAIN SHOWERS DEVELOP. SOME SNOW WILL MIX WITH THE RAIN BY 00Z. AREAS OF MVFR/IFR CONDITIONS POSSIBLE WITH THE HEAVIER SHOWERS FROM 21Z THROUGH 06Z...THEN A GRADUAL IMPROVEMENT OVERNIGHT. INSTRUMENT APPROACHES LIKELY FOR MOST OF THE TIME. && .PREV DISCUSSION... /ISSUED 451 AM MDT TUE APR 2 2013/ SHORT TERM...UPPER LOW OVER UTAH WILL MOVE SLOWLY ESE TOWARD SOUTHEAST COLORADO BY WEDNESDAY MORNING. MEANWHILE MOIST SOUTH TO SOUTHEAST LOW LEVEL FLOW WILL CONTINUE OVER THE PLAINS. AIRMASS WILL REMAIN SLIGHTLY UNSTABLE...WITH SOME LOW LEVEL STABILITY OVER THE PLAINS THIS MORNING AS THERE IS SOME WARM ADVECTION OFF THE GROUND...AND THEN SLIGHT COOLING ALOFT THIS EVENING AS THE COLD POOL WITH THE LOW MOVES OVER. WITH THE DRIER AIR ALOFT THERE IS NOT MUCH TO PRODUCE SIGNIFICANT SHOWERS THIS MORNING...THOUGH WEAK CONVERGENCE AND LIFT IN THE MOIST LOWER LEVELS COULD PRODUCE SOME DRIZZLE OR SHALLOW SHOWER ACTIVITY. CONVECTION ON THE EDGE OF THE COLD POOL COULD ALSO CLIP THE NORTHERN MOUNTAINS. EXPECT SHOWERS TO BREAK OUT THIS AFTERNOON AS BEST LIFT...SLIGHT COOLING...AND LOW LEVEL CONVERGENCE ALL INCREASE. BEST TIME WILL LIKELY BE IN THE LATE AFTERNOON AND EARLY EVENING AS THE LOW SLIDES SOUTH OF OUR AREA AND WITH A LITTLE HELP FROM DIURNAL HEATING. I LOWERED POPS A LITTLE THIS MORNING...AND RAISED THEM MAINLY FOR THE MOUNTAINS THIS AFTERNOON AND EVENING. AMOUNTS WILL GENERALLY BE LIGHT THOUGH IF THERE COULD BE SOME ORGANIZATION THE FOCUSED CONVECTION COULD PRODUCE HEAVIER AMOUNTS. TWO POSSIBILITIES FOR THIS...SLOW MOVING SHOWERS OVER THE CREST OR EAST SLOPES OF THE FRONT RANGE COULD PRODUCE SUSTAINED MODERATE TO HEAVY SNOW FOR SEVERAL HOURS. ALSO MODELS HAVE BEEN PRODUCING NARROW SNOW BANDS ON THE PLAINS IN THE DEFORMATION ZONE ON THE NORTH SIDE OF THE LOW WITH UP TO 6 INCHES OF SNOW...BUT IN DIFFERENT PLACES. THIS IS CERTAINLY POSSIBLE THOUGH THE DEFORMATION ZONE WILL LIKELY BE SINKING SOUTHWARD WHICH SHOULD SPREAD THAT BAND OUT A BIT. TEMPERATURES WILL ALSO BE RATHER WARM...SO FAR WE HAVE BEEN A BIT WARMER THAN THE MODELS SHOW. EXPECTING SNOW LEVELS BETWEEN 5 AND 7 THOUSAND FEET TODAY AND 4 TO 6 THOUSAND FEET TONIGHT. WE MAY YET NEED TO RAISE POPS FOR A BETTER CHANCE OF LIGHT PRECIPITATION AT THE PEAK OF THIS LATE TODAY...BUT OVERALL PRECIPITATION WILL GENERALLY BE LIGHT WITH WARM TEMPERATURES. SOME TRAVEL IMPACT POSSIBLE UNDER HEAVIER SHOWERS...BUT EXPECT COVERAGE OF THAT TO BE LOCALIZED. SYSTEM WILL SINK SOUTH LATER TONIGHT AND WE SHOULD SEE SOME CLEARING IN THE NORTH BY MORNING. LONG TERM...MODELS HAVE THE UPPER LOW OVER SOUTHEASTERN COLORADO/NORTH CENTRAL NEW MEXICO AT 12Z WEDNESDAY MORNING. BY 12Z THURSDAY MORNING...IT IS WELL EAST OF THE CWA WITH NORTHWESTERLY FLOW ALOFT IN PLACE HERE. BY THURSDAY NIGHT...AN ADVANCING UPPER RIDGE`S AXIS IS OVER THE CWA. THE FLOW ALOFT IS WESTERLY AND FAIRLY LIGHT. THE QG VERTICAL VELOCITY FIELDS SHOW WEAK DOWNWARD SYNOPTIC SCALE ENERGY FOR THE FORECAST AREA WEDNESDAY THROUGH THURSDAY EVENING. THE BOUNDARY LAYER FLOW LOOKS TO ADHERE TO NORMAL DUIRNAL PATTERNS ALL FOUR PERIODS WITH A FAIRLY WEAK PRESSURE GRADIENT PROGGED. FOR MOISTURE...THERE IS SOME LINGERING ON WEDNESDAY...BUT IT DECREASES THROUGH THE DAY. IT IS PRETTY DRY WEDNESDAY NIGHT. THERE IS SOME MID AND UPPER LEVEL MOISTURE AROUND THURSDAY AND THURSDAY...WITH THE GFS SHOWING A LOT IN THE UPPER LEVELS AFTER 06Z FRIDAY MORNING EARLY. THERE IS A BIT OF CAPE PROGGED OVER THE MOUNTIANS AND FOOTHILLS ON THE NAM ONLY FOR LATE DAY WEDNESDAY. THERE IS A TAD OF MEASURABLE PRECIPITATION ON THE QPF FIELDS LATE DAY WEDNESDAY...OTHERWISE NOTHING THROUGH THE PERIODS. WILL GO WITH 20-30%S IN THE MOUNTAINS ON WEDNESDAY. OTHERWISE NO POPS ANYWHERE FOR THE REST OF THE PERIODS. FOR TEMPERATURES...WEDNESDAY`S HIGHS ARE 3-6 C WARMER THAN TUESDAY`S. THURSDAY`S HIGHS ARE 3-5 C WARMER THAN THURSDAY`S. FOR THE LATER DAYS...FRIDAY THROUGH MONDAY...MODELS HAVE A WEAK UPPER TROUGH TO MOVE ACROSS FRIDAY AFTERNOON AND EVENING. ON SATURDAY INTO SUNDAY...FAIRLY STRONG WESTERLY FLOW ALOFT IS PROGGED...WITH UPPER TROUHGING SUNDAY NIGHT THROUGH MONDAY NIGHT. MOISTURE INCREASES ON FRIDAY AND THERE IS QUITE A BIT AROUND LATE SUNDAY THROUGH MONDAY NIGHT. AVIATION...EXPECT SCATTERED RAIN SHOWERS TO DEVELOP THIS AFTERNOON AND CONTINUE THIS EVENING...MIXING WITH OR CHANGING TO SNOW AFTER DARK. TEMPERATURES SHOULD STAY AT OR ABOVE FREEZING WHICH WILL LIMIT SNOW ACCUMULATION. MVFR CONDITIONS WILL GRADUALLY LIFT THIS MORNING...THEN CEILINGS WILL LOWER AGAIN AS THE SHOWERS DEVELOP LATE TODAY WITH AREAS OF MVFR CEILINGS/VISIBILITIES AND IFR CONDITIONS POSSIBLE IN THE HEAVIER SHOWERS FROM 21Z TO 06Z...THEN IMPROVING CONDITIONS AGAIN. INSTRUMENT APPROACHES TO KDEN WILL LIKELY BE NEEDED MOST OF THE TIME THROUGH THIS EVENING. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...D-L LONG TERM....RJK AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MIAMI FL
1015 AM EDT TUE APR 2 2013 .UPDATE... THE LATEST VISIBLE SATELLITE IMAGERY SHOWED THE LARGE STRATUS DECK OVER MUCH OF THE INTERIOR SECTIONS CLEARING AND BURNING OFF AS OF 9-10AM. THIS CLEARING TREND WILL CONTINUE THROUGH THE LATE MORNING HOURS WITH MOSTLY SUNNY SKIES EXPECTED THROUGH THE EARLY AFTERNOON. THE LATEST OBSERVATIONS AROUND THE AREA INDICATED VISIBILITIES HAVE IMPROVED SIGNIFICANTLY WITH NO RESTRICTIONS DUE TO FOG. HOWEVER...SMOKE FROM THE WILDFIRE IN COLLIER COUNTY WILL CONTINUE TO IMPACT SOME OF THE AREAS...WHICH INCLUDES I75 MOSTLY IN COLLIER COUNTY WHERE A FEW AREAS OF THE HIGHWAY REMAIN CLOSED. ELSEWHERE...ANOTHER PLEASANT DAY IS EXPECTED WITH HIGHS FORECAST TO REACH THE LOWER 80S ALONG THE COAST TO THE MID TO UPPER 80S FARTHER INLAND. LOW-LEVEL FLOW WILL QUICKLY SHIFT TO THE NORTH AND NORTHEAST THROUGH THE AFTERNOON...WHICH SHOULD ALLOW FOR SOME INCREASE IN LOW-LEVEL MOISTURE. THIS INCREASE IN MOISTURE COMBINED WITH THE DAYTIME HEATING SHOULD INDUCE A LOW-LOW CU FIELD ACROSS THE INTERIOR LOCATIONS AND POSSIBLY A FEW SHOWERS THROUGH THE LATE AFTERNOON HOURS AS THE WEST COAST SEA BREEZE PUSHES INLAND. && .PREV DISCUSSION... /ISSUED 745 AM EDT TUE APR 2 2013/ UPDATE... FOR THE SHORT TERM...DENSE FOG CONTINUES TO AFFECT MOST OF THE SOUTH FLORIDA PENINSULA. THE ONLY TERMINALS NOT CURRENTLY AFFECTED WITH IFR VISIBILITY RESTRICTIONS ARE KMIA AND KOPF...BUT THESE TERMINALS COULD EXPERIENCE BRIEF PERIODS OF MIST AND/OR FOG OVER THE NEXT HOUR OR SO WITH SUB-VFR VIS RESTRICTIONS AND WILL AMEND AS NECESSARY. OTHERWISE...BY MID MORNING AND THROUGH THE AFTERNOON MAINLY VFR CONDITIONS EXPECTED ALL TERMINALS. WITH LIGHT VARIABLE FLOW THIS MORNING...THE WEST AND EAST COAST SEA BREEZES ARE EXPECTED TO FORM TODAY. 60 PREV DISCUSSION... /ISSUED 647 AM EDT TUE APR 2 2013/ UPDATE... SHORT TERM MODELS CONTINUE TO INDICATE THE POSSIBILITY OF AN AFTERNOON SHOWER IN THE INTERIOR PORTION OF THE STATE LATER THIS AFTERNOON. THE MAIN FOCUS WILL BE THE CONVERGENCE OF THE SEA BREEZE. CONFIDENCE IS STILL LOW, BUT FEEL THERE IS ENOUGH OF A CHANCE TO PUT A MENTION IN THE FORECAST FOR TODAY. PREV DISCUSSION... /ISSUED 447 AM EDT TUE APR 2 2013/ DISCUSSION... THE WEATHER FOR THE MOST PART IS QUIET. THERE IS SOME DENSE FOG IN THE WESTERN HALF OF THE FORECAST AREA, AND SOME LOCALIZED FOG NEAR TAMIAMI. SO, A DENSE FOG ADVISORY IS IN PLACE FOR PORTIONS OF SOUTH FLORIDA. THIS FOG SHOULD BURN OFF WITHIN A COUPLE OF HOURS AFTER SUNRISE. OTHERWISE, HIGH PRESSURE IS BUILDING IN TODAY. AREAS IN THE INTERIOR PORTIONS OF THE STATE WILL SEE HIGH TEMPERATURES IN THE MID TO UPPER 90S. COASTAL AREAS WILL SEE HIGHS IN THE LOW TO MID 80S. THERE SHOULD BE A DECENT SEA BREEZE TO DEVELOP TODAY. WITH SOME MOISTURE, WILL HAVE TO WATCH FOR INDICATIONS THAT SOME SHOWERS MAY DEVELOP IN THE INTERIOR, ESPECIALLY IF THERE IS ANY SEA BREEZE CONVERGENCE. NAM MODEL SOUNDINGS ARE SHOWING A GOOD CAP BETWEEN 500 AND 600 MB. THE HRRR IS HINTING THAT SOMETHING MAY DEVELOP, BUT IT IS AT THE END OF ITS MODEL RUN AND WOULD LIKE TO SEE WHAT IT DOES WITH THIS BEFORE PUTTING ANYTHING IN THE FORECAST FOR THIS AFTERNOON. HAVE KEPT POPS JUST BELOW SLIGHT CHC FOR THE INTERIOR FOR NOW. BY WEDNESDAY, A DEVELOPING LOW OVER THE WESTERN GULF OF MEXICO WILL CAUSE THE DEVELOPMENT OF A WARM FRONT ACROSS NORTH FLORIDA. THIS WILL ALLOW FOR A SOUTHEASTERLY FLOW, WHICH WILL HAVE SOME LIFT. THIS COULD ALLOW SOME SHOWERS TO DEVELOP ALONG THE BORDER WITH CENTRAL FLORIDA. HAVE KEPT SLIGHT CHANCE POPS IN FOR THAT AREA INTO THE EVENING HOURS. SPC DOES OUTLOOK THE AREA FOR A GENERAL THUNDERSTORM, BUT THERE IS BETTER 500MB VORTICITY ADVECTION TO THE NORTH, OVER CENTRAL FLORIDA. SO, KEPT THUNDERSTORMS OUT OF THE FORECAST FOR WEDNESDAY AFTERNOON WITH THIS FORECAST ISSUANCE. THE LOW, THAT CAUSED THE WARM FRONT, WILL QUICKLY STRENGTHEN AND MOVE NORTHEAST OVER THE FLORIDA PANHANDLE BY FRIDAY MORNING. THE ASSOCIATED COLD FRONT WILL MAKE ITS WAY ACROSS THE GULF AND WILL FIRST IMPACT CENTRAL FLORIDA. MODELS ARE STILL IN PRETTY GOOD AGREEMENT WITH THE STRENGTH, PLACEMENT, AND TIMING OF THE LOW, WITH A FEW MINOR DISCREPANCIES. THEY SHOW THE SOUTH FLORIDA COULD SEE SOME SHOWER ACTIVITY MOVING INTO THE AREA BY 12Z FRIDAY. THERE ARE INDICATIONS THAT A PRE-FRONTAL TROUGH WILL MOVE ACROSS THE AREA BY 18Z AND THEN THE MAIN FRONT WILL PUSH THROUGH SOMETIME AROUND 00Z SATURDAY. THERE IS A STRONG 500MB TROUGH/LOW, DEPENDING ON WHICH MODEL YOU LOOK AT, ASSOCIATED WITH THIS SYSTEM. THIS WILL HELP TO DEVELOP SOME HEAVIER SHOWERS. THE MAIN QUESTION IS THE THREAT OF THUNDERSTORMS. CURRENTLY, IT IS DIFFICULT TO TELL HOW HIGH THE PROBABILITY OF THUNDERSTORMS WILL BE. THE REASON IS THAT THE ATMOSPHERE COULD GET MIXED WELL BY THE PRE-FRONTAL TROUGH AND KEEP THE SKIES CLOUDY, REDUCING DAYTIME HEATING. THIS COULD REDUCE THE POTENTIAL, BUT DONT THINK ELIMINATE IT. HAVE KEPT HIGH CHC POPS IN FOR FRIDAY AND EVEN MENTION A SLIGHT CHANCE FOR TSTMS LATE THURSDAY NIGHT. IF THE ATMOSPHERE IS NOT TOO MIXED EARLY ON, THERE COULD BE A DECENT COVERAGE OF STORMS, AND SOME OF THOSE COULD BECOME STRONG. BUT, IT IS STILL TOO FAR OUT TOO MAKE ANY REAL ASSUMPTIONS. SO WILL KEEP IT SIMPLE WITH A CHC OF SHOWERS AND TSTMS FOR NOW. BEHIND THIS FRONT, TEMPERATURES ARE NOT GOING TO BE TOO GREATLY AFFECTED AND HIGH PRESSURE WILL BUILD IN TO BRING QUIET WEATHER FOR THE WEEKEND AND THE BEGINNING OF NEXT WEEK. CURRENTLY LOOKING AT MID TO UPPER 70S FOR THE COASTAL AREAS TO LOW 80S IN THE INTERIOR PORTIONS ON SATURDAY, WITH HIGH A FEW DEGREES HIGHER ON SUNDAY. MARINE... HIGH PRESSURE WILL BUILD IN TODAY. THIS WILL KEEP THE WEATHER QUIET OVER THE GULF AND ATLANTIC WATERS FOR TODAY THROUGH TOMORROW MORNING. AN APPROACHING SYSTEM WILL BRING A CHANCE FOR SOME SHOWERS TO THE AREA AS EARLY AS WEDNESDAY LATE AFTERNOON. FIRE WEATHER... FOG IS THE MAIN FIRE WEATHER CONCERN THIS MORNING. SOME OF THE AREAS ARE DENSE, AND MAYBE MORE SO DUE TO THE SMOKE FROM THE HUCKABEE FIRE IN COLLIER COUNTY. CONDITIONS SHOULD IMPROVE WITHIN A COUPLE OF HOURS AFTER SUNRISE. HIGH PRESSURE WILL BUILD IN TODAY AND HIGH TEMPERATURES WILL FLIRT WITH 90 DEGREES IN THE INTERIOR. THIS WILL LIKELY ALLOW A SEA BREEZE TO DEVELOP THIS AFTERNOON. CURRENT MODELS DO SHOW THE SEA BREEZES CONVERGING OVER THE CENTRAL PART OF THE STATE, QUITE POSSIBLY NEAR THE HUCKABEE FIRE. THIS COULD LEAD TO BETTER INSTABILITY IN THE VICINITY OF THE FIRE. THERE IS ALSO A SMALL POSSIBILITY OF SOME SHOWERS DEVELOPING IN THE AREA THEY CONVERGE, BUT TOO EARLY TO TELL. A LOW WILL BEGIN TO DEVELOP IN THE WESTERN GULF TODAY AND A WARM FRONT WILL SET UP OVER NORTH FLORIDA. THIS COULD ALLOW SOME SHOWERS TO BEGIN TO DEVELOP AS FAR SOUTH AS HENDRY/INTERIOR COLLIER COUNTIES TOMORROW AFTERNOON. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE AREA FRIDAY, BRINGING SHOWERS AND POSSIBLY THUNDERSTORMS TO THE AREA BEGINNING EARLY FRIDAY MORNING, THROUGH FRIDAY EVENING. PREV DISCUSSION... /ISSUED 138 AM EDT TUE APR 2 2013/ AVIATION... FOG WAS BEGINNING TO DEVELOP ACROSS THE INTERIOR AND TOWARDS KAPF EARLY THIS MORNING. MVFR CONDITIONS ARE EXPECTED TO DEVELOP OVER THE NEXT FEW HOURS THROUGH 14Z. IFR CONDITIONS COULD BRIEFLY OCCUR AT KAPF. SEA FOG IS POSSIBLE TO THE WEST OF KAPF OVER THE GULF TODAY AS WELL. LIGHT WINDS WILL CONTINUE OVERNIGHT. SEA BREEZE BOUNDARIES ARE EXPECTED TO DEVELOP BY EARLY AFTERNOON AT BOTH COASTS. WINDS WILL SLOWLY DIMINISH AFTER SUNSET TO AROUND 5 KT. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 81 68 80 69 / - - 10 20 FORT LAUDERDALE 82 71 81 71 / 10 - 10 0 MIAMI 83 70 81 70 / 20 - 10 0 NAPLES 80 64 81 66 / - - 10 - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...85/AG AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
745 AM EDT TUE APR 2 2013 .UPDATE... FOR THE SHORT TERM...DENSE FOG CONTINUES TO AFFECT MOST OF THE SOUTH FLORIDA PENINSULA. THE ONLY TERMINALS NOT CURRENTLY AFFECTED WITH IFR VISIBILITY RESTRICTIONS ARE KMIA AND KOPF...BUT THESE TERMINALS COULD EXPERIENCE BRIEF PERIODS OF MIST AND/OR FOG OVER THE NEXT HOUR OR SO WITH SUB-VFR VIS RESTRICTIONS AND WILL AMEND AS NECESSARY. OTHERWISE...BY MID MORNING AND THROUGH THE AFTERNOON MAINLY VFR CONDITIONS EXPECTED ALL TERMINALS. WITH LIGHT VARIABLE FLOW THIS MORNING...THE WEST AND EAST COAST SEA BREEZES ARE EXPECTED TO FORM TODAY. 60 && .PREV DISCUSSION... /ISSUED 647 AM EDT TUE APR 2 2013/ UPDATE... SHORT TERM MODELS CONTINUE TO INDICATE THE POSSIBILITY OF AN AFTERNOON SHOWER IN THE INTERIOR PORTION OF THE STATE LATER THIS AFTERNOON. THE MAIN FOCUS WILL BE THE CONVERGENCE OF THE SEA BREEZE. CONFIDENCE IS STILL LOW, BUT FEEL THERE IS ENOUGH OF A CHANCE TO PUT A MENTION IN THE FORECAST FOR TODAY. PREV DISCUSSION... /ISSUED 447 AM EDT TUE APR 2 2013/ DISCUSSION... THE WEATHER FOR THE MOST PART IS QUIET. THERE IS SOME DENSE FOG IN THE WESTERN HALF OF THE FORECAST AREA, AND SOME LOCALIZED FOG NEAR TAMIAMI. SO, A DENSE FOG ADVISORY IS IN PLACE FOR PORTIONS OF SOUTH FLORIDA. THIS FOG SHOULD BURN OFF WITHIN A COUPLE OF HOURS AFTER SUNRISE. OTHERWISE, HIGH PRESSURE IS BUILDING IN TODAY. AREAS IN THE INTERIOR PORTIONS OF THE STATE WILL SEE HIGH TEMPERATURES IN THE MID TO UPPER 90S. COASTAL AREAS WILL SEE HIGHS IN THE LOW TO MID 80S. THERE SHOULD BE A DECENT SEA BREEZE TO DEVELOP TODAY. WITH SOME MOISTURE, WILL HAVE TO WATCH FOR INDICATIONS THAT SOME SHOWERS MAY DEVELOP IN THE INTERIOR, ESPECIALLY IF THERE IS ANY SEA BREEZE CONVERGENCE. NAM MODEL SOUNDINGS ARE SHOWING A GOOD CAP BETWEEN 500 AND 600 MB. THE HRRR IS HINTING THAT SOMETHING MAY DEVELOP, BUT IT IS AT THE END OF ITS MODEL RUN AND WOULD LIKE TO SEE WHAT IT DOES WITH THIS BEFORE PUTTING ANYTHING IN THE FORECAST FOR THIS AFTERNOON. HAVE KEPT POPS JUST BELOW SLIGHT CHC FOR THE INTERIOR FOR NOW. BY WEDNESDAY, A DEVELOPING LOW OVER THE WESTERN GULF OF MEXICO WILL CAUSE THE DEVELOPMENT OF A WARM FRONT ACROSS NORTH FLORIDA. THIS WILL ALLOW FOR A SOUTHEASTERLY FLOW, WHICH WILL HAVE SOME LIFT. THIS COULD ALLOW SOME SHOWERS TO DEVELOP ALONG THE BORDER WITH CENTRAL FLORIDA. HAVE KEPT SLIGHT CHANCE POPS IN FOR THAT AREA INTO THE EVENING HOURS. SPC DOES OUTLOOK THE AREA FOR A GENERAL THUNDERSTORM, BUT THERE IS BETTER 500MB VORTICITY ADVECTION TO THE NORTH, OVER CENTRAL FLORIDA. SO, KEPT THUNDERSTORMS OUT OF THE FORECAST FOR WEDNESDAY AFTERNOON WITH THIS FORECAST ISSUANCE. THE LOW, THAT CAUSED THE WARM FRONT, WILL QUICKLY STRENGTHEN AND MOVE NORTHEAST OVER THE FLORIDA PANHANDLE BY FRIDAY MORNING. THE ASSOCIATED COLD FRONT WILL MAKE ITS WAY ACROSS THE GULF AND WILL FIRST IMPACT CENTRAL FLORIDA. MODELS ARE STILL IN PRETTY GOOD AGREEMENT WITH THE STRENGTH, PLACEMENT, AND TIMING OF THE LOW, WITH A FEW MINOR DISCREPANCIES. THEY SHOW THE SOUTH FLORIDA COULD SEE SOME SHOWER ACTIVITY MOVING INTO THE AREA BY 12Z FRIDAY. THERE ARE INDICATIONS THAT A PRE-FRONTAL TROUGH WILL MOVE ACROSS THE AREA BY 18Z AND THEN THE MAIN FRONT WILL PUSH THROUGH SOMETIME AROUND 00Z SATURDAY. THERE IS A STRONG 500MB TROUGH/LOW, DEPENDING ON WHICH MODEL YOU LOOK AT, ASSOCIATED WITH THIS SYSTEM. THIS WILL HELP TO DEVELOP SOME HEAVIER SHOWERS. THE MAIN QUESTION IS THE THREAT OF THUNDERSTORMS. CURRENTLY, IT IS DIFFICULT TO TELL HOW HIGH THE PROBABILITY OF THUNDERSTORMS WILL BE. THE REASON IS THAT THE ATMOSPHERE COULD GET MIXED WELL BY THE PRE-FRONTAL TROUGH AND KEEP THE SKIES CLOUDY, REDUCING DAYTIME HEATING. THIS COULD REDUCE THE POTENTIAL, BUT DONT THINK ELIMINATE IT. HAVE KEPT HIGH CHC POPS IN FOR FRIDAY AND EVEN MENTION A SLIGHT CHANCE FOR TSTMS LATE THURSDAY NIGHT. IF THE ATMOSPHERE IS NOT TOO MIXED EARLY ON, THERE COULD BE A DECENT COVERAGE OF STORMS, AND SOME OF THOSE COULD BECOME STRONG. BUT, IT IS STILL TOO FAR OUT TOO MAKE ANY REAL ASSUMPTIONS. SO WILL KEEP IT SIMPLE WITH A CHC OF SHOWERS AND TSTMS FOR NOW. BEHIND THIS FRONT, TEMPERATURES ARE NOT GOING TO BE TOO GREATLY AFFECTED AND HIGH PRESSURE WILL BUILD IN TO BRING QUIET WEATHER FOR THE WEEKEND AND THE BEGINNING OF NEXT WEEK. CURRENTLY LOOKING AT MID TO UPPER 70S FOR THE COASTAL AREAS TO LOW 80S IN THE INTERIOR PORTIONS ON SATURDAY, WITH HIGH A FEW DEGREES HIGHER ON SUNDAY. MARINE... HIGH PRESSURE WILL BUILD IN TODAY. THIS WILL KEEP THE WEATHER QUIET OVER THE GULF AND ATLANTIC WATERS FOR TODAY THROUGH TOMORROW MORNING. AN APPROACHING SYSTEM WILL BRING A CHANCE FOR SOME SHOWERS TO THE AREA AS EARLY AS WEDNESDAY LATE AFTERNOON. FIRE WEATHER... FOG IS THE MAIN FIRE WEATHER CONCERN THIS MORNING. SOME OF THE AREAS ARE DENSE, AND MAYBE MORE SO DUE TO THE SMOKE FROM THE HUCKABEE FIRE IN COLLIER COUNTY. CONDITIONS SHOULD IMPROVE WITHIN A COUPLE OF HOURS AFTER SUNRISE. HIGH PRESSURE WILL BUILD IN TODAY AND HIGH TEMPERATURES WILL FLIRT WITH 90 DEGREES IN THE INTERIOR. THIS WILL LIKELY ALLOW A SEA BREEZE TO DEVELOP THIS AFTERNOON. CURRENT MODELS DO SHOW THE SEA BREEZES CONVERGING OVER THE CENTRAL PART OF THE STATE, QUITE POSSIBLY NEAR THE HUCKABEE FIRE. THIS COULD LEAD TO BETTER INSTABILITY IN THE VICINITY OF THE FIRE. THERE IS ALSO A SMALL POSSIBILITY OF SOME SHOWERS DEVELOPING IN THE AREA THEY CONVERGE, BUT TOO EARLY TO TELL. A LOW WILL BEGIN TO DEVELOP IN THE WESTERN GULF TODAY AND A WARM FRONT WILL SET UP OVER NORTH FLORIDA. THIS COULD ALLOW SOME SHOWERS TO BEGIN TO DEVELOP AS FAR SOUTH AS HENDRY/INTERIOR COLLIER COUNTIES TOMORROW AFTERNOON. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE AREA FRIDAY, BRINGING SHOWERS AND POSSIBLY THUNDERSTORMS TO THE AREA BEGINNING EARLY FRIDAY MORNING, THROUGH FRIDAY EVENING. PREV DISCUSSION... /ISSUED 138 AM EDT TUE APR 2 2013/ AVIATION... FOG WAS BEGINNING TO DEVELOP ACROSS THE INTERIOR AND TOWARDS KAPF EARLY THIS MORNING. MVFR CONDITIONS ARE EXPECTED TO DEVELOP OVER THE NEXT FEW HOURS THROUGH 14Z. IFR CONDITIONS COULD BRIEFLY OCCUR AT KAPF. SEA FOG IS POSSIBLE TO THE WEST OF KAPF OVER THE GULF TODAY AS WELL. LIGHT WINDS WILL CONTINUE OVERNIGHT. SEA BREEZE BOUNDARIES ARE EXPECTED TO DEVELOP BY EARLY AFTERNOON AT BOTH COASTS. WINDS WILL SLOWLY DIMINISH AFTER SUNSET TO AROUND 5 KT. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 81 68 80 69 / - - 10 20 FORT LAUDERDALE 82 71 81 71 / 10 - 10 0 MIAMI 83 70 81 70 / 20 - 10 0 NAPLES 80 64 81 66 / - - 10 - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR COASTAL COLLIER-FAR SOUTH MIAMI DADE-GLADES-HENDRY-INLAND BROWARD- INLAND COLLIER-INLAND MIAMI DADE-INLAND PALM BEACH-MAINLAND MONROE-METRO PALM BEACH. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...85/AG AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
647 AM EDT TUE APR 2 2013 .UPDATE... SHORT TERM MODELS CONTINUE TO INDICATE THE POSSIBILITY OF AN AFTERNOON SHOWER IN THE INTERIOR PORTION OF THE STATE LATER THIS AFTERNOON. THE MAIN FOCUS WILL BE THE CONVERGENCE OF THE SEA BREEZE. CONFIDENCE IS STILL LOW, BUT FEEL THERE IS ENOUGH OF A CHANCE TO PUT A MENTION IN THE FORECAST FOR TODAY. && .PREV DISCUSSION... /ISSUED 447 AM EDT TUE APR 2 2013/ DISCUSSION... THE WEATHER FOR THE MOST PART IS QUIET. THERE IS SOME DENSE FOG IN THE WESTERN HALF OF THE FORECAST AREA, AND SOME LOCALIZED FOG NEAR TAMIAMI. SO, A DENSE FOG ADVISORY IS IN PLACE FOR PORTIONS OF SOUTH FLORIDA. THIS FOG SHOULD BURN OFF WITHIN A COUPLE OF HOURS AFTER SUNRISE. OTHERWISE, HIGH PRESSURE IS BUILDING IN TODAY. AREAS IN THE INTERIOR PORTIONS OF THE STATE WILL SEE HIGH TEMPERATURES IN THE MID TO UPPER 90S. COASTAL AREAS WILL SEE HIGHS IN THE LOW TO MID 80S. THERE SHOULD BE A DECENT SEA BREEZE TO DEVELOP TODAY. WITH SOME MOISTURE, WILL HAVE TO WATCH FOR INDICATIONS THAT SOME SHOWERS MAY DEVELOP IN THE INTERIOR, ESPECIALLY IF THERE IS ANY SEA BREEZE CONVERGENCE. NAM MODEL SOUNDINGS ARE SHOWING A GOOD CAP BETWEEN 500 AND 600 MB. THE HRRR IS HINTING THAT SOMETHING MAY DEVELOP, BUT IT IS AT THE END OF ITS MODEL RUN AND WOULD LIKE TO SEE WHAT IT DOES WITH THIS BEFORE PUTTING ANYTHING IN THE FORECAST FOR THIS AFTERNOON. HAVE KEPT POPS JUST BELOW SLIGHT CHC FOR THE INTERIOR FOR NOW. BY WEDNESDAY, A DEVELOPING LOW OVER THE WESTERN GULF OF MEXICO WILL CAUSE THE DEVELOPMENT OF A WARM FRONT ACROSS NORTH FLORIDA. THIS WILL ALLOW FOR A SOUTHEASTERLY FLOW, WHICH WILL HAVE SOME LIFT. THIS COULD ALLOW SOME SHOWERS TO DEVELOP ALONG THE BORDER WITH CENTRAL FLORIDA. HAVE KEPT SLIGHT CHANCE POPS IN FOR THAT AREA INTO THE EVENING HOURS. SPC DOES OUTLOOK THE AREA FOR A GENERAL THUNDERSTORM, BUT THERE IS BETTER 500MB VORTICITY ADVECTION TO THE NORTH, OVER CENTRAL FLORIDA. SO, KEPT THUNDERSTORMS OUT OF THE FORECAST FOR WEDNESDAY AFTERNOON WITH THIS FORECAST ISSUANCE. THE LOW, THAT CAUSED THE WARM FRONT, WILL QUICKLY STRENGTHEN AND MOVE NORTHEAST OVER THE FLORIDA PANHANDLE BY FRIDAY MORNING. THE ASSOCIATED COLD FRONT WILL MAKE ITS WAY ACROSS THE GULF AND WILL FIRST IMPACT CENTRAL FLORIDA. MODELS ARE STILL IN PRETTY GOOD AGREEMENT WITH THE STRENGTH, PLACEMENT, AND TIMING OF THE LOW, WITH A FEW MINOR DISCREPANCIES. THEY SHOW THE SOUTH FLORIDA COULD SEE SOME SHOWER ACTIVITY MOVING INTO THE AREA BY 12Z FRIDAY. THERE ARE INDICATIONS THAT A PRE-FRONTAL TROUGH WILL MOVE ACROSS THE AREA BY 18Z AND THEN THE MAIN FRONT WILL PUSH THROUGH SOMETIME AROUND 00Z SATURDAY. THERE IS A STRONG 500MB TROUGH/LOW, DEPENDING ON WHICH MODEL YOU LOOK AT, ASSOCIATED WITH THIS SYSTEM. THIS WILL HELP TO DEVELOP SOME HEAVIER SHOWERS. THE MAIN QUESTION IS THE THREAT OF THUNDERSTORMS. CURRENTLY, IT IS DIFFICULT TO TELL HOW HIGH THE PROBABILITY OF THUNDERSTORMS WILL BE. THE REASON IS THAT THE ATMOSPHERE COULD GET MIXED WELL BY THE PRE-FRONTAL TROUGH AND KEEP THE SKIES CLOUDY, REDUCING DAYTIME HEATING. THIS COULD REDUCE THE POTENTIAL, BUT DONT THINK ELIMINATE IT. HAVE KEPT HIGH CHC POPS IN FOR FRIDAY AND EVEN MENTION A SLIGHT CHANCE FOR TSTMS LATE THURSDAY NIGHT. IF THE ATMOSPHERE IS NOT TOO MIXED EARLY ON, THERE COULD BE A DECENT COVERAGE OF STORMS, AND SOME OF THOSE COULD BECOME STRONG. BUT, IT IS STILL TOO FAR OUT TOO MAKE ANY REAL ASSUMPTIONS. SO WILL KEEP IT SIMPLE WITH A CHC OF SHOWERS AND TSTMS FOR NOW. BEHIND THIS FRONT, TEMPERATURES ARE NOT GOING TO BE TOO GREATLY AFFECTED AND HIGH PRESSURE WILL BUILD IN TO BRING QUIET WEATHER FOR THE WEEKEND AND THE BEGINNING OF NEXT WEEK. CURRENTLY LOOKING AT MID TO UPPER 70S FOR THE COASTAL AREAS TO LOW 80S IN THE INTERIOR PORTIONS ON SATURDAY, WITH HIGH A FEW DEGREES HIGHER ON SUNDAY. MARINE... HIGH PRESSURE WILL BUILD IN TODAY. THIS WILL KEEP THE WEATHER QUIET OVER THE GULF AND ATLANTIC WATERS FOR TODAY THROUGH TOMORROW MORNING. AN APPROACHING SYSTEM WILL BRING A CHANCE FOR SOME SHOWERS TO THE AREA AS EARLY AS WEDNESDAY LATE AFTERNOON. FIRE WEATHER... FOG IS THE MAIN FIRE WEATHER CONCERN THIS MORNING. SOME OF THE AREAS ARE DENSE, AND MAYBE MORE SO DUE TO THE SMOKE FROM THE HUCKABEE FIRE IN COLLIER COUNTY. CONDITIONS SHOULD IMPROVE WITHIN A COUPLE OF HOURS AFTER SUNRISE. HIGH PRESSURE WILL BUILD IN TODAY AND HIGH TEMPERATURES WILL FLIRT WITH 90 DEGREES IN THE INTERIOR. THIS WILL LIKELY ALLOW A SEA BREEZE TO DEVELOP THIS AFTERNOON. CURRENT MODELS DO SHOW THE SEA BREEZES CONVERGING OVER THE CENTRAL PART OF THE STATE, QUITE POSSIBLY NEAR THE HUCKABEE FIRE. THIS COULD LEAD TO BETTER INSTABILITY IN THE VICINITY OF THE FIRE. THERE IS ALSO A SMALL POSSIBILITY OF SOME SHOWERS DEVELOPING IN THE AREA THEY CONVERGE, BUT TOO EARLY TO TELL. A LOW WILL BEGIN TO DEVELOP IN THE WESTERN GULF TODAY AND A WARM FRONT WILL SET UP OVER NORTH FLORIDA. THIS COULD ALLOW SOME SHOWERS TO BEGIN TO DEVELOP AS FAR SOUTH AS HENDRY/INTERIOR COLLIER COUNTIES TOMORROW AFTERNOON. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE AREA FRIDAY, BRINGING SHOWERS AND POSSIBLY THUNDERSTORMS TO THE AREA BEGINNING EARLY FRIDAY MORNING, THROUGH FRIDAY EVENING. PREV DISCUSSION... /ISSUED 138 AM EDT TUE APR 2 2013/ AVIATION... FOG WAS BEGINNING TO DEVELOP ACROSS THE INTERIOR AND TOWARDS KAPF EARLY THIS MORNING. MVFR CONDITIONS ARE EXPECTED TO DEVELOP OVER THE NEXT FEW HOURS THROUGH 14Z. IFR CONDITIONS COULD BRIEFLY OCCUR AT KAPF. SEA FOG IS POSSIBLE TO THE WEST OF KAPF OVER THE GULF TODAY AS WELL. LIGHT WINDS WILL CONTINUE OVERNIGHT. SEA BREEZE BOUNDARIES ARE EXPECTED TO DEVELOP BY EARLY AFTERNOON AT BOTH COASTS. WINDS WILL SLOWLY DIMINISH AFTER SUNSET TO AROUND 5 KT. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 81 68 80 69 / - - 10 20 FORT LAUDERDALE 82 71 81 71 / 10 - 10 0 MIAMI 83 70 81 70 / 20 - 10 0 NAPLES 80 64 81 66 / - - 10 - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR COASTAL COLLIER-FAR SOUTH MIAMI DADE-GLADES-HENDRY-INLAND BROWARD- INLAND COLLIER-INLAND MIAMI DADE-INLAND PALM BEACH-MAINLAND MONROE-METRO PALM BEACH. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...13/SI AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
447 AM EDT TUE APR 2 2013 .DISCUSSION... THE WEATHER FOR THE MOST PART IS QUIET. THERE IS SOME DENSE FOG IN THE WESTERN HALF OF THE FORECAST AREA, AND SOME LOCALIZED FOG NEAR TAMIAMI. SO, A DENSE FOG ADVISORY IS IN PLACE FOR PORTIONS OF SOUTH FLORIDA. THIS FOG SHOULD BURN OFF WITHIN A COUPLE OF HOURS AFTER SUNRISE. OTHERWISE, HIGH PRESSURE IS BUILDING IN TODAY. AREAS IN THE INTERIOR PORTIONS OF THE STATE WILL SEE HIGH TEMPERATURES IN THE MID TO UPPER 90S. COASTAL AREAS WILL SEE HIGHS IN THE LOW TO MID 80S. THERE SHOULD BE A DECENT SEA BREEZE TO DEVELOP TODAY. WITH SOME MOISTURE, WILL HAVE TO WATCH FOR INDICATIONS THAT SOME SHOWERS MAY DEVELOP IN THE INTERIOR, ESPECIALLY IF THERE IS ANY SEA BREEZE CONVERGENCE. NAM MODEL SOUNDINGS ARE SHOWING A GOOD CAP BETWEEN 500 AND 600 MB. THE HRRR IS HINTING THAT SOMETHING MAY DEVELOP, BUT IT IS AT THE END OF ITS MODEL RUN AND WOULD LIKE TO SEE WHAT IT DOES WITH THIS BEFORE PUTTING ANYTHING IN THE FORECAST FOR THIS AFTERNOON. HAVE KEPT POPS JUST BELOW SLIGHT CHC FOR THE INTERIOR FOR NOW. BY WEDNESDAY, A DEVELOPING LOW OVER THE WESTERN GULF OF MEXICO WILL CAUSE THE DEVELOPMENT OF A WARM FRONT ACROSS NORTH FLORIDA. THIS WILL ALLOW FOR A SOUTHEASTERLY FLOW, WHICH WILL HAVE SOME LIFT. THIS COULD ALLOW SOME SHOWERS TO DEVELOP ALONG THE BORDER WITH CENTRAL FLORIDA. HAVE KEPT SLIGHT CHANCE POPS IN FOR THAT AREA INTO THE EVENING HOURS. SPC DOES OUTLOOK THE AREA FOR A GENERAL THUNDERSTORM, BUT THERE IS BETTER 500MB VORTICITY ADVECTION TO THE NORTH, OVER CENTRAL FLORIDA. SO, KEPT THUNDERSTORMS OUT OF THE FORECAST FOR WEDNESDAY AFTERNOON WITH THIS FORECAST ISSUANCE. THE LOW, THAT CAUSED THE WARM FRONT, WILL QUICKLY STRENGTHEN AND MOVE NORTHEAST OVER THE FLORIDA PANHANDLE BY FRIDAY MORNING. THE ASSOCIATED COLD FRONT WILL MAKE ITS WAY ACROSS THE GULF AND WILL FIRST IMPACT CENTRAL FLORIDA. MODELS ARE STILL IN PRETTY GOOD AGREEMENT WITH THE STRENGTH, PLACEMENT, AND TIMING OF THE LOW, WITH A FEW MINOR DISCREPANCIES. THEY SHOW THE SOUTH FLORIDA COULD SEE SOME SHOWER ACTIVITY MOVING INTO THE AREA BY 12Z FRIDAY. THERE ARE INDICATIONS THAT A PRE-FRONTAL TROUGH WILL MOVE ACROSS THE AREA BY 18Z AND THEN THE MAIN FRONT WILL PUSH THROUGH SOMETIME AROUND 00Z SATURDAY. THERE IS A STRONG 500MB TROUGH/LOW, DEPENDING ON WHICH MODEL YOU LOOK AT, ASSOCIATED WITH THIS SYSTEM. THIS WILL HELP TO DEVELOP SOME HEAVIER SHOWERS. THE MAIN QUESTION IS THE THREAT OF THUNDERSTORMS. CURRENTLY, IT IS DIFFICULT TO TELL HOW HIGH THE PROBABILITY OF THUNDERSTORMS WILL BE. THE REASON IS THAT THE ATMOSPHERE COULD GET MIXED WELL BY THE PRE-FRONTAL TROUGH AND KEEP THE SKIES CLOUDY, REDUCING DAYTIME HEATING. THIS COULD REDUCE THE POTENTIAL, BUT DONT THINK ELIMINATE IT. HAVE KEPT HIGH CHC POPS IN FOR FRIDAY AND EVEN MENTION A SLIGHT CHANCE FOR TSTMS LATE THURSDAY NIGHT. IF THE ATMOSPHERE IS NOT TOO MIXED EARLY ON, THERE COULD BE A DECENT COVERAGE OF STORMS, AND SOME OF THOSE COULD BECOME STRONG. BUT, IT IS STILL TOO FAR OUT TOO MAKE ANY REAL ASSUMPTIONS. SO WILL KEEP IT SIMPLE WITH A CHC OF SHOWERS AND TSTMS FOR NOW. BEHIND THIS FRONT, TEMPERATURES ARE NOT GOING TO BE TOO GREATLY AFFECTED AND HIGH PRESSURE WILL BUILD IN TO BRING QUIET WEATHER FOR THE WEEKEND AND THE BEGINNING OF NEXT WEEK. CURRENTLY LOOKING AT MID TO UPPER 70S FOR THE COASTAL AREAS TO LOW 80S IN THE INTERIOR PORTIONS ON SATURDAY, WITH HIGH A FEW DEGREES HIGHER ON SUNDAY. && .MARINE... HIGH PRESSURE WILL BUILD IN TODAY. THIS WILL KEEP THE WEATHER QUIET OVER THE GULF AND ATLANTIC WATERS FOR TODAY THROUGH TOMORROW MORNING. AN APPROACHING SYSTEM WILL BRING A CHANCE FOR SOME SHOWERS TO THE AREA AS EARLY AS WEDNESDAY LATE AFTERNOON. && .FIRE WEATHER... FOG IS THE MAIN FIRE WEATHER CONCERN THIS MORNING. SOME OF THE AREAS ARE DENSE, AND MAYBE MORE SO DUE TO THE SMOKE FROM THE HUCKABEE FIRE IN COLLIER COUNTY. CONDITIONS SHOULD IMPROVE WITHIN A COUPLE OF HOURS AFTER SUNRISE. HIGH PRESSURE WILL BUILD IN TODAY AND HIGH TEMPERATURES WILL FLIRT WITH 90 DEGREES IN THE INTERIOR. THIS WILL LIKELY ALLOW A SEA BREEZE TO DEVELOP THIS AFTERNOON. CURRENT MODELS DO SHOW THE SEA BREEZES CONVERGING OVER THE CENTRAL PART OF THE STATE, QUITE POSSIBLY NEAR THE HUCKABEE FIRE. THIS COULD LEAD TO BETTER INSTABILITY IN THE VICINITY OF THE FIRE. THERE IS ALSO A SMALL POSSIBILITY OF SOME SHOWERS DEVELOPING IN THE AREA THEY CONVERGE, BUT TOO EARLY TO TELL. A LOW WILL BEGIN TO DEVELOP IN THE WESTERN GULF TODAY AND A WARM FRONT WILL SET UP OVER NORTH FLORIDA. THIS COULD ALLOW SOME SHOWERS TO BEGIN TO DEVELOP AS FAR SOUTH AS HENDRY/INTERIOR COLLIER COUNTIES TOMORROW AFTERNOON. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE AREA FRIDAY, BRINGING SHOWERS AND POSSIBLY THUNDERSTORMS TO THE AREA BEGINNING EARLY FRIDAY MORNING, THROUGH FRIDAY EVENING. && .PREV DISCUSSION... /ISSUED 138 AM EDT TUE APR 2 2013/ AVIATION... FOG WAS BEGINNING TO DEVELOP ACROSS THE INTERIOR AND TOWARDS KAPF EARLY THIS MORNING. MVFR CONDITIONS ARE EXPECTED TO DEVELOP OVER THE NEXT FEW HOURS THROUGH 14Z. IFR CONDITIONS COULD BRIEFLY OCCUR AT KAPF. SEA FOG IS POSSIBLE TO THE WEST OF KAPF OVER THE GULF TODAY AS WELL. LIGHT WINDS WILL CONTINUE OVERNIGHT. SEA BREEZE BOUNDARIES ARE EXPECTED TO DEVELOP BY EARLY AFTERNOON AT BOTH COASTS. WINDS WILL SLOWLY DIMINISH AFTER SUNSET TO AROUND 5 KT. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 81 68 80 69 / - - 10 20 FORT LAUDERDALE 82 71 81 71 / - - 10 0 MIAMI 83 70 81 70 / - - 10 0 NAPLES 80 64 81 66 / - - 10 - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR GLADES-HENDRY- INLAND BROWARD-INLAND COLLIER-INLAND MIAMI DADE-INLAND PALM BEACH. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...13/SI AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION...UPDATE
NWS PEACHTREE CITY GA
140 AM EDT TUE APR 2 2013 .UPDATE... TWO WEAK BOUNDARIES ACROSS THE CWFA THIS EVENING...BOTH WEAK COLD FRONTS. THE FIRST FRONT IS ACROSS NORTHERN GA AND THE SECOND IS ACROSS THE SOUTHERN CWFA. NO REAL MOISTURE ASSOCIATED WITH EITHER OF THESE FEATURES OTHER THAN SOME CU...SO HAVE REMOVED THE MENTION OF POPS. ANY SCT CU SHOULD ALSO DISSIPATE WITH SUNSET. TWEAKED HOURLY TEMPS A BIT...THEY WERE NOT FALLING OFF AS FAST AS FORECAST. ADJUSTED THE MIN TEMPS A FEW HOURS...WITH THE METRO AREA A COUPLE OF DEGREES WARMER. && .PREV DISCUSSION... /ISSUED 350 PM EDT MON APR 1 2013/ ..BRIEF DRY PERIOD BEFORE RAIN RETURNS MID WEEK... SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... LATEST SURFACE ANALYSIS SHOWS SEMI PERMANENT SURFACE TROUGH FROM JUST SOUTH OF ATHENS THROUGH COLUMBUS. ALONG AND SOUTH OF THIS FEATURE MOISTURE SURFACE CONVERGENCE HAS RESULTED IN SCATTERED TO BROKEN CU DEVELOPMENT BUT SHOWER ACTIVITY HAS REMAINED OUTSIDE OF THE FORECAST AREA. FURTHER NORTH...SURFACE FRONT CONTINUES TO SAG INTO NORTH GA WITH MOISTURE POOLING ALONG ITS LEADING EDGE AS WELL AND ADDITIONAL CLOUD DEVELOPMENT THE RESULT. THIS SHOULD REMAIN JUST CLOUDS WITH NO PRECIP FOR THIS EVENING AS MAIN FOCUS WILL BE ON SOUTHERN TROUGH AND IT AFFECTS ON CENTRAL GEORGIA. LOOKING AT THE LATEST RAP ANALYSIS OF CAPE IN THIS VICINITY AND WE SEE 500 J/KG TO 1000 J/KG OF AVAILABLE ENERGY...SLIGHTLY HIGHER THAN MODEL PROJECTIONS. STILL LOOKING AT 500MN TEMPS IN THE VERY COLD RANGE OF -17C IN THIS AREA SO ANY SUSTAINED UPDRAFTS WILL BE CAPABLE OF PRODUCING LARGE HAIL. ACTIVITY WILL SHIFT EAST QUICKLY THIS EVENING WITH CLEARING CONDITIONS TAKING PLACE. STILL SOME GRADIENT IN PLACE ACROSS THE AREA WHICH WILL PREVENT OPTIMUM RADIATIONAL COOLING CONDITIONS. WENT WITH A MAV/MET BLEND FOR THE OVERNIGHT TEMPS WHICH WILL BE TRICKY TO THE SOUTH BASED ON HOW FAST CLOUDS CLEAR. SURFACE FRONT LOOKS TO STALL ACROSS NORTH GEORGIA TUESDAY AND IMPULSES OF ENERGY BEGIN TO ROUND PERIPHERY OF EAST COAST TROUGH. THIS SHOULD ALLOW A FEW LIGHT SHOWERS TO DEVELOP ACROSS EXTREME NORTH GEORGIA AND HAVE INCLUDED IN THIS GRID PACKAGE. AS HIGH BRIDGES ACROSS THROUGH TUESDAY NIGHT...MAY SEE FRONT SAG FURTHER SOUTH AND TAKE 20 POPS ALONG WITH IT INTO THE REMAINDER OF NORTH GEORGIA. DEESE LONG TERM /WEDNESDAY THROUGH MONDAY/... MAIN CONCERN FOR THE EXTENDED REMAINS THE SYSTEM MOVING THROUGH THE STATE ON WEDNESDAY INTO THE END OF THE WORK WEEK. DISCREPANCIES STILL REMAIN BETWEEN THE EURO AND GFS AS FAR AS TIMING OF THE SYSTEM LEAVING THE CWA. THE 12Z MODELS ARE STRIKINGLY SIMILAR TO THEIR 00Z COUNTERPARTS. AS SUCH...WAS NOT ABLE TO NAIL DOWN AN ACCURATE END TO THE RAIN THIS WEEK. ACCORDING TO HPC MODEL DISCUSSIONS THE EURO IS AN OUTLIER...MOVING THE SYSTEM FURTHER SOUTH AND IS SLOWER. THAT SAID THEY DECIDED TO WITH A BLEND BETWEEN THE 00Z EURO AND THE 06Z GEFS. WITH THIS MUCH UNCERTAINTY DECIDED TO ONLY CHANGE THE COVERAGE OF THUNDER ON WEDNESDAY AND LEAVE THE REST OF THE FORECAST ALONE. DID LOWER TEMPS ON THURSDAY AS A PSEUDO WEDGE BUILDS IN. CLOUDS AND RAIN IN ASSOCIATION WITH THIS WEDGE SHOULD HELP TO KEEP TEMPS LOW. HAVE INCLUDED PREVIOUS EXTENDED BELOW/ ARG LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... POTENTIAL FOR A HEAVY RAIN/SEVERE WEATHER EVENT SETTING UP IN THE THURSDAY TO THURSDAY NIGHT TIME FRAME. MODELS SIMILAR WITH SPREADING DEEPER MOISTURE INTO THE AREA LATE WEDNESDAY BUT THE MAIN PRECIP PERIOD LOOKS TO BE WEDNESDAY NIGHT THRU THURSDAY NIGHT. AN OVERRUNNING PATTERN WILL SET LATE WEDNESDAY/WEDNESDAY NIGHT WITH MODELS DEVELOPING A WARM FRONT ALONG THE GULF COAST. SURFACE LOW PRESSURE DEVELOPS OVER THE WESTERN GULF AND MOVES TO THE WESTERN FL PANHANDLE LATE THURSDAY AND THEN ACROSS CENTRAL TO S GA THURSDAY NIGHT/FRIDAY. THE GFS IS FASTER WITH THIS PROGRESSION THAN THE EUROPEAN. THIS TRACK COULD MOVE THE WARM FRONT INTO THE SE CWA AND GIVE POTENTIAL FOR SEVERE THUNDERSTORMS MAINLY THURSDAY NIGHT. IT WILL ALSO GIVE POTENTIAL FOR HEAVY RAIN ACROSS A LARGE PORTION OF EAST GEORGIA AND MODELS IN GENERAL ARE LESS GUN-OH WITH PRECIP AMOUNTS WITH A LARGE AREA OF 1-2 INCHES FORECAST. THE UPPER TROUGH MOVES ACROSS THE AREA ON FRIDAY AND THE GFS IS FASTER WITH THIS PROGRESSION THAN THE EUROPEAN. THE AIRMASS DRIES OUT FOR SATURDAY AND MOSTLY LIKELY SUNDAY WITH THE EUROPEAN INDICATING SOME MOISTURE ASSOCIATED WITH A SHORT WAVE ON SUNDAY...MOST SO FOR N GA. FOR NOW WILL KEEP THINGS DRY AND MONITOR THE PROGRESSION. A SHORT WAVE RIDGE BUILDS FOR MONDAY WITH THE EUROPEAN CONTINUING TO SHOW MORE MOISTURE SKIRTING OVER N GA THAN THE GFS. BDL AVIATION... 06Z UPDATE... VFR THROUGH THE FORECAST PERIOD. SOME SCT050-060 POSSIBLE DURING THE AFTERNOON. LIGHT NORTHWEST WINDS WILL CONTINUE UNTIL AROUND 12Z THEN A BRIEF PERIOD OF NORTH FLOW IS POSSIBLE DURING THE MORNING BUT PREDOMINATELY NORTHWEST DURING THE AFTERNOON. //ATL CONFIDENCE...06Z UPDATE... MEDIUM ON WIND SHIFT. HIGH ON REMAINING ELEMENTS. 41 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 42 69 41 64 / 10 10 20 20 ATLANTA 47 67 44 64 / 5 5 20 20 BLAIRSVILLE 37 58 35 63 / 10 10 20 20 CARTERSVILLE 41 65 40 64 / 5 10 20 20 COLUMBUS 51 75 50 70 / 5 5 5 30 GAINESVILLE 44 65 43 61 / 10 10 20 20 MACON 45 75 44 69 / 5 5 5 30 ROME 38 65 38 64 / 5 10 20 20 PEACHTREE CITY 40 70 42 65 / 5 5 20 30 VIDALIA 55 76 51 74 / 20 0 5 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
627 AM EDT TUE APR 2 2013 .SYNOPSIS... A COLD AIR MASS WILL REMAIN IN PLACE ACROSS THE REGION THROUGH WEDNESDAY. DISTURBANCES ROTATING AROUND AN EASTERN CANADIAN LOW WILL PRODUCE SNOW SHOWERS ACROSS NORTHERN AND WESTERN MAINE TODAY INTO TONIGHT THAT WILL BECOME SCATTERED WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... 0615AM UPDATE... VERY DRY AIR IS WORKING SOUTHWARD THROUGH THE FORECAST AREA THIS MORNING. ADJUSTED DEW POINTS DOWN AND WIND GUSTS UP IN LATEST UPDATE. ALSO ADDED CHANCE POPS FOR SNOW SHOWERS FOR BANGOR BY MIDDAY AS HRRR AND RUC ARE SHOWING A WEAK SURFACE TROUGH MOVING ACROSS THE AREA EARLY THIS AFTERNOON. ANOTHER TROUGH APPEARS IN NORTHERN MAINE LATE THIS AFTERNOON WITH THE CHANCE OF SOME BRIEF...HEAVIER SNOW SHOWERS IN AROOSTOOK. OTHERWISE...EXPECT A LOT OF WEAKER SNOW SHOWERS POPPING UP ACROSS THE FORECAST AREA THIS AFTERNOON. A COLD UPPER LOW WILL MOVE JUST NORTH OF THE FORECAST AREA THIS AFTERNOON. COLD AIR ALOFT COMBINED WITH H850 MOISTURE WILL PRODUCE INSTABILITY TO NEAR H700 THIS AFTERNOON AND EVENING. THE RESULTING SNOW SHOWERS WILL BE MOST LIKELY IN THE CROWN OF MAINE...BUT A FEW SHOWERS WILL OCCUR ALL THE WAY SOUTH TO THE COAST THIS AFTERNOON. THE MIXING ASSOCIATED WITH THIS INSTABILITY WILL PRODUCE A WINDY DAY WITH WEST WINDS GUSTING TO OVER 30 MPH. THE WELL MIXED ATMOSPHERE WILL PRODUCE A MIXTURE OF SUN AND CLOUDS BUT WILL GO WITH MOSTLY CLOUDY IN MOST ZONES THIS AFTERNOON. SOME LOCATIONS MAY RECEIVE MULTIPLE SNOW SHOWERS DURING THE COURSE OF THE AFTERNOON. TEMPERATURES WILL ONLY REACH THE UPPER 20S NORTH AND LOW 30S FOR BANGOR AND DOWN EAST. THE SNOW SHOWERS WILL CONTINUE INTO THE EVENING AND THEN SUBSIDENCE ALOFT WILL CREATE STRATOCUMULUS TONIGHT. THESE CLOUDS AND CONTINUED WINDS WILL ONLY ALLOW TEMPERATURES TO FALL TO THE MID TO UPPER TEENS NORTH AND LOW 20S FOR BANGOR AND DOWN EAST ZONES. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... A DEEP UPPER LOW ACROSS ERN CANADA WILL ROTATE OUT TO THE NW AND BEGIN TO GRADUALLY LOOSE ITS GRIP ON THE WEATHER ACROSS NRN NEW ENGLAND. THE AIR MASS WILL CONTINUE TO BE UNSEASONABLY COLD WITH AN 850 MB TEMP OF AROUND -17C AT 12Z WED WHICH IS ABOUT 2 STD DEV BELOW NORMAL FOR EARLY APR. THERE WILL STILL BE ENOUGH CYCLONIC FLOW ALOFT WHICH IS CONDUCIVE FOR MOISTURE AND WEAK DISTURBANCES TO ROTATE THROUGH AND PRODUCE SCATTERED SNOW SHOWERS ACROSS THE WESTERN MOUNTAINS AND FAR NORTHERN MAINE...ESPECIALLY SO ACROSS THE FAVORED UPSLOPE AREAS. TEMPS WILL REMAIN ABOUT 10 DEGREES BELOW NORMAL WITH HIGHS ONLY IN THE UPPER 20S TO LOW 30S NORTH WITH M/U 30S DOWNEAST. A SFC HIGH SLIDES SOUTH OF THE AREA THU AS A WEAK CLIPPER APPROACHES FROM THE WEST LATE IN THE DAY. TEMPERATURES THU PM WILL MODERATE BACK CLOSER TO 40 IN THE NORTH AND MID 40S DOWNEAST. CLOUDS WILL INCREASE ACROSS THE NORTH AHEAD OF THE CLIPPER SYSTEM. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE AFORE MENTIONED CLIPPER WASHES OUT ACROSS THE AREA FRI AS ATTENTION TURNS TO A SOUTHERN BRANCH LOW THAT MOVES OFF THE MID ATLANTIC COAST FRI PM. THE ECMWF HAS BEEN CONSISTENT IN HAVING A WEAKER AND LESS PHASED SYSTEM THAT PASSES FAR ENOUGH SOUTH OF THE AREA TO KEEP THE PRECIPITATION SHIED WELL OFFSHORE. THE GFS AND CANADIAN HAVE STRONGER AND MORE PHASED SOLUTIONS THAT WOULD BRING SOME RAIN OR MIXED PRECIPITATION CHANGING TO SNOW FOR DOWNEAST AREAS FRI NIGHT. THE 00Z RUNS OF THE GFS AND CANADIAN ARE A BIT FURTHER EAST WITH THE LOW WHEN COMPARED TO LAST NIGHTS RUNS. THE ONGOING FORECAST HAS THIS COVERED WELL WITH HIGH CHANCE POPS DOWNEAST FRI NIGHT. A RIDGE OF HIGH PRESSURE BRIEFLY BUILDS IN FROM THE WEST SAT AND IS QUICKLY FOLLOWED BY ANOTHER WEAK CLIPPER THAT MOVES IN FROM THE WEST SAT NIGHT AND SUN. YET ANOTHER SYSTEM APPROACHES FROM THE WEST/SOUTHWEST LATE MON WITH THE POTENTIAL FOR ANOTHER MIXED PRECIPITATION EVENT. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... NEAR TERM: MVFR CIGS EARLY THIS MORNING NORTH OF HOULTON. THESE CIGS WILL RISE TOWARDS 5000FT THIS AFTERNOON WITH WIDESPREAD SNOW SHOWERS UP TO 10000FT. STRONG WIND GUSTS AS HIGH AS 35 MPH ARE EXPECTED THIS AFTERNOON WITH A LOT OF LOW LEVEL TURBULENCE. VIS IN SNOW SHOWERS COULD DROP BRIEFLY TO IFR THIS AFTERNOON. SHORT TERM: MVFR AT TIMES AT THE NORTHERN TERMINALS INTO WED EVENING IN SCT -SHSN. OTHERWISE VFR THROUGH THU NIGHT. MVFR POSSIBLE FRI IN SCT -SHSN/SHRA. A COASTAL STORM MAY LOWER CONDITIONS TO IFR FRI NIGHT IN RN/SN AT KBHB AND KBGR. && .MARINE... NEAR TERM: SCA WILL CONTINUE WITH STRONG WEST WINDS GUSTING TO 35 KT AND SEAS IN THE SIX TO EIGHT FOOT RANGE. SHORT TERM: THE SCA WAS EXTENDED THROUGH 6 PM WED...AND SUBSEQUENT SHIFTS WILL LIKELY NEED TO EXTEND IT ONE MORE FORECAST PERIOD THROUGH WED NIGHT. THE WIND MAY DROP OFF FOR A TIME THU...BUT IS EXPECTED TO PICK UP AGAIN LATE IN THE DAY AHEAD OF AN APPROACHING FRONTAL BOUNDARY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR ANZ050>052. && $$ NEAR TERM...MCW SHORT TERM...CB LONG TERM...CB AVIATION...MCW MARINE...MCW/CB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
138 PM EDT TUE APR 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 520 AM EDT TUE APR 2 2013 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF OVER THE E HALF OF NAMERICA DOWNSTREAM OF RDG OVER WRN CANADA. CWA REMAINS DOMINATED BY COLD CYC NW FLOW IN THE WAKE OF SLOWLY DEPARTING CLOSED LO OVER WRN QUEBEC. ALTHOUGH H85 TEMPS RANGING FM -14C OVER THE W TO -16C OVER THE E AND INVRN BASE NEAR H8 ARE SUFFICIENTLY COLD/HI FOR LES EVEN IN THE ABSENCE OF ANY DYNAMIC FORCING...UPSTREAM 00Z INL/YPL RAOBS ARE SO DRY...WITH THE H925 DEWPT DEPRESSION 15C AT INL IN INVERTED V T/TD PROFILE...THAT THERE ONLY A FEW WEAK CLD BANDS OVER THE W HALF OF LK SUP STREAMING INTO THE WRN ZNS. WITH A LONGER FETCH OVER THE E HALF AND A WEAK SFC TROF PASSING THRU THIS AREA...MORE CLDS/SOME LES BANDS ARE EVIDENT STREAMING INTO THE CWA E OF MQT. BUT DRYNESS OF AIRMASS IS EVIDENT IN LO REFLECTIVITIES. LOOKING FARTHER UPSTREAM...THERE IS A FAIRLY VIGOROUS SHRTWV NEAR LK WINNIPEG DIGGING SEWD. BUT SINCE THE 00Z THE PAS MANITOBA RAOB IS ALSO QUITE DRY WITH INVERTED V T/TD PROFILE IN THE LLVLS...THERE ARE ONLY SOME PATCHY MID/HI CLDS IN THE PVA ASSOCIATED WITH THIS FEATURE. ANOTHER SHRTWV OVER HUDSON BAY IS DIVING SWD. EARLY THIS MRNG/TODAY...WITH NOCTURNAL COOLING EARLY THIS MRNG AND SOME ENHANCED LLVL CNVGC ALONG WEAK SFC TROF...EXPECT SCT-NMRS -SHSN TO IMPACT THE ERN ZNS THRU THIS MRNG. OVER THE W...THERE SHOULD BE LTL IF ANY LES OR EVEN LK CLDS THRU 09Z GIVEN THE UPSTREAM DRYNESS...BUT MODELS SHOW AREA OF DPVA/H85-5 QVECTOR CNVGC ASSOCIATED WITH SHRTWV DIGGING THRU MN IMPACTING THE FAR W BY 12Z. SUSPECT MORE CLDS/A FEW -SHSN MIGHT DVLP IN PRESENCE OF NOCTURNAL COOLING...BUT LLVL DRYNESS WL LIMIT COVERAGE/INTENSITY OF ANY SHSN THAT MIGHT POP UP. IF THERE IS ANY SHSN...THESE SHOULD DIMINISH ONCE THE FORCING PASSES TO THE S BY 15Z AND DAYTIME HEATING BEGINS TO DISRUPT THE LES PROCESS. LATE IN THE DAY...NEXT SHRTWV OVER HUDSON BAY IS PROGGED TO DIG INTO THE UPR LKS WITH ACCOMPANYING DPVA AND H85-5 QVECTOR CNVGC IMPACTING THE CWA. ALTHOUGH DAYTIME HEATING MIGHT ALSO DISRUPT THE LES OVER THE E HALF IN THE AFTN...THE ARRIVAL OF THIS FORCING MIGHT CAUSE AN UPTICK OF SHSN AGAIN TOWARD 00Z ESPECIALLY OVER THE E HALF CLOSER TO DEEPER MSTR/COLDER AIR. AS FOR TEMPS...PREFER TO TEND TOWARD THE HIER END OF GUIDANCE WITH A GOOD DEAL OF SUNSHINE...AT LEAST OVER THE W AND SCENTRAL. TNGT...SHRTWV DROPPING S INTO THE UPR LKS AND ACCOMPANYING DYNAMIC FORCING IS PROGGED TO CROSS THE ERN COUNTIES. WITH LOWER H85 TEMPS ARND -17C CLOSER TO THE CYC SIDE OF THE TRACK OF THIS DISTURBANCE AS WELL AS DEEPER MSTR/SOMEWHAT HIER INVRN SHOWN THERE ON FCST SDNGS... OPTED TO RAISE POPS INTO THE LIKELY RANGE NEAR LK SUP E OF MQT AS THESE EVENTS OCCUR DURING THE MORE FAVORABLE NOCTURNAL COOLING. EXPECT MUCH LESS IF ANY ACTIVITY OVER THE W ON THE ACYC SIDE OF THE SHRTWV PASSAGE AND WHERE FCST SNDGS SHOW MUCH DRIER AIR AND HIER H85 TEMPS/LOWER INVNR BASE. EXPECT THE LOWEST MIN TEMPS TOWARD THE LOWER END OF GUIDANCE OVER THE INTERIOR W UNDER THE DRIER AIR AND WHERE WINDS WL BE LIGHTER. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 520 AM EDT TUE APR 2 2013 LOOKS LIKE A PATTERN CHANGE IS IN THE OFFING OVER THE NEXT FEW WEEKS THAT WILL TRANSITION THE PERSISTENT BELOW NORMAL TEMP REGIME TOWARD AN ABOVE NORMAL ONE. THE AO AND NAO WHICH HAVE BEEN IN A PREVAILING NEGATIVE PHASE SINCE EARLY/MID FEB ARE BOTH FORECAST TO TREND TO THE POSITIVE PHASE...WITH THE AO BECOMING STRONGLY POSITIVE. THIS SUPPORTS A TREND TOWARD ABOVE NORMAL TEMPS HEADING INTO MID/LATE APRIL...BUT THIS DOESN`T PRECLUDE THE POTENTIAL FOR MORE WINTRY PCPN EVENTS BEFORE THE WARMER PATTERN SETS IN. THE PATTERN ALSO APPEARS TO BE SHIFTING TOWARD AN ACTIVE ONE OVER THE NEXT 2 WEEKS. INTO THE UPCOMING WEEKEND...FLOW WILL TREND PROGRESSIVE AND FLATTER WITH A COUPLE OF SHORTWAVES TO AFFECT THE UPPER LAKES...THE FIRST WED NIGHT/THU AND A SECOND MORE IMPORTANT WAVE SAT. EARLY NEXT WEEK...AN AMPLIFIED TROF WILL BE DEVELOPING OVER THE WRN CONUS...SIGNALING THE POTENTIAL FOR MORE SIGNIFICANT PCPN EVENTS NEXT WEEK FROM THE CNTRL/SRN PLAINS TO THE GREAT LAKES AS THE GULF OPENS UP. THIS COULD MEAN ONE OR MORE UNWELCOMED RAIN EVENTS ON A MELTING SNOWPACK WHICH IS STILL DEEP IN THE LAKE EFFECT AREAS OR MORE SNOW COULD STILL BE ADDED. IN RECENT DAYS...MEDIUM RANGE GUIDANCE HAS TONED DOWN THE WARMING NEXT WEEK...SO MORE SNOW IS STILL A REAL POSSIBILITY. BEGINNING WED...SFC HIGH PRES WILL QUICKLY SHIFT ACROSS THE WRN GREAT LAKES AHEAD OF THE FIRST SHORTWAVE THAT WILL BE TRACKING ACROSS SASKATCHEWAN/MANITOBA. IF ANY LIGHT LES IS LINGERING OVER THE ERN FCST AREA TO START THE DAY...IT WILL END QUICKLY IN THE MORNING. AFTER A PERIOD OF SUNSHINE...HIGH CLOUDS WILL BE ON THE INCREASE. SUNSHINE WILL SUPPORT A STRONG DIURNAL TEMP SPREAD. AFTER MORNING LOWS IN THE SINGLE DIGITS OVER THE INTERIOR W...TEMPS SHOULD REBOUND INTO THE UPPER 30S/LWR 40S. SHORTWAVE WILL MOVE ACROSS NRN ONTARIO WED NIGHT/THU MORNING. WITH STRONG DEEP LAYER FORCING/IMPRESSIVE 500MB HEIGHT FALLS (AROUND 200M/12HR) PASSING WELL TO THE N OF HERE...MAIN PCPN AREA WILL PASS TO THE N OF UPPER MI. NONETHELESS...50-80M HEIGHT FALLS AT 500MB... RIBBON OF MODEST DEEP LAYER FORCING PER QVECTORS AND ISENTROPIC ASCENT SUGGEST SOME PCPN POTENTIAL ACROSS THE FCST AREA. WITH ISENTROPIC ASCENT WEAKENING AS IT SHIFTS ACROSS THE UPPER LAKES... AND LOW-LEVEL DRY AIR TO OVERCOME INITIALLY...NOTHING MORE THAN LOW CHC POPS APPEAR WARRANTED ATTM. ALTHOUGH LOW-LEVEL TEMPS ARE JUST ABOVE 0C PRIOR TO POTENTIAL PCPN ARRIVING...EVAPORATIVE COOLING SHOULD BE SUFFICIENT SO THAT SNOW BECOMES THE MAIN PTYPE IN MOST AREAS. PCPN CHC WILL END W TO E THU MORNING WITH DRY WEATHER FOLLOWING THRU THU NIGHT/FRI AS SFC HIGH PRES RIDGE BUILDS SE INTO THE UPPER LAKES. 850MB TEMPS FALLING TO AROUND -12C THU NIGHT/FRI MORNING WILL BE AT THE THRESHOLD FOR LES. HOWEVER...SINCE LOW-LEVEL FLOW BECOMES MORE ANTICYCLONIC DURING THE NIGHT AND AIR MASS IS FAIRLY DRY IN THE LOW-LEVELS...WILL NOT INCLUDE ANY MENTION OF -SHSN. OVER THE W...FLOW IS MORE DIVERGENT...SO THERE MAY NOT EVEN BE MUCH IN THE WAY OF CLOUDS. OPTED TO GO BLO GUIDANCE THERE THU NIGHT AS WINDS WILL PROBABLY FALL OFF TO CALM AS HIGH PRES RIDGE NEARS. ALTHOUGH LOWERED MINS TO THE LOW/MID TEENS...TEMPS COULD EASILY FALL INTO THE SINGLE DIGITS. FRI NIGHT/SAT...ATTENTION TURNS TO THE SECOND MORE IMPORTANT SHORTWAVE TRACKING ACROSS THE NRN CONUS IN FLATTER FLOW REGIME. MEDIUM RANGE GUIDANCE IS MOVING TOWARD SLIGHTLY BETTER AGREEMENT WITH SYSTEM...BUT IMPORTANT DETAILS HAVE YET TO BE NARROWED DOWN. THE GFS WHICH HAS BEEN CONSISTENTLY FARTHER S HAS TRENDED A LITTLE FARTHER N WITH WAVE AND IS IN DECENT AGREEMENT WITH THE GLOBAL GEM. THE ECMWF HAS BEEN CONSISTENTLY FARTHER N. THE GFS TRACK LOOKS TO SUPPORT ALL SNOW FOR THE FCST AREA AS THE 850MB LOW TRACKS ALONG WI/UPPER MI BORDER AND 850MB TEMPS REMAIN BLO 0C AND 1000-850MB THICKNESS IS NO HIGHER THAN 1295M. THE GLOBAL GEM MOSTLY SUPPORTS ALL SNOW WITH A POSSIBLE CHANGEOVER TO RAIN S AND SE...BUT ITS SLOWER/MORE WRAPPED UP SYSTEM DOES NOT APPEAR TO FIT THE DEVELOPING FLATTER FLOW REGIME. HOWEVER...THE 00Z ECMWF ALSO TRENDED MUCH SLOWER AND SHARPER WITH SHORTWAVE...SO THIS MAY BE AN IMPORTANT TREND TO MONITOR IN FUTURE MODEL RUNS. THE FARTHER N ECMWF SUGGESTS MORE OF A MIXED PCPN EVENT WITH MORE SNOW THAN RAIN N AND MORE RAIN THAN SNOW S. THE HEAVIEST SWATH OF PCPN PASSES ACROSS NRN UPPER MI IN THE ECMWF...JUST S IN THE GFS AND CLIPS THE SRN FCST AREA IN THE GLOBAL GEM. WHILE THE DETAILS OF SHORTWAVE TRACK...RESULTING PCPN AREA AND THE ALL IMPORTANT TEMP PROFILE HAVE YET TO BE AGREED UPON...WHAT IS A LITTLE MORE CERTAIN IS THAT THIS WAVE MAY BE A RATHER IMPRESSIVE PCPN PRODUCER DESPITE THE FLATTER FLOW REGIME. STRONG WAA IS NOTED BY ALL GUIDANCE WITH 850MB WINDS AROUND 50KT. THE FRONTOGENESIS SIGNAL IS ALSO QUITE STRONG. PROXIMITY OF STEEP MIDLEVEL LAPSE RATES NEAR THE SRN EDGE OF THE PCPN AREA SUGGESTS THERE WILL PROBABLY BE SOME CONVECTION AS IS OFTEN SEEN WITH WAVES RUNNING ALONG THE BAROCLINIC ZONE AT THIS TIME OF YEAR. IT WILL BE A SYSTEM TO WATCH. IN THE WAKE OF THE SAT SYSTEM...DRY WEATHER SHOULD FOLLOW FOR SUN UNDER WEAK SFC HIGH PRES RIDGE...THOUGH IF THE SLOWER GLOBAL GEM AND ECMWF ARE RIGHT...SOME PCPN COULD LINGER THRU AT LEAST PART OF SUN. ATTENTION THEN TURNS TO THE SW FOR MON/TUE AS TROF AMPLIFIES INTO THE WRN CONUS. AMPLIFYING TROF MAY SEND SEVERAL SHORTWAVES INTO THE GREAT LAKES NEXT WEEK WITH THE FIRST PERHAPS AS SOON AS MON. AS WOULD BE EXPECTED WITH A DEEPENING WRN TROF...MODELS ARE AND WILL CONTINUE TO HAVE TROUBLE WITH TIMING AND PLACEMENT OF SHORTWAVES EJECTING NE...SO THERE IS LITTLE CONFIDENCE RIGHT NOW IN THE PCPN FCST MON/TUE. WITH GULF OPENING UP AHEAD OF THE LARGE SCALE WRN TROF...ANY SHORTWAVES AFFECTING THE AREA COULD BE MDT/HVY PCPN PRODUCERS NEXT WEEK...AND PCPN COULD BE SNOW FOR PORTIONS OF UPPER MI. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 135 PM EDT TUE APR 2 2013 AN UPPER LEVEL TROUGH WILL PASS THROUGH THE EASTERN PORTION OF THE UPPER PENINSULA LATE THIS EVENING INTO THE OVERNIGHT HOURS...HOWEVER THIS SHOULD DO NOTHING MORE THAN BRING INCREASED CLOUD COVER FOR MAINLY THE CMX AND SAW TAF SITES. CEILINGS AND VISIBILITIES ARE EXPECTED TO REMAIN VFR THROUGH THE TAF PERIOD. HIGH PRESSURE BUILDING INTO THE WEST WILL ALLOW THE WINDS TO DECREASE AND BECOME VARIABLE OVERNIGHT AT THE IWD TAF SITE...BEFORE SHIFTING TO THE SOUTH BY LATE WEDNESDAY MORNING AS THE HIGH SHIFTS TO THE EAST OF THE AREA. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 520 AM EDT TUE APR 2 2013 WHERE THE PRES GRADIENT WILL BE SHARPER CLOSER TO DEPARTING LO PRES IN SE CANADA...EXPECT NNW WINDS UP TO 30 KTS THRU TONIGHT OVER THE E ALONG WITH FREEZING SPRAY. LIGHTER WINDS UP TO 20 KTS WILL PREVAIL OVER THE W WHERE THE GRADIENT WILL BE WEAKER. AFTER A BRIEF PERIOD OF LIGHT WINDS FOR A PORTION OF WED AS HIGH PRES QUICKLY PASSES...S TO SW WINDS WILL QUICKLY RAMP UP TO 20-30KT WED AFTN/EVENING AHEAD OF LOW PRES TRACKING E INTO NRN ONTARIO. ALTHOUGH LOW-LEVEL TEMP PROFILE IS STABLE...HEALTHLY PRES FALLS PASSING ACROSS NRN ONTARIO SUGGEST THERE WILL BE SOME POTENTIAL FOR A SHORT PERIOD OF GALES WED NIGHT. WINDS SHIFT WNW FOR THU. WHILE WINDS WILL DIMINISH TO 15-25KT OVER THE W...20-30KT WINDS WILL CONTINUE OVER THE E. WINDS WILL THEN DIMINISH TO LIGHT (UNDER 15KT) FRI HAS HIGH PRES RIDGE ARRIVES. WINDS SHOULD REMAIN UNDER 20KT SAT...BUT WITH UNCERTAINTY IN THE STRENGTH/TRACK OF NEXT LOW PRES TRACKING E INTO THE GREAT LAKES... WINDS COULD END UP STRONGER THAN CURRENTLY FCST. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...ROLFSON AVIATION...KEC MARINE...KC/ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
731 AM EDT TUE APR 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 520 AM EDT TUE APR 2 2013 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF OVER THE E HALF OF NAMERICA DOWNSTREAM OF RDG OVER WRN CANADA. CWA REMAINS DOMINATED BY COLD CYC NW FLOW IN THE WAKE OF SLOWLY DEPARTING CLOSED LO OVER WRN QUEBEC. ALTHOUGH H85 TEMPS RANGING FM -14C OVER THE W TO -16C OVER THE E AND INVRN BASE NEAR H8 ARE SUFFICIENTLY COLD/HI FOR LES EVEN IN THE ABSENCE OF ANY DYNAMIC FORCING...UPSTREAM 00Z INL/YPL RAOBS ARE SO DRY...WITH THE H925 DEWPT DEPRESSION 15C AT INL IN INVERTED V T/TD PROFILE...THAT THERE ONLY A FEW WEAK CLD BANDS OVER THE W HALF OF LK SUP STREAMING INTO THE WRN ZNS. WITH A LONGER FETCH OVER THE E HALF AND A WEAK SFC TROF PASSING THRU THIS AREA...MORE CLDS/SOME LES BANDS ARE EVIDENT STREAMING INTO THE CWA E OF MQT. BUT DRYNESS OF AIRMASS IS EVIDENT IN LO REFLECTIVITIES. LOOKING FARTHER UPSTREAM...THERE IS A FAIRLY VIGOROUS SHRTWV NEAR LK WINNIPEG DIGGING SEWD. BUT SINCE THE 00Z THE PAS MANITOBA RAOB IS ALSO QUITE DRY WITH INVERTED V T/TD PROFILE IN THE LLVLS...THERE ARE ONLY SOME PATCHY MID/HI CLDS IN THE PVA ASSOCIATED WITH THIS FEATURE. ANOTHER SHRTWV OVER HUDSON BAY IS DIVING SWD. EARLY THIS MRNG/TODAY...WITH NOCTURNAL COOLING EARLY THIS MRNG AND SOME ENHANCED LLVL CNVGC ALONG WEAK SFC TROF...EXPECT SCT-NMRS -SHSN TO IMPACT THE ERN ZNS THRU THIS MRNG. OVER THE W...THERE SHOULD BE LTL IF ANY LES OR EVEN LK CLDS THRU 09Z GIVEN THE UPSTREAM DRYNESS...BUT MODELS SHOW AREA OF DPVA/H85-5 QVECTOR CNVGC ASSOCIATED WITH SHRTWV DIGGING THRU MN IMPACTING THE FAR W BY 12Z. SUSPECT MORE CLDS/A FEW -SHSN MIGHT DVLP IN PRESENCE OF NOCTURNAL COOLING...BUT LLVL DRYNESS WL LIMIT COVERAGE/INTENSITY OF ANY SHSN THAT MIGHT POP UP. IF THERE IS ANY SHSN...THESE SHOULD DIMINISH ONCE THE FORCING PASSES TO THE S BY 15Z AND DAYTIME HEATING BEGINS TO DISRUPT THE LES PROCESS. LATE IN THE DAY...NEXT SHRTWV OVER HUDSON BAY IS PROGGED TO DIG INTO THE UPR LKS WITH ACCOMPANYING DPVA AND H85-5 QVECTOR CNVGC IMPACTING THE CWA. ALTHOUGH DAYTIME HEATING MIGHT ALSO DISRUPT THE LES OVER THE E HALF IN THE AFTN...THE ARRIVAL OF THIS FORCING MIGHT CAUSE AN UPTICK OF SHSN AGAIN TOWARD 00Z ESPECIALLY OVER THE E HALF CLOSER TO DEEPER MSTR/COLDER AIR. AS FOR TEMPS...PREFER TO TEND TOWARD THE HIER END OF GUIDANCE WITH A GOOD DEAL OF SUNSHINE...AT LEAST OVER THE W AND SCENTRAL. TNGT...SHRTWV DROPPING S INTO THE UPR LKS AND ACCOMPANYING DYNAMIC FORCING IS PROGGED TO CROSS THE ERN COUNTIES. WITH LOWER H85 TEMPS ARND -17C CLOSER TO THE CYC SIDE OF THE TRACK OF THIS DISTURBANCE AS WELL AS DEEPER MSTR/SOMEWHAT HIER INVRN SHOWN THERE ON FCST SDNGS... OPTED TO RAISE POPS INTO THE LIKELY RANGE NEAR LK SUP E OF MQT AS THESE EVENTS OCCUR DURING THE MORE FAVORABLE NOCTURNAL COOLING. EXPECT MUCH LESS IF ANY ACTIVITY OVER THE W ON THE ACYC SIDE OF THE SHRTWV PASSAGE AND WHERE FCST SNDGS SHOW MUCH DRIER AIR AND HIER H85 TEMPS/LOWER INVNR BASE. EXPECT THE LOWEST MIN TEMPS TOWARD THE LOWER END OF GUIDANCE OVER THE INTERIOR W UNDER THE DRIER AIR AND WHERE WINDS WL BE LIGHTER. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 520 AM EDT TUE APR 2 2013 LOOKS LIKE A PATTERN CHANGE IS IN THE OFFING OVER THE NEXT FEW WEEKS THAT WILL TRANSITION THE PERSISTENT BELOW NORMAL TEMP REGIME TOWARD AN ABOVE NORMAL ONE. THE AO AND NAO WHICH HAVE BEEN IN A PREVAILING NEGATIVE PHASE SINCE EARLY/MID FEB ARE BOTH FORECAST TO TREND TO THE POSITIVE PHASE...WITH THE AO BECOMING STRONGLY POSITIVE. THIS SUPPORTS A TREND TOWARD ABOVE NORMAL TEMPS HEADING INTO MID/LATE APRIL...BUT THIS DOESN`T PRECLUDE THE POTENTIAL FOR MORE WINTRY PCPN EVENTS BEFORE THE WARMER PATTERN SETS IN. THE PATTERN ALSO APPEARS TO BE SHIFTING TOWARD AN ACTIVE ONE OVER THE NEXT 2 WEEKS. INTO THE UPCOMING WEEKEND...FLOW WILL TREND PROGRESSIVE AND FLATTER WITH A COUPLE OF SHORTWAVES TO AFFECT THE UPPER LAKES...THE FIRST WED NIGHT/THU AND A SECOND MORE IMPORTANT WAVE SAT. EARLY NEXT WEEK...AN AMPLIFIED TROF WILL BE DEVELOPING OVER THE WRN CONUS...SIGNALING THE POTENTIAL FOR MORE SIGNIFICANT PCPN EVENTS NEXT WEEK FROM THE CNTRL/SRN PLAINS TO THE GREAT LAKES AS THE GULF OPENS UP. THIS COULD MEAN ONE OR MORE UNWELCOMED RAIN EVENTS ON A MELTING SNOWPACK WHICH IS STILL DEEP IN THE LAKE EFFECT AREAS OR MORE SNOW COULD STILL BE ADDED. IN RECENT DAYS...MEDIUM RANGE GUIDANCE HAS TONED DOWN THE WARMING NEXT WEEK...SO MORE SNOW IS STILL A REAL POSSIBILITY. BEGINNING WED...SFC HIGH PRES WILL QUICKLY SHIFT ACROSS THE WRN GREAT LAKES AHEAD OF THE FIRST SHORTWAVE THAT WILL BE TRACKING ACROSS SASKATCHEWAN/MANITOBA. IF ANY LIGHT LES IS LINGERING OVER THE ERN FCST AREA TO START THE DAY...IT WILL END QUICKLY IN THE MORNING. AFTER A PERIOD OF SUNSHINE...HIGH CLOUDS WILL BE ON THE INCREASE. SUNSHINE WILL SUPPORT A STRONG DIURNAL TEMP SPREAD. AFTER MORNING LOWS IN THE SINGLE DIGITS OVER THE INTERIOR W...TEMPS SHOULD REBOUND INTO THE UPPER 30S/LWR 40S. SHORTWAVE WILL MOVE ACROSS NRN ONTARIO WED NIGHT/THU MORNING. WITH STRONG DEEP LAYER FORCING/IMPRESSIVE 500MB HEIGHT FALLS (AROUND 200M/12HR) PASSING WELL TO THE N OF HERE...MAIN PCPN AREA WILL PASS TO THE N OF UPPER MI. NONETHELESS...50-80M HEIGHT FALLS AT 500MB... RIBBON OF MODEST DEEP LAYER FORCING PER QVECTORS AND ISENTROPIC ASCENT SUGGEST SOME PCPN POTENTIAL ACROSS THE FCST AREA. WITH ISENTROPIC ASCENT WEAKENING AS IT SHIFTS ACROSS THE UPPER LAKES... AND LOW-LEVEL DRY AIR TO OVERCOME INITIALLY...NOTHING MORE THAN LOW CHC POPS APPEAR WARRANTED ATTM. ALTHOUGH LOW-LEVEL TEMPS ARE JUST ABOVE 0C PRIOR TO POTENTIAL PCPN ARRIVING...EVAPORATIVE COOLING SHOULD BE SUFFICIENT SO THAT SNOW BECOMES THE MAIN PTYPE IN MOST AREAS. PCPN CHC WILL END W TO E THU MORNING WITH DRY WEATHER FOLLOWING THRU THU NIGHT/FRI AS SFC HIGH PRES RIDGE BUILDS SE INTO THE UPPER LAKES. 850MB TEMPS FALLING TO AROUND -12C THU NIGHT/FRI MORNING WILL BE AT THE THRESHOLD FOR LES. HOWEVER...SINCE LOW-LEVEL FLOW BECOMES MORE ANTICYCLONIC DURING THE NIGHT AND AIR MASS IS FAIRLY DRY IN THE LOW-LEVELS...WILL NOT INCLUDE ANY MENTION OF -SHSN. OVER THE W...FLOW IS MORE DIVERGENT...SO THERE MAY NOT EVEN BE MUCH IN THE WAY OF CLOUDS. OPTED TO GO BLO GUIDANCE THERE THU NIGHT AS WINDS WILL PROBABLY FALL OFF TO CALM AS HIGH PRES RIDGE NEARS. ALTHOUGH LOWERED MINS TO THE LOW/MID TEENS...TEMPS COULD EASILY FALL INTO THE SINGLE DIGITS. FRI NIGHT/SAT...ATTENTION TURNS TO THE SECOND MORE IMPORTANT SHORTWAVE TRACKING ACROSS THE NRN CONUS IN FLATTER FLOW REGIME. MEDIUM RANGE GUIDANCE IS MOVING TOWARD SLIGHTLY BETTER AGREEMENT WITH SYSTEM...BUT IMPORTANT DETAILS HAVE YET TO BE NARROWED DOWN. THE GFS WHICH HAS BEEN CONSISTENTLY FARTHER S HAS TRENDED A LITTLE FARTHER N WITH WAVE AND IS IN DECENT AGREEMENT WITH THE GLOBAL GEM. THE ECMWF HAS BEEN CONSISTENTLY FARTHER N. THE GFS TRACK LOOKS TO SUPPORT ALL SNOW FOR THE FCST AREA AS THE 850MB LOW TRACKS ALONG WI/UPPER MI BORDER AND 850MB TEMPS REMAIN BLO 0C AND 1000-850MB THICKNESS IS NO HIGHER THAN 1295M. THE GLOBAL GEM MOSTLY SUPPORTS ALL SNOW WITH A POSSIBLE CHANGEOVER TO RAIN S AND SE...BUT ITS SLOWER/MORE WRAPPED UP SYSTEM DOES NOT APPEAR TO FIT THE DEVELOPING FLATTER FLOW REGIME. HOWEVER...THE 00Z ECMWF ALSO TRENDED MUCH SLOWER AND SHARPER WITH SHORTWAVE...SO THIS MAY BE AN IMPORTANT TREND TO MONITOR IN FUTURE MODEL RUNS. THE FARTHER N ECMWF SUGGESTS MORE OF A MIXED PCPN EVENT WITH MORE SNOW THAN RAIN N AND MORE RAIN THAN SNOW S. THE HEAVIEST SWATH OF PCPN PASSES ACROSS NRN UPPER MI IN THE ECMWF...JUST S IN THE GFS AND CLIPS THE SRN FCST AREA IN THE GLOBAL GEM. WHILE THE DETAILS OF SHORTWAVE TRACK...RESULTING PCPN AREA AND THE ALL IMPORTANT TEMP PROFILE HAVE YET TO BE AGREED UPON...WHAT IS A LITTLE MORE CERTAIN IS THAT THIS WAVE MAY BE A RATHER IMPRESSIVE PCPN PRODUCER DESPITE THE FLATTER FLOW REGIME. STRONG WAA IS NOTED BY ALL GUIDANCE WITH 850MB WINDS AROUND 50KT. THE FRONTOGENESIS SIGNAL IS ALSO QUITE STRONG. PROXIMITY OF STEEP MIDLEVEL LAPSE RATES NEAR THE SRN EDGE OF THE PCPN AREA SUGGESTS THERE WILL PROBABLY BE SOME CONVECTION AS IS OFTEN SEEN WITH WAVES RUNNING ALONG THE BAROCLINIC ZONE AT THIS TIME OF YEAR. IT WILL BE A SYSTEM TO WATCH. IN THE WAKE OF THE SAT SYSTEM...DRY WEATHER SHOULD FOLLOW FOR SUN UNDER WEAK SFC HIGH PRES RIDGE...THOUGH IF THE SLOWER GLOBAL GEM AND ECMWF ARE RIGHT...SOME PCPN COULD LINGER THRU AT LEAST PART OF SUN. ATTENTION THEN TURNS TO THE SW FOR MON/TUE AS TROF AMPLIFIES INTO THE WRN CONUS. AMPLIFYING TROF MAY SEND SEVERAL SHORTWAVES INTO THE GREAT LAKES NEXT WEEK WITH THE FIRST PERHAPS AS SOON AS MON. AS WOULD BE EXPECTED WITH A DEEPENING WRN TROF...MODELS ARE AND WILL CONTINUE TO HAVE TROUBLE WITH TIMING AND PLACEMENT OF SHORTWAVES EJECTING NE...SO THERE IS LITTLE CONFIDENCE RIGHT NOW IN THE PCPN FCST MON/TUE. WITH GULF OPENING UP AHEAD OF THE LARGE SCALE WRN TROF...ANY SHORTWAVES AFFECTING THE AREA COULD BE MDT/HVY PCPN PRODUCERS NEXT WEEK...AND PCPN COULD BE SNOW FOR PORTIONS OF UPPER MI. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 730 AM EDT TUE APR 2 2013 ALTHOUGH A LO PRES TROF WILL PASS THIS EVNG...EXPECT VFR CONDITIONS AT THE TAF SITES THIS PERIOD WITH DRY LLVL AIR. WITH DAYTIME HEATING...THERE WL BE A GUSTY NW WIND MUCH OF TODAY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 520 AM EDT TUE APR 2 2013 WHERE THE PRES GRADIENT WILL BE SHARPER CLOSER TO DEPARTING LO PRES IN SE CANADA...EXPECT NNW WINDS UP TO 30 KTS THRU TONIGHT OVER THE E ALONG WITH FREEZING SPRAY. LIGHTER WINDS UP TO 20 KTS WILL PREVAIL OVER THE W WHERE THE GRADIENT WILL BE WEAKER. AFTER A BRIEF PERIOD OF LIGHT WINDS FOR A PORTION OF WED AS HIGH PRES QUICKLY PASSES...S TO SW WINDS WILL QUICKLY RAMP UP TO 20-30KT WED AFTN/EVENING AHEAD OF LOW PRES TRACKING E INTO NRN ONTARIO. ALTHOUGH LOW-LEVEL TEMP PROFILE IS STABLE...HEALTHLY PRES FALLS PASSING ACROSS NRN ONTARIO SUGGEST THERE WILL BE SOME POTENTIAL FOR A SHORT PERIOD OF GALES WED NIGHT. WINDS SHIFT WNW FOR THU. WHILE WINDS WILL DIMINISH TO 15-25KT OVER THE W...20-30KT WINDS WILL CONTINUE OVER THE E. WINDS WILL THEN DIMINISH TO LIGHT (UNDER 15KT) FRI HAS HIGH PRES RIDGE ARRIVES. WINDS SHOULD REMAIN UNDER 20KT SAT...BUT WITH UNCERTAINTY IN THE STRENGTH/TRACK OF NEXT LOW PRES TRACKING E INTO THE GREAT LAKES... WINDS COULD END UP STRONGER THAN CURRENTLY FCST. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...ROLFSON AVIATION...KC MARINE...KC/ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
524 AM EDT TUE APR 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 520 AM EDT TUE APR 2 2013 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF OVER THE E HALF OF NAMERICA DOWNSTREAM OF RDG OVER WRN CANADA. CWA REMAINS DOMINATED BY COLD CYC NW FLOW IN THE WAKE OF SLOWLY DEPARTING CLOSED LO OVER WRN QUEBEC. ALTHOUGH H85 TEMPS RANGING FM -14C OVER THE W TO -16C OVER THE E AND INVRN BASE NEAR H8 ARE SUFFICIENTLY COLD/HI FOR LES EVEN IN THE ABSENCE OF ANY DYNAMIC FORCING...UPSTREAM 00Z INL/YPL RAOBS ARE SO DRY...WITH THE H925 DEWPT DEPRESSION 15C AT INL IN INVERTED V T/TD PROFILE...THAT THERE ONLY A FEW WEAK CLD BANDS OVER THE W HALF OF LK SUP STREAMING INTO THE WRN ZNS. WITH A LONGER FETCH OVER THE E HALF AND A WEAK SFC TROF PASSING THRU THIS AREA...MORE CLDS/SOME LES BANDS ARE EVIDENT STREAMING INTO THE CWA E OF MQT. BUT DRYNESS OF AIRMASS IS EVIDENT IN LO REFLECTIVITIES. LOOKING FARTHER UPSTREAM...THERE IS A FAIRLY VIGOROUS SHRTWV NEAR LK WINNIPEG DIGGING SEWD. BUT SINCE THE 00Z THE PAS MANITOBA RAOB IS ALSO QUITE DRY WITH INVERTED V T/TD PROFILE IN THE LLVLS...THERE ARE ONLY SOME PATCHY MID/HI CLDS IN THE PVA ASSOCIATED WITH THIS FEATURE. ANOTHER SHRTWV OVER HUDSON BAY IS DIVING SWD. EARLY THIS MRNG/TODAY...WITH NOCTURNAL COOLING EARLY THIS MRNG AND SOME ENHANCED LLVL CNVGC ALONG WEAK SFC TROF...EXPECT SCT-NMRS -SHSN TO IMPACT THE ERN ZNS THRU THIS MRNG. OVER THE W...THERE SHOULD BE LTL IF ANY LES OR EVEN LK CLDS THRU 09Z GIVEN THE UPSTREAM DRYNESS...BUT MODELS SHOW AREA OF DPVA/H85-5 QVECTOR CNVGC ASSOCIATED WITH SHRTWV DIGGING THRU MN IMPACTING THE FAR W BY 12Z. SUSPECT MORE CLDS/A FEW -SHSN MIGHT DVLP IN PRESENCE OF NOCTURNAL COOLING...BUT LLVL DRYNESS WL LIMIT COVERAGE/INTENSITY OF ANY SHSN THAT MIGHT POP UP. IF THERE IS ANY SHSN...THESE SHOULD DIMINISH ONCE THE FORCING PASSES TO THE S BY 15Z AND DAYTIME HEATING BEGINS TO DISRUPT THE LES PROCESS. LATE IN THE DAY...NEXT SHRTWV OVER HUDSON BAY IS PROGGED TO DIG INTO THE UPR LKS WITH ACCOMPANYING DPVA AND H85-5 QVECTOR CNVGC IMPACTING THE CWA. ALTHOUGH DAYTIME HEATING MIGHT ALSO DISRUPT THE LES OVER THE E HALF IN THE AFTN...THE ARRIVAL OF THIS FORCING MIGHT CAUSE AN UPTICK OF SHSN AGAIN TOWARD 00Z ESPECIALLY OVER THE E HALF CLOSER TO DEEPER MSTR/COLDER AIR. AS FOR TEMPS...PREFER TO TEND TOWARD THE HIER END OF GUIDANCE WITH A GOOD DEAL OF SUNSHINE...AT LEAST OVER THE W AND SCENTRAL. TNGT...SHRTWV DROPPING S INTO THE UPR LKS AND ACCOMPANYING DYNAMIC FORCING IS PROGGED TO CROSS THE ERN COUNTIES. WITH LOWER H85 TEMPS ARND -17C CLOSER TO THE CYC SIDE OF THE TRACK OF THIS DISTURBANCE AS WELL AS DEEPER MSTR/SOMEWHAT HIER INVRN SHOWN THERE ON FCST SDNGS... OPTED TO RAISE POPS INTO THE LIKELY RANGE NEAR LK SUP E OF MQT AS THESE EVENTS OCCUR DURING THE MORE FAVORABLE NOCTURNAL COOLING. EXPECT MUCH LESS IF ANY ACTIVITY OVER THE W ON THE ACYC SIDE OF THE SHRTWV PASSAGE AND WHERE FCST SNDGS SHOW MUCH DRIER AIR AND HIER H85 TEMPS/LOWER INVNR BASE. EXPECT THE LOWEST MIN TEMPS TOWARD THE LOWER END OF GUIDANCE OVER THE INTERIOR W UNDER THE DRIER AIR AND WHERE WINDS WL BE LIGHTER. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 520 AM EDT TUE APR 2 2013 LOOKS LIKE A PATTERN CHANGE IS IN THE OFFING OVER THE NEXT FEW WEEKS THAT WILL TRANSITION THE PERSISTENT BELOW NORMAL TEMP REGIME TOWARD AN ABOVE NORMAL ONE. THE AO AND NAO WHICH HAVE BEEN IN A PREVAILING NEGATIVE PHASE SINCE EARLY/MID FEB ARE BOTH FORECAST TO TREND TO THE POSITIVE PHASE...WITH THE AO BECOMING STRONGLY POSITIVE. THIS SUPPORTS A TREND TOWARD ABOVE NORMAL TEMPS HEADING INTO MID/LATE APRIL...BUT THIS DOESN`T PRECLUDE THE POTENTIAL FOR MORE WINTRY PCPN EVENTS BEFORE THE WARMER PATTERN SETS IN. THE PATTERN ALSO APPEARS TO BE SHIFTING TOWARD AN ACTIVE ONE OVER THE NEXT 2 WEEKS. INTO THE UPCOMING WEEKEND...FLOW WILL TREND PROGRESSIVE AND FLATTER WITH A COUPLE OF SHORTWAVES TO AFFECT THE UPPER LAKES...THE FIRST WED NIGHT/THU AND A SECOND MORE IMPORTANT WAVE SAT. EARLY NEXT WEEK...AN AMPLIFIED TROF WILL BE DEVELOPING OVER THE WRN CONUS...SIGNALING THE POTENTIAL FOR MORE SIGNIFICANT PCPN EVENTS NEXT WEEK FROM THE CNTRL/SRN PLAINS TO THE GREAT LAKES AS THE GULF OPENS UP. THIS COULD MEAN ONE OR MORE UNWELCOMED RAIN EVENTS ON A MELTING SNOWPACK WHICH IS STILL DEEP IN THE LAKE EFFECT AREAS OR MORE SNOW COULD STILL BE ADDED. IN RECENT DAYS...MEDIUM RANGE GUIDANCE HAS TONED DOWN THE WARMING NEXT WEEK...SO MORE SNOW IS STILL A REAL POSSIBILITY. BEGINNING WED...SFC HIGH PRES WILL QUICKLY SHIFT ACROSS THE WRN GREAT LAKES AHEAD OF THE FIRST SHORTWAVE THAT WILL BE TRACKING ACROSS SASKATCHEWAN/MANITOBA. IF ANY LIGHT LES IS LINGERING OVER THE ERN FCST AREA TO START THE DAY...IT WILL END QUICKLY IN THE MORNING. AFTER A PERIOD OF SUNSHINE...HIGH CLOUDS WILL BE ON THE INCREASE. SUNSHINE WILL SUPPORT A STRONG DIURNAL TEMP SPREAD. AFTER MORNING LOWS IN THE SINGLE DIGITS OVER THE INTERIOR W...TEMPS SHOULD REBOUND INTO THE UPPER 30S/LWR 40S. SHORTWAVE WILL MOVE ACROSS NRN ONTARIO WED NIGHT/THU MORNING. WITH STRONG DEEP LAYER FORCING/IMPRESSIVE 500MB HEIGHT FALLS (AROUND 200M/12HR) PASSING WELL TO THE N OF HERE...MAIN PCPN AREA WILL PASS TO THE N OF UPPER MI. NONETHELESS...50-80M HEIGHT FALLS AT 500MB... RIBBON OF MODEST DEEP LAYER FORCING PER QVECTORS AND ISENTROPIC ASCENT SUGGEST SOME PCPN POTENTIAL ACROSS THE FCST AREA. WITH ISENTROPIC ASCENT WEAKENING AS IT SHIFTS ACROSS THE UPPER LAKES... AND LOW-LEVEL DRY AIR TO OVERCOME INITIALLY...NOTHING MORE THAN LOW CHC POPS APPEAR WARRANTED ATTM. ALTHOUGH LOW-LEVEL TEMPS ARE JUST ABOVE 0C PRIOR TO POTENTIAL PCPN ARRIVING...EVAPORATIVE COOLING SHOULD BE SUFFICIENT SO THAT SNOW BECOMES THE MAIN PTYPE IN MOST AREAS. PCPN CHC WILL END W TO E THU MORNING WITH DRY WEATHER FOLLOWING THRU THU NIGHT/FRI AS SFC HIGH PRES RIDGE BUILDS SE INTO THE UPPER LAKES. 850MB TEMPS FALLING TO AROUND -12C THU NIGHT/FRI MORNING WILL BE AT THE THRESHOLD FOR LES. HOWEVER...SINCE LOW-LEVEL FLOW BECOMES MORE ANTICYCLONIC DURING THE NIGHT AND AIR MASS IS FAIRLY DRY IN THE LOW-LEVELS...WILL NOT INCLUDE ANY MENTION OF -SHSN. OVER THE W...FLOW IS MORE DIVERGENT...SO THERE MAY NOT EVEN BE MUCH IN THE WAY OF CLOUDS. OPTED TO GO BLO GUIDANCE THERE THU NIGHT AS WINDS WILL PROBABLY FALL OFF TO CALM AS HIGH PRES RIDGE NEARS. ALTHOUGH LOWERED MINS TO THE LOW/MID TEENS...TEMPS COULD EASILY FALL INTO THE SINGLE DIGITS. FRI NIGHT/SAT...ATTENTION TURNS TO THE SECOND MORE IMPORTANT SHORTWAVE TRACKING ACROSS THE NRN CONUS IN FLATTER FLOW REGIME. MEDIUM RANGE GUIDANCE IS MOVING TOWARD SLIGHTLY BETTER AGREEMENT WITH SYSTEM...BUT IMPORTANT DETAILS HAVE YET TO BE NARROWED DOWN. THE GFS WHICH HAS BEEN CONSISTENTLY FARTHER S HAS TRENDED A LITTLE FARTHER N WITH WAVE AND IS IN DECENT AGREEMENT WITH THE GLOBAL GEM. THE ECMWF HAS BEEN CONSISTENTLY FARTHER N. THE GFS TRACK LOOKS TO SUPPORT ALL SNOW FOR THE FCST AREA AS THE 850MB LOW TRACKS ALONG WI/UPPER MI BORDER AND 850MB TEMPS REMAIN BLO 0C AND 1000-850MB THICKNESS IS NO HIGHER THAN 1295M. THE GLOBAL GEM MOSTLY SUPPORTS ALL SNOW WITH A POSSIBLE CHANGEOVER TO RAIN S AND SE...BUT ITS SLOWER/MORE WRAPPED UP SYSTEM DOES NOT APPEAR TO FIT THE DEVELOPING FLATTER FLOW REGIME. HOWEVER...THE 00Z ECMWF ALSO TRENDED MUCH SLOWER AND SHARPER WITH SHORTWAVE...SO THIS MAY BE AN IMPORTANT TREND TO MONITOR IN FUTURE MODEL RUNS. THE FARTHER N ECMWF SUGGESTS MORE OF A MIXED PCPN EVENT WITH MORE SNOW THAN RAIN N AND MORE RAIN THAN SNOW S. THE HEAVIEST SWATH OF PCPN PASSES ACROSS NRN UPPER MI IN THE ECMWF...JUST S IN THE GFS AND CLIPS THE SRN FCST AREA IN THE GLOBAL GEM. WHILE THE DETAILS OF SHORTWAVE TRACK...RESULTING PCPN AREA AND THE ALL IMPORTANT TEMP PROFILE HAVE YET TO BE AGREED UPON...WHAT IS A LITTLE MORE CERTAIN IS THAT THIS WAVE MAY BE A RATHER IMPRESSIVE PCPN PRODUCER DESPITE THE FLATTER FLOW REGIME. STRONG WAA IS NOTED BY ALL GUIDANCE WITH 850MB WINDS AROUND 50KT. THE FRONTOGENESIS SIGNAL IS ALSO QUITE STRONG. PROXIMITY OF STEEP MIDLEVEL LAPSE RATES NEAR THE SRN EDGE OF THE PCPN AREA SUGGESTS THERE WILL PROBABLY BE SOME CONVECTION AS IS OFTEN SEEN WITH WAVES RUNNING ALONG THE BAROCLINIC ZONE AT THIS TIME OF YEAR. IT WILL BE A SYSTEM TO WATCH. IN THE WAKE OF THE SAT SYSTEM...DRY WEATHER SHOULD FOLLOW FOR SUN UNDER WEAK SFC HIGH PRES RIDGE...THOUGH IF THE SLOWER GLOBAL GEM AND ECMWF ARE RIGHT...SOME PCPN COULD LINGER THRU AT LEAST PART OF SUN. ATTENTION THEN TURNS TO THE SW FOR MON/TUE AS TROF AMPLIFIES INTO THE WRN CONUS. AMPLIFYING TROF MAY SEND SEVERAL SHORTWAVES INTO THE GREAT LAKES NEXT WEEK WITH THE FIRST PERHAPS AS SOON AS MON. AS WOULD BE EXPECTED WITH A DEEPENING WRN TROF...MODELS ARE AND WILL CONTINUE TO HAVE TROUBLE WITH TIMING AND PLACEMENT OF SHORTWAVES EJECTING NE...SO THERE IS LITTLE CONFIDENCE RIGHT NOW IN THE PCPN FCST MON/TUE. WITH GULF OPENING UP AHEAD OF THE LARGE SCALE WRN TROF...ANY SHORTWAVES AFFECTING THE AREA COULD BE MDT/HVY PCPN PRODUCERS NEXT WEEK...AND PCPN COULD BE SNOW FOR PORTIONS OF UPPER MI. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 812 PM EDT MON APR 1 2013 DRY AIR MOVING ACROSS LAKE SUPERIOR SHOULD HELP KEEP TAF SITES MOSTLY CLEAR THROUGH THE EVENING HRS. A DISTURBANCE MOVING DOWN FM CANADA COULD HELP GENERATE SOME LAKE CLOUDS AND FLURRIES LATE TONIGHT INTO TUESDAY...ESPECIALLY AS WINDS OVER THE LAKE VEER NNW ALLOWING FOR INCREASED LOW-LVL CONVERGENCE. EXPECT CIGS TO LOWER TO MVFR AS ALL TAF SITES WITH SOME LIGHT -SHSN/FLURRIES. INCREASINGLY ANTICYCLONIC AND DIFLUENT LOW-LVL FLOW BY 18Z TUE SHOULD ALLOW FOR MVFR CLOUDS TO ERODE AND VFR CONDITIONS TO RETURN. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 520 AM EDT TUE APR 2 2013 WHERE THE PRES GRADIENT WILL BE SHARPER CLOSER TO DEPARTING LO PRES IN SE CANADA...EXPECT NNW WINDS UP TO 30 KTS THRU TONIGHT OVER THE E ALONG WITH FREEZING SPRAY. LIGHTER WINDS UP TO 20 KTS WILL PREVAIL OVER THE W WHERE THE GRADIENT WILL BE WEAKER. AFTER A BRIEF PERIOD OF LIGHT WINDS FOR A PORTION OF WED AS HIGH PRES QUICKLY PASSES...S TO SW WINDS WILL QUICKLY RAMP UP TO 20-30KT WED AFTN/EVENING AHEAD OF LOW PRES TRACKING E INTO NRN ONTARIO. ALTHOUGH LOW-LEVEL TEMP PROFILE IS STABLE...HEALTHLY PRES FALLS PASSING ACROSS NRN ONTARIO SUGGEST THERE WILL BE SOME POTENTIAL FOR A SHORT PERIOD OF GALES WED NIGHT. WINDS SHIFT WNW FOR THU. WHILE WINDS WILL DIMINISH TO 15-25KT OVER THE W...20-30KT WINDS WILL CONTINUE OVER THE E. WINDS WILL THEN DIMINISH TO LIGHT (UNDER 15KT) FRI HAS HIGH PRES RIDGE ARRIVES. WINDS SHOULD REMAIN UNDER 20KT SAT...BUT WITH UNCERTAINTY IN THE STRENGTH/TRACK OF NEXT LOW PRES TRACKING E INTO THE GREAT LAKES... WINDS COULD END UP STRONGER THAN CURRENTLY FCST. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...ROLFSON AVIATION...VOSS MARINE...KC/ROLFSON
AREA FORECAST DISCUSSION
NWS BILLINGS MT
923 PM MDT WED APR 3 2013 .SHORT TERM...VALID FOR THU AND FRI... WEAK UPSLOPE FLOW AND ISENTROPIC LIFT HAS SET UP OVER THE ENTIRE AREA THIS EVENING BEHIND A COLD FRONT THAT HAS MOVED WEST OF LIVINGSTON. WEAK UPPER LEVEL SHORT WAVE CURRENTLY MOVING ACROSS THE WEST ALONG WITH THE LEFT EXIT REGION OF THE UPPER LEVEL JET. RADAR RETURNS DURING THE LAST HOUR HAVE INCREASED BUT SURFACE DEW POINT TEMPERATURES REMAIN LOW AND MUCH OF THIS PRECIP IS NOT HITTING THE GROUND. MODELS ARE OVERDONE WITH QPF VALUES TONIGHT BUT THE RAP MODELS SEEMS TO BE THE BETTER MODEL AND WILL KEEP ISOLATED POPS GOING FOR BILLINGS WEST FOR THE REMAINDER OF THE EVENING. WILL KEEP SCATTERED POPS AFTER 06Z EAST OF BILLINGS. MET GUIDANCE HAS COME IN WITH SLIGHTLY WARMER OVERNIGHT LOWS FOR BILLINGS AND LIVINGSTON TONIGHT AND HAVE RAISED POPS A FEW DEGREES FOR OVERNIGHT LOWS. ALSO MADE SOME WIND ADJUSTMENTS OVER SOUTHEAST MONTANA. RICHMOND .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... FAIRLY ACTIVE AND SPRING-LIKE WEATHER PATTERN SHAPING UP FOR THE EXTENDED PERIOD...THOUGH LATEST MODELS HAVE SHIFTED A BIT FOR THE MON/TUE TIME FRAME. SATURDAY STILL LOOKING FAIRLY QUIET WITH RIDGING BEHIND LATE FRIDAY WAVE. HAVE REDUCED POPS FOR ALL BUT OUR WEST...WHICH SHOULD BEGIN TO SEE INCREASED SHOWER ACTIVITY BY AFTERNOON...AND PER WESTERLY DOWNSLOPE WINDS HAVE ALSO RAISED TEMPS A FEW DEGREES. SHOULD SEE HIGHS INTO THE LOWER/MID 60S. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH TIMING A SHORTWAVE THROUGH THE REGION SATURDAY NIGHT. WITH INCREASING CONFIDENCE HAVE RAISED POPS A BIT MORE...TO LIKELY IN CENTRAL AND EAST PARTS AWAY FROM THE DOWNSLOPING WESTERN FOOTHILLS. AIRMASS LOOKS TO BE TOO WARM FOR ANYTHING BUT RAIN SHOWERS AT OUR LOWER ELEVATIONS...WITH A POSSIBLE EXCEPTION IN OUR FAR NE WHERE LOW LEVEL EAST WINDS MAY KEEP 850MB TEMPS NEAR ZERO. SO WILL KEEP A RAIN/SNOW MIX WITH JUST A LITTLE ACCUMULATION FROM MILES CITY TO BAKER...BUT THE BETTER SNOW POTENTIAL REALLY SHOULD BE NORTH AND NORTHEAST OF OUR CWA. SYSTEM WILL EXIT QUICKLY INTO THE DAKOTAS AROUND 12Z SUNDAY. NEXT PACIFIC ENERGY WILL BEGIN TO INFLUENCE OUR WEST BY SUNDAY AFTERNOON OR NIGHT...SOME TIMING ISSUES EXIST HERE. THEN...AS PREVIOUSLY MENTIONED...MODELS ARE BEGINNING TO PAINT A DIFFERENT PICTURE WITH EVOLUTION OF THIS SYSTEM INTO MON/TUE. FLOW IN THE EASTERN PACIFIC NOW EXPECTED TO BE A BIT FLATTER...WITH AMPLIFICATION OVER THE WESTERN CONUS SHIFTED A BIT EAST. THUS... PER LATEST TRENDS...A LARGE CLOSED LOW OVER THE GREAT BASIN TO 4-CORNERS REGION NOW LOOKS LESS LIKELY...WHICH LEAVES A WNW FLOW WITH LOWER HEIGHTS OVER OUR REGION AS ENERGY DRIVES TO THE CENTRAL ROCKIES AND MIDDLE PLAINS. COULD STILL SEE SOME WET SNOW IMPACTS IN OUR AREA SOMETIME IN THE SUNDAY NIGHT INTO TUESDAY TIME FRAME...AND BOTH THE GFS AND EC SHOW 850MB TEMPS NEAR OR SLIGHTLY BELOW ZERO...BUT OVERALL POTENTIAL APPEARS LOWER NOW. PROGRESSIVE SHORTWAVE ENERGY IN LOW HEIGHT REGIME AND LOW LEVEL UPSLOPE FLOW ALL COMBINE TO WARRANT ABOVE CLIMO POPS FOR US NONETHELESS. WILL TAPER POPS TO BELOW CLIMO...SLIGHT CHANCE...BY WEDNESDAY AS MODEL CONSENSUS IS FOR RISING HEIGHTS WITH RIDGE BEGINNING TO BUILD OVER THE PAC NW BY THEN. AS FOR TEMPERATURES...ABOVE NORMAL SATURDAY SHOULD COOL TO NEAR NORMAL SUNDAY AND BELOW NORMAL MONDAY AND TUESDAY. COULD SEE A RETURN TO NEAR OR ABOVE NORMAL TEMPS BY THE MIDDLE OF NEXT WEEK... AND HAVE ADJUSTED GRIDS ACCORDINGLY. JKL && .AVIATION... EXPECT ISOLATED TO SCATTERED SHOWERS TO LINGER ALONG A FRONTAL BOUNDARY NEAR KLVM AND THE NEARBY FOOTHILLS THROUGH MIDNIGHT...WITH DRYING ANTICIPATED AFTER MIDNIGHT. LOCALIZED MVFR IS POSSIBLE WITH THE SHOWER ACTIVITY. VFR CONDITIONS WILL PREVAIL ACROSS THE AREA LATE TONIGHT AND THURSDAY. CHURCH && .PRELIMINARY POINT TEMP/POPS... THU FRI SAT SUN MON TUE WED ----------------------------------------------------------- BIL 035/064 043/064 038/063 038/057 032/046 029/048 030/056 20/B 37/T 32/W 52/W 35/W 42/W 22/W LVM 034/064 039/058 033/061 031/055 029/044 028/046 028/055 21/B 26/T 24/W 53/W 35/J 32/W 22/W HDN 033/065 041/068 038/065 036/059 031/047 029/049 028/054 20/B 37/T 32/W 62/W 35/W 42/W 22/W MLS 032/057 038/067 038/061 035/055 029/045 027/045 026/049 22/W 24/T 31/B 62/W 24/W 42/W 22/W 4BQ 032/064 040/066 038/062 036/056 032/046 028/044 024/046 21/B 14/T 41/B 63/W 24/W 43/W 22/W BHK 027/050 032/061 035/055 031/050 027/041 023/041 023/043 23/W 13/T 31/B 64/W 33/W 33/J 22/W SHR 033/064 039/066 035/061 033/056 030/045 027/045 027/051 20/B 14/T 31/B 32/W 35/W 43/W 22/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
628 PM MDT WED APR 3 2013 .SHORT TERM...VALID FOR THU AND FRI... QUICK UPDATE TO REMOVE LATE AFTERNOON WORDING FROM ZONES. RADAR SHOWING ISOLATED SHOWERS OVER OUR WESTERN ZONES BUT THEY HAVE BEEN DISSIPATING AS THEY PUSH EAST. WATER VAPOR SATELLITE INDICATING DRIER AIR MOVING IN BEHIND THE CURRENT UPPER LEVEL WAVE MOVING OVER OUR WESTERN ZONES. CURRENT FORECAST HAS THIS HANDLED WELL WITH PRECIP ENDING LATE THIS EVENING. WILL DO ANOTHER UPDATE AROUND 9 PM. RICHMOND PREVIOUS DISCUSSION... COLD FRONT HAD PUSHED THROUGH THE FRONT RANGE OF MONTANA BY EARLY AFTERNOON AND IS CHUGGING ALONG PRETTY GOOD. I LIKE THE RAP MODELS TIMING WHICH SWITCHES BILLINGS WINDS TO THE NORTHEAST LATE THIS AFTERNOON AND SHERIDANS BY 8 PM. THE RAP ALSO BRINGS EASTERLY WIND INTO LIVINGSTON AT THAT POINT...BUT WE ARE LESS CONFIDENT IN THIS OCCURRING...AND BELIEVE THE COOLER AIR MIGHT STAY JUST EAST OF LIVINGSTON DOORSTEP. AT ANY RATE MODELS ARE GENERATING DECENT FRONTOGENESIS OVER OUR WESTERN ZONES LATE TODAY AND THERE APPEARS TO BE SOME MODEST CONVECTION DEVELOPING JUST UPSTREAM OF THIS AREA. SOME WEAK ENERGY CONTINUES TO MOVE ACROSS EAST CENTRAL MONTANA OVERNIGHT...SO WILL CONTINUE TO INCLUDE SOME LOW POPS AFTER MIDNIGHT. THURSDAY OUR FORECAST AREA WILL GENERALLY BE BETWEEN SYSTEMS WITH LOW AMPLITUDE RIDGING AND SURFACE TROUGHING DEVELOPING BEFORE EVENING. THE MAIN WEATHER FEATURE THURSDAY WILL BE THE BACKING UPPER FLOW BRINGING A NICE FETCH OF PACIFIC MOISTURE INTO THE INNER ROCKIES. SO WE EXPECT INCREASING CLOUD COVER TO LIMIT TEMPERATURES AND MIXING SOMEWHAT. BY THURSDAY NIGHT...WEAK ENERGY INVOLVED WITH THAT MOISTURE FETCH MAY SPREAD SOME LIGHT SHOWERS ACROSS THE REGION. HOWEVER THE MAIN PLAYER CONTINUES TO BE A LOW AMPLITUDE SHORT WAVE PROGGED TO CROSS OUR FORECAST AREA FRIDAY. MODELS AGREE THAT Q VECTOR FORCING WILL BE RIGHT OVER OUR ZONES FRIDAY AFTERNOON WITH DECENT CAPE ON THE ORDER FROM 200-400 JL/KG. I CONTINUED TO NUDGE THE POPS UP FOR FRIDAY AFTERNOON IN MANY LOCATIONS AND WENT CATEGORICAL IN THE HIGH COUNTRY. THE GFS LINGERS QPF OVER OUR FORECAST AREA WELL INTO FRIDAY NIGHT...BUT THE OVERALL CONSENSUS OF MODELS GENERALLY EXIT THIS FORCING TO THE EAST IN THE EVENING. THIS SEEMS MORE LIKELY GIVEN THE GOOD CONVERGENT/DIVERGENT COUPLET...SO TRENDED OUR POPS LOWER OVERNIGHT. BT .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... FAIRLY ACTIVE AND SPRING-LIKE WEATHER PATTERN SHAPING UP FOR THE EXTENDED PERIOD...THOUGH LATEST MODELS HAVE SHIFTED A BIT FOR THE MON/TUE TIME FRAME. SATURDAY STILL LOOKING FAIRLY QUIET WITH RIDGING BEHIND LATE FRIDAY WAVE. HAVE REDUCED POPS FOR ALL BUT OUR WEST...WHICH SHOULD BEGIN TO SEE INCREASED SHOWER ACTIVITY BY AFTERNOON...AND PER WESTERLY DOWNSLOPE WINDS HAVE ALSO RAISED TEMPS A FEW DEGREES. SHOULD SEE HIGHS INTO THE LOWER/MID 60S. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH TIMING A SHORTWAVE THROUGH THE REGION SATURDAY NIGHT. WITH INCREASING CONFIDENCE HAVE RAISED POPS A BIT MORE...TO LIKELY IN CENTRAL AND EAST PARTS AWAY FROM THE DOWNSLOPING WESTERN FOOTHILLS. AIRMASS LOOKS TO BE TOO WARM FOR ANYTHING BUT RAIN SHOWERS AT OUR LOWER ELEVATIONS...WITH A POSSIBLE EXCEPTION IN OUR FAR NE WHERE LOW LEVEL EAST WINDS MAY KEEP 850MB TEMPS NEAR ZERO. SO WILL KEEP A RAIN/SNOW MIX WITH JUST A LITTLE ACCUMULATION FROM MILES CITY TO BAKER...BUT THE BETTER SNOW POTENTIAL REALLY SHOULD BE NORTH AND NORTHEAST OF OUR CWA. SYSTEM WILL EXIT QUICKLY INTO THE DAKOTAS AROUND 12Z SUNDAY. NEXT PACIFIC ENERGY WILL BEGIN TO INFLUENCE OUR WEST BY SUNDAY AFTERNOON OR NIGHT...SOME TIMING ISSUES EXIST HERE. THEN...AS PREVIOUSLY MENTIONED...MODELS ARE BEGINNING TO PAINT A DIFFERENT PICTURE WITH EVOLUTION OF THIS SYSTEM INTO MON/TUE. FLOW IN THE EASTERN PACIFIC NOW EXPECTED TO BE A BIT FLATTER...WITH AMPLIFICATION OVER THE WESTERN CONUS SHIFTED A BIT EAST. THUS... PER LATEST TRENDS...A LARGE CLOSED LOW OVER THE GREAT BASIN TO 4-CORNERS REGION NOW LOOKS LESS LIKELY...WHICH LEAVES A WNW FLOW WITH LOWER HEIGHTS OVER OUR REGION AS ENERGY DRIVES TO THE CENTRAL ROCKIES AND MIDDLE PLAINS. COULD STILL SEE SOME WET SNOW IMPACTS IN OUR AREA SOMETIME IN THE SUNDAY NIGHT INTO TUESDAY TIME FRAME...AND BOTH THE GFS AND EC SHOW 850MB TEMPS NEAR OR SLIGHTLY BELOW ZERO...BUT OVERALL POTENTIAL APPEARS LOWER NOW. PROGRESSIVE SHORTWAVE ENERGY IN LOW HEIGHT REGIME AND LOW LEVEL UPSLOPE FLOW ALL COMBINE TO WARRANT ABOVE CLIMO POPS FOR US NONETHELESS. WILL TAPER POPS TO BELOW CLIMO...SLIGHT CHANCE...BY WEDNESDAY AS MODEL CONSENSUS IS FOR RISING HEIGHTS WITH RIDGE BEGINNING TO BUILD OVER THE PAC NW BY THEN. AS FOR TEMPERATURES...ABOVE NORMAL SATURDAY SHOULD COOL TO NEAR NORMAL SUNDAY AND BELOW NORMAL MONDAY AND TUESDAY. COULD SEE A RETURN TO NEAR OR ABOVE NORMAL TEMPS BY THE MIDDLE OF NEXT WEEK... AND HAVE ADJUSTED GRIDS ACCORDINGLY. JKL && .AVIATION... A CANADIAN COLD FRONT IS PUSHING SOUTHWARD THROUGH THE AREA THIS AFTERNOON...CAUSING GUSTY NW-N-NE WINDS ACROSS THE LOWER ELEVATIONS...WITH GUSTS TO 25 KTS UNTIL SUNSET. EXPECT ISOLATED TO SCATTERED SHOWERS TO DEVELOP ALONG THIS FRONTAL BOUNDARY FROM KLVM TO KBIL AND KSHR THROUGH AROUND 04Z...WITH DRYING ANTICIPATED LATER TONIGHT. LOCALIZED MVFR IS POSSIBLE WITH THE SHOWER ACTIVITY. VFR CONDITIONS WILL PREVAIL ACROSS THE AREA LATE TONIGHT AND THURSDAY. JKL && .PRELIMINARY POINT TEMP/POPS... THU FRI SAT SUN MON TUE WED ----------------------------------------------------------- BIL 034/064 043/064 038/063 038/057 032/046 029/048 030/056 20/B 37/T 32/W 52/W 35/W 42/W 22/W LVM 033/064 039/058 033/061 031/055 029/044 028/046 028/055 31/B 26/T 24/W 53/W 35/J 32/W 22/W HDN 033/065 041/068 038/065 036/059 031/047 029/049 028/054 20/B 37/T 32/W 62/W 35/W 42/W 22/W MLS 031/057 038/067 038/061 035/055 029/045 027/045 026/049 32/W 24/T 31/B 62/W 24/W 42/W 22/W 4BQ 031/064 040/066 038/062 036/056 032/046 028/044 024/046 21/B 14/T 41/B 63/W 24/W 43/W 22/W BHK 027/050 032/061 035/055 031/050 027/041 023/041 023/043 33/W 13/T 31/B 64/W 33/W 33/J 22/W SHR 032/064 039/066 035/061 033/056 030/045 027/045 027/051 20/B 14/T 31/B 32/W 35/W 43/W 22/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1238 PM CDT TUE APR 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 316 AM CDT TUE APR 2 2013 TODAY...THE HIGH PLAINS DISTURBANCE OPERATING ON LIMITED MOISTURE WILL DRIFT VERY SLOWLY EAST SOUTHEAST TODAY AND TONIGHT. GIVEN THE DRY AIR AT THE LOWER LEVELS...SPRINKLES LOOKED REASONABLE ACROSS SWRN NEB. MID LEVEL CLOUDINESS WILL HANG ON TODAY AND TONIGHT ACROSS THE SOUTHWEST. ELSEWHERE...MOSTLY CLEAR. A WEAK AREA FOR FRONTOGENESIS HAS DEVELOPED ACROSS THE MISSOURI BASIN. THE RAP MODEL IS LIFTING THIS FEATURE UP INTO THE MIDWEST TODAY. OTHERWISE...A WARM FRONT SHOULD LIFT NORTH INTO THE SANDHILLS TODAY WHILE WINDS NORTH OF THE FRONT BACK TO THE EAST AND NORTHEAST. FULL SUN IN MANY AREAS SHOULD SEND HIGHS TO AROUND 60. THE RAP SUGGESTED LOWER 60S IN MANY AREAS BUT THAT MODEL TENDS TO RUN WARM. RH DROPS TO 20 TO 25 PERCENT THIS AFTERNOON BUT WINDS SHOULD REMAIN BELOW 15 MPH WITH WEAK WINDS CARRYING ALL THE WAY TO 700 MB. TONIGHT...LOW PRESSURE DEVELOPS ACROSS THE NRN HIGH PLAINS WHICH SETS UP A STRONGER SOUTHWEST WIND TONIGHT. THIS WILL HOLD LOWS AROUND FREEZING. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 316 AM CDT TUE APR 2 2013 12Z WEDNESDAY AND BEYOND. MAIN FORECAST CONCERN GOING IN THE EXTENDED PERIOD REVOLVES AROUND THE DEVELOPMENT OF AN AMPLIFIED WESTERN CONUS TROUGH...WHICH MAY BRING PERIODS OF WIDESPREAD PRECIPITATION BACK ACROSS THE CWA THIS WEEKEND AND ESPECIALLY EARLY NEXT WEEK. BUT FIRST...AN UPPER LOW AND ATTENDANT TROUGH THAT WILL BE POSITIONED ACROSS SOUTHEAST COLORADO/NORTHERN NEW MEXICO EARLY WEDNESDAY WILL PROGRESS SOUTHEAST ACROSS TEXAS AND THE SOUTHERN PLAINS THROUGH THURSDAY. THIS WILL ALLOW A TRANSITION FROM SPLIT FLOW ALOFT OVER THE CENTRAL PLAINS...TO NORTHWESTERLY...AND EVENTUALLY SOUTHWESTERLY AS A UPPER RIDGE BUILDS ACROSS THE PLAINS ON FRIDAY. AT THE SAME TIME...AN UPPER TROUGH AND ATTENDANT LOW WILL BE RAPIDLY PROGRESSING ACROSS THE CANADIAN ROCKIES TOWARD SOUTHERN ONTARIO...DRAGGING A COLD FRONT THROUGH THE NORTHERN/CENTRAL HIGH PLAINS EARLY ON THURSDAY. TEMPERATURES ON WEDNESDAY WILL BE ATYPICAL...WITH THE WARMEST READINGS ACROSS NORTHERN NEBRASKA...WHERE HIGHS IN THE LOW TO MID 60S SHOULD PREVAIL. FOR SOUTHERN NEBRASKA...HIGHS ON WEDNESDAY WILL BE SOME 5-8F COOLER AS THE INFLUENCE OF THE SOUTHERN PLAINS UPPER LOW SHOULD ALLOW FOR AN INCREASE CLOUDINESS AND SLIGHTLY COOLER TEMPERATURES ALOFT. SLIGHTLY COOLER ACROSS THE NORTH ON THURSDAY AS MODIFIED ARCTIC HIGH PRESSURE RECYCLES SOME COOLER AIR BACK INTO NORTH CENTRAL NEBRASKA...ANTICIPATING HIGHS MAINLY IN THE MID 50S. TEMPERATURES ACROSS THE SOUTH AND WEST WILL WARM SEVERAL DEGREES UNDER FULL SUN AND WEAK WARMING ALOFT...MID 60S SHOULD PREVAIL. FRIDAY WILL BE THE WARMEST DAY OF THE WEAK FOR ALL AREAS AS THE UPPER RIDGE AXIS SHIFTS EAST ACROSS THE CWA. THERE MAY BE FIRE CONCERNS AS SURFACE T/TDS SPREADS APPROACH 40F. SOUTHERLY WIND SPEEDS LOOK TO INCREASE AS WELL AS A SURFACE TROUGH OF LOW PRESSURE DEEPENS ACROSS THE HIGH PLAINS. BY EARLY SATURDAY...A WAVE WILL BE PASSING THROUGH THE NORTHERN PLAINS WITHIN NEAR ZONAL FLOW ALOFT...HOWEVER THE FORECAST MODELS SEEM TO BE KEYING ON MOST OF THE QPF REMOVED FROM THE CWA...THUS WILL MAINTAIN THE INHERITED SLIGHT CHANCE POPS FOR NOW AND NOT VENTURE ANY HIGHER. FOR SUNDAY AND EARLY NEXT WEEK...THE LONG RANGE SOLUTIONS ALL ARRIVE AT A SIGNIFICANT TROUGH ACROSS THE WESTERN CONUS...WITH THE POSSIBILITY OF SEVERAL WAVES IMPACTING THE CWA...FIRST OF WHICH ARRIVES ON SUNDAY. DIFFERENCES BETWEEN THE GFS AND EC ARE EVIDENT...MAINLY WITH THE TIMING AND EVOLUTION OF THE MEAN WESTERN CONUS TROUGH...BUT BOTH POINT TO A POTENTIALLY ACTIVE LATE WEEKEND/EARLY WORK WEEK SET UP. BOTH ALSO INDICATE THE POTENTIAL OF A MYRIAD OF PRECIPITATION...STARTING WITH TSTMS...SHOWERS...RAIN AND POSSIBLY SNOW. WITH THE POTENTIAL SYSTEM STILL WAY OUT...DIDN/T WANT TO GET TOO CUTE WITH PTYPE AND/OR LOCATIONS OF THE HIGHEST POPS. GENERALLY BROAD-BRUSHED 30-40% POPS SUNDAY AND MONDAY...WITH SHOWERS POSSIBLY CHANGING TO SNOW ACROSS THE NORTH LATE ON MONDAY...AND ACROSS THE ENTIRE CWA EARLY TUESDAY MORNING. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1238 PM CDT TUE APR 2 2013 NO AVIATION CONCERNS OVER THE NEXT 24 HOURS WITH VFR CONDITIONS EXPECTED TO PREVAIL AT BOTH KLBF AND KVTN. WINDS WILL STRENGTHEN OUT OF THE SOUTH TOMORROW MORNING...WITH WINDS GUSTING TO AROUND 20 KTS IN SOUTHERN NEBRASKA...TO AOA 25 KTS IN THE NORTH. CLOUD COVER SHOULD GENERALLY STAY SOUTH OF THE AREA INTO KANSAS AND COLORADO. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...MARTIN
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
620 AM CDT TUE APR 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 316 AM CDT TUE APR 2 2013 TODAY...THE HIGH PLAINS DISTURBANCE OPERATING ON LIMITED MOISTURE WILL DRIFT VERY SLOWLY EAST SOUTHEAST TODAY AND TONIGHT. GIVEN THE DRY AIR AT THE LOWER LEVELS...SPRINKLES LOOKED REASONABLE ACROSS SWRN NEB. MID LEVEL CLOUDINESS WILL HANG ON TODAY AND TONIGHT ACROSS THE SOUTHWEST. ELSEWHERE...MOSTLY CLEAR. A WEAK AREA FOR FRONTOGENESIS HAS DEVELOPED ACROSS THE MISSOURI BASIN. THE RAP MODEL IS LIFTING THIS FEATURE UP INTO THE MIDWEST TODAY. OTHERWISE...A WARM FRONT SHOULD LIFT NORTH INTO THE SANDHILLS TODAY WHILE WINDS NORTH OF THE FRONT BACK TO THE EAST AND NORTHEAST. FULL SUN IN MANY AREAS SHOULD SEND HIGHS TO AROUND 60. THE RAP SUGGESTED LOWER 60S IN MANY AREAS BUT THAT MODEL TENDS TO RUN WARM. RH DROPS TO 20 TO 25 PERCENT THIS AFTERNOON BUT WINDS SHOULD REMAIN BELOW 15 MPH WITH WEAK WINDS CARRYING ALL THE WAY TO 700 MB. TONIGHT...LOW PRESSURE DEVELOPS ACROSS THE NRN HIGH PLAINS WHICH SETS UP A STRONGER SOUTHWEST WIND TONIGHT. THIS WILL HOLD LOWS AROUND FREEZING. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 316 AM CDT TUE APR 2 2013 12Z WEDNESDAY AND BEYOND. MAIN FORECAST CONCERN GOING IN THE EXTENDED PERIOD REVOLVES AROUND THE DEVELOPMENT OF AN AMPLIFIED WESTERN CONUS TROUGH...WHICH MAY BRING PERIODS OF WIDESPREAD PRECIPITATION BACK ACROSS THE CWA THIS WEEKEND AND ESPECIALLY EARLY NEXT WEEK. BUT FIRST...AN UPPER LOW AND ATTENDANT TROUGH THAT WILL BE POSITIONED ACROSS SOUTHEAST COLORADO/NORTHERN NEW MEXICO EARLY WEDNESDAY WILL PROGRESS SOUTHEAST ACROSS TEXAS AND THE SOUTHERN PLAINS THROUGH THURSDAY. THIS WILL ALLOW A TRANSITION FROM SPLIT FLOW ALOFT OVER THE CENTRAL PLAINS...TO NORTHWESTERLY...AND EVENTUALLY SOUTHWESTERLY AS A UPPER RIDGE BUILDS ACROSS THE PLAINS ON FRIDAY. AT THE SAME TIME...AN UPPER TROUGH AND ATTENDANT LOW WILL BE RAPIDLY PROGRESSING ACROSS THE CANADIAN ROCKIES TOWARD SOUTHERN ONTARIO...DRAGGING A COLD FRONT THROUGH THE NORTHERN/CENTRAL HIGH PLAINS EARLY ON THURSDAY. TEMPERATURES ON WEDNESDAY WILL BE ATYPICAL...WITH THE WARMEST READINGS ACROSS NORTHERN NEBRASKA...WHERE HIGHS IN THE LOW TO MID 60S SHOULD PREVAIL. FOR SOUTHERN NEBRASKA...HIGHS ON WEDNESDAY WILL BE SOME 5-8F COOLER AS THE INFLUENCE OF THE SOUTHERN PLAINS UPPER LOW SHOULD ALLOW FOR AN INCREASE CLOUDINESS AND SLIGHTLY COOLER TEMPERATURES ALOFT. SLIGHTLY COOLER ACROSS THE NORTH ON THURSDAY AS MODIFIED ARCTIC HIGH PRESSURE RECYCLES SOME COOLER AIR BACK INTO NORTH CENTRAL NEBRASKA...ANTICIPATING HIGHS MAINLY IN THE MID 50S. TEMPERATURES ACROSS THE SOUTH AND WEST WILL WARM SEVERAL DEGREES UNDER FULL SUN AND WEAK WARMING ALOFT...MID 60S SHOULD PREVAIL. FRIDAY WILL BE THE WARMEST DAY OF THE WEAK FOR ALL AREAS AS THE UPPER RIDGE AXIS SHIFTS EAST ACROSS THE CWA. THERE MAY BE FIRE CONCERNS AS SURFACE T/TDS SPREADS APPROACH 40F. SOUTHERLY WIND SPEEDS LOOK TO INCREASE AS WELL AS A SURFACE TROUGH OF LOW PRESSURE DEEPENS ACROSS THE HIGH PLAINS. BY EARLY SATURDAY...A WAVE WILL BE PASSING THROUGH THE NORTHERN PLAINS WITHIN NEAR ZONAL FLOW ALOFT...HOWEVER THE FORECAST MODELS SEEM TO BE KEYING ON MOST OF THE QPF REMOVED FROM THE CWA...THUS WILL MAINTAIN THE INHERITED SLIGHT CHANCE POPS FOR NOW AND NOT VENTURE ANY HIGHER. FOR SUNDAY AND EARLY NEXT WEEK...THE LONG RANGE SOLUTIONS ALL ARRIVE AT A SIGNIFICANT TROUGH ACROSS THE WESTERN CONUS...WITH THE POSSIBILITY OF SEVERAL WAVES IMPACTING THE CWA...FIRST OF WHICH ARRIVES ON SUNDAY. DIFFERENCES BETWEEN THE GFS AND EC ARE EVIDENT...MAINLY WITH THE TIMING AND EVOLUTION OF THE MEAN WESTERN CONUS TROUGH...BUT BOTH POINT TO A POTENTIALLY ACTIVE LATE WEEKEND/EARLY WORK WEEK SET UP. BOTH ALSO INDICATE THE POTENTIAL OF A MYRIAD OF PRECIPITATION...STARTING WITH TSTMS...SHOWERS...RAIN AND POSSIBLY SNOW. WITH THE POTENTIAL SYSTEM STILL WAY OUT...DIDN/T WANT TO GET TOO CUTE WITH PTYPE AND/OR LOCATIONS OF THE HIGHEST POPS. GENERALLY BROAD-BRUSHED 30-40% POPS SUNDAY AND MONDAY...WITH SHOWERS POSSIBLY CHANGING TO SNOW ACROSS THE NORTH LATE ON MONDAY...AND ACROSS THE ENTIRE CWA EARLY TUESDAY MORNING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 620 AM CDT TUE APR 2 2013 VFR IS EXPECTED ALL AREAS TODAY AND TONIGHT. MIDLEVEL CLOUDINESS ACROSS THE CNTL ROCKIES WILL SPREAD EAST TODAY AND TONIGHT AFFECTING AREAS GENERALLY SOUTH OF INTERSTATE 80. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
316 AM CDT TUE APR 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 316 AM CDT TUE APR 2 2013 TODAY...THE HIGH PLAINS DISTURBANCE OPERATING ON LIMITED MOISTURE WILL DRIFT VERY SLOWLY EAST SOUTHEAST TODAY AND TONIGHT. GIVEN THE DRY AIR AT THE LOWER LEVELS...SPRINKLES LOOKED REASONABLE ACROSS SWRN NEB. MID LEVEL CLOUDINESS WILL HANG ON TODAY AND TONIGHT ACROSS THE SOUTHWEST. ELSEWHERE...MOSTLY CLEAR. A WEAK AREA FOR FRONTOGENESIS HAS DEVELOPED ACROSS THE MISSOURI BASIN. THE RAP MODEL IS LIFTING THIS FEATURE UP INTO THE MIDWEST TODAY. OTHERWISE...A WARM FRONT SHOULD LIFT NORTH INTO THE SANDHILLS TODAY WHILE WINDS NORTH OF THE FRONT BACK TO THE EAST AND NORTHEAST. FULL SUN IN MANY AREAS SHOULD SEND HIGHS TO AROUND 60. THE RAP SUGGESTED LOWER 60S IN MANY AREAS BUT THAT MODEL TENDS TO RUN WARM. RH DROPS TO 20 TO 25 PERCENT THIS AFTERNOON BUT WINDS SHOULD REMAIN BELOW 15 MPH WITH WEAK WINDS CARRYING ALL THE WAY TO 700 MB. TONIGHT...LOW PRESSURE DEVELOPS ACROSS THE NRN HIGH PLAINS WHICH SETS UP A STRONGER SOUTHWEST WIND TONIGHT. THIS WILL HOLD LOWS AROUND FREEZING. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 316 AM CDT TUE APR 2 2013 12Z WEDNESDAY AND BEYOND. MAIN FORECAST CONCERN GOING IN THE EXTENDED PERIOD REVOLVES AROUND THE DEVELOPMENT OF AN AMPLIFIED WESTERN CONUS TROUGH...WHICH MAY BRING PERIODS OF WIDESPREAD PRECIPITATION BACK ACROSS THE CWA THIS WEEKEND AND ESPECIALLY EARLY NEXT WEEK. BUT FIRST...AN UPPER LOW AND ATTENDANT TROUGH THAT WILL BE POSITIONED ACROSS SOUTHEAST COLORADO/NORTHERN NEW MEXICO EARLY WEDNESDAY WILL PROGRESS SOUTHEAST ACROSS TEXAS AND THE SOUTHERN PLAINS THROUGH THURSDAY. THIS WILL ALLOW A TRANSITION FROM SPLIT FLOW ALOFT OVER THE CENTRAL PLAINS...TO NORTHWESTERLY...AND EVENTUALLY SOUTHWESTERLY AS A UPPER RIDGE BUILDS ACROSS THE PLAINS ON FRIDAY. AT THE SAME TIME...AN UPPER TROUGH AND ATTENDANT LOW WILL BE RAPIDLY PROGRESSING ACROSS THE CANADIAN ROCKIES TOWARD SOUTHERN ONTARIO...DRAGGING A COLD FRONT THROUGH THE NORTHERN/CENTRAL HIGH PLAINS EARLY ON THURSDAY. TEMPERATURES ON WEDNESDAY WILL BE ATYPICAL...WITH THE WARMEST READINGS ACROSS NORTHERN NEBRASKA...WHERE HIGHS IN THE LOW TO MID 60S SHOULD PREVAIL. FOR SOUTHERN NEBRASKA...HIGHS ON WEDNESDAY WILL BE SOME 5-8F COOLER AS THE INFLUENCE OF THE SOUTHERN PLAINS UPPER LOW SHOULD ALLOW FOR AN INCREASE CLOUDINESS AND SLIGHTLY COOLER TEMPERATURES ALOFT. SLIGHTLY COOLER ACROSS THE NORTH ON THURSDAY AS MODIFIED ARCTIC HIGH PRESSURE RECYCLES SOME COOLER AIR BACK INTO NORTH CENTRAL NEBRASKA...ANTICIPATING HIGHS MAINLY IN THE MID 50S. TEMPERATURES ACROSS THE SOUTH AND WEST WILL WARM SEVERAL DEGREES UNDER FULL SUN AND WEAK WARMING ALOFT...MID 60S SHOULD PREVAIL. FRIDAY WILL BE THE WARMEST DAY OF THE WEAK FOR ALL AREAS AS THE UPPER RIDGE AXIS SHIFTS EAST ACROSS THE CWA. THERE MAY BE FIRE CONCERNS AS SURFACE T/TDS SPREADS APPROACH 40F. SOUTHERLY WIND SPEEDS LOOK TO INCREASE AS WELL AS A SURFACE TROUGH OF LOW PRESSURE DEEPENS ACROSS THE HIGH PLAINS. BY EARLY SATURDAY...A WAVE WILL BE PASSING THROUGH THE NORTHERN PLAINS WITHIN NEAR ZONAL FLOW ALOFT...HOWEVER THE FORECAST MODELS SEEM TO BE KEYING ON MOST OF THE QPF REMOVED FROM THE CWA...THUS WILL MAINTAIN THE INHERITED SLIGHT CHANCE POPS FOR NOW AND NOT VENTURE ANY HIGHER. FOR SUNDAY AND EARLY NEXT WEEK...THE LONG RANGE SOLUTIONS ALL ARRIVE AT A SIGNIFICANT TROUGH ACROSS THE WESTERN CONUS...WITH THE POSSIBILITY OF SEVERAL WAVES IMPACTING THE CWA...FIRST OF WHICH ARRIVES ON SUNDAY. DIFFERENCES BETWEEN THE GFS AND EC ARE EVIDENT...MAINLY WITH THE TIMING AND EVOLUTION OF THE MEAN WESTERN CONUS TROUGH...BUT BOTH POINT TO A POTENTIALLY ACTIVE LATE WEEKEND/EARLY WORK WEEK SET UP. BOTH ALSO INDICATE THE POTENTIAL OF A MYRIAD OF PRECIPITATION...STARTING WITH TSTMS...SHOWERS...RAIN AND POSSIBLY SNOW. WITH THE POTENTIAL SYSTEM STILL WAY OUT...DIDN/T WANT TO GET TOO CUTE WITH PTYPE AND/OR LOCATIONS OF THE HIGHEST POPS. GENERALLY BROAD-BRUSHED 30-40% POPS SUNDAY AND MONDAY...WITH SHOWERS POSSIBLY CHANGING TO SNOW ACROSS THE NORTH LATE ON MONDAY...AND ACROSS THE ENTIRE CWA EARLY TUESDAY MORNING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1241 AM CDT TUE APR 2 2013 UNLIMITED CEILING AND VISIBILITY CAN BE EXPECTED TONIGHT THROUGH LATE TUESDAY EVENING IN CENTRAL AND WESTERN NEBRASKA. EVEN WITH LIGHT EAST TO SOUTHEAST WIND...MOISTURE IS CONFINED TO VERY NEAR THE SURFACE...AS CAN BE SEEN IN THE LBF SOUNDING...AND IS NOT LIKELY TO HAVE ENOUGH DEPTH FOR THE FORMATION OF FOG. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
325 AM CDT TUE APR 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 324 AM CDT TUE APR 2 2013 FORECAST CHALLENGE CONCERNS MAINLY CLOUD TRENDS AND TEMPERATURES. MODELS CLOSE IN THE SHORT TERM AND WILL BLEND. WEAK SHORT WAVE TO DROP THROUGH MID LEVEL NORTHERLY FLOW TODAY. SATELLITE IMAGERY INDICATING MOST ORGANIZED CLOUD COVER WITH WAVE TO DROP THROUGH WESTERN/CENTRAL ND. WITH SURFACE HIGH PRESSURE IN PLACE WILL MAINTAIN DRY FORECAST. WILL SEE SOME CLOUD COVER MAINLY FIRST HALF OF THE DAY THEN MORE SOLAR. COLUMN DOES WARM A TAD BUT WITH EARLY CLOUDS FEEL TEMPERATURES WILL TURN OUT FAIRLY CLOSE TO YESTERDAY. AS SURFACE HIGH SHIFTS EAST TONIGHT WILL SEE INCREASED MIXING AND WARM ADVECTION. THIS WILL HOLD TEMPERATURES UP WITH COOLEST AREAS ACROSS THE FAR EAST WHICH WILL BE THE LAST AREA TO SEE ABOVE CONDITIONS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 324 AM CDT TUE APR 2 2013 NEXT COLD FRONT TO DROP THROUGH FA WEDNESDAY. BASED ON TIMING OF BOUNDARY AT THIS POINT APPEARS THAT WHAT PCPN DOES OCCUR SHOULD INITIALLY BE LT RAIN WITH SOME PHASE ISSUES POSSIBLE DURING THE EVENING ACROSS THE NORTHERN FA. MODELS SHOWING DIFFERENCES ON THERMAL FIELDS AND PCPN POTENTIAL SO DID NOT MAKE ANY SIGNIFICANT CHANGES. LOOKS TO BE THE WARMEST DAY OF THE WEEK WITH CLOUD TRENDS INFLUENCING JUST HOW WARM WE GET. PCPN SHOULD WIND DOWN FROM WEST TO EAST DURING THE EVENING. HIGH PRESSURE BUILDS IN THURSDAY FOR DRY BUT COOLER TEMPERATURES. FOCUS WILL BE ON THE EASTERN PACIFIC WAVE THAT MOVES ACROSS THE NORTHERN TIER STATES FRIDAY AND SATURDAY. MODEL CONSENSUS IS STILL POOR WITH THE 00 UTC ECMWF STILL FARTHER NORTH...WARMER AND SLOWER COMPARED TO THE GFS...WHICH IS MORE SIMILAR TO THE DGEX AND GEM. STILL BEING 3 TO 4 DAYS OUT...WILL FAVOR A BLENDED SOLUTION...WHICH PLACES BEST CHANCE FOR ACCUMULATING PRECIPITATION (RAIN/SNOW MIX) ACROSS THE SOUTHERN FORECAST AREA WHERE 0.5 TO 0.75 INCHES LIQUID EQUIVALENT IS POSSIBLE. THE GFS SOLUTION WOULD RESULT IN MORE SNOW...WHEREAS THE WARMER ECMWF WOULD BE MOSTLY RAIN. SUNDAY SHOULD BE MOSTLY DRY WITH ANOTHER SHOT OF PRECIPITATION ON MONDAY IN ADVANCE OF THE NEXT UPPER LOW DIGGING ACROSS THE CENTRAL ROCKIES. DAY-TO-DAY TEMPERATURE CHANGES WILL BE MINIMAL WITH DAYTIME HIGHS IN THE 30S TO LOWER 40S AND NIGHTTIME LOWS IN THE 20S TO LOWER 30S. OVERALL...NO MAJOR AIR MASS CHANGES IN THE NEXT SEVEN DAYS...KEEPING TEMPERATURES WELL BELOW EARLY APRIL NORMALS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1150 PM CDT MON APR 1 2013 THERE IS A WEAK SHORTWAVE THAT WILL PASS THROUGH THE REGION OVERNIGHT AND INCREASE CLOUD COVER. NOT SURE HOW WIDESPREAD THE CLOUDS WILL BE...OR EXACTLY HOW LOW. JUDGING FROM UPSTREAM SATELLITE IMAGERY AND RAP GUIDANCE...THERE WILL LIKELY BE A PERIOD OF BKN CIGS IN THE LOW VFR RANGE (ESPECIALLY ALONG AND WEST OF THE RED RIVER VALLEY). && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...VOELKER LONG TERM...ROGERS AVIATION...TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1248 AM CDT TUE APR 2 2013 .UPDATE... ISSUED AT 1247 AM CDT TUE APR 2 2013 NO SIGNIFICANT CHANGES WERE REQUIRED WITH THIS FORECAST UPDATE AS THE INHERITED FORECAST FOR THE REMAINDER OF THE NIGHT IS WELL ON TRACK AND BLENDED TO OBSERVED TRENDS THROUGH 530 UTC. THE ONLY QUESTION FOR THE REMAINDER OF THE NIGHT IS HOW FAR INTO NORTHERN NORTH DAKOTA EXPANDING STRATUS IN SOUTHEAST SASKATCHEWAN WILL BE ABLE TO REACH. WILL FOLLOW CLOSELY TO THE 04 UTC RAP FOR LOW LEVEL MOISTURE FIELDS FOR THE REMAINDER OF THE NIGHT AS IT CURRENTLY HAS A GOOD DEPICTION OF THE STRATUS FIELD. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 346 PM CDT MON APR 1 2013 HIGH PRESSURE WILL GRADUALLY SHIFT EAST OF THE REGION THROUGH THE PERIOD. DRY CONDITIONS WILL PREVAIL AS A RESULT. BELOW NORMAL TEMPERATURES WILL CONTINUE THIS AFTERNOON AND TONIGHT. HOWEVER...RETURN FLOW DEVELOPING ACROSS THE REGION COMBINED WITH NO SNOW PACK SOUTHWEST OF THE MISSOURI WILL ALLOW TUESDAY AFTERNOON HIGHS TO BE ABOVE NORMAL SOUTHWEST. BELOW NORMAL TEMPERATURES WILL CONTINUE NORTH AND EAST OF THE MISSOURI RIVER...WHERE THE SNOW PACK IS LOCATED. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 346 PM CDT MON APR 1 2013 THE MAIN FORECAST CHALLENGES FOR THE EXTENDED PERIOD INCLUDE PRECIPITATION CHANCES AND PRECIPITATION TYPE. 12Z SUITE OF MODEL SOLUTIONS ARE IN AGREEMENT EARLY IN THE PERIOD...WITH SOLUTIONS DIVERGING LATE THIS WEEK. WARM AIR ADVECTION WILL CONTINUE ACROSS THE AREA TUESDAY NIGHT AND WEDNESDAY AHEAD OF A UPPER LEVEL WAVE/SURFACE LOW PRESSURE SYSTEM THAT IS FORECAST TO PASS OVER NORTH DAKOTA. WARM H850 TEMPERATURES OF +6 TO +10C WILL BE FIRMLY IN PLACE WEDNESDAY AS PRECIPITATION BEGINS ACROSS THE NORTHWEST AND SPREADS SOUTHEAST ACROSS THE AREA WEDNESDAY. PRECIPITATION WILL BEGIN AS LIGHT FREEZING RAIN AND TRANSITION TO LIGHT RAIN DURING WEDNESDAY AFTERNOON. ACROSS THE SOUTHWEST...ISOLATED WEAK THUNDERSTORMS ARE POSSIBLE...WHERE TEMPERATURES WILL BE IN THE 60S WITH SURFACE BASED CAPE IN THE 100 TO 200 J/KG ADVERTISED BY THE 12Z NAM. BEFORE ENDING WEDNESDAY EVENING...A TRANSITION FROM LIGHT RAIN TO A WINTRY MIX OF SNOW...FREEZING RAIN...AND POSSIBLY SLEET WILL BE SEEN AS A COLD FRONT MOVES SOUTH FROM CANADA. COOLER TEMPERATURES WILL BE SEEN WEDNESDAY NIGHT AND THURSDAY...AS COLD AIR COMMENCES FOLLOWING THE PASSAGE OF THE AFOREMENTIONED COLD FRONT. HOWEVER...ACROSS THE SNOW LESS AREAS...TEMPERATURES WILL BE WARMEST WITH TEMPERATURES IN 50S ON THURSDAY. FOR LOCATIONS ACROSS THE SNOWPACK...TEMPERATURES WILL BE IN THE LOW TO MID 30S. STARTING FRIDAY...AN ACTIVE PERIOD OF WEATHER IS EXPECTED TO START AS A SERIES OF UPPER LEVEL WAVES AND THEIR SURFACE REFLECTIONS ARE PROGGED TO MOVE ACROSS THE AREA IN NORTHWESTERLY FLOW. UNCERTAINTY REMAINS IN THE PLACEMENT AND TYPE OF PRECIPITATION ACROSS NORTH DAKOTA...AS THERE IS DISAGREEMENT AMONGST THE 12Z MODEL SOLUTIONS. THE 12Z GEM/GFS ARE MORE AGGRESSIVE WITH QPF ACROSS THE WEST AND CENTRAL VERSUS THE 12Z EC SOLUTION. THE 12Z EC KEEPS THE BULK OF THE PRECIPITATION FURTHER NORTH ACROSS SOUTHERN MANITOBA AND SASKATCHEWAN. AT THIS TIME HAVE UTILIZED A BLEND OF MODEL SOLUTIONS DURING THE FRIDAY TO MONDAY PERIOD...WHICH GIVE A WIDE ARRAY OF PRECIPITATION TYPES. AT THIS MOMENT...IT LOOKS LIKE THE SOUTHWEST WILL REMAIN MOSTLY RAIN AS IT REMAINS IN THE WARM H850 TEMPERATURES OF +4 TO +8 C. ELSEWHERE...A LIGHT WINTRY MIX OF SNOW...FREEZING RAIN...AND POSSIBLY SLEET MAY OCCUR. BY SUNDAY EVENING AND MONDAY...PRECIPITATION TYPE WILL BE SNOW...AS ANOTHER COLD FRONT DROPS SOUTH OUT OF CANADA. FOLLOWING THE PASSAGE OF THE COLD FRONT...COLDER H850 TEMPERATURES OF -8 TO -12 C ARE POSSIBLE AT THE BEGINNING OF NEXT WEEK...AS A SURFACE HIGH PRESSURE STARTS TO MOVE SOUTH. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)... ISSUED AT 1247 AM CDT TUE APR 2 2013 VFR CONDITIONS ARE FORECAST FOR THE 06 UTC TAF PERIOD ACROSS WESTERN AND CENTRAL NORTH DAKOTA WITH HIGH PRESSURE IN PLACE. THERE IS THE POTENTIAL THAT AN EXPANDING STRATUS FIELD ACROSS SOUTHEAST SASKATCHEWAN AS OF 530 UTC MAY APPROACH THE KMOT TERMINAL. DUE TO UNCERTAINTY CODED AS A TEMPO GROUP FOR MVFR CEILINGS BETWEEN 8 AND 11 UTC AND WILL MONITOR SATELLITE TRENDS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...TM LONG TERM...LTH AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1150 PM CDT MON APR 1 2013 .UPDATE... ISSUED AT 1150 PM CDT MON APR 1 2013 NO UPDATE NEEDED AT THIS POINT AS CURRENT FORECAST IS ON TRACK WITH PREVIOUS THINKING (SEE 945 PM UPDATE). UPDATE ISSUED AT 945 PM CDT MON APR 1 2013 SHORTWAVE AND ASSOCIATED CLOUDS CONTINUE TO APPROACH THE REGION FROM THE NORTHWEST. TIMED CLOUDY SKIES INTO THE FA BY LATER TONIGHT AND INTO TUESDAY MORNING. SOME FLURRIES REPORTED UPSTREAM...BUT MODELS DRY THIS ACTIVITY AS IT APPROACHES. NO CHANGES NEEDED TO MIN TEMPS AS ANY CLOUD COVER WILL ARRIVE WELL AFTER MIDNIGHT. MINOR ADJUSTMENTS TO THE HOURLY TEMPERATURE GRIDS ACROSS THE FAR NW FA TO ACCOUNT FOR CLOUDS ARRIVING JUST BEFORE SUNRISE. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 317 PM CDT MON APR 1 2013 TONIGHT...MAIN FORECAST CHALLENGE WILL BE CLOUDS AND TEMPS. MODELS SEEM TO BE IN FAIR AGREEMENT SO WILL CONTINUE TO USE A MODEL BLEND. NEVER SAW MUCH FOR CLOUD DEVELOPMENT TODAY SO WILL START OFF THE NIGHT NEARLY CLOUD FREE. THERE IS AN UPSTREAM WAVE OVER CENTRAL SASKATCHEWAN WITH SOME CLOUDS AND EVEN SOME FLURRIES OR LIGHT SNOW ASSOCIATED WITH IT. AMERICAN MODELS HAD BEEN TRYING TO HOLD SOME OF THIS LIGHT PCPN TOGETHER ALL THE WAY INTO THE NORTHERN FA LATE. 12Z RUNS OF THE NAM/GFS STILL HOLD IT TOGETHER BUT SEEM TO ERODE IT EITHER BEFORE IT GETS INTO OUR FA...WHILE THE ECMWF REMAINS DRY. THEREFORE WILL KEEP THE FORECAST DRY TONIGHT. AS FAR AS TEMPS GO SFC HIGH PRESSURE STILL REMAINS OVER THE FA WITH SOME PRETTY LIGHT WINDS. WILL STICK WITH LOWS TONIGHT FAIRLY SIMILAR TO THOSE FROM THIS MORNING. TUE...SFC HIGH REMAINS IN CLOSE PROXIMITY TO THE RED RIVER VALLEY KEEPING WINDS ON THE LOW SIDE AGAIN. LINGERING CLOUD COVER MAY HAVE SOME INFLUENCE ON HIGHS FOR THE DAY. GENERALLY KEPT HIGHS ABOUT 5F WARMER THAN TODAY. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 317 PM CDT MON APR 1 2013 TUE NIGHT-THU...WED IS STILL ON TRACK TO BE THE WARMEST DAY OF THE WEEK WITH 850MB TEMPS REACHING UP INTO THE +6C TO +8C RANGE OVER PORTIONS OF THE FA WITH A LITTLE STEADIER SOUTH WINDS. MAYBE NOT THE BEST DIRECTION FOR REALLY GOOD WARMING BUT AS THE COLD FRONT COMES THRU THEY SHOULD SWITCH TO THE WEST THEN NW. STILL LOOKS LIKE A LITTLE BIT OF PCPN WILL COME THROUGH WITH THE COLD FRONT BUT TRIED TO NARROW DOWN THE WINDOW A BIT BETTER. SHOULD REALLY BE A QUICK SHOT ALONG THE FRONT AND TEMPS SHOULD BE WARM ENOUGH TO KEEP ANY PCPN IN THE LIQUID FORM UNLESS MORE PCPN LINGERS BEHIND THE FRONT. THU WOULD BE COOLER BEHIND THE FRONT. THU NIGHT-MON...AN ENERGETIC JET STREAM WITH SOMEWHAT FLATTENED LONGWAVE RIDGE PATTERN IN THE LATE WEEK THEN TRANSITIONS TO A BROAD WESTERN TROF OVER THE WEEKEND. THIS PRODUCES A BRIEF RETURN TO NORTHWEST MID LEVEL FLOW OVER THE AREA ON THURSDAY AND A SUBTLE /FEW DEGREE/ COOL DOWN BEHIND A SURFACE COLD FRONT. A RETURN SOUTHERLY BLAYER FLOW IS EXPECTED ON FRIDAY... WITH ALL LONG RANGE MODELS ANTICIPATING THE ADVANCE OF A COLORADO LOW INTO THE CENTRAL AND NORTHERN PLAINS BY SATURDAY. A RAIN/SNOW MIX LOOKS QUITE PROBABLE FOR MUCH OF THE AREA FROM FRIDAY EVENING INTO SATURDAY... WITH A SOMEWHAT COOLER AND DRIER PATTERN ON SUNDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1150 PM CDT MON APR 1 2013 THERE IS A WEAK SHORTWAVE THAT WILL PASS THROUGH THE REGION OVERNIGHT AND INCREASE CLOUD COVER. NOT SURE HOW WIDESPREAD THE CLOUDS WILL BE...OR EXACTLY HOW LOW. JUDGING FROM UPSTREAM SATELLITE IMAGERY AND RAP GUIDANCE...THERE WILL LIKELY BE A PERIOD OF BKN CIGS IN THE LOW VFR RANGE (ESPECIALLY ALONG AND WEST OF THE RED RIVER VALLEY). && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...TG SHORT TERM...GODON LONG TERM...GUST AVIATION...TG
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1223 AM CDT TUE APR 2 2013 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...CIG MAY BE A BIT INTERMITTENT NEAR THE COAST BUT A PREDOMINANT MVFR LAYER AT ABOUT 1100 TO 1300 FT IS EXPECTED FOR THE NEXT FEW HOURS. NEAR THE COAST TEMPORARY DROPS TO ABOUT 800FT WILL BE POSSIBLE AROUND SUNRISE. MVFR CIGS NEAR THE COAST THROUGH MOST OF THE MORNING HOURS LIKELY SCATTERING OUT IN THE AFTERNOON. VFR WILL OCCUR EARLIER INLAND. WINDS WILL BE MODERATE OUT OF THE EAST TO SOUTHEAST. THERE IS A SMALL CHANCE FOR SHOWERS OR THUNDERSTORMS...MAINLY OVER THE BRUSH COUNTRY BUT LEFT THOSE OUT OF THE TAFS FOR NOW. LOWERING CIGS EXPECTED AGAIN TUESDAY NIGHT. /68-JGG/ && .PREV DISCUSSION... /ISSUED 208 PM CDT MON APR 1 2013/ SHORT TERM /NOW THROUGH TUESDAY NIGHT/...THE AREA REMAINS IN QUASI-ZONAL FLOW ALOFT WITH AN UPPER LEVEL TROUGH LOCATED OVER THE GREAT BASIN AND A WEAK IMPULSE RIDING WESTERLY FLOW IN NORTHERN MEXICO SOUTH OF THE TEXAS BIG BEND. AT THE SURFACE...SOUTHEASTERLY FLOW CONTINUES TO ADVECT MOISTURE FROM THE GULF OF MEXICO WITH A COLD FRONT LOCATED ACROSS OKLAHOMA AND THE TEXAS PANHANDLE. A 1020MB HIGH IS LOCATED ACROSS THE ARKLAMISS. FOR THE REST OF THE AFTERNOON AND INTO THIS EVENING...WILL CONTINUE TO SEE CLOUDS BREAK UP AS MIXING AND DAYTIME HEATING CONTINUES. THICKER STRATOCU RESIDES OVER ZAPATA/JIM HOGG/STARR COUNTIES AND MAY BE A LITTLE HARDER TO BREAK UP CLOUDS IN THIS AREA. EVEN THOUGH THICK CLOUDS ARE LOCATED HERE...TEMPERATURES HAVE WARMED NICELY AND ARE ACTUALLY ABOVE FORECASTED HOURLY TEMPERATURES BUT LOOK GOOD FOR THE HIGHS THIS AFTERNOON. WEAK IMPULSE TO OUR WEST IS FORECAST TO SPARK CONVECTION ON THE SIERRA MADRE LATER THIS AFTERNOON AS IT MOVES EAST. LATEST HRRR AND SPC 4KM WRF CONTINUE TO ROLL CONVECTION OFF THE HIGHER TERRAIN AND MAKE A RUN AT OUR WESTERN ZONES. CURRENT 20 POPS OUT WEST LOOK GOOD FOR THIS EVENING AND MADE ONLY MINOR ADJUSTMENTS TO MOVE JUST A LITTLE EASTWARD. ANY STORMS THAT DO CREEP INTO OUR AREA WILL QUICKLY DISSIPATE TOWARDS MID EVENING AS BOUNDARY LEVEL STABILIZES. FOR TONIGHT...LOW CLOUDS WILL MOVE BACK IN ON SOUTHEASTERLY LOW LEVEL WINDS BY MID TO LATE EVENING. NAM12/RAP/HRRR SHOW SIGNALS OF SEA FOG DEVELOPING AND/OR ADVECTING IN TO THE COASTAL AREAS OVERNIGHT. ADDED AREAS OF FOG ALONG THE COASTLINE WITH PATCHY FOG INLAND. WILL HOLD OFF ON ANY DENSE FOG ADVISORY AT THIS TIME AND LET SWING SHIFT MAKE THE CALL. INCREASED LOW TEMPERATURES SLIGHTLY WITH EXPECTED ABUNDANCE OF LOW CLOUDS AND LOOKING AT MAINLY UPPER 60S TO LOWER 70S. FOR TUESDAY...WE WILL START OUT WITH THOSE LOW CLOUDS AND WILL BREAK OUT AND DISSIPATE BY LATE MORNING. MIXING WILL TAKE PLACE BY MID MORNING WITH GUSTY WINDS BY LATE MORNING. ANOTHER IMPULSE IS PROGGED TO MOVE ACROSS THE AREA EARLY TUESDAY AFTERNOON. THERE IS PLACEMENT ISSUES BETWEEN THE NAM AND GFS WITH THE NAM FURTHER NORTH AND THE GFS IS ACROSS THE NORTHERN PORTION OF THE AREA AND IS WEAKER THAN THE PREVIOUS RUN. KEPT POPS AS IS AND JUST TWEAKED LOCATION BASED ON 12Z GFS. A STRONG TO SEVERE STORM IS POSSIBLE GIVEN THE THERMODYNAMIC ENVIRONMENT. FOR TUESDAY NIGHT...THAT IMPULSE IS WELL NORTH OF THE AREA WITH JUST A FEW SHOWERS LEFT OVER IN THE COASTAL WATERS. ATMOSPHERE WILL STABILIZE RATHER RAPIDLY AFTER SUNSET WITH SKIES BECOMING CLOUDY ONCE AGAIN. COLD FRONT WILL SAG INTO NORTH CENTRAL TEXAS WITH A SFC LOW SOUTH OF THE TEXAS BIG BEND. CLOUDS WILL KEEP LOWS UP...COMPARABLE TO TONIGHT. LONG TERM /WEDNESDAY THROUGH MONDAY/...12Z MODEL RUN REMAINS PERSISTENT ON THE TRACK AND STRENGTH OF THE MID TO UPPER LEVEL TROUGH CURRENTLY OVER THE GREAT BASIN. BY 18Z WEDNESDAY GFS PLACES THE UPPER TROUGH AXIS ACROSS NORTHWEST TEXAS AROUND 18Z WITH ITS ASSOCIATED COLD FRONT APPROACHING THE NORTHERN PORTIONS OF THE CWA. LARGE SCALE ASCENT COUPLED WITH LOW LEVEL CONVERGENCE ALONG THE FRONT SHOULD BE THE COMBINATION NEEDED TO BRING ABOUT THE CHANCE OF RAIN WE HAVE SEEN IN A WHILE. MODEST LOW LEVEL MOISTURE WILL BE IN PLACE AND A LATE AFTERNOON FRONTAL PASSAGE SHOULD ALLOW FOR SURFACE HEATING TO EXCEED GUIDANCE VALUES. SPC MAINTAINS GENERAL THUNDERSTORM CHANCES FOR WEDNESDAY BUT CAN NOT RULE OUT ISOLATED SEVERE STORMS AS THE ATMOSPHERE BECOMES INCREASINGLY UNSTABLE. A DAY TO DAY ANALYSIS TO TAKE PLACE BEFORE WE ADD SEVERE WORDING INTO THE FORECAST/GRIDS. POP GUIDANCE REMAINS AT LOW END CHANCE BUT THIS MIGHT BE ON THE LOW END WITH DYNAMICS LOOKING A BETTER THEN YESTERDAY AT THIS TIME. KEEP WED AND WEDNESDAY NIGHT POPS CLOSE TO THE PREVIOUS FORECAST. AS MENTIONED TEMPERATURES SHOULD CLIMB AHEAD OF THE COLD FRONT WITH A LATE AFTERNOON OR EARLY EVENING PASSAGE. FORECAST HIGHS TO REMAIN ABOVE GUIDANCE VALUES ESPECIALLY IF WE SEE MORE SUN PEAK THROUGH. TROUGH AXIS AND SURFACE LOW PRESSURE QUICKLY EXITS TO THE EAST THURSDAY MORNING. HUNG ON TO LOW POPS ACROSS THE COASTAL COUNTIES BEFORE ENDING THURSDAY AFTERNOON AS THIS SYSTEM OPENS AND PUSHES TO THE EAST. FAIR WEATHER ENSUES THURSDAY AFTERNOON INTO FRIDAY AS SHORTWAVE RIDGING BUILDS OVERHEAD. COOL TO MILD TEMPERATURES THURSDAY MORNING WITH SOME RECOVERY THURSDAY WITH HIGHS DROPPING TO SLIGHTLY EARLY APRIL NORMALS. GFS HAS BEEN INDICATING A QUICK RETURN OF GULF MOISTURE FRIDAY NIGHT INTO SATURDAY. A WEAK DISTURBANCE IN THE ZONAL FLOW HAS BEEN SEEN THE LAST FEW RUNS. ALTHOUGH GUIDANCE IS SHOWING VERY LOW POPS ON SATURDAY WILL UP THE CHANCES SLIGHTLY TO MENTION ISOLATED SHOWERS. MODEST DIVERGENCE AND SUFFICIENT MOISTURE...IF OCCURS MIGHT BE ENOUGH FOR A FEW SHOWERS. WIND MACHINE TO POSSIBLY TURN ON SUNDAY AND MONDAY AS NEXT TROUGH AND SURFACE LOW DEVELOP OUT WEST. TEMPERATURES TO CLIMB AS USUAL. MARINE /NOW THROUGH TUESDAY/GENERALLY FAVORABLE MARINE CONDITIONS ARE EXPECTED THROUGH TUESDAY NIGHT WITH MODERATE EASTERLY TO SOUTHEASTERLY WINDS. CONDITIONS MAY APPROACH EXERCISE CAUTION LEVELS ON THE GULF OF MEXICO TONIGHT. SEAS SHOULD REMAIN LOW TO MODERATE. WEDNESDAY THROUGH SUNDAY...COLD FRONT ON TAP FOR A LATE WEDNESDAY OR WEDNESDAY EVENING PASSAGE. LIGHT WINDS IN ADVANCE OF THE FRONT TO SHIFT AND INCREASE FROM THE NORTH. SMALL CRAFT ADVISORIES STILL EXPECTED WITH A 6 TO 12 HOUR WINDOW OF STRONG NORTH FLOW WEDNESDAY NIGHT INTO EARLY THURSDAY AS SURFACE LOW PRESSURE DEVELOPS EAST OF PADRE ISLAND ALONG THE FRONT. WITH THE SURFACE LOW TRACKING EAST FAIRLY QUICKLY THURSDAY NORTH TO NORTHEAST WINDS TO WEAKEN. WINDS VEER FRIDAY TO THE EAST AND SOUTHEAST BY FRIDAY NIGHT BUT THE RETURN FLOW REMAINS LIGHT TO MODERATE. MORE SUBSTANTIAL INCREASE OF SOUTHEAST WINDS RESUME SUNDAY INTO MONDAY AS THE GRADIENT TIGHTENS WITH LOW PRESSURE DEEPENING ACROSS WESTERN TEXAS AND NORTHEAST MEXICO. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 68/60
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1221 PM CDT TUE APR 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 307 AM CDT TUE APR 2 2013 LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED NORTHWEST FLOW ALOFT ACROSS THE UPPER MISSISSIPPI RIVER VALLEY EARLY THIS MORNING. A SHORTWAVE TROUGH WAS NOTED OVER SOUTHERN MANITOBA RACING SOUTHEAST TOWARD THE AREA. SURFACE OBSERVATIONS INDICATED HIGH PRESSURE STRETCHING FROM THE EASTERN DAKOTAS SOUTHEAST INTO THE MIDDLE MISSISSIPPI RIVER VALLEY. THE HIGH WILL SLIDE EAST INTO THE AREA TODAY. MEANWHILE THE SHORTWAVE TROUGH WILL MOVE THROUGH BUT WILL DO LITTLE MORE THAN PRODUCE AN INCREASE IN CLOUD OVER NORTHERN AND CENTRAL WISCONSIN WITH THE REST OF THE FORECAST AREA EXPERIENCING MOSTLY SUNNY SKIES. PLAN ON HIGHS TODAY RANGING FROM THE LOWER 30S OVER NORTHERN WISCONSIN TO THE UPPER 30S TO AROUND 40 ACROSS NORTHEAST IOWA. THE HIGH IS EXPECTED TO SLIDE OVER THE AREA TONIGHT PROVIDING QUIET WEATHER. ANOTHER UNSEASONABLY COLD NIGHT IS IN STORE FOR THE FORECAST AREA WITH LOWS FALLING INTO THE UPPER TEENS TO LOWER 20S. FAVORED COLD SPOTS OVER NORTH CENTRAL WISCONSIN...SUCH AS DIAMOND LAKE...COULD SEE LOWS FALL INTO THE SINGLE DIGITS ABOVE ZERO. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 307 AM CDT TUE APR 2 2013 HIGH PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER ACROSS THE UPPER MISSISSIPPI RIVER VALLEY ON WEDNESDAY WITH MOSTLY SUNNY SKIES EXPECTED. THE SURFACE HIGH WILL SLIDE EAST LATE IN THE DAY AS A WEAK COLD FRONT MOVES EAST OUT OF THE DAKOTAS. SOUTHERLY FLOW WILL INCREASE ACROSS THE AREA AHEAD OF THIS FEATURE HELPING TEMPERATURES WARM SLIGHTLY. PLAN ON HIGH TEMPERATURES RANGING FROM THE LOWER 40S OVER NORTH CENTRAL WISCONSIN TO THE UPPER 40S TO AROUND 50 ACROSS NORTHEAST IOWA. THE FRONT IS EXPECTED TO SAG SOUTHEAST WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING AS A TROUGH PUSHES EASTWARD ACROSS ONTARIO. FORECAST MODELS CONTINUE TO GENERATE SOME LIGHT PRECIPITATION ALONG THE FRONT AS IT MOVES INTO THE FORECAST AREA LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. FORCING IS NOT OVERLY IMPRESSIVE WITH THIS FEATURE WITH ONLY WEAK ISENTROPIC LIFT NOTED. THE UPPER LEVEL FORCING IS PASSING WELL TO THE NORTH OF THE REGION SO NOT EXPECTING MUCH PRECIPITATION. HOWEVER...CANNOT RULE OUT SOME AREAS MEASURING SOME LIGHT RAIN MAINLY ALONG AND NORTH OF INTESTATE 90. SOME SNOW COULD MIX IN EARLY IN THE NORTH BEFORE TEMPERATURES WARM. HIGHS ON THURSDAY ARE EXPECTED TO RANGE FROM LOWER TO MID 40S OVER NORTH CENTRAL WISCONSIN TO THE LOWER 50S ACROSS NORTHEAST IOWA. THE FRONT WILL MOVE SOUTH AND BECOME STATIONARY STRETCHING FROM THE WESTERN SOUTH DAKOTA EAST THROUGH CENTRAL IOWA INTO NORTHERN ILLINOIS. SURFACE HIGH PRESSURE IS EXPECTED TO RETURN BRIEFLY ON FRIDAY PROVIDING ANOTHER QUIET DAY. MEANWHILE...A POTENT SHORTWAVE LOOKS TO MOVE ACROSS THE PACIFIC NORTHWEST AND RACE EAST THROUGH THE DAKOTAS LATE FRIDAY NIGHT. THE STATIONARY FRONT WILL LIFT NORTH AS THE WAVE MOVES EAST AND ACT AS A BAROCLINIC ZONE. SURFACE LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS WESTERN SOUTH DAKOTA LATE FRIDAY NIGHT...THEN MOVES EAST INTO THE UPPER MISSISSIPPI RIVER VALLEY DURING THE DAY ON SATURDAY. STRONG 850 MB WARM AIR ADVECTION DEVELOPS OVER THE AREA AHEAD OF THE APPROACHING LOW FRIDAY NIGHT INTO SATURDAY MORNING. ISENTROPIC LIFT...ON THE 285-305K SURFACES...INCREASES RAPIDLY AS THE LOW MOVES INTO THE AREA. THE FORECAST MODELS HAVE BEEN SHOWING SOME DIFFERENCES REGARDING THE PLACEMENT OF THE BOUNDARY WHICH WILL HAVE A HUGE IMPACT ON PRECIPITATION TYPES. AT THIS TIME IT APPEARS THAT THE MAIN PRECIPITATION TYPE WILL BE RAIN WITH PLENTY OF WARM AIR ADVECTING NORTHWARD INTO THE REGION AHEAD OF THIS SYSTEM. THE PRECIPITATION COULD START OUT AS SNOW EAST OF THE MISSISSIPPI RIVER LATE FRIDAY NIGHT BUT SHOULD QUICKLY TRANSITION OVER TO ALL RAIN EARLY SATURDAY MORNING. THE GEM AND GFS OFFER SIMILAR SOLUTIONS WITH THIS SYSTEM...TAKING THE SURFACE LOW OVER SOUTHERN MINNESOTA ON SATURDAY THEN ACROSS SOUTHERN WISCONSIN SATURDAY NIGHT. THE ECMWF OFFERS A SLOWER AND MORE NORTHERLY SOLUTION...TAKING THE LOW OVER CENTRAL MINNESOTA THROUGH NORTHERN WISCONSIN SATURDAY NIGHT. THE ECMWF SOLUTION WOULD BRING MILD AIR INTO THE REGION ON SATURDAY...WITH HIGHS CLIMBING INTO THE UPPER 50S TO LOWER 60S. ON THE OTHER HAND THE GFS/GEM SOLUTION ARE ON THE COOLER SIDE WITH HIGHS RANGING FROM THE UPPER 30S/LOWER 40S OVER NORTHERN WISCONSIN TO THE MID 50S ACROSS NORTHEAST IOWA. WILL LEAN TOWARDS A MODEL CONSENSUS BLEND APPROACH. PLAN ON HIGHS RANGING FROM THE LOWER 40S OVER NORTH CENTRAL WISCONSIN TO THE MID TO UPPER 50S SOUTH OF INTERSTATE 90. THE LOW IS EXPECTED TO EXIT THE REGION ON SUNDAY. AN ACTIVE PATTERN LOOKS TO DEVELOP MONDAY INTO TUESDAY AS A TROUGH DIGS INTO THE SOUTHWEST CONUS. SOUTHWEST FLOW ALOFT COULD SET UP OVER THE AREA. THE BAROCLINIC ZONE LOOKS TO REMAIN OVER THE UPPER MIDWEST AS SHORTWAVE ENERGY EJECTS OUT OF OF THE SOUTHWEST FLOW AND INTERACTS WITH IT. LATEST GUIDANCE SUGGESTS THE BOUNDARY WILL STRETCH FROM NORTHERN OHIO WESTWARD THROUGH NORTHERN ILLINOIS THROUGH SOUTHERN IOWA. WILL HAVE TO KEEP A CLOSE WATCH ON FUTURE MODEL RUNS WITH THE POTENTIAL FOR THIS ACTIVE PATTERN TO BRING SEVERAL ROUNDS OF PRECIPITATION TO THE REGION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1221 PM CDT TUE APR 2 2013 QUIET STRETCH OF VFR WEATHER TO CONTINUE. HIGH PRESSURE CURRENTLY EXTENDING FROM MANITOBA INTO MISSOURI AND ILLINOIS WILL MOVE SOUTHEAST THROUGH THE PERIOD AND BE CENTERED NEAR THE SOUTHERN TIP OF LAKE MICHIGAN BY LATE WEDNESDAY MORNING. THE NORTHWEST WINDS WILL DROP OFF AROUND SUNSET TO 5 KNOTS OR LESS AND THEN COME AROUND THE SOUTH AFTER SUNRISE WEDNESDAY ONCE THE RIDGE AXIS GOES BY. OTHER THAN A FEW MID LEVEL CLOUDS THIS AFTERNOON...LITTLE OR NO CLOUDS EXPECTED THROUGH THE PERIOD. && .HYDROLOGY... ISSUED AT 307 AM CDT TUE APR 2 2013 THE COMBINATION OF SNOW MELT AND THE RAIN OVER THE WEEKEND HAS RESULTED IN FLOODING ALONG THE TREMPEALEAU RIVER AT DODGE. THE LATEST STAGE WAS 9.21FT. FLOOD STAGE IS 9FT. THE RIVER IS EXPECTED TO CREST THIS MORNING AND THEN SLOWLY FALL LATE THIS AFTERNOON INTO THIS EVENING. THE BLACK RIVER HAS CRESTED BELOW FLOOD STAGE AT BLACK RIVER FALLS. WITH PLENTY OF SNOW UPSTREAM...THIS RIVER WILL LIKELY STAY HIGH FOR THE NEXT SEVERAL DAYS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...WETENKAMP LONG TERM...WETENKAMP AVIATION...04 HYDROLOGY...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
610 AM CDT TUE APR 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 307 AM CDT TUE APR 2 2013 LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED NORTHWEST FLOW ALOFT ACROSS THE UPPER MISSISSIPPI RIVER VALLEY EARLY THIS MORNING. A SHORTWAVE TROUGH WAS NOTED OVER SOUTHERN MANITOBA RACING SOUTHEAST TOWARD THE AREA. SURFACE OBSERVATIONS INDICATED HIGH PRESSURE STRETCHING FROM THE EASTERN DAKOTAS SOUTHEAST INTO THE MIDDLE MISSISSIPPI RIVER VALLEY. THE HIGH WILL SLIDE EAST INTO THE AREA TODAY. MEANWHILE THE SHORTWAVE TROUGH WILL MOVE THROUGH BUT WILL DO LITTLE MORE THAN PRODUCE AN INCREASE IN CLOUD OVER NORTHERN AND CENTRAL WISCONSIN WITH THE REST OF THE FORECAST AREA EXPERIENCING MOSTLY SUNNY SKIES. PLAN ON HIGHS TODAY RANGING FROM THE LOWER 30S OVER NORTHERN WISCONSIN TO THE UPPER 30S TO AROUND 40 ACROSS NORTHEAST IOWA. THE HIGH IS EXPECTED TO SLIDE OVER THE AREA TONIGHT PROVIDING QUIET WEATHER. ANOTHER UNSEASONABLY COLD NIGHT IS IN STORE FOR THE FORECAST AREA WITH LOWS FALLING INTO THE UPPER TEENS TO LOWER 20S. FAVORED COLD SPOTS OVER NORTH CENTRAL WISCONSIN...SUCH AS DIAMOND LAKE...COULD SEE LOWS FALL INTO THE SINGLE DIGITS ABOVE ZERO. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 307 AM CDT TUE APR 2 2013 HIGH PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER ACROSS THE UPPER MISSISSIPPI RIVER VALLEY ON WEDNESDAY WITH MOSTLY SUNNY SKIES EXPECTED. THE SURFACE HIGH WILL SLIDE EAST LATE IN THE DAY AS A WEAK COLD FRONT MOVES EAST OUT OF THE DAKOTAS. SOUTHERLY FLOW WILL INCREASE ACROSS THE AREA AHEAD OF THIS FEATURE HELPING TEMPERATURES WARM SLIGHTLY. PLAN ON HIGH TEMPERATURES RANGING FROM THE LOWER 40S OVER NORTH CENTRAL WISCONSIN TO THE UPPER 40S TO AROUND 50 ACROSS NORTHEAST IOWA. THE FRONT IS EXPECTED TO SAG SOUTHEAST WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING AS A TROUGH PUSHES EASTWARD ACROSS ONTARIO. FORECAST MODELS CONTINUE TO GENERATE SOME LIGHT PRECIPITATION ALONG THE FRONT AS IT MOVES INTO THE FORECAST AREA LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. FORCING IS NOT OVERLY IMPRESSIVE WITH THIS FEATURE WITH ONLY WEAK ISENTROPIC LIFT NOTED. THE UPPER LEVEL FORCING IS PASSING WELL TO THE NORTH OF THE REGION SO NOT EXPECTING MUCH PRECIPITATION. HOWEVER...CANNOT RULE OUT SOME AREAS MEASURING SOME LIGHT RAIN MAINLY ALONG AND NORTH OF INTESTATE 90. SOME SNOW COULD MIX IN EARLY IN THE NORTH BEFORE TEMPERATURES WARM. HIGHS ON THURSDAY ARE EXPECTED TO RANGE FROM LOWER TO MID 40S OVER NORTH CENTRAL WISCONSIN TO THE LOWER 50S ACROSS NORTHEAST IOWA. THE FRONT WILL MOVE SOUTH AND BECOME STATIONARY STRETCHING FROM THE WESTERN SOUTH DAKOTA EAST THROUGH CENTRAL IOWA INTO NORTHERN ILLINOIS. SURFACE HIGH PRESSURE IS EXPECTED TO RETURN BRIEFLY ON FRIDAY PROVIDING ANOTHER QUIET DAY. MEANWHILE...A POTENT SHORTWAVE LOOKS TO MOVE ACROSS THE PACIFIC NORTHWEST AND RACE EAST THROUGH THE DAKOTAS LATE FRIDAY NIGHT. THE STATIONARY FRONT WILL LIFT NORTH AS THE WAVE MOVES EAST AND ACT AS A BAROCLINIC ZONE. SURFACE LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS WESTERN SOUTH DAKOTA LATE FRIDAY NIGHT...THEN MOVES EAST INTO THE UPPER MISSISSIPPI RIVER VALLEY DURING THE DAY ON SATURDAY. STRONG 850 MB WARM AIR ADVECTION DEVELOPS OVER THE AREA AHEAD OF THE APPROACHING LOW FRIDAY NIGHT INTO SATURDAY MORNING. ISENTROPIC LIFT...ON THE 285-305K SURFACES...INCREASES RAPIDLY AS THE LOW MOVES INTO THE AREA. THE FORECAST MODELS HAVE BEEN SHOWING SOME DIFFERENCES REGARDING THE PLACEMENT OF THE BOUNDARY WHICH WILL HAVE A HUGE IMPACT ON PRECIPITATION TYPES. AT THIS TIME IT APPEARS THAT THE MAIN PRECIPITATION TYPE WILL BE RAIN WITH PLENTY OF WARM AIR ADVECTING NORTHWARD INTO THE REGION AHEAD OF THIS SYSTEM. THE PRECIPITATION COULD START OUT AS SNOW EAST OF THE MISSISSIPPI RIVER LATE FRIDAY NIGHT BUT SHOULD QUICKLY TRANSITION OVER TO ALL RAIN EARLY SATURDAY MORNING. THE GEM AND GFS OFFER SIMILAR SOLUTIONS WITH THIS SYSTEM...TAKING THE SURFACE LOW OVER SOUTHERN MINNESOTA ON SATURDAY THEN ACROSS SOUTHERN WISCONSIN SATURDAY NIGHT. THE ECMWF OFFERS A SLOWER AND MORE NORTHERLY SOLUTION...TAKING THE LOW OVER CENTRAL MINNESOTA THROUGH NORTHERN WISCONSIN SATURDAY NIGHT. THE ECMWF SOLUTION WOULD BRING MILD AIR INTO THE REGION ON SATURDAY...WITH HIGHS CLIMBING INTO THE UPPER 50S TO LOWER 60S. ON THE OTHER HAND THE GFS/GEM SOLUTION ARE ON THE COOLER SIDE WITH HIGHS RANGING FROM THE UPPER 30S/LOWER 40S OVER NORTHERN WISCONSIN TO THE MID 50S ACROSS NORTHEAST IOWA. WILL LEAN TOWARDS A MODEL CONSENSUS BLEND APPROACH. PLAN ON HIGHS RANGING FROM THE LOWER 40S OVER NORTH CENTRAL WISCONSIN TO THE MID TO UPPER 50S SOUTH OF INTERSTATE 90. THE LOW IS EXPECTED TO EXIT THE REGION ON SUNDAY. AN ACTIVE PATTERN LOOKS TO DEVELOP MONDAY INTO TUESDAY AS A TROUGH DIGS INTO THE SOUTHWEST CONUS. SOUTHWEST FLOW ALOFT COULD SET UP OVER THE AREA. THE BAROCLINIC ZONE LOOKS TO REMAIN OVER THE UPPER MIDWEST AS SHORTWAVE ENERGY EJECTS OUT OF OF THE SOUTHWEST FLOW AND INTERACTS WITH IT. LATEST GUIDANCE SUGGESTS THE BOUNDARY WILL STRETCH FROM NORTHERN OHIO WESTWARD THROUGH NORTHERN ILLINOIS THROUGH SOUTHERN IOWA. WILL HAVE TO KEEP A CLOSE WATCH ON FUTURE MODEL RUNS WITH THE POTENTIAL FOR THIS ACTIVE PATTERN TO BRING SEVERAL ROUNDS OF PRECIPITATION TO THE REGION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 610 AM CDT TUE APR 2 2013 SKIES SHOULD REMAIN CLEAR FOR MOST OF THE NEXT 24 HOURS WITH A BRIEF PERIOD OF SCATTERED MID TO UPPER LEVEL CLOUDS MOVING THROUGH IN THE LATE MORNING/EARLY AFTERNOON. OTHERWISE...NORTHWEST WINDS WILL PEAK AROUND 10KTS LATER THIS MORNING/EARLY AFTERNOON BEFORE GOING LIGHT AND VARIABLE TONIGHT AS A RIDGE OF HIGH PRESSURE MOVES IN ACROSS THE AREA. && .HYDROLOGY... ISSUED AT 307 AM CDT TUE APR 2 2013 THE COMBINATION OF SNOW MELT AND THE RAIN OVER THE WEEKEND HAS RESULTED IN FLOODING ALONG THE TREMPEALEAU RIVER AT DODGE. THE LATEST STAGE WAS 9.21FT. FLOOD STAGE IS 9FT. THE RIVER IS EXPECTED TO CREST THIS MORNING AND THEN SLOWLY FALL LATE THIS AFTERNOON INTO THIS EVENING. THE BLACK RIVER HAS CRESTED BELOW FLOOD STAGE AT BLACK RIVER FALLS. WITH PLENTY OF SNOW UPSTREAM...THIS RIVER WILL LIKELY STAY HIGH FOR THE NEXT SEVERAL DAYS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...WETENKAMP LONG TERM...WETENKAMP AVIATION...HALBACH HYDROLOGY...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
307 AM CDT TUE APR 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 307 AM CDT TUE APR 2 2013 LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED NORTHWEST FLOW ALOFT ACROSS THE UPPER MISSISSIPPI RIVER VALLEY EARLY THIS MORNING. A SHORTWAVE TROUGH WAS NOTED OVER SOUTHERN MANITOBA RACING SOUTHEAST TOWARD THE AREA. SURFACE OBSERVATIONS INDICATED HIGH PRESSURE STRETCHING FROM THE EASTERN DAKOTAS SOUTHEAST INTO THE MIDDLE MISSISSIPPI RIVER VALLEY. THE HIGH WILL SLIDE EAST INTO THE AREA TODAY. MEANWHILE THE SHORTWAVE TROUGH WILL MOVE THROUGH BUT WILL DO LITTLE MORE THAN PRODUCE AN INCREASE IN CLOUD OVER NORTHERN AND CENTRAL WISCONSIN WITH THE REST OF THE FORECAST AREA EXPERIENCING MOSTLY SUNNY SKIES. PLAN ON HIGHS TODAY RANGING FROM THE LOWER 30S OVER NORTHERN WISCONSIN TO THE UPPER 30S TO AROUND 40 ACROSS NORTHEAST IOWA. THE HIGH IS EXPECTED TO SLIDE OVER THE AREA TONIGHT PROVIDING QUIET WEATHER. ANOTHER UNSEASONABLY COLD NIGHT IS IN STORE FOR THE FORECAST AREA WITH LOWS FALLING INTO THE UPPER TEENS TO LOWER 20S. FAVORED COLD SPOTS OVER NORTH CENTRAL WISCONSIN...SUCH AS DIAMOND LAKE...COULD SEE LOWS FALL INTO THE SINGLE DIGITS ABOVE ZERO. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 307 AM CDT TUE APR 2 2013 HIGH PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER ACROSS THE UPPER MISSISSIPPI RIVER VALLEY ON WEDNESDAY WITH MOSTLY SUNNY SKIES EXPECTED. THE SURFACE HIGH WILL SLIDE EAST LATE IN THE DAY AS A WEAK COLD FRONT MOVES EAST OUT OF THE DAKOTAS. SOUTHERLY FLOW WILL INCREASE ACROSS THE AREA AHEAD OF THIS FEATURE HELPING TEMPERATURES WARM SLIGHTLY. PLAN ON HIGH TEMPERATURES RANGING FROM THE LOWER 40S OVER NORTHCENTRAL WISCONSIN TO THE UPPER 40S TO AROUND 50 ACROSS NORTHEAST IOWA. THE FRONT IS EXPECTED TO SAG SOUTHEAST WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING AS A TROUGH PUSHES EASTWARD ACROSS ONTARIO. FORECAST MODELS CONTINUE TO GENERATE SOME LIGHT PRECIPITATION ALONG THE FRONT AS IT MOVES INTO THE FORECAST AREA LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. FORCING IS NOT OVERLY IMPRESSIVE WITH THIS FEATURE WITH ONLY WEAK ISENTROPIC LIFT NOTED. THE UPPER LEVEL FORCING IS PASSING WELL TO THE NORTH OF THE REGION SO NOT EXPECTING MUCH PRECIPITATION. HOWEVER...CANNOT RULE OUT SOME AREAS MEASURING SOME LIGHT RAIN MAINLY ALONG AND NORTH OF INTESTATE 90. SOME SNOW COULD MIX IN EARLY IN THE NORTH BEFORE TEMPERATURES WARM. HIGHS ON THURSDAY ARE EXPECTED TO RANGE FROM LOWER TO MID 40S OVER NORTHCENTRAL WISCONSIN TO THE LOWER 50S ACROSS NORTHEAST IOWA. THE FRONT WILL MOVE SOUTH AND BECOME STATIONARY STRETCHING FROM THE WESTERN SOUTH DAKOTA EAST THROUGH CENTRAL IOWA INTO NORTHERN ILLINOIS. SURFACE HIGH PRESSURE IS EXPECTED TO RETURN BRIEFLY ON FRIDAY PROVIDING ANOTHER QUIET DAY. MEANWHILE...A POTENT SHORTWAVE LOOKS TO MOVE ACROSS THE PACIFIC NORTHWEST AND RACE EAST THROUGH THE DAKOTAS LATE FRIDAY NIGHT. THE STATIONARY FRONT WILL LIFT NORTH AS THE WAVE MOVES EAST AND ACT AS A BAROCLINIC ZONE. SURFACE LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS WESTERN SOUTH DAKOTA LATE FRIDAY NIGHT...THEN MOVES EAST INTO THE UPPER MISSISSIPPI RIVER VALLEY DURING THE DAY ON SATURDAY. STRONG 850 MB WARM AIR ADVECTION DEVELOPS OVER THE AREA AHEAD OF THE APPROACHING LOW FRIDAY NIGHT INTO SATURDAY MORNING. ISENTROPIC LIFT...ON THE 285-305K SURFACES...INCREASES RAPIDLY AS THE LOW MOVES INTO THE AREA. THE FORECAST MODELS HAVE BEEN SHOWING SOME DIFFERENCES REGARDING THE PLACEMENT OF THE BOUNDARY WHICH WILL HAVE A HUGE IMPACT ON PRECIPITATION TYPES. AT THIS TIME IT APPEARS THAT THE MAIN PRECIPITATION TYPE WILL BE RAIN WITH PLENTY OF WARM AIR ADVECTING NORTHWARD INTO THE REGION AHEAD OF THIS SYSTEM. THE PRECIPITATION COULD START OUT AS SNOW EAST OF THE MISSISSIPPI RIVER LATE FRIDAY NIGHT BUT SHOULD QUICKLY TRANSITION OVER TO ALL RAIN EARLY SATURDAY MORNING. THE GEM AND GFS OFFER SIMILAR SOLUTIONS WITH THIS SYSTEM...TAKING THE SURFACE LOW OVER SOUTHERN MINNESOTA ON SATURDAY THEN ACROSS SOUTHERN WISCONSIN SATURDAY NIGHT. THE ECMWF OFFERS A SLOWER AND MORE NORTHERLY SOLUTION...TAKING THE LOW OVER CENTRAL MINNESOTA THROUGH NORTHERN WISCONSIN SATURDAY NIGHT. THE ECMWF SOLUTION WOULD BRING MILD AIR INTO THE REGION ON SATURDAY...WITH HIGHS CLIMBING INTO THE UPPER 50S TO LOWER 60S. ON THE OTHER HAND THE GFS/GEM SOLUTION ARE ON THE COOLER SIDE WITH HIGHS RANGING FROM THE UPPER 30S/LOWER 40S OVER NORTHERN WISCONSIN TO THE MID 50S ACROSS NORTHEAST IOWA. WILL LEAN TOWARDS A MODEL CONSENSUS BLEND APPROACH. PLAN ON HIGHS RANGING FROM THE LOWER 40S OVER NORTH CENTRAL WISCONSIN TO THE MID TO UPPER 50S SOUTH OF INTERSTATE 90. THE LOW IS EXPECTED TO EXIT THE REGION ON SUNDAY. AN ACTIVE PATTERN LOOKS TO DEVELOP MONDAY INTO TUESDAY AS A TROUGH DIGS INTO THE SOUTHWEST CONUS. SOUTHWEST FLOW ALOFT COULD SET UP OVER THE AREA. THE BAROCLINIC ZONE LOOKS TO REMAIN OVER THE UPPER MIDWEST AS SHORTWAVE ENERGY EJECTS OUT OF OF THE SOUTHWEST FLOW AND INTERACTS WITH IT. LATEST GUIDANCE SUGGESTS THE BOUNDARY WILL STRETCH FROM NORTHERN OHIO WESTWARD THROUGH NORTHERN ILLINOIS THROUGH SOUTHERN IOWA. WILL HAVE TO KEEP A CLOSE WATCH ON FUTURE MODEL RUNS WITH THE POTENTIAL FOR THIS ACTIVE PATTERN TO BRING SEVERAL ROUNDS OF PRECIPITATION TO THE REGION. && .AVIATION...TONIGHT AND TUESDAY 631 PM CDT MON APR 1 2013 VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD WITH SURFACE HIGH BEING THE DOMINATE WEATHER FEATURE. A WEAK SHORTWAVE TROUGH WILL DROP ACROSS THE AREA TUESDAY WHICH WILL ONLY PRODUCE SOME SCATTERED MID LEVEL CLOUDS. NORTHWEST WINDS WILL CONTINUE AT 5 TO 10 KNOTS TONIGHT AND AROUND 12 KNOTS TUESDAY AFTERNOON. && .HYDROLOGY... ISSUED AT 307 AM CDT TUE APR 2 2013 THE COMBINATION OF SNOW MELT AND THE RAIN OVER THE WEEKEND HAS RESULTED IN FLOODING ALONG THE TREMPEALEAU RIVER AT DODGE. THE LATEST STAGE WAS 9.21FT. FLOOD STAGE IS 9FT. THE RIVER IS EXPECTED TO CREST THIS MORNING AND THEN SLOWLY FALL LATE THIS AFTERNOON INTO THIS EVENING. THE BLACK RIVER HAS CRESTED BELOW FLOOD STAGE AT BLACK RIVER FALLS. WITH PLENTY OF SNOW UPSTREAM...THIS RIVER WILL LIKELY STAY HIGH FOR THE NEXT SEVERAL DAYS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...WETENKAMP LONG TERM...WETENKAMP AVIATION...RABERDING HYDROLOGY...WETENKAMP
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
610 AM MDT TUE APR 2 2013 .SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT) ISSUED AT 345 AM MDT TUE APR 2 2013 AREA OF LOW PRESSURE DETACHED FROM THE MEAN FLOW WILL SLOWLY MOVE OUT OF UTAH THIS MORNING AND INTO THE SOUTHERN PLAINS BY WEDNESDAY NIGHT. THE FEW WEAK SHOWERS THAT HAVE PUSHED NORTHEAST ACROSS THE CO/WY STATELINE HAVE DISSIPATED QUICKLY LOSING BEST QG VERTICAL VELOCITIES WHICH ARE WELL SOUTH OF THE CWFA. ALTHOUGH STILL CANT RULE OUT ISOLATED TO LOCALLY SCATTERED SHOWERS/DRIZZLE THROUGH THE AFTERNOON...THESE WILL NEED TO RELY MAINLY ON LFQ H3 JET HELP AND INSTABILITY. AS A RESULT...HAVE DECREASED PRECIPITATION CHANCES SOME ESPECIALLY THIS MORNING...KEEPING THE HIGHEST IN AREAS NR THE CO/WY STATELINE AND ALONG THE I80 CORRIDOR. ADDITIONALLY...PROGD LIFTED INDICES WILL FALL SLIGHTLY NEGATIVE FOR AREAS WEST OF THE LARAMIE RANGE THIS AFTERNOON. SO KEPT THE MENTION OF THUNDER FOR THESE AREAS. ALTHOUGH WOULD EXPECT THE BEST THUNDER POTENTIAL TO BE OVER THE SNOWY/SIERRA MADRE RANGES. THE OTHER CONCERN THIS MORNING IS PATCHY FOG THAT HAS DEVELOPED ALONG THE INTERSTATE 80 SUMMIT. THE AFFECTED AREA HAS THUS FAR BEEN CONFINED TO A FEW MILE STRETCH OF I80. LATEST HRRR EVEN SHOWS SOME OF THIS STRATUS DESCENDING ALONG THE EASTERN FOOTHILLS OF THE SOUTHERN LARAMIE RANGE TOWARDS DAYBREAK AS WELL. FOR NOW...HAVE ADDED FOG MENTION TO THIS AREA THROUGH MID-MORNING. H7 TEMPERATURES HOVERING AROUND -3C COMBINED WITH THICKER CLOUD-COVER WILL TEMPER AFTERNOON HIGH TEMPERATURES SOMEWHAT...WITH MAINLY 50S EXPECTED. THE EXCEPTION WILL BE AREAS IN AND AROUND THE SOUTHEAST WYOMING MOUNTAINS WHERE HIGHS WILL ONLY REACH THE 40S. LATEST MODEL GUIDANCE HINTS AT THE POSSIBILITY OF PATCHY FOG FROM CHEYENNE TO SIDNEY AGAIN LATER TONIGHT AND EARLY WEDNESDAY. SO HAVE ADDED PATCHY MENTION. EXPECT MAINLY DRY CONDITIONS TONIGHT AS BEST MOISTURE/LIFT ASSOCIATED WITH THE UPPER LOW EXITS TO THE SOUTHEAST OF THE AREA. HEIGHTS WILL RISE BEHIND THE DEPARTING LOW PRESSURE SYSTEM ON WEDNESDAY. EXPECT A MOSTLY DRY DAY AS THIS WEAK TRANSITORY RIDGE TRANSITIONS TO NORTHWEST FLOW. H7 TEMPERATURES WILL CLIMB TO FREEZING AND WITH LESS CLOUD-COVER WILL SEE HIGHS CLIMB WELL INTO THE 50S AND 60S AT ALL LOWER ELEVATIONS. MAY EVEN FLIRT WITH 70 NORTH OF THE PINE RIDGE. MODELS POINT TO ANOTHER WEAK FRONT WILL PUSH SOUTH THROUGH THE AREA WEDNESDAY NIGHT. MOISTURE LOOKS TO BE LIMITING FACTOR...SO KEPT WEDNESDAY NIGHT DRY FOR NOW. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 345 AM MDT TUE APR 2 2013 UPPER RIDGE WILL SHIFT EAST ACROSS THE CWA THURSDAY AND THURSDAY NIGHT RESULTING IN MILD AND DRY WEATHER THROUGH MOST OF FRIDAY. NEXT UPPER TROUGH TO AFFECT THE REGION WILL APPROACH ON FRIDAY AND MAY SPREAD SOME SHOWERS INTO FAR WESTERN AND NORTHERN PARTS OF THE CWA LATE IN THE DAY. THIS SYSTEM WILL PASS ACROSS FRIDAY NIGHT BRINGING A MODEST PACIFIC FRONT AND A LITTLE COOLER TEMPERATURES FOR SATURDAY. YET ANOTHER SHORTWAVE SHOULD PASS BY SATURDAY NIGHT BEFORE A MORE SIGNIFICANT TROUGH DIGS OVER THE WESTERN CONUS SUNDAY NIGHT AND MONDAY SPREADING MORE WIDESPREAD RAIN AND SNOW SHOWERS ACROSS THE CWA AT THAT TIME. TEMPERATURES WILL ALSO COOL SUNDAY THROUGH MONDAY DUE TO MORE CLOUD COVER AND LOWERING HEIGHTS. MODELS SHOW THIS SYSTEM COULD BE A DECENT PRECIPITATION PRODUCER FOR THE CWA EARLY NEXT WEEK BUT WILL SEE HOW FUTURE RUNS TURN OUT BEFORE GETTING TOO EXCITED. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 610 AM MDT TUE APR 2 2013 SLOW MOVING AREA OF LOW PRESSURE WILL MOVE FROM UTAH INTO COLORADO TODAY. A FEW SHOWERS ALONG WITH MVFR/IFR CIGS WILL DEVELOP AND LIFT NORTHEAST AFFECTING MAINLY SOUTHEAST WYOMING TERMINALS TODAY. HAVE INCLUDED A TEMPO GROUP THROUGH 14Z/15Z AT KLAR AND KCYS AS A BAND OF WEAK SHOWERS HAVE DEVELOPED TO THEIR NORTH. OTHERWISE...EXPECT VFR CONDITIONS TO PREVAIL AT AREA AIRPORTS. FOG POTENTIAL WILL RETURN AFTER 06Z TONIGHT FROM KCYS TO KSNY...SO HAVE INCLUDED A VCFG MENTION FOR NOW. && .FIRE WEATHER... ISSUED AT 345 AM MDT TUE APR 2 2013 MINIMAL FIRE WEATHER CONCERNS EXPECTED THIS WEEK. AN AREA OF LOW PRESSURE WILL MOVING FROM UTAH INTO COLORADO TODAY. CLOUDS AND LIGHT PRECIPITATION CHANCES WILL HOLD HIGH TEMPERATURES DOWN AND MINIMUM RELATIVE HUMIDITIES UP TODAY. THERE WILL BE UP TO A FEW INCHES OF NEW SNOW OVER THE SNOWY AND SIERRA MADRES THROUGH TODAY. PRECIPITATION WILL DECREASE TONIGHT...WITH DRIER CONDITIONS SETTLING IN FOR WEDNESDAY THROUGH FRIDAY. WARMER TEMPERATURES ARE EXPECTED AS WELL...WITH 70S RETURNING TO EASTERN PORTIONS OF THE DISTRICT BY WEEKS END. MINIMUM RELATIVE HUMIDITIES WILL HOVER IN THE 20 TO 30 PERCENT RANGE EACH DAY. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...HAHN LONG TERM...RE AVIATION...HAHN FIRE WEATHER...HAHN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
345 AM MDT TUE APR 2 2013 .SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT) ISSUED AT 345 AM MDT TUE APR 2 2013 AREA OF LOW PRESSURE DETACHED FROM THE MEAN FLOW WILL SLOWLY MOVE OUT OF UTAH THIS MORNING AND INTO THE SOUTHERN PLAINS BY WEDNESDAY NIGHT. THE FEW WEAK SHOWERS THAT HAVE PUSHED NORTHEAST ACROSS THE CO/WY STATELINE HAVE DISSIPATED QUICKLY LOSING BEST QG VERTICAL VELOCITIES WHICH ARE WELL SOUTH OF THE CWFA. ALTHOUGH STILL CANT RULE OUT ISOLATED TO LOCALLY SCATTERED SHOWERS/DRIZZLE THROUGH THE AFTERNOON...THESE WILL NEED TO RELY MAINLY ON LFQ H3 JET HELP AND INSTABILITY. AS A RESULT...HAVE DECREASED PRECIPITATION CHANCES SOME ESPECIALLY THIS MORNING...KEEPING THE HIGHEST IN AREAS NR THE CO/WY STATELINE AND ALONG THE I80 CORRIDOR. ADDITIONALLY...PROGD LIFTED INDICES WILL FALL SLIGHTLY NEGATIVE FOR AREAS WEST OF THE LARAMIE RANGE THIS AFTERNOON. SO KEPT THE MENTION OF THUNDER FOR THESE AREAS. ALTHOUGH WOULD EXPECT THE BEST THUNDER POTENTIAL TO BE OVER THE SNOWY/SIERRA MADRE RANGES. THE OTHER CONCERN THIS MORNING IS PATCHY FOG THAT HAS DEVELOPED ALONG THE INTERSTATE 80 SUMMIT. THE AFFECTED AREA HAS THUS FAR BEEN CONFINED TO A FEW MILE STRETCH OF I80. LATEST HRRR EVEN SHOWS SOME OF THIS STRATUS DESCENDING ALONG THE EASTERN FOOTHILLS OF THE SOUTHERN LARAMIE RANGE TOWARDS DAYBREAK AS WELL. FOR NOW...HAVE ADDED FOG MENTION TO THIS AREA THROUGH MID-MORNING. H7 TEMPERATURES HOVERING AROUND -3C COMBINED WITH THICKER CLOUD-COVER WILL TEMPER AFTERNOON HIGH TEMPERATURES SOMEWHAT...WITH MAINLY 50S EXPECTED. THE EXCEPTION WILL BE AREAS IN AND AROUND THE SOUTHEAST WYOMING MOUNTAINS WHERE HIGHS WILL ONLY REACH THE 40S. LATEST MODEL GUIDANCE HINTS AT THE POSSIBILITY OF PATCHY FOG FROM CHEYENNE TO SIDNEY AGAIN LATER TONIGHT AND EARLY WEDNESDAY. SO HAVE ADDED PATCHY MENTION. EXPECT MAINLY DRY CONDITIONS TONIGHT AS BEST MOISTURE/LIFT ASSOCIATED WITH THE UPPER LOW EXITS TO THE SOUTHEAST OF THE AREA. HEIGHTS WILL RISE BEHIND THE DEPARTING LOW PRESSURE SYSTEM ON WEDNESDAY. EXPECT A MOSTLY DRY DAY AS THIS WEAK TRANSITORY RIDGE TRANSITIONS TO NORTHWEST FLOW. H7 TEMPERATURES WILL CLIMB TO FREEZING AND WITH LESS CLOUD-COVER WILL SEE HIGHS CLIMB WELL INTO THE 50S AND 60S AT ALL LOWER ELEVATIONS. MAY EVEN FLIRT WITH 70 NORTH OF THE PINE RIDGE. MODELS POINT TO ANOTHER WEAK FRONT WILL PUSH SOUTH THROUGH THE AREA WEDNESDAY NIGHT. MOISTURE LOOKS TO BE LIMITING FACTOR...SO KEPT WEDNESDAY NIGHT DRY FOR NOW. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 345 AM MDT TUE APR 2 2013 UPPER RIDGE WILL SHIFT EAST ACROSS THE CWA THURSDAY AND THURSDAY NIGHT RESULTING IN MILD AND DRY WEATHER THROUGH MOST OF FRIDAY. NEXT UPPER TROUGH TO AFFECT THE REGION WILL APPROACH ON FRIDAY AND MAY SPREAD SOME SHOWERS INTO FAR WESTERN AND NORTHERN PARTS OF THE CWA LATE IN THE DAY. THIS SYSTEM WILL PASS ACROSS FRIDAY NIGHT BRINGING A MODEST PACIFIC FRONT AND A LITTLE COOLER TEMPERATURES FOR SATURDAY. YET ANOTHER SHORTWAVE SHOULD PASS BY SATURDAY NIGHT BEFORE A MORE SIGNIFICANT TROUGH DIGS OVER THE WESTERN CONUS SUNDAY NIGHT AND MONDAY SPREADING MORE WIDESPREAD RAIN AND SNOW SHOWERS ACROSS THE CWA AT THAT TIME. TEMPERATURES WILL ALSO COOL SUNDAY THROUGH MONDAY DUE TO MORE CLOUD COVER AND LOWERING HEIGHTS. MODELS SHOW THIS SYSTEM COULD BE A DECENT PRECIPITATION PRODUCER FOR THE CWA EARLY NEXT WEEK BUT WILL SEE HOW FUTURE RUNS TURN OUT BEFORE GETTING TOO EXCITED. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1209 AM MDT TUE APR 2 2013 AN AREA OF LOW PRESSURE SPINNING THROUGH UTAH EARLY THIS MORNING WILL VERY SLOWLY PUSH INTO COLORADO BY LATE TODAY. AS A RESULT...ITS IMPACT WILL BE CONFINED TO SE WYOMING TERMINALS IN THE WAY OF MVFR/IFR CIGS/VSBYS THROUGH AROUND 18Z TUESDAY. WILL SEE PERIODIC BANDS OF WEAK SHOWERS LIFTING NORTHEAST AND HAVE INCLUDED MENTION PRIMARILY AT KCYS DURING THE MORNING HOURS. CONFIDENCE IS LESS AT KRWL AND KLAR...THUS HAVE LEFT VCSH IN UNTIL TIMING CAN BE NARROWED. CONDITIONS WILL IMPROVE ACROSS SE WYOMING BY THIS AFTERNOON. OTHERWISE...EXPECT VFR CONDITIONS AT WESTERN NEBRASKA PANHANDLE AIRFIELDS THROUGH THE FORECAST PERIOD. && .FIRE WEATHER... ISSUED AT 345 AM MDT TUE APR 2 2013 MINIMAL FIRE WEATHER CONCERNS EXPECTED THIS WEEK. AN AREA OF LOW PRESSURE WILL MOVING FROM UTAH INTO COLORADO TODAY. CLOUDS AND LIGHT PRECIPITATION CHANCES WILL HOLD HIGH TEMPERATURES DOWN AND MINIMUM RELATIVE HUMIDITIES UP TODAY. THERE WILL BE UP TO A FEW INCHES OF NEW SNOW OVER THE SNOWY AND SIERRA MADRES THROUGH TODAY. PRECIPITATION WILL DECREASE TONIGHT...WITH DRIER CONDITIONS SETTLING IN FOR WEDNESDAY THROUGH FRIDAY. WARMER TEMPERATURES ARE EXPECTED AS WELL...WITH 70S RETURNING TO EASTERN PORTIONS OF THE DISTRICT BY WEEKS END. MINIMUM RELATIVE HUMIDITIES WILL HOVER IN THE 20 TO 30 PERCENT RANGE EACH DAY. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...HAHN LONG TERM...RE AVIATION...HAHN FIRE WEATHER...HAHN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1058 PM MDT WED APR 3 2013 .UPDATE... ISSUED AT 905 PM MDT WED APR 3 2013 CURRENT WATER VAPOR IMAGERY INDICATING AN EMBEDDED SHORT WAVE TRANSLATING ACROSS SOUTH CENTRAL WYOMING AND INTO NORTH CENTRAL COLORADO AT THIS TIME. REGIONAL RADARS INDICATING SHOWERS ALONG WITH A FEW LIGHTNING STRIKES ASSOCIATED WITH THIS SYSTEM MOVING ACROSS NORTHERN COLORADO AT THIS TIME. LATEST NAM AND RAP HAVE SHOWERS DIMINISHING AS THEY CONTINUE TO MOVE SOUTH AND EAST WITH ONLY INCREASING MID AND AND HIGH LEVEL CLOUDS ACROSS SOUTH CENTRAL AND SOUTHEAST COLORADO. HOWEVER...THE LAST FEW RUNS OF THE HRRR IS INDICATING A FEW SHOWERS MOVING OUT ACROSS THE FRONT RANGE AND INTO NORTHERN AND EASTERN PORTIONS OF EL PASO COUNTY AFTER MIDNIGHT. HAVE NOT BOUGHT OFF ON THIS SCENARIO WITH SHOWERS SEEMINGLY DIMINISHING WITH THE LOSS OF HEATING...THOUGH WILL NEED TO MONITOR LATEST HRRR TRENDS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 313 PM MDT WED APR 3 2013 CURRENTLY... SKIES CLEARING PRETTY QUICKLY FROM NW TO SE ACROSS THE REGION. ONLY AREA OF CONSIDERABLE CLOUDINESS AT 2 PM WAS OVER THE FAR SE PLAINS. Q WAS BUBBLING OVER THE S MTNS. TEMPS WERE IN THE 40S OVER THE PLAINS WHERE THERE WAS SUN...AND 30S WHERE IT WAS CLOUDY. THE SLV WAS IN THE 50S. REST OF TODAY INTO TONIGHT... RIDGING WILL BUILD OVER THE FCST AREA AND SKIES WILL CONTINUE TO CLEAR. A FEW CONVECTIVE SHOWERS WILL BE POSSIBLE OVER THE SAN JUANS AND S MTNS THE REST OF THIS AFTERNOON AND EARLY EVENING. OTHERWISE EXPECT CLEARING SKIES. THE ONLY CONCERN I HAVE FOR TONIGHT WILL BE PATCHY GROUND FOG IN PLACES. BASED ON CURRENT RH PROGS...BEST CHANCE FOR SOME FOG WILL BE OVER THE FAR E PLAINS...MAINLY ALONG THE ARK RVR. TEMPS TONIGHT WILL BE COOL WITH U20S TO L30S ACROSS THE PLAINS...AND 20S VALLEYS. THURSDAY... 500 MB RIDGE AXIS WILL BE OVER THE STATE BY LATE AFTERNOON. TEMP-WISE...TOMORROW WILL BE QUITE A NICE DAY WITH HIGHS IN THE L70S MOST OF THE PLAINS WITH 60S IN THE VALLEYS. SKIES WILL BE MOSTLY SUNNY. NO PRECIP IS EXPECTED. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 313 PM MDT WED APR 3 2013 SOME ADJUSTMENTS NEEDED DURING THE LONGER TERM WITH MAIN METEOROLOGICAL ISSUES CONTINUING TO BE TEMPERATURES...GUSTY WINDS AT TIMES...ELEVATED FIRE WEATHER CONCERNS FROM FRIDAY AFTERNOON INTO FRIDAY EVENING...THUNDERSTORM THREAT OVER PORTIONS OF THE FAR EASTERN PLAINS...ESPECIALLY FROM SUNDAY EVENING INTO SUNDAY NIGHT AND FINALLY THE IMPACT THAT UPPER SYSTEM WILL PRODUCE OVER THE FORECAST DISTRICT EARLY NEXT WEEK. IT STILL APPEARS THE RELATIVELY BENIGN AND MILD TO WARM METEOROLOGICAL CONDITIONS SHOULD BE NOTED OVER THE CWFA INTO FRIDAY...THANKS TO A TRANSITORY UPPER RIDGE MOVING ACROSS THE AREA. IN ADDITION...ELEVATED FIRE CONCERNS ARE STILL ANTICIPATED FROM FRIDAY AFTERNOON INTO FRIDAY EVENING...ESPECIALLY OVER PORTIONS OF FIRE WEATHER ZONES 222/224/225/228>233 AND 235 DUE TO PROJECTED LOW MINIMUM RELATIVE HUMIDITIES AND GUSTY WINDS AT TIMES. AS TOUCHED UPON IN PREVIOUS DISCUSSIONS...UPPER LEVEL DISTURBANCES...IMPACTING PRIMARILY NORTHERN PORTIONS OF THE FORECAST DISTRICT WITH INCREASED PRECIPITATION CHANCES ARE PROJECTED TO IMPACT THE CWFA FROM LATER FRIDAY INTO THE WEEKEND...ALLOWING FOR SOMEWHAT COOLER TEMPERATURES AS WELL AS GUSTY WINDS AT TIMES. IN ADDITION...INCREASED THUNDERSTORM CHANCES MAY BE NOTED OVER FAR EASTERN PORTIONS OF THE FORECAST DISTRICT FROM SUNDAY EVENING INTO SUNDAY NIGHT AS DEEPER ATMOSPHERIC MOISTURE INTERACTS WITH RELATIVELY HEALTHY 0 TO 6 KM BULK SHEARS. UPPER TROUGH SHOULD THEN IMPACT THE FORECAST DISTRICT BY EARLY NEXT WEEK WITH THE HIGHEST POTENTIAL FOR WIDESPREAD PRECIPITATION PROJECTED FROM LATER MONDAY INTO AT LEAST TUESDAY NIGHT. HAVE PAINTED GENERALLY SCATTERED POPS DURING THIS TIME-FRAME WITH A POTENTIAL FOR HEALTHY ACCUMULATING SNOW...ESPECIALLY OVER HIGHER TERRAIN AREAS. WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY. GUSTY WINDS WILL BE POSSIBLE FROM FRIDAY INTO FRIDAY NIGHT AND THEN AGAIN FROM NEXT TUESDAY INTO TUESDAY NIGHT. WARMEST TEMPERATURES OF THE LONGER TERM ARE EXPECTED FRIDAY WHILE COOLEST CONDITIONS ARE ANTICIPATED BY NEXT TUESDAY AND WEDNESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1058 PM MDT WED APR 3 2013 VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH THE NEXT 24 HOURS. A MINOR DISTURBANCE MOVING ACROSS NORTHEASTERN COLORADO WILL SPREAD SOME MID AND HIGH LEVEL MOISTURE ACROSS THE AREA THROUGH THE EARLY MORNING HOURS. THIS SYSTEM WILL ALSO SEND A WEAK BACK DOOR FRONT ACROSS THE EASTERN PLAINS THROUGH THE OVERNIGHT HOURS. LIGHT NORTHERLY WINDS BEHIND WEAK FRONT LOOKS TO INHIBIT FOG FORMATION ACROSS THE EASTERN PLAINS...WITH A DIURNAL WIND REGIME EXPECTED ONCE AGAIN THURSDAY AFTERNOON. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MW SHORT TERM...HODANISH LONG TERM...77 AVIATION...MW
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
347 AM EDT Thu Apr 4 2013 ...There is a slight risk for severe weather today... .NEAR TERM [Today]... The 03 UTC regional surface analysis showed a quasi-stationary front from north FL, to just south of the LA coast, to the southwest Gulf of Mexico. While a frontal wave appeared to be developing (as predicted by the NWP guidance) south of LA, the only low that I was able to close off appeared to be more of a mesoscale low about 30 miles south of Apalachicola, perhaps leftover from the wake low that brought some gusty winds to portions of our forecast area Wednesday afternoon and evening. Vapor imagery and upper air data showed an approaching trough centered over OK, but there were a few minor short waves well out ahead of this main system. All of the statistical and dynamical NWP guidance points to a rainy day for our region today, though just how much rain, and how stormy, is rather complicated. Since most of the 00 UTC NWP guidance didn`t initialize the meso low south of Apalachicola, it`s unclear how well they will handle the frontal system and main frontal wave developing to the west. Much of our thinking is based on the recent RAP run, which did initialize the various features quite well. We expect quite a bit of light rain early this morning, followed by increasing heavier showers and thunderstorms later this morning and afternoon as the low moves inland over the FL Panhandle. The band(s) of convection will move into our eastern zones this afternoon. Much of our forecast area is likely to get an additional 1 to 2 inches of rain from this system. The latest NSSL WRF, NCEP ARW/NMM, and our local 4km WRF show a couple of impressive tracks of max hourly updraft helicity (in terms of magnitude and longevity) this afternoon. The same can be said for integrated graupel. This would imply a threat for isolated supercell thunderstorms, capable of producing severe hail, damaging wind gusts, and/or even an isolated tornado. While this threat appears highest over the Gulf coastal waters and the FL Peninsula, there is a portion of our forecast area that is at risk as well- mainly along and south of a line from Apalachicola, through Tallahassee, to Moody AFB, Valdosta. This threat would be from late morning through mid to late afternoon. Actually, much of our forecast area is in a "Slight Risk" (15% probability of severe hail/wind, 5% tornado) of severe storms, but it may be more difficult to generate severe storms farther west and north than the section we just discussed, as the best deep layer moisture, forcing, and the 850mb jet stream will likely be farther east. && .SHORT TERM [Tonight Through Saturday]... By this evening, the severe potential, and possibly even the thunder potential will have diminished greatly from this afternoon. The only exception may be a few strong storms remaining across the extreme southeast Big Bend of Florida. Elsewhere light rain will persist through the night, especially across Georgia where the upper level shortwave will be able to tap into the best remaining moisture. A dry slot will likely spread from southwest to northeast through the night, putting a stop to the rain across portions of the Florida Panhandle and southeast Alabama. Showers will come to an end quickly on Friday, but clouds should remain for much of the day. This will hold temperatures in the 60s region-wide, with lower 60s possible across portions of central Georgia. Overnight Friday, temperatures will fall to a few degrees below seasonal averages, in the middle 40s for most locations. Dry conditions, mostly clear skies, and seasonal temperatures will finish off the period on Saturday. && .LONG TERM [Saturday Night through Wednesday]... The bulk of the extended forecast looks to be dry with gradually warming temperatures as a ridge of surface high pressure shifts from over the area on Saturday, to well off the Atlantic coast by Tuesday. This evolution will set up return flow early in the next work week, and highs into the 80s look likely. && .AVIATION [Beginning 07Z Thursday]... Occasional light rain (IFR-MVFR vis) is likely through today and into tonight. However, scattered +SHRA/TSRA will develop later this morning, affecting the terminals with locally gusty winds and heavy downpours until mid to late afternoon. IFR to occasionally LIFR cigs are likely through this morning. They will gradually lift to low-end MVFR levels by late morning or early afternoon. The guidance differs on how long these cigs will persist after 00 UTC tonight, so we will just keep the MVFR cigs through the end of this TAF package. && .MARINE... Advisory level conditions are expected ahead of developing low pressure today. In the wake of the low, another brief round of advisory conditions are anticipated. Winds and seas will fall below headline levels by the weekend, and remain that way through at least early next week under the influence of high pressure. && .FIRE WEATHER... Moist conditions will persist through Friday, helping to keep ERC values low. A drier airmass will move into the region Saturday, but at this time it doesn`t appear that Red Flag conditions are likely, especially since the winds won`t be very strong and the fuels may be rather damp. && .HYDROLOGY... With round 1 of the rain complete, we have seen storm totals thus far between an inch and an inch and a half across the southeast Big Bend of Florida and around a half of an inch across portions of south central Georgia east of the Flint River and along the Florida Panhandle coast. The light rain from overnight will continue to gradually spread north through the first part of the day today. Later today, another round of moderate to heavy rain is expected, with the bulk of the rain falling along and east of the Flint and Apalachicola Rivers. In these locations another 1 to 2 inches will be possible, with the highest amounts expected across the southeast Big Bend, in the lower Suwannee River basins. With the eastward shift in expected rainfall, ensemble guidance suggests that most area rivers will only flirt with the lower end of Action stage. In fact, the lower Suwannee appears capable of handling the projected rainfall without climbing to Action stage for most of our forecast points. When all is said and done there should be little in the way of impacts along area rivers this weekend. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 73 56 67 46 76 / 80 60 20 0 0 Panama City 71 57 67 53 74 / 70 40 20 0 0 Dothan 66 51 66 44 74 / 70 50 20 0 0 Albany 64 48 65 45 75 / 80 70 30 0 0 Valdosta 71 55 66 46 76 / 90 70 40 10 0 Cross City 73 62 70 45 78 / 90 80 30 10 0 Apalachicola 70 59 66 52 71 / 70 40 20 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...Small Craft Advisory until 5 PM EDT Friday for Gulf of Mexico waters from Destin to the Suwannee River out to 60 NM. && $$ NEAR TERM...Fournier SHORT TERM...Harrigan LONG TERM...Lamers AVIATION...Fournier MARINE...Harrigan FIRE WEATHER...Fournier HYDROLOGY...Harrigan
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
330 AM EDT THU APR 4 2013 .SYNOPSIS... LOW PRESSURE PASSES SOUTH LATE TODAY AND TONIGHT WITH THE CHANCE FOR RAIN. MODERATING TEMPERATURES OVER THE WEEKEND. FRONT NEARBY SUNDAY INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... MDLS COMING IN A BIT FASTER WITH ONSET OF PCPN LATER TDY AS SFC LOW ORGANIZES ALONG GA/SC COAST. HOWEVER VERY DRY LLVLS WILL BE BATTLING MOISTURE ADVECTION FROM S. AS SUCH DID NOT GO AS FAST AS MDLS SUGGEST ONCE INTO S WV PLATEAU. LATEST RAP MDL SEEMS TO HAVE A BETTER REFLECTION OF CURRENT THINKING AND USED IT AS A GUIDE THRU 00Z. DO BRING IN HIGH POPS ACROSS SW VA BY 18Z AND THEN SLOWLY SPREAD N UP THE EASTERN SLOPES TO INCLUDE MUCH OF POCAHONTAS CO WITH THE CATEGORICAL POPS. HAVE A SHARP GRADIENT HEADING W...WITH CHC POPS EXTENDING TO CRW- HTS AREA AND UP TOWARD CKB. FEEL SE OH AND NW LOWLAND CO STAY DRY. HAVE ARND A THIRD OF AN INCH QPF FOR SW VA AND UP THE EASTERN SLOPES. QUICKLY TAILS OF W OF I79 CORRIDOR. EXIT BULK OF PCPN BY 06Z TO THE E...WITH LINGERING CHC POPS FOR S/W TROF AXIS SLIDING THRU. THERE IS SOME CONCERN FOR WINTRY PCPN AT THE ONSET ACROSS RIDGES IN POCAHONTAS CO. MDLS INDICATE GOOD WET BULBING ARND 00Z TO REFLECT SOME WET SN OR MIX POTENTIAL BEFORE SWITCHING TO RA LATER IN EVE. USED SFC AND MODEL ALOFT TOO TO REFLECT THIS IN WX GRIDS. WILL KEEP ACCUMULATIONS OUT OF GRIDS FOR NOW THOUGH. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... MODELS IN GOOD AGREEMENT SHOWING SYSTEM PULLING OFF TO THE EAST EARLY FRIDAY...WITH DRY WEATHER EXPECTED BY MIDDAY. WILL SPEED UP THE EXODUS OF THE POPS. MOS GUIDANCE FOR HIGHS ON FRIDAY HAS BEEN TRENDING DOWNWARD...BUT STILL LOOKS TOO HIGH. HAVE UNDERCUT MOS ONCE AGAIN FOR HIGHS FRIDAY...AND ALSO ON SATURDAY. A COLD FRONT THEN PUSHES INTO THE AREA ON SUNDAY...BEFORE STALLING OVER THE AREA. SOME DEBATE AMONG THE MODELS ON WHERE THE FRONT WILL STALL. CURRENT FORECAST LOOKS LIKE A GOOD COMPROMISE FOR NOW...SO DID NOT CHANGE WITH THE EXCEPTION OF SLOWING THE ARRIVAL OF THE SHOWERS. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... WAVY FRONT APPROACHES THIS WEEKEND AND THEN HANGS NEARBY THE BALANCE OF THE PERIOD. RIDGING ADVERTISED FOR EARLY NEXT WEEK OVER THE PAST FEW DAYS IS ALL BUT GONE...THE GFS STILL AMPLIFYING ONE BUT ALONG THE E COAST TUE. THAT IS WHEN THE ECMWF IS MARKEDLY DIFFERENT WITH THE NORTHERN STREAM OVER CANADA...USING EASTERN CANADIAN TROUGHING TO SINK THE CONFLUENCE...AND FRONTAL ZONE...SWD. THIS WOULD MAKE THE LATTER PORTION OF THE FCST MUCH WETTER AND COOLER THAN CURRENTLY CODED. AS PER HPC...IT AND TELECONNECTIONS DEPENDENT UPON SW CONUS TROUGH WILL PLAY A ROLE IN HOW FAR N THE FRONT IS OVER THE EASTERN CONUS DAYS 6-7. DRY WEATHER GIVES WAY TO INCREASING CHANCE FOR SHOWERS NW TO SE DAY 3 NT AND DAY 4 WITH INITIAL APPROACH OF FRONT AND INITIAL UPPER LEVEL WAVE. KEEP CHANCE THROUGH THE BALANCE OF THE FCST...HIGHEST N AND NW...LOWEST S AND SE...HAVE HAVE JUST SLIGHT CHANCE EARLY ON. MORE OR LESS EQUAL CHANCE FOR PRECIPITATION THROUGHOUT THE AREA DAY 7. ALSO INTRODUCED SLIGHT CHANCE FOR THUNDER DURING THE AFTERNOONS AND EARLY EVENINGS BEGINNING MON AS DEW POINTS INCREASE TO NEAR 50. BLENDED IN ADJMEXBC FOR HIGHS EARLY ON AND THEN HPC DAYS 6 AND 7 HIGHS AND ALL LOWS. ADJMEXBC APPEARED TOO LOW ON LOWS GIVEN SW FLOW...RISING DEW POINTS AND CLOUDS. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... 06Z THURSDAY TO 06Z FRIDAY... LIGHT SURFACE WINDS BECOMING GUSTY AGAIN AFTER 15Z...PARTICULARLY ACROSS THE HIGHER TERRAIN. A LOW PRESSURE SYSTEM WILL APPROACH FROM THE SOUTH LATE TDY...ALLOWING RA TO OVERSPREAD SW VA BY 18Z AND SLOWLY SPREADING N UP THE WV MTNS. THIS WILL CREATE GENERAL MVFR CONDITIONS ACROSS SOUTHWEST VA 18Z...SOUTHERN WV BY 00Z... AND UP WV MTNS BY 03Z. KEEP SOUTHEAST OHIO AND NORTHERN WV REMAINING VFR IN MID DECK. KHTS AND KCRW TRICKY AS THEY WILL BE ON THE NW FRINGE OF BEST LLVL MOISTURE AND PCPN. WILL KEEP THEM VFR WITH THIS ISSUANCE BUT ALLOW CIGS TO LWR INTO LOW END VFR. KEPT SHRA MENTION OUT OF THOSE LOCALES DUE TO LOW CHC AT THIS RANGE. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY... FORECAST CONFIDENCE...MEDIUM. ALTERNATE SCENARIOS: LOW PRESSURE SYSTEM MAY SPREAD MOISTURE AND LOW CIGS FARTHER NORTH THAN CURRENTLY FORECAST TOWARDS THE END OF THE TAF PERIOD. 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. DATE THU 04/04/13 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 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 H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 06Z FRIDAY... NO WIDESPREAD IFR CONDITIONS EXPECTED. && .FIRE WEATHER... RH VALUES WILL AGAIN DIP INTO TEENS AND 20S PERCENT WISE AS DWPTS MIX DOWN INTO THE TEENS AND TEMPS CLIMB. MOISTURE ADV FROM S IN AFTN SHOULD ALLOW RH TO RECOVER UP TO CENTRAL WV WITH RA ACROSS SW VA. HOWEVER...ACROSS PORTIONS OF NE KY...SE OH AND N WV...THE DRY AIR WILL PREVAIL TDY. SOME AFTN GUSTS ARND 15 KTS MAY ALSO BE EXPECTED ACROSS N WV. WITH VERY DRY 10 HR FUELS IN PLACE...AN ENHANCED FIRE DANGER THREAT MAY BE REALIZED TODAY. CONDITIONS WILL BE MONITORED AND COORDINATED WITH THE APPROPRIATE STATE FORESTRY PERSONNEL FOR THE POTENTIAL FOR ANY FIRE WEATHER STATEMENTS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/RPY/30 NEAR TERM...30 SHORT TERM...RPY LONG TERM...TRM AVIATION...30 FIRE WEATHER...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
255 AM EDT THU APR 4 2013 .SYNOPSIS... LOW PRESSURE PASSES SOUTH LATE TODAY AND TONIGHT WITH THE CHANCE FOR RAIN. MODERATING TEMPERATURES OVER THE WEEKEND. FRONT NEARBY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... MDLS COMING IN A BIT FASTER WITH ONSET OF PCPN LATER TDY AS SFC LOW ORGANIZES ALONG GA/SC COAST. HOWEVER VERY DRY LLVLS WILL BE BATTLING MOISTURE ADVECTION FROM S. AS SUCH DID NOT GO AS FAST AS MDLS SUGGEST ONCE INTO S WV PLATEAU. LATEST RAP MDL SEEMS TO HAVE A BETTER REFLECTION OF CURRENT THINKING AND USED IT AS A GUIDE THRU 00Z. DO BRING IN HIGH POPS ACROSS SW VA BY 18Z AND THEN SLOWLY SPREAD N UP THE EASTERN SLOPES TO INCLUDE MUCH OF POCAHONTAS CO WITH THE CATEGORICAL POPS. HAVE A SHARP GRADIENT HEADING W...WITH CHC POPS EXTENDING TO CRW- HTS AREA AND UP TOWARD CKB. FEEL SE OH AND NW LOWLAND CO STAY DRY. HAVE ARND A THIRD OF AN INCH QPF FOR SW VA AND UP THE EASTERN SLOPES. QUICKLY TAILS OF W OF I79 CORRIDOR. EXIT BULK OF PCPN BY 06Z TO THE E...WITH LINGERING CHC POPS FOR S/W TROF AXIS SLIDING THRU. THERE IS SOME CONCERN FOR WINTRY PCPN AT THE ONSET ACROSS RIDGES IN POCAHONTAS CO. MDLS INDICATE GOOD WET BULBING ARND 00Z TO REFLECT SOME WET SN OR MIX POTENTIAL BEFORE SWITCHING TO RA LATER IN EVE. USED SFC AND MODEL ALOFT TOO TO REFLECT THIS IN WX GRIDS. WILL KEEP ACCUMULATIONS OUT OF GRIDS FOR NOW THOUGH. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... STILL SOME DISAGREEMENT IN THE MODELS WITH TRACK AND TIMING OF THE SURFACE LOW FOR THURSDAY NIGHT INTO FRIDAY. NAM HAS TRENDED MUCH FATHER SOUTH...BUT HAS THE SURFACE LOW AROUND THE MOUTH OF CHESAPEAKE BAY...WHILE GFS AND ECMWF SHOW AN ELONGATED LOW FROM THE CHESAPEAKE DOWN TO SOUTH CAROLINA. WITH THE NAM TRENDING SOUTH TIGHTENED THE GRADIENT IN POPS ACROSS OUR CWA...GOING DRY ALONG AND NW OF THE OHIO RIVER WHILE KEEPING LIKELY IN SW VA AND THE SOUTHERN COAL FIELDS AND SOUTHERN AND CENTRAL MOUNTAINS OF WV. PRECIP IS ALSO FASTER EXITING OUR CWA...SO TRENDED THAT WAY WITH POPS AS ANOTHER SURFACE HIGH MOVES IN FRIDAY NIGHT. ONLY SMALL CHANGES MADE ON TEMPS THURSDAY NIGHT THROUGH FRIDAY NIGHT...BUT DID INCREASE HIGHS SOME ON SATURDAY WITH PLENTY OF APRIL SUNSHINE. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... WAVY FRONT APPROACHES THIS WEEKEND AND THEN HANGS NEARBY THE BALANCE OF THE PERIOD. RIDGING ADVERTISED FOR EARLY NEXT WEEK OVER THE PAST FEW DAYS IS ALL BUT GONE...THE GFS STILL AMPLIFYING ONE BUT ALONG THE E COAST TUE. THAT IS WHEN THE ECMWF IS MARKEDLY DIFFERENT WITH THE NORTHERN STREAM OVER CANADA...USING EASTERN CANADIAN TROUGHING TO SINK THE CONFLUENCE...AND FRONTAL ZONE...SWD. THIS WOULD MAKE THE LATTER PORTION OF THE FCST MUCH WETTER AND COOLER THAN CURRENTLY CODED. AS PER HPC...IT AND TELECONNECTIONS DEPENDENT UPON SW CONUS TROUGH WILL PLAY A ROLE IN HOW FAR N THE FRONT IS OVER THE EASTERN CONUS DAYS 6-7. DRY WEATHER GIVES WAY TO INCREASING CHANCE FOR SHOWERS NW TO SE DAY 3 NT AND DAY 4 WITH INITIAL APPROACH OF FRONT AND INITIAL UPPER LEVEL WAVE. KEEP CHANCE THROUGH THE BALANCE OF THE FCST...HIGHEST N AND NW...LOWEST S AND SE...HAVE HAVE JUST SLIGHT CHANCE EARLY ON. MORE OR LESS EQUAL CHANCE FOR PRECIPITATION THROUGHOUT THE AREA DAY 7. ALSO INTRODUCED SLIGHT CHANCE FOR THUNDER DURING THE AFTERNOONS AND EARLY EVENINGS BEGINNING MON AS DEW POINTS INCREASE TO NEAR 50. BLENDED IN ADJMEXBC FOR HIGHS EARLY ON AND THEN HPC DAYS 6 AND 7 HIGHS AND ALL LOWS. ADJMEXBC APPEARED TOO LOW ON LOWS GIVEN SW FLOW...RISING DEW POINTS AND CLOUDS. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... 06Z THURSDAY TO 06Z FRIDAY... LIGHT SURFACE WINDS BECOMING GUSTY AGAIN AFTER 15Z...PARTICULARLY ACROSS THE HIGHER TERRAIN. A LOW PRESSURE SYSTEM WILL APPROACH FROM THE SOUTH LATE TDY...ALLOWING RA TO OVERSPREAD SW VA BY 18Z AND SLOWLY SPREADING N UP THE WV MTNS. THIS WILL CREATE GENERAL MVFR CONDITIONS ACROSS SOUTHWEST VA 18Z...SOUTHERN WV BY 00Z... AND UP WV MTNS BY 03Z. KEEP SOUTHEAST OHIO AND NORTHERN WV REMAINING VFR IN MID DECK. KHTS AND KCRW TRICKY AS THEY WILL BE ON THE NW FRINGE OF BEST LLVL MOISTURE AND PCPN. WILL KEEP THEM VFR WITH THIS ISSUANCE BUT ALLOW CIGS TO LWR INTO LOW END VFR. KEPT SHRA MENTION OUT OF THOSE LOCALES DUE TO LOW CHC AT THIS RANGE. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY... FORECAST CONFIDENCE...MEDIUM. ALTERNATE SCENARIOS: LOW PRESSURE SYSTEM MAY SPREAD MOISTURE AND LOW CIGS FARTHER NORTH THAN CURRENTLY FORECAST TOWARDS THE END OF THE TAF PERIOD. 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. DATE THU 04/04/13 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 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 H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 06Z FRIDAY... NO WIDESPREAD IFR CONDITIONS EXPECTED. && .FIRE WEATHER... RH VALUES WILL AGAIN DIP INTO TEENS AND 20S PERCENT WISE AS DWPTS MIX DOWN INTO THE TEENS AND TEMPS CLIMB. MOISTURE ADV FROM S IN AFTN SHOULD ALLOW RH TO RECOVER UP TO CENTRAL WV WITH RA ACROSS SW VA. HOWEVER...ACROSS PORTIONS OF NE KY...SE OH AND N WV...THE DRY AIR WILL PREVAIL TDY. SOME AFTN GUSTS ARND 15 KTS MAY ALSO BE EXPECTED ACROSS N WV. WITH VERY DRY 10 HR FUELS IN PLACE...AN ENHANCED FIRE DANGER THREAT MAY BE REALIZED TODAY. CONDITIONS WILL BE MONITORED AND COORDINATED WITH THE APPROPRIATE STATE FORESTRY PERSONNEL FOR THE POTENTIAL FOR ANY FIRE WEATHER STATEMENTS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/RPY/30 NEAR TERM...30 SHORT TERM...MZ LONG TERM...TRM AVIATION...30 FIRE WEATHER...30
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
505 AM EDT THU APR 4 2013 .SYNOPSIS... LOW PRESSURE WAS OVER THE NORTHERN GULF OF MEXICO THIS MORNING WITH HIGH PRESSURE OVER THE MID ATLANTIC REGION. THE LOW WILL MOVE ACROSS GEORGIA AND FLORIDA TODAY THEN OFF THE CAROLINA COAST BY FRIDAY MORNING. HIGH PRESSURE WILL COVER THE REGION BEHIND THIS SYSTEM FOR SATURDAY AND SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 430 AM EDT THURSDAY... STARTING WITH SURFACE DEW POINTS IN THE SINGLE DIGITS AND TEENS AND A LOT OF ROOM TO COOL DOWN TO THE WET BULB AS MOISTURE INCREASES FROM THE TOP DOWN. LATEST RUNS OF THE RAP AND LOCAL WRF SUGGEST SLOW PROGRESS OF THE LEADING EDGE OF THE PRECIPITATION INTO THE DRY AIR. HAVE SLOWED DOWN THE ARRIVAL TIME IN THE NORTHERN COUNTY WARNING AREA TODAY. FOR PRECIPITATION TYPE...BUFKIT FORECAST SOUNDINGS ALONG THE SOUTHERN BLUE RIDGE SHOW SNOW AND SLEET FOR MUCH OF THE DAY. HAVE ISSUED A WINTER WEATHER ADVISORY FOR WATAUGA COUNTY...EXPECTING THE HIGHEST SNOW AND SLEET AMOUNTS ALONG THE AVERY COUNTY LINE. BEECH MOUNTAIN MAY HAVE 3 INCHES OF NEW SNOW/SLEET TODAY. AS PRECIPITATION MOVES INTO THE FORECAST AREA THIS MORNING...IN-SITU WEDGE FORMS. ALREADY STARTING OUT CLOUDY AND WITH PRECIPITATION TEMPERATURES WILL REMAIN BELOW NORMAL. USED A NON DIURNAL TREND FOR HOURLY TEMPERATURES. BEST ISENTROPIC LIFT AND UPPER DIFFLUENCE CROSS THROUGH THE AREA AREA BETWEEN 18Z/2PM AND 06Z/2AM. PROBABILITY OF PRECIPITATION BEGINS TO LOWER IN THE MOUNTAINS AS THE LOW COMING ACROSS THE GULF COAST STATES MOVES OFFSHORE AND WINDS COME AROUND TO THE NORTHWEST. && .SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/... AS OF 400 AM EDT THURSDAY... BY SUNRISE FRIDAY...THE GFS AND ECMWF FORECAST MODELS ARE IN DECENT AGREEMENT THAT THE LOW PRESSURE SYSTEM WHICH BROUGHT RAIN TO OUR AREA EARLIER IN THE NIGHT WILL BE MOVING RAPIDLY UP THE NORTH CAROLINA COAST. AS THE LOW CONTINUES NORTHEAST...WINDS ACROSS OUR AREA WILL BECOME INCREASINGLY NORTHWESTERLY...DRAWING DRIER AIR IN FROM THE GREAT LAKES. AS SUCH...SHOWER ACTIVITY WILL TAPER OFF THROUGH THE MORNING...AND EXPECT TO SEE CLOUD COVER BREAK UP FROM WEST TO EAST DURING THE AFTERNOON. A RIDGE OF HIGH PRESSURE WILL PASS ACROSS THE APPALACHIAN CHAIN FRIDAY NIGHT...AND WILL MOVE OFF OF THE ATLANTIC COAST SATURDAY AFTERNOON. DESPITE ABUNDANT AFTERNOON SUNSHINE...EASTERLY WINDS FLOWING AROUND THE DEPARTING HIGH PRESSURE RIDGE WILL CARRY COOLER AIR FROM THE ATLANTIC INTO OUR AREA. THEREFORE...UNDERCUT GUIDANCE BY A FEW DEGREES FOR SATURDAY AFTERNOON TEMPERATURES...LIMITING HIGHS TO THE UPPER 50S AND THE LOW 60S FOR MOST OF THE AREA. BY SUNDAY...AN UPPER LEVEL TROUGH BEGINS TO SET IN ACROSS THE WESTERN HALF OF THE UNITED STATES...ALLOWING UPPER LEVEL RIDGING ACROSS THE EASTERN HALF TO BECOME INCREASINGLY AMPLIFIED. AS SUCH...SUNDAY AFTERNOON TEMPERATURES WILL BE AMONG THE WARMEST EXPERIENCED THIS YEAR...WITH HIGHS REACHING TO NEAR 70 ACROSS THE PIEDMONTS...AND INTO THE MID/UPPER 60S ACROSS THE MOUNTAINS. A COLD FRONT WILL SINK FROM THE GREAT LAKES AS FAR SOUTH AS THE OHIO RIVER VALLEY DURING THE AFTERNOON...HOWEVER ANOTHER DEVELOPING LOW PRESSURE SYSTEM ACROSS THE PLAINS WILL CAUSE THE FRONT TO STALL BEFORE REACHING INTO OUR AREA. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 400 AM EDT THURSDAY... THE LONG TERM PERIOD WILL BE CHARACTERIZED BY BUILDING 500MB HEIGHTS...INCREASING MOISTURE...AND WARMER TEMPERATURES AS A WESTERN U.S. TROF CONTINUES TO DEEPEN. UPPER LEVEL HEIGHTS WILL REALLY BEGIN TO RISE MONDAY AS THE WESTERN TROF DEEPENS. THE 00Z ECMWF APPEARS TOO FAR EAST WITH THIS SYSTEM...AND LEANED TOWARD THE CANADIAN/GFS MODELS KEEPING A SOUTHWEST FLOW OVER OUR AREA RESULTING IN OUR FIRST TASTE OF ABOVE NORMAL TEMPERATURES IN WEEKS. MEANWHILE...AT THE SFC... SOUTH/SOUTHWEST WINDS USHER IN HIGHER DEWPOINTS...DEEPER MOISTURE WITH PWATS 1-2 STANDARD DEVIATIONS ABOVE NORMAL...TUESDAY AND WEDNESDAY. WEAK UPPER LEVEL WAVES IN ADVANCE OF THE DEEPENING TROF INTERACTING WITH THIS INCREASING MOISTURE WILL BRING A SLIGHT CHANCE OF SHOWERS TUESDAY AND WEDNESDAY. THE 12Z GFS SUGGESTS A DRIER DAY TUESDAY WITH A MORE AMPLIFIED PATTERN COMPARED TO PREVIOUS MODEL RUNS...KEEPING THE BEST UPPER LEVEL SUPPORT/LOW LEVEL CONVERGENCE WELL WEST OF OUR AREA. A DEEP SOUTHWEST FLOW WILL KEEP ABOVE NORMAL TEMPS...MOSTLY CLOUDY SKIES AND A RISK OF SHOWERS/ISOLATED STORMS ON WEDNESDAY. && .AVIATION /09Z THURSDAY THROUGH MONDAY/... AS OF 140 AM EDT THURSDAY... CEILINGS WILL LOWER OVER VIRGINIA AND THE CAROLINAS AS DEEPER MOISTURE MOVES NORTHEAST OUT OF THE TENNESSEE VALLEY. RAIN ARRIVES AFTER 18Z/2PM WITH MVFR CEILINGS BY 00Z/8PM. MEDIUM CONFIDENCE ON THE TIMING OF THE RAIN AND MVFR CONDITIONS. RAIN AND MVFR TO IFR CEILINGS AND VISIBILITIES ARE EXPECTED OVERNIGHT. EASTERLY SURFACE AND LOW LEVEL WINDS WILL LIKELY BRING IFR CONDITIONS TO ROA/LYH AND DAN AFTER 06Z. BY FRIDAY THE STORM SYSTEM WILL BE OFF THE EAST COAST. LOW LEVEL MOISTURE WILL REMAIN OVER THE MOUNTAINS...RESULTING IN PROLONGED MVFR CEILINGS AT LWB/BLF. CONDITIONS WILL BE GRADUALLY IMPROVING EAST OF THE BLUE RIDGE BY LATE FRIDAY. HIGH PRESSURE WILL THEN BUILD IN FOR SATURDAY...BRINGING DRY WEATHER AND RETURNING ALL TAF LOCATIONS TO VFR THROUGH MONDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...WINTER WEATHER ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NCZ018. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...NF LONG TERM...NF/PH AVIATION...AMS
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1000 AM EDT Thu Apr 4 2013 .NEAR TERM [Rest of Today]... Updated at: 1000 AM EDT Early indications this morning are that severe weather potential is becoming increasingly marginal for today across our area. Limiting factors include: 1. Cirrus shield currently spread north from convection over the C/EC Gulf of Mexico that may limit heating, or delay the scattering of low cloud decks 2. A pronounced inversion around 650mb (via 12z TAE sounding) due to the arrival of an EML aloft. 3. Deeper moisture situated well to the south over the Gulf and the Florida peninsula. Essentially, the atmosphere is going to have to do a lot of work in order to be more conducive for severe thunderstorms, and that is looking less and less likely with time in our forecast area. 12z RAP analysis shows that at 700mb, the pocket of warmest air is actually situated just overhead at the moment. Meanwhile, a subtle shortwave and jet max aloft near the Louisiana coastline (per water vapor) was propagating ENE, and RAP analysis suggested that 700mb temperatures were about 2-3C cooler near this feature. Therefore, it`s possible that as mid-level height falls commence and stronger upper level forcing arrives, that the inversion layer aloft will slowly erode. However, even 2-3C of cooling in that layer would still leave us with a rather marginal instability profile. What would be most likely would be shallow rain showers with isolated thunderstorms, increasing in coverage for a brief time as the shortwave approaches. Extrapolation of the shortwave would take it into our area around 18-21z. The changes that were made to the grids to account for all this was to reduce the sensible weather across most of the area to just rain showers with isolated thunderstorms, and time the peak in PoPs more for the early to mid afternoon. Despite all of these factors, it is not possible to totally rule out a stronger storm or two this afternoon. There is still a fair amount of uncertainty in the assessment of various mesoscale features, so we will continue to highlight a risk of severe storms in the HWO. Any strong or severe storms, however, should be rather isolated. && .SHORT TERM [Tonight Through Saturday]... By this evening, the severe potential, and possibly even the thunder potential will have diminished greatly from this afternoon. The only exception may be a few strong storms remaining across the extreme southeast Big Bend of Florida. Elsewhere light rain will persist through the night, especially across Georgia where the upper level shortwave will be able to tap into the best remaining moisture. A dry slot will likely spread from southwest to northeast through the night, putting a stop to the rain across portions of the Florida Panhandle and southeast Alabama. Showers will come to an end quickly on Friday, but clouds should remain for much of the day. This will hold temperatures in the 60s region-wide, with lower 60s possible across portions of central Georgia. Overnight Friday, temperatures will fall to a few degrees below seasonal averages, in the middle 40s for most locations. Dry conditions, mostly clear skies, and seasonal temperatures will finish off the period on Saturday. && .LONG TERM [Saturday Night through Wednesday]... The bulk of the extended forecast looks to be dry with gradually warming temperatures as a ridge of surface high pressure shifts from over the area on Saturday, to well off the Atlantic coast by Tuesday. This evolution will set up return flow early in the next work week, and highs into the 80s look likely. && .AVIATION [through 12 UTC Friday]... Occasional light rain is likely this morning. However, scattered +SHRA/TSRA will develop later this morning, affecting KECP, KTLH, and KVLD with locally gusty winds and heavy downpours until mid afternoon. LIFR-IFR cigs will gradually lift to low-end MVFR levels by late morning or early afternoon. Although most of the rain will move east of the region later this afternoon, IFR-LIFR cigs are likely to return to all terminals tonight. && .MARINE... Advisory level conditions are expected ahead of developing low pressure today. In the wake of the low, another brief round of advisory conditions are anticipated. Winds and seas will fall below headline levels by the weekend, and remain that way through at least early next week under the influence of high pressure. && .FIRE WEATHER... Moist conditions will persist through Friday, helping to keep ERC values low. A drier airmass will move into the region Saturday, but at this time it doesn`t appear that Red Flag conditions are likely, especially since the winds won`t be very strong and the fuels may be rather damp. && .HYDROLOGY... With round 1 of the rain complete, we have seen storm totals thus far between an inch and an inch and a half across the southeast Big Bend of Florida and around a half of an inch across portions of south central Georgia east of the Flint River and along the Florida Panhandle coast. The light rain from overnight will continue to gradually spread north through the first part of the day today. Later today, another round of moderate to heavy rain is expected, with the bulk of the rain falling along and east of the Flint and Apalachicola Rivers. In these locations another 1 to 2 inches will be possible, with the highest amounts expected across the southeast Big Bend, in the lower Suwannee River basins. With the eastward shift in expected rainfall, ensemble guidance suggests that most area rivers will only flirt with the lower end of Action stage. In fact, the lower Suwannee appears capable of handling the projected rainfall without climbing to Action stage for most of our forecast points. When all is said and done there should be little in the way of impacts along area rivers this weekend. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 73 56 67 46 76 / 50 40 20 0 0 Panama City 71 57 67 53 74 / 40 40 20 0 0 Dothan 66 51 66 44 74 / 30 40 20 0 0 Albany 64 48 65 45 75 / 40 40 30 0 0 Valdosta 71 55 66 46 76 / 50 40 40 10 0 Cross City 73 62 70 45 78 / 40 50 30 10 0 Apalachicola 70 59 66 52 71 / 40 30 20 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...Small Craft Advisory until 5 PM EDT Friday for Gulf of Mexico waters from Destin to the Suwannee River out to 60 NM. && $$ NEAR TERM...Lamers SHORT TERM...Harrigan LONG TERM...Lamers AVIATION...Fournier MARINE...Harrigan FIRE WEATHER...Fournier HYDROLOGY...Harrigan
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
630 AM EDT Thu Apr 4 2013 ...There is a slight risk for severe weather today... .NEAR TERM [Today]... The 03 UTC regional surface analysis showed a quasi-stationary front from north FL, to just south of the LA coast, to the southwest Gulf of Mexico. While a frontal wave appeared to be developing (as predicted by the NWP guidance) south of LA, the only low that I was able to close off appeared to be more of a mesoscale low about 30 miles south of Apalachicola, perhaps leftover from the wake low that brought some gusty winds to portions of our forecast area Wednesday afternoon and evening. Vapor imagery and upper air data showed an approaching trough centered over OK, but there were a few minor short waves well out ahead of this main system. All of the statistical and dynamical NWP guidance points to a rainy day for our region today, though just how much rain, and how stormy, is rather complicated. Since most of the 00 UTC NWP guidance didn`t initialize the meso low south of Apalachicola, it`s unclear how well they will handle the frontal system and main frontal wave developing to the west. Much of our thinking is based on the recent RAP run, which did initialize the various features quite well. We expect quite a bit of light rain early this morning, followed by increasing heavier showers and thunderstorms later this morning and afternoon as the low moves inland over the FL Panhandle. The band(s) of convection will move into our eastern zones this afternoon. Much of our forecast area is likely to get an additional 1 to 2 inches of rain from this system. The latest NSSL WRF, NCEP ARW/NMM, and our local 4km WRF show a couple of impressive tracks of max hourly updraft helicity (in terms of magnitude and longevity) this afternoon. The same can be said for integrated graupel. This would imply a threat for isolated supercell thunderstorms, capable of producing severe hail, damaging wind gusts, and/or even an isolated tornado. While this threat appears highest over the Gulf coastal waters and the FL Peninsula, there is a portion of our forecast area that is at risk as well- mainly along and south of a line from Apalachicola, through Tallahassee, to Moody AFB, Valdosta. This threat would be from late morning through mid to late afternoon. Actually, much of our forecast area is in a "Slight Risk" (15% probability of severe hail/wind, 5% tornado) of severe storms, but it may be more difficult to generate severe storms farther west and north than the section we just discussed, as the best deep layer moisture, forcing, and the 850mb jet stream will likely be farther east. && .SHORT TERM [Tonight Through Saturday]... By this evening, the severe potential, and possibly even the thunder potential will have diminished greatly from this afternoon. The only exception may be a few strong storms remaining across the extreme southeast Big Bend of Florida. Elsewhere light rain will persist through the night, especially across Georgia where the upper level shortwave will be able to tap into the best remaining moisture. A dry slot will likely spread from southwest to northeast through the night, putting a stop to the rain across portions of the Florida Panhandle and southeast Alabama. Showers will come to an end quickly on Friday, but clouds should remain for much of the day. This will hold temperatures in the 60s region-wide, with lower 60s possible across portions of central Georgia. Overnight Friday, temperatures will fall to a few degrees below seasonal averages, in the middle 40s for most locations. Dry conditions, mostly clear skies, and seasonal temperatures will finish off the period on Saturday. && .LONG TERM [Saturday Night through Wednesday]... The bulk of the extended forecast looks to be dry with gradually warming temperatures as a ridge of surface high pressure shifts from over the area on Saturday, to well off the Atlantic coast by Tuesday. This evolution will set up return flow early in the next work week, and highs into the 80s look likely. && .AVIATION [through 12 UTC Friday]... Occasional light rain is likely this morning. However, scattered +SHRA/TSRA will develop later this morning, affecting KECP, KTLH, and KVLD with locally gusty winds and heavy downpours until mid afternoon. LIFR-IFR cigs will gradually lift to low-end MVFR levels by late morning or early afternoon. Although most of the rain will move east of the region later this afternoon, IFR-LIFR cigs are likely to return to all terminals tonight. && .MARINE... Advisory level conditions are expected ahead of developing low pressure today. In the wake of the low, another brief round of advisory conditions are anticipated. Winds and seas will fall below headline levels by the weekend, and remain that way through at least early next week under the influence of high pressure. && .FIRE WEATHER... Moist conditions will persist through Friday, helping to keep ERC values low. A drier airmass will move into the region Saturday, but at this time it doesn`t appear that Red Flag conditions are likely, especially since the winds won`t be very strong and the fuels may be rather damp. && .HYDROLOGY... With round 1 of the rain complete, we have seen storm totals thus far between an inch and an inch and a half across the southeast Big Bend of Florida and around a half of an inch across portions of south central Georgia east of the Flint River and along the Florida Panhandle coast. The light rain from overnight will continue to gradually spread north through the first part of the day today. Later today, another round of moderate to heavy rain is expected, with the bulk of the rain falling along and east of the Flint and Apalachicola Rivers. In these locations another 1 to 2 inches will be possible, with the highest amounts expected across the southeast Big Bend, in the lower Suwannee River basins. With the eastward shift in expected rainfall, ensemble guidance suggests that most area rivers will only flirt with the lower end of Action stage. In fact, the lower Suwannee appears capable of handling the projected rainfall without climbing to Action stage for most of our forecast points. When all is said and done there should be little in the way of impacts along area rivers this weekend. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 73 56 67 46 76 / 80 60 20 0 0 Panama City 71 57 67 53 74 / 70 40 20 0 0 Dothan 66 51 66 44 74 / 70 50 20 0 0 Albany 64 48 65 45 75 / 80 70 30 0 0 Valdosta 71 55 66 46 76 / 90 70 40 10 0 Cross City 73 62 70 45 78 / 90 80 30 10 0 Apalachicola 70 59 66 52 71 / 70 40 20 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...Small Craft Advisory until 5 PM EDT Friday for Gulf of Mexico waters from Destin to the Suwannee River out to 60 NM. && $$ NEAR TERM...Fournier SHORT TERM...Harrigan LONG TERM...Lamers AVIATION...Fournier MARINE...Harrigan FIRE WEATHER...Fournier HYDROLOGY...Harrigan
AREA FORECAST DISCUSSION
NWS GAYLORD MI
935 AM EDT THU APR 4 2013 .SYNOPSIS... ISSUED AT 420 AM EDT THU APR 4 2013 A COLD FRONT WILL MOVE THROUGH NORTHERN MICHIGAN TODAY. PRECIPITATION ASSOCIATED WITH THIS FRONT WILL START AS SNOW THIS MORNING...BUT MIX WITH RAIN AS THE TEMPERATURES RISE ABOVE FREEZING TODAY. THE RAIN WILL END IN THE AFTERNOON AS DRIER TAKES OVER BEFORE THE FRONT MOVES THROUGH. HIGH PRESSURE AND COOLER TEMPERATURES WILL SETTLE IN FOR THURSDAY NIGHT AND FRIDAY BEFORE A STORM SYSTEM MOVES INTO NORTHERN MICHIGAN AND HANGS AROUND FOR MUCH OF THE WEEKEND...BRINGING RAIN AND SNOW MIXED FOR SATURDAY AND SUNDAY. && .UPDATE... ISSUED AT 933 AM EDT THU APR 4 2013 CURRENT RADAR AND SFC OBS SHOWING AREA OF PCPN OVER ERN UPPER AND STRAITS REGION...WHICH IS IN RESPONSE TO A COLD FRONT PUSHING INTO THE WRN LAKES. PCPN ASSOCIATED WITH THIS FRONT SO FAR THIS MORNING HAS BEEN CONFINED TO A NARROW BAND...HINDERED GREATLY BY LIMITED MSTR. SFC DEW PTS SOUTH OF THE STRAITS ARE CURRENTLY IN THE TEENS...THOUGH DEW PTS HAVE INCREASED INTO THE LOWER AND MID 20 OVER ERN UPPER JUST IN ADVANCE OF THE FRONT. AS FOR THE REST OF TODAY...LIMITED MSTR WILL REMAIN A HINDRANCE THROUGH THE AFTERNOON OVR NRN LWR MI...KEEPING ANY PCPN CONFINED TO A NARROW AREA RIGHT ALONG THE FRONT. MODEL SOUNDINGS SHOW PCPN CHCS ENDING FROM GLR NORTH BTWN 18Z AND 21Z...AND ENDING NEAR SAGINAW BAY REGION BETWEEN 00Z AND 03Z. OVERALL CURRENT FCST IN LINE WITH MILD TEMP AND SUN EARLY OVER THE SRN CWA...WITH PCPN ENDING OVER ERN UPPER EARLY THIS AFTN. UPDATE ISSUED AT 607 AM EDT THU APR 4 2013 CHANGES THIS HOUR: HAVE CONTINUED SLOWING TREND OF POPS THROUGH MUCH OF TODAY GIVEN RECENT GOOD AGREEMENT BETWEEN THE NAM/RAP/HRRR GIVEN VERY IMPRESSIVE PERFORMANCE FROM THE RAP OVER THE PAST FEW HOURS. SNOWFALL HAS ARRIVED FROM SAW-ERY-ANJ AND WILL GO AHEAD AND BUMP UP NEAR TERM POPS TO CATEGORICAL FOR NORTHERN CHIPPEWA THROUGH DAYBREAK. BEYOND THIS...INITIAL SURGE OF ISENTROPIC ASCENT ALONG LLEVEL MOISTURE AXIS WILL SHIFT EAST AND WE/LL THEN AWAIT FURTHER DEVELOPMENT ALONG THE FRONTAL BOUNDARY ITSELF...WHICH IS NOW SLIDING SOUTHEAST THROUGH WESTERN UPPER. DON/T EXPECT THIS TO BE SUBSTANTIAL...AND AS PREVIOUSLY MENTIONED...EXPECT IT TO DWINDLE AS IT HEADS SOUTH...WITH RAIN GRADUALLY TAKING OVER AS THE PREDOMINATE PRECIPITATION TYPE. COULD SEE AN INCH OF MORNING ACCUMS FROM PARADISE TO ANJ /WEBCAMS SHOW A COATING ATTM/...SO WATCH OUT FOR SOME SLICK AM TRAVEL IN THESE SPOTS. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 420 AM EDT THU APR 4 2013 HIGH IMPACT WEATHER POTENTIAL: GALE FORCE WINDS OVER MUCH OF NORTHERN LAKE MICHIGAN THROUGH MID MORNING. WILL LIKELY HAVE SOME COASTAL WIND GUSTS ABOVE 30 MPH TODAY...OTHERWISE...NO HIGH IMPACT WEATHER EXPECTED. OVERVIEW: SURFACE MAP EARLY THIS MORNING REVEALS HIGH PRESSURE RESPONSIBLE FOR THE BEAUTIFUL /ALBEIT CHILLY/ AFTERNOON YESTERDAY HAVING PUSHED SOUTH AND EAST INTO THE OHIO VALLEY/MID ATLANTIC REGION...THIS HAS ALLOWED BROAD SOUTHWESTERLY FLOW TO DEVELOP BETWEEN THIS FEATURE AND RATHER IMPRESSIVE SURFACE LOW NOW TRAVELING FROM WEST TO EAST ACROSS NORTHERN ONTARIO. PRIMARY FEATURE OF NOTE THROUGH THE SHORT TERM PORTION OF THE FORECAST IS A COLD FRONT DRAPED TO THE SOUTH AND WEST OF THIS LOW...APPROACHING LAKE SUPERIOR AS OF THIS WRITING. STRENGTHENING SOUTHWESTERLY WINDS OVER NORTHERN MICHIGAN HAVE PRECLUDED STEEP TEMPERATURE FALLS OVERNIGHT WITH MOST LOCATIONS AT LEAST 10F WARMER THAN 24 HOURS AGO. LLEVEL MOISTURE HAS NOT RESPONDED IN TANDEM...WITH 00Z APX RAOB SHOWING A PALTRY 0.14" PWAT. CLOSER TO THE FRONT...HOWEVER...PRECIPITATION ECHOES HAVE BEEN BLOSSOMING OVER THE PAST COUPLE OF HOURS AS ROBUST LOW LEVEL JET AT H8 /50KTS+/ TRANSPORTS A PLUME OF 2/3" PWATS RAPIDLY EASTWARD. THROUGH DAYBREAK: WINDS CONTINUE TO RAMP UP FROM WEST TO EAST...WITH SLOWLY INCREASING MID AND UPPER LEVEL CLOUDINESS...PRIMARILY FROM THE STRAITS NORTH. TIMING AREA OF INCREASING RADAR ECHOES SUGGESTS PRECIPITATION COULD ARRIVE AS EARLY AS 5-6AM OVER EASTERN UPPER AS SOME SNOW SHOWERS. INTERESTING TO NOTE SURFACE DEWPOINT TREND OVER THE PAST FEW HOURS OVER NORTHERN LOWER...WITH VALUES PLUMMETING TO BELOW 10F AT TVC/CAD AND ROPPING EVERYWHERE AWAY FROM LAKE MICHIGAN. THIS SUGGESTS THE SLOWING TREND IN FRONTAL PRECIP ARRIVAL /SEEN IN RECENT RENDTIONS OF THE HRRR/RAP/ ARE LIKELY ON THE RIGHT TRACK. TODAY: COLD FRONT PUSHES THROUGH NORTHERN MICHIGAN TODAY...STARTING THE DAY OVER WESTERN UPPER AND REACHING MY SOUTHEASTERN ZONES BY EVENING. PRIMARY CONCERNS TODAY CENTER AROUND PRECIPITATION CHANCES AS THIS BOUNDARY MOVES THROUGH...AS WELL AS THE STRENGTH OF SOUTHWESTERLY WINDS AHEAD OF IT. TRAJECTORY ANALYSIS SHOWS LLEVEL SOURCE REGION FOR AIR OVER NORTHERN LOWER TODAY COMES FROM THE IOWA/ILLINOIS REGION 24 HOURS AGO...AN AREA FEATURING A DEARTH OF LLEVEL MOISTURE. SO...BOUNDARY WILL BE FIGHTING INCREASINGLY DRY ATMOSPHERE AS IT PUSHES SOUTH AND EAST WITH LLEVEL MOISTURE TONGUE THINNING. LLEVEL CONVERGENCE IS MODEST...BUT WILL HAVE SOME HELP FROM AN ARRIVING JET MAX /AND ITS ASSOCIATED RIGHT ENTRANCE REGION/ AS WELL AS CONTINUED ISENTROPIC ASCENT. NET RESULT: EXPECT A BROKEN LINE OF SHOWERS TO SINK SOUTH DURING THE DAY...WEAKENING AS THEY DO SO. RECENT MODEL TRENDS HAVE CONTINUED TO SLOW THE SOUTHWARD MOVEMENT OF ANY PRECIPITATION... AND WHILE THIS FORECAST REPRESENTS A SLOWING TREND...IT COULD REQUIRE FURTHER SLOWING WITH PRECIITATION POTENTIALLY COMPLETELY FALLING APART BEFORE MAKING IT MUCH SOUTH OF M-32. PTYPE: STARTS THE DAY ALL SNOW...BUT RAPIDLY WARMING SURFACE LAYER SUGGESTS PREDOMINATE TYPE TO SWITCH TO RAIN COASTAL LOCALES BY LATE MORNING AND ALL AREAS BY AFTERNOON. ONLY CAVEAT TO THIS WILL BE OVER THE INTERIOR HIGH SPOTS WHERE WET BULBS IN THE MID 30S INDICATE A FEW SNOWFLAKES MIGHT MIX IN AT ANY TIME...ESP IF PRECIPITATION RATES ARE DECENT. OVERALL VERY LITTLE IMPACT EXPECTED...HOWEVER... OUTSIDE OF A FEW SLICK SPOTS TO START THE DAY FROM THE BRIDGE NORTH. PAVEMENT TEMPS WILL BE TOO WARM TO SUPPORT ANY ICING BY MID MORNING OVER NORTHERN LOWER. WINDS: PRETTY MUCH FULLY FORCED BY THE STRENGTH OF THE LOW LEVEL JET /40-50KTS AT H9 EARLY...WEAKENING AS IT HEADS SOUTH/ AND THE AMOUNT OF MIXING WE CAN DEVELOP AHEAD OF THE BOUNDARY. GIVEN A SOMEWHAT SLOWER ARRIVAL TO THE BOUNDARY...MIXING HEIGHTS SHOULD GET A CHANCE TO BUILD EARLY...WITH MOMENTUM TRANSPORT SUGGESTING WE CAN LIKELY TAP 30KTS. SO...EXPECT SOUTHWEST WINDS 15-25 MPH WITH GUSTS OVER 30 MPH BY LATE MORNING AND THROUGH THE AFTERNOON OVER NORTHERN LOWER...A LITTLE WEAKER THAN THIS FURTHER NORTH. TEMPS: T9 ROCKETS TO JUST ABOVE FREEZING AHEAD OF THE BOUNDARY... WITH THE POTENTIAL TO PRODUCE LOW-MID 50S AHEAD OF THE BOUNDARY. COMPLICATING THIS WILL BE CLOUDS AND PRECIP...WHICH...WITH PRETTY SUBSTANTIAL LLEVEL DEWPOINT DEPRESSIONS SUGGESTS AMPLE OPPORTUNITY FOR EVAPORATIONAL COOLING. WILL ALLOW SOUTHEASTERN ZONES TO MAKE A RUN AT 55...WITH LOCALES NORTH OF THIS GENERALLY IN THE MID-UPPER 40S. TONIGHT: NORTHWEST WINDS WILL USHER COLDER AIR INTO THE REGION AS HIGH PRESSURE BUILDS IN FROM THE NORTHERN PLAINS. T8 FALLS TO -12C SOUTH/-15C NORTH AFTER MIDNIGHT...WHICH WITH A MINOR AMOUNT OF RESIDUAL 850-700MB MOISTURE SUGGESTS THAT SOME LAKE RESPONSE MAY TRY AND GET GOING...BUT NOT UNTIL THE VERY END OF THIS PERIOD. WILL CARRY CHANCE POPS AFTER 09Z BUT NO SIGNIFICANT SNOWFALL EXPECTED. TEMPERATURES LOOK TO FALL INTO THE MID 20S AS COLD AIR ADVECTION IS OFFSET SOMEWHAT BY RESIDUAL WINDS AND SOME LAKE CLOUDINESS /NORTH/. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 420 AM EDT THU APR 4 2013 FRIDAY...INITIALLY, THERE WILL BE SOME LIGHT SNOW AND FLURRIES IN E UPPER, MAINLY NEAR WHITEFISH POINT AS THE 850 MB TEMPERATURES FALL TO AROUND -14C WITH ABOUT 50% RH IN THE 850-700 MB LAYER. THIS WILL BE MAINLY IN THE MORNING, BECAUSE AS THE HIGH PRESSURE BUILDS INTO THE REGION MORE DRY AIR PUSHES INTO THE FORECAST AREA, AND THE 850 MB TEMPERATURES RISE ABOVE -12C BY 18Z. SO WILL GO WITH A DRY DAY OVERALL. FRIDAY NIGHT...THE WARM ADVECTION WING FROM THE NEXT SYSTEM BEGINS TO MOVE INTO THE REGION, ESPECIALLY AFTER 06Z. THIS WILL BRING A CHANCE OF SNOW BY 12Z IN THE WESTERN PART OF THE FORECAST AREA. THE LOWER LEVEL MOISTURE WILL BE THE MAIN CONCERN AS THE POPS ARE DRAWN ROUGHLY WHERE THE 850 MB MOISTURE IS ABOVE 50%. HOWEVER, THIS COULD JUST AS EASILY BE NOTHING UNTIL THE DAY ON SATURDAY, IF THE ATMOSPHERE DOESN`T SATURATE FAST ENOUGH. SATURDAY...THE WARM FRONT MOVES NORTH A BIT, BUT FOR THE MOISTURE PART ONCE IT GETS TO AROUND THE STRAITS, IT LOOKS LIKE IT TRAVELS EAST, WITH THE SFC LOW FOLLOWING ALONG IT. THIS SETS UP SNOW IN E UPPER, WHICH COULD HAVE LIGHT TO MODERATE AMOUNTS THROUGH THE DAY. WOULD EXPECT A MIX, ESPECIALLY BETWEEN M-32 AND THE STRAITS AS THE PROFILES ARE EITHER ON THE 0C LINE. SOUTH OF M-32, THINK THAT IT WILL BE MAINLY RAIN. OVERNIGHT, THE WARMER AIR WITH BOTH MODELS, GETS TO THE STRAITS, THE RAIN WILL LIKELY GET ALL THE WAY TO THE STRAITS, AND WE`LL GET A MIX IN E UPPER. THE CONCERN, BASED ON THE PROFILES OF BOTH MODELS, IS THAT WE WILL PARTIALLY MELT SOME OF THE SNOW (TEMPERATURES IN THE PROFILE GET TO +2C AROUND 850 MB THEN FALL TO OR BELOW 0C IN E UPPER). SO WILL GO WITH SNOW/RAIN OR FREEZING RAIN MIX AT THIS POINT, AND KEEP IT MENTIONED IN HWOAPX. THE COLD AIR MOVES INTO E UPPER AGAIN ONCE THE LOW MOVES EAST. SO E UPPER WILL SEE A CHANGE OVER AGAIN BETWEEN 06Z AND 12Z. EXTENDED (SUNDAY THROUGH WEDNESDAY)...SUNDAY, THE MODELS MOVE THE LOW EAST OF THE REGION AND THE COLD AIR MOVES BACK. HOWEVER, THINGS ARE DRY ENOUGH AND WARM ENOUGH, THAT LITTLE IF NO PRECIPITATION WILL FALL. MONDAY, LOOKS LIKE ANOTHER WAVE FORMS ON THE FRONT THAT STALLS IT, AND EVEN ALLOWS FOR SOME WARMING. SO WILL GO WITH CHANCE OF RAIN IN N LOWER AND A MIX IN E UPPER. TUESDAY, THE LOW NO LONGER MOVES OUT OF THE MID MISSISSIPPI VALLEY AS THE MODELS FOCUS DEVELOPMENT ON THE CLOSED 500 MB LOW IN THE SOUTHWEST STATES. THIS WOULD KEEP THE SFC LOW IN TX/OK REGION WITH A WARM FRONT/SFC TROUGH THAT IS STALLED IN THE OHIO VALLEY. OVERNIGHT, THE GFS BEGINS TO LIFT THE 500 MB LOW INTO THE NORTHERN BRANCH. THE ECMWF LOOKS BETTER WITH THE SLOWER LIFTING OF THE WAVE KEEPING THE RAIN AND THE WARM FRONT ALONG OR SOUTH OF THE OHIO VALLEY. WEDNESDAY, THINKING THAT THE GFS IS TOO WET, DUE TO THE PHASING OF THE SYSTEMS. WOULD BE MORE INCLINED TO GO WITH THE ECMWF IDEA WITH THE HIGH SETTLING IN OVER THE GREAT LAKES. WHICH WOULD KEEP US DRY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 640 AM EDT THU APR 4 2013 SUMMARY: A MOISTURE-STARVED COLD FRONT WILL DROP THROUGH THE STATE TODAY...BRINGING A LINE OF RAIN AND SNOW SHOWERS. HIGH PRESSURE WILL BUILD IN BEHIND THIS FRONT TONIGHT...WITH SOME LAKE INDUCED CLOUDINESS DEVELOPING. RESTRICTIONS: EXPECT APN/TVC/MBL TO REMAIN VFR THROUGH THE UPCOMING TAF PERIOD...WITH A BRIEF PERIOD OF MVFR STILL EXPECTED THIS AFTERNOON /ALBEIT SOMEWHAT LATER THAN PREVIOUSLY EXPECTED/ AT PLN. EXPECT SHRASN TO IMPACT THIS SITE WITH MVFR CIGS DEVELOPING AFTER 21Z IMMEDIATELY BEHIND THE DEPARTING COLD FRONT. THESE CLOUDS WILL LIFT DURING THE EVENING WITH VFR CLOUDINESS /4KFT/ OVERNIGHT. WINDS: SOUTHWEST WINDS WILL STRENGTHEN TO 15G25KTS FOR THE BY MID MORNING AND CONTINUE THROUGH THE AFTERNOON WHILE GRADUALLY VEERING WEST. LATE THIS AFTERNOON WILL SHIFT NORTHWESTERLY AND DIMINISH TO AROUND 10KTS THIS EVENING AND OVERNIGHT. LLWS: SOUTHWEST WINDS AT 1.5-2KFT STILL REACHING AROUND 40 KTS AND GIVEN THAT THE TERMINALS REMAIN SOMEWHAT DECOUPLED FROM THIS STRONGER FLOW ALOFT...WILL LEAVE LLWS MENTION IN THROUGH 14Z BEFORE DAYTIME MIXING ELIMINATES ANY POTENTIAL SHEAR LAYERS. && .MARINE... ISSUED AT 420 AM EDT THU APR 4 2013 SUMMARY: A COLD FRONT WILL PUSH THROUGH NORTHERN MICHIGAN TODAY WITH GUSTY SOUTHWEST WINDS AHEAD OF IT SHIFTING NORTHWESTERLY BEHIND IT THIS EVENING AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES REGION. HIGH PRESSURE WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH FRIDAY NIGHT. HEADLINES: GALE WARNING THROUGH LATE MORNING STILL LOOKS GOOD OVER PORTIONS OF NORTHERN LAKE MICHIGAN. ELSEWHERE...WILL EXPAND SMALL CRAFTS TO ALL ZONES FOR TODAY GIVEN ROBUST WIND FIELD AHEAD OF APPROACHING COLD FRONT. MARGINAL SMALL CRAFT CONDITIONS CONTINUE THROUGH TONIGHT BEFORE A BREAK IN WIND/WAVE ACTIVITY IS EXPECTED FRIDAY. NEXT STORM SYSTEM ARRIVES SATURDAY WITH A RENEWED PERIOD OF SMALL CRAFTS LIKELY THROUGHOUT THE NEARSHORE WATERS OF NORTHERN MICHIGAN. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LHZ345>349. LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ323- 345-346. GALE WARNING UNTIL 11 AM EDT THIS MORNING FOR LMZ341-342-344. LS...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ321- 322. && $$ UPDATE...SR SYNOPSIS...JL SHORT TERM...ARNOTT LONG TERM...JL AVIATION...ARNOTT MARINE...ARNOTT
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
642 AM EDT THU APR 4 2013 .SYNOPSIS... ISSUED AT 420 AM EDT THU APR 4 2013 A COLD FRONT WILL MOVE THROUGH NORTHERN MICHIGAN TODAY. PRECIPITATION ASSOCIATED WITH THIS FRONT WILL START AS SNOW THIS MORNING...BUT MIX WITH RAIN AS THE TEMPERATURES RISE ABOVE FREEZING TODAY. THE RAIN WILL END IN THE AFTERNOON AS DRIER TAKES OVER BEFORE THE FRONT MOVES THROUGH. HIGH PRESSURE AND COOLER TEMPERATURES WILL SETTLE IN FOR THURSDAY NIGHT AND FRIDAY BEFORE A STORM SYSTEM MOVES INTO NORTHERN MICHIGAN AND HANGS AROUND FOR MUCH OF THE WEEKEND...BRINGING RAIN AND SNOW MIXED FOR SATURDAY AND SUNDAY. && .UPDATE... ISSUED AT 607 AM EDT THU APR 4 2013 CHANGES THIS HOUR: HAVE CONTINUED SLOWING TREND OF POPS THROUGH MUCH OF TODAY GIVEN RECENT GOOD AGREEMENT BETWEEN THE NAM/RAP/HRRR GIVEN VERY IMPRESSIVE PERFORMANCE FROM THE RAP OVER THE PAST FEW HOURS. SNOWFALL HAS ARRIVED FROM SAW-ERY-ANJ AND WILL GO AHEAD AND BUMP UP NEAR TERM POPS TO CATEGORICAL FOR NORTHERN CHIPPEWA THROUGH DAYBREAK. BEYOND THIS...INITIAL SURGE OF ISENTROPIC ASCENT ALONG LLEVEL MOISTURE AXIS WILL SHIFT EAST AND WE/LL THEN AWAIT FURTHER DEVELOPMENT ALONG THE FRONTAL BOUNDARY ITSELF...WHICH IS NOW SLIDING SOUTHEAST THROUGH WESTERN UPPER. DON/T EXPECT THIS TO BE SUBSTANTIAL...AND AS PREVIOUSLY MENTIONED...EXPECT IT TO DWINDLE AS IT HEADS SOUTH...WITH RAIN GRADUALLY TAKING OVER AS THE PREDOMINATE PRECIPITATION TYPE. COULD SEE AN INCH OF MORNING ACCUMS FROM PARADISE TO ANJ /WEBCAMS SHOW A COATING ATTM/...SO WATCH OUT FOR SOME SLICK AM TRAVEL IN THESE SPOTS. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 420 AM EDT THU APR 4 2013 HIGH IMPACT WEATHER POTENTIAL: GALE FORCE WINDS OVER MUCH OF NORTHERN LAKE MICHIGAN THROUGH MID MORNING. WILL LIKELY HAVE SOME COASTAL WIND GUSTS ABOVE 30 MPH TODAY...OTHERWISE...NO HIGH IMPACT WEATHER EXPECTED. OVERVIEW: SURFACE MAP EARLY THIS MORNING REVEALS HIGH PRESSURE RESPONSIBLE FOR THE BEAUTIFUL /ALBEIT CHILLY/ AFTERNOON YESTERDAY HAVING PUSHED SOUTH AND EAST INTO THE OHIO VALLEY/MID ATLANTIC REGION...THIS HAS ALLOWED BROAD SOUTHWESTERLY FLOW TO DEVELOP BETWEEN THIS FEATURE AND RATHER IMPRESSIVE SURFACE LOW NOW TRAVELING FROM WEST TO EAST ACROSS NORTHERN ONTARIO. PRIMARY FEATURE OF NOTE THROUGH THE SHORT TERM PORTION OF THE FORECAST IS A COLD FRONT DRAPED TO THE SOUTH AND WEST OF THIS LOW...APPROACHING LAKE SUPERIOR AS OF THIS WRITING. STRENGTHENING SOUTHWESTERLY WINDS OVER NORTHERN MICHIGAN HAVE PRECLUDED STEEP TEMPERATURE FALLS OVERNIGHT WITH MOST LOCATIONS AT LEAST 10F WARMER THAN 24 HOURS AGO. LLEVEL MOISTURE HAS NOT RESPONDED IN TANDEM...WITH 00Z APX RAOB SHOWING A PALTRY 0.14" PWAT. CLOSER TO THE FRONT...HOWEVER...PRECIPITATION ECHOES HAVE BEEN BLOSSOMING OVER THE PAST COUPLE OF HOURS AS ROBUST LOW LEVEL JET AT H8 /50KTS+/ TRANSPORTS A PLUME OF 2/3" PWATS RAPIDLY EASTWARD. THROUGH DAYBREAK: WINDS CONTINUE TO RAMP UP FROM WEST TO EAST...WITH SLOWLY INCREASING MID AND UPPER LEVEL CLOUDINESS...PRIMARILY FROM THE STRAITS NORTH. TIMING AREA OF INCREASING RADAR ECHOES SUGGESTS PRECIPITATION COULD ARRIVE AS EARLY AS 5-6AM OVER EASTERN UPPER AS SOME SNOW SHOWERS. INTERESTING TO NOTE SURFACE DEWPOINT TREND OVER THE PAST FEW HOURS OVER NORTHERN LOWER...WITH VALUES PLUMMETING TO BELOW 10F AT TVC/CAD AND ROPPING EVERYWHERE AWAY FROM LAKE MICHIGAN. THIS SUGGESTS THE SLOWING TREND IN FRONTAL PRECIP ARRIVAL /SEEN IN RECENT RENDTIONS OF THE HRRR/RAP/ ARE LIKELY ON THE RIGHT TRACK. TODAY: COLD FRONT PUSHES THROUGH NORTHERN MICHIGAN TODAY...STARTING THE DAY OVER WESTERN UPPER AND REACHING MY SOUTHEASTERN ZONES BY EVENING. PRIMARY CONCERNS TODAY CENTER AROUND PRECIPITATION CHANCES AS THIS BOUNDARY MOVES THROUGH...AS WELL AS THE STRENGTH OF SOUTHWESTERLY WINDS AHEAD OF IT. TRAJECTORY ANALYSIS SHOWS LLEVEL SOURCE REGION FOR AIR OVER NORTHERN LOWER TODAY COMES FROM THE IOWA/ILLINOIS REGION 24 HOURS AGO...AN AREA FEATURING A DEARTH OF LLEVEL MOISTURE. SO...BOUNDARY WILL BE FIGHTING INCREASINGLY DRY ATMOSPHERE AS IT PUSHES SOUTH AND EAST WITH LLEVEL MOISTURE TONGUE THINNING. LLEVEL CONVERGENCE IS MODEST...BUT WILL HAVE SOME HELP FROM AN ARRIVING JET MAX /AND ITS ASSOCIATED RIGHT ENTRANCE REGION/ AS WELL AS CONTINUED ISENTROPIC ASCENT. NET RESULT: EXPECT A BROKEN LINE OF SHOWERS TO SINK SOUTH DURING THE DAY...WEAKENING AS THEY DO SO. RECENT MODEL TRENDS HAVE CONTINUED TO SLOW THE SOUTHWARD MOVEMENT OF ANY PRECIPITATION... AND WHILE THIS FORECAST REPRESENTS A SLOWING TREND...IT COULD REQUIRE FURTHER SLOWING WITH PRECIITATION POTENTIALLY COMPLETELY FALLING APART BEFORE MAKING IT MUCH SOUTH OF M-32. PTYPE: STARTS THE DAY ALL SNOW...BUT RAPIDLY WARMING SURFACE LAYER SUGGESTS PREDOMINATE TYPE TO SWITCH TO RAIN COASTAL LOCALES BY LATE MORNING AND ALL AREAS BY AFTERNOON. ONLY CAVEAT TO THIS WILL BE OVER THE INTERIOR HIGH SPOTS WHERE WET BULBS IN THE MID 30S INDICATE A FEW SNOWFLAKES MIGHT MIX IN AT ANY TIME...ESP IF PRECIPITATION RATES ARE DECENT. OVERALL VERY LITTLE IMPACT EXPECTED...HOWEVER... OUTSIDE OF A FEW SLICK SPOTS TO START THE DAY FROM THE BRIDGE NORTH. PAVEMENT TEMPS WILL BE TOO WARM TO SUPPORT ANY ICING BY MID MORNING OVER NORTHERN LOWER. WINDS: PRETTY MUCH FULLY FORCED BY THE STRENGTH OF THE LOW LEVEL JET /40-50KTS AT H9 EARLY...WEAKENING AS IT HEADS SOUTH/ AND THE AMOUNT OF MIXING WE CAN DEVELOP AHEAD OF THE BOUNDARY. GIVEN A SOMEWHAT SLOWER ARRIVAL TO THE BOUNDARY...MIXING HEIGHTS SHOULD GET A CHANCE TO BUILD EARLY...WITH MOMENTUM TRANSPORT SUGGESTING WE CAN LIKELY TAP 30KTS. SO...EXPECT SOUTHWEST WINDS 15-25 MPH WITH GUSTS OVER 30 MPH BY LATE MORNING AND THROUGH THE AFTERNOON OVER NORTHERN LOWER...A LITTLE WEAKER THAN THIS FURTHER NORTH. TEMPS: T9 ROCKETS TO JUST ABOVE FREEZING AHEAD OF THE BOUNDARY... WITH THE POTENTIAL TO PRODUCE LOW-MID 50S AHEAD OF THE BOUNDARY. COMPLICATING THIS WILL BE CLOUDS AND PRECIP...WHICH...WITH PRETTY SUBSTANTIAL LLEVEL DEWPOINT DEPRESSIONS SUGGESTS AMPLE OPPORTUNITY FOR EVAPORATIONAL COOLING. WILL ALLOW SOUTHEASTERN ZONES TO MAKE A RUN AT 55...WITH LOCALES NORTH OF THIS GENERALLY IN THE MID-UPPER 40S. TONIGHT: NORTHWEST WINDS WILL USHER COLDER AIR INTO THE REGION AS HIGH PRESSURE BUILDS IN FROM THE NORTHERN PLAINS. T8 FALLS TO -12C SOUTH/-15C NORTH AFTER MIDNIGHT...WHICH WITH A MINOR AMOUNT OF RESIDUAL 850-700MB MOISTURE SUGGESTS THAT SOME LAKE RESPONSE MAY TRY AND GET GOING...BUT NOT UNTIL THE VERY END OF THIS PERIOD. WILL CARRY CHANCE POPS AFTER 09Z BUT NO SIGNIFICANT SNOWFALL EXPECTED. TEMPERATURES LOOK TO FALL INTO THE MID 20S AS COLD AIR ADVECTION IS OFFSET SOMEWHAT BY RESIDUAL WINDS AND SOME LAKE CLOUDINESS /NORTH/. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 420 AM EDT THU APR 4 2013 FRIDAY...INITIALLY, THERE WILL BE SOME LIGHT SNOW AND FLURRIES IN E UPPER, MAINLY NEAR WHITEFISH POINT AS THE 850 MB TEMPERATURES FALL TO AROUND -14C WITH ABOUT 50% RH IN THE 850-700 MB LAYER. THIS WILL BE MAINLY IN THE MORNING, BECAUSE AS THE HIGH PRESSURE BUILDS INTO THE REGION MORE DRY AIR PUSHES INTO THE FORECAST AREA, AND THE 850 MB TEMPERATURES RISE ABOVE -12C BY 18Z. SO WILL GO WITH A DRY DAY OVERALL. FRIDAY NIGHT...THE WARM ADVECTION WING FROM THE NEXT SYSTEM BEGINS TO MOVE INTO THE REGION, ESPECIALLY AFTER 06Z. THIS WILL BRING A CHANCE OF SNOW BY 12Z IN THE WESTERN PART OF THE FORECAST AREA. THE LOWER LEVEL MOISTURE WILL BE THE MAIN CONCERN AS THE POPS ARE DRAWN ROUGHLY WHERE THE 850 MB MOISTURE IS ABOVE 50%. HOWEVER, THIS COULD JUST AS EASILY BE NOTHING UNTIL THE DAY ON SATURDAY, IF THE ATMOSPHERE DOESN`T SATURATE FAST ENOUGH. SATURDAY...THE WARM FRONT MOVES NORTH A BIT, BUT FOR THE MOISTURE PART ONCE IT GETS TO AROUND THE STRAITS, IT LOOKS LIKE IT TRAVELS EAST, WITH THE SFC LOW FOLLOWING ALONG IT. THIS SETS UP SNOW IN E UPPER, WHICH COULD HAVE LIGHT TO MODERATE AMOUNTS THROUGH THE DAY. WOULD EXPECT A MIX, ESPECIALLY BETWEEN M-32 AND THE STRAITS AS THE PROFILES ARE EITHER ON THE 0C LINE. SOUTH OF M-32, THINK THAT IT WILL BE MAINLY RAIN. OVERNIGHT, THE WARMER AIR WITH BOTH MODELS, GETS TO THE STRAITS, THE RAIN WILL LIKELY GET ALL THE WAY TO THE STRAITS, AND WE`LL GET A MIX IN E UPPER. THE CONCERN, BASED ON THE PROFILES OF BOTH MODELS, IS THAT WE WILL PARTIALLY MELT SOME OF THE SNOW (TEMPERATURES IN THE PROFILE GET TO +2C AROUND 850 MB THEN FALL TO OR BELOW 0C IN E UPPER). SO WILL GO WITH SNOW/RAIN OR FREEZING RAIN MIX AT THIS POINT, AND KEEP IT MENTIONED IN HWOAPX. THE COLD AIR MOVES INTO E UPPER AGAIN ONCE THE LOW MOVES EAST. SO E UPPER WILL SEE A CHANGE OVER AGAIN BETWEEN 06Z AND 12Z. EXTENDED (SUNDAY THROUGH WEDNESDAY)...SUNDAY, THE MODELS MOVE THE LOW EAST OF THE REGION AND THE COLD AIR MOVES BACK. HOWEVER, THINGS ARE DRY ENOUGH AND WARM ENOUGH, THAT LITTLE IF NO PRECIPITATION WILL FALL. MONDAY, LOOKS LIKE ANOTHER WAVE FORMS ON THE FRONT THAT STALLS IT, AND EVEN ALLOWS FOR SOME WARMING. SO WILL GO WITH CHANCE OF RAIN IN N LOWER AND A MIX IN E UPPER. TUESDAY, THE LOW NO LONGER MOVES OUT OF THE MID MISSISSIPPI VALLEY AS THE MODELS FOCUS DEVELOPMENT ON THE CLOSED 500 MB LOW IN THE SOUTHWEST STATES. THIS WOULD KEEP THE SFC LOW IN TX/OK REGION WITH A WARM FRONT/SFC TROUGH THAT IS STALLED IN THE OHIO VALLEY. OVERNIGHT, THE GFS BEGINS TO LIFT THE 500 MB LOW INTO THE NORTHERN BRANCH. THE ECMWF LOOKS BETTER WITH THE SLOWER LIFTING OF THE WAVE KEEPING THE RAIN AND THE WARM FRONT ALONG OR SOUTH OF THE OHIO VALLEY. WEDNESDAY, THINKING THAT THE GFS IS TOO WET, DUE TO THE PHASING OF THE SYSTEMS. WOULD BE MORE INCLINED TO GO WITH THE ECMWF IDEA WITH THE HIGH SETTLING IN OVER THE GREAT LAKES. WHICH WOULD KEEP US DRY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 640 AM EDT THU APR 4 2013 SUMMARY: A MOISTURE-STARVED COLD FRONT WILL DROP THROUGH THE STATE TODAY...BRINGING A LINE OF RAIN AND SNOW SHOWERS. HIGH PRESSURE WILL BUILD IN BEHIND THIS FRONT TONIGHT...WITH SOME LAKE INDUCED CLOUDINESS DEVELOPING. RESTRICTIONS: EXPECT APN/TVC/MBL TO REMAIN VFR THROUGH THE UPCOMING TAF PERIOD...WITH A BRIEF PERIOD OF MVFR STILL EXPECTED THIS AFTERNOON /ALBEIT SOMEWHAT LATER THAN PREVIOUSLY EXPECTED/ AT PLN. EXPECT SHRASN TO IMPACT THIS SITE WITH MVFR CIGS DEVELOPING AFTER 21Z IMMEDIATELY BEHIND THE DEPARTING COLD FRONT. THESE CLOUDS WILL LIFT DURING THE EVENING WITH VFR CLOUDINESS /4KFT/ OVERNIGHT. WINDS: SOUTHWEST WINDS WILL STRENGTHEN TO 15G25KTS FOR THE BY MID MORNING AND CONTINUE THROUGH THE AFTERNOON WHILE GRADUALLY VEERING WEST. LATE THIS AFTERNOON WILL SHIFT NORTHWESTERLY AND DIMINISH TO AROUND 10KTS THIS EVENING AND OVERNIGHT. LLWS: SOUTHWEST WINDS AT 1.5-2KFT STILL REACHING AROUND 40 KTS AND GIVEN THAT THE TERMINALS REMAIN SOMEWHAT DECOUPLED FROM THIS STRONGER FLOW ALOFT...WILL LEAVE LLWS MENTION IN THROUGH 14Z BEFORE DAYTIME MIXING ELIMINATES ANY POTENTIAL SHEAR LAYERS. && .MARINE... ISSUED AT 420 AM EDT THU APR 4 2013 SUMMARY: A COLD FRONT WILL PUSH THROUGH NORTHERN MICHIGAN TODAY WITH GUSTY SOUTHWEST WINDS AHEAD OF IT SHIFTING NORTHWESTERLY BEHIND IT THIS EVENING AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES REGION. HIGH PRESSURE WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH FRIDAY NIGHT. HEADLINES: GALE WARNING THROUGH LATE MORNING STILL LOOKS GOOD OVER PORTIONS OF NORTHERN LAKE MICHIGAN. ELSEWHERE...WILL EXPAND SMALL CRAFTS TO ALL ZONES FOR TODAY GIVEN ROBUST WIND FIELD AHEAD OF APPROACHING COLD FRONT. MARGINAL SMALL CRAFT CONDITIONS CONTINUE THROUGH TONIGHT BEFORE A BREAK IN WIND/WAVE ACTIVITY IS EXPECTED FRIDAY. NEXT STORM SYSTEM ARRIVES SATURDAY WITH A RENEWED PERIOD OF SMALL CRAFTS LIKELY THROUGHOUT THE NEARSHORE WATERS OF NORTHERN MICHIGAN. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LHZ345>349. LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ323- 345-346. GALE WARNING UNTIL 11 AM EDT THIS MORNING FOR LMZ341-342-344. LS...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ321- 322. && $$ UPDATE...ARNOTT SYNOPSIS...JL SHORT TERM...ARNOTT LONG TERM...JL AVIATION...ARNOTT MARINE...ARNOTT
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
614 AM EDT THU APR 4 2013 .SYNOPSIS... ISSUED AT 420 AM EDT THU APR 4 2013 A COLD FRONT WILL MOVE THROUGH NORTHERN MICHIGAN TODAY. PRECIPITATION ASSOCIATED WITH THIS FRONT WILL START AS SNOW THIS MORNING...BUT MIX WITH RAIN AS THE TEMPERATURES RISE ABOVE FREEZING TODAY. THE RAIN WILL END IN THE AFTERNOON AS DRIER TAKES OVER BEFORE THE FRONT MOVES THROUGH. HIGH PRESSURE AND COOLER TEMPERATURES WILL SETTLE IN FOR THURSDAY NIGHT AND FRIDAY BEFORE A STORM SYSTEM MOVES INTO NORTHERN MICHIGAN AND HANGS AROUND FOR MUCH OF THE WEEKEND...BRINGING RAIN AND SNOW MIXED FOR SATURDAY AND SUNDAY. && .UPDATE... ISSUED AT 607 AM EDT THU APR 4 2013 CHANGES THIS HOUR: HAVE CONTINUED SLOWING TREND OF POPS THROUGH MUCH OF TODAY GIVEN RECENT GOOD AGREEMENT BETWEEN THE NAM/RAP/HRRR GIVEN VERY IMPRESSIVE PERFORMANCE FROM THE RAP OVER THE PAST FEW HOURS. SNOWFALL HAS ARRIVED FROM SAW-ERY-ANJ AND WILL GO AHEAD AND BUMP UP NEAR TERM POPS TO CATEGORICAL FOR NORTHERN CHIPPEWA THROUGH DAYBREAK. BEYOND THIS...INITIAL SURGE OF ISENTROPIC ASCENT ALONG LLEVEL MOISTURE AXIS WILL SHIFT EAST AND WE/LL THEN AWAIT FURTHER DEVELOPMENT ALONG THE FRONTAL BOUNDARY ITSELF...WHICH IS NOW SLIDING SOUTHEAST THROUGH WESTERN UPPER. DON/T EXPECT THIS TO BE SUBSTANTIAL...AND AS PREVIOUSLY MENTIONED...EXPECT IT TO DWINDLE AS IT HEADS SOUTH...WITH RAIN GRADUALLY TAKING OVER AS THE PREDOMINATE PRECIPITATION TYPE. COULD SEE AN INCH OF MORNING ACCUMS FROM PARADISE TO ANJ /WEBCAMS SHOW A COATING ATTM/...SO WATCH OUT FOR SOME SLICK AM TRAVEL IN THESE SPOTS. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 420 AM EDT THU APR 4 2013 HIGH IMPACT WEATHER POTENTIAL: GALE FORCE WINDS OVER MUCH OF NORTHERN LAKE MICHIGAN THROUGH MID MORNING. WILL LIKELY HAVE SOME COASTAL WIND GUSTS ABOVE 30 MPH TODAY...OTHERWISE...NO HIGH IMPACT WEATHER EXPECTED. OVERVIEW: SURFACE MAP EARLY THIS MORNING REVEALS HIGH PRESSURE RESPONSIBLE FOR THE BEAUTIFUL /ALBEIT CHILLY/ AFTERNOON YESTERDAY HAVING PUSHED SOUTH AND EAST INTO THE OHIO VALLEY/MID ATLANTIC REGION...THIS HAS ALLOWED BROAD SOUTHWESTERLY FLOW TO DEVELOP BETWEEN THIS FEATURE AND RATHER IMPRESSIVE SURFACE LOW NOW TRAVELING FROM WEST TO EAST ACROSS NORTHERN ONTARIO. PRIMARY FEATURE OF NOTE THROUGH THE SHORT TERM PORTION OF THE FORECAST IS A COLD FRONT DRAPED TO THE SOUTH AND WEST OF THIS LOW...APPROACHING LAKE SUPERIOR AS OF THIS WRITING. STRENGTHENING SOUTHWESTERLY WINDS OVER NORTHERN MICHIGAN HAVE PRECLUDED STEEP TEMPERATURE FALLS OVERNIGHT WITH MOST LOCATIONS AT LEAST 10F WARMER THAN 24 HOURS AGO. LLEVEL MOISTURE HAS NOT RESPONDED IN TANDEM...WITH 00Z APX RAOB SHOWING A PALTRY 0.14" PWAT. CLOSER TO THE FRONT...HOWEVER...PRECIPITATION ECHOES HAVE BEEN BLOSSOMING OVER THE PAST COUPLE OF HOURS AS ROBUST LOW LEVEL JET AT H8 /50KTS+/ TRANSPORTS A PLUME OF 2/3" PWATS RAPIDLY EASTWARD. THROUGH DAYBREAK: WINDS CONTINUE TO RAMP UP FROM WEST TO EAST...WITH SLOWLY INCREASING MID AND UPPER LEVEL CLOUDINESS...PRIMARILY FROM THE STRAITS NORTH. TIMING AREA OF INCREASING RADAR ECHOES SUGGESTS PRECIPITATION COULD ARRIVE AS EARLY AS 5-6AM OVER EASTERN UPPER AS SOME SNOW SHOWERS. INTERESTING TO NOTE SURFACE DEWPOINT TREND OVER THE PAST FEW HOURS OVER NORTHERN LOWER...WITH VALUES PLUMMETING TO BELOW 10F AT TVC/CAD AND ROPPING EVERYWHERE AWAY FROM LAKE MICHIGAN. THIS SUGGESTS THE SLOWING TREND IN FRONTAL PRECIP ARRIVAL /SEEN IN RECENT RENDTIONS OF THE HRRR/RAP/ ARE LIKELY ON THE RIGHT TRACK. TODAY: COLD FRONT PUSHES THROUGH NORTHERN MICHIGAN TODAY...STARTING THE DAY OVER WESTERN UPPER AND REACHING MY SOUTHEASTERN ZONES BY EVENING. PRIMARY CONCERNS TODAY CENTER AROUND PRECIPITATION CHANCES AS THIS BOUNDARY MOVES THROUGH...AS WELL AS THE STRENGTH OF SOUTHWESTERLY WINDS AHEAD OF IT. TRAJECTORY ANALYSIS SHOWS LLEVEL SOURCE REGION FOR AIR OVER NORTHERN LOWER TODAY COMES FROM THE IOWA/ILLINOIS REGION 24 HOURS AGO...AN AREA FEATURING A DEARTH OF LLEVEL MOISTURE. SO...BOUNDARY WILL BE FIGHTING INCREASINGLY DRY ATMOSPHERE AS IT PUSHES SOUTH AND EAST WITH LLEVEL MOISTURE TONGUE THINNING. LLEVEL CONVERGENCE IS MODEST...BUT WILL HAVE SOME HELP FROM AN ARRIVING JET MAX /AND ITS ASSOCIATED RIGHT ENTRANCE REGION/ AS WELL AS CONTINUED ISENTROPIC ASCENT. NET RESULT: EXPECT A BROKEN LINE OF SHOWERS TO SINK SOUTH DURING THE DAY...WEAKENING AS THEY DO SO. RECENT MODEL TRENDS HAVE CONTINUED TO SLOW THE SOUTHWARD MOVEMENT OF ANY PRECIPITATION... AND WHILE THIS FORECAST REPRESENTS A SLOWING TREND...IT COULD REQUIRE FURTHER SLOWING WITH PRECIITATION POTENTIALLY COMPLETELY FALLING APART BEFORE MAKING IT MUCH SOUTH OF M-32. PTYPE: STARTS THE DAY ALL SNOW...BUT RAPIDLY WARMING SURFACE LAYER SUGGESTS PREDOMINATE TYPE TO SWITCH TO RAIN COASTAL LOCALES BY LATE MORNING AND ALL AREAS BY AFTERNOON. ONLY CAVEAT TO THIS WILL BE OVER THE INTERIOR HIGH SPOTS WHERE WET BULBS IN THE MID 30S INDICATE A FEW SNOWFLAKES MIGHT MIX IN AT ANY TIME...ESP IF PRECIPITATION RATES ARE DECENT. OVERALL VERY LITTLE IMPACT EXPECTED...HOWEVER... OUTSIDE OF A FEW SLICK SPOTS TO START THE DAY FROM THE BRIDGE NORTH. PAVEMENT TEMPS WILL BE TOO WARM TO SUPPORT ANY ICING BY MID MORNING OVER NORTHERN LOWER. WINDS: PRETTY MUCH FULLY FORCED BY THE STRENGTH OF THE LOW LEVEL JET /40-50KTS AT H9 EARLY...WEAKENING AS IT HEADS SOUTH/ AND THE AMOUNT OF MIXING WE CAN DEVELOP AHEAD OF THE BOUNDARY. GIVEN A SOMEWHAT SLOWER ARRIVAL TO THE BOUNDARY...MIXING HEIGHTS SHOULD GET A CHANCE TO BUILD EARLY...WITH MOMENTUM TRANSPORT SUGGESTING WE CAN LIKELY TAP 30KTS. SO...EXPECT SOUTHWEST WINDS 15-25 MPH WITH GUSTS OVER 30 MPH BY LATE MORNING AND THROUGH THE AFTERNOON OVER NORTHERN LOWER...A LITTLE WEAKER THAN THIS FURTHER NORTH. TEMPS: T9 ROCKETS TO JUST ABOVE FREEZING AHEAD OF THE BOUNDARY... WITH THE POTENTIAL TO PRODUCE LOW-MID 50S AHEAD OF THE BOUNDARY. COMPLICATING THIS WILL BE CLOUDS AND PRECIP...WHICH...WITH PRETTY SUBSTANTIAL LLEVEL DEWPOINT DEPRESSIONS SUGGESTS AMPLE OPPORTUNITY FOR EVAPORATIONAL COOLING. WILL ALLOW SOUTHEASTERN ZONES TO MAKE A RUN AT 55...WITH LOCALES NORTH OF THIS GENERALLY IN THE MID-UPPER 40S. TONIGHT: NORTHWEST WINDS WILL USHER COLDER AIR INTO THE REGION AS HIGH PRESSURE BUILDS IN FROM THE NORTHERN PLAINS. T8 FALLS TO -12C SOUTH/-15C NORTH AFTER MIDNIGHT...WHICH WITH A MINOR AMOUNT OF RESIDUAL 850-700MB MOISTURE SUGGESTS THAT SOME LAKE RESPONSE MAY TRY AND GET GOING...BUT NOT UNTIL THE VERY END OF THIS PERIOD. WILL CARRY CHANCE POPS AFTER 09Z BUT NO SIGNIFICANT SNOWFALL EXPECTED. TEMPERATURES LOOK TO FALL INTO THE MID 20S AS COLD AIR ADVECTION IS OFFSET SOMEWHAT BY RESIDUAL WINDS AND SOME LAKE CLOUDINESS /NORTH/. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 420 AM EDT THU APR 4 2013 FRIDAY...INITIALLY, THERE WILL BE SOME LIGHT SNOW AND FLURRIES IN E UPPER, MAINLY NEAR WHITEFISH POINT AS THE 850 MB TEMPERATURES FALL TO AROUND -14C WITH ABOUT 50% RH IN THE 850-700 MB LAYER. THIS WILL BE MAINLY IN THE MORNING, BECAUSE AS THE HIGH PRESSURE BUILDS INTO THE REGION MORE DRY AIR PUSHES INTO THE FORECAST AREA, AND THE 850 MB TEMPERATURES RISE ABOVE -12C BY 18Z. SO WILL GO WITH A DRY DAY OVERALL. FRIDAY NIGHT...THE WARM ADVECTION WING FROM THE NEXT SYSTEM BEGINS TO MOVE INTO THE REGION, ESPECIALLY AFTER 06Z. THIS WILL BRING A CHANCE OF SNOW BY 12Z IN THE WESTERN PART OF THE FORECAST AREA. THE LOWER LEVEL MOISTURE WILL BE THE MAIN CONCERN AS THE POPS ARE DRAWN ROUGHLY WHERE THE 850 MB MOISTURE IS ABOVE 50%. HOWEVER, THIS COULD JUST AS EASILY BE NOTHING UNTIL THE DAY ON SATURDAY, IF THE ATMOSPHERE DOESN`T SATURATE FAST ENOUGH. SATURDAY...THE WARM FRONT MOVES NORTH A BIT, BUT FOR THE MOISTURE PART ONCE IT GETS TO AROUND THE STRAITS, IT LOOKS LIKE IT TRAVELS EAST, WITH THE SFC LOW FOLLOWING ALONG IT. THIS SETS UP SNOW IN E UPPER, WHICH COULD HAVE LIGHT TO MODERATE AMOUNTS THROUGH THE DAY. WOULD EXPECT A MIX, ESPECIALLY BETWEEN M-32 AND THE STRAITS AS THE PROFILES ARE EITHER ON THE 0C LINE. SOUTH OF M-32, THINK THAT IT WILL BE MAINLY RAIN. OVERNIGHT, THE WARMER AIR WITH BOTH MODELS, GETS TO THE STRAITS, THE RAIN WILL LIKELY GET ALL THE WAY TO THE STRAITS, AND WE`LL GET A MIX IN E UPPER. THE CONCERN, BASED ON THE PROFILES OF BOTH MODELS, IS THAT WE WILL PARTIALLY MELT SOME OF THE SNOW (TEMPERATURES IN THE PROFILE GET TO +2C AROUND 850 MB THEN FALL TO OR BELOW 0C IN E UPPER). SO WILL GO WITH SNOW/RAIN OR FREEZING RAIN MIX AT THIS POINT, AND KEEP IT MENTIONED IN HWOAPX. THE COLD AIR MOVES INTO E UPPER AGAIN ONCE THE LOW MOVES EAST. SO E UPPER WILL SEE A CHANGE OVER AGAIN BETWEEN 06Z AND 12Z. EXTENDED (SUNDAY THROUGH WEDNESDAY)...SUNDAY, THE MODELS MOVE THE LOW EAST OF THE REGION AND THE COLD AIR MOVES BACK. HOWEVER, THINGS ARE DRY ENOUGH AND WARM ENOUGH, THAT LITTLE IF NO PRECIPITATION WILL FALL. MONDAY, LOOKS LIKE ANOTHER WAVE FORMS ON THE FRONT THAT STALLS IT, AND EVEN ALLOWS FOR SOME WARMING. SO WILL GO WITH CHANCE OF RAIN IN N LOWER AND A MIX IN E UPPER. TUESDAY, THE LOW NO LONGER MOVES OUT OF THE MID MISSISSIPPI VALLEY AS THE MODELS FOCUS DEVELOPMENT ON THE CLOSED 500 MB LOW IN THE SOUTHWEST STATES. THIS WOULD KEEP THE SFC LOW IN TX/OK REGION WITH A WARM FRONT/SFC TROUGH THAT IS STALLED IN THE OHIO VALLEY. OVERNIGHT, THE GFS BEGINS TO LIFT THE 500 MB LOW INTO THE NORTHERN BRANCH. THE ECMWF LOOKS BETTER WITH THE SLOWER LIFTING OF THE WAVE KEEPING THE RAIN AND THE WARM FRONT ALONG OR SOUTH OF THE OHIO VALLEY. WEDNESDAY, THINKING THAT THE GFS IS TOO WET, DUE TO THE PHASING OF THE SYSTEMS. WOULD BE MORE INCLINED TO GO WITH THE ECMWF IDEA WITH THE HIGH SETTLING IN OVER THE GREAT LAKES. WHICH WOULD KEEP US DRY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 132 AM EDT THU APR 4 2013 SUMMARY: A COLD FRONT WILL PUSH SOUTHEAST THROUGH THE GREAT LAKES REGION TODAY...BRINGING A BAND OF SCATTERED RAIN AND SNOW SHOWERS ALONG WITH GUSTY SOUTHWEST WINDS. SKIES WILL PARTIALLY CLEAR BEHIND THE FRONT THIS EVENING AS HIGH PRESSURE BUILDS TOWARDS THE GREAT LAKES FROM CENTRAL CANADA. RESTRICTIONS: REALLY NOT THAT EXCITED ABOUT RESTRICTION POTENTIAL WITH THIS BOUNDARY AS LLEVEL AIRMASS IS QUITE DRY. INHERITED TAFS INCLUDED PERIOD OF MVFR AT PLN AND THIS LOOKS LIKE A GOOD WAY TO GO WITH THE LLEVEL MOISTURE GRADUALLY ERODING AS THE BOUNDARY HEADS SOUTH. THUS...AT APN/TVC/MBL EXPECT A VFR TAF PERIOD WITH A CHANCE OF AN AFTERNOON RAIN SHOWER. AT PLN...CHANCES FOR A SHOWER /RAIN OR SNOW/ ARE MORE LIKELY AND WILL CONTINUE BRIEF PERIOD OF MVFR. VFR CONDITIONS /RESIDUAL 4KFT CLOUD DECK/ TAKE OVER BEHIND THE FRONT THIS EVENING. WINDS: LIGHT WINDS WILL BECOME SOUTHWESTERLY 5-10KTS TOWARDS DAYBREAK BEFORE INCREASING MARKEDLY TO 15G25KTS FOR THE LATE MORNING/EARLY AFTERNOON. BEYOND THIS...WINDS WILL SHIFT NORTHWESTERLY AND DIMINISH TO AROUND 10KTS THIS EVENING. LLWS: IMPRESSIVE LOW LEVEL JET AHEAD OF ARRIVING FRONT WILL ALLOW FOR THE DEVELOPMENT OF LLWS LATER TONIGHT AT ALL SITES WITH 1.5KFT WINDS INCREASING TO 40 KTS FROM THE SOUTHWEST. WIND SHEAR WILL ABATE DURING THE MORNING HOURS AS MIXING COMMENCES. && .MARINE... ISSUED AT 420 AM EDT THU APR 4 2013 SUMMARY: A COLD FRONT WILL PUSH THROUGH NORTHERN MICHIGAN TODAY WITH GUSTY SOUTHWEST WINDS AHEAD OF IT SHIFTING NORTHWESTERLY BEHIND IT THIS EVENING AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES REGION. HIGH PRESSURE WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH FRIDAY NIGHT. HEADLINES: GALE WARNING THROUGH LATE MORNING STILL LOOKS GOOD OVER PORTIONS OF NORTHERN LAKE MICHIGAN. ELSEWHERE...WILL EXPAND SMALL CRAFTS TO ALL ZONES FOR TODAY GIVEN ROBUST WIND FIELD AHEAD OF APPROACHING COLD FRONT. MARGINAL SMALL CRAFT CONDITIONS CONTINUE THROUGH TONIGHT BEFORE A BREAK IN WIND/WAVE ACTIVITY IS EXPECTED FRIDAY. NEXT STORM SYSTEM ARRIVES SATURDAY WITH A RENEWED PERIOD OF SMALL CRAFTS LIKELY THROUGHOUT THE NEARSHORE WATERS OF NORTHERN MICHIGAN. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LHZ345>349. LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ323- 345-346. GALE WARNING UNTIL 11 AM EDT THIS MORNING FOR LMZ341-342-344. LS...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ321- 322. && $$ UPDATE...ARNOTT SYNOPSIS...JL SHORT TERM...ARNOTT LONG TERM...JL AVIATION...ARNOTT MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
620 AM EDT THU APR 4 2013 .SYNOPSIS... LOW PRESSURE PASSES SOUTH LATE TODAY AND TONIGHT WITH THE CHANCE FOR RAIN. MODERATING TEMPERATURES OVER THE WEEKEND. FRONT NEARBY SUNDAY INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 615 AM UPDATE... NO CHANGES ATTM. PREVIOUS DISCUSSION BELOW... MDLS COMING IN A BIT FASTER WITH ONSET OF PCPN LATER TDY AS SFC LOW ORGANIZES ALONG GA/SC COAST. HOWEVER VERY DRY LLVLS WILL BE BATTLING MOISTURE ADVECTION FROM S. AS SUCH DID NOT GO AS FAST AS MDLS SUGGEST ONCE INTO S WV PLATEAU. LATEST RAP MDL SEEMS TO HAVE A BETTER REFLECTION OF CURRENT THINKING AND USED IT AS A GUIDE THRU 00Z. DO BRING IN HIGH POPS ACROSS SW VA BY 18Z AND THEN SLOWLY SPREAD N UP THE EASTERN SLOPES TO INCLUDE MUCH OF POCAHONTAS CO WITH THE CATEGORICAL POPS. HAVE A SHARP GRADIENT HEADING W...WITH CHC POPS EXTENDING TO CRW- HTS AREA AND UP TOWARD CKB. FEEL SE OH AND NW LOWLAND CO STAY DRY. HAVE ARND A THIRD OF AN INCH QPF FOR SW VA AND UP THE EASTERN SLOPES. QUICKLY TAILS OF W OF I79 CORRIDOR. EXIT BULK OF PCPN BY 06Z TO THE E...WITH LINGERING CHC POPS FOR S/W TROF AXIS SLIDING THRU. THERE IS SOME CONCERN FOR WINTRY PCPN AT THE ONSET ACROSS RIDGES IN POCAHONTAS CO. MDLS INDICATE GOOD WET BULBING ARND 00Z TO REFLECT SOME WET SN OR MIX POTENTIAL BEFORE SWITCHING TO RA LATER IN EVE. USED SFC AND MODEL ALOFT TOO TO REFLECT THIS IN WX GRIDS. WILL KEEP ACCUMULATIONS OUT OF GRIDS FOR NOW THOUGH. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... MODELS IN GOOD AGREEMENT SHOWING SYSTEM PULLING OFF TO THE EAST EARLY FRIDAY...WITH DRY WEATHER EXPECTED BY MIDDAY. WILL SPEED UP THE EXODUS OF THE POPS. MOS GUIDANCE FOR HIGHS ON FRIDAY HAS BEEN TRENDING DOWNWARD...BUT STILL LOOKS TOO HIGH. HAVE UNDERCUT MOS ONCE AGAIN FOR HIGHS FRIDAY...AND ALSO ON SATURDAY. A COLD FRONT THEN PUSHES INTO THE AREA ON SUNDAY...BEFORE STALLING OVER THE AREA. SOME DEBATE AMONG THE MODELS ON WHERE THE FRONT WILL STALL. CURRENT FORECAST LOOKS LIKE A GOOD COMPROMISE FOR NOW...SO DID NOT CHANGE WITH THE EXCEPTION OF SLOWING THE ARRIVAL OF THE SHOWERS. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... WAVY FRONT APPROACHES THIS WEEKEND AND THEN HANGS NEARBY THE BALANCE OF THE PERIOD. RIDGING ADVERTISED FOR EARLY NEXT WEEK OVER THE PAST FEW DAYS IS ALL BUT GONE...THE GFS STILL AMPLIFYING ONE BUT ALONG THE E COAST TUE. THAT IS WHEN THE ECMWF IS MARKEDLY DIFFERENT WITH THE NORTHERN STREAM OVER CANADA...USING EASTERN CANADIAN TROUGHING TO SINK THE CONFLUENCE...AND FRONTAL ZONE...SWD. THIS WOULD MAKE THE LATTER PORTION OF THE FCST MUCH WETTER AND COOLER THAN CURRENTLY CODED. AS PER HPC...IT AND TELECONNECTIONS DEPENDENT UPON SW CONUS TROUGH WILL PLAY A ROLE IN HOW FAR N THE FRONT IS OVER THE EASTERN CONUS DAYS 6-7. DRY WEATHER GIVES WAY TO INCREASING CHANCE FOR SHOWERS NW TO SE DAY 3 NT AND DAY 4 WITH INITIAL APPROACH OF FRONT AND INITIAL UPPER LEVEL WAVE. KEEP CHANCE THROUGH THE BALANCE OF THE FCST...HIGHEST N AND NW...LOWEST S AND SE...HAVE HAVE JUST SLIGHT CHANCE EARLY ON. MORE OR LESS EQUAL CHANCE FOR PRECIPITATION THROUGHOUT THE AREA DAY 7. ALSO INTRODUCED SLIGHT CHANCE FOR THUNDER DURING THE AFTERNOONS AND EARLY EVENINGS BEGINNING MON AS DEW POINTS INCREASE TO NEAR 50. BLENDED IN ADJMEXBC FOR HIGHS EARLY ON AND THEN HPC DAYS 6 AND 7 HIGHS AND ALL LOWS. ADJMEXBC APPEARED TOO LOW ON LOWS GIVEN SW FLOW...RISING DEW POINTS AND CLOUDS. && .AVIATION /10Z THURSDAY THROUGH MONDAY/... 12Z THURSDAY TO 12Z FRIDAY... LIGHT SURFACE WINDS BECOMING GUSTY AGAIN AFTER 15Z...MAINLY ACROSS THE HIGHER TERRAIN. A LOW PRESSURE SYSTEM WILL APPROACH FROM THE SOUTH LATE TDY...ALLOWING RA TO OVERSPREAD SW VA BY 18Z AND SLOWLY SPREADING N UP THE WV MTNS. THIS WILL CREATE GENERAL MVFR CONDITIONS ACROSS SOUTHWEST VA 18Z...SOUTHERN WV BY 00Z... AND UP WV MTNS BY 03Z. KEPT SOUTHEAST OHIO AND NORTHERN WV REMAINING VFR IN MID DECK. KHTS AND KCRW TRICKY AS THEY WILL BE ON THE NW FRINGE OF BEST LLVL MOISTURE AND PCPN. WILL KEEP THEM VFR WITH THIS ISSUANCE BUT ALLOW CIGS TO LWR INTO LOW END VFR. THERE MAY BE SOME FG OVERNIGHT FOR AREAS THAT RECEIVE RA AS THE LLVL FLOW REMAINS ON THE LIGHT SIDE. HOWEVER CONFIDENCE IS NOT PARTICULARLY HIGH TO INCLUDE IN TAFS ATTM. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY... FORECAST CONFIDENCE...MEDIUM. ALTERNATE SCENARIOS: LOW PRESSURE SYSTEM MAY SPREAD MOISTURE AND LOW CIGS FARTHER NORTH THAN CURRENTLY FORECAST TOWARDS THE END OF THE TAF PERIOD. FG MAY DEVELOP OVERNIGHT ACROSS AREAS THAT RECEIVE RA. 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 11 12 13 14 15 16 17 18 19 20 21 22 EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18 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 H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 12Z FRIDAY... NO WIDESPREAD IFR CONDITIONS EXPECTED. && .FIRE WEATHER... RH VALUES WILL AGAIN DIP INTO TEENS AND 20S PERCENT WISE AS DWPTS MIX DOWN INTO THE TEENS AND TEMPS CLIMB. MOISTURE ADV FROM S IN AFTN SHOULD ALLOW RH TO RECOVER UP TO CENTRAL WV WITH RA ACROSS SW VA. HOWEVER...ACROSS PORTIONS OF NE KY...SE OH AND N WV...THE DRY AIR WILL PREVAIL TDY. SOME AFTN GUSTS ARND 15 KTS MAY ALSO BE EXPECTED ACROSS N WV. WITH VERY DRY 10 HR FUELS IN PLACE...AN ENHANCED FIRE DANGER THREAT MAY BE REALIZED TODAY. CONDITIONS WILL BE MONITORED AND COORDINATED WITH THE APPROPRIATE STATE FORESTRY PERSONNEL FOR THE POTENTIAL FOR ANY FIRE WEATHER STATEMENTS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/RPY/30 NEAR TERM...30 SHORT TERM...RPY LONG TERM...TRM AVIATION...30 FIRE WEATHER...30
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
955 AM CDT THU APR 4 2013 .UPDATE... AN UPPER LEVEL LOW PRESSURE SYSTEM CURRENTLY LOCATED OVER THE ARKLATEX REGION WILL TRACK EAST ACROSS NORTH CENTRAL MISSISSIPPI TODAY. LOOKING AT THE LATEST HRRR MODEL...BEST RAIN CHANCES WILL OCCUR FROM EASTERN ARKANSAS TO NORTHWEST TENNESSEE. HAVE ADJUSTED POPS ACCORDINGLY. HAVE ALSO LOWERED HIGHS SLIGHTLY. EXPECT TEMPERATURES TO REMAIN IN THE UPPER 40S FOR HIGHS FOR THE MOST PART DUE TO THE CLOUDS AND RAIN. UPDATE WILL BE OUT SHORTLY. KRM && .DISCUSSION... /ISSUED 308 AM CDT THU APR 4 2013/ SKIES WERE CLOUDY ACROSS THE MIDSOUTH WITH A FEW AREAS OF LIGHT RAIN ON RADAR. WINDS WERE NORTHEAST AROUND 5 MPH WITH TEMPERATURES HOLDING IN THE MID AND UPPER 40S. ON SATELLITE AN UPPER LEVEL LOW WAS CENTERED IN SOUTHWEST OKLAHOMA WITH LEADING EDGE OF ASSOCIATED ENHANCED CLOUD COVER AND PRECIPITATION ENTERING WESTERN ARKANSAS. FOR TODAY AND TONIGHT...ONE LAST DREARY DAY FOR THE MIDSOUTH IN REGARDS TO RAIN AND UNSEASONABLY COLD TEMPERATURES. FORTUNATELY THE MODELS SHOW THE AFOREMENTIONED LOW BECOMING AN OPEN WAVE...AND BEGINNING TO FILL AS IT PASSES JUST TO OUR SOUTH THIS EVENING. THUS...RAINFALL AMOUNTS WILL LIKELY REMAIN UNDER A QUARTER OF AN INCH FOR MANY MIDSOUTHERNERS. TEMPERATURES WILL STRUGGLE TO REACH 50F ACROSS THE NORTH AND MID 50S SOUTH. AS THE LOW TRACKS INTO ALABAMA AND GEORGIA TONIGHT AN UPPER LEVEL RIDGE OVER THE PLAINS WILL QUICKLY BUILD INTO THE AREA. THIS SHOULD IN TURN ALLOW FOR FASTER CLEARING EARLY FRIDAY MORNING. WITH DRIER AIR WILL PUSHING IN FROM MISSOURI TEMPERATURES WILL EASILY CLIMB INTO THE MID 60S. THE REAL START TO THE MIDSOUTH WARMING TREND HOWEVER WILL BEGIN ON SATURDAY AS LOW LEVEL WINDS TURN SOUTHERLY. SKIES THOUGH...MAY BECOME PARTLY SUNNY THROUGHOUT THE DAY AS MODEL CROSS SECTIONS YIELD THICKENING CIRRUS CLOUDS EXTENDING WELL EAST OF THE ROCKIES. TEMPERATURES SHOULD STILL MANAGE TO MAKE IT INTO THE LOW AND MID 70S. GULF MOISTURE WILL BEGIN TO SURGE NORTHWARD SATURDAY NIGHT AND SUNDAY AS A COLD FRONT BECOMES STALLED ACROSS THE CORN BELT AND CENTRAL PLAINS. WAA WILL CONTINUE ON SUNDAY DEVELOPING A DEEP LAYER CAP BETWEEN 850 AND 700MB. THUS ANY ISOLATED CONVECTION FORMING WEST OF THE MISSISSIPPI RIVER WILL EITHER WAA SHOWERS OR ELEVATED THUNDER. HIGHS ON SUNDAY WILL REMAIN IN THE 70S WITH MILDER LOWS IN THE MID AND UPPER 50S. MONDAY THROUGH WEDNESDAY NIGHT...THIS PERIOD WILL SEE AN INCREASE THREAT FOR STORMS AND SEVERE WEATHER AS A NEW STORM DEEPENS OVER THE CENTRAL ROCKIES. THE UPPER FLOW OVER THE MIDSOUTH WILL BACK FROM THE SOUTHWEST WITH SPEEDS INCREASING. THE COMBINATION OF MINOR WAVES IN THE FLOW RIDING OVER THE STALLED BOUNDARY TO OUR NORTH AND DEWPOINTS INCREASING TO THE MID AND UPPER 60S...WILL WEAKEN THE ESTABLISHED CAP ALLOWING FOR SFC BASED CONVECTION. THE GFS AND EURO BOTH SPORT 1500+ J/KG OF CAPE...7.0C+ LAPSE RATES...AND LIFTED INDICES OF NEAR -6C. THE GFS ALSO IS INDICATING 0-1KM HELICITY VALUES IN EXCESS OF 3.0 M^2/S^2 INDICATING ROTATING STORMS. SINCE MODEL RUNS OVER THE PAST THREE DAYS HAVE BEEN CONSISTENT IN THE THREAT FOR SEVERE WEATHER FOR TUESDAY...WILL INTRODUCE THIS THREAT IN THE UPCOMING HWO. DEPENDENT ON AMOUNT OF CUMULUS CLOUD COVER/CONVECTION...DAYTIME HIGHS COULD WARM CLOSE TO 80F. SOUTH WINDS WILL ALSO INCREASE AND GUST TO 30MPH ON TUESDAY AS A SURFACE WAVE DEEPENS IN WEST TEXAS. THIS FEATURE IS PROGGED TO MOVE INTO THE OZARKS ON WEDNESDAY AND MAY PROVIDE A SECOND DAY THREAT FOR SEVERE WEATHER OVER OUR AREA. JAB && .AVIATION... 12Z TAF CYCLE (04/12Z-05/12Z) SURFACE LOW PRESSURE WILL MOVE ALONG THE NORTHEASTERN GULF COAST WHILE AN UPPER LEVEL TROUGH MOVES OVER THE MIDSOUTH TODAY. THIS WILL CAUSE RAIN ACROSS THE MIDSOUTH. FOR TODAY...THINK IFR CONDITIONS WILL PREDOMINATE AT KMEM...KMKL...AND KTUP WITH MVFR CONDITIONS AT KJBR. CONDITIONS THIS EVENING GRADUALLY IMPROVING TO VFR AT KMEM...KMKL...AND KJBR AS THE LOW PRESSURE SYSTEM MOVES EASTWARD AND THE RAIN ENDS. KTUP IS EXPECTED TO IMPROVE TO MVFR AROUND 05/06Z. WINDS TODAY NE 7-10 KTS. WINDS TONIGHT NORTHERLY 3-8 KTS. JCL && && .PRELIMINARY POINT TEMPS/POPS... MEM 48 42 66 49 / 80 40 0 0 MKL 48 39 65 43 / 80 50 0 0 JBR 49 39 66 44 / 80 30 0 0 TUP 49 43 65 43 / 60 50 10 0 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
334 PM CDT THU APR 4 2013 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 306 PM CDT THU APR 4 2013 LIGHT SURFACE PRESSURE GRADIENT IS EVIDENT IN 20Z RAP ANALYSIS. THIS LIGHT PRESSURE GRADIENT IS RESPONSIBLE FOR LIGHT WINDS WHICH ARE EVIDENT IN SURFACE OBSERVATIONS ACROSS THE FORECAST AREA THIS AFTERNOON. EXPECT THESE LIGHT WINDS TO EVENTUALLY SHIFT TO THE SOUTH OVERNIGHT TONIGHT AS A SURFACE LOW COMES INTO FORMATION OVER THE HIGH PLAINS. SOUTHERLY WINDS WILL INCREASE THROUGH THE DAY ON FRIDAY TO AROUND 20 TO 25 MPH...WITH GUSTS TO AROUND 30 MPH. DEEP MIXING WILL CAUSE ALLOW FOR LOW LEVEL WINDS AROUND 850 MB TO COME TO THE SURFACE...WHICH MAY BRING WARMER/DRYER CONDITIONS AND STRONGER WIND GUSTS. THIS WILL HAVE FIRE WEATHER IMPLICATIONS...WHICH ARE DISCUSSED IN THE FIRE WEATHER DISCUSSION BELOW. AT THIS TIME EXPECT VERY HIGH FIRE DANGER FOR MOST OF THE AREA THROUGH THE DAY ON FRIDAY. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 306 PM CDT THU APR 4 2013 FRIDAY NIGHT THROUGH SUNDAY...FRIDAY NIGHT LEE SIDE LOW PRESSURE DEEPENS OVER THE HIGH PLAINS INCREASING THE PRESSURE GRADIENT ACROSS THE AREA. THEREFORE THE WINDS WILL CONTINUE TO BE GUSTY THROUGH THE OVERNIGHT HOURS ESPECIALLY ACROSS EASTERN KANSAS. THIS WILL KEEP LOW TEMPERATURES FRIDAY NIGHT IN THE LOW 50S. A SOUTHWESTERLY LOW LEVEL JET INCREASES FRIDAY NIGHT BRINGING LIMITED MOISTURE TO THE REGION. MEANWHILE A SHORTWAVE ADVANCES EASTWARD INTO NEBRASKA AND EVENTUALLY IOWA ON SATURDAY. IT APPEARS THAT THE STRONGER LIFT ASSOCIATED WITH THE WAVE WILL BE NORTH OF THE AREA FRIDAY NIGHT AND SATURDAY MORNING. THERE IS SLIGHT CHANCE OF SOME WEAK LIFT EXTENDING SOUTH INTO KANSAS SO COULD NOT RULE OUT AN ISOLATED SHOWER FRIDAY NIGHT. A WEAK COLD FRONT ASSOCIATED WITH THE WAVE WILL PUSH SOUTHWARD THROUGH THE AREA DURING THE DAY ON SATURDAY SHIFTING THE WINDS TO THE NORTH. THE FRONT WILL RETREAT BACK TO THE NORTH ON SUNDAY AND SETS UP SOMEWHERE IN NORTHEAST KANSAS. A WEAK SHORTWAVE EMBEDDED IN THE ZONAL MID LEVEL FLOW PROGRESSES EASTWARD ACROSS KANSAS DURING THE DAY PROVIDING LAGER SCALE LIFT. SOUTHERLY LOW LEVEL FLOW WILL INCREASE THE MOISTURE RETURN ACROSS THE AREA AS ML CAPE VALUES APPROACH 500 J/KG AIDING IN THUNDERSTORM DEVELOPMENT. MID LEVEL FLOW ALSO INCREASES SUNDAY WITH 0-6 KM BULK SHEAR VALUES AROUND 40 KTS WHICH SUPPORTS THE CHANCE OF STRONGER ORGANIZED THUNDERSTORMS SUNDAY AFTERNOON AND OVERNIGHT. EXTENDED FORECAST (SUN NIGHT-THURS)...AN ACTIVE PATTERN SETTING UP THROUGH THIS PERIOD...AND SEVERE WEATHER APPEARS INCREASINGLY LIKELY....HOWEVER TIMING AND PLACEMENT REMAINS SOMEWHAT UNCERTAIN. SUNDAY NIGHT THE GFS AND A SOMEWHAT FASTER EC BRING A SHORTWAVE OVER THE WARMFRONT PROGGED E/W OVER OUR AREA...WITH THE EC HOLDING THE FRONT FARTHER SOUTH THAN THE GFS. ENOUGH CAPE AND SHEAR PRESENT THAT SOME OF THE STORMS OVERNIGHT COULD BRING HAIL. THE ENSUING WEATHER FOR MONDAY WILL BE DEPENDENT ON HOW FAR NORTH THE WARMFRONT LIFTS DURING THE DAY. EC AND GFS BOTH BREAK OUT CONVECTION NEAR THE BOUNDARY AND LESS SO IN THE WARM SECTOR MONDAY EVENING THROUGH THE MORNING HOURS ON TUESDAY. SEVERE WEATHER POTENTIAL CONTINUES TO INCREASE INTO TUESDAY AND TUESDAY AFTERNOON AS WESTERN TROF APPROACHES...AND SHEAR AND INSTABILITY ALSO INCREASE AND MOVE NORTH ACROSS THE CWA WITH THE WARM SECTOR. DIFFERENCES INCREASE BEYOND TUESDAY AS GFS MOVES THE COLDFRONT THROUGH QUICKLY WITH EC DROPPING A CLOSED UPPER LOW ACROSS EASTERN KANSAS AND THE FRONT MOVING THROUGH WEDNESDAY EVENING. WHILE WED/THURS WILL BRING A COOL END OF THE WEEK...MUCH UNCERTAINTY WITH PRECIP AMOUNTS AND TYPES. 67 && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1217 PM CDT THU APR 4 2013 EXPECT VFR CONDITIONS THROUGH FORECAST PERIOD WITH INCREASING SOUTHERLY WINDS FRIDAY MORNING/AFTERNOON 15 TO 25 MPH GUSTING TO 30 MPH. JL && .FIRE WEATHER... ISSUED AT 242 PM CDT THU APR 4 2013 WINDS ON FRIDAY WILL CHANGE FROM WNW OVERNIGHT TO THE SOUTH BY EARLY FRIDAY MORNING. BY FRIDAY AFTERNOON A STRONG SURFACE PRESSURE GRADIENT WILL FORM A CROSS CENTRAL AND EASTERN KANSAS CAUSING THE SOUTHERLY WINDS TO INCREASE TO AROUND 20 TO 25 MPH. DEEP MIXING TO AROUND 3000 FEET WILL ALLOW FOR SOME 30 TO 35 MPH WINDS TO REACH THE SURFACE AS WIND GUSTS LATER IN THE AFTERNOON ON FRIDAY. AT THIS TIME IT LOOKS AS THOUGH DEWPOINTS IN THE LOWER 40S WILL PUSH NORTHWARD INTO THE AREA. THIS WILL KEEP RH VALUES IN THE 30 TO 40 PERCENT RANGE...HOWEVER SHOULD DEEPER MIXING OCCUR THE DEWPOINTS COULD GO A BIT LOWER THAN CURRENTLY FORECAST...WHICH WOULD CAUSE RH VALUES TO DIP CLOSER TO 30 PERCENT. SINCE THE RH VALUES SHOULD REMAIN ABOVE 30 PERCENT WILL NOT ISSUE ANY KIND OF FIRE WEATHER HEADLINE...BUT STAY TUNED TO FORECAST UPDATES THROUGH THE DAY ON FRIDAY FOR MORE INFORMATION. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...LEIGHTON MID RANGE...SANDERS LONG TERM...67 AVIATION...LEIGHTON FIRE WEATHER...LEIGHTON
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1127 AM CDT THU APR 4 2013 .UPDATE... UPDATED AVIATION SECTION FOR 18Z TAFS ISSUED AT 928 AM CDT THU APR 4 2013 UPDATED THE GRIDS TO BETTER REFLECT ONGOING TRENDS. FARTHER SOUTH SHIFT IN THE MODELS LAST 24 HOURS WORKING OUT OK. ESSENTIALLY WILL BE A SHARP CUT OFF LINE FROM LIGHT RAINS AND SPRINKLES TO DRY CONDITIONS. TRIED TO BETTER REFLECT THIS IN THE POP GRIDS. NOT SURE HOW FAR NORTH THE LIGHT RAINS WILL BE ABLE TO MAKE IT. RAP MODELS SUGGESTS NOT MUCH FARTHER. GIVEN THE VERY DRY AIR SEEN ON 12 UPA DATA AT H9 AND H8...THAT APPEARS REASONABLE...ALTHOUGH WILL HEDGE JUST A TAD FARTHER NORTH THAN THE RAP. BROUGHT TEMPS DOWN A BIT CLOSE TO THE TN/AR BORDERS...ESPECIALLY OVER WEST KY NEAR THE TN STATE LINE. NORTH TOWARD I-64 WHERE SUN IS PRESENT TO START THE DAY...AND DRY AIR HOLDS...TEMPS SHOULD HAVE NO TROUBLE RISING STEADILY TO HIGHS IN THE MID TO UPPER 50S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 154 AM CDT THU APR 4 2013 RADAR SHOWS RETURNS TO OUR SOUTH PRODUCING SOME LIGHT RAIN. MODELS LIFT THIS LIGHT RAIN NORTHWARD TODAY...PEAKING THIS AFTERNOON...THEN SUBSIDING AND EVENTUALLY ENDING TONIGHT. THIS OCCURS AS AN UPPER LEVEL LOW MOVES FROM THE SRN PLAINS ACROSS THE MID-LOWER MS RIVER VALLEY. THE 00Z MODELING TRACK OF THIS DRIVING FEATURE IS SLIGHTLY FURTHER SOUTH THAN PREVIOUS RUNS...SO POPS WILL BE SLIGHTLY LESS THAN LAST NIGHT/PREVIOUS PACKAGES. OTHERWISE LITTLE CHANGE TO NEAR TERM FORECAST. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 154 AM CDT THU APR 4 2013 THE DRYING/WARMING WEEKEND IS STILL ON TAP. THE FLOW BECOMES LARGELY ZONAL AND ACTIVE...WITH A FRONT LAYING ACROSS/JUST TO OUR NORTH BY SUNDAY AND WAVES OF ENERGY RIDING ALONG IT. DEPENDING UPON WHERE THIS SETS UP EXACTLY...WE SHOULD SEE POPS ENTER THE FORECAST BY SUNDAY/MARKING THE BEGINNING OF AN ACTIVE/PERHAPS INCREASINGLY WET PATTERN AS WE MOVE INTO THE MID WEEK NEXT. THE EXTENDED RANGE MODELS DEVELOP LARGE SCALE TROFFING OVER THE CENTRAL U.S....AND THIS REALLY OPENS THE SWLYS ALOFT OVER US (WITH HIGH PRESSURE OFF THE SE U.S.) AND MAKES FOR A WET/ACTIVE MID WEEK. THIS INCLUDES AN INCREASING/DAILY POP/THUNDER WHICH MAY REACH INTO THE LIKELY CATEGORY BUT FOR NOW WE REMAIN AT HIGH CHANCE AND WILL ADJUST WITH TIME FROM DAY 7. && .AVIATION... ISSUED AT 1127 AM CDT THU APR 4 2013 WIDESPREAD MID AND HIGH CLOUDS ASSOCIATED WITH A STRONG UPPER LEVEL LOW PASSING TO OUR SOUTH WILL PERSIST THROUGH EARLY THIS EVENING. LOW CLOUDS WERE LURKING JUST TO THE SOUTHEAST OF KPAH AT 17Z. THESE LOWER CLOUDS MAY MOVE INTO THE KPAH AREA THIS AFTERNOON...BUT THE PROBABILITY WAS TOO LOW TO MENTION CIGS. OPTED INSTEAD TO MENTION A SCATTERED CLOUD DECK AROUND 4K FEET. SKIES WILL BECOME CLEAR BY 03Z WITH LIGHT WINDS TONIGHT. WINDS WILL BECOME NORTH AROUND 5 TO 10 KT FRIDAY MORNING. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
636 PM EDT THU APR 4 2013 .SYNOPSIS... LOW PRESSURE LIFTS NORTHEAST FROM THE GULF COAST THROUGH TONIGHT. THIS AREA OF LOW PRESSURE TRACKS ALONG THE SOUTHEAST COAST OVERNIGHT BEFORE SLIDING OFF THE MID ATLANTIC COAST FRIDAY. HIGH PRESSURE BUILDS OVER THE REGION SATURDAY AND SHIFTS OFFSHORE SUNDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... UPDATED GRIDS/ZFP PER RAPIDLY CHANGING CNDTNS ACROSS THE FA ATTM. NMRS RPTS OF SLEET MIXING IN WITH THE RAIN AT THE ONSET AS FAR EAST AS VA BCH...SO ADDED IP TO THE GRIDS NEXT FEW HRS. ALSO...DUE TO THE LARGE TMP/DP TMPS GAP...SFC TMPS QUICKLY FALLING INTO THE U30S-L40S WHERE PCPN CONTS TO SATURATE THE LYR. THUS...MADE CHANGES TO TMP GRIDS. CHALLENGING TMP FCST NEXT 6-12 HRS AS READINGS XPCTD TO LEVEL OFF AT SOME POINT ONCE THE RAIN SATURATES COLUMN THEN STDY OR SLOWLY RISE AFTR MIDNIGHT IN ADVANCE OF SFC LOW. TMPS MAY EVEN RISE INTO THE 50S ACROSS NRN OB/VA BCH AREAS LATE TONITE B4 FALLING BACK INTO THE 40S ONCE THE LOW MOVES NE. PVS DSCN: LATEST UPPER AIR ANALYSIS SHOWS A NORTHERN STREAM TROUGH TREKKING ACROSS ONTARIO THIS AFTN, AS A SOUTHERN STREAM TROUGH IS NOW ORIENTED OVER TEXARKANA/SOUTHERN MS VLY. AT THE SURFACE, WEAKENING ~1028MB SFC HIGH PRESSURE NOW ORIENTED JUST OFFSHORE, SETTING UP A HYBRID COLD AIR DAMMING WEDGE STRUCTURE OVER THE REGION. TO THE SOUTHWEST, A 1012MB LOW PRESSURE CENTER WAS CENTERED OVER THE FL PANHANDLE...WITH INVERTED COASTAL TROUGH ANALYZED OFFSHORE OF THE GA/SC COAST. LOW PRESSURE OVER THE SOUTHEAST WILL LIFT NORTHEAST AS MS VLY TROUGH WOBBLES EAST SOUTHEAST THROUGH THE EVENING. HAVE SEEN A HANDFUL OF SLEET REPORTS JUST TO OUR SOUTH/SOUTHWEST THANKS TO EVAPORATIONAL COOLING IN ANTECEDENT MODIFIED CP AIRMASS. ISENTROPIC UPGLIDE (290-300K SURFACES) RAMP UP QUICKLY LATE THIS AFTERNOON AND THIS EVENING AS SSW MID-LEVEL FLOW INCREASES ACROSS THE SOUTHEAST AND LOWER MID- ATLANTIC. THIS WILL SLOWLY SPREAD RAIN NORTH-NORTHEAST OVER THE AREA TONIGHT. RUC SOUNDINGS DO ARGUE FOR A BRIEF PERIOD OF SLEET ACROSS THE PIEDMONT, SOUTH CENTRAL VA/INTR NE NC, QUICKLY BECOMING ALL RAIN AS WAA CONTINUES AND LLVLS BECOME SATURATED. CONSIDERING ROAD TEMPS WELL ABOVE FREEZING, THIS SHOULD BE A MINIMAL IMPACT, BUT NONETHELESS WORTH MENTIONING IN THE GOING FORECAST. THE MID-LEVEL TROUGH TRACKS OVER THE DEEP SOUTH TONIGHT...WITH THE SURFACE LOW PRESSURE TRACKING NE OFF THE COAST ALONG THE COASTAL BOUNDARY...WITH SOME ADDITIONAL NUDGING FROM THE NORTHERN STREAM TROUGH. RATHER VIGOROUS VERTICAL ASCENT IS PROGGED TO MOVE NE ACROSS THE LOCAL AREA BETWEEN 00-09Z...WHICH SHOULD BRING A PERIOD OF MODERATE COLD RAIN TO MUCH OF THE AREA...CENTERED/HEAVIEST FROM S-CENTRAL VA TO THE EASTERN SHORE. BRIEF WINDOW OF MAINLY ELEVATED INSTABILITY ARRIVES AFTER MIDNIGHT. TOTAL TOTALS IN THE LOW 50S, WITH ENOUGH VERTICAL ASCENT TO OVERCOME NEUTRAL LI VALUES WOULD ARGUE FOR PERHAPS A RUMBLE OF THUNDER OR TWO ACROSS THE FAR SOUTHEAST, SO HV ADDED A SLIGHT RISK FOR THUNDER AFTER MIDNIGHT OVER FAR SE VA/NE NC. RAINFALL RATES SHOULD TAPER OFF QUICKLY AS THE PRIMARY FORCING MOVES OFF THE COAST TOWARDS DAWN FRIDAY MORNING. HOWEVER...LINGERING LOW-LEVEL MOISTURE SHOULD ALLOW FOR STRATUS AND AREAS OF LIGHT RAIN/DRIZZLE. QPF AMOUNTS RANGE FROM 0.5IN FAR NW...TO 1.25 ACROSS S-CENTRAL VA TO THE COASTAL ZONES. LOWS SHOULD RANGE FROM THE M/U 30S NW...TO THE MID 40S SE. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... LOW STRATUS AND AREAS OF LIGHT RA/DZ WILL LINGER FRIDAY MORNING, BEFORE GRADUALLY CLEARING FROM NW TO SE AS WINDS BACK TO THE N-NW. RAIN CHANCES ALSO DROP OFF QUICKLY AFTER 15Z AS MODEL CROSS SECTIONS SHOW MID-LEVELS DRYING OUT QUICKLY. HIGHS SHOULD RANGE FROM THE MID-UPPER 50S ALONG THE IMMEDIATE COAST...TO THE LOW 60S INLAND. HIGH PRESSURE BUILDS OVER THE AREA LATE FRIDAY NIGHT THROUGH SATURDAY MORNING, BEFORE SLIDING OFFSHORE LATER SATURDAY. QUASI-ZONAL/FLAT FLOW ALOFT ALLOWS DRIER AIR TO FILTER IN FROM THE WEST FRIDAY AND SATURDAY. THUS, APART FROM SOME DIURNALLY DRIVEN CUMULUS SATURDAY MORNING/AFTN, COURTESY OF ONSHORE (E-SE) LOW LEVEL FLOW, EXPECT A MAINLY CLEAR SKY DURING THIS PERIOD. BY SUNDAY, FLOW ALOFT OVER THE EASTERN THIRD OF THE COUNTRY BECOMES S-SW, AS UPPER TROUGH COMES ASHORE THE PACIFIC COAST. THIS SHOULD EVENTUALLY LEAD TO A WARM-UP BY LATE IN THE WEEKEND. CLEAR SKY/DRY AIRMASS SHOULD BRING CHILLY EARLY MORNING SATURDAY AND SUNDAY MORNINGS. LOWS FROM THE MID 30S N/NW TO LOW 40S SE COAST SAT MORNING...U30S TO MID 40S SUNDAY MORNING. FORECAST HIGHS SAT RANGE FROM THE UPPER 40S/LOW 50S ALONG THE IMMEDIATE ATLANTIC COAST OF THE EASTERN SHORE TO LOW 60S FROM THE I-95 CORRIDOR WEST. HIGHS WARM WELL INTO THE 60S ON SUNDAY, WITH LOW 70S LIKELY WEST OF THE CHES BAY. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... 12Z GFS/ECMWF IN GENERAL AGREEMENT SUN NGT INTO TUE MORNG...THEN ARE QUITE DIFFERENT FOR TUE THRU THU. GFS MAINTAINS A WARMER SCENARIO THRU THE PERIOD...KEEPING A FRNTL BOUNDARY N OF THE CWA WITH AN UA RDG BLDNG OVR THE MID ATLC REGION TUE THRU WED...THEN IT SLIDES OUT TO SEA WED NGT AND THU. WHILE...THE ECMWF KEEPS THE FRNTL BOUNDARY NW OR N OF THE CWA SUN NGT INTO TUE MORNG...THEN DROPS THE FRNT DOWN ACRS THE AREA TUE AFTN INTO WED...THEN LINGERING THE FRNT NEAR THE VA/NC BORDER THRU THU. AT THIS TIME GOING WITH THE WARMER GFS MODEL THRU THE PERIOD...WITH JUST A SLGT OR SML CHC FOR SHOWERS POSSIBLE WED THRU THU. MAX TEMPS WILL RANGE FM THE MID 60S TO MID 70S MON...AND IN THE UPR 60S TO UPR 70S TUE THRU THU. MIN TEMPS WILL BE IN THE MID 40S TO LWR 50S MON MORNG...AND MAINLY IN THE LWR TO MID 50S TUE...WED...AND THU MORNGS. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS WILL CONTINUE THIS AFTERNOON AS HIGH PRESSURE RETREATS TO THE EAST. HIGH CLOUDS WILL CONTINUE TO OVERSPREAD THE TAF SITES IN ADVANCE OF A LOW PRESSURE SYSTEM SLOWLY APPROACHING FROM THE SW. CIGS BEGIN TO LOWER LATER THIS AFTERNOON AS THE LOW MOVES NORTHWARD ALONG THE SE COAST. RAIN BEGINS BETWEEN 22Z/TODAY AND 01Z/FRI THEN CONTINUES OVERNIGHT BEFORE TAPERING OFF AROUND DAYBREAK FRIDAY. IFR CONDITIONS (MAINLY FOR CIGS) WILL BE LIKELY TONIGHT AT ALL TAF SITES...WITH PERIODS OF MODERATE RAIN AS WELL. LIFR CONDITIONS ARE POSSIBLE BUT NOT CONFIDENT ENUF TO INCLUDE IN THE TAFS ATTM. HI PRES BLDS IN LATE FRI INTO THE WEEKEND LEADING TO VFR CONDITIONS. && .MARINE... ESE THRU S FLO 5 TO 15 KTS EARLY THIS EVENG...WILL BECOME NE AND INCREASE TO 15 TO 20 KTS TNGT...AS INTENSIFYING LO PRES MOVES FM THE SE CST NNE TO JUST OFF THE MID ATLC CST BY 12Z FRI. THAT LO WILL CONTINUE TO INTENSIFY DURING FRI...AS IT MOVES AWAY TO THE NE AND HI PRES STARTS TO BLD IN FM THE NW. THE HI WILL MOVE TO RIGHT OVR THE REGION SAT MORNG. THIS WILL RESULT IN STRONG N WNDS FM FRI MORNG INTO SAT MORNG...WITH SCA`S FOR ALL WTRS EXCEPT THE RIVERS. HI PRES WILL THEN SLIDE OFF THE CST FOR SUN THRU AT LEAST MON. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 7 PM EDT FRIDAY FOR ANZ630>632-634. SMALL CRAFT ADVISORY FROM 6 AM TO 7 PM EDT FRIDAY FOR ANZ633. SMALL CRAFT ADVISORY FROM 4 AM FRIDAY TO NOON EDT SATURDAY FOR ANZ652-654. SMALL CRAFT ADVISORY FROM 1 AM FRIDAY TO NOON EDT SATURDAY FOR ANZ656. SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO NOON EDT SATURDAY FOR ANZ650. SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO NOON EDT SATURDAY FOR ANZ658. && $$ SYNOPSIS...MAM NEAR TERM...MPR/MAM SHORT TERM...MAM LONG TERM...TMG AVIATION...MAS MARINE...TMG
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
450 PM EDT THU APR 4 2013 .SYNOPSIS... LOW PRESSURE LIFTS NORTHEAST FROM THE GULF COAST THROUGH TONIGHT. THIS AREA OF LOW PRESSURE TRACKS ALONG THE SOUTHEAST COAST OVERNIGHT BEFORE SLIDING OFF THE MID ATLANTIC COAST FRIDAY. HIGH PRESSURE BUILDS OVER THE REGION SATURDAY AND SHIFTS OFFSHORE SUNDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... LATEST UPPER AIR ANALYSIS SHOWS A NORTHERN STREAM TROUGH TREKKING ACROSS ONTARIO THIS AFTN, AS A SOUTHERN STREAM TROUGH IS NOW ORIENTED OVER TEXARKANA/SOUTHERN MS VLY. AT THE SURFACE, WEAKENING ~1028MB SFC HIGH PRESSURE NOW ORIENTED JUST OFFSHORE, SETTING UP A HYBRID COLD AIR DAMMING WEDGE STRUCTURE OVER THE REGION. TO THE SOUTHWEST, A 1012MB LOW PRESSURE CENTER WAS CENTERED OVER THE FL PANHANDLE...WITH INVERTED COASTAL TROUGH ANALYZED OFFSHORE OF THE GA/SC COAST. LOW PRESSURE OVER THE SOUTHEAST WILL LIFT NORTHEAST AS MS VLY TROUGH WOBBLES EAST SOUTHEAST THROUGH THE EVENING. HAVE SEEN A HANDFUL OF SLEET REPORTS JUST TO OUR SOUTH/SOUTHWEST THANKS TO EVAPORATIONAL COOLING IN ANTECEDENT MODIFIED CP AIRMASS. ISENTROPIC UPGLIDE (290-300K SURFACES) RAMP UP QUICKLY LATE THIS AFTERNOON AND THIS EVENING AS SSW MID-LEVEL FLOW INCREASES ACROSS THE SOUTHEAST AND LOWER MID- ATLANTIC. THIS WILL SLOWLY SPREAD RAIN NORTH-NORTHEAST OVER THE AREA TONIGHT. RUC SOUNDINGS DO ARGUE FOR A BRIEF PERIOD OF SLEET ACROSS THE PIEDMONT, SOUTH CENTRAL VA/INTR NE NC, QUICKLY BECOMING ALL RAIN AS WAA CONTINUES AND LLVLS BECOME SATURATED. CONSIDERING ROAD TEMPS WELL ABOVE FREEZING, THIS SHOULD BE A MINIMAL IMPACT, BUT NONETHELESS WORTH MENTIONING IN THE GOING FORECAST. THE MID-LEVEL TROUGH TRACKS OVER THE DEEP SOUTH TONIGHT...WITH THE SURFACE LOW PRESSURE TRACKING NE OFF THE COAST ALONG THE COASTAL BOUNDARY...WITH SOME ADDITIONAL NUDGING FROM THE NORTHERN STREAM TROUGH. RATHER VIGOROUS VERTICAL ASCENT IS PROGGED TO MOVE NE ACROSS THE LOCAL AREA BETWEEN 00-09Z...WHICH SHOULD BRING A PERIOD OF MODERATE COLD RAIN TO MUCH OF THE AREA...CENTERED/HEAVIEST FROM S-CENTRAL VA TO THE EASTERN SHORE. BRIEF WINDOW OF MAINLY ELEVATED INSTABILITY ARRIVES AFTER MIDNIGHT. TOTAL TOTALS IN THE LOW 50S, WITH ENOUGH VERTICAL ASCENT TO OVERCOME NEUTRAL LI VALUES WOULD ARGUE FOR PERHAPS A RUMBLE OF THUNDER OR TWO ACROSS THE FAR SOUTHEAST, SO HV ADDED A SLIGHT RISK FOR THUNDER AFTER MIDNIGHT OVER FAR SE VA/NE NC. RAINFALL RATES SHOULD TAPER OFF QUICKLY AS THE PRIMARY FORCING MOVES OFF THE COAST TOWARDS DAWN FRIDAY MORNING. HOWEVER...LINGERING LOW-LEVEL MOISTURE SHOULD ALLOW FOR STRATUS AND AREAS OF LIGHT RAIN/DRIZZLE. QPF AMOUNTS RANGE FROM 0.5IN FAR NW...TO 1.25 ACROSS S-CENTRAL VA TO THE COASTAL ZONES. LOWS SHOULD RANGE FROM THE M/U 30S NW...TO THE MID 40S SE. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... LOW STRATUS AND AREAS OF LIGHT RA/DZ WILL LINGER FRIDAY MORNING, BEFORE GRADUALLY CLEARING FROM NW TO SE AS WINDS BACK TO THE N-NW. RAIN CHANCES ALSO DROP OFF QUICKLY AFTER 15Z AS MODEL CROSS SECTIONS SHOW MID-LEVELS DRYING OUT QUICKLY. HIGHS SHOULD RANGE FROM THE MID-UPPER 50S ALONG THE IMMEDIATE COAST...TO THE LOW 60S INLAND. HIGH PRESSURE BUILDS OVER THE AREA LATE FRIDAY NIGHT THROUGH SATURDAY MORNING, BEFORE SLIDING OFFSHORE LATER SATURDAY. QUASI-ZONAL/FLAT FLOW ALOFT ALLOWS DRIER AIR TO FILTER IN FROM THE WEST FRIDAY AND SATURDAY. THUS, APART FROM SOME DIURNALLY DRIVEN CUMULUS SATURDAY MORNING/AFTN, COURTESY OF ONSHORE (E-SE) LOW LEVEL FLOW, EXPECT A MAINLY CLEAR SKY DURING THIS PERIOD. BY SUNDAY, FLOW ALOFT OVER THE EASTERN THIRD OF THE COUNTRY BECOMES S-SW, AS UPPER TROUGH COMES ASHORE THE PACIFIC COAST. THIS SHOULD EVENTUALLY LEAD TO A WARM-UP BY LATE IN THE WEEKEND. CLEAR SKY/DRY AIRMASS SHOULD BRING CHILLY EARLY MORNING SATURDAY AND SUNDAY MORNINGS. LOWS FROM THE MID 30S N/NW TO LOW 40S SE COAST SAT MORNING...U30S TO MID 40S SUNDAY MORNING. FORECAST HIGHS SAT RANGE FROM THE UPPER 40S/LOW 50S ALONG THE IMMEDIATE ATLANTIC COAST OF THE EASTERN SHORE TO LOW 60S FROM THE I-95 CORRIDOR WEST. HIGHS WARM WELL INTO THE 60S ON SUNDAY, WITH LOW 70S LIKELY WEST OF THE CHES BAY. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... 12Z GFS/ECMWF IN GENERAL AGREEMENT SUN NGT INTO TUE MORNG...THEN ARE QUITE DIFFERENT FOR TUE THRU THU. GFS MAINTAINS A WARMER SCENARIO THRU THE PERIOD...KEEPING A FRNTL BOUNDARY N OF THE CWA WITH AN UA RDG BLDNG OVR THE MID ATLC REGION TUE THRU WED...THEN IT SLIDES OUT TO SEA WED NGT AND THU. WHILE...THE ECMWF KEEPS THE FRNTL BOUNDARY NW OR N OF THE CWA SUN NGT INTO TUE MORNG...THEN DROPS THE FRNT DOWN ACRS THE AREA TUE AFTN INTO WED...THEN LINGERING THE FRNT NEAR THE VA/NC BORDER THRU THU. AT THIS TIME GOING WITH THE WARMER GFS MODEL THRU THE PERIOD...WITH JUST A SLGT OR SML CHC FOR SHOWERS POSSIBLE WED THRU THU. MAX TEMPS WILL RANGE FM THE MID 60S TO MID 70S MON...AND IN THE UPR 60S TO UPR 70S TUE THRU THU. MIN TEMPS WILL BE IN THE MID 40S TO LWR 50S MON MORNG...AND MAINLY IN THE LWR TO MID 50S TUE...WED...AND THU MORNGS. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... VFR CONDITIONS WILL CONTINUE THIS AFTERNOON AS HIGH PRESSURE RETREATS TO THE EAST. HIGH CLOUDS WILL CONTINUE TO OVERSPREAD THE TAF SITES IN ADVANCE OF A LOW PRESSURE SYSTEM SLOWLY APPROACHING FROM THE SW. CIGS BEGIN TO LOWER LATER THIS AFTERNOON AS THE LOW MOVES NORTHWARD ALONG THE SE COAST. RAIN BEGINS BETWEEN 22Z/TODAY AND 01Z/FRI THEN CONTINUES OVERNIGHT BEFORE TAPERING OFF AROUND DAYBREAK FRIDAY. IFR CONDITIONS (MAINLY FOR CIGS) WILL BE LIKELY TONIGHT AT ALL TAF SITES...WITH PERIODS OF MODERATE RAIN AS WELL. LIFR CONDITIONS ARE POSSIBLE BUT NOT CONFIDENT ENUF TO INCLUDE IN THE TAFS ATTM. HI PRES BLDS IN LATE FRI INTO THE WEEKEND LEADING TO VFR CONDITIONS. && .MARINE... ESE THRU S FLO 5 TO 15 KTS EARLY THIS EVENG...WILL BECOME NE AND INCREASE TO 15 TO 20 KTS TNGT...AS INTENSIFYING LO PRES MOVES FM THE SE CST NNE TO JUST OFF THE MID ATLC CST BY 12Z FRI. THAT LO WILL CONTINUE TO INTENSIFY DURING FRI...AS IT MOVES AWAY TO THE NE AND HI PRES STARTS TO BLD IN FM THE NW. THE HI WILL MOVE TO RIGHT OVR THE REGION SAT MORNG. THIS WILL RESULT IN STRONG N WNDS FM FRI MORNG INTO SAT MORNG...WITH SCA`S FOR ALL WTRS EXCEPT THE RIVERS. HI PRES WILL THEN SLIDE OFF THE CST FOR SUN THRU AT LEAST MON. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 7 PM EDT FRIDAY FOR ANZ630>632-634. SMALL CRAFT ADVISORY FROM 6 AM TO 7 PM EDT FRIDAY FOR ANZ633. SMALL CRAFT ADVISORY FROM 4 AM FRIDAY TO NOON EDT SATURDAY FOR ANZ652-654. SMALL CRAFT ADVISORY FROM 1 AM FRIDAY TO NOON EDT SATURDAY FOR ANZ656. SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO NOON EDT SATURDAY FOR ANZ650. SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO NOON EDT SATURDAY FOR ANZ658. && $$ SYNOPSIS...MAM NEAR TERM...AJZ/MAM SHORT TERM...MAM LONG TERM...TMG AVIATION...MAS MARINE...TMG
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
410 PM EDT THU APR 4 2013 .SYNOPSIS... LOW PRESSURE LIFTS NORTHEAST FROM THE GULF COAST THROUGH TONIGHT. THIS AREA OF LOW PRESSURE TRACKS ALONG THE SOUTHEAST COAST OVERNIGHT BEFORE SLIDING OFF THE MID ATLANTIC COAST FRIDAY. HIGH PRESSURE BUILDS OVER THE REGION SATURDAY AND SHIFTS OFFSHORE SUNDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... LATEST UPPER AIR ANALYSIS SHOWS A NORTHERN STREAM TROUGH TREKKING ACROSS ONTARIO THIS AFTN, AS A SOUTHERN STREAM TROUGH IS NOW ORIENTED OVER TEXARKANA/SOUTHERN MS VLY. AT THE SURFACE, WEAKENING ~1028MB SFC HIGH PRESSURE NOW ORIENTED JUST OFFSHORE, SETTING UP A HYBRID COLD AIR DAMMING WEDGE STRUCTURE OVER THE REGION. TO THE SOUTHWEST, A 1012MB LOW PRESSURE CENTER WAS CENTERED OVER THE FL PANHANDLE...WITH INVERTED COASTAL TROUGH ANALYZED OFFSHORE OF THE GA/SC COAST. LOW PRESSURE OVER THE SOUTHEAST WILL LIFT NORTHEAST AS MS VLY TROUGH WOBBLES EAST SOUTHEAST THROUGH THE EVENING. HAVE SEEN A HANDFUL OF SLEET REPORTS JUST TO OUR SOUTH/SOUTHWEST THANKS TO EVAPORATIONAL COOLING IN ANTECEDENT MODIFIED CP AIRMASS. ISENTROPIC UPGLIDE (290-300K SURFACES) RAMP UP QUICKLY LATE THIS AFTERNOON AND THIS EVENING AS SSW MID-LEVEL FLOW INCREASES ACROSS THE SOUTHEAST AND LOWER MID- ATLANTIC. THIS WILL SLOWLY SPREAD RAIN NORTH-NORTHEAST OVER THE AREA TONIGHT. RUC SOUNDINGS DO ARGUE FOR A BRIEF PERIOD OF SLEET ACROSS THE PIEDMONT, SOUTH CENTRAL VA/INTR NE NC, QUICKLY BECOMING ALL RAIN AS WAA CONTINUES AND LLVLS BECOME SATURATED. CONSIDERING ROAD TEMPS WELL ABOVE FREEZING, THIS SHOULD BE A MINIMAL IMPACT, BUT NONETHELESS WORTH MENTIONING IN THE GOING FORECAST. THE MID-LEVEL TROUGH TRACKS OVER THE DEEP SOUTH TONIGHT...WITH THE SURFACE LOW PRESSURE TRACKING NE OFF THE COAST ALONG THE COASTAL BOUNDARY...WITH SOME ADDITIONAL NUDGING FROM THE NORTHERN STREAM TROUGH. RATHER VIGOROUS VERTICAL ASCENT IS PROGGED TO MOVE NE ACROSS THE LOCAL AREA BETWEEN 00-09Z...WHICH SHOULD BRING A PERIOD OF MODERATE COLD RAIN TO MUCH OF THE AREA...CENTERED/HEAVIEST FROM S-CENTRAL VA TO THE EASTERN SHORE. BRIEF WINDOW OF MAINLY ELEVATED INSTABILITY ARRIVES AFTER MIDNIGHT. TOTAL TOTALS IN THE LOW 50S, WITH ENOUGH VERTICAL ASCENT TO OVERCOME NEUTRAL LI VALUES WOULD ARGUE FOR PERHAPS A RUMBLE OF THUNDER OR TWO ACROSS THE FAR SOUTHEAST, SO HV ADDED A SLIGHT RISK FOR THUNDER AFTER MIDNIGHT OVER FAR SE VA/NE NC. RAINFALL RATES SHOULD TAPER OFF QUICKLY AS THE PRIMARY FORCING MOVES OFF THE COAST TOWARDS DAWN FRIDAY MORNING. HOWEVER...LINGERING LOW-LEVEL MOISTURE SHOULD ALLOW FOR STRATUS AND AREAS OF LIGHT RAIN/DRIZZLE. QPF AMOUNTS RANGE FROM 0.5IN FAR NW...TO 1.25 ACROSS S-CENTRAL VA TO THE COASTAL ZONES. LOWS SHOULD RANGE FROM THE M/U 30S NW...TO THE MID 40S SE. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... LOW STRATUS AND AREAS OF LIGHT RA/DZ WILL LINGER FRIDAY MORNING, BEFORE GRADUALLY CLEARING FROM NW TO SE AS WINDS BACK TO THE N-NW. RAIN CHANCES ALSO DROP OFF QUICKLY AFTER 15Z AS MODEL CROSS SECTIONS SHOW MID-LEVELS DRYING OUT QUICKLY. HIGHS SHOULD RANGE FROM THE MID-UPPER 50S ALONG THE IMMEDIATE COAST...TO THE LOW 60S INLAND. HIGH PRESSURE BUILDS OVER THE AREA LATE FRIDAY NIGHT THROUGH SATURDAY MORNING, BEFORE SLIDING OFFSHORE LATER SATURDAY. QUASI-ZONAL/FLAT FLOW ALOFT ALLOWS DRIER AIR TO FILTER IN FROM THE WEST FRIDAY AND SATURDAY. THUS, APART FROM SOME DIURNALLY DRIVEN CUMULUS SATURDAY MORNING/AFTN, COURTESY OF ONSHORE (E-SE) LOW LEVEL FLOW, EXPECT A MAINLY CLEAR SKY DURING THIS PERIOD. BY SUNDAY, FLOW ALOFT OVER THE EASTERN THIRD OF THE COUNTRY BECOMES S-SW, AS UPPER TROUGH COMES ASHORE THE PACIFIC COAST. THIS SHOULD EVENTUALLY LEAD TO A WARM-UP BY LATE IN THE WEEKEND. CLEAR SKY/DRY AIRMASS SHOULD BRING CHILLY EARLY MORNING SATURDAY AND SUNDAY MORNINGS. LOWS FROM THE MID 30S N/NW TO LOW 40S SE COAST SAT MORNING...U30S TO MID 40S SUNDAY MORNING. FORECAST HIGHS SAT RANGE FROM THE UPPER 40S/LOW 50S ALONG THE IMMEDIATE ATLANTIC COAST OF THE EASTERN SHORE TO LOW 60S FROM THE I-95 CORRIDOR WEST. HIGHS WARM WELL INTO THE 60S ON SUNDAY, WITH LOW 70S LIKELY WEST OF THE CHES BAY. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... 12Z GFS/ECMWF IN GENERAL AGREEMENT SAT NGT INTO MON NGT...THEN DIFFER TUE THRU WED WITH REGARD TO A BACKDOOR FRONT...WHICH THE ECMWF BRINGS DOWN INTO AND ACRS THE CWA TUE AFTN THRU WED. THE GFS BLDS THE UA RDG OVR THE MID ATLC REGION AND OFF THE CST DURING THIS TIME PERIOD. AT THIS TIME...LEANING TWD THE WARMER AND DRIER GFS THRU THE PERIOD...WITH ONLY A SLGT CHC OF SHOWERS FOR WED. SFC HI PRES WILL SLIDE OFF THE MID ATLC CST SAT NGT AND SUN...THEN MOVE FARTHER OUT TO SEA DURING WED. MAX TEMPS WILL RANGE THRU THE 60S SUN...THEN GENERALLY RANGE FM THE MID 60S TO MID 70S MON THRU WED. MIN TEMPS WILL BE IN THE MID 30S TO ARND 40 SUN MORNG...IN THE MID 40S TO ARND 50 MON MORNG...IN THE UPR 40S TO LWR 50S TUE MORNG...AND IN THE LWR TO MID 50S WED MORNG. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... VFR CONDITIONS WILL CONTINUE THIS AFTERNOON AS HIGH PRESSURE RETREATS TO THE EAST. HIGH CLOUDS WILL CONTINUE TO OVERSPREAD THE TAF SITES IN ADVANCE OF A LOW PRESSURE SYSTEM SLOWLY APPROACHING FROM THE SW. CIGS BEGIN TO LOWER LATER THIS AFTERNOON AS THE LOW MOVES NORTHWARD ALONG THE SE COAST. RAIN BEGINS BETWEEN 22Z/TODAY AND 01Z/FRI THEN CONTINUES OVERNIGHT BEFORE TAPERING OFF AROUND DAYBREAK FRIDAY. IFR CONDITIONS (MAINLY FOR CIGS) WILL BE LIKELY TONIGHT AT ALL TAF SITES...WITH PERIODS OF MODERATE RAIN AS WELL. LIFR CONDITIONS ARE POSSIBLE BUT NOT CONFIDENT ENUF TO INCLUDE IN THE TAFS ATTM. HI PRES BLDS IN LATE FRI INTO THE WEEKEND LEADING TO VFR CONDITIONS. && .MARINE... LIGHT NE FLOW THIS MORNING BECOMES E AND SE THIS AFTERNOON AS HIGH PRESSURE SLIDES OFF THE CST...FOLLOWED BY INTENSIFYING LOW PRESSURE TRACKING FROM THE GULF COAST STATES NE UP AND OFF THE MID ATLC CST THIS EVENING THRU FRIDAY MORNING. SOLID SCA CONDITIONS ARE EXPECTED TO DEVELOP ON THE COASTAL WATERS TONIGHT AS THE LOW INTENSIFIES AND SEAS BUILD TO AT LEAST 5-8 FT. WIND GUSTS TO 30 KT WILL ALSO BE POSSIBLE ON FRIDAY. ON THE CHESAPEAKE BAY...WINDS INCREASE TO SCA LEVELS THIS EVENING AND CONTINUE THRU FRIDAY. HAVE ACCORDINGLY HOISTED SCA HEADLINES FOR THE BAY AND COASTAL WATERS BEGINNING THIS EVENING. BECAUSE OF HIGH CONFIDENCE IN SEAS REMAINING ELEVATED THRU AT LEAST FRI NIGHT...HAVE THE SCA`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
AREA FORECAST DISCUSSION
NWS GAYLORD MI
347 PM EDT THU APR 4 2013 .SYNOPSIS... ISSUED AT 344 PM EDT THU APR 4 2013 A COLD FRONT IS MOVING THROUGH NORTHERN MICHIGAN...BRINGING A PERIOD OF LIGHT RAIN AND SNOW FOR THIS AFTERNOON AND TONIGHT. SETTLED WEATHER WILL RETURN FOR A SHORT TIME ON FRIDAY...BEFORE ANOTHER STORM SYSTEM MOVES INTO NORTHERN MICHIGAN...BRINGING RAIN AND SNOW MIXED FOR SATURDAY INTO SUNDAY. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 344 PM EDT THU APR 4 2013 THE CURRENT RADAR SHOWS A NARROW BAND OF PCPN SLOWLY DROPPING SOUTH ACROSS NORTHERN LOWER MICHIGAN. THIS NARROW AREA OF PRECIPITATION IS THE RESULT OF A COLD FRONT SINKING SOUTH OVER THE REGION. VIS SAT AND SFC OBS SHOW LIMITED MOISTURE EITHER SIDE OF THE BOUNDARY...WITH MOSTLY SUNNY SKIES OVER MUCH OF CENTRAL AND SOUTHERN MICHIGAN. SUN OVER THE SRN CWA FROM EARLIER TODAY...HAS ALLOWED AFTERNOON TEMPS IN THESE AREAS TO WARM QUICKLY INTO THE MID AND UPPER 40S...WHILE TEMPS REMAIN IN THE 30S OVER ERN UPPER NORTH OF THE BOUNDARY. OVERALL THE MAIN FORECAST CONCERNS TONIGHT THROUGH FRIDAY WILL BE TIMING AND TYPE OF PCPN TONIGHT WITH THE APPROACHING FRONT...ALONG WITH ANY LAKE INDUCED SNOWS FRIDAY ON THE BACKSIDE OF THE COLD FRONT. THE STORM SYSTEM CURRENTLY MOVING ACRS ONTARIO WILL QUICKLY EXIT INTO QUEBEC THIS EVENING. A COLD FRONT ASSOCIATED WITH THIS SYSTEM... WILL CONT TO DROP SOUTH ACRS NRN LWR MI THIS EVENING BEFORE EXITING EAST. EXPECT THE FRONT TO HAVE CLEARED NORTHERN LOWER MICHIGAN BTWN 03Z AND 06Z. THE ONLY PCPN ASSOCIATED WITH THIS BOUNDARY HAS BEEN LOCATED RIGHT ALONG THE FRONT...DUE TO THE EXTREMELY DRY AIR LOCATED OVER THE GREAT LAKES. HOWEVER SFC DEW PTS EVENTUALLY INCREASED FROM THE TEENS INTO THE MID 20S OVER THE STRAITS AS THE FRONT APPROACHED (ENOUGH TO GENERATE PCPN). HOWEVER PCPN TYPE AND CHC OVER THE REST OF THE CWA WILL BE DIFFICULT THIS EVENING AS THE FRONT DIPS SOUTH. TO THIS POINT...ALL OF THE PCPN HAS BEEN IN THE FORM OF SNOW OVER ERN UPPER AND THE STRAITS. THE LATEST RUC MODEL SOUNDINGS SHOW AN INVERTED V SIGNATURE IN THE LOWEST LAYERS FROM GAYLORD SOUTH TO THE SAGINAW BAY THIS EVENING...WITH OTHERWISE EXTREMELY DRY AIR ABOVE 850MB. ADDING COMPLICATIONS TO PCPN TYPE THIS EVENING IS THE VERTICAL TEMP PROFILES...AS MOST OF NRN LWR WARMED WELL INTO THE MID AND UPPER 40S DUE TO SOUTHWEST WINDS AND FULL SUN IN ADVANCE OF THE FRONT. HOWEVER PROGGED 850MB WET BULB TEMPS WOULD SUGGEST ENOUGH EVAP COOLING WITH ONSET OF ADVANCING MSTR TO AT LEAST MENTION A RAIN/SNOW MIX. OVERALL WILL CONTINUE THE LATEST TREND OF CHC POPS RAIN/SNOW MIXED OVER THE SRN HALF OF THE CWA AND SAGINAW BAY INTO THIS EVENING. COLDER AIR AND NORTHWEST FLOW RE-SETTLES INTO THE REGION OVERNIGHT AND FRIDAY ON THE BACK SIDE OF THE EXITING BOUNDARY. 850MB TEMPS QUICKLY DROP FROM ARND -4C THIS EVENING TO BETWEEN -12C AND -14C BY 12Z FRIDAY. SFC-850MB WINDS TURN FROM THE SOUTHWEST THIS EVENING IN ADVANCE OF THE BOUNDARY TO NNW FRIDAY. MODEL SOUNDINGS SUGGEST INVERSION HEIGHTS INCREASING TO NEAR 5K FT WHILE LINGERING LOW LVL MSTR EXTENDS TO AROUND THE -12C ISOTHERM. OVERALL MENTION CHC POPS IN NORTH FLOW SNOW BELTS EARLY FRIDAY. OTHERWISE WILL MENTION AT LEAST PARTLY SUNNY SKIES OVER THE REST OF THE CWA FRIDAY. WILL MENTION COOLER AFTN TEMPS FRIDAY...RANGING FROM AROUND FREEZING OVER ERN UPPER AND THE STRAITS TO THE LOWER 40S NEAR SAGINAW BAY. && .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 344 PM EDT THU APR 4 2013 LITTLE CHANGE FROM WHAT WAS SEEN YESTERDAY...WITH STILL PLENTY OF POTENTIAL FOR A VERY ACTIVE NEXT 7 DAYS OF WEATHER AS PERSISTENT -AO RELAXES AND DEEP SOUTHWEST MOISTURE RICH FLOW DEVELOPS ON FRONTSIDE OF DIGGING INTERMOUNTAIN WEST ENERGY. BIG WILD CARD REMAINS POTENTIAL INTERACTION WITH POLAR LOW SET TO ROTATE ACROSS EASTERN CANADA. EVENTUAL PLACEMENT OF THIS FEATURE WILL BE KEY IN DETERMINING LOCATION OF INTENSE LOW LEVEL THERMAL BOUNDARY AND SUBSEQUENT PATHWAY FOR ENERGY ROTATING OUT OF WESTERN TROUGH AXIS. WHILE ABOVE REMAINS A VERY LOW CONFIDENCE PORTION OF THE FORECAST...LEAD WAVE APPROACHING THE PACIFIC NORTHWEST (NICELY ILLUSTRATED ON LATEST WATER VAPOR IMAGERY) NOW WELL AGREED UPON TO IMPACT OUR WEATHER INTO THE START OF THIS WEEKEND. THIS WAVE WILL BRING ANOTHER BOUT OF WINTRY WEATHER TO THE NORTH WOODS SATURDAY...WITH INCREASING CONFIDENCE PARTS OF EASTERN UPPER WILL SEE A PERIOD OF ACCUMULATING SNOW. FORECAST CONCERNS INITIALLY DEAL WITH THIS LATTER SYSTEM...SPECIFICALLY SNOWFALL ACCUMULATIONS FOR EASTERN UPPER. MUCH MORE OF PROBABILISTIC APPROACH TAKING FOR THE REMAINDER OF THE FORECAST...WITH AT LEAST SOME ATTEMPT AT ADDRESSING MULTI- PERIOD PRECIP CHANCES AND TEMPERATURE TRENDS. GUIDANCE HAS LOCKED IN A SOLUTION SENDING PACIFIC NORTHWEST WAVE RAPIDLY EAST INTO THE NORTHERN PLAIN FRIDAY NIGHT...AND THROUGH NORTHERN MICHIGAN BY SATURDAY NIGHT. WEAKISH COUPLED JET STRUCTURE AND LOW LEVEL THERMAL BOUNDARY EXPECTED TO ENTICE RESPECTABLE SURFACE LOW PRESSURE DEVELOPMENT WITH THIS MID LEVEL WAVE...ITSELF EXPECTED TO SLICE THROUGH THE HEART OF NORTHERN LOWER MICHIGAN SATURDAY EVENING. ALTHOUGH WAVE ITSELF AND SURFACE FEATURE NOTHING TO WRITE HOME ABOUT...ACCOMPANYING DYNAMICS REMAIN IMPRESSIVE INDEED. MULTI-PERIOD TRENDS CONTINUE TO SUPPORT AGGRESSIVE WAA DRIVEN DYNAMICS...WITH NEAR 60 KNOT SOUTHWEST FLOW LOW LEVEL JET PERPENDICULAR TO THE 290K-295K PRESSURE SURFACES. DEEP LAYER FGEN SIGNAL ALSO PRESENT ALONG RETREATING COLD DOME...COLLOCATED NICELY WITH MAX WAA UPGLIDE ON NOSE OF LOW LEVEL JET. BEST JUXTAPOSITION OF THE ABOVE EXPECTED ACROSS FAR NORTHERN LOWER AND AREAS NORTH OF THE BRIDGE SATURDAY INTO SATURDAY EVENING. SYSTEM HAS A NICE SUBTROPICAL PACIFIC MOISTURE PLUME ALREADY ASSOCIATED WITH IT...SOME OF WHICH WILL BE ADVECTED INTO OUR AREA AS SYSTEM APPROACHES. COMBINE THIS WITH BRIEF WINDOW FOR SOME WESTERN GULF OF MEXICO MOISTURE CONTRIBUTION...AND PWAT VALUES SURGE TO AOA 0.75 INCHES LEVELS BY LATER SATURDAY. SAID ISENTROPIC SURFACES ALSO SHOW VERY RESPECTABLE MOISTURE...WITH MIXING RATIOS EXCEEDING 4 G/KG. LITTLE DOUBT SYSTEM HAS ALL THE EARMARKS TO BE A RATHER SUBSTANTIAL PRECIP PRODUCER... ALTHOUGH EXACTLY WHAT TYPE THAT PRECIP TAKES REMAINS A FORMIDABLE CHALLENGE. WILL USE ROCK-STEADY ECMWF DEPICTIONS FOR THERMAL FIELDS. THIS CONTINUES TO SUGGEST MAINLY SNOW AT THE ONSET EARLY SATURDAY...RAPIDLY CHANGING OVER TO LIQUID FROM SOUTHWEST TO NORTHEAST ACROSS NORTHERN LOWER MICHIGAN DURING THE MORNING. COULD SEE SOME MINOR SNOW ACCUMULATIONS...ON THE ORDER OF AN INCH OR SO...ESPECIALLY ACROSS THE HIGHER TERRAIN AREAS. WILL NEED TO WATCH FOR A PERIOD OF FREEZING RAIN AS WAA STRENGTHENS JUST OFF THE DECK. THIS SHOULD BE SHORT-LIVED EVENT (IF IT OCCURS AT ALL) AND NOT WORTHY OF A MENTION IN THE FORECAST. MUCH BIGGER PRECIP TYPE CHALLENGE ACROSS EASTERN UPPER...WITH STRONG DYNAMICS POSSIBLY OVERCOMING MARGINAL THERMAL PROFILES TO KEEP PRECIP MAINLY ALL SNOW...ESPECIALLY ALONG AND NORTH OF M-28. MODEL QPF FIELDS SOMEWHAT DISCONCERTING...WITH PROGS SUPPORTING A HALF INCH OR MORE OF LIQUID EQUIVALENT PRECIP BY LATER SATURDAY NIGHT. HEAVIER AMOUNTS NO DOUBT POSSIBLE GIVEN AMOUNT OF EARLIER MENTIONED DYNAMICS. SNOW RATIOS WILL NOT BE GREAT...ESPECIALLY SATURDAY AFTERNOON...WHEN SURFACE READINGS WILL LIKELY EXCEED FREEZING AND HIGH APRIL SUN ANGLE TAKES HOLD. STILL...COULD EASILY SEE SEVERAL INCHES OF HEAVY WET SNOW ACCUMULATION BY LATER SATURDAY NIGHT...WITH PERIODS OF HIGH INTENSITY SNOWFALL. NO HEADLINES FORTHCOMING ON THIS SHIFT...BUT IF ABOVE COMES TO FRUITION...COULD SEE ADVISORY LEVEL SNOW AMOUNTS FOR AT LEAST PARTS OF EASTERN UPPER. STAY TUNED! SYSTEM WINDS DOWN QUICKLY LATE SATURDAY NIGHT...LEAVING BEHIND A DRY SUNDAY AND SUNDAY EVENING. CONFIDENCE DROPS REMARKABLY HEADING THROUGH NEXT WORK WEEK...WITH GUIDANCE STRUGGLING WITH KEY INTERACTIONS TALKED ABOUT IN THE LEAD PARAGRAPH. PLENTY OF POTENTIAL FOR ADDITIONAL SIGNIFICANT SYSTEMS...WITH SOME DECENT SUPPORT FOR ONE SUCH SYSTEM TO IMPACT OUR AREA TO KICK OFF THE WEEK. EXACTLY HOW FAR NORTH THIS SYSTEM RIDES UP THROUGH THE OHIO VALLEY/SOUTHERN LAKES STILL FAR FROM BEING DETERMINED. DEPENDING ON SUCH...MAY SEE ENOUGH COLD AIR ALONG THE NORTHERN PERIPHERY OF ITS PRECIP SHIELD TO SUPPORT SOME WINTRY WEATHER. NO NEED TO GET TOO SPECIFIC...AND WILL BE FORCED TO RUN WITH A GUIDANCE CONSENSUS BLEND UNTIL A MORE DETERMINISTIC APPROACH CAN BE UTILIZED. SAME STORY HEADING THROUGH THE REMAINDER OF THE WEEK...WITH AGAIN THE POTENTIAL FOR ANOTHER WAVE TO ROTATE NORTHEAST OUT OF THE SOUTHERN PLAINS. TIMING AND PLACEMENT OF SUCH ALL OVER THE BOARD...AS IT WILL LIKELY REMAIN WITH BAROCLINIC AXIS SUBJECT TO MANY CHANGES PER CANADIAN TROUGHING AND PASSAGE OF EARLIER IN THE WEEK SYSTEMS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 156 PM EDT THU APR 4 2013 VFR CIGS AND VSBY IN ADVANCE OF A FRONTAL BOUNDARY DROPPING SOUTH ACRS NRN LWR MI...WILL TREND MVFR AND OCCASIONALLY IFR IN MIXED RAIN AND SNOW THROUGH BTWN 00Z AND 03Z. COLDER AIR AND NORTHWEST WINDS ON THE BACK SIDE OF THE EXITING SYSTEM...WILL GENERATE SOME LAKE SNOWS OVER TAF SITE KTVC AND KMBL FRIDAY. GUSTY SOUTHWEST WINDS IN ADVANCE OF THE BOUNDARY...WILL TREND NORTHWEST ACRS NRN LWR MI TAF SITES BTWN 00Z AND 06Z. && .MARINE... ISSUED AT 344 PM EDT THU APR 4 2013 GUSTY SOUTHWEST WINDS IN ADVANCE OF A FRONTAL BOUNDARY DROPPING SOUTH OVER NRN MI...WILL TURN NORTHWEST OVERNIGHT AND REMAIN BREEZY ON THE BACKSIDE OF THE EXITING BOUNDARY. RAIN/SNOW MIXED PCPN WILL AFFECT NRN MI NEARSHORE WATERS THIS EVENING AS BOUNDARY DROPS SOUTH...WITH SOME LAKE SNOWS POSSIBLE FRIDAY BEHIND THE FRONT. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LHZ345>349. LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ323-345- 346. GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LMZ341-342-344. LS...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LSZ321-322. && $$ SYNOPSIS...KAB SHORT TERM...SWR LONG TERM...MSB AVIATION...SWR MARINE...SWR
AREA FORECAST DISCUSSION
NWS GAYLORD MI
158 PM EDT THU APR 4 2013 .SYNOPSIS... ISSUED AT 420 AM EDT THU APR 4 2013 A COLD FRONT WILL MOVE THROUGH NORTHERN MICHIGAN TODAY. PRECIPITATION ASSOCIATED WITH THIS FRONT WILL START AS SNOW THIS MORNING...BUT MIX WITH RAIN AS THE TEMPERATURES RISE ABOVE FREEZING TODAY. THE RAIN WILL END IN THE AFTERNOON AS DRIER TAKES OVER BEFORE THE FRONT MOVES THROUGH. HIGH PRESSURE AND COOLER TEMPERATURES WILL SETTLE IN FOR THURSDAY NIGHT AND FRIDAY BEFORE A STORM SYSTEM MOVES INTO NORTHERN MICHIGAN AND HANGS AROUND FOR MUCH OF THE WEEKEND...BRINGING RAIN AND SNOW MIXED FOR SATURDAY AND SUNDAY. && .UPDATE... ISSUED AT 156 PM EDT THU APR 4 2013 THE CURRENT FORECAST IS IN LINE...AS A FRONTAL BOUNDARY CONTINUES TO DROP SOUTH ACRS NRN LWR MI. UPDATE ISSUED AT 933 AM EDT THU APR 4 2013 CURRENT RADAR AND SFC OBS SHOWING AREA OF PCPN OVER ERN UPPER AND STRAITS REGION...WHICH IS IN RESPONSE TO A COLD FRONT PUSHING INTO THE WRN LAKES. PCPN ASSOCIATED WITH THIS FRONT SO FAR THIS MORNING HAS BEEN CONFINED TO A NARROW BAND...HINDERED GREATLY BY LIMITED MSTR. SFC DEW PTS SOUTH OF THE STRAITS ARE CURRENTLY IN THE TEENS...THOUGH DEW PTS HAVE INCREASED INTO THE LOWER AND MID 20 OVER ERN UPPER JUST IN ADVANCE OF THE FRONT. AS FOR THE REST OF TODAY...LIMITED MSTR WILL REMAIN A HINDRANCE THROUGH THE AFTERNOON OVR NRN LWR MI...KEEPING ANY PCPN CONFINED TO A NARROW AREA RIGHT ALONG THE FRONT. MODEL SOUNDINGS SHOW PCPN CHCS ENDING FROM GLR NORTH BTWN 18Z AND 21Z...AND ENDING NEAR SAGINAW BAY REGION BETWEEN 00Z AND 03Z. OVERALL CURRENT FCST IN LINE WITH MILD TEMP AND SUN EARLY OVER THE SRN CWA...WITH PCPN ENDING OVER ERN UPPER EARLY THIS AFTN. UPDATE ISSUED AT 607 AM EDT THU APR 4 2013 CHANGES THIS HOUR: HAVE CONTINUED SLOWING TREND OF POPS THROUGH MUCH OF TODAY GIVEN RECENT GOOD AGREEMENT BETWEEN THE NAM/RAP/HRRR GIVEN VERY IMPRESSIVE PERFORMANCE FROM THE RAP OVER THE PAST FEW HOURS. SNOWFALL HAS ARRIVED FROM SAW-ERY-ANJ AND WILL GO AHEAD AND BUMP UP NEAR TERM POPS TO CATEGORICAL FOR NORTHERN CHIPPEWA THROUGH DAYBREAK. BEYOND THIS...INITIAL SURGE OF ISENTROPIC ASCENT ALONG LLEVEL MOISTURE AXIS WILL SHIFT EAST AND WE/LL THEN AWAIT FURTHER DEVELOPMENT ALONG THE FRONTAL BOUNDARY ITSELF...WHICH IS NOW SLIDING SOUTHEAST THROUGH WESTERN UPPER. DON/T EXPECT THIS TO BE SUBSTANTIAL...AND AS PREVIOUSLY MENTIONED...EXPECT IT TO DWINDLE AS IT HEADS SOUTH...WITH RAIN GRADUALLY TAKING OVER AS THE PREDOMINATE PRECIPITATION TYPE. COULD SEE AN INCH OF MORNING ACCUMS FROM PARADISE TO ANJ /WEBCAMS SHOW A COATING ATTM/...SO WATCH OUT FOR SOME SLICK AM TRAVEL IN THESE SPOTS. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 420 AM EDT THU APR 4 2013 HIGH IMPACT WEATHER POTENTIAL: GALE FORCE WINDS OVER MUCH OF NORTHERN LAKE MICHIGAN THROUGH MID MORNING. WILL LIKELY HAVE SOME COASTAL WIND GUSTS ABOVE 30 MPH TODAY...OTHERWISE...NO HIGH IMPACT WEATHER EXPECTED. OVERVIEW: SURFACE MAP EARLY THIS MORNING REVEALS HIGH PRESSURE RESPONSIBLE FOR THE BEAUTIFUL /ALBEIT CHILLY/ AFTERNOON YESTERDAY HAVING PUSHED SOUTH AND EAST INTO THE OHIO VALLEY/MID ATLANTIC REGION...THIS HAS ALLOWED BROAD SOUTHWESTERLY FLOW TO DEVELOP BETWEEN THIS FEATURE AND RATHER IMPRESSIVE SURFACE LOW NOW TRAVELING FROM WEST TO EAST ACROSS NORTHERN ONTARIO. PRIMARY FEATURE OF NOTE THROUGH THE SHORT TERM PORTION OF THE FORECAST IS A COLD FRONT DRAPED TO THE SOUTH AND WEST OF THIS LOW...APPROACHING LAKE SUPERIOR AS OF THIS WRITING. STRENGTHENING SOUTHWESTERLY WINDS OVER NORTHERN MICHIGAN HAVE PRECLUDED STEEP TEMPERATURE FALLS OVERNIGHT WITH MOST LOCATIONS AT LEAST 10F WARMER THAN 24 HOURS AGO. LLEVEL MOISTURE HAS NOT RESPONDED IN TANDEM...WITH 00Z APX RAOB SHOWING A PALTRY 0.14" PWAT. CLOSER TO THE FRONT...HOWEVER...PRECIPITATION ECHOES HAVE BEEN BLOSSOMING OVER THE PAST COUPLE OF HOURS AS ROBUST LOW LEVEL JET AT H8 /50KTS+/ TRANSPORTS A PLUME OF 2/3" PWATS RAPIDLY EASTWARD. THROUGH DAYBREAK: WINDS CONTINUE TO RAMP UP FROM WEST TO EAST...WITH SLOWLY INCREASING MID AND UPPER LEVEL CLOUDINESS...PRIMARILY FROM THE STRAITS NORTH. TIMING AREA OF INCREASING RADAR ECHOES SUGGESTS PRECIPITATION COULD ARRIVE AS EARLY AS 5-6AM OVER EASTERN UPPER AS SOME SNOW SHOWERS. INTERESTING TO NOTE SURFACE DEWPOINT TREND OVER THE PAST FEW HOURS OVER NORTHERN LOWER...WITH VALUES PLUMMETING TO BELOW 10F AT TVC/CAD AND ROPPING EVERYWHERE AWAY FROM LAKE MICHIGAN. THIS SUGGESTS THE SLOWING TREND IN FRONTAL PRECIP ARRIVAL /SEEN IN RECENT RENDTIONS OF THE HRRR/RAP/ ARE LIKELY ON THE RIGHT TRACK. TODAY: COLD FRONT PUSHES THROUGH NORTHERN MICHIGAN TODAY...STARTING THE DAY OVER WESTERN UPPER AND REACHING MY SOUTHEASTERN ZONES BY EVENING. PRIMARY CONCERNS TODAY CENTER AROUND PRECIPITATION CHANCES AS THIS BOUNDARY MOVES THROUGH...AS WELL AS THE STRENGTH OF SOUTHWESTERLY WINDS AHEAD OF IT. TRAJECTORY ANALYSIS SHOWS LLEVEL SOURCE REGION FOR AIR OVER NORTHERN LOWER TODAY COMES FROM THE IOWA/ILLINOIS REGION 24 HOURS AGO...AN AREA FEATURING A DEARTH OF LLEVEL MOISTURE. SO...BOUNDARY WILL BE FIGHTING INCREASINGLY DRY ATMOSPHERE AS IT PUSHES SOUTH AND EAST WITH LLEVEL MOISTURE TONGUE THINNING. LLEVEL CONVERGENCE IS MODEST...BUT WILL HAVE SOME HELP FROM AN ARRIVING JET MAX /AND ITS ASSOCIATED RIGHT ENTRANCE REGION/ AS WELL AS CONTINUED ISENTROPIC ASCENT. NET RESULT: EXPECT A BROKEN LINE OF SHOWERS TO SINK SOUTH DURING THE DAY...WEAKENING AS THEY DO SO. RECENT MODEL TRENDS HAVE CONTINUED TO SLOW THE SOUTHWARD MOVEMENT OF ANY PRECIPITATION... AND WHILE THIS FORECAST REPRESENTS A SLOWING TREND...IT COULD REQUIRE FURTHER SLOWING WITH PRECIITATION POTENTIALLY COMPLETELY FALLING APART BEFORE MAKING IT MUCH SOUTH OF M-32. PTYPE: STARTS THE DAY ALL SNOW...BUT RAPIDLY WARMING SURFACE LAYER SUGGESTS PREDOMINATE TYPE TO SWITCH TO RAIN COASTAL LOCALES BY LATE MORNING AND ALL AREAS BY AFTERNOON. ONLY CAVEAT TO THIS WILL BE OVER THE INTERIOR HIGH SPOTS WHERE WET BULBS IN THE MID 30S INDICATE A FEW SNOWFLAKES MIGHT MIX IN AT ANY TIME...ESP IF PRECIPITATION RATES ARE DECENT. OVERALL VERY LITTLE IMPACT EXPECTED...HOWEVER... OUTSIDE OF A FEW SLICK SPOTS TO START THE DAY FROM THE BRIDGE NORTH. PAVEMENT TEMPS WILL BE TOO WARM TO SUPPORT ANY ICING BY MID MORNING OVER NORTHERN LOWER. WINDS: PRETTY MUCH FULLY FORCED BY THE STRENGTH OF THE LOW LEVEL JET /40-50KTS AT H9 EARLY...WEAKENING AS IT HEADS SOUTH/ AND THE AMOUNT OF MIXING WE CAN DEVELOP AHEAD OF THE BOUNDARY. GIVEN A SOMEWHAT SLOWER ARRIVAL TO THE BOUNDARY...MIXING HEIGHTS SHOULD GET A CHANCE TO BUILD EARLY...WITH MOMENTUM TRANSPORT SUGGESTING WE CAN LIKELY TAP 30KTS. SO...EXPECT SOUTHWEST WINDS 15-25 MPH WITH GUSTS OVER 30 MPH BY LATE MORNING AND THROUGH THE AFTERNOON OVER NORTHERN LOWER...A LITTLE WEAKER THAN THIS FURTHER NORTH. TEMPS: T9 ROCKETS TO JUST ABOVE FREEZING AHEAD OF THE BOUNDARY... WITH THE POTENTIAL TO PRODUCE LOW-MID 50S AHEAD OF THE BOUNDARY. COMPLICATING THIS WILL BE CLOUDS AND PRECIP...WHICH...WITH PRETTY SUBSTANTIAL LLEVEL DEWPOINT DEPRESSIONS SUGGESTS AMPLE OPPORTUNITY FOR EVAPORATIONAL COOLING. WILL ALLOW SOUTHEASTERN ZONES TO MAKE A RUN AT 55...WITH LOCALES NORTH OF THIS GENERALLY IN THE MID-UPPER 40S. TONIGHT: NORTHWEST WINDS WILL USHER COLDER AIR INTO THE REGION AS HIGH PRESSURE BUILDS IN FROM THE NORTHERN PLAINS. T8 FALLS TO -12C SOUTH/-15C NORTH AFTER MIDNIGHT...WHICH WITH A MINOR AMOUNT OF RESIDUAL 850-700MB MOISTURE SUGGESTS THAT SOME LAKE RESPONSE MAY TRY AND GET GOING...BUT NOT UNTIL THE VERY END OF THIS PERIOD. WILL CARRY CHANCE POPS AFTER 09Z BUT NO SIGNIFICANT SNOWFALL EXPECTED. TEMPERATURES LOOK TO FALL INTO THE MID 20S AS COLD AIR ADVECTION IS OFFSET SOMEWHAT BY RESIDUAL WINDS AND SOME LAKE CLOUDINESS /NORTH/. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 420 AM EDT THU APR 4 2013 FRIDAY...INITIALLY, THERE WILL BE SOME LIGHT SNOW AND FLURRIES IN E UPPER, MAINLY NEAR WHITEFISH POINT AS THE 850 MB TEMPERATURES FALL TO AROUND -14C WITH ABOUT 50% RH IN THE 850-700 MB LAYER. THIS WILL BE MAINLY IN THE MORNING, BECAUSE AS THE HIGH PRESSURE BUILDS INTO THE REGION MORE DRY AIR PUSHES INTO THE FORECAST AREA, AND THE 850 MB TEMPERATURES RISE ABOVE -12C BY 18Z. SO WILL GO WITH A DRY DAY OVERALL. FRIDAY NIGHT...THE WARM ADVECTION WING FROM THE NEXT SYSTEM BEGINS TO MOVE INTO THE REGION, ESPECIALLY AFTER 06Z. THIS WILL BRING A CHANCE OF SNOW BY 12Z IN THE WESTERN PART OF THE FORECAST AREA. THE LOWER LEVEL MOISTURE WILL BE THE MAIN CONCERN AS THE POPS ARE DRAWN ROUGHLY WHERE THE 850 MB MOISTURE IS ABOVE 50%. HOWEVER, THIS COULD JUST AS EASILY BE NOTHING UNTIL THE DAY ON SATURDAY, IF THE ATMOSPHERE DOESN`T SATURATE FAST ENOUGH. SATURDAY...THE WARM FRONT MOVES NORTH A BIT, BUT FOR THE MOISTURE PART ONCE IT GETS TO AROUND THE STRAITS, IT LOOKS LIKE IT TRAVELS EAST, WITH THE SFC LOW FOLLOWING ALONG IT. THIS SETS UP SNOW IN E UPPER, WHICH COULD HAVE LIGHT TO MODERATE AMOUNTS THROUGH THE DAY. WOULD EXPECT A MIX, ESPECIALLY BETWEEN M-32 AND THE STRAITS AS THE PROFILES ARE EITHER ON THE 0C LINE. SOUTH OF M-32, THINK THAT IT WILL BE MAINLY RAIN. OVERNIGHT, THE WARMER AIR WITH BOTH MODELS, GETS TO THE STRAITS, THE RAIN WILL LIKELY GET ALL THE WAY TO THE STRAITS, AND WE`LL GET A MIX IN E UPPER. THE CONCERN, BASED ON THE PROFILES OF BOTH MODELS, IS THAT WE WILL PARTIALLY MELT SOME OF THE SNOW (TEMPERATURES IN THE PROFILE GET TO +2C AROUND 850 MB THEN FALL TO OR BELOW 0C IN E UPPER). SO WILL GO WITH SNOW/RAIN OR FREEZING RAIN MIX AT THIS POINT, AND KEEP IT MENTIONED IN HWOAPX. THE COLD AIR MOVES INTO E UPPER AGAIN ONCE THE LOW MOVES EAST. SO E UPPER WILL SEE A CHANGE OVER AGAIN BETWEEN 06Z AND 12Z. EXTENDED (SUNDAY THROUGH WEDNESDAY)...SUNDAY, THE MODELS MOVE THE LOW EAST OF THE REGION AND THE COLD AIR MOVES BACK. HOWEVER, THINGS ARE DRY ENOUGH AND WARM ENOUGH, THAT LITTLE IF NO PRECIPITATION WILL FALL. MONDAY, LOOKS LIKE ANOTHER WAVE FORMS ON THE FRONT THAT STALLS IT, AND EVEN ALLOWS FOR SOME WARMING. SO WILL GO WITH CHANCE OF RAIN IN N LOWER AND A MIX IN E UPPER. TUESDAY, THE LOW NO LONGER MOVES OUT OF THE MID MISSISSIPPI VALLEY AS THE MODELS FOCUS DEVELOPMENT ON THE CLOSED 500 MB LOW IN THE SOUTHWEST STATES. THIS WOULD KEEP THE SFC LOW IN TX/OK REGION WITH A WARM FRONT/SFC TROUGH THAT IS STALLED IN THE OHIO VALLEY. OVERNIGHT, THE GFS BEGINS TO LIFT THE 500 MB LOW INTO THE NORTHERN BRANCH. THE ECMWF LOOKS BETTER WITH THE SLOWER LIFTING OF THE WAVE KEEPING THE RAIN AND THE WARM FRONT ALONG OR SOUTH OF THE OHIO VALLEY. WEDNESDAY, THINKING THAT THE GFS IS TOO WET, DUE TO THE PHASING OF THE SYSTEMS. WOULD BE MORE INCLINED TO GO WITH THE ECMWF IDEA WITH THE HIGH SETTLING IN OVER THE GREAT LAKES. WHICH WOULD KEEP US DRY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 156 PM EDT THU APR 4 2013 VFR CIGS AND VSBY IN ADVANCE OF A FRONTAL BOUNDARY DROPPING SOUTH ACRS NRN LWR MI...WILL TREND MVFR AND OCCASIONALLY IFR IN MIXED RAIN AND SNOW THROUGH BTWN 00Z AND 03Z. COLDER AIR AND NORTHWEST WINDS ON THE BACK SIDE OF THE EXITING SYSTEM...WILL GENERATE SOME LAKE SNOWS OVER TAF SITE KTVC AND KMBL FRIDAY. GUSTY SOUTHWEST WINDS IN ADVANCE OF THE BOUNDARY...WILL TREND NORTHWEST ACRS NRN LWR MI TAF SITES BTWN 00Z AND 06Z. && .MARINE... ISSUED AT 420 AM EDT THU APR 4 2013 SUMMARY: A COLD FRONT WILL PUSH THROUGH NORTHERN MICHIGAN TODAY WITH GUSTY SOUTHWEST WINDS AHEAD OF IT SHIFTING NORTHWESTERLY BEHIND IT THIS EVENING AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES REGION. HIGH PRESSURE WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH FRIDAY NIGHT. HEADLINES: GALE WARNING THROUGH LATE MORNING STILL LOOKS GOOD OVER PORTIONS OF NORTHERN LAKE MICHIGAN. ELSEWHERE...WILL EXPAND SMALL CRAFTS TO ALL ZONES FOR TODAY GIVEN ROBUST WIND FIELD AHEAD OF APPROACHING COLD FRONT. MARGINAL SMALL CRAFT CONDITIONS CONTINUE THROUGH TONIGHT BEFORE A BREAK IN WIND/WAVE ACTIVITY IS EXPECTED FRIDAY. NEXT STORM SYSTEM ARRIVES SATURDAY WITH A RENEWED PERIOD OF SMALL CRAFTS LIKELY THROUGHOUT THE NEARSHORE WATERS OF NORTHERN MICHIGAN. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LHZ345>349. LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ323-345- 346. GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LMZ341-342-344. LS...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LSZ321-322. && $$ UPDATE...SR SYNOPSIS...JL SHORT TERM...ARNOTT LONG TERM...JL AVIATION...SR MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
113 PM CDT THU APR 4 2013 .UPDATED FOR 18Z TAF DISCUSSION... .UPDATE.../ISSUED 955 AM CDT THU APR 4 2013/ AN UPPER LEVEL LOW PRESSURE SYSTEM CURRENTLY LOCATED OVER THE ARKLATEX REGION WILL TRACK EAST ACROSS NORTH CENTRAL MISSISSIPPI TODAY. LOOKING AT THE LATEST HRRR MODEL...BEST RAIN CHANCES WILL OCCUR FROM EASTERN ARKANSAS TO NORTHWEST TENNESSEE. HAVE ADJUSTED POPS ACCORDINGLY. HAVE ALSO LOWERED HIGHS SLIGHTLY. EXPECT TEMPERATURES TO REMAIN IN THE UPPER 40S FOR HIGHS FOR THE MOST PART DUE TO THE CLOUDS AND RAIN. UPDATE WILL BE OUT SHORTLY. KRM DISCUSSION... /ISSUED 308 AM CDT THU APR 4 2013/ SKIES WERE CLOUDY ACROSS THE MIDSOUTH WITH A FEW AREAS OF LIGHT RAIN ON RADAR. WINDS WERE NORTHEAST AROUND 5 MPH WITH TEMPERATURES HOLDING IN THE MID AND UPPER 40S. ON SATELLITE AN UPPER LEVEL LOW WAS CENTERED IN SOUTHWEST OKLAHOMA WITH LEADING EDGE OF ASSOCIATED ENHANCED CLOUD COVER AND PRECIPITATION ENTERING WESTERN ARKANSAS. FOR TODAY AND TONIGHT...ONE LAST DREARY DAY FOR THE MIDSOUTH IN REGARDS TO RAIN AND UNSEASONABLY COLD TEMPERATURES. FORTUNATELY THE MODELS SHOW THE AFOREMENTIONED LOW BECOMING AN OPEN WAVE...AND BEGINNING TO FILL AS IT PASSES JUST TO OUR SOUTH THIS EVENING. THUS...RAINFALL AMOUNTS WILL LIKELY REMAIN UNDER A QUARTER OF AN INCH FOR MANY MIDSOUTHERNERS. TEMPERATURES WILL STRUGGLE TO REACH 50F ACROSS THE NORTH AND MID 50S SOUTH. AS THE LOW TRACKS INTO ALABAMA AND GEORGIA TONIGHT AN UPPER LEVEL RIDGE OVER THE PLAINS WILL QUICKLY BUILD INTO THE AREA. THIS SHOULD IN TURN ALLOW FOR FASTER CLEARING EARLY FRIDAY MORNING. WITH DRIER AIR WILL PUSHING IN FROM MISSOURI TEMPERATURES WILL EASILY CLIMB INTO THE MID 60S. THE REAL START TO THE MIDSOUTH WARMING TREND HOWEVER WILL BEGIN ON SATURDAY AS LOW LEVEL WINDS TURN SOUTHERLY. SKIES THOUGH...MAY BECOME PARTLY SUNNY THROUGHOUT THE DAY AS MODEL CROSS SECTIONS YIELD THICKENING CIRRUS CLOUDS EXTENDING WELL EAST OF THE ROCKIES. TEMPERATURES SHOULD STILL MANAGE TO MAKE IT INTO THE LOW AND MID 70S. GULF MOISTURE WILL BEGIN TO SURGE NORTHWARD SATURDAY NIGHT AND SUNDAY AS A COLD FRONT BECOMES STALLED ACROSS THE CORN BELT AND CENTRAL PLAINS. WAA WILL CONTINUE ON SUNDAY DEVELOPING A DEEP LAYER CAP BETWEEN 850 AND 700MB. THUS ANY ISOLATED CONVECTION FORMING WEST OF THE MISSISSIPPI RIVER WILL EITHER WAA SHOWERS OR ELEVATED THUNDER. HIGHS ON SUNDAY WILL REMAIN IN THE 70S WITH MILDER LOWS IN THE MID AND UPPER 50S. MONDAY THROUGH WEDNESDAY NIGHT...THIS PERIOD WILL SEE AN INCREASE THREAT FOR STORMS AND SEVERE WEATHER AS A NEW STORM DEEPENS OVER THE CENTRAL ROCKIES. THE UPPER FLOW OVER THE MIDSOUTH WILL BACK FROM THE SOUTHWEST WITH SPEEDS INCREASING. THE COMBINATION OF MINOR WAVES IN THE FLOW RIDING OVER THE STALLED BOUNDARY TO OUR NORTH AND DEWPOINTS INCREASING TO THE MID AND UPPER 60S...WILL WEAKEN THE ESTABLISHED CAP ALLOWING FOR SFC BASED CONVECTION. THE GFS AND EURO BOTH SPORT 1500+ J/KG OF CAPE...7.0C+ LAPSE RATES...AND LIFTED INDICES OF NEAR -6C. THE GFS ALSO IS INDICATING 0-1KM HELICITY VALUES IN EXCESS OF 3.0 M^2/S^2 INDICATING ROTATING STORMS. SINCE MODEL RUNS OVER THE PAST THREE DAYS HAVE BEEN CONSISTENT IN THE THREAT FOR SEVERE WEATHER FOR TUESDAY...WILL INTRODUCE THIS THREAT IN THE UPCOMING HWO. DEPENDENT ON AMOUNT OF CUMULUS CLOUD COVER/CONVECTION...DAYTIME HIGHS COULD WARM CLOSE TO 80F. SOUTH WINDS WILL ALSO INCREASE AND GUST TO 30MPH ON TUESDAY AS A SURFACE WAVE DEEPENS IN WEST TEXAS. THIS FEATURE IS PROGGED TO MOVE INTO THE OZARKS ON WEDNESDAY AND MAY PROVIDE A SECOND DAY THREAT FOR SEVERE WEATHER OVER OUR AREA. JAB && .AVIATION... LOW CEILINGS IN RA/DZ/BR WILL CONTINUE TO PLAGUE THE MIDSOUTH AIRPORTS THROUGH TONIGHT. GIVEN THE STUBBORN NATURE OF THIS UPPER LOW AND PERSISTENT MOISTURE...HAVE OPTED TO KEEP LOW CEILINGS THROUGH 06Z AT KMEM...WITH EARLIER CLEARING AT KJBR. AFTER 06Z THE UPPER LOW WILL SHIFT EAST OF THE REGION...ALLOWING SKIES TO GRADUALLY CLEAR THROUGH 12Z TOMORROW. SAK && .PRELIMINARY POINT TEMPS/POPS... MEM 48 42 66 49 / 80 40 0 0 MKL 48 39 65 43 / 80 50 0 0 JBR 49 39 66 44 / 80 30 0 0 TUP 49 43 65 43 / 60 50 10 0 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$