Forecast Discussions mentioning any of "HRRR" "RR" "RUC13" "RUC" received at GSD on 03/26/12


SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
1040 AM PDT SAT MAR 24 2012 ...UPDATED AVIATION DISCUSSION... .SYNOPSIS... A COLD LOW WILL MOVE SOUTH OVER THE REGION TONIGHT THROUGH SUNDAY NIGHT AND FURTHER COOL TEMPERATURES. PRECIPITATION WILL BEGIN IN SAN LUIS OBISPO AND SANTA BARBARA COUNTIES BY TONIGHT. ON SUNDAY...RAIN...HEAVY AT TIMES...WITH A SLIGHT CHANCE OF THUNDERSTORMS WILL AFFECT THE ENTIRE AREA. THE LOW WILL MOVE EAST ON MONDAY FOR FAIR WEATHER. ANOTHER LOW WILL APPROACH BY MIDWEEK FOR POSSIBLE PRECIPITATION IN SAN LUIS OBISPO AND SANTA BARBARA COUNTIES. THE TEMPERATURES WILL BE BACK TO SEASONAL NORMALS ON THURSDAY. && .SHORT TERM (TODAY-MON)...HAVE ISSUED AN UPDATE THIS MORNING TO INCLUDE A SLIGHT CHANCE OF LIGHT RAIN ALONG THE NORTHERN HALF OF THE CENTRAL COAST AND ADJUSTED POPS UP IN THE EVENING OVER THE ENTIRE AREA. COMPLEX LOW OVER THE EASTERN PACIFIC AND TROUGH AXIS WAS INITIALIZED APPROXIMATELY 400 MILES WEST OF NORTHERN CALIFORNIA THIS MORNING. AND PICTURES FROM SPACE HAD INDICATED 180 MILE WIDE CLOUD BAND WITHIN THE FRONTAL BOUNDARY WITH THE LEADING EDGE OVER THE MONTEREY/SAN LUIS OBISPO COUNTY BORDER. LATEST RUC INDICATED DECREASING MID LEVEL STABILITY AND INCREASING UPPER LEVEL DEFORMATION AND MID LEVEL ASCENDING FLOW OVER THE CENTRAL COAST THIS AFTERNOON AND THERE IS A SLIGHT CHANCE LIGHT RAIN WILL BEGIN IN THE AFTERNOON. THE AREA OF INSTABILITY AND DEFORMATION WILL NUDGE SOUTHEAST AND RAIN WILL LIKELY BEGIN AS FAR SOUTH AS THE WESTERN HALF OF VENTURA COUNTY LATE IN THE EVENING. THE FOLLOWING IS AN EXCERPT FROM THE PREVIOUS DISCUSSION CLOSER TO HOME...A 2100 FOOT MARINE LAYER HAS ALLOWED LOW CLOUDS TO FORM. THE CLOUDS HAVE BEEN EXPANDING OVERNIGHT AND NOW COVER MOST OF THE COAST SOUTH OF POINT CONCEPTION AND WILL LIKELY COVER THE L.A. VLYS BY DAWN. SOME LOW CLOUDS ARE FORMING NORTH OF POINT CONCEPTION DUE TO SOME WEAK LIFT PROVIDED BY A LITTLE ATMOSPHERIC RIPPLE MOVING ACROSS THE AREA. THE LOW CLOUDS WILL SLOWLY BURN OFF THIS MORNING AND BY AFTERNOON THEY SHOULD BE MOSTLY GONE BUT SKIES WILL THEN BE PARTLY CLOUDY AS CLOUDS AHEAD OF SUNDAYS STORM STREAM IN. THERE IS A CHANCE THAT SOME LIGHT RAIN WILL ARRIVE NORTH OF MORRO BAY LATER THIS AFTERNOON BUT MORE LIKELY THAN NOT THE RAIN WILL HOLD OFF UNTIL THIS EVENING. TEMPS WILL BE SIMILAR TO FRIDAYS...IN THE MID TO UPPER 60S ACROSS MOST NON MOUNTAIN AREAS. SUNDAY WILL BE WET. RAIN WILL OVERSPREAD THE AREA DURING THE MORNING. RAINFALL WILL BE HEAVY AT TIMES (EARLY IN THE MORNING SLO AND SBA COUNTIES...MID MORNING TO EARLY AFTERNOON VTA COUNTY...AND DURING THE AFTERNOON L.A. COUNTY) RAIN WILL TURN TO SHOWERS BEHIND THE FRONT STARTING OVER SLO COUNTY LATE IN THE MORNING ACROSS SLO COUNTY WORKING ITS WAY DOWN TO L.A. COUNTY BY LATE AFTERNOON. GOOD JET DYNAMICS...MID LEVEL POSITIVE VORTICITY ADVECTION...AND FALLING 500 MB TEMPS WILL COMBINE TO PRODUCE A SLIGHT CHC OF TSTMS ACROSS THE AREA. THERE IS A GENEROUS AMOUNT OF HELICITY WITH THIS SYSTEM AND THERE WILL MORE THAN LIKELY BE A NUMBER OF WATERSPOUTS DURING THE AFTERNOON. THE NAM HAS THE COLD CORE OF THE LOW MOVING DIRECTLY OVER SBA COUNTY LATE IN THE AFTERNOON AND THIS IF CORRECT COULD BE THE BEST CHC FOR TSTMS. SNOW LEVELS WILL START OFF BETWEEN 6500 AND 7500 FEET THIS EVENING WILL THEN FALL TO BETWEEN 5000 AND 5500 FEET BY EARLY SUNDAY MORNING. THE SNOW LEVEL WILL LOWER LOCALLY TO 4500 FEET BY SUNDAY NIGHT. EXPECTED RAINFALL AMOUNTS RANGE FROM .75 TO 1.5 INCHES FOR COAST AND VALLEYS...WHILE FOOTHILL AND MOUNTAIN AREAS SHOULD SEE 2-4 INCHES. SNOW ACCUMULATIONS BETWEEN 8 AND 14 INCHES ARE LIKELY ABOVE 5500 FEET...WITH LOCAL AMOUNTS UP TO 16 INCHES IN FAVORABLE LOCATIONS ABOVE 7000 FEET. WINTER STORM WARNINGS HAVE BEEN ISSUED FOR THE VTA AND LA MTNS WITH THE VTA WARNING STARTING LATE TONIGHT AND THE LA WARNING STARTING MID MORNING SUNDAY. THE 06Z NAM THROWS A FLY INTO THE OINTMENT. IT DEVELOPS A BROAD EASTERLY FLOW ACROSS THE AREA. THIS DRYING OFFSHORE FLOW WILL...IF TRUE...WILL SEVERELY LIMIT THE RAINFALL. THIS IS THE OUTLIER FORECAST BUT IT HAS HAPPENED BEFORE AND NEEDS TO WATCHED. THIS STORM WILL NOT BE A COLD NOR A WINDY AS LAST WEEKS. HIGHS WILL BE IN THE UPPER 50S FOR MOST AREAS AS OPPOSED TO LOW 50S LAST WEEK. WIND ADVISORIES MAY BE NEEDED FOR THE MTNS OF SLO AND SBA COUNTY BUT THE LOWER ELEVATIONS SHOULD ONLY SEE NON ADVISORY WINDS 15 TO 25 MPH. THE STORM WILL MOVE OUT LATE SUNDAY NIGHT AND WHILE THERE WILL BE A CHANCE OF SOME MORNING SHOWERS MONDAY MORNING ACROSS L.A. COUNTY THE DAY WILL MOSTLY BE DRY AND COOL. .LONG TERM (TUE-FRI)... UN-EXCITING WEATHER RETURNS FOR THE EXTENDED PERIOD. FLAT SOUTHWEST FLOW WILL BRING PARTLY CLOUDY SKIES TO THE AREA TUESDAY TEMPS WILL RISE A DEGREE OR TWO BUT WILL REMAIN BELOW NORMAL. THE TAIL END OF A WEAK COLD FRONT WILL MOVE OVER THE CENTRAL COAST WEDNESDAY. IT WILL BE GOOD FOR A CHANCE OF RAIN. IT WILL BRING CLOUDS TO THE ENTIRE AREA AND A DEGREE OR SO OF COOLING. RAINFALL IF ANY WILL BE UNDER A QUARTER INCH. SOUTHWEST FLOW AND RISING HGTS WILL MAKE THURSDAY THE NICEST OF THE NEXT 7 WITH NEAR NORMAL TEMPS AND MOSTLY CLEAT SKIES. THE FLOW TURNS WESTERLY FRIDAY AS A GULF OF ALASKA STORM MOVES SLIGHTLY SOUTHWARD. SKIES WILL TURN PARTLY CLOUDY AND MAX TEMPS WILL DROP A COUPLE OF DEGREES. && .AVIATION...24/1740Z... MVFR CIGS GRADUALLY DISSIPATING SOUTH OF POINT CONCEPTION THIS MORNING...WITH VFR CONDS EXPECTED THIS AFTERNOON AND EVENING. NORTH OF POINT CONCEPTION...SKIES ARE CURRENTLY CLEAR...BUT CLOUDS WILL BE ON THE INCREASE THIS AFTERNOON AS FRONT APPROACHES. OVERNIGHT AND SUNDAY MORNING...COLD FRONT WILL BEGIN TO MOVE ACROSS THE AREA...BRINGING MVFR/IFR CONDS TO ALL TAF SITES WITH MODERATE RAINFALL. CONFIDENCE IN TIMING OF STEADY RAINFALL IS LOW WITH THE 18Z TAF PACKAGE. KLAX...MODERATE CONFIDENCE IN 18Z TAF. HIGH CONFIDENCE IN VFR CONDS THIS AFTERNOON AND EVENING. LOW CONFIDENCE IN TIMING OF THE ARRIVAL OF MVFR DECK AND ASSOCIATED RAINFALL TONIGHT. KBUR...MODERATE CONFIDENCE IN 18Z TAF. HIGH CONFIDENCE IN VFR CONDS THIS AFTERNOON AND EVENING. LOW CONFIDENCE IN TIMING OF THE ARRIVAL OF MVFR DECK AND ASSOCIATED RAINFALL TONIGHT. && .LOX WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING (SEE LAXWSWLOX). SMALL CRAFT ADVISORY (SEE LAXMWWLOX). SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX). && $$ PUBLIC...RORKE AVIATION...RAT SYNOPSIS...B WWW.WEATHER.GOV/LOSANGELES
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
945 AM PDT SAT MAR 24 2012 .SYNOPSIS... A COLD LOW WILL MOVE SOUTH OVER THE REGION TONIGHT THROUGH SUNDAY NIGHT AND FURTHER COOL TEMPERATURES. PRECIPITATION WILL BEGIN IN SAN LUIS OBISPO AND SANTA BARBARA COUNTIES BY TONIGHT. ON SUNDAY...RAIN...HEAVY AT TIMES...WITH A SLIGHT CHANCE OF THUNDERSTORMS WILL AFFECT THE ENTIRE AREA. THE LOW WILL MOVE EAST ON MONDAY FOR FAIR WEATHER. ANOTHER LOW WILL APPROACH BY MIDWEEK FOR POSSIBLE PRECIPITATION IN SAN LUIS OBISPO AND SANTA BARBARA COUNTIES. THE TEMPERATURES WILL BE BACK TO SEASONAL NORMALS ON THURSDAY. && .SHORT TERM (TODAY-MON)...HAVE ISSUED AN UPDATE THIS MORNING TO INCLUDE A SLIGHT CHANCE OF LIGHT RAIN ALONG THE NORTHERN HALF OF THE CENTRAL COAST AND ADJUSTED POPS UP IN THE EVENING OVER THE ENTIRE AREA. COMPLEX LOW OVER THE EASTERN PACIFIC AND TROUGH AXIS WAS INITIALIZED APPROXIMATELY 400 MILES WEST OF NORTHERN CALIFORNIA THIS MORNING. AND PICTURES FROM SPACE HAD INDICATED 180 MILE WIDE CLOUD BAND WITHIN THE FRONTAL BOUNDAY WITH THE LEADING EDGE OVER THE MONTEREY/SAN LUIS OBISPO COUNTY BORDER. LATEST RUC INDICATED DECREASING MID LEVEL STABILITY AND INCREASING UPPER LEVEL DEFORMATION AND MID LEVEL ASCENDING FLOW OVER THE CENTRAL COAST THIS AFTERNOON AND THERE IS A SLIGHT CHANCE LIGHT RAIN WILL BEGIN IN THE AFTEROON. THE AREA OF INSTABILITY AND DEFORMATION WILL NUDGE SOUTHEAST AND RAIN WILL LIKELY BEGIN AS FAR SOUTH AS THE WESTERN HALF OF VENTURA COUNTY LATE IN THE EVENING. THE FOLLOWING IS AN EXCERPT FROM THE PREVIOUS DISCUSSION CLOSER TO HOME...A 2100 FOOT MARINE LAYER HAS ALLOWED LOW CLOUDS TO FORM. THE CLOUDS HAVE BEEN EXPANDING OVERNIGHT AND NOW COVER MOST OF THE COAST SOUTH OF POINT CONCEPTION AND WILL LIKELY COVER THE L.A. VLYS BY DAWN. SOME LOW CLOUDS ARE FORMING NORTH OF POINT CONCEPTION DUE TO SOME WEAK LIFT PROVIDED BY A LITTLE ATMOSPHERIC RIPPLE MOVING ACROSS THE AREA. THE LOW CLOUDS WILL SLOWLY BURN OFF THIS MORNING AND BY AFTERNOON THEY SHOULD BE MOSTLY GONE BUT SKIES WILL THEN BE PARTLY CLOUDY AS CLOUDS AHEAD OF SUNDAYS STORM STREAM IN. THERE IS A CHANCE THAT SOME LIGHT RAIN WILL ARRIVE NORTH OF MORRO BAY LATER THIS AFTERNOON BUT MORE LIKELY THAN NOT THE RAIN WILL HOLD OFF UNTIL THIS EVENING. TEMPS WILL BE SIMILAR TO FRIDAYS...IN THE MID TO UPPER 60S ACROSS MOST NON MOUNTAIN AREAS. SUNDAY WILL BE WET. RAIN WILL OVERSPREAD THE AREA DURING THE MORNING. RAINFALL WILL BE HEAVY AT TIMES (EARLY IN THE MORNING SLO AND SBA COUNTIES...MID MORNING TO EARLY AFTERNOON VTA COUNTY...AND DURING THE AFTERNOON L.A. COUNTY) RAIN WILL TURN TO SHOWERS BEHIND THE FRONT STARTING OVER SLO COUNTY LATE IN THE MORNING ACROSS SLO COUNTY WORKING ITS WAY DOWN TO L.A. COUNTY BY LATE AFTERNOON. GOOD JET DYNAMICS...MID LEVEL POSITIVE VORTICITY ADVECTION...AND FALLING 500 MB TEMPS WILL COMBINE TO PRODUCE A SLIGHT CHC OF TSTMS ACROSS THE AREA. THERE IS A GENEROUS AMOUNT OF HELICITY WITH THIS SYSTEM AND THERE WILL MORE THAN LIKELY BE A NUMBER OF WATERSPOUTS DURING THE AFTERNOON. THE NAM HAS THE COLD CORE OF THE LOW MOVING DIRECTLY OVER SBA COUNTY LATE IN THE AFTERNOON AND THIS IF CORRECT COULD BE THE BEST CHC FOR TSTMS. SNOW LEVELS WILL START OFF BETWEEN 6500 AND 7500 FEET THIS EVENING WILL THEN FALL TO BETWEEN 5000 AND 5500 FEET BY EARLY SUNDAY MORNING. THE SNOW LEVEL WILL LOWER LOCALLY TO 4500 FEET BY SUNDAY NIGHT. EXPECTED RAINFALL AMOUNTS RANGE FROM .75 TO 1.5 INCHES FOR COAST AND VALLEYS...WHILE FOOTHILL AND MOUNTAIN AREAS SHOULD SEE 2-4 INCHES. SNOW ACCUMULATIONS BETWEEN 8 AND 14 INCHES ARE LIKELY ABOVE 5500 FEET...WITH LOCAL AMOUNTS UP TO 16 INCHES IN FAVORABLE LOCATIONS ABOVE 7000 FEET. WINTER STORM WARNINGS HAVE BEEN ISSUED FOR THE VTA AND LA MTNS WITH THE VTA WARNING STARTING LATE TONIGHT AND THE LA WARNING STARTING MID MORNING SUNDAY. THE 06Z NAM THROWS A FLY INTO THE OINTMENT. IT DEVELOPS A BROAD EASTERLY FLOW ACROSS THE AREA. THIS DRYING OFFSHORE FLOW WILL...IF TRUE...WILL SEVERELY LIMIT THE RAINFALL. THIS IS THE OUTLIER FORECAST BUT IT HAS HAPPENED BEFORE AND NEEDS TO WATCHED. THIS STORM WILL NOT BE A COLD NOR A WINDY AS LAST WEEKS. HIGHS WILL BE IN THE UPPER 50S FOR MOST AREAS AS OPPOSED TO LOW 50S LAST WEEK. WIND ADVISORIES MAY BE NEEDED FOR THE MTNS OF SLO AND SBA COUNTY BUT THE LOWER ELEVATIONS SHOULD ONLY SEE NON ADVISORY WINDS 15 TO 25 MPH. THE STORM WILL MOVE OUT LATE SUNDAY NIGHT AND WHILE THERE WILL BE A CHANCE OF SOME MORNING SHOWERS MONDAY MORNING ACROSS L.A. COUNTY THE DAY WILL MOSTLY BE DRY AND COOL. .LONG TERM (TUE-FRI)... UN-EXCITING WEATHER RETURNS FOR THE EXTENDED PERIOD. FLAT SOUTHWEST FLOW WILL BRING PARTLY CLOUDY SKIES TO THE AREA TUESDAY TEMPS WILL RISE A DEGREE OR TWO BUT WILL REMAIN BELOW NORMAL. THE TAIL END OF A WEAK COLD FRONT WILL MOVE OVER THE CENTRAL COAST WEDNESDAY. IT WILL BE GOOD FOR A CHANCE OF RAIN. IT WILL BRING CLOUDS TO THE ENTIRE AREA AND A DEGREE OR SO OF COOLING. RAINFALL IF ANY WILL BE UNDER A QUARTER INCH. SOUTHWEST FLOW AND RISING HGTS WILL MAKE THURSDAY THE NICEST OF THE NEXT 7 WITH NEAR NORMAL TEMPS AND MOSTLY CLEAT SKIES. THE FLOW TURNS WESTERLY FRIDAY AS A GULF OF ALASKA STORM MOVES SLIGHTLY SOUTHWARD. SKIES WILL TURN PARTLY CLOUDY AND MAX TEMPS WILL DROP A COUPLE OF DEGREES. && .AVIATION...24/1140Z N OF POINT CONCEPTION...LOW CONFIDENCE WITH STRATUS IN RESPECT TO BURNOFF TIME. HIGHER CONFIDENCE WITH TIMING OF PRECIPITATION OVERNIGHT. RAIN SHOULD DEVELOP AROUND 08Z-10Z TONIGHT INTO EARLY SUNDAY MORNING. GUSTY SOUTHERLY WINDS AHEAD OF THE FRONT. SLIGHT CHANCE OF THUNDERSTORMS BY SUNDAY MORNING. S OF POINT CONCEPTION...MODERATE CONFIDENCE WITH 12Z TAF. MVFR CIGS WILL GIVE WAY T VFR CIGS BY THIS AFTERNOON. 30 PERCENT CHANCE FOR MVFR CIGS TO STICK AROUND UNTIL NOON. INCREASING HIGH CLOUDS WILL PREVAIL LATER THIS AFTERNOON. NO RAIN EXPECTED FOR AREAS S OF POINT CONCEPTION UNTIL AROUND 12Z SUNDAY THROUGH 18Z. THEN RAIN SHOULD SPREAD EVERYWHERE BY SUNDAY AFTERNOON. GUSTY SOUTHERLY WINDS ARE EXPECTED THROUGH MUCH OF THE DAY. Z LEVEL SHOULD BE AROUND 5.6KFT BY SUNDAY AFTERNOON. KLAX...MODERATE CONFIDENCE WITH 12Z TAF. MVFR CIGS SHOULD GIVE WAY TO VFR CIGS BY 18-21Z TODAY. WITH INCREASING HIGH CLOUDS LATER IN THE DAY. SEA BREEZE WILL KICK IN BY 19-21Z. CLOUDS WILL BE INCREASING BY SUNDAY MORNING...AND RAIN SHOULD BEGIN BY SUNDAY 18-20Z AND PERSIST THROUGH MUCH OF SUNDAY EVENING INTO THE OVERNIGHT HOURS. WINDS SHOULD STAY OF THE SE ON SUNDAY MORNING...AND PERSIST IN THAT DIRECTION THROUGH MUCH OF THE DAY. WINDS SHIFTING BY SUNDAY EVENING TO SW. KBUR...MODERATE CONFIDENCE WITH 12Z TAF. LOW MVFR CIGS WILL CONTINUE THROUGH 18Z THEN VFR CIGS WITH HIGH CLOUDS INCREASING THROUGH THE DAY. SIMILAR TIMING OF SHOWERS AS KLAX BY SUNDAY LATE MORNING INTO EARLY AFTERNOON. WINDS SHOULD REMAIN E TO SE MOST OF SUNDAY. && .LOX WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING (SEE LAXWSWLOX). SMALL CRAFT ADVISORY (SEE LAXMWWLOX). SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX). && $$ PUBLIC...RORKE AVIATION...KAPLAN SYNOPSIS...B WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
659 PM EDT SAT MAR 24 2012 .SYNOPSIS... LOW PRESSURE WILL TRACK SOUTH OF US AND MOVE OFF THE COAST SUNDAY EVENING. A COLD FRONT WILL MOVE THROUGH THE AREA DURING THE DAY ON MONDAY. HIGH PRESSURE WILL THEN ARRIVE FOR TUESDAY AND PERSIST THROUGH EARLY WEDNESDAY. A WARM FRONT IS FORECAST TO LIFT NORTHEASTWARD TOWARD THE REGION LATE ON WEDNESDAY. ANOTHER COLD FRONT, MOVING IN FROM THE WEST, SHOULD WORK ITS WAY THROUGH THE AREA ON WEDNESDAY NIGHT. MORE HIGH PRESSURE IS FORECAST FOR THURSDAY, FRIDAY, AND POSSIBLY SATURDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... THE UPPER LOW ACROSS THE OHIO VALLEY WILL MOVE EWRD TONIGHT INTO THE CAROLINAS. A SFC LOW WILL MOVE A LITTLE AHEAD OF THE UPPER LOW AND CAUSE A FRONTAL SYSTEM TO APPROACH THE AREA TONIGHT. THE REGIONAL RADARS ARE SHOWING SHOWERS APPROACHING FROM THE SW ATTM. THESE SHOWERS WILL BE ACROSS THE AREA EARLY TONIGHT ALONG WITH AREAS OF FOG WHICH SHOULD DEVELOP TOO. THE FOG WILL PROBABLY BE MORE ABUNDANT NEAR THE SHORE...BUT WAS INCLUDED IN ALL AREAS WITH THIS FCST. RAINFALL TOTALS WILL BE AROUND A TENTH TO ONE QUARTER INCH. LOW TEMPERATURES WILL RANGE FROM THE LOW OR MID 50S ACROSS THE DELMARVA TO THE LOW/MID 40S ACROSS THE NRN AREAS. WINDS WILL BE ERLY AT 5 TO 10 MPH. BASED ON LATEST RADAR TRENDS, HAVE LOWERED POPS FOR NEXT FEW HOURS. HRRR DATA INDICATES AN INCREASE IN PRECIP AGAIN AFTER 02 OR 03Z, SO DIDN`T MAKE CHANGES AFTER THAT. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... SLOW IMPROVEMENT IN THE WEATHER FOR SUNDAY. THE LOW PRESSURE SYSTEM WILL BE OFFSHORE AND MOVING TO THE NORTHEAST. IT WILL SLOWLY STRENGTHEN AND BRING MORE OF A NERLY THEN NRLY WINDS ACROSS THE AREA. WHILE CLOUDS ARE EXPECTED MUCH OF THE DAY...A GRADUAL IMPROVEMENT SHOULD OCCUR LATE. A FEW LINGERING SHOWERS ARE POSSIBLE SOUTH AND EAST MOSTLY DURING THE MORNING. HIGHS ON SUN WILL BE SOMEWHAT DEPENDENT ON HOW MUCH SUN BREAK OUT LATE IN THE DAY...I HAVE GONE MOSTLY MID TO UPPER 60S ATTM WITH UPPER 50S ACROSS THE SRN POCONOS...THIS IS A FEW DEGREES LOWER THAN WHAT THE GUIDANCE TEMPS HAVE. WINDS WILL BE MOSTLY LIGHT ON SUNDAY...MOSTLY NE OR N AT 5 TO 10 MPH. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... THE MID-LEVEL LOW AXIS IS FORECAST TO SHIFT OFF THE COAST SUNDAY NIGHT BRINGING AN END TO THE SHOWER THREAT. WHILE A DRY COLD FRONT ON MONDAY WON`T BRING ANY RAIN TO THE REGION, IT WILL PROVIDE A CHANGE IN AIRMASS. WITH IT`S STRONG CAA AND GUSTY WINDS, MARCH 26TH WILL ACTUALLY FEEL LIKE MARCH 26TH, NOT APRIL OR MAY 26TH. A SURFACE HIGH, CENTERED ACROSS ONTARIO, MONDAY NIGHT WILL BEGIN TO SAG INTO THE REGION BRINGING WITH IT A LITTLE LESS GRADIENT. THE HIGH WILL BE ON TOP OF US ON TUESDAY AND WILL MOVE TO THE COAST ON TUESDAY NIGHT. LOOKS LIKE A WARM FRONT IS GOING TO APPROACH US FROM THE SOUTH ON WEDNESDAY, BUT STRUGGLE TO MOVE THROUGH. WHAT`S MORE CERTAIN IS THE COLD FRONT, COMING IN FROM THE WEST, THAT WILL CROSS THE REGION ON WEDNESDAY NIGHT. HIGH PRESSURE IS FORECAST TO BUILD IN BEHIND THIS FRONT AND PERSIST INTO FRIDAY AND MAYBE EVEN SATURDAY. NO HEAVY PRECIPITATION IS EXPECTED THROUGH THIS PERIOD. SHOWERS WILL BE CARRIED SUNDAY NIGHT, AT LEAST EARLY, AND AGAIN ON WEDNESDAY INTO THURSDAY WITH THE MIDWEEK COLD FRONT. AS FOR TEMPERATURES, NOT MUCH CHANGE FROM YESTERDAY. WE`LL SEE MORE CHANGEABLE CONDITIONS, SYNONYMOUS OF SPRING. MONDAY SHOULD BE ABOVE NORMAL (ALTHOUGH THE NAM MOS SAYS OTHERWISE), TUESDAY AROUND NORMAL, WEDNESDAY/THURSDAY ABOVE NORMAL, AND BACK TO NEAR NORMAL FRIDAY/SATURDAY. THE REGION WILL SEE SOME 30S NEXT WEEK IN THE MORNING. THE COLDEST MORNING STILL LOOKS TO BE TUESDAY WHERE WE SHOULD SEE SUB-FREEZING TEMPERATURES. NOT A GOOD THING FOR SENSITIVE VEGETATION/TREES THAT HAVE GOTTEN OFF TO A TWO TO FOUR WEEK HEAD START THANKS TO WHAT COULD AMOUNT TO A TOP 3 MARCH TEMP-WISE. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... CONDITIONS WERE MAINLY VFR AND MVFR ERLY THIS EVENING. LATEST GUIDANCE CONTINUED TO INDICATE DETERIORATION WILL BEGIN LATER THIS EVENING AS ANOTHER AREA OF SHOWERS AND DEEPER MOISTURE ARRIVE...WITH FLYING CONDITIONS EXPECTED TO GO IFR IN MOST AREAS BY MIDNIGHT. HOWEVER, LATEST TRENDS IMPLY THAT THE DETERIORATION MAY START A BIT LATER THAN EARLIER FCST. ONLY SLOW IMPROVEMENT WILL OCCUR SUNDAY MORNING...SINCE THE SFC/UPPER LOW MOVING ACROSS THE AREA WILL NOT BE MOVING THAT FAST. BETTER CONDITIONS WILL ARRIVE LATER SUNDAY...ONCE THE SYSTEM MOVES AWAY AND SFC WINDS TURN MORE TOWARD THE N OR NW. OUTLOOK... SUNDAY NIGHT...VFR. MONDAY...VFR WITH A GUSTY NORTHWEST WIND. MONDAY NIGHT THROUGH TUESDAY NIGHT...VFR. WEDNESDAY...MAINLY VFR. BUT A CHANCE OF SHOWERS WITH THE COLD FRONT. THURSDAY...MAINLY VFR WITH SOME REMNANT POST FRONT SHOWERS POSSIBLE. && .MARINE... EAST WINDS HAVE REMAINED AROUND 10 TO 15 KTS ON THE WATERS TODAY...THE DEVELOPING SFC LOW TO THE SOUTH SHOULD KEEP WINDS MOSTLY ERLY TONIGHT. A SCA FLAG WILL PROBABLY NOT BE NEEDED TONIGHT...BUT SEAS MAY GET CLOSE TO 5 FT...WE MAY HAVE TO ISSUE SCA IF THE SEAS GET OVER 5 FT. LOW CONFID IN THIS ATTM. WINDS WILL SLACKEN SUN MORNING AS THE SFC PRESSURE TROUGH CROSSES THE WATERS. WINDS WILL SLOWLY VEER NERLY THEN NRLY ON SUNDAY. AREAS OF SHOWERS AND FOG WILL BE ON THE WATERS TONIGHT AND SUN MORNING. OUTLOOK... A STRONG COLD FRONT, FROM THE NORTHWEST, IS EXPECTED TO CROSS THE COASTAL WATERS OF NEW JERSEY AND DELAWARE ON MONDAY. HIGH PRESSURE WILL FOLLOW AND PERSIST THROUGH LATE TUESDAY. A WARM FRONT IS ANTICIPATED TO APPROACH FROM THE SOUTHWEST ON WEDNESDAY FOLLOWED BY A COLD FRONT ON WEDNESDAY NIGHT. A SMALL CRAFT ADVISORY MAY BE NEEDED FROM MONDAY INTO TUESDAY MORNING FOR THE GUSTY NORTHWEST WINDS IN THE COLD ADVECTION. ISOLATED GALE FORCE GUSTS MAY OCCUR FROM LATE MONDAY INTO MONDAY NIGHT. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...KRUZDLO NEAR TERM...NIERENBERG/O`HARA SHORT TERM...O`HARA LONG TERM...KRUZDLO AVIATION...KRUZDLO/NIERENBERG/O`HARA MARINE...KRUZDLO/O`HARA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
553 AM EDT SAT MAR 24 2012 .SYNOPSIS... LOW PRESSURE LOCATED OVER THE OHIO RIVER VALLEY EARLY THIS MORNING WILL PROGRESS EASTWARD AND IT SHOULD MOVE OFF THE MIDDLE ATLANTIC COAST ON SUNDAY. A COLD FRONT FROM THE NORTHWEST IS FORECAST TO PASS THROUGH OUR REGION EARLY ON MONDAY, FOLLOWED BY HIGH PRESSURE FOR TUESDAY. A WARM FRONT APPROACHING FROM THE SOUTHWEST IS EXPECTED TO ARRIVE ON WEDNESDAY, WITH A COLD FRONT FROM THE WEST ANTICIPATED FOR WEDNESDAY NIGHT. HIGH PRESSURE SHOULD BUILD INTO OUR REGION FROM THE NORTHWEST FOR THURSDAY AND FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A FEW UPDATES WERE NEEDED TO ADJUST THE POPS UPWARD SOME ESPECIALLY ACROSS THE SOUTHERN ZONES. THERE IS A BAND OF SHOWERS AND EVEN SOME THUNDERSTORMS SLIDING THEIR WAY NORTHWARD. MOST OF THIS APPEARS TO BE NORTH OF THE STALLED FRONTAL BOUNDARY, WITH THE INITIATION MOSTLY DRIVEN BY INCREASING WAA ABOVE THE LOWER STABLE LAYER ALONG WITH SOME PVA ARRIVING. A LAPS SOUNDING NEAR KSBY INDICATED ABOUT 500 J/KG OF INSTABILITY, BUT THIS IS ALL ELEVATED. THE RADAR IMAGERY SHOWS THAT THE CELLS ARE NOT ALL THAT TALL, BUT ENOUGH VERTICAL EXTENT TO GENERATE SOME CHARGE SEPARATION. THE HRRR PICKED UP ON THIS ACTIVITY ALTHOUGH THE PLACEMENT IS OFF A BIT. THIS MODEL BRINGS THE ACTIVITY INTO PORTIONS OF SOUTHEASTERN PENNSYLVANIA AND FAR SOUTHERN NEW JERSEY BEFORE WEAKENING IT. THERE IS MOSTLY A BREAK BEHIND IT, THEN THE MAIN BAND OF SHOWERS IS FARTHER TO THE SOUTHWEST. THE AFOREMENTIONED LAPS SOUNDING ALSO HAD A STORM MOTION OF ONLY 10 MPH. OTHERWISE, AFTER WIDESPREAD RECORD WARMTH YESTERDAY, UNSETTLED WEATHER WILL BE MOVING INTO THE AREA AS WE GO THROUGH TODAY. OUR REGION CAN ACTUALLY USE SOME RAIN. A SOMEWHAT CHALLENGING FORECAST TODAY AS THE LARGE CLOSED LOW THAT HAS BEEN SITTING ACROSS THE PLAINS TO THE OHIO VALLEY WILL BE SLOWLY ARRIVING IN OUR REGION. THE FRONT THAT SLID SOUTHWARD YESTERDAY HAS STALLED ACROSS THE DELMARVA. A PUSH OF DRIER AIR HAS BEEN TRYING TO GET INTO OUR FAR SOUTHERN ZONES. HOWEVER WITH THE MOISTURE REMAINING DEEPER HERE, AN ONSHORE FLOW, AND BOUNDARY LAYER COOLING HAS RESULTED IN AN AREA OF STRATUS AND FOG. SOME OF THE FOG IS DENSE. THE FORECAST SOUNDINGS, ESPECIALLY THE NAM/WRF SHOW A RATHER PRONOUNCED BUT SHALLOW MOIST LAYER NEAR THE SURFACE WHICH IS HELPING TO TRAP THE STRATUS. EVEN THIS IS FORECAST TO MIX OUT SOME THIS MORNING. IT APPEARS THAT THIS MAY NOT TRULY EXPAND GIVEN DRIER AIR SITTING ACROSS THE NORTHERN HALF OF THE CWA. WE ARE NOT CERTAIN THE DENSER PORTIONS OF THE FOG LAST LONGER THIS MORNING, THEREFORE WE HELD OFF ON ISSUING AN ADVISORY ATTM AND COVERED IT WITH A SPECIAL WEATHER STATEMENT. THE CLOUDS WILL BE WINNING OUT OVERALL TODAY AS HIGHER BASED CLOUDS LOWER THROUGH THE DAY. THE SLOWNESS OF THIS SYSTEM CONTINUES GIVEN HOW CUT OFF IT REMAINS TO BE. IN ADDITION, SOME DRIER AIR PUSHING SOUTHWESTWARD ACROSS MOST OF OUR AREA MIGHT ALSO DEFLECT AND DELAY THE SHOWERS MOSTLY TO OUR WEST FOR AWHILE. THEREFORE, WE TIGHTENED UP THE POPS SOME MORE WITH A SLOWER INCREASE ACROSS THE NORTHERN AREAS. IT APPEARS THAT INCREASING ASCENT AND ISENTROPIC LIFT AHEAD OF A VORTICITY MAXIMUM ROTATING AROUND THE CLOSED LOW INITIATES A BAND OF SHOWERS. THIS LOOKS TO BE THE INITIAL SPOKE OF SHOWERS THAT ROTATES ACROSS OUR AREA THROUGH TODAY. THERE COULD BE SOME MORE ISOLATED TO SCATTERED SHOWERS DEVELOPING AHEAD OF THIS. BASED ON THE EASTERLY FLOW ACROSS OUR REGION, THE MODEL GUIDANCE INDICATES THAT ANY DEVELOPING INSTABILITY WILL BE ELEVATED. THE BETTER INSTABILITY LOOKS TO BE PLACED ACROSS THE SOUTHERN AND SOUTHEASTERN ZONES WHERE A DEEPER MOISTURE PROFILE IS ACHIEVED FIRST ALONG WITH THE START OF SOME COOLING ALOFT. THIS INSTABILITY HOWEVER SHOULD NOT BE SURFACE BASED. THE CONVECTION ACROSS CENTRAL PENNSYLVANIA LOOKS TO BE TIED TO THE MAIN CONVEYOR BELT OF WAA. THIS IS FORECAST TO WEAKEN WITH AN EASTWARD EXTENT, BUT THEN BECOME FOCUSED TO OUR SOUTH. THE ONSHORE FLOW SHOULD PROTECT OUR REGION ALONG WITH THE MAIN WAA PUSH SLIDING TO OUR SOUTH, THEREFORE ANY SEVERE WEATHER THREAT LOOKS TO BE SOUTHWEST OF OUR REGION. WE CONTINUE TO CARRY A CHC OF THUNDERSTORMS ACROSS THE SOUTHERN AND SOUTHWESTERN ZONES. THE FLOW OVERALL IS FORECAST TO BE ON THE LIGHTER SIDE, THEREFORE CELL MOTION MAY TEND TO BE SLOW. THIS COULD RESULT IN CONVECTIVE CELLS PRODUCING LOCAL DOWNPOURS AS THE MOISTURE DEEPENS WITH THE PW VALUES FORECAST TO INCREASE INTO THE 1.0 TO 1.5 INCH RANGE. AS FOR TEMPERATURES, WE GENERALLY USED A MOS BLEND THEN MADE SOME TWEAKS ESPECIALLY ALONG THE COAST GIVEN THE ONSHORE FLOW. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... THE CLOSED LOW WILL BE WORKING ITS WAY INTO THE MID ATLANTIC REGION, AND THE MAJORITY OF THE SYNOPTIC SETUP WAS MENTIONED IN THE NEAR TERM SECTION ABOVE. SHORT WAVE ENERGY ROTATING AROUND THIS LARGE SYSTEM WILL ACT TO INITIATE BANDS OF SHOWERS. THE COVERAGE MAY START TO DECREASE DURING THE OVERNIGHT AS THE STRONGER LIFT SHIFTS TO OUR NORTHEAST. AS COOLING ALOFT TAKES PLACE, SOME INSTABILITY WILL KEEP SHOWERS GOING THROUGH THE NIGHT AND ANY THUNDER SHOULD MOSTLY BE CONFINED TO THE EVENING HOURS AND ACROSS THE SOUTHERN ZONES. A SURFACE LOW IS FORECAST TO TRACK CLOSE TO THE DELMARVA TOWARD MORNING, AND THIS WILL MAINTAIN AN ONSHORE FLOW ACROSS THE ENTIRE REGION. AS A RESULT, A WEALTH OF CLOUDS ARE EXPECTED TO CONTINUE. WHILE SOME FOG WILL BE AROUND, IT MAY NOT REDUCE THE VISIBILITIES ENOUGH AND THEREFORE IT WAS NOT INCLUDED IN THE PUBLIC FORECAST ATTM. AS FOR TEMPERATURES, WE MOSTLY BLENDED THE GFS/NAM MOS. THE TEMPERATURES MAY TAKE SOME TIME IN DROPPING ACROSS SOME AREAS FOR AWHILE TONIGHT GIVEN LOTS OF CLOUDS AND THE ONSHORE FLOW. && .LONG TERM /SUNDAY THROUGH FRIDAY/... A MID LEVEL LOW IS FORECAST TO BE OVER SOUTH CAROLINA ON SUNDAY MORNING. THE FEATURE IS EXPECTED TO PASS OFF THE COAST ON SUNDAY AFTERNOON BEFORE MOVING OUT TO SEA AND BECOMING AN OPEN WAVE. MEANWHILE, AT THE SURFACE BROAD LOW PRESSURE IS FORECAST TO EXTEND FROM THE CHESAPEAKE BAY REGION TO EASTERN NORTH CAROLINA EARLY ON SUNDAY. IT SHOULD SLOWLY PASS OFF THE COAST ON SUNDAY AFTERNOON AND EVENING. WE ARE EXPECTING TO BEGIN SUNDAY WITH THE LIKELIHOOD OF RAIN SHOWERS THROUGHOUT OUR REGION. HOWEVER, AS THE SURFACE LOW BEGINS TO MOVE OFF THE COAST DURING THE AFTERNOON SOME DRY AIR MAY BEGIN TO BUILD INTO OUR NORTHERN COUNTIES. ON SUNDAY, THE SURFACE FLOW SHOULD BE MAINLY FROM THE NORTHEAST, KEEPING CONDITIONS RATHER STABLE NEAR THE SURFACE. HOWEVER, THERE MAY BE ENOUGH INSTABILITY ALOFT TO RESULT IN SCATTERED THUNDERSTORMS IN OUR SOUTHERN COUNTIES ON SUNDAY AFTERNOON AND SUNDAY EVENING. SUNDAY`S TEMPERATURE FORECAST IS RATHER TRICKY. DEPENDING UPON WHERE MOST OF THE SHOWER ACTIVITY OCCURS AND DEPENDING UPON WHETHER ANY SUBSTANTIAL BREAKS IN THE CLOUD COVER DEVELOP, THE LOW NAM NUMBERS AND THE HIGH GFS NUMBERS ARE BOTH PLAUSIBLE. FOR NOW, WE HAVE SIMPLY GONE WITH A COMPROMISE OF THE STATISTICAL GUIDANCE. DRY AIR IS EXPECTED TO CONTINUE TO BUILD INTO OUR REGION FROM THE NORTH ON SUNDAY NIGHT, BRINGING AN END TO THE THREAT OF PRECIPITATION FROM NORTH TO SOUTH. A MID LEVEL TROUGH FROM THE NORTHWEST SHOULD BEGIN TO DROP OVER THE NORTHEASTERN STATES ON SUNDAY NIGHT, PUSHING A STRONG COLD FRONT THROUGH OUR REGION EARLY ON MONDAY. THE AXIS OF THE MID LEVEL TROUGH WILL LIKELY PASS OVER OUR REGION ON MONDAY AFTERNOON. DRY AIR IS EXPECTED TO BUILD INTO OUR REGION FOR THE EARLY PART OF THE WORK WEEK. TEMPERATURES SHOULD RETURN TO SEASONABLE LEVELS FOR MONDAY NIGHT AND TUESDAY. AFTER THE RECENT STRETCH OF VERY WARM WEATHER, IT MAY BE DIFFICULT TO BELIEVE THAT LOWS IN THE 30S AND HIGHS IN THE 50S IS NORMAL. ANOTHER MID LEVEL TROUGH SHOULD PASS OVER OUR REGION FROM WEDNESDAY NIGHT INTO THURSDAY. AS IT APPROACHES, A WARM FRONT IS FORECAST TO BE PULLED THROUGH OUR REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT ON WEDNESDAY NIGHT. WE HAVE INDICATED A CHANCE OF SHOWERS AT THAT TIME. HIGH PRESSURE AND DRY WEATHER ARE EXPECTED TO RETURN FOR THE END OF THE WEEK ALONG WITH SLIGHTLY ABOVE NORMAL TEMPERATURES. && .AVIATION /10Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THE LOW-LEVEL MOISTURE HAS BEEN SOCKED IN AT KMIV AND KACY AS AN AREA OF ENHANCED MOISTURE IS TRAPPED UNDER A RATHER STRONG BUT SHALLOW INVERSION. NOT TO FAR TO THE NORTH, DRIER AIR HAS BEEN SEEPING SOUTHWESTWARD WITH THE SURFACE DEW POINTS DROPPING SOME. IT IS NOT ALL THAT CLEAR IF THIS IS ABLE TO GET TO KMIV AND KACY AND UNDERCUT THE FOG. WE FAVORED MORE FOG FOR AWHILE THIS MORNING THEN INDICATED SOME IMPROVEMENTS BEFORE CONDITIONS LOWER ONCE AGAIN. OTHERWISE, THE AIR IS A BIT DRIER AT KILG AND THE KPHL METRO THEREFORE NOT REALLY ANY FOG HOWEVER THE STRATUS HAS BEEN SLIDING WESTWARD AND HAS MADE IT TO THESE TERMINALS. OUR CONFIDENCE IS LOW REGARDING HOW LONG THIS LINGERS, HOWEVER WE ARE LEANING TOWARD SOME IMPROVEMENT TAKING PLACE THIS MORNING BEFORE CONDITIONS LOWER ONCE AGAIN. SOME SHOWERS AND EVEN A FEW THUNDERSTORMS ARE MOVING SLOWLY NORTHWARD ACROSS MARYLAND AND PARTS OF DELAWARE. THIS MAY TEND TO HOLD SOUTH AND WEST OF OUR TERMINALS FOR AWHILE, THEREFORE WILL MONITOR RADAR TRENDS AND ISSUE AMENDMENTS IF THESE LOOK TO IMPACT A TERMINAL EARLIER THAN ANTICIPATED. A SLOW MOVING STORM SYSTEM WILL BE APPROACHING TODAY, AND THIS WILL ALLOW THE CLOUDS OVERALL TO INCREASE AND LOWER THROUGH THE DAY. IT APPEARS THE MAIN PUSH OF SHOWERS WILL BE SLOWER AS SOME OF THE DRIER AIR FROM THE NORTHEAST MAY ALSO HELP WITH THE DELAY. THE BULK OF THE SHOWERS LOOK TO OCCUR STARTING FROM ABOUT MIDDAY ONWARD. THERE IS THE POTENTIAL FOR A THUNDERSTORM OR TWO, ALTHOUGH THIS MAINLY LOOKS TO BE SOUTH AND WEST OF A KRDG TO KMIV LINE. OUR CONFIDENCE IS LOW ON THE COVERAGE, THEREFORE NO THUNDER WAS INCLUDED AT THIS TIME. THE SHOWERS SHOULD TEND TO ARRIVE IN A BAND FROM SOUTHWEST TO NORTHEAST. THE FLOW IS FAIRLY WEAK, THEREFORE THESE COULD BE SLOW MOVERS AND PRODUCE LOCAL DOWNPOURS. WE CONTINUED TO INDICATE LOWERING VISIBILITIES THROUGH THE DAY /OUTSIDE OF ANY EARLY MORNING FOG/. AN EASTERLY WIND WILL INCREASE TO AROUND 10 KNOTS, AND THERE COULD BE A LITTLE GUSTINESS FOR A TIME MAINLY FROM THE KPHL METRO SOUTH AND EAST. THE CONDITIONS ARE EXPECTED TO BE WIDESPREAD SUB-VFR TONIGHT AS SOME SHOWERS CONTINUE. GIVEN THE DEEPENING MOISTURE, SOME FOG SHOULD ALSO BE AROUND HOWEVER THIS IS NOT EXPECTED TO BE DENSE AT THIS TIME. THE EAST TO SOUTHEAST WINDS MAY TEND TO SHIFT MORE TO THE NORTHEAST TONIGHT BUT GENERALLY BE UNDER 10 KNOTS. OUTLOOK... SUNDAY...POSSIBLE MVFR/IFR CONDITIONS IN SHOWERS AND SCATTERED THUNDERSTORMS. SUNDAY NIGHT...VFR. MONDAY...VFR WITH A GUSTY NORTHWEST WIND. MONDAY NIGHT THROUGH TUESDAY NIGHT...VFR. WEDNESDAY...MAINLY VFR WITH A CHANCE OF SHOWERS. && .MARINE... AN AREA OF ENHANCED LOW-LEVEL MOISTURE TRAPPED UNDER A RATHER LOW INVERSION IS RESULTING IN SOME LOW CLOUDS AND FOG EARLY THIS MORNING, MAINLY SOUTH OF ATLANTIC CITY AND INTO DELAWARE BAY. SOME DRIER AIR IS TRYING TO UNDERCUT THIS, HOWEVER IT IS NOT REAL CERTAIN HOW THIS BEHAVES THROUGH THE MORNING. THE OVERALL FOG SHOULD IMPROVE THIS MORNING, THEREFORE NO HEADLINE BUT A MENTION WILL BE CARRIED IN THE FORECAST THROUGH ABOUT 12Z. A CLOSED LOW WILL GRADUALLY MOVE INTO OUR AREA THROUGH TONIGHT. AS LOW PRESSURE TRACKS ACROSS THE MID ATLANTIC REGION AND HIGH PRESSURE SETTLES OFF THE NEW ENGLAND COAST, A TIGHTENED PRESSURE GRADIENT WILL RESULT. THIS IS MAINLY THE GREATEST ACROSS THE NORTHERN WATERS, ALTHOUGH THE FORECAST SOUNDINGS SUGGEST THE SURFACE WINDS REMAIN BELOW ADVISORY CRITERIA. THE ONSHORE FLOW HOWEVER MAY ALLOW THE SEAS TO BUILD TO 5 FEET MAINLY ACROSS THE NORTHERN ZONES. THIS MAY END UP BEING MARGINAL AND DUE TO LOWER THAN AVERAGE CONFIDENCE, WE OPTED TO HOLD OFF ON ANY SMALL CRAFT ADVISORY ISSUANCE ATTM. OUTLOOK... BROAD LOW PRESSURE IS FORECAST TO PASS OFF THE MIDDLE ATLANTIC COAST ON SUNDAY. A STRONG COLD FRONT FROM THE NORTHWEST IS EXPECTED TO REACH THE COASTAL WATERS OF NEW JERSEY AND DELAWARE EARLY ON MONDAY, FOLLOWED BY HIGH PRESSURE. A WARM FRONT IS ANTICIPATED TO APPROACH FROM THE SOUTHWEST AND IT MAY ARRIVE ON WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED FROM LATE SUNDAY NIGHT INTO TUESDAY MORNING FOR THE GUSTY NORTHWEST WINDS IN THE COLD ADVECTION. ISOLATED GALE FORCE GUSTS MAY OCCUR FROM LATE MONDAY INTO MONDAY NIGHT. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...IOVINO NEAR TERM...GORSE SHORT TERM...GORSE LONG TERM...IOVINO AVIATION...GORSE/IOVINO MARINE...GORSE/IOVINO
AREA FORECAST DISCUSSION...UPDATED
NWS TALLAHASSEE FL
628 PM EDT Sat Mar 24 2012 .MESOSCALE UPDATE... An interesting mesoscale setup across our area early this evening that suggests the thunderstorm threat is not completely over for our land areas. The important feature that we have been tracking appears to be a surge of low-level moisture that is slowly propagating to the NNW, and currently arcs from near Lakeland, GA or Moody AFB, to the northwest side of Tallahassee, to near Carrabelle in Franklin County. The dewpoint at the TLH airport and the NWS office have increased about 10-12 degrees in the past hour and now sit around 66F. The push of low-level moisture has created a sharp thetae gradient and the boundary is even evident on the latest TLH radar reflectivity as well as on visible satellite (with a line of towering cumulus). Winds in the moist air mass have backed to a S-SSE direction, whereas winds in the drier air mass are almost due west. This should act to increase low-level convergence in the next several hours and could provide the necessary focus for additional thunderstorm development. The RUC and NAM have been handling this mesoscale feature rather well, and both indicate QPF in the 00-06z timeframe in our SE areas. Modifying a 01z RUC forecast sounding for VLD with 77/66 surface conditions yields about 1500-2000 j/kg of CAPE with very little CINH for a parcel lifted from near the surface. The other thing to consider is that deep layer shear will be on the increase in the next few hours, so any storm that can tap this environment may be a little more organized than what we saw earlier. The main message is that thunderstorm potential is not necessarily over, and we cannot rule out a severe thunderstorm or two prior to midnight in our southeastern areas. && .PREV DISCUSSION (issued at 237 PM EDT Sat Mar 24 2012)... SHORT TERM (Tonight through Monday night)...Cold front associated with the deep upper low will finally exit the forecast area this evening. Showers and thunderstorms will likely linger into the mid-evening hours over the eastern big bend before ending by midnight. With the latest VWP data showing winds veering substantially at KVLD, severe threat should be rather low. A drier airmass will arrive in the wake of the front. This will allow overnight lows to fall back into the lower to mid 50s for the next few nights. However, highs will continue to reach the lower to mid 80s each afternoon. After this evening, no rain is expected throug Monday night. LONG TERM (Tuesday through next Saturday)...There is good consensus between the models that the long term period will remain rather calm, with a benign weather pattern in place. The northern stream flow will remain across the northern half of the country through the period, with a chain of shortwaves forecast to pass through it. Across the southern part of the country, a mix of ridging and a zonal flow regime will dominate. As each of the aforementioned shortwaves pass well north of the local area, they will have little effect on the local weather, with the exception of dampening any ridging that is occurring over the southeastern part of the country. The result of this pattern will be dry and warm afternoons, with mild evenings. Temperatures are forecast to climb into the lower to middle 80s each afternoon, with low temperatures bottoming out in the middle to upper 50s. No mentionable rain chances exist through the period. AVIATION (through 18Z Sunday)... A weak cold front was pushing slowly southeastward across eastern portions of the Tri-State Area this afternoon. Along and ahead of the front, bands of showers and isolated thunderstorms continued to develop over southern and eastern portions of the Big Bend and adjacent coastal waters, accompanied by MVFR ceilings. The showers and storms will clear the southeast Big Bend by late tonight as the front pushes south of the area, and VFR conditions will prevail through the remainder of the forecast period and beyond. Winds Sunday will be generally northwest 8 to 12 knots with occasional gusts to around 15 knots. MARINE...Winds will turn from the west to the northwest overnight in the wake of a cold front. Wind speeds are expected to remain just below headline criteria. A very weak pressure gradient for Monday into Tuesday will keep winds and seas minimal. Easterly flow will increase by mid-week as high pressure builds along the eastern seaboard. FIRE WEATHER...Drier air will be spreading across the Tri-State Area tonight and Sunday, on the heels of a cold front that will push south and east of the area later tonight. Relative humidities are forecast to fall to critical levels across all but the immediate coastal areas of the eastern Florida Panhandle and Big Bend, as well as southeast Alabama on Sunday afternoon. Durations across southeast Alabama are not expected to be met. However, dispersions across Florida zones are expected to exceed 75, and a Red Flag Warning will be issued for all but the coastal zones of Florida. On Monday and Tuesday, relative humidities are expected to approach or briefly drop below red flag criteria, however durations are not expected to be met. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 54 81 52 84 53 / 10 0 0 0 0 Panama City 59 79 60 79 61 / 10 0 0 0 0 Dothan 54 80 55 84 56 / 0 0 0 0 0 Albany 53 79 53 82 55 / 10 0 0 0 0 Valdosta 54 79 53 82 54 / 20 0 0 0 0 Cross City 58 81 52 83 53 / 50 10 0 0 0 Apalachicola 59 76 57 77 60 / 10 0 0 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...None. GA...None. FL...Red Flag Warning from 2 PM EDT /1 PM CDT/ to 7 PM EDT /6 PM CDT/ Sunday for Calhoun-Central Walton-Gadsden-Holmes-Inland Bay- Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson- Inland Taylor-Inland Wakulla-Inland Walton-Jackson- Lafayette-Leon-Liberty-Madison-Washington. GM...None. && $$ Update...08-Lamers
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
750 AM EDT SAT MAR 24 2012 .SYNOPSIS... A SLIGHT CHANCE OF SEVERE THUNDERSTORMS TODAY AS A WARM AND MOIST AIR MASS BLANKETS THE REGION. A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT WITH HIGH PRESSURE SLOWLY BUILDING IN FROM THE NORTHWEST SUNDAY THROUGH MONDAY. A FRONT WILL DROP THROUGH ON TUESDAY...THEN ANOTHER COLD FRONT WILL MOVE IN LATE IN THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... NEARING-DAWN...OVERNIGHT MSAS AND RUC MESOANALYSIS DATA SHOWS ATMOSPHERIC DESTABILIZATION AS 850 MB THETA-E ADVECTION SURGES IN FROM SW GEORGIA AND THE FLORIDA PANHANDLE. REGIONAL RADARS INDICATED SHOWERS WERE BREAKING OUT IN THE AXIS OF LOW LEVEL MOISTURE TRANSPORT...A FEW WERE ALREADY NOTED ACROSS INLAND SE GEORGIA. MSAS AND RUC MESOANALYSIS BOTH SHOW THAT THE AIR MASS HAS DESTABILIZED AND TSTMS WILL BE POSSIBLE ANYTIME AFTER SUNRISE. FORECAST TODAY BLENDED BETWEEN PERSISTENCE AND CONSENSUS SYNOPTIC SCALE TRENDS FROM THE 00Z MODEL RUN. OUR REGION CONTINUES TO BE HIGHLIGHTED UNDER A SLIGHT RISK FOR SEVERE CONVECTION TODAY AND ONGOING TRENDS GIVE NO INDICATION TO SWAY FROM THAT THINKING. TO BEGIN TODAY...OVERNIGHT SATELLITE TRENDS SUGGEST THAT THERE LIKELY WILL BE AREAS OF INSOLATION ACROSS GEORGIA AND SOUTH CAROLINA WHICH WILL RAPIDLY ENHANCE DESTABILIZATION. CUTTING THROUGH OUR INLAND ZONES IS AN IMPRESSIVE DEEP MOISTURE GRADIENT TODAY WITH PWATS E OF I-95 AT OR SLIGHTLY ABOVE 1.5 INCHES AND INLAND FROM THERE FALLING WELL BELOW 1 INCH THIS AFTERNOON. CONVECTION IS EXPECTED TO FLOURISH ALONG AND SE OF THIS GRADIENT FROM LATE MORNING THROUGH THE AFTERNOON. BY 18Z...THE GEM/GFS/ECMWF ALL SHOW HAIL CAPES EXCEEDING 600 J/KG OVER S GEORGIA AND ANOTHER MORE MORE IMPRESSIVE MAXIMA OVER THE EASTERN SOUTH CAROLINA MIDLANDS EXTENDING INTO OUR INLAND SOUTH CAROLINA ZONES. THE MID LEVEL ENVIRONMENT WILL REMAIN FAIRLY UNIFORM THROUGH MID AFTERNOON WITH LATE DAY HEIGHT FALLS NOTED FROM THE ESE MOVEMENT OF THE DEEP UPPER LOW OVER THE TENNESSEE/KENTUCKY REGION. THE ENVIRONMENT IS HIGHLIGHTED BY FAIR LAPSE RATES NEAR -6C AND FAVORABLE HAIL PARAMETERS PROVIDED CONVECTIVE INITIATION IS NOT TOO FAST TODAY. 0-6KM BULK SHEAR IS FORECAST TO INCREASE STEADILY TO AROUND 40 KT BY LATE DAY...INCREASING POTENTIAL FOR ENHANCED ORGANIZATION AND MIXED-MODE CONVECTION. MODELS SUGGEST THE FIRST ROUND TODAY WILL DEVELOP IN SE GEORGIA AND DEVELOP OR PROPAGATE ALONG BOUNDARIES NE THROUGH THE COASTAL HALF OF THE FORECAST AREA THIS AFTERNOON WITH ISOLATED SEVERE TSTMS POSSIBLE. TSTMS WITH MORE ROBUST HAIL AND WIND POTENTIAL WILL LIKELY BEGIN TO TAKE SHAPE IN A N-S CONVERGENCE ZONE TO THE S OF WEAK SURFACE LOW IN UPSTATE SOUTH CAROLINA. THESE STORMS WILL POSE A LATE DAY THREAT TO OUR INLAND ZONES WITH FAIR CHANCES FOR CONVECTIVE WATCHES BY MID AFTERNOON FOR PARTS OF OUR FORECAST AREA. WE RAISED MAX TEMPS A COUPLE OF DEGREES TODAY IN ADVANCE OF CONVECTION. DEEPER MIXED LAYER INLAND SUGGEST SW SURFACE WINDS COULD BECOME A BIT GUSTY AT TIMES THIS AFTERNOON. && .SHORT TERM /SUNDAY THROUGH MONDAY/... THE NAM SUGGESTS STRONG TO SEVERE CONVECTION WILL SHIFT TOWARD THE COAST THIS EVENING AS STRONG UPPER HEIGHT FALLS KICK IN AND OUR REGION COMES UNDER A FAIRLY IMPRESSIVE RIGHT ENTRANCE REGION IN A 250 MB JET SEGMENT. OTHER MODELS SHIFT DEEPER MOISTURE AND INSTABILITY OFFSHORE A BIT QUICKER BUT WILL HIGHLIGHT A SEVERE RISK CONTINUING UNTIL MIDNIGHT IN RESPECT TO THE AIR MASS IN PLACE TODAY AND THE STRENGTH OF THE SYNOPTIC SCALE SYSTEM. THE DEEP 500 MB LOW WILL ROTATE THROUGH SOUTHERN SC SUNDAY AFTERNOON WITH THE CENTER PASSING NEAR OR JUST NORTH OF CHARLESTON AROUND 18Z. MOST OF THE MODELS PROG 500 MB TEMPS OF -22C AT 18Z SUNDAY WITH A FREEZING LEVEL BELOW 7500 FT. A FAIRLY DEEP WESTERLY FLOW WILL DRY THE LOWER ATMOSPHERE AND DOWNSLOPE FLOW WILL RESULT IN SUBSIDENCE. HOWEVER THERE LOOKS TO BE ENOUGH LOW-LEVEL MOISTURE WRAPPING AROUND THE SURFACE LOW ALONG THE NC COAST TO SPUR A FEW SHOWERS OR ISOLATED THUNDERSTORMS DURING THE HOURS OF PEAK HEATING ON SUNDAY...MAINLY ACROSS SOUTHERN SC. DUE TO SUCH COLD TEMPERATURES ALOFT...SOME SMALL HAIL CANNOT BE RULED OUT WITH ANY CONVECTIVE ELEMENTS. DESPITE THE COLD ADVECTION...DOWNSLOPING WILL PUSH HIGH TEMPS INTO THE UPPER 70S. CLOUDS WILL CLEAR OUT FROM SW TO NE SUNDAY NIGHT AND WEAK COLD ADVECTION WILL DROP OVERNIGHT LOWS INTO THE LOWER 50S. THE UPPER LEVEL RIDGE AXIS WILL BUILD TOWARD THE SOUTHEAST UNITED STATES MONDAY INTO TUESDAY. BUILDING LOW-LEVEL THICKNESSES ON MONDAY WITH SUNNY SKIES WILL PUSH HIGH TEMPS BACK INTO THE LOWER 80S. A BACKDOOR COLD FRONT WILL DROP THROUGH LATE MONDAY NIGHT INTO TUESDAY WITH COOLER AIR FILTERING IN FROM THE NORTH. A RATHER SHARP TEMPERATURE GRADIENT IS EXPECTED FOR TUESDAY WITH NEAR 80 TO THE FAR SW AND LOWER 70S OVER THE TRI-COUNTY. ISOLATED SHOWERS CANNOT BE ENTIRELY RULED OUT ON TUESDAY...ESPECIALLY SOUTHERN SECTIONS WHERE A WEAK COASTAL TROUGH MAY DEVELOP. BUT DUE TO A RELATIVE LACK OF MOISTURE WE KEPT DRY CONDITIONS FOR NOW. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... HIGH PRESSURE WILL STRENGTHEN OVER THE WESTERN ATLANTIC TUESDAY NIGHT THROUGH THURSDAY AS THE UPPER RIDGE HOLDS STRONG TO OUR WEST. DRY CONDITIONS AND WARM TEMPERATURES EXPECTED WITH HIGHS BUILDS INTO THE UPPER 70S WEDNESDAY AND LOWER 80S THURSDAY. ANOTHER BACKDOOR FRONT MAY DROP THROUGH THURSDAY NIGHT OR FRIDAY WITH INCREASING CLOUDINESS AND COOLER TEMPERATURES. WE HAVE NOT ADDED ANY PRECIPITATION IN THE EXTENDED DUE TO LIMITED MOISTURE WITH THE LATE WEEK FRONT. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... CONVECTION TIMING AND INTENSITY VERY TRICKY ALONG THE COASTAL CORRIDOR TODAY AND EVEN THROUGH THIS EVENING. SHOWERS AND TSTMS WILL BRUSH THE REGION FROM MID MORNING INTO THIS AFTERNOON. BRIEF MVFR CIGS/VSBYS POSSIBLE IN DOWNPOURS. THIS EVENING IT APPEARS THE BEST BET FOR CONVECTIVE RAINS WILL IMPACT THE CHARLESTON TRI-COUNTY AREA NORTH GIVE INSTABILITY AND LIFT PROGS. THE COLD FRONT WILL MOVE THROUGH AFTER MIDNIGHT... A WIND SHIFT TO LIGHT W AND SOME LATE NIGHT CLEARING EXPECTED. WE MAINTAINED SOME SURFACE WIND GUSTS NEARING 20 KT AT KCHS AND AT LEAST TEMPO GUSTS AT TIMES AT KSAV AS WELL THIS AFTERNOON. EXTENDED AVIATION OUTLOOK...BRIEF MVFR VSBY POSSIBLE AT CHS ON SUNDAY IN ISO/SCT SHOWERS/TSTMS. OTHERWISE VFR. && .MARINE... NO SIGNIFICANT CHANGES WITH SW FLOW SHIFTING W IN THE WAKE OF THE COLD FRONT TONIGHT. SPEEDS WILL MAINLY BE 15 KT OR LESS WITH SOME GUSTS TO 20 KT AT TIMES BEYOND 20 NM OFF THE COAST. SEAS THROUGH TONIGHT 2-4 NEAR SHORE AND 3 TO 5 FT OVER OUTER GEORGIA WATERS. OFFSHORE FLOW BEHIND THE COLD FRONT ON SUNDAY WILL ALLOW SEAS TO GRADUALLY SUBSIDE. A BRIEF NORTHEAST WIND SURGE WILL DEVELOP TUESDAY MORNING BEHIND A BACKDOOR COLD FRONT BUT IT SHOULD BE OF SHORT DURATION AS THE PARENT HIGH SHIFTS QUICKLY OFFSHORE. THE NEXT SURGE WILL COME WEDNESDAY NIGHT INTO THURSDAY AHEAD OF THE NEXT COLD FRONT. IN GENERAL WE KEEP WINDS/SEAS BELOW ADVISORY THRESHOLDS DURING THE MEDIUM RANGE PERIOD. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ SYNOPSIS...JRL NEAR TERM... SHORT TERM...JRL LONG TERM...JRL AVIATION... MARINE...JRL
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
432 AM EDT SAT MAR 24 2012 .SYNOPSIS... A SLIGHT CHANCE OF SEVERE THUNDERSTORMS TODAY AS A WARM AND MOIST AIR MASS BLANKETS THE REGION. A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT WITH HIGH PRESSURE SLOWLY BUILDING IN FROM THE NORTHWEST SUNDAY THROUGH MONDAY. A FRONT WILL DROP THROUGH ON TUESDAY...THEN ANOTHER COLD FRONT WILL MOVE IN LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... PRE-DAWN...OVERNIGHT MSAS AND RUC MESOANALYSIS DATA SHOWS MUCH OF OUR FORECAST AREA REMAINED STABILIZED BY THE EARLIER CONVECTION WITH INSTABILITY GRADIENTS RUNNING ALONG THE CSRA AND ALTAMAHA RIVER REGIONS BORDERING OUR FORECAST AREA. THIS WILL BE QUICK TO CHANGE LATER THIS MORNING BUT UNTIL THEN WE ARE MONITORING FOR SOME PATCHY FOG AND STRATUS AND WITH SPOTTY CONVECTIVE RAINS POSSIBLE UNTIL DAYBREAK. FORECAST TODAY BLENDED BETWEEN PERSISTENCE AND CONSENSUS SYNOPTIC SCALE TRENDS FROM THE 00Z MODEL RUN. OUR REGION CONTINUES TO BE HIGHLIGHTED UNDER A SLIGHT RISK FOR SEVERE CONVECTION TODAY AND ONGOING TRENDS GIVE NO INDICATION TO SWAY FROM THAT THINKING. TO BEGIN TODAY...OVERNIGHT SATELLITE TRENDS SUGGEST THAT THERE LIKELY WILL BE AREAS OF INSOLATION ACROSS GEORGIA AND SOUTH CAROLINA WHICH WILL RAPIDLY ENHANCE DESTABILIZATION. CUTTING THROUGH OUR INLAND ZONES IS AN IMPRESSIVE DEEP MOISTURE GRADIENT TODAY WITH PWATS E OF I-95 AT OR SLIGHTLY ABOVE 1.5 INCHES AND INLAND FROM THERE FALLING WELL BELOW 1 INCH THIS AFTERNOON. CONVECTION IS EXPECTED TO FLOURISH ALONG AND SE OF THIS GRADIENT FROM LATE MORNING THROUGH THE AFTERNOON. BY 18Z...THE GEM/GFS/ECMWF ALL SHOW HAIL CAPES EXCEEDING 600 J/KG OVER S GEORGIA AND ANOTHER MORE MORE IMPRESSIVE MAXIMA OVER THE EASTERN SOUTH CAROLINA MIDLANDS EXTENDING INTO OUR INLAND SOUTH CAROLINA ZONES. THE MID LEVEL ENVIRONMENT WILL REMAIN FAIRLY UNIFORM THROUGH MID AFTERNOON WITH LATE DAY HEIGHT FALLS NOTED FROM THE ESE MOVEMENT OF THE DEEP UPPER LOW OVER THE TENNESSEE/KENTUCKY REGION. THE ENVIRONMENT IS HIGHLIGHTED BY FAIR LAPSE RATES NEAR -6C AND FAVORABLE HAIL PARAMETERS PROVIDED CONVECTIVE INITIATION IS NOT TOO FAST TODAY. 0-6KM BULK SHEAR IS FORECAST TO INCREASE STEADILY TO AROUND 40 KT BY LATE DAY...INCREASING POTENTIAL FOR ENHANCED ORGANIZATION AND MIXED-MODE CONVECTION. MODELS SUGGEST THE FIRST ROUND TODAY WILL DEVELOP IN SE GEORGIA AND DEVELOP OR PROPAGATE ALONG BOUNDARIES NE THROUGH THE COASTAL HALF OF THE FORECAST AREA THIS AFTERNOON WITH ISOLATED SEVERE TSTMS POSSIBLE. TSTMS WITH MORE ROBUST HAIL AND WIND POTENTIAL WILL LIKELY BEGIN TO TAKE SHAPE IN A N-S CONVERGENCE ZONE TO THE S OF WEAK SURFACE LOW IN UPSTATE SOUTH CAROLINA. THESE STORMS WILL POSE A LATE DAY THREAT TO OUR INLAND ZONES WITH FAIR CHANCES FOR CONVECTIVE WATCHES BY MID AFTERNOON FOR PARTS OF OUR FORECAST AREA. WE RAISED MAX TEMPS A COUPLE OF DEGREES TODAY IN ADVANCE OF CONVECTION. DEEPER MIXED LAYER INLAND SUGGEST SW SURFACE WINDS COULD BECOME A BIT GUSTY AT TIMES THIS AFTERNOON. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/... THE NAM SUGGESTS STRONG TO SEVERE CONVECTION WILL SHIFT TOWARD THE COAST THIS EVENING AS STRONG UPPER HEIGHT FALLS KICK IN AND OUR REGION COMES UNDER A FAIRLY IMPRESSIVE RIGHT ENTRANCE REGION IN A 250 MB JET SEGMENT. OTHER MODELS SHIFT DEEPER MOISTURE AND INSTABILITY OFFSHORE A BIT QUICKER BUT WILL HIGHLIGHT A SEVERE RISK CONTINUING UNTIL MIDNIGHT IN RESPECT TO THE AIR MASS IN PLACE TODAY AND THE STRENGTH OF THE SYNOPTIC SCALE SYSTEM. THE DEEP 500 MB LOW WILL ROTATE THROUGH SOUTHERN SC SUNDAY AFTERNOON WITH THE CENTER PASSING NEAR OR JUST NORTH OF CHARLESTON AROUND 18Z. MOST OF THE MODELS PROG 500 MB TEMPS OF -22C AT 18Z SUNDAY WITH A FREEZING LEVEL BELOW 7500 FT. A FAIRLY DEEP WESTERLY FLOW WILL DRY THE LOWER ATMOSPHERE AND DOWNSLOPE FLOW WILL RESULT IN SUBSIDENCE. HOWEVER THERE LOOKS TO BE ENOUGH LOW-LEVEL MOISTURE WRAPPING AROUND THE SURFACE LOW ALONG THE NC COAST TO SPUR A FEW SHOWERS OR ISOLATED THUNDERSTORMS DURING THE HOURS OF PEAK HEATING ON SUNDAY...MAINLY ACROSS SOUTHERN SC. DUE TO SUCH COLD TEMPERATURES ALOFT...SOME SMALL HAIL CANNOT BE RULED OUT WITH ANY CONVECTIVE ELEMENTS. DESPITE THE COLD ADVECTION...DOWNSLOPING WILL PUSH HIGH TEMPS INTO THE UPPER 70S. CLOUDS WILL CLEAR OUT FROM SW TO NE SUNDAY NIGHT AND WEAK COLD ADVECTION WILL DROP OVERNIGHT LOWS INTO THE LOWER 50S. THE UPPER LEVEL RIDGE AXIS WILL BUILD TOWARD THE SOUTHEAST UNITED STATES MONDAY INTO TUESDAY. BUILDING LOW-LEVEL THICKNESSES ON MONDAY WITH SUNNY SKIES WILL PUSH HIGH TEMPS BACK INTO THE LOWER 80S. A BACKDOOR COLD FRONT WILL DROP THROUGH LATE MONDAY NIGHT INTO TUESDAY WITH COOLER AIR FILTERING IN FROM THE NORTH. A RATHER SHARP TEMPERATURE GRADIENT IS EXPECTED FOR TUESDAY WITH NEAR 80 TO THE FAR SW AND LOWER 70S OVER THE TRI-COUNTY. ISOLATED SHOWERS CANNOT BE ENTIRELY RULED OUT ON TUESDAY...ESPECIALLY SOUTHERN SECTIONS WHERE A WEAK COASTAL TROUGH MAY DEVELOP. BUT DUE TO A RELATIVE LACK OF MOISTURE WE KEPT DRY CONDITIONS FOR NOW. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... HIGH PRESSURE WILL STRENGTHEN OVER THE WESTERN ATLANTIC TUESDAY NIGHT THROUGH THURSDAY AS THE UPPER RIDGE HOLDS STRONG TO OUR WEST. DRY CONDITIONS AND WARM TEMPERATURES EXPECTED WITH HIGHS BUILDS INTO THE UPPER 70S WEDNESDAY AND LOWER 80S THURSDAY. ANOTHER BACKDOOR FRONT MAY DROP THROUGH THURSDAY NIGHT OR FRIDAY WITH INCREASING CLOUDINESS AND COOLER TEMPERATURES. WE HAVE NOT ADDED ANY PRECIPITATION IN THE EXTENDED DUE TO LIMITED MOISTURE WITH THE LATE WEEK FRONT. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... ADDITIONAL SHOWERS BREAKING OUT TO THE W OF I-95 AND WILL LIKELY SKIRT W OF BOTH TERMINALS OVERNIGHT BUT CANNOT RULE OUT SPOTTY CONVECTIVE RAINS OVERNIGHT IN THE COASTAL CORRIDOR. VFR CONDITIONS ARE LIKELY BUT WITH POCKETS OF MVFR/IFR CIGS ON CURRENT REGIONAL OBSERVATIONS...LOWER CONDITIONS ALSO CANNOT BE RULED OUT. SCATTERED BOUTS OF CONVECTION ARE LIKELY TODAY...AS EARLY AS MID TO LATE MORNING AND THEN PERHAPS STRONGER CONVECTION LATE TODAY AND THIS EVENING AHEAD OF A COLD FRONT AND THE SE SAGGING MID LEVEL CUT-OFF LOW UPSTREAM. CONFIDENCE ON TIMING THESE ROUNDS OF SHOWERS AND TSTMS IS QUESTIONABLE GIVEN SUBTLETIES IN MODEL OUTPUT DIFFERENCES. WE HAVE BROAD-BRUSHED VCSH WITH CB MENTIONS THIS AFTERNOON AND EVENING UNTIL RADAR TRENDS DICTATE TEMPO OR PREVAILING GROUPS OF CONVECTION. WE INTRODUCED SOME SURFACE WIND GUSTS NEARING 20 KT AT KCHS AND AT LEAST TEMPO GUSTS AT TIMES AT KSAV AS WELL THIS AFTERNOON. EXTENDED AVIATION OUTLOOK...BRIEF MVFR VSBY POSSIBLE AT CHS ON SUNDAY IN ISO/SCT SHOWERS/TSTMS. OTHERWISE VFR. && .MARINE... NO SIGNIFICANT CHANGES WITH SW FLOW SHIFTING W IN THE WAKE OF THE COLD FRONT TONIGHT. SPEEDS WILL MAINLY BE 15 KT OR LESS WITH SOME GUSTS TO 20 KT AT TIMES BEYOND 20 NM OFF THE COAST. SEAS THROUGH TONIGHT 2-4 NEAR SHORE AND 3 TO 5 FT OVER OUTER GEORGIA WATERS. OFFSHORE FLOW BEHIND THE COLD FRONT ON SUNDAY WILL ALLOW SEAS TO GRADUALLY SUBSIDE. A BRIEF NORTHEAST WIND SURGE WILL DEVELOP TUESDAY MORNING BEHIND A BACKDOOR COLD FRONT BUT IT SHOULD BE OF SHORT DURATION AS THE PARENT HIGH SHIFTS QUICKLY OFFSHORE. THE NEXT SURGE WILL COME WEDNESDAY NIGHT INTO THURSDAY AHEAD OF THE NEXT COLD FRONT. IN GENERAL WE KEEP WINDS/SEAS BELOW ADVISORY THRESHOLDS DURING THE MEDIUM RANGE PERIOD. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ SYNOPSIS...JRL NEAR TERM... SHORT TERM...JRL LONG TERM...JRL AVIATION... MARINE...JRL
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
950 PM CDT SUN MAR 25 2012 .UPDATE... AREA OF SHOWERS AND ISOLD TSTMS OVER WESTERN MN OCCURRING IN ZONE OF ELEVATED WARM ADVECTION AND THETA-E CONVERGENCE IN 850-700 MB LAYERS. 00Z NAM SHOWS WARM ADVECTION AND THETA-E CONVERGENCE INCREASING OVRNGT IN AREAS MAINLY N/NE OF QUAD CITIES. SOME OF THE MOST RECENT RUNS OF HRRR AND RUC BACKUP MODELS HAVE BEEN SHOWING PCPN COMING INTO NORTH... ALBEIT SLOW ON TRENDS. HAVE GONE AHEAD AND ADDED POPS TO AREAS NORTH OF QUAD CITIES OVRNGT AND MADE SOME ADJUSTMENTS TO POPS MON. UPDATED GRIDS AND ZFP OUT SHORTLY. && .PREV DISCUSSION... /ISSUED 652 PM CDT SUN MAR 25 2012/ AVIATION... VFR CONDITIONS TO PERSIST THIS EVENING. LOW CLOUDS WITH MVFR CIGS EXPECTED TO DEVELOP OR MOVE IN FROM EAST OVRNGT WITH LAKE ENHANCED FRONTAL ZONE AND SHOULD REMAIN THROUGH THE AM BEFORE LIFTING TO VFR DURING THE AFTN. POTENTIAL EXISTS FOR IFR CIGS ESPECIALLY NEAR MISSISSIPPI RVR LATE TNGT THROUGH MID AM MON ALONG WITH SOME FOG WITH VSBYS 2-5SM. LIGHT WIND OR NORTH WIND NEAR 5 KTS EARLY THIS EVE WILL GRADUALLY SHIFT TO EAST AND WILL INCREASE TO 15-20 KTS... WITH HIGHER GUSTS AROUND 25 KTS LATE TNGT THROUGH MON. THERE IS A SMALL CHANCE OF A SHOWER LATE TNGT AND MON AM ACROSS MAINLY NE IA INTO NW IL WITH ELEVATED WARM ADVECTION... BUT CHCS APPEAR TOO LOW FOR MENTION AT KDBQ TERMINAL FOR NOW. PREV DISCUSSION... /ISSUED 311 PM CDT SUN MAR 25 2012/ SYNOPSIS... THE MORNING UA ANALYSIS HAD AN UPPER RIDGE OVER THE PLAINS WITH A S/W OVER LAKE SUPERIOR. THE COLD FRONT TRAILING THE S/W WAS NOT EVIDENT IN THE SURFACE WIND/PRESSURE FIELDS AT 18Z HOWEVER THERE WAS A NICE THERMAL GRADIENT ALONG THE SOUTHERN EDGE OF THE TRAILING NORTHERN PLAINS HIGH PRESSURE RIDGE. THE 18Z ANALYSIS SHOWED 70 PLUS TEMPS AS FAR NORTH AS KDBQ AND TEMPS AROUND 60 IN NORTHEAST IA AND SOURTHEASTERN MN. SHORT TERM...TONIGHT AND MONDAY... THE LOW LEVEL FLOW WILL TURN MORE EASTERLY OVERNIGHT AS THE NORTHERN PLAINS SURFACE RIDGE SLIDES SOUTHEAST INTO THE GREAT LAKES. THE EASTERLY FLOW WILL BRING MUCH COOLER AIR INTO THE REGION FOR LATE TONIGHT AND MONDAY. EXPECT CLOUDS TO INCREASE LATE THIS EVENING AND OVERNIGHT AS LOW LEVELS COOL AND SATURATE. MID CLOUDS WILL ALSO SPREAD OVER THE AREA AFTER MIDNIGHT WITH INCREASING MID LEVEL WAA. FORCING OVERNIGHT DOES NOT LOOK THAT STRONG SO KEPT THE FORECAST DRY. THERE IS SOME POTENTIAL FOR DRIZZLE WITH THE ARRIVAL OF THE MOIST LOW LEVEL AIR OFF LAKE MI...BUT FORECAST SOUNDINGS WERE SHOWING A FAIRLY DEEP SATURATED LAYER WHICH ISN/T FAVORABLE FOR DRIZZLE. SOME LOW POPS WERE INCLUDED FOR MONDAY WHEN LOW AND MID LEVEL FGEN SPREADS SOUTHEAST THROUGH NORTHEASTERN CWFA. LOWS TONIGHT WILL BE CONSIDERABLY COLDER THAN WHAT THE REGION HAS EXPERIENCED THE LAST COUPLE OF WEEKS WITH MID TO UPPER 30S EXPECTED IN THE NORTHEASTERN CWFA. IT/S QUESTIONABLE IF THE COLDER AIR WILL REACH THE SOUTHWEST CWFA BY MORNING SO KEPT MINS THERE IN THE LOWER 50S. MONDAY TEMPERATURES OVER THE NORTHEASTERN HALF OF THE CWFA WILL NOT REBOUND MUCH WITH STRONG EASTERLY WINDS...CLOUDS AND POSSIBLY SOME RAIN SHOWERS SO KEPT HIGHS IN THE MID 40S WHILE THE SOUTHWEST HAS THE POTENTIAL TO SEE HIGHS IN THE LOW TO MID 60S. ..DLF.. LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY... TUESDAY WILL BE ANOTHER WARM AND BREEZY DAY WITH SCATTERED THUNDERSTORMS ALONG AND AHEAD OF A PASSING COLD FRONT. SLIGHTLY COOLER...BUT CONTINUED ABOVE NORMAL...TEMPERATURES TO THEN FOLLOW THROUGH MUCH OF THE WORKWEEK. RIDGE AT THE SURFACE AND ALOFT WILL FAVOR DRY CONDITIONS...FOLLOWED BY INCREASINGLY UNSETTLED WEATHER FRIDAY THROUGH NEXT WEEKEND AS THE THE UPPER FLOW BECOMES MORE AMPLIFIED. MONDAY NIGHT...VERY STRONG LOW LEVEL JET...WITH 850 WINDS PROGGED FROM 50 TO 70 KTS...IS SHOWN SURGING GULF MOISTURE FROM THE SOUTHERN PLAINS INTO THE UPPER MS VALLEY OUT AHEAD OF LOW PRESSURE DEVELOPING IN THE NORTHERN PLAINS. WHILE THIS IS DIRECTED WELL TO OUR WEST...THERE REMAINS A LOW POTENTIAL FOR STRAY ELEVATED WARM AIR ADVECTION SHOWERS OVER THE ESPECIALLY THE NORTHERN HALF OF THE FORECAST AREA...AND ALSO POSSIBLY OF MORE ORGANIZED SHOWERS OR AN ISOLATED THUNDERSTORMS ON THE EDGE OF THE STEEPER MID LEVEL LAPSE RATES TO OUR WEST TO WANDER INTO EASTERN IA TOWARD MORNING. WILL KEEP SLIGHT TO LOW CHANCE POPS ACROSS THE NORTH TO COVER THIS. OTHERWISE...THE DEEPENING LOW OVER THE NORTHERN PLAINS WILL PROVIDE A TIGHTENING PRESSURE GRADIENT AND BRISK SOUTHEAST TO SOUTH WINDS OVERNIGHT UNDER MOSTLY CLOUDY SKIES. UNTIL A SOMEWHAT DIFFUSE SURFACE WARM FRONT DEVELOPS AND SPREADS NORTHEAST INTO THE FORECAST AREA TOWARD MORNING...THE RELATIVELY DRY LOW LEVEL SOUTHEAST FLOW OUT OF THE RIDGE WILL HOLD TEMPERATURES IN THE 40S NORTH TO LOWER 50S SOUTH THROUGH THE NIGHT. TUESDAY...THE ASSOCIATED COLD FRONT SWEEPS THROUGH FROM LATE MORNING THROUGH MID AFTERNOON. LATEST MODELS DEPICT A GREAT DEAL OF MOISTURE AT OR BELOW 850 MB AND HAVE GONE WITH MOSTLY CLOUDY SKIES. EVEN WITH THE CLOUD COVER...LOW LEVEL WARM ADVECTION ON 15 TO 25 MPH SOUTH WINDS AHEAD OF THE FRONT SHOULD RESULT IN HIGHS WELL INTO THE 70S OVER ALL BUT THE FAR NORTHEAST. THIS WARMING...COMBINED WITH DEWPOINTS PUSHING INTO THE UPPER 50S IS SHOWN BY THE NAM RESULTING IN MUCAPES IN THE RANGE OF 1000 TO 1500 J/KG. THIS...COMBINED WITH 30 TO 40 KTS OF SURFACE TO 6 KM SPEED SHEAR WITH VEERING PROFILES... MAY BE FAVORABLE FOR A FEW LOW END SEVERE STORMS...ESPECIALLY ALONG AND EAST OF THE MS RIVER IN THE AFTERNOON...AND THE CURRENT SPC DAY 3 OUTLOOK HAS A SLIGHT RISK OVER OUR SE COUNTIES. ANTICIPATED COVERAGE OF SHOWERS AND THUNDERSTORMS SUPPORTS POPS IN A 30 TO 40 PERCENT RANGE. THE BACK EDGE OF ANY SHOWERS ALONG TO BEHIND THE FRONT MAY BE ON-GOING AT 00Z OVER THE FAR EAST AND WILL KEEP SLIGHT CHANCES GOING THERE INTO TUE EVENING. UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE PROVIDES DRY WEATHER WITH TEMPERATURES STILL ROUGHLY 10 DEGREES ABOVE NORMAL FOR WED INTO THU. WED NIGHT MAY SEE LOWS IN THE UPPER 30S IN THE FAR NORTH AS THE RIDGE AXIS PASSES OVERHEAD. THE COLDEST MOS GUIDANCE...THE MEN FROM THE 00Z RUN...INDICATES POCKETS OF MID 30S OVER EAST CENTRAL IA INTO NW IL. WILL CONTINUE TO WATCH THIS TREND...BUT HAVE KEPT TEMPERATURES CLOSER TO A CONSENSUS FOR NOW WITH MINS FROM THE UPPER 30S ALONG THE HIGHWAY 20 CORRIDOR TO THE MID 40S ACROSS THE SOUTH. POPS RETURN TO THE FORECAST FOR RAIN AND THUNDERSTORM CHANCES THU NIGHT INTO FRIDAY AS A WEAK SHORTWAVE TROUGH IS SHOWN SENDING A WEAK SURFACE LOW THROUGH KS TO CENTRAL IL. FORECAST CONFIDENCE REMAINS LOW BEYOND AS THERE CONTINUE TO BE SIGNIFICANT DIFFERENCES IN HOW THE MEDIUM RANGE MODELS HANDLE ENSUING SHORTWAVES...RESULTING IN AN EXTENDED PERIOD OF LOW END CHANCE POPS FRIDAY THROUGH SUNDAY THAT WILL LIKELY BECOME DEFINED IN LATER FORECASTS. ..SHEETS.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
846 PM MDT SUN MAR 25 2012 .UPDATE... ISSUED AT 836 PM MDT SUN MAR 25 2012 JUST COMPLETED ANOTHER UPDATE. BASED ON CURRENT SATELLITE AND EXPECTED MID/UPPER LEVEL CLOUD COVER AND LOW LEVEL STRATUS...INCREASED CLOUD COVER ONCE AGAIN. ALSO DEWPOINTS ARE RUNNING HIGHER THAN CURRENTLY PROGGED. LOOKS LIKE WINDS WILL SHIFT UNTIL LATER IN THE NIGHT PER THE RUC WHICH HAS A GOOD HANDLE ON THE CURRENT WIND AND DEWPOINT FIELD...ALTHOUGH NOT AS GOOD ON THE DEWPOINTS. SO USED IT FOR THE BASIS OF THE UPDATE. AS A RESULT OF A LONGER PERIOD OF EASTERLY FLOW AND HIGHER DEWPOINTS...INCREASED COVERAGE OF FOG ONCE AGAIN TO AREAS OVER THE NORTHERN PORTION OF THE AREA. AT THIS TIME BASED ON THE THICK MID/UPPER LEVEL CLOUD COVER...DO NOT EXPECT THE FOG TO BECOME DENSE BUT THIS WILL NEED CONTINUED MONITORING. UPDATE ISSUED AT 546 PM MDT SUN MAR 25 2012 JUST COMPLETED A MINOR UPDATE. A GREAT DEAL OF MID/HIGH LEVEL CLOUD COVER MOVING OVER THE AREA IN ADVANCE OF WESTERN UPPER TROUGH. MOISTURE PROGS WOULD INDICATE THAT THIS CLOUD COVER WILL STAY AS THICK AS IT IS NOW OR GET THICKER. SO INCREASED CLOUD COVER THROUGH THE NIGHT. BASED ON LATEST OBSERVATIONS AND MODEL DATA...EXPANDED THE PATCHY FOG AREA TO THE NORTH AND WEST. EVEN THOUGH LOW LEVEL MOISTURE LOOKS TO BE GREATER THAN LAST NIGHT... THE HIGHER LEVEL CLOUD COVER AND INCREASE/VEERING OF THE WIND OVERNIGHT SHOULD LIMIT THE COVERAGE OF THE FOG AND CHANCES THAT IT WILL BE DENSE. WILL CONTINUE TO CLOSELY WATCH TRENDS ON THIS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 308 PM MDT SUN MAR 25 2012 MOIST AIR MASS CONTINUES TO RESIDE OVER THE TRI-STATE REGION THIS AFTERNOON AHEAD OF A TROUGH WHICH IS CURRENTLY SITUATED OVER THE PACIFIC COAST. PRIMARY QUESTION FOR TONIGHT IS WHETHER FOG WILL REFORM ACROSS THE AREA. GUIDANCE IS DEPICTING ANYTHING BUT A CONSENSUS WITH RUC MORE WIDESPREAD THAN MOST OTHER GUIDANCE. WILL CONTINUE WITH PATCHY FOG MENTION OVER THE NORTHEAST BUT EVENING SHIFT WILL NEED TO MONITOR SITUATION CLOSELY. FOCUS THEN SHIFTS TO AN ACTIVE WEATHER DAY ON MONDAY WITH A MULTITUDE OF HAZARDS POSSIBLE ACROSS THE AREA. CONFIDENCE IN CRITICAL FIRE WEATHER CONDITIONS IS HIGHEST ACROSS EASTERN COLORADO. SEE FIRE WEATHER SECTION BELOW FOR FURTHER DISCUSSION ON THAT POTENTIAL. WESTERN CONUS TROUGH WILL BEGIN TO TRANSLATE EASTWARD WITH A SHORTWAVE TROUGH LIFTING NORTHEASTWARD INTO THE WESTERN DAKOTAS BY MONDAY EVENING. A DRYLINE WILL BECOME ESTABLISHED OVER EASTERN COLORADO DURING THE LATE MORNING HOURS BUT DOES NOT REALLY MIX EAST OF THE CO/KS BORDER UNTIL LATE MONDAY EVENING. PRESSURE GRADIENT WILL TIGHTEN RAPIDLY AS THE LOW BEGINS TO DEEPEN RESULTING IN ADVISORY CRITERIA WINDS ACROSS THE ENTIRE FORECAST AREA DURING THE AFTERNOON AND EARLY EVENING. HAVE GONE AHEAD AND EXPANDED THE GOING WIND ADVISORY FOR THIS LIKELIHOOD. IN ADDITION TO FIRE WEATHER AND WIND CONCERNS...ALSO HAVE A SMALL CHANCE FOR THUNDERSTORMS TO DEVELOP PRIMARILY ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA. STRONGEST DYNAMIC REMAIN NORTH OF THE FORECAST AREA BUT ENOUGH FORCING FOR ASCENT SHOULD BE OBSERVED FOR A FEW HOUR WINDOW. NOT COMPLETELY CONFIDENT THAT CONVECTION WILL DEVELOP BUT THE ENVIRONMENT WOULD BE SUPPORTIVE OF STRONG THUNDERSTORMS IF AN UPDRAFT CAN DEVELOP AND BE SUSTAINED. A COLD FRONT SWEEPS THROUGH THE AREA BETWEEN 00Z AND 06Z. MAY HAVE A BRIEF PERIOD OF GUSTY NORTHWESTERLY WINDS BEHIND THE FRONT GIVEN ANTICIPATED 6 HOUR PRESSURE RISES AS PROGGED BY BOTH THE NAM AND GFS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 308 PM MDT SUN MAR 25 2012 DRY CONDITIONS AND A CONTINUATION OF MUCH ABOVE NORMAL TEMPERATURES WILL CONTINUE FROM TUESDAY THROUGH EARLY THURSDAY AS A BROAD MID/UPPER RIDGE BUILDS BACK ACROSS THE CENTRAL HIGH PLAINS. BY THURSDAY AFTERNOON...FORCING FOR ASCENT ASSOCIATED WITH A SHORTWAVE TROUGH TRANSLATING ACROSS THE DAKOTAS COULD PROVIDE ENOUGH LIFT TO GENERATE CONVECTION ACROSS PRIMARILY NORTHEASTERN PORTIONS OF THE TRI-STATE REGION. ADDITIONAL WEAK SHORTWAVE TROUGHS PASS THROUGH THE AREA THURSDAY NIGHT AND FRIDAY WITH A CONTINUED FOCUS ON EASTERN PORTIONS OF THE AREA. DRY CONDITIONS WILL RETURN FOR THE WEEKEND WITH AFTERNOON TEMPS IN THE MID TO UPPER 70S CONTINUING. SIGNIFICANT FORECAST UNCERTAINTY DEVELOPS BY SUNDAY WITH THE OPERATIONAL GFS/GEFS MEAN AND EC DEPICTING STARKLY DIFFERENT SCENARIOS. THE GFS ATTEMPTS TO DEVELOP A DEEP TROUGH ACROSS THE GREAT BASIN/INTERMOUNTAIN WEST WHILE THE EC SUPPORTS A RIDGE OVER THE SAME GENERAL AREA AND HOLDS THE TROUGH OVER THE PACIFIC NORTHWEST. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 520 PM MDT SUN MAR 25 2012 MID/HIGH CLOUDS WILL BE PLENTIFUL THROUGH THE PERIOD AS AN UPPER LEVEL TROUGH CONTINUES TO APPROACH THE REGION. THERE IS A CHANCE FOR SLIGHT REDUCTIONS IN VISIBILITY AT KMCK OVERNIGHT WITH SOUTHEASTERLY LOW LEVEL FLOW SO HAVE PLACED 5SM IN TAF FROM 10-15Z. ON MONDAY...WINDS WILL BECOME GUSTY FROM THE SOUTH AS A LEE TROUGH STRENGTHENS THROUGH THE DAY. WINDS COULD REACH UP TO 35-40 KNOTS AT TIMES. && .FIRE WEATHER... ISSUED AT 308 PM MDT SUN MAR 25 2012 HAVE GONE AHEAD AND UPGRADED THE THREE EASTERN COLORADO COUNTIES TO A RED FLAG WARNING FOR MONDAY. LEFT THE FIRE WEATHER WATCH INTACT FOR THE FIRST TIER OF KANSAS AND NEBRASKA COUNTIES AS THERE IS SIGNIFICANT UNCERTAINTY WITH REGARD TO JUST HOW FAR EAST THE DRYLINE WILL MIX DURING THE AFTERNOON. OPTED TO CANCEL THE FIRE WEATHER WATCH FOR THE NEXT TIER OF COUNTIES TO THE EAST AS CONFIDENCE WAS TOO LOW THAT CRITERIA WOULD BE MET IN THESE LOCATIONS. && .CLIMATE... ISSUED AT 308 PM MDT SUN MAR 25 2012 STILL LOOKING AT THE POTENTIAL FOR A FEW RECORDS ACROSS THE TRI- STATE REGION ON MONDAY. ALSO STILL WELL ON TRACK FOR THE WARMEST MARCH ON RECORD AT GOODLAND...BURLINGTON...AND MCCOOK. HERE ARE THE LATEST FIGURES THROUGH MARCH 24. GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.6 BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 47.1 MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.9 HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 51.1 WITH MUCH ABOVE NORMAL TEMPERATURES PROJECTED TO CONTINUE THROUGH THE END OF THE MONTH...CONFIDENCE IS VERY HIGH THAT GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON RECORD. IT REMAINS TO BE SEE IF HILL CITY WILL BREAK THE RECORD AS WELL. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...WIND ADVISORY FROM NOON TO 9 PM MDT MONDAY FOR COZ090>092. RED FLAG WARNING FROM NOON TO 9 PM MDT MONDAY FOR COZ252>254. KS...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR KSZ001-013-027-041. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TO 9 PM MDT /10 PM CDT/ MONDAY FOR KSZ001>004-013>016-027>029-041-042. NE...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR NEZ079. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TO 9 PM MDT /10 PM CDT/ MONDAY FOR NEZ079>081. && $$ UPDATE...BULLER SHORT TERM...PMM/FOLTZ LONG TERM....FOLTZ AVIATION...BAS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
552 PM MDT SUN MAR 25 2012 .UPDATE... ISSUED AT 546 PM MDT SUN MAR 25 2012 JUST COMPLETED A MINOR UPDATE. A GREAT DEAL OF MID/HIGH LEVEL CLOUD COVER MOVING OVER THE AREA IN ADVANCE OF WESTERN UPPER TROUGH. MOISTURE PROGS WOULD INDICATE THAT THIS CLOUD COVER WILL STAY AS THICK AS IT IS NOW OR GET THICKER. SO INCREASED CLOUD COVER THROUGH THE NIGHT. BASED ON LATEST OBSERVATIONS AND MODEL DATA...EXPANDED THE PATCHY FOG AREA TO THE NORTH AND WEST. EVEN THOUGH LOW LEVEL MOISTURE LOOKS TO BE GREATER THAN LAST NIGHT... THE HIGHER LEVEL CLOUD COVER AND INCREASE/VEERING OF THE WIND OVERNIGHT SHOULD LIMIT THE COVERAGE OF THE FOG AND CHANCES THAT IT WILL BE DENSE. WILL CONTINUE TO CLOSELY WATCH TRENDS ON THIS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 308 PM MDT SUN MAR 25 2012 MOIST AIR MASS CONTINUES TO RESIDE OVER THE TRI-STATE REGION THIS AFTERNOON AHEAD OF A TROUGH WHICH IS CURRENTLY SITUATED OVER THE PACIFIC COAST. PRIMARY QUESTION FOR TONIGHT IS WHETHER FOG WILL REFORM ACROSS THE AREA. GUIDANCE IS DEPICTING ANYTHING BUT A CONSENSUS WITH RUC MORE WIDESPREAD THAN MOST OTHER GUIDANCE. WILL CONTINUE WITH PATCHY FOG MENTION OVER THE NORTHEAST BUT EVENING SHIFT WILL NEED TO MONITOR SITUATION CLOSELY. FOCUS THEN SHIFTS TO AN ACTIVE WEATHER DAY ON MONDAY WITH A MULTITUDE OF HAZARDS POSSIBLE ACROSS THE AREA. CONFIDENCE IN CRITICAL FIRE WEATHER CONDITIONS IS HIGHEST ACROSS EASTERN COLORADO. SEE FIRE WEATHER SECTION BELOW FOR FURTHER DISCUSSION ON THAT POTENTIAL. WESTERN CONUS TROUGH WILL BEGIN TO TRANSLATE EASTWARD WITH A SHORTWAVE TROUGH LIFTING NORTHEASTWARD INTO THE WESTERN DAKOTAS BY MONDAY EVENING. A DRYLINE WILL BECOME ESTABLISHED OVER EASTERN COLORADO DURING THE LATE MORNING HOURS BUT DOES NOT REALLY MIX EAST OF THE CO/KS BORDER UNTIL LATE MONDAY EVENING. PRESSURE GRADIENT WILL TIGHTEN RAPIDLY AS THE LOW BEGINS TO DEEPEN RESULTING IN ADVISORY CRITERIA WINDS ACROSS THE ENTIRE FORECAST AREA DURING THE AFTERNOON AND EARLY EVENING. HAVE GONE AHEAD AND EXPANDED THE GOING WIND ADVISORY FOR THIS LIKELIHOOD. IN ADDITION TO FIRE WEATHER AND WIND CONCERNS...ALSO HAVE A SMALL CHANCE FOR THUNDERSTORMS TO DEVELOP PRIMARILY ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA. STRONGEST DYNAMIC REMAIN NORTH OF THE FORECAST AREA BUT ENOUGH FORCING FOR ASCENT SHOULD BE OBSERVED FOR A FEW HOUR WINDOW. NOT COMPLETELY CONFIDENT THAT CONVECTION WILL DEVELOP BUT THE ENVIRONMENT WOULD BE SUPPORTIVE OF STRONG THUNDERSTORMS IF AN UPDRAFT CAN DEVELOP AND BE SUSTAINED. A COLD FRONT SWEEPS THROUGH THE AREA BETWEEN 00Z AND 06Z. MAY HAVE A BRIEF PERIOD OF GUSTY NORTHWESTERLY WINDS BEHIND THE FRONT GIVEN ANTICIPATED 6 HOUR PRESSURE RISES AS PROGGED BY BOTH THE NAM AND GFS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 308 PM MDT SUN MAR 25 2012 DRY CONDITIONS AND A CONTINUATION OF MUCH ABOVE NORMAL TEMPERATURES WILL CONTINUE FROM TUESDAY THROUGH EARLY THURSDAY AS A BROAD MID/UPPER RIDGE BUILDS BACK ACROSS THE CENTRAL HIGH PLAINS. BY THURSDAY AFTERNOON...FORCING FOR ASCENT ASSOCIATED WITH A SHORTWAVE TROUGH TRANSLATING ACROSS THE DAKOTAS COULD PROVIDE ENOUGH LIFT TO GENERATE CONVECTION ACROSS PRIMARILY NORTHEASTERN PORTIONS OF THE TRI-STATE REGION. ADDITIONAL WEAK SHORTWAVE TROUGHS PASS THROUGH THE AREA THURSDAY NIGHT AND FRIDAY WITH A CONTINUED FOCUS ON EASTERN PORTIONS OF THE AREA. DRY CONDITIONS WILL RETURN FOR THE WEEKEND WITH AFTERNOON TEMPS IN THE MID TO UPPER 70S CONTINUING. SIGNIFICANT FORECAST UNCERTAINTY DEVELOPS BY SUNDAY WITH THE OPERATIONAL GFS/GEFS MEAN AND EC DEPICTING STARKLY DIFFERENT SCENARIOS. THE GFS ATTEMPTS TO DEVELOP A DEEP TROUGH ACROSS THE GREAT BASIN/INTERMOUNTAIN WEST WHILE THE EC SUPPORTS A RIDGE OVER THE SAME GENERAL AREA AND HOLDS THE TROUGH OVER THE PACIFIC NORTHWEST. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 520 PM MDT SUN MAR 25 2012 MID/HIGH CLOUDS WILL BE PLENTIFUL THROUGH THE PERIOD AS AN UPPER LEVEL TROUGH CONTINUES TO APPROACH THE REGION. THERE IS A CHANCE FOR SLIGHT REDUCTIONS IN VISIBILITY AT KMCK OVERNIGHT WITH SOUTHEASTERLY LOW LEVEL FLOW SO HAVE PLACED 5SM IN TAF FROM 10-15Z. ON MONDAY...WINDS WILL BECOME GUSTY FROM THE SOUTH AS A LEE TROUGH STRENGTHENS THROUGH THE DAY. WINDS COULD REACH UP TO 35-40 KNOTS AT TIMES. && .FIRE WEATHER... ISSUED AT 308 PM MDT SUN MAR 25 2012 HAVE GONE AHEAD AND UPGRADED THE THREE EASTERN COLORADO COUNTIES TO A RED FLAG WARNING FOR MONDAY. LEFT THE FIRE WEATHER WATCH INTACT FOR THE FIRST TIER OF KANSAS AND NEBRASKA COUNTIES AS THERE IS SIGNIFICANT UNCERTAINTY WITH REGARD TO JUST HOW FAR EAST THE DRYLINE WILL MIX DURING THE AFTERNOON. OPTED TO CANCEL THE FIRE WEATHER WATCH FOR THE NEXT TIER OF COUNTIES TO THE EAST AS CONFIDENCE WAS TOO LOW THAT CRITERIA WOULD BE MET IN THESE LOCATIONS. && .CLIMATE... ISSUED AT 308 PM MDT SUN MAR 25 2012 STILL LOOKING AT THE POTENTIAL FOR A FEW RECORDS ACROSS THE TRI- STATE REGION ON MONDAY. ALSO STILL WELL ON TRACK FOR THE WARMEST MARCH ON RECORD AT GOODLAND...BURLINGTON...AND MCCOOK. HERE ARE THE LATEST FIGURES THROUGH MARCH 24. GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.6 BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 47.1 MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.9 HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 51.1 WITH MUCH ABOVE NORMAL TEMPERATURES PROJECTED TO CONTINUE THROUGH THE END OF THE MONTH...CONFIDENCE IS VERY HIGH THAT GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON RECORD. IT REMAINS TO BE SEE IF HILL CITY WILL BREAK THE RECORD AS WELL. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...WIND ADVISORY FROM NOON TO 9 PM MDT MONDAY FOR COZ090>092. RED FLAG WARNING FROM NOON TO 9 PM MDT MONDAY FOR COZ252>254. KS...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR KSZ001-013-027-041. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TO 9 PM MDT /10 PM CDT/ MONDAY FOR KSZ001>004-013>016-027>029-041-042. NE...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR NEZ079. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TO 9 PM MDT /10 PM CDT/ MONDAY FOR NEZ079>081. && $$ UPDATE...BULLER SHORT TERM...PMM/FOLTZ LONG TERM....FOLTZ AVIATION...BAS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
520 PM MDT SUN MAR 25 2012 .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 308 PM MDT SUN MAR 25 2012 MOIST AIR MASS CONTINUES TO RESIDE OVER THE TRI-STATE REGION THIS AFTERNOON AHEAD OF A TROUGH WHICH IS CURRENTLY SITUATED OVER THE PACIFIC COAST. PRIMARY QUESTION FOR TONIGHT IS WHETHER FOG WILL REFORM ACROSS THE AREA. GUIDANCE IS DEPICTING ANYTHING BUT A CONSENSUS WITH RUC MORE WIDESPREAD THAN MOST OTHER GUIDANCE. WILL CONTINUE WITH PATCHY FOG MENTION OVER THE NORTHEAST BUT EVENING SHIFT WILL NEED TO MONITOR SITUATION CLOSELY. FOCUS THEN SHIFTS TO AN ACTIVE WEATHER DAY ON MONDAY WITH A MULTITUDE OF HAZARDS POSSIBLE ACROSS THE AREA. CONFIDENCE IN CRITICAL FIRE WEATHER CONDITIONS IS HIGHEST ACROSS EASTERN COLORADO. SEE FIRE WEATHER SECTION BELOW FOR FURTHER DISCUSSION ON THAT POTENTIAL. WESTERN CONUS TROUGH WILL BEGIN TO TRANSLATE EASTWARD WITH A SHORTWAVE TROUGH LIFTING NORTHEASTWARD INTO THE WESTERN DAKOTAS BY MONDAY EVENING. A DRYLINE WILL BECOME ESTABLISHED OVER EASTERN COLORADO DURING THE LATE MORNING HOURS BUT DOES NOT REALLY MIX EAST OF THE CO/KS BORDER UNTIL LATE MONDAY EVENING. PRESSURE GRADIENT WILL TIGHTEN RAPIDLY AS THE LOW BEGINS TO DEEPEN RESULTING IN ADVISORY CRITERIA WINDS ACROSS THE ENTIRE FORECAST AREA DURING THE AFTERNOON AND EARLY EVENING. HAVE GONE AHEAD AND EXPANDED THE GOING WIND ADVISORY FOR THIS LIKELIHOOD. IN ADDITION TO FIRE WEATHER AND WIND CONCERNS...ALSO HAVE A SMALL CHANCE FOR THUNDERSTORMS TO DEVELOP PRIMARILY ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA. STRONGEST DYNAMIC REMAIN NORTH OF THE FORECAST AREA BUT ENOUGH FORCING FOR ASCENT SHOULD BE OBSERVED FOR A FEW HOUR WINDOW. NOT COMPLETELY CONFIDENT THAT CONVECTION WILL DEVELOP BUT THE ENVIRONMENT WOULD BE SUPPORTIVE OF STRONG THUNDERSTORMS IF AN UPDRAFT CAN DEVELOP AND BE SUSTAINED. A COLD FRONT SWEEPS THROUGH THE AREA BETWEEN 00Z AND 06Z. MAY HAVE A BRIEF PERIOD OF GUSTY NORTHWESTERLY WINDS BEHIND THE FRONT GIVEN ANTICIPATED 6 HOUR PRESSURE RISES AS PROGGED BY BOTH THE NAM AND GFS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 308 PM MDT SUN MAR 25 2012 DRY CONDITIONS AND A CONTINUATION OF MUCH ABOVE NORMAL TEMPERATURES WILL CONTINUE FROM TUESDAY THROUGH EARLY THURSDAY AS A BROAD MID/UPPER RIDGE BUILDS BACK ACROSS THE CENTRAL HIGH PLAINS. BY THURSDAY AFTERNOON...FORCING FOR ASCENT ASSOCIATED WITH A SHORTWAVE TROUGH TRANSLATING ACROSS THE DAKOTAS COULD PROVIDE ENOUGH LIFT TO GENERATE CONVECTION ACROSS PRIMARILY NORTHEASTERN PORTIONS OF THE TRI-STATE REGION. ADDITIONAL WEAK SHORTWAVE TROUGHS PASS THROUGH THE AREA THURSDAY NIGHT AND FRIDAY WITH A CONTINUED FOCUS ON EASTERN PORTIONS OF THE AREA. DRY CONDITIONS WILL RETURN FOR THE WEEKEND WITH AFTERNOON TEMPS IN THE MID TO UPPER 70S CONTINUING. SIGNIFICANT FORECAST UNCERTAINTY DEVELOPS BY SUNDAY WITH THE OPERATIONAL GFS/GEFS MEAN AND EC DEPICTING STARKLY DIFFERENT SCENARIOS. THE GFS ATTEMPTS TO DEVELOP A DEEP TROUGH ACROSS THE GREAT BASIN/INTERMOUNTAIN WEST WHILE THE EC SUPPORTS A RIDGE OVER THE SAME GENERAL AREA AND HOLDS THE TROUGH OVER THE PACIFIC NORTHWEST. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 520 PM MDT SUN MAR 25 2012 MID/HIGH CLOUDS WILL BE PLENTIFUL THROUGH THE PERIOD AS AN UPPER LEVEL TROUGH CONTINUES TO APPROACH THE REGION. THERE IS A CHANCE FOR SLIGHT REDUCTIONS IN VISIBILITY AT KMCK OVERNIGHT WITH SOUTHEASTERLY LOW LEVEL FLOW SO HAVE PLACED 5SM IN TAF FROM 10-15Z. ON MONDAY...WINDS WILL BECOME GUSTY FROM THE SOUTH AS A LEE TROUGH STRENGTHENS THROUGH THE DAY. WINDS COULD REACH UP TO 35-40 KNOTS AT TIMES. && .FIRE WEATHER... ISSUED AT 308 PM MDT SUN MAR 25 2012 HAVE GONE AHEAD AND UPGRADED THE THREE EASTERN COLORADO COUNTIES TO A RED FLAG WARNING FOR MONDAY. LEFT THE FIRE WEATHER WATCH INTACT FOR THE FIRST TIER OF KANSAS AND NEBRASKA COUNTIES AS THERE IS SIGNIFICANT UNCERTAINTY WITH REGARD TO JUST HOW FAR EAST THE DRYLINE WILL MIX DURING THE AFTERNOON. OPTED TO CANCEL THE FIRE WEATHER WATCH FOR THE NEXT TIER OF COUNTIES TO THE EAST AS CONFIDENCE WAS TOO LOW THAT CRITERIA WOULD BE MET IN THESE LOCATIONS. && .CLIMATE... ISSUED AT 308 PM MDT SUN MAR 25 2012 STILL LOOKING AT THE POTENTIAL FOR A FEW RECORDS ACROSS THE TRI- STATE REGION ON MONDAY. ALSO STILL WELL ON TRACK FOR THE WARMEST MARCH ON RECORD AT GOODLAND...BURLINGTON...AND MCCOOK. HERE ARE THE LATEST FIGURES THROUGH MARCH 24. GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.6 BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 47.1 MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.9 HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 51.1 WITH MUCH ABOVE NORMAL TEMPERATURES PROJECTED TO CONTINUE THROUGH THE END OF THE MONTH...CONFIDENCE IS VERY HIGH THAT GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON RECORD. IT REMAINS TO BE SEE IF HILL CITY WILL BREAK THE RECORD AS WELL. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...WIND ADVISORY FROM NOON TO 9 PM MDT MONDAY FOR COZ090>092. RED FLAG WARNING FROM NOON TO 9 PM MDT MONDAY FOR COZ252>254. KS...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR KSZ001-013-027-041. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TO 9 PM MDT /10 PM CDT/ MONDAY FOR KSZ001>004-013>016-027>029-041-042. NE...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR NEZ079. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TO 9 PM MDT /10 PM CDT/ MONDAY FOR NEZ079>081. && $$ UPDATE...PMM SHORT TERM...PMM/FOLTZ LONG TERM....FOLTZ AVIATION...BAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
1050 PM EDT SUN MAR 25 2012 .UPDATE... ISSUED AT 1050 PM EDT SUN MAR 25 2012 CLOUD DECK AROUND 4K AGL FEET CURRENTLY ADVECTING SOUTH ACROSS THE FORECAST AREA PER LATEST SATELLITE IMAGERY. BACK EDGE OF THIS CLOUD DECK WILL CLEAR THE NORTHERN PART OF FORECAST AREA BY MIDNIGHT. HOWEVER...WITH CONTINUED NORTHERLY FLOW AND LOW LEVEL MOISTURE AVAILABLE EXPECT UPSLOPE FLOW TO KEEP CLOUDS IN THE SOUTHEAST PART OF FORECAST AREA FOR MOST OF THE NIGHT. THIS IDEA IS SUPPORTED BY LATEST RUC GUIDANCE. HAVE UPDATED NDFD AND ASSOCIATED PRODUCTS PER LATEST SATELLITE AND OBSERVATIONAL DATA. UPDATE ISSUED AT 759 PM EDT SUN MAR 25 2012 THE LAST ISOLATED SHOWERS DISSIPATED OR MOVED OUT OF THE AREA AROUND 730 PM EDT...SO HAVE REMOVED ALL PRECIPITATION FROM THE NDFD AND ASSOCIATED PRODUCTS FOR THE OVERNIGHT PERIOD. ALSO MADE SOME MINOR UPDATES BASED ON LATEST OBSERVATIONAL TRENDS. THE MAIN FORECAST ISSUE IS HOW MUCH CLOUDINESS THERE WILL BE OVERNIGHT. THERE IS CONSIDERABLE LOW CLOUDINESS UPSTREAM OF THE AREA...AND LATEST NAM AND RUC GUIDANCE SHOW CONSIDERABLE LOW LEVEL MOISTURE...MAINLY BELOW 850 MB TO BE OVER THE AREA TONIGHT. WITH NORTHERLY FLOW EXPECT CLOUDINESS TO INCREASE IN COVERAGE DURING THE NIGHT...WITH MOSTLY CLOUDY SKIES BEING THE RESULT. UPDATE ISSUED AT 423 PM EDT SUN MAR 25 2012 BASED ON RADAR TRENDS ISOLATED TO SCATTERED SHOWERS WILL AFFECT FAR EASTERN KENTUCKY THROUGH 23Z. THIS IS CURRENTLY WELL DEPICTED IN NDFD. ONLY SOME MINOR NDFD UPDATES WERE MADE BASED ON LATEST SATELLITE AND SURFACE OBSERVATIONAL TRENDS. && .SHORT TERM...(LATE THIS AFTERNOON THROUGH TUESDAY) ISSUED AT 310 PM EDT SUN MAR 25 2012 UPPER LEVEL LOW WILL CONTINUE TO PULL AWAY FROM THE AREA TONIGHT GIVING WAY TO UPPER LEVEL RIDGING THROUGH THE REMAINDER OF THE PERIOD. THE UPPER LOW WILL REMAIN CLOSE ENOUGH TO KEEP A MENTION OF A FEW SHOWERS IN THE FORECAST FOR MOST AREAS LATE THIS AFTERNOON... WITH THE CHANCE OF SHOWERS LINGERING ACROSS THE TIP OF FAR EAST KENTUCKY THIS EVENING. IT APPEARS THAT INSTABILITY WILL NOT BE SUFFICIENT TO PRODUCE A TSTORM THIS FAR WEST SO REMOVED THAT MENTION FOR THIS AFTERNOON AND EVENING. A COLD FRONT WILL THEN DROP IN FROM THE NORTH LATE TONIGHT KEEPING A LIGHT BREEZE BLOWING FOR MOST LOCATIONS. MOISTURE POOLING ALONG THIS BOUNDARY IN CONJUNCTION WITH THE LIGHT NORTHEAST LOW LEVEL FLOW WILL LIKELY RESULT IN QUITE A BIT OF STRATUS DEVELOPING OVERNIGHT WITH MAYBE EVEN A LITTLE DRIZZLE. ANY CLOUD COVER SHOULD DISSOLVE BY MIDDAY MONDAY AS HIGH PRESSURE BEGINS TO BUILD DOWN INTO THE OHIO VALLEY ACCOMPANIED BY A MUCH DRIER AIRMASS. IN FACT...DEWPOINTS ARE PROGGED TO DROP INTO THE 20S OVER NORTHEAST KENTUCKY LATE MONDAY NIGHT AND THERE IS A CONCERN THAT TEMPERATURES WILL RESPOND TO THIS DRY AIR AND DROP LOW ENOUGH TO THREATEN A FROST OR FREEZE FOR SOME AREAS. CONFIDENCE IS NOT HIGH ENOUGH TO HOIST ANY HEADLINES AT THIS TIME THOUGH AS MODELS INDICATE THE POTENTIAL FOR SOME HIGH LEVEL CLOUDINESS TO MOVE IN OVERNIGHT AND POINT TO THERE BEING JUST ENOUGH WIND TO KEEP ANY FROST FORMATION ISOLATED AND CONFINED TO THE DEEPEST VALLEYS BASICALLY NORTH AND EAST OF JKL. HIGH PRESSURE WILL REMAIN IN CONTROL ON TUESDAY BUT HIGH LEVEL CLOUDS WILL BE ON THE INCREASE IN ADVANCE OF OUR NEXT WEATHER MAKER. TEMPS ARE TRICKY...VARYING 10 TO 15 DEGREES BETWEEN THE GFS AND NAM MOS AT ANY GIVEN POINT. TEND TO AGREE MORE WITH THE GFS NUMBERS WITH THE UPPER LEVEL RIDGE BUILDING IN AND WILL FORECAST HIGHS APPROACHING OR EXCEEDING 70 FOR MOST LOCATIONS. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 310 PM EDT SUN MAR 25 2012 MODELS CONTINUE TO DISPLAY GOOD CONTINUITY THRU MOST OF THE WORK WEEK BUT BEGIN TO DIVERGE RATHER SHARPLY ON FRIDAY WITH THE LONG WAVE PATTERN. HAVE GENERALLY FOLLOWED A BLEND OF THE MEDIUM RANGE OPERATIONAL/ENSEMBLE GUIDANCE THRU THE FIRST HALF OF THE PERIOD BEFORE GIVING MORE CREDENCE TO THE LESS EXTREME SOLUTION OF THE GFS OVER THE WEEKEND...THOUGH CONFIDENCE WITH THE DETAILS TOWARDS THE TAIL END OF THE PERIOD REMAINS RATHER LOW. VORTEX CURRENTLY MAKING LANDFALL ALONG THE CA/OR COAST IS EXPECTED TO SEND A DECENT SHORT WAVE OVER THE ROCKIES AND ACROSS THE NRN PLAINS BEFORE REACHING THE UPPER MIDWEST BY TUESDAY NIGHT TO START THE PERIOD. AS THIS WAVE CONTINUES TO PUSH EAST ALONG THE CANADIAN BORDER...THE COLD FRONT ASSOCIATED WITH THE SFC REFLECTION LOOKS TO SWEEP ACROSS THE OHIO RIVER AND INTO ERN KY ON WEDNESDAY...WITH ENOUGH INSTABILITY STILL ADVERTISED IN FCST SOUNDINGS AROUND THE AREA TO WARRANT CHANCES OF THUNDER FOR WEDNESDAY. GIVEN THE PROGRESSIVE NATURE OF THE PATTERN...WOULD PREFER TO GO MOSTLY QUIET BY WEDNESDAY NIGHT BUT WILL SETTLE FOR A GENTLE NUDGE IN THAT DIRECTION FOR THE MOMENT. CANADIAN HIGH PRESSURE BUILDS DOWN ACROSS THE GREAT LAKES AND INTO THE OHIO VALLEY ON THURSDAY...BRINGING ANOTHER BOUT OF BENIGN WEATHER THROUGH FRIDAY...AT WHICH POINT THE MODELS BEGIN PARTING WAYS WITH THEIR DEPICTION OF THE UPPER LEVEL FEATURES. REGARDLESS OF THEIR RESPECTIVE DIFFERENCES...ANY OF THE RECENT OFFINGS FROM THE GUIDANCE WOULD POINT TOWARDS AN UNSETTLED PATTERN PERSISTING THROUGH THE WEEKEND WITH PERIODS OF RAIN POSSIBLE AND A FEW THUNDERSTORMS NOT ENTIRELY OUT OF THE QUESTION. AT THIS TIME...WILL KEEP POPS IN THE LOW END CHANCE RANGE UNTIL A BETTER CONSENSUS CAN BE OBTAINED. TEMPERATURES OVER THE COURSE OF THE PERIOD LOOK TO CONTINUE FOLLOWING THE ABOVE NORMAL TREND...WITH TEMPS EARLY IN THE PERIOD STILL RUNNING WELL ABOVE NORMAL BEFORE TRENDING TOWARDS CLIMO BY THE BEGINNING OF NEXT WEEK. ONE NOTE OF CONCERN IS FOR THURSDAY NIGHT INTO FRIDAY MORNING WHERE AGAIN...MODELS POINT TOWARDS RELATIVELY CLEAR SKIES AND LIGHT WINDS WITH DEWPTS IN THE UPPER 20S AND LOWER 30S THROUGHOUT OUR NERN VALLEYS. HAVE STRAYED TOWARDS THE COOLER SIDE OF THE MOS LOWS FOR NOW AND...GIVEN THE EVOLVING UNCERTAINTY JUST BEYOND THIS WINDOW...WILL CONTINUE TO KEEP A CLOSE EYE ON THESE NUMBERS OVER THE NEXT FEW DAYS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 759 PM EDT SUN MAR 25 2012 MAIN ISSUE OF CONCERN FOR THIS FORECAST PERIOD IS THE MOVEMENT OF LOW CLOUD INTO THE AREA OR THE DEVELOPMENT OF LOW CLOUD ACROSS THE FORECAST AREA FOR TONIGHT. THERE IS CONSIDERABLE LOW LEVEL CLOUDINESS TO THE NORTH OF THE FORECAST AREA AT 2330Z. WITH THE NORTHERLY FLOW THIS WILL MOVE INTO THE AREA THIS EVENING. ALSO...WITH PLENTY OF MOISTURE BELOW 850 MB AND NORTHERLY WINDS ALSO LOOK FOR LOW CLOUD TO DEVELOP IN UPSLOPE FLOW. EXPECT MVFR CEILINGS TO MOVE INTO OR DEVELOP ACROSS THE FORECAST AREA THIS EVENING...AFFECTING THE TAF SITES AFTER 04Z. MVFR CEILINGS SHOULD THEN PREVAIL ACROSS MUCH OF THE AREA THROUGH 12Z...WITH CEILINGS LIFTING AND SKY COVER SCATTERING OUT ON MONDAY. VFR CONDITIONS WILL PREVAIL ACROSS THE AREA MONDAY AFTERNOON. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...ABE LONG TERM....JP AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
800 PM EDT SUN MAR 25 2012 .UPDATE... ISSUED AT 759 PM EDT SUN MAR 25 2012 THE LAST ISOLATED SHOWERS DISSIPATED OR MOVED OUT OF THE AREA AROUND 730 PM EDT...SO HAVE REMOVED ALL PRECIPITATION FROM THE NDFD AND ASSOCIATED PRODUCTS FOR THE OVERNIGHT PERIOD. ALSO MADE SOME MINOR UPDATES BASED ON LATEST OBSERVATIONAL TRENDS. THE MAIN FORECAST ISSUE IS HOW MUCH CLOUDINESS THERE WILL BE OVERNIGHT. THERE IS CONSIDERABLE LOW CLOUDINESS UPSTREAM OF THE AREA...AND LATEST NAM AND RUC GUIDANCE SHOW CONSIDERABLE LOW LEVEL MOISTURE...MAINLY BELOW 850 MB TO BE OVER THE AREA TONIGHT. WITH NORTHERLY FLOW EXPECT CLOUDINESS TO INCREASE IN COVERAGE DURING THE NIGHT...WITH MOSTLY CLOUDY SKIES BEING THE RESULT. UPDATE ISSUED AT 423 PM EDT SUN MAR 25 2012 BASED ON RADAR TRENDS ISOLATED TO SCATTERED SHOWERS WILL AFFECT FAR EASTERN KENTUCKY THROUGH 23Z. THIS IS CURRENTLY WELL DEPICTED IN NDFD. ONLY SOME MINOR NDFD UPDATES WERE MADE BASED ON LATEST SATELLITE AND SURFACE OBSERVATIONAL TRENDS. && .SHORT TERM...(LATE THIS AFTERNOON THROUGH TUESDAY) ISSUED AT 310 PM EDT SUN MAR 25 2012 UPPER LEVEL LOW WILL CONTINUE TO PULL AWAY FROM THE AREA TONIGHT GIVING WAY TO UPPER LEVEL RIDGING THROUGH THE REMAINDER OF THE PERIOD. THE UPPER LOW WILL REMAIN CLOSE ENOUGH TO KEEP A MENTION OF A FEW SHOWERS IN THE FORECAST FOR MOST AREAS LATE THIS AFTERNOON... WITH THE CHANCE OF SHOWERS LINGERING ACROSS THE TIP OF FAR EAST KENTUCKY THIS EVENING. IT APPEARS THAT INSTABILITY WILL NOT BE SUFFICIENT TO PRODUCE A TSTORM THIS FAR WEST SO REMOVED THAT MENTION FOR THIS AFTERNOON AND EVENING. A COLD FRONT WILL THEN DROP IN FROM THE NORTH LATE TONIGHT KEEPING A LIGHT BREEZE BLOWING FOR MOST LOCATIONS. MOISTURE POOLING ALONG THIS BOUNDARY IN CONJUNCTION WITH THE LIGHT NORTHEAST LOW LEVEL FLOW WILL LIKELY RESULT IN QUITE A BIT OF STRATUS DEVELOPING OVERNIGHT WITH MAYBE EVEN A LITTLE DRIZZLE. ANY CLOUD COVER SHOULD DISSOLVE BY MIDDAY MONDAY AS HIGH PRESSURE BEGINS TO BUILD DOWN INTO THE OHIO VALLEY ACCOMPANIED BY A MUCH DRIER AIRMASS. IN FACT...DEWPOINTS ARE PROGGED TO DROP INTO THE 20S OVER NORTHEAST KENTUCKY LATE MONDAY NIGHT AND THERE IS A CONCERN THAT TEMPERATURES WILL RESPOND TO THIS DRY AIR AND DROP LOW ENOUGH TO THREATEN A FROST OR FREEZE FOR SOME AREAS. CONFIDENCE IS NOT HIGH ENOUGH TO HOIST ANY HEADLINES AT THIS TIME THOUGH AS MODELS INDICATE THE POTENTIAL FOR SOME HIGH LEVEL CLOUDINESS TO MOVE IN OVERNIGHT AND POINT TO THERE BEING JUST ENOUGH WIND TO KEEP ANY FROST FORMATION ISOLATED AND CONFINED TO THE DEEPEST VALLEYS BASICALLY NORTH AND EAST OF JKL. HIGH PRESSURE WILL REMAIN IN CONTROL ON TUESDAY BUT HIGH LEVEL CLOUDS WILL BE ON THE INCREASE IN ADVANCE OF OUR NEXT WEATHER MAKER. TEMPS ARE TRICKY...VARYING 10 TO 15 DEGREES BETWEEN THE GFS AND NAM MOS AT ANY GIVEN POINT. TEND TO AGREE MORE WITH THE GFS NUMBERS WITH THE UPPER LEVEL RIDGE BUILDING IN AND WILL FORECAST HIGHS APPROACHING OR EXCEEDING 70 FOR MOST LOCATIONS. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 310 PM EDT SUN MAR 25 2012 MODELS CONTINUE TO DISPLAY GOOD CONTINUITY THRU MOST OF THE WORK WEEK BUT BEGIN TO DIVERGE RATHER SHARPLY ON FRIDAY WITH THE LONG WAVE PATTERN. HAVE GENERALLY FOLLOWED A BLEND OF THE MEDIUM RANGE OPERATIONAL/ENSEMBLE GUIDANCE THRU THE FIRST HALF OF THE PERIOD BEFORE GIVING MORE CREDENCE TO THE LESS EXTREME SOLUTION OF THE GFS OVER THE WEEKEND...THOUGH CONFIDENCE WITH THE DETAILS TOWARDS THE TAIL END OF THE PERIOD REMAINS RATHER LOW. VORTEX CURRENTLY MAKING LANDFALL ALONG THE CA/OR COAST IS EXPECTED TO SEND A DECENT SHORT WAVE OVER THE ROCKIES AND ACROSS THE NRN PLAINS BEFORE REACHING THE UPPER MIDWEST BY TUESDAY NIGHT TO START THE PERIOD. AS THIS WAVE CONTINUES TO PUSH EAST ALONG THE CANADIAN BORDER...THE COLD FRONT ASSOCIATED WITH THE SFC REFLECTION LOOKS TO SWEEP ACROSS THE OHIO RIVER AND INTO ERN KY ON WEDNESDAY...WITH ENOUGH INSTABILITY STILL ADVERTISED IN FCST SOUNDINGS AROUND THE AREA TO WARRANT CHANCES OF THUNDER FOR WEDNESDAY. GIVEN THE PROGRESSIVE NATURE OF THE PATTERN...WOULD PREFER TO GO MOSTLY QUIET BY WEDNESDAY NIGHT BUT WILL SETTLE FOR A GENTLE NUDGE IN THAT DIRECTION FOR THE MOMENT. CANADIAN HIGH PRESSURE BUILDS DOWN ACROSS THE GREAT LAKES AND INTO THE OHIO VALLEY ON THURSDAY...BRINGING ANOTHER BOUT OF BENIGN WEATHER THROUGH FRIDAY...AT WHICH POINT THE MODELS BEGIN PARTING WAYS WITH THEIR DEPICTION OF THE UPPER LEVEL FEATURES. REGARDLESS OF THEIR RESPECTIVE DIFFERENCES...ANY OF THE RECENT OFFINGS FROM THE GUIDANCE WOULD POINT TOWARDS AN UNSETTLED PATTERN PERSISTING THROUGH THE WEEKEND WITH PERIODS OF RAIN POSSIBLE AND A FEW THUNDERSTORMS NOT ENTIRELY OUT OF THE QUESTION. AT THIS TIME...WILL KEEP POPS IN THE LOW END CHANCE RANGE UNTIL A BETTER CONSENSUS CAN BE OBTAINED. TEMPERATURES OVER THE COURSE OF THE PERIOD LOOK TO CONTINUE FOLLOWING THE ABOVE NORMAL TREND...WITH TEMPS EARLY IN THE PERIOD STILL RUNNING WELL ABOVE NORMAL BEFORE TRENDING TOWARDS CLIMO BY THE BEGINNING OF NEXT WEEK. ONE NOTE OF CONCERN IS FOR THURSDAY NIGHT INTO FRIDAY MORNING WHERE AGAIN...MODELS POINT TOWARDS RELATIVELY CLEAR SKIES AND LIGHT WINDS WITH DEWPTS IN THE UPPER 20S AND LOWER 30S THROUGHOUT OUR NERN VALLEYS. HAVE STRAYED TOWARDS THE COOLER SIDE OF THE MOS LOWS FOR NOW AND...GIVEN THE EVOLVING UNCERTAINTY JUST BEYOND THIS WINDOW...WILL CONTINUE TO KEEP A CLOSE EYE ON THESE NUMBERS OVER THE NEXT FEW DAYS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 759 PM EDT SUN MAR 25 2012 MAIN ISSUE OF CONCERN FOR THIS FORECAST PERIOD IS THE MOVEMENT OF LOW CLOUD INTO THE AREA OR THE DEVELOPMENT OF LOW CLOUD ACROSS THE FORECAST AREA FOR TONIGHT. THERE IS CONSIDERABLE LOW LEVEL CLOUDINESS TO THE NORTH OF THE FORECAST AREA AT 2330Z. WITH THE NORTHERLY FLOW THIS WILL MOVE INTO THE AREA THIS EVENING. ALSO...WITH PLENTY OF MOISTURE BELOW 850 MB AND NORTHERLY WINDS ALSO LOOK FOR LOW CLOUD TO DEVELOP IN UPSLOPE FLOW. EXPECT MVFR CEILINGS TO MOVE INTO OR DEVELOP ACROSS THE FORECAST AREA THIS EVENING...AFFECTING THE TAF SITES AFTER 04Z. MVFR CEILINGS SHOULD THEN PREVAIL ACROSS MUCH OF THE AREA THROUGH 12Z...WITH CEILINGS LIFTING AND SKY COVER SCATTERING OUT ON MONDAY. VFR CONDITIONS WILL PREVAIL ACROSS THE AREA MONDAY AFTERNOON. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...ABE LONG TERM....JP AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
210 PM EDT SAT MAR 24 2012 .UPDATE... ISSUED AT 210 PM EDT SAT MAR 24 2012 SHOWERS AND THUNDERSTORMS HAVE BEGUN TO DEVELOP ACROSS PORTIONS OF THE AREA...PARTICULARLY SOUTHERN PORTIONS OF THE CWA IN RESPONSE TO DIURNAL HEATING AND APPROACH OF UPPER LEVEL LOW CURRENTLY OVER WESTERN KY. SHOWER ACTIVITY SHOULD BEGIN TO DIE DOWN AFTER SUNSET AND AS THE LOW PUSHES PAST OUR AREA TOWARDS THE ATLANTIC COAST. FIRST BAND OR ROUND OF SHOWERS CONTINUES TO MOVE NORTHEASTWARD. ADDITIONAL SHOWERS WILL FORM ALONG CONVERGENT ZONES ROTATING IN PINWHEEL FASHION AROUND THE PARENT LOW. INCREASED POPS SLIGHTLY FOR LOCATIONS THAT SHOWERS ARE CURRENTLY TAKING AIM FOR AND SHOULD AFFECT DURING THE NEXT FEW HOURS. SCATTERED THUNDER IS STILL A DECENT BET AS GOOD SFC HEATING CONTINUES TO DESTABILIZE THE BOUNDARY LAYER. BUMPED TEMPS UP SLIGHTLY IN THE EAST WHERE AMPLE SUNSHINE HAS ALREADY ALLOWED TEMPS TO SHOOT UP CLOSE TO FORECASTED HIGHS. UPDATE ISSUED AT 1054 AM EDT SAT MAR 24 2012 LULL IN SHOWER AND THUNDERSTORM ACTIVITY THIS MORNING WILL PICK BACK UP AGAIN THIS AFTERNOON WITH DIURNAL HEATING AND AS UPPER LEVEL LOW CURRENTLY OVER SOUTHERN IL AND WESTERN KY TRACKS ACROSS THE COMMONWEALTH THROUGH THE AFTERNOON TIME FRAME. REGIONAL SAT ALSO SHOWS SOME BREAKS IN THE CLOUD COVER. THIS WILL HELP STEEPEN UP THOSE BOUNDARY LAYER LAPSE RATES AS MID LEVELS COOL. SO A FEW STRONG STORMS CAN NOT BE RULED OUT THIS AFTERNOON. UPDATED POPS AND SKY COVER FOR LATEST TRENDS. TEMPS WERE NOT TOO BAD SO ONLY SOME MINOR TWEAKS THERE. EXPECT DIURNAL CU FIELD WILL FILL BACK IN BREAKS WITH TIME. WITH FCST SOUNDINGS SHOWING ONLY MARGINAL INSTABILITY THROUGH THE OVERNIGHT PERIODS...DID ADJUST WEATHER GRIDS TO INTRODUCE A MORE DIURNAL FLAVOR TO ANY THUNDERSTORM ACTIVITY. UPDATE ISSUED AT 745 AM EDT SAT MAR 24 2012 HOURLY POPS WERE UPDATED TO ACCOUNT FOR NEAR CATEGORICAL COVERAGE ONGOING AND OVER THE NEXT HOUR OR SO IN THE KY/WV AND VA TRI STATE AREA. OTHERWISE...HELD ONTO SOME SLIGHT CHANCE POPS AS FAR WEST AS A MIDDLESBORO TO JKL TO ELLIOTT COUNTY LINE OR SO OVER THE NEXT HOUR OR TWO...BEFORE BLENDING INTO POPS FROM THE PREVIOUS FORECAST THAT REFLECT AN INCREASE IN COVERAGE OF SHRA AND ISOLATED TO SCATTERED TSRA AS THE UPPER LEVEL LOW NEARS THE REGION AND THIS COMBINED WITH SOME SOLAR INSOLATION SHOULD LEAD TO AN INCREASE IN COVERAGE AND INTENSITY OF CONVECTION DURING THE AFTERNOON. HOURLY TEMP AND DEW POINT CURVES WERE ALSO FRESHENED UP BASED ON RECENT OBS. UPDATED GRIDS HAVE BEEN SENT ALONG WITH A FRESHENED UP ZFP. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 434 AM EDT SAT MAR 24 2012 SURFACE ANALYSIS ACROSS THE AREA AS OF 08Z HAS THE LINE OF SHOWERS AND THUNDERSTORMS WITH A SURFACE FRONT AND ASSOCIATED 500MB WAVE ROTATING AROUND A CLOSED CUT OFF LOW MOVING OFF TO THE EAST. LOOKING AT CURRENT RADAR TRENDS AND OBS...LOOKING LIKE ALL THE INSTABILITY HAS BEEN TAPPED OUT EAST AS ONLY A FEW CELLS SEEM TO BE LEFT. A FEW SHOWERS HAVE BEGUN TO DEVELOP BEHIND THE LINE OVER THE SOUTHWEST COUNTIES SO HAVE LEFT SOME ISOLATED SHOWERS MENTIONED IN THE ZONES DURING THE MORNING HOURS. THIS IS SUPPORTED BY THE HRRR AND RUC AS THE UPPER LEVEL SUPPORT WILL BE AVAILABLE ALL DAY TODAY AS THE LOW WILL SLOWLY MOVE SOUTH AND EAST. THINKING SHOWERS AND THUNDERSTORMS WILL REDEVELOP AGAIN TODAY WITH THE HEATING OF THE DAY AS ANOTHER 500MB WAVE ROTATES AROUND THE LOW AGAIN AND THROUGH EAST KENTUCKY AND AS SUCH...RAMPED UP POPS TO GOOD CHANCES AND ALSO WENT WITH COVERAGE RATHER THAN PROBABILITY. ALSO THE RAPID STABILIZATION DURING THE EVENING HOURS LEADS TO FOG DEVELOPING IN THE VALLEYS AND SO PUT FOG INTO THE ZONES TO ACCOUNT FOR THIS. BY SUNDAY NIGHT...THE SHORT TERM MODELS SEEM TO BE IN AGREEMENT THAT THE CLOSED LOW FINALLY DRIFTS OFF TO THE SOUTH AND EAST. SO WILL RAMP DOWN THE POPS FOR THIS TIME PERIOD. CONCERNING TEMPERATURES...THE MERIDIONAL PATTERN WITH A TROUGH MOVING THROUGH THE EASTERN US...WILL KEEP TEMPERATURES NEAR NORMAL FOR THE SHORT TERM PERIOD. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 434 AM EDT SAT MAR 24 2012 A RATHER PROGRESSIVE PATTERN IS EXPECTED DURING THE PERIOD. INITIALLY ON MONDAY...RECENT GFS AND ECMWF RUNS INDICATE THAT UPPER LEVEL RIDGING WILL BE BUILDING INTO THE REGION FROM THE PLAINS AND MS VALLEY WHILE THE SOUTHERN END OF A RIDGE OF SFC HIGH PRESSURE WILL BE NOSING INTO THE OH VALLEY AND APPALACHIAN REGION. THE UPPER LEVEL RIDGE IS EXPECTED TO CONTINUE TO BUILD INTO THE REGION ON MON NIGHT AND INTO TUE....WHILE THE AXIS OF THE SFC HIGH WILL SHIFT ON OFF TO THE EAST ON TUE. AS THE SFC HIGH SHIFTS EAST OF THE AREA...A WARM FRONT OR SFC TROUGH IS PROGGED TO SHIFT TO THE EASTERN PORTIONS OF THE CWA. AT THE SAME TIME...AN UPPER LEVEL TROUGH AND ASSOCIATED SYSTEM WILL TRACK FROM THE CENTRAL AND NORTHERN ROCKIES AND INTO THE NORTHERN PLAINS/WESTERN GREAT LAKES REGION BY TUE EVENING AND NIGHT WITH THIS UPPER LEVEL SYSTEM THEN TRACKING NEARLY DUE EAST INTO THE NORTHEASTERN STATES ON WED INTO WED NIGHT. UPPER LEVEL RIDGING IS THEN EXPECTED TO BUILD BACK INTO THE GREAT LAKES AND OH VALLEY AND APPALACHIAN REGION AND LIKELY REMAIN DOMINANT THROUGH THE END OF THE PERIOD. THE GREATEST UNCERTAINTY COMES AT THE END OF THE PERIOD AS THE GFS TRACKS A COUPLE OF SHORTWAVES EAST A BIT QUICKER AND IS WEAKER WITH THE LATE WEEK RIDGING. DURING THIS PERIOD OF GREATER UNCERTAINTY...GENERALLY FOLLOWED A BLEND OF THE MODEL CONSENSUS AND THE USUALLY RELIABLE ECMWF. A SFC LOW SHOULD FOLLOW A SIMILAR PATH AS THE UPPER LEVEL SYSTEM FROM MON TO TUE...REACHING THE GREAT LAKES REGION TUE NIGHT INTO WED AND THEN TRACKING OFF THE NORTHEASTERN US COAST WED NIGHT INTO THU. THIS SYSTEM WILL SEND A COLD FRONT INTO THE LOCAL AREA ON WED WITH THE MODEL CONSENSUS SHIFTING THIS FRONT SOUTH OF THE AREA ON WED NIGHT. ALTHOUGH I HAVE ALLOWED FOR SOME 10 POPS WHICH ARE PART OF THE MODEL CONSENSUS ON TUE AFTERNOON AS THE PAST COUPLE OF ECMWF RUNS DEVELOP SOME CONVECTION OVER THE NORTHEASTERN OR EASTERN PART OF THE CWA IN THE VICINITY OF THE SFC TROUGH/WARM FRONT FEATURE ON TUE...THE BEST CHANCE DURING THE PERIOD FOR MEASURABLE PRECIP WILL COME ON WED INTO WED EVENING. AS FOR TEMPERATURES...MAX TEMPERATURES SHOULD GENERALLY AVERAGE SLIGHTLY ABOVE NORMAL EARLY IN THE PERIOD AND AT THE END OF THE PERIOD TO AS MUCH AS 10 DEGREES OR MORE ABOVE NORMAL ON WED JUST AHEAD OF THE COLD FRONT. LOW THROUGH THE PERIOD SHOULD GENERALLY BE IN THE 40S OR EVEN THE 50S...WITH ONE EXCEPTION...MONDAY NIGHT. SFC HIGH PRESSURE SHOULD ALLOW FOR SOME OF THE NORMALLY COLDER VALLEY LOCATIONS IN THE FAR NORTH AND EAST TO REACH THE UPPER 30S ON MON NIGHT. THIS WOULD LEAD TO AT LEAST A SLIGHT CONCERN FOR SOME PATCHY FROST AT LEAST IF THESE MIN TEMPS WERE TO TREND SLIGHTLY COLDER AS RECENT WARM WEATHER HAS ALLOWED VEGETATION TO BE RUNNING A COUPLE OF WEEKS OR SO AHEAD OF AVERAGE. HOWEVER...ATTM...EVEN IT ONE WERE TO OCCUR IT APPEARS AS IF IT WOULD BE VERY PATCHY TO ISOLATED AND WOULD OCCUR IN THE COLDEST OF THE NORMALLY COLD SPOTS. THIS POTENTIAL SCENARIO WILL CONTINUE TO BE MONITORED...HOWEVER CONFIDENCE IN EVEN ISOLATED TO PATCHY VALLEY FROST IS TOO LOW AT THIS POINT TO INCLUDE IN THE HWO. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 210 PM EDT SAT MAR 24 2012 SHOWERS AND THUNDERSTORMS HAVE BEGUN TO DEVELOP ACROSS PORTIONS OF THE AREA...PARTICULARLY SOUTH PORTIONS OF THE CWA IN RESPONSE TO DIURNAL HEATING AND APPROACH OF UPPER LEVEL LOW CURRENTLY OVER WESTERN KY. THE MAIN THREAT OF RAIN WILL CONTINUE THROUGH THE FIRST SEVERAL HOURS OF THE TAF FORECAST...UNTIL AND JUST AFTER SUNSET. ACTIVITY SHOULD BEGIN TO DIE OUT THEREAFTER AS THE LOW PUSHES PAST OUR AREA TOWARDS THE ATLANTIC COAST. FIRST BAND OR ROUND OF SHOWERS WILL MOVE INTO VCTY OF JACKSON WITHIN AN HOUR. ONLY CONCERN WAS POTENTIAL FOR MIST...FOG TONIGHT. ATTM GUIDANCE SUGGEST THERE SHOULD BE ENOUGH CLOUD COVER AND WIND...MIXING TO MAINTAIN VFR OR HIGH END MVFR AS A WORSE CASE. WENT MORE OPTIMISTIC AND ONLY INCLUDED MVFR VSBYS AT KJKL FOR THE TYPICAL MIST THAT TENDS TO DEVELOP DURING THE PRE DAWN HORUS AND/OR THAT MOVES UP THE FROM THE VALLEY FLOOR AS DAWN BREAKS. WINDS HAVE INCREASED AND VEERED OUT OF THE WEST AT 5 TO 10 KTS BUT WILL DIE OFF AGAIN AS THE MAIN LOW CLOSES IN. WINDS WILL INCREASE AGAIN ON SUNDAY OUT OF THE NW AROUND 10KTS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...RAY SHORT TERM...SHALLENBERGER LONG TERM....JP AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
1054 AM EDT SAT MAR 24 2012 .UPDATE... ISSUED AT 1054 AM EDT SAT MAR 24 2012 LULL IN SHOWER AND THUNDERSTORM ACTIVITY THIS MORNING WILL PICK BACK UP AGAIN THIS AFTERNOON WITH DIURNAL HEATING AND AS UPPER LEVEL LOW CURRENTLY OVER SOUTHERN IL AND WESTERN KY TRACKS ACROSS THE COMMONWEALTH THROUGH THE AFTERNOON TIME FRAME. REGIONAL SAT ALSO SHOWS SOME BREAKS IN THE CLOUD COVER. THIS WILL HELP STEEPEN UP THOSE BOUNDARY LAYER LAPSE RATES AS MID LEVELS COOL. SO A FEW STRONG STORMS CAN NOT BE RULED OUT THIS AFTERNOON. UPDATED POPS AND SKY COVER FOR LATEST TRENDS. TEMPS WERE NOT TOO BAD SO ONLY SOME MINOR TWEAKS THERE. EXPECT DIURNAL CU FIELD WILL FILL BACK IN BREAKS WITH TIME. WITH FCST SOUNDINGS SHOWING ONLY MARGINAL INSTABILITY THROUGH THE OVERNIGHT PERIODS...DID ADJUST WEATHER GRIDS TO INTRODUCE A MORE DIURNAL FLAVOR TO ANY THUNDERSTORM ACTIVITY. UPDATE ISSUED AT 745 AM EDT SAT MAR 24 2012 HOURLY POPS WERE UPDATED TO ACCOUNT FOR NEAR CATEGORICAL COVERAGE ONGOING AND OVER THE NEXT HOUR OR SO IN THE KY/WV AND VA TRI STATE AREA. OTHERWISE...HELD ONTO SOME SLIGHT CHANCE POPS AS FAR WEST AS A MIDDLESBORO TO JKL TO ELLIOTT COUNTY LINE OR SO OVER THE NEXT HOUR OR TWO...BEFORE BLENDING INTO POPS FROM THE PREVIOUS FORECAST THAT REFLECT AN INCREASE IN COVERAGE OF SHRA AND ISOLATED TO SCATTERED TSRA AS THE UPPER LEVEL LOW NEARS THE REGION AND THIS COMBINED WITH SOME SOLAR INSOLATION SHOULD LEAD TO AN INCREASE IN COVERAGE AND INTENSITY OF CONVECTION DURING THE AFTERNOON. HOURLY TEMP AND DEW POINT CURVES WERE ALSO FRESHENED UP BASED ON RECENT OBS. UPDATED GRIDS HAVE BEEN SENT ALONG WITH A FRESHENED UP ZFP. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 434 AM EDT SAT MAR 24 2012 SURFACE ANALYSIS ACROSS THE AREA AS OF 08Z HAS THE LINE OF SHOWERS AND THUNDERSTORMS WITH A SURFACE FRONT AND ASSOCIATED 500MB WAVE ROTATING AROUND A CLOSED CUT OFF LOW MOVING OFF TO THE EAST. LOOKING AT CURRENT RADAR TRENDS AND OBS...LOOKING LIKE ALL THE INSTABILITY HAS BEEN TAPPED OUT EAST AS ONLY A FEW CELLS SEEM TO BE LEFT. A FEW SHOWERS HAVE BEGUN TO DEVELOP BEHIND THE LINE OVER THE SOUTHWEST COUNTIES SO HAVE LEFT SOME ISOLATED SHOWERS MENTIONED IN THE ZONES DURING THE MORNING HOURS. THIS IS SUPPORTED BY THE HRRR AND RUC AS THE UPPER LEVEL SUPPORT WILL BE AVAILABLE ALL DAY TODAY AS THE LOW WILL SLOWLY MOVE SOUTH AND EAST. THINKING SHOWERS AND THUNDERSTORMS WILL REDEVELOP AGAIN TODAY WITH THE HEATING OF THE DAY AS ANOTHER 500MB WAVE ROTATES AROUND THE LOW AGAIN AND THROUGH EAST KENTUCKY AND AS SUCH...RAMPED UP POPS TO GOOD CHANCES AND ALSO WENT WITH COVERAGE RATHER THAN PROBABILITY. ALSO THE RAPID STABILIZATION DURING THE EVENING HOURS LEADS TO FOG DEVELOPING IN THE VALLEYS AND SO PUT FOG INTO THE ZONES TO ACCOUNT FOR THIS. BY SUNDAY NIGHT...THE SHORT TERM MODELS SEEM TO BE IN AGREEMENT THAT THE CLOSED LOW FINALLY DRIFTS OFF TO THE SOUTH AND EAST. SO WILL RAMP DOWN THE POPS FOR THIS TIME PERIOD. CONCERNING TEMPERATURES...THE MERIDIONAL PATTERN WITH A TROUGH MOVING THROUGH THE EASTERN US...WILL KEEP TEMPERATURES NEAR NORMAL FOR THE SHORT TERM PERIOD. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 434 AM EDT SAT MAR 24 2012 A RATHER PROGRESSIVE PATTERN IS EXPECTED DURING THE PERIOD. INITIALLY ON MONDAY...RECENT GFS AND ECMWF RUNS INDICATE THAT UPPER LEVEL RIDGING WILL BE BUILDING INTO THE REGION FROM THE PLAINS AND MS VALLEY WHILE THE SOUTHERN END OF A RIDGE OF SFC HIGH PRESSURE WILL BE NOSING INTO THE OH VALLEY AND APPALACHIAN REGION. THE UPPER LEVEL RIDGE IS EXPECTED TO CONTINUE TO BUILD INTO THE REGION ON MON NIGHT AND INTO TUE....WHILE THE AXIS OF THE SFC HIGH WILL SHIFT ON OFF TO THE EAST ON TUE. AS THE SFC HIGH SHIFTS EAST OF THE AREA...A WARM FRONT OR SFC TROUGH IS PROGGED TO SHIFT TO THE EASTERN PORTIONS OF THE CWA. AT THE SAME TIME...AN UPPER LEVEL TROUGH AND ASSOCIATED SYSTEM WILL TRACK FROM THE CENTRAL AND NORTHERN ROCKIES AND INTO THE NORTHERN PLAINS/WESTERN GREAT LAKES REGION BY TUE EVENING AND NIGHT WITH THIS UPPER LEVEL SYSTEM THEN TRACKING NEARLY DUE EAST INTO THE NORTHEASTERN STATES ON WED INTO WED NIGHT. UPPER LEVEL RIDGING IS THEN EXPECTED TO BUILD BACK INTO THE GREAT LAKES AND OH VALLEY AND APPALACHIAN REGION AND LIKELY REMAIN DOMINANT THROUGH THE END OF THE PERIOD. THE GREATEST UNCERTAINTY COMES AT THE END OF THE PERIOD AS THE GFS TRACKS A COUPLE OF SHORTWAVES EAST A BIT QUICKER AND IS WEAKER WITH THE LATE WEEK RIDGING. DURING THIS PERIOD OF GREATER UNCERTAINTY...GENERALLY FOLLOWED A BLEND OF THE MODEL CONSENSUS AND THE USUALLY RELIABLE ECMWF. A SFC LOW SHOULD FOLLOW A SIMILAR PATH AS THE UPPER LEVEL SYSTEM FROM MON TO TUE...REACHING THE GREAT LAKES REGION TUE NIGHT INTO WED AND THEN TRACKING OFF THE NORTHEASTERN US COAST WED NIGHT INTO THU. THIS SYSTEM WILL SEND A COLD FRONT INTO THE LOCAL AREA ON WED WITH THE MODEL CONSENSUS SHIFTING THIS FRONT SOUTH OF THE AREA ON WED NIGHT. ALTHOUGH I HAVE ALLOWED FOR SOME 10 POPS WHICH ARE PART OF THE MODEL CONSENSUS ON TUE AFTERNOON AS THE PAST COUPLE OF ECMWF RUNS DEVELOP SOME CONVECTION OVER THE NORTHEASTERN OR EASTERN PART OF THE CWA IN THE VICINITY OF THE SFC TROUGH/WARM FRONT FEATURE ON TUE...THE BEST CHANCE DURING THE PERIOD FOR MEASURABLE PRECIP WILL COME ON WED INTO WED EVENING. AS FOR TEMPERATURES...MAX TEMPERATURES SHOULD GENERALLY AVERAGE SLIGHTLY ABOVE NORMAL EARLY IN THE PERIOD AND AT THE END OF THE PERIOD TO AS MUCH AS 10 DEGREES OR MORE ABOVE NORMAL ON WED JUST AHEAD OF THE COLD FRONT. LOW THROUGH THE PERIOD SHOULD GENERALLY BE IN THE 40S OR EVEN THE 50S...WITH ONE EXCEPTION...MONDAY NIGHT. SFC HIGH PRESSURE SHOULD ALLOW FOR SOME OF THE NORMALLY COLDER VALLEY LOCATIONS IN THE FAR NORTH AND EAST TO REACH THE UPPER 30S ON MON NIGHT. THIS WOULD LEAD TO AT LEAST A SLIGHT CONCERN FOR SOME PATCHY FROST AT LEAST IF THESE MIN TEMPS WERE TO TREND SLIGHTLY COLDER AS RECENT WARM WEATHER HAS ALLOWED VEGETATION TO BE RUNNING A COUPLE OF WEEKS OR SO AHEAD OF AVERAGE. HOWEVER...ATTM...EVEN IT ONE WERE TO OCCUR IT APPEARS AS IF IT WOULD BE VERY PATCHY TO ISOLATED AND WOULD OCCUR IN THE COLDEST OF THE NORMALLY COLD SPOTS. THIS POTENTIAL SCENARIO WILL CONTINUE TO BE MONITORED...HOWEVER CONFIDENCE IN EVEN ISOLATED TO PATCHY VALLEY FROST IS TOO LOW AT THIS POINT TO INCLUDE IN THE HWO. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 656 AM EDT SAT MAR 24 2012 CURRENT CONDITIONS ACROSS EASTERN KENTUCKY AS OF 11Z HAS SOME SHOWERS MOVING OFF TO THE EAST. SOME OF THE PRECIP OVERNIGHT HAS MOISTEN THE BL AND SOME FOG HAS DEVELOPED IN THE VALLEYS. MOST OF THE AREA THOUGH IS DEALING WITH SOME LOW LEVEL STRATUS AND THIS IS SEEN ON THE RIDGES AS JKL HAS SOME FOG ON THE RIDGES. THE FOG/STRATUS SHOULD BURN OFF BY 15Z TODAY. WITH ANOTHER WAVE MOVING THROUGH TODAY WITH THE UPPER LEVEL LOW AND THE HEATING OF THE DAY...EXPECT TO SEE SOME SHOWERS AND THUNDERSTORMS DEVELOPING AGAIN TODAY. THE RAINFALL AGAIN WILL SET THE STAGE FOR MORE FOG AND LOW LEVEL STRATUS AGAIN TONIGHT AND HAVE PUT IFR CONDITIONS AT THE TAF SITES BY 08Z TONIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...RAY SHORT TERM...SHALLENBERGER LONG TERM....JP AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
746 AM EDT SAT MAR 24 2012 .UPDATE... ISSUED AT 745 AM EDT SAT MAR 24 2012 HOURLY POPS WERE UPDATED TO ACCOUNT FOR NEAR CATEGORICAL COVERAGE ONGOING AND OVER THE NEXT HOUR OR SO IN THE KY/WV AND VA TRI STATE AREA. OTHERWISE...HELD ONTO SOME SLIGHT CHANCE POPS AS FAR WEST AS A MIDDLESBORO TO JKL TO ELLIOTT COUNTY LINE OR SO OVER THE NEXT HOUR OR TWO...BEFORE BLENDING INTO POPS FROM THE PREVIOUS FORECAST THAT REFLECT AN INCREASE IN COVERAGE OF SHRA AND ISOLATED TO SCATTERED TSRA AS THE UPPER LEVEL LOW NEARS THE REGION AND THIS COMBINED WITH SOME SOLAR INSOLATION SHOULD LEAD TO AN INCREASE IN COVERAGE AND INTENSITY OF CONVECTION DURING THE AFTERNOON. HOURLY TEMP AND DEWPOINT CURVES WERE ALSO FRESHENED UP BASED ON RECENT OBS. UPDATED GRIDS HAVE BEEN SENT ALONG WITH A FRESHENED UP ZFP. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 434 AM EDT SAT MAR 24 2012 SURFACE ANALYSIS ACROSS THE AREA AS OF 08Z HAS THE LINE OF SHOWERS AND THUNDERSTORMS WITH A SURFACE FRONT AND ASSOCIATED 500MB WAVE ROTATING AROUND A CLOSED CUT OFF LOW MOVING OFF TO THE EAST. LOOKING AT CURRENT RADAR TRENDS AND OBS...LOOKING LIKE ALL THE INSTABILITY HAS BEEN TAPPED OUT EAST AS ONLY A FEW CELLS SEEM TO BE LEFT. A FEW SHOWERS HAVE BEGUN TO DEVELOP BEHIND THE LINE OVER THE SOUTHWEST COUNTIES SO HAVE LEFT SOME ISOLATED SHOWERS MENTIONED IN THE ZONES DURING THE MORNING HOURS. THIS IS SUPPORTED BY THE HRRR AND RUC AS THE UPPER LEVEL SUPPORT WILL BE AVAILABLE ALL DAY TODAY AS THE LOW WILL SLOWLY MOVE SOUTH AND EAST. THINKING SHOWERS AND THUNDERSTORMS WILL REDEVELOP AGAIN TODAY WITH THE HEATING OF THE DAY AS ANOTHER 500MB WAVE ROTATES AROUND THE LOW AGAIN AND THROUGH EAST KENTUCKY AND AS SUCH...RAMPED UP POPS TO GOOD CHANCES AND ALSO WENT WITH COVERAGE RATHER THAN PROBABILITY. ALSO THE RAPID STABILIZATION DURING THE EVENING HOURS LEADS TO FOG DEVELOPING IN THE VALLEYS AND SO PUT FOG INTO THE ZONES TO ACCOUNT FOR THIS. BY SUNDAY NIGHT...THE SHORT TERM MODELS SEEM TO BE IN AGREEMENT THAT THE CLOSED LOW FINALLY DRIFTS OFF TO THE SOUTH AND EAST. SO WILL RAMP DOWN THE POPS FOR THIS TIME PERIOD. CONCERNING TEMPERATURES...THE MERIDIONAL PATTERN WITH A TROUGH MOVING THROUGH THE EASTERN US...WILL KEEP TEMPERATURES NEAR NORMAL FOR THE SHORT TERM PERIOD. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 434 AM EDT SAT MAR 24 2012 A RATHER PROGRESSIVE PATTERN IS EXPECTED DURING THE PERIOD. INITIALLY ON MONDAY...RECENT GFS AND ECMWF RUNS INDICATE THAT UPPER LEVEL RIDGING WILL BE BUILDING INTO THE REGION FROM THE PLAINS AND MS VALLEY WHILE THE SOUTHERN END OF A RIDGE OF SFC HIGH PRESSURE WILL BE NOSING INTO THE OH VALLEY AND APPALACHIAN REGION. THE UPPER LEVEL RIDGE IS EXPECTED TO CONTINUE TO BUILD INTO THE REGION ON MON NIGHT AND INTO TUE....WHILE THE AXIS OF THE SFC HIGH WILL SHIFT ON OFF TO THE EAST ON TUE. AS THE SFC HIGH SHIFTS EAST OF THE AREA...A WARM FRONT OR SFC TROUGH IS PROGGED TO SHIFT TO THE EASTERN PORTIONS OF THE CWA. AT THE SAME TIME...AN UPPER LEVEL TROUGH AND ASSOCIATED SYSTEM WILL TRACK FROM THE CENTRAL AND NORTHERN ROCKIES AND INTO THE NORTHERN PLAINS/WESTERN GREAT LAKES REGION BY TUE EVENING AND NIGHT WITH THIS UPPER LEVEL SYSTEM THEN TRACKING NEARLY DUE EAST INTO THE NORTHEASTERN STATES ON WED INTO WED NIGHT. UPPER LEVEL RIDGING IS THEN EXPECTED TO BUILD BACK INTO THE GREAT LAKES AND OH VALLEY AND APPALACHIAN REGION AND LIKELY REMAIN DOMINANT THROUGH THE END OF THE PERIOD. THE GREATEST UNCERTAINTY COMES AT THE END OF THE PERIOD AS THE GFS TRACKS A COUPLE OF SHORTWAVES EAST A BIT QUICKER AND IS WEAKER WITH THE LATE WEEK RIDGING. DURING THIS PERIOD OF GREATER UNCERTAINTY...GENERALLY FOLLOWED A BLEND OF THE MODEL CONSENSUS AND THE USUALLY RELIABLE ECMWF. A SFC LOW SHOULD FOLLOW A SIMILAR PATH AS THE UPPER LEVEL SYSTEM FROM MON TO TUE...REACHING THE GREAT LAKES REGION TUE NIGHT INTO WED AND THEN TRACKING OFF THE NORTHEASTERN US COAST WED NIGHT INTO THU. THIS SYSTEM WILL SEND A COLD FRONT INTO THE LOCAL AREA ON WED WITH THE MODEL CONSENSUS SHIFTING THIS FRONT SOUTH OF THE AREA ON WED NIGHT. ALTHOUGH I HAVE ALLOWED FOR SOME 10 POPS WHICH ARE PART OF THE MODEL CONSENSUS ON TUE AFTERNOON AS THE PAST COUPLE OF ECMWF RUNS DEVELOP SOME CONVECTION OVER THE NORTHEASTERN OR EASTERN PART OF THE CWA IN THE VICINITY OF THE SFC TROUGH/WARM FRONT FEATURE ON TUE...THE BEST CHANCE DURING THE PERIOD FOR MEASURABLE PRECIP WILL COME ON WED INTO WED EVENING. AS FOR TEMPERATURES...MAX TEMPERATURES SHOULD GENERALLY AVERAGE SLIGHTLY ABOVE NORMAL EARLY IN THE PERIOD AND AT THE END OF THE PERIOD TO AS MUCH AS 10 DEGREES OR MORE ABOVE NORMAL ON WED JUST AHEAD OF THE COLD FRONT. LOW THROUGH THE PERIOD SHOULD GENERALLY BE IN THE 40S OR EVEN THE 50S...WITH ONE EXCEPTION...MONDAY NIGHT. SFC HIGH PRESSURE SHOULD ALLOW FOR SOME OF THE NORMALLY COLDER VALLEY LOCATIONS IN THE FAR NORTH AND EAST TO REACH THE UPPER 30S ON MON NIGHT. THIS WOULD LEAD TO AT LEAST A SLIGHT CONCERN FOR SOME PATCHY FROST AT LEAST IF THESE MIN TEMPS WERE TO TREND SLIGHTLY COLDER AS RECENT WARM WEATHER HAS ALLOWED VEGETATION TO BE RUNNING A COUPLE OF WEEKS OR SO AHEAD OF AVERAGE. HOWEVER...ATTM...EVEN IT ONE WERE TO OCCUR IT APPEARS AS IF IT WOULD BE VERY PATCHY TO ISOLATED AND WOULD OCCUR IN THE COLDEST OF THE NORMALLY COLD SPOTS. THIS POTENTIAL SCENARIO WILL CONTINUE TO BE MONITORED...HOWEVER CONFIDENCE IN EVEN ISOLATED TO PATCHY VALLEY FROST IS TOO LOW AT THIS POINT TO INCLUDE IN THE HWO. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 656 AM EDT SAT MAR 24 2012 CURRENT CONDITIONS ACROSS EASTERN KENTUCKY AS OF 11Z HAS SOME SHOWERS MOVING OFF TO THE EAST. SOME OF THE PRECIP OVERNIGHT HAS MOISTEN THE BL AND SOME FOG HAS DEVELOPED IN THE VALLEYS. MOST OF THE AREA THOUGH IS DEALING WITH SOME LOW LEVEL STRATUS AND THIS IS SEEN ON THE RIDGES AS JKL HAS SOME FOG ON THE RIDGES. THE FOG/STRATUS SHOULD BURN OFF BY 15Z TODAY. WITH ANOTHER WAVE MOVING THROUGH TODAY WITH THE UPPER LEVEL LOW AND THE HEATING OF THE DAY...EXPECT TO SEE SOME SHOWERS AND THUNDERSTORMS DEVELOPING AGAIN TODAY. THE RAINFALL AGAIN WILL SET THE STAGE FOR MORE FOG AND LOW LEVEL STRATUS AGAIN TONIGHT AND HAVE PUT IFR CONDITIONS AT THE TAF SITES BY 08Z TONIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...SHALLENBERGER LONG TERM....JP AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
655 AM EDT SAT MAR 24 2012 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 434 AM EDT SAT MAR 24 2012 SURFACE ANALYSIS ACROSS THE AREA AS OF 08Z HAS THE LINE OF SHOWERS AND THUNDERSTORMS WITH A SURFACE FRONT AND ASSOCIATED 500MB WAVE ROTATING AROUND A CLOSED CUT OFF LOW MOVING OFF TO THE EAST. LOOKING AT CURRENT RADAR TRENDS AND OBS...LOOKING LIKE ALL THE INSTABILITY HAS BEEN TAPPED OUT EAST AS ONLY A FEW CELLS SEEM TO BE LEFT. A FEW SHOWERS HAVE BEGUN TO DEVELOP BEHIND THE LINE OVER THE SOUTHWEST COUNTIES SO HAVE LEFT SOME ISOLATED SHOWERS MENTIONED IN THE ZONES DURING THE MORNING HOURS. THIS IS SUPPORTED BY THE HRRR AND RUC AS THE UPPER LEVEL SUPPORT WILL BE AVAILABLE ALL DAY TODAY AS THE LOW WILL SLOWLY MOVE SOUTH AND EAST. THINKING SHOWERS AND THUNDERSTORMS WILL REDEVELOP AGAIN TODAY WITH THE HEATING OF THE DAY AS ANOTHER 500MB WAVE ROTATES AROUND THE LOW AGAIN AND THROUGH EAST KENTUCKY AND AS SUCH...RAMPED UP POPS TO GOOD CHANCES AND ALSO WENT WITH COVERAGE RATHER THAN PROBABILITY. ALSO THE RAPID STABILIZATION DURING THE EVENING HOURS LEADS TO FOG DEVELOPING IN THE VALLEYS AND SO PUT FOG INTO THE ZONES TO ACCOUNT FOR THIS. BY SUNDAY NIGHT...THE SHORT TERM MODELS SEEM TO BE IN AGREEMENT THAT THE CLOSED LOW FINALLY DRIFTS OFF TO THE SOUTH AND EAST. SO WILL RAMP DOWN THE POPS FOR THIS TIME PERIOD. CONCERNING TEMPERATURES...THE MERIDIONAL PATTERN WITH A TROUGH MOVING THROUGH THE EASTERN US...WILL KEEP TEMPERATURES NEAR NORMAL FOR THE SHORT TERM PERIOD. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 434 AM EDT SAT MAR 24 2012 A RATHER PROGRESSIVE PATTERN IS EXPECTED DURING THE PERIOD. INITIALLY ON MONDAY...RECENT GFS AND ECMWF RUNS INDICATE THAT UPPER LEVEL RIDGING WILL BE BUILDING INTO THE REGION FROM THE PLAINS AND MS VALLEY WHILE THE SOUTHERN END OF A RIDGE OF SFC HIGH PRESSURE WILL BE NOSING INTO THE OH VALLEY AND APPALACHIAN REGION. THE UPPER LEVEL RIDGE IS EXPECTED TO CONTINUE TO BUILD INTO THE REGION ON MON NIGHT AND INTO TUE....WHILE THE AXIS OF THE SFC HIGH WILL SHIFT ON OFF TO THE EAST ON TUE. AS THE SFC HIGH SHIFTS EAST OF THE AREA...A WARM FRONT OR SFC TROUGH IS PROGGED TO SHIFT TO THE EASTERN PORTIONS OF THE CWA. AT THE SAME TIME...AN UPPER LEVEL TROUGH AND ASSOCIATED SYSTEM WILL TRACK FROM THE CENTRAL AND NORTHERN ROCKIES AND INTO THE NORTHERN PLAINS/WESTERN GREAT LAKES REGION BY TUE EVENING AND NIGHT WITH THIS UPPER LEVEL SYSTEM THEN TRACKING NEARLY DUE EAST INTO THE NORTHEASTERN STATES ON WED INTO WED NIGHT. UPPER LEVEL RIDGING IS THEN EXPECTED TO BUILD BACK INTO THE GREAT LAKES AND OH VALLEY AND APPALACHIAN REGION AND LIKELY REMAIN DOMINANT THROUGH THE END OF THE PERIOD. THE GREATEST UNCERTAINTY COMES AT THE END OF THE PERIOD AS THE GFS TRACKS A COUPLE OF SHORTWAVES EAST A BIT QUICKER AND IS WEAKER WITH THE LATE WEEK RIDGING. DURING THIS PERIOD OF GREATER UNCERTAINTY...GENERALLY FOLLOWED A BLEND OF THE MODEL CONSENSUS AND THE USUALLY RELIABLE ECMWF. A SFC LOW SHOULD FOLLOW A SIMILAR PATH AS THE UPPER LEVEL SYSTEM FROM MON TO TUE...REACHING THE GREAT LAKES REGION TUE NIGHT INTO WED AND THEN TRACKING OFF THE NORTHEASTERN US COAST WED NIGHT INTO THU. THIS SYSTEM WILL SEND A COLD FRONT INTO THE LOCAL AREA ON WED WITH THE MODEL CONSENSUS SHIFTING THIS FRONT SOUTH OF THE AREA ON WED NIGHT. ALTHOUGH I HAVE ALLOWED FOR SOME 10 POPS WHICH ARE PART OF THE MODEL CONSENSUS ON TUE AFTERNOON AS THE PAST COUPLE OF ECMWF RUNS DEVELOP SOME CONVECTION OVER THE NORTHEASTERN OR EASTERN PART OF THE CWA IN THE VICINITY OF THE SFC TROUGH/WARM FRONT FEATURE ON TUE...THE BEST CHANCE DURING THE PERIOD FOR MEASURABLE PRECIP WILL COME ON WED INTO WED EVENING. AS FOR TEMPERATURES...MAX TEMPERATURES SHOULD GENERALLY AVERAGE SLIGHTLY ABOVE NORMAL EARLY IN THE PERIOD AND AT THE END OF THE PERIOD TO AS MUCH AS 10 DEGREES OR MORE ABOVE NORMAL ON WED JUST AHEAD OF THE COLD FRONT. LOW THROUGH THE PERIOD SHOULD GENERALLY BE IN THE 40S OR EVEN THE 50S...WITH ONE EXCEPTION...MONDAY NIGHT. SFC HIGH PRESSURE SHOULD ALLOW FOR SOME OF THE NORMALLY COLDER VALLEY LOCATIONS IN THE FAR NORTH AND EAST TO REACH THE UPPER 30S ON MON NIGHT. THIS WOULD LEAD TO AT LEAST A SLIGHT CONCERN FOR SOME PATCHY FROST AT LEAST IF THESE MIN TEMPS WERE TO TREND SLIGHTLY COLDER AS RECENT WARM WEATHER HAS ALLOWED VEGETATION TO BE RUNNING A COUPLE OF WEEKS OR SO AHEAD OF AVERAGE. HOWEVER...ATTM...EVEN IT ONE WERE TO OCCUR IT APPEARS AS IF IT WOULD BE VERY PATCHY TO ISOLATED AND WOULD OCCUR IN THE COLDEST OF THE NORMALLY COLD SPOTS. THIS POTENTIAL SCENARIO WILL CONTINUE TO BE MONITORED...HOWEVER CONFIDENCE IN EVEN ISOLATED TO PATCHY VALLEY FROST IS TOO LOW AT THIS POINT TO INCLUDE IN THE HWO. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 656 AM EDT SAT MAR 24 2012 CURRENT CONDITIONS ACROSS EASTERN KENTUCKY AS OF 11Z HAS SOME SHOWERS MOVING OFF TO THE EAST. SOME OF THE PRECIP OVERNIGHT HAS MOISTEN THE BL AND SOME FOG HAS DEVELOPED IN THE VALLEYS. MOST OF THE AREA THOUGH IS DEALING WITH SOME LOW LEVEL STRATUS AND THIS IS SEEN ON THE RIDGES AS JKL HAS SOME FOG ON THE RIDGES. THE FOG/STRATUS SHOULD BURN OFF BY 15Z TODAY. WITH ANOTHER WAVE MOVING THROUGH TODAY WITH THE UPPER LEVEL LOW AND THE HEATING OF THE DAY...EXPECT TO SEE SOME SHOWERS AND THUNDERSTORMS DEVELOPING AGAIN TODAY. THE RAINFALL AGAIN WILL SET THE STAGE FOR MORE FOG AND LOW LEVEL STRATUS AGAIN TONIGHT AND HAVE PUT IFR CONDITIONS AT THE TAF SITES BY 08Z TONIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SHALLENBERGER LONG TERM....JP AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
434 AM EDT SAT MAR 24 2012 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 434 AM EDT SAT MAR 24 2012 SURFACE ANALYSIS ACROSS THE AREA AS OF 08Z HAS THE LINE OF SHOWERS AND THUNDERSTORMS WITH A SURFACE FRONT AND ASSOCIATED 500MB WAVE ROTATING AROUND A CLOSED CUT OFF LOW MOVING OFF TO THE EAST. LOOKING AT CURRENT RADAR TRENDS AND OBS...LOOKING LIKE ALL THE INSTABILITY HAS BEEN TAPPED OUT EAST AS ONLY A FEW CELLS SEEM TO BE LEFT. A FEW SHOWERS HAVE BEGUN TO DEVELOP BEHIND THE LINE OVER THE SOUTHWEST COUNTIES SO HAVE LEFT SOME ISOLATED SHOWERS MENTIONED IN THE ZONES DURING THE MORNING HOURS. THIS IS SUPPORTED BY THE HRRR AND RUC AS THE UPPER LEVEL SUPPORT WILL BE AVAILABLE ALL DAY TODAY AS THE LOW WILL SLOWLY MOVE SOUTH AND EAST. THINKING SHOWERS AND THUNDERSTORMS WILL REDEVELOP AGAIN TODAY WITH THE HEATING OF THE DAY AS ANOTHER 500MB WAVE ROTATES AROUND THE LOW AGAIN AND THROUGH EAST KENTUCKY AND AS SUCH...RAMPED UP POPS TO GOOD CHANCES AND ALSO WENT WITH COVERAGE RATHER THAN PROBABILITY. ALSO THE RAPID STABILIZATION DURING THE EVENING HOURS LEADS TO FOG DEVELOPING IN THE VALLEYS AND SO PUT FOG INTO THE ZONES TO ACCOUNT FOR THIS. BY SUNDAY NIGHT...THE SHORT TERM MODELS SEEM TO BE IN AGREEMENT THAT THE CLOSED LOW FINALLY DRIFTS OFF TO THE SOUTH AND EAST. SO WILL RAMP DOWN THE POPS FOR THIS TIME PERIOD. CONCERNING TEMPERATURES...THE MERIDIONAL PATTERN WITH A TROUGH MOVING THROUGH THE EASTERN US...WILL KEEP TEMPERATURES NEAR NORMAL FOR THE SHORT TERM PERIOD. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 434 AM EDT SAT MAR 24 2012 A RATHER PROGRESSIVE PATTERN IS EXPECTED DURING THE PERIOD. INITIALLY ON MONDAY...RECENT GFS AND ECMWF RUNS INDICATE THAT UPPER LEVEL RIDGING WILL BE BUILDING INTO THE REGION FROM THE PLAINS AND MS VALLEY WHILE THE SOUTHERN END OF A RIDGE OF SFC HIGH PRESSURE WILL BE NOSING INTO THE OH VALLEY AND APPALACHIAN REGION. THE UPPER LEVEL RIDGE IS EXPECTED TO CONTINUE TO BUILD INTO THE REGION ON MON NIGHT AND INTO TUE....WHILE THE AXIS OF THE SFC HIGH WILL SHIFT ON OFF TO THE EAST ON TUE. AS THE SFC HIGH SHIFTS EAST OF THE AREA...A WARM FRONT OR SFC TROUGH IS PROGGED TO SHIFT TO THE EASTERN PORTIONS OF THE CWA. AT THE SAME TIME...AN UPPER LEVEL TROUGH AND ASSOCIATED SYSTEM WILL TRACK FROM THE CENTRAL AND NORTHERN ROCKIES AND INTO THE NORTHERN PLAINS/WESTERN GREAT LAKES REGION BY TUE EVENING AND NIGHT WITH THIS UPPER LEVEL SYSTEM THEN TRACKING NEARLY DUE EAST INTO THE NORTHEASTERN STATES ON WED INTO WED NIGHT. UPPER LEVEL RIDGING IS THEN EXPECTED TO BUILD BACK INTO THE GREAT LAKES AND OH VALLEY AND APPALACHIAN REGION AND LIKELY REMAIN DOMINANT THROUGH THE END OF THE PERIOD. THE GREATEST UNCERTAINTY COMES AT THE END OF THE PERIOD AS THE GFS TRACKS A COUPLE OF SHORTWAVES EAST A BIT QUICKER AND IS WEAKER WITH THE LATE WEEK RIDGING. DURING THIS PERIOD OF GREATER UNCERTAINTY...GENERALLY FOLLOWED A BLEND OF THE MODEL CONSENSUS AND THE USUALLY RELIABLE ECMWF. A SFC LOW SHOULD FOLLOW A SIMILAR PATH AS THE UPPER LEVEL SYSTEM FROM MON TO TUE...REACHING THE GREAT LAKES REGION TUE NIGHT INTO WED AND THEN TRACKING OFF THE NORTHEASTERN US COAST WED NIGHT INTO THU. THIS SYSTEM WILL SEND A COLD FRONT INTO THE LOCAL AREA ON WED WITH THE MODEL CONSENSUS SHIFTING THIS FRONT SOUTH OF THE AREA ON WED NIGHT. ALTHOUGH I HAVE ALLOWED FOR SOME 10 POPS WHICH ARE PART OF THE MODEL CONSENSUS ON TUE AFTERNOON AS THE PAST COUPLE OF ECMWF RUNS DEVELOP SOME CONVECTION OVER THE NORTHEASTERN OR EASTERN PART OF THE CWA IN THE VICINITY OF THE SFC TROUGH/WARM FRONT FEATURE ON TUE...THE BEST CHANCE DURING THE PERIOD FOR MEASURABLE PRECIP WILL COME ON WED INTO WED EVENING. AS FOR TEMPERATURES...MAX TEMPERATURES SHOULD GENERALLY AVERAGE SLIGHTLY ABOVE NORMAL EARLY IN THE PERIOD AND AT THE END OF THE PERIOD TO AS MUCH AS 10 DEGREES OR MORE ABOVE NORMAL ON WED JUST AHEAD OF THE COLD FRONT. LOW THROUGH THE PERIOD SHOULD GENERALLY BE IN THE 40S OR EVEN THE 50S...WITH ONE EXCEPTION...MONDAY NIGHT. SFC HIGH PRESSURE SHOULD ALLOW FOR SOME OF THE NORMALLY COLDER VALLEY LOCATIONS IN THE FAR NORTH AND EAST TO REACH THE UPPER 30S ON MON NIGHT. THIS WOULD LEAD TO AT LEAST A SLIGHT CONCERN FOR SOME PATCHY FROST AT LEAST IF THESE MIN TEMPS WERE TO TREND SLIGHTLY COLDER AS RECENT WARM WEATHER HAS ALLOWED VEGETATION TO BE RUNNING A COUPLE OF WEEKS OR SO AHEAD OF AVERAGE. HOWEVER...ATTM...EVEN IT ONE WERE TO OCCUR IT APPEARS AS IF IT WOULD BE VERY PATCHY TO ISOLATED AND WOULD OCCUR IN THE COLDEST OF THE NORMALLY COLD SPOTS. THIS POTENTIAL SCENARIO WILL CONTINUE TO BE MONITORED...HOWEVER CONFIDENCE IN EVEN ISOLATED TO PATCHY VALLEY FROST IS TOO LOW AT THIS POINT TO INCLUDE IN THE HWO. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 145 AM EDT SAT MAR 24 2012 CONCERNING AVIATION TONIGHT...THE MAIN THREAT IS WITH THE LINE OF SHOWERS AND THUNDERSTORMS MOVING THROUGH EASTERN KENTUCKY. IFR TO MVFR FLIGHT CONDITIONS WILL BE ASSOCIATED WITH THE LINE AS IT MOVES THROUGH. GOING BY TIMING...THE LINE IS EXPECTED TO MOVE THROUGH THE AREA BY 12Z. CONCERNING THE CLEARING BEHIND THE LINE...SOME FOG IS EXPECTED TO DEVELOP IN THE VALLEYS ESPECIALLY WHERE THE HEAVIEST RAIN HAS FALLEN SO PUT IFR CONDITIONS IN THE TAF SITES LATER TONIGHT AS THE SURFACE TEMPS DROP A BIT. WITH ANOTHER VORT LOBE ROTATING AROUND THE LOW LATER IN THE DAY...AND WITH THE DAYTIME HEATING...THE THREAT OF SHOWERS AND THUNDERSTORMS WILL DEVELOP LATER IN THE DAY SO THIS WAS PUT INTO THE TAFS AS WELL. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SHALLENBERGER LONG TERM....JP AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
145 AM EDT SAT MAR 24 2012 .UPDATE... ISSUED AT 145 AM EDT SAT MAR 24 2012 A LINE OF SHOWERS AND THUNDERSTORMS CONTINUE TO MOVE THROUGH EASTERN KENTUCKY AT THIS HOUR. HAVE UPDATED THE POPS TO MIRROR THIS LINE AND THE TIMING AS IT MOVES THROUGH THE AREA. THE ACTIVITY AS OF 0535Z SEEM TO BE WEAKENING AS THE AMOUNT OF INSTABILITY EAST OF THE I-75 CORRIDOR DROPS OFF SIGNIFICANTLY AS SHOWN BY SURFACE ANALYSIS. WILL STILL KEEP THE THREAT OF HEAVY DOWNPOURS IN THE FORECAST AS STILL ALOT OF UPPER LEVEL DYNAMICS AND MOISTURE WILL BE AVAILABLE THROUGH THE NIGHT. WILL MONITOR THE PROGRESSION OF THIS ACTIVITY AND PROVIDE ANOTHER UPDATE BY 0830Z. UPDATE ISSUED AT 1043 PM EDT FRI MAR 23 2012 NDFD AND ASSOCIATED PRODUCTS HAVE BEEN UPDATED FOR LATEST OBSERVATIONAL TRENDS. PREVIOUS TIMING ON CONVECTION FOR THE REMAINDER OF THE NIGHT STILL LOOKS GOOD BASED ON LATEST RADAR TRENDS AND SHORT RANGE MODEL DATA. CONVECTION IS NEARING THE SOUTHWEST PART OF THE FORECAST AREA AT THIS TIME. LATEST HRRR SEEMS TO HAVE A PRETTY GOOD HANDLE ON THE CONVECTION...AND EXPECT INTENSITY OF SHOWERS AND THUNDERSTORMS TO DECREASE OVERNIGHT PER THE 23Z HRRR. HAVE CONTINUE WITH THE IDEA OF SCATTERED SHOWERS AND THUNDERSTORMS. SOME REPORTS OF FOG IN LOCAL VALLEY AREAS AND WILL ADD THIS TO THE HWO. UPDATE ISSUED AT 747 PM EDT FRI MAR 23 2012 SCATTERED SHOWERS CURRENTLY EAST OF A LINE FROM MOREHEAD TO WHITESBURG CONTINUE TO DIMINISH IN COVERAGE AND INTENSITY AS THEY MOVE NORTHEAST AT 40 MPH. ALSO AN SHOWER MOVING INTO WAYNE COUNTY AT THIS TIME. FOR THE MOST PART EXPECT DRY WEATHER TO PREVAIL FOR THE REST OF THE EVENING WITH ONLY ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE. SHOWERS AND THUNDERSTORMS CURRENTLY INCREASING FROM NORTH OF BOWLING GREEN INTO CENTRAL INDIANA. AS LOW AND SURFACE FRONT MOVE EAST TONIGHT EXPECT SHOWERS AND THUNDERSTORMS TO ONCE AGAIN BECOME MORE NUMEROUS IN EASTERN KY...GENERALLY AFTER MIDNIGHT. THIS IS IN AGREEMENT WITH CURRENT TRENDS AND THE LATEST HRRR AND NAM. FOR NOW WILL KEEP PRECIPITATION SCATTERED IN NATURE LATER TONIGHT WITH 50 PERCENT PROBABILITIES. HAVE ALSO MADE SOME MINOR UPDATES TO NDFD FOR LATEST SURFACE OBSERVATIONAL TRENDS. UPDATE ISSUED AT 441 PM EDT FRI MAR 23 2012 HAVE UPDATED NDFD OUT THROUGH THE NEXT SEVERAL HOURS FOR LATEST OBSERVATIONAL TRENDS. LATEST SHORT RANGE GUIDANCE STILL POINTS TOWARDS A DECREASING CHANCE OF SHOWERS AND THUNDERSTORMS AFTER 00Z AS THE CURRENT ACTIVITY NOW AFFECTING EASTERN KY MOVES NORTHEAST OF THE AREA. THE CHANCE WILL THEN RAMP UP AGAIN LATER TONIGHT AS THE CLOSED UPPER LOW MOVES EAST. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 306 PM EDT FRI MAR 23 2012 SAT IMAGERY AND SFC ANALYSIS AS OF 18Z SHOWS THE CENTER OF A BROAD STACKED LOW NOW MOVING FROM MO INTO IL. CONVECTION OVER ERN KY HAS BEEN RATHER ANEMIC THUS FAR LARGELY DUE TO THE EXTENSIVE CLOUD COVER INHIBITING INSTABILITY. HOWEVER...BLENDED PWAT PRODUCT SHOWS THE AXIS OF AMPLE MOISTURE TRANSPORT FROM THE GOMEX STILL ALIGNED FROM SRN AL UP THRU MIDDLE TN AND INTO CENTRAL KY....FUELING WIDESPREAD SHOWERS OVER ERN KY WITH LIGHTNING JUST NOW STARTING TO PICK UP OVER OUR AREA...ALONG WITH A HINT OF ROTATION IN A CELL MOVING INTO LESLIE COUNTY SUGGESTING AT LEAST A POTENTIAL FOR HAIL MAY STILL EXIST THROUGH THE REMAINDER OF THE FIRST PERIOD AS WELL. CURRENT RADAR TRENDS OVER WRN KY WHERE CONVECTION HAS BEEN NOTABLY DEEPER SUGGEST 12Z MODELS MAY NOT BE TOO FAR OFF THE MARK WITH THE IDEA OF A SOLID LULL IN ACTIVITY OVERNIGHT. HOWEVER...STILL WOULD NOT RULE OUT A STRONG TSTM OR TWO THRU THIS EVENING WITH IR INDICATING SOME ENHANCEMENT IN THE CONVECTION MOVING UP FROM ERN TN. GUIDANCE REMAINS IN GOOD AGREEMENT FOR SATURDAY BRINGING LOWERING HEIGHTS ALOFT AS THE BROAD LOW APPROACHES WITH STEEPENING LAPSE RATES THROUGH THE AFTERNOON IN RESPONSE...WARRANTING ANOTHER ROUND OF CHANCE TSTMS THRU THE MORNING AND INTO THE AFTERNOON...THOUGH WITH SIGNIFICANTLY LESS SEVERE POTENTIAL THAN TODAY. BY SATURDAY NIGHT...MODELS BEGIN TO DIVERGE WITH THE TRACK OF THE UPPER LOW AND THIS WILL UNDOUBTEDLY HAVE AN INFLUENCE ON THE SFC TRACK AND POPS AS WELL. HAVE LEANED MORE TOWARDS THE ECMWF AFTER 00Z SUNDAY FOR THE SYNOPTIC PICTURE AS IT APPEARS TO HAVE THE MORE CONSISTENT SOLUTION. THIS WOULD MOVE THE CORE OF THE UPPER LOW INTO SERN KY BY SUNDAY MORNING BEFORE EXITING THE COMMONWEALTH...LEAVING A DEEP NW FLOW OVERHEAD WITH A POTENTIAL FOR A GOOD FETCH OF MOISTURE OFF THE GREAT LAKES AND POSSIBLY JUST ENOUGH RESIDUAL MID LEVEL ENERGY ON THE BACKSIDE OF THE DEPARTING SYSTEM TO AFFECT A FEW SHOWERS ACROSS THE CWA ON SUNDAY. BUFR SOUNDINGS ATTM INDICATE MINIMAL INSTABILITY THROUGH THE DAY AND HAVE KEPT SLIGHT CHANCE WORDING FOR TSTMS FOR THE MOMENT...THOUGH IF MODEL TRENDS CONTINUE THEN THE NEXT ISSUANCE COULD PROBABLY PULL THUNDER FROM SUNDAY AND JUST LEAVE ISOLATED SHOWERS. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 306 PM EDT FRI MAR 23 2012 PATTERN IS QUITE PROGRESSIVE THROUGH THE EXTENDED PERIOD. ALSO... MODELS ARE IN GOOD AGREEMENT UNTIL DY7 WHEN SOLUTIONS DISPLAY A SIGNIFICANT DEPARTURE...ESPECIALLY THE GFS. HOWEVER...TREND HAS BEEN TOWARDS THE ECMWF SOLUTION. A FAST MOVING SHORT WAVE RIDGE TRANSITS OUR AREA AT THE START OF THE EXTENDED BEHIND EXITING LOW OFF THE ATLANTIC COAST. BUT SHORT WAVE ENERGY DIGGING SOUTHEASTWARD ACROSS THE GREAT LAKES LATE MONDAY NIGHT INTO TUESDAY MORNING WILL SEND A BACK DOOR SFC FRONT INTO THE CWA. BUT THIS FEATURE STALLS OUT ACROSS OUR AREA TUESDAY BEFORE SHOOTING BACK TO OUR NORTH AS OUR NEXT WEATHER MAKER ROLLS OUT OF THE NORTHERN PLAINS...PULLING A COLD FRONT THROUGH EASTERN KENTUCKY MID WEEK...PROBABLY WEDNESDAY. DRY WEATHER TAKES OVER AS CANADIAN HIGH PRESSURE NOSES ITS WAY INTO THE OHIO VALLEY REGION TO CLOSE OUT THE WEEK. IN GENERAL TEMPERATURES WILL COOL THROUGH THE PERIOD AS COMPARED TO OUR RECENT RECORD HIGHS...BUT STILL REMAIN ABOVE NORMAL. LOOK FOR HIGHS AROUND 70...EXCEPT MID 70S ON WEDNESDAY AND LOWS IN THE UPPER 40S TO LOWER 50S THROUGH THE FORECAST PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 145 AM EDT SAT MAR 24 2012 CONCERNING AVIATION TONIGHT...THE MAIN THREAT IS WITH THE LINE OF SHOWERS AND THUNDERSTORMS MOVING THROUGH EASTERN KENTUCKY. IFR TO MVFR FLIGHT CONDITIONS WILL BE ASSOCIATED WITH THE LINE AS IT MOVES THROUGH. GOING BY TIMING...THE LINE IS EXPECTED TO MOVE THROUGH THE AREA BY 12Z. CONCERNING THE CLEARING BEHIND THE LINE...SOME FOG IS EXPECTED TO DEVELOP IN THE VALLEYS ESPECIALLY WHERE THE HEAVIEST RAIN HAS FALLEN SO PUT IFR CONDITIONS IN THE TAF SITES LATER TONIGHT AS THE SURFACE TEMPS DROP A BIT. WITH ANOTHER VORT LOBE ROTATING AROUND THE LOW LATER IN THE DAY...AND WITH THE DAYTIME HEATING...THE THREAT OF SHOWERS AND THUNDERSTORMS WILL DEVELOP LATER IN THE DAY SO THIS WAS PUT INTO THE TAFS AS WELL. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SHALLENBERGER SHORT TERM...MB LONG TERM....RAY AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
719 AM EDT SAT MAR 24 2012 .SYNOPSIS... LOW PRESSURE WILL PROVIDE SHOWERS INTO SUNDAY AS TEMPERATURES COOL TO VALUES COMMON FOR MAY. CANADIAN HIGH PRESSURE WILL FOLLOW WITH DRY SEASONABLE CONDITIONS MONDAY, WHICH MEANS THERE CAN BE A FROST MONDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SHOWERS ARE STREAMING INTO SOUTHERN OHIO AS 850 MB LOW MOVES SLOWLY EAST ACROSS THE OHIO VALLEY. SHOWERS WILL BE LIKELY ACROSS THE FORECAST AREA TODAY WITH AN INCREASING CHANCE OF THUNDER WITH THE HEATING OF THE DAY. SPC HAS MENTIONED SEVERE POTENTIAL WILL BE LIMITED AS SREF MODEL OUTPUT SHOWS WEAK INSTABILITY AND VERTICAL SHEAR. CONSENSUS OF GFS AND NAM MOS MAINTAIN MAINLY CLOUDY SKIES TODAY, AND SO THE STRING OF RECORD WARM TEMPERATURES SHOULD END. PITTSBURGH HAS HAD ELEVEN CONSECUTIVE MARCH DAYS OF 70 PLUS, BUT MAY STRUGGLE TO REACH 70 TODAY TO RUN THE STRING TO TWELVE. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... RECENT SREF MODEL OUTPUT CONTINUES TO SHOW POST-SYSTEM SHOWERS MAY LINGER ACROSS THE UPPER OHIO VALLEY INTO LATE SUNDAY AS THE LOW PRESSURE SYSTEM EXITS EAST THROUGH VIRGINIA. ENSUING CANADIAN HIGH PRESSURE WILL PROVIDE DRYING BY MONDAY. NORTH WINDS AHEAD OF THE HIGH PRESSURE WILL FUNNEL SEASONABLE COLD TEMPERATURES INTO THE UPPER OHIO VALLEY. CLEAR SKIES AND LIGHT WINDS MONDAY NIGHT CAN CAUSE FROST TO DEVELOP IN MANY AREAS. SUCH A FROST OCCURRENCE IS TYPICAL FOR LATE MARCH, BUT THIS ONE MAY HAVE HIGH IMPACT ON THE HEELS OF THE RECENT WARM SPELL THAT HAS SPURRED AN EARLY START TO THE GROWING SEASON. THIS THREAT HAS BEEN HIGHLIGHTED IN THE HAZARDOUS WEATHER OUTLOOK/HWO/. && .LONG TERM /TUESDAY THROUGH FRIDAY/... BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOW DRY SEASONABLE CONDITIONS CONTINUING ACROSS THE UPPER OHIO VALLEY TUESDAY AS THE CANADIAN HIGH PRESSURE EXITS EAST. A MORE ZONAL UPPER LEVEL JETSTREAM WILL STEER A WYOMING-BRED LOW PRESSURE SYSTEM EASTBOUND TO BRING SHOWERS WEDNESDAY. HIGH PRESSURE WILL FOLLOW WITH DRY CONDITIONS THURSDAY AND FRIDAY. AS MENTIONED, TEMPERATURES WILL BE CLOSER TO NORMAL THIS PERIOD, ALTHOUGH THERE MAY BE A WARM UP TO 10 DEGREES WARMER THAN NORMAL WEDNESDAY IF THE LOW PRESSURE SYSTEM MOVES SLOWER THAN CURRENTLY FORECASTED. && .AVIATION /11Z SATURDAY THROUGH WEDNESDAY/... AN AREA OF IFR CIGS/VIS IS QUICKLY DEVELOPING ACROSS PORTIONS OF W PA IN THE MOISTURE LL ATMOSPHERE. WILL KEEP THESE LOW CONDITIONS THROUGH DAWN. WILL NEED TO WATCH ZZV, AS CIGS AND VIS THERE ARE ALSO DROPPING. OBS TO THE SOUTH OF ZZV, ARE SHOWING IFR CONDITIONS, SO WILL INCLUDE TEMPO GROUP FOR NOW. BLEND OF RECENT SURFACE AND RADAR DATA COUPLED WITH HRRR MODEL OUTPUT SHOW A BAND OF MVFR SHOWERS WILL PASS NORTHEASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH 12Z. EVAPORATION OF THE RAIN MAY MAINTAIN MVFR CONDITIONS INTO 15Z. A SECOND BAND OF SHOWERS, PERHAPS EMBEDDED WITH SCATTERED THUNDERSTORMS, WILL PASS THROUGH THIS AFTERNOON, AND PROLONG MVFR RESTRICTIONS. SPC HAS MENTIONED WEAK SEVERE POTENTIAL WITH THE THUNDERSTORMS. FOR AVIATION, THE MAIN CONCERN WOULD BE HAIL ALOFT. POST SYSTEM COOLING MAY MAINTAIN A NEAR SATURATED SURFACE LAYER INTO TONIGHT AND SUNDAY WHICH COULD RESULT IN LINGERING MVFR RESTRICTIONS. OUTLOOK...SUNDAY NIGHT THROUGH TUESDAY... CANADIAN HIGH PRESSURE SHOULD PROVIDE VFR MONDAY INTO TUESDAY. COLD FRONTAL SHOWERS MAY CAUSE RESTRICTIONS LATE TUESDAY INTO WEDNESDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
414 AM EDT SAT MAR 24 2012 .SYNOPSIS... LOW PRESSURE, MOVING EAST FROM KENTUCKY, WILL PROVIDE SHOWERS INTO SUNDAY AS TEMPERATURES COOL TO VALUES COMMON FOR MAY. CANADIAN HIGH PRESSURE WILL FOLLOW WITH DRY SEASONABLE CONDITIONS MONDAY, WHICH MEANS THERE CAN BE A FROST MONDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... BAND OF SHOWERS CONTINUES TO SLOWLY DRIFT EASTWARD, AS THE RAIN IN THE BAND IS MOVING NORTHWARD. AREAS OF FOG HAVE ALSO DEVELOPED IN THE MOIST ATMOSPHERE, SO WILL NEED TO MENTION PATCHY FOG THROUGH DAWN. HI-RES MODEL OUTPUT SHOWS THERE MAY BE A DRY BREAK SATURDAY MORNING, FOLLOWED BY A BAND OF SHOWERS SATURDAY AFTERNOON THAT MAY INCLUDE THUNDERSTORMS. SPC HAS MENTIONED SEVERE POTENTIAL WILL BE LIMITED AS SREF MODEL OUTPUT SHOWS WEAK INSTABILITY AND VERTICAL SHEAR. INSTABILITY WILL HAVE TO MONITORED TODAY IF THE DRY BREAK PRODUCES A PERIOD OF SUNSHINE WHICH CAUSE AN UPWARD SPIKE IN SURFACE TEMPERATURES. CONSENSUS OF GFS AND NAM MOS MAINTAIN MAINLY CLOUDY SKIES TODAY, AND SO THE STRING OF RECORD WARM TEMPERATURES SHOULD END. PITTSBURGH HAS HAD ELEVEN CONSECUTIVE MARCH DAYS OF 70 PLUS, BUT MAY STRUGGLE TO REACH 70 TODAY TO RUN THE STRING TO TWELVE. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... RECENT SREF MODEL OUTPUT CONTINUES TO SHOW POST-SYSTEM SHOWERS MAY LINGER ACROSS THE UPPER OHIO VALLEY INTO LATE SUNDAY AS THE LOW PRESSURE SYSTEM EXITS EAST THROUGH VIRGINIA. ENSUING CANADIAN HIGH PRESSURE WILL PROVIDE DRYING BY MONDAY. NORTH WINDS AHEAD OF THE HIGH PRESSURE WILL FUNNEL SEASONABLE COLD TEMPERATURES INTO THE UPPER OHIO VALLEY. CLEAR SKIES AND LIGHT WINDS MONDAY NIGHT CAN CAUSE FROST TO DEVELOP IN MANY AREAS. SUCH A FROST OCCURRENCE IS TYPICAL FOR LATE MARCH, BUT THIS ONE MAY HAVE HIGH IMPACT ON THE HEELS OF THE RECENT WARM SPELL THAT HAS SPURRED AN EARLY START TO THE GROWING SEASON. THIS THREAT HAS BEEN HIGHLIGHTED IN THE HAZARDOUS WEATHER OUTLOOK/HWO/. && .LONG TERM /TUESDAY THROUGH FRIDAY/... BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOW DRY SEASONABLE CONDITIONS CONTINUING ACROSS THE UPPER OHIO VALLEY TUESDAY AS THE CANADIAN HIGH PRESSURE EXITS EAST. A MORE ZONAL UPPER LEVEL JETSTREAM WILL STEER A WYOMING-BRED LOW PRESSURE SYSTEM EASTBOUND TO BRING SHOWERS WEDNESDAY. HIGH PRESSURE WILL FOLLOW WITH DRY CONDITIONS THURSDAY AND FRIDAY. AS MENTIONED, TEMPERATURES WILL BE CLOSER TO NORMAL THIS PERIOD, ALTHOUGH THERE MAY BE A WARM UP TO 10 DEGREES WARMER THAN NORMAL WEDNESDAY IF THE LOW PRESSURE SYSTEM MOVES SLOWER THAN CURRENTLY FORECASTED. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... AN AREA OF IFR CIGS/VIS IS QUICKLY DEVELOPING ACROSS PORTIONS OF W PA IN THE MOISTURE LL ATMOSPHERE. WILL KEEP THESE LOW CONDITIONS THROUGH DAWN. WILL NEED TO WATCH ZZV, AS CIGS AND VIS THERE ARE ALSO DROPPING. OBS TO THE SOUTH OF ZZV, ARE SHOWING IFR CONDITIONS, SO WILL INCLUDE TEMPO GROUP FOR NOW. BLEND OF RECENT SURFACE AND RADAR DATA COUPLED WITH HRRR MODEL OUTPUT SHOW A BAND OF MVFR SHOWERS WILL PASS NORTHEASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH 12Z. EVAPORATION OF THE RAIN MAY MAINTAIN MVFR CONDITIONS INTO 15Z. A SECOND BAND OF SHOWERS, PERHAPS EMBEDDED WITH SCATTERED THUNDERSTORMS, WILL PASS THROUGH THIS AFTERNOON, AND PROLONG MVFR RESTRICTIONS. SPC HAS MENTIONED WEAK SEVERE POTENTIAL WITH THE THUNDERSTORMS. FOR AVIATION, THE MAIN CONCERN WOULD BE HAIL ALOFT. POST SYSTEM COOLING MAY MAINTAIN A NEAR SATURATED SURFACE LAYER INTO TONIGHT AND SUNDAY WHICH COULD RESULT IN LINGERING MVFR RESTRICTIONS. OUTLOOK...SUNDAY NIGHT THROUGH TUESDAY... CANADIAN HIGH PRESSURE SHOULD PROVIDE VFR MONDAY INTO TUESDAY. COLD FRONTAL SHOWERS MAY CAUSE RESTRICTIONS LATE TUESDAY INTO WEDNESDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
400 AM EDT SAT MAR 24 2012 .SYNOPSIS... LOW PRESSURE OVER THE OHIO VALLEY WILL APPROACH TODAY...AND WILL MOVE ACROSS THE SOUTHERN MID-ATLANTIC REGION TONIGHT INTO SUNDAY. A DRY COLD FRONT MOVES THROUGH ON MONDAY...THEN HIGH PRESSURE BUILDS IN FOR TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... BACKDOOR FRONT WILL CONTINUE TO SINK SOUTH AND LIKELY STALL ACROSS THE SOUTHERN PORTION OF THE CWA EARLY THIS MORNING. MEANWHILE...THERE/S ALREADY SOME PVA/WAA MAKING ITS WAY INTO THE CWA WELL AHEAD OF LOW PRESSURE OVER THE OHIO VALLEY. RESULT IS SHOWERS ACROSS THE WESTERN PORTIONS OF THE CWA WHICH WILL GRADUALLY SPREAD TO THE EAST/EXPAND THROUGH THE MORNING HOURS...POSSIBLY EXITING DURING THE EARLY AFTERNOON. FAST ON ITS HEELS WITH LIKELY BE ANOTHER ROUND OF SHOWERS AS LOW PRESSURE/COLD FRONT MOVE INTO THE APPALACHIANS. THERE MAY NOT BE A HUGE TIME LULL IN BETWEEN ROUNDS...SO AM UNCERTAIN HOW MUCH IF ANY BREAKS IN THE CLOUD COVER MAY DEVELOP FOR THE AFTERNOON. THE BEST AREA FOR THIS MAY BE ACROSS CENTRAL VIRGINIA SOUTH OF THE AFOREMENTIONED STALLED BOUNDARY. EVEN WITHOUT BREAKS...WITH HIGH DEWPOINTS AND PW/S AND ALSO SOME COOLING ALOFT...THERE MAY BE THUNDERSTORMS THAT ACCOMPANY THE SHOWERS LATER IN THE AFTERNOON/EVENING. MAIN CONCERN GIVEN HIGH MOISTURE CONTENT WILL BE HEAVY RAINFALL AND LOCALIZED FLASH FLOODING...ALTHOUGH FLASH FLOOD GUIDANCE IS FAIRLY HIGH. ALSO CAN/T RULE OUT ISOLATED STRONG TO MARGINALLY SEVERE STORMS /HAIL/ ESPECIALLY CENTRAL VIRGINIA WHICH IS WHERE SREFS HAS MAINTAINED CONSISTENCY IN A CHANCE OF MUCAPE GTE 1000 J/KG AND 0-6 KM SHEAR 30 KT. BUT AGAIN...INSTABILITY MAGNITUDE IS SOMEWHAT CONTINGENT ON WHETHER THERE CAN BE BREAKS OR NOT. LEANED MORE TOWARD THE COOLER MET MOS ESPECIALLY NORTH OF THE BOUNDARY IN AN EASTERLY FLOW. BUT GIVEN CLOUDS/SHOWERS...EVEN AREA FURTHER SOUTH INTO CENTRAL VIRGINIA SHOULD FAVOR THE COOLER GUIDANCE. LOW PRESSURE MOVES ACROSS THE THE SOUTHERN PORTIONS OF THE CWA OVERNIGHT. EXPECT MORE SHOWERS TO CONTINUE...AND ITS POSSIBLE THAT A BAND OF LOCALLY HEAVY SHOWERS MAY OCCUR ON THE NORTH SIDE OF THE LOW. && .SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/... THE CLOSED LOW IS FCST TO REACH THE LEE SIDE OF THE SOUTHERN/CENTRAL APPALACHIANS BY SUN MRNG BEFORE SLOWLY REACHING THE CAROLINA COAST SUN AFTN. THE BEST SYNOPTIC LIFT AND ACCORDINGLY THE STEADIEST/ HEAVIEST PRECIP WILL SHIFT WELL SOUTH AND EAST OF THE AREA SUN. THE CWA WILL BE LOCATED ON NRN PERIPHERY OF THE LOW...WHERE LGT PRECIP IS EXPECTED NEAR MID-LVL DEFORMATION AXIS. SHOWER ACTIVITY WILL BE AIDED BY WEAK INSTABILITY DURING THE AFTN FROM THE COLD POOL ALOFT AND LIMITED BOUNDARY LAYER HEATING. HAVE ADDED SLIGHT CHANCE FOR TSTMS SUN AFTN AS FAR NORTH AS WOO-IAD-DMH. SHEAR-INSTABILITY PROFILES DO NOT INDICATE A SEVERE WEATHER THREAT. QPF AMOUNTS ARE AROUND A QUARTER INCH ON SUN. MAX TEMP FCST A BIT TRICKY DUE TO VARIABLE CLOUD COVER OVER THE REGION. ATTM...MAX TEMPS RANGE FROM THE MID 60S OVER THE MTS AND NEAR THE MASON-DIXON LINE TO THE LOW 70S IN CENTRAL VA AND SRN MD. THE LOW WILL FINALLY MOVE OFF THE COAST. SHOWER ACTIVITY SHOULD DIMINISH DURING THE EVE WITH THE LOSS OF DAYTIME HEATING AND AS DRIER AIR MOVES IN ALOFT. SKIES MAY EVEN GO PARTLY CLOUDY BY DAWN MON MRNG. && .LONG TERM /MONDAY THROUGH FRIDAY/... COOL CANADIAN AIR WILL FINALLY PUSH FAR ENOUGH SOUTH TO IMPACT THE MID-ATLANTIC STATES FOR THE FIRST TIME IN OVER TWO WEEKS. NRN-STREAM ENERGY IS EXPECTED TO DIG SEWD INTO THE NE STATES ON MON. NW FLOW BEHIND THE LOW WILL DRIVE COLDER AIR SWD INTO THE AREA THRUOUT THE DAY. STRONG CAA SHOULD OFFSET DAYTIME HEATING SOMEWHAT. TEMPS ARE STILL EXPECTED TO REACH THE 60S AND EVEN 70F ACROSS CENTRAL VA/SRN WITH THE AIDE OF THE INCREASING SUN ANGLE OF ERY SPRING. HIPRES BUILDS INTO THE AREA MON NGT. THE COLDEST NGT SINCE THE FIRST WEEK OF MARCH IS EXPECTED MON NGT. AS PREVIOUS FORECASTER IMPLIED...CAA PATTERN AND DECENT PRESSURE GRADIENT FROM HIPRES BUILDING SWD SHOULD PREVENT WINDS FROM DECOUPLING AND WIDESPREAD FROST. SHELTERED VLYS WITHIN THE POTOMAC HIGHLANDS MAY FLIRT WITH THE FREEZING MARK. HIPRES/UPPER RIDGE OVER THE AREA TUE WILL GRADUALLY SHIFT OFF THE COAST WED. AFTER MAX TEMPS FINALLY RETURN TOWARD NORMAL LVLS FOR LATE MARCH ON TUE /UPPER 50S AND LOW 60S/...WAA PATTERN WILL YIELD HIGHS IN THE UPPER 60S AND LOW 70S BY WED. THE NEXT CHANCE OF PRECIP WILL BE WED AS A COLD FRONT MOVES THRU THE REGION LATE WED INTO ERY THU. TEMPS RETURN TOWARD SEASONABLE LVLS LATE IN THE WORK WEEK. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... BACKDOOR BOUNDARY SINKING SOUTH WILL REINFORCE EASTERLY FLOW TODAY. ALREADY HAVE IFR CIGS CREEPING INTO MTN/BWI AT 07Z. HRRR SUGGESTS IFR CIGS MAKE IT TO IAD TOWARD DAYBREAK...AND FORECAST REFLECTS THIS ALTHOUGH HAVE SOME UNCERTAINTY REGARDING WESTWARD EXTENT AND TIMING OF STRATUS THIS MORNING. AT THE SAME TIME...THERE/S SHOWERS MOVING IN FROM THE WEST WELL OF AHEAD OF LOW PRESSURE OVER THE OHIO VALLEY. THESE SHOWERS WILL ALSO AFFECT THE TERMINALS FIRST CHO/MRB THEN SPREADING EAST AFTER DAYBREAK AT THE HUBS. EXPECT OCCASIONAL SHOWERS TODAY/TONIGHT...WITH THUNDERSTORMS ALSO POSSIBLE MAINLY THIS AFTERNOON/EVENING. AT LEAST MVFR FLIGHT RESTRICTIONS WILL ACCOMPANY SHOWERS TODAY...BUT GIVEN EASTERLY FLOW ON THE NORTH SIDE OF THE BOUNDARY THERE IS THE CHANCE THAT IFR CONDITIONS BECOME ENTRENCHED. IF THEY DO...THEY ARE LIKELY TO REMAIN THROUGH THE NIGHT AND LIKELY DROP TO LIFR OVERNIGHT. ON THE OTHER HAND...IF MVFR WINDS UP PREVAILING THE BULK OF THE DAY...THEN IFR/LIFR SHOULD RETURN THIS EVENING. IFR CIGS SUN MRNG MAY IMPROVE TO MVFR LVLS BY THE AFTN. EXACT EVOLUTION OF CIGS AND EVEN VSBYS WILL DEPEND ON SHRA COVERAGE DURING THIS TIME. CANNOT RULE OUT AN ISO TSTM SUN AFTN...ESPECIALLY SOUTH OF MRB-BWI-MTN. IMPROVING CONDITIONS LATE SUN NGT AS DRIER AIR WORKS IN FROM THE NORTH. DRY CONDITIONS EXPECTED MON AND TUE. NW WINDS WILL BE BREEZY ON MON...15-20 KT GUSTING TO 30 KT. && .MARINE... HIGH PRESSURE MOVES FURTHER AWAY FROM THE EASTERN SEABOARD AS LOW PRESSURE APPROACHES FROM THE WEST. RESULT WILL BE EASTERLY FLOW...THAT MAY INCREASE INTO THE 10 TO 15 KT RANGE TODAY. OCCASIONAL SHOWERS AND POSSIBLE THUNDERSTORMS WILL BRING VIS RESTRICTIONS OF 1 TO 3 NM FROM TIME TO TIME THROUGH TONIGHT. LOW PRESSURE LOOKS TO PASS OVER THE SOUTHERN WATER LATE TONIGHT. AN ISO TSTM POSSIBLE OVER THE WATERS SUN AFTN. N-NW FLOW WILL INCREASE SUN NGT AND MON BEHIND A COLD FRONT. SCA CONDITIONS POSSIBLE LATE SUN NGT AND LIKELY MON THRU A PORTION OF TUE. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...BPP/JRK NEAR TERM...BPP SHORT TERM...JRK LONG TERM...JRK AVIATION...BPP/JRK MARINE...BPP/JRK
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
242 AM EDT SAT MAR 24 2012 .SYNOPSIS... LOW PRESSURE, MOVING EAST FROM KENTUCKY, WILL PROVIDE SHOWERS INTO SUNDAY AS TEMPERATURES COOL TO VALUES COMMON FOR MAY. CANADIAN HIGH PRESSURE WILL FOLLOW WITH DRY SEASONABLE CONDITIONS MONDAY, WHICH MEANS THERE CAN BE A FROST MONDAY NIGHT. && .NEAR TERM /THROUGH TODAY/... BLEND OF RECENT RADAR DATA AND HRRR MODEL OUTPUT SHOW A BAND OF SHOWERS, ASSOCIATED WITH THE CIRCULATION AROUND THE LOW PRESSURE CENTER MOVING EAST FROM KENTUCKY, WILL PASS NORTHEASTWARD THROUGH THE UPPER OHIO VALLEY UNTIL MORNING. TEMPERATURES WILL AT MOST ONLY DROP 2 OR 3 DEGREES FOR OVERNIGHT LOWS. HI-RES MODEL OUTPUT SHOWS THERE MAY BE A DRY BREAK SATURDAY MORNING, FOLLOWED BY A BAND OF SHOWERS SATURDAY AFTERNOON THAT MAY INCLUDE THUNDERSTORMS. SPC HAS MENTIONED SEVERE POTENTIAL WILL BE LIMITED AS SREF MODEL OUTPUT SHOWS WEAK INSTABILITY AND VERTICAL SHEAR. INSTABILITY WILL HAVE TO MONITORED TODAY IF THE DRY BREAK PRODUCES A PERIOD OF SUNSHINE WHICH CAUSE AN UPWARD SPIKE IN SURFACE TEMPERATURES. CONSENSUS OF GFS AND NAM MOS MAINTAIN MAINLY CLOUDY SKIES TODAY, AND SO THE STRING OF RECORD WARM TEMPERATURES SHOULD END. PITTSBURGH HAS HAD ELEVEN CONSECUTIVE MARCH DAYS OF 70 PLUS, BUT MAY STRUGGLE TO REACH 70 TODAY TO RUN THE STRING TO TWELVE. && .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... RECENT SREF MODEL OUTPUT CONTINUES TO SHOW POST-SYSTEM SHOWERS MAY LINGER ACROSS THE UPPER OHIO VALLEY INTO LATE SUNDAY AS THE LOW PRESSURE SYSTEM EXITS EAST THROUGH VIRGINIA. ENSUING CANADIAN HIGH PRESSURE WILL PROVIDE DRYING BY MONDAY. NORTH WINDS AHEAD OF THE HIGH PRESSURE WILL FUNNEL SEASONABLE COLD TEMPERATURES INTO THE UPPER OHIO VALLEY. CLEAR SKIES AND LIGHT WINDS MONDAY NIGHT CAN CAUSE FROST TO DEVELOP IN MANY AREAS. SUCH A FROST OCCURRENCE IS TYPICAL FOR LATE MARCH, BUT THIS ONE MAY HAVE HIGH IMPACT ON THE HEELS OF THE RECENT WARM SPELL THAT HAS SPURRED AN EARLY START TO THE GROWING SEASON. THIS THREAT HAS BEEN HIGHLIGHTED IN THE HAZARDOUS WEATHER OUTLOOK/HWO/. && .LONG TERM /TUESDAY THROUGH FRIDAY/... BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOW DRY SEASONABLE CONDITIONS CONTINUING ACROSS THE UPPER OHIO VALLEY TUESDAY AS THE CANADIAN HIGH PRESSURE EXITS EAST. A MORE ZONAL UPPER LEVEL JETSTREAM WILL STEER A WYOMING-BRED LOW PRESSURE SYSTEM EASTBOUND TO BRING SHOWERS WEDNESDAY. HIGH PRESSURE WILL FOLLOW WITH DRY CONDITIONS THURSDAY AND FRIDAY. AS MENTIONED, TEMPERATURES WILL BE CLOSER TO NORMAL THIS PERIOD, ALTHOUGH THERE MAY BE A WARM UP TO 10 DEGREES WARMER THAN NORMAL WEDNESDAY IF THE LOW PRESSURE SYSTEM MOVES SLOWER THAN CURRENTLY FORECASTED. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... BLEND OF RECENT SURFACE AND RADAR DATA COUPLED WITH HRRR MODEL OUTPUT SHOW A BAND OF MVFR SHOWERS WILL PASS NORTHEASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH 12Z. EVAPORATION OF THE RAIN MAY MAINTAIN MVFR CONDITIONS INTO 15Z. A SECOND BAND OF SHOWERS, PERHAPS EMBEDDED WITH SCATTERED THUNDERSTORMS, WILL PASS THROUGH THIS AFTERNOON, AND PROLONG MVFR RESTRICTIONS. SPC HAS MENTIONED WEAK SEVERE POTENTIAL WITH THE THUNDERSTORMS. FOR AVIATION, THE MAIN CONCERN WOULD BE HAIL ALOFT. POST SYSTEM COOLING MAY MAINTAIN A NEAR SATURATED SURFACE LAYER INTO TONIGHT AND SUNDAY WHICH COULD RESULT IN LINGERING MVFR RESTRICTIONS. OUTLOOK...SUNDAY NIGHT THROUGH TUESDAY... CANADIAN HIGH PRESSURE SHOULD PROVIDE VFR MONDAY INTO TUESDAY. COLD FRONTAL SHOWERS MAY CAUSE RESTRICTIONS LATE TUESDAY INTO WEDNESDAY. && .CLIMATE... AS OF FRIDAY, PITTSBURGH HAS HAD 11 CONSECUTIVE MARCH DAYS WITH HIGHS OF 70 PLUS. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
757 PM EDT SUN MAR 25 2012 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 454 PM EDT SUN MAR 25 2012 LOW CLOUDS HAVE BEEN VERY PERSISTENT TODAY...AS THE H875 INVERSION HAS BEEN DIFFICULT TO ERRODE. AWAY FROM THE COOLING OFF LK SUPERIOR...THE CLOUDS HAVE MIXED OUT...BUT STILL HAVE A DECENT SWATH OF CLOUDS OVER SRN ONTARIO NEAR THUNDER BAY. MEANWHILE...1033MB SFC HIGH JUST NE OF LK WINNIPEG AND AN ASSOCIATED SFC RIDGE HAS BEEN WORKING INTO WRN LK SUPERIOR. FARTHER SW...DEVELOPING LOW OVER WYOMING AS LED TO SOME MID LVL WAA AND CLOUDS OVER SD AND SRN MN. THESE CLOUDS SHOULD STAY S OF THE AREA TONIGHT AS THE UPPER TROUGH DIGS OVER THE NEW ENGLAND STATES AND BRINGS DRIER MID LVL AIR INTO THE UPPER GREAT LKS. ISSUE FOR TONIGHT WILL BE THE CLOUDS NEAR/OVER LK SUPERIOR. WITH THE WAY THEY HAVE HUNG IN TODAY OVER THE KEWEENAW AND ERN LK...FEELING IS THAT THERE IS A GOOD CHANCE OF THEM HANGING AROUND FOR MUCH OF THE NIGHT. THERE SHOULD BE PLENTY OF LK INSTABILITY...AS H950-925 TEMPS ARE AROUND -9C AND LK TEMPS AROUND 3-4C. QUESTION WILL BE IF THE MOISTURE WILL REMAIN. THE MODELS HAVE BEEN HAVING A DIFFICULT TIME WITH THIS MOISTURE AND MOST HAVE THE MOISTURE DIMINISHING THIS EVENING WITH THE CONTINUED SUBSIDENCE AND DRY AIR WITH THE SFC RIDGE. BUT THE PERSISTENCE OF THE CLOUDS OVER SRN ONTARIO AND CNTRL/ERN LK SUPERIOR CREATES CONCERN ON IT COMPLETELY DIMINISHING. HAVE BUMPED UP CLOUDS TO PARTLY CLOUDY NEAR LK SUPERIOR FOR THE OVERNIGHT HOURS...AS TO SUBSIDENCE...ANTICYCLONIC FLOW...AND DECREASING MOISTURE UNDER THE HIGH PRESSURE RIDGE MAY BE ENOUGH TO DIMINISH THEM. THAT BEING SAID...COULD EASILY SEE THE MOISTURE BECOMING TRAPPED WITH LOSS OF HEATING AND REMAINING WITH THE LK INSTABILITY. DID TRY TO SHOW SOME MOVEMENT TO THE PARTLY CLOUDY SKY AS H925 WINDS VEER THROUGH THE NIGHT...WHICH WOULD FOCUS THE CLOUDS OVER THE N THEN NE FAVORED LOCATIONS. IN ADDITION...13-16Z RUC RUNS TRY TO DEVELOP LK ENHANCED PCPN OVER CNTRL/ERN LK SUPERIOR THIS EVENING AND THEN DROP IT INTO UPPER MI. THE ONLY OTHER HIRES MODEL TO MENTION IT WAS THE REGIONAL GEM. WITH A FEW SHOWERS DEVELOPING TODAY DEVELOPMENT WOULDN/T BE SURPRISING...BUT WITH CONCERNS ON AMNT OF MOISTURE PRESENT DECIDED TO LEAVE OUT. LOWS TONIGHT HAVE HIGH BUST POTENTIAL DUE TO SEVERAL INFLUENCES. NEAR LK SUPERIOR...THE CLOUDS/WIND WILL BE THE MAIN FACTOR. THE COMBINATION OF THE TWO CREATES UNCERTAINTY AND HAVE STUCK WITH A MIDDLE GROUND IN THE UPPER 20S. FARTHER INLAND...TEMPS COULD REALLY TANK ONCE THE WINDS DIMINISH THIS EVENING AND IF SKIES REMAIN MOSTLY CLEAR. PWATS AROUND 0.25IN OR ABOUT 40 PERCENT OF NORMAL AND LIGHT WINDS CREATES A GOOD RADIATIONAL COOLING NIGHT AND EXPECT TEMPS TO FALL NEAR 20. IF THE CLOUDS REMAIN AWAY...COULD SEE VALUES EVEN COLDER INTO THE TEENS OVER THE INTERIOR WEST COLD SPOTS. MONDAY...HIGH PRESSURE CENTERED JUST SW OF JAMES BAY WILL KEEP THE SFC RIDGE OVER THE AREA...WHILE AN UPPER RIDGE WILL START TO BUILD OVER THE NRN PLAINS. RIDGE WILL GRADUALLY SHIFT E THROUGH THE DAY...AS SFC LOW DEVELOPS OVER ERN MONTANA/WYOMING. OTHER THAN THE PREVIOUSLY MENTIONED POTENTIAL FOR LINGERING LK CLOUDS IN THE MORNING...DRY AIR AND SUBSIDENCE FROM THE HIGH SHOULD LEAD TO A MOSTLY SUNNY DAY. MID CLOUDS DEVELOPING UNDER H700 WAA MON AFTN OVER MN AND NW WI...AND WILL APPROACH THE FAR WRN CWA LATE IN THE AFTN. COOL NRLY FLOW OFF LK SUPERIOR WILL KEEP MIXING DOWN NEAR THE LK SHORE AND KEEP HIGHS IN THE 30S. FARTHER INLAND AWAY FROM THE LK INFLUENCE...MIXING TOWARDS H850 TEMPS OF -4C WEST AND -9C EAST WILL PRODUCE HIGHS IN THE LOW-MID 40S...ESPECIALLY ALONG THE WI BORDER. AS FOR DEWPOINTS...MODEL MIXED LAYER DEWPOINT VALUES ARE IN THE LOW SINGLE DIGITS ABOVE ZERO OVER THE E HALF OF THE LAND CWA. THIS HAS BEEN CONSISTENT OVER THE LAST SEVERAL RUNS...SO HAVE ADJUSTED GOING VALUES DOWN A TOUCH AWAY FROM THE MOISTENING AFFECTS OF LK SUPERIOR. THIS LEADS TO RH VALUES FALLING INTO THE UPPER 20S...WITH A FEW MID-LOWER 20S OVER THE ERN CWA. WITH WINDS MAINLY 10KTS OR LESS AND ALONG WITH THE COOLER TEMPS...EXPECT FIRE WX CONCERNS TO BE LIMITED. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 454 PM EDT SUN MAR 25 2012 MONDAY NIGHT AND TUE...THE GFS...ECMWF AND NAM HAVE BEEN CONSISTENT AND WERE IN REASONABLY GOOD AGREEMENT WITH THE SHORTWAVE LIFTING FROM THE PLAINS TO THE NRN GREAT LAKES. STRONG WAA AND 295K- 305K ISENTROPIC LIFT (NOSE OF 850-800MB WINDS 50-55KT) WILL SUPPORT A BAND OF PCPN THROUGH THE CWA LATE MONDAY NIGHT INTO TUESDAY MORNING. THE VERY STRONG WAA IN THE 850-700 MB LAYER PUSHING WARM NOSE TEMPS TO AROUND 5C SHOULD LEAD TO MOSTLY LIQUID PCPN. WITH INCREASING CLOUDS AND WAA OVER THE FAR WEST EXPECT THAT SFC TEMPS SHOULD REBOUND ENOUGH BY THE ONSET OF PCPN TO KEEP PCPN AS RAIN. HOWEVER...OVER INTERIOR WEST AND CENTRAL UPPER MICHIGAN TEMPS INTO THE UPPER 20S TO AROUND 30 MAY LINGER AS THE PCPN MOVES IN. EVAPORATIVE COOLING AT THE ONSET OF PCPN WILL ALSO DELAY LOW LEVEL WARMING. WITH RELATIVELY WARM GROUND TEMPERATURES AFTER THE LONG WARM SPELL...THERE IS ADDITIONAL UNCERTAINTY ON HOW MUCH ICE IF ANY WOULD ACCUMULATE. SO...MENTIONED BOTH RA/FZRA FOR MOST OF THE THE CWA AND HIGHLIGHTED THE HAZARD IN A PORTION OF THE SPS. INSTABILITY FOR TSRA LOOKS MARGINAL...BUT SOME ELEVATED CAPE INTO EDING INTO THE CWA SUPPORTS AT LEAST CONTINUED MENTION OF SLIGHT CHANCE FOR TSRA. TUE NIGHT INTO WED...AS THE DRY SLOT SPREADS ACROSS THE ARA LATE TUE INTO TUE EVENING...PCPN SHOULD DIMINISH TO AREAS OF DRIZZLE OR ISOLATED SHOWERS DURING THE AFTERNOON AND EVENING. AS THE MID LEVEL LOW MOVES OFF TO THE NORTHEAST OF LAKE SUPERIOR AND A TRAILING SHORTWAVE MOVES THROUGH UPPER MI SOME ADDITIONAL WRAP-AROUND LIGHT SHOWERS MAY BE POSSIBLE WED MORNNG. BY THE TIME THE COLDER AIR ARRIVES WED AFTERNOON...DRIER AIR WILL ALSO SPREAD INTO THE REGION. SO...ONLY LOW END POPS FOR SOME LIGHT LAKE ENHANCED PCPN. THU-SUN...HIGH PRES SHOULD BUILD INTO THE AREA THU WITH COOL DRY AND MOSTLY SUNNY CONDITIONS. MODELS CONTINUE TO SUGGEST POTENTIAL FOR ANOTHER SHRTWV AND PCPN CHANCES MOVING INTO THE AREA THU NIGHT INTO FRIDAY EVEN THOUGH CONFIDECNE IN DETAILS IS LOW. A BLOCKING RIDGE TO THE NORTH WITH A SFC HUDSON BAY HIGH EXTENDEDING INTO THE AREA WILL LIMIT PCPN CHANCES TO LOWER END POPS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 756 PM EDT SUN MAR 25 2012 PER SATELLITE IMAGERY...DRIER AIR FILTERING INTO THE UPPER LAKES IS ERODING STRATOCU/MVFR CIGS OVER PORTIONS OF UPPER MI/LAKE SUPERIOR. FCST TONIGHT WILL REVOLVE AROUND IMPACT OF DRIER AIR...OVERLAKE INSTABILITY UNDER CHILLY AIRMASS AND POTENTIAL FOR MOISTURE/CLOUDS NE OF LAKE SUPERIOR TO RETURN AS LOW-LEVEL WINDS VEER DURING THE NIGHT. KIWD APPEARS MOST STRAIGHTFORWARD AS VEERING WINDS BRING INCREASING OVERLAND TRAJECTORY. CONDITIONS SHOULD REMAIN VFR WITH ONLY SCT CLOUDS AROUND 2K FT AT TIMES DURING THE EVENING. AT KCMX... BACKEDGE OF STRATOCU IS ADVANCING SLOWLY S ON THE KEWEENAW...AND SHOULD REACH KCMX IN THE NEXT FEW HRS. WITH WIND DOWN THE SPINE OF THE KEWEENAW OVERNIGHT...EXPECT VFR CONDITIONS WITH CLOUDS REMAINING MOSTLY SCT. AT KSAW...IFR CONDITIONS WITH -SN SHOULD END IN THE NEXT HR OR SO PER RECENT RADAR/SAT TRENDS. OTHERWISE...KSAW IS MORE LIKELY TO SEE AN MVFR CIG PERSIST WITH FAVORABLE UPSLOPE FLOW OFF THE LAKE AND POTENTIAL FOR MOISTURE NE OF THE LAKE TO ADVECT INTO THE AREA. ON THE OTHER HAND...INCREASINGLY ANTICYCLONIC FLOW MAY COUNTERACT FACTORS FAVORING CLOUDS. FOR NOW...CARRIED MVFR CIGS THRU THE EVENING AND SCATTERED CLOUDS OUT OVERNIGHT. WILL MONITOR FOR TRENDS TOWARD A MORE PESSIMISTIC FCST. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 454 PM EDT SUN MAR 25 2012 HIGH PRESSURE RIDGE MOVING INTO LAKE SUPERIOR TONIGHT WILL GRADUALLY DIMINISH THE PRESSURE GRADIENT OVER LAKE SUPERIOR AND LEAD TO A GRADUAL DIMINISHING TREND IN THE VEERING WINDS TONIGHT INTO MONDAY MORNING. AS THE LOW SHIFTS E ON MONDAY...A LOW PRESSURE SYSTEM DEVELOPING IN THE NRN PLAINS WILL SHIFT EAST AND ACROSS THE UPPER GREAT LAKES TUESDAY NIGHT AND WEDNESDAY. THIS COULD PRODUCE A SOUTHERLY GALE FORCE GUSTS TO 35KTS ON TUESDAY OVER EASTERN LAKE SUPERIOR. HIGH PRESSURE RIDGE WILL THEN BUILD OVER THE UPPER GREAT LAKES WED NIGHT AND THURSDAY...KEEPING WINDS BELOW 25KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY AFTERNOON FOR LSZ266. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...JLB AVIATION...ROLFSON MARINE...SRF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
322 PM CDT SAT MAR 24 2012 .DISCUSSION... SEVERAL FEATURES OF INTEREST WILL IMPACT THE REGION OVER THE COMING WEEK... ALTHOUGH AT THIS POINT NO PARTICULARLY SIGNIFICANT WEATHER APPEARS LIKELY. IN THE BIG PICTURE... THE LARGE SCALE UPPER FLOW WILL BECOME LESS AMPLIFIED AND HENCE MORE PROGRESSIVE AND SLIGHTLY MORE SEASONABLE IN OUR NECK OF THE WOODS. THIS MEANS THAT INSTEAD OF SEEING TEMPERATURES OF 20-30 DEGREES ABOVE NORMAL... THEY MAY BE MORE ON THE ORDER OF 10-15 DEGREES ABOVE NORMAL FOR A GOOD PART OF THE UPCOMING WEEK. ONE MAJOR CONCERN COULD BE THE POTENTIAL FOR FREEZING TEMPERATURES IN THE UPCOMING WEEK... SINCE SOME OF THE CALENDAR-DEFICIENT PLANTS HAVE DECIDED IT/S ALREADY TIME TO START GROWING. IT DOESN/T APPEAR AS THOUGH ANY WIDESPREAD FREEZING TEMPERATURES WILL OCCUR THROUGH THE UPCOMING WEEK... BUT PORTIONS OF THE AREA COULD SEE READINGS DIP NEAR OR BELOW FREEZING ON A COUPLE OF MORNINGS. THE GFS AND ECMWF ARE IN DECENT AGREEMENT THROUGH MOST OF THE WEEK... SO GENERALLY FOLLOWED A BLEND OF THEIR GUIDANCE... INCREASINGLY BLENDING IT WITH THE PREVIOUS FORECAST IN THE LATER PERIODS. VISIBILE IMAGERY SHOWS THIS MORNING/S LOW CLOUDS AND FOG HAVE FINALLY BURNED OFF OVER MOST OF THE AREA. TEMPERATURES ARE RESPONDING QUICKLY TO THE SUNSHINE... WITH READINGS CLIMBING THROUGH THE 60S TO AROUND 70. SHOULD CONTINUE TO SEE READINGS WORK UPWARD THE NEXT COUPLE OF HOURS... THEN THINGS WILL COOL OFF BOTH IN RESPONSE TO DARKNESS AND THE COLD FRONT MARCHING SOUTHEAST THROUGH THE AREA. THE FRONT CURRENTLY STRETCHES FROM NEAR INTERNATIONAL FALLS SOUTHWEST INTO EASTERN SOUTH DAKOTA. TEMPERATURES DROP OFF BEHIND THE FRONT... WITH A BIG DROP IN DEWPOINTS NOTED AS WELL. A FEW SHRA COULD DEVELOP IN NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN AS THE FRONT MOVES THROUGH THIS AFTERNOON AND EVENING... BUT AT THIS POINT IT LOOKS LIKE ANY OF THAT ACTIVITY SHOULD STAY NORTH OF OUR AREA. THE HRRR AND LOCAL 4KM WRF-ARW DO MANAGE TO PRODUCE SOME LIGHT SHRA INTO THE NORTHEAST PART OF OUR AREA... BUT AT THIS POINT WOULD RATHER SEE MORE GOING ON IN THE REAL WORLD TO INCLUDE A MENTION. AS MENTIONED... THE FRONT WILL SLIDE THROUGH TONIGHT... WITH RIDGING AND COOLER/DRIER AIR ARRIVING FOR OVERNIGHT THROUGH THE DAY ON SUNDAY. BUT... GIVEN THE MORE PROGRESSIVE FLOW... THIS CHANGE WILL BE SHORT-LIVED... WITH RETURN FLOW SETTING UP QUICKLY SUNDAY NIGHT. ISENTROPIC LIFT SUNDAY NIGHT INTO MONDAY IS IMPRESSIVE AS THE ELEVATED WARM FRONT LIFTS BACK NORTHEAST ACROSS THE AREA. IN ADDITION TO THE ISENTROPIC LIFT... FAIRLY SUBSTANTIAL LOW-MID LEVEL FRONTOGENESIS IS PROGGED FROM LATE SUNDAY NIGHT THROUGH THE DAY ON MONDAY AS THE BOUNDARY SLOWLY LIFTS NORTHEAST ACROSS THE AREA. A LOOK AT ELEVATED INSTABILITY... PER 850-500MB DIFFERENTIAL THETA-E VALUES... SHOWS SOME POTENTIAL FOR THUNDER CREEPING IN FROM WEST TO EAST LATE SUNDAY NIGHT INTO MONDAY NIGHT... WITH A CHANCE FOR SOME THUNDER ACROSS THE ENTIRE AREA BY LATER MONDAY NIGHT AS THE WARM SECTOR FULLY ESTABLISHES ITSELF OVER SOUTHERN MINNESOTA INTO WEST CENTRAL WISCONSIN. EXPECT AN INITIAL ARC OF PCPN ASSOCIATED WITH ELEVATED WARM ADVECTION TO LIFT INTO THE AREA LATE SUNDAY NIGHT INTO MONDAY MORNING... THEN A SECONDARY DEVELOPMENT OF PCPN BEHIND THAT OWING TO INCREASING ISENTROPIC LIFT ALONG WITH FRONTOGENESIS AND THE ARRIVAL OF ELEVATED INSTABILTY. IN ADDITION... SOME POTENT STORMS MAY DEVELOP TO OUR WEST MONDAY AFTERNOON INTO MONDAY EVENING... AND WHAT IS LEFT OF THOSE COULD WORK INTO THE AREA MONDAY NIGHT. LOW PRESSURE IS EXPECTED TO LIFT NORTHEAST INTO NORTHWEST MINNESOTA BY TUESDAY AFTERNOON... WORKING TO DRAG A COLD FRONT EAST THROUGH OUR AREA SOMEWHAT EARLY IN THE DAY. THE FRONT LOOKS TO GET ACROSS MOST OF THE MINNESOTA CWFA BY 18Z... AND THROUGH THE WISCONSIN PORTION OF THE AREA BY MID AFTERNOON. ALTHOUGH DEEP LAYER SHEAR SHOULD STILL BE QUITE STRONG ON TUESDAY... LOW LEVEL SHEAR DOES NOT LOOK TO BE AS IMPRESSIVE AS IT DID YESTERDAY... MAINLY DUE TO THE EARLIER PROGGED ARRIVAL OF THE FRONT. THE EARLIER FROPA WOULD ALSO LIMIT INSTABILITY INTO THE AREA... WHICH IS A NEGATIVE TOWARD THE SEVERE WEATHER POSSIBILITIES. SO... AT THIS POINT... THE OVERALL SEVERE WEATHER CHANCES FROM MONDAY NIGHT THROUGH TUESDAY DO NOT APPEAR PARTICULARLY HIGH ACROSS THE AREA. BUT... IT IS STILL A FEW DAYS AWAY... SO ANY CHANGES IN THE TIMING AND POSITION OF FEATURES COULD STILL CHANGE THINGS A BIT... SO IT IS WORTH KEEPING AN EYE ON THE SITUATION. STRONG WESTERLY WINDS WILL USHER IN DRIER AIR BEHIND THE FRONT LATE TUESDAY AFTERNOON INTO TUESDAY NIGHT... WITH 850MB TEMPERATURES OF BELOW ZERO ACTUALLY MAKING IT INTO THE AREA FOR A TIME ON WEDNESDAY INTO WEDNESDAY NIGHT. HOWEVER... THIS CHANGE WILL BE SHORTLIVED ONCE AGAIN... WITH RETURN FLOW AND WARMER AIR WORKING BACK INTO THE REGION BY LATER THURSDAY AND INTO FRIDAY. CHANCES FOR SHOWERS AND A FEW THUNDERSTORMS WILL ACCOMPANY THE RETURN OF WARMER TEMPERATURES THURSDAY INTO FRIDAY WITH PERHAPS SOME SHOWER CHANCES LINGERING INTO SATURDAY AS A SHORTWAVE MOVES BY TO OUR NORTH. && .AVIATION... /18Z TAF ISSUANCE/ /ISSUED 1246 PM CDT SAT MAR 24 2012/ CONTINUED IMPROVEMENT THIS AFTERNOON WITH CEILINGS BECOMING VFR FROM KSTC AND KMSP ON EASTWARD DURING THE MID TO LATE AFTERNOON HOURS. HOLES ARE DEVELOPING QUICKLY IN THE VISIBLE IMAGERY BETWEEN KMSP AND KDLH. KAXN AND KRWF ARE IN THE CLEAR BUT THE CONCERN FOR THESE TWO SITES...ESPECIALLY KAXN IS THE EXTENSIVE STRATUS BEHIND THE COLD FRONT OVER PORTIONS OF ND/SD. HAVE TIMED SOME BKN010 INTO KAXN THIS EVENING AS WELL AS KSTC DURING THE LATE EVENING. BOTH THE NAM AND GFS LOW LEVEL RH FIELDS WOULD SUPPORT A BAND OF LOW MVFR CEILINGS. IN FACT...IF THIS DOES OCCUR...THE CEILINGS WILL LIKELY RIDE ALL THE WAY THROUGH THE TWIN CITIES DURING THE LATE NIGHT HOURS AND ACROSS WEST CENTRAL WI EARLY SUNDAY MORNING. CONFIDENCE IS NOT HIGH AND ONLY SCT CONDITIONS USED AT THIS POINT. LIGHT WINDS THIS AFTERNOON BECOMING NORTHWEST WITH FROPA WITH SPEEDS OF 8-10 KNOTS A FEW HOURS AFTER THE FRONT GOES THROUGH. KMSP...IMPROVEMENT TO A VFR CEILING OR PERHAPS JUST SCT CONDITIONS STILL EXPECTED BY 21Z. WINDS THIS AFTERNOON WILL BE LIGHT AND FROM THE NORTHWEST. A DRY COLD FRONT WILL MOVE ACROSS THE AIRFIELD AROUND 03Z TONIGHT. WINDS WILL BECOME MORE NORTHERLY (330-350) WITH SPEEDS UP TO 10 KNOTS FOR THE OVERNIGHT HOURS. ONE CONCERN TONIGHT IS THE POSSIBILITY OF BKN-OVC010-015 DURING THE LATE NIGHT HOURS. THIS WOULD PRIMARILY BE AFTER 06Z AND LAST UNTIL NEAR 12Z. CONFIDENCE IS NOT HIGH ON OCCURRENCE WITH SCT CONDITIONS INDICATED FOR NOW. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ .../RAH
AREA FORECAST DISCUSSION
NWS DULUTH MN
1242 PM CDT SAT MAR 24 2012 .AVIATION...18Z TAFS IFR CONDITIONS COVERED MUCH OF THE NORTHLAND...BUT SATELLITE AND OBSERVATIONS BOTH REVEAL RISING AND THINNING CEILINGS. VFR CONDITIONS WILL DEVELOP IN SPOTS FOR A FEW HOURS...THEN MVFR/HIGH IFR CEILINGS WILL MOVE BACK IN BEHIND A COLD FRONT. CEILINGS WILL LIFT AND SCATTER OUT LATER TONIGHT BEHIND THE COLD FRONT. THE FRONT MAY BRING A FEW SHOWERS AHEAD OF IT AND SOME GUSTY WINDS UPON PASSAGE. SUNDAY WILL FEATURE VFR CONDITIONS. && .PREV DISCUSSION... /ISSUED 1153 AM CDT SAT MAR 24 2012/ UPDATE...DENSE FOG HAS LESSENED CONSIDERABLY ACROSS THE REGION AS OF LATE MORNING. LATEST RUC13 SHOWS MID LVL FLOW IS INCREASING AND ASSOCIATED SFC FRONT HAS PASSED THROUGH A KBDE/KFGN TO KGWR LINE. TEMPS IN 30S/40S BEHIND FRONT ACROSS NE NDAK. 88D HS BEEN SHOWING CONVECTIVE APPEARING ECHOES QUICKLY PASSING ACROSS NWRN CWA AHEAD OF FRONT. MAINLY MID LVL AT THIS POINT. ZFP/PFM PRODUCTS UPDATED. PREV DISCUSSION... /ISSUED 946 AM CDT SAT MAR 24 2012/ UPDATE...EXTENDED DFA THRU 18Z OVER WRN CWA AND 21Z FOR ERN ZONES. ALSO ADDED IRON COUNTY. WEDGE OF HIGH PRESSURE STILL LODGED ACROSS LAKE SUPERIOR...RIDGING SOUTHWEST TOWARD KAIT. VISIBILITIES HAVE BEEN AROUND 1/4SM-1/2SM. MSAS SHOWS SFC LOW HAS DEVELOPED WITHIN INVERTED TROUGH OVER SWRN CORNER OF ONT. TRAILING COLD FRONT THROUGH KGFK INTO NCTRL SD. LATEST NWP SHOWS POTENTIAL FOR PRE-FRONTAL THETAE AXIS TO INITIATE CONVECTION ONCE BDRY LYR MIXING/WARMING DEVELOPS LATER TODAY. OZ SPC WRF SHOWS THIN LINE OF RW DEVELOPING AFTER 21Z OVER NWRN CWA AND MOVING SE INTO WISC THIS EVENING. MAY NEED TO ADD LOW POPS OVER NWRN WISC IN LATER FCST IF PRECIP DOES MATERIALIZE. FCST MAX TEMPS VERY TRICKY. AS LONG AS STRATUS/FOG LAYER RESIDES OVERHEAD DIURNAL CURVE IS RESTRICTED. HOWEVER EXISTING FCST IS BASED ON EVENTUAL WARM ADVECTION INCREASE JUST AHEAD OF APPROACHING FRONT. MOST IMPORTANTLY...ENOUGH DECREASE IN CLOUD LAYER WILL NEED TO OCCUR TO ALLOW ABOUT A 3HR WINDOW OF PARTIAL SUNSHINE. PREV DISCUSSION... /ISSUED 700 AM CDT SAT MAR 24 2012/ AVIATION.../12Z TAF ISSUANCE/ LIFR TO IFR CONDITIONS ARE WIDESPREAD ACROSS THE AREA THIS EARLY MORNING. AS THE MORNING WEARS ON...CONDITIONS WILL LARGELY IMPROVE TO MVFR OR EVEN VFR...AS DRIER LOW LEVEL AIR SPREADS IN. A COLD FRONT WILL MOVE ACROSS THE NORTHLAND LATER TODAY OR DURING THE EVENING. IN THE VICINITY OF THE FRONT...SOME ADDITIONAL MVFR CONDITIONS WILL BE POSSIBLE. PREV DISCUSSION... /ISSUED 415 AM CDT SAT MAR 24 2012/ SHORT TERM...LATEST SURFACE ANALYSIS SHOWS A TROUGH OF LOW PRESSURE OVER THE DAKOTAS...WITH A COLD FRONT EXTENDING SOUTH OF THE TROUGH ACROSS WRN NEBRASKA AND ERN COLORADO. THERE IS ALSO A WARM FRONT SHOWING UP ON THE SURFACE ANALYSIS...GENERALLY FROM ERN SODAK ACROSS IOWA AND CNTL ILLINOIS. NORTH OF THE WARM FRONT ACROSS MUCH OF THE UPPER MIDWEST...INCLUDING THE NORTHLAND...THE LOW- LEVELS HAVE BECOME SATURATED...RESULTING IN WIDESPREAD FOG. ACROSS OUR CWA...THE FOG HAS BECOME DENSE IN MANY AREAS...AND ESPECIALLY AROUND LAKE SUPERIOR. AS A RESULT...WE HAVE EXPANDED THE DENSE FOG ADVISORY TO INCLUDE THE BRAINERD LAKES REGION...IRON RANGE...ARROWHEAD AND SOUTHSHORE. THE FOG SHOULD GRADUALLY DISSIPATE AFTER SUNRISE...AND LIFT BY MIDDAY. THE AFOREMENTIONED WARM FRONT IS THEN PROGGED TO LIFT NEWD ACROSS THE UPPER MIDWEST TODAY...BRIEFLY BRINGING THE WARM SECTOR ACROSS THE REGION...RESULTING IN HIGHS IN THE 60S FOR MOST LOCATIONS THIS AFTERNOON. THE COLD FRONT WILL TRACK EWD ACROSS THE CWA THIS AFTERNOON AND EVENING...BRINGING COOLER AND MUCH DRIER AIR TO THE NORTHLAND LATER TONIGHT INTO SUNDAY. THE COLD FRONT MAY ALSO TRIGGER A FEW SHOWERS AND STORMS ACROSS OUR MN ZONES THIS AFTERNOON AS IT MOVES THROUGH. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY. UPPER LEVEL RIDGING WILL MOVE INTO THE REGION SUNDAY NIGHT AND MONDAY...AS STRONG LOW LEVEL WAA INITIATES DURING THE FIRST PART OF THE WORK WEEK. A 50 KNOT LLJ WILL BE IN PLACE BY MONDAY EVENING ACROSS THE UPPER MIDWEST...AS A SURFACE LOW PRESSURE SYSTEM MOVES INTO THE DAKOTAS. HEIGHTS WILL DROP CONSIDERABLY AS A CLOSED LOW DEVELOPS OVER MINNESOTA BY LATE TUESDAY. THE ECMWF APPEARS TO OFFER A COMPROMISE SOLUTION BETWEEN THE FURTHER NORTH GFS AND THE STRONGER AND FURTHER WEST GEM SOLUTION. BASED ON THE ECMWF SOLUTION...SHOWERS AND THUNDERSTORMS WILL BE LIKELY FOR THE EARLY TO MID PART OF THE WEEK. H5 HEIGHTS WILL BEGIN TO BUILD ONCE AGAIN BY THURSDAY...AHEAD OF THE NEXT SYSTEM TO MOVE INTO THE REGION THURSDAY AND FRIDAY. FOR THE LATE WEEK SYSTEM...IT APPEARS THERE WILL BE AN AMPLE SUPPLY OF MOISTURE FROM THE GULF OF MEXICO...RESULTING IN MORE SHOWERS AND THUNDERSTORMS FOR THE LAST PART OF THE WEEK. TEMPERATURES ARE STILL EXPECTED TO BE ABOVE NORMAL THROUGHOUT THE ENTIRE EXTENDED TIME PERIOD...ALTHOUGH COOLER THAN WHAT IT HAS BEEN AWAY FROM THE LAKE RECENTLY. && .POINT TEMPS/POPS... DLH 34 50 29 40 / 10 10 10 10 INL 26 45 25 45 / 10 10 0 20 BRD 33 53 35 47 / 10 10 20 40 HYR 38 56 31 50 / 10 10 10 20 ASX 38 50 30 44 / 10 10 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121- 140>148. && $$ SHORT TERM...CANNON LONG TERM....DAP AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1153 AM CDT SAT MAR 24 2012 .UPDATE...DENSE FOG HAS LESSENED CONSIDERABLY ACROSS THE REGION AS OF LATE MORNING. LATEST RUC13 SHOWS MID LVL FLOW IS INCREASING AND ASSOCIATED SFC FRONT HAS PASSED THROUGH A KBDE/KFGN TO KGWR LINE. TEMPS IN 30S/40S BEHIND FRONT ACROSS NE NDAK. 88D HS BEEN SHOWING CONVECTIVE APPEARING ECHOES QUICKLY PASSING ACROSS NWRN CWA AHEAD OF FRONT. MAINLY MID LVL AT THIS POINT. ZFP/PFM PRODUCTS UPDATED. && .PREV DISCUSSION... /ISSUED 946 AM CDT SAT MAR 24 2012/ UPDATE...EXTENDED DFA THRU 18Z OVER WRN CWA AND 21Z FOR ERN ZONES. ALSO ADDED IRON COUNTY. WEDGE OF HIGH PRESSURE STILL LODGED ACROSS LAKE SUPERIOR...RIDGING SOUTHWEST TOWARD KAIT. VISIBILITIES HAVE BEEN AROUND 1/4SM-1/2SM. MSAS SHOWS SFC LOW HAS DEVELOPED WITHIN INVERTED TROUGH OVER SWRN CORNER OF ONT. TRAILING COLD FRONT THROUGH KGFK INTO NCTRL SD. LATEST NWP SHOWS POTENTIAL FOR PRE-FRONTAL THETAE AXIS TO INITIATE CONVECTION ONCE BDRY LYR MIXING/WARMING DEVELOPS LATER TODAY. OZ SPC WRF SHOWS THIN LINE OF RW DEVELOPING AFTER 21Z OVER NWRN CWA AND MOVING SE INTO WISC THIS EVENING. MAY NEED TO ADD LOW POPS OVER NWRN WISC IN LATER FCST IF PRECIP DOES MATERIALIZE. FCST MAX TEMPS VERY TRICKY. AS LONG AS STRATUS/FOG LAYER RESIDES OVERHEAD DIURNAL CURVE IS RESTRICTED. HOWEVER EXISTING FCST IS BASED ON EVENTUAL WARM ADVECTION INCREASE JUST AHEAD OF APPROACHING FRONT. MOST IMPORTANTLY...ENOUGH DECREASE IN CLOUD LAYER WILL NEED TO OCCUR TO ALLOW ABOUT A 3HR WINDOW OF PARTIAL SUNSHINE. PREV DISCUSSION... /ISSUED 700 AM CDT SAT MAR 24 2012/ AVIATION.../12Z TAF ISSUANCE/ LIFR TO IFR CONDITIONS ARE WIDESPREAD ACROSS THE AREA THIS EARLY MORNING. AS THE MORNING WEARS ON...CONDITIONS WILL LARGELY IMPROVE TO MVFR OR EVEN VFR...AS DRIER LOW LEVEL AIR SPREADS IN. A COLD FRONT WILL MOVE ACROSS THE NORTHLAND LATER TODAY OR DURING THE EVENING. IN THE VICINITY OF THE FRONT...SOME ADDITIONAL MVFR CONDITIONS WILL BE POSSIBLE. PREV DISCUSSION... /ISSUED 415 AM CDT SAT MAR 24 2012/ SHORT TERM...LATEST SURFACE ANALYSIS SHOWS A TROUGH OF LOW PRESSURE OVER THE DAKOTAS...WITH A COLD FRONT EXTENDING SOUTH OF THE TROUGH ACROSS WRN NEBRASKA AND ERN COLORADO. THERE IS ALSO A WARM FRONT SHOWING UP ON THE SURFACE ANALYSIS...GENERALLY FROM ERN SODAK ACROSS IOWA AND CNTL ILLINOIS. NORTH OF THE WARM FRONT ACROSS MUCH OF THE UPPER MIDWEST...INCLUDING THE NORTHLAND...THE LOW- LEVELS HAVE BECOME SATURATED...RESULTING IN WIDESPREAD FOG. ACROSS OUR CWA...THE FOG HAS BECOME DENSE IN MANY AREAS...AND ESPECIALLY AROUND LAKE SUPERIOR. AS A RESULT...WE HAVE EXPANDED THE DENSE FOG ADVISORY TO INCLUDE THE BRAINERD LAKES REGION...IRON RANGE...ARROWHEAD AND SOUTHSHORE. THE FOG SHOULD GRADUALLY DISSIPATE AFTER SUNRISE...AND LIFT BY MIDDAY. THE AFOREMENTIONED WARM FRONT IS THEN PROGGED TO LIFT NEWD ACROSS THE UPPER MIDWEST TODAY...BRIEFLY BRINGING THE WARM SECTOR ACROSS THE REGION...RESULTING IN HIGHS IN THE 60S FOR MOST LOCATIONS THIS AFTERNOON. THE COLD FRONT WILL TRACK EWD ACROSS THE CWA THIS AFTERNOON AND EVENING...BRINGING COOLER AND MUCH DRIER AIR TO THE NORTHLAND LATER TONIGHT INTO SUNDAY. THE COLD FRONT MAY ALSO TRIGGER A FEW SHOWERS AND STORMS ACROSS OUR MN ZONES THIS AFTERNOON AS IT MOVES THROUGH. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY. UPPER LEVEL RIDGING WILL MOVE INTO THE REGION SUNDAY NIGHT AND MONDAY...AS STRONG LOW LEVEL WAA INITIATES DURING THE FIRST PART OF THE WORK WEEK. A 50 KNOT LLJ WILL BE IN PLACE BY MONDAY EVENING ACROSS THE UPPER MIDWEST...AS A SURFACE LOW PRESSURE SYSTEM MOVES INTO THE DAKOTAS. HEIGHTS WILL DROP CONSIDERABLY AS A CLOSED LOW DEVELOPS OVER MINNESOTA BY LATE TUESDAY. THE ECMWF APPEARS TO OFFER A COMPROMISE SOLUTION BETWEEN THE FURTHER NORTH GFS AND THE STRONGER AND FURTHER WEST GEM SOLUTION. BASED ON THE ECMWF SOLUTION...SHOWERS AND THUNDERSTORMS WILL BE LIKELY FOR THE EARLY TO MID PART OF THE WEEK. H5 HEIGHTS WILL BEGIN TO BUILD ONCE AGAIN BY THURSDAY...AHEAD OF THE NEXT SYSTEM TO MOVE INTO THE REGION THURSDAY AND FRIDAY. FOR THE LATE WEEK SYSTEM...IT APPEARS THERE WILL BE AN AMPLE SUPPLY OF MOISTURE FROM THE GULF OF MEXICO...RESULTING IN MORE SHOWERS AND THUNDERSTORMS FOR THE LAST PART OF THE WEEK. TEMPERATURES ARE STILL EXPECTED TO BE ABOVE NORMAL THROUGHOUT THE ENTIRE EXTENDED TIME PERIOD...ALTHOUGH COOLER THAN WHAT IT HAS BEEN AWAY FROM THE LAKE RECENTLY. AVIATION.../06Z TAF ISSUANCE/ ALONG THE LAKE SUPERIOR SHORE AND AROUND THE WESTERN NOSE INCLUDING DLH...DYT...SUW...COQ...AND TWM...LIFR IN DENSE FOG WILL LIFT TO MVFR IN CLOUDS ABOUT MID MORNING SATURDAY. ELSEWHERE...IFR OR LOW-END VFR IN CLOUDS AND PATCHY FOG WILL LIFT TO MVFR IN CLOUDS EARLY SATURDAY MORNING. CONDITIONS WILL THEN LIFT TO VFR IN SCATTERED CLOUDS LATE SATURDAY. && .POINT TEMPS/POPS... DLH 61 34 50 29 / 10 10 10 10 INL 56 26 45 25 / 30 10 10 0 BRD 63 33 53 35 / 10 10 10 20 HYR 62 38 56 31 / 10 10 10 10 ASX 56 38 50 30 / 10 10 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121- 140>148. && $$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1005 PM CDT SUN MAR 25 2012 .UPDATE...MOISTURE AXIS IS ALIGNING ACROSS OUR WESTERN CWA ATTM AND HRRR MODEL SUGGESTS POTENTIAL FOR SOME REDUCED VSBYS IN FOG ALONG MOISTURE AXIS AND HAVE ADDED IN SOME PATCHY FOG TOWARD MORNING. ALSO...INCREASING LLVL JET OVER MOISTURE AXIS AND DECENT AREA OF THETA E ADVECTION ALIGNS ACROSS OUR EASTERN CWA OVERNIGHT. CANNOT COMPLETELY RULE OUT A STORM OR TWO IN THIS AREA AND INCLUDED SOME LOW POPS FOR TONIGHT. && .PREV DISCUSSION... /ISSUED 606 PM CDT SUN MAR 25 2012/ AVIATION...00Z TAF. MID TO HIGH VFR LEVEL CLOUDS WILL CROSS THE TERMINAL TONIGHT THROUGH MONDAY. GUSTY SOUTHEASTERLY WINDS EARLY THIS EVENING WILL DECREASE DURING THE NIGHT BUT WILL INCREASE AGAIN ON MONDAY AS THE SURFACE GRADIENT TIGHTENS IN RESPONSE TO A DEEPENING LOW PRESSURE SYSTEM OVER THE ROCKIES. SOUTH SOUTHEASTERLY WINDS WILL INCREASE TO 20 TO 25KTS AND GUST OVER 30KTS DURING THE AFTERNOON. PREV DISCUSSION... /ISSUED 448 PM CDT SUN MAR 25 2012/ SHORT TERM...TONIGHT AND TOMORROW. PRIMARY FORECAST CONCERNS LIE WITH PRECIPITATION CHANCES AND WINDS. UPPER AIR PROFILER AND SATELLITE DATA SHOW THE CENTRAL PLAINS REMAINING UNDER THE INFLUENCE OF A RIDGE AXIS...SANDWICHED BETWEEN LOW PRESSURE SYSTEMS LOCATED OVER THE CAROLINAS AND JUST OFF THE SOCAL COAST. LOW LEVEL STRATUS WHICH WAS PUSHING SOUTH THIS MORNING MADE IT IN TO JUST ABOUT I-80...BEFORE THE LOW LEVEL WINDS STARTED TRANSITIONING FROM THE NORTH TO MORE TO THE EAST. TOOK A LITTLE BIT...BUT THE SFC RIDGE AXIS FINALLY SHIFTED OFF TO THE EAST OF THE CWA...AND WITH LOW PRESSURE OVER THE ROCKIES...WINDS ACROSS THE ENTIRE CWA EVENTUALLY SWITCHED OVER TO THE S/SE. BETWEEN THIS MORNINGS CLOUD COVER NOT ERODING UNTIL LATE MORNING AND ANOTHER BATCH OF LOW/MID LEVEL CLOUDS AFFECTING THE NWRN CORNER OF THE CWA...TEMPS THIS AFTERNOON HAVE ONLY REACHED INTO THE MID 60S TO LOW 70S...VS THE MID/UPPER 70S ELSEWHERE ACROSS THE CWA. LOOKING TO THIS EVENING AND OVERNIGHT...KEPT THE FORECAST DRY...BUT WILL STATE THAT CONFIDENCE IS NOT HIGH...ESP IN THE NORTHEAST/EASTERN QUARTER OR SO OF THE CWA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE DEVELOPMENT OF A 40-50KT SWRLY LLJ TONIGHT...WHICH NOSES INTO...AND EVENTUALLY THROUGH THE CWA BY 12Z MONDAY. ACCOMPANYING THE NOSE OF THE LLJ IS A SURGE OF INCREASED WARM AIR/THETAE ADVECTION...MAINLY AFFECTING THE NERN HALF OF THE CWA BETWEEN 06-12Z. REALLY DEBATED THROWING SOME SMALL POPS IN...BUT ANOTHER THING THAT THE MODELS ARE IN GOOD AGREEMENT ON IS THE PRESENCE OF CAPPING...SHOWING 700MB TEMPS RANGING ANYWHERE FROM 5-9 DEG C DEPENDING ON THE MODEL. THE CAPPING IS A BIT WEAKER ALONG THAT NE/ERN FRINGE OF THE CWA...AND WHILE THE GFS DEVELOPS PRECIP THERE ISNT MUCH SUPPORT FROM OTHER MODELS WITH THERE BEING ENOUGH FORCING TO BREAK THROUGH THAT CAP. WITH CONTINUED S/SERN FLOW OVERNIGHT /WITH SPEEDS HIGHER THAN LAST FEW NIGHTS/...EXPECTING LOW TEMPS TO BE WARMER...AND FORECAST LOWS SIT IN THE LOWER/MID 50S. AS WE GET INTO TOMORROW...THE MAIN FOCUS TURNS TO WINDS...THOUGH PRECIPITATION CHANCES REMAIN FOR LATE AFTERNOON. THE UPPER LEVEL PATTERN SHOWS THE MAIN RIDGE AXIS SLIDING OFF TO THE EAST AS A DISTURBANCE MAKES ITS WAY TROUGH THE ROCKIES...LEAVING THE CWA WITH SWRLY FLOW. AS THIS DISTURBANCE MOVES CLOSER...EXPECTING TO SEE DEEPENING SFC LOW PRESSURE OVER THE NORTHERN ROCKIES WITH A TROUGH AXIS EXTENDING SOUTH THROUGH THE HIGH PLAINS. THIS WILL RESULT IN A TIGHTENING PRESSURE GRADIENT ACROSS THE CENTRAL PLAINS...AND INCREASING SRLY WINDS THROUGH THE DAY. WHILE MIXING POTENTIAL LOOKS TO ONLY REACH UPWARDS OF 850MB...THERE ARE ALSO INCREASED WINDS TO TAP INTO. DECIDED TO GO WITH A WIND ADV ACROSS THE CENTRAL AND WRN PORTIONS OF THE CWA...ALONG AND WEST OF HWY 281 DURING THE AFTERNOON HOURS. THE ERN FRINGE IS MORE ON THE MARGINAL SIDE...BUT WAS COMFORTABLE INCLUDING IT. EXPECTING TO SEE A BUMP UP IN TEMP...WITH HIGHS IN THE LOWER/MID 80S. AT THIS POINT COULD CREEP CLOSE TO RECORD HIGHS /MAINLY IN HASTINGS AND KEARNEY/...BUT SHOULD REMAIN BELOW. RECORDS ARE 86 AT BOTH HASTINGS AND KEARNEY IN 1989...AND 90 IN GRAND ISLAND IN 1907. THE POTENTIAL FOR THUNDERSTORMS BEGINS TO INCREASE LATE IN THE AFTERNOON...MAINLY ACROSS THE FAR WRN FRINGE OF THE CWA...AND DID KEEP THE LOW POPS IN. WHILE WE DO HAVE INCREASING INSTABILITY/LAPSE RATES AND THE DISTURBANCE IS SHIFTING CLOSER...MODELS REMAIN IN GOOD AGREEMENT KEEPING THINGS PRETTY CAPPED THROUGH THE AFTERNOON...SO WAS NOT GOING TO INCREASE POPS. LONG TERM...MONDAY EVENING THROUGH NEXT SUNDAY. VARIOUS CONCERNS DURING THIS 6-DAY TIME FRAME INCLUDE POSSIBLE...BUT CERTAINLY NOT LIKELY THUNDERSTORM CHANCES MONDAY NIGHT...POTENTIAL FIRE WEATHER ISSUES ON TUESDAY AFTERNOON...AND THEN ADDITIONAL...FAIRLY LOW CONFIDENCE THUNDERSTORM CHANCES IN THE THURSDAY-FRIDAY NIGHT TIME FRAME. WILL DISCUSS THESE ELEMENTS FIRST...AND CONCLUDE WITH SOME DISCUSSION ABOUT TEMPERATURES... STARTING OFF RIGHT AWAY MONDAY EVENING...THE MILLION DOLLAR QUESTION IS WHETHER ANY POTENTIALLY STRONG TO SEVERE STORMS WILL AFFECT THE CWA...AS A COMPACT BUT VIGOROUS NEGATIVELY TILTED MID LEVEL SHORTWAVE SWINGS FROM THE WY/NEB PANHANDLE AREA AT 00Z...TO ND BY 12Z TUESDAY MORNING. DUE TO THE TRACK OF THE WAVE...CLEARLY THE STRONGEST FORCING WILL REMAIN NORTH OF THE CWA. IN ADDITION...12Z NAM PLAN VIEW CINH FIELDS AND FORECAST SOUNDINGS INDICATE CONSIDERABLE CAPPING TO NEAR-SURFACE BASED PARCELS...AS EVIDENCED BY 700MB TEMPS INITIALLY IN THE 6-8C RANGE. ALTHOUGH THE 12Z GFS INSISTS ON STORMS AFFECTING AT LEAST THE WESTERN 1/3 OR SO OF THE CWA...THE LAST TWO NAM RUNS AND ALSO 12Z ECMWF SKIRT CONVECTION JUST NORTH OF THE CWA IN THE EVENING...AND THEN RE-FOCUSING EASTWARD ALONG AN AXIS FROM IA TO EASTERN KS AFTER MIDNIGHT ALONG THE ADVANCING 850MB FRONT AND WITHIN THE LOW LEVEL JET AXIS. ALTHOUGH SEVERE PARAMETERS ARE NOT GREAT...NAM/GFS GENERALLY AGREE ON ELEVATED CAPE IN THE 500-1000 J/KG RANGE DURING THE NIGHT...AND 0-6KM DEEP LAYER SHEAR AROUND 40KT. CERTAINLY THIS COULD SUPPORT STRONG TO MARGINALLY SEVERE STORMS...WITH HAIL TO QUARTER SIZE REALLY THE MAIN THREAT...BUT GIVEN LOW CONFIDENCE IN COVERAGE WILL KEEP POPS AT ONLY 20 PERCENT FOR NOW ACROSS THE NORTHWEST 2/3 OF THE CWA BEFORE MIDNIGHT...AND THE SOUTHEAST 1/3 LATER IN THE NIGHT. TUESDAY THROUGH WEDNESDAY NIGHT...KEPT IT DRY CWA-WIDE...AS QUASI-ZONAL FLOW TAKES HOLD OF THE CENTRAL PLAINS...DRIER LOW LEVEL AIR INVADES...AND THE PRIMARY SURFACE FRONT AND RESULTANT INSTABILITY AXIS HANGS UP ACROSS THE SOUTHERN 2/3 OF KANSAS. THAT BEING SAID...WILL HAVE TO KEEP AN EYE ON MAINLY NORTH CENTRAL KS ZONES IN THE TUES NIGHT AND WED NIGHT TIME FRAMES IN CASE ANY CONVECTION BRUSHES INTO THE CWA NEAR MODEST LOW LEVEL JETS FOCUSES FARTHER SOUTH. THE MAIN ISSUE WILL BE FIRE WEATHER CONCERNS FOR TUESDAY AFTERNOON BEHIND THE IMPRESSIVE DRYLINE PASSAGE. WITH DEWPOINTS DECREASING/MIXING DOWN INTO THE 20S TO LOW 30S AT BEST TUESDAY AFTERNOON...HAVE RELATIVE HUMIDITIES FALLING DOWN INTO THE 15-20 PERCENT RANGE MOST AREAS. ALTHOUGH THIS IS FORECAST INTO RED FLAG WARNING CRITERIA...THE STRONGEST SUSTAINED WIND SPEEDS AROUND 20 MPH OR HIGHER SHOULD FOCUS ACROSS THE NORTHERN 1/2 OF THE CWA IN CLOSER PROXIMITY TO THE DEPARTING SURFACE LOW...WITH LIGHTER WINDS PREVALENT NEAR AND SOUTH OF THE STATE LINE. DESPITE THE RECENT GREEN-UP...THE OFFICIAL VEGETATIVE FUEL STATUS IS STILL FAVORABLE FOR FIRE GROWTH...AND THUS WE COULD EASILY BE HEADING TOWARD A RED FLAG WARNING ESPECIALLY FOR MUCH OF NEB ZONES. ALTHOUGH CONFIDENCE IN THE DETAILS GETS PROGRESSIVELY LOWER WITH TIME...VARIOUS THUNDERSTORM CHANCES IN THE 20-50 PERCENT RANGE ENTER THE CWA IN THE THURSDAY THROUGH FRIDAY NIGHT TIME FRAME...AS AT LEAST TWO FAIRLY LOW AMPLITUDE SHORTWAVES PROGRESS THROUGH THE QUASI-ZONAL FLOW...AND INTERACT WITH AT LEAST MODEST INCREASING INSTABILITY AS A SURFACE RIDGE AXIS MOVES EAST AND INSTABILITY RETURNS. AS IT CURRENTLY STANDS...THE OVERALL BEST RISK FOR MEASURABLE RAINFALL IS THURSDAY NIGHT MAINLY IN THE EAST...BUT THESE CHANCES COULD EASILY MIGRATE AROUND OR CHANGE...AS THE ECMWF AND GFS START TO GET VERY OUT OF PHASE WITH TIMING OF WAVES. WITH DEEP LAYER SHEAR CURRENTLY LOOKING MODEST...CERTAINLY NO OBVIOUS SEVERE WEATHER THREATS IN THIS TIME FRAME...BUT ISOLATED SEVERE NOT OUT OF THE QUESTION. FOR SATURDAY- SUNDAY...LEFT DRY AS MODELS GENERALLY AGREE ON SHORTWAVE RIDGING. CONCLUDING WITH A BRIEF DISCUSSION ON TEMPS FROM TUESDAY THROUGH SUNDAY...KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...WITH LOW-MID 70S ALL DAYS...BUT COULD FORESEE READINGS BY NEXT SUNDAY GETTING BOOSTED CLOSER TO 80 IF A RIDGE BUILDS AS ADVERTISED. REGARDING LOW TEMPS...DID MAKE SOME ADJUSTMENTS...GENERALLY NUDGING MANY AREAS DOWN 2-5 DEGREES FOR BOTH MON NIGHT AND TUES NIGHT AS DRIER AIR INVADES AND WINDS LIGHTEN. IN FACT...NOW HAVE MID-UPPER 30S ACROSS MUCH OF THE NORTHWEST CWA ON TUESDAY NIGHT. THAT BEING SAID...STILL NO LEGITIMATE FREEZING TEMPS IN SIGHT THROUGH THE NEXT WEEK. && .GID WATCHES/WARNINGS/ADVISORIES... NE...WIND ADVISORY FROM 1 PM TO 7 PM CDT MONDAY FOR NEZ039-040-046- 047-060>062-072>075-082>085. KS...WIND ADVISORY FROM 1 PM TO 7 PM CDT MONDAY FOR KSZ005>007- 017>019. && $$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1224 AM CDT SAT MAR 24 2012 .AVIATION...06Z KGRI TAF. AS AN UPPER LEVEL RIDGE BUILDS INTO THE PLAINS THIS EVENING...WEATHER CONDITIONS WILL REMAIN FAIRLY CALM THROUGH THE TAF PERIOD. WINDS WILL REMAIN LIGHT OUT OF THE SOUTHWEST THROUGH THE DAY BECOMING LIGHT AND VARIABLE SATURDAY EVENING. A FEW HIGH CLOUDS WILL LIKELY STICK AROUND THIS EVENING BEFORE BECOMING MOSTLY CLEAR. && PREV DISCUSSION... /ISSUED 354 PM CDT FRI MAR 23 2012/ SHORT TERM...THROUGH SATURDAY AFTERNOON. NEEDLESS TO SAY...THE NEXT 24 HOURS CONTINUE THE RETURN TO INCREDIBLY NICE LATE MARCH WEATHER...WITH HIGH TEMPS ON SATURDAY FORECAST TO BE RIGHT AROUND CLIMATOLOGICAL NORMALS FOR LATE MAY/EARLY JUNE. STARTING OFF AT 20Z THIS AFTERNOON...A LIGHT AND SOMEWHAT VARIABLE WIND REGIME IS IN PLACE ACROSS THE CWA...THANKS TO A BROAD DIFFUSE RIDGE AXIS. THE COMBINATION OF MODEST BOUNDARY LAYER MOISTURE...ALONG WITH SOME COOLER MID LEVEL AIR ON THE BACK SIDE OF THE DEPARTING CLOSED LOW OVER SOUTH CENTRAL MISSOURI...HAS RESULTED IN A LEGITIMATE SCATTERED FAIR WEATHER CUMULUS FIELD ESPECIALLY ACROSS THE EASTERN HALF OF THE CWA. ALTHOUGH THIS SCATTERED TO LOCALLY BROKEN DECK WAS A BIT MORE CLOUD COVER THAN EARLIER EXPECTED...TEMPS HAVE HAD STILL HAD NO PROBLEMS MAKING IT INTO AT LEAST THE MID-UPPER 60S AT THIS HOUR...WITH SOME PLACES POSSIBLY TOUCHING 70 BY DAYS END. AS MENTIONED...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA CLEARLY REVEAL THE DEPARTING CLOSED LOW AS THE MAIN MID/UPPER FEATURE OF INTEREST...WITH SHORTWAVE RIDGING NOW BUILDING ALONG AN AXIS FROM THE SOUTHERN ROCKIES TO NORTHERN PLAINS...AND THE NEXT LOW PRESSURE SYSTEM OF INTEREST STILL WELL OFF THE PACIFIC COAST. FOR LATE THIS AFTERNOON...HAVE KEPT THE FORECAST DRY...ALTHOUGH THE HRRR CONTINUES TO INSIST THAT A FEW SPRINKLES COULD FLIRT WITH FAR SOUTHEAST EDGES OF THE CWA. BASED ON LATEST VIS SATELLITE TRENDS...ANY SLIGHTLY ENHANCED CUMULUS GROWTH POTENTIALLY CONDUCIVE TO SPRINKLES/LIGHT RAIN SHOULD REMAIN JUST EAST OF THESE COUNTIES. THIS EVENING/TONIGHT...BOUNDARY LAYER CUMULUS DEVELOPMENT SHOULD QUICKLY FADE AWAY...RESULTING IN ESSENTIALLY CLEAR SKIES AS SHORTWAVE RIDGING CONTINUES TO NOSE OVERHEAD IN THE WAKE OF THE DEPARTING LOW...WHICH WILL BE NEAR THE IL/IN/KY BORDER AREA BY 12Z. BREEZES WILL REMAIN LIGHT OVERNIGHT...BUT THE DIRECTION WILL PREVAIL FROM THE WEST/SOUTHWEST. ONLY POTENTIAL ISSUE IS FOG DEVELOPMENT OVERNIGHT. VARIOUS MODEL BOUNDARY LAYER RELATIVE HUMIDITY PROGS...ALONG WITH MET/MAV VISIBILITY GUIDANCE...SUGGEST THAT THIS LIGHT WESTERLY LOW LEVEL FLOW WILL NOT BE VERY CONDUCIVE TO FOG DEVELOPMENT. THAT BEING SAID...AT LEAST LIGHT FOG HAS DEVELOPED HERE AND THERE ACROSS THE CWA THE PAST FEW NIGHTS LARGELY DUE TO MOIST GROUND IN THE WAKE OF RECENT RAINFALL. GIVEN THAT PATCHY FOG WORDING HAS ALREADY BEEN IN THE FORECAST FOR OVER 24 HOURS NOW IN SOME AREAS...WILL LET IT RIDE...BUT WOULD BE VERY SURPRISED TO SEE MORE THAN PATCHY LIGHT VISIBILITY RESTRICTIONS. FOR LOW TEMPS...KEPT SIMILAR TO PREVIOUS FORECAST IN EASTERN ZONES...BUT BUMPED DOWNWARD A FEW DEGREES IN THE WEST...RESULTING IN A RANGE FROM MID-UPPER 30S WEST...LOW 40S CENTRAL...MID 40S SOUTHEAST. BASED ON WHAT HAPPENED THIS MORNING WITH LOWS TUMBLING INTO THE LOW 30S WEST...WOULD NOT BE SURPRISED IF TONIGHTS LOWS END UP A BIT LOWER THAN FORECAST. HOWEVER...THE LIGHT WESTERLY BREEZES SHOULD HELP HOLD THINGS UP A BIT VERSUS LAST NIGHT. SATURDAY...THE MID/UPPER PATTERN REMAINS QUITE TRANQUIL...AS THE HEART OF THE 700-500MB RIDGE BUILDS OVER THE PLAINS...WELL TO THE EAST OF THE DEEP TROUGH AXIS OFF THE PACIFIC COAST...AND THE PRIMARY 300MB JET AXIS SNAKING FROM NORTHERN CA THEN EASTWARD ACROSS SOUTHERN CANADA. AS A SURFACE HIGH PRESSURE SYSTEM WORKS INTO SOUTHERN CANADA INTO THE DAKOTAS...A VERY WEAK COLD FRONT WILL PUSH SOUTHWARD TOWARD/INTO THE NORTHWEST CWA DURING THE AFTERNOON. OTHERWISE...LIGHT SOUTHWEST BREEZES WILL PREVAIL ACROSS MOST OF THE CWA FOR THE MAJORITY OF THE DAY. WITH FORECAST SOUNDINGS A BIT DRIER IN THE BOUNDARY LAYER COMPARED TO TODAY...NOT ANTICIPATING MUCH CUMULUS DEVELOPMENT...AND IN FACT VERY LITTLE CLOUD COVER. TEMP WISE...GIVEN THE WIDESPREAD SUN AND 850MB TEMPS CLIMBING WELL INTO THE 14-17C RANGE...A NOTABLE JUMP IN AFTERNOON HIGHS IN LIKELY. DIDN/T GET TOO CARRIED AWAY...BUT NUDGED UP PREVIOUS FORECAST TOWARD HIGHER END OF MET/MAV GUIDANCE CONSENSUS...WITH MOST OF THE CWA INTO THE 78-80 RANGE. LONG TERM...SATURDAY NIGHT THROUGH FRIDAY. WE KICK THINGS OFF SATURDAY NIGHT WITH A PROMINENT UPPER RIDGE OVER THE PLAINS AND A HIGHLY AMPLIFIED TROUGH ON ENTERING THE WEST COAST OF THE UNITED STATES. WEATHER SHOULD REMAIN DRY INTO SUNDAY THANKS TO BEING UNDER THE INFLUENCE OF NOT ONLY THE UPPER LEVEL RIDGE BUT A SURFACE RIDGE AS WELL. THERE WILL BE A SURFACE TROUGH DEVELOPING IN THE LEE OF THE ROCKIES BY SUNDAY NIGHT WITH A HEALTHY FAIRLY STRONG LOW-LEVEL JET INCREASING OVER PARTS OF WESTERN AND CENTRAL KANSAS...WITH THE NOSE OF THE JET MAKING ITS WAY INTO SOUTHERN AND CENTRAL PARTS OF THE CWA BY LATE SUNDAY NIGHT...WITH THE NAM A BIT STRONGER HERE...INDICATING A 50 KT JET...AS OPPOSED TO NEAR 40 KTS FOR THE GFS AND ECMWF. AT THIS POINT...THERE DOES NOT APPEAR TO BE ENOUGH MOISTURE TO GET ANY CONVECTION GOING...BUT IF THERE WERE...STRONG TO SEVERE THUNDERSTORMS WOULD CERTAINLY NOT BE OUT OF THE QUESTION. CONFIDENCE IS NOT HIGH ENOUGH TO INTRODUCE CHANCES OF RAIN AT THIS POINT. A POTENT NEGATIVELY TILTED SHORTWAVE TROUGH WILL EJECT NORTHEAST OUT OF THE CENTRAL ROCKIES MONDAY NIGHT AND HAS BEEN PROJECTED TO DO SO FOR SOME TIME. THERE ARE SOME STRENGTH AND TIMING DIFFERENCES BETWEEN MEDIUM TO LONG RANGE MODELS...BUT THE GENERAL SCENARIO IS SIMILAR. THE ECMWF CONTINUES TO PROJECT A STRONGER WAVE THAT EJECTS INTO THE PLAINS SOONER THAN THE GFS SOLUTION. SURFACE PRESSURE GRADIENTS WILL INCREASE ALONG WITH INCREASED MIXING AND WE COULD BE GETTING CLOSE TO WIND ADVISORY WITH HEALTHY WIND FROM THE SOUTH...ESPECIALLY IN THE WESTERN CWA. MODELS GENERALLY PRODUCE THE NOSE OF THE LOW-LEVEL JET WELL NORTH OF THE CWA...ALONG WITH THE BEST MID TO UPPER LEVEL FORCING TO THE NORTH AS WELL. AT THE SURFACE...BY MONDAY EVENING...THE DRY LINE SHOULD STILL BE WELL TO THE WEST OF THE CWA...WHILE A WARM FRONT IS EXPECTED TO HAVE PASSED TO THE NORTHEAST OF THE CWA BY THEN. SEVERE PARAMETERS SUGGEST POSSIBLE SEVERE WEATHER NEAR THESE BOUNDARIES...BUT WE MAY WIGGLE OUT OF MOST OF THE SEVERE WEATHER BY BEING BETWEEN THESE BOUNDARIES WHILE SEVERE WEATHER INITIATES TOWARD EVENING...GIVEN THAT SOUNDINGS SUGGEST WE WILL BE TOO CAPPED TO PRODUCED MUCH OF ANYTHING IN THE REGION UNTIL LATE AFTERNOON AND QUITE LIKELY IN THE EVENING...AND FOR THIS REASON...I HAVE ALL BUT PULLED CHANCES OF PRECIPITATION FROM MONDAY AFTERNOON...SAVE PERHAPS THE FAR NORTHEASTERN CORNER OF THE CWA IF THE WARM FRONT DOES NOT GET OUT OF THE CWA FAST ENOUGH...AND HAVE LIMITED THAT SMALL AREA TO LATE AFTERNOON...DESPITE THE FACT THAT THE LATEST ECMWF PAINTS SOME QPF OVER THE NORTHWEST. THIS DOES NOT LOOK PROBABLE AS IT APPEARS THAT THE WARM FRONT SHOULD CLEAR THE CWA BEFORE CONVECTION BEGINS AND THERE IS NO OTHER FOCUS FOR CONVECTION IN THE AFTERNOON TO REALLY GET THINGS GOING FROM WHAT IT LOOKS LIKE FOR NOW. THIS LOOKS LIKE A SCENARIO WHERE WE MAY WIND UP GETTING SOME NOCTURNAL HIGH PLAINS CONVECTION AS THE THETA E AXIS WILL MOVE FROM WEST TO EAST ACROSS THE CWA BETWEEN 03Z AND 08Z TUESDAY (MONDAY EVENING)...BUT THIS MAY BE MORE OF A WEAKER LEFTOVER EVENT...GIVING US ELEVATED STRONGER/HEAVY RAINER STORMS...BUT PERHAPS NO LONGER SEVERE. I AM NOT CONFIDENT ENOUGH TO PULL SEVERE POTENTIAL OUT OF THE HWO...AS TIMING DIFFERENCES COULD MAKE A HUGE DIFFERENCE...AND BEING SO FAR OUT IN THE FORECAST...IT WOULD BE PRUDENT TO KEEP SEVERE POTENTIAL MENTIONED IN THE HWO. AFTER THE WAVE PASSES MONDAY NIGHT...THERE WILL BE LITTLE MORE CHANCE OF PRECIPITATION FOR A COUPLE OF DAYS WITH RIDGING TAKING PLACE. TUESDAY COULD BE GETTING CLOSE TO RED FLAG POTENTIAL IN THE FAR WESTERN CWA WITH RELATIVE HUMIDITY POSSIBLY GETTING NEAR 20 PERCENT AND WEST WINDS APPROACHING SUSTAINED 20 MPH. THE ECMWF INDICATES A SMALL PERTURBATION RIDING THE RIDGE BY WEDNESDAY NIGHT ALONG OUR SOUTHERN FRINGE WITH PERHAPS THE AID OF SOME CONVERGENCE AT 850 MB...BUT EVEN WITH QPF ADVERTISED BY THE ECMWF...PROBABILITY OF PRECIPITATION FOR RUSSEL AND CONCORDIA ARE AROUND 20 PERCENT...AND LOWER THAN THIS IN OUR CWA TO THE NORTH. FOR THE REST OF THE EXTENDED...I LEFT LOW CHANCES OF PRECIPITATION AS FLOW COULD CONTAIN POTENTIAL SMALL WAVES OF ENERGY...ALTHOUGH TEMPERATURES WILL REMAIN WELL ABOVE NORMAL. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
339 PM EDT SAT MAR 24 2012 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL GRADUALLY MOVE OFFSHORE LATE SUNDAY AND SUNDAY NIGHT. A SECONDARY COLD FRONT WILL CROSS THE AREA ON MONDAY FOLLOWED BY STRONG COOL HIGH PRESSURE THROUGH MID WEEK. && .NEAR TERM /TONIGHT/... AS OF 330 PM SATURDAY...SHOWERS AND TSTMS HAVE BECOME WIDESPREAD ACROSS EASTERN NORTH CAROLINA OVER THE PAST HOUR OR TWO. A REPORT OF DIME-SIZED HAIL WAS RECEIVED FROM JONES COUNTY. THE STORMS CROSSING THE AREA WILL HAVE THE POTENTIAL TO PRODUCE GUSTY WINDS...SMALL HAIL AND FREQUENT LIGHTNING OVER THE NEXT 2 TO 3 HOURS. ADDITIONAL CONVECTION ASSOCIATED WITH THE ACTUAL COLD FRONT WILL BE MORE SCATTERED PER LATEST 4 KM WRF AND RUC MODELS...BUT COULD BE STRONG TO SEVERE LATER IN THE EVENING GIVEN BETTER INSTABILITY OVER THE CENTRAL PORTION OF THE STATE WORKING ITS WAY EASTWARD. HAVE LIKELY POPS TAPERING TO HIGH CHANCE AFTER 23Z. POPS GRADUALLY DROP OVERNIGHT WITH THE SEVERE THREAT LESSENING AFTER ABOUT 03Z OR SO. MINIMUM TEMPERATURES TONIGHT SHOULD BE IN THE 57 TO 62 DEGREE RANGE. && .SHORT TERM /SUNDAY/... AS OF 335 PM SAT...AS UPPER LOW MOVES NEAR OR JUST SOUTH OF THE AREA DURING THE DAY ON SUNDAY WITH SURFACE LOW JUST TO OUR NORTH...THERE WILL SUFFICIENTLY STRONG LAPSE RATES AND INSTABILITY TO PRODUCE SCATTERED SHOWERS AND TSTMS. DUE TO THE COLD AIR ALOFT...SOME OF THE STRONGER STORMS COULD BECOME HAIL PRODUCERS. COVERAGE OF PRECIPITATION IS TOUGH FOR TOMORROW BUT BEST GUESS IN TAPERING THE POPS FROM SLIGHT CHANCE FAR SOUTH TO HIGH CHANCE TO LOW LIKELY FAR NORTH...IN CLOSER PROXIMITY TO THE SURFACE LOW. TEMPERATURES SHOULD RANGE FROM ABOUT 73 TO 77 DEGREES. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... AS OF 315 PM SAT...UPR LOW WILL MOVE THROUGH E NC SUN NIGHT...WITH DEFORMATION AXIS PIVOTING THROUGH DURING THE EVENING. SUFFICIENT DEEP LAYER MOISTURE WILL EXIST WITH SCT SHOWER CHANCES AS ENOUGH LIFT WILL ACCOMPANY THE UPR LOW PASSAGE. MUCH DRIER AIR INFILTRATES THE REGION ON NW FLOW. DESPITE THE FRONTAL PASSAGE... TEMPS WILL BE QUITE WARM MON AFTERNOON COMPLIMENTS OF DOWNSLOPING FLOW OFF APPALACHIANS. THE STEEP LAPSE RATES WILL LEND TO GUSTY WINDS FOR MON UNDER SUNNY SKIES. HIGH PRES WILL NOSE INTO THE AREA MON NIGHT WITH WINDS BECOMING LIGHT. THERE MAY BE SOME SCT FROST FOR AREAS AWAY FROM THE COAST WITH MINS DROPPING INTO THE MID 30S. ATTM NOT EXPECTING FREEZING TEMPS THOUGH WITH TD`S NEAR 30...COMPLETE DECOUPLING WOULD ALLOW FOR SOME FAVORED LOCATIONS INLAND TO DIP DOWN NEAR FREEZING. REINFORCING SURGE OF NORTHERLY FLOW OCCURS TUE WITH LOW LEVEL THICKNESSES FALLING A BIT...AND MAX TEMPS WILL GENERALLY BE IN THE LOW TO MID 60S. ANOTHER COOL NIGHT EXPECTED TUE NIGHT AS SFC HIGH PRES WILL BE CENTERED OVERHEAD. RETURN FLOW COMMENCES ON WED WITH WSW FLOW ALLOWING FOR MAX TEMPS TO REBOUND INTO THE MID 70S. A SHORTWAVE TROUGH WILL SWING THROUGH NORTH OF THE AREA WED EVENING BRINGING A SMALL CHANCE OF TRW FOR NORTHERN PORTIONS OF THE CWA...THOUGH THIS FRONTAL PASSAGE WILL BE MOISTURE STARVED SO NOT EXPECTING MUCH IN THE WAY OF QPF. THUR AND FRI WILL FEATURE SEASONABLY MILD TEMPERATURES AND DRY CONDITIONS WITH ZONAL FLOW ALOFT AND SFC HIGH PRES IN THE AREA. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH SUNDAY/ AS OF 1235 PM SATURDAY...CEILINGS ARE VFR AT PGV AND OAJ AND HAVE IMPROVED TO MVFR AT EWN AND ISO AS MIXING INCREASES. SCATTERED SHOWERS AND TSTMS ARE POSSIBLE THRU THE AFTERNOON HOURS INTO THIS EVENING WITH PERIODS OF LOWER CEILINGS AND VSBYS LIKELY. FOR TONIGHT AND SUNDAY...AFTER SOME LIKELY DRY-SLOTTING EARLY IN THE EVENING...MOST ALL GUIDANCE INDICATES IFR AND POSSIBLE LIFR CEILINGS AS LOW LEVEL MOISTURE LINGERS THROUGH LATE TONIGHT AND SUNDAY MORNING...BEFORE CONDITIONS IMPROVE MONDAY. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 315PM SAT...COULD BE SOME MVFR CIGS SUN NIGHT AS UPR LOW SWINGS THROUGH THE AREA WITH SCT SHOWERS. MOISTURE WILL ERODE QUICKLY ON MON AS DRY AIR FILTERS IN WITH MOSTLY SUNNY SKIES. WINDS WILL BECOME NW AND BECOME A BIT GUSTY ON MON. DRY CONDITIONS EXPECTED THROUGH MIDWEEK AS HIGH PRES WILL BE IN THE AREA. && .MARINE... SHORT TERM /THROUGH SUNDAY/ AS OF 335 PM SATURDAY...HAVE ADJUSTED START TIME OF SCA TO SUNDAY MORNING AS WINDS/SEAS WILL BE A BIT SLOWER TO RAMP UP PER LATEST MODELS. WINDS STILL BELOW 15 KNOTS AND SEAS GENERALLY 2 TO 3 FEET CURRENTLY. GUSTY SOUTHWEST WINDS AND SOUTHWEST WAVE ENERGY DUE TO THE COMBINATION OF APPROACHING COLD FRONT AND HIGH PARKED NEAR BERMUDA WILL LEAD TO SOME 6 FOOT SEAS...ESPECIALLY OVER THE OUTER WATERS THROUGH THE DAY SUNDAY. LONG TERM SUNDAY THROUGH WEDNESDAY/... AS OF 3 PM SAT...IT APPEARS THERE WILL BE A BRIEF WINDOW OF SEAS AND WINDS TO BE BELOW SCA CONDITIONS FOR SUN EVENING. BY 12Z MON...WINDS AND SEAS WILL INCREASE DRASTICALLY AS COLD FRONT MOVES THROUGH THE WATERS WITH STRONG CAA OCCURRING. SCA WILL BE LIKELY FOR THE WATERS AND SOUNDS BY MON MORNING. A REINFORCING SHOT OF NORTHERLY WINDS MON NIGHT INTO TUE WILL KEEP SCA CONDITIONS FOR MOST OF THE WATERS. WINDS AND SEAS WILL BE HIGHEST FOR THE NORTHERN/CENTRAL WATERS WITH SEAS OF 7 TO 9 FEET EXPECTED HERE. WINDS AND SEAS SHOULD DIMINISH BELOW SCA BY TUE EVENING. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 8 PM EDT SUNDAY FOR AMZ152-154-156-158. && $$ SYNOPSIS...CTC NEAR TERM...CTC SHORT TERM...CTC LONG TERM...TL AVIATION...CTC/TL MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1002 PM CDT SUN MAR 25 2012 .DISCUSSION...MAIN UPDATE THIS EVENING WAS TO LOWER TEMPERATURES EVEN MORE ACROSS THE FAR NORTHEAST CWA WHERE A DRY EASTERLY FLOW IS SLOWING THE DEVELOPMENT OF CLOUDS. TEMPERATURES ALREADY IN THE UPPER 20S T LOWER 30S IN THIS REGION. WILL LOWER TEMPERATURES INTO THE MID 20S HERE. IN THE FAR SOUTHWEST...LOWERED TEMPERATURES JUST A BIT AS WELL. LOWER CLOUDS SHOULD CONTINUE TO LIFT INTO THE AREA BUT TEMPERATURES ALREADY AT FORECAST LOWS. LATEST NAM/RUC INDICATE PRECIPITATION HOLDING OFF UNTIL TUESDAY MORNING ACROSS WESTERN AND CENTRAL NORTH DAKOTA. LATEST HRRR DOES SHOW SOME LIGHT SHOWER ACTIVITY LIFTING NORTH ACROSS THE AREA LATE TONIGHT. FOR NOW...LEFT THE FORECAST AS IS WITH A SLIGHT CHANCE IN THE SOUTHWEST AFTER MIDNIGHT. WE DID REMOVE THE MENTION OF SHOWERS IN THE FAR SOUTHEAST CWA AS THAT ACTIVITY HAS MOVED OUT. && .AVIATION...LOW PRESSURE WILL CONTINUE TO DEVELOP OVER THE NORTHERN HIGH PLAINS TONIGHT...WITH A SURFACE LOW DEPICTED OVER SOUTHEAST MONTANA BY MONDAY EVENING. EAST TO SOUTHEAST FLOW WILL CONTINUE THROUGH THE FORECAST PERIOD. THIS WILL BRING INCREASING LOW LEVEL MOISTURE INTO THE AREA. DICKINSON HAS DROPPED TO MVFR CEILINGS. BROUGHT MVFR CEILINGS INTO REMAINING AERODROMES BETWEEN 06 AND 12 UTC...MVFR-IFR CONDITIONS WILL CONTINUE THROUGH MONDAY. ALSO BROUGHT A MENTION OF THUNDER INTO SOUTH CENTRAL NORTH DAKOTA AFTER MIDNIGHT. && .BIS WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY EVENING FOR NDZ017>020-031>034-040>045. HIGH WIND WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR NDZ035>037-046>048-050-051. && $$ SHORT TERM...TWH AVIATION...
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
125 AM EDT SAT MAR 24 2012 .SYNOPSIS... AN UPPER LEVEL LOW OVER MISSOURI WILL MOVE SLOWLY EASTWARD TO WESTERN KENTUCKY BY SATURDAY AFTERNOON. THIS LOW WILL WEAKEN AND MOVE OFF THE MIDDLE ATLANTIC COAST BY SUNDAY EVENING. HIGH PRESSURE WILL BUILD SOUTHEAST INTO THE AREA BY LATE MONDAY THEN SHIFT OFF TO THE EAST BY LATE TUESDAY. ANOTHER AREA OF LOW PRESSURE WILL MOVE INTO THE CENTRAL GREAT LAKES FOR THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... DID A QUICK UPDATE TO FRESHEN UP THE WORDING AND KEEP THE POPS CHANCE OVER NORTHWEST OHIO. WATCHING CONVECTION OVER EASTERN INDIANA. THE HRRR MODELS IS FORECASTING ALL THAT CONVECTION WILL DECREASE BY AROUND 08Z....WILL CONTINUE TO MONITOR THIS. ADJUSTED MINS UP BASED ON THE CLOUDS. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/... THE UPPER LOW WILL BE OVER KY BY SATURDAY AFTERNOON WITH SOME COOLER AIR EXPECTED ALOFT. THIS WILL AT LEAST ALLOW FOR SOME SHOWERS AND THUNDERSTORMS TO PERSIST THROUGH AT LEAST THE MORNING. THE COOLER AIR ALOFT MAY ALLOW FOR ADDITIONAL DEVELOPMENT DURING THE AFTERNOON. THE LOW STILL MAY PROVIDE A FEW SHOWERS/THUNDER INTO SUNDAY BUT SHOULD BE SCATTERED IN NATURE. BY SUNDAY NIGHT HIGH PRESSURE WILL RIDGE INTO THE AREA HELPING TO CLEAR SKIES AND COOLER TEMPERATURES INTO MONDAY. PATCHY FROST MAY BE POSSIBLE AS EARLY AS MONDAY MORNING...ESPECIALLY ACROSS INLAND NW PA. LIGHT WINDS AND CLEAR SKIES MONDAY NIGHT MAY ALLOW FOR AREAS OF FROST AND MAYBE EVEN A HARD FREEZE BY TUESDAY MORNING. THIS POTENTIAL HAS BEEN MENTIONED IN THE HWO. HIGHS SATURDAY WILL REMAIN IN THE 60S BUT IT WILL BE COOLER ON SUNDAY AS ANOTHER FRONT PASSES. HIGHS SUNDAY WILL GENERALLY BE NEAR AROUND 60 DEGREES. IN THE WAKE OF THE FRONT ON MONDAY HIGHS WILL REMAIN IN THE 50S...MAYBE UPPER 40S ACROSS NW PA. && .LONG TERM /TUESDAY THROUGH FRIDAY/... STRONG SFC HIGH PRES WILL KEEP CONDITIONS DRY TUE...BUT PLENTY OF SUNSHINE SHOULD ALLOW TEMPS TO ABOVE NORMAL (LOWER 50S) DESPITE A COLD START. A WARM FRONT AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM WILL PUSH THROUGH THE REGION LATE TUESDAY RESULTING IN LOWS IN THE 40S OVERNIGHT. RAIN AND STORMS WILL BE POSSIBLE WED WITH THE LOW PASSAGE BUT WILL BROAD BRUSH THE TIMING GIVEN POST WARM FRONT SCT SHOWERS...COLD FROPA...AND UPPER LVL LOW TIMING ISSUES. BY THU THE LOW WILL BE EAST OF THE AREA AND NE FLOW WILL SET UP ACROSS THE LAKE. THIS WILL KEEP CLOUDS AND LIGHT RAIN POSSIBLE WITH TEMPS IN THE LOWER 50S. GENERALLY STAYED WITH A MODEL CONSENSUS FOR MUCH OF THE PERIOD RELYING MORE ON RAW DATA THAN GUIDANCE. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... WIDESPREAD SHRA AND TSRA WILL AFFECT THE AREA THROUGH THE TAF PERIOD. CONDITIONS SHOULD LOWER TO MOSTLY MVFR WITH POCKETS OF IFR THE REST OF TONIGHT AS LOW LEVEL MOISTURE INCREASES AND THE AIRMASS COOLS. DAYTIME HEATING SAT SHOULD LIFT CONDITIONS TO MOSTLY VFR BY LATE MORNING AND HOLD THAT WAY INTO EARLY SAT EVENING THEN DAYTIME COOLING WILL AGAIN ALLOW CONDITIONS TO LOWER BACK TO MVFR BY THE END OF THE TAF PERIOD. THE COOLING AND HEATING OF THE AIRMASS SHOULD ALSO LEAD TO SOME DECREASE IN OVERALL CONVECTIVE ACTIVITY BY SAT MORNING THEN SHRA/TSRA SHOULD AGAIN BECOME MORE NUMEROUS SAT AFTERNOON AS NEW ACTIVITY DEVELOPS FROM DAYTIME HEATING. .OUTLOOK...NON VFR POSSIBLE LATE SATURDAY NIGHT AND SUNDAY. && .MARINE... WINDS ARE EXPECTED TO DIMINISH OVERNIGHT OUT OF THE EAST AND BECOME VARIABLE BY SATURDAY MORNING. GENERALLY LIGHT AND VARIABLE FLOW WILL CONTINUE THROUGH THE REST OF THE WEEKEND. WINDS DO INCREASE CONSIDERABLY SUNDAY NIGHT INTO MONDAY FROM THE NORTH AND WE WILL LIKELY NEED TO HOIST SMALL CRAFT ADVISORIES DURING THAT PERIOD. I ANTICIPATE SMALL CRAFT ADVISORIES WILL NEED TO REMAIN IN EFFECT THROUGH TUESDAY. LARGE AREA OF SHOWERS AND THUNDERSTORMS CONTINUE TO SLOWLY ADVANCE EAST TOWARD THE LAKE. IT WILL TAKE SOME TIME TO GET INTO THE REGION. ONCE THEY ARRIVE...THEY WILL SLOWLY DECREASE FROM WEST TO EAST SATURDAY NIGHT INTO SUNDAY. FAIR WEATHER WILL RETURN ACROSS THE ENTIRE LAKE SUNDAY NIGHT. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...MULLEN NEAR TERM...KIELTYKA SHORT TERM...MULLEN LONG TERM...JAMISON AVIATION...ADAMS MARINE...LOMBARDY
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1025 PM CDT SUN MAR 25 2012 .DISCUSSION.../ISSUED AT 910 PM CDT/ CURRENTLY GETTING A FEW SHOWERS AND THUNDERSTORMS ACROSS SOUTHWEST MINNESOTA. THIS SEEMS TO LINE UP PRETTY WELL WITH LOW LEVEL THETAE ADVECTION OFF THE RUC. HOWEVER RUC CURRENTLY ONLY ANALYZING LESS THAN 100 J/KG CAPE IN THAT AREA. WITH REPORTS OF PEA SIZE HAIL...THAT IS LIKELY UNDERDONE. FOLLOWED CLOSE TO THE RUC THETAE ADVECTION IN THE 900-800MB LAYER FOR PRECIP CHANCES TONIGHT...TRANSITIONING OVER TO THE NAM AFTER THAT. ANOTHER SURGE CURRENTLY ENTERING THE MISSOURI RIVER VALLEY...AND A FEW SHOWERS STARTING TO POP UP DOWN THERE. THIS AREA WILL SLOWLY TRANSITION NORTHEAST...WITH ONLY ISOLATED ACTIVITY EXPECTED. AS THIS REACHES SOUTHWEST MINNESOTA...WHERE CURRENT ACTIVITY IS ONGOING AND CAP IS WEAKEST...MAY SEE A BIT MORE SHOWER OR THUNDERSTORM COVERAGE...GENERALLY IN THE 6Z TO 12Z TIMEFRAME. THIS SAME REGION MAY SEE A REDEVELOPMENT OF ACTIVITY MONDAY AFTERNOON...AS ANOTHER DECENT AREA OF THETE ADVECTION MOVES ACROSS. MUCAPE WILL BE WEAK THROUGH THE DAY TOMORROW...THUS NOT EXPECTING ANY MORE THAN PEA SIZE HAIL WITH ANY STORMS THAT DO FORM. THE HIGHER INSTABILITY ALOFT...CLOSER TO 1-2K J/KG...WILL STAY WEST OF THE JAMES RIVER VALLEY THROUGH THE DAYLIGHT HOURS TOMORROW. BUT THAT REGION SHOULD BE UNDER THE INFLUENCE OF A STRONGER CAP...THUS THINK WE WILL PROBABLY NOT BE ABLE TO TAP INTO THAT CAPE. ONLY OTHER CHANGE WAS MINOR UPDATES TO THE HOURLY TEMP AND DEWPOINTS...TRENDED CLOSER TO THE HRRR...WHICH SEEMS TO HAVE A DECENT HANDLE ON THEM RIGHT NOW. /CHENARD .PREVIOUS DISCUSSION.../ISSUED AT 350 PM CDT/ FOR TONIGHT...EASTERLY SURFACE FETCH OF AIR WILL CONTINUE AND WILL INCREASE MODESTLY DURING THE OVERNIGHT AND LATE NIGHT HOURS. DECIDED TO ELIMINATE OUR SMALL POPS THROUGHOUT OUR WESTERN ZONES THIS EVENING. AT THIS TIME...CINS LOOK TOO HIGH TO SPARK EVEN A SHOWER IN THAT AREA AND STRATUS ALL DAY HAS NOT HELPED THE INSTABILITY FACTOR ANY. DID HANG ONTO A SLIGHT CHANCE POP LATE THIS EVENING ACROSS PARTS OF SW MN. COULD BE A FEW SPRINKLES IN THAT AREA WITH SOME CLOUD COVER BETWEEN 5 AND 10 THOUSAND FEET...BUT CERTAINLY NO BIG DEAL. AFTER MIDNIGHT...DECIDED TO GO WITH A SMALL POP IN OUR SOUTH CENTRAL SD ZONES WHERE SOME FAIRLY STRONG THETAE ADVECTION EXISTS...MAXIMIZED AROUND 800MB...PUSHING IT A BIT FURTHER EASTWARD LATE TONIGHT. COVERAGE APPEARS VERY ISOLATED. THE BIGGEST CHALLENGE TONIGHT IS TEMPERATURES...AS READINGS HAVE NOT RISEN MUCH WHERE CLOUD COVER HAS EXISTED ALL DAY. BUT WITH AN EASTERLY WIND WHICH WILL NOT GO DOWN AND SOME WARM AIR ADVECTION...TEMPERATURES MAY NOT FALL OFF ALL THAT MUCH IN OUR AREAS THAT DID NOT WARM UP. ON MONDAY...STRONG SHORT WAVE ENERGY MOVES INTO THE WESTERN PLAINS AS THE DAY PROGRESSES. ABOUT THE ONLY CHANCES WE HAVE OF ANY THUNDERSTORM ACTIVITY IN OUR FORECAST AREA WILL BE ALONG AND EAST OF THE JAMES RIVER VALLEY IN THE MORNING...ASSOCIATED WITH THE AFOREMENTIONED STRONG THETAE ADVECTION LIFTING TO THE NORTHEAST. LATE IN THE DAY...THERE MAY ALSO BE AN ISOLATED THUNDERSTORM IN SOUTH CENTRAL SD CLOSER TO THE WIND SHIFT. RIGHT NOW...SEVERE CHANCES LOOK EXTREMELY LIMITED THROUGH MONDAY WITH A LACK OF FOCUS MECHANISM TO REALLY HANG YOUR HAT ON. MUCH OF THE DYNAMICS OVERALL IS STAYING WEST OF OUR AREA. IT WILL BE QUITE WINDY ON MONDAY AS BOTH THE PRESSURE GRADIENT AND WINDS ALOFT INCREASE...WITH SE WINDS SOLIDLY IN THE 20 TO 35 MPH CATEGORY. AS THE SURFACE WARM FRONT LIFTS NORTHEASTWARD...HEATING SHOULD BE DRAMATIC IN OUR SW AND SOUTH CENTRAL ZONES SOUTH OF THE FRONTAL BOUNDARY. GIVEN THE 900 TO 850MB TEMPERATURES...IT LOOKS LIKE THE WARM MAV GUIDANCE ARE THE ONLY NUMBERS THAT RIGHT NOW LOOK THE CLOSEST FOR THIS FORECAST AREA... ESPECIALLY FOR OUR ZONES SOUTH OF THE FRONT. HAVE A STRONG 25 DEGREE THERMAL GRADIENT FOR HIGHS FROM SW TO NE IN OUR AREA. ON MONDAY NIGHT THE DEEPENING UPPER LEVEL LOW TRACKS FROM WYOMING TO NORTH DAKOTA THROUGH THE NIGHT...WITH THE SURFACE REFLECTION IN THE FORM OF A SURFACE BOUNDARY SWINGING ACROSS OUR AREA. SEVERE WEATHER NOW NOT LOOKING AS IMPRESSIVE WITH ELEVATED CAPE PRETTY WEAK OVER OUR CWA IN CONJUNCTION WITH INCREDIBLE SHEAR...AROUND 60 KTS...TEARING ANY STORMS APART. THINK THE BIGGER THREAT MIGHT BE A STRONG WIND GUST WITH THE FRONTAL SURGE...WITH STRONG WINDS ALOFT AND PRESSURE RISES OF 6 TO 7 MB JUST BEHIND THE FRONT. EXPECT THAT ANY CONVECTION THAT OCCURS WILL BE TIED TO LOW LEVEL CONVERGENCE AND THETA E ADVECTION OUT AHEAD OF THE BOUNDARY. LOW TEMPERATURES ON MONDAY NIGHT WILL BE MILD...IN THE LOWER TO UPPER 50S...WITH TEMPERATURES RISING FOR A WHILE IN THE NORTHEAST AS THE WARM FRONT LIFTS TO THE NORTH THROUGH THE EVENING. BY EARLY ON TUESDAY THE BOUNDARY WILL BE EXITING OUR AREA...TAKING ANY CONVECTION THAT FORMS WITH IT. IT WILL BE WINDY WITH STRONG LOW LEVEL COLD AIR ADVECTION...A TIGHT GRADIENT...AND PRESSURE RISES...THOUGH WINDS ALOFT WILL BE TAPERING DOWN DURING THE DAY WITH 850 MB WIND SPEEDS FALLING TO 25 TO 35 KTS BY EARLY AFTERNOON. MAY BE A POSSIBILITY OF A WIND ADVISORY AT SOME POINT. EVEN WITH COLD AIR ADVECTION...WITH MORE SUN ON TUESDAY HIGHS LOOK TO REACH THE MID 60S TO LOWER 70S. DEFINITELY STILL LOOKING LIKE AN ENHANCED FIRE DANGER ACROSS OUR SOUTH ON TUESDAY AFTERNOON WITH LOWER DEWPOINTS STREAMING IN BEHIND THE EXITING FRONTAL BOUNDARY...YIELDING AFTERNOON RELATIVE HUMIDITY VALUES OF AROUND 20 PERCENT THROUGH THE MISSOURI RIVER CORRIDOR. WHILE STILL PLENTY BREEZY OVER THAT AREA DURING THE AFTERNOON...HIGHER WINDS APPEAR TO BE FOUND TO THE NORTH...AND WITH THE EXACT AMOUNT OF RAINFALL THROUGH THAT AREA STILL SOMEWHAT UNCERTAIN AT THIS TIME POTENTIAL FIRE HEADLINES WILL BE EVOLVING OVER THE NEXT 24 HOURS OR SO. WITH THE SYSTEM CONTINUING TO PULL AWAY THE GRADIENT WILL RELAX BY TUESDAY NIGHT...WITH WINDS DYING AND TEMPERATURES FALLING INTO THE UPPER 30S TO MID 40S ACROSS THE AREA. HIGH PRESSURE SETTLES INTO THE REGION ON WEDNESDAY WITH THE BRUNT OF THE COOLER AIRMASS FALLING INTO THE MIDWEST BEHIND THE EXITING LOW OVER THE GREAT LAKES. WITH THAT...HIGHS WILL ONLY REACH THE UPPER 50S OVER PORTIONS OF OUR SOUTHWESTERN MINNESOTA ZONES...TO THE UPPER 60S THROUGH THE MISSOURI RIVER CORRIDOR. IN THE EXTENDED...UPPER LEVEL RIDGING TRIES TO BUILD INTO THE REGION ON THURSDAY...DAMPENED BY A SHORTWAVE TRACKING ACROSS THE NORTHERN PLAINS WHICH COULD BRING SCATTERED THUNDERSTORMS TO OUR AREA ON THURSDAY AND THURSDAY NIGHT. WILL SEE A LITTLE BIT OF WARMING ON THURSDAY IN A ENSUING SOUTHERLY FLOW OUT AHEAD OF THE APPROACHING SURFACE TROUGH...WITH HIGHS LOWER 60S TO LOWER 70S. GENERAL LONG WAVE RIDGING REMAINS OVER THE REGION THROUGH NEXT WEEKEND...WITH TEMPERATURES STAYING WELL ABOVE NORMAL. MODELS BECOME INCREASINGLY MUDDLED WITH TIMING OF WAVES EMBEDDED IN THE UPPER LEVEL FLOW THROUGH THE PERIOD...BUT COULD SEE ANOTHER SHOT OF PRECIPITATION SOMETIME DURING THE FRIDAY NIGHT TO SATURDAY TIME FRAME. && .AVIATION.../FOR THE 06Z TAF ISSUANCE/ GENERALLY VFR CONDITIONS EXPECTED THROUGH 06Z TUESDAY WITH CEILINGS AT OR ABOVE BKN050. THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS NEAR THE MISSOURI RIVER AFTER 09Z...WITH A BETTER CHANCE OF THUNDERSTORMS EAST OF I29 14Z-19Z. STRONG EAST TO SOUTHEAST WINDS GUSTING TO 35 KNOTS WILL DEVELOP ACROSS THE REGION AFTER 15Z AND PERSIST THROUGH 06Z TUESDAY. THERE WILL ALSO BE A CHANCE OF THUNDERSTORMS 00-06Z TUESDAY AHEAD OF AN APPROACHING COLDFRONT. && .FSD WATCHES/WARNINGS/ADVISORIES... IA...NONE. MN...NONE. NE...NONE. SD...NONE. && $$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
910 PM CDT SUN MAR 25 2012 .DISCUSSION.../ISSUED AT 910 PM CDT/ CURRENTLY GETTING A FEW SHOWERS AND THUNDERSTORMS ACROSS SOUTHWEST MINNESOTA. THIS SEEMS TO LINE UP PRETTY WELL WITH LOW LEVEL THETAE ADVECTION OFF THE RUC. HOWEVER RUC CURRENTLY ONLY ANALYZING LESS THAN 100 J/KG CAPE IN THAT AREA. WITH REPORTS OF PEA SIZE HAIL...THAT IS LIKELY UNDERDONE. FOLLOWED CLOSE TO THE RUC THETAE ADVECTION IN THE 900-800MB LAYER FOR PRECIP CHANCES TONIGHT...TRANSITIONING OVER TO THE NAM AFTER THAT. ANOTHER SURGE CURRENTLY ENTERING THE MISSOURI RIVER VALLEY...AND A FEW SHOWERS STARTING TO POP UP DOWN THERE. THIS AREA WILL SLOWLY TRANSITION NORTHEAST...WITH ONLY ISOLATED ACTIVITY EXPECTED. AS THIS REACHES SOUTHWEST MINNESOTA...WHERE CURRENT ACTIVITY IS ONGOING AND CAP IS WEAKEST...MAY SEE A BIT MORE SHOWER OR THUNDERSTORM COVERAGE...GENERALLY IN THE 6Z TO 12Z TIMEFRAME. THIS SAME REGION MAY SEE A REDEVELOPMENT OF ACTIVITY MONDAY AFTERNOON...AS ANOTHER DECENT AREA OF THETE ADVECTION MOVES ACROSS. MUCAPE WILL BE WEAK THROUGH THE DAY TOMORROW...THUS NOT EXPECTING ANY MORE THAN PEA SIZE HAIL WITH ANY STORMS THAT DO FORM. THE HIGHER INSTABILITY ALOFT...CLOSER TO 1-2K J/KG...WILL STAY WEST OF THE JAMES RIVER VALLEY THROUGH THE DAYLIGHT HOURS TOMORROW. BUT THAT REGION SHOULD BE UNDER THE INFLUENCE OF A STRONGER CAP...THUS THINK WE WILL PROBABLY NOT BE ABLE TO TAP INTO THAT CAPE. ONLY OTHER CHANGE WAS MINOR UPDATES TO THE HOURLY TEMP AND DEWPOINTS...TRENDED CLOSER TO THE HRRR...WHICH SEEMS TO HAVE A DECENT HANDLE ON THEM RIGHT NOW. /CHENARD .PREVIOUS DISCUSSION.../ISSUED AT 350 PM CDT/ FOR TONIGHT...EASTERLY SURFACE FETCH OF AIR WILL CONTINUE AND WILL INCREASE MODESTLY DURING THE OVERNIGHT AND LATE NIGHT HOURS. DECIDED TO ELIMINATE OUR SMALL POPS THROUGHOUT OUR WESTERN ZONES THIS EVENING. AT THIS TIME...CINS LOOK TOO HIGH TO SPARK EVEN A SHOWER IN THAT AREA AND STRATUS ALL DAY HAS NOT HELPED THE INSTABILITY FACTOR ANY. DID HANG ONTO A SLIGHT CHANCE POP LATE THIS EVENING ACROSS PARTS OF SW MN. COULD BE A FEW SPRINKLES IN THAT AREA WITH SOME CLOUD COVER BETWEEN 5 AND 10 THOUSAND FEET...BUT CERTAINLY NO BIG DEAL. AFTER MIDNIGHT...DECIDED TO GO WITH A SMALL POP IN OUR SOUTH CENTRAL SD ZONES WHERE SOME FAIRLY STRONG THETAE ADVECTION EXISTS...MAXIMIZED AROUND 800MB...PUSHING IT A BIT FURTHER EASTWARD LATE TONIGHT. COVERAGE APPEARS VERY ISOLATED. THE BIGGEST CHALLENGE TONIGHT IS TEMPERATURES...AS READINGS HAVE NOT RISEN MUCH WHERE CLOUD COVER HAS EXISTED ALL DAY. BUT WITH AN EASTERLY WIND WHICH WILL NOT GO DOWN AND SOME WARM AIR ADVECTION...TEMPERATURES MAY NOT FALL OFF ALL THAT MUCH IN OUR AREAS THAT DID NOT WARM UP. ON MONDAY...STRONG SHORT WAVE ENERGY MOVES INTO THE WESTERN PLAINS AS THE DAY PROGRESSES. ABOUT THE ONLY CHANCES WE HAVE OF ANY THUNDERSTORM ACTIVITY IN OUR FORECAST AREA WILL BE ALONG AND EAST OF THE JAMES RIVER VALLEY IN THE MORNING...ASSOCIATED WITH THE AFOREMENTIONED STRONG THETAE ADVECTION LIFTING TO THE NORTHEAST. LATE IN THE DAY...THERE MAY ALSO BE AN ISOLATED THUNDERSTORM IN SOUTH CENTRAL SD CLOSER TO THE WIND SHIFT. RIGHT NOW...SEVERE CHANCES LOOK EXTREMELY LIMITED THROUGH MONDAY WITH A LACK OF FOCUS MECHANISM TO REALLY HANG YOUR HAT ON. MUCH OF THE DYNAMICS OVERALL IS STAYING WEST OF OUR AREA. IT WILL BE QUITE WINDY ON MONDAY AS BOTH THE PRESSURE GRADIENT AND WINDS ALOFT INCREASE...WITH SE WINDS SOLIDLY IN THE 20 TO 35 MPH CATEGORY. AS THE SURFACE WARM FRONT LIFTS NORTHEASTWARD...HEATING SHOULD BE DRAMATIC IN OUR SW AND SOUTH CENTRAL ZONES SOUTH OF THE FRONTAL BOUNDARY. GIVEN THE 900 TO 850MB TEMPERATURES...IT LOOKS LIKE THE WARM MAV GUIDANCE ARE THE ONLY NUMBERS THAT RIGHT NOW LOOK THE CLOSEST FOR THIS FORECAST AREA... ESPECIALLY FOR OUR ZONES SOUTH OF THE FRONT. HAVE A STRONG 25 DEGREE THERMAL GRADIENT FOR HIGHS FROM SW TO NE IN OUR AREA. ON MONDAY NIGHT THE DEEPENING UPPER LEVEL LOW TRACKS FROM WYOMING TO NORTH DAKOTA THROUGH THE NIGHT...WITH THE SURFACE REFLECTION IN THE FORM OF A SURFACE BOUNDARY SWINGING ACROSS OUR AREA. SEVERE WEATHER NOW NOT LOOKING AS IMPRESSIVE WITH ELEVATED CAPE PRETTY WEAK OVER OUR CWA IN CONJUNCTION WITH INCREDIBLE SHEAR...AROUND 60 KTS...TEARING ANY STORMS APART. THINK THE BIGGER THREAT MIGHT BE A STRONG WIND GUST WITH THE FRONTAL SURGE...WITH STRONG WINDS ALOFT AND PRESSURE RISES OF 6 TO 7 MB JUST BEHIND THE FRONT. EXPECT THAT ANY CONVECTION THAT OCCURS WILL BE TIED TO LOW LEVEL CONVERGENCE AND THETA E ADVECTION OUT AHEAD OF THE BOUNDARY. LOW TEMPERATURES ON MONDAY NIGHT WILL BE MILD...IN THE LOWER TO UPPER 50S...WITH TEMPERATURES RISING FOR A WHILE IN THE NORTHEAST AS THE WARM FRONT LIFTS TO THE NORTH THROUGH THE EVENING. BY EARLY ON TUESDAY THE BOUNDARY WILL BE EXITING OUR AREA...TAKING ANY CONVECTION THAT FORMS WITH IT. IT WILL BE WINDY WITH STRONG LOW LEVEL COLD AIR ADVECTION...A TIGHT GRADIENT...AND PRESSURE RISES...THOUGH WINDS ALOFT WILL BE TAPERING DOWN DURING THE DAY WITH 850 MB WIND SPEEDS FALLING TO 25 TO 35 KTS BY EARLY AFTERNOON. MAY BE A POSSIBILITY OF A WIND ADVISORY AT SOME POINT. EVEN WITH COLD AIR ADVECTION...WITH MORE SUN ON TUESDAY HIGHS LOOK TO REACH THE MID 60S TO LOWER 70S. DEFINITELY STILL LOOKING LIKE AN ENHANCED FIRE DANGER ACROSS OUR SOUTH ON TUESDAY AFTERNOON WITH LOWER DEWPOINTS STREAMING IN BEHIND THE EXITING FRONTAL BOUNDARY...YIELDING AFTERNOON RELATIVE HUMIDITY VALUES OF AROUND 20 PERCENT THROUGH THE MISSOURI RIVER CORRIDOR. WHILE STILL PLENTY BREEZY OVER THAT AREA DURING THE AFTERNOON...HIGHER WINDS APPEAR TO BE FOUND TO THE NORTH...AND WITH THE EXACT AMOUNT OF RAINFALL THROUGH THAT AREA STILL SOMEWHAT UNCERTAIN AT THIS TIME POTENTIAL FIRE HEADLINES WILL BE EVOLVING OVER THE NEXT 24 HOURS OR SO. WITH THE SYSTEM CONTINUING TO PULL AWAY THE GRADIENT WILL RELAX BY TUESDAY NIGHT...WITH WINDS DYING AND TEMPERATURES FALLING INTO THE UPPER 30S TO MID 40S ACROSS THE AREA. HIGH PRESSURE SETTLES INTO THE REGION ON WEDNESDAY WITH THE BRUNT OF THE COOLER AIRMASS FALLING INTO THE MIDWEST BEHIND THE EXITING LOW OVER THE GREAT LAKES. WITH THAT...HIGHS WILL ONLY REACH THE UPPER 50S OVER PORTIONS OF OUR SOUTHWESTERN MINNESOTA ZONES...TO THE UPPER 60S THROUGH THE MISSOURI RIVER CORRIDOR. IN THE EXTENDED...UPPER LEVEL RIDGING TRIES TO BUILD INTO THE REGION ON THURSDAY...DAMPENED BY A SHORTWAVE TRACKING ACROSS THE NORTHERN PLAINS WHICH COULD BRING SCATTERED THUNDERSTORMS TO OUR AREA ON THURSDAY AND THURSDAY NIGHT. WILL SEE A LITTLE BIT OF WARMING ON THURSDAY IN A ENSUING SOUTHERLY FLOW OUT AHEAD OF THE APPROACHING SURFACE TROUGH...WITH HIGHS LOWER 60S TO LOWER 70S. GENERAL LONG WAVE RIDGING REMAINS OVER THE REGION THROUGH NEXT WEEKEND...WITH TEMPERATURES STAYING WELL ABOVE NORMAL. MODELS BECOME INCREASINGLY MUDDLED WITH TIMING OF WAVES EMBEDDED IN THE UPPER LEVEL FLOW THROUGH THE PERIOD...BUT COULD SEE ANOTHER SHOT OF PRECIPITATION SOMETIME DURING THE FRIDAY NIGHT TO SATURDAY TIME FRAME. && .AVIATION.../FOR THE 18Z TAF ISSUANCE/ GENERALLY VFR CONDITIONS EXPECTED THROUGH 00Z TUESDAY WITH CEILINGS AT OR ABOVE BKN050. THERE WILL BE A CHANCE OF THUNDERSTORMS NEAR THE MISSOURI RIVER AFTER 09Z AND THEN WILL SPREAD NORTHEAST THROUGH MONDAY MORNING AND WILL GENERALLY BE LOCATED EAST OF I29 BY 18Z MONDAY. && .FSD WATCHES/WARNINGS/ADVISORIES... IA...NONE. MN...NONE. NE...NONE. SD...NONE. && $$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
323 PM EDT SAT MAR 24 2012 .SYNOPSIS... LOW PRESSURE OVER THE OHIO VALLEY WILL MOVE EAST THEN SOUTHEAST TODAY AND TONIGHT. BY SUNDAY NIGHT THE LOW WILL BE OFF THE CAROLINA COAST. HIGH PRESSURE WILL BUILD OVER THE REGION MONDAY AND TUESDAY. && .NEAR TERM /THROUGH SUNDAY/... AS OF 300 PM EDT SATURDAY... UPDATED ISC GRIDS FOR SEVERE THUNDERSTORM WATCH 107 IN EFFECT UNTIL 10 PM TONIGHT. AS OF 1250 PM SATURDAY... UPDATED ISC GRIDS FOR SEVERE THUNDERSTORM WATCH 105 IN EFFECT UNTIL 8 PM EDT THIS EVENING. AS OF 1150 AM EDT SATURDAY... CONVECTION WHICH TAPERED OFF THIS MORNING ALLOWING SOME SUNSHINE TO RETURN FOR THE WEST...WILL REDEVELOP THIS AFTERNOON INTO TONIGHT. SOME OF THE STORMS WILL BE STRONG TO SEVERE WITH THE POTENTIAL FOR LOCALLY HEAVY RAINS. THE UPPER LOW TO OUR WEST WILL STEADILY APPROACH THIS AFTERNOON AND MOVE ACROSS THE SRN APPALACHIANS TONIGHT. LIKE THE HRRR FOR EARLY THIS AFTERNOON AND SHAPE POPS CLOSE TO SOLUTION. AS OF 915 AM EDT SATURDAY... ADJUSTED TEMPERATURES AND POPS ACCORDING TO LATEST OBS AND RADAR TRENDS. EXPANDED THE MENTION OF GUSTY WINDS AND HAIL FURTHER NORTH TO MATCH SPC LATEST DAY1 OUTLOOK. HWO WAS UPDATED. PNS OUT FOR HIGH MIN TEMPERATURES. ALSO ANOTHER PNS COMING OUT FOR RAINFALL AMOUNTS. THE UPPER LOW IS MOVING EAST WITH COLD POOL WHICH WILL RESULT IN NUMEROUS SHOWERS AND THUNDERSTORMS THIS AFTERNOON INTO TONIGHT. LOOK FOR SEVERAL ISC UPDATES TODAY WITH THE ACTIVE WEATHER EXPECTED. AS OF 410 AM EDT SATURDAY... EXPECTING SEVERAL BANDS OF SHOWERS AND THUNDERSTORMS TODAY AND TONIGHT. FIRST AREA WAS OVER THE CENTRAL AND EASTERN COUNTY WARNING AREA EARLY THIS MORNING AND WAS MOVING NORTHEAST AROUND 20 MPH. THE NEXT BAND EXTENDS FROM OHIO INTO EASTERN TENNESSEE. LOCAL WRF AND HRRR BRING THIS BAND INTO THE WESTERN COUNTY WARNING AREA BY 8AM. AS THE UPPER LOW MOVES EAST THIS MOVING SO WILL THE SHOWERS AND THUNDERSTORMS. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE FORECAST AREA THIS AFTERNOON. COLDER AIR ALOFT ASSOCIATED WITH THE UPPER LOW WILL REACH THE FORECAST AREA TODAY...CREATING LARGE LAPSE RATES AND LOWERING THE FREEZING LEVEL. GUSTY WINDS AND LARGE HAIL WILL BE A THREAT WITH ANY STRONGER STORMS...ESPECIALLY THIS AFTERNOON AND EVENING. THE UPPER LOW MOVES SOUTHEAST INTO SOUTH CAROLINA BY SUNDAY MORNING. EXPECT COVERAGE AND PROBABILITY OF PRECIPITATION TO DECREASE LATE TONIGHT. THERE WAS A BREAK IN THE CLOUD COVER AHEAD OF THE SHOWERS AND THUNDERSTORMS APPROACHING FROM THE WEST. FOG MAY DEVELOP EARLY THIS MORNING AS THE CLOUDS BRIEFLY CLEAR. WITH ALL THE PRECIPITATION EXPECTED TODAY...HAVE GONE ON THE COOL SIDE OF GUIDANCE. STAYED CLOSE TO A BLEND OF BIAS CORRECTED MAV/MET GUIDANCE FOR LOWS TONIGHT. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... AS OF 330 AM EST SATURDAY... SUNDAY MORNING WILL START OUT WITH THE UPPER LEVEL LOW PASSING JUST TO THE SOUTH OF OUR AREA...POSSIBLY CLIPPING OUR NORTH CAROLINA COUNTIES. IN ANY EVENT...EXPECT TO SEE GREATER COVERAGE OF SHOWER ACTIVITY NORTH OF INTERSTATE 81...AS A SLOT OF DRIER AIR WORKS ITS WAY IN SOUTH CLOSER TO THE LOW. COVERAGE WILL INCREASE FURTHER DURING THE AFTERNOON AS DAYTIME HEATING HELPS DESTABILIZE THE ATMOSPHERE...AND WILL NOT BE SURPRISED TO SEE A FEW THUNDERSTORMS DEVELOP BY LATE MORNING. WITH THE UPPER LOW PASSING SO CLOSE TO OUR AREA...BELIEVE THAT HAIL WILL BE A CONCERN IN THE STRONGER SHOWER AND THUNDERSTORM ACTIVITY...BUT EXPECT MOST HAIL TO BE IN THE PEA TO DIME SIZE RANGE WHERE IT OCCURS. SHOWER AND THUNDERSTORM ACTIVITY WILL DECREASE FROM WEST TO EAST BY LATE AFTERNOON AS THE UPPER LOW CONTINUES TO PUSH OFF THE ATLANTIC COAST...AND SHOWER ACTIVITY IS EXPECTED TO BE CONFINED TO THE MOUNTAINS...MAINLY IN SOUTHEAST WEST VIRGINIA BY LATE SUNDAY EVENING. DESPITE THE PASSAGE OF THE UPPER LOW...SUNDAY NIGHT TEMPERATURES WILL REMAIN MILD ACROSS OUR AREA...WITH OVERNIGHT LOWS RANGING FROM THE LOW TO MID 50S EAST...TO THE UPPER 40S WEST. IT WILL BE MONDAY MORNING WHEN WE SEE A CHANGE IN OUR WEATHER PATTERN AS ANOTHER COLD FRONT BRINGS A SHOT OF COOLER CANADIAN AIR INTO OUR AREA. MONDAY AFTERNOON TEMPERATURES ARE EXPECTED TO REMAIN MILD ACROSS OUR AREA...ALBEIT A LITTLE COOLER...HOWEVER IT WILL BE MONDAY NIGHT/TUESDAY MORNING TEMPERATURES THAT WILL BE OF CONCERN AS LOWS FALL INTO THE 30S ACROSS THE MOUNTAINS. BELIEVE THAT NEAR FREEZING TEMPERATURES WILL BE CONFINED TO GREENBRIER COUNTY IN SOUTHEAST WEST VIRGINIA...AS WELL AS THE ALLEGHANY HIGHLANDS IN VIRGINIA...LOCATIONS THAT HAVE NOT EXPERIENCED A START TO THE GROWING SEASON TO THE SAME EXTENT THAT HAS OCCURRED IN LOWER ELEVATIONS. THAT STATED...IT WOULD BE A GOOD IDEA TO CONSIDER PRECAUTIONS AGAINST THE COLD FOR ANY SENSITIVE VEGETATION WHICH HAS STARTED TO GROW IN YOUR AREA. HIGH PRESSURE WILL SLIDE EAST ON TUESDAY AFTERNOON...ALLOWING WINDS TO BECOME SOUTHERLY ACROSS OUR AREA. WITH A RIDGE OF UPPER LEVEL HIGH PRESSURE BUILDING IN FROM THE WEST LATE TUESDAY EVENING... OVERNIGHT TEMPERATURES WILL BE CONSIDERABLY WARMER...WITH LOWS EXPECTED TO RANGE FROM THE MID 40S IN THE WEST...TO THE UPPER 30S IN THE EAST. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 330 AM EDT SATURDAY... ON WEDNESDAY...A HIGH PRESSURE RIDGE WILL SLIDE EAST OFF THE COAST. SOUTHERLY FLOW RETURNS WITH MODERATING TEMPERATURES FOR THE REMAINDER OF THE WORK WEEK. LIGHT RAIN SHOWERS ARE POSSIBLE WEDNESDAY INTO THURSDAY AS A WEAK COOL FRONT PASSES OVER THE REGION. THIS RAIN WILL NOT BE ANY WHERE CLOSE IN INTENSITY TO THIS WEEKENDS RAIN EVENT. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... AS OF 1159 AM EDT SATURDAY... EXPECT SEVERAL PERIODS OF SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH 06Z SUNDAY. CEILINGS AND VISIBILITIES WILL LOWER TO MVFR/IFR IN ASSOCIATION WITH THE SHOWERS AND STORMS. SOME OF THE STRONGER STORMS TODAY MAY PRODUCE GUSTY WINDS AND LARGE HAIL...MAINLY THIS AFTERNOON AND EVENING. COVERAGE OF PRECIPITATION WILL DIMINISH TONIGHT. LOW CLOUDS AND FOG WILL FILL IN OVERNIGHT WITH CEILINGS LOWERING TO IFR/MVFR LEVELS. HAVE LOWERED VISIBILITY TO LIFR AT LYH WITH MEDIUM CONFIDENCE. IF NORTHWEST SURFACE AND LOW LEVEL WINDS ARE A LITTLE STRONGER THAN EXPECTED THEN PROBABILITY OF LIFR OR IFR FOG WILL BE LOWER. SHRA WILL DEVELOP AGAIN ACROSS THE AREA SUN...BUT WITH CONSIDERABLE LESS INSTABILITY INDICATED AND A COLDER/MORE STABLE SFC ENVIRONMENT...DO NOT ANTICIPATE MUCH TSRA ACTIVITY SUN...JUST SHOWERS. DRIER WEATHER AND VFR CONDITIONS ARE EXPECTED BEHIND THIS WEATHER SYSTEM SUNDAY NIGHT THROUGH TUESDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...PC LONG TERM...PC AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1257 PM EDT SAT MAR 24 2012 .SYNOPSIS... LOW PRESSURE OVER THE OHIO VALLEY WILL MOVE EAST THEN SOUTHEAST TODAY AND TONIGHT. BY SUNDAY NIGHT THE LOW WILL BE OFF THE CAROLINA COAST. HIGH PRESSURE WILL BUILD OVER THE REGION MONDAY AND TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1250 PM SATURDAY... UPDATED ISC GRIDS FOR SEVERE THUNDERSTORM WATCH 105 IN EFFECT UNTIL 8 PM EDT THIS EVENING. AS OF 1150 AM EDT SATURDAY... CONVECTION WHICH TAPERED OFF THIS MORNING ALLOWING SOME SUNSHINE TO RETURN FOR THE WEST...WILL REDEVELOP THIS AFTERNOON INTO TONIGHT. SOME OF THE STORMS WILL BE STRONG TO SEVERE WITH THE POTENTIAL FOR LOCALLY HEAVY RAINS. THE UPPER LOW TO OUR WEST WILL STEADILY APPROACH THIS AFTERNOON AND MOVE ACROSS THE SRN APPALACHIANS TONIGHT. LIKE THE HRRR FOR EARLY THIS AFTERNOON AND SHAPE POPS CLOSE TO SOLUTION. AS OF 915 AM EDT SATURDAY... ADJUSTED TEMPERATURES AND POPS ACCORDING TO LATEST OBS AND RADAR TRENDS. EXPANDED THE MENTION OF GUSTY WINDS AND HAIL FURTHER NORTH TO MATCH SPC LATEST DAY1 OUTLOOK. HWO WAS UPDATED. PNS OUT FOR HIGH MIN TEMPERATURES. ALSO ANOTHER PNS COMING OUT FOR RAINFALL AMOUNTS. THE UPPER LOW IS MOVING EAST WITH COLD POOL WHICH WILL RESULT IN NUMEROUS SHOWERS AND THUNDERSTORMS THIS AFTERNOON INTO TONIGHT. LOOK FOR SEVERAL ISC UPDATES TODAY WITH THE ACTIVE WEATHER EXPECTED. AS OF 410 AM EDT SATURDAY... EXPECTING SEVERAL BANDS OF SHOWERS AND THUNDERSTORMS TODAY AND TONIGHT. FIRST AREA WAS OVER THE CENTRAL AND EASTERN COUNTY WARNING AREA EARLY THIS MORNING AND WAS MOVING NORTHEAST AROUND 20 MPH. THE NEXT BAND EXTENDS FROM OHIO INTO EASTERN TENNESSEE. LOCAL WRF AND HRRR BRING THIS BAND INTO THE WESTERN COUNTY WARNING AREA BY 8AM. AS THE UPPER LOW MOVES EAST THIS MOVING SO WILL THE SHOWERS AND THUNDERSTORMS. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE FORECAST AREA THIS AFTERNOON. COLDER AIR ALOFT ASSOCIATED WITH THE UPPER LOW WILL REACH THE FORECAST AREA TODAY...CREATING LARGE LAPSE RATES AND LOWERING THE FREEZING LEVEL. GUSTY WINDS AND LARGE HAIL WILL BE A THREAT WITH ANY STRONGER STORMS...ESPECIALLY THIS AFTERNOON AND EVENING. THE UPPER LOW MOVES SOUTHEAST INTO SOUTH CAROLINA BY SUNDAY MORNING. EXPECT COVERAGE AND PROBABILITY OF PRECIPITATION TO DECREASE LATE TONIGHT. THERE WAS A BREAK IN THE CLOUD COVER AHEAD OF THE SHOWERS AND THUNDERSTORMS APPROACHING FROM THE WEST. FOG MAY DEVELOP EARLY THIS MORNING AS THE CLOUDS BRIEFLY CLEAR. WITH ALL THE PRECIPITATION EXPECTED TODAY...HAVE GONE ON THE COOL SIDE OF GUIDANCE. STAYED CLOSE TO A BLEND OF BIAS CORRECTED MAV/MET GUIDANCE FOR LOWS TONIGHT. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... AS OF 330 AM EST SATURDAY... SUNDAY MORNING WILL START OUT WITH THE UPPER LEVEL LOW PASSING JUST TO THE SOUTH OF OUR AREA...POSSIBLY CLIPPING OUR NORTH CAROLINA COUNTIES. IN ANY EVENT...EXPECT TO SEE GREATER COVERAGE OF SHOWER ACTIVITY NORTH OF INTERSTATE 81...AS A SLOT OF DRIER AIR WORKS ITS WAY IN SOUTH CLOSER TO THE LOW. COVERAGE WILL INCREASE FURTHER DURING THE AFTERNOON AS DAYTIME HEATING HELPS DESTABILIZE THE ATMOSPHERE...AND WILL NOT BE SURPRISED TO SEE A FEW THUNDERSTORMS DEVELOP BY LATE MORNING. WITH THE UPPER LOW PASSING SO CLOSE TO OUR AREA...BELIEVE THAT HAIL WILL BE A CONCERN IN THE STRONGER SHOWER AND THUNDERSTORM ACTIVITY...BUT EXPECT MOST HAIL TO BE IN THE PEA TO DIME SIZE RANGE WHERE IT OCCURS. SHOWER AND THUNDERSTORM ACTIVITY WILL DECREASE FROM WEST TO EAST BY LATE AFTERNOON AS THE UPPER LOW CONTINUES TO PUSH OFF THE ATLANTIC COAST...AND SHOWER ACTIVITY IS EXPECTED TO BE CONFINED TO THE MOUNTAINS...MAINLY IN SOUTHEAST WEST VIRGINIA BY LATE SUNDAY EVENING. DESPITE THE PASSAGE OF THE UPPER LOW...SUNDAY NIGHT TEMPERATURES WILL REMAIN MILD ACROSS OUR AREA...WITH OVERNIGHT LOWS RANGING FROM THE LOW TO MID 50S EAST...TO THE UPPER 40S WEST. IT WILL BE MONDAY MORNING WHEN WE SEE A CHANGE IN OUR WEATHER PATTERN AS ANOTHER COLD FRONT BRINGS A SHOT OF COOLER CANADIAN AIR INTO OUR AREA. MONDAY AFTERNOON TEMPERATURES ARE EXPECTED TO REMAIN MILD ACROSS OUR AREA...ALBEIT A LITTLE COOLER...HOWEVER IT WILL BE MONDAY NIGHT/TUESDAY MORNING TEMPERATURES THAT WILL BE OF CONCERN AS LOWS FALL INTO THE 30S ACROSS THE MOUNTAINS. BELIEVE THAT NEAR FREEZING TEMPERATURES WILL BE CONFINED TO GREENBRIER COUNTY IN SOUTHEAST WEST VIRGINIA...AS WELL AS THE ALLEGHANY HIGHLANDS IN VIRGINIA...LOCATIONS THAT HAVE NOT EXPERIENCED A START TO THE GROWING SEASON TO THE SAME EXTENT THAT HAS OCCURRED IN LOWER ELEVATIONS. THAT STATED...IT WOULD BE A GOOD IDEA TO CONSIDER PRECAUTIONS AGAINST THE COLD FOR ANY SENSITIVE VEGETATION WHICH HAS STARTED TO GROW IN YOUR AREA. HIGH PRESSURE WILL SLIDE EAST ON TUESDAY AFTERNOON...ALLOWING WINDS TO BECOME SOUTHERLY ACROSS OUR AREA. WITH A RIDGE OF UPPER LEVEL HIGH PRESSURE BUILDING IN FROM THE WEST LATE TUESDAY EVENING... OVERNIGHT TEMPERATURES WILL BE CONSIDERABLY WARMER...WITH LOWS EXPECTED TO RANGE FROM THE MID 40S IN THE WEST...TO THE UPPER 30S IN THE EAST. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 330 AM EDT SATURDAY... ON WEDNESDAY...A HIGH PRESSURE RIDGE WILL SLIDE EAST OFF THE COAST. SOUTHERLY FLOW RETURNS WITH MODERATING TEMPERATURES FOR THE REMAINDER OF THE WORK WEEK. LIGHT RAIN SHOWERS ARE POSSIBLE WEDNESDAY INTO THURSDAY AS A WEAK COOL FRONT PASSES OVER THE REGION. THIS RAIN WILL NOT BE ANY WHERE CLOSE IN INTENSITY TO THIS WEEKENDS RAIN EVENT. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... AS OF 1159 AM EDT SATURDAY... EXPECT SEVERAL PERIODS OF SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH 06Z SUNDAY. CEILINGS AND VISIBILITIES WILL LOWER TO MVFR/IFR IN ASSOCIATION WITH THE SHOWERS AND STORMS. SOME OF THE STRONGER STORMS TODAY MAY PRODUCE GUSTY WINDS AND LARGE HAIL...MAINLY THIS AFTERNOON AND EVENING. COVERAGE OF PRECIPITATION WILL DIMINISH TONIGHT. LOW CLOUDS AND FOG WILL FILL IN OVERNIGHT WITH CEILINGS LOWERING TO IFR/MVFR LEVELS. HAVE LOWERED VISIBILITY TO LIFR AT LYH WITH MEDIUM CONFIDENCE. IF NORTHWEST SURFACE AND LOW LEVEL WINDS ARE A LITTLE STRONGER THAN EXPECTED THEN PROBABILITY OF LIFR OR IFR FOG WILL BE LOWER. SHRA WILL DEVELOP AGAIN ACROSS THE AREA SUN...BUT WITH CONSIDERABLE LESS INSTABILITY INDICATED AND A COLDER/MORE STABLE SFC ENVIRONMENT...DO NOT ANTICIPATE MUCH TSRA ACTIVITY SUN...JUST SHOWERS. DRIER WEATHER AND VFR CONDITIONS ARE EXPECTED BEHIND THIS WEATHER SYSTEM SUNDAY NIGHT THROUGH TUESDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...NF LONG TERM...RCS AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1201 PM EDT SAT MAR 24 2012 .SYNOPSIS... LOW PRESSURE OVER THE OHIO VALLEY WILL MOVE EAST THEN SOUTHEAST TODAY AND TONIGHT. BY SUNDAY NIGHT THE LOW WILL BE OFF THE CAROLINA COAST. HIGH PRESSURE WILL BUILD OVER THE REGION MONDAY AND TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1150 AM EDT SATURDAY... CONVECTION WHICH TAPERED OFF THIS MORNING ALLOWING SOME SUNSHINE TO RETURN FOR THE WEST...WILL REDEVELOP THIS AFTERNOON INTO TONIGHT. SOME OF THE STORMS WILL BE STRONG TO SEVERE WITH THE POTENTIAL FOR LOCALLY HEAVY RAINS. THE UPPER LOW TO OUR WEST WILL STEADILY APPROACH THIS AFTERNOON AND MOVE ACROSS THE SRN APPALACHIANS TONIGHT. LIKE THE HRRR FOR EARLY THIS AFTERNOON AND SHAPE POPS CLOSE TO SOLUTION. AS OF 915 AM EDT SATURDAY... ADJUSTED TEMPERATURES AND POPS ACCORDING TO LATEST OBS AND RADAR TRENDS. EXPANDED THE MENTION OF GUSTY WINDS AND HAIL FURTHER NORTH TO MATCH SPC LATEST DAY1 OUTLOOK. HWO WAS UPDATED. PNS OUT FOR HIGH MIN TEMPERATURES. ALSO ANOTHER PNS COMING OUT FOR RAINFALL AMOUNTS. THE UPPER LOW IS MOVING EAST WITH COLD POOL WHICH WILL RESULT IN NUMEROUS SHOWERS AND THUNDERSTORMS THIS AFTERNOON INTO TONIGHT. LOOK FOR SEVERAL ISC UPDATES TODAY WITH THE ACTIVE WEATHER EXPECTED. AS OF 410 AM EDT SATURDAY... EXPECTING SEVERAL BANDS OF SHOWERS AND THUNDERSTORMS TODAY AND TONIGHT. FIRST AREA WAS OVER THE CENTRAL AND EASTERN COUNTY WARNING AREA EARLY THIS MORNING AND WAS MOVING NORTHEAST AROUND 20 MPH. THE NEXT BAND EXTENDS FROM OHIO INTO EASTERN TENNESSEE. LOCAL WRF AND HRRR BRING THIS BAND INTO THE WESTERN COUNTY WARNING AREA BY 8AM. AS THE UPPER LOW MOVES EAST THIS MOVING SO WILL THE SHOWERS AND THUNDERSTORMS. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE FORECAST AREA THIS AFTERNOON. COLDER AIR ALOFT ASSOCIATED WITH THE UPPER LOW WILL REACH THE FORECAST AREA TODAY...CREATING LARGE LAPSE RATES AND LOWERING THE FREEZING LEVEL. GUSTY WINDS AND LARGE HAIL WILL BE A THREAT WITH ANY STRONGER STORMS...ESPECIALLY THIS AFTERNOON AND EVENING. THE UPPER LOW MOVES SOUTHEAST INTO SOUTH CAROLINA BY SUNDAY MORNING. EXPECT COVERAGE AND PROBABILITY OF PRECIPITATION TO DECREASE LATE TONIGHT. THERE WAS A BREAK IN THE CLOUD COVER AHEAD OF THE SHOWERS AND THUNDERSTORMS APPROACHING FROM THE WEST. FOG MAY DEVELOP EARLY THIS MORNING AS THE CLOUDS BRIEFLY CLEAR. WITH ALL THE PRECIPITATION EXPECTED TODAY...HAVE GONE ON THE COOL SIDE OF GUIDANCE. STAYED CLOSE TO A BLEND OF BIAS CORRECTED MAV/MET GUIDANCE FOR LOWS TONIGHT. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... AS OF 330 AM EST SATURDAY... SUNDAY MORNING WILL START OUT WITH THE UPPER LEVEL LOW PASSING JUST TO THE SOUTH OF OUR AREA...POSSIBLY CLIPPING OUR NORTH CAROLINA COUNTIES. IN ANY EVENT...EXPECT TO SEE GREATER COVERAGE OF SHOWER ACTIVITY NORTH OF INTERSTATE 81...AS A SLOT OF DRIER AIR WORKS ITS WAY IN SOUTH CLOSER TO THE LOW. COVERAGE WILL INCREASE FURTHER DURING THE AFTERNOON AS DAYTIME HEATING HELPS DESTABILIZE THE ATMOSPHERE...AND WILL NOT BE SURPRISED TO SEE A FEW THUNDERSTORMS DEVELOP BY LATE MORNING. WITH THE UPPER LOW PASSING SO CLOSE TO OUR AREA...BELIEVE THAT HAIL WILL BE A CONCERN IN THE STRONGER SHOWER AND THUNDERSTORM ACTIVITY...BUT EXPECT MOST HAIL TO BE IN THE PEA TO DIME SIZE RANGE WHERE IT OCCURS. SHOWER AND THUNDERSTORM ACTIVITY WILL DECREASE FROM WEST TO EAST BY LATE AFTERNOON AS THE UPPER LOW CONTINUES TO PUSH OFF THE ATLANTIC COAST...AND SHOWER ACTIVITY IS EXPECTED TO BE CONFINED TO THE MOUNTAINS...MAINLY IN SOUTHEAST WEST VIRGINIA BY LATE SUNDAY EVENING. DESPITE THE PASSAGE OF THE UPPER LOW...SUNDAY NIGHT TEMPERATURES WILL REMAIN MILD ACROSS OUR AREA...WITH OVERNIGHT LOWS RANGING FROM THE LOW TO MID 50S EAST...TO THE UPPER 40S WEST. IT WILL BE MONDAY MORNING WHEN WE SEE A CHANGE IN OUR WEATHER PATTERN AS ANOTHER COLD FRONT BRINGS A SHOT OF COOLER CANADIAN AIR INTO OUR AREA. MONDAY AFTERNOON TEMPERATURES ARE EXPECTED TO REMAIN MILD ACROSS OUR AREA...ALBEIT A LITTLE COOLER...HOWEVER IT WILL BE MONDAY NIGHT/TUESDAY MORNING TEMPERATURES THAT WILL BE OF CONCERN AS LOWS FALL INTO THE 30S ACROSS THE MOUNTAINS. BELIEVE THAT NEAR FREEZING TEMPERATURES WILL BE CONFINED TO GREENBRIER COUNTY IN SOUTHEAST WEST VIRGINIA...AS WELL AS THE ALLEGHANY HIGHLANDS IN VIRGINIA...LOCATIONS THAT HAVE NOT EXPERIENCED A START TO THE GROWING SEASON TO THE SAME EXTENT THAT HAS OCCURRED IN LOWER ELEVATIONS. THAT STATED...IT WOULD BE A GOOD IDEA TO CONSIDER PRECAUTIONS AGAINST THE COLD FOR ANY SENSITIVE VEGETATION WHICH HAS STARTED TO GROW IN YOUR AREA. HIGH PRESSURE WILL SLIDE EAST ON TUESDAY AFTERNOON...ALLOWING WINDS TO BECOME SOUTHERLY ACROSS OUR AREA. WITH A RIDGE OF UPPER LEVEL HIGH PRESSURE BUILDING IN FROM THE WEST LATE TUESDAY EVENING... OVERNIGHT TEMPERATURES WILL BE CONSIDERABLY WARMER...WITH LOWS EXPECTED TO RANGE FROM THE MID 40S IN THE WEST...TO THE UPPER 30S IN THE EAST. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 330 AM EDT SATURDAY... ON WEDNESDAY...A HIGH PRESSURE RIDGE WILL SLIDE EAST OFF THE COAST. SOUTHERLY FLOW RETURNS WITH MODERATING TEMPERATURES FOR THE REMAINDER OF THE WORK WEEK. LIGHT RAIN SHOWERS ARE POSSIBLE WEDNESDAY INTO THURSDAY AS A WEAK COOL FRONT PASSES OVER THE REGION. THIS RAIN WILL NOT BE ANY WHERE CLOSE IN INTENSITY TO THIS WEEKENDS RAIN EVENT. && .AVIATION /16Z SATURDAY THROUGH WEDNESDAY/... AS OF 1159 AM EDT SATURDAY... EXPECT SEVERAL PERIODS OF SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH 06Z SUNDAY. CEILINGS AND VISIBILITIES WILL LOWER TO MVFR/IFR IN ASSOCIATION WITH THE SHOWERS AND STORMS. SOME OF THE STRONGER STORMS TODAY MAY PRODUCE GUSTY WINDS AND LARGE HAIL...MAINLY THIS AFTERNOON AND EVENING. COVERAGE OF PRECIPITATION WILL DIMINISH TONIGHT. LOW CLOUDS AND FOG WILL FILL IN OVERNIGHT WITH CEILINGS LOWERING TO IFR/MVFR LEVELS. HAVE LOWERED VISIBILITY TO LIFR AT LYH WITH MEDIUM CONFIDENCE. IF NORTHWEST SURFACE AND LOW LEVEL WINDS ARE A LITTLE STRONGER THAN EXPECTED THEN PROBABILITY OF LIFR OR IFR FOG WILL BE LOWER. SHRA WILL DEVELOP AGAIN ACROSS THE AREA SUN...BUT WITH CONSIDERABLE LESS INSTABILITY INDICATED AND A COLDER/MORE STABLE SFC ENVIRONMENT...DO NOT ANTICIPATE MUCH TSRA ACTIVITY SUN...JUST SHOWERS. DRIER WEATHER AND VFR CONDITIONS ARE EXPECTED BEHIND THIS WEATHER SYSTEM SUNDAY NIGHT THROUGH TUESDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...NF LONG TERM...RCS AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
917 AM EDT SAT MAR 24 2012 .SYNOPSIS... LOW PRESSURE OVER THE OHIO VALLEY WILL MOVE EAST THEN SOUTHEAST TODAY AND TONIGHT. BY SUNDAY NIGHT THE LOW WILL BE OFF THE CAROLINA COAST. HIGH PRESSURE WILL BUILD OVER THE REGION MONDAY AND TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... ADJUSTED TEMPERATURES AND POPS ACCORDING TO LATEST OBS AND RADAR TRENDS. EXPANDED THE MENTION OF GUSTY WINDS AND HAIL FURTHER NORTH TO MATCH SPC LATEST DAY1 OUTLOOK. HWO WAS UPDATED. PNS OUT FOR HIGH MIN TEMPERATURES. ALSO ANOTHER PNS COMING OUT FOR RAINFALL AMOUNTS. THE UPPER LOW IS MOVING EAST WITH COLD POOL WHICH WILL RESULT IN NUMEROUS SHOWERS AND THUNDERSTORMS THIS AFTERNOON INTO TONIGHT. LOOK FOR SEVERAL ISC UPDATES TODAY WITH THE ACTIVE WEATHER EXPECTED. AS OF 410 AM EDT SATURDAY... EXPECTING SEVERAL BANDS OF SHOWERS AND THUNDERSTORMS TODAY AND TONIGHT. FIRST AREA WAS OVER THE CENTRAL AND EASTERN COUNTY WARNING AREA EARLY THIS MORNING AND WAS MOVING NORTHEAST AROUND 20 MPH. THE NEXT BAND EXTENDS FROM OHIO INTO EASTERN TENNESSEE. LOCAL WRF AND HRRR BRING THIS BAND INTO THE WESTERN COUNTY WARNING AREA BY 8AM. AS THE UPPER LOW MOVES EAST THIS MOVING SO WILL THE SHOWERS AND THUNDERSTORMS. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE FORECAST AREA THIS AFTERNOON. COLDER AIR ALOFT ASSOCIATED WITH THE UPPER LOW WILL REACH THE FORECAST AREA TODAY...CREATING LARGE LAPSE RATES AND LOWERING THE FREEZING LEVEL. GUSTY WINDS AND LARGE HAIL WILL BE A THREAT WITH ANY STRONGER STORMS...ESPECIALLY THIS AFTERNOON AND EVENING. THE UPPER LOW MOVES SOUTHEAST INTO SOUTH CAROLINA BY SUNDAY MORNING. EXPECT COVERAGE AND PROBABILITY OF PRECIPITATION TO DECREASE LATE TONIGHT. THERE WAS A BREAK IN THE CLOUD COVER AHEAD OF THE SHOWERS AND THUNDERSTORMS APPROACHING FROM THE WEST. FOG MAY DEVELOP EARLY THIS MORNING AS THE CLOUDS BRIEFLY CLEAR. WITH ALL THE PRECIPITATION EXPECTED TODAY...HAVE GONE ON THE COOL SIDE OF GUIDANCE. STAYED CLOSE TO A BLEND OF BIAS CORRECTED MAV/MET GUIDANCE FOR LOWS TONIGHT. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... AS OF 330 AM EST SATURDAY... SUNDAY MORNING WILL START OUT WITH THE UPPER LEVEL LOW PASSING JUST TO THE SOUTH OF OUR AREA...POSSIBLY CLIPPING OUR NORTH CAROLINA COUNTIES. IN ANY EVENT...EXPECT TO SEE GREATER COVERAGE OF SHOWER ACTIVITY NORTH OF INTERSTATE 81...AS A SLOT OF DRIER AIR WORKS ITS WAY IN SOUTH CLOSER TO THE LOW. COVERAGE WILL INCREASE FURTHER DURING THE AFTERNOON AS DAYTIME HEATING HELPS DESTABILIZE THE ATMOSPHERE...AND WILL NOT BE SURPRISED TO SEE A FEW THUNDERSTORMS DEVELOP BY LATE MORNING. WITH THE UPPER LOW PASSING SO CLOSE TO OUR AREA...BELIEVE THAT HAIL WILL BE A CONCERN IN THE STRONGER SHOWER AND THUNDERSTORM ACTIVITY...BUT EXPECT MOST HAIL TO BE IN THE PEA TO DIME SIZE RANGE WHERE IT OCCURS. SHOWER AND THUNDERSTORM ACTIVITY WILL DECREASE FROM WEST TO EAST BY LATE AFTERNOON AS THE UPPER LOW CONTINUES TO PUSH OFF THE ATLANTIC COAST...AND SHOWER ACTIVITY IS EXPECTED TO BE CONFINED TO THE MOUNTAINS...MAINLY IN SOUTHEAST WEST VIRGINIA BY LATE SUNDAY EVENING. DESPITE THE PASSAGE OF THE UPPER LOW...SUNDAY NIGHT TEMPERATURES WILL REMAIN MILD ACROSS OUR AREA...WITH OVERNIGHT LOWS RANGING FROM THE LOW TO MID 50S EAST...TO THE UPPER 40S WEST. IT WILL BE MONDAY MORNING WHEN WE SEE A CHANGE IN OUR WEATHER PATTERN AS ANOTHER COLD FRONT BRINGS A SHOT OF COOLER CANADIAN AIR INTO OUR AREA. MONDAY AFTERNOON TEMPERATURES ARE EXPECTED TO REMAIN MILD ACROSS OUR AREA...ALBEIT A LITTLE COOLER...HOWEVER IT WILL BE MONDAY NIGHT/TUESDAY MORNING TEMPERATURES THAT WILL BE OF CONCERN AS LOWS FALL INTO THE 30S ACROSS THE MOUNTAINS. BELIEVE THAT NEAR FREEZING TEMPERATURES WILL BE CONFINED TO GREENBRIER COUNTY IN SOUTHEAST WEST VIRGINIA...AS WELL AS THE ALLEGHANY HIGHLANDS IN VIRGINIA...LOCATIONS THAT HAVE NOT EXPERIENCED A START TO THE GROWING SEASON TO THE SAME EXTENT THAT HAS OCCURRED IN LOWER ELEVATIONS. THAT STATED...IT WOULD BE A GOOD IDEA TO CONSIDER PRECAUTIONS AGAINST THE COLD FOR ANY SENSITIVE VEGETATION WHICH HAS STARTED TO GROW IN YOUR AREA. HIGH PRESSURE WILL SLIDE EAST ON TUESDAY AFTERNOON...ALLOWING WINDS TO BECOME SOUTHERLY ACROSS OUR AREA. WITH A RIDGE OF UPPER LEVEL HIGH PRESSURE BUILDING IN FROM THE WEST LATE TUESDAY EVENING... OVERNIGHT TEMPERATURES WILL BE CONSIDERABLY WARMER...WITH LOWS EXPECTED TO RANGE FROM THE MID 40S IN THE WEST...TO THE UPPER 30S IN THE EAST. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 330 AM EDT SATURDAY... ON WEDNESDAY...A HIGH PRESSURE RIDGE WILL SLIDE EAST OFF THE COAST. SOUTHERLY FLOW RETURNS WITH MODERATING TEMPERATURES FOR THE REMAINDER OF THE WORK WEEK. LIGHT RAIN SHOWERS ARE POSSIBLE WEDNESDAY INTO THURSDAY AS A WEAK COOL FRONT PASSES OVER THE REGION. THIS RAIN WILL NOT BE ANY WHERE CLOSE IN INTENSITY TO THIS WEEKENDS RAIN EVENT. && .AVIATION /13Z SATURDAY THROUGH WEDNESDAY/... AS OF 230 AM EDT SATURDAY... EXPECT SEVERAL PERIODS OF SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH 06Z SUNDAY. CEILINGS AND VISIBILITIES WILL LOWER TO MVFR IN ASSOCIATION WITH THE SHOWERS AND STORMS. SOME OF THE STRONGER STORMS TODAY MAY PRODUCE GUSTY WINDS AND LARGE HAIL...MAINLY THIS AFTERNOON. COVERAGE OF PRECIPITATION WILL DIMINISH TONIGHT. LOW CLOUDS AND FOG WILL FILL IN OVERNIGHT WITH CEILINGS LOWERING TO IFR/MVFR LEVELS. HAVE LOWERED VISIBILITY TO LIFR AT LYH WITH MEDIUM CONFIDENCE. IF NORTHWEST SURFACE AND LOW LEVEL WINDS ARE A LITTLE STRONGER THAN EXPECTED THEN PROBABILITY OF LIFR OR IFR FOG WILL BE LOWER. SHRA WILL DEVELOP AGAIN ACROSS THE AREA SUN...BUT WITH CONSIDERABLE LESS INSTABILITY INDICATED AND A COLDER/MORE STABLE SFC ENVIRONMENT...DO NOT ANTICIPATE MUCH TSRA ACTIVITY SUN...JUST SHOWERS. DRIER WEATHER AND VFR CONDITIONS ARE EXPECTED BEHIND THIS WEATHER SYSTEM SUNDAY NIGHT THROUGH TUESDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...NF LONG TERM...RCS AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
742 AM EDT SAT MAR 24 2012 .SYNOPSIS... LOW PRESSURE OVER THE OHIO VALLEY WILL MOVE EAST THEN SOUTHEAST TODAY AND TONIGHT. BY SUNDAY NIGHT THE LOW WILL BE OFF THE CAROLINA COAST. HIGH PRESSURE WILL BUILD OVER THE REGION MONDAY AND TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 410 AM EDT SATURDAY... EXPECTING SEVERAL BANDS OF SHOWERS AND THUNDERSTORMS TODAY AND TONIGHT. FIRST AREA WAS OVER THE CENTRAL AND EASTERN COUNTY WARNING AREA EARLY THIS MORNING AND WAS MOVING NORTHEAST AROUND 20 MPH. THE NEXT BAND EXTENDS FROM OHIO INTO EASTERN TENNESSEE. LOCAL WRF AND HRRR BRING THIS BAND INTO THE WESTERN COUNTY WARNING AREA BY 8AM. AS THE UPPER LOW MOVES EAST THIS MOVING SO WILL THE SHOWERS AND THUNDERSTORMS. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE FORECAST AREA THIS AFTERNOON. COLDER AIR ALOFT ASSOCIATED WITH THE UPPER LOW WILL REACH THE FORECAST AREA TODAY...CREATING LARGE LAPSE RATES AND LOWERING THE FREEZING LEVEL. GUSTY WINDS AND LARGE HAIL WILL BE A THREAT WITH ANY STRONGER STORMS...ESPECIALLY THIS AFTERNOON AND EVENING. THE UPPER LOW MOVES SOUTHEAST INTO SOUTH CAROLINA BY SUNDAY MORNING. EXPECT COVERAGE AND PROBABILITY OF PRECIPITATION TO DECREASE LATE TONIGHT. THERE WAS A BREAK IN THE CLOUD COVER AHEAD OF THE SHOWERS AND THUNDERSTORMS APPROACHING FROM THE WEST. FOG MAY DEVELOP EARLY THIS MORNING AS THE CLOUDS BRIEFLY CLEAR. WITH ALL THE PRECIPITATION EXPECTED TODAY...HAVE GONE ON THE COOL SIDE OF GUIDANCE. STAYED CLOSE TO A BLEND OF BIAS CORRECTED MAV/MET GUIDANCE FOR LOWS TONIGHT. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... AS OF 330 AM EST SATURDAY... SUNDAY MORNING WILL START OUT WITH THE UPPER LEVEL LOW PASSING JUST TO THE SOUTH OF OUR AREA...POSSIBLY CLIPPING OUR NORTH CAROLINA COUNTIES. IN ANY EVENT...EXPECT TO SEE GREATER COVERAGE OF SHOWER ACTIVITY NORTH OF INTERSTATE 81...AS A SLOT OF DRIER AIR WORKS ITS WAY IN SOUTH CLOSER TO THE LOW. COVERAGE WILL INCREASE FURTHER DURING THE AFTERNOON AS DAYTIME HEATING HELPS DESTABILIZE THE ATMOSPHERE...AND WILL NOT BE SURPRISED TO SEE A FEW THUNDERSTORMS DEVELOP BY LATE MORNING. WITH THE UPPER LOW PASSING SO CLOSE TO OUR AREA...BELIEVE THAT HAIL WILL BE A CONCERN IN THE STRONGER SHOWER AND THUNDERSTORM ACTIVITY...BUT EXPECT MOST HAIL TO BE IN THE PEA TO DIME SIZE RANGE WHERE IT OCCURS. SHOWER AND THUNDERSTORM ACTIVITY WILL DECREASE FROM WEST TO EAST BY LATE AFTERNOON AS THE UPPER LOW CONTINUES TO PUSH OFF THE ATLANTIC COAST...AND SHOWER ACTIVITY IS EXPECTED TO BE CONFINED TO THE MOUNTAINS...MAINLY IN SOUTHEAST WEST VIRGINIA BY LATE SUNDAY EVENING. DESPITE THE PASSAGE OF THE UPPER LOW...SUNDAY NIGHT TEMPERATURES WILL REMAIN MILD ACROSS OUR AREA...WITH OVERNIGHT LOWS RANGING FROM THE LOW TO MID 50S EAST...TO THE UPPER 40S WEST. IT WILL BE MONDAY MORNING WHEN WE SEE A CHANGE IN OUR WEATHER PATTERN AS ANOTHER COLD FRONT BRINGS A SHOT OF COOLER CANADIAN AIR INTO OUR AREA. MONDAY AFTERNOON TEMPERATURES ARE EXPECTED TO REMAIN MILD ACROSS OUR AREA...ALBEIT A LITTLE COOLER...HOWEVER IT WILL BE MONDAY NIGHT/TUESDAY MORNING TEMPERATURES THAT WILL BE OF CONCERN AS LOWS FALL INTO THE 30S ACROSS THE MOUNTAINS. BELIEVE THAT NEAR FREEZING TEMPERATURES WILL BE CONFINED TO GREENBRIER COUNTY IN SOUTHEAST WEST VIRGINIA...AS WELL AS THE ALLEGHANY HIGHLANDS IN VIRGINIA...LOCATIONS THAT HAVE NOT EXPERIENCED A START TO THE GROWING SEASON TO THE SAME EXTENT THAT HAS OCCURRED IN LOWER ELEVATIONS. THAT STATED...IT WOULD BE A GOOD IDEA TO CONSIDER PRECAUTIONS AGAINST THE COLD FOR ANY SENSITIVE VEGETATION WHICH HAS STARTED TO GROW IN YOUR AREA. HIGH PRESSURE WILL SLIDE EAST ON TUESDAY AFTERNOON...ALLOWING WINDS TO BECOME SOUTHERLY ACROSS OUR AREA. WITH A RIDGE OF UPPER LEVEL HIGH PRESSURE BUILDING IN FROM THE WEST LATE TUESDAY EVENING... OVERNIGHT TEMPERATURES WILL BE CONSIDERABLY WARMER...WITH LOWS EXPECTED TO RANGE FROM THE MID 40S IN THE WEST...TO THE UPPER 30S IN THE EAST. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 330 AM EDT SATURDAY... ON WEDNESDAY...A HIGH PRESSURE RIDGE WILL SLIDE EAST OFF THE COAST. SOUTHERLY FLOW RETURNS WITH MODERATING TEMPERATURES FOR THE REMAINDER OF THE WORK WEEK. LIGHT RAIN SHOWERS ARE POSSIBLE WEDNESDAY INTO THURSDAY AS A WEAK COOL FRONT PASSES OVER THE REGION. THIS RAIN WILL NOT BE ANY WHERE CLOSE IN INTENSITY TO THIS WEEKENDS RAIN EVENT. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... AS OF 230 AM EDT SATURDAY... EXPECT SEVERAL PERIODS OF SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH 06Z SUNDAY. CEILINGS AND VISIBILITIES WILL LOWER TO MVFR IN ASSOCIATION WITH THE SHOWERS AND STORMS. SOME OF THE STRONGER STORMS TODAY MAY PRODUCE GUSTY WINDS AND LARGE HAIL...MAINLY THIS AFTERNOON. COVERAGE OF PRECIPITATION WILL DIMINISH TONIGHT. LOW CLOUDS AND FOG WILL FILL IN OVERNIGHT WITH CEILINGS LOWERING TO IFR/MVFR LEVELS. HAVE LOWERED VISIBILITY TO LIFR AT LYH WITH MEDIUM CONFIDENCE. IF NORTHWEST SURFACE AND LOW LEVEL WINDS ARE A LITTLE STRONGER THAN EXPECTED THEN PROBABILITY OF LIFR OR IFR FOG WILL BE LOWER. SHRA WILL DEVELOP AGAIN ACROSS THE AREA SUN...BUT WITH CONSIDERABLE LESS INSTABILITY INDICATED AND A COLDER/MORE STABLE SFC ENVIRONMENT...DO NOT ANTICIPATE MUCH TSRA ACTIVITY SUN...JUST SHOWERS. DRIER WEATHER AND VFR CONDITIONS ARE EXPECTED BEHIND THIS WEATHER SYSTEM SUNDAY NIGHT THROUGH TUESDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...NF LONG TERM...RCS AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
427 AM EDT SAT MAR 24 2012 .SYNOPSIS... LOW PRESSURE OVER THE OHIO VALLEY WILL MOVE EAST THEN SOUTHEAST TODAY AND TONIGHT. BY SUNDAY NIGHT THE LOW WILL BE OFF THE CAROLINA COAST. HIGH PRESSURE WILL BUILD OVER THE REGION MONDAY AND TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 410 AM EDT SATURDAY... EXPECTING SEVERAL BANDS OF SHOWERS AND THUNDERSTORMS TODAY AND TONIGHT. FIRST AREA WAS OVER THE CENTRAL AND EASTERN COUNTY WARNING AREA EARLY THIS MORNING AND WAS MOVING NORTHEAST AROUND 20 MPH. THE NEXT BAND EXTENDS FROM OHIO INTO EASTERN TENNESSEE. LOCAL WRF AND HRRR BRING THIS BAND INTO THE WESTERN COUNTY WARNING AREA BY 8AM. AS THE UPPER LOW MOVES EAST THIS MOVING SO WILL THE SHOWERS AND THUNDERSTORMS. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE FORECAST AREA THIS AFTERNOON. COLDER AIR ALOFT ASSOCIATED WITH THE UPPER LOW WILL REACH THE FORECAST AREA TODAY...CREATING LARGE LAPSE RATES AND LOWERING THE FREEZING LEVEL. GUSTY WINDS AND LARGE HAIL WILL BE A THREAT WITH ANY STRONGER STORMS...ESPECIALLY THIS AFTERNOON AND EVENING. THE UPPER LOW MOVES SOUTHEAST INTO SOUTH CAROLINA BY SUNDAY MORNING. EXPECT COVERAGE AND PROBABILITY OF PRECIPITATION TO DECREASE LATE TONIGHT. THERE WAS A BREAK IN THE CLOUD COVER AHEAD OF THE SHOWERS AND THUNDERSTORMS APPROACHING FROM THE WEST. FOG MAY DEVELOP EARLY THIS MORNING AS THE CLOUDS BRIEFLY CLEAR. WITH ALL THE PRECIPITATION EXPECTED TODAY...HAVE GONE ON THE COOL SIDE OF GUIDANCE. STAYED CLOSE TO A BLEND OF BIAS CORRECTED MAV/MET GUIDANCE FOR LOWS TONIGHT. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... AS OF 330 AM EST SATURDAY... SUNDAY MORNING WILL START OUT WITH THE UPPER LEVEL LOW PASSING JUST TO THE SOUTH OF OUR AREA...POSSIBLY CLIPPING OUR NORTH CAROLINA COUNTIES. IN ANY EVENT...EXPECT TO SEE GREATER COVERAGE OF SHOWER ACTIVITY NORTH OF INTERSTATE 81...AS A SLOT OF DRIER AIR WORKS ITS WAY IN SOUTH CLOSER TO THE LOW. COVERAGE WILL INCREASE FURTHER DURING THE AFTERNOON AS DAYTIME HEATING HELPS DESTABILIZE THE ATMOSPHERE...AND WILL NOT BE SURPRISED TO SEE A FEW THUNDERSTORMS DEVELOP BY LATE MORNING. WITH THE UPPER LOW PASSING SO CLOSE TO OUR AREA...BELIEVE THAT HAIL WILL BE A CONCERN IN THE STRONGER SHOWER AND THUNDERSTORM ACTIVITY...BUT EXPECT MOST HAIL TO BE IN THE PEA TO DIME SIZE RANGE WHERE IT OCCURS. SHOWER AND THUNDERSTORM ACTIVITY WILL DECREASE FROM WEST TO EAST BY LATE AFTERNOON AS THE UPPER LOW CONTINUES TO PUSH OFF THE ATLANTIC COAST...AND SHOWER ACTIVITY IS EXPECTED TO BE CONFINED TO THE MOUNTAINS...MAINLY IN SOUTHEAST WEST VIRGINIA BY LATE SUNDAY EVENING. DESPITE THE PASSAGE OF THE UPPER LOW...SUNDAY NIGHT TEMPERATURES WILL REMAIN MILD ACROSS OUR AREA...WITH OVERNIGHT LOWS RANGING FROM THE LOW TO MID 50S EAST...TO THE UPPER 40S WEST. IT WILL BE MONDAY MORNING WHEN WE SEE A CHANGE IN OUR WEATHER PATTERN AS ANOTHER COLD FRONT BRINGS A SHOT OF COOLER CANADIAN AIR INTO OUR AREA. MONDAY AFTERNOON TEMPERATURES ARE EXPECTED TO REMAIN MILD ACROSS OUR AREA...ALBEIT A LITTLE COOLER...HOWEVER IT WILL BE MONDAY NIGHT/TUESDAY MORNING TEMPERATURES THAT WILL BE OF CONCERN AS LOWS FALL INTO THE 30S ACROSS THE MOUNTAINS. BELIEVE THAT NEAR FREEZING TEMPERATURES WILL BE CONFINED TO GREENBRIER COUNTY IN SOUTHEAST WEST VIRGINIA...AS WELL AS THE ALLEGHANY HIGHLANDS IN VIRGINIA...LOCATIONS THAT HAVE NOT EXPERIENCED A START TO THE GROWING SEASON TO THE SAME EXTENT THAT HAS OCCURRED IN LOWER ELEVATIONS. THAT STATED...IT WOULD BE A GOOD IDEA TO CONSIDER PRECAUTIONS AGAINST THE COLD FOR ANY SENSITIVE VEGETATION WHICH HAS STARTED TO GROW IN YOUR AREA. HIGH PRESSURE WILL SLIDE EAST ON TUESDAY AFTERNOON...ALLOWING WINDS TO BECOME SOUTHERLY ACROSS OUR AREA. WITH A RIDGE OF UPPER LEVEL HIGH PRESSURE BUILDING IN FROM THE WEST LATE TUESDAY EVENING... OVERNIGHT TEMPERATURES WILL BE CONSIDERABLY WARMER...WITH LOWS EXPECTED TO RANGE FROM THE MID 40S IN THE WEST...TO THE UPPER 30S IN THE EAST. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 330 AM EDT SATURDAY... ON WEDNESDAY...A HIGH PRESSURE RIDGE WILL SLIDE EAST OFF THE COAST. SOUTHERLY FLOW RETURNS WITH MODERATING TEMPERATURES FOR THE REMAINDER OF THE WORK WEEK. LIGHT RAIN SHOWERS ARE POSSIBLE WEDNESDAY INTO THURSDAY AS A WEAK COOL FRONT PASSES OVER THE REGION. THIS RAIN WILL NOT BE ANY WHERE CLOSE IN INTENSITY TO THIS WEEKENDS RAIN EVENT. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... AS OF 230 AM EDT SATURDAY... EXPECT SEVERAL PERIODS OF SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH 06Z SUNDAY. CEILINGS AND VISIBILITIES WILL LOWER TO MVFR IN ASSOCIATION WITH THE SHOWERS AND STORMS. SOME OF THE STRONGER STORMS TODAY MAY PRODUCE GUSTY WINDS AND LARGE HAIL. MODERATE CONFIDENCE...SUPPORTED BY THE LOCAL WRF AND THE 04Z HRRR RUN...THAT THUNDERSTORMS IN EASTERN KENTUCKY WILL REACH BLF AND LWB BETWEEN 10Z-12Z THIS MORNING. SHRA WILL CONTINUE TO DEVELOP ACROSS THE AREA SUN...BUT WITH CONSIDERABLE LESS INSTABILITY INDICATED AND A COLDER/MORE STABLE SFC ENVIRONMENT...DO NOT ANTICIPATE MUCH TSRA ACTIVITY SUN...JUST SHRA. DRIER WEATHER AND VFR CONDITIONS ARE EXPECTED BEHIND THIS WEATHER SYSTEM SUNDAY NIGHT THROUGH TUESDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...NF LONG TERM...RCS/NF AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
236 AM EDT SAT MAR 24 2012 .SYNOPSIS... A LOW PRESSURE SYSTEM WILL TRACK EAST OUT OF THE MID MISSISSIPPI VALLEY TONIGHT...THEN SOUTHEAST ACROSS THE TENNESSEE VALLEY ON SATURDAY. BY MONDAY...THE SYSTEM WILL BE OFF THE EAST COAST. && .NEAR TERM /THROUGH TODAY/... AS OF 1030 PM EDT FRIDAY... CONTINUED WITH CATEGORICAL/DEFINITE POPS THROUGH 06Z ACROSS THE CWA...THEN DECREASED TO CHC POPS AFT 06Z AS FIRST WAVE OF PVA ASSOCIATED WITH LEADING CIRCULATION FROM APPROACHING CLOSED LOW MOVES ACROSS THE CWA FROM WEST TO EAST. INTENSITY OF ACTIVITY HAS CONTINUED TO DECREASE SINCE SUNSET AND THE ONLY AREA NOW EXHIBITING ANY LIGHTNING IS NEAR DAN. CONFINED TSRA THREAT TO EC/SE PARTS OF THE CWA...THEN ENDED BY 06Z. THUNDERSTORMS EXPECTED TO DEVELOP SAT AFTERNOON WITH DRY SLOT DURING THE FIRST HALF OF THE DAY EXPECTED TO PROVIDE AMPLE INSOLATION...WHICH COMBINED WITH COLDER TEMPS ALOFT SPREADING ACROSS THE AREA WILL RESULT IN STEEP LAPSE RATES. WET BULB ZERO HEIGHTS WILL ALSO LOWER. MAIN THREAT WILL BE QUARTER-SIZED HAIL. STORMS COULD ALSO BE EFFICIENT LIGHTNING PRODUCERS. SPC CURRENTLY HAS MUCH OF THE SE PART OF THE CWA IN A SLIGHT RISK FOR SAT AFTERNOON. TEMP AND SKY GRIDS APPEAR TO BE ON TRACK AT THIS TIME. AS OF 300 PM EDT FRIDAY... WSR-88D KFCX SHOWED ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING IN THE WARM UNSTABLE AIR THIS AFTERNOON ESPECIALLY WEST OF I77. SHOWERS AND THUNDERSTORMS WILL INCREASE IN NUMBERS AND COVERAGE THIS EVENING INTO TONIGHT...AS THE DEEP CLOSED LOW ALOFT AND TRAILING FRONTAL BOUNDARY APPROACHES. ANY TRAINING OF SHOWERS AND THUNDERSTORMS WITH PRECIPITABLE WATER VALUES BETWEEN 1.25 AND 1.50 INCHES COULD PRODUCE LOCAL FLOODING CONCERNS. TRIED TO INSERT MORE OF A DIURNAL TREND FOR THE THUNDERSTORM POTENTIAL AND TRIMMED THUNDER MENTION OVERNIGHT WITH THE LOSS OF THE HEATING. PLAYED LOW TEMPERATURES OVERNIGHT CLOSE TO THE MILD ADJMET VALUES WITH READINGS FROM THE MID 50S TO AROUND 60 DEGREES IN THE SOUTHEAST. ON SATURDAY...THE UPPER-LEVEL LOW WILL MOVE EASTWARD ACROSS THE OHIO VALLEY IN OUR REGION. AS SFC TEMPERATURES WARM BENEATH THE UPPER-LEVEL LOW...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL DEVELOP. SPC HAS PLACED EASTERN PORTIONS OF OUR CWA UNDER A SLIGHT RISK FOR SEVERE THUNDERSTORMS ON SATURDAY. DUE TO COLD AIR ALOFT...STEEP MID-LEVEL LAPSE RATES AND LARGE-SCALE ASCENT ASSOCIATED WITH THE UPPER-LEVEL LOW...SOME OF THE CONVECTION COULD CONTAIN HAIL DURING THE AFTERNOON. HEAVY RAINFALL IS ALSO POSSIBLE ON SATURDAY WITH THE THUNDERSTORMS. HIGHS ON SATURDAY WILL RANGE FROM THE LOWER 60S IN THE MOUNTAINS TO THE MID 70S IN THE PIEDMONT. && .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... AS OF 222 PM EDT FRIDAY... THE UPPER LEVEL LOW THAT HAS BEEN SPINNING ACROSS THE USA MOST OF THIS WEEK WILL PLAGUE THE EAST COAST OVER THE WEEKEND. SATURDAY NIGHT...THE LOW WILL BE CENTERED IN THE TENNESSEE VALLEY THEN CROSS THE SOUTHERN APPALACHIANS AND OVER THE CAROLINAS BY SUNDAY MORNING. MODELS DISPLAYING A SURFACE LOW DEVELOPING ALONG THE FRONT IN THE VA/NC COASTAL PIEDMONT SATURDAY NIGHT. EVENTUALLY...THIS TWO SYSTEMS WILL BECOME AN OCCLUDED LOW OVER THE OUTER BANKS SUNDAY...SLOWING DOWN THE EXIT OF SHOWERS UNTIL SUNDAY EVENING. RAIN SHOWERS WILL NOT BE CONTINUOUS SATURDAY NIGHT. BANDS OF SHOWERS WILL PASS OVER THE AREA THEN A BRIEF DRY PERIOD BEFORE THE NEXT BAND COMES IN. EACH BAND OF SHOWERS COULD PRODUCE UP TO A QUARTER OF AN INCH OF RAIN. THE DRYING TIME BETWEEN BANDS AND INCREASE VEGETATION SHOULD TAKE CARE OF MOST OF THE RUNOFF. HOWEVER...IF CONVECTION IS STRONGER AND RAINFALL RATES ARE HIGHER...LOCALIZED FLASH FLOODING IS POSSIBLE SATURDAY NIGHT. AREAL FLOODING BECOMES AN ISSUE ON SUNDAY AS THE LOW TRACKS OVER THE OUTER BANKS AND OUT TO SEA. THE DEFORMATION ZONE WILL PIVOT OVER THE AREA...CROSSING THE MOUNTAINS IN THE MORNING...THEN EAST OF THE BLUE RIDGE SUNDAY AFTERNOON/EVENING. RAIN FROM THIS DEFORMATION ZONE WILL BE CONTINUOUS WITH AMOUNTS FROM A QUARTER TO A HALF OF AN INCH. RAIN FINALLY MOVES EAST OF THE AREA SUNDAY EVENING. BRIEF UPSLOPE SHOWERS/DRIZZLE ON WESTERN SLOPES SUNDAY NIGHT...THEN AN EXTENDED DRY PERIOD PERSIST INTO MID WEEK. RAIN WILL HELP COOL TEMPERATURES CLOSER TO SEASONAL LEVELS SUNDAY...HOWEVER....THEY WILL STILL BE ABOVE NORMAL. UNDERCUT THE COLDEST GUIDANCE (METMOS) WITH RAIN AND THE UPPER LEVEL LOW TO OUR SOUTH SUNDAY. COOLER AIR ARRIVES MONDAY...BUT TEMPERATURES WILL STILL RUN ABOUT 10F ABOVE NORMAL. OVERNIGHTS WILL REMAIN MUGGY UNTIL THE SYSTEM MOVES OUT TO SEA EARLY MONDAY MORNING. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 232 PM EDT FRIDAY... SURFACE HIGH PRESSURE WILL MOVE FROM NEW ENGLAND TO THE MID ATLANTIC REGION TUESDAY. THIS RIDGE WILL KNOCK TEMPERATURES DOWN TO NEAR NORMAL. ON WEDNESDAY...THE RIDGE SLIDES OFF THE COAST. SOUTHERLY FLOW RETURNS WITH MODERATING TEMPERATURES FOR THE REMAINDER OF THE WORK WEEK. LIGHT RAIN SHOWERS ARE POSSIBLE WEDNESDAY INTO THURSDAY AS A WEAK COOL FRONT PASSES OVER THE REGION. THIS RAIN WILL NOT BE ANY WHERE CLOSE TO THIS WEEKENDS RAIN EVENT. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... AS OF 230 AM EDT SATURDAY... EXPECT SEVERAL PERIODS OF SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH 06Z SUNDAY. CEILINGS AND VISIBILITIES WILL LOWER TO MVFR IN ASSOCIATION WITH THE SHOWERS AND STORMS. SOME OF THE STRONGER STORMS TODAY MAY PRODUCE GUSTY WINDS AND LARGE HAIL. MODERATE CONFIDENCE...SUPPORTED BY THE LOCAL WRF AND THE 04Z HRRR RUN...THAT THUNDERSTORMS IN EASTERN KENTUCKY WILL REACH BLF AND LWB BETWEEN 10Z-12Z THIS MORNING. SHRA WILL CONTINUE TO DEVELOP ACROSS THE AREA SUN...BUT WITH CONSIDERABLE LESS INSTABILITY INDICATED AND A COLDER/MORE STABLE SFC ENVIRONMENT...DO NOT ANTICIPATE MUCH TSRA ACTIVITY SUN...JUST SHRA. DRIER WEATHER AND VFR CONDITIONS ARE EXPECTED BEHIND THIS WEATHER SYSTEM SUNDAY NIGHT THROUGH TUESDAY. && .CLIMATE... RECORD HIGH TEMPS FOR FRIDAY... 3/23 ROANOKE 82 IN 2007 LYNCHBURG 91 IN 2007 DANVILLE 86 IN 1966 BLUEFIELD 77 IN 2007 BLACKSBURG 80 IN 1966 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...KK SHORT TERM...RCS LONG TERM...RCS AVIATION...AMS/KK CLIMATE...AMS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
940 PM CDT SUN MAR 25 2012 .SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT 940 PM CDT SUN MAR 25 2012 MADE SOME ADJUSTMENTS TO THE FORECAST FOR TONIGHT WITH SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS MN IN ON THE LEADING EDGE OF THE MOISTURE TRANSPORT AND IN THE HEART OF THE THETA-E CONVERGENCE AREA. 00Z NAM HAS A BETTER GRASP ON WHAT IS OCCURRING...ALTHOUGH IT IS STILL JUST A TAD SLOW. HRRR IR ALSO TOO SLOW BUT INDICATING A SIMILAR TREND OF CARRYING THIS ACTION INTO THE FORECAST AREA OVERNIGHT. THE OTHER CONCERN REMAINS WITH THE POTENTIAL FOR FREEZING TEMPERATURES OVER NORTH CENTRAL WISCONSIN. THE CLOUD COVER IS THICKER SOONER AND FURTHER NORTH THAN EARLIER ANTICIPATED...SO NOT CONFIDENT THAT THE TEMPERATURES WILL DROP BELOW THE FREEZING MARK... AT LEAST FOR ANY SIGNIFICANT AMOUNT OF TIME. BUT...WITH DRY AIR STILL ADVECTING IN FROM THE NORTH...COULD STILL SEE ENOUGH OF A DROP TO GET TO THE FREEZING MARK. TEMPERATURES ARE ALREADY IN THE MID 30S NOT TOO FAR NORTH OF TAYLOR COUNTY...WITH READINGS BELOW FREEZING OVER FAR NORTHERN WI. WILL KEEP THE FREEZE WARNING GOING FOR NOW. AN EVEN BETTER CHANCE FOR RAIN WILL BE MONDAY NIGHT AS THE LOW LEVEL JET/MOISTURE TRANSPORT FOCUSES ACROSS MN...SHIFTING ACROSS NORTHERN MN/WI WITH THE THE FRONTOGENETIC AND THERMODYNAMIC LIFT. THE MAIN RAIN THREAT MONDAY-MONDAY NIGHT WILL BE TO THE WEST AND NORTH. A TIGHT PRESSURE GRADIENT AHEAD OF AN APPROACHING LOW PRESSURE AREA WILL MAKE FOR WINDY CONDITIONS. GUSTS SHOULD CONTINUE THROUGH THE NIGHT DESPITE AN INVERSION NEAR 900 MB. BUFKIT SOUNDINGS POINT TO THE POTENTIAL OF MIXING DOWN 30-35 KTS DURING THIS TIME FRAME. THE SURFACE LOW WILL TRACK FROM THE NORTHERN PLAINS TO JUST NORTH OF LAKE SUPERIOR BY 06Z WED. THIS WILL DRAG A NORTH-SOUTH RUNNING COLD FRONT TO THE MISSISSIPPI RIVER BY 18Z MON...MOVING INTO EASTERN WI BY MON EVENING. GOOD MOISTURE RETURN AHEAD OF THE FRONT...BUT FRONTOGENETIC FORCING IS FAIRLY WEAK. THE BULK OF THE INSTABILITY IS ALSO SOUTH OF THE FORECAST AREA...WITH PERHAPS 250-500 J/KG OF MUCAPE ACROSS NORTHEAST IA/SOUTHWEST WI. 0-3 KM SHEAR REMAINS HEFTY FROM THE WEST...AROUND 40 KTS OR SO. STILL EXPECT SOME SHOWERS AND STORMS TO DEVELOP AHEAD OF THIS BOUNDARY ON TUE...BUT THE BETTER THREAT FOR STORMS...INCLUDING STRONG/SEVERE POTENTIAL...WILL PROBABLY CONFINE ITSELF TO EASTERN IA/NORTHERN-CENTRAL ILL TUE AFTERNOON-EVENING. .LONG TERM...THURSDAY THROUGH SUNDAY 245 PM CDT SUN MAR 25 2012 MAIN FOCUS FOR THE LONG TERM ARE PRECIPITATION CHANCES THURSDAY NIGHT INTO FRIDAY...AND MODEL DIFFERENCES FOR UPCOMING WEEKEND. DECENT MODEL AGREEMENT BETWEEN 25.12Z GFS...GEM AND ECMWF DEPICTING UPPER LEVEL TROUGHS ACROSS THE WEST AND EAST COAST OF NORTH AMERICA AND RIDING IN BETWEEN. AT THE SURFACE...HIGH PRESSURE SITUATED ACROSS ONTARIO WILL BEGIN TO BREAK DOWN AS A WEAK SHORTWAVE ENTERS THE NORTHERN PLAINS. 850MB MOISTURE TRANSPORT RETURN ON THE BACKSIDE OF THE HIGH NOT THAT IMPRESSIVE AS THERE IS NO REAL TAP OF GULF OF MEXICO MOISTURE. THE 25.12Z GEM IS A BIT MORE ROBUST WITH QPF...BUT THE BEST FORCING IS SPLIT BETWEEN THE NORTHERN SHORTWAVE ACROSS NORTHERN MINNESOTA/WISCONSIN AND THE SOUTHERN RETURN FLOW MOISTURE...KEEPING THE CWA MOSTLY DRY. FOR NOW...THE BEST CHANCES FOR SHOWERS APPEAR TO BE MAINLY ACROSS IOWA...AND EXTREME SOUTHERN WISCONSIN. BEYOND FRIDAY...MUCH DISAGREEMENT EXISTS BETWEEN THE OPERATIONAL MODELS THIS UPCOMING WEEKEND GOING INTO EARLY NEXT WEEK. 25.12Z GFS CARVES OUT A DEEP 500MB TROUGH OVER THE ROCKIES WITH STRONG RIDGING ACROSS THE CENTRAL PLAINS...RESULTING IN 850MB TEMPS OF +10C ACROSS WESTERN WISCONSIN TO +15C FURTHER WEST ACROSS SOUTH DAKOTA. MEANWHILE...THE ECMWF IS NEARLY OUT OF PHASE WITH THE GFS...AND DEPICTS A CUT OFF LOW ACROSS THE CENTRAL PLAINS SUNDAY...FOLLOWED BY A BRIEF PERIOD OF RIDGING BEFORE A QUICK MOVING SHORTWAVE DIVES SOUTH MONDAY. THIS SCENARIO WOULD LEAD TO MUCH COOLER TEMPERATURES...WITH 850MB TEMPS OF ONLY +5C SUNDAY TO AROUND 0C MONDAY. AT THIS TIME...GIVEN THE LACK OF CONSISTENCY BETWEEN MODELS AND POOR RUN-TO-RUN SOLUTIONS BEYOND FRIDAY...WILL SIDE WITH THE MODEL CONSENSUS SOLUTION FOR NOW. && .AVIATION...THROUGH 18Z MONDAY 630 PM CDT SUN MAR 25 2012 MID CLOUD IS DEVELOPING ACROSS SOUTHERN MN AS ISENTROPIC UPGLIDE AND WARM ADVECTION FOCUS AHEAD OF THE NEXT SHORT WAVE TROUGH. MODEL SOLUTIONS ALL INDICATE A DEEPENING OF THE MOIST LAYER AND THUS A THICKENING OF THE CLOUD COVER THROUGH THE NIGHT. COULD BE ENOUGH FORCING FOR SOME -RA/-SHRA BUT HARD TO PIN DOWN EXACT TIMING. WINDS WILL BECOME EASTERLY LATE THIS EVENING AND EVENTUALLY WILL TURN SOUTHEAST OVERNIGHT. WITH A TIGHTENING GRADIENT...EXPECT SPEEDS TO INCREASE AS WELL. ANTICIPATE SOME GUSTY CONDITIONS... ESPECIALLY AT THE MORE OPEN KRST LOCATION. && .ARX WATCHES/WARNINGS/ADVISORIES... 940 PM CDT SUN MAR 25 2012 WI...FREEZE WARNING FROM 2 AM TO 8 AM CDT MONDAY FOR WIZ017. MN...NONE. IA...NONE. && $$ SHORT TERM...MW/RIECK LONG TERM....ZT AVIATION.....MW
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
641 PM CDT SUN MAR 25 2012 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND MONDAY. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE COLD FRONT DROPPING INTO NORTHERN ILLINOIS EARLY THIS AFTERNOON WHILE CANADIAN HIGH PRESSURE IS BUILDING SOUTH INTO THE NORTHERN MISSISSIPPI VALLEY. LOW STRATO-CU DISSIPATED RATHER QUICKLY EARLIER TODAY AS MIXING INTO DRIER AIR OVERWHELMED THE SHALLOW COOL AND MOIST AIRMASS. STILL SOME LINGERING CU OVER EAST-CENTRAL WISCONSIN...THOUGH TRENDS SUPPORT IT DISSIPATING AS WELL OVER THE NEXT COUPLE HOURS. UPSTREAM IS PRETTY QUIET...WITH ONLY MID AND HIGH CLOUDS PUSHING ACROSS THE DAKOTAS. AS HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION TONIGHT...LOW TEMPS AND HEADLINES ARE THE MAIN FORECAST CONCERNS. TONIGHT...LAST NIGHTS COLD FRONT WILL CONTINUE TO SAG SOUTH TOWARDS THE OHIO VALLEY WHILE CANADIAN HIGH PRESSURE WILL BUILD INTO SOUTHERN ONTARIO AND THE WESTERN GREAT LAKES. THIS INCOMING AIRMASS FROM CANADA IS QUITE DRY AND WILL DROP PWATS TO UNDER A QUARTER OF AN INCH. THOUGH AIRMASS IS VERY DRY...NOT IDEAL RADIATIONAL COOLING CONDITIONS WILL BE IN PLACE FOR TONIGHT. WILL HAVE SCT-BKN MID AND HIGH CLOUDS ARRIVE FROM THE NORTHERN PLAINS INTO MUCH OF CENTRAL AND EAST-CENTRAL WISCONSIN BY LATE THIS EVENING. THE PRESSURE GRADIENT WILL ALSO REMAIN FAIRLY TIGHT OVER NE WISCONSIN WHERE NE WINDS FUNNELED DOWN THE BAY...AND ALSO OFF LAKE MICHIGAN WILL KEEP THE BL RATHER BREEZY. NORTH-CENTRAL WISCONSIN WILL SEE 1000-850MB WINDS AROUND 15 KTS...WHICH IS RIGHT ON THE EDGE FOR DECOUPLING. AM GOING TO LEAN TOWARDS DECOUPLING OCCURRING...DUE TO SANDY SOIL EFFECTS AND CLOUDS SHIFTING SOUTH THROUGH THE NIGHT. AS A RESULT...MID TWENTY LOWS SEEM PERFECTLY REASONABLE UP NORTH...AND SEE LITTLE REASON TO ADJUST HEADLINES. DID RAISE LOWS A DEGREE OR TWO OVER CENTRAL AND EAST-CENTRAL WISCONSIN BECAUSE OF CLOUDS AND WIND. LOWS IN THE LOWER TO MIDDLE 30S HERE. MONDAY...MID-LEVEL CLOUDS WILL STALL OVER SW WISCONSIN TOMORROW MORNING AND WILL RETURN NE IN THE AFTERNOON WHEN THE COLD FRONT STARTS RETURNING NORTH. NE WISCONSIN WILL SEE A MOSTLY SUNNY DAY...BUT CENTRAL AND NORTH-CENTRAL WISCONSIN WILL SEE A GRADUAL INCREASE IN CLOUDS. HIGHS RANGING FROM THE LOWER TO MIDDLE 40S EVERYWHERE. .LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY. THE WEATHER WILL BE MORE SEASONABLE THAN THE LAST TWO WEEKS WITH FLATTER ALMOST ZONAL FLOW OVER MUCH OF THE REGION THROUGH FRIDAY. SIGNIFICANT MODEL DIFFERENCES FOR NEXT SATURDAY AND SUNDAY WITH HIGH AMPLITUDE FLOW EXPECTED NEXT WEEK. UPPER TROUGH LIFTING NORTHEAST THROUGH THE NORTHERN PLAINS MONDAY NIGHT WILL BRING SHOWERS AND ELEVATED THUNDERSTORMS MONDAY NIGHT AND EARLY TUESDAY. THERE MIGHT BE ENOUGH COLD AIR FOR SLEET TO BE MIXED IN ACROSS THE NORTHERN PART OF THE FORECAST AREA. A COLD FRONT MOVES THROUGH TUESDAY AFTERNOON OR EVENING ACCOMPANIED BY STRONG WINDS IN THE LOW LEVELS...LOTS OF SHEAR AND DECENT UPPER SUPPORT. MOISTURE SHOULD BE LACKING THOUGH WHICH WILL LIMIT INSTABILITY. THERE IS SOME CHANCE OF SEVERE THUNDERSTORMS IF MOISTURE IS MORE PLENTIFUL THAN CURRENTLY EXPECTED. COOLER WEATHER IS EXPECTED FOR WEDNESDAY NIGHT THROUGH FRIDAY AS CANADIAN HIGH SINKS SOUTH INTO THE GREAT LAKES. WILL LIKELY HAVE SOME SUB FREEZING NIGHTS...WHICH IS COMPLETELY NORMAL FOR THIS TIME OF THE YEAR...BUT MORE OF A CONCERN THIS YEAR DUE TO UNUSUAL WARMTH THAT HAS STARTED AN EARLY GROWING SEASON. BIG DIFFERENCES FOR NEXT SATURDAY AND SUNDAY WITH THE GFS AND ECMWF ALMOST 180 DEGREES OUT OF PHASE OVER OUR AREA. && .AVIATION...SKIES WERE GENERALLY CLEAR ACROSS THE FORECAST AREA LATE THIS AFTERNOON...BUT SOME STRATUS OVER THE UPPER PENINSULA AND NORTHERN LAKE MICHIGAN WAS EDGING SW TOWARD THE AREA...AND SOME MID/HIGH CLOUDS WERE APPROACHING CENTRAL WI. A COLD FRONT DROPPING SOUTH ACROSS THE REGION DURING THE EARLY TO MID EVENING WILL CAUSE A PRONOUNCED INCREASE IN NE WINDS IN THE FOX VALLEY AND LAKESHORE AREAS...WITH GUSTS TO 25 KTS POSSIBLE. THESE WINDS WILL LIKELY CAUSE THE MVFR STRATUS TO DROP INTO NORTHERN AND EASTERN WISCONSIN LATE THIS EVENING AND OVERNIGHT. HAVE ADDED A PERIOD OF MVFR CIGS TO THE RHI/GRB/ATW TAFS...BUT LEFT IT OUT OF AUW/CWA FOR NOW. UPSTREAM MID/HIGH CLOUDS SHOULD ALSO MOVE ACROSS C/EC WI TONIGHT. LINGERING MVFR CIGS SHOULD MIX OUT ON MONDAY MORNING... WITH MORE MID-LEVEL CLOUDS ARRIVING AHEAD OF THE NEXT SYSTEM LATE IN THE AFTERNOON. KIECKBUSCH && .MARINE... A WARM FRONT WILL PUSH NORTHWARD ACROSS THE AREA TUESDAY. GUSTS TO NEAR GALE FORCE FROM THE SOUTHEAST/SOUTH ARE POSSIBLE ON TUESDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM 2 AM TO 8 AM CDT MONDAY FOR WIZ005-010>013- 018-019-021. && $$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
253 PM CDT SAT MAR 24 2012 .SHORT TERM...TONIGHT AND SUNDAY. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A LARGE CUT-OFF LOW PRESSURE SYSTEM MOVING SE OVER KENTUCKY AND TENNESSEE EARLY THIS AFTERNOON...WHILE A SHORTWAVE OVER LAKE WINNIPEG IS DRIVING A COLD FRONT OVER THE NORTHERN MISSISSIPPI VALLEY. BETWEEN THESE FEATURES...CYCLONIC FLOW IS MAINTAINING A FAIRLY EXPANSIVE STRATO-CU DECK OVER THE WESTERN GREAT LAKES. SOME BREAKS IN THE STRATUS ARE GROWING LARGER OVER NW WISCONSIN WHERE A DRIER AIRMASS EXISTS ALOFT. AS THE COLD FRONT MOVES ACROSS THE REGION LATE TONIGHT INTO SUNDAY MORNING...CLOUDS AND FOG ARE THE MAIN FORECAST CONCERNS. TONIGHT...LOW CLOUDS SHOULD BE HANGING AROUND MUCH OF NORTHEAST AND INTO CENTRAL WISCONSIN FOR THE EARLY PART OF THE EVENING...WHERE MOISTURE IS DEEPER THROUGH THE COLUMN AND WEAK LOW LEVEL CONVERGENCE LINGERS. EVENTUALLY THOUGH...UPSTREAM DRIER AIR WILL MAKE INROADS OVER NORTH-CENTRAL WISCONSIN INTO NORTHEAST WISCONSIN THROUGH THE EVENING. HAVE LEFT SKY CONDITIONS SCATTERED-WEST TO BROKEN-EAST WITH THE UNCERTAINTY OF COVERAGE. COLD FRONT OVER THE NORTHERN MISSISSIPPI VALLEY WILL MOVE ACROSS THE AREA AFTER MIDNIGHT. FAIRLY WIDESPREAD STRATUS DECK BEHIND THE FRONT SO WILL SHOW SKIES RETURNING TO BROKEN AS THE BOUNDARY WORKS THROUGH. THE PRESSURE GRADIENT WILL TIGHTEN UP BEHIND THE FRONT AS WELL...WHICH WILL HELP DISSIPATE ANY FOG. LOWS RANGING FROM THE UPPER 30S NORTH TO THE UPPER 40S SOUTH. SUNDAY...THE COLD FRONT WILL MOVE SOUTHEAST ACROSS CENTRAL AND NORTHEAST WISCONSIN DURING THE MORNING...THEN CLEAR THE REGION FOR THE AFTERNOON. A VERY DRY AIRMASS WILL BE ARRIVING BEHIND THE COLD FRONT...SO WILL SEE AMPLE SUNSHINE MOVING IN BEHIND THE STRATUS ALONG THE FRONT. LOWERED DEWPOINTS OVER N-C WISCONSIN FOR THE AFTERNOON WHERE TEMPS WILL ONLY REACH INTO THE LOWER AND MIDDLE 50S. CENTRAL AND EAST-CENTRAL WISCONSIN SHOULD SEE HIGHS IN THE LOWER TO MIDDLE 60S. .LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. THE WARM PATTERN WILL CONTINUE NEXT WEEK...THOUGH NOT QUITE AS WARM AS THE LAST FEW WEEKS. LOWS AND HIGHS OF 5 TO 10 DEGREES ABOVE NORMAL ARE EXPECTED ON MOST DAYS BUT THAT WILL LIKELY FEEL CHILLY AFTER TEMPERATURES IN THE 70S AND 80S EARLIER THIS WEEK. NOT MUCH IN THE WAY OF PRECIPITATION IS EXPECTED AND ALL OR NEARLY ALL WILL BE RAIN. THE FIRST CHANCE OF PRECIPITATION IS MONDAY AS MID LEVEL WARM ADVECTION MOVES ACROSS THE AREA. WHATEVER FALLS SHOULD BE MOSTLY IN CENTRAL WISCONSIN AND BE MOSTLY SPRINKLES OR VERY LIGHT SHOWERS. BETTER CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY NIGHT AND TUESDAY AS DECENT UPPER LOW LIFTS NORTHEAST FROM THE PLAINS. THERE MAY BE ENOUGH COLD AIR NEAR THE GROUND FOR THE PRECIPITATION TO FALL AS SLEET IN NORTHCENTRAL WISCONSIN LATE MONDAY NIGHT AND EARLY TUESDAY. ANOTHER CHANCE OF SHOWERS THURSDAY NIGHT AND FRIDAY AS A WEAK SYSTEM PASSES BY TO THE NORTH. OTHERWISE GENERALLY MILD AND DRY WEATHER. A FROST OR FREEZE IS LIKELY SUNDAY NIGHT. WHILE THIS IS USUALLY NOT NOTEWORTHY AT THIS TIME OF THE YEAR...IT MAY BE A CONCERN FOR ORCHARD OWNERS AS SOEM TREES HAVE BEGUN FLOWERING DUE TO THE RECENT RECORD WARMTH. && .AVIATION...WIDESPREAD IFR AND SOME LIFR CIGS WILL GRADUALLY IMPROVE TO MVFR EARLY THIS AFTERNOON...AND POSSIBLY BECOME SCT BY LATE THIS AFTERNOON OR EARLY THIS EVENING. STILL PLENTY OF MOISTURE HANGING AROUND...SO IF SKIES CLEAR...POSSIBILITY OF FOG EXISTS...ESPECIALLY OVER NORTH-CENTRAL WISCONSIN. HOWEVER...UPSTREAM COLD FRONT WILL BE MOVING ACROSS THE AREA OVERNIGHT. BKN MVFR CIGS WILL LIKELY ARRIVE BEHIND THE COLD FRONT...AND WINDS WILL PICK UP FROM THE NW. THE COMBO OF THE TWO WILL LIKELY DISSIPATE ANY FOG FAIRLY QUICKLY. AMPLE DRY AIR BEHIND THE FRONT WILL ERODE BKN CIGS BY MID-MORNING...LEAVING VFR CONDITIONS THROUGH THE REMAINDER OF THE DAY. MPC && .MARINE... A COLD FRONT MOVING ACROSS THE AREA WILL BRING GUSTY NORTHEAST WINDS TO THE AREA SUNDAY NIGHT AND EARLY MONDAY. FUNNELING DOWN THE BAY COULD PRODUCE GUSTS TO 25 TO 30 KNOTS NEAR GREEN BAY. A WARM FRONT WILL PUSH NORTHWARD ACROSS THE AREA TUESDAY. GUSTS TO NEAR GALE FORCE FROM THE SOUTHEAST ARE POSSIBLE ON TUESDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MPC/RDM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
302 AM CDT SAT MAR 24 2012 .SHORT TERM...TODAY THROUGH MONDAY NIGHT 302 AM CDT SAT MAR 24 2012 THE MAIN FOCUS THROUGH EARLY NEXT WEEK IS WITH THE DWINDLING RAIN CHANCES THIS MORNING FOLLOWED BY THE RETURN OF PRECIPITATION SUNDAY NIGHT INTO MONDAY NIGHT. THE CUT OFF LOW TO THE SOUTH WILL CONTINUE TO MAKE SOME HEADWAY EAST TODAY AS IT TAKES AIM AT THE OHIO RIVER VALLEY. A FEW SHOWERS AND POCKETS OF DRIZZLE WILL REMAIN POSSIBLE THIS MORNING ACROSS SOUTHERN WISCONSIN AND NORTHEAST IOWA ALONG THE WEAKENING 850-925MB MOISTURE TRANSPORT THAT WILL ALSO BE PULLING EAST ALONG WITH THE LOW. WITH LIGHT WINDS...MOIST LOW LEVELS AND RECENT RAINFALL...SOME FOG HAS DEVELOPED ACROSS THE REGION. SOME LOCALLY DENSE FOG WILL BE POSSIBLE AT TIMES THIS MORNING...THOUGH NOT WIDESPREAD ENOUGH TO BE CONSIDERED FOR AN ADVISORY AT THIS POINT WITH VISIBILITY IN THE 1-3SM RANGE THROUGHOUT THE REGION WITH JUST A LOW LEVEL STRATUS DECK IN SOME LOCATIONS. AS THE LOW CONTINUES TO PROPAGATE EAST THIS MORNING AND RIDGING MOVES IN FROM THE WEST...DRIER AIR SHOULD SLOWLY MAKE ITS WAY INTO THE REGION. THE 24.00Z NAM/ECMWF DO PRODUCE SOME QPF THIS AFTERNOON ACROSS WESTERN WISCONSIN...LIKELY DUE TO THE FEW HUNDRED J/KG OF MUCAPE THEY DEVELOP. THERE DOES NOT APPEAR TO BE MUCH OF A TRIGGER IN THE WAY OF A FORCING MECHANISM...SO WILL CONTINUE THE DRY FORECAST AFTER 18Z TODAY. AFTER THE RIDGE MOVES THROUGH TONIGHT...A COLD FRONT WILL QUICKLY DROP DOWN INTO THE REGION AND BRING SOME COOLER AIR DOWN WITH IT. THE 24.00Z NAM DOES PRODUCE SOME PRECIPITATION ALONG THE FRONT SUNDAY AFTERNOON...WHILE THE REST OF THE GUIDANCE EITHER HAS THE FRONT SOUTH OF THE FORECAST AREA BY 18Z OR DO NOT PRODUCE ANY SHOWERS. THE 24.00Z NAM FORECAST SOUNDINGS SHOW AN UNCAPPED ATMOSPHERE WITH THE FRONT ACTING AS THE INITIATOR. AGAIN...HAVE OPTED TO KEEP SUNDAY DRY GIVEN THAT THE NAM APPEARS TO BE THE OUTLIER WITH OTHER GUIDANCE KEEPING THE INSTABILITY MUCH LOWER. COOLER 850MB AIR WILL MAKE IT DOWN ACROSS WISCONSIN TO THE MISSISSIPPI RIVER VALLEY SUNDAY NIGHT INTO MONDAY AND WILL LIMIT HOW MUCH TEMPERATURES ARE ABLE TO WARM. THIS FRONT WILL STALL OUT ACROSS THE PLAINS WITH A FAIRLY TIGHT TEMPERATURE GRADIENT IN PLACE TO THE NORTHEAST OF THE FRONT. THIS SETUP WILL PRODUCE A STRONG FRONTOGENESIS CIRCULATION THROUGH THE REGION STARTING SUNDAY NIGHT AND LASTING INTO MONDAY NIGHT. WHILE THE PRECIPITATION TYPE WILL LIKELY BE ALL RAIN THROUGHOUT...THERE ARE SOME INDICATIONS THAT THIS COLD...SHALLOW AIR MASS COULD COME CLOSE TO BEING COLD ENOUGH TO CAUSE THE LIQUID TO FREEZE INTO ICE/SLEET. SURFACE TEMPERATURES ARE FORECAST TO DROP INTO THE 30S MONDAY MORNING ALONG AND EAST OF THE MISSISSIPPI...BUT SHOULD STAY ABOVE FREEZING AS THE PRECIPITATION FALLS. TEMPERATURES IN THE SHALLOW COLD LAYER DROP TO AROUND -5C JUST BELOW 900MB OFF OF THE 24.00Z NAM IN WESTERN WISCONSIN. THAT SHOULD NOT BE COLD ENOUGH TO REFREEZE INTO ICE...BUT ITS CLOSE ENOUGH...ALONG WITH SURFACE TEMPERATURES...TO THE CRITICAL THRESHOLDS THAT IT MERITS WATCHING. AS THE NEXT UPPER LEVEL TROUGH EJECTS OUT OF THE ROCKIES MONDAY INTO MONDAY NIGHT...THE FRONTOGENETIC CIRCULATION WILL STRENGTHEN AND LIFT NORTH AND BRING SOME BETTER CHANCES FOR PRECIPITATION TO DEVELOP. .LONG TERM...TUESDAY THROUGH FRIDAY NIGHT 302 AM CDT SAT MAR 24 2012 THE BIG QUESTION TO START OFF THE EXTENDED PERIOD IS WITH THE SYSTEM THAT TRACKS THROUGH THE REGION ON TUESDAY AND WHETHER THE TIMING WILL WORK OUT FOR THE DEVELOPMENT OF ORGANIZED CONVECTION. THE 24.00Z GFS/ECMWF/GEM ALL FORM A BAND OF PRECIPITATION TUESDAY MORNING ALONG AND NORTHEAST OF THE WARM FRONT DUE TO ISENTROPIC LIFT/FRONTOGENESIS WITH THIS BAND LIFTING NORTH TOWARD LAKE SUPERIOR BY 18Z TUESDAY. GIVEN A BRIEF PERIOD OF WARMING BETWEEN THIS FRONT AND THE COLD FRONT...WHICH APPEARS TO COME THROUGH TUESDAY AFTERNOON...THERE SHOULD BE A SMALL WINDOW WHERE SOME WEAK INSTABILITY DEVELOPS AHEAD OF THE COLD FRONT. MID LEVEL LAPSE RATES ARE NOT VERY STEEP DUE TO THE CORE OF THE MID LEVEL LOW GOING THROUGH THE DAKOTAS...SO IT WILL BE TOUGH TO DEVELOP ANY STRONG INSTABILITY. GIVEN THE TIMING OF THE MID LEVEL TROUGH COMING THROUGH...IT APPEARS THAT THE FORCING FROM IT MAY GO MORE TO THE NORTH AND BE THROUGH BEFORE ANY INSTABILITY CAN FORM IN THE AFTERNOON. AFTER THE COLD FRONT COMES THROUGH...VERY DRY AIR GETS ADVECTED INTO THE REGION IN THE DRY SLOT OF THE SYSTEM. FORECAST SOUNDINGS FROM THE 24.00Z GFS SHOW MIXING UP TO 800MB WITH WIND GUSTS IN THE 30-40KT RANGE POSSIBLE BASED ON MOMENTUM TRANSFER. HIGH PRESSURE WILL THEN SETUP FROM SOUTHERN CANADA INTO THE UPPER MISSISSIPPI RIVER VALLEY WEDNESDAY INTO THURSDAY BEFORE LOW LEVEL MOISTURE RETURN BRINGS SHOWERS AND STORMS BACK INTO THE REGION THURSDAY NIGHT INTO NEXT WEEKEND. && .AVIATION...THROUGH 06Z SUNDAY 1135 PM CDT FRI MAR 23 2012 THE CLOUDS HAVE BEEN SLOWLY DISSIPATING ACROSS SOUTHEAST MINNESOTA THROUGH THE EVENING. BASED ON IR SATELLITE...KRST IS NOW VERY CLOSE TO THE EDGE OF THE CLOUDS WITH A VERY SLOW SOUTHWARD DRIFT OCCURRING. THIS SHOULD ALLOW THE CLOUDS TO BRIEFLY CLEAR LONG ENOUGH TO ALLOW DENSE FOG AND IFR CEILINGS TO QUICKLY FORM. THE 24.01Z HRRR SUGGESTS THAT DENSE FOG WILL FORM OVER SOUTH CENTRAL MINNESOTA AND NORTH CENTRAL IOWA JUST TO THE WEST OF KRST. PLENTY OF LOW LEVEL MOISTURE STILL RESIDES OVER THE AREA ALONG WITH LIGHT WINDS...SO IF THE CLOUDS CAN CLEAR OUT...WOULD EXPECT THE FOG TO FORM. KLSE IS DEEPER INTO THE CLOUDS...BUT WITH THE SOUTHWARD DRIFT...STILL HAS A CHANCE OF CLEARING OUT LATE ALLOWING THE FOG TO FORM. HAVE CONTINUED THE IFR CONDITIONS FOR BOTH SITES UNCHANGED FROM THE PREVIOUS FORECAST. EXPECTING THE FOG TO BEGIN LIFTING BY MID MORNING WITH MVFR CONDITIONS THEN PREVAILING INTO THE MID TO LATE AFTERNOON BEFORE THE CLOUDS SCATTER OUT. && .ARX WATCHES/WARNINGS/ADVISORIES... 302 AM CDT SAT MAR 24 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...HALBACH LONG TERM...HALBACH AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1135 PM CDT FRI MAR 23 2012 .SHORT TERM...TONIGHT THROUGH MONDAY 332 PM CDT FRI MAR 23 2012 MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES AND FOG TONIGHT THROUGH EARLY SATURDAY MORNING. FOCUS THEN TURNS TO TEMPERATURES AND PRECIPITATION CHANCES ON MONDAY. LATEST WATER VAPOR IMAGERY SHOWED A BROAD LOW PRESSURE SYSTEM CENTERED OVER SOUTHERN MISSOURI. GULF OF MEXICO MOISTURE CONTINUES TO STREAM NORTH AND WEST OF THE LOW INTO THE UPPER MISSISSIPPI RIVER VALLEY. THE LOW IS EXPECTED TO MOVE EAST INTO THE OHIO RIVER VALLEY TONIGHT. CLEARING NOTED ON VISIBLE SATELLITE THIS AFTERNOON ACROSS SOUTHWEST MINNESOTA INTO NORTHWEST IOWA...AS HIGH PRESSURE EDGED IN FROM THE DAKOTAS. WILL HAVE TO KEEP A CLOSE WATCH ON CLOUD TRENDS AND THE PRESSURE GRADIENT TONIGHT. IF THE WINDS GO CALM OR ANY CLEARING OCCURS...DENSE FOG WOULD QUICKLY DEVELOP GIVEN THE NEARLY SATURATED AIRMASS IN PLACE OVER THE FORECAST AREA. HAVE ADDED AREAS OF FOG TO THE FORECAST FOR PORTIONS OF SOUTHEAST MINNESOTA INTO NORTHEAST IOWA...AND PATCHY FOG ACROSS ALL OF THE WISCONSIN COUNTIES FROM MIDNIGHT INTO MID SATURDAY MORNING. SCATTERED RAIN SHOWERS WILL PERSIST THROUGH THIS EVENING AS THE MOISTURE CONTINUES TO STREAM INTO THE FORECAST AREA FROM THE SOUTHEAST. PLAN ON DECREASING SHOWER ACTIVITY EARLY SATURDAY MORNING AS THE LOW STARTS TO SHIFT EAST. LOOK FOR LOW TEMPERATURES TONIGHT TO FALL INTO THE LOWER 50S...POSSIBLY THE UPPER 40S IF ANY CLEARING OCCURS. HIGH PRESSURE WILL BUILD INTO THE AREA TOMORROW WITH SHOWER CHANCES ENDING ACROSS WISCONSIN BY SATURDAY AFTERNOON. PLAN ON DECREASING CLOUDS AS THE HIGH MOVES IN. HIGH TEMPERATURES WILL RANGE FROM THE MID TO LOWER 60S ACROSS NORTH CENTRAL WISCONSIN TO AROUND 70 ACROSS NORTHEAST IOWA. COOLER AIR WILL SETTLE INTO THE AREA SUNDAY THROUGH SUNDAY NIGHT AS CANADIAN HIGH PRESSURE BUILDS IN FROM THE NORTHEAST. 850 MB TEMPERATURES WILL RANGE FROM 6C ACROSS NORTHERN WISCONSIN TO AROUND 10 C ACROSS NORTHEAST IOWA EARLY IN THE DAY ON SUNDAY. THE COOLER AIR WILL THEN FILTER IN THROUGH THE DAY SUNDAY INTO SUNDAY NIGHT WITH 850 MB TEMPS FALLING INTO THE SINGLE DIGITS BELOW ZERO ACROSS NORTHERN WISCONSIN TO AROUND 6 C ACROSS NORTHEAST IOWA. PLAN ON HIGHS ON SUNDAY RANGING FROM AROUND 60 ACROSS NORTH CENTRAL WISCONSIN TO THE UPPER 60S ACROSS NORTHEAST IOWA. LOOK FOR LOWS TO FALL INTO THE LOWER 30S ACROSS NORTH CENTRAL WISCONSIN TO THE MIDDLE 40S ACROSS NORTHEAST IOWA...RATHER CHILLY COMPARED TO WHAT WE HAVE SEEN OVER THE PAST FEW WEEKS BUT STILL ABOVE NORMAL FOR THIS TIME OF YEAR. A BAROCLINIC ZONE IS EXPECTED TO STRETCH FROM NORTH CENTRAL NORTH DAKOTA SOUTHEAST THROUGH NORTHERN ILLINOIS...AND WILL BE THE FOCUS FOR SHOWER AND ISOLATED THUNDERSTORM DEVELOPMENT ON MONDAY ACROSS SOUTHEAST MINNESOTA...NORTHEAST IOWA AND PORTIONS OF SOUTHWEST WISCONSIN. HAVE LOWERED DEWPOINTS INTO THE LOWER TEENS ACROSS NORTH CENTRAL AND CENTRAL WISCONSIN MONDAY AFTERNOON...THIS PRODUCES RELATIVE HUMIDITY VALUES IN THE MID TO LOWER 20S. THE BAROCLINIC ZONE WILL LIFT NORTHEAST AS A WARM FRONT SETS UP ACROSS THE DAKOTAS AND LIFTS NORTHEAST. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT...SOME POSSIBLY SEVERE ACROSS FAR SOUTHWEST MINNESOTA THROUGH THE DAKOTAS...AS A STRONG LOW PRESSURE SYSTEM DEVELOPS. LOOK FOR MORE SEASONABLE HIGHS ACROSS THE AREA ON MONDAY WITH HIGHS RANGING FROM THE UPPER 40S ACROSS NORTH CENTRAL WISCONSIN TO THE LOWER 50S ACROSS NORTHEAST IOWA. EAST WINDS WILL INCREASE ACROSS THE FORECAST AREA ON MONDAY AS THE LOW DEEPENS ACROSS SOUTH DAKOTA. LOOK FOR WINDS TO INCREASE INTO THE 10 TO 20 MPH RANGE MONDAY AFTERNOON WITH GUSTS TO AROUND 25 MPH POSSIBLE. THE WARM FRONT IS EXPECTED TO LIFT INTO THE FORECAST AREA MONDAY NIGHT INTO TUESDAY MORNING BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE FORECAST AREA. PLAN ON LOWS FALLING INTO THE UPPER 30S TO LOWER 40S. .LONG TERM...TUESDAY THROUGH FRIDAY 332 PM CDT FRI MAR 23 2012 23.12 MEDIUM RANGE FORECAST MODELS CONTINUE TO INDICATE THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS TUESDAY AFTERNOON INTO TUESDAY EVENING AS A STRONG LOW PRESSURE SYSTEM MOVES EAST INTO THE REGION FROM THE DAKOTAS. THE MAJOR LIMITING FACTOR IS INSTABILITY. MODELS ARE STRUGGLING TO GENERATE HIGH CAPE VALUES...WITH CAPE RANGING FORM 200 TO 800 J/KG IN A VERY NARROW CORRIDOR RIGHT ALONG THE COLD FRONT. SHEAR IS RATHER STRONG WITH THIS SYSTEM WITH 0-6 KM BULK SHEAR OF 45 TO 55 KT. 0-1 KM BULK SHEAR VALUES ARE VERY STRONG...WITH VALUES OF 30 TO 50 KTS. GIVEN THE STRENGTH OF THE SOUTHERLY FLOW...HIGHER DEWPOINTS AND WARMER AIR SHOULDNT HAVE ANY PROBLEMS ADVECTING NORTHWARD INTO THE FORECAST AREA AHEAD OF THE LOW. IF ANY SUNSHINE IS SEEN TUESDAY AFTERNOON...INSTABILITY SHOULD INCREASE LEADING TO RAPID THUNDERSTORM DEVELOPMENT ALONG AND AHEAD OF THE COLD FRONT TUESDAY AFTERNOON ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA. THESE STORMS SHOULD THEN PUSH INTO WESTERN WISCONSIN LATE TUESDAY AFTERNOON INTO TUESDAY EVENING. WILL HAVE TO CONTINUE TO CLOSELY MONITOR SEVERE THUNDERSTORM POTENTIAL THE NEXT FEW MODEL RUNS. IF THE THUNDERSTORMS CAN DEVELOP...STRONG WINDS AND ISOLATED TORNADOES WOULD BE THE PRIMARY CONCERNS. HIGH PRESSURE WILL BUILD IN BEHIND THE LOW TUESDAY NIGHT INTO WEDNESDAY AND REMAIN OVER THE REGION THROUGH THURSDAY. PLAN ON QUIET WEATHER WITH HIGHS IN THE 50S TO LOWER 60S WITH LOWS IN THE MIDDLE 30S TO LOWER 40S. ANOTHER TROUGH LOOKS TO TAKE AIM ON THE REGION THURSDAY NIGHT INTO FRIDAY BRINGING CHANCES FOR SHOWERS AND THUNDERSTORM TO THE AREA. && .AVIATION...THROUGH 06Z SUNDAY 1135 PM CDT FRI MAR 23 2012 THE CLOUDS HAVE BEEN SLOWLY DISSIPATING ACROSS SOUTHEAST MINNESOTA THROUGH THE EVENING. BASED ON IR SATELLITE...KRST IS NOW VERY CLOSE TO THE EDGE OF THE CLOUDS WITH A VERY SLOW SOUTHWARD DRIFT OCCURRING. THIS SHOULD ALLOW THE CLOUDS TO BRIEFLY CLEAR LONG ENOUGH TO ALLOW DENSE FOG AND IFR CEILINGS TO QUICKLY FORM. THE 24.01Z HRRR SUGGESTS THAT DENSE FOG WILL FORM OVER SOUTH CENTRAL MINNESOTA AND NORTH CENTRAL IOWA JUST TO THE WEST OF KRST. PLENTY OF LOW LEVEL MOISTURE STILL RESIDES OVER THE AREA ALONG WITH LIGHT WINDS...SO IF THE CLOUDS CAN CLEAR OUT...WOULD EXPECT THE FOG TO FORM. KLSE IS DEEPER INTO THE CLOUDS...BUT WITH THE SOUTHWARD DRIFT...STILL HAS A CHANCE OF CLEARING OUT LATE ALLOWING THE FOG TO FORM. HAVE CONTINUED THE IFR CONDITIONS FOR BOTH SITES UNCHANGED FROM THE PREVIOUS FORECAST. EXPECTING THE FOG TO BEGIN LIFTING BY MID MORNING WITH MVFR CONDITIONS THEN PREVAILING INTO THE MID TO LATE AFTERNOON BEFORE THE CLOUDS SCATTER OUT. && .ARX WATCHES/WARNINGS/ADVISORIES... 332 PM CDT FRI MAR 23 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...WETENKAMP LONG TERM....WETENKAMP AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
611 PM MDT SUN MAR 25 2012 .UPDATE... DENSE CLOUDS HAVE KEPT TEMPERATURES AND GUSTY WINDS DOWN ACROSS AREAS WHERE FUELS ARE REPORTED CURED. COOLER TEMPERATURES AND LESS WINDS HAVE ALLEVIATED ANY FIRE DANGERS TODAY. THUS THE RED FLAG WARNINGS HAVE BEEN CANCELLED A LITTLE WHILE AGO. ATTENTION TURNS TO MONDAY WITH A WIDESPREAD STRONG WIND EVENT UNFOLDING. WENT AHEAD UPGRADED THE FIRE WEATHER WATCHES TO RED FLAG WARNINGS FOR AREAS EAST OF THE LARAMIE RANGE OUT INTO THE PANHANDLE. UPDATES HAVE BEEN SENT. CLAYCOMB && .AVIATION...00Z TAFS MAIN CONCERN FOR SOUTHEAST WYOMING AND NEBRASKA PANHANDLE AIRPORTS MONDAY LOOK TO BE WINDS. A POWERFAL...YET DRY PACIFIC LOW PRESSURE SYSTEM SET TO MOVE INTO WESTERN WYOMING TONIGHT...CREATING VERY STRONG WINDS ACROSS SOUTHEAST WYOMING BY MORNING. THESE WINDS WILL SPREAD OUT INTO THE PANHANDLE TOMORROW AFTERNOON. STARTUS LOOKS TO RETURN TO THE PANHANDLE OVERNIGHT WITH THE HRRR FORECASTING IFR CEILINGS AROUND 07Z OR SO. HAVE DELAYED ONSET SOME...BUT WILL GET A BETTER GRASP ON THE 06Z TAFS. CLAYCOMB && .PREV DISCUSSION... /ISSUED 301 PM MDT SUN MAR 25 2012/ SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT... TONIGHT...ANOTHER MILD NIGHT WITH WARM AIRMASS IN PLACE ALONG WITH DECENT MIXING AND LOW LEVEL MOISTURE HANGING IN...ESPECIALLY EAST OF INTERSTATE 25. LOW TEMPERATURES SOME 15 TO 20 DEGREES ABOVE NORMAL. BOUNDARY LAYER RELATIVE HUMIDITY AND LOW LEVEL WINDS BACKING TO SOUTHEAST WILL AID IN FOG AND LOW CLOUD FORMATION NORTH OF A LUSK TO ALLIANCE LINE AFTER MIDNIGHT. MONDAY...IMPRESSIVELY STRONG NEGATIVELY TILTED SHORTWAVE TROUGH MOVES TO EASTERN WYOMING IN THE AFTERNOON AS ITS ASSOCIATED POWERFUL PACIFIC ORIGIN COLD FRONT MOVES QUICKLY WEST TO EAST ACROSS OUR COUNTIES FROM LATE MORNING THROUGH LATE AFTERNOON. ALL FACTORS POINTING TO A WIDESPREAD HIGH WIND EVENT AFTER COLD FRONTAL PASSAGE...THUS WE HAVE UPGRADED THE HIGH WIND WATCH TO A HIGH WIND WARNING DUE TO HIGH CONFIDENCE AND ALSO TO GIVE OUR CUSTOMERS AN EARLY HEADS UP ON THE STRONG WINDS. COMBINATION OF STRONG DOWNWARD MOTION INDICATED ON THE 500-300 MB AND 700-500 MB QG PROGS...ALONG WITH PROGGED SURFACE THROUGH 700 MB GRADIENTS... STRONG COLD AIR ADVECTION AND PERFECT TIMING ON COLD FRONTAL PASSAGE SUGGEST A HIGH LIKELIHOOD OF A WIDESPREAD HIGH WIND EVENT IN THE AFTERNOON AND EARLY EVENING. EVEN 700 MB WINDS PROGGED FROM 50-65 KNOTS AFTER COLD FRONTAL PASSAGE AND THESE WINDS WILL BE TRANSPORTED TO THE SURFACE DUE TO DOWNWARD MOMENTUM TRANSFER FROM SUBSIDENCE AFTER THE SHORTWAVE TROUGH PASSAGE. ALTHOUGH LOW AND MID LEVEL MOISTURE WILL BE QUITE SCANT...THERE SHOULD BE ENOUGH FOR AT LEAST ISOLATED AFTERNOON THUNDERSTORMS NORTH OF A LARAMIE TO CHADRON LINE. QUITE A VARIANCE IN NAM AND GFS PROGGED HIGH TEMPERATURES AT SOME LOCATIONS...WILL BLEND IN THE MIDDLE AND BLEND WITH OUR NEIGHBORING OFFICES FOR THE MOST LIKELY FORECAST. MONDAY NIGHT...WITH THE PROGGED SURFACE THROUGH 700 MB GRADIENT AND STRONG COLD AIR ADVECTION CONTINUING INTO THE EVENING AS WELL AS DECENT DOWNWARD MOTION INDICATED ON THE 500-300 MB AND 700-500 MB QG PROGS...WILL EXTEND THE HIGH WIND WARNING UNTIL 9 PM...THEN WINDS SHOULD SUBSIDE UNDER HIGH WIND CRITERIA...THOUGH WOULD NOT BE SURPRISED TO SEE A FEW LOCATIONS CONTINUE HIGH WINDS BEYOND 9 PM. TUESDAY...ZONAL FLOW ALOFT...WEST TO EAST...AND WEAKER SURFACE THROUGH 700 MB GRADIENTS...ALONG WITH LIMITED LOW AND MID LEVEL MOISTURE WILL PRODUCE ANOTHER MILD AND DRY DAY. TUESDAY NIGHT...LOW AMPLITUDE SHORTWAVE RIDGING ALOFT WILL PROMOTE LIGHT SOUTH TO SOUTHWEST WINDS AND A MILD NIGHT WITH LOW TEMPERATURES ABOUT 10 DEGREES ABOVE NORMAL. LONG TERM...WEDNESDAY THROUGH SUNDAY...THERE ARE SOME DIFFERENCES BETWEEN THE 00Z AND 12Z MEDIUM RANGE MODEL GUIDANCE...BUT NOT SIGNIFICANT FOR MAJOR CHANGES TO THE GOING FORECAST. THE TREND OF UNSEASONABLY MILD TEMPERATURES AND DRY CONDITIONS WILL CONTINUE... WHICH WILL MAINTAIN THE WILDLAND FIRE DANGER. AN UPPER RIDGE WILL MOVE EAST ACROSS THE REGION WEDNESDAY...AND INTO THE PLAINS ON THURSDAY. ON WEDNESDAY...MINIMUM RELATIVE HUMIDITIES FALL TO CRITICAL LEVELS...HOWEVER WINDS EAST OF THE LARAMIE RANGE SHOULD NOT REACH CRITERIA. AREAS ALONG AND WEST OF THE RANGE WILL MEET WIND CRITERIA BUT FUELS ARE NOT READY FOR RAPID FIRE GROWTH. THIS COULD CHANGE DURING THE COURSE OF THE WEEK WITH THE LACK OF MOISTURE AND CONTINUED GUSTY WEST TO SOUTHWEST WINDS. LOW RELATIVE HUMIDITIES ARE EXPECTED THURSDAY AND FRIDAY AFTERNOON...WITH THE GUSTY WINDS AFFECTING THE REMAINDER OF THE EASTERN PLAINS AND ADJACENT WESTERN NEBRASKA PANHANDLE. FOR THE UPCOMING WEEKEND... THE FLOW ALOFT BACKS TO THE SOUTHWEST AND AMPLIFIES IN ADVANCE OF THE NEXT UPPER TROUGH MOVING INTO THE PACIFIC NORTHWEST. A PACIFIC LOW PRESSURE SYSTEM AND COLD FRONT APPROACHES THE REGION SUNDAY... WITH PRECIPITATION SPREADING EAST ACROSS THE CWA SUNDAY NIGHT. AVIATION...18Z TAF ISSUANCE...IFR CEILINGS SLOW TO SCATTER AT SIDNEY...BUT SHOULD DO SO BY MID AFTERNOON AS SOUTH TO SOUTHEAST BOUNDARY LAYER WINDS INCREASE. ELSEWHERE...EXPECT VFR CONDITIONS WITH SCATTERED TO BROKEN HIGH CLOUDS. SOUTHERLY SURFACE WINDS WILL BE BREEZY AT TIMES...ESPECIALLY FOR THE SOUTHEAST WYOMING AIRFIELDS AND SCOTTSBLUFF WHERE GUSTS OF 20 TO 25 KT WILL BE POSSIBLE. LOW LEVEL SOUTHEASTERLY FLOW WILL TRANSPORT SOME MOISTURE INTO THE WESTERN PANHANDLE LATER TONIGHT...WITH THE POSSIBILITY OF MVFR TO LOCAL IFR CEILINGS AND VISIBILITIES IN LOW STRATUS AND PATCHY FOG. BEST CHANCE FOR THESE CONDITIONS WILL BE FROM CHADRON THROUGH ALLIANCE AND SIDNEY. FIRE WEATHER...MINIMUM AFTERNOON HUMIDITIES TODAY WILL RANGE FROM 10 TO 20 PERCENT ACROSS SOUTHEAST WYOMING WITH GUSTY WINDS UP TO 30 MPH. CRITICAL FIRE WEATHER CONDITIONS WILL OCCUR ON MONDAY AS A STRONG PACIFIC ORIGIN COLD FRONT SWEEPS ACROSS THE DISTRICT FROM LATE MORNING THROUGH AFTERNOON...ALONG WITH STRONG WINDS AND LOW RELATIVE HUMIDITIES. WINDS WILL SUBSIDE MONDAY EVENING. MORE NEAR CRITICAL FIRE WEATHER CONDITIONS WILL OCCUR TUESDAY INTO THE WEEKEND WITH LOW RELATIVE HUMIDITIES AND GUSTY WINDS SOME OF THE AFTERNOONS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...RED FLAG WARNING FROM 10 AM MONDAY TO 7 PM MONDAY FOR WYZ101- WYZ102-WYZ106-WYZ107-WYZ108-WYZ116-WYZ117-WYZ118-WYZ119. HIGH WIND WARNING FROM 2 PM MONDAY TO 9 PM MONDAY FOR WYZ101- WYZ102-WYZ106-WYZ107-WYZ108-WYZ116-WYZ117-WYZ118-WYZ119. HIGH WIND WARNING FROM 11 AM MONDAY TO 9 PM MONDAY FOR WYZ104- WYZ105-WYZ109-WYZ110-WYZ111-WYZ113-WYZ115. NE...HIGH WIND WARNING FROM 2 PM MONDAY TO 9 PM MONDAY FOR NEZ002- NEZ003-NEZ019-NEZ020-NEZ021-NEZ054-NEZ055-NEZ095-NEZ096. RED FLAG WARNING FROM 10 AM MONDAY TO 7 PM MONDAY FOR NEZ002- NEZ003-NEZ019-NEZ020-NEZ021-NEZ054-NEZ055-NEZ095-NEZ096. && $$ SHORT TERM/FIRE WEATHER...RUBIN LONG TERM/AVIATION...JAMSKI
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
458 AM CDT MON MAR 26 2012 .DISCUSSION... 325 AM...WEAK UPPER WAVE SHIFTING SOUTHEAST ACROSS SOUTHERN MN AND SOUTHWEST WI EARLY THIS MORNING WITH AN AREA OF SHOWERS AND A FEW TS. MODELS SEEM CONSISTENT THAT THIS WILL PUSH INTO NORTHWEST IL LATER THIS MORNING. WHILE QPF AMOUNTS WILL BE LIGHT PERHAPS MANY AREAS ONLY SEEING A TRACE...HAVE INCLUDED A CHANCE OF SHOWERS WITH COVERAGE EXPECTED TO DECREASE INTO THE AFTERNOON HRS. DESPITE THE LOW PRECIP CHANCES...APPEARS MOSTLY CLOUDY SKIES WILL PREVAIL THROUGH MUCH OF THE DAY WHICH WILL LIMIT HEATING AS TEMPS ARE NOW FALLING THROUGH THE 40S WITH MANY LOCATIONS ALREADY INTO THE UPPER 30S. STILL EXPECT SOME SUN ACROSS THE SOUTHERN CWA BUT TEMPS ACROSS THE NORTH A BIT TRICKY. OVERALL ONLY TWEAKED THEM LOWER A DEGREE OR TWO BUT THERE IS THE POTENTIAL FOR TEMPS TO BE COOLER THAN CURRENTLY ADVERTISED. FLOW TURNS BACK SOUTHERLY TONIGHT AND COULD BE SOME WARM AIR ADVECTION PRECIP OVERNIGHT INTO EARLY TUESDAY MORNING BUT APPEARS THE BULK OF THIS ACTIVITY WOULD REMAIN NORTH OF THE CWA. BUT SIMILAR TO TODAY/S WAVE...LOOKS LIKE THERE WILL BE PLENTY OF CLOUD COVER AT LEAST ACROSS NORTHERN IL. COULD SEE A QUICK DROP IN TEMPS THIS EVENING AND DEPENDING ON HOW EXTENSIVE CLOUD COVER BECOMES... COULD BE SOME FROST ACROSS THE EASTERN CWA/NORTHWEST INDIANA WHERE LOWS COULD BE IN THE MID 30S. TOO MUCH UNCERTAINTY FOR ANY HEADLINES THIS MORNING AND WILL LET THE DAY SHIFT TAKE A LOOK AT THIS POTENTIAL MORE CLOSELY. LOW PRESSURE WILL LIFT ACROSS THE NORTHERN PLAINS TUESDAY AND ACROSS THE UPPER LAKES TUESDAY NIGHT WITH A TRAILING COLD FRONT SWEEPING ACROSS THE AREA LATE TUESDAY AFTERNOON INTO EARLY WEDNESDAY MORNING. MODELS ARE IN FAIRLY GOOD AGREEMENT WITH MOISTURE POOLING JUST AHEAD OF THIS FRONT WITH A TONGUE OF DEWPOINTS IN THE THE MID/UPPER 50S. POTENTIAL FOR SEVERE STORMS WILL BE PARTIALLY LIMITED BY STRONG FORCING FROM THIS AREA NORTH AND BEST INSTABILITY FROM THIS AREA SOUTH...WE/LL BE SOMEWHERE IN THE MIDDLE. BEST TIMING APPEARS TO BE FROM MID AFTERNOON INTO EARLY EVENING WITH PEAK HEATING. THE GRADIENT TIGHTENS AHEAD OF THE COLD FRONT ON TUESDAY AND EXPECT SOUTHERLY WINDS IN THE 20 TO 30 MPH RANGE WITH HIGHER GUSTS PERHAPS AS HIGH AS 35 MPH AT TIMES...WHICH WILL BE DEPENDENT ON THE DEPTH OF THE MIXING. WINDS RELAX TUESDAY NIGHT THEN INCREASE AGAIN ON WEDNESDAY FROM THE WEST AS DRIER AIR AND EVENTUALLY COOLER AIR SPREADS ACROSS THE REGION. WITH MOSTLY SUNNY SKIES... TEMPS SHOULD EASILY REBOUND INTO THE 60S WITH 70S POSSIBLE ACROSS THE SOUTHERN CWA BEFORE COLDER AIR ARRIVES. NORTHEAST/EASTERLY FLOW WILL KEEP THE LAKESHORE AREAS COOLER THURSDAY AND FRIDAY WITH ANOTHER STORM SYSTEM TO AFFECT THE AREA FRIDAY INTO SATURDAY. GFS ENDS PRECIP A LITTLE FASTER THAN THE ECMWF SATURDAY BUT OVERALL BOTH ARE IN FAIR AGREEMENT WITH THIS NEXT SYSTEM. CMS && .FIRE WEATHER... 255 PM CDT WILL NEED TO MONITOR WEDNESDAY FOR A POTENTIAL HEIGHTENED FIRE DANGER. STRONG WEST WINDS AND DEEP MIXING WILL TAKE PLACE BEHIND A COLD FRONT THAT MOVES THROUGH TUESDAY NIGHT. STILL A LOT OF UNCERTAINTY REGARDING HOW QUICKLY THE COOLER AIR ARRIVES...BUT DOES APPEAR AS THOUGH DEWPOINTS WILL FALL OFF QUICKLY. WILL CONTINUE TO MONITOR TRENDS THE NEXT FEW DAYS. IZZI && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 10Z... * CIG TRENDS OVERNIGHT * NE WINDS AND GUSTS THROUGH THE MORNING * PRECIP POTENTIAL IN THE MORNING SHEA //DISCUSSION...10Z... THE MAIN LOW END MVFR CLOUDS CONTINUE TO MOVE AWAY FROM ALL OF THE TERMINALS...BUT SOME STRATOCU HAS MOVED IN FROM THE NORTHWEST WHERE SHOWER ACTIVITY IS WORKING SOUTHEAST. GUIDANCE SEEMS TO HAVE A GOOD HANDLE ON THE EXTENT OF THE PRECIP...AND WHILE IT WILL LIKELY BE A NARROW CORRIDOR THAT IS IMPACTED...IT SHOULD REMAIN WEST OF ORD. OBSERVATIONS ARE ALSO SHOWING THAT CIGS WILL REMAIN VFR IF/WHEN PRECIP OCCURS. RADAR/TIME EXTRAPOLATION BRINGS THE SHOWERS INTO RFD BY 10Z AND ACROSS ORD/MDW BY 12-13Z. THE ONE BIG POSITIVE FOR THE EASTERN TERMINALS WILL BE THE AMOUNT OF DRY AIR THAT IS INTRUDING. WHILE RADAR RETURNS WILL LOOK IMPRESSIVE...MUCH WILL FALL AS VIRGA TO START AND EVENTUALLY REACH THE GROUND FROM VFR BASES. DRY AIR WILL CONTINUE TO BLEED IN FROM THE NORTHWEST AND SHOULD SHUT OFF CHANCES FOR ORD/MDW/DPA/GYY EARLY...BUT RFD MAY LINGER A BIT LONGER. SHEA //PREVIOUS 06Z DISCUSSION... EARLY EVENING STRATUS HAS SHIFTED TO THE SOUTH AND AND WEST OF THE EASTERN TERMINALS AS OF 06Z...AND THE TREND OF CIGS RAISING AND OVERALL COVERAGE DECREASING...WILL CONTINUE. 11-3.9UM SATELLITE IMAGERY NOT SHOWING MUCH WITH REGARDS TO LOW CLOUDS ACROSS THE LAKE...WITH THE BULK OF THE LAKE STRATUS STAYING GENERALLY IN THE MKE TO RAC CORRIDOR. THERE ARE SOME HINTS THAT SOME OF THE LOWER CLOUDS MAY LINGER AROUND THE UGN/PWK AND MAYBE ORD TERMINALS THROUGH ABOUT 10Z...AND WITH THE UNCERTAINTY...WILL MAINTAIN THE TEMPO...BUT RAISE HEIGHTS. THROUGH THE REST OF THE NIGHT AND INTO THE DAY TOMORROW...WINDS WILL GRADUALLY WORK THEIR WAY AROUND THE COMPASS...GOING FROM NE TO E AND EVENTUALLY SE-SSE LATE TOMORROW NIGHT. GUSTS WILL ALSO BE ON THE DOWN TREND INTO THE MORNING HOURS...AND WILL HOLD OUT ON THE LOW 20S TO UPPER TEENS GUSTS THROUGH THE 18Z HOUR. PRECIP CHANCES WILL BE TRICKIEST FOR RFD THIS MORNING. GUIDANCE IS BRINGING SHOWERS THAT ARE CURRENTLY WEST OF LSE...SOUTHEAST AND ACROSS RFD INTO THE 12Z HOUR. RAW EXTRAPOLATION FROM RADAR IS A LITTLE CLOSER TO 11Z...BUT ONE THING THE MODELS MAY BE STRUGGLING WITH IS HOW DRY THE AIRMASS MOVING IN FROM THE NORTH ACTUALLY IS. NOT FULLY CONFIDENT THAT THE SHOWERS WILL LAST BEFORE FALLING APART...AND WILL ADD A PERIOD OF VCSH FROM 11 TO 15Z DUE TO THE UNCERTAINTY AT THIS POINT. CONFIDENCE IS FALLING WITH RESPECT TO ORD AND MDW...IF THEY WILL REMAIN DRY...THOUGH THE 03Z HRRR IS REALLY INCREASING THE SHOWERS. WILL NEED TO MONITOR AND ADJUST AS NECESSARY. SHEA //ORD AND MDW CONFIDENCE...UPDATED 10Z... * MODERATE CONFIDENCE ON CIG TRENDS * HIGH CONFIDENCE WITH WIND FORECAST * MODERATE TO LOW WITH ORD/MDW STAYING DRY THIS MORNING SHEA //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 06Z... * TUESDAY...GUSTY SOUTHERLY WINDS. A SLIGHT CHC OF TSRA FROM MID AFTN INTO THE EVE. LLWS POTENTIAL IN THE EVENING AND EARLY OVERNIGHT. * WEDNESDAY...MVFR POSSIBLE DURING THE NIGHT. * THURSDAY...VFR. * FRIDAY...CHC OF TSRA. * SATURDAY...CHC OF TSRA. SHEA && .MARINE... 255 AM CDT HIGH PRESSURE ACROSS ONTARIO WILL CONTINUE TO SLIDE EAST...ALLOWING COLD AIR TO COME RACING DOWN THE LAKE THIS MORNING. WITH THE STRONG COLD AIR ADVECTION...WINDS HAVE PICKED UP CONSIDERABLY...ALLOWING SOME COASTAL LOCATIONS TO SEE GALE FORCE GUSTS. THOSE HIGHER GUSTS SHOULD BE TEMPORARY...AND WINDS WILL GRADUALLY DIMINISH TO 15 TO 25 KT THROUGHOUT THE DAY. FLOW WILL THEN ORIENT ITSELF TO MORE EASTERLY OVERNIGHT..AND GRADUALLY BECOME SOUTHEAST TOWARDS DAWN. THE GRADIENT WILL TIGHTEN CONSIDERABLY AS LOW PRESSURE LIFTS ACROSS THE PLAINS THIS AFTERNOON...ALLOWING GALE FORCE WINDS ACROSS MUCH OF THE OPEN WATERS...AS WELL AS THE ILLINOIS NEARSHORE WATERS LATE TONIGHT. SURFACE FLOW LOOKS TO BE IN THE LOW 30 KT RANGE FOR MUCH OF THE LAKE...WITH GOOD MIXING OF HIGHER MOMENTUM AIR FROM ALOFT THROUGH AT LEAST THE AFTERNOON ON TUESDAY...WITH GUSTS POTENTIALLY PEAKING BETWEEN 35 AND 40 KT. IT IS INTO THE AFTERNOON AND EVENING HOURS THAT TEMPERATURES ALOFT BEGIN TO WARM...AND WIND GUST POTENTIAL WILL DIMINISH...BUT STILL REMAIN IN THE 25 TO 30 KT RANGE THROUGH DAWN ON WEDNESDAY. ALSO EXTENDED THE SMALL CRAFT ADVISORY FOR THE INDIANA SHORE THROUGH WEDNESDAY. CONFIDENCE IS NOT AS HIGH THAT THEY WILL REACH FULL GALE CRITERIA AS OPPOSED TO THE ILLINOIS SHORES. THE AFOREMENTIONED LOW WILL THEN CROSS NORTHERN LAKE SUPERIOR TUESDAY NIGHT...BRINGING WINDS AROUND TO THE WEST...THEN NORTHWEST AND NORTH AS ANOTHER AREA OF HIGH PRESSURE APPROACHES FROM THE WEST. WINDS WILL THEN TURN SOUTHEASTERLY INTO FRIDAY AS THE HIGH SHIFTS TO THE EAST. SHEA && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM TUESDAY. GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742- LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...4 AM TUESDAY TO 4 PM TUESDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 9 PM TUESDAY. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
410 AM CDT MON MAR 26 2012 .DISCUSSION... 325 AM...WEAK UPPER WAVE SHIFTING SOUTHEAST ACROSS SOUTHERN MN AND SOUTHWEST WI EARLY THIS MORNING WITH AN AREA OF SHOWERS AND A FEW TS. MODELS SEEM CONSISTENT THAT THIS WILL PUSH INTO NORTHWEST IL LATER THIS MORNING. WHILE QPF AMOUNTS WILL BE LIGHT PERHAPS MANY AREAS ONLY SEEING A TRACE...HAVE INCLUDED A CHANCE OF SHOWERS WITH COVERAGE EXPECTED TO DECREASE INTO THE AFTERNOON HRS. DESPITE THE LOW PRECIP CHANCES...APPEARS MOSTLY CLOUDY SKIES WILL PREVAIL THROUGH MUCH OF THE DAY WHICH WILL LIMIT HEATING AS TEMPS ARE NOW FALLING THROUGH THE 40S WITH MANY LOCATIONS ALREADY INTO THE UPPER 30S. STILL EXPECT SOME SUN ACROSS THE SOUTHERN CWA BUT TEMPS ACROSS THE NORTH A BIT TRICKY. OVERALL ONLY TWEAKED THEM LOWER A DEGREE OR TWO BUT THERE IS THE POTENTIAL FOR TEMPS TO BE COOLER THAN CURRENTLY ADVERTISED. FLOW TURNS BACK SOUTHERLY TONIGHT AND COULD BE SOME WARM AIR ADVECTION PRECIP OVERNIGHT INTO EARLY TUESDAY MORNING BUT APPEARS THE BULK OF THIS ACTIVITY WOULD REMAIN NORTH OF THE CWA. BUT SIMILAR TO TODAY/S WAVE...LOOKS LIKE THERE WILL BE PLENTY OF CLOUD COVER AT LEAST ACROSS NORTHERN IL. COULD SEE A QUICK DROP IN TEMPS THIS EVENING AND DEPENDING ON HOW EXTENSIVE CLOUD COVER BECOMES... COULD BE SOME FROST ACROSS THE EASTERN CWA/NORTHWEST INDIANA WHERE LOWS COULD BE IN THE MID 30S. TOO MUCH UNCERTAINTY FOR ANY HEADLINES THIS MORNING AND WILL LET THE DAY SHIFT TAKE A LOOK AT THIS POTENTIAL MORE CLOSELY. LOW PRESSURE WILL LIFT ACROSS THE NORTHERN PLAINS TUESDAY AND ACROSS THE UPPER LAKES TUESDAY NIGHT WITH A TRAILING COLD FRONT SWEEPING ACROSS THE AREA LATE TUESDAY AFTERNOON INTO EARLY WEDNESDAY MORNING. MODELS ARE IN FAIRLY GOOD AGREEMENT WITH MOISTURE POOLING JUST AHEAD OF THIS FRONT WITH A TONGUE OF DEWPOINTS IN THE THE MID/UPPER 50S. POTENTIAL FOR SEVERE STORMS WILL BE PARTIALLY LIMITED BY STRONG FORCING FROM THIS AREA NORTH AND BEST INSTABILITY FROM THIS AREA SOUTH...WE/LL BE SOMEWHERE IN THE MIDDLE. BEST TIMING APPEARS TO BE FROM MID AFTERNOON INTO EARLY EVENING WITH PEAK HEATING. THE GRADIENT TIGHTENS AHEAD OF THE COLD FRONT ON TUESDAY AND EXPECT SOUTHERLY WINDS IN THE 20 TO 30 MPH RANGE WITH HIGHER GUSTS PERHAPS AS HIGH AS 35 MPH AT TIMES...WHICH WILL BE DEPENDENT ON THE DEPTH OF THE MIXING. WINDS RELAX TUESDAY NIGHT THEN INCREASE AGAIN ON WEDNESDAY FROM THE WEST AS DRIER AIR AND EVENTUALLY COOLER AIR SPREADS ACROSS THE REGION. WITH MOSTLY SUNNY SKIES... TEMPS SHOULD EASILY REBOUND INTO THE 60S WITH 70S POSSIBLE ACROSS THE SOUTHERN CWA BEFORE COLDER AIR ARRIVES. NORTHEAST/EASTERLY FLOW WILL KEEP THE LAKESHORE AREAS COOLER THURSDAY AND FRIDAY WITH ANOTHER STORM SYSTEM TO AFFECT THE AREA FRIDAY INTO SATURDAY. GFS ENDS PRECIP A LITTLE FASTER THAN THE ECMWF SATURDAY BUT OVERALL BOTH ARE IN FAIR AGREEMENT WITH THIS NEXT SYSTEM. CMS && .FIRE WEATHER... 255 PM CDT WILL NEED TO MONITOR WEDNESDAY FOR A POTENTIAL HEIGHTENED FIRE DANGER. STRONG WEST WINDS AND DEEP MIXING WILL TAKE PLACE BEHIND A COLD FRONT THAT MOVES THROUGH TUESDAY NIGHT. STILL A LOT OF UNCERTAINTY REGARDING HOW QUICKLY THE COOLER AIR ARRIVES...BUT DOES APPEAR AS THOUGH DEWPOINTS WILL FALL OFF QUICKLY. WILL CONTINUE TO MONITOR TRENDS THE NEXT FEW DAYS. IZZI && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 09Z... * CIG TRENDS OVERNIGHT * NE WINDS AND GUSTS THROUGH THE MORNING * PRECIP POTENTIAL IN THE MORNING OUT WEST SHEA //DISCUSSION...09Z... THE MAIN LOW END MVFR CLOUDS CONTINUE TO MOVE AWAY FROM ALL OF THE TERMINALS...BUT SOME STRATOCU HAS MOVED IN FROM THE NORTHWEST WHERE SHOWER ACTIVITY IS WORKING SOUTHEAST. GUIDANCE SEEMS TO HAVE A GOOD HANDLE ON THE EXTENT OF THE PRECIP...AND WHILE IT WILL LIKELY BE A NARROW CORRIDOR THAT IS IMPACTED...IT SHOULD REMAIN WEST OF ORD. OBSERVATIONS ARE ALSO SHOWING THAT CIGS WILL REMAIN VFR IF/WHEN PRECIP OCCURS. SHEA //PREVIOUS 06Z DISCUSSION... EARLY EVENING STRATUS HAS SHIFTED TO THE SOUTH AND AND WEST OF THE EASTERN TERMINALS AS OF 06Z...AND THE TREND OF CIGS RAISING AND OVERALL COVERAGE DECREASING...WILL CONTINUE. 11-3.9UM SATELLITE IMAGERY NOT SHOWING MUCH WITH REGARDS TO LOW CLOUDS ACROSS THE LAKE...WITH THE BULK OF THE LAKE STRATUS STAYING GENERALLY IN THE MKE TO RAC CORRIDOR. THERE ARE SOME HINTS THAT SOME OF THE LOWER CLOUDS MAY LINGER AROUND THE UGN/PWK AND MAYBE ORD TERMINALS THROUGH ABOUT 10Z...AND WITH THE UNCERTAINTY...WILL MAINTAIN THE TEMPO...BUT RAISE HEIGHTS. THROUGH THE REST OF THE NIGHT AND INTO THE DAY TOMORROW...WINDS WILL GRADUALLY WORK THEIR WAY AROUND THE COMPASS...GOING FROM NE TO E AND EVENTUALLY SE-SSE LATE TOMORROW NIGHT. GUSTS WILL ALSO BE ON THE DOWN TREND INTO THE MORNING HOURS...AND WILL HOLD OUT ON THE LOW 20S TO UPPER TEENS GUSTS THROUGH THE 18Z HOUR. PRECIP CHANCES WILL BE TRICKIEST FOR RFD THIS MORNING. GUIDANCE IS BRINGING SHOWERS THAT ARE CURRENTLY WEST OF LSE...SOUTHEAST AND ACROSS RFD INTO THE 12Z HOUR. RAW EXTRAPOLATION FROM RADAR IS A LITTLE CLOSER TO 11Z...BUT ONE THING THE MODELS MAY BE STRUGGLING WITH IS HOW DRY THE AIRMASS MOVING IN FROM THE NORTH ACTUALLY IS. NOT FULLY CONFIDENT THAT THE SHOWERS WILL LAST BEFORE FALLING APART...AND WILL ADD A PERIOD OF VCSH FROM 11 TO 15Z DUE TO THE UNCERTAINTY AT THIS POINT. CONFIDENCE IS MUCH HIGHER THAT ORD/MDW WILL REMAIN DRY...THOUGH THE 03Z HRRR IS REALLY INCREASING THE SHOWERS. WILL NEED TO MONITOR AND ADJUST AS NECESSARY. SHEA //ORD AND MDW CONFIDENCE...UPDATED 09Z... * MODERATE CONFIDENCE ON CIG TRENDS * LOW CONFIDENCE ON BASES FALLING BELOW 015 OVER THE NEXT FEW HOURS * HIGH CONFIDENCE WITH WIND FORECAST * MODERATE TO HIGH CONFIDENCE WITH ORD/MDW STAYING DRY THIS MORNING SHEA //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 06Z... * TUESDAY...GUSTY SOUTHERLY WINDS. A SLIGHT CHC OF TSRA FROM MID AFTN INTO THE EVE. LLWS POTENTIAL IN THE EVENING AND EARLY OVERNIGHT. * WEDNESDAY...MVFR POSSIBLE DURING THE NIGHT. * THURSDAY...VFR. * FRIDAY...CHC OF TSRA. * SATURDAY...CHC OF TSRA. SHEA && .MARINE... 255 AM CDT HIGH PRESSURE ACROSS ONTARIO WILL CONTINUE TO SLIDE EAST...ALLOWING COLD AIR TO COME RACING DOWN THE LAKE THIS MORNING. WITH THE STRONG COLD AIR ADVECTION...WINDS HAVE PICKED UP CONSIDERABLY...ALLOWING SOME COASTAL LOCATIONS TO SEE GALE FORCE GUSTS. THOSE HIGHER GUSTS SHOULD BE TEMPORARY...AND WINDS WILL GRADUALLY DIMINISH TO 15 TO 25 KT THROUGHOUT THE DAY. FLOW WILL THEN ORIENT ITSELF TO MORE EASTERLY OVERNIGHT..AND GRADUALLY BECOME SOUTHEAST TOWARDS DAWN. THE GRADIENT WILL TIGHTEN CONSIDERABLY AS LOW PRESSURE LIFTS ACROSS THE PLAINS THIS AFTERNOON...ALLOWING GALE FORCE WINDS ACROSS MUCH OF THE OPEN WATERS...AS WELL AS THE ILLINOIS NEARSHORE WATERS LATE TONIGHT. SURFACE FLOW LOOKS TO BE IN THE LOW 30 KT RANGE FOR MUCH OF THE LAKE...WITH GOOD MIXING OF HIGHER MOMENTUM AIR FROM ALOFT THROUGH AT LEAST THE AFTERNOON ON TUESDAY...WITH GUSTS POTENTIALLY PEAKING BETWEEN 35 AND 40 KT. IT IS INTO THE AFTERNOON AND EVENING HOURS THAT TEMPERATURES ALOFT BEGIN TO WARM...AND WIND GUST POTENTIAL WILL DIMINISH...BUT STILL REMAIN IN THE 25 TO 30 KT RANGE THROUGH DAWN ON WEDNESDAY. ALSO EXTENDED THE SMALL CRAFT ADVISORY FOR THE INDIANA SHORE THROUGH WEDNESDAY. CONFIDENCE IS NOT AS HIGH THAT THEY WILL REACH FULL GALE CRITERIA AS OPPOSED TO THE ILLINOIS SHORES. THE AFOREMENTIONED LOW WILL THEN CROSS NORTHERN LAKE SUPERIOR TUESDAY NIGHT...BRINGING WINDS AROUND TO THE WEST...THEN NORTHWEST AND NORTH AS ANOTHER AREA OF HIGH PRESSURE APPROACHES FROM THE WEST. WINDS WILL THEN TURN SOUTHEASTERLY INTO FRIDAY AS THE HIGH SHIFTS TO THE EAST. SHEA && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM TUESDAY. GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742- LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...4 AM TUESDAY TO 4 PM TUESDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 9 PM TUESDAY. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
325 AM CDT MON MAR 26 2012 .DISCUSSION... 325 AM...WEAK UPPER WAVE SHIFTING SOUTHEAST ACROSS SOUTHERN MN AND SOUTHWEST WI EARLY THIS MORNING WITH AN AREA OF SHOWERS AND A FEW TS. MODELS SEEM CONSISTENT THAT THIS WILL PUSH INTO NORTHWEST IL LATER THIS MORNING. WHILE QPF AMOUNTS WILL BE LIGHT PERHAPS MANY AREAS ONLY SEEING A TRACE...HAVE INCLUDED A CHANCE OF SHOWERS WITH COVERAGE EXPECTED TO DECREASE INTO THE AFTERNOON HRS. DESPITE THE LOW PRECIP CHANCES...APPEARS MOSTLY CLOUDY SKIES WILL PREVAIL THROUGH MUCH OF THE DAY WHICH WILL LIMIT HEATING AS TEMPS ARE NOW FALLING THROUGH THE 40S WITH MANY LOCATIONS ALREADY INTO THE UPPER 30S. STILL EXPECT SOME SUN ACROSS THE SOUTHERN CWA BUT TEMPS ACROSS THE NORTH A BIT TRICKY. OVERALL ONLY TWEAKED THEM LOWER A DEGREE OR TWO BUT THERE IS THE POTENTIAL FOR TEMPS TO BE COOLER THAN CURRENTLY ADVERTISED. FLOW TURNS BACK SOUTHERLY TONIGHT AND COULD BE SOME WARM AIR ADVECTION PRECIP OVERNIGHT INTO EARLY TUESDAY MORNING BUT APPEARS THE BULK OF THIS ACTIVITY WOULD REMAIN NORTH OF THE CWA. BUT SIMILAR TO TODAY/S WAVE...LOOKS LIKE THERE WILL BE PLENTY OF CLOUD COVER AT LEAST ACROSS NORTHERN IL. COULD SEE A QUICK DROP IN TEMPS THIS EVENING AND DEPENDING ON HOW EXTENSIVE CLOUD COVER BECOMES... COULD BE SOME FROST ACROSS THE EASTERN CWA/NORTHWEST INDIANA WHERE LOWS COULD BE IN THE MID 30S. TOO MUCH UNCERTAINTY FOR ANY HEADLINES THIS MORNING AND WILL LET THE DAY SHIFT TAKE A LOOK AT THIS POTENTIAL MORE CLOSELY. LOW PRESSURE WILL LIFT ACROSS THE NORTHERN PLAINS TUESDAY AND ACROSS THE UPPER LAKES TUESDAY NIGHT WITH A TRAILING COLD FRONT SWEEPING ACROSS THE AREA LATE TUESDAY AFTERNOON INTO EARLY WEDNESDAY MORNING. MODELS ARE IN FAIRLY GOOD AGREEMENT WITH MOISTURE POOLING JUST AHEAD OF THIS FRONT WITH A TONGUE OF DEWPOINTS IN THE THE MID/UPPER 50S. POTENTIAL FOR SEVERE STORMS WILL BE PARTIALLY LIMITED BY STRONG FORCING FROM THIS AREA NORTH AND BEST INSTABILITY FROM THIS AREA SOUTH...WE/LL BE SOMEWHERE IN THE MIDDLE. BEST TIMING APPEARS TO BE FROM MID AFTERNOON INTO EARLY EVENING WITH PEAK HEATING. THE GRADIENT TIGHTENS AHEAD OF THE COLD FRONT ON TUESDAY AND EXPECT SOUTHERLY WINDS IN THE 20 TO 30 MPH RANGE WITH HIGHER GUSTS PERHAPS AS HIGH AS 35 MPH AT TIMES...WHICH WILL BE DEPENDENT ON THE DEPTH OF THE MIXING. WINDS RELAX TUESDAY NIGHT THEN INCREASE AGAIN ON WEDNESDAY FROM THE WEST AS DRIER AIR AND EVENTUALLY COOLER AIR SPREADS ACROSS THE REGION. WITH MOSTLY SUNNY SKIES... TEMPS SHOULD EASILY REBOUND INTO THE 60S WITH 70S POSSIBLE ACROSS THE SOUTHERN CWA BEFORE COLDER AIR ARRIVES. NORTHEAST/EASTERLY FLOW WILL KEEP THE LAKESHORE AREAS COOLER THURSDAY AND FRIDAY WITH ANOTHER STORM SYSTEM TO AFFECT THE AREA FRIDAY INTO SATURDAY. GFS ENDS PRECIP A LITTLE FASTER THAN THE ECMWF SATURDAY BUT OVERALL BOTH ARE IN FAIR AGREEMENT WITH THIS NEXT SYSTEM. CMS && .FIRE WEATHER... 255 PM CDT WILL NEED TO MONITOR WEDNESDAY FOR A POTENTIAL HEIGHTENED FIRE DANGER. STRONG WEST WINDS AND DEEP MIXING WILL TAKE PLACE BEHIND A COLD FRONT THAT MOVES THROUGH TUESDAY NIGHT. STILL A LOT OF UNCERTAINTY REGARDING HOW QUICKLY THE COOLER AIR ARRIVES...BUT DOES APPEAR AS THOUGH DEWPOINTS WILL FALL OFF QUICKLY. WILL CONTINUE TO MONITOR TRENDS THE NEXT FEW DAYS. IZZI && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * CIG TRENDS OVERNIGHT * NE WINDS AND GUSTS THROUGH THE MORNING * PRECIP POTENTIAL IN THE MORNING SHEA //DISCUSSION...UPDATED 06Z... EARLY EVENING STRATUS HAS SHIFTED TO THE SOUTH AND AND WEST OF THE EASTERN TERMINALS AS OF 06Z...AND THE TREND OF CIGS RAISING AND OVERALL COVERAGE DECREASING...WILL CONTINUE. 11-3.9UM SATELLITE IMAGERY NOT SHOWING MUCH WITH REGARDS TO LOW CLOUDS ACROSS THE LAKE...WITH THE BULK OF THE LAKE STRATUS STAYING GENERALLY IN THE MKE TO RAC CORRIDOR. THERE ARE SOME HINTS THAT SOME OF THE LOWER CLOUDS MAY LINGER AROUND THE UGN/PWK AND MAYBE ORD TERMINALS THROUGH ABOUT 10Z...AND WITH THE UNCERTAINTY...WILL MAINTAIN THE TEMPO...BUT RAISE HEIGHTS. THROUGH THE REST OF THE NIGHT AND INTO THE DAY TOMORROW...WINDS WILL GRADUALLY WORK THEIR WAY AROUND THE COMPASS...GOING FROM NE TO E AND EVENTUALLY SE-SSE LATE TOMORROW NIGHT. GUSTS WILL ALSO BE ON THE DOWN TREND INTO THE MORNING HOURS...AND WILL HOLD OUT ON THE LOW 20S TO UPPER TEENS GUSTS THROUGH THE 18Z HOUR. PRECIP CHANCES WILL BE TRICKIEST FOR RFD THIS MORNING. GUIDANCE IS BRINGING SHOWERS THAT ARE CURRENTLY WEST OF LSE...SOUTHEAST AND ACROSS RFD INTO THE 12Z HOUR. RAW EXTRAPOLATION FROM RADAR IS A LITTLE CLOSER TO 11Z...BUT ONE THING THE MODELS MAY BE STRUGGLING WITH IS HOW DRY THE AIRMASS MOVING IN FROM THE NORTH ACTUALLY IS. NOT FULLY CONFIDENT THAT THE SHOWERS WILL LAST BEFORE FALLING APART...AND WILL ADD A PERIOD OF VCSH FROM 11 TO 15Z DUE TO THE UNCERTAINTY AT THIS POINT. CONFIDENCE IS MUCH HIGHER THAT ORD/MDW WILL REMAIN DRY...THOUGH THE 03Z HRRR IS REALLY INCREASING THE SHOWERS. WILL NEED TO MONITOR AND ADJUST AS NECESSARY. SHEA //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MODERATE TO HIGH CONFIDENCE ON CIG TRENDS * LOW CONFIDENCE ON BASES FALLING BELOW 015 OVER THE NEXT FEW HOURS * HIGH CONFIDENCE WITH WIND FORECAST * HIGH CONFIDENCE WITH ORD/MDW STAYING DRY THIS MORNING SHEA //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 06Z... * TUESDAY...GUSTY SOUTHERLY WINDS. A SLIGHT CHC OF TSRA FROM MID AFTN INTO THE EVE. LLWS POTENTIAL IN THE EVENING AND EARLY OVERNIGHT. * WEDNESDAY...MVFR POSSIBLE DURING THE NIGHT. * THURSDAY...VFR. * FRIDAY...CHC OF TSRA. * SATURDAY...CHC OF TSRA. SHEA && .MARINE... 255 AM CDT HIGH PRESSURE ACROSS ONTARIO WILL CONTINUE TO SLIDE EAST...ALLOWING COLD AIR TO COME RACING DOWN THE LAKE THIS MORNING. WITH THE STRONG COLD AIR ADVECTION...WINDS HAVE PICKED UP CONSIDERABLY...ALLOWING SOME COASTAL LOCATIONS TO SEE GALE FORCE GUSTS. THOSE HIGHER GUSTS SHOULD BE TEMPORARY...AND WINDS WILL GRADUALLY DIMINISH TO 15 TO 25 KT THROUGHOUT THE DAY. FLOW WILL THEN ORIENT ITSELF TO MORE EASTERLY OVERNIGHT..AND GRADUALLY BECOME SOUTHEAST TOWARDS DAWN. THE GRADIENT WILL TIGHTEN CONSIDERABLY AS LOW PRESSURE LIFTS ACROSS THE PLAINS THIS AFTERNOON...ALLOWING GALE FORCE WINDS ACROSS MUCH OF THE OPEN WATERS...AS WELL AS THE ILLINOIS NEARSHORE WATERS LATE TONIGHT. SURFACE FLOW LOOKS TO BE IN THE LOW 30 KT RANGE FOR MUCH OF THE LAKE...WITH GOOD MIXING OF HIGHER MOMENTUM AIR FROM ALOFT THROUGH AT LEAST THE AFTERNOON ON TUESDAY...WITH GUSTS POTENTIALLY PEAKING BETWEEN 35 AND 40 KT. IT IS INTO THE AFTERNOON AND EVENING HOURS THAT TEMPERATURES ALOFT BEGIN TO WARM...AND WIND GUST POTENTIAL WILL DIMINISH...BUT STILL REMAIN IN THE 25 TO 30 KT RANGE THROUGH DAWN ON WEDNESDAY. ALSO EXTENDED THE SMALL CRAFT ADVISORY FOR THE INDIANA SHORE THROUGH WEDNESDAY. CONFIDENCE IS NOT AS HIGH THAT THEY WILL REACH FULL GALE CRITERIA AS OPPOSED TO THE ILLINOIS SHORES. THE AFOREMENTIONED LOW WILL THEN CROSS NORTHERN LAKE SUPERIOR TUESDAY NIGHT...BRINGING WINDS AROUND TO THE WEST...THEN NORTHWEST AND NORTH AS ANOTHER AREA OF HIGH PRESSURE APPROACHES FROM THE WEST. WINDS WILL THEN TURN SOUTHEASTERLY INTO FRIDAY AS THE HIGH SHIFTS TO THE EAST. SHEA && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM TUESDAY. GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742- LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...4 AM TUESDAY TO 4 PM TUESDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 9 PM TUESDAY. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
300 AM CDT MON MAR 26 2012 .DISCUSSION... 255 PM CDT PRIMARY FORECAST CHALLENGES TODAY INCLUDE TEMPS THE NEXT COUPLE DAYS FOLLOWED BY PRECIP CHANCES WITH COLD FRONT APPROACHING TUESDAY NIGHT. ANOTHER REMARKABLY MILD DAY ON TAP ACROSS THE REGION WITH THE ONLY EXCEPTION BEING NEAR THE LAKE WHERE MORE ESTABLISHED LAKE BREEZE HAS KNOCKED TEMPS BACK DOWN INTO THE 50S...WITH EVEN SOME VERY LOW STRATUS/DENSE FOG RIGHT ALONG THE IMMEDIATE SHORE. FAIRLY STRONG HIGH PRESSURE OVER MANITOBA WILL MOVE SOUTHEAST TOWARD QUEBEC TONIGHT WITH STRENGTHENING NORTHERLY FLOW USHERING IN A COLDER AND DRIER AIR MASS INTO THE AREA TONIGHT. SKY COVER WILL BE TRICKY THE NEXT 24-48 HOURS...PARTICULARLY NEAR THE LAKE. SHORTWAVE IS PROGGED TO CREST THE RIDGE AND APPROACH FROM THE NORTHWEST TONIGHT AND RESULT IN INCREASING CLOUDINESS ON THE SYNOPTIC SCALE. IN FACT...NOT OUT OF THE QUESTION THAT THERE COULD EVEN BE A FEW SPRINKLES OR LIGHT SHOWERS OVER WESTERN PORTIONS OF THE CWA LATE TONIGHT/EARLY MONDAY. LAKE EFFECT STRATUS SHOULD GENERALLY BE ON THE DECREASE THIS EVENING WITH COLDER AIR FILTERING IN ALOFT WILL LIKELY SEE AN EVENTUAL TRANSITION TO LAKE EFFECT INSTABILITY STRATOCUMULUS LATE TONIGHT AND ESPECIALLY INTO MONDAY. HEIGHTS ALOFT BEGIN TO RISE MONDAY BUT SURFACE HIGH ISN`T QUITE AS PROGRESSIVE RESULTING IN A CHILLY NORTHEAST WIND OFF THE LAKE. IN FACT...WITH THE WINDS OFF THE LAKE AND THE CLOUD COVER TEMPS MAY BE HARD PRESSED TO CLIMB ABOVE AVERAGE FOR THE FIRST TIME IN WEEKS. ONE POSSIBLE SAVING GRACE KEEPING IT FROM BEING EVEN COLDER TOMORROW IS THE FACT LAKE TEMPS ARE APPROACHING 50F NOW...SO EVEN WITH A LONG FETCH NORTHEAST WIND TEMPS WILL PROBABLY ONLY BE HELD IN THE 40S. WINDS SHOULD VEER TO SOUTHEASTERLY MONDAY NIGHT AND EVENTUALLY SOUTH BY TUESDAY WITH WARMER AIR EVENTUALLY SPREADING NORTH INTO THE AREA. DOES APPEAR AS THOUGH THERE COULD BE A FAIR AMOUNT OF CLOUD COVER PLUS THE COOL START TO THE DAY SHOULD RESULT IN HIGHS PROBABLY HOLDING IN THE 60S...WHICH IS STILL WELL ABOVE AVERAGE. STRONG UPPER LOW AND ASSOCIATED SURFACE LOWS TRACK EAST ALONG THE CANADIAN BORDER TO OUR NORTH TUESDAY NIGHT WITH TRAILING COLD FRONT LIKELY TO MOVE ACROSS THE REGION TUESDAY NIGHT. MOISTURE RETURN DOES NT LOOK ALL THAT IMPRESSIVE AND SOMEWHAT DISJOINTED FROM THE STRONGER/DEEPER ASCENT THAT OCCURS FARTHER NORTH CLOSER TO THE UPPER LOW TRACK. BASED ON THE 12Z MODEL RUNS...NOT OVERLY IMPRESSED WITH OUR CONVECTIVE CHANCES AS FRONTAL TIMING IS LESS THAN IDEAL AND MOISTURE AND FORCING ARE BOTH MARGINAL TO DECENT AT BEST. HAVE MAINTAINED JUST CHANCE POPS FOR NOW WHICH ARE IN LINE WITH THE OBJECTIVE GUIDANCE NUMBERS. WINDS SHIFT TO THE WEST BEHIND THE COLD FRONT...BUT WITH STRONG MIXING AND OFFSHORE FLOW PLUS COLDER AIR LAGGING WELL BEHIND THE FRONT...WEDNESDAY LOOKS TO BE AS WARM IF NOT A BIT A WARMER OF A DAY THAN TUESDAY OUT AHEAD OF THE COLD FRONT. HAVE BUMPED TEMPS UP CLOSER TO IN LINE WITH WRF-NAM 2M TEMPS...BUT EVEN GOING FORECAST COULD BE A BIT CONSERVATIVE STILL GIVEN DEEP MIXING AND FULL SUNSHINE. ANOTHER SHOT OF COOLER MORE SEASONABLE TEMPS ARRIVE LATE IN THE WEEK WITH ANOTHER PERIOD OF NORTHEAST TO EAST WINDS OFF THE LAKE. DIFFERENCES APPEAR IN THE MEDIUM RANGE MODELS HEADING INTO NEXT WEEKEND WITH VARYING IDEAS ON THE PLACEMENT OF THE UPPER RIDGE AS WELL AS TIMING/INTENSITY OF VARIOUS WAVES RIPPLING THROUGH THE FLOW. GENERALLY DOES APPEAR THERE COULD BE ONE OR TWO BOUTS OF PRECIPITATION BUT WITH TIMING NEXT TO IMPOSSIBLE AT THIS POINT HAVE JUST BLANKETED SEVERAL PERIODS WITH SOME LOW ENDS POPS HEADING INTO NEXT WEEKEND...THOUGH AT THIS DISTANCE IT CERTAINLY IS NOT LOOKING LIKE A WASH OUT. IZZI && .FIRE WEATHER... 255 PM CDT WILL NEED TO MONITOR WEDNESDAY FOR A POTENTIAL HEIGHTENED FIRE DANGER. STRONG WEST WINDS AND DEEP MIXING WILL TAKE PLACE BEHIND A COLD FRONT THAT MOVES THROUGH TUESDAY NIGHT. STILL A LOT OF UNCERTAINTY REGARDING HOW QUICKLY THE COOLER AIR ARRIVES...BUT DOES APPEAR AS THOUGH DEWPOINTS WILL FALL OFF QUICKLY. WILL CONTINUE TO MONITOR TRENDS THE NEXT FEW DAYS. IZZI && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * CIG TRENDS OVERNIGHT * NE WINDS AND GUSTS THROUGH THE MORNING * PRECIP POTENTIAL IN THE MORNING SHEA //DISCUSSION...UPDATED 06Z... EARLY EVENING STRATUS HAS SHIFTED TO THE SOUTH AND AND WEST OF THE EASTERN TERMINALS AS OF 06Z...AND THE TREND OF CIGS RAISING AND OVERALL COVERAGE DECREASING...WILL CONTINUE. 11-3.9UM SATELLITE IMAGERY NOT SHOWING MUCH WITH REGARDS TO LOW CLOUDS ACROSS THE LAKE...WITH THE BULK OF THE LAKE STRATUS STAYING GENERALLY IN THE MKE TO RAC CORRIDOR. THERE ARE SOME HINTS THAT SOME OF THE LOWER CLOUDS MAY LINGER AROUND THE UGN/PWK AND MAYBE ORD TERMINALS THROUGH ABOUT 10Z...AND WITH THE UNCERTAINTY...WILL MAINTAIN THE TEMPO...BUT RAISE HEIGHTS. THROUGH THE REST OF THE NIGHT AND INTO THE DAY TOMORROW...WINDS WILL GRADUALLY WORK THEIR WAY AROUND THE COMPASS...GOING FROM NE TO E AND EVENTUALLY SE-SSE LATE TOMORROW NIGHT. GUSTS WILL ALSO BE ON THE DOWN TREND INTO THE MORNING HOURS...AND WILL HOLD OUT ON THE LOW 20S TO UPPER TEENS GUSTS THROUGH THE 18Z HOUR. PRECIP CHANCES WILL BE TRICKIEST FOR RFD THIS MORNING. GUIDANCE IS BRINGING SHOWERS THAT ARE CURRENTLY WEST OF LSE...SOUTHEAST AND ACROSS RFD INTO THE 12Z HOUR. RAW EXTRAPOLATION FROM RADAR IS A LITTLE CLOSER TO 11Z...BUT ONE THING THE MODELS MAY BE STRUGGLING WITH IS HOW DRY THE AIRMASS MOVING IN FROM THE NORTH ACTUALLY IS. NOT FULLY CONFIDENT THAT THE SHOWERS WILL LAST BEFORE FALLING APART...AND WILL ADD A PERIOD OF VCSH FROM 11 TO 15Z DUE TO THE UNCERTAINTY AT THIS POINT. CONFIDENCE IS MUCH HIGHER THAT ORD/MDW WILL REMAIN DRY...THOUGH THE 03Z HRRR IS REALLY INCREASING THE SHOWERS. WILL NEED TO MONITOR AND ADJUST AS NECESSARY. SHEA //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MODERATE TO HIGH CONFIDENCE ON CIG TRENDS * LOW CONFIDENCE ON BASES FALLING BELOW 015 OVER THE NEXT FEW HOURS * HIGH CONFIDENCE WITH WIND FORECAST * HIGH CONFIDENCE WITH ORD/MDW STAYING DRY THIS MORNING SHEA //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 06Z... * TUESDAY...GUSTY SOUTHERLY WINDS. A SLIGHT CHC OF TSRA FROM MID AFTN INTO THE EVE. LLWS POTENTIAL IN THE EVENING AND EARLY OVERNIGHT. * WEDNESDAY...MVFR POSSIBLE DURING THE NIGHT. * THURSDAY...VFR. * FRIDAY...CHC OF TSRA. * SATURDAY...CHC OF TSRA. SHEA && .MARINE... 255 AM CDT HIGH PRESSURE ACROSS ONTARIO WILL CONTINUE TO SLIDE EAST...ALLOWING COLD AIR TO COME RACING DOWN THE LAKE THIS MORNING. WITH THE STRONG COLD AIR ADVECTION...WINDS HAVE PICKED UP CONSIDERABLY...ALLOWING SOME COASTAL LOCATIONS TO SEE GALE FORCE GUSTS. THOSE HIGHER GUSTS SHOULD BE TEMPORARY...AND WINDS WILL GRADUALLY DIMINISH TO 15 TO 25 KT THROUGHOUT THE DAY. FLOW WILL THEN ORIENT ITSELF TO MORE EASTERLY OVERNIGHT..AND GRADUALLY BECOME SOUTHEAST TOWARDS DAWN. THE GRADIENT WILL TIGHTEN CONSIDERABLY AS LOW PRESSURE LIFTS ACROSS THE PLAINS THIS AFTERNOON...ALLOWING GALE FORCE WINDS ACROSS MUCH OF THE OPEN WATERS...AS WELL AS THE ILLINOIS NEARSHORE WATERS LATE TONIGHT. SURFACE FLOW LOOKS TO BE IN THE LOW 30 KT RANGE FOR MUCH OF THE LAKE...WITH GOOD MIXING OF HIGHER MOMENTUM AIR FROM ALOFT THROUGH AT LEAST THE AFTERNOON ON TUESDAY...WITH GUSTS POTENTIALLY PEAKING BETWEEN 35 AND 40 KT. IT IS INTO THE AFTERNOON AND EVENING HOURS THAT TEMPERATURES ALOFT BEGIN TO WARM...AND WIND GUST POTENTIAL WILL DIMINISH...BUT STILL REMAIN IN THE 25 TO 30 KT RANGE THROUGH DAWN ON WEDNESDAY. ALSO EXTENDED THE SMALL CRAFT ADVISORY FOR THE INDIANA SHORE THROUGH WEDNESDAY. CONFIDENCE IS NOT AS HIGH THAT THEY WILL REACH FULL GALE CRITERIA AS OPPOSED TO THE ILLINOIS SHORES. THE AFOREMENTIONED LOW WILL THEN CROSS NORTHERN LAKE SUPERIOR TUESDAY NIGHT...BRINGING WINDS AROUND TO THE WEST...THEN NORTHWEST AND NORTH AS ANOTHER AREA OF HIGH PRESSURE APPROACHES FROM THE WEST. WINDS WILL THEN TURN SOUTHEASTERLY INTO FRIDAY AS THE HIGH SHIFTS TO THE EAST. SHEA && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM TUESDAY. GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742- LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...4 AM TUESDAY TO 4 PM TUESDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 9 PM TUESDAY. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
254 AM CDT MON MAR 26 2012 .DISCUSSION... ISSUED 254 AM CDT MON MAR 26 2012 SHORT TERM...TODAY THROUGH WEDNESDAY BACKDOOR COLD FRONT WILL SINK THROUGH CENTRAL ILLINOIS THIS MORNING...ALLOWING A MUCH COOLER AIRMASS TO FILTER IN FROM THE NORTHEAST. THANKS TO CLOUD COVER AND AN E/NE FETCH OVER THE COLD WATERS OF LAKE MICHIGAN...AREAS ALONG AND NORTH OF I-74 WILL REMAIN IN THE 50S. FURTHER SOUTH...HIGH TEMPS WILL REACH THE LOWER TO MIDDLE 60S. AN AREA OF LIGHT SHOWERS ASSOCIATED WITH ISENTROPIC LIFT BEHIND THE BOUNDARY WILL TRACK SOUTHEASTWARD OUT OF MINNESOTA...BUT SHOULD STAY NORTH OF THE I-80 CORRIDOR THIS MORNING. AS UPPER RIDGE OVER THE PLAINS BUILDS EASTWARD...FRONT WILL GET PUSHED BACK NORTHWARD TONIGHT. THIS WILL RESULT IN A RETURN TO MUCH WARMER CONDITIONS FOR TUESDAY...WITH HIGH TEMPS ONCE AGAIN SOARING WELL INTO THE 70S. MEANWHILE...REMNANTS OF UPPER LOW CURRENTLY OVER SOUTHERN CALIFORNIA WILL LIFT NORTHEASTWARD INTO THE UPPER MIDWEST...FLATTENING THE PREVAILING RIDGE AND PUSHING A COLD FRONT TOWARD CENTRAL ILLINOIS. MODELS CONTINUE TO BE IN EXCELLENT AGREEMENT REGARDING TIMING OF FROPA TUESDAY NIGHT. AIRMASS AHEAD OF THE APPROACHING BOUNDARY WILL BECOME MODERATELY UNSTABLE TUESDAY AFTERNOON...WITH LIFTED INDEX VALUES REACHING THE -4 TO -6C RANGE. DESPITE GOOD INSTABILITY...CONVERGENCE ALONG FRONT WILL BE MINIMAL AND BEST UPPER DYNAMICS WILL REMAIN WELL TO THE N/NW. AS A RESULT...AM ONLY EXPECTING SCATTERED CONVECTION WITH THE FRONT. WILL MAINTAIN CHANCE POPS WEST OF I-55 TUESDAY AFTERNOON...THEN ACROSS THE BOARD TUESDAY NIGHT. FRONT WILL SETTLE SOUTHWARD INTO THE OHIO RIVER VALLEY ON WEDNESDAY...WITH PERHAPS A FEW LINGERING SHOWERS ACROSS THE FAR SE KILX CWA DURING THE MORNING. DESPITE FRONTAL PASSAGE...PACIFIC ORIGIN AIRMASS AND AMPLE SUNSHINE WILL ALLOW HIGH TEMPS TO ONCE AGAIN CLIMB INTO THE 70S. LONG TERM...THURSDAY THROUGH SUNDAY AFTER A WARM/DRY DAY ON THURSDAY...A PERIOD OF UNSETTLED WEATHER IS SETTING UP FOR THE END OF THE WEEK. BOTH THE GFS AND ECMWF CONTINUE TO ADVERTISE A ZONAL UPPER FLOW PATTERN DEVELOPING ACROSS THE CONUS BY THE WEEKEND INTO NEXT WEEK...WITH A SERIES OF DISTURBANCES EXPECTED TO TRACK FROM WEST TO EAST ACROSS THE COUNTRY. THE FIRST WAVE WILL APPROACH LATE THURSDAY NIGHT INTO FRIDAY...CAUSING THE OHIO RIVER VALLEY FRONT TO LIFT BACK NORTHWARD INTO THE AREA. WITH A BOUNDARY IN PLACE...PLENTY OF MOISTURE FLOWING NORTHWARD FROM THE GULF...AND A SHORT-WAVE TO PROVIDE LIFT...SHOWERS AND THUNDERSTORMS WILL BE A GOOD BET FOR BOTH FRIDAY AND SATURDAY. AFTER THAT...WAVE WILL PASS TO THE EAST AND DRY WEATHER WILL RETURN BY SUNDAY. BARNES && .AVIATION... ISSUED 1145 PM CDT SUN MAR 25 2012 COLD FRONT/LAKE BREEZE COMPOSITE BOUNDARY MAKING ITS WAY SOUTHWESTWARD THROUGH NORTHERN IL AND IS NEARING PIA/BMI. MAIN FORECAST CHALLENGE WILL BE IF ANY MVFR CLOUDS DEVELOP AFTER FRONTAL PASSAGE THROUGH SUNRISE. FORECAST SOUNDINGS FROM THE LATEST RUC DO SUPPORT CLOUD STRATOCU DEVELOPMENT AT ABOUT 5K FT FOR ALL TAF SITES...WITH A PERIOD OF 1K-2K FT CLOUDS IN THE 08Z-12Z TIME FRAME FOR ONLY PIA/BMI. ALTHOUGH THE SOUNDINGS DO NOT SHOW MVFR CLOUDS IN THE SPI-DEC-CMI CORRIDOR... WILL GIVE THEM A SCT LAYER AT 2K FT. BROKEN VFR STRATOCU WILL THEN DOMINATE ALL SITES THROUGH AT LEAST 00Z...THEN SOME BREAKUP MAY OCCUR SPI-DEC-CMI. WINDS BEHIND THE FRONT WILL INCREASE FROM THE EAST 14-18 KT AND HOLD UP THROUGH THE PERIOD...WITH GUSTS 25-30 KT DURING THE DAY MONDAY. 04 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
108 AM CDT MON MAR 26 2012 .DISCUSSION... 255 PM CDT PRIMARY FORECAST CHALLENGES TODAY INCLUDE TEMPS THE NEXT COUPLE DAYS FOLLOWED BY PRECIP CHANCES WITH COLD FRONT APPROACHING TUESDAY NIGHT. ANOTHER REMARKABLY MILD DAY ON TAP ACROSS THE REGION WITH THE ONLY EXCEPTION BEING NEAR THE LAKE WHERE MORE ESTABLISHED LAKE BREEZE HAS KNOCKED TEMPS BACK DOWN INTO THE 50S...WITH EVEN SOME VERY LOW STRATUS/DENSE FOG RIGHT ALONG THE IMMEDIATE SHORE. FAIRLY STRONG HIGH PRESSURE OVER MANITOBA WILL MOVE SOUTHEAST TOWARD QUEBEC TONIGHT WITH STRENGTHENING NORTHERLY FLOW USHERING IN A COLDER AND DRIER AIR MASS INTO THE AREA TONIGHT. SKY COVER WILL BE TRICKY THE NEXT 24-48 HOURS...PARTICULARLY NEAR THE LAKE. SHORTWAVE IS PROGGED TO CREST THE RIDGE AND APPROACH FROM THE NORTHWEST TONIGHT AND RESULT IN INCREASING CLOUDINESS ON THE SYNOPTIC SCALE. IN FACT...NOT OUT OF THE QUESTION THAT THERE COULD EVEN BE A FEW SPRINKLES OR LIGHT SHOWERS OVER WESTERN PORTIONS OF THE CWA LATE TONIGHT/EARLY MONDAY. LAKE EFFECT STRATUS SHOULD GENERALLY BE ON THE DECREASE THIS EVENING WITH COLDER AIR FILTERING IN ALOFT WILL LIKELY SEE AN EVENTUAL TRANSITION TO LAKE EFFECT INSTABILITY STRATOCUMULUS LATE TONIGHT AND ESPECIALLY INTO MONDAY. HEIGHTS ALOFT BEGIN TO RISE MONDAY BUT SURFACE HIGH ISN`T QUITE AS PROGRESSIVE RESULTING IN A CHILLY NORTHEAST WIND OFF THE LAKE. IN FACT...WITH THE WINDS OFF THE LAKE AND THE CLOUD COVER TEMPS MAY BE HARD PRESSED TO CLIMB ABOVE AVERAGE FOR THE FIRST TIME IN WEEKS. ONE POSSIBLE SAVING GRACE KEEPING IT FROM BEING EVEN COLDER TOMORROW IS THE FACT LAKE TEMPS ARE APPROACHING 50F NOW...SO EVEN WITH A LONG FETCH NORTHEAST WIND TEMPS WILL PROBABLY ONLY BE HELD IN THE 40S. WINDS SHOULD VEER TO SOUTHEASTERLY MONDAY NIGHT AND EVENTUALLY SOUTH BY TUESDAY WITH WARMER AIR EVENTUALLY SPREADING NORTH INTO THE AREA. DOES APPEAR AS THOUGH THERE COULD BE A FAIR AMOUNT OF CLOUD COVER PLUS THE COOL START TO THE DAY SHOULD RESULT IN HIGHS PROBABLY HOLDING IN THE 60S...WHICH IS STILL WELL ABOVE AVERAGE. STRONG UPPER LOW AND ASSOCIATED SURFACE LOWS TRACK EAST ALONG THE CANADIAN BORDER TO OUR NORTH TUESDAY NIGHT WITH TRAILING COLD FRONT LIKELY TO MOVE ACROSS THE REGION TUESDAY NIGHT. MOISTURE RETURN DOESNT LOOK ALL THAT IMPRESSIVE AND SOMEWHAT DISJOINTED FROM THE STRONGER/DEEPER ASCENT THAT OCCURS FARTHER NORTH CLOSER TO THE UPPER LOW TRACK. BASED ON THE 12Z MODEL RUNS...NOT OVERLY IMPRESSED WITH OUR CONVECTIVE CHANCES AS FRONTAL TIMING IS LESS THAN IDEAL AND MOISTURE AND FORCING ARE BOTH MARGINAL TO DECENT AT BEST. HAVE MAINTAINED JUST CHANCE POPS FOR NOW WHICH ARE IN LINE WITH THE OBJECTIVE GUIDANCE NUMBERS. WINDS SHIFT TO THE WEST BEHIND THE COLD FRONT...BUT WITH STRONG MIXING AND OFFSHORE FLOW PLUS COLDER AIR LAGGING WELL BEHIND THE FRONT...WEDNESDAY LOOKS TO BE AS WARM IF NOT A BIT A WARMER OF A DAY THAN TUESDAY OUT AHEAD OF THE COLD FRONT. HAVE BUMPED TEMPS UP CLOSER TO IN LINE WITH WRF-NAM 2M TEMPS...BUT EVEN GOING FORECAST COULD BE A BIT CONSERVATIVE STILL GIVEN DEEP MIXING AND FULL SUNSHINE. ANOTHER SHOT OF COOLER MORE SEASONABLE TEMPS ARRIVE LATE IN THE WEEK WITH ANOTHER PERIOD OF NORTHEAST TO EAST WINDS OFF THE LAKE. DIFFERENCES APPEAR IN THE MEDIUM RANGE MODELS HEADING INTO NEXT WEEKEND WITH VARYING IDEAS ON THE PLACEMENT OF THE UPPER RIDGE AS WELL AS TIMING/INTENSITY OF VARIOUS WAVES RIPPLING THROUGH THE FLOW. GENERALLY DOES APPEAR THERE COULD BE ONE OR TWO BOUTS OF PRECIPITATION BUT WITH TIMING NEXT TO IMPOSSIBLE AT THIS POINT HAVE JUST BLANKETED SEVERAL PERIODS WITH SOME LOW ENDS POPS HEADING INTO NEXT WEEKEND...THOUGH AT THIS DISTANCE IT CERTAINLY IS NOT LOOKING LIKE A WASH OUT. IZZI && .FIRE WEATHER... 255 PM CDT WILL NEED TO MONITOR WEDNESDAY FOR A POTENTIAL HEIGHTENED FIRE DANGER. STRONG WEST WINDS AND DEEP MIXING WILL TAKE PLACE BEHIND A COLD FRONT THAT MOVES THROUGH TUESDAY NIGHT. STILL A LOT OF UNCERTAINTY REGARDING HOW QUICKLY THE COOLER AIR ARRIVES...BUT DOES APPEAR AS THOUGH DEWPOINTS WILL FALL OFF QUICKLY. WILL CONTINUE TO MONITOR TRENDS THE NEXT FEW DAYS. IZZI && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * CIG TRENDS OVERNIGHT * NE WINDS AND GUSTS THROUGH THE MORNING * PRECIP POTENTIAL IN THE MORNING SHEA //DISCUSSION...UPDATED 06Z... EARLY EVENING STRATUS HAS SHIFTED TO THE SOUTH AND AND WEST OF THE EASTERN TERMINALS AS OF 06Z...AND THE TREND OF CIGS RAISING AND OVERALL COVERAGE DECREASING...WILL CONTINUE. 11-3.9UM SATELLITE IMAGERY NOT SHOWING MUCH WITH REGARDS TO LOW CLOUDS ACROSS THE LAKE...WITH THE BULK OF THE LAKE STRATUS STAYING GENERALLY IN THE MKE TO RAC CORRIDOR. THERE ARE SOME HINTS THAT SOME OF THE LOWER CLOUDS MAY LINGER AROUND THE UGN/PWK AND MAYBE ORD TERMINALS THROUGH ABOUT 10Z...AND WITH THE UNCERTAINTY...WILL MAINTAIN THE TEMPO...BUT RAISE HEIGHTS. THROUGH THE REST OF THE NIGHT AND INTO THE DAY TOMORROW...WINDS WILL GRADUALLY WORK THEIR WAY AROUND THE COMPASS...GOING FROM NE TO E AND EVENTUALLY SE-SSE LATE TOMORROW NIGHT. GUSTS WILL ALSO BE ON THE DOWN TREND INTO THE MORNING HOURS...AND WILL HOLD OUT ON THE LOW 20S TO UPPER TEENS GUSTS THROUGH THE 18Z HOUR. PRECIP CHANCES WILL BE TRICKIEST FOR RFD THIS MORNING. GUIDANCE IS BRINGING SHOWERS THAT ARE CURRENTLY WEST OF LSE...SOUTHEAST AND ACROSS RFD INTO THE 12Z HOUR. RAW EXTRAPOLATION FROM RADAR IS A LITTLE CLOSER TO 11Z...BUT ONE THING THE MODELS MAY BE STRUGGLING WITH IS HOW DRY THE AIRMASS MOVING IN FROM THE NORTH ACTUALLY IS. NOT FULLY CONFIDENT THAT THE SHOWERS WILL LAST BEFORE FALLING APART...AND WILL ADD A PERIOD OF VCSH FROM 11 TO 15Z DUE TO THE UNCERTAINTY AT THIS POINT. CONFIDENCE IS MUCH HIGHER THAT ORD/MDW WILL REMAIN DRY...THOUGH THE 03Z HRRR IS REALLY INCREASING THE SHOWERS. WILL NEED TO MONITOR AND ADJUST AS NECESSARY. SHEA //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MODERATE TO HIGH CONFIDENCE ON CIG TRENDS * LOW CONFIDENCE ON BASES FALLING BELOW 015 OVER THE NEXT FEW HOURS * HIGH CONFIDENCE WITH WIND FORECAST * HIGH CONFIDENCE WITH ORD/MDW STAYING DRY THIS MORNING SHEA //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 06Z... * TUESDAY...GUSTY SOUTHERLY WINDS. A SLIGHT CHC OF TSRA FROM MID AFTN INTO THE EVE. LLWS POTENTIAL IN THE EVENING AND EARLY OVERNIGHT. * WEDNESDAY...MVFR POSSIBLE DURING THE NIGHT. * THURSDAY...VFR. * FRIDAY...CHC OF TSRA. * SATURDAY...CHC OF TSRA. SHEA && .MARINE... 247 PM CDT DENSE FOG AND GALE POTENTIAL TUESDAY ARE THE MAIN FORECAST CONCERNS THIS AFTERNOON. AREAS OF DENSE FOG CONTINUE ACROSS SOUTHERN LAKE MICHIGAN THIS AFTERNOON BUT ARE EXPECTED TO DISSIPATE INTO EARLY EVENING. OTHERWISE...TWO AREAS OF LOW PRESSURE...ONE ACROSS EASTER QUEBEC...AND ANOTHER OFF THE EASTERN SEABOARD...WILL MERGE TO THE EAST OF NOVA SCOTIA MONDAY THEN DEEPEN. MEANWHILE...HIGH PRESSURE IS MOVING INTO WESTERN ONTARIO. THE GRADIENT BETWEEN THE MERGING LOWS AND THE HIGH WILL TIGHTEN ACROSS LAKE MICHIGAN THIS EVENING LEADING TO INCREASING NORTHEASTERLY WINDS ACROSS THE LAKE TONIGHT. EXPECT SPEEDS IN THE 25-30 KT RANGE BY MID/LATE EVENING ACROSS MUCH OF THE LAKE. SPEEDS WILL EASE OFF MONDAY AS THE GRADIENT WEAKENS WITH THE RIDGE AXIS ASSOCIATED WITH THE HIGH CROSSING THE LAKE. WILL CONTINUE WITH THE SMALL CRAFT ADVISORY FROM THIS EVENING INTO MONDAY NIGHT FOR WINDS AND WAVES...THOUGH WINDS SHOULD EASE MONDAY...WAVES WILL CONTINUE TO BE HIGH INTO MONDAY NIGHT. STRONG LOW PRESSURE WILL DEVELOP ACROSS THE NORTHERN HIGH PLAINS MONDAY NIGHT AND MOVE EAST-NORTHEASTWARD TO NORTHERN LAKE SUPERIOR WHILE WEAKENING SLIGHTLY TUESDAY NIGHT. AS A RESULT...WINDS WILL TURN SOUTHEASTERLY MONDAY EVENING AS THE RIDGE MOVES EAST AND THE GRADIENT TIGHTENS AHEAD OF THE APPROACHING LOW. COOLER AIR WILL BE IN PLACE ALOFT WHICH WILL SUPPORT UNSTABLE CONDITIONS ACROSS THE LAKE. AS LOW LEVEL WINDS RAMP UP MIXING WILL BRING HIGHER SPEEDS TO THE LAKE SURFACE AND AM CONTINUING TO SEE GOOD POTENTIAL FOR 35-40 KT GALES FROM EARLY TUESDAY THROUGH MUCH OF THE AFTERNOON. THE TRICKY PART WILL BE ACCOUNTING FOR INCREASING WARM AIR ALOFT DEVELOPING AN INVERSION WHICH WILL LIMIT MIXING. THIS WILL LIKELY RESULT IN DECREASING GUSTS FROM SOUTH TO NORTH FROM TUESDAY AFTERNOON INTO THE EVENING. THE GRADIENT WILL REMAIN TIGHT SO SPEEDS WILL BE ELEVATED BUT PROBABLY BELOW GALE AS THIS OCCURS. THE DIRECTIONS WILL TURN MORE SOUTHERLY THROUGH THE DAY AS WELL. WILL HOIST A GALE WATCH FOR THE OPEN WATERS FROM LATE MONDAY NIGHT THROUGH TUESDAY. WITH THE CURRENT SMALL CRAFT IN EFFECT AND LESSER CONFIDENCE IN GALE CONDITIONS ACROSS THE IL/IN NEARSHORE WATERS WILL KEEP THOSE AREAS FREE OF HEADLINES FOR NOW BUT WILL LIKELY NEED TO AT LEAST EXTEND THE SMALL CRAFT THROUGH MUCH OF TUESDAY. THE LOW WILL CROSS NORTHERN LAKE SUPERIOR TUESDAY NIGHT BRINGING WINDS AROUND TO THE WEST...THEN NORTHWEST THEN NORTH AS ANOTHER AREA OF HIGH PRESSURE APPROACHES FROM THE WEST. WINDS WILL THEN TURN SOUTHEASTERLY INTO FRIDAY AS THE HIGH SHIFTS TO THE EAST. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 4 AM TUESDAY. GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...4 AM TUESDAY TO 7 PM TUESDAY. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1145 PM CDT SUN MAR 25 2012 .DISCUSSION... ISSUED 830 PM CDT SUN MAR 25 2012 QUIET WEATHER ON TAP FOR CENTRAL IL TONIGHT. A COLD FRONT ENTERING NORTHERN IL WILL CONTINUE SOUTHWARD OVERNIGHT AND PASS THROUGH THE AREA BY SUNRISE. ONLY SENSIBLE WEATHER WILL BE AN INCREASE IN CLOUDS AND A WIND SHIFT TO THE EAST. THUNDERSTORMS ARE INCREASING TO THE NORTH OF THE WESTERN EXTENSION OF THE COLD FRONT...WHICH LIES STATIONARY ACROSS NEB. THIS ACTIVITY WILL REMAIN WELL NORTH OF THE AREA OVERNIGHT AND MONDAY. AFTERNOON FORECAST PACKAGE LOOKS GOOD AND DO NOT EXPECT THE NEED FOR CHANGES THEREIN. 04 && .AVIATION... ISSUED 1145 PM CDT SUN MAR 25 2012 COLD FRONT/LAKE BREEZE COMPOSITE BOUNDARY MAKING ITS WAY SOUTHWESTWARD THROUGH NORTHERN IL AND IS NEARING PIA/BMI. MAIN FORECAST CHALLENGE WILL BE IF ANY MVFR CLOUDS DEVELOP AFTER FRONTAL PASSAGE THROUGH SUNRISE. FORECAST SOUNDINGS FROM THE LATEST RUC DO SUPPORT CLOUD STRATOCU DEVELOPMENT AT ABOUT 5K FT FOR ALL TAF SITES...WITH A PERIOD OF 1K-2K FT CLOUDS IN THE 08Z-12Z TIME FRAME FOR ONLY PIA/BMI. ALTHOUGH THE SOUNDINGS DO NOT SHOW MVFR CLOUDS IN THE SPI-DEC-CMI CORRIDOR... WILL GIVE THEM A SCT LAYER AT 2K FT. BROKEN VFR STRATOCU WILL THEN DOMINATE ALL SITES THROUGH AT LEAST 00Z...THEN SOME BREAKUP MAY OCCUR SPI-DEC-CMI. WINDS BEHIND THE FRONT WILL INCREASE FROM THE EAST 14-18 KT AND HOLD UP THROUGH THE PERIOD...WITH GUSTS 25-30 KT DURING THE DAY MONDAY. 04 && .PREV DISCUSSION... ISSUED 300 PM CDT SUN MAR 25 2012 SEVERAL COLD FRONTAL PASSAGES WILL HIGHLIGHT THE FORECAST OVER THE NEXT WEEK. THE FIRST COLD FRONT WILL DROP SOUTH ACROSS CENTRAL IL TONIGHT. THAT WILL SHIFT THE WINDS AROUND TO THE NORTH AND BRING COLDER TEMPS FOR MONDAY. HOWEVER...HIGHS ON TUES WILL JUMP 10-12 DEG AS THE FRONT RETURNS NORTH AS A WARM FRONT. THE SECOND COLD FRONT WILL ARRIVE ON WED WITH A COOLER DAY ON THURSDAY. THE TIMING OF THE THIRD COLD FRONT IS A BIT IN QUESTION...BUT IT APPEARS THAT IT WILL ARRIVE EITHER SATURDAY OR SAT NIGHT. PRECIP CHANCES WILL INCREASE DURING THE FRONTAL PASSAGES...WHICH MEANS WE HAVE SEVERAL DAYS WITH A MENTION OF SHOWERS AND STORMS. SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT. THE DIURNAL CU FIELD SHOULD DISSIPATE TOWARD SUNSET...EXCEPT FOR IN OUR SOUTHEAST AREAS WHERE THE CU FIELD APPEARS MORE SYNOPTICALLY DRIVEN. AS THE COLD FRONT DROPS SOUTH ACROSS OUR COUNTIES TONIGHT... IT WILL BRING SOME LOWER DEWPOINT AIR WITH IT. HOWEVER...AS TEMPS DROP BEFORE THE DRY AIR ARRIVES, CAN NOT RULE OUT SOME PATCHY FOG AGAIN OVERNIGHT. CLOUDS ARE EXPECTED TO OVERSPREAD THE AREA FROM NW TO SE...SO THAT SHOULD PREVENT ANY DENSE FOG. MONDAY WILL CLOUDY AND COOLER CONDITIONS AS RAIN SHOWERS ADVANCE TOWARD IL ACROSS IOWA. HOWEVER...THE EASTWARD PROGRESSION OF RAIN WILL STALL OUT IN IOWA MON/MON NIGHT. WE SHOULD REMAIN DRY UNTIL LATER TUESDAY AFTERNOON AND TUESDAY NIGHT, AFTER A WARM FRONT LIFTS NORTHEAST ACROSS C IL. TUESDAY HIGHS WILL REBOUND ABOUT 10 DEGREES WARMER THAN MONDAY BEHIND THAT WARM FRONT. SHOWERS AND A FEW THUNDERSTORMS WILL INCREASE IN COVERAGE TUESDAY NIGHT...AS A BAND OF PRECIP ACCOMPANIES THE NEXT COLD FRONT MOVING SE ACROSS THE AREA. LONG TERM...WEDNESDAY THROUGH SUNDAY. THE COLD AIR WILL LAG A BIT ON WEDNESDAY...SO HIGHS ACROSS THE SOUTH MAY REACH THE MID 70S AGAIN...BUT NORTHERN AREAS MAY BE HELD DOWN IN THE UPPER 60S WITH FALLING TEMPS IN THE AFTERNOON. THURSDAY WILL BE OUR NEXT COOL DAY...AS HIGHS DROP 10-12 DEG BELOW WED HIGHS...WITH READINGS IN THE UPPER 50S NORTHEAST TO MID 60S SOUTHWEST. THE COLDEST AIR WILL REMAIN OFF TO OUR NORTHEAST. AS FOR THE FAR EXTENDED...THE ECMWF AND CANADIAN ARE STRONGER WITH THE LEADING CLIPPER LIKE SYSTEM FOR FRIDAY THAN THE GFS. THEN GFS BRINGS A COLD FRONT ON SATURDAY...WHILE THE ECMWF HOLDS IT OFF UNTIL LATE SATURDAY INTO SATURDAY NIGHT. STORMS WILL ACCOMPANY BOTH SYSTEMS...AS DYNAMICS LOOK FAVORABLE FOR STRONG UPDRAFTS. DRY WEATHER SHOULD RETURN SUNDAY AS COLD AIR PASSES BY JUST TO OUR NORTHEAST ONCE AGAIN. SHIMON && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1153 PM CDT SUN MAR 25 2012 .AVIATION... CIGS EXPECTED TO LOWER INTO MVFR RANGE OVRNGT AND MON MORNING AS COLD MOIST AIR ADVECTS IN FROM LAKE MICHIGAN. POTENTIAL EXISTS FOR IFR CIGS ESPECIALLY NEAR MISSISSIPPI RVR TOWARD DAYBREAK AND THROUGH MID AM MON ALONG WITH PATCHY FOG AND DRIZZLE WITH VSBYS 2-6SM. AREA OF SHOWERS OVER MN WILL DRIFT E/SE AND MAY AFFECT PORTIONS OF NE IA AND ESPECIALLY NW IL LATE TNGT THROUGH MON AM. DBQ TERMINAL LOOKS TO BE ON THE EDGE OF FORCING AND HAVE GONE WITH VCSH FOR NOW AND LET LATER SHIFTS ADJUST AS NEEDED. WINDS WILL SHIFT TO THE EAST AND INCREASE TO 15-20 KTS WITH HIGHER GUSTS AROUND 25 KTS OVRNGT AND REMAIN SO THROUGH REST OF TAF CYCLE. EXPECT CIGS TO CLIMB INTO VFR DURING THE AFTN AND REMAIN VFR THROUGH MON EVE. && .PREV DISCUSSION... /ISSUED 950 PM CDT SUN MAR 25 2012/ UPDATE... AREA OF SHOWERS AND ISOLD TSTMS OVER WESTERN MN OCCURRING IN ZONE OF ELEVATED WARM ADVECTION AND THETA-E CONVERGENCE IN 850-700 MB LAYERS. 00Z NAM SHOWS WARM ADVECTION AND THETA-E CONVERGENCE INCREASING OVRNGT IN AREAS MAINLY N/NE OF QUAD CITIES. SOME OF THE MOST RECENT RUNS OF HRRR AND RUC BACKUP MODELS HAVE BEEN SHOWING PCPN COMING INTO NORTH... ALBEIT SLOW ON TRENDS. HAVE GONE AHEAD AND ADDED POPS TO AREAS NORTH OF QUAD CITIES OVRNGT AND MADE SOME ADJUSTMENTS TO POPS MON. UPDATED GRIDS AND ZFP OUT SHORTLY. && PREV DISCUSSION... /ISSUED 311 PM CDT SUN MAR 25 2012/ SYNOPSIS... THE MORNING UA ANALYSIS HAD AN UPPER RIDGE OVER THE PLAINS WITH A S/W OVER LAKE SUPERIOR. THE COLD FRONT TRAILING THE S/W WAS NOT EVIDENT IN THE SURFACE WIND/PRESSURE FIELDS AT 18Z HOWEVER THERE WAS A NICE THERMAL GRADIENT ALONG THE SOUTHERN EDGE OF THE TRAILING NORTHERN PLAINS HIGH PRESSURE RIDGE. THE 18Z ANALYSIS SHOWED 70 PLUS TEMPS AS FAR NORTH AS KDBQ AND TEMPS AROUND 60 IN NORTHEAST IA AND SOURTHEASTERN MN. SHORT TERM...TONIGHT AND MONDAY... THE LOW LEVEL FLOW WILL TURN MORE EASTERLY OVERNIGHT AS THE NORTHERN PLAINS SURFACE RIDGE SLIDES SOUTHEAST INTO THE GREAT LAKES. THE EASTERLY FLOW WILL BRING MUCH COOLER AIR INTO THE REGION FOR LATE TONIGHT AND MONDAY. EXPECT CLOUDS TO INCREASE LATE THIS EVENING AND OVERNIGHT AS LOW LEVELS COOL AND SATURATE. MID CLOUDS WILL ALSO SPREAD OVER THE AREA AFTER MIDNIGHT WITH INCREASING MID LEVEL WAA. FORCING OVERNIGHT DOES NOT LOOK THAT STRONG SO KEPT THE FORECAST DRY. THERE IS SOME POTENTIAL FOR DRIZZLE WITH THE ARRIVAL OF THE MOIST LOW LEVEL AIR OFF LAKE MI...BUT FORECAST SOUNDINGS WERE SHOWING A FAIRLY DEEP SATURATED LAYER WHICH ISN/T FAVORABLE FOR DRIZZLE. SOME LOW POPS WERE INCLUDED FOR MONDAY WHEN LOW AND MID LEVEL FGEN SPREADS SOUTHEAST THROUGH NORTHEASTERN CWFA. LOWS TONIGHT WILL BE CONSIDERABLY COLDER THAN WHAT THE REGION HAS EXPERIENCED THE LAST COUPLE OF WEEKS WITH MID TO UPPER 30S EXPECTED IN THE NORTHEASTERN CWFA. IT/S QUESTIONABLE IF THE COLDER AIR WILL REACH THE SOUTHWEST CWFA BY MORNING SO KEPT MINS THERE IN THE LOWER 50S. MONDAY TEMPERATURES OVER THE NORTHEASTERN HALF OF THE CWFA WILL NOT REBOUND MUCH WITH STRONG EASTERLY WINDS...CLOUDS AND POSSIBLY SOME RAIN SHOWERS SO KEPT HIGHS IN THE MID 40S WHILE THE SOUTHWEST HAS THE POTENTIAL TO SEE HIGHS IN THE LOW TO MID 60S. ..DLF.. LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY... TUESDAY WILL BE ANOTHER WARM AND BREEZY DAY WITH SCATTERED THUNDERSTORMS ALONG AND AHEAD OF A PASSING COLD FRONT. SLIGHTLY COOLER...BUT CONTINUED ABOVE NORMAL...TEMPERATURES TO THEN FOLLOW THROUGH MUCH OF THE WORKWEEK. RIDGE AT THE SURFACE AND ALOFT WILL FAVOR DRY CONDITIONS...FOLLOWED BY INCREASINGLY UNSETTLED WEATHER FRIDAY THROUGH NEXT WEEKEND AS THE THE UPPER FLOW BECOMES MORE AMPLIFIED. MONDAY NIGHT...VERY STRONG LOW LEVEL JET...WITH 850 WINDS PROGGED FROM 50 TO 70 KTS...IS SHOWN SURGING GULF MOISTURE FROM THE SOUTHERN PLAINS INTO THE UPPER MS VALLEY OUT AHEAD OF LOW PRESSURE DEVELOPING IN THE NORTHERN PLAINS. WHILE THIS IS DIRECTED WELL TO OUR WEST...THERE REMAINS A LOW POTENTIAL FOR STRAY ELEVATED WARM AIR ADVECTION SHOWERS OVER THE ESPECIALLY THE NORTHERN HALF OF THE FORECAST AREA...AND ALSO POSSIBLY OF MORE ORGANIZED SHOWERS OR AN ISOLATED THUNDERSTORMS ON THE EDGE OF THE STEEPER MID LEVEL LAPSE RATES TO OUR WEST TO WANDER INTO EASTERN IA TOWARD MORNING. WILL KEEP SLIGHT TO LOW CHANCE POPS ACROSS THE NORTH TO COVER THIS. OTHERWISE...THE DEEPENING LOW OVER THE NORTHERN PLAINS WILL PROVIDE A TIGHTENING PRESSURE GRADIENT AND BRISK SOUTHEAST TO SOUTH WINDS OVERNIGHT UNDER MOSTLY CLOUDY SKIES. UNTIL A SOMEWHAT DIFFUSE SURFACE WARM FRONT DEVELOPS AND SPREADS NORTHEAST INTO THE FORECAST AREA TOWARD MORNING...THE RELATIVELY DRY LOW LEVEL SOUTHEAST FLOW OUT OF THE RIDGE WILL HOLD TEMPERATURES IN THE 40S NORTH TO LOWER 50S SOUTH THROUGH THE NIGHT. TUESDAY...THE ASSOCIATED COLD FRONT SWEEPS THROUGH FROM LATE MORNING THROUGH MID AFTERNOON. LATEST MODELS DEPICT A GREAT DEAL OF MOISTURE AT OR BELOW 850 MB AND HAVE GONE WITH MOSTLY CLOUDY SKIES. EVEN WITH THE CLOUD COVER...LOW LEVEL WARM ADVECTION ON 15 TO 25 MPH SOUTH WINDS AHEAD OF THE FRONT SHOULD RESULT IN HIGHS WELL INTO THE 70S OVER ALL BUT THE FAR NORTHEAST. THIS WARMING...COMBINED WITH DEWPOINTS PUSHING INTO THE UPPER 50S IS SHOWN BY THE NAM RESULTING IN MUCAPES IN THE RANGE OF 1000 TO 1500 J/KG. THIS...COMBINED WITH 30 TO 40 KTS OF SURFACE TO 6 KM SPEED SHEAR WITH VEERING PROFILES... MAY BE FAVORABLE FOR A FEW LOW END SEVERE STORMS...ESPECIALLY ALONG AND EAST OF THE MS RIVER IN THE AFTERNOON...AND THE CURRENT SPC DAY 3 OUTLOOK HAS A SLIGHT RISK OVER OUR SE COUNTIES. ANTICIPATED COVERAGE OF SHOWERS AND THUNDERSTORMS SUPPORTS POPS IN A 30 TO 40 PERCENT RANGE. THE BACK EDGE OF ANY SHOWERS ALONG TO BEHIND THE FRONT MAY BE ON-GOING AT 00Z OVER THE FAR EAST AND WILL KEEP SLIGHT CHANCES GOING THERE INTO TUE EVENING. UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE PROVIDES DRY WEATHER WITH TEMPERATURES STILL ROUGHLY 10 DEGREES ABOVE NORMAL FOR WED INTO THU. WED NIGHT MAY SEE LOWS IN THE UPPER 30S IN THE FAR NORTH AS THE RIDGE AXIS PASSES OVERHEAD. THE COLDEST MOS GUIDANCE...THE MEN FROM THE 00Z RUN...INDICATES POCKETS OF MID 30S OVER EAST CENTRAL IA INTO NW IL. WILL CONTINUE TO WATCH THIS TREND...BUT HAVE KEPT TEMPERATURES CLOSER TO A CONSENSUS FOR NOW WITH MINS FROM THE UPPER 30S ALONG THE HIGHWAY 20 CORRIDOR TO THE MID 40S ACROSS THE SOUTH. POPS RETURN TO THE FORECAST FOR RAIN AND THUNDERSTORM CHANCES THU NIGHT INTO FRIDAY AS A WEAK SHORTWAVE TROUGH IS SHOWN SENDING A WEAK SURFACE LOW THROUGH KS TO CENTRAL IL. FORECAST CONFIDENCE REMAINS LOW BEYOND AS THERE CONTINUE TO BE SIGNIFICANT DIFFERENCES IN HOW THE MEDIUM RANGE MODELS HANDLE ENSUING SHORTWAVES...RESULTING IN AN EXTENDED PERIOD OF LOW END CHANCE POPS FRIDAY THROUGH SUNDAY THAT WILL LIKELY BECOME DEFINED IN LATER FORECASTS. ..SHEETS.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
150 AM MDT MON MAR 26 2012 .SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT) ISSUED AT 143 AM MDT MON MAR 26 2012 03Z WATER IMAGERY INDICATED LARGE UPPER LEVEL RIDGE IN PLACE ACROSS THE PLAINS WITH SHORT WAVE TROUGH/CLOSED LOW CIRCULATION ENTERING SOUTHERN CALIFORNIA. AT THE SFC...AREA OF LOW PRESSURE WAS IN PLACE ACROSS SOUTHEAST COLORADO IN A SIMILAR POSITION FROM 24 HOURS AGO...WITH LIGHT EASTERLY FLOW ACROSS NORTHERN HALF OF THE AREA. 00Z RAOBS INDICATED A SHARP CHANGE IN MOISTURE CONTENT FROM WEST TO EAST ACROSS THE PLAINS WITH FAIRLY LARGE INCREASES IN MOISTURE BELOW H75 NOTED AT KDDC AND KLBF FROM 24 HOURS AGO...AS EVIDENCED BY +0.3 CHANGE IN PRECIPITABLE WATER OVER THAT TIME. ASIDE FROM OVERNIGHT FOG AND VERY SMALL THUNDERSTORM CHANCES...MAIN FORECAST CONCERNS WILL BE WINDS/FIRE WX AND THUNDERSTORM CHANCES TODAY AND TONIGHT. TODAY-TONIGHT...ALTHOUGH SOME ELEVATED INSTABILITY WILL LINGER AROUND DURING THE MORNING HOURS WITH LATEST RUNS OF HRRR TRYING TO BREAK OUT SOME WEAK CONVECTION AROUND 12Z...ISENTROPIC FIELDS SUGGEST BULK OF FORCING ALONG NOSE OF LLJ WILL BE WELL TO THE NORTH AND EAST OF THE CWA AND WITH CONDENSATION DEFICITS IN EXCESS OF 130 MB...SEEMS DOUBTFUL ANY MORNING INSTABILITY WOULD BE REALIZED AND THINK BULK OF MORNING WX CONCERNS WILL CENTER AROUND ANY LINGERING FOG AROUND SUNRISE. WITH WINDS SHIFTING AROUND TO THE SOUTHWEST AND INCREASING DO NOT THINK FOG WILL BE AS WIDESPREAD OR DENSE LIKE YESTERDAY...BUT WILL MONITOR OBSERVATIONS CLOSELY AND ADJUST AS TRENDS DICTATE. BEST...ALBEIT SMALL...CHANCE FOR PRECIP WILL BE BETWEEN 21 AND 03Z AS CONVERGENCE ALONG DRYLINE REALLY BEGINS TO SHARPEN AND LOW LEVEL FRONTOGENESIS INCREASES. AREA WILL STILL BE PRETTY FAR REMOVED FROM LARGE SCALE FORCING FOR ASCENT AS UPPER TROUGH PASSES ACROSS WYOMING AND WITH STRONG CAP/CINH IN PLACE HAVE DOUBTS ABOUT CONVECTIVE INITIATION AND IF STORMS WOULD ACTUALLY SURVIVE FOR VERY LONG AS THEY MOVED AWAY FROM SFC FORCING. STILL FEEL SMALL POPS WARRANTED AND GIVEN SHEAR/INSTABILITY PROFILES THERE IS A SMALL CHANCE FOR AN ORGANIZED STORM OR TWO AS THINGS INITIATE NEAR THE KS/CO BORDER AND GRADUALLY SHIFT EAST IN THE EVENING. WITH THE RATHER SMALL PROBABILITIES FOR THUNDERSTORMS...WINDS AND FIRE WX WILL CONTINUE TO BE THE MAIN CONCERN FOR THE PERIOD AS WINDS WILL INCREASE RAPIDLY DURING THE AFTERNOON IN RESPONSE TO STRENGTHENING LOW ACROSS THE NEBRASKA PANHANDLE. WINDS SHOULD PRETTY EASILY MEET ADVISORY CONDITIONS ACROSS THE ENTIRE AREA...BUT HAVE A FEW CONCERNS THAT HIGHER GUSTS APPROACHING WARNING CRITERIA MAY OCCUR WITH THE MUCH DEEPER MIXING EXPECTED TO THE WEST OF DRYLINE. OPERATIONAL GUIDANCE NOT REALLY GIVING A SOLID CONSENSUS IN THIS REGARD AND WITH MIXED LAYER DATA GENERALLY TOPPING AT AROUND 48 KTS AND A WEAKER SFC LOW THAN LAST WEEK...THINK CONFIDENCE TOO LOW TO UPGRADE ADVISORY TO WARNING AT THIS POINT. FOR FIRE WEATHER CONDITIONS...THINK DRY LINE WILL HUG KS/CO BORDER FOR MUCH OF THE DAY AS STRONG PRESSURE FALLS OCCUR TO THE NORTHEAST. HOWEVER AS LOW BEGINS TO LIFT INTO THE NEBRASKA PANHANDLE...EXPECT DRYLINE TO START ADVANCING EASTWARD. IT WILL BE MARGINAL FROM A DURATION ASPECT...BUT FEEL UPGRADING FIRE WEATHER WATCH TO WARNING IS APPROPRIATE. TUESDAY...FRONTAL ZONE WILL STALL ACROSS SOUTHERN KANSAS DURING THE MORNING HOURS AS COOLER AIR SETTLES OVER THE AREA WITH ADVANCING SFC RIDGE. WITH A MORE STABLE AIRMASS SETTLING OVER THE AREA AND SHORT WAVE RIDGING STARTING TO DEVELOP...EXPECT DRY CONDITIONS AND GENERALLY CLEAR SKIES. ONLY SIG WEATHER CONCERN WILL BE MAGNITUDE OF DRY AIR THAT WILL BE ADVECTED INTO AREA BEHIND FRONT. ALTHOUGH AFTERNOON HUMIDITIES WILL FALL TO AROUND 15 PERCENT...POSITION OF SFC HIGH WILL LIKELY BRING LIGHT/VARIABLE WINDS TO MUCH OF THE AREA MITIGATING THE FIRE WX THREAT. COULD POSSIBLY SEE STRONGER WINDS ACROSS NEBRASKA COUNTIES...BUT THINK WITH CURRENT FIRE HIGHLIGHTS AND OVERALL LOW CONFIDENCE IN STRONGER WINDS DO NOT FEEL WATCH WARRANTED AT THIS TIME. TUESDAY NIGHT-WEDNESDAY NIGHT...SLOWLY RETREATING FRONTAL ZONE WILL LIKELY BE MAIN CONCERN FOR THE PERIOD AS NOT ONLY WILL THIS FEATURE PROVIDE A POTENTIAL FOCUS FOR THUNDERSTORM DEVELOPMENT...IT WILL ALSO BRING MUCH MORE HUMID AIR BACK TO THE CWA. GIVEN CWA WILL GENERALLY BE UNDER A FAIRLY WEAK SHORT WAVE RIDGE FOR MOST OF THE PERIOD...HAVE DOUBTS THAT FRONT WILL MAKE A RAPID NORTHERLY SURGE AND PREFER THE MORE SOUTHERLY SOLUTION GIVEN BY NAM AND LATEST ENSEMBLE MEANS. IF THERE IS A CHANCE FOR PRECIPITATION THIS PERIOD...THINK MOST LIKELY PERIOD WILL BE OVERNIGHT WEDNESDAY AS LLJ INCREASES THROUGH 06Z IN RESPONSE TO SHORT WAVE TROUGH MOVING ACROSS NORTHERN ROCKIES. NOT ONLY WILL THIS BRING A STRONG SURGE OF MOISTURE/INSTABILITY INTO AREA...BUT ISENTROPIC SURFACES SUGGEST FORCING WILL BE FOCUSED ACROSS EASTERN CWA DURING THE EVENING/OVERNIGHT HOURS. STILL A LOT OF CONCERNS ABOUT WHETHER OR NOT PARCELS WILL SATURATE AND INSTABILITY BE REALIZED...BUT THINK A SMALL THREAT FOR STORMS IS WARRANTED. IN ADDITION TO PRECIP POTENTIAL...INCREASING LOW LEVEL MOISTURE BOTH NIGHTS WILL LIKELY PROVIDE A FAVORABLE ENVIRONMENT FOR FOG FORMATION. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 1254 AM MDT MON MAR 26 2012 ZONAL FLOW WILL BE IN PLACE ACROSS THE CONUS TO START THIS PERIOD. WEAK SHORTWAVE TROUGHS WILL BE MOVING ACROSS THE CENTRAL ROCKIES AND ADJACENT PLAINS BOTH THURSDAY AND FRIDAY. APPEARS THERE WILL BE AT LEAST SOME MOISTURE AVAILABLE AND COUPLED WITH WEAK INSTABILITY WILL CARRY SLIGHT TO LOW CHANCE POPS FOR AFTERNOON/EVENING THUNDERSTORMS BOTH DAYS. UPPER RIDGE WILL BUILD ACROSS THE PLAINS FOR THE REMAINDER OF THE PERIOD AHEAD OF STRONG SYSTEM DIGGING INTO THE FOUR CORNERS. MODEL SOLUTIONS DIVERGE ON HOW TO HANDLE THAT SYSTEM VERY LATE IN THE PERIOD...SO WILL NOT CARRY ANY MENTION OF PRECIPITATION ATTM. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE ENTIRE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1145 PM MDT SUN MAR 25 2012 LOT OF CHANGES/THINGS TO CONSIDER FOR THIS SET OF TAFS. BEFORE THE STRONGER WINDS DEVELOP...IFR/MVFR CEILINGS/VISIBILITIES EXPECTED AT KMCK. BY 14Z VFR CONDITIONS ARE EXPECTED TO RETURN TO KMCK. SOUTHERLY WINDS ARE THEN EXPECTED TO INCREASE INTO THE AFTERNOON WITH SUSTAINED NEAR 30 KNOTS AND GUSTS NEAR OR ABOVE 40 KNOTS. AS HAS BEEN THE CASE RECENTLY DUE TO THE DRY CONDITIONS...EXPECT SOME BLOWING DUST TO REDUCE VISIBILITIES...MAINLY AT KGLD...INTO THE MVFR CATEGORY. ISOLATED THUNDERSTORMS ARE EXPECTED IN THE AFTERNOON TO EARLY EVENING. SINCE THIS FALLS DURING THE LATER HALF OF THE PERIOD AND UNCERTAINTY IN REGARDS TO TIMING/AREA OF INITIATION...CHOSE TO HANDLE WITH ONLY A CB MENTION AT THIS TIME. && .FIRE WEATHER... ISSUED AT 143 AM MDT MON MAR 26 2012 CRITICAL TO EXTREMELY CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY...MAINLY ALONG AND WEST OF THE KANSAS AND COLORADO STATE LINE AS A DRYLINE SLOWLY ADVANCES TO THE EAST TODAY. STRONG SOUTHERLY WINDS OF 25 TO 35 MPH WITH GUSTS TO AROUND 55 MPH WILL COMBINE WITH HUMIDITIES AROUND 10 PERCENT DURING THE AFTERNOON AND EARLY EVENING HOURS. A COLD FRONT WILL BEGIN TO MOVE ACROSS THE AREA TONIGHT...BRINGING A SUDDEN SHIFT IN THE WINDS AND A BRIEF PERIOD OF STRONG NORTHWESTERLY WINDS. A VERY DRY AIR MASS WILL SETTLE OVER THE AREA ON TUESDAY BRINGING HUMIDITIES DOWN TO AROUND 15 PERCENT DURING THE AFTERNOON. WHILE WINDS WILL BE LIGHT AND VARIABLE ACROSS MUCH OF THE AREA...THERE IS POTENTIAL FOR STRONGER WINDS AND CRITICAL FIRE WEATHER CONDITIONS ACROSS SOUTHWEST NEBRASKA. IF WINDS DO OCCUR...WILL LIKELY BE A MUCH SMALLER MAGNITUDE OF EVENT THAN TODAY AND CHOSE TO NOT ISSUE A FIRE WEATHER WATCH TO AVOID CONFUSION ABOUT TODAYS WARNING. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR COZ252>254. WIND ADVISORY FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR COZ090>092. KS...RED FLAG WARNING FROM NOON MDT /1 PM CDT/ TODAY TO 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ001-013-027-041. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TODAY TO 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ001>004-013>016-027>029-041-042. NE...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR NEZ079. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TODAY TO 9 PM MDT /10 PM CDT/ THIS EVENING FOR NEZ079>081. && $$ SHORT TERM...JRM LONG TERM....024 AVIATION...BULLER FIRE WEATHER...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
100 AM MDT MON MAR 26 2012 .UPDATE... ISSUED AT 836 PM MDT SUN MAR 25 2012 JUST COMPLETED ANOTHER UPDATE. BASED ON CURRENT SATELLITE AND EXPECTED MID/UPPER LEVEL CLOUD COVER AND LOW LEVEL STRATUS...INCREASED CLOUD COVER ONCE AGAIN. ALSO DEWPOINTS ARE RUNNING HIGHER THAN CURRENTLY PROGGED. LOOKS LIKE WINDS WILL SHIFT UNTIL LATER IN THE NIGHT PER THE RUC WHICH HAS A GOOD HANDLE ON THE CURRENT WIND AND DEWPOINT FIELD...ALTHOUGH NOT AS GOOD ON THE DEWPOINTS. SO USED IT FOR THE BASIS OF THE UPDATE. AS A RESULT OF A LONGER PERIOD OF EASTERLY FLOW AND HIGHER DEWPOINTS...INCREASED COVERAGE OF FOG ONCE AGAIN TO AREAS OVER THE NORTHERN PORTION OF THE AREA. AT THIS TIME BASED ON THE THICK MID/UPPER LEVEL CLOUD COVER...DO NOT EXPECT THE FOG TO BECOME DENSE BUT THIS WILL NEED CONTINUED MONITORING. UPDATE ISSUED AT 546 PM MDT SUN MAR 25 2012 JUST COMPLETED A MINOR UPDATE. A GREAT DEAL OF MID/HIGH LEVEL CLOUD COVER MOVING OVER THE AREA IN ADVANCE OF WESTERN UPPER TROUGH. MOISTURE PROGS WOULD INDICATE THAT THIS CLOUD COVER WILL STAY AS THICK AS IT IS NOW OR GET THICKER. SO INCREASED CLOUD COVER THROUGH THE NIGHT. BASED ON LATEST OBSERVATIONS AND MODEL DATA...EXPANDED THE PATCHY FOG AREA TO THE NORTH AND WEST. EVEN THOUGH LOW LEVEL MOISTURE LOOKS TO BE GREATER THAN LAST NIGHT... THE HIGHER LEVEL CLOUD COVER AND INCREASE/VEERING OF THE WIND OVERNIGHT SHOULD LIMIT THE COVERAGE OF THE FOG AND CHANCES THAT IT WILL BE DENSE. WILL CONTINUE TO CLOSELY WATCH TRENDS ON THIS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 308 PM MDT SUN MAR 25 2012 MOIST AIR MASS CONTINUES TO RESIDE OVER THE TRI-STATE REGION THIS AFTERNOON AHEAD OF A TROUGH WHICH IS CURRENTLY SITUATED OVER THE PACIFIC COAST. PRIMARY QUESTION FOR TONIGHT IS WHETHER FOG WILL REFORM ACROSS THE AREA. GUIDANCE IS DEPICTING ANYTHING BUT A CONSENSUS WITH RUC MORE WIDESPREAD THAN MOST OTHER GUIDANCE. WILL CONTINUE WITH PATCHY FOG MENTION OVER THE NORTHEAST BUT EVENING SHIFT WILL NEED TO MONITOR SITUATION CLOSELY. FOCUS THEN SHIFTS TO AN ACTIVE WEATHER DAY ON MONDAY WITH A MULTITUDE OF HAZARDS POSSIBLE ACROSS THE AREA. CONFIDENCE IN CRITICAL FIRE WEATHER CONDITIONS IS HIGHEST ACROSS EASTERN COLORADO. SEE FIRE WEATHER SECTION BELOW FOR FURTHER DISCUSSION ON THAT POTENTIAL. WESTERN CONUS TROUGH WILL BEGIN TO TRANSLATE EASTWARD WITH A SHORTWAVE TROUGH LIFTING NORTHEASTWARD INTO THE WESTERN DAKOTAS BY MONDAY EVENING. A DRYLINE WILL BECOME ESTABLISHED OVER EASTERN COLORADO DURING THE LATE MORNING HOURS BUT DOES NOT REALLY MIX EAST OF THE CO/KS BORDER UNTIL LATE MONDAY EVENING. PRESSURE GRADIENT WILL TIGHTEN RAPIDLY AS THE LOW BEGINS TO DEEPEN RESULTING IN ADVISORY CRITERIA WINDS ACROSS THE ENTIRE FORECAST AREA DURING THE AFTERNOON AND EARLY EVENING. HAVE GONE AHEAD AND EXPANDED THE GOING WIND ADVISORY FOR THIS LIKELIHOOD. IN ADDITION TO FIRE WEATHER AND WIND CONCERNS...ALSO HAVE A SMALL CHANCE FOR THUNDERSTORMS TO DEVELOP PRIMARILY ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA. STRONGEST DYNAMIC REMAIN NORTH OF THE FORECAST AREA BUT ENOUGH FORCING FOR ASCENT SHOULD BE OBSERVED FOR A FEW HOUR WINDOW. NOT COMPLETELY CONFIDENT THAT CONVECTION WILL DEVELOP BUT THE ENVIRONMENT WOULD BE SUPPORTIVE OF STRONG THUNDERSTORMS IF AN UPDRAFT CAN DEVELOP AND BE SUSTAINED. A COLD FRONT SWEEPS THROUGH THE AREA BETWEEN 00Z AND 06Z. MAY HAVE A BRIEF PERIOD OF GUSTY NORTHWESTERLY WINDS BEHIND THE FRONT GIVEN ANTICIPATED 6 HOUR PRESSURE RISES AS PROGGED BY BOTH THE NAM AND GFS. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 1254 AM MDT MON MAR 26 2012 ZONAL FLOW WILL BE IN PLACE ACROSS THE CONUS TO START THIS PERIOD. WEAK SHORTWAVE TROUGHS WILL BE MOVING ACROSS THE CENTRAL ROCKIES AND ADJACENT PLAINS BOTH THURSDAY AND FRIDAY. APPEARS THERE WILL BE AT LEAST SOME MOISTURE AVAILABLE AND COUPLED WITH WEAK INSTABILITY WILL CARRY SLIGHT TO LOW CHANCE POPS FOR AFTERNOON/EVENING THUNDERSTORMS BOTH DAYS. UPPER RIDGE WILL BUILD ACROSS THE PLAINS FOR THE REMAINDER OF THE PERIOD AHEAD OF STRONG SYSTEM DIGGING INTO THE FOUR CORNERS. MODEL SOLUTIONS DIVERGE ON HOW TO HANDLE THAT SYSTEM VERY LATE IN THE PERIOD...SO WILL NOT CARRY ANY MENTION OF PRECIPITATION ATTM. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE ENTIRE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1145 PM MDT SUN MAR 25 2012 LOT OF CHANGES/THINGS TO CONSIDER FOR THIS SET OF TAFS. BEFORE THE STRONGER WINDS DEVELOP...IFR/MVFR CEILINGS/VISIBILITIES EXPECTED AT KMCK. BY 14Z VFR CONDITIONS ARE EXPECTED TO RETURN TO KMCK. SOUTHERLY WINDS ARE THEN EXPECTED TO INCREASE INTO THE AFTERNOON WITH SUSTAINED NEAR 30 KNOTS AND GUSTS NEAR OR ABOVE 40 KNOTS. AS HAS BEEN THE CASE RECENTLY DUE TO THE DRY CONDITIONS...EXPECT SOME BLOWING DUST TO REDUCE VISIBILITIES...MAINLY AT KGLD...INTO THE MVFR CATEGORY. ISOLATED THUNDERSTORMS ARE EXPECTED IN THE AFTERNOON TO EARLY EVENING. SINCE THIS FALLS DURING THE LATER HALF OF THE PERIOD AND UNCERTAINTY IN REGARDS TO TIMING/AREA OF INITIATION...CHOSE TO HANDLE WITH ONLY A CB MENTION AT THIS TIME. && .CLIMATE... ISSUED AT 308 PM MDT SUN MAR 25 2012 STILL LOOKING AT THE POTENTIAL FOR A FEW RECORDS ACROSS THE TRI- STATE REGION ON MONDAY. ALSO STILL WELL ON TRACK FOR THE WARMEST MARCH ON RECORD AT GOODLAND...BURLINGTON...AND MCCOOK. HERE ARE THE LATEST FIGURES THROUGH MARCH 24. GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.6 BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 47.1 MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.9 HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 51.1 WITH MUCH ABOVE NORMAL TEMPERATURES PROJECTED TO CONTINUE THROUGH THE END OF THE MONTH...CONFIDENCE IS VERY HIGH THAT GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON RECORD. IT REMAINS TO BE SEE IF HILL CITY WILL BREAK THE RECORD AS WELL. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...WIND ADVISORY FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR COZ090>092. RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR COZ252>254. KS...FIRE WEATHER WATCH FROM NOON MDT /1 PM CDT/ TODAY THROUGH THIS EVENING FOR KSZ001-013-027-041. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TODAY TO 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ001>004-013>016-027>029-041-042. NE...FIRE WEATHER WATCH FROM NOON MDT TODAY THROUGH THIS EVENING FOR NEZ079. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TODAY TO 9 PM MDT /10 PM CDT/ THIS EVENING FOR NEZ079>081. && $$ UPDATE...BULLER SHORT TERM...PMM/FOLTZ LONG TERM....024 AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1151 PM MDT SUN MAR 25 2012 .UPDATE... ISSUED AT 836 PM MDT SUN MAR 25 2012 JUST COMPLETED ANOTHER UPDATE. BASED ON CURRENT SATELLITE AND EXPECTED MID/UPPER LEVEL CLOUD COVER AND LOW LEVEL STRATUS...INCREASED CLOUD COVER ONCE AGAIN. ALSO DEWPOINTS ARE RUNNING HIGHER THAN CURRENTLY PROGGED. LOOKS LIKE WINDS WILL SHIFT UNTIL LATER IN THE NIGHT PER THE RUC WHICH HAS A GOOD HANDLE ON THE CURRENT WIND AND DEWPOINT FIELD...ALTHOUGH NOT AS GOOD ON THE DEWPOINTS. SO USED IT FOR THE BASIS OF THE UPDATE. AS A RESULT OF A LONGER PERIOD OF EASTERLY FLOW AND HIGHER DEWPOINTS...INCREASED COVERAGE OF FOG ONCE AGAIN TO AREAS OVER THE NORTHERN PORTION OF THE AREA. AT THIS TIME BASED ON THE THICK MID/UPPER LEVEL CLOUD COVER...DO NOT EXPECT THE FOG TO BECOME DENSE BUT THIS WILL NEED CONTINUED MONITORING. UPDATE ISSUED AT 546 PM MDT SUN MAR 25 2012 JUST COMPLETED A MINOR UPDATE. A GREAT DEAL OF MID/HIGH LEVEL CLOUD COVER MOVING OVER THE AREA IN ADVANCE OF WESTERN UPPER TROUGH. MOISTURE PROGS WOULD INDICATE THAT THIS CLOUD COVER WILL STAY AS THICK AS IT IS NOW OR GET THICKER. SO INCREASED CLOUD COVER THROUGH THE NIGHT. BASED ON LATEST OBSERVATIONS AND MODEL DATA...EXPANDED THE PATCHY FOG AREA TO THE NORTH AND WEST. EVEN THOUGH LOW LEVEL MOISTURE LOOKS TO BE GREATER THAN LAST NIGHT... THE HIGHER LEVEL CLOUD COVER AND INCREASE/VEERING OF THE WIND OVERNIGHT SHOULD LIMIT THE COVERAGE OF THE FOG AND CHANCES THAT IT WILL BE DENSE. WILL CONTINUE TO CLOSELY WATCH TRENDS ON THIS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 308 PM MDT SUN MAR 25 2012 MOIST AIR MASS CONTINUES TO RESIDE OVER THE TRI-STATE REGION THIS AFTERNOON AHEAD OF A TROUGH WHICH IS CURRENTLY SITUATED OVER THE PACIFIC COAST. PRIMARY QUESTION FOR TONIGHT IS WHETHER FOG WILL REFORM ACROSS THE AREA. GUIDANCE IS DEPICTING ANYTHING BUT A CONSENSUS WITH RUC MORE WIDESPREAD THAN MOST OTHER GUIDANCE. WILL CONTINUE WITH PATCHY FOG MENTION OVER THE NORTHEAST BUT EVENING SHIFT WILL NEED TO MONITOR SITUATION CLOSELY. FOCUS THEN SHIFTS TO AN ACTIVE WEATHER DAY ON MONDAY WITH A MULTITUDE OF HAZARDS POSSIBLE ACROSS THE AREA. CONFIDENCE IN CRITICAL FIRE WEATHER CONDITIONS IS HIGHEST ACROSS EASTERN COLORADO. SEE FIRE WEATHER SECTION BELOW FOR FURTHER DISCUSSION ON THAT POTENTIAL. WESTERN CONUS TROUGH WILL BEGIN TO TRANSLATE EASTWARD WITH A SHORTWAVE TROUGH LIFTING NORTHEASTWARD INTO THE WESTERN DAKOTAS BY MONDAY EVENING. A DRYLINE WILL BECOME ESTABLISHED OVER EASTERN COLORADO DURING THE LATE MORNING HOURS BUT DOES NOT REALLY MIX EAST OF THE CO/KS BORDER UNTIL LATE MONDAY EVENING. PRESSURE GRADIENT WILL TIGHTEN RAPIDLY AS THE LOW BEGINS TO DEEPEN RESULTING IN ADVISORY CRITERIA WINDS ACROSS THE ENTIRE FORECAST AREA DURING THE AFTERNOON AND EARLY EVENING. HAVE GONE AHEAD AND EXPANDED THE GOING WIND ADVISORY FOR THIS LIKELIHOOD. IN ADDITION TO FIRE WEATHER AND WIND CONCERNS...ALSO HAVE A SMALL CHANCE FOR THUNDERSTORMS TO DEVELOP PRIMARILY ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA. STRONGEST DYNAMIC REMAIN NORTH OF THE FORECAST AREA BUT ENOUGH FORCING FOR ASCENT SHOULD BE OBSERVED FOR A FEW HOUR WINDOW. NOT COMPLETELY CONFIDENT THAT CONVECTION WILL DEVELOP BUT THE ENVIRONMENT WOULD BE SUPPORTIVE OF STRONG THUNDERSTORMS IF AN UPDRAFT CAN DEVELOP AND BE SUSTAINED. A COLD FRONT SWEEPS THROUGH THE AREA BETWEEN 00Z AND 06Z. MAY HAVE A BRIEF PERIOD OF GUSTY NORTHWESTERLY WINDS BEHIND THE FRONT GIVEN ANTICIPATED 6 HOUR PRESSURE RISES AS PROGGED BY BOTH THE NAM AND GFS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 308 PM MDT SUN MAR 25 2012 DRY CONDITIONS AND A CONTINUATION OF MUCH ABOVE NORMAL TEMPERATURES WILL CONTINUE FROM TUESDAY THROUGH EARLY THURSDAY AS A BROAD MID/UPPER RIDGE BUILDS BACK ACROSS THE CENTRAL HIGH PLAINS. BY THURSDAY AFTERNOON...FORCING FOR ASCENT ASSOCIATED WITH A SHORTWAVE TROUGH TRANSLATING ACROSS THE DAKOTAS COULD PROVIDE ENOUGH LIFT TO GENERATE CONVECTION ACROSS PRIMARILY NORTHEASTERN PORTIONS OF THE TRI-STATE REGION. ADDITIONAL WEAK SHORTWAVE TROUGHS PASS THROUGH THE AREA THURSDAY NIGHT AND FRIDAY WITH A CONTINUED FOCUS ON EASTERN PORTIONS OF THE AREA. DRY CONDITIONS WILL RETURN FOR THE WEEKEND WITH AFTERNOON TEMPS IN THE MID TO UPPER 70S CONTINUING. SIGNIFICANT FORECAST UNCERTAINTY DEVELOPS BY SUNDAY WITH THE OPERATIONAL GFS/GEFS MEAN AND EC DEPICTING STARKLY DIFFERENT SCENARIOS. THE GFS ATTEMPTS TO DEVELOP A DEEP TROUGH ACROSS THE GREAT BASIN/INTERMOUNTAIN WEST WHILE THE EC SUPPORTS A RIDGE OVER THE SAME GENERAL AREA AND HOLDS THE TROUGH OVER THE PACIFIC NORTHWEST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1145 PM MDT SUN MAR 25 2012 LOT OF CHANGES/THINGS TO CONSIDER FOR THIS SET OF TAFS. BEFORE THE STRONGER WINDS DEVELOP...IFR/MVFR CEILINGS/VISIBILITIES EXPECTED AT KMCK. BY 14Z VFR CONDITIONS ARE EXPECTED TO RETURN TO KMCK. SOUTHERLY WINDS ARE THEN EXPECTED TO INCREASE INTO THE AFTERNOON WITH SUSTAINED NEAR 30 KNOTS AND GUSTS NEAR OR ABOVE 40 KNOTS. AS HAS BEEN THE CASE RECENTLY DUE TO THE DRY CONDITIONS...EXPECT SOME BLOWING DUST TO REDUCE VISIBILITIES...MAINLY AT KGLD...INTO THE MVFR CATEGORY. ISOLATED THUNDERSTORMS ARE EXPECTED IN THE AFTERNOON TO EARLY EVENING. SINCE THIS FALLS DURING THE LATER HALF OF THE PERIOD AND UNCERTAINTY IN REGARDS TO TIMING/AREA OF INITIATION...CHOSE TO HANDLE WITH ONLY A CB MENTION AT THIS TIME. && .FIRE WEATHER... ISSUED AT 308 PM MDT SUN MAR 25 2012 HAVE GONE AHEAD AND UPGRADED THE THREE EASTERN COLORADO COUNTIES TO A RED FLAG WARNING FOR MONDAY. LEFT THE FIRE WEATHER WATCH INTACT FOR THE FIRST TIER OF KANSAS AND NEBRASKA COUNTIES AS THERE IS SIGNIFICANT UNCERTAINTY WITH REGARD TO JUST HOW FAR EAST THE DRYLINE WILL MIX DURING THE AFTERNOON. OPTED TO CANCEL THE FIRE WEATHER WATCH FOR THE NEXT TIER OF COUNTIES TO THE EAST AS CONFIDENCE WAS TOO LOW THAT CRITERIA WOULD BE MET IN THESE LOCATIONS. && .CLIMATE... ISSUED AT 308 PM MDT SUN MAR 25 2012 STILL LOOKING AT THE POTENTIAL FOR A FEW RECORDS ACROSS THE TRI- STATE REGION ON MONDAY. ALSO STILL WELL ON TRACK FOR THE WARMEST MARCH ON RECORD AT GOODLAND...BURLINGTON...AND MCCOOK. HERE ARE THE LATEST FIGURES THROUGH MARCH 24. GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.6 BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 47.1 MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.9 HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 51.1 WITH MUCH ABOVE NORMAL TEMPERATURES PROJECTED TO CONTINUE THROUGH THE END OF THE MONTH...CONFIDENCE IS VERY HIGH THAT GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON RECORD. IT REMAINS TO BE SEE IF HILL CITY WILL BREAK THE RECORD AS WELL. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...WIND ADVISORY FROM NOON TO 9 PM MDT MONDAY FOR COZ090>092. RED FLAG WARNING FROM NOON TO 9 PM MDT MONDAY FOR COZ252>254. KS...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR KSZ001-013-027-041. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TO 9 PM MDT /10 PM CDT/ MONDAY FOR KSZ001>004-013>016-027>029-041-042. NE...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR NEZ079. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TO 9 PM MDT /10 PM CDT/ MONDAY FOR NEZ079>081. && $$ UPDATE...BULLER SHORT TERM...PMM/FOLTZ LONG TERM....FOLTZ AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS JACKSON KY
359 AM EDT MON MAR 26 2012 .UPDATE... ISSUED AT 150 AM EDT MON MAR 26 2012 LOW CLOUDS CONTINUE TO GENERALLY ADVECT FROM NNW TO SSE ACROSS THE CWA AT THIS TIME WITH MORE OF A SOLID BAND ACROSS THE SOUTHERN CWA THAT AT THIS POINT STILL SEEMS TO BE ADVECTION OUT AND THEN SOME MORE PATCHY LOW CLOUDS FURTHER NORTH ACROSS SOUTHERN OH AND PARTS OF CENTRAL AND NORTHEASTERN KY THAT GENERALLY ALSO APPEAR TO BE ADVECTING ACROSS RATHER THAN DEVELOPING FURTHER. A RATHER SUBTLE VORT/ SHORTWAVE WILL BE ROTATING ACROSS THE REGION FOR THE REMAINDER OF THE NIGHT AND THIS WILL PROBABLY AT LEAST TEMPORARILY SLOW DOWN THE ADVECTION OF THE MORE SOLID BAND IN THE SOUTH OUT AND COULD LEAD TO SOME FURTHER DEVELOPMENT OF CURRENTLY MORE SCATTERED LOW CLOUDS WORKING IN FROM THE NNW. THE GRIDS WERE UPDATED TO GENERALLY REFLECT THIS THINKING FOR SKY COVER AND TO ACCOUNT FOR THE RECENT OBS TRENDS TO TEMPS...DEWPOINTS AND WINDS. UPDATE ISSUED AT 1050 PM EDT SUN MAR 25 2012 CLOUD DECK AROUND 4K AGL FEET CURRENTLY ADVECTING SOUTH ACROSS THE FORECAST AREA PER LATEST SATELLITE IMAGERY. BACK EDGE OF THIS CLOUD DECK WILL CLEAR THE NORTHERN PART OF FORECAST AREA BY MIDNIGHT. HOWEVER...WITH CONTINUED NORTHERLY FLOW AND LOW LEVEL MOISTURE AVAILABLE EXPECT UPSLOPE FLOW TO KEEP CLOUDS IN THE SOUTHEAST PART OF FORECAST AREA FOR MOST OF THE NIGHT. THIS IDEA IS SUPPORTED BY LATEST RUC GUIDANCE. HAVE UPDATED NDFD AND ASSOCIATED PRODUCTS PER LATEST SATELLITE AND OBSERVATIONAL DATA. UPDATE ISSUED AT 759 PM EDT SUN MAR 25 2012 THE LAST ISOLATED SHOWERS DISSIPATED OR MOVED OUT OF THE AREA AROUND 730 PM EDT...SO HAVE REMOVED ALL PRECIPITATION FROM THE NDFD AND ASSOCIATED PRODUCTS FOR THE OVERNIGHT PERIOD. ALSO MADE SOME MINOR UPDATES BASED ON LATEST OBSERVATIONAL TRENDS. THE MAIN FORECAST ISSUE IS HOW MUCH CLOUDINESS THERE WILL BE OVERNIGHT. THERE IS CONSIDERABLE LOW CLOUDINESS UPSTREAM OF THE AREA...AND LATEST NAM AND RUC GUIDANCE SHOW CONSIDERABLE LOW LEVEL MOISTURE...MAINLY BELOW 850 MB TO BE OVER THE AREA TONIGHT. WITH NORTHERLY FLOW EXPECT CLOUDINESS TO INCREASE IN COVERAGE DURING THE NIGHT...WITH MOSTLY CLOUDY SKIES BEING THE RESULT. UPDATE ISSUED AT 423 PM EDT SUN MAR 25 2012 BASED ON RADAR TRENDS ISOLATED TO SCATTERED SHOWERS WILL AFFECT FAR EASTERN KENTUCKY THROUGH 23Z. THIS IS CURRENTLY WELL DEPICTED IN NDFD. ONLY SOME MINOR NDFD UPDATES WERE MADE BASED ON LATEST SATELLITE AND SURFACE OBSERVATIONAL TRENDS. && .SHORT TERM...(LATE THIS AFTERNOON THROUGH TUESDAY) ISSUED AT 310 PM EDT SUN MAR 25 2012 UPPER LEVEL LOW WILL CONTINUE TO PULL AWAY FROM THE AREA TONIGHT GIVING WAY TO UPPER LEVEL RIDGING THROUGH THE REMAINDER OF THE PERIOD. THE UPPER LOW WILL REMAIN CLOSE ENOUGH TO KEEP A MENTION OF A FEW SHOWERS IN THE FORECAST FOR MOST AREAS LATE THIS AFTERNOON... WITH THE CHANCE OF SHOWERS LINGERING ACROSS THE TIP OF FAR EAST KENTUCKY THIS EVENING. IT APPEARS THAT INSTABILITY WILL NOT BE SUFFICIENT TO PRODUCE A TSTORM THIS FAR WEST SO REMOVED THAT MENTION FOR THIS AFTERNOON AND EVENING. A COLD FRONT WILL THEN DROP IN FROM THE NORTH LATE TONIGHT KEEPING A LIGHT BREEZE BLOWING FOR MOST LOCATIONS. MOISTURE POOLING ALONG THIS BOUNDARY IN CONJUNCTION WITH THE LIGHT NORTHEAST LOW LEVEL FLOW WILL LIKELY RESULT IN QUITE A BIT OF STRATUS DEVELOPING OVERNIGHT WITH MAYBE EVEN A LITTLE DRIZZLE. ANY CLOUD COVER SHOULD DISSOLVE BY MIDDAY MONDAY AS HIGH PRESSURE BEGINS TO BUILD DOWN INTO THE OHIO VALLEY ACCOMPANIED BY A MUCH DRIER AIRMASS. IN FACT...DEWPOINTS ARE PROGGED TO DROP INTO THE 20S OVER NORTHEAST KENTUCKY LATE MONDAY NIGHT AND THERE IS A CONCERN THAT TEMPERATURES WILL RESPOND TO THIS DRY AIR AND DROP LOW ENOUGH TO THREATEN A FROST OR FREEZE FOR SOME AREAS. CONFIDENCE IS NOT HIGH ENOUGH TO HOIST ANY HEADLINES AT THIS TIME THOUGH AS MODELS INDICATE THE POTENTIAL FOR SOME HIGH LEVEL CLOUDINESS TO MOVE IN OVERNIGHT AND POINT TO THERE BEING JUST ENOUGH WIND TO KEEP ANY FROST FORMATION ISOLATED AND CONFINED TO THE DEEPEST VALLEYS BASICALLY NORTH AND EAST OF JKL. HIGH PRESSURE WILL REMAIN IN CONTROL ON TUESDAY BUT HIGH LEVEL CLOUDS WILL BE ON THE INCREASE IN ADVANCE OF OUR NEXT WEATHER MAKER. TEMPS ARE TRICKY...VARYING 10 TO 15 DEGREES BETWEEN THE GFS AND NAM MOS AT ANY GIVEN POINT. TEND TO AGREE MORE WITH THE GFS NUMBERS WITH THE UPPER LEVEL RIDGE BUILDING IN AND WILL FORECAST HIGHS APPROACHING OR EXCEEDING 70 FOR MOST LOCATIONS. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 359 AM EDT MON MAR 26 2012 THE EXTENDED FORECAST PERIOD BEGINS WEDNESDAY WITH AN ACTIVE PATTERN IN STORE. A RATHER VIGOROUS SHORTWAVE WILL TRACK ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION. AT THE SURFACE...A COLD FRONT MOVES SOUTH AND EAST INTO KENTUCKY. A SURFACE HIGH OVER THE SOUTHEAST WILL IMPEDE THE PROGRESS OF THE FRONT NEARLY SHEARING IT OUT. THE SHORT TERM MODELS ARE IN FAIR AGREEMENT WITH THIS FEATURE AS WELL. WITH THE SLOWED APPROACH OF THE FRONT AND THE DRY ENVIRONMENT ALREADY IN PLACE...FEEL THAT THE NAM HAS A GOOD HANDLE ON THE BULK OF THE PRECIP MOVING INTO THE AREA TOWARDS LATE MORNING AND INTO THE AFTERNOON. MODEL SOUNDINGS STILL INDICATE A FAIR AMOUNT OF INSTABILITY AS MOST OF THE FORCING ARRIVES DURING THE AFTERNOON DURING MAX HEATING. SO WILL PUT THUNDERSTORMS IN WITH THE PRECIP. IT IS STILL UNCLEAR AT THIS POINT IF THERE IS A THREAT FOR SEVERE STORMS AS ALOT OF THE ENERGY SEEMS TO GET LOST OR STAYS NORTH AS THE FRONT MOVES SOUTH. DUE TO THE PROGRESSION OF THE FRONT...A MODEL COMPROMISE HAS PRECIP LASTING A BIT LONGER AS THE FRONT DOESNT EXIT TILL LATE THURSDAY. THIS IS A BIT CONCERNING AS TENDENCY LIES WITH PRECIP HANGING AROUND A BIT LONGER IN THE SOUTHERN COUNTIES BUT WILL LEAVE THIS DECISION WITH SHIFTS A LITTLE CLOSER TO THE EVENT. DRY WEATHER WILL RETURN TO EASTERN KENTUCKY THURSDAY NIGHT AND INTO FRIDAY AS A RIDGE MOVES OVER THE OHIO VALLEY. THIS IS HOWEVER SHORT LIVED AS ANOTHER STRONG WAVE MOVES ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES. THIS IS OCCURRING WHILE ANOTHER WAVE EJECTS OUT OF THE SOUTHWEST AND INTO THE NORTHERN GULF. THIS WILL INJECT A SUFFICIENT MOISTURE FLUX FROM THE GULF INTO THE TN AND OH VALLEYS. ALSO...AT THIS POINT THE GFS AND EURO DO DIVERGE IN THEIR RESPECTIVE SOLUTIONS WITH THE EURO BEING FASTER THAN THE GFS BRINGING PRECIP INTO THE AREA FRIDAY AFTERNOON WHERE THE GFS WAITS TILL FRIDAY NIGHT. A CONSENSUS BETWEEN THE TWO IN THE CR INITIALIZATION HAS SLIGHT CHANCE POPS LATE FRIDAY THEN PROGRESSING THROUGH SO WILL KEEP THIS IN THERE. THROUGH THE REST OF THE WEEKEND...THE DEVELOPING SURFACE BOUNDARY...SUFFICIENT UPPER LEVEL SUPPORT AND STRONG MOISTURE FLUX WILL PRETTY MUCH KEEP SHOWERS AND THUNDERSTORMS IN THE FORECAST. DUE TO THE PROGRESSIVE PATTERN THOUGH...DO NOT EXPECT ANY PROLONGED RAINFALLS. OVERALL...THE LATTER HALF OF THE EXTENDED APPEARS TO BE STILL A BIT MURKY DUE TO THE PROGRESSIVE PATTERN AND THE FLIP FLOPPING OF THE MODELS SO WILL EXUDE A LOW CONFIDENCE ESPECIALLY DAY 6 AND 7. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 150 AM EDT MON MAR 26 2012 MAIN ISSUE OF CONCERN FOR THIS TAF ISSUANCE AND THE FIRST 6 TO 12 HOURS OF THE PERIOD CONTINUES TO BE THE MOVEMENT OF LOW CLOUDS ACROSS THE AREA AND THE POTENTIAL FOR DEVELOPMENT OF LOW CLOUDS ACROSS THE FORECAST AREA DURING THE NEXT 6 TO 9 HRS AS A RATHER SUBTLE SHORTWAVE MOVES ACROSS THE AREA. THERE IS CONSIDERABLE LOW LEVEL CLOUDINESS ACROSS THE SOUTHERN CWA AT THIS TIME AND MORE ISOLATED TO SCATTERED PATCHES OF LOW CLOUDS ADVECTING IN FORM THE NORTH. AT THIS POINT ALL OF THE CLOUDS SEEM TO GENERALLY BE ADVECTING ACROSS THE AREA...BUT THE SHORTWAVE PASSING BY DURING THE NEXT 6 HRS OR SO MAY SLOW DOWN ADVECTION OF THE LOW CLOUDS OUT OF THE SOUTH AND POSSIBLE LEAD TO FURTHER DEVELOPMENT OF THE BANDS WORKING IN FROM THE NORTH AS THE MOVE ACROSS THE JKL CWA. AT THIS POINT...NAMBUFR SOUNDINGS SEEM TO INDICATE PREVAILING CLOUD HEIGHTS OF THE LOW CLOUDS MOSTLY IN THE VFR RANGE WITH SOME MVFR IN THE HIGHER TERRAIN NEAR THE VA BORDER. A BRIEF PERIOD OF A DROP TO MVFR CLOUD OCCUR AT EITHER OF THE THREE TAF SITES...BUT CURRENT THINKING IS THAT THIS WOULD BE SHORT LIVED AND CONFIDENCE IN THIS WAS TOO LOW FOR ANY TEMPOS AT THIS POINT. AT THIS POINT VFR IS EXPECTED DURING THE FIRST 6 TO 12 HRS OF THE PERIOD... THUS VFR SHOULD PREVAIL THE ENTIRE PERIOD AT THE TAF SITES. && .JKL WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY FROM 2 AM TO 10 AM EDT TUESDAY FOR KYZ044-050>052- 058>060-068-069-080-086>088-104-106>120. && $$ UPDATE...JP SHORT TERM...ABE LONG TERM....SHALLENBERGER AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
157 AM EDT MON MAR 26 2012 .UPDATE... ISSUED AT 150 AM EDT MON MAR 26 2012 LOW CLOUDS CONTINUE TO GENERALLY ADVECT FROM NNW TO SSE ACROSS THE CWA AT THIS TIME WITH MORE OF A SOLID BAND ACROSS THE SOUTHERN CWA THAT AT THIS POINT STILL SEEMS TO BE ADVECTION OUT AND THEN SOME MORE PATCHY LOW CLOUDS FURTHER NORTH ACROSS SOUTHERN OH AND PARTS OF CENTRAL AND NORTHEASTERN KY THAT GENERALLY ALSO APPEAR TO BE ADVECTING ACROSS RATHER THAN DEVELOPING FURTHER. A RATHER SUBTLE VORT/ SHORTWAVE WILL BE ROTATING ACROSS THE REGION FOR THE REMAINDER OF THE NIGHT AND THIS WILL PROBABLY AT LEAST TEMPORARILY SLOW DOWN THE ADVECTION OF THE MORE SOLID BAND IN THE SOUTH OUT AND COULD LEAD TO SOME FURTHER DEVELOPMENT OF CURRENTLY MORE SCATTERED LOW CLOUDS WORKING IN FROM THE NNW. THE GRIDS WERE UPDATED TO GENERALLY REFLECT THIS THINKING FOR SKY COVER AND TO ACCOUNT FOR THE RECENT OBS TRENDS TO TEMPS...DEWPOINTS AND WINDS. UPDATE ISSUED AT 1050 PM EDT SUN MAR 25 2012 CLOUD DECK AROUND 4K AGL FEET CURRENTLY ADVECTING SOUTH ACROSS THE FORECAST AREA PER LATEST SATELLITE IMAGERY. BACK EDGE OF THIS CLOUD DECK WILL CLEAR THE NORTHERN PART OF FORECAST AREA BY MIDNIGHT. HOWEVER...WITH CONTINUED NORTHERLY FLOW AND LOW LEVEL MOISTURE AVAILABLE EXPECT UPSLOPE FLOW TO KEEP CLOUDS IN THE SOUTHEAST PART OF FORECAST AREA FOR MOST OF THE NIGHT. THIS IDEA IS SUPPORTED BY LATEST RUC GUIDANCE. HAVE UPDATED NDFD AND ASSOCIATED PRODUCTS PER LATEST SATELLITE AND OBSERVATIONAL DATA. UPDATE ISSUED AT 759 PM EDT SUN MAR 25 2012 THE LAST ISOLATED SHOWERS DISSIPATED OR MOVED OUT OF THE AREA AROUND 730 PM EDT...SO HAVE REMOVED ALL PRECIPITATION FROM THE NDFD AND ASSOCIATED PRODUCTS FOR THE OVERNIGHT PERIOD. ALSO MADE SOME MINOR UPDATES BASED ON LATEST OBSERVATIONAL TRENDS. THE MAIN FORECAST ISSUE IS HOW MUCH CLOUDINESS THERE WILL BE OVERNIGHT. THERE IS CONSIDERABLE LOW CLOUDINESS UPSTREAM OF THE AREA...AND LATEST NAM AND RUC GUIDANCE SHOW CONSIDERABLE LOW LEVEL MOISTURE...MAINLY BELOW 850 MB TO BE OVER THE AREA TONIGHT. WITH NORTHERLY FLOW EXPECT CLOUDINESS TO INCREASE IN COVERAGE DURING THE NIGHT...WITH MOSTLY CLOUDY SKIES BEING THE RESULT. UPDATE ISSUED AT 423 PM EDT SUN MAR 25 2012 BASED ON RADAR TRENDS ISOLATED TO SCATTERED SHOWERS WILL AFFECT FAR EASTERN KENTUCKY THROUGH 23Z. THIS IS CURRENTLY WELL DEPICTED IN NDFD. ONLY SOME MINOR NDFD UPDATES WERE MADE BASED ON LATEST SATELLITE AND SURFACE OBSERVATIONAL TRENDS. && .SHORT TERM...(LATE THIS AFTERNOON THROUGH TUESDAY) ISSUED AT 310 PM EDT SUN MAR 25 2012 UPPER LEVEL LOW WILL CONTINUE TO PULL AWAY FROM THE AREA TONIGHT GIVING WAY TO UPPER LEVEL RIDGING THROUGH THE REMAINDER OF THE PERIOD. THE UPPER LOW WILL REMAIN CLOSE ENOUGH TO KEEP A MENTION OF A FEW SHOWERS IN THE FORECAST FOR MOST AREAS LATE THIS AFTERNOON... WITH THE CHANCE OF SHOWERS LINGERING ACROSS THE TIP OF FAR EAST KENTUCKY THIS EVENING. IT APPEARS THAT INSTABILITY WILL NOT BE SUFFICIENT TO PRODUCE A TSTORM THIS FAR WEST SO REMOVED THAT MENTION FOR THIS AFTERNOON AND EVENING. A COLD FRONT WILL THEN DROP IN FROM THE NORTH LATE TONIGHT KEEPING A LIGHT BREEZE BLOWING FOR MOST LOCATIONS. MOISTURE POOLING ALONG THIS BOUNDARY IN CONJUNCTION WITH THE LIGHT NORTHEAST LOW LEVEL FLOW WILL LIKELY RESULT IN QUITE A BIT OF STRATUS DEVELOPING OVERNIGHT WITH MAYBE EVEN A LITTLE DRIZZLE. ANY CLOUD COVER SHOULD DISSOLVE BY MIDDAY MONDAY AS HIGH PRESSURE BEGINS TO BUILD DOWN INTO THE OHIO VALLEY ACCOMPANIED BY A MUCH DRIER AIRMASS. IN FACT...DEWPOINTS ARE PROGGED TO DROP INTO THE 20S OVER NORTHEAST KENTUCKY LATE MONDAY NIGHT AND THERE IS A CONCERN THAT TEMPERATURES WILL RESPOND TO THIS DRY AIR AND DROP LOW ENOUGH TO THREATEN A FROST OR FREEZE FOR SOME AREAS. CONFIDENCE IS NOT HIGH ENOUGH TO HOIST ANY HEADLINES AT THIS TIME THOUGH AS MODELS INDICATE THE POTENTIAL FOR SOME HIGH LEVEL CLOUDINESS TO MOVE IN OVERNIGHT AND POINT TO THERE BEING JUST ENOUGH WIND TO KEEP ANY FROST FORMATION ISOLATED AND CONFINED TO THE DEEPEST VALLEYS BASICALLY NORTH AND EAST OF JKL. HIGH PRESSURE WILL REMAIN IN CONTROL ON TUESDAY BUT HIGH LEVEL CLOUDS WILL BE ON THE INCREASE IN ADVANCE OF OUR NEXT WEATHER MAKER. TEMPS ARE TRICKY...VARYING 10 TO 15 DEGREES BETWEEN THE GFS AND NAM MOS AT ANY GIVEN POINT. TEND TO AGREE MORE WITH THE GFS NUMBERS WITH THE UPPER LEVEL RIDGE BUILDING IN AND WILL FORECAST HIGHS APPROACHING OR EXCEEDING 70 FOR MOST LOCATIONS. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 310 PM EDT SUN MAR 25 2012 MODELS CONTINUE TO DISPLAY GOOD CONTINUITY THRU MOST OF THE WORK WEEK BUT BEGIN TO DIVERGE RATHER SHARPLY ON FRIDAY WITH THE LONG WAVE PATTERN. HAVE GENERALLY FOLLOWED A BLEND OF THE MEDIUM RANGE OPERATIONAL/ENSEMBLE GUIDANCE THRU THE FIRST HALF OF THE PERIOD BEFORE GIVING MORE CREDENCE TO THE LESS EXTREME SOLUTION OF THE GFS OVER THE WEEKEND...THOUGH CONFIDENCE WITH THE DETAILS TOWARDS THE TAIL END OF THE PERIOD REMAINS RATHER LOW. VORTEX CURRENTLY MAKING LANDFALL ALONG THE CA/OR COAST IS EXPECTED TO SEND A DECENT SHORT WAVE OVER THE ROCKIES AND ACROSS THE NRN PLAINS BEFORE REACHING THE UPPER MIDWEST BY TUESDAY NIGHT TO START THE PERIOD. AS THIS WAVE CONTINUES TO PUSH EAST ALONG THE CANADIAN BORDER...THE COLD FRONT ASSOCIATED WITH THE SFC REFLECTION LOOKS TO SWEEP ACROSS THE OHIO RIVER AND INTO ERN KY ON WEDNESDAY...WITH ENOUGH INSTABILITY STILL ADVERTISED IN FCST SOUNDINGS AROUND THE AREA TO WARRANT CHANCES OF THUNDER FOR WEDNESDAY. GIVEN THE PROGRESSIVE NATURE OF THE PATTERN...WOULD PREFER TO GO MOSTLY QUIET BY WEDNESDAY NIGHT BUT WILL SETTLE FOR A GENTLE NUDGE IN THAT DIRECTION FOR THE MOMENT. CANADIAN HIGH PRESSURE BUILDS DOWN ACROSS THE GREAT LAKES AND INTO THE OHIO VALLEY ON THURSDAY...BRINGING ANOTHER BOUT OF BENIGN WEATHER THROUGH FRIDAY...AT WHICH POINT THE MODELS BEGIN PARTING WAYS WITH THEIR DEPICTION OF THE UPPER LEVEL FEATURES. REGARDLESS OF THEIR RESPECTIVE DIFFERENCES...ANY OF THE RECENT OFFINGS FROM THE GUIDANCE WOULD POINT TOWARDS AN UNSETTLED PATTERN PERSISTING THROUGH THE WEEKEND WITH PERIODS OF RAIN POSSIBLE AND A FEW THUNDERSTORMS NOT ENTIRELY OUT OF THE QUESTION. AT THIS TIME...WILL KEEP POPS IN THE LOW END CHANCE RANGE UNTIL A BETTER CONSENSUS CAN BE OBTAINED. TEMPERATURES OVER THE COURSE OF THE PERIOD LOOK TO CONTINUE FOLLOWING THE ABOVE NORMAL TREND...WITH TEMPS EARLY IN THE PERIOD STILL RUNNING WELL ABOVE NORMAL BEFORE TRENDING TOWARDS CLIMO BY THE BEGINNING OF NEXT WEEK. ONE NOTE OF CONCERN IS FOR THURSDAY NIGHT INTO FRIDAY MORNING WHERE AGAIN...MODELS POINT TOWARDS RELATIVELY CLEAR SKIES AND LIGHT WINDS WITH DEWPTS IN THE UPPER 20S AND LOWER 30S THROUGHOUT OUR NERN VALLEYS. HAVE STRAYED TOWARDS THE COOLER SIDE OF THE MOS LOWS FOR NOW AND...GIVEN THE EVOLVING UNCERTAINTY JUST BEYOND THIS WINDOW...WILL CONTINUE TO KEEP A CLOSE EYE ON THESE NUMBERS OVER THE NEXT FEW DAYS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 150 AM EDT MON MAR 26 2012 MAIN ISSUE OF CONCERN FOR THIS TAF ISSUANCE AND THE FIRST 6 TO 12 HOURS OF THE PERIOD CONTINUES TO BE THE MOVEMENT OF LOW CLOUDS ACROSS THE AREA AND THE POTENTIAL FOR DEVELOPMENT OF LOW CLOUDS ACROSS THE FORECAST AREA DURING THE NEXT 6 TO 9 HRS AS A RATHER SUBTLE SHORTWAVE MOVES ACROSS THE AREA. THERE IS CONSIDERABLE LOW LEVEL CLOUDINESS ACROSS THE SOUTHERN CWA AT THIS TIME AND MORE ISOLATED TO SCATTERED PATCHES OF LOW CLOUDS ADVECTING IN FORM THE NORTH. AT THIS POINT ALL OF THE CLOUDS SEEM TO GENERALLY BE ADVECTING ACROSS THE AREA...BUT THE SHORTWAVE PASSING BY DURING THE NEXT 6 HRS OR SO MAY SLOW DOWN ADVECTION OF THE LOW CLOUDS OUT OF THE SOUTH AND POSSIBLE LEAD TO FURTHER DEVELOPMENT OF THE BANDS WORKING IN FROM THE NORTH AS THE MOVE ACROSS THE JKL CWA. AT THIS POINT...NAMBUFR SOUNDINGS SEEM TO INDICATE PREVAILING CLOUD HEIGHTS OF THE LOW CLOUDS MOSTLY IN THE VFR RANGE WITH SOME MVFR IN THE HIGHER TERRAIN NEAR THE VA BORDER. A BRIEF PERIOD OF A DROP TO MVFR CLOUD OCCUR AT EITHER OF THE THREE TAF SITES...BUT CURRENT THINKING IS THAT THIS WOULD BE SHORT LIVED AND CONFIDENCE IN THIS WAS TOO LOW FOR ANY TEMPOS AT THIS POINT. AT THIS POINT VFR IS EXPECTED DURING THE FIRST 6 TO 12 HRS OF THE PERIOD... THUS VFR SHOULD PREVAIL THE ENTIRE PERIOD AT THE TAF SITES. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...ABE LONG TERM....JP AVIATION...JP
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
401 AM EDT MON MAR 26 2012 .SYNOPSIS... CANADIAN HIGH PRESSURE WILL PROVIDE COLD, DRY, NORTHERLY WINDS ACROSS THE UPPER OHIO VALLEY TODAY. A HARD FREEZE WILL BE THE RESULT TONIGHT. A SOUTHEAST BOUND CANADIAN LOW WILL BRING MILD SHOWERY CONDITIONS WEDNESDAY, FOLLOWED BY DRY, SEASONABLE CONDITIONS INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LATEST HIRES MODELS CONTINUE TO SHOW AND AREA OF STRATOCU DEVELOPING AHEAD OF STRONG CAA THIS MORNING. CURRENT SAT PICS ARE SHOWING THIS AREA OF LOWER CLOUDS MOVING SOUTHWARD FROM THE GREAT LAKES, EXPECT A PERIOD OF CLOUDS TO BLANKET THE AREA THROUGH MID- MORNING. THESE CLOUDS WILL DISSIPATE QUICKLY AS A MUCH DRIER AIR MASS MOVES IN. BY LATE THIS MORNING AND EARLY AFTERNOON, EXPECT MAINLY SUNNY SKIES. COLD NORTHWEST WINDS EMANATING FROM EASTBOUND CANADIAN HIGH PRESSURE WILL LOWER 850 MB TEMPERATURES TO -7C. HENCE CONCUR WITH NAM AND GFS MOS THAT AFTERNOON TEMPERATURES WILL BE COLDER THAN CURRENT READINGS. NAM MODEL PROFILES SHOW NORTHWEST WINDS CAN GUST TO 25 MPH THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... MONDAY NIGHT WILL BE THE PERIOD OF COLDEST TEMPS WITH MODELS IN VERY GOOD AGREEMENT THAT OVERNIGHT LOWS WILL FALL INTO THE 20S. TEMPERATURES COLDER THAN 24F CONSTITUTE A HARD FREEZE WHICH GFS AND NAM MOS HAVE BEEN SHOWING. HENCE HAVE UPGRADED THE FREEZE WATCH TO A FREEZE WARNING. BECAUSE THIS IS SUCH A RARE CONGLOMERATION OF EVENTS, FELT IT NECESSARY TO ISSUE THE WARNING FOR ALL COUNTIES. AS WINDS ABATE TUESDAY, SUNSHINE SHOULD HELP TEMPERATURES REBOUND TO SEASONABLE LEVELS TUESDAY AFTERNOON. A WEAK COLD FRONTAL PASSAGE WEDNESDAY WILL BRING CLOUDINESS AND A CHANCE OF SHOWERS BUT WITH TEMPERATURES WELL ABOVE NORMAL. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... HIGH PRESSURE WILL FOLLOW THURSDAY WITH DRY WEATHER BUT COOLER TEMPERATURES. HIGH PRESSURE WILL DOMINATE INTO THE WEEKEND WITH DRY WEATHER AND SLOWLY MODERATING TEMPERATURES. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... RECENT SURFACE AND SATELLITE DATA SHOW MVFR STRATUS LINGERING NEAR THE MOUNTAINS WHILE A NEW BATCH HAS BEGUN TO DEVELOP BETWEEN KPIT-KCLE. HRRR AND NAM MODEL OUTPUT SHOW ADDITIONAL MVFR STRATUS DEVELOPING ACROSS MUCH OF THE UPPER OHIO VALLEY 09Z-14Z, AS THE SURFACE LAYER COOLS AND SATURATES DUE TO ADVECTIVE AND NOCTURNAL COOLING. NAM MODEL PROFILES AND GFS LAMP THEN SHOW THE LOW CLOUDS DISSIPATING TO PROVIDE CLEAR SKIES BY 16Z. SKIES WILL REMAIN CLEAR TONIGHT, AND EXPECT NO MORE THAN CIRRUS DAYTIME TUESDAY. SURFACE WINDS WILL BE FROM THE NORTHWEST INCREASING TODAY TO 13 KTS WITH GUSTS 20 TO 25 KTS BY AFTERNOON. WINDS WILL DECREASE TO 5-10 KTS TONIGHT. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...FREEZE WARNING FROM 10 PM THIS EVENING TO 10 AM EDT TUESDAY FOR MDZ001. OH...FREEZE WARNING FROM 10 PM THIS EVENING TO 10 AM EDT TUESDAY FOR OHZ039>041-048>050-057>059-068-069. PA...FREEZE WARNING FROM 10 PM THIS EVENING TO 10 AM EDT TUESDAY FOR PAZ007>009-013>016-020>023-029-031-073>076. WV...FREEZE WARNING FROM 10 PM THIS EVENING TO 10 AM EDT TUESDAY FOR WVZ001>004-012-021>023-041. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
224 AM EDT MON MAR 26 2012 .SYNOPSIS... CANADIAN HIGH PRESSURE WILL PROVIDE COLD DRY NORTHERLY WINDS ACROSS THE UPPER OHIO VALLEY TODAY, THAT WILL RESULT IN A HARD FREEZE TONIGHT. A SOUTHEASTBOUND CANADIAN LOW PRESSURE SYSTEM WILL BRING MILD SHOWERY CONDITIONS WEDNESDAY FOLLOWED BY DRY SEASONABLE CONDITIONS INTO THE WEEKEND. && .NEAR TERM /THROUGH TODAY/... PER RECENT SATELLITE DATA AND HRRR AND NAM MODEL OUTPUT THERE CAN BE A PERIOD OF LOW CLOUDS THIS MORNING. OTHERWISE SKIES WILL BE MAINLY CLEAR TODAY. COLD NORTHWEST WINDS EMANATING FROM EASTBOUND CANADIAN HIGH PRESSURE WILL LOWER 850 MB TEMPERATURES TO 7C. HENCE CONCUR WITH NAM AND GFS MOS THAT AFTERNOON TEMPERATURES WILL BE COLDER THAN CURRENT READINGS. NAM MODEL PROFILES SHOW NORTHWEST WINDS CAN GUST TO 25 MPH THIS AFTERNOON. && .SHORT TERM /TONIGHT THROUGH 6 PM TUESDAY/... MONDAY NIGHT WILL BE THE PERIOD OF COLDEST TEMPS WITH MODELS IN VERY GOOD AGREEMENT THAT OVERNIGHT LOWS WILL FALL INTO THE 20S. TEMPERATURES COLDER THAN 24F CONSTITUTE A HARD FREEZE WHICH GFS AND NAM MOS HAVE BEEN SHOWING. HENCE HAVE MAINTAINED A FREEZE WATCH. WILL LIKELY BE ISSUING A FREEZE WARNING WITH 4 AM ISSUANCE. AS WINDS ABATE TUESDAY, SUNSHINE SHOULD HELP TEMPERATURES REBOUND TO SEASONABLE LEVELS TUESDAY AFTERNOON. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... A WEAK COLD FRONTAL PASSAGE WEDNESDAY WILL BRING CLOUDINESS AND A CHANCE OF SHOWERS BUT WITH TEMPERATURES WELL ABOVE NORMAL. HIGH PRESSURE WILL FOLLOW THURSDAY WITH DRY WEATHER BUT COOLER TEMPERATURES. HIGH PRESSURE WILL DOMINATE INTO THE WEEKEND WITH DRY WEATHER AND SLOWLY MODERATING TEMPERATURES. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... RECENT SURFACE AND SATELLITE DATA SHOW MVFR STRATUS LINGERING NEAR THE MOUNTAINS WHILE A NEW BATCH HAS BEGUN TO DEVELOP BETWEEN KPIT-KCLE. HRRR AND NAM MODEL OUTPUT SHOW ADDITIONAL MVFR STRATUS DEVELOPING ACROSS MUCH OF THE UPPER OHIO VALLEY 09Z-14Z, AS THE SURFACE LAYER COOLS AND SATURATES DUE TO ADVECTIVE AND NOCTURNAL COOLING. NAM MODEL PROFILES AND GFS LAMP THEN SHOW THE LOW CLOUDS DISSIPATING TO PROVIDE CLEAR SKIES BY 16Z. SKIES WILL REMAIN CLEAR TONIGHT, AND EXPECT NO MORE THAN CIRRUS DAYTIME TUESDAY. SURFACE WINDS WILL BE FROM THE NORTHWEST INCREASING TODAY TO 13 KTS WITH GUSTS 20 TO 25 KTS BY AFTERNOON. WINDS WILL DECREASE TO 5-10 KTS TONIGHT. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...FREEZE WATCH FROM THIS EVENING THROUGH TUESDAY MORNING FOR OHZ039>041-048>050-057>059-068-069. PA...FREEZE WATCH FROM THIS EVENING THROUGH TUESDAY MORNING FOR PAZ007>009-013>016-020>023-029-031-073-075. WV...FREEZE WATCH FROM THIS EVENING THROUGH TUESDAY MORNING FOR WVZ001>004-012-021-022. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1218 AM EDT MON MAR 26 2012 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 454 PM EDT SUN MAR 25 2012 LOW CLOUDS HAVE BEEN VERY PERSISTENT TODAY...AS THE H875 INVERSION HAS BEEN DIFFICULT TO ERRODE. AWAY FROM THE COOLING OFF LK SUPERIOR...THE CLOUDS HAVE MIXED OUT...BUT STILL HAVE A DECENT SWATH OF CLOUDS OVER SRN ONTARIO NEAR THUNDER BAY. MEANWHILE...1033MB SFC HIGH JUST NE OF LK WINNIPEG AND AN ASSOCIATED SFC RIDGE HAS BEEN WORKING INTO WRN LK SUPERIOR. FARTHER SW...DEVELOPING LOW OVER WYOMING AS LED TO SOME MID LVL WAA AND CLOUDS OVER SD AND SRN MN. THESE CLOUDS SHOULD STAY S OF THE AREA TONIGHT AS THE UPPER TROUGH DIGS OVER THE NEW ENGLAND STATES AND BRINGS DRIER MID LVL AIR INTO THE UPPER GREAT LKS. ISSUE FOR TONIGHT WILL BE THE CLOUDS NEAR/OVER LK SUPERIOR. WITH THE WAY THEY HAVE HUNG IN TODAY OVER THE KEWEENAW AND ERN LK...FEELING IS THAT THERE IS A GOOD CHANCE OF THEM HANGING AROUND FOR MUCH OF THE NIGHT. THERE SHOULD BE PLENTY OF LK INSTABILITY...AS H950-925 TEMPS ARE AROUND -9C AND LK TEMPS AROUND 3-4C. QUESTION WILL BE IF THE MOISTURE WILL REMAIN. THE MODELS HAVE BEEN HAVING A DIFFICULT TIME WITH THIS MOISTURE AND MOST HAVE THE MOISTURE DIMINISHING THIS EVENING WITH THE CONTINUED SUBSIDENCE AND DRY AIR WITH THE SFC RIDGE. BUT THE PERSISTENCE OF THE CLOUDS OVER SRN ONTARIO AND CNTRL/ERN LK SUPERIOR CREATES CONCERN ON IT COMPLETELY DIMINISHING. HAVE BUMPED UP CLOUDS TO PARTLY CLOUDY NEAR LK SUPERIOR FOR THE OVERNIGHT HOURS...AS TO SUBSIDENCE...ANTICYCLONIC FLOW...AND DECREASING MOISTURE UNDER THE HIGH PRESSURE RIDGE MAY BE ENOUGH TO DIMINISH THEM. THAT BEING SAID...COULD EASILY SEE THE MOISTURE BECOMING TRAPPED WITH LOSS OF HEATING AND REMAINING WITH THE LK INSTABILITY. DID TRY TO SHOW SOME MOVEMENT TO THE PARTLY CLOUDY SKY AS H925 WINDS VEER THROUGH THE NIGHT...WHICH WOULD FOCUS THE CLOUDS OVER THE N THEN NE FAVORED LOCATIONS. IN ADDITION...13-16Z RUC RUNS TRY TO DEVELOP LK ENHANCED PCPN OVER CNTRL/ERN LK SUPERIOR THIS EVENING AND THEN DROP IT INTO UPPER MI. THE ONLY OTHER HIRES MODEL TO MENTION IT WAS THE REGIONAL GEM. WITH A FEW SHOWERS DEVELOPING TODAY DEVELOPMENT WOULDN/T BE SURPRISING...BUT WITH CONCERNS ON AMNT OF MOISTURE PRESENT DECIDED TO LEAVE OUT. LOWS TONIGHT HAVE HIGH BUST POTENTIAL DUE TO SEVERAL INFLUENCES. NEAR LK SUPERIOR...THE CLOUDS/WIND WILL BE THE MAIN FACTOR. THE COMBINATION OF THE TWO CREATES UNCERTAINTY AND HAVE STUCK WITH A MIDDLE GROUND IN THE UPPER 20S. FARTHER INLAND...TEMPS COULD REALLY TANK ONCE THE WINDS DIMINISH THIS EVENING AND IF SKIES REMAIN MOSTLY CLEAR. PWATS AROUND 0.25IN OR ABOUT 40 PERCENT OF NORMAL AND LIGHT WINDS CREATES A GOOD RADIATIONAL COOLING NIGHT AND EXPECT TEMPS TO FALL NEAR 20. IF THE CLOUDS REMAIN AWAY...COULD SEE VALUES EVEN COLDER INTO THE TEENS OVER THE INTERIOR WEST COLD SPOTS. MONDAY...HIGH PRESSURE CENTERED JUST SW OF JAMES BAY WILL KEEP THE SFC RIDGE OVER THE AREA...WHILE AN UPPER RIDGE WILL START TO BUILD OVER THE NRN PLAINS. RIDGE WILL GRADUALLY SHIFT E THROUGH THE DAY...AS SFC LOW DEVELOPS OVER ERN MONTANA/WYOMING. OTHER THAN THE PREVIOUSLY MENTIONED POTENTIAL FOR LINGERING LK CLOUDS IN THE MORNING...DRY AIR AND SUBSIDENCE FROM THE HIGH SHOULD LEAD TO A MOSTLY SUNNY DAY. MID CLOUDS DEVELOPING UNDER H700 WAA MON AFTN OVER MN AND NW WI...AND WILL APPROACH THE FAR WRN CWA LATE IN THE AFTN. COOL NRLY FLOW OFF LK SUPERIOR WILL KEEP MIXING DOWN NEAR THE LK SHORE AND KEEP HIGHS IN THE 30S. FARTHER INLAND AWAY FROM THE LK INFLUENCE...MIXING TOWARDS H850 TEMPS OF -4C WEST AND -9C EAST WILL PRODUCE HIGHS IN THE LOW-MID 40S...ESPECIALLY ALONG THE WI BORDER. AS FOR DEWPOINTS...MODEL MIXED LAYER DEWPOINT VALUES ARE IN THE LOW SINGLE DIGITS ABOVE ZERO OVER THE E HALF OF THE LAND CWA. THIS HAS BEEN CONSISTENT OVER THE LAST SEVERAL RUNS...SO HAVE ADJUSTED GOING VALUES DOWN A TOUCH AWAY FROM THE MOISTENING AFFECTS OF LK SUPERIOR. THIS LEADS TO RH VALUES FALLING INTO THE UPPER 20S...WITH A FEW MID-LOWER 20S OVER THE ERN CWA. WITH WINDS MAINLY 10KTS OR LESS AND ALONG WITH THE COOLER TEMPS...EXPECT FIRE WX CONCERNS TO BE LIMITED. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 454 PM EDT SUN MAR 25 2012 MONDAY NIGHT AND TUE...THE GFS...ECMWF AND NAM HAVE BEEN CONSISTENT AND WERE IN REASONABLY GOOD AGREEMENT WITH THE SHORTWAVE LIFTING FROM THE PLAINS TO THE NRN GREAT LAKES. STRONG WAA AND 295K- 305K ISENTROPIC LIFT (NOSE OF 850-800MB WINDS 50-55KT) WILL SUPPORT A BAND OF PCPN THROUGH THE CWA LATE MONDAY NIGHT INTO TUESDAY MORNING. THE VERY STRONG WAA IN THE 850-700 MB LAYER PUSHING WARM NOSE TEMPS TO AROUND 5C SHOULD LEAD TO MOSTLY LIQUID PCPN. WITH INCREASING CLOUDS AND WAA OVER THE FAR WEST EXPECT THAT SFC TEMPS SHOULD REBOUND ENOUGH BY THE ONSET OF PCPN TO KEEP PCPN AS RAIN. HOWEVER...OVER INTERIOR WEST AND CENTRAL UPPER MICHIGAN TEMPS INTO THE UPPER 20S TO AROUND 30 MAY LINGER AS THE PCPN MOVES IN. EVAPORATIVE COOLING AT THE ONSET OF PCPN WILL ALSO DELAY LOW LEVEL WARMING. WITH RELATIVELY WARM GROUND TEMPERATURES AFTER THE LONG WARM SPELL...THERE IS ADDITIONAL UNCERTAINTY ON HOW MUCH ICE IF ANY WOULD ACCUMULATE. SO...MENTIONED BOTH RA/FZRA FOR MOST OF THE THE CWA AND HIGHLIGHTED THE HAZARD IN A PORTION OF THE SPS. INSTABILITY FOR TSRA LOOKS MARGINAL...BUT SOME ELEVATED CAPE INTO EDING INTO THE CWA SUPPORTS AT LEAST CONTINUED MENTION OF SLIGHT CHANCE FOR TSRA. TUE NIGHT INTO WED...AS THE DRY SLOT SPREADS ACROSS THE ARA LATE TUE INTO TUE EVENING...PCPN SHOULD DIMINISH TO AREAS OF DRIZZLE OR ISOLATED SHOWERS DURING THE AFTERNOON AND EVENING. AS THE MID LEVEL LOW MOVES OFF TO THE NORTHEAST OF LAKE SUPERIOR AND A TRAILING SHORTWAVE MOVES THROUGH UPPER MI SOME ADDITIONAL WRAP-AROUND LIGHT SHOWERS MAY BE POSSIBLE WED MORNNG. BY THE TIME THE COLDER AIR ARRIVES WED AFTERNOON...DRIER AIR WILL ALSO SPREAD INTO THE REGION. SO...ONLY LOW END POPS FOR SOME LIGHT LAKE ENHANCED PCPN. THU-SUN...HIGH PRES SHOULD BUILD INTO THE AREA THU WITH COOL DRY AND MOSTLY SUNNY CONDITIONS. MODELS CONTINUE TO SUGGEST POTENTIAL FOR ANOTHER SHRTWV AND PCPN CHANCES MOVING INTO THE AREA THU NIGHT INTO FRIDAY EVEN THOUGH CONFIDECNE IN DETAILS IS LOW. A BLOCKING RIDGE TO THE NORTH WITH A SFC HUDSON BAY HIGH EXTENDEDING INTO THE AREA WILL LIMIT PCPN CHANCES TO LOWER END POPS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1212 AM EDT MON MAR 26 2012 MAIN FCST ISSUE OVERNIGHT IS STRATOCU OFF THE LAKE. WITH LOW-LEVEL WINDS VEERING FROM NORTHERLY TO NORTHEASTERLY...KSAW WILL BE FAVORED FOR BKN MVFR CIGS ABOVE 2000FT...ESPECIALLY WITH STRATOCU E AND NE OF LAKE SUPERIOR PER SATELLITE IMAGERY. THE CLOUDS WILL SCATTER OUT AT TIMES. EXPECT CLOUDS AT KSAW TO CLEAR OUT MID TO LATE MORNING WITH VFR CONDITIONS CONTINUING THRU THE END OF THIS FCST PERIOD. AT KCMX/KIWD...VFR CONDITIONS WILL PREVAIL. NOT EXPECTING ANYTHING MORE THAN SCT STRATOCU AT KCMX OVERNIGHT WITH UNFAVORABLE WIND DOWN THE SPINE OF THE KEWEENAW...AND CLEAR SKIES SHOULD DOMINATE AT KIWD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 454 PM EDT SUN MAR 25 2012 HIGH PRESSURE RIDGE MOVING INTO LAKE SUPERIOR TONIGHT WILL GRADUALLY DIMINISH THE PRESSURE GRADIENT OVER LAKE SUPERIOR AND LEAD TO A GRADUAL DIMINISHING TREND IN THE VEERING WINDS TONIGHT INTO MONDAY MORNING. AS THE LOW SHIFTS E ON MONDAY...A LOW PRESSURE SYSTEM DEVELOPING IN THE NRN PLAINS WILL SHIFT EAST AND ACROSS THE UPPER GREAT LAKES TUESDAY NIGHT AND WEDNESDAY. THIS COULD PRODUCE A SOUTHERLY GALE FORCE GUSTS TO 35KTS ON TUESDAY OVER EASTERN LAKE SUPERIOR. HIGH PRESSURE RIDGE WILL THEN BUILD OVER THE UPPER GREAT LAKES WED NIGHT AND THURSDAY...KEEPING WINDS BELOW 25KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY AFTERNOON FOR LSZ266. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...JLB AVIATION...ROLFSON MARINE...SRF
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
342 AM CDT MON MAR 26 2012 .DISCUSSION... MAIN CONCERN OVER THE NEXT 30 HOURS IS THE POTENT UPPER LEVEL TROUGH CURRENTLY OVER THE GREAT BASIN. THIS IS PROGGED TO TAKE A TRACK NEWD TODAY AND MOVE THROUGH THE NORTHERN PLAINS TONIGHT AND TUE. AHEAD OF THE STRONG SYSTEM LOW LEVEL WAA IS CURRENTLY TAKING PLACE ACROSS THE REGION. MODELS SEEM TO HAVE A HIGH BIAS WITH THE MOISTURE ATTM...AND THUS A LITTLE BULLISH ON THE CONVECTIVE POTENTIAL FOR THE REST OF THE NIGHT. LATEST RUC ANALYSIS DOES INDC AROUND 500-1000 J/KG OF MUCAPE OVER THE WRN CWA...BUT POINT FORECAST SOUNDINGS INDC THIS MOISTURE IS RATHER SHALLOW AROUND 850 MB AND THERE IS A GOOD DEAL OF CIN HOLDING BACK THE CONVECTION. WE FEEL THIS TREND WILL CONT TONIGHT...BUT WILL MAINTAIN A SLIGHT CHANCE POPS B/W 12-15Z OVER THE CNTRL AND SERN CWA FOR ANYTHING ISO THAT MAY DEVELOP. OTHERWISE ANOTHER WINDY AND WARM DAY IS IN STORE FOR THE FA. WINDS AT 925 (850) MB INCREASE TO 40 (55) KT BY THIS AFTERNOON AND WITH THE INCREASING PRESSURE GRADIENT...SOME OF THIS SHOULD MAKE IT TO NEAR THE SURFACE. HIGH CLOUDS WILL LIKELY LIMIT MIXING THOUGH...AND WE WOULD FEEL BETTER WITH A DUE SOUTH OR SW WIND...SO A WIND ADVRY IS NO SLAM DUNK...BUT WITH THE PRESSURE GRADIENT AND MIXING TO 925 MB WE WILL LIKELY SEE A FEW SITES MEET CRITERIA THIS AFTN INTO THE EVNG HOURS. THUS WE HAVE ISSUED A WIND ADVISORY. THE DRY LINE STILL LOOKS TO SET UP OVER THE WRN HI PLAINS TODAY AS THE UPPER LEVEL SYSTEM MOVES TOWARD THE REGION. SOME POSITIVE CAPE IS INDICATED NEAR THE DRY LINE...BUT CIN IS SIGNIFICANT AND WITH MUCH OF THE FORCING GOING INTO SODAK...CONVECTIVE POTENTIAL FOR THE NEB AREA LOOKS PRETTY LOW...AND ESPECIALLY ANYTHING THAT WOULD WORK INTO OUR FA. THUS HAVE REDUCED POPS TO SCHC FOR THIS EVNG IN THE NW. A LITTLE BETTER CHC OF SHOWERS/STORMS MAY ACTUALLY COME AFTER MIDNIGHT IN THE ERN FA AS BETTER MOISTURE INTERACTS WITH THE ADVANCING PAC CDFNT AS IT MOVES THROUGH THE AREA. WILL CONT SOME CHC POPS IN THE E AFTER MIDNIGHT FOR THIS. THE SYSTEM SHOULD BE CLEAR OF THE FA BY TUES MRNG WITH ANOTHER WARM AND DRY DAY EXPECTED FOR TUE/WED. THE SURFACE FNT STILL LOOKS TO HANG UP OVER MO/KS ON TUE/WED AND THIS WILL START TO RETREAT NWD WED NIGHT AND INTO THE DAY ON THU (ALTHOUGH I HAVE MY DOUBTS THAT IT WILL ACTUALLY MAKE IT INTO NEB). AS THE LOW LEVEL WAA INCREASES AHEAD OF A SHRTWV PROGGED FOR THU NIGHT SOME MOISTURE WILL LIKELY WORK AROUND THE FNT AND INTO CNTRL NEB BY LATE THU WHICH SHOULD ALLOW FOR A CHANCE OF SHOWERS/STORMS LATE THU...THU NIGHT AND INTO FRI. SIGNIFICANT DIFFERENCES THEN DEVELOP BETWEEN THE GFS AND EC FOR NEXT WEEKEND AND NO CHANGES WERE MADE PAST FRI. BOUSTEAD && FIRE WEATHER... IN THE POST FRONT AIRMASS ON TUES THE AIR MASS IS EXPECTED TO DRY OUT SIGNIFICANTLY. DEEP MIXING TO AROUND 850 MB OR HIGHER WILL LEAD TO DEWPOINTS FALLING THROUGH A GOOD PART OF THE DAY IN THE CNTRL AND WRN CWA. DESPITE THE FRONT MOVING THROUGH...TEMPERATURES WITH THE MIXING ON TUES WILL LIKELY CLIMB BACK INTO THE MID AND EVEN SOME UPPER 70S. THIS WILL CREATE SEVERAL HOURS OF RH BELOW 20 PERCENT DURING THE AFTN ON TUES. WITH STRONGLY UNIDIRECTIONAL FLOW AND A DECENT PRESSURE GRADIENT ON THE SOUTH SIDE OF THE SURFACE LOW OVER SD...SFC WINDS SHOULD BE SUSTAINED ABOVE 15 KT WITH GUSTS WELL OVER 25 KT. THIS ALL SHOULD COMBINED FOR A DANGEROUS FIRE WX DAY. ALTHOUGH WE ARE STARTING TO GREEN UP NICELY AROUND THE ARE AND THUS HAVE ISSUED A FIRE WEATHER WATCH FOR TUES FOR A LARGE PART OF THE AREA. MAYES && .AVIATION... 06Z TAFS FOR KOFK...KOMA AND KLNK. WARM ADVECTION REST OF TONIGHT WILL BRING OCCASIONAL VFR CIGS...GENERALLY AT OR ABOVE 5K AGL FT...TO TAF SITES. ALTHOUGH IT APPEARS MVFR CIGS/VSBYS SHOULD NOT OCCUR. THERE IS AN SLIGHT CHANCE A SHOWER/TSTM COULD DEVELOP IN WARM ADVECTION ZONE FM CNTRL INTO NCNTRL NEBRASKA WHICH COULD DRIFT ACROSS ERN NEBR LATE TONIGHT/MON MORNING. HOWEVER...COVERAGE/CHANCE IS TOO SMALL TO INCLUDE IN TAF FORECAST. SSE SURFACE WINDS WILL DRAMATICALLY INCREASE BY MONDAY AFTERNOON WITH SUSTAINED WINDS LIKELY AT LEAST IN 20-25KT RANGE. A STRONG UPPER SYSTEM LIFTING NE ACROSS THE DAKOTAS LATE MONDAY WILL SEND A COLD FRONT TOWARD CENTRAL NEBRASKA WITH AN ISOLD SHOWER/TSTM APPROACHING NERN NEBRASKA TOWARD 27/06Z. CHERMOK && .OAX WATCHES/WARNINGS/ADVISORIES... NE...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR NEZ011-012-015>018-030>034-042>045-050>053- 065>067-078-088-089. WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING FOR NEZ015-033-043-044-050-051-065-078. WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 10 PM CDT THIS EVENING FOR NEZ011-012-016>018-030>032-042. IA...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR IAZ043-055. && $$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1155 PM CDT SUN MAR 25 2012 .AVIATION...06Z TAF. MID TO HIGH LEVEL CLOUDS WILL SETTLE ACROSS THE TERMINAL OVERNIGHT. MOISTURE AXIS IS WEST OF KGRI WHERE PATCHY FOG IS POSSIBLE...OTHERWISE AN INCREASING LLVL JET OVERNIGHT MAY LEAD TO SOME HIT OR MISS CONVECTION WITH KGRI ON THE PERIPHERY OF THE POTENTIAL. SOUTHERLY WINDS WILL BE ON THE INCREASE MONDAY WITH WIND SPEEDS IN THE AFTN AVERAGING 25 TO 30KTS WITH GUSTS OVER 40KTS. && .PREV DISCUSSION... /ISSUED 1005 PM CDT SUN MAR 25 2012/ UPDATE...MOISTURE AXIS IS ALIGNING ACROSS OUR WESTERN CWA ATTM AND HRRR MODEL SUGGESTS POTENTIAL FOR SOME REDUCED VSBYS IN FOG ALONG MOISTURE AXIS AND HAVE ADDED IN SOME PATCHY FOG TOWARD MORNING. ALSO...INCREASING LLVL JET OVER MOISTURE AXIS AND DECENT AREA OF THETA E ADVECTION ALIGNS ACROSS OUR EASTERN CWA OVERNIGHT. CANNOT COMPLETELY RULE OUT A STORM OR TWO IN THIS AREA AND INCLUDED SOME LOW POPS FOR TONIGHT. PREV DISCUSSION... /ISSUED 448 PM CDT SUN MAR 25 2012/ SHORT TERM...TONIGHT AND TOMORROW. PRIMARY FORECAST CONCERNS LIE WITH PRECIPITATION CHANCES AND WINDS. UPPER AIR PROFILER AND SATELLITE DATA SHOW THE CENTRAL PLAINS REMAINING UNDER THE INFLUENCE OF A RIDGE AXIS...SANDWICHED BETWEEN LOW PRESSURE SYSTEMS LOCATED OVER THE CAROLINAS AND JUST OFF THE SOCAL COAST. LOW LEVEL STRATUS WHICH WAS PUSHING SOUTH THIS MORNING MADE IT IN TO JUST ABOUT I-80...BEFORE THE LOW LEVEL WINDS STARTED TRANSITIONING FROM THE NORTH TO MORE TO THE EAST. TOOK A LITTLE BIT...BUT THE SFC RIDGE AXIS FINALLY SHIFTED OFF TO THE EAST OF THE CWA...AND WITH LOW PRESSURE OVER THE ROCKIES...WINDS ACROSS THE ENTIRE CWA EVENTUALLY SWITCHED OVER TO THE S/SE. BETWEEN THIS MORNINGS CLOUD COVER NOT ERODING UNTIL LATE MORNING AND ANOTHER BATCH OF LOW/MID LEVEL CLOUDS AFFECTING THE NWRN CORNER OF THE CWA...TEMPS THIS AFTERNOON HAVE ONLY REACHED INTO THE MID 60S TO LOW 70S...VS THE MID/UPPER 70S ELSEWHERE ACROSS THE CWA. LOOKING TO THIS EVENING AND OVERNIGHT...KEPT THE FORECAST DRY...BUT WILL STATE THAT CONFIDENCE IS NOT HIGH...ESP IN THE NORTHEAST/EASTERN QUARTER OR SO OF THE CWA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE DEVELOPMENT OF A 40-50KT SWRLY LLJ TONIGHT...WHICH NOSES INTO...AND EVENTUALLY THROUGH THE CWA BY 12Z MONDAY. ACCOMPANYING THE NOSE OF THE LLJ IS A SURGE OF INCREASED WARM AIR/THETAE ADVECTION...MAINLY AFFECTING THE NERN HALF OF THE CWA BETWEEN 06-12Z. REALLY DEBATED THROWING SOME SMALL POPS IN...BUT ANOTHER THING THAT THE MODELS ARE IN GOOD AGREEMENT ON IS THE PRESENCE OF CAPPING...SHOWING 700MB TEMPS RANGING ANYWHERE FROM 5-9 DEG C DEPENDING ON THE MODEL. THE CAPPING IS A BIT WEAKER ALONG THAT NE/ERN FRINGE OF THE CWA...AND WHILE THE GFS DEVELOPS PRECIP THERE ISNT MUCH SUPPORT FROM OTHER MODELS WITH THERE BEING ENOUGH FORCING TO BREAK THROUGH THAT CAP. WITH CONTINUED S/SERN FLOW OVERNIGHT /WITH SPEEDS HIGHER THAN LAST FEW NIGHTS/...EXPECTING LOW TEMPS TO BE WARMER...AND FORECAST LOWS SIT IN THE LOWER/MID 50S. AS WE GET INTO TOMORROW...THE MAIN FOCUS TURNS TO WINDS...THOUGH PRECIPITATION CHANCES REMAIN FOR LATE AFTERNOON. THE UPPER LEVEL PATTERN SHOWS THE MAIN RIDGE AXIS SLIDING OFF TO THE EAST AS A DISTURBANCE MAKES ITS WAY TROUGH THE ROCKIES...LEAVING THE CWA WITH SWRLY FLOW. AS THIS DISTURBANCE MOVES CLOSER...EXPECTING TO SEE DEEPENING SFC LOW PRESSURE OVER THE NORTHERN ROCKIES WITH A TROUGH AXIS EXTENDING SOUTH THROUGH THE HIGH PLAINS. THIS WILL RESULT IN A TIGHTENING PRESSURE GRADIENT ACROSS THE CENTRAL PLAINS...AND INCREASING SRLY WINDS THROUGH THE DAY. WHILE MIXING POTENTIAL LOOKS TO ONLY REACH UPWARDS OF 850MB...THERE ARE ALSO INCREASED WINDS TO TAP INTO. DECIDED TO GO WITH A WIND ADV ACROSS THE CENTRAL AND WRN PORTIONS OF THE CWA...ALONG AND WEST OF HWY 281 DURING THE AFTERNOON HOURS. THE ERN FRINGE IS MORE ON THE MARGINAL SIDE...BUT WAS COMFORTABLE INCLUDING IT. EXPECTING TO SEE A BUMP UP IN TEMP...WITH HIGHS IN THE LOWER/MID 80S. AT THIS POINT COULD CREEP CLOSE TO RECORD HIGHS /MAINLY IN HASTINGS AND KEARNEY/...BUT SHOULD REMAIN BELOW. RECORDS ARE 86 AT BOTH HASTINGS AND KEARNEY IN 1989...AND 90 IN GRAND ISLAND IN 1907. THE POTENTIAL FOR THUNDERSTORMS BEGINS TO INCREASE LATE IN THE AFTERNOON...MAINLY ACROSS THE FAR WRN FRINGE OF THE CWA...AND DID KEEP THE LOW POPS IN. WHILE WE DO HAVE INCREASING INSTABILITY/LAPSE RATES AND THE DISTURBANCE IS SHIFTING CLOSER...MODELS REMAIN IN GOOD AGREEMENT KEEPING THINGS PRETTY CAPPED THROUGH THE AFTERNOON...SO WAS NOT GOING TO INCREASE POPS. LONG TERM...MONDAY EVENING THROUGH NEXT SUNDAY. VARIOUS CONCERNS DURING THIS 6-DAY TIME FRAME INCLUDE POSSIBLE...BUT CERTAINLY NOT LIKELY THUNDERSTORM CHANCES MONDAY NIGHT...POTENTIAL FIRE WEATHER ISSUES ON TUESDAY AFTERNOON...AND THEN ADDITIONAL...FAIRLY LOW CONFIDENCE THUNDERSTORM CHANCES IN THE THURSDAY-FRIDAY NIGHT TIME FRAME. WILL DISCUSS THESE ELEMENTS FIRST...AND CONCLUDE WITH SOME DISCUSSION ABOUT TEMPERATURES... STARTING OFF RIGHT AWAY MONDAY EVENING...THE MILLION DOLLAR QUESTION IS WHETHER ANY POTENTIALLY STRONG TO SEVERE STORMS WILL AFFECT THE CWA...AS A COMPACT BUT VIGOROUS NEGATIVELY TILTED MID LEVEL SHORTWAVE SWINGS FROM THE WY/NEB PANHANDLE AREA AT 00Z...TO ND BY 12Z TUESDAY MORNING. DUE TO THE TRACK OF THE WAVE...CLEARLY THE STRONGEST FORCING WILL REMAIN NORTH OF THE CWA. IN ADDITION...12Z NAM PLAN VIEW CINH FIELDS AND FORECAST SOUNDINGS INDICATE CONSIDERABLE CAPPING TO NEAR-SURFACE BASED PARCELS...AS EVIDENCED BY 700MB TEMPS INITIALLY IN THE 6-8C RANGE. ALTHOUGH THE 12Z GFS INSISTS ON STORMS AFFECTING AT LEAST THE WESTERN 1/3 OR SO OF THE CWA...THE LAST TWO NAM RUNS AND ALSO 12Z ECMWF SKIRT CONVECTION JUST NORTH OF THE CWA IN THE EVENING...AND THEN RE-FOCUSING EASTWARD ALONG AN AXIS FROM IA TO EASTERN KS AFTER MIDNIGHT ALONG THE ADVANCING 850MB FRONT AND WITHIN THE LOW LEVEL JET AXIS. ALTHOUGH SEVERE PARAMETERS ARE NOT GREAT...NAM/GFS GENERALLY AGREE ON ELEVATED CAPE IN THE 500-1000 J/KG RANGE DURING THE NIGHT...AND 0-6KM DEEP LAYER SHEAR AROUND 40KT. CERTAINLY THIS COULD SUPPORT STRONG TO MARGINALLY SEVERE STORMS...WITH HAIL TO QUARTER SIZE REALLY THE MAIN THREAT...BUT GIVEN LOW CONFIDENCE IN COVERAGE WILL KEEP POPS AT ONLY 20 PERCENT FOR NOW ACROSS THE NORTHWEST 2/3 OF THE CWA BEFORE MIDNIGHT...AND THE SOUTHEAST 1/3 LATER IN THE NIGHT. TUESDAY THROUGH WEDNESDAY NIGHT...KEPT IT DRY CWA-WIDE...AS QUASI-ZONAL FLOW TAKES HOLD OF THE CENTRAL PLAINS...DRIER LOW LEVEL AIR INVADES...AND THE PRIMARY SURFACE FRONT AND RESULTANT INSTABILITY AXIS HANGS UP ACROSS THE SOUTHERN 2/3 OF KANSAS. THAT BEING SAID...WILL HAVE TO KEEP AN EYE ON MAINLY NORTH CENTRAL KS ZONES IN THE TUES NIGHT AND WED NIGHT TIME FRAMES IN CASE ANY CONVECTION BRUSHES INTO THE CWA NEAR MODEST LOW LEVEL JETS FOCUSES FARTHER SOUTH. THE MAIN ISSUE WILL BE FIRE WEATHER CONCERNS FOR TUESDAY AFTERNOON BEHIND THE IMPRESSIVE DRYLINE PASSAGE. WITH DEWPOINTS DECREASING/MIXING DOWN INTO THE 20S TO LOW 30S AT BEST TUESDAY AFTERNOON...HAVE RELATIVE HUMIDITIES FALLING DOWN INTO THE 15-20 PERCENT RANGE MOST AREAS. ALTHOUGH THIS IS FORECAST INTO RED FLAG WARNING CRITERIA...THE STRONGEST SUSTAINED WIND SPEEDS AROUND 20 MPH OR HIGHER SHOULD FOCUS ACROSS THE NORTHERN 1/2 OF THE CWA IN CLOSER PROXIMITY TO THE DEPARTING SURFACE LOW...WITH LIGHTER WINDS PREVALENT NEAR AND SOUTH OF THE STATE LINE. DESPITE THE RECENT GREEN-UP...THE OFFICIAL VEGETATIVE FUEL STATUS IS STILL FAVORABLE FOR FIRE GROWTH...AND THUS WE COULD EASILY BE HEADING TOWARD A RED FLAG WARNING ESPECIALLY FOR MUCH OF NEB ZONES. ALTHOUGH CONFIDENCE IN THE DETAILS GETS PROGRESSIVELY LOWER WITH TIME...VARIOUS THUNDERSTORM CHANCES IN THE 20-50 PERCENT RANGE ENTER THE CWA IN THE THURSDAY THROUGH FRIDAY NIGHT TIME FRAME...AS AT LEAST TWO FAIRLY LOW AMPLITUDE SHORTWAVES PROGRESS THROUGH THE QUASI-ZONAL FLOW...AND INTERACT WITH AT LEAST MODEST INCREASING INSTABILITY AS A SURFACE RIDGE AXIS MOVES EAST AND INSTABILITY RETURNS. AS IT CURRENTLY STANDS...THE OVERALL BEST RISK FOR MEASURABLE RAINFALL IS THURSDAY NIGHT MAINLY IN THE EAST...BUT THESE CHANCES COULD EASILY MIGRATE AROUND OR CHANGE...AS THE ECMWF AND GFS START TO GET VERY OUT OF PHASE WITH TIMING OF WAVES. WITH DEEP LAYER SHEAR CURRENTLY LOOKING MODEST...CERTAINLY NO OBVIOUS SEVERE WEATHER THREATS IN THIS TIME FRAME...BUT ISOLATED SEVERE NOT OUT OF THE QUESTION. FOR SATURDAY- SUNDAY...LEFT DRY AS MODELS GENERALLY AGREE ON SHORTWAVE RIDGING. CONCLUDING WITH A BRIEF DISCUSSION ON TEMPS FROM TUESDAY THROUGH SUNDAY...KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...WITH LOW-MID 70S ALL DAYS...BUT COULD FORESEE READINGS BY NEXT SUNDAY GETTING BOOSTED CLOSER TO 80 IF A RIDGE BUILDS AS ADVERTISED. REGARDING LOW TEMPS...DID MAKE SOME ADJUSTMENTS...GENERALLY NUDGING MANY AREAS DOWN 2-5 DEGREES FOR BOTH MON NIGHT AND TUES NIGHT AS DRIER AIR INVADES AND WINDS LIGHTEN. IN FACT...NOW HAVE MID-UPPER 30S ACROSS MUCH OF THE NORTHWEST CWA ON TUESDAY NIGHT. THAT BEING SAID...STILL NO LEGITIMATE FREEZING TEMPS IN SIGHT THROUGH THE NEXT WEEK. && .GID WATCHES/WARNINGS/ADVISORIES... NE...WIND ADVISORY FROM 1 PM TO 7 PM CDT MONDAY FOR NEZ039-040-046- 047-060>062-072>075-082>085. KS...WIND ADVISORY FROM 1 PM TO 7 PM CDT MONDAY FOR KSZ005>007- 017>019. && $$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
319 AM EDT MON MAR 26 2012 .SYNOPSIS... DRIER AND COOLER CONDITIONS WILL SETTLE IN TODAY AND TUESDAY AS HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES. A BRIEF WARMING TREND WILL ENSUE DURING THE MIDDLE OF THIS WEEK...FOLLOWED BY A COLD FRONT ON THURSDAY. NEAR SEASONABLE WEATHER THEN EXPECTED INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM MONDAY...THE COLD UPPER LOW IS NOW WELL EAST OF CAPE HATTERAS AND MOVING OUT TO SEA. OUR MID-LEVEL TEMPERATURES HAVE WARMED CONSIDERABLY SINCE THE DEPARTURE OF THE LOW AND A MUCH DRIER AND MORE STABLE ATMOSPHERE IS EXPECTED TODAY INTO TONIGHT. SURFACE HIGH PRESSURE JUST NORTH OF THE GREAT LAKES WILL PUSH A SECONDARY COLD FRONT SOUTH AND THROUGH THE EASTERN CAROLINAS LATE THIS AFTERNOON. ALTHOUGH THERE SHOULDN`T BE ANY CLOUDS WITH THIS FEATURE...NORTH-NORTHEAST WINDS TONIGHT WILL BRING A MUCH COOLER AIRMASS INTO THE REGION THAN WE HAVE SEEN IN NEARLY TWO WEEKS. RESIDUAL LOW CLOUDS THIS MORNING SWIRLING AROUND THE BACKSIDE OF THE UPPER LOW EXTEND ACROSS THE EASTERN HALF OF NORTH CAROLINA. ISENTROPIC ANALYSIS REVEALS SINKING PARCEL TRAJECTORIES WHICH SHOULD GRADUALLY ERODE THESE CLOUDS FROM WEST TO EAST THROUGH THE EARLY MORNING HOURS. AFTER 14Z (10 AM) SUNSHINE SHOULD BE BREAKING OUT EVEN IN THE WILMINGTON AREA...WITH SUNNY SKIES EXPECTED EVERYWHERE DURING THE LATE MORNING AND AFTERNOON. HIGHS SHOULD REACH THE 75-80 TODAY... WARMEST IN THE SOUTH CAROLINA PEE DEE REGION AND COOLEST ALONG THE NC EAST-FACING BEACHES. LOWS TONIGHT SHOULD FALL TO 43-48...COOLEST IN INTERIOR SOUTHEAST NORTH CAROLINA AND WARMEST NEAR THE SANTEE RIVER. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...GUIDANCE CONTINUES TO INDICATE THAT TUESDAY WILL BE THE FIRST BELOW CLIMO DAY SINCE MARCH 11 AS A WEDGE OF HIGH PRESSURE BUILDS AGAINST THE APPALACHIAN RANGE. ALTHOUGH MODELS HAVE BACKED OFF ON STRENGTH OF THE WEDGE...NE FLOW AT THE SURFACE WILL KEEP TEMPS BELOW...TO WELL BELOW...SEASONABLE NORMS...WITH THE COOLEST READINGS BEING IN THE CAPE FEAR REGION WHERE NE WINDS ADVECT OFF THE COOL OCEAN. ALTHOUGH SOUNDINGS ARE QUITE DRY TUESDAY...NOTE THAT FREQUENTLY MOISTURE IS UNDER-MODELED IN WEDGE SCENARIOS SO WILL INCREASE CLOUD COVER MORE THAN SUGGESTED BY PROFILES. MIXING WILL LIKELY ONLY REACH TO BELOW 900MB...AND LOW LEVEL 1000-900MB THICKNESSES SUPPORT TEMPS ONLY IN THE LOWER 60S NEAR WILMINGTON...TO AROUND 70 ACROSS THE PEE DEE REGION OF SC. HIGH DRIFTS OVERHEAD TUESDAY NIGHT ALLOWING FOR DECOUPLING IN THE LOWER ATMOSPHERE...AND CLEAR SKY CONDITIONS WILL ALLOW FOR DECENT RADIATIONAL COOLING. THE FLY-IN-THE-OINTMENT...AS IT IS...IS WHETHER SOME SLIGHT LOW LEVEL WAA BEGINS OVERNIGHT AS HIGH DRIFTS OFFSHORE...OR WHETHER WE CAN STAY PERFECTLY CALM. NEARLY ALL THE FORECAST PROFILES SUGGEST WARMING IN THE LOW LEVELS FROM 06Z-12Z WEDNESDAY AS LIGHT SOUTHERLY FLOW DEVELOPS AROUND DEPARTING HIGH PRESSURE. BELIEVE IT WILL BE TOUGH FOR SUCH SIGNIFICANT WARMING AFTER MANY HOURS OF NOCTURNAL INVERSION DEVELOPMENT...BUT WILL NOT DROP MINS AS LOW AS MAV NUMBERS...AND OPT FOR LOW 40S AREA WIDE...WITH THE COLDEST SPOTS POTENTIALLY TOUCHING 39. BY WEDNESDAY THE HIGH HAS DRIFTED OFFSHORE AND WARM SOUTHERLY RETURN FLOW COMES BACK INTO THE CAROLINAS. MOSTLY SUNNY SKY CONDITIONS WILL HELP RAISE TEMPS BACK TO ABOVE CLIMO...MID 70S AWAY FROM THE COAST...AND CONTINUED SOUTHERLY FLOW AT NIGHT WILL KEEPS TEMPS FROM FALLING MUCH OUT OF THE MID 50S AT NIGHT. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 300 AM MONDAY...MOST INTERESTING PART OF THE LONG TERM OCCURS LATE THURSDAY WITH A COLD FRONTAL PASSAGE...BEFORE COOL HIGH PRESSURE SETTLES IN TO THE WEEKEND. MODERATELY POTENT S/W TROUGH DIGS FROM THE GREAT LAKES THROUGH NEW ENGLAND THURSDAY...SUPPRESSING THE UPPER RIDGE AND DRIVING A COLD FRONT THROUGH THE CAROLINAS. STILL NOTING TIMING DIFFERENCES IN THE GUIDANCE...BUT FOR PERSISTENCE WILL CONTINUE TO FAVOR THE SLIGHTLY SLOWER ECMWF/CMC OVER THE GFS. NOT MUCH IN THE WAY OF MOISTURE RETURN AHEAD OF THIS...ALTHOUGH MID LEVEL THETA-E RIDGE DOES TRY TO ADVECT INTO OUR AREA JUST AHEAD OF FROPA...SO WILL CARRY SCHC POP FOR SHOWERS THURSDAY EVE/NIGHT. IF THE SLOWER SOLUTION COMES TRUE...850MB TEMPS RISE TO 11C WHICH SUPPORTS TEMPS AT OR ABOVE 80 MOST AREAS AWAY FROM THE BEACHES...AND THURSDAY WILL BE THE WARMEST DAY OF THE EXTENDED. IF...HOWEVER...A FASTER FROPA OCCURS...THIS WILL OBVIOUSLY CUT TEMPS BACK ESPECIALLY ACROSS THE NORTH...AND WOULD INCREASE THE LIKELIHOOD OF AFTN SHOWERS ALONG THE BOUNDARY. FOR NOW WILL STICK WITH THE SLOWER SOLUTION. COOL HIGH PRESSURE BUILDS ACROSS THE REGION FRI/SAT RETURNING THE AREA TO NEAR CLIMO TEMPS...POSSIBLY BELOW CLIMO WITH SOME NE FLOW ON FRIDAY. GFS/ECMWF THEN DIVERGE CONSIDERABLY ON EVOLUTION AND STRENGTH OF ANOTHER NORTHERN STREAM S/W DROPPING ACROSS THE MIDWEST RIDGE. GFS IS FASTER AND WEAKER...CONTINUING ITS TREND THIS YEAR...SO WILL BLEND ECMWF/GFS BUT WITH ADDITIONAL WEIGHT ON THE FORMER. THIS WILL BRING INCREASED CHANCES FOR RAIN THROUGH THE WKND AS LOW PRESSURE DEVELOPS NEAR THE OHIO VALLEY. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... AS OF 06Z...ALTHOUGH SHOWERS HAVE ENDED ACROSS SOUTH CAROLINA... RADAR AND THE LATEST HRRR MODEL SUGGEST IT`S NOT OVER FOR NORTH CAROLINA JUST YET. SHOWERS ROTATING SOUTHWARD ON THE BACK SIDE OF THE DEPARTING UPPER LEVEL LOW PRESSURE AREA WILL AFFECT THE ILM TERMINAL THROUGH 09Z...WITH EVEN A FEW LIGHT SHOWERS POSSIBLE IN THE LBT VICINITY THROUGH 0730Z OR SO. THERE IS SOME UNCERTAINTY WITH REGARDS TO CEILING HEIGHTS...MVFR SHOULD PREDOMINATE...BUT IFR IS NOT OUT OF THE QUESTION PARTICULARLY AFTER 08Z. AFTER DAYBREAK WINDS WILL PICK UP...GUSTING OVER 20 KTS BY MID MORNING. SKIES WILL BECOME NEARLY CLEAR AS THE UPPER LOW EXITS OFFSHORE. EXTENDED OUTLOOK...VFR MONDAY NIGHT THROUGH WEDNESDAY. POSSIBLE MORNING FOG THURSDAY AND FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM MONDAY...LOW PRESSURE HAS MOVED EAST OF THE NC OUTER BANKS AND WILL MOVE FARTHER OUT TO SEA TODAY. ATTENTION WILL TURN TO HIGH PRESSURE IN CANADA JUST NORTH OF THE GREAT LAKES THAT WILL BUILD SOUTH TOWARD THE CAROLINAS. AS THIS HIGH MOVES SOUTH IT WILL PUSH A DRY COLD FRONT THROUGH THE AREA LATE THIS AFTERNOON. NORTH- NORTHEAST WINDS WILL INCREASE BEHIND THIS FRONT...REACHING 15-20 KT BY LATE THIS EVENING AND CONTINUING OVERNIGHT. THERE IS SOME POTENTIAL SEAS COULD REACH 6 FEET IN THE WATERS NEAR FRYING PAN SHOALS DUE TO THEIR EXPOSED POSITION IN THIS WIND DIRECTION...BUT CONFIDENCE IS TOO LOW TO RAISE AN ADVISORY AT THIS TIME. ELSEWHERE SEAS 2-4 FEET TODAY SHOULD BUILD TO 3-5 FT TONIGHT AWAY FROM SHORE WITH THE INCREASED WIND SPEEDS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...NE SURGE ONGOING AT THE START OF THE PERIOD AROUND WEDGE OF HIGH PRESSURE. AT LEAST CAUTIONARY HEADLINES APPEAR LIKELY TO BE IN EFFECT TUESDAY MORNING WITH 15-20 KT WINDS CREATING 4-5 FT NE WIND WAVES CONTROLLING THE WAVE SPECTRUM. DURING TUESDAY...HIGH PRESSURE DRIFTS OVER THE WATERS SO WINDS/WAVES RAPIDLY DECREASE THROUGH THE DAY...WINDS BECOMING NEARLY CALM OVERNIGHT WHILE SEAS FALL TO 1-2 FT. GRADIENT INCREASES WEDNESDAY AS HIGH PRESSURE DRIFTS OFFSHORE AND A COLD FRONT APPROACHES FROM THE NW. THIS PUTS THE WATERS INTO A PRE FRONTAL REGIME...WITH SW WINDS INCREASING TO 15-20 KTS FORCING SEAS BACK UP TO 3-5 FT...AND CAUTIONARY HEADLINES MAY ONCE AGAIN BE NECESSARY. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 300 AM MONDAY...CAUTIONARY HEADLINES POSSIBLY ONGOING AT THE START OF THE PERIOD AS A COLD FRONT APPROACHES FROM THE NORTHWEST. SW WINDS OF 15-20 KTS WILL VEER AND WEAKEN THROUGH THE DAY...BECOMING NORTH AROUND 10 KTS THURSDAY NIGHT. SW WIND WAVES OF 3-5 FT EARLY THURSDAY FALL TO 2-3 FT BY FRIDAY MORNING. A PERIOD OF CONFUSED SEAS IS LIKELY THURSDAY EVE AS THE WAVE SPECTRUM FEATURES TWO DOMINANT WIND WAVES...ONE SLOWLY WEAKENING FROM THE SW...WHILE A BUILDING NE WIND WAVE DEVELOPS. N/NE WINDS LESS THAN 10 KTS FRIDAY KEEP SEAS ONLY AROUND 2 FT THROUGH THE DAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JDW NEAR TERM...TRA SHORT TERM...JDW LONG TERM...JDW AVIATION...TRA/DL MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
101 AM EDT MON MAR 26 2012 .SYNOPSIS... DRIER AND COOLER CONDITIONS WILL SETTLE IN TODAY AND TUESDAY AS HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES. A BRIEF WARMING TREND WILL ENSUE DURING THE MIDDLE OF THIS WEEK...FOLLOWED BY A COLD FRONT ON THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 130 AM MONDAY...THE HRRR MODEL APPEARS TO HAVE AN EXCELLENT HANDLE ON CURRENT PRECIPITATION COVERAGE AND MOVEMENT AND IS THE BASIS FOR OUR EARLY MORNING UPDATE. WE HAVE INCREASED RAIN CHANCES TO NEAR 100 PERCENT ACROSS PENDER COUNTY AND THE LOWER CAPE FEAR RIVER BASIN FOR THE NEXT FEW HOURS. RADAR COMPOSITES SHOW A LARGE AREA OF RAIN EXTENDING AS FAR INLAND AS KINSTON AND GOLDSBORO THAT WILL ROTATE SOUTH AROUND THE DEPARTING UPPER LEVEL AND SURFACE LOW PRESSURE. ISENTROPIC DOWNGLIDE SHOULD HELP THE SOUTHERN EDGE DETERIORATE AFTER 2-3 AM...WITH MOST OF THE RAIN OVER WITH BY 4-5 AM. NO OTHER CHANGES AT THIS TIME. PREVIOUS DISCUSSION FROM 11 PM SUNDAY FOLLOWS... PER LATEST ANALYSIS...5H CUTOFF LOW AND ASSOCIATED COLD POOL IS OFF THE SE NC COAST AND SHOULD BEGIN TO GAIN SOME FORWARD SPEED OVERNIGHT AS THE WESTERLIES BEGIN TO INTERACT AND SLOWLY ABSORB THIS UPPER LOW INTO THE MAIN WESTERLY BELT. MODELS INDICATE THE CUTOFF/CLOSED LOW OPENS UP INTO AN OPEN WAVE MONDAY AND THEN GETS CAUGHT UP IN THE MAIN WESTERLIES DURING THE OVERNIGHT. BY 12Z...MODELS INDICATE THE UPPER LOW NOW NEARLY AN OPEN WAVE...AND SHOULD BE WELL OFFSHORE FROM CAPE HATTERAS. OVERALL...LOOK FOR IMPROVING WX AND SLOWLY IMPROVING SKY CONDITIONS FROM SW TO NE...ESPECIALLY AFTER THE MIDNIGHT HOUR. WILL INDICATE PARTIAL CLEARING FOR BASIC SKY CONDITIONS DURING THE PRE-DAWN HRS. VARIOUS MODEL MOS GUIDANCE INDICATE CONTINUED DECENT CHANCE FOR PCPN WELL AFTER MIDNIGHT. HOWEVER...WITH THE LOSS OF DAYTIME HEATING... WEAKENING LAPSE RATES DUE TO THE COLD POOL PULLING AWAY...AND SUBSIDENCE ALOFT BECOMING MORE DOMINANT AS TIME GOES BY...HAVE STAYED CLOSER TO A DRIER FORECAST AFTER THE MIDNIGHT HOUR. HAVE TWEAKED MIN TEMPS LOWER GIVEN CAA AND MOST TEMPS ACROSS THE ILM CWA HAVING REACHED WITHIN A CAT OF FORECAST MINS ALREADY. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 1:20 PM SUNDAY...MID LEVEL AMPLITUDE WILL RELAX THROUGH THE PERIOD ESPECIALLY WHEN COMPARED TO THE PATTERN WE HAVE SEEN THE PAST FEW DAYS. FOCUS SHIFTS FROM THUNDERSTORMS AND INSTABILITY TO WHAT IS BECOMING AN INTERESTING TEMPERATURE FORECAST FOR WEDNESDAY MORNING. EARLY ON...A BROAD NORTHERLY FLOW WILL DEVELOP IN THE WAKE OF A SURFACE TROUGH MOVING ACROSS WITH THE MID LEVEL LOW. A SECONDARY SURGE OF COOLER AIR ARRIVES AROUND 0600 UTC TUESDAY. THE SURFACE HIGH MOVES FROM THE NORTHEAST TO ESSENTIALLY OVERHEAD EARLY WEDNESDAY. NO POPS OR EVEN LITTLE CLOUD COVER IS EXPECTED THROUGH THE PERIOD. THE NAM/MET GUIDANCE IS CONSIDERABLY COOLER WITH 38 DEGREES IN LUMBERTON AND 44 WITH THE MAV FOR WEDNESDAY MORNING. IT APPEARS THE GFS HAS SOME HIGH LEVEL MOISTURE MOVING ACROSS FROM THE NORTHWEST THAT MAY KEEP IDEAL RADIATIONAL CONDITIONS FROM DEVELOPING. HAVE TRIMMED BACK LOWS A BIT BUT OVERALL FORECAST CONTINUES TO LEAN HEAVILY TOWARD THE MAV/GFS. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 1:20 PM SUNDAY...LOW AMPLITUDE MID LEVEL FLOW ON WEDNESDAY WITH THE CAROLINAS ON THE SOUTHERN FRINGE OF A BELT OF WESTERLIES WHILE HIGH PRESSURE SITS OFF THE COAST. TEMPS BOUNCE BACK TO NORMAL AND CLOUD COVER SHOULD BE MINIMAL. MID LEVEL FLOW VEERS ON THURSDAY IN RESPONSE TO CONGEALING LOWS OFF CANADIAN MARITIMES AND A LARGELY MOISTURE-STARVED FRONT MANAGES TO PUSH THROUGH LATE IN THE DAY BUT NOT BEFORE A WARM AFTERNOON WITH HIGHS NEAR 80. FASTER TIMING OF THE FRONT IS POSSIBLE HOWEVER WHICH WOULD OBVIOUSLY LIMIT THE WARMTH AND COULD FAVOR A FEW TSTMS IF FROPA BETTER COINCIDES WITH PEAK HEATING. GUIDANCE AT ODDS WITH THE EXTENT OF BUILDING PRESSURES AND COLD AIR ADVECTION INTO THE CAROLINAS WITH RAMIFICATIONS RANGING FROM A RETURN TO CLIMO TEMPS TO DEVIATIONS BELOW CLIMO. EITHER WAY THIS HIGH APPEARS FATED TO WEAKEN AND MOVE OFF THE COAST FOR THE WEEKEND FAVORING A RETURN OF AT LEAST CLIMO TEMPERATURES. ISOLATED CONVECTION BORNE OF MESOSCALE PROCESSES CERTAINLY HARD TO RULE OUT BUT NO WIDESPREAD SYNOPTIC FORCING IS EXPECTED. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AS OF 06Z...ALTHOUGH SHOWERS HAVE ENDED ACROSS SOUTH CAROLINA... RADAR AND THE LATEST HRRR MODEL SUGGEST IT`S NOT OVER FOR NORTH CAROLINA JUST YET. SHOWERS ROTATING SOUTHWARD ON THE BACK SIDE OF THE DEPARTING UPPER LEVEL LOW PRESSURE AREA WILL AFFECT THE ILM TERMINAL THROUGH 09Z...WITH EVEN A FEW LIGHT SHOWERS POSSIBLE IN THE LBT VICINITY THROUGH 0730Z OR SO. THERE IS SOME UNCERTAINTY WITH REGARDS TO CEILING HEIGHTS...MVFR SHOULD PREDOMINATE...BUT IFR IS NOT OUT OF THE QUESTION PARTICULARLY AFTER 08Z. AFTER DAYBREAK WINDS WILL PICK UP...GUSTING OVER 20 KTS BY MID MORNING. SKIES WILL BECOME NEARLY CLEAR AS THE UPPER LOW EXITS OFFSHORE. EXTENDED OUTLOOK...VFR MONDAY NIGHT THROUGH WEDNESDAY. POSSIBLE MORNING FOG THURSDAY AND FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 130 AM MONDAY...SURFACE LOW PRESSURE IS EAST OF THE OUTER BANKS AND MOVING FARTHER OUT TO SEA. ONLY CHANGE TO THE FORECAST EARLY THIS MORNING WAS TO INCREASE RAIN CHANCES NORTH OF CAPE FEAR TO NEARLY 100 PERCENT AS RADAR INDICATES A LARGE BATCH OF RAIN ABOUT TO PUSH OFFSHORE. PRECIPITATION SHOULD REMAIN FAIRLY LIGHT...AND WILL BEGIN TO WRAP UP AFTER 4 AM. PREVIOUS DISCUSSION FROM 11 PM SUNDAY FOLLOWS... RAISED A SMALL CRAFT EXERCISE CAUTION FOR THE ILM NC WATERS ONLY. THE UPPER LOW AND ASSOCIATED SFC LOW TO SLIDE OFF CAPE HATTERAS LATE THIS EVENING...AND FURTHER OFFSHORE DURING THE PRE-DAWN MONDAY HRS. THE SFC PRESSURE PATTERN INDICATE WINDS WILL VEER FROM W TO NW DURING THE OVERNIGHT PERIOD. WIND SPEEDS WILL BE AROUND 15 KT...EXCEPT 15-20 KT ACROSS THE ILM NC WATERS. SEAS WILL RUN 2 TO 4 FT THRUOUT...WITH THE EXCEPTION OF 5 FOOTERS MAINLY RESERVED FOR THE OUTER WATERS FROM CAPE FEAR NORTHWARD. A 2 TO 4 FT 7 TO 8 SECOND PERIOD SOUTHERLY BORDERLINE SWELL WILL DOMINATE THE SIGNIFICANT SEAS. A 1 TO 3 FOOT WIND CHOP...WILL BLEND INTO THE SIG SEAS. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 1:20 PM SUNDAY...SOME STRONG WINDS AT THE BEGINNING OF THE PERIOD AS A SURFACE TROUGH WILL BE MOVING OFFSHORE. EXPECT A NORTHERLY FLOW AT 20-25 KNOTS. GRADIENT DECREASES SLOWLY DURING THE DAY ONLY TO INCREASE ONCE AGAIN AROUND 0600 UTC TUESDAY AS A SECONDARY FRONT/SURGE MOVES ACROSS. WINDS TURN MORE NORTHEAST AND INCREASE ONCE AGAIN TO A RANGE OF 20-25 KNOTS. GRADIENT DIMINISHES DRAMATICALLY LATE TUESDAY/EARLY WEDNESDAY AS THE CENTER OF HIGH PRESSURE;RE MOVES FROM PENNSYLVANIA TO BASICALLY OVERHEAD. WINDS STAY JUST BELOW SMALL CRAFT CRITERIA EARLY MONDAY AND AGAIN EARLY TUESDAY. SEAS MAY ECLIPSE SIX FEET BRIEFLY TUESDAY BUT WILL NOT ISSUE A HEADLINE AT THIS TIME DUE TO THE MARGINAL NATURE AND TIME CONSIDERATIONS. SEAS FOLLOW THE WINDS TUESDAY DECREASING DRAMATICALLY. LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 1:20 PM SUNDAY...BERMUDA HIGH PRESSURE TO BRING A SOUTHWESTERLY WIND WEDNESDAY THAT MAY VEER WITH THE APPROACH/DEVELOPMENT OF SOME WEAK PIEDMONT TROUGHINESS. THIS MAY ALSO LEAD TO JUST ENOUGH OF AN UPTICK OF CONDITIONS THAT CAUTIONARY HEADLINES ARE NEEDED. THESE FACTORS REMAIN IN PLACE ON THURSDAY WHILE A COLD FRONT WHOSE TIMING IS A LITTLE UNCERTAIN APPROACHES FROM THE NNW. THE APPROACH OF THIS BOUNDARY MAY CAUSE ADDITIONAL VEERING THROUGH THURSDAY DEPENDING ON ITS SPEED AND TIME OF ARRIVAL. ASSUMING A THURSDAY EVENING FROPA A TURN TO A MORE NORTHERLY DIRECTION IS EXPECTED ON FRIDAY AND THE SURGE BEHIND THE FRONT ALSO WILL BE QUESTIONABLE...IN STRENGTH. THIS WILL END UP DICTATING WHETHER FRIDAY SEES A SLIGHT DETERIORATION IN WIND AND SEAS OR AN ACTUAL IMPROVEMENT OVER THURSDAY SHOULD THE WEAKER SOLUTIONS PAN OUT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK/TRA NEAR TERM...DCH/TRA SHORT TERM...SHK LONG TERM...MBB AVIATION...HDL/TRA
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
457 AM CDT MON MAR 26 2012 .SHORT TERM...TODAY AND TUESDAY. ACTIVE PERIOD EXPECTED...WITH CONCERNS ON PCPN AND TYPE AND TEMPERATURES. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE OUT OF CANADA NOSING SOUTH INTO WI. FEW PATCHES OF LOW CLOUDS CONTINUE TO FLOAT IN OFF LAKES. TO SOUTHWEST MID CLOUDS COVER THE AREA...WITH FEW LIGHT SHOWERS MOVING THROUGH SOUTHERN WI ASSOCIATED WITH AN AREA OF FGEN FORCING. FREEZE WARNING WILL REMAIN AS IS. FORECAST ATTENTION ON SIG SHORT WAVE LIFTING NORTHEAST OUT OF WESTERN TROF INTO THE DAKOTAS BY TUE MORNING. AT THE SURFACE...HIGH AND ASSOCIATED COLD AIR MASS TO MOVE EAST TODAY WITH COLD FRONT RETURNING NORTH AS A WARM FRONT TONIGHT. AREA OF STEEP MID LEVEL LAPSE RATES/LI`S NEAR 0 SHIFTS EAST INTO REGION TONIGHT...WITH ELEVATED THUNDER POSSIBLE OVERNIGHT. LOW LEVEL FLOW INCREASES TO 40KTS...FOCUSED OVER NORTH THUS HIGHER POPS OVER NORTHERN CWA. SOUNDINGS INDICATE DRY LAYER BELOW 800MB HAS TO BE OVERCOME THIS EVENING...TRENDED POPS LOWER EAST BEFORE MIDNIGHT. PCPN TYPE ALSO IN QUESTION. DEPTH OF THE BELOW FREEZING LAYER ON SOUNDINGS DEEP ENOUGH TO REFREEZE...WHILE CONVECTION ALSO SUGGESTS SLEET. THOUGH CAN NOT TOTALLY RULE OUT FZRA. TEMPERATURES EXPECTED TO BE JUST BELOW FREEZING FOR LOWS...THEN WARM TOWARD MORNING... LIMITING ZR. WILL NOT PUT ZR IN GRIDS ATTM AND PASS CONCERNS REGARDING IT ON TO NEXT SHIFT. COLD FRONT TO MOVE INTO CWA LATE IN DAY TUE. MODELS SUGGEST POSSIBLE CONVECTION OUT AHEAD OF FRONT. INSTABILITY LIMITED WITH DEW POINTS ONLY RISING INTO THE LOWER 50S. INSTABILITY MAINLY FOCUSED TO OUR SOUTH AND WEST. STRONG SOUTH TO SOUTHEAST FLOW WILL ALSO BE A STABILIZING FACTOR AND LIMIT TEMPERATURES IN THE EAST. HAVE BACKED POPS BACK DOWN INTO SCATTERED RANGE FOR TUE. .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY. LOW PRESSURE ACROSS SOUTHWEST ONTARIO WILL MOVE EAST SOUTHEAST TO NORTH OF LAKE HURON BY 12Z WEDNESDAY MORNING. COLD FRONT WILL MOVE RAPIDLY EAST OF THE STATE TUESDAY NIGHT. BEEN CONTEMPLATING IF A SMALL CHANCE WOULD BE NEEDED ACROSS THE EAST. DO THINK IF ANY ACTIVITY DOES FORM TUESDAY AFTERNOON...IT WILL RACE RAPIDLY TO THE NORTHEAST AND BE OUT OF OUR FORECAST AREA BY 00Z. SOME CONCERNS TONIGHT THAT THE MODELS ARE UNDER DOING THE WINDS TUESDAY NIGHT. VERY STRONG WINDS AT 925MB...COMBINED WITH SOME SUBSIDENCE BEHIND THE COLD FRONT AND 850MB COLD ADVECTION SHOULD HELP MIX SOME OF THE STRONGER WINDS ALOFT DOWN TO THE SURFACE. HAVE GONE WITH BLUSTERY WORDING FOR NOW IN THE ZONES. WOULD NOT BE SURPRISED IF A FEW GUSTS TO OVER 30 KNOTS ARE POSSIBLE TUESDAY EVENING. WINDS SHOULD GRADUALLY DIMINISH OVERNIGHT. ON WEDNESDAY...CONTINUED CHANCES FOR RAIN OR SNOW OVER FAR NORTH CENTRAL WISCONSIN. ON THE 00Z MODEL RUNS TONIGHT...BOTH THE GFS/WRF INDICATING 500MB TROUGH MOVING ACROSS NORTHEAST WISCONSIN WHILE THE BOTH MODELS DO SHOW SOME SURFACE CONVERGENCE ALONG A WEAK TROUGH/COLD FRONT. DID EXPAND PRECIPITATION CHANCES FURTHER SOUTH AND NOW INCLUDES MOST OF THE FORECAST AREA EXCEPT THE VERY FAR SOUTHWEST. HIGH PRESSURE WILL BUILD INTO NORTH CENTRAL AND NORTHEAST WISCONSIN WEDNESDAY NIGHT. WITH RIDGE AXIS OVERHEAD BY 12Z THURSDAY...A WIDESPREAD FREEZE IS LIKELY ACROSS THE NORTH AWAY FROM THE BAY WITH AREAS OF FROST OVER THE REMAINDER OF THE FORECAST AREA. WITH THE RECENT RECORD WARMTH...THE GROWING SEASON HAS STARTED VERY EARLY ACROSS WISCONSIN. HAVE ADDED FROST TO THE FORECAST TO INDICATE THE POTENTIAL FOR MORE TEMPERATURES AT OR BELOW FREEZING. NEXT SYSTEM WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA THURSDAY NIGHT INTO FRIDAY. NEXT WEEKEND STILL LOOKS MUDDLED BETWEEN THE MODELS...THEREFORE NO CHANGES TO THE FORECAST. && .AVIATION...THE MAIN AREA OF MVFR CIGS THAT WAS OVER THE UPPER PENINSULA EARLIER IN THE EVENING DISSIPATED AS IT MOVED INTO NE WI...BUT PATCHY LOW CLOUDS CONTINUED TO DEVELOP OVER THE LAKE/BAY AND MOVE INTO NE/EC WI. HAVE BACKED OFF ON PREVAILING MVFR CIGS AT ANY OF THE TAF SITES...BUT KEPT TEMPO GROUPS FOR BKN015-020 AT ATW/GRB THROUGH 12Z/MON. MID-LEVEL CLOUDS CONTINUED TO STREAM INTO CENTRAL WI LATE THIS EVENING...BUT SHOWERS OVER SE MN SHOULD STAY TO OUR SOUTHWEST THROUGH MONDAY. SCT SHOWERS WILL PUSH INTO THE REGION ON MONDAY EVG AS THE NEXT SYSTEM APPROACHES. IN ADDITION...SOME LLWS IS EXPECTED TO DEVELOP AT RHI/AUW/CWA LATE MONDAY EVENING. KIECKBUSCH && .MARINE...SMALL CRAFT WILL BE ALLOWED TO RUN THROUGH 15Z. WINDS HAVE DROPPED BELOW CRITERIA...THOUGH WAVES WILL BE SLOWER TO DROP OFF. INCREASING SOUTHEAST...SOUTH WINDS EXPECTED TONIGHT AS LLVL FLOW INCREASES TO 40KTS AT 925MB. UNDER WAA REGIME HAVE CONCERNS THAT A STRONG INVERSION WILL LIMIT MIXING OF HIGHER WINDS DOWN...WITH GFS SOUNDINGS SUGGESTING SAME. WILL STAY WITH STRONG SMALL CRAFT WORDING AT THIS TIME. && .GRB WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING UNTIL 9 AM CDT THIS MORNING FOR WIZ005-010>013- 018-019-021. && $$ TE/ECKBERG
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1149 PM CDT SUN MAR 25 2012 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND MONDAY. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE COLD FRONT DROPPING INTO NORTHERN ILLINOIS EARLY THIS AFTERNOON WHILE CANADIAN HIGH PRESSURE IS BUILDING SOUTH INTO THE NORTHERN MISSISSIPPI VALLEY. LOW STRATO-CU DISSIPATED RATHER QUICKLY EARLIER TODAY AS MIXING INTO DRIER AIR OVERWHELMED THE SHALLOW COOL AND MOIST AIRMASS. STILL SOME LINGERING CU OVER EAST-CENTRAL WISCONSIN...THOUGH TRENDS SUPPORT IT DISSIPATING AS WELL OVER THE NEXT COUPLE HOURS. UPSTREAM IS PRETTY QUIET...WITH ONLY MID AND HIGH CLOUDS PUSHING ACROSS THE DAKOTAS. AS HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION TONIGHT...LOW TEMPS AND HEADLINES ARE THE MAIN FORECAST CONCERNS. TONIGHT...LAST NIGHTS COLD FRONT WILL CONTINUE TO SAG SOUTH TOWARDS THE OHIO VALLEY WHILE CANADIAN HIGH PRESSURE WILL BUILD INTO SOUTHERN ONTARIO AND THE WESTERN GREAT LAKES. THIS INCOMING AIRMASS FROM CANADA IS QUITE DRY AND WILL DROP PWATS TO UNDER A QUARTER OF AN INCH. THOUGH AIRMASS IS VERY DRY...NOT IDEAL RADIATIONAL COOLING CONDITIONS WILL BE IN PLACE FOR TONIGHT. WILL HAVE SCT-BKN MID AND HIGH CLOUDS ARRIVE FROM THE NORTHERN PLAINS INTO MUCH OF CENTRAL AND EAST-CENTRAL WISCONSIN BY LATE THIS EVENING. THE PRESSURE GRADIENT WILL ALSO REMAIN FAIRLY TIGHT OVER NE WISCONSIN WHERE NE WINDS FUNNELED DOWN THE BAY...AND ALSO OFF LAKE MICHIGAN WILL KEEP THE BL RATHER BREEZY. NORTH-CENTRAL WISCONSIN WILL SEE 1000-850MB WINDS AROUND 15 KTS...WHICH IS RIGHT ON THE EDGE FOR DECOUPLING. AM GOING TO LEAN TOWARDS DECOUPLING OCCURRING...DUE TO SANDY SOIL EFFECTS AND CLOUDS SHIFTING SOUTH THROUGH THE NIGHT. AS A RESULT...MID TWENTY LOWS SEEM PERFECTLY REASONABLE UP NORTH...AND SEE LITTLE REASON TO ADJUST HEADLINES. DID RAISE LOWS A DEGREE OR TWO OVER CENTRAL AND EAST-CENTRAL WISCONSIN BECAUSE OF CLOUDS AND WIND. LOWS IN THE LOWER TO MIDDLE 30S HERE. MONDAY...MID-LEVEL CLOUDS WILL STALL OVER SW WISCONSIN TOMORROW MORNING AND WILL RETURN NE IN THE AFTERNOON WHEN THE COLD FRONT STARTS RETURNING NORTH. NE WISCONSIN WILL SEE A MOSTLY SUNNY DAY...BUT CENTRAL AND NORTH-CENTRAL WISCONSIN WILL SEE A GRADUAL INCREASE IN CLOUDS. HIGHS RANGING FROM THE LOWER TO MIDDLE 40S EVERYWHERE. .LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY. THE WEATHER WILL BE MORE SEASONABLE THAN THE LAST TWO WEEKS WITH FLATTER ALMOST ZONAL FLOW OVER MUCH OF THE REGION THROUGH FRIDAY. SIGNIFICANT MODEL DIFFERENCES FOR NEXT SATURDAY AND SUNDAY WITH HIGH AMPLITUDE FLOW EXPECTED NEXT WEEK. UPPER TROUGH LIFTING NORTHEAST THROUGH THE NORTHERN PLAINS MONDAY NIGHT WILL BRING SHOWERS AND ELEVATED THUNDERSTORMS MONDAY NIGHT AND EARLY TUESDAY. THERE MIGHT BE ENOUGH COLD AIR FOR SLEET TO BE MIXED IN ACROSS THE NORTHERN PART OF THE FORECAST AREA. A COLD FRONT MOVES THROUGH TUESDAY AFTERNOON OR EVENING ACCOMPANIED BY STRONG WINDS IN THE LOW LEVELS...LOTS OF SHEAR AND DECENT UPPER SUPPORT. MOISTURE SHOULD BE LACKING THOUGH WHICH WILL LIMIT INSTABILITY. THERE IS SOME CHANCE OF SEVERE THUNDERSTORMS IF MOISTURE IS MORE PLENTIFUL THAN CURRENTLY EXPECTED. COOLER WEATHER IS EXPECTED FOR WEDNESDAY NIGHT THROUGH FRIDAY AS CANADIAN HIGH SINKS SOUTH INTO THE GREAT LAKES. WILL LIKELY HAVE SOME SUB FREEZING NIGHTS...WHICH IS COMPLETELY NORMAL FOR THIS TIME OF THE YEAR...BUT MORE OF A CONCERN THIS YEAR DUE TO UNUSUAL WARMTH THAT HAS STARTED AN EARLY GROWING SEASON. BIG DIFFERENCES FOR NEXT SATURDAY AND SUNDAY WITH THE GFS AND ECMWF ALMOST 180 DEGREES OUT OF PHASE OVER OUR AREA. && .AVIATION...THE MAIN AREA OF MVFR CIGS THAT WAS OVER THE UPPER PENINSULA EARLIER IN THE EVENING DISSIPATED AS IT MOVED INTO NE WI...BUT PATCHY LOW CLOUDS CONTINUED TO DEVELOP OVER THE LAKE/BAY AND MOVE INTO NE/EC WI. HAVE BACKED OFF ON PREVAILING MVFR CIGS AT ANY OF THE TAF SITES...BUT KEPT TEMPO GROUPS FOR BKN015-020 AT ATW/GRB THROUGH 12Z/MON. MID-LEVEL CLOUDS CONTINUED TO STREAM INTO CENTRAL WI LATE THIS EVENING...BUT SHOWERS OVER SE MN SHOULD STAY TO OUR SOUTHWEST THROUGH MONDAY. SCT SHOWERS WILL PUSH INTO THE REGION ON MONDAY EVG AS THE NEXT SYSTEM APPROACHES. IN ADDITION...SOME LLWS IS EXPECTED TO DEVELOP AT RHI/AUW/CWA LATE MONDAY EVENING. KIECKBUSCH && .MARINE... A WARM FRONT WILL PUSH NORTHWARD ACROSS THE AREA TUESDAY. GUSTS TO NEAR GALE FORCE FROM THE SOUTHEAST/SOUTH ARE POSSIBLE ON TUESDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING UNTIL 9 AM CDT MONDAY FOR WIZ005-010>013-018-019- 021. && $$
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1152 PM MDT SUN MAR 25 2012 .AVIATION...06Z TAFS CONFIDENCE GROWING THAT STRATUS WILL RETURN TO THE PANHANDLE LATER THIS EVENING. LATEST HRRR MODEL RUN SHOWING CDR...AIA AND SNY GOING DOWN BELOW IFR CONDITIONS IN SOUTHEAST UPSLOPING WINDS AROUND 09Z OR SO. VERY CLOSE T/TD SPREAD ALREADY GETTING SOME FOG DEVELOPMENT AT AIA AND SNY. SO FEEL PRETTY GOOD THAT THEY WILL GO DOWN FROM 09Z TO 15-16Z OR SO. AS FOR THE REST OF THE TAF PERIOD...EXPECT WINDS TO REALLY RAMP UP AS A COLD FRONT APPROACHES CENTRAL WYOMING AROUND NOON TIME MONDAY. ALL AIRPORTS WILL HAVE WIND ISSUES AFTER 18Z OR SO. CLAYCOMB && .PREV DISCUSSION... /ISSUED 611 PM MDT SUN MAR 25 2012/ UPDATE... DENSE CLOUDS HAVE KEPT TEMPERATURES AND GUSTY WINDS DOWN ACROSS AREAS WHERE FUELS ARE REPORTED CURED. COOLER TEMPERATURES AND LESS WINDS HAVE ALLEVIATED ANY FIRE DANGERS TODAY. THUS THE RED FLAG WARNINGS HAVE BEEN CANCELLED A LITTLE WHILE AGO. ATTENTION TURNS TO MONDAY WITH A WIDESPREAD STRONG WIND EVENT UNFOLDING. WENT AHEAD UPGRADED THE FIRE WEATHER WATCHES TO RED FLAG WARNINGS FOR AREAS EAST OF THE LARAMIE RANGE OUT INTO THE PANHANDLE. UPDATES HAVE BEEN SENT. CLAYCOMB AVIATION...00Z TAFS MAIN CONCERN FOR SOUTHEAST WYOMING AND NEBRASKA PANHANDLE AIRPORTS MONDAY LOOK TO BE WINDS. A POWERFAL...YET DRY PACIFIC LOW PRESSURE SYSTEM SET TO MOVE INTO WESTERN WYOMING TONIGHT...CREATING VERY STRONG WINDS ACROSS SOUTHEAST WYOMING BY MORNING. THESE WINDS WILL SPREAD OUT INTO THE PANHANDLE TOMORROW AFTERNOON. STARTUS LOOKS TO RETURN TO THE PANHANDLE OVERNIGHT WITH THE HRRR FORECASTING IFR CEILINGS AROUND 07Z OR SO. HAVE DELAYED ONSET SOME...BUT WILL GET A BETTER GRASP ON THE 06Z TAFS. CLAYCOMB PREV DISCUSSION... /ISSUED 301 PM MDT SUN MAR 25 2012/ SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT... TONIGHT...ANOTHER MILD NIGHT WITH WARM AIRMASS IN PLACE ALONG WITH DECENT MIXING AND LOW LEVEL MOISTURE HANGING IN...ESPECIALLY EAST OF INTERSTATE 25. LOW TEMPERATURES SOME 15 TO 20 DEGREES ABOVE NORMAL. BOUNDARY LAYER RELATIVE HUMIDITY AND LOW LEVEL WINDS BACKING TO SOUTHEAST WILL AID IN FOG AND LOW CLOUD FORMATION NORTH OF A LUSK TO ALLIANCE LINE AFTER MIDNIGHT. MONDAY...IMPRESSIVELY STRONG NEGATIVELY TILTED SHORTWAVE TROUGH MOVES TO EASTERN WYOMING IN THE AFTERNOON AS ITS ASSOCIATED POWERFUL PACIFIC ORIGIN COLD FRONT MOVES QUICKLY WEST TO EAST ACROSS OUR COUNTIES FROM LATE MORNING THROUGH LATE AFTERNOON. ALL FACTORS POINTING TO A WIDESPREAD HIGH WIND EVENT AFTER COLD FRONTAL PASSAGE...THUS WE HAVE UPGRADED THE HIGH WIND WATCH TO A HIGH WIND WARNING DUE TO HIGH CONFIDENCE AND ALSO TO GIVE OUR CUSTOMERS AN EARLY HEADS UP ON THE STRONG WINDS. COMBINATION OF STRONG DOWNWARD MOTION INDICATED ON THE 500-300 MB AND 700-500 MB QG PROGS...ALONG WITH PROGGED SURFACE THROUGH 700 MB GRADIENTS... STRONG COLD AIR ADVECTION AND PERFECT TIMING ON COLD FRONTAL PASSAGE SUGGEST A HIGH LIKELIHOOD OF A WIDESPREAD HIGH WIND EVENT IN THE AFTERNOON AND EARLY EVENING. EVEN 700 MB WINDS PROGGED FROM 50-65 KNOTS AFTER COLD FRONTAL PASSAGE AND THESE WINDS WILL BE TRANSPORTED TO THE SURFACE DUE TO DOWNWARD MOMENTUM TRANSFER FROM SUBSIDENCE AFTER THE SHORTWAVE TROUGH PASSAGE. ALTHOUGH LOW AND MID LEVEL MOISTURE WILL BE QUITE SCANT...THERE SHOULD BE ENOUGH FOR AT LEAST ISOLATED AFTERNOON THUNDERSTORMS NORTH OF A LARAMIE TO CHADRON LINE. QUITE A VARIANCE IN NAM AND GFS PROGGED HIGH TEMPERATURES AT SOME LOCATIONS...WILL BLEND IN THE MIDDLE AND BLEND WITH OUR NEIGHBORING OFFICES FOR THE MOST LIKELY FORECAST. MONDAY NIGHT...WITH THE PROGGED SURFACE THROUGH 700 MB GRADIENT AND STRONG COLD AIR ADVECTION CONTINUING INTO THE EVENING AS WELL AS DECENT DOWNWARD MOTION INDICATED ON THE 500-300 MB AND 700-500 MB QG PROGS...WILL EXTEND THE HIGH WIND WARNING UNTIL 9 PM...THEN WINDS SHOULD SUBSIDE UNDER HIGH WIND CRITERIA...THOUGH WOULD NOT BE SURPRISED TO SEE A FEW LOCATIONS CONTINUE HIGH WINDS BEYOND 9 PM. TUESDAY...ZONAL FLOW ALOFT...WEST TO EAST...AND WEAKER SURFACE THROUGH 700 MB GRADIENTS...ALONG WITH LIMITED LOW AND MID LEVEL MOISTURE WILL PRODUCE ANOTHER MILD AND DRY DAY. TUESDAY NIGHT...LOW AMPLITUDE SHORTWAVE RIDGING ALOFT WILL PROMOTE LIGHT SOUTH TO SOUTHWEST WINDS AND A MILD NIGHT WITH LOW TEMPERATURES ABOUT 10 DEGREES ABOVE NORMAL. LONG TERM...WEDNESDAY THROUGH SUNDAY...THERE ARE SOME DIFFERENCES BETWEEN THE 00Z AND 12Z MEDIUM RANGE MODEL GUIDANCE...BUT NOT SIGNIFICANT FOR MAJOR CHANGES TO THE GOING FORECAST. THE TREND OF UNSEASONABLY MILD TEMPERATURES AND DRY CONDITIONS WILL CONTINUE... WHICH WILL MAINTAIN THE WILDLAND FIRE DANGER. AN UPPER RIDGE WILL MOVE EAST ACROSS THE REGION WEDNESDAY...AND INTO THE PLAINS ON THURSDAY. ON WEDNESDAY...MINIMUM RELATIVE HUMIDITIES FALL TO CRITICAL LEVELS...HOWEVER WINDS EAST OF THE LARAMIE RANGE SHOULD NOT REACH CRITERIA. AREAS ALONG AND WEST OF THE RANGE WILL MEET WIND CRITERIA BUT FUELS ARE NOT READY FOR RAPID FIRE GROWTH. THIS COULD CHANGE DURING THE COURSE OF THE WEEK WITH THE LACK OF MOISTURE AND CONTINUED GUSTY WEST TO SOUTHWEST WINDS. LOW RELATIVE HUMIDITIES ARE EXPECTED THURSDAY AND FRIDAY AFTERNOON...WITH THE GUSTY WINDS AFFECTING THE REMAINDER OF THE EASTERN PLAINS AND ADJACENT WESTERN NEBRASKA PANHANDLE. FOR THE UPCOMING WEEKEND... THE FLOW ALOFT BACKS TO THE SOUTHWEST AND AMPLIFIES IN ADVANCE OF THE NEXT UPPER TROUGH MOVING INTO THE PACIFIC NORTHWEST. A PACIFIC LOW PRESSURE SYSTEM AND COLD FRONT APPROACHES THE REGION SUNDAY... WITH PRECIPITATION SPREADING EAST ACROSS THE CWA SUNDAY NIGHT. AVIATION...18Z TAF ISSUANCE...IFR CEILINGS SLOW TO SCATTER AT SIDNEY...BUT SHOULD DO SO BY MID AFTERNOON AS SOUTH TO SOUTHEAST BOUNDARY LAYER WINDS INCREASE. ELSEWHERE...EXPECT VFR CONDITIONS WITH SCATTERED TO BROKEN HIGH CLOUDS. SOUTHERLY SURFACE WINDS WILL BE BREEZY AT TIMES...ESPECIALLY FOR THE SOUTHEAST WYOMING AIRFIELDS AND SCOTTSBLUFF WHERE GUSTS OF 20 TO 25 KT WILL BE POSSIBLE. LOW LEVEL SOUTHEASTERLY FLOW WILL TRANSPORT SOME MOISTURE INTO THE WESTERN PANHANDLE LATER TONIGHT...WITH THE POSSIBILITY OF MVFR TO LOCAL IFR CEILINGS AND VISIBILITIES IN LOW STRATUS AND PATCHY FOG. BEST CHANCE FOR THESE CONDITIONS WILL BE FROM CHADRON THROUGH ALLIANCE AND SIDNEY. FIRE WEATHER...MINIMUM AFTERNOON HUMIDITIES TODAY WILL RANGE FROM 10 TO 20 PERCENT ACROSS SOUTHEAST WYOMING WITH GUSTY WINDS UP TO 30 MPH. CRITICAL FIRE WEATHER CONDITIONS WILL OCCUR ON MONDAY AS A STRONG PACIFIC ORIGIN COLD FRONT SWEEPS ACROSS THE DISTRICT FROM LATE MORNING THROUGH AFTERNOON...ALONG WITH STRONG WINDS AND LOW RELATIVE HUMIDITIES. WINDS WILL SUBSIDE MONDAY EVENING. MORE NEAR CRITICAL FIRE WEATHER CONDITIONS WILL OCCUR TUESDAY INTO THE WEEKEND WITH LOW RELATIVE HUMIDITIES AND GUSTY WINDS SOME OF THE AFTERNOONS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...RED FLAG WARNING FROM 10 AM MONDAY TO 7 PM MONDAY FOR WYZ101- WYZ102-WYZ106-WYZ107-WYZ108-WYZ116-WYZ117-WYZ118-WYZ119. HIGH WIND WARNING FROM 2 PM MONDAY TO 9 PM MONDAY FOR WYZ101- WYZ102-WYZ106-WYZ107-WYZ108-WYZ116-WYZ117-WYZ118-WYZ119. HIGH WIND WARNING FROM 11 AM MONDAY TO 9 PM MONDAY FOR WYZ104- WYZ105-WYZ109-WYZ110-WYZ111-WYZ113-WYZ115. NE...HIGH WIND WARNING FROM 2 PM MONDAY TO 9 PM MONDAY FOR NEZ002- NEZ003-NEZ019-NEZ020-NEZ021-NEZ054-NEZ055-NEZ095-NEZ096. RED FLAG WARNING FROM 10 AM MONDAY TO 7 PM MONDAY FOR NEZ002- NEZ003-NEZ019-NEZ020-NEZ021-NEZ054-NEZ055-NEZ095-NEZ096. && $$ SHORT TERM/FIRE WEATHER...RUBIN LONG TERM/AVIATION...JAMSKI
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
516 AM CDT MON MAR 26 2012 .DISCUSSION... 325 AM...WEAK UPPER WAVE SHIFTING SOUTHEAST ACROSS SOUTHERN MN AND SOUTHWEST WI EARLY THIS MORNING WITH AN AREA OF SHOWERS AND A FEW TS. MODELS SEEM CONSISTENT THAT THIS WILL PUSH INTO NORTHWEST IL LATER THIS MORNING. WHILE QPF AMOUNTS WILL BE LIGHT PERHAPS MANY AREAS ONLY SEEING A TRACE...HAVE INCLUDED A CHANCE OF SHOWERS WITH COVERAGE EXPECTED TO DECREASE INTO THE AFTERNOON HRS. DESPITE THE LOW PRECIP CHANCES...APPEARS MOSTLY CLOUDY SKIES WILL PREVAIL THROUGH MUCH OF THE DAY WHICH WILL LIMIT HEATING AS TEMPS ARE NOW FALLING THROUGH THE 40S WITH MANY LOCATIONS ALREADY INTO THE UPPER 30S. STILL EXPECT SOME SUN ACROSS THE SOUTHERN CWA BUT TEMPS ACROSS THE NORTH A BIT TRICKY. OVERALL ONLY TWEAKED THEM LOWER A DEGREE OR TWO BUT THERE IS THE POTENTIAL FOR TEMPS TO BE COOLER THAN CURRENTLY ADVERTISED. FLOW TURNS BACK SOUTHERLY TONIGHT AND COULD BE SOME WARM AIR ADVECTION PRECIP OVERNIGHT INTO EARLY TUESDAY MORNING BUT APPEARS THE BULK OF THIS ACTIVITY WOULD REMAIN NORTH OF THE CWA. BUT SIMILAR TO TODAY/S WAVE...LOOKS LIKE THERE WILL BE PLENTY OF CLOUD COVER AT LEAST ACROSS NORTHERN IL. COULD SEE A QUICK DROP IN TEMPS THIS EVENING AND DEPENDING ON HOW EXTENSIVE CLOUD COVER BECOMES... COULD BE SOME FROST ACROSS THE EASTERN CWA/NORTHWEST INDIANA WHERE LOWS COULD BE IN THE MID 30S. TOO MUCH UNCERTAINTY FOR ANY HEADLINES THIS MORNING AND WILL LET THE DAY SHIFT TAKE A LOOK AT THIS POTENTIAL MORE CLOSELY. LOW PRESSURE WILL LIFT ACROSS THE NORTHERN PLAINS TUESDAY AND ACROSS THE UPPER LAKES TUESDAY NIGHT WITH A TRAILING COLD FRONT SWEEPING ACROSS THE AREA LATE TUESDAY AFTERNOON INTO EARLY WEDNESDAY MORNING. MODELS ARE IN FAIRLY GOOD AGREEMENT WITH MOISTURE POOLING JUST AHEAD OF THIS FRONT WITH A TONGUE OF DEWPOINTS IN THE THE MID/UPPER 50S. POTENTIAL FOR SEVERE STORMS WILL BE PARTIALLY LIMITED BY STRONG FORCING FROM THIS AREA NORTH AND BEST INSTABILITY FROM THIS AREA SOUTH...WE/LL BE SOMEWHERE IN THE MIDDLE. BEST TIMING APPEARS TO BE FROM MID AFTERNOON INTO EARLY EVENING WITH PEAK HEATING. THE GRADIENT TIGHTENS AHEAD OF THE COLD FRONT ON TUESDAY AND EXPECT SOUTHERLY WINDS IN THE 20 TO 30 MPH RANGE WITH HIGHER GUSTS PERHAPS AS HIGH AS 35 MPH AT TIMES...WHICH WILL BE DEPENDENT ON THE DEPTH OF THE MIXING. WINDS RELAX TUESDAY NIGHT THEN INCREASE AGAIN ON WEDNESDAY FROM THE WEST AS DRIER AIR AND EVENTUALLY COOLER AIR SPREADS ACROSS THE REGION. WITH MOSTLY SUNNY SKIES... TEMPS SHOULD EASILY REBOUND INTO THE 60S WITH 70S POSSIBLE ACROSS THE SOUTHERN CWA BEFORE COLDER AIR ARRIVES. NORTHEAST/EASTERLY FLOW WILL KEEP THE LAKESHORE AREAS COOLER THURSDAY AND FRIDAY WITH ANOTHER STORM SYSTEM TO AFFECT THE AREA FRIDAY INTO SATURDAY. GFS ENDS PRECIP A LITTLE FASTER THAN THE ECMWF SATURDAY BUT OVERALL BOTH ARE IN FAIR AGREEMENT WITH THIS NEXT SYSTEM. CMS && .FIRE WEATHER... 516 AM MONDAY...WINDY CONDITIONS ARE EXPECTED ON TUESDAY AND WEDNESDAY. THE GRADIENT WILL TIGHTEN QUICKLY TUESDAY MORNING WITH SOUTHERLY WINDS INCREASING TO 20 TO 30 MPH BY LATE MORNING WITH HIGHER GUSTS POSSIBLE. DEWPOINTS WILL LIKELY START IN THE 20S TUESDAY MORNING AND THEN QUICKLY INCREASE THROUGH THE 40S AND EVENTUALLY INTO THE 50S LATE TUESDAY AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. BUT BEFORE THE INCREASE IN LOW LEVEL MOISTURE...AS TEMPS RISE...RELATIVE HUMIDITY LEVELS MAY DROP INTO THE 35 TO 40 PERCENT RANGE...ESPECIALLY EAST OF I-55. WINDS THEN SHIFT WESTERLY BEHIND THE COLD FRONT TUESDAY NIGHT. THERE IS STILL SOME UNCERTAINTY REGARDING HOW DEEP THE LOW LEVELS WILL MIX ON WEDNESDAY. THE DEEPER THE MIXING...THE STRONGER THE WINDS/GUSTS AND THE GREATER THE POTENTIAL TO MIX DRIER AIR ALOFT TO THE SURFACE. CURRENTLY HAVE TEMPS RANGING FROM THE MID 60S TO THE LOWER 70S. IF THESE TEMPS MATERIALIZE...COMBINED WITH THE STRONGER WINDS AND DRIER AIR...THEN CONDITIONS MAY APPROACH LOCAL RED FLAG CRITERIA...ESPECIALLY ALONG AND SOUTH OF THE I-80 CORRIDOR. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 10Z... * CIG TRENDS OVERNIGHT * NE WINDS AND GUSTS THROUGH THE MORNING * PRECIP POTENTIAL IN THE MORNING SHEA //DISCUSSION...10Z... THE MAIN LOW END MVFR CLOUDS CONTINUE TO MOVE AWAY FROM ALL OF THE TERMINALS...BUT SOME STRATOCU HAS MOVED IN FROM THE NORTHWEST WHERE SHOWER ACTIVITY IS WORKING SOUTHEAST. GUIDANCE SEEMS TO HAVE A GOOD HANDLE ON THE EXTENT OF THE PRECIP...AND WHILE IT WILL LIKELY BE A NARROW CORRIDOR THAT IS IMPACTED...IT SHOULD REMAIN WEST OF ORD. OBSERVATIONS ARE ALSO SHOWING THAT CIGS WILL REMAIN VFR IF/WHEN PRECIP OCCURS. RADAR/TIME EXTRAPOLATION BRINGS THE SHOWERS INTO RFD BY 10Z AND ACROSS ORD/MDW BY 12-13Z. THE ONE BIG POSITIVE FOR THE EASTERN TERMINALS WILL BE THE AMOUNT OF DRY AIR THAT IS INTRUDING. WHILE RADAR RETURNS WILL LOOK IMPRESSIVE...MUCH WILL FALL AS VIRGA TO START AND EVENTUALLY REACH THE GROUND FROM VFR BASES. DRY AIR WILL CONTINUE TO BLEED IN FROM THE NORTHWEST AND SHOULD SHUT OFF CHANCES FOR ORD/MDW/DPA/GYY EARLY...BUT RFD MAY LINGER A BIT LONGER. SHEA //PREVIOUS 06Z DISCUSSION... EARLY EVENING STRATUS HAS SHIFTED TO THE SOUTH AND AND WEST OF THE EASTERN TERMINALS AS OF 06Z...AND THE TREND OF CIGS RAISING AND OVERALL COVERAGE DECREASING...WILL CONTINUE. 11-3.9UM SATELLITE IMAGERY NOT SHOWING MUCH WITH REGARDS TO LOW CLOUDS ACROSS THE LAKE...WITH THE BULK OF THE LAKE STRATUS STAYING GENERALLY IN THE MKE TO RAC CORRIDOR. THERE ARE SOME HINTS THAT SOME OF THE LOWER CLOUDS MAY LINGER AROUND THE UGN/PWK AND MAYBE ORD TERMINALS THROUGH ABOUT 10Z...AND WITH THE UNCERTAINTY...WILL MAINTAIN THE TEMPO...BUT RAISE HEIGHTS. THROUGH THE REST OF THE NIGHT AND INTO THE DAY TOMORROW...WINDS WILL GRADUALLY WORK THEIR WAY AROUND THE COMPASS...GOING FROM NE TO E AND EVENTUALLY SE-SSE LATE TOMORROW NIGHT. GUSTS WILL ALSO BE ON THE DOWN TREND INTO THE MORNING HOURS...AND WILL HOLD OUT ON THE LOW 20S TO UPPER TEENS GUSTS THROUGH THE 18Z HOUR. PRECIP CHANCES WILL BE TRICKIEST FOR RFD THIS MORNING. GUIDANCE IS BRINGING SHOWERS THAT ARE CURRENTLY WEST OF LSE...SOUTHEAST AND ACROSS RFD INTO THE 12Z HOUR. RAW EXTRAPOLATION FROM RADAR IS A LITTLE CLOSER TO 11Z...BUT ONE THING THE MODELS MAY BE STRUGGLING WITH IS HOW DRY THE AIRMASS MOVING IN FROM THE NORTH ACTUALLY IS. NOT FULLY CONFIDENT THAT THE SHOWERS WILL LAST BEFORE FALLING APART...AND WILL ADD A PERIOD OF VCSH FROM 11 TO 15Z DUE TO THE UNCERTAINTY AT THIS POINT. CONFIDENCE IS FALLING WITH RESPECT TO ORD AND MDW...IF THEY WILL REMAIN DRY...THOUGH THE 03Z HRRR IS REALLY INCREASING THE SHOWERS. WILL NEED TO MONITOR AND ADJUST AS NECESSARY. SHEA //ORD AND MDW CONFIDENCE...UPDATED 10Z... * MODERATE CONFIDENCE ON CIG TRENDS * HIGH CONFIDENCE WITH WIND FORECAST * MODERATE TO LOW WITH ORD/MDW STAYING DRY THIS MORNING SHEA //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 06Z... * TUESDAY...GUSTY SOUTHERLY WINDS. A SLIGHT CHC OF TSRA FROM MID AFTN INTO THE EVE. LLWS POTENTIAL IN THE EVENING AND EARLY OVERNIGHT. * WEDNESDAY...MVFR POSSIBLE DURING THE NIGHT. * THURSDAY...VFR. * FRIDAY...CHC OF TSRA. * SATURDAY...CHC OF TSRA. SHEA && .MARINE... 255 AM CDT HIGH PRESSURE ACROSS ONTARIO WILL CONTINUE TO SLIDE EAST...ALLOWING COLD AIR TO COME RACING DOWN THE LAKE THIS MORNING. WITH THE STRONG COLD AIR ADVECTION...WINDS HAVE PICKED UP CONSIDERABLY...ALLOWING SOME COASTAL LOCATIONS TO SEE GALE FORCE GUSTS. THOSE HIGHER GUSTS SHOULD BE TEMPORARY...AND WINDS WILL GRADUALLY DIMINISH TO 15 TO 25 KT THROUGHOUT THE DAY. FLOW WILL THEN ORIENT ITSELF TO MORE EASTERLY OVERNIGHT..AND GRADUALLY BECOME SOUTHEAST TOWARDS DAWN. THE GRADIENT WILL TIGHTEN CONSIDERABLY AS LOW PRESSURE LIFTS ACROSS THE PLAINS THIS AFTERNOON...ALLOWING GALE FORCE WINDS ACROSS MUCH OF THE OPEN WATERS...AS WELL AS THE ILLINOIS NEARSHORE WATERS LATE TONIGHT. SURFACE FLOW LOOKS TO BE IN THE LOW 30 KT RANGE FOR MUCH OF THE LAKE...WITH GOOD MIXING OF HIGHER MOMENTUM AIR FROM ALOFT THROUGH AT LEAST THE AFTERNOON ON TUESDAY...WITH GUSTS POTENTIALLY PEAKING BETWEEN 35 AND 40 KT. IT IS INTO THE AFTERNOON AND EVENING HOURS THAT TEMPERATURES ALOFT BEGIN TO WARM...AND WIND GUST POTENTIAL WILL DIMINISH...BUT STILL REMAIN IN THE 25 TO 30 KT RANGE THROUGH DAWN ON WEDNESDAY. ALSO EXTENDED THE SMALL CRAFT ADVISORY FOR THE INDIANA SHORE THROUGH WEDNESDAY. CONFIDENCE IS NOT AS HIGH THAT THEY WILL REACH FULL GALE CRITERIA AS OPPOSED TO THE ILLINOIS SHORES. THE AFOREMENTIONED LOW WILL THEN CROSS NORTHERN LAKE SUPERIOR TUESDAY NIGHT...BRINGING WINDS AROUND TO THE WEST...THEN NORTHWEST AND NORTH AS ANOTHER AREA OF HIGH PRESSURE APPROACHES FROM THE WEST. WINDS WILL THEN TURN SOUTHEASTERLY INTO FRIDAY AS THE HIGH SHIFTS TO THE EAST. SHEA && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM TUESDAY. GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742- LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...4 AM TUESDAY TO 4 PM TUESDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 9 PM TUESDAY. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
530 AM MDT MON MAR 26 2012 .SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT) ISSUED AT 143 AM MDT MON MAR 26 2012 03Z WATER IMAGERY INDICATED LARGE UPPER LEVEL RIDGE IN PLACE ACROSS THE PLAINS WITH SHORT WAVE TROUGH/CLOSED LOW CIRCULATION ENTERING SOUTHERN CALIFORNIA. AT THE SFC...AREA OF LOW PRESSURE WAS IN PLACE ACROSS SOUTHEAST COLORADO IN A SIMILAR POSITION FROM 24 HOURS AGO...WITH LIGHT EASTERLY FLOW ACROSS NORTHERN HALF OF THE AREA. 00Z RAOBS INDICATED A SHARP CHANGE IN MOISTURE CONTENT FROM WEST TO EAST ACROSS THE PLAINS WITH FAIRLY LARGE INCREASES IN MOISTURE BELOW H75 NOTED AT KDDC AND KLBF FROM 24 HOURS AGO...AS EVIDENCED BY +0.3 CHANGE IN PRECIPITABLE WATER OVER THAT TIME. ASIDE FROM OVERNIGHT FOG AND VERY SMALL THUNDERSTORM CHANCES...MAIN FORECAST CONCERNS WILL BE WINDS/FIRE WX AND THUNDERSTORM CHANCES TODAY AND TONIGHT. TODAY-TONIGHT...ALTHOUGH SOME ELEVATED INSTABILITY WILL LINGER AROUND DURING THE MORNING HOURS WITH LATEST RUNS OF HRRR TRYING TO BREAK OUT SOME WEAK CONVECTION AROUND 12Z...ISENTROPIC FIELDS SUGGEST BULK OF FORCING ALONG NOSE OF LLJ WILL BE WELL TO THE NORTH AND EAST OF THE CWA AND WITH CONDENSATION DEFICITS IN EXCESS OF 130 MB...SEEMS DOUBTFUL ANY MORNING INSTABILITY WOULD BE REALIZED AND THINK BULK OF MORNING WX CONCERNS WILL CENTER AROUND ANY LINGERING FOG AROUND SUNRISE. WITH WINDS SHIFTING AROUND TO THE SOUTHWEST AND INCREASING DO NOT THINK FOG WILL BE AS WIDESPREAD OR DENSE LIKE YESTERDAY...BUT WILL MONITOR OBSERVATIONS CLOSELY AND ADJUST AS TRENDS DICTATE. BEST...ALBEIT SMALL...CHANCE FOR PRECIP WILL BE BETWEEN 21 AND 03Z AS CONVERGENCE ALONG DRYLINE REALLY BEGINS TO SHARPEN AND LOW LEVEL FRONTOGENESIS INCREASES. AREA WILL STILL BE PRETTY FAR REMOVED FROM LARGE SCALE FORCING FOR ASCENT AS UPPER TROUGH PASSES ACROSS WYOMING AND WITH STRONG CAP/CINH IN PLACE HAVE DOUBTS ABOUT CONVECTIVE INITIATION AND IF STORMS WOULD ACTUALLY SURVIVE FOR VERY LONG AS THEY MOVED AWAY FROM SFC FORCING. STILL FEEL SMALL POPS WARRANTED AND GIVEN SHEAR/INSTABILITY PROFILES THERE IS A SMALL CHANCE FOR AN ORGANIZED STORM OR TWO AS THINGS INITIATE NEAR THE KS/CO BORDER AND GRADUALLY SHIFT EAST IN THE EVENING. WITH THE RATHER SMALL PROBABILITIES FOR THUNDERSTORMS...WINDS AND FIRE WX WILL CONTINUE TO BE THE MAIN CONCERN FOR THE PERIOD AS WINDS WILL INCREASE RAPIDLY DURING THE AFTERNOON IN RESPONSE TO STRENGTHENING LOW ACROSS THE NEBRASKA PANHANDLE. WINDS SHOULD PRETTY EASILY MEET ADVISORY CONDITIONS ACROSS THE ENTIRE AREA...BUT HAVE A FEW CONCERNS THAT HIGHER GUSTS APPROACHING WARNING CRITERIA MAY OCCUR WITH THE MUCH DEEPER MIXING EXPECTED TO THE WEST OF DRYLINE. OPERATIONAL GUIDANCE NOT REALLY GIVING A SOLID CONSENSUS IN THIS REGARD AND WITH MIXED LAYER DATA GENERALLY TOPPING AT AROUND 48 KTS AND A WEAKER SFC LOW THAN LAST WEEK...THINK CONFIDENCE TOO LOW TO UPGRADE ADVISORY TO WARNING AT THIS POINT. FOR FIRE WEATHER CONDITIONS...THINK DRY LINE WILL HUG KS/CO BORDER FOR MUCH OF THE DAY AS STRONG PRESSURE FALLS OCCUR TO THE NORTHEAST. HOWEVER AS LOW BEGINS TO LIFT INTO THE NEBRASKA PANHANDLE...EXPECT DRYLINE TO START ADVANCING EASTWARD. IT WILL BE MARGINAL FROM A DURATION ASPECT...BUT FEEL UPGRADING FIRE WEATHER WATCH TO WARNING IS APPROPRIATE. TUESDAY...FRONTAL ZONE WILL STALL ACROSS SOUTHERN KANSAS DURING THE MORNING HOURS AS COOLER AIR SETTLES OVER THE AREA WITH ADVANCING SFC RIDGE. WITH A MORE STABLE AIRMASS SETTLING OVER THE AREA AND SHORT WAVE RIDGING STARTING TO DEVELOP...EXPECT DRY CONDITIONS AND GENERALLY CLEAR SKIES. ONLY SIG WEATHER CONCERN WILL BE MAGNITUDE OF DRY AIR THAT WILL BE ADVECTED INTO AREA BEHIND FRONT. ALTHOUGH AFTERNOON HUMIDITIES WILL FALL TO AROUND 15 PERCENT...POSITION OF SFC HIGH WILL LIKELY BRING LIGHT/VARIABLE WINDS TO MUCH OF THE AREA MITIGATING THE FIRE WX THREAT. COULD POSSIBLY SEE STRONGER WINDS ACROSS NEBRASKA COUNTIES...BUT THINK WITH CURRENT FIRE HIGHLIGHTS AND OVERALL LOW CONFIDENCE IN STRONGER WINDS DO NOT FEEL WATCH WARRANTED AT THIS TIME. TUESDAY NIGHT-WEDNESDAY NIGHT...SLOWLY RETREATING FRONTAL ZONE WILL LIKELY BE MAIN CONCERN FOR THE PERIOD AS NOT ONLY WILL THIS FEATURE PROVIDE A POTENTIAL FOCUS FOR THUNDERSTORM DEVELOPMENT...IT WILL ALSO BRING MUCH MORE HUMID AIR BACK TO THE CWA. GIVEN CWA WILL GENERALLY BE UNDER A FAIRLY WEAK SHORT WAVE RIDGE FOR MOST OF THE PERIOD...HAVE DOUBTS THAT FRONT WILL MAKE A RAPID NORTHERLY SURGE AND PREFER THE MORE SOUTHERLY SOLUTION GIVEN BY NAM AND LATEST ENSEMBLE MEANS. IF THERE IS A CHANCE FOR PRECIPITATION THIS PERIOD...THINK MOST LIKELY PERIOD WILL BE OVERNIGHT WEDNESDAY AS LLJ INCREASES THROUGH 06Z IN RESPONSE TO SHORT WAVE TROUGH MOVING ACROSS NORTHERN ROCKIES. NOT ONLY WILL THIS BRING A STRONG SURGE OF MOISTURE/INSTABILITY INTO AREA...BUT ISENTROPIC SURFACES SUGGEST FORCING WILL BE FOCUSED ACROSS EASTERN CWA DURING THE EVENING/OVERNIGHT HOURS. STILL A LOT OF CONCERNS ABOUT WHETHER OR NOT PARCELS WILL SATURATE AND INSTABILITY BE REALIZED...BUT THINK A SMALL THREAT FOR STORMS IS WARRANTED. IN ADDITION TO PRECIP POTENTIAL...INCREASING LOW LEVEL MOISTURE BOTH NIGHTS WILL LIKELY PROVIDE A FAVORABLE ENVIRONMENT FOR FOG FORMATION. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 1254 AM MDT MON MAR 26 2012 ZONAL FLOW WILL BE IN PLACE ACROSS THE CONUS TO START THIS PERIOD. WEAK SHORTWAVE TROUGHS WILL BE MOVING ACROSS THE CENTRAL ROCKIES AND ADJACENT PLAINS BOTH THURSDAY AND FRIDAY. APPEARS THERE WILL BE AT LEAST SOME MOISTURE AVAILABLE AND COUPLED WITH WEAK INSTABILITY WILL CARRY SLIGHT TO LOW CHANCE POPS FOR AFTERNOON/EVENING THUNDERSTORMS BOTH DAYS. UPPER RIDGE WILL BUILD ACROSS THE PLAINS FOR THE REMAINDER OF THE PERIOD AHEAD OF STRONG SYSTEM DIGGING INTO THE FOUR CORNERS. MODEL SOLUTIONS DIVERGE ON HOW TO HANDLE THAT SYSTEM VERY LATE IN THE PERIOD...SO WILL NOT CARRY ANY MENTION OF PRECIPITATION ATTM. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE ENTIRE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 523 AM MDT MON MAR 26 2012 PATCHY FOG AND SOME LINGERING LLWS WILL CONTINUE AROUND MCK THROUGH 13Z AS WEAK FRONTAL ZONE IS DRAPED ACROSS THE AREA WILL QUICKLY LIFT TO THE NORTH BRINGING PREVAILING VFR CONDITIONS AND A PROFILE LESS FAVORABLE FOR LLWS. OTHERWISE MAIN CONCERN FOR PERIOD WILL BE HOW FAST AND HOW STRONG WINDS WILL BE...MAINLY BTNW 20-01Z AT BOTH TERMINALS. WILL LIKELY SEE GUSTS GET TO AROUND 44KTS AT BOTH LOCATIONS...WITH WINDS BRIEFLY WEAKENING IN THE EVENING BEFORE STRONG COLD FRONT/WIND SHIFT COMES THROUGH AFTER 04Z. COULD STILL SEE SOME BLOWING DUST CAUSING VISBY RESTRICTIONS...ESPECIALLY AS DRYLINE MOVES THROUGH GLD BUT WITH RECENT WIDESPREAD RAINFALL DO NOT THINK PROBABILITIES ARE HIGH ENOUGH TO INCLUDE. EXPECTED COVERAGE FOR THUNDERSTORMS TODAY WILL BE VERY LOW AND DO NOT PLAN ON INCLUDING EVEN A VCTS AT THIS POINT. && .FIRE WEATHER... ISSUED AT 143 AM MDT MON MAR 26 2012 CRITICAL TO EXTREMELY CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY...MAINLY ALONG AND WEST OF THE KANSAS AND COLORADO STATE LINE AS A DRYLINE SLOWLY ADVANCES TO THE EAST TODAY. STRONG SOUTHERLY WINDS OF 25 TO 35 MPH WITH GUSTS TO AROUND 55 MPH WILL COMBINE WITH HUMIDITIES AROUND 10 PERCENT DURING THE AFTERNOON AND EARLY EVENING HOURS. A COLD FRONT WILL BEGIN TO MOVE ACROSS THE AREA TONIGHT...BRINGING A SUDDEN SHIFT IN THE WINDS AND A BRIEF PERIOD OF STRONG NORTHWESTERLY WINDS. A VERY DRY AIR MASS WILL SETTLE OVER THE AREA ON TUESDAY BRINGING HUMIDITIES DOWN TO AROUND 15 PERCENT DURING THE AFTERNOON. WHILE WINDS WILL BE LIGHT AND VARIABLE ACROSS MUCH OF THE AREA...THERE IS POTENTIAL FOR STRONGER WINDS AND CRITICAL FIRE WEATHER CONDITIONS ACROSS SOUTHWEST NEBRASKA. IF WINDS DO OCCUR...WILL LIKELY BE A MUCH SMALLER MAGNITUDE OF EVENT THAN TODAY AND CHOSE TO NOT ISSUE A FIRE WEATHER WATCH TO AVOID CONFUSION ABOUT TODAYS WARNING. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR COZ252>254. WIND ADVISORY FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR COZ090>092. KS...RED FLAG WARNING FROM NOON MDT /1 PM CDT/ TODAY TO 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ001-013-027-041. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TODAY TO 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ001>004-013>016-027>029-041-042. NE...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR NEZ079. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TODAY TO 9 PM MDT /10 PM CDT/ THIS EVENING FOR NEZ079>081. && $$ SHORT TERM...JRM LONG TERM....024 AVIATION...JRM
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1039 AM CDT MON MAR 26 2012 .DISCUSSION... UPDATED THE FORECAST TO REMOVE CHANCE OF RAIN FOR THE REST OF THE MORNING IN WESTERN IOWA. ALSO EXPANDED THE WIND ADVISORY ONE MORE TIER OF COUNTIES FURTHER EAST...INTO THE LINCOLN AND OMAHA METRO AREAS AS THESE LOCATIONS SHOULD BE JUST ON THE EDGE OF THE ADVISORY LEVEL WIND SPEEDS. DEWALD && .PREV DISCUSSION... /ISSUED 754 AM CDT MON MAR 26 2012/ DISCUSSION... HAVE INCREASED POPS ALONG AND EAST OF THE MISSOURI RIVER...AS SHOWERS FINALLY HAVE DEVELOPED IN A BAND FROM AROUND BLAIR TO PLATTSMOUTH TO NEBRASKA CITY. SO FAR...NO LIGHTNING HAS BEEN DETECTED...BUT STILL THINK A FEW STRIKES ARE POSSIBLE...AND KEPT ISOLATED WORDING IN THE GRIDS. MAYES PREV DISCUSSION... /ISSUED 646 AM CDT MON MAR 26 2012/ AVIATION... 12Z TAFS FOR KOMA...KLNK...AND KOFK. VFR CONDITIONS ARE EXPECTED AT ALL SITES THROUGH THE TAF CYCLE. SOME MID-LEVEL CIGS WILL INTERMITTENTLY AFFECT ALL SITES. SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE LATE TONIGHT...WITH KOMA THE MOST LIKELY SITE TO BE AFFECTED. CONFIDENCE IS LOW ON BOTH OCCURRENCE AND COVERAGE THOUGH...AND HAVE KEPT MENTION OUT OF THE TAF FOR NOW. WINDS WILL BE THE BIGGEST CONCERN...WITH SOUTH- SOUTHEAST WINDS GUSTING THIS AFTERNOON AND EARLY EVENING UP TO 30-35KT AT KOMA/KLNK...AND UP TO AROUND 35-40KT AT KOFK. SPEEDS WILL DIMINISH LATE TONIGHT AS A FRONT BRING A WIND SHIFT TO WESTERLY...AFFECTING KOFK EARLIEST...AND KOMA/KLNK AT THE END OF THE TAF CYCLE OR JUST OUTSIDE OF IT. MAYES PREV DISCUSSION... /ISSUED 342 AM CDT MON MAR 26 2012/ DISCUSSION... MAIN CONCERN OVER THE NEXT 30 HOURS IS THE POTENT UPPER LEVEL TROUGH CURRENTLY OVER THE GREAT BASIN. THIS IS PROGGED TO TAKE A TRACK NEWD TODAY AND MOVE THROUGH THE NORTHERN PLAINS TONIGHT AND TUE. AHEAD OF THE STRONG SYSTEM LOW LEVEL WAA IS CURRENTLY TAKING PLACE ACROSS THE REGION. MODELS SEEM TO HAVE A HIGH BIAS WITH THE MOISTURE ATTM...AND THUS A LITTLE BULLISH ON THE CONVECTIVE POTENTIAL FOR THE REST OF THE NIGHT. LATEST RUC ANALYSIS DOES INDC AROUND 500-1000 J/KG OF MUCAPE OVER THE WRN CWA...BUT POINT FORECAST SOUNDINGS INDC THIS MOISTURE IS RATHER SHALLOW AROUND 850 MB AND THERE IS A GOOD DEAL OF CIN HOLDING BACK THE CONVECTION. WE FEEL THIS TREND WILL CONT TONIGHT...BUT WILL MAINTAIN A SLIGHT CHANCE POPS B/W 12-15Z OVER THE CNTRL AND SERN CWA FOR ANYTHING ISO THAT MAY DEVELOP. OTHERWISE ANOTHER WINDY AND WARM DAY IS IN STORE FOR THE FA. WINDS AT 925 (850) MB INCREASE TO 40 (55) KT BY THIS AFTERNOON AND WITH THE INCREASING PRESSURE GRADIENT...SOME OF THIS SHOULD MAKE IT TO NEAR THE SURFACE. HIGH CLOUDS WILL LIKELY LIMIT MIXING THOUGH...AND WE WOULD FEEL BETTER WITH A DUE SOUTH OR SW WIND...SO A WIND ADVRY IS NO SLAM DUNK...BUT WITH THE PRESSURE GRADIENT AND MIXING TO 925 MB WE WILL LIKELY SEE A FEW SITES MEET CRITERIA THIS AFTN INTO THE EVNG HOURS. THUS WE HAVE ISSUED A WIND ADVISORY. THE DRY LINE STILL LOOKS TO SET UP OVER THE WRN HI PLAINS TODAY AS THE UPPER LEVEL SYSTEM MOVES TOWARD THE REGION. SOME POSITIVE CAPE IS INDICATED NEAR THE DRY LINE...BUT CIN IS SIGNIFICANT AND WITH MUCH OF THE FORCING GOING INTO SODAK...CONVECTIVE POTENTIAL FOR THE NEB AREA LOOKS PRETTY LOW...AND ESPECIALLY ANYTHING THAT WOULD WORK INTO OUR FA. THUS HAVE REDUCED POPS TO SCHC FOR THIS EVNG IN THE NW. A LITTLE BETTER CHC OF SHOWERS/STORMS MAY ACTUALLY COME AFTER MIDNIGHT IN THE ERN FA AS BETTER MOISTURE INTERACTS WITH THE ADVANCING PAC CDFNT AS IT MOVES THROUGH THE AREA. WILL CONT SOME CHC POPS IN THE E AFTER MIDNIGHT FOR THIS. THE SYSTEM SHOULD BE CLEAR OF THE FA BY TUES MRNG WITH ANOTHER WARM AND DRY DAY EXPECTED FOR TUE/WED. THE SURFACE FNT STILL LOOKS TO HANG UP OVER MO/KS ON TUE/WED AND THIS WILL START TO RETREAT NWD WED NIGHT AND INTO THE DAY ON THU (ALTHOUGH I HAVE MY DOUBTS THAT IT WILL ACTUALLY MAKE IT INTO NEB). AS THE LOW LEVEL WAA INCREASES AHEAD OF A SHRTWV PROGGED FOR THU NIGHT SOME MOISTURE WILL LIKELY WORK AROUND THE FNT AND INTO CNTRL NEB BY LATE THU WHICH SHOULD ALLOW FOR A CHANCE OF SHOWERS/STORMS LATE THU...THU NIGHT AND INTO FRI. SIGNIFICANT DIFFERENCES THEN DEVELOP BETWEEN THE GFS AND EC FOR NEXT WEEKEND AND NO CHANGES WERE MADE PAST FRI. BOUSTEAD FIRE WEATHER... IN THE POST FRONT AIRMASS ON TUES THE AIR MASS IS EXPECTED TO DRY OUT SIGNIFICANTLY. DEEP MIXING TO AROUND 850 MB OR HIGHER WILL LEAD TO DEWPOINTS FALLING THROUGH A GOOD PART OF THE DAY IN THE CNTRL AND WRN CWA. DESPITE THE FRONT MOVING THROUGH...TEMPERATURES WITH THE MIXING ON TUES WILL LIKELY CLIMB BACK INTO THE MID AND EVEN SOME UPPER 70S. THIS WILL CREATE SEVERAL HOURS OF RH BELOW 20 PERCENT DURING THE AFTN ON TUES. WITH STRONGLY UNIDIRECTIONAL FLOW AND A DECENT PRESSURE GRADIENT ON THE SOUTH SIDE OF THE SURFACE LOW OVER SD...SFC WINDS SHOULD BE SUSTAINED ABOVE 15 KT WITH GUSTS WELL OVER 25 KT. THIS ALL SHOULD COMBINED FOR A DANGEROUS FIRE WX DAY...ALTHOUGH WE ARE STARTING TO GREEN UP NICELY AROUND THE AREA...AND THUS HAVE ISSUED A FIRE WEATHER WATCH FOR TUES FOR A LARGE PART OF THE AREA. BOUSTEAD/MAYES && .OAX WATCHES/WARNINGS/ADVISORIES... NE...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR NEZ011-012-015>018-030>034-042>045-050>053- 065>067-078-088-089. WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NEZ015-033-034- 043>045-050>053-065-066-078. WIND ADVISORY UNTIL 10 PM CDT THIS EVENING FOR NEZ011-012- 016>018-030>032-042. IA...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR IAZ043-055. WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR IAZ043-055. && $$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
754 AM CDT MON MAR 26 2012 .DISCUSSION... HAVE INCREASED POPS ALONG AND EAST OF THE MISSOURI RIVER...AS SHOWERS FINALLY HAVE DEVELOPED IN A BAND FROM AROUND BLAIR TO PLATTSMOUTH TO NEBRASKA CITY. SO FAR...NO LIGHTNING HAS BEEN DETECTED...BUT STILL THINK A FEW STRIKES ARE POSSIBLE...AND KEPT ISOLATED WORDING IN THE GRIDS. MAYES && .PREV DISCUSSION... /ISSUED 646 AM CDT MON MAR 26 2012/ AVIATION... 12Z TAFS FOR KOMA...KLNK...AND KOFK. VFR CONDITIONS ARE EXPECTED AT ALL SITES THROUGH THE TAF CYCLE. SOME MID-LEVEL CIGS WILL INTERMITTENTLY AFFECT ALL SITES. SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE LATE TONIGHT...WITH KOMA THE MOST LIKELY SITE TO BE AFFECTED. CONFIDENCE IS LOW ON BOTH OCCURRENCE AND COVERAGE THOUGH...AND HAVE KEPT MENTION OUT OF THE TAF FOR NOW. WINDS WILL BE THE BIGGEST CONCERN...WITH SOUTH- SOUTHEAST WINDS GUSTING THIS AFTERNOON AND EARLY EVENING UP TO 30-35KT AT KOMA/KLNK...AND UP TO AROUND 35-40KT AT KOFK. SPEEDS WILL DIMINISH LATE TONIGHT AS A FRONT BRING A WIND SHIFT TO WESTERLY...AFFECTING KOFK EARLIEST...AND KOMA/KLNK AT THE END OF THE TAF CYCLE OR JUST OUTSIDE OF IT. MAYES PREV DISCUSSION... /ISSUED 342 AM CDT MON MAR 26 2012/ DISCUSSION... MAIN CONCERN OVER THE NEXT 30 HOURS IS THE POTENT UPPER LEVEL TROUGH CURRENTLY OVER THE GREAT BASIN. THIS IS PROGGED TO TAKE A TRACK NEWD TODAY AND MOVE THROUGH THE NORTHERN PLAINS TONIGHT AND TUE. AHEAD OF THE STRONG SYSTEM LOW LEVEL WAA IS CURRENTLY TAKING PLACE ACROSS THE REGION. MODELS SEEM TO HAVE A HIGH BIAS WITH THE MOISTURE ATTM...AND THUS A LITTLE BULLISH ON THE CONVECTIVE POTENTIAL FOR THE REST OF THE NIGHT. LATEST RUC ANALYSIS DOES INDC AROUND 500-1000 J/KG OF MUCAPE OVER THE WRN CWA...BUT POINT FORECAST SOUNDINGS INDC THIS MOISTURE IS RATHER SHALLOW AROUND 850 MB AND THERE IS A GOOD DEAL OF CIN HOLDING BACK THE CONVECTION. WE FEEL THIS TREND WILL CONT TONIGHT...BUT WILL MAINTAIN A SLIGHT CHANCE POPS B/W 12-15Z OVER THE CNTRL AND SERN CWA FOR ANYTHING ISO THAT MAY DEVELOP. OTHERWISE ANOTHER WINDY AND WARM DAY IS IN STORE FOR THE FA. WINDS AT 925 (850) MB INCREASE TO 40 (55) KT BY THIS AFTERNOON AND WITH THE INCREASING PRESSURE GRADIENT...SOME OF THIS SHOULD MAKE IT TO NEAR THE SURFACE. HIGH CLOUDS WILL LIKELY LIMIT MIXING THOUGH...AND WE WOULD FEEL BETTER WITH A DUE SOUTH OR SW WIND...SO A WIND ADVRY IS NO SLAM DUNK...BUT WITH THE PRESSURE GRADIENT AND MIXING TO 925 MB WE WILL LIKELY SEE A FEW SITES MEET CRITERIA THIS AFTN INTO THE EVNG HOURS. THUS WE HAVE ISSUED A WIND ADVISORY. THE DRY LINE STILL LOOKS TO SET UP OVER THE WRN HI PLAINS TODAY AS THE UPPER LEVEL SYSTEM MOVES TOWARD THE REGION. SOME POSITIVE CAPE IS INDICATED NEAR THE DRY LINE...BUT CIN IS SIGNIFICANT AND WITH MUCH OF THE FORCING GOING INTO SODAK...CONVECTIVE POTENTIAL FOR THE NEB AREA LOOKS PRETTY LOW...AND ESPECIALLY ANYTHING THAT WOULD WORK INTO OUR FA. THUS HAVE REDUCED POPS TO SCHC FOR THIS EVNG IN THE NW. A LITTLE BETTER CHC OF SHOWERS/STORMS MAY ACTUALLY COME AFTER MIDNIGHT IN THE ERN FA AS BETTER MOISTURE INTERACTS WITH THE ADVANCING PAC CDFNT AS IT MOVES THROUGH THE AREA. WILL CONT SOME CHC POPS IN THE E AFTER MIDNIGHT FOR THIS. THE SYSTEM SHOULD BE CLEAR OF THE FA BY TUES MRNG WITH ANOTHER WARM AND DRY DAY EXPECTED FOR TUE/WED. THE SURFACE FNT STILL LOOKS TO HANG UP OVER MO/KS ON TUE/WED AND THIS WILL START TO RETREAT NWD WED NIGHT AND INTO THE DAY ON THU (ALTHOUGH I HAVE MY DOUBTS THAT IT WILL ACTUALLY MAKE IT INTO NEB). AS THE LOW LEVEL WAA INCREASES AHEAD OF A SHRTWV PROGGED FOR THU NIGHT SOME MOISTURE WILL LIKELY WORK AROUND THE FNT AND INTO CNTRL NEB BY LATE THU WHICH SHOULD ALLOW FOR A CHANCE OF SHOWERS/STORMS LATE THU...THU NIGHT AND INTO FRI. SIGNIFICANT DIFFERENCES THEN DEVELOP BETWEEN THE GFS AND EC FOR NEXT WEEKEND AND NO CHANGES WERE MADE PAST FRI. BOUSTEAD FIRE WEATHER... IN THE POST FRONT AIRMASS ON TUES THE AIR MASS IS EXPECTED TO DRY OUT SIGNIFICANTLY. DEEP MIXING TO AROUND 850 MB OR HIGHER WILL LEAD TO DEWPOINTS FALLING THROUGH A GOOD PART OF THE DAY IN THE CNTRL AND WRN CWA. DESPITE THE FRONT MOVING THROUGH...TEMPERATURES WITH THE MIXING ON TUES WILL LIKELY CLIMB BACK INTO THE MID AND EVEN SOME UPPER 70S. THIS WILL CREATE SEVERAL HOURS OF RH BELOW 20 PERCENT DURING THE AFTN ON TUES. WITH STRONGLY UNIDIRECTIONAL FLOW AND A DECENT PRESSURE GRADIENT ON THE SOUTH SIDE OF THE SURFACE LOW OVER SD...SFC WINDS SHOULD BE SUSTAINED ABOVE 15 KT WITH GUSTS WELL OVER 25 KT. THIS ALL SHOULD COMBINED FOR A DANGEROUS FIRE WX DAY...ALTHOUGH WE ARE STARTING TO GREEN UP NICELY AROUND THE AREA...AND THUS HAVE ISSUED A FIRE WEATHER WATCH FOR TUES FOR A LARGE PART OF THE AREA. BOUSTEAD/MAYES && .OAX WATCHES/WARNINGS/ADVISORIES... NE...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR NEZ011-012-015>018-030>034-042>045-050>053- 065>067-078-088-089. WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING FOR NEZ015-033-043-044-050-051-065-078. WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 10 PM CDT THIS EVENING FOR NEZ011-012-016>018-030>032-042. IA...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR IAZ043-055. && $$ 99/99
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
646 AM CDT MON MAR 26 2012 .AVIATION... 12Z TAFS FOR KOMA...KLNK...AND KOFK. VFR CONDITIONS ARE EXPECTED AT ALL SITES THROUGH THE TAF CYCLE. SOME MID-LEVEL CIGS WILL INTERMITTENTLY AFFECT ALL SITES. SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE LATE TONIGHT...WITH KOMA THE MOST LIKELY SITE TO BE AFFECTED. CONFIDENCE IS LOW ON BOTH OCCURRENCE AND COVERAGE THOUGH...AND HAVE KEPT MENTION OUT OF THE TAF FOR NOW. WINDS WILL BE THE BIGGEST CONCERN...WITH SOUTH- SOUTHEAST WINDS GUSTING THIS AFTERNOON AND EARLY EVENING UP TO 30-35KT AT KOMA/KLNK...AND UP TO AROUND 35-40KT AT KOFK. SPEEDS WILL DIMINISH LATE TONIGHT AS A FRONT BRING A WIND SHIFT TO WESTERLY...AFFECTING KOFK EARLIEST...AND KOMA/KLNK AT THE END OF THE TAF CYCLE OR JUST OUTSIDE OF IT. MAYES && .PREV DISCUSSION... /ISSUED 342 AM CDT MON MAR 26 2012/ DISCUSSION... MAIN CONCERN OVER THE NEXT 30 HOURS IS THE POTENT UPPER LEVEL TROUGH CURRENTLY OVER THE GREAT BASIN. THIS IS PROGGED TO TAKE A TRACK NEWD TODAY AND MOVE THROUGH THE NORTHERN PLAINS TONIGHT AND TUE. AHEAD OF THE STRONG SYSTEM LOW LEVEL WAA IS CURRENTLY TAKING PLACE ACROSS THE REGION. MODELS SEEM TO HAVE A HIGH BIAS WITH THE MOISTURE ATTM...AND THUS A LITTLE BULLISH ON THE CONVECTIVE POTENTIAL FOR THE REST OF THE NIGHT. LATEST RUC ANALYSIS DOES INDC AROUND 500-1000 J/KG OF MUCAPE OVER THE WRN CWA...BUT POINT FORECAST SOUNDINGS INDC THIS MOISTURE IS RATHER SHALLOW AROUND 850 MB AND THERE IS A GOOD DEAL OF CIN HOLDING BACK THE CONVECTION. WE FEEL THIS TREND WILL CONT TONIGHT...BUT WILL MAINTAIN A SLIGHT CHANCE POPS B/W 12-15Z OVER THE CNTRL AND SERN CWA FOR ANYTHING ISO THAT MAY DEVELOP. OTHERWISE ANOTHER WINDY AND WARM DAY IS IN STORE FOR THE FA. WINDS AT 925 (850) MB INCREASE TO 40 (55) KT BY THIS AFTERNOON AND WITH THE INCREASING PRESSURE GRADIENT...SOME OF THIS SHOULD MAKE IT TO NEAR THE SURFACE. HIGH CLOUDS WILL LIKELY LIMIT MIXING THOUGH...AND WE WOULD FEEL BETTER WITH A DUE SOUTH OR SW WIND...SO A WIND ADVRY IS NO SLAM DUNK...BUT WITH THE PRESSURE GRADIENT AND MIXING TO 925 MB WE WILL LIKELY SEE A FEW SITES MEET CRITERIA THIS AFTN INTO THE EVNG HOURS. THUS WE HAVE ISSUED A WIND ADVISORY. THE DRY LINE STILL LOOKS TO SET UP OVER THE WRN HI PLAINS TODAY AS THE UPPER LEVEL SYSTEM MOVES TOWARD THE REGION. SOME POSITIVE CAPE IS INDICATED NEAR THE DRY LINE...BUT CIN IS SIGNIFICANT AND WITH MUCH OF THE FORCING GOING INTO SODAK...CONVECTIVE POTENTIAL FOR THE NEB AREA LOOKS PRETTY LOW...AND ESPECIALLY ANYTHING THAT WOULD WORK INTO OUR FA. THUS HAVE REDUCED POPS TO SCHC FOR THIS EVNG IN THE NW. A LITTLE BETTER CHC OF SHOWERS/STORMS MAY ACTUALLY COME AFTER MIDNIGHT IN THE ERN FA AS BETTER MOISTURE INTERACTS WITH THE ADVANCING PAC CDFNT AS IT MOVES THROUGH THE AREA. WILL CONT SOME CHC POPS IN THE E AFTER MIDNIGHT FOR THIS. THE SYSTEM SHOULD BE CLEAR OF THE FA BY TUES MRNG WITH ANOTHER WARM AND DRY DAY EXPECTED FOR TUE/WED. THE SURFACE FNT STILL LOOKS TO HANG UP OVER MO/KS ON TUE/WED AND THIS WILL START TO RETREAT NWD WED NIGHT AND INTO THE DAY ON THU (ALTHOUGH I HAVE MY DOUBTS THAT IT WILL ACTUALLY MAKE IT INTO NEB). AS THE LOW LEVEL WAA INCREASES AHEAD OF A SHRTWV PROGGED FOR THU NIGHT SOME MOISTURE WILL LIKELY WORK AROUND THE FNT AND INTO CNTRL NEB BY LATE THU WHICH SHOULD ALLOW FOR A CHANCE OF SHOWERS/STORMS LATE THU...THU NIGHT AND INTO FRI. SIGNIFICANT DIFFERENCES THEN DEVELOP BETWEEN THE GFS AND EC FOR NEXT WEEKEND AND NO CHANGES WERE MADE PAST FRI. BOUSTEAD FIRE WEATHER... IN THE POST FRONT AIRMASS ON TUES THE AIR MASS IS EXPECTED TO DRY OUT SIGNIFICANTLY. DEEP MIXING TO AROUND 850 MB OR HIGHER WILL LEAD TO DEWPOINTS FALLING THROUGH A GOOD PART OF THE DAY IN THE CNTRL AND WRN CWA. DESPITE THE FRONT MOVING THROUGH...TEMPERATURES WITH THE MIXING ON TUES WILL LIKELY CLIMB BACK INTO THE MID AND EVEN SOME UPPER 70S. THIS WILL CREATE SEVERAL HOURS OF RH BELOW 20 PERCENT DURING THE AFTN ON TUES. WITH STRONGLY UNIDIRECTIONAL FLOW AND A DECENT PRESSURE GRADIENT ON THE SOUTH SIDE OF THE SURFACE LOW OVER SD...SFC WINDS SHOULD BE SUSTAINED ABOVE 15 KT WITH GUSTS WELL OVER 25 KT. THIS ALL SHOULD COMBINED FOR A DANGEROUS FIRE WX DAY...ALTHOUGH WE ARE STARTING TO GREEN UP NICELY AROUND THE AREA...AND THUS HAVE ISSUED A FIRE WEATHER WATCH FOR TUES FOR A LARGE PART OF THE AREA. BOUSTEAD/MAYES && .OAX WATCHES/WARNINGS/ADVISORIES... NE...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR NEZ011-012-015>018-030>034-042>045-050>053- 065>067-078-088-089. WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING FOR NEZ015-033-043-044-050-051-065-078. WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 10 PM CDT THIS EVENING FOR NEZ011-012-016>018-030>032-042. IA...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR IAZ043-055. && $$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
629 AM EDT MON MAR 26 2012 .SYNOPSIS... DRIER AND COOLER CONDITIONS WILL SETTLE IN TODAY AND TUESDAY AS HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES. A BRIEF WARMING TREND WILL ENSUE DURING THE MIDDLE OF THIS WEEK...FOLLOWED BY A COLD FRONT ON THURSDAY. NEAR SEASONABLE WEATHER THEN EXPECTED INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM MONDAY...BKN-OVC LOW CLOUDS BLANKET THE AREA THIS MORNING...BUT THIS IS ONLY TEMPORARY AS DRIER AIR LURKING JUST WEST OF THE AREA PLUS CONTINUING ISENTROPIC DOWNGLIDE SHOULD ERODE MOST IF NOT ALL OF THE CLOUD COVER WITHIN THE NEXT 2-4 HOURS. NO SIGNIFICANT CHANGES WERE MADE FROM THE PREVIOUS FORECAST. DISCUSSION FROM 3 AM FOLLOWS... THE COLD UPPER LOW IS NOW WELL EAST OF CAPE HATTERAS AND MOVING OUT TO SEA. OUR MID-LEVEL TEMPERATURES HAVE WARMED CONSIDERABLY SINCE THE DEPARTURE OF THE LOW AND A MUCH DRIER AND MORE STABLE ATMOSPHERE IS EXPECTED TODAY INTO TONIGHT. SURFACE HIGH PRESSURE JUST NORTH OF THE GREAT LAKES WILL PUSH A SECONDARY COLD FRONT SOUTH AND THROUGH THE EASTERN CAROLINAS LATE THIS AFTERNOON. ALTHOUGH THERE SHOULDN`T BE ANY CLOUDS WITH THIS FEATURE...NORTH-NORTHEAST WINDS TONIGHT WILL BRING A MUCH COOLER AIRMASS INTO THE REGION THAN WE HAVE SEEN IN NEARLY TWO WEEKS. RESIDUAL LOW CLOUDS THIS MORNING SWIRLING AROUND THE BACKSIDE OF THE UPPER LOW EXTEND ACROSS THE EASTERN HALF OF NORTH CAROLINA. ISENTROPIC ANALYSIS REVEALS SINKING PARCEL TRAJECTORIES WHICH SHOULD GRADUALLY ERODE THESE CLOUDS FROM WEST TO EAST THROUGH THE EARLY MORNING HOURS. AFTER 14Z (10 AM) SUNSHINE SHOULD BE BREAKING OUT EVEN IN THE WILMINGTON AREA...WITH SUNNY SKIES EXPECTED EVERYWHERE DURING THE LATE MORNING AND AFTERNOON. HIGHS SHOULD REACH THE 75-80 TODAY... WARMEST IN THE SOUTH CAROLINA PEE DEE REGION AND COOLEST ALONG THE NC EAST-FACING BEACHES. LOWS TONIGHT SHOULD FALL TO 43-48...COOLEST IN INTERIOR SOUTHEAST NORTH CAROLINA AND WARMEST NEAR THE SANTEE RIVER. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...GUIDANCE CONTINUES TO INDICATE THAT TUESDAY WILL BE THE FIRST BELOW CLIMO DAY SINCE MARCH 11 AS A WEDGE OF HIGH PRESSURE BUILDS AGAINST THE APPALACHIAN RANGE. ALTHOUGH MODELS HAVE BACKED OFF ON STRENGTH OF THE WEDGE...NE FLOW AT THE SURFACE WILL KEEP TEMPS BELOW...TO WELL BELOW...SEASONABLE NORMS...WITH THE COOLEST READINGS BEING IN THE CAPE FEAR REGION WHERE NE WINDS ADVECT OFF THE COOL OCEAN. ALTHOUGH SOUNDINGS ARE QUITE DRY TUESDAY...NOTE THAT FREQUENTLY MOISTURE IS UNDER-MODELED IN WEDGE SCENARIOS SO WILL INCREASE CLOUD COVER MORE THAN SUGGESTED BY PROFILES. MIXING WILL LIKELY ONLY REACH TO BELOW 900MB...AND LOW LEVEL 1000-900MB THICKNESSES SUPPORT TEMPS ONLY IN THE LOWER 60S NEAR WILMINGTON...TO AROUND 70 ACROSS THE PEE DEE REGION OF SC. HIGH DRIFTS OVERHEAD TUESDAY NIGHT ALLOWING FOR DECOUPLING IN THE LOWER ATMOSPHERE...AND CLEAR SKY CONDITIONS WILL ALLOW FOR DECENT RADIATIONAL COOLING. THE FLY-IN-THE-OINTMENT...AS IT IS...IS WHETHER SOME SLIGHT LOW LEVEL WAA BEGINS OVERNIGHT AS HIGH DRIFTS OFFSHORE...OR WHETHER WE CAN STAY PERFECTLY CALM. NEARLY ALL THE FORECAST PROFILES SUGGEST WARMING IN THE LOW LEVELS FROM 06Z-12Z WEDNESDAY AS LIGHT SOUTHERLY FLOW DEVELOPS AROUND DEPARTING HIGH PRESSURE. BELIEVE IT WILL BE TOUGH FOR SUCH SIGNIFICANT WARMING AFTER MANY HOURS OF NOCTURNAL INVERSION DEVELOPMENT...BUT WILL NOT DROP MINS AS LOW AS MAV NUMBERS...AND OPT FOR LOW 40S AREA WIDE...WITH THE COLDEST SPOTS POTENTIALLY TOUCHING 39. BY WEDNESDAY THE HIGH HAS DRIFTED OFFSHORE AND WARM SOUTHERLY RETURN FLOW COMES BACK INTO THE CAROLINAS. MOSTLY SUNNY SKY CONDITIONS WILL HELP RAISE TEMPS BACK TO ABOVE CLIMO...MID 70S AWAY FROM THE COAST...AND CONTINUED SOUTHERLY FLOW AT NIGHT WILL KEEPS TEMPS FROM FALLING MUCH OUT OF THE MID 50S AT NIGHT. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 300 AM MONDAY...MOST INTERESTING PART OF THE LONG TERM OCCURS LATE THURSDAY WITH A COLD FRONTAL PASSAGE...BEFORE COOL HIGH PRESSURE SETTLES IN TO THE WEEKEND. MODERATELY POTENT S/W TROUGH DIGS FROM THE GREAT LAKES THROUGH NEW ENGLAND THURSDAY...SUPPRESSING THE UPPER RIDGE AND DRIVING A COLD FRONT THROUGH THE CAROLINAS. STILL NOTING TIMING DIFFERENCES IN THE GUIDANCE...BUT FOR PERSISTENCE WILL CONTINUE TO FAVOR THE SLIGHTLY SLOWER ECMWF/CMC OVER THE GFS. NOT MUCH IN THE WAY OF MOISTURE RETURN AHEAD OF THIS...ALTHOUGH MID LEVEL THETA-E RIDGE DOES TRY TO ADVECT INTO OUR AREA JUST AHEAD OF FROPA...SO WILL CARRY SCHC POP FOR SHOWERS THURSDAY EVE/NIGHT. IF THE SLOWER SOLUTION COMES TRUE...850MB TEMPS RISE TO 11C WHICH SUPPORTS TEMPS AT OR ABOVE 80 MOST AREAS AWAY FROM THE BEACHES...AND THURSDAY WILL BE THE WARMEST DAY OF THE EXTENDED. IF...HOWEVER...A FASTER FROPA OCCURS...THIS WILL OBVIOUSLY CUT TEMPS BACK ESPECIALLY ACROSS THE NORTH...AND WOULD INCREASE THE LIKELIHOOD OF AFTN SHOWERS ALONG THE BOUNDARY. FOR NOW WILL STICK WITH THE SLOWER SOLUTION. COOL HIGH PRESSURE BUILDS ACROSS THE REGION FRI/SAT RETURNING THE AREA TO NEAR CLIMO TEMPS...POSSIBLY BELOW CLIMO WITH SOME NE FLOW ON FRIDAY. GFS/ECMWF THEN DIVERGE CONSIDERABLY ON EVOLUTION AND STRENGTH OF ANOTHER NORTHERN STREAM S/W DROPPING ACROSS THE MIDWEST RIDGE. GFS IS FASTER AND WEAKER...CONTINUING ITS TREND THIS YEAR...SO WILL BLEND ECMWF/GFS BUT WITH ADDITIONAL WEIGHT ON THE FORMER. THIS WILL BRING INCREASED CHANCES FOR RAIN THROUGH THE WKND AS LOW PRESSURE DEVELOPS NEAR THE OHIO VALLEY. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... AS OF 06Z...ALTHOUGH SHOWERS HAVE ENDED ACROSS SOUTH CAROLINA... RADAR AND THE LATEST HRRR MODEL SUGGEST IT`S NOT OVER FOR NORTH CAROLINA JUST YET. SHOWERS ROTATING SOUTHWARD ON THE BACK SIDE OF THE DEPARTING UPPER LEVEL LOW PRESSURE AREA WILL AFFECT THE ILM TERMINAL THROUGH 09Z...WITH EVEN A FEW LIGHT SHOWERS POSSIBLE IN THE LBT VICINITY THROUGH 0730Z OR SO. THERE IS SOME UNCERTAINTY WITH REGARDS TO CEILING HEIGHTS...MVFR SHOULD PREDOMINATE...BUT IFR IS NOT OUT OF THE QUESTION PARTICULARLY AFTER 08Z. AFTER DAYBREAK WINDS WILL PICK UP...GUSTING OVER 20 KTS BY MID MORNING. SKIES WILL BECOME NEARLY CLEAR AS THE UPPER LOW EXITS OFFSHORE. EXTENDED OUTLOOK...VFR MONDAY NIGHT THROUGH WEDNESDAY. POSSIBLE MORNING FOG THURSDAY AND FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM MONDAY...NORTH WINDS 15-20 KT HAVE DEVELOPED ACROSS THE COASTAL WATERS AS FORECAST. WE SHOULD BE IN THE 3-4 HOUR PERIOD OF STRONGEST WINDS CURRENTLY...WITH DIMINISHING WINDS LATE THIS MORNING INTO THE EARLY AFTERNOON HOURS. PREVIOUS DISCUSSION FROM 3 AM FOLLOWS... LOW PRESSURE HAS MOVED EAST OF THE NC OUTER BANKS AND WILL MOVE FARTHER OUT TO SEA TODAY. ATTENTION WILL TURN TO HIGH PRESSURE IN CANADA JUST NORTH OF THE GREAT LAKES THAT WILL BUILD SOUTH TOWARD THE CAROLINAS. AS THIS HIGH MOVES SOUTH IT WILL PUSH A DRY COLD FRONT THROUGH THE AREA LATE THIS AFTERNOON. NORTH- NORTHEAST WINDS WILL INCREASE BEHIND THIS FRONT...REACHING 15-20 KT BY LATE THIS EVENING AND CONTINUING OVERNIGHT. THERE IS SOME POTENTIAL SEAS COULD REACH 6 FEET IN THE WATERS NEAR FRYING PAN SHOALS DUE TO THEIR EXPOSED POSITION IN THIS WIND DIRECTION...BUT CONFIDENCE IS TOO LOW TO RAISE AN ADVISORY AT THIS TIME. ELSEWHERE SEAS 2-4 FEET TODAY SHOULD BUILD TO 3-5 FT TONIGHT AWAY FROM SHORE WITH THE INCREASED WIND SPEEDS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...NE SURGE ONGOING AT THE START OF THE PERIOD AROUND WEDGE OF HIGH PRESSURE. AT LEAST CAUTIONARY HEADLINES APPEAR LIKELY TO BE IN EFFECT TUESDAY MORNING WITH 15-20 KT WINDS CREATING 4-5 FT NE WIND WAVES CONTROLLING THE WAVE SPECTRUM. DURING TUESDAY...HIGH PRESSURE DRIFTS OVER THE WATERS SO WINDS/WAVES RAPIDLY DECREASE THROUGH THE DAY...WINDS BECOMING NEARLY CALM OVERNIGHT WHILE SEAS FALL TO 1-2 FT. GRADIENT INCREASES WEDNESDAY AS HIGH PRESSURE DRIFTS OFFSHORE AND A COLD FRONT APPROACHES FROM THE NW. THIS PUTS THE WATERS INTO A PRE FRONTAL REGIME...WITH SW WINDS INCREASING TO 15-20 KTS FORCING SEAS BACK UP TO 3-5 FT...AND CAUTIONARY HEADLINES MAY ONCE AGAIN BE NECESSARY. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 300 AM MONDAY...CAUTIONARY HEADLINES POSSIBLY ONGOING AT THE START OF THE PERIOD AS A COLD FRONT APPROACHES FROM THE NORTHWEST. SW WINDS OF 15-20 KTS WILL VEER AND WEAKEN THROUGH THE DAY...BECOMING NORTH AROUND 10 KTS THURSDAY NIGHT. SW WIND WAVES OF 3-5 FT EARLY THURSDAY FALL TO 2-3 FT BY FRIDAY MORNING. A PERIOD OF CONFUSED SEAS IS LIKELY THURSDAY EVE AS THE WAVE SPECTRUM FEATURES TWO DOMINANT WIND WAVES...ONE SLOWLY WEAKENING FROM THE SW...WHILE A BUILDING NE WIND WAVE DEVELOPS. N/NE WINDS LESS THAN 10 KTS FRIDAY KEEP SEAS ONLY AROUND 2 FT THROUGH THE DAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JDW NEAR TERM...TRA SHORT TERM...JDW LONG TERM...JDW AVIATION...TRA/DL
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
645 AM CDT MON MAR 26 2012 .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT 325 AM CDT MON MAR 26 2012 THE MAIN FOCUS GOING THROUGH MID WEEK IS WITH THE PRECIPITATION CHANCES TODAY INTO TOMORROW AND WHETHER ANY SEVERE THUNDERSTORMS WILL BE POSSIBLE TUESDAY AFTERNOON. CURRENTLY...A BAND OF SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS HAS DEVELOPED ACROSS SOUTHERN MINNESOTA INTO NORTHEAST IOWA AND SOUTHWEST WISCONSIN AS A RESULT OF THE COMBINATION OF A FRONTOGENETIC CIRCULATION BETWEEN 850-500MB AND THE EASTERN WING OF INCREASING 925-850MB MOISTURE TRANSPORT. THIS CONVECTION IS REACHING THE GROUND DESPITE A DRY LOW LEVEL AIR MASS THAT FEATURES A DEW POINT DEPRESSION OF ABOUT 35C AT 830MB PER THE 26.00Z MPX SOUNDING. THE QUESTION FOR THIS MORNING IS WITH HOW LONG THE CONVECTION WILL HOLD ON FOR. THE 26.00Z NAM CROSS SECTIONS SHOW THIS FRONTOGENETIC CIRCULATION DRIFTING NORTH AND STAYING STRONG THROUGHOUT THE MORNING AND EARLY AFTERNOON BEFORE WEAKENING THIS AFTERNOON. WITH 26.05Z AND PREVIOUS HRRR RUNS SHOWING THIS PRECIPITATION HOLDING ON INTO THE MORNING...HAVE KEPT SOME DECENT CHANCES FOR SHOWERS/ISOLATED THUNDER GOING INTO THE AFTERNOON. ALSO...SKIES REMAINED MOSTLY CLEAR OVERNIGHT ACROSS NORTHERN WISCONSIN AND ALLOWED FOR TEMPERATURES TO DROP BELOW FREEZING AT MEDFORD. THEREFORE...WILL KEEP THE FREEZE WARNING GOING UNTIL 8AM FOR TAYLOR COUNTY. JUST AS THIS FIRST BAND OF FORCING WEAKENS THIS AFTERNOON...925-850MB MOISTURE TRANSPORT AND ISENTROPIC LIFT ON THE 300-310K SURFACES WILL BE ON THE INCREASE ACROSS SOUTHERN MINNESOTA AND NORTH CENTRAL IOWA. THIS WILL LEAD TO A BAND OF CONVECTION REDEVELOPING ACROSS THIS AREA WHILE LIFTING TO THE NORTHEAST THROUGH THE LATE AFTERNOON AND EVENING HOURS. WITH THIS 925-850MB MOISTURE TRANSPORT NOSE SHIFTING NORTHEAST AND STRENGTHENING THROUGH THE EVENING AND OVERNIGHT HOURS...CHANCES STILL LOOK FAIRLY GOOD FOR THIS CONVECTION HOLDING ON THROUGH THE NIGHT...PARTICULARLY ACROSS SOUTHEAST MINNESOTA AND WESTERN WISCONSIN. A FEW HUNDRED J/KG OF MID LEVEL INSTABILITY FEEDING INTO THESE SHOWERS SHOULD LEAD TO SOME THUNDER OCCURRING...BUT NOTHING VIGOROUS ENOUGH TO GET ORGANIZED AND POSE A SEVERE THREAT. AS THIS FEATURE LIFTS OFF TO THE NORTH...THE MAIN CHANNEL OF LOW LEVEL MOISTURE TRANSPORT WILL MOVE ACROSS THE REGION TUESDAY MORNING AHEAD OF THE COLD FRONT OR POSSIBLY A PRE-FRONTAL TROUGH. AS THIS MOISTURE FEED SHIFTS EAST TUESDAY AFTERNOON...THE MAIN COLD FRONT WILL TRACK EAST AS WELL AND GET TO THE MISSISSIPPI RIVER BY MID AFTERNOON. THE 26.00Z NAM CONTINUES TO SHOW SOME 0-3KM MUCAPE OF 500-1500 J/KG DEVELOPING AHEAD OF THIS FRONT IN THE AFTERNOON...BUT DOES NOT SHOW MUCH IN THE WAY OF QPF ACROSS SOUTHWEST WISCONSIN. IT DOES CONVECT FURTHER SOUTH IN EASTERN IOWA WHERE THIS INSTABILITY CROSSES THE LOW LEVEL MOISTURE TRANSPORT. DESPITE 0-3KM WIND SHEAR BEING VERY FAVORABLE AT 40KTS...THE PROSPECTS FOR ORGANIZED CONVECTION STILL APPEAR TO BE FAIRLY LOW ACROSS SOUTHWEST WISCONSIN. IF THE COLD FRONT CAN PROVIDE ENOUGH OF A KICKER...A FEW STORMS MAY BE ABLE TO FORM THOUGH THE WINDOW LOOKS VERY SMALL IN THE LATE AFTERNOON. AFTER THE FRONT MOVES THROUGH...A COOLER AND VERY DRY AIR MASS ADVECTS INTO THE REGION WITH 850MB TEMPERATURES DROPPING FROM +10C TUESDAY AFTERNOON TO AROUND -2C BY WEDNESDAY MORNING. WITH THIS COLDER...YET SEASONAL...AIR MASS IN PLACE...LOW TEMPERATURES WEDNESDAY NIGHT WILL BE CLOSE TO FREEZING IN WESTERN WISCONSIN. HAVE NOT PUT ANY FROST IN THE FORECAST YET SINCE WINDS APPEAR TO STAY STRONG ENOUGH TO KEEP ANY FROM FORMING. .LONG TERM...THURSDAY THROUGH SUNDAY NIGHT 325 AM CDT MON MAR 26 2012 EXTENDED GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH FRIDAY BEFORE THE 26.00Z GFS AND ECMWF GET OUT OF PHASE WITH EACH OTHER. A RIDGE OF HIGH PRESSURE WILL MOVE THROUGH THE REGION ON THURSDAY BEFORE A MID LEVEL SHORTWAVE TROUGH SWINGS ACROSS THE NORTHERN PLAINS THURSDAY NIGHT. THIS WILL BRING SOUTHERLY RETURN FLOW UP INTO THE UPPER MISSISSIPPI RIVER VALLEY AHEAD OF THIS TROUGH AND BRING THE NEXT ROUND OF SHOWERS/STORMS ON IN. SOME DISCREPANCIES START SHOWING UP ON FRIDAY AS THE 26.00Z GFS HOLDS ONTO THE PRECIPITATION LONGER THAN THE 26.00Z ECMWF. THE 26.00Z ECMWF/GEM BOTH BRING A MORE POTENT LOW THROUGH ON FRIDAY/SATURDAY THAN WHAT THE 26.00Z GFS HAS. BEYOND THIS...THE GFS HOLDS UP THE TROUGH OUT WEST WHILE THE ECMWF IS MUCH MORE PROGRESSIVE. FOR NOW...HAVE CONTINUED THE TREND OF GOING WITH A CONSENSUS BLEND OF EACH RATHER THAN TO GRAB ONTO ONE EXTREME OR THE OTHER WITH THE GFS BEING THE WARM EXTREME AND THE ECMWF BEING THE COLD EXTREME. && .AVIATION...TODAY INTO TUESDAY 645 AM CDT MON MAR 26 2012 MOISTURE TRANSPORT/LIFT IN THE 850-700MB LAYER WILL CONTINUE TO PRODUCE SCT -SHRA AND ISOLATED -TSRA ACROSS THE AREA THIS MORNING. WITH THE FORCING ELEVATED AND A DRIER LOWER LEVEL EASTERLY FLOW OVER THE AREA...CIGS/VSBYS LOOKING TO REMAIN VFR WITH MOST IF NOT ALL OF THE -SHRA. WITH ANY -TSRA ISOLATED...ONLY INCLUDED A CB MENTION FOR THE LATER MORNING HOURS. MOISTURE TRANSPORT/LIFT WEAKENS FOR THE AFTERNOON WITH A LULL IN THE -SHRA...THEN INCREASES AGAIN FOR TONIGHT. WITH THE PERSISTENT AND INCREASING EAST/SOUTHEAST SFC-850MB FLOW...CIGS/VSBYS WITH ANY -SHRA/ISOLATED -TSRA TONIGHT AGAIN LOOK TO REMAIN VFR. WITH SCT COVERAGE AND THE -SHRA LOOKING TO BE LIGHT ONLY INCLUDED VCSH IN TAFS FOR TONIGHT. TIGHT PRESSURE GRADIENT OVER THE AREA TODAY/TONIGHT WILL RESULT IN BRISK EAST/ SOUTHEAST WINDS THRU THE PERIOD...ESPECIALLY AT THE HIGHER/OPEN TERRAIN SITES LIKE KRST. A COLD FRONT WILL SWEEP ACROSS THE AREA TUE...SWINGING THE WINDS TO THE SOUTHWEST. SUBSIDENCE AND TIGHT GRADIENT BEHIND THE FRONT WILL RESULT IN SOUTHWEST WINDS 20-25KT G35KT MUCH OF TUE... AGAIN MAINLY AT THE HIGHER/OPEN TERRAIN SITES LIKE KRST. && .ARX WATCHES/WARNINGS/ADVISORIES... 325 AM CDT MON MAR 26 2012 WI...FREEZE WARNING UNTIL 8 AM CDT MONDAY FOR WIZ017. MN...NONE. IA...NONE. && $$ SHORT TERM...HALBACH LONG TERM....HALBACH AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
612 PM EDT MON MAR 26 2012 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION LATE TONIGHT AND EARLY THURSDAY...THEN HIGH PRESSURE WILL BUILD SOUTH AND SHIFT INTO THE MID ATLANTIC THROUGH WEDNESDAY. ANOTHER COLD FRONT WILL MOVE THROUGH THURSDAY...FOLLOWED BY ANOTHER AREA OF HIGH PRESSURE BUILDING TO THE NORTH FRIDAY. AN AREA OF UNSETTLED WEATHER WILL APPROACH FROM THE WEST FOR THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... NO MAJOR CHANGES WERE MADE TO THE FORECAST FOR THE EARLY EVENING UPDATE. EXPECT A CLEAR AND TRANQUIL EVENING. A COLD FRONT WILL ADVANCE THROUGH NORTHERN COUNTIES AFTER MIDNIGHT...AND NE WINDS WILL SURGE PERHAPS RESULTING IN SOME UNEVEN TEMPERATURE TRENDS. THE FRONT COULD BE ACCOMPANIED BY A FEW CLOUDS BUT MODEL SOUNDINGS SUGGEST THAT MOSTLY CLEAR FORECASTS ARE REASONABLE. TEMPERATURES WILL BOTTOM OUT IN THE LOWER TO MID 50S AT MOST LOCATIONS. A FEW OF THE COOLEST INLAND LOCATIONS COULD DIP INTO THE UPPER 40S BRIEFLY AROUND DAYBREAK. AT THE COAST...TEMPERATURES COULD FALL INTO THE UPPER 50S/AROUND 60F THIS EVENING...THEN TEMPERATURES COULD ACTUALLY RISE A FEW DEGREES AS AN ONSHORE WIND DEVELOPS LATE. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... TUESDAY...THE DRY COLD FRONT WILL CONTINUE TO PRESS SOUTHWARD TUESDAY MORNING INTO TUESDAY AFTERNOON...RESULTING IN NOTICEABLY COOLER HIGH TEMPERATURES COMPARED TO PREVIOUS DAYS. MODERATE NORTHEAST FLOW BEHIND THE DESCENDING FRONT WILL CREATE A DECENT NORTH/SOUTH TEMPERATURE GRADIENT. EXPECT AFTERNOON TEMPERATURES TO BE SUPPRESSED AROUND 70 DEGREES ACROSS THE NORTHERN FORECAST AREA...WHILE RISING INTO THE UPPER 70S NEAR THE ALTAMAHA RIVER IN SOUTHEAST GEORGIA. SURFACE HIGH PRESSURE WILL SETTLE INTO THE MID ATLANTIC AND SOUTHEAST STATES IN THE WAKE OF THE FRONT BY TUESDAY NIGHT. THE RESULTING WEAK PRESSURE GRADIENT AND LIGHT WINDS WILL ENHANCE RADIATIONAL COOLING UNDER MOSTLY CLEAR SKIES...SUPPORTING MORE SEASONAL LOW TEMPERATURES RANGING FROM THE UPPER 40S NORTH TO THE LOWER 50S SOUTHEAST GEORGIA. WEDNESDAY...SURFACE HIGH PRESSURE WILL CONTINUE TO DESCEND SOUTHWARD AND SLIP OFF THE COAST INTO THE ATLANTIC WATERS ON WEDNESDAY. EXPECT A MORE SOUTHERLY FLOW TO DEVELOP BY THE AFTERNOON HOURS...AND UNDER MOSTLY SUNNY TO PARTLY CLOUDY SKIES...HIGH TEMPERATURES WILL TREND WARMER IN THE UPPER 70S TO LOWER 80S AWAY FROM THE LOCALLY COOLER COASTLINE. LOW TEMPERATURES WILL ALSO MODERATE WEDNESDAY NIGHT WITHIN THE WARMER FLOW AND HIGHER DEWPOINTS. THURSDAY...SHORTWAVE ENERGY AND AN ASSOCIATED SURFACE LOW WILL MOVE FROM THE GREAT LAKES REGION INTO THE NEW ENGLAND STATES WEDNESDAY NIGHT INTO EARLY THURSDAY...PULLING A TRAILING COLD FRONT SOUTHWARD THROUGH THE MID ATLANTIC AND SOUTHEAST STATES LATER IN THE DAY. LATEST NUMERICAL MODEL SOLUTIONS SUGGEST LOW AND MID LEVEL FLOW WILL GENERALLY REMAIN WEST DURING FRONTAL PASSAGE...EVIDENCE THAT THE SYSTEM WILL BE LACKING A DECENT TAP INTO DEEPER MOISTURE. RAIN POTENTIAL THUS APPEARS QUITE LIMITED ON THURSDAY AND PREFER TO KEEP RAIN CHANCES BELOW 15 PERCENT AT THIS POINT. SINCE THE WIND SHIFT ASSOCIATED WITH THE PASSING FRONT WILL BE DELAYED UNTIL THURSDAY EVENING...TEMPERATURES ARE EXPECTED TO WARM INTO THE LOWER 80S AWAY FROM THE COAST WITHIN SOME PRE-FRONTAL COMPRESSION. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... THE WEAK FRONT WILL CONTINUE TO PUSH THROUGH THE AREA FROM NORTH TO SOUTH THURSDAY NIGHT...SETTLING SOUTH OF THE AREA ON FRIDAY. ANOTHER AREA OF HIGH PRESSURE WILL THEN BUILD OVER THE NORTHEAST STATES. AFTER A WARM-UP MID WEEK...TEMPERATURES WILL COOL DOWN AGAIN BY A FEW DEGREES. RIGHT NOW...THE WEEKEND LOOKS UNSETTLED. AN AREA OF SHORTWAVE ENERGY THAT COMES ASHORE IN SOUTHERN CALIFORNIA MID WEEK WILL WORK ITS WAY ACROSS THE SOUTHERN TIER OF THE U.S. AND APPROACH FROM THE LOWER MISSISSIPPI VALLEY LATER SATURDAY INTO SUNDAY. TIMING AND DETAILS ARE TOO TOUGH TO PIN DOWN THIS FAR OUT...BUT WE WILL DEFINITELY SEE AN INCREASE IN CLOUDS AND CHANCES OF RAIN FOR SATURDAY AFTERNOON INTO SUNDAY...WITH SOME IMPROVING CONDITIONS POSSIBLE BY MONDAY. && .AVIATION /22Z MONDAY THROUGH SATURDAY/... VFR FOR THE NEXT 24 HOURS AT KCHS/KSAV. EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER THAN 30 PERCENT CONFIDENCE FACTOR. && .MARINE... INCOMING RUC DATA SUGGESTS THE FRONT AND ITS ACCOMPANYING SURGE WILL ARRIVE ACROSS THE CHARLESTON COUNTY COASTAL WATERS AND THE CHARLESTON HARBOR A FEW HOURS EARLIER THAN EXPECTED. HAVE ADJUSTED THE START TIMES OF THE SMALL CRAFT ADVISORIES FOR THESE ZONES GIVEN THESE TRENDS. NO OTHER CHANGES WERE MADE FOR THE TONIGHT PERIOD. WINDS AND SEAS WILL REMAIN ELEVATED EARLY TUESDAY...AS THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO BUILDING HIGH PRESSURE BEHIND A DESCENDING COLD FRONT. WILL CONTINUE SMALL CRAFT ADVISORIES FOR THE CHARLESTON HARBOR THROUGH NOON ON TUESDAY...WHILE MAINTAINING ADVISORIES FOR THE NEARSHORE WATERS THROUGH THE AFTERNOON HOURS. A BETTER FETCH OVER THE OUTER GEORGIA WATERS WILL MAINTAIN ADVISORY-LEVEL SEAS THROUGH TUESDAY NIGHT. SURFACE HIGH PRESSURE WILL STEADILY DRIFT SOUTHWARD AND INTO THE ATLANTIC TUESDAY NIGHT THROUGH WEDNESDAY...ALLOWING WINDS AND SEAS TO DIMINISH WITH THE RELAXING PRESSURE GRADIENT. THE GRADIENT WILL THEN INCREASE AGAIN AS A BACKDOOR COLD FRONT DESCENDS TOWARD THE REGION LATE WEDNESDAY INTO THURSDAY. EXPECT WINDS AND SEAS TO RISE ACCORDINGLY...HOWEVER HEADLINES ARE NOT ANTICIPATED AT THIS TIME. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 1 PM EDT TUESDAY FOR AMZ330. SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT TUESDAY FOR AMZ352. SMALL CRAFT ADVISORY FROM 1 AM TO 5 PM EDT TUESDAY FOR AMZ350. SMALL CRAFT ADVISORY FROM 7 AM TUESDAY TO 2 AM EDT WEDNESDAY FOR AMZ374. SMALL CRAFT ADVISORY FROM 7 AM TO 5 PM EDT TUESDAY FOR AMZ354. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
500 PM CDT MON MAR 26 2012 .UPDATE... ISSUED AT 455 PM CDT MON MAR 26 2012 HAVE TRIMMED POPS FOR THIS EVENING DUE TO LAPS/SPC MESOANALYSIS SHOWING SBCAPE AROUND 500 J/KG BUT CINH AROUND NEGATIVE 200 TO 400 J/KG. DEWPOINTS ARE MIXING OUT THIS AFTERNOON AND ARE ONLY IN THE LOWER 40S ACROSS WESTERN KANSAS. FOLLOWED THE LATEST HRRR FOR GUIDANCE. HAVE DOUBTS ANY ORGANIZED CONVECTION WILL FORM THIS EVENING AND THE INSTABILITY THAT IS CURRENTLY PRESENT WILL ALL GO TO MID LEVEL CLOUD FORMATION. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 215 PM CDT MON MAR 26 2012 THE MAIN FORECAST FOCUS WILL BE ON THE CHANCE FOR PRECIP DURING THE PERIOD. SHORT RANGE MODELS INDICATE THE UPPER LEVEL TROUGH LIFTING NORTHEAST ACROSS THE NORTHERN ROCKIES INTO THE NORTHERN PLAINS TONIGHT BRINGING THE POSSIBILITY FOR SHOWERS AND THUNDERSTORMS ACROSS THE DAKOTAS SOUTHWARD INTO NEBRASKA, POTENTIALLY AS FAR SOUTH AS KANSAS. AS THE UPPER LEVEL WAVE BEGINS TO PUSH OUT OF THE NORTHERN ROCKIES THIS EVENING, THE SURFACE TROUGH IN EASTERN COLORADO AND AN ASSOCIATED SHARPENING DRYLINE IS EXPECTED TO PUSH SLOWLY EASTWARD INTO EXTREME WESTERN KANSAS INCREASING FORCING NEAR THE SURFACE. THIS WILL ALSO SUPPORT AN INCREASING LOW LEVEL SOUTHERLY FLOW INTO WESTERN KANSAS HELPING TO POOL SOME MOISTURE AHEAD OF THE ADVANCING TROUGH. HOWEVER, THE BEST UPPER LEVEL DYNAMICS ASSOCIATED WITH THE SYSTEM...INCLUDING A MODEST +70KT JET...WILL SKIRT JUST OFF TO OUR NORTHWEST. ADDITIONALLY, THE DEEPER LAYER MOISTURE WILL ALSO REMAIN JUST OFF TO OUR NORTH. ALTHOUGH THE NAM AND GFS MODEL SOUNDINGS POINT TO STEEPENING LAPSE RATES ACROSS WESTERN KANSAS, THERE IS A LACK OF INSTABILITY (LOW CAPE) DUE TO THE LACK OF MOISTURE IN THE LOWER LEVELS, NOT TO MENTION A POSSIBLE CAPPING ISSUE. STILL, CANNOT RULE OUT AN ISOLATED STORM OR TWO ASSOCIATED WITH THE DRYLINE AS IT TRACKS EAST ACROSS WESTERN KANSAS OVERNIGHT. SLIGHT POPS SEEM REASONABLE HERE. TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL TONIGHT AS THE APPROACHING LEE SIDE TROUGH CONTINUES TO ENHANCE WARM AIR ADVECTION INTO WESTERN KANSAS WITHIN A LOW LEVEL SOUTHERLY FLOW. LOOK FOR LOWS MAINLY DOWN INTO THE 50S(F) AHEAD OF THE TROUGH WHERE SURFACE DEWPOINTS SHOULD REMAIN IN THE 40S(F) TO LOW 50S(F). A FEW 40S(F) ARE POSSIBLE ACROSS FAR WEST AND WEST CENTRAL KANSAS WHERE WINDS ARE EXPECTED TO GO NORTHERLY BEHIND A WEAK COLD FRONT EDGING INTO WESTERN KANSAS EARLY TUESDAY MORNING. FOR TUESDAY, A SMALL AREA OF SURFACE HIGH PRESSURE IS PROJECTED TO WORK EASTWARD INTO WESTERN KANSAS DURING THE DAY BRINGING SLIGHTLY COOLER AIR INTO THE REGION WITH H85 TEMPERATURES IN THE MID TEENS(C). SHOULD SEE HIGHS UP INTO THE 70S(F) FOR THE MOST PART WITH LOWER 80S(F) POSSIBLE ACROSS SOUTH CENTRAL KANSAS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 344 PM CDT MON MAR 26 2012 THE 12Z RUNS OF THE GFS/ECMWF/CANADIAN AND UKMET ARE ALL IN FAIRLY DECENT AGREEMENT WITH THE UPPER LEVEL FLOW PATTERN THROUGH DAY 5 BEFORE STARTING TO DIVERGE IN THEIR SOLUTIONS. AT THE BEGINNING OF THE LONG TERM PERIOD ON TUESDAY NIGHT...THE STRONG UPPER LEVEL SHORTWAVE TROUGH THAT IS CURRENTLY LIFTING OUT OF THE WESTERN STATES INTO THE NORTHERN PLAINS WILL HAVE MOVED INTO THE GREAT LAKES REGION WHILE A SHORTWAVE RIDGE MOVES EAST TOWARD THE NORTHERN AND CENTRAL PLAINS. THE MODELS SHOW A STALLED FRONTAL BOUNDARY OVER SOUTH CENTRAL KANSAS SOMEWHERE IN THE VICINITY OF STAFFORD TO MEDICINE LODGE AND COLDWATER. THE MODELS ARE ALL SHOWING A PRECIPITATION SIGNAL ALONG THE FRONT. WITH DEWPOINTS PROGGED TO BE IN THE LOW 60S AROUND MEDICINE LODGE, MODEL SOUNDINGS SHOW THE ATMOSPHERE NEARLY UNCAPPED BY LATE AFTERNOON WITH SOME MODERATE CAPE VALUES FORECAST. AN EIGHTY KNOT JET WILL BE MOVING EAST ACROSS SOUTH DAKOTA THROUGH THE EVENING AND OVERNIGHT HOURS WHICH COULD ALSO PROVIDE A LITTLE UPPER LEVEL SUPPORT FOR STORMS. WILL MAINTAIN THE SLIGHT CHANCE POPS FORECAST FOR SOUTH CENTRAL KANSAS. FARTHER NORTHWEST IT APPEARS THAT THE ATMOSPHERE SHOULD BE SUFFICIENTLY CAPPED TO PREVENT ANY THUNDERSTORM DEVELOPMENT. THE WEATHER SHOULD BE FAIRLY QUIET ON WEDNESDAY WITH THE SHORTWAVE RIDGE MOVING OVER THE CENTRAL HIGH PLAINS. BY WEDNESDAY NIGHT LOW LEVEL SOUTHERLY FLOW INCREASES ESPECIALLY INTO SOUTH CENTRAL KANSAS. WITH LOW LEVEL MOISTURE INCREASING INTO THE AREA WE COULD SEE THUNDERSTORMS DEVELOPING AGAIN WITH THE BEST CHANCES AROUND HIGHWAY 281 AND EAST. THERE IS SOME UNCERTAINTY AS TO THE POSITION AND STRENGTH OF THE FRONTAL BOUNDARY FOR NOW WILL KEEP THE POPS IN THE PRATT-MEDICINE LODGE-COLDWATER AREAS. THE MODELS SHOW A WEAK SHORTWAVE TROUGH APPROACHING THE CENTRAL CONUS ON THURSDAY. THE GFS SHOWS A WEAK COOL FRONT PUSHING ACROSS WESTERN KANSAS. WILL CONTINUE THE CHANCE POPS THAT ARE CURRENTLY IN THE FORECAST FOR THURSDAY NIGHT. TOWARD DAY 7 THE MODELS DIFFER SOMEWHAT WITH THE STRENGTH AND TRACK OF ANOTHER STRONG SHORTWAVE MOVING IN FROM THE PACIFIC. THE MODELS HAVE STRUGGLED WITH THIS FROM RUN TO RUN SO CONFIDENCE IN ANY ONE SOLUTION IS PRETTY LOW. THE GFS MODEL SHOWS A FAIRLY STRONG COLD FRONT PUSH THROUGH WESTERN KANSAS LATE IN THE WEEKEND WITH SOME POTENTIAL FREEZING TEMPERATURES. WILL HAVE TO KEEP AN EYE ON THIS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1200 PM CDT MON MAR 26 2012 VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH EARLY TUESDAY MORNING. AS FOR WINDS, A STRONG LEE SIDE TROUGH OF LOW PRESSURE WILL EDGE SLOWLY EASTWARD INTO EXTREME WESTERN KANSAS TONIGHT. AS A RESULT, SOUTHERLY WINDS OF 25 TO 35KT WILL CONTINUE INTO EARLY THIS EVENING THEN GRADUALLY SUBSIDE WEST TO EAST OVERNIGHT AS THE TROUGH PUSHES THROUGH. && .PRELIMINARY POINT TEMPS/POPS... DDC 50 77 49 81 / 20 0 10 10 GCK 46 75 45 80 / 20 0 10 10 EHA 45 75 43 80 / 10 0 0 0 LBL 50 77 45 81 / 20 0 0 10 HYS 50 75 46 80 / 10 0 10 10 P28 57 80 56 82 / 0 10 20 10 && .DDC WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR KSZ030- 031-043>046-061>066-074>080-084>089. && $$ UPDATE...SUGDEN SHORT TERM...JJOHNSON LONG TERM....GERARD AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1135 AM MDT MON MAR 26 2012 .SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT) ISSUED AT 143 AM MDT MON MAR 26 2012 03Z WATER IMAGERY INDICATED LARGE UPPER LEVEL RIDGE IN PLACE ACROSS THE PLAINS WITH SHORT WAVE TROUGH/CLOSED LOW CIRCULATION ENTERING SOUTHERN CALIFORNIA. AT THE SFC...AREA OF LOW PRESSURE WAS IN PLACE ACROSS SOUTHEAST COLORADO IN A SIMILAR POSITION FROM 24 HOURS AGO...WITH LIGHT EASTERLY FLOW ACROSS NORTHERN HALF OF THE AREA. 00Z RAOBS INDICATED A SHARP CHANGE IN MOISTURE CONTENT FROM WEST TO EAST ACROSS THE PLAINS WITH FAIRLY LARGE INCREASES IN MOISTURE BELOW H75 NOTED AT KDDC AND KLBF FROM 24 HOURS AGO...AS EVIDENCED BY +0.3 CHANGE IN PRECIPITABLE WATER OVER THAT TIME. ASIDE FROM OVERNIGHT FOG AND VERY SMALL THUNDERSTORM CHANCES...MAIN FORECAST CONCERNS WILL BE WINDS/FIRE WX AND THUNDERSTORM CHANCES TODAY AND TONIGHT. TODAY-TONIGHT...ALTHOUGH SOME ELEVATED INSTABILITY WILL LINGER AROUND DURING THE MORNING HOURS WITH LATEST RUNS OF HRRR TRYING TO BREAK OUT SOME WEAK CONVECTION AROUND 12Z...ISENTROPIC FIELDS SUGGEST BULK OF FORCING ALONG NOSE OF LLJ WILL BE WELL TO THE NORTH AND EAST OF THE CWA AND WITH CONDENSATION DEFICITS IN EXCESS OF 130 MB...SEEMS DOUBTFUL ANY MORNING INSTABILITY WOULD BE REALIZED AND THINK BULK OF MORNING WX CONCERNS WILL CENTER AROUND ANY LINGERING FOG AROUND SUNRISE. WITH WINDS SHIFTING AROUND TO THE SOUTHWEST AND INCREASING DO NOT THINK FOG WILL BE AS WIDESPREAD OR DENSE LIKE YESTERDAY...BUT WILL MONITOR OBSERVATIONS CLOSELY AND ADJUST AS TRENDS DICTATE. BEST...ALBEIT SMALL...CHANCE FOR PRECIP WILL BE BETWEEN 21 AND 03Z AS CONVERGENCE ALONG DRYLINE REALLY BEGINS TO SHARPEN AND LOW LEVEL FRONTOGENESIS INCREASES. AREA WILL STILL BE PRETTY FAR REMOVED FROM LARGE SCALE FORCING FOR ASCENT AS UPPER TROUGH PASSES ACROSS WYOMING AND WITH STRONG CAP/CINH IN PLACE HAVE DOUBTS ABOUT CONVECTIVE INITIATION AND IF STORMS WOULD ACTUALLY SURVIVE FOR VERY LONG AS THEY MOVED AWAY FROM SFC FORCING. STILL FEEL SMALL POPS WARRANTED AND GIVEN SHEAR/INSTABILITY PROFILES THERE IS A SMALL CHANCE FOR AN ORGANIZED STORM OR TWO AS THINGS INITIATE NEAR THE KS/CO BORDER AND GRADUALLY SHIFT EAST IN THE EVENING. WITH THE RATHER SMALL PROBABILITIES FOR THUNDERSTORMS...WINDS AND FIRE WX WILL CONTINUE TO BE THE MAIN CONCERN FOR THE PERIOD AS WINDS WILL INCREASE RAPIDLY DURING THE AFTERNOON IN RESPONSE TO STRENGTHENING LOW ACROSS THE NEBRASKA PANHANDLE. WINDS SHOULD PRETTY EASILY MEET ADVISORY CONDITIONS ACROSS THE ENTIRE AREA...BUT HAVE A FEW CONCERNS THAT HIGHER GUSTS APPROACHING WARNING CRITERIA MAY OCCUR WITH THE MUCH DEEPER MIXING EXPECTED TO THE WEST OF DRYLINE. OPERATIONAL GUIDANCE NOT REALLY GIVING A SOLID CONSENSUS IN THIS REGARD AND WITH MIXED LAYER DATA GENERALLY TOPPING AT AROUND 48 KTS AND A WEAKER SFC LOW THAN LAST WEEK...THINK CONFIDENCE TOO LOW TO UPGRADE ADVISORY TO WARNING AT THIS POINT. FOR FIRE WEATHER CONDITIONS...THINK DRY LINE WILL HUG KS/CO BORDER FOR MUCH OF THE DAY AS STRONG PRESSURE FALLS OCCUR TO THE NORTHEAST. HOWEVER AS LOW BEGINS TO LIFT INTO THE NEBRASKA PANHANDLE...EXPECT DRYLINE TO START ADVANCING EASTWARD. IT WILL BE MARGINAL FROM A DURATION ASPECT...BUT FEEL UPGRADING FIRE WEATHER WATCH TO WARNING IS APPROPRIATE. TUESDAY...FRONTAL ZONE WILL STALL ACROSS SOUTHERN KANSAS DURING THE MORNING HOURS AS COOLER AIR SETTLES OVER THE AREA WITH ADVANCING SFC RIDGE. WITH A MORE STABLE AIRMASS SETTLING OVER THE AREA AND SHORT WAVE RIDGING STARTING TO DEVELOP...EXPECT DRY CONDITIONS AND GENERALLY CLEAR SKIES. ONLY SIG WEATHER CONCERN WILL BE MAGNITUDE OF DRY AIR THAT WILL BE ADVECTED INTO AREA BEHIND FRONT. ALTHOUGH AFTERNOON HUMIDITIES WILL FALL TO AROUND 15 PERCENT...POSITION OF SFC HIGH WILL LIKELY BRING LIGHT/VARIABLE WINDS TO MUCH OF THE AREA MITIGATING THE FIRE WX THREAT. COULD POSSIBLY SEE STRONGER WINDS ACROSS NEBRASKA COUNTIES...BUT THINK WITH CURRENT FIRE HIGHLIGHTS AND OVERALL LOW CONFIDENCE IN STRONGER WINDS DO NOT FEEL WATCH WARRANTED AT THIS TIME. TUESDAY NIGHT-WEDNESDAY NIGHT...SLOWLY RETREATING FRONTAL ZONE WILL LIKELY BE MAIN CONCERN FOR THE PERIOD AS NOT ONLY WILL THIS FEATURE PROVIDE A POTENTIAL FOCUS FOR THUNDERSTORM DEVELOPMENT...IT WILL ALSO BRING MUCH MORE HUMID AIR BACK TO THE CWA. GIVEN CWA WILL GENERALLY BE UNDER A FAIRLY WEAK SHORT WAVE RIDGE FOR MOST OF THE PERIOD...HAVE DOUBTS THAT FRONT WILL MAKE A RAPID NORTHERLY SURGE AND PREFER THE MORE SOUTHERLY SOLUTION GIVEN BY NAM AND LATEST ENSEMBLE MEANS. IF THERE IS A CHANCE FOR PRECIPITATION THIS PERIOD...THINK MOST LIKELY PERIOD WILL BE OVERNIGHT WEDNESDAY AS LLJ INCREASES THROUGH 06Z IN RESPONSE TO SHORT WAVE TROUGH MOVING ACROSS NORTHERN ROCKIES. NOT ONLY WILL THIS BRING A STRONG SURGE OF MOISTURE/INSTABILITY INTO AREA...BUT ISENTROPIC SURFACES SUGGEST FORCING WILL BE FOCUSED ACROSS EASTERN CWA DURING THE EVENING/OVERNIGHT HOURS. STILL A LOT OF CONCERNS ABOUT WHETHER OR NOT PARCELS WILL SATURATE AND INSTABILITY BE REALIZED...BUT THINK A SMALL THREAT FOR STORMS IS WARRANTED. IN ADDITION TO PRECIP POTENTIAL...INCREASING LOW LEVEL MOISTURE BOTH NIGHTS WILL LIKELY PROVIDE A FAVORABLE ENVIRONMENT FOR FOG FORMATION. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 1254 AM MDT MON MAR 26 2012 ZONAL FLOW WILL BE IN PLACE ACROSS THE CONUS TO START THIS PERIOD. WEAK SHORTWAVE TROUGHS WILL BE MOVING ACROSS THE CENTRAL ROCKIES AND ADJACENT PLAINS BOTH THURSDAY AND FRIDAY. APPEARS THERE WILL BE AT LEAST SOME MOISTURE AVAILABLE AND COUPLED WITH WEAK INSTABILITY WILL CARRY SLIGHT TO LOW CHANCE POPS FOR AFTERNOON/EVENING THUNDERSTORMS BOTH DAYS. UPPER RIDGE WILL BUILD ACROSS THE PLAINS FOR THE REMAINDER OF THE PERIOD AHEAD OF STRONG SYSTEM DIGGING INTO THE FOUR CORNERS. MODEL SOLUTIONS DIVERGE ON HOW TO HANDLE THAT SYSTEM VERY LATE IN THE PERIOD...SO WILL NOT CARRY ANY MENTION OF PRECIPITATION ATTM. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE ENTIRE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1135 AM MDT MON MAR 26 2012 STRONG SOUTHERLY WINDS WILL PREVAIL AT THE TERMINALS THIS AFTERNOON DUE TO A LOW PRESSURE CENTER TO THE NORTH OF THE TERMINALS. THERE WILL BE A SLIGHT POSSIBILITY FOR THUNDERSTORMS EAST OF A DRYLINE THIS AFTERNOON AND INTO THE EARLY EVENING. AS A COLD FRONT MOVES THROUGH THE TERMINALS THIS EVENING...WINDS WILL SHIFT TO THE WEST-NORTHWEST...AND WHILE GUSTS ARE NOT EXPECTED TO BE AS STRONG THIS EVENING AS THEY WERE THIS AFTERNOON...WIND GUSTS CAN STILL BE EXPECTED UNTIL THE PRESSURE GRADIENT RELAXES DURING THE EARLY MORNING HOURS. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT...ALLOWING LIGHT WINDS AND CLEAR SKIES ON TUESDAY MORNING AT KGLD...BUT WIND GUSTS SHOULD RETURN TO KMCK GIVEN ITS PROXIMITY TO THE HIGH PRESSURE CENTER. && .FIRE WEATHER... ISSUED AT 143 AM MDT MON MAR 26 2012 CRITICAL TO EXTREMELY CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY...MAINLY ALONG AND WEST OF THE KANSAS AND COLORADO STATE LINE AS A DRYLINE SLOWLY ADVANCES TO THE EAST TODAY. STRONG SOUTHERLY WINDS OF 25 TO 35 MPH WITH GUSTS TO AROUND 55 MPH WILL COMBINE WITH HUMIDITIES AROUND 10 PERCENT DURING THE AFTERNOON AND EARLY EVENING HOURS. A COLD FRONT WILL BEGIN TO MOVE ACROSS THE AREA TONIGHT...BRINGING A SUDDEN SHIFT IN THE WINDS AND A BRIEF PERIOD OF STRONG NORTHWESTERLY WINDS. A VERY DRY AIR MASS WILL SETTLE OVER THE AREA ON TUESDAY BRINGING HUMIDITIES DOWN TO AROUND 15 PERCENT DURING THE AFTERNOON. WHILE WINDS WILL BE LIGHT AND VARIABLE ACROSS MUCH OF THE AREA...THERE IS POTENTIAL FOR STRONGER WINDS AND CRITICAL FIRE WEATHER CONDITIONS ACROSS SOUTHWEST NEBRASKA. IF WINDS DO OCCUR...WILL LIKELY BE A MUCH SMALLER MAGNITUDE OF EVENT THAN TODAY AND CHOSE TO NOT ISSUE A FIRE WEATHER WATCH TO AVOID CONFUSION ABOUT TODAYS WARNING. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ252>254. WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR COZ090>092. KS...RED FLAG WARNING UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ001-013-027-041. WIND ADVISORY UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ001>004-013>016-027>029-041-042. NE...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR NEZ079. WIND ADVISORY UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR NEZ079>081. && $$ SHORT TERM...JRM LONG TERM....024 AVIATION...CJS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
650 PM EDT MON MAR 26 2012 .SYNOPSIS... AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL CROSS THE AREA THIS EVENING. HIGH PRESSURE WILL BUILD EAST TUESDAY...CROSS THE REGION TUESDAY NIGHT...THEN MOVE EAST WEDNESDAY. LOW PRESSURE FROM THE UPPER GREAT LAKES MAY BRING LIGHT PRECIPITATION TO MOSTLY WESTERN AND DOWNEAST PORTIONS OF THE REGION LATE WEDNESDAY INTO THURSDAY. && .NEAR TERM /THROUGH TUESDAY/... UPDATE... SOME CONCERNS THAT WIND ADVISORY MADE BE NEED TO BE MOVED UP AS SOME GUSTS CLOSING CLOSE TO 45-50 MPH MAINLY OVER HIGHER TERRAIN. THE RUC INDICATES WINDS PICKING UP LATER TONIGHT AND CONTINUING INTO MIDDAY TUESDAY AS DOES THE 18Z RUN OF THE NAM. ATTM, WILL KEEP THINGS AS THEY W/WIND ADVISORY. ADJUSTMENTS WERE MADE TO LOWER MINS TONIGHT DOWN A CATEGORY W/SINGLE NUMBERS ACROSS THE FAR N AND W. PREVIOUS DISCUSSION... STRONG LLVL COLD ADVCN ON STIFF NW WINDS DID NOT ALLOW FOR MUCH TEMP RISE THIS AFTN...SO WE HAD TO LOWER AFTN HI TEMPS AGAIN JUST TO GET A REALISTIC HRLY TEMP TREND TO FCST LOWS POSTED ARND 6-7 AM EDT TUE. MDTLY STRONG SFC PRES GRAD WINDS ACROSS ALL OF THE F AND SOME CLDNSS OVR NRN/CNTRL PTNS OF THE REGION TNGT WILL NOT ALLOW FOR ANY XPCTD INVSN TO FORM...SO WE WENT STRAIGHT WITH RAW NAM FCST LOW TEMPS. WE KEPT CHC SN SHWR POPS FOR FAR NRN PTNS OF THE FA FOR THIS EVE AS THE UPPER LOW OVR THE GASPE PNSL MOVES SE INTO NE NB. OTHERWISE...CLDS SHOULD DECREASE OVR THE N AND CNTRL PTNS OF THE FA LATER TNGT INTO ERLY TUE MORN. WINDS...WHICH HAVE BEEN GUSTING AS HIGH AS LOWER 4OS MPH A FEW SITES WILL DIMINISH A LITTLE OVRNGT OVR LOW LYING AREAS...BUT WILL REMAIN FAIRLY STRONG OVR OPEN HIER TRRN AREAS. WINDS ALF... SPCLY IN THE 925-850 MB LAYER WILL INCREASE TO AOA 40 KT LATER TNGT INTO TUE MORN ACROSS THE FA AS THE SFC PRES GRAD REMAINS STRONG BETWEEN SLOWLY DEPARTING LOW PRES IN THE MARITIMES AND HI PRES OVR WRN QB. THIS IN COMBO WITH MSLY SUNNY SKIES XPCTD ACROSS ALL OF THE REGION ON TUE WILL STEEPEN SFC-1 KM LAPSE RATES... ALLOWING POTENTIAL MIX DOWN OF THESE STRONGER WINDS ALF IN GUSTS...BEGINNING SHORTLY AFT DAYBREAK TUE DUE TO THE WEAKNESS OF ANY ESTABLISHED BL TNGT AND CONTG TIL ABOUT SUNSET...AT WHICH TM...WINDS ALF...SFC PRES GRAD AND LLVL INSTABILITY ALL BEGIN DECREASING. WITH ALL OF THIS IN MIND...HI TEMPS TUE AFTN WILL BE LUCKY TO HAVE A 10 TO 15 DEG F DIURNAL RISE FROM LOWS ERLY TUE MORN...RANGING FROM MID 20S XTRM N TO MID TO UPPER 30S DOWNEAST...MAKING TUE QUITE A CONTRAST FROM THE RECORD WARM DAYS OF MID LAST WEEK. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... WINDS WILL DIMINISH TUESDAY NIGHT AS A RIDGE OF HIGH PRESSURE BRIEFLY SETS UP OVER THE REGION. HOWEVER BY THE OVERNIGHT CLOUDS WILL ALREADY BY ON THE INCREASE IN ADVANCE OF THE NEXT SYSTEM APPROACHING FROM THE GREAT LAKES. THE INCREASING CLOUDS SHOULD KEEP TEMPERATURES FROM BOTTOMING OUT AS LOW AS SOME WHAT SOME OF THE GUIDANCE IS INDICATING BUT NEVERTHELESS, EXPECT LOWS TO BE GENERALLY IN THE TEENS. AS THE SYSTEM CONTINUES TO ADVANCE EASTWARD WEDNESDAY THE CHANCES FOR LIGHT PRECIPITATION IN THE FORM OF MIXED RAIN/SNOW WILL DEVELOP FROM WEST TO EAST THROUGH THE DAY. THE FORECAST BECOMES A BIT TRICKY FOR WEDNESDAY NIGHT INTO THURSDAY. THE GEM GLOBAL AND THE NAM TRACK THE SYSTEM EAST GIVING MOST OF THE AREA A CONTINUING PERIOD OF GENERALLY LIGHT PRECIPITATION WHILE THE GFS AND THE EURO ARE QUICKER TO SHUNT THE SYSTEM OFF TO THE SOUTH AND EAST IN RESPONSE TO THE CIRCULATION AROUND AN UPPER LEVEL LOW OVER ATLANTIC CANADA. AT THIS POINT OPTED TO PLAY THE MIDDLE GROUND AND BRING CHANCE POPS TO ALL BUT EXTREME NORTHERN AND EASTERN AREAS DURING THIS PERIOD AND HOLDING POPS JUST BELOW THE LIKELY RANGE OVER THE SOUTH AND WEST. NORTHERLY WINDS COMBINED WITH THE DIURNAL CYCLE WILL ALLOW FOR ANY MIXED PRECIP OR RAIN TO CHANGE TO ALL SNOW WEDNESDAY NIGHT WITH SOME MIXING LIKELY ONCE AGAIN FOR THURSDAY. THE SYSTEM LOOKS TO BE MAINLY SOUTH AND EAST OF THE REGION BY LATE DAY THURSDAY. THERE IS THE POTENTIAL FOR SOME SNOW ACCUMULATION TO HAVE OCCURRED BY THIS TIME MAINLY OVER WESTERN SECTIONS ALTHOUGH AT THIS POINT ANY AMOUNTS DO NOT LOOK LIKELY TO BE SIGNIFICANT DUE TO THE RELATIVELY MILD TEMPERATURES AND GENERALLY LIGHT NATURE OF THE PRECIP. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... LOW PRESSURE WILL CONTINUE TO MOVE EAST OF THE REGION THURSDAY NIGHT. A DRIER NW FLOW WILL FOLLOW FOR THURSDAY NIGHT AND FRIDAY WITH CLEARING SKIES EXPECTED THURSDAY NIGHT AND MOSTLY SUNNY SKIES FRIDAY. HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE REGION FRIDAY NIGHT THROUGH SATURDAY WITH CONTINUED DRY WEATHER. LOW PRESSURE WILL PASS TO OUR SOUTH SATURDAY NIGHT AND SUNDAY SO EXPECT MAINLY DRY WEATHER THROUGH THE UPCOMING WEEKEND. HIGH PRESSURE WILL BUILD BACK ACROSS THE REGION ON MONDAY. TEMPERATURES WILL BE NEAR OR A BIT ABOVE NORMAL FOR THIS TIME OF YEAR THROUGH THE PERIOD. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... NEAR TERM: VFR WITH A PD OF MVFR CLGS IN BKN-OVC TNGT AT KFVE AND POSSIBLE AT KCAR AND KPQI. SHORT TERM: EXPECT VFR CONDITIONS THROUGH TUESDAY NIGHT. MVFR/IFR CONDITIONS WILL BE POSSIBLE BY LATE DAY WEDNESDAY INTO THURSDAY, ESPECIALLY SOUTH, DUE TO THE NEXT SYSTEM BRINGING THE CHANCE FOR SNOW/RAIN AND LOW CLOUDS. && .MARINE... NEAR TERM: WILL CONT THE GLW OVR ALL OF OUR WATERS THRU MOST OF TUE AFTN AS ADVERTISED OVR THE PAST DAY OR SO. ONCE IT RUNS OUT... AN SCA WILL BE NEEDED FOR ALL OF WATERS VERY LATE TUE AFTN INTO TUE EVE. WENT WITH AN EVEN BLEND 12Z GFS/NAM/GMOS FOR WINDS AND A 40%/30%/30% WW3/SWAN-GFS/SWAN NAM BLEND FOR WV HTS...WHICH RAISE WV HTS BY WW3 ALONE AN XTRA FOOT TO FOOT AND A HALF OVR OUTER MOST WATERS. SHORT TERM: WINDS AND WAVES WILL DIMINISH THROUGH TUESDAY NIGHT AND WILL BE BELOW SCA LEVELS BY WEDNESDAY MORNING. HOWEVER THE NEXT SYSTEM WILL BRING THE CHANCE FOR RAIN/SNOW BY LATE DAY WEDNESDAY CONTINUING INTO THURSDAY AND WILL ALSO BRING THE POTENTIAL FOR SCA CONDITIONS ALONG WITH REDUCED VISIBILITIES. && .FIRE WEATHER... AFTER COORDINATING WITH THE ST OF ME FOREST SERVICE...WE OPTD TO ISSUE A FIRE WX WATCH FOR ZONES 5...6 SWRD TO THE COAST. AREAS N AND W OF THE WATCH AREA HAVE FINE FUELS DEEMED TO WET TO BE ABLE TO DRY OUT FOR POSSIBLE IGNITION. WITHIN THE WATCH AREA... FINE FUELS HAVE BEEN DAMPENED FROM RELATIVELY LGT QPF FROM YSDY`S PRECIP EVENT...BUT VERY STRONG WINDS AND LOW MIDDAY AND AFTN RH`S COULD DRY OUT FUELS TO HIGH DANGER RATING CATEGORY. GIVEN UNCERTAINTY OF DRYING POTENTIAL BETWEEN NOW AND MIDDAY TUE...IT`S A TOSS UP WHETHER THE WATCH WILL BE UPGRADED TO A RED FLG WRNG FOR ALL OR PARTS OF THE WATCH AREA MIDDAY TIL ERLY EVE TUE OR TO AN SPS HIGHLIGHTING NO BURNING OF REFUGE DURG THIS TM. A DECISION WILL BE MADE REGARDING THESE OPTIONS LATE TUE MORN. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...WIND ADVISORY FROM 7 AM TO 7 PM EDT TUESDAY FOR MEZ001>006-010- 011-015>017-029>032. FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR MEZ005-006-011-015>017-029>032. MARINE...GALE WARNING UNTIL 5 PM EDT TUESDAY FOR ANZ050>052. && $$ NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
418 PM EDT MON MAR 26 2012 .SYNOPSIS... ISSUED AT 417 PM EDT MON MAR 26 2012 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPRAWLING UPR RDG OVER CNTRL NAMERICA BTWN TROFS OVER QUEBEC/NEW ENGLAND AND ANOTHER OFF THE W COAST. HUDSON BAY HI PRES UNDER THE CONFLUENT NW FLOW ALF BTWN THE RDG AND ERN TROF AS WELL AS VERY DRY AIRMASS DEPICTED ON THE 12Z INL AND GRB RAOBS /12Z H85 DEWPT DEPRESSION WAS 43C AT INL/ ARE BRINGING A TRANQUIL BUT MORE SEASONABLY CHILLY DAY TO UPR MI. BUT MORE CLDS WELL IN ADVANCE OF SHARP WARM FNT ATTENDANT TO DVLPG LO PRES IN THE NW HI PLAINS ARE SPREADING FM MN/NW WI TOWARD IWD. THIS SFC LO IS ASSOCIATED WITH VIGOROUS NEGATIVELY TILTED SHRTWV LIFTING NEWD OUT OF THE DESERT SW. THE WARM FNT SEPARATES VERY WARM AIRMASS IN THE SRN PLAINS WITH 12Z H85 TEMP AS HI AS 20C AT DODGE CITY KS FM CHILLY AIRMASS IN THE GRT LKS/H85 TEMPS OF -8C AT YPL AND APX. SOME -SHRASN ARE FALLING OVER PARTS OF MN/NW WI UNDER THE THICKER CLDS/ SHARPER H85-7 FGEN AS 12Z MPX RAOB SHOWS A SATURATED LYR FM H85-5. THERE HAVE BEEN A FEW LTG STRIKES UNDER THIS BAND OF SHRA TODAY. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 417 PM EDT MON MAR 26 2012 MAIN FCST CONCERNS TNGT INTO TUE ARE MIXED PCPN/ICING POTENTIAL/ GOING FZRA ADVY ASSOCIATED WITH APRCHG WARM FNT...THEN SHRA CHCS ON TUE WITH ARRIVAL OF DRY SLOT. TNGT...AS HI PRES/COLD DRY AIRMASS IN ONTARIO THIS AFTN RETREAT INTO QUEBEC AND SHRTWV IN THE DESERT SW SHIFTS NEWD INTO THE NRN PLAINS TNGT IN RATHER PROGRESSIVE UPR FLOW...ATTENDANT WARM FNT/CLD BAND TO THE SW WL CLOSE IN ON UPR MI. THE COMBINATION OF VIGOROUS ISENTROPIC ASCENT/MID LVL MOISTENING ACCOMPANYING STRENGHTENING SSW FLOW/H925 WINDS INCRSG TO 50KTS...INCRSG H4-2 DVGC...AND H85-7 FGEN WL ALLOW FOR PCPN TO BREAK OUT W-E TOWARD ERY ARND 12Z DESPITE LINGERING LLVL DRY AIR. SINCE THE MID LVLS MOISTEN AND DYNAMICS ARRIVE BEFORE THE LLVLS WARM/MOISTEN...FCST SDNGS INDICATE A GOOD POTENTIAL FOR FZRA/SLEET WITH WBLB TEMPS AS LO AS -5C TO -7C IN THE SUB H85 LYR UNDER THE FGEN PCPN BAND. USED A NON DIURNAL TOOL FOR TEMPS WITH MIN READINGS RELATIVELY EARLY...THEN TEMPS RISING LATER WITH INCRSG WIND/WAD. EVAPORATE COOLING NEAR THE SFC WL TEND TO SLOW THE RISE IN AREAS EXPERIENCING PCPN. INCLUDED MENTION OF TS W OF THE AXIS OF MAX FGEN WITH H8-5 LAPSE RATES NEAR MOIST ADIABATIC ENHANCED BY THE WAD/VIGOROUS DYNAMICS. TUE...SHRTWV/OCCLUDED LO ARE FCST TO MOVE TO JUST NW OF THUNDER BAY ONTARIO BY 00Z WED...WITH ACCOMPANYING DRY SLOT ON ITS SE FLANK IMPACTING THE CWA. AFT AREA OF DEEPER MSTR/WAD/H85-7 FGEN/H4-2 DVGC EXIT THE E BY 18Z...ANY LINGERING PCPN SHOULD BE NOTHING MORE THAN ISOLD/SCT -SHRA AS FCST SDNGS SHOW QUITE A BIT OF MID LVL DRYING/ CAPPING DVLPG AFT THE EXIT OF THE DEEPER MSTR/DYNAMICS. GUSTY WINDS WL DVLP WITH LLVL WARMING/DESTABILIZATION MIXING OUT THE HIER MOMENTUM ABV INITIAL SHARP INVRN. BEST CHC FOR CLRG WL BE OVER THE FAR W FM IWD-ONTONAGON WITH DOWNSLOPING S WIND. MIXING TO H85 ON NAM/GFS FCST SDNGS INDICATE MAX TEMPS MAY REACH 60 IN THIS AREA. LOCATIONS DOWNWIND OF LK MI WL BE MUCH COOLER WITH FLOW OFF CHILLY WATERS MAINTAINING HIER STABILITY/TEMPS TOWARD THE LOWER END OF GUIDANCE. AS FOR HEADLINES...SUSPECT MODEL QPF THAT WOULD INDICATE NEED FOR AN ICE STORM WARNING IS A BIT TOO HI CONSIDERING THE STEADY EWD MOVEMENT FCST OF THE FGEN/UPR DVGC CORE AND LINGERING LLVL DRY AIR...SO ADVY SHOULD COVER THE FRZG PCPN POTENTIAL WITH ANY ICE ACCUMULATION NOT LIKELY TO EXCEED ABOUT 0.10 INCH. RECENT WARM SOILS ALSO WL TEND TO LIMIT ICE ACCUM POTENTIAL. TWEAKED THE TIMING OF THE HEADLINE A BIT TO ACCOUNT FOR SLOWER ARRIVAL OF PCPN INTO THE CENTRAL COUNTIES. ALSO EXPANDED THE FZRA HEADLINE TO THE E EXCEPT FOR MNM COUNTY...WHICH WL BE FARTHEST S OF THE SHARPER DYNAMICS AND PROBABLY SEE LESS PCPN/ICING. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 417 PM EDT MON MAR 26 2012 995MB LOW LOCATED OVER THE ARROWHEAD OF MN AT 00Z AND WILL SLIDE E ACROSS LK SUPERIOR ON TUES NIGHT. BULK OF INITIAL PCPN WILL HAVE EXITED THE CWA AT THE START OF THE LONG TERM PERIOD. MAIN AREA OF PCPN THROUGH THE NIGHT WILL BE LOCATED ALONG THE WARM FRONT OVER NE LK SUPERIOR...BUT WRAP AROUND SHOWERS WILL AFFECT THE NRN HALF OF UPPER MI THROUGH A GOOD PORTION OF THE NIGHT. EXPECT THE PCPN TO FALL AS RAIN...DUE TO THE LOW LLVL WARM AIR SURGING N THROUGH THE NIGHT AHEAD OF THE COLD FRONT. AS COLD AIR ARRIVES OVER THE WEST COULD SEE THE RAIN MIXING WITH SNOW OVER THE FAR WEST NEAR DAYBREAK. WITH THE LLVL WARM AIR AHEAD OF THE FRONT...FOLLOWED A NON-DIURNAL TEMP CURVE ON TUES NIGHT. TEMPS WILL BE WARMER OVER PORTIONS OF THE CENTRAL/ERN CWA TUESDAY NIGHT THAN DURING THE DAY TUESDAY...VALUES REACHING THE MID-UPPER 40S. COLD FRONT WILL SLIDE THROUGH THE AREA ON WED MORNING AND LEAD TO FALLING H850 TEMPS AND WINDS SHIFTING TO THE NNW. WITH H850 TEMPS FALLING FROM 1-2C AT 12Z WED TO -4 TO -6C BY 00Z THURS SHOULD SEE LK ENHANCED SHOWERS THROUGH A GOOD PORTION OF THE DAY...ESPECIALLY WITH THE DEEPER MOISTURE PRESENT DURING THE MORNING HOURS. HAVE PEAKED THE POPS OVER THE WEST DURING THAT TIME FRAME...THEN DIMINISHED THROUGH THE DAY AS DRY AIR STARTS TO ERRODE THE PCPN FROM THE NW. PCPN TYPE IS THE MAIN CONCERN FOR WED. NAM SHOWING CLOUD TOP IS AROUND -8 TO -10C SO PCPN START AS SNOW IN THE CLOUDS...BUT GFS IS WARMER WITH CLOUD TOP TEMPS AROUND -5C AND MAINLY RAIN. HAVE FOLLOWED A LITTLE COOLER TEMPERATURES AND A THE PCPN STARTING AT SNOW. THE LLVL WARM LAYER WILL BE THE MAIN PCPN TYPE FACTOR...AS IT WILL TRY TO MELT THE PCPN BEFORE IT HITS THE SFC. USED A COMBINATION OF SFC TEMPS AND WETBULB ZERO HEIGHTS FOR RAIN/SNOW POTENTIAL ON WED...WITH THE HIGHER TERRAIN SEEING THE SNOW FIRST AND THEN SPREADING ACROSS THE AREA FROM N TO S THROUGH THE AFTN AND EARLY EVENING BUT OVERALL PCPN SHOULD BE DIMINISHING THEN. NON DIURNAL TEMP CURVE AGAIN ON WED...HIGHS IN THE MORNING AND EARLY AFTN THEN FALLING. LK ENHANCED SHOWERS WILL BE DIMINISHING FROM W TO E IN THE AFTN/EVENING...AS DRIER AIR AND ANTICYCLONIC FLOW ARRIVE WITH THE HIGH PRESSURE RIDGE. BUT H900 MOISTURE ONCE AGAIN LOOKS TO LINGER OVER THE AREA WED NIGHT INTO THURS MORNING. WITH H900 TEMPS AROUND -6.5C...SHOULD SEE SUFFICIENT LK INSTABILITY TO KEEP CLOUDS GOING AS WINDS VEER TO THE NE ON WED NIGHT INTO THURS MORNING. WILL TRY TO HOLD ONTO THE CLOUDS LONGER THAN THE MODELS ARE SHOWING...AS THEY HAD A DIFFICULT TIME WITH THE SIMILAR FEATURE YESTERDAY. ONCE THE LLVL MOISTURE DEPARTS OR IS MIXED OUT THURS MORNING...LOOKS TO BE A NICE DAY ON THURS WITH THE AREA UNDER THE HIGH PRESSURE RIDGE. COULD SEE THURS BEING VERY SIMILAR TO TODAY...WITH HUDSON BAY HIGH PRESSURE RIDGE OVER THE AREA AND TRYING TO PULL DRIER AIR INTO THE ERN CWA. WILL LOWER DEWPOINT VALUES 5-7 DEGREES FROM THE GOING MID 20S OVER THE EAST...AS MODEL MIXED TD VALUES INDICATE SINGLE DIGIT VALUES. MAY NEED TO DROP FURTHER IF TREND CONTINUES. EXTENDED /THURSDAY NIGHT THROUGH MONDAY/... SHORTWAVE APPROACHES THE AREA ON FRI...TRYING TO PUSH THROUGH THE UPPER RIDGE. 00-12Z GEM/GFS/ECMWF DIFFERING ON THE THIS SHORTWAVE AND ASSOCIATED SFC FEATURES...SO HAVE CHANCES MOVING INTO THE WRN CWA IN THE MORNING AND THEN EXPECT A DIMINISHING TREND AS THE SHORTWAVE WEAKENS WHILE HEADING E IN THE AFTN. WEAK UPPER AND SFC RIDGING PUSHES IN FOR FRI NIGHT AND SHOULD LEAD TO A DRY PERIOD...BEFORE NEXT WAVE APPROACHES FOR THE WEEKEND. 00-12Z ECMWF/GEM/GFS/UKMET RUNS VARY CONSIDERABLY WITH THIS WAVE...IN TIMING/LOCATION/STRENGTH. CONSENSUS IDEA IS THAT IT WILL PUSH ALONG THE US/CANADA BORDER IN THE NRN PLAINS ON FRI NIGHT...THEN SLIDE JUST N OF LK SUPERIOR ON SAT. THIS SHOULD KEEP MUCH OF THE PCPN TO THE N OF THE AREA...BUT THE GEM IS THE FARTHEST S AND STRONGER WITH THE LOW CENTER AND PUSHES IT ACROSS THE CWA. THIS WAVE WILL SLIDE E ON SAT NIGHT...LEADING TO WEAK RIDGING AGAIN ON SUN AND SUN NIGHT BEFORE NEXT WAVE SLIDES IN ON MON. OUT OF THE THREE WAVES IN THE EXTENDED...THE MONDAY FEATURE LOOKS TO BE THE MOST POTENT AND AFFECTING MUCH OF THE NCNTRL U.S. WILL MENTION CHANCES ON MON TO ACCOUNT FOR THIS. EXTENDED PERIOD LOOKS TO SEE ABOVE NORMAL TEMPERATURES...WITH GRADUAL WARMING HEADING THROUGH THE WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 123 PM EDT MON MAR 26 2012 EXPECT VFR CONDITIONS THRU AT LEAST THIS EVNG AS VERY DRY AIRMASS ASSOCIATED WITH HI PRES IN ONTARIO DOMINATES. THICKER MID CLDS/SOME MIXED PCPN IN ADVANCE OF A WARM FRONT WL ARRIVE TNGT...BUT LINGERING LLVL DRY AIR WL LIMIT THE POTENTIAL FOR LOWER CIG/VSBY. THIS LLVL DRY AIR WL LIKELY CAUSE SOME -FZRA...ESPECIALLY AT SAW WHERE UPSLOPE SSE WIND WL MAINTAIN LOWER TEMPS LONGER. AS THE LLVL S WIND INTENSIFIES TNGT AHEAD OF THE APRCHG WARM FNT...LLWS IS LIKELY TO IMPACT ALL 3 TAF SITES. THESE WINDS ARE LIKELY TO MIX TO THE SFC ON TUE FOLLOWING SOME LLVL WARMING/DESTABILIZATION. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 417 PM EDT MON MAR 26 2012 AS THE PRESSURE GRADIENT STRENGTHENS OVER THE UPPER GREAT LAKES BETWEEN A DEEPENING LO PRES SYSTEM MOVING E FROM THE NORTHERN PLAINS AND RETREATING HI PRES IN SE CANADA...EXPECT INCREASING SSE WINDS TO REACH GALE FORCE AND UP TO 40 KTS ON TUE OVER THE E HALF OF LAKE SUPERIOR FAVORED FOR STRONGER S WINDS DESPITE HI STABILITY OVER THE RELATIVELY CHILLY LAKE WATERS. AS THE LOW MOVES ACROSS LAKE SUPERIOR ON TUES NIGHT AND EXITS TO THE E ON WED...WIND WILL SHIFT TO THE NW AND GUST TO 30KTS TUES NIGHT. MARINE LAYER WILL LIKELY KEEP THE HIGHER WINDS ALOFT FROM REACHING THE SFC...SO DON/T THINK WE WILL SEE ANY GALES. HIGH PRESSURE RIDGE BUILDING IN WED AFTN AND NIGHT WILL DIMINISH THE WINDS BELOW 20KTS WITH WINDS GRADUALLY VEERING THROUGH THURS. A WEAK DISTURBANCE WILL PUSH ACROSS THE AREA ON FRI...BUT THE ESE WINDS SHOULD STAY BELOW 20KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... FREEZING RAIN ADVISORY FROM 2 AM EDT /1 AM CDT/ TO 11 AM EDT /10 AM CDT/ TUESDAY FOR MIZ004-005-010-011-084. FREEZING RAIN ADVISORY FROM 5 AM TO NOON EDT TUESDAY FOR MIZ006- 007-013-014-085. FREEZING RAIN ADVISORY FROM 11 PM EDT /10 PM CDT/ THIS EVENING TO 8 AM EDT /7 AM CDT/ TUESDAY FOR MIZ002-009. LAKE SUPERIOR... GALE WARNING FROM 10 AM TO 7 PM EDT TUESDAY FOR LSZ267. GALE WARNING FROM 7 AM TO 8 PM EDT TUESDAY FOR LSZ266. GALE WARNING FROM 8 AM TO 6 PM EDT TUESDAY FOR LSZ244-245-248- 249-264-265. GALE WARNING FROM 10 AM TO 6 PM EDT TUESDAY FOR LSZ250-251. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...KC SHORT TERM...KC LONG TERM...SRF AVIATION...KC MARINE...KC/SRF
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
330 PM CDT MON MAR 26 2012 .DISCUSSION.. WATER VAPOR IMAGERY THIS AFTERNOON SHOWING FEATURE OF INTEREST... SHORTWAVE TROF...CROSSING THE ROCKIES. MODELS IN QUITE GOOD AGREEMENT THIS WAVE WILL LIFT QUICKLY ACROSS THE NORTHERN PLAINS AND NEAR THE WESTERN GREAT LAKES REGION BY TUESDAY AFTERNOON. ATTENDANT SFC LOW CURRENTLY OVER NRN WY WILL DEEPEN SIGNIFICANTLY THROUGH TONIGHT AS 500MB HEIGHT FALLS DROP 16DAM. INCOMING FRONT WITH THIS SYSTEM WILL BE THE FOCUS FOR POSSIBLE THUNDER SOMETIME AFTER 06Z. HIRES WRF AND RUC13 ARE ADVERTISING MODERATE INSTABILITY ALONG WITH DECENT MOISTURE POOLING ALONG THE BNDRY/SFC TROF WITH BEST CHANCE FOR DEVELOPMENT MAINLY SOUTH OF I-80. ON TUESDAY TIGHT SURFACE PRESSURE GRADIENT SHOULD PREVAIL OVER MOST OF THE REGION... PARTICULARLY NORTH. FIRE WEATHER ISSUE COMING TO PLAY THEN TUESDAY AFTERNOON AS COMBINATION OF WIND AND MIXING DRIVES DEW POINTS/RH DOWN CLOSE TO RED FLAG WARNING CRITERIA. FOCUS FOR THUNDER THEN SHIFTS TO THE SOUTH WEDNESDAY/WEDNESDAY NIGHT AS BOUNDARY LAYER MOISTURE CONVERGENCE INCREASES/INSTABILITY AXIS SETS UP ALONG THE NEB/KS BORDER...THEN RE-ORIENTS THURSDAY/THURSDAY NIGHT OVER THE CWA. AS FOR DAY 4-7...AT THIS POINT NOT INCLINED TO MAKE ANY SIGNIFICANT CHANGES TO THE FORECAST DUE TO SIGNIFICANT GFS/ECM DIFFERENCES PER LATEST RUN. OTHERWISE STILL LOOKING LIKE MAX TEMPS WILL BE HOVERING AROUND 20 DEG ABOVE NORM HEADING INTO NEXT WEEKEND. DEE && .AVIATION... 18Z TAFS FOR KOMA...KLNK...AND KOFK. MAIN CONCERNS THROUGH THE PERIOD WILL BE WINDS. INITIALLY...WINDS FROM THE SOUTHEAST AROUND 150-170 DEGREES SUSTAINED AT 25 TO 28KTS... WITH GUSTS UP TO 35 TO 38KTS. SHOULD LOSE THE GUSTS AT KLNK/KOMA BY ABOUT 27/00Z. A FRONT MOVING INTO THE AREA WILL ALSO BRING A WIND SHIFT...ALONG WITH A SMALL CHANCE FOR CONVECTION LATER TONIGHT AS WELL. BEST CHANCE APPEARS TO BE AT KLNK/KOMA...IN THE 07Z-11Z PERIOD. WINDS BECOME WEST AFTER THE TROUGH MOVES THROUGH...BECOMING GUSTY AGAIN BY 27/15Z. DEWALD .OAX WATCHES/WARNINGS/ADVISORIES... NE...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR NEZ045-052-053-066-067-078-088-089. WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NEZ015-033-034- 043>045-050>053-065-066-078. RED FLAG WARNING FROM NOON TO 8 PM CDT TUESDAY FOR NEZ011-012- 015>018-030>034-042>044-050-051-065. WIND ADVISORY UNTIL 10 PM CDT THIS EVENING FOR NEZ011-012- 016>018-030>032-042. IA...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR IAZ055-056-069. WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR IAZ043-055. RED FLAG WARNING FROM NOON TO 8 PM CDT TUESDAY FOR IAZ043. && $$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1215 PM CDT MON MAR 26 2012 .AVIATION...18Z TAFS FOR KOMA...KLNK AND KOFK. MAIN CONCERNS THROUGH THE PERIOD WILL BE WINDS. INITIALLY...WINDS FROM THE SOUTHEAST AROUND 150-170 DEGREES SUSTAINED AT 25 TO 28KTS...WITH GUSTS UP TO 35 TO 38KTS. SHOULD LOSE THE GUSTS AT KLNK/KOMA BY ABOUT 27/00Z. A FRONT MOVING INTO THE AREA WILL ALSO BRING A WIND SHIFT...ALONG WITH A SMALL CHANCE FOR CONVECTION LATER TONIGHT AS WELL. BEST CHANCE APPEARS TO BE AT KLNK/KOMA...IN THE 07Z-11Z PERIOD. WINDS BECOME WEST AFTER THE TROUGH MOVES THROUGH...BECOMING GUSTY AGAIN BY 27/15Z. DEWALD && .PREV DISCUSSION... /ISSUED 1039 AM CDT MON MAR 26 2012/ DISCUSSION... UPDATED THE FORECAST TO REMOVE CHANCE OF RAIN FOR THE REST OF THE MORNING IN WESTERN IOWA. ALSO EXPANDED THE WIND ADVISORY ONE MORE TIER OF COUNTIES FURTHER EAST...INTO THE LINCOLN AND OMAHA METRO AREAS AS THESE LOCATIONS SHOULD BE JUST ON THE EDGE OF THE ADVISORY LEVEL WIND SPEEDS. DEWALD PREV DISCUSSION... /ISSUED 754 AM CDT MON MAR 26 2012/ DISCUSSION... HAVE INCREASED POPS ALONG AND EAST OF THE MISSOURI RIVER...AS SHOWERS FINALLY HAVE DEVELOPED IN A BAND FROM AROUND BLAIR TO PLATTSMOUTH TO NEBRASKA CITY. SO FAR...NO LIGHTNING HAS BEEN DETECTED...BUT STILL THINK A FEW STRIKES ARE POSSIBLE...AND KEPT ISOLATED WORDING IN THE GRIDS. MAYES PREV DISCUSSION... /ISSUED 646 AM CDT MON MAR 26 2012/ DISCUSSION... MAIN CONCERN OVER THE NEXT 30 HOURS IS THE POTENT UPPER LEVEL TROUGH CURRENTLY OVER THE GREAT BASIN. THIS IS PROGGED TO TAKE A TRACK NEWD TODAY AND MOVE THROUGH THE NORTHERN PLAINS TONIGHT AND TUE. AHEAD OF THE STRONG SYSTEM LOW LEVEL WAA IS CURRENTLY TAKING PLACE ACROSS THE REGION. MODELS SEEM TO HAVE A HIGH BIAS WITH THE MOISTURE ATTM...AND THUS A LITTLE BULLISH ON THE CONVECTIVE POTENTIAL FOR THE REST OF THE NIGHT. LATEST RUC ANALYSIS DOES INDC AROUND 500-1000 J/KG OF MUCAPE OVER THE WRN CWA...BUT POINT FORECAST SOUNDINGS INDC THIS MOISTURE IS RATHER SHALLOW AROUND 850 MB AND THERE IS A GOOD DEAL OF CIN HOLDING BACK THE CONVECTION. WE FEEL THIS TREND WILL CONT TONIGHT...BUT WILL MAINTAIN A SLIGHT CHANCE POPS B/W 12-15Z OVER THE CNTRL AND SERN CWA FOR ANYTHING ISO THAT MAY DEVELOP. OTHERWISE ANOTHER WINDY AND WARM DAY IS IN STORE FOR THE FA. WINDS AT 925 (850) MB INCREASE TO 40 (55) KT BY THIS AFTERNOON AND WITH THE INCREASING PRESSURE GRADIENT...SOME OF THIS SHOULD MAKE IT TO NEAR THE SURFACE. HIGH CLOUDS WILL LIKELY LIMIT MIXING THOUGH...AND WE WOULD FEEL BETTER WITH A DUE SOUTH OR SW WIND...SO A WIND ADVRY IS NO SLAM DUNK...BUT WITH THE PRESSURE GRADIENT AND MIXING TO 925 MB WE WILL LIKELY SEE A FEW SITES MEET CRITERIA THIS AFTN INTO THE EVNG HOURS. THUS WE HAVE ISSUED A WIND ADVISORY. THE DRY LINE STILL LOOKS TO SET UP OVER THE WRN HI PLAINS TODAY AS THE UPPER LEVEL SYSTEM MOVES TOWARD THE REGION. SOME POSITIVE CAPE IS INDICATED NEAR THE DRY LINE...BUT CIN IS SIGNIFICANT AND WITH MUCH OF THE FORCING GOING INTO SODAK...CONVECTIVE POTENTIAL FOR THE NEB AREA LOOKS PRETTY LOW...AND ESPECIALLY ANYTHING THAT WOULD WORK INTO OUR FA. THUS HAVE REDUCED POPS TO SCHC FOR THIS EVNG IN THE NW. A LITTLE BETTER CHC OF SHOWERS/STORMS MAY ACTUALLY COME AFTER MIDNIGHT IN THE ERN FA AS BETTER MOISTURE INTERACTS WITH THE ADVANCING PAC CDFNT AS IT MOVES THROUGH THE AREA. WILL CONT SOME CHC POPS IN THE E AFTER MIDNIGHT FOR THIS. THE SYSTEM SHOULD BE CLEAR OF THE FA BY TUES MRNG WITH ANOTHER WARM AND DRY DAY EXPECTED FOR TUE/WED. THE SURFACE FNT STILL LOOKS TO HANG UP OVER MO/KS ON TUE/WED AND THIS WILL START TO RETREAT NWD WED NIGHT AND INTO THE DAY ON THU (ALTHOUGH I HAVE MY DOUBTS THAT IT WILL ACTUALLY MAKE IT INTO NEB). AS THE LOW LEVEL WAA INCREASES AHEAD OF A SHRTWV PROGGED FOR THU NIGHT SOME MOISTURE WILL LIKELY WORK AROUND THE FNT AND INTO CNTRL NEB BY LATE THU WHICH SHOULD ALLOW FOR A CHANCE OF SHOWERS/STORMS LATE THU...THU NIGHT AND INTO FRI. SIGNIFICANT DIFFERENCES THEN DEVELOP BETWEEN THE GFS AND EC FOR NEXT WEEKEND AND NO CHANGES WERE MADE PAST FRI. BOUSTEAD FIRE WEATHER... IN THE POST FRONT AIRMASS ON TUES THE AIR MASS IS EXPECTED TO DRY OUT SIGNIFICANTLY. DEEP MIXING TO AROUND 850 MB OR HIGHER WILL LEAD TO DEWPOINTS FALLING THROUGH A GOOD PART OF THE DAY IN THE CNTRL AND WRN CWA. DESPITE THE FRONT MOVING THROUGH...TEMPERATURES WITH THE MIXING ON TUES WILL LIKELY CLIMB BACK INTO THE MID AND EVEN SOME UPPER 70S. THIS WILL CREATE SEVERAL HOURS OF RH BELOW 20 PERCENT DURING THE AFTN ON TUES. WITH STRONGLY UNIDIRECTIONAL FLOW AND A DECENT PRESSURE GRADIENT ON THE SOUTH SIDE OF THE SURFACE LOW OVER SD...SFC WINDS SHOULD BE SUSTAINED ABOVE 15 KT WITH GUSTS WELL OVER 25 KT. THIS ALL SHOULD COMBINED FOR A DANGEROUS FIRE WX DAY...ALTHOUGH WE ARE STARTING TO GREEN UP NICELY AROUND THE AREA...AND THUS HAVE ISSUED A FIRE WEATHER WATCH FOR TUES FOR A LARGE PART OF THE AREA. BOUSTEAD/MAYES && .OAX WATCHES/WARNINGS/ADVISORIES... NE...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR NEZ011-012-015>018-030>034-042>045-050>053- 065>067-078-088-089. WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NEZ015-033-034- 043>045-050>053-065-066-078. WIND ADVISORY UNTIL 10 PM CDT THIS EVENING FOR NEZ011-012- 016>018-030>032-042. IA...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR IAZ043-055. WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR IAZ043-055. && $$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
653 PM EDT MON MAR 26 2012 .SYNOPSIS... SURFACE HIGH PRESSURE NEAR HUDSON BAY WILL BUILD INTO THE NORTH COUNTRY THROUGH TUESDAY. THIS WILL RESULT IN MAINLY CLEAR SKIES TONIGHT WITH CHILLY TEMPERATURES. ON TUESDAY...PLENTY OF SUNSHINE IS ANTICIPATED WITH TEMPERATURES IN THE 30S TO NEAR 40...ALONG WITH NORTHWEST WINDS OF 10 TO 20 MPH. A WARM FRONT WILL PRODUCE INCREASING CLOUDS WITH SCATTERED RAIN AND SNOW SHOWERS BY WEDNESDAY MORNING. && .NEAR TERM /UNTIL 8 AM TUESDAY MORNING/... AS OF 653 PM EDT MONDAY...PREVIOUS FORECAST STILL IN GOOD SHAPE. HAVE UPDATED THE GRIDS WITH THE LATEST SURFACE OBSERVATIONS. VISIBLE SATELLITE LOOP AND SURFACE OBSERVATIONS SHOWING CLEAR SKIES ACROSS NORTHERN NEW YORK AND THE CHAMPLAIN VALLEY...WITH LOW CLOUDS LINGERING ACROSS EASTERN VERMONT. EXPECTING THE CLOUDS ACROSS EASTERN VERMONT TO BEGIN TO DISSIPATE AFTER SUNSET WITH THE LOSS OF DAYTIME SURFACE HEATING...AND WITH DRIER AIR CONTINUING TO MOVE INTO THE REGION OVERNIGHT AS DEW POINTS WILL CONTINUE TO FALL OVERNIGHT. EXPECTING GUSTY NORTHWEST WINDS TO STAY UP OVERNIGHT AS WELL...AS TIGHT SURFACE PRESSURE GRADIENT REMAINS OVER THE REGION. PREVIOUS DISCUSSION FROM 345 PM EDT MONDAY...BIG PICTURE SHOWS DEEP MID/UPPER LVL TROF ACRS THE NE CONUS WITH RIBBON OF SUBSIDENCE/DRY AIR ALOFT BUILDING INTO OUR REGION. MEANWHILE...SFC ANALYSIS SHOWS 1032MB HIGH PRES BUILDING INTO OUR CWA....WITH SFC DWPTS IN THE SINGLE DIGITS ABOVE/BLW ZERO THIS AFTN. THIS AIRMASS WL BE ACRS OUR FA ON TUES...ALONG WITH PLENTY OF SUNSHINE. FCST CHALLENGE TONIGHT WL BE TEMPS...FOLLOWED BY DWPTS/RH PARAMETERS ON TUES...ALONG WITH SFC WINDS. UPSTREAM MINS LAST NIGHT SHOW MANY TEMPS IN THE SINGLE DIGITS WITH A FEW BLW ZERO READINGS SOUTH OF HUDSON BAY...ASSOCIATED WITH 925MB TEMPS -20C. GIVEN SOME GRADIENT ACRS OUR CWA....LIMITED SNOW PACK...AND SLIGHTLY WARMER 925MB TEMPS...WL MENTION LOWS FROM 0F AT SLK/MTNS TO 5 TO 10F CENTRAL/NORTHERN VT TO 10 TO 15F CPV/SLV. RUC13 AND NAM12 RH PROFILES STILL SHOW SOME 975MB TO 800MB RH ACRS THE NEK/NORTHERN VT MTNS THRU 03Z...THEREFORE WL TRY TO SHOW SOME CLOUDS...BUT OTHERWISE MAINLY CLR SKIES TONIGHT...WITH NW WINDS OF 10 TO 20 WITH GUSTS TO 30 MPH UNTIL MTN...DECREASING TO 5 TO 15 MPH WITH GUSTS TO 20 MPH TWD MORNING. TUESDAY...SFC HIGH PRES CENTERED OVER THE OTTAWA VALLEY AT 12Z WL SHIFT INTO NORTHERN NY BY 15Z AND INTO THE CPV BY 18Z TUES...WITH A WEAKENING PRES GRADIENT. SOUNDINGS SHOW MIXED LAYER WINDS BTWN 15 AND 25 MPH THRU NOON...ESPECIALLY CENTRAL/EASTERN VT...BUT DECREASING AS GRADIENT SLACKENS DURING THE AFTN HRS TO 5 TO 15 MPH. AT VSF...SOUNDING SHOWS MIXED LAYER WINDS OF 25 TO 30 KNTS...THRU 16Z...HELPING TO PRODUCE SFC WIND GUSTS TO 30 MPH...DURING THE MORNING HRS. SOUNDINGS SHOW GOOD MIXING TO 900MB ON TUES AFTN...WHICH WL TRANSFER SOME VERY DRY AIR TO THE SFC. UPSTREAM OBS UNDER SFC HIGH PRES SHOWS DWPTS BTWN -9F AND +5F...COMBINED WITH ANTICIPATED HIGHS IN THE 30S ON TUES...RESULTS IN MIN RH VALUES BTWN 10% AND 18%...WITH LOWEST VALUES ACRS THE SLV/NORTHERN NY ZNS ON TUES AFTN. GIVEN DEEP DRY LAYER...EXPECT PLENTY OF SUNSHINE WITH TEMPS 5 TO 10 DEGREES BLW NORMAL. && .SHORT TERM /8 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 345 PM EDT MONDAY...PROGRESSIVE MID/UPPER LVL PATTERN WL DEVELOP ACRS THE NE CONUS...WITH CHANGEABLE WX ANTICIPATED. ON TUES NIGHT...COMBINATION OF RETURN SOUTHERLY FLW AND DEVELOPING TIGHT SW TO NE THERMAL GRADIENT WL MAKE FOR A DIFFICULT LOW TEMP FCST. GIVEN...VERY DRY AIR IN PLACE AND SFC DWPTS IN THE SINGLE DIGITS...FEEL TEMPS WL QUICKLY DROP IN THE EARLY HRS...THEN INCREASE AFT MIDNIGHT AS WINDS/CLOUDS INCREASE. THINKING LOWS WL RANGE FROM 5 TO 10F NEK TO 20 TO 25F SLV/CPV. GFS/NAM ARE HANDLING MOISTURE/LIFT PROFILES ASSOCIATED WITH WAA DIFFERENTLY AND THE ACCOMPANYING QPF. NAM IS MUCH MORE AGGRESSIVE WITH QPF FIELDS ACRS OUR CENTRAL/NORTHERN CWA...WITH AMOUNTS NEAR 0.25"...WHILE GFS IS A TRACK TO 0.10". GIVEN...VERY DRY AIRMASS IN PLACE AHEAD OF 5H VORT AND WAA LIFT...AND DEVELOPING SOUTHERLY FLW...WL TREND TWD THE DRIER GFS SOLUTION. WL MENTION CHC POPS TO LOW LIKELY POPS ACRS NNY INTO NORTHERN VT MTNS AFT 06Z WEDS...WITH SOME LIGHT SNOW ACCUMULATION POSSIBLE (TRACE TO 1"). INITIALLY THERMAL PROFILES SUPPORT ALL SNOW...AS 1000 TO 500MB THICKNESS VALUES ARE BLW 540 AND PROGGED 85H TEMPS ARE BTWN -2C AND -4C. BEST 850 TO 500MB RH AND 700 TO 500MB OMEGA LIFTS FROM SW TO NW ACRS OUR CWA BTWN 06Z AND 15Z WEDS. AFTER 15Z...BEST MOISTURE/LIFT IS ACRS OUR EXTREME NORTHERN ZNS...AS WARM ADVECTS INTO OUR CWA. LOCAL 4KM AND NAM SHOWS SOME LLVL DAMMING OF COLD AIR...ESPECIALLY NEK AND EXTREME NORTHERN SLV ON WEDS...CREATING A VERY TIGHT THERMAL GRADIENT. WITH CLRING SKIES PARTS OF THE SLV FROM GOUVERNEUR TO POTSDAM/CANTON WL WARM INTO THE L60S...WHILE NEAR MSS COULD STRUGGLE TO REACH 50F. ELSEWHERE...GIVEN SHARP 925MB THERMAL GRADIENT ACRS OUR CWA...TEMPS WL BE TRICKY...WL MENTION L/M50S CPV TO L/M40S NEK/MTNS OF VT. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 354 PM EDT MONDAY...GFS/ECMWF IN FAIRLY GOOD AGREEMENT ON THE OVERALL PATTERN FOR THURSDAY AND FRIDAY...WITH INCREASING DISAGREEMENT BEYOND FRIDAY. TEMPERATURES THROUGH THE EXTENDED ARE CLOSE TO NORMAL THROUGH FRIDAY...TRENDING ABOVE NORMAL BY THE WEEKEND. SYSTEM EXPECTED TO IMPACT THE REGION ON WEDNESDAY BEGINS TO EXIT NEW ENGLAND THURSDAY. MAINTAINED CHANCE PRECIPITATION PROBABILITIES FOR THURSDAY AFTERNOON...THOUGH HAVE GONE WITH SLIGHT CHANCE PRECIPITATION PROBABILITIES FOR THURSDAY AFTERNOON/EVENING ALONG EASTERN-FACING SLOPES WHERE UPSLOPE SHOWERS MAY CONTINUE TO LINGER. NORTHERLY FLOW THURSDAY NIGHT ALLOWS 850MB TEMPERATURES TO FALL INTO THE -8 TO -10C RANGE. HIGHS ON THURSDAY REACH INTO THE 40S WITH LOWS IN THE 20S TO AROUND 30 IN THE CHAMPLAIN AND SAINT LAWRENCE VALLEYS. WEAK HIGH PRESSURE THEN BUILDS IN FOR FRIDAY WITH TEMPERATURES A COUPLE OF DEGREES COOLER THAN THURSDAY. FOR THE WEEKEND...DIFFERENCES EMERGE IN TIMING REGARDING A DEVELOPING LOW PRESSURE SYSTEM MOVING IN FROM THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION. 12Z GFS TRACKS THE LOW FURTHER TO THE NORTH ON SATURDAY THAN THE 12Z ECMWF...AND IS ALSO MORE PROGRESSIVE THAN THE 12Z ECMWF. DIVERGENT SOLUTIONS CONTINUE INTO EARLY NEXT WEEK. HAVE OPTED TO NOT STRAY TOO FAR FROM CONTINUITY...SO HAVE KEPT MODERATING TEMPERATURES AND SLIGHT CHANCE PRECIPITATION PROBABILITIES GOING THROUGH THE REST OF THE EXTENDED. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... THROUGH 12Z TUESDAY...GUSTY NORTHWEST WINDS WILL CONTINUE THROUGH 00Z WITH GUSTS TO 30 KNOTS EXPECTED...THEN TAPER OFF AND BE SUSTAINED IN THE 10 TO 20 KNOT RANGE. VFR CEILINGS EXIST THROUGH 00Z WITH JUST A FEW FLURRIES...BUT CLOUDS WILL QUICKLY DISSIPATE AROUND SUNSET. VFR CONDITIONS WILL EXIST THROUGH THE REMAINDER OF THE PERIOD. OUTLOOK 18Z TUESDAY THROUGH FRIDAY...VFR/MOSTLY CLR CONDITIONS TUESDAY WITH NW WINDS 10-20 MPH. LOW PRESSURE SYSTEM APPROACHING FROM THE GREAT LAKES REGION BRINGS A CHANCE OF LIGHT RAIN WEDNESDAY...WITH RAIN OR SNOW SHOWERS WEDNESDAY NIGHT INTO THURSDAY MORNING. PERIODS OF MVFR CONDITIONS WILL PREVAIL...WITH BRIEF IFR INTERVALS POSSIBLE. RIDGE OF SFC HIGH PRESSURE SHIFTING EWD FROM THE GREAT LAKES FOR FRIDAY SHOULD BRING LIGHT N-NW WINDS AND A RETURN TO DRIER/VFR CONDITIONS. && .FIRE WEATHER... AS OF 345 PM EDT MONDAY...CONDITIONS CONTINUE TO REMAIN FAVORABLE ON TUESDAY FOR POTENTIAL FIRE WEATHER CONCERNS. TEMPERATURES WILL START OUT COLD...BUT HUMIDITY RECOVERIES OVERNIGHT TONIGHT WILL BE FAIR. MIXING DEVELOPS EARLY AND WITH THE DRIEST PORTION OF THE CANADIAN HIGH MOVING DOWN OVER US...THE IDEA OF SHARPLY FALLING HUMIDITIES LATE MORNING AND AFTERNOON IS A GOOD BET. THIS WILL RESULT IN AFTERNOON RELATIVE HUMIDITIES FALLING INTO THE 12 TO 18 PERCENT RANGE. AS MENTIONED EARLIER...PRESSURE GRADIENT WILL BE STRONGEST IN THE MORNING AND THEN TAPER OFF IN THE AFTERNOON...NEVERTHELESS THE POTENTIAL FOR WIND GUSTS TO 25 MPH WILL EXIST...ESPECIALLY ACROSS VERMONT. FULL SUN WILL HELP DRY THE FINE FUELS...WHICH GOT A REPRIEVE FROM THE LIGHT SNOW/CLOUD COVER ON MONDAY. FORESTRY PERSONNEL INDICATE ABNORMALLY DRY FUELS OVERALL...THUS THE SITUATION WILL BE EXAMINED CLOSELY FOR POSSIBLY UPGRADE TO A RED FLAG WARNING GIVEN THE EXPECTED WEATHER CONDITIONS. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR VTZ001>012-016>019. NY...FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR NYZ026>031-034-035-087. && $$ SYNOPSIS...TABER NEAR TERM...WGH/TABER SHORT TERM...TABER LONG TERM...LOCONTO AVIATION...BANACOS/EVENSON FIRE WEATHER...EVENSON
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
354 PM EDT MON MAR 26 2012 .SYNOPSIS... SURFACE HIGH PRESSURE NEAR HUDSON BAY WILL BUILD INTO THE NORTH COUNTRY THROUGH TUESDAY. THIS WILL RESULT IN MAINLY CLEAR SKIES TONIGHT WITH CHILLY TEMPERATURES. ON TUESDAY...PLENTY OF SUNSHINE IS ANTICIPATED WITH TEMPERATURES IN THE 30S TO NEAR 40...ALONG WITH NORTHWEST WINDS OF 10 TO 20 MPH. A WARM FRONT WILL PRODUCE INCREASING CLOUDS WITH SCATTERED RAIN AND SNOW SHOWERS BY WEDNESDAY MORNING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 345 PM EDT MONDAY...BIG PICTURE SHOWS DEEP MID/UPPER LVL TROF ACRS THE NE CONUS WITH RIBBON OF SUBSIDENCE/DRY AIR ALOFT BUILDING INTO OUR REGION. MEANWHILE...SFC ANALYSIS SHOWS 1032MB HIGH PRES BUILDING INTO OUR CWA....WITH SFC DWPTS IN THE SINGLE DIGITS ABOVE/BLW ZERO THIS AFTN. THIS AIRMASS WL BE ACRS OUR FA ON TUES...ALONG WITH PLENTY OF SUNSHINE. FCST CHALLENGE TONIGHT WL BE TEMPS...FOLLOWED BY DWPTS/RH PARAMETERS ON TUES...ALONG WITH SFC WINDS. UPSTREAM MINS LAST NIGHT SHOW MANY TEMPS IN THE SINGLE DIGITS WITH A FEW BLW ZERO READINGS SOUTH OF HUDSON BAY...ASSOCIATED WITH 925MB TEMPS -20C. GIVEN SOME GRADIENT ACRS OUR CWA....LIMITED SNOW PACK...AND SLIGHTLY WARMER 925MB TEMPS...WL MENTION LOWS FROM 0F AT SLK/MTNS TO 5 TO 10F CENTRAL/NORTHERN VT TO 10 TO 15F CPV/SLV. RUC13 AND NAM12 RH PROFILES STILL SHOW SOME 975MB TO 800MB RH ACRS THE NEK/NORTHERN VT MTNS THRU 03Z...THEREFORE WL TRY TO SHOW SOME CLOUDS...BUT OTHERWISE MAINLY CLR SKIES TONIGHT...WITH NW WINDS OF 10 TO 20 WITH GUSTS TO 30 MPH UNTIL MTN...DECREASING TO 5 TO 15 MPH WITH GUSTS TO 20 MPH TWD MORNING. TUESDAY...SFC HIGH PRES CENTERED OVER THE OTTAWA VALLEY AT 12Z WL SHIFT INTO NORTHERN NY BY 15Z AND INTO THE CPV BY 18Z TUES...WITH A WEAKENING PRES GRADIENT. SOUNDINGS SHOW MIXED LAYER WINDS BTWN 15 AND 25 MPH THRU NOON...ESPECIALLY CENTRAL/EASTERN VT...BUT DECREASING AS GRADIENT SLACKENS DURING THE AFTN HRS TO 5 TO 15 MPH. AT VSF...SOUNDING SHOWS MIXED LAYER WINDS OF 25 TO 30 KNTS...THRU 16Z...HELPING TO PRODUCE SFC WIND GUSTS TO 30 MPH...DURING THE MORNING HRS. SOUNDINGS SHOW GOOD MIXING TO 900MB ON TUES AFTN...WHICH WL TRANSFER SOME VERY DRY AIR TO THE SFC. UPSTREAM OBS UNDER SFC HIGH PRES SHOWS DWPTS BTWN -9F AND +5F...COMBINED WITH ANTICIPATED HIGHS IN THE 30S ON TUES...RESULTS IN MIN RH VALUES BTWN 10% AND 18%...WITH LOWEST VALUES ACRS THE SLV/NORTHERN NY ZNS ON TUES AFTN. GIVEN DEEP DRY LAYER...EXPECT PLENTY OF SUNSHINE WITH TEMPS 5 TO 10 DEGREES BLW NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... AS OF 345 PM EDT MONDAY...PROGRESSIVE MID/UPPER LVL PATTERN WL DEVELOP ACRS THE NE CONUS...WITH CHANGEABLE WX ANTICIPATED. ON TUES NIGHT...COMBINATION OF RETURN SOUTHERLY FLW AND DEVELOPING TIGHT SW TO NE THERMAL GRADIENT WL MAKE FOR A DIFFICULT LOW TEMP FCST. GIVEN...VERY DRY AIR IN PLACE AND SFC DWPTS IN THE SINGLE DIGITS...FEEL TEMPS WL QUICKLY DROP IN THE EARLY HRS...THEN INCREASE AFT MIDNIGHT AS WINDS/CLOUDS INCREASE. THINKING LOWS WL RANGE FROM 5 TO 10F NEK TO 20 TO 25F SLV/CPV. GFS/NAM ARE HANDLING MOISTURE/LIFT PROFILES ASSOCIATED WITH WAA DIFFERENTLY AND THE ACCOMPANYING QPF. NAM IS MUCH MORE AGGRESSIVE WITH QPF FIELDS ACRS OUR CENTRAL/NORTHERN CWA...WITH AMOUNTS NEAR 0.25"...WHILE GFS IS A TRACK TO 0.10". GIVEN...VERY DRY AIRMASS IN PLACE AHEAD OF 5H VORT AND WAA LIFT...AND DEVELOPING SOUTHERLY FLW...WL TREND TWD THE DRIER GFS SOLUTION. WL MENTION CHC POPS TO LOW LIKELY POPS ACRS NNY INTO NORTHERN VT MTNS AFT 06Z WEDS...WITH SOME LIGHT SNOW ACCUMULATION POSSIBLE (TRACE TO 1"). INITIALLY THERMAL PROFILES SUPPORT ALL SNOW...AS 1000 TO 500MB THICKNESS VALUES ARE BLW 540 AND PROGGED 85H TEMPS ARE BTWN -2C AND -4C. BEST 850 TO 500MB RH AND 700 TO 500MB OMEGA LIFTS FROM SW TO NW ACRS OUR CWA BTWN 06Z AND 15Z WEDS. AFTER 15Z...BEST MOISTURE/LIFT IS ACRS OUR EXTREME NORTHERN ZNS...AS WARM ADVECTS INTO OUR CWA. LOCAL 4KM AND NAM SHOWS SOME LLVL DAMMING OF COLD AIR...ESPECIALLY NEK AND EXTREME NORTHERN SLV ON WEDS...CREATING A VERY TIGHT THERMAL GRADIENT. WITH CLRING SKIES PARTS OF THE SLV FROM GOUVERNEUR TO POTSDAM/CANTON WL WARM INTO THE L60S...WHILE NEAR MSS COULD STRUGGLE TO REACH 50F. ELSEWHERE...GIVEN SHARP 925MB THERMAL GRADIENT ACRS OUR CWA...TEMPS WL BE TRICKY...WL MENTION L/M50S CPV TO L/M40S NEK/MTNS OF VT. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 354 PM EDT MONDAY...GFS/ECMWF IN FAIRLY GOOD AGREEMENT ON THE OVERALL PATTERN FOR THURSDAY AND FRIDAY...WITH INCREASING DISAGREEMENT BEYOND FRIDAY. TEMPERATURES THROUGH THE EXTENDED ARE CLOSE TO NORMAL THROUGH FRIDAY...TRENDING ABOVE NORMAL BY THE WEEKEND. SYSTEM EXPECTED TO IMPACT THE REGION ON WEDNESDAY BEGINS TO EXIT NEW ENGLAND THURSDAY. MAINTAINED CHANCE PRECIPITATION PROBABILITIES FOR THURSDAY AFTERNOON...THOUGH HAVE GONE WITH SLIGHT CHANCE PRECIPITATION PROBABILITIES FOR THURSDAY AFTERNOON/EVENING ALONG EASTERN-FACING SLOPES WHERE UPSLOPE SHOWERS MAY CONTINUE TO LINGER. NORTHERLY FLOW THURSDAY NIGHT ALLOWS 850MB TEMPERATURES TO FALL INTO THE -8 TO -10C RANGE. HIGHS ON THURSDAY REACH INTO THE 40S WITH LOWS IN THE 20S TO AROUND 30 IN THE CHAMPLAIN AND SAINT LAWRENCE VALLEYS. WEAK HIGH PRESSURE THEN BUILDS IN FOR FRIDAY WITH TEMPERATURES A COUPLE OF DEGREES COOLER THAN THURSDAY. FOR THE WEEKEND...DIFFERENCES EMERGE IN TIMING REGARDING A DEVELOPING LOW PRESSURE SYSTEM MOVING IN FROM THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION. 12Z GFS TRACKS THE LOW FURTHER TO THE NORTH ON SATURDAY THAN THE 12Z ECMWF...AND IS ALSO MORE PROGRESSIVE THAN THE 12Z ECMWF. DIVERGENT SOLUTIONS CONTINUE INTO EARLY NEXT WEEK. HAVE OPTED TO NOT STRAY TOO FAR FROM CONTINUITY...SO HAVE KEPT MODERATING TEMPERATURES AND SLIGHT CHANCE PRECIPITATION PROBABILITIES GOING THROUGH THE REST OF THE EXTENDED. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... THROUGH 12Z TUESDAY...GUSTY NORTHWEST WINDS WILL CONTINUE THROUGH 00Z WITH GUSTS TO 30 KNOTS EXPECTED...THEN TAPER OFF AND BE SUSTAINED IN THE 10 TO 20 KNOT RANGE. VFR CEILINGS EXIST THROUGH 00Z WITH JUST A FEW FLURRIES...BUT CLOUDS WILL QUICKLY DISSIPATE AROUND SUNSET. VFR CONDITIONS WILL EXIST THROUGH THE REMAINDER OF THE PERIOD. OUTLOOK 18Z TUESDAY THROUGH FRIDAY...VFR/MOSTLY CLR CONDITIONS TUESDAY WITH NW WINDS 10-20 MPH. LOW PRESSURE SYSTEM APPROACHING FROM THE GREAT LAKES REGION BRINGS A CHANCE OF LIGHT RAIN WEDNESDAY...WITH RAIN OR SNOW SHOWERS WEDNESDAY NIGHT INTO THURSDAY MORNING. PERIODS OF MVFR CONDITIONS WILL PREVAIL...WITH BRIEF IFR INTERVALS POSSIBLE. RIDGE OF SFC HIGH PRESSURE SHIFTING EWD FROM THE GREAT LAKES FOR FRIDAY SHOULD BRING LIGHT N-NW WINDS AND A RETURN TO DRIER/VFR CONDITIONS. && .FIRE WEATHER... AS OF 345 PM EDT MONDAY...CONDITIONS CONTINUE TO REMAIN FAVORABLE ON TUESDAY FOR POTENTIAL FIRE WEATHER CONCERNS. TEMPERATURES WILL START OUT COLD...BUT HUMIDITY RECOVERIES OVERNIGHT TONIGHT WILL BE FAIR. MIXING DEVELOPS EARLY AND WITH THE DRIEST PORTION OF THE CANADIAN HIGH MOVING DOWN OVER US...THE IDEA OF SHARPLY FALLING HUMIDITIES LATE MORNING AND AFTERNOON IS A GOOD BET. THIS WILL RESULT IN AFTERNOON RELATIVE HUMIDITIES FALLING INTO THE 12 TO 18 PERCENT RANGE. AS MENTIONED EARLIER...PRESSURE GRADIENT WILL BE STRONGEST IN THE MORNING AND THEN TAPER OFF IN THE AFTERNOON...NEVERTHELESS THE POTENTIAL FOR WIND GUSTS TO 25 MPH WILL EXIST...ESPECIALLY ACROSS VERMONT. FULL SUN WILL HELP DRY THE FINE FUELS...WHICH GOT A REPRIEVE FROM THE LIGHT SNOW/CLOUD COVER ON MONDAY. FORESTRY PERSONNEL INDICATE ABNORMALLY DRY FUELS OVERALL...THUS THE SITUATION WILL BE EXAMINED CLOSELY FOR POSSIBLY UPGRADE TO A RED FLAG WARNING GIVEN THE EXPECTED WEATHER CONDITIONS. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR VTZ001>012-016>019. NY...FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR NYZ026>031-034-035-087. && $$ SYNOPSIS...TABER NEAR TERM...TABER SHORT TERM...TABER LONG TERM...LOCONTO AVIATION...BANACOS/EVENSON FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
349 PM EDT MON MAR 26 2012 .SYNOPSIS... SURFACE HIGH PRESSURE NEAR HUDSON BAY WILL BUILD INTO THE NORTH COUNTRY THROUGH TUESDAY. THIS WILL RESULT IN MAINLY CLEAR SKIES TONIGHT WITH CHILLY TEMPERATURES. ON TUESDAY...PLENTY OF SUNSHINE IS ANTICIPATED WITH TEMPERATURES IN THE 30S TO NEAR 40...ALONG WITH NORTHWEST WINDS OF 10 TO 20 MPH. A WARM FRONT WILL PRODUCE INCREASING CLOUDS WITH SCATTERED RAIN AND SNOW SHOWERS BY WEDNESDAY MORNING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 345 PM EDT MONDAY...BIG PICTURE SHOWS DEEP MID/UPPER LVL TROF ACRS THE NE CONUS WITH RIBBON OF SUBSIDENCE/DRY AIR ALOFT BUILDING INTO OUR REGION. MEANWHILE...SFC ANALYSIS SHOWS 1032MB HIGH PRES BUILDING INTO OUR CWA....WITH SFC DWPTS IN THE SINGLE DIGITS ABOVE/BLW ZERO THIS AFTN. THIS AIRMASS WL BE ACRS OUR FA ON TUES...ALONG WITH PLENTY OF SUNSHINE. FCST CHALLENGE TONIGHT WL BE TEMPS...FOLLOWED BY DWPTS/RH PARAMETERS ON TUES...ALONG WITH SFC WINDS. UPSTREAM MINS LAST NIGHT SHOW MANY TEMPS IN THE SINGLE DIGITS WITH A FEW BLW ZERO READINGS SOUTH OF HUDSON BAY...ASSOCIATED WITH 925MB TEMPS -20C. GIVEN SOME GRADIENT ACRS OUR CWA....LIMITED SNOW PACK...AND SLIGHTLY WARMER 925MB TEMPS...WL MENTION LOWS FROM 0F AT SLK/MTNS TO 5 TO 10F CENTRAL/NORTHERN VT TO 10 TO 15F CPV/SLV. RUC13 AND NAM12 RH PROFILES STILL SHOW SOME 975MB TO 800MB RH ACRS THE NEK/NORTHERN VT MTNS THRU 03Z...THEREFORE WL TRY TO SHOW SOME CLOUDS...BUT OTHERWISE MAINLY CLR SKIES TONIGHT...WITH NW WINDS OF 10 TO 20 WITH GUSTS TO 30 MPH UNTIL MTN...DECREASING TO 5 TO 15 MPH WITH GUSTS TO 20 MPH TWD MORNING. TUESDAY...SFC HIGH PRES CENTERED OVER THE OTTAWA VALLEY AT 12Z WL SHIFT INTO NORTHERN NY BY 15Z AND INTO THE CPV BY 18Z TUES...WITH A WEAKENING PRES GRADIENT. SOUNDINGS SHOW MIXED LAYER WINDS BTWN 15 AND 25 MPH THRU NOON...ESPECIALLY CENTRAL/EASTERN VT...BUT DECREASING AS GRADIENT SLACKENS DURING THE AFTN HRS TO 5 TO 15 MPH. AT VSF...SOUNDING SHOWS MIXED LAYER WINDS OF 25 TO 30 KNTS...THRU 16Z...HELPING TO PRODUCE SFC WIND GUSTS TO 30 MPH...DURING THE MORNING HRS. SOUNDINGS SHOW GOOD MIXING TO 900MB ON TUES AFTN...WHICH WL TRANSFER SOME VERY DRY AIR TO THE SFC. UPSTREAM OBS UNDER SFC HIGH PRES SHOWS DWPTS BTWN -9F AND +5F...COMBINED WITH ANTICIPATED HIGHS IN THE 30S ON TUES...RESULTS IN MIN RH VALUES BTWN 10% AND 18%...WITH LOWEST VALUES ACRS THE SLV/NORTHERN NY ZNS ON TUES AFTN. GIVEN DEEP DRY LAYER...EXPECT PLENTY OF SUNSHINE WITH TEMPS 5 TO 10 DEGREES BLW NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... AS OF 345 PM EDT MONDAY...PROGRESSIVE MID/UPPER LVL PATTERN WL DEVELOP ACRS THE NE CONUS...WITH CHANGEABLE WX ANTICIPATED. ON TUES NIGHT...COMBINATION OF RETURN SOUTHERLY FLW AND DEVELOPING TIGHT SW TO NE THERMAL GRADIENT WL MAKE FOR A DIFFICULT LOW TEMP FCST. GIVEN...VERY DRY AIR IN PLACE AND SFC DWPTS IN THE SINGLE DIGITS...FEEL TEMPS WL QUICKLY DROP IN THE EARLY HRS...THEN INCREASE AFT MIDNIGHT AS WINDS/CLOUDS INCREASE. THINKING LOWS WL RANGE FROM 5 TO 10F NEK TO 20 TO 25F SLV/CPV. GFS/NAM ARE HANDLING MOISTURE/LIFT PROFILES ASSOCIATED WITH WAA DIFFERENTLY AND THE ACCOMPANYING QPF. NAM IS MUCH MORE AGGRESSIVE WITH QPF FIELDS ACRS OUR CENTRAL/NORTHERN CWA...WITH AMOUNTS NEAR 0.25"...WHILE GFS IS A TRACK TO 0.10". GIVEN...VERY DRY AIRMASS IN PLACE AHEAD OF 5H VORT AND WAA LIFT...AND DEVELOPING SOUTHERLY FLW...WL TREND TWD THE DRIER GFS SOLUTION. WL MENTION CHC POPS TO LOW LIKELY POPS ACRS NNY INTO NORTHERN VT MTNS AFT 06Z WEDS...WITH SOME LIGHT SNOW ACCUMULATION POSSIBLE (TRACE TO 1"). INITIALLY THERMAL PROFILES SUPPORT ALL SNOW...AS 1000 TO 500MB THICKNESS VALUES ARE BLW 540 AND PROGGED 85H TEMPS ARE BTWN -2C AND -4C. BEST 850 TO 500MB RH AND 700 TO 500MB OMEGA LIFTS FROM SW TO NW ACRS OUR CWA BTWN 06Z AND 15Z WEDS. AFTER 15Z...BEST MOISTURE/LIFT IS ACRS OUR EXTREME NORTHERN ZNS...AS WARM ADVECTS INTO OUR CWA. LOCAL 4KM AND NAM SHOWS SOME LLVL DAMMING OF COLD AIR...ESPECIALLY NEK AND EXTREME NORTHERN SLV ON WEDS...CREATING A VERY TIGHT THERMAL GRADIENT. WITH CLRING SKIES PARTS OF THE SLV FROM GOUVERNEUR TO POTSDAM/CANTON WL WARM INTO THE L60S...WHILE NEAR MSS COULD STRUGGLE TO REACH 50F. ELSEWHERE...GIVEN SHARP 925MB THERMAL GRADIENT ACRS OUR CWA...TEMPS WL BE TRICKY...WL MENTION L/M50S CPV TO L/M40S NEK/MTNS OF VT. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... AS OF 328 AM EDT MONDAY...A RELATIVELY QUIET EXTENDED FCST. WEAK SFC LOW IS EXPECTED TO TRACK FROM CENTRAL NY TO WELL SOUTH OF NEW ENGLAND DURING WEDNESDAY NIGHT. FEATURE IS ASSOCIATED WITH A MID- LEVEL SHORTWAVE TROUGH...WITH TROUGH AXIS POSITIVELY TILTED IN 00Z GFS AND MOVING EAST OF THE CT RIVER VALLEY BY 12Z THURSDAY. LIMITED MOISTURE AVAILABILITY AND QUICK MOVING SYSTEM...NOT EXPECTING A LOT OF PRECIPITATION ACROSS THE AREA...BUT WILL CARRY OVC SKIES, POPS 40-60 PERCENT, AND QPF VALUES OF 0.10-0.25" FOR WED NIGHT. WEAK SYSTEM MOVES AWAY THURSDAY WITH A FEW LINGERING RAIN OR MTN SNOW SHOWERS EARLY. GENERALLY TRENDING DRIER BY THURSDAY AFTN WITH PREVAILING N-NW FLOW AND SFC RIDGE BEGINNING TO BUILD EWD FROM THE GREAT LKS REGION. PATTERN BECOMES FAIRLY STAGNANT WITH DEEP-LAYER TROUGHING ACROSS THE CANADIAN MARITIMES. WILL BE GOING WITH A DRY FCST THURSDAY NIGHT THROUGH SATURDAY WITH UPSTREAM HIGH PRESSURE IN CONTROL. NEXT WEAK SHORTWAVE TROUGH EXPECTED TO CROSS NEAR OR SOUTH OF THE REGION SAT NIGHT INTO SUNDAY. WILL CARRY JUST A SLIGHT CHANCE OF A FEW SHOWERS ATTM FOR THIS FEATURE GIVEN TIMING UNCERTAINTIES. TEMPERATURES THRU THE PERIOD WILL BE NEAR SEASONAL NORMALS THROUGH FRIDAY WITH NLY WINDS INFLUENCED BY DOWNSTREAM DEEP-LAYER TROUGH. TEMPS THEN TRENDING SEVERAL DEGREES ABOVE NORMAL THIS WEEKEND. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... THROUGH 12Z TUESDAY...GUSTY NORTHWEST WINDS WILL CONTINUE THROUGH 00Z WITH GUSTS TO 30 KNOTS EXPECTED...THEN TAPER OFF AND BE SUSTAINED IN THE 10 TO 20 KNOT RANGE. VFR CEILINGS EXIST THROUGH 00Z WITH JUST A FEW FLURRIES...BUT CLOUDS WILL QUICKLY DISSIPATE AROUND SUNSET. VFR CONDITIONS WILL EXIST THROUGH THE REMAINDER OF THE PERIOD. OUTLOOK 18Z TUESDAY THROUGH FRIDAY...VFR/MOSTLY CLR CONDITIONS TUESDAY WITH NW WINDS 10-20 MPH. LOW PRESSURE SYSTEM APPROACHING FROM THE GREAT LAKES REGION BRINGS A CHANCE OF LIGHT RAIN WEDNESDAY...WITH RAIN OR SNOW SHOWERS WEDNESDAY NIGHT INTO THURSDAY MORNING. PERIODS OF MVFR CONDITIONS WILL PREVAIL...WITH BRIEF IFR INTERVALS POSSIBLE. RIDGE OF SFC HIGH PRESSURE SHIFTING EWD FROM THE GREAT LAKES FOR FRIDAY SHOULD BRING LIGHT N-NW WINDS AND A RETURN TO DRIER/VFR CONDITIONS. && .FIRE WEATHER... AS OF 345 PM EDT MONDAY...CONDITIONS CONTINUE TO REMAIN FAVORABLE ON TUESDAY FOR POTENTIAL FIRE WEATHER CONCERNS. TEMPERATURES WILL START OUT COLD...BUT HUMIDITY RECOVERIES OVERNIGHT TONIGHT WILL BE FAIR. MIXING DEVELOPS EARLY AND WITH THE DRIEST PORTION OF THE CANADIAN HIGH MOVING DOWN OVER US...THE IDEA OF SHARPLY FALLING HUMIDITIES LATE MORNING AND AFTERNOON IS A GOOD BET. THIS WILL RESULT IN AFTERNOON RELATIVE HUMIDITIES FALLING INTO THE 12 TO 18 PERCENT RANGE. AS MENTIONED EARLIER...PRESSURE GRADIENT WILL BE STRONGEST IN THE MORNING AND THEN TAPER OFF IN THE AFTERNOON...NEVERTHELESS THE POTENTIAL FOR WIND GUSTS TO 25 MPH WILL EXIST...ESPECIALLY ACROSS VERMONT. FULL SUN WILL HELP DRY THE FINE FUELS...WHICH GOT A REPRIEVE FROM THE LIGHT SNOW/CLOUD COVER ON MONDAY. FORESTRY PERSONNEL INDICATE ABNORMALLY DRY FUELS OVERALL...THUS THE SITUATION WILL BE EXAMINED CLOSELY FOR POSSIBLY UPGRADE TO A RED FLAG WARNING GIVEN THE EXPECTED WEATHER CONDITIONS. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR VTZ001>012-016>019. NY...FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR NYZ026>031-034-035-087. && $$ SYNOPSIS...TABER NEAR TERM...TABER SHORT TERM...TABER LONG TERM...BANACOS AVIATION...BANACOS/EVENSON FIRE WEATHER...EVENSON
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
300 PM MDT MON MAR 26 2012 .DISCUSSION...20Z SURFACE ANALYSIS HAD LOW OVER CENTRAL WY WITH WELL DEFINED WARM FRONT ALONG I-90 AND COLD FRONT DEVELOPING INTO NORTHEAST CO. 7MB/3HR PRESSURE FALLS AHEAD OF LOW AS SHORTWAVE IS RAPIDLY MOVING INTO SOUTHEAST WY. HIGHLY ELEVATED RETURNS NOW SHOWING UP AHEAD OF SHORTWAVE AND ON NOSE OF 100KT JET STREAK. CONCERN THIS FORECAST IS DISPOSITION OF THESE STRONG WAVE. 12Z/18Z GUIDANCE IN PRETTY GOOD AGREEMENT. IT BRINGS SHORTWAVE OUT NEGATIVELY-TILTED REACHING EASTERN ND BY 12Z TUESDAY. SURFACE LOW RAPIDLY DEEPENS OVER NORTHEAST WY LATE THIS AFTERNOON AND RACES INTO EASTERN ND BY 12Z TUESDAY. COLD FRONT BEHIND LOW RACES EAST- NORTHEAST THROUGH THIS EVENING...PLOWING THROUGH THE CWA BY 06Z. AHEAD OF COLD FRONT...LOW 50S TD/S POOLING GIVING AROUND 1KJ/KG MLCAPE...BUT MLCIN FROM 50-100J/KG JUST AHEAD OF COLD FRONT. THIS WILL BE A TOUGH CAP TO BREAK FOR SURFACE BASED STORMS...BUT LATEST HRRR/LOCAL WRF MODEL SUGGESTS AS BEST UPPER LEVEL FORCING OVERTAKES COLD FRONT JUST NORTHEAST OF SURFACE LOW...WE SHOULD SEE A CLUSTER OF STORMS DEVELOP. DAMAGING WINDS POSSIBLE WITH ANY STORM...AND LARGE HAIL WITH ANY SUPERCELL THAT DEVELOPS GIVEN 0-6KM BULK SHEAR REACHING 20-30M/S. STORMS WOULD MOVE AROUND 45KTS TO THE NORTHEAST. WILL WATCH MESOSCALE DEVELOPMENT FOR SIGNS OF SURFACE BASED CONVECTION. OTHER BIG STORY WILL BE WIND BEHIND COLD FRONT. PRESSURE RISES FORECAST OF 7-11MB BEHIND INITIAL COLD FRONT. COMBINED WITH 850MB WINDS INCREASING TO 55KTS AND STRONG COLD AIR ADVECTION...IT SHOULD BE ENOUGH TO PUSH STRONG WEST-SOUTHWEST WINDS TO THE SURFACE OVER NORTHEAST WY/THE BLACK HILLS/SOUTHWEST SD EARLY THIS EVENING AND THEN OVER NORTHWEST THROUGH SOUTH CENTRAL SD MID- EVENING. SUBSIDENCE BEHIND COLD FRONT VERY IMPRESSIVE AND STRONG DRYING AND LINKAGE THROUGH 700MB. LATEST RUC SHOWING SYSTEM A LITTLE BIT SLOWER THAN PREVIOUSLY THOUGHT...BUT HEADLINES IN PLACE WILL ACCOUNT FOR THAT SCENARIO. AS LOW MOVES INTO ND LATER THIS EVENING...SECONDARY PRESSURE RISE SURGE MOVES INTO NORTHEAST WY/NORTHWEST SD KEEPING WINDS GOING THERE. WINDS SPEEDS SOUTH OF I-90 SHOULD DECREASE SOME AFTER 06Z. TUESDAY...TIGHT GRADIENT WITH 50KT 850MB NORTHWEST WINDS WILL KEEP HIGH WINDS GOING OVER NORTHWEST PORTIONS OF THE CWA THROUGH TUESDAY AFTERNOON. WILL LIKELY NEED AT LEAST A WIND ADVISORY FURTHER SOUTH ON THE SD PLAINS. TEMPERATURES WILL BE NEAR GUIDANCE WITH A FEW LINGERING SHOWERS OVER THE FAR NORTH UNDER CYCLONIC FLOW ALOFT. TUESDAY NIGHT/WEDNESDAY...UPPER RIDGE BUILDS INTO THE CWA BRINGING QUIET WEATHER TO THE AREA. EXTENDED...A MAINLY DRY AND WARM WEATHER PATTERN CAN BE EXPECTED LATE THIS WEEK THROUGH THE WEEKEND AS A WEAK UPPER LEVEL RIDGE BUILDS OVER THE REGION. A WEAK UPPER LEVEL DISTURBANCE AND COOL FRONT PASSING THROUGH THE RIDGE COULD BRING A FEW SHOWERS AND STORMS TO SOUTH CENTRAL SD THURSDAY. HIGHS THROUGH THE END OF THE WEEK WILL BE IN THE 60S AND 70S...WITH THE WARMEST DAY LIKELY BEING SATURDAY. COOLER AIR WILL PUSH INTO THE AREA SUNDAY AS AN UPPER TROUGH CROSSES THE REGION. THIS WILL ALSO BRING CHANCES FOR PRECIPITATION EARLY NEXT WEEK. LIKELY TO BEGIN BUILDING INTO THE WESTERN PORTIONS OF THE AREA ON SUNDAY AS RIDGE SHIFTS TO THE EAST OF THE REGION. && .AVIATION...18Z TAF UPDATE A STRONG LOW PRESSURE SYSTEM WILL SWEEP ACROSS THE AREA LATE THIS AFTERNOON AND EVENING...BRINGING VERY STRONG WEST TO SOUTHWEST WINDS ACROSS THE AREA. SUSTAINED WINDS OF 30 TO 45 MPH AND GUSTS TO 60 MPH CAN BE EXPECTED. GUSTY WINDS WILL LINGER THROUGH TUESDAY MORNING ACROSS MUCH OF WESTERN SD. THERE IS A CHANCE FOR SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON INTO TONIGHT AS THE SYSTEM MOVES THROUGH. SEVERE THUNDERSTORMS WILL BE POSSIBLE EARLY THIS EVENING...MAINLY ACROSS NORTHWEST AND WEST CENTRAL SOUTH DAKOTA PLAINS. && .FIRE WEATHER...A STRONG STORM SYSTEM WILL CROSS THE AREA TONIGHT...BRINGING SHOWERS AND THUNDERSTORMS TO PARTS OF AREA THROUGH TONIGHT. A COLD FRONT WILL CROSS THE AREA LATE THIS AFTERNOON INTO THIS EVENING BRINGING VERY STRONG WESTERLY WINDS. THESE WINDS WILL GRADUALLY SHIFT TO THE NORTHWEST TONIGHT WHILE DECREASING. HOWEVER THE VERY STRONG WINDS ACROSS NORTHWEST INTO CENTRAL SOUTH DAKOTA WILL CONTINUE THROUGH THE DAY TUESDAY. TEMPERATURES TUESDAY ARE EXPECTED TO RISE INTO THE UPPER 50S TO UPPER 60S WHILE RELATIVE HUMIDITIES WILL DROP TO AS LOW AS 15 PERCENT. THESE CONDITIONS WILL PRODUCE CRITICAL FIRE WEATHER CONDITIONS ACROSS MUCH OF THE AREA THROUGH THIS EVENING...AND AGAIN TUESDAY. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...HIGH WIND WARNING UNTIL 6 AM MDT TUESDAY FOR CENTRAL BLACK HILLS- CUSTER CO PLAINS-HERMOSA FOOT HILLS-NORTHERN BLACK HILLS- RAPID CITY-SHANNON-SOUTHERN BLACK HILLS-SOUTHERN FOOT HILLS. RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR BADLANDS AREA- NORTHERN BLACK HILLS-NORTHWESTERN SOUTH DAKOTA PLAINS- SOUTHERN BLACK HILLS-SOUTHWESTERN SOUTH DAKOTA. RED FLAG WARNING FROM 10 AM TO 6 PM MDT TUESDAY FOR BADLANDS AREA-CENTRAL SOUTH DAKOTA PLAINS-NORTHERN BLACK HILLS- NORTHWESTERN SOUTH DAKOTA PLAINS-SOUTH CENTRAL SOUTH DAKOTA- SOUTHERN BLACK HILLS-SOUTHWESTERN SOUTH DAKOTA. HIGH WIND WARNING FROM 6 PM THIS EVENING TO 6 AM MDT TUESDAY FOR BENNETT-JACKSON. HIGH WIND WARNING FROM 9 PM THIS EVENING TO 7 AM CDT TUESDAY FOR MELLETTE-TODD-TRIPP. HIGH WIND WARNING UNTIL MIDNIGHT MDT TONIGHT FOR FALL RIVER. HIGH WIND WARNING FROM 6 PM THIS EVENING TO 6 PM MDT TUESDAY FOR BUTTE-HAAKON-HARDING-NORTHERN MEADE CO PLAINS-PENNINGTON CO PLAINS-PERKINS-SOUTHERN MEADE CO PLAINS-ZIEBACH. HIGH WIND WARNING UNTIL 6 PM MDT TUESDAY FOR NORTHERN FOOT HILLS- STURGIS/PIEDMONT FOOT HILLS. WY...HIGH WIND WARNING UNTIL 6 AM MDT TUESDAY FOR WYOMING BLACK HILLS. RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR LOWER ELEVATIONS OF CROOK AND WESTON COUNTIES-NORTHERN CAMPBELL- SOUTHERN CAMPBELL-WYOMING BLACK HILLS. RED FLAG WARNING FROM 10 AM TO 6 PM MDT TUESDAY FOR LOWER ELEVATIONS OF CROOK AND WESTON COUNTIES-NORTHERN CAMPBELL- SOUTHERN CAMPBELL-WYOMING BLACK HILLS. HIGH WIND WARNING UNTIL MIDNIGHT MDT TONIGHT FOR WESTON. HIGH WIND WARNING FROM 6 PM THIS EVENING TO 6 PM MDT TUESDAY FOR NORTHEASTERN CROOK. HIGH WIND WARNING UNTIL 6 AM MDT TUESDAY FOR NORTHERN CAMPBELL- SOUTHERN CAMPBELL-WESTERN CROOK. && $$ SHORT TERM...HELGESON LONG TERM....CALDERON AVIATION...CALDERON
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1244 PM CDT MON MAR 26 2012 .AVIATION.../FOR THE 18Z TAF ISSUANCE/ VFR CONDITIONS THROUGH THE PERIOD BUT WINDS WILL CREATE SOME PROBLEMS. SOUTHEAST WINDS THROUGH TONIGHT WILL AVERAGE 20 TO 35 MPH WHILE WEST WINDS ON TUESDAY WILL RUN ABOUT 30 TO 40 MPH WITH A FEW GUSTS TO NEAR 50 MPH...ESPECIALLY NORTH OF INTERSTATE 90. ISOLATED THUNDERSTORMS WILL BE POSSIBLE LATER THIS EVENING BUT COVERAGE IS EXPECTED TO REMAIN LOW. OTHERWISE...VFR CEILINGS AND VISIBILITIES ARE EXPECTED. /08 && .DISCUSSION... MESSY FORECAST THE NEXT 24 TO 36 HOURS WITH WIND...FIRE WEATHER AND THUNDERSTORMS WITH AN ISOLATED SEVERE THREAT ALL CONCERNS. TO START...ADDED THE REMAINING FEW COUNTIES IN NW IA TO THE WIND ADVISORY WITH SLB ALREADY SUSTAINED AT 30 MPH. THE REMAINDER OF THE AREA LOOKS GOOD AND WILL BE VERY WINDY TODAY. TEMPERATURES WILL START TO SURGE DURING THE AFTERNOON AS WINDS TURN MORE SOUTHERLY. QUITE A BIT OF CLOUD COVER WILL BE HOWEVER SO NOT EXPECTING HIGH TEMPERATURES TO GET OUT OF HAND. WHAT WE HAVE SEEMS REASONABLE BUT MAY NEED TO CUT BACK A COUPLE OF DEGREES IN PLACES. THE NEXT CONCERN WILL BE THUNDERSTORMS. THE MORNING SOUNDINGS FROM LBF AND UNR ARE VERY DRY AND VERY WARM. WILL BE QUITE DIFFICULT TO GET THUNDERSTORMS GOING IN THIS ENVIRONMENT AND THE LATEST NAM GIVES US NOTHING THROUGH THE NIGHT. THE HRRR ALSO LOOKS DRY THROUGH THE EARLY EVENING. SO...WILL MAINTAIN SOME 20 TO 30 POPS AND WITH THE SHEAR STILL HAVE SOME CONCERN ABOUT A SEVERE THREAT BUT STARTING TO LOOK DIFFICULT. WILL NEED TO WATCH CENTRAL SD LATER TODAY FOR POSSIBLE DEVELOPMENT. WILL GO AHEAD EXTEND THE WIND ADVISORY INTO TUESDAY AS WELL AS ISSUE A RED FLAG WARNING FOR TUESDAY. THE RED FLAG WARNING WILL BE FOR THE SD ZONES AND NW IA ZONES WITH A FIRE WEATHER WATCH IN PLACE FOR SW MN WHERE THE RH VALUES WILL BE A LITTLE HIGHER. IN ALL LIKELIHOOD A RED FLAG WARNING WILL BE NEEDED FOR SW MN WITH SUSTAINED WINDS OF 30 TO 40 MPH. /08 && .PREV DISCUSSION.../ISSUED AT 410 AM CDT/ A POTENT STORM SYSTEM DEVELOPING IN THE NORTHERN HIGH PLAINS TODAY WILL BRING SOME UNSETTLED WEATHER TO THE REGION TODAY AND TONIGHT. DEEP TROUGH OVER THE FOUR CORNER REGION WILL STRENGTHEN AND BECOME CUT OFF AS IT EMERGES IN THE WESTERN PLAINS THIS AFTERNOON THEN TRACKS NORTHEASTWARD ACROSS THE CENTRAL AND NORTHERN PLAINS THROUGH TONIGHT. MEANWHILE...A SURFACE LOW IS EXPECTED TO FORM OVER THE WESTERN DAKOTAS THIS EVENING AND TONIGHT. STRONG THETA E ADVECTION OUT AHEAD OF THIS SYSTEM IS TRIGGERING SOME SCATTERED SHOWERS AND THUNDERSTORMS EARLY THIS MORNING ACROSS NORTHEAST SD AND SOUTHERN MN ALONG THE BOUNDARY. EXPECT THESE STORMS TO PERSIST IN THIS AREA THROUGH THIS MORNING WITH A MINOR WAVE TRACKING NORTHEAST THROUGH THE FORECAST AREA INTO THE EARLY AFTERNOON EXPANDING THE ISOLATED THUNDERSTORM POTENTIAL ACROSS THE BULK OF THE CWA. DESPITE THE STRENGTHENING LOW LEVEL JET/SHEAR AND MODEST MID LEVEL INSTABILITY...THE MAJOR LIMITING FACTOR TODAY WILL BE THE VERY STRONG CAP IN PLACE ACROSS THE REGION WHICH WILL BE DIFFICULT TO OVERCOME. ILL DEFINED SURFACE BOUNDARY SLIPS THROUGH THE FORECAST AREA TONIGHT. AHEAD OF THE FRONT...CAP WEAKENS A BIT THIS EVENING AS THE TROUGH STRENGTHENS. THIS COULD ALLOW SOME STORMS TO DEVELOP IN THE WEST IN THE EVENING AND TRACK EASTWARD THROUGH THE CWA OVERNIGHT. MUCAPE LOOKS LESS IMPRESSIVE DURING THIS PERIOD WHILE SHEAR REMAINS QUITE STRONG. COULD SEE SOME ELEVATED STORMS WITH POSSIBLE SEVERE HAIL AND WINDS INTO THE EARLY MORNING HOURS. ALSO OF CONCERN THIS AFTERNOON WILL BE SURFACE WINDS WITH A STRONG PRESSURE GRADIENT DEVELOPING AND AN STRONG LLJ IN PLACE. WHILE THE COPIOUS CLOUDS AND SOUTHEAST WINDS DO NOT PRESENT THE BEST MIXING POTENTIAL...DO THINK SOME BORDERLINE ADVISORY SUSTAINED WINDS WILL BE ATTAINABLE ACROSS OUR SD...MN...NE AND NORTHERN IA ZONES THIS AFTERNOON. HAVE ISSUED A WIND ADVISORY FOR THE BETTER PART OF THE CWA FOR THIS AFTERNOON AND EVENING. GRADIENT REMAINS QUITE TIGHT INTO TUESDAY AS THE DEEP SURFACE LOW MOVES INTO NORTHERN MINNESOTA AND COLD AIR ADVECTION RUSHES IN BEHIND THE TROUGH. LOOKS LIKE ANOTHER POTENTIAL WIND ADVISORY SITUATION IN PARTICULAR ACROSS THE NORTH. WITH TODAYS HEADLINE IN PLACE...WILL HOLD OFF ISSUING FOR TUESDAY AS WELL. NORTHWEST FLOW SETTLES IN TUESDAY AND WEDNESDAY WITH DRY WEATHER AND COOLER TEMPERATURES...ALBEIT STILL WELL ABOVE NORMALS. BY WEDNESDAY...HIGHS WILL ONLY BE IN THE MID 50S TO UPPER 60S. RIDGING BRINGS SOUTHERLY WINDS AND WARMER TEMPERATURES ON THURSDAY WITH SOME SCATTERED THUNDERSTORMS POSSIBLE IN THE AFTERNOON AND OVERNIGHT WITH THE ARRIVAL OF A SHORTWAVE. MODELS BEGIN TO DIVERGE SIGNIFICANTLY INTO THE WEEKEND WITH THE HANDLING OF RIDGE AND TROUGH FEATURES AND THEREFORE CONFIDENCE IS QUITE LOW. FOLLOWED THE BLENDED SOLUTION FOR THIS TIME FRAME. && .FSD WATCHES/WARNINGS/ADVISORIES... IA...RED FLAG WARNING FROM 11 AM TO 10 PM CDT TUESDAY FOR IAZ300. WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR IAZ001>003-012>014- 020>022-031-032. FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR IAZ301. MN...WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR MNZ071-072-080-081-089- 090-097-098. FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR MNZ900. NE...RED FLAG WARNING FROM 11 AM TO 10 PM CDT TUESDAY FOR NEZ249. WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR NEZ013-014. SD...RED FLAG WARNING FROM 11 AM TO 10 PM CDT TUESDAY FOR SDZ255>258. WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR SDZ038>040-050-052>071. && $$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1110 AM CDT MON MAR 26 2012 .DISCUSSION... MESSY FORECAST THE NEXT 24 TO 36 HOURS WITH WIND...FIRE WEATHER AND THUNDERSTORMS WITH AN ISOLATED SEVERE THREAT ALL CONCERNS. TO START...ADDED THE REMAINING FEW COUNTIES IN NW IA TO THE WIND ADVISORY WITH SLB ALREADY SUSTAINED AT 30 MPH. THE REMAINDER OF THE AREA LOOKS GOOD AND WILL BE VERY WINDY TODAY. TEMPERATURES WILL START TO SURGE DURING THE AFTERNOON AS WINDS TURN MORE SOUTHERLY. QUITE A BIT OF CLOUD COVER WILL BE HOWEVER SO NOT EXPECTING HIGH TEMPERATURES TO GET OUT OF HAND. WHAT WE HAVE SEEMS REASONABLE BUT MAY NEED TO CUT BACK A COUPLE OF DEGREES IN PLACES. THE NEXT CONCERN WILL BE THUNDERSTORMS. THE MORNING SOUNDINGS FROM LBF AND UNR ARE VERY DRY AND VERY WARM. WILL BE QUITE DIFFICULT TO GET THUNDERSTORMS GOING IN THIS ENVIRONMENT AND THE LATEST NAM GIVES US NOTHING THROUGH THE NIGHT. THE HRRR ALSO LOOKS DRY THROUGH THE EARLY EVENING. SO...WILL MAINTAIN SOME 20 TO 30 POPS AND WITH THE SHEAR STILL HAVE SOME CONCERN ABOUT A SEVERE THREAT BUT STARTING TO LOOK DIFFICULT. WILL NEED TO WATCH CENTRAL SD LATER TODAY FOR POSSIBLE DEVELOPMENT. WILL GO AHEAD EXTEND THE WIND ADVISORY INTO TUESDAY AS WELL AS ISSUE A RED FLAG WARNING FOR TUESDAY. THE RED FLAG WARNING WILL BE FOR THE SD ZONES AND NW IA ZONES WITH A FIRE WEATHER WATCH IN PLACE FOR SW MN WHERE THE RH VALUES WILL BE A LITTLE HIGHER. IN ALL LIKELIHOOD A RED FLAG WARNING WILL BE NEEDED FOR SW MN WITH SUSTAINED WINDS OF 30 TO 40 MPH. /08 && .PREV DISCUSSION.../ISSUED AT 410 AM CDT/ A POTENT STORM SYSTEM DEVELOPING IN THE NORTHERN HIGH PLAINS TODAY WILL BRING SOME UNSETTLED WEATHER TO THE REGION TODAY AND TONIGHT. DEEP TROUGH OVER THE FOUR CORNER REGION WILL STRENGTHEN AND BECOME CUT OFF AS IT EMERGES IN THE WESTERN PLAINS THIS AFTERNOON THEN TRACKS NORTHEASTWARD ACROSS THE CENTRAL AND NORTHERN PLAINS THROUGH TONIGHT. MEANWHILE...A SURFACE LOW IS EXPECTED TO FORM OVER THE WESTERN DAKOTAS THIS EVENING AND TONIGHT. STRONG THETA E ADVECTION OUT AHEAD OF THIS SYSTEM IS TRIGGERING SOME SCATTERED SHOWERS AND THUNDERSTORMS EARLY THIS MORNING ACROSS NORTHEAST SD AND SOUTHERN MN ALONG THE BOUNDARY. EXPECT THESE STORMS TO PERSIST IN THIS AREA THROUGH THIS MORNING WITH A MINOR WAVE TRACKING NORTHEAST THROUGH THE FORECAST AREA INTO THE EARLY AFTERNOON EXPANDING THE ISOLATED THUNDERSTORM POTENTIAL ACROSS THE BULK OF THE CWA. DESPITE THE STRENGTHENING LOW LEVEL JET/SHEAR AND MODEST MID LEVEL INSTABILITY...THE MAJOR LIMITING FACTOR TODAY WILL BE THE VERY STRONG CAP IN PLACE ACROSS THE REGION WHICH WILL BE DIFFICULT TO OVERCOME. ILL DEFINED SURFACE BOUNDARY SLIPS THROUGH THE FORECAST AREA TONIGHT. AHEAD OF THE FRONT...CAP WEAKENS A BIT THIS EVENING AS THE TROUGH STRENGTHENS. THIS COULD ALLOW SOME STORMS TO DEVELOP IN THE WEST IN THE EVENING AND TRACK EASTWARD THROUGH THE CWA OVERNIGHT. MUCAPE LOOKS LESS IMPRESSIVE DURING THIS PERIOD WHILE SHEAR REMAINS QUITE STRONG. COULD SEE SOME ELEVATED STORMS WITH POSSIBLE SEVERE HAIL AND WINDS INTO THE EARLY MORNING HOURS. ALSO OF CONCERN THIS AFTERNOON WILL BE SURFACE WINDS WITH A STRONG PRESSURE GRADIENT DEVELOPING AND AN STRONG LLJ IN PLACE. WHILE THE COPIOUS CLOUDS AND SOUTHEAST WINDS DO NOT PRESENT THE BEST MIXING POTENTIAL...DO THINK SOME BORDERLINE ADVISORY SUSTAINED WINDS WILL BE ATTAINABLE ACROSS OUR SD...MN...NE AND NORTHERN IA ZONES THIS AFTERNOON. HAVE ISSUED A WIND ADVISORY FOR THE BETTER PART OF THE CWA FOR THIS AFTERNOON AND EVENING. GRADIENT REMAINS QUITE TIGHT INTO TUESDAY AS THE DEEP SURFACE LOW MOVES INTO NORTHERN MINNESOTA AND COLD AIR ADVECTION RUSHES IN BEHIND THE TROUGH. LOOKS LIKE ANOTHER POTENTIAL WIND ADVISORY SITUATION IN PARTICULAR ACROSS THE NORTH. WITH TODAYS HEADLINE IN PLACE...WILL HOLD OFF ISSUING FOR TUESDAY AS WELL. NORTHWEST FLOW SETTLES IN TUESDAY AND WEDNESDAY WITH DRY WEATHER AND COOLER TEMPERATURES...ALBEIT STILL WELL ABOVE NORMALS. BY WEDNESDAY...HIGHS WILL ONLY BE IN THE MID 50S TO UPPER 60S. RIDGING BRINGS SOUTHERLY WINDS AND WARMER TEMPERATURES ON THURSDAY WITH SOME SCATTERED THUNDERSTORMS POSSIBLE IN THE AFTERNOON AND OVERNIGHT WITH THE ARRIVAL OF A SHORTWAVE. MODELS BEGIN TO DIVERGE SIGNIFICANTLY INTO THE WEEKEND WITH THE HANDLING OF RIDGE AND TROUGH FEATURES AND THEREFORE CONFIDENCE IS QUITE LOW. FOLLOWED THE BLENDED SOLUTION FOR THIS TIME FRAME. && .AVIATION.../FOR THE 12Z TAF ISSUANCE/ GENERALLY VFR CONDITIONS EXPECTED THROUGH THE PERIOD. OUTSIDE CHANCE OF ELEVATED THUNDERSTORMS THIS MORNING FORMING IN NORTHEAST NEBRASKA AND LIFTING NORTH WITH TIME. DUE TO SCATTERED NATURE AND LOW CONFIDENCE...DID NOT INCLUDE ANY MENTION IN TAFS. STRONG GUSTY SOUTHERLY WINDS EXPECTED ACROSS THE FORECAST AREA TODAY. WINDS WILL SLOWLY DECREASE TONIGHT AS COLD FRONT MOVES THROUGH THE AREA. COLD FRONT WILL MOVE THROUGH WITH STRONG WEST TO NORTHWEST WINDS BEHIND THE FRONT. OUTSIDE CHANCE OF A THUNDERSTORM ALONG THE FRONT. ATMOSPHERIC SOUNDINGS LOOK HOPELESSLY CAPPED...SO ONLY INCLUDED CB MENTION AT KHON TERMINAL FOR NOW. && .FSD WATCHES/WARNINGS/ADVISORIES... IA...WIND ADVISORY FROM NOON TODAY TO 10 PM CDT THIS EVENING FOR IAZ001>003-012>014-020. MN...WIND ADVISORY FROM NOON TODAY TO 10 PM CDT THIS EVENING FOR MNZ071-072-080-081-089-090-097-098. NE...WIND ADVISORY FROM NOON TODAY TO 10 PM CDT THIS EVENING FOR NEZ013-014. SD...WIND ADVISORY FROM NOON TODAY TO 10 PM CDT THIS EVENING FOR SDZ038>040-050-052>071. && $$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
259 PM CDT MON MAR 26 2012 .SHORT TERM...TONIGHT AND TUESDAY. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE CENTERED OVER NORTHERN WYOMING AND A WARM FRONT EXTENDING ACROSS SOUTH DAKOTA INTO IOWA. NORTH OF THE WARM FRONT...AND ALONG THE 850MB FRONT...LIGHT SHOWERS CONTINUE TO FALL OUT OF A 9KFT DECK OVER WESTERN AND SOUTHERN WISCONSIN. HARD TO SAY IF ANY OF THESE SHOWERS ARE REACHING THE GROUND OVER CENTRAL WISCONSIN...THOUGH RUC SOUNDINGS SHOW A LARGE DRY WEDGE CENTERED AROUND 850MB THAT WOULD INDICATE MOSTLY VIRGA. FARTHER WEST...ADDITIONAL SHOWER ACTIVITY HAS BEEN DEVELOPING OVER THE NORTHERN PLAINS IN CLOSER PROXIMITY TO THE LOW LEVEL JET AND MOISTURE CONVERGENCE. AS THIS LLJ AND 850MB WARM FRONT MOVE NE OVER THE AREA TONIGHT...PRECIP CHANCES AND PRECIP TYPE REMAIN THE PRIMARY FORECAST CONCERNS. TONIGHT...CHALLENGING FORECAST TONIGHT NO MATTER WHICH WAY YOU SLICE IT. STRONG SHORTWAVE OVER THE ROCKIES WILL LIFT NE ACROSS THE NORTHERN PLAINS TONIGHT. AHEAD OF THE WAVE...AN ALREADY POTENT LLJ WILL CRANK UP TO 60-70KTS OVER THE NORTHERN MISSISSIPPI VALLEY DURING THE EVENING. AS THE LLJ STRENGTHENS...MOISTURE CONVERGENCE WILL RAMP UP ON THE 300K SURFACE OVER NORTHERN MINNESOTA...WESTERN LAKE SUPERIOR...AND NORTHERN WISCONSIN BY LATE IN THE EVENING. THINK WE WILL SEE A WARM AIR ADVECTION WING DEVELOP IN THIS AREA BY MIDNIGHT...WITH PRECIP MOVING INTO NORTHERN AND POSSIBLY CENTRAL WISCONSIN. ADMITTEDLY SOME UNCERTAINTY EXISTS WITH THE TIMING OF THIS PRECIP...DUE TO THE VERY DRY AND SHALLOW POLAR AIRMASS THAT WILL REMAIN IN PLACE. HAVE BACKED OFF A LITTLE ON THE PRECIP ARRIVAL. THIS PRECIP SHOULD THEN LIFT NE THROUGH THE OVERNIGHT PERIOD AS THE LLJ VEERS. BUT THE MAIN UNCERTAINTY REVOLVES AROUND PTYPE. THERMAL RIDGING OVER THE NORTHERN PLAINS WILL SPREAD EAST TONIGHT WHICH MODELS PROJECT CREATES A LARGE WARM NOSE IN THE THERMAL PROFILE CENTERED AROUND 800MB. WITH TEMPS IN THIS WARM NOSE INCREASING TO 6-7C...PRECIP WILL TURN TO ALL LIQUID IN THIS LAYER OVERNIGHT. THE UNCERTAINTY WILL REVOLVE AROUND SURFACE TEMPS AS THE SHALLOW POLAR AIRMASS LINGERS. CLOUD COVER WILL BE INCREASING THROUGH THE EVENING WHERE AFTERNOON TEMPS WILL TOP OUT IN THE MID 40S. HOWEVER...THE AIRMASS IS ALSO QUITE DRY RESULTING IN WET BULB TEMPS MOSTLY BELOW FREEZING OVER NORTH-CENTRAL WISCONSIN FOR MUCH OF THE NIGHT. PRECIP WILL BE TRANSIENT...BUT POTENTIAL WILL BE THERE FOR FREEZING RAIN FOR A FEW HOURS. IF TEMPS ONLY FALL TO 31 OR 32 DEGREES...ANY FREEZING RAIN MAY NOT HAVE MUCH IMPACT DUE TO WARM GROUND TEMPERATURES. WITH THE UNCERTAINTY OF SURFACE TEMPS AND IMPACTS...WILL NOT ISSUE A HEADLINES...THOUGH POTENTIAL WILL BE THERE FOR ONE. A FEW RUMBLES OF THUNDER WILL ALSO BE POSSIBLE DUE TO ELEVATED CAPES REACHING OVER 200 J/KG. TUESDAY...850MB WARM FRONT AND ASSOCIATED MID-LEVEL FGEN WILL LIFT OFF TO THE NORTHEAST SHORTLY AFTER 12Z AND MID/UPPER LEVEL DRYING WILL ARRIVE ABOVE 700MB. PROGGED SOUNDINGS REMAIN FAIRLY MOIST BETWEEN 900-700MB...SO THINKING MAYBE ONLY A FEW SHOWERS WILL REMAIN ONCE THE FGEN INDUCED PRECIP EXITS. UPPER LEVEL FRONT TIED TO THE SHORTWAVE OVER THE NORTHERN PLAINS WILL MAKE HEADWAY ACROSS THE AREA TOMORROW AFTERNOON. PROGGED SOUNDINGS INDICATE THAT THE AREA WILL REMAIN CAPPED FOR CONVECTION...BOTH ELEVATED AND AT THE SURFACE. THE SURFACE WARM FRONT MAY SNEAK INTO CENTRAL WISCONSIN LATE IN THE AFTERNOON BUT STILL CAN ONLY FIND CAPPING. SO IN THE END...NOT EXPECTING THAT MUCH TO HAPPEN TOMORROW. .LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. A FEW SHOWERS POSSIBLE TUESDAY NIGHT AND WEDNESDAY AS A WEAK UPPER TROUGH PASSES THROUGH. THEN A CANADIAN HIGH DROPS DOWN TOWARDS THE EASTERN GREAT LAKES AND BRINGS DRIER AND SOMEWHAT COOLER AIR INTO OUR AREA. A FROST OR FREEZE LOOKS LIKELY EXCEPT ALONG THE IMMEDIATE BAY AND LAKE THURSDAY MORNING. THIS WOULD NORMALLY NOT BE MENTIONED AT THIS TIME OF YEAR BUT THE RECORD WARMTH OF MARCH HAS CAUSED MANY FRUIT TREES TO BLOSSOM AND ORCHARD OWNERS HAVE REQUESTED THAT WE MENTION IN THE FORECAST. THE SURFACE HIGH RETREATS THURSDAY NIGHT AS UPPER FLOW BECOMES NEARLY ZONAL AND JET ENERGY APPROACHES FROM THE PLAINS STATES. AN ASSOCIATED SURFACE TROUGH SHOULD BRING SOME SHOWERS AND ELEVATED THUNDERSTORMS LATE THURSDAY NIGHT AND FRIDAY AS IT MOVES THROUGH THE REGION. WARMER WEATHER EXPECTED FOR SATURDAY AND PALM SUNDAY WITH A CHANCE OF THUNDERSTORMS. THE MODELS HAVE BIG DIFFERENCES BY THE MIDDLE OF NEXT WEEK AND ARE COMPLETELY OUT OF PHASE WITH EACH OTHER MUCH OF THE TIME. BELIEVE THIS IS DUE TO A POSSIBLE PATTERN CHANGE TO RIDGING OVER ALASKA AND THE POSSIBLE ESTABLISHMENT OF A POLAR VORTEX OVER THE GREAT LAKES BY THE SECOND WEEK OF APRIL. && .AVIATION...CANADIAN HIGH PRESSURE WILL RETREAT TO THE NORTHEAST WHILE A WARM FRONT OVER THE NORTHERN PLAINS WILL MOVE NORTHEAST ACROSS THE REGION TONIGHT INTO TUESDAY MORNING. LIGHT SHOWER ACTIVITY OVER WESTERN WISCONSIN WILL SHIFT ACROSS CENTRAL AND NORTHERN WISCONSIN ALONG THE FRONT TONIGHT. WILL SEE INCREASING CLOUDS THIS AFTERNOON AND EARLY THIS EVENING BEFORE PRECIP ARRIVES. PRECIP TYPE IS UNCERTAIN...MAINLY DUE TO THE NEAR SURFACE TEMPERATURES AS COOLING TAKES PLACE TONIGHT. FORECAST MODELS PROJECT TEMPS FALLING TO JUST BELOW FREEZING...THOUGH INCOMING CLOUD COVER MAY KEEP TEMPS SLIGHTLY HIGHER THAN THE MODELS PREDICT. AS A RESULT...THINK FREEZING RAIN AND SLEET IS POSSIBLE OVER NORTHERN WISCONSIN TONIGHT...THOUGH IMPACTS MAY TURN OUT TO BE MINIMAL DUE TO SURFACE TEMPS SO CLOSE TO FREEZING. THE PRECIP WILL PULL OUT LATE TONIGHT...WHICH WILL LEAVE MVFR CIGS OVER CENTRAL AND NORTH-CENTRAL WISCONSIN FOR MUCH OF TUESDAY MORNING. MPC && .MARINE...INCREASING SOUTHEAST WINDS EXPECTED TONIGHT AS LLVL FLOW INCREASES TO 45KTS AT 950MB. DESPITE WARM AIR ADVECTION CENTERED AROUND 800MB... HAVE CONCERNS THAT THE SHALLOW CANADIAN AIRMASS WILL KEEP THE BL A LITTLE MORE MIXY THAN PREVIOUS THINKING THROUGH ABOUT MIDDAY ON TUESDAY. AS A RESULT...THINK LOW END GALES ARE A POSSIBILITY ALONG THE LAKE MICHIGAN SHORELINE. SHOULD SEE STABILITY BECOME A BIG FACTOR TUESDAY AFTERNOON AND WINDS SUBSIDING. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MPC/RDM
AREA FORECAST DISCUSSION...CORRECTED FOR TONIGHT PCPN POTENTIAL
NWS LA CROSSE WI
230 PM CDT MON MAR 26 2012 .SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT 230 PM CDT MON MAR 26 2012 FORECAST CONCERNS FOCUS ON POTENTIALLY STRONG WINDS...STORM AND GRADIENT RELATED...TUE/TUE NIGHT. A UPPER LEVEL SHORTWAVE TROUGH WAS DRIVING ACROSS THE SOUTHERN ROCKIES...PER LATEST WATER VAPOR SATELLITE IMAGERY...WITH THE 26.12Z NAM AND GFS TAKING THIS FEATURE ACROSS NORTHERN MN BY 00Z WED. THE SYSTEM COMES IN STACKED WITH ITS ASSOCIATED SFC LOW...TAKING ITS NORTH-SOUTH COLD FRONT TO THE MISSISSIPPI RIVER BY 18-21Z TUE...AND THEN ACROSS EASTERN WI BY 03Z WED. BEFORE THE HEART OF THIS WEATHER SYSTEM MOVES IN THERE WILL BE STRONG LOW LEVEL 925-850 MB WARM AIR ADVECTION ACROSS THE REGION TONIGHT INTO TUE MORNING...ALONG WITH ADVECTION ON THE ISENTROPIC SFCS. STRONG 850 MB MOISTURE TRANSPORTS AHEAD OF THE FRONT...WITH A 60+ KT LOW LEVEL JET NOSING INTO NORTHERN MN TONIGHT...AND CONTINUING TO POINT TO FAR NORTHERN PORTIONS OF THE REGION. HOWEVER...SATURATION COULD BE A CONCERN A NORTH-SOUTH RUNNING X-SECTIONS AND BUFKIT SOUNDINGS KEEPS THE DEEPER MOISTURE FARTHER NORTH...WITH SATURATION CONFINED UNDER 700 MB FOR THE SOUTHERN 1/2 OF THE FORECAST AREA. THE COMBINATION OF THE LOW LEVEL THERMODYNAMICS...LOW LEVEL JET/MOISTURE TRANSPORT...AND DEEPER SATURATION MAKES PCPN MORE LIKELY ACROSS THE NORTHERN REACHES OF THE REGION TONIGHT. LOCALLY...MOSTLY NORTH OF A WABASHA MN TO BLACK RIVER FALLS WI LINE. HOWEVER...CURRENT 88-D IMAGERY HAS AN EXPANDING BAND OF SHOWERS WHICH HAVE BLOSSOMED ON THE LEADING EDGE OF THE LOWER LEVEL MOISTURE TRANSPORT. RUC13 WOULD SLIDE THIS BAND OF PCPN ACROSS THE FORECAST AREA THIS EVENING...WITH THE MAIN PCPN FOCUS THEN TURNING FARTHER NORTH. WILL WORK PCPN CHANCES WITH THIS IN MIND TUESDAY THE FRONT WILL BE MOVING ACROSS THE AREA...BUT NOT A LOT OF FRONTOGENETIC LIFT ACCORDING TO THE NAM/GFS. SOME MUCAPE OF 250-500 J/KG WORKS INTO NORTHEAST IA/SOUTHWEST WI AHEAD OF THE BOUNDARY. 0-3 KM SHEAR CONTINUES TO BE STRONG AT 40-45 KTS FROM THE WEST. BUFKIT SOUNDINGS INDICATE SOME DRYING IN THE SUB CLOUD LAYER...INVERTED-V SHAPE. EXPECT SOME SHOWERS TO STORMS TO DEVELOP ALONG AND JUST AHEAD OF THE FRONT...AND IF ANY WOULD BECOME STRONG TO SEVERE...DAMAGING WINDS WOULD BE THE MAIN CONCERN. EVEN PERKY SHOWERS WILL BE ABLE TO ACCELERATE SOME WIND TO THE SFC...WITH 40 MPH WIND GUSTS CERTAINLY POSSIBLE. SPEAKING OF THE WINDS...THE PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN TONIGHT...STAYING THAT WAY INTO TUESDAY NIGHT. 60 KT WINDS BY 2000 FT...BUT ABOVE THE INVERSION. POST THE FRONT THOUGH...MIXING IS DEEPER AND ALTHOUGH THE LOW LEVEL WIND FIELD WON/T BE AS STRONG...THE POTENTIAL FOR HIGHER WIND GUSTS EXISTS. DON/T BELIEVE A WIND ADVISORY WILL BE NEEDED AT THIS TIME...BUT IT COULD BE CLOSE ACROSS THE OPEN AND UNSHELTERED AREAS OF SOUTHEAST MN/NORTHEAST IA TUE AFTERNOON/EVENING. HIGH PRESSURE WILL WORK ACROSS THE REGION WED NIGHT...BRINGING MOSTLY CLEAR SKIES AND LIGHTER WINDS. IN ADDITION...COLDER...BUT SEASONABLE AIR WILL RETURN...WITH RADIATIONAL COOLING HELP TEMPERATURES FALL OFF INTO THE MID TO LOWER 30S BY DAYBREAK THU. PATCHY TO AREAS OF FROST LOOK LIKELY. CONSIDERING THE RECENT VERY WARM TEMPS AND EARLY START TO THE GROWING SEASON...COLD DAMAGE COULD OCCUR TO TENDER VEGETATION AND COLD SENSITIVE PLANTS. A FROST ADVISORY MAY BE NEEDED FOR WEDNESDAY NIGHT. .LONG TERM...FRIDAY THROUGH MONDAY 230 PM CDT MON MAR 26 2012 GFS AND ECMWF IN PRETTY GOOD AGREEMENT WITH RETURN FLOW POST A HIGH INTERACTING WITH A SHORTWAVE TROUGH A LOFT TO TRIGGER AREAS OF SHOWERS AND ISOLATED THUNDERSTORMS THU NIGHT-FRI. BOTH MODELS THEN FAVOR ANOTHER SHORTWAVE TROUGH SLIDING ACROSS THE UPPER MISSISSIPPI RIVER VALLEY FRI NIGHT...POSSIBLY INTO SAT. SOME DIFFERENCES WITH TIMING...POSITIONING AND STRENGTH...BUT THERE DOES LOOK TO BE SOME PCPN CHANCES IN THIS TIME FRAME. A STRONGER TROUGH AND SFC COLD FRONT COULD THEN IMPACT THE AREA SUNDAY INTO MONDAY. AGAIN...DIFFERENCES IN THE MODELS...ALTHOUGH THE SENSIBLE WEATHER IS SIMILAR. SUNDAY NIGHT APPEARS TO BE THE MOST FAVORABLE TIME FOR CONVECTION ALONG THE FRONT TO MOVE IN. && .AVIATION...THROUGH 18Z TUESDAY 1255 PM CDT MON MAR 26 2012 ISOLATED SHOWERS AND BREEZY EAST/SOUTHEAST WINDS WILL PERSIST AT THE TAF SITES THROUGH EARLY THIS EVENING. PLAN ON VFR CONDITIONS WITH CEILINGS IN THE 4 TO 5 KFT RANGE. LOOK FOR WIND SPEEDS OF 15 TO 20 KTS...GUSTING TO AROUND 21 KTS AT KLSE AND UP TO 30 KTS AT KRST. LOW LEVEL WIND SHEAR WILL BE A POTENTIAL CONCERN THIS EVENING THROUGH THE OVERNIGHT HOURS. WINDS WILL INCREASE FROM THE SURFACE AND VEER SOUTHWEST..INCREASING TO 60 KTS AT 2 KFT. HAVE NOT INCLUDED LLWS IN THE TAF GIVEN THE EXPECTED SURFACE WINDS SPEEDS...BUT IT MAY NEED TO BE ADDED THIS EVENING IF SURFACE WINDS DROP OFF. THE LOW LEVEL JET WILL BRING AN OUTSIDE CHANCE OF A SHOWER OR ISOLATED THUNDERSTORM THROUGH THE OVERNIGHT HOURS. CEILINGS ARE EXPECTED TO LOWER INTO THE MVFR RANGE TUESDAY MORNING AS MOIST LOW LEVEL AIR CONTINUES TO BE PUMPED INTO THE REGION AHEAD OF AN APPROACHING COLD FRONT. SOUTHWEST WINDS WILL INCREASE LATE TUESDAY MORNING AHEAD OF THE FRONT. PLAN ON SOUTHWEST WINDS OF 15 TO 20 KTS...WITH GUSTS AROUND 34 KTS POSSIBLE. THE FRONT WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA TUESDAY AFTERNOON. SOME OF THE STORMS COULD PRODUCE STRONG AND GUSTY WINDS...ESPECIALLY IN THE 18Z-22Z TIMEFRAME. PLAN ON STRONG WEST WINDS OF 17 TO 26 KTS...WITH GUSTS AROUND 38 KTS LATE TUESDAY AFTERNOON INTO TUESDAY EVENING. && .ARX WATCHES/WARNINGS/ADVISORIES... 230 PM CDT MON MAR 26 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RIECK LONG TERM....RIECK AVIATION.....WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1256 PM CDT MON MAR 26 2012 .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT 325 AM CDT MON MAR 26 2012 THE MAIN FOCUS GOING THROUGH MID WEEK IS WITH THE PRECIPITATION CHANCES TODAY INTO TOMORROW AND WHETHER ANY SEVERE THUNDERSTORMS WILL BE POSSIBLE TUESDAY AFTERNOON. CURRENTLY...A BAND OF SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS HAS DEVELOPED ACROSS SOUTHERN MINNESOTA INTO NORTHEAST IOWA AND SOUTHWEST WISCONSIN AS A RESULT OF THE COMBINATION OF A FRONTOGENETIC CIRCULATION BETWEEN 850-500MB AND THE EASTERN WING OF INCREASING 925-850MB MOISTURE TRANSPORT. THIS CONVECTION IS REACHING THE GROUND DESPITE A DRY LOW LEVEL AIR MASS THAT FEATURES A DEW POINT DEPRESSION OF ABOUT 35C AT 830MB PER THE 26.00Z MPX SOUNDING. THE QUESTION FOR THIS MORNING IS WITH HOW LONG THE CONVECTION WILL HOLD ON FOR. THE 26.00Z NAM CROSS SECTIONS SHOW THIS FRONTOGENETIC CIRCULATION DRIFTING NORTH AND STAYING STRONG THROUGHOUT THE MORNING AND EARLY AFTERNOON BEFORE WEAKENING THIS AFTERNOON. WITH 26.05Z AND PREVIOUS HRRR RUNS SHOWING THIS PRECIPITATION HOLDING ON INTO THE MORNING...HAVE KEPT SOME DECENT CHANCES FOR SHOWERS/ISOLATED THUNDER GOING INTO THE AFTERNOON. ALSO...SKIES REMAINED MOSTLY CLEAR OVERNIGHT ACROSS NORTHERN WISCONSIN AND ALLOWED FOR TEMPERATURES TO DROP BELOW FREEZING AT MEDFORD. THEREFORE...WILL KEEP THE FREEZE WARNING GOING UNTIL 8AM FOR TAYLOR COUNTY. JUST AS THIS FIRST BAND OF FORCING WEAKENS THIS AFTERNOON...925-850MB MOISTURE TRANSPORT AND ISENTROPIC LIFT ON THE 300-310K SURFACES WILL BE ON THE INCREASE ACROSS SOUTHERN MINNESOTA AND NORTH CENTRAL IOWA. THIS WILL LEAD TO A BAND OF CONVECTION REDEVELOPING ACROSS THIS AREA WHILE LIFTING TO THE NORTHEAST THROUGH THE LATE AFTERNOON AND EVENING HOURS. WITH THIS 925-850MB MOISTURE TRANSPORT NOSE SHIFTING NORTHEAST AND STRENGTHENING THROUGH THE EVENING AND OVERNIGHT HOURS...CHANCES STILL LOOK FAIRLY GOOD FOR THIS CONVECTION HOLDING ON THROUGH THE NIGHT...PARTICULARLY ACROSS SOUTHEAST MINNESOTA AND WESTERN WISCONSIN. A FEW HUNDRED J/KG OF MID LEVEL INSTABILITY FEEDING INTO THESE SHOWERS SHOULD LEAD TO SOME THUNDER OCCURRING...BUT NOTHING VIGOROUS ENOUGH TO GET ORGANIZED AND POSE A SEVERE THREAT. AS THIS FEATURE LIFTS OFF TO THE NORTH...THE MAIN CHANNEL OF LOW LEVEL MOISTURE TRANSPORT WILL MOVE ACROSS THE REGION TUESDAY MORNING AHEAD OF THE COLD FRONT OR POSSIBLY A PRE-FRONTAL TROUGH. AS THIS MOISTURE FEED SHIFTS EAST TUESDAY AFTERNOON...THE MAIN COLD FRONT WILL TRACK EAST AS WELL AND GET TO THE MISSISSIPPI RIVER BY MID AFTERNOON. THE 26.00Z NAM CONTINUES TO SHOW SOME 0-3KM MUCAPE OF 500-1500 J/KG DEVELOPING AHEAD OF THIS FRONT IN THE AFTERNOON...BUT DOES NOT SHOW MUCH IN THE WAY OF QPF ACROSS SOUTHWEST WISCONSIN. IT DOES CONVECT FURTHER SOUTH IN EASTERN IOWA WHERE THIS INSTABILITY CROSSES THE LOW LEVEL MOISTURE TRANSPORT. DESPITE 0-3KM WIND SHEAR BEING VERY FAVORABLE AT 40KTS...THE PROSPECTS FOR ORGANIZED CONVECTION STILL APPEAR TO BE FAIRLY LOW ACROSS SOUTHWEST WISCONSIN. IF THE COLD FRONT CAN PROVIDE ENOUGH OF A KICKER...A FEW STORMS MAY BE ABLE TO FORM THOUGH THE WINDOW LOOKS VERY SMALL IN THE LATE AFTERNOON. AFTER THE FRONT MOVES THROUGH...A COOLER AND VERY DRY AIR MASS ADVECTS INTO THE REGION WITH 850MB TEMPERATURES DROPPING FROM +10C TUESDAY AFTERNOON TO AROUND -2C BY WEDNESDAY MORNING. WITH THIS COLDER...YET SEASONAL...AIR MASS IN PLACE...LOW TEMPERATURES WEDNESDAY NIGHT WILL BE CLOSE TO FREEZING IN WESTERN WISCONSIN. HAVE NOT PUT ANY FROST IN THE FORECAST YET SINCE WINDS APPEAR TO STAY STRONG ENOUGH TO KEEP ANY FROM FORMING. .LONG TERM...THURSDAY THROUGH SUNDAY NIGHT 325 AM CDT MON MAR 26 2012 EXTENDED GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH FRIDAY BEFORE THE 26.00Z GFS AND ECMWF GET OUT OF PHASE WITH EACH OTHER. A RIDGE OF HIGH PRESSURE WILL MOVE THROUGH THE REGION ON THURSDAY BEFORE A MID LEVEL SHORTWAVE TROUGH SWINGS ACROSS THE NORTHERN PLAINS THURSDAY NIGHT. THIS WILL BRING SOUTHERLY RETURN FLOW UP INTO THE UPPER MISSISSIPPI RIVER VALLEY AHEAD OF THIS TROUGH AND BRING THE NEXT ROUND OF SHOWERS/STORMS ON IN. SOME DISCREPANCIES START SHOWING UP ON FRIDAY AS THE 26.00Z GFS HOLDS ONTO THE PRECIPITATION LONGER THAN THE 26.00Z ECMWF. THE 26.00Z ECMWF/GEM BOTH BRING A MORE POTENT LOW THROUGH ON FRIDAY/SATURDAY THAN WHAT THE 26.00Z GFS HAS. BEYOND THIS...THE GFS HOLDS UP THE TROUGH OUT WEST WHILE THE ECMWF IS MUCH MORE PROGRESSIVE. FOR NOW...HAVE CONTINUED THE TREND OF GOING WITH A CONSENSUS BLEND OF EACH RATHER THAN TO GRAB ONTO ONE EXTREME OR THE OTHER WITH THE GFS BEING THE WARM EXTREME AND THE ECMWF BEING THE COLD EXTREME. && .AVIATION...THROUGH 18Z TUESDAY 1255 PM CDT MON MAR 26 2012 ISOLATED SHOWERS AND BREEZY EAST/SOUTHEAST WINDS WILL PERSIST AT THE TAF SITES THROUGH EARLY THIS EVENING. PLAN ON VFR CONDITIONS WITH CEILINGS IN THE 4 TO 5 KFT RANGE. LOOK FOR WIND SPEEDS OF 15 TO 20 KTS...GUSTING TO AROUND 21 KTS AT KLSE AND UP TO 30 KTS AT KRST. LOW LEVEL WIND SHEAR WILL BE A POTENTIAL CONCERN THIS EVENING THROUGH THE OVERNIGHT HOURS. WINDS WILL INCREASE FROM THE SURFACE AND VEER SOUTHWEST..INCREASING TO 60 KTS AT 2 KFT. HAVE NOT INCLUDED LLWS IN THE TAF GIVEN THE EXPECTED SURFACE WINDS SPEEDS...BUT IT MAY NEED TO BE ADDED THIS EVENING IF SURFACE WINDS DROP OFF. THE LOW LEVEL JET WILL BRING AN OUTSIDE CHANCE OF A SHOWER OR ISOLATED THUNDERSTORM THROUGH THE OVERNIGHT HOURS. CEILINGS ARE EXPECTED TO LOWER INTO THE MVFR RANGE TUESDAY MORNING AS MOIST LOW LEVEL AIR CONTINUES TO BE PUMPED INTO THE REGION AHEAD OF AN APPROACHING COLD FRONT. SOUTHWEST WINDS WILL INCREASE LATE TUESDAY MORNING AHEAD OF THE FRONT. PLAN ON SOUTHWEST WINDS OF 15 TO 20 KTS...WITH GUSTS AROUND 34 KTS POSSIBLE. THE FRONT WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA TUESDAY AFTERNOON. SOME OF THE STORMS COULD PRODUCE STRONG AND GUSTY WINDS...ESPECIALLY IN THE 18Z-22Z TIMEFRAME. PLAN ON STRONG WEST WINDS OF 17 TO 26 KTS...WITH GUSTS AROUND 38 KTS LATE TUESDAY AFTERNOON INTO TUESDAY EVENING. && .ARX WATCHES/WARNINGS/ADVISORIES... 1255 PM CDT MON MAR 26 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...HALBACH LONG TERM....HALBACH AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1224 PM CDT MON MAR 26 2012 UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE .SHORT TERM...TODAY AND TUESDAY. ACTIVE PERIOD EXPECTED...WITH CONCERNS ON PCPN AND TYPE AND TEMPERATURES. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE OUT OF CANADA NOSING SOUTH INTO WI. FEW PATCHES OF LOW CLOUDS CONTINUE TO FLOAT IN OFF LAKES. TO SOUTHWEST MID CLOUDS COVER THE AREA...WITH FEW LIGHT SHOWERS MOVING THROUGH SOUTHERN WI ASSOCIATED WITH AN AREA OF FGEN FORCING. FREEZE WARNING WILL REMAIN AS IS. FORECAST ATTENTION ON SIG SHORT WAVE LIFTING NORTHEAST OUT OF WESTERN TROF INTO THE DAKOTAS BY TUE MORNING. AT THE SURFACE...HIGH AND ASSOCIATED COLD AIR MASS TO MOVE EAST TODAY WITH COLD FRONT RETURNING NORTH AS A WARM FRONT TONIGHT. AREA OF STEEP MID LEVEL LAPSE RATES/LI`S NEAR 0 SHIFTS EAST INTO REGION TONIGHT...WITH ELEVATED THUNDER POSSIBLE OVERNIGHT. LOW LEVEL FLOW INCREASES TO 40KTS...FOCUSED OVER NORTH THUS HIGHER POPS OVER NORTHERN CWA. SOUNDINGS INDICATE DRY LAYER BELOW 800MB HAS TO BE OVERCOME THIS EVENING...TRENDED POPS LOWER EAST BEFORE MIDNIGHT. PCPN TYPE ALSO IN QUESTION. DEPTH OF THE BELOW FREEZING LAYER ON SOUNDINGS DEEP ENOUGH TO REFREEZE...WHILE CONVECTION ALSO SUGGESTS SLEET. THOUGH CAN NOT TOTALLY RULE OUT FZRA. TEMPERATURES EXPECTED TO BE JUST BELOW FREEZING FOR LOWS...THEN WARM TOWARD MORNING... LIMITING ZR. WILL NOT PUT ZR IN GRIDS ATTM AND PASS CONCERNS REGARDING IT ON TO NEXT SHIFT. COLD FRONT TO MOVE INTO CWA LATE IN DAY TUE. MODELS SUGGEST POSSIBLE CONVECTION OUT AHEAD OF FRONT. INSTABILITY LIMITED WITH DEW POINTS ONLY RISING INTO THE LOWER 50S. INSTABILITY MAINLY FOCUSED TO OUR SOUTH AND WEST. STRONG SOUTH TO SOUTHEAST FLOW WILL ALSO BE A STABILIZING FACTOR AND LIMIT TEMPERATURES IN THE EAST. HAVE BACKED POPS BACK DOWN INTO SCATTERED RANGE FOR TUE. .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY. LOW PRESSURE ACROSS SOUTHWEST ONTARIO WILL MOVE EAST SOUTHEAST TO NORTH OF LAKE HURON BY 12Z WEDNESDAY MORNING. COLD FRONT WILL MOVE RAPIDLY EAST OF THE STATE TUESDAY NIGHT. BEEN CONTEMPLATING IF A SMALL CHANCE WOULD BE NEEDED ACROSS THE EAST. DO THINK IF ANY ACTIVITY DOES FORM TUESDAY AFTERNOON...IT WILL RACE RAPIDLY TO THE NORTHEAST AND BE OUT OF OUR FORECAST AREA BY 00Z. SOME CONCERNS TONIGHT THAT THE MODELS ARE UNDER DOING THE WINDS TUESDAY NIGHT. VERY STRONG WINDS AT 925MB...COMBINED WITH SOME SUBSIDENCE BEHIND THE COLD FRONT AND 850MB COLD ADVECTION SHOULD HELP MIX SOME OF THE STRONGER WINDS ALOFT DOWN TO THE SURFACE. HAVE GONE WITH BLUSTERY WORDING FOR NOW IN THE ZONES. WOULD NOT BE SURPRISED IF A FEW GUSTS TO OVER 30 KNOTS ARE POSSIBLE TUESDAY EVENING. WINDS SHOULD GRADUALLY DIMINISH OVERNIGHT. ON WEDNESDAY...CONTINUED CHANCES FOR RAIN OR SNOW OVER FAR NORTH CENTRAL WISCONSIN. ON THE 00Z MODEL RUNS TONIGHT...BOTH THE GFS/WRF INDICATING 500MB TROUGH MOVING ACROSS NORTHEAST WISCONSIN WHILE THE BOTH MODELS DO SHOW SOME SURFACE CONVERGENCE ALONG A WEAK TROUGH/COLD FRONT. DID EXPAND PRECIPITATION CHANCES FURTHER SOUTH AND NOW INCLUDES MOST OF THE FORECAST AREA EXCEPT THE VERY FAR SOUTHWEST. HIGH PRESSURE WILL BUILD INTO NORTH CENTRAL AND NORTHEAST WISCONSIN WEDNESDAY NIGHT. WITH RIDGE AXIS OVERHEAD BY 12Z THURSDAY...A WIDESPREAD FREEZE IS LIKELY ACROSS THE NORTH AWAY FROM THE BAY WITH AREAS OF FROST OVER THE REMAINDER OF THE FORECAST AREA. WITH THE RECENT RECORD WARMTH...THE GROWING SEASON HAS STARTED VERY EARLY ACROSS WISCONSIN. HAVE ADDED FROST TO THE FORECAST TO INDICATE THE POTENTIAL FOR MORE TEMPERATURES AT OR BELOW FREEZING. NEXT SYSTEM WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA THURSDAY NIGHT INTO FRIDAY. NEXT WEEKEND STILL LOOKS MUDDLED BETWEEN THE MODELS...THEREFORE NO CHANGES TO THE FORECAST. && .AVIATION...CANADIAN HIGH PRESSURE WILL RETREAT TO THE NORTHEAST WHILE A WARM FRONT OVER THE NORTHERN PLAINS WILL MOVE NORTHEAST ACROSS THE REGION TONIGHT INTO TUESDAY MORNING. LIGHT SHOWER ACTIVITY OVER WESTERN WISCONSIN WILL SHIFT ACROSS CENTRAL AND NORTHERN WISCONSIN ALONG THE FRONT TONIGHT. WILL SEE INCREASING CLOUDS THIS AFTERNOON AND EARLY THIS EVENING BEFORE PRECIP ARRIVES. PRECIP TYPE IS UNCERTAIN...MAINLY DUE TO THE NEAR SURFACE TEMPERATURES AS COOLING TAKES PLACE TONIGHT. FORECAST MODELS PROJECT TEMPS FALLING TO JUST BELOW FREEZING...THOUGH INCOMING CLOUD COVER MAY KEEP TEMPS SLIGHTLY HIGHER THAN THE MODELS PREDICT. AS A RESULT...THINK FREEZING RAIN AND SLEET IS POSSIBLE OVER NORTHERN WISCONSIN TONIGHT...THOUGH IMPACTS MAY TURN OUT TO BE MINIMAL DUE TO SURFACE TEMPS SO CLOSE TO FREEZING. THE PRECIP WILL PULL OUT LATE TONIGHT...WHICH WILL LEAVE MVFR CIGS OVER CENTRAL AND NORTH-CENTRAL WISCONSIN FOR MUCH OF TUESDAY MORNING. MPC && .MARINE...SMALL CRAFT WILL BE ALLOWED TO RUN THROUGH 15Z. WINDS HAVE DROPPED BELOW CRITERIA...THOUGH WAVES WILL BE SLOWER TO DROP OFF. INCREASING SOUTHEAST...SOUTH WINDS EXPECTED TONIGHT AS LLVL FLOW INCREASES TO 40KTS AT 925MB. UNDER WAA REGIME HAVE CONCERNS THAT A STRONG INVERSION WILL LIMIT MIXING OF HIGHER WINDS DOWN...WITH GFS SOUNDINGS SUGGESTING SAME. WILL STAY WITH STRONG SMALL CRAFT WORDING AT THIS TIME. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$