Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 04/15/12
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
1038 AM PDT FRI APR 13 2012
.SYNOPSIS...
RAIN SHOWERS AND MOUNTAIN SNOW EXPECTED TODAY WITH AN ADDITIONAL
CHANCE OF VALLEY AND FOOTHILL THUNDERSTORMS THIS AFTERNOON.
THUNDERSTORMS MAY BECOME SEVERE WITH HAIL, STRONG WINDS, DANGEROUS
LIGHTNING, AND HEAVY DOWNPOURS THE MAIN THREATS. THE STORM SYSTEM IS
FORECAST TO MOVE OUT BY LATE TONIGHT. HIGH PRESSURE WILL MOVE IN
THIS WEEKEND BRINGING DRY CONDITIONS AND WARMER TEMPERATURES
THROUGH THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...UPPER LOW IS POSITIONED OFF THE NORCAL COAST THIS
MORNING AND BEGINNING TO DIG SOUTHEAST AS 125 KT UPPER JET ROUNDS
THE BASE. FRONTAL BAND PUSHED INTO THE DISTRICT OVERNIGHT WITH
BRIEF PERIODS OF MODERATE TO HEAVY RAINFALL ACROSS THE CENTRAL
AND SOUTHERN SAN JOAQUIN VALLEY. AUTOMATED GAUGES HAVE GENERALLY
MEASURED FROM A HALF TO ONE INCH RAIN IN THE SJ VALLEY THUS FAR.
PARTS OF THE SOUTHERN SIERRA NEVADA AND FOOTHILLS HAVE SEEN OVER
AN INCH. SNOW LEVEL THIS MORNING IS AT 4000 FEET AROUND YOSEMITE
WITH SNOW DOWN TO AROUND 5000 FEET IN THE TEHACHAPI MOUNTAINS.
WINTER STORM WARNINGS REMAIN IN EFFECT FOR BOTH THE SOUTHERN
SIERRA AND THE KERN COUNTY MOUNTAINS. FOCUS ONCE AGAIN THIS
AFTERNOON WILL BE ON CONVECTION AS THE COLD POOL ALOFT MOVES
OVERHEAD WITH THE POTENTIAL FOR SEVERE THUNDERSTORMS. 12Z NAM HAS
H5 TEMPS OF -31 DEG C ALONG WITH CAPE ~500 J/KG AND LI OF -1.
LATEST RUC SOUNDINGS SHOW CAPE APPROACHING 1000 J/KG AND LI OF -5.
WHILE THIS MAY BE A BIT OVERDONE...IT CERTAINLY LOOKS UNSTABLE
ENOUGH THIS AFTERNOON...ESPECIALLY IF THERE IS SOME CLEARING IN
THE CLOUD SHIELD. THINGS WILL BEGIN TO TAPER OFF TONIGHT AS THE
LOW SHIFTS EAST BUT OROGRAPHICS WILL LIKELY KEEP SOME SHOWERS
GOING ACROSS THE MOUNTAINS OVERNIGHT. THE LOW WILL REACH THE FOUR
CORNERS REGION ON SATURDAY WITH STILL A FEW LINGERING SHOWERS
POSSIBLE FOR THE MOUNTAINS DUE TO WRAP AROUND MOISTURE. AN EPAC
UPPER RIDGE WILL BUILD IN BEHIND THE LOW BRINGING DRY WEATHER AND
A WARMING TREND INTO NEXT WEEK. THE RIDGE WILL FLATTEN OUT NEXT
WEEK BUT THE WESTERLIES KEEP THE STORM TRACK TO OUR NORTH.
&&
.PREV DISCUSSION... /ISSUED 442 AM PDT FRI APR 13 2012/
DISCUSSION...
AN APPROACHING FRONTAL SYSTEM CONTINUES TO PUSH INTO THE
CALIFORNIA COAST THIS MORNING AND THE PRECIPITATION AREA IN
ADVANCE OF THE INCOMING FRONT HAS FILLED IN ACROSS MUCH OF THE
CENTRAL CALIFORNIA INTERIOR DURING THE OVERNIGHT HOURS. THIS COLD
UNSTABLE SYSTEM WILL BE ACCOMPANIED BY A SIGNIFICANT UPPER LEVEL
JET MAX AND IS EXPECTED TO TRIGGER ANOTHER ROUND OF POSSIBLY
STRONG CONVECTIVE ACTIVITY ACROSS OUR AREA TODAY...ACCOMPANIED BY
SOME MORE SMALL AND EVEN SOME NOT SO SMALL HAIL. THE CURRENTLY
OCCURRING SHOWERS HAVE ALREADY BEEN PRODUCING OCCASIONAL LIGHTNING
STRIKES OVERNIGHT. THE FORECAST FOR A COOL...WET AND STORMY FRIDAY
THE 13TH ACROSS OUR AREA IS ON TRACK...WITH SIGNIFICANT SNOWFALL
ACCUMULATIONS IN THE HIGHER ELEVATIONS,,,AND EVEN A COUPLE OF
INCHES POSSIBLE AT PASS LEVELS IN KERN COUNTY BY TONIGHT INTO
SATURDAY AS SNOW LEVELS DROP A BIT BELOW 4000 FEET. WINTER STORM
WARNINGS REMAIN IN EFFECT FOR THE MOUNTAINS...AS WELL AS A WIND
ADVISORY FOR THE DESERTS...AS THE STORM SYSTEM BLOWS THROUGH TODAY
AND TONIGHT.
BY SATURDAY...AS THE SYSTEM PULLS OUT OF THE AREA...DRYER CONDITIONS
WILL SET IN WITH JUST SOME LINGERING MOUNTAIN SHOWERS. TEMPERATURES
WILL BEGIN A WARMING TREND...RECOVERING TO AROUND 10 DEGREES BELOW
CLIMO TOMORROW...AFTER TOPPING OUT AS MUCH AS 15-20 DEGREES BELOW
NORMAL TODAY. THE DRY AND WARMING TREND WILL CONTINUE THROUGH EARLY
NEXT WEEK AS HIGH PRESSURE BUILDS INTO THE REGION. TEMPERATURES
WILL BE BACK TO SEASONAL AVERAGES BY MONDAY AND WILL REMAIN NEAR
NORMAL THROUGH THE END OF THE WEEK,
&&
.AVIATION...
WIDESPREAD MTN OBSCURING IFR CONDITIONS IN MODERATE TO HEAVY SNOW
FALL ACROSS THE SOUTHERN SIERRA NEVADA AND TEHACHAPI RANGE THROUGH
08Z SATURDAY. CONDITIONS IMPROVING AFTERWARD. ACROSS THE SAN JOAQUIN
VALLEY...THUNDERSTORMS POSSIBLE BETWEEN 18Z AND 23Z TODAY.
OTHERWISE...MVFR ACROSS THE VALLEY AND KERN DESERTS WITH LOCAL IFR
CONDITIONS IN HEAVY SHOWERS THROUGH 06Z SATURDAY. MVFR CONDITIONS
CONTINUING THROUGH 18Z SATURDAY.
&&
.AIR QUALITY ISSUES...
NONE.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 11 PM PDT THIS EVENING CAZ096-097.
WINTER STORM WARNING UNTIL 5 AM PDT SATURDAY CAZ095.
WIND ADVISORY UNTIL 5 AM PDT SATURDAY CAZ098-099.
&&
$$
PUBLIC...DCH/JEB
AVN/FW...MOLINA
SYNOPSIS...ANDERSEN
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1121 PM MDT THU APR 12 2012
.AVIATION...
VFR CONDITIONS ARE EXPECTED AT ALL 3 TAF SITES...KPUB...KALS AND
KCOS DURING THE NEXT 24H. LIGHT WINDS ARE EXPECTED TONIGHT AND
TOMORROW MORNING...BUT GUSTY SOUTH TO SOUTHWEST WINDS WILL OCCUR
TOMORROW AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 625 PM MDT THU APR 12 2012/
UPDATE...
UPDATED TO CANCEL THE TORNADO WATCH FOR KIOWA AND PROWERS COUNTIES
FOR THIS EVENING. SATELLITE IMAGERY AND MESOSCALE ANALYSIS
INDICATE THE DRYLINE HAS MIXED EAST INTO KANSAS WITH THE MAIN
THUNDERSTORM THREAT BEING TO OUR NORTH AND EAST. REMOVED
THUNDERSTORMS FROM BOTH COUNTIES FOR THIS EVENING. NO OTHER
CHANGES TO THE FORECAST AT THIS TIME. 88
PREV DISCUSSION... /ISSUED 322 PM MDT THU APR 12 2012/
SHORT TERM...
(TONIGHT AND FRIDAY)
.SEVERE STORMS POSSIBLE NEAR THE KANSAS BORDER THIS AFTERNOON...
DRYLINE AT THIS TIME APPEARS TO BE CENTERED PARALLEL AND NEAR
HIGHWAY 287/385 THROUGH ERN PORTIONS OF BACA...PROWERS...AND KIOWA
COUNTIES. DEWPOINTS OVR THE I-25 CORRIDOR HAVE MIXED OUT TO THE
LOWER TEENS. HRRR STILL SHOWING THE POTENTIAL FOR AN ISOLD STORM OR
TWO DEVELOPING ALONG THE DRYLINE IN THE NEXT HOUR OR TWO...THEN
MOVING FAIRLY QUICKLY INTO KS. ENVIRONMENT IS STILL FAVORABLE E OF
THE DRYLINE FOR THE DEVELOPMENT OF TORNADIC SUPERCELLS...THUS THE
CURRENT TOR WATCH IN EFFECT FOR THIS AREA. 4KM WRF DOES NOT DEVELOP
ANY STRONG CONVECTION IN OUR AREA. SHOULD SEE FAIRLY SHORTLY WHETHER
THE CU FIELD OVR THE FAR SERN PLAINS WILL PRODUCE ANY PERSISTENT
CONVECTION.
FARTHER W...LOW RH AND STRENGTHENING SW WINDS HAVE LED TO MARGINAL
CRITICAL FIRE WX CONDITIONS. WITH WINDS EXPECTED TO CONTINUE TO GUST
THROUGH EARLY EVE...AND MORE DRY AIR ON THE WAY...WILL LEAVE RED
FLAG INTACT FOR THE BALANCE OF THE WARNING. HAVE ALSO CONVERTED THE
FIRE WX WATCH TO A WARNING FOR TOMORROW AFTERNOON FOR THE SAN LUIS
VALLEY...WITH CONTINUED DRY CONDITIONS AND GUSTY SW WINDS. RH SHOULD
BE ABOVE CRITICAL CRITERIA TOMORROW OVR MOST OF THE REMAINDER OF THE
DISTRICT...WITH TEMPS ALOFT FALLING OFF A BIT MORE AND RESULTANT
HIGHER HUMIDITY. EXPECT TEMPS TO VARY FROM THE 50S OVR THE SAN LUIS
VALLEY...UPR ARKANSAS...AND EL PASO-TELLER...TO THE LOWER 70S OVR
THE SERN PLAINS. SHOULD BE A GENERALLY DRY DAY E OF THE DVD. ANOTHER
SHORTWAVE IN ADVANCE OF THE BIG PACIFIC TROUGH FOR THIS WEEKEND WILL
KICK OFF SOME LIGHT SHSN OVR THE DVD DURING THE AFTERNOON...AND COULD
SEE SOME LIGHT ACCUMS OVR THE DVD BY FRI EVE. MAIN SHOW WILL COME
THIS WEEKEND...HOWEVER. 44
LONG TERM...
(FRIDAY NIGHT THROUGH NEXT THURSDAY)
OVERALL...MODEL SOLUTIONS HAVE TRENDED EVER SO SLIGHTLY BACK TO
THE SOUTH REGARDING THE TRACK OF THE UPPER LEVEL LOW ACROSS THE
STATE THIS WEEKEND...WHICH WOULD INCREASE THE THREAT OF HEAVY
PRECIPITATION OVER EASTERN PORTIONS OF THE AREA...ESPECIALLY
SUNDAY. FOR THE MOUNTAINS ALONG THE CONTINENTAL DIVIDE...SMALL
DIFFERENCES IN THE LOW TRACK WON`T HAVE A BIG IMPACT ON SNOW
AMOUNTS...AS ALMOST ALL MEDIUM RANGE MODELS HAVE A PROLONGED
PERIOD OF HEAVY SNOW FROM SATURDAY INTO AT LEAST SUNDAY NIGHT.
HAVE HOISTED A WINTER STORM WATCH FOR ALL OF THE HIGHER TERRAIN
ALONG THE DIVIDE...WHERE SNOW AMOUNTS COULD APPROACH 2 FEET OR
MORE BY LATE SUNDAY NIGHT. FARTHER EAST...NO HIGHLIGHTS YET AS
HEAVY SNOW WOULD BE SATURDAY NIGHT/SUNDAY AND SMALL CHANGES TO THE
TRACK OF THE UPPER LOW WILL HAVE A BIG IMPACT ON PRECIP AMOUNTS.
TAKEN AT FACE VALUE...GFS/ECMWF SUGGEST WARNING CRITERIA SNOWFALL
POSSIBLE OVER PIKES PEAK AND THE HIGHER PORTIONS OF THE
SANGRES...WITH A PERIOD OF HEAVY...WET...WIND DRIVEN SNOW OVER THE
PALMER DIVIDE SUNDAY MORNING. STILL A GOOD DEAL OF
UNCERTAINTY...THOUGH ALL MODELS SUGGEST AT LEAST SOME -SHRA/-SHSN
A GOOD BET LATE SATURDAY NIGHT INTO SUNDAY...AS COLD FRONT RACES
SOUTH AND UPPER LEVEL MOVES OVERHEAD. WILL THUS INCREASE POPS OVER
MOST OF THE EASTERN HALF OF THE AREA...EMPHASIZING A LATE
SAT/EARLY SUN WINDOW. MODELS APPEAR TO HANG ON TO LIGHT PRECIP TOO
LONG SUNDAY NIGHT INTO MONDAY...AS LOW AND MID LEVEL FLOW WILL BE
MAINLY DOWNSLOPE...SO WILL ONLY RUN WITH LOW POPS OVER THE HIGHER
TERRAIN MON INTO MON EVENING. RETURN TO WARMER AND DRIER WEATHER
BEGINS TUE AS FLAT UPPER RIDGE BUILDS OVER THE WESTERN U.S.
AVIATION...VFR CONDITIONS ARE EXPECTED FOR NEXT 24 H FOR THE TAF
SITES. GUSTY SW WINDS WILL PERSIST THROUGH FRI...REACHING PEAK
SPEEDS IN MID-LATE AFTERNOON. PERSISTENT SHSN WILL INCREASE OVR
THE CONTDVD ESPECIALLY BY LATE FRI...IN ADVANCE OF A LARGE STORM
SYSTEM THAT COULD AFFECT THE TERMINALS IN ERN CO THIS WEEKEND.
44
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY EVENING
FOR COZ058-060-066-068.
RED FLAG WARNING FROM NOON TO 8 PM MDT FRIDAY FOR COZ224.
&&
$$
34/34
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
612 PM EDT FRI APR 13 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE MIDDLE ATLANTIC REGION LATE THIS AFTERNOON
WILL MOVE OFF THE EAST COAST TONIGHT AND SATURDAY. THIS WILL ALLOW A
DEVELOPING LOW PRESSURE SYSTEM OVER THE PLAINS STATES TO DEVELOP AND
MOVE TOWARD THE UPPER GREAT LAKES REGION BY LATE WEEKEND. A FRONTAL
SYSTEM ATTACHED TO THIS LOW WILL AFFECT OUR AREA SATURDAY NIGHT AND
EARLY SUNDAY. THE LOW WILL MOVE ACROSS SOUTHERN CANADA EARLY NEXT
WEEK AND A COLD FRONT WILL CROSS OUR AREA EARLY TUESDAY. MORE HIGH
PRESSURE WILL RETURN FOR THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
NUDGED TEMPS UP SLIGHTLY AND LOADED IN HRRR WHICH SEEMED TO HAVE A
PRETTY GOOD HANDLE ON THE SEA BREEZE FRONT.
AFTER QUIET AND FAIR WEATHER THROUGH THE DAY, A MAINLY CLEAR AND
QUIET EVENING AND OVERNIGHT IS IN STORE AS SURFACE HIGH PRESSURE
CONTINUES TO SETTLE OFF THE SOUTHERN MIDATLANTIC TO SOUTHEAST COAST.
WINDS THAT WERE OUT OF THE NORTHWEST THROUGH MOST OF THE DAY WILL
GRADUALLY BACK AND BECOME MORE WESTERLY THIS EVENING AND THROUGH THE
NIGHT. WINDS THROUGH THE NIGHT WILL BE UNDER 10 MPH, AND IN THE MOST
SHELTERED LOCATIONS MAY EVEN BECOME CALM FOR A FEW HOURS. FOR MOST
AREAS, HOWEVER, WE ARE EXPECTING A LIGHT WEST WIND TO PERSIST
THROUGH THE NIGHT. WITH THE AIR REMAINING MIXED ENOUGH TONIGHT AND
WITH RISING DEWPOINTS OVERNIGHT, WE DID NOT FEEL THAT ANY
FROST/FREEZE HEADLINES WERE NEEDED AT THIS TIME. AT BEST, IT IS
POSSIBLE FOR PATCHY FROST OVER THE HIGHER TERRAIN IN THE LEHIGH
VALLEY, SOUTHERN POCONOS, NORTHWEST AND PINE BARREN AREAS IN NJ.
WE ADDED IT TO THE GRIDS AND IN THE HWO AND WILL SEE HOW
TEMPERATURES TREND THIS EVENING ABOUT ANY POSSIBLE HEADLINES OR
STATEMENTS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
HIGH PRESSURE WILL BE SETTLING OFF THE SOUTHEASTERN SEABOARD DURING
SATURDAY. WEST TO SOUTHWESTERLY WINDS ARE EXPECTED DURING SATURDAY,
AND 925MB WINDS ALONG WITH BUFKIT SOUNDINGS SHOW THESE WINDS
BECOMING GUSTY DURING SATURDAY AFTERNOON. MOST OF SATURDAY WILL BE
DRY, WITH AMPLE SUNSHINE INTO THE EARLY AFTERNOON. BY LATE AFTERNOON
TO EVENING, MID TO HIGH CLOUDS WILL BE INCREASING ACROSS THE AREA IN
ADVANCE OF A WARM FRONT. THIS FRONT COULD BRING A FEW SHOWERS TO OUR
NORTHWEST ZONES AROUND SUNSET.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
AN UPPER RIDGE WILL BE BUILDING OVER THE EASTERN PART OF THE COUNTRY
DURING THE FIRST PART OF THE EXTENDED PERIOD. OVER THE WEST...A H5
TROUGH WILL BE DEEPENING. A SFC LOW BETWEEN THESE UPPER FEATURES
WILL STRENGTHEN AND BE CARRIE INTO THE UPPER GREAT LAKES. THE LOW
WILL THEN MOVE ACROSS SRN CANADA EARLY NEXT WEEK. WE WILL BE MOSTLY
TOO FAR WAY FROM THE LOW FOR ANY SIGNIFICANT RAINFALL FROM THE
SYSTEM. ONE EXCEPTION WILL BE SAT NIGHT WHEN THE ATTACHED WARM FRONT
MAY BE CLOSE ENOUGH FOR SOME SCAT SHOWER ACTIVITY. A FEW OF THE
SHOWERS MAY LINGER ACROSS NE PA OR NRN NJ INTO EARLY SUN.
TEMPERATURES WILL BECOME WELL ABOVE NORMAL SUN AND MON WITH HIGH
TEMPERATURES INTO THE 80S IN MANY AREAS. HUMIDITY LEVELS WILL BE
RATHER HIGH ALSO. A COLD FRONT WILL CROSS THE REGION EARLY TUE.
AN UNSETTLED PATTERN WILL BE OVER THE AREA NEXT WEEK WITH A WEAK SFC
HIGH AND A FEW UPPER VORT MAXS MOVING WITH THE UPPER H5 FLOW. THESE
FEATURES MAY TRIGGER SCAT SHOWERS TUE-THU...SO POPS IN THE CHC/SLGT
CHC RANGE ARE IN THE GRIDS ATTM. TEMPERATURES WILL COOL BACK CLOSER
TO NORMAL VALUES BY THE MIDDLE OF NEXT WEEK. HIGHS WED-THU WILL
MOSTLY BE IN THE 60S.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. LATE TODAY,
NORTHWEST WINDS WILL CONTINUE TO BACK TO THE WEST, BECOMING UNDER
TEN KNOTS DURING THIS EVENING. WESTERLY WINDS, GRADUALLY BECOMING
MORE SOUTHWEST, WILL BECOME GUSTY BY SATURDAY AFTERNOON, WITH GUSTS
UP TO 20 KNOTS POSSIBLE. MID/HIGH CLOUDS WILL THEN MOVE INTO THE
REGION LATE SATURDAY INTO SATURDAY EVENING AHEAD OF AN ADVANCING
WARM FRONT.
WE HAVE TAKEN NOTE OF THE SEA BREEZE DEVELOPMENT ALONG THE NJ COAST
AND HAVE INCLUDED THIS IN THE AFTERNOON TAF FOR KACY.
OUTLOOK...
SATURDAY NIGHT...MOSTLY VFR WITH SCATTERED SHOWERS.
SUNDAY THRU MONDAY...MOSTLY VFR.
MONDAY NIGHT THRU WEDNESDAY...MOSTLY VFR WITH SCATTERED SHOWERS.
&&
.MARINE...
WITH HIGH PRESSURE GRADUALLY SETTLING ALONG THE SOUTHEASTERN
SEABOARD THROUGH SATURDAY, WINDS OVER OUR WATERS WILL BE WESTERLY TO
SOUTHWESTERLY. BOTH WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW
ADVISORY CRITERIA TONIGHT THROUGH MOST OF SATURDAY. BY SATURDAY
NIGHT INTO SUNDAY, SEAS AND WIND GUSTS MAY APPROACH SCA CRITERIA.
SHOWERS MAY BE POSSIBLE, AS WELL, WITH A WARM FRONT APPROACHING THE
AREA.
OUTLOOK...
WE MIGHT COME CLOSE TO OR REACH SMALL CRAFT ADVISORY CRITERIA ON
SATURDAY NIGHT ON THE OCEAN. THERE IS A BETTER CHANCE FOR
SMALL CRAFT ADVISORY CONDITIONS IN THE SOUTHWEST FLOW PRECEDING
THE NEXT COLD FRONT FROM SUNDAY NIGHT INTO MONDAY NIGHT. SMALL
CRAFT ADVISORY CRITERIA FOR SEAS MIGHT LINGER INTO PART OF TUESDAY
ON THE OCEAN.
&&
.FIRE WEATHER...
INCREASINGLY DRY AND WINDY CONDITIONS ARE ANTICIPATED ON SATURDAY.
RELATIVE HUMIDITY VALUES WILL BE FALLING DURING THE DAY, AND ARE
EXPECTED TO FALL BELOW 30 PERCENT FOR A TIME IN MOST LOCATIONS. IN
ADDITION, WIND GUSTS AROUND 20 MPH ARE ALSO FORECAST DURING THE
AFTERNOON. FUELS ALSO REMAIN DRY ACROSS THE REGION, THANKS TO THE
RECENT LACK OF PRECIPITATION. AFTER COORDINATION WITH OUR STATE
FORESTRY PARTNERS, WE PLAN TO ISSUE A SPECIAL WEATHER STATEMENT
SATURDAY MORNING TO HIGHLIGHT THE ENHANCED FIRE WEATHER CONCERNS.
&&
.CLIMATE...
POTENTIAL FOR NEAR RECORD HEAT MONDAY.
HERE ARE THE RECORD HIGH TEMPERATURES FOR ALL 8 OF OUR CLIMATE SITES
FOR MONDAY AND TUESDAY.
4/16 4/17
ALLENTOWN 89 - 2002 91 - 2002, 1976
ATLANTIC CITY 89 - 2002 94 - 2002
GEORGETOWN 89 - 2002 94 - 2002
MOUNT POCONO 85 - 2002 87 - 2002
PHILADELPHIA 90 - 2002 95 - 2002
READING 88 - 2002 95 - 1976
TRENTON 90 - 2002 93 - 2002
WILMINGTON 92 - 1896 97 - 1896
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI/KLINE
SHORT TERM...KLINE
LONG TERM...O`HARA
AVIATION...KLINE/O`HARA
MARINE...KLINE/O`HARA
FIRE WEATHER...KLINE
CLIMATE...DRAG
AREA FORECAST DISCUSSION...CORRECTED
NWS MOUNT HOLLY NJ
347 AM EDT FRI APR 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD SOUTH OUT OF CANADA AND ACROSS MUCH OF THE
EAST TODAY AND WILL BUILD OFF THE SOUTHEAST COAST THIS WEEKEND INTO
EARLY NEXT WEEK. AN AREA OF LOW PRESSURE IS EXPECTED TO MOVE THROUGH
THE WESTERN GREAT LAKES REGION AND INTO EASTERN CANADA OVER THE
WEEKEND. A COLD FRONT IS EXPECTED TO STALL JUST NORTH OF THE AREA
OVER WEEKEND INTO EARLY NEXT WEEK. LOW PRESSURE IS FORECAST TO FORM
ACROSS THE SOUTHERN PLAINS AND MOVE ALONG THE BOUNDARY TOWARD
OUR AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE EARLY MORNING FROST/FREEZE HEADLINES WILL REMAIN IN PLACE.
WIDELY SCATTERED SHOWERS CONTINUE TO DRIFT SOUTH THIS MORNING JUST
OFF THE NEW JERSEY COAST. THE SHOWERS APPEAR TO BE IN RESPONSE TO
COLD MID LEVEL TEMPERATURES AND JUST ENOUGH MOISTURE IN THE COLUMN.
0000 UTC SOUNDINGS SHOWED AN INVERTED V SIGNATURE WITH VERY DRY
CONDITIONS BELOW THE INVERSION...SURFACE OBSERVATIONS OVER WESTERN
LONG ISLAND AND NEW YORK CITY SHOW SOME OF THE RAIN IS REACHING THE
GROUND. THE LATEST HRRR RUN SUGGESTS THAT THE SHOWERS RUN OUT OF
STEAM BEFORE SUNRISE...AND BARRING AN INCREASING TREND WILL NOT BE
INCLUDED IN THE EARLY PORTION OF THE NEW FORECAST.
A BATCH OF MAINLY CIRRUS AND MID LEVEL CLOUDINESS CONTINUES TO
AFFECT MARYLAND AND DELAWARE EARLY THIS MORNING. THE CLOUDINESS
APPEARS TO HAVE BEEN INDUCED BY A 110 KT JET DROPPING INTO THE MID
ATLANTIC STATES. THIS CLOUDINESS SHOULD BE EAST OF THE AREA BEFORE
SUNRISE.
AS THE MID LEVEL LONG WAVE TROUGH CONTINUES TO TRUNDLE TO THE
EAST...ITS INFLUENCE WILL LESSEN AS THE DAY PROGRESSES. A SHORT WAVE
OVER THE GREAT LAKES EARLY THIS MORNING SHOULD DIVE SOUTHEAST AND
PASS WELL TO THE SOUTHWEST THIS AFTERNOON. THIS FEATURE SHOULD HAVE
LITTLE TO NO EFFECT ON THE REGION TODAY.
THE MID LEVEL REMAIN FAIRLY COLD. THIS COMBINED WITH STRONG WARMING
(AS NEAR SURFACE LAPSE RATES APPROACH DRY ADIABATIC) SHOULD ALLOW
THE LIMITED AMOUNT OF AVAILABLE MOISTURE TO POOL UNDER THE
INVERSION. THIS IN TURN SHOULD ALLOW SOME CUMULUS TO DEVELOP...BUT
CONVECTIVE TEMPERATURES SHOULD EDGE JUST OUT OF REACH DURING THE
AFTERNOON. OVERALL...THERE SHOULD BE LESS IN THE WAY OF CLOUDINESS
THAN THE PAST FEW DAYS.
WHILE LOW AND MID LEVEL LAPSE RATES SHOULD BE FAIRLY STEEP...THERE
DOES NOT APPEAR TO BE ENOUGH MOISTURE IN THE COLUMN FOR EVEN
ISOLATED SHOWERS TODAY. BASED ON THIS...THE FORECAST WILL REMAIN DRY
FOR TODAY.
AFTER A COOL START...THE DRY AIRMASS SHOULD WARM FAIRLY QUICKLY. AS
THE COLUMN WARMS...FULL SUN TEMPERATURES SHOULD REACH THE MID 60S
SOUTH AND THE MID TO UPPER 50S NORTH. THIS SI CLOSE TO WHAT THE MOS
BLEND IS SHOWING. THE HIGH TEMPERATURES FORECAST WAS A BLEND OF MOS
NUMBERS AND CONTINUITY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
ANY CUMULUS THAT DEVELOPS IN THE DAYTIME HEATING TODAY SHOULD MELT
AWAY FAIRLY QUICKLY THIS EVENING. AS MID LEVEL HEIGHTS RISE TONIGHT
AHEAD OF A RIDGE...FOR THE MOST PART CLOUDINESS SHOULD BE AT A
MINIMUM. SO HIGH CLOUDINESS COULD BREACH THE RIDGE LATER TONIGHT...
BUT MAINLY CLEAR OR CLEAR SKIES SHOULD COVER IT TONIGHT.
AS SURFACE HIGH PRESSURE REPOSITIONS ITSELF OFF THE MID ATLANTIC
COAST THIS EVENING...THE PRESSURE GRADIENT FLOW COULD PRODUCE A
LIGHT WEST WINDS FOR MOST AREAS. THE LIGHT WEST WINDS COULD BE THE
ONLY INHIBITING FACTOR FOR GOOD RADIATIONAL COOLING TONIGHT...AND IT
MAY NOT BE THAT MUCH OF A PROBLEM IN PROTECTED AREAS. FOR THE MOST
PART...LOWS WERE BASED MAINLY ON THE SLIGHT COOLER NAM MOS NUMBERS.
THERE IS A SHOT AT FREEZING TEMPERATURES IN THE COLDEST LOCATIONS OF
THE PINE BARRENS EARLY SATURDAY MORNING. CONFIDENCE IN THIS IS NOT
HIGH YET...AS DEW POINTS COULD SLOW THE FALL LATE TONIGHT.
ELSEWHERE...THE LIGHT WEST FLOW COULD PREVENT MOST AREAS FROM
DROPPING BELOW FREEZING. THEREFORE...WILL LET THE MORNING
FROST/FREEZE HEADLINES RIDE...AND THE DAY CREW CAN GET A LOOK AT THE
FROST POTENTIAL FOR TONIGHT AND SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL BUILD SOUTH OF THE AREA ON SATURDAY AND ANCHOR
ITSELF OFF THE SOUTHEAST COAST OVER THE WEEKEND. AN AREA OF LOW
PRESSURE WILL BE LIFTING OUT OF THE NORTH CENTRAL US AND INTO
EASTERN CANADA THROUGH THE WEEKEND. AS THIS HAPPENS, A WARM FRONT IS
EXPECTED TO LIFT THROUGH OUR AREA LATE SATURDAY INTO SATURDAY NIGHT,
WHILE A FEW SHORT WAVES/VORT MAXES CROSS THE AREA. THIS COULD HELP
LEAD TO SOME PRECIPITATION ACTIVITY LATE SATURDAY INTO SATURDAY
NIGHT.
BY SUNDAY, A SECOND LOW PRESSURE SYSTEM WILL BE STRENGTHENING ACROSS
THE SOUTHERN PLAINS ALONG A FRONTAL BOUNDARY THAT WILL EXTEND FROM
THE LOW PRESSURE IN CANADA INTO THE SOUTHERN PLAINS AREA. THE
FRONTAL BOUNDARY WILL LIKELY STALL TO OUR NORTH AS THE SECOND LOW
PRESSURE SYSTEM MOVES ALONG THIS BOUNDARY TOWARD THE GREAT LAKES
REGION LATE IN THE WEEKEND INTO EARLY NEXT WEEK. EVENTUALLY, A
SECOND FRONTAL BOUNDARY ASSOCIATED WITH THE SECOND LOW PRESSURE
SYSTEM WILL CROSS OUR AREA. RIGHT NOW IT LOOKS LIKE THE MAY OCCUR
AROUND THE TUESDAY TIME PERIOD.
WHILE SUNDAY INTO MONDAY SHOULD REMAIN MOSTLY DRY WITH THE FRONT
REMAINING TO OUR NORTH, ANY SHORT WAVES/VORT MAXES COULD SPARK SOME
SHOWER ACTIVITY. HOWEVER, THIS MAY MOSTLY OCCUR ACROSS MOSTLY OUR
NORTHERN AREAS. PRECIPITATION CHANCES INCREASE STARTING MONDAY NIGHT
AND CONTINUE THROUGH WEDNESDAY WITH THE APPROACH AND PASSAGE OF THE
FRONTAL BOUNDARY. THE ECMWF DEVELOPS ANOTHER LOW ALONG THE FRONTAL
BOUNDARY WEDNESDAY INTO THURSDAY, WHICH WOULD KEEP RAIN CHANCES
ACROSS THE AREA, HOWEVER THE GFS DOES NOT INDICATE THIS. THIS IS AT
THE VERY END OF THE EXTENDED, SO WE WILL NOT MAKE MUCH CHANGE TO THE
CURRENT FORECAST THAT FAR OUT WHICH KEEPS A SLIGHT CHANCE OF
RAIN.
NOW THAT THE GFS HAS PUSHED THE SYSTEM FARTHER NORTH IN THE LAST FEW
RUNS, IT IS AGREEING WITH THE ECMWF AT MONDAY BEING A VERY WARM DAY.
DEPENDING ON WHEN THE FRONT MOVES THROUGH, TUESDAY COULD BE ANOTHER
WARM DAY AS WELL. TEMPERATURES SHOULD RETURN CLOSER TO NORMAL BEHIND
THE FRONTAL PASSAGE LATER IN THE WEEK.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS CONTINUE EARLY THIS MORNING AS MID CLOUDS DRIFT SOUTH
ACROSS THE AREA. SCATTERED SHOWERS REMAIN JUST OFFSHORE...AND EVEN
KACY DOES NOT LOOK TO BE AFFECTED BY THE EARLY MORNING SHOWERS.
VFR CONDITIONS ARE EXPECTED TODAY. THERE SHOULD BE LESS IN THE WAY
OF CUMULUS DEVELOPMENT TODAY...AND THE AIRMASS LOOKS TOO DRY FOR
EVEN ISOLATED SHOWERS. THE GRADIENT WILL SUPPORT WINDS AROUND 10
KNOTS THIS MORNING FROM THE NORTH...AND BACKING WINDS THIS AFTERNOON
SHOULD BE CAPPED AT 12 KNOTS.
VFR CONDITIONS ARE EXPECTED TONIGHT WITH A LIGHT WESTERLY WIND.
OUTLOOK...
SATURDAY...VFR GUSTY WEST-SOUTHWEST WIND SATURDAY.
SATURDAY NIGHT...MOSTLY VFR WITH SCATTERED RAIN SHOWERS.
SUNDAY-MONDAY NIGHT...MOSTLY VFR WITH SCATTERED RAIN SHOWERS. GUSTY
WEST TO SOUTHWEST WINDS EACH AFTERNOON.
TUESDAY...VFR WITH SCATTERED AFTERNOON THUNDERSTORMS...POSSIBLE
LOWER CIG/VSBY IN THUNDERSTORMS.
&&
.MARINE...
WINDS AND SEAS REMAIN BELOW SMALL CRAFT LEVELS EARLY THIS MORNING AS
THE BEST PRESSURE GRADIENT MOVES EAST OF THE WATERS. HIGH PRESSURE
BUILDING EAST FROM THE GREAT LAKES WILL PRODUCE A NORTHERLY WIND
THIS MORNING. AS A PIECE OF THE HIGH REACHES THE MID ATLANTIC COAST
THIS AFTERNOON...WINDS WILL BACK TO WEST AND SOUTHWEST...GENERALLY
REMAINING UNDER 15 KNOTS. THE PRESSURE GRADIENT COULD BACK OFF
ENOUGH LATE THIS AFTERNOON TO ALLOW SEA BREEZE CIRCULATIONS TO
DEVELOP ALONG THE NEW JERSEY COAST.
THE HIGH WILL REPOSITION ITSELF ALONG THE NORTH CAROLINA COAST
TONIGHT. ANY SEA BREEZE CIRCULATIONS WILL SNAP BACK TO THE WEST
SOUTHWEST SYNOPTIC FLOW. WINDS COULD GET TO 15 KNOTS ACROSS THE
OCEAN WATERS AS THE PRESSURE GRADIENT TIGHTENS LATE THIS
EVENING...BUT SUB ADVISORY CONDITIONS ARE EXPECTED TONIGHT.
OUTLOOK...
HIGH PRESSURE WILL BUILD OFF THE SOUTHEAST COAST ON SATURDAY AND
REMAIN THERE INTO EARLY NEXT WEEK. AT THE SAME TIME, A SERIES OF LOW
PRESSURE SYSTEMS ARE FORECAST TO MOVE ALONG A SLOW MOVING FRONTAL
BOUNDARY THAT MAY STALL JUST TO OUR NORTH SUNDAY INTO MONDAY. THE
PRESSURE GRADIENT WILL TIGHTEN BETWEEN THE HIGH TO OUR SOUTH AND THE
LOWS MOVING TO OUR NORTH, AND COULD CREATE AN EXTENDED PERIOD OF
SMALL CRAFT ADVISORY, OR AT LEAST NEAR SMALL CRAFT ADVISORY LEVELS
WINDS, LASTING FROM LATE SATURDAY INTO AT LEAST LATE MONDAY. THE
WINDS ABOVE THE SURFACE ARE FORECAST TO BE QUITE STRONG DURING THIS
TIME PERIOD, BUT THE CONFIDENCE ON THE STRONG WINDS MIXING DOWN TO
THE WATERS IS NOT HIGH. HOWEVER, IF THEY DID MIX DOWN, WE COULD GET
GALE FORCE WINDS, BUT WE DO NOT HAVE THIS IN THE FORECAST FOR NOW.
&&
.FIRE WEATHER...
THE AIRMASS WILL BE DRIER TODAY THAN THE PAST COUPLE OF DAYS...AS
MINIMUM RELATIVE HUMIDITY VALUES DROP BELOW 25 PERCENT ACROSS A GOOD
CHUNK OF THE AREA. WHILE THERE WERE A FEW SHOWERS AROUND THURSDAY
AFTERNOON...THE RAIN THEY PRODUCED DID NOT DO MUCH TO ALLEVIATE THE
DRY FUEL CONDITIONS.
IT APPEARS AS THOUGH THE LIMITING FACTOR TODAY FOR RED FLAG
CONDITIONS WILL BE THE WIND. THE BEST PRESSURE GRADIENT WILL OCCUR
THIS AFTERNOON AS HIGH PRESSURE STRETCHES FROM THE OHIO VALLEY TO
THE MID ATLANTIC STATES. MODEL SOUNDINGS DO NOT SHOW MUCH SUPPORT
FOR GUSTY WINDS...AND WINDS LOOK TO REMAIN BELOW RED FLAG CRITERIA.
SATURDAY NOW APPEARS IT WILL BE ANOTHER DRY AND WINDY DAY, WHICH
WILL CONTINUE ENHANCED FIRE SPREAD CONCERNS.
&&
.CLIMATE...
POTENTIAL FOR NEAR RECORD HEAT MONDAY.
HERE ARE THE RECORD HIGH TEMPERATURES FOR ALL 8 OF OUR CLIMATE SITES
FOR MONDAY AND TUESDAY.
4/16 4/17
ALLENTOWN 89 - 2002 91 - 2002, 1976
ATLANTIC CITY 89 - 2002 94 - 2002
GEORGETOWN 89 - 2002 94 - 2002
MOUNT POCONO 85 - 2002 87 - 2002
PHILADELPHIA 90 - 2002 95 - 2002
READING 88 - 2002 95 - 1976
TRENTON 90 - 2002 93 - 2002
WILMINGTON 92 - 1896 97 - 1896
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR PAZ060-067.
FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR PAZ054-055-061-
062.
NJ...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NJZ008>010-
020>022-027.
FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR NJZ001-007.
DE...NONE.
MD...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MDZ008.
MARINE...NONE.
&&
$$
SYNOPSIS...ROBERTSON
NEAR TERM...HAYES
SHORT TERM...HAYES
LONG TERM...ROBERTSON
AVIATION...HAYES/ROBERTSON
MARINE...HAYES/ROBERTSON
FIRE WEATHER...HAYES/ROBERTSON
CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
334 AM EDT FRI APR 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD SOUTH OUT OF CANADA AND ACROSS MUCH OF THE
EAST TODAY AND WILL BUILD OFF THE SOUTHEAST COAST THIS WEEKEND INTO
EARLY NEXT WEEK. AN AREA OF LOW PRESSURE IS EXPECTED TO MOVE THROUGH
THE WESTERN GREAT LAKES REGION AND INTO EASTERN CANADA OVER THE
WEEKEND. A COLD FRONT IS EXPECTED TO STALL JUST NORTH OF THE AREA
OVER WEEKEND INTO EARLY NEXT WEEK. LOW PRESSURE IS FORECAST TO FORM
ACROSS THE SOUTHERN PLAINS AND MOVE ALONG THE BOUNDARY TOWARD
OUR AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE EARLY MORNING FROST/FREEZE HEADLINES WILL REMAIN IN PLACE.
WIDELY SCATTERED SHOWERS CONTINUE TO DRIFT SOUTH THIS MORNING JUST
OFF THE NEW JERSEY COAST. THE SHOWERS APPEAR TO BE IN RESPONSE TO
COLD MID LEVEL TEMPERATURES AND JUST ENOUGH MOISTURE IN THE COLUMN.
0000 UTC SOUNDINGS SHOWED AN INVERTED V SIGNATURE WITH VERY DRY
CONDITIONS BELOW THE INVERSION...SURFACE OBSERVATIONS OVER WESTERN
LONG ISLAND AND NEW YORK CITY SHOW SOME OF THE RAIN IS REACHING THE
GROUND. THE LATEST HRRR RUN SUGGESTS THAT THE SHOWERS RUN OUT OF
STEAM BEFORE SUNRISE...AND BARRING AN INCREASING TREND WILL NOT BE
INCLUDED IN THE EARLY PORTION OF THE NEW FORECAST.
A BATCH OF MAINLY CIRRUS AND MID LEVEL CLOUDINESS CONTINUES TO
AFFECT MARYLAND AND DELAWARE EARLY THIS MORNING. THE CLOUDINESS
APPEARS TO HAVE BEEN INDUCED BY A 110 KT JET DROPPING INTO THE MID
ATLANTIC STATES. THIS CLOUDINESS SHOULD BE EAST OF THE AREA BEFORE
SUNRISE.
AS THE MID LEVEL LONG WAVE TROUGH CONTINUES TO TRUNDLE TO THE
EAST...ITS INFLUENCE WILL LESSEN AS THE DAY PROGRESSES. A SHORT WAVE
OVER THE GREAT LAKES EARLY THIS MORNING SHOULD DIVE SOUTHEAST AND
PASS WELL TO THE SOUTHWEST THIS AFTERNOON. THIS FEATURE SHOULD HAVE
LITTLE TO NO EFFECT ON THE REGION TODAY.
THE MID LEVEL REMAIN FAIRLY COLD. THIS COMBINED WITH STRONG WARMING
(AS NEAR SURFACE LAPSE RATES APPROACH DRY ADIABATIC) SHOULD ALLOW
THE LIMITED AMOUNT OF AVAILABLE MOISTURE TO POOL UNDER THE
INVERSION. THIS IN TURN SHOULD ALLOW SOME CUMULUS TO DEVELOP...BUT
CONVECTIVE TEMPERATURES SHOULD EDGE JUST OUT OF REACH DURING THE
AFTERNOON. OVERALL...THERE SHOULD BE LESS IN THE WAY OF CLOUDINESS
THAN THE PAST FEW DAYS.
WHILE LOW AND MID LEVEL LAPSE RATES SHOULD BE FAIRLY STEEP...THERE
DOES NOT APPEAR TO BE ENOUGH MOISTURE IN THE COLUMN FOR EVEN
ISOLATED SHOWERS TODAY. BASED ON THIS...THE FORECAST WILL REMAIN DRY
FOR TODAY.
AFTER A COOL START...THE DRY AIRMASS SHOULD WARM FAIRLY QUICKLY. AS
THE COLUMN WARMS...FULL SUN TEMPERATURES SHOULD REACH THE MID 60S
SOUTH AND THE MID TO UPPER 50S NORTH. THIS SI CLOSE TO WHAT THE MOS
BLEND IS SHOWING. THE HIGH TEMPERATURES FORECAST WAS A BLEND OF MOS
NUMBERS AND CONTINUITY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
ANY CUMULUS THAT DEVELOPS IN THE DAYTIME HEATING TODAY SHOULD MELT
AWAY FAIRLY QUICKLY THIS EVENING. AS MID LEVEL HEIGHTS RISE TONIGHT
AHEAD OF A RIDGE...FOR THE MOST PART CLOUDINESS SHOULD BE AT A
MINIMUM. SO HIGH CLOUDINESS COULD BREACH THE RIDGE LATER TONIGHT...
BUT MAINLY CLEAR OR CLEAR SKIES SHOULD COVER IT TONIGHT.
AS SURFACE HIGH PRESSURE REPOSITIONS ITSELF OFF THE MID ATLANTIC
COAST THIS EVENING...THE PRESSURE GRADIENT FLOW COULD PRODUCE A
LIGHT WEST WINDS FOR MOST AREAS. THE LIGHT WEST WINDS COULD BE THE
ONLY INHIBITING FACTOR FOR GOOD RADIATIONAL COOLING TONIGHT...AND IT
MAY NOT BE THAT MUCH OF A PROBLEM IN PROTECTED AREAS. FOR THE MOST
PART...LOWS WERE BASED MAINLY ON THE SLIGHT COOLER NAM MOS NUMBERS.
THERE IS A SHOT AT FREEZING TEMPERATURES IN THE COLDEST LOCATIONS OF
THE PINE BARRENS EARLY SATURDAY MORNING. CONFIDENCE IN THIS IS NOT
HIGH YET...AS DEW POINTS COULD SLOW THE FALL LATE TONIGHT.
ELSEWHERE...THE LIGHT WEST FLOW COULD PREVENT MOST AREAS FROM
DROPPING BELOW FREEZING. THEREFORE...WILL LET THE MORNING
FROST/FREEZE HEADLINES RIDE...AND THE DAY CREW CAN GET A LOOK AT THE
FROST POTENTIAL FOR TONIGHT AND SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL BUILD SOUTH OF THE AREA ON SATURDAY AND ANCHOR
ITSELF OFF THE SOUTHEAST COAST OVER THE WEEKEND. AN AREA OF LOW
PRESSURE WILL BE LIFTING OUT OF THE NORTH CENTRAL US AND INTO
EASTERN CANADA THROUGH THE WEEKEND. AS THIS HAPPENS, A WARM FRONT IS
EXPECTED TO LIFT THROUGH OUR AREA LATE SATURDAY INTO SATURDAY NIGHT,
WHILE A FEW SHORT WAVES/VORT MAXES CROSS THE AREA. THIS COULD HELP
LEAD TO SOME PRECIPITATION ACTIVITY LATE SATURDAY INTO SATURDAY
NIGHT.
BY SUNDAY, A SECOND LOW PRESSURE SYSTEM WILL BE STRENGTHENING ACROSS
THE SOUTHERN PLAINS ALONG A FRONTAL BOUNDARY THAT WILL EXTEND FROM
THE LOW PRESSURE IN CANADA INTO THE SOUTHERN PLAINS AREA. THE
FRONTAL BOUNDARY WILL LIKELY STALL TO OUR NORTH AS THE SECOND LOW
PRESSURE SYSTEM MOVES ALONG THIS BOUNDARY TOWARD THE GREAT LAKES
REGION LATE IN THE WEEKEND INTO EARLY NEXT WEEK. EVENTUALLY, A
SECOND FRONTAL BOUNDARY ASSOCIATED WITH THE SECOND LOW PRESSURE
SYSTEM WILL CROSS OUR AREA. RIGHT NOW IT LOOKS LIKE THE MAY OCCUR
AROUND THE TUESDAY TIME PERIOD.
WHILE SUNDAY INTO MONDAY SHOULD REMAIN MOSTLY DRY WITH THE FRONT
REMAINING TO OUR NORTH, ANY SHORT WAVES/VORT MAXES COULD SPARK SOME
SHOWER ACTIVITY. HOWEVER, THIS MAY MOSTLY OCCUR ACROSS MOSTLY OUR
NORTHERN AREAS. PRECIPITATION CHANCES INCREASE STARTING MONDAY NIGHT
AND CONTINUE THROUGH WEDNESDAY WITH THE APPROACH AND PASSAGE OF THE
FRONTAL BOUNDARY. THE ECMWF DEVELOPS ANOTHER LOW ALONG THE FRONTAL
BOUNDARY WEDNESDAY INTO THURSDAY, WHICH WOULD KEEP RAIN CHANCES
ACROSS THE AREA, HOWEVER THE GFS DOES NOT INDICATE THIS. THIS IS AT
THE VERY END OF THE EXTENDED, SO WE WILL NOT MAKE MUCH CHANGE TO THE
CURRENT FORECAST THAT FAR OUT WHICH KEEPS A SLIGHT CHANCE OF
RAIN.
NOW THAT THE GFS HAS PUSHED THE SYSTEM FARTHER NORTH IN THE LAST FEW
RUNS, IT IS AGREEING WITH THE ECMWF AT MONDAY BEING A VERY WARM DAY.
DEPENDING ON WHEN THE FRONT MOVES THROUGH, TUESDAY COULD BE ANOTHER
WARM DAY AS WELL. TEMPERATURES SHOULD RETURN CLOSER TO NORMAL BEHIND
THE FRONTAL PASSAGE LATER IN THE WEEK.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS CONTINUE EARLY THIS MORNING AS MID CLOUDS DRIFT SOUTH
ACROSS THE AREA. SCATTERED SHOWERS REMAIN JUST OFFSHORE...AND EVEN
KACY DOES NOT LOOK TO BE AFFECTED BY THE EARLY MORNING SHOWERS.
VFR CONDITIONS ARE EXPECTED TODAY. THERE SHOULD BE LESS IN THE WAY
OF CUMULUS DEVELOPMENT TODAY...AND THE AIRMASS LOOKS TOO DRY FOR
EVEN ISOLATED SHOWERS. THE GRADIENT WILL SUPPORT WINDS AROUND 10
KNOTS THIS MORNING FROM THE NORTH...AND BACKING WINDS THIS AFTERNOON
SHOULD BE CAPPED AT 12 KNOTS.
VFR CONDITIONS ARE EXPECTED TONIGHT WITH A LIGHT WESTERLY WIND.
OUTLOOK...
SATURDAY...VFR GUSTY WEST-SOUTHWEST WIND SATURDAY.
SATURDAY NIGHT...MOSTLY VFR WITH SCATTERED RAIN SHOWERS.
SUNDAY-MONDAY NIGHT...MOSTLY VFR WITH SCATTERED RAIN SHOWERS. GUSTY
WEST TO SOUTHWEST WINDS EACH AFTERNOON.
TUESDAY...VFR WITH SCATTERED AFTERNOON THUNDERSTORMS...POSSIBLE
LOWER CIG/VSBY IN THUNDERSTORMS.
&&
.MARINE...
WINDS AND SEAS REMAIN BELOW SMALL CRAFT LEVELS EARLY THIS MORNING AS
THE BEST PRESSURE GRADIENT MOVES EAST OF THE WATERS. HIGH PRESSURE
BUILDING EAST FROM THE GREAT LAKES WILL PRODUCE A NORTHERLY WIND
THIS MORNING. AS A PIECE OF THE HIGH REACHES THE MID ATLANTIC COAST
THIS AFTERNOON...WINDS WILL BACK TO WEST AND SOUTHWEST...GENERALLY
REMAINING UNDER 15 KNOTS. THE PRESSURE GRADIENT COULD BACK OFF
ENOUGH LATE THIS AFTERNOON TO ALLOW SEA BREEZE CIRCULATIONS TO
DEVELOP ALONG THE NEW JERSEY COAST.
THE HIGH WILL REPOSITION ITSELF ALONG THE NORTH CAROLINA COAST
TONIGHT. ANY SEA BREEZE CIRCULATIONS WILL SNAP BACK TO THE WEST
SOUTHWEST SYNOPTIC FLOW. WINDS COULD GET TO 15 KNOTS ACROSS THE
OCEAN WATERS AS THE PRESSURE GRADIENT TIGHTENS LATE THIS
EVENING...BUT SUB ADVISORY CONDITIONS ARE EXPECTED TONIGHT.
OUTLOOK...
HIGH PRESSURE WILL BUILD OFF THE SOUTHEAST COAST ON SATURDAY AND
REMAIN THERE INTO EARLY NEXT WEEK. AT THE SAME TIME, A SERIES OF LOW
PRESSURE SYSTEMS ARE FORECAST TO MOVE ALONG A SLOW MOVING FRONTAL
BOUNDARY THAT MAY STALL JUST TO OUR NORTH SUNDAY INTO MONDAY. THE
PRESSURE GRADIENT WILL TIGHTEN BETWEEN THE HIGH TO OUR SOUTH AND THE
LOWS MOVING TO OUR NORTH, AND COULD CREATE AN EXTENDED PERIOD OF
SMALL CRAFT ADVISORY, OR AT LEAST NEAR SMALL CRAFT ADVISORY LEVELS
WINDS, LASTING FROM LATE SATURDAY INTO AT LEAST LATE MONDAY. THE
WINDS ABOVE THE SURFACE ARE FORECAST TO BE QUITE STRONG DURING THIS
TIME PERIOD, BUT THE CONFIDENCE ON THE STRONG WINDS MIXING DOWN TO
THE WATERS IS NOT HIGH. HOWEVER, IF THEY DID MIX DOWN, WE COULD GET
GALE FORCE WINDS, BUT WE DO NOT HAVE THIS IN THE FORECAST FOR NOW.
&&
.FIRE WEATHER...
THE AIRMASS WILL BE DRIER TODAY THAN THE PAST COUPLE OF DAYS...AS
MINIMUM RELATIVE HUMIDITY VALUES DROP BELOW 25 PERCENT ACROSS A GOOD
CHUNK OF THE AREA. WHILE THERE WERE A FEW SHOWERS AROUND THURSDAY
AFTERNOON...THE RAIN THEY PRODUCED DID NOT DO MUCH TO ALLEVIATE THE
DRY FUEL CONDITIONS.
IT APPEARS AS THOUGH THE LIMITING FACTOR TODAY FOR RED FLAG
CONDITIONS WILL BE THE WIND. THE BEST PRESSURE GRADIENT WILL OCCUR
THIS AFTERNOON AS HIGH PRESSURE STRETCHES FROM THE OHIO VALLEY TO
THE MID ATLANTIC STATES. MODEL SOUNDINGS DO NOT SHOW MUCH SUPPORT
FOR GUSTY WINDS...AND WINDS LOOK TO REMAIN BELOW RED FLAG CRITERIA.
WHILE A RED FLAG WARNING DOES NOT APPEAR TO BE WARRANTED FOR
TODAY...THE LOW RELATIVE HUMIDITY VALUES AND DRY FINE FUELS DO
WARRANT A SPECIAL WEATHER STATEMENT FOR ENHANCED FIRE DANGER.
SATURDAY NOW APPEARS IT WILL BE ANOTHER DRY AND WINDY DAY, WHICH
WILL CONTINUE ENHANCED FIRE SPREAD CONCERNS.
&&
.CLIMATE...
POTENTIAL FOR NEAR RECORD HEAT MONDAY.
HERE ARE THE RECORD HIGH TEMPERATURES FOR ALL 8 OF OUR CLIMATE SITES
FOR MONDAY AND TUESDAY.
4/16 4/17
ALLENTOWN 89 - 2002 91 - 2002, 1976
ATLANTIC CITY 89 - 2002 94 - 2002
GEORGETOWN 89 - 2002 94 - 2002
MOUNT POCONO 85 - 2002 87 - 2002
PHILADELPHIA 90 - 2002 95 - 2002
READING 88 - 2002 95 - 1976
TRENTON 90 - 2002 93 - 2002
WILMINGTON 92 - 1896 97 - 1896
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR PAZ060-067.
FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR PAZ054-055-061-
062.
NJ...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NJZ008>010-
020>022-027.
FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR NJZ001-007.
DE...NONE.
MD...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MDZ008.
MARINE...NONE.
&&
$$
SYNOPSIS...ROBERTSON
NEAR TERM...HAYES
SHORT TERM...HAYES
LONG TERM...ROBERTSON
AVIATION...HAYES/ROBERTSON
MARINE...HAYES/ROBERTSON
FIRE WEATHER...HAYES/ROBERTSON
CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS WICHITA KS
632 PM CDT SAT APR 14 2012
.AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
CONVECTIVE TRENDS WILL BE THE MAIN ISSUE...WITH STRONG-SEVERE
THUNDERSTORMS IN THE VICINITY OF KSLN AND NOT TOO FAR FROM KHUT AT
START OF FORECAST. WILL CONTINUE WITH VCTS AT KRSL/KICT...AS
TIMING OF STORMS IS A BIT UNCLEAR AND IMPACT IF INCLUDED WOULD BE
SIGNIFICANT. 00-06 UTC WILL LIKELY BE THE MOST ACTIVE AT
KHUT/KICT/KSLN. WITH DRYLINE REMAINING WELL WEST OF THE
AREA...STORMS MAY CONTINUE TO REGENERATE THROUGHOUT THE EVENING. IFR
CONDITIONS...LARGE HAIL AND 50KT+ WINDS WILL BE BRIEFLY POSSIBLE
WITH ANY OF THE SEVERE STORMS. ANTICIPATE DRYLINE SHOULD ENTER THE
AREA AROUND 0700 UTC AND NOT EXIT SOUTHEAST KS UNTIL AFTER 1200
UTC. VERY GUSTY SOUTHWEST WINDS ANTICIPATED BEHIND DRYLINE.
-HOWERTON
&&
.PREV DISCUSSION... /ISSUED 333 PM CDT SAT APR 14 2012/
DISCUSSION...
MAIN FORECAST CONCERN: THIS EVENING AND TONIGHT WILL BE THE MOST
CONCERNING PORTION OF THE FORECAST WITH AMPLIFIED SEVERE THREAT FOR
THE COUNTY WARNING AREA. OTHERWISE...THE ISSUES INCLUDE THE POPS FOR
SUNDAY INTO MONDAY WITH THE LOW PUSHING OUT OF THE AREA AND ANY
POTENTIAL WRAP AROUND.
TONIGHT:
DRYLINE WILL BE EVEN SLOWER TO MOVE ACROSS THE AREA...MOST LIKELY
LATER TONIGHT. HOWEVER CONSIDERABLE INSTABILITY/SHEAR ALREADY IN
PLACE...WITH ISOLATED SEVERE STORMS JUST WEST OF AREA AT THIS
TIME. BELIEVE CONDITIONS ARE SUFFICIENT FOR THESE TO CONTINUE AS
THEY MOVE EAST...WITH WITH SOUTHERN SECTIONS LIKELY HAVING BETTER
INSTABILITY THROUGH SUNSET. GIVEN HODOGRAPHS...SUPERCELLS WITH
TORNADIC POTENTIAL WILL EXIST...WELL INTO THE EVENING. DRYLINE
SHOULD SWEEP ACROSS THE AREA DURING MIDDLE OF THE NIGHT.
TEMPERATURES WILL LIKELY REMAIN QUASI STEADY AHEAD OF THE DRYLINE
GIVEN THE LOW LEVEL MOISTURE AND GRADIENT WINDS. -HOWERTON
SUNDAY:
BETTER ALIGNMENT OF THE SURFACE AND UPPER LEVEL TROUGH WHICH WILL
CONTINUE TO PUSH OFF TO THE NORTHEAST ON SUNDAY. A COLD FRONT WITH
THIS SYSTEM IS ANTICIPATED TO SLIDE THROUGH CENTRAL KANSAS FIRST
THEN THROUGH THE REST OF SOUTH CENTRAL AND SOUTHEAST KANSAS THROUGH
THE DAY. THERE IS CONCERN OF STRONG WINDS AHEAD OF AND BEHIND
FRONTAL PASSAGE WITH SUSTAINED SPEEDS JUST SHY OF WIND ADVISORY
CRITERIA BASED ON CURRENT TRENDS. DECIDED AGAINST ISSUING ANY WIND
HEADLINES RIGHT NOW...BUT THE NEXT FORECAST MAY DECIDE TO GO FORWARD
WITH IT. THERE MAY BE LINGERING SHOWERS AND THUNDERSTORMS WITH THE
EXITING LOW WHICH WILL CONTINUE INTO THE MORNING AND AFTERNOON HOURS
IN SOUTHEAST KANSAS...BUT SEVERE POTENTIAL DOES NOT APPEAR TO BE
HIGH WITH THE MAJOR SOURCES OF INSTABILITY DIMINISHING. DID DECREASE
THE POPS SUNDAY EVENING AND NIGHT AS THE PROGRESSION OF THE SYSTEM
APPEARS TO BE MUCH QUICKER THAN PREVIOUSLY ANTICIPATED.
MONDAY:
A SECONDARY WAVE APPEARS TO BE ASSOCIATED WITH THE UPPER LEVEL AT
500MB THAT WILL SLIDE THROUGH ON MONDAY...YET HIGH PRESSURE AT THE
SURFACE TO 850MB. THERE MAY BE A FEW SHOWERS ASSOCIATED WITH THIS
WAVE PARTICULARLY IN CENTRAL AND POTENTIALLY SOUTH CENTRAL KANSAS.
PV DOES INDICATE A PIECE ENERGY MOVING WITH THIS SYSTEM...HOWEVER
MODELS VARY IN LOCATION AND DEVELOPMENT OF ANY PRECIPITATION. THUS
DECIDED TO WAIT ON CHANCES FOR NOW.
TUESDAY TO SATURDAY:
THE NEXT TROUGH WILL START TO DO MOST OF ITS DEVELOPMENT WHEN IT
MOVES OVER THE ROCKIES FOR WEDNESDAY TO THURSDAY...HOWEVER 850MB
INDICATES THE MAIN SYSTEM TO STAY IN THE NORTHERN PLAINS. AT THE
SURFACE...THERE IS INDICATION OF THE LOW PASSING THROUGH ON THURSDAY
WITH SOME ASSOCIATED INSTABILITY FOR THE AFTERNOON AND EVENING
HOURS. THUS KEPT THUNDERSTORM CHANCES IN FOR THIS TIME FRAME.
MOVEMENT OF THIS NEXT TROUGH IN THIS EXTENDED IS A BIT QUESTIONABLE
WITH MODEL VARIATION IN THE TIMING...DEPTH AND EXACT LOCATION. THIS
COULD CHANGE ANY POTENTIAL IN POPS. TEMPERATURES ARE ON TRACK TO
CLIMB TO NEAR TO ABOVE NORMAL WITH THURSDAY LOOKING TO BE THE
WARMEST DAY OF THE WEEK WITH THE GOOD SURGE OF WARM AIR ADVECTION
OUT AHEAD OF THE NEXT SYSTEM.
VP
PREV DISCUSSION... /ISSUED 242 PM CDT SAT APR 14 2012/
UPDATE...
12 UTC AND LATER RUC MODEL RUNS SUGGEST DRYLINE WILL BE EVEN SLOWER
TO MOVE ACROSS THE AREA...MOST LIKELY LATER TONIGHT. THIS WILL
IMPACT SEVERE THREAT ACROSS THE AREA. AT THIS TIME...BEST
INSTABILITY/WEAKEST CAP IS OCCURRING ACROSS WESTERN SECTIONS OF
CENTRAL KS WITH CAP HOLDING ON ACROSS MOST OF SOUTH CENTRAL/
SOUTHEAST KS. GIVEN LACK OF SURFACE BOUNDARY AND EXTENSIVE CLOUDS
SO FAR...MAY BE TOUGH TO BREAK CAP ACROSS SOUTH CENTRAL KS THIS
AFTERNOON. HOWEVER A FEW SMALL BREAKS IN CLOUDS ARE EVIDENT IN
VISIBILITY SATELLITE SOUTH/WEST OF ICT. IF STORMS CAN DEVELOP IN
THIS AREA...CLEARLY ENVIRONMENT WOULD BE CONDUCIVE FOR STRONG/
SEVERE STORMS. BIGGEST THREAT TONIGHT IS ROUGHLY ALONG AND SOUTH
OF HIGHWAY 400 ACROSS SOUTH CENTRAL KS...EAST TO HIGHWAY 99 IN
THE 00-04 UTC TIME FRAME...WITH INCREASING ELEVATED STORM RISK
03-06 UTC ACROSS CENTRAL KS EAST OF I-135. -HOWERTON
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
CONVECTIVE TRENDS WILL BE THE MAIN ISSUE...WITH STRONG-SEVERE
THUNDERSTORMS IN THE VICINITY OF KRSL AT START. ISOLATED-SCATTERED
RAIN SHOWERS/THUNDERSTORMS WILL BE POSSIBLE DURING THE AFTERNOON AT
KSLN/KHUT/KICT...BUT EXPECT COVERAGE/INTENSITY TO RAMP UP TOWARDS
0000 UTC...WITH 0000 UTC-06 UTC THE MOST ACTIVE AT KHUT/KICT/KSLN.
IFR CONDITIONS...LARGE HAIL AND 50KT+ WINDS WILL BE BRIEFLY
POSSIBLE WITH ANY OF THE SEVERE STORMS. DRYLINE SHOULD ENTER THE
AREA LATER TONIGHT...BRINGING END TO PRECIPITATION AND LOSS OF
CEILING. GUSTY SOUTHWEST WINDS ANTICIPATED BEHIND DRYLINE.
-HOWERTON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 55 71 44 66 / 60 10 0 10
HUTCHINSON 52 69 44 66 / 50 10 0 10
NEWTON 54 70 45 65 / 60 10 10 10
ELDORADO 57 71 45 67 / 70 10 10 10
WINFIELD-KWLD 57 72 45 69 / 60 10 10 10
RUSSELL 48 63 39 64 / 50 20 10 20
GREAT BEND 49 64 39 64 / 60 20 10 20
SALINA 52 69 43 65 / 60 10 10 20
MCPHERSON 52 69 44 65 / 60 10 10 10
COFFEYVILLE 65 74 47 68 / 50 50 10 10
CHANUTE 63 73 47 67 / 50 50 10 10
IOLA 63 72 47 66 / 50 50 10 10
PARSONS-KPPF 64 73 47 68 / 50 50 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 10 PM CDT THIS EVENING FOR KSZ032-033-
047>053-067>070-082-083-091>094-098.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
609 AM CDT FRI APR 13 2012
...AVIATION UPDATE...
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
A SHORTWAVE CONTINUES TO LIFT NORTHEAST THROUGH EASTERN NEB. WITH
INCREASING SUBSIDENCE BEHIND THIS WAVE...THINK CONVECTION IS OVER
FOR THE REST OF TODAY. THERE DOES NOT APPEAR TO BE ANY ORGANIZED
FORCING FOR NEW CONVECTION UNTIL EARLY SATURDAY MORNING WHEN THE LOW
LEVEL JET NOSES INTO NORTHEAST KS WITH GOOD THETA-E ADVECTION AND
INCREASING ISENTROPIC LIFT. BECAUSE OF THIS INCLUDED A MENTION OF
VCTS LATE IN THE FORECAST PERIOD. OTHERWISE THE LATEST RUC AND NAM
SOUNDINGS ARE IN REASONABLE AGREEMENT IN MIXING OUT THE BOUNDARY
LAYER BETWEEN 17Z AND 19Z. THIS IS IN LINE WITH THE PREV FORECAST OF
SCATTERING OUT THE MVFR STRATUS.
WOLTERS
&&
.PREV DISCUSSION... /356 AM CDT FRI APR 13 2012/
ACTIVE WEATHER IS EXPECTED OVER THE NEXT 48 HOURS...WITH THE
POSSIBILITY OF SEVERE WEATHER TONIGHT...AND A SEVERE WEATHER
OUTBREAK ON SATURDAY AFTERNOON/NIGHT.
TODAY/TONIGHT...UPPER WAVE OBSERVED ON WATER VAPOR HELPING TO
SUPPORT ONGOING THUNDERSTORMS OVER EASTERN KANSAS AND THESE WILL
CONTINUE TO DEVELOP AND MOVE EASTWARD DURING THE EARLY MORNING
HOURS. EXPECT THUNDERSTORMS TO PERSIST OVER ONLY FAR EASTERN AREAS
BY SUNRISE. UPPER WAVE WILL MOVE INTO THE CENTRAL PLAINS THIS
MORNING...WITH SFC WINDS VEERING IN RESPONSE TO ASSOCIATED SFC LOW.
DRYLINE WILL LIKEWISE SHIFT/MIX EASTWARD. BY LATE AFTERNOON...THE
DRYLINE WILL ALIGN FROM HIAWATHA TO TOPEKA TO EMPORIA. WITH
SUBSIDENCE IN THE WAKE OF THIS MORNINGS SHORTWAVE TROUGH...AND ONLY
MARGINAL CONVERGENCE ALONG THE SFC BOUNDARY...CONVECTIVE INITIATION
REMAINS UNCERTAIN FOR THE CWA THIS AFTERNOON/EVENING. NEXT UPPER
WAVE APPROACHES THE HIGH PLAINS BY EARLY EVENING...AND SFC WINDS
WILL QUICKLY RESPOND AND BACK. THIS WILL EFFECTIVELY RETROGRADE THE
DRYLINE WESTWARD PRIOR TO 00Z FROM THE AFOREMENTIONED LOCATION.
CONVECTIVE DEVELOPMENT IS MORE PROBABLE BY LATE AFTERNOON INTO EARLY
EVENING IN AREAS SOUTHWEST OF THE CWA...SPECIFICALLY WESTERN
OKLAHOMA AND FAR SOUTH CENTRAL KANSAS...WHERE BETTER DRYLINE
CONVERGENCE/MIXING AND A CLOSER PROXIMITY TO INCREASING LARGE SCALE
ASCENT. A FEW STORMS MAY TRY TO DEVELOP ALONG THE RETREATING DRYLINE
OVER THE SOUTHWESTERN PORTION OF THE CWA AROUND SUNSET...BUT OVERALL
CONFIDENCE IN COVERAGE IS LOW ATTM. THE MORE LIKELY CONVECTIVE
SCENARIO FOR THE CWA WILL SPAWN FROM THE ANTICIPATED CONVECTION OVER
OKLAHOMA AND FAR SOUTHERN KANSAS. THIS ACTIVITY WILL MOVE
NORTHEASTWARD AND POSSIBLY EVOLVE INTO ONE OR MORE SMALL CLUSTERS.
BASED ON THIS SCENARIO AND THE OUTPUT FROM SEVERAL OPERATIONAL
MODELS...THE BEST CHANCE FOR THUNDERSTORMS WILL BE AFTER 9 PM CDT.
WITH THE EXPECTED EVOLUTION AND ANTICIPATED INSTABILITY LATE IN THE
EVENING...THE OVERALL SEVERE WEATHER THREAT MAY BE TEMPERED
SLIGHTLY. STILL...SEVERE WEATHER IS POSSIBLE ACROSS THE SOUTHERN
HALF OF THE CWA...GENERALLY ALONG AND SOUTH OF INTERSTATE 70. THE
PRIMARY SEVERE WEATHER THREAT WILL BE LARGE HAIL AND DAMAGING WINDS.
AS WITH ANY CONVECTIVE FORECAST...SUBTLE DETAILS REGARDING THE
COVERAGE...LOCATION AND TIMING OF CONVECTIVE INITIATION AND THE
SUBSEQUENT EVOLUTION COULD HAVE A SUBSTANTIAL IMPACT ON THE CURRENT
FORECAST...SO REMAIN ALERT TO RAPIDLY CHANGING WEATHER CONDITIONS
BEGINNING EARLY THIS EVENING INTO THE OVERNIGHT HOURS SATURDAY
MORNING.
SATURDAY/SATURDAY NIGHT...A MAJOR SEVERE WEATHER OUTBREAK IS
EXPECTED TO OCCUR BEGINNING LATE SAT AFTERNOON INTO THE OVERNIGHT
HOURS. A VERY DYNAMIC ENVIRONMENT WILL BE IN PLACE WITH STRONG
INSTABILITY AND IMPRESSIVE LOW LEVEL WIND SHEAR. STORMS THAT
DEVELOP...ESPECIALLY THOSE PRIOR TO MIDNIGHT SUNDAY...WILL HAVE A
GOOD LIKELIHOOD OF BECOMING SUPERCELLS. THESE STORMS WILL BE
CAPABLE OF PRODUCING VERY LARGE HAIL UP TO BASEBALL SIZE AND STRONG
TORNADOES. THE PRIMARY UNCERTAINTY REMAINS TIMING AND COVERAGE OF
CONVECTION ACROSS THE CWA...AND OPERATIONAL MODELS HAVE STRUGGLED
WITH RESOLVING CONVECTIVE OUTPUT. THE INITIAL THUNDERSTORMS WILL
LIKELY DEVELOP ALONG A DRYLINE OVER THE FAR WESTERN SECTIONS OF THE
CWA. ADDITIONAL STORMS MAY DEVELOP IN ADVANCE OF THIS BOUNDARY IN
THE WARM SECTOR AS THE ATMOSPHERE BECOMES UNCAPPED. STORMS ARE
EXPECTED TO PERSIST AND RETAIN MUCH OF THEIR ORGANIZATION AND
STRENGTH WELL AFTER DARK. WITH THE LOW LEVEL WIND FIELD INCREASING
NEAR/AFTER SUNSET...THE POSSIBILITY OF NIGHTTIME TORNADOES IS HIGH.
RESIDENTS ARE URGED TO PREPARE FOR THE POTENTIAL OF A WIDESPREAD
SEVERE WEATHER OUTBREAK...WHICH INCLUDES NIGHTTIME STRONG TORNADOES
SATURDAY NIGHT.
SUNDAY/BEYOND...THUNDERSTORMS WILL BE ONGOING OVER THE FAR EASTERN
SECTIONS OF THE CWA BY 12Z SUN. THE DRYLINE WILL QUICKLY EXIT THE
STATE PRIOR TO 18Z...ENDING THE SEVERE WEATHER THREAT FOR THE AREA.
DRY WEATHER IS CURRENTLY FORECASTED FOR THE REMAINDER OF THE
FORECAST PERIOD.
BLAIR
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
733 PM EDT SAT APR 14 2012
.UPDATE...
ISSUED AT 730 PM EDT SAT APR 14 2012
SEVERAL UPDATES WERE MADE TO THE TONIGHT PERIOD OF THE FORECAST. THE
LATEST SATELLITE AND RADAR IMAGERY REVEALED THAT RAIN SHOWER
ACTIVITY HAS LONG SINCE EXITED EASTERN KENTUCKY AND MOVED INTO WEST
VIRGINIA. SKIES ARE CLEAR OR MOSTLY CLEAR ACROSS THE MAJORITY OF THE
FORECAST AREA AT THIS TIME AS WELL. WITH NO AREAS OF PRECIPITATION
UPSTREAM THAT WILL AFFECT THE AREA...AND WITH ALL OF THE FORECAST
MODELS HAVING NO PRECIPITATION IN THE AREA EITHER...DECIDED TO REMOVE
PRECIPITATION FROM THE FORECAST FOR THE REMAINDER OF THE EVENING AND
OVERNIGHT PERIOD. THE SKY COVER FORECAST WAS ALSO ADJUSTED TO REFLECT
VERY LITTLE CLOUD COVER OVERNIGHT AS WELL. A FEW HIGH CLOUDS LEFT
OVER FROM THE STORMS THAT ARE CURRENTLY MOVING ACROSS THE CENTRAL
PLAINS COULD MOVE OVERHEAD LATER TONIGHT...BUT NOT ENOUGH CLOUD COVER
WILL BE IN THE AREA TO WARRANT MORE THAN MOSTLY CLEAR SKIES TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 303 PM EDT SAT APR 14 2012
WE CONTINUE TO TRACK THE THREE MCS MOVING ACROSS THE OH VALLEY. THE
FIRST IS NOW OVER SE OH AND NE KY...AND HAS PASSED OUR FORECAST AREA.
THIS ONE CLIPPED THE NORTHERN PART OF OUR FORECAST AREA...WITH 0.02
INCHES OF RAIN AT THE BATH COUNTY AND ROWAN COUNTY MESONET SITES AND
0.08 INCHES AT THE FAIRVIEW IFLOWS SITE IN FLEMING COUNTY.
THE NEXT SYSTEM IN LINE NOW OVER SW OH...SE IN AND N KY MAY ALSO
AFFECT OUR FAR NORTHERN COUNTIES BETWEEN 20Z AND 22Z. THE TOPS OF
THIS MCS HAVE BEEN WARMING...LIGHTING HAS BEEN DECREASING...AS HAS
RADAR REFLECTIVITY. LATEST RADAR TRENDS SHOW THIS MAY ONLY CLIP
NORTHERN FLEMING COUNTY...SO ANY RAIN WILL LIKELY AFFECT LESS OF OUR
AREA THAN THE PREVIOUS SHOWERS.
THE REMNANTS OF THE THIRD MCS ARE OVER IL...AND THIS SYSTEM ALSO
DECREASING AT THIS TIME. BASED ON LATEST RADAR AND SATELLITE
TRENDS WILL ONLY CARRY THUNDER CHANCES FOR A COUPLE MORE HOURS IN THE
NORTH...THEN JUST GO ISOLATED SHOWERS IN THE FAR NORTH INTO THE
EARLY EVENING.
HEIGHTS WILL BE RISING AS THE UPPER RIDGE EXTENDING FROM THE GULF OF
MEXICO NORTH THROUGH THE OH VALLEY AMPLIFIES IN RESPONSE TO THE UPPER
LOW EMERGING FROM THE SOUTHERN ROCKIES. AT THE SURFACE THE WARM FRONT
DRAPED ACROSS THE LOWER OH VALLEY WILL MOVE NORTH...AND THE THREAT
OF CONVECTION WILL ALSO SHIFT NORTH...WITH ANY SHOWER CHANCES ONLY IN
THE FAR NORTH EARLY THIS EVENING.
ALL SHORT RANGE MODEL GUIDANCE IS IN AGREEMENT WITH THIS SCENARIO.
THE HRRR IS STILL TRYING TO BRING SOME SHOWERS ACROSS THE NORTHERN
PART OF OUR FORECAST AREA LATER THIS EVENING...BUT THIS IS NOT IN
AGREEMENT WITH CURRENT RADAR TRENDS AND LATEST MODEL GUIDANCE.
TEMPERATURES WILL WARM CONSIDERABLY ON SUNDAY AS RIDGE BUILDS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 303 PM EDT SAT APR 14 2012
THIS FORECAST BEGINS WITH AN APPROACHING 50H SHORT WAVE PUSHING
AGAINST A SUBSTANTIAL BERMUDA HIGH. THE HIGH PRESSURE WILL SLOW THE
PROGRESSION OF THE SHORT WAVE EVEN AS IT BEGINS TO FLATTEN THE HIGH.
LOOK FOR THE SHORT WAVE TO SPLIT AS IT APPROACHES THE ERN GREAT
LAKES WITH THE SRN PORTION REMAINING IN ERN TX. THIS WILL ELONGATE
THE ENERGY AND WEAKEN IT AS IT PASSES THRU ERN KY. STILL EXPECTING
LIKELY TSRA WITH THE FRONTAL PASSAGE ON MON AND EARLY MON NITE. THEN
THE ENERGY LEFT IN TX WILL FORM A SFC LOW IN THE WRN GULF AND SLOWLY
EDGE EAST WHILE CONTINUING TO PUSH WARM AND MOIST AIR INTO THE TN
VALLEY. THIS WILL KEEP THE THREAT FOR SCT SHRA/TSRA IN THE AREA BUT
HIGH PRESSURE BUILDING DOWN FROM THE GREAT LAKES SHOULD KEEP ANY
RAIN SOUTH OF THE KY/TN STATE LINE. MODELS INDICATE THAT THE FRONTAL
BNDRY WILL HANG UP ON THE SERN ATLANTIC COAST BUT EAST OF THE
APPALACHIAN MTNS FOR THE LATE WEEK PERIOD. THIS EVEN AS THE NEXT
WAVE FORMS ON THE LEE SIDE OF THE ROCKIES AND MOVES INTO THE CNTRL
PLAINS BY FRI. THIS WAVE WILL CROSS THE GREAT LAKES FRI NITE/SAT IN
A FASTER ZONAL FLOW AND DRAG ANOTHER FRONT THRU THE COMMONWEALTH
PROVIDING THE NEXT CHANCE FOR SCT SHRA/TSRA. TEMPS IN ADVANCE OF THE
STORMS ON MON WILL SOAR TO AROUND 80 BEFORE DROPPING INTO THE UPPER
50S MON NITE. THEN THE COOLER AIR WILL KEEP HIGHS ON TUE ONLY IN THE
MID 60S. AS THE ATMOSPHERE RECHARGES WITH THE SRLY INFLOW THRU THE
REST OF THE WEEK... EXPECT TEMPS TO SHOW A WARMING TREND INTO THE
UPPER 60S ON WED...LOWER 70S BY THU AND UPPER 70S FOR THE END OF THE
WORK WEEK. PRECIP ON FRI NIGHT AND SAT WILL ONCE AGAIN HOLD HIGHS TO
THE MID 60S FOR THE START OF THE WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 730 PM EDT SAT APR 14 2012
EARLIER RAIN SHOWERS HAVE ALREADY EXITED THE FORECAST AREA AND NO
ADDITIONAL PRECIPITATION IS ANTICIPATED OVERNIGHT. SKIES ACROSS ALL
OF EASTERN KENTUCKY AREA NOW EITHER CLEAR OR MOSTLY CLEAR. THE TAF
SITES WILL EXPERIENCE VFR CONDITIONS THROUGH THE END OF THE TAF
PERIOD. THE ONE WEATHER CONCERN WILL BE FOR TOMORROW AS GUSTY SOUTH
TO SOUTHWEST WINDS ARE EXPECTED TO DEVELOP AFTER 15Z. THE STRONGEST
WINDS WILL DEVELOP INITIALLY SOUTH OF THE HAL ROGERS PARKWAY IN THE
FLATTER TERRAIN. THE WINDS WILL THEN INCREASE ACROSS THE ENTIRE AREA
DURING THE AFTERNOON AS THE GROUND HEATS UP. GUSTS OF AROUND 20KTS
WILL BE POSSIBLE DURING THE PEAK HEATING OF THE DAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AR
SHORT TERM...SBH
LONG TERM....DUSTY
AVIATION...AR
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1023 PM EDT SAT APR 14 2012
.SYNOPSIS...
ISSUED AT 412 PM EDT SAT APR 14 2012
A WARM FRONT WILL BRING A PERIOD OF THUNDERSTORMS WITH LOCALLY
HEAVY RAINFALL LATE TONIGHT INTO MID MORNING SUNDAY. THE COLD
FRONT MONDAY NIGHT WILL BRING AN PERIOD OF THUNDERSTORMS WITH
GUSTY WINDS WITH IT. NO MONDAY IT WILL BECOME VERY WINDY WITH
FALLING TEMPERATURES DURING THE DAY AS WELL AS SCATTERED SHOWERS.
FROST AND FREEZING TEMPERATURES ARE EXPECTED BY TUESDAY MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 412 PM EDT SAT APR 14 2012
LITTLE CHANGE IN THINKING FROM MY LATE MORNING DISCUSSION. A
PERIOD OF THUNDERSTORMS (NOT SEVERE) WITH THE WARM FRONT
TONIGHT...DRY MIDDAY SUNDAY UNTIL MID EVENING...THEN THE FRONTAL
RAIN BAND WITH GUSTY WINDS LATE EVENING SUNDAY INTO THE EARLY
MORNING HOURS OF MONDAY.
TONIGHT THE LOW LEVEL JET BIFURCATES WITH PART OF IT GOING INTO OHIO
AND THE REST OF IT HEADED TOWARD MN/WI. THAT ALSO IS NOT CONDUCIVE
FOR CONVECTION HERE. IT IS NOT UNTIL MID MORNING SUNDAY THE
SOUTHERN BRANCH OF THE BIFURCATED LOW LEVEL JET EVEN SHOWS A SIGN OF
GETTING INTO THE I-94 REGION AND BY THEN IT IS WEAKENING. THE
PRIMARY CORE STAYS OVER WI/MI/IA THROUGH THE DAY AND SLOWLY
DEVELOPS NORTHWARD NOT EASTWARD. SO I EXPECT A BAND OF
THUNDERSTORMS TO HEAD NORTH THROUGH LOWER MICHIGAN MID MORNING BUT
WILL LIKELY NOT BE SEVERE (NOT SURFACE BASED). THE HRRR RUC FROM
THE 16Z MODEL RUN SHOWS THIS NICELY. SO MOST OF THE RAIN FROM THE
WARM FRONTAL RAIN BAND WILL BE BETWEEN MIDNIGHT AND 10 AM MONDAY.
THE MODELS AND SOUNDING SHOW NO SURFACE BASED CAPE AND ONLY 500 TO
1000 J/KG OF MOST UNSTABLE CAPE (FROM 800 MB LAYER). THUS I DO NOT
SEE MUCH OF SEVERE THREAT TONIGHT WITH THESE STORMS. JUST LOCALLY
HEAVY RAINFALL.
ON SUNDAY THE WARM FRONT LIFTS NORTH OF THE CWA AND SO WILL THE
ASSOCIATED CONVECTION. THERE IS SURFACE BASED INSTABILITY SUNDAY BUT
NO FOCUS SO I DO NOT BELIEVE WE WILL BE SEEING MUCH IF ANY
CONVECTION IN THE GRR CWA DURING THE AFTERNOON. IF THE SUN REALLY
CAME OUT TEMPERATURES COULD REACH 80 SOUTH OF INTERSTATE 96.
SUNDAY NIGHT WILL BE OUR CONVECTIVE "SHOW" IF ONE COULD CALL IT
THAT. IT TAKES UNTIL 2 AM FOR THE LOW LEVEL JET CORE TO GET TO
I-31. WHILE FORECAST SHOWS 1500-2000 J/KG OF SURFACE BASED CAPE
OVER WI SUN AFTERNOON BY THE TIME THIS REACHES LOWER MICHIGAN
AFTER MIDNIGHT IT IS LESS THE 500 J/KG. ON THE OTHER HAND WE DO
STILL HAVE SURFACE BASED CAPE SO AND A 60 TO 70 KNOT LOW LEVEL
JET. GIVEN THE LOW CAPE VALUE LARGE HAIL SEEMS OUT OF THE
QUESTION. MOSTLY GUSTY WINDS BUT WITH WEAK CAPE ONE HAS TO EVEN
WONDER ABOUT THAT. SO I AM NOT EXPECTING A MAJOR SEVERE OUTBREAK
IN OUR CWA FROM THIS EVENT. JUST ISOLATED SEVERE STORMS POSSIBLE
AFTER MIDNIGHT. SPC`S OUTLOOK FOR SUNDAY NIGHT INTO MONDAY AGREES
WITH THIS WITH A 15 PCT CHANCE OVER OUR NW CWA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 412 PM EDT SAT APR 14 2012
TRENDED POPS LOWER FOR MONDAY AND ALSO TRENDED COOLER FOR MONDAY
NIGHT AND TUESDAY NIGHT. MODEL TRENDS ARE MORE PROGRESSIVE WITH
MOVING THE SURFACE LOW OUT OF THE AREA ON MONDAY. THIS SHOULD
RESULT IN QUICKER CLEARING MONDAY NIGHT...AND REMAINING MOSTLY CLEAR
TUESDAY NIGHT WITH HIGH PRESSURE OVER MI. FROST AND FREEZING TEMPS
WILL BE A CONCERN UNDER THIS SCENARIO...ESPECIALLY TUESDAY NIGHT AS
WINDS SHOULD BE LIGHTER.
NEXT CHANCE OF PCPN SHOULD HOLD OFF UNTIL WED AFTERNOON OR EVENING
AS A NORTHERN STREAM WAVE BRINGS A COLD FRONT LATE WED NIGHT OR
EARLY THU. THE FRONT THEN STALLS TO OUR SOUTH WITH OVER-RUNNING
PCPN LINGERING. IT APPEARS THE CWA WILL BE ON THE NORTHERN FRINGE
OF THIS PCPN...SO I HAVE HIGHER POPS IN THE SOUTHERN CWA...AND LOWER
POPS NORTH. THE EURO HOLDS ON TO PCPN RIGHT INTO SAT...BUT THE GFS
GOES DRY. HAVE FAVORED THE DRIER GFS AS THE PATTERN LOOKS MORE
PROGRESSIVE THAN WHAT THE EURO SUGGESTS. TEMPS WILL REMAIN COOL WITH
NE LOW LEVEL FLOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 743 PM EDT SAT APR 14 2012
CEILINGS WILL BE MVFR AT MOST PLACES THROUGH 06Z...WITH A COUPLE
HOURS OF IFR EXPECTED LATER TONIGHT AS SHOWERS AND THUNDERSTORMS
MOVE IN. COULD BE SOME VFR THROUGH SUNDAY AFTERNOON AS THE FIRST
BATCH OF SHOWERS MOVES OFF TO THE NORTH. WINDS WILL BE SOUTH
TONIGHT THEN GO SW SUNDAY MORNING WHILE INCREASING TO 10 TO 20
KNOTS WITH GUSTS OVER 25 KNOTS THROUGH MUCH OF SUNDAY.
&&
.MARINE...
ISSUED AT 1023 PM EDT SAT APR 14 2012
WE DECIDED TO BUMP UP THE TIMING ON THE SMALL CRAFT ADVISORY TO
AROUND 06Z TONIGHT. WINDS ALONG THE LAKESHORE AT THE COASTAL SITES
ARE GENERALLY RUNNING 10 TO 15 KNOTS...WITH BIG SABLE POINT COMING
IN AROUND 20 KNOTS ALREADY. LOW LEVEL WINDS WILL BE
INCREASING...HOWEVER STABLE ENVIRONMENT OVER THE LAKE WILL LIMIT
THE WIND SPEED SOME AT THE SFC. WE STILL THINK THAT THERE WILL BE
ENOUGH OF AN INCREASE TO JUSTIFY THE ADVISORY...AND IT VERY WELL
COULD BEGIN BEFORE 12Z SUN.
&&
.HYDROLOGY...
ISSUED AT 412 PM EDT SAT APR 14 2012
LOCALLY HEAVY RAINFALL IS POSSIBLE TONIGHT WITH THE WARM FRONT
PRECIPITATION BAND MOVING NORTHWARD THROUGH SOUTHWEST LOWER
MICHIGAN. AT THIS POINT THROUGH WE DO NOT SEE A LARGE SCALE GENERAL
HEAVY RAINFALL. MOST LOCATIONS TONIGHT SHOULD GET AROUND A HALF
INCH. THE COLD FRONT RAIN BAND SHOULD NOT BE AS HEAVY...GENERALLY
AROUND A QUARTER INCH. THIS SHOULD NOT CAUSE TO MANY PROBLEMS FOR
OUR RIVERS BUT COULD LOCALLY CAUSE ISSUES ON SMALLER STREAMS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM 2 AM SUNDAY TO 8 AM EDT MONDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...JK
AVIATION...OSTUNO
HYDROLOGY...WDM
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
743 PM EDT SAT APR 14 2012
.SYNOPSIS...
ISSUED AT 412 PM EDT SAT APR 14 2012
A WARM FRONT WILL BRING A PERIOD OF THUNDERSTORMS WITH LOCALLY
HEAVY RAINFALL LATE TONIGHT INTO MID MORNING SUNDAY. THE COLD
FRONT MONDAY NIGHT WILL BRING AN PERIOD OF THUNDERSTORMS WITH
GUSTY WINDS WITH IT. NO MONDAY IT WILL BECOME VERY WINDY WITH
FALLING TEMPERATURES DURING THE DAY AS WELL AS SCATTERED SHOWERS.
FROST AND FREEZING TEMPERATURES ARE EXPECTED BY TUESDAY MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 412 PM EDT SAT APR 14 2012
LITTLE CHANGE IN THINKING FROM MY LATE MORNING DISCUSSION. A
PERIOD OF THUNDERSTORMS (NOT SEVERE) WITH THE WARM FRONT
TONIGHT...DRY MIDDAY SUNDAY UNTIL MID EVENING...THEN THE FRONTAL
RAIN BAND WITH GUSTY WINDS LATE EVENING SUNDAY INTO THE EARLY
MORNING HOURS OF MONDAY.
TONIGHT THE LOW LEVEL JET BIFURCATES WITH PART OF IT GOING INTO OHIO
AND THE REST OF IT HEADED TOWARD MN/WI. THAT ALSO IS NOT CONDUCIVE
FOR CONVECTION HERE. IT IS NOT UNTIL MID MORNING SUNDAY THE
SOUTHERN BRANCH OF THE BIFURCATED LOW LEVEL JET EVEN SHOWS A SIGN OF
GETTING INTO THE I-94 REGION AND BY THEN IT IS WEAKENING. THE
PRIMARY CORE STAYS OVER WI/MI/IA THROUGH THE DAY AND SLOWLY
DEVELOPS NORTHWARD NOT EASTWARD. SO I EXPECT A BAND OF
THUNDERSTORMS TO HEAD NORTH THROUGH LOWER MICHIGAN MID MORNING BUT
WILL LIKELY NOT BE SEVERE (NOT SURFACE BASED). THE HRRR RUC FROM
THE 16Z MODEL RUN SHOWS THIS NICELY. SO MOST OF THE RAIN FROM THE
WARM FRONTAL RAIN BAND WILL BE BETWEEN MIDNIGHT AND 10 AM MONDAY.
THE MODELS AND SOUNDING SHOW NO SURFACE BASED CAPE AND ONLY 500 TO
1000 J/KG OF MOST UNSTABLE CAPE (FROM 800 MB LAYER). THUS I DO NOT
SEE MUCH OF SEVERE THREAT TONIGHT WITH THESE STORMS. JUST LOCALLY
HEAVY RAINFALL.
ON SUNDAY THE WARM FRONT LIFTS NORTH OF THE CWA AND SO WILL THE
ASSOCIATED CONVECTION. THERE IS SURFACE BASED INSTABILITY SUNDAY BUT
NO FOCUS SO I DO NOT BELIEVE WE WILL BE SEEING MUCH IF ANY
CONVECTION IN THE GRR CWA DURING THE AFTERNOON. IF THE SUN REALLY
CAME OUT TEMPERATURES COULD REACH 80 SOUTH OF INTERSTATE 96.
SUNDAY NIGHT WILL BE OUR CONVECTIVE "SHOW" IF ONE COULD CALL IT
THAT. IT TAKES UNTIL 2 AM FOR THE LOW LEVEL JET CORE TO GET TO
I-31. WHILE FORECAST SHOWS 1500-2000 J/KG OF SURFACE BASED CAPE
OVER WI SUN AFTERNOON BY THE TIME THIS REACHES LOWER MICHIGAN
AFTER MIDNIGHT IT IS LESS THE 500 J/KG. ON THE OTHER HAND WE DO
STILL HAVE SURFACE BASED CAPE SO AND A 60 TO 70 KNOT LOW LEVEL
JET. GIVEN THE LOW CAPE VALUE LARGE HAIL SEEMS OUT OF THE
QUESTION. MOSTLY GUSTY WINDS BUT WITH WEAK CAPE ONE HAS TO EVEN
WONDER ABOUT THAT. SO I AM NOT EXPECTING A MAJOR SEVERE OUTBREAK
IN OUR CWA FROM THIS EVENT. JUST ISOLATED SEVERE STORMS POSSIBLE
AFTER MIDNIGHT. SPC`S OUTLOOK FOR SUNDAY NIGHT INTO MONDAY AGREES
WITH THIS WITH A 15 PCT CHANCE OVER OUR NW CWA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 412 PM EDT SAT APR 14 2012
TRENDED POPS LOWER FOR MONDAY AND ALSO TRENDED COOLER FOR MONDAY
NIGHT AND TUESDAY NIGHT. MODEL TRENDS ARE MORE PROGRESSIVE WITH
MOVING THE SURFACE LOW OUT OF THE AREA ON MONDAY. THIS SHOULD
RESULT IN QUICKER CLEARING MONDAY NIGHT...AND REMAINING MOSTLY CLEAR
TUESDAY NIGHT WITH HIGH PRESSURE OVER MI. FROST AND FREEZING TEMPS
WILL BE A CONCERN UNDER THIS SCENARIO...ESPECIALLY TUESDAY NIGHT AS
WINDS SHOULD BE LIGHTER.
NEXT CHANCE OF PCPN SHOULD HOLD OFF UNTIL WED AFTERNOON OR EVENING
AS A NORTHERN STREAM WAVE BRINGS A COLD FRONT LATE WED NIGHT OR
EARLY THU. THE FRONT THEN STALLS TO OUR SOUTH WITH OVER-RUNNING
PCPN LINGERING. IT APPEARS THE CWA WILL BE ON THE NORTHERN FRINGE
OF THIS PCPN...SO I HAVE HIGHER POPS IN THE SOUTHERN CWA...AND LOWER
POPS NORTH. THE EURO HOLDS ON TO PCPN RIGHT INTO SAT...BUT THE GFS
GOES DRY. HAVE FAVORED THE DRIER GFS AS THE PATTERN LOOKS MORE
PROGRESSIVE THAN WHAT THE EURO SUGGESTS. TEMPS WILL REMAIN COOL WITH
NE LOW LEVEL FLOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 743 PM EDT SAT APR 14 2012
CEILINGS WILL BE MVFR AT MOST PLACES THROUGH 06Z...WITH A COUPLE
HOURS OF IFR EXPECTED LATER TONIGHT AS SHOWERS AND THUNDERSTORMS
MOVE IN. COULD BE SOME VFR THROUGH SUNDAY AFTERNOON AS THE FIRST
BATCH OF SHOWERS MOVES OFF TO THE NORTH. WINDS WILL BE SOUTH
TONIGHT THEN GO SW SUNDAY MORNING WHILE INCREASING TO 10 TO 20
KNOTS WITH GUSTS OVER 25 KNOTS THROUGH MUCH OF SUNDAY.
&&
.MARINE...
ISSUED AT 412 PM EDT SAT APR 14 2012
IF NOT FOR THE COLD LAKE AND WARM AIR WE WOULD HAVE A GALE WARNING
FOR SUNDAY INTO SUNDAY NIGHT HOWEVER WITH LAKE TEMPERATURES IN THE
LOWER 40S AND AIR TEMPERATURES COMING OFF ILLINOIS AND INDIANA IN
THE 70S SUNDAY THE WINDS WILL NOT MIX THROUGH THE MARINE LAYER.
THAT CHANGES MONDAY ONCE THE STRONG COLD FRONT COMES THROUGH. WE
MAY NEED GALES THEN...FOR NOW I AM GOING WITH A SMALL CRAFT
ADVISORY SUNDAY INTO MIDDAY MONDAY AND CALLING THAT GOOD.
&&
.HYDROLOGY...
ISSUED AT 412 PM EDT SAT APR 14 2012
LOCALLY HEAVY RAINFALL IS POSSIBLE TONIGHT WITH THE WARM FRONT
PRECIPITATION BAND MOVING NORTHWARD THROUGH SOUTHWEST LOWER
MICHIGAN. AT THIS POINT THROUGH WE DO NOT SEE A LARGE SCALE GENERAL
HEAVY RAINFALL. MOST LOCATIONS TONIGHT SHOULD GET AROUND A HALF
INCH. THE COLD FRONT RAIN BAND SHOULD NOT BE AS HEAVY...GENERALLY
AROUND A QUARTER INCH. THIS SHOULD NOT CAUSE TO MANY PROBLEMS FOR
OUR RIVERS BUT COULD LOCALLY CAUSE ISSUES ON SMALLER STREAMS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM 8 AM SUNDAY TO 8 AM EDT MONDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...JK
AVIATION...OSTUNO
HYDROLOGY...WDM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
418 PM EDT FRI APR 13 2012
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 417 PM EDT FRI APR 13 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW MID/UPPER LEVEL TROF OVER
THE WRN CONUS WITH DOWNSTREAM RIDGE FROM THE WRN GULF TO THE WRN
LAKES. VIGOROUS LOOKING SHORTWAVE WAS LIFTING NNE THRU SW MN.
DESPITE VIGOROUS LOOK...SHRA AHEAD OF FEATURE HAVE BEEN WEAKENING AS
THEY MOVE E INTO THE VERY DRY AIRMASS ASSOCIATED WITH RIDGE PER 12Z
KGRB SOUNDING. THIS TREND WILL LIKELY CONTINUE AS SHORTWAVE
PROGRESSES INTO THE MEAN RIDGE POSITION...ESPECIALLY WITH 850MB FLOW
VEERING MORE WRLY AND MOISTURE TRANSPORT WEAKENING WITH TIME. SHRA
CURRENTLY DEVELOPING AROUND VORT MAX IN SW MN MAY BRUSH THE NW FCST
AREA DURING THE NIGHT. AT THIS POINT...IT DOESN`T LOOK LIKE ANYTHING
HIGHER THAN CHC/SCT POPS ARE WARRANTED. WHERE PCPN OCCURS...AMOUNTS
WILL BE LIGHT...UNDER 0.1 INCHES.
SAT...ANY LINGERING SCT PCPN OVER THE NRN AND ERN FCST AREA WILL
MOVE OUT DURING THE MORNING AS DRY SLOT UNDERNEATH UPPER LEVEL JET
STREAK SHIFTS OVER THE AREA. DRYING COLUMN AND TREND TO MOSTLY SUNNY
SHOULD ALLOW FOR DEEP MIXING TO AT OR ABOVE 800MB SAT AFTN. PER FCST
SOUNDINGS...THIS WILL ALLOW TEMPS TO RISE TO AROUND 70F AWAY FROM
MARINE INFLUENCES. MIXING WILL HELP DWPTS FALL IN THE AFTN. IF
MIXING HEIGHTS ARE A LITTLE HIGHER THAN EXPECTED...DWPTS WILL FALL
SEVERAL DEGREES MORE THAN REFLECTED IN THIS FCST ISSUANCE. AS IT IS
NOW...HAVE RH FALLING TO AROUND 30PCT. WITH GUSTY WSW WINDS...THERE
WILL BE AN ELEVATED RISK OF WILDFIRES SAT AFTN...ESPECIALLY OVER THE
W HALF WHERE TEMPS/WINDS WILL BE HIGHEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 417 PM EDT FRI APR 13 2012
MAIN ISSUE FOR THE LONG TERM PERIOD IS THE SUNDAY/MONDAY TIME
FRAME AS DEEP WESTERN TROUGHS HEADS EAST INTO THE LARGE RIDGE
OVR THE EASTERN CONUS. SHORTWAVE TROUGH CURRENTLY BRINGING RAIN
AND TSRA TO SOUTHERN CALIFORNIA IS FCST TO DIG INTO FOUR CORNERS
AREA ON SATURDAY THEN LIFT INTO THE UPPER MISSISSIPPI RIVER VALLEY
BY LATER SUNDAY. IN THE LOW-LEVELS SFC-H85 LOWS FORM OVER SOUTHERN
PLAINS WHILE WARM FRONT BULGES AS FAR NORTH AS NEB AND IA BY
SATURDAY EVENING. POSITIVES FOR PRECIPITATION ON SATURDAY NIGHT IS
FACT THAT UPR MI IS WITHIN BROAD AREA OF DIVERGENCE ALOFT DUE TO JET
STREAK LIFTING ACROSS ONTARIO AND ANOTHER NOSING IN FM THE SOUTHERN
PLAINS. H85 THETA-E ADVECTION ALSO FCST TO ROLL ACROSS UPR LAKES.
WHILE THIS AND THE DIVERGENCE ALOFT MAY HELP TRIGGER AT LEAST SCT
SHOWERS...EXPECT BETTER RAIN CHANCES OVER SOUTH AND EAST CWA CLOSER
TO MAXIMUM H85-H7 MOISTURE TRANSPORT. PTYPE THIS FIRST BATCH OF
PRECIP STRICTLY RAIN AS H85 TEMPS ARE AOA +5C AND SFC DWPNTS REMAIN
AOA 40F. PROBABLY WILL BE A BREAK IN SHOWERS LATE SATURDAY NIGHT
INTO SUN MORNING...BUT GIVEN PERSISTENT H85 THETA-E ADVECTION AND
THAT UPR JET FORCING STILL AROUND FCST WILL KEEP BROADBRUSHED CHANCE
POPS.
LATER SUNDAY...ATTN IS SQUARELY ON APPROACHING DEEP SHORTWAVE TROUGH
LIFTING INTO VCNTY OF NORTHEAST NEB INTO SOUTHWEST MN. SFC LOW FCST
TO PUSH INTO WCNTRL WI BY AFTN WHILE WARM FRONT ATTM IS FCST TO LIFT
INTO NORTHERN WI AND PERHAPS SCNTRL UPR MI. TREND FM LATEST MODELS
IS FOR 12Z NAM/GFS TO BRING SFC LOW NEAR IMT BY 00Z. GIVEN SE WINDS
OFF LK MICHIGAN WOULD EXPECT THE WARM FRONT TO STRUGGLE ANY FARTHER
NORTH AND EAST. CONVECTION SHOULD BE ONGOING AND/OR RE-DEVELOPING
SUNDAY AFTN AHEAD OF PRE-FRONTAL DRY LINE SLIDING ACROSS SOUTHERN
MN INTO IA. SW H85-H7 WINDS WILL ADVECT CONVECTION INTO CWA LATER
IN THE DAY WITH INCREASING POTENTIAL OF SEVERE STORMS IF THE WARM
FRONT IS INDEED OVR NORTHERN WI/SOUTH CNTRL UPR MI GIVEN STEEP H7-H5
LAPSE RATES AOA 7C/KM JUST UPSTREAM. ALL EVENTS ARE DIFFERENT...BUT
SHOULD NOTE THAT THE UPR LEVEL AND MSLP/T/TD PATTERN LOOK SOMEWHAT
SIMILAR TO 10 APRIL 2011 WHEN A COUPLE CLUSTERS OF SEVERE STORMS
IMPACTED PORTIONS OF NORTHERN WISCONSIN AND SOME HAIL AFFECTED
PORTIONS OF CWA. SVR THREAT FOR CWA WILL LARGELY DEPEND ON HOW FAR
NORTH WARM FRONT MAKES IT.
THIS IS DYNAMIC/SPRING PATTERN FOR SURE. 24-HOURS AGO IT LOOKED MAIN
IMPACT FM THE SYSTEM WOULD BE ACCUMULATING SNOW SUNDAY NIGHT INTO
MONDAY. NOW...THERE COULD BE SEVERE WX SUNDAY THEN POSSIBILITY OF
SNOW LATE SUNDAY NIGHT AND MONDAY MORNING. FARTHER NORTH TRACK TO
SFC LOW WOULD DELAY THE CHANGEOVER TO SNOW UNTIL AFTER MIDNIGHT OVER
ONLY THE FAR WEST PORTION OF UPR MI. ALSO...THE FARTHER NORTH H85
BAROCLINIC ZONE RESULTS IN FARTHER NORTH DEFORMATION PRECIPITATION
AREA...SO MODELS HAVE TRENDED LESS WITH PRECIPITATION OVERNIGHT
SUNDAY NIGHT WHEN THE CHANGEOVER TO SNOW WOULD OCCUR. BLEND OF
LATEST GFS/ECMWF/CANADIAN WOULD POINT TO A FEW INCHES OF SNOW
POSSIBLE IN THE WEST AND MAYBE NORTH CENTRAL CWA LATER SUNDAY NIGHT
INTO MONDAY MORNING. FINAL VERDICT WITH SPECIFICS OF THE SYSTEM ARE
FAR FM IN...SO WILL ONLY TWEAK FCST GIVEN THE LATEST MODEL TRENDS.
WILL CONTINUE TO MENTION ACCUMULATING SNOW IN HWO. ALSO WILL PUT A
MENTION OF STORMS AND POSSIBLE HAIL FOR SUNDAY.
IN THE EXTENDED...ONCE LOW BLOWS BY UPR LAKES...A DRY AND CHILLY
PATTERN IS EXPECTED TUESDAY INTO WEDNESDAY MORNING AS HIGH PRESSURE
DRIFTS ACROSS ONTARIO AND UPR GREAT LAKES. NEXT CHANCE OF RAIN
ARRIVES LATER WEDNESDAY AS SHORTWAVE AND SFC TROUGH PRESS INTO UPR
GREAT LAKES IN INCREASINLY QUICK WNW FLOW ALOFT. ANOTHER COUPLE
DISTURBANCES COULD BRING MORE PRECIPITATION BACK TO THE UPR LAKES
THURSDAY INTO FRIDAY AS WELL THOUGH TIMING IS STILL UNCERTAIN.
CONSENESUS GIVES 20-30 POPS FOR NOW WHICH IS FINE. CORE OF COOLER
AIR LURKING JUST NORTH OF LK SUPERIOR LATE IN THE WEEK COULD LEAD TO
RAIN/SNOW WITH THE SYSTEMS AS THEY MOVE THOUGH DEPENDING ON TIME OF
DAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 134 PM EDT FRI APR 13 2012
VFR CONDITIONS WILL CONTINUE THRU THE AFTN HRS AT KIWD/KCMX/KSAW AS
VERY DRY AIRMASS LINGERS OVER THE AREA. LOW PRES SYSTEM LIFTING THRU
MN INTO NRN ONTARIO TONIGHT AND SAT WILL BRING A FEW SHRA TO THE
AREA TONIGHT. PCPN SHOULD BE LIGHT AND NOT DROP VIS BLO VFR AS
SYSTEM WILL BE WEAKENING WITH TIME. HOWEVER...LOW-LEVEL MOISTURE IS
MOVING NE PER OBS/SATELLITE AND SHOULD RESULT IN CIGS DROPPING TO
MVFR TONIGHT. ON SAT...DRYING OF THE COLUMN UNDERNEATH UPPER JET
STREAK WILL RESULT IN IMPROVEMENT TO VFR IN THE MORNING HRS. WINDS
WILL BE GUSTY SAT...ESPECIALLY AT KCMX UNDER A MORE FAVORABLE WRLY
FLOW THERE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 PM EDT FRI APR 13 2012
SOUTHEASTERLY WINDS WILL BE IN THE 15-25KT RANGE AT TIMES OVER MUCH
OF LAKE SUPERIOR TONIGHT AS LOW PRES LIFTS FROM THE ERN DAKOTAS TO
NRN ONTARIO. MIGHT SEE GUSTS AROUND 30KT AT THE HIGHEST OBSERVING
PLATFORMS. AS THE LOW MOVES TO NRN ONTARIO SAT...WINDS WILL SHIFT
AROUND TO THE SW...FAVORING THE W HALF OF LAKE SUPERIOR FOR STRONGER
WINDS...AGAIN INTO THE 15-25KT RANGE AT TIMES. MIGHT SEE SOME GUSTS
TO AROUND 30KT AT THE HIGHEST OBSERVING PLATFORMS THRU ABOUT MID
AFTN DUE TO FAVORABLE ISALLOBARIC COMPONENT. BTWN SYSTEMS...THERE
WILL BE A BRIEF PERIOD OF LIGHTER WINDS UNDER 15KT SAT NIGHT.
ATTENTION THEN TURNS TO THE NEXT LOW PRES SYSTEM THAT WILL MOVE ENE
FROM THE CNTRL PLAINS LATE SAT NIGHT. NE WINDS MAY REACH GALE FORCE
LATE SUN ACROSS W AND CNTRL LAKE SUPERIOR ON THE NW FLANK OF THE LOW
MOVING THRU THE GREAT LAKES. GALES SHOULD THEN SHIFT TO ERN LAKE
SUPERIOR EARLY MON AS WINDS BACK TO THE N BEHIND THE DEPARTING LOW.
WINDS WILL DROP BACK UNDER 20KT TUE AS HIGH PRES ARRIVES...AND THE
LIGHTER WINDS SHOULD LINGER INTO WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
135 PM EDT FRI APR 13 2012
.SYNOPSIS...
ISSUED AT 453 AM EDT FRI APR 13 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH OVER
THE WRN CONUS AND A DOWNSTREAM RIDG FROM ERN TX INTO THE UPPER MS
VALLEY. A VIGOROUS SHORTWAVE TROUGH OVER WRN KS WAS LIFTING NE. AT
THE SFC...SE FLOW WAS INCREASING OVER MN AND WRN WI BTWN HIGH PRES
OVER LAKE HURON AND A TROUGH OVER THE PLAINS. IR LOOP SHOWED HIGH
CLOUDS EXPANDING INTO WRN UPPER MI ASSOCIATED WITH THE DEVELOPING
WAA PATTERN TO THE WEST.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 453 AM EDT FRI APR 13 2012
TODAY INTO TONIGHT...
HIGH AND MID CLOUDS WILL CONTINUE TO SPREAD INTO THE CWA. THE CLOUDS
SHOULD BE THIN ENOUGH TO ALLOW PLENTY OF SUNSHINE AND DECENT MIXING
ALONG WITH WAA TO PUSH TEMPS INTO UPPER 50S AND LOWER 60S. THIS
SHOULD ALSO KEEP DEWPOINTS IN THE LOWER 20S OVER MUCH OF THE
AREA...RESULTING IN RH VALUES IN THE 20 TO 25 PERCENT RANGE. THE DRY
AIR COMBINED WITH SOUTH WINDS OF 10 TO 20 MPH WILL LEAD TO ELEVATED
FIRE WX RISK. SO...WL CONTINUE TO HIGHLIGHT THE HAZARD WITH THE
WILDFIRE POTENTIAL STATEMENT.
MDLS SUGGEST THAT AS THE PLAINS SHRTWV LIFTS INTO THE UPPER MS
VALLEY AND WRN LAKE SUPERIOR...MODERATE 700-500 MB QVECTOR CONV...
WAA/ISENTROPIC LIFT ALONG WITH FAVORABLE MOISTURE TRANSPORT WILL
PRODUCE SCT/NMRS SHRA. MODELS CONTINUED WITH THE TREND TOWARD A
LATER ARRIVAL OF PCPN INTO THE WEST BUT THEN MOVE THE BAND QUICKLY THROUGH
THE WEST IN THE EVENING. EXPECT THE GREATEST PCPN COVERAGE/POPS OVER
THE NW HALF OF THE CWA...CLOSER TO THE PATH OF THE SHRTWV AND UPPER
LEVEL DIV WITH THE LEFT EXIT REGION OF THE 250-300 MB JET. SINCE THE
DYNAMICS MOVE INTO THE DRY AIRMASS FAIRLY QUICKLY ...ONLY LIGHT PCPN
AMOUNTS OF A TENTH OF AN INCH OR LESS ARE EXPECTED. WITH ELEVATED
CAPE REMAINING SOUTH OF THE AREA...PER NAM/GFS...NO TSRA ARE
EXPECTED. THE PCPN SHOULD DIMINISH OVER THE WEST BY LATE EVENING AND
OVER THE CENTRAL AND EAST AFTER MIDNIGHT.
SATURDAY...ANY LINGERING PCPN OVER THE ERN CWA SHOULD MOVE OUT EARLY
AS THE AREA FALLS UNDER THE DRY SLOT. 850 MB TEMPS TO AROUND 10C
ALONG WITH SUNSHINE SHOULD PUSH TEMPS TO AROUND 70.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 453 AM EDT FRI APR 13 2012
SAT NGT...AS FAIRLY POTENT SHRTWV BEGINS TO LIFT NEWD OUT OF THE SW
CONUS...SFC LO PRES IS FCST TO DVLP IN THE CENTRAL PLAINS. THE 00Z
GFS/NAM HAVE TRENDED TOWARD A DEEPER LO PRES FARTHER TO THE N THAN
THE 12Z ECMWF AND 00Z CNDN/UKMET. PER NCEP GUIDANCE...WL FOLLOW THE
SCENARIO CLOSER TO THE 12Z ECMWF/21Z SREF. THIS GUIDANCE SHOWS A
WEAK HI PRES RDG IN THE WAKE OF DISTURBANCE RESPONSIBLE FOR THE SAT
POPS BRINGING A BRIEF PERIOD OF DRY WX SAT EVNG. HOWEVER...APRCH OF
ATTENDANT WARM FNT AND UPR DVGC IN RRQ OF 120KT H3 JET MAX IN SE
ONTARIO WL BRING A RETURN OF POPS FM THE SW AFT 06Z...ESPECIALLY
OVER THE S HALF OF THE CWA. WL RETAIN SCHC FOR TS OVER THE SCNTRL
PER ECWMF/SREF FCST SSI NOT FAR ABOVE ZERO/CLOSER PROXIMITY TO WARM
FNT. BUT EXPECT A FAIRLY SHARP GRADIENT OF POPS TO THE N AS THE
ECMWF SHOWS VERY DRY AIR AT H7 OVER NRN LK SUP AND N H925 WINDS ON
THE SRN FLANK OF BLDG HI PRES IN SCNTRL CAN PUSHING DRIER AIR ACRS
THE LK.
SUN...ALTHOUGH THERE ARE SOME TIMING DIFFERENCES...THE SREF/ECMWF
INDICATE SOME LO/MID LVL DRYING ON SUN AS RRQ DYNAMICS EXIT WELL TO
THE NE OF SHRTWV/SFC LO IN THE CENTRAL PLAINS. SO REDUCED POPS A BIT
ARND MID DAY BEFORE THE LO PRES TO THE SW BEGINS TO MOVE NE AND
INCRS PCPN CHCS ESPECIALLY NEAR THE WI BORDER LATER IN THE DAY.
TENDED TOWARD THE LO END OF GUIDANCE FOR TEMPS GIVEN THE LLVL NLY
FLOW OFF THE CHILLY WATERS OF LK SUP SHOWN BY THE ECMWF.
SUN NGT...SHRTWV/SFC LO LIFTING NEWD OUT OF THE PLAINS ARE FCST TO
APRCH THE UPR LKS...WITH 12HR H5 FALLS FCST UP TO 120M ASSOCIATED
WITH VIGOROUS DEEP LYR QVECTOR CNVGC. ALTHOUGH THE ECMWF/SREF
INDICATE SOME DRY SLOTTING MAY IMPACT AT LEAST THE SCNTRL LATE...
ELEVATED POPS TO LIKELY GIVEN IMPRESSIVE DYNAMICS. PCPN SHOULD BE IN
THE FORM OF RA IN THE EVNG...BUT AS LLVL COLDER AIR IS DRAWN INTO
THE WRN ZNS...EXPECT THE COMBINATION OF THIS LLVL CAD AND DYNAMIC
COOLING TO BRING A WINTRY MIX. 12Z ECMWF FCST SDNGS AND FCST H100-85
THKNS FIELDS SUG THERE COULD BE A NARROW BAND OF FZRA WHERE THE LLVL
COLD AIR INFUSION IS SHALLOW AND IN THE ABSENCE OF ANY DIURNAL
HEATING LATE AT NGT. DEPENDING ON HOW QUICKLY DEEPER COLD AIR CAN
MOVE INTO THE W HALF...AT LEAST SEVERAL INCHES OF SNOW ARE PSBL IN
THAT AREA...ESPECIALLY WHERE THE LLVL CYC NNE FLOW WL UPSLOPE.
MON...AS THE SHRTWV BEGINS TO SHEAR TO THE NE ON THE NW FLANK OF UPR
RDG OVER THE SE CONUS AND INCOMING COLD AIR BEGINS TO CAUSE LARGER
SCALE QVECTOR DVGC...EXPECT PCPN SHIELD TO SLOWLY DECAY EVEN THOUGH
LINGERING CHILLY LLVL CYC NNE FLOW WL LINGER AND BRING ABOUT
CONTINUED PCPN CHCS ESPECIALLY OVER THE NW HALF. A FEW INCHES MORE
OF SN ARE PSBL OVER THE HIER TERRAIN OF THE NW HALF ON THE NW FLANK
OF THE H85 LO TRACK BEFORE THE PCPN DIMINISHES IN THE AFTN.
EXTENDED...A DRIER BUT CHILLY PATTERN WL DOMINATE TUE INTO EARLY WED
WITH HUDSON BAY HI PRES BLDG INTO ONTARIO. MORE PCPN IS PSBL ON WED
INTO THU AS ANOTHER PAIR OF DISTURBANCES ARE FCST TO IMPACT THE GREAT
LKS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 134 PM EDT FRI APR 13 2012
VFR CONDITIONS WILL CONTINUE THRU THE AFTN HRS AT KIWD/KCMX/KSAW AS
VERY DRY AIRMASS LINGERS OVER THE AREA. LOW PRES SYSTEM LIFTING THRU
MN INTO NRN ONTARIO TONIGHT AND SAT WILL BRING A FEW SHRA TO THE
AREA TONIGHT. PCPN SHOULD BE LIGHT AND NOT DROP VIS BLO VFR AS
SYSTEM WILL BE WEAKENING WITH TIME. HOWEVER...LOW-LEVEL MOISTURE IS
MOVING NE PER OBS/SATELLITE AND SHOULD RESULT IN CIGS DROPPING TO
MVFR TONIGHT. ON SAT...DRYING OF THE COLUMN UNDERNEATH UPPER JET
STREAK WILL RESULT IN IMPROVEMENT TO VFR IN THE MORNING HRS. WINDS
WILL BE GUSTY SAT...ESPECIALLY AT KCMX UNDER A MORE FAVORABLE WRLY
FLOW THERE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 453 AM EDT FRI APR 13 2012
SE WINDS WILL INCREASE TO 20-25 KT AS A TROUGH MOVES TOWARD THE UPPER
MS VALLEY. AS THE LOW MOVES TO THE NORTH OF THE AREA SATURDAY...20-25
KT WINDS WILL VEER TO THE SW.
EXPECT INCRSG NE WINDS TO AT LEAST APPROACH GALE FORCE ON SUN NIGHT
INTO MON ON THE NW FLANK OF LO PRES MOVING THRU THE GREAT LAKES AS
THE PRES GRADIENT SHARPENS BETWEEN THIS FEATURE AND HI PRES BUILDING
TOWARD NW ONTARIO. LIGHTER WINDS WILL ARRIVE ON MON NIGHT INTO TUE AS
HI PRES BUILDS OVER THE UPPER LKS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...KC
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
709 AM EDT FRI APR 13 2012
.SYNOPSIS...
ISSUED AT 453 AM EDT FRI APR 13 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH OVER
THE WRN CONUS AND A DOWNSTREAM RIDG FROM ERN TX INTO THE UPPER MS
VALLEY. A VIGOROUS SHORTWAVE TROUGH OVER WRN KS WAS LIFTING NE. AT
THE SFC...SE FLOW WAS INCREASING OVER MN AND WRN WI BTWN HIGH PRES
OVER LAKE HURON AND A TROUGH OVER THE PLAINS. IR LOOP SHOWED HIGH
CLOUDS EXPANDING INTO WRN UPPER MI ASSOCIATED WITH THE DEVELOPING
WAA PATTERN TO THE WEST.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 453 AM EDT FRI APR 13 2012
TODAY INTO TONIGHT...
HIGH AND MID CLOUDS WILL CONTINUE TO SPREAD INTO THE CWA. THE CLOUDS
SHOULD BE THIN ENOUGH TO ALLOW PLENTY OF SUNSHINE AND DECENT MIXING
ALONG WITH WAA TO PUSH TEMPS INTO UPPER 50S AND LOWER 60S. THIS
SHOULD ALSO KEEP DEWPOINTS IN THE LOWER 20S OVER MUCH OF THE
AREA...RESULTING IN RH VALUES IN THE 20 TO 25 PERCENT RANGE. THE DRY
AIR COMBINED WITH SOUTH WINDS OF 10 TO 20 MPH WILL LEAD TO ELEVATED
FIRE WX RISK. SO...WL CONTINUE TO HIGHLIGHT THE HAZARD WITH THE
WILDFIRE POTENTIAL STATEMENT.
MDLS SUGGEST THAT AS THE PLAINS SHRTWV LIFTS INTO THE UPPER MS
VALLEY AND WRN LAKE SUPERIOR...MODERATE 700-500 MB QVECTOR CONV...
WAA/ISENTROPIC LIFT ALONG WITH FAVORABLE MOISTURE TRANSPORT WILL
PRODUCE SCT/NMRS SHRA. MODELS CONTINUED WITH THE TREND TOWARD A
LATER ARRIVAL OF PCPN INTO THE WEST BUT THEN MOVE THE BAND QUICKLY THROUGH
THE WEST IN THE EVENING. EXPECT THE GREATEST PCPN COVERAGE/POPS OVER
THE NW HALF OF THE CWA...CLOSER TO THE PATH OF THE SHRTWV AND UPPER
LEVEL DIV WITH THE LEFT EXIT REGION OF THE 250-300 MB JET. SINCE THE
DYNAMICS MOVE INTO THE DRY AIRMASS FAIRLY QUICKLY ...ONLY LIGHT PCPN
AMOUNTS OF A TENTH OF AN INCH OR LESS ARE EXPECTED. WITH ELEVATED
CAPE REMAINING SOUTH OF THE AREA...PER NAM/GFS...NO TSRA ARE
EXPECTED. THE PCPN SHOULD DIMINISH OVER THE WEST BY LATE EVENING AND
OVER THE CENTRAL AND EAST AFTER MIDNIGHT.
SATURDAY...ANY LINGERING PCPN OVER THE ERN CWA SHOULD MOVE OUT EARLY
AS THE AREA FALLS UNDER THE DRY SLOT. 850 MB TEMPS TO AROUND 10C
ALONG WITH SUNSHINE SHOULD PUSH TEMPS TO AROUND 70.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 453 AM EDT FRI APR 13 2012
SAT NGT...AS FAIRLY POTENT SHRTWV BEGINS TO LIFT NEWD OUT OF THE SW
CONUS...SFC LO PRES IS FCST TO DVLP IN THE CENTRAL PLAINS. THE 00Z
GFS/NAM HAVE TRENDED TOWARD A DEEPER LO PRES FARTHER TO THE N THAN
THE 12Z ECMWF AND 00Z CNDN/UKMET. PER NCEP GUIDANCE...WL FOLLOW THE
SCENARIO CLOSER TO THE 12Z ECMWF/21Z SREF. THIS GUIDANCE SHOWS A
WEAK HI PRES RDG IN THE WAKE OF DISTURBANCE RESPONSIBLE FOR THE SAT
POPS BRINGING A BRIEF PERIOD OF DRY WX SAT EVNG. HOWEVER...APRCH OF
ATTENDANT WARM FNT AND UPR DVGC IN RRQ OF 120KT H3 JET MAX IN SE
ONTARIO WL BRING A RETURN OF POPS FM THE SW AFT 06Z...ESPECIALLY
OVER THE S HALF OF THE CWA. WL RETAIN SCHC FOR TS OVER THE SCNTRL
PER ECWMF/SREF FCST SSI NOT FAR ABOVE ZERO/CLOSER PROXIMITY TO WARM
FNT. BUT EXPECT A FAIRLY SHARP GRADIENT OF POPS TO THE N AS THE
ECMWF SHOWS VERY DRY AIR AT H7 OVER NRN LK SUP AND N H925 WINDS ON
THE SRN FLANK OF BLDG HI PRES IN SCNTRL CAN PUSHING DRIER AIR ACRS
THE LK.
SUN...ALTHOUGH THERE ARE SOME TIMING DIFFERENCES...THE SREF/ECMWF
INDICATE SOME LO/MID LVL DRYING ON SUN AS RRQ DYNAMICS EXIT WELL TO
THE NE OF SHRTWV/SFC LO IN THE CENTRAL PLAINS. SO REDUCED POPS A BIT
ARND MID DAY BEFORE THE LO PRES TO THE SW BEGINS TO MOVE NE AND
INCRS PCPN CHCS ESPECIALLY NEAR THE WI BORDER LATER IN THE DAY.
TENDED TOWARD THE LO END OF GUIDANCE FOR TEMPS GIVEN THE LLVL NLY
FLOW OFF THE CHILLY WATERS OF LK SUP SHOWN BY THE ECMWF.
SUN NGT...SHRTWV/SFC LO LIFTING NEWD OUT OF THE PLAINS ARE FCST TO
APRCH THE UPR LKS...WITH 12HR H5 FALLS FCST UP TO 120M ASSOCIATED
WITH VIGOROUS DEEP LYR QVECTOR CNVGC. ALTHOUGH THE ECMWF/SREF
INDICATE SOME DRY SLOTTING MAY IMPACT AT LEAST THE SCNTRL LATE...
ELEVATED POPS TO LIKELY GIVEN IMPRESSIVE DYNAMICS. PCPN SHOULD BE IN
THE FORM OF RA IN THE EVNG...BUT AS LLVL COLDER AIR IS DRAWN INTO
THE WRN ZNS...EXPECT THE COMBINATION OF THIS LLVL CAD AND DYNAMIC
COOLING TO BRING A WINTRY MIX. 12Z ECMWF FCST SDNGS AND FCST H100-85
THKNS FIELDS SUG THERE COULD BE A NARROW BAND OF FZRA WHERE THE LLVL
COLD AIR INFUSION IS SHALLOW AND IN THE ABSENCE OF ANY DIURNAL
HEATING LATE AT NGT. DEPENDING ON HOW QUICKLY DEEPER COLD AIR CAN
MOVE INTO THE W HALF...AT LEAST SEVERAL INCHES OF SNOW ARE PSBL IN
THAT AREA...ESPECIALLY WHERE THE LLVL CYC NNE FLOW WL UPSLOPE.
MON...AS THE SHRTWV BEGINS TO SHEAR TO THE NE ON THE NW FLANK OF UPR
RDG OVER THE SE CONUS AND INCOMING COLD AIR BEGINS TO CAUSE LARGER
SCALE QVECTOR DVGC...EXPECT PCPN SHIELD TO SLOWLY DECAY EVEN THOUGH
LINGERING CHILLY LLVL CYC NNE FLOW WL LINGER AND BRING ABOUT
CONTINUED PCPN CHCS ESPECIALLY OVER THE NW HALF. A FEW INCHES MORE
OF SN ARE PSBL OVER THE HIER TERRAIN OF THE NW HALF ON THE NW FLANK
OF THE H85 LO TRACK BEFORE THE PCPN DIMINISHES IN THE AFTN.
EXTENDED...A DRIER BUT CHILLY PATTERN WL DOMINATE TUE INTO EARLY WED
WITH HUDSON BAY HI PRES BLDG INTO ONTARIO. MORE PCPN IS PSBL ON WED
INTO THU AS ANOTHER PAIR OF DISTURBANCES ARE FCST TO IMPACT THE GREAT
LKS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 708 AM EDT FRI APR 13 2012
VFR CONDITIONS WILL PREVAIL THROUGH TODAY. CLOUDS WILL INCREASE
SLOWLY AS A LOW PRESSURE SYSTEM MAKES ITS WAY TOWARDS THE GREAT
LAKES. THERE IS A CHANCE SHOWERS AT KIWD AROUND 00Z SATURDAY AND
THEN AT KCMX AND KSAW AFT 02Z. CIGS MAY LOWER TO MVFR AS LOW LEVEL
MOISTURE INCREASE BEHIND THE BAND OF SCATTERED SHOWERS MOVING
THROUGH THE AREA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 453 AM EDT FRI APR 13 2012
SE WINDS WILL INCREASE TO 20-25 KT AS A TROUGH MOVES TOWARD THE UPPER
MS VALLEY. AS THE LOW MOVES TO THE NORTH OF THE AREA SATURDAY...20-25
KT WINDS WILL VEER TO THE SW.
EXPECT INCRSG NE WINDS TO AT LEAST APPROACH GALE FORCE ON SUN NIGHT
INTO MON ON THE NW FLANK OF LO PRES MOVING THRU THE GREAT LAKES AS
THE PRES GRADIENT SHARPENS BETWEEN THIS FEATURE AND HI PRES BUILDING
TOWARD NW ONTARIO. LIGHTER WINDS WILL ARRIVE ON MON NIGHT INTO TUE AS
HI PRES BUILDS OVER THE UPPER LKS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
459 AM EDT FRI APR 13 2012
.SYNOPSIS...
ISSUED AT 453 AM EDT FRI APR 13 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH OVER
THE WRN CONUS AND A DOWNSTREAM RIDG FROM ERN TX INTO THE UPPER MS
VALLEY. A VIGOROUS SHORTWAVE TROUGH OVER WRN KS WAS LIFTING NE. AT
THE SFC...SE FLOW WAS INCREASING OVER MN AND WRN WI BTWN HIGH PRES
OVER LAKE HURON AND A TROUGH OVER THE PLAINS. IR LOOP SHOWED HIGH
CLOUDS EXPANDING INTO WRN UPPER MI ASSOCIATED WITH THE DEVELOPING
WAA PATTERN TO THE WEST.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 453 AM EDT FRI APR 13 2012
TODAY INTO TONIGHT...
HIGH AND MID CLOUDS WILL CONTINUE TO SPREAD INTO THE CWA. THE CLOUDS
SHOULD BE THIN ENOUGH TO ALLOW PLENTY OF SUNSHINE AND DECENT MIXING
ALONG WITH WAA TO PUSH TEMPS INTO UPPER 50S AND LOWER 60S. THIS
SHOULD ALSO KEEP DEWPOINTS IN THE LOWER 20S OVER MUCH OF THE
AREA...RESULTING IN RH VALUES IN THE 20 TO 25 PERCENT RANGE. THE DRY
AIR COMBINED WITH SOUTH WINDS OF 10 TO 20 MPH WILL LEAD TO ELEVATED
FIRE WX RISK. SO...WL CONTINUE TO HIGHLIGHT THE HAZARD WITH THE
WILDFIRE POTENTIAL STATEMENT.
MDLS SUGGEST THAT AS THE PLAINS SHRTWV LIFTS INTO THE UPPER MS
VALLEY AND WRN LAKE SUPERIOR...MODERATE 700-500 MB QVECTOR CONV...
WAA/ISENTROPIC LIFT ALONG WITH FAVORABLE MOISTURE TRANSPORT WILL
PRODUCE SCT/NMRS SHRA. MODELS CONTINUED WITH THE TREND TOWARD A
LATER ARRIVAL OF PCPN INTO THE WEST BUT THEN MOVE THE BAND QUICKLY THROUGH
THE WEST IN THE EVENING. EXPECT THE GREATEST PCPN COVERAGE/POPS OVER
THE NW HALF OF THE CWA...CLOSER TO THE PATH OF THE SHRTWV AND UPPER
LEVEL DIV WITH THE LEFT EXIT REGION OF THE 250-300 MB JET. SINCE THE
DYNAMICS MOVE INTO THE DRY AIRMASS FAIRLY QUICKLY ...ONLY LIGHT PCPN
AMOUNTS OF A TENTH OF AN INCH OR LESS ARE EXPECTED. WITH ELEVATED
CAPE REMAINING SOUTH OF THE AREA...PER NAM/GFS...NO TSRA ARE
EXPECTED. THE PCPN SHOULD DIMINISH OVER THE WEST BY LATE EVENING AND
OVER THE CENTRAL AND EAST AFTER MIDNIGHT.
SATURDAY...ANY LINGERING PCPN OVER THE ERN CWA SHOULD MOVE OUT EARLY
AS THE AREA FALLS UNDER THE DRY SLOT. 850 MB TEMPS TO AROUND 10C
ALONG WITH SUNSHINE SHOULD PUSH TEMPS TO AROUND 70.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 453 AM EDT FRI APR 13 2012
SAT NGT...AS FAIRLY POTENT SHRTWV BEGINS TO LIFT NEWD OUT OF THE SW
CONUS...SFC LO PRES IS FCST TO DVLP IN THE CENTRAL PLAINS. THE 00Z
GFS/NAM HAVE TRENDED TOWARD A DEEPER LO PRES FARTHER TO THE N THAN
THE 12Z ECMWF AND 00Z CNDN/UKMET. PER NCEP GUIDANCE...WL FOLLOW THE
SCENARIO CLOSER TO THE 12Z ECMWF/21Z SREF. THIS GUIDANCE SHOWS A
WEAK HI PRES RDG IN THE WAKE OF DISTURBANCE RESPONSIBLE FOR THE SAT
POPS BRINGING A BRIEF PERIOD OF DRY WX SAT EVNG. HOWEVER...APRCH OF
ATTENDANT WARM FNT AND UPR DVGC IN RRQ OF 120KT H3 JET MAX IN SE
ONTARIO WL BRING A RETURN OF POPS FM THE SW AFT 06Z...ESPECIALLY
OVER THE S HALF OF THE CWA. WL RETAIN SCHC FOR TS OVER THE SCNTRL
PER ECWMF/SREF FCST SSI NOT FAR ABOVE ZERO/CLOSER PROXIMITY TO WARM
FNT. BUT EXPECT A FAIRLY SHARP GRADIENT OF POPS TO THE N AS THE
ECMWF SHOWS VERY DRY AIR AT H7 OVER NRN LK SUP AND N H925 WINDS ON
THE SRN FLANK OF BLDG HI PRES IN SCNTRL CAN PUSHING DRIER AIR ACRS
THE LK.
SUN...ALTHOUGH THERE ARE SOME TIMING DIFFERENCES...THE SREF/ECMWF
INDICATE SOME LO/MID LVL DRYING ON SUN AS RRQ DYNAMICS EXIT WELL TO
THE NE OF SHRTWV/SFC LO IN THE CENTRAL PLAINS. SO REDUCED POPS A BIT
ARND MID DAY BEFORE THE LO PRES TO THE SW BEGINS TO MOVE NE AND
INCRS PCPN CHCS ESPECIALLY NEAR THE WI BORDER LATER IN THE DAY.
TENDED TOWARD THE LO END OF GUIDANCE FOR TEMPS GIVEN THE LLVL NLY
FLOW OFF THE CHILLY WATERS OF LK SUP SHOWN BY THE ECMWF.
SUN NGT...SHRTWV/SFC LO LIFTING NEWD OUT OF THE PLAINS ARE FCST TO
APRCH THE UPR LKS...WITH 12HR H5 FALLS FCST UP TO 120M ASSOCIATED
WITH VIGOROUS DEEP LYR QVECTOR CNVGC. ALTHOUGH THE ECMWF/SREF
INDICATE SOME DRY SLOTTING MAY IMPACT AT LEAST THE SCNTRL LATE...
ELEVATED POPS TO LIKELY GIVEN IMPRESSIVE DYNAMICS. PCPN SHOULD BE IN
THE FORM OF RA IN THE EVNG...BUT AS LLVL COLDER AIR IS DRAWN INTO
THE WRN ZNS...EXPECT THE COMBINATION OF THIS LLVL CAD AND DYNAMIC
COOLING TO BRING A WINTRY MIX. 12Z ECMWF FCST SDNGS AND FCST H100-85
THKNS FIELDS SUG THERE COULD BE A NARROW BAND OF FZRA WHERE THE LLVL
COLD AIR INFUSION IS SHALLOW AND IN THE ABSENCE OF ANY DIURNAL
HEATING LATE AT NGT. DEPENDING ON HOW QUICKLY DEEPER COLD AIR CAN
MOVE INTO THE W HALF...AT LEAST SEVERAL INCHES OF SNOW ARE PSBL IN
THAT AREA...ESPECIALLY WHERE THE LLVL CYC NNE FLOW WL UPSLOPE.
MON...AS THE SHRTWV BEGINS TO SHEAR TO THE NE ON THE NW FLANK OF UPR
RDG OVER THE SE CONUS AND INCOMING COLD AIR BEGINS TO CAUSE LARGER
SCALE QVECTOR DVGC...EXPECT PCPN SHIELD TO SLOWLY DECAY EVEN THOUGH
LINGERING CHILLY LLVL CYC NNE FLOW WL LINGER AND BRING ABOUT
CONTINUED PCPN CHCS ESPECIALLY OVER THE NW HALF. A FEW INCHES MORE
OF SN ARE PSBL OVER THE HIER TERRAIN OF THE NW HALF ON THE NW FLANK
OF THE H85 LO TRACK BEFORE THE PCPN DIMINISHES IN THE AFTN.
EXTENDED...A DRIER BUT CHILLY PATTERN WL DOMINATE TUE INTO EARLY WED
WITH HUDSON BAY HI PRES BLDG INTO ONTARIO. MORE PCPN IS PSBL ON WED
INTO THU AS ANOTHER PAIR OF DISTURBANCES ARE FCST TO IMPACT THE GREAT
LKS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 133 AM EDT FRI APR 13 2012
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD TONIGHT AND
FRIDAY AFTERNOON. CLOUDS WILL INCREASE SLOWLY AS A LOW PRESSURE
SYSTEM MAKES ITS WAY TOWARDS THE GREAT LAKES. THERE IS A CHANCE
SHOWERS AT KIWD AROUND 00Z SATURDAY AND THEN AT KCMX AND KSAW AFT
02Z. CIGS MAY LOWER TO MVFR AT KIWD AS SHOWERS MOVE ACROSS THE
AREA...BUT OTHERWISE CONFIDENCE IS NOT HIGH ENOUGH TO PUT
PREVAILING SHOWERS AT KCMX OR KSAW AS BEST FORCING WILL LIKELY STAY
TO THE WEST. FOR KCMX AND KSAW MENTIONED VCSH WITH A LOW VFR CIG
AROUND 5KFT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 453 AM EDT FRI APR 13 2012
SE WINDS WILL INCREASE TO 20-25 KT AS A TROUGH MOVES TOWARD THE UPPER
MS VALLEY. AS THE LOW MOVES TO THE NORTH OF THE AREA SATURDAY...20-25
KT WINDS WILL VEER TO THE SW.
EXPECT INCRSG NE WINDS TO AT LEAST APPROACH GALE FORCE ON SUN NIGHT
INTO MON ON THE NW FLANK OF LO PRES MOVING THRU THE GREAT LAKES AS
THE PRES GRADIENT SHARPENS BETWEEN THIS FEATURE AND HI PRES BUILDING
TOWARD NW ONTARIO. LIGHTER WINDS WILL ARRIVE ON MON NIGHT INTO TUE AS
HI PRES BUILDS OVER THE UPPER LKS. &&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...KC
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
423 PM CDT FRI APR 13 2012
.DISCUSSION...
Short Range (Tonight through Sunday)...
Surface trough extends from western IA through nw MO and through nw
OK. Boundary appears to have stalled and is delineated by cumulus
congestus on the northern portion and developing strong/possible
severe convection from southeastern KS swwd. This latter activity is
best handled by LSX local WRF while the 18z HRRR and 12z 4km NMM-WRF
models are a bit slower in their evolution. Airmass is moderately
unstable with MUCAPE in the 2000-2500 J/kg range with 40kt 0-6km
shear and 200 m2/s2 storm relative helicity, in essence enough to
support supercells. As the low level jet kicks in this evening
expect the growing area of convection to expand east-northeastward
along a pseudo warm front that the LSX local WRF extends across the
far southern counties. This boundary and the convection will be
supported by the increasing southerly low level jet and allow the
complex to spread north toward the MO River by Saturday morning.
Have used this idea to construct grids/zones for tonight. There will
be some severe potential for the far southern counties overnight
with large hail the primary severe threat. Heavy rains are possible
over the far southern counties but 3hr flash flood guidance
averaging 2.5 inches/3 hours suggests rainfall tonight not enough to
warrant a watch.
Activity will likely be ongoing across area south of the MO River.
The warm front and convection will continue northward during the day
and have scaled back afternoon pops south of the MO River.
Temperatures will be tricky due to the rain cooled airmass and cloud
cover. Should the sun fail to come out the current temperatures,
although cooler than the previous forecast, may prove to be still
too warm.
Severe risk during the daylight hours will be tied to the morning
convection and believe it will be quite low as the airmass will
likely be quite saturated and minimal instability. Main focus for
the severe risk will be Saturday late evening into Sunday morning.
Upstream severe weather outbreak will likely advance steadily
eastward as a squall line as individual cells race northeast off the
line in excess of 50kts. Despite weakening instability during the
evening hours the low level shear will be quite high and thus still
able to support rotating individual storms through the night. As a
result there will be a risk of severe weather mainly west of
Interstate 35 for Saturday night. All storm modes...large hail,
damaging winds and isolated tornadoes...will be possible.
Sunday`s severe threat will likely be held hostage by how Saturday
night`s convective event unfolds and lays out any boundaries. Will
use a model consensus approach which suggests best convective
chances will be over the eastern half of the CWA. Rain chances will
end from west to east during the day on Sunday with Sunday night
likely dry.
MJ
Medium Range (Monday through Friday)...
By Monday the upper level trough that made for a stormy weekend will
shift east of the area and flatten out as the upper level flow
across the CONUS becomes more zonal. The main weather concerns will
revolve around two chances for precipitation, the first on Wednesday
and again Friday. High pressure will move into the area on Monday
behind a departing cold front. Temperatures will range into the
upper 50s to lower 60s. The surface ridge will remain over the area
on Tuesday as abundant sunshine will help temperatures range into
the low to mid 60s. On Wednesday a weak upper level shortwave
embedded in the zonal flow will move through the Upper Midwest
forcing a weak cold front through the area. Some light showers will
be possible with this system on Wednesday with the best chance for
showers along the Missouri/Iowa border. Thursday will feature a
return to southerly flow out ahead of another cold front moving
through the Plains. This will allow high temperatures to reach into
the 70s across the forecast area. Friday, a another upper level
shortwave will drop southeastward from the Northern Plains into the
Midwest which will force the aforementioned cold front though the
area. Showers and thunderstorms will be possible on Friday as the
front moves through thus have chance pops in for the day Friday.
73
&&
.AVIATION...
For the 18Z TAFs...Afternoon cigs expected to improve from MVFR to
VFR and eventually scatter out by early evening as surface winds
veer to the south and increase in speed. Will need to watch a weak
surface trough stalling out over nw MO this evening as some short
range models suggest a short line of convection could pop up this
evening and then dissipate.
Think MVFR fog will form during the pre-dawn hours at all 3
terminals due to increasing low level moisture and minimal cloud
cover. MVFR cigs will also return and there is the potential for IFR
cigs to form instead as the fog layer congeals. Convection likely to
form from OK through southern MO this evening and lift/spread
northward and could reach the KC Metro before sunrise.
MJ
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1204 PM CDT FRI APR 13 2012
.UPDATE...
ISSUED AT 1155 AM CDT FRI APR 13 2012
AREA OF RAIN AND EMBEDDED THUNDERSTORMS CONTINUES TO SLOWLY MOVE
EAST ACROSS THE FORECAST AREA LATE THIS MORNING. LOW LEVEL JET
CONTINUES TO WEAKEN AND VEER...ALLOWING A SLOW DIMINISHING TREND
AND SHIFT TO THE PRECIP TO THE SOUTHEAST. EXPECT BACK EDGE OF
STEADY RAIN TO CLEAR DOWNTOWN AROUND 3:30 PM. TEMPERATURES HAVE
FALLEN INTO THE UPPER 40S AND LOWER 50S WITH THE RAIN. EXPECT SOME
REBOUND IN CENTRAL MISSOURI LATE THIS AFTERNOON...WITH STEADY
TEMPS ELSEWHERE.
CVKING
&&
.SHORT TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TODAY)
DIFFICULT PRECIPITATION FORECAST FOR TODAY...WHICH ALSO MAKES FOR A
DIFFICULT TEMPERATURE FORECAST. CURRENT RADAR HAS SCATTERED TO
NUMEROUS THUNDERSTORMS BREAKING OUT ALONG A LINE FROM JOPLIN TO
SEDALIA. THE STORMS ARE BEING FED BY A BROAD LOW LEVEL JET WITH
8-10C DEWPOINTS EMBEDDED IN IT. BROAD BUT SUBSTANTIAL MOISTURE
CONVERGENCE IS OCCURRING WHERE THE LOW LEVEL JET IS IMPACTING THE
WESTERN EDGE OF THE RIDGE OVER THE OHIO VALLEY. THE RUC HAS BEEN
CONSISTENTLY PUSHING THE AREA OF MOISTURE CONVERGENCE EAST THROUGH
THE MORNING. MESOSCALE MODELS INCLUDING THE NSSL 4KM WRF...THE NCEP
4KM WRF...OUR OWN LOCALLY RUN WRF...THE HRRR...AND THE EXPERIMENTAL
NARRE ALL SHOW THIS CONVECTION CONTINUING AS THE MOISTURE
CONVERGENCE SPREADS EAST. THE REAL QUESTION IS WHAT THE SOUTHERN
EXTENT WILL END UP BEING. THE HRRR AND THE VARIOUS HI RES WRFS
SPREAD RAIN OVER MOST OF THE CWFA WHILE OPERATIONAL MODELS SUCH AS
THE GFS AND NAM KEEP PRECIP CONFINED TO THE NORTHERN 2/3 OF THE
AREA. WITH PRECIP WELL INTO SOUTHERN MISSOURI AT THIS TIME...HAVE
DECIDED TO FOLLOW THE MORE WIDESPREAD SOLUTIONS OF THE MESOSCALE
MODELS AT THIS TIME. TEMPERATURES WILL DEPEND GREATLY ON CONVECTION
TODAY. STUCK PRETTY CLOSE TO A BLEND OF NAM/GFS MOS GUIDANCE.
CARNEY
&&
.LONG TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TONIGHT THROUGH THURSDAY)
IT APPEARS THERE WILL BE A LULL IN THE PRECIPITATION THIS EVENING
BEFORE THE NEXT ROUND OF SHOWERS AND THUNDERSTORMS GETS GOING LATE
THIS EVENING...AND MORE LIKELY OVERNIGHT. GUIDANCE IS IN GOOD
AGREEMENT SHOWING AN IMPULSE IN THE SW FLOW ALOFT TRACKING INTO
CENTRAL MO BETWEEN 06-12Z INTERACTING WITH A 30-40 KT SWLY LLJ
POSITIONED THRU THE CWA. THE MAIN QUESTION IS THE LOCATION WHERE
THE THUNDERSTORMS WILL ALIGN/FOCUS...WITH A RANGE OF SOLUTIONS
FROM ACROSS FAR NORTHERN MO TO JUST NORTH OF I-44. THE GREATEST
CONSENSUS IS THIS AXIS WILL BECOME ESTABLISHED FROM AROUND
COLUMBIA THROUGH BOWLING GREEN. SHOWERS AND THUNDERSTORMS WILL
GRADUALLY SHIFT TO THE EAST ON SATURDAY MORNING AND BELIEVE WILL
MOST OF THE ACTIVITY WILL HAVE EXITED THE CWA BY 18Z AS THE
IMPULSE MIGRATES TO THE NORTHEAST INTO CENTRAL IL. AFTERNOON
TEMPERATURES SHOULD RECOVER NICELY IN THE WAKE OF THE MORNING
CONVECTION AS CLOUDS DECREASE...WARMING INTO THE 70S.
THERE ISNT MUCH TO LATCH ONTO FOR POPS ON SATURDAY NIGHT. THE MOST
UNSTABLE AIR WILL RESIDE ACROSS THE NORTHERN PORTION OF THE CWA
WHILE A 50+ KT LLJ WILL REMAIN POSITIONED ACROSS THE AREA. ITS HARD
TO SAY IF THERE WILL BE A RESIDUAL OUTFLOW BOUNDARY FROM THE
CONVECTION EARLIER IN THE DAY. AND...THE MODELS FAIL TO DEPICT ANY
DISCERNABLE SURFACE BOUNDARIES OR DISTURBANCES ALOFT WHICH WOULD
HELP FOCUS CONVECTION. THUS WHILE I CAN`T RULE OUT
PRECIPITATION...ANY SHOWERS AND THUNDERSTORMS WOULD APPEAR TO HAVE
LIMITED ORGANIZATION AND BE MORE SPOTTY IN COVERAGE WITH THE
GREATEST PROBABILITY ACROSS NE MO INTO WEST CENTRAL IL IN PROXIMITY
TO THE GREATEST INSTABILITY.
IT APPEARS THE MAIN THRUST OF SHOWERS AND THUNDERSTORMS WILL BE ON
SUNDAY AFTERNOON AND EVENING AS THE MAIN UPPER TROF PROGRESSES INTO
THE MID MS VALLEY. DEEP LAYER SHEAR OF 60+ KTS WITHIN THE WARM
SECTOR AND MUCAPES OF 750-1500 J/KG SUGGEST A THREAT OF ORGANIZED
SEVERE STORMS WITH A MIXED MODE IN THE AFTERNOON TRANSITIONING TO
MORE LINEAR DURING THE EVENING. BELIEVE MOST OF THE PRECIPITATION
WILL HAVE EXITED TO THE EAST OF THE CWA ON MONDAY MORNING...WITH
DRIER AND COOLER AIR SPREADING ACROSS THE AREA IN THE WAKE OF THE
COLD FRONTAL PASSAGE.
GLASS
&&
.AVIATION...
ISSUED AT 1155 AM CDT FRI APR 13 2012
AREA OF RAIN WITH EMBEDDED THUNDERSTORMS WILL MOVE EAST ACROSS THE
AREA THIS AFTERNOON...CLEARING FROM WEST-NORTHWEST TO EAST-
SOUTHEAST. EXPECT KUIN AND KCOU SHOULD BE DONE WITH RAIN BY
18Z...AND ST. LOUIS METRO TAFS BETWEEN 20Z KSUS AND 21Z KCPS.
THUNDER WILL CONTINUE TO REFOCUS FURTHER SOUTH AS THE LOW LEVEL
JET VEERS...SO MAY JUST HAVE A VCTS TO COVER LIGHTNING GIVEN ISOLATED
NATURE IN ST. LOUIS. WIND TO REMAIN SOUTHEAST AT 10 TO 15 KTS.
QUIET WEATHER EXPECTED THIS EVENING BEFORE ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS DEVELOPS ACROSS EASTERN KANSAS AND
WESTERN MISSOURI AND MARCHES EAST ACROSS THE FORECAST AREA LATE
TONIGHT AND SATURDAY MORNING.
SPECIFICS FOR KSTL...
RAIN CONTINUES THROUGH 20Z WITH MOST OF THE THUNDER REMAINING
SOUTH OF THE TERMINAL. WIND TO REMAIN SOUTHEAST. QUIET WEATHER
EXPECTED TONIGHT...BEFORE ANOTHER ROUND OF SHOWERS AND STORMS
IMPACTS THE TERMINAL AFTER 06Z.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1015 AM CDT FRI APR 13 2012
.UPDATE...
ISSUED AT 1015 AM CDT FRI APR 13 2012
SLUG OF RAIN AND IMBEDDED TSRA IS MOVING THRU THE FA ATTM N OF A
WRMFNT...AND IS MOVING RATHER SLOWLY AND IS BACKBUILDING A BIT. THIS
AREA OF RAIN IS CARRYING WITH IT A SIZABLE AREA OF RAIN-COOLED AIR
WITH TEMPS IN THE UPR 40S. LOOK FOR THE RAIN TO BEGIN TO EXIT
CNTRL MO BTWN 11A-12P...WHILE NOT GETTING OUT OF AREAS NEAR THE MS
RIVER UNTIL BETWEEN 2 AND 4 PM. MORE SPECIFICALLY...STL CITY
SHOULD BE UNDER THE THREAT OF STEADY RAIN UNTIL AROUND 3 PM.
TEMPS WILL BE A CHALLENGE AND ALREADY TOOK THE AXE TO SEVERAL
AREAS WITH THICK CLOUD COVER EXPECTED THRU MOST OF THE DAY AND A
WRMFNT THAT WILL BE KEPT AT BAY. WILL STRUGGLE TO EXIT THE 50S FOR
MOST LOCATIONS...ALTHOUGH CNTRL MO WITH THE RAIN EXITING SOONER
AND SOME SUN EXPECTED AND PROXIMITY OF WRMFNT SHOULD ALLOW THEM TO
RECOVER INTO THE 60S.
TEMPS SHOULD BE NEAR STEADY IF NOT RISE SLOWLY OVERNIGHT AS
WRMFNT FINALLY MAKES ITS PUSH THRU THE FA.
TES
&&
.SHORT TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TODAY)
DIFFICULT PRECIPITATION FORECAST FOR TODAY...WHICH ALSO MAKES FOR A
DIFFICULT TEMPERATURE FORECAST. CURRENT RADAR HAS SCATTERED TO
NUMEROUS THUNDERSTORMS BREAKING OUT ALONG A LINE FROM JOPLIN TO
SEDALIA. THE STORMS ARE BEING FED BY A BROAD LOW LEVEL JET WITH
8-10C DEWPOINTS EMBEDDED IN IT. BROAD BUT SUBSTANTIAL MOISTURE
CONVERGENCE IS OCCURRING WHERE THE LOW LEVEL JET IS IMPACTING THE
WESTERN EDGE OF THE RIDGE OVER THE OHIO VALLEY. THE RUC HAS BEEN
CONSISTENTLY PUSHING THE AREA OF MOISTURE CONVERGENCE EAST THROUGH
THE MORNING. MESOSCALE MODELS INCLUDING THE NSSL 4KM WRF...THE NCEP
4KM WRF...OUR OWN LOCALLY RUN WRF...THE HRRR...AND THE EXPERIMENTAL
NARRE ALL SHOW THIS CONVECTION CONTINUING AS THE MOISTURE
CONVERGENCE SPREADS EAST. THE REAL QUESTION IS WHAT THE SOUTHERN
EXTENT WILL END UP BEING. THE HRRR AND THE VARIOUS HI RES WRFS
SPREAD RAIN OVER MOST OF THE CWFA WHILE OPERATIONAL MODELS SUCH AS
THE GFS AND NAM KEEP PRECIP CONFINED TO THE NORTHERN 2/3 OF THE
AREA. WITH PRECIP WELL INTO SOUTHERN MISSOURI AT THIS TIME...HAVE
DECIDED TO FOLLOW THE MORE WIDESPREAD SOLUTIONS OF THE MESOSCALE
MODELS AT THIS TIME. TEMPERATURES WILL DEPEND GREATLY ON CONVECTION
TODAY. STUCK PRETTY CLOSE TO A BLEND OF NAM/GFS MOS GUIDANCE.
CARNEY
&&
.LONG TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TONIGHT THROUGH THURSDAY)
IT APPEARS THERE WILL BE A LULL IN THE PRECIPITATION THIS EVENING
BEFORE THE NEXT ROUND OF SHOWERS AND THUNDERSTORMS GETS GOING LATE
THIS EVENING...AND MORE LIKELY OVERNIGHT. GUIDANCE IS IN GOOD
AGREEMENT SHOWING AN IMPULSE IN THE SW FLOW ALOFT TRACKING INTO
CENTRAL MO BETWEEN 06-12Z INTERACTING WITH A 30-40 KT SWLY LLJ
POSITIONED THRU THE CWA. THE MAIN QUESTION IS THE LOCATION WHERE
THE THUNDERSTORMS WILL ALIGN/FOCUS...WITH A RANGE OF SOLUTIONS
FROM ACROSS FAR NORTHERN MO TO JUST NORTH OF I-44. THE GREATEST
CONSENSUS IS THIS AXIS WILL BECOME ESTABLISHED FROM AROUND
COLUMBIA THROUGH BOWLING GREEN. SHOWERS AND THUNDERSTORMS WILL
GRADUALLY SHIFT TO THE EAST ON SATURDAY MORNING AND BELIEVE WILL
MOST OF THE ACTIVITY WILL HAVE EXITED THE CWA BY 18Z AS THE
IMPULSE MIGRATES TO THE NORTHEAST INTO CENTRAL IL. AFTERNOON
TEMPERATURES SHOULD RECOVER NICELY IN THE WAKE OF THE MORNING
CONVECTION AS CLOUDS DECREASE...WARMING INTO THE 70S.
THERE ISNT MUCH TO LATCH ONTO FOR POPS ON SATURDAY NIGHT. THE MOST
UNSTABLE AIR WILL RESIDE ACROSS THE NORTHERN PORTION OF THE CWA
WHILE A 50+ KT LLJ WILL REMAIN POSITIONED ACROSS THE AREA. ITS HARD
TO SAY IF THERE WILL BE A RESIDUAL OUTFLOW BOUNDARY FROM THE
CONVECTION EARLIER IN THE DAY. AND...THE MODELS FAIL TO DEPICT ANY
DISCERNABLE SURFACE BOUNDARIES OR DISTURBANCES ALOFT WHICH WOULD
HELP FOCUS CONVECTION. THUS WHILE I CAN`T RULE OUT
PRECIPITATION...ANY SHOWERS AND THUNDERSTORMS WOULD APPEAR TO HAVE
LIMITED ORGANIZATION AND BE MORE SPOTTY IN COVERAGE WITH THE
GREATEST PROBABILITY ACROSS NE MO INTO WEST CENTRAL IL IN PROXIMITY
TO THE GREATEST INSTABILITY.
IT APPEARS THE MAIN THRUST OF SHOWERS AND THUNDERSTORMS WILL BE ON
SUNDAY AFTERNOON AND EVENING AS THE MAIN UPPER TROF PROGRESSES INTO
THE MID MS VALLEY. DEEP LAYER SHEAR OF 60+ KTS WITHIN THE WARM
SECTOR AND MUCAPES OF 750-1500 J/KG SUGGEST A THREAT OF ORGANIZED
SEVERE STORMS WITH A MIXED MODE IN THE AFTERNOON TRANSITIONING TO
MORE LINEAR DURING THE EVENING. BELIEVE MOST OF THE PRECIPITATION
WILL HAVE EXITED TO THE EAST OF THE CWA ON MONDAY MORNING...WITH
DRIER AND COOLER AIR SPREADING ACROSS THE AREA IN THE WAKE OF THE
COLD FRONTAL PASSAGE.
GLASS
&&
.AVIATION...
ISSUED AT 624 AM CDT FRI APR 13 2012
AREA OF SHOWERS AND THUNDERSTORMS OVER WESTERN AND CENTRAL MISSOURI
WILL OVERSPREAD EASTERN MISSOURI AND SOUTHWEST ILLINOIS. WHILE VFR
FLIGHT CONDITIONS WILL PREVAIL...THERE WILL BE AREAS OF MVFR AND
EVEN IFR IN THE HEAVIEST STORMS. STORMS SHOULD CLEAR THE BI-STATE
REGION BY MID AFTERNOON. THE NEXT ROUND OF THUNDERSTORMS IS
EXPECTED TO DEVELOP OVER CENTRAL MISSOURI DURING THE LATE EVENING
OR JUST AFTER MIDNIGHT AND AFFECT MUCH OF THE AREA ALONG AND NORTH
OF I-70. TIMING AND AREAL COVERAGE OF THESE STORMS IS STILL
UNCERTAIN AT THIS TIME.
SPECIFICS FOR KSTL...
SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE TERMINAL FROM THE
WEST THIS MORNING AND THERE WILL LIKELY BE PRECIPITATION IN THE
VICINITY AT LEAST THROUGH 18Z. THAT BEING SAID...THINK VFR FLIGHT
CONDITIONS WILL PREVAIL EXCEPT IF A STRONG THUNDERSTORM MOVES
DIRECTLY OVER THE TERMINAL. ONCE THE RAIN ENDS THERE SHOULD BE A
QUIET PERIOD UNTIL LATE TONIGHT. ANOTHER ROUND OF STORMS WILL
DEVELOP DURING THE PRE-DAWN HOURS ON SATURDAY. TIMING AND AREAL
COVERAGE OF THESE STORMS IS STILL UNCERTAIN...HOWEVER CURRENT
THINKING IS THE STRONGEST STORMS WILL STAY NORTH OF THE TERMINAL.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
640 AM CDT FRI APR 13 2012
.SHORT TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TODAY)
DIFFICULT PRECIPITATION FORECAST FOR TODAY...WHICH ALSO MAKES FOR A
DIFFICULT TEMPERATURE FORECAST. CURRENT RADAR HAS SCATTERED TO
NUMEROUS THUNDERSTORMS BREAKING OUT ALONG A LINE FROM JOPLIN TO
SEDALIA. THE STORMS ARE BEING FED BY A BROAD LOW LEVEL JET WITH
8-10C DEWPOINTS EMBEDDED IN IT. BROAD BUT SUBSTANTIAL MOISTURE
CONVERGENCE IS OCCURRING WHERE THE LOW LEVEL JET IS IMPACTING THE
WESTERN EDGE OF THE RIDGE OVER THE OHIO VALLEY. THE RUC HAS BEEN
CONSISTENTLY PUSHING THE AREA OF MOISTURE CONVERGENCE EAST THROUGH
THE MORNING. MESOSCALE MODELS INCLUDING THE NSSL 4KM WRF...THE NCEP
4KM WRF...OUR OWN LOCALLY RUN WRF...THE HRRR...AND THE EXPERIMENTAL
NARRE ALL SHOW THIS CONVECTION CONTINUING AS THE MOISTURE
CONVERGENCE SPREADS EAST. THE REAL QUESTION IS WHAT THE SOUTHERN
EXTENT WILL END UP BEING. THE HRRR AND THE VARIOUS HI RES WRFS
SPREAD RAIN OVER MOST OF THE CWFA WHILE OPERATIONAL MODELS SUCH AS
THE GFS AND NAM KEEP PRECIP CONFINED TO THE NORTHERN 2/3 OF THE
AREA. WITH PRECIP WELL INTO SOUTHERN MISSOURI AT THIS TIME...HAVE
DECIDED TO FOLLOW THE MORE WIDESPREAD SOLUTIONS OF THE MESOSCALE
MODELS AT THIS TIME. TEMPERATURES WILL DEPEND GREATLY ON CONVECTION
TODAY. STUCK PRETTY CLOSE TO A BLEND OF NAM/GFS MOS GUIDANCE.
CARNEY
&&
.LONG TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TONIGHT THROUGH THURSDAY)
IT APPEARS THERE WILL BE A LULL IN THE PRECIPITATION THIS EVENING
BEFORE THE NEXT ROUND OF SHOWERS AND THUNDERSTORMS GETS GOING LATE
THIS EVENING...AND MORE LIKELY OVERNIGHT. GUIDANCE IS IN GOOD
AGREEMENT SHOWING AN IMPULSE IN THE SW FLOW ALOFT TRACKING INTO
CENTRAL MO BETWEEN 06-12Z INTERACTING WITH A 30-40 KT SWLY LLJ
POSITIONED THRU THE CWA. THE MAIN QUESTION IS THE LOCATION WHERE
THE THUNDERSTORMS WILL ALIGN/FOCUS...WITH A RANGE OF SOLUTIONS
FROM ACROSS FAR NORTHERN MO TO JUST NORTH OF I-44. THE GREATEST
CONSENSUS IS THIS AXIS WILL BECOME ESTABLISHED FROM AROUND
COLUMBIA THROUGH BOWLING GREEN. SHOWERS AND THUNDERSTORMS WILL
GRADUALLY SHIFT TO THE EAST ON SATURDAY MORNING AND BELIEVE WILL
MOST OF THE ACTIVITY WILL HAVE EXITED THE CWA BY 18Z AS THE
IMPULSE MIGRATES TO THE NORTHEAST INTO CENTRAL IL. AFTERNOON
TEMPERATURES SHOULD RECOVER NICELY IN THE WAKE OF THE MORNING
CONVECTION AS CLOUDS DECREASE...WARMING INTO THE 70S.
THERE ISNT MUCH TO LATCH ONTO FOR POPS ON SATURDAY NIGHT. THE MOST
UNSTABLE AIR WILL RESIDE ACROSS THE NORTHERN PORTION OF THE CWA
WHILE A 50+ KT LLJ WILL REMAIN POSITIONED ACROSS THE AREA. ITS HARD
TO SAY IF THERE WILL BE A RESIDUAL OUTFLOW BOUNDARY FROM THE
CONVECTION EARLIER IN THE DAY. AND...THE MODELS FAIL TO DEPICT ANY
DISCERNABLE SURFACE BOUNDARIES OR DISTURBANCES ALOFT WHICH WOULD
HELP FOCUS CONVECTION. THUS WHILE I CAN`T RULE OUT
PRECIPITATION...ANY SHOWERS AND THUNDERSTORMS WOULD APPEAR TO HAVE
LIMITED ORGANIZATION AND BE MORE SPOTTY IN COVERAGE WITH THE
GREATEST PROBABILITY ACROSS NE MO INTO WEST CENTRAL IL IN PROXIMITY
TO THE GREATEST INSTABILITY.
IT APPEARS THE MAIN THRUST OF SHOWERS AND THUNDERSTORMS WILL BE ON
SUNDAY AFTERNOON AND EVENING AS THE MAIN UPPER TROF PROGRESSES INTO
THE MID MS VALLEY. DEEP LAYER SHEAR OF 60+ KTS WITHIN THE WARM
SECTOR AND MUCAPES OF 750-1500 J/KG SUGGEST A THREAT OF ORGANIZED
SEVERE STORMS WITH A MIXED MODE IN THE AFTERNOON TRANSITIONING TO
MORE LINEAR DURING THE EVENING. BELIEVE MOST OF THE PRECIPITATION
WILL HAVE EXITED TO THE EAST OF THE CWA ON MONDAY MORNING...WITH
DRIER AND COOLER AIR SPREADING ACROSS THE AREA IN THE WAKE OF THE
COLD FRONTAL PASSAGE.
GLASS
&&
.AVIATION...
ISSUED AT 624 AM CDT FRI APR 13 2012
AREA OF SHOWERS AND THUNDERSTORMS OVER WESTERN AND CENTRAL MISSOURI
WILL OVERSPREAD EASTERN MISSOURI AND SOUTHWEST ILLINOIS. WHILE VFR
FLIGHT CONDITIONS WILL PREVAIL...THERE WILL BE AREAS OF MVFR AND
EVEN IFR IN THE HEAVIEST STORMS. STORMS SHOULD CLEAR THE BI-STATE
REGION BY MID AFTERNOON. THE NEXT ROUND OF THUNDERSTORMS IS
EXPECTED TO DEVELOP OVER CENTRAL MISSOURI DURING THE LATE EVENING
OR JUST AFTER MIDNIGHT AND AFFECT MUCH OF THE AREA ALONG AND NORTH
OF I-70. TIMING AND AREAL COVERAGE OF THESE STORMS IS STILL
UNCERTAIN AT THIS TIME.
SPECIFICS FOR KSTL...
SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE TERMINAL FROM THE
WEST THIS MORNING AND THERE WILL LIKELY BE PRECIPITATION IN THE
VICINITY AT LEAST THROUGH 18Z. THAT BEING SAID...THINK VFR FLIGHT
CONDITIONS WILL PREVAIL EXCEPT IF A STRONG THUNDERSTORM MOVES
DIRECTLY OVER THE TERMINAL. ONCE THE RAIN ENDS THERE SHOULD BE A
QUIET PERIOD UNTIL LATE TONIGHT. ANOTHER ROUND OF STORMS WILL
DEVELOP DURING THE PRE-DAWN HOURS ON SATURDAY. TIMING AND AREAL
COVERAGE OF THESE STORMS IS STILL UNCERTAIN...HOWEVER CURRENT
THINKING IS THE STRONGEST STORMS WILL STAY NORTH OF THE TERMINAL.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
357 AM CDT FRI APR 13 2012
.SHORT TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TODAY)
DIFFICULT PRECIPITATION FORECAST FOR TODAY...WHICH ALSO MAKES FOR A
DIFFICULT TEMPERATURE FORECAST. CURRENT RADAR HAS SCATTERED TO
NUMEROUS THUNDERSTORMS BREAKING OUT ALONG A LINE FROM JOPLIN TO
SEDALIA. THE STORMS ARE BEING FED BY A BROAD LOW LEVEL JET WITH
8-10C DEWPOINTS EMBEDDED IN IT. BROAD BUT SUBSTANTIAL MOISTURE
CONVERGENCE IS OCCURRING WHERE THE LOW LEVEL JET IS IMPACTING THE
WESTERN EDGE OF THE RIDGE OVER THE OHIO VALLEY. THE RUC HAS BEEN
CONSISTENTLY PUSHING THE AREA OF MOISTURE CONVERGENCE EAST THROUGH
THE MORNING. MESOSCALE MODELS INCLUDING THE NSSL 4KM WRF...THE NCEP
4KM WRF...OUR OWN LOCALLY RUN WRF...THE HRRR...AND THE EXPERIMENTAL
NARRE ALL SHOW THIS CONVECTION CONTINUING AS THE MOISTURE
CONVERGENCE SPREADS EAST. THE REAL QUESTION IS WHAT THE SOUTHERN
EXTENT WILL END UP BEING. THE HRRR AND THE VARIOUS HI RES WRFS
SPREAD RAIN OVER MOST OF THE CWFA WHILE OPERATIONAL MODELS SUCH AS
THE GFS AND NAM KEEP PRECIP CONFINED TO THE NORTHERN 2/3 OF THE
AREA. WITH PRECIP WELL INTO SOUTHERN MISSOURI AT THIS TIME...HAVE
DECIDED TO FOLLOW THE MORE WIDESPREAD SOLUTIONS OF THE MESOSCALE
MODELS AT THIS TIME. TEMPERATURES WILL DEPEND GREATLY ON CONVECTION
TODAY. STUCK PRETTY CLOSE TO A BLEND OF NAM/GFS MOS GUIDANCE.
CARNEY
&&
.LONG TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TONIGHT THROUGH THURSDAY)
IT APPEARS THERE WILL BE A LULL IN THE PRECIPITATION THIS EVENING
BEFORE THE NEXT ROUND OF SHOWERS AND THUNDERSTORMS GETS GOING LATE
THIS EVENING...AND MORE LIKELY OVERNIGHT. GUIDANCE IS IN GOOD
AGREEMENT SHOWING AN IMPULSE IN THE SW FLOW ALOFT TRACKING INTO
CENTRAL MO BETWEEN 06-12Z INTERACTING WITH A 30-40 KT SWLY LLJ
POSITIONED THRU THE CWA. THE MAIN QUESTION IS THE LOCATION WHERE
THE THUNDERSTORMS WILL ALIGN/FOCUS...WITH A RANGE OF SOLUTIONS
FROM ACROSS FAR NORTHERN MO TO JUST NORTH OF I-44. THE GREATEST
CONSENSUS IS THIS AXIS WILL BECOME ESTABLISHED FROM AROUND
COLUMBIA THROUGH BOWLING GREEN. SHOWERS AND THUNDERSTORMS WILL
GRADUALLY SHIFT TO THE EAST ON SATURDAY MORNING AND BELIEVE WILL
MOST OF THE ACTIVITY WILL HAVE EXITED THE CWA BY 18Z AS THE
IMPULSE MIGRATES TO THE NORTHEAST INTO CENTRAL IL. AFTERNOON
TEMPERATURES SHOULD RECOVER NICELY IN THE WAKE OF THE MORNING
CONVECTION AS CLOUDS DECREASE...WARMING INTO THE 70S.
THERE ISNT MUCH TO LATCH ONTO FOR POPS ON SATURDAY NIGHT. THE MOST
UNSTABLE AIR WILL RESIDE ACROSS THE NORTHERN PORTION OF THE CWA
WHILE A 50+ KT LLJ WILL REMAIN POSITIONED ACROSS THE AREA. ITS HARD
TO SAY IF THERE WILL BE A RESIDUAL OUTFLOW BOUNDARY FROM THE
CONVECTION EARLIER IN THE DAY. AND...THE MODELS FAIL TO DEPICT ANY
DISCERNABLE SURFACE BOUNDARIES OR DISTURBANCES ALOFT WHICH WOULD
HELP FOCUS CONVECTION. THUS WHILE I CAN`T RULE OUT
PRECIPITATION...ANY SHOWERS AND THUNDERSTORMS WOULD APPEAR TO HAVE
LIMITED ORGANIZATION AND BE MORE SPOTTY IN COVERAGE WITH THE
GREATEST PROBABILITY ACROSS NE MO INTO WEST CENTRAL IL IN PROXIMITY
TO THE GREATEST INSTABILITY.
IT APPEARS THE MAIN THRUST OF SHOWERS AND THUNDERSTORMS WILL BE ON
SUNDAY AFTERNOON AND EVENING AS THE MAIN UPPER TROF PROGRESSES INTO
THE MID MS VALLEY. DEEP LAYER SHEAR OF 60+ KTS WITHIN THE WARM
SECTOR AND MUCAPES OF 750-1500 J/KG SUGGEST A THREAT OF ORGANIZED
SEVERE STORMS WITH A MIXED MODE IN THE AFTERNOON TRANSITIONING TO
MORE LINEAR DURING THE EVENING. BELIEVE MOST OF THE PRECIPITATION
WILL HAVE EXITED TO THE EAST OF THE CWA ON MONDAY MORNING...WITH
DRIER AND COOLER AIR SPREADING ACROSS THE AREA IN THE WAKE OF THE
COLD FRONTAL PASSAGE.
GLASS
&&
.AVIATION...
ISSUED AT 1150 PM CDT THU APR 12 2012
BAND OF VERY LIGHT RAIN OVER NORTHEAST AND CENTRAL MISSOURI
CONTINUES TO DISSIPATE AS IT STRUGGLES TO MOVE EAST. DON`T
BELIEVE IT WILL HAVE AN IMPACT ON ANY TAF LOCATIONS THE REMAINDER
OF THE NIGHT...SO CONDITIONS FOR THE REST OF THE OVERNIGHT HOURS
SHOULD REMAIN VFR...AOA 5KFT. BELIEVE WE MAY BE SEEING THE VERY
EARLY STAGES OF OUR NEXT THREAT OF SIGNIFICANT PRECIP DEVELOPING
ATTM OVER E KS. 06Z TAF SET IS STICKING WITH MODEL CONSENSUS THAT
DEPICTS A N-S BAND OF SHOWERS AND ELEVATED TSRA DEVELOPING OVER E
KS/W MO DURING THE PREDAWN HOURS...WITH THIS ACTIVITY WORKING IN
MID MO BY AROUND 12Z AND TO NEAR THE MISSISSIPPI RIVER BY MID/LATE
MORNING. FORECAST SOUNDINGS ARE STILL SUGGESTING A LOWERING OF
CIGS AS THE OVERRUNNING/ISENTROPIC ASCENT PRODUCES SEVERAL HOURS
OF STEADY PRECIP. BECAUSE OF THIS TAF FORECASTS DEPICT OCCASIONAL
MVFR CIGS/VSBYS FOR DURING TIME OF HEAVIEST PRECIP. HAVE ALSO
ADDED A MENTION OF THUNDERSTORMS AT ALL TAF LOCATIONS AS A QUICK
PEEK AT THE 00Z RUNS IS SOMEWHAT MORE BULLISH WITH THE
INSTABILITY OVER THE AREA...ESPECIALLY IN CENTRAL MO. PRECIP
SHOULD EXIT E MO/SW IL BY EARLY AFTERNOON...WITH SCT-BKN VFR
CLOUDS 3-5KFT IN THE PRECIPS WAKE AND INTO FRIDAY EVENING. DETAILS
OF FRIDAY NIGHTS CONVECTION STILL FAIRLY MURKY...BUT ATTM IT WOULD
APPEAR THIS THREAT WILL BE AFTER 06Z/14.
SPECIFICS FOR KSTL...CIGS 5-8KFT SHOULD BE THE RULE UNTIL LATE
MORNING FRIDAY...WHEN SHOWERS AND EMBEDDED TSRA ARE EXPECTED TO
ADVECT INTO THE AREA FROM MID MO. ALTHOUGH BELIEVE VFR CONDITIONS
WILL BE THE DOMINATE FLIGHT CATEGORY DURING THE PRECIP...THE
AFOREMENTIONED SATURATION OF THE LOWER LEVELS SHOULD LEAD TO
OCCASIONAL MVFR CIGS/VSBYS FOR SEVERAL HOURS AFTER THE ONSET OF
THE RAIN. 00Z DATA IS JUST A BIT MORE BULLISH WITH THE INSTABILITY
INTO THE REGION...SO THIS TAF SET ALSO INCLUDES MENTION OF THUNDER
AROUND MIDDAY. ONCE RAIN MOVES OUT BY MID AFTERNOON EXPECT VFR
CIGS 3-5KFT...WITH THESE CONDITIONS PERSISTING INTO FRIDAY EVENING.
TRUETT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1159 PM CDT Thu Apr 12 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Short Range (Tonight-Saturday)...
A large upper trough will continue to carve out space over the
western half of the U.S. Periodic shortwave energy will eject from
the base of the trough and combine with increasing moisture and
instability to generate several rounds of strong to severe
thunderstorms across KS/MO and areas to the southwest.
In the near term, a shortwave/vorticity max combo tracking ene
through eastern KS has generated several bands of elevated
convection. Short range convective models such as the HRRR handled
the associated convection/qpf best. Other models underplayed it
although they did a reasonably good job with the h5 vorticity
fields. Activity expected to gradually diminish as it pushes through
the upper level ridge and into drier downstream airmass.
Rest of forecast concerns center on how convective development will
be affected by the elevated mixed layer(EML) that is expected to
overspread the region tomorrow and Saturday. Lacking much of a
boundary to focus on believe this EML will prove to inhibit much of
the daytime convection on Friday and Saturday. Instead will focus on
the regeneration of the southerly low level jet over the Central
Plains both nights as the primary mechanism to initiate and maintain
nighttime convection. The first occurrence will be tonight and favor
using the 12z 4km NMM-WRF for tonights activity. An MCS is expected
to form over central/eastern NE/KS by mid evening and then roll
eastward as the low level jet veers to the southwest. The veering
allows the activity to maintain itself vs running ahead of the main
moisture source. Raised late night pops to categorical most areas.
Convection likely ongoing Friday morning but with it ending from
west to east as the EML begins to work in from the west. Conceptual
model then favors minimal if any convection so have toned down pops
for the rest of Friday/early Friday evening. Upstream redevelopment
convection may need the arrival of another shortwave and reformation
of the low level jet Friday evening. So, will again concentrate
highest pops for Friday night. Max temperatures will be tricky as
they will be greatly affected any residual cloud cover. Northeast MO
will likely be the coolest region.
Saturday should be similar to Friday in that the EML will be in
place and thus inhibit most of the convection. By Saturday a better
dryline may be in place over central KS and as a 110kt swly upper
level jet interacts with a 40kt+ southerly low level jet, expect a
squall-line of severe storms to erupt and advance eastward Saturday
evening. Severe weather could impact the western portion of the CWA
Saturday evening before it weakens. Inspection of NAM BUFR soundings
suggests that if clouds can break up many locations could challenge
the 80 degree mark.
MJ
Medium Range (Sunday through Thursday)...
Sunday...The main wave, in the form a closed upper low, associated
with the broad western CONUS trough will move into the Central
Plains. This will force a cold front into the area late in the day
on Sunday. There is much uncertainty as far as the potential for
severe weather due to ongoing showers that may be persisting across
the area in the morning and the residual cloud cover. 12Z NAM/GFS
Bufr soundings are showing only weak instability however if skies
clear, conditions could destabilize quickly with storms firing along
the cold front or along any remnant outflow boundaries from earlier
convection. This will need to be monitored further for severe
potential. Outside of the severe potential...flooding may also
become a concern over some locations as PWAT values on Sunday are
ranging from 1"-1.5". With periods of rainfall...possibly heavy in
some locations, expected Thursday night through Sunday morning and
additional heavy rain may lead to localized flooding as well as
flooding of small streams and creeks.
Monday - Thursday...We will see a pattern change as we move into the
beginning of next week. The amplified pattern that brought us
showers and thunderstorms through the weekend will become zonal
and thus tranquil. Temperatures on Monday and Tuesday will be
slightly below average with highs ranging from the mid 50s to mid
60s. Wednesday will feature a return to southerly flow out ahead of
a weak cold front. Temperatures will move to near normal with highs
in the 60s however that will be the next chance for showers across
the area as the cold front moves through the late Wednesday into
Wednesday night. By Thursday, high pressure moves back into the area
with highs moving above normal into the upper 60s to mid 70s.
73
&&
.AVIATION...
A few showers and thunderstorms moving across far eastern Kansas at the
moment. Given the isolated nature of the convection, will only
include VCTS for the first couple of hours. Thereafter, short range
guidance suggests the activity across central Kansas will expand and
shift eastward towards the terminals overnight. Rough timing brings
this into the TAF sites by around 09z. Can`t rule out some hail with
these storms as instability and deep layer shear increase coincident
with the arrival of the convection. Otherwise, winds will increase
overnight and become gusty. As the LLJ continues to shift eastward
tonight, LLWS will become a concern and have maintain mentioned until
sunrise.
Deroche
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
638 PM CDT SAT APR 14 2012
.AVIATION...00Z TAF. TOUGH AVIATION FORECAST THIS PERIOD.
THUNDERSTORMS TO THE WEST WILL EVENTUALLY MAKE EN-RODES INTO THE
KGRI AREA LATE THIS EVENING CAUSING MFR TO IFR CONDITIONS AT
TIMES. BUT COVERAGE MAY BE LIMITED IN NATURE...AND STILL SOME
CHANCE THEY MISS KGRI ALL TOGETHER. EVENTUALLY...SOME LATE NIGHT
CLEAR WILL TAKE OVER AS ANY STORMS MOVE EAST...AND IFR CONDITIONS
WILL SETTLE. ON SUNDAY...WRAP AROUND CLOUDS AND COLD FRONT FROM
APPROACHING UPPER LEVEL LOW PRESSURE WILL CAUSE VERY STRONG WINDS
TO DEVELOP IN THE AFTERNOON FROM THE SOUTHWEST TO WEST...AND
INCREASING MID CLOUDS. MAY BE SHOWER IN THERE BUT TOO EARLY TO
REALLY PUT IN THE TAF AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 420 PM CDT SAT APR 14 2012/
SHORT TERM...THROUGH SUNDAY AFTERNOON. THE OBVIOUS CONCERN IS THE
EVOLUTION OF SEVERE CONVECTION OVER AT LEAST THE NEXT 6-8 HOURS.
IN SHORT...THE FIRST ROUND OF STRONG-SEVERE CONVECTION IS IN THE
PROCESS OF EXITING FAR EASTERN PORTIONS OF THE CWA...ESSENTIALLY
BRINGING ROUND 1 TO A CLOSE. THESE STORMS RESULTED IN AT LEAST 3
UNCONFIRMED BRIEF TORNADOES NEAR AND SOUTH OF THE STATE
LINE...ALONG WITH SOME LOCALLY HEAVY RAIN IN EXCESS OF 2 INCHES.
THE CONCERN NOW SHIFTS BACK TO THE FAR WESTERN-SOUTHWESTERN
CWA...AS CLEARING SKIES ARE RAPIDLY DESTABILIZING AREAS CLOSER TO
THE SURFACE DRYLINE FROM SOUTHWEST NEB DOWN ACROSS WESTERN KS. AS
A RESULT...WANT TO EMPHASIZE THAT THIS EVENT IS FAR FROM BEING
OVER.
PARAMETERS FOR ADDITIONAL DEVELOPMENT ARE VERY FAVORABLE FOR
HIGH-END SEVERE...AS THE 110+KT UPPER LEVEL JET STREAK CURRENTLY
MAKING ITS WAY INTO FAR WESTERN KS OVERSPREADS THE AREA.
SUPERCELLS ARE LIKELY WITH 0-6KM BULK SHEAR OF AT LEAST 50KT...AND
WITH LOW LEVEL 0-1KM BULK SHEAR OF 30-40 KT. 0-1KM STORM RELATIVE
HELICITY IS QUITE IMPRESSIVE AS WELL...WITH 300-400+ M2/S2 ACROSS
MUCH OF THE CWA...WHICH COULD ONLY INCREASE INTO THE EVENING HOURS
AS THE LOW LEVEL JET STRENGTHENS. FOLLOWING CONVECTIVE REFLECTIVITY
PROGS FROM LATEST HRRR...ALONG WITH 12Z RUNS OF 4KM WRF-NMM...ALONG
WITH LATEST RUC FIELDS...SIGNIFICANT SURFACE-BASED INSTABILITY
WILL CONTINUE SURGING NORTHEAST INTO THE CWA THROUGH THE NEXT
SEVERAL HOURS WITH LOW LEVEL CAPE IN EXCESS OF 2000 J/KG
PERSISTING WELL INTO THE EVENING. HRRR SUGGESTS A COMBINATION OF
DISCRETE SUPERCELLS AND QUASI LINEAR STORM MODES WILL CONTINUE
WELL INTO THE EVENING...WITH SOUTHERN AND WESTERN PORTIONS OF THE
CWA LIKELY MOST UNDER THE GUN. ALTHOUGH HYDRO ISSUES SEEM TO BE
MINIMAL SO FAR...ANOTHER 1-2 INCHES OF RAIN ACROSS ROUGHLY THE
SOUTHEAST 1/3 OF THE CWA ON TOP OF WHAT FELL EARLIER COULD LEAD TO
SOME ISSUES.
SO FAR...WIND ADVISORY IN EFFECT FOR KS ZONES THROUGH 00Z IS NOT
PANNING OUT VERY WELL WITH CONVECTIVE ACTIVITY INTERFERING...AND
ALTHOUGH NEITHER AN IMMEDIATE CANCELLATION OR AN EXTENSION IS NOT
PLANNED AT THIS TIME...WILL PROBABLY SEE STRONGER SOUTHERLY WINDS
ACTUALLY PICK UP OVERNIGHT AS THE SURFACE LOW DEEPENS TO AROUND
987MB IN THE NORTHEAST CO/SOUTHWEST NEB AREA. SPEAKING OF WIND...A
GOOD CHUNK OF THE CWA WILL ALMOST CERTAINLY NEED AN ADVISORY
DURING THE DAY SUNDAY...AS STRONG WINDS INITIALLY ARE FROM THE
SOUTH...BUT THEN FROM THE WEST AND NORTHWEST BEHIND THE COLD
FRONT. INSERTED A STRONG WIND MENTION INTO THE GRIDS AND HAZARDOUS
WEATHER OUTLOOK...BUT WITH EVERYTHING ELSE GOING ON TODAY WILL
DEFER TO MIDNIGHT SHIFT TO PULL THE TRIGGER ON THE NEXT WIND
HEADLINE...WHICH WILL UNDOUBTEDLY BE MORE ROBUST THAN THE CURRENT
ONE.
AS FOR STORM CHANCES LATE TONIGHT...ONLY HAVE 20-30 PERCENT
CHANCES POST-06Z...AND ALTHOUGH THE VAST MAJORITY OF THE CWA
SHOULD BE FREE OF SEVERE WEATHER BY THEN...COULD FORESEE A
MARGINALLY SEVERE STORMS HANGING ON IN NORTHERN ZONES LATE INTO
THE NIGHT. SHOULD BE A LULL IN PRECIPITATION ACROSS MUCH OF THE
CWA LATE TONIGHT INTO SUNDAY MORNING AS THE SYNOPTIC DRY SLOT
SURGES IN...BUT RAIN SHOWERS WILL GRADUALLY SPREAD INTO THE CWA
FROM WEST TO EAST WRAPPING AROUND THE DEPARTING LOW. THE
COMBINATION OF ANY RAIN SHOWERS WITH THE STRONG WINDS WILL MAKE
THE FORECAST HIGHS IN THE MID 50S TO MID 60S FEEL COLDER THAN IT
MAY SOUND.
LONG TERM...SUNDAY EVENING THROUGH NEXT SATURDAY. OVERALL FEW
NOTABLE CHANGES MADE TO PREVIOUS FORECAST...WITH FORECAST BASED ON
A GENERAL BLEND OF THE 12Z ECMWF/GFS.
STARTING OFF RIGHT AWAY SUNDAY EVENING...A WIND ADVISORY MAY
CONTINUE FOR A FEW MORE HOURS ESPECIALLY IN NORTHEAST AREAS...BUT
LIKELY NOT BEYOND 03Z AS THE STRONG SURFACE LOW PULLS GRADUALLY
AWAY ACROSS SOUTHERN MN. LINGERED A SLIGHT CHANCE OF LIGHT SHOWERS
INTO THE EVENING HOURS MAINLY ACROSS THE NORTHEAST...BUT DRY AFTER
MIDNIGHT. HEADING INTO MONDAY...LEFT THE MORNING DRY BUT HAVE
20-30 PERCENT CHANCES FOR SHOWERS IN THE AFTERNOON AS A TRAILING
SHORTWAVE TRACKS OUT OF SOUTHERN SD INTO NORTHERN NEB. NEXT SLIGHT
CHANCE FOR SHOWERS ARRIVES IN NORTHEAST COUNTIES FOR TUESDAY NIGHT
AS THE NEXT QUICK MOVING WAVE PASSES BY IN QUASI-ZONAL FLOW ALOFT.
A FAIRLY ACTIVE UPPER PATTERN CONTINUES INTO THE LATTER PART OF
THE WEEK...AND MAINTAINED 20-30 PERCENT CHANCES FOR SHOWERS/STORMS
FROM THURS INTO THURS NIGHT AS THE NEXT WAVE CROSSES THE REGION.
AT THIS TIME...SEVERE WEATHER THREAT APPEARS LOW. BEYOND THURSDAY
NIGHT...MAINTAINED A DRY FORECAST THROUGH SATURDAY AS THERE ARE
SUGGESTIONS OF AT LEAST WEAK SHORTWAVE RIDGING BUILDING INTO THE
PLAINS.
TEMPERATURE WISE THROUGH THE EXTENDED...HAVE MOST DAYS IN THE
LOW-MID 70S FOR HIGHS...EXCEPT FOR COOLER UPPER 50S-LOW 60S ON
MONDAY. AS FOR OVERNIGHT LOWS...COULD EVENTUALLY NEED TO INSERT
SOME FROST WORDING FOR SUNDAY NIGHT AND/OR MONDAY NIGHT WITH LOWS
IN THE MID-UPPER 30S...ALTHOUGH BREEZES MAY REMAIN JUST STRONG
ENOUGH TO PRECLUDE MUCH DEVELOPMENT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1026 PM EDT SAT APR 14 2012
.SYNOPSIS...
A WARM FRONT WILL PASS THROUGH THE REGION TONIGHT INTO
SUNDAY...ACCOMPANIED BY A CHANCE OF SHOWERS AND PERHAPS
THUNDER...WHICH WILL SHIFT NORTHWARD WITH TIME. TEMPERATURES
WILL CONTINUE TO SURGE WARMER SUNDAY AND ESPECIALLY MONDAY...TO
THE TUNE OF 25 DEGREES OR SO ABOVE NORMAL. A COLD FRONT WILL PASS
MONDAY AFTERNOON INTO EVENING...WITH SHOWERS AND A CHANCE OF
THUNDER. TEMPERATURES RETURN TO MORE SEASONABLE LEVELS FOR
MIDWEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
1010 PM UPDATE...
AS DISCUSSED IN THE PREVIOUS UPDATE...SHOWERS EXITING THE OHIO
VLY CONTINUE TO MOVE ACROSS ACROSS SOUTHWESTERN PA THIS EVENING.
CONSIDERING THAT THE LOW-LEVEL JET IS EXPECTED TO VEER TOWARDS A
WESTERLY DIRECTION OVERNIGHT...CURRENT THINKING IS THAT MUCH OF
THE FORECAST AREA WILL NOT BE IMPACTED BY THIS FEATURE. AS A
RESULT...HAVE TRIMMED POPS EVEN FURTHER WITH THE LATEST UPDATE.
CLOSER TO HOME...LATEST RADAR TRENDS STILL SHOWING ISOLATED LIGHT
SHOWER ACTIVITY MOVING THROUGH THE TWIN TIERS AND NORTHEAST
PA...HOWEVER WITH DEWPOINT DEPRESSIONS STILL REMAINING ANYWHERE
BETWEEN 10-20 DEGREES...EXPECT NOTHING MORE THAN A SPRINKLE OR
LGT SHOWER AT BEST. IN GENERAL...HAVE MAINTAINED SLGT CHC TO CHC
MENTION FROM THE TWIN TIERS SOUTH. ASIDE FROM MINOR TEMP/DEWPOINT
ADJUSTMENTS...NO OTHER CHANGES NEEDED AT THIS TIME.
750 PM UPDATE...AS STATED IN THE PREVIOUS NEAR TERM
DISCUSSION...CURRENT ACTIVITY MOVING OVER THE FORECAST AREA IS
HAVING LITTLE IMPACT AS DEWPOINT DEPRESSIONS REMAIN ANYWHERE
BETWEEN 20-25 DEGREES EARLY THIS EVENING. AS THIS INITIAL SHIELD
EXITS STAGE RIGHT...ATTENTION WILL THEN SHIFT TO NEXT AREA OF
PRECIP NOW ENTERING WESTERN PA FROM THE OHIO VLY. QUICK LOOK AT
REGIONAL RADAR MOSAIC SHOWS THIS ACTIVITY MOVING EAST THIS EVENING
IN A DUE EASTERLY MOTION...SUGGESTING MUCH OF THIS ACTIVITY WILL
REMAIN SOUTH OF THE NY/PA STATE LINE..AND POSSIBLY EVEN THE ENTIRE
CWA. LATEST HRRR HIGH RES SIMULATED REFLECTIVITY ALONG WITH THE
LATEST RUC QPF FCST SUPPORT THIS LINE OF THINKING AS THE LOW-LEVEL
JET VEERS AND BECOMES NEARLY WESTERLY OVERNIGHT. BASED ON
THIS...FEEL LITTLE IF ANY PRECIP WILL OCCUR FROM THE FINGER LAKES
NORTH...AND WE HAVE TRIMMED POPS ACROSS THESE AREAS ACCORDINGLY.
WE MAY HAVE TO CONTINUE TO TRIMMING POPS FROM NORTH TO SOUTH WITH
THE NEXT UPDATE BASED ON CURRENT TRAJECTORIES BUT WILL CONTINUE TO
MONITOR TRENDS BEFORE MAKING ANY WHOLESALE CHANGES. ASIDE FROM
THAT...JUST SOME MINOR COSMETIC CHANGES TO TEMPS AND DEWPOINTS.
415 PM UPDATE...DESPITE BUSY LOOKING RADAR WITH INCOMING
SHOWERS...VERY DRY LOW LEVELS ARE MAKING THE TOP DOWN MOISTENING
PROCESS GRADUAL...WITH DEW POINT DEPRESSIONS OF ROUGHLY 30 DEGREES
WEST TO ALMOST 40 DEGREES EAST. ONLY EXPECTING SPRINKLES TO
ENCROACH LATE AFTERNOON TO EARLY EVENING...BEFORE 850MB JET CAN
BRING IN ENOUGH MOISTURE FOR MORE SIGNIFICANT RAIN CHANCES. LATEST
MODEL RUNS ARE AGREEING THAT AN EMBEDDED NORTHERN STREAM SHORTWAVE
WILL DROP WNW TO ENE THROUGH THE AREA 01Z-04Z. MODELS DISAGREE
DETAILS OF SHOWER ACTIVITY...BUT CONSENSUS HAS DEFINITELY SHIFTED
TOWARDS FAVORING SOUTHWESTERN ZONES...BECAUSE OF POSITIONING OF
WARM FRONT...AND EFFECT OF DRY AIR FARTHER NORTH AND EAST.
REGARDLESS...WAVE HEADS OUT SHORTLY AFTER MIDNIGHT FOR A RELATIVE
LULL IN ACTIVITY DURING THE PREDAWN HOURS. POPS HAVE BEEN ADJUSTED
ACCORDINGLY. ALSO...WITH AMOUNT OF CLOUD COVER AND GOOD MIXING...I
WENT WELL ABOVE MAV GUIDANCE AND SLIGHTLY ABOVE MET GUIDANCE FOR
LOW TEMPERATURES.
SUNDAY IS NOT LOOKING VERY FAVORABLE FOR CONVECTION...COMPARED TO
EARLIER MODEL RUNS. SHALLOW WARM FRONT...WITH SURGING HEIGHTS
ALOFT YET DELAYED RESPONSE NEAR THE SURFACE...WILL ALLOW FOR AN
INHIBITIVE CAP TO DEVELOP ABOVE LOWERING CLOUD COVER LATE TONIGHT
INTO SUNDAY MORNING. CLOUD COVER WILL LIMIT AMOUNT OF WARMING IN
THE MORNING. BY THE TIME SURFACE FRONT RETREATS NORTHWARD SUNDAY
AFTERNOON AND LOW CLOUDS START MIXING OUR...CAP WILL BE IN PLACE.
THE OLD ADAGE...NEVER TRUST A WARM FRONT...APPLIES HERE THOUGH. SO I
STILL BRING AN AXIS OF CHANCE POPS NORTHWARD WITH THE WARM FRONT
DURING THE DAY SUNDAY...ERADICATING FROM THE SOUTH DURING THE
AFTERNOON. BECAUSE OF SHALLOW WARM FRONT/CLOUD COVER...I LOWERED
TEMPERATURES SOMEWHAT FOR SUNDAY...THOUGH IT WILL STILL TURN OUT
AT LEAST A FEW TO SEVERAL DEGREES WARMER THAN TODAY /SATURDAY/.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
415 PM UPDATE...DRYING OUT WITH STRONG CAP AMIDST IMPRESSIVE WARM
SECTOR SUNDAY NIGHT. I AGAIN WENT ABOVE GUIDANCE FOR LOWS MONDAY
MORNING...WHICH WILL FEEL EERILY SUMMER-LIKE AT DAWN. THE WARM HEAD
START...850MB TEMPERATURES 2 TO 3 STANDARD DEVIATIONS ABOVE
NORMAL...AND WITH SUNSHINE FOR AT LEAST A MAJORITY OF THE
DAY...WILL YIELD HIGHS ROUGHLY 25 OR SO DEGREES ABOVE NORMAL. THIS
WILL BE WITHIN A FEW TO SEVERAL DEGREES OF RECORD DAILY
HIGHS...THOUGH ACTUALLY BREAKING THE RECORDS IS CURRENTLY NOT
FORECAST /YET/.
MODELS HAVE COME INTO GOOD AGREEMENT ON TIMING OF INCOMING FRONT
MID TO LATE AFTERNOON IN THE WESTERN CWA MONDAY...SLOWING DOWN
WHILE BECOMING MORE FLOW-PARALLEL INTO MONDAY EVENING AS IT EDGES
EASTWARD. STRONG CAP EARLY IN DAY...ERODES TO POINT OF BREAKING AS
FRONT MOVES IN. AT FIRST GLANCE...FRONT APPEARS TO TAKE ANAFRONT
NATURE...AND ACTUALLY EVENTUALLY DOES. HOWEVER...DURING THE DAY
MONDAY...CLOSER INSPECTION REVEALS THAT MOISTURE IS POOLED
IMMEDIATELY ALONG FRONT RATHER THAN BEHIND...AND THERE IS ENOUGH
INSTABILITY AND SHEAR FOR THUNDERSTORMS WHICH COULD BE GUSTY /AT
LEAST IN THE WESTERN HALF OF THE AREA/. THIS WILL BEAR WATCHING IN
COMING MODEL RUNS. FOR NOW...SPC TALKS ABOUT OUR SITUATION WITHIN
THE TEXT OF THE DAY 3 OUTLOOK...BUT NOT ENOUGH CONFIDENCE TO
INCLUDE WITHIN SLIGHT RISK FOR SEVERE. I AGREE THAT UNTIL THERE IS
HIGHER CONFIDENCE IN THE INSTABILITY/CAPE EXISTING ALONG THE
FRONT...TOO EARLY TO MENTION SEVERE POTENTIAL WITHIN THE HAZARDOUS
WEATHER OUTLOOK.
DRAMATIC TEMPERATURE FALL INBOUND FOR TUESDAY BEHIND THE
FRONT...YET ONLY BACK TO NEAR SEASONAL VALUES. COLUMN APPEARS TOO
DRY IN THE MODELS TO SUPPORT MENTIONABLE POPS...SO I TOOK WHAT
LITTLE WE HAD IN THE FORECAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
GNRLY ZONAL FLOW IS FCST IN THE MEDIUM RNG. HI PRES IS XPCTD TO BRING
FAIR WEATHER ON WED...WITH ANOTHER FNTL PSSG ON THU. LATE IN THE
PD...DEEPENING TROF MOVG INTO THE OH VLY MAY BRING UNSETTLED WX
FRI INTO SAT. NO SIG CHGS TO HPC GUIDANCE OTHER THAN BEING A BIT
MORE OPTIMISTIC ON CLD CVR TUE NGT INTO WED.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
00Z SUN UPDATE... TOUGH CALL OVERNIGHT WITH REGARDS TO PCPN.
CURRENT INDICATIONS ARE THAT MOST OF THE RAIN WILL STAY S OF OUR
TERMINALS...OTHER THAN A FEW SPRINKLES AT KELM/KAVP MAINLY. AS A
RESULT...VSBY`S SHOULD STAY UNRESTRICTED.
HOWEVER...IT STILL APPEARS THAT LWR CIGS WILL OVERSPREAD THE RGN
FROM W TO E LATER THIS EVE...THEN PERSIST TIL THE MIDDAY HRS SUN.
WE`LL BRING IN MVFR CIGS IN THE 04-07Z TIME FRAME...THEN INDICATE
SOME IMPROVEMENT BACK TO VFR IN THE 14-17Z PD SUN.
LIGHT VRBL WINDS (AOB 5 KT) OVERNIGHT...WILL BECOME SWLY BY EARLY
SUN AFTN...INCRG TO ARND 10 KT.
.OUTLOOK...
SUN NGT...VFR.
MON...VFR...BUT A BAND OF MVFR CIGS/SHRA PSBL WITH FROPA LATE MON OR
MON EVNG.
MON NGT THRU WED NGT...VFR.
THU...SCT MVFR IN -SHRA.
&&
.FIRE WEATHER...
FIRE SENSITIVE CONDITIONS AGAIN THIS AFTERNOON...WITH AREA WIDE
RELATIVE HUMIDITY WELL BELOW 30 PERCENT FOR MOST OF THE AREA...AND
GUSTS NEAR 20 MPH IN THE POCONOS. FINE FUELS CONTINUE TO REMAIN
VERY DRY RUNNING BETWEEN 5 AND 8 PERCENT. HOWEVER...FIRE THREAT
IS NOW BEING MITIGATED BY THICKENING HIGH CLOUDS THE REMAINDER OF
THE AFTERNOON...WHICH WILL LIMIT MIXING DOWN OF WINDS. WITH GUSTS
NOT EXPECTED TO CONSISTENTLY REACH CRITERIA LEVELS...NO RED FLAG
NEEDED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...CMG/MDP
SHORT TERM...MDP
LONG TERM...
AVIATION...MLJ
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
756 PM EDT SAT APR 14 2012
.SYNOPSIS...
A WARM FRONT WILL PASS THROUGH THE REGION TONIGHT INTO
SUNDAY...ACCOMPANIED BY A CHANCE OF SHOWERS AND PERHAPS
THUNDER...WHICH WILL SHIFT NORTHWARD WITH TIME. TEMPERATURES
WILL CONTINUE TO SURGE WARMER SUNDAY AND ESPECIALLY MONDAY...TO
THE TUNE OF 25 DEGREES OR SO ABOVE NORMAL. A COLD FRONT WILL PASS
MONDAY AFTERNOON INTO EVENING...WITH SHOWERS AND A CHANCE OF
THUNDER. TEMPERATURES RETURN TO MORE SEASONABLE LEVELS FOR
MIDWEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
750 PM UPDATE... AS STATED IN THE PREVIOUS NEAR TERM
DISCUSSION...CURRENT ACTIVITY MOVING OVER THE FORECAST AREA IS
HAVING LITTLE IMPACT AS DEWPOINT DEPRESSIONS REMAIN ANYWHERE
BETWEEN 20-25 DEGREES EARLY THIS EVENING. AS THIS INITIAL SHIELD
EXITS STAGE RIGHT...ATTENTION WILL THEN SHIFT TO NEXT AREA OF
PRECIP NOW ENTERING WESTERN PA FROM THE OHIO VLY. QUICK LOOK AT
REGIONAL RADAR MOSAIC SHOWS THIS ACTIVITY MOVING EAST THIS EVENING
IN A DUE EASTERLY MOTION...SUGGESTING MUCH OF THIS ACTIVITY WILL
REMAIN SOUTH OF THE NY/PA STATE LINE..AND POSSIBLY EVEN THE ENTIRE
CWA. LATEST HRRR HIGH RES SIMULATED REFLECTIVITY ALONG WITH THE
LATEST RUC QPF FCST SUPPORT THIS LINE OF THINKING AS THE LOW-LEVEL
JET VEERS AND BECOMES NEARLY WESTERLY OVERNIGHT. BASED ON
THIS...FEEL LITTLE IF ANY PRECIP WILL OCCUR FROM THE FINGER LAKES
NORTH...AND WE HAVE TRIMMED POPS ACROSS THESE AREAS ACCORDINGLY.
WE MAY HAVE TO CONTINUE TO TRIMMING POPS FROM NORTH TO SOUTH WITH
THE NEXT UPDATE BASED ON CURRENT TRAJECTORIES BUT WILL CONTINUE TO
MONITOR TRENDS BEFORE MAKING ANY WHOLESALE CHANGES. ASIDE FROM
THAT...JUST SOME MINOR COSMETIC CHANGES TO TEMPS AND DEWPOINTS.
415 PM UPDATE...DESPITE BUSY LOOKING RADAR WITH INCOMING
SHOWERS...VERY DRY LOW LEVELS ARE MAKING THE TOP DOWN MOISTENING
PROCESS GRADUAL...WITH DEW POINT DEPRESSIONS OF ROUGHLY 30 DEGREES
WEST TO ALMOST 40 DEGREES EAST. ONLY EXPECTING SPRINKLES TO
ENCROACH LATE AFTERNOON TO EARLY EVENING...BEFORE 850MB JET CAN
BRING IN ENOUGH MOISTURE FOR MORE SIGNIFICANT RAIN CHANCES. LATEST
MODEL RUNS ARE AGREEING THAT AN EMBEDDED NORTHERN STREAM SHORTWAVE
WILL DROP WNW TO ENE THROUGH THE AREA 01Z-04Z. MODELS DISAGREE
DETAILS OF SHOWER ACTIVITY...BUT CONSENSUS HAS DEFINITELY SHIFTED
TOWARDS FAVORING SOUTHWESTERN ZONES...BECAUSE OF POSITIONING OF
WARM FRONT...AND EFFECT OF DRY AIR FARTHER NORTH AND EAST.
REGARDLESS...WAVE HEADS OUT SHORTLY AFTER MIDNIGHT FOR A RELATIVE
LULL IN ACTIVITY DURING THE PREDAWN HOURS. POPS HAVE BEEN ADJUSTED
ACCORDINGLY. ALSO...WITH AMOUNT OF CLOUD COVER AND GOOD MIXING...I
WENT WELL ABOVE MAV GUIDANCE AND SLIGHTLY ABOVE MET GUIDANCE FOR
LOW TEMPERATURES.
SUNDAY IS NOT LOOKING VERY FAVORABLE FOR CONVECTION...COMPARED TO
EARLIER MODEL RUNS. SHALLOW WARM FRONT...WITH SURGING HEIGHTS
ALOFT YET DELAYED RESPONSE NEAR THE SURFACE...WILL ALLOW FOR AN
INHIBITIVE CAP TO DEVELOP ABOVE LOWERING CLOUD COVER LATE TONIGHT
INTO SUNDAY MORNING. CLOUD COVER WILL LIMIT AMOUNT OF WARMING IN
THE MORNING. BY THE TIME SURFACE FRONT RETREATS NORTHWARD SUNDAY
AFTERNOON AND LOW CLOUDS START MIXING OUR...CAP WILL BE IN PLACE.
THE OLD ADAGE...NEVER TRUST A WARM FRONT...APPLIES HERE THOUGH. SO I
STILL BRING AN AXIS OF CHANCE POPS NORTHWARD WITH THE WARM FRONT
DURING THE DAY SUNDAY...ERADICATING FROM THE SOUTH DURING THE
AFTERNOON. BECAUSE OF SHALLOW WARM FRONT/CLOUD COVER...I LOWERED
TEMPERATURES SOMEWHAT FOR SUNDAY...THOUGH IT WILL STILL TURN OUT
AT LEAST A FEW TO SEVERAL DEGREES WARMER THAN TODAY /SATURDAY/.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
415 PM UPDATE...DRYING OUT WITH STRONG CAP AMIDST IMPRESSIVE WARM
SECTOR SUNDAY NIGHT. I AGAIN WENT ABOVE GUIDANCE FOR LOWS MONDAY
MORNING...WHICH WILL FEEL EERILY SUMMER-LIKE AT DAWN. THE WARM HEAD
START...850MB TEMPERATURES 2 TO 3 STANDARD DEVIATIONS ABOVE
NORMAL...AND WITH SUNSHINE FOR AT LEAST A MAJORITY OF THE
DAY...WILL YIELD HIGHS ROUGHLY 25 OR SO DEGREES ABOVE NORMAL. THIS
WILL BE WITHIN A FEW TO SEVERAL DEGREES OF RECORD DAILY
HIGHS...THOUGH ACTUALLY BREAKING THE RECORDS IS CURRENTLY NOT
FORECAST /YET/.
MODELS HAVE COME INTO GOOD AGREEMENT ON TIMING OF INCOMING FRONT
MID TO LATE AFTERNOON IN THE WESTERN CWA MONDAY...SLOWING DOWN
WHILE BECOMING MORE FLOW-PARALLEL INTO MONDAY EVENING AS IT EDGES
EASTWARD. STRONG CAP EARLY IN DAY...ERODES TO POINT OF BREAKING AS
FRONT MOVES IN. AT FIRST GLANCE...FRONT APPEARS TO TAKE ANAFRONT
NATURE...AND ACTUALLY EVENTUALLY DOES. HOWEVER...DURING THE DAY
MONDAY...CLOSER INSPECTION REVEALS THAT MOISTURE IS POOLED
IMMEDIATELY ALONG FRONT RATHER THAN BEHIND...AND THERE IS ENOUGH
INSTABILITY AND SHEAR FOR THUNDERSTORMS WHICH COULD BE GUSTY /AT
LEAST IN THE WESTERN HALF OF THE AREA/. THIS WILL BEAR WATCHING IN
COMING MODEL RUNS. FOR NOW...SPC TALKS ABOUT OUR SITUATION WITHIN
THE TEXT OF THE DAY 3 OUTLOOK...BUT NOT ENOUGH CONFIDENCE TO
INCLUDE WITHIN SLIGHT RISK FOR SEVERE. I AGREE THAT UNTIL THERE IS
HIGHER CONFIDENCE IN THE INSTABILITY/CAPE EXISTING ALONG THE
FRONT...TOO EARLY TO MENTION SEVERE POTENTIAL WITHIN THE HAZARDOUS
WEATHER OUTLOOK.
DRAMATIC TEMPERATURE FALL INBOUND FOR TUESDAY BEHIND THE
FRONT...YET ONLY BACK TO NEAR SEASONAL VALUES. COLUMN APPEARS TOO
DRY IN THE MODELS TO SUPPORT MENTIONABLE POPS...SO I TOOK WHAT
LITTLE WE HAD IN THE FORECAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
GNRLY ZONAL FLOW IS FCST IN THE MEDIUM RNG. HI PRES IS XPCTD TO BRING
FAIR WEATHER ON WED...WITH ANOTHER FNTL PSSG ON THU. LATE IN THE
PD...DEEPENING TROF MOVG INTO THE OH VLY MAY BRING UNSETTLED WX
FRI INTO SAT. NO SIG CHGS TO HPC GUIDANCE OTHER THAN BEING A BIT
MORE OPTIMISTIC ON CLD CVR TUE NGT INTO WED.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
00Z SUN UPDATE... TOUGH CALL OVERNIGHT WITH REGARDS TO PCPN.
CURRENT INDICATIONS ARE THAT MOST OF THE RAIN WILL STAY S OF OUR
TERMINALS...OTHER THAN A FEW SPRINKLES AT KELM/KAVP MAINLY. AS A
RESULT...VSBY`S SHOULD STAY UNRESTRICTED.
HOWEVER...IT STILL APPEARS THAT LWR CIGS WILL OVERSPREAD THE RGN
FROM W TO E LATER THIS EVE...THEN PERSIST TIL THE MIDDAY HRS SUN.
WE`LL BRING IN MVFR CIGS IN THE 04-07Z TIME FRAME...THEN INDICATE
SOME IMPROVEMENT BACK TO VFR IN THE 14-17Z PD SUN.
LIGHT VRBL WINDS (AOB 5 KT) OVERNIGHT...WILL BECOME SWLY BY EARLY
SUN AFTN...INCRG TO ARND 10 KT.
.OUTLOOK...
SUN NGT...VFR.
MON...VFR...BUT A BAND OF MVFR CIGS/SHRA PSBL WITH FROPA LATE MON OR
MON EVNG.
MON NGT THRU WED NGT...VFR.
THU...SCT MVFR IN -SHRA.
&&
.FIRE WEATHER...
FIRE SENSITIVE CONDITIONS AGAIN THIS AFTERNOON...WITH AREA WIDE
RELATIVE HUMIDITY WELL BELOW 30 PERCENT FOR MOST OF THE AREA...AND
GUSTS NEAR 20 MPH IN THE POCONOS. FINE FUELS CONTINUE TO REMAIN
VERY DRY RUNNING BETWEEN 5 AND 8 PERCENT. HOWEVER...FIRE THREAT
IS NOW BEING MITIGATED BY THICKENING HIGH CLOUDS THE REMAINDER OF
THE AFTERNOON...WHICH WILL LIMIT MIXING DOWN OF WINDS. WITH GUSTS
NOT EXPECTED TO CONSISTENTLY REACH CRITERIA LEVELS...NO RED FLAG
NEEDED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...CMG/MDP
SHORT TERM...MDP
LONG TERM...
AVIATION...MLJ
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
954 PM EDT SAT APR 14 2012
.SYNOPSIS...
WARM FRONT MOVES NORTH OF THE AREA TONIGHT. THIS LEAVES WARMER
AIR IN PLACE FOR SUNDAY. A COLD FRONT CROSSES LATE MONDAY. HIGH
PRESSURE FOLLOWS THROUGH THE END OF WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
SENT A QUICK UPDATE TO ACCELERATE THE EXODUS OF SHOWERS ASSOCIATED
WITH WARM FRONT LIFTING NORTH ACROSS THE NORTHERN SECTIONS DURING
THE EVENING HOURS. ADJUSTED TEMPERATURES PER LATEST SFC OBS AND
LAV GUIDANCE.
PREVIOUS DISCUSSION BELOW...
WARM FRONT LIFTS N THROUGH THE OHIO VALLEY THROUGH TONIGHT.
SHOWERS ALONG THE INITIAL THETA E FEED TODAY WERE HARD PRESSED TO
MEASURE ON ACCOUNT OF DRY AIR FROM THE LOWER INTO THE MIDDLE
LEVELS...H7-H6. CONVECTIVE COMPLEXES MOVING ALONG THE SOUTHERN
EDGE OF THE WARM FRONT SHOULD GRADUALLY SHIFT N WITH THE FRONT
TONIGHT INTO SUN. THE FIRST WAS MOVING INTO THE CWA FROM THE W
EARLY THIS AFTERNOON. THE SOUTHERN EDGE OF THIS BATCH SHOULD
CONTINUE TO PUSH N...KEEPING POPS LOW ACROSS THE SE HALF OF THE
AREA. THE SECOND..IN INDIANA EARLY THIS AFTERNOON...WILL TAKE A
MORE NORTHERN TRACK...SO HAVE HIGH POPS ACROSS NORTHERN TIER
COUNTIES TONIGHT.
SAVE FOR LINGERING PRECIPITATION IN THE NORTHERN MOUNTAINS OF WV SUN
MORNING...ALL THE ACTIVITY WILL SHIFT N OF THE AREA SUN...AS THE
WARM SECTOR ENVELOPES THE ENTIRE AREA BY LATE MORNING.
ADJUSTED HIGH TEMPERATURES FOR THIS AFTERNOON BASED ON TRENDS TO
BETTER REFLECT N-S DIFFERENCE. BLENDED IN BIAS CORRECTED MET AND
MAV ON LOWS TONIGHT...THE MAIN EFFECT BEING TO LOWER LOWS IN THE
EASTERN VALLEYS WITH SOME DECOUPLING THERE. BLENDED IN THE MET FOR
HIGHS SUN...RAISING VALUES A BIT IN SUNSHINE AND STRONG SW FLOW.
MIXING RATIO IN MIXED LAYER SUGGESTS DEW POINTS OF GENERALLY 50 OR
BETTER SUN AFTERNOON...BUT OPTED TO BLEND IN LOWER MET VALUES SO
STILL HAVE RH VALUES FLIRTING WITH 30 PERCENT THRESHOLD. WITH THE
GUSTY WINDS AND RATHER DRY CONDITIONS...WILL LIKELY NEED FIRE SPS
SUN FOR ENHANCED THREAT.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
UNSETTLED WEATHER RETURNS TO THE CWA ON MONDAY AS A COLD FRONTAL
BOUNDARY PUSHES EAST THROUGH THE REGION LATE MONDAY...ENDING UP TO
THE EAST OF THE MOUNTAINS BY LATE MONDAY NIGHT/EARLY TUESDAY. STILL
LOOKING TO BE A LOW QPF EVENT...AS THE FRONTAL BOUNDARY AND
ASSOCIATED MOISTURE RACE THROUGH THE REGION. AT THIS
POINT...INSTABILITY APPEARS TO BE RATHER WEAK...AND A SEVERE THREAT
IS NOT EXPECTED. DEPENDING ON THE EXACT TIMING OF THE FRONT...COULD
BE A NON DIURNAL TREND IN TEMPERATURES ON MONDAY...MAINLY UP NORTH.
HIGH PRESSURE WILL THEN BUILD IN FROM THE NORTH FOR
TUESDAY...KEEPING MUCH OF THE FORECAST AREA DRY...ALTHOUGH THERE
WILL BE SOME CLOUD COVER HANGING AROUND FROM A SHORTWAVE THAT WILL
BEGIN TO MOVE NORTHEAST TOWARDS THE REGION FROM THE SOUTH MID WEEK.
A BIT OF UNCERTAINTY CONCERNING THE EXACT TRACK OF THIS WAVE...BUT
FOR NOW...MAINTAINED A DRY FORECAST FOR TUESDAY NIGHT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AT THE OUTSET OF THE PERIOD A WEAK FRONTAL BOUNDARY WILL BE STALLED
TO THE SOUTHEAST OF THE FORECAST AREA ROUGHLY FROM SE VIRGINIA
THROUGH THE CAROLINAS. EXTENDED OPERATIONAL MODELS DIVERGE WITH THE
STRENGTH/EVOLUTION/PLACEMENT OF A SHORTWAVE TROUGH LOCATED OVER THE
SOUTHERN MISS VALLEY WHICH IS PROGGED TO MOVE NORTHEAST AROUND UPPER
LEVEL RIDGE OVER SE CONUS TOWARDS THE AREA. ENSEMBLE PRODUCTS SEEM
TO LOOSELY SUPPORT THE GFS SOLN IN KEEPING THIS SHORT WAVE TROUGH
LESS AMPLIFIED AND MORE PROGRESSIVE...WITH MOISTURE SOUTH OF THE
AREA. LATEST NAM AT 84HRS ALSO SUPPORTS THE LESSER AMPLIFIED
SCENARIO SO WILL LEAN THE WED/THU PORTION OF THE FORECAST IN THIS
DIRECTION WITH REGARD TO THIS SPECIFIC FEATURE AND SUBSEQUENT DRIER
SOLUTION. MEANWHILE ALSO ON THURSDAY..THE GFS DEPICTS A RELATIVELY
DEEP TROUGH TRANSLATING ACROSS THE NORTHERN CONUS WITH ATTENDANT SFC
LOW/COLD FRONT MOVING THROUGH THE AREA THURSDAY. EC SOLUTION KEEPS
FLOW ZONAL ACROSS NORTHERN CONUS WITH THE WEAKENING FRONT SNEAKING
INTO THE NORTHERN ZONES BEFORE QUICKLY RETREATING NORTHWARD. GEFS
SUPPORTS ZONAL EC SOLN AND HAVE TRENDED FCST IN THIS DIRECTION BUT
HAVE ADDED SLIGHT CHANCE POPS ACROSS NORTH TO ACCOUNT FOR POSSIBLE
MODEL DIFFERENCES. BETTER CHANCES FOR PRECIP ARRIVE OVER THE WEEKEND
AS GFS/EC AND ENSEMBLES ALL DEPICT A SHORTWAVE APPROACHING AREA WITH
USUAL VARYING STRENGTH/POSITIONING DIFFERENCES.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
RADAR IMAGES SHOW BATCH OF RAIN SHOWERS EXITING THE NORTHERN SITES
THIS EVENING. DESPITE OF PERIODS OF RAIN DURING THE AFTERNOON AND
EVENING HOURS...FOR FORMATION WAS NOT INCLUDED IN TAF PER GUSTY
WINDS ALOFT AS SUGGESTED BY NAM12 AND RUC13 BOUNDARY LAYER WIND
FIELDS.
THEREFORE...VFR CONDITIONS CAN BE EXPECTED EVERYWHERE THROUGH THE
TAF PERIOD.
SFC SOUTHWEST WINDS WILL BECOME GUSTY ON SUNDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: NONE.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SUN 04/15/12
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EDT 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H L L H H H H H H H H H
CKB CONSISTENCY M H M H H H H H H H H H
AFTER 00Z MONDAY...
NO IFR EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50/SL
NEAR TERM...ARJ/TRM
SHORT TERM...SL
LONG TERM...50
AVIATION...ARJ
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1118 AM MDT FRI APR 13 2012
.AVIATION...18Z TAF FORECAST
SCATTERED RAIN SHOWERS WITH AN ISOLATED THUNDERSTORM ARE POSSIBLE
THIS AFTERNOON OVER NORTHEASTERN WYOMING AND THE BLACK HILLS. MVFR
CIGS WILL BE POSSIBLE IN AND AROUND SHOWERS/STORMS. CONVECTION
SHOULD END THIS EVENING AFT 03Z BEFORE ANOTHER DISTURBANCE PUSHES
TOWARD THE AREA LATE TONIGHT. BETWEEN SYSTEMS VFR CONDITIONS ARE
EXPECTED. BY 12Z SATURDAY...MVFR CIGS WILL RETURN TO NORTHEASTERN
WYOMING...THE BLACK HILLS...AND SOUTHERN PORTIONS OF SOUTH DAKOTA.
&&
.PREV DISCUSSION... /ISSUED 904 AM MDT FRI APR 13 2012/
UPDATE...A WEAK SHORT-WAVE RIDGE OVER THE CWA THIS MORNING HAS
ALLOWED FOR CLEARING SKIES AS A VIGOROUS SHORT-WAVE TROUGH WAS
JUST EAST OF THE CWA...TAKING PRECIPITATION WITH IT. A SLOW-MOVING
LOW-AMPLITUDE SHORT-WAVE TROUGH WAS OVER SWRN WY...WITH STEEP
LAPSE RATES AND FAIRLY DEEP MOISTURE AHEAD OF IT PER THE 12Z KRIW
SOUNDING. AS THIS TROUGH DRIFTS SLOWLY NORTHEAST IT WILL SPREAD
ISOLD-SCT SHOWERS OVER NERN WY AND FAR SWRN SD THROUGH THE AFTN.
HOWEVER...A RELATIVELY DRY BOUNDARY LAYER OVER WRN SD WILL LIMIT
THE COVERAGE AND ERN EXTENT OF THE SHOWERS. OUR LOCAL WRF-ARW RUN
SUPPORTS THIS...BUT THE 12Z HRRR IS MUCH MORE AGGRESSIVE WITH
AFTN SHOWERS...WHICH IS INCONSISTENT WITH THE RELATIVELY DRY
BOUNDARY LAYER.
PREV DISCUSSION... /ISSUED 327 AM MDT FRI APR 13 2012/
DISCUSSION...
LONG WAVE RIDGE EXTENDS FROM MN TO LA WITH STRONG LONG WAVE TROF
NEAR THE WEST COAST. ONE STRONG SHORT WAVE EXTENDS FROM CNTRL MT
TO THE NE PANHANDLE WITH A SECOND STRONG SHORT WAVE MOVING INTO
THE LONG WAVE TROF ON THE WEST COAST THIS EVENING. WHILE THE FIRST
SHORT WAVE IS FCST TO MOVE QUICKLY NE WARD... THE SECOND MOVES TO
NV BY 12Z SAT AND THEN NE WARD WITH SIGNIFICANT IMPACT ON OUR CWFA.
AS THE SHORT WAVE APPROACHES...SFC CYCLOGENESIS IS FCST OVER CO.
THE LOW MOVES TO NORTH EAST NE BY 12Z SUN WITH A LARGE AREA OF
500MB Q VECTOR CONVERGENCE GIVING SUPPORT FOR PRECIP NORTH OF THE
LOW CENTER. UPPER SUPPORT FOR ASCENT AR IVES OVER OUR AREA BY 12Z
SAT WELL IN ADVANCE OF THE STRONG SHORT WAVE AND SFC CYCLOGENESIS. THE
700 MB LOW IS FCST TO MOVE NE WARD ACROSS THE SE PORTION OF OUR
CWA ON A TRACK THAT WOULD BE IDEAL FOR HEAVY SNOW IF TEMPS WERE A
BIT COLDER.
EARLIER CONVECTION THAT FORMED OVER WRN SD THIS AFTERNOON HAS
MOVED E WARD OUT OF THE CWFA. A WEAK AREA OF Q VECTOR CONVERGENCE
IS FCST TO MOVE QUICKLY OVER THE SRN PORTIONS OF THE CWFA THIS
MORNING GIVING A SLIGHT CHANCE FOR SHOWERS. MORE WIDESPREAD PRECIP
IS FCST TO DEVELOP OVER THE SRN PORTIONS OF OUR AREA WITH LARGE
SCALE ASCENT ON SATURDAY MORNING CONTINUING INTO SUNDAY. SOME
SNOW IS LIKELY OVER THE HIGHER ELEVATIONS OF THE BLACK HILLS.
MODELS ARE NOT IN GOOD AGREEMENT THIS MORNING AS TO HOW MUCH...WE
HAVE ABOUT 2 INCHES MAX IN PRESENT FCSTS. UNCERTAINTY ABOUT BOTH
PRECIP AMOUNTS AND TEMPS PREVENTS A FORECAST OF HIGHER
AMOUNTS AT THIS TIME...BUT THEY ARE POSSIBLE.
TEMPS PRETTY MUCH IN LINE WITH MAV AND MET GUIDANCE.
EXTENDED...A SERIES OF WEAK WAVES IN WESTERLY FLOW ALOFT WILL BRING
JUST A SLIGHT CHANCE OF SHOWERS TO VARIOUS PARTS OF THE AREA FROM
MONDAY THROUGH THURSDAY. EXTENDED MODELS DIFFER ON THE TIMING OF THE
WAVES SO WILL CONTINUE WITH A BLENDED SOLUTION FOR NOW. HIGH
TEMPERATURES WILL BE ONLY SLIGHTLY COOLER THAN NORMAL ON MONDAY...IN
THE UPPER 40S TO THE MID 50S ON THE PLAINS...WARMING INTO THE LOWER
60S TO LOWER 70S FOR WEDNESDAY AND THURSDAY.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...BUNKERS
LONG TERM....01
AVIATION...01
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
904 AM MDT FRI APR 13 2012
.UPDATE...A WEAK SHORT-WAVE RIDGE OVER THE CWA THIS MORNING HAS
ALLOWED FOR CLEARING SKIES AS A VIGOROUS SHORT-WAVE TROUGH WAS
JUST EAST OF THE CWA...TAKING PRECIPITATION WITH IT. A SLOW-MOVING
LOW-AMPLITUDE SHORT-WAVE TROUGH WAS OVER SWRN WY...WITH STEEP
LAPSE RATES AND FAIRLY DEEP MOISTURE AHEAD OF IT PER THE 12Z KRIW
SOUNDING. AS THIS TROUGH DRIFTS SLOWLY NORTHEAST IT WILL SPREAD
ISOLD-SCT SHOWERS OVER NERN WY AND FAR SWRN SD THROUGH THE AFTN.
HOWEVER...A RELATIVELY DRY BOUNDARY LAYER OVER WRN SD WILL LIMIT
THE COVERAGE AND ERN EXTENT OF THE SHOWERS. OUR LOCAL WRF-ARW RUN
SUPPORTS THIS...BUT THE 12Z HRRR IS MUCH MORE AGGRESSIVE WITH
AFTN SHOWERS...WHICH IS INCONSISTENT WITH THE RELATIVELY DRY
BOUNDARY LAYER.
&&
.PREV DISCUSSION... /ISSUED 327 AM MDT FRI APR 13 2012/
DISCUSSION...
LONG WAVE RIDGE EXTENDS FROM MN TO LA WITH STRONG LONG WAVE TROF
NEAR THE WEST COAST. ONE STRONG SHORT WAVE EXTENDS FROM CNTRL MT
TO THE NE PANHANDLE WITH A SECOND STRONG SHORT WAVE MOVING INTO
THE LONG WAVE TROF ON THE WEST COAST THIS EVENING. WHILE THE FIRST
SHORT WAVE IS FCST TO MOVE QUICKLY NE WARD... THE SECOND MOVES TO
NV BY 12Z SAT AND THEN NE WARD WITH SIGNIFICANT IMPACT ON OUR CWFA.
AS THE SHORT WAVE APPROACHES...SFC CYCLOGENESIS IS FCST OVER CO.
THE LOW MOVES TO NORTH EAST NE BY 12Z SUN WITH A LARGE AREA OF
500MB Q VECTOR CONVERGENCE GIVING SUPPORT FOR PRECIP NORTH OF THE
LOW CENTER. UPPER SUPPORT FOR ASCENT AR IVES OVER OUR AREA BY 12Z
SAT WELL IN ADVANCE OF THE STRONG SHORT WAVE AND SFC CYCLOGENESIS. THE
700 MB LOW IS FCST TO MOVE NE WARD ACROSS THE SE PORTION OF OUR
CWA ON A TRACK THAT WOULD BE IDEAL FOR HEAVY SNOW IF TEMPS WERE A
BIT COLDER.
EARLIER CONVECTION THAT FORMED OVER WRN SD THIS AFTERNOON HAS
MOVED E WARD OUT OF THE CWFA. A WEAK AREA OF Q VECTOR CONVERGENCE
IS FCST TO MOVE QUICKLY OVER THE SRN PORTIONS OF THE CWFA THIS
MORNING GIVING A SLIGHT CHANCE FOR SHOWERS. MORE WIDESPREAD PRECIP
IS FCST TO DEVELOP OVER THE SRN PORTIONS OF OUR AREA WITH LARGE
SCALE ASCENT ON SATURDAY MORNING CONTINUING INTO SUNDAY. SOME
SNOW IS LIKELY OVER THE HIGHER ELEVATIONS OF THE BLACK HILLS.
MODELS ARE NOT IN GOOD AGREEMENT THIS MORNING AS TO HOW MUCH...WE
HAVE ABOUT 2 INCHES MAX IN PRESENT FCSTS. UNCERTAINTY ABOUT BOTH
PRECIP AMOUNTS AND TEMPS PREVENTS A FORECAST OF HIGHER
AMOUNTS AT THIS TIME...BUT THEY ARE POSSIBLE.
TEMPS PRETTY MUCH IN LINE WITH MAV AND MET GUIDANCE.
EXTENDED...A SERIES OF WEAK WAVES IN WESTERLY FLOW ALOFT WILL BRING
JUST A SLIGHT CHANCE OF SHOWERS TO VARIOUS PARTS OF THE AREA FROM
MONDAY THROUGH THURSDAY. EXTENDED MODELS DIFFER ON THE TIMING OF THE
WAVES SO WILL CONTINUE WITH A BLENDED SOLUTION FOR NOW. HIGH
TEMPERATURES WILL BE ONLY SLIGHTLY COOLER THAN NORMAL ON MONDAY...IN
THE UPPER 40S TO THE MID 50S ON THE PLAINS...WARMING INTO THE LOWER
60S TO LOWER 70S FOR WEDNESDAY AND THURSDAY.
AVIATION...12Z TAF FORECAST
MVFR CIGS WILL BE FOUND OVER PARTS OF SOUTH CENTRAL SOUTH DAKOTA
THROUGH ABOUT 16Z...THEN VFR CONDITIONS WILL PREVAIL ACROSS THE
FORECAST AREA THROUGH THE REST OF TODAY AND TONIGHT. ISOLD TO SCT
RAIN SHOWERS ARE POSSIBLE TODAY AND TONIGHT. THE BETTER CHANCES OF
SHOWERS WILL BE OVER NORTHEASTERN WYOMING AND THE BLACK HILLS AREA
THIS AFTERNOON.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...BUNKERS
LONG TERM....01
AVIATION...01
AREA FORECAST DISCUSSION...UPDATED
NWS MIDLAND/ODESSA TX
915 PM CDT SAT APR 14 2012
.UPDATE...
RFW HAS EXPIRED.
&&
.DISCUSSION...
COLLISION OF PAC FRONT/DRYLINE IS OCCURRING IN GAINES/ANDREWS
ATTM. SATELLITE SHOWS COOLING TOPS OVER GAINES COUNTY AND
EXPECTING STORMD TO DEVELOP AS A RESULT OF COLLISION. RUC HAS
CAUGHT IN THIS IDEA A DEVELOPS AT LEAST A THIN LINE OF CONVECTION
BETWEEN 03Z AND 04Z...WOULD BE SURPRISED TO SEE IT SOONER. SEVERE
STORMS WILL BE POSSIBLE WITH STORMS THAT DEVELOP WITH BULK SHEAR
50-60KTS. EXPECT THAT LINE WOULD EVENTUALLY MOVE W AND WITH CELLS
MOVING NE ALONG THE LINE. LAPSE RATE AROUND 7.5 C/KM WILL FAVOR
LARGE HAIL.
TO THE W ACRS SE NM/WRN PB THE WINDS HAVE DECREASED SOME AND MOST
NPW HEADLINES WILL BE ALLOWED EXPIRE AT 03Z. ALTHOUGH THERE WILL
STILL BE A PROBLEM WITH THE DUST ESPECIALLY W THRU THE REMAINDER
OF THE EVENING WITH VISIBILITIES AROUND A MILE OR SO.
&&
.FIRE WEATHER...
RFW HAS SBEEN ALLOWED TO EXPIRE AS COOLER AIR IN WAKE OF THE
PACIFIC IS ALLOWING FOR RH TO INCREASE. STILL WINDY/VERY WINDY
NEXT FEW HRS ACRS THE W BUT FIRE WX CONCERNS HAVE DECREASED.
&&
.PRELIMINARY POINT TEMPS/POPS...
BIG SPRING TX 48 74 43 76 / 20 0 0 0
CARLSBAD NM 45 74 39 76 / 0 0 0 0
DRYDEN TX 55 82 50 83 / 20 0 0 0
FORT STOCKTON TX 47 76 45 79 / 10 0 0 0
GUADALUPE PASS TX 40 64 43 70 / 0 0 0 0
HOBBS NM 41 70 42 76 / 10 0 0 0
MARFA TX 37 69 29 69 / 10 0 0 0
MIDLAND INTL AIRPORT TX 47 73 44 78 / 20 0 0 0
ODESSA TX 49 73 45 78 / 20 0 0 0
WINK TX 45 75 43 82 / 10 0 0 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...BLOWING DUST ADVISORY UNTIL 9 PM MDT THIS EVENING FOR THE
FOLLOWING ZONES... CENTRAL LEA COUNTY...EDDY COUNTY
PLAINS...GUADALUPE MOUNTAINS OF EDDY COUNTY...NORTHERN LEA
COUNTY...SOUTHERN LEA COUNTY.
HIGH WIND WARNING UNTIL NOON MDT SUNDAY FOR THE FOLLOWING
ZONES... GUADALUPE MOUNTAINS OF EDDY COUNTY.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING
FOR THE FOLLOWING ZONES... GUADALUPE MOUNTAINS NP/LINCOLN
NF/LNZ...SOUTHEAST PLAINS/BLM ROSWELL/LNZ.
WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR THE FOLLOWING
ZONES... CENTRAL LEA COUNTY...NORTHERN LEA COUNTY...
SOUTHERN LEA COUNTY.
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR THE FOLLOWING
ZONES... EDDY COUNTY PLAINS.
TX...BLOWING DUST ADVISORY UNTIL 10 PM CDT /9 PM MDT/ THIS EVENING
FOR THE FOLLOWING ZONES... GUADALUPE MOUNTAINS...REEVES
COUNTY AND UPPER TRANS PECOS...VAN HORN AND HIGHWAY 54
CORRIDOR.
HIGH WIND WARNING UNTIL NOON MDT SUNDAY FOR THE FOLLOWING
ZONES... GUADALUPE MOUNTAINS.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING
FOR THE FOLLOWING ZONES... DAVIS/APACHE MOUNTAINS AREA...
GUADALUPE MOUNTAINS...REEVES COUNTY AND UPPER TRANS PECOS...
VAN HORN AND HIGHWAY 54 CORRIDOR.
WIND ADVISORY UNTIL 7 AM CDT SUNDAY FOR THE FOLLOWING ZONES...
DAVIS/APACHE MOUNTAINS AREA.
WIND ADVISORY UNTIL 10 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES... ANDREWS...GAINES...LOVING...MARFA PLATEAU...REEVES
COUNTY AND UPPER TRANS PECOS...WARD...WINKLER.
HIGH WIND WARNING UNTIL 10 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES... VAN HORN AND HIGHWAY 54 CORRIDOR.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1239 PM CDT FRI APR 13 2012
.AVIATION...
A COUPLE ITEMS WORTH MENTIONING THIS ISSUANCE. THIS AFTERNOON TSTM
CHANCES /SOME SEVERE/ WILL BE POSSIBLE UP NEAR KCDS ALONG AND EAST
OF DRYLINE. THIS DRYLINE IS EXPECTED TO RETREAT THIS EVENING AND
WE COULD SEE STORMS CONTINUING ALONG IT WELL INTO THE EVENING
HOURS THOUGH UNCERTAINTY IN THIS SCENARIO IS A BIT HIGHER THAN WE
WOULD LIKE TO CONTINUE MENTION IN THE TAF ALL EVENING. BREEZY
SOUTHWESTERLY WINDS AT KLBB SHOULD NOT BE MUCH OF AN IMPACT AT
KLBB DESPITE ABSENCE OF RWY 26 FROM THEIR PORTFOLIO. ON
SATURDAY...LATE MORNING ONWARD...WINDY CONDITIONS EXPECTED ALONG
WITH BLDU POTENTIAL AT KLBB.
&&
.PREV DISCUSSION... /ISSUED 1131 AM CDT FRI APR 13 2012/
UPDATE...
DRYLINE HAS ACCELERATED ITS EASTWARD MOTION MAINLY ACROSS THE
SOUTHERN ZONES THIS MORNING THOUGH THE BEHAVIOR ON THE NORTHERN
EXTENT REMAINS MORE COMPLEX. MODEL GUIDANCE DEPICTS SCENARIO
WHEREBY THE DRYLINE MAY REMAIN HINGED IN THE EASTERN TEXAS
PANHANDLE WITH THE DRYLINE ACROSS THE SOUTHERN ZONES SWINGING
EASTWARD YIELDING A MORE N/S ORIENTATION TO THE DRYLINE...AND THUS
MORE NORMAL TO THE UPPER LEVEL FLOW. WHILE THE THREAT LOOKS TO
REMAIN ACROSS THE FAR EASTERN ZONES...THERE REMAINS A FAIR BIT OF
UNCERTAINTY TO THE EASTERN PROGRESSION OF THE DRYLINE. LATEST
SURFACE AND RUC ANALYSIS SHOWS POSITIVE ENERGY ALREADY UP IN THE
3KJ/KG VICINITY AND CU FIELD CONTINUES TO INCREASE IN
INVIGORATION. THUS...HAVE UPPED POPS OUT EAST THIS AFTERNOON WITH
MENTION OF SVR. WHILE SHEAR REMAINS QUITE ANEMIC...INSTABILTY
COULD CERTAINLY SUPPORT PULSE SEVERE ACTIVITY WITH THE ATTENDANT
HAIL/WIND THREAT. FOR SEVERAL DAYS...GUIDANCE HAS INDICATED A
FAIRLY PRONOUNCED DRYLINE RETREAT THIS EVENING WITH THE POTENTIAL
FOR STORM DEVELOPMENT THIS EVENING AND OVERNIGHT. WATER VAPOR
IMAGERY SUGGEST THAT THERE WILL BE PERIOD OF SUBTLE LIFT TONIGHT
BUT WILL ADDRESS THAT IN THIS AFTERNOONS PACKAGE.
AFTER COORDINATION WITH TFS...WILL LIKELY GO AHEAD AND ISSUE FIRE
WEATHER WATCH OUT WEST FOR SATURDAY AS THE FUELS LOOK SUFFICIENTLY
DRY GIVEN TOMORROW WIND AND RH SPEEDS TO SATISFY CRITICAL FIRE WEATHER.
PREV DISCUSSION... /ISSUED 640 AM CDT FRI APR 13 2012/
AVIATION...
RETREATING DRYLINE HAS STALLED JUST NORTHWEST OF THE TERMINALS
THIS MORNING AND HAS SUPPORTED LIGHT FOG AND SCT-BKN MVFR CLOUD
DEVELOPMENT FROM GNC NORTHEAST TO LBB AND CDS. DRIER AIR IS NUDGING
EAST NEAR LBB AND THIS WILL RID MVFR CONDITIONS SHORTLY WITH VFR
LEVELS RETURNING TO CDS AROUND 14Z.
DRYLINE WILL MIX TO BETWEEN LBB AND CDS BY MIDDAY AT WHICH POINT
ISOLATED TSRA SHOULD DEVELOP. A FEW OF THE MOST RECENT MODELS ARE
MORE AGGRESSIVE WITH A DRYLINE BULGE NEAR CDS BY 00Z AND THIS
WOULD FAVOR HIGHER TSRA PROBS...BUT WILL LEAVE THIS OPTION TO
LATER TAFS AS THIS THREAT IS STILL 12 HOURS OUT. RATHER STRONG
WIND SHEAR AND AMPLE INSTABILITY COULD EASILY GARNER +TSRAGR
ANYWHERE IN THE VICINITY OF CDS UNTIL CONVECTION SHIFTS NORTH-
NORTHEAST AFTER SUNSET. COULD ALSO SEE MVFR CIGS MAKE A RETURN
LATE IN THIS TAF CYCLE AT BOTH CDS AND LBB AS THE DRYLINE
RETREATS.
PREV DISCUSSION... /ISSUED 412 AM CDT FRI APR 13 2012/
SHORT TERM...
SHORTWAVE TROUGH LIFTING NORTHEAST ACROSS THE CENTRAL HIGH PLAINS
AT 08Z WAS FOUND DRIVING A DIFFUSE COLD FRONT EASTWARD ACROSS THE
TX PANHANDLE AND NWRN SOUTH PLAINS WEST OF A STALLING DRYLINE.
THIS WEAK FRONT WILL RETREAT NORTH BY MIDDAY AS LEE CYCLOGENESIS
ORGANIZES IN SERN COLORADO. ASSOCIATED TROUGHING SOUTH OF THIS LOW
INTO ERN NM WILL TEND TO BACK 850-700MB WINDS FAVORING A LATE AFTN
DRYLINE POSITION ALONG OR JUST EAST OF THE CAPROCK ESCARPMENT.
CONVERGENCE HOWEVER ALONG THE DRYLINE WILL BE HINDERED SOMEWHAT BY
THIS SUBTLE BACKING OF WINDS ALOFT...THEREFORE SOME DOUBT IS CAST
REGARDING TSTRM INITIATION. AVAILABLE FORCING OUTSIDE OF THE
DRYLINE IS MINIMAL. ONE IMPULSE ALOFT IS EVIDENT ON WATER VAPOR
IMAGERY ACROSS SRN NM THIS MORNING...HOWEVER THIS WILL PASS BEFORE
MIDDAY LEAVING THE SOUTH PLAINS TO CONTEND WITH WEAK SUBSIDENCE
ALOFT. IN SPITE OF THESE NEGATIVE FACTORS THE EML IS NOT PROGGED
TO INTENSIFY AND LL MOISTURE WILL BE DEEPER THAN YESTERDAY. GFS
AGAIN APPEARS OVERDONE WITH PRECIP COVERAGE WITH MORE CREDIBILITY
OFFERED BY THE NAM. INTERESTINGLY...THE TTU WRF HAS PERFORMED
ADMIRABLY IN RECENT DAYS REGARDING CI AND THE 00Z SOLUTION IS
CREDIBLE WITH ISO-WIDELY SCTD SMALL SHRA/TSTRMS GIVEN OVERALL WEAK
BACKGROUND FORCING. HAVE THEREFORE INTRODUCED ISO TSTRMS OFF THE
CAPROCK AFTER 20Z. DESPITE ENHANCED HAIL PROBS PER SWODY1...SEVERE
THREAT REMAINS ISOLATED AND CONDITIONAL ENOUGH TO OMIT MENTION
FROM THE GRIDS.
STRENGTHENING WAA ALONG THE NOSE OF A NOCTURNAL LLJ WILL ACT TO
FOCUS POP CHANCES FARTHER N-NE TONIGHT...PERHAPS GRAZING OUR NERN
COUNTIES AFTER MIDNIGHT. EARLIER WOES WITH THE GFS EXTEND INTO THE
OVERNIGHT WITH LITTLE/NO CREDIBILITY GIVEN TO ITS ROBUST DRYLINE
CONVERGENCE ACROSS THE SWRN SOUTH PLAINS AND SUBSEQUENT CONVECTIVE
SIGNALS LINGERING THROUGH SAT MORNING.
LONG TERM...
SATURDAY IS CONTINUING TO SHAPE UP AS A DEFINITE BREEZY AND
POSSIBLY EVEN WINDY DAY ACROSS THE REGION AS THE UPPER LEVEL LOW
APPROACHES THE FOUR CORNERS REGION AND A TIGHT PRESSURE GRADIENT
DEVELOPS AT THE SURFACE. BOTH THE NAM AND GFS MOS GUIDANCE ARE NOW
PUSHING SUSTAINED WIND SPEEDS SATURDAY AFTERNOON INTO THE 35 TO 45
MPH RANGE ON THE CAPROCK. ALTHOUGH THERE HAS BEEN SOME RECENT
RAINFALL...EXPECT THESE KIND OF WIND SPEEDS TO STIR UP SOME
BLOWING DUST. ALTHOUGH WIND SPEEDS WILL DEFINITELY BE FAIRLY
STRONG TOMORROW...FEEL THAT THEY MAY NOT BE QUITE AS HIGH AS
GUIDANCE VALUES ARE INDICATING BUT DID INCREASE WIND SPEEDS IN THE
GRIDS BY ABOUT 3-5 KTS OVER THE NAM SURFACE WIND SPEEDS.
ANOTHER ISSUE WILL BE HOW FAR WEST THE DRYLINE WILL MIX. MODELS
CURRENTLY STALL OUT THE DRYLINE OVER THE EASTERN ROLLING PLAINS
WHICH WILL MEAN THAT MUCH OF THE AREA WILL NOT SEE PRECIPITATION.
IF WIND SPEEDS TO INCREASE INTO THE 40 TO 50 MPH...DRYLINE MAY
ALSO PUSH A BIT FURTHER EAST THAN THE MODELS ARE INDICATING.
SHOULD STORMS DEVELOP IN THE VICINITY OF THE DRYLINE LATE SATURDAY
AFTERNOON...THEY SHOULD RAPIDLY MOVE OFF TO THE NORTHEAST SO
COVERAGE AND INTENSITY OF STORMS SHOULD BE FAIRLY LIMITED.
THE CLOSED LOW WILL OPEN UP INTO A POSITIVELY TILTED WAVE DURING
THE DAY SUNDAY AND CONTINUE TO PUSH TOWARDS THE CENTRAL PLAINS.
THE HEIGHT GRADIENT ALOFT REMAINS SOMEWHAT TIGHT BUT NOT AS STRONG
AS ON SATURDAY SO WIND SPEEDS WILL STILL RAMP UP A BIT...
ESPECIALLY IN THE AFTERNOON WITH DAYTIME MIXING TAKING PLACE. A
WEAK COLD FRONT WILL THEN PUSH INTO THE AREA DURING THE OVERNIGHT
HOURS SUNDAY INTO MONDAY WITH MUCH LIGHTER WIND SPEEDS AND
TEMPERATURES A BIT COOLER ON BOTH SUNDAY AND MONDAY. MODELS THEN
DEVELOP WEAK NORTHWESTERLY TO ZONAL FLOW THROUGH MUCH OF NEXT WEEK
WHICH WILL FAVOR TEMPERATURES NEAR NORMAL AND A DIFFUSE SLOSHING
DRYLINE SETUP AS WELL. A DRY FORECAST ALSO LOOKS TO BE IN STORE AS
LITTLE IN THE WAY OF DISTURBANCES WILL MOVE OVER THE REGION AND A
LACK OF SURFACE CONVERGENCE ALONG THE DRYLINE WILL KEEP CONVECTION
FROM DEVELOPING.
JORDAN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 79 48 76 38 62 / 0 0 0 10 10
TULIA 83 55 78 39 67 / 0 10 10 10 10
PLAINVIEW 83 56 81 40 67 / 0 10 0 10 10
LEVELLAND 83 53 80 42 67 / 10 10 0 10 10
LUBBOCK 85 57 81 42 69 / 10 10 0 10 10
DENVER CITY 83 51 80 44 68 / 10 10 0 10 10
BROWNFIELD 85 55 82 45 68 / 10 10 0 10 10
CHILDRESS 85 63 84 52 75 / 20 20 10 20 10
SPUR 86 63 86 50 74 / 20 20 10 20 10
ASPERMONT 85 63 88 56 76 / 20 20 10 20 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26/99/99
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1131 AM CDT FRI APR 13 2012
.UPDATE...
DRYLINE HAS ACCELERATED ITS EASTWARD MOTION MAINLY ACROSS THE
SOUTHERN ZONES THIS MORNING THOUGH THE BEHAVIOR ON THE NORTHERN
EXTENT REMAINS MORE COMPLEX. MODEL GUIDANCE DEPICTS SCENARIO
WHEREBY THE DRYLINE MAY REMAIN HINGED IN THE EASTERN TEXAS
PANHANDLE WITH THE DRYLINE ACROSS THE SOUTHERN ZONES SWINGING
EASTWARD YIELDING A MORE N/S ORIENTATION TO THE DRYLINE...AND THUS
MORE NORMAL TO THE UPPER LEVEL FLOW. WHILE THE THREAT LOOKS TO
REMAIN ACROSS THE FAR EASTERN ZONES...THERE REMAINS A FAIR BIT OF
UNCERTAINTY TO THE EASTERN PROGRESSION OF THE DRYLINE. LATEST
SURFACE AND RUC ANALYSIS SHOWS POSITIVE ENERGY ALREADY UP IN THE
3KJ/KG VICINITY AND CU FIELD CONTINUES TO INCREASE IN
INVIGORATION. THUS...HAVE UPPED POPS OUT EAST THIS AFTERNOON WITH
MENTION OF SVR. WHILE SHEAR REMAINS QUITE ANEMIC...INSTABILTY
COULD CERTAINLY SUPPORT PULSE SEVERE ACTIVITY WITH THE ATTENDANT
HAIL/WIND THREAT. FOR SEVERAL DAYS...GUIDANCE HAS INDICATED A
FAIRLY PRONOUNCED DRYLINE RETREAT THIS EVENING WITH THE POTENTIAL
FOR STORM DEVELOPMENT THIS EVENING AND OVERNIGHT. WATER VAPOR
IMAGERY SUGGEST THAT THERE WILL BE PERIOD OF SUBTLE LIFT TONIGHT
BUT WILL ADDRESS THAT IN THIS AFTERNOONS PACKAGE.
AFTER COORDINATION WITH TFS...WILL LIKELY GO AHEAD AND ISSUE FIRE
WEATHER WATCH OUT WEST FOR SATURDAY AS THE FUELS LOOK SUFFICIENTLY
DRY GIVEN TOMORROW WIND AND RH SPEEDS TO SATISFY CRITICAL FIRE WEATHER.
&&
.PREV DISCUSSION... /ISSUED 640 AM CDT FRI APR 13 2012/
AVIATION...
RETREATING DRYLINE HAS STALLED JUST NORTHWEST OF THE TERMINALS
THIS MORNING AND HAS SUPPORTED LIGHT FOG AND SCT-BKN MVFR CLOUD
DEVELOPMENT FROM GNC NORTHEAST TO LBB AND CDS. DRIER AIR IS NUDGING
EAST NEAR LBB AND THIS WILL RID MVFR CONDITIONS SHORTLY WITH VFR
LEVELS RETURNING TO CDS AROUND 14Z.
DRYLINE WILL MIX TO BETWEEN LBB AND CDS BY MIDDAY AT WHICH POINT
ISOLATED TSRA SHOULD DEVELOP. A FEW OF THE MOST RECENT MODELS ARE
MORE AGGRESSIVE WITH A DRYLINE BULGE NEAR CDS BY 00Z AND THIS
WOULD FAVOR HIGHER TSRA PROBS...BUT WILL LEAVE THIS OPTION TO
LATER TAFS AS THIS THREAT IS STILL 12 HOURS OUT. RATHER STRONG
WIND SHEAR AND AMPLE INSTABILITY COULD EASILY GARNER +TSRAGR
ANYWHERE IN THE VICINITY OF CDS UNTIL CONVECTION SHIFTS NORTH-
NORTHEAST AFTER SUNSET. COULD ALSO SEE MVFR CIGS MAKE A RETURN
LATE IN THIS TAF CYCLE AT BOTH CDS AND LBB AS THE DRYLINE
RETREATS.
PREV DISCUSSION... /ISSUED 412 AM CDT FRI APR 13 2012/
SHORT TERM...
SHORTWAVE TROUGH LIFTING NORTHEAST ACROSS THE CENTRAL HIGH PLAINS
AT 08Z WAS FOUND DRIVING A DIFFUSE COLD FRONT EASTWARD ACROSS THE
TX PANHANDLE AND NWRN SOUTH PLAINS WEST OF A STALLING DRYLINE.
THIS WEAK FRONT WILL RETREAT NORTH BY MIDDAY AS LEE CYCLOGENESIS
ORGANIZES IN SERN COLORADO. ASSOCIATED TROUGHING SOUTH OF THIS LOW
INTO ERN NM WILL TEND TO BACK 850-700MB WINDS FAVORING A LATE AFTN
DRYLINE POSITION ALONG OR JUST EAST OF THE CAPROCK ESCARPMENT.
CONVERGENCE HOWEVER ALONG THE DRYLINE WILL BE HINDERED SOMEWHAT BY
THIS SUBTLE BACKING OF WINDS ALOFT...THEREFORE SOME DOUBT IS CAST
REGARDING TSTRM INITIATION. AVAILABLE FORCING OUTSIDE OF THE
DRYLINE IS MINIMAL. ONE IMPULSE ALOFT IS EVIDENT ON WATER VAPOR
IMAGERY ACROSS SRN NM THIS MORNING...HOWEVER THIS WILL PASS BEFORE
MIDDAY LEAVING THE SOUTH PLAINS TO CONTEND WITH WEAK SUBSIDENCE
ALOFT. IN SPITE OF THESE NEGATIVE FACTORS THE EML IS NOT PROGGED
TO INTENSIFY AND LL MOISTURE WILL BE DEEPER THAN YESTERDAY. GFS
AGAIN APPEARS OVERDONE WITH PRECIP COVERAGE WITH MORE CREDIBILITY
OFFERED BY THE NAM. INTERESTINGLY...THE TTU WRF HAS PERFORMED
ADMIRABLY IN RECENT DAYS REGARDING CI AND THE 00Z SOLUTION IS
CREDIBLE WITH ISO-WIDELY SCTD SMALL SHRA/TSTRMS GIVEN OVERALL WEAK
BACKGROUND FORCING. HAVE THEREFORE INTRODUCED ISO TSTRMS OFF THE
CAPROCK AFTER 20Z. DESPITE ENHANCED HAIL PROBS PER SWODY1...SEVERE
THREAT REMAINS ISOLATED AND CONDITIONAL ENOUGH TO OMIT MENTION
FROM THE GRIDS.
STRENGTHENING WAA ALONG THE NOSE OF A NOCTURNAL LLJ WILL ACT TO
FOCUS POP CHANCES FARTHER N-NE TONIGHT...PERHAPS GRAZING OUR NERN
COUNTIES AFTER MIDNIGHT. EARLIER WOES WITH THE GFS EXTEND INTO THE
OVERNIGHT WITH LITTLE/NO CREDIBILITY GIVEN TO ITS ROBUST DRYLINE
CONVERGENCE ACROSS THE SWRN SOUTH PLAINS AND SUBSEQUENT CONVECTIVE
SIGNALS LINGERING THROUGH SAT MORNING.
LONG TERM...
SATURDAY IS CONTINUING TO SHAPE UP AS A DEFINITE BREEZY AND
POSSIBLY EVEN WINDY DAY ACROSS THE REGION AS THE UPPER LEVEL LOW
APPROACHES THE FOUR CORNERS REGION AND A TIGHT PRESSURE GRADIENT
DEVELOPS AT THE SURFACE. BOTH THE NAM AND GFS MOS GUIDANCE ARE NOW
PUSHING SUSTAINED WIND SPEEDS SATURDAY AFTERNOON INTO THE 35 TO 45
MPH RANGE ON THE CAPROCK. ALTHOUGH THERE HAS BEEN SOME RECENT
RAINFALL...EXPECT THESE KIND OF WIND SPEEDS TO STIR UP SOME
BLOWING DUST. ALTHOUGH WIND SPEEDS WILL DEFINITELY BE FAIRLY
STRONG TOMORROW...FEEL THAT THEY MAY NOT BE QUITE AS HIGH AS
GUIDANCE VALUES ARE INDICATING BUT DID INCREASE WIND SPEEDS IN THE
GRIDS BY ABOUT 3-5 KTS OVER THE NAM SURFACE WIND SPEEDS.
ANOTHER ISSUE WILL BE HOW FAR WEST THE DRYLINE WILL MIX. MODELS
CURRENTLY STALL OUT THE DRYLINE OVER THE EASTERN ROLLING PLAINS
WHICH WILL MEAN THAT MUCH OF THE AREA WILL NOT SEE PRECIPITATION.
IF WIND SPEEDS TO INCREASE INTO THE 40 TO 50 MPH...DRYLINE MAY
ALSO PUSH A BIT FURTHER EAST THAN THE MODELS ARE INDICATING.
SHOULD STORMS DEVELOP IN THE VICINITY OF THE DRYLINE LATE SATURDAY
AFTERNOON...THEY SHOULD RAPIDLY MOVE OFF TO THE NORTHEAST SO
COVERAGE AND INTENSITY OF STORMS SHOULD BE FAIRLY LIMITED.
THE CLOSED LOW WILL OPEN UP INTO A POSITIVELY TILTED WAVE DURING
THE DAY SUNDAY AND CONTINUE TO PUSH TOWARDS THE CENTRAL PLAINS.
THE HEIGHT GRADIENT ALOFT REMAINS SOMEWHAT TIGHT BUT NOT AS STRONG
AS ON SATURDAY SO WIND SPEEDS WILL STILL RAMP UP A BIT...
ESPECIALLY IN THE AFTERNOON WITH DAYTIME MIXING TAKING PLACE. A
WEAK COLD FRONT WILL THEN PUSH INTO THE AREA DURING THE OVERNIGHT
HOURS SUNDAY INTO MONDAY WITH MUCH LIGHTER WIND SPEEDS AND
TEMPERATURES A BIT COOLER ON BOTH SUNDAY AND MONDAY. MODELS THEN
DEVELOP WEAK NORTHWESTERLY TO ZONAL FLOW THROUGH MUCH OF NEXT WEEK
WHICH WILL FAVOR TEMPERATURES NEAR NORMAL AND A DIFFUSE SLOSHING
DRYLINE SETUP AS WELL. A DRY FORECAST ALSO LOOKS TO BE IN STORE AS
LITTLE IN THE WAY OF DISTURBANCES WILL MOVE OVER THE REGION AND A
LACK OF SURFACE CONVERGENCE ALONG THE DRYLINE WILL KEEP CONVECTION
FROM DEVELOPING.
JORDAN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 79 48 76 38 62 / 0 0 0 10 10
TULIA 83 55 78 39 67 / 0 10 10 10 10
PLAINVIEW 83 56 81 40 67 / 0 10 0 10 10
LEVELLAND 83 53 80 42 67 / 10 10 0 10 10
LUBBOCK 85 57 81 42 69 / 10 10 0 10 10
DENVER CITY 83 51 80 44 68 / 10 10 0 10 10
BROWNFIELD 85 55 82 45 68 / 10 10 0 10 10
CHILDRESS 85 63 84 52 75 / 20 20 10 20 10
SPUR 86 63 86 50 74 / 20 20 10 20 10
ASPERMONT 85 63 88 56 76 / 20 20 10 20 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26/99
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1026 PM CDT SAT APR 14 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...ALL EYES OBVIOUSLY ON POTENTIAL FOR SVR WX OUTBREAK
TOMORROW.
FIRST FOR TNGT...GIST OF GOING FCST OKAY. INSTABILITY PERHAPS A
LITTLE SLOWER TO BUILD NWD. DLAD THE ONSET OF PCPN...AND HELD
THUNDER BACK FM LEADING EDGE OF PCPN IN THE GRIDS. MAY END UP WITH
JUST RAIN UNTIL WE GET TOWARD THE BACK EDGE OF THE PCPN
SHIELD...BUT THAT WAS A LITTLE BIGGER FCST CHG THAN COMFORTABLE
MAKING AT THIS POINT. MUCAPES OFF THE 18Z NAM AND 21Z RUC SEEMED
RATHER LOW FOR GETTING MUCH HAIL OVERNIGHT...BUT SINCE WE ONLY HAD
SML HAIL MENTIONED...WL LET IT RIDE.
SITN FOR TOMORROW WAS DESCRIBED AS MUDDLED BY THE DAY SHIFT...AND
THAT/S STILL FITTING. NEED TO MAKE SOME GUESSES ABOUT HOW
CONVECTION WL EVOLVE OVERNIGHT AND EARLY SUN IN ORDER TO LAY OUT
SCENARIO FOR TOMORROW AFTN/EVENING. OF COURSE FCST CAN EASILY JUMP
THE TRACKS IF ANY OF THE SUPPOSITIONS ARE WRONG...BUT HERE GOES
ANYWAY. IT NOW LOOKS LIKE REMNANTS OF MCS OR AT LEAST CLUSTERS OF
STORMS WL STILL BE ONGOING INTO AT LEAST PART OF THE MORNING. THAT
COMBINED WITH SFC LOW STILL OUT IN THE CENTRAL PLAINS AND FCST
AREA STILL RELATIVELY NEAR UPR RIDGE POSN FAVOR A SLOWER NWD MVMT
OF THE WARM FRONT. AND EVEN ONCE FRONT STARTS TO WORK NWD ACRS THE
AREA...THERE WL BE WATER TO EVAPORATE OFF WET SFCS AND LOW CLDS
AND PROBABLY SOME FG TO CHEW THROUGH. MODELS ALL ALSO SUGGESTED
CONSIDERABLE MIDDLE LEVEL MOISTURE LINGERING OVER THE AREA...SO WE
MAY BE HARD PRESSED TO GET MUCH SUNSHINE. WE PROBABLY WL GET A NWD
SURGE IN THE FRONT LATER IN THE DAY AS UPR FLOW BACKS MORE SWLY
AND STRENGTHENS WITH THE APPROACH OF THE UPR TROF...BUT AT THIS
POINT NOT SURE WE/LL EVER BE ABLE TO DRIVE THE WARM FRONT ALL THE
WAY THROUGH THE FCST AREA. SO WHILE WARM FRONT PROBABLY SLOWS OVER
FAR NRN WI...COLD FRONT WL ENTER THE WRN PART OF THE FCST AREA
ARND SUNSET...AND RACE EWD DURING THE EVENING. THE FLOW MAY BE
GETTING MORE UNI-DIRECTIONAL BY THEN...BUT VERY STG WINDS ALOFT
WOULD SUPPORT DAMAGING WIND THREAT...ESP IF CONVECTION CAN
ORGANIZE INTO A MORE SOLID LINE ALONG THE FRONT.
TWEAKED GRIDS WITH CHGS DESCRIBED ABV. WL HAVE UPDATED ZONES OUT
SHORTLY...AND THEN FRESHEN THE WORDING IN THE HWO.
SKOWRONSKI
&&
.PREV DISCUSSION...ISSUED AT 604 PM CDT SAT APR 14 2012...
SHORT TERM...TONIGHT THROUGH SUNDAY...
FOCUS OF THIS FORECAST ON THUNDERSTORM POTENTIAL TONIGHT AND
SUNDAY AND MODERATE RISK FOR SEVERE WEATHER ON SUNDAY.
DEEP UPPER LOW TO LIFT OUT OF THE SOUTHWEST TODAY INTO THE
CENTRAL PLAINS SUN MORN...MOVING INTO SUN EVENING. ASSOCIATED
SURFACE LOW NOW OVER NE KANSAS AND ASSOCIATED WARM FRONT TO MOVE
NORTH...WITH WARM FRONT MOVING THROUGH WI TONIGHT...LIKELY
STALLING OVER NORTHERN WI...THOUGH SOME DIFFERENCE IN MODELS HERE.
EXPECT AREA OF SHOWERS AND STORMS TO LIFT NORTH TONIGHT...MAINLY
AFTER MIDNIGHT. GIVEN SOME SHEER AND LOW WET BULB ZEROS THOUGHTS
GO TOWARD SMALL/NEAR SEVERE HAIL THREAT. INSTABILITY DOES NOT NOT
LOOK OVERLY IMPRESSIVE FOR LARGER HAIL.
SUNDAY IS MORE MUDDLED...EVEN THOUGH MUCH OF AREA NOW UNDER
MODERATE RISK FOR SEVERE THUNDERSTORMS. QUESTIONS INCLUDE ONGOING
SHOWER ACTIVITY AND POTENTIAL FOR CLEARING. MODELS TREND AT
KEEPING CLOUDS OVER CWA. TIMING OF FRONT MOVING THROUGH THE CWA IS
EVENING...WHICH NEVER BODES WELL FOR CLEAR SHOT FOR
SEVERE...ESPECIALLY THIS TIME OF YEAR. MODEL PARAMETERS HIGH AND
DO POINT AT POSSIBLE TORNADOES WITH SIG SHEAR...CAPE...ETC.
THOUGH WITH 5H WINDS AT 70+ KTS SUN AFTN QUESTION IS WHETHER
INSTABILITY WL BE SUFFICIENT GIVEN VERY STG SHEAR. HAVE
HIGHLIGHTED DAMAGING WINDS AS THE MAIN THREAT FOR TOMORROW.
LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. THE SUNDAY NIGHT
INTO MONDAY PERIOD WILL BE DEALING WITH THE AFFECTS OF A DEEP LOW
PRESSURE SYSTEM TRACKING OVER NORTHWEST WISCONSIN. INITIALLY
POSSIBLE STRONG TO SEVERE STORMS MAY STILL BE ONGOING OVER THE
AREA IN THE STRONG SHEARED AND POTENTIALLY UNSTABLE ATMOSPHERE
THROUGH SUNDAY EVENING. TO HIGHLIGHT CONDITIONS FOR LATER
SUNDAY...FOR STARTER...BUFKIT SOUNDINGS SHOW A 50 TO 60 KT WINDS
AT 00Z SUNDAY WITH THE NAM CONSIDERABLY MORE UNSTABLE THAN THE GFS
WITH CAPES OF AROUND 1000 J/KG. HELICITY VALUES ALONG WITH SWEAT
INDEX VALUES ARE VERY HIGH TO SUGGEST A POTENTIAL OF TORNADOES.
LOW WET BULBS COULD ALSO SUPPORT LARGE HAIL. LATER IN THE EVENING
AS THE SURFACE TROUGH WORKS IN...PRIMARY THREAT MAY TURN TO
DAMAGING WINDS ALONG A SQUALL LINE. TIMING OF THIS TROUGH PROVIDES
SOME CHALLENGE ON THE DURATION OF THIS LIKELY SEVERE WEATHER
EVENT...BUT ANTICIPATE THE END LATER EVENING OVER NORTHEAST AND
EASTERN WISCONSIN.
STRONG CAA PATTERN ON THE BACKSIDE OF THE DEEP LOW THEN POURS
INTO THE STATE ON MONDAY WITH A POSSIBLE MIX FAR NORTH BEFORE THE
SYSTEM PULLS OUT.
WEAK SURFACE RIDGE PASSES THE REGION TUESDAY FOLLOWED BY THE NEXT
SYSTEM TRACKING FROM THE NORTHERN PLAINS TO THE GREAT LAKES REGION
AROUND WEDNESDAY. ANOTHER SYSTEM TRACKS OVER LATER IN THE WEEK AND
APPEARS TO BE TRENDING SOUTH OF THE AREA BUT PERHAPS BRUSHING
CENTRAL WISCONSIN WITH LITE PCPN.
&&
.AVIATION...MAIN CHG FOR THE 06Z ISSUANCE WL BE TO DELAY THE ONSET
OF MVFR CIGS OVERNIGHT. THIS GOES ALONG WITH PCPN TAKING LONGER TO
REACH THE AREA. ALSO KEPT PCPN GOING A LITTLE LONGER SUN...ESP
OVER THE N.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
914 PM CDT SAT APR 14 2012
.UPDATE...
MAIN SHORT TERM PROBLEM IS BOW ECHO MOVING ACROSS SOUTH CENTRAL
IOWA. NORTHERN BOOKEND VORTEX WAS PUSHING MORE NORTHEAST WHILE THE
STRONGEST STORMS ARE HEADING MAINLY EAST. THE LOCAL 21Z 4 KM WRF
MODEL DID A VERY GOOD JOB PICKING UP THIS FEATURE. IT RACES IT
EAST AND WEAKENS IT AS IT REACHES JUST SOUTH OF ROCKFORD IL AROUND
2 AM. THIS MODEL ALSO BACKS THE SURFACE WINDS TO SOUTHEAST AS THE
MAIN SURFACE WARM FRONT REACHES THE ILLINOIS BORDER BY 5 AM AND TO
MADISON AND MILWAUKEE AROUND OR JUST AFTER 7 AM. THE 23Z HRRR DOES
NOT PICK UP THE BOW ECHO BUT DOES PUSH THE WARM FRONT TOWARD THE
ILLINOIS BORDER AROUND THE SAME TIME. HOWEVER WIDESPREAD SHOWERS
AND THUNDERSTORMS JUST NORTH OF THE WARM FRONT KEEP THE FRONT
JUST SOUTH OF THE ILLINOIS BORDER THROUGH 12Z.
RUC SOUNDINGS KEEP ELEVATED CAPE LIFTED FROM AROUND 7 THSD FT TO
AROUND 400 J/KG. APPEARS MAINLY SMALL HAIL...ALTHOUGH MARGINAL
SEVERE HAIL WILL BE POSSIBLE SOUTHWEST OF MADISON PER THE SPC
DAY 1 OUTLOOK.
00Z NAM PUSH THE 850 MB LOW LEVEL JET INTO SOUTHERN WISCONSIN BY
18Z. STILL SOME RATHER STRONG 850 MB MOISTURE CONVERGENCE OVER
SOUTHEAST WISCONSIN OF 25 G/KG/12 HR. THEREFORE STORMS MAY BE A
LITTLE SLOWER EXITING THE SOUTHEAST. THE 00Z NAM INDICATES THE
SEVERE WEATHER THREAT MAY BE A BIT LATER...STILL IN IOWA AROUND
NOON...THEN SHIFTING NORTHEAST INTO WEST CENTRAL TO SOUTH CENTRAL
WISCONSIN BY 7 PM. 0-1 KM CAPE AROUND 1200 TO 1500 J/KG OVER SOUTH
CENTRAL WISCONSIN. 7 PM CDT EHI VALUES AROUND 2 OVER SOUTH CENTRAL
WISCONSIN RISING TO 5 NEAR EAU CLAIRE.
CWASP SEVERE VALUES AROUND 70 PCT OVER WEST CENTRAL WISCONSIN AT
7PM CDT BUT STILL IN THE MID 60S VALUES OVER SOUTH CENTRAL
WISCONSIN AND MID 50 PCT OVER THE SOUTHEAST.
&&
.AVIATION/06Z TAFS/...
EXPECT MVFR CIGS TO SPREAD NORTH AND BECOME IFR DURING THE EARLY
MORNING HOURS AS A WARM FRONT PUSHES NORTH TO THE ILLINOIS BORDER.
SHOWERS AND THUNDERSTORMS ARE EXPECTED LATE TONIGHT WITH SOME
MAINLY SMALL HAIL POSSIBLE...ESPECIALLY OVER THE FAR SOUTH.
THE IFR/MVFR CIGS SHOULD LIFT TO SCATTERED TO BROKEN CU AROUND 3
TO 4 THSD FT.
EXPECT A LULL IN THE THUNDERSTORMS WITH SOUTHERN WISCONSIN IN THE
WARM SECTOR AS STRONG LOW PRESSURE MOVES INTO SOUTHERN MINNESOTA.
EXPECT MORE THUNDERSTORMS LATE SUNDAY AFTERNOON AND EVENING WITH
AN APPROACHING COLD FRONT. SOME OF THESE WILL LIKELY BE SEVERE.
&&
.PREV DISCUSSION... /ISSUED 331 PM CDT SAT APR 14 2012/
SHORT TERM...
TONIGHT- CONFIDENCE...MEDIUM
STRONG 850 THERMAL/MOISTURE ADVECTION PROGGD TO INCREASE AFTER
MIDNIGHT. INCREASING SOUTHWEST 850 MILLIBAR LOW LEVEL JET OF 40-50
KNOTS RAMPS UP. ELEVATED INSTABILITY AND LAPSE RATES NOT
OVERHWHELMING. WILL DELAY THE ONSET OF PRECIP A BIT THIS EVENING
WITH BEST POTENTIAL SETTING UP FOR AFTER MIDNIGHT. VERY HIGH POPS
LOOK GOOD WITH LOW SVR HAIL CHANCES...BUT NON-ZERO. WILL LEAVE
MENTION OF LARGE HAIL OUT OF GRIDS AT THIS TIME.
SUNDAY - CONFIDENCE...MEDIUM
MAIN FOCUS IS ON SEVERE WEATHER POTENTIAL. POSITIVES CERTAINLY
INCLUDE IMPRESSIVE SHEAR...0-6KM OF 90 KNOTS...0-1KM SHEAR OF 50
KNOTS. THESE ARE VERY HIGH VALUES. THE NOSE OF THE LOW LEVEL JET IS
PROGGD INTO SC WI AT 18Z WITH DECENT 850/500 MILLIBAR VEERING WIND
PROFILE AT THIS POINT. DECENT THERMAL/MOISTURE AXIS NOSING INTO THE
AREA. CIPS WARM SEASONAL ANALOGS SUGGEST THIS PATTERN HAS A HISTORY
OF SVR WX IN WISCONSIN 50PCT OF THE TIME WITH A TORNADO HISTORY A
WELL. ON THE NEGATIVE SIDE FOR SPECIFICALLY MKX CWA THE PATTERN ALSO
LOOKS SOMEWHAT SIMILAR TO 4/10/11 WHERE THE BULK OF THE SVR WX WAS
TO OUR NORTH. ALONG THOSE LINES...THE DYNAMICS/UPPER JET ORIENTATION
AND BETTER SOURCE OF LOW LEVEL CONVERGENCE TENDS TO FAVOR AREAS A
LITTLE FURTHER WEST AND NORTH THROUGH 00Z MONDAY. HOWEVER WILL HAVE
TO SEE HOW THIS BOUNDARY PLAYS OUT FROM THE OVERNIGHT ACTIVITY...SO
IF THE BOUNDARY GETS HELD UP SOMEWHAT THIS COULD SHIFT THE TORNADO
THREAT FURTHER SOUTH INTO SRN WI. BUT EVIDENCE AT THE MOMENT IS
POINTING TOWARDS THE BOUNDARY LIFTING NORTH OF THE CWA. STAY TUNED.
DEPENDING ON DEGREE OF CLEARING FROM MORNING ACTIVITY...WINDS MAY
APPROACH OF EXCEED ADVISORY CRITERIA BUT WILL HOLD OFF ON ISSUANCE
AT THIS TIME.
MONDAY-FORECAST CONFIDENCE HIGH
GUIDANCE IN GOOD AGREEMENT IN PULLING DEEP UPPER TROUGH ACROSS
WISCONSIN AND MICHIGAN AND BRINGING A COMPACT COLD POOL FROM A
SECOND UPPER TROUGH ACROSS SOUTH DAKOTA AND TOWARD MN/IA BORDER.
STRONG COLD ADVECTION DURING THE DAY COULD RESULT IN LITTLE RISE
IN TEMPERATURE AND PERHAPS EVEN FALLING AFTERNOON TEMPERATURES.
AS IS OFTEN THE CASE MODELS SPLASH PESKY LIGHT PRECIPITATION OVER
LARGE AREAS BUT IN REALITY IT IS OFTEN DRY. AND AS USUAL NERVOUS
METEOROLOGISTS LIKE ME PUT IN A CHANCE OF SHOWERS TO FEEL SAFE.
TUESDAY-FORECAST CONFIDENCE HIGH
POLAR HIGH PRESSURE IN CONTROL WITH FROSTY START FOLLOWED BY COOL
SUNSHINE AND LIGHT WINDS.
LONG TERM...
WEDNESDAY-FORECAST CONFIDENCE HIGH
MODELS REMAIN IN EXCELLENT AGREEMENT WITH ANOTHER LOW PRESSURE
AREA MOVING ALONG IN FAST WESTERLY FLOW REGIME. NOT A LOT OF
MOISTURE BUT WITH -20C AT 500 MB AND DECENT 850 MB WARM ADVECTION
CHANCE OF SHOWERS AND THUNDERSTORMS SEEMS REASONABLE.
THURSDAY AND FRIDAY-FORECAST CONFIDENCE MEDIUM
TIMING LOOKS PRETTY GOOD FOR ANOTHER LOW THURSDAY NIGHT BUT
LOCATION IS IN QUESTION. GFS/DGEX HAD LOW TRACKING ACROSS MISSOURI
THURSDAY NIGHT WHILE GEM AND ECMWF ARE NEAR SOUTHERN WISCONSIN.
GOOD CHANCE OF SHOWERS GIVEN ECMWF/GEM SOLUTION AND WILL ROLL WITH
THAT.
SATURDAY-FORECAST CONFIDENCE MEDIUM
GFS AND ECMWF REALLY START TO DIFFER AT THIS POINT BUT HAVE RATHER
DRY NORTHWEST FLOW AND SURFACE HIGH PRESSURE OVERHEAD. DGEX IS A
NICE COMPROMISE. KEEPING IT DRY LOOKS LIKE BEST SOLUTION.
AVIATION/00Z TAFS/...VFR CONDITIONS EXPECTED INTO THE EVENING
HOURS. A STRONG WARM FRONT WILL THEN BRING SHOWERS AND THUNDERSTORMS
LATER THIS EVENING INTO THE OVERNIGHT AND EARLY MORNING HOURS SUNDAY.
IFR TO MVFR CIGS AND VSBYS ARE EXPECTED WITH THE TSTORMS AND FOR A
TIME AFTERWARD. THEN TRICKY PART OF FORECAST WILL BE TIMING OF ANY
STG-SVR CONVECTION SUNDAY AFTERNOON/EVENING. THE FAR SE MAY NOT SEE
ANY RENEWED DEVELOPMENT UNTIL SUNDAY EVENING.
MARINE...A GALE WATCH IS IN EFFECT FOR SUNDAY AFTERNOON AND NIGHT
AS WINDY CONDITIONS DEVELOP IN RESPONSE TO STRONG LOW PRESSURE
MOVING FROM SOUTH DAKOTA TO WISCONSIN. A SWLY 60 KT LOW LEVEL JET
STREAM WILL AID IN THE STRONG WIND GUSTS. A SMALL CRAFT ADVISORY MAY
BE NEEDED IN THE WAKE OF THE COLD FRONT FOR MONDAY DUE TO BRISK
NORTHWEST WINDS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...GALE WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY NIGHT FOR
LMZ643>646.
&&
$$
UPDATE...HENTZ
TONIGHT/SUNDAY AND AVIATION/MARINE...COLLAR
SUNDAY NIGHT THROUGH SATURDAY...CRAVEN
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
804 PM CDT SAT APR 14 2012
.UPDATE...ALL EYES OBVIOUSLY ON POTENTIAL FOR SVR WX OUTBREAK
TOMORROW.
FIRST FOR TNGT...GIST OF GOING FCST OKAY. INSTABILITY PERHAPS A
LITTLE SLOWER TO BUILD NWD. DLAD THE ONSET OF PCPN...AND HELD
THUNDER BACK FM LEADING EDGE OF PCPN IN THE GRIDS. MAY END UP WITH
JUST RAIN UNTIL WE GET TOWARD THE BACK EDGE OF THE PCPN
SHIELD...BUT THAT WAS A LITTLE BIGGER FCST CHG THAN COMFORTABLE
MAKING AT THIS POINT. MUCAPES OFF THE 18Z NAM AND 21Z RUC SEEMED
RATHER LOW FOR GETTING MUCH HAIL OVERNIGHT...BUT SINCE WE ONLY HAD
SML HAIL MENTIONED...WL LET IT RIDE.
SITN FOR TOMORROW WAS DESCRIBED AS MUDDLED BY THE DAY SHIFT...AND
THAT/S STILL FITTING. NEED TO MAKE SOME GUESSES ABOUT HOW
CONVECTION WL EVOLVE OVERNIGHT AND EARLY SUN IN ORDER TO LAY OUT
SCENARIO FOR TOMORROW AFTN/EVENING. OF COURSE FCST CAN EASILY JUMP
THE TRACKS IF ANY OF THE SUPPOSITIONS ARE WRONG...BUT HERE GOES
ANYWAY. IT NOW LOOKS LIKE REMNANTS OF MCS OR AT LEAST CLUSTERS OF
STORMS WL STILL BE ONGOING INTO AT LEAST PART OF THE MORNING. THAT
COMBINED WITH SFC LOW STILL OUT IN THE CENTRAL PLAINS AND FCST
AREA STILL RELATIVELY NEAR UPR RIDGE POSN FAVOR A SLOWER NWD MVMT
OF THE WARM FRONT. AND EVEN ONCE FRONT STARTS TO WORK NWD ACRS THE
AREA...THERE WL BE WATER TO EVAPORATE OFF WET SFCS AND LOW CLDS
AND PROBABLY SOME FG TO CHEW THROUGH. MODELS ALL ALSO SUGGESTED
CONSIDERABLE MIDDLE LEVEL MOISTURE LINGERING OVER THE AREA...SO WE
MAY BE HARD PRESSED TO GET MUCH SUNSHINE. WE PROBABLY WL GET A NWD
SURGE IN THE FRONT LATER IN THE DAY AS UPR FLOW BACKS MORE SWLY
AND STRENGTHENS WITH THE APPROACH OF THE UPR TROF...BUT AT THIS
POINT NOT SURE WE/LL EVER BE ABLE TO DRIVE THE WARM FRONT ALL THE
WAY THROUGH THE FCST AREA. SO WHILE WARM FRONT PROBABLY SLOWS OVER
FAR NRN WI...COLD FRONT WL ENTER THE WRN PART OF THE FCST AREA
ARND SUNSET...AND RACE EWD DURING THE EVENING. THE FLOW MAY BE
GETTING MORE UNI-DIRECTIONAL BY THEN...BUT VERY STG WINDS ALOFT
WOULD SUPPORT DAMAGING WIND THREAT...ESP IF CONVECTION CAN
ORGANIZE INTO A MORE SOLID LINE ALONG THE FRONT.
TWEAKED GRIDS WITH CHGS DESCRIBED ABV. WL HAVE UPDATED ZONES OUT
SHORTLY...AND THEN FRESHEN THE WORDING IN THE HWO.
SKOWRONSKI
&&
.PREV DISCUSSION...ISSUED AT 604 PM CDT SAT APR 14 2012...
SHORT TERM...TONIGHT THROUGH SUNDAY...
FOCUS OF THIS FORECAST ON THUNDERSTORM POTENTIAL TONIGHT AND
SUNDAY AND MODERATE RISK FOR SEVERE WEATHER ON SUNDAY.
DEEP UPPER LOW TO LIFT OUT OF THE SOUTHWEST TODAY INTO THE
CENTRAL PLAINS SUN MORN...MOVING INTO SUN EVENING. ASSOCIATED
SURFACE LOW NOW OVER NE KANSAS AND ASSOCIATED WARM FRONT TO MOVE
NORTH...WITH WARM FRONT MOVING THROUGH WI TONIGHT...LIKELY
STALLING OVER NORTHERN WI...THOUGH SOME DIFFERENCE IN MODELS HERE.
EXPECT AREA OF SHOWERS AND STORMS TO LIFT NORTH TONIGHT...MAINLY
AFTER MIDNIGHT. GIVEN SOME SHEER AND LOW WET BULB ZEROS THOUGHTS
GO TOWARD SMALL/NEAR SEVERE HAIL THREAT. INSTABILITY DOES NOT NOT
LOOK OVERLY IMPRESSIVE FOR LARGER HAIL.
SUNDAY IS MORE MUDDLED...EVEN THOUGH MUCH OF AREA NOW UNDER
MODERATE RISK FOR SEVERE THUNDERSTORMS. QUESTIONS INCLUDE ONGOING
SHOWER ACTIVITY AND POTENTIAL FOR CLEARING. MODELS TREND AT
KEEPING CLOUDS OVER CWA. TIMING OF FRONT MOVING THROUGH THE CWA IS
EVENING...WHICH NEVER BODES WELL FOR CLEAR SHOT FOR
SEVERE...ESPECIALLY THIS TIME OF YEAR. MODEL PARAMETERS HIGH AND
DO POINT AT POSSIBLE TORNADOES WITH SIG SHEAR...CAPE...ETC.
THOUGH WITH 5H WINDS AT 70+ KTS SUN AFTN QUESTION IS WHETHER
INSTABILITY WL BE SUFFICIENT GIVEN VERY STG SHEAR. HAVE
HIGHLIGHTED DAMAGING WINDS AS THE MAIN THREAT FOR TOMORROW.
LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. THE SUNDAY NIGHT
INTO MONDAY PERIOD WILL BE DEALING WITH THE AFFECTS OF A DEEP LOW
PRESSURE SYSTEM TRACKING OVER NORTHWEST WISCONSIN. INITIALLY
POSSIBLE STRONG TO SEVERE STORMS MAY STILL BE ONGOING OVER THE
AREA IN THE STRONG SHEARED AND POTENTIALLY UNSTABLE ATMOSPHERE
THROUGH SUNDAY EVENING. TO HIGHLIGHT CONDITIONS FOR LATER
SUNDAY...FOR STARTER...BUFKIT SOUNDINGS SHOW A 50 TO 60 KT WINDS
AT 00Z SUNDAY WITH THE NAM CONSIDERABLY MORE UNSTABLE THAN THE GFS
WITH CAPES OF AROUND 1000 J/KG. HELICITY VALUES ALONG WITH SWEAT
INDEX VALUES ARE VERY HIGH TO SUGGEST A POTENTIAL OF TORNADOES.
LOW WET BULBS COULD ALSO SUPPORT LARGE HAIL. LATER IN THE EVENING
AS THE SURFACE TROUGH WORKS IN...PRIMARY THREAT MAY TURN TO
DAMAGING WINDS ALONG A SQUALL LINE. TIMING OF THIS TROUGH PROVIDES
SOME CHALLENGE ON THE DURATION OF THIS LIKELY SEVERE WEATHER
EVENT...BUT ANTICIPATE THE END LATER EVENING OVER NORTHEAST AND
EASTERN WISCONSIN.
STRONG CAA PATTERN ON THE BACKSIDE OF THE DEEP LOW THEN POURS
INTO THE STATE ON MONDAY WITH A POSSIBLE MIX FAR NORTH BEFORE THE
SYSTEM PULLS OUT.
WEAK SURFACE RIDGE PASSES THE REGION TUESDAY FOLLOWED BY THE NEXT
SYSTEM TRACKING FROM THE NORTHERN PLAINS TO THE GREAT LAKES REGION
AROUND WEDNESDAY. ANOTHER SYSTEM TRACKS OVER LATER IN THE WEEK AND
APPEARS TO BE TRENDING SOUTH OF THE AREA BUT PERHAPS BRUSHING
CENTRAL WISCONSIN WITH LITE PCPN.
&&
.AVIATION...KEPT FLAVOR OF PREV TAF PKG INTACT. MAIN CHG WAS TO
DELAY ONSET OF ELEVATED CONVECTION TNGT A BIT. ALSO KEPT BR/HZ
GOING WELL INTO SUN AS FEEL FRONT WL BE SLOWER TO MV N THAN SHOWN
ON THE PROGS...AND WE/LL HAVE QUITE A BIT OF LOW-LEVEL MOISTURE TO
TRY AND EVAPORATE OFF.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
125 AM CDT SUN APR 15 2012
.MESOSCALE DISCUSSION...
110 AM CDT
THE MESOSCALE CONVECTIVE VORTEX THAT EMANATED FROM CONVECTION IN
KS/NE/IA SATURDAY AFTERNOON IS NOW DECAYING OVER SE WI AS IT
MOVES EAST. REMNANT STORMS HAVE BECOME MORE WEST-TO-EAST ORIENTED
AS THE SYSTEM HAS WEAKENED AND SYNOPTIC FORCING/FLOW/CONVERGENCE
IS TAKING OVER. CONTINUED REGENERATION OF STORMS IS SEEN PER
RADAR AND IR ANALYSIS ACROSS THE DVN CWA AS BROAD SCALE HEIGHT
FALLS WITHIN UPPER LEVEL DIFFLUENCE MOVE OVER THE AREA. THESE
WILL CONTINUE TO PROPAGATE INTO VERY RICH MOISTURE...WITH 700MB
DEW POINTS ON THE ORDER OF 0C-4C...BEING TRANSPORTED NORTHWARD ON
A 60-65 KT LOW-LEVEL JET PER PROFILER ANALYSIS. THIS IS AT A
SOMEWHAT IDEAL 90 DEGREE ANGLE INTO THE WEST-TO-EAST STORM MOTIONS
BEING OBSERVED.
THE STORMS LIE WELL WITHIN ANALYZED DEEP LAYER MOISTURE
CONVERGENCE AND ALONG AN ELEVATED THERMAL/MOISTURE
BOUNDARY...WHICH IS FORECAST TO SLOWLY MOVE NORTH THROUGH THE
OVERNIGHT BY THE RUC MODEL. THIS NORTHWARD MOTION MAY BE VERY SLOW
TO HAPPEN HOWEVER WITH SUPPRESSION IN THE WAKE OF THE MCV TO THE
NORTH OF THIS BOUNDARY ACROSS NE IA/SW WI. THUS...IN COORDINATING
WITH NESDIS...WE DO EXPECT CONTINUED EFFICIENT RAINFALL PRODUCING
THUNDERSTORMS ACROSS THE WESTERN AND NORTHERN FORECAST AREA
OVERNIGHT.
RAINFALL RATES IN THE PAST HOUR ACROSS THE DVN FORECAST AREA ARE
INDICATIVE OF THREE QUARTER TO ONE INCH OF RAIN PER HOUR
RATES IN SWATHS...AND GIVEN THE AREAL COVERAGE OF 45-50 DBZ
/WHICH CORRELATES TO AT LEAST ONE INCH OF RAIN IN CONVECTIVE
REGIMES/...EXPECT THAT TO BE THE GENERAL TREND INTO THE WESTERN
FORECAST AREA...WITH LOCALIZED HIGHER AMOUNTS LIKELY. THREE HOUR
FLASH FLOOD GUIDANCE OF 2.25 TO 3.25 INCHES SHOULD HOLD IN MOST
PLACES. WILL HAVE TO WATCH...ESPECIALLY IF ANY MORE WAVES OF
STORMS PASS OVER ROCKFORD...FOR POSSIBLE FLOOD STATEMENTS OR
WARNINGS. WOULD EXPECT IT TO BE A LOCALIZED ENOUGH THREAT FOR NO
FLOOD WATCH...BUT WILL HAVE TO RE-EVALUATE LOOKING AT THE BIG
PICTURE THROUGH SUNDAY AND SUNDAY NIGHT.
MTF
&&
.DISCUSSION...
838 PM CDT
UPDATE FOR TONIGHT...
DEEPENING SURFACE LOW CURRENTLY OVER CENTRAL NEB WITH GREATEST
PRESSURE FALLS TO THE N THROUGH ENE OF THE LOW ACROSS SD...SW MN
AND NW IA. A SMALLER SEPARATE PRESSURE FALL CENTER HAS MOVED E
FROM SE NEB TO S CENTRAL IA OVER THE LAST 3 HRS JUST AHEAD OF THE
ENE MOVING MCV...WHICH IS NOW SW OF DSM. CONTINUING ON THIS PATH
WOULD TAKE IT TO THE WESTERN IL-WI STATE LINE 05-06Z TIME FRAME
AND THEN ON INTO S CENTRAL WI OVERNIGHT.
LOW LEVELS ARE STABLE ACROSS N CENTRAL AND NE IL...AS WELL AS NW
IND WITH DEW POINTS STILL IN THE 50S N OF THE WARM FRONT AND
TEMPERATURES HELD DOWN TO MAINLY THE MID 60S AS DENSE ANVIL
BLOW-OFF COVERED THE AREA THROUGH THE DAY. HOWEVER...MODELS
INDICATE THAT LOCAL MID LEVELS WILL DESTABILIZE DURING THE REST
OF THE EVENING WITH SHOWALTER INDEX FALLING TO -2...MU CAPE
RISING TO 400-600 J/KG AND TOTAL TOTALS REACHING 50+ BY 06Z.
VAD AND PROFILER WINDS HAVE SHOWN A STRENGTHENING OF THE LLJ
PUSHING E TO THE MS RIVER AND MODELS CONTINUE THIS TREND
EXTENDING THE NOSE OF THE LLJ NE TO SOUTHERN LAKE MI AND SOUTHERN
LOWER MI BY 12Z. WITH INCREASING ISENTROPIC LIFT IN THE MID
LEVELS OCCURRING BELIEVE THAT SHOWERS AND T-STORMS IN SE IA AND
EXTREME NE MO WILL CONTINUE TO SPREAD E ACROSS THE MS RIVER AND
LIFT NORTHEASTWARD AND EVENTUALLY OVER THE FORECAST AREA DURING
THE LATE EVENING AND OVERNIGHT N OF THE WARM FRONT TO BE LIFTING
ACROSS CENTRAL TO NORTHERN IL DURING THE NIGHT.
LATEST RUNS OF HI RESOLUTION MODELS INCLUDING HRRR...RUC13 AND
VSREF HAVE RAIN REACHING IROQUOIS AND LIVINGSTON COUNTIES 04-05Z
AND INTO THE CHICAGO METRO AREA 06-07Z. THIS TIMING LOOKS
REASONABLE.
TRS
//PREV DISCUSSION...
305 PM CDT
MAIN CONCERN FOR THE AFTERNOON UPDATE WILL FOCUS ON SEVERE WEATHER
POTENTIAL FOR TOMORROW...BUT CHANCES FOR THUNDERSTORMS OVERNIGHT
TONIGHT WILL BE A CONCERN AS WELL.
FOR THE REMAINDER OF THIS AFTERNOON AND INTO EARLY THIS
EVENING...CONDITIONS ACROSS THE AREA WILL BE RELATIVELY QUIET AS THE
EARLIER SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A LEAD SHORTWAVE
HAVE MOVED WELL EAST INTO THE UPPER OHIO VALLEY. IN THE MEAN
TIME...LOW PRESSURE IS DEVELOPING OVER THE WESTERN PLAINS WITH A
WARM FRONT EXTENDING EAST THROUGH NRN MO AND CNTRL IL/IN. THIS WARM
FRONT WILL BECOME THE FOCUS FOR NEW THUNDERSTORM DEVELOPMENT
OVERNIGHT TONIGHT AS IT LIFTS NWD. ANTICIPATE THAT THE WRMFNT WILL
TRAVERSE THE CWA BTWN 03Z-09Z WITH OVERRUNNING PCPN AND ELEVATED
CONVECTION POSSIBLE NORTH OF THE WARM FRONT THROUGH THE EVENING AND
POSSIBLY TRANSITIONING TO MORE SFC BASED CONVECTION AS THE WARM
SECTOR OVERSPREADS THE ENTIRE CWA DURG THE EARLY MORNING HOURS.
GIVEN THE MAIN SFC LOW IS WELL TO THE WEST AND THE LESS THAN
FAVORABLE TIME THAT THE WARM FRONT IS LIFTING THROUGH THE CWA...DO
NOT ANTICIPATE A SGFNT SEVERE THREAT WITH STORMS DEVELOPING
OVERNIGHT TONIGHT...BUT WITH DEEP LAYER MOISTURE ON THE
INCREASE...OCNL HEAVY DOWNPOURS AND PERIODS OF SMALL HAIL ARE VERY
LIKELY.
THE MAIN FOCUS FOR THE SEVERE WEATHER CONCERN WILL BE TAKING SHAPE
FOR TOMORROW. THE SHORT RANGE MODEL GUIDANCE IS CONVERGING ON
REASONABLY DECENT CONSISTENCY IN DEEPENING THE WRN PLAINS SFC LOW AS
IT LIFTS NEWD THROUGH THE PLAINS AND INTO THE UPPER MISSOURI VALLEY
BY SUNDAY AFTERNOON AND INTO THE UPPER MISSOURI VALLEY BY SUNDAY
EVENING. THROUGH THE DAY...A STRONG LOW LEVEL JET WILL SET UP WITH
SWLY WINDS OF 55-60KT OVER NRN IL AND INTO WISCONSIN. SFC WINDS ARE
EXPECTED TO BACK SSELY THROUGH THE DAY TOMORROW ENHANCING THE LOW
LEVEL SHEAR PROFILE. STRONG WARM ADVECTION WILL ALLOW SFC
TEMPERATURES TO RISE INTO THE UPPER 70S TO LOWER 80S. THE
COMBINATION OF HEAT AND HUMIDITY WILL SET UP A VERY UNSTABLE
ENVIRONMENT. MODEL SOUNDINGS INDICATE SOME WEAK CAPPING INTO THE
EARLY AFTERNOON...BUT EXPECTED SFC WARMING SHOULD HAVE NO PROBLEM
OVERCOMING AND WEAK CAPPING AND CONVECTIVE INITIATION IS LIKELY
OVER THE WRN PORTIONS OF THE CWA...FROM I-39 TO THE MISSISSIPPI
RIVER DURING THE AFTERNOON. GIVEN THE MODEST LOW LEVEL WIND
SHEAR...THE INITIAL CONVECTIVE MODE WILL BE CONDUCIVE TO DISCRETE
SUPERCELLS WITH LARGE HAIL...STRONG DAMAGING WINDS AND EVEN ISOLATED
TORNADOES ARE A POSSIBILITY. ALSO THROUGH THE DAYTIME
HOURS...STRONG SYNOPTIC WINDS WILL BE A CONCERN EVEN BEFORE
CONVECTIVE INITIATION. A STRENGTHENING PRESSURE GRADIENT EAST OF
THE DEEPENING SFC LOW WILL DRIVE SLY WINDS TO 25KT THROUGH THE
MORNING HOURS AND WITH DAYTIME WARMING...MIXING WILL BEGIN TO TAP
THE STRONG WINDS ALOFT AND EXPECT SYNOPTIC SCALE WIND GUSTS OF 35 TO
40KT OVER THE ENTIRE CWA IN ADDITION TO ANY LOCALLY HIGHER
THUNDERSTORM GENERATED WIND GUSTS.
BY EARLY EVENING...THE DISCRETE SUPERCELL THREAT SHOULD MORPH INTO A
LINEAR SQUALL LINE MODE. AT THIS TIME...EXPECT THAT THE WRN
PORTIONS OF THE CWA...GENERALLY ALONG AND WEST OF THE I-39 CORRIDOR
WILL HAVE THE GREATEST DISCRETE SUPERCELL POTENTIAL DURING THE
AFTERNOON. THE TRANSITION OVER TO A LINEAR SQUALL LINE MODE SHOULD
OCCUR DURING THE EARLY EVENING HOURS OVER THE CENTRAL PORTIONS OF
THE CWA...GENERALLY BETWEEN I-39 AND I-55...AND THEN STEADILY MARCH
EWD THROUGH THE NIGHT...EXITING THE NWRN INDIANA COUNTIES DURG THE
EARLY MORNING HOURS. WITH THE TRANSITION FROM DISCRETE SUPERCELL TO
LINEAR SQUALL LINE...THE MAIN SEVERE THREAT WILL FOCUS ON STRONG
DAMAGING WINDS. LOCALLY HEAVY RAINFALL MAY ALSO BECOME A CONCERN
OVERNIGHT AS PRECIPITABLE WATER VALUES OVER THE AREA SHOULD BE IN
EXCESS OF 1.5 INCHES AND ANY ECHO TRAINING ALONG THE MAIN CONVECTIVE
LINE COULD LEAD TO LOCALIZED FLASH FLOODING.
BY DAYBREAK MONDAY MORNING...THE MAIN UPPER TROUGH SHOULD PUSH
THROUGH THE UPPER MIDWEST AND GREAT LAKES REGIONS...FORCING THE SFC
COLD FRONT EAST OF THE CWA. THIS SHOULD BRING A QUICK END TO ANY
PCPN POTENTIAL AND MONDAY SHOULD BRING DECREASING CLOUD COVER AND
LITTLE DIURNAL TEMPERATURE SWING THROUGH THE DAY WITH PERSISTENT
COLD ADVECTION SETTING UP BEHIND THE COLD FRONT. TEMPERATURES ON
MONDAY SHOULD ONLY BE IN THE MIDDLE 50S TO MIDDLE 60S. HIGH
PRESSURE WILL QUICKLY BUILD IN OVER MONDAY NIGHT AND
TUESDAY...KEEPING CONDITIONS RELATIVELY COOLER AND DRIER.
FOR THE EXTENDED PERIOD...FROM WEDNESDAY THROUGH SATURDAY...A
RELATIVELY HIGH AMPLITUDE...BUT PROGRESSIVE PATTERN WILL SET UP.
THE NEXT SIGNIFICANT CHANCE FOR PCPN WILL BE ON THURSDAY NIGHT AND
FRIDAY AS A NRN STREAM SHORT WAVE DROPPING OUT OF THE
ROCKIES...LEADING TO STRONG SFC DEVELOPMENT OVER THE CNTRL PLAINS.
THE MAIN SFC LOW SHOULD TRACK THROUGH THE LOCALLY LATE THURSDAY
NIGHT AND FRIDAY...BRINGING THE NEXT CHANCE FOR SHOWERS AND
THUNDERSTORMS TO THE AREA.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* THUNDERSTORMS OVERNIGHT AND TOWARD MORNING WITH ASSOCIATED LOW
CIGS/VSBYS.
* ADDITIONAL THUNDERSTORMS POSSIBLE DURING THE DAY...MOST LIKELY
LATER TOWARD AFTERNOON AND EVENING.
LENNING
//DISCUSSION...UPDATED 06Z...
RADAR AND LIGHTNING DISPLAY AT THIS HOUR SHOWS LINES OF
THUNDERSTORMS STRETCHING FROM THE CHICAGO AREA WEST ACROSS IOWA
INTO SOUTHERN MINNESOTA...THEN SOUTH IN A NEARLY UNBROKEN SWATH
FROM MINNESOTA INTO TEXAS. THE FIRST LINE OF STORMS TO REACH THE
TERMINALS HAS MOSTLY MOVED THROUGH MDW AT THIS TIME...ALTHOUGH
ORD IS CLOSER TO THE EMBEDDED NORTH-SOUTH ORIENTED SECTIONS OF
THE LINE AND WILL SEE MORE PROLONGED TSRA ACTIVITY. MDW WILL SEE A
SHORT BREAK BEFORE THE NEXT ROUND ARRIVES AROUND 08-09Z...WHILE
ORD MAY SEE ONLY A SHORT BREAK OR NONE AT ALL.
THE BIGGER QUESTIONS CENTER AROUND DAYBREAK WHEN TRAFFIC IS
SCHEDULED TO PICK UP. GENERALLY THE THOUGHT IS OVERNIGHT ACTIVITY
WILL DISSIPATE OR LIFT NORTH BY MORNING...WITH THE NEXT ROUND
ARRIVING WHEN THE LINE NOW RUNNING FROM MN TO TX REACHES THE AREA
LATE IN THE DAY.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE OF MULTIPLE ROUNDS OF THUNDERSTORMS OVERNIGHT.
* LOW CONFIDENCE ON COVERAGE OF STORMS INTO THE 12-13Z PERIOD
WHEN TRAFFIC STARTS TO PICK UP.
* LOW CONFIDENCE ON COVERAGE OF ANY TSRA ACTIVITY DURING THE
MORNING AND AFTERNOON.
* MEDIUM TO HIGH CONFIDENCE OF ANOTHER ROUND OF STORMS LATER IN
THE DAY.
LENNING
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR. CHC MVFR W/CHC SHRA EARLY.
TUESDAY...VFR.
WEDNESDAY...VFR. CHC MVFR CIGS W/SHRA ISO TSRA MIDDAY/AFTN.
THURSDAY...VFR. CHC SHRA.
FRIDAY...VFR. CHC SHRA ISO TSRA.
BEACHLER
&&
.MARINE...
257 PM...FORECAST REMAINS ACTIVE THROUGH MONDAY NIGHT WITH SOME
UNCERTAINTY REGARDING HOW HIGH WIND SPEEDS/GUSTS WILL BECOME. LOW
PRESSURE OVER WESTERN ONTARIO WILL MOVE EAST INTO NORTHERN QUEBEC
BY SUNDAY AFTERNOON. A TRAILING FRONTAL BOUNDARY FROM THIS LOW
WILL LIKELY SAG SOUTH ACROSS FAR NORTHERN LAKE MICHIGAN TONIGHT
TURNING WINDS EASTERLY. UNTIL THEN...THE GRADIENT WILL SUPPORT 15
TO 25 KTS ON THE NORTH END OF THE LAKE INTO EARLY THIS EVENING.
MEANWHILE LOW PRESSURE OVER EASTERN COLORADO WILL MOVE NORTHEAST
ACROSS THE PLAINS TONIGHT AND SUNDAY REACHING THE UPPER PENINSULA
OF MICHIGAN BY MONDAY MORNING. THE GRADIENT WILL TIGHTEN AS THIS
LOW APPROACHES. BUT WITH STRONG WARM AIR SPREADING OVER THE COOLER
WATER...CONFIDENCE REGARDING JUST HOW STRONG THE WINDS WILL BECOME
OVER THE OPEN WATERS REMAINS LOW. ITS POSSIBLE THAT THE GRADIENT
MAY BECOME TIGHT ENOUGH FOR LOW END GALES EVEN WITH A LACK OF
MIXING. IF THIS WERE TO OCCUR...THE BEST TIMING WOULD LIKELY BE
SUNDAY EVENING. FOR NOW...HAVE MAINTAINED WINDS TO 30KTS. AND HAVE
ALSO MAINTAINED THE GALE WATCH FOR THE INDIANA/ILLINOIS NEARSHORE
WATERS WITH STRONG WINDS/GUSTS EXPECTED OVER LAND...SPREADING
ACROSS THE NEARSHORE WATERS. AS THE LOW ELONGATES AND LIFTS
NORTHEAST...WINDS WILL SHIFT WESTERLY BY MIDDAY MONDAY AND THEN
NORTHWEST BY MONDAY EVENING. THE GRADIENT APPEARS STRONG ENOUGH
THAT A SHORT PERIOD OF GALES WILL BE POSSIBLE ACROSS NORTHERN LAKE
MICHIGAN MONDAY AFTERNOON. HIGH PRESSURE SPREADS ACROSS THE LAKES
REGION LATE MONDAY NIGHT...CROSSING THE LAKE TUESDAY AFTERNOON
WITH A PERIOD OF LIGHT WINDS EXPECTED...ALONG WITH LAKE BREEZES ON
THE ILLINOIS/INDIANA NEARSHORE WATERS. LOW PRESSURE MOVING ACROSS
THE PLAINS TUESDAY NIGHT INTO WEDNESDAY WILL QUICKLY TIGHTEN A
SOUTHERLY GRADIENT TUESDAY NIGHT INTO WEDNESDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...6 AM SUNDAY TO NOON SUNDAY.
GALE WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...NOON
SUNDAY TO 10 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
112 AM CDT SUN APR 15 2012
.MESOSCALE DISCUSSION...
110 AM CDT
THE MESOSCALE CONVECTIVE VORTEX THAT EMANATED FROM CONVECTION IN
KS/NE/IA SATURDAY AFTERNOON IS NOW DECAYING OVER SE WI AS IT
MOVES EAST. REMNANT STORMS HAVE BECOME MORE WEST-TO-EAST ORIENTED
AS THE SYSTEM HAS WEAKENED AND SYNOPTIC FORCING/FLOW/CONVERGENCE
IS TAKING OVER. CONTINUED REGENERATION OF STORMS IS SEEN PER
RADAR AND IR ANALYSIS ACROSS THE DVN CWA AS BROAD SCALE HEIGHT
FALLS WITHIN UPPER LEVEL DIFFLUENCE MOVE OVER THE AREA. THESE
WILL CONTINUE TO PROPAGATE INTO VERY RICH MOISTURE...WITH 700MB
DEW POINTS ON THE ORDER OF 0C-4C...BEING TRANSPORTED NORTHWARD ON
A 60-65 KT LOW-LEVEL JET PER PROFILER ANALYSIS. THIS IS AT A
SOMEWHAT IDEAL 90 DEGREE ANGLE INTO THE WEST-TO-EAST STORM MOTIONS
BEING OBSERVED.
THE STORMS LIE WELL WITHIN ANALYZED DEEP LAYER MOISTURE
CONVERGENCE AND ALONG AN ELEVATED THERMAL/MOISTURE
BOUNDARY...WHICH IS FORECAST TO SLOWLY MOVE NORTH THROUGH THE
OVERNIGHT BY THE RUC MODEL. THIS NORTHWARD MOTION MAY BE VERY SLOW
TO HAPPEN HOWEVER WITH SUPPRESSION IN THE WAKE OF THE MCV TO THE
NORTH OF THIS BOUNDARY ACROSS NE IA/SW WI. THUS...IN COORDINATING
WITH NESDIS...WE DO EXPECT CONTINUED EFFICIENT RAINFALL PRODUCING
THUNDERSTORMS ACROSS THE WESTERN AND NORTHERN FORECAST AREA
OVERNIGHT.
RAINFALL RATES IN THE PAST HOUR ACROSS THE DVN FORECAST AREA ARE
INDICATIVE OF THREE QUARTER TO ONE INCH OF RAIN PER HOUR
RATES IN SWATHS...AND GIVEN THE AREAL COVERAGE OF 45-50 DBZ
/WHICH CORRELATES TO AT LEAST ONE INCH OF RAIN IN CONVECTIVE
REGIMES/...EXPECT THAT TO BE THE GENERAL TREND INTO THE WESTERN
FORECAST AREA...WITH LOCALIZED HIGHER AMOUNTS LIKELY. THREE HOUR
FLASH FLOOD GUIDANCE OF 2.25 TO 3.25 INCHES SHOULD HOLD IN MOST
PLACES. WILL HAVE TO WATCH...ESPECIALLY IF ANY MORE WAVES OF
STORMS PASS OVER ROCKFORD...FOR POSSIBLE FLOOD STATEMENTS OR
WARNINGS. WOULD EXPECT IT TO BE A LOCALIZED ENOUGH THREAT FOR NO
FLOOD WATCH...BUT WILL HAVE TO RE-EVALUATE LOOKING AT THE BIG
PICTURE THROUGH SUNDAY AND SUNDAY NIGHT.
MTF
&&
.DISCUSSION...
838 PM CDT
UPDATE FOR TONIGHT...
DEEPENING SURFACE LOW CURRENTLY OVER CENTRAL NEB WITH GREATEST
PRESSURE FALLS TO THE N THROUGH ENE OF THE LOW ACROSS SD...SW MN
AND NW IA. A SMALLER SEPARATE PRESSURE FALL CENTER HAS MOVED E
FROM SE NEB TO S CENTRAL IA OVER THE LAST 3 HRS JUST AHEAD OF THE
ENE MOVING MCV...WHICH IS NOW SW OF DSM. CONTINUING ON THIS PATH
WOULD TAKE IT TO THE WESTERN IL-WI STATE LINE 05-06Z TIME FRAME
AND THEN ON INTO S CENTRAL WI OVERNIGHT.
LOW LEVELS ARE STABLE ACROSS N CENTRAL AND NE IL...AS WELL AS NW
IND WITH DEW POINTS STILL IN THE 50S N OF THE WARM FRONT AND
TEMPERATURES HELD DOWN TO MAINLY THE MID 60S AS DENSE ANVIL
BLOW-OFF COVERED THE AREA THROUGH THE DAY. HOWEVER...MODELS
INDICATE THAT LOCAL MID LEVELS WILL DESTABILIZE DURING THE REST
OF THE EVENING WITH SHOWALTER INDEX FALLING TO -2...MU CAPE
RISING TO 400-600 J/KG AND TOTAL TOTALS REACHING 50+ BY 06Z.
VAD AND PROFILER WINDS HAVE SHOWN A STRENGTHENING OF THE LLJ
PUSHING E TO THE MS RIVER AND MODELS CONTINUE THIS TREND
EXTENDING THE NOSE OF THE LLJ NE TO SOUTHERN LAKE MI AND SOUTHERN
LOWER MI BY 12Z. WITH INCREASING ISENTROPIC LIFT IN THE MID
LEVELS OCCURRING BELIEVE THAT SHOWERS AND T-STORMS IN SE IA AND
EXTREME NE MO WILL CONTINUE TO SPREAD E ACROSS THE MS RIVER AND
LIFT NORTHEASTWARD AND EVENTUALLY OVER THE FORECAST AREA DURING
THE LATE EVENING AND OVERNIGHT N OF THE WARM FRONT TO BE LIFTING
ACROSS CENTRAL TO NORTHERN IL DURING THE NIGHT.
LATEST RUNS OF HI RESOLUTION MODELS INCLUDING HRRR...RUC13 AND
VSREF HAVE RAIN REACHING IROQUOIS AND LIVINGSTON COUNTIES 04-05Z
AND INTO THE CHICAGO METRO AREA 06-07Z. THIS TIMING LOOKS
REASONABLE.
TRS
//PREV DISCUSSION...
305 PM CDT
MAIN CONCERN FOR THE AFTERNOON UPDATE WILL FOCUS ON SEVERE WEATHER
POTENTIAL FOR TOMORROW...BUT CHANCES FOR THUNDERSTORMS OVERNIGHT
TONIGHT WILL BE A CONCERN AS WELL.
FOR THE REMAINDER OF THIS AFTERNOON AND INTO EARLY THIS
EVENING...CONDITIONS ACROSS THE AREA WILL BE RELATIVELY QUIET AS THE
EARLIER SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A LEAD SHORTWAVE
HAVE MOVED WELL EAST INTO THE UPPER OHIO VALLEY. IN THE MEAN
TIME...LOW PRESSURE IS DEVELOPING OVER THE WESTERN PLAINS WITH A
WARM FRONT EXTENDING EAST THROUGH NRN MO AND CNTRL IL/IN. THIS WARM
FRONT WILL BECOME THE FOCUS FOR NEW THUNDERSTORM DEVELOPMENT
OVERNIGHT TONIGHT AS IT LIFTS NWD. ANTICIPATE THAT THE WRMFNT WILL
TRAVERSE THE CWA BTWN 03Z-09Z WITH OVERRUNNING PCPN AND ELEVATED
CONVECTION POSSIBLE NORTH OF THE WARM FRONT THROUGH THE EVENING AND
POSSIBLY TRANSITIONING TO MORE SFC BASED CONVECTION AS THE WARM
SECTOR OVERSPREADS THE ENTIRE CWA DURG THE EARLY MORNING HOURS.
GIVEN THE MAIN SFC LOW IS WELL TO THE WEST AND THE LESS THAN
FAVORABLE TIME THAT THE WARM FRONT IS LIFTING THROUGH THE CWA...DO
NOT ANTICIPATE A SGFNT SEVERE THREAT WITH STORMS DEVELOPING
OVERNIGHT TONIGHT...BUT WITH DEEP LAYER MOISTURE ON THE
INCREASE...OCNL HEAVY DOWNPOURS AND PERIODS OF SMALL HAIL ARE VERY
LIKELY.
THE MAIN FOCUS FOR THE SEVERE WEATHER CONCERN WILL BE TAKING SHAPE
FOR TOMORROW. THE SHORT RANGE MODEL GUIDANCE IS CONVERGING ON
REASONABLY DECENT CONSISTENCY IN DEEPENING THE WRN PLAINS SFC LOW AS
IT LIFTS NEWD THROUGH THE PLAINS AND INTO THE UPPER MISSOURI VALLEY
BY SUNDAY AFTERNOON AND INTO THE UPPER MISSOURI VALLEY BY SUNDAY
EVENING. THROUGH THE DAY...A STRONG LOW LEVEL JET WILL SET UP WITH
SWLY WINDS OF 55-60KT OVER NRN IL AND INTO WISCONSIN. SFC WINDS ARE
EXPECTED TO BACK SSELY THROUGH THE DAY TOMORROW ENHANCING THE LOW
LEVEL SHEAR PROFILE. STRONG WARM ADVECTION WILL ALLOW SFC
TEMPERATURES TO RISE INTO THE UPPER 70S TO LOWER 80S. THE
COMBINATION OF HEAT AND HUMIDITY WILL SET UP A VERY UNSTABLE
ENVIRONMENT. MODEL SOUNDINGS INDICATE SOME WEAK CAPPING INTO THE
EARLY AFTERNOON...BUT EXPECTED SFC WARMING SHOULD HAVE NO PROBLEM
OVERCOMING AND WEAK CAPPING AND CONVECTIVE INITIATION IS LIKELY
OVER THE WRN PORTIONS OF THE CWA...FROM I-39 TO THE MISSISSIPPI
RIVER DURING THE AFTERNOON. GIVEN THE MODEST LOW LEVEL WIND
SHEAR...THE INITIAL CONVECTIVE MODE WILL BE CONDUCIVE TO DISCRETE
SUPERCELLS WITH LARGE HAIL...STRONG DAMAGING WINDS AND EVEN ISOLATED
TORNADOES ARE A POSSIBILITY. ALSO THROUGH THE DAYTIME
HOURS...STRONG SYNOPTIC WINDS WILL BE A CONCERN EVEN BEFORE
CONVECTIVE INITIATION. A STRENGTHENING PRESSURE GRADIENT EAST OF
THE DEEPENING SFC LOW WILL DRIVE SLY WINDS TO 25KT THROUGH THE
MORNING HOURS AND WITH DAYTIME WARMING...MIXING WILL BEGIN TO TAP
THE STRONG WINDS ALOFT AND EXPECT SYNOPTIC SCALE WIND GUSTS OF 35 TO
40KT OVER THE ENTIRE CWA IN ADDITION TO ANY LOCALLY HIGHER
THUNDERSTORM GENERATED WIND GUSTS.
BY EARLY EVENING...THE DISCRETE SUPERCELL THREAT SHOULD MORPH INTO A
LINEAR SQUALL LINE MODE. AT THIS TIME...EXPECT THAT THE WRN
PORTIONS OF THE CWA...GENERALLY ALONG AND WEST OF THE I-39 CORRIDOR
WILL HAVE THE GREATEST DISCRETE SUPERCELL POTENTIAL DURING THE
AFTERNOON. THE TRANSITION OVER TO A LINEAR SQUALL LINE MODE SHOULD
OCCUR DURING THE EARLY EVENING HOURS OVER THE CENTRAL PORTIONS OF
THE CWA...GENERALLY BETWEEN I-39 AND I-55...AND THEN STEADILY MARCH
EWD THROUGH THE NIGHT...EXITING THE NWRN INDIANA COUNTIES DURG THE
EARLY MORNING HOURS. WITH THE TRANSITION FROM DISCRETE SUPERCELL TO
LINEAR SQUALL LINE...THE MAIN SEVERE THREAT WILL FOCUS ON STRONG
DAMAGING WINDS. LOCALLY HEAVY RAINFALL MAY ALSO BECOME A CONCERN
OVERNIGHT AS PRECIPITABLE WATER VALUES OVER THE AREA SHOULD BE IN
EXCESS OF 1.5 INCHES AND ANY ECHO TRAINING ALONG THE MAIN CONVECTIVE
LINE COULD LEAD TO LOCALIZED FLASH FLOODING.
BY DAYBREAK MONDAY MORNING...THE MAIN UPPER TROUGH SHOULD PUSH
THROUGH THE UPPER MIDWEST AND GREAT LAKES REGIONS...FORCING THE SFC
COLD FRONT EAST OF THE CWA. THIS SHOULD BRING A QUICK END TO ANY
PCPN POTENTIAL AND MONDAY SHOULD BRING DECREASING CLOUD COVER AND
LITTLE DIURNAL TEMPERATURE SWING THROUGH THE DAY WITH PERSISTENT
COLD ADVECTION SETTING UP BEHIND THE COLD FRONT. TEMPERATURES ON
MONDAY SHOULD ONLY BE IN THE MIDDLE 50S TO MIDDLE 60S. HIGH
PRESSURE WILL QUICKLY BUILD IN OVER MONDAY NIGHT AND
TUESDAY...KEEPING CONDITIONS RELATIVELY COOLER AND DRIER.
FOR THE EXTENDED PERIOD...FROM WEDNESDAY THROUGH SATURDAY...A
RELATIVELY HIGH AMPLITUDE...BUT PROGRESSIVE PATTERN WILL SET UP.
THE NEXT SIGNIFICANT CHANCE FOR PCPN WILL BE ON THURSDAY NIGHT AND
FRIDAY AS A NRN STREAM SHORT WAVE DROPPING OUT OF THE
ROCKIES...LEADING TO STRONG SFC DEVELOPMENT OVER THE CNTRL PLAINS.
THE MAIN SFC LOW SHOULD TRACK THROUGH THE LOCALLY LATE THURSDAY
NIGHT AND FRIDAY...BRINGING THE NEXT CHANCE FOR SHOWERS AND
THUNDERSTORMS TO THE AREA.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* AREA OF SHOWERS/THUNDERSTORMS OVER IA SLIDING EAST ARRIVING ARND
7Z AT TERMINALS.
* ISO IFR CIGS DEVELOPING...OTHERWISE MAINLY LOW END MVFR CIGS.
* STRONG SOUTH WINDS SUN MIDDAY/AFTN...GUSTS UP TO 40 MPH.
BEACHLER
//DISCUSSION...UPDATED 00Z...
VERY DYNAMIC AND POTENT SYSTEM CONTINUES TO DEVELOP. CURRENT
GUIDANCE HAS THE MAIN LOW PRESSURE CENTER WELL TO THE WEST OF
NORTHERN IL/NORTHWEST IN THROUGH THE OVERNIGHT PERIOD...AS A
FRONTAL BOUNDARY CURRENTLY OVER SOUTHERN IL RACES NORTH THIS
EVENING. AS THIS BOUNDARY APPROACHES THE AREA...SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO ACCOMPANY THIS BOUNDARY. GUIDANCE
HAS CORRECTED SLIGHTLY TOWARDS A FOCUS OF 07Z SUN FOR ARRIVAL.
HAVE CONTINUED THIS WITHIN THE CURRENT TAF PKG...AND AS THE
BOUNDARY LIFTS NORTH OVERNIGHT THE BETTER CHC FOR CONVECTION WILL
LIFT NORTH WITH IT AS WELL. THE OTHER ITEM TO NOTE IS THAT
GUIDANCE HAS STEADILY PROGGED A LLVL JET ARND 2KFT AGL OF 40 TO 50
KT DEVELOPING AND LIFTING OVER THE AIRFIELDS OVERNIGHT. HAVE
HANDLED THIS WITH A MENTION OF WS WITHIN THE TAF. THEN SHORTLY AFT
DAYBREAK SUN STRONG SOUTHERLY WINDS WILL MIX DOWN TO THE SFC AND
ERODE THE WS. GUSTS BY SUN AFTN COULD APPROACH 30-35KT AT TIMES.
THE NEXT FOCUS WILL TURN TOWARDS CONVECTION
DEVELOPMENT...TIMING...AND COVERAGE FOR SUN AFTN/EVE. AT THIS TIME
IT APPEARS THUNDER WILL REMAIN OUT OF THE AIRFIELDS UNTIL CLOSER
TO 22 SUN - 00Z MON. HOWEVER...THIS COULD CHANGE QUICKLY DEPENDING
ON THE SPEED AND PLACEMENT OF THE OVERNIGHT THUNDERSTORMS.
THE THIRD CHALLENGE RESIDES WITH HOW LOW CIGS WILL BE. FEEL THE
IFR CIGS ARE STILL PSBL...HOWEVER HAVE A SLIGHTLY LOWER CONFIDENCE
IN THIS. HAVE BACKED OFF TO LOW END MVFR CIGS...AND COULD SEE THIS
FLIRTING WITH IFR CIGS OVERNIGHT. IT WILL ALL HINGE UPON PRECIP
COVERAGE/INTENSITY. THEN WITH BETTER MIXING AFT SUNRISE...CIGS
WILL IMPROVE BACK TO VFR CONDS.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM CONFIDENCE IN WIND FORECAST.
* MEDIUM/HIGH CONFIDENCE IN WS FORECAST.
* LOW CONFIDENCE IN PRECIP TIMING/COVERAGE.
* MEDIUM CONFIDENCE IN CIGS FORECAST.
* LOW CONFIDENCE ON PRECIP/CONVECTION TIMING SUN AFTN/EVE.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR. CHC MVFR W/CHC SHRA EARLY.
TUESDAY...VFR.
WEDNESDAY...VFR. CHC MVFR CIGS W/SHRA ISO TSRA MIDDAY/AFTN.
THURSDAY...VFR. CHC SHRA.
FRIDAY...VFR. CHC SHRA ISO TSRA.
BEACHLER
&&
.MARINE...
257 PM...FORECAST REMAINS ACTIVE THROUGH MONDAY NIGHT WITH SOME
UNCERTAINTY REGARDING HOW HIGH WIND SPEEDS/GUSTS WILL BECOME. LOW
PRESSURE OVER WESTERN ONTARIO WILL MOVE EAST INTO NORTHERN QUEBEC
BY SUNDAY AFTERNOON. A TRAILING FRONTAL BOUNDARY FROM THIS LOW
WILL LIKELY SAG SOUTH ACROSS FAR NORTHERN LAKE MICHIGAN TONIGHT
TURNING WINDS EASTERLY. UNTIL THEN...THE GRADIENT WILL SUPPORT 15
TO 25 KTS ON THE NORTH END OF THE LAKE INTO EARLY THIS EVENING.
MEANWHILE LOW PRESSURE OVER EASTERN COLORADO WILL MOVE NORTHEAST
ACROSS THE PLAINS TONIGHT AND SUNDAY REACHING THE UPPER PENINSULA
OF MICHIGAN BY MONDAY MORNING. THE GRADIENT WILL TIGHTEN AS THIS
LOW APPROACHES. BUT WITH STRONG WARM AIR SPREADING OVER THE COOLER
WATER...CONFIDENCE REGARDING JUST HOW STRONG THE WINDS WILL BECOME
OVER THE OPEN WATERS REMAINS LOW. ITS POSSIBLE THAT THE GRADIENT
MAY BECOME TIGHT ENOUGH FOR LOW END GALES EVEN WITH A LACK OF
MIXING. IF THIS WERE TO OCCUR...THE BEST TIMING WOULD LIKELY BE
SUNDAY EVENING. FOR NOW...HAVE MAINTAINED WINDS TO 30KTS. AND HAVE
ALSO MAINTAINED THE GALE WATCH FOR THE INDIANA/ILLINOIS NEARSHORE
WATERS WITH STRONG WINDS/GUSTS EXPECTED OVER LAND...SPREADING
ACROSS THE NEARSHORE WATERS. AS THE LOW ELONGATES AND LIFTS
NORTHEAST...WINDS WILL SHIFT WESTERLY BY MIDDAY MONDAY AND THEN
NORTHWEST BY MONDAY EVENING. THE GRADIENT APPEARS STRONG ENOUGH
THAT A SHORT PERIOD OF GALES WILL BE POSSIBLE ACROSS NORTHERN LAKE
MICHIGAN MONDAY AFTERNOON. HIGH PRESSURE SPREADS ACROSS THE LAKES
REGION LATE MONDAY NIGHT...CROSSING THE LAKE TUESDAY AFTERNOON
WITH A PERIOD OF LIGHT WINDS EXPECTED...ALONG WITH LAKE BREEZES ON
THE ILLINOIS/INDIANA NEARSHORE WATERS. LOW PRESSURE MOVING ACROSS
THE PLAINS TUESDAY NIGHT INTO WEDNESDAY WILL QUICKLY TIGHTEN A
SOUTHERLY GRADIENT TUESDAY NIGHT INTO WEDNESDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...6 AM SUNDAY TO NOON SUNDAY.
GALE WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...NOON
SUNDAY TO 10 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1210 AM CDT SUN APR 15 2012
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
STRONG-SEVERE THUNDERSTORMS WILL BE IN THE VICINITY OF KSLN AND
MOVING INTO KHUT/KICT SHORTLY AFTER START OF FORECAST. DRYLINE WILL
BE MOVING ACROSS MOST OF THE AREA THROUGH DAYBREAK. IFR
CONDITIONS...HAIL AND 50KT+ WINDS WILL BE BRIEFLY POSSIBLE WITH
ANY OF THE SEVERE STORMS. VERY GUSTY SOUTHWEST WINDS ANTICIPATED
BEHIND DRYLINE. SOME VFR CLOUDS IN WRAP AROUND POSSIBLE AT
KRSL/KSLN SUN AFTERNOON. -HOWERTON
&&
.PREV DISCUSSION... /ISSUED 632 PM CDT SAT APR 14 2012/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
CONVECTIVE TRENDS WILL BE THE MAIN ISSUE...WITH STRONG-SEVERE
THUNDERSTORMS IN THE VICINITY OF KSLN AND NOT TOO FAR FROM KHUT AT
START OF FORECAST. WILL CONTINUE WITH VCTS AT KRSL/KICT...AS
TIMING OF STORMS IS A BIT UNCLEAR AND IMPACT IF INCLUDED WOULD BE
SIGNIFICANT. 00-06 UTC WILL LIKELY BE THE MOST ACTIVE AT
KHUT/KICT/KSLN. WITH DRYLINE REMAINING WELL WEST OF THE
AREA...STORMS MAY CONTINUE TO REGENERATE THROUGHOUT THE EVENING. IFR
CONDITIONS...LARGE HAIL AND 50KT+ WINDS WILL BE BRIEFLY POSSIBLE
WITH ANY OF THE SEVERE STORMS. ANTICIPATE DRYLINE SHOULD ENTER THE
AREA AROUND 0700 UTC AND NOT EXIT SOUTHEAST KS UNTIL AFTER 1200
UTC. VERY GUSTY SOUTHWEST WINDS ANTICIPATED BEHIND DRYLINE.
-HOWERTON
PREV DISCUSSION... /ISSUED 333 PM CDT SAT APR 14 2012/
DISCUSSION...
MAIN FORECAST CONCERN: THIS EVENING AND TONIGHT WILL BE THE MOST
CONCERNING PORTION OF THE FORECAST WITH AMPLIFIED SEVERE THREAT FOR
THE COUNTY WARNING AREA. OTHERWISE...THE ISSUES INCLUDE THE POPS FOR
SUNDAY INTO MONDAY WITH THE LOW PUSHING OUT OF THE AREA AND ANY
POTENTIAL WRAP AROUND.
TONIGHT:
DRYLINE WILL BE EVEN SLOWER TO MOVE ACROSS THE AREA...MOST LIKELY
LATER TONIGHT. HOWEVER CONSIDERABLE INSTABILITY/SHEAR ALREADY IN
PLACE...WITH ISOLATED SEVERE STORMS JUST WEST OF AREA AT THIS
TIME. BELIEVE CONDITIONS ARE SUFFICIENT FOR THESE TO CONTINUE AS
THEY MOVE EAST...WITH WITH SOUTHERN SECTIONS LIKELY HAVING BETTER
INSTABILITY THROUGH SUNSET. GIVEN HODOGRAPHS...SUPERCELLS WITH
TORNADIC POTENTIAL WILL EXIST...WELL INTO THE EVENING. DRYLINE
SHOULD SWEEP ACROSS THE AREA DURING MIDDLE OF THE NIGHT.
TEMPERATURES WILL LIKELY REMAIN QUASI STEADY AHEAD OF THE DRYLINE
GIVEN THE LOW LEVEL MOISTURE AND GRADIENT WINDS. -HOWERTON
SUNDAY:
BETTER ALIGNMENT OF THE SURFACE AND UPPER LEVEL TROUGH WHICH WILL
CONTINUE TO PUSH OFF TO THE NORTHEAST ON SUNDAY. A COLD FRONT WITH
THIS SYSTEM IS ANTICIPATED TO SLIDE THROUGH CENTRAL KANSAS FIRST
THEN THROUGH THE REST OF SOUTH CENTRAL AND SOUTHEAST KANSAS THROUGH
THE DAY. THERE IS CONCERN OF STRONG WINDS AHEAD OF AND BEHIND
FRONTAL PASSAGE WITH SUSTAINED SPEEDS JUST SHY OF WIND ADVISORY
CRITERIA BASED ON CURRENT TRENDS. DECIDED AGAINST ISSUING ANY WIND
HEADLINES RIGHT NOW...BUT THE NEXT FORECAST MAY DECIDE TO GO FORWARD
WITH IT. THERE MAY BE LINGERING SHOWERS AND THUNDERSTORMS WITH THE
EXITING LOW WHICH WILL CONTINUE INTO THE MORNING AND AFTERNOON HOURS
IN SOUTHEAST KANSAS...BUT SEVERE POTENTIAL DOES NOT APPEAR TO BE
HIGH WITH THE MAJOR SOURCES OF INSTABILITY DIMINISHING. DID DECREASE
THE POPS SUNDAY EVENING AND NIGHT AS THE PROGRESSION OF THE SYSTEM
APPEARS TO BE MUCH QUICKER THAN PREVIOUSLY ANTICIPATED.
MONDAY:
A SECONDARY WAVE APPEARS TO BE ASSOCIATED WITH THE UPPER LEVEL AT
500MB THAT WILL SLIDE THROUGH ON MONDAY...YET HIGH PRESSURE AT THE
SURFACE TO 850MB. THERE MAY BE A FEW SHOWERS ASSOCIATED WITH THIS
WAVE PARTICULARLY IN CENTRAL AND POTENTIALLY SOUTH CENTRAL KANSAS.
PV DOES INDICATE A PIECE ENERGY MOVING WITH THIS SYSTEM...HOWEVER
MODELS VARY IN LOCATION AND DEVELOPMENT OF ANY PRECIPITATION. THUS
DECIDED TO WAIT ON CHANCES FOR NOW.
TUESDAY TO SATURDAY:
THE NEXT TROUGH WILL START TO DO MOST OF ITS DEVELOPMENT WHEN IT
MOVES OVER THE ROCKIES FOR WEDNESDAY TO THURSDAY...HOWEVER 850MB
INDICATES THE MAIN SYSTEM TO STAY IN THE NORTHERN PLAINS. AT THE
SURFACE...THERE IS INDICATION OF THE LOW PASSING THROUGH ON THURSDAY
WITH SOME ASSOCIATED INSTABILITY FOR THE AFTERNOON AND EVENING
HOURS. THUS KEPT THUNDERSTORM CHANCES IN FOR THIS TIME FRAME.
MOVEMENT OF THIS NEXT TROUGH IN THIS EXTENDED IS A BIT QUESTIONABLE
WITH MODEL VARIATION IN THE TIMING...DEPTH AND EXACT LOCATION. THIS
COULD CHANGE ANY POTENTIAL IN POPS. TEMPERATURES ARE ON TRACK TO
CLIMB TO NEAR TO ABOVE NORMAL WITH THURSDAY LOOKING TO BE THE
WARMEST DAY OF THE WEEK WITH THE GOOD SURGE OF WARM AIR ADVECTION
OUT AHEAD OF THE NEXT SYSTEM.
VP
PREV DISCUSSION... /ISSUED 242 PM CDT SAT APR 14 2012/
UPDATE...
12 UTC AND LATER RUC MODEL RUNS SUGGEST DRYLINE WILL BE EVEN SLOWER
TO MOVE ACROSS THE AREA...MOST LIKELY LATER TONIGHT. THIS WILL
IMPACT SEVERE THREAT ACROSS THE AREA. AT THIS TIME...BEST
INSTABILITY/WEAKEST CAP IS OCCURRING ACROSS WESTERN SECTIONS OF
CENTRAL KS WITH CAP HOLDING ON ACROSS MOST OF SOUTH CENTRAL/
SOUTHEAST KS. GIVEN LACK OF SURFACE BOUNDARY AND EXTENSIVE CLOUDS
SO FAR...MAY BE TOUGH TO BREAK CAP ACROSS SOUTH CENTRAL KS THIS
AFTERNOON. HOWEVER A FEW SMALL BREAKS IN CLOUDS ARE EVIDENT IN
VISIBILITY SATELLITE SOUTH/WEST OF ICT. IF STORMS CAN DEVELOP IN
THIS AREA...CLEARLY ENVIRONMENT WOULD BE CONDUCIVE FOR STRONG/
SEVERE STORMS. BIGGEST THREAT TONIGHT IS ROUGHLY ALONG AND SOUTH
OF HIGHWAY 400 ACROSS SOUTH CENTRAL KS...EAST TO HIGHWAY 99 IN
THE 00-04 UTC TIME FRAME...WITH INCREASING ELEVATED STORM RISK
03-06 UTC ACROSS CENTRAL KS EAST OF I-135. -HOWERTON
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
CONVECTIVE TRENDS WILL BE THE MAIN ISSUE...WITH STRONG-SEVERE
THUNDERSTORMS IN THE VICINITY OF KRSL AT START. ISOLATED-SCATTERED
RAIN SHOWERS/THUNDERSTORMS WILL BE POSSIBLE DURING THE AFTERNOON AT
KSLN/KHUT/KICT...BUT EXPECT COVERAGE/INTENSITY TO RAMP UP TOWARDS
0000 UTC...WITH 0000 UTC-06 UTC THE MOST ACTIVE AT KHUT/KICT/KSLN.
IFR CONDITIONS...LARGE HAIL AND 50KT+ WINDS WILL BE BRIEFLY
POSSIBLE WITH ANY OF THE SEVERE STORMS. DRYLINE SHOULD ENTER THE
AREA LATER TONIGHT...BRINGING END TO PRECIPITATION AND LOSS OF
CEILING. GUSTY SOUTHWEST WINDS ANTICIPATED BEHIND DRYLINE.
-HOWERTON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 44 66 45 71 / 0 10 10 0
HUTCHINSON 44 66 42 70 / 0 10 10 0
NEWTON 45 65 42 70 / 10 10 10 0
ELDORADO 45 67 43 71 / 10 10 10 0
WINFIELD-KWLD 45 69 46 72 / 10 10 0 0
RUSSELL 39 64 41 71 / 10 20 10 10
GREAT BEND 39 64 42 70 / 10 20 10 0
SALINA 43 65 41 70 / 10 20 10 10
MCPHERSON 44 65 41 70 / 10 10 10 10
COFFEYVILLE 47 68 44 71 / 10 10 10 0
CHANUTE 47 67 42 70 / 10 10 10 0
IOLA 47 66 42 69 / 10 10 10 0
PARSONS-KPPF 47 68 44 70 / 10 10 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1256 AM EDT SUN APR 15 2012
.SYNOPSIS...
ISSUED AT 412 PM EDT SAT APR 14 2012
A WARM FRONT WILL BRING A PERIOD OF THUNDERSTORMS WITH LOCALLY
HEAVY RAINFALL LATE TONIGHT INTO MID MORNING SUNDAY. THE COLD
FRONT MONDAY NIGHT WILL BRING AN PERIOD OF THUNDERSTORMS WITH
GUSTY WINDS WITH IT. NO MONDAY IT WILL BECOME VERY WINDY WITH
FALLING TEMPERATURES DURING THE DAY AS WELL AS SCATTERED SHOWERS.
FROST AND FREEZING TEMPERATURES ARE EXPECTED BY TUESDAY MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 412 PM EDT SAT APR 14 2012
LITTLE CHANGE IN THINKING FROM MY LATE MORNING DISCUSSION. A
PERIOD OF THUNDERSTORMS (NOT SEVERE) WITH THE WARM FRONT
TONIGHT...DRY MIDDAY SUNDAY UNTIL MID EVENING...THEN THE FRONTAL
RAIN BAND WITH GUSTY WINDS LATE EVENING SUNDAY INTO THE EARLY
MORNING HOURS OF MONDAY.
TONIGHT THE LOW LEVEL JET BIFURCATES WITH PART OF IT GOING INTO OHIO
AND THE REST OF IT HEADED TOWARD MN/WI. THAT ALSO IS NOT CONDUCIVE
FOR CONVECTION HERE. IT IS NOT UNTIL MID MORNING SUNDAY THE
SOUTHERN BRANCH OF THE BIFURCATED LOW LEVEL JET EVEN SHOWS A SIGN OF
GETTING INTO THE I-94 REGION AND BY THEN IT IS WEAKENING. THE
PRIMARY CORE STAYS OVER WI/MI/IA THROUGH THE DAY AND SLOWLY
DEVELOPS NORTHWARD NOT EASTWARD. SO I EXPECT A BAND OF
THUNDERSTORMS TO HEAD NORTH THROUGH LOWER MICHIGAN MID MORNING BUT
WILL LIKELY NOT BE SEVERE (NOT SURFACE BASED). THE HRRR RUC FROM
THE 16Z MODEL RUN SHOWS THIS NICELY. SO MOST OF THE RAIN FROM THE
WARM FRONTAL RAIN BAND WILL BE BETWEEN MIDNIGHT AND 10 AM MONDAY.
THE MODELS AND SOUNDING SHOW NO SURFACE BASED CAPE AND ONLY 500 TO
1000 J/KG OF MOST UNSTABLE CAPE (FROM 800 MB LAYER). THUS I DO NOT
SEE MUCH OF SEVERE THREAT TONIGHT WITH THESE STORMS. JUST LOCALLY
HEAVY RAINFALL.
ON SUNDAY THE WARM FRONT LIFTS NORTH OF THE CWA AND SO WILL THE
ASSOCIATED CONVECTION. THERE IS SURFACE BASED INSTABILITY SUNDAY BUT
NO FOCUS SO I DO NOT BELIEVE WE WILL BE SEEING MUCH IF ANY
CONVECTION IN THE GRR CWA DURING THE AFTERNOON. IF THE SUN REALLY
CAME OUT TEMPERATURES COULD REACH 80 SOUTH OF INTERSTATE 96.
SUNDAY NIGHT WILL BE OUR CONVECTIVE "SHOW" IF ONE COULD CALL IT
THAT. IT TAKES UNTIL 2 AM FOR THE LOW LEVEL JET CORE TO GET TO
I-31. WHILE FORECAST SHOWS 1500-2000 J/KG OF SURFACE BASED CAPE
OVER WI SUN AFTERNOON BY THE TIME THIS REACHES LOWER MICHIGAN
AFTER MIDNIGHT IT IS LESS THE 500 J/KG. ON THE OTHER HAND WE DO
STILL HAVE SURFACE BASED CAPE SO AND A 60 TO 70 KNOT LOW LEVEL
JET. GIVEN THE LOW CAPE VALUE LARGE HAIL SEEMS OUT OF THE
QUESTION. MOSTLY GUSTY WINDS BUT WITH WEAK CAPE ONE HAS TO EVEN
WONDER ABOUT THAT. SO I AM NOT EXPECTING A MAJOR SEVERE OUTBREAK
IN OUR CWA FROM THIS EVENT. JUST ISOLATED SEVERE STORMS POSSIBLE
AFTER MIDNIGHT. SPC`S OUTLOOK FOR SUNDAY NIGHT INTO MONDAY AGREES
WITH THIS WITH A 15 PCT CHANCE OVER OUR NW CWA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 412 PM EDT SAT APR 14 2012
TRENDED POPS LOWER FOR MONDAY AND ALSO TRENDED COOLER FOR MONDAY
NIGHT AND TUESDAY NIGHT. MODEL TRENDS ARE MORE PROGRESSIVE WITH
MOVING THE SURFACE LOW OUT OF THE AREA ON MONDAY. THIS SHOULD
RESULT IN QUICKER CLEARING MONDAY NIGHT...AND REMAINING MOSTLY CLEAR
TUESDAY NIGHT WITH HIGH PRESSURE OVER MI. FROST AND FREEZING TEMPS
WILL BE A CONCERN UNDER THIS SCENARIO...ESPECIALLY TUESDAY NIGHT AS
WINDS SHOULD BE LIGHTER.
NEXT CHANCE OF PCPN SHOULD HOLD OFF UNTIL WED AFTERNOON OR EVENING
AS A NORTHERN STREAM WAVE BRINGS A COLD FRONT LATE WED NIGHT OR
EARLY THU. THE FRONT THEN STALLS TO OUR SOUTH WITH OVER-RUNNING
PCPN LINGERING. IT APPEARS THE CWA WILL BE ON THE NORTHERN FRINGE
OF THIS PCPN...SO I HAVE HIGHER POPS IN THE SOUTHERN CWA...AND LOWER
POPS NORTH. THE EURO HOLDS ON TO PCPN RIGHT INTO SAT...BUT THE GFS
GOES DRY. HAVE FAVORED THE DRIER GFS AS THE PATTERN LOOKS MORE
PROGRESSIVE THAN WHAT THE EURO SUGGESTS. TEMPS WILL REMAIN COOL WITH
NE LOW LEVEL FLOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1256 AM EDT SUN APR 15 2012
MAIN CONCERNS WITH THE 06Z TAFS WILL BE CONVECTIVE TRENDS AND
ASSOCIATED CONDITIONS THROUGH THE PERIOD...AND WIND GUST
POTENTIAL.
COMPLEX OF STORMS OVER NRN IL/SRN WI/ERN IA AS OF 05Z IS EXPECTED
TO CONTINUE MOVING E/NE TOWARD THE AREA. EXTRAPOLATION OF THESE
STORMS PUTS THEM INTO THE WRN FOUR TERMINALS AROUND 07Z OR
SO...AND THE KJXN AND KLAN AROUND 08Z OR SO. WE ARE EXPECTING
MAINLY MVFR CONDITIONS WITH SOME TEMPO IFR DUE TO VSBY AND SOME
CIGS. THESE STORMS WILL THEN GRADUALLY LIFT TO THE NORTH AFTER
DAYBREAK AS A WARM FRONT MOVES NORTH. SHOWERS AND STORMS SHOULD
CLEAR THE TERMINALS BY 15Z.
ONCE THE STORMS MOVE NORTH...THE AREA WILL GET INTO THE WARM AIR.
WE WILL SEE SRLY WINDS INCREASE WITH GUSTS 25 TO 30 KNOTS LIKELY.
THESE WINDS WILL CONTINUE ALL DAY AND INTO THE EVENING HOURS AHEAD
OF THE INCOMING FRONT. LOW CLOUDS WILL SCOUR OUT. WE CAN NOT RULE
OUT A POP UP SHOWER OR STORM DURING THE DAY...BUT CHCS ARE TOO LOW
TO INCLUDE IN THE FCST AT THIS TIME. BETTER CHC FOR STORMS WILL
COME IN BEGINNING AROUND RIGHT AROUND THE END OF THIS FCST PERIOD
AROUND 06Z MON.
&&
.MARINE...
ISSUED AT 1023 PM EDT SAT APR 14 2012
WE DECIDED TO BUMP UP THE TIMING ON THE SMALL CRAFT ADVISORY TO
AROUND 06Z TONIGHT. WINDS ALONG THE LAKESHORE AT THE COASTAL SITES
ARE GENERALLY RUNNING 10 TO 15 KNOTS...WITH BIG SABLE POINT COMING
IN AROUND 20 KNOTS ALREADY. LOW LEVEL WINDS WILL BE
INCREASING...HOWEVER STABLE ENVIRONMENT OVER THE LAKE WILL LIMIT
THE WIND SPEED SOME AT THE SFC. WE STILL THINK THAT THERE WILL BE
ENOUGH OF AN INCREASE TO JUSTIFY THE ADVISORY...AND IT VERY WELL
COULD BEGIN BEFORE 12Z SUN.
&&
.HYDROLOGY...
ISSUED AT 412 PM EDT SAT APR 14 2012
LOCALLY HEAVY RAINFALL IS POSSIBLE TONIGHT WITH THE WARM FRONT
PRECIPITATION BAND MOVING NORTHWARD THROUGH SOUTHWEST LOWER
MICHIGAN. AT THIS POINT THROUGH WE DO NOT SEE A LARGE SCALE GENERAL
HEAVY RAINFALL. MOST LOCATIONS TONIGHT SHOULD GET AROUND A HALF
INCH. THE COLD FRONT RAIN BAND SHOULD NOT BE AS HEAVY...GENERALLY
AROUND A QUARTER INCH. THIS SHOULD NOT CAUSE TO MANY PROBLEMS FOR
OUR RIVERS BUT COULD LOCALLY CAUSE ISSUES ON SMALLER STREAMS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...JK
AVIATION...NJJ
HYDROLOGY...WDM
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1234 AM CDT SUN APR 15 2012
.AVIATION...06Z KGRI TAF. A LINE OF THUNDERSTORMS ABOUT TO MOVE
INTO THE TAF AREA. AFTER THIS LINE OF STORMS MOVES THRU LOOKS LIKE
THE THUNDERSTORM SHOW IS DONE AT KGRI FOR THE NIGHT. VFR
CONDITIONS EXPECTED THROUGH THE NIGHT...BUT WOULD NOT BE SHOCKED
TO SEE A STRAY SHOWER WITH SOME MVFR CEILINGS PASS THRU
PERIODICALLY THRU THE PERIOD. NO MENTION AT THIS POINT SINCE
CHANCES LOW. BIGGEST CONCERN WILL THE VERY STRONG NORTHWEST WINDS
TODAY. A VERY STRONG PRESSURE GRADIENT WILL PRODUCE GUSTS TO 35KTS
AT TIMES THIS AFTERNOON.
&&
PREV DISCUSSION... /ISSUED 420 PM CDT SAT APR 14 2012/
SHORT TERM...THROUGH SUNDAY AFTERNOON. THE OBVIOUS CONCERN IS THE
EVOLUTION OF SEVERE CONVECTION OVER AT LEAST THE NEXT 6-8 HOURS.
IN SHORT...THE FIRST ROUND OF STRONG-SEVERE CONVECTION IS IN THE
PROCESS OF EXITING FAR EASTERN PORTIONS OF THE CWA...ESSENTIALLY
BRINGING ROUND 1 TO A CLOSE. THESE STORMS RESULTED IN AT LEAST 3
UNCONFIRMED BRIEF TORNADOES NEAR AND SOUTH OF THE STATE
LINE...ALONG WITH SOME LOCALLY HEAVY RAIN IN EXCESS OF 2 INCHES.
THE CONCERN NOW SHIFTS BACK TO THE FAR WESTERN-SOUTHWESTERN
CWA...AS CLEARING SKIES ARE RAPIDLY DESTABILIZING AREAS CLOSER TO
THE SURFACE DRYLINE FROM SOUTHWEST NEB DOWN ACROSS WESTERN KS. AS
A RESULT...WANT TO EMPHASIZE THAT THIS EVENT IS FAR FROM BEING
OVER.
PARAMETERS FOR ADDITIONAL DEVELOPMENT ARE VERY FAVORABLE FOR
HIGH-END SEVERE...AS THE 110+KT UPPER LEVEL JET STREAK CURRENTLY
MAKING ITS WAY INTO FAR WESTERN KS OVERSPREADS THE AREA.
SUPERCELLS ARE LIKELY WITH 0-6KM BULK SHEAR OF AT LEAST 50KT...AND
WITH LOW LEVEL 0-1KM BULK SHEAR OF 30-40 KT. 0-1KM STORM RELATIVE
HELICITY IS QUITE IMPRESSIVE AS WELL...WITH 300-400+ M2/S2 ACROSS
MUCH OF THE CWA...WHICH COULD ONLY INCREASE INTO THE EVENING HOURS
AS THE LOW LEVEL JET STRENGTHENS. FOLLOWING CONVECTIVE REFLECTIVITY
PROGS FROM LATEST HRRR...ALONG WITH 12Z RUNS OF 4KM WRF-NMM...ALONG
WITH LATEST RUC FIELDS...SIGNIFICANT SURFACE-BASED INSTABILITY
WILL CONTINUE SURGING NORTHEAST INTO THE CWA THROUGH THE NEXT
SEVERAL HOURS WITH LOW LEVEL CAPE IN EXCESS OF 2000 J/KG
PERSISTING WELL INTO THE EVENING. HRRR SUGGESTS A COMBINATION OF
DISCRETE SUPERCELLS AND QUASI LINEAR STORM MODES WILL CONTINUE
WELL INTO THE EVENING...WITH SOUTHERN AND WESTERN PORTIONS OF THE
CWA LIKELY MOST UNDER THE GUN. ALTHOUGH HYDRO ISSUES SEEM TO BE
MINIMAL SO FAR...ANOTHER 1-2 INCHES OF RAIN ACROSS ROUGHLY THE
SOUTHEAST 1/3 OF THE CWA ON TOP OF WHAT FELL EARLIER COULD LEAD TO
SOME ISSUES.
SO FAR...WIND ADVISORY IN EFFECT FOR KS ZONES THROUGH 00Z IS NOT
PANNING OUT VERY WELL WITH CONVECTIVE ACTIVITY INTERFERING...AND
ALTHOUGH NEITHER AN IMMEDIATE CANCELLATION OR AN EXTENSION IS NOT
PLANNED AT THIS TIME...WILL PROBABLY SEE STRONGER SOUTHERLY WINDS
ACTUALLY PICK UP OVERNIGHT AS THE SURFACE LOW DEEPENS TO AROUND
987MB IN THE NORTHEAST CO/SOUTHWEST NEB AREA. SPEAKING OF WIND...A
GOOD CHUNK OF THE CWA WILL ALMOST CERTAINLY NEED AN ADVISORY
DURING THE DAY SUNDAY...AS STRONG WINDS INITIALLY ARE FROM THE
SOUTH...BUT THEN FROM THE WEST AND NORTHWEST BEHIND THE COLD
FRONT. INSERTED A STRONG WIND MENTION INTO THE GRIDS AND HAZARDOUS
WEATHER OUTLOOK...BUT WITH EVERYTHING ELSE GOING ON TODAY WILL
DEFER TO MIDNIGHT SHIFT TO PULL THE TRIGGER ON THE NEXT WIND
HEADLINE...WHICH WILL UNDOUBTEDLY BE MORE ROBUST THAN THE CURRENT
ONE.
AS FOR STORM CHANCES LATE TONIGHT...ONLY HAVE 20-30 PERCENT
CHANCES POST-06Z...AND ALTHOUGH THE VAST MAJORITY OF THE CWA
SHOULD BE FREE OF SEVERE WEATHER BY THEN...COULD FORESEE A
MARGINALLY SEVERE STORMS HANGING ON IN NORTHERN ZONES LATE INTO
THE NIGHT. SHOULD BE A LULL IN PRECIPITATION ACROSS MUCH OF THE
CWA LATE TONIGHT INTO SUNDAY MORNING AS THE SYNOPTIC DRY SLOT
SURGES IN...BUT RAIN SHOWERS WILL GRADUALLY SPREAD INTO THE CWA
FROM WEST TO EAST WRAPPING AROUND THE DEPARTING LOW. THE
COMBINATION OF ANY RAIN SHOWERS WITH THE STRONG WINDS WILL MAKE
THE FORECAST HIGHS IN THE MID 50S TO MID 60S FEEL COLDER THAN IT
MAY SOUND.
LONG TERM...SUNDAY EVENING THROUGH NEXT SATURDAY. OVERALL FEW
NOTABLE CHANGES MADE TO PREVIOUS FORECAST...WITH FORECAST BASED ON
A GENERAL BLEND OF THE 12Z ECMWF/GFS.
STARTING OFF RIGHT AWAY SUNDAY EVENING...A WIND ADVISORY MAY
CONTINUE FOR A FEW MORE HOURS ESPECIALLY IN NORTHEAST AREAS...BUT
LIKELY NOT BEYOND 03Z AS THE STRONG SURFACE LOW PULLS GRADUALLY
AWAY ACROSS SOUTHERN MN. LINGERED A SLIGHT CHANCE OF LIGHT SHOWERS
INTO THE EVENING HOURS MAINLY ACROSS THE NORTHEAST...BUT DRY AFTER
MIDNIGHT. HEADING INTO MONDAY...LEFT THE MORNING DRY BUT HAVE
20-30 PERCENT CHANCES FOR SHOWERS IN THE AFTERNOON AS A TRAILING
SHORTWAVE TRACKS OUT OF SOUTHERN SD INTO NORTHERN NEB. NEXT SLIGHT
CHANCE FOR SHOWERS ARRIVES IN NORTHEAST COUNTIES FOR TUESDAY NIGHT
AS THE NEXT QUICK MOVING WAVE PASSES BY IN QUASI-ZONAL FLOW ALOFT.
A FAIRLY ACTIVE UPPER PATTERN CONTINUES INTO THE LATTER PART OF
THE WEEK...AND MAINTAINED 20-30 PERCENT CHANCES FOR SHOWERS/STORMS
FROM THURS INTO THURS NIGHT AS THE NEXT WAVE CROSSES THE REGION.
AT THIS TIME...SEVERE WEATHER THREAT APPEARS LOW. BEYOND THURSDAY
NIGHT...MAINTAINED A DRY FORECAST THROUGH SATURDAY AS THERE ARE
SUGGESTIONS OF AT LEAST WEAK SHORTWAVE RIDGING BUILDING INTO THE
PLAINS.
TEMPERATURE WISE THROUGH THE EXTENDED...HAVE MOST DAYS IN THE
LOW-MID 70S FOR HIGHS...EXCEPT FOR COOLER UPPER 50S-LOW 60S ON
MONDAY. AS FOR OVERNIGHT LOWS...COULD EVENTUALLY NEED TO INSERT
SOME FROST WORDING FOR SUNDAY NIGHT AND/OR MONDAY NIGHT WITH LOWS
IN THE MID-UPPER 30S...ALTHOUGH BREEZES MAY REMAIN JUST STRONG
ENOUGH TO PRECLUDE MUCH DEVELOPMENT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
419 AM EDT SUN APR 15 2012
.SYNOPSIS...
A FEW SHOWERS AND EVEN THE RUMBLE OF THUNDER ARE POSSIBLE FROM
LATE THIS MORNING INTO THIS AFTERNOON AS A WARM FRONT MOVES
THROUGH THE AREA. WE WILL BE DRY TONIGHT INTO MOST OF MONDAY BUT
THE BIGGER STORY WILL BE THE WARM-UP. WE EXPECT HIGHS TO BE INTO
THE 80S MOST LOCATIONS MONDAY AFTERNOON. A COLD FRONT WILL BRING A
SHOT AT SHOWERS AND THUNDERSTORMS TOWARD MONDAY EVENING AND INTO
THE OVERNIGHT. BEHIND THE FRONT TEMPERATURES RETURN TO MORE
SEASONABLE LEVELS FOR MIDWEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
4 AM UPDATE...THE FORECAST IS IN VERY GOOD SHAPE AND NOT MUCH TO
CHANGE. AN AREA OF SHOWERS NOW OVER THE EASTERN PART OF THE CWA
WILL EXIT STAGE RIGHT PRIOR TO DAYBREAK WITH MOST OF THIS MORNING
ENDING UP DRY. WE WAIT THE ARRIVAL OF A WARM FRONT NOW OVER THE
OHIO VALLEY LATER TODAY. HI RES MODELS SUCH AS THE
ARW...NMM...NAM12 AND HRRR ARE ALL IN GOOD AGREEMENT WITH SOME
SCT. SHOWERS DEVELOPING OVER THE WESTERN AND CENTRAL PART OF OUR
CWA...MAINLY NORTH OF THE NY/PA LINE...BETWEEN 15Z AND 18Z. AS THE
WARM FRONT LIFTS NORTH...MAIN SHOT AT SHOWERS WILL TRACK NORTHEAST
THROUGH THE MOHAWK VALLEY LATER TODAY. BEST SHOT AT SHOWERS IN
NORTHERN PA LOOKS TO BE BRADFORD OR SUSQUEHANNA COUNTY...WITH
AGAIN HIGHEST POPS OVER NY. LEFT IN A SHOT AT ISOLATED THUNDER
TODAY BUT WITH A CAP EARLY THIS MORNING AND PLENTY OF CLOUDS
AROUND...INSTABILITY LOOKS TO BE LACKING TOO MUCH TO BE A REAL
CONCERN FOR MORE THAN A FEW RUMBLES. TOWARD LATE IN THE
DAY...FOCUS FOR SHOWERS WILL SHIFT NORTH WITH DRIER AIR BUILDING
IN FROM THE SOUTHWEST.
TONIGHT...DRYING TREND WILL CONTINUE AS WE GET INTO THE WARM
SECTOR AND PRONOUNCED DRYING OCCURS FROM NEAR THE SURFACE UP
THROUGH THE ENTIRE COLUMN. IT DOES APPEAR A FEW SHOWERS MAY
LINGER OR HANG UP OVER ONEIDA COUNTY BUT EVEN HERE WE DRY OUT
TOWARD OR SLIGHTLY AFTER MIDNIGHT AT THE LATEST. LIKE THE PREVIOUS
FORECASTER`S IDEA OF WARMER THAN GUIDANCE AND STAYED THE COURSE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
MONDAY...BREAK OUT THE SHORTS. SEE LITTLE TO CHANGE FROM OUR
FORECAST OF 80-86 ACROSS THE CWA. STILL EXPECTING MOST OF THE DAY
TO BE DRY WITH EXCELLENT AGREEMENT BETWEEN THE MODELS...INCLUDING
THE GFS/NAM/CANADIAN ALONG WITH THE HIGHER RESOLUTION MODELS. AS
A COLD FRONT APPROACHES POPS WILL INCREASE OVER THE WESTERN FINGER
LAKES INTO THE WESTERN MOHAWK VALLEY BETWEEN 21Z AND 0Z. AS FAR AS
SEVERE WEATHER POTENTIAL GOES...THE TIMING OF THE FRONT...IF
TOTALLY CORRECT AS IT STANDS NOW...MAY BE JUST A TAD TOO LATE FOR
PEAK HEATING AND THE BEST INSTABILITY. A GOOD EXAMPLE OF THIS IS
THE NAM BUFKIT SOUNDINGS FOR KSYR/KELM/KITH WHICH SHOW CAPES
AROUND 300 J/KG TOWARD EVENING...COMPARED TO KROC WHICH HAS CAPES
IN THE 700 J/KG RANGE. I LOVE THE DEPICTION FROM SPC WITH SLIGHT
RISK MAINLY ACROSS WNY...AND JUST GETTING INTO THE EXTREME WESTERN
PART OF OUR CWA...WITH SEE TEXT ELSEWHERE. THIS MATCHES UP VERY
WELL WITH THE POP FORECAST OUTLINED ABOVE THROUGH 0Z TUESDAY. WE
WILL HAVE TO WATCH THE TIMING VERY CAREFULLY BECAUSE IF THE FRONT
IS JUST A BIT FASTER...AND WE HAVE MORE INSTABILITY TO WORK
WITH...DAMAGING WINDS ARE A REAL THREAT. 0-6 KM BULK SHEAR VALUES
ON BOTH THE GFS AND NAM ARE 50-55 KTS...AND WE HAVE DRY AIR IN
BOTH THE LOW LEVELS (INVERTED V SOUNDING) AND MID-LEVELS.
MONDAY NIGHT...AS THE FRONT MOVES EAST BEST SHOT AT SOME THUNDER
AND SHOWERS WILL BE THROUGH 03Z...WITH MOISTURE AND INSTABILITY
DIMINISHING QUICKLY AS THE NIGHT WEARS ON. WITH THAT IN MIND
HIGHEST POPS WILL BE ROUGHLY NEAR I-81 AND POINTS WEST...WITH
CHANCES FOR MEASURABLE RAIN DROPPING OFF SHARPLY THE FARTHER
SOUTH AND EAST YOU GO.
TUESDAY...COOLER TEMPS FOR SURE BEHIND THE FRONT...BUT A SLOW
COOLING TREND AT 850 MB SHOULD ALLOW FOR A DECENT TEMP GRADIENT.
850S CLOSER TO +5C WILL ALLOW FOR A RANGE OF NEAR 70 OVER PIKE
COUNTY...TO 50S ACROSS THE NORTH WITH 850S SLIDING TO BELOW ZERO.
A SHORT WAVE WILL PASS TO THE NORTH OF OUR AREA BY AFTERNOON. THIS
SYSTEM WILL BE MOISTURE STARVED BUT THE SOUNDINGS ACROSS NORTHERN
ONEIDA COUNTY SHOW JUST ENOUGH MOISTURE TO WARRANT AN ISOLATED
SHOWER UP HERE FOR THE AFTERNOON HOURS. DRIER WEATHER BUILDS IN
TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
GNRLY ZONAL FLOW IS FCST IN THE MEDIUM RNG. HI PRES IS XPCTD TO BRING
FAIR WEATHER ON WED...WITH ANOTHER FNTL PSSG ON THU. LATE IN THE
PD...DEEPENING TROF MOVG INTO THE OH VLY MAY BRING UNSETTLED WX
FRI INTO SAT. NO SIG CHGS TO HPC GUIDANCE OTHER THAN BEING A BIT
MORE OPTIMISTIC ON CLD CVR TUE NGT INTO WED.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
WRM FNT OVER ERN OH AND NRN PA WILL LFT THRU THE REGION TODAY
BRINGING SCT SHWRS AND BRIEFLY LWRD CIGS. AIR BLO LIFT NEAR THE
SFC IS STILL FAIRLY DRY SO IFR CIGS AND VSBY ARE NOT LIKELY BEFORE
SUNRISE...BUT OCNL MVFR CIGS SEEM LIKELY...ESP OVER THE HILLTOPS
TERMINALS. LIGT WINDS THIS MRNG WILL BECOME SLY ON SUN BHD THE FNT
WITH INCRSD MIXING. ALSO...MIXING WILL HELP RAISE CIGS AND THEY
SHD REMAIN VFR THRU THE END OF THE TAF PD. ANY SHWRS WILL BE LGT
THIS MRNG.
.OUTLOOK...
SUN NGT...VFR.
MON...VFR...BUT A BAND OF MVFR CIGS/SHRA PSBL WITH FROPA LATE MON OR
MON EVNG.
MON NGT THRU WED NGT...VFR.
THU...SCT MVFR IN -SHRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...HEDEN
SHORT TERM...HEDEN
LONG TERM...
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
227 AM EDT SUN APR 15 2012
.SYNOPSIS...
A WARM FRONT WILL PASS THROUGH THE REGION TONIGHT INTO
SUNDAY...ACCOMPANIED BY A CHANCE OF SHOWERS AND PERHAPS
THUNDER...WHICH WILL SHIFT NORTHWARD WITH TIME. TEMPERATURES
WILL CONTINUE TO SURGE WARMER SUNDAY AND ESPECIALLY MONDAY...TO
THE TUNE OF 25 DEGREES OR SO ABOVE NORMAL. A COLD FRONT WILL PASS
MONDAY AFTERNOON INTO EVENING...WITH SHOWERS AND A CHANCE OF
THUNDER. TEMPERATURES RETURN TO MORE SEASONABLE LEVELS FOR
MIDWEEK.
&&
.NEAR TERM /THROUGH TODAY/...
1245 AM UPDATE...MINOR UPDATE. INITIALLY DESPITE DECENT RADAR
RETURNS IN SOUTHERN AND CENTRAL NY...WE WERE NOT GETTING PRECIP AT
THE GROUND DUE TO VERY DRY BOUNDARY LAYER CONDITIONS. WITH A FEW
OBS NOW REPORTING VERY LIGHT RAIN...ADDED ISOLATED SHOWERS TO
THESE AREAS OVERNIGHT. THE PREVIOUS AFD IS BELOW...
1010 PM UPDATE... AS DISCUSSED IN THE PREVIOUS
UPDATE...SHOWERS EXITING THE OHIO VLY CONTINUE TO MOVE ACROSS
ACROSS SOUTHWESTERN PA THIS EVENING. CONSIDERING THAT THE LOW-
LEVEL JET IS EXPECTED TO VEER TOWARDS A WESTERLY DIRECTION
OVERNIGHT...CURRENT THINKING IS THAT MUCH OF THE FORECAST AREA
WILL NOT BE IMPACTED BY THIS FEATURE. AS A RESULT...HAVE TRIMMED
POPS EVEN FURTHER WITH THE LATEST UPDATE. CLOSER TO HOME...LATEST
RADAR TRENDS STILL SHOWING ISOLATED LIGHT SHOWER ACTIVITY MOVING
THROUGH THE TWIN TIERS AND NORTHEAST PA...HOWEVER WITH DEWPOINT
DEPRESSIONS STILL REMAINING ANYWHERE BETWEEN 10-20
DEGREES...EXPECT NOTHING MORE THAN A SPRINKLE OR LGT SHOWER AT
BEST. IN GENERAL...HAVE MAINTAINED SLGT CHC TO CHC MENTION FROM
THE TWIN TIERS SOUTH. ASIDE FROM MINOR TEMP/DEWPOINT
ADJUSTMENTS...NO OTHER CHANGES NEEDED AT THIS TIME.
750 PM UPDATE...AS STATED IN THE PREVIOUS NEAR TERM
DISCUSSION...CURRENT ACTIVITY MOVING OVER THE FORECAST AREA IS
HAVING LITTLE IMPACT AS DEWPOINT DEPRESSIONS REMAIN ANYWHERE
BETWEEN 20-25 DEGREES EARLY THIS EVENING. AS THIS INITIAL SHIELD
EXITS STAGE RIGHT...ATTENTION WILL THEN SHIFT TO NEXT AREA OF
PRECIP NOW ENTERING WESTERN PA FROM THE OHIO VLY. QUICK LOOK AT
REGIONAL RADAR MOSAIC SHOWS THIS ACTIVITY MOVING EAST THIS EVENING
IN A DUE EASTERLY MOTION...SUGGESTING MUCH OF THIS ACTIVITY WILL
REMAIN SOUTH OF THE NY/PA STATE LINE..AND POSSIBLY EVEN THE ENTIRE
CWA. LATEST HRRR HIGH RES SIMULATED REFLECTIVITY ALONG WITH THE
LATEST RUC QPF FCST SUPPORT THIS LINE OF THINKING AS THE LOW-LEVEL
JET VEERS AND BECOMES NEARLY WESTERLY OVERNIGHT. BASED ON
THIS...FEEL LITTLE IF ANY PRECIP WILL OCCUR FROM THE FINGER LAKES
NORTH...AND WE HAVE TRIMMED POPS ACROSS THESE AREAS ACCORDINGLY.
WE MAY HAVE TO CONTINUE TO TRIMMING POPS FROM NORTH TO SOUTH WITH
THE NEXT UPDATE BASED ON CURRENT TRAJECTORIES BUT WILL CONTINUE TO
MONITOR TRENDS BEFORE MAKING ANY WHOLESALE CHANGES. ASIDE FROM
THAT...JUST SOME MINOR COSMETIC CHANGES TO TEMPS AND DEWPOINTS.
415 PM UPDATE...DESPITE BUSY LOOKING RADAR WITH INCOMING
SHOWERS...VERY DRY LOW LEVELS ARE MAKING THE TOP DOWN MOISTENING
PROCESS GRADUAL...WITH DEW POINT DEPRESSIONS OF ROUGHLY 30 DEGREES
WEST TO ALMOST 40 DEGREES EAST. ONLY EXPECTING SPRINKLES TO
ENCROACH LATE AFTERNOON TO EARLY EVENING...BEFORE 850MB JET CAN
BRING IN ENOUGH MOISTURE FOR MORE SIGNIFICANT RAIN CHANCES. LATEST
MODEL RUNS ARE AGREEING THAT AN EMBEDDED NORTHERN STREAM SHORTWAVE
WILL DROP WNW TO ENE THROUGH THE AREA 01Z-04Z. MODELS DISAGREE
DETAILS OF SHOWER ACTIVITY...BUT CONSENSUS HAS DEFINITELY SHIFTED
TOWARDS FAVORING SOUTHWESTERN ZONES...BECAUSE OF POSITIONING OF
WARM FRONT...AND EFFECT OF DRY AIR FARTHER NORTH AND EAST.
REGARDLESS...WAVE HEADS OUT SHORTLY AFTER MIDNIGHT FOR A RELATIVE
LULL IN ACTIVITY DURING THE PREDAWN HOURS. POPS HAVE BEEN ADJUSTED
ACCORDINGLY. ALSO...WITH AMOUNT OF CLOUD COVER AND GOOD MIXING...I
WENT WELL ABOVE MAV GUIDANCE AND SLIGHTLY ABOVE MET GUIDANCE FOR
LOW TEMPERATURES.
SUNDAY IS NOT LOOKING VERY FAVORABLE FOR CONVECTION...COMPARED TO
EARLIER MODEL RUNS. SHALLOW WARM FRONT...WITH SURGING HEIGHTS
ALOFT YET DELAYED RESPONSE NEAR THE SURFACE...WILL ALLOW FOR AN
INHIBITIVE CAP TO DEVELOP ABOVE LOWERING CLOUD COVER LATE TONIGHT
INTO SUNDAY MORNING. CLOUD COVER WILL LIMIT AMOUNT OF WARMING IN
THE MORNING. BY THE TIME SURFACE FRONT RETREATS NORTHWARD SUNDAY
AFTERNOON AND LOW CLOUDS START MIXING OUR...CAP WILL BE IN PLACE.
THE OLD ADAGE...NEVER TRUST A WARM FRONT...APPLIES HERE THOUGH. SO I
STILL BRING AN AXIS OF CHANCE POPS NORTHWARD WITH THE WARM FRONT
DURING THE DAY SUNDAY...ERADICATING FROM THE SOUTH DURING THE
AFTERNOON. BECAUSE OF SHALLOW WARM FRONT/CLOUD COVER...I LOWERED
TEMPERATURES SOMEWHAT FOR SUNDAY...THOUGH IT WILL STILL TURN OUT
AT LEAST A FEW TO SEVERAL DEGREES WARMER THAN TODAY /SATURDAY/.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
415 PM UPDATE...DRYING OUT WITH STRONG CAP AMIDST IMPRESSIVE WARM
SECTOR SUNDAY NIGHT. I AGAIN WENT ABOVE GUIDANCE FOR LOWS MONDAY
MORNING...WHICH WILL FEEL EERILY SUMMER-LIKE AT DAWN. THE WARM HEAD
START...850MB TEMPERATURES 2 TO 3 STANDARD DEVIATIONS ABOVE
NORMAL...AND WITH SUNSHINE FOR AT LEAST A MAJORITY OF THE
DAY...WILL YIELD HIGHS ROUGHLY 25 OR SO DEGREES ABOVE NORMAL. THIS
WILL BE WITHIN A FEW TO SEVERAL DEGREES OF RECORD DAILY
HIGHS...THOUGH ACTUALLY BREAKING THE RECORDS IS CURRENTLY NOT
FORECAST /YET/.
MODELS HAVE COME INTO GOOD AGREEMENT ON TIMING OF INCOMING FRONT
MID TO LATE AFTERNOON IN THE WESTERN CWA MONDAY...SLOWING DOWN
WHILE BECOMING MORE FLOW-PARALLEL INTO MONDAY EVENING AS IT EDGES
EASTWARD. STRONG CAP EARLY IN DAY...ERODES TO POINT OF BREAKING AS
FRONT MOVES IN. AT FIRST GLANCE...FRONT APPEARS TO TAKE ANAFRONT
NATURE...AND ACTUALLY EVENTUALLY DOES. HOWEVER...DURING THE DAY
MONDAY...CLOSER INSPECTION REVEALS THAT MOISTURE IS POOLED
IMMEDIATELY ALONG FRONT RATHER THAN BEHIND...AND THERE IS ENOUGH
INSTABILITY AND SHEAR FOR THUNDERSTORMS WHICH COULD BE GUSTY /AT
LEAST IN THE WESTERN HALF OF THE AREA/. THIS WILL BEAR WATCHING IN
COMING MODEL RUNS. FOR NOW...SPC TALKS ABOUT OUR SITUATION WITHIN
THE TEXT OF THE DAY 3 OUTLOOK...BUT NOT ENOUGH CONFIDENCE TO
INCLUDE WITHIN SLIGHT RISK FOR SEVERE. I AGREE THAT UNTIL THERE IS
HIGHER CONFIDENCE IN THE INSTABILITY/CAPE EXISTING ALONG THE
FRONT...TOO EARLY TO MENTION SEVERE POTENTIAL WITHIN THE HAZARDOUS
WEATHER OUTLOOK.
DRAMATIC TEMPERATURE FALL INBOUND FOR TUESDAY BEHIND THE
FRONT...YET ONLY BACK TO NEAR SEASONAL VALUES. COLUMN APPEARS TOO
DRY IN THE MODELS TO SUPPORT MENTIONABLE POPS...SO I TOOK WHAT
LITTLE WE HAD IN THE FORECAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
GNRLY ZONAL FLOW IS FCST IN THE MEDIUM RNG. HI PRES IS XPCTD TO BRING
FAIR WEATHER ON WED...WITH ANOTHER FNTL PSSG ON THU. LATE IN THE
PD...DEEPENING TROF MOVG INTO THE OH VLY MAY BRING UNSETTLED WX
FRI INTO SAT. NO SIG CHGS TO HPC GUIDANCE OTHER THAN BEING A BIT
MORE OPTIMISTIC ON CLD CVR TUE NGT INTO WED.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
WRM FNT OVER ERN OH AND NRN PA WILL LFT THRU THE REGION TODAY
BRINGING SCT SHWRS AND BRIEFLY LWRD CIGS. AIR BLO LIFT NEAR THE
SFC IS STILL FAIRLY DRY SO IFR CIGS AND VSBY ARE NOT LIKELY BEFORE
SUNRISE...BUT OCNL MVFR CIGS SEEM LIKELY...ESP OVER THE HILLTOPS
TERMINALS. LIGT WINDS THIS MRNG WILL BECOME SLY ON SUN BHD THE FNT
WITH INCRSD MIXING. ALSO...MIXING WILL HELP RAISE CIGS AND THEY
SHD REMAIN VFR THRU THE END OF THE TAF PD. ANY SHWRS WILL BE LGT
THIS MRNG.
.OUTLOOK...
SUN NGT...VFR.
MON...VFR...BUT A BAND OF MVFR CIGS/SHRA PSBL WITH FROPA LATE MON OR
MON EVNG.
MON NGT THRU WED NGT...VFR.
THU...SCT MVFR IN -SHRA.
&&
.FIRE WEATHER...
FIRE SENSITIVE CONDITIONS AGAIN THIS AFTERNOON...WITH AREA WIDE
RELATIVE HUMIDITY WELL BELOW 30 PERCENT FOR MOST OF THE AREA...AND
GUSTS NEAR 20 MPH IN THE POCONOS. FINE FUELS CONTINUE TO REMAIN
VERY DRY RUNNING BETWEEN 5 AND 8 PERCENT. HOWEVER...FIRE THREAT
IS NOW BEING MITIGATED BY THICKENING HIGH CLOUDS THE REMAINDER OF
THE AFTERNOON...WHICH WILL LIMIT MIXING DOWN OF WINDS. WITH GUSTS
NOT EXPECTED TO CONSISTENTLY REACH CRITERIA LEVELS...NO RED FLAG
NEEDED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...CMG/HEDEN/MDP
SHORT TERM...MDP
LONG TERM...
AVIATION...DGM
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1242 AM EDT SUN APR 15 2012
.SYNOPSIS...
A WARM FRONT WILL PASS THROUGH THE REGION TONIGHT INTO
SUNDAY...ACCOMPANIED BY A CHANCE OF SHOWERS AND PERHAPS
THUNDER...WHICH WILL SHIFT NORTHWARD WITH TIME. TEMPERATURES
WILL CONTINUE TO SURGE WARMER SUNDAY AND ESPECIALLY MONDAY...TO
THE TUNE OF 25 DEGREES OR SO ABOVE NORMAL. A COLD FRONT WILL PASS
MONDAY AFTERNOON INTO EVENING...WITH SHOWERS AND A CHANCE OF
THUNDER. TEMPERATURES RETURN TO MORE SEASONABLE LEVELS FOR
MIDWEEK.
&&
.NEAR TERM /THROUGH TODAY/...
1245 AM UPDATE...MINOR UPDATE. INITIALLY DESPITE DECENT RADAR
RETURNS IN SOUTHERN AND CENTRAL NY...WE WERE NOT GETTING PRECIP AT
THE GROUND DUE TO VERY DRY BOUNDARY LAYER CONDITIONS. WITH A FEW
OBS NOW REPORTING VERY LIGHT RAIN...ADDED ISOLATED SHOWERS TO
THESE AREAS OVERNIGHT. THE PREVIOUS AFD IS BELOW...
1010 PM UPDATE... AS DISCUSSED IN THE PREVIOUS
UPDATE...SHOWERS EXITING THE OHIO VLY CONTINUE TO MOVE ACROSS
ACROSS SOUTHWESTERN PA THIS EVENING. CONSIDERING THAT THE LOW-
LEVEL JET IS EXPECTED TO VEER TOWARDS A WESTERLY DIRECTION
OVERNIGHT...CURRENT THINKING IS THAT MUCH OF THE FORECAST AREA
WILL NOT BE IMPACTED BY THIS FEATURE. AS A RESULT...HAVE TRIMMED
POPS EVEN FURTHER WITH THE LATEST UPDATE. CLOSER TO HOME...LATEST
RADAR TRENDS STILL SHOWING ISOLATED LIGHT SHOWER ACTIVITY MOVING
THROUGH THE TWIN TIERS AND NORTHEAST PA...HOWEVER WITH DEWPOINT
DEPRESSIONS STILL REMAINING ANYWHERE BETWEEN 10-20
DEGREES...EXPECT NOTHING MORE THAN A SPRINKLE OR LGT SHOWER AT
BEST. IN GENERAL...HAVE MAINTAINED SLGT CHC TO CHC MENTION FROM
THE TWIN TIERS SOUTH. ASIDE FROM MINOR TEMP/DEWPOINT
ADJUSTMENTS...NO OTHER CHANGES NEEDED AT THIS TIME.
750 PM UPDATE...AS STATED IN THE PREVIOUS NEAR TERM
DISCUSSION...CURRENT ACTIVITY MOVING OVER THE FORECAST AREA IS
HAVING LITTLE IMPACT AS DEWPOINT DEPRESSIONS REMAIN ANYWHERE
BETWEEN 20-25 DEGREES EARLY THIS EVENING. AS THIS INITIAL SHIELD
EXITS STAGE RIGHT...ATTENTION WILL THEN SHIFT TO NEXT AREA OF
PRECIP NOW ENTERING WESTERN PA FROM THE OHIO VLY. QUICK LOOK AT
REGIONAL RADAR MOSAIC SHOWS THIS ACTIVITY MOVING EAST THIS EVENING
IN A DUE EASTERLY MOTION...SUGGESTING MUCH OF THIS ACTIVITY WILL
REMAIN SOUTH OF THE NY/PA STATE LINE..AND POSSIBLY EVEN THE ENTIRE
CWA. LATEST HRRR HIGH RES SIMULATED REFLECTIVITY ALONG WITH THE
LATEST RUC QPF FCST SUPPORT THIS LINE OF THINKING AS THE LOW-LEVEL
JET VEERS AND BECOMES NEARLY WESTERLY OVERNIGHT. BASED ON
THIS...FEEL LITTLE IF ANY PRECIP WILL OCCUR FROM THE FINGER LAKES
NORTH...AND WE HAVE TRIMMED POPS ACROSS THESE AREAS ACCORDINGLY.
WE MAY HAVE TO CONTINUE TO TRIMMING POPS FROM NORTH TO SOUTH WITH
THE NEXT UPDATE BASED ON CURRENT TRAJECTORIES BUT WILL CONTINUE TO
MONITOR TRENDS BEFORE MAKING ANY WHOLESALE CHANGES. ASIDE FROM
THAT...JUST SOME MINOR COSMETIC CHANGES TO TEMPS AND DEWPOINTS.
415 PM UPDATE...DESPITE BUSY LOOKING RADAR WITH INCOMING
SHOWERS...VERY DRY LOW LEVELS ARE MAKING THE TOP DOWN MOISTENING
PROCESS GRADUAL...WITH DEW POINT DEPRESSIONS OF ROUGHLY 30 DEGREES
WEST TO ALMOST 40 DEGREES EAST. ONLY EXPECTING SPRINKLES TO
ENCROACH LATE AFTERNOON TO EARLY EVENING...BEFORE 850MB JET CAN
BRING IN ENOUGH MOISTURE FOR MORE SIGNIFICANT RAIN CHANCES. LATEST
MODEL RUNS ARE AGREEING THAT AN EMBEDDED NORTHERN STREAM SHORTWAVE
WILL DROP WNW TO ENE THROUGH THE AREA 01Z-04Z. MODELS DISAGREE
DETAILS OF SHOWER ACTIVITY...BUT CONSENSUS HAS DEFINITELY SHIFTED
TOWARDS FAVORING SOUTHWESTERN ZONES...BECAUSE OF POSITIONING OF
WARM FRONT...AND EFFECT OF DRY AIR FARTHER NORTH AND EAST.
REGARDLESS...WAVE HEADS OUT SHORTLY AFTER MIDNIGHT FOR A RELATIVE
LULL IN ACTIVITY DURING THE PREDAWN HOURS. POPS HAVE BEEN ADJUSTED
ACCORDINGLY. ALSO...WITH AMOUNT OF CLOUD COVER AND GOOD MIXING...I
WENT WELL ABOVE MAV GUIDANCE AND SLIGHTLY ABOVE MET GUIDANCE FOR
LOW TEMPERATURES.
SUNDAY IS NOT LOOKING VERY FAVORABLE FOR CONVECTION...COMPARED TO
EARLIER MODEL RUNS. SHALLOW WARM FRONT...WITH SURGING HEIGHTS
ALOFT YET DELAYED RESPONSE NEAR THE SURFACE...WILL ALLOW FOR AN
INHIBITIVE CAP TO DEVELOP ABOVE LOWERING CLOUD COVER LATE TONIGHT
INTO SUNDAY MORNING. CLOUD COVER WILL LIMIT AMOUNT OF WARMING IN
THE MORNING. BY THE TIME SURFACE FRONT RETREATS NORTHWARD SUNDAY
AFTERNOON AND LOW CLOUDS START MIXING OUR...CAP WILL BE IN PLACE.
THE OLD ADAGE...NEVER TRUST A WARM FRONT...APPLIES HERE THOUGH. SO I
STILL BRING AN AXIS OF CHANCE POPS NORTHWARD WITH THE WARM FRONT
DURING THE DAY SUNDAY...ERADICATING FROM THE SOUTH DURING THE
AFTERNOON. BECAUSE OF SHALLOW WARM FRONT/CLOUD COVER...I LOWERED
TEMPERATURES SOMEWHAT FOR SUNDAY...THOUGH IT WILL STILL TURN OUT
AT LEAST A FEW TO SEVERAL DEGREES WARMER THAN TODAY /SATURDAY/.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
415 PM UPDATE...DRYING OUT WITH STRONG CAP AMIDST IMPRESSIVE WARM
SECTOR SUNDAY NIGHT. I AGAIN WENT ABOVE GUIDANCE FOR LOWS MONDAY
MORNING...WHICH WILL FEEL EERILY SUMMER-LIKE AT DAWN. THE WARM HEAD
START...850MB TEMPERATURES 2 TO 3 STANDARD DEVIATIONS ABOVE
NORMAL...AND WITH SUNSHINE FOR AT LEAST A MAJORITY OF THE
DAY...WILL YIELD HIGHS ROUGHLY 25 OR SO DEGREES ABOVE NORMAL. THIS
WILL BE WITHIN A FEW TO SEVERAL DEGREES OF RECORD DAILY
HIGHS...THOUGH ACTUALLY BREAKING THE RECORDS IS CURRENTLY NOT
FORECAST /YET/.
MODELS HAVE COME INTO GOOD AGREEMENT ON TIMING OF INCOMING FRONT
MID TO LATE AFTERNOON IN THE WESTERN CWA MONDAY...SLOWING DOWN
WHILE BECOMING MORE FLOW-PARALLEL INTO MONDAY EVENING AS IT EDGES
EASTWARD. STRONG CAP EARLY IN DAY...ERODES TO POINT OF BREAKING AS
FRONT MOVES IN. AT FIRST GLANCE...FRONT APPEARS TO TAKE ANAFRONT
NATURE...AND ACTUALLY EVENTUALLY DOES. HOWEVER...DURING THE DAY
MONDAY...CLOSER INSPECTION REVEALS THAT MOISTURE IS POOLED
IMMEDIATELY ALONG FRONT RATHER THAN BEHIND...AND THERE IS ENOUGH
INSTABILITY AND SHEAR FOR THUNDERSTORMS WHICH COULD BE GUSTY /AT
LEAST IN THE WESTERN HALF OF THE AREA/. THIS WILL BEAR WATCHING IN
COMING MODEL RUNS. FOR NOW...SPC TALKS ABOUT OUR SITUATION WITHIN
THE TEXT OF THE DAY 3 OUTLOOK...BUT NOT ENOUGH CONFIDENCE TO
INCLUDE WITHIN SLIGHT RISK FOR SEVERE. I AGREE THAT UNTIL THERE IS
HIGHER CONFIDENCE IN THE INSTABILITY/CAPE EXISTING ALONG THE
FRONT...TOO EARLY TO MENTION SEVERE POTENTIAL WITHIN THE HAZARDOUS
WEATHER OUTLOOK.
DRAMATIC TEMPERATURE FALL INBOUND FOR TUESDAY BEHIND THE
FRONT...YET ONLY BACK TO NEAR SEASONAL VALUES. COLUMN APPEARS TOO
DRY IN THE MODELS TO SUPPORT MENTIONABLE POPS...SO I TOOK WHAT
LITTLE WE HAD IN THE FORECAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
GNRLY ZONAL FLOW IS FCST IN THE MEDIUM RNG. HI PRES IS XPCTD TO BRING
FAIR WEATHER ON WED...WITH ANOTHER FNTL PSSG ON THU. LATE IN THE
PD...DEEPENING TROF MOVG INTO THE OH VLY MAY BRING UNSETTLED WX
FRI INTO SAT. NO SIG CHGS TO HPC GUIDANCE OTHER THAN BEING A BIT
MORE OPTIMISTIC ON CLD CVR TUE NGT INTO WED.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
00Z SUN UPDATE... TOUGH CALL OVERNIGHT WITH REGARDS TO PCPN.
CURRENT INDICATIONS ARE THAT MOST OF THE RAIN WILL STAY S OF OUR
TERMINALS...OTHER THAN A FEW SPRINKLES AT KELM/KAVP MAINLY. AS A
RESULT...VSBY`S SHOULD STAY UNRESTRICTED.
HOWEVER...IT STILL APPEARS THAT LWR CIGS WILL OVERSPREAD THE RGN
FROM W TO E LATER THIS EVE...THEN PERSIST TIL THE MIDDAY HRS SUN.
WE`LL BRING IN MVFR CIGS IN THE 04-07Z TIME FRAME...THEN INDICATE
SOME IMPROVEMENT BACK TO VFR IN THE 14-17Z PD SUN.
LIGHT VRBL WINDS (AOB 5 KT) OVERNIGHT...WILL BECOME SWLY BY EARLY
SUN AFTN...INCRG TO ARND 10 KT.
.OUTLOOK...
SUN NGT...VFR.
MON...VFR...BUT A BAND OF MVFR CIGS/SHRA PSBL WITH FROPA LATE MON OR
MON EVNG.
MON NGT THRU WED NGT...VFR.
THU...SCT MVFR IN -SHRA.
&&
.FIRE WEATHER...
FIRE SENSITIVE CONDITIONS AGAIN THIS AFTERNOON...WITH AREA WIDE
RELATIVE HUMIDITY WELL BELOW 30 PERCENT FOR MOST OF THE AREA...AND
GUSTS NEAR 20 MPH IN THE POCONOS. FINE FUELS CONTINUE TO REMAIN
VERY DRY RUNNING BETWEEN 5 AND 8 PERCENT. HOWEVER...FIRE THREAT
IS NOW BEING MITIGATED BY THICKENING HIGH CLOUDS THE REMAINDER OF
THE AFTERNOON...WHICH WILL LIMIT MIXING DOWN OF WINDS. WITH GUSTS
NOT EXPECTED TO CONSISTENTLY REACH CRITERIA LEVELS...NO RED FLAG
NEEDED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...CMG/HEDEN/MDP
SHORT TERM...MDP
LONG TERM...
AVIATION...MLJ
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS TULSA OK
339 AM CDT SUN APR 15 2012
.DISCUSSION...
LARGE H5 TROUGH IS STARTING TO PIVOT EAST. MAJOR PORTION OF THE
TROUGH EJECTS TODAY...WITH REMAINDER OF TROUGH SWEEPING EAST
MONDAY AND MONDAY NIGHT. SQUALL LINE AND PSEUDO FRONT WILL PUSH
THROUGH EASTERN OK AND NORTHWEST AR TODAY. MAIN COLD FRONT/SURFACE
TROUGH WILL BE NEAR OMA-CDS LINE BY 7 PM TONIGHT...THEN SWING QUICKLY
EAST TONIGHT. NORTHWEST WINDS AND HIGH PRESSURE WILL BUILD OVER
THE AREA ON MONDAY.
NORTHWEST FLOW ALOFT WILL BRING A SHORT WAVE TROUGH THROUGH ON
WEDNESDAY...WITH SOME CLOUDINESS...BUT EXPECT NO PRECIPITATION.
TROUGH APPEARS TO MINOR OUT AS IT MOVES SOUTHEAST...AND FLOW
BECOMES NEARLY ZONAL. BETTER CHANCE OF SHOWERS OR THUNDERSTORMS
DEVELOPS ON THURSDAY AND THURSDAY NIGHT...AS H5 TROUGH DEVELOPS IN
THE FLOW AND MOVES OVER THE CENTRAL PLAINS. THE GFS AND ECMWF
TIMING ARE A LITTLE DIFFERENT...BUT BOTH SEE THIS DEVELOPMENT.
KEPT CHANCE POPS FOR THIS EVENT. MAJOR TROUGH EVENTUALLY DEVELOPS
BY NEXT WEEKEND OVER THE SOUTHEAST STATES...PUTTING OK IN NORTHWEST
FLOW.
TIMING OF PRECIPITATION THIS MORNING AND LATER TODAY IS THE
PRIMARY ISSUE. ANTICIPATE THE LINE OF STORMS TO BE FROM ABOUT
NOWATA TO TULSA TO OKEMAH AROUND 6-7 AM. THE PRECIPITATION SHOULD
REACH NORTHWEST ARKANSAS BY MID TO LATE MORNING. EXPECT THE
EXISTING LINE TO CARRY ALL THE PRECIPITATION...AND SIGNIFICANTLY
LOWERED OR DROPPED POPS BEHIND THE LINE.
GENERALLY STAYED CLOSE TO MAV/MEX MOS GUIDANCE FOR TEMPS...WITH
MINOR ADJUSTMENT TO ECMWF IN A COUPLE OF PERIODS.
WIND GUSTS ARE BECOMING MORE ISOLATED AND LATEST RUC RELAXES
SURFACE PRESSURE GRADIENT...SO WILL DROP THE WIND ADVISORY.
STILL...THERE WILL BE FREQUENT GUSTS OVER 30 MPH UNTIL THE LINE OF
STORMS MOVES THROUGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 77 47 72 49 / 50 10 0 10
FSM 79 50 72 48 / 80 10 10 10
MLC 78 47 74 47 / 70 10 0 10
BVO 72 46 72 43 / 30 20 0 10
FYV 71 45 69 42 / 80 20 0 10
BYV 73 46 68 46 / 80 20 10 10
MKO 75 47 74 47 / 70 10 10 10
MIO 76 46 70 46 / 70 20 0 10
F10 76 48 72 50 / 60 10 0 0
HHW 77 49 75 50 / 70 10 0 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY UNTIL 4 AM SUNDAY FOR OKZ054-OKZ055-OKZ059-OKZ060-
OKZ064-OKZ065-OKZ066.
AR...NONE.
&&
$$
SHORT TERM...22
LONG TERM....02
AREA FORECAST DISCUSSION
NWS TULSA OK
104 AM CDT SUN APR 15 2012
...MESOSCALE UPDATE...
.DISCUSSION...
SURFACE PRESSURE GRADIENT HAS TIGHTENED AND IS SUPPORTING FREQUENT
GUSTS OVER 40 MPH OVER THE AREA GENERALLY WEST OF HIGHWAY 75.
THESE ARE EVIDENT FROM THE OK MESONET DATA. THERE ARE A COUPLE OF
MESONET DATA FARTHER SOUTH TOWARD MCALESTER THAT HAVE GUSTED TO 41
AND 43 MPH...BUT FEEL THESE ARE OUTLIERS AND WILL NOT LAST. WILL
KNOW FOR SURE IN A COUPLE OF HOURS.
KEPT THE ADVISORY UP UNTIL THE 4 AM FORECASTS GO OUT. BY THAT
TIME...THE RUC RELAXES THE GRADIENT...PROBABLY IN RESPONSE TO THE
FRONT GETTING CLOSER. SHOULD BE ABLE TO DROP THE ADVISORY AT 4
AM...BUT WILL LIKELY BE MONITORING OTHER METEOROLOGICAL EVENTS BY
THAT TIME...
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY UNTIL 4 AM SUNDAY FOR OKZ054-OKZ055-OKZ059-OKZ060-
OKZ064-OKZ065-OKZ066.
AR...NONE.
&&
$$
LONG TERM....02
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
857 AM EDT SUN APR 15 2012
.SYNOPSIS...SHOWERS AND EVEN THE RUMBLE OF THUNDER ARE POSSIBLE
FROM LATE THIS MORNING INTO THIS AFTERNOON AS A WARM FRONT MOVES
THROUGH THE AREA...WITH THE MOST WIDESPREAD ACTIVITY ACROSS
CENTRAL NEW YORK. WE WILL BE DRY TONIGHT INTO MOST OF MONDAY BUT THE
BIGGER STORY WILL BE THE WARM-UP. WE EXPECT HIGHS TO BE INTO THE
80S MOST LOCATIONS MONDAY AFTERNOON. A COLD FRONT WILL BRING A
SHOT AT SHOWERS AND THUNDERSTORMS TOWARD MONDAY EVENING AND INTO
THE OVERNIGHT. BEHIND THE FRONT TEMPERATURES RETURN TO MORE
SEASONABLE LEVELS FOR MIDWEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
855 AM UPDATE...FOR THE MRNG UPDATE WE HAVE OPTED TO RAISE POPS TO
LOW LIKELY ACRS A GOOD PORTION OF CNTRL NY AS THE NXT WAVE APRCHS
LATER THIS MRNG AND AFTN. GIVEN THE CLDS AND XPCTD SHRA WE ALSO
TWEEKED DOWN MAXES BY A FEW DEG. PREV BLO...
4 AM UPDATE...THE FORECAST IS IN VERY GOOD SHAPE AND NOT MUCH TO
CHANGE. AN AREA OF SHOWERS NOW OVER THE EASTERN PART OF THE CWA
WILL EXIT STAGE RIGHT PRIOR TO DAYBREAK WITH MOST OF THIS MORNING
ENDING UP DRY. WE WAIT THE ARRIVAL OF A WARM FRONT NOW OVER THE
OHIO VALLEY LATER TODAY. HI RES MODELS SUCH AS THE
ARW...NMM...NAM12 AND HRRR ARE ALL IN GOOD AGREEMENT WITH SOME
SCT. SHOWERS DEVELOPING OVER THE WESTERN AND CENTRAL PART OF OUR
CWA...MAINLY NORTH OF THE NY/PA LINE...BETWEEN 15Z AND 18Z. AS THE
WARM FRONT LIFTS NORTH...MAIN SHOT AT SHOWERS WILL TRACK NORTHEAST
THROUGH THE MOHAWK VALLEY LATER TODAY. BEST SHOT AT SHOWERS IN
NORTHERN PA LOOKS TO BE BRADFORD OR SUSQUEHANNA COUNTY...WITH
AGAIN HIGHEST POPS OVER NY. LEFT IN A SHOT AT ISOLATED THUNDER
TODAY BUT WITH A CAP EARLY THIS MORNING AND PLENTY OF CLOUDS
AROUND...INSTABILITY LOOKS TO BE LACKING TOO MUCH TO BE A REAL
CONCERN FOR MORE THAN A FEW RUMBLES. TOWARD LATE IN THE
DAY...FOCUS FOR SHOWERS WILL SHIFT NORTH WITH DRIER AIR BUILDING
IN FROM THE SOUTHWEST.
TONIGHT...DRYING TREND WILL CONTINUE AS WE GET INTO THE WARM
SECTOR AND PRONOUNCED DRYING OCCURS FROM NEAR THE SURFACE UP
THROUGH THE ENTIRE COLUMN. IT DOES APPEAR A FEW SHOWERS MAY
LINGER OR HANG UP OVER ONEIDA COUNTY BUT EVEN HERE WE DRY OUT
TOWARD OR SLIGHTLY AFTER MIDNIGHT AT THE LATEST. LIKE THE PREVIOUS
FORECASTER`S IDEA OF WARMER THAN GUIDANCE AND STAYED THE COURSE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
MONDAY...BREAK OUT THE SHORTS. SEE LITTLE TO CHANGE FROM OUR
FORECAST OF 80-86 ACROSS THE CWA. STILL EXPECTING MOST OF THE DAY
TO BE DRY WITH EXCELLENT AGREEMENT BETWEEN THE MODELS...INCLUDING
THE GFS/NAM/CANADIAN ALONG WITH THE HIGHER RESOLUTION MODELS. AS
A COLD FRONT APPROACHES POPS WILL INCREASE OVER THE WESTERN FINGER
LAKES INTO THE WESTERN MOHAWK VALLEY BETWEEN 21Z AND 0Z. AS FAR AS
SEVERE WEATHER POTENTIAL GOES...THE TIMING OF THE FRONT...IF
TOTALLY CORRECT AS IT STANDS NOW...MAY BE JUST A TAD TOO LATE FOR
PEAK HEATING AND THE BEST INSTABILITY. A GOOD EXAMPLE OF THIS IS
THE NAM BUFKIT SOUNDINGS FOR KSYR/KELM/KITH WHICH SHOW CAPES
AROUND 300 J/KG TOWARD EVENING...COMPARED TO KROC WHICH HAS CAPES
IN THE 700 J/KG RANGE. I LOVE THE DEPICTION FROM SPC WITH SLIGHT
RISK MAINLY ACROSS WNY...AND JUST GETTING INTO THE EXTREME WESTERN
PART OF OUR CWA...WITH SEE TEXT ELSEWHERE. THIS MATCHES UP VERY
WELL WITH THE POP FORECAST OUTLINED ABOVE THROUGH 0Z TUESDAY. WE
WILL HAVE TO WATCH THE TIMING VERY CAREFULLY BECAUSE IF THE FRONT
IS JUST A BIT FASTER...AND WE HAVE MORE INSTABILITY TO WORK
WITH...DAMAGING WINDS ARE A REAL THREAT. 0-6 KM BULK SHEAR VALUES
ON BOTH THE GFS AND NAM ARE 50-55 KTS...AND WE HAVE DRY AIR IN
BOTH THE LOW LEVELS (INVERTED V SOUNDING) AND MID-LEVELS.
MONDAY NIGHT...AS THE FRONT MOVES EAST BEST SHOT AT SOME THUNDER
AND SHOWERS WILL BE THROUGH 03Z...WITH MOISTURE AND INSTABILITY
DIMINISHING QUICKLY AS THE NIGHT WEARS ON. WITH THAT IN MIND
HIGHEST POPS WILL BE ROUGHLY NEAR I-81 AND POINTS WEST...WITH
CHANCES FOR MEASURABLE RAIN DROPPING OFF SHARPLY THE FARTHER
SOUTH AND EAST YOU GO.
TUESDAY...COOLER TEMPS FOR SURE BEHIND THE FRONT...BUT A SLOW
COOLING TREND AT 850 MB SHOULD ALLOW FOR A DECENT TEMP GRADIENT.
850S CLOSER TO +5C WILL ALLOW FOR A RANGE OF NEAR 70 OVER PIKE
COUNTY...TO 50S ACROSS THE NORTH WITH 850S SLIDING TO BELOW ZERO.
A SHORT WAVE WILL PASS TO THE NORTH OF OUR AREA BY AFTERNOON. THIS
SYSTEM WILL BE MOISTURE STARVED BUT THE SOUNDINGS ACROSS NORTHERN
ONEIDA COUNTY SHOW JUST ENOUGH MOISTURE TO WARRANT AN ISOLATED
SHOWER UP HERE FOR THE AFTERNOON HOURS. DRIER WEATHER BUILDS IN
TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
GNRLY ZONAL FLOW IS FCST IN THE MEDIUM RNG. HI PRES IS XPCTD TO BRING
FAIR WEATHER ON WED...WITH ANOTHER FNTL PSSG ON THU. LATE IN THE
PD...DEEPENING TROF MOVG INTO THE OH VLY MAY BRING UNSETTLED WX
FRI INTO SAT. NO SIG CHGS TO HPC GUIDANCE OTHER THAN BEING A BIT
MORE OPTIMISTIC ON CLD CVR TUE NGT INTO WED.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
WRM FNT OVER ERN OH AND NRN PA WILL LFT THRU THE REGION TODAY.
BETTER MIXING BHD THE FNT AND WITH HTG WILL RAISE CIGS BACK INTO
THE VFR CAT LTR TODAY...WITH JUST SOME ISLTD SHWRS. TNGT...INCRSD
MOISTURE AND LGT WINDS MAY RESULT IN A RETURN TO SOME MVFR
CIGS...ESP ACROSS NY WHERE THERE/S BETTER LL MOISTURE.
LGT AND VRBL WND THIS MRNG WILL BECOME SLY WITH MIXING LTR THIS
MRNG...AND GO BACK TO LGT MOST STATIONS TNGT AS THE BNDRY LYR
DECPLS.
.OUTLOOK...
MON...VFR...BUT A BAND OF MVFR CIGS/SHRA PSBL WITH FROPA LATE MON
OR MON EVNG.
MON NGT THRU WED NGT...VFR.
THU...SCT MVFR IN -SHRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
LONG TERM...HEDEN
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
650 AM EDT SUN APR 15 2012
.SYNOPSIS...
A FEW SHOWERS AND EVEN THE RUMBLE OF THUNDER ARE POSSIBLE FROM
LATE THIS MORNING INTO THIS AFTERNOON AS A WARM FRONT MOVES
THROUGH THE AREA. WE WILL BE DRY TONIGHT INTO MOST OF MONDAY BUT
THE BIGGER STORY WILL BE THE WARM-UP. WE EXPECT HIGHS TO BE INTO
THE 80S MOST LOCATIONS MONDAY AFTERNOON. A COLD FRONT WILL BRING A
SHOT AT SHOWERS AND THUNDERSTORMS TOWARD MONDAY EVENING AND INTO
THE OVERNIGHT. BEHIND THE FRONT TEMPERATURES RETURN TO MORE
SEASONABLE LEVELS FOR MIDWEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
4 AM UPDATE...THE FORECAST IS IN VERY GOOD SHAPE AND NOT MUCH TO
CHANGE. AN AREA OF SHOWERS NOW OVER THE EASTERN PART OF THE CWA
WILL EXIT STAGE RIGHT PRIOR TO DAYBREAK WITH MOST OF THIS MORNING
ENDING UP DRY. WE WAIT THE ARRIVAL OF A WARM FRONT NOW OVER THE
OHIO VALLEY LATER TODAY. HI RES MODELS SUCH AS THE
ARW...NMM...NAM12 AND HRRR ARE ALL IN GOOD AGREEMENT WITH SOME
SCT. SHOWERS DEVELOPING OVER THE WESTERN AND CENTRAL PART OF OUR
CWA...MAINLY NORTH OF THE NY/PA LINE...BETWEEN 15Z AND 18Z. AS THE
WARM FRONT LIFTS NORTH...MAIN SHOT AT SHOWERS WILL TRACK NORTHEAST
THROUGH THE MOHAWK VALLEY LATER TODAY. BEST SHOT AT SHOWERS IN
NORTHERN PA LOOKS TO BE BRADFORD OR SUSQUEHANNA COUNTY...WITH
AGAIN HIGHEST POPS OVER NY. LEFT IN A SHOT AT ISOLATED THUNDER
TODAY BUT WITH A CAP EARLY THIS MORNING AND PLENTY OF CLOUDS
AROUND...INSTABILITY LOOKS TO BE LACKING TOO MUCH TO BE A REAL
CONCERN FOR MORE THAN A FEW RUMBLES. TOWARD LATE IN THE
DAY...FOCUS FOR SHOWERS WILL SHIFT NORTH WITH DRIER AIR BUILDING
IN FROM THE SOUTHWEST.
TONIGHT...DRYING TREND WILL CONTINUE AS WE GET INTO THE WARM
SECTOR AND PRONOUNCED DRYING OCCURS FROM NEAR THE SURFACE UP
THROUGH THE ENTIRE COLUMN. IT DOES APPEAR A FEW SHOWERS MAY
LINGER OR HANG UP OVER ONEIDA COUNTY BUT EVEN HERE WE DRY OUT
TOWARD OR SLIGHTLY AFTER MIDNIGHT AT THE LATEST. LIKE THE PREVIOUS
FORECASTER`S IDEA OF WARMER THAN GUIDANCE AND STAYED THE COURSE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
MONDAY...BREAK OUT THE SHORTS. SEE LITTLE TO CHANGE FROM OUR
FORECAST OF 80-86 ACROSS THE CWA. STILL EXPECTING MOST OF THE DAY
TO BE DRY WITH EXCELLENT AGREEMENT BETWEEN THE MODELS...INCLUDING
THE GFS/NAM/CANADIAN ALONG WITH THE HIGHER RESOLUTION MODELS. AS
A COLD FRONT APPROACHES POPS WILL INCREASE OVER THE WESTERN FINGER
LAKES INTO THE WESTERN MOHAWK VALLEY BETWEEN 21Z AND 0Z. AS FAR AS
SEVERE WEATHER POTENTIAL GOES...THE TIMING OF THE FRONT...IF
TOTALLY CORRECT AS IT STANDS NOW...MAY BE JUST A TAD TOO LATE FOR
PEAK HEATING AND THE BEST INSTABILITY. A GOOD EXAMPLE OF THIS IS
THE NAM BUFKIT SOUNDINGS FOR KSYR/KELM/KITH WHICH SHOW CAPES
AROUND 300 J/KG TOWARD EVENING...COMPARED TO KROC WHICH HAS CAPES
IN THE 700 J/KG RANGE. I LOVE THE DEPICTION FROM SPC WITH SLIGHT
RISK MAINLY ACROSS WNY...AND JUST GETTING INTO THE EXTREME WESTERN
PART OF OUR CWA...WITH SEE TEXT ELSEWHERE. THIS MATCHES UP VERY
WELL WITH THE POP FORECAST OUTLINED ABOVE THROUGH 0Z TUESDAY. WE
WILL HAVE TO WATCH THE TIMING VERY CAREFULLY BECAUSE IF THE FRONT
IS JUST A BIT FASTER...AND WE HAVE MORE INSTABILITY TO WORK
WITH...DAMAGING WINDS ARE A REAL THREAT. 0-6 KM BULK SHEAR VALUES
ON BOTH THE GFS AND NAM ARE 50-55 KTS...AND WE HAVE DRY AIR IN
BOTH THE LOW LEVELS (INVERTED V SOUNDING) AND MID-LEVELS.
MONDAY NIGHT...AS THE FRONT MOVES EAST BEST SHOT AT SOME THUNDER
AND SHOWERS WILL BE THROUGH 03Z...WITH MOISTURE AND INSTABILITY
DIMINISHING QUICKLY AS THE NIGHT WEARS ON. WITH THAT IN MIND
HIGHEST POPS WILL BE ROUGHLY NEAR I-81 AND POINTS WEST...WITH
CHANCES FOR MEASURABLE RAIN DROPPING OFF SHARPLY THE FARTHER
SOUTH AND EAST YOU GO.
TUESDAY...COOLER TEMPS FOR SURE BEHIND THE FRONT...BUT A SLOW
COOLING TREND AT 850 MB SHOULD ALLOW FOR A DECENT TEMP GRADIENT.
850S CLOSER TO +5C WILL ALLOW FOR A RANGE OF NEAR 70 OVER PIKE
COUNTY...TO 50S ACROSS THE NORTH WITH 850S SLIDING TO BELOW ZERO.
A SHORT WAVE WILL PASS TO THE NORTH OF OUR AREA BY AFTERNOON. THIS
SYSTEM WILL BE MOISTURE STARVED BUT THE SOUNDINGS ACROSS NORTHERN
ONEIDA COUNTY SHOW JUST ENOUGH MOISTURE TO WARRANT AN ISOLATED
SHOWER UP HERE FOR THE AFTERNOON HOURS. DRIER WEATHER BUILDS IN
TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
GNRLY ZONAL FLOW IS FCST IN THE MEDIUM RNG. HI PRES IS XPCTD TO BRING
FAIR WEATHER ON WED...WITH ANOTHER FNTL PSSG ON THU. LATE IN THE
PD...DEEPENING TROF MOVG INTO THE OH VLY MAY BRING UNSETTLED WX
FRI INTO SAT. NO SIG CHGS TO HPC GUIDANCE OTHER THAN BEING A BIT
MORE OPTIMISTIC ON CLD CVR TUE NGT INTO WED.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
WRM FNT OVER ERN OH AND NRN PA WILL LFT THRU THE REGION TODAY.
BETTER MIXING BHD THE FNT AND WITH HTG WILL RAISE CIGS BACK INTO
THE VFR CAT LTR TODAY...WITH JUST SOME ISLTD SHWRS. TNGT...INCRSD
MOISTURE AND LGT WINDS MAY RESULT IN A RETURN TO SOME MVFR
CIGS...ESP ACROSS NY WHERE THERE/S BETTER LL MOISTURE.
LGT AND VRBL WND THIS MRNG WILL BECOME SLY WITH MIXING LTR THIS
MRNG...AND GO BACK TO LGT MOST STATIONS TNGT AS THE BNDRY LYR
DECPLS.
.OUTLOOK...
MON...VFR...BUT A BAND OF MVFR CIGS/SHRA PSBL WITH FROPA LATE MON
OR MON EVNG.
MON NGT THRU WED NGT...VFR.
THU...SCT MVFR IN -SHRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...HEDEN
SHORT TERM...HEDEN
LONG TERM...
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1017 AM CDT SUN APR 15 2012
.UPDATE...CONCERNED THAT FOCUS FOR INITIATION OF VIGOROUS/SUPERCELLULAR
CONVECTION WILL BE FURTHER WEST ACROSS ERN IOWA/SRN MINNESOTA
BASED ON OF UPPER JET DYNAMICS AND RUC ORIENTATION OF MLCAPE AXIS.
THESE STRONGER STORMS WOULD THEN SHIFT NORTHEAST...WELL WEST AND
NORTHWEST OF SRN WI. CRAVEN/BROOKS SVR PARAMETER POINTS TOWARDS
THIS REGION AS BEING THE BETTER INITIATION POINT AS DOES 4KM WRF-NMM.
HAVE PULLED BACK ON SEVERE WORDING FOR THE DAY AND LOWERED
POPS...ESPECIALLY IN SE WI. PLENTY OF MID/UPPER CLOUD DEBRIS
LINGERING IN SRN WI. THIN SPOTS WILL EVOLVE WHICH WILL HELP MIX
DOWN STRONGER WINDS AS 850 LOW LEVEL JET RAMPS UP. HOLDING OFF ON
AN ADVISORY AT THIS POINT BUT WILL WATCH CLOUD/MIXING TRENDS
CAREFULLY IN THIS REGARD.
PC
&&
.AVIATION/18Z TAFS/...SPOTTY MVFR CEILINGS LINGERING IN SC WI BUT
EXPECTING THESE LOWER CLOUDS TO MIX OUT WITH TIME. GUSTY SOUTH
WINDS LIKELY TO EVOLVE AS 850 MILLIBAR LOW LEVEL JET RAMPS UP.
CONVECTIVE TRENDS SUGGEST DEVELOPMENT OF MOST VIGOROUS CONVECTION
WILL BE ACROSS IOWA/MINNESOTA AND PERHAPS SHIFT NORTH AND WEST OF
SRN WI. AS SURFACE COLD FRONT DRAWS CLOSER TONIGHT THERE WILL BE A
BETTER CHANCE OF SHOWERS/STORMS THOUGH SOME MODELS SUGGEST A MISS
FOR SRN WI. STAY TUNED.
PC
&&
.MARINE...NO CHANGE TO SMALL CRAFT/GALE HEADLINES...BUT HAVE HOISTED A
DENSE FOG ADVISORY FOR THE NORTHERN ZONE TO ACCOUNT FOR LOWER
VSBYS SEEN ON WEBCAMS. THIS EXPECTED TO IMPROVE THIS AFTERNOON AS
WARM FRONT LIFTS FURTHER NORTH AND WINDS INCREASE.
PC
&&
.PREV DISCUSSION... /ISSUED 555 AM CDT SUN APR 15 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM
MOST OF THE LOW TO MID LEVEL BAROCLINIC ZONE AND WARM ADVECTION WILL
SHIFT NWD THIS MORNING ALONG WITH THE TSTORMS. HOWEVER THE NOSE OF A
BROAD LOW LEVEL JET STREAM WILL REMAIN IN THE VICINITY OF SRN WI SO
SCT SHOWERS/TSTORMS EXPECTED AT TIMES THROUGH THE DAY. DESPITE THIS
SOME BREAKS IN THE CLOUDS ARE EXPECTED LATER TODAY WITHIN THE WARM
SECTOR WITH TEMPS EXPECTED TO CLIMB INTO THE MID 70S.
LOW PRESSURE OVER THE CENTRAL PLAINS WILL DEEPEN TO 986 MB AS IT
MOVES INTO SRN MN BY LATE AFTERNOON AND THEN SLOWLY WEAKEN AS IT
MOVES ACROSS NRN WI. A 60-70 KT LLJ WILL BLAST NWD THROUGH THE WRN
HALF OF WI THIS AFTERNOON AND THEN SHIFT EWD TNT AHEAD OF THE COLD
FRONT. THE POLAR TROUGH/UPPER LOW MOVING INTO MN TNT AND NORTH TO
SOUTH PRE-FRONTAL TROUGH EXTENDING FROM THE LOW WILL TRIGGER MORE
ORGANIZED TSTORMS LATE THIS AFTERNOON AND EVENING. VERY STRONG WIND
SHEAR AND MLCAPES OF 500-1300 J/KG WILL BE IN PLACE FOR SUPERCELLS
OR EMBEDDED SUPERCELLS WITHIN A SEVERE SQUALL LINE. THUS THE SLIGHT
TO MDT RISK FOR ALL TYPES OF SEVERE INCLUDING TORNADOES. IN ADDITION
TO THE STORMS...THE LOW LEVEL JET WILL CREATE WINDY CONDITIONS LATE
THIS AFTERNOON AND FOR MUCH OF THE NIGHT AS LOW LEVEL LAPSE RATES
REMAIN FAIRLY STEEP. WITH 50KTS AT 2 KFT...MOMENTUM TRANSFER OF SVR
WINDS WITH THE TSTORMS WILL BE AN ADDITIONAL FACTOR.
MONDAY AND TUESDAY...FORECAST CONFIDENCE MEDIUM
KEPT CHANCE POPS ON MONDAY WITH TRAILING PRECIP ON THE BACK SIDE OF
THE SFC LOW...ALONG UPPER TROUGH AXIS. TEMPS MAY GENERALLY FALL FROM
MORNING HIGHS...AS COLD ADVECTION...CLOUDS...AND POSSIBLE PRECIP
COOL THINGS OFF. LOOKING EVEN WINDIER WITH LATEST MODEL SOUNDINGS
SUGGESTING GUSTS TO ALMOST 45 MPH POSSIBLE UNDER TIGHT PRESSURE
GRADIENT ON THE BACKSIDE OF THE LOW. MAY HAVE TO EVENTUALLY CONSIDER
A WIND ADVISORY IF MODELS REMAIN THIS WINDY.
COULD SEE SOME FROST MONDAY NIGHT WITH 925 MB FALLING TO AROUND 0C
OR COLDER...ALONG WITH DECREASING CLOUDS AND LIGHTER WINDS. WENT
WITH LOWS IN THE LOW 30S MOST PLACES.
SHOULD BE DRY WITH MOSTLY SUNNY SKIES TUESDAY UNDER SFC HIGH
PRESSURE. NEAR NORMAL HIGH TEMPS EXPECTED EXCEPT FOR NEAR LAKE
MICHIGAN WHERE A LAKE BREEZE SHOULD EASILY DEVELOP AND KEEP THINGS
COOLER.
WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE MEDIUM
MODELS CONTINUE TO COME INTO BETTER AGREEMENT FOR MIDWEEK
SYSTEM...WITH SFC LOW PRESSURE WEDNESDAY AFTERNOON AND THURSDAY
EVENING. SOME TIMING AND PLACEMENT ISSUES STILL EXIST AMONG MODEL
SOLUTIONS...BUT ENOUGH CONFIDENCE FOR HIGH CHANCE TO LIKELY POPS
WEDNESDAY...WITH A CHANCE FOR PRECIP LINGERING INTO THE NIGHT.
MAINLY DRY WEATHER EXPECTED THURSDAY...THOUGH THE ECMWF AND CANADIAN
BRING PRECIP WITH THE NEXT SYSTEM TO OUR DOORSTEP BY EVENING.
SHOULD SEE TEMPS NEAR TO A COUPLE DEGREES ABOVE NORMAL FOR WEDNESDAY
AND THURSDAY.
THURSDAY NIGHT THROUGH SATURDAY...FORECAST CONFIDENCE LOW
NOT MUCH CONFIDENCE WITH FORECAST FROM THURSDAY NIGHT INTO THE
WEEKEND. MODELS CONTINUE TO BOUNCE ALL OVER THE PLACE WITH THURSDAY
NIGHT/FRIDAY SYSTEM. LATEST GFS IS DRY...WHILE THE ECMWF AND
CANADIAN ARE FARTHER NORTH AND BRING PRECIP ACROSS MUCH OR ALL OF
THE FORECAST AREA. STILL POTENTIAL FOR THIS STORM TO BE CHILLY...AS
THE ECMWF SUGGESTING A CHANGEOVER TO SNOW FOR A TIME THU NIGHT. A
CONSENSUS OF MODEL TEMPS NOT COLD ENOUGH FOR SNOW...SO KEPT RAIN
SHOWERS FOR NOW. WILL NEED TO CONTINUE TO KEEP AN EYE ON THIS LATE
WEEK STORM THOUGH...AS IT MAY BE INTERESTING IF ECMWF SOLUTION
PERSISTS.
UNCERTAINTY CONTINUES ON SATURDAY...WITH THE GFS DRY AND THE ECMWF
BRINGING MORE PRECIP BY EVENING.
AVIATION/12Z TAFS/...WIDESPREAD SHOWERS AND TSTORMS EARLY THIS AM
WILL BECOME MORE SCT FOR THE REMAINDER OF THE DAY AS THE WARM SECTOR
MOVES INTO SRN WI. ANOTHER ORGANIZED ROUND OF THUNDERSTORMS...SOME
SEVERE...IS EXPECTED THIS EVENING WITH A PRE-FRONTAL TROUGH LINE. A
SLY 60-70 KT LLJ WILL MAKE FOR WINDY AND GUSTY CONDITIONS LATE THIS
AFTERNOON AND TONIGHT. LIFR TO IFR CIGS AND MVFR VSBYS WILL
TRANSITION TO AREAS OF MVFR CIGS AND VFR VSBYS FOR THIS AFTERNOON
BEFORE WORSENING TNT WITH THE CONVECTION.
MARINE...A SMALL CRAFT ADVISORY GOES IN EFFECT TODAY AND IS
UPGRADED TO A GALE WARNING FOR TONIGHT THROUGH MONDAY AS STRONG LOW
PRESSURE AND LOW LEVEL JET STREAM MOVES ACROSS THE STATE. ADVECTION
FOG THIS MORNING FROM PORT WASHINGTON TO SHEBOYGAN WILL END BY
AFTERNOON AS THE WARM FRONT MOVES THROUGH THE REGION. THE RAIN AT
TIMES WILL BREAK UP THE FOG THIS MORNING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LMZ645-646.
GALE WARNING FROM 7 PM THIS EVENING TO 7 PM CDT MONDAY FOR
LMZ643>646.
SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LMZ643-644.
DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR LMZ643.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
MONDAY THROUGH SATURDAY...DDV
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1253 PM EDT SUN APR 15 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED OFF THE SOUTHEAST COAST WILL INFLUENCE OUR
REGION THROUGH MONDAY. A COLD FRONT FROM THE NORTHWEST IS FORECAST
TO CROSS THE REGION MONDAY NIGHT. HIGH PRESSURE WILL THEN BUILD
BACK IN FOR TUESDAY THROUGH THURSDAY. ANOTHER COLD FRONT IS
ANTICIPATED TO ARRIVE ON THURSDAY NIGHT OR FRIDAY. A STRONGER
STORM MAY IMPACT THE AREA OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WITH THE EARLY AFTERNOON UPDATE, HOURLY TEMPERATURES WERE ADJUSTED
DOWN A FEW DEGREES ACROSS OUR CENTRAL TO NORTHERN ZONES WHERE MID-
LEVEL CLOUDS HAD REMAINED THICKER. WITH MORE BREAKS AND THE CLOUDS
THINNING OVER THESE AREAS EARLY THIS AFTERNOON, FCST MAX
TEMPERATURES STILL LOOK TO BE ON TRACK. MEANWHILE, GRADUAL CLEARING
HAD OCCURRED EARLIER ACROSS OUR DELMARVA ZONES, AND LITTLE
ADJUSTMENT WAS NEEDED FOR TEMPS. WE HAVE KEPT ISOLATED SHOWERS IN
THE FORECAST OVER THE NEXT SEVERAL HOURS FOR OUR FAR NORTHWEST
ZONES, AS THE HRRR APPEARED TO HAVE A GOOD REPRESENTATION OF THE
CURRENT ACTIVITY MOVING EASTWARD ALONG THE PA/NY BORDER.
OTHERWISE, VERY WEAK IMPULSES AT MID LEVEL LOOK LIKE THEY WILL BE
FIGHTING A LOSING BATTLE FROM SOUTH TO NORTH AGAINST THE BUILDING
RIDGE WITH THE AXIS TO OUR WEST TODAY. SHOWER ACTIVITY HAD GONE TO
THE ISOLATED LEVEL THIS MORNING, AND BY THIS AFTERNOON WE STILL
EXPECT AT LEAST THE SOUTHERN ZONES TO BE CLEAR OF ANY RAINFALL.
SEVERAL DAYS AGO, THIS WARM FRONTAL PASSAGE WAS DEPICTED AS
PRODUCING SOME SIGNIFICANT RAIN, BUT THAT HAS NOT YET COME TO
FRUITION. BARRING SOME UNEXPECTED DEVELOPMENT OVER OUR NORTHERN
ZONES LATER TODAY, IT WON`T.
WARM ADVECTION CLOUDS ARE FORECAST TO LINGER OVER MOST OF OUR
REGION THIS MORNING WITH A DECREASE IN CLOUD COVER THIS AFTERNOON
AS THE MID LEVEL RIDGE CONTINUES TO BUILD OVERHEAD.
WITH MARGINAL INSTABILITY ACROSS OUR NORTHERN COUNTIES, WE HAVE
MENTIONED ISOLATED SHOWERS THERE INTO THE EARLY AFTERNOON HOURS.
DUE TO THE SOUTHWESTERLY FLOW AND INCREASING SUNSHINE THIS
AFTERNOON, TEMPERATURES SHOULD RISE WELL INTO THE 70S IN OUR
REGION WITH A FEW SPOTS IN OUR WESTERN AND SOUTHERN COUNTIES
POSSIBLY REACHING THE 80 DEGREE MARK. THE NAM AND ECMWF FORECASTS
FOR 925 MB TEMPERATURES AT 12Z TODAY BASICALLY VERIFIED, AND THEIR
CONSENSUS FORECAST GENERALLY SUPPORTS THE AFTERNOON MAXES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE MID LEVEL RIDGE AXIS IS FORECAST TO PASS OVERHEAD TONIGHT
WITH A MOSTLY CLEAR SKY ANTICIPATED ALONG WITH A LIGHT SOUTHWEST
TO SOUTH WIND.
TEMPERATURES TONIGHT WILL BE RATHER MILD WITH LOWS MAINLY FROM
THE MIDDLE 50S TO THE LOWER 60S.
WITH DEW POINT TEMPERATURES ON THE RISE, THERE MAY BE SOME FOG
DEVELOPING OVER OUR COASTAL WATERS TONIGHT.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
ERLY IN THE EXTENDD PD, HIGH PRESSURE WILL BE OVER THE REGION
WITH AN AREA OF LOW PRES NR THE GRTLKS WILL MOVG EWD INTO SRN
CANADA AND A CDFNT WILL MOVE THRU THE REGION MONDAY NIGHT. ATTM,
IT APPEARS THE CDFNT WILL COME THRU DRY OR MOSTLY DRY. HIGH
PRESSURE THEN BUILDS BACK IN FOR TUESDAY THRU THURSDAY. ANOTHER
AREA OF LOW PRESSURE WILL MOVE BY TO THE NORTH THURSDAY NIGHT OR
FRIDAY MORNING BRINGING ANOTHER WK CDFNT THRU, WITH ANOTHER CHANCE
OF SOME SHOWERS ON FRIDAY. THEN, IT LOOKS LIKE A MORE ORGANIZED
CHANCE OF RAIN, AS A STORM ORGANIZES ACRS THE LWR MS VLY FRIDAY
NIGHT AND MOVES TO THE NE THRU THE WEEKEND. THERE ARE STILL TIMING
AND STRENGTH DIFFS WRT THIS SYS AS CAN BE EXPECTED WITH THIS TIME
SCALE. HOWEVER, ATTM IT LOOKS LIKE IT COULD BE THE MOST
SIGNIFICANT RAIN EVENT WE HAVE SEEN IN QUITE SOME TIME.
WITH THE HIGH PRESSURE IN CONTROL FOR MONDAY TEMPS LOOK TO BE
20-25 DEGREES ABOVE NRML AND WILL GRADUALLY DECREASE THRU THE WEEK
BUT WILL REMAIN ABOVE NRML THRU THE PD.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
ISOLATED LIGHT SHOWERS THIS MORNING HAVE ONLY A SMALL CHANCE OF
AFFECTING ANY INDIVIDUAL TAF SITE IN A TRANSIENT MANNER. CEILING
AND VISIBILITY VALUES THEREFORE ARE FORECAST TO REMAIN IN THE VFR
RANGE. OVERCAST TO BROKEN CLOUDS ABOVE 3500 FEET RANGE SHOULD
BECOME SCATTERED FOR THIS AFTERNOON WITH SOME CIRRUS OVERHEAD.
THE SKY IS EXPECTED TO BECOME MOSTLY CLEAR FOR TONIGHT. HOWEVER,
A FOG BANK MAY DEVELOP OVER OUR COASTAL WATERS. IT COULD DRIFT
INLAND A BIT, POSSIBLY AFFECTING KACY AND KMIV LATE TONIGHT.
FORECAST CONFIDENCE IS LOW REGARDING THE FOG, SO IT HAS NOT BEEN
INCLUDED IN THE TAFS AT THIS TIME.
A SOUTHWEST WIND AROUND 4 TO 8 KNOTS IS FORECAST TO INCREASE INTO
THE 8 TO 12 KNOT RANGE THIS AFTERNOON WITH GUSTS AROUND 20 KNOTS
POSSIBLE. THE SOUTHWEST WIND SHOULD DECREASE BACK INTO THE 4 TO 8
KNOT RANGE FOR TONIGHT.
OUTLOOK...
MONDAY THRU THURSDAY...VFR WITH HIGH PRESSURE IN CONTROL. SOME
BRIEF SHOWERS CAN NOT BE RULED OUT MONDAY NIGHT WITH THE PASSAGE
OF A WEAK CDFNT.
&&
.MARINE...
WAVES AT BUOYS 44009 AND 44065 HAD DROPPED IN EXCESS OF ONE FOOT
BELOW THE ADVISORY CRITERION THIS MORNING, AND SO THE ADVISORY FOR
ROUGH SEAS WAS CANCELLED.
A SOUTHWEST TO SOUTH WIND AT AROUND 10 KNOTS WILL PICK UP A BIT
ALONG THE IMMEDIATE COASTLINE BUT NOT FURTHER OUT THIS AFTERNOON.
THE AIR WILL WARM AND RIDE OVER THE COOL WATER, LESSENING THE
MIXING OF THE BOUNDARY LAYER. WAVE HEIGHTS ARE FORECAST IN THE 2
TO 4 FEET RANGE FOR THIS AFTERNOON ON OUR OCEAN WATERS. WE WILL
CONTINUE TO MONITOR THE TRENDS IN THE EVENT THAT THE FLOW BECOMES
SUFFICIENTLY SOUTH OF OFFSHORE TO CAUSE ANOTHER RISE.
MEANWHILE WIND SPEEDS AND GUSTS ARE FORECAST TO REMAIN BELOW 25
KNOTS INTO MONDAY. THE DIRECTION WILL CONTINUE TO FAVOR THE SOUTH
AND SOUTHWEST.
WITH DEW POINT TEMPERATURES ON THE RISE, THERE MAY BE SOME FOG
DEVELOPING OVER OUR COASTAL WATERS TONIGHT.
OUTLOOK...
HIGH PRESSURE WILL BE IN CONTROL TO START THE PD AND WINDS AND
SEAS WILL REMAIN BELOW CRITERIA. A WK CDFNT WILL CROSS THE REGION
MONDAY NIGHT AND SOME GUIDANCE IS INDICATING THAT SCA CRITERIA
WILL BE REACHED AT THAT TIME. HIGH PRESSURE THEN BUILDS BACK IN
FOR THE BALANCE OF THE WEEK WITH WINDS AND SEAS REMAINING BELOW
SCA CRITERIA. BY THURSDAY NIGHT OR FRIDAY ANOTHER COLD FRONT WILL
APPROACH AND WE COULD BE LOOKING AT MARGINAL SCA CONDS AGAIN, BUT
THE BEST CHANCE FOR SCA CRITERIA LOOKS TO BE OVER THE WEEKEND WHEN
A STRONGER STORM WILL IMPACT THE COASTAL WATERS.
&&
.FIRE WEATHER...
FINE FUELS REMAIN DRY WITH THE LITTLE BIT OF RAIN THAT HAS
OCCURRED. WIND AND RELATIVE HUMIDITY CONDITIONS SHOULD NOT COMBINE
TO CREATE ENHANCED FIRE WEATHER CONCERNS FOR TODAY. HOWEVER,
CONDITIONS MAY GET CLOSE IN PARTS OF OUR REGION AGAIN ON MONDAY.
&&
.CLIMATE...
WITH A MUCH WARMER AIR MASS MAKING ITS WAY TO OUR REGION FOR
EARLY NEXT WEEK, THERE IS THE POTENTIAL FOR SOME OF THE REGIONS
RECORD HIGH TEMPERATURES TO BE APPROACHED.
HERE ARE THE RECORD HIGH TEMPERATURES FOR ALL EIGHT OF OUR
CLIMATE SITES FOR MONDAY.
ALLENTOWN 89 - 2002
ATLANTIC CITY 89 - 2002
GEORGETOWN 89 - 2002
MOUNT POCONO 85 - 2002
PHILADELPHIA 90 - 2002
READING 88 - 2002
TRENTON 90 - 2002
WILMINGTON 92 - 1896
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NIERENBERG
NEAR TERM...DELISI/IOVINO/KLINE
SHORT TERM...IOVINO
LONG TERM...NIERENBERG
AVIATION...DELISI/IOVINO/NIERENBERG
MARINE...DELISI/IOVINO/NIERENBERG
FIRE WEATHER...IOVINO
CLIMATE...MEOLA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
511 PM CDT SUN APR 15 2012
.MESOSCALE DISCUSSION...
235 PM CDT
THE 18Z SOUNDINGS FROM DVN AND ILX BOTH SHOW A MUCH MORE STOUT
CAPPING INVERSION PRESENT THAN HAD BEEN FORECAST BY THE VARIOUS
MODELS. DESPITE FAIRLY EXTENSIVE AND IN SOME CASES DENSE
CIRRUS...SFC TEMPS CONTINUE TO WARM WHICH IS HELPING WEAKEN THE
BOUNDARY LAYER CONVECTIVE INHIBITION SOMEWHAT...THOUGH SERIES OF
ACARS SOUNDINGS OUT OF MDW SHOW EVIDENCE OF INCREASING MID LEVEL
SUBSIDENCE...LIKELY IN THE WAKE OF THE LEAD WAVE THAT PASSED BY THIS
MORNING.
SOME MOISTENING/COOLING HAS BEEN NOTED ON WATER VAPOR IMAGERY OVER
SOUTHERN MISSOURI LIKELY IN ASSOCIATION WITH INCREASING ASCENT WITH
APPROACHING MID/UPPER LEVEL JET ROUNDING THE BASE OF THE TROUGH.
GIVEN THE CAPPING IN PLACE SUSPECT THAT MORE THE ROBUST/WIDESPREAD
CONVECTION IN OUR AREA MAY END UP WAITING UNTIL THE ARRIVAL OF THIS
FORCING LATE THIS AFTERNOON INTO THIS EVENING. FORECAST SOUNDINGS
FROM THE RUC DO SUGGEST THAT THIS WILL OCCUR...SO THE THREAT STILL
IS THERE FOR SEVERE WEATHER IS STILL THIS EVENING.
ASSUMING MORE INTENSE CONVECTION DOES INDEED GET GOING IN THE AREA
THIS EVENING...ITS LOOKING MORE LIKELY THAT IT WILL BE A VERY HIGH
SHEAR/LOW CAPE TYPE ENVIRONMENT WITH MAINLY A DAMAGING WIND THREAT.
THOUGH AS ALLUDED TO IN THE PREVIOUS MESO-AFD...THE EXTREME SHEAR
DOES CERTAINLY RAISE CONCERNS ABOUT THE TORNADO POTENTIAL DESPITE
THE EXPECTED LIMITED INSTABILITY.
IZZI
&&
.DISCUSSION...
300 PM CDT
THE REMAINDER OF THE SHORT TERM...MONDAY THROUGH WEDNESDAY...
CONDITIONS WILL QUIET DOWN CONSIDERABLE FOLLOWING THE PASSAGE OF
THE COLD FRONT MONDAY MORNING. THERE IS A CHANCE FOR SOME WRAP
AROUND SHOWERS OVER THE NRN PORTIONS OF THE CWA MONDAY AFTERNOON
AS THE LOW PRESSURE SYSTEM EXITS TO THE NORTHEAST...BUT ANY PCPN
WOULD LIKELY BE ONLY SOME LIGHT RAIN SHOWERS. STRONG COLD
ADVECTION WILL SET UP FOLLOWING THE FROPA...SO THERE SHOULD BE
LITTLE DIURNAL WARMING THROUGH THE DAY WITH TEMPERATURES REMAINING
STEADY IN THE MIDDLE 50S TO LOWER 60S THROUGH THE DAY. THROUGH THE
EVENING AND INTO THE OVERNIGHT HOURS...COOL HIGH PRESSURE WILL
BUILD OUT OF THE PLAINS AND INTO THE AREA...WITH THE HIGH PRESSURE
SPREADING INTO THE OHIO VALLEY BY TUESDAY MORNING. CLEARING SKIES
AND DECREASING WINDS...COINCIDENT WITH SHARPLY LOWER DEWPOINTS
WILL SET UP A SCENARIO FOR STRONG RADIATIVE COOLING...WITH MUCH OF
THE CWA NORTH OF THE ILLINOIS/KANKAKEE RIVER VALLEYS SEEING
TEMPERATURES DROPPING TO AS LOW AS 34-35 DEGREES. THIS SHOULD
ALLOW FOR AT LEAST PATCHY FROST TO FORM DURING THE EARLY MORNING
HOURS. AT THIS POINT...DO NOT SEE TEMPERATURES DROPPING INTO THE
LOWER 30S...SO A FREEZE IS NOT EXPECTED. THE URBANIZED AREAS OF
THE CHICAGO METRO AREA AND LOCATIONS INVOF LAKE MICHIGAN SHOULD
REMAIN A BIT WARMER WITH TEMPERATURES REMAINING IN THE UPPER 30S
TO ARND 40F...SO NO FROST IS LIKELY THERE. THE REMAINDER OF
TUESDAY SHOULD BE DRY WITH NELY WINDS SETTING UP AS THE HIGH
PASSES OFF TO THE EAST. THE ONSHORE FLOW OFF OF LAKE MICHIGAN WILL
KEEP LAKEFRONT LOCATIONS RATHER COOL...WITH HIGHS ONLY IN THE
UPPER 40S TO LOWER 50S...BUT AMPLE SUNSHINE WILL ALLOW THE
REMAINDER OF THE AREA TO WARM UP INTO THE UPPER 50S TO LOWER 60S.
TUESDAY NIGHT AND INTO WEDNESDAY SHOULD SEE A RETURN TO MORE
SOUTHERLY FLOW AS THE HIGH CONTINUES EWD AND THE NEXT UPSTREAM
SYSTEM DROPS OUT OF THE NRN ROCKIES AND TRACKS ACROSS THE NRN PLAINS
TO THE UPPER GREAT LAKES. THE LATEST GFS/ECMWF ARE IN QUITE GOOD
AGREEMENT ON HANDLING THIS SYSTEM AND ARE TRENDING A LITTLE SLOWER
THAN THE NAM SOLUTION. FOR THE END OF THE SHORT TERM FORECAST
PERIOD AND INTO THE LONG TERM PERIOD...FROM WEDNESDAY AND THROUGH
THE WEEKEND...HAVE GENERALLY FOLLOWED FAIRLY CLOSELY TO THE
GFS/ECMWF PATTERN. THIS SOLUTIONS BRINGS THE NEXT SIGNIFICANT
CHANCE OF PCPN TO THE AREA WEDNESDAY AFTERNOON AND EVENING. THIS
RESPONSIBLE SYSTEM WILL BE A NRN STREAM SYSTEM...ALMOST
CLIPPER-LIKE...TRACKING THROUGH THE UPPER MISSISSIPPI VALLEY AND
UPPER GREAT LAKES REGIONS. A TRAILING WEAK COLD FRONT SHOULD SWEEP
THROUGH THE CWA LATE WEDNESDAY AFTERNOON...BRINGING SHOWERS AND
PERHAPS A CHANCE FOR A FEW THUNDERSTORMS...BUT THIS SYSTEM WILL BE
RATHER QUICK-MOVING SO THE WINDOW OF OPPORTUNITY FOR THUNDER WILL BE
FAIRLY SHORT...AND THERE SHOULD BE LITTLE OR NO POTENTIAL FOR ANY
SEVERE WEATHER WITH THIS SYSTEM. THERE MAY BE ANOTHER CHANCE FOR
SOME RAIN OVER THE AREA BY THURSDAY NIGHT OR FRIDAY AS A SOUTHERN
STREAM SYSTEM LIFTS OUT OF THE SRN PLAINS. THE MODELS ARE SHOWING A
BIT MORE OF A SPREAD IN THE TRACK OF THIS SYSTEM WITH THE ECMWF
ADVERTISING A FASTER...MORE NORTHERLY TRACK THROUGH NRN
IL/IN/OH...WHILE THE GFS IS A BIT INDICATES A SLOWER...MORE
SOUTHERLY TRACK THROUGH THE OHIO VALLEY. A QUICK LOOK AT THE GEM
SPLITS THE DIFFERENCE BETWEEN THE GFS/ECMWF TRACKS...SO THE PATH OF
LEAST RESISTANCE AT THIS POINT HAS BEEN TO GO WITH THE MORE MIDDLE
OF THE ROAD APPROACH. ANY OF THESE SCENARIOS WOULD BRING SOME RAIN
TO THE CWA...BUT ANY THUNDERSTORM POTENTIAL WOULD BE MORE DIRECTLY
IMPACTED BY THE EXACT PATH OF THE SYSTEM. SO HAVE INDICATED A
SLIGHT CHANCE FOR SOME THUNDER ON THURSDAY...BUT CONFIDENCE IS NOT
VERY HIGH ON THIS POTENTIAL.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* BRIEF PERIOD OF SHOWERS AND MAYBE A RUMBLE OF THUNDER AROUND 23
UTC AT KMDW AS SOME SHOWERS QUICKLY MOVE ACROSS THE AREA.
* ADDITIONAL TSRA MOVING THROUGH THE TERMINALS THIS EVENING.
PERIODS OF HEAVY RAIN...HAIL...FREQUENT LIGHTNING...AND BRIEF
IFR VIS POSSIBLE.
* STRONG SOUTH WINDS GUSTING TO 30-35 KT INTO THE EVENING...NOT
ASSOCIATED WITH THUNDERSTORMS.
IZZI/KB
//DISCUSSION...UPDATED 18Z...
STRONG LOW PRESSURE CENTER MOVING INTO MINNESOTA BY THIS EVENING
WILL SUPPORT REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS BY THIS
EVENING. THE MOST FAVORABLE AREA FOR REDEVELOPMENT IS TO THE WEST
OF THE TERMINALS...AND THEN MOVING EAST THROUGH THE EVENING. LOW
LEVEL SOUTH-SOUTHWEST WINDS ASSOCIATED WITH THE LOW WILL GUST INTO
THE 30-35 KT RANGE AT TIMES DURING THE AFTERNOON AND EVENING.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM CONFIDENCE ON TIMING TS MOVING THROUGH THIS EVENING.
* MEDIUM TO HIGH CONFIDENCE ON WIND TRENDS.
IZZI/KB
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...
TUESDAY...VFR.
WEDNESDAY...VFR. CHC MVFR CIGS W/SHRA ISO TSRA
MIDDAY/AFTN.
THURSDAY...VFR. CHC SHRA.
FRIDAY...VFR. CHC SHRA ISO TSRA.
SATURDAY...VFR. CHC SHRA.
LENNING
&&
.MARINE...
257 PM...STRONG LOW PRESSURE ACROSS THE PLAINS THIS AFTERNOON WILL
MOVE NORTHEAST ACROSS THE NORTHERN LAKES MONDAY MORNING AND INTO
QUEBEC MONDAY NIGHT. AS THIS LOW APPROACHES...A WARM FRONT CURRENTLY
OVER NORTHERN LAKE MICHIGAN WILL LIFT NORTH OF THE LAKE...WITH
SOUTHEAST WINDS TURNING MORE SOUTHERLY. DENSE FOG ALONG AND AHEAD
OF THIS FRONT SHOULD IMPROVE ONCE WINDS TURN SOUTHERLY.
WHILE THE GRADIENT WILL CONTINUE TO TIGHTEN AS THE LOW APPROACHES...
A VERY STABLE MARINE LAYER SHOULD PREVENT WINDS FROM INCREASING MUCH
ABOVE 30 KTS OVER THE OPEN WATERS...PERHAPS A FEW HIGHER GUSTS AT
TIMES. OFFSHORE FLOW FROM DEEPER MIXING OVER LAND WILL STILL SUPPORT
FREQUENT GALES IN THE ILLINOIS AND INDIANA NEARSHORE WATERS AND HAVE
EXTENDED THE GALE WARNING FOR THE ILLINOIS/INDIANA NEARSHORE WATERS
THROUGH MONDAY AFTERNOON. AND AT THIS TIME...HAVE MAINTAINED THE
GALE WATCH FOR THE OPEN WATERS. WHILE GALES STILL LOOK POSSIBLE OVER
THE NORTHERN PART OF THE LAKE LATE MONDAY AFTERNOON INTO MONDAY
EVENING...BY THE TIME THE MARINE LAYER WEAKENS DUE TO COLDER AIR
ARRIVING...THE WINDS ALOFT ARE 30 KTS OR LESS. THE POTENTIAL FOR
GALE FORCE WINDS STILL EXISTS...BUT CONFIDENCE IS FAIRLY LOW OVER
SOUTHERN LAKE MICHIGAN. WINDS SHOULD DIMINISH QUICKLY MONDAY
NIGHT INTO TUESDAY MORNING AS HIGH PRESSURE BECOMES CENTERED OVER
THE LAKE BY MIDDAY TUESDAY...WITH LAKE BREEZES LIKELY ALONG ALL OF
THE SHORES OF LAKE MICHIGAN. THIS HIGH QUICKLY MOVES EAST TUESDAY
NIGHT WITH LOW PRESSURE LIFTING NORTHEAST ACROSS THE UPPER MIDWEST
AND EVENTUALLY THE NORTHERN LAKES ON WEDNESDAY...WHICH WILL
TIGHTEN A SOUTHERLY GRADIENT WITH WINDS TO 30 KTS POSSIBLE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 1 AM MONDAY.
IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 1 AM
MONDAY.
LM...GALE WATCH...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...10 AM MONDAY TO 9 PM
MONDAY.
DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ563 UNTIL 7 PM
SUNDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 PM MONDAY TO 1 AM TUESDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 7
PM MONDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
303 PM CDT SUN APR 15 2012
.MESOSCALE DISCUSSION...
235 PM CDT
THE 18Z SOUNDINGS FROM DVN AND ILX BOTH SHOW A MUCH MORE STOUT
CAPPING INVERSION PRESENT THAN HAD BEEN FORECAST BY THE VARIOUS
MODELS. DESPITE FAIRLY EXTENSIVE AND IN SOME CASES DENSE
CIRRUS...SFC TEMPS CONTINUE TO WARM WHICH IS HELPING WEAKEN THE
BOUNDARY LAYER CONVECTIVE INHIBITION SOMEWHAT...THOUGH SERIES OF
ACARS SOUNDINGS OUT OF MDW SHOW EVIDENCE OF INCREASING MID LEVEL
SUBSIDENCE...LIKELY IN THE WAKE OF THE LEAD WAVE THAT PASSED BY THIS
MORNING.
SOME MOISTENING/COOLING HAS BEEN NOTED ON WATER VAPOR IMAGERY OVER
SOUTHERN MISSOURI LIKELY IN ASSOCIATION WITH INCREASING ASCENT WITH
APPROACHING MID/UPPER LEVEL JET ROUNDING THE BASE OF THE TROUGH.
GIVEN THE CAPPING IN PLACE SUSPECT THAT MORE THE ROBUST/WIDESPREAD
CONVECTION IN OUR AREA MAY END UP WAITING UNTIL THE ARRIVAL OF THIS
FORCING LATE THIS AFTERNOON INTO THIS EVENING. FORECAST SOUNDINGS
FROM THE RUC DO SUGGEST THAT THIS WILL OCCUR...SO THE THREAT STILL
IS THERE FOR SEVERE WEATHER IS STILL THIS EVENING.
ASSUMING MORE INTENSE CONVECTION DOES INDEED GET GOING IN THE AREA
THIS EVENING...ITS LOOKING MORE LIKELY THAT IT WILL BE A VERY HIGH
SHEAR/LOW CAPE TYPE ENVIRONMENT WITH MAINLY A DAMAGING WIND THREAT.
THOUGH AS ALLUDED TO IN THE PREVIOUS MESO-AFD...THE EXTREME SHEAR
DOES CERTAINLY RAISE CONCERNS ABOUT THE TORNADO POTENTIAL DESPITE
THE EXPECTED LIMITED INSTABILITY.
IZZI
&&
.DISCUSSION...
300 PM CDT
THE REMAINDER OF THE SHORT TERM...MONDAY THROUGH WEDNESDAY...
CONDITIONS WILL QUIET DOWN CONSIDERABLE FOLLOWING THE PASSAGE OF
THE COLD FRONT MONDAY MORNING. THERE IS A CHANCE FOR SOME WRAP
AROUND SHOWERS OVER THE NRN PORTIONS OF THE CWA MONDAY AFTERNOON
AS THE LOW PRESSURE SYSTEM EXITS TO THE NORTHEAST...BUT ANY PCPN
WOULD LIKELY BE ONLY SOME LIGHT RAIN SHOWERS. STRONG COLD
ADVECTION WILL SET UP FOLLOWING THE FROPA...SO THERE SHOULD BE
LITTLE DIURNAL WARMING THROUGH THE DAY WITH TEMPERATURES REMAINING
STEADY IN THE MIDDLE 50S TO LOWER 60S THROUGH THE DAY. THROUGH THE
EVENING AND INTO THE OVERNIGHT HOURS...COOL HIGH PRESSURE WILL
BUILD OUT OF THE PLAINS AND INTO THE AREA...WITH THE HIGH PRESSURE
SPREADING INTO THE OHIO VALLEY BY TUESDAY MORNING. CLEARING SKIES
AND DECREASING WINDS...COINCIDENT WITH SHARPLY LOWER DEWPOINTS
WILL SET UP A SCENARIO FOR STRONG RADIATIVE COOLING...WITH MUCH OF
THE CWA NORTH OF THE ILLINOIS/KANKAKEE RIVER VALLEYS SEEING
TEMPERATURES DROPPING TO AS LOW AS 34-35 DEGREES. THIS SHOULD
ALLOW FOR AT LEAST PATCHY FROST TO FORM DURING THE EARLY MORNING
HOURS. AT THIS POINT...DO NOT SEE TEMPERATURES DROPPING INTO THE
LOWER 30S...SO A FREEZE IS NOT EXPECTED. THE URBANIZED AREAS OF
THE CHICAGO METRO AREA AND LOCATIONS INVOF LAKE MICHIGAN SHOULD
REMAIN A BIT WARMER WITH TEMPERATURES REMAINING IN THE UPPER 30S
TO ARND 40F...SO NO FROST IS LIKELY THERE. THE REMAINDER OF
TUESDAY SHOULD BE DRY WITH NELY WINDS SETTING UP AS THE HIGH
PASSES OFF TO THE EAST. THE ONSHORE FLOW OFF OF LAKE MICHIGAN WILL
KEEP LAKEFRONT LOCATIONS RATHER COOL...WITH HIGHS ONLY IN THE
UPPER 40S TO LOWER 50S...BUT AMPLE SUNSHINE WILL ALLOW THE
REMAINDER OF THE AREA TO WARM UP INTO THE UPPER 50S TO LOWER 60S.
TUESDAY NIGHT AND INTO WEDNESDAY SHOULD SEE A RETURN TO MORE
SOUTHERLY FLOW AS THE HIGH CONTINUES EWD AND THE NEXT UPSTREAM
SYSTEM DROPS OUT OF THE NRN ROCKIES AND TRACKS ACROSS THE NRN PLAINS
TO THE UPPER GREAT LAKES. THE LATEST GFS/ECMWF ARE IN QUITE GOOD
AGREEMENT ON HANDLING THIS SYSTEM AND ARE TRENDING A LITTLE SLOWER
THAN THE NAM SOLUTION. FOR THE END OF THE SHORT TERM FORECAST
PERIOD AND INTO THE LONG TERM PERIOD...FROM WEDNESDAY AND THROUGH
THE WEEKEND...HAVE GENERALLY FOLLOWED FAIRLY CLOSELY TO THE
GFS/ECMWF PATTERN. THIS SOLUTIONS BRINGS THE NEXT SIGNIFICANT
CHANCE OF PCPN TO THE AREA WEDNESDAY AFTERNOON AND EVENING. THIS
RESPONSIBLE SYSTEM WILL BE A NRN STREAM SYSTEM...ALMOST
CLIPPER-LIKE...TRACKING THROUGH THE UPPER MISSISSIPPI VALLEY AND
UPPER GREAT LAKES REGIONS. A TRAILING WEAK COLD FRONT SHOULD SWEEP
THROUGH THE CWA LATE WEDNESDAY AFTERNOON...BRINGING SHOWERS AND
PERHAPS A CHANCE FOR A FEW THUNDERSTORMS...BUT THIS SYSTEM WILL BE
RATHER QUICK-MOVING SO THE WINDOW OF OPPORTUNITY FOR THUNDER WILL BE
FAIRLY SHORT...AND THERE SHOULD BE LITTLE OR NO POTENTIAL FOR ANY
SEVERE WEATHER WITH THIS SYSTEM. THERE MAY BE ANOTHER CHANCE FOR
SOME RAIN OVER THE AREA BY THURSDAY NIGHT OR FRIDAY AS A SOUTHERN
STREAM SYSTEM LIFTS OUT OF THE SRN PLAINS. THE MODELS ARE SHOWING A
BIT MORE OF A SPREAD IN THE TRACK OF THIS SYSTEM WITH THE ECMWF
ADVERTISING A FASTER...MORE NORTHERLY TRACK THROUGH NRN
IL/IN/OH...WHILE THE GFS IS A BIT INDICATES A SLOWER...MORE
SOUTHERLY TRACK THROUGH THE OHIO VALLEY. A QUICK LOOK AT THE GEM
SPLITS THE DIFFERENCE BETWEEN THE GFS/ECMWF TRACKS...SO THE PATH OF
LEAST RESISTANCE AT THIS POINT HAS BEEN TO GO WITH THE MORE MIDDLE
OF THE ROAD APPROACH. ANY OF THESE SCENARIOS WOULD BRING SOME RAIN
TO THE CWA...BUT ANY THUNDERSTORM POTENTIAL WOULD BE MORE DIRECTLY
IMPACTED BY THE EXACT PATH OF THE SYSTEM. SO HAVE INDICATED A
SLIGHT CHANCE FOR SOME THUNDER ON THURSDAY...BUT CONFIDENCE IS NOT
VERY HIGH ON THIS POTENTIAL.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* TSRA MOVING THROUGH THE TERMINALS THIS EVENING. PERIODS OF HEAVY
RAIN...HAIL...FREQUENT LIGHTNING...AND BRIEF IFR VIS POSSIBLE.
* STRONG SOUTH-SOUTHWEST WINDS GUSTING TO 30-35 KT THROUGH THE DAY
AND INTO THE EVENING...NOT ASSOCIATED WITH THUNDERSTORMS.
IZZI
//DISCUSSION...UPDATED 18Z...
STRONG LOW PRESSURE CENTER MOVING INTO MINNESTOA BY THIS EVENING
WILL SUPPORT REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS BY THIS
EVENING. THE MOST FAVORABLE AREA FOR REDEVELOPMENT IS TO THE WEST
OF THE TERMINALS...AND THEN MOVING EAST THROUGH THE EVENING. LOW
LEVEL SOUTH-SOUTHWEST WINDS ASSOCIATED WITH THE LOW WILL GUST INTO
THE 30-35 KT RANGE AT TIMES DURING THE AFTERNOON AND EVENING.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN NO PRECIPITATION THROUGH THE AFTERNOON.
* MEDIUM CONFIDENCE ON TIMING TS MOVING THROUGH THIS EVENING.
* MEDIUM TO HIGH CONFIDENCE ON WIND TRENDS.
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...
TUESDAY...VFR.
WEDNESDAY...VFR. CHC MVFR CIGS W/SHRA ISO TSRA
MIDDAY/AFTN.
THURSDAY...VFR. CHC SHRA.
FRIDAY...VFR. CHC SHRA ISO TSRA.
SATURDAY...VFR. CHC SHRA.
LENNING
&&
.MARINE...
257 PM...STRONG LOW PRESSURE ACROSS THE PLAINS THIS AFTERNOON WILL
MOVE NORTHEAST ACROSS THE NORTHERN LAKES MONDAY MORNING AND INTO
QUEBEC MONDAY NIGHT. AS THIS LOW APPROACHES...A WARM FRONT CURRENTLY
OVER NORTHERN LAKE MICHIGAN WILL LIFT NORTH OF THE LAKE...WITH
SOUTHEAST WINDS TURNING MORE SOUTHERLY. DENSE FOG ALONG AND AHEAD
OF THIS FRONT SHOULD IMPROVE ONCE WINDS TURN SOUTHERLY.
WHILE THE GRADIENT WILL CONTINUE TO TIGHTEN AS THE LOW APPROACHES...
A VERY STABLE MARINE LAYER SHOULD PREVENT WINDS FROM INCREASING MUCH
ABOVE 30 KTS OVER THE OPEN WATERS...PERHAPS A FEW HIGHER GUSTS AT
TIMES. OFFSHORE FLOW FROM DEEPER MIXING OVER LAND WILL STILL SUPPORT
FREQUENT GALES IN THE ILLINOIS AND INDIANA NEARSHORE WATERS AND HAVE
EXTENDED THE GALE WARNING FOR THE ILLINOIS/INDIANA NEARSHORE WATERS
THROUGH MONDAY AFTERNOON. AND AT THIS TIME...HAVE MAINTAINED THE
GALE WATCH FOR THE OPEN WATERS. WHILE GALES STILL LOOK POSSIBLE OVER
THE NORTHERN PART OF THE LAKE LATE MONDAY AFTERNOON INTO MONDAY
EVENING...BY THE TIME THE MARINE LAYER WEAKENS DUE TO COLDER AIR
ARRIVING...THE WINDS ALOFT ARE 30 KTS OR LESS. THE POTENTIAL FOR
GALE FORCE WINDS STILL EXISTS...BUT CONFIDENCE IS FAIRLY LOW OVER
SOUTHERN LAKE MICHIGAN. WINDS SHOULD DIMINISH QUICKLY MONDAY
NIGHT INTO TUESDAY MORNING AS HIGH PRESSURE BECOMES CENTERED OVER
THE LAKE BY MIDDAY TUESDAY...WITH LAKE BREEZES LIKELY ALONG ALL OF
THE SHORES OF LAKE MICHIGAN. THIS HIGH QUICKLY MOVES EAST TUESDAY
NIGHT WITH LOW PRESSURE LIFTING NORTHEAST ACROSS THE UPPER MIDWEST
AND EVENTUALLY THE NORTHERN LAKES ON WEDNESDAY...WHICH WILL
TIGHTEN A SOUTHERLY GRADIENT WITH WINDS TO 30 KTS POSSIBLE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 1 AM MONDAY.
IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 1 AM
MONDAY.
LM...GALE WATCH...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...10 AM MONDAY TO 9 PM
MONDAY.
DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ563 UNTIL 7 PM
SUNDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 PM MONDAY TO 1 AM TUESDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 7
PM MONDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
247 PM CDT SUN APR 15 2012
.MESOSCALE DISCUSSION...
235 PM CDT
THE 18Z SOUNDINGS FROM DVN AND ILX BOTH SHOW A MUCH MORE STOUT
CAPPING INVERSION PRESENT THAN HAD BEEN FORECAST BY THE VARIOUS
MODELS. DESPITE FAIRLY EXTENSIVE AND IN SOME CASES DENSE
CIRRUS...SFC TEMPS CONTINUE TO WARM WHICH IS HELPING WEAKEN THE
BOUNDARY LAYER CONVECTIVE INHIBITION SOMEWHAT...THOUGH SERIES OF
ACARS SOUNDINGS OUT OF MDW SHOW EVIDENCE OF INCREASING MID LEVEL
SUBSIDENCE...LIKELY IN THE WAKE OF THE LEAD WAVE THAT PASSED BY THIS
MORNING.
SOME MOISTENING/COOLING HAS BEEN NOTED ON WATER VAPOR IMAGERY OVER
SOUTHERN MISSOURI LIKELY IN ASSOCIATION WITH INCREASING ASCENT WITH
APPROACHING MID/UPPER LEVEL JET ROUNDING THE BASE OF THE TROUGH.
GIVEN THE CAPPING IN PLACE SUSPECT THAT MORE THE ROBUST/WIDESPREAD
CONVECTION IN OUR AREA MAY END UP WAITING UNTIL THE ARRIVAL OF THIS
FORCING LATE THIS AFTERNOON INTO THIS EVENING. FORECAST SOUNDINGS
FROM THE RUC DO SUGGEST THAT THIS WILL OCCUR...SO THE THREAT STILL
IS THERE FOR SEVERE WEATHER IS STILL THIS EVENING.
ASSUMING MORE INTENSE CONVECTION DOES INDEED GET GOING IN THE AREA
THIS EVENING...ITS LOOKING MORE LIKELY THAT IT WILL BE A VERY HIGH
SHEAR/LOW CAPE TYPE ENVIRONMENT WITH MAINLY A DAMAGING WIND THREAT.
THOUGH AS ALLUDED TO IN THE PREVIOUS MESO-AFD...THE EXTREME SHEAR
DOES CERTAINLY RAISE CONCERNS ABOUT THE TORNADO POTENTIAL DESPITE
THE EXPECTED LIMITED INSTABILITY.
IZZI
&&
.DISCUSSION...
1026 AM CDT
VERY DEEP //989MB// SFC LOW OVER CENTRAL NEBRASKA WILL CONTINUE TO
LIFT NORTHEAST TOWARD THE UPPER MISSISSIPPI VALLEY THROUGH
TONIGHT. PRESSURE GRADIENT AROUND THIS LOW HAS ALREADY RESULTED IN
WINDS GUSTING TO BETWEEN 30 AND 40 MPH THIS MORNING. WINDS SHOULD
CONTINUE TO INCREASE THIS AFTERNOON WITH SOME MIXED SUNSHINE AND
HEATING/MIXING...AND WHILE WE WILL SEE SOME DIURNAL SLACKENING OF
THE WINDS JUST OF THE DECK STILL THINK GUSTS OVER 40 MPH COULD
OCCUR THIS AFTERNOON. BY THIS EVENING SHOULD SEE WINDS JUST OFF
THE DECK RAPIDLY INCREASE TO 50-60KT 2000FT AGL AS EARLY AS 00Z
AND WITH STRONG PRESSURE FALLS/ISALOBARIC PUSH MAY SEE VERY LITTLE
DECOUPLING THIS EVENING WITH SURFACE WINDS PROBABLY INCREASING
EVEN FURTHER THIS EVENING. GIVEN THIS POTENTIAL HAVE OPTED TO
HOIST A WIND ADVISORY THROUGH 06Z FOR THE ENTIRE CWA.
WILL SHOOT TO HAVE A CONVECTIVE MESOSCALE AFD ISSUED PRIOR TO 17Z.
IZZI
//PREV DISCUSSION...
345 AM CDT
THE BULK OF THE OVERNIGHT SHOWER AND THUNDERSTORM ACTIVITY WILL BE
ON THE WANE AS WE APPROACH SUNRISE...WITH THE OVERALL ORIENTATION OF
THE REFLECTIVITY RETURNS TO SHIFT TO THE NORTHEAST AND EVENTUALLY
OUT OF THE CWA BY THE EARLY MORNING HOURS AS A SHORTWAVE SHOOTS OFF
TO MICHIGAN. HIGH RESOLUTION GUIDANCE HAD A DIFFICULT TIME DEALING
WITH SMALL SCALE FEATURES TONIGHT...AND NOTHING CAUGHT AN MCV
CHARGING EAST OUT OF KANSAS. IT WAS WITH THIS AREA THAT AN
IMPRESSIVE SQUALL WAS CHARGING THROUGH...PLOWING INTO IOWA AND
EVENTUALLY ACROSS OUR AREA. BY THE TIME IT HIT NORTH CENTRAL AND
NORTHEASTERN ILLINOIS...IT WEAKENED CONSIDERABLY AS THE ATMOSPHERE
WEST OF THE MISSISSIPPI WAS MUCH MORE PRIMED WHEN COMPARED TO
ACROSS THE CWA. HOWEVER...SPC ANALYSIS OF H8 MOISTURE TRANSPORT IS
INCREDIBLE AND WAS HELPING TO ADVECT IN HIGH PRECIPITABLE WATER
INTO THE AREA AND ALSO HELP TO PUSH SOME INSTABILITY ACROSS.
THE MAIN SURFACE LOW RESPONSIBLE FOR THE CURRENT WEATHER
SITUATION ACROSS THE PLAINS WILL LIFT NORTHEAST AND THROUGH
WISCONSIN BY THIS AFTERNOON. SOUTH OF THIS LOW IS A COLD FRONT
THAT WILL SWEEP ACROSS NORTHERN ILLINOIS AND NORTHWESTERN INDIANA
IN THE EVENING HOURS AND BRING THE NEXT CHANCES FOR SHOWERS AND
THUNDERSTORMS. THERE ARE A LOT OF LITTLE THINGS THAT WILL GO INTO
HOW THE FORECAST WILL PAN OUT TODAY AND TONIGHT. TO
BEGIN...AFTERNOON HIGHS WILL BE IN JEOPARDY DUE TO POTENTIAL CLOUD
COVER AND THE AMOUNT OF MIXING THAT WILL TAKE PLACE. NOT TO SOLD
ON THE FACT THAT AREAS WILL SEE FULL SUNSHINE THROUGH THE
DAY...OTHER THAN POCKETS OF BLUE. WITH THE OVERNIGHT
RAINFALL...GENERALLY THAT FELL NORTH OF I-80...THINK IT WILL TAKE
A LITTLE BIT OF TIME TO WARM...AND THAT AREAS TO THE SOUTH SHOULD
STILL SEE THE WARMEST OF TEMPS...AND THEY MAY BE UNDERDONE AS A
DRY SLOT MOVES THROUGH. LOW LEVEL FLOW WILL BE CONSIDERABLE INTO
THE AFTERNOON HOURS...AND AM ON THE FENCE WITH RESPECT TO A
POTENTIAL ADVISORY. EXPECT WINDS TO INCREASE INTO THIS AFTERNOON IN
THE WARM SECTOR AND COULD FORESEE GUSTS APPROACHING 40-45 MPH INTO
THE AFTERNOON. TECHNICAL CRITERIA FOR AN ADVISORY IS TO SEE
SUSTAINED WINDS OF 30 TO 39 MPH LASTING AN HOUR OR LONGER OR WINDS
OF 45 TO 57 MPH FOR ANY DURATION. WHILE FORECAST SOUNDINGS
INDICATE THAT THE AREA SHOULD BE MIXING UP TO H9 TO H85...AND SHOW
THE TOP OF THE MIXED CHANNEL HITTING MID TO UPPER 40 TO 50 KT
RANGE...STILL HAVING A HARD TIME SEEING COMPLETELY EFFICIENT
MIXING HAPPENING UNDER THE MOIST WARM ADVECTION REGIME. WILL HIT
WORDING AT THE UPPER NON ADVISORY THRESHOLD...AND DETAIL A BIT IN
THE HWO AS WELL.
EARLY EVENING HOURS THEN WILL BE THE MAIN EVENT FOR ACTIVITY ACROSS
THE AREA AS A COLD FRONT WILL BRING THE NEXT CHANCE FOR STRONG TO
POSSIBLY SEVERE STORMS TO THE ENTIRE AREA. SOUNDINGS FOR THE
CHICAGO AREA LOOK...SLOPPY INTO THE AFTERNOON AND EVENING HOURS
THOUGH THERE IS AN INDICATION THAT WE WILL BE MILDLY CAPPED WITH
THE INCREDIBLE WAA ONGOING. EVENTUALLY THE AREA WILL BECOME
UNSTABLE AND GUIDANCE IS INDICATING THAT CAPE VALUES OF BETWEEN
600-1000 J/KG ACROSS OUR EAST...WITH 1000-1200 J/KG WEST WILL BE
ON HAND TO START OUT. BASICALLY UNIDIRECTIONAL SHEAR WILL BE IN
PLACE AND EARLY MORNING INDICATIONS OF 0-1 BLK SHEAR VALUES OF
30-35 KT AND 0-6 VALUES OF 45 TO 50 KT WILL INCREASE TO NEAR 60 KT
IN THE EVENING AND WILL SUPPORT SEMI DISCREET CELLULAR ACTIVITY.
DESPITE THE LOW WEAKENING INTO THE EVENING AND BEING SO FAR
DISPLACED FROM OUR AREA...STILL ANTICIPATE SOME OF THE STORMS TO
APPROACH AND BECOME SEVERE AS THE FRONT RIPS THROUGH. GENERALLY
EXPECT RAPID DEVELOPMENT OF THUNDERSTORMS ACROSS SOUTHEASTERN IA
AND NORTHWESTERN MISSOURI BY THE EARLY AFTERNOON HOURS....WITH
ACTIVITY SHIFTING EAST THROUGH THE EVENING AND IMPACTING THE
CHICAGO METRO IN OR AROUND THE AROUND THE 7PM HOUR. THE BIGGEST
THREAT FOR ANY SEVERE ACTIVITY TOMORROW WILL BE HAIL AND DAMAGING
WINDS. AT THIS POINT AN ISOLATED TORNADO THREAT DOES EXIST AT
LEAST FOR A TIME GIVEN THE LOW LEVEL WIND FIELDS AND POTENTIAL FOR
GOOD LOW LEVEL INSTABILITY...BUT THE INCREASED LIKELIHOOD WILL BE
TIED CLOSER TO THE SURFACE LOW AND WARM FRONTAL INTERSECTION MORE
IN THE VICINITY OF LA CROSS. THAT SAID...ANY POTENTIAL BOUNDARY
THAT IS KICKED OUT BY DECAYING STORMS...MAY MODIFY THE WIND FIELD
ENOUGH FOR TORNADOGENESIS TO TAKE PLACE. ANY ACTIVITY SHOULD EXIT
THE AREA BY OR DURING THE OVERNIGHT HOURS. SPC`S DAY 1 OUTLOOK HAS
SHIFTED THE MODERATE BOX A LITTLE TO THE SOUTH AS THE MAIN SURFACE
LOW IS NOT MOVING AS QUICKLY AS MODELS PROGGED IT OVER THE LAST
FEW DAYS.
BEYOND THE TS ACTIVITY INTO THE EVENING...IT WILL TAKE SOME TIME FOR
WINDS TO SHIFT TO THE WEST AND FOR THE DRYING TO COMMENCE. WITH THE
LINGERING CLOUD COVER AND LIMITED COLDER AIR ADVECTION...MOST AREAS
SHOULD STAY RELATIVELY WARM TONIGHT AND INTO SUNDAY MORNING...WITH
OVERNIGHT LOWS ONLY FALLING TO THE MID 50S GENERALLY EAST OF I
57...AND A FEW DEGREES COOLER WEST AND NORTH.
NOT MUCH TIME TO GET DETAILED IN THE EXTENDED FORECAST WITH THE
ONGOING STORMS LAST NIGHT AND ACTIVE PERIOD EXPECTED TONIGHT. THE
MAIN UPPER TROUGH WILL MOVE EAST AND RIDGING WILL GRADUALLY SLIDE
OVER...BRINGING ANOTHER COOL DOWN BY MID WEEK. GUIDANCE IS STILL
AT ODDS WITH HOW THE END OF THE WEEK WILL PAN OUT...BUT CHANCES
FOR FROST LOOK GOOD NORTH OF I-88 MONDAY NIGHT AND INTO TUESDAY AS
OVERNIGHT LOWS TUMBLE. SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* TSRA MOVING THROUGH THE TERMINALS THIS EVENING. PERIODS OF HEAVY
RAIN...HAIL...FREQUENT LIGHTNING...AND BRIEF IFR VIS POSSIBLE.
* STRONG SOUTH-SOUTHWEST WINDS GUSTING TO 30-35 KT THROUGH THE DAY
AND INTO THE EVENING...NOT ASSOCIATED WITH THUNDERSTORMS.
IZZI
//DISCUSSION...UPDATED 18Z...
STRONG LOW PRESSURE CENTER MOVING INTO MINNESTOA BY THIS EVENING
WILL SUPPORT REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS BY THIS
EVENING. THE MOST FAVORABLE AREA FOR REDEVELOPMENT IS TO THE WEST
OF THE TERMINALS...AND THEN MOVING EAST THROUGH THE EVENING. LOW
LEVEL SOUTH-SOUTHWEST WINDS ASSOCIATED WITH THE LOW WILL GUST INTO
THE 30-35 KT RANGE AT TIMES DURING THE AFTERNOON AND EVENING.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN NO PRECIPITATION THROUGH THE AFTERNOON.
* MEDIUM CONFIDENCE ON TIMING TS MOVING THROUGH THIS EVENING.
* MEDIUM TO HIGH CONFIDENCE ON WIND TRENDS.
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...
TUESDAY...VFR.
WEDNESDAY...VFR. CHC MVFR CIGS W/SHRA ISO TSRA
MIDDAY/AFTN.
THURSDAY...VFR. CHC SHRA.
FRIDAY...VFR. CHC SHRA ISO TSRA.
SATURDAY...VFR. CHC SHRA.
LENNING
&&
.MARINE...
350 AM CDT
DEEPENING LOW PRESSURE MOVING OUT OF THE PLAINS WILL REACH
SOUTHERN MINNESOTA THIS EVENING AND MOVE INTO NORTHERN LAKE
MICHIGAN BY MONDAY MORNING. WARM SOUTHERLY WINDS WILL BE GUSTING
INTO THE 35 KT RANGE OVER LAND AND NEARSHORE WATERS TODAY...BUT
THE STRONG STABLE LAYER OVER THE COOL OPEN WATERS IS EXPECTED TO
HINDER ANY MIXING DOWN TO THE LAKE SURFACE. THOSE ON HIGHER
VESSELS COULD SEE AN OCCASIONAL GUST INTO THE MIDDLE 30S...BUT THE
GALE WARNING FOR THE OPEN WATERS APPEARS MUCH MORE LIKELY ON
MONDAY WHEN COLD AIR STARTS WORKING IN ON WEST AND NORTHWEST WINDS
BEHIND A COLD FRONT THAT WILL CROSS THE LAKE EARLY MONDAY. THE
NORTH HALF OF THE LAKE CLOSER TO THE LOW IS EXPECTED TO SEE
SLIGHTLY HIGHER WIND GUSTS MONDAY...BUT THESE WOULD START LATER IN
THE DAY COMPARED TO THE SOUTH HALF. LIKEWISE...GALES ALSO ARE
EXPECTED IN THE NEARSHORE WATERS MONDAY...BUT WITH TWO HEADLINES
ALREADY IN EFFECT TODAY...WILL NOT BE ISSUING A WATCH FOR THAT
AREA THIS MORNING. THE IDEA OF JUST CONTINUING TODAY`S GALE
WARNING ALL NIGHT INTO MONDAY WAS CONSIDERED...BUT THERE APPEARS
TO BE A PERIOD OF SOMEWHAT LIGHTER WINDS OVERNIGHT INTO EARLY
MONDAY.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 1 AM MONDAY.
IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 1 AM
MONDAY.
LM...GALE WATCH...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...10 AM MONDAY TO 9 PM
MONDAY.
DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ563 UNTIL 7 PM
SUNDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 PM MONDAY TO 1 AM TUESDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 7
PM MONDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
235 PM CDT SUN APR 15 2012
.MESOSCALE DISCUSSION...
235 PM CDT
THE 18Z SOUNDINGS FROM DVN AND ILX BOTH SHOW A MUCH MORE STOUT
CAPPING INVERSION PRESENT THAN HAD BEEN FORECAST BY THE VARIOUS
MODELS. DESPITE FAIRLY EXTENSIVE AND IN SOME CASES DENSE
CIRRUS...SFC TEMPS CONTINUE TO WARM WHICH IS HELPING WEAKEN THE
BOUNDARY LAYER CONVECTIVE INHIBITION SOMEWHAT...THOUGH SERIES OF
ACARS SOUNDINGS OUT OF MDW SHOW EVIDENCE OF INCREASING MID LEVEL
SUBSIDENCE...LIKELY IN THE WAKE OF THE LEAD WAVE THAT PASSED BY THIS
MORNING.
SOME MOISTENING/COOLING HAS BEEN NOTED ON WATER VAPOR IMAGERY OVER
SOUTHERN MISSOURI LIKELY IN ASSOCIATION WITH INCREASING ASCENT WITH
APPROACHING MID/UPPER LEVEL JET ROUNDING THE BASE OF THE TROUGH.
GIVEN THE CAPPING IN PLACE SUSPECT THAT MORE THE ROBUST/WIDESPREAD
CONVECTION IN OUR AREA MAY END UP WAITING UNTIL THE ARRIVAL OF THIS
FORCING LATE THIS AFTERNOON INTO THIS EVENING. FORECAST SOUNDINGS
FROM THE RUC DO SUGGEST THAT THIS WILL OCCUR...SO THE THREAT STILL
IS THERE FOR SEVERE WEATHER IS STILL THIS EVENING.
ASSUMING MORE INTENSE CONVECTION DOES INDEED GET GOING IN THE AREA
THIS EVENING...ITS LOOKING MORE LIKELY THAT IT WILL BE A VERY HIGH
SHEAR/LOW CAPE TYPE ENVIRONMENT WITH MAINLY A DAMAGING WIND THREAT.
THOUGH AS ALLUDED TO IN THE PREVIOUS MESO-AFD...THE EXTREME SHEAR
DOES CERTAINLY RAISE CONCERNS ABOUT THE TORNADO POTENTIAL DESPITE
THE EXPECTED LIMITED INSTABILITY.
IZZI
&&
.DISCUSSION...
1026 AM CDT
VERY DEEP //989MB// SFC LOW OVER CENTRAL NEBRASKA WILL CONTINUE TO
LIFT NORTHEAST TOWARD THE UPPER MISSISSIPPI VALLEY THROUGH
TONIGHT. PRESSURE GRADIENT AROUND THIS LOW HAS ALREADY RESULTED IN
WINDS GUSTING TO BETWEEN 30 AND 40 MPH THIS MORNING. WINDS SHOULD
CONTINUE TO INCREASE THIS AFTERNOON WITH SOME MIXED SUNSHINE AND
HEATING/MIXING...AND WHILE WE WILL SEE SOME DIURNAL SLACKENING OF
THE WINDS JUST OF THE DECK STILL THINK GUSTS OVER 40 MPH COULD
OCCUR THIS AFTERNOON. BY THIS EVENING SHOULD SEE WINDS JUST OFF
THE DECK RAPIDLY INCREASE TO 50-60KT 2000FT AGL AS EARLY AS 00Z
AND WITH STRONG PRESSURE FALLS/ISALOBARIC PUSH MAY SEE VERY LITTLE
DECOUPLING THIS EVENING WITH SURFACE WINDS PROBABLY INCREASING
EVEN FURTHER THIS EVENING. GIVEN THIS POTENTIAL HAVE OPTED TO
HOIST A WIND ADVISORY THROUGH 06Z FOR THE ENTIRE CWA.
WILL SHOOT TO HAVE A CONVECTIVE MESOSCALE AFD ISSUED PRIOR TO 17Z.
IZZI
//PREV DISCUSSION...
345 AM CDT
THE BULK OF THE OVERNIGHT SHOWER AND THUNDERSTORM ACTIVITY WILL BE
ON THE WANE AS WE APPROACH SUNRISE...WITH THE OVERALL ORIENTATION OF
THE REFLECTIVITY RETURNS TO SHIFT TO THE NORTHEAST AND EVENTUALLY
OUT OF THE CWA BY THE EARLY MORNING HOURS AS A SHORTWAVE SHOOTS OFF
TO MICHIGAN. HIGH RESOLUTION GUIDANCE HAD A DIFFICULT TIME DEALING
WITH SMALL SCALE FEATURES TONIGHT...AND NOTHING CAUGHT AN MCV
CHARGING EAST OUT OF KANSAS. IT WAS WITH THIS AREA THAT AN
IMPRESSIVE SQUALL WAS CHARGING THROUGH...PLOWING INTO IOWA AND
EVENTUALLY ACROSS OUR AREA. BY THE TIME IT HIT NORTH CENTRAL AND
NORTHEASTERN ILLINOIS...IT WEAKENED CONSIDERABLY AS THE ATMOSPHERE
WEST OF THE MISSISSIPPI WAS MUCH MORE PRIMED WHEN COMPARED TO
ACROSS THE CWA. HOWEVER...SPC ANALYSIS OF H8 MOISTURE TRANSPORT IS
INCREDIBLE AND WAS HELPING TO ADVECT IN HIGH PRECIPITABLE WATER
INTO THE AREA AND ALSO HELP TO PUSH SOME INSTABILITY ACROSS.
THE MAIN SURFACE LOW RESPONSIBLE FOR THE CURRENT WEATHER
SITUATION ACROSS THE PLAINS WILL LIFT NORTHEAST AND THROUGH
WISCONSIN BY THIS AFTERNOON. SOUTH OF THIS LOW IS A COLD FRONT
THAT WILL SWEEP ACROSS NORTHERN ILLINOIS AND NORTHWESTERN INDIANA
IN THE EVENING HOURS AND BRING THE NEXT CHANCES FOR SHOWERS AND
THUNDERSTORMS. THERE ARE A LOT OF LITTLE THINGS THAT WILL GO INTO
HOW THE FORECAST WILL PAN OUT TODAY AND TONIGHT. TO
BEGIN...AFTERNOON HIGHS WILL BE IN JEOPARDY DUE TO POTENTIAL CLOUD
COVER AND THE AMOUNT OF MIXING THAT WILL TAKE PLACE. NOT TO SOLD
ON THE FACT THAT AREAS WILL SEE FULL SUNSHINE THROUGH THE
DAY...OTHER THAN POCKETS OF BLUE. WITH THE OVERNIGHT
RAINFALL...GENERALLY THAT FELL NORTH OF I-80...THINK IT WILL TAKE
A LITTLE BIT OF TIME TO WARM...AND THAT AREAS TO THE SOUTH SHOULD
STILL SEE THE WARMEST OF TEMPS...AND THEY MAY BE UNDERDONE AS A
DRY SLOT MOVES THROUGH. LOW LEVEL FLOW WILL BE CONSIDERABLE INTO
THE AFTERNOON HOURS...AND AM ON THE FENCE WITH RESPECT TO A
POTENTIAL ADVISORY. EXPECT WINDS TO INCREASE INTO THIS AFTERNOON IN
THE WARM SECTOR AND COULD FORESEE GUSTS APPROACHING 40-45 MPH INTO
THE AFTERNOON. TECHNICAL CRITERIA FOR AN ADVISORY IS TO SEE
SUSTAINED WINDS OF 30 TO 39 MPH LASTING AN HOUR OR LONGER OR WINDS
OF 45 TO 57 MPH FOR ANY DURATION. WHILE FORECAST SOUNDINGS
INDICATE THAT THE AREA SHOULD BE MIXING UP TO H9 TO H85...AND SHOW
THE TOP OF THE MIXED CHANNEL HITTING MID TO UPPER 40 TO 50 KT
RANGE...STILL HAVING A HARD TIME SEEING COMPLETELY EFFICIENT
MIXING HAPPENING UNDER THE MOIST WARM ADVECTION REGIME. WILL HIT
WORDING AT THE UPPER NON ADVISORY THRESHOLD...AND DETAIL A BIT IN
THE HWO AS WELL.
EARLY EVENING HOURS THEN WILL BE THE MAIN EVENT FOR ACTIVITY ACROSS
THE AREA AS A COLD FRONT WILL BRING THE NEXT CHANCE FOR STRONG TO
POSSIBLY SEVERE STORMS TO THE ENTIRE AREA. SOUNDINGS FOR THE
CHICAGO AREA LOOK...SLOPPY INTO THE AFTERNOON AND EVENING HOURS
THOUGH THERE IS AN INDICATION THAT WE WILL BE MILDLY CAPPED WITH
THE INCREDIBLE WAA ONGOING. EVENTUALLY THE AREA WILL BECOME
UNSTABLE AND GUIDANCE IS INDICATING THAT CAPE VALUES OF BETWEEN
600-1000 J/KG ACROSS OUR EAST...WITH 1000-1200 J/KG WEST WILL BE
ON HAND TO START OUT. BASICALLY UNIDIRECTIONAL SHEAR WILL BE IN
PLACE AND EARLY MORNING INDICATIONS OF 0-1 BLK SHEAR VALUES OF
30-35 KT AND 0-6 VALUES OF 45 TO 50 KT WILL INCREASE TO NEAR 60 KT
IN THE EVENING AND WILL SUPPORT SEMI DISCREET CELLULAR ACTIVITY.
DESPITE THE LOW WEAKENING INTO THE EVENING AND BEING SO FAR
DISPLACED FROM OUR AREA...STILL ANTICIPATE SOME OF THE STORMS TO
APPROACH AND BECOME SEVERE AS THE FRONT RIPS THROUGH. GENERALLY
EXPECT RAPID DEVELOPMENT OF THUNDERSTORMS ACROSS SOUTHEASTERN IA
AND NORTHWESTERN MISSOURI BY THE EARLY AFTERNOON HOURS....WITH
ACTIVITY SHIFTING EAST THROUGH THE EVENING AND IMPACTING THE
CHICAGO METRO IN OR AROUND THE AROUND THE 7PM HOUR. THE BIGGEST
THREAT FOR ANY SEVERE ACTIVITY TOMORROW WILL BE HAIL AND DAMAGING
WINDS. AT THIS POINT AN ISOLATED TORNADO THREAT DOES EXIST AT
LEAST FOR A TIME GIVEN THE LOW LEVEL WIND FIELDS AND POTENTIAL FOR
GOOD LOW LEVEL INSTABILITY...BUT THE INCREASED LIKELIHOOD WILL BE
TIED CLOSER TO THE SURFACE LOW AND WARM FRONTAL INTERSECTION MORE
IN THE VICINITY OF LA CROSS. THAT SAID...ANY POTENTIAL BOUNDARY
THAT IS KICKED OUT BY DECAYING STORMS...MAY MODIFY THE WIND FIELD
ENOUGH FOR TORNADOGENESIS TO TAKE PLACE. ANY ACTIVITY SHOULD EXIT
THE AREA BY OR DURING THE OVERNIGHT HOURS. SPC`S DAY 1 OUTLOOK HAS
SHIFTED THE MODERATE BOX A LITTLE TO THE SOUTH AS THE MAIN SURFACE
LOW IS NOT MOVING AS QUICKLY AS MODELS PROGGED IT OVER THE LAST
FEW DAYS.
BEYOND THE TS ACTIVITY INTO THE EVENING...IT WILL TAKE SOME TIME FOR
WINDS TO SHIFT TO THE WEST AND FOR THE DRYING TO COMMENCE. WITH THE
LINGERING CLOUD COVER AND LIMITED COLDER AIR ADVECTION...MOST AREAS
SHOULD STAY RELATIVELY WARM TONIGHT AND INTO SUNDAY MORNING...WITH
OVERNIGHT LOWS ONLY FALLING TO THE MID 50S GENERALLY EAST OF I
57...AND A FEW DEGREES COOLER WEST AND NORTH.
NOT MUCH TIME TO GET DETAILED IN THE EXTENDED FORECAST WITH THE
ONGOING STORMS LAST NIGHT AND ACTIVE PERIOD EXPECTED TONIGHT. THE
MAIN UPPER TROUGH WILL MOVE EAST AND RIDGING WILL GRADUALLY SLIDE
OVER...BRINGING ANOTHER COOL DOWN BY MID WEEK. GUIDANCE IS STILL
AT ODDS WITH HOW THE END OF THE WEEK WILL PAN OUT...BUT CHANCES
FOR FROST LOOK GOOD NORTH OF I-88 MONDAY NIGHT AND INTO TUESDAY AS
OVERNIGHT LOWS TUMBLE. SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* STRONG LINE OF THUNDERSTORMS MOVING THROUGH THE TERMINALS THIS
EVENING. PERIODS OF HEAVY RAIN...HAIL...FREQUENT
LIGHTNING...OCNL IFR CIGS/VIS POSSIBLE.
* STRONG SOUTH-SOUTHWEST WINDS GUSTING TO 30-35 KT THROUGH THE DAY
AND INTO THE EVENING...NOT ASSOCIATED WITH THUNDERSTORMS.
PAW
//DISCUSSION...UPDATED 18Z...
STRONG LOW PRESSURE CENTER MOVING INTO MINNESTOA BY THIS EVENING
WILL SUPPORT REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS BY THIS
EVENING. THE MOST FAVORABLE AREA FOR REDEVELOPMENT IS TO THE WEST
OF THE TERMINALS...AND THEN MOVING EAST THROUGH THE EVENING. LOW
LEVEL SOUTH-SOUTHWEST WINDS ASSOCIATED WITH THE LOW WILL GUST INTO
THE 30-35 KT RANGE AT TIMES DURING THE AFTERNOON AND EVENING.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN NO PRECIPITATION THROUGH THE AFTERNOON.
* MEDIUM CONFIDENCE ON TIMING OF RENEWED CONVECTION AND LINE OF TS
MOVING THROUGH THIS EVENING.
* MEDIUM TO HIGH CONFIDENCE ON WIND TRENDS.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...
TUESDAY...VFR.
WEDNESDAY...VFR. CHC MVFR CIGS W/SHRA ISO TSRA
MIDDAY/AFTN.
THURSDAY...VFR. CHC SHRA.
FRIDAY...VFR. CHC SHRA ISO TSRA.
SATURDAY...VFR. CHC SHRA.
LENNING
&&
.MARINE...
350 AM CDT
DEEPENING LOW PRESSURE MOVING OUT OF THE PLAINS WILL REACH
SOUTHERN MINNESOTA THIS EVENING AND MOVE INTO NORTHERN LAKE
MICHIGAN BY MONDAY MORNING. WARM SOUTHERLY WINDS WILL BE GUSTING
INTO THE 35 KT RANGE OVER LAND AND NEARSHORE WATERS TODAY...BUT
THE STRONG STABLE LAYER OVER THE COOL OPEN WATERS IS EXPECTED TO
HINDER ANY MIXING DOWN TO THE LAKE SURFACE. THOSE ON HIGHER
VESSELS COULD SEE AN OCCASIONAL GUST INTO THE MIDDLE 30S...BUT THE
GALE WARNING FOR THE OPEN WATERS APPEARS MUCH MORE LIKELY ON
MONDAY WHEN COLD AIR STARTS WORKING IN ON WEST AND NORTHWEST WINDS
BEHIND A COLD FRONT THAT WILL CROSS THE LAKE EARLY MONDAY. THE
NORTH HALF OF THE LAKE CLOSER TO THE LOW IS EXPECTED TO SEE
SLIGHTLY HIGHER WIND GUSTS MONDAY...BUT THESE WOULD START LATER IN
THE DAY COMPARED TO THE SOUTH HALF. LIKEWISE...GALES ALSO ARE
EXPECTED IN THE NEARSHORE WATERS MONDAY...BUT WITH TWO HEADLINES
ALREADY IN EFFECT TODAY...WILL NOT BE ISSUING A WATCH FOR THAT
AREA THIS MORNING. THE IDEA OF JUST CONTINUING TODAY`S GALE
WARNING ALL NIGHT INTO MONDAY WAS CONSIDERED...BUT THERE APPEARS
TO BE A PERIOD OF SOMEWHAT LIGHTER WINDS OVERNIGHT INTO EARLY
MONDAY.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 1 AM MONDAY.
IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 1 AM
MONDAY.
LM...GALE WATCH...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...10 AM MONDAY TO 9 PM
MONDAY.
DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ563 UNTIL 7 PM
SUNDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 PM MONDAY TO 1 AM TUESDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 7
PM MONDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
337 PM CDT SUN APR 15 2012
.SYNOPSIS...
12Z UA ANALYSIS HAS A NEGATIVELY TILTED EXTRATROPICAL CYCLONE OVER
THE PLAINS. 850 AND 700MB WARM AND COLD FRONTS RAN FROM THE UPPER
LOW OVER NEBRASKA INTO SOUTH DAKOTA AND MINNESOTA. THE COLD FRONTS
DROPPED SOUTH FROM THE LOW INTO THE SOUTHERN PLAINS. A LLJ OF 50-70
KNOTS RAIN FROM THE GULF COAST INTO THE GREAT LAKES HELPING TO
TRANSPORT MOISTURE NORTH FROM THE GULF.
18Z SFC ANALYSIS HAS A LOW NEAR KODX WITH A SECONDARY LOW NEAR KYKN.
THE WARM FRONT RAN NORTHEAST INTO SOUTHERN MINNESOTA AND THEN EAST
INTO CENTRAL WISCONSIN. THE COLD FRONT RAN FROM THE KYKN LOW SOUTH
THROUGH THE EASTERN PARTS OF KANSAS...OKLAHOMA...AND TEXAS. A SUBTLE
TROF RAN FROM THE KYKN LOW INTO NORTHEAST MISSOURI. A NARROW BAND OF
60 DEWPOINTS FROM WISCONSIN SOUTH THROUGH ILLINOIS AND THE LOWER
MISSISSIPPI VALLEY. OUTSIDE OF THIS BAND DEW POINTS WERE IN THE 50S.
DEW POINTS IN THE 30S AND 40S WERE ACROSS THE PLAINS.
&&
.SHORT TERM...TONIGHT AND MONDAY
BASED ON CURRENT RUC TRENDS THE BETTER RAIN CHANCES WILL BE ACROSS
THE EASTERN CWFA THIS EVENING. THE WINDOW OF OPPORTUNITY FOR ANY
SEVERE STORMS IS STARTING TO CLOSE. THE SUBSTANTIAL CAP ON THE 18Z
SOUNDING IS THE LIMITING FACTOR. IF THE CAP DOES NOT BREAK BY SUNSET
THEN THE CHANCES FOR ANY SEVERE STORMS WILL RAPIDLY DECREASE.
MOST OF THE PRECIPITATION THIS EVENING WILL BE DONE BY 10 PM EXCEPT
FOR THE FAR EASTERN PARTS OF THE CWFA. WHATEVER CONVECTION IS STILL
PRESENT IN THE CWFA AT 03Z WILL EXIT THE CWFA BY MIDNIGHT. AFTER
MIDNIGHT QUIET ALBEIT WINDY CONDITIONS WILL BE SEEN ACROSS THE AREA.
WRAP AROUND CLOUDS WILL MOVE ACROSS THE CWFA MONDAY MORNING WITH
SOME SHOWERS OVER ROUGHLY THE NORTHERN HALF OF THE CWFA. SKIES WILL
SLOWLY CLEAR DURING THE AFTERNOON HOURS. THE COMBINATION OF CLOUDS
AND PRECIPITATION DURING THE MORNING HOURS WILL HOLD TEMPERATURES TO
BELOW NORMAL.
.LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY
THE MODELS HAVE A WEAK DISTURBANCE THAT MOVES THROUGH THE AREA LATE
MONDAY NIGHT/TUESDAY MORNING. SOME MODELS INITIATE PRECIP WITH THIS
FEATURE WHILE OTHERS DO NOT. FOR NOW HAVE OPTED TO KEEP THE SCHC
POPS BUT MOISTURE AVAILABILITY FOR ANYTHING TO DEVELOP IS
QUESTIONABLE. THE FACT THERE IS A WEAK DISTURBANCE MOVING THROUGH
THE AREA INDICATES MORE CLOUDS WILL BE PRESENT WHICH WILL HAVE AN
AFFECT ON TEMPERATURES. HIGH PRESSURE OVER THE AREA WILL RESULT IN
LIGHT WINDS WHICH WILL ALLOW TEMPERATURES TO COOL. FREEZING
TEMPERATURES ARE QUESTIONABLE BUT SOME PATCHY FROST MIGHT OCCUR IN
AND IMMEDIATELY SOUTH OF THE HWY 20 CORRIDOR.
AFTER A QUIET TUESDAY AFTERNOON/EVENING THE NEXT SYSTEM APPROACHES
THE AREA FROM THE PLAINS. MODELS SHOW THIS SYSTEM TO BE MORE
VIGOROUS SO THE CHANCES FOR PRECIPITATION SHOULD BE BETTER. THUS THE
SCHC/CHC POPS AFTER MIDNIGHT LOOK REASONABLE GIVEN THE TIMING.
ON WEDNESDAY THIS SYSTEM WILL MOVE ACROSS THE AREA BRINGING ANOTHER
CHANCE OF RAIN. POPS HAVE BEEN INCREASED TO HIGH CHC OVER MOST OF
THE AREA BUT MAY NEED TO BE INCREASED FURTHER TO LIKELY IF CURRENT
TRENDS WITH THE MODELS CONTINUE.
WEDNESDAY NIGHT ON...
MODEL CONSENSUS MAINTAINS AN ACTIVE NORTHWEST FLOW WITH SEVERAL
DISTURBANCES MOVING THROUGH IT. THE INITIAL WAVE ON WEDNESDAY EXITS
THE AREA WED EVENING SO THE SCHC/CHC POPS LOOK REASONABLE. MODELS
CONTINUE TO DISAGREE ON POSITION AND TIMING BUT ANOTHER STORM SYSTEM
WILL MOVE THROUGH THE AREA IN THE THURSDAY THROUGH FRIDAY EVENING
TIME PERIOD. CONSENSUS GIVES MAINLY CHC POPS WITH THE HIGHEST POPS
CENTERED ON THURSDAY NIGHT.
CONSENSUS HAS A WEAK DISTURBANCE MOVING THROUGH THE AREA ON
SATURDAY. MOISTURE IS QUESTIONABLE RIGHT NOW SO THE SCHC POPS BY THE
CONSENSUS LOOKS REASONABLE. RIGHT NOW SUNDAY LOOKS DRY WITH HIGH
PRESSURE MOVING THROUGH THE AREA. ..08..
&&
.AVIATION... /ISSUED 1234 PM CDT SUN APR 15 2012/
VERY WINDY WEATHER WITH SCATTERED STRONG TO SEVERE THUNDERSTORMS
ARE EXPECTED AT ALL EASTERN IOWA AND ILLINOIS TAF SITES TODAY.
SOUTH WINDS WILL INCREASE TO 20 TO 30 KTS...GUSTING 35 TO 40 KTS
IN THE NEXT COUPLE HOURS...AND WILL CONTINUE THROUGH 02Z
TONIGHT...BEFORE DIMINISHING TO AROUND 15 TO 25 KTS SOUTHWEST
AFTER 08Z/16. A COLD FRONT WILL MOVE THROUGH GENERALLY AROUND
12Z/16TH...SWITCHING WINDS TO NORTHWEST SUSTAINED 15 TO 20 KTS
WITH GUSTS TO 25KTS. VARIABLE VFR TO MVFR WEATHER WILL CONTINUE
NEAR THUNDERSTORMS TODAY...AND EARLY THIS EVENING...WITH GENERALLY
VFR WEATHER OTHERWISE. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WIND ADVISORY UNTIL 10 PM CDT THIS EVENING FOR BENTON-BUCHANAN-
CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-
JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...WIND ADVISORY UNTIL 10 PM CDT THIS EVENING FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...WIND ADVISORY UNTIL 10 PM CDT THIS EVENING FOR CLARK-SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
449 PM EDT SUN APR 15 2012
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 446 PM EDT SUN APR 15 2012
SHORT TERM FCST HAS BEEN A CHALLENGE TODAY WITH IMPORTANT DETAILS TO
CAPTURE IN THE GRIDS WITH NEARLY ALL FCST ELEMENTS... INCLUDING
SIGNIFICANT NON-DIURNAL TEMPS TRENDS...GALES ON THE LAKE/POSSIBLE
ADVY WINDS INLAND...POSSIBLE SVR TSRA TONIGHT...AND MIX PCPN ISSUES
MON.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS SHORTWAVE
LIFTING NE THRU THE WRN PLAINS. SFC LOW IS OVER NE NEBRASKA WITH SFC
WARM FRONT EXTENDING NE TO NEAR KMSP THAN E TO JUST N OF KGRB. FRONT
HAS MADE LITTLE PROGRESS OVER THE LAST FEW HRS...AND SO FAR...THERE
HASN`T BEEN MUCH SHRA ACTIVITY N OF THE FRONT. STRONGER LOW-MIDLEVEL
FRONTOGENESIS IS SUPPORTING BEST SHRA DEVELOPMENT TO THE W IN NE
MN/WRN LAKE SUPERIOR. HOWEVER...WITH MODELS INDICATING MOISTURE
TRANSPORT BECOMING FOCUSED TOWARD UPPER MI OVER THE NEXT FEW HRS...
SHRA SHOULD EXPAND OVER THE FCST AREA. WITH ELEVATED CAPE ALSO
INCREASING...ISOLD/SCT TSRA SHOULD ALSO DEVELOP. SVR THREAT IS
UNCERTAIN TONIGHT DUE TO UNCERTAINTY IN PROGRESS OF WARM FRONT. IF
FRONT LINGERS TO S THIS EVENING AND ELEVATED STORMS DO DEVELOP...
EFFECTIVE SHEAR WILL SUPPORT ORGANIZED UPDRAFTS AND A HAIL
POTENTIAL...ESPECIALLY OVER THE SCNTRL. IF WARM FRONT LIFTS N THRU
CNTRL/ERN UPPER MI...THERE MAY NOT BE MUCH ACTIVITY UNTIL COLD FRONT
ARRIVES LATE TONIGHT WHEN INSTABILITY WILL BE DIMINISHING. AT THIS
POINT...ELEVATED SVR STORMS APPEAR THE MORE LIKELY SCENARIO IF
STORMS CAN ORGANIZE N OF SLOW MOVING WARM FRONT. TEMPS TONIGHT WILL
ALSO BE HIGHLY DEPENDENT ON WARM FRONT LOCATION. TEMPS MAY RISE
ACROSS THE CNTRL/E WHILE A CHILLY E WIND KEEPS READINGS OVER THE
KEWEENAW IN THE LWR 40S. FOG MAY BE DENSE AT TIMES WHERE FLOW IS
UPSLOPE OFF LAKE SUPERIOR AND LAKE MICHIGAN.
SFC LOW WILL TRACK ACROSS CNTRL UPPER MI/SE LAKE SUPERIOR LATE
TONIGHT/MON MORNING. SHARP/STRONG CAA MON WILL BRING A QUICK DROP IN
TEMPS FROM NW TO SE AFTER COLD FROPA. FCST SOUNDINGS SUGGEST AT
LEAST SOME POTENTIAL FOR A BRIEF PERIOD OF SLEET BTWN THE TRANSITION
FROM RAIN TO SNOW. LOW-LEVEL TEMPS ALSO APPEAR TO FALL ENOUGH FOR
SOME LAKE ENHANCEMENT IN THE DEFORMATION PCPN AREA SWINGING ACROSS
UPPER MI MON. RIGHT NOW...EXPECT 1 TO 2 INCHES OF SNOW MON OVER THE
W AND NCNTRL. HIGH TERRAIN OF THE FAR W MAY SEE UP TO 3 INCHES.
COULD BE A SNOW ADVY EVENT IF DEFORMATION PCPN SHIELD BECOMES WELL
ORGANIZED TO THE W TONIGHT. AS FOR WINDS...SHARP CAA WILL ENHANCE
LOW-LEVEL MIXING...AND WITH 40-45KT AVBL IN THE MIXED LAYER...ADVY
LEVEL WINDS ARE A GOOD BET NEAR LAKE SUPERIOR MON...ESPECIALLY
KEWEENAW COUNTY BEGINNING IN THE MORNING AND FROM KMQT EASTWARD IN
THE AFTN. ISALLOBARIC COMPONENT TO THE WIND ROUGHLY 90 DEGREES TO
THE GRADIENT WIND SHOULD KEEP THIS FROM BEING A HIGHER END WIND
EVENT. TEMPS WILL FALL FROM NW TO SE THRU THE DAY...THOUGH THERE
WILL BE SOME WARMING OVER THE E MON MORNING PRIOR TO COLD FROPA.
TEMPS IN THE AFTN WILL PROBABLY BE AT OR BELOW FREEZING OVER THE W
AND NCNTRL.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 446 PM EDT SUN APR 15 2012
NO SIGNIFICANT CHANGES TO UPPER PATTERN DEPICTION SHOWN BY MEDIUM
RANGE MODELS YDY WITH NEGATIVE ANAMOLIES STATIONED OVER NORTHEAST
PACIFIC OCEAN/GULF OF ALASKA AND OVR HUDSON BAY INTO NUNAVUT CANADA.
ZONAL FLOW DOMINATES CONUS MUCH OF THE WEEK AND REALLY INTO NEXT
WEEKEND AS WELL. ATTM ONLY ONE SYSTEM WILL IMPACT THE AREA IN THE
LONGER TERM...BUT THAT MAY CHANGE DEPENDING ON TRACK OF LATE WEEK
SYSTEM.
BLAST OF WINTRY WEATHER GRADUALLY DIMINISHES ON MONDAY NIGHT. PLENTY
OF 925-850MB MOISTURE...CYCLONIC SFC-H85 FLOW...AND 900 TEMPS AROUND
-10C SO PREFER TO LET SNOW SHOWERS LINGER ALONG LK SUPERIOR INTO THE
OVERNIGHT HOURS FOR AREAS FAVORED BY NW WINDS. ADDITIONAL SNOW
ACCUMS MONDAY NIGHT WILL STILL BE MINIMAL. MAIN ISSUE WILL BE GUSTY
NORTH-NORTHWEST WINDS UP TO 45 MPH ALONG LK SUPERIOR ALONG WITH THE
SNOW SHOWERS. ARRIVAL OF LOW-LEVEL RIDGE DIMINISHES SNOW SHOWERS
TOWARD MORNING OVER EASTERN CWA. SFC RIDGE AND EDGE OF THERMAL TROUGH
RESULTS IN LIGHT WINDS/COOL CONDITIONS ON TUESDAY. COOLEST READINGS
AROUND 40 DEGREES ALONG LK SUPERIOR WITH NE WINDS.
SHORTWAVE ON SOUTHERN EDGE OF TROUGH OVR GULF OF ALASKA FCST TO
SLIDE ACROSS ROCKIES INTO NORTHERN PLAINS BY TUESDAY NIGHT AND PUSH
ACROSS UPPER GREAT LAKES ON WEDNESDAY. SW WINDS AHEAD OF SFC-H85
TROUGH HELP TO BRING MUCH WARMER AIR INTO UPR LAKES IN WAKE OF EARLY
WEEK CHILL AND INCREASING MOISTURE AS WELL. JET STREAKS SLIDING
ACROSS THE NORTHERN PLAINS AND OVR ONTARIO SHOULD HELP SYSTEM STAY
FAIRLY ORGANIZED AS IT CROSSES CWA ON WEDNESDAY. MSLP FCSTS DEPICT
THIS AS WELL WITH PRESSURES STEADY OR EVEN SLOWLY FALLING FM TUESDAY
NIGHT INTO WEDNESDAY ACROSS UPPER LAKES. GIVEN OVERALL DRY PATTERN
WE ARE IN CANNOT GET TOO EXCITED ABOUT SIGNIFICANT PRECIPITATION
WITH THE SYSTEM...BUT TOTAL LIQUID COULD CHECK IN AROUND 0.25 INCH
IN SOME AREAS. PTYPE MAY BE ISSUE INITIALLY LATE TUESDAY NIGHT OVER
THE WEST AS SHALLOW COLD AIR HANGS TOUGH IN WAKE OF COLD PUSH EARLY
IN THE WEEK. LATEST MODEL RUNS INDICATE POTENTIAL FOR FROZEN PRECIP
IS NOT AS HIGH AS BEFORE AS SOUTH WINDS ADVECT WELL ABOVE FREEZING
DWPNTS INTO UPR MI BY DAYBREAK WEDNESDAY. OVERALL...MAY BE SOME SNOW
OR PERHAPS FREEZING RAIN...BUT AS IT STANDS NOW IT WOULD BE PRETTY
SHORT LIVED. SOME POTENTIAL SOME SNOW AS SYSTEM EXITS ON WEDNESDAY
NIGHT. 850MB/925MB TEMPS AS LOW AS -10C/-6C WOULD EVEN OPEN DOOR TO
BRIEF LAKE ENHANCED SNOW OVR HIGHER TERRAIN OF WEST GIVEN ENOUGH
MOISTURE REMAINS AS COLDER AIR WORKS INTO UPR LAKES REGION.
IN THE EXTENDED...FRIDAY SYSTEM THAT ECMWF HAS BEEN SHOWING OFF AND
ON THE LAST FEW DAYS WAS OFF ON THE 00Z RUN BUT IS KIND OF BACK ON
AGAIN WITH THE 12Z RUN...THOUGH BULK OF HEAVIER QPF REMAINS SOUTH OF
UPR MI. GFS IS MUCH FARTHER SOUTH. SOUTHERN TRACK DOES MAKE SOME
SENSE AS PRIMARY FRONTAL BOUNDARY IS FCST TO SETTLE INTO THE
NORTHERN PORTIONS OF THE OHIO VALLEY IN WAKE OF THE WEDNESDAY SYSTEM
AND SINCE BETTER CHANCE OF CYCLOGENESIS WOULD BE ALONG THE BETTER
SFC TEMPERATURE GRADIENT. SYSTEM IS STILL NEAR THE ALLUTIANS IN THE
PACIFIC SO THERE LIKELY WILL BE SOME JUMPING AROUND ON THE POSITION
OF THE LOW YET THIS WEEK. FOR NOW THOUGH...POPS WILL STAY ON THE LOW
SIDE FOR THIS SYSTEM WITH THE HIGHER POPS OVER THE SOUTHERN CWA
THURSDAY NIGHT AND FRIDAY. ECMWF IDEA FM 12Z/14 APRIL AND 12Z THIS
MORNING WOULD INDICATE SIGNIFICANT SNOW OVR PORTIONS OF UPR LAKES
INCLUDING UPR MI.
BEYOND FRIDAY APPEARS DRY WEATHER IS IN STORE FOR NEXT WEEKEND. WILL
NOT BE ESPECIALLY WARM THOUGH AS LARGER SCALE TROUGH RESIDES OVR
MUCH OF EASTERN CANADA AND EASTERN CONUS. MODELS SHOW ANOTHER WAVE
DIVING IN FM THE PACIFIC TROUGH BUT WITH EXPECTED AMPLITUDE OF
TROUGH THIS SYSTEM WILL PROBABLY STAY TO THE SOUTH OF UPR LAKES AS
THE LATE WEEK ONE DOES. SFC-H85 RIDGE WILL BE OVERHEAD LEADING TO
LIGHT WINDS/LK BREEZES. BEST CHANCE FOR DAYTIME TEMPS AT LEAST NEAR
NORMAL WILL BE WELL INLAND FM THE LAKES TOWARD WISCONSIN BORDER.
COULD ALSO BE CHILLY NIGHTS AS WELL...WITH TEMPS POSSIBLY IN THE
TEENS AND 20S. RELATIVE HUMIDITIES LIKELY WILL BE ON THE LOW SIDE
FOR THE WEEKEND AS WELL.
APPEARS PATTERN BEGINS TO CHANGE DAYS 8-10 OR STARTING ON 24 APRIL
AS STRONG RIDGE BUILDS FM CNTRL CONUS INTO WESTERN GREAT LAKES.
GIVEN LACK OF RAINFALL THIS MONTH AND SINCE WE ARE STILL NOT
COMPLETELY GREENED UP OVR UPR MI...THE WARMER AND DRY WEATHER WILL
PROBABLY LEAD TO INCREASING FIRE WEATHER ISSUES. PLENTY OF TIME TO
DIAGNOSE THIS THOUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 143 PM EDT SUN APR 15 2012
COMPLICATED FORECAST OVER THE NEXT 24 HOURS WITH WARM FRONT SOUTH OF
THE AREA TODAY AND THIS EVENING...AND A VERY DYNAMIC SYSTEM SET TO
MOVE DIRECTLY OVER UPPER MI TONIGHT. RAIN AND ISOLATED THUNDER WILL
MOVE INTO UPPER MICHIGAN THIS AFTERNOON INTO TONIGHT. THUNDER WILL
LIKELY BE AWAY FROM THE TERMINALS...THOUGH BEST CHANCE WILL BE AT
SAW. MOST CONCERN RIGHT NOW IS WITH CIGS DROPPING FAST AT ALL SITES.
MOISTURE IS INCREASING AND FLOW HAS BECOME MORE EASTERLY EARLY THIS
AFTERNOON...SO EXPECT CIGS TO FALL QUICKLY AT CMX. CONDITIONS MAY BE
DOWN TO NEAR AIRFIELD LANDING MINIMUMS STARTING LATE THIS AFTERNOON.
FOG ALREADY OVER LAKE MI IS REVEALING PLENTY OF MOISTURE FOR SE
UPSLOPE WINDS AT SAW TO DECREASE CIGS AND VIS LATE THIS AFTERNOON.
LLWS IS POSSIBLE LATE THIS EVENING AT SAW AS LOW-LEVEL WINDS
STRENGTHEN JUST ABOVE A SHALLOW SURFACE COOL LAYER AHEAD OF THE
FRONT. RAIN SHOULD LIGHTEN UP AND VIS/CIGS SHOULD IMPROVE TONIGHT AS
THE WARM FRONT MOVES NORTH OF THE AREA. HEADING INTO MONDAY...WINDS
WILL QUICKLY TURN TO THE NNW AT ALL SITES IN THE MORNING. EXPECT
VERY GUSTY WINDS...LIKELY OVER 30KTS. -RA CHANGING TO -SN WILL ALSO
BE LIKELY DURING THE MORNING AT IWD AND CMX AS COLD AIR FILTERS INTO
THE AREA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 446 PM EDT SUN APR 15 2012
SFC LOW TRACKING FROM NE NEBRASKA TO UPPER MI/SE LAKE SUPERIOR
TONIGHT/MON MORNING WILL BRING A NE TO N GALE EVENT TO LAKE SUPERIOR
TONIGHT AND MON. GALES HAVE BEEN A LITTLE SLOW TO DEVELOP OVER THE
FAR W THIS AFTN...BUT WINDS SHOULD QUICKLY RAMP UP OVER THE NEXT FEW
HRS AS PRES FALLS INCREASE IN MAGNITUDE TO THE SW OF THE LAKE AHEAD
OF THE APPROACHING SFC LOW. AS THE LOW SHIFTS ACROSS UPPER MI/SE
LAKE SUPERIOR AND THEN E MON...NE WINDS WILL BACK N WITH GALES
QUICKLY EXPANDING E ACROSS THE LAKE. SHARP CAA/STRONG LOW-LEVEL
INSTABILITY WILL SUPPORT FREQUENT HIGH END GALE GUSTS. WINDS WILL
DIMINISH TO UNDER 20KT FROM W TO E MON NIGHT/EARLY TUE AS HIGH PRES
RIDGE BUILDS SE TO THE UPPER LAKES. LIGHTER WINDS WILL PERSIST THRU
TUE AFTN. NEXT LOW PRES SYSTEM MOVING THRU THE UPPER LAKES WED WILL
BRING ANOTHER PERIOD OF 15-25KT WINDS WED/THU...WITH THE STRONGER
WINDS AFFECTING MAINLY THE E HALF OF THE LAKE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 5 PM MONDAY TO 2 AM EDT TUESDAY FOR LSZ251-267.
GALE WARNING FROM 11 AM MONDAY TO 2 AM EDT TUESDAY FOR LSZ266.
GALE WARNING UNTIL 2 PM EDT /1 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 8 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ242>244-263-264.
GALE WARNING FROM 11 AM TO 8 PM EDT MONDAY FOR LSZ265.
GALE WARNING FROM 2 PM MONDAY TO 2 AM EDT TUESDAY FOR LSZ249-250.
GALE WARNING FROM 2 PM TO 8 PM EDT MONDAY FOR LSZ248.
GALE WARNING FROM 5 AM TO 8 PM EDT MONDAY FOR LSZ245.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...TK
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
402 PM CDT SUN APR 15 2012
.DISCUSSION...
MAIN EMPHASIS IS IN THE SHORT TERM WITH A GOOD CHANCE FOR SEVERE
WEATHER THIS AFTERNOON AND EARLY EVENING...RAIN OVERNIGHT...AND A
BRIEF CHANGE OVER TO SNOW MONDAY MORNING BEFORE THE PRECIP MOVES
OUT.
TORNADO WATCH IS IN EFFECT THIS AFTERNOON/EVENING. VISIBLE
SATELLITE CONTINUES TO SHOW GOOD CLEARING AND DESTABILIZATION IN
THE WARM SECTOR WITH GOOD DRYING ALONG WITH 20-40M 500MB HEIGHT
FALLS SHOWING UP IN WESTERN IA. THE WARM FRONT STRETCHES FROM
SOUTHWEST MN UP THROUGH THE NORTHERN TWIN CITIES METRO AND INTO
WEST CENTRAL WI. OBSERVATIONS IN THE NORTH METRO HAVEN`T TURNED
OVER TO SOUTH YET...BUT SHOULD BE CLOSE TO DOING SO.
TORNADOES...HAIL...AND WIND IS POSSIBLE ANYWHERE IN THE WARM
SECTOR AND JUST NORTH OF THE BOUNDARY WHERE LOW LEVEL HELICITY
WILL BE ENHANCED. WE ALREADY HAVE CONVECTIVE INITIATION IN SW MN
AND IA...AND THIS POTENT WAVE WILL HAVE NO TROUBLE DRIVING STORMS
ACROSS THE AREA.
SHEAR IS VERY STRONG PER AREA VWPS AND FORECAST SOUNDINGS. 0-6KM
SHEAR IS MORE THAN SUFFICIENT FOR SUPERCELLS AND 0-1KM SHEAR OF
25-30KTS SUPPORTED BY RUC ANALYSIS AND MPX 18Z SOUNDING. THESE
SOURCES ALSO SUGGEST LITTLE CIN AND AND LOW LCL TO GO ALONG WITH
1000-2000 J/KG OF SURFACE CAPE. THESE ARE STRONG INDICATORS OF
TORNADOGENESIS AND EVEN THE POTENTIAL FOR STRONG TORNADOES GIVEN
THE STRONG SHEAR PROFILE IF SUPERCELLS CAN REMAIN DISCRETE. SUPERCELLS
WILL BE LIKELY WITH TORNADOES POSSIBLE. STORMS THAT FORM AND RIDE
ALONG THE WARM FRONT MAY PRODUCE TORNADOES AND ALSO SWATHS OF
DAMAGING WINDS. TORNADO THREAT DIMINISH GREATER THAN 30KM OR SO
NORTH OF THE WARM FRONT...WHERE STORMS SHOULD BECOME ELEVATED.
THERE WILL STILL BE A HAIL THREAT WITH THE STORMS THAT RIDE NORTH
OF THE WARM FRONT THIS EVENING. AGAIN...TORNADOES ARE POSSIBLE
RIGHT ALONG THE WARM FRONT...INCLUDING THE TWIN CITIES METRO.
LATE TONIGHT...THE COLD FRONT PASSES THROUGH AND 850MB
TEMPERATURES COLLAPSE FROM NORTHWEST TO SOUTHEAST BY MONDAY
MORNING. FORECAST PROFILES AND 1000-850MB LAYER WET BULB ARE COLD
ENOUGH TO SUPPORT SNOW EARLY MONDAY MORNING IN WESTERN AND
PORTIONS OF CENTRAL MN...EVEN INTO NORTHWEST WI. THE QUESTION IS
WHETHER THE THERMAL PROFILE GETS COLD ENOUGH BEFORE THE PRECIP
ENDS. WE THINK IT WILL...BUT ONLY ENOUGH FOR AN INCH OR AT THE
MOST A COUPLE INCHES NEAR AND NORTH OF A LINE FROM ALEXANDRIA TO
LITTLE FALLS TO RICE LAKE WI. A FEW INCHES IS POSSIBLE IN NORTHERN
MN.
IN THE EXTENDED...ZONAL FLOW ACROSS THE LOWER CONUS TRANSITIONS IN
MOST GUIDANCE TO A MORE AMPLIFIED FLOW PATTERN BY NEXT WEEKEND AS
MID-UPPER LEVEL TROUGHING JUST OFF THE WEST COAST DIGS
SOUTHWARD. RIDGING OVER THE WESTERN US AND A DOWNSTREAM TROUGH TO
THE EASTERN US. MODELS AND ENSEMBLES HAVE EMBEDDED IMPULSE
DISAGREEMENT INTO WED/THU...BUT FORECAST SPREAD AND UNCERTAINTY
INCREASE MORE FRI-SUN. WENT HIGHER POPS LATE IN THE FOR THAT NEXT
IMPULSE...WITH THUNDER CHANCES TO GO ALONG WITH THE POPS. RECENT
GFS AND PARALLEL GFS RUNS OFFER MORE AMPLIFIED MID-LATITUDE
FLOW...BUT AS THE ECMWF AND OTHER MODELS OFFER POOR RUN TO RUN
CONTINUITY WITH EMBEDDED SYSTEMS HARD TO ADD TO MUCH CONFIDENCE TO
THE EXTENDED. HPC SOLUTION REFLECTS A BLEND OF GFS/NAEFS/ECMWF
ENSEMBLE MEANS AS WELL.
&&
.AVIATION.../12Z TAF ISSUANCE/
WRFNT CURRENTLY LIES FROM NEAR RWF TO JUST S OF MSP TO S OF EAU AND
SHUD CONTINUE TO MAKE A BIT OF PROGRESS N THIS AFTN...MAINLY E PTN
OF FNT. RADAR IS SHOWING DVLPG SHWRS NEAR THE FNT WITH AIRMASS
QUICKLY BECOMING MORE UNSTABLE S OF FNT. TSTMS COULD DEVELOP VERY
RAPIDLY DURING NEXT HOUR OR SO AFFECTING MAINLY MSP AND EAU.
ELEVATED SHWRS AND TSTMS STRETCH ACRS CENTRAL MN AND WILL CONTINUE
TO AFFECT STC/AXN THRU MUCH OF AFTN. S OF WRMFNT MAINLY AT MSP/EAU
INTO RNH SHUD SEE MVFR TO PRDS OF VFR DRNG AFTN WITH STRATUS
BREAKING UP...HOWEVER IFR CONDS COULD DVLP QUICKLY IN STG TSTMS.
SFC LOW NEAR SUX WILL REACH MSP AREA ARND 00Z AND THEN TRACK INTO NW
WI. STG NLY WINDS ON BACKSIDE OF LOW WILL CREATE WINDS GUSTING 30
TO 35 KTS WITH MVFR/IFR CIGS AND -RA WHICH WILL MIX WITH AND CHG TO
-SN MAINLY AXN/STC AFT 06Z.
KMSP...MAIN CONCERN IS WITH RPDLY DVLPG TSTMS THIS AFTN WITH WRMFNT
VERY NEAR THE ARPT. THESE STORMS COULD QUICLY BECOME SEVERE. WIND
DIRECTION IS PROBLEMATIC WITH SFC BOUNDRY SO CLOSE TO ARPT. TREND
SHUD BE FOR CURRENT ELY WINDS TO BECOME MORE SOUTHERLY NEXT COUPLE
OF HOURS...BUT WILL BE VARIBILITY IN PCPN.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR BLUE EARTH-
FARIBAULT-FREEBORN-MARTIN-STEELE-WASECA-WATONWAN.
WIND ADVISORY FROM 1 AM TO 7 AM CDT MONDAY FOR BLUE EARTH-BROWN-
FARIBAULT-FREEBORN-MARTIN-NICOLLET-STEELE-WASECA-WATONWAN.
WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM CDT MONDAY FOR
CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-POPE-REDWOOD-
RENVILLE-STEVENS-SWIFT-YELLOW MEDICINE.
WI...NONE.
&&
$$
CLF/BAP
AREA FORECAST DISCUSSION
NWS JACKSON MS
408 PM CDT SUN APR 15 2012
.SHORT TERM...TODAY THROUGH TUESDAY
THE OVERALL SEVERE CONCERN REMAINS MARGINAL LATE TONIGHT THRU MONDAY
MORNING AS THE FRONT STALLS. SOME REDEVELOPMENT OF TSTORMS/SHOWERS
APPEAR POSSIBLE MONDAY AFTN AS FRONT SLOWLY OOZES SOUTH WITH SMALLER
AREA OF ACTIVITY TUESDAY AFTN AS FRONT FINALLY CLEARS THE REGION.
LATEST REGIONAL RADAR DEPICTS A STRUGGLING BROKEN LINE OF SHOWERS AND
A FEW THUNDERSTORMS ACROSS EAST TEXAS. MESO-ANALYSIS CONTINUES TO
SHOW DECENT SB/ML CAPPING ALONG WITH THE 18Z KSHV RAOB IN PRESENCE OF
ELEVATED LFCS AND ~1500 ML CAPE. HI-RES MODEL RUNS AND NUMEROUS
ITERATIONS OF THE HRRR CONTINUE TO SUGGEST A SEMI-ORGANIZED BROKEN
LINE OF THUNDERSTORMS TO APPROACH WRN ZONES BY 10-MIDNIGHT TONIGHT
AND SLOWLY PUSH TOWARDS THE I-55 CORRIDOR BY SUNRISE MONDAY. FAR WRN
AREAS WILL HAVE GREATEST RISK OF STRONG TO PERHAPS A SEVERE STORM AS
DEEP-LYR ASCENT PULLS NORTH. GREATEST RISK OF THESE STORMS WILL BE
STRAIGHT-LINE WINDS OF 40-60 MPH. EXPECT LINE TO WEAKEN AS IT
CONTINUES IT`S SLOW PROGRESSION EWD THROUGH SUNRISE.
THE SYNOPTIC FRONT IS EXPECTED TO STALL ACROSS THE NRN 2/3RDS OF
REGION MONDAY MORNING AS FORCING CONTINUES TO PULL AWAY. AN UNSTABLE
BUT WEAKLY SHEARED AIRMASS WILL REMAIN IN PLACE SOUTH OF THE FRONT
MONDAY. DEPENDING ON HOW THE CONVECTIVE OUTFLOW/COLD POOL MOVES
THROUGH (NMM/ARW SUPPORTED) OR DOES NOT (SEVERAL ITERATION`S OF THE
HRRR) WILL DETERMINE OVERALL COVERAGE OF REDEVELOPMENT OF
SHOWERS/TSTORMS MONDAY AFTN. VIA GLOBAL AND REGIONAL MODELS...ENOUGH
INSTABILITY APPEARS TO BE PRESENT THAT COULD SUPPORT A FEW STRONG
STORMS AS HIGHER PWATS SLOWLY POOL SOUTH OF THE SYNOPTIC FRONT. GIVEN
THE WEAKLY SHEARED...AND SLOW LOW-LVL FLOW SOUTH OF FRONT...SOME
LOCALIZED RAIN AMOUNTS OF SEMI-ORGANIZED PULSE TSTORMS COULD REACH
UPWARDS OF 1-3 INCHES SOUTH OF THE FRONT. OVERALL RAINFALL RATES WILL
DECREASE AS INSTABILITY WANES MON NIGHT/TUE MORNING.
REGION WILL CONTINUE TO LOCATED AHEAD OF DE-AMPLIFYING L/WV TROUGH
THAT WILL PIVOT OVER THE REGION TUESDAY MORNING. THIS FEATURE WILL
PROVIDE IMPETUS TO SLOWLY PUSH THE FRONT FARTHER SOUTH TOWARD THE 84
CORRIDOR BUT ALSO ALLOW FOR SHOWER ACTIVITY TO LINGER OVERNIGHT AND
RE-INVIGORATE AHEAD OF THE FRONT TUESDAY BEFORE IT CLEARS SOUTH OF
THE REGION BY LATE TUESDAY WITH A DRYING TREND EXPECTED WEDNESDAY.
/ALLEN/
.LONG TERM...WEDNESDAY THROUGH NEXT SUNDAY...
THE TROUGH WILL FINALLY PUSH THE FRONT SOUTHEAST AND OUT OF THE
FORECAST AREA TUESDAY NIGHT. QUASI-ZONAL FLOW ALOFT WEDNESDAY INTO
THURSDAY WILL CAUSE CONDITIONS TO WARM HEADING INTO THE END OF THE
WORK WEEK. RAIN CHANCES WILL AGAIN BE ON THE INCREASE FRIDAY INTO
FRIDAY NIGHT AS ANOTHER UPPER TROUGH DIGS SOUTHEAST INTO THE DEEP
SOUTH. THIS WILL FORCE A COLD FRONT THROUGH THE CWA FRIDAY NIGHT INTO
SATURDAY. IF MODELS ARE CORRECT...A RATHER NOTICEABLY COOLER AIRMASS
WILL FILTER INTO THE ARKLAMISS SATURDAY INTO SUNDAY.
AS FAR AS NUMBERS ARE CONCERNED...I STAYED PRETTY CLOSE TO
GUIDANCE. THE ONLY NOTABLE CHANGE WAS TO INCREASE HIGHS A BIT
FOR LOCATIONS EAST OF THE MISSISSIPPI RIVER FRIDAY AFTERNOON. WITH
THE FRONT STILL WEST OF THE RIVER...EVEN WITH CLOUD COVER INCREASING
DURING THE DAY...MUCH OF THE REGION WILL STILL HAVE A GOOD
OPPORTUNITY TO WARM ABOVE THE LOW/MID 70S SUGGESTED BY GUIDANCE. /19/
&&
.AVIATION...MAIN ISSUE TODAY WILL BE WITH STRONG GUSTY
WINDS...ESPECIALLY OVER THE W/NW HALF OF THE AREA. LOOK FOR
SUSTAINED SOUTHERLY WINDS NEAR 25 MPH WITH GUSTS UP TO 40 MPH FOR
WESTERN AND NW AREAS. MOST OF THE CENTRAL AND EASTERN AREAS WILL SEE
BREEZY CONDITIONS WITH SUSTAINED WINDS 15-20 MPH AND GUSTS TO 30
MPH. WINDS WILL DISSIPATE AROUND 00Z. LATER THIS EVE/OVERNIGHT...TIMING
A WEAKENING LINE OF SHRA/TSRA WILL BE THE FOCUS. LOOK FOR MVFR
CEILINGS TO AGAIN DEVELOP AHEAD OF THAT FEATURE. CEILINGS MAY START
LOWERING BY 02-04Z. SOME LOWER RESTRICTIONS WILL BE POSSIBLE WITH AND
JUST BEHIND THE LINE AS PRECIP OCCURS. REDEVELOPMENT OF
SHOWERS/TSTORMS WILL ALSO BE POSSIBLE MON AFTN SOUTH OF THE FRONT
WITH TS BEING TIMED IN AND OUT OF TAFS. /ALLEN/CME/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 65 80 60 76 / 38 69 62 39
MERIDIAN 65 81 61 75 / 6 61 70 59
VICKSBURG 65 81 58 78 / 76 67 48 37
HATTIESBURG 69 85 64 77 / 2 79 70 61
NATCHEZ 65 80 61 76 / 77 71 63 47
GREENVILLE 63 79 57 77 / 99 31 25 12
GREENWOOD 64 80 58 76 / 76 58 36 21
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MSZ018-019-025>027-
034>036-040>042-047.
LA...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LAZ007>009-015-016-
023>026.
AR...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ARZ074-075.
&&
$$
ALLEN/CME/19
AREA FORECAST DISCUSSION
NWS BILLINGS MT
319 PM MDT SUN APR 15 2012
.SHORT TERM...VALID FOR MON AND TUE...
THE 500-HPA FLOW WILL QUICKLY DEAMPLIFY OVER THE UNITED STATES THE
NEXT 24 HOURS...HERALDING A MORE ZONAL FLOW OF PACIFIC ORIGIN THAT
WILL CONTINUE THROUGH THE WEEK. THE 12 UTC MODELS ARE DISPLAYING A
FASTER TREND WITH THE FIRST SHORT WAVE TROUGH IN THAT REGIME WHICH
IS SET TO ARRIVE ON TUE...SO WE FOLLOWED ALONG WITH A FEW FORECAST
ADJUSTMENTS IN THAT DIRECTION TOO. THE GFS MAY BE THE LEAD ON THAT
FASTER SHORT WAVE TIMING...BUT WE NOTE THAT IT IS ON THE AMPLIFIED
SIDE OF THE GUIDANCE SPREAD TOO...SO ITS SOLUTION NEEDS TO BE USED
WITH A BIT OF CAUTION.
TONIGHT...A SHORT WAVE THAT IS A RESIDUAL PART OF THE LARGER-SCALE
TROUGH THAT IMPACTED THE WESTERN HALF OF THE NATION WILL BE MOVING
ACROSS THE AREA. AS OF 21 UTC...PRECIPITATION IS INCREASING ACROSS
SOUTH CENTRAL MT ON THE LEADING EDGE OF QG FORCING WITH THIS WAVE.
SATELLITE AND RADAR IMAGES SHOW A CONVECTIVE NATURE TO MUCH OF THE
MOISTURE...VERIFYING WELL WITH THE LAST FEW HRRR RUNS...WHICH HAVE
SHOWN AN ENHANCED AREA OF CONVECTIVE SHOWERS MOVING SOUTHEAST PAST
BILLINGS AND INTO SHERIDAN BY EARLY EVENING. A MODEST ZONE OF 500-
300 Q-VECTOR CONVERGENCE IS NOTED IN THE 12 UTC GFS AND NAM ACROSS
THOSE SAME AREAS...FURTHER SUPPORTING LIKELY POPS THIS EVENING FOR
THIS REGION. HOWEVER...IF PRECIPITATION REMAINS MORE CONVECTIVE IN
NATURE LIKE IT HAS BECOME EVEN UPSTREAM AT GREAT FALLS...THEN THIS
COULD BE A BIT OVERDONE.
IN THE FOOTHILLS...UPSLOPE FLOW IS EXPECTED TO GENERATE RELATIVELY
GREATER AMOUNTS OF QPF. THE 12 UTC NAM AND GFS BOTH SIMULATE UP TO
A HALF INCH OF LIQUID-EQUIVALENT MOISTURE IN PLACES LIKE RED LODGE
THANKS TO THE UPSLOPE-ASSISTED OMEGA FIELDS. THAT CERTAINLY FAVORS
OUR WINTER WEATHER ADVISORY FOR THOSE AREAS. HAVING SAID THAT...WE
NEED TO NOTE TWO CAVEATS TO THIS SCENARIO...1/ BOTH THE 18 UTC NAM
AND 12 UTC ECMWF HAVE ARRIVED WITH LOWER QPF...AND 2/ SNOW THAT IS
FALLING AT RED LODGE AS OF 21 UTC IS MELTING AS IT FALLS. WE COULD
END UP BEING SOMEWHAT HIGH WITH OUR SNOW FORECAST GIVEN THAT...BUT
THERE IS MORE THAN ENOUGH TO STAY THE COURSE WITH THE ADVISORY FOR
NOW. THE HRRR ALSO SUPPORTS SEVERAL INCHES OF SNOW IN THIS AREA.
MON...WARM AIR ADVECTION AND WESTERLY FLOW WILL BE IN PLACE ACROSS
THE AREA. MIXING TO 700 HPA SHOULD YIELD HIGHS WELL INTO THE 50S F
IN MOST AREAS...WITH SOME 60+ F READINGS POSSIBLE IN SOME LOCALES.
A FEW MODEL SOLUTIONS ATTEMPT TO SIMULATE LIGHT PRECIPITATION WITH
THE WARM AIR ADVECTION REGIME...BUT FORECAST SOUNDINGS SUPPORT DRY
CONDITIONS THANKS TO A DRY BOUNDARY LAYER.
BY TUE...A SHORT WAVE WILL BE MOVING ACROSS THE AREA...BUT GIVEN A
WESTERLY FLOW OF PACIFIC NATURE...WE ARE NOT SURE HOW MANY SHOWERS
WILL OCCUR IN THE LOWER ELEVATIONS. CERTAINLY THIS REGIME DELIVERS
A SOLID FETCH OF FORCING INTO THE WEST-FACING MOUNTAIN SLOPES...SO
WE HAVE GONE WITH LIKELY POPS IN THOSE AREAS. HOWEVER...WE DECIDED
TO MAINTAIN CONTINUITY WITH MAINLY 30 TO 40 PERCENT POPS FOR LOWER
ELEVATIONS AND THE PLAINS...AS FORECAST SOUNDINGS SUPPORT A RATHER
DRY BOUNDARY LAYER. WE ALLOWED CONTINUITY TO RULE HIGH TEMPERATURE
FORECASTS TUE...EVEN THOUGH IT IS SEVERAL F WARMER THAN THE MULTI-
MODEL CONSENSUS IN SOME CASES. THAT IS IN RESPECT TO THE POTENTIAL
FOR ENHANCED MIXING ATTENDANT TO THE WAVE PASSAGE...WHICH SOUNDING
PROFILES DO HINT AT.
ON TUE NIGHT...WE ARE ACTUALLY UNDERCUTTING MOST GUIDANCE SINCE IT
LOOKS LIKE WEAK SURFACE RIDGING WILL MOVE ACROSS THE AREA WITH THE
FASTER WAVE TIMING ON TUE. VERIFICATION FROM SIMILAR EVENTS IN THE
RECENT PAST FAVORED THE BIAS-CORRECTED NAM OR GFS GUIDANCE...WHICH
SUGGESTS LOWS POSSIBLY INTO THE 20S F IN SOME AREAS FOR TUE NIGHT.
OF COURSE...THAT IS PREDICATED ON SOME REDUCTION IN CLOUD COVER...
AND LIGHT WINDS. SCHULTZ
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
A PROGRESSIVE PATTERN STILL EXPECTED TO DOMINATE MUCH OF THE
EXTENDED FORECAST. PREVIOUS MODEL RUNS HAD BEEN DEPICTING
WEDNESDAY AS A DRIER DAY ACROSS THE REGION WITH SOME WEAK RIDGING
BETWEEN TWO SHORTWAVES. HOWEVER...THE LATEST GFS AND ECMWF RUNS
HAVE TRENDED TO A MORE ZONAL FLOW WITH EMBEDDED WEAK VORTICITY
MAXIMA. THIS COMBINED WITH THE MOISTURE EMBEDDED IN THE ZONAL
PACIFIC FLOW...WE EXPECT TO SEE A FEW MORE SHOWERS POSSIBLE ACROSS
THE REGION ON WEDNESDAY. THE BEST CHANCES FOR PRECIP WILL BE IN
THE MOUNTAINS AND IN THE WESTERN PORTION OF THE CWA...WHERE
OROGRAPHIC LIFT WILL BE ENOUGH TO PRODUCE PRECIPITATION...HOWEVER
SOME ISOLATED TO SCATTERED SHOWERS CANNOT BE RULED OUT ACROSS THE
PLAINS. HAVE DECIDED TO INCLUDE WORDING FOR ISOLATED THUNDER IN
THE WEST SINCE FORECAST SOUNDINGS SUGGEST 100 TO 400 J/KG OF MUCAPE
DURING MAX HEATING WEDNESDAY AFTERNOON.
THE MAIN SHORTWAVE APPROACHES THE REGION WEDNESDAY NIGHT INTO
THURSDAY...AND IS PROGGED TO BE A SPLITTING WAVE WITH TWO AREAS OF
MAX QG FORCING. GIVEN THE UNCERTAINTY IN THE EXACT TRACK DETAILS OF
THE SPLITTING WAVE...AND THE CHANCE FOR MORE WIDELY SCATTERED
SHOWERS...HAVE ELECTED TO KEEP BROAD BRUSHED POP CHANCES ACROSS
THE AREA. FORECAST SOUNDINGS AGAIN HINT AT MUCAPE VALUES OF 100 TO
400 J/KG IN THE WESTERN PORTION OF THE CWA THURSDAY AFTERNOON
DURING PEAK HEATING...THUS HAVE ELECTED TO INCLUDE MENTION OF
ISOLATED THUNDER AGAIN.
THE MODELS HAVE FINALLY COME INTO BETTER AGREEMENT ABOUT THE
PATTERN FOR THIS COMING WEEKEND. THE TREND HAS BEEN FOR A MORE
AMPLIFIED RIDGE BUILDING ACROSS THE WESTERN CONUS FRIDAY THROUGH
THE WEEKEND. EXPECT TO SEE A WARMING TREND IN TEMPERATURES AS WE
HEAD INTO THE WEEKEND...WITH DRIER CONDITIONS. HOWEVER...AS THE
RIDGE IS BUILDING IN ON FRIDAY...BOTH THE GFS AND ECMWF HINT AT A
SHORTWAVE TROUGH RIDING OVER THE TOP OF THE RIDGE WHICH COULD
BRING SOME SHOWERS ACROSS THE AREA. THEREFORE...HAVE BUMPED UP THE
POPS FOR FRIDAY TO CLIMATOLOGICAL VALUES. CHURCH
&&
.AVIATION...
UPPER DISTURBANCE DROPPING SOUTHEAST INTO SOUTH CENTRAL MONTANA
AND NORTH CENTRAL WYOMING WILL BRING INCREASING PRECIPITATION
POTENTIAL THROUGH THIS EVENING...MAINLY WEST OF A ROUNDUP TO
BROADUS LINE. MVFR OR LOWER CEILINGS CAN BE EXPECTED IN THIS AREA
THROUGH THE NIGHT...WITH LOCAL IFR CONDITIONS IN PRECIPITATION.
AREAS OF FOG DEVELOPMENT ARE POSSIBLE FROM BILLINGS WEST IN THE
EARLY MORNING HOURS WHICH COULD RESULT IN LOCAL LIFR CONDITIONS.
PRECIPITATION WILL MOVE OUT OF THE AREA BEFORE SUNRISE MONDAY.
SOUTHEAST MONTANA WILL SEE MAINLY VFR CEILINGS WITH LOCAL MVFR
CONDITIONS NEAR ISOLATED SHOWER ACTIVITY. MOUNTAIN OBSCURATION
CONTINUE FOR ALL AREA MOUNTAINS TONIGHT INTO MONDAY MORNING.
CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 030/058 039/063 034/062 043/060 036/065 040/066 043/070
61/B 14/W 22/W 33/W 22/W 21/B 11/B
LVM 026/057 036/060 034/058 038/055 032/061 036/063 040/068
71/N 24/W 24/T 43/T 33/W 32/W 21/B
HDN 030/059 036/066 031/064 038/063 036/067 038/069 039/073
51/B 14/W 22/W 33/W 32/W 21/B 11/B
MLS 030/057 037/065 029/063 038/059 038/064 040/070 041/073
31/B 14/W 22/W 34/W 32/W 21/B 11/B
4BQ 026/055 033/065 030/064 037/058 037/064 038/070 038/073
32/W 13/W 22/W 34/W 32/W 21/B 11/B
BHK 027/054 032/063 030/060 037/056 035/060 036/067 036/069
32/W 14/W 22/W 34/W 32/W 21/N 11/B
SHR 028/055 033/063 029/062 037/058 036/064 039/070 040/073
72/W 13/W 22/W 33/W 32/W 21/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM MDT MONDAY FOR
ZONES 56-66.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
212 PM EDT SUN APR 15 2012
.SYNOPSIS...
SHOWERS ARE EXPECTED THIS AFTERNOON TO EARLY EVENING AS A WARM
FRONT MOVES THROUGH THE AREA...ESPECIALLY FOR CENTRAL NEW
YORK...AND LIFTING NORTHWARD INTO TONIGHT. WITH THE PASSAGE OF THE
WARM FRONT TONIGHT...HIGHS WILL INTO THE 80S MOST LOCATIONS MONDAY
AFTERNOON. A COLD FRONT WILL BRING A SHOT AT SHOWERS AND
THUNDERSTORMS TOWARD MONDAY EVENING AND INTO THE OVERNIGHT. BEHIND
THE FRONT TEMPERATURES RETURN TO MORE SEASONABLE LEVELS FOR
MIDWEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1020 AM UPDATE...RAISED POPS TO LOW CAT FOR THE NRN 1/3 OF THE
FCST AREA AND REMOVED THUNDER THREAT. ACTIVITY WILL BCM MORE
SHOWERY IN NATURE AS IT MOVS INTO CNTRL NY BUT ENUF CVRG TO
WARRANT CAT POPS NRN ZONES. PREV BLO...
855 AM UPDATE...FOR THE MRNG UPDATE WE HAVE OPTED TO RAISE POPS TO
LOW LIKELY ACRS A GOOD PORTION OF CNTRL NY AS THE NXT WAVE APRCHS
LATER THIS MRNG AND AFTN. GIVEN THE CLDS AND XPCTD SHRA WE ALSO
TWEAKED DOWN MAXES BY A FEW DEG. PREV BLO...
4 AM UPDATE...THE FORECAST IS IN VERY GOOD SHAPE AND NOT MUCH TO
CHANGE. AN AREA OF SHOWERS NOW OVER THE EASTERN PART OF THE CWA
WILL EXIT STAGE RIGHT PRIOR TO DAYBREAK WITH MOST OF THIS MORNING
ENDING UP DRY. WE WAIT THE ARRIVAL OF A WARM FRONT NOW OVER THE
OHIO VALLEY LATER TODAY. HI RES MODELS SUCH AS THE
ARW...NMM...NAM12 AND HRRR ARE ALL IN GOOD AGREEMENT WITH SOME
SCT. SHOWERS DEVELOPING OVER THE WESTERN AND CENTRAL PART OF OUR
CWA...MAINLY NORTH OF THE NY/PA LINE...BETWEEN 15Z AND 18Z. AS THE
WARM FRONT LIFTS NORTH...MAIN SHOT AT SHOWERS WILL TRACK NORTHEAST
THROUGH THE MOHAWK VALLEY LATER TODAY. BEST SHOT AT SHOWERS IN
NORTHERN PA LOOKS TO BE BRADFORD OR SUSQUEHANNA COUNTY...WITH
AGAIN HIGHEST POPS OVER NY. LEFT IN A SHOT AT ISOLATED THUNDER
TODAY BUT WITH A CAP EARLY THIS MORNING AND PLENTY OF CLOUDS
AROUND...INSTABILITY LOOKS TO BE LACKING TOO MUCH TO BE A REAL
CONCERN FOR MORE THAN A FEW RUMBLES. TOWARD LATE IN THE
DAY...FOCUS FOR SHOWERS WILL SHIFT NORTH WITH DRIER AIR BUILDING
IN FROM THE SOUTHWEST.
TONIGHT...DRYING TREND WILL CONTINUE AS WE GET INTO THE WARM
SECTOR AND PRONOUNCED DRYING OCCURS FROM NEAR THE SURFACE UP
THROUGH THE ENTIRE COLUMN. IT DOES APPEAR A FEW SHOWERS MAY
LINGER OR HANG UP OVER ONEIDA COUNTY BUT EVEN HERE WE DRY OUT
TOWARD OR SLIGHTLY AFTER MIDNIGHT AT THE LATEST. LIKE THE PREVIOUS
FORECASTER`S IDEA OF WARMER THAN GUIDANCE AND STAYED THE COURSE.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MONDAY...BREAK OUT THE SHORTS. SEE LITTLE TO CHANGE FROM OUR
FORECAST OF 80-86 ACROSS THE CWA. STILL EXPECTING MOST OF THE DAY
TO BE DRY WITH EXCELLENT AGREEMENT BETWEEN THE MODELS...INCLUDING
THE GFS/NAM/CANADIAN ALONG WITH THE HIGHER RESOLUTION MODELS. AS
A COLD FRONT APPROACHES POPS WILL INCREASE OVER THE WESTERN FINGER
LAKES INTO THE WESTERN MOHAWK VALLEY BETWEEN 21Z AND 0Z. AS FAR AS
SEVERE WEATHER POTENTIAL GOES...THE TIMING OF THE FRONT...IF
TOTALLY CORRECT AS IT STANDS NOW...MAY BE JUST A TAD TOO LATE FOR
PEAK HEATING AND THE BEST INSTABILITY. A GOOD EXAMPLE OF THIS IS
THE NAM BUFKIT SOUNDINGS FOR KSYR/KELM/KITH WHICH SHOW CAPES
AROUND 300 J/KG TOWARD EVENING...COMPARED TO KROC WHICH HAS CAPES
IN THE 700 J/KG RANGE. I LOVE THE DEPICTION FROM SPC WITH SLIGHT
RISK MAINLY ACROSS WNY...AND JUST GETTING INTO THE EXTREME WESTERN
PART OF OUR CWA...WITH SEE TEXT ELSEWHERE. THIS MATCHES UP VERY
WELL WITH THE POP FORECAST OUTLINED ABOVE THROUGH 0Z TUESDAY. WE
WILL HAVE TO WATCH THE TIMING VERY CAREFULLY BECAUSE IF THE FRONT
IS JUST A BIT FASTER...AND WE HAVE MORE INSTABILITY TO WORK
WITH...DAMAGING WINDS ARE A REAL THREAT. 0-6 KM BULK SHEAR VALUES
ON BOTH THE GFS AND NAM ARE 50-55 KTS...AND WE HAVE DRY AIR IN
BOTH THE LOW LEVELS (INVERTED V SOUNDING) AND MID-LEVELS.
MONDAY NIGHT...AS THE FRONT MOVES EAST BEST SHOT AT SOME THUNDER
AND SHOWERS WILL BE THROUGH 03Z...WITH MOISTURE AND INSTABILITY
DIMINISHING QUICKLY AS THE NIGHT WEARS ON. WITH THAT IN MIND
HIGHEST POPS WILL BE ROUGHLY NEAR I-81 AND POINTS WEST...WITH
CHANCES FOR MEASURABLE RAIN DROPPING OFF SHARPLY THE FARTHER
SOUTH AND EAST YOU GO.
TUESDAY...COOLER TEMPS FOR SURE BEHIND THE FRONT...BUT A SLOW
COOLING TREND AT 850 MB SHOULD ALLOW FOR A DECENT TEMP GRADIENT.
850S CLOSER TO +5C WILL ALLOW FOR A RANGE OF NEAR 70 OVER PIKE
COUNTY...TO 50S ACROSS THE NORTH WITH 850S SLIDING TO BELOW ZERO.
A SHORT WAVE WILL PASS TO THE NORTH OF OUR AREA BY AFTERNOON. THIS
SYSTEM WILL BE MOISTURE STARVED BUT THE SOUNDINGS ACROSS NORTHERN
ONEIDA COUNTY SHOW JUST ENOUGH MOISTURE TO WARRANT AN ISOLATED
SHOWER UP HERE FOR THE AFTERNOON HOURS. DRIER WEATHER BUILDS IN
TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
UNCERTAINTY BY THE WEEKEND WITH AMPLIFYING PATTERN...AND LARGE
SPREAD AMONG THE GFS ENSEMBLES. GENERALLY ACCEPTED HPC
GRIDS...EXCEPT DID NOT SWING AS COLD FOR TEMPERATURES INTO
SATURDAY BECAUSE HPC HIGHS WERE AT OR BELOW THE COLDEST OF THE GFS
ENSEMBLE MEMBERS. GFS AMPLIFICATION IN THE 12Z RUN TAKES LONGER TO
SET UP COMPARED TO PRIOR RUNS...THAT IS LATER IN THE
WEEKEND...WHILE THE ECWMF TAKES EVEN LONGER...WHICH ALSO COMPELLED
ME TO PULL BACK FROM DROPPING TOO QUICKLY ON THE TEMPERATURES.
PERIOD BEGINS FAIRLY MILD AHEAD OF COLD FRONT THURSDAY...WITH THAT
FRONT PASSING THROUGH IN THE AFTERNOON OR EVENING /MODELS IN
PRETTY GOOD AGREEMENT THIS EARLY IN THE LONG TERM/. I DID NOT GO
BEYOND CHANCE POPS WITH THIS FEATURE BECAUSE OF SUGGESTION IN BOTH
ECWMF AND GFS THAT THE DEEPER MOISTURE AND UPPER LEVEL WAVE WILL
RUN OUT AHEAD OF THE SURFACE FRONT...GETTING OUT OF PHASE AND THUS
OF QUESTIONABLE ORGANIZATION FOR SHOWERS.
FRONT THEN STALLS OUT A BIT TO OUR SOUTH...WHICH WITH MOIST
SOUTHWEST FLOW ALOFT...SETS UP PROLONGED PERIOD IN MOIST
BAROCLINIC LIFT ZONE LATE FRIDAY THROUGH AT LEAST SATURDAY. POPS
WERE INCREASED TO HIGH CHANCE OR LIKELY SATURDAY/SATURDAY NIGHT.
MODELS THEN DIVERGE GREATLY AS TO WHETHER AN UPPER LOW CUTS OFF
AND PHASES WITH A NEW COASTAL LOW SUNDAY...AS PER 12Z GFS...OR
SIMPLY KICKS THE WAVE THROUGH LEAVING THE AREA DRY LIKE 00Z ECWMF.
TIME OF YEAR SUGGESTS CUT OFF SCENARIO MORE LIKELY...BUT DETAILS
AND PLACEMENT OF HOW THAT OCCURS CAN BE EXPECTED TO FLUCTUATE
GREATLY IN THE MODELS DURING COMING DAYS. DEPENDING ON HOW IT
SHAKES OUT...LOOKS LIKE POTENTIAL FOR RECEIVING THE HIGHEST
PRECIPITATION AMOUNTS OF ANY EVENT OF THE LAST COUPLE
MONTHS...ALBEIT NOT A VERY HIGH HURDLE TO CLEAR.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
WARM FRONT STRETCHES FROM LAKE ERIE...ACROSS THE WESTERN NY/PA
BORDER...THEN CROSSES SLIGHTLY INTO NORTHERN COUNTIES OF PA AS OF
18Z. ALONG AND NORTH OF THIS BOUNDARY...CLOUDS STUCK UNDER SHALLOW
FRONT AND PASSING SHOWERS...WILL CAUSE MVFR CONDITIONS INITIALLY BUT
LIFTING NORTHWARD WITH TIME /SEE TAFS FOR DETAILS/. VFR AREAWIDE
BY EARLY EVENING. WITH SOUTH TO NORTH CLEARING INTO
TONIGHT...SHALLOW YET SHARP INVERSION SETS UP TONIGHT DECOUPLING
THE SURFACE WIND...ABOVE WHICH INCREASING WSW FLOW WILL YIELD LLWS
WITHIN THE LOWEST 2 KFT AGL. ONCE MIXING GETS GOING AFTER DAWN
MONDAY...LOOK FOR INCREASINGLY GUSTY SW WINDS...BUT THUNDER
CHANCES FROM COLD FRONT APPROACHING FROM THE WEST WILL WAIT
UNTIL AFTER 18Z MONDAY.
.OUTLOOK...
MON AFTN/EVNG...BAND SHRA/TSRA ALONG COLD FRONT...MOVING WEST TO
EAST YET WEAKENING WITH TIME...INCLUDING POSSIBLE MVFR AND STRONG GUSTY
WINDS /ESPECIALLY WESTERN TERMINALS/.
MON NGT THRU THU MRNG...MAINLY VFR.
THU AFTN THRU FRI...SCT MVFR IN -SHRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...
SHORT TERM...HEDEN
LONG TERM...MDP
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS TULSA OK
1245 PM CDT SUN APR 15 2012
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
SHOWERS AND THUNDERSTORMS WILL AFFECT THE ARKANSAS TAF SITES FOR
THE FIRST COUPLE HOURS OF THE FORECAST PERIOD. MVFR TO IFR
CONDITIONS MAY OCCUR IN THE STORMS. ALL SITES WILL SEE VFR
CONDITIONS BY LATE AFTERNOON WITH SKIES CLEARING OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 339 AM CDT SUN APR 15 2012/
DISCUSSION...
LARGE H5 TROUGH IS STARTING TO PIVOT EAST. MAJOR PORTION OF THE
TROUGH EJECTS TODAY...WITH REMAINDER OF TROUGH SWEEPING EAST
MONDAY AND MONDAY NIGHT. SQUALL LINE AND PSEUDO FRONT WILL PUSH
THROUGH EASTERN OK AND NORTHWEST AR TODAY. MAIN COLD FRONT/SURFACE
TROUGH WILL BE NEAR OMA-CDS LINE BY 7 PM TONIGHT...THEN SWING QUICKLY
EAST TONIGHT. NORTHWEST WINDS AND HIGH PRESSURE WILL BUILD OVER
THE AREA ON MONDAY.
NORTHWEST FLOW ALOFT WILL BRING A SHORT WAVE TROUGH THROUGH ON
WEDNESDAY...WITH SOME CLOUDINESS...BUT EXPECT NO PRECIPITATION.
TROUGH APPEARS TO MINOR OUT AS IT MOVES SOUTHEAST...AND FLOW
BECOMES NEARLY ZONAL. BETTER CHANCE OF SHOWERS OR THUNDERSTORMS
DEVELOPS ON THURSDAY AND THURSDAY NIGHT...AS H5 TROUGH DEVELOPS IN
THE FLOW AND MOVES OVER THE CENTRAL PLAINS. THE GFS AND ECMWF
TIMING ARE A LITTLE DIFFERENT...BUT BOTH SEE THIS DEVELOPMENT.
KEPT CHANCE POPS FOR THIS EVENT. MAJOR TROUGH EVENTUALLY DEVELOPS
BY NEXT WEEKEND OVER THE SOUTHEAST STATES...PUTTING OK IN NORTHWEST
FLOW.
TIMING OF PRECIPITATION THIS MORNING AND LATER TODAY IS THE
PRIMARY ISSUE. ANTICIPATE THE LINE OF STORMS TO BE FROM ABOUT
NOWATA TO TULSA TO OKEMAH AROUND 6-7 AM. THE PRECIPITATION SHOULD
REACH NORTHWEST ARKANSAS BY MID TO LATE MORNING. EXPECT THE
EXISTING LINE TO CARRY ALL THE PRECIPITATION...AND SIGNIFICANTLY
LOWERED OR DROPPED POPS BEHIND THE LINE.
GENERALLY STAYED CLOSE TO MAV/MEX MOS GUIDANCE FOR TEMPS...WITH
MINOR ADJUSTMENT TO ECMWF IN A COUPLE OF PERIODS.
WIND GUSTS ARE BECOMING MORE ISOLATED AND LATEST RUC RELAXES
SURFACE PRESSURE GRADIENT...SO WILL DROP THE WIND ADVISORY.
STILL...THERE WILL BE FREQUENT GUSTS OVER 30 MPH UNTIL THE LINE OF
STORMS MOVES THROUGH.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...05
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
327 PM CDT SUN APR 15 2012
.DISCUSSION...
THE SFC FRONT IS SLOWLY WORKING ITS WAY INTO THE COASTAL
PLAINS...WITH SCATTERED CONVECTION CONTINUING ALONG THE FRONTAL
BOUNDARY. THE FRONT IS EXPECTED TO STALL ALONG THE COAST LATER
TONIGHT...WITH GOOD CONSENSUS AMONG THE NAM/GFS OF POST-FRONTAL
PRECIPITATION CONTINUING ACROSS OUR SOUTHERN COUNTIES.
HOWEVER...THE 18Z RUC AND 12Z HI-RES BOTH INDICATE THE PRECIP AXIS
WILL SHIFT COMPLETELY SOUTH OF OUR CWA THIS EVENING. HAVE SOMEWHAT
SPLIT THE DIFFERENCE AND KEPT TOKEN POPS ACROSS OUR SOUTHEASTERN
TIER OF COUNTIES FOR THIS EVENING.
AS THE FRONT STALLS ALONG THE COAST OVERNIGHT...THE MID-UPPER
LEVEL TROUGH AXIS WILL REMAIN NORTHWEST OF OUR AREA. THEREFORE
SOME POST-FRONTAL SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP
ACROSS THE SOUTHEASTERN HALF OF THE REGION TOMORROW AND INTO
TOMORROW NIGHT. RAIN CHANCES WILL CLEAR THE AREA ON TUESDAY AS THE
UPPER TROUGH AXIS SLIDES TO THE EAST OF THE REGION AND DRIER NW
FLOW ALOFT SETTLES INTO THE AREA. MOSTLY DRY AND SEASONABLE
CONDITIONS WILL PREVAIL THROUGH THE MIDDLE OF THE WEEK WITH
ONSHORE FLOW RETURNING LATE TUESDAY/EARLY WEDS. THE INCREASING LOW
LEVEL MOISTURE WILL RESULT IN A SLOW WARMING TREND THROUGH THE END
OF THE WEEK.
MID/LONG-RANGE MODELS CONTINUE TO HAVE FAIR CONSENSUS ON AN UPPER
TROUGH/COLD FRONT FOR OUR AREA LATE IN THE WEEK. CURRENT THINKING
IS THAT THE BEST TIME-FRAME FOR RAIN WOULD BE FRI AFTERNOON/NIGHT.
HOWEVER...THIS COULD EASILY SHIFT TO A FRI NIGHT/SAT MORNING OR
LATER SCENARIO GIVEN WE`RE TALKING ABOUT 126-PLUS HRS FROM NOW.
&&
.FIRE WEATHER...
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED
ACROSS THE SOUTHERN EDWARDS PLATEAU AND RIO GRANDE PLAINS THROUGH
THIS EVENING IN THE WAKE OF THE COLD FRONT. LOW RELATIVE HUMIDITIES
AND GUSTY NORTHWEST WINDS NEAR 15 MPH WILL CONTINUE THROUGH THE
REMAINDER OF THE AFTERNOON WITH WINDS DECREASING TO 10 TO 15 MPH
AFTER SUNSET. RH VALUES WILL BE SLOWER TO RECOVER. ELEVATED FIRE
WEATHER CONDITIONS ARE EXPECTED ACROSS WESTERN AREAS ON MONDAY
AFTERNOON MAINLY DUE TO LOW HUMIDITIES AS WINDS WILL BE AT OR
BELOW 10 MPH.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 54 81 57 82 60 / - 20 10 - -
AUSTIN BERGSTROM INTL AIRPORT 52 81 55 82 56 / - 20 10 - -
NEW BRAUNFELS MUNI AIRPORT 52 80 56 81 57 / - 20 10 - -
BURNET MUNI AIRPORT 49 78 52 80 55 / - - - 0 -
DEL RIO INTL AIRPORT 51 84 57 86 63 / - - - 0 -
GEORGETOWN MUNI AIRPORT 49 79 51 81 56 / - 10 10 - -
HONDO MUNI AIRPORT 50 81 55 84 58 / - 20 10 0 -
SAN MARCOS MUNI AIRPORT 53 80 57 81 58 / - 20 10 - -
LA GRANGE - FAYETTE REGIONAL 60 80 60 80 60 / 20 40 30 10 -
SAN ANTONIO INTL AIRPORT 54 81 58 82 60 / - 20 10 - -
STINSON MUNI AIRPORT 55 81 60 83 60 / - 20 10 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...08
SYNOPTIC/GRIDS...25