Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 03/04/12
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NWS LITTLE ROCK AR
1140 PM CST THU MAR 1 2012
.AVIATION...02/06Z TAF CYCLE
LOW CLOUDS WILL CONTNIUE TO DEVELOP AND ADVECT NORTHWARD
INTO THE AREA OVERNIGHT. VFR CEILINGS WILL EVENTUALLY LOWER
TO MVFR LEVELS...WITH OCCASIONAL IFR CEILINGS TOWARD SUNRISE. CANNOT
RULE OUT ISOLATED THUNDERSTORMS OVERNIGHT...ESPECIALLY IN THE
NORTHERN HALF OF THE STATE.
A STRONG STORM SYSTEM WILL PASS TO THE NORTH OF ARKANSAS ON FRIDAY...
AND WILL DRAG A COLD FRONT THROUGH THE STATE. THE FRONT WILL LIKELY
TRIGGER THUNDERSTORMS IN THE AFTERNOON...WITH THE BEXT CHANCES OF
PRECIPITATION ALONG AND EAST OF THE MISSISSIPPI RIVER.
SOUTHERLY WINDS THROUGH FRIDAY MORNING WILL GRADUALLY BECOME
SOUTHWEST AND THEN WEST/NORTHWEST LATER IN THE DAY. WINDS ON FRIDAY
WILL BE STRONG/GUSTY...WITH GUSTS FROM 30 TO 40 MPH. VFR CONDITIONS
WILL RETURN FRIDAY AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS
INTO THE REGION BEHIND THE FRONT.
&&
.UPDATE...
HAVE MADE SOME FAIRLY NOTABLE CHANGES TO OVERNIGHT POPS AND CLOUD
COVER. LATEST HIGH RESOLUTION WRF...AND RAPID UPDATE RUC MODEL
RUNS SHOW VERY LITTLE SHOWER ACTIVITY OVERNIGHT. AS SUCH...REMOVED
MENTION OF PRECIP THROUGH MIDNIGHT...AND LIMITED POPS TO SLIGHT
CHANCE IN THE NORTH ONLY THROUGH ROUGHLY DAYBREAK. ANY SHOWERS
WILL PROBABLY BE CONFINED TO THE NORTH WHERE LARGE SCALE ASCENT IS
A LITTLE MORE PRONOUNCED LATE TONIGHT AND EARLY FRIDAY MORNING.
ALSO ADJUSTED CLOUD COVER TO ACCOUNT FOR RECENT TRENDS.
OTHERWISE...FORECAST WAS IN GOOD SHAPE OVERALL AND DID NOT MAKE
ANY OTHER SIGNIFICANT CHANGES.
&&
.PREV DISCUSSION... /ISSUED 228 PM CST THU MAR 1 2012/
SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
MOISTURE SURGE WILL GRADUALLY LIFT NORTHWARD TONIGHT...AS A WARM
FRONT ADVANCES INTO ARKANSAS. WEAK WAVE ALOFT MOVING THROUGH LATER
TONIGHT WILL INTERACT WITH THE ADVANCING FRONT...WITH SCATTERED
SHOWERS/STORMS POSSIBLE ALONG AND NORTH OF THE BOUNDARY. ANY
STORMS SHOULD MOSTLY BE NORTH OF INTERSTATE 40. SOME STRONG STORMS
ARE POSSIBLE...MAINLY AFTER MIDNIGHT...AND THE PRIMARY THREAT WITH
ANY STRONG STORMS WOULD BE LARGE HAIL. HOWEVER...INSTABILITY IS
WEAK...SO AM THINKING STRONG STORMS WOULD BE ISOLATED AT BEST.
AFTER THE INITIAL MOISTURE SURGE...LOW PRESSURE WILL BRING A COLD
FRONT INTO THE REGION DURING THE DAY FRIDAY. SHOWERS/STORMS WILL
BE POSSIBLE AHEAD OF THE FRONT...MAINLY ACROSS THE EASTERN HALF OF
THE STATE. AGAIN...SOME STORMS COULD BE STRONG...BUT I/M THINKING
THAT THE GREATEST SEVERE THREAT WILL BE EAST OF THE FORECAST AREA.
COLD HIGH PRESSURE WILL MOVE IN BEHIND THE FRONT...WITH READINGS
10-20 DEGREES COOLER BY SATURDAY. THE HIGH WILL SHIFT EASTWARD BY
LATE SUNDAY...WITH TEMPERATURES BEGINNING TO WARM.
LONG TERM...MONDAY THROUGH THURSDAY
SFC HIGH PRESSURE JUST OFF TO THE EAST OF THE STATE WILL PROVIDE AR
DRY WX...SRLY FLOW...AND ABOVE NORMAL TEMPERATURES FROM MON THROUGH
WED. AN UPR RIDGE WILL AT THE SAME TIME MOVE SLOWLY ACROSS THE SRN
PLAINS. AS THIS UPR RIDGE CONTS TO SLOWLY MOVE EAST...A PAIR OF
SHRTWVS WILL BEGIN TO AFFECT AR...THE FIRST A NRN STREAM ONE AND THE
SECOND A SRN STREAM ONE.
THE ECMWF ALLOWS THE NRN STREAM WAVE TO PUSH A SFC COLD FRONT INTO
NRN AR THU WITH PRECIP ALONG AND AHEAD OF IT. THE GFS IS WEAKER AND
FURTHER NORTH WITH THIS SHRTWV...CAUSING THE FRONT TO STALL FURTHER
NORTH. WILL CONTINUE TO HEDGE TOWARD THE STRONGLY PERFORMING ECWMF
AND LEAVE CHC POPS IN NRN AR THU AND THU NIGHT. WILL TRIM POP CHCS
BACK TO SLIGHT OVER THE REST OF THE STATE IN THIS PD. THE SECOND...
SRN STREAM SHRTWV WILL HOLD OFF UNTIL NEXT WEEKEND...AFTER THE END
OF THE FCST PD.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 73 60 70 35 / 0 40 50 10
CAMDEN AR 82 62 79 42 / 10 20 20 20
HARRISON AR 73 60 64 32 / 0 40 50 10
HOT SPRINGS AR 80 63 75 39 / 10 20 20 10
LITTLE ROCK AR 80 63 78 40 / 10 30 30 20
MONTICELLO AR 80 65 80 44 / 10 30 50 50
MOUNT IDA AR 78 63 72 37 / 10 10 20 10
MOUNTAIN HOME AR 75 58 67 33 / 0 50 50 10
NEWPORT AR 72 59 70 37 / 0 50 50 20
PINE BLUFF AR 79 63 78 43 / 10 30 30 30
RUSSELLVILLE AR 80 57 75 34 / 0 20 30 10
SEARCY AR 75 61 73 37 / 0 40 40 20
STUTTGART AR 79 63 78 41 / 10 30 40 30
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
1003 PM CST THU MAR 1 2012
.UPDATE...
HAVE MADE SOME FAIRLY NOTABLE CHANGES TO OVERNIGHT POPS AND CLOUD
COVER. LATEST HIGH RESOLUTION WRF...AND RAPID UPDATE RUC MODEL
RUNS SHOW VERY LITTLE SHOWER ACTIVITY OVERNIGHT. AS SUCH...REMOVED
MENTION OF PRECIP THROUGH MIDNIGHT...AND LIMITED POPS TO SLIGHT
CHANCE IN THE NORTH ONLY THROUGH ROUGHLY DAYBREAK. ANY SHOWERS
WILL PROBABLY BE CONFINED TO THE NORTH WHERE LARGE SCALE ASCENT IS
A LITTLE MORE PRONOUNCED LATE TONIGHT AND EARLY FRIDAY MORNING.
ALSO ADJUSTED CLOUD COVER TO ACCOUNT FOR RECENT TRENDS.
OTHERWISE...FORECAST WAS IN GOOD SHAPE OVERALL AND DID NOT MAKE
ANY OTHER SIGNIFICANT CHANGES.
&&
.PREV DISCUSSION... /ISSUED 555 PM CST THU MAR 1 2012/
AVIATION...02/00Z TAF CYCLE
VFR CONDS WL START OF THE PD...BUT LOW LVL MOISTURE WL INCRS DURG
THE OVERNIGHT HRS WITH MVFR CIGS DVLPG ACRS THE FA. WARM FNT IS
ALSO FCST TO LIFT NWD ACRS THE AREA LATER TNGT...WITH A CHC OF
CONVECTION DVLPG...MAINLY OVR NRN AR. SFC LOW WL PASS N OF THE
AREA ON FRI WITH A CDFNT PASSING EWD ACRS AR. BEST CHCS OF
ORGANIZED CONVECTION STILL LOOK TO BE ALONG AND E OF THE MS RVR.
INCRSG SW/WLY WINDS WL BRING DRIER AIR AND IMPROVING CONDS TO AR
BY FRI AFTN. /44/
PREV DISCUSSION... /ISSUED 228 PM CST THU MAR 1 2012/
SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
MOISTURE SURGE WILL GRADUALLY LIFT NORTHWARD TONIGHT...AS A WARM
FRONT ADVANCES INTO ARKANSAS. WEAK WAVE ALOFT MOVING THROUGH LATER
TONIGHT WILL INTERACT WITH THE ADVANCING FRONT...WITH SCATTERED
SHOWERS/STORMS POSSIBLE ALONG AND NORTH OF THE BOUNDARY. ANY
STORMS SHOULD MOSTLY BE NORTH OF INTERSTATE 40. SOME STRONG STORMS
ARE POSSIBLE...MAINLY AFTER MIDNIGHT...AND THE PRIMARY THREAT WITH
ANY STRONG STORMS WOULD BE LARGE HAIL. HOWEVER...INSTABILITY IS WEAK...
SO AM THINKING STRONG STORMS WOULD BE ISOLATED AT BEST.
AFTER THE INITIAL MOISTURE SURGE...LOW PRESSURE WILL BRING A COLD
FRONT INTO THE REGION DURING THE DAY FRIDAY. SHOWERS/STORMS WILL
BE POSSIBLE AHEAD OF THE FRONT...MAINLY ACROSS THE EASTERN HALF OF
THE STATE. AGAIN...SOME STORMS COULD BE STRONG...BUT I/M THINKING
THAT THE GREATEST SEVERE THREAT WILL BE EAST OF THE FORECAST AREA.
COLD HIGH PRESSURE WILL MOVE IN BEHIND THE FRONT...WITH READINGS
10-20 DEGREES COOLER BY SATURDAY. THE HIGH WILL SHIFT EASTWARD BY
LATE SUNDAY...WITH TEMPERATURES BEGINNING TO WARM.
LONG TERM...MONDAY THROUGH THURSDAY
SFC HIGH PRESSURE JUST OFF TO THE EAST OF THE STATE WILL PROVIDE AR
DRY WX...SRLY FLOW...AND ABOVE NORMAL TEMPERATURES FROM MON THROUGH
WED. AN UPR RIDGE WILL AT THE SAME TIME MOVE SLOWLY ACROSS THE SRN
PLAINS. AS THIS UPR RIDGE CONTS TO SLOWLY MOVE EAST...A PAIR OF
SHRTWVS WILL BEGIN TO AFFECT AR...THE FIRST A NRN STREAM ONE AND THE
SECOND A SRN STREAM ONE.
THE ECMWF ALLOWS THE NRN STREAM WAVE TO PUSH A SFC COLD FRONT INTO
NRN AR THU WITH PRECIP ALONG AND AHEAD OF IT. THE GFS IS WEAKER AND
FURTHER NORTH WITH THIS SHRTWV...CAUSING THE FRONT TO STALL FURTHER
NORTH. WILL CONTINUE TO HEDGE TOWARD THE STRONGLY PERFORMING ECWMF
AND LEAVE CHC POPS IN NRN AR THU AND THU NIGHT. WILL TRIM POP CHCS
BACK TO SLIGHT OVER THE REST OF THE STATE IN THIS PD. THE SECOND...
SRN STREAM SHRTWV WILL HOLD OFF UNTIL NEXT WEEKEND...AFTER THE END
OF THE FCST PD.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 73 60 70 35 / 0 40 50 10
CAMDEN AR 82 62 79 42 / 10 20 20 20
HARRISON AR 73 60 64 32 / 0 40 50 10
HOT SPRINGS AR 80 63 75 39 / 10 20 20 10
LITTLE ROCK AR 80 63 78 40 / 10 30 30 20
MONTICELLO AR 80 65 80 44 / 10 30 50 50
MOUNT IDA AR 78 63 72 37 / 10 10 20 10
MOUNTAIN HOME AR 75 58 67 33 / 0 50 50 10
NEWPORT AR 72 59 70 37 / 0 50 50 20
PINE BLUFF AR 79 63 78 43 / 10 30 30 30
RUSSELLVILLE AR 80 57 75 34 / 0 20 30 10
SEARCY AR 75 61 73 37 / 0 40 40 20
STUTTGART AR 79 63 78 41 / 10 30 40 30
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...99
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1003 PM MST THU MAR 1 2012
CORRECTED WATCH/WARNING/ADVISORY LINE
.UPDATE...CONVECTIVE SHOWERS ARE GRADUALLY DISSIPATING...ALTHOUGH
EXPECT A LITTLE REGENERATION FROM DENVER SOUTHWARD TO MORE
NORTHERLY FLOW. MOST PLACE WILL SEE LESS THAN AN INCH OVERNIGHT.
&&
.AVIATION...A FEW SNOW SHOWERS HAVE FINALLY DEVELOPED IN THE
IMMEDIATE DENVER METRO AREA...AND SHOULD MAINLY IMPACT KAPA WITH
THE MAIN SHOT OF SNOW THROUGH 08Z. MAYBE AN INCH IN THAT AREA BUT
LITTLE IF ANY ACCUMULATION AT KDEN AND KBJC OVERNIGHT. STILL A
THREAT OF 1-2 INCHES TOMORROW IF WINDS CAN TURN SLIGHTLY INTO THE
FOOTHILLS.
&&
.PREV DISCUSSION... /ISSUED 659 PM MST THU MAR 1 2012/
UPDATE...CONVECTION IS MAKING FOR A DIFFICULT FORECAST
TONIGHT...AND SIMILAR DIFFICULTY ALL THE WAY THROUGH FRIDAY.
LATEST SURFACE ANALYSIS SHOWS A STRONG ANTICYCLONE ACROSS
NORTHEAST COLORADO. THIS HAS BROUGHT DOWNSLOPING SOUTHEAST WINDS
TO DENVER...WHILE RATHER STRONG LOW LEVEL CONVERGENCE HAS
DEVELOPED IN THE FORT COLLINS TO NORTHERN WELD COUNTY AREA WHERE
CONVECTION HAS BLOSSOMED IN THE LAST HOUR. POCKETS OF 25-35 DBZ
ECHOES LIKELY RESULTING IN POCKETS OF HEAVY SNOW WITH AT LEAST 1
INCH PER HOUR RATES. QUESTION IS HOW THIS EVOLVES OVERNIGHT...AND
LATEST MESOSCALE MODELS INCLUDING THE ARW AND NMM SHOW THIS
PUSHING SOUTHEAST IN SIMILAR FASHION TO THE NAM. MEANWHILE...RUC13
AND HRRR HAD NO CLUE WHERE SNOW IS EVEN OCCURRING AT THE PRESENT
TIME. FEEL THE LATEST 4KM WRF MIGHT HAVE THE BETTER HANDLE ON IT
CONSIDERING THE LATEST SURFACE ANALYSIS...KEEPING THE HEAVIEST
SNOW IN LARIMER AND WELD COUNTIES BEFORE WEAKENING AS IT SPREADS
SOUTHEAST TO THE DENVER METRO AREA. THERE IS A LOT OF UNCERTAINTY
WITH THIS FORECAST...BUT ANYWHERE CONVECTION IS MORE PERSISTENT
COULD REQUIRE AN ADVISORY. WE WILL HAVE TO MONITOR THROUGH THE
REST OF THE NIGHT. BAND OF SNOW OR REDEVELOPMENT OF CONVECTION IS
FAIRLY LIKELY BEHIND THE NEXT COLD FRONT DROPPING SOUTHWARD ACROSS
THE PLAINS AROUND DAYBREAK FRIDAY...SO CONVECTIVE SNOW MAY
REDEVELOP WITH EVEN SOME CAPE NOTED ON FORECAST SOUNDINGS. MIGHT
HAVE TO ISSUE AN ADVISORY FOR DENVER METRO FOR THE DAY FRIDAY IF
WINDS CAN TURN INTO THE HILLS JUST ENOUGH. PALMER DIVIDE AND
SOUTHERN FOOTHILLS ARE STILL SETTING UP THE BEST.
AVIATION...CONVECTIVE SNOW SHOWERS TO THE NORTHWEST OF THE DENVER
METRO AREA AIRPORTS WILL HAVE TO BE WATCHED. AT THE CURRENT
TIME...WE DO THINK THESE SHOWERS WILL GRADUALLY WEAKEN AS THEY
PUSH TOWARD KDEN...KBJC...AND KAPA BY 03Z-06Z...BUT IFR/LIFR
CONDITIONS WOULD BE POSSIBLE WITH A QUICK INCH OF ACCUMULATION.
REST OF FORECAST UNCHANGED WITH POTENTIAL FOR MORE WIDESPREAD SNOW
FRIDAY MORNING.
PREV DISCUSSION... /ISSUED 503 PM MST THU MAR 1 2012/
UPDATE...SNOW HAS NOT MATERIALIZED ACROSS URBAN CORRIDOR AS
PREVIOUSLY THOUGHT. AFTER THE INCREASE IN UPSLOPE EARLIER THIS
AFTERNOON...THE UPSLOPE HAS WEAKEND OR BECOME NON EXISTANT AND
ECHOES HAVE MOSTLY DISSIPATED. STILL SOME ECHOES ACROSS PALMER
DIVIDE HEADING INTO LINCOLN COUNTY. SNOW SHOWERS STILL POSSIBLE
THROUGH TONIGHT...MAINLY THIS EVENING QG ASCENT MOVES ACROSS THE
REGION. BUT THESE SHOWERS WILL MAINLY BE LIGHT ACROSS THE
PLAINS...WITH LITTLE OR NO IMPACT. BEST CHANCE FOR THESE SHOWERS
STILL LOOK TO BE ALONG THE PALMER DIVIDE AND SOUTHERN FOOTHILLS.
SO MAIN CHANGE FOR THIS UPDATE WILL BE TO DROP ADVISORY FOR ZONES
39 AND 40...DECREASE POPS AND SNOW AMOUNTS. NOW LOOKS LIKE BEST
CHANCE OF ACCUMULATING SNOW SHIFTING TOWARD THE MORNING HOURS
FRIDAY BEHIND SURFACE FRONT. HILITES FOR MOUNTAINS STILL LOOK ON
TRACK
AVIATION...SNOW CHANCES ACROSS AREA THIS EVENING HAVE DECREASED.
AS A RESULT...VFR CONDITIONS TO PREVAIL WITH A CHANCE FOR MVFR
BETWEEN 02Z AND 05Z WITH PASSING SNOW SHOWERS. NEXT WAVE STILL
EXPECTED TO AFFECT AREA IN THE 10Z TO 16Z TIME FRAME WITH A BETTER
CHANCE FOR SNOWFALL AND MVFR CONDITIONS.
PREV DISCUSSION... /ISSUED 341 PM MST THU MAR 1 2012/
SHORT TERM...MOIST NORTHWEST FLOW ALOFT CONTINUES ACROSS THE
REGION THROUGH FRIDAY. AFTER A BRIEF DECREASE IN MOUNTAIN
SNOW...WEB CAMS AS WELL AS RADAR SHOW THE SNOW HAS INCREASED
AGAIN. WATER VAPOR LOOPS SHOW SOME SORT OF SHORTWAVE MOVING INTO
WESTERN COLORADO WHICH MAY BE AIDING IN THE SNOW INCREASE. THE
MOUNTAIN WARNINGS AND ADVISORIES STILL WARRANTED THROUGH TONIGHT.
THOUGH THERE MAY BE A BIT OF A DECREASE AGAIN OVERNIGHT AS SHOWN
BY THE LATEST RUC AND HRR RUNS. AS FOR PLAINS... STILL A BIT OF A
TRICKY FORECAST THIS EVENING AS MOST MODELS NOT HANDLING THINGS
WELL IN THE SHORT TERM. AIRMASS STILL A BIT UNSTABLE AND LOCAL
ACARS SOUNDINGS HAVE SHOWN A DEEPENING UPSLOPE. EARLIER SNOWBAND
HAS HELPED TO MOISTEN THE LOWER LAYERS. RADAR SHOWING ECHOES ALONG
FOOTHILLS AND URBAN CORRIDOR AS FAR NORTH AS LARIMER COUNTY...WITH
MOST OF THE ACTIVITY OVER JEFFERSON AND DOUGLAS COUNTIES. SO MOST
AREAS IN AND NEAR URBAN CORRIDOR SHOULD SEE SNOW SOON. AS
TEMPERATURES GET COLDER THIS EVENING...SHOULD ALSO SEE SOME
ACCUMULATING SNOW. ADVISORY FOR SOUTHERN FOOTHILLS AND PORTIONS OF
URBAN CORRIDOR STILL LOOKING ON TRACK. SHOULD SEE SOME BREAK IN
THE SNOWFALL TOWARDS 06Z...BASED ON THOSE RUC AND HRR RUNS. NEXT
WAVE LOOKS TO MOVE INTO THE AREA SATURDAY MORNING WHICH SHOULD
INCREASE THE SNOWFALL ACROSS THE REGION. WARNING AND ADVISORIES
FOR THE MOUNTAINS CONTINUE THROUGH FRIDAY...LOOKS REASONABLE. AS
FOR PLAINS...BEST CHANCE FOR SNOW TO BE IN THE 10Z-16Z AS THE LIFT
COMBINES WITH NORTHERLY FLOW...WITH THE BEST AREA IN ZONES 36 AND
41. FLOW BECOMES NORTHWEST DURING THE AFTERNOON...WITH DRIER AIR
WORKING ACROSS THE AREA. SHOULD SEE A DECREASE IN SNOW BY THE
AFTERNOON. OVERALL...CURRENT SNOW AMOUNTS STILL LOOK ON TRACK.
LONG TERM...BY FRIDAY EVENING PRECIP SHOULD BE ON THE DECLINE
BOTH IN THE MTNS AND ALONG THE PALMER DIVIDE WITH SUBSIDENCE ON
THE BACK SIDE OF THE PASSING UPPER TROUGH. HOWEVER WEST-NORTHWEST
MID-LEVEL FLOW SHOULD CONTINUE TO PRODUCE AREAS OF OROGRAPHIC
SNOWFALL ROUGHLY ALONG AND WEST OF THE CONTINENTAL DIVIDE THROUGH
SATURDAY EVENING. DO NOT SEE MUCH IF ANY NEW ACCUMULATION.
OTHERWISE THIS SAME FLOW WILL DRY THINGS IN THE LOWER ATMOSPHERE
EAST OF THE MTNS ON SATURDAY. HOWEVER PASSING MID-LEVEL MOISTURE
IS EXPECTED TO PRODUCE PARTLY TO MOSTLY CLOUDY SKIES FOR MUCH OF
THE DAY. CLOUDS NOT EXPECTED TO DELAY WARMUP WITH MAX TEMPS ON
THE PLAINS 8-14F WARMER THAN READINGS ON FRIDAY.
FOR SUNDAY AND BEYOND...UPPER RIDGE BUILDING OVER THE GREAT BASIN
MIGRATES SLOWLY EASTWARD OVER THE ROCKY MTN REGION WITH HIGHEST
HEIGHTS...WARMEST TEMPS ALOFT...OVER COLORADO MONDAY/MONDAY
NIGHT. COULD SEE MAX TEMPS AS MUCH AS 10DEG F ABOVE AVERAGE FOR
THE DATE. WINDS NOT MUCH OF A CONCERN SUNDAY-TUESDAY. THEN BY
MID-WEEK...MEDIUM RANGE MODELS SHOW THIS RIDGE MOVING EAST AND
THE NEXT POTENT UPPER AIR TROUGH MOVING OVER THE GREAT BASIN.
SHOULD THIS OCCUR COULD SEE SNOW CHANCES RETURNING TO THE HIGH
COUNTRY AND THE DEVELOPMENT OF STG/GUSTY SOUTH-SOUTHWESTERLY
WINDS BOTH MTNS AND PLAINS.
AVIATION...SNOW DEVELOPING AGAIN ACROSS DENVER AREA...SHOULD
PERSIST THROUGH MUCH OF THE EVENING. MVFR CONDITIONS SHOULD
PREVAIL THROUGH 03Z WITH A CHANCE FOR IFR IN HEAVIER SNOW BANDS.
SHOULD SEE CONDITIONS IMPROVE TO VFR AFTER 03Z...THOUGH CEILINGS
AROUND 5000 FEET AGL WILL PREVAIL. NEXT WAVE TO AFFECT AREA AROUND
10Z WITH MVFR CONDITIONS REDEVELOPING AS SNOW SPREADS BACK INTO
REGION. DRIER AIR TO MOVE INTO THE AREA AFTER 16Z AS WINDS BECOME
NORTHWEST. VFR TO PREVAIL THROUGH THE AFTERNOON.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 PM MST FRIDAY FOR COZ033-034. WINTER
WEATHER ADVISORY UNTIL 5 PM MST FRIDAY FOR COZ036-041. WINTER STORM
WARNING UNTIL 5 PM MST FRIDAY FOR COZ031.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM....MEIER
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1035 PM MST THU MAR 1 2012
.UPDATE...
LINGERING SHOWERS WILL BE POSSIBLE AT KCOS AND KPUB THROUGH
08Z. PLAN TO CARRY VCSH IN KPUB TAF...AND A BRIEF TEMPO GROUP FOR
KCOS THROUGH THIS PERIOD. CIGS SHOULD MAINLY STAY IN THE MVFR
CATEGORY FOR BOTH TAF SITES THROUGH THE REMAINDER OF THE NIGHT.
NEW SUITE OF MODELS SUGGESTS NEXT ROUND WILL MOVE IN TOMORROW
MORNING AFTER 12Z FOR KCOS AND KALS...AND AFTER 13-14Z FOR KPUB.
CIGS COULD DROP LOCALLY INTO THE IFR CATEGORY WITH THE HEAVIER
CONVECTIVE SNOW SHOWERS...ESPECIALLY OVER THE MOUNTAIN AREAS WHERE
MTN OBSCURATIONS CAN BE EXPECTED IN +SHSN. ADDITIONAL SNOWFALL
ACCUMULATIONS AT TERMINALS WILL MOST LIKELY REMAIN AROUND AN INCH
OR LESS...HOWEVER IF A CONVECTIVE SNOW BAND SETS UP OVER THE
TERMINAL...A QUICK 2 INCHES OF ACCUMULATION WOULD BE POSSIBLE. EXPECT
GRADUALLY IMPROVING CONDITIONS DURING THE LATE AFTERNOON AND EARLY
EVENING...WITH SOME SPORADIC ISOLATED INSTABILITY SNOW SHOWERS
CONTINUING THROUGH THE EVENING BEFORE CLEARING OUT OVERNIGHT. -KT
&&
.PREV DISCUSSION... /ISSUED 522 PM MST THU MAR 1 2012/
UPDATE...
COLD FRONT STARTING TO PUSH INTO THE EXTREME SOUTHERN PORTIONS OF
THE SOUTHEAST PLAINS...INTO LAS ANIMAS AND BACA COUNTIES. FALLING
TEMPERATURES AND INCREASING HUMIDITIES SHOULD BRING A QUICK END
TO THE RED FLAG WARNING FOR THOSE AREAS...WITH KTAD ALREADY ABOVE
THE CRITICAL RH THRESHOLD...AND KSPD NEARING THAT. THUS HAVE UPDATED
TO ALLOW THE RED FLAG WARNING TO EXPIRE. HAVE ALSO UPDATED GRIDS
TO REFLECT CURRENT TEMPERATURES/HUMIDITIES/WINDS BEHIND THE FRONT
WHICH MOVED THROUGH FASTER THAN NAM12 HAD SUGGESTED. HRRR APPEARS
TO HAVE A GOOD HANDLE ON IT...AND LEANED HEAVILY ON IT FOR GRID
PRODUCTION. OTHERWISE...POPS SEEM IN GOOD SHAPE. WITH CONVECTIVE
NATURE OF SNOW...WOULDN`T BE SURPRISED TO SEE A QUICK INCH OR TWO OF
SNOW ACROSS SOUTHERN EL PASO AND NORTHERN PUEBLO COUNTIES OVER THE
NEXT COUPLE HOURS BEFORE SHORTWAVE PUSHES EASTWARD. -KT
PREV DISCUSSION... /ISSUED 341 PM MST THU MAR 1 2012/
SHORT TERM...
(TONIGHT AND FRIDAY)
BROAD UPPER TROUGH REMAINS ACROSS THE INTERMOUNTAIN WEST WITH AN
EMBEDDED SHORT WAVE LIFTING OUT ACROSS THE CENTRAL ROCKIES AS
SECONDARY ENERGY IS DIGGING INTO THE NORTH GREAT BASIN AT THIS TIME.
AT THE SFC...BOUNDARY ASSOCIATED WITH CENTRAL ROCKIES SHORT WAVE
CURRENTLY VISIBLE ON KPUX RADAR BANKED UP ACROSS THE LOWER EASTERN
SLOPES OF RAMPART RANGE BACK THROUGH NORTHEASTERN PUEBLO COUNTY AND
INTO CENTRAL OTERO...BENT AND PROWERS COUNTIES AT THIS TIME. GUSTY
WESTERLY WINDS CONTINUE SOUTH OF THE BOUNDARY...KEEPING RED FLAG
CONDITIONS IN PLACE ACROSS THE SOUTHERN TIER ZONES AT THIS TIME.
TONIGHT AND FRIDAY...FIRST EMBEDDED WAVE CONTINUES TO LIFT OUT INTO
THE CENTRAL HIGH PLAINS THIS EVENING ALLOWING FOR FRONTAL BOUNDARY
TO CONTINUE TO SLIDE SOUTH AND WEST ACROSS ALL OF THE EASTERN PLAINS
THROUGH THE LATE EVENING. PASSING WAVE WILL KEEP SNOW...HEAVY AT
TIMES...ACROSS THE MTS OF THE CONTINENTAL DVD THROUGH THE
EVENING...WITH A SHORT LULL IN SNOWFALL EXPECTED LATER TONIGHT.
PASSING WAVE AND FRONT WILL ALSO PROVIDE LIFT FOR LIGHT SNOWFALL
ACROSS THE REST OF THE HIGHER TERRAIN AND ACROSS THE EASTERN PLAINS
THIS EVENING WITH BEST POPS ACROSS THE HIGHER ELEVATIONS OF THE
EASTERN MTS AND ACROSS THE PALMER DVD WITH NORTHERLY UPSLOPE WINDS
BEHIND FRONT. SHOULD ALSO SEE PRECIPITATION DIMINISHING ACROSS THE
EASTERN MTS AND PLAINS LATER TONIGHT...THROUGH COULD CONTINUE TO
SEE LIGHT SNOW ACROSS EASTERN SLOPES AND IMMEDIATE ADJACENT PLAINS
WITH GENERALLY WEAK MOIST LOW LEVEL UPSLOPE FLOW.
SECONDARY WAVE CONTINUES TO DIG ACROSS THE GREAT BASIN LATE TONIGHT
WHICH IS THEN PROGGED TO CONTINUE ACROSS THE STATE THROUGH THE DAY
TOMORROW...PROVIDING ANOTHER ROUND OF SNOWFALL TO THE MTS AND
IMMEDIATE ADJACENT PLAINS...AS A SECONDARY NORTHERLY SURGE OF COLD
AIR MOVES ACROSS EASTERN COLORADO. WITH THAT SAID...HAVE UPGRADED
AND ISSUED WINTER STORM WARNINGS FOR THE HIGHER ELEVATIONS OF THE
EASTERN MTS...AND THE PALMER DVD AND HAVE KEPT CURRENT HIGHLIGHTS IN
PLACE ACROSS THE CENTRAL AND SOUTHWEST MTS. LATEST LOCAL WRF DATA
INDICATING A MORE EASTERLY SFC-H7 FLOW ACROSS THE I-25 CORRIDOR
THROUGH THE DAY TOMORROW...WHICH WOULD BRING MORE SNOWFALL THAN
CURRENTLY FORECAST TO SOUTHERN PORTIONS OF EL PASO COUNTY...NORTHERN
PUEBLO COUNTY AND FREMONT COUNTY...AS WELL AS THE SOUTHERN I-25
CORRIDOR...THOUGH WILL LET THE NEXT SHIFTS GET A LOOK AT NEWER DATA
TO DECIDE ON ANY ADDITIONAL HIGHLIGHTS. -MW
LONG TERM...
FRI NITE - THU)
.STORM MOVING OUT AT THE BEGINNING OF THIS PERIOD...AND A NEW
STORM MOVING IN AT THE END OF THIS PERIOD...QUIET IN-BETWEEN...
THE HEADLINE ABOVE PRETTY MUCH TELLS THE STORY OF THE WEATHER
BETWEEN FRIDAY NIGHT INTO NEXT THURSDAY. STORM WHICH HAS BEEN
BRINGING SNOW TO THE CONTDVD AND PROMISES TO BRING SOME NEEDED
PRECIP TO THE E MTNS...I-25 CORRIDOR REGION...WILL BE MOVING OUT OF
THE AREA FRIDAY EVENING. SNOW WILL LIKELY BE STILL GOING ACROSS THE
RATON MESA REGION EARLY FRIDAY EVENING BUT SHOULD CLEAR OUT OF THE
AREA BY MIDNIGHT.
FROM SAT THRU TUESDAY...IT WILL BE MAINLY DRY OVER THE REGION
THROUGH THE PERIOD. THE ONLY EXCEPTION WILL BE ACROSS THE C MTNS
WERE SOME SNOW SHOWERS WILL BE POSSIBLE AT THE HIGHEST ELEVATIONS.
ACROSS THE REMAINDER OF THE AREA...TEMPERATURES WILL BE WARMING UP
QUITE A BIT....WITH TEMPS ON THE PLAINS AROUND 50F SAT...AROUND 60
SUNDAY...U60S MONDAY...AND AROUND 70 TUESDAY. BY WEDNESDAY...THE
NEXT BIG PACIFIC TROUGH WILL BE MOVING INTO THE REGION AND THIS
SYSTEM ONCE AGAIN PROMISES TO BRING SNOW TO THE C MTNS AND POSSIBLY
LOWER ELEVATIONS BY MID TO LATE WEEK. THERE IS STILL SOME
UNCERTAINTY THIS FAR OUT AND ONLY SLIGHT POPS ARE MENTIONED AT THE
HIGHER ELEVATIONS DURING THE MID WEEK TIME PD...BUT IF THE MODELS
CONTINUE TO SHOW CONSISTENCY...THEN POP VALUES WILL HAVE TO BE
RAMPED UP.
WITH ANOTHER STRONG TROUGH POSSIBLE AND LAPSE RATES INCREASING WITH
THE INCREASING SUN ANGLE...WE WILL LIKELY BE DEALING WITH MORE FIRE
WX ISSUES TUES AND WEDNESDAY. /34
AVIATION...
RADAR DATA AND OBS INDICATING SFC BOUNDARY PUSHED THROUGH KPUB AND
TRAILS BACK SOUTH AND EAST FROM SOUTH OF KLHX TO NORTH OF KSPD.
FRONT WILL CONTINUE TO SLIDE SOUTH AND WEST ACROSS THE REST OF THE
PAINS THIS EVENING...WITH LOW LEVEL UPSLOPE FLOW PERSISTING
OVERNIGHT. GUSTY NORTH TO NORTHEAST WINDS 15-30KTS AT KCOS AND KPUB
WILL BE COME MORE EASTERLY AND DIMINISH AFT 06Z. MVFR CONDITIONS
WITH SCATTERED SHOWERS AT BOTH TERMINALS THROUGH 06Z WITH UPSLOPE
KEEP MVFR AND LOCAL IFR CIGS ACROSS KCOS AND KPUB THROUGH THE EARLY
MORNING WHEN A SECONDARY COLD FRONT WILL BRING GUSTY NORTHERLY WINDS
AND CHANCES OF SNOW TO BOTH TERMINALS THROUGH 18Z. KALS...WILL
CONTINUE TO SEE GUSTY WEST TO SOUTHWEST WINDS THROUGH 06Z ALONG WITH
BRIEF MVFR CONDITIONS IN PASSING SHOWERS. -MW
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 AM MST FRIDAY FOR COZ059-061-
063.
WINTER WEATHER ADVISORY UNTIL 11 PM MST FRIDAY FOR COZ072-074-
079.
WINTER STORM WARNING UNTIL 11 AM MST FRIDAY FOR COZ058-060.
WINTER STORM WARNING UNTIL 11 PM MST FRIDAY FOR COZ073-075-080.
WINTER WEATHER ADVISORY UNTIL 2 PM MST FRIDAY FOR COZ064-067.
WINTER STORM WARNING UNTIL 2 PM MST FRIDAY FOR COZ066-068.
WINTER WEATHER ADVISORY UNTIL 5 PM MST FRIDAY FOR COZ081-084.
WINTER STORM WARNING UNTIL 5 PM MST FRIDAY FOR COZ082.
&&
$$
31/88
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1130 AM EST Fri Mar 2 2012
.UPDATE (Rest of Today)...
16Z water vapor and H4 RUC analysis shows an amplified upper level
pattern in place over the CONUS with an impressive longwave trough
from the inter-mountain west eastward to the MS valley. Ahead of
this trough our region resides under a region of weakly ridged flow
from the eastern Gulf of Mexico northward along the eastern seaboard.
At the surface, forecast area sits in a region of deep southerly
flow between a ridge of high pressure over the FL peninsula and a
strong cold front approaching the Mid/lower MS valley. Extensive
area of lower stratus is trying to mix out late this morning and
will see this stratus take on a more convective/strata-cu
configuration during the next few hours. This will allow periodic
breaks of sun the rest of the day. With the breaks of sun...will see
our temps respond. Inland areas will have a chance at reaching the
lower 80s, while coastal locations remain a bit cooler with the flow
off the shelf waters. Anticipate a generally dry afternoon under the
weak ridging, however this will begin to change tonight and
especially during the day on Saturday as showers and thunderstorms
develop into our region. Much more on the rain and potential severe
weather threat later tonight/Saturday will be found in the afternoon
forecast discussion.
&&
.AVIATION...thru 18z Sat.
Ceilings have lifted generally above IFR levels this late morning.
Patches of sun will promote diurnal mixing and expect Ceilings to
continue to rise through the afternoon. Anticipate most stations
holding at high end MVFR levels through the daylight hours, with
restrictions increasing once again within a few hours of Sunset. Do
expect a fairly widespread IFR event after midnight tonight with the
potential for periods of LIFR. Shower/storm chances will also begin
to increase before sunrise...especially up toward KDHN.
&&
.MARINE...
Areas of sea fog will continue to impact the nearshore coastal
waters into the early afternoon. Otherwise, onshore winds will
steadily increase through Saturday ahead of an approaching cold
front. This front will cross the waters on Saturday with offshore
winds behind the front reaching advisory levels in Sunday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 79 68 75 47 67 / 10 20 100 90 10
Panama City 72 69 70 45 67 / 20 20 90 80 10
Dothan 81 66 69 39 67 / 10 40 100 60 0
Albany 81 67 70 41 68 / 10 30 100 70 10
Valdosta 80 66 75 48 67 / 10 20 100 90 20
Cross City 79 65 79 53 67 / 10 10 50 90 40
Apalachicola 74 69 74 50 66 / 10 20 90 90 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
MROCZKA
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
105 AM EST FRI MAR 2 2012
.SYNOPSIS...
A WEAKENING COLD FRONT STALLING NORTH AND WEST OF THE AREA
OVERNIGHT. A STRONG COLD FRONT WILL THEN MOVE THROUGH THE AREA
LATE SATURDAY AFTERNOON AND SATURDAY EVENING. HIGH PRESSURE WILL
BUILD BACK INTO THE REGION ON SUNDAY AND WILL REMAIN THE DOMINANT
WEATHER FEATURE THROUGH MUCH OF NEXT WEEK. A WEAK COASTAL TROUGH
MAY FORM OVER THE NEARBY ATLANTIC DURING THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
OVERNIGHT...ANOTHER UNSEASONABLY WARM AND HUMID SETUP FOR OUR REGION
AS A NEARLY STATIONARY FRONTAL BOUNDARY EXTENDS FROM FAR NW SOUTH
CAROLINA INTO NE NORTH CAROLINA. WITH S TO SW SURFACE FLOW THROUGH
THE LOWER LEVELS AND SURFACE DEW POINTS IN THE LOWER 60S...WE
THINK TEMPS WILL BE SLOW TO FALL OVERNIGHT...ESPECIALLY AS THE
STEADY STREAM OF MID/HIGH CLOUDS CONTINUE OVER GEORGIA AND SOUTH
CAROLINA.
REGIONAL SOUNDINGS AND RUC MESOANALYSIS SHOW THE MID LEVELS HAVE
BECOME MORE STABLE. MODELS INDICATE PWATS SURGING N OVERNIGHT
WITH GULF MOISTURE WORKING INTO THE REGION ALONG WITH IMPROVING
MID LEVEL LAPSE RATES LATE. WE HAVE TRIMMED POPS BACK TO 20
PERCENT LATE OVER THE NW TIER...IN TANDEM WITH THE BELT OF DEEPER
MOISTURE LIFTING N THROUGH THE CAROLINAS.
THE NOCTURNAL INVERSION IS EXPECTED TO TRAP ABUNDANT LOW LEVEL
MOISTURE LATE TONIGHT...ESPECIALLY IN AREAS WHERE DECENT RAINFALL
OCCURRED. WHILE WE CONTINUE TO INCLUDE PATCHY FOG...WE HAVE BACKED
OFF ITS DEVELOPMENT UNTIL AFTER 3 OR 4 AM.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
MODEL SOLUTIONS ARE IN RELATIVELY GOOD AGREEMENT THROUGH THE SHORT
TERM PERIODS THIS AFTERNOON...WITH JUST SOME MINOR DIFFERENCES NOTED
WITH RESPECT TO THE COLD FRONTAL PASSAGE LATE SATURDAY AFTERNOON AND
SATURDAY EVENING.
FRIDAY AND FRIDAY NIGHT...A WARM FRONT WILL LIFT NORTHWARD
THROUGH NORTHERN PORTIONS OF THE FORECAST AREA FRIDAY
MORNING...WITH RIDGING THEN BUILDING BACK INTO THE REGION FRIDAY
AFTERNOON AND FRIDAY NIGHT. MOISTURE TRANSPORT ON THE NOSE OF
25-30 KNOT H85 JET ALONG WITH MID-LEVEL LAPSE RATES AROUND 7 C/KM
WILL NECESSITATE SLIGHT CHANCE/LOW CHANCE POPS FOR
SHOWERS/THUNDERSTORMS ACROSS NORTHERN ZONES FRIDAY MORNING. THE
ACTIVITY ASSOCIATED WITH THE WARM FRONT SHOULD BE NORTH OF THE
SOUTH SANTEE RIVER BY NOON FRIDAY...AND WITH NO LARGE SCALE
FORCING MECHANISM IN PLACE TO PROVIDE ASCENT FRIDAY AFTERNOON AND
FRIDAY NIGHT...WILL KEEP THE FORECAST RAIN FREE. LOW LEVEL
THICKNESS VALUES SUPPORT HIGHS IN THE MID 80S...BUT WITH MORNING
CLOUD COVER AND SKIES NOT CLEARING OUT ENTIRELY DURING THE
AFTERNOON...WE DON/T EXPECT TO REACH VALUES QUITE THIS HIGH. WILL
KEEP FORECAST MAX TEMPERATURES AROUND 80 TO THE LOWER 80S AWAY
FROM THE COAST. OVERNIGHT LOWS ARE EXPECTED TO BOTTOM OUT IN THE
LOWER 60S.
SATURDAY THROUGH SUNDAY...DEEP SOUTHWESTERLY FLOW WILL BE IN
PLACE TO START THINGS OFF SATURDAY IN ADVANCE OF AN APPROACHING
COLD FRONT. THIS COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
LATE SATURDAY AFTERNOON AND SATURDAY EVENING...BUT WON/T PROGRESS
TOO FAR OFF THE COAST INITIALLY. THE COLD FRONT WILL STALL NEAR
THE GULF STREAM SATURDAY NIGHT...AWAITING THE PUSH OF A STRONG
UPPER LEVEL TROUGH EARLY SUNDAY TO KICK IT FURTHER OUT TO SEA.
HIGH PRESSURE WILL THEN BUILD BACK INTO THE AREA SUNDAY AFTERNOON.
AS FOR FORECAST DETAILS...WILL KEEP SHOWERS/ISOLATED THUNDERSTORMS
CONFINED TO WESTERN ZONES SATURDAY MORNING...WITH RAIN FREE
CONDITIONS ANTICIPATED FOR COASTAL ZONES. DEEPER MOISTURE AND BETTER
FORCING FOR ASCENT WILL OVERSPREAD THE FORECAST AREA WITH THE
APPROACH OF THE COLD FRONT SATURDAY AFTERNOON...SO WILL CARRY LIKELY
POPS FOR SHOWERS/THUNDERSTORMS ACROSS THE VAST MAJORITY OF THE AREA.
STILL QUITE A BIT OF UNCERTAINTY WITH RESPECT TO THE POTENTIAL FOR
SEVERE WEATHER...AS IT WILL BE HIGHLY DEPENDENT ON THE AMOUNT OF
SURFACE BASED INSTABILITY WHICH MANAGES TO OCCUR. MODEL SOLUTIONS
SHOW QUITE A BIT OF MID/HIGH CLOUD COVER WILL BE IN PLACE THROUGH
THE DAY SATURDAY...AND THIS WOULD GREATLY LIMIT THE AMOUNT OF
DESTABILIZATION THAT COULD OCCUR. THE NAM12 SHOWS SURFACE BASED CAPE
VALUES INCREASING TO AROUND 500 J/KG WITH LIFTED INDICES LOWERING TO
BETWEEN -2 AND -3. ALTHOUGH THE INSTABILITY APPEARS THAT IT WILL BE
FAIRLY LIMITED...THE STRONGLY SHEARED ENVIRONMENT AND STRONG WIND
FIELDS ALOFT DO SUGGEST THERE WILL BE SOME POTENTIAL FOR SEVERE
WEATHER. THAT SAID...THE BEST DYNAMIC FORCING FOR ASCENT APPEARS
THAT IT WILL REMAIN DISPLACED WELL TO THE WEST OF THE COLD
FRONT...LIMITING THE POTENTIAL FOR A WELL ORGANIZED SEVERE WEATHER
EVENT...SO WILL HOLD OFF ON MENTIONING SEVERE WEATHER IN THE
HAZARDOUS WEATHER OUTLOOK AT THIS TIME.
THE COLD FRONT WILL STALL JUST OFFSHORE SATURDAY EVENING...KEEPING
DEEP MOISTURE IN PLACE ACROSS THE FORECAST AREA WHILE STRONGER UPPER
LEVEL FORCING FOR ASCENT OVERSPREADS THE REGION IN ADVANCE OF THE
APPROACHING UPPER LEVEL TROUGH. AS A RESULT...WILL CONTINUE TO KEEP
POPS IN THE LIKELY RANGE ALL LOCALES SATURDAY NIGHT. SHOWERS AND
THUNDERSTORMS SHOULD BE ONGOING SATURDAY EVENING ACROSS MUCH OF THE
FORECAST AREA...WITH THE PROBABILITY FOR THUNDER THEN STEADILY
DIMINISHING THROUGH THE NIGHT AS PRECIPITATION TRANSFORMS FROM MORE
OF A SHOWERY NATURE TO A GENERAL LIGHT TO MODERATE RAIN. THE RAIN IS
EXPECTED TO QUICKLY CLEAR THE AREA FROM WEST TO EAST SUNDAY MORNING
AS THE STRONG UPPER LEVEL TROUGH SHIFTS THROUGH THE REGION AND KICKS
THE STALLED OUT COLD FRONT AND ASSOCIATED BAND OF DEEPER MOISTURE
FURTHER OFFSHORE AND INTO THE ATLANTIC.
TEMPERATURES ARE EXPECTED TO TOP OUT IN THE MID TO UPPER 70S ON
SATURDAY...WITH LOWS SATURDAY NIGHT IN THE MID TO UPPER 40S. MUCH
COOLER CONDITIONS ARE EXPECTED ON SUNDAY...WITH HIGHS IN THE LOWER
60S MOST LOCALES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A SECONDARY COLD FRONT WILL MOVE THROUGH ON MONDAY...BUT WITH THE
DRY WEST AND NW FLOW ALOFT IT/LL COME THROUGH DRY AND GENERALLY FREE
OF EVEN ANY CLOUD COVER. HIGH PRESSURE THEN BUILDS FROM THE OH/TN
VALLEYS IN WAKE OF THIS FRONT...AND SHIFTS TOWARD THE MID ATLANTIC
COAST TUESDAY. THE HIGH WILL THEN PROGRESS INTO THE ATLANTIC FOR
WEDNESDAY AND THURSDAY...AND AS IT DOES SO WE EXPECT A COASTAL TROUGH
TO DEVELOP OVER THE NEARBY ATLANTIC WATERS. THE RETURN OF MOISTURE
WILL BE SLOW...BUT GRADUAL WITH THE SYNOPTIC FLOW BECOMING NE AND
EAST DURING THE MIDDLE OF THE WEEK. EVENTUALLY THIS MAY ALLOW FOR A
FEW SHOWERS TO CREEP ONSHORE...BUT NOTHING MORE THAN ISOLATED
ACTIVITY IS EXPECTED AT THIS TIME. TEMPS LOOK TO BE NEAR OR EVEN
BELOW NORMAL THROUGH WEDNESDAY...WITH SOME MODERATION THURSDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
EVENTUALLY MVFR CONDITIONS WILL DEVELOP AT BOTH TERMINALS BEFORE
DAYBREAK...THE RESULT OF YESTERDAY RAINFALL AND/OR POOLING OF
MOISTURE BENEATH THE NOCTURNAL INVERSION. IN ADDITION WE COULD SEE
A FEW HOURS OF IFR WEATHER FROM 11-15Z...BUT PROBABILITIES ARE NOT
ENOUGH TO INCLUDE WITH THE LATEST TAFS. VFR WEATHER THEN RETURNS
FOR THE BULK OF THE DAY FRIDAY INTO THE FIRST PART OF FRIDAY NIGHT.
SOUNDINGS AND THE VAD WIND PROFILE ARE SHOWING WINDS NEAR 30 KT AT
2K FEET...WHICH CONTINUES THE FIRST FEW HOURS OF THE 06Z TAF
CYCLE. SOUTH AND SW SURFACE WINDS WILL BECOME GUSTY FRIDAY
AFTERNOON...AS MIXING HEIGHTS TAP INTO 20-25 KT WINDS WITHIN THE
BOUNDARY LAYER. WIND SHEAR IS LIKELY AGAIN FRIDAY NIGHT AND WILL
BE INCLUDED IN LATER TAF ISSUANCES.
EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CIGS/VSBYS APPEAR TO BE A
FAIRLY GOOD PROBABILITY SATURDAY THROUGH EARLY SUNDAY AS A SLOW
MOVING COLD FRONT MOVES THROUGH WITH WIDESPREAD SHOWERS AND
THUNDERSTORMS. VFR CONDITIONS WILL RETURN SUNDAY AFTERNOON THROUGH
TUESDAY AS HIGH PRESSURE BUILDS BACK INTO THE AREA. WIND SHEAR
AND/OR GUSTY SURFACE WINDS WILL IMPACT THE TERMINALS FRIDAY NIGHT
THROUGH SATURDAY.
&&
.MARINE...
SW FLOW OVERNIGHT...IN THE 10-15 KT RANGE THIS EVENING...DIMINISHING
SEAWARD AS THE LOW LEVEL JET SLOWLY WEAKENS. SEAS 2 TO 4 FT FOR
THE MOST PART...LOWEST AROUND GRAYS REEF AND HIGHEST FROM BUOY SIX
OFF THE CHARLESTON COUNTY OUT TO BUOY 41004 AND PERHAPS WELL OFF
THE GEORGIA COAST BEYOND 40 NM OFFSHORE.
FRIDAY THROUGH TUESDAY...A WEAK WARM FRONT WILL LIFT NORTHWARD
THROUGH THE SOUTH CAROLINA WATERS FRIDAY MORNING. A STRONG COLD
FRONT WILL APPROACH FROM THE WEST ON SATURDAY AND MOVE THROUGH THE
MARINE AREA SATURDAY NIGHT. HIGH PRESSURE WILL THEN BUILD BACK
INTO THE REGION ON SUNDAY AND WILL REMAIN THE DOMINANT WEATHER
FEATURE THROUGH EARLY NEXT WEEK.
INCREASING SOUTH-SOUTHWEST FLOW IN ADVANCE OF THE COLD FRONT COULD
LEAD TO SMALL CRAFT HEADLINES ACROSS PORTIONS OF THE WATERS FRIDAY
NIGHT THROUGH SUNDAY FOR WINDS/SEAS OR A COMBINATION OF THE TWO.
CONDITIONS ARE EXPECTED TO REMAIN BELOW HEADLINE THRESHOLDS SUNDAY
NIGHT THROUGH MONDAY. SMALL CRAFT CONDITIONS MAY AFFECT PORTIONS OF
THE WATERS AGAIN MONDAY NIGHT AND TUESDAY AS THE GRADIENT PINCHES
DUE TO COASTAL TROUGH DEVELOPMENT OFF THE SOUTHEAST COAST.
&&
.CLIMATE...
RECORD MAX TEMPS FOR MARCH 2...
KCHS...85 SET IN 1997 AND PREVIOUS YEARS.
KCHL...81 SET IN 1976.
KSAV...86 SET IN 1951.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1129 AM CST FRI MAR 2 2012
.DISCUSSION...
ISSUED 1035 AM CST FRI MAR 2 2012
SURFACE LOW CURRENTLY CENTERED JUST SOUTH OF LITCHFIELD. INITIAL
BANDS OF ELEVATED CONVECTION CONTINUE TO ARC NORTHEAST TO
CHAMPAIGN AND DANVILLE. STILL GETTING HAIL OF PEA TO DIME SIZE AT
TIMES. ASSOCIATED WARM FRONT HAS ARCHED NORTHEAST TO AROUND I-70
AND TEMPERATURES IN THE FAR SOUTHEAST CWA HAVE SURGED INTO THE 70
DEGREE RANGE...WITH DEWPOINTS AROUND 60.
LATEST HRRR SHOWING THE TRACK OF THE LOW SHOULD MOVE NORTHEAST TO
NEAR KANKAKEE BY AROUND 2 PM. HAVE BEEN SEEING RAPID DEVELOPMENT
OF SEVERE CONVECTION ACROSS SOUTHEAST MISSOURI AND SOUTHWEST
ILLINOIS IN THE WARM SECTOR...AND THIS WILL BE LIFTING NORTHEAST
ACROSS THE SOUTHEAST HALF OF THE CWA DURING THE MIDDAY AND EARLY
AFTERNOON HOURS. TORNADO WATCH CURRENTLY AFFECTING ABOUT THE
EASTERN HALF OF THE CWA...WITH THE TIME PERIOD THROUGH ABOUT 3 PM
MOST AT RISK OF SEVERE WEATHER. ACROSS THE NORTHWEST CWA...STILL
HAVE TRENDED TOWARD SOME SNOW DEVELOPMENT LATE IN THE AFTERNOON...
BUT THE DEFORMATION ZONE LIFTS QUICKLY NORTHEAST...AND HAVE BACKED
DOWN ON ANY ACCUMULATIONS UP TOWARD GALESBURG.
UPDATED ZONES/GRIDS SENT TO REFLECT LATEST CONVECTIVE TRENDS...AS
WELL AS ADJUSTING THE TEMPERATURES DUE TO THE SHARP CONTRAST
ASSOCIATED WITH THE TRACK OF THE LOW.
GEELHART
&&
.AVIATION...
ISSUED 1128 AM CST FRI MAR 2 2012
INITIAL CONCERN IS WITH CONVECTION POTENTIAL THIS AFTERNOON.
CURRENTLY LOOKS LIKE KCMI WILL BE MOST IMPACTED WITH HAIL AND
GUSTS OVER 35 KNOTS AT TIMES...WITH THE PERIOD THROUGH 21Z MOST AT
RISK. ELSEWHERE...STRONG LOW PRESSURE WILL CONTINUE MOVING
NORTHEAST ACROSS CENTRAL ILLINOIS...AND WINDS WILL BACK TO THE
NORTHWEST AND INCREASE TO 20-25 KNOTS WITH GUSTS OVER 30 KNOTS AT
TIMES. LARGE AREA OF STRATOCUMULUS WAS APPROACHING KSPI/KPIA AND
WILL OVERSPREAD THE TAF SITES THROUGH EARLY AFTERNOON WITH MVFR
CEILINGS. A LOOK AT FORECAST SOUNDINGS AT KPIA CONTINUE TO SHOW
POTENTIAL FOR SOME RAIN/SNOW MIX BY LATE AFTERNOON. MOST OF THE
PRECIPITATION AT THE TAF SITES WILL TAIL OFF BY 00Z. LAYER
HUMIDITY PLOTS SHOWING A PERIOD OF VFR CEILINGS FOR A FEW HOURS
LATE EVENING AND JUST PAST 06Z...BEFORE MVFR STRATOCUMULUS PUSHES
BACK SOUTHWARD OVERNIGHT. LOOKS LIKE THESE SHOULD LAST MOST OF THE
REMAINDER OF THE FORECAST PERIOD.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 320 AM CST FRI MAR 2 2012
YET ANOTHER POWERFUL STORM SYSTEM TO IMPACT IL ON THE HEALS OF A
STRONG STORM SYSTEM THAT AFFECTED THE AREA THIS PAST TUE NIGHT.
FORECAST CONCERN IS SEVERE WEATHER THREAT WITH MODERATE RISK IN SE
IL TODAY AND SLIGHT RISK AS FAR NW AS I-55. ANOTHER ISSUE IS HOW
STRONG GRADIENT WINDS GET DURING THIS AFTERNOON/EVENING AND IF A
WIND ADVISORY IS NEEDED. YET ANOTHER CONCERN IS SNOWFALL AMOUNTS
NW OF THE IL RIVER THIS AFTERNOON AND EARLY EVENING. 00Z MODELS
COMING INTO BETTER AGREEMENT OF DEEPENING LOW PRESSURE LIFTING NE
INTO THE HEART OF IL BY 18Z/NOON TODAY AND INTO NE LOWER MI BY
SAGINAW BAY BY MIDNIGHT TONIGHT. MODELS ALSO CONTINUE TO SHOW
STRONG UPPER LEVEL TROF DIGGING OVER THE EASTERN STATES THIS
WEEKEND BRINGING MUCH COOLER WEATHER. EXTENDED MODELS DIFFER WITH
HANDLING NEXT WEATHER SYSTEM DURING WED-FRI TIME FRAME AND
CONFIDENCE IS LOW WITH FORECAST THEN.
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
PREDAWN SURFACE MAP SHOWS 995 MB LOW PRESSURE OVER EXTREME NE OK
WITH A FRONTAL BOUNDARY EXTENDING NE INTO CENTRAL IL. TRUE WARM
FRONT WAS OVER SOUTHERN MO/TN WITH MOIST DEWPOINTS IN WARM SECTOR
SOUTH OF WARM FRONT WITH DEWPOINTS IN THE 50S/60S. SHOWERS AND
THUNDERSTORMS HAVE DEVELOPED RECENTLY OVER SW KY...FAR SOUTHERN IL
SOUTH OF I-64 AND OVER SW MO AND MOVING QUICKLY NE.
LOW PRESSURE TO EJECT NE INTO CENTRAL IL NEAR DECATUR BY 18Z/NOON
THEN DEEPEN BELOW 990 MB AT IT LIFTS TOWARD THE MI/IN/OH BORDER BY
SUNSET SWINGING A COLD FRONT THROUGH EASTERN IL THIS AFTERNOON.
WARM AIR ADVECTION DRIVEN CONVECTION TO SPREAD QUICKLY NE AHEAD OF
WARM FRONT OVER CENTRAL/SE IL THIS MORNING WITH HAIL POSSIBLE AND
COULD BE SEVERE HAIL SOUTH OF I-72. STRONG/FAST MOVING SUPERCELLS
POSSIBLE LATER THIS MORNING AND THROUGH MID AFTERNOON SE OF I-55
WITH RISK OF TORNADOES AS WELL ESPECIALLY IN SE IL FROM I-70 SE.
LARGE HAIL AND DAMAGING WIND IS 45% RISK IN SE IL WITH TORNADO
THREAT 15%. EVEN A 10% RISK OF EF2 OR STRONGER TORNADOES IN SE IL
ALONG WITH 10% RISK OF 2 INCH OR LARGER HAIL AND 75 MPH WINDS OR
STRONGER. AS LOW PRESSURE DEEPENS AND PULLS AWAY FROM CENTRAL IL
DURING THIS AFTERNOON...GRADIENT WINDS REALLY PICK UP WITH BUFKIT
SHOWING MOMENTUM TRANSFER OF 40 KTS OR HIGHER FROM MID AFTERNOON
INTO EARLY EVENING OVER EASTERN IL AND WILL ISSUE A WIND ADIVSORY
THERE FROM 2-8 PM. HIGHS TODAY RANGE FROM THE MID 40S BY GALESBURG
TO NEAR 70F BY LAWRENCEVILLE...WITH FALLING TEMPS NW OF I-55 DURING
THIS AFTERNOON.
IN ADDITION TO THE SEVERE WEATHER THREAT TODAY...WILL SEE RAIN
MIXING WITH AND CHANGING TO SNOW NW OF THE IL RIVER DURING 2-6 PM
AND THEN DIMINISH EARLY THIS EVENING. HAVE 1-2 INCHES FROM
GALESBURG TO STARK COUNTIES NW. MODELS HAVE TRENDED FURTHER SOUTH
WITH THIS DEFORMATION ZONE INTO AREAS FROM PEORIA NORTH THIS
AFTERNOON AND EARLY EVENING. PRECIPITATION SHOULD MOSTLY BE
EXITING CENTRAL IL AFTER 9 PM TONIGHT AS STRONG LOW PRESSURE PULLS
QUICKLY AWAY.
STRONG UPPER LEVEL TROF TO DIG INTO THE EASTERN STATES THIS
WEEKEND BRINGING MUCH COLDER AIR INTO THE REGION ALONG WITH A FAIR
AMOUNT OF LOW CLOUDS. CONTINUES CHANCES OF LIGHT RAIN/SNOW SHOWERS
SUNDAY AND SUNDAY EVENING BUT NOT ACCUMULATIONS AT THIS TIME WITH
CLIPPER SYSTEM. INCREASED WIND SPEEDS THIS WEEKEND WITH FAIRLY
TIGHT PRESSURE GRADIENT OVER AREA.
LONG TERM...MONDAY THROUGH FRIDAY
NOT TOO MANY CHANGES MADE TO THE EXTENDED FORECAST WITH DRY
CONDITIONS EXPECTED MONDAY THROUGH TUE NIGHT AS TEMPS WARM UP FROM
MON-WED AS UPPER LEVEL HEIGHTS RISE OVER IL. BIG DIFFERENCE WITH
GFS...GEM AND ECMWF MODELS FOR NEXT WEATHER SYSTEM BUT DOES
APPEARS WED TO BE DRIER THAN EARLIER THOUGHT AND TRIMMED BACK POPS
TO KEEP EASTERN IL DRY WED. SHOWERS AND POSSIBLE THUNDERSTORMS
FROM WED NIGHT THRU THU AND POSSIBLY LINGERING SHOWERS INTO
FRIDAY. MODELS DIVERGE WITH HOW FAST TEMPS COOL LATER NEXT WEEK
AND USED A BLEND FOR NOW SHOWING A COOLING TREND LATE IN THE WEEK.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 8 PM CST THIS EVENING FOR ILZ044>046-054>057-
061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1035 AM CST FRI MAR 2 2012
.DISCUSSION...
ISSUED 1035 AM CST FRI MAR 2 2012
SURFACE LOW CURRENTLY CENTERED JUST SOUTH OF LITCHFIELD. INITIAL
BANDS OF ELEVATED CONVECTION CONTINUE TO ARC NORTHEAST TO
CHAMPAIGN AND DANVILLE. STILL GETTING HAIL OF PEA TO DIME SIZE AT
TIMES. ASSOCIATED WARM FRONT HAS ARCHED NORTHEAST TO AROUND I-70
AND TEMPERATURES IN THE FAR SOUTHEAST CWA HAVE SURGED INTO THE 70
DEGREE RANGE...WITH DEWPOINTS AROUND 60.
LATEST HRRR SHOWING THE TRACK OF THE LOW SHOULD MOVE NORTHEAST TO
NEAR KANKAKEE BY AROUND 2 PM. HAVE BEEN SEEING RAPID DEVELOPMENT
OF SEVERE CONVECTION ACROSS SOUTHEAST MISSOURI AND SOUTHWEST
ILLINOIS IN THE WARM SECTOR...AND THIS WILL BE LIFTING NORTHEAST
ACROSS THE SOUTHEAST HALF OF THE CWA DURING THE MIDDAY AND EARLY
AFTERNOON HOURS. TORNADO WATCH CURRENTLY AFFECTING ABOUT THE
EASTERN HALF OF THE CWA...WITH THE TIME PERIOD THROUGH ABOUT 3 PM
MOST AT RISK OF SEVERE WEATHER. ACROSS THE NORTHWEST CWA...STILL
HAVE TRENDED TOWARD SOME SNOW DEVELOPMENT LATE IN THE AFTERNOON...
BUT THE DEFORMATION ZONE LIFTS QUICKLY NORTHEAST...AND HAVE BACKED
DOWN ON ANY ACCUMULATIONS UP TOWARD GALESBURG.
UPDATED ZONES/GRIDS SENT TO REFLECT LATEST CONVECTIVE TRENDS...AS
WELL AS ADJUSTING THE TEMPERATURES DUE TO THE SHARP CONTRAST
ASSOCIATED WITH THE TRACK FO THE LOW.
GEELHART
&&
.AVIATION...
ISSUED 545 AM CST FRI MAR 2 2012
VFR CONDITIONS EARLY THIS MORNING WILL DETERIORATE DURING MID AND
LATE MORNING AS SHOWERS AND THUNDERSTORMS RACE QUICKLY NE INTO
CENTRAL IL. IFR TO MVFR CEILINGS AND VISIBILITIES TO DEVELOP
BY MIDDAY AND CONTINUE THIS AFTERNOON. THUNDERSTORMS CONFINED TO
AREAS FROM I-55 EAST AND DID NOT MENTION THUNDER AT PIA. RAIN TO
MIX WITH OR CHANGE TO SNOW LATE THIS AFTERNOON AT PIA AND DIMINISH
EARLY THIS EVENING...THOUGH HEAVIER WET SNOW SHOULD STAY NORTH OF
PIA. ENE WINDS 5-10 KTS EARLY THIS MORNING TO TURN WEST THIS
AFTERNOON AND INCREASE TO 15 TO 25 KTS WITH GUSTS OF 25 TO 35 KTS
AND THEN GRADUALLY DIMINISH TO AROUND 15 KTS LATER THIS EVENING
AND OVERNIGHT. LOW CLOUDS TO DECREASE EARLY THIS EVENING BUT MVFR
CEILINGS TO PUSH SE INTO CENTRAL IL DURING OVERNIGHT.
995 MB LOW PRESSURE OVER SW MO TO MOVE NE ALONG A FRONTAL BOUNDARY
INTO CENTRAL IL...REACHING NEAR DEC BY 18Z/NOON TODAY...AND TO
NEAR THE LOWER MI/IN BORDER BY SUNSET AND SWEEP A COLD FRONT
THROUGH EASTERN IL INCLUDING CMI EARLY THIS AFTERNOON. LOW
PRESSURE DEEPENS FURTHER TO NEAR SAGINAW BAY IN NE LOWER MI BY
MIDNIGHT TONIGHT AND TO GEORGIAN BAY BY 12Z/6 AM SAT. BLUSTERY
WEST WINDS WILL CONTINUE TONIGHT INTO SAT WITH TIGHT PRESSURE
GRADIENT REMAINING OVER CENTRAL IL.
HUETTL
&&
.PREV DISCUSSION...
ISSUED 320 AM CST FRI MAR 2 2012
YET ANOTHER POWERFUL STORM SYSTEM TO IMPACT IL ON THE HEALS OF A
STRONG STORM SYSTEM THAT AFFECTED THE AREA THIS PAST TUE NIGHT.
FORECAST CONCERN IS SEVERE WEATHER THREAT WITH MODERATE RISK IN SE
IL TODAY AND SLIGHT RISK AS FAR NW AS I-55. ANOTHER ISSUE IS HOW
STRONG GRADIENT WINDS GET DURING THIS AFTERNOON/EVENING AND IF A
WIND ADVISORY IS NEEDED. YET ANOTHER CONCERN IS SNOWFALL AMOUNTS
NW OF THE IL RIVER THIS AFTERNOON AND EARLY EVENING. 00Z MODELS
COMING INTO BETTER AGREEMENT OF DEEPENING LOW PRESSURE LIFTING NE
INTO THE HEART OF IL BY 18Z/NOON TODAY AND INTO NE LOWER MI BY
SAGINAW BAY BY MIDNIGHT TONIGHT. MODELS ALSO CONTINUE TO SHOW
STRONG UPPER LEVEL TROF DIGGING OVER THE EASTERN STATES THIS
WEEKEND BRINGING MUCH COOLER WEATHER. EXTENDED MODELS DIFFER WITH
HANDLING NEXT WEATHER SYSTEM DURING WED-FRI TIME FRAME AND
CONFIDENCE IS LOW WITH FORECAST THEN.
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
PREDAWN SURFACE MAP SHOWS 995 MB LOW PRESSURE OVER EXTREME NE OK
WITH A FRONTAL BOUNDARY EXTENDING NE INTO CENTRAL IL. TRUE WARM
FRONT WAS OVER SOUTHERN MO/TN WITH MOIST DEWPOINTS IN WARM SECTOR
SOUTH OF WARM FRONT WITH DEWPOINTS IN THE 50S/60S. SHOWERS AND
THUNDERSTORMS HAVE DEVELOPED RECENTLY OVER SW KY...FAR SOUTHERN IL
SOUTH OF I-64 AND OVER SW MO AND MOVING QUICKLY NE.
LOW PRESSURE TO EJECT NE INTO CENTRAL IL NEAR DECATUR BY 18Z/NOON
THEN DEEPEN BELOW 990 MB AT IT LIFTS TOWARD THE MI/IN/OH BORDER BY
SUNSET SWINGING A COLD FRONT THROUGH EASTERN IL THIS AFTERNOON.
WARM AIR ADVECTION DRIVEN CONVECTION TO SPREAD QUICKLY NE AHEAD OF
WARM FRONT OVER CENTRAL/SE IL THIS MORNING WITH HAIL POSSIBLE AND
COULD BE SEVERE HAIL SOUTH OF I-72. STRONG/FAST MOVING SUPERCELLS
POSSIBLE LATER THIS MORNING AND THROUGH MID AFTERNOON SE OF I-55
WITH RISK OF TORNADOES AS WELL ESPECIALLY IN SE IL FROM I-70 SE.
LARGE HAIL AND DAMAGING WIND IS 45% RISK IN SE IL WITH TORNADO
THREAT 15%. EVEN A 10% RISK OF EF2 OR STRONGER TORNADOES IN SE IL
ALONG WITH 10% RISK OF 2 INCH OR LARGER HAIL AND 75 MPH WINDS OR
STRONGER. AS LOW PRESSURE DEEPENS AND PULLS AWAY FROM CENTRAL IL
DURING THIS AFTERNOON...GRADIENT WINDS REALLY PICK UP WITH BUFKIT
SHOWING MOMENTUM TRANSFER OF 40 KTS OR HIGHER FROM MID AFTERNOON
INTO EARLY EVENING OVER EASTERN IL AND WILL ISSUE A WIND ADIVSORY
THERE FROM 2-8 PM. HIGHS TODAY RANGE FROM THE MID 40S BY GALESBURG
TO NEAR 70F BY LAWRENCEVILLE...WITH FALLING TEMPS NW OF I-55 DURING
THIS AFTERNOON.
IN ADDITION TO THE SEVERE WEATHER THREAT TODAY...WILL SEE RAIN
MIXING WITH AND CHANGING TO SNOW NW OF THE IL RIVER DURING 2-6 PM
AND THEN DIMINISH EARLY THIS EVENING. HAVE 1-2 INCHES FROM
GALESBURG TO STARK COUNTIES NW. MODELS HAVE TRENDED FURTHER SOUTH
WITH THIS DEFORMATION ZONE INTO AREAS FROM PEORIA NORTH THIS
AFTERNOON AND EARLY EVENING. PRECIPITATION SHOULD MOSTLY BE
EXITING CENTRAL IL AFTER 9 PM TONIGHT AS STRONG LOW PRESSURE PULLS
QUICKLY AWAY.
STRONG UPPER LEVEL TROF TO DIG INTO THE EASTERN STATES THIS
WEEKEND BRINGING MUCH COLDER AIR INTO THE REGION ALONG WITH A FAIR
AMOUNT OF LOW CLOUDS. CONTINUES CHANCES OF LIGHT RAIN/SNOW SHOWERS
SUNDAY AND SUNDAY EVENING BUT NOT ACCUMULATIONS AT THIS TIME WITH
CLIPPER SYSTEM. INCREASED WIND SPEEDS THIS WEEKEND WITH FAIRLY
TIGHT PRESSURE GRADIENT OVER AREA.
LONG TERM...MONDAY THROUGH FRIDAY
NOT TOO MANY CHANGES MADE TO THE EXTENDED FORECAST WITH DRY
CONDITIONS EXPECTED MONDAY THROUGH TUE NIGHT AS TEMPS WARM UP FROM
MON-WED AS UPPER LEVEL HEIGHTS RISE OVER IL. BIG DIFFERENCE WITH
GFS...GEM AND ECMWF MODELS FOR NEXT WEATHER SYSTEM BUT DOES
APPEARS WED TO BE DRIER THAN EARLIER THOUGHT AND TRIMMED BACK POPS
TO KEEP EASTERN IL DRY WED. SHOWERS AND POSSIBLE THUNDERSTORMS
FROM WED NIGHT THRU THU AND POSSIBLY LINGERING SHOWERS INTO
FRIDAY. MODELS DIVERGE WITH HOW FAST TEMPS COOL LATER NEXT WEEK
AND USED A BLEND FOR NOW SHOWING A COOLING TREND LATE IN THE WEEK.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 8 PM CST THIS EVENING
FOR ILZ044>046-054>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1010 AM CST FRI MAR 2 2012
.DISCUSSION...
357 AM CST
A VERY DIFFICULT FORECAST SITUATION SHAPING UP FOR TODAY AND TONIGHT
WITH A COMBINATION OF WINTER WEATHER AND CONVECTIVE WEATHER TO
AFFECT NORTHERN ILLINOIS AND NORTHWEST INDIANA.
A SOUTHERN STREAM LOW IS TAKING SHAPE OVER THE SOUTHERN PLAINS. THE
MODELS ARE FINALLY SETTING INTO A SOLUTION OF TRACKING THE SFC LOW
FROM CENTRAL OKLAHOMA...THROUGH SOUTHERN MISSOURI THIS MORNING AND
INTO CENTRAL ILLINOIS BY AROUND NOON AND THROUGH NORTHERN INDIANA
AND INTO SOUTHERN LOWER MICHIGAN BY EARLY THIS EVENING. THE
SITUATION IS COMPLICATED BY A NORTHERN STREAM SHORT WAVE DROPPING
OUT OF THE NORTHERN PLAINS AND INTO THE WESTERN GREAT LAKES. THE
GUIDANCE IS ADVERTISING PHASING OF THE NORTHERN STREAM SYSTEM WITH
THE SOUTHERN STREAM LOW WHICH WILL LEAD TO RAPID DEEPENING OF THE
SYSTEM. THE RAPID DEEPENING OF THE LOW SHOULD NOT TAKE PLACE UNTIL
LATE THIS AFTERNOON AND INTO THE EVENING...WHEN THE LOW IS MOVING
THROUGH NORTHERN INDIANA AND INTO LOWER MICHIGAN. FOR THE
THUNDERSTORM THREAT...THE MOST LIKELY TIMING AND LOCATION OF THUNDER
WILL BE OVER THE SOUTHERN AND EASTERN PORTIONS OF THE CWA...THOUGH
THERE IS A CHANCE THAT SOME THUNDER CAN DEVELOP AS FAR NORTH AS THE
FAR SOUTHEASTERN CHICAGO SUBURBS. GIVEN THE VERY DYNAMIC SITUATION
SETTING UP...THE FAR SOUTHEASTERN PORTIONS OF THE CWA...ROUGHLY
SOUTH OF THE KANKAKEE RIVER ARE IN A SLIGHT RISK AREA FOR SEVERE
WEATHER WITH POSSIBLE DISCRETE SUPERCELL DEVELOPMENT AND THE MOST
LIKELY TIMING FOR STRONG TO SEVERE THUNDERSTORMS WILL BE DURING THE
LATE AFTERNOON HOURS.
THE WINTER WEATHER PICTURE IS A LITTLE MUDDLED BY SURFACE
TEMPERATURES AND THE GUIDANCE IS SHOWING SOME UNCERTAINTY TO THE
LOCATION OF THE RAIN/SNOW LINE. THIS MORNING...HAVE TRENDED CLOSELY
TO THE NAM SOLUTION...THOUGH THE TRACK OF THE MAIN SFC LOW IS VERY
SIMILAR SIMILAR IN MUCH OF THE SHORT RANGE GUIDANCE. FEEL FAIRLY
CONFIDENT IN A DEFORMATION ZONE FORMING NORTHWEST OF THE SFC LOW
TRACK...INITIALLY OVER ERN IOWA BY ARND NOON AND THEN SHIFT EWD INTO
THE ROCKFORD AREA THROUGH THE AFTERNOON. WITH PRECIPITABLE WATER
AMOUNTS EXPECTED TO APPROACH THREE QUARTERS OF AN INCH INVOF THE
DEFORMATION BAND...QPF VALUES SHOULD BE RELATIVELY HIGH...AND
ANTICIPATE CLOSE TO AN INCH OF STORM TOTAL LIQUID QPF FOR THE
DURATION OF THE EVENT. TOTAL SNOWFALL IN THE MAIN DEFORMATION BAND
HAS BEEN TOUGH TO GET A HANDLE ON GIVEN THE UNCERTAINTY IN THE
LOCATION OF THE RAIN/SNOW LINE AND HOW LARGE OF A TRANSITION ZONE
THERE WILL BE BETWEEN THE AREA OF ALL RAIN AND ALL SNOW. HAVE
MAINTAINED A FAIRLY BROAD TRANSITION ZONE IN THE GRIDS TO REFLECT
THE UNCERTAINTY. ONE LIMITING FACTOR FOR TOTAL ACCUMULATION WILL BE
THE INITIAL RELATIVELY WARM ENVIRONMENT AND THE TIME IT WILL TAKE
FOR THE COLDER AIR TO FILTER IN BEHIND THE SFC LOW. AT THIS POINT
HAVE GONE WITH RELATIVELY LOW RAIN/SNOW RATIOS. AT THIS
POINT...ANTICIPATE THAT THE BAND OF HEAVIEST ACCUMULATION WILL
EXTEND FROM NEAR DIXON TO ROCKFORD...WITH A BAND OF 3 TO 5 INCHES
POSSIBLE. LIGHTER AMOUNTS SHOULD EXTEND TO THE SOUTH AND
EAST...WITH 1 TO 2 INCHES NEAR THE I-88 CORRIDOR...INCLUDING THE
CHICAGO AREA. SOME LIGHTER AMOUNTS ARE POSSIBLE AS FAR SOUTH AS
I-80. GIVEN THE UNCERTAINTY OF THE TOTAL SNOWFALL AMOUNTS...WILL
LET THE WINTER STORM WATCH RIDE FOR NOW...AND WAIT TO SEE HOW
QUICKLY THE SYSTEM DEEPENS BEFORE MAKING A FINAL DECISION ON WHETHER
TO GO WITH A WINTER STORM WARNING OR AN ADVISORY.
STRONG WINDS SHOULD ALSO BE A CONCERN LATE THIS AFTERNOON AND EARLY
THIS EVENING...ESPECIALLY FOR LOCATIONS EAST OF THE I-55 CORRIDOR AS
THE SFC LOW DEEPENS AS IT TRACKS THROUGH INDIANA. AT THIS
POINT...DO NOT ANTICIPATE THE NEED FOR A WIND ADVISORY...BUT GUSTS
OF 30 TO 35 MPH...AND AN OCCASIONAL GUST TO 40 MPH...ARE LIKELY.
THIS WEEKEND THROUGH MID WEEK...
CYCLONIC FLOW WILL BE THE DOMINANT WEATHER WORD THROUGH THE WEEKEND.
BEHIND THE SYSTEM THAT WILL IMPACT THE REGION TODAY WILL BE A
SHEARED VORT LOBE THAT WILL MOVE FROM NORTHWEST TO SOUTHEAST ACROSS
THE CWA BY SATURDAY MORNING. THIS MAY BRING SOME LIGHT SNOW SHOWERS
TO AREAS NORTH OF INTERSTATE 80 THROUGHOUT THE DAY ON SATURDAY AND
SATURDAY NIGHT. MOISTURE WILL BE RELATIVELY SHALLOW AND FORCING WILL
BE WEAK...AND NOT EXPECTING MUCH BEYOND LIGHT SNOW SHOWERS TO A
LIGHT DUSTING. THE COLD NORTHWEST FLOW WILL KEEP TEMPERATURES DOWN
AND BELOW NORMAL THROUGH THE WEEKEND...AND A CONSTANT STRATUS DECK
WILL KEEP THOSE TEMPERATURES LOCKED AS IS. THE OFF AND ON CHANCES
FOR LIGHT SNOW SHOWERS WILL ALSO CONTINUE SUNDAY AS ANOTHER RIPPLE
IN THE FLOW SHOOTS DOWN THROUGH THE NORTHERN PLAINS AND ACROSS
NORTHERN ILLINOIS AND NORTHWESTERN INDIANA THROUGH THAT TIME. THE
FLIP BACK TO SPRING WILL COME CHARGING IN JUST IN
TIME FOR THE WORK WEEK. BY MONDAY AFTERNOON...AN EXPANSIVE AREA OF
HIGH PRESSURE WILL SHIFT EAST OF THE MID MISSISSIPPI VALLEY REGION
AND ACROSS THE OHIO VALLEY...ALLOWING WINDS TO BECOME SOUTHERLY.
TIGHTENING GRADIENT FLOW AT THE SURFACE AND STRONG WAA WILL SUPPORT
HIGHS TUESDAY QUICKLY JUMPING TO THE UPPER 50S TO LOW TO MID 60S.
WITH OVERNIGHT LOWS IN THE LOWER 40S. CURRENT RECORDS FOR ROCKFORD
AND OHARE FOR TUESDAY AND WEDNESDAY ARE 70 AND 78 RESPECTIVELY AND
DONT EXPECT ANY THREAT TO THOSE NUMBERS.
THE NEXT UPPER LEVEL WAVE WILL APPROACH THE REGION CLOSER TO
WEDNESDAY EVENING /SLOWER THAN EARLIER FORECASTS/ BRINGING WITH IT
THE INCREASED CHANCES FOR SHOWERS. A WEAKENING UPPER LEVEL TROUGH
WILL HELP TO PUSH THROUGH A COLD FRONT OVERNIGHT ON THURSDAY. AT
THIS POINT IT IS LOOKING LIKE ANY THUNDER THREAT WILL BE MARGINAL.
KREIN/SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CIGS LOWERING TO IFR BY MID AFTERNOON AND PERSISTING INTO
EVENING IN PRECIPITATION.
* RAIN SPREADING ACROSS TERMINALS SHORTLY AFTER 17Z.
* RAIN CHANGING TO SNOW LATE THIS AFTERNOON...WITH SNOW BEING
MODERATE TO POSSIBLY HEAVY AT TIMES INTO EARLY EVENING.
* A SMALL CHANCE FOR ICE PELLETS DURING THE RAIN TO SNOW
CHANGEOVER LATE THIS AFTERNOON.
* WINDS BACKING TO THE NORTH THIS AFTERNOON THEN BECOMING GUSTY
AND BACKING TO THE WEST BY MID EVENING.
//DISCUSSION...UPDATED 16Z...
ONLY MADE SOME MINOR CHANGES TO GOING FORECAST IN NEAR
TERM...MAINLY WITH RESPECT MOVING TIMING OF RAIN UP A COUPLE OF
HOURS WITH RAIN ALREADY SPREADING INTO THE SOUTHERN PARTS OF
CHICAGO METRO FROM THE SOUTH. TIMING OF RAIN/SNOW CHANGEOVER...
THE POTENTIAL FOR A PERIOD OF MODERATE/HEAVY SNOW INTO EARLY
EVENING...AND IFR/LIFR CONDITIONS ALL CONTINUE TO LOOK APPROPRIATE
BASED ON 12Z NAM WHICH REMAINS CONSISTENT WITH PREVIOUS THINKING.
THUNDER WILL BE LIKELY JUST OFF TO THE SOUTH OF THE TERMINALS
MIDDAY THROUGH AFTERNOON. RECENT HRRR RUNS THIS MORNING CONTINUE
TO DEPICT SOME POTENTIAL FOR CELLULAR CONVECTION INTO CHI AREA
AROUND 20Z...BUT BETTER POTENTIAL LOOKS TO BE ALONG/SOUTH OF A
PNT-GYY LINE AT THIS TIME.
RATZER
PREVIOUS DISCUSSION FROM 12Z...
A VERY ACTIVE PERIOD OF WEATHER IMPACTING AVIATION IS EXPECTED
ACROSS THE REGION THIS AFTERNOON AND EVENING. THIS WILL BE DUE TO
DEEPENING LOW PRESSURE MOVING NORTHEAST FROM SOUTHERN MO THIS
MORNING TO LOWER MI BY EVENING. THROUGH THIS MORNING...THERE WILL
BE MINIMAL IMPACTS WITH MID-LEVEL CLOUD COVER AND POSSIBLY A
PASSING SPRINKLE OR ISOLATED LIGHT SHOWER.
AS THE ENTIRE WEATHER SYSTEM BECOMES SIGNIFICANTLY BETTER
ORGANIZED THIS AFTERNOON...PRECIPITATION WILL SPREAD OVER NORTHERN
IL AND NORTHWEST IN. THIS WILL START AS RAIN AT ALL TAF SITES.
CIGS SHOULD QUICKLY DROP TO IFR OR LOW MVFR WITHIN AN HOUR OR TWO
OF THE PRECIP BEGINNING. WITH THE SYSTEM DEEPENING...COOLER AIR
WILL ALSO BE MORE RAPIDLY ENTRAINED INTO THE SYSTEM...AS WELL AS
DYNAMIC COOLING OCCURRING. THIS WILL TRANSITION RAIN TO A WET AND
POTENTIALLY HEAVY SNOW ACROSS NORTH CENTRAL IL...INCLUDING
RFD...DURING THE MIDDLE OF THIS AFTERNOON...AND ACROSS CHICAGO
AREA AIRPORTS LATE THIS AFTERNOON. THERE EVEN COULD BE A BRIEF
PERIOD OF ICE PELLETS DURING THE CHANGEOVER...BUT CONFIDENCE IN
THIS IS LOW. IN ADDITION...THUNDER IS POSSIBLE AT CHICAGO AREA
AIRPORTS AND GARY DURING THIS TIME. THE MOST ROBUST THUNDERSTORMS
ARE EXPECTED TO REMAIN SOUTH AND SOUTHEAST OF CHICAGO.
SNOWFALL RATES DURING THE TWO TO THREE HOURS AFTER TRANSITION WILL
BE MODERATE TO POTENTIALLY HEAVY...ESPECIALLY AT RFD. THE QUICK
FORWARD PROGRESS OF THE SYSTEM WILL HELP TO TAPER SNOW QUICKLY BY
MID EVENING FROM WEST TO EAST. WHILE SNOWFALL MAY ONLY LAST A FEW
HOURS...THE MODERATE TO POTENTIALLY HEAVY /GREATER THAN ONE INCH
PER HOUR/ RATES WILL LEAD TO QUICK ACCUMULATION. THIS IS
ESPECIALLY TRUE AT RFD...WHERE FOUR TO SIX INCHES ARE EXPECTED. AS
FOR AMOUNTS ANTICIPATED AT OTHER AIRFIELDS...TWO TO FOUR AT
DPA...ONE TO THREE AT ORD...AROUND ONE AT MDW...AND LESS THAN ONE
AT GYY.
WITH THE SIGNIFICANT INTENSIFICATION OF THE ENTIRE LOW PRESSURE
AREA THIS AFTERNOON AND EVENING...THE ENTIRE ATMOSPHERIC WIND
FIELD WILL RESPOND WITH A RAPID INCREASE IN MAGNITUDE. SURFACE
WINDS WILL BACK TO THE NORTH THEN NORTHWEST THROUGH THIS
AFTERNOON. THESE WILL BECOME GUSTY...ESPECIALLY LATE IN THE
AFTERNOON AND EVENING. HAVE GONE ABOVE MODEL FORECASTS FOR WINDS
WITH SUCH A RAPIDLY DEEPENING SYSTEM AND THE PATH IT IS TAKING.
WINDS ALOFT...IN THE 2000 TO 4000 FT LAYER LATE THIS AFTERNOON AND
EVENING...WILL LIKELY BE BETWEEN 35 AND 50 KTS ACROSS CHICAGO INTO
NORTHWEST INDIANA.
CIGS ARE EXPECTED TO IMPROVE LATER THIS EVENING...AND MAY COME UP
EVEN FASTER THAN THE TAF INDICATES.
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN IFR CIGS DEVELOPING BY LATE AFTERNOON.
* HIGH CONFIDENCE IN RAIN CHANGING TO SNOW. HIGH CONFIDENCE IN AT
LEAST MODERATE RATES OF SNOWFALL AT ORD...WITH MEDIUM CONFIDENCE
AT MDW. MEDIUM CONFIDENCE IN TIMING OF TRANSITION AT BOTH
AIRPORTS.
* LOW CONFIDENCE IN ICE PELLET CHANCES. HIGH CONFIDENCE THAT IF
ICE PELLETS OCCUR THAT THE PERIOD WOULD BE BRIEF.
* HIGH CONFIDENCE IN WIND TRENDS. MEDIUM CONFIDENCE IN SPEEDS AND
GUSTS.
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
* SUNDAY...CHANCE OF MVFR WITH SNOW SHOWERS.
* MONDAY AND TUESDAY...VFR.
* WEDNESDAY...GUSTY SOUTHERLY WINDS. CHANCE OF RAIN SHOWERS.
* THURSDAY...CHANCE OF MVFR IN RAIN.
MTF
&&
.MARINE...
241 AM CST
STRONG LOW PRESSURE SYSTEM TO IMPACT THE REGION TODAY BRINGING
STRONG GALES AND POSSIBLY STORM FORCE WINDS TO THE LOWER HALF OF
LAKE MICHIGAN. THIS MORNING LOW PRESSURE IS CENTERED OVER CENTRAL
OKLAHOMA AND IS FORECAST TO LIFT NORTHEAST AND RAPIDLY DEEPEN. THIS
LOW WILL PASS JUST SOUTH OF LAKE MICHIGAN LATE THIS EVENING...
CONTINUING TO DEEPEN AS IT PUSHES ACROSS MICHIGAN TONIGHT. TIGHT
PRESSURE GRADIENT DEVELOPS ON THE NORTHWEST QUADRANT OF THE LOW WITH
VERY STRONG PRESSURE FALL/RISE COUPLET HELPING TO FURTHER ENHANCE
WINDS ACROSS THE SOUTHERN HALF OF THE LAKE. GUIDANCE SUGGESTS WINDS
OF 50 TO 55 KTS AT THE TOP OF THE MIXED LAYER FOR A BRIEF PERIOD
WHICH COULD MIX DOWN TO THE LAKE SURFACE. OUTSIDE OF THIS VERY SHORT
WINDOW WHERE STORM FORCE WINDS ARE POSSIBLE...MAINLY LOOKING AT HIGH
END GALE EVENT WITH WINDS 40 TO 45 KT FROM THIS EVENING THROUGH
EARLY SATURDAY MORNING. WILL UPGRADE THE GALE WATCH TO A WARNING AND
ALSO EXPAND INTO THE NEARSHORE WATERS.
WINDS DIMINISH SUNDAY AND MONDAY AS SURFACE RIDGE MOVES ACROSS THE
LAKE. WINDS INCREASE AGAIN TUESDAY AND WEDNESDAY AS ANOTHER LOW
PRESSURE SYSTEM PUSHES EAST ACROSS THE CANADIAN PRAIRIES THEN INTO
HUDSON BAY. BROAD HIGH PRESSURE WILL THEN DEVELOP ACROSS THE PLAINS
AND UPPER MIDWEST TO END OUT THE WEEK. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ013-ILZ014...3 PM FRIDAY TO
MIDNIGHT SATURDAY.
WINTER WEATHER ADVISORY...ILZ010-ILZ011-ILZ012...3 PM FRIDAY TO
9 PM FRIDAY.
WINTER STORM WATCH...ILZ003-ILZ004-ILZ008...3 PM FRIDAY TO 9 PM
FRIDAY.
WINTER STORM WATCH...ILZ005-ILZ006...3 PM FRIDAY TO MIDNIGHT
SATURDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...5 PM
FRIDAY TO 3 PM SATURDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...5 PM
FRIDAY TO 3 AM SATURDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 5 PM FRIDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...3 PM FRIDAY TO 5
PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
450 PM EST FRI MAR 2 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...A STRONG LOW PRESSURE SYSTEM WILL KEEP STORMS IN THE
AREA FOR THE NEXT FEW HOURS...THEN STRONG WINDS SHOULD REMAIN IN ITS
WAKE INTO THE NIGHT. THIS WILL USHER IN MUCH COLDER AIR FOR THE
WEEKEND BEFORE UPPER RIDGING BRINGS WARMER AIR AND ANOTHER SYSTEM
MOVES IN WITH CHANCES FOR RAIN MID WEEK.
&&
.NEAR TERM /THIS AFTERNOON THROUGH TONIGHT/...
SEVERE THREAT CONTINUES. THUNDERSTORMS...SOME SEVERE...ONGOING
ACROSS MUCH OF THE FORECAST AREA. THE COLD FRONT LAGS THESE BY QUITE
A BIT AND THERE IS CLEARING IN THE MIDDLE WHERE RAPID REFRESH IS
SHOWING SOME REDEVELOPMENT SO MAY NOT BE ABLE TO CLEAR OUT RISK
UNTIL A BIT LATER. STILL LOOKS LIKE EVERYTHING WILL BE OUT OF THE
AREA BY 0Z BUT WILL CONTINUE TO CARRY A CHANCE IN THE EAST SINCE
TORNADO WATCH THERE RUNS UNTIL 2Z BUT EXPECT TO BE ABLE TO CANCEL
THAT EARLY. WINDS WILL PICK UP BEHIND THE FRONT WITH TIGHT PRESSURE
GRADIENT IN THE WAKE OF THE SURFACE LOW THAT WILL CONTINUE TO
STRENGTHEN TONIGHT AS IT MOVES NORTHEAST ACROSS MICHIGAN AND WILL
CONTINUE WIND ADVISORY THROUGH 3Z. MAY HAVE TO EXTEND AS GUSTS MAY
NOT BE DONE BY THEN BUT WILL REEVALUATE THIS ONCE TORNADO WATCHES
DROP TO AVOID ANY CONFUSION.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
STRONG COLD UPPER TROUGH WILL BE OVER THE AREA FOR SATURDAY THROUGH
SUNDAY. 850 MB TEMPERATURES DROP TO -10 TO -12 C FOR MUCH OF THE
SHORT TERM...AND WITH STRENGTH OF SYSTEM MOVING THROUGH CURRENTLY
THINK THIS IS LEGITIMATE. THEREFORE WILL STICK TO COLD END OF
GUIDANCE OR GO A COUPLE DEGREES COOLER AT TIMES. WITH LITTLE SHORT
WAVES MOVING THROUGH THE UPPER TROUGH IN THE NORTH WILL ADD A SLIGHT
CHANCE FOR SNOW ACROSS THE NORTHERN COUNTIES FOR SATURDAY AND
FLURRIES FOR LATE SATURDAY NIGHT. FOR SUNDAY WILL CONTINUE TO CARRY
CHANCE POPS BUT WITH TEMPERATURES LOOKING COLDER WILL SEE SNOW
ACROSS THE NORTH...A MIX CENTRAL AND CHANGEOVER TO ALL RAIN ONLY IN
THE SOUTH. LOOKS LIKE THE BACK END OF THE TROUGH WILL MOVE THROUGH
SUNDAY NIGHT SO WILL INCLUDE A SLIGHT CHANCE OF SNOW THEN.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
ACCEPTED CR INITIALIZATION AS IS DUE TO SEVERE WEATHER. ABOVE NORMAL
TEMPERATURES AND CHANCES FOR RAIN WITH A SYSTEM FROM MID WEEK ON.
&&
.AVIATION /DISCUSSION FOR 022200Z TAF UPDATE/...
REMOVED ALL CBS AND ANY MENTION OF THUNDER FROM SITES AS ALL IS EAST
OF THE TERMINALS. ADDED LOW MVFR CLOUD DECK MOVING IN OVER THE NEXT
COUPLE OF HOURS BASED ON SATELLITE LOOP AND ALSO BROUGHT STRONGER
WINDS IN FASTER BASED ON UPSTREAM OBSERVATIONS.
18Z DISCUSSION FOLLOWS...
RAPIDLY DETERIORATING CONDITIONS WITHIN SEVERE CONVECTION WILL
IMPACT ALL TERMINALS THIS AFTERNOON. MAINLY VFR OVERNIGHT INTO
SATURDAY MORNING.
WARM FRONT CURRENTLY PROGRESSING NORTH THROUGH THE FORECAST AREA
LATE THIS MORNING WITH CONVECTION ALONG AND NORTH OF THE BOUNDARY.
AS OF 1630Z...KLAF IS THE ONLY TERMINAL BEING DIRECTLY IMPACTED BY
THIS CONVECTION. HRRR HAS A NICE HANDLE ON CURRENT ACTIVITY...WITH
EXPECTATION THAT CONVECTION ACROSS NORTHERN COUNTIES MOVES OUT OF
THE FORECAST AREA BY 18-19Z. FOCUS THOUGH ALREADY SHIFTING TO
ALONG THE COLD FRONT OVER SOUTHEAST MISSOURI WHERE SEVERE
CONVECTION IS ALREADY RAPIDLY DEVELOPING. THIS ACTIVITY WILL
QUICKLY SPREAD NORTHEAST WITH ADDITIONAL CONVECTION LIKELY
DEVELOPING OUT IN FRONT OF THE MAIN LINE. AFTER A PERIOD WITH
FILTERED SUNSHINE EARLY THIS AFTERNOON...EXPECT IMPACTS FROM
CONVECTION AT ALL TERMINALS AFTER 19Z AND CONTINUING THROUGH 00Z.
STORMS WILL BE FAST MOVERS...CAPABLE OF PRODUCING SEVERE WIND
GUSTS AND CAUSING CONDITIONS AT THE TERMINALS TO DROP RAPIDLY TO
VLIFR AT TIMES. OUTSIDE OF CONVECTION...THE INTENSIFYING NATURE OF
THE LOW PRESSURE WILL CREATE STRONG WIND GUSTS UP TO 35-40KTS INTO
THE EARLY EVENING. WILL UPDATE TAFS AS NEEDED THROUGH THE AFTERNOON.
STORMS WILL BE EAST OF THE AREA AFTER 00Z WITH SKIES BECOMING
PARTLY CLOUDY AS MUCH DRIER AIR FILTERS INTO THE AREA. WIND GUSTS
WILL STAY UP THROUGH THE EVENING...EVENTUALLY DROPPING OFF TO
20-25KT OVERNIGHT AS WINDS VEER TO A MORE WESTERLY DIRECTION.
STRATOCU WILL REDEVELOP AND EXPAND BACK INTO THE TERMINALS
SATURDAY MORNING AS REGION GETS INTO CYCLONIC FLOW ON BACK SIDE OF
THE LOW PRESSURE. MAY SEE MVFR CEILINGS DEVELOP AT BOTH KHUF AND
KLAF. WESTERLY WIND GUSTS TO 25KTS WILL CONTINUE AS WELL.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....CP
AVIATION...RYAN/CP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
329 PM EST FRI MAR 2 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...A STRONG LOW PRESSURE SYSTEM WILL KEEP STORMS IN THE AREA FOR THE
NEXT FEW HOURS...THEN STRONG WINDS SHOULD REMAIN IN ITS WAKE INTO
THE NIGHT. THIS WILL USHER IN MUCH COLDER AIR FOR THE WEEKEND BEFORE
UPPER RIDGING BRINGS WARMER AIR AND ANOTHER SYSTEM MOVES IN WITH
CHANCES FOR RAIN MID WEEK.
&&
.NEAR TERM /THIS AFTERNOON THROUGH TONIGHT/...
SEVERE THREAT CONTINUES. THUNDERSTORMS...SOME SEVERE...ONGOING
ACROSS MUCH OF THE FORECAST AREA. THE COLD FRONT LAGS THESE BY QUITE
A BIT AND THERE IS CLEARING IN THE MIDDLE WHERE RAPID REFRESH IS
SHOWING SOME REDEVELOPMENT SO MAY NOT BE ABLE TO CLEAR OUT RISK
UNTIL A BIT LATER. STILL LOOKS LIKE EVERYTHING WILL BE OUT OF THE
AREA BY 0Z BUT WILL CONTINUE TO CARRY A CHANCE IN THE EAST SINCE
TORNADO WATCH THERE RUNS UNTIL 2Z BUT EXPECT TO BE ABLE TO CANCEL
THAT EARLY. WINDS WILL PICK UP BEHIND THE FRONT WITH TIGHT PRESSURE
GRADIENT IN THE WAKE OF THE SURFACE LOW THAT WILL CONTINUE TO
STRENGTHEN TONIGHT AS IT MOVES NORTHEAST ACROSS MICHIGAN AND WILL
CONTINUE WIND ADVISORY THROUGH 3Z. MAY HAVE TO EXTEND AS GUSTS MAY
NOT BE DONE BY THEN BUT WILL REEVALUATE THIS ONCE TORNADO WATCHES
DROP TO AVOID ANY CONFUSION.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
STRONG COLD UPPER TROUGH WILL BE OVER THE AREA FOR SATURDAY THROUGH
SUNDAY. 850 MB TEMPERATURES DROP TO -10 TO -12 C FOR MUCH OF THE
SHORT TERM...AND WITH STRENGTH OF SYSTEM MOVING THROUGH CURRENTLY
THINK THIS IS LEGITIMATE. THEREFORE WILL STICK TO COLD END OF
GUIDANCE OR GO A COUPLE DEGREES COOLER AT TIMES. WITH LITTLE SHORT
WAVES MOVING THROUGH THE UPPER TROUGH IN THE NORTH WILL ADD A SLIGHT
CHANCE FOR SNOW ACROSS THE NORTHERN COUNTIES FOR SATURDAY AND
FLURRIES FOR LATE SATURDAY NIGHT. FOR SUNDAY WILL CONTINUE TO CARRY
CHANCE POPS BUT WITH TEMPERATURES LOOKING COLDER WILL SEE SNOW
ACROSS THE NORTH...A MIX CENTRAL AND CHANGEOVER TO ALL RAIN ONLY IN
THE SOUTH. LOOKS LIKE THE BACK END OF THE TROUGH WILL MOVE THROUGH
SUNDAY NIGHT SO WILL INCLUDE A SLIGHT CHANCE OF SNOW THEN.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
ACCEPTED CR INITIALIZATION AS IS DUE TO SEVERE WEATHER. ABOVE NORMAL
TEMPERATURES AND CHANCES FOR RAIN WITH A SYSTEM FROM MID WEEK ON.
&&
.AVIATION /DISCUSSION FOR 022100Z TAF UPDATE/...
CONVECTION HAS MOVED EAST OF THE TERMINALS AS OF 2030Z. COLD FRONT
REMAINS OVER EASTERN ILLINOIS AND A WELL DEFINED CLEAR SLOT
PROGRESSING EAST IN FRONT OF IT. HAVE REMOVED TEMPO GROUPS FOR
CONVECTION AT ALL BUT KBMG BUT HAVE LEFT VCTS IN FOR THE NEXT FEW
HOURS TO ACCOUNT FOR ANY REDEVELOPMENT AHEAD OF THE FRONT.
READJUSTED CEILINGS AND WINDS AS WELL.
18Z DISCUSSION FOLLOWS.
RAPIDLY DETERIORATING CONDITIONS WITHIN SEVERE CONVECTION WILL
IMPACT ALL TERMINALS THIS AFTERNOON. MAINLY VFR OVERNIGHT INTO
SATURDAY MORNING.
WARM FRONT CURRENTLY PROGRESSING NORTH THROUGH THE FORECAST AREA
LATE THIS MORNING WITH CONVECTION ALONG AND NORTH OF THE BOUNDARY.
AS OF 1630Z...KLAF IS THE ONLY TERMINAL BEING DIRECTLY IMPACTED BY
THIS CONVECTION. HRRR HAS A NICE HANDLE ON CURRENT ACTIVITY...WITH
EXPECTATION THAT CONVECTION ACROSS NORTHERN COUNTIES MOVES OUT OF
THE FORECAST AREA BY 18-19Z. FOCUS THOUGH ALREADY SHIFTING TO
ALONG THE COLD FRONT OVER SOUTHEAST MISSOURI WHERE SEVERE
CONVECTION IS ALREADY RAPIDLY DEVELOPING. THIS ACTIVITY WILL
QUICKLY SPREAD NORTHEAST WITH ADDITIONAL CONVECTION LIKELY
DEVELOPING OUT IN FRONT OF THE MAIN LINE. AFTER A PERIOD WITH
FILTERED SUNSHINE EARLY THIS AFTERNOON...EXPECT IMPACTS FROM
CONVECTION AT ALL TERMINALS AFTER 19Z AND CONTINUING THROUGH 00Z.
STORMS WILL BE FAST MOVERS...CAPABLE OF PRODUCING SEVERE WIND
GUSTS AND CAUSING CONDITIONS AT THE TERMINALS TO DROP RAPIDLY TO
VLIFR AT TIMES. OUTSIDE OF CONVECTION...THE INTENSIFYING NATURE OF
THE LOW PRESSURE WILL CREATE STRONG WIND GUSTS UP TO 35-40KTS INTO
THE EARLY EVENING. WILL UPDATE TAFS AS NEEDED THROUGH THE AFTERNOON.
STORMS WILL BE EAST OF THE AREA AFTER 00Z WITH SKIES BECOMING
PARTLY CLOUDY AS MUCH DRIER AIR FILTERS INTO THE AREA. WIND GUSTS
WILL STAY UP THROUGH THE EVENING...EVENTUALLY DROPPING OFF TO
20-25KT OVERNIGHT AS WINDS VEER TO A MORE WESTERLY DIRECTION.
STRATOCU WILL REDEVELOP AND EXPAND BACK INTO THE TERMINALS
SATURDAY MORNING AS REGION GETS INTO CYCLONIC FLOW ON BACK SIDE OF
THE LOW PRESSURE. MAY SEE MVFR CEILINGS DEVELOP AT BOTH KHUF AND
KLAF. WESTERLY WIND GUSTS TO 25KTS WILL CONTINUE AS WELL.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....CP
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
307 PM EST FRI MAR 2 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM
AND LONG TERM SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...A STRONG LOW PRESSURE SYSTEM WILL KEEP STORMS IN THE AREA FOR THE
NEXT FEW HOURS...THEN STRONG WINDS SHOULD REMAIN IN ITS WAKE INTO
THE NIGHT. THIS WILL USHER IN MUCH COLDER AIR FOR THE WEEKEND BEFORE
UPPER RIDGING BRINGS WARMER AIR AND ANOTHER SYSTEM MOVES IN WITH
CHANCES FOR RAIN MID WEEK.
&&
.NEAR TERM /THIS AFTERNOON THROUGH TONIGHT/...
SEVERE THREAT CONTINUES. THUNDERSTORMS...SOME SEVERE...ONGOING
ACROSS MUCH OF THE FORECAST AREA. THE COLD FRONT LAGS THESE BY QUITE
A BIT AND THERE IS CLEARING IN THE MIDDLE WHERE RAPID REFRESH IS
SHOWING SOME REDEVELOPMENT SO MAY NOT BE ABLE TO CLEAR OUT RISK
UNTIL A BIT LATER. STILL LOOKS LIKE EVERYTHING WILL BE OUT OF THE
AREA BY 0Z BUT WILL CONTINUE TO CARRY A CHANCE IN THE EAST SINCE
TORNADO WATCH THERE RUNS UNTIL 2Z BUT EXPECT TO BE ABLE TO CANCEL
THAT EARLY. WINDS WILL PICK UP BEHIND THE FRONT WITH TIGHT PRESSURE
GRADIENT IN THE WAKE OF THE SURFACE LOW THAT WILL CONTINUE TO
STRENGTHEN TONIGHT AS IT MOVES NORTHEAST ACROSS MICHIGAN AND WILL
CONTINUE WIND ADVISORY THROUGH 3Z. MAY HAVE TO EXTEND AS GUSTS MAY
NOT BE DONE BY THEN BUT WILL REEVALUATE THIS ONCE TORNADO WATCHES
DROP TO AVOID ANY CONFUSION.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
STRONG COLD UPPER TROUGH WILL BE OVER THE AREA FOR SATURDAY THROUGH
SUNDAY. 850 MB TEMPERATURES DROP TO -10 TO -12 C FOR MUCH OF THE
SHORT TERM...AND WITH STRENGTH OF SYSTEM MOVING THROUGH CURRENTLY
THINK THIS IS LEGITIMATE. THEREFORE WILL STICK TO COLD END OF
GUIDANCE OR GO A COUPLE DEGREES COOLER AT TIMES. WITH LITTLE SHORT
WAVES MOVING THROUGH THE UPPER TROUGH IN THE NORTH WILL ADD A SLIGHT
CHANCE FOR SNOW ACROSS THE NORTHERN COUNTIES FOR SATURDAY AND
FLURRIES FOR LATE SATURDAY NIGHT. FOR SUNDAY WILL CONTINUE TO CARRY
CHANCE POPS BUT WITH TEMPERATURES LOOKING COLDER WILL SEE SNOW
ACROSS THE NORTH...A MIX CENTRAL AND CHANGEOVER TO ALL RAIN ONLY IN
THE SOUTH. LOOKS LIKE THE BACK END OF THE TROUGH WILL MOVE THROUGH
SUNDAY NIGHT SO WILL INCLUDE A SLIGHT CHANCE OF SNOW THEN.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
ACCEPTED CR INITIALIZATION AS IS DUE TO SEVERE WEATHER. ABOVE NORMAL
TEMPERATURES AND CHANCES FOR RAIN WITH A SYSTEM FROM MID WEEK ON.
&&
.AVIATION /DISCUSSION FOR 021800Z TAF ISSUANCE/...
RAPIDLY DETERIORATING CONDITIONS WITHIN SEVERE CONVECTION WILL
IMPACT ALL TERMINALS THIS AFTERNOON. MAINLY VFR OVERNIGHT INTO
SATURDAY MORNING.
WARM FRONT CURRENTLY PROGRESSING NORTH THROUGH THE FORECAST AREA
LATE THIS MORNING WITH CONVECTION ALONG AND NORTH OF THE BOUNDARY.
AS OF 1630Z...KLAF IS THE ONLY TERMINAL BEING DIRECTLY IMPACTED BY
THIS CONVECTION. HRRR HAS A NICE HANDLE ON CURRENT ACTIVITY...WITH
EXPECTATION THAT CONVECTION ACROSS NORTHERN COUNTIES MOVES OUT OF
THE FORECAST AREA BY 18-19Z. FOCUS THOUGH ALREADY SHIFTING TO
ALONG THE COLD FRONT OVER SOUTHEAST MISSOURI WHERE SEVERE
CONVECTION IS ALREADY RAPIDLY DEVELOPING. THIS ACTIVITY WILL
QUICKLY SPREAD NORTHEAST WITH ADDITIONAL CONVECTION LIKELY
DEVELOPING OUT IN FRONT OF THE MAIN LINE. AFTER A PERIOD WITH
FILTERED SUNSHINE EARLY THIS AFTERNOON...EXPECT IMPACTS FROM
CONVECTION AT ALL TERMINALS AFTER 19Z AND CONTINUING THROUGH 00Z.
STORMS WILL BE FAST MOVERS...CAPABLE OF PRODUCING SEVERE WIND
GUSTS AND CAUSING CONDITIONS AT THE TERMINALS TO DROP RAPIDLY TO
VLIFR AT TIMES. OUTSIDE OF CONVECTION...THE INTENSIFYING NATURE OF
THE LOW PRESSURE WILL CREATE STRONG WIND GUSTS UP TO 35-40KTS INTO
THE EARLY EVENING. WILL UPDATE TAFS AS NEEDED THROUGH THE AFTERNOON.
STORMS WILL BE EAST OF THE AREA AFTER 00Z WITH SKIES BECOMING
PARTLY CLOUDY AS MUCH DRIER AIR FILTERS INTO THE AREA. WIND GUSTS
WILL STAY UP THROUGH THE EVENING...EVENTUALLY DROPPING OFF TO
20-25KT OVERNIGHT AS WINDS VEER TO A MORE WESTERLY DIRECTION.
STRATOCU WILL REDEVELOP AND EXPAND BACK INTO THE TERMINALS
SATURDAY MORNING AS REGION GETS INTO CYCLNIC FLOW ON BACK SIDE OF
THE LOW PRESSURE. MAY SEE MVFR CEILINGS DEVELOP AT BOTH KHUF AND
KLAF. WESTERLY WIND GUSTS TO 25KTS WILL CONTINUE AS WELL.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....CP
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1154 AM EST FRI MAR 2 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL MOVE INTO LOWER MICHIGAN
TODAY...BRINGING SEVERE WEATHER TO THE OHIO VALLEY TODAY ALONG WITH
GUSTY WINDS OUTSIDE OF THUNDERSTORMS. MUCH COLDER AIR WILL THEN MOVE
IN FOR THE WEEKEND...WITH A WEAK SYSTEM BRINGING A CHANCE FOR RAIN
AND SNOW SUNDAY.
WARMER WEATHER WILL RETURN DURING NEXT WEEK...WITH CHANCES FOR RAIN
RETURNING BY THE END OF NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/... ONGOING STORMS ACROSS THE AREA AT
15Z...SOME OF WHICH ARE PRODUCING LARGE HAIL. THE WARM
FRONT...WHICH AT 15Z STRETCHED FROM SULLIVAN TO BLOOMINGTON TO
SEYMOUR...WILL CONTINUE TO LIFT NORTHWARD AND DEW POINTS BEHIND
THE FRONT ARE INCREASING TO THE MID 50S TO LOW 60S CURRENTLY
ACROSS SOUTHERN INDIANA WITH TEMPERATURES IN THE LOW TO MID 60S
AND THIS AIR WILL BE ADVECTING NORTH INTO THE AREA. WITH THIS
UNSTABLE AIR AND THE DYNAMIC STRENGTHENING LOW CENTERED OVER ST
LOUIS AT 15Z PROGGED TO MOVE JUST NORTHWEST OF THE AREA AND DRAG A
COLD FRONT THROUGH CENTRAL INDIANA BETWEEN 20Z IN THE WEST AND 0Z
IN THE EAST. SURFACE BASED CAPE COULD CLIMB TO NEAR 1000 AND NEAR
2000 ACROSS THE SOUTH...AND 0-1 KM HELICITY AND 0-3 KM HELICITY
VALUES ARE PROGGED TO BE IN THE 300 /FOR 0 TO 1/ AND 500 /FOR 0 TO
3/ RANGE IN THE WARM SECTOR AND AHEAD OF/ALONG THE COLD FRONT.
THUS THE THREAT FOR SEVERE WEATHER WILL GET EVEN MORE SIGNIFICANT
THIS AFTERNOON WITH THE THREAT FOR TORNADOES...LARGE HAIL OF 2
INCHES IN DIAMETER OR MORE...AND DAMAGING WINDS IN EXCESS OF 65
MPH BEING LIKELY IN SOME STORMS. THIS IS A DANGEROUS SITUATION AND
SHOULD NOT BE TAKEN LIGHTLY.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
FOCUS IS ON WIND/RAIN EARLY THEN ON CHANCES FOR PRECIPITATION LATE
IN THE PERIOD. MODELS ARE IN GOOD AGREEMENT EARLY BUT DIFFER SOME
WITH SUNDAY/S SYSTEM. TOOK A BLEND THERE AS UNCERTAINTY IS HIGH
ENOUGH NOT TO FAVOR ONE SOLUTION OVER ANOTHER.
THE STRONG PRESSURE RISES /OVER 10MB IN 6 HOURS/ WILL OCCUR INTO THE
EVENING HOURS. BUFKIT STILL SHOWS GUSTS 35-40KT EARLY. THUS WILL
CONTINUE THE WIND ADVISORY UNTIL 03Z.
PRECIPITATION SHOULD END QUICKLY BEHIND THE FRONT...AND WRAP-AROUND
MOISTURE SHOULD STAY MAINLY NORTH OF THE AREA. THUS FEEL CHANCES FOR
RAIN AFTER 00Z ARE LOW. MOS POPS ARE BELOW 20 PERCENT. WILL CARRY
LOW POPS FOR A FEW HOURS THIS EVENING JUST IN CASE SOMETHING
LINGERS...BUT BELIEVE MOST AREAS WILL REMAIN DRY AFTER 00Z.
DRY AND PARTLY TO MOSTLY CLOUDY CONDITIONS WILL THEN PERSIST FOR
SATURDAY AND SATURDAY NIGHT. A WEAK CLIPPER-LIKE SYSTEM WILL DIVE
SOUTHEAST IN THE SUNDAY-SUNDAY NIGHT TIME FRAME. WITH UNCERTAINTIES
IN LOCATION AND TIMING DECIDED JUST TO GO WITH LOW POPS BOTH
PERIODS. WENT RAIN AND SNOW MOST AREAS SUNDAY AND THEN JUST SNOW
SUNDAY NIGHT GIVEN EXPECTED THERMAL PROFILES.
FOR TEMPERATURES...GENERALLY STUCK WITH A MODEL BLEND AS THIS WORKS
WELL GIVEN EXPECTED CONDITIONS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
MAIN CHALLENGE TO THE EXTENDED WILL BE WHETHER TO KEEP POPS IN
MONDAY AS AN UPPER TROUGH MOVES EAST OF CENTRAL INDIANA AND ALSO
POPS AND QPF STARTING WEDNESDAY NIGHT.
DECIDED TO PULL SLIGHT CHANCE POPS ON MONDAY PER THE CENTRAL
REGIONAL INITIALIZATION EXTENDED AS ALL THE EXTENDED 00Z MODEL RUNS
NOW HAVE THE TROUGH WELL EAST OF CENTRAL INDIANA ACROSS THE ATLANTIC
SEABOARD BY 00Z TUESDAY WITH RIDGING BUILDING IN ACROSS THE GREAT
LAKES AND OHIO VALLEY. IN ADDITION...THE FORECAST AREA WILL BE UNDER
THE INFLUENCE OF SURFACE HIGH PRESSURE AND MOISTURE IS NOT
IMPRESSIVE.
THE MIDDLE OF THE WEEK CONTINUES TO LOOK DRY WITH FAST SOUTHWEST
FLOW DEVELOPING. IN ADDITION...IT SHOULD BE WARMER EACH DAY WITH
THERMAL RIDGE EXTENDING NORTHEAST FROM TEXAS TO THE OHIO VALLEY AND
GREAT LAKES BY WEDNESDAY. 1000-850 MILLIBAR THICKNESSES AND
850 TEMPERATURES APPROACH 1350 METERS AND 6 DEGREES CELSIUS
RESPECTIVELY ON WEDNESDAY. THE CR INITIALIZATION REFLECTS THIS
NICELY WITH BELOW NORMAL TEMPERATURES ON MONDAY BECOMING MILD
ALREADY BY TUESDAY.
FINALLY...THE 00Z ECMWF IS NOW TRENDING TOWARDS THE GFS AND GFS
ENSEMBLES WITH A CUTOFF LOW ACROSS THE SOUTHWESTERN UNITED STATES BY
MIDWEEK...MOVING INTO WEST TEXAS ON THURSDAY. HOWEVER...THE ECMWF IS
A BIT FURTHER SOUTH AND CONTINUES TO ALLOW A SHARP UPPER TROUGH TO
MOVE ACROSS THE UPPER MIDWEST AND GREAT LAKES OVER THE WEEKEND AND
CONSEQUENTLY PUSHES A COLD FRONT THROUGH ON THURSDAY...WHILE THE GFS
ONLY HAS AN INVERTED TROUGH WELL WEST OF THE FORECAST AREA AT THAT
TIME. EITHER WAY...MODELS HAVE QPF ACROSS PARTS OR ALL OF CENTRAL
INDIANA WEDNESDAY NIGHT THROUGH FRIDAY. HOWEVER...THE QUICKER AND
STRONGER SURFACE REFLECTION OF THE EURO FAVORS MORE QPF. AT THIS
TIME...DID NOT CHANGE ANYTHING BEYOND MONDAY FROM THE INITIALIZATION
DUE TO BIG MODEL SYNOPTIC DIFFERENCES WHICH LEADS TO LOW CONFIDENCE
NOT ONLY WITH POPS AND QPF BUT ALSO WITH TEMPERATURES ON FRIDAY...
AS THE ECMWF IS BRINGING IN COLDER POST FRONTAL AIR...WHILE THE
GFS...AS STATED EARLIER...IS SLOWER AND NOT AS STRONG WITH THE
SURFACE PATTERN.
&&
.AVIATION /DISCUSSION FOR 021800Z TAF ISSUANCE/...
RAPIDLY DETERIORATING CONDITIONS WITHIN SEVERE CONVECTION WILL
IMPACT ALL TERMINALS THIS AFTERNOON. MAINLY VFR OVERNIGHT INTO
SATURDAY MORNING.
WARM FRONT CURRENTLY PROGRESSING NORTH THROUGH THE FORECAST AREA
LATE THIS MORNING WITH CONVECTION ALONG AND NORTH OF THE BOUNDARY.
AS OF 1630Z...KLAF IS THE ONLY TERMINAL BEING DIRECTLY IMPACTED BY
THIS CONVECTION. HRRR HAS A NICE HANDLE ON CURRENT ACTIVITY...WITH
EXPECTATION THAT CONVECTION ACROSS NORTHERN COUNTIES MOVES OUT OF
THE FORECAST AREA BY 18-19Z. FOCUS THOUGH ALREADY SHIFTING TO
ALONG THE COLD FRONT OVER SOUTHEAST MISSOURI WHERE SEVERE
CONVECTION IS ALREADY RAPIDLY DEVELOPING. THIS ACTIVITY WILL
QUICKLY SPREAD NORTHEAST WITH ADDITIONAL CONVECTION LIKELY
DEVELOPING OUT IN FRONT OF THE MAIN LINE. AFTER A PERIOD WITH
FILTERED SUNSHINE EARLY THIS AFTERNOON...EXPECT IMPACTS FROM
CONVECTION AT ALL TERMINALS AFTER 19Z AND CONTINUING THROUGH 00Z.
STORMS WILL BE FAST MOVERS...CAPABLE OF PRODUCING SEVERE WIND
GUSTS AND CAUSING CONDITIONS AT THE TERMINALS TO DROP RAPIDLY TO
VLIFR AT TIMES. OUTSIDE OF CONVECTION...THE INTENSIFYING NATURE OF
THE LOW PRESSURE WILL CREATE STRONG WIND GUSTS UP TO 35-40KTS INTO
THE EARLY EVENING. WILL UPDATE TAFS AS NEEDED THROUGH THE AFTERNOON.
STORMS WILL BE EAST OF THE AREA AFTER 00Z WITH SKIES BECOMING
PARTLY CLOUDY AS MUCH DRIER AIR FILTERS INTO THE AREA. WIND GUSTS
WILL STAY UP THROUGH THE EVENING...EVENTUALLY DROPPING OFF TO
20-25KT OVERNIGHT AS WINDS VEER TO A MORE WESTERLY DIRECTION.
STRATOCU WILL REDEVELOP AND EXPAND BACK INTO THE TERMINALS
SATURDAY MORNING AS REGION GETS INTO CYCLNIC FLOW ON BACK SIDE OF
THE LOW PRESSURE. MAY SEE MVFR CEILINGS DEVELOP AT BOTH KHUF AND
KLAF. WESTERLY WIND GUSTS TO 25KTS WILL CONTINUE AS WELL.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 10 PM EST THIS EVENING
FOR INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...50
NEAR TERM...CP
SHORT TERM...50
LONG TERM....MK
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
802 PM MST SAT MAR 3 2012
.UPDATE...
ISSUED AT 746 PM MST SAT MAR 3 2012
JUST COMPLETED AN UPDATE. FAIRLY COMPLICATED LOW TEMPERATURE
FORECAST HAS DEVELOPED. WINDS HAVE DROPPED OFF DRAMATICALLY AND
LESS THAT WAS EARLIER DEPICTED. ALSO INCOMING SHORTWAVE TROUGH AND
LEFT FRONT QUADRANT OF MID/UPPER LEVEL JET IS PRODUCING A THICK
MID LEVEL CEILING. WHERE THERE ARE NO CLOUDS THE TEMPERATURES HAVE
DROPPED TO NEAR FORECAST MINS. WHERE THE CLOUDS ARE AT...TEMPERATURES
HAVE DROPPED LITTLE. CLOUDS ARE EXPECTED TO DECREASE BETWEEN 06Z
AND 09Z. HOWEVER BY THAT TIME THE WEST WINDS IN ADVANCE OF THE
NEXT SURFACE TROUGH START INCREASING.
BELIEVE THE BEST OPPORTUNITY FOR A CONTINUED DROP WILL BE RIGHT
NOW AND IN THE SOUTHERN AND WESTERN SECTIONS WHERE THE BEST
RADIATIONAL SETUP WILL OCCUR. DID LOWER TEMPERATURES A FEW DEGREES
ESPECIALLY IN THE ABOVE SPECIFIED AREAS BUT THAT IS PROBLEMATIC
DEPENDING ON HOW THE WIND/CLOUD SCENARIO EVOLVES. MOSGUIDE IS
CATCHING THE CLOUD COVER THE BEST AND MATCHES WELL WITH THE
EXPECTED LIFT AND USED THAT TO UPDATE THE CLOUD COVER THROUGH
TOMORROW MORNING.
FOR THE REST OF TONIGHT...USED THE LATEST RUC SINCE IT IS
DEPICTING THE CURRENT SITUATION VERY WELL RIGHT NOW. NEW NAM IS
ROLLING IN AT THIS TIME. THERE WAS SOME CONCERN EXPRESSED BY THE
DAY SHIFT ON NEEDING A WIND ADVISORY FOR TOMORROW. WAS EARLIER
LEANING TOWARD DOING THAT. HOWEVER...THE NEW NAM IS A LITTLE LESS
WINDY THAN THE PREVIOUS RUNS. PLUS MODELS OVERDID THE MIXING AND
WINDS YESTERDAY. PLUS CURRENT MODEL DATA IS NOT SHOWING A LOT OF
SUBSIDENCE DURING THE DAY TOMORROW WITH MOST OF THAT OCCURRING
VERY LATE TONIGHT. SO SOME DOUBT ABOUT THE NEEDED ADVISORY BUT
WILL BE CLOSE. SO ADJUSTED WINDS DOWN SLIGHTLY AND A LITTLE BELOW
ADVISORY CRITERIA. WILL LET NIGHT SHIFT LOOK AT OVERNIGHT DATA TO
ASSESS THE NEED FOR AN ADVISORY. ALSO ADJUSTED DEWPOINTS WITH
NOTHING CATCHING THAT WELL RIGHT NOW.
UPDATE ISSUED AT 439 PM MST SAT MAR 3 2012
FORECAST WAS UPDATED EARLIER DUE TO THE EARLY CANCELLATION OF THE
WIND ADVISORY AND RED FLAG WARNING.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 228 PM MST SAT MAR 3 2012
SKY COVER HAS INHIBITED HEATING AND MIXING TODAY. AM KEEPING THE
WIND ADVISORY INTACT THROUGH LATE AFTERNOON AS IT IS STILL POSSIBLE
SOME OF THE STRONGER WINDS ALOFT MAY MIX TO THE SURFACE WITH VIRGA
BEING OBSERVED AND AREAS OVER THE FAR WESTERN CWA CURRENTLY AT OR
NEAR CRITERIA.
EXPECT SKY COVER TO DECREASE OVERNIGHT AS WE LOSE DAYTIME HEATING
AND THE CU FIELD. ALSO EXPECT HIGH CLOUDS STREAMING THROUGH THE
NORTHWEST FLOW ALOFT TO BEGIN MOVING OFF TO THE EAST OVERNIGHT AND
SUNDAY AS THE UPPER RIDGE MOVES FROM THE FAR WESTERN UNITED STATES
INTO POSITION OVER THE INTER-MOUNTAIN WEST. EXPECT THE CENTRAL HIGH
PLAINS REGION TO REMAIN DRY WITH TEMPERATURES WARMING AS WE COME
UNDER A GREATER INFLUENCE OF THE UPPER RIDGE.
WINDS ARE EXPECTED TO DROP AROUND SUNSET...BUT WILL INCREASE AGAIN
AFTER MIDNIGHT. WINDS WILL BE A CONCERN ON SUNDAY AS THE STRONGEST
PRESSURE GRADIENT MOVES EASTWARD OVER THE FORECAST AREA. WITH
WARMER TEMPERATURES AND UNIDIRECTIONAL FLOW...EXPECT MORE OF THE
STRONGER WINDS TO MIX DOWN THAN THEY MAY BE TODAY....ESPECIALLY OVER
THE EASTERN/NORTHEASTERN HALF OF THE FORECAST AREA WHERE A WIND
ADVISORY MAY BE NEEDED. WILL NOT ISSUE ONE AT THIS POINT SINCE IT
HAS NOT BEEN COORDINATED WITH SURROUNDING OFFICES AND DO NOT WANT
ANY PUBLIC CONFUSION WITH THE ONE STILL IN EFFECT DURING THE
REMAINDER OF THE DAY TODAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 228 PM MST SAT MAR 3 2012
DRY CONDITIONS AND WARM TEMPERATURES ARE STILL EXPECTED MONDAY
AND TUESDAY WITH W/SW FLOW ALOFT AND A VERY DRY AIRMASS IN PLACE
OVER THE CENTRAL HIGH PLAINS. TEMPERATURES IN THE 70S ARE EXPECTED
BOTH DAYS...WITH TEMPS ON TUESDAY POSSIBLY REACHING THE MID/UPPER
70S IN THE SOUTH AND EAST. MAIN CONCERN WILL CONTINUE TO BE
POTENTIAL FOR RED FLAG CONDITIONS BOTH DAYS. RH VALUES CURRENTLY
FORECAST TO DROP BELOW 15 PERCENT BOTH DAYS...MAINLY ACROSS THE
WESTERN AND SOUTHERN PARTS OF THE CWA. GUSTY WINDS ARE EXPECTED
BOTH DAYS...HOWEVER THE STRONGEST WINDS ARE EXPECTED TO BE IN THE
EAST WHERE TIGHTER SURFACE GRADIENT WILL COMBINE WITH
UNIDIRECTIONAL FLOW ALOFT. THESE WINDS MAY NOT OVERLAP WITH LOW RH
FOR A LONG ENOUGH PERIOD OF TIME FOR RED FLAG TO BE MET.
A COLD FRONT WILL PASS OVER THE CWA TUESDAY NIGHT...COOLING TEMPS
TO NEAR SEASONAL NORMALS (UPPER 40S/LOW 50S) WEDNESDAY AND
THURSDAY. A SHORTWAVE TROUGH WILL PASS THROUGH THE PLAINS
WEDNESDAY AND WEDNESDAY NIGHT WHICH COULD BRING THE POTENTIAL FOR
RAIN WED AND RAIN/SNOW WED NIGHT. ECMWF ALONG WITH SUPPORT OF
ENSEMBLES CONTINUES TO SHOW A SPLIT IN THE UPPER PATTERN THAT
WOULD RESULT IN OUR CWA BEING MISSED. GFS HAS BEEN BACK AND FORTH
ON SHOWING A SIMILAR SPLIT OR AN OPEN WAVE...SO WAS NOT CONFIDENT
ENOUGH TO BUY INTO ITS WETTER SOLUTION. I KEPT PRECIP OUT OF
FORECAST FOR NOW. SHORTWAVE RIDGE IS EXPECTED TO BUILD BACK OVER
THE INTER- MOUNTAIN WEST TOWARDS THE END OF NEXT WEEK...WHICH
SHOULD BRING ABOVE NORMAL TEMPS IN THE UPPER 50S/NEAR 60 FRIDAY
AND SATURDAY.
OVERALL NOT A LOT OF HOPE FOR MEANINGFUL PRECIP ON THE HORIZON
WITH EITHER RIDGING OR WESTERLY FLOW ALOFT THROUGH THE EXTENDED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 439 PM MST SAT MAR 3 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. CURRENT CLOUD COVER
WILL DECREASE DUE TO LOSS OF HEATING AND MID/UPPER LIFT MOVING
EAST. MAIN PROBLEM WILL BE THE WINDS. WINDS WILL DECREASE RAPIDLY
EARLY THIS EVENING...AND REMAIN LIGHT UNTIL AFTER 06Z WHEN THEY
WILL INCREASE AND BECOME GUSTY ONCE AGAIN DUE TO SUBSIDENCE BEHIND
NORTHERN STREAM WAVE AND ASSOCIATED SURFACE TROUGH. AFTER
SUNRISE...THESE WILL INCREASE IN STRENGTH AND CONTINUE UNTIL LATE
IN THE AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...LOCKHART
LONG TERM....DR
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
345 AM CST FRI MAR 2 2012
...UPDATED SYNOPSIS...SHORT TERM...AND LONG TERM DISCUSSIONS...
.SYNOPSIS...
ISSUED AT 345 AM CST FRI MAR 2 2012
02.00Z 300 HPA MAP ANALYSIS SHOWED A STRONG 140 KT MERIDIONAL JET FROM
BRITISH COLUMBIA INTO NW NEVADA. THIS JET WAS WRAPPING AROUND A SERIES
OF VORTMAXES AND ASSOCIATED SHORT WAVE TROUGHS IN THE MID LEVELS LOCATED
ACROSS THE ROCKIES. ANOTHER STRONG 125 KT JET WAS MOVING ACROSS OKLAHOMA.
VERY COLD AIR AT 500 HPA WAS NOTED ACROSS THE NORTHERN GREAT BASIN INTO
THE NORTHERN ROCKIES WITH -30S DEG C VALUES. AT 700 AND 850 HPA, COLD
AIR ADVECTION WAS NOTED ACROSS THE NORTHERN AND CENTRAL PLAINS BETWEEN
12Z AND 00Z RAOBS. AT THE SFC, A COLD FRONT WAS LOCATED ACROSS OKLAHOMA
WITH DEWPOINTS IN THE 60S DEG F SOUTH OF THIS BOUNDARY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 345 AM CST FRI MAR 2 2012
TODAY:
KDDC WSR-88D IS INDICATING RETURNED POWER FROM LIGHT SNOW SHOWERS EARLY
THIS MORNING. THIS IS AN IMMEDIATE NEAR TERM CONCERN. ONCE THESE SHOWERS
DISSIPATE, A QUIET WEATHER DAY IS EXPECTED ACROSS SOUTHWEST KANSAS.
THIS ACTIVITY IS ASSOCIATED WITH A 400 HPA PV ANOMALY ROTATING ACROSS
THE STATE AT THE BASE OF AN UPPER LEVEL SHORTWAVE TROUGH EJECTING ACROSS
THE NORTHERN PLAINS. TWO AREAS OF ENHANCED PETERSON FRONTOGENESIS IN
THE 850-650 HPA LAYER WILL WEAKEN/MOVE OUT OF THE AREA BY MID MORNING.
AS A RESULT, HAVE TAPER POPS TO THE SOUTHWEST THROUGH MORNING. HIGH
PRESSURE WILL BUILD ACROSS KANSAS. WE WILL SEE A SLIGHT DOWNSLOPE NNW
WIND WITH MIXING UP TO 700 HPA. EXPECTING MAXIMUM TEMPERATURES IN THE
UPPER 40S DEG F ACROSS WEST CENTRAL KANSAS AND LOW 50S DEG F ACROSS
SOUTH CENTRAL KANSAS. IN ADDITION, THE MID LEVELS AT 500 HPA WILL COOL
AS A COLD POOL (~-33 DEG C MOVES OVERHEAD) SO WE COULD SEE SOME CUMULUS
BUILDUPS TODAY.
TONIGHT:
TRANQUIL WEATHER IS EXPECTED THIS EVENING AS HIGH PRESSURE PREVAILS
ACROSS THE PLAINS. SKIES WILL CLEAR THROUGH EVENING AND A LIGHT NORTHWESTERLY
WIND IS EXPECTED THROUGH THE OVERNIGHT. NOT EXPECTING ANY PRECIPITATION
THIS EVENING IN ASSOCIATION WITH SUBSIDENCE BEHIND AN UPPER LEVEL TROUGH
AND HIGH PRESSURE AT THE SFC. OVERNIGHT LOWS ARE EXPECTED TO BE IN THE
20S DEG F.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 345 AM CST FRI MAR 2 2012
SATURDAY THROUGH SUNDAY NIGHT:
ONLY SUBTLE CHANGES WERE REQUIRED TO THE GRIDS AS THIS WILL BE A RELATIVELY
QUIET SENSIBLE WEATHER PERIOD. THE MAIN CHALLENGE WILL BE DEWPOINT/RH
FORECAST SATURDAY AS NORTHWESTERLY DOWNSLOPE CONDITIONS WILL ALLOW THE
LOWER TROPOSPHERE TO BECOME VERY DRY (DEWPOINT TEMPERATURES LIKELY IN
THE SINGLE DIGITS FAHRENHEIT). AS TEMPERATURES SATURDAY TOP OUT IN THE
48 TO 51 DEGREE RANGE IN THE WEST...AFTERNOON RH WILL FALL TO AT LEAST
THE UPPER TEENS IF NOT LOWER. WILL HAVE TO BE MINDFUL OF CRITICAL FIRE
WEATHER CONDITIONS DEVELOPING AS AFTERNOON MIXING WILL ALLOW NORTHWEST
WINDS TO PROBABLY REACH THE WIND CRITERIA (SUSTAINED/FREQUENT GUSTS
25 MPH). ON SUNDAY...NORTHWESTERLY DOWNSLOPE FLOW WILL CONTINUE...BUT
THE LOWER TROPOSPHERE WILL CONTINUE TO WARM WITH HIGHS WELL INTO THE
LOWER TO MID 60S FOR MOST AREAS OF THE DDC FORECAST AREA. THE MODELS
SHOW A MODEST IMPROVEMENT IN DEWPOINT TEMPERATURES, BUT THE WARMER
TEMPERATURES WILL COUNTER THIS AND ANOTHER DAY OF N EAR CRITICAL
FIRE WEATHER CONDITIONS WILL BE POSSIBLE.
MONDAY THROUGH THURSDAY:
THE BIG FORECAST CHALLENGE WILL BE MID-WEEK AS THE GLOBAL MODELS SUGGEST
AN ANTICYCLONIC WAVE-BREAKING LOW DEVELOPING OVER THE INTERMOUNTAIN
WEST MOVING INTO THE SOUTHERN ROCKIES BY WEDNESDAY NIGHT/THURSDAY.
AHEAD OF THIS PATTERN CHANGE...VERY WARM AND QUIET SENSIBLE WEATHER
IS EXPECTED MONDAY AND TUESDAY. A TROUGH WITHIN THE ACTIVE NORTHERN
STREAM JET IS EXPECTED TO TRAVEL EAST ACROSS THE NORTH CENTRAL CONUS
WHICH WILL BRING A FAIRLY STRONG COLD FRONT SOUTH WEDNESDAY. WEDNESDAY
FORECAST IS VERY CHALLENGING ESPECIALLY REGARDING DAYTIME TEMPERATURES.
THE STRONG COLD FRONT WILL LIKELY MOVE SOUTH THROUGH SOUTHWEST KANSAS
DURING THE DAY RESULTING IN FALLING AFTERNOON TEMPERATURES IN THE NORTH.
MOISTURE RETURN AHEAD OF THE FRONT WEDNESDAY IS SHOWN IN THE GFS AND
ECMWF MODELS WITH THE PROBABILITY OF PRECIPITATION INCREASING BY LATE
IN THE DAY WEDNESDAY ALONG THIS FRONT. PRECIPITATION CHANCES THEN INCREASE
WEDNESDAY NIGHT AS THE UPPER LOW OVER ARIZONA BEGINS TO MOVE EAST INTO
NEW MEXICO. AT THIS TIME...THE WX GRIDS WILL REFLECT SHOWERS AND ISOLATED
THUNDER IN THE SOUTH CENTRAL KANSAS COUNTIES WITH RAIN IN THE CENTRAL
KANSAS COUNTIES NORTH OF THE FRONT. THIS IS THINKING RIGHT NOW...HOWEVER
THIS FORECAST IS SUBJECT TO CHANGE (AND IT MOST LIKELY WILL) AS WE GET
CLOSER TO THIS POTENTIAL PRECIPITATION EVENT TOWARD MID-NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1102 PM CST THU MAR 1 2012
LATEST HRRR/NAM SHOW THAT THIS PRECIP EVENT PROBABLY WILL HAVE SIG IMPACTS
TO AVIATION. FRCST COMP REFLECTIVITY FROM THE HRRR IS NOT THAT IMPRESSIVE
NOR IS QPF AMOUNTS. HAVE -SN FOR KGCK/KHYS AS THESE TERMINALS WILL BE
CLOSER TO THE 700 HPA BAROCLINIC ZONE/TROUGH AND WITHIN A ZONE OF HIGHER
OMEGA/ISEN LIFT. KHYS MIGHT SEE A REDUCTION TO MVFR CIGS THROUGH MORNING,
HOWEVER, CIGS WILL GENERALLY REMAIN VFR WHICH IS FORECAST BY THE HRRR.
VERY COLD AIR 500 HPA AROUND -33DEGC WILL SPREAD OVER W KS IN ASSOCIATION
WITH AN UL TROUGH SO CUMULUS BUILDUPS ARE POSSIBLE LATER TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 51 23 51 30 / 10 0 10 0
GCK 49 22 50 29 / 20 0 10 0
EHA 45 22 50 29 / 30 0 10 0
LBL 50 21 51 29 / 20 0 10 0
HYS 50 24 50 30 / 10 0 10 0
P28 54 28 53 32 / 10 0 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....UMSCHEID
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1052 PM MST THU MAR 1 2012
.UPDATE...
ISSUED AT 644 PM MST THU MAR 1 2012
BAND OF LIGHT SNOW HAS DEVELOPED ACROSS SOUTHERN PORTIONS OF KIT
CARSON COUNTY COLORADO STRETCHING EASTWARD THEN NORTHEASTWARD INTO
NORTHWEST KANSAS. KITR HAD A BRIEF PERIOD OF 3/4 MILE VISIBILITY
IN LIGHT SNOW WITH THAT PORTION OF THE BAND NOW SHIFTING EASTWARD
INTO SOUTHWEST PORTIONS OF SHERMAN COUNTY. ANOTHER AREA OF
ENHANCED REFLECTIVITY RESIDES OVER SOUTHWEST KIT CARSON COUNTY AND
CONTINUES TO SHIFT EASTWARD WITH TIME. PRIMARY CHANGES WERE TO
SPEED UP ONSET OF PRECIP ACROSS NORTHWEST KANSAS. ALSO MADE
SIGNIFICANT ADJUSTMENTS TO THE DEW POINT GRIDS AS TOP DOWN
MOISTENING HAS RESULTED IN DEW POINTS JUMPING INTO THE LOWER TO
MIDDLE 20S WHERE PRECIP IS FALLING.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 200 PM MST THU MAR 1 2012
A COLD FRONT THAT PASSED OVER THE CWA EARLY THIS MORNING IS NOW
ACROSS SOUTHWEST KANSAS AND SOUTHEAST COLORADO. EARLY AFTERNOON WV
IMAGERY AND RUC H5 ANALYSIS SHOW A BROAD TROUGH ACROSS THE WESTERN
US. A STRENGTHENING SHORTWAVE TROUGHS IS CURRENTLY MOVING INTO
WESTERN COLORADO.
TONIGHT THROUGH FRIDAY...SHORTWAVE TROUGH WILL MOVE OUT OF COLORADO
INTO WESTERN KANSAS. MOISTURE/LIFT WILL INCREASE FROM THE WET TO THE
EAST THIS EVENING AHEAD OF THIS FEATURE...WITH BEST LIFT/MOISTURE IN
THE 03-09Z TIMEFRAME. RAIN WILL QUICKLY TRANSITION TO SNOW IN THE
WEST THIS EVENING...WITH A RAIN/SNOW MIX IN THE EAST MOST OF THE
NIGHT. BY SUNRISE MOST LOCATIONS SHOULD SEE RAIN COMPLETELY
TRANSITION TO SNOW. GUIDANCE HAS TRENDED FURTHER SOUTH AND WEST ON
PLACEMENT OF HIGHEST SNOWFALL AMOUNTS...WHICH MAKES SENSE
CONSIDERING THE LOCATION OF SURFACE BAROCLINIC ZONE. WITH THIS IS
MIND...I INCREASED POPS ACROSS THE SOUTHWEST...AND DECREASED POPS IN
THE NORTHEAST. CONSIDERING THE LIMITED MOISTURE ADVECTION...AND
QUICK NATURE OF THIS SYSTEM...SNOWFALL AMOUNTS SHOULD REMAIN LIGHT.
RIGHT NOW HIGHEST AMOUNTS SHOULD BE LIMITED TO EASTERN COLORADO
WHERE 1-2 INCHES IS EXPECTED.
WITH LARGE SCALE SUBSIDENCE BUILDING BACK OVER THE CWA FRIDAY
MORNING FROM THE NORTH...PRECIPITATION SHOULD TAPER OFF QUICKLY FROM
THE NORTH TO THE SOUTH BY MID FRIDAY MORNING OVER ALL BUT THE
EXTREME SOUTHWEST PARTS OF THE CWA. DRY CONDITIONS ARE THEN EXPECTED
THROUGH FRIDAY AFTERNOON ACROSS ALL OF THE CWA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 200 PM MST THU MAR 1 2012
MAIN WEATHER STORY FOR THE LONG TERM IS A WARMING TREND AS LARGE
UPPER RIDGE ALBEIT SOMEWHAT FLAT DEVELOPS OVER THE AREA. HIGH
TEMPERATURE SATURDAY IN THE 40S WILL WARM INTO THE 50S AND LOW 60S
SUNDAY. EVEN WARMER ON MONDAY WITH MID TO UPPER 60S AND MID 60S TO
LOW 70S TUESDAY.
TIMING DIFFERENCES SHOW UP WEDNESDAY AND THURSDAY AS THE WEST
COAST UPPER TROUGH MOVES TOWARD OR ACROSS THE AREA...IMPACTING THE
TEMPERATURE FORECAST. LOOKS TO REMAIN ABOVE NORMAL BOTH DAYS WITH
HIGHS IN THE 50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1047 PM MST THU MAR 1 2012
BULK OF PRECIP NOW RESIDE SOUTHWEST OF KGLD AND ANTICIPATE THIS
TREND WILL CONTINUE. SHOULD SEE VFR CONDITIONS AT BOTH KGLD AND
KMCK THROUGH THE EFFECTIVE PERIOD. WINDS WILL BE VARIABLE
OVERNIGHT BEFORE BECOMING ESTABLISHED FROM THE NORTHWEST DURING
THE DAY FRIDAY. COULD SEE A FEW GUSTS APPROACHING 30KTS BEFORE
SUBSIDING AROUND SUNSET. BKN-OVC MID-LEVEL CLOUD DECK WILL SLOWLY
ERODE ON FRIDAY.
&&
.FIRE WEATHER...
ISSUED AT 200 PM MST THU MAR 1 2012
CRITICAL FIRE WEATHER CONDITIONS REMAIN POSSIBLE ALONG AND SOUTH
OF INTERSTATE 70 SATURDAY AS NORTHWEST WINDS OF 15 TO 25 MPH WITH
HIGHER GUSTS COMBINE WITH AFTERNOON HUMIDITY AS LOW AS 20 PERCENT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...FOLTZ
SHORT TERM...DR
LONG TERM....007
AVIATION...FOLTZ
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1118 PM CST THU MAR 1 2012
...UPDATE TO AVIATION FOR 06Z TAFS...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 125 PM CST THU MAR 1 2012
THE MAIN FORECAST FOCUS WILL BE ON THE CHANCE FOR PRECIP LATE
TONIGHT.
SHORT RANGE MODELS INDICATE THE UPPER LEVEL SHORTWAVE IN THE WESTERN
NORTHERN PLAINS TRACKING SLOWLY EAST INTO THE DAKOTAS TONIGHT THEN
EDGING INTO MINNESOTA FRIDAY. MEANWHILE, THE SECONDARY UPPER LEVEL
SHORTWAVE WILL CONTINUE TO DROP SOUTHEAST TONIGHT MOVING INTO THE
FOUR CORNERS REGION BY EARLY FRIDAY MORNING. THESE TWO FEATURES WILL
BRING THE POSSIBILITY FOR PRECIP ACROSS PORTIONS OF THE NORTHERN
PLAINS AND FROM ACROSS THE ROCKIES INTO THE WESTERN HIGH PLAINS
TONIGHT INTO EARLY FRIDAY. HOWEVER, NO PRECIP IS EXPECTED ACROSS
WESTERN KANSAS EARLY THIS EVENING WITH THE INITIAL PASSING OF THE
COLD FRONT ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS NOT TO
MENTION THE WEAK DYNAMIC SUPPORT ALOFT AND STRONG LACK OF LOW
LEVEL MOISTURE. HOWEVER, THERE IS A SLIGHT CHANCE FOR PRECIP LATE
TONIGHT INTO EARLY FRIDAY ACROSS EXTREME WESTERN PORTIONS OF
WESTERN KANSAS AS THE SECONDARY UPPER LEVEL SHORTWAVE DIPS
SOUTHEAST INTO THE FOUR CORNERS REGION. THE NAM, GFS, AND UKMET
SHOW A SERIES OF H5 VORT MAXES EJECTING NORTHEAST OUT OF THE
TROUGH AXIS ACROSS THE PANHANDLES OF TEXAS AND OKLAHOMA INTO
SOUTHWEST KANSAS TONIGHT JUST AS A BAND OF H7 FRONTOGENESIS
DEVELOPS BEHIND THE FRONT ACROSS SOUTHEAST COLORADO INTO WESTERN
KANSAS. AS A RESULT, LIGHT RAIN OR SNOW WILL BE POSSIBLE FROM
ACROSS EASTERN COLORADO AND POTENTIALLY JUST INTO EXTREME WESTERN
KANSAS LATE TONIGHT. HOWEVER, LITTLE ACCUMULATION IS EXPECTED, IF
ANY, WITH ONLY MODEST MOISTURE AVAILABLE IN THE MID AND UPPER
LEVELS AS INDICATED BY LOW QPF VALUES IN ALL MODELS.
TEMPERATURES ARE EXPECTED TO BE NEAR SEASONAL TONIGHT AS MUCH COLDER
AIR SURGES SOUTH INTO WESTERN KANSAS TONIGHT IN WAKE OF A COLD
FRONTAL PASSAGE LATE THIS AFTERNOON AND EVENING. COLD AIR ADVECTION
WILL BRING H85 TEMPERATURES OF AROUND TO JUST BELOW 0C DOWN INTO
SOUTHWEST AND SOUTH CENTRAL KANSAS BY EARLY FRIDAY MORNING. ALTHOUGH
INCREASING CLOUDS DUE TO THE APPROACHING STORM SYSTEM COULD HELP
KEEP TEMPERATURES FROM FALLING AS MUCH. LOOK FOR LOWS DOWN INTO THE
20S(F) TO LOW 30S(F) TONIGHT. FOR FRIDAY, A STRENGTHENING SURFACE
LOW ACROSS KANSAS TONIGHT WILL KICK OFF TO THE EAST FRIDAY JUST AS
SURFACE HIGH PRESSURE BEGINS TO BUILD IN ACROSS THE NORTHERN ROCKIES.
THIS WILL CONTINUE TO INFLUENCE A LOW LEVEL NORTHERLY FLOW INTO
WESTERN KANSAS THROUGH THE DAY HELPING TO KEEP H85 TEMPERATURES OF
AROUND 0C IN PLACE. LINGERING CLOUDS MAY TEMPER TEMPERATURES A BIT
BUT SO EXPECT HIGHS UP INTO THE 40S(F) WITH A FEW LOW 50S(F)
POSSIBLE IN SOME LOCATIONS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 216 PM CST THU MAR 1 2012
AN UPPER LEVEL LONG WAVE TROUGH WILL BE FOUND ACROSS THE EASTERN TWO
THIRDS OF THE UNITED STATES AS THE LONG TERM PERIOD BEGINS. THIS
UPPER LEVEL TROUGH WILL MOVE TO THE EAST FRIDAY NIGHT THROUGH MONDAY
AS AN UPPER LEVEL RIDGE MOVES INTO THE WESTERN UNITED STATES. THIS
WILL PUT WESTERN KANSAS UNDER NORTHWEST FLOW ALOFT SATURDAY THROUGH
MONDAY. HIGH PRESSURE WILL BE THE DOMINATE FEATURE AT THE SURFACE
AND PARTLY CLOUDY SKIES AND DRY CONDITIONS ARE EXPECTED ACROSS
WESTERN KANSAS DURING THIS TIME FRAME. WINDS IN THE LOWER LEVELS OF
THE ATMOSPHERE WILL BE FROM THE NORTHWEST SATURDAY THROUGH MONDAY
AND WILL TRANSLATE TO A GENERAL WARMING TREND DUE TO THE DOWNSLOPE
NATURE OF THE WINDS. HIGHS WILL START OUT AROUND 50 DEGREES ON
SATURDAY AFTERNOON THEN TO THE UPPER 60S BY MONDAY AFTERNOON. LOWS
WILL START OUT IN THE MID 20S SATURDAY MORNING AND IN THE MID 30S BY
MONDAY MORNING.
MODELS ARE THEN SUGGESTING AN UPPER LEVEL SHORTWAVE TO MOVE INTO THE
WEST COAST MONDAY INTO TUESDAY, THEN INTO THE INTERMOUNTAIN WEST ON
WEDNESDAY. THE UPPER LEVEL RIDGE WILL SHIFT EASTWARD TOWARDS THE MID
MISSISSIPPI VALLEY AS THIS SYSTEM APPROACHES PLACING OUT AREA UNDER
SOUTHWEST FLOW ALOFT. THIS SYSTEM WILL ALSO CAUSE LEE TROUGHING TO
DEVELOP AT THE SURFACE ACROSS EASTERN COLORADO SHIFTING WINDS TO THE
SOUTH TO SOUTHWEST. A SURFACE HIGH WILL BE POSITIONED ACROSS THE
SOUTHEAST UNITED STATES AND HELP PUSH GULF MOISTURE NORTH INTO THE
CENTRAL PLAINS. CLOUDS ARE FORECAST TO INCREASE WEDNESDAY AS THE
AFOREMENTIONED STORM SYSTEM APPROACHES. EXTENDED MODELS ARE
SUGGESTING THAT THERE COULD BE ENOUGH MOISTURE AND LIFT ACROSS THE
AREA TO PRODUCE PRECIPITATION WEDNESDAY NIGHT BUT HAVE ONLY PLACED A
SLIGHT CHANCE OF POPS IN THE GRIDS TO REFLECT THIS. A SLIGHT COOLING
TREND IS ANTICIPATED MONDAY THROUGH WEDNESDAY AS LOWS ARE FORECAST
TO BE IN THE LOWER 40S THURSDAY AND FRIDAY MORNING WITH UPPER 30S BY
THURSDAY MORNING. HIGHS WILL BE IN THE LOWER 70S TUESDAY THEN IN THE
60S WEDNESDAY AND THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1102 PM CST THU MAR 1 2012
LATEST HRRR/NAM SHOW THAT THIS PRECIP EVENT PROBABLY WILL HAVE SIG IMPACTS
TO AVIATION. FRCST COMP REFLECTIVITY FROM THE HRRR IS NOT THAT IMPRESSIVE
NOR IS QPF AMOUNTS. HAVE -SN FOR KGCK/KHYS AS THESE TERMINALS WILL BE
CLOSER TO THE 700 HPA BAROCLINIC ZONE/TROUGH AND WITHIN A ZONE OF HIGHER
OMEGA/ISEN LIFT. KHYS MIGHT SEE A REDUCTION TO MVFR CIGS THROUGH MORNING,
HOWEVER, CIGS WILL GENERALLY REMAIN VFR WHICH IS FORECAST BY THE HRRR.
VERY COLD AIR 500 HPA AROUND -33DEGC WILL SPREAD OVER W KS IN ASSOCIATION
WITH AN UL TROUGH SO CUMULUS BUILDUPS ARE POSSIBLE LATER TODAY.
&&
.FIRE WEATHER...
ISSUED AT 345 AM CST THU MAR 1 2012
ADIABATIC COMPRESSIONAL WARMING VIA MIXING TO NEAR 550 HPA AND DOWNSLOPE
WESTERLY WINDS AHEAD OF A COLD FRONT WILL LEAD TO CRITICAL FIRE WEATHER
CONDITIONS TODAY ACROSS FAR SW KANSAS. AS A RESULT, HAVE ISSUED AN RFW
FOR EXTREME SOUTHWEST KANSAS TODAY NEAR THE COLORADO AND OKLAHOMA STATE
BORDERS. SEE TOPRFWDDC FOR SPECIFIC DETAILS ON THIS HAZARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 28 50 25 51 / 20 20 10 10
GCK 27 45 23 50 / 30 20 10 10
EHA 27 43 22 50 / 20 20 10 10
LBL 27 48 24 51 / 10 20 10 10
HYS 28 47 24 50 / 30 20 10 10
P28 33 53 29 53 / 10 10 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJOHNSON
SHORT TERM...JJOHNSON
LONG TERM....HOVORKA 42
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS JACKSON KY
129 PM EST FRI MAR 2 2012
.UPDATE...
ISSUED AT 129 PM EST FRI MAR 2 2012
OUTSIDE OF THE EARLY SEVERE WEATHER ACROSS OUR SOUTHEAST AREAS...IT
NOW LOOKS LIKE THE AREA WILL BE LOCATED SOLIDLY IN THE WARM SECTOR
THROUGH THIS EVENING. HAVE REMOVED POPS FOR MOST AREAS OVER THE NEXT
SEVERAL HOURS...UNTIL ADDITIONAL DEVELOPMENT SPREADS INTO THE AREA
LATER THIS EVENING. WITH THE FAVORABLE CONDITIONS IN PLACE...SPC HAS
ISSUED A TORNADO WARNING FOR OUR FAR WESTERN AND NORTHERN COUNTIES
UNTIL 9 PM. IT APPEARS THE THREAT WILL HOLD OFF UNTIL THE TAIL END OF
THE WATCH...LIKELY NOT REACHING OUR AREA UNTIL AT LEAST 5 OR 6 PM.
ALL IN ALL...FORECAST LOOKS IN GOOD SHAPE.
UPDATE ISSUED AT 1234 PM EST FRI MAR 2 2012
DRY SLOT IS NOT NOSING INTO OUR SOUTHWEST COUNTIES...ENDING
PRECIPITATION THERE TEMPORARILY. THE SHOWERS AND STORMS SHOULD
CONTINUE TO DEPART TO THE NORTH AND EAST EARLY THIS
AFTERNOON...LEAVING MOST OF EASTERN KENTUCKY DRY FROM MID TO LATE
AFTERNOON. THIS WILL ALLOW TEMPERATURES TO WARM INTO THE MID 70S WITH
SOME BROKEN CIGS SPREADING ACROSS THE AREA. WITH DECENT MIXING
POTENTIAL...WE SHOULD SEE STRONG WINDS MIXING DOWN WITH SOME GUSTS UP
TO 40 MPH LIKELY. CANNOT RULE OUT AN ISOLATED STORM THIS
AFTERNOON...BUT THE MORE LIKELY SCENARIO IS ACTIVITY ARRIVING AHEAD
OF THE FRONTAL BOUNDARY LATER THIS EVENING.
MEANWHILE...SHOWERS AND STORMS ARE ALREADY DEVELOPING ALONG AND JUST
AHEAD OF THE FRONTAL BOUNDARY ACROSS MISSOURI AND ILLINOIS. BASED ON
LATEST HRRR...THIS ACTIVITY SHOULD PUSH INTO OUR BLUEGRASS COUNTIES
TOWARDS 5 OR 6 PM...THEN ACROSS THE REST OF EASTERN KENTUCKY THROUGH
10 PM. EARLY ON...STILL CONCERNED WITH DISCRETE SUPERCELLS...CAPABLE
OF DAMAGING WINDS...LARGE HAIL...AND A TORNADO. AS THE FRONT PUSHES
INTO THE REGION...A SQUALL LINE WILL LIKELY EVOLVE...WITH THE MAIN
THREAT STRAIGHT LINE DAMAGING WINDS. HOWEVER...A SPIN UP TORNADO
ALONG THE LINE IS POSSIBLE STILL. WITH THE FAST MOVEMENT OF
STORMS...THE SEVERE THREAT MAY BE OVER FOR MOST OF THE AREA BY
MIDNIGHT...WITH JUST SOME LEFT OVER RAIN PUSHING ACROSS OUR EASTERN
COUNTIES. HAVE LOWERED TEMPERATURES BEHIND THE FRONT TONIGHT...WITH
DECENT CLEARING SPREADING INTO THE AREA.
UPDATE ISSUED AT 1129 AM EST FRI MAR 2 2012
WIDESPREAD SHOWERS AND STORMS CONTINUE TO PROGRESS NORTHWARD ACROSS
THE CWA THIS MORNING...BUT A DISTINCT BACK EDGE AND DRY SLOT...BEHIND
THE ADVANCING WARM FRONT IS NOTED BACK ACROSS CENTRAL TENNESSEE.
USING THE TIMING TOOL...IT LOOKS LIKE THE ONGOING ACTIVITY SHOULD
PUSH NORTH AND EAST OF THE AREA BY 19Z...PROVIDING A DECENT BREAK FOR
MOST AREAS THIS AFTERNOON. HRRR IS HANDLING THE SITUATION FAIRLY
WELL. IT SHOWS SOME DISTINCT SUPERCELLS DEVELOPING OUT IN THE
BLUEGRASS BETWEEN 21 AND 22Z. THESE MAY IMPACT OUR NORTHEAST BLUEGRASS
COUNTIES AROUND THIS TIME. THESE STORMS WOULD OBVIOUSLY HAVE THE
POTENTIAL FOR LARGE HAIL...DAMAGING WINDS...AND TORNADOES. THESE
STORMS SHOULD DEVELOP OUT AHEAD OF THE ADVANCING COLD FRONT...WITH A
SQUALL LINE DEVELOPING ALONG THE ACTUAL FRONTAL BOUNDARY. THE MAIN
THREAT WITH THE SQUALL LINE WILL BE DAMAGING WINDS...BUT A BRIEF SPIN
UP ALONG THIS LINE IS POSSIBLE...PRODUCING A TORNADO. THE FRONTAL
BOUNDARY SHOULD HOLD OFF TO OUR WEST UNTIL AT LEAST 00Z. SO THE MAIN
THREAT PRIOR TO THAT TIME WILL BE THE DISCRETE SUPERCELLS IN THE WARM
SECTOR. WARM AND MUGGY CONDITIONS WILL DEVELOP HEADING INTO THIS
AFTERNOON WITH DEWPOINTS CLIMBING UP TO AROUND 60 WITH TEMPERATURES
AROUND 70. CERTAINLY JUICY AIR FOR THIS TIME OF YEAR. LAKE WIND
ADVISORY WILL CONTINUE AS ADVERTISED. FLASH FLOOD THREAT ALSO APPEARS
A BIT ENHANCED WITH EARLY DAY RAINFALL ADDING TO THE ALREADY SOAKED
GROUND AND BANK FULL CREEKS.
UPDATE ISSUED AT 837 AM EST FRI MAR 2 2012
SHOWERS AND THUNDERSTORMS HAVE BECOME MORE WIDESPREAD ACROSS THE AREA
OVER THE PAST HOUR. THUS...HAVE BROUGHT IN SOME HIGHER CATEGORICAL
POPS THROUGH THIS MORNING. ANOTHER BAND OF SHOWERS AND STORMS IS
KNOCKING AT OUR DOORSTEP...JUST NOW PUSHING INTO AREAS AROUND
MONTICELLO. AFTER THE MORNING CONVECTION...STILL LOOKING LIKE A
POTENTIAL BREAK BY MID AFTERNOON...BEFORE THE MAIN LINE OF CONVECTION
ARRIVES WITH THE FRONT BETWEEN 6 AND 9 PM. HAD SOME REPORTS OF
SUB-SEVERE HAIL THIS MORNING (HAIL LESS THAN AN INCH IN
DIAMETER)...BUT NOTHING SEVERE AS OF YET. MADE SOME TWEAKS TO
TEMPERATURES AND DEWPOINTS AS TEMPERATURES START TO WARM FROM SOUTH
TO NORTH AS THE FRONT PROGRESSES NORTHWARD.
UPDATE ISSUED AT 705 AM EST FRI MAR 2 2012
THE FORECAST IN GENERAL REMAINS ON TARGET...THOUGH CONVECTION UP UNTIL
THIS POINT HAS NOT BEEN ALL THAT WIDESPREAD. HOWEVER...ADDITIONAL
STRONG TO POSSIBLY SEVERE CONVECTION CONTINUES TO GET GOING TO OUR
SW IN NORTHERN MIDDLE TN AND SOME OF THIS ACTIVITY SHOULD LIFT NORTH
INTO THE REGION THROUGH MID TO LATE MORNING. ACTIVITY THIS MORNING
IS EXPECTED TO BE LARGELY ELEVATED AND EITHER WITH ONGOING CONVECTION
APPROACHING FROM CENTRAL KY AND THE CONVECTION APPROACHING FROM
MIDDLE TN WILL HAVE THE POTENTIAL TO PRODUCE HAIL...AND PERHAPS SOME
STRONGER WIND GUSTS.
ONCE THE WARM FRONT PASSES DURING THE MID AFTERNOON...THERE IS NOT A
LOT OF CONVECTIVE TRIGGERS...BUT ANY OUTFLOWS OR CONVECTION UPSTREAM
THAT MOVES IN OR ANY BREAKS IN THE CLOUDS COULD BE THE FOCUS FOR
INITIATION. OTHER THAN THE QUESTION OF A TRIGGER DURING MID AFTERNOON
AND SOME HINT OF MID LEVEL CAPPING IN THE FORECAST SOUNDINGS...IF
ANYTHING WERE TO GET GOING IT COULD BECOME SEVERE AS SHEAR WILL BE
AMPLE. IF THIS WERE TO BE IN SUPERCELL FORM...DAMAGING WINDS...LARGE
HAIL...AN EVEN A TORNADO WOULD BE POSSIBLE. IT STILL APPEARS THAT THE
MOST ORGANIZED SEVERE CONVECTION SHOULD OCCUR DURING THE LATE
AFTERNOON INTO THE EVENING HOURS.
HOURLY GRIDS WERE FRESHENED UP BASED ON THE LATEST TRENDS...BUT THE
PREVIOUS ZFP WAS STILL HANDLING THE SITUATION AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 430 AM EST FRI MAR 2 2012
SFC LOW PRESSURE OVER NE OKLAHOMA CONTINUES TO DEVELOP THIS MORNING
WITH A SFC WARM FRONT EXTENDING EAST INTO THE TN VALLEY REGION. AT
PRESENT IT IS ABOUT 2 MB STRONGER THAN THE 6Z NAM RUNS AND SLIGHTLY
STRONGER THAN MOST OF THE 0Z MODEL RUNS. THIS SYSTEM IS PROGGED TO
FURTHER DEEPEN AS IT TRACKS INTO THE GREAT LAKES THIS EVENING...WITH
THE MOST RAPID DEEPENING OCCURRING BETWEEN 18Z AND 0Z TONIGHT. THIS
SYSTEM WILL SEND A STRONG COLD FRONT INTO THE COMMONWEALTH...WITH THE
COLD FRONT REACHING THE JKL CWA DURING THE EVENING. THE COLD FRONT
SHOULD EXIT INTO VA EARLY ON AT AM.
DESPITE RELATIVELY CLOUD FREE CONDITIONS AT PRESENT WITH SOME VALLEY
LOCATIONS AT PRESENT IN THE 30S...A RATHER DRAMATIC RISE IN TEMPS AND
DEWPOINTS IS ANTICIPATED TODAY AS THE WARM FRONT LIFTS INTO THE
REGION FROM THE SOUTH AND WEST...MOVING NORTH AND EAST OF THE JKL CWA
BY EARLY TO MID AFTERNOON. DEWPOINTS ACROSS THE CWA ARE CURRENTLY IN
THE UPPER 20S AND 30S...BUT JUST SOUTH OF THE AREA DEWPOINTS IN THE
MID 40S ARE PRESENT ACROSS NORTHERN MIDDLE TN...THE 50S TO THE SOUTH
OF THAT AREA MIDDLE AND EAST TN AND THEN FURTHER SOUTH IN MS AND
AL...DEWPOINTS ARE IN THE LOWER 60S.
MODELS ALL PROG A RAPID INCREASE IN MOISTURE THIS MORNING AS THE WARM
FRONT MOVES INTO AND ACROSS THE AREA...AS HAS BEEN OCCURRING TO OUR SOUTH
AND WEST OVERNIGHT. AN AREA OF SHOWERS AND THUNDERSTORMS CONTINUES
TO DEVELOP FROM WEST CENTRAL KY SE INTO THE CUMBERLAND PLATEAU OF
MIDDLE TN. THIS CONVECTION SHOULD CONTINUE TO DEVELOP EARLY THIS
MORNING AND BECOME MORE WIDESPREAD AS MOISTURE TRANSPORT INCREASES AS
THE LOW LEVEL JET INCREASES. A ROUND OF SHOWERS AND AT LEAST SCATTERED
THUNDERSTORMS SHOULD OCCUR THIS MORNING. INSTABILITY IS PROGGED TO BE
RATHER LIMITED AND THIS CONVECTION ELEVATED...BUT THE STRONGEST
STORMS COULD PRODUCE SOME SMALL HAIL. WARM AND MOIST ADVECTION WILL
CONTINUE INTO THE AFTERNOON AS THE SFC LOW TRACKS BY TO OUR WEST. MID
LEVEL WARMING IN THE WARM SECTOR WILL LIKELY LEAD TO A LULL IN
PRECIPITATION CHANCES SPREADING FROM SOUTHWEST TO NORTHEAST IN THE
AFTERNOON. WITH THE SYSTEM ALREADY A BIT STRONGER THAN CURRENTLY
FORECAST BY THE MODELS OPTED TO GO TOWARD THE WARMER END OF GUIDANCE
FOR MAX AND WINDS THIS AFTERNOON. SINCE CONVECTION WILL BE LARGELY
ISOLATED TO SCATTERED IN THE AFTERNOON AND STRONG WINDS FIELDS ARE
PROGGED ALOFT...GUSTS OF 35 TO 40 MPH MAY OCCUR OUTSIDE OF SHOWER AND
THUNDERSTORM ACTIVITY. WITH THIS IN MIND WENT WITH A LAKE WIND
ADVISORY FROM NOON UNTIL 7 PM TODAY. ANY CONVECTION BY MID TO LATE
AFTERNOON WOULD HAVE THE POTENTIAL TO BE IN THE FORM OF CLUSTERS OR
SUPERCELLS DUE TO STRONG WIND FIELDS ALOFT AND AMPLE SHEAR.
INSTABILITY IN THE AFTERNOON DOES APPEAR TO BE SOMEWHAT LIMITED
THOUGH AND SOME MID LEVEL CAPPING MAY BE PRESENT WITH NOT MUCH OF A
TRIGGER.
THE HIGHEST THREAT FOR SEVERE THUNDERSTORMS...A MODERATE RISK IN THE
DAY 1 SPC OUTLOOK APPEARS TO BE FROM LATE AFTERNOON OR EARLY EVENING
AND CONTINUING INTO THE EVENING IN ADVANCE OF AND POSSIBLY ALONG THE
SFC COLD FRONT. HOWEVER...GIVEN THE STRENGTH OF THE DEVELOPING SYSTEM
AND WIND FIELDS ALOFT...ANY STRONGER STORM DURING THE DAY COULD ALSO
PRODUCE DAMAGING WINDS...WITH ANY SUPERCELLS THAT DEVELOP HAVING A
LARGE HAIL AND ISOLATED TORNADO THREAT AS THE LOWER LEVELS EVENTUALLY
WILL BE MORE SATURATED. SUPERCELLS OR STORM CLUSTERS ONGOING LATE IN
THE AFTERNOON OVER CENTRAL AND PERHAPS INTO EASTERN KY SHOULD EVOLVE
INTO A QLCS TYPE SYSTEM DURING THE EVENING AS THE FRONT APPROACHES
AND RACE ACROSS THE CWA. THIS STORMS WOULD ALSO HAVE THE POTENTIAL TO
PRODUCE DAMAGING WINDS...LARGE HAIL...LOCALLY HEAVY RAIN AND ISOLATED
POSSIBLY STRONG TORNADOES. THE PERIOD OF THREAT FOR THE LARGEST HAIL
MAY BE FROM VERY LATE IN THE AFTERNOON THROUGH EARLY IN THE EVENING
AS CONSIDERABLE MID LEVEL DRY AIR IS PROGGED...LEADING TO LOW WBZ
HEIGHTS NEAR 8KFT LATE AFTERNOON AND EARLY IN THE EVENING. ANY
ROTATING CELLS WOULD HAVE MORE VIGOROUS UPDRAFTS HIS PERIOD AND WOULD
BRING A LARGE HAIL THREAT.
WITH THE FRONT AT LEAST BRIEFLY BECOMING PARALLEL TO THE UPPER LEVEL
FLOW...SOME TRAINING OF CONVECTION MAY OCCUR FROM LATE THIS AFTERNOON
THROUGH EARLY THIS EVENING ON TOP OF ALREADY WET GROUND FROM RECENT IN
MAY PLACES HEAVY PRECIPITATION. ANY TRAINING WOULD BRING A THREAT FOR
FLASH FLOODING. MODELS OVERALL HAVE TRENDED BACK ON THE QPF...BUT
LOCALLY HIGHER AMOUNTS ARE VERY POSSIBLE WITH THE STRONGER CELLS AND
IN ANY TRAINING. OPTED TO CHANGE THE START TIME OF THE FLASH FLOOD
WATCH TO 4 PM THIS AFTERNOON AS ANY CONVECTION THAT OCCURS FROM THAT
POINT ON WILL BE ON TOP OF RAINFALL FROM CONVECTION THIS AM THROUGH
EARLY THIS EVENING. WE ALSO OPTED TO MOVE THE EXPIRATION TIME TO 4 AM
ON SAT AM. MODELS HAVE TRENDED TOWARD A FASTER COLD FRONT...WITH ONLY
SOME ISOLATED TO SCATTERED LINGERING RAIN SHOWERS ON SAT MORNING.
SFC HIGH PRESSURE AND SUBSIDENCE BEHIND THE DEPARTING SYSTEM SHOULD
LEAD TO A MOSTLY DRY DAY ON SAT WITH COLD AND DRY AIR ADVECTION. MAX
T MAY NOT REACH 50 DEGREES ACROSS WESTERN SECTIONS AS A MUCH COLDER
AIRMASS WORKS INTO THE REGION.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 425 AM EST FRI MAR 2 2012
THE MODELS ARE IN GOOD AGREEMENT WITH AN AMPLIFIED LONG WAVE
PATTERN TO CONCLUDE THE WEEK...FOLLOWED BY A TEMPORARY TRANSITION TO
MORE ZONAL FLOW EARLY NEXT WEEK...AND THEN AMPLIFYING ONCE AGAIN
THEREAFTER.
A FULL LATITUDE TROUGH WILL BE MOVING THROUGH THE HEART OF THE
COUNTRY SATURDAY NIGHT...WITH WEAK HIGH PRESSURE HANGING ON AND
PROVIDING DRY WEATHER ACROSS EASTERN KENTUCKY. A COUPLE OF SHORT
WAVE TROUGHS WILL THEN CYCLE IN FROM THE NORTHWEST ON SUNDAY AND
THEN FROM SUNDAY NIGHT INTO MONDAY MORNING. THE LATTER WAVE IS MORE
INTENSE HAS MORE MOISTURE ASSOCIATED WITH IT. HAVE STUCK WITH LIKELY
POPS FOR SUNDAY NIGHT...WHICH SEEMS TO BE THE WINDOW OF BEST
FORCING. TEMPERATURE PROFILES WILL YIELD MAINLY SNOW FOR SUNDAY
NIGHT INTO MONDAY MORNING. AS MENTIONED PREVIOUSLY...A SLUSHY INCH
OF SNOW COULD MAKE FOR SLOW COMMUTE TIMES MONDAY MORNING.
ONCE THIS WAVE MOVES OUT MONDAY AFTERNOON...MODEST RIDGING AND
SURFACE HIGH PRESSURE BUILDING IN AND EVENTUALLY OFF THE EASTERN
SEABOARD WILL BRING MILDER AND GENERALLY DRIER WEATHER FOR THE REST
OF THE PERIOD. BY THE END OF THE WORK WEEK...THERE IS DISAGREEMENT
WITH THE TIMING AND EVOLUTION OF THE NEXT SYSTEM...WITH THE ECMWF
MORE AMPLIFIED IN A SPLIT FLOW PATTERN COMPARED TO THE GFS. HAVE
STUCK WITH THE INITIAL BLENDED GUIDANCE...WHICH KEEPS THE DRY
WEATHER GOING INTO THURSDAY.
FOR TEMPERATURES...GENERALLY SIDED WITH MORE OF A DIURNAL RANGE THEN
THE BLENDED GUIDANCE...ESPECIALLY FOR THE LOW TEMPERATURES IN THE
MORE SHELTERED VALLEYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1234 PM EST FRI MAR 2 2012
A BREAK IN THE SHOWERS AND STORMS IS EXPECTED THIS AFTERNOON AND INTO
EARLY THIS EVENING. HOWEVER...GUSTY CONDITIONS WILL DEVELOP WITH
GUSTS UP TO 30 KNOTS POSSIBLE. THE THREAT FOR SHOWERS AND STORMS WILL
PUSH INTO EASTERN KENTUCKY AROUND 23Z...WITH THE GREATEST THREAT FOR
DOWNBURST WINDS BETWEEN 01 AND 03Z. GIVEN THE LIKELY STRONG
WINDS...HAVE PUT A TEMPO GROUP IN THE TAFS TO ACCOUNT FOR THESE
DOWNBURST WINDS. THE THREAT FOR THUNDERSTORMS WILL END BY MIDNIGHT
WITH SOME LEFTOVER SHOWERS. SKIES WILL BEGIN TO CLEAR OFF
TONIGHT...AND MAY NEED TO WATCH THE POTENTIAL FOR SOME FOG
DEVELOPMENT...BUT GIVEN THE COMPLEX WEATHER THIS EVENING...HAVE OPTED
TO WAIT ON INCLUDING ANY FOG FOR THE TIME BEING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ044-
050>052-058>060-068-069-079-080-083>088-104-106>120.
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR KYZ058>060-068-069-
079-080-083>088-104-106>120.
&&
$$
UPDATE...KAS
SHORT TERM...JP
LONG TERM....GEOGERIAN
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
1234 PM EST FRI MAR 2 2012
.UPDATE...
ISSUED AT 1234 PM EST FRI MAR 2 2012
DRY SLOT IS NOT NOSING INTO OUR SOUTHWEST COUNTIES...ENDING
PRECIPITATION THERE TEMPORARILY. THE SHOWERS AND STORMS SHOULD
CONTINUE TO DEPART TO THE NORTH AND EAST EARLY THIS
AFTERNOON...LEAVING MOST OF EASTERN KENTUCKY DRY FROM MID TO LATE
AFTERNOON. THIS WILL ALLOW TEMPERATURES TO WARM INTO THE MID 70S WITH
SOME BROKEN CIGS SPREADING ACROSS THE AREA. WITH DECENT MIXING
POTENTIAL...WE SHOULD SEE STRONG WINDS MIXING DOWN WITH SOME GUSTS UP
TO 40 MPH LIKELY. CANNOT RULE OUT AN ISOLATED STORM THIS
AFTERNOON...BUT THE MORE LIKELY SCENARIO IS ACTIVITY ARRIVING AHEAD
OF THE FRONTAL BOUNDARY LATER THIS EVENING.
MEANWHILE...SHOWERS AND STORMS ARE ALREADY DEVELOPING ALONG AND JUST
AHEAD OF THE FRONTAL BOUNDARY ACROSS MISSOURI AND ILLINOIS. BASED ON
LATEST HRRR...THIS ACTIVITY SHOULD PUSH INTO OUR BLUEGRASS COUNTIES
TOWARDS 5 OR 6 PM...THEN ACROSS THE REST OF EASTERN KENTUCKY THROUGH
10 PM. EARLY ON...STILL CONCERNED WITH DISCRETE SUPERCELLS...CAPABLE
OF DAMAGING WINDS...LARGE HAIL...AND A TORNADO. AS THE FRONT PUSHES
INTO THE REGION...A SQUALL LINE WILL LIKELY EVOLVE...WITH THE MAIN
THREAT STRAIGHT LINE DAMAGING WINDS. HOWEVER...A SPIN UP TORNADO
ALONG THE LINE IS POSSIBLE STILL. WITH THE FAST MOVEMENT OF
STORMS...THE SEVERE THREAT MAY BE OVER FOR MOST OF THE AREA BY
MIDNIGHT...WITH JUST SOME LEFT OVER RAIN PUSHING ACROSS OUR EASTERN
COUNTIES. HAVE LOWERED TEMPERATURES BEHIND THE FRONT TONIGHT...WITH
DECENT CLEARING SPREADING INTO THE AREA.
UPDATE ISSUED AT 1129 AM EST FRI MAR 2 2012
WIDESPREAD SHOWERS AND STORMS CONTINUE TO PROGRESS NORTHWARD ACROSS
THE CWA THIS MORNING...BUT A DISTINCT BACK EDGE AND DRY SLOT...BEHIND
THE ADVANCING WARM FRONT IS NOTED BACK ACROSS CENTRAL TENNESSEE.
USING THE TIMING TOOL...IT LOOKS LIKE THE ONGOING ACTIVITY SHOULD
PUSH NORTH AND EAST OF THE AREA BY 19Z...PROVIDING A DECENT BREAK FOR
MOST AREAS THIS AFTERNOON. HRRR IS HANDLING THE SITUATION FAIRLY
WELL. IT SHOWS SOME DISTINCT SUPERCELLS DEVELOPING OUT IN THE
BLUEGRASS BETWEEN 21 AND 22Z. THESE MAY IMPACT OUR NORTHEAST BLUEGRASS
COUNTIES AROUND THIS TIME. THESE STORMS WOULD OBVIOUSLY HAVE THE
POTENTIAL FOR LARGE HAIL...DAMAGING WINDS...AND TORNADOES. THESE
STORMS SHOULD DEVELOP OUT AHEAD OF THE ADVANCING COLD FRONT...WITH A
SQUALL LINE DEVELOPING ALONG THE ACTUAL FRONTAL BOUNDARY. THE MAIN
THREAT WITH THE SQUALL LINE WILL BE DAMAGING WINDS...BUT A BRIEF SPIN
UP ALONG THIS LINE IS POSSIBLE...PRODUCING A TORNADO. THE FRONTAL
BOUNDARY SHOULD HOLD OFF TO OUR WEST UNTIL AT LEAST 00Z. SO THE MAIN
THREAT PRIOR TO THAT TIME WILL BE THE DISCRETE SUPERCELLS IN THE WARM
SECTOR. WARM AND MUGGY CONDITIONS WILL DEVELOP HEADING INTO THIS
AFTERNOON WITH DEWPOINTS CLIMBING UP TO AROUND 60 WITH TEMPERATURES
AROUND 70. CERTAINLY JUICY AIR FOR THIS TIME OF YEAR. LAKE WIND
ADVISORY WILL CONTINUE AS ADVERTISED. FLASH FLOOD THREAT ALSO APPEARS
A BIT ENHANCED WITH EARLY DAY RAINFALL ADDING TO THE ALREADY SOAKED
GROUND AND BANK FULL CREEKS.
UPDATE ISSUED AT 837 AM EST FRI MAR 2 2012
SHOWERS AND THUNDERSTORMS HAVE BECOME MORE WIDESPREAD ACROSS THE AREA
OVER THE PAST HOUR. THUS...HAVE BROUGHT IN SOME HIGHER CATEGORICAL
POPS THROUGH THIS MORNING. ANOTHER BAND OF SHOWERS AND STORMS IS
KNOCKING AT OUR DOORSTEP...JUST NOW PUSHING INTO AREAS AROUND
MONTICELLO. AFTER THE MORNING CONVECTION...STILL LOOKING LIKE A
POTENTIAL BREAK BY MID AFTERNOON...BEFORE THE MAIN LINE OF CONVECTION
ARRIVES WITH THE FRONT BETWEEN 6 AND 9 PM. HAD SOME REPORTS OF
SUB-SEVERE HAIL THIS MORNING (HAIL LESS THAN AN INCH IN
DIAMETER)...BUT NOTHING SEVERE AS OF YET. MADE SOME TWEAKS TO
TEMPERATURES AND DEWPOINTS AS TEMPERATURES START TO WARM FROM SOUTH
TO NORTH AS THE FRONT PROGRESSES NORTHWARD.
UPDATE ISSUED AT 705 AM EST FRI MAR 2 2012
THE FORECAST IN GENERAL REMAINS ON TARGET...THOUGH CONVECTION UP UNTIL
THIS POINT HAS NOT BEEN ALL THAT WIDESPREAD. HOWEVER...ADDITIONAL
STRONG TO POSSIBLY SEVERE CONVECTION CONTINUES TO GET GOING TO OUR
SW IN NORTHERN MIDDLE TN AND SOME OF THIS ACTIVITY SHOULD LIFT NORTH
INTO THE REGION THROUGH MID TO LATE MORNING. ACTIVITY THIS MORNING
IS EXPECTED TO BE LARGELY ELEVATED AND EITHER WITH ONGOING CONVECTION
APPROACHING FROM CENTRAL KY AND THE CONVECTION APPROACHING FROM
MIDDLE TN WILL HAVE THE POTENTIAL TO PRODUCE HAIL...AND PERHAPS SOME
STRONGER WIND GUSTS.
ONCE THE WARM FRONT PASSES DURING THE MID AFTERNOON...THERE IS NOT A
LOT OF CONVECTIVE TRIGGERS...BUT ANY OUTFLOWS OR CONVECTION UPSTREAM
THAT MOVES IN OR ANY BREAKS IN THE CLOUDS COULD BE THE FOCUS FOR
INITIATION. OTHER THAN THE QUESTION OF A TRIGGER DURING MID AFTERNOON
AND SOME HINT OF MID LEVEL CAPPING IN THE FORECAST SOUNDINGS...IF
ANYTHING WERE TO GET GOING IT COULD BECOME SEVERE AS SHEAR WILL BE
AMPLE. IF THIS WERE TO BE IN SUPERCELL FORM...DAMAGING WINDS...LARGE
HAIL...AN EVEN A TORNADO WOULD BE POSSIBLE. IT STILL APPEARS THAT THE
MOST ORGANIZED SEVERE CONVECTION SHOULD OCCUR DURING THE LATE
AFTERNOON INTO THE EVENING HOURS.
HOURLY GRIDS WERE FRESHENED UP BASED ON THE LATEST TRENDS...BUT THE
PREVIOUS ZFP WAS STILL HANDLING THE SITUATION AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 430 AM EST FRI MAR 2 2012
SFC LOW PRESSURE OVER NE OKLAHOMA CONTINUES TO DEVELOP THIS MORNING
WITH A SFC WARM FRONT EXTENDING EAST INTO THE TN VALLEY REGION. AT
PRESENT IT IS ABOUT 2 MB STRONGER THAN THE 6Z NAM RUNS AND SLIGHTLY
STRONGER THAN MOST OF THE 0Z MODEL RUNS. THIS SYSTEM IS PROGGED TO
FURTHER DEEPEN AS IT TRACKS INTO THE GREAT LAKES THIS EVENING...WITH
THE MOST RAPID DEEPENING OCCURRING BETWEEN 18Z AND 0Z TONIGHT. THIS
SYSTEM WILL SEND A STRONG COLD FRONT INTO THE COMMONWEALTH...WITH THE
COLD FRONT REACHING THE JKL CWA DURING THE EVENING. THE COLD FRONT
SHOULD EXIT INTO VA EARLY ON AT AM.
DESPITE RELATIVELY CLOUD FREE CONDITIONS AT PRESENT WITH SOME VALLEY
LOCATIONS AT PRESENT IN THE 30S...A RATHER DRAMATIC RISE IN TEMPS AND
DEWPOINTS IS ANTICIPATED TODAY AS THE WARM FRONT LIFTS INTO THE
REGION FROM THE SOUTH AND WEST...MOVING NORTH AND EAST OF THE JKL CWA
BY EARLY TO MID AFTERNOON. DEWPOINTS ACROSS THE CWA ARE CURRENTLY IN
THE UPPER 20S AND 30S...BUT JUST SOUTH OF THE AREA DEWPOINTS IN THE
MID 40S ARE PRESENT ACROSS NORTHERN MIDDLE TN...THE 50S TO THE SOUTH
OF THAT AREA MIDDLE AND EAST TN AND THEN FURTHER SOUTH IN MS AND
AL...DEWPOINTS ARE IN THE LOWER 60S.
MODELS ALL PROG A RAPID INCREASE IN MOISTURE THIS MORNING AS THE WARM
FRONT MOVES INTO AND ACROSS THE AREA...AS HAS BEEN OCCURRING TO OUR SOUTH
AND WEST OVERNIGHT. AN AREA OF SHOWERS AND THUNDERSTORMS CONTINUES
TO DEVELOP FROM WEST CENTRAL KY SE INTO THE CUMBERLAND PLATEAU OF
MIDDLE TN. THIS CONVECTION SHOULD CONTINUE TO DEVELOP EARLY THIS
MORNING AND BECOME MORE WIDESPREAD AS MOISTURE TRANSPORT INCREASES AS
THE LOW LEVEL JET INCREASES. A ROUND OF SHOWERS AND AT LEAST SCATTERED
THUNDERSTORMS SHOULD OCCUR THIS MORNING. INSTABILITY IS PROGGED TO BE
RATHER LIMITED AND THIS CONVECTION ELEVATED...BUT THE STRONGEST
STORMS COULD PRODUCE SOME SMALL HAIL. WARM AND MOIST ADVECTION WILL
CONTINUE INTO THE AFTERNOON AS THE SFC LOW TRACKS BY TO OUR WEST. MID
LEVEL WARMING IN THE WARM SECTOR WILL LIKELY LEAD TO A LULL IN
PRECIPITATION CHANCES SPREADING FROM SOUTHWEST TO NORTHEAST IN THE
AFTERNOON. WITH THE SYSTEM ALREADY A BIT STRONGER THAN CURRENTLY
FORECAST BY THE MODELS OPTED TO GO TOWARD THE WARMER END OF GUIDANCE
FOR MAX AND WINDS THIS AFTERNOON. SINCE CONVECTION WILL BE LARGELY
ISOLATED TO SCATTERED IN THE AFTERNOON AND STRONG WINDS FIELDS ARE
PROGGED ALOFT...GUSTS OF 35 TO 40 MPH MAY OCCUR OUTSIDE OF SHOWER AND
THUNDERSTORM ACTIVITY. WITH THIS IN MIND WENT WITH A LAKE WIND
ADVISORY FROM NOON UNTIL 7 PM TODAY. ANY CONVECTION BY MID TO LATE
AFTERNOON WOULD HAVE THE POTENTIAL TO BE IN THE FORM OF CLUSTERS OR
SUPERCELLS DUE TO STRONG WIND FIELDS ALOFT AND AMPLE SHEAR.
INSTABILITY IN THE AFTERNOON DOES APPEAR TO BE SOMEWHAT LIMITED
THOUGH AND SOME MID LEVEL CAPPING MAY BE PRESENT WITH NOT MUCH OF A
TRIGGER.
THE HIGHEST THREAT FOR SEVERE THUNDERSTORMS...A MODERATE RISK IN THE
DAY 1 SPC OUTLOOK APPEARS TO BE FROM LATE AFTERNOON OR EARLY EVENING
AND CONTINUING INTO THE EVENING IN ADVANCE OF AND POSSIBLY ALONG THE
SFC COLD FRONT. HOWEVER...GIVEN THE STRENGTH OF THE DEVELOPING SYSTEM
AND WIND FIELDS ALOFT...ANY STRONGER STORM DURING THE DAY COULD ALSO
PRODUCE DAMAGING WINDS...WITH ANY SUPERCELLS THAT DEVELOP HAVING A
LARGE HAIL AND ISOLATED TORNADO THREAT AS THE LOWER LEVELS EVENTUALLY
WILL BE MORE SATURATED. SUPERCELLS OR STORM CLUSTERS ONGOING LATE IN
THE AFTERNOON OVER CENTRAL AND PERHAPS INTO EASTERN KY SHOULD EVOLVE
INTO A QLCS TYPE SYSTEM DURING THE EVENING AS THE FRONT APPROACHES
AND RACE ACROSS THE CWA. THIS STORMS WOULD ALSO HAVE THE POTENTIAL TO
PRODUCE DAMAGING WINDS...LARGE HAIL...LOCALLY HEAVY RAIN AND ISOLATED
POSSIBLY STRONG TORNADOES. THE PERIOD OF THREAT FOR THE LARGEST HAIL
MAY BE FROM VERY LATE IN THE AFTERNOON THROUGH EARLY IN THE EVENING
AS CONSIDERABLE MID LEVEL DRY AIR IS PROGGED...LEADING TO LOW WBZ
HEIGHTS NEAR 8KFT LATE AFTERNOON AND EARLY IN THE EVENING. ANY
ROTATING CELLS WOULD HAVE MORE VIGOROUS UPDRAFTS HIS PERIOD AND WOULD
BRING A LARGE HAIL THREAT.
WITH THE FRONT AT LEAST BRIEFLY BECOMING PARALLEL TO THE UPPER LEVEL
FLOW...SOME TRAINING OF CONVECTION MAY OCCUR FROM LATE THIS AFTERNOON
THROUGH EARLY THIS EVENING ON TOP OF ALREADY WET GROUND FROM RECENT IN
MAY PLACES HEAVY PRECIPITATION. ANY TRAINING WOULD BRING A THREAT FOR
FLASH FLOODING. MODELS OVERALL HAVE TRENDED BACK ON THE QPF...BUT
LOCALLY HIGHER AMOUNTS ARE VERY POSSIBLE WITH THE STRONGER CELLS AND
IN ANY TRAINING. OPTED TO CHANGE THE START TIME OF THE FLASH FLOOD
WATCH TO 4 PM THIS AFTERNOON AS ANY CONVECTION THAT OCCURS FROM THAT
POINT ON WILL BE ON TOP OF RAINFALL FROM CONVECTION THIS AM THROUGH
EARLY THIS EVENING. WE ALSO OPTED TO MOVE THE EXPIRATION TIME TO 4 AM
ON SAT AM. MODELS HAVE TRENDED TOWARD A FASTER COLD FRONT...WITH ONLY
SOME ISOLATED TO SCATTERED LINGERING RAIN SHOWERS ON SAT MORNING.
SFC HIGH PRESSURE AND SUBSIDENCE BEHIND THE DEPARTING SYSTEM SHOULD
LEAD TO A MOSTLY DRY DAY ON SAT WITH COLD AND DRY AIR ADVECTION. MAX
T MAY NOT REACH 50 DEGREES ACROSS WESTERN SECTIONS AS A MUCH COLDER
AIRMASS WORKS INTO THE REGION.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 425 AM EST FRI MAR 2 2012
THE MODELS ARE IN GOOD AGREEMENT WITH AN AMPLIFIED LONG WAVE
PATTERN TO CONCLUDE THE WEEK...FOLLOWED BY A TEMPORARY TRANSITION TO
MORE ZONAL FLOW EARLY NEXT WEEK...AND THEN AMPLIFYING ONCE AGAIN
THEREAFTER.
A FULL LATITUDE TROUGH WILL BE MOVING THROUGH THE HEART OF THE
COUNTRY SATURDAY NIGHT...WITH WEAK HIGH PRESSURE HANGING ON AND
PROVIDING DRY WEATHER ACROSS EASTERN KENTUCKY. A COUPLE OF SHORT
WAVE TROUGHS WILL THEN CYCLE IN FROM THE NORTHWEST ON SUNDAY AND
THEN FROM SUNDAY NIGHT INTO MONDAY MORNING. THE LATTER WAVE IS MORE
INTENSE HAS MORE MOISTURE ASSOCIATED WITH IT. HAVE STUCK WITH LIKELY
POPS FOR SUNDAY NIGHT...WHICH SEEMS TO BE THE WINDOW OF BEST
FORCING. TEMPERATURE PROFILES WILL YIELD MAINLY SNOW FOR SUNDAY
NIGHT INTO MONDAY MORNING. AS MENTIONED PREVIOUSLY...A SLUSHY INCH
OF SNOW COULD MAKE FOR SLOW COMMUTE TIMES MONDAY MORNING.
ONCE THIS WAVE MOVES OUT MONDAY AFTERNOON...MODEST RIDGING AND
SURFACE HIGH PRESSURE BUILDING IN AND EVENTUALLY OFF THE EASTERN
SEABOARD WILL BRING MILDER AND GENERALLY DRIER WEATHER FOR THE REST
OF THE PERIOD. BY THE END OF THE WORK WEEK...THERE IS DISAGREEMENT
WITH THE TIMING AND EVOLUTION OF THE NEXT SYSTEM...WITH THE ECMWF
MORE AMPLIFIED IN A SPLIT FLOW PATTERN COMPARED TO THE GFS. HAVE
STUCK WITH THE INITIAL BLENDED GUIDANCE...WHICH KEEPS THE DRY
WEATHER GOING INTO THURSDAY.
FOR TEMPERATURES...GENERALLY SIDED WITH MORE OF A DIURNAL RANGE THEN
THE BLENDED GUIDANCE...ESPECIALLY FOR THE LOW TEMPERATURES IN THE
MORE SHELTERED VALLEYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1234 PM EST FRI MAR 2 2012
A BREAK IN THE SHOWERS AND STORMS IS EXPECTED THIS AFTERNOON AND INTO
EARLY THIS EVENING. HOWEVER...GUSTY CONDITIONS WILL DEVELOP WITH
GUSTS UP TO 30 KNOTS POSSIBLE. THE THREAT FOR SHOWERS AND STORMS WILL
PUSH INTO EASTERN KENTUCKY AROUND 23Z...WITH THE GREATEST THREAT FOR
DOWNBURST WINDS BETWEEN 01 AND 03Z. GIVEN THE LIKELY STRONG
WINDS...HAVE PUT A TEMPO GROUP IN THE TAFS TO ACCOUNT FOR THESE
DOWNBURST WINDS. THE THREAT FOR THUNDERSTORMS WILL END BY MIDNIGHT
WITH SOME LEFTOVER SHOWERS. SKIES WILL BEGIN TO CLEAR OFF
TONIGHT...AND MAY NEED TO WATCH THE POTENTIAL FOR SOME FOG
DEVELOPMENT...BUT GIVEN THE COMPLEX WEATHER THIS EVENING...HAVE OPTED
TO WAIT ON INCLUDING ANY FOG FOR THE TIME BEING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ044-
050>052-058>060-068-069-079-080-083>088-104-106>120.
FLASH FLOOD WATCH FROM 4 PM EST THIS AFTERNOON THROUGH LATE
TONIGHT FOR KYZ058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...KAS
SHORT TERM...JP
LONG TERM....GEOGERIAN
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
1130 AM EST FRI MAR 2 2012
.UPDATE...
ISSUED AT 1129 AM EST FRI MAR 2 2012
WIDESPREAD SHOWERS AND STORMS CONTINUE TO PROGRESS NORTHWARD ACROSS
THE CWA THIS MORNING...BUT A DISTINCT BACK EDGE AND DRY SLOT...BEHIND
THE ADVANCING WARM FRONT IS NOTED BACK ACROSS CENTRAL TENNESSEE.
USING THE TIMING TOOL...IT LOOKS LIKE THE ONGOING ACTIVITY SHOULD
PUSH NORTH AND EAST OF THE AREA BY 19Z...PROVIDING A DECENT BREAK FOR
MOST AREAS THIS AFTERNOON. HRRR IS HANDLING THE SITUATION FAIRLY
WELL. IT SHOWS SOME DISTINCT SUPERCELLS DEVELOPING OUT IN THE
BLUEGRASS BETWEEN 21 AND 22Z. THESE MAY IMACT OUR NORTHEAST BLUEGRASS
COUNTIES AROUND THIS TIME. THESE STORMS WOULD OBVIOUSLY HAVE THE
POTENTIAL FOR LARGE HAIL...DAMAGING WINDS...AND TORNADOES. THESE
STORMS SHOULD DEVELOP OUT AHEAD OF THE ADVANCING COLD FRONT...WITH A
SQUALL LINE DEVELOPING ALONG THE ACTUAL FRONTAL BOUNDARY. THE MAIN
THREAT WITH THE SQUALL LINE WILL BE DAMAGING WINDS...BUT A BRIEF SPIN
UP ALONG THIS LINE IS POSSIBLE...PRODUCING A TORNADO. THE FRONTAL
BOUNDARY SHOULD HOLD OFF TO OUR WEST UNTIL AT LEAST 00Z. SO THE MAIN
THREAT PRIOR TO THAT TIME WILL BE THE DISCRETE SUPERCELLS IN THE WARM
SECTOR. WARM AND MUGGY CONDITIONS WILL DEVELOP HEADING INTO THIS
AFTERNOON WITH DEWPOINTS CLIMBING UP TO AROUND 60 WITH TEMPERATURES
AROUND 70. CERTAINLY JUICY AIR FOR THIS TIME OF YEAR. LAKE WIND
ADVISORY WILL CONTINUE AS ADVERTISED. FLASH FLOOD THREAT ALSO APPEARS
A BIT ENHANCED WITH EARLY DAY RAINFALL ADDING TO THE ALREADY SOAKED
GROUND AND BANK FULL CREEKS.
UPDATE ISSUED AT 837 AM EST FRI MAR 2 2012
SHOWERS AND THUNDERSTORMS HAVE BECOME MORE WIDESPREAD ACROSS THE AREA
OVER THE PAST HOUR. THUS...HAVE BROUGHT IN SOME HIGHER CATEGORICAL
POPS THROUGH THIS MORNING. ANOTHER BAND OF SHOWERS AND STORMS IS
KNOCKING AT OUR DOORSTEP...JUST NOW PUSHING INTO AREAS AROUND
MONTICELLO. AFTER THE MORNING CONVECTION...STILL LOOKING LIKE A
POTENTIAL BREAK BY MID AFTERNOON...BEFORE THE MAIN LINE OF CONVECTION
ARRIVES WITH THE FRONT BETWEEN 6 AND 9 PM. HAD SOME REPORTS OF
SUBSEVERE HAIL THIS MORNING (HAIL LESS THAN AN INCH IN
DIAMETER)...BUT NOTHING SEVERE AS OF YET. MADE SOME TWEAKS TO
TEMPERATURES AND DEWPOINTS AS TEMPERATURES START TO WARM FROM SOUTH
TO NORTH AS THE FRONT PROGRESSES NORTHWARD.
UPDATE ISSUED AT 705 AM EST FRI MAR 2 2012
THE FORECAST IN GENERAL REMAINS ON TARGET...THOUGH CONVECTION UP UNTIL
THIS POINT HAS NOT BEEN ALL THAT WIDESPREAD. HOWEVER...ADDITIONAL
STRONG TO POSSIBLY SEVERE CONVECTION CONTINUES TO GET GOING TO OUR
SW IN NORTHERN MIDDLE TN AND SOME OF THIS ACTIVITY SHOULD LIFT NORTH
INTO THE REGION THROUGH MID TO LATE MORNING. ACTIVITY THIS MORNING
IS EXPECTED TO BE LARGELY ELEVATED AND EITHER WITH ONGOING CONVECTION
APPROACHING FROM CENTRAL KY AND THE CONVECTION APPROACHING FROM
MIDDLE TN WILL HAVE THE POTENTIAL TO PRODUCE HAIL...AND PERHAPS SOME
STRONGER WIND GUSTS.
ONCE THE WARM FRONT PASSES DURING THE MID AFTERNOON...THERE IS NOT A
LOT OF CONVECTIVE TRIGGERS...BUT ANY OUTFLOWS OR CONVECTION UPSTREAM
THAT MOVES IN OR ANY BREAKS IN THE CLOUDS COULD BE THE FOCUS FOR
INITIATION. OTHER THAN THE QUESTION OF A TRIGGER DURING MID AFTERNOON
AND SOME HINT OF MID LEVEL CAPPING IN THE FORECAST SOUNDINGS...IF
ANYTHING WERE TO GET GOING IT COULD BECOME SEVERE AS SHEAR WILL BE
AMPLE. IF THIS WERE TO BE IN SUPERCELL FORM...DAMAGING WINDS...LARGE
HAIL...AN EVEN A TORNADO WOULD BE POSSIBLE. IT STILL APPEARS THAT THE
MOST ORGANIZED SEVERE CONVECTION SHOULD OCCUR DURING THE LATE
AFTERNOON INTO THE EVENING HOURS.
HOURLY GRIDS WERE FRESHENED UP BASED ON THE LATEST TRENDS...BUT THE
PREVIOUS ZFP WAS STILL HANDLING THE SITUATION AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 430 AM EST FRI MAR 2 2012
SFC LOW PRESSURE OVER NE OKLAHOMA CONTINUES TO DEVELOP THIS MORNING
WITH A SFC WARM FRONT EXTENDING EAST INTO THE TN VALLEY REGION. AT
PRESENT IT IS ABOUT 2 MB STRONGER THAN THE 6Z NAM RUNS AND SLIGHTLY
STRONGER THAN MOST OF THE 0Z MODEL RUNS. THIS SYSTEM IS PROGGED TO
FURTHER DEEPEN AS IT TRACKS INTO THE GREAT LAKES THIS EVENING...WITH
THE MOST RAPID DEEPENING OCCURRING BETWEEN 18Z AND 0Z TONIGHT. THIS
SYSTEM WILL SEND A STRONG COLD FRONT INTO THE COMMONWEALTH...WITH THE
COLD FRONT REACHING THE JKL CWA DURING THE EVENING. THE COLD FRONT
SHOULD EXIT INTO VA EARLY ON AT AM.
DESPITE RELATIVELY CLOUD FREE CONDITIONS AT PRESENT WITH SOME VALLEY
LOCATIONS AT PRESENT IN THE 30S...A RATHER DRAMATIC RISE IN TEMPS AND
DEWPOINTS IS ANTICIPATED TODAY AS THE WARM FRONT LIFTS INTO THE
REGION FROM THE SOUTH AND WEST...MOVING NORTH AND EAST OF THE JKL CWA
BY EARLY TO MID AFTERNOON. DEWPOINTS ACROSS THE CWA ARE CURRENTLY IN
THE UPPER 20S AND 30S...BUT JUST SOUTH OF THE AREA DEWPOINTS IN THE
MID 40S ARE PRESENT ACROSS NORTHERN MIDDLE TN...THE 50S TO THE SOUTH
OF THAT AREA MIDDLE AND EAST TN AND THEN FURTHER SOUTH IN MS AND
AL...DEWPOINTS ARE IN THE LOWER 60S.
MODELS ALL PROG A RAPID INCREASE IN MOISTURE THIS MORNING AS THE WARM
FRONT MOVES INTO AND ACROSS THE AREA...AS HAS BEEN OCCURRING TO OUR SOUTH
AND WEST OVERNIGHT. AN AREA OF SHOWERS AND THUNDERSTORMS CONTINUES
TO DEVELOP FROM WEST CENTRAL KY SE INTO THE CUMBERLAND PLATEAU OF
MIDDLE TN. THIS CONVECTION SHOULD CONTINUE TO DEVELOP EARLY THIS
MORNING AND BECOME MORE WIDESPREAD AS MOISTURE TRANSPORT INCREASES AS
THE LOW LEVEL JET INCREASES. A ROUND OF SHOWERS AND AT LEAST SCATTERED
THUNDERSTORMS SHOULD OCCUR THIS MORNING. INSTABILITY IS PROGGED TO BE
RATHER LIMITED AND THIS CONVECTION ELEVATED...BUT THE STRONGEST
STORMS COULD PRODUCE SOME SMALL HAIL. WARM AND MOIST ADVECTION WILL
CONTINUE INTO THE AFTERNOON AS THE SFC LOW TRACKS BY TO OUR WEST. MID
LEVEL WARMING IN THE WARM SECTOR WILL LIKELY LEAD TO A LULL IN
PRECIPITATION CHANCES SPREADING FROM SOUTHWEST TO NORTHEAST IN THE
AFTERNOON. WITH THE SYSTEM ALREADY A BIT STRONGER THAN CURRENTLY
FORECAST BY THE MODELS OPTED TO GO TOWARD THE WARMER END OF GUIDANCE
FOR MAX AND WINDS THIS AFTERNOON. SINCE CONVECTION WILL BE LARGELY
ISOLATED TO SCATTERED IN THE AFTERNOON AND STRONG WINDS FIELDS ARE
PROGGED ALOFT...GUSTS OF 35 TO 40 MPH MAY OCCUR OUTSIDE OF SHOWER AND
THUNDERSTORM ACTIVITY. WITH THIS IN MIND WENT WITH A LAKE WIND
ADVISORY FROM NOON UNTIL 7 PM TODAY. ANY CONVECTION BY MID TO LATE
AFTERNOON WOULD HAVE THE POTENTIAL TO BE IN THE FORM OF CLUSTERS OR
SUPERCELLS DUE TO STRONG WIND FIELDS ALOFT AND AMPLE SHEAR.
INSTABILITY IN THE AFTERNOON DOES APPEAR TO BE SOMEWHAT LIMITED
THOUGH AND SOME MID LEVEL CAPPING MAY BE PRESENT WITH NOT MUCH OF A
TRIGGER.
THE HIGHEST THREAT FOR SEVERE THUNDERSTORMS...A MODERATE RISK IN THE
DAY 1 SPC OUTLOOK APPEARS TO BE FROM LATE AFTERNOON OR EARLY EVENING
AND CONTINUING INTO THE EVENING IN ADVANCE OF AND POSSIBLY ALONG THE
SFC COLD FRONT. HOWEVER...GIVEN THE STRENGTH OF THE DEVELOPING SYSTEM
AND WIND FIELDS ALOFT...ANY STRONGER STORM DURING THE DAY COULD ALSO
PRODUCE DAMAGING WINDS...WITH ANY SUPERCELLS THAT DEVELOP HAVING A
LARGE HAIL AND ISOLATED TORNADO THREAT AS THE LOWER LEVELS EVENTUALLY
WILL BE MORE SATURATED. SUPERCELLS OR STORM CLUSTERS ONGOING LATE IN
THE AFTERNOON OVER CENTRAL AND PERHAPS INTO EASTERN KY SHOULD EVOLVE
INTO A QLCS TYPE SYSTEM DURING THE EVENING AS THE FRONT APPROACHES
AND RACE ACROSS THE CWA. THIS STORMS WOULD ALSO HAVE THE POTENTIAL TO
PRODUCE DAMAGING WINDS...LARGE HAIL...LOCALLY HEAVY RAIN AND ISOLATED
POSSIBLY STRONG TORNADOES. THE PERIOD OF THREAT FOR THE LARGEST HAIL
MAY BE FROM VERY LATE IN THE AFTERNOON THROUGH EARLY IN THE EVENING
AS CONSIDERABLE MID LEVEL DRY AIR IS PROGGED...LEADING TO LOW WBZ
HEIGHTS NEAR 8KFT LATE AFTERNOON AND EARLY IN THE EVENING. ANY
ROTATING CELLS WOULD HAVE MORE VIGOROUS UPDRAFTS HIS PERIOD AND WOULD
BRING A LARGE HAIL THREAT.
WITH THE FRONT AT LEAST BRIEFLY BECOMING PARALLEL TO THE UPPER LEVEL
FLOW...SOME TRAINING OF CONVECTION MAY OCCUR FROM LATE THIS AFTERNOON
THROUGH EARLY THIS EVENING ON TOP OF ALREADY WET GROUND FROM RECENT IN
MAY PLACES HEAVY PRECIPITATION. ANY TRAINING WOULD BRING A THREAT FOR
FLASH FLOODING. MODELS OVERALL HAVE TRENDED BACK ON THE QPF...BUT
LOCALLY HIGHER AMOUNTS ARE VERY POSSIBLE WITH THE STRONGER CELLS AND
IN ANY TRAINING. OPTED TO CHANGE THE START TIME OF THE FLASH FLOOD
WATCH TO 4 PM THIS AFTERNOON AS ANY CONVECTION THAT OCCURS FROM THAT
POINT ON WILL BE ON TOP OF RAINFALL FROM CONVECTION THIS AM THROUGH
EARLY THIS EVENING. WE ALSO OPTED TO MOVE THE EXPIRATION TIME TO 4 AM
ON SAT AM. MODELS HAVE TRENDED TOWARD A FASTER COLD FRONT...WITH ONLY
SOME ISOLATED TO SCATTERED LINGERING RAIN SHOWERS ON SAT MORNING.
SFC HIGH PRESSURE AND SUBSIDENCE BEHIND THE DEPARTING SYSTEM SHOULD
LEAD TO A MOSTLY DRY DAY ON SAT WITH COLD AND DRY AIR ADVECTION. MAX
T MAY NOT REACH 50 DEGREES ACROSS WESTERN SECTIONS AS A MUCH COLDER
AIRMASS WORKS INTO THE REGION.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 425 AM EST FRI MAR 2 2012
THE MODELS ARE IN GOOD AGREEMENT WITH AN AMPLIFIED LONG WAVE
PATTERN TO CONCLUDE THE WEEK...FOLLOWED BY A TEMPORARY TRANSITION TO
MORE ZONAL FLOW EARLY NEXT WEEK...AND THEN AMPLIFYING ONCE AGAIN
THEREAFTER.
A FULL LATITUDE TROUGH WILL BE MOVING THROUGH THE HEART OF THE
COUNTRY SATURDAY NIGHT...WITH WEAK HIGH PRESSURE HANGING ON AND
PROVIDING DRY WEATHER ACROSS EASTERN KENTUCKY. A COUPLE OF SHORT
WAVE TROUGHS WILL THEN CYCLE IN FROM THE NORTHWEST ON SUNDAY AND
THEN FROM SUNDAY NIGHT INTO MONDAY MORNING. THE LATTER WAVE IS MORE
INTENSE HAS MORE MOISTURE ASSOCIATED WITH IT. HAVE STUCK WITH LIKELY
POPS FOR SUNDAY NIGHT...WHICH SEEMS TO BE THE WINDOW OF BEST
FORCING. TEMPERATURE PROFILES WILL YIELD MAINLY SNOW FOR SUNDAY
NIGHT INTO MONDAY MORNING. AS MENTIONED PREVIOUSLY...A SLUSHY INCH
OF SNOW COULD MAKE FOR SLOW COMMUTE TIMES MONDAY MORNING.
ONCE THIS WAVE MOVES OUT MONDAY AFTERNOON...MODEST RIDGING AND
SURFACE HIGH PRESSURE BUILDING IN AND EVENTUALLY OFF THE EASTERN
SEABOARD WILL BRING MILDER AND GENERALLY DRIER WEATHER FOR THE REST
OF THE PERIOD. BY THE END OF THE WORK WEEK...THERE IS DISAGREEMENT
WITH THE TIMING AND EVOLUTION OF THE NEXT SYSTEM...WITH THE ECMWF
MORE AMPLIFIED IN A SPLIT FLOW PATTERN COMPARED TO THE GFS. HAVE
STUCK WITH THE INITIAL BLENDED GUIDANCE...WHICH KEEPS THE DRY
WEATHER GOING INTO THURSDAY.
FOR TEMPERATURES...GENERALLY SIDED WITH MORE OF A DIURNAL RANGE THEN
THE BLENDED GUIDANCE...ESPECIALLY FOR THE LOW TEMPERATURES IN THE
MORE SHELTERED VALLEYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 705 AM EST FRI MAR 2 2012
AN APPROACHING WARM FRONT IS BRINGING AN INCREASE AND LOWERING IN
CLOUDS AT PRESENT ALONG WITH SCATTERED TO NUMEROUS SHOWERS AND
ISOALTED THUNDERSTORMS. MOST OF THE THUNDERSTORMS IN THE NEXT COUPLE
OF HOURS SHOULD REMAIN NORTH AND NORTHWEST OF THE TAF SITES. THE
THREAT FOR SHOWERS BY DAWN...MAINLY ACROSS THE SE CWA. IT STILL
APPEARS ADDITIONAL SHOWERS AND ISOLATED TO SCATTERED THUNDERSTORMS
ARE ANTICIPATED THROUGH ABOUT 18Z TO 19Z AS THE WARM FRONT SHIFTS
NORTH ACROSS THE AREA. A LULL IN THE PRECIP THREAT APPEARS TO EXIST
BETWEEN ABOUT 19Z AND 01Z.
FOCUS DURING THE LAST 12 TO 18 HRS OF THE PERIOD CENTERES AROUND A
LOW PRESSURE SYSTEM THAT WILL TRACK NW OF THE AREA AND SEND A COLD
FRONT ACROSS THE COMMONWEALTH THIS AFTERNOON AND EVENING. THERE IS
STILL SOME UNCERTAINTY OVER THE EVOLUTION OF THIS SYSTEM...PARTICULARLY
TIMING AND STRENGTH OF CONVECTIVE DEVELOPMENT...BUT MODELS CONTINUE
TO INDICATE A THREAT FOR SEVERE WEATHER...GENERALLY DURING THE
AFTERNOON AND PARTICULARLY THE EVENING HOURS OVER ERN KY. SOUTH WINDS
WILL BEGIN RAMPING UP AFTER 12Z...AS THE LOW LEVEL INVERSION WILL
GRADUALLY MIX OUT...BUT A BIT LATER THAN TYPICAL DUE TO PRECIP
KEEPING THE LOW LEVEL INVERSION IN PLACE WELL INTO THE AM. THIS WILL
CREATE A POTENTIAL FOR LLWS LINGERING THROUGH ABOUT 14Z OR 15Z OR SO.
CIGS WILL CONTINUE TO BUILD DOWN INTO THE MVFR RANGE AS THE MORNING
PROGRESSES AS THE ATMOSPHERE SATURATES FROM THE TOP DOWN. AROUND THE
END TIME OF THE PRECIP ASSOCIATED WITH THE WARM FRONT...OR ABOUT 17Z
AND AFTER SUSTAINED WINDS AND GUSTS SHOULD PICK UP WITH SUSTAINED
WINDS OF 10 TO 20KT AND SOME GUSTS NEARING 30KT POSSIBLE BETWEEN
ABOUT 17Z AND 01Z...EVEN OUTSIDE OF CONVECTION. CONFIDENCE AND
TIMING IN WIDESPREAD ORGANIZED SEVERE CONVECTION BEFORE 22Z IS RATHER
LOW...BUT A LINE OF STRONG TO SEVERE THUNDERSTORMS SHOULD AFFECT THE
TAF SITES BETWEEN 0Z AND 6Z. EXCEPT FOR THIS PERIOD... HIGHLIGHTED
THE THREAT FOR CONVECTION WITH CB GROUPS AND OR VCTS. MVFR CIGS SHOULD
LINGER BEHIND THE FRONT UNTIL THE END OF THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ044-
050>052-058>060-068-069-079-080-083>088-104-106>120.
FLASH FLOOD WATCH FROM 4 PM EST THIS AFTERNOON THROUGH LATE
TONIGHT FOR KYZ058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...KAS
SHORT TERM...JP
LONG TERM....GEOGERIAN
AVIATION...JP
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1022 PM EST SAT MAR 3 2012
.SYNOPSIS...
LOW PRESSURE DEVELOPS ALONG A STALLED FRONTAL BOUNDARY AND MOVES UP
THE SOUTHEAST COAST OVERNIGHT...BEFORE MOVING AWAY FROM THE COAST
OFF THE OUTER BANKS SUNDAY MORNING. HIGH PRESSURE BRIEFLY BUILDS
IN SUNDAY AFTERNOON AND SUNDAY NIGHT FOLLOWED BY A QUICK MOVING
LOW PRESSURE SYSTEM...WHICH TRACK ACROSS THE VIRGINIA NORTH
CAROLINA BORDER MONDAY. HIGH PRESSURE RETURNS MONDAY NIGHT AND
TUESDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
INCREASED POPS A BIT MORE ACROSS COASTAL NE NC THIS EVENING AS
RAIN HAS BEGUN TO OVERSPREAD EASTERN NC FAIRLY WELL. FURTHER TO
THE NORTH...DRIER AIR IN THE LOW-LEVELS IS KEEPING RAIN FROM
GETTING ANY FURTHER NORTH SO ONLY HAVE CHC POPS AS FAR NORTH AS
THE VA TIDEWATER THROUGH 06Z. 00Z NAM AND LATEST HRRR STILL
SUPPORT PRECIP EVENTUALLY GETTING FURTHER NORTHEAST OVERNIGHT...WITH
BEST CHANCE EXTENDING FROM THE VA EASTERN SHORE SOUTHWARD THROUGH
THE TIDEWATER AND NE NC SO NO CHANGES NECESSARY TO GOING FORECAST.
LOW TEMPS WILL EVENTUALLY SETTLE INTO THE UPR 30S TO LOW 40S.
PREVIOUS DISCUSSION...
UPPER TROUGH OVER TX WILL CONTINUE TO MOVE EAST AND
SHARPEN ALONG THE GULF COAST TONIGHT. THIS WILL RESULT IN A
BACKING OF THE MID AND UPPER FLOW...WHICH WILL ALLOW MOISTURE TO
SURGE BACK UP THE COAST LATER TONIGHT INTO SUNDAY MORNING. THERE
IS DECENT MODEL AGREEMENT ON AN ELONGATED LOW PRESSURE CENTER
FORMING (AND MOVING NE) OFF THE SOUTHEAST OVERNIGHT...BEFORE
DEPARTING OFF THE OUTER BANKS SUNDAY MORNING. HOWEVER...THERE IS
MORE DISAGREEMENT WITHIN THE MOISTURE FIELDS...BOTH AMOUNTS AND
HOW FAR INLAND RAIN INVADES. AT THIS TIME THE LEAST BULLISH IS THE
ECMWF...WHICH MAKES SENSE GIVEN THE AMOUNT OF CONVECTION FROM THE
FL PANHANDLE TO THE GA COAST. GIVEN THIS...THE HIGHEST POPS
(CATEGORICAL) ARE FORECAST OVER NE NC FROM THE CHOWAN RIVER EAST
AND OVER THE TIDEWATER AND LOWER VA EASTERN SHORE MAINLY LATE
TONIGHT INTO EARLY SUNDAY MORNING...WITH A SHARP DECLINE FROM S
CENTRAL VA TO THE LOWER MD EASTERN SHORE. GENERALLY AN ADDITIONAL
0.3 TO 0.6 IN OF RAIN COULD FALL WHERE CATEGORICAL POPS ARE
FORECAST. WHILE NOT ENOUGH OF A CHANCE TO INCLUDE IN THE FORECAST
GRIDS A FEW ICE PELLETS ARE POSSIBLE ALONG THE NORTHERN FRINGES OF
THE PRECIP AS IT INTERACTS WITH DRIER AIR TO THE WEST.
A FEW RAIN SHOWERS ARE POSSIBLE AS THE UPPER TROUGH AXIS SWINGS
THROUGH SUNDAY AFTERNOON...BUT OTHERWISE A WEST TO EAST IMPROVING
TREND IS EXPECTED. TEMPERATURES WILL BE CHALLENGING ESPECIALLY
DURING THE DAY SUNDAY. READINGS ARE EXPECTED TO STEADILY DROP OFF
OVERNIGHT AND REACH MINIMA FROM THE UPPER 30S NW...TO LOW 40S SE
TOWARD MORNING. AT THIS POINT LOW 50S ARE FORECAST FOR HIGHS WEST OF
I-95 SUNDAY...WITH MID 40S CLOSER TO THE COAST WITH LOW CLOUDS AND
RAIN EXPECTED. OF NOTE...TEMPERATURES ARE MORE REFLECTIVE OF THE MAV
NUMBERS (ALBEIT A FEW DEGREES COOLER) THAN THE NAM-BASED
GUIDANCE...WHICH APPARENTLY OVER-EMPHASIZES DYNAMICAL COOLING ALONG
THE COAST AND TRIES TO MAKE TEMPERATURES COOL ENOUGH TO SUPPORT A
CHANGE-OVER TO SNOW ALONG THE COAST. THAT SOLUTION WAS DISREGARDED
FOR THIS FORECAST.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
THE PATTERN REMAINS ACTIVE EARLY NEXT WEEK AS A VIGOROUS MID-LEVEL
TROUGH DIVES ACROSS THE MIDWEST AND OHIO VALLEY SUNDAY NIGHT. THIS
TROUGH (CLIPPER SYSTEM) CROSSES THE MID ATLANTIC MONDAY...WITH THE
ASSOCIATED SURFACE LOW TRACKING ACROSS THE VA/NC BORDER. THE THERMAL
PROFILE ALOFT CRASHES WITH THIS SYSTEM...1000-500MB THICKNESS VALUES
AROUND 5250M AND LOW-LEVEL THICKNESS VALUES RANGE FROM AROUND 1290M
N...TO 1310 M S. THIS WOULD SUPPORT THE POSSIBILITY OF A PERIOD OF
LIGHT SNOW (GENERALLY IF IT OCCURS EARLY ENOUGH IN THE DAY). AT
THIS POINT THE PRECIP TYPE GENERALLY REFLECTS SREF
PROBABILITIES...AND THE CHANCE OF MEASURABLE LIQUID WAS CAPPED AT 30
PERCENT. CONFIDENCE IS MODERATE ON THE IS SYSTEM AS THE GFS AND
ECMWF HAVE BEEN SOMEWHAT CONSISTENT AND THE NAM HAS SEEMED TO TREND
THIS DIRECTION. NEVERTHELESS...CLIPPER SYSTEMS CAN BE FICKLE. HIGH
TEMPERATURES MONDAY WERE COOLED A FEW DEGREES INTO THE MID/UPPER 40S.
HIGH PRESSURE BUILDS IN FROM THE WEST MONDAY NIGHT AND BECOMES
CENTERED OVER THE MID ATLANTIC TUESDAY BRINGING COOL PLEASANT
CONDITIONS. LOW TEMPERATURES TUESDAY MORNING SHOULD RANGE FROM THE
MID 20S TO LOW 30S...FOLLOWED BY HIGHS IN THE MID 40S EASTERN
SHORE...TO LOW 50S PIEDMONT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL BE CENTERED OVER THE MID ATLANTIC WEDNESDAY
DRIFTING SLOWLY EAST WEDNESDAY NIGHT AND THURSDAY. TEMPERATURES
WILL REBOUND INTO THE LOW TO MID 60S WITH LOWS MODERATING IN THE
LOW TO MID 40S WEDNESDAY NIGHT WITH DEEPENING SOUTHERLY FLOW.
SOUTHERLY FLOW INCREASES THURSDAY AS THE REGION BECOMES SQUEEZED
BETWEEN THE HIGH MOVING OFFSHORE AND THE NEXT APPROACHING STORM
SYSTEM. EVEN WITH SOME INCREASING HIGH CLOUDS THURSDAY
TEMPERATURES WILL WARM INTO THE UPPER 60 TO LOWER 70S.
CHANCES FOR PRECIPITATION WILL HOLD OFF UNTIL LATE FRIDAY OR
SATURDAY. THERE IS MUCH DISAGREEMENT IN THE MODELS REGARDING THE
FORECAST FOR FRIDAY AND SATURDAY. THE ECMWF HAS BEEN MUCH MORE
AMPLIFIED WITH THE NEXT UPPER TROUGH THAN THE GFS AND CANADIAN. IN
RESPONSE THE ECMWF DEVELOPED A SURFACE WAVE OVER THE SOUTHEAST
BRINGING IT INTO THE MID ATLANTIC FRIDAY NIGHT. THE GFS IS WEAKER
AND SLOWER WITH THE SYSTEM HOLDING OFF THE RAIN UNTIL SATURDAY.
THERE WILL BE DISTURBED WEATHER IN THE EXTENDED WITH GOOD CHANCES
FOR PRECIPITATION AT SOME POINT FROM LATE FRIDAY THROUGH SATURDAY.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
THE SURFACE COLD FRONT HAS SLIDE OFF THE COAST...NOW HAVING
STALLED OVER THE ALBEMARLE SOUND...AS A RESULT OF APPROACHING
TROUGH AND SHORTWAVE ENERGY THAT IS DIGGING ACROSS TX AND THE
LOWER MS VALLEY. AS THIS ENERGY SLIDES EAST...EXPECT TO SEE A WAVE
OF LOW PRESSURE FORM ALONG THE BOUNDARY OVER SERN SC AND THEN
SLIDE NE OFF THE NC COAST SUNDAY MORNING. THIS WILL SPREAD MORE
MOISTURE AND RAIN NORTHWARD ALONG THE COASTAL AREAS. COMBINE THIS
WITH A DEVELOPING NERLY FLOW AS A RESULT OF LOW AND EXPECT TO SEE
IFR TO LIFR CONDITIONS ALONG COAST WITH THE RAIN AND LOWER
CEILINGS. THIS SHOULD IMPACT ORF AND ECG. FOR THE OTHER
SITES...THERE IS STILL SOME QUESTION AS TO HOW FAR NORTH AND WEST
THE LOWER CLOUDS AND PRECIP GO. FOR NOW HAVE ALLOWED FOR SOME MVFR
CONDITIONS FOR PHF AND SBY...BUT DO NOT EXPECT THE TROUGH TO
BECOME NEGATIVELY TILT SO DO NOT THINK ENOUGH MOISTURE GETS PULLED
BACK TO RIC.
ONCE THE FRONT IS OFF THE COAST AND THE SURFACE LOW PULLS WEST
AFTER 18Z...SHOULD SEE DRIER AIR AND WESTERLY FLOW CLEAR THE SKY
AND RETURN CONDITIONS TO VFR BY 00Z.
A CLIPPER TYPE WAVE WILL SLIDE ACROSS THE AREA ON MONDAY AND COULD
PRODUCE SOME MVFR CONDITIONS WITHIN SOME SCATTERED SHOWERS
OTHERWISE THROUGH TUESDAY THROUGH THURSDAY SHOULD SEE
PREDOMINATELY VFR CONDITIONS.
&&
.MARINE...
HAVE DROPPED THE SCA FOR THE SOUTHERN 3 COASTAL ZONES AS THE OBS
AT BUOY 40099 AND 40100 BOTH SHOW SEAS DOWN TO 4 FT AS THE WINDS
CONTINUE TO RELAX WITH THE STALLED FRONT. HAVE LEFT THE SCA IN
EFFECT FURTHER NORTH AS SEAS AT BUOY 40009 REMAIN AROUND 5 FT. BUT
WITH THE SLACKING OF THE WINDS...EXPECT TO SEE THE SEAS HERE
CONTINUE TO DECREASE.
PREV DISCUSSION... SCA WILL ONLY BE IN EFFECT FOR THE COASTAL
WATERS WITH THE AFTERNOON FORECAST AND MAINLY FOR SEAS OF 4 TO 6
FEET. WINDS HAVE DECREASED TO 15 KT HOWEVER THE CAPE CHARLES BUOYS
AND THE BUOYS OFFSHORE OF DUCK NC ARE REPORTING SEAS OF 5 FEET.
SEAS ARE AROUND 6 FEET FURTHER NORTH. SEAS WILL SLOWLY DECREASE
THIS EVENING AND OVERNIGHT FALLING BELOW SCA.
THE COLD FRONT HAS BEEN SLOW TO PUSH EAST BUT IT WILL REACH THE BAY
AND COASTAL WATERS SHORTLY AFTER SUNSET. WINDS WITH THE FRONT ARE
NOT STRONG AND WILL BECOME NW AROUND 10 TO 15 KT TONIGHT. OVER
THE BAY AND SOUND...WINDS SHOULD DIMINISH OVERNIGHT A FEW HOURS
AFTER THE FRONTAL PASSAGE.
LOW PRESSURE MOVES AWAY FROM THE COAST SUNDAY AS HIGH PRESSURE
BUILDS IN THE FROM THE WEST. THIS WILL KEEP WINDS NW AROUND 15
KT. WINDS BECOME SLY AGAIN SUNDAY NIGHT INTO EARLY MONDAY AS A LOW
PRESSURE SYSTEM MOVES EAST ACROSS THE REGION. WINDS INCREASE ONCE
AGAIN LATE MONDAY BECOMING NW AS THE SURFACE LOW DEEPENS ALONG
THE COAST BEHIND AN UPPER LEVEL SHORT WAVE. SCA MAY BE NEEDED
MONDAY AFTERNOON THROUGH PART OF TUESDAY.
HIGH PRESSURE SETTLES IN FROM THE WEST LATE TUESDAY THROUGH
WEDNESDAY MOVING SLOWLY OFFSHORE THURSDAY. THIS WILL BRING CALMER
CONDITIONS TO THE BAY AND COASTAL WATERS MID WEEK. LOOKING AHEAD
TO THE END OF THE WEEK MODELS ARE IN DISAGREEMENT WITH THE NEXT
STORM SYSTEM WHICH SHOULD IMPACT THE REGION LATE FRIDAY INTO
EARLY SATURDAY WITH POSSIBLE SCA CONDITIONS.
&&
.HYDROLOGY...
MINOR FLOODING IS OCCURRING AT THE WESTHAM GAGE AT RICHMOND.
THE RIVER IS CRESTING THIS AFTERNOON ONE FOOT ABOVE FLOOD STAGE
AND WILL REMAIN IN MINOR FLOOD THROUGH SUNDAY MORNING.
&&
.CLIMATE...
SEE WBCPNSAKQ FOR DETAILS ON METEOROLOGICAL WINTER (DEC-FEB) AT
RICHMOND AND NORFOLK (BOTH BEING 4TH WARMEST ON RECORD).
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR ANZ650-652.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ/JDM
SHORT TERM...AJZ
LONG TERM...JAO
AVIATION...ESS
MARINE...ESS/JAO
HYDROLOGY...AKQ
CLIMATE...AKQ
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
345 PM EST FRI MAR 2 2012
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL BRING SHOWERS AND THUNDERSTORMS
THIS EVENING WITH STRONG TO SEVERE THUNDERSTORMS POSSIBLE TONIGHT.
IN THE WAKE OF THE FRONT, COLDER AIR WILL MOVE INTO THE AREA
WITH GUSTY WINDS EXPECTED ON SATURDAY AND SNOW SHOWERS POSSIBLE ON
SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A SOUTHWESTERLY FLOW
ACROSS THE UPPER OHIO VALLEY. AT THE SURFACE, A 990MB SURFACE LOW
IS CENTERED IN INDIANA WITH A WARM FRONT EXTENDING SOUTHEASTWARD
ACROSS KENTUCKY AND WEST VIRGINIA.
THIS EVENING...THE WARM FRONT WILL APPROACH THE AREA FROM THE
SOUTHWEST AHEAD OF A COLD FRONT. ELEVATED INSTABILITY (MUCAPE
AROUND 500 J/KG) SLIDING INTO THE AREA WILL ALLOW FOR SHOWERS
WITH THE CHANCE OF THUNDERSTORMS. DESPITE STRONG SHEAR, LIMITED
INSTABILITY AND DRY LOW-LEVELS WILL PREVENT THE SEVERE THREAT
INITIALLY.
TONIGHT...THE STRENGTHENING SURFACE LOW WILL MOVE INTO THE GREAT
LAKES, SWINGING A COLD FRONT ACROSS THE UPPER OHIO VALLEY. DESPITE
MINIMAL SBCAPE, 50-60KT 850MB LOW-LEVEL JET PUSHING INTO THE AREA
SUPPORTS THE POSSIBLE DEVELOPMENT OF CONVECTION INTO A SQUALL
LINE JUST AHEAD OF THE COLD FRONT. IF THIS DEVELOPS, THIS WILL
BRING THE PRIMARY THREAT OF DAMAGING WINDS TO THE AREA. THE
NAM/SREF ARE INDICATING 0-1KM SHEAR OF 40KTS SO WITH THIS IN
CONSIDERATION AND 5-10% SPC TORNADO THREAT HAVE MENTION OF
ISOLATED TORNADOES IN HWO FOR PORTIONS OF EASTERN OHIO. SHOWERS
AND THUNDERSTORMS WILL COME TO AN END AS THE FRONT PUSHES EAST OF
THE RIDGES NEAR DAWN ON THURSDAY. AS THE PRESSURE GRADIENT
TIGHTENS, SYNOPTIC WINDS WILL INCREASE, WITH GUSTS UP TO 40 MPH
OVERNIGHT. OVERNIGHT LOWS ARE NEAR A MAV/MET BLEND, COOLING TO A
FEW DEGREES BELOW NORMAL AS COLD AIR ADVECTS IN BEHIND THE FRONT.
WITH PWATS INCREASING TO AROUND AN INCH (2 STANDARD DEVIATIONS ABOVE
SEASONAL NORMAL) AND 3HR FFG OF 1.0-1.5 INCHES FROM PREVIOUS
RAINFALL ON WEDNESDAY, THERE IS A FLASH FLOOD THREAT IN
LOCALIZED THUNDERSTORMS FOR PORTIONS OF NORTH-CENTRAL WV, EASTERN
OHIO, EXTREME SOUTHWEST PA, AND WESTERN MD. THUS, A FLASH FLOOD
WATCH REMAINS THESE AREAS.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
THERE IS OPERATIONAL MODEL AGREEMENT THAT THE SURFACE LOW WILL
CONTINUE TO PULL FURTHER NORTHEAST OF THE AREA WITH A DEEP LAYER OF
DRY AIR BUILD INTO THE REGION ON SATURDAY. A TIGHTENED PRESSURE GRADIENT
WILL REMAIN ACROSS THE UPPER OHIO VALLEY. THIS WILL ALLOW FOR
GUSTY WINDS TO INCREASE WITH DIURNAL MIXING BY LATE MORNING INTO
THE AFTERNOON. BUFKIT SUPPORTS WINDS GUSTING TO 30 TO 40 MPH AND
AT THIS TIME GUSTS ARE FORECAST TO BE JUST BELOW WIND ADVISORY
CRITERIA.
SATURDAY NIGHT...THE LOW-LEVEL FLOW WILL BACK TO WEST-NORTHWESTERLY
WITH COLD AIR ADVECTION SERVING TO INITIATE SCATTERED SNOW
SHOWERS. BEST CHANCE WILL BE ALONG THE I-80 CORRIDOR AND EASTERN
RIDGES WITH LOW CHANCE POPS ELSEWHERE. THE PRESSURE GRADIENT WILL
LOOSEN AND ALLOW FOR WIND GUSTS TO DECREASE.
UPPER LEVEL SHORTWAVE WILL MOVE ACROSS THE EASTERN GREAT LAKES
SUNDAY. 850MB TEMPERATURES WILL BE COLD ENOUGH TO ALLOW FOR AT LEAST
SOME LAKE ENHANCEMENT...IF NOT LAKE EFFECT SHOWERS. WINDS MAY NOT
HAVE ENOUGH OF A NORTHERLY COMPONENT ON SUNDAY TO TAP INTO MUCH LAKE
ERIE MOISTURE OUTSIDE OF THE RIDGES AND I-80 CORRIDOR...AND THIS MAY
LIMIT SNOWFALL TOTALS. BETTER CHANCE FOR SNOWFALL MAY OCCUR SUNDAY
NIGHT AS 850MB TEMPS CONTINUE TO DECREASE AND WINDS BECOME MORE
NORTHWESTERLY. PRECIPITATION SHOULD DIMINISH ON MONDAY WITH UPPER
LEVEL SUPPORT MOVING OFF TO THE EAST. TEMPERATURES THROUGH THIS
PERIOD WILL BE 5-10 DEGREES BELOW NORMAL.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL DOMINATE THE EAST COAST TUESDAY AND
WEDNESDAY...KEEPING CONDITIONS DRY. LOW PRESSURE ACROSS CANADA WILL
SLOWLY DRAG A COLD FRONT ACROSS THE EASTERN UNITED STATES. USUAL
DIFFERENCES IN MODEL TIMING FOR THE EXTENDED FORECAST...BUT MODELS
ARE IN BETTER AGREEMENT THAN NORMAL. FRONT SHOULD ARRIVE DURING THE
DAY THURSDAY...WITH RAIN CONTINUING INTO FRIDAY. EXPECT NEAR
CLIMATOLOGICAL TEMPS ON TUESDAY...WITH WELL ABOVE NORMAL TEMPS FOR
WEDNESDAY AND THURSDAY...AND SLIGHTLY COOLER BEHIND THE COLD FRONT
ON FRIDAY.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
RAIN ASSOCIATED WITH A WARM FRONT WILL OVERSPREAD TERMINALS FROM
SOUTH TO NORTH DURING THE MID TO LATE AFTERNOON HOURS. AT 18Z TAF
ISSUANCE...THERE WAS LITTLE ORGANIZED CONVECTION OCCURRING WITH THE
FRONT...SO HAVE ONLY GONE WITH A CB MENTION AT THIS TIME. A
THUNDERSTORM CANNOT BE RULED OUT WITH THE WARM FRONT. SOME LOW LEVEL
WIND SHEAR COULD OCCUR DURING THIS TIME WITH SURFACE WINDS OUT OF
THE S-SE AND WINDS ALOFT OUT OF THE S-SW...BUT HAVE CHOSEN TO
HIGHLIGHT WIND GUSTS AT THIS TIME. THERE COULD BE A SLIGHT GAP IN
RAINFALL BETWEEN THE WARM FRONT DURING THE LATE AFTERNOON AND THE
COLD FRONT ARRIVING THIS EVENING FROM THE WEST. THE COLD FRONT WILL
BE QUITE STRONG...AND THERE IS THE POSSIBILITY FOR HAIL AND 50KT
WINDS IN THUNDERSTORMS AS THE FRONT PASSES. DID NOT HAVE ENOUGH
CONFIDENCE IN TIMING TO SPECIFICALLY INCLUDE TEMPO TSRA IN TAFS AT
THIS TIME.
ONCE COLD FRONT PASSES BETWEEN 03-06Z...CLOUDS WILL BEGIN TO SCATTER
OUT...BUT GUSTS WILL REMAIN 25-30 KTS OUT OF THE SOUTHWEST.
SUSTAINED WINDS WILL DROP SLIGHTLY OVERNIGHT...BUT BY LATE MORNING
MANY SITES WILL APPROACH WESTERLY 20G30KT...WITH HIGHER VALUES TO
THE NORTH. ANOTHER LINE OF CLOUDS WILL APPROACH...BUT CONDITIONS
WILL REMAIN VFR WITH NO PRECIPITATION.
OUTLOOK...SATURDAY AFTERNOON THROUGH WEDNESDAY...
CONDITIONS WILL REMAIN VFR SATURDAY AFTERNOON INTO SATURDAY EVENING
IN ADVANCE OF AN UPPER LEVEL SYSTEM MOVING ACROSS THE GREAT LAKES.
EXPECT RESTRICTIONS IN SNOW SHOWERS SATURDAY NIGHT INTO SUNDAY
NIGHT. TERMINALS SOUTH OF PITTSBURGH COULD REMAIN UNDER RESTRICTIONS
IN SNOW SHOWERS MONDAY. HIGH PRESSURE WILL BRING VFR CONDITIONS FOR
MONDAY NIGHT THROUGH WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MDZ001.
OH...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR OHZ068-069.
PA...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ031-073>076.
WV...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR WVZ004-012-021>023-
041.
&&
$$
AREA FORECAST DISCUSSION...RESENT
NWS PITTSBURGH PA
204 PM EST FRI MAR 2 2012
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL BRING SHOWERS AND THUNDERSTORMS
THIS AFTERNOON WITH STRONG TO SEVERE THUNDERSTORMS POSSIBLE
TONIGHT. IN THE WAKE OF THE FRONT, COLDER AIR WILL MOVE INTO THE
AREA WITH GUSTY WINDS EXPECTED ON SATURDAY AND SNOW SHOWERS
POSSIBLE ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN EARLY AFTERNOON ENHANCED SHORT TERM FORECAST HAS BEEN ISSUED TO
PIN DOWN TIMING ON SHOWERS AND POSSIBLE THUNDERSTORMS EARLY AND
MORE ORGANIZED CONVECTION TONIGHT AS IT CROSSES THE AREA AHEAD OF
A COLD FRONT.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A SOUTHWESTERLY FLOW
ACROSS THE UPPER OHIO VALLEY AHEAD OF A CLOSED LOW ACROSS THE
NORTHERN PLAINS. AT THE SURFACE, A 992MB SURFACE LOW IS CENTERED
ACROSS SOUTHERN ILLINOIS WITH A WARM FRONT EXTENDING EASTWARD
ACROSS KENTUCKY AND WEST VIRGINIA.
THIS AFTERNOON...THE WARM FRONT WILL PUSH NORTHEAST TOWARD THE
AREA, WITH ELEVATED INSTABILITY (MUCAPE AROUND 500 J/KG) SLIDING
INTO EASTERN OHIO AND NORTH-CENTRAL WV. THIS WILL ALLOW FOR
SHOWERS WITH THE CHANCE OF THUNDERSTORMS TO PUSH INTO THE AREA.
DESPITE STRONG SHEAR, LIMITED INSTABILITY AND DRY LOW-LEVELS WILL
PREVENT SEVERE THREAT EARLY.
TONIGHT...THE STRENGTHENING SURFACE LOW WILL MOVE INTO THE GREAT
LAKES, SWINGING A COLD FRONT ACROSS THE UPPER OHIO VALLEY. WITH
SBCAPE AROUND 500 J/KG AND A 50KT 850MB LOW-LEVEL JET, 4KM WRF-
NMM SUPPORTS THE POSSIBLE DEVELOPMENT OF A SQUALL LINE JUST AHEAD
OF THE COLD FRONT PUSHING ACROSS THE AREA. THIS WILL BRING THE
PRIMARY THREAT OF DAMAGING WINDS TO THE AREA. THE NAM/SREF ARE
INDICATING 0-1KM SHEAR OF 40KTS AND 0-1 SRH AT 300-500, SO WITH
THIS IN CONSIDERATION AND 5-10% SPC TORNADO THREAT HAVE MENTION OF
ISOLATED TORNADOES IN HWO FOR PORTIONS OF EASTERN OHIO. SHOWERS AND
THUNDERSTORMS WILL COME TO AN END AS THE FRONT PUSHES EAST OF THE
RIDGES NEAR DAWN ON THURSDAY. OVERNIGHT LOWS ARE NEAR A MAV/MET
BLEND, COOLING TO A FEW DEGREES BELOW NORMAL AS COLD AIR ADVECTS
IN BEHIND THE FRONT.
WITH PWATS INCREASING TO AROUND AN INCH (2 STANDARD DEVIATIONS ABOVE
SEASONAL NORMAL) AND 3HR FFG OF 1.0-1.5 INCHES FROM PREVIOUS
RAINFALL ON WEDNESDAY, BELIEVE THERE WILL BE A FLASH FLOOD THREAT
IN LOCALIZED THUNDERSTORMS FOR PORTIONS OF NORTH-CENTRAL WV,
EASTERN OHIO, EXTREME SOUTHWEST PA, AND WESTERN MD. THUS, A FLASH
FLOOD WATCH REMAINS FOR PORTIONS OF THE AREA.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
SREF MODEL OUTPUT SHOWS WINDS CAN STILL GUST TO 35-40 MPH DAYTIME
SATURDAY. COLD POOL STRATOCUMULUS MAY HAVE ENOUGH BREAKS FOR SOME
SUNSHINE BY AFTERNOON. RECENT GFS AND NAM MOS SHOW FORECASTED HIGH
TEMPERATURES TO BE 10 DEGREES COLDER THAN FRIDAY, BUT TO BE NEAR
SEASONABLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS A SECONDARY
CANADIAN COLD FRONT WILL PROVIDE AN ADDITIONAL COLD SHOT FOR LATE
SATURDAY NIGHT AND SUNDAY, WHICH WILL BE ACCOMPANIED BY LAKE
ENHANCED SNOW SHOWERS INTO SUNDAY NIGHT. COLD TEMPERATURES WILL
PERSIST MONDAY WITH PERHAPS LINGERING FLURRIES.
HIGH PRESSURE SHOULD PROMOTE DRY CONDITIONS AND MODERATING
TEMPERATURES TUESDAY INTO THURSDAY, AS SHOWN BY GFS MOS, NAEFS
MEDIAN VALUES, AND OPERATIONAL ECMWF MODEL OUTPUT.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
RAIN ASSOCIATED WITH A WARM FRONT WILL OVERSPREAD TERMINALS FROM
SOUTH TO NORTH DURING THE MID TO LATE AFTERNOON HOURS. AT 18Z TAF
ISSUANCE...THERE WAS LITTLE ORGANIZED CONVECTION OCCURRING WITH THE
FRONT...SO HAVE ONLY GONE WITH A CB MENTION AT THIS TIME. A
THUNDERSTORM CANNOT BE RULED OUT WITH THE WARM FRONT. SOME LOW LEVEL
WIND SHEAR COULD OCCUR DURING THIS TIME WITH SURFACE WINDS OUT OF
THE S-SE AND WINDS ALOFT OUT OF THE S-SW...BUT HAVE CHOSEN TO
HIGHLIGHT WIND GUSTS AT THIS TIME. THERE COULD BE A SLIGHT GAP IN
RAINFALL BETWEEN THE WARM FRONT DURING THE LATE AFTERNOON AND THE
COLD FRONT ARRIVING THIS EVENING FROM THE WEST. THE COLD FRONT WILL
BE QUITE STRONG...AND THERE IS THE POSSIBILITY FOR HAIL AND 50KT
WINDS IN THUNDERSTORMS AS THE FRONT PASSES. DID NOT HAVE ENOUGH
CONFIDENCE IN TIMING TO SPECIFICALLY INCLUDE TEMPO TSRA IN TAFS AT
THIS TIME.
ONCE COLD FRONT PASSES BETWEEN 03-06Z...CLOUDS WILL BEGIN TO SCATTER
OUT...BUT GUSTS WILL REMAIN 25-30 KTS OUT OF THE SOUTHWEST.
SUSTAINED WINDS WILL DROP SLIGHTLY OVERNIGHT...BUT BY LATE MORNING
MANY SITES WILL APPROACH WESTERLY 20G30KT...WITH HIGHER VALUES TO
THE NORTH. ANOTHER LINE OF CLOUDS WILL APPROACH...BUT CONDITIONS
WILL REMAIN VFR WITH NO PRECIPITATION.
OUTLOOK...SATURDAY AFTERNOON THROUGH WEDNESDAY...
CONDITIONS WILL REMAIN VFR SATURDAY AFTERNOON INTO SATURDAY EVENING
IN ADVANCE OF AN UPPER LEVEL SYSTEM MOVING ACROSS THE GREAT LAKES.
EXPECT RESTRICTIONS IN SNOW SHOWERS SATURDAY NIGHT INTO SUNDAY
NIGHT. TERMINALS SOUTH OF PITTSBURGH COULD REMAIN UNDER RESTRICTIONS
IN SNOW SHOWERS MONDAY. HIGH PRESSURE WILL BRING VFR CONDITIONS FOR
MONDAY NIGHT THROUGH WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MDZ001.
OH...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR OHZ068-069.
PA...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ031-073>076.
WV...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR WVZ004-012-021>023-
041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
201 PM EST FRI MAR 2 2012
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL BRING SHOWERS AND THUNDERSTORMS
THIS AFTERNOON WITH STRONG TO SEVERE THUNDERSTORMS POSSIBLE
TONIGHT. IN THE WAKE OF THE FRONT, COLDER AIR WILL MOVE INTO THE
AREA WITH GUSTY WINDS EXPECTED ON SATURDAY AND SNOW SHOWERS
POSSIBLE ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN EARLY AFTERNOON ENHANCED SHORT TERM FORECAST HAS BEEN ISSUED TO
PIN DOWN TIMING ON SHOWERS AND POSSIBLE THUNDERSTORMS EARLY AND
MORE ORGANIZED CONVECTION TONIGHT AS IT CROSSES THE AREA AHEAD OF
A COLD FRONT.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A SOUTHWESTERLY FLOW
ACROSS THE UPPER OHIO VALLEY AHEAD OF A CLOSED LOW ACROSS THE
NORTHERN PLAINS. AT THE SURFACE, A 992MB SURFACE LOW IS CENTERED
ACROSS SOUTHERN ILLINOIS WITH A WARM FRONT EXTENDING EASTWARD
ACROSS KENTUCKY AND WEST VIRGINIA.
THIS AFTERNOON...THE WARM FRONT WILL PUSH NORTHEAST TOWARD THE
AREA, WITH ELEVATED INSTABILITY (MUCAPE AROUND 500 J/KG) SLIDING
INTO EASTERN OHIO AND NORTH-CENTRAL WV. THIS WILL ALLOW FOR
SHOWERS WITH THE CHANCE OF THUNDERSTORMS TO PUSH INTO THE AREA.
DESPITE STRONG SHEAR, LIMITED INSTABILITY AND DRY LOW-LEVELS WILL
PREVENT SEVERE THREAT EARLY.
TONIGHT...THE STRENGTHENING SURFACE LOW WILL MOVE INTO THE GREAT
LAKES, SWINGING A COLD FRONT ACROSS THE UPPER OHIO VALLEY. WITH
SBCAPE AROUND 500 J/KG AND A 50KT 850MB LOW-LEVEL JET, 4KM WRF-
NMM SUPPORTS THE POSSIBLE DEVELOPMENT OF A SQUALL LINE JUST AHEAD
OF THE COLD FRONT PUSHING ACROSS THE AREA. THIS WILL BRING THE
PRIMARY THREAT OF DAMAGING WINDS TO THE AREA. THE NAM/SREF ARE
INDICATING 0-1KM SHEAR OF 40KTS AND 0-1 SRH AT 300-500, SO WITH
THIS IN CONSIDERATION AND 5-10% SPC TORNADO THREAT HAVE MENTION OF
ISOLATED TORNADOES IN HWO FOR PORTIONS OF EASTERN OHIO. SHOWERS AND
THUNDERSTORMS WILL COME TO AN END AS THE FRONT PUSHES EAST OF THE
RIDGES NEAR DAWN ON THURSDAY. OVERNIGHT LOWS ARE NEAR A MAV/MET
BLEND, COOLING TO A FEW DEGREES BELOW NORMAL AS COLD AIR ADVECTS
IN BEHIND THE FRONT.
WITH PWATS INCREASING TO AROUND AN INCH (2 STANDARD DEVIATIONS ABOVE
SEASONAL NORMAL) AND 3HR FFG OF 1.0-1.5 INCHES FROM PREVIOUS
RAINFALL ON WEDNESDAY, BELIEVE THERE WILL BE A FLASH FLOOD THREAT
IN LOCALIZED THUNDERSTORMS FOR PORTIONS OF NORTH-CENTRAL WV,
EASTERN OHIO, EXTREME SOUTHWEST PA, AND WESTERN MD. THUS, A FLASH
FLOOD WATCH REMAINS FOR PORTIONS OF THE AREA.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
SREF MODEL OUTPUT SHOWS WINDS CAN STILL GUST TO 35-40 MPH DAYTIME
SATURDAY. COLD POOL STRATOCUMULUS MAY HAVE ENOUGH BREAKS FOR SOME
SUNSHINE BY AFTERNOON. RECENT GFS AND NAM MOS SHOW FORECASTED HIGH
TEMPERATURES TO BE 10 DEGREES COLDER THAN FRIDAY, BUT TO BE NEAR
SEASONABLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS A SECONDARY
CANADIAN COLD FRONT WILL PROVIDE AN ADDITIONAL COLD SHOT FOR LATE
SATURDAY NIGHT AND SUNDAY, WHICH WILL BE ACCOMPANIED BY LAKE
ENHANCED SNOW SHOWERS INTO SUNDAY NIGHT. COLD TEMPERATURES WILL
PERSIST MONDAY WITH PERHAPS LINGERING FLURRIES.
HIGH PRESSURE SHOULD PROMOTE DRY CONDITIONS AND MODERATING
TEMPERATURES TUESDAY INTO THURSDAY, AS SHOWN BY GFS MOS, NAEFS
MEDIAN VALUES, AND OPERATIONAL ECMWF MODEL OUTPUT.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
RAIN ASSOCIATED WITH A WARM FRONT WILL OVERSPREAD TERMINALS FROM
SOUTH TO NORTH DURING THE MID TO LATE AFTERNOON HOURS. AT 18Z TAF
ISSUANCE...THERE WAS LITTLE ORGANIZED CONVECTION OCCURRING WITH THE
FRONT...SO HAVE ONLY GONE WITH A CB MENTION AT THIS TIME. A
THUNDERSTORM CANNOT BE RULED OUT WITH THE WARM FRONT. SOME LOW LEVEL
WIND SHEAR COULD OCCUR DURING THIS TIME WITH SURFACE WINDS OUT OF
THE S-SE AND WINDS ALOFT OUT OF THE S-SW...BUT HAVE CHOSEN TO
HIGHLIGHT WIND GUSTS AT THIS TIME. THERE COULD BE A SLIGHT GAP IN
RAINFALL BETWEEN THE WARM FRONT DURING THE LATE AFTERNOON AND THE
COLD FRONT ARRIVING THIS EVENING FROM THE WEST. THE COLD FRONT WILL
BE QUITE STRONG...AND THERE IS THE POSSIBILITY FOR HAIL AND 50KT
WINDS IN THUNDERSTORMS AS THE FRONT PASSES. DID NOT HAVE ENOUGH
CONFIDENCE IN TIMING TO SPECIFICALLY INCLUDE TEMPO TSRA IN TAFS AT
THIS TIME.
ONCE COLD FRONT PASSES BETWEEN 03-06Z...CLOUDS WILL BEGIN TO SCATTER
OUT...BUT GUSTS WILL REMAIN 25-30 KTS OUT OF THE SOUTHWEST.
SUSTAINED WINDS WILL DROP SLIGHTLY OVERNIGHT...BUT BY LATE MORNING
MANY SITES WILL APPROACH WESTERLY 20G30KT...WITH HIGHER VALUES TO
THE NORTH. ANOTHER LINE OF CLOUDS WILL APPROACH...BUT CONDITIONS
WILL REMAIN VFR WITH NO PRECIPITATION.
OUTLOOK...SATURDAY AFTERNOON THROUGH WEDNESDAY...
CONDITIONS WILL REMAIN VFR SATURDAY AFTERNOON INTO SATURDAY EVENING
IN ADVANCE OF AN UPPER LEVEL SYSTEM MOVING ACROSS THE GREAT LAKES.
EXPECT RESTRICTIONS IN SNOW SHOWERS SATURDAY NIGHT INTO SUNDAY
NIGHT. TERMINALS SOUTH OF PITTSBURGH COULD REMAIN UNDER RESTRICTIONS
IN SNOW SHOWERS MONDAY. HIGH PRESSURE WILL BRING VFR CONDITIONS FOR
MONDAY NIGHT THROUGH WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MDZ001.
OH...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR OHZ068-069.
PA...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ031-073>076.
WV...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR WVZ004-012-021>023-
041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
159 PM EST FRI MAR 2 2012
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL BRING SHOWERS AND THUNDERSTORMS
THIS AFTERNOON WITH STRONG TO SEVERE THUNDERSTORMS POSSIBLE
TONIGHT. IN THE WAKE OF THE FRONT, COLDER AIR WILL MOVE INTO THE
AREA WITH GUSTY WINDS EXPECTED ON SATURDAY AND SNOW SHOWERS
POSSIBLE ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN EARLY AFTERNOON ENHANCED SHORT TERM FORECAST HAS BEEN ISSUED TO
PIN DOWN TIMING ON SHOWERS AND POSSIBLE THUNDERSTORMS EARLY AND
MORE ORGANIZED CONVECTION TONIGHT AS IT CROSSES THE AREA AHEAD OF
A COLD FRONT.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A SOUTHWESTERLY FLOW
ACROSS THE UPPER OHIO VALLEY AHEAD OF A CLOSED LOW ACROSS THE
NORTHERN PLAINS. AT THE SURFACE, A 992MB SURFACE LOW IS CENTERED
ACROSS SOUTHERN ILLINOIS WITH A WARM FRONT EXTENDING EASTWARD
ACROSS KENTUCKY AND WEST VIRGINIA.
THIS AFTERNOON...THE WARM FRONT WILL PUSH NORTHEAST TOWARD THE
AREA, WITH ELEVATED INSTABILITY (MUCAPE AROUND 500 J/KG) SLIDING
INTO EASTERN OHIO AND NORTH-CENTRAL WV. THIS WILL ALLOW FOR
SHOWERS WITH THE CHANCE OF THUNDERSTORMS TO PUSH INTO THE AREA.
DESPITE STRONG SHEAR, LIMITED INSTABILITY AND DRY LOW-LEVELS WILL
PREVENT SEVERE THREAT EARLY.
TONIGHT...THE STRENGTHENING SURFACE LOW WILL MOVE INTO THE GREAT
LAKES, SWINGING A COLD FRONT ACROSS THE UPPER OHIO VALLEY. WITH
SBCAPE AROUND 500 J/KG AND A 50KT 850MB LOW-LEVEL JET, 4KM WRF-
NMM SUPPORTS THE POSSIBLE DEVELOPMENT OF A SQUALL LINE JUST AHEAD
OF THE COLD FRONT PUSHING ACROSS THE AREA. THIS WILL BRING THE
PRIMARY THREAT OF DAMAGING WINDS TO THE AREA. THE NAM/SREF ARE
INDICATING 0-1KM SHEAR OF 40KTS AND 0-1 SRH AT 300-500, SO WITH
THIS IN CONSIDERATION AND 5-10% SPC TORNADO THREAT HAVE MENTION OF
ISOLATED TORNADOES IN HWO FOR PORTIONS OF EASTERN OHIO. SHOWERS AND
THUNDERSTORMS WILL COME TO AN END AS THE FRONT PUSHES EAST OF THE
RIDGES NEAR DAWN ON THURSDAY. OVERNIGHT LOWS ARE NEAR A MAV/MET
BLEND, COOLING TO A FEW DEGREES BELOW NORMAL AS COLD AIR ADVECTS
IN BEHIND THE FRONT.
WITH PWATS INCREASING TO AROUND AN INCH (2 STANDARD DEVIATIONS ABOVE
SEASONAL NORMAL) AND 3HR FFG OF 1.0-1.5 INCHES FROM PREVIOUS
RAINFALL ON WEDNESDAY, BELIEVE THERE WILL BE A FLASH FLOOD THREAT
IN LOCALIZED THUNDERSTORMS FOR PORTIONS OF NORTH-CENTRAL WV,
EASTERN OHIO, EXTREME SOUTHWEST PA, AND WESTERN MD. THUS, A FLASH
FLOOD WATCH REMAINS FOR PORTIONS OF THE AREA.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
SREF MODEL OUTPUT SHOWS WINDS CAN STILL GUST TO 35-40 MPH DAYTIME
SATURDAY. COLD POOL STRATOCUMULUS MAY HAVE ENOUGH BREAKS FOR SOME
SUNSHINE BY AFTERNOON. RECENT GFS AND NAM MOS SHOW FORECASTED HIGH
TEMPERATURES TO BE 10 DEGREES COLDER THAN FRIDAY, BUT TO BE NEAR
SEASONABLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS A SECONDARY
CANADIAN COLD FRONT WILL PROVIDE AN ADDITIONAL COLD SHOT FOR LATE
SATURDAY NIGHT AND SUNDAY, WHICH WILL BE ACCOMPANIED BY LAKE
ENHANCED SNOW SHOWERS INTO SUNDAY NIGHT. COLD TEMPERATURES WILL
PERSIST MONDAY WITH PERHAPS LINGERING FLURRIES.
HIGH PRESSURE SHOULD PROMOTE DRY CONDITIONS AND MODERATING
TEMPERATURES TUESDAY INTO THURSDAY, AS SHOWN BY GFS MOS, NAEFS
MEDIAN VALUES, AND OPERATIONAL ECMWF MODEL OUTPUT.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
RAIN ASSOCIATED WITH A WARM FRONT WILL OVERSPREAD TERMINALS FROM
SOUTH TO NORTH DURING THE MID TO LATE AFTERNOON HOURS. AT 18Z TAF
ISSUANCE...THERE WAS LITTLE ORGANIZED CONVECTION OCCURRING WITH THE
FRONT...SO HAVE ONLY GONE WITH A CB MENTION AT THIS TIME. A
THUNDERSTORM CANNOT BE RULED OUT WITH THE WARM FRONT. SOME LOW LEVEL
WIND SHEAR COULD OCCUR DURING THIS TIME WITH SURFACE WINDS OUT OF
THE S-SE AND WINDS ALOFT OUT OF THE S-SW...BUT HAVE CHOSEN TO
HIGHLIGHT WIND GUSTS AT THIS TIME. THERE COULD BE A SLIGHT GAP IN
RAINFALL BETWEEN THE WARM FRONT DURING THE LATE AFTERNOON AND THE
COLD FRONT ARRIVING THIS EVENING FROM THE WEST. THE COLD FRONT WILL
BE QUITE STRONG...AND THERE IS THE POSSIBILITY FOR HAIL AND 50KT
WINDS IN THUNDERSTORMS AS THE FRONT PASSES. DID NOT HAVE ENOUGH
CONFIDENCE IN TIMING TO SPECIFICALLY INCLUDE TEMPO TSRA IN TAFS AT
THIS TIME.
ONCE COLD FRONT PASSES BETWEEN 03-06Z...CLOUDS WILL BEGIN TO SCATTER
OUT...BUT GUSTS WILL REMAIN 25-30 KTS OUT OF THE SOUTHWEST.
SUSTAINED WINDS WILL DROP SLIGHTLY OVERNIGHT...BUT BY LATE MORNING
MANY SITES WILL APPROACH WESTERLY 20G30KT...WITH HIGHER VALUES TO
THE NORTH. ANOTHER LINE OF CLOUDS WILL APPROACH...BUT CONDITIONS
WILL REMAIN VFR WITH NO PRECIPITATION.
OUTLOOK...SATURDAY AFTERNOON THROUGH WEDNESDAY...
CONDITIONS WILL REMAIN VFR SATURDAY AFTERNOON INTO SATURDAY EVENING
IN ADVANCE OF AN UPPER LEVEL SYSTEM MOVING ACROSS THE GREAT LAKES.
EXPECT RESTRICTIONS IN SNOW SHOWERS SATURDAY NIGHT INTO SUNDAY
NIGHT. TERMINALS SOUTH OF PITTSBURGH COULD REMAIN UNDER RESTRICTIONS
IN SNOW SHOWERS MONDAY. HIGH PRESSURE WILL BRING VFR CONDITIONS FOR
MONDAY NIGHT THROUGH WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MDZ001.
OH...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR OHZ068-069.
PA...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ031-073>076.
WV...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR WVZ004-012-021>023-
041.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1106 AM EST FRI MAR 2 2012
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL BRING SHOWERS AND THE
CHANCE OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO THE
EVENING. IN THE WAKE OF THE FRONT, COLDER AIR WILL MOVE INTO THE
AREA WITH GUSTY WINDS EXPECTED ON SATURDAY AND SNOW SHOWERS
POSSIBLE ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ADD
THUNDER AND INCREASE THE POPS TO BEGIN THE FORECAST.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A SOUTHWESTERLY FLOW
ACROSS THE UPPER OHIO VALLEY AHEAD OF A CLOSED LOW ACROSS THE
NORTHERN PLAINS. AT THE SURFACE, A 994MB SURFACE LOW IS LOCATED
ACROSS THE MISSOURI VALLEY WITH A WARM FRONT EXTENDING EASTWARD
ACROSS KENTUCKY. ELEVATED INSTABILITY HAS ALLOWED FOR CONVECTION TO
INITIATE NORTHWARD OF THE WARM FRONT ACROSS THE OHIO VALLEY.
THIS AFTERNOON...THE WARM FRONT WILL PUSH NORTHEAST TOWARD THE
AREA, WITH ELEVATED INSTABILITY (MUCAPE AROUND 500 J/KG) SLIDING
INTO EASTERN OHIO AND NORTH-CENTRAL WV. THIS WILL ALLOW FOR
SHOWERS WITH SCATTERED THUNDERSTORMS TO PUSH INTO THE AREA.
DESPITE STRONG SHEAR, BELIEVE LIMITED INSTABILITY WILL BE A
LIMITING FACTOR AND PREVENT THE SEVERE THREAT INITIALLY.
LATER THIS AFTERNOON INTO THE EVENING, BELIEVE THE SEVERE THREAT
WILL BEGIN IN EASTERN OHIO WITH BEST PUSH OF WARM AIR ADVECTION AS
THE WARM FRONT MOVES INTO THE AREA. AT THIS POINT, FORCING AND
STRONG SHEAR WILL MAY ALLOW FOR A FEW STRONG TO SEVERE
THUNDERSTORMS WITH A THREAT OF LARGE HAIL AND DAMAGING WINDS. THE
NAM/SREF ARE INDICATING 0-1KM SHEAR OF 40KTS AND 0-1SRH AT
300-500, SO WITH THIS IN CONSIDERATION AND 5% SPC TORNADO THREAT
HAVE ADDED MENTION OF ISOLATED TORNADOES INTO PORTIONS OF EASTERN
OHIO.
IN ADDITION, WITH PWATS INCREASING TO AROUND AN INCH (2SDS ABOVE
SEASONAL NORMAL AND 3HR FFG OF 1.0-1.5 INCHES FROM PREVIOUS
RAINFALL ON WEDNESDAY, BELIEVE THERE WILL BE A FLASH FLOOD THREAT
IN LOCALIZED THUNDERSTORMS FOR PORTIONS OF NORTH-CENTRAL WV,
EASTERN OHIO, EXTREME SOUTHWEST PA, AND WESTERN MD. THUS, A FLASH
FLOOD WATCH HAS BEEN ISSUED FOR PORTIONS THIS AREA.
TONIGHT...A STRENGTHENING SURFACE LOW WILL MOVE INTO THE GREAT
LAKES, SWINGING A COLD FRONT ACROSS THE UPPER OHIO VALLEY. WITH
SBCAPE AROUND 500 J/KG AND A 50KT 850MB LOW-LEVEL JET, 4KM WRF-
NMM SUPPORTS THE POSSIBLE DEVELOPMENT OF A SQUALL LINE JUST AHEAD
OF THE COLD FRONT PUSHING ACROSS THE AREA. THIS WILL BRING THE
PRIMARY THREAT OF DAMAGING WINDS TO THE AREA. SHOWERS AND
THUNDERSTORMS WILL COME TO AN END AS THE FRONT PUSHES EAST OF THE
RIDGES NEAR DAWN ON THURSDAY. OVERNIGHT LOWS ARE NEAR A MAV/MET
BLEND, COOLING TO A FEW DEGREES BELOW NORMAL AS COLD AIR ADVECTS
IN BEHIND THE FRONT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
SREF MODEL OUTPUT SHOWS WINDS CAN STILL GUST TO 35-40 MPH DAYTIME
SATURDAY. COLD POOL STRATOCUMULUS MAY HAVE ENOUGH BREAKS FOR SOME
SUNSHINE BY AFTERNOON. RECENT GFS AND NAM MOS SHOW FORECASTED HIGH
TEMPERATURES TO BE 10 DEGREES COLDER THAN FRIDAY, BUT TO BE NEAR
SEASONABLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS A SECONDARY
CANADIAN COLD FRONT WILL PROVIDE AN ADDITIONAL COLD SHOT FOR LATE
SATURDAY NIGHT AND SUNDAY, WHICH WILL BE ACCOMPANIED BY LAKE
ENHANCED SNOW SHOWERS INTO SUNDAY NIGHT. COLD TEMPERATURES WILL
PERSIST MONDAY WITH PERHAPS LINGERING FLURRIES.
HIGH PRESSURE SHOULD PROMOTE DRY CONDITIONS AND MODERATING
TEMPERATURES TUESDAY INTO THURSDAY, AS SHOWN BY GFS MOS, NAEFS
MEDIAN VALUES, AND OPERATIONAL ECMWF MODEL OUTPUT.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
EXPECT VFR THROUGH 20Z ACROSS THE UPPER OHIO VALLEY.
WITH THE STRONG LOW PRESSURE CENTER MOVING FROM OKLAHOMA THIS
MORNING NORTHEASTWARD TO MICHIGAN TONIGHT, EXPECT A WARM FRONTAL
MVFR RAIN BAND TO PASS THROUGH THE UPPER OHIO VALLEY 20Z-02Z,
FOLLOWED BY A COLD FRONTAL BAND OF MVFR SHOWERS AND SCATTERED
THUNDERSTORMS 01Z-05Z. SHORT IFR PERIODS WILL ALSO BE POSSIBLE.
PER SPC GUIDANCE, THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS
WITH THE MAIN AVIATION HAZARD STRONG WIND GUSTS AND SECONDARY HAZARD
HAIL MAINLY ALOFT.
THE POST COLD FRONTAL COOL DOWN WILL PROVIDE WIND GUSTS TO 30-35 KTS
LATE TONIGHT. THE PERIOD WILL BE DRY, BUT MAY STILL PROVIDE MVFR
STRATOCUMULUS CEILINGS.
OUTLOOK...SATURDAY THROUGH TUESDAY...
DURING DAYTIME SATURDAY, WINDS CAN STILL GUST OVER 30 KTS. REMAINING
STRATOCUMULUS CEILINGS SHOULD LIFT TO VFR LEVELS. A SECONDARY
CANADIAN COLD FRONT WILL PROVIDE SNOW SHOWERS AND RESTRICTIONS LATE
SATURDAY NIGHT AND SUNDAY. ENSUING MIDWEST HIGH PRESSURE WILL
RESTORE VFR FOR MONDAY AND TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MDZ001.
OH...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR OHZ068-069.
PA...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ031-073>076.
WV...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR WVZ004-012-021>023-
041.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
449 PM EST FRI MAR 2 2012
.SYNOPSIS...
ISSUED AT 445 PM EST FRI MAR 2 2012
LOW PRESSURE WILL RAPIDLY INTENSIFY TONIGHT AS IT PASSES THROUGH
LOWER MICHIGAN. STRONG... POSSIBLY DAMAGING... WINDS ARE EXPECTED
AS THE LOW PASSES BY.
ALSO ACCOMPANYING THE LOW PRESSURE SYSTEM WILL BE AN AREA OF
HEAVY SNOW ACROSS NORTHERN LOWER MICHIGAN. ELSEWHERE RAIN AND
SCATTERED THUNDERSTORMS ARE EXPECTED.
SCATTERED SNOW SHOWERS WILL LINGER SATURDAY AND SUNDAY IN THE
COLD AIR ON THE BACK SIDE OF THE DEPARTING SYSTEM.
A WARM UP IS ON THE WAY FOR THE AREA FOR THE FIRST HALF OF THE
WORK WEEK. 40S TO 50S WILL BE POSSIBLE BY WEDNESDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 445 PM EST FRI MAR 2 2012
SFC LOW TO TRACK ACROSS KALAMAZOO TO SAGINAW BAY THIS EVENING
WHILE RAPIDLY DEEPENING. LATEST MSAS SHOWS IT AT PRESENTLY 990MB
IN WRN INDIANA AND THE HRR RUC HAS IT 970MB AT 07Z OVER SAGINAW
BAY. AS THE LOW PASSES BY LATER THIS EVENING LOOK FOR WIND GUSTS
APPROACHING OR EXCEEDING WARNING CRITERIA OF 50 KNOTS. THIS IS
SUPPORTED IN FCST SNDGS AND HRR WIND GUST PROGS... WITH BEST
THREAT OVER THE SRN FCST AREA. NOT AS CERTAIN NORTH OF ST JOHNS.
BEST WINDOW FOR SVR GUSTS IS ROUGHLY 04Z-08Z... BUT WILL HAVE
BUFFER ON EITHER SIDE FOR THE WARNING TIME.
AS FAR AS THE HEAVY SNOW THREAT... DID NOT STRAY TOO MUCH FROM
PREVIOUS FCST. CONVECTION/LIGHTNING STRIKES NOW BEING OBSERVED
ACROSS NRN IL IN THE SRN EDGE OF DEVELOPING DEFORMATION
ZONE/TROWAL. THIS FEATURE WILL ONLY INTENSIFY THIS EVENING... THEN
IT/S JUST A MATTER OF CHANGING PCPN OVER TO SNOW IN THE WARNING
AREA. IT LOOKS PRETTY WARM THROUGH 00Z... THEN RAPID DYNAMICAL
COOLING SHOULD FORCE CHANGEOVER TO HEAVY SNOW WITH ONE TO TWO INCH
PER HOUR RATES STILL LIKELY TONIGHT.
BECAUSE OF THE MARGINAL SFC TEMPS IN THE MID 30S ACROSS THE
WARNING AREA... ELEVATION WILL PROBABLY PLAY A CRITICAL ROLE IN
WHEN RAIN CHANGES TO SNOW AND ALSO IN STORM TOTAL SNOW
ACCUMULATION. HAVE ADDED IN MECOSTA COUNTY INTO THE WARNING AS
HIGHER ELEVATIONS THERE MAY RESULT IN AMOUNTS APPROACHING SIX
INCHES. HOWEVER EVEN WHERE ACCUMS DO NOT REACH SIX INCHES THE
WARNING IS PROBABLY STILL WELL JUSTIFIED DUE TO THE COMBO OF THE
HIGH WINDS AND THE SNOW.
HEAVY SYNOPTIC SNOW IN THE DEFORMATION ZONE SHOULD BE WINDING DOWN
TOWARD 12Z SAT... WITH A TRANSITION TO LAKE EFFECT/ENHANCED SNOWS.
ANOTHER 2 TO 4 INCHES IS POSSIBLE ON SATURDAY IN THE WARNING
AREA... AND ALSO FARTHER SOUTH INCLUDING THE GRR/BIV AREAS. AFTER
THE HIGH WIND WARNING EXPIRES... A WINTER WEATHER ADVISORY MAY BE
NEEDED SATURDAY FOR KENT/OTTAWA SOUTH... WHILE THE WARNING
CONTINUES IN THE NORTH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 213 PM EST FRI MAR 2 2012
THERE ARE TWO SYSTEMS WE ARE WATCHING IN THE LONG TERM PERIOD. THE
FIRST IS THE LAKE ENHANCED SNOW SHOWERS WITH THE ARCTIC FRONT
COMING THROUGH EARLY SUNDAY MORNING THEN THE SYSTEM IN THE
WEDNESDAY TIME FRAME.
THERE IS A TRAILING NORTHERN STREAM SYSTEM THAT ROTATES ACROSS
LOWER MICHIGAN SUNDAY NIGHT ON THE NORTHERN STREAM. THIS BRINGS TO
COLDEST AIR THIS AREA HAS SEEN SINCE THE AROUND THE 12TH OF
FEBRUARY. HIGH TEMPERATURES WILL BE BELOW FREEZING SUNDAY ACROSS
JUST ABOUT ALL OF THE CWA. WITH THAT COLD AIR COMING IN I EXPECTED
ENHANCED LAKE EFFECT SNOW SHOWERS AS THERE IS GOOD UPPER AIR
SUPPORT AND DECENT LOW LEVEL WIND CONVERGENCE ON THE FRONT. SO I
HAVE HIGH POPS SUNDAY NIGHT WEST OF US-131. SNOWFALL SHOULD BE
LIMITED AS THE SNOW WILL MOSTLY HAPPEN AS THE FRONT DROPS SOUTH.
ONCE THE FRONT IS THROUGH WINDS BECOME NORTH DURING THE DAY SUNDAY
SO SNOW SHOWERS WILL MOSTLY BE NEAR THE LAKE SHORE. SUNDAY NIGHT
THE HIGH MOVES IN AND ANY SNOW SHOWERS SHOULD DIMINISH. THE UPPER
LEVEL JET CROSSING SOUTHWEST LOWER MICHIGAN EARLY MONDAY WILL
CAUSE THE INVERSION HEIGHT TO CRASH TOO... FARTHER LIMITING THE
POTENTIAL FOR SNOW SHOWERS.
HIGH PRESSURE RULES MONDAY DURING THE DAY INTO TUESDAY. THEN THE
NEXT SYSTEM DURING THE WEDNESDAY TO THURSDAY TIME FRAME. THERE ARE
BIG DIFFERENCES BETWEEN THE GFS AND ECMWF AS THE ECMWF HAS A MUCH
LARGER UPPER RIDGE OVER THE WEST COAST... CAUSING A MUCH DEEPER
TROUGH OVER THE CENTRAL UNITED STATES. THE ECMWF BRINGS EVEN
COLDER AIR IN BEHIND THAT SYSTEM THURSDAY INTO FRIDAY THAN THIS
WEEKEND. WITH THE GFS BEING MUCH FLATTER... NOT MUCH COLD AIR
FOLLOWS. GIVEN THE VARIABILITY ON THE MODELS AND THAT EVEN THE
ECMWF HAS NOT BEEN VERY CONSISTENT WITH THIS I WENT HALF WAY
BETWEEN THE TOO MODELS. FOR NOW THROUGH BOTH SUGGEST EVERY WARM
WEATHER WITH SHOWERS WEDNESDAY AHEAD OF THE COLD FRONT. THE ISSUE
STARTS THURSDAY ONCE THE COLD AIR COMES IN. WE WILL HAVE TO WATCH
THIS FOR ANOTHER POSSIBLE WINTER WEATHER EVENT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 100 PM EST FRI MAR 2 2012
THE SEVERE THREAT HAS SHIFTED A BIT SOUTH OF WHERE IT WAS EARLY
THIS MORNING. THERE IS NOW A HIGHER CHANCE THAT SVR STORMS WILL
REMAIN SOUTH OF THE TAF SITES. THAT SAID...STORMS WILL BE MOST
LIKELY OVER SRN LWR AND MAY CLIP THE SRN TAF SITES. LESSER CHANCES
NORTH. A WIDE SWING IN WEATHER EXPECTED OVER THE NEXT 24 HRS AS
SHOWERS WILL TRANSITION TO SNOW. MODERATE TO HEAVY SNOW IS
EXPECTED AT KMKG THIS EVENING AND LIGHT SNOW GRADUALLY SPREADING
OVER THE REST OF THE TAF SITES BY 06Z OR SO. EAST WINDS WILL
BECOME WNW WITH TIME AND BE VERY WINDY WITH GUSTS TO AROUND 40
KNOTS TONIGHT.
&&
.MARINE...
ISSUED AT 445 PM EST FRI MAR 2 2012
UPGRADED THE GALE WARNING TO A STORM WARNING FOR TONIGHT AS
INTENSE LOW GOES BY. GALES STILL POSSIBLE EARLY SATURDAY BEFORE
A GRADUAL DIMINISHING TREND THROUGH SATURDAY NIGHT AND SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 445 PM EST FRI MAR 2 2012
RIVER LEVELS ARE HIGH DUE TO RECENT RAINS... AND UP TO ANOTHER
INCH OF RAIN MAY FALL TONIGHT. LOCALLY HIGHER AMOUNTS ALSO
POSSIBLE. AT THIS TIME... EVEN WITH FUTURE QPF FACTORED IN... NO
SITES ARE FORECAST TO REACH OR EXCEED FLOOD STAGE. SEVERAL SITES
HOWEVER ARE IN FLOOD ADVISORIES... INCLUDING... GRAND RIVER AT
IONIA... PORTAGE RIVER NEAR VICKSBURG... GRAND RIVER AT JACKSON...
SYCAMORE CREEK AT HOLT... MAPLE RIVER AT MAPLE RAPIDS... AND
THORNAPPLE RIVER ABOVE HASTINGS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HIGH WIND WARNING FROM 9 PM THIS EVENING TO 7 AM EST SATURDAY
FOR MIZ046-051-052-056>059-064>067-071>074.
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 1 PM EST SATURDAY
FOR MIZ037>040-043>045-050.
LM...STORM WARNING FROM 9 PM THIS EVENING TO 7 AM EST SATURDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM....WDM
AVIATION...93
MARINE...MEADE
HYDROLOGY...MEADE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
603 AM EST FRI MAR 2 2012
.SYNOPSIS...
ISSUED AT 536 AM EST FRI MAR 2 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A TROUGH OVER THE WRN CONUS. A
MID/UPPER LEVEL LOW WAS LOCATED OVER ND WHILE SEVERAL PROMINENT
SHORTWAVES WERE EMBEDDED IN THE FLOW FROM UT/CO INTO THE CNTRL
PLAINS. AT THE SFC...A 1002 MB LOW WAS LOCATED OVER THE NW CORNER OF
WHILE A STRONGER AND DEEPENING 995 MB LOW WAS MOVING FROM OK INTO SW
MO. LIGHT WINDS PREVAILED OVER THE WRN GREAT LAKES AHEAD OF A WEAK
TROUGH OVER THE UPPER MS VALLEY. A WEAK SHRTWV FROM NE MN INTO NW WI
SUPPORTED NO MORE THAN PATCHY LIGHT SNOW OR FLURRIES. WITH ABUNDANT
LOW LEVEL MOISTURE OVER THE AREA...PATCHY FOG HAD ALSO
DEVELOPED OVER PORTIONS OF THE N CNTRL AND WRN CWA.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 536 AM EST FRI MAR 2 2012
TODAY...
SOME PATCHY LIGHT SNOW MAY BE POSSIBLE THIS MORNING INTO
EARLY AFTERNOON BUT IS NOT EXPECTED TO BE MEASURABLE. EVEN WITH
TEMPS LINGERING AROUND 30...CLOUDS WILL REMAIN THICK ENOUGH TO KEEP
MAX READINGS THIS AFTERNOON IN THE MID 30S. SOME LIGHT SNOW MAY
EXPAND INTO THE AREA LATE FROM S TO NORTH BUT ACCUMULATIONS DURING
BY 00Z SHOULD REMAIN GENERALLY LESS THAN A HALF INCH.
TONIGHT INTO SATURDAY...
MDLS HAVE COME INTO REASONABLY GOOD
AGREEMENT WITH THE DEVELOPING STORM SYSTEM AS THE SE COLORADO SHRTWV
LIFTS TO THE NORTHEAST AND PHASES WITH THE ND LOW. THE SW MO SFC LOW
IS EXPECTED TO DEEPEN RAPIDLY AS IT MOVES TO NW INDIANA THIS
AFTERNOON AND LAKE HURON TONIGHT. THE STRONGEST MID LEVEL FGEN
FORCING WITH THE STRENGTHENING DEFORMATION ZONE IS EXPECTED TO MOVE
THROUGH NW LOWER MI. EVEN THROUGH THE STRONGER DYNAMICS ARE EXPECTED
TO REMAIN TO THE SE OF THE CWA...THE AREA 290K-295K ISENTROPIC LIFT
AND STRONG MOISTURE TRANSPORT IS EXPECTED TO BRING AND EXPANDING
BAND OF PCPN INTO UPPER MICHIGAN. THE MODELS HAVE ALSO TRENDED
TOWARD A SLIGHTLY LATER ARRIVAL OF THE HEAVIER PCPN...AFT 00Z INTO
THE S CNTRL AND AFT 03Z INTO THE NRN HALF OF THE CWA. IN ADDITION
DOWNSLOPE NE FLOW FROM ONTARIO MAY FURTHER DELAY THE PCPN TOWARD
NEWBERRY.
WITH THE STRONGEST UPWARD MOTION MAINLY ABOVE THE DGZ...SNOW/WATER
RATIOS SHOULD REMAIN RELATIVELY LOW...GENERALLY IN THE 10/1 TO 15/1
RANGE. MODELS CONSENSUS QPF VALUES AN SUGGEST SNOWFALL AMOUNTS WILL
APPROACH WARNING CRITERIA (6 INCHES/12 HOURS) FROM SE DELTA INTO
LUCE COUNTY. STRONGER NE UPSLOPE FLOW BACKING NRLY INTO N CNTRL
UPPER MI WITH 850 MB TEMPS FROM -8C DROPPING TO NEAR -12C TO -14C BY
MIDDAY SATURDAY SHOULD BRING SUBSTANTIAL LAKE/TERRAIN ENHANCEMENT.
HOWEVER...KEPT THE WINTER STORM WATCH GOING SINCE CONFIDENCE IN
REACHING WARNING AMOUNTS REMAINS LIMITED GIVEN REMAINING DIFFERENCES
IN THE STRENGTH OF THE SYSTEM AND RESULTING QPF FIELDS
(ECMWF/GEM/UKMET WERE WEAKER THAN THE GFS/NAM). ADVISORIES MAY ALSO
BE NEEDED OVER THE WEST BY TONIGHT AS LAKE EFFECT/ENHANCED SNOW
AMOUNTS NEAR IWD/CMX INTO THE 2 TO 4 INCH RANGE ARE POSSIBLE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 536 AM EST FRI MAR 2 2012
NNW WINDS AT 850MB TO NNE WINDS NEAR THE SFC WILL ALLOW FOR SOME
BREAKDOWN IN THE PERFECT LES STRUCTURE...BUT 850MB TEMPS OF -14 TO
-18C /COOLEST OFF THE 02/00Z GFS/ SHOULD KEEP THE BEST CHANCE OF
SNOW SHOWERS GOING FROM ONTONAGON EASTWARD NEAR LAKE SUPERIOR.
EXPECT 1 TO 3 INCHES OF NEW SNOW NEAR LAKE SUPERIOR /HIGHEST NORTH
CENTRAL/ SATURDAY NIGHT...AS ANOTHER 500MB TROUGH DIPS IN FROM THE
NW. THE BEST DYNAMICS LOOK TO SLIDE ACROSS CENTRAL TO SOUTHERN WI.
BRIEF ENHANCEMENT WILL BE POSSIBLE DURING THE DAY SUNDAY...MAINLY IN
THE FORM OF ADDITIONAL CLOUD COVER AS ANOTHER SHORTWAVE NEARS FROM
THE WEST. SIMILAR TO SATURDAY NIGHT...MUCH OF THE ENERGY WILL FALL
OVER WI. NEW SNOW ON SUNDAY WILL LIKELY ADD UP TO ANOTHER INCH NEAR
LAKE SUPERIOR. LOOK FOR LES TO SLOWLY DIMINISH THROUGH SUNDAY
EVENING...AS SFC WINDS BECOME MORE WESTERLY PUSHING LES OFFSHORE.
THE SFC RIDGE SHOULD BE OVERHEAD DURING THE DAY SUNDAY HELPING TO
DRY US OUT.
THE FCST WARMUP FOR EARLY NEXT WEEK STILL LOOKS ON TRACK WITH THE
HIGH AMPLITUDE 500MB RIDGE SWINGING IN FROM THE WEST. EXPECT LOW TO
MID 40S TUESDAY AND WEDNESDAY /WITH HIGHER VALUES NOT OUT OF THE
QUESTION/. THE WARMEST READINGS WITH THE STRONG SSW WINDS SHOULD BE
SOUTH CENTRAL AND ACROSS THE FAVORED DOWNSLOPE AREAS NEAR LAKE
SUPERIOR. HIGH TEMPS ON WEDNESDAY ARE TRICKY WITH QUICK SW FLOW AS
THE 500MB RIDGE AXIS SHIFTS TO OUR EAST. TEMPS COULD BE SUPPRESSED
SLIGHTLY DUE TO ADDITIONAL CLOUD COVER AND THE CHANCE OF RAIN
SLIDING FROM CENTRAL MANITOBA TUESDAY TO JAMES BAY BY DAYBREAK
WEDNESDAY. TIMING ON THE COLD FRONT LOOKS TO BE CLOSER TO 12Z
WEDNESDAY OVER WESTERN AND CENTRAL UPPER MI...WHICH COULD RESULT IN
FALLING TEMPS DURING THE DAY. HAVE GONE MIDDLE OF THE ROAD FOR MUCH
OF THE EXTENDED PERIOD...TRYING TO ADD UNCERTAINTY TO THE WX TYPE
AND TIMING WEDNESDAY INTO WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 557 AM EST FRI MAR 2 2012
A TRICKY AVIATION FCST IS IN STORE FOR THE SHORT TERM. EXPECT
IFR/LIFR CONDITIONS AT KCMX/KSAW THROUGH THE MORNING WITH LOW LEVEL
MSTR TRAPPED BLO SUBSIDENCE INVRN IN THE WAKE OF DISTURBANCE MOVING
NEWD INTO ONTARIO. EXPECT CONDITIONS TO IMPROVE TO VFR WITH SOME
DAYTIME HEATING...BUT IFR CONDITIONS WL REDEVELOP TONIGHT UNDER
INCREASING CYCLONIC FLOW ARND DEEP LOW PRES MOVING NEWD THRU LWR MI.
LIGHT TO MODERATE SNOW WILL INCREASE BY LATE EVENING AND PERSIST
OVERNIGHT WITH VSBY FREQUENTLY BLO 2SM.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 536 AM EST FRI MAR 2 2012
LOW PRESSURE OVER MISSOURI WILL DEEPEN OVER SOUTHERN LOWER MICHIGAN
BY LATE AFTERNOON...BEFORE CROSSING CENTRAL LAKE HURON DURING THE
LATE EVENING HOURS...AND PUSHING INTO QUEBEC SATURDAY. NNE GALES OF
35 TO 40KTS WILL BE LIKELY FROM LATE THIS EVENING...AND TURN MORE
NORTHERLY THROUGH THE DAY SATURDAY. EXPECT A WEAKENING TROUGH TO
LINGER ACROSS THE UPPER GREAT LAKES THROUGH SATURDAY NIGHT. A RIDGE
WILL THEN BUILD ACROSS LS SUNDAY THROUGH MONDAY...BEFORE SHIFTING TO
THE LOWER GREAT LAKES MONDAY NIGHT. ANOTHER STRONG LOW...OVER
CENTRAL MANITOBA TUESDAY MORNING...WILL DRIFT TO CENTRAL ONTARIO
THROUGH THE DAY. ANOTHER PERIOD OF STRONGER WINDS...MAYBE UP TO
GALES AS THE TIME NEARS...WILL BE POSSIBLE TOWARD THE MIDDLE OF THE
WORK WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WATCH FROM THIS EVENING THROUGH SATURDAY AFTERNOON
FOR MIZ013-014-085.
WINTER STORM WATCH FROM THIS EVENING THROUGH SATURDAY EVENING
FOR MIZ005>007.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 7 PM EST SATURDAY FOR LSZ264>267.
GALE WARNING FROM 4 AM TO 1 PM EST SATURDAY FOR LSZ263.
GALE WARNING FROM 4 AM TO 7 PM EST SATURDAY FOR LSZ244-245-
248>251.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
537 AM EST FRI MAR 2 2012
.SYNOPSIS...
ISSUED AT 536 AM EST FRI MAR 2 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A TROUGH OVER THE WRN CONUS. A
MID/UPPER LEVEL LOW WAS LOCATED OVER ND WHILE SEVERAL PROMINENT
SHORTWAVES WERE EMBEDDED IN THE FLOW FROM UT/CO INTO THE CNTRL
PLAINS. AT THE SFC...A 1002 MB LOW WAS LOCATED OVER THE NW CORNER OF
WHILE A STRONGER AND DEEPENING 995 MB LOW WAS MOVING FROM OK INTO SW
MO. LIGHT WINDS PREVAILED OVER THE WRN GREAT LAKES AHEAD OF A WEAK
TROUGH OVER THE UPPER MS VALLEY. A WEAK SHRTWV FROM NE MN INTO NW WI
SUPPORTED NO MORE THAN PATCHY LIGHT SNOW OR FLURRIES. WITH ABUNDANT
LOW LEVEL MOISTURE OVER THE AREA...PATCHY FOG HAD ALSO
DEVELOPED OVER PORTIONS OF THE N CNTRL AND WRN CWA.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 536 AM EST FRI MAR 2 2012
TODAY...
SOME PATCHY LIGHT SNOW MAY BE POSSIBLE THIS MORNING INTO
EARLY AFTERNOON BUT IS NOT EXPECTED TO BE MEASURABLE. EVEN WITH
TEMPS LINGERING AROUND 30...CLOUDS WILL REMAIN THICK ENOUGH TO KEEP
MAX READINGS THIS AFTERNOON IN THE MID 30S. SOME LIGHT SNOW MAY
EXPAND INTO THE AREA LATE FROM S TO NORTH BUT ACCUMULATIONS DURING
BY 00Z SHOULD REMAIN GENERALLY LESS THAN A HALF INCH.
TONIGHT INTO SATURDAY...
MDLS HAVE COME INTO REASONABLY GOOD
AGREEMENT WITH THE DEVELOPING STORM SYSTEM AS THE SE COLORADO SHRTWV
LIFTS TO THE NORTHEAST AND PHASES WITH THE ND LOW. THE SW MO SFC LOW
IS EXPECTED TO DEEPEN RAPIDLY AS IT MOVES TO NW INDIANA THIS
AFTERNOON AND LAKE HURON TONIGHT. THE STRONGEST MID LEVEL FGEN
FORCING WITH THE STRENGTHENING DEFORMATION ZONE IS EXPECTED TO MOVE
THROUGH NW LOWER MI. EVEN THROUGH THE STRONGER DYNAMICS ARE EXPECTED
TO REMAIN TO THE SE OF THE CWA...THE AREA 290K-295K ISENTROPIC LIFT
AND STRONG MOISTURE TRANSPORT IS EXPECTED TO BRING AND EXPANDING
BAND OF PCPN INTO UPPER MICHIGAN. THE MODELS HAVE ALSO TRENDED
TOWARD A SLIGHTLY LATER ARRIVAL OF THE HEAVIER PCPN...AFT 00Z INTO
THE S CNTRL AND AFT 03Z INTO THE NRN HALF OF THE CWA. IN ADDITION
DOWNSLOPE NE FLOW FROM ONTARIO MAY FURTHER DELAY THE PCPN TOWARD
NEWBERRY.
WITH THE STRONGEST UPWARD MOTION MAINLY ABOVE THE DGZ...SNOW/WATER
RATIOS SHOULD REMAIN RELATIVELY LOW...GENERALLY IN THE 10/1 TO 15/1
RANGE. MODELS CONSENSUS QPF VALUES AN SUGGEST SNOWFALL AMOUNTS WILL
APPROACH WARNING CRITERIA (6 INCHES/12 HOURS) FROM SE DELTA INTO
LUCE COUNTY. STRONGER NE UPSLOPE FLOW BACKING NRLY INTO N CNTRL
UPPER MI WITH 850 MB TEMPS FROM -8C DROPPING TO NEAR -12C TO -14C BY
MIDDAY SATURDAY SHOULD BRING SUBSTANTIAL LAKE/TERRAIN ENHANCEMENT.
HOWEVER...KEPT THE WINTER STORM WATCH GOING SINCE CONFIDENCE IN
REACHING WARNING AMOUNTS REMAINS LIMITED GIVEN REMAINING DIFFERENCES
IN THE STRENGTH OF THE SYSTEM AND RESULTING QPF FIELDS
(ECMWF/GEM/UKMET WERE WEAKER THAN THE GFS/NAM). ADVISORIES MAY ALSO
BE NEEDED OVER THE WEST BY TONIGHT AS LAKE EFFECT/ENHANCED SNOW
AMOUNTS NEAR IWD/CMX INTO THE 2 TO 4 INCH RANGE ARE POSSIBLE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 536 AM EST FRI MAR 2 2012
NNW WINDS AT 850MB TO NNE WINDS NEAR THE SFC WILL ALLOW FOR SOME
BREAKDOWN IN THE PERFECT LES STRUCTURE...BUT 850MB TEMPS OF -14 TO
-18C /COOLEST OFF THE 02/00Z GFS/ SHOULD KEEP THE BEST CHANCE OF
SNOW SHOWERS GOING FROM ONTONAGON EASTWARD NEAR LAKE SUPERIOR.
EXPECT 1 TO 3 INCHES OF NEW SNOW NEAR LAKE SUPERIOR /HIGHEST NORTH
CENTRAL/ SATURDAY NIGHT...AS ANOTHER 500MB TROUGH DIPS IN FROM THE
NW. THE BEST DYNAMICS LOOK TO SLIDE ACROSS CENTRAL TO SOUTHERN WI.
BRIEF ENHANCEMENT WILL BE POSSIBLE DURING THE DAY SUNDAY...MAINLY IN
THE FORM OF ADDITIONAL CLOUD COVER AS ANOTHER SHORTWAVE NEARS FROM
THE WEST. SIMILAR TO SATURDAY NIGHT...MUCH OF THE ENERGY WILL FALL
OVER WI. NEW SNOW ON SUNDAY WILL LIKELY ADD UP TO ANOTHER INCH NEAR
LAKE SUPERIOR. LOOK FOR LES TO SLOWLY DIMINISH THROUGH SUNDAY
EVENING...AS SFC WINDS BECOME MORE WESTERLY PUSHING LES OFFSHORE.
THE SFC RIDGE SHOULD BE OVERHEAD DURING THE DAY SUNDAY HELPING TO
DRY US OUT.
THE FCST WARMUP FOR EARLY NEXT WEEK STILL LOOKS ON TRACK WITH THE
HIGH AMPLITUDE 500MB RIDGE SWINGING IN FROM THE WEST. EXPECT LOW TO
MID 40S TUESDAY AND WEDNESDAY /WITH HIGHER VALUES NOT OUT OF THE
QUESTION/. THE WARMEST READINGS WITH THE STRONG SSW WINDS SHOULD BE
SOUTH CENTRAL AND ACROSS THE FAVORED DOWNSLOPE AREAS NEAR LAKE
SUPERIOR. HIGH TEMPS ON WEDNESDAY ARE TRICKY WITH QUICK SW FLOW AS
THE 500MB RIDGE AXIS SHIFTS TO OUR EAST. TEMPS COULD BE SUPPRESSED
SLIGHTLY DUE TO ADDITIONAL CLOUD COVER AND THE CHANCE OF RAIN
SLIDING FROM CENTRAL MANITOBA TUESDAY TO JAMES BAY BY DAYBREAK
WEDNESDAY. TIMING ON THE COLD FRONT LOOKS TO BE CLOSER TO 12Z
WEDNESDAY OVER WESTERN AND CENTRAL UPPER MI...WHICH COULD RESULT IN
FALLING TEMPS DURING THE DAY. HAVE GONE MIDDLE OF THE ROAD FOR MUCH
OF THE EXTENDED PERIOD...TRYING TO ADD UNCERTAINTY TO THE WX TYPE
AND TIMING WEDNESDAY INTO WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1205 AM EST FRI MAR 2 2012
A TRICKY AVIATION FCST IS IN STORE FOR THE SHORT TERM. EXPECT
IFR/LIFR CONDITIONS AT ALL 3 SITES THRU THE MRNG WITH LLVL MSTR
TRAPPED BLO SUBSIDENCE INVRN IN THE WAKE OF DISTURBANCE MOVING NEWD
INTO ONTARIO. IWD WL LIKELY SEE THE WORST CONDITIONS EARLY IN THE
PERIOD WITH SOME CLRG/RADIATION FOG BEFORE THE ARRIVAL OF THICKER
CLDS AGAIN TOWARD 09Z CAUSES THIS FOG TO BREAK UP A BIT. EXPECT
CONDITIONS TO IMPROVE TO VFR WITH SOME DAYTIME HEATING...BUT IFR
CONDITIONS WL REDEVELOP TNGT UNDER INCRSG CYC FLOW ARND DEEP LO PRES
MOVING NEWD THRU LWR MI.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 536 AM EST FRI MAR 2 2012
LOW PRESSURE OVER MISSOURI WILL DEEPEN OVER SOUTHERN LOWER MICHIGAN
BY LATE AFTERNOON...BEFORE CROSSING CENTRAL LAKE HURON DURING THE
LATE EVENING HOURS...AND PUSHING INTO QUEBEC SATURDAY. NNE GALES OF
35 TO 40KTS WILL BE LIKELY FROM LATE THIS EVENING...AND TURN MORE
NORTHERLY THROUGH THE DAY SATURDAY. EXPECT A WEAKENING TROUGH TO
LINGER ACROSS THE UPPER GREAT LAKES THROUGH SATURDAY NIGHT. A RIDGE
WILL THEN BUILD ACROSS LS SUNDAY THROUGH MONDAY...BEFORE SHIFTING TO
THE LOWER GREAT LAKES MONDAY NIGHT. ANOTHER STRONG LOW...OVER
CENTRAL MANITOBA TUESDAY MORNING...WILL DRIFT TO CENTRAL ONTARIO
THROUGH THE DAY. ANOTHER PERIOD OF STRONGER WINDS...MAYBE UP TO
GALES AS THE TIME NEARS...WILL BE POSSIBLE TOWARD THE MIDDLE OF THE
WORK WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WATCH FROM THIS EVENING THROUGH SATURDAY AFTERNOON
FOR MIZ013-014-085.
WINTER STORM WATCH FROM THIS EVENING THROUGH SATURDAY EVENING
FOR MIZ005>007.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 7 PM EST SATURDAY FOR LSZ264>267.
GALE WARNING FROM 4 AM TO 1 PM EST SATURDAY FOR LSZ263.
GALE WARNING FROM 4 AM TO 7 PM EST SATURDAY FOR LSZ244-245-
248>251.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...KF
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
646 PM CST SAT MAR 3 2012
.UPDATE...
00Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
IN THE SHORT TERM...A WEAK SHORTWAVE TROUGH WILL DIVE SOUTHEAST OUT
OF CENTRAL CANADA TONIGHT. CLOUDS WILL THICKEN BACK OVER THE WESTERN
HALF OF MN WITH LIGHT SNOW DEVELOPING AROUND DAYBREAK SUNDAY. THE
CORE OF THE SNOW ACCUMULATION IS EXPECTED TO OCCUR OVER SOUTHWEST
HALF OF MN WITH SNOWFALL AMOUNTS UP TO TWO INCHES. THE REST OF
FORECAST AREA...SNOW ACCUMULATIONS WILL BE GENERALLY LESS THAN AN
INCH. THE SHORTWAVE TROUGH IS FORECAST TO PASS THROUGH OUR
FORECAST AREA BY SUNDAY EVENING.
THE FORECAST CHALLENGE BEYOND SUNDAY...WILL BE TEMPERATURES. A WARM
FRONT WILL DEVELOP OVER THE ROCKIES...AND LIFT NORTHEAST OVER THE
MIDWEST BY TUESDAY AFTERNOON. 850 MB TEMPERATURES WILL WARM TO PLUS
10 DEGREES CELSIUS OVER PARTS OF SOUTH CENTRAL MN. WITH THE LACK OF
SNOW COVER AND BARE GROUND OVER NORTHERN IOWA/SRN MN...SFC
TEMPERATURES SHOULD CLIMB WELL INTO THE 50S ON TUESDAY...WITH
TEMPERATURES WARMING INTO THE UPPER 40S AND LOWER 50S OVER SNOW
COVERED FIELDS IN CENTRAL MN AND PARTS OF WEST CENTRAL WISCONSIN.
MODELS BRING A COOL FRONT THROUGH THE AREA TUESDAY NIGHT. SCATTERED
SHOWERS OCCURRING AHEAD OF THE FRONTAL BOUNDARY. MODELS CONTINUE TO
SHOW SOMEWHAT OF A ZONAL FLOW OVER SOUTHERN CANADA...TEMPERATURES ON
WEDNESDAY SHOULD BE SLIGHTLY COOLER...STILL RATHER MILD FOR THIS
TIME OF YEAR WITH MAX TEMPS IN THE 30S AND 40S.
THE MEDIUM RANGE MODELS DIFFER ON THE AMPLIFICATION OF THE TROUGH
THAT IS FORECAST TO CARVE OVER THE UPPER GREAT LAKES MID
WEEK (THURSDAY AND FRIDAY TIMEFRAME). THE ECMWF HAS A SHARPER
TROUGH WHILE THE GFS IS NOT THAT PRONOUNCED. PREFER THE GFS
SOLUTION THROUGH THE REST OF THE WORK WEEK...WITH ONLY BRINGING
SOME COOLER AIR INTO THE UPPER MIDWEST.
IN THE LONG TERM...THE LATEST GFS MODEL DEVELOPS A REX BLOCK OVER
THE CONUS...GIVING MUCH OF OUR FORECAST A DRY AND MILD CONDITIONS
THROUGH THE UPCOMING WEEKEND.
&&
.AVIATION.../00Z TAF ISSUANCE/
TRICKY CLOUD FORECAST THIS EVENING AS SFC RIDGE AXIS WORKS INTO
WRN MN FROM THE DAKOTAS. CYCLONIC FLOW STILL IN PLACE ACROSS ERN
MN INTO WI...WITH -SN STILL LINGERING ALONG REMNANT SFC TROUGH IN
THE EAU AREA. HRRR REFLECTIVITY FORECASTS KEEP -SN GOING AROUND
EAU THROUGH THE MORNING...THOUGH ENDED -SN MENTION AT 09Z WHEN
TROUGH LOSES ITS DEFINITION. CLEARING LINE IS IN THE NEIGHBORHOOD
OF STC/MSP...BUT WILL HAVE TO WATCH THE THREAT FOR THESE CLOUDS
BUILDING BACK WEST THIS EVENING UNTIL THE RIDGE AXIS SHOWS UP...WHICH
IS NOT UNTIL AFTER 06Z. STRONG WAVE CURRENTLY WORKING INTO MONTANA
WILL REPRESENT THE NEXT PROBLEM. THIS WILL SEND A CLIPPER FROM BIS TO
DSM DURING THE DAY ON SUNDAY...WHICH WILL SEND A QUICK BURST OF
SNOW ACROSS SW MN. CONFIDENCE HIGHEST IN ACCUMULATING SNOW
OCCURRING AT RWF /1-2 INCHES/...WITH AXN ENDING UP EAST OF THE
BEST SNOW...WHILE MSP/STC LOOK TO GET BRUSHED BY THIS EVENT. WITH
THE LOW MOVING ACROSS THE SW TIP OF MN...WILL SEE SOME RATHER
RAPID WIND SHIFTS THIS TAF PERIOD...THOUGH SPEEDS WILL BE VERY
LIGHT. WILL SEE WINDS SET UP OUT OF THE SE TONIGHT/SUN MORNING AS
THE LOW WORKS ACROSS NODAK...WITH A RAPID BACKING OF THE WINDS TO
THE NW AS THE LOW TRACKS FROM ERN SODAK INTO CENTRAL IA. BEHIND
THE SN...MVFR TO LOW END VFR CIGS WILL LIKELY HANG AROUND INTO
SUNDAY NIGHT.
KMSP...CONFIDENCE SOMEWHAT LOW ON CLOUD FORECAST AS THE FIELD SITS
ON THE BACK EDGE OF THE CLOUDS. WITH RIDGE AXIS MOVING IN FROM THE
WEST AND THE GENERALLY CLEAR SKIES BENEATH IT...PLAYED THE IDEA OF
MSP EVENTUALLY CLEARING. HOWEVER...NOT SEEING A GOOD PUSH OF DRY
AIR WITH THE RIDGE AND WOULD NOT BE SURPRISED IF THE CLOUDS BUILD BACK
WEST LATER THIS EVENING AND STAY PUT UNTIL MONDAY MORNING WHEN THE
STRONG PUSH OF WAA ARRIVES. SUNDAY SN LOOKS TO MAINLY STAY WEST OF
HERE AND MSP LOOKS TO BE ON THE EDGE OF SEEING VERY LIGHT SNOW OR
NO SNOW AT ALL. KEPT THE PROB30 GOING...BUT PUSHED IT OUT A COUPLE
MORE HOURS. SREF PROBS WOULD SUPPORT AN 18-20 TIMING...BUT WRF-
NMM REFLECTIVITY FORECASTS ALONG WITH ECWMF/NAM TIMING WOULD
SUGGEST LIGHT SNOW TIMING MORE OUT IN THE 20-24 RANGE.
//OUTLOOK...MONDAY THROUGH THURSDAY...
.MON-TUE...VFR. BREEZY S/SW WINDS.
.TUE NGT-WED...MVFR CIG/VSBY POSSIBLE. CHANCE OF -RA/-SN.
.THU...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JVM/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
332 AM CST FRI MAR 2 2012
.DISCUSSION...
A TROUGH OF LOW PRESSURE CURVES SOUTHWARD ACROSS EASTERN MN EARLY
THIS MORNING FROM A LOW PRESSURE CENTER IN EASTERN NORTH DAKOTA.
CLEARING HAS PROGRESSED TO NEAR A KLXL TO KFRM LINE. THE DRY WEDGE
IS WELL DEFINED IN SHORT TERM MODEL GUIDANCE AND WILL PUSH INTO
THE EASTERN CWA THIS MORNING. SOME MID/HIGH LEVEL CLOUDINESS WILL
BE STREAMING NORTHEASTWARD ACROSS SE MN AND WEST CENTRAL WI TODAY...
KEEPING IT PARTLY TO MOSTLY CLOUDY IN THESE AREAS. SOME SUNSHINE
TODAY SHOULD AID IN HIGHS REACHING 33 TO 38 DEGREES FROM WEST TO
EAST.
THE LOW IN EASTERN ND WILL BE MOVING SE ACROSS THE CWA TONIGHT
AND EARLY SATURDAY. THALER QG AND ISENTROPIC ANALYSIS INDICATES
SOME SNOW WILL LIKELY OCCUR TONIGHT...ESPECIALLY ALONG THE LEADING
EDGE OF THE LOW LEVEL WAA. ACCUMULATIONS WILL BE MINOR AND LESS
THAN AN INCH. SOME LIGHT SNOW IS STILL POSSIBLE ON SATURDAY OVER
FAR EASTERN MN AND WEST CENTRAL WI WITH THE LOW LEVEL CYCLONIC
FLOW.
THERE REMAINS SOME SPREAD WITH THE TRACK OF A CLIPPER LIKE LOW
PRESSURE SYSTEM PASSING SOUTHEAST ACROSS THE EASTERN DAKOTAS/MN ON
SUNDAY. THE GEM AND ECMWF ARE PRETTY BULLISH ON PRECIP ACROSS THE
SOUTHWEST QUARTER OF MN WHILE THE NAM IS FARTHER EAST WITH THE
PRECIPITATION PASSING ACROSS THE TWIN CITIES. PUT MORE WEIGHT ON
THE SREF POPS FOR SUNDAY WHICH KEPT MUCH OF THE LIGHT SNOW FROM
WEST CENTRAL THROUGH SOUTH CENTRAL MN. PERHAPS AN INCH OF
ACCUMULATION IN THIS REGION.
THE LONGER TERM PORTION OF THE FORECAST STILL FEATURES A BIG WARM-UP
FROM MONDAY INTO WEDNESDAY. LITTLE ARGUMENT SEEN BETWEEN THE GFS
AND ECMWF IN THIS PERIOD. HOWEVER...BEYOND WEDNESDAY SOME CHANGES
WERE COLLABORATED ON INCLUDING HIGHS ON THURSDAY AS WELL AS
PRECIPITATION CHANCES. THE ECMWF AND GFS BECOME 180 DEGREES OUT OF
PHASE WITH REGARDS TO THE H5 HEIGHT FIELD BY THURSDAY WITH THE
ECMWF SHOWING A LARGE SCALE TROF VERSUS RIDGING ON THE GFS. ONE
THING THEY DO AGREE ON IS THAT WE SHOULD BE IN THE WAKE OF A
FRONTAL BOUNDARY AND POPS WERE REMOVED FOR THURSDAY. HIGH
TEMPERATURES FOR THURSDAY OF 45 TO 50 WERE LOWERED INTO THE 40-43
DEGREE RANGE.
&&
.AVIATION... /06Z TAF ISSUANCE/
BURST OF -SN OUT AHEAD OF SFC TROUGH ALREADY WORKING INTO WESTERN
WI. BASED ON DOWNSTREAM OBS...EXPECT 1 1/2SM -SN FOR 2-3 HRS TO
BEGIN THE TAF AT EAU. HAVE NOT SEEN MUCH FZDZ BEHIND THE
SN...INSTEAD...THERE HAS BEEN ABOUT 2 HRS OF IFR CIGS...FOLLOWED
BY 1-2 HRS OF MVFR CIGS BEFORE SKIES CLEAR OUT. TRIED TO TIME IFR
TO MVFR IMPROVEMENT AS BEST I COULD...BUT MAY BE HOLDING ON TO IFR
CIGS AT ERN TAF SITES A BIT TO LONG. RUC 925-850 RH HAS HAD A
GOOD HANDLE ON CLEARING WORKING THROUGH WRN MN THIS EVENING...SO
USED THAT TO TIME VFR CONDITIONS IN TO TERMINALS...AGAIN IF
ANYTHING HOLDING ON TO MVFR CIGS A LITTLE LONGER THAN THE RUC
WOULD INDICATE. ONLY QUESTION MARK WITH THE CLEARING IS AT
EAU...AS THE RUC DOES NOT TAKE WRLY FLOW THIS FAR EAST IN THE
MORNING...INDICATING THE STRATUS MAY BE LEFT HANGING OVER THERE.
SCT EAU OUT AT 017...BUT WILL HAVE TO SEE HOW THE CLEARING DOES.
MUCH OF FRIDAY LOOKS GOOD...WITH ONLY PASSING CIRRUS EXPECTED FROM
STRONG JET SCREAMING ACROSS THE SOUTH. WILL JUST HAVE TO TIME
RETURN OF STRATUS AS LOW CURRENTLY IN NODAK SWINGS INTO MN AND
BEGINS TO BE ABSORBED BY SRN STREAM ENERGY. GFS/NAM HAVE SIMILAR
TIMING WITH BRINGING THESE CIGS BACK THROUGH...SO CONFIDENCE
ACTUALLY FAIRLY HIGH ON TIMING OF STRATUS RETURN...HARDER TO SAY
WHAT LEVEL IT WILL BE AT THIS FAR OUT...BUT AT LEAST HIGH END MVFR
SEEMS CERTAIN. IN ADDITION TO THE CLOUDS COMING DOWN...BUFKIT
SOUNDING AND PRECIP FORECASTS FROM THE NAM/GFS WOULD SAY SNOW
SHOWERS WILL ACCOMPANY THE CLOUDS...SO INTRODUCED SOME PROB30S TO
ACCOUNT FOR THAT. FINALLY...SRN STREAM WAVE WILL SIGNIFICANTLY
STRENGTHEN AS IT MOVES INTO MICH FRIDAY EVENING...WITH NW WINDS
PICKING UP IN STRENGTH IN RESPONSE...WITH SOME PRETTY GOOD
SPEEDS/GUSTS INDICATED TO DEVELOP FRIDAY NIGHT.
KMSP...MAY SEE A BRIEF PERIOD OF FZDZ AS -SN PULLS OUT...BUT SUCH
OBS HAVE BEEN FEW AND FAR BETWEEN...SO HAVE NO MENTION IN TAF.
BASED ON OBS TO THE WEST...EXPECT IFR CIGS TO HANG ON FOR UP TO
TWO HOURS...BEFORE GOING UP TO SUB 017 MVFR. AFTER THAT...RUC HAS
HAD A GREAT HANDLE ON CLEARING WORKING INTO THE FIELD AROUND
10Z...SO HAVE THINGS GOING SCT THEN. HARD PRESSED TO FIND MUCH
CLOUD COVER OUTSIDE OF CIRRUS DURING THE DAY FRIDAY...SO
SIGNIFICANTLY IMPROVED GOING FORECAST UNTIL STRATUS RETURNS AFTER
00Z. ALSO LOOKS LIKELY THAT MUCH OF SATURDAY AFTER 06Z WILL SEE
BOUTS OF -SHSN.
//OUTLOOK...SATURDAY THROUGH TUESDAY...
.SAT-SUN...MVFR CIGS. -SHSN ENDING SAT EVENING.
.MON-TUE...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1211 AM CST FRI MAR 2 2012
.UPDATE...
06Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
SPLIT FORCING CROSSING THE AREA TONIGHT. ONE WAVE OVER NORTH
DAKOTA TO AFFECT MAINLY NORTHERN MN AND THE OTHER..SOMEWHAT LESS
DEFINED OVER EASTERN NEBRASKA. CLOUD TOPS NOW COOLING...AFTER A
SLIGHT DECREASE DURING THE MORNING...OVER SOUTHWEST MN AND
NORTHWEST IOWA. THIS AREAS OF ISEN LIFT AND WEAK FGEN MOVES INTO
SOUTH CENTRAL AND SOUTHEAST MINNESOTA THIS EVENING...ALTHOUGH THE
BETTER MID LEVEL THETA E ADVECTION REMAINS ACROSS IOWA. LATER IN
THE EVENING AND OVERNIGHT...THE GFS AND NAM HAVE BEEN CONSISTENT
IN THE LAST 2 RUNS IN BRINGING AN AREA OF THALER QG VERT VEL AND
AND INSTANTANEOUS PRECIP FIELDS MAINLY ACROSS CENTRAL AND PARTS OF
SOUTHERN MN. THIS DOES TEND TO WEAKEN AFTER MIDNIGHT BUT ENOUGH TO
BRING AREAS OF LIGHT SNOW ACROSS THE AREAS. WILL HOWEVER...TRY TO
NARROW DOWN THE LIKELY POPS TO OVER MAINLY THE MN CWA. SOME HINT
OF SLIGHT LIFT REMAINING AFTER THE HIGHER LAYER MOISTURE MOVES OUT
LATE TONIGHT INTRODUCED PATCHY LIGHT FZDZ. THE WAVE OVER THE
SOUTHERN ROCKIES APPEARS TO BE SLIDING TO OUR SOUTHEAST AND WILL
AFFECT EASTERN IOWA AND SOUTHERN WISCONSIN.
FOR THE REST OF THE WEEKEND A COUPLE OF OTHER CHANCES OF LIGHT
SNOW AND FLURRIES....ALTHOUGH THE MORE WIDESPREAD CHANCE WOULD BE
LATER FRIDAY NIGHT AND SATURDAY AS THE CIRCULATION OVER SOUTHERN
CANADA/MONTANA SLIDES SOUTHEAST OVER THE AREA. THIS WILL ALSO
BRING A BRIEF VISIT OF NEAR OR SLIGHTLY BELOW NORMAL TEMPS. THE
STRONG NORTHWEST UPPER JET WILL LIKELY BRING AN IMPULSE WITH A
WARM ADVECTION PATTERN ON SUNDAY...BUT SOME UNCERTAINTY IN WHERE
A NARROW BAND OF SNOW MAY SET UP.
THE SIGNIFICANT WARMING TREND LOOKS TO BE ON TRACK FOR TUESDAY
INTO WEDNESDAY. IT SURE LOOKS LIKE A POTENTIAL OF 55 TO 60. AS
IN THE PREVIOUS DISCUSSION EVEN MIXING FROM 925 MB YIELDS A
WIDE AREA OF 50S TO NEAR 60. LOOKS LIKE SOME POTENTIAL FOR
OVERRUNNING PRECIP ALONG THE TIGHT THICKNESS GRADIENT BEHIND THE
COLD FRONT WEDNESDAY INTO THURSDAY...BUT WILL FOLLOW THE BLENDED
LOWER POPS FOR NOW. IT ALSO LOOKS LIKE A SIGNAL FOR A POTENTIAL
PLAINS STORM SYSTEM LATE NEXT WEEK AS THE SPC SEVERE WEATHER
ANALOG SITE LIGHTING UP A BIT ABOUT MARCH 8-9.
&&
.AVIATION.../06Z TAF ISSUANCE/
BURST OF -SN OUT AHEAD OF SFC TROUGH ALREADY WORKING INTO WESTERN
WI. BASED ON DOWNSTREAM OBS...EXPECT 1 1/2SM -SN FOR 2-3 HRS TO
BEGIN THE TAF AT EAU. HAVE NOT SEEN MUCH FZDZ BEHIND THE
SN...INSTEAD...THERE HAS BEEN ABOUT 2 HRS OF IFR CIGS...FOLLOWED
BY 1-2 HRS OF MVFR CIGS BEFORE SKIES CLEAR OUT. TRIED TO TIME IFR
TO MVFR IMPROVEMENT AS BEST I COULD...BUT MAY BE HOLDING ON TO IFR
CIGS AT ERN TAF SITES A BIT TO LONG. RUC 925-850 RH HAS HAD A
GOOD HANDLE ON CLEARING WORKING THROUGH WRN MN THIS EVENING...SO
USED THAT TO TIME VFR CONDITIONS IN TO TERMINALS...AGAIN IF
ANYTHING HOLDING ON TO MVFR CIGS A LITTLE LONGER THAN THE RUC
WOULD INDICATE. ONLY QUESTION MARK WITH THE CLEARING IS AT
EAU...AS THE RUC DOES NOT TAKE WRLY FLOW THIS FAR EAST IN THE
MORNING...INDICATING THE STRATUS MAY BE LEFT HANGING OVER THERE.
SCT EAU OUT AT 017...BUT WILL HAVE TO SEE HOW THE CLEARING DOES.
MUCH OF FRIDAY LOOKS GOOD...WITH ONLY PASSING CIRRUS EXPECTED FROM
STRONG JET SCREAMING ACROSS THE SOUTH. WILL JUST HAVE TO TIME
RETURN OF STRATUS AS LOW CURRENTLY IN NODAK SWINGS INTO MN AND
BEGINS TO BE ABSORBED BY SRN STREAM ENERGY. GFS/NAM HAVE SIMILAR
TIMING WITH BRINGING THESE CIGS BACK THROUGH...SO CONFIDENCE
ACTUALLY FAIRLY HIGH ON TIMING OF STRATUS RETURN...HARDER TO SAY
WHAT LEVEL IT WILL BE AT THIS FAR OUT...BUT AT LEAST HIGH END MVFR
SEEMS CERTAIN. IN ADDITION TO THE CLOUDS COMING DOWN...BUFKIT
SOUNDING AND PRECIP FORECASTS FROM THE NAM/GFS WOULD SAY SNOW
SHOWERS WILL ACCOMPANY THE CLOUDS...SO INTRODUCED SOME PROB30S TO
ACCOUNT FOR THAT. FINALLY...SRN STREAM WAVE WILL SIGNIFICANTLY
STRENGTHEN AS IT MOVES INTO MICH FRIDAY EVENING...WITH NW WINDS
PICKING UP IN STRENGTH IN RESPONSE...WITH SOME PRETTY GOOD
SPEEDS/GUSTS INDICATED TO DEVELOP FRIDAY NIGHT.
KMSP...MAY SEE A BRIEF PERIOD OF FZDZ AS -SN PULLS OUT...BUT SUCH
OBS HAVE BEEN FEW AND FAR BETWEEN...SO HAVE NO MENTION IN TAF.
BASED ON OBS TO THE WEST...EXPECT IFR CIGS TO HANG ON FOR UP TO
TWO HOURS...BEFORE GOING UP TO SUB 017 MVFR. AFTER THAT...RUC HAS
HAD A GREAT HANDLE ON CLEARING WORKING INTO THE FIELD AROUND
10Z...SO HAVE THINGS GOING SCT THEN. HARD PRESSED TO FIND MUCH
CLOUD COVER OUTSIDE OF CIRRUS DURING THE DAY FRIDAY...SO
SIGNIFICANTLY IMPROVED GOING FORECAST UNTIL STRATUS RETURNS AFTER
00Z. ALSO LOOKS LIKELY THAT MUCH OF SATURDAY AFTER 06Z WILL SEE
BOUTS OF -SHSN.
//OUTLOOK...SATURDAY THROUGH TUESDAY...
.SAT-SUN...MVFR CIGS. -SHSN ENDING SAT EVENING.
.MON-TUE...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPR/MPG
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1152 AM CST FRI MAR 2 2012
...UPDATE TO AVIATION...
.UPDATE...
/ISSUED 615 AM CST FRI MAR 2 2012/
SURFACE LOW WAS TRACKING NORTHEAST ACROSS SOUTHERN MISSOURI EARLY
THIS MORNING AND WAS LOCATED NEAR SPRINGFIELD AT 12Z (7 AM).
SCATTERED CONVECTION CONTINUED ALONG AND JUST BEHIND THE ASSOCIATED
FRONT. SEVERE STORMS THAT PRODUCED LARGE HAIL ACROSS PORTIONS OF
CENTRAL MISSOURI EARLIER THIS MORNING HAD TRACKED EAST OF THE
AREA ON THE NOSE OF THE LOW LEVEL JET.
MOST UNSTABLE CAPES AROUND 1000 J/KG AND OVER 70 KTS OF DEEP
LAYERED SHEAR WILL SUPPORT THE POTENTIAL FOR ADDITIONAL SEVERE
STORMS AHEAD OF THE FRONT THIS MORNING. STORMS EARLY ON WILL
CONTINUE TO BE PRIMARILY ELEVATED IN NATURE BUT THERE IS CONCERN
THAT STORMS WILL BECOME ROOTED NEAR OR AT THE SURFACE ACROSS SOUTH
CENTRAL MISSOURI AS THE MORNING PROGRESSES. LATEST RUC ANALYSIS
DEPICTS DECREASING MIXED LAYER INHIBITION ACROSS FAR SOUTH CENTRAL
MISSOURI. THIS TREND WILL LIKELY CONTINUE AS RICHER LOW LEVEL
MOISTURE STREAMS NORTH. IF STORMS BECOME SURFACE BASED THE RISK
FOR DAMAGING WINDS AND ISOLATED TORNADOES WOULD INCREASE.
FOSTER
&&
.DISCUSSION...
/ISSUED 245 AM CST FRI MAR 2 2012/
THUNDERSTORMS WERE RAPIDLY DEVELOPING EARLY THIS MORNING ACROSS
PORTIONS OF SOUTHWEST AND CENTRAL MISSOURI NORTHEAST OF A SURFACE
LOW PRESSURE SYSTEM LOCATED IN NORTHEAST OKLAHOMA. STRONG WARM AIR
AND MOISTURE ADVECTION EAST OF THIS LOW OVER TOP THE BOUNDARY
LAYER WAS RESULTING RAPID DESTABILIZATION. MOST UNSTABLE CAPE OF
AROUND 1000 TO NEAR 2000 J/KG WAS NOSING INTO SOUTHERN MISSOURI.
THIS INSTABILITY COUPLED WITH STRONG DEEP LAYERED SHEAR WILL
SUPPORT STRONG TO SEVERE CONVECTION EARLY THIS MORNING. CONVECTIVE
MODE WILL BE ELEVATED SUPERCELLS WITH LARGE HAIL THE PRIMARY RISK. THIS
ACTIVITY WILL RACE EASTWARD.
WILL HAVE TO CLOSELY MONITOR CONVECTIVE TRENDS FARTHER SOUTH ALONG
THE ARKANSAS BORDER CLOSER TO THE SURFACE WARM FRONT. CONVECTION
COULD BECOME ROOTED NEAR THE SURFACE IN THIS AREA RESULTING IN A
GREATER RISK FOR DAMAGING WINDS
EXPECT ACTIVITY TO MOVE EAST OF THE AREA BY EARLY AFTERNOON IF NOT
EARLIER. COLDER AIR ADVECTION WILL DEVELOP DURING THE AFTERNOON AS
THE SURFACE LOW MOVES OFF TO THE EAST RESULTING STEADY IF NOT
FALLING TEMPERATURES. A CHILLY NIGHT IS IN STORE TONIGHT WITH MANY
AREAS NEAR THE FREEZING MARK. BELOW NORMAL TEMPERATURES ARE IN
STORE FOR SATURDAY AS AN UPPER TROUGH SWINGS ACROSS THE REGION.
MODERATING TEMPERATURES WILL BEGIN SUNDAY WITH A MORE SUBSTANTIAL
WARMING TREND BEGINNING MONDAY AS A SOUTHERLY FLOW DEVELOPS. WILL
HAVE TO MONITOR FIRE WEATHER CONDITIONS MONDAY GIVEN GUSTY
SOUTHERLY WINDS AND EXISTING DRY AIR MASS.
PRECIPITATION CHANCES RETURN BY THE MIDDLE OF NEXT WEEK AS THE
NEXT UPPER TROUGH APPROACHES.
&&
.AVIATION...
FOR THE 18Z TAFS...FLIGHT CONDITIONS WILL CONTINUE TO IMPROVE
THROUGH THIS AFTERNOON. SURFACE WINDS WILL REMAIN GUSTY FROM THE
NORTHWEST INTO LATE AFTERNOON HOURS HOWEVER. EXPECT VFR
CONDITIONS AFTER 19Z FOR ALL TERMINALS.
HATCH
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
623 AM CST FRI MAR 2 2012
...MESOSCALE CONVECTIVE DISCUSSION...
.UPDATE...
/ISSUED 615 AM CST FRI MAR 2 2012/
SURFACE LOW WAS TRACKING NORTHEAST ACROSS SOUTHERN MISSOURI EARLY
THIS MORNING AND WAS LOCATED NEAR SPRINGFIELD AT 12Z (7 AM).
SCATTERED CONVECTION CONTINUED ALONG AND JUST BEHIND THE ASSOCIATED
FRONT. SEVERE STORMS THAT PRODUCED LARGE HAIL ACROSS PORTIONS OF
CENTRAL MISSOURI EARLIER THIS MORNING HAD TRACKED EAST OF THE
AREA ON THE NOSE OF THE LOW LEVEL JET.
MOST UNSTABLE CAPES AROUND 1000 J/KG AND OVER 70 KTS OF DEEP
LAYERED SHEAR WILL SUPPORT THE POTENTIAL FOR ADDITIONAL SEVERE
STORMS AHEAD OF THE FRONT THIS MORNING. STORMS EARLY ON WILL
CONTINUE TO BE PRIMARILY ELEVATED IN NATURE BUT THERE IS CONCERN
THAT STORMS WILL BECOME ROOTED NEAR OR AT THE SURFACE ACROSS SOUTH
CENTRAL MISSOURI AS THE MORNING PROGRESSES. LATEST RUC ANALYSIS
DEPICTS DECREASING MIXED LAYER INHIBITION ACROSS FAR SOUTH CENTRAL
MISSOURI. THIS TREND WILL LIKELY CONTINUE AS RICHER LOW LEVEL
MOISTURE STREAMS NORTH. IF STORMS BECOME SURFACE BASED THE RISK
FOR DAMAGING WINDS AND ISOLATED TORNADOES WOULD INCREASE.
FOSTER
&&
.DISCUSSION...
/ISSUED 245 AM CST FRI MAR 2 2012/
THUNDERSTORMS WERE RAPIDLY DEVELOPING EARLY THIS MORNING ACROSS
PORTIONS OF SOUTHWEST AND CENTRAL MISSOURI NORTHEAST OF A SURFACE
LOW PRESSURE SYSTEM LOCATED IN NORTHEAST OKLAHOMA. STRONG WARM AIR
AND MOISTURE ADVECTION EAST OF THIS LOW OVER TOP THE BOUNDARY
LAYER WAS RESULTING RAPID DESTABILIZATION. MOST UNSTABLE CAPE OF
AROUND 1000 TO NEAR 2000 J/KG WAS NOSING INTO SOUTHERN MISSOURI.
THIS INSTABILITY COUPLED WITH STRONG DEEP LAYERED SHEAR WILL
SUPPORT STRONG TO SEVERE CONVECTION EARLY THIS MORNING. CONVECTIVE
MODE WILL BE ELEVATED SUPERCELLS WITH LARGE HAIL THE PRIMARY RISK. THIS
ACTIVITY WILL RACE EASTWARD.
WILL HAVE TO CLOSELY MONITOR CONVECTIVE TRENDS FARTHER SOUTH ALONG
THE ARKANSAS BORDER CLOSER TO THE SURFACE WARM FRONT. CONVECTION
COULD BECOME ROOTED NEAR THE SURFACE IN THIS AREA RESULTING IN A
GREATER RISK FOR DAMAGING WINDS
EXPECT ACTIVITY TO MOVE EAST OF THE AREA BY EARLY AFTERNOON IF NOT
EARLIER. COLDER AIR ADVECTION WILL DEVELOP DURING THE AFTERNOON AS
THE SURFACE LOW MOVES OFF TO THE EAST RESULTING STEADY IF NOT
FALLING TEMPERATURES. A CHILLY NIGHT IS IN STORE TONIGHT WITH MANY
AREAS NEAR THE FREEZING MARK. BELOW NORMAL TEMPERATURES ARE IN
STORE FOR SATURDAY AS AN UPPER TROUGH SWINGS ACROSS THE REGION.
MODERATING TEMPERATURES WILL BEGIN SUNDAY WITH A MORE SUBSTANTIAL
WARMING TREND BEGINNING MONDAY AS A SOUTHERLY FLOW DEVELOPS. WILL
HAVE TO MONITOR FIRE WEATHER CONDITIONS MONDAY GIVEN GUSTY
SOUTHERLY WINDS AND EXISTING DRY AIR MASS.
PRECIPITATION CHANCES RETURN BY THE MIDDLE OF NEXT WEEK AS THE
NEXT UPPER TROUGH APPROACHES.
&&
.AVIATION...
/ISSUED 610 AM CST FRI MAR 2 2012/
A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING BRINGING A
WIND SHIFT TO THE NORTHWEST AND A PERIOD OF MVFR CEILINGS.
SCATTERED SHOWERS AND THUNDERSTORMS WILL ALSO ACCOMPANY THE
FRONTAL PASSAGE. EXPECT IMPROVING FLIGHT CONDITIONS THIS AFTERNOON
BUT SURFACE WINDS WILL REMAIN GUSTY WITH FREQUENT GUSTS OVER 20
KTS. VFR CONDITIONS WILL PREVAIL TONIGHT INTO SATURDAY AS SURFACE
HIGH PRESSURE BUILDS INTO THE REGION.
FOSTER
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GLASGOW MT
221 PM MST FRI MAR 2 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY...
SYNOPTIC SET UP... A TROUGH IS TRANSITIONING FROM THE NORTHERN
PLAINS INTO THE GREAT LAKES. COLDEST AIR OF THE NORTHERN HEMISPHERE
SITS OVER THE NORTHERN HUDSON BAY. TO THE WEST A RIDGE EXTENDS
FROM UP THE COAST OF CALIFORNIA INTO CENTRAL BRITISH COLUMBIA.
ANOTHER LONG WAVE TROUGH IS MOVING OUT OF THE BEARING SEA INTO THE
GULF OF ALASKA.
THIS AFTERNOON AND EVENING... MONTANA WILL BE WEDGED IN NORTHWEST
FLOW BETWEEN THE EXITING TROUGH AND ENTERING RIDGE WHICH WILL
PROVIDE OCCASIONAL INSTABILITY. ACROSS THE SOUTHWEST SECTIONS OF
THE CWA THE HRRR MODEL ALONG WITH BOTH VERSIONS OF THE WRF ARE
POINTING TOWARDS AFTERNOON AND LATE EVENING INSTABILITY SHOWERS.
HAVE THROWN UP LIMITED POPS FOR THESE EVENTS BEING THAT THEY ARE A
BIT ON THE CHAOTIC SIDE. HOWEVER... AFTERNOON SHOWERS SEEM MORE
LIKELY DUE TO SIMILAR ACTIVITY TO YESTERDAY AFTERNOON WITH
CLEARING SKIES AND NO SNOW COVER.
SATURDAY MORNING THROUGH SUNDAY... UPPER LEVEL RIDGE TO THE WEST
WILL CONTINUE TO FILTER INTO THE REGION AND ASSERT INCREASING
DOMINANCE. 850 MB TEMPERATURES ARE ANTICIPATED TO RISE FROM RANGE
OF -9*C TO -2*C UP INTO THE POSITIVE SINGLE DIGITS CELCIUS. SKIES
WILL BE BE MOSTLY CLOUDY INITIALLY BUT SHOULD BE DECREASING OVER
THE NEXT FEW DAYS. A LEE SIDE MOUNTAIN TROUGH WILL SET UP AT THE
SURFACE TONIGHT AND BEGIN WAFFLING BACK AND FORTH ACROSS THE CWA
THROUGH SUNDAY. THIS WILL HELP TO TRIGGER INSTABILITY SHOWERS EACH
AFTERNOON AND EVENING. ON SUNDAY THE TROUGH WILL WANDER FAR ENOUGH
EASTWARD LATE IN THE DAY DUE TO DOWNSLOPE WARMING THAT IT WILL
EXIT THE AREA BRINGING TOTALLY DRY CONDITIONS. GAH
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
FAIR CONFIDENCE FOR THE EARLY PERIODS OF THE EXTENDED BUT DROPS
CONSIDERABLY BY MIDWEEK...WITH LOW CONFIDENCE INTO NEXT WEEKEND.
UPPER RIDGE OVER THE REGION MONDAY BREAKS DOWN AS AN UPPER TROF
PUSHES THROUGH THE PACIFIC NORTHWEST. STILL SOME QUESTIONS
REGARDING THIS TROF AND HOW MUCH IT DIGS SOUTHWEST AS IT PUSHES
THROUGH THE GREAT BASIN. STILL EXPECT SOME SNOW AS A STRONG COLD
FRONT MOVES ACROSS THE STATE MONDAY NIGHT/TUESDAY BUT HEAVIEST
AMOUNTS CURRENTLY EXPECTED IN SOUTHWEST MONTANA. REMAINDER OF THE
FORECAST TRENDED TOWARD CLIMO WHICH IS SIMILAR TO A MODEL BLEND
DUE TO THE SIGNIFICANT MODEL DIFFERENCES. EBERT
PREVIOUS LONG TERM DISCUSSION...THE EXTENDED FORECAST BEGINS WITH
UPPER RIDGING IN PLACE OVER THE REGION. THE ATMOSPHERE WARMS QUITE
NICELY ACROSS CENTRAL AND EASTERN MONTANA. LONG RANGE MODELS AGREE
ON THIS AND HAVE SHOWN THIS TREND FOR THE PAST FEW DAYS FOR ABOVE
NORMAL CONFIDENCE FOR SUNDAY NIGHT THROUGH WEDNESDAY MORNING. THEN
THE EC AND GFS HEAD OFF IN DIFFERENT DIRECTIONS...THEREFORE AFTER
WEDNESDAY MORNING THE FORECAST CONFIDENCE FACTOR DROPS OFF
SIGNIFICANTLY. GOING TO SIDE MORE WITH THE GFS FAMILY OVER THE EC.
BOTH THE GFS AND EC MODELS DO SHOW SOME ODDITIES FOR THIS TIME OF
YEAR. THE OVERALL AMOUNT OF CUT OFF LOWS IN EACH MODEL AROUND THE
NORTHERN HEMISPHERE LEADS TO A VERY COMPLICATED PATTERN FOR LARGE
SCALE MODELS TO GIVE A GOOD SOLUTION THAT FAR OUT. THE ENSEMBLES
DO NOT FAVOR EITHER MODEL OR GIVE AN IDEA OF WHICH DIRECTION TO
TAKE THE FORECAST THEREFORE OPTED FOR PERSISTENCE FROM WEDNESDAY
AND BEYOND.
MONDAY WILL HIGHLIGHT ABOVE NORMAL TEMPERATURES AND SPRING LIKE
WEATHER FOR THE REGION. TUESDAY A COLD FRONT WILL PUSH THROUGH
NORTHEAST MONTANA... THE FRONTAL TIMING HAS SPED UP THEREFORE DID
TAKE TEMPERATURES DOWN A FEW DEGREES FOR THE EARLIER FRONTAL
PASSAGE. WEDNESDAY AND BEYOND... SLOW WARMING TREND TO KEEP WITH
THE PERSISTENCE TREND. PROTON
&&
.AVIATION...
GENERALLY EXPECT VFR CONDITIONS ALTHOUGH A FEW SNOW SHOWERS MAY
MOVE ACROSS THE REGION TONIGHT AND SATURDAY. FLIGHT CONDITIONS
WITH THE SNOW SHOWERS COULD DROP TO MVFR OR POSSIBLY IFR LEVELS.
RAE
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
931 AM MST FRI MAR 2 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY...
LOW PRESSURE CONTINUES TO MOVE EAST OVER THE NORTHERN PLAINS AND
LEAVE MONTANA BEHIND. HOWEVER THE PRESSURE GRADIENT BEHIND THIS STORM
SYSTEM HAS LEFT OVER STRONG ENOUGH WINDS TO CREATE GUSTS AND SOME
DRIFTING WITH VISIBILITY PROBLEMS THROUGH THE MORNING HOURS. HIGH
PRESSURE SITS OFF TO THE NORTH AND WEST AND WILL BEGIN MOVING INTO
THE REGION DURING THE AFTERNOON HOURS. THIS SHOULD REDUCE WINDS
OVER ALL. A STALLED BOUNDARY THAT IS FALLING APART IS ALSO
HELPING TO PROVIDE ENOUGH OF A FOCAL MECHANISM TO CONTINUE
PRODUCING LIGHT SNOW ACROSS SOUTHEASTERN SECTIONS OF THE CWA.
ACROSS THE SOUTHWEST SECTIONS OF THE CWA THE HRRR MODEL ALONG WITH
BOTH VERSIONS OF THE WRF ARE POINTING TOWARDS AFTERNOON AND LATE
EVENING INSTABILITY SHOWERS. HAVE THROWN UP LIMITED POPS FOR THESE
EVENTS BEING THAT THEY ARE A BIT ON THE CHAOTIC SIDE. HOWEVER...
AFTERNOON SHOWERS SEEM MORE LIKELY DUE TO SIMILAR ACTIVITY TO
YESTERDAY AFTERNOON WITH CLEARING SKIES AND NO SNOW COVER. GAH
PREVIOUS SHORT TERM DISCUSSION...
WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD REVEALS A VERY ACTIVE
WEATHER PATTERN ACROSS THE CONUS. A BROAD LARGE SCALE UPPER TROUGH
OVER THE ROCKY MOUNTAIN AND CENTRAL STATES IS SPREADING SCATTERED
SNOW SHOWERS ACROSS THOSE AREAS. ON THE OTHER SIDE...EASTWARD
AHEAD OF THE TROUGH...THE STAGE IS SET FOR A MODERATE RISK OF
SEVERE THUNDERSTORMS AND TORNADOES ACROSS THE OHIO RIVER VALLEY
AND SOUTHWARD THROUGH KENTUCKY AND TENNESSEE. EVEN NOW...A FEW
THUNDERSTORMS ARE TRYING TO BREAK OUT IN THAT GENERAL REGION. AN
UPPER LEVEL RIDGE IS MOVING NEAR THE WEST COAST.
FORECAST CHALLENGES INCLUDE THE CURRENT WINTER WEATHER ADVISORY
OVER OUR NORTHEAST ZONES.
EVEN THOUGH RADAR RETURNS ARE QUITE LIGHT AND BARELY MODERATE AT
TIMES...THERE SEEMS TO BE ENOUGH OBSERVATIONAL SUPPORT FOR
CONTINUING THE WINTER WEATHER ADVISORY THROUGH THE MORNING HOURS.
DIMINISHING RADAR RETURNS FURTHER AWAY FROM THE RADAR ARE MOST
LIKELY REPRESENTATIVE OF THE RADAR BEAM CUTTING ABOVE THE SNOW
FALLING AT THE LOWEST LEVELS. CASE IN POINT...WILLISTON IS AT THE
EDGE OF VERY LIGHT RETURNS OR NONE AT ALL...YET THE OBSERVATION
STILL RECORDS SNOW FALL. WINDS FROM THE NORTHWEST ARE HOLDING
QUITE STEADY FROM 15G25 KT TO 20G30 KT. EXPECT THE SNOWFALL TO
BECOME MORE SCATTERED IN NATURE TOWARD THE LATER MORNING HOURS.
THE ADVISORY IS CONSEQUENTLY SLATED TO EXPIRE BY 18Z TODAY.
THE REMAINDER OF THE SHORT TERM FORECAST FOR OUR CWA FALLS UNDER A
STEADY AND TIGHTLY PACKED NORTHWEST FLOW ALOFT AS A STRONG UPPER
LEVEL JET ARCS OVER THE ROCKY MOUNTAINS AND CLIPS THE CORNER OF
NORTHEAST MONTANA.
SATURDAY THROUGH SUNDAY...INCREASING INFLUENCE FROM THE
APPROACHING AND BUILDING WESTERN RIDGE PUSHES INTO THE CWA FROM
THE WEST AND SOUTHWEST. LARGE SCALE FORCING FOR ASCENT SHOWS THAT
THERE MAY BE A VERY SMALL AND SUBTLE EMBEDDED DISTURBANCE PACKED
WITHIN THE NORTHWEST FLOW ALOFT WHICH MAY RESULT IN A FEW
SCATTERED SNOW SHOWERS ON SATURDAY...BUT DO NOT EXPECT IT TO BE OF
ANY GREAT SIGNIFICANCE AT THIS TIME. BMICKELSON
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
THE EXTENDED FORECAST BEGINS WITH UPPER RIDGING IN PLACE OVER THE
REGION. THE ATMOSPHERE WARMS QUITE NICELY ACROSS CENTRAL AND
EASTERN MONTANA. LONG RANGE MODELS AGREE ON THIS AND HAVE SHOWN
THIS TREND FOR THE PAST FEW DAYS FOR ABOVE NORMAL CONFIDENCE FOR
SUNDAY NIGHT THROUGH WEDNESDAY MORNING. THEN THE EC AND GFS HEAD
OFF IN DIFFERENT DIRECTIONS...THEREFORE AFTER WEDNESDAY MORNING
THE FORECAST CONFIDENCE FACTOR DROPS OFF SIGNIFICANTLY. GOING TO
SIDE MORE WITH THE GFS FAMILY OVER THE EC. BOTH THE GFS AND EC
MODELS DO SHOW SOME ODDITIES FOR THIS TIME OF YEAR. THE OVERALL
AMOUNT OF CUT OFF LOWS IN EACH MODEL AROUND THE NORTHERN
HEMISPHERE LEADS TO A VERY COMPLICATED PATTERN FOR LARGE SCALE
MODELS TO GIVE A GOOD SOLUTION THAT FAR OUT. THE ENSEMBLES DO NOT
FAVOR EITHER MODEL OR GIVE AN IDEA OF WHICH DIRECTION TO TAKE THE
FORECAST THEREFORE OPTED FOR PERSISTENCE FROM WEDNESDAY AND BEYOND.
MONDAY WILL HIGHLIGHT ABOVE NORMAL TEMPERATURES AND SPRING LIKE
WEATHER FOR THE REGION. TUESDAY A COLD FRONT WILL PUSH THROUGH
NORTHEAST MONTANA... THE FRONTAL TIMING HAS SPED UP THEREFORE DID
TAKE TEMPERATURES DOWN A FEW DEGREES FOR THE EARLIER FRONTAL
PASSAGE. WEDNESDAY AND BEYOND... SLOW WARMING TREND TO KEEP WITH
THE PERSISTENCE TREND. PROTON
&&
.AVIATION...
FLIGHT CONDITIONS WILL BE IMPROVING THROUGH THE MORNING AS THE
AREA OF SNOW MOVES TO THE SOUTHEAST. MVFR CONDITIONS WILL LINGER
THE LONGEST IN THE YELLOWSTONE VALLEY. RAE
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR CENTRAL
AND SOUTHERN VALLEY...WESTERN ROOSEVELT...MCCONE...RICHLAND...
DAWSON...WIBAUX...EASTERN ROOSEVELT.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
850 PM CST SAT MAR 3 2012
.UPDATE...
ISSUED A WIND ADVISORY FOR SUNDAY FOR NORTHEAST NEBRASKA AS WELL
AS OUR IOWA COUNTIES. THE CLIPPER SYSTEM THAT IS CURRENTLY
ANALYZED MOVING OUT OF SOUTHERN SASKATCHEWAN AND INTO NORTHEAST
MONTANA THIS EVENING HAS THE POTENTIAL TO BECOME A STRONG WIND
PRODUCING SYSTEM. WIND GUSTS WITH THIS SYSTEM ARE ALREADY
IMPRESSIVE...WITH A PEAK WIND OF 51 KNOTS AT LEWISTOWN MONTANA.
NEW 00Z NAM HAS INCREASED THE 850 MB WIND SPEEDS WITH THIS CLIPPER
SYSTEM AS IT MOVES THROUGH THE PLAINS ON SUNDAY. FAST MOVING
NORTHWEST FLOW WILL ACT TO PUSH THE FRONT THROUGH QUICKLY BUT ALSO
WILL PROVIDE UNIDIRECTIONAL NORTHWEST WINDS FROM THE BOUNDARY
LAYER ALL THE WAY UP...WITH A 300 MB FORECAST JET CORE OF 140
KNOTS OVER NORTHEAST NEBRASKA AND NORTHWEST IOWA 18Z-21Z SUNDAY.
THIS WILL PROVIDE GOOD MOMENTUM TRANSPORT TO THE SURFACE...AIDED
BY A WELL MIXED AND DEEP BOUNDARY LAYER AS WELL AS DESCENDING
VERTICAL MOTION.
FOR NOW WE HAVE EXCLUDED AREAS OF SOUTHEAST NEBRASKA MAINLY ALONG
AND SOUTH OF THE PLATTE RIVER AND THE OMAHA METRO AREA BECAUSE
THESE AREAS ARE A BIT REMOVED FROM THE STRONGER GRADIENT AND
HIGHER WINDS ALOFT. WE WILL EVALUATE THIS OVERNIGHT AND MAY
CONSIDER EXPANDING THE ADVISORY AREA IF NECESSARY.
NIETFELD
&&
.PREV DISCUSSION... /ISSUED 603 PM CST SAT MAR 3 2012/
AVIATION...
MAIN AVIATION CONCERNS WILL COME WITH THE PASSAGE OF A FAST MOVING
COLD FRONT ON SUNDAY. EXPECT THE FRONT TO PASS THROUGH KOFK AROUND
14Z...KLNK AROUND 15Z... AND KOMA AROUND 17Z. FAIRLY STRONG
NORTHWEST WINDS WILL OCCUR BEHIND THE FRONT...WITH SUSTAINED
WINDS OF AT LEAST 20 KNOTS AND GUSTS TO 35 KNOTS ESPECIALLY IN THE
AFTERNOON. WE EXPECT VFR CONDITIONS THROUGHOUT THE TAF PERIOD.
HOWEVER KOFK MAY SEE SOME LIGHT SNOW IN THE 09Z-12Z PERIOD JUST
PRIOR TO THE COLD FRONTAL PASSAGE. CIGS COULD DROP AS LOW AS
OVC015 DURING THAT TIME AS WELL.
NIETFELD
PREV DISCUSSION... /ISSUED 245 PM CST SAT MAR 3 2012/
SHORT TERM...TONIGHT THROUGH TUESDAY.
LIGHT SPRINKLES OR FLURRIES SHOWING UP ON RADAR AT 20Z WEST OF A
KOLU TO KLNK LINE. RUC FORECAST SOUNDINGS INDICATE SOME MID LEVEL
SATURATION AND INSTABILITY FOR A TIME THIS AFTERNOON BEFORE
DISSIPATING WITH LOSS OF HEATING.
ANOTHER CHANCE OF LIGHT PRECIP COMES INTO THE PICTURE LATE TONIGHT
AS A FAST MOVING CLIPPER SYSTEM DROPS INTO THE NORTHERN PLAINS
THEN CONTINUES INTO THE MID MISSISSIPPI VALLEY ON SUNDAY. NAM AND
GFS SHOW A SIMILAR TRACK IN TAKING THE WAVE ACROSS CENTRAL IOWA
WHILE THE ECMWF IS A BIT FURTHER WEST ALONG THE NEBRASKA IOWA
BORDER. CURRENT FORECAST WILL FOLLOW THE MORE EASTERLY TRACK AND
BRING SOME SMALL POPS INTO NORTHEAST NEBRASKA LATE TONIGHT WITH
LIGHT SNOW OR FLURRIES JUST EAST OF THE AREA SUNDAY MORNING.
NORTHWEST WINDS WILL ALSO PICK UP ON THE BACKSIDE OF THIS SYSTEM
SUNDAY WITH ADVISORY LEVEL WINDS INDICATED FOR SUNDAY AFTERNOON
ACROSS ALL BUT THE FAR SOUTHERN PART OF THE CWA. WILL NOT ISSUE
ANY HEADLINES AT THIS TIME AND LET LATER SHIFT REEVALUATE TRACK OF
THE SYSTEM IN NEXT MODEL RUN.
WARMER AIR RETURNS MONDAY INTO TUESDAY AS RIDGE MOVES OVER THE
REGION AND FLATTENS AHEAD OF THE NEXT UPPER WAVE DROPPING INTO THE
WESTERN CONUS. MUCH ABOVE NORMAL TEMPERATURES EXPECTED ON TUESDAY
WITH HIGHS APPROACHING 70 IF MODELS MAINTAIN TIMING OF COLD FRONT
COMING INTO THE AREA LATE ON TUESDAY IN FUTURE RUNS.
LONG TERM...TUESDAY NIGHT THROUGH SATURDAY.
THE MAIN CONCERN IN THIS PERIOD IS THE CHANCE OF PRECIPITATION FROM
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. LATEST MODELS WERE IN GOOD
AGREEMENT WITH THE LARGE SCALE PATTERN AT THE BEGINNING OF THIS
PERIOD...SHOWING A 500 MB TROUGH OVER THE ROCKIES. ENERGY WITH THIS
TROUGH SPLITS INTO TWO PIECES. ONE SHOULD AFFECT THE NORTHERN PLAINS
AND THE OTHER BRIEFLY BECOMES A CLOSED LOW OVER THE FOUR CORNERS
REGION. SOME LIGHT PRECIPITATION IS POSSIBLE ALONG AND BEHIND A COLD
FRONT THAT WILL PUSH SOUTHEAST THROUGH THE REGION TUESDAY NIGHT.
GFS SEEMS TO HAVE TRENDED TOWARD YESTERDAYS ECMWF SOLUTION...AND THE
12Z GFS SHOWED 850 MB DEWPOINTS 0 TO 6 DEGREES C AHEAD OF THE FRONT.
LAPSE RATES ARE DECENT...AND 850 MB LIFTED INDICES DROP TO NEAR ZERO
TUESDAY NIGHT...SO SOME THUNDER APPEARS POSSIBLEIN SOUTHEAST
NEBRASKA. CHANCES INCREASE FOR WEDNESDAY AND POTENTIAL RAINFALL
AMOUNTS ARE HIGHER...MAINLY ACROSS SOUTHEAST NEBRASKA AND SOUTHWEST
IOWA.
EXPECT DRY CONDITIONS THURSDAY THROUGH SATURDAY...WITH HIGHS MOSTLY
IN THE 40S TO LOWER 50S.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM NOON TO 4 PM CST SUNDAY FOR NEZ015-034-045.
WIND ADVISORY FROM 10 AM TO 4 PM CST SUNDAY FOR NEZ011-012-
016>018-031>033.
IA...WIND ADVISORY FROM NOON TO 4 PM CST SUNDAY FOR IAZ043-055-056-
069-079-080-090-091.
&&
$$
NIETFELD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
603 PM CST SAT MAR 3 2012
.AVIATION...
MAIN AVIATION CONCERNS WILL COME WITH THE PASSAGE OF A FAST MOVING
COLD FRONT ON SUNDAY. EXPECT THE FRONT TO PASS THROUGH KOFK AROUND
14Z...KLNK AROUND 15Z... AND KOMA AROUND 17Z. FAIRLY STRONG
NORTHWEST WINDS WILL OCCUR BEHIND THE FRONT...WITH SUSTAINED
WINDS OF AT LEAST 20 KNOTS AND GUSTS TO 35 KNOTS ESPECIALLY IN THE
AFTERNOON. WE EXPECT VFR CONDITIONS THROUGHOUT THE TAF PERIOD.
HOWEVER KOFK MAY SEE SOME LIGHT SNOW IN THE 09Z-12Z PERIOD JUST
PRIOR TO THE COLD FRONTAL PASSAGE. CIGS COULD DROP AS LOW AS
OVC015 DURING THAT TIME AS WELL.
NIETFELD
&&
.PREV DISCUSSION... /ISSUED 245 PM CST SAT MAR 3 2012/
SHORT TERM...TONIGHT THROUGH TUESDAY.
LIGHT SPRINKLES OR FLURRIES SHOWING UP ON RADAR AT 20Z WEST OF A
KOLU TO KLNK LINE. RUC FORECAST SOUNDINGS INDICATE SOME MID LEVEL
SATURATION AND INSTABILITY FOR A TIME THIS AFTERNOON BEFORE
DISSIPATING WITH LOSS OF HEATING.
ANOTHER CHANCE OF LIGHT PRECIP COMES INTO THE PICTURE LATE TONIGHT
AS A FAST MOVING CLIPPER SYSTEM DROPS INTO THE NORTHERN PLAINS
THEN CONTINUES INTO THE MID MISSISSIPPI VALLEY ON SUNDAY. NAM AND
GFS SHOW A SIMILAR TRACK IN TAKING THE WAVE ACROSS CENTRAL IOWA
WHILE THE ECMWF IS A BIT FURTHER WEST ALONG THE NEBRASKA IOWA
BORDER. CURRENT FORECAST WILL FOLLOW THE MORE EASTERLY TRACK AND
BRING SOME SMALL POPS INTO NORTHEAST NEBRASKA LATE TONIGHT WITH
LIGHT SNOW OR FLURRIES JUST EAST OF THE AREA SUNDAY MORNING.
NORTHWEST WINDS WILL ALSO PICK UP ON THE BACKSIDE OF THIS SYSTEM
SUNDAY WITH ADVISORY LEVEL WINDS INDICATED FOR SUNDAY AFTERNOON
ACROSS ALL BUT THE FAR SOUTHERN PART OF THE CWA. WILL NOT ISSUE
ANY HEADLINES AT THIS TIME AND LET LATER SHIFT REEVALUATE TRACK OF
THE SYSTEM IN NEXT MODEL RUN.
WARMER AIR RETURNS MONDAY INTO TUESDAY AS RIDGE MOVES OVER THE
REGION AND FLATTENS AHEAD OF THE NEXT UPPER WAVE DROPPING INTO THE
WESTERN CONUS. MUCH ABOVE NORMAL TEMPERATURES EXPECTED ON TUESDAY
WITH HIGHS APPROACHING 70 IF MODELS MAINTAIN TIMING OF COLD FRONT
COMING INTO THE AREA LATE ON TUESDAY IN FUTURE RUNS.
LONG TERM...TUESDAY NIGHT THROUGH SATURDAY.
THE MAIN CONCERN IN THIS PERIOD IS THE CHANCE OF PRECIPITATION FROM
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. LATEST MODELS WERE IN GOOD
AGREEMENT WITH THE LARGE SCALE PATTERN AT THE BEGINNING OF THIS
PERIOD...SHOWING A 500 MB TROUGH OVER THE ROCKIES. ENERGY WITH THIS
TROUGH SPLITS INTO TWO PIECES. ONE SHOULD AFFECT THE NORTHERN PLAINS
AND THE OTHER BRIEFLY BECOMES A CLOSED LOW OVER THE FOUR CORNERS
REGION. SOME LIGHT PRECIPITATION IS POSSIBLE ALONG AND BEHIND A COLD
FRONT THAT WILL PUSH SOUTHEAST THROUGH THE REGION TUESDAY NIGHT.
GFS SEEMS TO HAVE TRENDED TOWARD YESTERDAYS ECMWF SOLUTION...AND THE
12Z GFS SHOWED 850 MB DEWPOINTS 0 TO 6 DEGREES C AHEAD OF THE FRONT.
LAPSE RATES ARE DECENT...AND 850 MB LIFTED INDICES DROP TO NEAR ZERO
TUESDAY NIGHT...SO SOME THUNDER APPEARS POSSIBLEIN SOUTHEAST
NEBRASKA. CHANCES INCREASE FOR WEDNESDAY AND POTENTIAL RAINFALL
AMOUNTS ARE HIGHER...MAINLY ACROSS SOUTHEAST NEBRASKA AND SOUTHWEST
IOWA.
EXPECT DRY CONDITIONS THURSDAY THROUGH SATURDAY...WITH HIGHS MOSTLY
IN THE 40S TO LOWER 50S.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
631 AM EST FRI MAR 2 2012
.SYNOPSIS...
A STATIONARY FRONT OVER SOUTHEASTERN NORTH CAROLINA WILL LIFT NORTH
AS A WARM FRONT THIS MORNING. A STRONG COLD FRONT WILL BRING
THUNDERSTORMS SATURDAY AFTERNOON AND EVENING. COOLER AND DRIER HIGH
PRESSURE WILL BUILD INTO THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...INCOMING CONVECTIVE LINE IS QUITE A BIT
STRONGER THAN INITIALLY THOUGHT SEVERAL HOURS AGO. NEARLY DRY
ADIABATIC LAPSE RATE SHOWN ON THE LATEST RUC SOUNDINGS BETWEEN
700-500 MB IS FUELING INTENSE UPDRAFTS IN THE SC SQUALL LINE. SOME
OF THE CELLS SOUTH OF CHARLOTTE HAVE EXHIBITED DEVIANT MOTION...
CELL SPLITS...ANTICYCLONIC ROTATION...AND INTENSE HAIL CORES WITH
THREE-BODY SCATTER SPIKES. WOW! OLD VIL OF THE DAY CALCULATIONS FOR
3/4 INCH HAIL (BASED ON 400/500 MB TEMPS) IS 36 KG/M^2. OUR LOCAL
STUDY FOR SEVERE HAIL SHOWS 50 DBZ AT 29000 FT OR HIGHER WILL
PROBABLY PRODUCE ONE-INCH HAIL.
I`VE INCREASED POPS INTO THE 60-80 PERCENT RANGE ACROSS THE SC PEE
DEE REGION INTO LUMBERTON...AND ALSO INCREASED POPS IN THE CHANCE
RANGE ALL THE WAY DOWN TO THE COAST. NO OTHER SIGNIFICANT CHANGES.
PREVIOUS DISCUSSION FOLLOWS...
A NEARLY STATIONARY FRONT EXTENDING EAST-WEST FROM AROUND NEW BERN
TO NEAR KINSTON...TO FAYETTEVILLE...SOUTHERN PINES...WADESBORO AND
MONROE...WILL MOVE LITTLE THROUGH DAYBREAK. THE BOUNDARY WILL JUMP
NORTH LATER THIS MORNING WITH SOUTHERLY WINDS BRINGING SUBTROPICAL
MOISTURE ACROSS ALL OF NORTH AND SOUTH CAROLINA. A WEAK UPPER
DISTURBANCE WILL CROSS THE AREA LATE THIS MORNING JUST BEHIND THE
RETREATING FRONT BRINGING THE POTENTIAL FOR SCATTERED SHOWERS OR
THUNDERSTORMS TO MAINLY THE INLAND PORTIONS OF THE CAROLINAS. THE
DISTURBANCE WILL HELP COOL THE 700 MB TEMP JUST ENOUGH TO ERODE A
CONVECTIVE CAP ALLOWING SOME ELEVATED CONVECTION TO OCCUR. THE LAST
FEW RUNS OF THE HRRR HIGH-RESOLUTION MESOSCALE MODEL SHOW A
CONVECTIVE CHARACTER TO FORECAST PRECIPITATION ECHOES ACROSS THE
CENTRAL CAROLINAS IN THE 14-17Z TIME FRAME. PRECIPITATION CHANCES
WILL DROP TO LESS THAN 10 PERCENT BY MID-AFTERNOON AS THE
DISTURBANCES SWINGS BY TO THE NORTHEAST.
TONIGHT WARM AND MOIST SOUTH-SOUTHWESTERLY FLOW WILL CONTINUE OUT
AHEAD OF A STRONG COLD FRONT ADVANCING STEADILY EASTWARD. SHOWERS
AND THUNDERSTORMS ALONG THE FRONT WILL REACH THE PEE DEE REGION
LATE...PROBABLY AROUND 4 AM...AND MAY REACH THE COAST AROUND SUNRISE
SATURDAY MORNING. ALTHOUGH THIS IS THE SAME SYSTEM ANTICIPATED TO
BRING A LARGE SEVERE WEATHER OUTBREAK TO PORTIONS OF THE MID-SOUTH
AND TENNESSEE/OHIO VALLEYS TODAY...THE SYNOPTIC SITUATION IS NOT
QUITE AS FAVORABLE THIS FAR EAST SINCE THE PARENT UPPER DISTURBANCE
WILL BE SHEARING OUT TO THE NORTHEAST. THE LATE-NIGHT TIMING COUPLED
WITH COLD NEARSHORE OCEAN WATER TEMPERATURES ARE ALSO UNFAVORABLE
FACTORS FROM THE STANDPOINT OF MAINTAINING STRONG SURFACE-BASED
CONVECTION.
HIGHS TODAY SHOULD RANGE FROM THE MID 70S ACROSS MOST OF
SOUTHEASTERN NORTH CAROLINA...TO NEAR 80 ACROSS THE PEE DEE REGION
OF SOUTH CAROLINA. MUCH LIKE YESTERDAY WINDS BLOWING ONSHORE FROM
THE COLD NEARSHORE OCEAN WILL KEEP TEMPERATURES A GOOD 10-15 DEGREES
COLDER THAN INLAND AREAS. TONIGHT LOWS SHOULD ONLY FALL INTO THE
LOWER 60S WITH A STEADY SOUTH-SOUTHWEST WIND CONTINUING.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...LATEST FORECAST SOUNDINGS SUGGEST THIS
WEEKENDS RAIN EVENT COULD BRING SIGNIFICANT RAINFALL TO THE
REGION. YESTERDAY SOUNDINGS WERE SHOWING A BRIEF PERIOD THE
ATMOSPHERE WAS NEARLY SATURATED. HOWEVER THE LATEST GUIDANCE IS
MUCH WETTER. IT NOW LOOKS LIKE THE FRONT WILL DROP INTO THE AREA
SAT MORNING THEN STALL AS THE FRONT ENDS UP LAYING PARALLEL TO THE
FLOW ALOFT. EARLIER SOLUTIONS HAD THE FRONT STALLING OFF THE
COAST...A SOLUTION WHICH STILL COULD COME TO PASS. SPC HAS PUT
MOST OF THE FORECAST AREA INTO THE DAY 2 SLIGHT RISK...BUT THREAT
APPEARS LIMITED. FIRST THERE WILL BE CONSIDERABLE CLOUD COVER
ACROSS THE AREA SAT...LIMITING DIURNAL HEATING. MID LEVEL LAPSE
RATES ARE MARGINAL AT BEST MOSTLY UNDER 6C/KM. LOW LEVEL JETTING
IN FORECAST SOUNDINGS IS WEAKER THAN IN PREVIOUS RUNS. STRONG
SOUTHWEST FLOW WILL PUSH TEMPERATURES INTO THE LOW 70S DESPITE
CLOUDS AND PRECIP.
SURFACE WAVE DEVELOPS ALONG THE FRONT LATE SAT INTO SAT NIGHT SOUTH
OF THE AREA THEN TRACKS NORTHEAST ALONG THE FRONT BRINGING ANOTHER
ROUND OF SHOWERS AND ISOLATED THUNDERSTORMS TO THE REGION SAT NIGHT
INTO SUN. 5H TROUGH MOVES INTO THE AREA EARLY SUN...PUSHING THE
FRONT...ALONG WITH ANY ASSOCIATED PRECIP...OFF THE COAST. ARRIVAL
TIME OF COLD AIR SAT NIGHT WILL BE KEY TO DETERMINING HOW LOW TEMPS
DROP. SOME LIGHT PRECIP MAY LINGER INTO SUN MORNING BUT OVERALL SUN
SHOULD BE DRY WITH SKIES CLEARING DURING THE DAY. COLD ADVECTION
WILL KEEP TEMPS BELOW CLIMO SUN AND SUN NIGHT. HOWEVER BOUNDARY
LAYER REMAINS WELL MIXED SUN NIGHT...PREVENT TEMPS FROM DROPPING
BELOW FREEZING.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 AM FRIDAY...5H TROUGH WILL BE IN THE PROCESS OF LIFTING
NORTHEAST AT THE START OF THE PERIOD. DRY COLD FRONT MOVES ACROSS
THE REGION EARLY MON BUT ALL IT WILL BRING IS A REINFORCING SHOT
OF COOLER AIR LATER IN THE DAY. INCREASE IN CLOUD COVER MON
ASSOCIATED THIN LAYER OF MOISTURE BETWEEN 850 AND 750 MB IN
CONJUNCTION WITH A SHORTWAVE ROTATING AROUND THE BASE OF THE UPPER
TROUGH. PRECIP IS NOT AN ISSUE AS MOISTURE IS NOT NEARLY DEEP
ENOUGH. REMAINDER OF THE PERIOD WILL REMAIN DRY WITH VERY LITTLE
IN THE WAY OF CLOUDS. TEMPERATURES BOTTOM OUT MON NIGHT INTO
TUE...WITH LOWS MON NIGHT AT OR BELOW FREEZING AND HIGHS TUE IN
THE MID 50S. ELONGATED RIDGE AXIS SHIFTS OFFSHORE TUE NIGHT WITH
LIGHT ONSHORE FLOW DEVELOPING. ECMWF/GFS BOTH SHOW WEAK COASTAL
TROUGH DEVELOPING TUE NIGHT BUT BOTH MOVE THIS FEATURE ONSHORE
WED. AT THIS POINT TROUGH LOOKS TOO WEAK TO SUPPORT PRECIP. 5H
RIDGE BUILDS OVER THE SOUTHEAST WED THEN STRENGTHENS FOR THU.
TEMPERATURES RETURN CLOSE TO CLIMO WED/WED NIGHT...RUNNING NEAR TO
SLIGHTLY ABOVE CLIMO THU/THU NIGHT.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...A FRONTAL BOUNDARY LOCATED FROM NEAR LBT TO NORTH OF ILM
WILL LIFT BACK TO THE NORTH TODAY. HIGHLY VARIABLE FLIGHT CONDITIONS
EXPECTED THROUGH 14-15Z THIS MORNING WITH RAPID CHANGES FROM LIFR TO
MVFR/VFR DUE TO FOG AND SHOWERS/THUNDERSTORMS. CONFIDENCE IS
MODERATE TO HIGH FLIGHT CONDITIONS WILL IMPROVE TO MVFR OR HIGHER BY
AFTERNOON. THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS THIS
MORNING...MOST LIKELY FLO/LBT WITH CONVECTION GRADUALLY WEAKENING AS
THE IT NEARS THE COASTAL TERMINALS. BY AFTERNOON EXPECT SHOWER
POTENTIAL TO WANE WITH VFR CONDITIONS HIGHLY LIKELY AS CLOUD COVER
DECREASES. AS THE PRESSURE GRADIENT TIGHTENS EXPECT SOUTH TO
SOUTHWEST WIND GUSTS TO 20-25 KNOTS TO DEVELOP.
BY LATE AFTERNOON AND EVENING EXPECT WIND GUSTS TO SUBSIDE BUT
SUSTAINED WINDS OF 10-15 KNOTS WILL PERSIST DURING THE EVENING AND
OVERNIGHT AS A COLD FRONT APPROACHES. VFR IS EXPECTED THIS
EVENING...EXCEPT AT CRE WHERE CONFIDENCE IS HIGH SEA FOG WILL LOWER
CEILINGS TO LIFR. AFTER 10Z MVFR CEILINGS WILL BECOME LIKELY AT
FLO/LBT AS SHOWERS AND THUNDERSTORMS APPROACH FROM THE WEST.
EXTENDED OUTLOOK...THUNDERSTORMS/TEMPO IFR SATURDAY INTO SUNDAY
MORNING. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...NO SIGNIFICANT CHANGES WITH THIS EARLY MORNING
UPDATE. PREVIOUS DISCUSSION FOLLOWS...
A FRONT STALLED OUT ACROSS INLAND SOUTHERN NORTH CAROLINA WILL
RETREAT FARTHER NORTH TODAY...OPENING UP THE FLOODGATES FOR
SUSTAINED SOUTHERLY WINDS TODAY INTO TONIGHT. MUCH LIKE
YESTERDAY...THE HUMID SUBTROPICAL AIRMASS WILL BECOME CHILLED BY ITS
JOURNEY ACROSS THE COLD NEARSHORE OCEAN WATERS AND COULD YIELD LOW
STRATUS CLOUDS OR PATCHY SEA FOG AT TIMES. SOUTH WINDS WILL INCREASE
TO AROUND 15 KT THIS AFTERNOON...AND THEN TO 20 KNOTS TONIGHT. THESE
SURFACE WIND SPEEDS SHOULD BE LIMITED BY A STABLE BOUNDARY LAYER
FROM THE COLD UNDERLYING OCEAN SURFACE. GO 30-40 MILES OFFSHORE
WHERE WATER TEMPERATURES ARE WARMER...AND WIND SPEEDS WILL EASILY BE
ANOTHER 5-10 KNOTS HIGHER WITH MUCH ROUGHER SEAS TOO.
THE FRYING PAN SHOALS BUOY IS REPORTING 4-5 FT SEAS OVER THE PAST
COUPLE OF HOURS. SEAS WITHIN 20 MILES OF SHORE SHOULD AVERAGE 3 FT
TODAY...BUILDING TO 4-6 FT OVERNIGHT...HIGHEST IN THE FRYING PAN
SHOALS VICINITY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...INCREASING SOUTHWEST FLOW AHEAD OF A STRONG
COLD FRONT WILL REQUIRE A SCA HEADLINE AT SOME POINT SAT. SPEEDS
START OUT 15 TO 20 KT BUT INCREASE TO 20 TO 25 KT SAT
AFTERNOON/EVENING AS GRADIENT TIGHTENS UP. PROLONGED SOUTHWEST
FLOW WILL PROBABLY BUILD SEAS OVER 6 FT BEFORE SPEEDS REACH 25 KT.
DURATION OF SCA MAY END UP BEING RATHER BRIEF. THE FRONT WILL
STALL ALONG OR JUST OFF THE COAST WITH AN ILL-DEFINED PRESSURE
PATTERN KEEPING WINDS VARIABLE WITH SPEEDS BETWEEN 10 AND 15 KT.
WEAK WAVE OF LOW PRESSURE MOVES NORTHEAST ALONG THE STALLED
BOUNDARY PASSING EAST OF THE WATERS LATE SAT NIGHT. GRADIENT
TIGHTENS UP SUN AS THE LOW/FRONT MOVES EAST-NORTHEAST AND COLD
ADVECTION ARRIVES. STRONG OFFSHORE FLOW MAY WARRANT A BRIEF
DURATION HEADLINE SUN NIGHT INTO MON.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 330 AM FRIDAY...OFFSHORE FLOW WILL SLOWLY DECREASE ON MON AS
ELONGATED HIGH PRESSURE OVER THE MISSISSIPPI VALLEY SHIFTS EAST.
SPEEDS START OUT 15 TO 20 KT FROM THE WEST-NORTHWEST BUT DROP TO
10 TO 15 KT LATE MON NIGHT INTO TUE AS THEY BACK TO NORTH-
NORTHEAST. SEAS RUNNING 3 TO 5 FT DUE TO STRONG OFFSHORE FLOW WILL
SUBSIDE TO 2 TO 4 FT LATE MON INTO MON NIGHT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
400 AM EST FRI MAR 2 2012
.SYNOPSIS...
A STATIONARY FRONT WILL LIFT NORTH AS A WARM FRONT THIS
MORNING. A STRONG COLD FRONT WILL BRING THUNDERSTORMS SATURDAY
AFTERNOON AND EVENING. COOLER AND DRIER HIGH PRESSURE WILL BUILD
INTO THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM FRIDAY...A NEARLY STATIONARY FRONT EXTENDING EAST-WEST
FROM AROUND NEW BERN TO NEAR KINSTON...TO FAYETTEVILLE...SOUTHERN
PINES...WADESBORO AND MONROE...WILL MOVE LITTLE THROUGH DAYBREAK.
THE BOUNDARY WILL JUMP NORTH LATER THIS MORNING WITH SOUTHERLY WINDS
BRINGING SUBTROPICAL MOISTURE ACROSS ALL OF NORTH AND SOUTH
CAROLINA. A WEAK UPPER DISTURBANCE WILL CROSS THE AREA LATE THIS
MORNING JUST BEHIND THE RETREATING FRONT BRINGING THE POTENTIAL FOR
SCATTERED SHOWERS OR THUNDERSTORMS TO MAINLY THE INLAND PORTIONS OF
THE CAROLINAS. THE DISTURBANCE WILL HELP COOL THE 700 MB TEMP JUST
ENOUGH TO ERODE A CONVECTIVE CAP ALLOWING SOME ELEVATED CONVECTION
TO OCCUR. THE LAST FEW RUNS OF THE HRRR HIGH-RESOLUTION MESOSCALE
MODEL SHOW A CONVECTIVE CHARACTER TO FORECAST PRECIPITATION ECHOES
ACROSS THE CENTRAL CAROLINAS IN THE 14-17Z TIME FRAME. PRECIPITATION
CHANCES WILL DROP TO LESS THAN 10 PERCENT BY MID-AFTERNOON AS THE
DISTURBANCES SWINGS BY TO THE NORTHEAST.
TONIGHT WARM AND MOIST SOUTH-SOUTHWESTERLY FLOW WILL CONTINUE OUT
AHEAD OF A STRONG COLD FRONT ADVANCING STEADILY EASTWARD. SHOWERS
AND THUNDERSTORMS ALONG THE FRONT WILL REACH THE PEE DEE REGION
LATE...PROBABLY AROUND 4 AM...AND MAY REACH THE COAST AROUND SUNRISE
SATURDAY MORNING. ALTHOUGH THIS IS THE SAME SYSTEM ANTICIPATED TO
BRING A LARGE SEVERE WEATHER OUTBREAK TO PORTIONS OF THE MID-SOUTH
AND TENNESSEE/OHIO VALLEYS TODAY...THE SYNOPTIC SITUATION IS NOT
QUITE AS FAVORABLE THIS FAR EAST SINCE THE PARENT UPPER DISTURBANCE
WILL BE SHEARING OUT TO THE NORTHEAST. THE LATE-NIGHT TIMING COUPLED
WITH COLD NEARSHORE OCEAN WATER TEMPERATURES ARE ALSO UNFAVORABLE
FACTORS FROM THE STANDPOINT OF MAINTAINING STRONG SURFACE-BASED
CONVECTION.
HIGHS TODAY SHOULD RANGE FROM THE MID 70S ACROSS MOST OF
SOUTHEASTERN NORTH CAROLINA...TO NEAR 80 ACROSS THE PEE DEE REGION
OF SOUTH CAROLINA. MUCH LIKE YESTERDAY WINDS BLOWING ONSHORE FROM
THE COLD NEARSHORE OCEAN WILL KEEP TEMPERATURES A GOOD 10-15 DEGREES
COLDER THAN INLAND AREAS. TONIGHT LOWS SHOULD ONLY FALL INTO THE
LOWER 60S WITH A STEADY SOUTH-SOUTHWEST WIND CONTINUING.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...LATEST FORECAST SOUNDINGS SUGGEST THIS
WEEKENDS RAIN EVENT COULD BRING SIGNIFICANT RAINFALL TO THE
REGION. YESTERDAY SOUNDINGS WERE SHOWING A BRIEF PERIOD THE
ATMOSPHERE WAS NEARLY SATURATED. HOWEVER THE LATEST GUIDANCE IS
MUCH WETTER. IT NOW LOOKS LIKE THE FRONT WILL DROP INTO THE AREA
SAT MORNING THEN STALL AS THE FRONT ENDS UP LAYING PARALLEL TO THE
FLOW ALOFT. EARLIER SOLUTIONS HAD THE FRONT STALLING OFF THE
COAST...A SOLUTION WHICH STILL COULD COME TO PASS. SPC HAS PUT
MOST OF THE FORECAST AREA INTO THE DAY 2 SLIGHT RISK...BUT THREAT
APPEARS LIMITED. FIRST THERE WILL BE CONSIDERABLE CLOUD COVER
ACROSS THE AREA SAT...LIMITING DIURNAL HEATING. MID LEVEL LAPSE
RATES ARE MARGINAL AT BEST MOSTLY UNDER 6C/KM. LOW LEVEL JETTING
IN FORECAST SOUNDINGS IS WEAKER THAN IN PREVIOUS RUNS. STRONG
SOUTHWEST FLOW WILL PUSH TEMPERATURES INTO THE LOW 70S DESPITE
CLOUDS AND PRECIP.
SURFACE WAVE DEVELOPS ALONG THE FRONT LATE SAT INTO SAT NIGHT SOUTH
OF THE AREA THEN TRACKS NORTHEAST ALONG THE FRONT BRINGING ANOTHER
ROUND OF SHOWERS AND ISOLATED THUNDERSTORMS TO THE REGION SAT NIGHT
INTO SUN. 5H TROUGH MOVES INTO THE AREA EARLY SUN...PUSHING THE
FRONT...ALONG WITH ANY ASSOCIATED PRECIP...OFF THE COAST. ARRIVAL
TIME OF COLD AIR SAT NIGHT WILL BE KEY TO DETERMINING HOW LOW TEMPS
DROP. SOME LIGHT PRECIP MAY LINGER INTO SUN MORNING BUT OVERALL SUN
SHOULD BE DRY WITH SKIES CLEARING DURING THE DAY. COLD ADVECTION
WILL KEEP TEMPS BELOW CLIMO SUN AND SUN NIGHT. HOWEVER BOUNDARY
LAYER REMAINS WELL MIXED SUN NIGHT...PREVENT TEMPS FROM DROPPING
BELOW FREEZING.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 AM FRIDAY...5H TROUGH WILL BE IN THE PROCESS OF LIFTING
NORTHEAST AT THE START OF THE PERIOD. DRY COLD FRONT MOVES ACROSS
THE REGION EARLY MON BUT ALL IT WILL BRING IS A REINFORCING SHOT
OF COOLER AIR LATER IN THE DAY. INCREASE IN CLOUD COVER MON
ASSOCIATED THIN LAYER OF MOISTURE BETWEEN 850 AND 750 MB IN
CONJUNCTION WITH A SHORTWAVE ROTATING AROUND THE BASE OF THE UPPER
TROUGH. PRECIP IS NOT AN ISSUE AS MOISTURE IS NOT NEARLY DEEP
ENOUGH. REMAINDER OF THE PERIOD WILL REMAIN DRY WITH VERY LITTLE
IN THE WAY OF CLOUDS. TEMPERATURES BOTTOM OUT MON NIGHT INTO
TUE...WITH LOWS MON NIGHT AT OR BELOW FREEZING AND HIGHS TUE IN
THE MID 50S. ELONGATED RIDGE AXIS SHIFTS OFFSHORE TUE NIGHT WITH
LIGHT ONSHORE FLOW DEVELOPING. ECMWF/GFS BOTH SHOW WEAK COASTAL
TROUGH DEVELOPING TUE NIGHT BUT BOTH MOVE THIS FEATURE ONSHORE
WED. AT THIS POINT TROUGH LOOKS TOO WEAK TO SUPPORT PRECIP. 5H
RIDGE BUILDS OVER THE SOUTHEAST WED THEN STRENGTHENS FOR THU.
TEMPERATURES RETURN CLOSE TO CLIMO WED/WED NIGHT...RUNNING NEAR TO
SLIGHTLY ABOVE CLIMO THU/THU NIGHT.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...A NEARLY STATIONARY FRONT ACROSS SOUTH-CENTRAL NORTH
CAROLINA WILL WAVE BACK NORTH AS A WARM FRONT LATER THIS MORNING.
MODELS SHOW WINDS WITHIN THE BOUNDARY LAYER DROPPING OFF QUITE
RAPIDLY AFTER 07Z. IFR CEILINGS/VIS ARE LIKELY TO DEVELOP. AS MID
AND HIGH CLOUDS OVERSPREAD THE REGION...THE THREAT OF FOG MAY
DIMINISH...ALTHOUGH HIGHER DEWPOINTS AND COOL OCEAN AND SOIL TEMPS
REMAIN POSITIVES FOR FOG FORMATION. THIS AFTERNOON WINDS WILL SHIFT
FROM SOUTHEASTERLY TO SOUTHWESTERLY...AND GUSTY THIS AFTERNOON.
MODELS HINTING AT STRATUS RETURNING TOWARD THE END OF THE FORECAST
PERIOD...BUT LOW CONFIDENCE.
EXTENDED OUTLOOK...THUNDERSTORMS/TEMPO IFR SATURDAY THROUGH SUNDAY
MORNING. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM FRIDAY...A FRONT STALLED OUT ACROSS INLAND SOUTHERN
NORTH CAROLINA WILL RETREAT FARTHER NORTH TODAY...OPENING UP THE
FLOODGATES FOR SUSTAINED SOUTHERLY WINDS TODAY INTO TONIGHT. MUCH
LIKE YESTERDAY...THE HUMID SUBTROPICAL AIRMASS WILL BECOME CHILLED
BY ITS JOURNEY ACROSS THE COLD NEARSHORE OCEAN WATERS AND COULD
YIELD LOW STRATUS CLOUDS OR PATCHY SEA FOG AT TIMES. SOUTH WINDS
WILL INCREASE TO AROUND 15 KT THIS AFTERNOON...AND THEN TO 20 KNOTS
TONIGHT. THESE SURFACE WIND SPEEDS SHOULD BE LIMITED BY A STABLE
BOUNDARY LAYER FROM THE COLD UNDERLYING OCEAN SURFACE. GO 30-40
MILES OFFSHORE WHERE WATER TEMPERATURES ARE WARMER...AND WIND SPEEDS
WILL EASILY BE ANOTHER 5-10 KNOTS HIGHER WITH MUCH ROUGHER SEAS TOO.
THE FRYING PAN SHOALS BUOY IS REPORTING 4-5 FT SEAS OVER THE PAST
COUPLE OF HOURS. SEAS WITHIN 20 MILES OF SHORE SHOULD AVERAGE 3 FT
TODAY...BUILDING TO 4-6 FT OVERNIGHT...HIGHEST IN THE FRYING PAN
SHOALS VICINITY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...INCREASING SOUTHWEST FLOW AHEAD OF A STRONG
COLD FRONT WILL REQUIRE A SCA HEADLINE AT SOME POINT SAT. SPEEDS
START OUT 15 TO 20 KT BUT INCREASE TO 20 TO 25 KT SAT
AFTERNOON/EVENING AS GRADIENT TIGHTENS UP. PROLONGED SOUTHWEST
FLOW WILL PROBABLY BUILD SEAS OVER 6 FT BEFORE SPEEDS REACH 25 KT.
DURATION OF SCA MAY END UP BEING RATHER BRIEF. THE FRONT WILL
STALL ALONG OR JUST OFF THE COAST WITH AN ILL-DEFINED PRESSURE
PATTERN KEEPING WINDS VARIABLE WITH SPEEDS BETWEEN 10 AND 15 KT.
WEAK WAVE OF LOW PRESSURE MOVES NORTHEAST ALONG THE STALLED
BOUNDARY PASSING EAST OF THE WATERS LATE SAT NIGHT. GRADIENT
TIGHTENS UP SUN AS THE LOW/FRONT MOVES EAST-NORTHEAST AND COLD
ADVECTION ARRIVES. STRONG OFFSHORE FLOW MAY WARRANT A BRIEF
DURATION HEADLINE SUN NIGHT INTO MON.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 330 AM FRIDAY...OFFSHORE FLOW WILL SLOWLY DECREASE ON MON AS
ELONGATED HIGH PRESSURE OVER THE MISSISSIPPI VALLEY SHIFTS EAST.
SPEEDS START OUT 15 TO 20 KT FROM THE WEST-NORTHWEST BUT DROP TO
10 TO 15 KT LATE MON NIGHT INTO TUE AS THEY BACK TO NORTH-
NORTHEAST. SEAS RUNNING 3 TO 5 FT DUE TO STRONG OFFSHORE FLOW WILL
SUBSIDE TO 2 TO 4 FT LATE MON INTO MON NIGHT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...43/TRA
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
501 PM CST FRI MAR 2 2012
.DISCUSSION...WINDS HAVE INCREASED ACROSS MUCH OF EASTERN NORTH
DAKOTA SUSTAINED AROUND 30 MPH. CALLS TO LAW ENFORCEMENT AND WEB
CAMS INDICATE THAT VISIBILITIES IN OPEN COUNTRY ARE 1/2SM OR LESS
AT TIMES ACROSS MUCH OF THE NORTHERN RED RIVER VALLEY DUE TO
MAINLY BLOWING SNOW. THUS...WILL EXPAND THE WINTER WX ADVISORY
INTO THIS AREA FOR BLOWING SNOW. VISIBILITES REMAIN DECENT ACROSS
THE SOUTHWEST FA...BUT WOULD NOT BE SURPRISED IF BLOWING SNOW
BEGINS TO CAUSE PROBLEMS AS THE TEMPERATURE DROPS (AS IT DID
ACROSS THE NORTH WHEN THE SNOW STARTED BLOWING AROUND). WILL
MONITOR THIS AREA...JUST NOT SURE IF WINDS WILL BE STRONG ENOUGH
BY THE TIME THE TEMPS ACTUALLY DROP.
THE WET ROADS FROM THE AFTERNOON ARE BECOMING ICY AS WELL.
UPDATED FORECAST TO EXPAND AREAS OF BLOWING SNOW INTO THE NEW
ADVISORY AREA...AND PATCHY BLOWING SNOW ACROSS THE SOUTHWEST FA.
INCREASED WIND SPEEDS A BIT. CONTINUED COLD AIR ADVECTION...925MB
WINDS 30-35 KNTOS...AND INCREASED SFC PRESSURE GRADIENT SHOULD
KEEP ELEVATED WINDS THROUGH MIDNIGHT (EVEN WITH LOSS OF SOLAR).
&&
.AVIATION...SLOW PROGRESSION OF SFC LOW AND PRESENCE OF WRAP
AROUND MOISTURE WILL KEEP CIGS/VSBY DOWN INTO MVFR/IFR TERRITORY
THRU THE TAF PERIOD. OTHERWISE...BEHIND THE SYSTEM...BREEZY NORTH
WINDS WILL RESULT IN BLSN WEST OF THE RED RIVER...AND PROGRESSING
EAST THROUGH THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 218 PM CST FRI MAR 2 2012/
SHORT TERM...
WINDS INCREASING OVER THE RED RIVER VALLEY THIS AFTERNOON INTO THE
EVENING AND WILL MAINTAIN WINTER WX ADVISORY OVER THE FAR NORTH AS
VSBYS REMAIN POOR. AREAS FROM LANGDON TO CAVALIER AND WALHALLA
RECEIVED AROUND 5 OR 6 INCHES OF FRESH SNOW FROM LAST EVENING INTO
THIS MORNING AND THESE WINDS WILL CONTINUE CAUSE REDUCED
VISIBILITY DUE TO BLOWING SNOW.
CANADIAN AND US RADAR COMPOSITE SHOWS THE MAIN SNOW BANDS NOW
WEAKENING OVER THE AREA WITH JUST LIGHT SNOW CONTINUING TO MOVE
SOUTH AND WRAP AROUND THE 500 MB LOW WHICH IS OVER GRAND FORKS AT
19Z. EXPECT TO SEE CONTINUED LIGHT SNOW INTO THE EVENING WITH A
GRADUAL SPREAD EAST IN TIME AND ENDING FROM THE WEST AS THE NIGHT
PROGRESSES. AN INCH OR SO IN NORTHWEST MN TONIGHT SEEMS REASONABLE
WITH LESS THAN THAT IN OTHER AREAS. FOR THE HEAVIER SNOWPACK AREAS
OF THE SOUTHERN VALLEY BLOWING SNOW SHOULD NOT BE A HUGE ISSUE AS
THE SNOW PACK IS QUITE HEAVY FROM PREV WET SNOW AND SNOWFALL THIS
AFTN-EVE NOT ENOUGH TO CAUSE ISSUES. BUT EVE SHIFT CAN MONITOR.
WINDS WILL BE GUSTY TO 35 MPH AT TIMES...WITH RUC AND OTHER SHORT
TERM MODELS SHOWING MIXING UP TO NR 925 MB WHERE WINDS WILL BE
30-35 KTS THRU 06Z. BORDERLINE WIND ADVISORY....BUT SUSTAINED
LIKELY JUST BLO THRESHOLDS.
WEAK RIDGE OF HIGH PRESSURE WILL BUILD EAST INTO ERN ND SATURDAY
WITH SOME CLEARING EXPECTED OVER ERN ND INTO THE VALLEY. DEPARTING
SYSTEM WILL GENERATE LEFTOVER LIGHT SNOW/FLURRIES IN FAR EASTERN
FCST AREA UNTIL NOON. HIGH PRESSURE WILL MOVE INTO MN SAT NIGHT.
DID REMOVE THE WIDESPREAD LOW POPS WE HAD IN THE FCST FOR ERN ND
INTO THE RED RIVER VALLEY SATURDAY AND REMOVED POPS FOR NW MN SAT
AFTN-NIGHT. WITH HIGH OVERHEAD AND POTENTIAL FOR CLEARING LOOKS
CHILLY AT NIGHT WITH OVERNIGHT LOWS SAT NIGHT IN THE SINGLE DIGITS
IN MANY AREAS.
NEXT THREAT FOR SOME LIGHT SNOW WILL BE OVERNIGHT SATURDAY NIGHT
AND INTO SUNDAY MAINLY OVER ERN ND INTO THE SRN VALLEY AS A WEAK
SHORT WAVE DROPS THRU CNTRL ND INTO ERN SD/SW MN. PRECIP WITH THIS
SYSTEM QUITE WEAK.
HIGH PRESSURE TO BUILD IN SUN NIGHT THEN WINDS WILL TURN SOUTH-
SOUTHWEST ON MONDAY AS A STORM SYSTEM GATHERS STRENGTH OVER
ALBERTA. THIS SHOULD BRING MILDER AIR INTO THE REGION.
LONG TERM (MON NIGHT-FRI)...
MODELS INITIALIZED WELL THIS RUN...BUT SOME DIFFERENCES SHOWING UP
IN PLACEMENT OF THE SFC FRONT FOR TUESDAY. OVERALL TRENDS STILL LOOK
GOOD FOR SHIFT TO A PROGRESSIVE PATTERN THROUGH THE END OF THE
PERIOD. THUS...CONTINUED TO LOOK AT A BLEND FOR THE GENERAL TIMING
OF THE FEATURES. THE 500HPA RIDGE IS EXPECTED TO SHIFT EAST WITH
THICKNESS VALUES INCREASING...SO EXPECTING TEMPS TO BE NEAR OR
SLIGHTLY ABOVE SEASONAL NORMS. BY THE END OF THE PERIOD...LOOK FOR
ANOTHER COLD FRONTAL PASSAGE...WITH ANOTHER CHANCE FOR MEASURABLE
PCPN.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
NDZ006>008-014>016-024-026>030-054.
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ001-
004-007.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
218 PM CST FRI MAR 2 2012
.SHORT TERM...
WINDS INCREASING OVER THE RED RIVER VALLEY THIS AFTERNOON INTO THE
EVENING AND WILL MAINTAIN WINTER WX ADVISORY OVER THE FAR NORTH AS
VSBYS REMAIN POOR. AREAS FROM LANGDON TO CAVALIER AND WALHALLA
RECEIVED AROUND 5 OR 6 INCHES OF FRESH SNOW FROM LAST EVENING INTO
THIS MORNING AND THESE WINDS WILL CONTINUE CAUSE REDUCED
VISIBILITY DUE TO BLOWING SNOW.
CANADIAN AND US RADAR COMPOSITE SHOWS THE MAIN SNOW BANDS NOW
WEAKENING OVER THE AREA WITH JUST LIGHT SNOW CONTINUING TO MOVE
SOUTH AND WRAP AROUND THE 500 MB LOW WHICH IS OVER GRAND FORKS AT
19Z. EXPECT TO SEE CONTINUED LIGHT SNOW INTO THE EVENING WITH A
GRADUAL SPREAD EAST IN TIME AND ENDING FROM THE WEST AS THE NIGHT
PROGRESSES. AN INCH OR SO IN NORTHWEST MN TONIGHT SEEMS REASONABLE
WITH LESS THAN THAT IN OTHER AREAS. FOR THE HEAVIER SNOWPACK AREAS
OF THE SOUTHERN VALLEY BLOWING SNOW SHOULD NOT BE A HUGE ISSUE AS
THE SNOW PACK IS QUITE HEAVY FROM PREV WET SNOW AND SNOWFALL THIS
AFTN-EVE NOT ENOUGH TO CAUSE ISSUES. BUT EVE SHIFT CAN MONITOR.
WINDS WILL BE GUSTY TO 35 MPH AT TIMES...WITH RUC AND OTHER SHORT
TERM MODELS SHOWING MIXING UP TO NR 925 MB WHERE WINDS WILL BE
30-35 KTS THRU 06Z. BORDERLINE WIND ADVISORY....BUT SUSTAINED
LIKELY JUST BLO THRESHOLDS.
WEAK RIDGE OF HIGH PRESSURE WILL BUILD EAST INTO ERN ND SATURDAY
WITH SOME CLEARING EXPECTED OVER ERN ND INTO THE VALLEY. DEPARTING
SYSTEM WILL GENERATE LEFTOVER LIGHT SNOW/FLURRIES IN FAR EASTERN
FCST AREA UNTIL NOON. HIGH PRESSURE WILL MOVE INTO MN SAT NIGHT.
DID REMOVE THE WIDESPREAD LOW POPS WE HAD IN THE FCST FOR ERN ND
INTO THE RED RIVER VALLEY SATURDAY AND REMOVED POPS FOR NW MN SAT
AFTN-NIGHT. WITH HIGH OVERHEAD AND POTENTIAL FOR CLEARING LOOKS
CHILLY AT NIGHT WITH OVERNIGHT LOWS SAT NIGHT IN THE SINGLE DIGITS
IN MANY AREAS.
NEXT THREAT FOR SOME LIGHT SNOW WILL BE OVERNIGHT SATURDAY NIGHT
AND INTO SUNDAY MAINLY OVER ERN ND INTO THE SRN VALLEY AS A WEAK
SHORT WAVE DROPS THRU CNTRL ND INTO ERN SD/SW MN. PRECIP WITH THIS
SYSTEM QUITE WEAK.
HIGH PRESSURE TO BUILD IN SUN NIGHT THEN WINDS WILL TURN SOUTH-
SOUTHWEST ON MONDAY AS A STORM SYSTEM GATHERS STRENGTH OVER
ALBERTA. THIS SHOULD BRING MILDER AIR INTO THE REGION.
.LONG TERM (MON NIGHT-FRI)...
MODELS INITIALIZED WELL THIS RUN...BUT SOME DIFFERENCES SHOWING UP
IN PLACEMENT OF THE SFC FRONT FOR TUESDAY. OVERALL TRENDS STILL LOOK
GOOD FOR SHIFT TO A PROGRESSIVE PATTERN THROUGH THE END OF THE
PERIOD. THUS...CONTINUED TO LOOK AT A BLEND FOR THE GENERAL TIMING
OF THE FEATURES. THE 500HPA RIDGE IS EXPECTED TO SHIFT EAST WITH
THICKNESS VALUES INCREASING...SO EXPECTING TEMPS TO BE NEAR OR
SLIGHTLY ABOVE SEASONAL NORMS. BY THE END OF THE PERIOD...LOOK FOR
ANOTHER COLD FRONTAL PASSAGE...WITH ANOTHER CHANCE FOR MEASURABLE
PCPN.
&&
.AVIATION...
SLOW PROGRESSION OF SFC LOW AND PRESENCE OF WRAP AROUND MOISTURE
WILL KEEP CIGS/VSBY DOWN INTO MVFR/IFR TERRITORY THRU THE TAF
PERIOD. OTHERWISE...BEHIND THE SYSTEM...BREEZY NORTH WINDS WILL
RESULT IN BLSN WEST OF THE RED RIVER...AND PROGRESSING EAST THROUGH
THE PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
NDZ006>008-014-015.
MN...NONE.
&&
$$
RIDDLE/HOPKINS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
240 PM EST FRI MAR 2 2012
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WITH COLD FRONT LATE FRIDAY...SOME STORMS
COULD BE STRONG TO SEVERE. COOLER WEATHER ESTABLISHES FOR THE
WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH AN APPROACHING WARM FRONT
AND MOISTURE PUNCH HAVE BEEN ONGOING ACROSS THE FORECAST AREA SINCE
MID MORNING. WRFNMM...HRRR...AND CURRENT RADAR HAVE SOME SMALL
TIMING DIFFERENCES...HOWEVER ALL AGREE THAT THERE WILL BE A BREAK IN
THE SHOWERS AND STORMS FOLLOWING THE WARM FRONT...PRIOR TO THE COLD
FRONT ARRIVING LATER THIS EVENING. RECENT RUC BUFKIT SOUNDINGS SHOW
JUST OVER 500J/KG CAPE IN EASTERN KY/WESTERN WV AHEAD OF THE COLD
FRONT LATER THIS EVENING...SO STILL THINKING STRONG TO SEVERE
THUNDERSTORMS POSSIBLE AHEAD OF THE FRONT. WITH THE TIME OF DAY THE
STORMS ARE EXPECTED...WE MAY SEE DECREASING THERMODYNAMICS AS THE
STORMS MOVE INTO CENTRAL WV. HOWEVER WITH PLENTY OF SHEAR AND
DYNAMIC LIFT FROM THE FRONT...STORMS SHOULD STILL BE ABLE TO SUPPORT
DAMAGING WINDS AND HAIL...AND POSSIBLY AN ISOLATED TORNADO.
COLD FRONT PASSAGE EXPECTED FROM FROM NW TO SE AROUND 03-06Z
TONIGHT. PRECIP CHANCES DECREASE QUICKLY AFTER THE FRONT MOVES
THROUGH.
NOT A REAL STRONG COLD PUNCH IMMEDIATELY AFTER THE FRONT...AND WITH
SOME GUSTY WINDS HANGING AROUND...WILL REMAINED WELL MIXED SO TEMPS
SHOULD REMAIN FAIRLY STEADY MOST OF THE NIGHT WITH A GRADUALLY
DECREASE THROUGH THE EARLY MORNING HOURS. TRENDED TOWARDS THE MET
AND THEN MADE SOME MINOR TWEAKS TO HOLD THE TEMPS STEADIER AT FIRST.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
CAA REGIME SETTING UP FOR THE WEEKEND. SAT SHOULD SEE SUN EARLY
BEFORE STRONGER CAA LATE IN THE DAY ALLOWS FOR STRATOCU AND CU TO
DEVELOP AS UPR TROF PIVOTS IN. DESPITE H85 TEMPS -2 TO -6....THINK
ENOUGH MIXING WILL OCCUR FOR THE WARMER NUMBERS OFF GUIDANCE TO
BECOME REALIZED. FLOW COMES MORE CONDUCIVE FOR UPSLOPE SUN INTO SUN
NIGHT AS UPR TROF AXIS SWINGS THRU. INHERITED SNOW/POP GRIDS
GENERALLY LOOKED GOOD AND ONLY NEEDED SOME FINESSING. ALLOWED FOR A
HIGH THRESHOLD FOR RAIN/SNOW DURING DAY SUN BASED ON TEMPS ALOFT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
PRIMARY FORECAST CONCERN WILL BE A CHANCE OF PRECIPITATION SUNDAY
NIGHT INTO MONDAY AS A SHORTWAVE TROUGH MOVES BY THE REGION.
SUNDAY NIGHT...INITIALLY LARGE SCALE FORCING FOR ASCENT PUSHES
EASTWARD OUT OF THE AREA BUT WILL QUICKLY REDEVELOP DURING THE
OVERNIGHT HOURS AS A SHORTWAVE MOVES NW-SE THROUGH THE MEAN FLOW
AROUND THE UPPER LEVEL TROUGH BASE. THIS FORCING IS MAXIMIZED OVER
THE SOUTHERN CWA AROUND 12Z MON BEFORE LARGE SCALE SUBSIDENCE
QUICKLY DEVELOPS ACROSS AREA BY 18Z MON IN ITS WAKE...WITH TROUGH
AXIS EAST OF AREA BY THEN. IN ADDITION...GOOD PVA AND LOW LEVEL WARM
ADVECTION AT BOTH 700MB AND 850MB SHOULD BE ENOUGH TO GENERATE SOME
PRECIP OVER THE AREA...WITH HIGHEST POPS ACROSS SOUTHERN AND WESTERN
CWA BTWN 06Z-12Z MON. TEMPS WILL DROP INTO THE LOWER 30S MOST
LOCATIONS BY 06Z AND WITH MODEL CONSENSUS QPF AROUND THE 0.1 TO 0.2
INCH RANGE...AN INCH OR TWO OF SNOW WILL BE POSSIBLE.
PRECIP WILL BY AND LARGE COME TO END BY MIDDAY MONDAY BUT WILL
CONTINUE SLIGHT CHANCE/LOW CHANCE POPS MAINLY ACROSS SOUTHERN ZONES
AND MOUNTAINS UNTIL 00Z TUE TO ACCOUNT FOR PLENTIFUL LOW LEVEL
MOISTURE IN PLACE WITH A 700MB BAROCLINIC ZONE PROGGED NEAR THE
WESTERN/SOUTHERN CWA MON AFTERNOON. SNOW WILL CHANGE TO RAIN HOWEVER
ACROSS LOWLANDS AS TEMPS WARM THROUGH THE 30S INTO THE 40S. ALL
PRECIP SHOULD END BY TUE 00Z WITH CLEARING SKIES. TUE MORNING WILL
BE COLDEST MORNING DURING THE PERIOD. WITH 925MB TEMPS AROUND -3C TO
-4C 12Z TUE AND MOSTLY CLEAR SKIES/LIGHT WINDS...HAVE CONTINUED TO
LOWER MINS A FEW DEGREES DOWN INTO THE LOW 20S ACROSS THE LOWLANDS.
HIGHS TUE WILL WARM TO NEAR SEASONAL LEVELS AND INTO THE 60S WED/THU
AS UPPER LEVEL RIDGING BUILDS INTO THE REGION.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
SHOWERS AND THUNDERSTORMS ONGOING ACROSS FORECAST AREA. THESE ARE
STILL AHEAD OF THE WARM FRONT...SO EXPECT AT LEAST SCATTERED
ACTIVITY TO CONTINUE AS THE WARM FRONT MOVES THROUGH AND THE WARM
SECTOR TAKES OVER. TRIED TO TIME OUT A BRIEF BREAK...OR AT LEAST A
REDUCTION IN PRECIP COVERAGE BETWEEN THE WARM FRONT ACTIVITY THIS
AFTERNOON AND THEN THE COLD FRONT BASED PRECIP FOR LATER THIS
EVENING. WITH THAT SAID...STILL KEPT MAINLY MVFR CONDITIONS
THROUGHOUT WITH SCATTERED SHOWERS AND THUNDERSTORMS. WILL HANDLE
LOWER CIGS AND VSBYS IN HEAVIER SHOWERS WITH TEMPOS AS NEEDED.
AFOREMENTIONED COLD FRONT WILL COME THROUGH LATE THIS EVENING...INTO
THE OVERNIGHT...BRINGING INCREASED THUNDERSTORM ACTIVITY...WITH
STRONG TO SEVERE STORMS POSSIBLE AHEAD OF THE FRONT. STRONG GUSTY
WINDS AND HAIL SHOULD BE THE MAIN THREAT. SHOWERS AND THUNDERSTORMS
SHOULD DIMINISH PRETTY RAPIDLY AFTER THE COLD FRONT MOVES THROUGH.
AS THE WARM FRONT PASSES TODAY...SYNOPTIC FLOW WILL BECOME GUSTY OUT
OF THE SOUTH. THEN AS THE COLD FRONT PASSES ACROSS THE AREA...FROM
03Z TO 07Z...WINDS WILL BEGIN TO TURN TO THE WEST BUT REMAIN ON THE
GUSTY SIDE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: UNCERTAINTY REMAINS ON EXACT TIMING AND
LOCATIONS OF STRONGEST CONVECTION AND RELATED MVFR AND IFR
CONDITIONS. TEMPOS MAY BE NEEDED FOR BRIEF IFR...GUSTY THUNDERSTORM
WINDS...AND HEAVY RAIN/THUNDERSTORMS.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EST 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
CRW CONSISTENCY M M H H M M M M M M M M
HTS CONSISTENCY M M M M M M M L M M H H
BKW CONSISTENCY L L L L L M M M M M M M
EKN CONSISTENCY M M H H M L M M M M M M
PKB CONSISTENCY L L L L H L M M M M H M
CKB CONSISTENCY H M M M M H H M M M M M
AFTER 18Z SATURDAY...
MVFR TO IFR POSSIBLE IN MOUNTAIN SNOW SHOWERS SATURDAY AFTERNOON THROUGH
SUNDAY.
&&
.HYDROLOGY...
GIVEN LOW FFG VALUES AND SEVERAL ROUNDS OF SHOWERS AND HEAVY
THUNDERSTORMS...SOME AREA WILL EASILY RECEIVE EXCESSIVE RUNOFF
RESULTING IN FLOODING. THE MOST VULNERABLE AREA INCLUDE N CNTRL WV
AND A SMALL AREA IN NORTHERN ATHENS AND SOUTHERN WASHINGTON
COUNTY...WHERE AS LITTLE AS THREE QUARTERS OF AN INCH WITHIN AN HOUR
COULD START CAUSING PROBLEMS.
FFA ISSUED FOR ALL BUT EXTREME WESTERN COUNTIES BEGINNING 2 PM THIS
AFTERNOON AND RUNNING THROUGH THE OVERNIGHT. THE WESTERN COUNTIES
ARE DRIER AND WILL NOT RECEIVE QUITE AS MUCH RAINFALL. OTHERWISE PW
VALUES OF 1-1.2 INCHES AND 60 KTS OF LOW LEVEL FEED WILL EASILY
SUPPORT RAINFALL AMOUNTS OVER AN INCH...WITH AREA THAT GET HIT HARD
MORE THAN ONCE PUSHING TWO INCHES.
NO MAJOR MAINSTEM RIVER PROBLEMS ARE EXPECTED AT THIS TIME ALTHOUGH
MOST GAGES SHOULD GET AT LEAST AS HIGH AS THEY DID FROM THE LAST
EVENT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR WVZ005>011-013>020-
024>040-046-047.
OH...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR OHZ067-075-076-
085>087.
KY...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR KYZ101>103-105.
VA...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR VAZ003-004.
&&
$$
SYNOPSIS...MZ/GG/30
NEAR TERM...MZ
SHORT TERM...30
LONG TERM...GG
AVIATION...MZ
HYDROLOGY...TRM
AREA FORECAST DISCUSSION
NWS PORTLAND OR
908 PM PST THU MAR 1 2012
.SYNOPSIS...SHOWERS DECREASING...AND SNOW LEVELS ARE SLOWLY RISING.
WARM FRONT WILL BUCKLE ACROSS REGION FRI WITH SPOTTY RAIN MAINLY
NORTH. HIGH PRES BUILDS OVER S OREGON THIS WEEKEND...WITH CLOUDS
DECREASING AND PRECIP RETREATING TO N BACK INTO WASHINGTON. DRY
WEATHER WILL END EARLY NEXT WEEK AS RAIN RETURNS ON MON.
&&
.SHORT TERM...STILL A FEW SHOWERS AROUND...SOME THAT HAD A BIT OF
SMALL HAIL/GRAUPEL IN THEM EARLIER THIS EVENING...THAT FORMED ALONG A
CONVERGENCE BOUNDARY ALONG THE OREGON/WASHINGTON BORDER. RUC SUGGESTS
SHOWERS SHOULD EASE QUICKLY AFTER 6Z...THOUGH ONSHORE FLOW CONTINUES
AND EXPECT WE`LL SEE SOME PESKY SHOWERS CONTINUE AFTER MIDNIGHT
GENERALLY FROM PORTLAND/VANCOUVER EAST...THOUGH COVERAGE DECREASES.
WE MAY ALSO SEE ISOLATED RAIN SNEAKING BACK INTO THE COAST AHEAD OF
THE OFFSHORE WARM FRONT OVERNIGHT. WITH BREAKS IN CLOUD COVER AND A
VERY MOIST AIR MASS WITH THE AIR MASS STABILIZING...PATCHY FOG IS
POSSIBLE...THOUGH STRATUS LOOKS MORE LIKELY. BETTER THREAT OF FOG
LIES ACROSS S HALF OF WILLAMETTE VALLEY. TEMPS NEAR FREEZING WILL
HAVE TO WATCH FOR AREAS OF BLACK ICE FRI AM. GUIDANCE KEEPS MOST
AREAS IN THE VALLEY ABOVE FREEZING AND HAVE NUDGED TEMPS UP A
BIT...THOUGH AREAS WITH MORE CLEARING WILL BE PRONE TO THE COOLER
TEMPS
EARLY MODELS SUGGESTED WARM FRONT HUNG UP OVER PAC NW THIS
WEEKEND...BUT NOW APPEARS THIS NOT THE CASE. WARM FRONT BUCKLES
ACROSS REGION ON FRI NIGHT AND SAT...WITH LIGHT RAIN OVER REGION
ESPECIALLY N OF A NEWPORT TO SANTIAM PASS LINE. AS HIGH PRES BUILDS
OVER S OREGON AND N CALIF THIS WEEKEND...SHOULD SEE RAIN THREAT
DECREASING RAPIDLY ON SAT...THEN DRY WEATHER WITH MIX OF SUN AND
CLOUDS FOR SAT AFTERNOON THROUGH SUN. HAVE ADJUSTED FORECASTS TO SHOW
DRIER AND MILDER WEATHER FOR THIS WEEKEND. KMD/ROCKEY.
.LONG TERM...THE NEXT SYSTEM APPROACHES LATE SUNDAY NIGHT AND SHOULD
BRING ANOTHER ROUND OF RAIN AND MOUNTAIN SNOW DURING THE DAY MONDAY.
SHOWERS SHOULD CONTINUE ACROSS THE AREA IN THE WAKE OF THIS SYSTEM
INTO TUESDAY. AN UPPER LEVEL TROUGH OVER THE NE PACIFIC WILL BRING
PERIODS OF SHOWERS THROUGH THE WEEK...BUT MODEL CONSENSUS IS POOR ON
THE EVOLUTION OF THIS PATTERN. HAVE KEPT THE FORECAST LEANING
TOWARDS CLIMATOLOGY TUESDAY AND BEYOND. BROWN
&&
.AVIATION...SHOWERS ON THE DECREASE THIS EVENING WITH MAINLY VFR
CONDITIONS. MAY SEE SOME LOW MVFR TO IFR CONDITIONS IN FOG
ESPECIALLY SOUTH OF KSLE LATER TONIGHT AS THE MOIST AIR MASS
STABILIZED A BIT. NORTH OF KSLE MAY BE MORE MVFR CIGS WHERE
ONSHORE FLOW CONTINUES.
KPDX AND APPROACHES...MOSTLY VFR CONDITIONS WITH OCCASIONAL MVFR
THIS EVENING...THEN INCREASING CHANCES FOR MVFR CIGS AROUND 1500
FEET AFTER 11Z. PATCHY FOG 2-3SM ALSO POSSIBLE IN THE VICINITY OF
KPDX.
&&
.MARINE...NW SWELL TRAIN CONTINUES TO SUBSIDE. SEAS RUNNING
AROUND 10 TO 12 FT...ABOUT A FOOT OR 2 BELOW GUIDANCE. SO
HAZARDOUS SEAS ADVISORY MAY END SEVERAL HOURS EARLIER THAN CURRENT
FORECAST.
A WEAK FRONT MOVING THROUGH ON FRIDAY WILL BRIEFLY GIVE US
ADVISORY LEVEL WINDS. HIGH PRES WILL BRING FAIRLY CALM CONDITIONS
BACK OVER THE WATERS SATURDAY...BEFORE ANOTHER WEAK FRONT MOVES
THROUGH SUNDAY NIGHT.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST
FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR WINDS FROM 7 AM PST
TO 4 PM PST FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
1 AM PST FRIDAY.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM
10 AM TO 2 PM PST FRIDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
551 PM CST SAT MAR 3 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY
245 PM CST SAT MAR 3 2012
THE MAIN FOCUS IN THE SHORT TERM IS ON THE SNOW CHANCES TONIGHT
INTO TOMORROW FOLLOWED BY HOW WARM IT WILL GET GOING INTO TUESDAY.
CYCLONIC FLOW AT THE SURFACE AND ALOFT IS IN PLACE THROUGH MUCH OF
THE UPPER MISSISSIPPI RIVER VALLEY AND GREAT LAKES WITH AN
AMPLIFYING MID TO UPPER LEVEL RIDGE FORMING ALONG THE ROCKIES AND
PACIFIC NORTHWEST. BACK AT THE SURFACE...AN INVERTED TROUGH
EXTENDS WEST OUT OF A SURFACE LOW THROUGH THE GREAT LAKES TOWARD
NORTHERN MINNESOTA. THIS FEATURE...IN COMBINATION WITH STEEP LOW
LEVEL LAPSE RATES AND WEAK FRONTOGENESIS...HAS BEEN THE FOCUS FOR
SNOW SHOWER DEVELOPMENT THROUGH THE REGION. AS THE SURFACE LOW
CONTINUES TO TRACK TO THE EAST TONIGHT/TOMORROW...THIS TROUGH WILL
SLOWLY SINK TO THE SOUTH AND KEEP THE FOCUS OF SNOW SHOWER
ACTIVITY ACROSS CENTRAL WISCONSIN. ANY ACCUMULATIONS WILL BE MINOR
AT JUST A FEW TENTHS OF AN INCH. OTHERWISE...SKIES WILL LIKELY
REMAIN CLOUDY OVERNIGHT THOUGH SOME BRIEF BREAKS POSSIBLE ACROSS
MINNESOTA AND IOWA AS A WEAK SURFACE RIDGE MOVES IN. HAVE KEPT
CLOUD TRENDS ON THE PESSIMISTIC SIDE THOUGH AT 03.12Z NAM/GFS LOW
LEVEL RH VALUES REMAIN AT 50 PERCENT OR HIGHER INTO TOMORROW.
THE BETTER CHANCE FOR ACCUMULATING SNOW WILL BE WITH A SHORT WAVE
TROUGH CURRENTLY ROUNDING THE NORTHERN PERIPHERY OF THE RIDGE IN
SOUTHWEST CANADA THAT WILL QUICKLY DROP DOWN THROUGH MINNESOTA
AND IOWA TOMORROW. THE FORCING WITH THIS SYSTEM WILL BE FAIRLY
DECENT WITH A STRONG SFC TO 500MB FRONTOGENETIC CIRCULATION AND
DEEP QG FORCING. THIS WILL LIKELY LEAD TO A NARROW BAND OF SNOW
FORMING FROM SOUTHERN MINNESOTA INTO CENTRAL AND EASTERN IOWA. THE
MAIN QUESTION IS WHERE THIS BAND WILL END UP AND HOW FAR INTO THE
FORECAST AREA WILL IT GET. THE 03.12Z GFS IS THE BROADEST WITH ITS
FORCING AS IT HAS A MUCH LARGER AREA OF QG FORCING AND ALSO HAS
THE FRONTOGENESIS FURTHER EAST INTO SOUTHEAST MINNESOTA AND
NORTHEAST IOWA. MEANWHILE...THE 03.12Z NAM IS MUCH NARROWER WITH
ITS SNOW BAND DUE TO A NARROWER LOW LEVEL FRONTOGENETIC BAND AND
NOT AS MUCH QG FORCING. THE 03.12Z GEM SHOWS A SIMILAR SOLUTION TO
THE NAM WHICH KEEPS THIS SNOW BAND JUST TO THE WEST OF THE
FORECAST AREA. THE 03.15Z SREF HAS TRENDED THIS WAY AS WELL FROM
WHAT IT SHOWED ON THE 03.09Z RUN AS WELL. THEREFORE...HAVE
SHIFTED THE HIGHEST CHANCES FOR SNOW AND HIGHER TOTALS FURTHER
SOUTH AND WEST TO JUST OUTSIDE OF NORTHEAST IOWA. SNOWFALL
AMOUNTS OF 1-2 INCHES CAN BE EXPECTED UNDER THIS BAND...WITH
LESSER AMOUNTS OF AN INCH OR LESS AS YOU QUICKLY GET NORTH AND
EAST OF IT. AS THIS TROUGH MOVES THROUGH...THE LEFT OVER INVERTED
SURFACE TROUGH OVER NORTHERN WISCONSIN WILL LIKELY LIGHT UP WITH
MORE SNOW SHOWERS AS WELL...MAINLY IN THE AFTERNOON.
AFTER THIS SYSTEM QUICKLY MOVES THROUGH BY TOMORROW NIGHT...THE
FOCUS WILL GO TO HOW WARM WE WILL BE ABLE TO GET GOING INTO
TUESDAY. THE UPPER LEVEL RIDGE WILL MOVE EAST AS LOW LEVEL WARM
AIR ADVECTION KICKS IN MONDAY NIGHT AND PERSIST INTO TUESDAY. THE
SURFACE TO LOW LEVEL PRESSURE GRADIENT WILL TIGHTEN UP AND CAUSE
THE WINDS TO BE RATHER STRONG OUT OF THE SOUTH-SOUTHWEST. 850MB
TEMPERATURES WILL CLIMB TO ABOUT +10C BY TUESDAY AFTERNOON WHICH
IS ONLY ABOUT 1.5 STANDARD DEVIATIONS ABOVE THE NORM. THE KEY FOR
HOW WARM WE GET WILL BE WITH HOW MUCH OF THE WARM AIR WE WILL BE
ABLE TO MIX DOWN. THE MAIN SURFACE WARM FRONT LOOKS LIKE IT WILL
NOT REACH THE REGION AND INSTEAD RUN FROM A SURFACE LOW IN
NEBRASKA EAST THROUGH SOUTHERN IOWA. SO...FOR NOW IT LOOKS LIKE A
NICE YET WINDY WARM UP...BUT NOT WARM ENOUGH TO BE CONSIDERED
RECORD BREAKING.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
245 PM CST SAT MAR 3 2012
THE FOCUS OF THE EXTENDED PERIOD IS WITH THE COLD FRONT THAT IS
FORECAST TO COME THROUGH ON WEDNESDAY FOLLOWED BY HOW MUCH COLD
AIR DROPS DOWN ACROSS THE REGION GOING INTO NEXT WEEKEND.
THE 03.12Z GFS/ECMWF/GEM ALL SEEM TO BE IN DECENT AGREEMENT WITH
BRINGING A COLD FRONT THROUGH THE FORECAST AREA ON WEDNESDAY WITH
PRECIPITATION FORMING IN RESPONSE TO LOW LEVEL MOISTURE ADVECTION
RAMPING UP THROUGH THE DAY. PRECIPITATION WILL FORM AHEAD...ALONG
AND BEHIND THIS SLOW MOVING FRONT AND TRANSITION FROM ALL RAIN ON
WEDNESDAY TO ALL SNOW BY THURSDAY MORNING. GIVEN THE SLOW
PROGRESSION OF THE FRONT AND THE LACK OF ANY MUCAPE DEVELOPING
AHEAD OF IT...NOT THINKING THAT THUNDER IS GOING TO OCCUR BUT THAT
COULD CHANGE IF THE SYSTEM SLOWS AT ALL AND ALLOWS FOR MORE OF A
WARM UP ON WEDNESDAY.
AFTER THIS SYSTEM MOVES THROUGH THERE IS MUCH UNCERTAINTY WITH HOW
MUCH COLD AIR GETS PULLED DOWN FROM CANADA. THE 03.12Z GFS TAKES
A SURFACE RIDGE ACROSS THE GREAT LAKES WITH A CUT OFF LOW STUCK
ALONG THE GULF COAST. MEANWHILE...THE 03.12Z ECMWF DOES NOT HAVE
THIS LOW AND BRINGS THE RIDGE AND COLD AIR ALL THE WAY DOWN TO THE
GULF COAST. 850MB TEMPERATURES BETWEEN THESE TWO MODELS SHOW A 10
TO 15C DIFFERENCE IN TEMPERATURES BETWEEN THE WARMER GFS AND
COOLER ECMWF. THUS...CONFIDENCE IS NOT TOO HIGH IN TEMPERATURES OR
THE PATTERN GOING INTO THE LATER PORTIONS OF THE WEEK AND NEXT
WEEKEND.
&&
.AVIATION...TONIGHT AND SUNDAY
551 PM CST SAT MAR 3 2012
BIGGEST CHALLENGES FOR THE TAF PERIOD ARE CLOUDS AND CLEARING
TRENDS THIS EVENING...PARTICULARLY AT KRST. CURRENTLY...AREA OF
CLEAR SKIES EXTENDS ACROSS CENTRAL MINNESOTA SOUTHWARD TO NEAR
KOWA AS LOSS OF DAYTIME HEATING ALLOWED STRATOCU TO ERODE. AT
KRST...OPTED TO HANG ONTO A PESSIMISTIC FORECAST AS NEAR AND SHORT
TERM GUIDANCE / HRRR AND RUC SOUNDINGS / SUGGEST WINDS WILL VEER
SLIGHTLY TO THE NORTHWEST THIS EVENING...AND THIS MAY SAG LOW
CLOUDS CURRENTLY ALONG THE MINNESOTA/WISCONSIN BORDER OVER
KRST...THUS LIMITING CHANCES FOR GOING CLEAR. FOR THE REMAINDER OF
THE PERIOD AT KRST...MVFR CEILINGS WILL PREVAIL AS A LOW PRESSURE
SYSTEM DIVES SOUTHEAST THROUGH SOUTHWEST MINNESOTA TOMORROW. PRECIP
SHOULD REMAIN SOUTH AND WEST OF KRST.
AT KLSE...SCATTERED SNOW SHOWERS WILL DIMINISH EARLY THIS
EVENING...AND ANY LOWERED VISIBILITIES WILL IMPROVE. MFVR CEILINGS
WILL PERSIST THROUGH THE ENTIRE PERIOD. ALTHOUGH SOME MODEL
GUIDANCE / NAM AND GFS / TRY TO SHOW CLEARING SUNDAY
AFTERNOON...FEEL THIS IS TOO FAST GIVEN CYCLONIC FLOW PREVAILING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
245 PM CST SAT MAR 3 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...ZT/AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1138 AM CST FRI MAR 2 2012
.SHORT TERM...TODAY AND TONIGHT
1032 AM CST FRI MAR 2 2012
THE MAIN CONCERN COMING IN THIS MORNING WAS WITH WHETHER THE MAIN
BAND COULD SET UP ACROSS THE SOUTHERN PORTION OF GRANT COUNTY
WHERE WE WOULD END UP WITH ADVISORY WORTHY SNOW THERE. THE LATEST
RADAR RETURNS ALONG WITH REGIONAL OBSERVATIONS SHOW THAT THIS BAND
OF HEAVY SNOW HAS SET UP NEAR PLATTEVILLE DOWN TOWARD CEDAR RAPIDS
AND LIKELY WILL NOT SHIFT MUCH TO THE WEST THROUGH THE REST OF
TODAY AS THE DEEPENING NEGATIVELY TILTED MID LEVEL LOW LIFTS UP
INTO THE WESTERN GREAT LAKES REGION. THE 02.13Z HRRR AND PREVIOUS
RUNS HAVE BEEN FAIRLY CONSISTENT THIS MORNING WITH BRINGING THIS
SNOW BAND ACROSS SOUTHWEST WISCONSIN THIS AFTERNOON BEFORE
WEAKENING THE BAND AND TAKING IT EAST TONIGHT. WITH ABOUT A 6 HOUR
WINDOW FOR HEAVY SNOW...THINKING IS THAT THE POTENTIAL IS THERE
FOR AT LEAST 3 INCHES TO AS MUCH AS 6 INCHES WITH AN INCH PER HOUR
FALLING AT TIMES UNDER THE BAND. THEREFORE...HAVE ISSUED A WINTER
WEATHER ADVISORY FOR GRANT COUNTY WHERE THE THREAT IS THE
GREATEST. CONSIDERED ADDING RICHLAND AND ADAMS COUNTY AS
WELL...BUT THINK THAT THE BAND SHOULD STAY JUST TO THEIR EAST OR
AT WORST CATCH A SLIVER OF THE COUNTY. WILL CONTINUE TO MONITOR
CONDITIONS THROUGH THIS AFTERNOON PARTICULARLY ACROSS THESE
COUNTIES. WENT WITH AN END TIME OF 9PM TO MATCH UP WITH
NEIGHBORING END TIMES...BUT THINK THAT WE MAY BE ABLE TO END IT A
LITTLE EARLIER THAN THAT THIS EVENING.
OTHERWISE...ALSO HAD TO ADJUST THE SNOW DEVELOPING ACROSS A
SECONDARY BAND TO THE WEST OF THIS ONE FROM STEVENS POINT
SOUTHWEST TO LA CROSSE AND OELWEIN. SNOWFALL AMOUNTS ARE STILL
EXPECTED TO REMAIN AT LESS THAN AN INCH ACROSS THIS BAND.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
310 AM CST FRI MAR 2 2012
UPPER LEVEL RIDGING WILL BE OVER THE UPPER MIDWEST UNTIL LATE IN
THE PERIOD. BOTH THE ECMWF AND 02.00Z GFS SHOW A LONG WAVE TROUGH
CROSSING THE CENTRAL PART OF THE COUNTRY BUT SHOW CONSIDERABLE
DIFFERENCES ON ITS STRENGTH. A COLD FRONT SHOULD CROSS THE REGION
WEDNESDAY AND WEDNESDAY NIGHT WITH A CHANCE OF SOME PRECIPITATION
BEFORE PUSHING EAST OF THE AREA THURSDAY. TEMPERATURES AHEAD OF
THIS FRONT ARE EXPECTED TO WARM TO ABOUT 10C AT 850 MB. THE GFS
BUFKIT SOUNDING SUGGESTS THE POTENTIAL TO MIX UP TO ABOUT THIS
LEVEL WHICH COULD PUSH SURFACE TEMPERATURES WELL INTO THE 50S FOR
MUCH OF THE AREA.
&&
.AVIATION...THROUGH 18Z SATURDAY
1138 AM CST FRI MAR 2 2012
DESPITE A NEARBY WINTER STORM...CONDITIONS SHOULD REMAIN RATHER
FAVORABLE AT BOTH TAF SITES WITH JUST SOME MVFR CEILINGS TO
CONTEND WITH AT LSE THIS AFTERNOON. IFR CEILINGS HAVE LIFTED AT
RST AND SHOULD STAY VFR THROUGH THE AFTERNOON AS WELL. AS THE
SYSTEM PULLS OUT TO THE EAST THROUGH THE GREAT LAKES
TONIGHT...WINDS WILL BE ON THE INCREASE OUT OF THE WEST AS COLDER
AIR DROPS INTO THE REGION. SOME SNOW WILL BE POSSIBLE AS WELL
OVERNIGHT INTO SATURDAY WHICH WILL AT LEAST BRING CEILINGS BACK
DOWN TO MVFR WITH SOME IFR VISIBILITIES POSSIBLE DUE TO THE SNOW.
WIND GUSTS OF 20 TO 30KTS ARE EXPECTED OVERNIGHT INTO TOMORROW AT
BOTH TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1032 AM CST FRI MAR 2 2012
WI...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR WIZ061.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...04
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1032 AM CST FRI MAR 2 2012
.SHORT TERM...TODAY AND TONIGHT
1032 AM CST FRI MAR 2 2012
THE MAIN CONCERN COMING IN THIS MORNING WAS WITH WHETHER THE MAIN
BAND COULD SET UP ACROSS THE SOUTHERN PORTION OF GRANT COUNTY
WHERE WE WOULD END UP WITH ADVISORY WORTHY SNOW THERE. THE LATEST
RADAR RETURNS ALONG WITH REGIONAL OBSERVATIONS SHOW THAT THIS BAND
OF HEAVY SNOW HAS SET UP NEAR PLATTEVILLE DOWN TOWARD CEDAR RAPIDS
AND LIKELY WILL NOT SHIFT MUCH TO THE WEST THROUGH THE REST OF
TODAY AS THE DEEPENING NEGATIVELY TILTED MID LEVEL LOW LIFTS UP
INTO THE WESTERN GREAT LAKES REGION. THE 02.13Z HRRR AND PREVIOUS
RUNS HAVE BEEN FAIRLY CONSISTENT THIS MORNING WITH BRINGING THIS
SNOW BAND ACROSS SOUTHWEST WISCONSIN THIS AFTERNOON BEFORE
WEAKENING THE BAND AND TAKING IT EAST TONIGHT. WITH ABOUT A 6 HOUR
WINDOW FOR HEAVY SNOW...THINKING IS THAT THE POTENTIAL IS THERE
FOR AT LEAST 3 INCHES TO AS MUCH AS 6 INCHES WITH AN INCH PER HOUR
FALLING AT TIMES UNDER THE BAND. THEREFORE...HAVE ISSUED A WINTER
WEATHER ADVISORY FOR GRANT COUNTY WHERE THE THREAT IS THE
GREATEST. CONSIDERED ADDING RICHLAND AND ADAMS COUNTY AS
WELL...BUT THINK THAT THE BAND SHOULD STAY JUST TO THEIR EAST OR
AT WORST CATCH A SLIVER OF THE COUNTY. WILL CONTINUE TO MONITOR
CONDITIONS THROUGH THIS AFTERNOON PARTICULARLY ACROSS THESE
COUNTIES. WENT WITH AN END TIME OF 9PM TO MATCH UP WITH
NEIGHBORING END TIMES...BUT THINK THAT WE MAY BE ABLE TO END IT A
LITTLE EARLIER THAN THAT THIS EVENING.
OTHERWISE...ALSO HAD TO ADJUST THE SNOW DEVELOPING ACROSS A
SECONDARY BAND TO THE WEST OF THIS ONE FROM STEVENS POINT
SOUTHWEST TO LA CROSSE AND OELWEIN. SNOWFALL AMOUNTS ARE STILL
EXPECTED TO REMAIN AT LESS THAN AN INCH ACROSS THIS BAND.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
310 AM CST FRI MAR 2 2012
UPPER LEVEL RIDGING WILL BE OVER THE UPPER MIDWEST UNTIL LATE IN
THE PERIOD. BOTH THE ECMWF AND 02.00Z GFS SHOW A LONG WAVE TROUGH
CROSSING THE CENTRAL PART OF THE COUNTRY BUT SHOW CONSIDERABLE
DIFFERENCES ON ITS STRENGTH. A COLD FRONT SHOULD CROSS THE REGION
WEDNESDAY AND WEDNESDAY NIGHT WITH A CHANCE OF SOME PRECIPITATION
BEFORE PUSHING EAST OF THE AREA THURSDAY. TEMPERATURES AHEAD OF
THIS FRONT ARE EXPECTED TO WARM TO ABOUT 10C AT 850 MB. THE GFS
BUFKIT SOUNDING SUGGESTS THE POTENTIAL TO MIX UP TO ABOUT THIS
LEVEL WHICH COULD PUSH SURFACE TEMPERATURES WELL INTO THE 50S FOR
MUCH OF THE AREA.
&&
.AVIATION...TODAY AND TONIGHT
543 AM CST FRI MAR 2 2012
CURRENTLY...WIDESPREAD MVFR STRATOCUMULUS IN PLACE ACROSS EASTERN
MN INTO WI IN THE WAKE OF AN UPPER LEVEL DISTURBANCE ROTATING
THROUGH NORTHEAST MN/UPPER MICHIGAN. OTHERWISE...WILL BE WATCHING
A STRONG AREA OF LOW PRESSURE MOVE NORTHEAST FROM MISSOURI INTO
LOWER MICHIGAN TODAY. MAIN IMPACT ON THE KRST/KLSE TAF SITES WILL
BE CLOUDS...WITH ANY ACCUMULATING SNOW EXPECTED TO REMAIN
SOUTHEAST OF A LINE FROM NECEDAH AND PRAIRIE DU CHIEN WI THROUGH
OELWEIN IA. KLSE MAY BE CLOSE ENOUGH FOR SOME FLURRIES. MVFR CLOUD
COVER EXPECTED TO SCATTER INTO MID-CLOUD/VFR CONDITIONS AT KRST
AROUND 18Z AND AT KLSE BY 03.00Z. A MID-LEVEL TROUGH WILL THEN
PIVOT SOUTHEAST INTO THE AREA TONIGHT...BRINGING MVFR CLOUDS AND
SCATTERED -SN/FLURRY ACTIVITY AROUND 06Z AND AT KLSE AROUND 08Z.
WILL ALSO BE WATCHING FOR GUSTY WEST/NORTHWEST WINDS GOING INTO
THIS EVENING/OVERNIGHT AS THE SURFACE PRESSURE GRADIENT INCREASES.
GUSTS ARE EXPECTED TO BE IN THE 20-30KT RANGE AFTER 03Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1032 AM CST FRI MAR 2 2012
WI...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR WIZ061.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...04
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1150 PM CST THU MAR 1 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
MOVING OVER THE EASTERN GREAT LAKES...BUT WITH SURFACE TROUGHING
EXTENDING WEST INTO NORTHERN WISCONSIN. THE COMBO OF WEAK CYCLONIC
FLOW AND THERMAL TROUGHING IN THE LOW LEVELS HAS LEAD TO A ROBUST
STRATUS DECK THAT HAS HELD FIRM THROUGH EARLY THIS AFTERNOON. SOME
HOLES IN THE CLOUDS HAVE TRIED TO DEVELOP OVER THE LAKESHORE WITHOUT
MUCH LUCK. MEANWHILE...PLENTY OF INCOMING CONCERNS UPSTREAM.
NORTHERN STREAM SHORTWAVE IS SLOWLY MOVING EAST OVER THE
MONTANA/N.D. BORDER WITH LIGHT SNOW SPREADING ACROSS N.D. FARTHER
SOUTH...WEAK SHORTWAVE IMPULSES ARE MOVING WITHIN FAST SW FLOW OVER
THE CENTRAL PLAINS. ONE DISTURBANCE IS PRODUCING LIGHT SNOW OVER NE
NEBRASKA AND NW IOWA. FINALLY...THE STRONGEST SHORTWAVE IS RAPIDLY
MOVING EAST OVER UTAH/COLORADO...AND SNOW AMOUNTS/HEADLINES WITH
THIS FEATURE WILL BE THE MAIN FORECAST CONCERN.
TONIGHT...NORTHERN STREAM SHORTWAVE WILL MOVE ACROSS NORTH DAKOTA
INTO MINNESOTA AND PUSH AN UPPER LEVEL FRONT INTO NORTHWEST
WISCONSIN LATE TONIGHT. FORCING IS PRETTY WEAK...BUT GUIDANCE IS
OPTIMISTIC ABOUT GENERATING LIGHT SNOW ALONG IT. UPSTREAM OBS SNOW
THE POTENTIAL FOR LIGHT SNOW...SO WILL KEEP IT IN THE FORECAST AFTER
06Z. MEANWHILE...RELATIVELY WEAKER SOUTHERN STREAM IMPULSES WILL
RACE NORTHEAST INTO THE WESTERN GREAT LAKES. LIGHT SNOW OVER NE
NEBRASKA MAY MAKE A RUN AT CENTRAL OR EAST-CENTRAL WISCONSIN LATE AS
WELL. CONFIDENCE NOT QUITE AS HIGH WITH THIS FEATURE AS THE ONE
FARTHER NORTH...SO WILL SHOW LOWER POPS. NOT EXPECTING MUCH ACCUMS
WITH EITHER FEATURE THOUGH...PERHAPS A COUPLE TENTHS.
OTHERWISE...ANTICIPATE THE BACK EDGE OF THE LOW STRATUS WILL
ACCELERATE NORTHEAST OVER THE NORTHERN MISSISSIPPI VALLEY EARLY
TONIGHT. LOW LEVEL WIND FIELDS BECOME WEAK SO THINK THE LOW
OVERCAST WILL HANG AROUND. IF THEY DO CLEAR OVER CENTRAL AND
EAST-CENTRAL WISCONSIN (HIGHEST PROBABILITY)...MID AND HIGH CLOUDS
WILL KEEP THE SKIES OVERCAST. LOWS IN THE MID 20S TO THE LOWER 30S.
FRIDAY...CENTRAL ROCKIES SHORTWAVE WILL BE MOVING ACROSS THE CENTRAL
PLAINS AND NORTHEAST OVER THE MID-MISSISSIPPI VALLEY. IT WILL DRIVE
A RAPIDLY STRENGTHENING SURFACE LOW FROM SW MISSOURI TO NORTHEAST
INDIANA. NUISANT SMALL PRECIP CHANCES WILL LINGER OVER N-C
WISCONSIN AND CENTRAL WISCONSIN IN THE MORNING BUT THE MAIN SHOW
WILL ARRIVE IN THE AFTERNOON AS THE SURFACE LOW MOVES OVER ILLINOIS
AND INDIANA. INCREASING UPPER DIVERGENCE IN THE LEFT FRONT QUAD OF A
JETSTREAK...AND STRONG FGEN CENTERED AROUND 700MB ON THE NW FLANK OF
THE SURFACE LOW WILL LEAD TO PRECIP SPREADING NORTHEAST OVER CENTRAL
AND NORTHEAST WISCONSIN MID-AFTERNOON ONWARD. NEGATIVE EPV ABOVE
THIS FGEN LAYER WILL SUPPORT ENHANCED BANDING ACTIVITY WHICH COULD
LEAD TO LOCALLY HEAVIER SNOWFALL RATES. SOME RAIN MAY MIX IN WITH
THE SNOW OVER THE FOX VALLEY AND LAKESHORE AREAS WHERE TEMPS WILL BE
IN THE MID 30S AS THE PRECIP ARRIVES. BUT ONCE THE HEAVIER PRECIP
RATES MOVE IN...A TIGHTENING BAROCLINIC ZONE WILL LIKELY LEAD TO
RAPIDLY ACCUMULATING SNOW FOR THE EVENING COMMUTE. COULD SEE A
QUICK 1-3 INCHES OF HEAVY SNOW FOR THE FOX VALLEY AND LAKESHORE BY
00Z SATURDAY WITH LESSER AMOUNTS TO THE NORTHWEST. WILL HOIST A
WINTER STORM WATCH STARTING AT 3 PM FOR WINNEBAGO TO SOUTHERN
MARINETTE ON EAST.
.LONG TERM...FRI NGT THRU NXT THU. FAIRLY PROGRESSIVE MEAN FLOW
ACROSS THE COUNTRY AS ONE LONGWAVE TROF MOVES ACROSS THE ERN CONUS
THIS WEEKEND...TO BE FOLLOWED BY ANOTHER LONGWAVE TROF PUSHING
INTO THE WRN CONUS EARLY NXT WEEK. NE WI TO DEAL WITH INITIAL TROF
INTO THE WEEKEND...HOWEVER UPR RIDGING BETWEEN THE TWO TROFS WL
BRING A GOOD WARM-UP EARLY TO MID-WEEK. THE APPROACH OF A CDFNT
WED/THU WL BRING THE NXT BEST CHC OF SEEING WIDESPREAD PCPN.
MDLS CONT TO CONVERGE ON A STORM TRACK FROM TAKING A DEEPENING SFC
LOW ROUGHLY FROM SW LWR MI NEWD TO EXTREME SE ONTARIO FRI NGT.
ACCUMULATING SNOW WL CONT TO IMPACT PRIMARILY ERN WI WHERE AN ADDL
2 TO 4 INCHES IS PSBL DURING THE EVENING. CONVERSELY...WRN SECTIONS
OF THE FCST AREA (GENERALLY WEST OF HWY 51) WL BE LUCKY TO SEE AN
ADDL INCH OF NEW SNOW. STRONG CYCLONIC FLOW COMBINED WITH A SFC
TROF DROPPING SOUTH INTO WI WL KEEP AT LEAST A CHC OF SNOW SHWRS
ACROSS THE FCST AREA THRU THE OVRNGT PERIOD.
THE WEAK SFC TROF SAGS SWD TOWARD SRN WI ON SAT WITH A WEAKENING
CYCLONIC FLOW HANGING ON OVER THE WRN GREAT LKS. FURTHERMORE...THE
LONGWAVE TROF WL BE MOVING INTO THE REGION WITH SEVERAL EMBEDDED
SHORTWAVES PUSHING THRU WI. FINALLY...MID-LVL LAPSE RATES GET
PRETTY STEEP ADDING INSTABILITY TO THE ATMOSPHERE. ADD ALL THIS UP
AND WE ARE LOOKING AT A DECENT CHC OF SNOW SHWRS THROUGHOUT ALL OF
NE WI. WOULD NOT BE SURPRISED TO SEE A FEW LOCALLY HEAVIER SNOW
BURSTS WITH PERHAPS A QUICK ONE-HALF INCH TO AN INCH OF ACCUMULATION.
MAX TEMPS TO BE COOLER THAN PREV DAYS WITH READINGS TOPPING OUT IN
THE LWR TO MID 30S.
SNOW SHWRS SHOULD BECOME MORE ISOLATED IN NATURE SAT NGT AS THE SFC
TROF PULLS AWAY AND THE LOSS OF DAYTIME HEATING MINIMIZES THE
INSTABILITY. SKIES TO REMAIN MOSTLY CLOUDY THRU THE NGT...HOWEVER
ENUF COOL AIR TO HAVE SETTLED OVER THE REGION TO ALLOW TEMPS TO
DROP INTO THE TEENS NORTH/CENTRAL...NEAR 20 EAST-CENTRAL. THE
LONGWAVE TROF TO STILL BE SITUATED OVER THE GREAT LKS THRU SUNDAY...
THEREBY PROVIDING A MEAN NW FLOW ACROSS WI. A PROMINENT SHORTWAVE
IS FCST TO DIVE SE FROM MN TO NRN IL WITH EVEN A SEMBLENCE OF A WEAK
SFC LOW MOVING SE THRU IA. EXPECT TO SEE SCT SNOW SHWRS OVER MUCH OF
NE WI ON SUNDAY WITH MAX TEMPS ONLY REACHING THE MID 20S NORTH/
AROUND 30 CENTRAL/E-CENTRAL.
ANY SNOW SHWR ACTIVITY SHOULD DIMINISH SUNDAY EVENING AS THE
SHORTWAVE DIVES TOWARD THE OHIO RIVER VALLEY AND INSTABILITY
WEAKENS UPON SUNSET. AS HI PRES BUILDS ACROSS THE MIDWEST LATER
SUNDAY NGT...SKIES WL ATTEMPT TO BECOME PARTLY CLOUDY OVER AT LEAST
CENTRAL WI BRINGING ANOTHER COLD NGT TO THE FCST AREA. THE HI PRES
DRIFTS ACROSS WI ON MON AND WL BE SITUATED JUST TO OUR EAST BY 00Z
TUE. WINDS BACKING S-SW WL START TO TAP WARMER AIR TO OUR WEST...
BUT COOLS START TO THE DAY WL ONLY BRING MAX TEMPS ON MON INTO THE
30-35 DEG RANGE. AS THE HI PRES HEADS TOWARD THE ERN CONUS ON TUE...
A STRONG AREA OF LOW PRES WL BE MOVING ACROSS S-CENTRAL CANADA. A
TIGHT PRES GRADIENT TO EXIST ACROSS THE GREAT LKS...BRINGING
BLUSTERY CONDITIONS TO NE WI. THESE GUSTY S-SW WINDS WL ALSO DRAW
VERY MILD AIR INTO WI WITH 8H TEMPS CLIMBING TO NEAR +6C. DEPENDING
ON THE DEPTH OF THE SNOW COVER...MAX TEMPS SHOULD EASILY RISE INTO
THE 40S WITH ANY SNOW-FREE AREAS SURPASSING THE 50 DEG MARK.
THE NXT LONGWAVE TROF TO BE IN THE PROCESS OF PUSHING ACROSS THE
ROCKIES TUE NGT BEFORE REACHING THE NRN/CNTRL PLAINS ON WED.
PRECEDING THIS UPR TROF WL BE A CDFNT WHICH THE MDLS HAVE SOME
TIMING ISSUES WITH. LATEST TRENDS HAVE THIS FNT APPROACHING CENTRAL
WI BY WED AFTERNOON...THUS A NEED FOR CHC POPS ACROSS MOST OF NE
WI. ANOTHER MILD DAY WOULD HAVE ANY PCPN FALL AS RAIN WITH MAX
TEMPS TO RANGE FROM THE MID 40S NORTH TO AROUND 50 DEGS CENTRAL
AND EAST-CENTRAL WI. THE CDFNT DRIVES THRU MOST OF WI WED NGT WITH
A BAND OF LIGHT RAIN MIXING WITH AND CHANGING TO LIGHT SNOW AS
COOLER AIR ARRIVES BEHIND THE FNT. SOME DEBATE LINGERS AS TO
WHETHER THIS FNT WL BE ABLE TO CLEAR THE AREA BEFORE ANY SFC WAVES
CAN DEVELOP ON THE FNT TO SLOW ITS PROGRESS. HAVE USED A GENERAL
CONSENSUS FOR THU WHICH KEEPS THINGS DRY FOR NOW...BUT THU MAY
NEED TO BE RE-EVALUATED LATER AS THE 12Z ECMWF NOW DIGS AN UPR
TROF INTO THE CNTRL CONUS AND REVS UP A SFC LOW TOWARD CHICAGO.
&&
.AVIATION...LOOK FOR MVFR CIGS AND VSBYS DUE TO SNOW AND DRIZZLE TO
SLOWLY SPREAD FROM WEST TO EAST OVERNIGHT. IFR CIGS AND VSBYS WILL
BE PATCHY EARLY FRIDAY BEFORE BECOMING MORE WIDESPREAD FRIDAY
AFTERNOON AND EVENING.
TDH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH LATE FRIDAY
NIGHT FOR WIZ022-038>040-048>050-073-074.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1131 PM CST THU MAR 1 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY
347 PM CST THU MAR 1 2012
AT 3 PM...THE WATER VAPOR IMAGERY AND PROFILER NETWORKS SHOW THAT
A SHORT WAVE TROUGH WAS MOVING ACROSS SOUTHWEST MINNESOTA AND
WESTERN IOWA. THE RUC SOUNDINGS CONTINUE TO SHOW THAT MUCH OF THE
SYNOPTIC AND ISENTROPIC LIFT ASSOCIATED WITH THIS WAVE GOES TO
SATURATION. THIS IS LIKELY THE REASON WHY THE RADARS ARE
INDICATING SOME ECHOS ACROSS SOUTH CENTRAL MINNESOTA AND NORTHEAST
IOWA. HOWEVER WITH THE AIR MASS DRY IN THE LOW LEVELS...NOT SEEING
ANYTHING REACHING THE GROUND. THIS WAVE WILL MOVE THROUGH SOUTHERN
WISCONSIN THIS EVENING...SO JUST LEFT A 20 PERCENT CHANCE OF
PRECIPITATION TO COVER THIS SYSTEM. FURTHER TO THE NORTHWEST...
ANOTHER SHORT WAVE TROUGH WAS MOVING THROUGH EASTERN NORTH DAKOTA.
THIS SYSTEM LOOKS TO BE TOO FAR NORTH AND WEST TO PRODUCE ANY
PRECIPITATION ACROSS EITHER SOUTHEAST MINNESOTA OR NORTH-CENTRAL
WISCONSIN. AS A RESULT...LOWERED THE PRECIPITATION CHANCES FOR
TONIGHT IN THESE AREAS. MEANWHILE BETWEEN THESE TWO SYSTEM WILL
LIKELY NOT SEE ANY PRECIPITATION...SO TOOK OUT THE PRECIPITATION
CHANCES OUT FOR THESE AREAS.
ON FRIDAY...THE 01.12Z MODELS ARE MUCH CLOSER TO COMING UP WITH A
CONSENSUS FORECAST. THE NAM/WRF HAS KEPT ITS IDEA THAT THERE WOULD
BE SOME PHASING BETWEEN THE NORTHERN AND SOUTHERN STREAMS...THUS...
IT HAS KEPT A STRONGER LOW PRESSURE SYSTEM. WHILE THIS HAS BEEN
CONSISTENT...IT HAS SHIFT THE SURFACE LOW MUCH FURTHER SOUTHEAST
WITH IT TRACKING FROM NORTHERN MISSOURI INTO SOUTHWEST LOWER
MICHIGAN. THIS TRACK IS MORE IN LINE WITH WHAT THE GFS...GEM...
ECMWF...AND UKMET HAVE BEEN SHOWING FOR THE PAST SEVERAL DAYS.
MEANWHILE THE GFS...GEM...ECMWF...AND UKMET ARE NOW SHOWING SOME
PHASING BETWEEN THE NORTHERN AND SOUTHERN STREAMS...SO THEY HAVE A
SIMILAR STRENGTH LOW TO THE NAM/WRF. WHILE THEY MADE THIS
CHANGE...THERE SURFACE LOW TRACK HAS REMAINED RATHER CONSISTENT.
ALL OF THE MODELS ARE SUGGESTING THAT THERE WILL BE STRONG 900 TO
700 MB FRONTOGENESIS ACROSS FAR EASTERN IOWA...NORTHWEST
ILLINOIS...AND SOUTHERN WISCONSIN. ABOVE THIS FRONTOGENESIS...
THERE IS SOME NEGATIVE EPV. AS A RESULT...EXPECTING TO SEE SOME
SLANTWISE CONVECTION TO DEVELOP. THIS INTERSECTS THE -15C OMEGA...SO
THERE WILL BE POSSIBILITY OF 1 TO 2 INCH AN HOUR SNOW RATES. THE
01.15Z SREF DOES SUGGEST THAT THERE WILL BE SOME PROBABILITIES FOR
THIS JUST TO THE EAST OF OUR FORECAST AREA. WITH ALL OF THIS IN
MIND...THINKING THAT THERE WILL BE A BAND OF 2 TO 4 INCHES OF SNOW
EAST OF A DUBUQUE IOWA TO WAUTOMA WISCONSIN LINE. IF THESE SNOW
TOTALS STILL LOOK REALISTIC TONIGHT...WE MAY HAVE TO ISSUE A
WINTER WEATHER ADVISORY FOR THIS AREA. ONE CONCERN ABOUT DOING
THIS IS THAT THE TEMPERATURES ARE ABOVE FREEZING AND THEY MAY HAVE
A HARD TIME ACCUMULATING IF THE RATES ARE NOT HIGH ENOUGH.
FROM FRIDAY NIGHT INTO SUNDAY...IT CONTINUES TO LOOK LIKE A LONG
WAVE TROUGH WILL BE LOCATED ACROSS THE REGION. EMBEDDED WEAK SHORT
WAVE TROUGHS IN THIS MAIN WAVE MAY PRODUCE PERIODIC CHANCES FOR
LIGHT SNOW. OVERALL...IF THE SNOW DOES OCCUR...NOT EXPECTING TOO
MUCH ACCUMULATIONS FROM THESE SYSTEMS.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
347 PM CST THU MAR 1 2012
ON TUESDAY...THE MODELS ARE CONTINUING TO INDICATE THAT A 500 MB
HIGH WILL DEVELOP ACROSS THE SOUTHEAST UNITED STATES. SOUTHERLY
WINDS ON THE BACKSIDE OF THIS HIGH WILL BRING WELL ABOVE NORMAL
TEMPERATURES INTO THE FORECASTS AREA. WE MAY SEE TWO TO THREE DAYS
WITH HIGH TEMPERATURES IN THE 50S. THERE MAY BE EVEN A FEW AREAS
THAT SEE TEMPERATURES IN THE 60S. SINCE THE ALL BLEND STILL HAS
SOME COLD SOLUTIONS IN IT...TRENDED THE TEMPERATURES FROM TUESDAY
NIGHT INTO WEDNESDAY TOWARD THE CONSALL INSTEAD OF THE ALL BLEND.
&&
.AVIATION...THROUGH 06Z SATURDAY
1131 PM CST THU MAR 1 2012
A LOW PRESSURE TROUGH WAS SITUATED ALONG NEAR I-35 AS OF LATE
THURSDAY EVENING. VFR CONDITIONS EXISTS AHEAD OF THE TROUGH OVER
THE TAF SITES...BUT JUST TO THE WEST OVER SOUTH CENTRAL
MINNESOTA...MVFR TO IFR CEILINGS WERE PRESENT. THESE LOWER
CEILINGS ARE LIKELY TO MAKE THEIR WAY EASTWARD INTO THE TAF SITES
IN THE 06-12Z PERIOD. CONFIDENCE IS LOW THAT THE IFR CONDITIONS
WOULD HIT EITHER TAF SITES...THOUGH...SINCE THE IFR CEILINGS ARE
PRESENT OVER AREAS THAT GOT SOME SNOW ACCUMULATION. CERTAINLY
THE POTENTIAL FOR IFR CEILINGS WILL NEED TO BE MONITORED THROUGH
THE EARLY MORNING HOURS. DRIER AIR SEEN IN SOUTHWEST MINNESOTA
IS EXPECTED TO MAKE INTO THE TAF SITES LATER TODAY...REACHING KRST
AT 18Z AND KLSE AT 00Z. THIS DRIER AIR WILL ALLOW CEILINGS TO
CLIMB TO VFR. THE REASON FOR THE DELAY AT KLSE IS A LOW PRESSURE
SYSTEM HEADING NORTHEAST THROUGH ILLINOIS. ANY PRECIPITATION FROM
THIS SYSTEM WILL STAY SOUTHEAST OF KLSE. WINDS ARE GOING TO
INCREASE AS THIS SYSTEM APPROACHES...THOUGH...AND IN FACT COULD
GET GUSTY AT KRST AFTER 03Z WHERE WEST-NORTHWEST GUSTS OF UP TO 22
KT ARE FORECAST. ACCOMPANYING THESE GUSTY WINDS SHOULD BE ANOTHER
SURGE OF LOW STRATUS WITH MVFR CEILINGS CURRENTLY IN NORTH DAKOTA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
347 PM CST THU MAR 1 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1209 AM EST SUN MAR 4 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP ON THE COLD FRONTAL
BOUNDARY THAT MOVED THROUGH THE REGION EARLIER ON SATURDAY AND PASS
WELL EAST OF NEW JERSEY TODAY. A WEAK CLIPPER LOW PRESSURE SYSTEM
SHOULD PASS OFF THE VIRGINIA AND NORTH CAROLINA COASTAL BORDER ON
MONDAY. A HIGH PRESSURE SYSTEM FROM THE ROCKIES WILL REACH THE
EASTERN SEABOARD ABOUT TUESDAY AND THEN SLOWLY DRIFT OFFSHORE
THROUGH THE MIDDLE OF THE WEEK. A SLOW MOVING COLD FRONT SHOULD
APPROACH THE REGION ON FRIDAY AND MOVE OFFSHORE BY SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THE NORTHERN EDGE OF THE PRECIPITATION SHIELD ASSOCIATED WITH THE
DEVELOPING SURFACE WAVE ALONG THE NORTH CAROLINA COAST HAS REACHED
SOUTHEAST VIRGINIA EARLY THIS MORNING. NORTH OF THAT POINT THE
AIRMASS IS FAIRLY DRY (KWAL WAS FAIRLY DRY AT 0000 UTC...AND KIAD
WAS VERY DRY). THIS WOULD SUGGEST THAT THE PRECIPITATION DEVELOPING
IN THE STRENGTHENING MID LEVEL FRONTOGENETIC FORCING WILL STAY
SOUTHEAST OF THE AREA THROUGH AT LEAST 0900 UTC...SO MOST OF THE
MENTION OF PRECIPITATION WAS DROPPED FROM THE FORECAST FOR THE
OVERNIGHT HOURS. A MENTION WAS RETAINED FOR SOUTHEAST DELAWARE...
THOUGH THIS COULD BE GENEROUS...BASED ON THE LATEST HRRR RUN.
OTHERWISE...MAINLY MID AND HIGH CLOUDINESS FOR THE EARLY MORNING
HOURS. THERE IS STILL SOME GRADIENT IN PLACE...AND ONLY PROTECTED
LOCATIONS HAVE GONE CALM TO THIS POINT. THE COMBINATION OF CLOUDS
AND LIGHT WEST TO NORTHWEST GRADIENT SHOULD KEEP TEMPERATURES
FAIRLY UNIFORM OUTSIDE OF THE PROTECTED LOCATIONS. THIS IS
REFLECTED IN THE CURRENT TEMPERATURE FORECAST...SO LITTLE IN THE
WAY OF CHANGE WAS MADE FOR THE REMAINDER OF THE OVERNIGHT.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
ON SUNDAY, THE LOW PRESSURE THAT DEVELOPS ALONG THE FRONT OFFSHORE
SHOULD MOVE FURTHER AWAY FROM THE AREA. THIS SHOULD TAKE ANY
REMAINING PRECIPITATION OUT TO SEA WITH IT DURING THE DAY. BY THE
AFTERNOON, ANY PRECIPITATION ACROSS THE SOUTHERN AREAS SHOULD BE
ENDING.
AS WE MOVE INTO THE AFTERNOON, A BROAD TROUGH ALOFT BEGINS TO SWING
TOWARD OUR AREA, ALONG WITH A WEAK SURFACE BOUNDARY. WITH THE
WEST-SOUTHWEST FLOW ALOFT, THERE MAY BE ENOUGH MOISTURE IN THE AREA
THAT COMBINED WITH THE FRONTAL BOUNDARY, SOME RAIN/SNOW SHOWERS MAY
AFFECT OUR NORTHWESTERN ZONES, AND SOME FLURRIES OR SPRINKLES MAY
MOVE AS FAR SOUTH AS THE PHILLY METRO AREA. MOST OF THE MODEL
GUIDANCE KEEPS ANY PRECIPITATION LIGHT AND MOSTLY CONFINED TO OUR
NORTHWESTERN ZONES. AS WITH THIS TIME OF YEAR, IF ANY SNOW OCCURS IN
THE HIGHER ELEVATIONS, IT COULD BECOME MEASURABLE. RIGHT NOW WE
WOULD NOT EXPECT MUCH MORE THAN A HALF AN INCH OR SO FOR THE
AFTERNOON.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
A COLD START AND A MILDER FINISH TO THE LONG TERM. PRETTY CONFIDENT
ABOUT WARMER THAN NORMAL WEATHER END OF THE WEEK AS ALL OF THE
FORECAST TELECONNECTION INDICES (POS NAO AND EPO, NEG PNA) AND THE
MADDEN JULIAN OSCILLATION ENTERING PHASE 4 ARE IN EXCELLENT
CORROBORATIVE AGREEMENT. AT THE START OF THE LONG TERM WE LEANED
MORE TOWARD THE GFS THAN THE WRF-NNMB OFF ITS BETTER INITIALIZATION.
A WEAKENING FRONTAL BOUNDARY OR TROF WILL BE WORKING ITS WAY INTO
OUR CWA AS SUNDAY NIGHT BEGINS. THERE IS A HINT OF A BIT OF
RELATIVELY HIGHER INSTABILITY DURING SUNDAY EVENING NORTH AND WE
CARRIED CHANCE POPS OVER THE HIGHER TERRAIN. IT WOULD NOT BE OUT OF
THE QUESTION FOR A COATING IN THOSE AREAS. ELSEWHERE THE COMBINATION
OF SOME CLOUDINESS AND WINDS SHOULD KEEP TEMPERATURES FROM BOTTOMING
AND THIS IS REFLECTED IN THE CURRENT STAT GUIDANCE AND FORECAST.
NO CHANGE TO MONDAY`S FORECAST AS OUR CWA SHOULD BE ALONG THE
NORTHERN EDGE OF A CLIPPER TYPE SYSTEM. MOST OF THE GFS`S
DIAGNOSTICS FOR HEAVIER PCPN ARE SOUTH OF OUR CWA: THETA E RDG, H2.5
AND H7 JETS, ISENTROPIC LIFT 850MB-700MB, TROWAL AND MID LEVEL FGEN
AXIS. THE ONE FEATURE THAT IS FARTHER TO THE NORTH IS THE FCST MID
LVL QVEC CONVERGENCE WHICH JUST GETS INTO OUR CWA. THERE IS A
CONVECTIVE "LOOK" TO THE PCPN AS THERE WILL BE FAIRLY STEEP LAPSE
RATES BETWEEN 850MB AND 500MB. THE PROBLEM FOR OUR CWA IS THAT MOST
OF THE LOW LEVEL SYNOPTIC SCALE LIFT IS SOUTH, SO WHILE THE
ATMOSPHERE WOULD BE CONDUCIVE, THE TRIGGER IS MISSING. THICKNESS
VALUES ALONE PTYPE WOULD BE SNOW. BUT BECAUSE THE BOUNDARY LAYER
SHOULD BE WARM, WE CARRIED MIXED PCPN. IN A PERFECT SCENARIO WORLD
THE PCPN WOULD BE RAIN WHEN LIGHT AND CHANGE TO SNOW WITH ANY
INCREASE IN INTENSITY. WE WERE CONSERVATIVE WITH MAX TEMPS
BASED ON FCST 925MB TEMPS.
THE CLIPPER TYPE LOW PASSES OFFSHORE ON MONDAY NIGHT AND THE
GRADIENT IS FORECAST TO TIGHTEN AGAIN. THERE WILL BE A FAIRLY
SUBSTANTIAL CHANNELIZED VORT LOBE FORECAST TO MOVE THROUGH. THE
FORECAST AVAILABLE MOISTURE IS VERY LOW, SO BASICALLY THAT VORT
WOULD BE SPINNING CONDENSATION NUCLEI. WE DID NOT BOTTOM THE MINS
FOR THE SAME REASON AS SUNDAY NIGHT, ALTHOUGH A SLIGHTLY FASTER
SOLUTION WOULD BRING BETTER RADIATIONAL COOLING CONDITIONS INTO OUR
CWA. A SUNNY DAY IS FORECAST FOR TUESDAY. WINDS SHOULD BE LIGHT, SO
SHOULD NOT MIX SOME OF THE WARMER AIR ALOFT DOWNWARD. AGAIN WE WERE
PRETTY CONSERVATIVE WITH MAX TEMPS. THEN IDEAL RADIATIONAL COOLING
CONDITIONS ARE EXPECTED FOR TUESDAY NIGHT UNDER CLEAR SKIES.
AFTER A CHILLY START TO WEDNESDAY, THE MODERATING TREND WILL START
AND WE WENT ABOVE STAT GUIDANCE AWAY FROM THE SHORE. FOR WEDNESDAY
NIGHT MINS, THEY WERE INCREASED. WE FOLLOWED A 50/50 COMPROMISE
BETWEEN HPC AND CONTINUITY AS NOT CONFIDENT ABOUT EITHER LOW CLOUDS
FORMING OR WINDS BEING STRONG ENOUGH TO PREVENT SOME RADIATIONAL
COOLING. WHETHER THE LOW CLOUDS FORM OR NOT, THE STRONG SOUTHWEST
FLOW AND THE LACK OF A FORECAST INVERSION SHOULD GIVE US SOME DEEPER
MIXING AND THUS WE WENT ABOVE STAT GUIDANCE AGAIN FOR MAX TEMPS ON
THURSDAY.
THE COLD FRONT WILL BE APPROACHING AND PASSING THROUGH OUR CWA ON OR
ABOUT FRIDAY. THE MODEL TREND WAS SLIGHTLY FASTER OFF THE 00Z RUN
BUT NOW SLOWED AGAIN WITH THE 12Z RUN. LESS CONFIDENCE THAN AVERAGE
ABOUT THE FORECAST TEMPS AND SENSIBLE WEATHER FOR FRIDAY INTO
SATURDAY. THERE IS ALSO A DIFFERENCE AS TO HOW WET AND WAVY A SYSTEM
THIS WILL BE. THE HIGH PRESSURE SYSTEM BEHIND IT IS TAKING MORE OF A
NORTHERN ROUTE TO ARRIVE, SO TEMPERATURES SHOULD FALL BACK TO
SEASONAL LEVELS IN THE WAKE OF THE COLD FRONTAL PASSAGE WHETHER ITS
ON SATURDAY OR SUNDAY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS CONTINUE ACROSS THE AREA EARLY THIS MORNING...WITH
MAINLY HIGH AND MID LEVEL CLOUDINESS. THE GRADIENT IS STILL IN
PLACE...BUT THIS SHOULD BACK OFF AS A SURFACE FRONT STALLS TO THE
SOUTHEAST.
LOW PRESSURE IS ORGANIZING ON THE FRONT NEAR THE NORTH CAROLINA
COAST. THE LOW SHOULD REMAIN FAR ENOUGH SOUTH AND EAST OF THE AREA
TO KEEP THE PRECIPITATION SHIELD OUT OF THE AREA. AS THE LOW DEEPENS
LATE THIS MORNING...THE TIGHTENING GRADIENT SHOULD RESULT IN WEST TO
NORTHWEST WINDS BECOMING GUSTY. MODEL SOUNDINGS SHOW THE POTENTIAL
FOR GUST TO 25 KNOTS BETWEEN 1700 AND 2300 UTC.
VFR CEILINGS WILL LOWER THIS AFTERNOON TO ABOUT 5000 FEET...AND THIS
LAYER WILL REMAIN PLACE INTO THIS EVENING. THE LOWER CLOUDS SHOULD
ERODE THIS EVENING...WITH MID AND HIGH CLOUDINESS ABOVE THAT. THE
GUSTY WINDS WILL DIMINISH AFTER 0000 UTC...WITH VFR CONDITIONS
EXPECTED THROUGH 1200 UTC MONDAY.
OUTLOOK...
GENERALLY VFR CONDITIONS ARE EXPECTED TO PREVAIL INTO WEDNESDAY.
THERE COULD BE SOME SNOW SHOWERS NORTH OF OUR TERMINALS ON SUNDAY
NIGHT. A WEAK SYSTEM SHOULD PASS SOUTH OF THE TERMINALS ON MONDAY,
WITH A CHANCE OF SOME MVFR CIGS OR VSBYS IN DELMARVA. THE
NEXT CHANCE FOR MVFR CONDITIONS WOULD BE WEDNESDAY NIGHT OR THURSDAY
MORNING AS RETURN FLOW AROUND A HIGH PRESSURE SYSTEM BRINGS SOME
LOWER LEVEL MOISTURE INTO THE AREA.
&&
.MARINE...
HAVE DROPPED THE SMALL CRAFT ADVISORY ON DELAWARE BAY SINCE WINDS
ARE BELOW CRITERIA AND SHOULD REMAIN SO AT LEAST THROUGH SUNDAY.
WINDS HAVE ALSO DROPPED BELOW ADVISORY CRITERIA ON OUR OCEAN WATERS,
BUT SEAS ARE STILL ABOVE 5 FT. THE ADVISORY WILL REMAIN IN EFFECT
THERE THROUGH THE NIGHT, ALTHOUGH THE MIDNIGHT SHIFT FORECASTER
COULD LOWER IT IF SEAS DROP0- BELOW CRITERIA.
ON SUNDAY, THE WINDS AND WAVES ARE FORECAST TO BE BELOW SMALL CRAFT
ADVISORY CRITERIA. THE PRESSURE GRADIENT ON THE WEST SIDE OF THE LOW
PRESSURE SYSTEM OFFSHORE SHOULD BE WEAK ENOUGH NOT TO SIGNIFICANTLY
INCREASE WINDS, AND WINDS FROM ALOFT SHOULD NOT MIX DOWN TO CREATE
WIND GUSTS MORE THAN 20 KNOTS.
OUTLOOK...
WINDS COULD RAMP UP TO SMALL CRAFT ADVISORY LEVELS AGAIN ON SUNDAY
NIGHT, ESPECIALLY ALONG THE COAST IN THE WAKE OF THE DEPARTING LOW
ON THE FRONT. WINDS SHOULD DECREASE BELOW SMALL CRAFT ADVISORY
LEVELS ON MONDAY AND POSSIBLY REACH THEM AGAIN AS THE CLIPPER TYPE
LOW MOVES OFFSHORE ON MONDAY NIGHT. GREATER CHANCE ON THE OCEAN VS
DELAWARE BAY. THEN TRANQUIL CONDITIONS FOR MARCH ARE EXPECTED ON
TUESDAY INTO WEDNESDAY. WE MIGHT COME CLOSER TO SMALL CRAFT ADVISORY
CONDITIONS LATER WEDNESDAY INTO THURSDAY AS A COLD FRONT APPROACHES.
WE DO HAVE SMALL CRAFT CRITERIA GUSTS BEING REACHED IN THE
DETERMINISTIC FORECAST, BUT ADMITTEDLY CONFIDENCE IS NOT HIGH AS THE
INCREASINGLY WARMER AIR MASS MAY CAP THE ABILITY FOR THESE STRONGER
GUSTS TO MIX DOWN.
&&
.EQUIPMENT...
THE KDIX WSR 88D IS BACK IN SERVICE. THE PHL TDWR REMAINS
UNAVAILABLE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR ANZ450>455.
&&
$$
SYNOPSIS...GIGI/GORSE
NEAR TERM...HAYES
SHORT TERM...ROBERTSON
LONG TERM...GIGI
AVIATION...GIGI/HAYES
MARINE...GIGI/ROBERTSON
EQUIPMENT...GIGI
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1043 PM MST SAT MAR 3 2012
.UPDATE...
ISSUED AT 746 PM MST SAT MAR 3 2012
JUST COMPLETED AN UPDATE. FAIRLY COMPLICATED LOW TEMPERATURE
FORECAST HAS DEVELOPED. WINDS HAVE DROPPED OFF DRAMATICALLY AND
LESS THAT WAS EARLIER DEPICTED. ALSO INCOMING SHORTWAVE TROUGH AND
LEFT FRONT QUADRANT OF MID/UPPER LEVEL JET IS PRODUCING A THICK
MID LEVEL CEILING. WHERE THERE ARE NO CLOUDS THE TEMPERATURES HAVE
DROPPED TO NEAR FORECAST MINS. WHERE THE CLOUDS ARE AT...TEMPERATURES
HAVE DROPPED LITTLE. CLOUDS ARE EXPECTED TO DECREASE BETWEEN 06Z
AND 09Z. HOWEVER BY THAT TIME THE WEST WINDS IN ADVANCE OF THE
NEXT SURFACE TROUGH START INCREASING.
BELIEVE THE BEST OPPORTUNITY FOR A CONTINUED DROP WILL BE RIGHT
NOW AND IN THE SOUTHERN AND WESTERN SECTIONS WHERE THE BEST
RADIATIONAL SETUP WILL OCCUR. DID LOWER TEMPERATURES A FEW DEGREES
ESPECIALLY IN THE ABOVE SPECIFIED AREAS BUT THAT IS PROBLEMATIC
DEPENDING ON HOW THE WIND/CLOUD SCENARIO EVOLVES. MOSGUIDE IS
CATCHING THE CLOUD COVER THE BEST AND MATCHES WELL WITH THE
EXPECTED LIFT AND USED THAT TO UPDATE THE CLOUD COVER THROUGH
TOMORROW MORNING.
FOR THE REST OF TONIGHT...USED THE LATEST RUC SINCE IT IS
DEPICTING THE CURRENT SITUATION VERY WELL RIGHT NOW. NEW NAM IS
ROLLING IN AT THIS TIME. THERE WAS SOME CONCERN EXPRESSED BY THE
DAY SHIFT ON NEEDING A WIND ADVISORY FOR TOMORROW. WAS EARLIER
LEANING TOWARD DOING THAT. HOWEVER...THE NEW NAM IS A LITTLE LESS
WINDY THAN THE PREVIOUS RUNS. PLUS MODELS OVERDID THE MIXING AND
WINDS YESTERDAY. PLUS CURRENT MODEL DATA IS NOT SHOWING A LOT OF
SUBSIDENCE DURING THE DAY TOMORROW WITH MOST OF THAT OCCURRING
VERY LATE TONIGHT. SO SOME DOUBT ABOUT THE NEEDED ADVISORY BUT
WILL BE CLOSE. SO ADJUSTED WINDS DOWN SLIGHTLY AND A LITTLE BELOW
ADVISORY CRITERIA. WILL LET NIGHT SHIFT LOOK AT OVERNIGHT DATA TO
ASSESS THE NEED FOR AN ADVISORY. ALSO ADJUSTED DEWPOINTS WITH
NOTHING CATCHING THAT WELL RIGHT NOW.
UPDATE ISSUED AT 439 PM MST SAT MAR 3 2012
FORECAST WAS UPDATED EARLIER DUE TO THE EARLY CANCELLATION OF THE
WIND ADVISORY AND RED FLAG WARNING.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 228 PM MST SAT MAR 3 2012
SKY COVER HAS INHIBITED HEATING AND MIXING TODAY. AM KEEPING THE
WIND ADVISORY INTACT THROUGH LATE AFTERNOON AS IT IS STILL POSSIBLE
SOME OF THE STRONGER WINDS ALOFT MAY MIX TO THE SURFACE WITH VIRGA
BEING OBSERVED AND AREAS OVER THE FAR WESTERN CWA CURRENTLY AT OR
NEAR CRITERIA.
EXPECT SKY COVER TO DECREASE OVERNIGHT AS WE LOSE DAYTIME HEATING
AND THE CU FIELD. ALSO EXPECT HIGH CLOUDS STREAMING THROUGH THE
NORTHWEST FLOW ALOFT TO BEGIN MOVING OFF TO THE EAST OVERNIGHT AND
SUNDAY AS THE UPPER RIDGE MOVES FROM THE FAR WESTERN UNITED STATES
INTO POSITION OVER THE INTER-MOUNTAIN WEST. EXPECT THE CENTRAL HIGH
PLAINS REGION TO REMAIN DRY WITH TEMPERATURES WARMING AS WE COME
UNDER A GREATER INFLUENCE OF THE UPPER RIDGE.
WINDS ARE EXPECTED TO DROP AROUND SUNSET...BUT WILL INCREASE AGAIN
AFTER MIDNIGHT. WINDS WILL BE A CONCERN ON SUNDAY AS THE STRONGEST
PRESSURE GRADIENT MOVES EASTWARD OVER THE FORECAST AREA. WITH
WARMER TEMPERATURES AND UNIDIRECTIONAL FLOW...EXPECT MORE OF THE
STRONGER WINDS TO MIX DOWN THAN THEY MAY BE TODAY....ESPECIALLY OVER
THE EASTERN/NORTHEASTERN HALF OF THE FORECAST AREA WHERE A WIND
ADVISORY MAY BE NEEDED. WILL NOT ISSUE ONE AT THIS POINT SINCE IT
HAS NOT BEEN COORDINATED WITH SURROUNDING OFFICES AND DO NOT WANT
ANY PUBLIC CONFUSION WITH THE ONE STILL IN EFFECT DURING THE
REMAINDER OF THE DAY TODAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 228 PM MST SAT MAR 3 2012
DRY CONDITIONS AND WARM TEMPERATURES ARE STILL EXPECTED MONDAY
AND TUESDAY WITH W/SW FLOW ALOFT AND A VERY DRY AIRMASS IN PLACE
OVER THE CENTRAL HIGH PLAINS. TEMPERATURES IN THE 70S ARE EXPECTED
BOTH DAYS...WITH TEMPS ON TUESDAY POSSIBLY REACHING THE MID/UPPER
70S IN THE SOUTH AND EAST. MAIN CONCERN WILL CONTINUE TO BE
POTENTIAL FOR RED FLAG CONDITIONS BOTH DAYS. RH VALUES CURRENTLY
FORECAST TO DROP BELOW 15 PERCENT BOTH DAYS...MAINLY ACROSS THE
WESTERN AND SOUTHERN PARTS OF THE CWA. GUSTY WINDS ARE EXPECTED
BOTH DAYS...HOWEVER THE STRONGEST WINDS ARE EXPECTED TO BE IN THE
EAST WHERE TIGHTER SURFACE GRADIENT WILL COMBINE WITH
UNIDIRECTIONAL FLOW ALOFT. THESE WINDS MAY NOT OVERLAP WITH LOW RH
FOR A LONG ENOUGH PERIOD OF TIME FOR RED FLAG TO BE MET.
A COLD FRONT WILL PASS OVER THE CWA TUESDAY NIGHT...COOLING TEMPS
TO NEAR SEASONAL NORMALS (UPPER 40S/LOW 50S) WEDNESDAY AND
THURSDAY. A SHORTWAVE TROUGH WILL PASS THROUGH THE PLAINS
WEDNESDAY AND WEDNESDAY NIGHT WHICH COULD BRING THE POTENTIAL FOR
RAIN WED AND RAIN/SNOW WED NIGHT. ECMWF ALONG WITH SUPPORT OF
ENSEMBLES CONTINUES TO SHOW A SPLIT IN THE UPPER PATTERN THAT
WOULD RESULT IN OUR CWA BEING MISSED. GFS HAS BEEN BACK AND FORTH
ON SHOWING A SIMILAR SPLIT OR AN OPEN WAVE...SO WAS NOT CONFIDENT
ENOUGH TO BUY INTO ITS WETTER SOLUTION. I KEPT PRECIP OUT OF
FORECAST FOR NOW. SHORTWAVE RIDGE IS EXPECTED TO BUILD BACK OVER
THE INTER- MOUNTAIN WEST TOWARDS THE END OF NEXT WEEK...WHICH
SHOULD BRING ABOVE NORMAL TEMPS IN THE UPPER 50S/NEAR 60 FRIDAY
AND SATURDAY.
OVERALL NOT A LOT OF HOPE FOR MEANINGFUL PRECIP ON THE HORIZON
WITH EITHER RIDGING OR WESTERLY FLOW ALOFT THROUGH THE EXTENDED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1039 PM MST SAT MAR 3 2012
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. THE MAIN STORY THROUGH
THIS FORECAST WILL BE THE WINDS. A SHORTWAVE TROUGH WILL PUSH A
SURFACE TROUGH THROUGH THE AREA. THIS WILL INCREASE THE WINDS AND
MAKE THE GUSTY AGAIN NEAR 08=09Z. THEN ONCE THE SUN COMES AND SOME
MIXING OCCURS...SUSTAINED WIND SPEEDS WILL INCREASE AROUND 7 TO 10
KNOTS. THIS WILL CONTINUE UNTIL LATE IN THE DAY WHEN SURFACE RIDGE
MOVING IN WILL CAUSE THE WINDS TO GO LIGHT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...LOCKHART
LONG TERM....DR
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
433 AM EST SUN MAR 4 2012
.SYNOPSIS...
LOW PRESSURE WILL PUSH AWAY FROM MID-ATLANTIC COAST THIS
MORNING..WITH HIGH PRESSURE BRIEFLY BUILDING IN THIS AFTERNOON
AND TONIGHT. A QUICK MOVING LOW PRESSURE SYSTEM WILL APPROACH THE
REGION LATE TONIGHT...TRACKING ACROSS THE VIRGINIA...NORTH
CAROLINA BORDER MONDAY. HIGH PRESSURE RETURNS MONDAY NIGHT AND
TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST IR/WV IMAGERY SHOWING AMPLIFYING UPPER LEVEL TROUGH PUSHING
ACROSS/INTO THE LOWER MISSISSIPPI VALLEY THIS MORNING. TO THE
SOUTHEAST...OLD COLD FRONTAL BOUNDARY REMAINS STALLED JUST OFF THE
CAROLINA/SOUTHEAST COAST WITH A WEAK SFC REFLECTION MOVING ALONG
IT JUST OFF THE NC COAST. BACKING SOUTHERLY FLOW IN MID LEVELS,
OWING TO ARRIVING TROUGH FROM THE WEST, HAS ALLOWED FOR A NARROW
BAND OF SHRAS TO DEVELOP THIS MORNING. AS EXPECTED, THIS ACTIVITY
HAS REMAINED MAINLY ACROSS CAROLINAS INTO SE VA...OR MAINLY FROM
EMV TO ORF TO WAL ACROSS AKQLAND. HAVE ALLOWED FOR CATEGORICAL
POPS THROUGH MID MORNING OVER THESE AREAS, BUFFERED BY SLIGHT TO
LOW CHC POP FOR THE REST OF THE MORNING JUST TO THE NORTH INTO
SOUTHERN EXTENT OF RIC METRO INTO THE NORTHERN NECK AND ATLANTIC
COASTAL SIDE OF MD EASTERN SHORE (MAINLY ALONG/EAST OF HIGHWAY
113). GRADUALLY DIMINISH POP FOR LATE MORNING INTO THE EARLY AFTN
AS BEST FORCING GETS SHUNTED OFFSHORE AS TROUGH TO THE WEST PIVOTS
EAST.
ANOTHER ROUND OF SHOWERS EXPECTED PER BOTH THE HRRR AND NAM12 EAST
OF I-95 AS THE UPPER TROUGH AXIS SWINGS THROUGH THIS
AFTERNOON, AND HAVE ALLOWED FOR A BRIEF PERIOD OF SHOWERS DURING
THE 18-22Z PERIOD. OTHERWISE A WEST TO EAST IMPROVING TREND IS
EXPECTED FOR THE AFTN. MODEL SOUNDINGS INDICATING STRONG COOLING
ALOFT AS TROUGH APPROACHES AND SFC TROUGH SLIDES NE AWAY FROM THE
REGION. HAVE NOT ACCOUNTED FOR THIS IN THE FORECAST DUE TO LOW
PROBABILITY, BUT WOULD NOT BE SURPRISED TO SEE A FEW WET
SNOWFLAKES MIX IN WITH RAIN SHRAS AS PCPN ENDS THIS AFTERNOON.
DRIER AIRMASS PULLING IN FROM THE WEST SHOULD MAKE ANY PCPN RATHER
SPOTTY, AND WARM BL WILL OBVIOUSLY PRECLUDE ANY SNOWFALL
ACCUMULATION ISSUES TODAY.
FOR HIGHS...TEMPERATURES WILL BE CHALLENGING TODAY ESPECIALLY THIS
AFTERNOON. TEMPERATURES ARE ALREADY RUNNING 2-3 DEGREES WARMER
THAN LAMP/HRRR NUMBERS AND HV ACCORDINGLY STAYED ON THE WARM SIDE
FOR THE MORNING. DOWNSLOPE FLOW INLAND AS SYSTEM EXITS SHOULD
MAKE FOR DRYING/CLEARING CONDITIONS AND AT LEAST A PARTLY SUNNY
SKY INLAND. HAVE STAYED CLOSE TO MET/MAV BLEND OVER THIS AREA,
WITH LOW 50S FROM PREVIOUS FORECAST GENERALLY ACCEPTED WEST OF
I-95. CLOSER TO THE COAST, WITH LOW CLOUDS AND SHOWERY CONDITIONS
EXPECTED TO LAST A BIT LONGER, HAVE GONE CLOSE TO THE MAV
NUMBERS...AS NAM CONTINUES TO SEEMINGLY OVER-EMPHASIZE DYNAMICAL
COOLING ALONG THE COAST. HIGHS IN THE UPPER 40S TO NEAR 50 AT THE
COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
CLEARING SKY EARLY THIS EVENING WITH SHORT-LIVED LULL ON THE BACK
SIDE OF DEPARTING SYSTEM. TEMPERATURES LOOK TO FALL RATHER QUICKLY
SUNDAY NIGHT AS WINDS BRIEFLY DROP OFF AND SKY REMAINS CLEAR EARLY
IN THE EVENING. EXPECT CLOUDS TO INCREASE FROM WEST TO EAST LATE
TONIGHT AHEAD OF VIGOROUS MID-LEVEL TROUGH WHICH WILL SLIDE ACROSS
THE CENTRAL APPALACHIANS TOWARDS THE REGION LATE TONIGHT.
MODELS NOW IN RELATIVELY GOOD AGREEMENT WITH THIS TROUGH (CLIPPER
SYSTEM) AS IT CROSSES THE MID ATLANTIC MONDAY...WITH THE
ASSOCIATED SURFACE LOW TRACKING ACROSS/JUST SOUTH OF THE VA/NC
BORDER. THE THERMAL PROFILE ALOFT CRASHES WITH THIS
SYSTEM...1000-500MB THICKNESS VALUES AROUND 5250M AND LOW-LEVEL
THICKNESS VALUES RANGE FROM AROUND 1290M N...TO 1310M S. THIS
WOULD SUPPORT THE POSSIBILITY OF A PERIOD OF LIGHT SNOW AS PCPN
ARRIVES AFTER 09Z/MONDAY. AT THIS POINT THE PRECIP TYPE GENERALLY
REFLECTS SREF PROBABILITIES...WHICH HAVE TRENDED UPWARDS NICELY
WITH THE 21Z/03 SUITE, ALTHOUGH AGREE WITH HPC THAT THIS IS LIKELY
ATTRIBUTABLE AT LEAST IN PART TO THE (LIKELY ERRONEOUSLY) COLDER
NAM MEMBERS. STILL...CONFIDENCE IS HIGH ENOUGH TO INCREASE TO HIGH
CHC TO LIKELY POP WEST OF RIC METRO MONDAY MORNING...WITH HIGH CHC
POP FOR MAINLY LIQUID PCPN LATER MONDAY MORNING. QPF WITH THIS
EVENT WILL BE RATHER LOW, ON THE ORDER OF TWO TENTHS OR LESS AS
PER SREF ENSEMBLES. TIMING OF THIS EVENT, WITH LIGHT SNOW
BEGINNING JUST PRIOR TO DIURNAL HEATING SHOULD AT LEAST PARTIALLY
NEGATE MARGINAL BL TEMPERATURES INITIALLY, LEAVING THE POTENTIAL
FOR A LIGHT SNOWFALL ACCUMULATION (~1") ON GRASSY/ELEVATED SFCS
MONDAY MORNING BEFORE QUICKLY MIXING AND TURNING OVER TO RAIN
LATER MONDAY MORNING.
GIVEN EARLY MARCH SUN ANGLE AND MARGINAL BL CONDITIONS, HEAVIER
SNOW RATES WOULD BE NEEDED FOR ANY ACCUMULATIONS ALONG AND EAST OF
THE I-95 CORRIDOR, AND FORECAST CONFIDENCE NOT HIGH AT ALL FOR
THAT OCCURRING. CLEARING COMES QUICKLY BEHIND THE SYSTEM...BY
LATE MORN INLAND INTO THE LATE AFTN COASTAL ZONES. FOR TEMPERATURES,
LOOK FOR HIGHS MONDAY MID/UPPER 40S.
HIGH PRESSURE BUILDS IN FROM THE WEST MONDAY NIGHT AND BECOMES
CENTERED OVER THE MID ATLANTIC TUESDAY BRINGING COOL PLEASANT
CONDITIONS. LOW TEMPERATURES TUESDAY MORNING SHOULD RANGE FROM THE
MID 20S TO LOW 30S...FOLLOWED BY HIGHS IN THE MID 40S EASTERN
SHORE...TO LOW 50S PIEDMONT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL BE CENTERED OVER THE MID ATLANTIC WEDNESDAY
DRIFTING SLOWLY EAST WEDNESDAY NIGHT AND THURSDAY. TEMPERATURES
WILL REBOUND INTO THE LOW TO MID 60S WITH LOWS MODERATING IN THE
LOW TO MID 40S WEDNESDAY NIGHT WITH DEEPENING SOUTHERLY FLOW.
SOUTHERLY FLOW INCREASES THURSDAY AS THE REGION BECOMES SQUEEZED
BETWEEN THE HIGH MOVING OFFSHORE AND THE NEXT APPROACHING STORM
SYSTEM. EVEN WITH SOME INCREASING HIGH CLOUDS THURSDAY
TEMPERATURES WILL WARM INTO THE UPPER 60 TO LOWER 70S.
CHANCES FOR PRECIPITATION WILL HOLD OFF UNTIL LATE FRIDAY OR
SATURDAY. THERE IS MUCH DISAGREEMENT IN THE MODELS REGARDING THE
FORECAST FOR FRIDAY AND SATURDAY. THE ECMWF HAS BEEN MUCH MORE
AMPLIFIED WITH THE NEXT UPPER TROUGH THAN THE GFS AND CANADIAN. IN
RESPONSE THE ECMWF DEVELOPED A SURFACE WAVE OVER THE SOUTHEAST
BRINGING IT INTO THE MID ATLANTIC FRIDAY NIGHT. THE GFS IS WEAKER
AND SLOWER WITH THE SYSTEM HOLDING OFF THE RAIN UNTIL SATURDAY.
THERE WILL BE DISTURBED WEATHER IN THE EXTENDED WITH GOOD CHANCES
FOR PRECIPITATION AT SOME POINT FROM LATE FRIDAY THROUGH SATURDAY.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...LIGHT RAIN WAS OVER MUCH OF THE EASTERN HALF OF THE
CAROLINAS AND WAS REPORTED AT BOTH ORF AND ECG. IN NORTH CAROLINA...
VFR CONDITIONS (ABV 3K FT AND 5 MILES) PREVAIL EXCEPT ALONG THE
IMMEDIATE COAST...EVEN WHERE A FEW HUNDREDTHS OF AN INCH OF RAIN
PER HOUR IS BEING REPORTED. LITTLE CHANGE WAS MADE TO THE EARLIER
TAFS EXCEPT TO ADJUST TIMING OF PCPN SLIGHTLY AND TO RAISE CEILINGS
A BIT. NO IFR IS IN ANY OF THE FORECASTS. ALTHOUGH LIGHT RAIN IS
MENTIONED FOR RIC AND SBY...CONFIDENCE IN THAT OCCURRING AT EITHER
LOCATION IS LOW TO MEDIUM. RAIN ENDS FROM THE WEST LATE SUNDAY
MORNING. CONDITIONS IMPROVE TO VFR SUNDAY AFTERNOON BUT OVERCAST IS
EXPECTED TO REMAIN. WINDS WILL GENERALLY RUN 10 KNOTS OR LESS
THROUGH THE PERIOD.
OUTLOOK...A SHORT WAVE AND ASSOCIATED CLIPPER LOW PRESSURE SYSTEM
WILL AFFECT THE AREA MONDAY MORNING. SOME LIGHT SNOW OR RAIN WILL BE
POSSIBLE...MAINLY ACROSS SRN PORTIONS OF THE AREA. MVFR/IFR
CONDITIONS ARE EXPECTED WITH THE PCPN. ONCE THIS SYSTEM CLEARS THE
COAST LATE MONDAY...EXPECT VFR TO PREVAIL THROUGH THURSDAY.
&&
.MARINE...
SEAS HAVE DROPPED BELOW 5 FEET AND AS A RESULT NO HEADLINES ARE IN
EFFECT. A WEAK NORTHERLY SURGE WILL MOVE THROUGH THE WATERS THIS
MORNING BUT SHOULD STAY BELOW SCA CRITERIA. WINDS INCREASE OUT OF
THE WEST ONCE AGAIN EARLY MONDAY MORNING AND MARGINAL SCA FOR WINDS
AND SEAS ARE POSSIBLE. CONFIDENCE TOO LOW TO ADD SCA AT THIS TIME.
CLIPPER SYSTEM TO MOVE THROUGH THE AREA MONDAY. AS THIS MOVES
OFFSHORE LATE MONDAY...THE SURFACE LOW WILL INTENSIFY. WINDS
INCREASE OUT OF THE NW AND SCA CRITERIA IS LIKELY MONDAY EVENING
THROUGH EARLY TUESDAY ACROSS ALL OF THE WATERS. NO OTHER MARINE
ISSUES APPEAR THROUGH MID WEEK.
&&
.HYDROLOGY...
MINOR FLOODING CONTINUES AT THE WESTHAM GAGE AT RICHMOND. RIVER
LEVELS WILL CONTINUE DROPPING TODAY...BELOW FLOOD STAGE BY EARLY
AFTN. SEE WBCFLSAKQ FOR MORE INFORMATION.
&&
.CLIMATE...
SEE WBCPNSAKQ FOR DETAILS ON METEOROLOGICAL WINTER (DEC-FEB) AT
RICHMOND AND NORFOLK (BOTH BEING 4TH WARMEST ON RECORD).
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAM/AJZ
LONG TERM...JAO
AVIATION...LSA
MARINE...LSA
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
409 AM EST SUN MAR 4 2012
.SYNOPSIS...
LOW PRESSURE WILL PUSH AWAY FROM MID-ATLANTIC COAST THIS
MORNING..WITH HIGH PRESSURE BRIEFLY BUILDING IN THIS AFTERNOON
AND TONIGHT. A QUICK MOVING LOW PRESSURE SYSTEM WILL APPROACH THE
REGION LATE TONIGHT...TRACKING ACROSS THE VIRGINIA...NORTH
CAROLINA BORDER MONDAY. HIGH PRESSURE RETURNS MONDAY NIGHT AND
TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST IR/WV IMAGERY SHOWING AMPLIFYING PUSHING ACROSS/INTO THE
LOWER MISSISSIPPI VALLEY THIS MORNING. TO THE SOUTHEAST...OLD COLD
FRONTAL BOUNDARY REMAINS STALLED JUST OFF THE CAROLINA/SOUTHEAST
COAST. BACKING SOUTHERLY FLOW OWING TO ARRIVING TROUGH FROM THE
WEST HAS ALLOWED FOR A NARROW BAND OF SHRAS TO DEVELOP THIS
MORNING. AS EXPECTED, THIS ACTIVITY HAS REMAINED MAINLY ACROSS
CAROLINAS INTO SE VA...OR MAINLY FROM EMV TO ORF TO WAL. HAVE
ALLOWED FOR CATEGORICAL POPS THROUGH MID MORNING OVER THESE
AREAS...BUFFERED BY SLIGHT TO LOW CHC POP JUST TO THE NORTH INTO
SOUTHERN EXTENT OF RIC METRO INTO THE NORTHERN NECK AND ATLANTIC
COASTAL SIDE OF MD EASTERN SHORE (MAINLY ALONG/EAST OF HIGHWAY
113). GRADUALLY DIMINISH POP FOR LATE MORNING INTO THE EARLY AFTN
AS BEST FORCING GETS SHUNTED OFFSHORE AS TROUGH TO THE WEST PIVOTS
EAST.
ANOTHER ROUND OF SHOWERS EXPECTED PER BOTH THE HRRR AND NAM12 EAST
OF I-95 AS THE UPPER TROUGH AXIS SWINGS THROUGH THIS
AFTERNOON, AND HAVE ALLOWED FOR A BRIEF PERIOD OF SHOWERS DURING
THE 18-22Z PERIOD. OTHERWISE A WEST TO EAST IMPROVING TREND IS
EXPECTED FOR THE AFTN. MODEL SOUNDINGS INDICATING STRONG COOLING
ALOFT AS TROUGH APPROACHES AND SFC TROUGH SLIDES NE AWAY FROM THE
REGION. HAVE NOT ACCOUNTED FOR THIS IN THE FORECAST DUE TO LOW
PROBABILITY, BUT WOULD NOT BE SURPRISED TO SEE A FEW WET
SNOWFLAKES MIX IN WITH RAIN SHRAS AS PCPN ENDS THIS AFTERNOON.
DRIER AIRMASS PULLING IN FROM THE WEST SHOULD MAKE ANY PCPN RATHER
SPOTTY, AND WARM BL WILL OBVIOUS PRECLUDE ANY SNOWFALL
ACCUMULATIONS.
FOR HIGHS...TEMPERATURES WILL BE CHALLENGING TODAY ESPECIALLY THIS
AFTERNOON. TEMPERATURES ARE ALREADY RUNNING 2-3 DEGREES WARMER
THAN LAMP/HRRR NUMBERS AND HV ACCORDINGLY STAYED ON THE WARM SIDE
FOR THE NEXT FEW HOURS. DOWNSLOPE FLOW INLAND SHOULD MAKE FOR
DRYING CONDITIONS AND AT LEAST A PARTLY SUNNY SKY INLAND. HAVE
STAYED CLOSE TO MET/MAV BLEND HERE, WITH LOW 50S FROM PREVIOUS
FORECAST GENERALLY ACCEPTED WEST OF I-95. CLOSER TO THE COAST,
WITH LOW CLOUDS AND SHOWERY CONDITIONS EXPECTED, HAVE GONE CLOSE
TO THE MAV NUMBERS...AS NAM CONTINUES TO SEEMINGLY OVER- EMPHASIZE
DYNAMICAL COOLING ALONG THE COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
CLEARING SKY EARLY THIS EVENING WITH SHORT-LIVED LULL ON THE BACK
SIDE OF DEPARTING SYSTEM. TEMPERATURES LOOK TO FALL RATHER QUICKLY
SUNDAY NIGHT AS WINDS BRIEFLY DROP OFF AND SKY REMAINS CLEAR EARLY
IN THE EVENING. EXPECT CLOUDS TO INCREASE FROM WEST TO EAST LATE
TONIGHT AHEAD OF VIGOROUS MID-LEVEL TROUGH WHICH WILL SLIDE ACROSS
THE CENTRAL APPALACHIANS TOWARDS THE REGION LATE TONIGHT. MODELS
NOW IN RELATIVELY GOOD AGREEMENT WITH THIS TROUGH (CLIPPER
SYSTEM) AS IT CROSSES THE MID ATLANTIC MONDAY...WITH THE
ASSOCIATED SURFACE LOW TRACKING ACROSS/JUST SOUTH OF THE VA/NC
BORDER. THE THERMAL PROFILE ALOFT CRASHES WITH THIS SYSTEM...1000-500MB
THICKNESS VALUES AROUND 5250M AND LOW-LEVEL THICKNESS VALUES
RANGE FROM AROUND 1290M N...TO 1310M S. THIS WOULD SUPPORT THE
POSSIBILITY OF A PERIOD OF LIGHT SNOW AS PCPN ARRIVES AFTER
09Z/MONDAY. AT THIS POINT THE PRECIP TYPE GENERALLY REFLECTS SREF
PROBABILITIES...WHICH HAVE TRENDED UPWARDS NICELY WITH THE 21Z/03
SUITE, ALTHOUGH AGREE WITH HPC THAT THIS IS LIKELY ATTRIBUTABLE IN
PART TO THE LIKELY ERRONEOUSLY COLDER NAM MEMBERS. STILL...CONFIDENCE
IS HIGH ENOUGH FOR HIGH CHC TO LIKELY POP WEST OF RIC MONDAY
MORNING WITH CHC POP FOR MAINLY LIQUID PCPN LATER MONDAY MORNING.
QPF WITH THIS EVENT WILL BE RATHER LOW, AND AGAIN HAVE STAYED ON
THE LOWER END OF SREF ENSEMBLES FOR QPF. TIMING OF THIS EVENT JUST
PRIOR TO DIURNAL HEATING SHOULD AT LEAST PARTIALLY NEGATE MARGINAL
BL TEMPERATURES, LEAVING THE POTENTIAL FOR A LIGHT SNOWFALL
ACCUMULATION (~1") ON GRASSY/ELEVATED SFCS MONDAY MORNING BEFORE
QUICKLY MIXING AND TURNING OVER TO RAIN LATER MONDAY MORNING.
CLEARING COMES QUICKLY BEHIND THE SYSTEM...BY LATE MORN INLAND
INTO THE LATE AFTN COASTAL ZONES. FOR TEMPERATURES, LOOK FOR HIGHS
MONDAY MID/UPPER 40S.
HIGH PRESSURE BUILDS IN FROM THE WEST MONDAY NIGHT AND BECOMES
CENTERED OVER THE MID ATLANTIC TUESDAY BRINGING COOL PLEASANT
CONDITIONS. LOW TEMPERATURES TUESDAY MORNING SHOULD RANGE FROM THE
MID 20S TO LOW 30S...FOLLOWED BY HIGHS IN THE MID 40S EASTERN
SHORE...TO LOW 50S PIEDMONT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL BE CENTERED OVER THE MID ATLANTIC WEDNESDAY
DRIFTING SLOWLY EAST WEDNESDAY NIGHT AND THURSDAY. TEMPERATURES
WILL REBOUND INTO THE LOW TO MID 60S WITH LOWS MODERATING IN THE
LOW TO MID 40S WEDNESDAY NIGHT WITH DEEPENING SOUTHERLY FLOW.
SOUTHERLY FLOW INCREASES THURSDAY AS THE REGION BECOMES SQUEEZED
BETWEEN THE HIGH MOVING OFFSHORE AND THE NEXT APPROACHING STORM
SYSTEM. EVEN WITH SOME INCREASING HIGH CLOUDS THURSDAY
TEMPERATURES WILL WARM INTO THE UPPER 60 TO LOWER 70S.
CHANCES FOR PRECIPITATION WILL HOLD OFF UNTIL LATE FRIDAY OR
SATURDAY. THERE IS MUCH DISAGREEMENT IN THE MODELS REGARDING THE
FORECAST FOR FRIDAY AND SATURDAY. THE ECMWF HAS BEEN MUCH MORE
AMPLIFIED WITH THE NEXT UPPER TROUGH THAN THE GFS AND CANADIAN. IN
RESPONSE THE ECMWF DEVELOPED A SURFACE WAVE OVER THE SOUTHEAST
BRINGING IT INTO THE MID ATLANTIC FRIDAY NIGHT. THE GFS IS WEAKER
AND SLOWER WITH THE SYSTEM HOLDING OFF THE RAIN UNTIL SATURDAY.
THERE WILL BE DISTURBED WEATHER IN THE EXTENDED WITH GOOD CHANCES
FOR PRECIPITATION AT SOME POINT FROM LATE FRIDAY THROUGH SATURDAY.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...LIGHT RAIN WAS OVER MUCH OF THE EASTERN HALF OF THE
CAROLINAS AND WAS REPORTED AT BOTH ORF AND ECG. IN NORTH CAROLINA...
VFR CONDITIONS (ABV 3K FT AND 5 MILES) PREVAIL EXCEPT ALONG THE
IMMEDIATE COAST...EVEN WHERE A FEW HUNDREDTHS OF AN INCH OF RAIN
PER HOUR IS BEING REPORTED. LITTLE CHANGE WAS MADE TO THE EARLIER
TAFS EXCEPT TO ADJUST TIMING OF PCPN SLIGHTLY AND TO RAISE CEILINGS
A BIT. NO IFR IS IN ANY OF THE FORECASTS. ALTHOUGH LIGHT RAIN IS
MENTIONED FOR RIC AND SBY...CONFIDENCE IN THAT OCCURRING AT EITHER
LOCATION IS LOW TO MEDIUM. RAIN ENDS FROM THE WEST LATE SUNDAY
MORNING. CONDITIONS IMPROVE TO VFR SUNDAY AFTERNOON BUT OVERCAST IS
EXPECTED TO REMAIN. WINDS WILL GENERALLY RUN 10 KNOTS OR LESS
THROUGH THE PERIOD.
OUTLOOK...A SHORT WAVE AND ASSOCIATED CLIPPER LOW PRESSURE SYSTEM
WILL AFFECT THE AREA MONDAY MORNING. SOME LIGHT SNOW OR RAIN WILL BE
POSSIBLE...MAINLY ACROSS SRN PORTIONS OF THE AREA. MVFR/IFR
CONDITIONS ARE EXPECTED WITH THE PCPN. ONCE THIS SYSTEM CLEARS THE
COAST LATE MONDAY...EXPECT VFR TO PREVAIL THROUGH THURSDAY.
&&
.MARINE...
SEAS HAVE DROPPED BELOW 5 FEET AND AS A RESULT NO HEADLINES ARE IN
EFFECT. A WEAK NORTHERLY SURGE WILL MOVE THROUGH THE WATERS THIS
MORNING BUT SHOULD STAY BELOW SCA CRITERIA. WINDS INCREASE OUT OF
THE WEST ONCE AGAIN EARLY MONDAY MORNING AND MARGINAL SCA FOR WINDS
AND SEAS ARE POSSIBLE. CONFIDENCE TOO LOW TO ADD SCA AT THIS TIME.
CLIPPER SYSTEM TO MOVE THROUGH THE AREA MONDAY. AS THIS MOVES
OFFSHORE LATE MONDAY...THE SURFACE LOW WILL INTENSIFY. WINDS
INCREASE OUT OF THE NW AND SCA CRITERIA IS LIKELY MONDAY EVENING
THROUGH EARLY TUESDAY ACROSS ALL OF THE WATERS. NO OTHER MARINE
ISSUES APPEAR THROUGH MID WEEK.
&&
.HYDROLOGY...
MINOR FLOODING CONTINUES AT THE WESTHAM GAGE AT RICHMOND. RIVER
LEVELS WILL CONTINUE DROPPING TODAY...BELOW FLOOD STAGE BY EARLY
AFTN. SEE WBCFLSAKQ FOR MORE INFORMATION.
&&
.CLIMATE...
SEE WBCPNSAKQ FOR DETAILS ON METEOROLOGICAL WINTER (DEC-FEB) AT
RICHMOND AND NORFOLK (BOTH BEING 4TH WARMEST ON RECORD).
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
ANZ650-652.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAM/AJZ
LONG TERM...JAO
AVIATION...LSA
MARINE...LSA
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
145 AM EST SUN MAR 4 2012
.SYNOPSIS...
LOW PRESSURE DEVELOPS ALONG A STALLED FRONTAL BOUNDARY AND MOVES UP
THE SOUTHEAST COAST OVERNIGHT...BEFORE MOVING AWAY FROM THE COAST
OFF THE OUTER BANKS SUNDAY MORNING. HIGH PRESSURE BRIEFLY BUILDS
IN SUNDAY AFTERNOON AND SUNDAY NIGHT FOLLOWED BY A QUICK MOVING
LOW PRESSURE SYSTEM...WHICH TRACK ACROSS THE VIRGINIA NORTH
CAROLINA BORDER MONDAY. HIGH PRESSURE RETURNS MONDAY NIGHT AND
TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
INCREASED POPS A BIT MORE ACROSS COASTAL NE NC THIS EVENING AS
RAIN HAS BEGUN TO OVERSPREAD EASTERN NC FAIRLY WELL. FURTHER TO
THE NORTH...DRIER AIR IN THE LOW-LEVELS IS KEEPING RAIN FROM
GETTING ANY FURTHER NORTH SO ONLY HAVE CHC POPS AS FAR NORTH AS
THE VA TIDEWATER THROUGH 06Z. 00Z NAM AND LATEST HRRR STILL
SUPPORT PRECIP EVENTUALLY GETTING FURTHER NORTHEAST OVERNIGHT...WITH
BEST CHANCE EXTENDING FROM THE VA EASTERN SHORE SOUTHWARD THROUGH
THE TIDEWATER AND NE NC SO NO CHANGES NECESSARY TO GOING FORECAST.
LOW TEMPS WILL EVENTUALLY SETTLE INTO THE UPR 30S TO LOW 40S.
PREVIOUS DISCUSSION...
UPPER TROUGH OVER TX WILL CONTINUE TO MOVE EAST AND
SHARPEN ALONG THE GULF COAST TONIGHT. THIS WILL RESULT IN A
BACKING OF THE MID AND UPPER FLOW...WHICH WILL ALLOW MOISTURE TO
SURGE BACK UP THE COAST LATER TONIGHT INTO SUNDAY MORNING. THERE
IS DECENT MODEL AGREEMENT ON AN ELONGATED LOW PRESSURE CENTER
FORMING (AND MOVING NE) OFF THE SOUTHEAST OVERNIGHT...BEFORE
DEPARTING OFF THE OUTER BANKS SUNDAY MORNING. HOWEVER...THERE IS
MORE DISAGREEMENT WITHIN THE MOISTURE FIELDS...BOTH AMOUNTS AND
HOW FAR INLAND RAIN INVADES. AT THIS TIME THE LEAST BULLISH IS THE
ECMWF...WHICH MAKES SENSE GIVEN THE AMOUNT OF CONVECTION FROM THE
FL PANHANDLE TO THE GA COAST. GIVEN THIS...THE HIGHEST POPS
(CATEGORICAL) ARE FORECAST OVER NE NC FROM THE CHOWAN RIVER EAST
AND OVER THE TIDEWATER AND LOWER VA EASTERN SHORE MAINLY LATE
TONIGHT INTO EARLY SUNDAY MORNING...WITH A SHARP DECLINE FROM S
CENTRAL VA TO THE LOWER MD EASTERN SHORE. GENERALLY AN ADDITIONAL
0.3 TO 0.6 IN OF RAIN COULD FALL WHERE CATEGORICAL POPS ARE
FORECAST. WHILE NOT ENOUGH OF A CHANCE TO INCLUDE IN THE FORECAST
GRIDS A FEW ICE PELLETS ARE POSSIBLE ALONG THE NORTHERN FRINGES OF
THE PRECIP AS IT INTERACTS WITH DRIER AIR TO THE WEST.
A FEW RAIN SHOWERS ARE POSSIBLE AS THE UPPER TROUGH AXIS SWINGS
THROUGH SUNDAY AFTERNOON...BUT OTHERWISE A WEST TO EAST IMPROVING
TREND IS EXPECTED. TEMPERATURES WILL BE CHALLENGING ESPECIALLY
DURING THE DAY SUNDAY. READINGS ARE EXPECTED TO STEADILY DROP OFF
OVERNIGHT AND REACH MINIMA FROM THE UPPER 30S NW...TO LOW 40S SE
TOWARD MORNING. AT THIS POINT LOW 50S ARE FORECAST FOR HIGHS WEST OF
I-95 SUNDAY...WITH MID 40S CLOSER TO THE COAST WITH LOW CLOUDS AND
RAIN EXPECTED. OF NOTE...TEMPERATURES ARE MORE REFLECTIVE OF THE MAV
NUMBERS (ALBEIT A FEW DEGREES COOLER) THAN THE NAM-BASED
GUIDANCE...WHICH APPARENTLY OVER-EMPHASIZES DYNAMICAL COOLING ALONG
THE COAST AND TRIES TO MAKE TEMPERATURES COOL ENOUGH TO SUPPORT A
CHANGE-OVER TO SNOW ALONG THE COAST. THAT SOLUTION WAS DISREGARDED
FOR THIS FORECAST.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
THE PATTERN REMAINS ACTIVE EARLY NEXT WEEK AS A VIGOROUS MID-LEVEL
TROUGH DIVES ACROSS THE MIDWEST AND OHIO VALLEY SUNDAY NIGHT. THIS
TROUGH (CLIPPER SYSTEM) CROSSES THE MID ATLANTIC MONDAY...WITH THE
ASSOCIATED SURFACE LOW TRACKING ACROSS THE VA/NC BORDER. THE THERMAL
PROFILE ALOFT CRASHES WITH THIS SYSTEM...1000-500MB THICKNESS VALUES
AROUND 5250M AND LOW-LEVEL THICKNESS VALUES RANGE FROM AROUND 1290M
N...TO 1310 M S. THIS WOULD SUPPORT THE POSSIBILITY OF A PERIOD OF
LIGHT SNOW (GENERALLY IF IT OCCURS EARLY ENOUGH IN THE DAY). AT
THIS POINT THE PRECIP TYPE GENERALLY REFLECTS SREF
PROBABILITIES...AND THE CHANCE OF MEASURABLE LIQUID WAS CAPPED AT 30
PERCENT. CONFIDENCE IS MODERATE ON THE IS SYSTEM AS THE GFS AND
ECMWF HAVE BEEN SOMEWHAT CONSISTENT AND THE NAM HAS SEEMED TO TREND
THIS DIRECTION. NEVERTHELESS...CLIPPER SYSTEMS CAN BE FICKLE. HIGH
TEMPERATURES MONDAY WERE COOLED A FEW DEGREES INTO THE MID/UPPER 40S.
HIGH PRESSURE BUILDS IN FROM THE WEST MONDAY NIGHT AND BECOMES
CENTERED OVER THE MID ATLANTIC TUESDAY BRINGING COOL PLEASANT
CONDITIONS. LOW TEMPERATURES TUESDAY MORNING SHOULD RANGE FROM THE
MID 20S TO LOW 30S...FOLLOWED BY HIGHS IN THE MID 40S EASTERN
SHORE...TO LOW 50S PIEDMONT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL BE CENTERED OVER THE MID ATLANTIC WEDNESDAY
DRIFTING SLOWLY EAST WEDNESDAY NIGHT AND THURSDAY. TEMPERATURES
WILL REBOUND INTO THE LOW TO MID 60S WITH LOWS MODERATING IN THE
LOW TO MID 40S WEDNESDAY NIGHT WITH DEEPENING SOUTHERLY FLOW.
SOUTHERLY FLOW INCREASES THURSDAY AS THE REGION BECOMES SQUEEZED
BETWEEN THE HIGH MOVING OFFSHORE AND THE NEXT APPROACHING STORM
SYSTEM. EVEN WITH SOME INCREASING HIGH CLOUDS THURSDAY
TEMPERATURES WILL WARM INTO THE UPPER 60 TO LOWER 70S.
CHANCES FOR PRECIPITATION WILL HOLD OFF UNTIL LATE FRIDAY OR
SATURDAY. THERE IS MUCH DISAGREEMENT IN THE MODELS REGARDING THE
FORECAST FOR FRIDAY AND SATURDAY. THE ECMWF HAS BEEN MUCH MORE
AMPLIFIED WITH THE NEXT UPPER TROUGH THAN THE GFS AND CANADIAN. IN
RESPONSE THE ECMWF DEVELOPED A SURFACE WAVE OVER THE SOUTHEAST
BRINGING IT INTO THE MID ATLANTIC FRIDAY NIGHT. THE GFS IS WEAKER
AND SLOWER WITH THE SYSTEM HOLDING OFF THE RAIN UNTIL SATURDAY.
THERE WILL BE DISTURBED WEATHER IN THE EXTENDED WITH GOOD CHANCES
FOR PRECIPITATION AT SOME POINT FROM LATE FRIDAY THROUGH SATURDAY.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...LIGHT RAIN WAS OVER MUCH OF THE EASTERN HALF OF THE
CAROLINAS AND WAS REPORTED AT BOTH ORF AND ECG. IN NORTH CAROLINA...
VFR CONDITIONS (ABV 3K FT AND 5 MILES) PREVAIL EXCEPT ALONG THE
IMMEDIATE COAST...EVEN WHERE A FEW HUNDREDTHS OF AN INCH OF RAIN
PER HOUR IS BEING REPORTED. LITTLE CHANGE WAS MADE TO THE EARLIER
TAFS EXCEPT TO ADJUST TIMING OF PCPN SLIGHTLY AND TO RAISE CEILINGS
A BIT. NO IFR IS IN ANY OF THE FORECASTS. ALTHOUGH LIGHT RAIN IS
MENTIONED FOR RIC AND SBY...CONFIDENCE IN THAT OCCURRING AT EITHER
LOCATION IS LOW TO MEDIUM. RAIN ENDS FROM THE WEST LATE SUNDAY
MORNING. CONDITIONS IMPROVE TO VFR SUNDAY AFTERNOON BUT OVERCAST IS
EXPECTED TO REMAIN. WINDS WILL GENERALLY RUN 10 KNOTS OR LESS
THROUGH THE PERIOD.
OUTLOOK...A SHORT WAVE AND ASSOCIATED CLIPPER LOW PRESSURE SYSTEM
WILL AFFECT THE AREA MONDAY MORNING. SOME LIGHT SNOW OR RAIN WILL BE
POSSIBLE...MAINLY ACROSS SRN PORTIONS OF THE AREA. MVFR/IFR
CONDITIONS ARE EXPECTED WITH THE PCPN. ONCE THIS SYSTEM CLEARS THE
COAST LATE MONDAY...EXPECT VFR TO PREVAIL THROUGH THURSDAY.
&&
.MARINE...
HAVE DROPPED THE SCA FOR THE SOUTHERN 3 COASTAL ZONES AS THE OBS
AT BUOY 40099 AND 40100 BOTH SHOW SEAS DOWN TO 4 FT AS THE WINDS
CONTINUE TO RELAX WITH THE STALLED FRONT. HAVE LEFT THE SCA IN
EFFECT FURTHER NORTH AS SEAS AT BUOY 40009 REMAIN AROUND 5 FT. BUT
WITH THE SLACKING OF THE WINDS...EXPECT TO SEE THE SEAS HERE
CONTINUE TO DECREASE.
PREV DISCUSSION... SCA WILL ONLY BE IN EFFECT FOR THE COASTAL
WATERS WITH THE AFTERNOON FORECAST AND MAINLY FOR SEAS OF 4 TO 6
FEET. WINDS HAVE DECREASED TO 15 KT HOWEVER THE CAPE CHARLES BUOYS
AND THE BUOYS OFFSHORE OF DUCK NC ARE REPORTING SEAS OF 5 FEET.
SEAS ARE AROUND 6 FEET FURTHER NORTH. SEAS WILL SLOWLY DECREASE
THIS EVENING AND OVERNIGHT FALLING BELOW SCA.
THE COLD FRONT HAS BEEN SLOW TO PUSH EAST BUT IT WILL REACH THE BAY
AND COASTAL WATERS SHORTLY AFTER SUNSET. WINDS WITH THE FRONT ARE
NOT STRONG AND WILL BECOME NW AROUND 10 TO 15 KT TONIGHT. OVER
THE BAY AND SOUND...WINDS SHOULD DIMINISH OVERNIGHT A FEW HOURS
AFTER THE FRONTAL PASSAGE.
LOW PRESSURE MOVES AWAY FROM THE COAST SUNDAY AS HIGH PRESSURE
BUILDS IN THE FROM THE WEST. THIS WILL KEEP WINDS NW AROUND 15
KT. WINDS BECOME SLY AGAIN SUNDAY NIGHT INTO EARLY MONDAY AS A LOW
PRESSURE SYSTEM MOVES EAST ACROSS THE REGION. WINDS INCREASE ONCE
AGAIN LATE MONDAY BECOMING NW AS THE SURFACE LOW DEEPENS ALONG
THE COAST BEHIND AN UPPER LEVEL SHORT WAVE. SCA MAY BE NEEDED
MONDAY AFTERNOON THROUGH PART OF TUESDAY.
HIGH PRESSURE SETTLES IN FROM THE WEST LATE TUESDAY THROUGH
WEDNESDAY MOVING SLOWLY OFFSHORE THURSDAY. THIS WILL BRING CALMER
CONDITIONS TO THE BAY AND COASTAL WATERS MID WEEK. LOOKING AHEAD
TO THE END OF THE WEEK MODELS ARE IN DISAGREEMENT WITH THE NEXT
STORM SYSTEM WHICH SHOULD IMPACT THE REGION LATE FRIDAY INTO
EARLY SATURDAY WITH POSSIBLE SCA CONDITIONS.
&&
.HYDROLOGY...
MINOR FLOODING IS OCCURRING AT THE WESTHAM GAGE AT RICHMOND.
THE RIVER IS CRESTING THIS AFTERNOON ONE FOOT ABOVE FLOOD STAGE
AND WILL REMAIN IN MINOR FLOOD THROUGH SUNDAY MORNING.
&&
.CLIMATE...
SEE WBCPNSAKQ FOR DETAILS ON METEOROLOGICAL WINTER (DEC-FEB) AT
RICHMOND AND NORFOLK (BOTH BEING 4TH WARMEST ON RECORD).
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
ANZ650-652.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ/JDM
SHORT TERM...AJZ
LONG TERM...JAO
AVIATION...LSA
MARINE...ESS/JAO
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
NWS DULUTH MN
301 AM CST SUN MAR 4 2012
.SHORT TERM...
TODAY THROUGH MONDAY AFTERNOON...
LAKE EFFECT SNOW SHOWERS ALONG THE NORTH SHORE TODAY FROM DULUTH
TO SILVER BAY WILL BE THE MAIN FOCUS IN THE SHORT TERM. A LAKE
EFFECT SNOW ADVISORY IS IN EFFECT UNTIL 4 PM THIS AFTERNOON FOR
THIS AREA.
A BROAD UPPER TROUGH IS POSITIONED OVER THE ERN CONUS WITH AN
UPPER RIDGE BUILDING IN ACROSS THE WEST COAST. AT THE SFC AN
INVERTED TROUGH REMAINS DRAPED ACROSS THE GREAT LAKES...EXTENDING
FROM LAKE ONTARIO THROUGH MICHIGAN AND BACK INTO WRN LAKE
SUPERIOR. A SFC HIGH IS SITUATED OVER NRN ONTARIO WITH A SECOND
NARROW SFC HIGH CUTTING THROUGH THE RED RIVER VALLEY AS THE NEXT
SYSTEM PREPARES TO MOVE THROUGH SRN MN FROM THE NRN ROCKIES. THE
EXTENSION OF THIS INVERTED TROUGH INTO THE NORTHLAND ALONG WITH
THE COMBINATION OF A PERSISTENT ELY FLOW FROM THE SFC HIGH TO THE
NORTH AND COLD AIR ALOFT HAS ALLOWED THE LOCALIZED LAKE
EFFECT SNOW SHOWERS TO CONTINUE THROUGH THE LAST 24-36 HOURS.
ATTM...IT APPEARS THIS SET UP WILL PERSIST THROUGH THIS MORNING
AND INTO THE MID AFTERNOON TODAY BEFORE THE WINDS SHIFT TO THE
WEST AND CUT OFF THE LES PROCESSES. LATEST NAM12 AND RUC13 BOTH
INDICATE THE LOW LEVEL E/NE WINDS...STEEP 0-3KM LAPSE
RATES...SATURATED BL AND 1000-900MB CONVERGENT CONDITIONS WILL
PERSIST THROUGH THE REST OF THE MORNING UNTIL AROUND 21/22Z. A
FAIRLY INTENSE LINE OF REGENERATIVE LE SNOW SHOWERS HAVE BEEN
INDICATED ON THE DLH RADAR FOR THE PAST 4-5 HOURS MAINLY
AROUND TWO HARBORS...AND IT APPEARS WILL CONTINUE FOR QUITE SOME
TIME. THERE IS SOME QUESTION AS TO WHETHER THIS BAND COULD VEER TO
THE NORTH TO AROUND SILVER BAY...OR TO THE SOUTH TO DULUTH...OR
EVEN IF ADDITIONAL SNOW BANDS COULD DEVELOP THROUGH THE HEAD OF
THE LAKE. GIVEN THE LATEST RADAR TRENDS AND FAVORABLE CONDITIONS
FOR LES TO PERSIST...WILL ISSUE A LAKE EFFECT SNOW ADVISORY FOR
SOUTHEAST ST. LOUIS COUNTY AND SOUTHERN LAKE COUNTY ALONG THE LAKE
SHORE UNTIL 4 PM. WILL LIKELY SEE 3 TO 5 INCHES IN THIS
AREA...WITH LOCALLY HIGHER AMOUNTS IN LOCATIONS THAT SEE A
PERSISTENT MDT/HVY SNOW BAND THIS MORNING. THE AREA AROUND TWO
HARBORS IS THE MOST LIKELY LOCATION FOR THE HEAVIEST SNOW. EVEN
THOUGH CARLTON COUNTY AND PARTS OF WEST DULUTH/HERMANTOWN ARE IN
THE ADVISORY...A GOOD PORTION OF THIS ZONE WILL ONLY SEE 1-2
INCHES AT MOST. THE MAIN AREA WE ARE CONCENTRATING ON IS FROM THE
NE SECTIONS OF DULUTH NEWD ALONG THE SHORE TO AROUND SLIVER BAY.
COULD SEE A FEW LIGHT SHOW SHOWERS LINGER OVER THE ARROWHEAD AND
NW WI TONIGHT...BUT WITH ONLY LIGHT ADDITIONAL ACCUMULATIONS
EXPECTED. THE SFC RIDGE AXIS SLIDES QUICKLY THROUGH THE REGION
TOMORROW AND ALLOWS CONDITIONS TO DRY OUT...SKIES TO CLEAR OFF
PARTIALLY AND TEMPERATURES TO WARM WELL INTO THE 30S.
THE NEXT WEAK SYSTEM SLIDES ACROSS THE NORTH LATE TOMORROW
AFTERNOON AND BRINGS ANOTHER CHANCE OF SNOW SHOWERS TO THE
BORDERLAND FROM INTL FALLS TO VIRGINIA TO GRAND MARAIS. ONLY LIGHT
ACCUMULATIONS ARE EXPECTED.
.LONG TERM...
MONDAY NIGHT THROUGH SATURDAY...
THE MODELS ARE IN BETTER AGREEMENT THROUGH MUCH OF THE PERIOD.
WARM AIR WILL BE IN PLACE EARLY IN THE PERIOD. SOME LIGHT PRECIP
WILL BE POSSIBLE MONDAY NIGHT ACROSS THE FAR NORTH...WHICH WOULD
LIKELY FALL AS A LIGHT MIX. PERSISTENT WAA AND STRENGTHENING
INVERSION COULD LEAD TO BOTH SOME DRIZZLE AND MORE CLOUD COVER
THAN WE CURRENTLY HAVE IN THE GRIDS. AT THIS TIME...WE`LL KEEP
TUESDAY DRY AND CLOUD COVER AS PARTLY CLOUDY. A COLD FRONT WILL
MOVE THE NORTHLAND TUESDAY NIGHT INTO WEDNESDAY...WITH A CHANCE
FOR PRECIP BOTH AHEAD AND BEHIND THE BOUNDARY. WE ADDED A SLIGHT
CHANCE FOR LIGHT RAIN TUESDAY EVENING WITH 35-45KT SOUTHWEST WINDS
AT 850MB FORECAST. RAIN SHOULD BE THE MAIN PRECIP TYPE AHEAD OF
THE FRONT WITH WARM 850MB TEMPS FORECAST...TRANSITIONING TO MAINLY
SNOW WELL BEHIND THE FRONT. PRECIP AMOUNTS SHOULD BE LIGHT.
GFS/ECMWF DIFFER SOME ON THURSDAY WITH HOW FAR SOUTH THEY BRING A
SHORTWAVE TROUGH AND SURFACE LOW PRESSURE. WE WENT CLOSER TO THE
ECMWF AND HAVE A CHANCE FOR LIGHT SNOW. AGAIN WITH THIS
SYSTEM...PRECIP AMOUNTS LOOK LIGHT...WITH THE EXCEPTION OF
THURSDAY NIGHT/FRIDAY ALONG THE SOUTH SHORE WHICH COULD SEE SOME
BETTER SNOW ACCUMULATIONS DUE TO LAKE EFFECT PROCESSES.
NEXT WEEKEND LOOKS DRY WITH A SIGNIFICANT WARM UP FORECAST BY
BOTH THE GFS/ECMWF.
&&
.AVIATION...06Z TAF ISSUANCE...
SNOW SHOWERS WILL CONTINUE ACROSS MUCH OF THE NORTHLAND
OVERNIGHT. THE MOST SUBSTANTIAL SNOWFALL WILL BE IN THE KDLH
AREA...AS EASTERLY WINDS OFF LAKE SUPERIOR CONTINUE TO BRING SNOW
SHOWERS. SKY COVER WILL VARY WIDELY...FROM VFR TO IFR AND EVEN
LIFR IN THE STRONGEST SNOW SHOWERS. AWAY FROM LAKE SUPERIOR
CONDITIONS WILL GENERALLY BE VFR TO MVFR. THE SNOW SHOWERS WILL
CONTINUE INTO SUNDAY AND SUNDAY EVENING...ESPECIALLY NEAR THE
LAKE.
&&
.POINT TEMPS/POPS...
DLH 25 9 33 27 / 60 30 10 10
INL 24 5 35 29 / 20 10 40 20
BRD 28 11 37 29 / 30 10 10 10
HYR 28 7 35 27 / 30 20 10 10
ASX 26 10 35 28 / 40 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...LAKE EFFECT SNOW ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR
MNZ020-037.
WI...NONE.
&&
$$
SHORT TERM...TENTINGER
LONG TERM....MELDE
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
349 AM CST SUN MAR 4 2012
.DISCUSSION...
FORECAST CHALLENGE OVER THE NEXT 48 HOURS DEALS WITH ADVISORY
CRITERIA WIND SPEEDS THIS AFTERNOON...THEN THE FOCUS SHIFTS TO THE
EXPECTED WARM UP FOR THE BEGINNING OF THE WORK WEEK AND ASSOCIATED
FIRE RISKS.
INHERITED WIND ADVISORY LOOKS TO BE IN GOOD SHAPE...WITH ONLY A FEW
MINOR MODIFICATIONS NEEDED AT THIS POINT IN TIME. WILL GO AHEAD AND
BEGIN THE WIND ADVISORY FOR OUR WESTERN COUNTIES WITH THIS FORECAST
ISSUANCE...AS CRITERIA LEVEL WIND SPEEDS HAVE ALREADY BEEN REPORTED
ACROSS THE WESTERN PANHANDLE EARLY THIS MORNING. WILL ALSO INCLUDE
WESTERN CHERRY AND SHERIDAN COUNTY IN THE ADVISORY AS RECENT HRRR
MODEL OUTPUT SUGGESTS THE POTENTIAL THERE FOR ADVISORY LEVEL WIND
GUSTS. OTHERWISE MODELS CONTINUE TO INDICATE STRONG UNIDIRECTIONAL
FLOW WITH DEEP MIXING THROUGH EARLY-TO-MID AFTERNOON TODAY. WITH
MIXING POTENTIAL AOA 800MB...MOMENTUM TRANSFER OF UP TO 60 KTS IS
POSSIBLE...WHICH WOULD LEAD TO SURFACE WIND GUSTS OF GREATER THAN 45
MPH EARLY THIS AFTERNOON ACROSS MUCH OF THE CWA. BY MID AFTERNOON
THE STRONGEST HEIGHT RISES AND MOMENTUM ALOFT WILL BE NORTH AND EAST
OF FORECAST AREA. THUS EXPECT WIND SPEEDS TO SUBSIDE RATHER QUICKLY
LATER THIS AFTERNOON...SUCH THAT THE ONGOING WIND ADVISORY MAY BE
CANCELED A FEW HOURS EARLY. BUT FOR NOW...WILL CONTINUE THE ONGOING
ADVISORY UNTIL 00Z TONIGHT.
NOT SURE WHAT TO MAKE OF THE CLIPPER TYPE SYSTEM CURRENTLY BRUSHING
OUR NORTHERN AND EASTERN ZONES. -SN HAS BEEN REPORTED AT BOTH KVTN
AND KANW EARLY THIS MORNING...HOWEVER SATURATION ELSEWHERE HAS BEEN
SLOW TO COMMENCE. THE HRRR CONTINUES TO PAINT LIGHT QPF ACROSS OUR
NORTHERN AND WESTERN ZONES THROUGH MID MORNING...NAM IS A BIT MORE
OPTIMISTIC AND DRIER. THE EURO AND TO SOME EXTENT THE GFS SEEM TO
WANT TO GENERATE LIGHT QPF ACROSS OUR WESTERN ZONES LATE THIS
MORNING. WITH THE STEEP LAPSE RATES...WEAK INSTABILITY AND FAVORABLE
UPPER LEVEL DYNAMICS IN PLACE...CANNOT ARGUE AGAINST THE POTENTIAL
OF A -SNSH OR -RASH THROUGH MID MORNING. HOWEVER SOUNDINGS INDICATE
MINIMAL LOW LEVEL MOISTURE AND THE FACT THAT CURRENT RADAR
OBSERVATIONS SUGGEST OTHERWISE...WILL LEAN TOWARD THE THE DRIER
SOLUTIONS...MAINLY THE NAM AND END THE MENTION OF PRECIPITATION
SHORTLY AFTER 15Z THIS MORNING. REVISIONS MAY BE NEEDED.
THE THREAT OF HEIGHTENED FIRE DANGER IS STILL A POSSIBILITY TODAY
ACROSS FAR SOUTHWESTERN PORTIONS OF THE CWA...HOWEVER RELATIVE
HUMIDITY VALUES ARE LOOKING SLIGHTLY BETTER THAN COMPARED WITH
PREVIOUS MODEL RUNS. LOW TO MID LEVEL MOISTURE HAS INCREASED
SLIGHTLY...AND EVEN WITH THE WARMER EXPECTED TEMPERATURES THIS
AFTERNOON...STILL LOOKING FOR MINIMUM RELATIVE HUMIDITY VALUES SOME
10 PERCENT OR GREATER ABOVE RED FLAG CRITERIA. AS OF NOW...FIRE
ZONES 210...219...AND FAR SOUTHWESTERN PORTIONS OF 204 HAVE THE
HIGHEST POTENTIAL OF EXTREME FIRE BEHAVIOR...BUT AGAIN NOT ENOUGH TO
WARRANT ANY FIRE HEADLINES. MONDAY AND ESPECIALLY TUESDAY MAY BE A
DIFFERENT STORY HOWEVER.
FOR THE START OF THE WORK WEEK...A FLAT UPPER LEVEL RIDGE WILL BUILD
ACROSS THE NORTHERN AND CENTRAL PLAINS LATE SUNDAY INTO MONDAY AND
USHER IN STRONG WARM AIR ADVECTION. MODEL GUIDANCE HINTS AT H925
TEMPERATURES ACROSS SOUTHWEST NEBRASKA AOA 15C BY MONDAY AFTERNOON.
FIRE CONCERNS MAY BE POSSIBLE ONCE AGAIN AS RELATIVE HUMIDITY VALUES
APPROACH CRITICAL LEVELS. GENERALLY TRENDED TOWARD THE DRIER ECMWF
GUIDANCE AS THE MODEL HAS PERFORMED REASONABLY WELL THE PAST COUPLE
DAYS WITH THE HANDLING OF THE RELATIVE HUMIDITY FIELDS. NOW ON
MONDAY AFTERNOON SOUTHERLY RETURN FLOW WILL STRENGTHEN AHEAD OF A
DEEPENING HIGH PLAINS SURFACE TROUGH. GENERALLY EMPLOYED THE USE OF
A GUIDANCE BLEND FOR WIND SPEEDS. THIS BLEND WOULD SUGGEST WIND
GUSTS OF LESS THAN 25 MPH /BELOW RED FLAG CRITERIA/.
H85 THERMAL RIDGE SHOULD BE MAXIMIZED ACROSS NORTH CENTRAL NEBRASKA
ON TUESDAY...WITH H85 TEMPERATURES WELL ABOVE 15C ACROSS MUCH OF THE
FORECAST AREA. THIS SHOULD TRANSLATE TO MAXIMUM HIGHS INTO THE MID
TO UPPER 60S ACROSS THE ENTIRE FORECAST AREA...WITH POSSIBLY LOW TO
MID 70S OVER THE HEAT PRONE AREAS OF THE CWA. AGAIN SOUTHERLY
RETURN FLOW LOOKS TO BECOME ESTABLISHED AS LOW PRESSURE DEEPENS IN
RESPONSE TO A DIGGING GREAT BASIN TROUGH. WITH EXPECTED HIGH
TEMPERATURES WELL ABOVE 70 DEGREES FAHRENHEIT ACROSS SOUTHWEST
NEBRASKA...FIRE ZONES 204...210...219 AND POSSIBLY SOUTHERN PORTIONS
OF 206 MAY EXPERIENCE RED FLAG CONDITIONS AS RH VALUES WILL FALL
BELOW 15 PERCENT AND WIND GUSTS WILL FLIRT WITH 25 MPH. A FIRE
WEATHER WATCH AND RED FLAG WARNINGS MAY BE NEEDED FOR TUESDAY.
CHANGES ARE IN STORE THEREAFTER AS A WEST COAST UPPER TROUGH
ADVANCES ON THE NORTHERN AND CENTRAL PLAINS. THE LONG RANGE
SOLUTIONS ALL AGREE THAT A STRONG COLD FRONT WILL ACCOMPANY THE
TROUGH AND BRING AN END TO THE PLEASANT WEATHER CONDITIONS. BY
MIDDAY WEDNESDAY...H85 TEMPERATURES APPEAR TO RUN SOME 15 TO 20C
COOLER THAN THAT TO BE OBSERVED ON TUESDAY. PRECIPITATION CHANCES
ARE BECOMING LESS CERTAIN MID WEEK AS THE TROUGH CONTINUES TO TREND
SOUTH. THE CONSENSUS AND ENSEMBLES CONTINUE TO SUPPORT A SPLIT
PATTERN WHICH WOULD FAVOR A DRY FORECAST FOR MUCH OF THE CWA AS THE
SYSTEM MEANDERS ACROSS THE SOUTHWEST. THE EXTENDED PROCEDURE
GENERALLY CUT BACK POPS ON WEDNESDAY...WHICH LOOKS PLAUSIBLE AT THIS
POINT IN TIME...THUS NO MAJOR CHANGES WERE MADE. OTHERWISE WITH A
SPLIT FLOW REGIME THAT TRANSITIONS TO GENERAL RIDGING ALOFT BY WEEKS
END...A DRY FORECAST WITH NEAR TO SLIGHTLY ABOVE AVERAGE
TEMPERATURES APPEAR REASONABLE AT THIS POINT IN TIME FOR THE
EXTENDED.
&&
.AVIATION...
VFR IS GENERALLY EXPECTED ALL AREAS TODAY AND TONIGHT.
LOCAL MVFR CONDITIONS IN ISOLD SHRA/SHSN WILL CONTINUE THROUGH 00Z
TODAY AS A WARM FRONT MOVES EAST THROUGH NCNTL NEB AND IS REPLACED
BY A COLD FRONT MOVING THROUGH LATER THIS MORNING.
WINDS TODAY INCREASE TO 33030G45 IN MANY AREAS AS A STRONG LOW
PRESSURE SYSTEM ACROSS WRN ND THIS MORNING DIVES SOUTH THROUGH THE
MISSOURI RIVER BASIN THROUGHOUT THE DAY. WINDS SUBSIDE BY 01Z THIS
EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 5 PM MST THIS
AFTERNOON FOR NEZ004-022-023-035-056>058-069-094.
WIND ADVISORY FROM 8 AM CST /7 AM MST/ THIS MORNING TO 6 PM CST
/5 PM MST/ THIS EVENING FOR NEZ005>010-024>029-036>038-059-070-
071.
&&
$$
SHORT TERM/EXTENDED...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
926 AM EST SUN MAR 4 2012
.SYNOPSIS...
AN AREA OF LOW PRESSURE IS FORECAST TO TRACK WELL TO OUR SOUTH AND
EAST TODAY, THEN A WEAK SYSTEM QUICKLY TRACKS ACROSS PARTS OF THE
MID ATLANTIC MONDAY BEFORE GOING OUT TO SEA. A LARGE AREA OF HIGH
PRESSURE BUILDS ACROSS OUR AREA TUESDAY BEFORE SHIFTING TO OUR
EAST WEDNESDAY. A SLOW MOVING COLD FRONT IS FORECAST TO APPROACH
OUR REGION LATE THURSDAY, THEN GRADUALLY SETTLE THROUGH OUR AREA
FRIDAY. HIGH PRESSURE SHOULD BEGIN TO BUILD TOWARD OUR AREA DURING
SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO BIG CHANGES TO THE SHORT TERM GRIDS. PRECIPITATION CONTINUES TO
GRAZE THE SERN PART OF OUR CWA. AS PER THE LATEST HRRR THIS SHOULD
BE THE CASE DURING THE NEXT COUPLE OF HOURS. WE SLOWED THE ASCENT
OF TEMPS A BIT IN THE NEAR TERM.
THE MAIN FORECAST PROBLEM FOR TODAY WILL BE THE NORTHWEST EXTENT OF
THE PRECIPITATION SHIELD ASSOCIATED WITH THE SURFACE LOW PASSING
SOUTHEAST OF THE AREA.
A LARGE SWATH OF CIRRUS AND ALTOSTRATUS COVERS THE AREA THIS
MORNING...AS SEVERAL VERY STRONG JET STREAKS (SOME IN EXCESS OF
150 KNOTS) STREAM NORTHEAST THROUGH THE UPPER LEVEL FLOW. A SHORT
WAVE ASSOCIATED WITH ONE OF THE JET STREAKS IS APPROACHING THE
STALLED FRONT ALONG THE NORTH CAROLINA COAST. AS THE SHORT WAVE
APPROACHES...IT IS INDUCING A LARGE AREA OF MID LEVEL
FRONTOGENETIC FORCING ALONG THE BAROCLINIC ZONE ASSOCIATED WITH
THE SURFACE FRONT.
IN TURN...THE RADAR RETURNS ARE BLOSSOMING JUST SOUTH OF THE BEST
MID LEVEL FRONTOGENETIC FORCING. THE RAIN SHIELD HAS MADE IT INTO
SOUTHEAST VIRGINIA EARLY THIS MORNING. THE PROGRESSION HAS BEEN
SLOWED BY THE VERY DRY AIRMASS IN PLACE AHEAD OF THE MID LEVEL
FORCING (THE KWAL AND KIAD 0000 UTC SOUNDINGS WERE VERY DRY). THE
DRY AIR WILL PLAY AN IMPORTANT ROLE IN DETERMINING JUST HOW FAR
NORTH AND WEST THE RAIN SHIELD GETS.
THE MODEL CONSENSUS IS TO KEEP THE MAIN RAIN SHIELD CONFINED TO
SOUTHEAST DELAWARE AND A PORTION OF THE SOUTHEAST NEW JERSEY COAST
THIS MORNING (AND PERHAPS EARLY AFTERNOON). THIS MAKES SENSE
CONSIDERING THAT THE MID LEVEL FLOW DOES NOT LOOK AS THOUGH IT WILL
BACK ENOUGH TO ALLOW THE MID LEVEL FORCING TO GET ANY FURTHER WEST.
ADD IN THE FACT THAT THE AIRMASS IS VERY DRY IN PLACE...AND IT WOULD
APPEAR AS THOUGH THE ABOVE MENTIONED AREAS WILL BE THE ONLY ONES
TO GET ANY MEASURABLE PRECIPITATION FROM THIS SYSTEM.
THE COLUMN IS DRY (AND DRY EQUALS COLD THIS TIME OF YEAR).
HOWEVER...IT DOES NOT APPEAR AS THOUGH THE PRECIPITATION RATES WILL
BE HIGH ENOUGH TO TAKE FULL ADVANTAGE OF THE EVAPORATIVE COOLING
POTENTIAL . ADD IN THE FACT THAT DEW POINTS ARE RELATIVELY
HIGH...AND IT APPEAR AS THOUGH RAIN WILL BE THE PRECIPITATION TYPE
TODAY.
ELSEWHERE...THE HIGH AND MID LEVEL CLOUDS SHOULD AFFECT THE REGION
FOR MUCH OF THE DAY. THERE IS SOME HINT THAT MOST PLACES GET CLOSE
TO CONVECTIVE TEMPERATURES...WHICH WOULD ALLOW LOWER CLOUDS TO FILL
IN WHERE THERE IS SUNSHINE. BASED ON THIS...HIGHS WERE NUDGED DOWN
CLOSER TO THE COOLER NAM MOS NUMBERS.
MODEL SOUNDINGS ARE SUGGESTING THAT AS A COLD FRONT APPROACHES FROM
THE WEST...THE INCREASE IN THE DEPTH OF THE MIXED LAYER COULD RESULT
IN GUSTINESS TO THE WIND THIS AFTERNOON. IN FACT...MODEL SOUNDINGS
ARE SHOWING 35 KNOTS AT THE TOP OF THE INVERSION...WHICH COULD
TRANSLATE INTO 30 MPH WIND GUSTS. NOT SURE HOW MUCH OF THIS WE WILL
ACTUALLY SEE...SINCE THE MIXING COULD AFFECTED BY THE HIGH AND MID
LEVEL CLOUDS...WHICH WILL IN TURN LIMIT HEATING. GUSTINESS WAS
RETAINED FOR THE FORECAST.
FINALLY...AS A NORTHERN STREAM SHORT WAVE APPROACHES FROM THE WEST
LATE THIS AFTERNOON AND THIS EVENING...IT COULD PRODUCE SOME SNOW
SHOWERS IN THE HIGHER TERRAIN. FOR NOW...THE BETTER POTENTIAL LOOKS
TO WAIT UNTIL LATER THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE ABOVE MENTIONED SHORT WAVE SHOULD PASS NORTH OF THE THE AREA
THIS EVENING. NEAR TERM MODEL SHOW SNOW SHOWERS WITH THE SHORT
WAVE (AND THE ITS ASSOCIATED COLD FRONT) ACROSS THE HIGHER TERRAIN
THIS EVENING...THEN PERHAPS SOME LAKE CONTRIBUTION OR UPSLOPE
LATER THIS EVENING. IN EITHER CASE...A CHANCE OF SNOW SHOWERS WILL
BE RETAINED FOR THIS EVENING.
ELSEWHERE...THE LOWER CLOUDS SHOULD ERODE...AND THE MID CLOUDS
SHOULD FOLLOW SHORTLY THEREAFTER. MODEL SOUNDINGS SHOW SOME GUST
POTENTIAL THIS EVENING BEHIND THE COLD FRONT...SO MOST PLACES
PROBABLY RETAIN SOME WIND MOST OF THE NIGHT. ANY EVENING CLEARING
SHOULD BE FOLLOWED BY SOME HIGH CLOUDS LATER TONIGHT (ESPECIALLY
ACROSS THE SOUTH) AHEAD OF YET ANOTHER SYSTEM IN THE NORTHERN
STREAM.
LOWS WERE BASED MAINLY ON THE WARMER GFS MOS NUMBERS. THE TRANSITION
OF CLOUDINESS...AS WELL AS SOME GRADIENT...SUGGEST LIMITED
RADIATIONAL COOLING POTENTIAL OUTSIDE OF PROTECTED LOCATIONS.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
FAIRLY QUICK PATTERN SHIFTS WILL OCCUR DURING THIS TIME FRAME WITH
THE POTENTIAL FOR A COUPLE OF RATHER WARM DAYS AFTER A COOL DOWN.
WE START THOUGH WITH A TROUGH IN THE EAST MONDAY, WHICH WILL AMPLIFY
A BIT. THE PATTERN IS FAIRLY FAST THOUGH AS A TROUGH IN THE WEST
WILL ALLOW DOWNSTREAM RIDGING TO BUILD AND PUSH EASTWARD. THIS WILL
ALLOW MUCH MILDER AIR TO SURGE INTO THE REGION UNDER A SOUTHWEST
FLOW AS HIGH PRESSURE BECOMES SITUATED OFF THE MID ATLANTIC COAST. A
FAIRLY SHARP COLD FRONT HOWEVER WILL ARRIVE FRIDAY TO PROVIDE A
CHANGE BACK TO COOLER CONDITIONS.
A CLIPPER TYPE SYSTEM IS STILL FORECAST TO TRACK SOUTH OF OUR REGION
DURING MONDAY. THE GFS AND NAM/WRF APPEAR TO BE ON THE STRONGER SIDE
WITH THE ECMWF WEAKER. THE GFS AND NAM/WRF SEEM TO HAVE MORE OF A
CONVECTIVE LOOK, WHICH MAY BE A REASON WHY THE SOLUTIONS ARE
STRONGER. THE MOISTURE IS GENERALLY LIMITED WITH THIS SYSTEM, AND
WHILE A RIBBON OF 850 MB TO 700 MB FRONTOGENETIC FORCING SLIDES
ACROSS THE DELMARVA, THE LOWER LEVELS MAY BE DRY ENOUGH TO ERODE ANY
PRECIPITATION ON THE NORTHERN EDGE. THE FORECAST SOUNDINGS DO SHOW
STEEPER LOWER LEVEL LAPSE RATES, BUT ALSO NO TOTAL SATURATION IN THE
LOWER LEVELS. THE PRECIPITATION TYPE LOOKS TO BE SNOW BASED ON THE
SOUNDINGS, ALTHOUGH PERHAPS JUST ENOUGH BOUNDARY LAYER WARMTH TO
ALLOW FOR SOME RAIN OR A MIX OF RAIN AND SNOW. THE PRECIPITATION
SHOULD BE LIGHT, IF IT EVEN GETS THIS FAR NORTH AS THE MAIN LIFT
MIGHT END UP GOING INTO CLOUD PRODUCTION VERSUS ACTUAL
PRECIPITATION. THE SREF PROBABILITY OF GREATER THAN 0.01 OF AN INCH
IS 30 PERCENT OR LESS ACROSS SOUTHERN DELAWARE AND THE VERY NEARBY
AREAS. THE 00Z ECMWF IS SIMILAR WITH ITS WEAKER SURFACE REFLECTION,
AND THE 850 MB TO 700 MB FRONTOGENETIC FORCING BARELY CLIPS SOUTHERN
DELAWARE. SINCE THE CHC OF A LITTLE LIGHT QPF SLIDING ACROSS
PORTIONS OF THE DELMARVA MONDAY IS ON THE RATHER LOW SIDE, WE JUST
HELD ONTO A SMALL AREA OF SLIGHT CHC TO LOW CHC POPS. THIS SYSTEM IS
FORECAST TO MOVE OUT TO SEA MONDAY NIGHT WITH A PRESSURE GRADIENT
TIGHTENING UP IN ITS WAKE. THERE IS A STRONG AREA OF CHANNELIZED
VORTICITY TO SLIDE ACROSS THE AREA, HOWEVER GIVEN DRIER AIR
ADVECTING INTO THE AREA, PERHAPS JUST SOME CLOUDS MAY RESULT.
HIGH PRESSURE IS FORECAST TO SETTLE IN DURING TUESDAY WITH THE FLOW
BACKING TO THE WEST AND EVENTUALLY SOUTHWEST. THE AIRMASS IS
FORECAST TO BE MODERATING ALOFT, HOWEVER GIVEN LESS MIXING
ANTICIPATED TUESDAY MAY BE THE COOLEST AFTERNOON. WE MAY GET DECENT
RADIATIONAL COOLING TUESDAY NIGHT AS THE SURFACE HIGH GRADUALLY
SHIFTS TO OUR EAST AND THE BOUNDARY LAYER REMAINS DECOUPLED IN
CONJUNCTION WITH A DRY LOW-LEVEL AIRMASS.
FOR WEDNESDAY, A CHILLY START THEN A MODERATING TREND WILL OCCUR
AS WAA IS UNDERWAY COURTESY OF A RETURN FLOW AND MID LEVEL RIDGING.
GIVEN THE WAA ALOFT AND THE OVERALL WIND FIELD STRENGTHENING
WEDNESDAY NIGHT INTO THURSDAY, SOME FORECAST SOUNDINGS INDICATE THAT
THE LOW-LEVEL MOISTURE MAY INCREASE ENOUGH UNDER AN INVERSION TO
PERHAPS DEVELOP SOME LOWER CLOUDS. THE LOW-LEVEL MIXING SHOULD WANE
GIVEN A MORE STABLE LOW-LEVEL ENVIRONMENT, HOWEVER THIS WILL ALL
HAVE A POTENTIAL IMPACT ON TEMPERATURES. ATTM, WE HAVE LOWER
CONFIDENCE REGARDING THE EXTENT OF ANY LOW CLOUDS DEVELOPING
WEDNESDAY NIGHT INTO THURSDAY. DURING THURSDAY, ANY INVERSION SHOULD
MIX OUT AS THE BOUNDARY LAYER WARMS AND MIXING IS ABLE TO DEEPEN.
GIVEN A DEEP SOUTHWESTERLY FLOW AND SOME ADDITIONAL WARMING ALOFT,
TEMPERATURES COULD END UP BEING WARMER THAN CURRENTLY FORECAST.
GIVEN SOME UNCERTAINTY ON WHETHER THURSDAY WILL START WITH SOME
LOWER CLOUDS, WE DID NOT WANT TO RAISE TEMPERATURES MUCH FROM
CONTINUITY.
THE NEXT UPPER-LEVEL TROUGH WILL BE SWINGING TOWARD THE REGION LATE
THURSDAY INTO FRIDAY. GIVEN THE FORECAST RIDGE TO OUR EAST, THIS
TROUGH AND ASSOCIATED COLD FRONT SHOULD SLOWLY APPROACH. THERE IS A
FAIRLY DECENT THERMAL GRADIENT FORECAST WITH THIS FRONT, AND GIVEN A
STRONG SOUTHWEST FLOW AHEAD OF IT, A PLUME OF MOISTURE SHOULD ADVECT
NORTHWARD. SOME MODEL GUIDANCE IS MORE ROBUST WITH THE QPF THAN
OTHERS, BUT IT DOES APPEAR THAT AT LEAST A BAND OF SHOWERS ARRIVES
WITH THE FRONT THURSDAY NIGHT AND FRIDAY. THIS FRONT SHOULD THEN BE
EAST OF OUR AREA SATURDAY AS HIGH PRESSURE STARTS TO BUILD IN FROM
THE WEST. THERE IS LOWER CONFIDENCE THOUGH REGARDING THE FORECAST
TEMPERATURES AND SENSIBLE WEATHER FOR FRIDAY INTO SATURDAY DUE TO
THE SLOWNESS OF THE FRONT. GIVEN THE SLOWER MOVEMENT, THERE COULD BE
A BETTER POTENTIAL FOR ENERGY TO DEVELOP ALONG THE TAIL END OF THE
FRONT WHICH WOULD THEN TRACK NORTHEASTWARD. IT DOES APPEAR THAT
TEMPERATURES WILL BE TURNING COOLER SATURDAY AS THE UPPER TROUGH
SWINGS THROUGH ALONG WITH A NORTHERLY WIND.
OVERALL, WE DID NOT MAKE ANY SIGNIFICANT CHANGES TO CONTINUITY.
TEMPERATURES MONDAY AND TUESDAY WERE MORE OF A MOS BLEND, THEN WE
LEANED MORE TOWARD CONTINUITY WITH A BIT OF A BLENDING IN OF THE
MOSGUIDE.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS CONTINUE ACROSS THE AREA THIS MORNING...WITH
MAINLY HIGH AND MID LEVEL CLOUDINESS. THE GRADIENT IS STILL IN
PLACE...BUT THIS SHOULD BACK OFF AS A SURFACE FRONT STALLS TO THE
SOUTHEAST.
LOW PRESSURE IS ORGANIZING ON THE FRONT NEAR THE NORTH CAROLINA
COAST. THE LOW SHOULD REMAIN FAR ENOUGH SOUTH AND EAST OF THE AREA
TO KEEP THE PRECIPITATION SHIELD OUT OF THE AREA. AS THE LOW DEEPENS
LATE THIS MORNING...THE TIGHTENING GRADIENT SHOULD RESULT IN WEST TO
NORTHWEST WINDS BECOMING GUSTY. MODEL SOUNDINGS SHOW THE POTENTIAL
FOR GUST TO 25 KNOTS BETWEEN 1700 AND 2300 UTC.
VFR CEILINGS WILL LOWER THIS AFTERNOON TO ABOUT 5000 FEET...AND THIS
LAYER WILL REMAIN PLACE INTO THIS EVENING. THE LOWER CLOUDS SHOULD
ERODE THIS EVENING...WITH MID AND HIGH CLOUDINESS ABOVE THAT. THE
GUSTY WINDS WILL DIMINISH AFTER 0000 UTC...WITH VFR CONDITIONS
EXPECTED THROUGH 1200 UTC MONDAY.
OUTLOOK...
MONDAY AND TUESDAY...GENERALLY VFR AS A QUICK MOVING SYSTEM SLIDES
TO OUR SOUTH MONDAY. IT APPEARS THAT ANY LIGHT PRECIPITATION STAYS
SOUTH OF ALL OF OUR TERMINALS. A NORTH TO NORTHWEST WIND HOWEVER
SHOULD INCREASE FOR A TIME BEHIND THIS FEATURE, THEN LESS WIND
TUESDAY AS HIGH PRESSURE BEGINS TO SETTLE IN.
WEDNESDAY AND THURSDAY...HIGH PRESSURE SHIFTS TO OUR EAST ALLOWING
FOR A STRENGTHENING SOUTHWESTERLY WIND. THIS SHOULD TURN GUSTY AT
TIMES ESPECIALLY DURING EACH AFTERNOON AS MIXING IS MORE EFFICIENT.
THE MOISTURE SHOULD BE ON THE INCREASE LATE WEDNESDAY AND THURSDAY,
HOWEVER THERE IS LOWER CONFIDENCE WHETHER OR NOT THIS LEADS TO AREAS
OF LOWER CLOUDS AND/OR SOME FOG.
&&
.MARINE...
SEAS HAVE DROPPED BELOW 5 FEET ON THE OCEAN...AND THE SMALL CRAFT
THERE WAS CANCELLED. A SMALL CRAFT ADVISORY WAS ISSUED FOR TONIGHT
FOR THE OCEAN WATERS AND THE LOWER DELAWARE BAY. DETAILS ARE
CONTAINED BELOW.
A COLD FRONT OVER THE ST LAWRENCE RIVER VALLEY AND THE GREAT LAKES
WILL DROP TOWARD THE WATERS THIS AFTERNOON...AND LIMP ACROSS THE
WATERS THIS EVENING. AHEAD OF THE FRONT...THE GRADIENT WILL START TO
TIGHTEN...AND WESTERLY GUSTS COULD GET CLOSE TO 25 KNOTS ON THE
OCEAN WATERS (ESPECIALLY NEARSHORE) BY EVENING.
THE BEST GRADIENT BEHIND THE FRONT OCCURS THIS EVENING INTO THE
EARLY PART OF THE OVERNIGHT. THE 925 FLOW SHOULD 25 TO 30 KNOTS OF
WIND AVAILABLE DURING THIS TIME...AND MODEL SOUNDINGS SHOW THE DEPTH
OF THE MIXED LAYER SUFFICIENTLY DEEP TO TAP THESE WINDS. SMALL CRAFT
WIND GUSTS SHOULD OCCUR ON ALL OCEAN WATERS...AND THE LOWER DELAWARE
BAY. THE FLOW STARTS TO BACK OFF AFTER 0900 UTC...AND BY 1200 UTC
THE SMALL CRAFT WIND GUSTS SHOULD DROP BACK BELOW 25 KNOTS.
A CLIPPER TYPE SYSTEM QUICKLY TRACKS TO OUR SOUTH AND EAST MONDAY
AND MONDAY NIGHT. THIS SYSTEM IS FORECAST TO STRENGTHEN TO OUR EAST,
THEREFORE THE PRESSURE GRADIENT WILL TIGHTEN UP IN RESPONSE LATER
MONDAY. THIS ALONG WITH SOME CAA MAY ALLOW THE WINDS TO RAMP UP TO
ADVISORY LEVELS FOR A TIME MONDAY NIGHT. HIGH PRESSURE THEN SETTLES
ACROSS OUR AREA TUESDAY WITH LIGHTER WINDS EVENTUALLY BECOMING
SOUTHERLY. THE SURFACE HIGH BECOMES ESTABLISHED TO OUR EAST
WEDNESDAY AND THURSDAY, WHICH WILL MAINTAIN A SOUTHERLY FLOW. THE
AIRMASS WILL BE MODERATING, THEREFORE THE DEPTH OF THE LOW-LEVEL
MIXING MAY BECOME LESS DESPITE THE WIND FIELD ABOVE THE SURFACE
GRADUALLY STRENGTHENING. IF WE CAN MIX ENOUGH LATER WEDNESDAY AND
THURSDAY, THEN GUSTS MAY REACH ADVISORY LEVELS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 4 AM EST MONDAY
FOR ANZ431-450>455.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...GIGI/HAYES
SHORT TERM...HAYES
LONG TERM...GORSE
AVIATION...GORSE/HAYES
MARINE...GORSE/HAYES
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
751 AM CST SUN MAR 4 2012
.UPDATE...
HAVE UPDATED THE FORECAST FOR PERIOD OF SUNSHINE THIS MORNING AND
TO DELAY THE ONSET OF LIGHT SNOW AND FLURRIES IN THE WEST. BASED
ON SLOWER TIMING OF THE LATEST RUC AND NAM...THE DEVELOPING LIGHT
SNOW WITH THE CLIPPER SYSTEM NOW OVER THE EASTERN DAKOTAS WILL NOT
REACH CENTRAL IA UNTIL 18Z...AND MAY NOT DEVELOP INTO MEASURABLE
LIGHT SNOW IN OUR WESTERN COUNTIES UNTIL 1 OR 2 PM. EXPECTED SNOW
AMOUNTS LOOK ON TRACK...BUT MODEL TRENDS ARE SUGGESTING A SLIGHT
SW SHIFT MAY TAKE PLACE. ..SHEETS..
&&
.AVIATION... /ISSUED 559 AM CST SUN MAR 4 2012/
A FAST MOVING WINTER STORM SYSTEM OVER THE NORTHERN PLAINS WILL
SPREAD LIGHT SNOW ACROSS CENTRAL AND SE IA INTO W CENTRAL IL THIS
AFTERNOON. AFTER A BREAK THIS MORNING...LOW CLOUDS WILL RETURN BY
EARLY AFTERNOON AS THE SYSTEM APPROACHES. CIGS WILL LOWER TO MVFR
AT CID...MLI AND DBQ BY EARLY AFTERNOON...FOLLOWED BY DEVELOPING
SNOW THAT WILL RESTRICT VISBYS TO 3 TO 5SM FOR SEVERAL HOURS. BRL
WILL HAVE THE GREATEST IMPACT...AND HAVE IFR CONDITIONS FOR A PERIOD
IN THE AFTERNOON DUE TO LOWERING CIGS AND VISBYS IN LIGHT SNOW.
DBQ WILL LIKELY BE ON THE FRINGE OF THIS SYSTEM AND FOR NOW HAVE
LIMITED THE IMPACT TO AFTERNOON VCSH WORDING FOR FLURRIES WITH VFR
CONDITIONS OTHERWISE...ONCE THE LOW CLOUDS IN THE AREA EARLY THIS
MORNING PUSH EAST. ALL SITES ARE EXPECTED TO SEE CLEARING
SKIES AND VFR CONDITIONS OVERNIGHT.
..SHEETS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1008 AM EST SUN MAR 4 2012
.SYNOPSIS...
LOW PRESSURE WILL PUSH AWAY FROM MID-ATLANTIC COAST THIS
MORNING..WITH HIGH PRESSURE BRIEFLY BUILDING IN THIS AFTERNOON
AND TONIGHT. A QUICK MOVING LOW PRESSURE SYSTEM WILL APPROACH THE
REGION LATE TONIGHT...TRACKING ACROSS THE VIRGINIA...NORTH
CAROLINA BORDER MONDAY. HIGH PRESSURE RETURNS MONDAY NIGHT AND
TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST GOES VISIBLE AND LONGWAVE IR CHANNELS ARE SHOWING CLEARING
MOVING INTO THE PIEDMONT COUNTIES WITH DENSE CLOUD COVER REMAINING
OVER THE COAST. WATER VAPOR IMAGERY CONTINUES TO SHOW BACKING SSW
FLOW ALONG THE ATLANTIC COAST AS A TROUGH DIGS ACROSS THE DEEP
SOUTH. HOWEVER...A SUBTLE EASTWARD SHIFT OF THE WARM MOIST CONVEYOR
ALONG THE COAST IS OCCURRING AS A SECONDARY TROUGH DIGS ACROSS THE
NORTHERN PLAINS AND UPPER RIDGING EXPANDS OVER THE WEST. LATEST
OBS AND RADAR IMAGERY CONTINUE TO SHOW RAIN OVER NE NC AND THE
TIDEWATER...ALTHOUGH DRIER AIR IS ATTEMPTING ERODE THE WESTERN
EDGE. AT THIS POINT RAIN IS EXPECTED TO CONTINUE OVER THESE AREAS
UNTIL AROUND NOON BEFORE THE WESTERN EDGE SIMULTANEOUSLY ERODES
AND MOVES OFF THE COAST. RAWS/ASOS/AWOS OBS INDICATE AROUND 0.5-1
IN OF RAIN SINCE MIDNIGHT ALONG AND SE OF A LINE FROM ASJ TO
ORF...WITH MUCH LESSER AMOUNTS TO THE NW AND ZERO OR TRACE AMOUNTS
FROM AVC-PTB-SBY NW. OF NOTE...RADAR ESTIMATES APPEAR TOO HIGH
BASED ON BRIGHT BANDING.
ANOTHER ROUND OF SHOWERS EXPECTED PER BOTH THE HRRR AND NAM12 EAST
OF I-95 AS THE UPPER TROUGH AXIS SWINGS THROUGH THIS
AFTERNOON, AND HAVE ALLOWED FOR A BRIEF PERIOD OF SHOWERS DURING
THE 18-22Z PERIOD. OTHERWISE A WEST TO EAST IMPROVING TREND IS
EXPECTED FOR THE AFTN. MODEL SOUNDINGS INDICATING STRONG COOLING
ALOFT AS TROUGH APPROACHES AND SFC TROUGH SLIDES NE AWAY FROM THE
REGION. HAVE NOT ACCOUNTED FOR THIS IN THE FORECAST DUE TO LOW
PROBABILITY, BUT WOULD NOT BE SURPRISED TO SEE A FEW WET
SNOWFLAKES MIX IN WITH RAIN SHRAS AS PCPN ENDS THIS AFTERNOON.
DRIER AIRMASS PULLING IN FROM THE WEST SHOULD MAKE ANY PCPN RATHER
SPOTTY, AND WARM BL WILL OBVIOUSLY PRECLUDE ANY SNOWFALL
ACCUMULATION ISSUES TODAY. THERE MAY BE ENOUGH INSTABILITY AND
MIXED-PHASE PRECIP FOR A FEW RUMBLES OF THUNDER. THIS CONVECTIVE
SHOWER POTENTIAL WILL BE RE-ADDRESSED AT THE NEXT UPDATE WITHIN
2-3 HOURS.
FOR HIGHS...TEMPERATURES WILL BE CHALLENGING TODAY ESPECIALLY THIS
AFTERNOON. TEMPERATURES ARE ALREADY RUNNING 2-3 DEGREES WARMER
THAN LAMP/HRRR NUMBERS AND HV ACCORDINGLY STAYED ON THE WARM SIDE
FOR THE MORNING. DOWNSLOPE FLOW INLAND AS SYSTEM EXITS SHOULD
MAKE FOR DRYING/CLEARING CONDITIONS AND AT LEAST A PARTLY SUNNY
SKY INLAND. HAVE STAYED CLOSE TO MET/MAV BLEND OVER THIS AREA,
WITH LOW 50S FROM PREVIOUS FORECAST GENERALLY ACCEPTED WEST OF
I-95. CLOSER TO THE COAST, WITH LOW CLOUDS AND SHOWERY CONDITIONS
EXPECTED TO LAST A BIT LONGER, HAVE GONE CLOSE TO THE MAV
NUMBERS...AS NAM CONTINUES TO SEEMINGLY OVER-EMPHASIZE DYNAMICAL
COOLING ALONG THE COAST. HIGHS IN THE UPPER 40S TO NEAR 50 AT THE
COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
CLEARING SKY EARLY THIS EVENING WITH SHORT-LIVED LULL ON THE BACK
SIDE OF DEPARTING SYSTEM. TEMPERATURES LOOK TO FALL RATHER QUICKLY
SUNDAY NIGHT AS WINDS BRIEFLY DROP OFF AND SKY REMAINS CLEAR EARLY
IN THE EVENING. EXPECT CLOUDS TO INCREASE FROM WEST TO EAST LATE
TONIGHT AHEAD OF VIGOROUS MID-LEVEL TROUGH WHICH WILL SLIDE ACROSS
THE CENTRAL APPALACHIANS TOWARDS THE REGION LATE TONIGHT.
MODELS NOW IN RELATIVELY GOOD AGREEMENT WITH THIS TROUGH (CLIPPER
SYSTEM) AS IT CROSSES THE MID ATLANTIC MONDAY...WITH THE
ASSOCIATED SURFACE LOW TRACKING ACROSS/JUST SOUTH OF THE VA/NC
BORDER. THE THERMAL PROFILE ALOFT CRASHES WITH THIS
SYSTEM...1000-500MB THICKNESS VALUES AROUND 5250M AND LOW-LEVEL
THICKNESS VALUES RANGE FROM AROUND 1290M N...TO 1310M S. THIS
WOULD SUPPORT THE POSSIBILITY OF A PERIOD OF LIGHT SNOW AS PCPN
ARRIVES AFTER 09Z/MONDAY. AT THIS POINT THE PRECIP TYPE GENERALLY
REFLECTS SREF PROBABILITIES...WHICH HAVE TRENDED UPWARDS NICELY
WITH THE 21Z/03 SUITE, ALTHOUGH AGREE WITH HPC THAT THIS IS LIKELY
ATTRIBUTABLE AT LEAST IN PART TO THE (LIKELY ERRONEOUSLY) COLDER
NAM MEMBERS. STILL...CONFIDENCE IS HIGH ENOUGH TO INCREASE TO HIGH
CHC TO LIKELY POP WEST OF RIC METRO MONDAY MORNING...WITH HIGH CHC
POP FOR MAINLY LIQUID PCPN LATER MONDAY MORNING. QPF WITH THIS
EVENT WILL BE RATHER LOW, ON THE ORDER OF TWO TENTHS OR LESS AS
PER SREF ENSEMBLES. TIMING OF THIS EVENT, WITH LIGHT SNOW
BEGINNING JUST PRIOR TO DIURNAL HEATING SHOULD AT LEAST PARTIALLY
NEGATE MARGINAL BL TEMPERATURES INITIALLY, LEAVING THE POTENTIAL
FOR A LIGHT SNOWFALL ACCUMULATION (~1") ON GRASSY/ELEVATED SFCS
MONDAY MORNING BEFORE QUICKLY MIXING AND TURNING OVER TO RAIN
LATER MONDAY MORNING.
GIVEN EARLY MARCH SUN ANGLE AND MARGINAL BL CONDITIONS, HEAVIER
SNOW RATES WOULD BE NEEDED FOR ANY ACCUMULATIONS ALONG AND EAST OF
THE I-95 CORRIDOR, AND FORECAST CONFIDENCE NOT HIGH AT ALL FOR
THAT OCCURRING. CLEARING COMES QUICKLY BEHIND THE SYSTEM...BY
LATE MORN INLAND INTO THE LATE AFTN COASTAL ZONES. FOR TEMPERATURES,
LOOK FOR HIGHS MONDAY MID/UPPER 40S.
HIGH PRESSURE BUILDS IN FROM THE WEST MONDAY NIGHT AND BECOMES
CENTERED OVER THE MID ATLANTIC TUESDAY BRINGING COOL PLEASANT
CONDITIONS. LOW TEMPERATURES TUESDAY MORNING SHOULD RANGE FROM THE
MID 20S TO LOW 30S...FOLLOWED BY HIGHS IN THE MID 40S EASTERN
SHORE...TO LOW 50S PIEDMONT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL BE CENTERED OVER THE MID ATLANTIC WEDNESDAY
DRIFTING SLOWLY EAST WEDNESDAY NIGHT AND THURSDAY. TEMPERATURES
WILL REBOUND INTO THE LOW TO MID 60S WITH LOWS MODERATING IN THE
LOW TO MID 40S WEDNESDAY NIGHT WITH DEEPENING SOUTHERLY FLOW.
SOUTHERLY FLOW INCREASES THURSDAY AS THE REGION BECOMES SQUEEZED
BETWEEN THE HIGH MOVING OFFSHORE AND THE NEXT APPROACHING STORM
SYSTEM. EVEN WITH SOME INCREASING HIGH CLOUDS THURSDAY
TEMPERATURES WILL WARM INTO THE UPPER 60 TO LOWER 70S.
CHANCES FOR PRECIPITATION WILL HOLD OFF UNTIL LATE FRIDAY OR
SATURDAY. THERE IS MUCH DISAGREEMENT IN THE MODELS REGARDING THE
FORECAST FOR FRIDAY AND SATURDAY. THE ECMWF HAS BEEN MUCH MORE
AMPLIFIED WITH THE NEXT UPPER TROUGH THAN THE GFS AND CANADIAN. IN
RESPONSE THE ECMWF DEVELOPED A SURFACE WAVE OVER THE SOUTHEAST
BRINGING IT INTO THE MID ATLANTIC FRIDAY NIGHT. THE GFS IS WEAKER
AND SLOWER WITH THE SYSTEM HOLDING OFF THE RAIN UNTIL SATURDAY.
THERE WILL BE DISTURBED WEATHER IN THE EXTENDED WITH GOOD CHANCES
FOR PRECIPITATION AT SOME POINT FROM LATE FRIDAY THROUGH SATURDAY.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AS OF 11Z...LIGHT RAIN WAS OVER PHF ORF AND ECG AND IS NOT EXPECTED
TO REACH SBY OR RIC. VSBYS WILL OCCASIONALLY LOWER TO AROUND 5
MILES IN THE PCPN. CEILINGS HAVE REMAINED SURPRISINGLY HIGH AND
MOST LIKELY ORF AND PHF WILL REMAIN ABOVE 3K FT. TOOK ECG DOWN TO
025 FROM 15-19Z WHERE CONDITIONS ARE MORE MOIST. PCPN SHOULD END
FROM W TO E BY AROUND MIDDAY. DOWNSLOPE WINDS WILL BRING MOSTLY
CLEAR SKIES TO THE AREA BY LATE THIS AFTN OR EARLY THIS EVENING.
OUTLOOK...CLOUDS INCREASE MONDAY MORNING AS PCPN LIKELY SPREADS
EAST IN ASSOCIATION WITH A CLIPPER SYSTEM. BRIEF IFR IS PSBL
ESPECIALLY AT RIC WHERE PCPN SHOULD BEGIN AS SNOW. CONDITIONS
IMPROVE BY LATE MONDAY. EXPECT VFR TO THEN PREVAIL THROUGH THURSDAY.
&&
.MARINE...
A NORTHERLY SURGE COUNTIES THROUGH THE SOUTHERN WATERS THIS MORNING
WITH THE DEEPENING LOW OFFSHORE. CONDITIONS WILL BE CLOSE TO SCA BUT
SHOULD STAY JUST BELOW SCA. SEAS WILL RUN 3-4 FEET WITH UP TO 5 FEET
IN THE COASTAL WATERS ALONG AND S OF THE NC/VA BORDER. WINDS
INCREASE OUT OF THE WEST ONCE AGAIN EARLY MONDAY MORNING AND
MARGINAL SCA FOR WINDS AND SEAS ARE POSSIBLE. CONFIDENCE TOO LOW TO
ADD SCA AT THIS TIME.
A CLIPPER SYSTEM TO MOVE THROUGH THE AREA MONDAY. AS THIS MOVES
OFFSHORE LATE MONDAY...THE SURFACE LOW WILL INTENSIFY. WINDS
INCREASE OUT OF THE NW AND SCA CRITERIA IS LIKELY MONDAY EVENING
THROUGH EARLY TUESDAY ACROSS ALL OF THE WATERS. NO OTHER MARINE
ISSUES APPEAR THROUGH MID WEEK.
&&
.HYDROLOGY...
MINOR FLOODING CONTINUES AT THE WESTHAM GAGE AT RICHMOND. RIVER
LEVELS WILL CONTINUE DROPPING TODAY...BELOW FLOOD STAGE BY LATE
AFTN OR EARLY EVENING. SEE WBCFLSAKQ FOR MORE INFORMATION.
&&
.CLIMATE...
SEE WBCPNSAKQ FOR DETAILS ON METEOROLOGICAL WINTER (DEC-FEB) AT
RICHMOND AND NORFOLK (BOTH BEING 4TH WARMEST ON RECORD).
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM/AJZ
SHORT TERM...MAM/AJZ
LONG TERM...JAO
AVIATION...LSA
MARINE...LSA/JO
HYDROLOGY...AKQ
CLIMATE...AKQ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
655 AM EST SUN MAR 4 2012
.SYNOPSIS...
LOW PRESSURE WILL PUSH AWAY FROM MID-ATLANTIC COAST THIS
MORNING..WITH HIGH PRESSURE BRIEFLY BUILDING IN THIS AFTERNOON
AND TONIGHT. A QUICK MOVING LOW PRESSURE SYSTEM WILL APPROACH THE
REGION LATE TONIGHT...TRACKING ACROSS THE VIRGINIA...NORTH
CAROLINA BORDER MONDAY. HIGH PRESSURE RETURNS MONDAY NIGHT AND
TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST IR/WV IMAGERY SHOWING AMPLIFYING UPPER LEVEL TROUGH PUSHING
ACROSS/INTO THE LOWER MISSISSIPPI VALLEY THIS MORNING. TO THE
SOUTHEAST...OLD COLD FRONTAL BOUNDARY REMAINS STALLED JUST OFF THE
CAROLINA/SOUTHEAST COAST WITH A WEAK SFC REFLECTION MOVING ALONG
IT JUST OFF THE NC COAST. BACKING SOUTHERLY FLOW IN MID LEVELS,
OWING TO ARRIVING TROUGH FROM THE WEST, HAS ALLOWED FOR A NARROW
BAND OF SHRAS TO DEVELOP THIS MORNING. AS EXPECTED, THIS ACTIVITY
HAS REMAINED MAINLY ACROSS CAROLINAS INTO SE VA...OR MAINLY FROM
EMV TO ORF TO WAL ACROSS AKQLAND. HAVE ALLOWED FOR CATEGORICAL
POPS THROUGH MID MORNING OVER THESE AREAS, BUFFERED BY SLIGHT TO
LOW CHC POP FOR THE REST OF THE MORNING JUST TO THE NORTH INTO
SOUTHERN EXTENT OF RIC METRO INTO THE NORTHERN NECK AND ATLANTIC
COASTAL SIDE OF MD EASTERN SHORE (MAINLY ALONG/EAST OF HIGHWAY
113). GRADUALLY DIMINISH POP FOR LATE MORNING INTO THE EARLY AFTN
AS BEST FORCING GETS SHUNTED OFFSHORE AS TROUGH TO THE WEST PIVOTS
EAST.
ANOTHER ROUND OF SHOWERS EXPECTED PER BOTH THE HRRR AND NAM12 EAST
OF I-95 AS THE UPPER TROUGH AXIS SWINGS THROUGH THIS
AFTERNOON, AND HAVE ALLOWED FOR A BRIEF PERIOD OF SHOWERS DURING
THE 18-22Z PERIOD. OTHERWISE A WEST TO EAST IMPROVING TREND IS
EXPECTED FOR THE AFTN. MODEL SOUNDINGS INDICATING STRONG COOLING
ALOFT AS TROUGH APPROACHES AND SFC TROUGH SLIDES NE AWAY FROM THE
REGION. HAVE NOT ACCOUNTED FOR THIS IN THE FORECAST DUE TO LOW
PROBABILITY, BUT WOULD NOT BE SURPRISED TO SEE A FEW WET
SNOWFLAKES MIX IN WITH RAIN SHRAS AS PCPN ENDS THIS AFTERNOON.
DRIER AIRMASS PULLING IN FROM THE WEST SHOULD MAKE ANY PCPN RATHER
SPOTTY, AND WARM BL WILL OBVIOUSLY PRECLUDE ANY SNOWFALL
ACCUMULATION ISSUES TODAY.
FOR HIGHS...TEMPERATURES WILL BE CHALLENGING TODAY ESPECIALLY THIS
AFTERNOON. TEMPERATURES ARE ALREADY RUNNING 2-3 DEGREES WARMER
THAN LAMP/HRRR NUMBERS AND HV ACCORDINGLY STAYED ON THE WARM SIDE
FOR THE MORNING. DOWNSLOPE FLOW INLAND AS SYSTEM EXITS SHOULD
MAKE FOR DRYING/CLEARING CONDITIONS AND AT LEAST A PARTLY SUNNY
SKY INLAND. HAVE STAYED CLOSE TO MET/MAV BLEND OVER THIS AREA,
WITH LOW 50S FROM PREVIOUS FORECAST GENERALLY ACCEPTED WEST OF
I-95. CLOSER TO THE COAST, WITH LOW CLOUDS AND SHOWERY CONDITIONS
EXPECTED TO LAST A BIT LONGER, HAVE GONE CLOSE TO THE MAV
NUMBERS...AS NAM CONTINUES TO SEEMINGLY OVER-EMPHASIZE DYNAMICAL
COOLING ALONG THE COAST. HIGHS IN THE UPPER 40S TO NEAR 50 AT THE
COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
CLEARING SKY EARLY THIS EVENING WITH SHORT-LIVED LULL ON THE BACK
SIDE OF DEPARTING SYSTEM. TEMPERATURES LOOK TO FALL RATHER QUICKLY
SUNDAY NIGHT AS WINDS BRIEFLY DROP OFF AND SKY REMAINS CLEAR EARLY
IN THE EVENING. EXPECT CLOUDS TO INCREASE FROM WEST TO EAST LATE
TONIGHT AHEAD OF VIGOROUS MID-LEVEL TROUGH WHICH WILL SLIDE ACROSS
THE CENTRAL APPALACHIANS TOWARDS THE REGION LATE TONIGHT.
MODELS NOW IN RELATIVELY GOOD AGREEMENT WITH THIS TROUGH (CLIPPER
SYSTEM) AS IT CROSSES THE MID ATLANTIC MONDAY...WITH THE
ASSOCIATED SURFACE LOW TRACKING ACROSS/JUST SOUTH OF THE VA/NC
BORDER. THE THERMAL PROFILE ALOFT CRASHES WITH THIS
SYSTEM...1000-500MB THICKNESS VALUES AROUND 5250M AND LOW-LEVEL
THICKNESS VALUES RANGE FROM AROUND 1290M N...TO 1310M S. THIS
WOULD SUPPORT THE POSSIBILITY OF A PERIOD OF LIGHT SNOW AS PCPN
ARRIVES AFTER 09Z/MONDAY. AT THIS POINT THE PRECIP TYPE GENERALLY
REFLECTS SREF PROBABILITIES...WHICH HAVE TRENDED UPWARDS NICELY
WITH THE 21Z/03 SUITE, ALTHOUGH AGREE WITH HPC THAT THIS IS LIKELY
ATTRIBUTABLE AT LEAST IN PART TO THE (LIKELY ERRONEOUSLY) COLDER
NAM MEMBERS. STILL...CONFIDENCE IS HIGH ENOUGH TO INCREASE TO HIGH
CHC TO LIKELY POP WEST OF RIC METRO MONDAY MORNING...WITH HIGH CHC
POP FOR MAINLY LIQUID PCPN LATER MONDAY MORNING. QPF WITH THIS
EVENT WILL BE RATHER LOW, ON THE ORDER OF TWO TENTHS OR LESS AS
PER SREF ENSEMBLES. TIMING OF THIS EVENT, WITH LIGHT SNOW
BEGINNING JUST PRIOR TO DIURNAL HEATING SHOULD AT LEAST PARTIALLY
NEGATE MARGINAL BL TEMPERATURES INITIALLY, LEAVING THE POTENTIAL
FOR A LIGHT SNOWFALL ACCUMULATION (~1") ON GRASSY/ELEVATED SFCS
MONDAY MORNING BEFORE QUICKLY MIXING AND TURNING OVER TO RAIN
LATER MONDAY MORNING.
GIVEN EARLY MARCH SUN ANGLE AND MARGINAL BL CONDITIONS, HEAVIER
SNOW RATES WOULD BE NEEDED FOR ANY ACCUMULATIONS ALONG AND EAST OF
THE I-95 CORRIDOR, AND FORECAST CONFIDENCE NOT HIGH AT ALL FOR
THAT OCCURRING. CLEARING COMES QUICKLY BEHIND THE SYSTEM...BY
LATE MORN INLAND INTO THE LATE AFTN COASTAL ZONES. FOR TEMPERATURES,
LOOK FOR HIGHS MONDAY MID/UPPER 40S.
HIGH PRESSURE BUILDS IN FROM THE WEST MONDAY NIGHT AND BECOMES
CENTERED OVER THE MID ATLANTIC TUESDAY BRINGING COOL PLEASANT
CONDITIONS. LOW TEMPERATURES TUESDAY MORNING SHOULD RANGE FROM THE
MID 20S TO LOW 30S...FOLLOWED BY HIGHS IN THE MID 40S EASTERN
SHORE...TO LOW 50S PIEDMONT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL BE CENTERED OVER THE MID ATLANTIC WEDNESDAY
DRIFTING SLOWLY EAST WEDNESDAY NIGHT AND THURSDAY. TEMPERATURES
WILL REBOUND INTO THE LOW TO MID 60S WITH LOWS MODERATING IN THE
LOW TO MID 40S WEDNESDAY NIGHT WITH DEEPENING SOUTHERLY FLOW.
SOUTHERLY FLOW INCREASES THURSDAY AS THE REGION BECOMES SQUEEZED
BETWEEN THE HIGH MOVING OFFSHORE AND THE NEXT APPROACHING STORM
SYSTEM. EVEN WITH SOME INCREASING HIGH CLOUDS THURSDAY
TEMPERATURES WILL WARM INTO THE UPPER 60 TO LOWER 70S.
CHANCES FOR PRECIPITATION WILL HOLD OFF UNTIL LATE FRIDAY OR
SATURDAY. THERE IS MUCH DISAGREEMENT IN THE MODELS REGARDING THE
FORECAST FOR FRIDAY AND SATURDAY. THE ECMWF HAS BEEN MUCH MORE
AMPLIFIED WITH THE NEXT UPPER TROUGH THAN THE GFS AND CANADIAN. IN
RESPONSE THE ECMWF DEVELOPED A SURFACE WAVE OVER THE SOUTHEAST
BRINGING IT INTO THE MID ATLANTIC FRIDAY NIGHT. THE GFS IS WEAKER
AND SLOWER WITH THE SYSTEM HOLDING OFF THE RAIN UNTIL SATURDAY.
THERE WILL BE DISTURBED WEATHER IN THE EXTENDED WITH GOOD CHANCES
FOR PRECIPITATION AT SOME POINT FROM LATE FRIDAY THROUGH SATURDAY.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 11Z...LIGHT RAIN WAS OVER PHF ORF AND ECG AND IS NOT EXPECTED
TO REACH SBY OR RIC. VSBYS WILL OCCASIONALLY LOWER TO AROUND 5
MILES IN THE PCPN. CEILINGS HAVE REMAINED SURPRISINGLY HIGH AND
MOST LIKELY ORF AND PHF WILL REMAIN ABOVE 3K FT. TOOK ECG DOWN TO
025 FROM 15-19Z WHERE CONDITIONS ARE MORE MOIST. PCPN SHOULD END
FROM W TO E BY AROUND MIDDAY. DOWNSLOPE WINDS WILL BRING MOSTLY
CLEAR SKIES TO THE AREA BY LATE THIS AFTN OR EARLY THIS EVENING.
OUTLOOK...CLOUDS INCREASE MONDAY MORNING AS PCPN LIKELY SPREADS
EAST IN ASSOCIATION WITH A CLIPPER SYSTEM. BRIEF IFR IS PSBL
ESPECIALLY AT RIC WHERE PCPN SHOULD BEGIN AS SNOW. CONDITIONS
IMPROVE BY LATE MONDAY. EXPECT VFR TO THEN PREVAIL THROUGH THURSDAY.
&&
.MARINE...
A NORTHERLY SURGE WAS MOVING THROUGH THE WATERS THIS MORNING BUT
SHOULD STAY JUST BELOW SCA CRITERIA. WINDS INCREASE OUT OF THE
WEST ONCE AGAIN EARLY MONDAY MORNING AND MARGINAL SCA FOR WINDS
AND SEAS ARE POSSIBLE. CONFIDENCE TOO LOW TO ADD SCA AT THIS TIME.
A CLIPPER SYSTEM TO MOVE THROUGH THE AREA MONDAY. AS THIS MOVES
OFFSHORE LATE MONDAY...THE SURFACE LOW WILL INTENSIFY. WINDS
INCREASE OUT OF THE NW AND SCA CRITERIA IS LIKELY MONDAY EVENING
THROUGH EARLY TUESDAY ACROSS ALL OF THE WATERS. NO OTHER MARINE
ISSUES APPEAR THROUGH MID WEEK.
&&
.HYDROLOGY...
MINOR FLOODING CONTINUES AT THE WESTHAM GAGE AT RICHMOND. RIVER
LEVELS WILL CONTINUE DROPPING TODAY...BELOW FLOOD STAGE BY EARLY
AFTN. SEE WBCFLSAKQ FOR MORE INFORMATION.
&&
.CLIMATE...
SEE WBCPNSAKQ FOR DETAILS ON METEOROLOGICAL WINTER (DEC-FEB) AT
RICHMOND AND NORFOLK (BOTH BEING 4TH WARMEST ON RECORD).
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAM/AJZ
LONG TERM...JAO
AVIATION...LSA
MARINE...LSA
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
626 AM EST SUN MAR 4 2012
.SYNOPSIS...
SNOW SHOWERS AND COLD WEATHER WILL BE THE RULE TODAY AS A
SECONDARY COLD FRONT PUSHES SOUTHEAST FROM CANADA. HIGH PRESSURE
WILL BUILD INTO THE AREA BY LATE MONDAY AND CONTINUE THROUGH MID-
WEEK WITH THE NEXT CHANCE OF RAIN BY LATE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
625 AM UPDATE...UPDATED POPS IN THE SHORT TERM FOR INCREASE IN
SCATTERED -SHSN THIS MORNING. MUCH OF COVERAGE AT THIS LIMITED AND
VERY LIGHT. AS SURFACE TROUGH PUSHES SE DURING DAY...EXPECT -SHSN
COVERAGE TO INCREASE. THINK HRRR HAS GOOD HANDLE ON AREAL COVERAGE
INCREASE AND TIMING. TEMPERATURES LOOK ON TRACK. PREVIOUS
DISCUSSION FOLLOWS...
SECONDARY COLD FRONT WILL BE APPROACHING
SECONDARY COLD FRONT ST. LAWRENCE VALLEY SOUTHWEST ACROSS LAKES
ONTARIO AND ERIE TO NEAR KLAN AND THEN TO KORD WILL CONTINUE SOUTH
AND EAST TODAY. SNOW SHOWERS SHOULD DEVELOP IN ADVANCE AND WITH
FRONT AND THEN BE SLIGHTLY ENHANCED BY LAKE EFFECT BEHIND FRONT.
SNOW ACCUMULATIONS LIMITED WITH MAYBE 1-2 INCHES EXTREME NORTHERN
COUNTIES...2-3 INCHES MOUNTAINS AND LESS THAN INCH ELSEWHERE.
WINDS TO INCREASE A LITTLE FROM WEST THEN NORTHWEST WITH SOME
GUSTS 15 TO 20 KTS BEHIND FRONT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
ALL OF THE WX TAKES PLACE RIGHT OF THE GATE MON AS A STRONG
SHORTWAVE TROUGH INTERACTS WITH SUFFICIENT LLVL MOISTURE IN THE
RIDGES. INCREASED POPS TO LKLY FOR GARRETT AND TUCKER COUNTIES
WITH CHC NUMBERS FOR ADJACENT LOCATIONS. ANY DAYTIME SNOW ACCUM
WILL BE AN INCH OR LESS. WINTER PCPN QUICKLY ENDS MON EVENING AS
MID LEVEL ENERGY MOVES EAST. DRY WEATHER IS ANTICIPATED THE
BALANCE OF THE SHORT TERM AS HIGH PRESSURE CONTROLS OUR WEATHER.
TEMPERATURES WILL GET WARMER EACH SUCCESSIVE DAY / NIGHT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
0Z RUNS ARE STRONGER WITH MID WEEK SE CONUS ANTICYCLONE THEREBY
DELAY FROPA 12-24HRS FROM PREVIOUS RUNS. AS A RESULT...CONTINUED
DRY WEATHER THROUGH WEDNESDAY NIGHT INTO EARLY THURSDAY MRNG.
TEMPERATURES WILL BE AFFECTED AS WELL. OVERNIGHT LOWS WED NGT WILL
BE QUITE WARM UNDER A WELL MIXED BOUNDARY LAYER WITH MOST LOCATIONS
STAYING WELL INTO THE 40S AND LOWER 50S. THURSDAY WILL BE THE
WARMEST DAY OF THE WEEK AS LWR 60S SHOULD BE OBSERVED FROM ZZV - IDI
AND POINTS S.
DO NOT EXPECT CONVECTIVE ACTIVITY WITH COLD FRONT THURSDAY DESPITE
CURRENT AFTERNOON TIMING. STILL LOTS OF UNCERTAINTY WITH THE BACK
END OF THE FORECAST. ECMWF CONTS TO BRING A FULL LATITUDE TROF OVER
THE ERN U.S. RESULTING IN SCT SHSN FRI INTO SAT...WHILE GFS IS MORE
PROGRESSIVE AS PCPN SHUTS OFF FRI AND SEASONAL DRY WX SAT. DID
NOT MAKE ANY CHANGES TO GRIDDED DATA SET DAY 6 AND 7 DUE TO LOW
CONFIDENCE.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
-SHSN TO DEVELOP WITH SECONDARY FRONT PUSHING SE FROM THE LAKES. AT
THIS TIME DON`T EXPECT MUCH RESTRICTION TO VSBY WITH ONLY 5SM.
HOWEVER, 5-6+ SM IN -SHSN PROBABLY MOST OF THE DAY. CEILINGS
GENERALLY 30K-35K. WEST WINDS 8-12 WILL BECOME NW WITH SOME GUSTS
15-20KTS THIS AFTERNOON. SMALL CLIPPER-TYPE SYSTEM TO DIVE SOUTH
OF REGION TONIGHT.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
HIGH PRESSURE BUILDS IN THE AREA ON MONDAY AND CONTOURS TO DOMINATE
THE WEATHER THROUGH THURSDAY WITH VFR CONDITIONS. NEXT FRONT
APPROACHES ON THURSDAY WITH MVFR AND SCATTERED IFR IN SHOWERS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
542 AM CST SUN MAR 4 2012
.AVIATION...12Z TAFS
AN INVERTED TROUGH AND ONSHORE WINDS WERE COMBINING TO PRODUCE
SNOW OVER THE TWIN PORTS NORTH THROUGH SILVER BAY...WITH LIGHTER
SNOW FALLING IN SPOTS ACROSS THE THE REST OF THE NORTHLAND. THERE
HAS BEEN CLEARING THAT HAS MOVED AS FAR EAST AS K04W NORTH TO JUST
WEST OF KHIB TO KBDE. WE EXPECT MVFR CEILINGS WITH OCCASIONAL LOW
VFR OVER FAR EASTERN MINNESOTA AND MUCH OF NORTHWEST WISCONSIN
TODAY. CLOUDS MAY SCATTER OUT AT KHIB/KINL FOR A TIME...BUT A
CLIPPER MOVING SOUTHWEST OF THE NORTHLAND WILL BRING IN MORE
CLOUDS TODAY. CEILINGS MAY INITIALLY BE LOW VFR...BUT MVFR
CEILINGS WILL THEN DEVELOP. THE HEAVIEST LAKE EFFECT SNOW BAND HAS
BEEN JUST NORTH AND EAST OF KDLH SO FAR THIS MORNING WITH LIFR
CONDITIONS LIKELY IN THE SNOWBAND...BUT THE RUC AND NAM12 SHOW
BACKING LOW LEVEL WINDS AND LOW LEVEL CONVERGENCE INCREASING OVER
KDLH THIS AFTERNOON. SNOW SHOWERS MAY INCREASE IN INTENSITY THIS
AFTERNOON OVER KDLH.
THE INVERTED TROUGH WILL WEAKEN TONIGHT WITH FLOW BECOMING MORE
WEST-NORTHWEST. THIS CHANGE IN LOW LEVEL FLOW WILL ALSO ALLOW THE
LAKE EFFECT SNOW TO END.
&&
.PREV DISCUSSION... /ISSUED 301 AM CST SUN MAR 4 2012/
SHORT TERM...
TODAY THROUGH MONDAY AFTERNOON...
LAKE EFFECT SNOW SHOWERS ALONG THE NORTH SHORE TODAY FROM DULUTH
TO SILVER BAY WILL BE THE MAIN FOCUS IN THE SHORT TERM. A LAKE
EFFECT SNOW ADVISORY IS IN EFFECT UNTIL 4 PM THIS AFTERNOON FOR
THIS AREA.
A BROAD UPPER TROUGH IS POSITIONED OVER THE ERN CONUS WITH AN
UPPER RIDGE BUILDING IN ACROSS THE WEST COAST. AT THE SFC AN
INVERTED TROUGH REMAINS DRAPED ACROSS THE GREAT LAKES...EXTENDING
FROM LAKE ONTARIO THROUGH MICHIGAN AND BACK INTO WRN LAKE
SUPERIOR. A SFC HIGH IS SITUATED OVER NRN ONTARIO WITH A SECOND
NARROW SFC HIGH CUTTING THROUGH THE RED RIVER VALLEY AS THE NEXT
SYSTEM PREPARES TO MOVE THROUGH SRN MN FROM THE NRN ROCKIES. THE
EXTENSION OF THIS INVERTED TROUGH INTO THE NORTHLAND ALONG WITH
THE COMBINATION OF A PERSISTENT ELY FLOW FROM THE SFC HIGH TO THE
NORTH AND COLD AIR ALOFT HAS ALLOWED THE LOCALIZED LAKE
EFFECT SNOW SHOWERS TO CONTINUE THROUGH THE LAST 24-36 HOURS.
ATTM...IT APPEARS THIS SET UP WILL PERSIST THROUGH THIS MORNING
AND INTO THE MID AFTERNOON TODAY BEFORE THE WINDS SHIFT TO THE
WEST AND CUT OFF THE LES PROCESSES. LATEST NAM12 AND RUC13 BOTH
INDICATE THE LOW LEVEL E/NE WINDS...STEEP 0-3KM LAPSE
RATES...SATURATED BL AND 1000-900MB CONVERGENT CONDITIONS WILL
PERSIST THROUGH THE REST OF THE MORNING UNTIL AROUND 21/22Z. A
FAIRLY INTENSE LINE OF REGENERATIVE LE SNOW SHOWERS HAVE BEEN
INDICATED ON THE DLH RADAR FOR THE PAST 4-5 HOURS MAINLY
AROUND TWO HARBORS...AND IT APPEARS WILL CONTINUE FOR QUITE SOME
TIME. THERE IS SOME QUESTION AS TO WHETHER THIS BAND COULD VEER TO
THE NORTH TO AROUND SILVER BAY...OR TO THE SOUTH TO DULUTH...OR
EVEN IF ADDITIONAL SNOW BANDS COULD DEVELOP THROUGH THE HEAD OF
THE LAKE. GIVEN THE LATEST RADAR TRENDS AND FAVORABLE CONDITIONS
FOR LES TO PERSIST...WILL ISSUE A LAKE EFFECT SNOW ADVISORY FOR
SOUTHEAST ST. LOUIS COUNTY AND SOUTHERN LAKE COUNTY ALONG THE LAKE
SHORE UNTIL 4 PM. WILL LIKELY SEE 3 TO 5 INCHES IN THIS
AREA...WITH LOCALLY HIGHER AMOUNTS IN LOCATIONS THAT SEE A
PERSISTENT MDT/HVY SNOW BAND THIS MORNING. THE AREA AROUND TWO
HARBORS IS THE MOST LIKELY LOCATION FOR THE HEAVIEST SNOW. EVEN
THOUGH CARLTON COUNTY AND PARTS OF WEST DULUTH/HERMANTOWN ARE IN
THE ADVISORY...A GOOD PORTION OF THIS ZONE WILL ONLY SEE 1-2
INCHES AT MOST. THE MAIN AREA WE ARE CONCENTRATING ON IS FROM THE
NE SECTIONS OF DULUTH NEWD ALONG THE SHORE TO AROUND SLIVER BAY.
COULD SEE A FEW LIGHT SHOW SHOWERS LINGER OVER THE ARROWHEAD AND
NW WI TONIGHT...BUT WITH ONLY LIGHT ADDITIONAL ACCUMULATIONS
EXPECTED. THE SFC RIDGE AXIS SLIDES QUICKLY THROUGH THE REGION
TOMORROW AND ALLOWS CONDITIONS TO DRY OUT...SKIES TO CLEAR OFF
PARTIALLY AND TEMPERATURES TO WARM WELL INTO THE 30S.
THE NEXT WEAK SYSTEM SLIDES ACROSS THE NORTH LATE TOMORROW
AFTERNOON AND BRINGS ANOTHER CHANCE OF SNOW SHOWERS TO THE
BORDERLAND FROM INTL FALLS TO VIRGINIA TO GRAND MARAIS. ONLY LIGHT
ACCUMULATIONS ARE EXPECTED.
LONG TERM...
MONDAY NIGHT THROUGH SATURDAY...
THE MODELS ARE IN BETTER AGREEMENT THROUGH MUCH OF THE PERIOD.
WARM AIR WILL BE IN PLACE EARLY IN THE PERIOD. SOME LIGHT PRECIP
WILL BE POSSIBLE MONDAY NIGHT ACROSS THE FAR NORTH...WHICH WOULD
LIKELY FALL AS A LIGHT MIX. PERSISTENT WAA AND STRENGTHENING
INVERSION COULD LEAD TO BOTH SOME DRIZZLE AND MORE CLOUD COVER
THAN WE CURRENTLY HAVE IN THE GRIDS. AT THIS TIME...WE`LL KEEP
TUESDAY DRY AND CLOUD COVER AS PARTLY CLOUDY. A COLD FRONT WILL
MOVE THE NORTHLAND TUESDAY NIGHT INTO WEDNESDAY...WITH A CHANCE
FOR PRECIP BOTH AHEAD AND BEHIND THE BOUNDARY. WE ADDED A SLIGHT
CHANCE FOR LIGHT RAIN TUESDAY EVENING WITH 35-45KT SOUTHWEST WINDS
AT 850MB FORECAST. RAIN SHOULD BE THE MAIN PRECIP TYPE AHEAD OF
THE FRONT WITH WARM 850MB TEMPS FORECAST...TRANSITIONING TO MAINLY
SNOW WELL BEHIND THE FRONT. PRECIP AMOUNTS SHOULD BE LIGHT.
GFS/ECMWF DIFFER SOME ON THURSDAY WITH HOW FAR SOUTH THEY BRING A
SHORTWAVE TROUGH AND SURFACE LOW PRESSURE. WE WENT CLOSER TO THE
ECMWF AND HAVE A CHANCE FOR LIGHT SNOW. AGAIN WITH THIS
SYSTEM...PRECIP AMOUNTS LOOK LIGHT...WITH THE EXCEPTION OF
THURSDAY NIGHT/FRIDAY ALONG THE SOUTH SHORE WHICH COULD SEE SOME
BETTER SNOW ACCUMULATIONS DUE TO LAKE EFFECT PROCESSES.
NEXT WEEKEND LOOKS DRY WITH A SIGNIFICANT WARM UP FORECAST BY
BOTH THE GFS/ECMWF.
&&
.POINT TEMPS/POPS...
DLH 25 9 33 27 / 60 30 10 10
INL 24 5 35 29 / 20 10 40 20
BRD 28 11 37 29 / 30 10 10 10
HYR 28 7 35 27 / 30 20 10 10
ASX 26 10 35 28 / 40 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...LAKE EFFECT SNOW ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR
MNZ037.
LAKE EFFECT SNOW WARNING UNTIL 4 PM CST THIS AFTERNOON FOR
MNZ020.
WI...NONE.
&&
$$
SHORT TERM...TENTINGER
LONG TERM....MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
540 AM CST SUN MAR 4 2012
.UPDATE...
.AVIATION...
VFR IS GENERALLY EXPECTED ALL AREAS TODAY AND TONIGHT.
LOCAL MVFR CONDITIONS IN ISOLD SHRA/SHSN WILL CONTINUE THROUGH 00Z
TODAY AS A WARM FRONT MOVES EAST THROUGH NCNTL NEB AND IS REPLACED
BY A COLD FRONT MOVING THROUGH LATER THIS MORNING.
WINDS TODAY INCREASE TO 33030G45KT IN MANY AREAS AS A STRONG LOW
PRESSURE SYSTEM ACROSS WRN ND THIS MORNING DIVES SOUTH THROUGH THE
MISSOURI RIVER BASIN THROUGHOUT THE DAY. WINDS SUBSIDE BY 01Z THIS
EVENING.
&&
.PREV DISCUSSION... /ISSUED 349 AM CST SUN MAR 4 2012/
DISCUSSION...
FORECAST CHALLENGE OVER THE NEXT 48 HOURS DEALS WITH ADVISORY
CRITERIA WIND SPEEDS THIS AFTERNOON...THEN THE FOCUS SHIFTS TO THE
EXPECTED WARM UP FOR THE BEGINNING OF THE WORK WEEK AND ASSOCIATED
FIRE RISKS.
INHERITED WIND ADVISORY LOOKS TO BE IN GOOD SHAPE...WITH ONLY A FEW
MINOR MODIFICATIONS NEEDED AT THIS POINT IN TIME. WILL GO AHEAD AND
BEGIN THE WIND ADVISORY FOR OUR WESTERN COUNTIES WITH THIS FORECAST
ISSUANCE...AS CRITERIA LEVEL WIND SPEEDS HAVE ALREADY BEEN REPORTED
ACROSS THE WESTERN PANHANDLE EARLY THIS MORNING. WILL ALSO INCLUDE
WESTERN CHERRY AND SHERIDAN COUNTY IN THE ADVISORY AS RECENT HRRR
MODEL OUTPUT SUGGESTS THE POTENTIAL THERE FOR ADVISORY LEVEL WIND
GUSTS. OTHERWISE MODELS CONTINUE TO INDICATE STRONG UNIDIRECTIONAL
FLOW WITH DEEP MIXING THROUGH EARLY-TO-MID AFTERNOON TODAY. WITH
MIXING POTENTIAL AOA 800MB...MOMENTUM TRANSFER OF UP TO 60 KTS IS
POSSIBLE...WHICH WOULD LEAD TO SURFACE WIND GUSTS OF GREATER THAN 45
MPH EARLY THIS AFTERNOON ACROSS MUCH OF THE CWA. BY MID AFTERNOON
THE STRONGEST HEIGHT RISES AND MOMENTUM ALOFT WILL BE NORTH AND EAST
OF FORECAST AREA. THUS EXPECT WIND SPEEDS TO SUBSIDE RATHER QUICKLY
LATER THIS AFTERNOON...SUCH THAT THE ONGOING WIND ADVISORY MAY BE
CANCELED A FEW HOURS EARLY. BUT FOR NOW...WILL CONTINUE THE ONGOING
ADVISORY UNTIL 00Z TONIGHT.
NOT SURE WHAT TO MAKE OF THE CLIPPER TYPE SYSTEM CURRENTLY BRUSHING
OUR NORTHERN AND EASTERN ZONES. -SN HAS BEEN REPORTED AT BOTH KVTN
AND KANW EARLY THIS MORNING...HOWEVER SATURATION ELSEWHERE HAS BEEN
SLOW TO COMMENCE. THE HRRR CONTINUES TO PAINT LIGHT QPF ACROSS OUR
NORTHERN AND WESTERN ZONES THROUGH MID MORNING...NAM IS A BIT MORE
OPTIMISTIC AND DRIER. THE EURO AND TO SOME EXTENT THE GFS SEEM TO
WANT TO GENERATE LIGHT QPF ACROSS OUR WESTERN ZONES LATE THIS
MORNING. WITH THE STEEP LAPSE RATES...WEAK INSTABILITY AND FAVORABLE
UPPER LEVEL DYNAMICS IN PLACE...CANNOT ARGUE AGAINST THE POTENTIAL
OF A -SNSH OR -RASH THROUGH MID MORNING. HOWEVER SOUNDINGS INDICATE
MINIMAL LOW LEVEL MOISTURE AND THE FACT THAT CURRENT RADAR
OBSERVATIONS SUGGEST OTHERWISE...WILL LEAN TOWARD THE THE DRIER
SOLUTIONS...MAINLY THE NAM AND END THE MENTION OF PRECIPITATION
SHORTLY AFTER 15Z THIS MORNING. REVISIONS MAY BE NEEDED.
THE THREAT OF HEIGHTENED FIRE DANGER IS STILL A POSSIBILITY TODAY
ACROSS FAR SOUTHWESTERN PORTIONS OF THE CWA...HOWEVER RELATIVE
HUMIDITY VALUES ARE LOOKING SLIGHTLY BETTER THAN COMPARED WITH
PREVIOUS MODEL RUNS. LOW TO MID LEVEL MOISTURE HAS INCREASED
SLIGHTLY...AND EVEN WITH THE WARMER EXPECTED TEMPERATURES THIS
AFTERNOON...STILL LOOKING FOR MINIMUM RELATIVE HUMIDITY VALUES SOME
10 PERCENT OR GREATER ABOVE RED FLAG CRITERIA. AS OF NOW...FIRE
ZONES 210...219...AND FAR SOUTHWESTERN PORTIONS OF 204 HAVE THE
HIGHEST POTENTIAL OF EXTREME FIRE BEHAVIOR...BUT AGAIN NOT ENOUGH TO
WARRANT ANY FIRE HEADLINES. MONDAY AND ESPECIALLY TUESDAY MAY BE A
DIFFERENT STORY HOWEVER.
FOR THE START OF THE WORK WEEK...A FLAT UPPER LEVEL RIDGE WILL BUILD
ACROSS THE NORTHERN AND CENTRAL PLAINS LATE SUNDAY INTO MONDAY AND
USHER IN STRONG WARM AIR ADVECTION. MODEL GUIDANCE HINTS AT H925
TEMPERATURES ACROSS SOUTHWEST NEBRASKA AOA 15C BY MONDAY AFTERNOON.
FIRE CONCERNS MAY BE POSSIBLE ONCE AGAIN AS RELATIVE HUMIDITY VALUES
APPROACH CRITICAL LEVELS. GENERALLY TRENDED TOWARD THE DRIER ECMWF
GUIDANCE AS THE MODEL HAS PERFORMED REASONABLY WELL THE PAST COUPLE
DAYS WITH THE HANDLING OF THE RELATIVE HUMIDITY FIELDS. NOW ON
MONDAY AFTERNOON SOUTHERLY RETURN FLOW WILL STRENGTHEN AHEAD OF A
DEEPENING HIGH PLAINS SURFACE TROUGH. GENERALLY EMPLOYED THE USE OF
A GUIDANCE BLEND FOR WIND SPEEDS. THIS BLEND WOULD SUGGEST WIND
GUSTS OF LESS THAN 25 MPH /BELOW RED FLAG CRITERIA/.
H85 THERMAL RIDGE SHOULD BE MAXIMIZED ACROSS NORTH CENTRAL NEBRASKA
ON TUESDAY...WITH H85 TEMPERATURES WELL ABOVE 15C ACROSS MUCH OF THE
FORECAST AREA. THIS SHOULD TRANSLATE TO MAXIMUM HIGHS INTO THE MID
TO UPPER 60S ACROSS THE ENTIRE FORECAST AREA...WITH POSSIBLY LOW TO
MID 70S OVER THE HEAT PRONE AREAS OF THE CWA. AGAIN SOUTHERLY
RETURN FLOW LOOKS TO BECOME ESTABLISHED AS LOW PRESSURE DEEPENS IN
RESPONSE TO A DIGGING GREAT BASIN TROUGH. WITH EXPECTED HIGH
TEMPERATURES WELL ABOVE 70 DEGREES FAHRENHEIT ACROSS SOUTHWEST
NEBRASKA...FIRE ZONES 204...210...219 AND POSSIBLY SOUTHERN PORTIONS
OF 206 MAY EXPERIENCE RED FLAG CONDITIONS AS RH VALUES WILL FALL
BELOW 15 PERCENT AND WIND GUSTS WILL FLIRT WITH 25 MPH. A FIRE
WEATHER WATCH AND RED FLAG WARNINGS MAY BE NEEDED FOR TUESDAY.
CHANGES ARE IN STORE THEREAFTER AS A WEST COAST UPPER TROUGH
ADVANCES ON THE NORTHERN AND CENTRAL PLAINS. THE LONG RANGE
SOLUTIONS ALL AGREE THAT A STRONG COLD FRONT WILL ACCOMPANY THE
TROUGH AND BRING AN END TO THE PLEASANT WEATHER CONDITIONS. BY
MIDDAY WEDNESDAY...H85 TEMPERATURES APPEAR TO RUN SOME 15 TO 20C
COOLER THAN THAT TO BE OBSERVED ON TUESDAY. PRECIPITATION CHANCES
ARE BECOMING LESS CERTAIN MID WEEK AS THE TROUGH CONTINUES TO TREND
SOUTH. THE CONSENSUS AND ENSEMBLES CONTINUE TO SUPPORT A SPLIT
PATTERN WHICH WOULD FAVOR A DRY FORECAST FOR MUCH OF THE CWA AS THE
SYSTEM MEANDERS ACROSS THE SOUTHWEST. THE EXTENDED PROCEDURE
GENERALLY CUT BACK POPS ON WEDNESDAY...WHICH LOOKS PLAUSIBLE AT THIS
POINT IN TIME...THUS NO MAJOR CHANGES WERE MADE. OTHERWISE WITH A
SPLIT FLOW REGIME THAT TRANSITIONS TO GENERAL RIDGING ALOFT BY WEEKS
END...A DRY FORECAST WITH NEAR TO SLIGHTLY ABOVE AVERAGE
TEMPERATURES APPEAR REASONABLE AT THIS POINT IN TIME FOR THE
EXTENDED.
AVIATION...
VFR IS GENERALLY EXPECTED ALL AREAS TODAY AND TONIGHT.
LOCAL MVFR CONDITIONS IN ISOLD SHRA/SHSN WILL CONTINUE THROUGH 00Z
TODAY AS A WARM FRONT MOVES EAST THROUGH NCNTL NEB AND IS REPLACED
BY A COLD FRONT MOVING THROUGH LATER THIS MORNING.
WINDS TODAY INCREASE TO 33030G45 IN MANY AREAS AS A STRONG LOW
PRESSURE SYSTEM ACROSS WRN ND THIS MORNING DIVES SOUTH THROUGH THE
MISSOURI RIVER BASIN THROUGHOUT THE DAY. WINDS SUBSIDE BY 01Z THIS
EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR NEZ004-022-023-
035-056>058-069-094.
WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ005>010-024>029-036>038-059-070-071.
&&
$$
SHORT TERM/EXTENDED...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1026 AM EST SUN MAR 4 2012
.SYNOPSIS...
A SECONDARY COLD FRONT WILL DROP SOUTH ACROSS THE REGION TODAY WITH
SCATTERED SNOW SHOWERS AND SOME LIMITED LAKE EFFECT SNOW EAST AND
SOUTHEAST OF THE LAKES AS TEMPERATURES DROP TO BELOW AVERAGE. SNOW
SHOWERS WILL GRADUALLY DIMINISH THIS EVENING WITH LAKE EFFECT SNOW
LINGERING SOUTHEAST OF THE LAKES INTO MONDAY MORNING. HIGH PRESSURE
WILL THEN BUILD INTO THE REGION MONDAY NIGHT FOLLOWED BY A RETURN TO
MUCH ABOVE AVERAGE TEMPERATURES BY THE MIDDLE OF THE WEEK. THE NEXT
CHANCE OF RAIN WILL ARRIVE THURSDAY WITH THE APPROACH OF A COLD
FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH 1000 AM...RADAR SHOWS SNOW SHOWERS ENHANCING JUST SOUTH OF
LAKE ONTARIO FROM NIAGARA TO MONROE COUNTIES. VISIBLE SATELLITE
SHOWS A MOISTURE TIE IN BACK TO LAKE HURON...WITH MOISTURE BEING
FUNNELED ALONG THE FRONTAL BOUNDARY...THEN ENHANCING AS IT REACHED
LAKE ONTARIO. BECAUSE IT IS THE FRONT PROVIDING THE FOCUS...FEEL
THE HRRR AND OTHER HIGHER RESOLUTION MODELS SUCH AS THE NAM/RGEM
SHOULD BE ABLE TO HANDLE THE PROGRESSION OF THIS BAND. ALL THESE
MODELS DROP THIS FRONT (AND ASSOCIATED QPF) SOUTHWARD TODAY.
INTENSITY MAY VARY...BUT FOR NOW SNOW SHOWERS ARE FAIRLY INTENSE
JUST SOUTH OF LAKE ONTARIO...WHERE A QUICK INCH OR TWO OF SNOW MAY
FALL. AFTER THIS...EXPECT THE BAND TO WEAKEN AS IT DROPS
SOUTH...BUT STILL BRING A DECENT BURST OF SNOW TO AS IT DROPS
SOUTHWARD TODAY.
MEANWHILE...SNOW SHOWERS CONTINUE ACROSS THE BOSTON HILLS AND
WESTERN PORTIONS OF THE SOUTHERN TIER...THOUGHT THESE ARE LIKELY
BEING TEMPORARILY ENHANCED BY ANOTHER TIE IN OF MOISTURE FROM LAKE
HURON ALSO SHOWN ON VISIBLE SATELLITE. SNOW SHOWERS IN THESE
LOCATIONS WILL VARY IN INTENSITY...LIKELY DIMINISHING FOR A
WHILE...BUT THEN PICKING UP AGAIN AS THE FRONTAL BOUNDARY REACHES
THE AREA LATER THIS AFTERNOON. EXPECT 2 TO 3 INCHES TODAY IN THESE
TYPICALLY FAVORABLE SNOW BELTS EAST OF LAKE ERIE.
STEADY SNOW SHOWERS HAVE EXITED EAST OF LAKE ONTARIO...WITH MORE
GENERIC SCATTERED SNOW SHOWERS IN THE REGION. EXPECT THIS TO
CONTINUE...BUT WITH ONLY LIGHT ADDITIONAL ACCUMULATIONS THROUGH
MOST OF THE AFTERNOON HOURS. THE ONE THING TO WATCH HERE IS FOR A
LAKE EFFECT BAND TO RE-DEVELOP IN THE NW FLOW...AND TO SET UP
ACROSS WAYNE/N CAYUGA COUNTIES LATE AFTERNOON.
OFF LAKE ERIE TONIGHT...NORTHWEST FLOW WILL MAINTAIN A FEW SNOW
SHOWERS ACROSS THE CHAUTAUQUA RIDGE. THERE MAY BE A BRIEF WINDOW
THIS EVENING WHERE SOME UPSTREAM CONNECTION TRIES TO DEVELOP FROM
LAKE HURON...BUT THIS WILL BE SHORT LIVED AS HIGH PRESSURE
BUILDING OVER THE CENTRAL LAKES QUICKLY SHUTS OFF ANY UPSTREAM
LAKE EFFECT. EXPECT ADDITIONAL AMOUNTS OF 2-3 INCHES IN PERSISTENT
BANDS CENTERED ON SKI COUNTRY.
OFF LAKE ONTARIO TONIGHT...LAKE EFFECT WILL INITIALLY BE VERY
DISORGANIZED IN NORTHWEST FLOW DUE TO THE LINGERING EFFECTS OF
DAYTIME HEATING. BY MID TO LATE EVENING EXPECT A BROKEN BAND TO
CONCENTRATE TO THE SOUTHEAST OF THE LAKE ACROSS WAYNE...N CAYUGA
AND FAR SOUTHERN OSWEGO COUNTIES. SOME OF THIS MAY CLIP THE
NORTHERN AND EASTERN SUBURBS OF ROCHESTER AS WELL. MAY SEE ANOTHER
2-3 INCHES LOCALLY FROM THIS OVERNIGHT.
OUTSIDE OF LAKE EFFECT AREAS...SCATTERED SNOW SHOWERS MAY PRODUCE
ANOTHER DUSTING OF ACCUMULATION THIS EVENING BEFORE ENDING
OVERNIGHT. SNOW SHOWERS MAY LINGER THROUGH THE NIGHT ACROSS THE
HIGHER TERRAIN EAST OF LAKE ONTARIO AS A POCKET OF DEEPER MOISTURE
LINGERS BEHIND THE DEPARTING LOW. MODIFIED ARCTIC AIR WILL SEND
TEMPS BELOW AVERAGE TONIGHT...ALTHOUGH MOS TEMPS LOOK A LITTLE TOO
COLD GIVEN EXTENSIVE LAKE EFFECT CLOUDS. EXPECT LOWS GENERALLY IN
THE MID TEENS...WITH SINGLE DIGITS EAST OF LAKE ONTARIO.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
ON MONDAY...THE LAKE SNOWS EAST-SOUTHEAST OF THE LAKES WILL
GRADUALLY DIMINISH DUE TO BOTH DIURNAL INFLUENCES AND RIDGING
BUILDING EAST FROM THE CENTRAL GREAT LAKES...WHICH WILL PROVIDE MUCH
DRIER AIR AND INCREASING AMOUNTS OF SUBSIDENCE. EXPECT ONLY A FEW
LEFTOVER LIGHT SNOW SHOWERS AND/OR FLURRIES TO BE LEFTOVER BY MONDAY
EVENING...WITH THIS ACTIVITY THEN FALLING APART COMPLETELY DURING
MONDAY NIGHT AS THE AXIS OF THE LOW LEVEL RIDGE MOVES OVERHEAD.
ELSEWHERE...CONDITIONS WILL LARGELY BE JUST DRY AND COLD...WITH WELL
BELOW NORMAL TEMPERATURES CONTINUING GIVEN THE RATHER CHILLY AIRMASS
THAT WILL BE IN PLACE AT THE LOW LEVELS. EXPECT HIGHS TO BE ONLY IN
THE LOWER TO MID 20S ON MONDAY...WITH WIDESPREAD LOWS BETWEEN 10 AND
15 THEN FOLLOWING FOR MONDAY NIGHT AS THE RIDGE AXIS CRESTS OVERHEAD
AND PROVIDES GOOD CONDITIONS FOR RADIATIONAL COOLING. THE NORTH
COUNTRY WILL BE EVEN COLDER...WITH LOWS FALLING TO AROUND ZERO OR
PERHAPS EVEN SLIGHTLY BELOW ACROSS MOST OF JEFFERSON AND LEWIS
COUNTIES.
AFTER THAT...THE SURFACE RIDGE WILL SLIDE EAST TO THE NEW ENGLAND
COAST AND THEN OFFSHORE TUESDAY AND WEDNESDAY...WHILE BROAD UPPER
RIDGING BUILDS EAST ACROSS THE GREAT LAKES AND NORTHEAST. ALL OF
THIS WILL RESULT IN A DEEPENING SOUTHWESTERLY FLOW OF PROGRESSIVELY
MILDER AIR OVERSPREADING THE AREA DURING TUESDAY...THEN CONTINUING
RIGHT THROUGH WEDNESDAY. WHILE THIS WARM ADVECTION PATTERN WILL
RESULT IN SOME MID AND UPPER LEVEL CLOUDS PASSING ACROSS THE AREA
FROM TIME TO TIME...BOTH DAYS STILL LOOK TO REMAIN DRY WITH THE BEST
LIFT AND MOISTURE REMAINING WELL TO OUR NORTH AND WEST IN
ASSOCIATION WITH A SURFACE WARM FRONT LIFTING ACROSS THE
WESTERN/CENTRAL LAKES AND INTO ONTARIO PROVINCE.
UNDER THIS WARM AIR ADVECTION REGIME...925 MB TEMPS WILL STEADILY
CLIMB THROUGH MIDWEEK...EVENTUALLY REACHING THE +4C T0 +9C RANGE BY
WEDNESDAY AFTERNOON. COUPLED WITH A GOOD SOUTHWESTERLY LOW LEVEL
FLOW AND AT LEAST SOME PARTIAL SUNSHINE...THIS WILL ALLOW FOR
DAYTIME HIGH TEMPERATURES TO REBOUND BACK TO MORE NORMAL LEVELS IN
THE MID 30S TO LOWER 40S ON TUESDAY...BEFORE REALLY SOARING INTO THE
MID AND UPPER 50S ACROSS MUCH OF THE AREA ON WEDNESDAY. IN FACT...
THE NORMALLY WARM SPOTS OF THE GENESEE VALLEY/FINGER LAKES MAY EVEN
REACH OR BREAK 60F ON WEDNESDAY.
THE MILD WEATHER WILL THEN CONTINUE THROUGH WEDNESDAY NIGHT AS THE
AFOREMENTIONED SOUTHWESTERLY FLOW REMAINS ANCHORED ACROSS OUR
AREA...IN ADVANCE OF A COLD FRONT SLOWLY APPROACHING FROM THE
CENTRAL GREAT LAKES. WHILE THIS FEATURE WILL BRING A NORTHWEST TO
SOUTHEAST INCREASE IN CLOUD COVER AS IT PUSHES INTO SOUTHERN ONTARIO
LATER IN THE NIGHT...BOTH THE 00Z GFS/ECMWF NOW SUGGEST THAT IT WILL
REMAIN JUST FAR ENOUGH TO OUR NORTH FOR OUR AREA TO REMAIN LARGELY
DRY THROUGH THE NIGHT...HENCE WILL KEEP POPS AT THE SLIGHT CHANCE OR
LOWER FOR WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
WITH THE 00Z GFS/GEM/ECMWF NOW IN MUCH BETTER AGREEMENT THAT THE
AFOREMENTIONED COLD FRONT WILL SLOWLY OOZE ACROSS OUR AREA THURSDAY
AND THURSDAY NIGHT AS IT BECOMES ORIENTED INCREASINGLY PARALLEL TO
THE LARGE-SCALE UPPER LEVEL FLOW...WILL FOCUS CHANCE POPS FOR THE
FRONTAL PASSAGE ON THESE TWO PERIODS...ALONG WITH SOMEWHAT COOLER
BUT STILL ABOVE NORMAL TEMPS ON THURSDAY GIVEN THE INCREASED AMOUNT
OF CLOUD COVER AND PRECIP.
AFTER THAT...THE VARIOUS GUIDANCE PACKAGES DIVERGE AGAIN SOMEWHAT
WITH RESPECT TO HOW QUICKLY THE FRONT DEPARTS OUR AREA TO THE
SOUTHEAST...AS WELL AS IN HOW FAST SIGNIFICANTLY COLDER/DRIER AIR
SUBSEQUENTLY OVERSPREADS OUR AREA FROM THE NORTHWEST FOLLOWING THE
FRONTAL PASSAGE. ALL OF THIS APPEARS TO ULTIMATELY BE TIED TO THE
STRENGTH AND DEPTH OF THE UPPER TROUGH PASSING ACROSS ONTARIO AND
QUEBEC LATE IN THE WEEK...WITH A FASTER/FLATTER TROUGH ALLOWING FOR
A FASTER PROGRESSION ALA THE GFS...AND A SLOWER/SLIGHTLY MORE
AMPLIFIED TROUGH RESULTING IN A SLOWER EVOLUTION MORE ALONG THE
LINES OF THE ECMWF/GEM. AT THIS DISTANT JUNCTURE...WILL JUST OPT TO
KEEP THINGS SIMPLE AND PORTRAY A GENERAL NORTHWEST-SOUTHEAST
DECREASE IN CHANCE POPS ON FRIDAY FOLLOWING THE FRONTAL PASSAGE...
THEN A RETURN TO SEASONABLY COLDER AND DRY CONDITIONS FOR SATURDAY
WITH THE COLDER AIRMASS PRESENTLY APPEARING TO BE TOO DRY TO SUPPORT
MUCH LAKE EFFECT.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
EXPECT MAINLY VFR/MVFR CONDITIONS TODAY...WITH PERIODS OF IFR OR
LOWER IN SNOW SHOWERS. MOST SIGNIFICANT BAND WILL DROP SOUTHWARD
AND WEAKEN LATE MORNING INTO THIS AFTERNOON...TEMPORARILY IMPACTED
IAG/ROC/BUF. EXPECT IMPROVING CONDITIONS BEHIND THIS.
THE SNOW SHOWERS WILL GRADUALLY DIMINISH TONIGHT...PERSISTING THE
LONGEST SOUTHEAST OF THE LAKES IN SOME LINGERING LAKE EFFECT. A MIX
OF VFR AND MVFR CIGS WILL CONTINUE WITH MVFR MORE PREVALENT ACROSS
THE HIGHER TERRAIN.
OUTLOOK...
MONDAY...VFR/MVFR WITH SCATTERED SNOW SHOWERS.
TUESDAY AND WEDNESDAY...VFR.
THURSDAY...MVFR/VFR. A CHANCE OF SHOWERS.
&&
.MARINE...
WINDS HAVE DIMINISHED TO BELOW GALE EARLY THIS MORNING AS THE STRONG
LOW PRESSURE SYSTEM CONTINUES TO PULL AWAY INTO ATLANTIC CANADA. A
SECONDARY COLD FRONT WILL DROP SOUTH ACROSS THE LOWER LAKES TODAY
WITH MODERATE WESTERLIES BECOMING NORTHWEST. THIS WILL MAINTAIN
SMALL CRAFT ADVISORY CONDITIONS THROUGH THIS EVENING ON BOTH LAKES
ERIE AND ONTARIO. WAVES WILL BEGIN TO COME DOWN LATER THIS EVENING
IN MOST LOCATIONS...EXCEPT AT THE SOUTHEAST CORNER OF LAKE ONTARIO
FROM ABOUT ROCHESTER TO MEXICO BAY WHERE FAVORABLE FETCH WILL
MAINTAIN SMALL CRAFT ADVISORY CONDITIONS THROUGH MONDAY IN NORTHWEST
FLOW. HIGH PRESSURE WILL BUILD OVER THE LOWER LAKES MONDAY NIGHT
WITH WINDS BECOMING LIGHT.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 10 PM EST MONDAY FOR
LOZ043-044.
SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LOZ042-045.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL/HITCHCOCK
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
920 AM CST SUN MAR 4 2012
.SHORT TERM...TODAY
920 AM CST SUN MAR 4 2012
A SURFACE AND 925 MB INVERTED TROUGH IS LOCATED ACROSS WESTERN
WISCONSIN. THIS SYSTEM EXTENDS FROM JUST EAST OF EAU CLAIRE TO
RICHLAND CENTER. WEAK SURFACE CONVERGENCE IS INDICATED IN THE WIND
DATA. THIS SYSTEM IS CURRENTLY PRODUCING A BAND OF LIGHT
SNOW...AND THE LATEST HRRR AND NAM/WRF SUGGEST THAT THIS SNOW WILL
CONTINUE THROUGH THE DAY. SNOW TOTALS WILL BE UP TO AN INCH.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
239 AM CST SUN MAR 4 2012
THE WARM AIR WILL GET PUSHED EAST OF THE AREA STARTING WEDNESDAY
AS A COLD FRONT WORKS ACROSS THE REGION. THE LATEST SET OF LONG
RANGE MODELS SHOW THE FRONT NEAR THE EASTERN EDGE OF THE FORECAST
AREA BY THE END OF WEDNESDAY. A BAND OF PRECIPITATION IS EXPECTED
TO OCCUR ALONG AND BEHIND THE FRONT AS THE UPPER LEVEL TROUGH WILL
BE COMING THROUGH WITH A POSITIVE TILT. MOST OF THIS PRECIPITATION
WILL FALL AS RAIN UNTIL ENOUGH COLD AIR STARTS TO COME IN BEHIND
THE FRONT FOR A CHANGE OVER TO LIGHT SNOW.
&&
.AVIATION...TODAY AND TONIGHT
548 AM CST SUN MAR 4 2012
CYCLONIC FLOW AND SURFACE TROUGH OVER WISCONSIN KEEPING MVFR TO VFR
CEILINGS ALONG AND EAST OF THE MISSISSIPPI RIVER ALONG WITH AREAS OF
SNOW THAT ARE PRODUCING MVFR RESTRICTIONS DUE TO VISIBILITIES.
ALTHOUGH EXPECT CONDITIONS TO IMPROVE AT KLSE THIS MORNING...
CLOUDS AND SNOW SHOWERS OR FLURRIES COULD LINGER UNTIL TROUGH SWINGS
THROUGH.
FURTHER WEST SURFACE RIDGE HAS PRODUCED CLEARING AREA WITH NO
IMPACTS TO AVIATION. APPROACHING SHORT WAVE TROUGH OUT OF
NORTHERN DAKOTAS WILL BRING INCREASE IN CLOUDS THROUGH THE DAY BUT
EXPECT VFR CONDITIONS TO HOLD AT LEAST THROUGH MID AFTERNOON. BULK
OF PRECIPITATION WITH THIS FEATURE SHOULD STAY WEST AND SOUTH OF TAF
SITES BUT LOWER CONFIDENCE EXISTS IN HOW LOW CEILINGS WILL GET ON
NORTH EDGE AND HOW LONG THESE CLOUDS WOULD HOLD ON UNTIL THEY EXIT
MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
548 AM CST SUN MAR 4 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....04
AVIATION.....SHEA
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
241 PM MST SUN MAR 4 2012
.SHORT TERM...THE CROSS STATE PRESSURE GRADIENT CONTINUES TO
RELAX WITH THE EAGLE-DENVER SFC P.G. FALLING BELOW 7 MBS IN THE
PAST HOUR. WHEREAS THE STRONG NORTHWEST FLOW ALOFT HAS YET TO
DECREASE AS PER AREA PROFILERS AND RUC WIND FIELDS. THAT SAID...
SFC WIND SPEEDS CONTINUE TO DECREASE...EXCEPT UP AGAINST THE
FOOTHILLS AND HIGHER AREAS NORTH OF FORT COLLINS NEAR THE WYOMING
BORDER WHERE WESTERLY WINDS STILL GUSTING 35-45 MPH. WIND SPEEDS
SHOULD DECREASE IN THESE AREAS AS WELL DURING THE NEXT FEW HOURS
ACCORDING TO MODEL GUIDANCE. WINDS SHOULD ASSUME THEIR USUAL
DRAINAGE PATTERN NOT TOO LONG AFTER SUNSET...EXCEPT NEAR THE
FOOTHILLS WHERE AN ENHANCED DRAINAGE FLOW IS LIKELY TO PERSIST
OVERNIGHT. DURING THE NEXT 24 HOURS...MODELS INDICATE A 1-2C
WARMUP AT 700MB AND LOW RHS THROUGHOUT THE COLUMN OVER NORTHEAST
COLORADO. THEREFORE PLENTY OF SUNSHINE AND WARMER SFC TEMPERATURES
AREAWIDE. AND WITH A WEAKER PRES GRAD ACROSS THE AREA...WINDS WILL
BE MUCH LIGHTER...EXCEPT PERHAPS NEAR THE FOOTHILLS WHERE WE COULD
SEE OCCASIONAL GUSTS TO 30 MPH.
.LONG TERM...FLAT RIDGE ACROSS COLORADO ON MONDAY NIGHT WITH FAST
WESTERLY FLOW...WILL SHIFT MORE SOUTHWESTERLY ON TUESDAY. THIS IN
REPSONSE TO DEEPENING TROF OVER THE GREAT BASIN THROUGH TUESDAY
NIGHT. VERY DRY AIRMASS IN PLACE MONDAY NIGHT AND TUESDAY WITH
MAINLY CLEAR SKIES. CROSS SECTIONS SHOW CROSS BARRIER FLOW OF
30-40KT SO CONTINUED GUSTY WINDS. SOME OF THIS WIND WILL MIX DOWN
OVER THE PLAINS TUESDAY WITH GUSTY SOUTHWEST WINDS MIXING DOWN.
THE STRONGEST WINDS ARE EXPECTED WHERE THERE IS STILL SOME SNOW
COVER SO BIT COOLER AND BORDERLINE RH LVLS SO NO FIRE HILITES
NEEDED. MUCH ABOVE NORMAL TEMPERATURES WILL READINGS WELL INTO THE
60S OVER ALL THE PLAINS.
BIGGER CONCERN TURNS TO THE MID WEEK WITH THE GREAT BASIN UPPER
LOW DEVELOPMENT AND HOW IT WILL EFFECT COLORADO. MODELS FAIRLY
CONSISTENT IN BRINGING IN INITIAL COLD FRONT LATE TUESDAY NIGHT
WITH COLDER AIRMASS IN PLACE FOR WEDNESDAY. THE PROBLEM IS THE
MODELS ARE QUITE VARIED ON WHERE THE LOW GOES NEXT. THE EUROPEAN
KEEPS THE LOW OVER ARIZONA THROUGH THURSDAY BEFORE MOVING IT INTO
NEW MEXICO ON FRIDAY THEN SWINGS IT INTO COLORADO ON SATURDAY. THE
GFS ON THE OTHER HAND MOVES THE LOW INTO 4 CORNERS REGION LATE
WEDNESDAY BEFORE SLOWLY MOVING IT INTO SW KANSAS BY FRIDAY AND
THEN IT SITS AND SITS THORUGH MUCH OF THE WEEKEND. NOT SURE HOW
MUCH MOISTURE IS GOING TO BE AVAILABLE SO FOR NOW JUST KEEP OUR
LOW POPS AND EXTEND THROUGH MUCH OF THURSDAY WITH THE SLOWER
MOVEMENT.
&&
.AVIATION...WEST WINDS 10-20KTS AT DIA AND APA AIRPORTS...AND
15-30KTS AT BJC NEAR T HE FOOTHILLS WILL CONTINUE TO WEAKEN FOR
THE REMAINDER OF THE AFTERNOON. WINDS WILL GO DRAINAGE 6-12KTS
AFTER 01Z...EXCEPT AT BJC WHERE WE COULD SEE WEST-SOUTHWEST
WINDS OF 12-22KTS FOR THE NEXT 24 HOURS. OTHERWISE CLEAR/MOSTLY
CLEAR SKIES AND VFR CONDITIONS EXPECTED IN THE DENVER AREA FOR
NEXT 24 HOURS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....ENTREKIN
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1131 AM CST SUN MAR 4 2012
.DISCUSSION...
ISSUED 1026 AM CST SUN MAR 4 2012
CLIPPER SYSTEM CURRENTLY CENTERED IN EASTERN SOUTH DAKOTA.
REGIONAL RADAR MOSAICS SHOWING ECHOES EXTENDING ALL THE WAY INTO
SOUTHEAST IOWA...BUT SURFACE OBSERVATIONS SHOWING LIGHT SNOW ONLY
TO ABOUT DES MOINES. 12Z HRRR IS A BIT FASTER THAN THE NAM IN
SPREADING PRECIPITATION INTO WEST CENTRAL ILLINOIS THIS
AFTERNOON...BUT BOTH AGREE THAT AREAS AROUND CHAMPAIGN AND
DANVILLE WILL LIKELY REMAIN DRY UNTIL CLOSER TO SUNSET.
PRECIPITATION TYPE REMAINS A CONCERN. LARGELY AM EXPECTING SNOW...
WITH PERHAPS A BIT OF RAIN MIXED IN INITIALLY BEFORE EVAPORATIVE
COOLING RAPIDLY TAKES PLACE. THE SOUTHEAST CWA IS THE BIGGEST
QUESTION MARK. AFTER LOOKING AT FORECAST SOUNDINGS...HAVE TRENDED
TO RAIN OR SNOW IN THE GRIDS SOUTH OF I-70 FOR THIS AFTERNOON. WILL
NEED TO WATCH TEMPERATURES CLOSELY...DUE TO THE EXPANSIVE SUNSHINE
OCCURRING THIS MORNING...AS IT MAY END UP BEING MORE RAIN THAN
SNOW DURING THE DAYLIGHT IN THAT AREA.
UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 1130 AM CST SUN MAR 4 2012
MAIN FOCUS WITH THIS TAF SET IS WITH DEVELOPMENT OF SNOW LATER
THIS AFTERNOON...AND ASSOCIATED LOWER CEILINGS/VISIBILITIES.
CURRENT THINKING REMAINS THAT KSPI WILL BE MOST IMPACTED...
BEGINNING AROUND 20-21Z. UPSTREAM OBSERVATIONS OVER NORTHWEST
IOWA AND SOUTHWEST MINNESOTA SHOWING VISIBLITIES BELOW A MILE IN
THE HEAVIER SNOW BANDS...WITH RUC/HRRR SHOWING POTENTIAL
VISIBILITIES BELOW 2 MILES CONTINUING THROUGH JUST PAST 00Z AS FAR
SOUTHEAST AS KSPI. WILL LIKELY SEE CEILINGS FALL AS LOW AS 1000
FEET IN THE HEAVIER BANDS. EASTERN TAF SITES FROM KPIA-KCMI WILL
LIKELY BE MORE ON THE FRINGES OF THE SNOW BANDS...BUT PERIODS OF
VISIBILITIES 3-4SM ARE STILL LIKELY THERE. SHOULD SEE THE
PRECIPITATION OUT OF THE TAF SITES BY ABOUT 04Z. MOST LOCATIONS
WILL SEE CEILINGS RISE TO VFR RANGE BY ABOUT 09Z...BEFORE CLOUDS
SCATTER OUT.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 313 AM CST SUN MAR 4 2012
RIDGING OVER THE WESTERN HALF OF THE CONUS THIS MORNING AS AN UPPER
TROF IS A LITTLE SLOW TO PROGRESS OUT OF THE MIDWEST...AND WILL
REMAIN IN PLACE AS A CLIPPER SYSTEM PUSHES OUT OF THE CANADIAN
ROCKIES DOWN INTO THE SYNOPTIC TROF TODAY AND TONIGHT BRINGING SNOW
CHANCES FOR MUCH OF THE CWA...WITH THE HIGHER ACCUMULATIONS EXPECTED
SOUTHWEST OF A LINE FROM PEORIA TO PARIS. MODELS ARE IN PRETTY GOOD
AGREEMENT OVERALL THROUGH MIDWEEK. ISSUES IN THE FORECAST CROP UP IN
THE EXTENDED WHEN ANOTHER TROF/LOW PRESSURE SYSTEM MOVE OUT OF THE
ROCKIES AND SRN PLAINS...AND UP THE OHIO RIVER VALLEY. PREVIOUS
MODEL RUNS HAVE HAD SOME SIGNIFICANT ISSUES DISCERNING THE BEHAVIOR
ULTIMATELY OF THE UPPER LOW...WITH THE GFS MOST NOTABLY CLOSING OFF
THE LOW AND STALLING A FRONTAL BOUNDARY FROM THE MID MISS RIVER
VALLEY UP INTO THE APPALACHIANS. ECMWF WAS MORE PROGRESSIVE OVERALL
IN PUSHING THE SYSTEM OUT QUICKLY. HOWEVER...THIS MODEL RUN BRINGS
THE ECMWF IN LINE WITH A CLOSED OFF LOW OVER THE SRN HALF OF THE
CONUS. NOT WILLING TO JUMP ON THE NEW RUN JUST YET...BUT WILL PRIME
THE FORECAST FOR A FEW ADJUSTMENTS IN THE LATTER HALF OF THE WORK
WEEK.
SHORT TERM...TODAY AND TONIGHT...
A QUICK CLIPPER SYSTEM IS PUSHING INTO THE MIDWEST THIS
MORNING/AFTERNOON...BRINGING SNOW AFTER NOON AND THROUGH MIDNIGHT.
PRECIP MAY START OUT AS RAIN IN THE EARLY AFTERNOON IN THE SWRN HALF
OF THE STATE...BUT THERMAL PROFILES QUICKLY MOVE OVER TO ALL SNOW IN
BOTH THE GFS AND THE NAM. 06Z HPC QPF PUTS THE FORECAST IN EXCESS OF
THE 2 INCH RANGE...BUT WITH SOME RAIN EXPECTED EARLY AND A SLIGHT
ADJUSTMENT TO THE QPF IN THE OVERNIGHT...BRINGS THE SNOW BACK TO A
1-2 INCH SCENARIO. TEMPS SIGNIFICANTLY COOLER NOW WITH THE SYSTEM
OVERALL. ABOVE FREEZING TEMPS BRIEFLY STICK AROUND IN THE EARLY
AFTERNOON HOURS PRIOR TO 22Z-00Z BEFORE EVAPORATIVE COOLING AND
RATHER QUICK SATURATION OF THE COLUMN SHOULD HELP TO SWITCH MOST OF
THE PRECIP OVER TO SNOWFALL. SNOW SHOULD BE WRAPPING UP JUST PRIOR
TO MIDNIGHT AS THE CLIPPER MOVES OUT INTO THE LARGER SCALE TROF AND
EXITS THE REGION.
LONG TERM...TOMORROW THROUGH SATURDAY...
WARMING TREND DELAYED A BIT MONDAY...WITH HIGH PRESSURE BUILDING
INTO THE MIDWEST AND ERN HALF OF THE CONUS. HOWEVER...TUES AND WED
LIKELY TO SEE TEMPS AROUND AND ABOVE 60 WITH PLENTY OF SOUTHERLY
WINDS AND LLVL WAA KICKING IN IN THE OVERNIGHT HOURS MON NIGHT. WINDY
CONDITIONS PREVAIL FOR TUESDAY AS THE MIDWEST GETS CAUGHT BETWEEN A
STUBBORN RIDGE OVER THE ATLANTIC STATES AND ANOTHER VIGOROUS WAVE
DIGGING IN OVER THE ROCKIES. AN ADVANCING COLD FRONT BRINGS PRECIP
TO THE REGION WITH THE INITIAL LARGE TROF. PRECIP...RAIN OR
SNOW...WED NIGHT THROUGH THURSDAY NIGHT. KEEPING FRIDAY POPS AWAY
STILL...BECAUSE THE MODELS HAVE PREVIOUSLY BEEN IN CONFLICT OVER ONE
POINT. THE GFS CUTS OFF THE 500 MB LOW...PUSHING A WARM FRONTAL
FEATURE INTO THE OHIO RIVER VALLEY ON FRIDAY. HOWEVER...THE MORE
PROGRESSIVE ECMWF HAS BEEN EXITING THE SYSTEM ALTOGETHER...NEVER
FORMING THE CUT OFF 500 MB LOW. HOWEVER...THE 00Z RUN SEEMS TO BE
GOING THE WAY OF THE GFS. NEXT ISSUE WILL BE A MATTER OF HOW FAR
NORTH ANY WARM FRONT ACTUALLY SETS UP WITH A LINGERING CUT OFF LOW
IN THE SW.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1028 AM CST SUN MAR 4 2012
.DISCUSSION...
ISSUED 1026 AM CST SUN MAR 4 2012
CLIPPER SYSTEM CURRENTLY CENTERED IN EASTERN SOUTH DAKOTA.
REGIONAL RADAR MOSAICS SHOWING ECHOES EXTENDING ALL THE WAY INTO
SOUTHEAST IOWA...BUT SURFACE OBSERVATIONS SHOWING LIGHT SNOW ONLY
TO ABOUT DES MOINES. 12Z HRRR IS A BIT FASTER THAN THE NAM IN
SPREADING PRECIPITATION INTO WEST CENTRAL ILLINOIS THIS
AFTERNOON...BUT BOTH AGREE THAT AREAS AROUND CHAMPAIGN AND
DANVILLE WILL LIKELY REMAIN DRY UNTIL CLOSER TO SUNSET.
PRECIPITATION TYPE REMAINS A CONCERN. LARGELY AM EXPECTING SNOW...
WITH PERHAPS A BIT OF RAIN MIXED IN INITIALLY BEFORE EVAPORATIVE
COOLING RAPIDLY TAKES PLACE. THE SOUTHEAST CWA IS THE BIGGEST
QUESTION MARK. AFTER LOOKING AT FORECAST SOUNDINGS...HAVE TRENDED
TO RAIN OR SNOW IN THE GRIDS SOUTH OF I-70 FOR THIS AFTERNOON. WILL
NEED TO WATCH TEMPERATURES CLOSELY...DUE TO THE EXPANSIVE SUNSHINE
OCCURRING THIS MORNING...AS IT MAY END UP BEING MORE RAIN THAN
SNOW DURING THE DAYLIGHT IN THAT AREA.
UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 518 AM CST SUN MAR 4 2012
ALBERTA CLIPPER SYSTEM WILL MOVE SOUTHEASTWARD THROUGH THE MIDWEST
LATER TODAY...WITH THE CENTER OF THE SURFACE LOW TAKING A TRACK FROM
THE DAKOTAS TO SOUTHEASTERN MO TO SOUTHERN KY. BAND OF SNOW TO THE
LEFT OF THE TRACK WILL AFFECT SPI THE STRONGEST WITH MVFR TEMPO IFR
CONDITIONS...WITH OTHER SITES FURTHER NORTH/EAST GETTING A MORE
GLANCING BLOW WITH MAINLY MVFR. WILL START THE SNOW AT PIA/SPI AROUND
22Z...AND A LITTLE LATER FOR BMI/DEC/CMI. THE SNOW WILL BE MOVING
PAST THE TERMINALS BY 06Z...LEAVING BEHIND SOME MVFR STRATOCU WHICH
WILL THEN CLEAR FROM WEST TO EAST AFTER 06Z. WINDS WILL BE WESTERLY
AROUND 10 KT BEFORE THE SNOW ARRIVES...LIGHT NORTHERLY AS THE LOW
MAKES ITS PASS TO THE WEST LATE AFTERNOON/EVENING...THEN NORTHWEST
10-15 KT AFTER 06Z.
04
&&
.PREV DISCUSSION...
ISSUED 313 AM CST SUN MAR 4 2012
RIDGING OVER THE WESTERN HALF OF THE CONUS THIS MORNING AS AN UPPER
TROF IS A LITTLE SLOW TO PROGRESS OUT OF THE MIDWEST...AND WILL
REMAIN IN PLACE AS A CLIPPER SYSTEM PUSHES OUT OF THE CANADIAN
ROCKIES DOWN INTO THE SYNOPTIC TROF TODAY AND TONIGHT BRINGING SNOW
CHANCES FOR MUCH OF THE CWA...WITH THE HIGHER ACCUMULATIONS EXPECTED
SOUTHWEST OF A LINE FROM PEORIA TO PARIS. MODELS ARE IN PRETTY GOOD
AGREEMENT OVERALL THROUGH MIDWEEK. ISSUES IN THE FORECAST CROP UP IN
THE EXTENDED WHEN ANOTHER TROF/LOW PRESSURE SYSTEM MOVE OUT OF THE
ROCKIES AND SRN PLAINS...AND UP THE OHIO RIVER VALLEY. PREVIOUS
MODEL RUNS HAVE HAD SOME SIGNIFICANT ISSUES DISCERNING THE BEHAVIOR
ULTIMATELY OF THE UPPER LOW...WITH THE GFS MOST NOTABLY CLOSING OFF
THE LOW AND STALLING A FRONTAL BOUNDARY FROM THE MID MISS RIVER
VALLEY UP INTO THE APPALACHIANS. ECMWF WAS MORE PROGRESSIVE OVERALL
IN PUSHING THE SYSTEM OUT QUICKLY. HOWEVER...THIS MODEL RUN BRINGS
THE ECMWF IN LINE WITH A CLOSED OFF LOW OVER THE SRN HALF OF THE
CONUS. NOT WILLING TO JUMP ON THE NEW RUN JUST YET...BUT WILL PRIME
THE FORECAST FOR A FEW ADJUSTMENTS IN THE LATTER HALF OF THE WORK
WEEK.
SHORT TERM...TODAY AND TONIGHT...
A QUICK CLIPPER SYSTEM IS PUSHING INTO THE MIDWEST THIS
MORNING/AFTERNOON...BRINGING SNOW AFTER NOON AND THROUGH MIDNIGHT.
PRECIP MAY START OUT AS RAIN IN THE EARLY AFTERNOON IN THE SWRN HALF
OF THE STATE...BUT THERMAL PROFILES QUICKLY MOVE OVER TO ALL SNOW IN
BOTH THE GFS AND THE NAM. 06Z HPC QPF PUTS THE FORECAST IN EXCESS OF
THE 2 INCH RANGE...BUT WITH SOME RAIN EXPECTED EARLY AND A SLIGHT
ADJUSTMENT TO THE QPF IN THE OVERNIGHT...BRINGS THE SNOW BACK TO A
1-2 INCH SCENARIO. TEMPS SIGNIFICANTLY COOLER NOW WITH THE SYSTEM
OVERALL. ABOVE FREEZING TEMPS BRIEFLY STICK AROUND IN THE EARLY
AFTERNOON HOURS PRIOR TO 22Z-00Z BEFORE EVAPORATIVE COOLING AND
RATHER QUICK SATURATION OF THE COLUMN SHOULD HELP TO SWITCH MOST OF
THE PRECIP OVER TO SNOWFALL. SNOW SHOULD BE WRAPPING UP JUST PRIOR
TO MIDNIGHT AS THE CLIPPER MOVES OUT INTO THE LARGER SCALE TROF AND
EXITS THE REGION.
LONG TERM...TOMORROW THROUGH SATURDAY...
WARMING TREND DELAYED A BIT MONDAY...WITH HIGH PRESSURE BUILDING
INTO THE MIDWEST AND ERN HALF OF THE CONUS. HOWEVER...TUES AND WED
LIKELY TO SEE TEMPS AROUND AND ABOVE 60 WITH PLENTY OF SOUTHERLY
WINDS AND LLVL WAA KICKING IN IN THE OVERNIGHT HOURS MON NIGHT. WINDY
CONDITIONS PREVAIL FOR TUESDAY AS THE MIDWEST GETS CAUGHT BETWEEN A
STUBBORN RIDGE OVER THE ATLANTIC STATES AND ANOTHER VIGOROUS WAVE
DIGGING IN OVER THE ROCKIES. AN ADVANCING COLD FRONT BRINGS PRECIP
TO THE REGION WITH THE INITIAL LARGE TROF. PRECIP...RAIN OR
SNOW...WED NIGHT THROUGH THURSDAY NIGHT. KEEPING FRIDAY POPS AWAY
STILL...BECAUSE THE MODELS HAVE PREVIOUSLY BEEN IN CONFLICT OVER ONE
POINT. THE GFS CUTS OFF THE 500 MB LOW...PUSHING A WARM FRONTAL
FEATURE INTO THE OHIO RIVER VALLEY ON FRIDAY. HOWEVER...THE MORE
PROGRESSIVE ECMWF HAS BEEN EXITING THE SYSTEM ALTOGETHER...NEVER
FORMING THE CUT OFF 500 MB LOW. HOWEVER...THE 00Z RUN SEEMS TO BE
GOING THE WAY OF THE GFS. NEXT ISSUE WILL BE A MATTER OF HOW FAR
NORTH ANY WARM FRONT ACTUALLY SETS UP WITH A LINGERING CUT OFF LOW
IN THE SW.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
325 PM EST SUN MAR 4 2012
.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A CLIPPER TYPE SYSTEM IS EXPECTED TO MOVE SOUTHEAST ACROSS THE OHIO
VALLEY TONIGHT. IN THE WAKE OF THIS SYSTEM...HIGH PRESSURE IS
EXPECTED TO BUILD IN THROUGH THE MIDDLE OF THE WEEK. A FRONTAL
SYSTEM MAY MOVE THROUGH THE AREA DURING THE LATTER PARTS OF THE
WEEK...WITH HIGH PRESSURE BUILDING IN FOR NEXT WEEKEND.
&&
.NEAR TERM /TONIGHT/...
CLIPPER SYSTEM CURRENTLY DROPPING THROUGH WESTERN IOWA EXPECTED TO
PUSH ACROSS THE SOUTHWEST CORNER OF INDIANA LATER TONIGHT BASED ON
SHORT TERM MODEL DATA. ALTHOUGH SYSTEM IS SMALL...IT BE WILL RIDING
ALONG A STRONG TEMPERATURE GRADIENT...SO THERE MAY BE A SHORT PERIOD
OF STRONG LIFT WITH THIS FEATURE. FEW REPORTS OF MODERATE/HEAVY SNOW
ASSOCIATED WITH THIS SYSTEM BEAR THIS OUT. APPEARS LIFT WILL BE
MOVING INTO THE SOUTHWEST ZONES AFTER ABOUT 050100Z. WILL GO WITH
LIKELY POPS OVER THE SOUTHWEST HALF OF THE FORECAST AREA BY THE MID
EVENING HOURS...TAPERING TO CHANCE POPS NORTHEAST. THICKNESSES
SUGGEST MOSTLY SNOW...BUT THERE MAY BE PERIOD OF MIXED PRECIPITATION
OR RAIN AT THE ONSET OVER THE FAR SOUTHWEST. POTENTIAL EXISTS FOR 2
TO 3 INCHES OF SNOWFALL NEAR THE FAR SOUTHWEST CORNER OF THE
FORECAST AREA...BUT AMOUNTS WILL TAPER OFF QUICKLY TO THE NORTHEAST
DUE TO THE COMPACT NATURE OF THE SYSTEM. LIFT TAPERS OFF QUITE A BIT
BY 050900Z...SO MOST OF THE PRECIPITATION SHOULD END PRIOR TO
SUNRISE.
LOW LEVEL THICKNESS PROGS SUGGEST THE GFS MOS LOWS TONIGHT MAY BE A
COUPLE OF DEGREES ON THE COOL SIDE. WILL NUDGE UP THE LOWS A BIT.
&&
.SHORT TERM /MONDAY AND TUESDAY/...
LOOKS LIKE A RATHER QUIET SHORT TERM AS THE MODELS SUGGEST
SUBSTANTIAL HEIGHT RISES AS LONG WAVE TROUGH PUSHES OFF TO THE
EAST...AND THE NEXT TROUGH DIGS INTO THE ROCKIES. DON/T SEE MUCH
OF A PRECIPITATION THREAT THROUGH THE MIDDLE OF THE WEEK WITH
SURFACE HIGH PRESSURE MOVING THROUGH AND LAYERED RELATIVE HUMIDITY
PANELS OFF THE MODELS QUITE DRY. TUESDAY MAY BE WINDY AS MODELS
SUGGEST A LOW LEVEL JET 45-60 KTS MAY BE IN THE AREA COUPLED WITH
POTENTIAL FOR GOOD MIXING.
PROGGED LOW LEVEL THICKNESSES SUGGEST THE GFS MOS HIGHS ON MONDAY
MAY BE A COUPLE OF DEGREES ON THE WARM SIDE...OTHERWISE THE GUIDANCE
DOESN/T LOOK TOO BAD.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MILD WINDY WEATHER CONTINUES TO BEGIN MIDWEEK AS THE OHIO VALLEY
REMAINS WEDGED BETWEEN THE STRONG HIGH PRESSURE ACROSS THE WESTERN
ATLANTIC AND THE APPROACHING COLD FRONT MOVING THROUGH THE CENTRAL
PLAINS. PRESENCE OF THE LARGE HIGH OFF TO THE EAST WILL ENSURE A
DRY DAY WEDNESDAY WITH A STEADY INCREASE IN CLOUDS AND MOISTURE TO
THE WEST AS THE APPROACHING BOUNDARY BEGINS TO TAP INTO NORTHWARD
ADVECTING GULF MOISTURE.
WIDESPREAD RAINFALL EXPECTED TO EXPAND ACROSS THE FORECAST AREA LATE
WEDNESDAY NIGHT INTO THURSDAY AS THE BOUNDARY PROGRESSES THROUGH THE
REGION. THE HIGH OFF TO THE EAST AND UPPER LEVEL FLOW NEARLY
PARALLEL TO THE SURFACE FRONT WILL CAUSE THE BOUNDARY TO ONLY SLOWLY
DROP THROUGH CENTRAL INDIANA...WITH RAIN NOT LIKELY TO CLEAR THE
FORECAST AREA UNTIL FRIDAY. WITH PLENTIFUL FORCING ALOFT AND LOW
LEVEL MOISTURE AVAILABLE...FELT COMFORTABLE IN MAINTAINING LIKELY
POPS. LEAVING ANY MENTION OF THUNDER OUT AT THIS TIME AS MODEL
SOUNDINGS CONTINUE TO SHOW A LACK OF ANY SIGNIFICANT INSTABILITY
ALOFT. DUE TO THE PROLONGED PERIOD WITH THE FRONTAL BOUNDARY IN THE
AREA AND WITH PROGGED PRECIP WATER VALUES APPROACHING 1.25 INCHES ON
THURSDAY...ANTICIPATE THIS WILL BE A SOAKING RAINFALL WITH POTENTIAL
FOR 1 TO 1.5 INCHES BY FRIDAY FOR MUCH OF THE REGION.
SOME DISCREPANCIES DEVELOPS BETWEEN THE OP GFS/GFS ENSEMBLE MEAN AND
THE EURO/UKMET/GGEM FOR THE WEEKEND AND FOCUS LARGELY ON THE
HANDLING OF THE DEEP UPPER TROUGH OVER THE SOUTHWEST U S. OP GFS/GFS
ENSEMBLE MEAN EJECTING THIS SYSTEM EAST INTO THE PLAINS CAUSING THE
BOUNDARY TO HANG FURTHER NORTH WITH A NEW SURFACE WAVE BEING
GENERATED AND SPREADING RAINFALL BACK INTO THE OHIO VALLEY FOR MUCH
OF THE WEEKEND. PREFER THE MORE CONSISTENT EURO/UKMET/GGEM CONSENSUS
AT THIS TIME WHICH SPREADS LARGE HIGH PRESSURE AND A COOL DRY
AIRMASS ACROSS THE REGION FOR MUCH OF THE WEEKEND AS THE BOUNDARY IS
FORCED WELL SOUTH AND UPPER ENERGY HOLDS BACK OVER THE SOUTHWEST U
S.
&&
.AVIATION /DISCUSSION FOR 042100Z KIND TAF UPDATE/...
MINOR TWEAKS MADE TO KIND TAF PER OBSERVATIONS. OTHERWISE...NO OTHER
CHANGES NEEDED AT THIS TIME. PREVIOUS AVIATION DISCUSSION FOLLOWS...
VFR CONDITIONS INTO EARLY EVENING...MVFR CONDITIONS DEVELOPING
OVERNIGHT.
UPPER LEVEL WAVE THAT HAS CONTRIBUTED TO STRATOCU AND FLURRIES/
LIGHT SNOW SHOWERS THIS MORNING IS SHIFTING EAST INTO OHIO AT THIS
TIME. PRESENCE OF COLD POOL ALOFT HOWEVER FAVORING A WESTWARD
EXPANSION TO STRATOCU ACROSS THE REMAINDER OF CENTRAL INDIANA.
WHILE THE SUN MAY POKE OUT AT THE TERMINALS BRIEFLY OVER THE NEXT
FEW HOURS...SKIES WILL REMAIN MOSTLY CLOUDY WITH CEILINGS AT
4-5KFT. WESTERLY WINDS AT 10-15KTS WILL CONTINUE FOR THE DURATION
OF THE AFTERNOON WITH A SPORADIC HIGHER GUST NEAR 20KTS NOT OUT OF
THE QUESTION.
CLOUD SHIELD ASSOCIATED WITH APPROACHING CLIPPER CURRENTLY ACROSS
WESTERN IOWA WILL EXPAND INTO MUCH OF THE FORECAST AREA BY LATE
AFTERNOON. HRRR HAS A NICE HANDLE ON SPREADING THE SWATH OF LIGHT
SNOW ASSOCIATED WITH THE CLIPPER INTO THE LOWER WABASH VALLEY
AFTER 23Z. AT THIS POINT...THE TRACK OF THE HEAVIER SNOW LIKELY TO
REMAIN SOUTH OF ALL TERMINALS WITH KBMG AND POSSIBLY KHUF LIKELY
TO SNEAK INTO MVFR VISIBILITIES ASSOCIATED WITH THE NORTHERN FLANK
OF THE LIGHT SNOW LATER THIS EVENING. SHOULD BE A VERY SHARP
CUTOFF TO THE SNOW FURTHER NORTH WITH KIND LIKELY TO ONLY SEE
FLURRIES AND KLAF POTENTIALLY REMAINING DRY. MODEL SOUNDINGS DO
SHOW MVFR CEILINGS AROUND 2500FT EXPANDING BACK ACROSS THE
TERMINALS OVERNIGHT AS LOW LEVEL WIND FLOW VEERS TO A N/NW
DIRECTION WITH PASSAGE OF THE LOW. LOWER CEILINGS WILL REMAIN
THROUGH DAYBREAK UNTIL TRAILING UPPER WAVE AXIS CAN SHIFT EAST OF
THE REGION. CYCLONIC FLOW ON THE BACK SIDE OF THE UPPER WAVE AND
FAVORABLE CONVECTIVE TEMPERATURES WILL ENCOURAGE CONTINUED VFR
STRATOCU/CU DEVELOPMENT OVER THE REGION INTO MONDAY AFTERNOON
BEFORE DRIER AIR BUILDS IN AND ENABLES CLOUD COVERAGE TO DIMINISH.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS
SHORT TERM...JAS
LONG TERM....RYAN
AVIATION...RYAN/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
255 PM EST SUN MAR 4 2012
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A CLIPPER TYPE SYSTEM IS EXPECTED TO MOVE SOUTHEAST ACROSS THE OHIO
VALLEY TONIGHT. IN THE WAKE OF THIS SYSTEM...HIGH PRESSURE IS
EXPECTED TO BUILD IN THROUGH THE MIDDLE OF THE WEEK. A FRONTAL
SYSTEM MAY MOVE THROUGH THE AREA DURING THE LATTER PARTS OF THE
WEEK...WITH HIGH PRESSURE BUILDING IN FOR NEXT WEEKEND.
&&
.NEAR TERM /TONIGHT/...
CLIPPER SYSTEM CURRENTLY DROPPING THROUGH WESTERN IOWA EXPECTED TO
PUSH ACROSS THE SOUTHWEST CORNER OF INDIANA LATER TONIGHT BASED ON
SHORT TERM MODEL DATA. ALTHOUGH SYSTEM IS SMALL...IT BE WILL RIDING
ALONG A STRONG TEMPERATURE GRADIENT...SO THERE MAY BE A SHORT PERIOD
OF STRONG LIFT WITH THIS FEATURE. FEW REPORTS OF MODERATE/HEAVY SNOW
ASSOCIATED WITH THIS SYSTEM BEAR THIS OUT. APPEARS LIFT WILL BE
MOVING INTO THE SOUTHWEST ZONES AFTER ABOUT 050100Z. WILL GO WITH
LIKELY POPS OVER THE SOUTHWEST HALF OF THE FORECAST AREA BY THE MID
EVENING HOURS...TAPERING TO CHANCE POPS NORTHEAST. THICKNESSES
SUGGEST MOSTLY SNOW...BUT THERE MAY BE PERIOD OF MIXED PRECIPITATION
OR RAIN AT THE ONSET OVER THE FAR SOUTHWEST. POTENTIAL EXISTS FOR 2
TO 3 INCHES OF SNOWFALL NEAR THE FAR SOUTHWEST CORNER OF THE
FORECAST AREA...BUT AMOUNTS WILL TAPER OFF QUICKLY TO THE NORTHEAST
DUE TO THE COMPACT NATURE OF THE SYSTEM. LIFT TAPERS OFF QUITE A BIT
BY 050900Z...SO MOST OF THE PRECIPITATION SHOULD END PRIOR TO
SUNRISE.
LOW LEVEL THICKNESS PROGS SUGGEST THE GFS MOS LOWS TONIGHT MAY BE A
COUPLE OF DEGREES ON THE COOL SIDE. WILL NUDGE UP THE LOWS A BIT.
&&
.SHORT TERM /MONDAY AND TUESDAY/...
LOOKS LIKE A RATHER QUIET SHORT TERM AS THE MODELS SUGGEST
SUBSTANTIAL HEIGHT RISES AS LONG WAVE TROUGH PUSHES OFF TO THE
EAST...AND THE NEXT TROUGH DIGS INTO THE ROCKIES. DON/T SEE MUCH
OF A PRECIPITATION THREAT THROUGH THE MIDDLE OF THE WEEK WITH
SURFACE HIGH PRESSURE MOVING THROUGH AND LAYERED RELATIVE HUMIDITY
PANELS OFF THE MODELS QUITE DRY. TUESDAY MAY BE WINDY AS MODELS
SUGGEST A LOW LEVEL JET 45-60 KTS MAY BE IN THE AREA COUPLED WITH
POTENTIAL FOR GOOD MIXING.
PROGGED LOW LEVEL THICKNESSES SUGGEST THE GFS MOS HIGHS ON MONDAY
MAY BE A COUPLE OF DEGREES ON THE WARM SIDE...OTHERWISE THE GUIDANCE
DOESN/T LOOK TOO BAD.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MILD WINDY WEATHER CONTINUES TO BEGIN MIDWEEK AS THE OHIO VALLEY
REMAINS WEDGED BETWEEN THE STRONG HIGH PRESSURE ACROSS THE WESTERN
ATLANTIC AND THE APPROACHING COLD FRONT MOVING THROUGH THE CENTRAL
PLAINS. PRESENCE OF THE LARGE HIGH OFF TO THE EAST WILL ENSURE A
DRY DAY WEDNESDAY WITH A STEADY INCREASE IN CLOUDS AND MOISTURE TO
THE WEST AS THE APPROACHING BOUNDARY BEGINS TO TAP INTO NORTHWARD
ADVECTING GULF MOISTURE.
WIDESPREAD RAINFALL EXPECTED TO EXPAND ACROSS THE FORECAST AREA LATE
WEDNESDAY NIGHT INTO THURSDAY AS THE BOUNDARY PROGRESSES THROUGH THE
REGION. THE HIGH OFF TO THE EAST AND UPPER LEVEL FLOW NEARLY
PARALLEL TO THE SURFACE FRONT WILL CAUSE THE BOUNDARY TO ONLY SLOWLY
DROP THROUGH CENTRAL INDIANA...WITH RAIN NOT LIKELY TO CLEAR THE
FORECAST AREA UNTIL FRIDAY. WITH PLENTIFUL FORCING ALOFT AND LOW
LEVEL MOISTURE AVAILABLE...FELT COMFORTABLE IN MAINTAINING LIKELY
POPS. LEAVING ANY MENTION OF THUNDER OUT AT THIS TIME AS MODEL
SOUNDINGS CONTINUE TO SHOW A LACK OF ANY SIGNIFICANT INSTABILITY
ALOFT. DUE TO THE PROLONGED PERIOD WITH THE FRONTAL BOUNDARY IN THE
AREA AND WITH PROGGED PRECIP WATER VALUES APPROACHING 1.25 INCHES ON
THURSDAY...ANTICIPATE THIS WILL BE A SOAKING RAINFALL WITH POTENTIAL
FOR 1 TO 1.5 INCHES BY FRIDAY FOR MUCH OF THE REGION.
SOME DISCREPANCIES DEVELOPS BETWEEN THE OP GFS/GFS ENSEMBLE MEAN AND
THE EURO/UKMET/GGEM FOR THE WEEKEND AND FOCUS LARGELY ON THE
HANDLING OF THE DEEP UPPER TROUGH OVER THE SOUTHWEST U S. OP GFS/GFS
ENSEMBLE MEAN EJECTING THIS SYSTEM EAST INTO THE PLAINS CAUSING THE
BOUNDARY TO HANG FURTHER NORTH WITH A NEW SURFACE WAVE BEING
GENERATED AND SPREADING RAINFALL BACK INTO THE OHIO VALLEY FOR MUCH
OF THE WEEKEND. PREFER THE MORE CONSISTENT EURO/UKMET/GGEM CONSENSUS
AT THIS TIME WHICH SPREADS LARGE HIGH PRESSURE AND A COOL DRY
AIRMASS ACROSS THE REGION FOR MUCH OF THE WEEKEND AS THE BOUNDARY IS
FORCED WELL SOUTH AND UPPER ENERGY HOLDS BACK OVER THE SOUTHWEST U S.
&&
.AVIATION /DISCUSSION FOR 041800Z TAF ISSUANCE/...
VFR CONDITIONS INTO EARLY EVENING...MVFR CONDITIONS DEVELOPING
OVERNIGHT.
UPPER LEVEL WAVE THAT HAS CONTRIBUTED TO STRATOCU AND FLURRIES/
LIGHT SNOW SHOWERS THIS MORNING IS SHIFTING EAST INTO OHIO AT THIS
TIME. PRESENCE OF COLD POOL ALOFT HOWEVER FAVORING A WESTWARD
EXPANSION TO STRATOCU ACROSS THE REMAINDER OF CENTRAL INDIANA.
WHILE THE SUN MAY POKE OUT AT THE TERMINALS BRIEFLY OVER THE NEXT
FEW HOURS...SKIES WILL REMAIN MOSTLY CLOUDY WITH CEILINGS AT
4-5KFT. WESTERLY WINDS AT 10-15KTS WILL CONTINUE FOR THE DURATION
OF THE AFTERNOON WITH A SPORADIC HIGHER GUST NEAR 20KTS NOT OUT OF
THE QUESTION.
CLOUD SHIELD ASSOCIATED WITH APPROACHING CLIPPER CURRENTLY ACROSS
WESTERN IOWA WILL EXPAND INTO MUCH OF THE FORECAST AREA BY LATE
AFTERNOON. HRRR HAS A NICE HANDLE ON SPREADING THE SWATH OF LIGHT
SNOW ASSOCIATED WITH THE CLIPPER INTO THE LOWER WABASH VALLEY
AFTER 23Z. AT THIS POINT...THE TRACK OF THE HEAVIER SNOW LIKELY TO
REMAIN SOUTH OF ALL TERMINALS WITH KBMG AND POSSIBLY KHUF LIKELY
TO SNEAK INTO MVFR VISIBILITIES ASSOCIATED WITH THE NORTHERN FLANK
OF THE LIGHT SNOW LATER THIS EVENING. SHOULD BE A VERY SHARP
CUTOFF TO THE SNOW FURTHER NORTH WITH KIND LIKELY TO ONLY SEE
FLURRIES AND KLAF POTENTIALLY REMAINING DRY. MODEL SOUNDINGS DO
SHOW MVFR CEILINGS AROUND 2500FT EXPANDING BACK ACROSS THE
TERMINALS OVERNIGHT AS LOW LEVEL WIND FLOW VEERS TO A N/NW
DIRECTION WITH PASSAGE OF THE LOW. LOWER CEILINGS WILL REMAIN
THROUGH DAYBREAK UNTIL TRAILING UPPER WAVE AXIS CAN SHIFT EAST OF
THE REGION. CYCLONIC FLOW ON THE BACK SIDE OF THE UPPER WAVE AND
FAVORABLE CONVECTIVE TEMPERATURES WILL ENCOURAGE CONTINUED VFR
STRATOCU/CU DEVELOPMENT OVER THE REGION INTO MONDAY AFTERNOON
BEFORE DRIER AIR BUILDS IN AND ENABLES CLOUD COVERAGE TO DIMINISH.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS
SHORT TERM...JAS
LONG TERM....RYAN
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
233 PM EST SUN MAR 4 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A CLIPPER TYPE SYSTEM IS EXPECTED TO MOVE SOUTHEAST ACROSS THE OHIO
VALLEY TONIGHT. IN THE WAKE OF THIS SYSTEM...HIGH PRESSURE IS
EXPECTED TO BUILD IN THROUGH THE MIDDLE OF THE WEEK. A FRONTAL
SYSTEM MAY MOVE THROUGH THE AREA DURING THE LATTER PARTS OF THE
WEEK...WITH HIGH PRESSURE BUILDING IN FOR NEXT WEEKEND.
&&
.NEAR TERM /TONIGHT...
CLIPPER SYSTEM CURRENTLY DROPPING THROUGH WESTERN IOWA EXPECTED TO
PUSH ACROSS THE SOUTHWEST CORNER OF INDIANA LATER TONIGHT BASED ON
SHORT TERM MODEL DATA. ALTHOUGH SYSTEM IS SMALL...IT BE WILL RIDING
ALONG A STRONG TEMPERATURE GRADIENT...SO THERE MAY BE A SHORT PERIOD
OF STRONG LIFT WITH THIS FEATURE. FEW REPORTS OF MODERATE/HEAVY SNOW
ASSOCIATED WITH THIS SYSTEM BEAR THIS OUT. APPEARS LIFT WILL BE
MOVING INTO THE SOUTHWEST ZONES AFTER ABOUT 050100Z. WILL GO WITH
LIKELY POPS OVER THE SOUTHWEST HALF OF THE FORECAST AREA BY THE MID
EVENING HOURS...TAPERING TO CHANCE POPS NORTHEAST. THICKNESSES
SUGGEST MOSTLY SNOW...BUT THERE MAY BE PERIOD OF MIXED PRECIPITATION
OR RAIN AT THE ONSET OVER THE FAR SOUTHWEST. POTENTIAL EXISTS FOR 2
TO 3 INCHES OF SNOWFALL NEAR THE FAR SOUTHWEST CORNER OF THE
FORECAST AREA...BUT AMOUNTS WILL TAPER OFF QUICKLY TO THE NORTHEAST
DUE TO THE COMPACT NATURE OF THE SYSTEM. LIFT TAPERS OFF QUITE A BIT
BY 050900Z...SO MOST OF THE PRECIPITATION SHOULD END PRIOR TO
SUNRISE.
LOW LEVEL THICKNESS PROGS SUGGEST THE GFS MOS LOWS TONIGHT MAY BE A
COUPLE OF DEGREES ON THE COOL SIDE. WILL NUDGE UP THE LOWS A BIT.
&&
.SHORT TERM / MONDAY THROUGH WEDNESDAY/...
LOOKS LIKE A RATHER QUIET SHORT TERM AS THE MODELS SUGGEST
SUBSTANTIAL HEIGHT RISES AS LONG WAVE TROUGH PUSHES OFF TO THE
EAST...AND THE NEXT TROUGH DIGS INTO THE ROCKIES. DON/T SEE MUCH OF
A PRECIPITATION THREAT THROUGH THE MIDDLE OF THE WEEK WITH SURFACE
HIGH PRESSURE MOVING THROUGH AND LAYERED RELATIVE HUMIDITY PANELS
OFF THE MODELS QUITE DRY. TUESDAY AND WEDNESDAY MAY BE WINDY AS
MODELS SUGGEST A LOW LEVEL JET 45-60 KTS MAY BE IN THE AREA COUPLED
WITH POTENTIAL FOR GOOD MIXING.
PROGGED LOW LEVEL THICKNESSES SUGGEST THE GFS MOS HIGHS ON MONDAY
MAY BE A COUPLE OF DEGREES ON THE WARM SIDE...OTHERWISE THE GUIDANCE
DOESN/T LOOK TOO BAD.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MAIN CHALLENGE TO THE EXTENDED WILL BE TEMPERATURE AND POP TRENDS BY
FRIDAY. THE NEW 00Z ECMWF IS NOW NOT AS AMPLIFIED WITH A NORTHERN
STREAM TROUGH THAT SWINGS ACROSS THE GREAT LAKES ON FRIDAY...WHILE
THE 00Z GFS AND GEFS ARE A BIT MORE AMPLIFIED LEANING A BIT CLOSER
TO THE EURO. MODELS ALSO NOW ARE CLOSE IN TIMING ON BRINGING A FRONT
SOUTHEAST ACROSS CENTRAL INDIANA ON THURSDAY WITH MODERATE QPF
THURSDAY AND THURSDAY NIGHT AND LINGERING POPS ACROSS OUR SOUTH ON
FRIDAY MORNING. THE 00Z ECMWF BEING NOT AS AMPLIFIED AS PREVIOUS
RUNS IS NOW NOT AS COLD AS ITS 12Z RUN OR THE 00Z GEM...BUT STILL
COLDER THAN THE GFS...AND THE CENTRAL REGION INITIALIZATION EXTENDED
SEEMED TO GO ALONG WITH THE EURO TREND ON TEMPERATURES FRIDAY AND
SATURDAY. TO WRAP IT UP...RIDGING WILL ALLOW FOR DRY AND MILD
TEMPERATURES ON WEDNESDAY WITH SHOWERS MOVING IN AHEAD OF A COLD
FRONT WEDNESDAY NIGHT AND THURSDAY. THURSDAY WILL SEE THE MILD
TEMPERATURES PRIOR TO COLD FRONT. THEN...IT APPEARS THE SHOWERS WILL
BE ENDING FRIDAY MORNING SOUTH WITH MORE SEASONABLE TEMPERATURES AND
DRY WEATHER FOR THE REST OF THE WEEKEND AS COOL CANADIAN HIGH
PRESSURE BUILDS IN.
&&
.AVIATION /DISCUSSION FOR 041800Z TAF ISSUANCE/...
VFR CONDITIONS INTO EARLY EVENING...MVFR CONDITIONS DEVELOPING
OVERNIGHT.
UPPER LEVEL WAVE THAT HAS CONTRIBUTED TO STRATOCU AND FLURRIES/
LIGHT SNOW SHOWERS THIS MORNING IS SHIFTING EAST INTO OHIO AT THIS
TIME. PRESENCE OF COLD POOL ALOFT HOWEVER FAVORING A WESTWARD
EXPANSION TO STRATOCU ACROSS THE REMAINDER OF CENTRAL INDIANA.
WHILE THE SUN MAY POKE OUT AT THE TERMINALS BRIEFLY OVER THE NEXT
FEW HOURS...SKIES WILL REMAIN MOSTLY CLOUDY WITH CEILINGS AT
4-5KFT. WESTERLY WINDS AT 10-15KTS WILL CONTINUE FOR THE DURATION
OF THE AFTERNOON WITH A SPORADIC HIGHER GUST NEAR 20KTS NOT OUT OF
THE QUESTION.
CLOUD SHIELD ASSOCIATED WITH APPROACHING CLIPPER CURRENTLY ACROSS
WESTERN IOWA WILL EXPAND INTO MUCH OF THE FORECAST AREA BY LATE
AFTERNOON. HRRR HAS A NICE HANDLE ON SPREADING THE SWATH OF LIGHT
SNOW ASSOCIATED WITH THE CLIPPER INTO THE LOWER WABASH VALLEY
AFTER 23Z. AT THIS POINT...THE TRACK OF THE HEAVIER SNOW LIKELY TO
REMAIN SOUTH OF ALL TERMINALS WITH KBMG AND POSSIBLY KHUF LIKELY
TO SNEAK INTO MVFR VISIBILITIES ASSOCIATED WITH THE NORTHERN FLANK
OF THE LIGHT SNOW LATER THIS EVENING. SHOULD BE A VERY SHARP
CUTOFF TO THE SNOW FURTHER NORTH WITH KIND LIKELY TO ONLY SEE
FLURRIES AND KLAF POTENTIALLY REMAINING DRY. MODEL SOUNDINGS DO
SHOW MVFR CEILINGS AROUND 2500FT EXPANDING BACK ACROSS THE
TERMINALS OVERNIGHT AS LOW LEVEL WIND FLOW VEERS TO A N/NW
DIRECTION WITH PASSAGE OF THE LOW. LOWER CEILINGS WILL REMAIN
THROUGH DAYBREAK UNTIL TRAILING UPPER WAVE AXIS CAN SHIFT EAST OF
THE REGION. CYCLONIC FLOW ON THE BACK SIDE OF THE UPPER WAVE AND
FAVORABLE CONVECTIVE TEMPERATURES WILL ENCOURAGE CONTINUED VFR
STRATOCU/CU DEVELOPMENT OVER THE REGION INTO MONDAY AFTERNOON
BEFORE DRIER AIR BUILDS IN AND ENABLES CLOUD COVERAGE TO DIMINISH.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS
SHORT TERM...JAS
LONG TERM....MK
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1215 PM EST SUN MAR 4 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A CLIPPER SYSTEM WILL DIVE JUST TO THE SOUTHWEST AND SOUTH OF THE
FORECAST AREA INTO TONIGHT...BRINGING SOME SNOW TO PARTS OF THE
AREA. LATER IN THE WEEK A COLD FRONT WILL BRING RAIN TO THE AREA.
TEMPERATURES WILL START OUT COLD EARLY THIS WEEK...BUT WARM TO
ABOVE AVERAGE BY MID WEEK.
&&
.NEAR TERM /REST OF TODAY/...
UPPER TROUGH CURRENTLY PASSING THROUGH THE LOCAL AREA RESULTING IN
SOME LIGHT SNOW SHOWER ACTIVITY OVER THE NORTHEAST ZONES. WILL ADD
SCATTERED SHOW SHOWERS IN THE NORTHEAST THROUGH ABOUT MIDDAY WHEN
TROUGH SHOULD BE EAST OF THE AREA.
OTHERWISE...SHORT TERM MODEL DATA INDICATE VERY STEEP LOW LEVEL
LAPSE RATES ACROSS THE AREA TODAY...SO SOME LIGHT INSTABILITY
SHOWERS OF RAIN OR SNOW MAY DEVELOP LATER TODAY. WILL KEEP POPS
AS IS FOR THE AFTERNOON HOURS. APPEARS LIFT FROM SYSTEM CURRENTLY
DROPPING SOUTHEAST THROUGH THE NORTHERN MIDWEST MAY ARRIVE LATE
THIS AFTERNOON IN THE SOUTHWEST ZONES...SO THE HIGHER POPS IN
THOSE AREAS STILL WARRANTED.
PROGGED LOW LEVEL THICKNESSES SUGGEST THE FORECAST HIGHS FOR TODAY
STILL LOOK GOOD FOR THE MOST PART...SO NO CHANGES THERE AT THIS TIME.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
FOCUS IS ON CLIPPER SYSTEM TONIGHT. MODELS ARE IN PRETTY GOOD
AGREEMENT WITH MOST FEATURES. NAM/GFS MAY BE OVERDOING THE QPF
FROM THE CLIPPER GIVEN NOT A LOT OF MOISTURE IS AVAILABLE WITH THE
SYSTEM. TRENDED TOWARD THE DRIER SREF MEAN AND THE ECMWF.
ISENTROPIC LIFT AND SOME ADDITIONAL LIFT PROVIDED BY AN UPPER JET
SHOULD BRING MEASURABLE PRECIPITATION TO THE SOUTHWEST PART OF THE
FORECAST AREA TONIGHT. TYPICALLY THERE IS A TIGHT GRADIENT WITH
PRECIPITATION ASSOCIATED WITH CLIPPERS. THUS WENT LIKELY POPS
ACROSS THE FAR SOUTH...WITH LOW CHANCE CATEGORY CENTRAL...AND
SLIGHT CHANCE POPS NORTH.
FORECAST SOUNDINGS INDICATE THAT SNOW SHOULD BE THE MAIN
PRECIPITATION TYPE. CANNOT RULE OUT A MIX OF RAIN AND SNOW AT THE
ONSET ACROSS THE SOUTH...BUT AS TEMPERATURES QUICKLY COOL TO THE
WET BULB TEMPERATURES PRECIPITATION SHOULD BECOME SNOW.
GIVEN THE RELATIVELY LIMITED MOISTURE...WENT 1 TO MAYBE 2 INCHES
OF SNOW IN THE FAR SOUTH...WITH LESS THAN INCH NORTH OF A TERRE
HAUTE TO COLUMBUS LINE. GIVEN CLOUDS AND PRECIPITATION STUCK WITH
A BLEND OF MODEL OUTPUT FOR LOWS.
FORCING WILL BE WELL EAST OF THE AREA BY MONDAY SO CONTINUED WITH
A DRY FORECAST THEN. WARM ADVECTION WILL KICK IN DURING THE
DAY...ERODING ANY LINGERING CLOUDS DURING THE DAY. GIVEN CLOUDS
AND POSSIBLE SNOW COVER TO START THE DAY WENT BELOW THE MAV MOS
FOR HIGHS.
HIGH PRESSURE WILL BUILD IN FOR MONDAY NIGHT INTO TUESDAY
NIGHT...BRINGING DRY AND WARMER CONDITIONS. GENERALLY STUCK WITH A
BLEND OF MODELS FOR TEMPERATURES.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MAIN CHALLENGE TO THE EXTENDED WILL BE TEMPERATURE AND POP TRENDS BY
FRIDAY. THE NEW 00Z ECMWF IS NOW NOT AS AMPLIFIED WITH A NORTHERN
STREAM TROUGH THAT SWINGS ACROSS THE GREAT LAKES ON FRIDAY...WHILE
THE 00Z GFS AND GEFS ARE A BIT MORE AMPLIFIED LEANING A BIT CLOSER
TO THE EURO. MODELS ALSO NOW ARE CLOSE IN TIMING ON BRINGING A FRONT
SOUTHEAST ACROSS CENTRAL INDIANA ON THURSDAY WITH MODERATE QPF
THURSDAY AND THURSDAY NIGHT AND LINGERING POPS ACROSS OUR SOUTH ON
FRIDAY MORNING. THE 00Z ECMWF BEING NOT AS AMPLIFIED AS PREVIOUS
RUNS IS NOW NOT AS COLD AS ITS 12Z RUN OR THE 00Z GEM...BUT STILL
COLDER THAN THE GFS...AND THE CENTRAL REGION INITIALIZATION EXTENDED
SEEMED TO GO ALONG WITH THE EURO TREND ON TEMPERATURES FRIDAY AND
SATURDAY. TO WRAP IT UP...RIDGING WILL ALLOW FOR DRY AND MILD
TEMPERATURES ON WEDNESDAY WITH SHOWERS MOVING IN AHEAD OF A COLD
FRONT WEDNESDAY NIGHT AND THURSDAY. THURSDAY WILL SEE THE MILD
TEMPERATURES PRIOR TO COLD FRONT. THEN...IT APPEARS THE SHOWERS WILL
BE ENDING FRIDAY MORNING SOUTH WITH MORE SEASONABLE TEMPERATURES AND
DRY WEATHER FOR THE REST OF THE WEEKEND AS COOL CANADIAN HIGH
PRESSURE BUILDS IN.
&&
.AVIATION /DISCUSSION FOR 041800Z TAF ISSUANCE/...
VFR CONDITIONS INTO EARLY EVENING...MVFR CONDITIONS DEVELOPING
OVERNIGHT.
UPPER LEVEL WAVE THAT HAS CONTRIBUTED TO STRATOCU AND FLURRIES/
LIGHT SNOW SHOWERS THIS MORNING IS SHIFTING EAST INTO OHIO AT THIS
TIME. PRESENCE OF COLD POOL ALOFT HOWEVER FAVORING A WESTWARD
EXPANSION TO STRATOCU ACROSS THE REMAINDER OF CENTRAL INDIANA.
WHILE THE SUN MAY POKE OUT AT THE TERMINALS BRIEFLY OVER THE NEXT
FEW HOURS...SKIES WILL REMAIN MOSTLY CLOUDY WITH CEILINGS AT
4-5KFT. WESTERLY WINDS AT 10-15KTS WILL CONTINUE FOR THE DURATION
OF THE AFTERNOON WITH A SPORADIC HIGHER GUST NEAR 20KTS NOT OUT OF
THE QUESTION.
CLOUD SHIELD ASSOCIATED WITH APPROACHING CLIPPER CURRENTLY ACROSS
WESTERN IOWA WILL EXPAND INTO MUCH OF THE FORECAST AREA BY LATE
AFTERNOON. HRRR HAS A NICE HANDLE ON SPREADING THE SWATH OF LIGHT
SNOW ASSOCIATED WITH THE CLIPPER INTO THE LOWER WABASH VALLEY
AFTER 23Z. AT THIS POINT...THE TRACK OF THE HEAVIER SNOW LIKELY TO
REMAIN SOUTH OF ALL TERMINALS WITH KBMG AND POSSIBLY KHUF LIKELY
TO SNEAK INTO MVFR VISIBILITIES ASSOCIATED WITH THE NORTHERN FLANK
OF THE LIGHT SNOW LATER THIS EVENING. SHOULD BE A VERY SHARP
CUTOFF TO THE SNOW FURTHER NORTH WITH KIND LIKELY TO ONLY SEE
FLURRIES AND KLAF POTENTIALLY REMAINING DRY. MODEL SOUNDINGS DO
SHOW MVFR CEILINGS AROUND 2500FT EXPANDING BACK ACROSS THE
TERMINALS OVERNIGHT AS LOW LEVEL WIND FLOW VEERS TO A N/NW
DIRECTION WITH PASSAGE OF THE LOW. LOWER CEILINGS WILL REMAIN
THROUGH DAYBREAK UNTIL TRAILING UPPER WAVE AXIS CAN SHIFT EAST OF
THE REGION. CYCLONIC FLOW ON THE BACK SIDE OF THE UPPER WAVE AND
FAVORABLE CONVECTIVE TEMPERATURES WILL ENCOURAGE CONTINUED VFR
STRATOCU/CU DEVELOPMENT OVER THE REGION INTO MONDAY AFTERNOON
BEFORE DRIER AIR BUILDS IN AND ENABLES CLOUD COVERAGE TO DIMINISH.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...JAS
SHORT TERM...50
LONG TERM....MK
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1114 AM CST SUN MAR 4 2012
.AVIATION...
A FAST MOVING AND SMALL STORM SYSTEM WILL BRING A PERIOD OF LIGHT
TO MODERATE SNOW TO SOUTHEAST IOWA THIS AFTERNOON. CID AND MLI
WILL BE AT THE EDGE OF THIS SNOW SYSTEM...AND MAY EXPERIENCE A
BRIEF LIGHT SNOW VISIBILITY RESTRICTIONS AROUND 5 MILES THIS
AFTERNOON. BRL...WILL SEE MODERATE SNOW POTENTIALLY FOR A PERIOD
FROM 20Z TO 00Z THIS AFTERNOON. VISIBILITIES OF 1/2 TO 1 MILE WILL
BE COMMON AT BRL. DBQ...AND THE REST OF NORTHEAST IOWA WILL LIKELY
REMAIN SNOW FREE...AND VFR. AFTER 02Z...ALL SITES WILL BE VFR
THROUGH THE REST OF TONIGHT AS HIGH PRESSURE MOVES IN. WINDS THIS
AFTERNOON AND THIS EVENING WILL BE UNDER 10KTS FROM THE
WEST...TONIGHT...NORTH WINDS AROUND 10 TO 12 KTS ARE
EXPECTED...BEFORE BECOMING LIGHT WEST AGAIN MONDAY MORNING AFTER
12Z.
..ERVIN..
&&
.PREV DISCUSSION... /ISSUED 751 AM CST SUN MAR 4 2012/
UPDATE...
HAVE UPDATED THE FORECAST FOR PERIOD OF SUNSHINE THIS MORNING AND
TO DELAY THE ONSET OF LIGHT SNOW AND FLURRIES IN THE WEST. BASED
ON SLOWER TIMING OF THE LATEST RUC AND NAM...THE DEVELOPING LIGHT
SNOW WITH THE CLIPPER SYSTEM NOW OVER THE EASTERN DAKOTAS WILL NOT
REACH CENTRAL IA UNTIL 18Z...AND MAY NOT DEVELOP INTO MEASURABLE
LIGHT SNOW IN OUR WESTERN COUNTIES UNTIL 1 OR 2 PM. EXPECTED SNOW
AMOUNTS LOOK ON TRACK...BUT MODEL TRENDS ARE SUGGESTING A SLIGHT
SW SHIFT MAY TAKE PLACE. ..SHEETS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
504 PM EST SUN MAR 4 2012
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL LINGER OVER NEW ENGLAND TONIGHT AND
WILL GRADUALLY GIVE WAY TO HIGH PRESSURE BUILDING IN FROM THE WEST
ON MONDAY. HIGH PRESSURE WILL CREST OVER THE REGION ON TUESDAY AND
WILL HOLD OFF THE EAST COAST THROUGH WEDNESDAY. A WEAK COLD FRONT
WILL SLOWLY APPROACH FROM THE NORTHWEST ON THURSDAY AND WILL PUSH
SOUTH THROUGH THE REGION THURSDAY EVENING. HIGH PRESSURE WILL
BUILD IN BEHIND THE FRONT THURSDAY NIGHT...SHIFTING OFFSHORE
FRIDAY AFTERNOON. A COLD FRONT WILL DROP SOUTH FROM CANADA ON
SATURDAY MOVING OFFSHORE BY LATE IN THE DAY. HIGH PRESSURE WILL
BUILD OVER NEW ENGLAND ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPDATE...SFC TROF CONTINUES TO SLOWLY SAG SWD TOWARDS THE COAST.
18Z/04 NAM DOES PICK UP ON THE MOISTURE CONVERGENCE IN THE LLVLS
ROUGHLY PARALLELING THE MTNS...BEFORE SAGGING SEWD AND ARCING
TOWARDS THE NRN SEACOAST AREAS. THIS IS ALSO SUPPORTIVE OF THE
PREVIOUS SHIFT/S THINKING THAT SHORT TERM HI-RES MODELS ARE
PICKING UP ON PSBL BANDED SNFL NEAR THE COAST LATER TNGT. BASED ON
UPSTREAM REPORTS IN VT...AND CONVECTIVE NATURE OF SNFL IN THE
MTNS. HAVE UPPED BOTH QPF AND SNFL AMNTS IN THE NEAR TERM. WILL
CONTINUE TO MONITOR TRENDS TO SEE IF SIMILAR CHANGES NEED TO BE
MADE FOR NEAR THE COAST LATER.
PREVIOUS DISCUSSION...INTERESTING SLOW MOVING BAND OF SHSN
MOVING ACROSS NRN NEW ENG IN ASSOC WITH COLD FRONT SETTLING
SOUTHWARD. VSBL SATELLITE IMAGES CONTINUES TO SHOW THE CONVECTIVE
LOOKING CLOUDS SHIFTING SLOWLY TO THE EAST. THIS EASTWARD
PROGRESSION HAS BEEN SLOWED THIS AFTERNOON BY THE PRESENCE OF
SUBSIDENCE AROUND THE PERIPHERY OF THE OFFSHORE COASTAL SYSTEM.
SR MODELS BRING THIS BOUNDARY TO SRN MAINE BY EVENING.
THE LATEST HRRR RUNS HAVE FINALLY BEGUN TO PICK UP THE BRIEF
PERIOD OF BANDED PCPN NOW FORECAST FOR THE LAST SVRL RUNS BY THE
NAM (AND TO SOME EXTENT THE GFS) TO SETTLE OVER SOUTH-CENTRAL PTNS
OF OUR FORECAST AREA THIS EVENING.
WITH A SFC LOW INTENSIFYING OFF THE CST...AND A STALLED OUT
BOUNDARY INTERACTING WITH POSITIVE VERTICAL MOTION IN THE LWR
LVLS...THIS PTTN IS BEGINNING TO RESEMBLE SOME CHARACTERISTICS OF
A NORLUN TYPE II TROUGH ("LDRI" FROM PREV NE STORM CONFERENCES). WILL
ENHANCE THE POPS FOR THIS EVENING OVER SOUTH-CENTRAL AND COASTAL AREAS
N OF PWM WHERE BEST LAPSE RATES AND MOISTURE CONVERGENCE WILL EXIST.
POPS WILL TAPER OFF AS YOU HEAD INTO WRN AND SRN NH.
QPF...WILL INCLUDE A SNOW MAP FOR THIS AFTNS AND TNGTS TOTALS.
WILL BE UPDATING THIS GRAPHIC PERIODICALLY THRU THE EVE HRS.
OTRW...PLENTY OF CLOUDS OVERNIGHT WITH THE PASSAGE OF THE UPPER
TROF. MOST OF THE PCPN TO EXIT OFF THE COAST OR DIMINISH TOWARDS MRNG.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
BY MONDAY...ANY LEFTOVER FLURRIES WILL BE CONFINED TO THE UPSLOPE
AREAS OF THE HIGHER TERRAIN IN THE NRN/WRN MTNS. USED A BLEND OF
MET/MAV MOS FOR AFTN HIGH TEMPS. TEMPS TOMORROW WILL BE RUNNING
COOLER THAN WHAT WE HAVE BEEN USED TO AS THE CORE OF THE RIDGE
KEEPS H8 TEMPS BTWN -14 AND -18 DEG C.
CYCLOGENESIS OCCURS ONCE AGAIN MONDAY NIGHT WELL OFF THE NEW
ENGLAND COASTLINE. TOO FAR OFFSHORE TO INFLUENCE OUR WX IN ME AND NH.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD OVER NEW ENGLAND ON TUESDAY BRINGING MOSTLY
SUNNY SKIES TO MUCH OF THE AREA. WILL LIKELY SEE SOME HIGH
CLOUDINESS SPILLING INTO WESTERN ZONES DURING THE AFTERNOON. HIGH
TEMPERATURES WILL REMAIN ON THE COOL SIDE WITH MID 20S TO LOWER 30S
IN THE NORTH AND LOWER TO MID 30S IN THE SOUTH.
RETURN FLOW WILL BRING WARMER AIR BACK INTO THE REGION TUESDAY NIGHT.
EXPECT VARIABLE CLOUDINESS AS AREA OF WEAK OVER-RUNNING SHIFTS INTO
THE AREA FROM THE WEST. COULD SEE A STRAY SNOW SHOWER IN THE NORTH
BUT NOT GOING WITH ANY POPS AT THIS POINT. LOOKING FOR MILDER
OVERNIGHT LOWS RANGING FROM THE LOWER TO MID TEENS IN THE NORTH
AND MID TEENS TO LOWER 20S IN THE SOUTH.
MOSTLY SUNNY WEATHER WILL CONTINUE ON WEDNESDAY AS HIGH PRESSURE
REMAINS ANCHORED OFF THE EAST COAST. ONLY LOOKING FOR A FEW PATCHY
HIGH CLOUDS WITH TEMPERATURES IN THE LOWER TO MID 40S IN THE NORTH
AND MID 40S TO LOWER 50S IN THE SOUTH.
WEAK COLD FRONT WILL SAG SOUTH FROM CANADA ON THURSDAY. SEEING SOME
RUN TO RUN TIMING DIFFERENCES ON HOW QUICKLY THIS BOUNDARY DROPS
SOUTH BUT IT SHOULD BE ANOTHER DRY AND MOSTLY SUNNY DAY IN AT LEAST
SOUTHERN ZONES. EXPECT CLOUDS TO INCREASE IN THE AFTERNOON ACROSS
THE NORTH WITH A CHANCE OF A LATE DAY SPRINKLE. HIGH TEMPERATURES
WILL AGAIN BE WELL ABOVE NORMAL WITH MID 40S TO LOWER 50S IN THE
NORTH AND RANGING THROUGH THE 50S TO NEAR 60 IN THE SOUTH.
COLD FRONT WILL PUSH SOUTH THROUGH THE REGION THURSDAY EVENING
..SHIFTING OFFSHORE BEFORE MIDNIGHT. WILL STICK WITH CHANCE POPS FOR
MUCH OF THE AREA WITH RAIN SHOWERS MIXING WITH OR CHANGING TO SNOW
SHOWERS BEFORE ENDING. SHOULD SEE CLEARING SKIES AFTER MIDNIGHT AS
HIGH PRESSURE QUICKLY BUILDS IN FROM THE WEST.
HIGH PRESSURE WILL CREST OVER THE REGION EARLY FRIDAY BEFORE MOVING
OFFSHORE. WARM FRONT CROSSING SOUTHERN CANADA WILL BRING HIGH CLOUDS
INTO THE REGION DURING THE LATE MORNING AND EARLY AFTERNOON BUT
LOOKING FOR A DRY DAY THROUGHOUT THE FORECAST AREA.
A WEAK COLD FRONT WILL DROP SOUTH FROM CANADA ON SATURDAY AND WILL
QUICKLY MOVE OFFSHORE IN THE AFTERNOON. LITTLE IF ANY MOISTURE OR
FORCING WITH THIS BOUNDAY SO AT THIS POINT SEE LITTLE MORE THAN A
FEW PASSING CLOUDS WITH THIS SYSTEM.
ANOTHER AREA OF HIGH PRESSURE WILL QUICKLY BUILD SOUTH FROM CANADA
SATURDAY NIGHT AND INTO SUNDAY KEEPING WEATHER MILD AND QUIET IN THE
NORTHEAST.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...MVFR AND LCLY IFR CONDS DVLPG THIS EVE...MAINLY OVER
S-CNTRL ME AND ALG THE MIDCOAST RGN. CONDS SLOWLY IMPROVG LATE
TNGT AND THROUGH MONDAY.
LONG TERM...VFR TUESDAY THROUGH THURSDAY. SOME AREAS OF MVFR
CEILINGS THURSDAY EVENING. VFR FRIDAY.
&&
.MARINE...
SHORT TERM...SCA HAS BEEN EXTENDED FOR THE OUTER WATERS. THERE
WILL BE A LULL IN THE WIND FIELD TNGT...HWVR...SEAS WILL RMN AOA 5
FT. NW GRADIENT TO INCREASE ONCE AGAIN ON MONDAY WITH FRQNT GUSTS
TO 25 KT CONTINUING RGT THRU MON NGT. HENCE SCAS HAVE BEEN
EXTENDED OUTWARDS IN TIME.
LONG TERM...SCA`S MAYBE NEEDED WEDNESDAY THROUGH THURSDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR ANZ150-152-154.
&&
$$
LEGRO
AREA FORECAST DISCUSSION
NWS GRAY ME
258 PM EST SUN MAR 4 2012
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL LINGER OVER NEW ENGLAND TONIGHT AND
WILL GRADUALLY GIVE WAY TO HIGH PRESSURE BUILDING IN FROM THE WEST
ON MONDAY. HIGH PRESSURE WILL CREST OVER THE REGION ON TUESDAY AND
WILL HOLD OFF THE EAST COAST THROUGH WEDNESDAY. A WEAK COLD FRONT
WILL SLOWLY APPROACH FROM THE NORTHWEST ON THURSDAY AND WILL PUSH
SOUTH THROUGH THE REGION THURSDAY EVENING. HIGH PRESSURE WILL
BUILD IN BEHIND THE FRONT THURSDAY NIGHT...SHIFTING OFFSHORE
FRIDAY AFTERNOON. A COLD FRONT WILL DROP SOUTH FROM CANADA ON
SATURDAY MOVING OFFSHORE BY LATE IN THE DAY. HIGH PRESSURE WILL
BUILD OVER NEW ENGLAND ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
INTERESTING SLOW MOVING BAND OF SHSN MOVING ACROSS NRN NEW ENG IN
ASSOC WITH COLD FRONT SETTLING SOUTHWARD. VSBL SATELLITE IMAGES
CONTINUES TO SHOW THE CONVECTIVE LOOKING CLOUDS SHIFTING SLOWLY TO
THE EAST. THIS EASTWARD PROGRESSION HAS BEEN SLOWED THIS AFTERNOON
BY THE PRESENCE OF SUBSIDENCE AROUND THE PERIPHERY OF THE OFFSHORE
COASTAL SYSTEM.
SR MODELS BRING THIS BOUNDARY TO SRN MAINE BY EVENING.
THE LATEST HRRR RUNS HAVE FINALLY BEGUN TO PICK UP THE BRIEF
PERIOD OF BANDED PCPN NOW FORECAST FOR THE LAST SVRL RUNS BY THE
NAM (AND TO SOME EXTENT THE GFS) TO SETTLE OVER SOUTH-CENTRAL PTNS
OF OUR FORECAST AREA THIS EVENING.
WITH A SFC LOW INTENSIFYING OFF THE CST...AND A STALLED OUT
BOUNDARY INTERACTING WITH POSITIVE VERTICAL MOTION IN THE LWR
LVLS...THIS PTTN IS BEGINNING TO RESEMBLE SOME CHARACTERISTICS OF
A NORLUN TYPE II TROUGH ("LDRI" FROM PREV NE STORM CONFERENCES). WILL
ENHANCE THE POPS FOR THIS EVENING OVER SOUTH-CENTRAL AND COASTAL AREAS
N OF PWM WHERE BEST LAPSE RATES AND MOISTURE CONVERGENCE WILL EXIST.
POPS WILL TAPER OFF AS YOU HEAD INTO WRN AND SRN NH.
QPF...WILL INCLUDE A SNOW MAP FOR THIS AFTNS AND TNGTS TOTALS.
WILL BE UPDATING THIS GRAPHIC PERIODICALLY THRU THE EVE HRS.
OTRW...PLENTY OF CLOUDS OVERNIGHT WITH THE PASSAGE OF THE UPPER
TROF. MOST OF THE PCPN TO EXIT OFF THE COAST OR DIMINISH TOWARDS MRNG.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
BY MONDAY...ANY LEFTOVER FLURRIES WILL BE CONFINED TO THE UPSLOPE
AREAS OF THE HIGHER TERRAIN IN THE NRN/WRN MTNS. USED A BLEND OF
MET/MAV MOS FOR AFTN HIGH TEMPS. TEMPS TOMORROW WILL BE RUNNING
COOLER THAN WHAT WE HAVE BEEN USED TO AS THE CORE OF THE RIDGE
KEEPS H8 TEMPS BTWN -14 AND -18 DEG C.
CYCLOGENESIS OCCURS ONCE AGAIN MONDAY NIGHT WELL OFF THE NEW
ENGLAND COASTLINE. TOO FAR OFFSHORE TO INFLUENCE OUR WX IN ME AND NH.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD OVER NEW ENGLAND ON TUESDAY BRINGING MOSTLY
SUNNY SKIES TO MUCH OF THE AREA. WILL LIKELY SEE SOME HIGH
CLOUDINESS SPILLING INTO WESTERN ZONES DURING THE AFTERNOON. HIGH
TEMPERATURES WILL REMAIN ON THE COOL SIDE WITH MID 20S TO LOWER 30S
IN THE NORTH AND LOWER TO MID 30S IN THE SOUTH.
RETURN FLOW WILL BRING WARMER AIR BACK INTO THE REGION TUESDAY NIGHT.
EXPECT VARIABLE CLOUDINESS AS AREA OF WEAK OVER-RUNNING SHIFTS INTO
THE AREA FROM THE WEST. COULD SEE A STRAY SNOW SHOWER IN THE NORTH
BUT NOT GOING WITH ANY POPS AT THIS POINT. LOOKING FOR MILDER
OVERNIGHT LOWS RANGING FROM THE LOWER TO MID TEENS IN THE NORTH
AND MID TEENS TO LOWER 20S IN THE SOUTH.
MOSTLY SUNNY WEATHER WILL CONTINUE ON WEDNESDAY AS HIGH PRESSURE
REMAINS ANCHORED OFF THE EAST COAST. ONLY LOOKING FOR A FEW PATCHY
HIGH CLOUDS WITH TEMPERATURES IN THE LOWER TO MID 40S IN THE NORTH
AND MID 40S TO LOWER 50S IN THE SOUTH.
WEAK COLD FRONT WILL SAG SOUTH FROM CANADA ON THURSDAY. SEEING SOME
RUN TO RUN TIMING DIFFERENCES ON HOW QUICKLY THIS BOUNDARY DROPS
SOUTH BUT IT SHOULD BE ANOTHER DRY AND MOSTLY SUNNY DAY IN AT LEAST
SOUTHERN ZONES. EXPECT CLOUDS TO INCREASE IN THE AFTERNOON ACROSS
THE NORTH WITH A CHANCE OF A LATE DAY SPRINKLE. HIGH TEMPERATURES
WILL AGAIN BE WELL ABOVE NORMAL WITH MID 40S TO LOWER 50S IN THE
NORTH AND RANGING THROUGH THE 50S TO NEAR 60 IN THE SOUTH.
COLD FRONT WILL PUSH SOUTH THROUGH THE REGION THURSDAY EVENING
..SHIFTING OFFSHORE BEFORE MIDNIGHT. WILL STICK WITH CHANCE POPS FOR
MUCH OF THE AREA WITH RAIN SHOWERS MIXING WITH OR CHANGING TO SNOW
SHOWERS BEFORE ENDING. SHOULD SEE CLEARING SKIES AFTER MIDNIGHT AS
HIGH PRESSURE QUICKLY BUILDS IN FROM THE WEST.
HIGH PRESSURE WILL CREST OVER THE REGION EARLY FRIDAY BEFORE MOVING
OFFSHORE. WARM FRONT CROSSING SOUTHERN CANADA WILL BRING HIGH CLOUDS
INTO THE REGION DURING THE LATE MORNING AND EARLY AFTERNOON BUT
LOOKING FOR A DRY DAY THROUGHOUT THE FORECAST AREA.
A WEAK COLD FRONT WILL DROP SOUTH FROM CANADA ON SATURDAY AND WILL
QUICKLY MOVE OFFSHORE IN THE AFTERNOON. LITTLE IF ANY MOISTURE OR
FORCING WITH THIS BOUNDAY SO AT THIS POINT SEE LITTLE MORE THAN A
FEW PASSING CLOUDS WITH THIS SYSTEM.
ANOTHER AREA OF HIGH PRESSURE WILL QUICKLY BUILD SOUTH FROM CANADA
SATURDAY NIGHT AND INTO SUNDAY KEEPING WEATHER MILD AND QUIET IN THE
NORTHEAST.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...MVFR AND LCLY IFR CONDS DVLPG THIS EVE...MAINLY OVER
S-CNTRL ME AND ALG THE MIDCOAST RGN. CONDS SLOWLY IMPROVG LATE
TNGT AND THROUGH MONDAY.
LONG TERM...VFR TUESDAY THROUGH THURSDAY. SOME AREAS OF MVFR
CEILINGS THURSDAY EVENING. VFR FRIDAY.
&&
.MARINE...
SHORT TERM...SCA HAS BEEN EXTENDED FOR THE OUTER WATERS. THERE
WILL BE A LULL IN THE WIND FIELD TNGT...HWVR...SEAS WILL RMN AOA 5
FT. NW GRADIENT TO INCREASE ONCE AGAIN ON MONDAY WITH FRQNT GUSTS
TO 25 KT CONTINUING RGT THRU MON NGT. HENCE SCAS HAVE BEEN
EXTENDED OUTWARDS IN TIME.
LONG TERM...SCA`S MAYBE NEEDED WEDNESDAY THROUGH THURSDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR ANZ150-152-154.
&&
$$
SHORT TERM...CANNON
AREA FORECAST DISCUSSION
NWS GRAY ME
216 PM EST SUN MAR 4 2012
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL LINGER OVER NEW ENGLAND TONIGHT AND
WILL GRADUALLY GIVE WAY TO HIGH PRESSURE BUILDING IN FROM THE WEST
ON MONDAY. HIGH PRESSURE WILL CREST OVER THE REGION ON TUESDAY AND
WILL HOLD OFF THE EAST COAST THROUGH WEDNESDAY. A WEAK COLD FRONT
WILL SLOWLY APPROACH FROM THE NORTHWEST ON THURSDAY AND WILL PUSH
SOUTH THROUGH THE REGION THURSDAY EVENING. HIGH PRESSURE WILL
BUILD IN BEHIND THE FRONT THURSDAY NIGHT...SHIFTING OFFSHORE
FRIDAY AFTERNOON. A COLD FRONT WILL DROP SOUTH FROM CANADA ON
SATURDAY MOVING OFFSHORE BY LATE IN THE DAY. HIGH PRESSURE WILL
BUILD OVER NEW ENGLAND ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
INTERESTING SLOW MOVING BAND OF SHSN MOVING ACROSS NRN NEW ENG IN
ASSOC WITH COLD FRONT SETTLING SOUTHWARD. VSBL SATELLITE IMAGES
CONTINUE TO SHOW THE CONVECTIVE LOOKING CLOUDS SHIFTING SLOWLY TO
THE EAST. THIS EASTWARD PROGRESSION HAS BEEN SLOWED THIS AFTERNOON
BY THE PRESENCE OF SUBSIDENCE AROUND THE PERIPHERY OF THE OFFSHORE
COASTAL SYSTEM.
SR MODELS BRING THIS BOUNDARY TO SRN MAINE BY EVENING.
UNFORTUNATELY...THE LATEST HRRR RUNS HAVE NOT PICKED UP ON THE
PCPN (ALBIET LGT) NOW FORECAST FOR THE LAST SVRL RUNS BY THE NAM
(AND TO SOME EXTENT THE GFS) TO SETTLE OVER SOUTH-CENTRAL PTNS OF
OUR FORECAST AREA THIS EVENING.
WITH A SFC LOW INTENSIFYING OFF THE CST...AND A STALLED OUT
BOUNDARY INTERACTING WITH POSITIVE VERTICAL MOTION IN THE LWR
LVLS...THIS PTTN IS BEGINNING TO RESEMBLE SOME CHARACTERISTICS OF
A NORLUN TYPE II TROUGH ("LDRI" FROM PREV NE STORM CONFERENCES). WILL
ENHANCE THE POPS FOR THIS EVENING OVER SOUTH-CENTRAL AND COASTAL AREAS
N OF PWM WHERE BEST LAPSE RATES AND MOISTURE CONVERGENCE WILL EXIST.
POPS WILL TAPER OFF AS YOU HEAD INTO WRN AND SRN NH.
QPF...WILL INCLUDE A SNOW MAP FOR THIS AFTNS AND TNGTS TOTALS.
WILL BE UPDATING THIS GRAPHIC PERIODICALLY THRU THE EVE HRS. FOR
NOW...IT APPEARS ACCUMS WL BE LGT...GENERALLY AN INCH OR LESS OVR
THE NRN 2/3 OF THE FA...WITH A MAX OF 1-2" N AND E OF PWM.
OTRW...PLENTY OF CLOUDS OVERNIGHT WITH THE PASSAGE OF THE UPPER
TROF. MOST OF THE PCPN TO EXIT OFF THE COAST OR DIMINISH TOWARDS MRNG.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
BY MONDAY...ANY LEFTOVER FLURRIES WILL BE CONFINED TO THE UPSLOPE
AREAS OF THE HIGHER TERRAIN IN THE NRN/WRN MTNS. USED A BLEND OF
MET/MAV MOS FOR AFTN HIGH TEMPS. TEMPS TOMORROW WILL BE RUNNING
COOLER THAN WHAT WE HAVE BEEN USED TO AS THE CORE OF THE RIDGE
KEEPS H8 TEMPS BTWN -14 AND -18 DEG C.
CYCLOGENESIS OCCURS ONCE AGAIN MONDAY NIGHT WELL OFF THE NEW
ENGLAND COASTLINE. TOO FAR OFFSHORE TO INFLUENCE OUR WX IN ME AND NH.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD OVER NEW ENGLAND ON TUESDAY BRINGING MOSTLY
SUNNY SKIES TO MUCH OF THE AREA. WILL LIKELY SEE SOME HIGH
CLOUDINESS SPILLING INTO WESTERN ZONES DURING THE AFTERNOON. HIGH
TEMPERATURES WILL REMAIN ON THE COOL SIDE WITH MID 20S TO LOWER 30S
IN THE NORTH AND LOWER TO MID 30S IN THE SOUTH.
RETURN FLOW WILL BRING WARMER AIR BACK INTO THE REGION TUESDAY NIGHT.
EXPECT VARIABLE CLOUDINESS AS AREA OF WEAK OVER-RUNNING SHIFTS INTO
THE AREA FROM THE WEST. COULD SEE A STRAY SNOW SHOWER IN THE NORTH
BUT NOT GOING WITH ANY POPS AT THIS POINT. LOOKING FOR MILDER
OVERNIGHT LOWS RANGING FROM THE LOWER TO MID TEENS IN THE NORTH
AND MID TEENS TO LOWER 20S IN THE SOUTH.
MOSTLY SUNNY WEATHER WILL CONTINUE ON WEDNESDAY AS HIGH PRESSURE
REMAINS ANCHORED OFF THE EAST COAST. ONLY LOOKING FOR A FEW PATCHY
HIGH CLOUDS WITH TEMPERATURES IN THE LOWER TO MID 40S IN THE NORTH
AND MID 40S TO LOWER 50S IN THE SOUTH.
WEAK COLD FRONT WILL SAG SOUTH FROM CANADA ON THURSDAY. SEEING SOME
RUN TO RUN TIMING DIFFERENCES ON HOW QUICKLY THIS BOUNDARY DROPS
SOUTH BUT IT SHOULD BE ANOTHER DRY AND MOSTLY SUNNY DAY IN AT LEAST
SOUTHERN ZONES. EXPECT CLOUDS TO INCREASE IN THE AFTERNOON ACROSS
THE NORTH WITH A CHANCE OF A LATE DAY SPRINKLE. HIGH TEMPERATURES
WILL AGAIN BE WELL ABOVE NORMAL WITH MID 40S TO LOWER 50S IN THE
NORTH AND RANGING THROUGH THE 50S TO NEAR 60 IN THE SOUTH.
COLD FRONT WILL PUSH SOUTH THROUGH THE REGION THURSDAY EVENING
..SHIFTING OFFSHORE BEFORE MIDNIGHT. WILL STICK WITH CHANCE POPS FOR
MUCH OF THE AREA WITH RAIN SHOWERS MIXING WITH OR CHANGING TO SNOW
SHOWERS BEFORE ENDING. SHOULD SEE CLEARING SKIES AFTER MIDNIGHT AS
HIGH PRESSURE QUICKLY BUILDS IN FROM THE WEST.
HIGH PRESSURE WILL CREST OVER THE REGION EARLY FRIDAY BEFORE MOVING
OFFSHORE. WARM FRONT CROSSING SOUTHERN CANADA WILL BRING HIGH CLOUDS
INTO THE REGION DURING THE LATE MORNING AND EARLY AFTERNOON BUT
LOOKING FOR A DRY DAY THROUGHOUT THE FORECAST AREA.
A WEAK COLD FRONT WILL DROP SOUTH FROM CANADA ON SATURDAY AND WILL
QUICKLY MOVE OFFSHORE IN THE AFTERNOON. LITTLE IF ANY MOISTURE OR
FORCING WITH THIS BOUNDAY SO AT THIS POINT SEE LITTLE MORE THAN A
FEW PASSING CLOUDS WITH THIS SYSTEM.
ANOTHER AREA OF HIGH PRESSURE WILL QUICKLY BUILD SOUTH FROM CANADA
SATURDAY NIGHT AND INTO SUNDAY KEEPING WEATHER MILD AND QUIET IN THE
NORTHEAST.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...MVFR AND LCLY IFR CONDS DVLPG THIS EVE...MAINLY OVER
S-CNTRL ME AND ALG THE MIDCOAST RGN. CONDS SLOWLY IMPROVG LATE
TNGT AND THROUGH MONDAY.
LONG TERM...VFR TUESDAY THROUGH THURSDAY. SOME AREAS OF MVFR
CEILINGS THURSDAY EVENING. VFR FRIDAY.
&&
.MARINE...
SHORT TERM...SCA HAS BEEN EXTENDED FOR THE OUTER WATERS. THERE
WILL BE A LULL IN THE WIND FIELD TNGT...HWVR...SEAS WILL RMN AOA 5
FT. NW GRADIENT TO INCREASE ONCE AGAIN ON MONDAY WITH FRQNT GUSTS
TO 25 KT CONTINUING RGT THRU MON NGT. HENCE SCAS HAVE BEEN
EXTENDED OUTWARDS IN TIME.
LONG TERM...SCA`S MAYBE NEEDED WEDNESDAY THROUGH THURSDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR ANZ150-152-154.
&&
$$
JC
AREA FORECAST DISCUSSION
NWS GRAY ME
1156 AM EST SUN MAR 4 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH ACROSS THE REGION TODAY ACCOMPANIED
BY A FEW CLOUDS AND SCATTERED SNOW SHOWERS ACROSS THE HIGHER TERRAIN. AN
UPPER TROUGH WILL PRODUCE MORE WIDESPREAD CLOUDS AND SCATTERED SNOW
SHOWERS TONIGHT AND MONDAY. HIGH PRESSURE WILL BUILD TO THE SOUTH
OF THE AREA TUESDAY INTO THURSDAY. A COLD FRONT WILL CROSS THE
REGION THURSDAY NIGHT AND FRIDAY. HIGH PRESSURE FOLLOWS THIS FRONT
FOR NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
INTERESTING SLOW MOVING BAND OF SHSN MOVING ACROSS NRN NEW ENG IN
ASSOC WITH COLD FRONT SETTLING SOUTHWARD. VSBL SATELLITE IMAGES
CONTINUES TO SHOW THE CONVECTIVE LOOKING CLOUDS SHIFTING SLOWLY TO
THE EAST.
SR MODELS BRING THIS BOUNDARY TO SRN MAINE BY EVENING.
UNFORTUNATELY...THE LATEST HRRR RUNS HAVE NOT PICKED UP ON THE
PCPN NOW FORECAST FOR THE LAST SVRL RUNS BY THE NAM TO SETTLE OVER
OUR FORECAST AREA OVERNIGHT.
WITH A SFC LOW INTENSIFYING OFF THE CST...AND A STALLED OUT
BOUNDARY WITH GOOD VERTICAL MOTION IN THE LWR LVLS...THIS PTTN IS
BEGINNING TO RESEMBLE SOME CHARACTERISTICS OF A NORLUN TYPE II
TROUGH (LDRI). WILL ENHANCE THE POPS FOR THIS AFTN AND TNGT OVER
THE NRN 2/3 OF THE FCST AREA...ALBIET...THE CHC FOR PCPN AWAY FROM
THE COAST (NH) WILL NOT BE AS HIGH AS OTHER AREAS NEAR THE
SHORELINE FROM ABOUT PWM NORTH.
QPF...WILL INCLUDE A SNOW MAP FOR THIS AFTNS AND TNGTS TOTALS.
WILL BE UPDATING THIS GRAPHIC THROUGHOUT THE AFTN.
REST OF THE GRIDS WILL REMAIN RELATIVELY UNCHANGED AT THIS TIME.
PREV DISC...
A 985 MILLIBAR LOW WAS VICINITY OF GASPE PENINSULA WITH TRAILING
COLD FRONT EXTENDING THROUGH SAINT LAWRENCE VALLEY AND EASTERN
LAKES AS OF 07Z. THE FRONT WILL DROP SOUTH ACROSS THE FORECAST
AREA TODAY WITH A FEW CLOUDS AND SCATTERED SNOW SHOWERS ACROSS THE
HIGHER TERRAIN. WE`LL SEE SEASONABLE HIGHS OF NEAR 30 FOR THE
MOUNTAINS AND AROUND 40 FOR THE COASTAL PLAIN.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
TURNING COLDER TONIGHT AND MONDAY AS THE COLD FRONT EXITS THE
COAST AND OFFSHORE STORM DRAWS COLDER AIR SOUTHWARD INTO THE
AREA. IT WILL BE UNSETTLED AS WELL AS AN UPPER TROUGH CROSSES THE
REGION WITH CLOUDS AND SCATTERED SNOW SHOWERS. LOWS TONIGHT WILL
BE SINGLE NUMBERS AND TEENS...WITH BELOW NORMAL HIGHS ON MONDAY
RANGING FROM 20 TO 30 ACROSS THE AREA.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS THE UPPER TROUGH MOVES EAST OF THE AREA MONDAY NIGHT...HIGH
PRESSURE BUILDS INTO THE REGION FROM THE WEST. THIS WILL ALLOW FOR
CLEARING AND CHILLY OVERNIGHT TEMPERATURES. THE RIDGE MOVES OFF
THE COAST TUESDAY ALLOWING A SOUTHWEST FLOW TO DEVELOP AHEAD OF AN
APPROACHING COLD FRONT. WARM ADVECTION ON THE BACK SIDE OF THE
HIGH WILL PRODUCE HIGH CLOUDS ACROSS THE AREA...ESPECIALLY IN THE
MTNS TUESDAY NIGHT. WEDNESDAY SHOULD BE SUNNY AND MILD. MODELS ARE
IN GOOD AGREEMENT THROUGH WEDNESDAY.
AFTER WEDNESDAY THOUGH...MODELS HAVE NOT BEEN IN GOOD AGREEMENT
LEADING TO CONSIDERABLE UNCERTAINTY. AT THIS TIME...BOTH THE 00Z GFS
AND 00Z ECMWF ARE BRINGING THE COLD FRONT THROUGH THURSDAY NIGHT.
IN COMPARISON...YESTERDAY`S 12Z ECMWF WAS ABOUT 48 HOURS SLOWER.
HOWEVER...THE LATEST ECMWF DEVELOPS A LOW ALONG THE COAST FRIDAY
AND TAKES IT THROUGH THE GULF OF MAINE DURING THE DAY. THIS IS A
NEW WRINKLE IN WHAT HAVE BEEN RATHER DIVERGENT MODEL RUNS. IN
COMPARISON...THE GFS BRINGS A LARGE AREA OF HIGH PRESSURE
SOUTHWARD AND JUST PUSHES THE FRONT AND MOISTURE SOUTHEAST OF THE
AREA DURING THE DAY. CONSIDERING THE UNCERTAINTY...EXPECT A
CHANCE OF RAIN SHOWERS THURSDAY AFTERNOON AND EVENING FOLLOWED BY
THE CHANCE OF RAIN OR SNOW SHOWERS FOR SATURDAY. SOUTHWARD
PROGRESSION OF RAIN/SNOW LINE (IF ANY) ON SATURDAY WILL DEPEND ON
STRENGTH OF SURFACE LOW (IF ANY) IN THE GULF OF MAINE. WEATHER
CONDITIONS SHOULD IMPROVE SUNDAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 23Z MON/...VFR EXPECTED.
LONG TERM...VFR CONDITIONS THROUGH WEDNESDAY NIGHT. MVFR
CONDITIONS EXPECTED THURSDAY IN CLOUDS AND SHOWERS.
&&
.MARINE...
SHORT TERM /THROUGH MONDAY/...SCA CONTINUES TODAY OUTSIDE THE BAYS MAINLY
FOR SEAS...ALTHOUGH WE WILL SEE SEVERAL MORE HOURS OF SCA GUSTS AT
THE ELEVATED PLATFORMS. WE WILL DROP BELOW SCA THRESHOLD TONIGHT
INTO MONDAY.
LONG TERM...SCA MAY BE REQUIRED FOR WIND GUSTS TO 25 KT MONDAY
NIGHT INTO TUESDAY AS OCEAN LOW PASSES WELL TO THE SOUTHEAST OF
THE WATERS AND LATER IN THE WEEK AS SW WINDS AND SEAS INCREASE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ150-
152-154.
&&
$$
JC
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
337 PM EST SUN MAR 4 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTHWARD ACROSS THE AREA AND BRING
SNOW SHOWERS TO THE AREA TONIGHT. HIGH PRESSURE WILL THEN BUILD
INTO THE REGION BY LATE MONDAY AND CONTINUE THROUGH THE MID-WEEK.
THE CHANCE OF RAIN WILL RETURN BY LATE WEEK AS THE NEXT FRONT
APPROACHES FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH AXIS
EXTENDING ACROSS THE UPPER OHIO VALLEY. AT 850MB, FLOW HAS BECOME
NORTHWESTERLY WITH TEMPS COOLING TO AROUND -10C ACROSS LAKE ERIE.
WITH INVERSION HEIGHTS ABOVE 8KFT, THIS HAS ALLOWED FOR SNOW
SHOWERS TO DEVELOP WITH A FEW HEAVIER SNOW SQUALLS.
TONIGHT...NORTHWESTERLY 850MB FLOW WILL ALLOW FOR SNOW SHOWERS TO
CONTINUE. COLD AIR ADVECTION WILL BE REINFORCED THIS AFTERNOON AS
ANOTHER COLD FRONT SLIDES SOUTHWARD INTO THE AREA. THIS IS MOST
INDICATIVE BY A WIND SHIFT FROM WEST-SOUTHWESTERLY TO
NORTHWESTERLY. SOME LOW-LEVEL CONVERGENCE ALONG THE WIND-SHIFT
WILL ALLOW FOR HEAVIER SNOW SHOWERS TO CONTINUE TO SLIDE SOUTHWARD
WITH THE FRONT INTO THE EVENING.
WITH SNOW SHOWERS AND SQUALLS, A QUICK HALF INCH TO AN INCH WILL
BE POSSIBLE. NOT OUT OF THE QUESTION THAT SOME LOCATIONS THAT GET
MULTIPLE SNOW SQUALLS AND THE HIGHER ELEVATIONS MAY GET UP TO 2
INCHES. ELSEWHERE, EXPECT GENERALLY LESS THAN AN INCH. SNOW
SHOWERS WILL DIMINISH IN COVERAGE AND INTENSITY TONIGHT, WITH LESS
THAN AN ADDITIONAL INCH POSSIBLE ACROSS THE AREA. TEMPERATURES ARE
FAIRLY CLOSE TO LAMP GUIDANCE, AROUND 5 TO 10 DEGREES BELOW
NORMAL.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
THERE IS GFS/ECMWF AGREEMENT THAT A COLD FRONT WILL SLIDE SOUTH
OF THE AREA AS A CLIPPER SYSTEM PASSES FROM KENTUCKY INTO
SOUTHERN WEST VIRGINIA. HAVE BEGUN THE PERIOD WITH CHANCE POPS
ACROSS THE SOUTH AND LIKELY IN THE RIDGES AS FRONTAL BOUNDARY WILL
SERVE AS A FOCUS FOR SNOW SHOWERS INTIALLY. SNOW SHOWERS WILL
DIMINISH BY 18Z ACROSS MUCH OF THE AREA AS HIGH PRESSURE RIDGING
BEGINS TO APPROACH FROM THE WEST. HIGH TEMPS ARE CLOSER TO THE
WARMER MAV GUIDANCE, AROUND 10 DEGREES BELOW NORMAL.
MONDAY NIGHT THROUGH WEDNESDAY...SURFACE HIGH PRESSURE RIDGE WILL
MOVE ACROSS THE AREA ON TUESDAY AND BE CENTERED OFF THE MID-
ATLANTIC COAST BY WEDNESDAY. THIS WILL ALLOW FOR ABUNDANT SUNSHINE
THROUGH THIS PERIOD WITH TEMPERATURES MODERATING EACH DAY AS THE
FLOW SHIFTS TO MORE SOUTHERLY. HIGHS ON TUESDAY ARE A FEW DEGREES
WARMER THAN A MAV/MET BLEND, AROUND 5 DEGREES ABOVE NORMAL.
SOUTHERLY FLOW WILL ALLOW FOR TEMPS TO WARM TO AROUND 15 DEGREES
ABOVE NORMAL ON WEDNESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
COLD FRONT WILL CROSS THE GREAT LAKES THURSDAY. PRECIPITATION SHOULD
REACH ALMOST ALL LOCATIONS BY THURSDAY EVENING...AND HAVE BUMPED UP
POPS EVERYWHERE TO HIGH CHANCE. MULTIPLE RUNS OF GFS CONTINUE TO
FLIP-FLOP WITH ORIENTATION OF FRONT AND THEREFORE LOCATION OF
PRECIPITATION...BUT ECMWF HAS REMAINED CONSISTENT OVER SEVERAL RUNS
ALONG WITH GFS AND CANADIAN ENSEMBLES IN SHOWING THE FRONT SLOWLY
MOVING FROM NORTHWEST TO SOUTHEAST THURSDAY NIGHT INTO FRIDAY NIGHT.
HAVE STUCK WITH THE ECMWF SOLUTION AT THIS POINT. THIS SHOWS HIGH
PRESSURE BUILDING INTO THE GREAT LAKES FRIDAY NIGHT...AND ALLOWING
FOR DRY WEATHER SATURDAY AND SUNDAY. BULK OF PRECIPITATION SHOULD
FALL AS RAIN...BUT CANNOT RULE OUT SOME FLAKES MIXING IN AS PRECIP
ENDS FRIDAY NIGHT. TEMPERATURES WILL BE ABOVE NORMAL AHEAD OF
THURSDAY/S COLD FRONT...WITH NEAR NORMAL TEMPERATURES FOR THE
WEEKEND.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
LIGHT SNOW SHOWERS ARE POSSIBLE THROUGH THE DAY AT ALL SITES...WITH
VISIBILITIES ONLY EXPECTED TO DROP TO 5-6 MILES FOR MOST OF THE DAY.
ONE DOMINANT SNOW BAND HAS BEEN SLOWLY MOVING FROM NORTH TO
SOUTH...HAVING ALREADY PASSED FKL AND DUJ. CONSIDERING THE BAND IS
ONLY MOVING AROUND 10-20 MILES AN HOUR...HAVE NOT INCLUDED TEMPOS
4-8 HOURS OUT FOR THIS BAND. HAVE INCLUDED SOME TEMPO GROUPS FROM
18-21Z FOR A MORE MODERATE BAND MOVING ACROSS THE WV PANHANDLE INTO
SOUTHWEST PA. DOMINANT BAND COULD POSSIBLY AFFECT PITTSBURGH AND
TERMINALS TO THE SOUTH DURING THE EVENING HOURS IF IT HOLDS
TOGETHER. TERMINALS SHOULD EVENTUALLY GO VFR DURING THE OVERNIGHT
HOURS.
OUTLOOK...MONDAY THROUGH FRIDAY...
HIGH PRESSURE BUILDS IN THE AREA MONDAY AFTERNOON AND CONTINUES TO
DOMINATE THE WEATHER THROUGH THURSDAY WITH VFR CONDITIONS. NEXT
FRONT APPROACHES LATE THURSDAY WITH MVFR AND SCATTERED IFR IN
SHOWERS...WITH PRECIPITATION PERSISTING INTO FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
120 PM EST SUN MAR 4 2012
.SYNOPSIS...
SNOW SHOWERS AND COLD WEATHER WILL BE THE RULE THIS AFTERNOON AND
TONIGHT AS A SECONDARY COLD FRONT PUSHES SOUTHEAST FROM CANADA.
HIGH PRESSURE WILL BUILD INTO THE AREA BY LATE MONDAY AND CONTINUE
THROUGH THE MID-WEEK WITH THE NEXT CHANCE OF RAIN BY LATE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED
TO INCREASE POPS TO CATEGORICAL AS HEAVIER SNOW SHOWERS DROP SOUTH
ACROSS THE AREA THIS EVENING. THE PREVIOUS DISCUSSION FOLLOWS.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH AXIS
EXTENDING FROM MICHIGAN SOUTHWARD INTO THE TENNESSEE VALLEY WITH
THE UPPER OHIO VALLEY IN A WEST-SOUTHWESTERLY FLOW AHEAD OF THIS
FEATURE. AT 850MB, FLOW HAS BECOME MORE WEST-NORTHWESTERLY WITH
TEMPS COOLING TO AROUND -10C. WITH INVERSION HEIGHTS ABOVE 8KFT
AND MID-LEVEL VORT ENERGY SLIDING INTO THE I-80 CORRIDOR, THIS HAS
ALLOWED FOR SNOW SHOWERS TO DEVELOP WITH A FEW HEAVIER SNOW
SQUALLS.
THIS AFTERNOON AND TONIGHT...THE WEST-NORTHWESTERLY FLOW AT 850MB
WILL SHIFT TO MORE NORTHWESTERLY AND ALLOW FOR SNOW SHOWERS. COLD
AIR ADVECTION WILL BE REINFORCED THIS AFTERNOON AS ANOTHER COLD
FRONT SLIDES SOUTHWARD INTO THE AREA. THIS IS MOST INDICATIVE BY A
WIND SHIFT FROM WEST-SOUTHWESTERLY TO NORTHWESTERLY. SOME LOW-
LEVEL CONVERGENCE ALONG THE WIND-SHIFT WILL ALLOW FOR HEAVIER SNOW
SQUALLS TO CONTINUE TO SLIDE SOUTHWARD WITH THE FRONT INTO THE
EVENING.
IN THIS SETUP, HAVE ALREADY OBSERVED A FEW HIGH IMPACT SUB-
ADVISORY (HISA) SNOW SQUALLS ACROSS THE I-80 CORRIDOR AND EXPECT
THIS TO CONTINUE THROUGH THE AFTERNOON. WITH SNOW SHOWERS AND
SQUALLS, A QUICK HALF INCH TO AN INCH WILL BE POSSIBLE. NOT OUT OF
THE QUESTION THAT SOME LOCATIONS THAT GET MULTIPLE SNOW SQUALLS
MAY AND THE HIGHER ELEVATIONS WILL GET UP TO 2 INCHES. ELSEWHERE,
EXPECT GENERALLY LESS THAN AN INCH. SNOW SHOWERS WILL DIMINISH IN
COVERAGE AND INTENSITY TONIGHT, WITH LESS THAN AN ADDITIONAL INCH
POSSIBLE ACROSS THE AREA. TEMPERATURES ARE FAIRLY CLOSE TO LAMP
GUIDANCE, ARUOND 5 TO 10 DEGREES BELOW NORMAL.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
ALL OF THE WX TAKES PLACE RIGHT OUT OF THE GATE MON AS A STRONG
SHORTWAVE TROUGH INTERACTS WITH SUFFICIENT LLVL MOISTURE IN THE
RIDGES. INCREASED POPS TO LKLY FOR GARRETT AND TUCKER COUNTIES
WITH CHC NUMBERS FOR ADJACENT LOCATIONS. ANY DAYTIME SNOW ACCUM
WILL BE AN INCH OR LESS. WINTER PCPN QUICKLY ENDS MON EVENING AS
MID LEVEL ENERGY MOVES EAST. DRY WEATHER IS ANTICIPATED THE
BALANCE OF THE SHORT TERM AS HIGH PRESSURE CONTROLS OUR WEATHER.
TEMPERATURES WILL GET WARMER EACH SUCCESSIVE DAY / NIGHT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
0Z RUNS ARE STRONGER WITH MID WEEK SE CONUS ANTICYCLONE THEREBY
DELAY FROPA 12-24HRS FROM PREVIOUS RUNS. AS A RESULT...CONTINUED
DRY WEATHER THROUGH WEDNESDAY NIGHT INTO EARLY THURSDAY MRNG.
TEMPERATURES WILL BE AFFECTED AS WELL. OVERNIGHT LOWS WED NGT WILL
BE QUITE WARM UNDER A WELL MIXED BOUNDARY LAYER WITH MOST LOCATIONS
STAYING WELL INTO THE 40S AND LOWER 50S. THURSDAY WILL BE THE
WARMEST DAY OF THE WEEK AS LWR 60S SHOULD BE OBSERVED FROM ZZV - IDI
AND POINTS S.
DO NOT EXPECT CONVECTIVE ACTIVITY WITH COLD FRONT THURSDAY DESPITE
CURRENT AFTERNOON TIMING. STILL LOTS OF UNCERTAINTY WITH THE BACK
END OF THE FORECAST. ECMWF CONTS TO BRING A FULL LATITUDE TROF OVER
THE ERN U.S. RESULTING IN SCT SHSN FRI INTO SAT...WHILE GFS IS MORE
PROGRESSIVE AS PCPN SHUTS OFF FRI AND SEASONAL DRY WX SAT. DID
NOT MAKE ANY CHANGES TO GRIDDED DATA SET DAY 6 AND 7 DUE TO LOW
CONFIDENCE.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
LIGHT SNOW SHOWERS ARE POSSIBLE THROUGH THE DAY AT ALL SITES...WITH
VISIBILITIES ONLY EXPECTED TO DROP TO 5-6 MILES FOR MOST OF THE DAY.
ONE DOMINANT SNOW BAND HAS BEEN SLOWLY MOVING FROM NORTH TO
SOUTH...HAVING ALREADY PASSED FKL AND DUJ. CONSIDERING THE BAND IS
ONLY MOVING AROUND 10-20 MILES AN HOUR...HAVE NOT INCLUDED TEMPOS
4-8 HOURS OUT FOR THIS BAND. HAVE INCLUDED SOME TEMPO GROUPS FROM
18-21Z FOR A MORE MODERATE BAND MOVING ACROSS THE WV PANHANDLE INTO
SOUTHWEST PA. DOMINANT BAND COULD POSSIBLY AFFECT PITTSBURGH AND
TERMINALS TO THE SOUTH DURING THE EVENING HOURS IF IT HOLDS
TOGETHER. TERMINALS SHOULD EVENTUALLY GO VFR DURING THE OVERNIGHT
HOURS.
OUTLOOK...MONDAY THROUGH FRIDAY...
HIGH PRESSURE BUILDS IN THE AREA MONDAY AFTERNOON AND CONTINUES TO
DOMINATE THE WEATHER THROUGH THURSDAY WITH VFR CONDITIONS. NEXT
FRONT APPROACHES LATE THURSDAY WITH MVFR AND SCATTERED IFR IN
SHOWERS...WITH PRECIPITATION PERSISTING INTO FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1104 AM EST SUN MAR 4 2012
.SYNOPSIS...
SNOW SHOWERS AND COLD WEATHER WILL BE THE RULE THIS AFTERNOON AND
TONIGHT AS A SECONDARY COLD FRONT PUSHES SOUTHEAST FROM CANADA.
HIGH PRESSURE WILL BUILD INTO THE AREA BY LATE MONDAY AND CONTINUE
THROUGH THE MID-WEEK WITH THE NEXT CHANCE OF RAIN BY LATE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
A LATE MORNING ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED
TO UPDATE THE LATEST TRENDS IN SKY AND POPS.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH AXIS
EXTENDING FROM MICHIGAN SOUTHWARD INTO THE TENNESSEE VALLEY WITH
THE UPPER OHIO VALLEY IN A WEST-SOUTHWESTERLY FLOW AHEAD OF THIS
FEATURE. AT 850MB, FLOW HAS BECOME MORE WEST-NORTHWESTERLY WITH
TEMPS COOLING TO AROUND -10C. WITH INVERSION HEIGHTS ABOVE 8KFT
AND MID-LEVEL VORT ENERGY SLIDING INTO THE I-80 CORRIDOR, THIS HAS
ALLOWED FOR SNOW SHOWERS TO DEVELOP WITH A FEW HEAVIER SNOW
SQUALLS.
THIS AFTERNOON AND TONIGHT...THE WEST-NORTHWESTERLY FLOW AT 850MB
WILL SHIFT TO MORE NORTHWESTERLY AND ALLOW FOR SNOW SHOWERS. COLD
AIR ADVECTION WILL BE REINFORCED THIS AFTERNOON AS ANOTHER COLD
FRONT SLIDES SOUTHWARD INTO THE AREA. THIS IS MOST INDICATIVE BY A
WIND SHIFT FROM WESTERLY TO NORTHWESTERLY. SOME LOW-LEVEL
CONVERGENCE ALONG THE WIND-SHIFT WILL ALLOW FOR HEAVIER
SNOW SQUALLS TO DEVELOP AND SLIDE SOUTHWARD WITH THE FRONT INTO
THE EVENING.
IN THIS SETUP, HAVE ALREADY OBSERVED A FEW HIGH IMPACT SUB-
ADVISORY (HISA) SNOW SQUALLS ACROSS THE I-80 CORRIDOR AND EXPECT
THIS TO CONTINUE THROUGH THE AFTERNOON. WITH SNOW SHOWERS AND
SQUALLS, A QUICK HALF INCH WILL BE POSSIBLE. NOT OUT OF THE
QUESTION THAT SOME LOCATIONS THAT GET MULTIPLE SNOW SQUALLS MAY
AND THE HIGHER ELEVATIONS WILL GET UP TO 2 INCHES. ELSEWHERE,
EXPECT GENERALLY LESS THAN AN INCH. SNOW SHOWERS WILL DIMINISH IN
COVERAGE AND INTENSITY TONIGHT, WITH LESS THAN AN ADDITIONAL INCH
POSSIBLE ACROSS THE AREA. TEMPERATURES ARE FAIRLY CLOSE TO LAMP
GUIDANCE, ARUOND 5 TO 10 DEGREES BELOW NORMAL.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
ALL OF THE WX TAKES PLACE RIGHT OUT OF THE GATE MON AS A STRONG
SHORTWAVE TROUGH INTERACTS WITH SUFFICIENT LLVL MOISTURE IN THE
RIDGES. INCREASED POPS TO LKLY FOR GARRETT AND TUCKER COUNTIES
WITH CHC NUMBERS FOR ADJACENT LOCATIONS. ANY DAYTIME SNOW ACCUM
WILL BE AN INCH OR LESS. WINTER PCPN QUICKLY ENDS MON EVENING AS
MID LEVEL ENERGY MOVES EAST. DRY WEATHER IS ANTICIPATED THE
BALANCE OF THE SHORT TERM AS HIGH PRESSURE CONTROLS OUR WEATHER.
TEMPERATURES WILL GET WARMER EACH SUCCESSIVE DAY / NIGHT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
0Z RUNS ARE STRONGER WITH MID WEEK SE CONUS ANTICYCLONE THEREBY
DELAY FROPA 12-24HRS FROM PREVIOUS RUNS. AS A RESULT...CONTINUED
DRY WEATHER THROUGH WEDNESDAY NIGHT INTO EARLY THURSDAY MRNG.
TEMPERATURES WILL BE AFFECTED AS WELL. OVERNIGHT LOWS WED NGT WILL
BE QUITE WARM UNDER A WELL MIXED BOUNDARY LAYER WITH MOST LOCATIONS
STAYING WELL INTO THE 40S AND LOWER 50S. THURSDAY WILL BE THE
WARMEST DAY OF THE WEEK AS LWR 60S SHOULD BE OBSERVED FROM ZZV - IDI
AND POINTS S.
DO NOT EXPECT CONVECTIVE ACTIVITY WITH COLD FRONT THURSDAY DESPITE
CURRENT AFTERNOON TIMING. STILL LOTS OF UNCERTAINTY WITH THE BACK
END OF THE FORECAST. ECMWF CONTS TO BRING A FULL LATITUDE TROF OVER
THE ERN U.S. RESULTING IN SCT SHSN FRI INTO SAT...WHILE GFS IS MORE
PROGRESSIVE AS PCPN SHUTS OFF FRI AND SEASONAL DRY WX SAT. DID
NOT MAKE ANY CHANGES TO GRIDDED DATA SET DAY 6 AND 7 DUE TO LOW
CONFIDENCE.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
LIGHT SNOW SHOWERS ARE POSSIBLE THROUGH THE DAY AT ALL SITES...WITH
VISIBILITIES ONLY EXPECTED TO DROP TO 5-6 MILES FOR MOST OF THE DAY.
HEAVIER SNOW BANDS COULD DROP VISIBILITIES TO 1-2 MILES...WITH A
SINGLE BAND LIKELY TO MOVE FROM NORTH TO SOUTH DURING THE DAY. SOME
15-20 GUSTS ARE POSSIBLE DURING THE DAY...BUT WINDS WILL NOT BE
NEARLY AS STRONG AS YESTERDAY. SNOW SHOULD DIMINISH BY THE END OF
THE EVENING.
OUTLOOK...MONDAY THROUGH THURSDAY...
HIGH PRESSURE BUILDS IN THE AREA ON MONDAY AND CONTINUES TO DOMINATE
THE WEATHER THROUGH THURSDAY WITH VFR CONDITIONS. NEXT FRONT
APPROACHES ON THURSDAY WITH MVFR AND SCATTERED IFR IN SHOWERS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
1228 PM CST SUN MAR 4 2012
.UPDATE...CANCELED ADVISORY FOR DULUTH AREA AS MAIN LAKE EFFECT
SNOW BAND HAS MOVED NORTH OVER SWRN LAKE COUNTY NEAR THE TWO
HARBORS/GOOSEBERRY FALLS AREA. THIS LAKE EFFECT SNOW BAND SHOULD
MEANDER IN THIS AREA THROUGH THIS AFTERNOON...PRODUCING ANOTHER 1
TO 3 INCHES OF SNOW ACCUMULATION. SO WILL KEEP WARNING IN EFFECT
TIL 4 PM CST FOR MNZ020. WE ARE EXPECTING THE LAKE EFFECT SNOW TO
BECOME MORE SCATTERED THIS EVENING AS THE WINDS BECOMES LIGHT AND
THEN TURNS OUT OF THE WEST OVERNIGHT. OTHERWISE FCST LOOKS ON
TRACK FOR TODAY.
&&
.PREV DISCUSSION... /ISSUED 1127 AM CST SUN MAR 4 2012/
AVIATION...18Z TAFS.
WEAK INVERTED SFC TROF CONTINUES TO HANG AROUND WESTERN LAKE
SUPERIOR WITH MVFR CIGS AND OCCASIONAL -SHSN WITH VSBYS INTO MVFR
RANGE IN THE VCNTY OF THE -SHSN. KINL AND KBRD WILL BE VFR AS THEY
ARE FAR ENOUGH W OF THE TROF. KBRD MAY BE CLIPPED BY MVFR CIGS FOR
A TIME THIS AFTERNOON AS SHARP VORT MAX DIVES THROUGH EASTERN SD.
THE INVERTED TROF FINALLY DISSOLVES BY 06Z ALLOWING FOR A CLEARING
TREND. BY 15Z MONDAY...A SLY FLOW DEVELOPS IN STRONG WAA. VFR CIGS
WILL SPREAD INTO THE AREA FROM THE W AS A SFC WARM FRONT MOVES
ALONG THE CANADIAN BORDER. ADDED A VCSH AT KINL WHICH WILL BE
CLOSEST TO THE FRONT AND BEST FORCING TO POSSIBLY PRODUCE SOME
PCPN.
PREV DISCUSSION... /ISSUED 542 AM CST SUN MAR 4 2012/
AVIATION...12Z TAFS
AN INVERTED TROUGH AND ONSHORE WINDS WERE COMBINING TO PRODUCE
SNOW OVER THE TWIN PORTS NORTH THROUGH SILVER BAY...WITH LIGHTER
SNOW FALLING IN SPOTS ACROSS THE THE REST OF THE NORTHLAND. THERE
HAS BEEN CLEARING THAT HAS MOVED AS FAR EAST AS K04W NORTH TO JUST
WEST OF KHIB TO KBDE. WE EXPECT MVFR CEILINGS WITH OCCASIONAL LOW
VFR OVER FAR EASTERN MINNESOTA AND MUCH OF NORTHWEST WISCONSIN
TODAY. CLOUDS MAY SCATTER OUT AT KHIB/KINL FOR A TIME...BUT A
CLIPPER MOVING SOUTHWEST OF THE NORTHLAND WILL BRING IN MORE
CLOUDS TODAY. CEILINGS MAY INITIALLY BE LOW VFR...BUT MVFR
CEILINGS WILL THEN DEVELOP. THE HEAVIEST LAKE EFFECT SNOW BAND HAS
BEEN JUST NORTH AND EAST OF KDLH SO FAR THIS MORNING WITH LIFR
CONDITIONS LIKELY IN THE SNOW BAND...BUT THE RUC AND NAM12 SHOW
BACKING LOW LEVEL WINDS AND LOW LEVEL CONVERGENCE INCREASING OVER
KDLH THIS AFTERNOON. SNOW SHOWERS MAY INCREASE IN INTENSITY THIS
AFTERNOON OVER KDLH.
THE INVERTED TROUGH WILL WEAKEN TONIGHT WITH FLOW BECOMING MORE
WEST-NORTHWEST. THIS CHANGE IN LOW LEVEL FLOW WILL ALSO ALLOW THE
LAKE EFFECT SNOW TO END.
PREV DISCUSSION... /ISSUED 301 AM CST SUN MAR 4 2012/
SHORT TERM...
TODAY THROUGH MONDAY AFTERNOON...
LAKE EFFECT SNOW SHOWERS ALONG THE NORTH SHORE TODAY FROM DULUTH
TO SILVER BAY WILL BE THE MAIN FOCUS IN THE SHORT TERM. A LAKE
EFFECT SNOW ADVISORY IS IN EFFECT UNTIL 4 PM THIS AFTERNOON FOR
THIS AREA.
A BROAD UPPER TROUGH IS POSITIONED OVER THE ERN CONUS WITH AN
UPPER RIDGE BUILDING IN ACROSS THE WEST COAST. AT THE SFC AN
INVERTED TROUGH REMAINS DRAPED ACROSS THE GREAT LAKES...EXTENDING
FROM LAKE ONTARIO THROUGH MICHIGAN AND BACK INTO WRN LAKE
SUPERIOR. A SFC HIGH IS SITUATED OVER NRN ONTARIO WITH A SECOND
NARROW SFC HIGH CUTTING THROUGH THE RED RIVER VALLEY AS THE NEXT
SYSTEM PREPARES TO MOVE THROUGH SRN MN FROM THE NRN ROCKIES. THE
EXTENSION OF THIS INVERTED TROUGH INTO THE NORTHLAND ALONG WITH
THE COMBINATION OF A PERSISTENT ELY FLOW FROM THE SFC HIGH TO THE
NORTH AND COLD AIR ALOFT HAS ALLOWED THE LOCALIZED LAKE
EFFECT SNOW SHOWERS TO CONTINUE THROUGH THE LAST 24-36 HOURS.
ATTM...IT APPEARS THIS SET UP WILL PERSIST THROUGH THIS MORNING
AND INTO THE MID AFTERNOON TODAY BEFORE THE WINDS SHIFT TO THE
WEST AND CUT OFF THE LES PROCESSES. LATEST NAM12 AND RUC13 BOTH
INDICATE THE LOW LEVEL E/NE WINDS...STEEP 0-3KM LAPSE
RATES...SATURATED BL AND 1000-900MB CONVERGENT CONDITIONS WILL
PERSIST THROUGH THE REST OF THE MORNING UNTIL AROUND 21/22Z. A
FAIRLY INTENSE LINE OF REGENERATIVE LE SNOW SHOWERS HAVE BEEN
INDICATED ON THE DLH RADAR FOR THE PAST 4-5 HOURS MAINLY
AROUND TWO HARBORS...AND IT APPEARS WILL CONTINUE FOR QUITE SOME
TIME. THERE IS SOME QUESTION AS TO WHETHER THIS BAND COULD VEER TO
THE NORTH TO AROUND SILVER BAY...OR TO THE SOUTH TO DULUTH...OR
EVEN IF ADDITIONAL SNOW BANDS COULD DEVELOP THROUGH THE HEAD OF
THE LAKE. GIVEN THE LATEST RADAR TRENDS AND FAVORABLE CONDITIONS
FOR LES TO PERSIST...WILL ISSUE A LAKE EFFECT SNOW ADVISORY FOR
SOUTHEAST ST. LOUIS COUNTY AND SOUTHERN LAKE COUNTY ALONG THE LAKE
SHORE UNTIL 4 PM. WILL LIKELY SEE 3 TO 5 INCHES IN THIS
AREA...WITH LOCALLY HIGHER AMOUNTS IN LOCATIONS THAT SEE A
PERSISTENT MDT/HVY SNOW BAND THIS MORNING. THE AREA AROUND TWO
HARBORS IS THE MOST LIKELY LOCATION FOR THE HEAVIEST SNOW. EVEN
THOUGH CARLTON COUNTY AND PARTS OF WEST DULUTH/HERMANTOWN ARE IN
THE ADVISORY...A GOOD PORTION OF THIS ZONE WILL ONLY SEE 1-2
INCHES AT MOST. THE MAIN AREA WE ARE CONCENTRATING ON IS FROM THE
NE SECTIONS OF DULUTH NEWD ALONG THE SHORE TO AROUND SLIVER BAY.
COULD SEE A FEW LIGHT SHOW SHOWERS LINGER OVER THE ARROWHEAD AND
NW WI TONIGHT...BUT WITH ONLY LIGHT ADDITIONAL ACCUMULATIONS
EXPECTED. THE SFC RIDGE AXIS SLIDES QUICKLY THROUGH THE REGION
TOMORROW AND ALLOWS CONDITIONS TO DRY OUT...SKIES TO CLEAR OFF
PARTIALLY AND TEMPERATURES TO WARM WELL INTO THE 30S.
THE NEXT WEAK SYSTEM SLIDES ACROSS THE NORTH LATE TOMORROW
AFTERNOON AND BRINGS ANOTHER CHANCE OF SNOW SHOWERS TO THE
BORDERLAND FROM INTL FALLS TO VIRGINIA TO GRAND MARAIS. ONLY LIGHT
ACCUMULATIONS ARE EXPECTED.
LONG TERM...
MONDAY NIGHT THROUGH SATURDAY...
THE MODELS ARE IN BETTER AGREEMENT THROUGH MUCH OF THE PERIOD.
WARM AIR WILL BE IN PLACE EARLY IN THE PERIOD. SOME LIGHT PRECIP
WILL BE POSSIBLE MONDAY NIGHT ACROSS THE FAR NORTH...WHICH WOULD
LIKELY FALL AS A LIGHT MIX. PERSISTENT WAA AND STRENGTHENING
INVERSION COULD LEAD TO BOTH SOME DRIZZLE AND MORE CLOUD COVER
THAN WE CURRENTLY HAVE IN THE GRIDS. AT THIS TIME...WE`LL KEEP
TUESDAY DRY AND CLOUD COVER AS PARTLY CLOUDY. A COLD FRONT WILL
MOVE THE NORTHLAND TUESDAY NIGHT INTO WEDNESDAY...WITH A CHANCE
FOR PRECIP BOTH AHEAD AND BEHIND THE BOUNDARY. WE ADDED A SLIGHT
CHANCE FOR LIGHT RAIN TUESDAY EVENING WITH 35-45KT SOUTHWEST WINDS
AT 850MB FORECAST. RAIN SHOULD BE THE MAIN PRECIP TYPE AHEAD OF
THE FRONT WITH WARM 850MB TEMPS FORECAST...TRANSITIONING TO MAINLY
SNOW WELL BEHIND THE FRONT. PRECIP AMOUNTS SHOULD BE LIGHT.
GFS/ECMWF DIFFER SOME ON THURSDAY WITH HOW FAR SOUTH THEY BRING A
SHORTWAVE TROUGH AND SURFACE LOW PRESSURE. WE WENT CLOSER TO THE
ECMWF AND HAVE A CHANCE FOR LIGHT SNOW. AGAIN WITH THIS
SYSTEM...PRECIP AMOUNTS LOOK LIGHT...WITH THE EXCEPTION OF
THURSDAY NIGHT/FRIDAY ALONG THE SOUTH SHORE WHICH COULD SEE SOME
BETTER SNOW ACCUMULATIONS DUE TO LAKE EFFECT PROCESSES.
NEXT WEEKEND LOOKS DRY WITH A SIGNIFICANT WARM UP FORECAST BY
BOTH THE GFS/ECMWF.
&&
.POINT TEMPS/POPS...
DLH 25 11 33 28 / 60 20 10 10
INL 24 5 35 29 / 20 10 40 20
BRD 28 13 36 30 / 20 10 10 10
HYR 28 8 34 29 / 30 10 10 10
ASX 26 12 35 29 / 40 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...LAKE EFFECT SNOW WARNING UNTIL 4 PM CST THIS AFTERNOON FOR
MNZ020.
WI...NONE.
&&
$$
SHORT TERM...BERDES
AREA FORECAST DISCUSSION
NWS DULUTH MN
1127 AM CST SUN MAR 4 2012
.AVIATION...18Z TAFS.
WEAK INVERTED SFC TROF CONTINUES TO HANG AROUND WESTERN LAKE
SUPERIOR WITH MVFR CIGS AND OCCASIONAL -SHSN WITH VSBYS INTO MVFR
RANGE IN THE VCNTY OF THE -SHSN. KINL AND KBRD WILL BE VFR AS THEY
ARE FAR ENOUGH W OF THE TROF. KBRD MAY BE CLIPPED BY MVFR CIGS FOR
A TIME THIS AFTERNOON AS SHARP VORT MAX DIVES THROUGH EASTERN SD.
THE INVERTED TROF FINALLY DISSOLVES BY 06Z ALLOWING FOR A CLEARING
TREND. BY 15Z MONDAY...A SLY FLOW DEVELOPS IN STRONG WAA. VFR CIGS
WILL SPREAD INTO THE AREA FROM THE W AS A SFC WARM FRONT MOVES
ALONG THE CANADIAN BORDER. ADDED A VCSH AT KINL WHICH WILL BE
CLOSEST TO THE FRONT AND BEST FORCING TO POSSIBLY PRODUCE SOME
PCPN.
&&
.PREV DISCUSSION... /ISSUED 542 AM CST SUN MAR 4 2012/
AVIATION...12Z TAFS
AN INVERTED TROUGH AND ONSHORE WINDS WERE COMBINING TO PRODUCE
SNOW OVER THE TWIN PORTS NORTH THROUGH SILVER BAY...WITH LIGHTER
SNOW FALLING IN SPOTS ACROSS THE THE REST OF THE NORTHLAND. THERE
HAS BEEN CLEARING THAT HAS MOVED AS FAR EAST AS K04W NORTH TO JUST
WEST OF KHIB TO KBDE. WE EXPECT MVFR CEILINGS WITH OCCASIONAL LOW
VFR OVER FAR EASTERN MINNESOTA AND MUCH OF NORTHWEST WISCONSIN
TODAY. CLOUDS MAY SCATTER OUT AT KHIB/KINL FOR A TIME...BUT A
CLIPPER MOVING SOUTHWEST OF THE NORTHLAND WILL BRING IN MORE
CLOUDS TODAY. CEILINGS MAY INITIALLY BE LOW VFR...BUT MVFR
CEILINGS WILL THEN DEVELOP. THE HEAVIEST LAKE EFFECT SNOW BAND HAS
BEEN JUST NORTH AND EAST OF KDLH SO FAR THIS MORNING WITH LIFR
CONDITIONS LIKELY IN THE SNOW BAND...BUT THE RUC AND NAM12 SHOW
BACKING LOW LEVEL WINDS AND LOW LEVEL CONVERGENCE INCREASING OVER
KDLH THIS AFTERNOON. SNOW SHOWERS MAY INCREASE IN INTENSITY THIS
AFTERNOON OVER KDLH.
THE INVERTED TROUGH WILL WEAKEN TONIGHT WITH FLOW BECOMING MORE
WEST-NORTHWEST. THIS CHANGE IN LOW LEVEL FLOW WILL ALSO ALLOW THE
LAKE EFFECT SNOW TO END.
PREV DISCUSSION... /ISSUED 301 AM CST SUN MAR 4 2012/
SHORT TERM...
TODAY THROUGH MONDAY AFTERNOON...
LAKE EFFECT SNOW SHOWERS ALONG THE NORTH SHORE TODAY FROM DULUTH
TO SILVER BAY WILL BE THE MAIN FOCUS IN THE SHORT TERM. A LAKE
EFFECT SNOW ADVISORY IS IN EFFECT UNTIL 4 PM THIS AFTERNOON FOR
THIS AREA.
A BROAD UPPER TROUGH IS POSITIONED OVER THE ERN CONUS WITH AN
UPPER RIDGE BUILDING IN ACROSS THE WEST COAST. AT THE SFC AN
INVERTED TROUGH REMAINS DRAPED ACROSS THE GREAT LAKES...EXTENDING
FROM LAKE ONTARIO THROUGH MICHIGAN AND BACK INTO WRN LAKE
SUPERIOR. A SFC HIGH IS SITUATED OVER NRN ONTARIO WITH A SECOND
NARROW SFC HIGH CUTTING THROUGH THE RED RIVER VALLEY AS THE NEXT
SYSTEM PREPARES TO MOVE THROUGH SRN MN FROM THE NRN ROCKIES. THE
EXTENSION OF THIS INVERTED TROUGH INTO THE NORTHLAND ALONG WITH
THE COMBINATION OF A PERSISTENT ELY FLOW FROM THE SFC HIGH TO THE
NORTH AND COLD AIR ALOFT HAS ALLOWED THE LOCALIZED LAKE
EFFECT SNOW SHOWERS TO CONTINUE THROUGH THE LAST 24-36 HOURS.
ATTM...IT APPEARS THIS SET UP WILL PERSIST THROUGH THIS MORNING
AND INTO THE MID AFTERNOON TODAY BEFORE THE WINDS SHIFT TO THE
WEST AND CUT OFF THE LES PROCESSES. LATEST NAM12 AND RUC13 BOTH
INDICATE THE LOW LEVEL E/NE WINDS...STEEP 0-3KM LAPSE
RATES...SATURATED BL AND 1000-900MB CONVERGENT CONDITIONS WILL
PERSIST THROUGH THE REST OF THE MORNING UNTIL AROUND 21/22Z. A
FAIRLY INTENSE LINE OF REGENERATIVE LE SNOW SHOWERS HAVE BEEN
INDICATED ON THE DLH RADAR FOR THE PAST 4-5 HOURS MAINLY
AROUND TWO HARBORS...AND IT APPEARS WILL CONTINUE FOR QUITE SOME
TIME. THERE IS SOME QUESTION AS TO WHETHER THIS BAND COULD VEER TO
THE NORTH TO AROUND SILVER BAY...OR TO THE SOUTH TO DULUTH...OR
EVEN IF ADDITIONAL SNOW BANDS COULD DEVELOP THROUGH THE HEAD OF
THE LAKE. GIVEN THE LATEST RADAR TRENDS AND FAVORABLE CONDITIONS
FOR LES TO PERSIST...WILL ISSUE A LAKE EFFECT SNOW ADVISORY FOR
SOUTHEAST ST. LOUIS COUNTY AND SOUTHERN LAKE COUNTY ALONG THE LAKE
SHORE UNTIL 4 PM. WILL LIKELY SEE 3 TO 5 INCHES IN THIS
AREA...WITH LOCALLY HIGHER AMOUNTS IN LOCATIONS THAT SEE A
PERSISTENT MDT/HVY SNOW BAND THIS MORNING. THE AREA AROUND TWO
HARBORS IS THE MOST LIKELY LOCATION FOR THE HEAVIEST SNOW. EVEN
THOUGH CARLTON COUNTY AND PARTS OF WEST DULUTH/HERMANTOWN ARE IN
THE ADVISORY...A GOOD PORTION OF THIS ZONE WILL ONLY SEE 1-2
INCHES AT MOST. THE MAIN AREA WE ARE CONCENTRATING ON IS FROM THE
NE SECTIONS OF DULUTH NEWD ALONG THE SHORE TO AROUND SLIVER BAY.
COULD SEE A FEW LIGHT SHOW SHOWERS LINGER OVER THE ARROWHEAD AND
NW WI TONIGHT...BUT WITH ONLY LIGHT ADDITIONAL ACCUMULATIONS
EXPECTED. THE SFC RIDGE AXIS SLIDES QUICKLY THROUGH THE REGION
TOMORROW AND ALLOWS CONDITIONS TO DRY OUT...SKIES TO CLEAR OFF
PARTIALLY AND TEMPERATURES TO WARM WELL INTO THE 30S.
THE NEXT WEAK SYSTEM SLIDES ACROSS THE NORTH LATE TOMORROW
AFTERNOON AND BRINGS ANOTHER CHANCE OF SNOW SHOWERS TO THE
BORDERLAND FROM INTL FALLS TO VIRGINIA TO GRAND MARAIS. ONLY LIGHT
ACCUMULATIONS ARE EXPECTED.
LONG TERM...
MONDAY NIGHT THROUGH SATURDAY...
THE MODELS ARE IN BETTER AGREEMENT THROUGH MUCH OF THE PERIOD.
WARM AIR WILL BE IN PLACE EARLY IN THE PERIOD. SOME LIGHT PRECIP
WILL BE POSSIBLE MONDAY NIGHT ACROSS THE FAR NORTH...WHICH WOULD
LIKELY FALL AS A LIGHT MIX. PERSISTENT WAA AND STRENGTHENING
INVERSION COULD LEAD TO BOTH SOME DRIZZLE AND MORE CLOUD COVER
THAN WE CURRENTLY HAVE IN THE GRIDS. AT THIS TIME...WE`LL KEEP
TUESDAY DRY AND CLOUD COVER AS PARTLY CLOUDY. A COLD FRONT WILL
MOVE THE NORTHLAND TUESDAY NIGHT INTO WEDNESDAY...WITH A CHANCE
FOR PRECIP BOTH AHEAD AND BEHIND THE BOUNDARY. WE ADDED A SLIGHT
CHANCE FOR LIGHT RAIN TUESDAY EVENING WITH 35-45KT SOUTHWEST WINDS
AT 850MB FORECAST. RAIN SHOULD BE THE MAIN PRECIP TYPE AHEAD OF
THE FRONT WITH WARM 850MB TEMPS FORECAST...TRANSITIONING TO MAINLY
SNOW WELL BEHIND THE FRONT. PRECIP AMOUNTS SHOULD BE LIGHT.
GFS/ECMWF DIFFER SOME ON THURSDAY WITH HOW FAR SOUTH THEY BRING A
SHORTWAVE TROUGH AND SURFACE LOW PRESSURE. WE WENT CLOSER TO THE
ECMWF AND HAVE A CHANCE FOR LIGHT SNOW. AGAIN WITH THIS
SYSTEM...PRECIP AMOUNTS LOOK LIGHT...WITH THE EXCEPTION OF
THURSDAY NIGHT/FRIDAY ALONG THE SOUTH SHORE WHICH COULD SEE SOME
BETTER SNOW ACCUMULATIONS DUE TO LAKE EFFECT PROCESSES.
NEXT WEEKEND LOOKS DRY WITH A SIGNIFICANT WARM UP FORECAST BY
BOTH THE GFS/ECMWF.
&&
.POINT TEMPS/POPS...
DLH 25 11 33 28 / 60 20 10 10
INL 24 5 35 29 / 20 10 40 20
BRD 28 13 36 30 / 20 10 10 10
HYR 28 8 34 29 / 30 10 10 10
ASX 26 12 35 29 / 40 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...LAKE EFFECT SNOW ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR
MNZ037.
LAKE EFFECT SNOW WARNING UNTIL 4 PM CST THIS AFTERNOON FOR
MNZ020.
WI...NONE.
&&
$$
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1007 AM MST SUN MAR 4 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY...
A MUCH WARMER AIRMASS ARRIVED FROM THE W YESTERDAY AND OVERNIGHT.
THERE WAS A WEAK COLD FRONT FROM THE NW MOVE ACROSS THE AREA
OVERNIGHT...BUT IMPACT ON TEMPS MINOR. 9 AM TEMPS WERE IN THE
UPPER 20S TO MID 30S THROUGHOUT NE MT. FURTHER WARMING TODAY
THOUGH SOMEWHAT LIMITED AS THE AIRMASS IS ALREADY WELL MIXED OUT
IN NW WINDS IN LOWER LEVELS.
WEAK ECHOES SEEN ON 88D RADAR PRODUCING FLURRIES THIS MORN ALONG
135KT NW JET. CLOUD TOPS UPSTREAM ARE LOW ON SATELLITE CHANNELS
AND MODELS AND HRRR RADAR LOOP INDICATE FURTHER DRYING FOR OUR AREA.
THE JET BECOMING MORE ANTICYCLONIC TOO...SO WILL GO DRY FOR THE
AFTERNOON. THE COLD FRONT EXTENDS BACK UPSTREAM TO A SURFACE WAVE
IN AB. THIS WAVE WILL CAUSE THE COLD FRONT TO REVERSE AND BECOME A
WARM FRONT AS IT MOVES SE...WHICH WILL KEEP GENERALLY MOSTLY
CLOUDY SKIES ACROSS CWA THRU THE AFTERNOON...WITH LESSENING WIND...WHICH
IS ALREADY OCCURRING. UPDATE FOR POPS...TEMPS...WINDS. SIMONSEN
PREVIOUS SHORT TERM...FOR NORTHEAST MONTANA....TODAY THROUGH
TUESDAY...A STRONG UPPER JET ALOFT AND A SURFACE BOUNDARY ARE
WORKING TOGETHER THIS MORNING TO PRODUCE A LARGE AREA OF RAIN AND
SNOW SHOWERS ACROSS NORTHEAST MONTANA. THE UPPER JET AND SURFACE
BOUNDARY LIFT NORTHEAST TODAY INTO TONIGHT BRINGING IN WARM AIR
AND DRY CONDITIONS.
MONDAY AHEAD OF THE NEXT COLD FRONT AND UPPER TROUGH IT WILL GET
VERY WARM ACROSS NORTHEAST MONTANA. COULD SEE SOME 60S IN THE
SOUTHWESTERN ZONES. HOWEVER NOT RECORD HIGH TEMPERATURES... BUT A
NICE REMINDER THAT SPRING IS COMING.
MONDAY NIGHT INTO TUESDAY MORNING THE FRONT WILL CROSS THE
FORECAST AREA WITH RAIN SHOWERS CHANGING OVER TO SNOW SHOWERS
AFTER FRONTAL PASSAGE. THE UPPER SUPPORT LOOKS GOOD WITH THIS
SYSTEM WITH LAPSE RATES AROUND 8C/KM... ALONG WITH 50-100 J/KG OF
CAPE SO CAN NOT RULE OUT A RUMBLE OF THUNDER WITH THE TIMING OF
THIS SYSTEM AT PEAK HEATING TIME. JUST HAVE SOME ISSUES WITH
PUTTING IN THUNDER AT THIS TIME.
MODELS THIS RUN ARE PRETTY CLOSE IN TIMING WITH THE FEATURES AND
PLACEMENT OF THE UPPER LEVEL FEATURES THAT CONFIDENCE IS FAIRLY
HIGH WITH THE FORECAST ELEMENTS FOR THE SHORT TERM. PROTON
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
THE UPPER TROUGH THAT MOVED INTO WESTERN MONTANA TUESDAY AFTERNOON
WILL CONTINUE ACROSS EASTERN MONTANA TUESDAY NIGHT. THE SYSTEM
WILL SPLIT AND SEND MOST OF THE ENERGY SOUTHWARD OVER THE GREAT
BASIN WHICH WILL BECOME A CLOSED LOWS OVER THE FOUR CORNERS BY MID
WEEK. THE WEATHER MODELS ARE IN GOOD AGREEMENT WITH THIS AND THE
PRECIP APPEARS TO GO AROUND US WITH THIS SYSTEM. LEFT POPS ALONE
AS THEY SEEM TO MATCH THE 00Z MODEL OUTPUT FOR THIS SYSTEM. SURFACE
HIGH FROM SASKATCHEWAN WILL SLIDE SOUTH OVER THE MONTANA NORTH
DAKOTA BORDER BRINGING CLEARING SKIES AND 850 MB TEMPS TO AS LOW
AS -14C TUESDAY NIGHT. THIS SHOULD DROP LOWS INTO THE TEENS WITH A
FEW SINGLE DIGITS ACROSS FAR NORTHEASTERN MONTANA.
AN UPPER LEVEL RIDGE WILL TAKE OVER THE WEATHER PATTERN FOR THE
REST OF THE WEEK AND CONTROL THE WEATHER PATTERN ACROSS EASTERN
MONTANA. EXPECT A SLOWER WARMING TREND INT0 THE WEEKEND WHERE HIGHS
MIGHT REACH THE MIDDLE 50S ACCORDING TO THE MODEL BLEND. ONE THING
THAT STOOD OUT IN THE MODELS IS THE POSITIONS OF THE CLOSED LOW
OVER THE FOUR CORNERS REGION WEDNESDAY INTO THURSDAY NIGHT. THE 00Z
GFS/GEM HAS IT MOVING EASTWARD FASTER THEN THE 00Z ECMWF. THE
POSITION OF THIS CLOSED LOW ALONG WITH UPPER TROUGH OVER THE GULF
OF ALASKA ARE THE BIGGEST DIFFERENCES IN THE MODELS. THE UPPER
RIDGE MOVING FROM WESTERN MONTANA TO EASTERN MONTANA FROM THURSDAY
NIGHT INTO SATURDAY MORNING IS PRETTY CONSISTENT ON ALL THREE
MODELS. SUNDAY AND BEYOND MODELS ARE OUT OF PHASE WITH HOW DEEP
THE APPROACHING UPPER TROUGH WILL BECOME OVER THE GULF OF
ALASKA. RSMITH
&&
.AVIATION...
VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS. A FEW SNOW OR
RAIN SHOWERS MAY AFFECT THE TAF SITES THROUGH EARLY THIS AFTERNOON
AND BRIEFLY DROP FLIGHT CONDITIONS TO MVFR LEVELS. RAE
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
344 PM CST SUN MAR 4 2012
.SHORT TERM...THROUGH 00Z TUESDAY. MORNING UPPER AIR ANALYSIS INDICATES
LONG WAVE RIDGING OVER THE WESTERN CONUS AND TROUGHING OVER THE
EAST. MID AND UPPER LEVEL JET ENERGY IS POSITIONED OVER THE
CENTRAL PLAINS AS A RESULT. FLOW REMAINS VERY STRONG THROUGH LOWER
PORTIONS OF THE TROPOSPHERE AS WELL...WITH A ~50KT 700MB JET
STREAK AND A ~40KT 850MB JET STREAK CURRENTLY OVER PORTIONS OF THE
CENTRAL PLAINS. WATER VAPOR IMAGERY INDICATES INCREASING MID LEVEL
MOISTURE ACROSS MUCH OF THE CENTRAL CONUS ALONG THE MID LEVEL JET
AXIS. AT THE SURFACE A WEAK AREA OF LOW PRESSURE IS SITUATED OVER
THE MISSOURI VALLEY...WITH LOW LEVEL FLOW REMAINING FROM THE
NORTHWEST ACROSS MUCH OF OUR AREA AS A RESULT.
PROXIMITY SOUNDINGS FROM LAPS AND RUC ANALYSIS SUGGEST BOUNDARY
LAYER MIXING TO BETWEEN 750MB AND 700MB PERSISTS AT THIS HOUR ACROSS
MUCH OF OUR CWA...A TREND WHICH WILL CONTINUE UNTIL DIABATIC HEATING
IS LOST LATER THIS EVENING. ALSO...AS MENTIONED ABOVE...RUC ANALYSIS
INDICATES A 700MB JET STREAK OF ~50KTS AND AN 850MB JET STREAK OF
~40KTS ALSO PERSISTS OVER THE AREA. SUSTAINED WINDS OF 20KTS TO NEAR
35KTS...WITH GUSTS AROUND 40KTS...CONTINUE ACROSS MUCH OF THE CWA
AS A RESULT. ALTHOUGH WIND ADVISORY WINDS ARE NOT AS PREVALENT
FARTHER SOUTH/SOUTHWEST ACROSS OUR CWA...KMCK CONTINUES TO REPORT
STRONG WINDS...SOME OF WHICH COULD SLIP INTO KHDE AND KPHG TOWARDS
LATE AFTERNOON. GIVEN ALL THIS...WILL CONTINUE THE CURRENT WIND
ADVISORY THROUGH 00Z. THESE WINDS SHOULD SUBSIDE VERY QUICKLY AROUND
SUNSET AS DIABATIC HEATING IS LOST AND THE BOUNDARY LAYER IS
DECOUPLED FROM THE STRONGER WINDS ALOFT.
ALTHOUGH THE MID AND UPPER LEVEL JET AXIS IS OVER US KNOW...IT HAS
BEGUN TO DRIFT EAST...AWAY FROM OUR AREA. MID AND UPPER LEVEL JET
ENERGY SHOULD MOVE COMPLETELY OUT OF OUR AREA TONIGHT...THUS
PRESENTING LITTLE TO NO KINEMATIC FORCING ACROSS OUR AREA THROUGH
THE REMAINDER OF THE SHORT TERM FORECAST PERIOD. DRY CONDITIONS ARE
FORECAST TONIGHT AND TOMORROW AS A RESULT.
FORECAST PROXIMITY SOUNDINGS FROM THE NAM AND OPERATIONAL GFS
SUGGEST BOUNDARY LAYER MIXING TO AROUND 800MB...IF NOT SLIGHTLY
DEEPER...WILL BE REALIZED ACROSS THE CWA MONDAY AFTERNOON. AS THE
MID LEVEL JET AXIS SHIFTS EAST INTO THE MISSISSIPPI VALLEY SO WILL
THE MID LEVEL MOISTURE PLUME...THUS ELIMINATING THE INCREASED RH
VALUES WE HAVE SEEN AT THE TOP OF THE MIXED LAYER BOTH TODAY AND
YESTERDAY. THIS WILL IN TURN PRESENT AN OPPORTUNITY FOR AFTERNOON
SURFACE DEW POINTS TO DROP OFF AS BOUNDARY LAYER MIXING COMMENCES
MONDAY AFTERNOON. THANKFULLY...A STIFF SOUTHERLY LOW LEVEL WIND
FIELD...PERHAPS TURNING A TOUCH SOUTHWESTERLY BY MID TO LATE
AFTERNOON BUT NOT BY MUCH...SHOULD HELP PROMOTE DESCENT LOW LEVEL
MOISTURE INFLUX TO OUR AREA. THIS SHOULD HELP OFFSET AFTERNOON DROPS
IN DEW POINTS. ALL THAT BEING SAID...THE CURRENT FORECAST SHOWS MONDAY
AFTERNOON SURFACE RH VALUES DROPPING TO AROUND 21% FOR A COUPLE
HOURS ACROSS OUR EXTREME SOUTHWEST. THIS LOOKS LIKE A MARGINAL RFW
EVENT FOR EXTREME SOUTHWESTERN PORTIONS OF OUR CWA MONDAY. WILL
HOLD OFF ON ANY FIRE WEATHER HEADLINES FOR MONDAY AND LET THE
EVENING AND OVERNIGHT SHIFTS EVALUATE FURTHER. WILL HOWEVER GO
AHEAD AND MENTION AN ELEVATED FIRE WEATHER THREAT IN THE HWO TO
GET THE WORD OUT.
THE AFOREMENTIONED BOUNDARY LAYER MIXING ON MONDAY...WORKING IN
CONCERT WITH A STRENGTHENING LOW LEVEL PRESSURE GRADIENT DUE TO AN
INTENSIFYING LEE SIDE TROUGH ACROSS THE FRONT RANGE...WILL PRESENT
YET ANOTHER BREEZY DAY ACROSS THE CWA. MAV GUIDANCE SUGGESTS OUR
EXTREME SOUTH WILL BRIEFLY HIT WIND ADVISORY THRESHOLDS BY MID
AFTERNOON...WHILE THE MET GUIDANCE KEEPS OUR ENTIRE CWA UNDER WIND
ADVISORY THRESHOLDS. WILL KEEP ANY MENTION OF WIND ADVISORY WINDS
OUT OF THE FORECAST FOR NOW...BUT MENTION INCREASED WINDS ACROSS OUR
SOUTH IN THE HWO TO GET THE WORD OUT. FUTURE SHIFTS WILL CERTAINLY WANT
TO KEEP A CLOSE EYE ON MONDAY WINDS TO MAKE SURE THEY WILL INDEED
REMAIN BELOW ADVISORY LEVELS.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY. DRY...QUIET WEATHER WILL
BE IN PLACE MONDAY NIGHT IN A FAIRLY ZONAL PATTERN ALOFT...FOLLOWING
PASSAGE OF SURFACE TROUGH. WARM FRONTAL BOUNDARY LIFTS WELL NORTH
INTO THE DAKOTAS ON TUESDAY AND MODELS ARE CONSISTENT THAT
UNSEASONABLY MILD H85 TEMPS OF 14C TO 15C WILL SETTLE ACROSS THE
INTERIOR CONUS. FORECAST SOUNDINGS SUGGEST MIXING WILL REACH H85
AND SUBSEQUENT HIGH TEMPS SHLD EASILY REACH THE 70S. TUESDAY WILL
NOT BE WITHOUT WIND HOWEVER...WITH FORECAST SOUNDINGS SHOWING WINDS
AT THE TOP OF THE MIXED LAYER RANGING FROM AROUND 17KTS IN OUR WEST
TO OVER 30KTS IN THE EAST. SURFACE GRADIENT IS TIGHTEST IN THE EAST
AND CONDITIONS ARE LOOKING BORDERLINE FOR REACHING WIND ADVISORY
CRITERIA ATTM. CURRENTLY HAVE A FIRE WEATHER WATCH FOR OUR WESTERN
CWA FOR TUESDAY...AND WITH FRONT SLOWING DOWN...WINDS LOOK STRONGER
IN OUR WEST COMPARED TO 24HRS AGO. PROGGED RH VALUES DROP BELOW 20
PERCENT ALONG THE WESTERN PERIPHERY OF OUR CWA...AND WILL LEAVE
CURRENT WATCH HEADLINE AS IS. IF FRONT CONTINUES TO SLOW...HIGHER
DPS MAY MATERIALIZE AS WELL AS HIGHER RH/S. WILL CONTINUE TO
MONITOR.
UPPER TROUGH MOVES INTO THE ROCKIES TUESDAY NIGHT WITH THE SOUTHERN
STREAM CLOSING/CUTTING OFF ON WEDNESDAY...WHILE THE NORTHERN STREAM
TRANSLATES ACROSS THE DAKOTAS/UPPER MIDWEST. THE ASSOCIATED COLD
FRONT WITH NORTHERN SYSTEM GRADUALLY PUSHES SOUTH INTO OUR CWA
OVERNIGHT INTO WEDNESDAY MORNING. THE GFS IS FASTER WITH FRONT THAN
THE NAM AND HAVE TRENDED TOWARD THE SLOWER SOLUTION. FRONTOGENETIC
FORCING INCREASES ALONG BOUNDARY...MAINLY IN THE AFTN...AND WITH
SLOWER TIMING/INCREASING FORCING HAVE EXPANDED POPS TO OUR ENTIRE
CWA. INSTABILITY PROGS SHOW SOME MUCAPE WITH NAM INDICATING VALUES
GENERALLY 25J/KG WITH GFS AS HIGH AS 200 J/K IN OUR FAR SOUTHEAST.
WILL GO WITH CONVECTIVE RAIN SHOWER WORDING FOR NOW AND MONITOR
INSTABILITY TRENDS BEFORE INSERTING THUNDER JUST YET. COLD AIR
ADVECTS SOUTH BEHIND FRONT WITH NW WINDS INCREASING FOR A TIME ON
WED. PCPN CHCS CONTINUES WED NIGHT AND INTO THURSDAY BUT SHIFT
SOUTH WITH TIME ALONG SOUTHWARD ADVANCING BAROCLINIC ZONE. AS TEMPS
DIURNALLY COOL...A MIX OF R/S IS POSSIBLE.
FROM THE LATTER PART OF THE WEEK AND INTO THE WEEKEND MODELS DIVERGE
IN HANDLING OF THE SOUTHWEST CONUS CUTOFF UPPER LOW PRESSURE
SYSTEM. CONFIDENCE REMAINS LOW DURING THIS TIME FRAME GIVEN THE
VARYING SOLUTIONS.
&&
.PREV DISCUSSION... /ISSUED 1134 AM CST SUN MAR 4 2012/
AVIATION...18Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE
NEXT 24 HOURS. MUCH LIKE YESTERDAY...CU DEVELOPMENT NEAR 4000FT
AGL WILL LIKELY BE OBSERVED THROUGH THIS AFTERNOON...WITH CLEARING
SKIES BY 00Z. SURFACE WINDS WILL REMAIN STRONG THROUGH THIS
AFTERNOON...SUSTAINED FROM THE NORTHWEST AT AROUND 30KTS...GUSTING
TO AROUND 42KTS. SURFACE WINDS WILL DIMINISH BY 00Z...BECOMING
LIGHT AND VARIABLE BY 04Z. SURFACE WIND WILL THEN INTENSIFY FROM
THE SOUTH DURING THE DAY MONDAY. VISIBILITY RESTRICTIONS ARE NOT
ANTICIPATED THROUGH THE NEXT 24 HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ039>041-046>049-
060>064-072>077-082>087.
FIRE WEATHER WATCH TUESDAY AFTERNOON FOR NEZ060-072-073-082-083.
KS...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ005>007-017>019.
FIRE WEATHER WATCH TUESDAY AFTERNOON FOR KSZ005-017.
&&
$$
SHORT TERM/AVIATION...BRYANT
LONG TERM...CF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1153 AM CST SUN MAR 4 2012
.AVIATION...
MAINLY VFR CONDITIONS THE NEXT 24 HOURS. WEAK DISTURBANCE MOVING
SOUTHEAST ACROSS THE CENTRAL PART OF THE STATE TODAY. LOCALLY A
BRIEF SPRINKLE IS POSSIBLE THIS AFTERNOON...ALONG A SWATH FROM
KIEN...THRU KTIF...TO KBBW. CIGS MAY BRIEFLY DROP TO HIGH
MVFR...AROUND BKN025...WITHIN THE SPRINKLES. WAVE EXITS THIS
AFTERNOON WITH DECREASING CLOUDS OVERNIGHT...BECOME CLEAR BY
MORNING. NORTHWEST WINDS WILL BE GUSTY THROUGH EARLY
EVENING...25 KTS TO 35 KTS WITH GUSTS TO 45 KTS. WINDS DIMINISH
QUICKLY THIS EVENING WITH THE LOSS OF HEATING...BECOMING LIGHT
OVERNIGHT. SOUTH WINDS AROUND 10KTS DEVELOP IN THE MORNING.
&&
.PREV DISCUSSION.../ISSUED 349 AM CST SUN MAR 4 2012/
DISCUSSION...
FORECAST CHALLENGE OVER THE NEXT 48 HOURS DEALS WITH ADVISORY
CRITERIA WIND SPEEDS THIS AFTERNOON...THEN THE FOCUS SHIFTS TO THE
EXPECTED WARM UP FOR THE BEGINNING OF THE WORK WEEK AND ASSOCIATED
FIRE RISKS.
INHERITED WIND ADVISORY LOOKS TO BE IN GOOD SHAPE...WITH ONLY A FEW
MINOR MODIFICATIONS NEEDED AT THIS POINT IN TIME. WILL GO AHEAD AND
BEGIN THE WIND ADVISORY FOR OUR WESTERN COUNTIES WITH THIS FORECAST
ISSUANCE...AS CRITERIA LEVEL WIND SPEEDS HAVE ALREADY BEEN REPORTED
ACROSS THE WESTERN PANHANDLE EARLY THIS MORNING. WILL ALSO INCLUDE
WESTERN CHERRY AND SHERIDAN COUNTY IN THE ADVISORY AS RECENT HRRR
MODEL OUTPUT SUGGESTS THE POTENTIAL THERE FOR ADVISORY LEVEL WIND
GUSTS. OTHERWISE MODELS CONTINUE TO INDICATE STRONG UNIDIRECTIONAL
FLOW WITH DEEP MIXING THROUGH EARLY-TO-MID AFTERNOON TODAY. WITH
MIXING POTENTIAL AOA 800MB...MOMENTUM TRANSFER OF UP TO 60 KTS IS
POSSIBLE...WHICH WOULD LEAD TO SURFACE WIND GUSTS OF GREATER THAN 45
MPH EARLY THIS AFTERNOON ACROSS MUCH OF THE CWA. BY MID AFTERNOON
THE STRONGEST HEIGHT RISES AND MOMENTUM ALOFT WILL BE NORTH AND EAST
OF FORECAST AREA. THUS EXPECT WIND SPEEDS TO SUBSIDE RATHER QUICKLY
LATER THIS AFTERNOON...SUCH THAT THE ONGOING WIND ADVISORY MAY BE
CANCELED A FEW HOURS EARLY. BUT FOR NOW...WILL CONTINUE THE ONGOING
ADVISORY UNTIL 00Z TONIGHT.
NOT SURE WHAT TO MAKE OF THE CLIPPER TYPE SYSTEM CURRENTLY BRUSHING
OUR NORTHERN AND EASTERN ZONES. -SN HAS BEEN REPORTED AT BOTH KVTN
AND KANW EARLY THIS MORNING...HOWEVER SATURATION ELSEWHERE HAS BEEN
SLOW TO COMMENCE. THE HRRR CONTINUES TO PAINT LIGHT QPF ACROSS OUR
NORTHERN AND WESTERN ZONES THROUGH MID MORNING...NAM IS A BIT MORE
OPTIMISTIC AND DRIER. THE EURO AND TO SOME EXTENT THE GFS SEEM TO
WANT TO GENERATE LIGHT QPF ACROSS OUR WESTERN ZONES LATE THIS
MORNING. WITH THE STEEP LAPSE RATES...WEAK INSTABILITY AND FAVORABLE
UPPER LEVEL DYNAMICS IN PLACE...CANNOT ARGUE AGAINST THE POTENTIAL
OF A -SNSH OR -RASH THROUGH MID MORNING. HOWEVER SOUNDINGS INDICATE
MINIMAL LOW LEVEL MOISTURE AND THE FACT THAT CURRENT RADAR
OBSERVATIONS SUGGEST OTHERWISE...WILL LEAN TOWARD THE THE DRIER
SOLUTIONS...MAINLY THE NAM AND END THE MENTION OF PRECIPITATION
SHORTLY AFTER 15Z THIS MORNING. REVISIONS MAY BE NEEDED.
THE THREAT OF HEIGHTENED FIRE DANGER IS STILL A POSSIBILITY TODAY
ACROSS FAR SOUTHWESTERN PORTIONS OF THE CWA...HOWEVER RELATIVE
HUMIDITY VALUES ARE LOOKING SLIGHTLY BETTER THAN COMPARED WITH
PREVIOUS MODEL RUNS. LOW TO MID LEVEL MOISTURE HAS INCREASED
SLIGHTLY...AND EVEN WITH THE WARMER EXPECTED TEMPERATURES THIS
AFTERNOON...STILL LOOKING FOR MINIMUM RELATIVE HUMIDITY VALUES SOME
10 PERCENT OR GREATER ABOVE RED FLAG CRITERIA. AS OF NOW...FIRE
ZONES 210...219...AND FAR SOUTHWESTERN PORTIONS OF 204 HAVE THE
HIGHEST POTENTIAL OF EXTREME FIRE BEHAVIOR...BUT AGAIN NOT ENOUGH TO
WARRANT ANY FIRE HEADLINES. MONDAY AND ESPECIALLY TUESDAY MAY BE A
DIFFERENT STORY HOWEVER.
FOR THE START OF THE WORK WEEK...A FLAT UPPER LEVEL RIDGE WILL BUILD
ACROSS THE NORTHERN AND CENTRAL PLAINS LATE SUNDAY INTO MONDAY AND
USHER IN STRONG WARM AIR ADVECTION. MODEL GUIDANCE HINTS AT H925
TEMPERATURES ACROSS SOUTHWEST NEBRASKA AOA 15C BY MONDAY AFTERNOON.
FIRE CONCERNS MAY BE POSSIBLE ONCE AGAIN AS RELATIVE HUMIDITY VALUES
APPROACH CRITICAL LEVELS. GENERALLY TRENDED TOWARD THE DRIER ECMWF
GUIDANCE AS THE MODEL HAS PERFORMED REASONABLY WELL THE PAST COUPLE
DAYS WITH THE HANDLING OF THE RELATIVE HUMIDITY FIELDS. NOW ON
MONDAY AFTERNOON SOUTHERLY RETURN FLOW WILL STRENGTHEN AHEAD OF A
DEEPENING HIGH PLAINS SURFACE TROUGH. GENERALLY EMPLOYED THE USE OF
A GUIDANCE BLEND FOR WIND SPEEDS. THIS BLEND WOULD SUGGEST WIND
GUSTS OF LESS THAN 25 MPH /BELOW RED FLAG CRITERIA/.
H85 THERMAL RIDGE SHOULD BE MAXIMIZED ACROSS NORTH CENTRAL NEBRASKA
ON TUESDAY...WITH H85 TEMPERATURES WELL ABOVE 15C ACROSS MUCH OF THE
FORECAST AREA. THIS SHOULD TRANSLATE TO MAXIMUM HIGHS INTO THE MID
TO UPPER 60S ACROSS THE ENTIRE FORECAST AREA...WITH POSSIBLY LOW TO
MID 70S OVER THE HEAT PRONE AREAS OF THE CWA. AGAIN SOUTHERLY
RETURN FLOW LOOKS TO BECOME ESTABLISHED AS LOW PRESSURE DEEPENS IN
RESPONSE TO A DIGGING GREAT BASIN TROUGH. WITH EXPECTED HIGH
TEMPERATURES WELL ABOVE 70 DEGREES FAHRENHEIT ACROSS SOUTHWEST
NEBRASKA...FIRE ZONES 204...210...219 AND POSSIBLY SOUTHERN PORTIONS
OF 206 MAY EXPERIENCE RED FLAG CONDITIONS AS RH VALUES WILL FALL
BELOW 15 PERCENT AND WIND GUSTS WILL FLIRT WITH 25 MPH. A FIRE
WEATHER WATCH AND RED FLAG WARNINGS MAY BE NEEDED FOR TUESDAY.
CHANGES ARE IN STORE THEREAFTER AS A WEST COAST UPPER TROUGH
ADVANCES ON THE NORTHERN AND CENTRAL PLAINS. THE LONG RANGE
SOLUTIONS ALL AGREE THAT A STRONG COLD FRONT WILL ACCOMPANY THE
TROUGH AND BRING AN END TO THE PLEASANT WEATHER CONDITIONS. BY
MIDDAY WEDNESDAY...H85 TEMPERATURES APPEAR TO RUN SOME 15 TO 20C
COOLER THAN THAT TO BE OBSERVED ON TUESDAY. PRECIPITATION CHANCES
ARE BECOMING LESS CERTAIN MID WEEK AS THE TROUGH CONTINUES TO TREND
SOUTH. THE CONSENSUS AND ENSEMBLES CONTINUE TO SUPPORT A SPLIT
PATTERN WHICH WOULD FAVOR A DRY FORECAST FOR MUCH OF THE CWA AS THE
SYSTEM MEANDERS ACROSS THE SOUTHWEST. THE EXTENDED PROCEDURE
GENERALLY CUT BACK POPS ON WEDNESDAY...WHICH LOOKS PLAUSIBLE AT THIS
POINT IN TIME...THUS NO MAJOR CHANGES WERE MADE. OTHERWISE WITH A
SPLIT FLOW REGIME THAT TRANSITIONS TO GENERAL RIDGING ALOFT BY WEEKS
END...A DRY FORECAST WITH NEAR TO SLIGHTLY ABOVE AVERAGE
TEMPERATURES APPEAR REASONABLE AT THIS POINT IN TIME FOR THE
EXTENDED.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 6 PM CST
/5 PM MST/ THIS EVENING FOR
NEZ004>010-022>029-035>038-056>059-069>071-094.
&&
$$
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1250 PM EST SUN MAR 4 2012
.SYNOPSIS...
A SECONDARY COLD FRONT WILL DROP SOUTH ACROSS THE REGION TODAY WITH
SCATTERED SNOW SHOWERS AND LAKE EFFECT SNOW EAST AND SOUTHEAST OF
THE LAKES AS TEMPERATURES DROP TO BELOW AVERAGE. SNOW SHOWERS WILL
GRADUALLY DIMINISH THIS EVENING WITH LAKE EFFECT SNOW LINGERING
SOUTHEAST OF THE LAKES INTO MONDAY MORNING. HIGH PRESSURE WILL
THEN BUILD INTO THE REGION MONDAY NIGHT FOLLOWED BY A RETURN TO
MUCH ABOVE AVERAGE TEMPERATURES BY THE MIDDLE OF THE WEEK. THE
NEXT CHANCE OF RAIN WILL ARRIVE THURSDAY WITH THE APPROACH OF A
COLD FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH 1120 AM...RADAR SHOWS SNOW SHOWERS SOUTH OF LAKE
ONTARIO...CONTINUING TO PUSH SOUTHWARD. VISIBLE SATELLITE SHOWS A
MOISTURE TIE IN BACK TO LAKE HURON...WITH MOISTURE BEING FUNNELED
ALONG THE FRONTAL BOUNDARY. BECAUSE IT IS THE FRONT PROVIDING THE
FOCUS...FEEL THE HRRR AND OTHER HIGHER RESOLUTION MODELS SUCH AS
THE NAM/RGEM SHOULD BE ABLE TO HANDLE THE PROGRESSION OF THIS
BAND. ALL THESE MODELS DROP THIS FRONT (AND ASSOCIATED QPF)
SOUTHWARD TODAY. EXPECT THIS BAND TO WEAKEN A BIT AS IT DROPS
SOUTHWARD ACROSS BUFFALO METRO...BUT STILL SHOULD BRING SOME SNOW
SHOWERS TO THE CITY.
THE BIGGER CONCERN WITH THIS...IS THAT ONCE EXTRA MOISTURE REACHES
THE TYPICALLY FAVORABLE SNOW BELTS OFF LAKE ERIE...THAT SNOW RATES
WILL BE ENHANCED THERE. AS MOISTURE WITH THE FRONT REACHES THESE
LOCATIONS THIS AFTERNOON...EXPECT SNOWFALL RATES TO INCREASE...WITH
A POTENTIAL FOR A FAIRLY QUICK 3 TO 5 INCHES OF SNOW TO FALL THIS
AFTERNOON INTO THE EARLY EVENING HOURS. EXPECT STORM TOTALS TO
PUSH 8 INCHES IN THE MOST FAVORABLE LOCATIONS. NOT ALL LOCATIONS
WILL SEE THIS MUCH SNOW...WITH THE GREATEST AMOUNTS LIKELY TO BE
ACROSS FAR SOUTHERN ERIE...SOUTHERN WYOMING...AND NORTHERN
PORTIONS OF CATTARAUGUS COUNTY. OUTSIDE OF THESE LOCATIONS...EXPECT
LESSER AMOUNTS.
STEADY SNOW SHOWERS HAVE EXITED EAST OF LAKE ONTARIO...WITH MORE
GENERIC SCATTERED SNOW SHOWERS IN THE REGION. EXPECT THIS TO
CONTINUE...BUT WITH ONLY LIGHT ADDITIONAL ACCUMULATIONS THROUGH
MOST OF THE AFTERNOON HOURS. THE ONE THING TO WATCH HERE IS FOR A
LAKE EFFECT BAND TO RE-DEVELOP IN THE NW FLOW...AND TO SET UP
ACROSS WAYNE/N CAYUGA COUNTIES LATE AFTERNOON.
OFF LAKE ERIE TONIGHT...NORTHWEST FLOW WILL MAINTAIN A FEW SNOW
SHOWERS ACROSS THE CHAUTAUQUA RIDGE. THERE MAY BE A BRIEF WINDOW
THIS EVENING WHERE SOME UPSTREAM CONNECTION TRIES TO DEVELOP FROM
LAKE HURON...BUT THIS WILL BE SHORT LIVED AS HIGH PRESSURE
BUILDING OVER THE CENTRAL LAKES QUICKLY SHUTS OFF ANY UPSTREAM
LAKE EFFECT. EXPECT ADDITIONAL AMOUNTS OF 1-3 INCHES IN PERSISTENT
BANDS CENTERED ON SKI COUNTRY.
OFF LAKE ONTARIO TONIGHT...LAKE EFFECT WILL INITIALLY BE VERY
DISORGANIZED IN NORTHWEST FLOW DUE TO THE LINGERING EFFECTS OF
DAYTIME HEATING. BY MID TO LATE EVENING EXPECT A BROKEN BAND TO
CONCENTRATE TO THE SOUTHEAST OF THE LAKE ACROSS WAYNE...N CAYUGA
AND FAR SOUTHERN OSWEGO COUNTIES. SOME OF THIS MAY CLIP THE
NORTHERN AND EASTERN SUBURBS OF ROCHESTER AS WELL. MAY SEE ANOTHER
2-3 INCHES LOCALLY FROM THIS OVERNIGHT.
OUTSIDE OF LAKE EFFECT AREAS...SCATTERED SNOW SHOWERS MAY PRODUCE
ANOTHER DUSTING OF ACCUMULATION THIS EVENING BEFORE ENDING
OVERNIGHT. SNOW SHOWERS MAY LINGER THROUGH THE NIGHT ACROSS THE
HIGHER TERRAIN EAST OF LAKE ONTARIO AS A POCKET OF DEEPER MOISTURE
LINGERS BEHIND THE DEPARTING LOW. MODIFIED ARCTIC AIR WILL SEND
TEMPS BELOW AVERAGE TONIGHT...ALTHOUGH MOS TEMPS LOOK A LITTLE TOO
COLD GIVEN EXTENSIVE LAKE EFFECT CLOUDS. EXPECT LOWS GENERALLY IN
THE MID TEENS...WITH SINGLE DIGITS EAST OF LAKE ONTARIO.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
ON MONDAY...THE LAKE SNOWS EAST-SOUTHEAST OF THE LAKES WILL
GRADUALLY DIMINISH DUE TO BOTH DIURNAL INFLUENCES AND RIDGING
BUILDING EAST FROM THE CENTRAL GREAT LAKES...WHICH WILL PROVIDE MUCH
DRIER AIR AND INCREASING AMOUNTS OF SUBSIDENCE. EXPECT ONLY A FEW
LEFTOVER LIGHT SNOW SHOWERS AND/OR FLURRIES TO BE LEFTOVER BY MONDAY
EVENING...WITH THIS ACTIVITY THEN FALLING APART COMPLETELY DURING
MONDAY NIGHT AS THE AXIS OF THE LOW LEVEL RIDGE MOVES OVERHEAD.
ELSEWHERE...CONDITIONS WILL LARGELY BE JUST DRY AND COLD...WITH WELL
BELOW NORMAL TEMPERATURES CONTINUING GIVEN THE RATHER CHILLY AIRMASS
THAT WILL BE IN PLACE AT THE LOW LEVELS. EXPECT HIGHS TO BE ONLY IN
THE LOWER TO MID 20S ON MONDAY...WITH WIDESPREAD LOWS BETWEEN 10 AND
15 THEN FOLLOWING FOR MONDAY NIGHT AS THE RIDGE AXIS CRESTS OVERHEAD
AND PROVIDES GOOD CONDITIONS FOR RADIATIONAL COOLING. THE NORTH
COUNTRY WILL BE EVEN COLDER...WITH LOWS FALLING TO AROUND ZERO OR
PERHAPS EVEN SLIGHTLY BELOW ACROSS MOST OF JEFFERSON AND LEWIS
COUNTIES.
AFTER THAT...THE SURFACE RIDGE WILL SLIDE EAST TO THE NEW ENGLAND
COAST AND THEN OFFSHORE TUESDAY AND WEDNESDAY...WHILE BROAD UPPER
RIDGING BUILDS EAST ACROSS THE GREAT LAKES AND NORTHEAST. ALL OF
THIS WILL RESULT IN A DEEPENING SOUTHWESTERLY FLOW OF PROGRESSIVELY
MILDER AIR OVERSPREADING THE AREA DURING TUESDAY...THEN CONTINUING
RIGHT THROUGH WEDNESDAY. WHILE THIS WARM ADVECTION PATTERN WILL
RESULT IN SOME MID AND UPPER LEVEL CLOUDS PASSING ACROSS THE AREA
FROM TIME TO TIME...BOTH DAYS STILL LOOK TO REMAIN DRY WITH THE BEST
LIFT AND MOISTURE REMAINING WELL TO OUR NORTH AND WEST IN
ASSOCIATION WITH A SURFACE WARM FRONT LIFTING ACROSS THE
WESTERN/CENTRAL LAKES AND INTO ONTARIO PROVINCE.
UNDER THIS WARM AIR ADVECTION REGIME...925 MB TEMPS WILL STEADILY
CLIMB THROUGH MIDWEEK...EVENTUALLY REACHING THE +4C T0 +9C RANGE BY
WEDNESDAY AFTERNOON. COUPLED WITH A GOOD SOUTHWESTERLY LOW LEVEL
FLOW AND AT LEAST SOME PARTIAL SUNSHINE...THIS WILL ALLOW FOR
DAYTIME HIGH TEMPERATURES TO REBOUND BACK TO MORE NORMAL LEVELS IN
THE MID 30S TO LOWER 40S ON TUESDAY...BEFORE REALLY SOARING INTO THE
MID AND UPPER 50S ACROSS MUCH OF THE AREA ON WEDNESDAY. IN FACT...
THE NORMALLY WARM SPOTS OF THE GENESEE VALLEY/FINGER LAKES MAY EVEN
REACH OR BREAK 60F ON WEDNESDAY.
THE MILD WEATHER WILL THEN CONTINUE THROUGH WEDNESDAY NIGHT AS THE
AFOREMENTIONED SOUTHWESTERLY FLOW REMAINS ANCHORED ACROSS OUR
AREA...IN ADVANCE OF A COLD FRONT SLOWLY APPROACHING FROM THE
CENTRAL GREAT LAKES. WHILE THIS FEATURE WILL BRING A NORTHWEST TO
SOUTHEAST INCREASE IN CLOUD COVER AS IT PUSHES INTO SOUTHERN ONTARIO
LATER IN THE NIGHT...BOTH THE 00Z GFS/ECMWF NOW SUGGEST THAT IT WILL
REMAIN JUST FAR ENOUGH TO OUR NORTH FOR OUR AREA TO REMAIN LARGELY
DRY THROUGH THE NIGHT...HENCE WILL KEEP POPS AT THE SLIGHT CHANCE OR
LOWER FOR WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
WITH THE 00Z GFS/GEM/ECMWF NOW IN MUCH BETTER AGREEMENT THAT THE
AFOREMENTIONED COLD FRONT WILL SLOWLY OOZE ACROSS OUR AREA THURSDAY
AND THURSDAY NIGHT AS IT BECOMES ORIENTED INCREASINGLY PARALLEL TO
THE LARGE-SCALE UPPER LEVEL FLOW...WILL FOCUS CHANCE POPS FOR THE
FRONTAL PASSAGE ON THESE TWO PERIODS...ALONG WITH SOMEWHAT COOLER
BUT STILL ABOVE NORMAL TEMPS ON THURSDAY GIVEN THE INCREASED AMOUNT
OF CLOUD COVER AND PRECIP.
AFTER THAT...THE VARIOUS GUIDANCE PACKAGES DIVERGE AGAIN SOMEWHAT
WITH RESPECT TO HOW QUICKLY THE FRONT DEPARTS OUR AREA TO THE
SOUTHEAST...AS WELL AS IN HOW FAST SIGNIFICANTLY COLDER/DRIER AIR
SUBSEQUENTLY OVERSPREADS OUR AREA FROM THE NORTHWEST FOLLOWING THE
FRONTAL PASSAGE. ALL OF THIS APPEARS TO ULTIMATELY BE TIED TO THE
STRENGTH AND DEPTH OF THE UPPER TROUGH PASSING ACROSS ONTARIO AND
QUEBEC LATE IN THE WEEK...WITH A FASTER/FLATTER TROUGH ALLOWING FOR
A FASTER PROGRESSION ALA THE GFS...AND A SLOWER/SLIGHTLY MORE
AMPLIFIED TROUGH RESULTING IN A SLOWER EVOLUTION MORE ALONG THE
LINES OF THE ECMWF/GEM. AT THIS DISTANT JUNCTURE...WILL JUST OPT TO
KEEP THINGS SIMPLE AND PORTRAY A GENERAL NORTHWEST-SOUTHEAST
DECREASE IN CHANCE POPS ON FRIDAY FOLLOWING THE FRONTAL PASSAGE...
THEN A RETURN TO SEASONABLY COLDER AND DRY CONDITIONS FOR SATURDAY
WITH THE COLDER AIRMASS PRESENTLY APPEARING TO BE TOO DRY TO SUPPORT
MUCH LAKE EFFECT.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AN UPPER LEVEL TROF PASSING TO THE NORTH AND A FRONTAL BOUNDARY
DROPPING ACROSS THE REGION FROM NORTH TO SOUTH IS HELPING ENHANCE
LAKE EFFECT SNOW SHOWER ACTIVITY. FOR BUF/IAG/ROC...EXPECT THIS
SHOULD BE WINDING DOWN WITH THE FRONT TO THE SOUTH. THAT SAID...A
STRAY -SHSN CAN/T BE RULED OUT. EXPECT MOISTURE ALONG THE FRONTAL
BOUNDARY TO MOVE INTO JHW LATER THIS AFTERNOON...WITH A PERIOD OF
IFR OR LOWER CONDITIONS LIKELY.
THE FRONT WILL CONTINUE TO PUSH TO THE SOUTH...AND THE UPPER LEVEL
LOW WILL EXIT TO THE EAST TONIGHT. THIS SHOULD CAUSE LAKE EFFECT
ACTIVITY TO DIMINISH...BUT NOT END. MOST PERSISTENT SNOWS SHOULD
BE SE OF LAKE ONTARIO...AWAY FROM THE TAF LOCATIONS...BUT MAY HAVE
PERIODS OF MVFR OR LOWER CONDITIONS AT ROC/JHW OVERNIGHT. EXPECT
MAINLY VFR CONDITIONS ON MONDAY...OUTSIDE OF A FEW STRAY -SHSN SE OF
THE LAKES.
OUTLOOK...
MONDAY NIGHT THROUGH WEDNESDAY...VFR.
THURSDAY...MVFR/VFR. A CHANCE OF SHOWERS.
FRIDAY...MAINLY VFR.
&&
.MARINE...
WINDS HAVE DIMINISHED TO BELOW GALE EARLY THIS MORNING AS THE STRONG
LOW PRESSURE SYSTEM CONTINUES TO PULL AWAY INTO ATLANTIC CANADA. A
SECONDARY COLD FRONT WILL DROP SOUTH ACROSS THE LOWER LAKES TODAY
WITH MODERATE WESTERLIES BECOMING NORTHWEST. THIS WILL MAINTAIN
SMALL CRAFT ADVISORY CONDITIONS THROUGH THIS EVENING ON BOTH LAKES
ERIE AND ONTARIO. WAVES WILL BEGIN TO COME DOWN LATER THIS EVENING
IN MOST LOCATIONS...EXCEPT AT THE SOUTHEAST CORNER OF LAKE ONTARIO
FROM ABOUT ROCHESTER TO MEXICO BAY WHERE FAVORABLE FETCH WILL
MAINTAIN SMALL CRAFT ADVISORY CONDITIONS THROUGH MONDAY IN NORTHWEST
FLOW. HIGH PRESSURE WILL BUILD OVER THE LOWER LAKES MONDAY NIGHT
WITH WINDS BECOMING LIGHT.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ012-020-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 10 PM EST MONDAY FOR
LOZ043-044.
SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LOZ042-045.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1129 AM EST SUN MAR 4 2012
.SYNOPSIS...
A SECONDARY COLD FRONT WILL DROP SOUTH ACROSS THE REGION TODAY WITH
SCATTERED SNOW SHOWERS AND LAKE EFFECT SNOW EAST AND SOUTHEAST OF
THE LAKES AS TEMPERATURES DROP TO BELOW AVERAGE. SNOW SHOWERS WILL
GRADUALLY DIMINISH THIS EVENING WITH LAKE EFFECT SNOW LINGERING
SOUTHEAST OF THE LAKES INTO MONDAY MORNING. HIGH PRESSURE WILL
THEN BUILD INTO THE REGION MONDAY NIGHT FOLLOWED BY A RETURN TO
MUCH ABOVE AVERAGE TEMPERATURES BY THE MIDDLE OF THE WEEK. THE
NEXT CHANCE OF RAIN WILL ARRIVE THURSDAY WITH THE APPROACH OF A
COLD FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH 1120 AM...RADAR SHOWS SNOW SHOWERS SOUTH OF LAKE
ONTARIO...CONTINUING TO PUSH SOUTHWARD. VISIBLE SATELLITE SHOWS A
MOISTURE TIE IN BACK TO LAKE HURON...WITH MOISTURE BEING FUNNELED
ALONG THE FRONTAL BOUNDARY. BECAUSE IT IS THE FRONT PROVIDING THE
FOCUS...FEEL THE HRRR AND OTHER HIGHER RESOLUTION MODELS SUCH AS
THE NAM/RGEM SHOULD BE ABLE TO HANDLE THE PROGRESSION OF THIS
BAND. ALL THESE MODELS DROP THIS FRONT (AND ASSOCIATED QPF)
SOUTHWARD TODAY. EXPECT THIS BAND TO WEAKEN A BIT AS IT DROPS
SOUTHWARD ACROSS BUFFALO METRO...BUT STILL SHOULD BRING SOME SNOW
SHOWERS TO THE CITY.
THE BIGGER CONCERN WITH THIS...IS THAT ONCE EXTRA MOISTURE REACHES
THE TYPICALLY FAVORABLE SNOW BELTS OFF LAKE ERIE...THAT SNOW RATES
WILL BE ENHANCED THERE. AS MOISTURE WITH THE FRONT REACHES THESE
LOCATIONS THIS AFTERNOON...EXPECT SNOWFALL RATES TO INCREASE...WITH
A POTENTIAL FOR A FAIRLY QUICK 3 TO 5 INCHES OF SNOW TO FALL THIS
AFTERNOON INTO THE EARLY EVENING HOURS. EXPECT STORM TOTALS TO
PUSH 8 INCHES IN THE MOST FAVORABLE LOCATIONS. NOT ALL LOCATIONS
WILL SEE THIS MUCH SNOW...WITH THE GREATEST AMOUNTS LIKELY TO BE
ACROSS FAR SOUTHERN ERIE...SOUTHERN WYOMING...AND NORTHERN
PORTIONS OF CATTARAUGUS COUNTY. OUTSIDE OF THESE LOCATIONS...EXPECT
LESSER AMOUNTS.
STEADY SNOW SHOWERS HAVE EXITED EAST OF LAKE ONTARIO...WITH MORE
GENERIC SCATTERED SNOW SHOWERS IN THE REGION. EXPECT THIS TO
CONTINUE...BUT WITH ONLY LIGHT ADDITIONAL ACCUMULATIONS THROUGH
MOST OF THE AFTERNOON HOURS. THE ONE THING TO WATCH HERE IS FOR A
LAKE EFFECT BAND TO RE-DEVELOP IN THE NW FLOW...AND TO SET UP
ACROSS WAYNE/N CAYUGA COUNTIES LATE AFTERNOON.
OFF LAKE ERIE TONIGHT...NORTHWEST FLOW WILL MAINTAIN A FEW SNOW
SHOWERS ACROSS THE CHAUTAUQUA RIDGE. THERE MAY BE A BRIEF WINDOW
THIS EVENING WHERE SOME UPSTREAM CONNECTION TRIES TO DEVELOP FROM
LAKE HURON...BUT THIS WILL BE SHORT LIVED AS HIGH PRESSURE
BUILDING OVER THE CENTRAL LAKES QUICKLY SHUTS OFF ANY UPSTREAM
LAKE EFFECT. EXPECT ADDITIONAL AMOUNTS OF 1-3 INCHES IN PERSISTENT
BANDS CENTERED ON SKI COUNTRY.
OFF LAKE ONTARIO TONIGHT...LAKE EFFECT WILL INITIALLY BE VERY
DISORGANIZED IN NORTHWEST FLOW DUE TO THE LINGERING EFFECTS OF
DAYTIME HEATING. BY MID TO LATE EVENING EXPECT A BROKEN BAND TO
CONCENTRATE TO THE SOUTHEAST OF THE LAKE ACROSS WAYNE...N CAYUGA
AND FAR SOUTHERN OSWEGO COUNTIES. SOME OF THIS MAY CLIP THE
NORTHERN AND EASTERN SUBURBS OF ROCHESTER AS WELL. MAY SEE ANOTHER
2-3 INCHES LOCALLY FROM THIS OVERNIGHT.
OUTSIDE OF LAKE EFFECT AREAS...SCATTERED SNOW SHOWERS MAY PRODUCE
ANOTHER DUSTING OF ACCUMULATION THIS EVENING BEFORE ENDING
OVERNIGHT. SNOW SHOWERS MAY LINGER THROUGH THE NIGHT ACROSS THE
HIGHER TERRAIN EAST OF LAKE ONTARIO AS A POCKET OF DEEPER MOISTURE
LINGERS BEHIND THE DEPARTING LOW. MODIFIED ARCTIC AIR WILL SEND
TEMPS BELOW AVERAGE TONIGHT...ALTHOUGH MOS TEMPS LOOK A LITTLE TOO
COLD GIVEN EXTENSIVE LAKE EFFECT CLOUDS. EXPECT LOWS GENERALLY IN
THE MID TEENS...WITH SINGLE DIGITS EAST OF LAKE ONTARIO.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
ON MONDAY...THE LAKE SNOWS EAST-SOUTHEAST OF THE LAKES WILL
GRADUALLY DIMINISH DUE TO BOTH DIURNAL INFLUENCES AND RIDGING
BUILDING EAST FROM THE CENTRAL GREAT LAKES...WHICH WILL PROVIDE MUCH
DRIER AIR AND INCREASING AMOUNTS OF SUBSIDENCE. EXPECT ONLY A FEW
LEFTOVER LIGHT SNOW SHOWERS AND/OR FLURRIES TO BE LEFTOVER BY MONDAY
EVENING...WITH THIS ACTIVITY THEN FALLING APART COMPLETELY DURING
MONDAY NIGHT AS THE AXIS OF THE LOW LEVEL RIDGE MOVES OVERHEAD.
ELSEWHERE...CONDITIONS WILL LARGELY BE JUST DRY AND COLD...WITH WELL
BELOW NORMAL TEMPERATURES CONTINUING GIVEN THE RATHER CHILLY AIRMASS
THAT WILL BE IN PLACE AT THE LOW LEVELS. EXPECT HIGHS TO BE ONLY IN
THE LOWER TO MID 20S ON MONDAY...WITH WIDESPREAD LOWS BETWEEN 10 AND
15 THEN FOLLOWING FOR MONDAY NIGHT AS THE RIDGE AXIS CRESTS OVERHEAD
AND PROVIDES GOOD CONDITIONS FOR RADIATIONAL COOLING. THE NORTH
COUNTRY WILL BE EVEN COLDER...WITH LOWS FALLING TO AROUND ZERO OR
PERHAPS EVEN SLIGHTLY BELOW ACROSS MOST OF JEFFERSON AND LEWIS
COUNTIES.
AFTER THAT...THE SURFACE RIDGE WILL SLIDE EAST TO THE NEW ENGLAND
COAST AND THEN OFFSHORE TUESDAY AND WEDNESDAY...WHILE BROAD UPPER
RIDGING BUILDS EAST ACROSS THE GREAT LAKES AND NORTHEAST. ALL OF
THIS WILL RESULT IN A DEEPENING SOUTHWESTERLY FLOW OF PROGRESSIVELY
MILDER AIR OVERSPREADING THE AREA DURING TUESDAY...THEN CONTINUING
RIGHT THROUGH WEDNESDAY. WHILE THIS WARM ADVECTION PATTERN WILL
RESULT IN SOME MID AND UPPER LEVEL CLOUDS PASSING ACROSS THE AREA
FROM TIME TO TIME...BOTH DAYS STILL LOOK TO REMAIN DRY WITH THE BEST
LIFT AND MOISTURE REMAINING WELL TO OUR NORTH AND WEST IN
ASSOCIATION WITH A SURFACE WARM FRONT LIFTING ACROSS THE
WESTERN/CENTRAL LAKES AND INTO ONTARIO PROVINCE.
UNDER THIS WARM AIR ADVECTION REGIME...925 MB TEMPS WILL STEADILY
CLIMB THROUGH MIDWEEK...EVENTUALLY REACHING THE +4C T0 +9C RANGE BY
WEDNESDAY AFTERNOON. COUPLED WITH A GOOD SOUTHWESTERLY LOW LEVEL
FLOW AND AT LEAST SOME PARTIAL SUNSHINE...THIS WILL ALLOW FOR
DAYTIME HIGH TEMPERATURES TO REBOUND BACK TO MORE NORMAL LEVELS IN
THE MID 30S TO LOWER 40S ON TUESDAY...BEFORE REALLY SOARING INTO THE
MID AND UPPER 50S ACROSS MUCH OF THE AREA ON WEDNESDAY. IN FACT...
THE NORMALLY WARM SPOTS OF THE GENESEE VALLEY/FINGER LAKES MAY EVEN
REACH OR BREAK 60F ON WEDNESDAY.
THE MILD WEATHER WILL THEN CONTINUE THROUGH WEDNESDAY NIGHT AS THE
AFOREMENTIONED SOUTHWESTERLY FLOW REMAINS ANCHORED ACROSS OUR
AREA...IN ADVANCE OF A COLD FRONT SLOWLY APPROACHING FROM THE
CENTRAL GREAT LAKES. WHILE THIS FEATURE WILL BRING A NORTHWEST TO
SOUTHEAST INCREASE IN CLOUD COVER AS IT PUSHES INTO SOUTHERN ONTARIO
LATER IN THE NIGHT...BOTH THE 00Z GFS/ECMWF NOW SUGGEST THAT IT WILL
REMAIN JUST FAR ENOUGH TO OUR NORTH FOR OUR AREA TO REMAIN LARGELY
DRY THROUGH THE NIGHT...HENCE WILL KEEP POPS AT THE SLIGHT CHANCE OR
LOWER FOR WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
WITH THE 00Z GFS/GEM/ECMWF NOW IN MUCH BETTER AGREEMENT THAT THE
AFOREMENTIONED COLD FRONT WILL SLOWLY OOZE ACROSS OUR AREA THURSDAY
AND THURSDAY NIGHT AS IT BECOMES ORIENTED INCREASINGLY PARALLEL TO
THE LARGE-SCALE UPPER LEVEL FLOW...WILL FOCUS CHANCE POPS FOR THE
FRONTAL PASSAGE ON THESE TWO PERIODS...ALONG WITH SOMEWHAT COOLER
BUT STILL ABOVE NORMAL TEMPS ON THURSDAY GIVEN THE INCREASED AMOUNT
OF CLOUD COVER AND PRECIP.
AFTER THAT...THE VARIOUS GUIDANCE PACKAGES DIVERGE AGAIN SOMEWHAT
WITH RESPECT TO HOW QUICKLY THE FRONT DEPARTS OUR AREA TO THE
SOUTHEAST...AS WELL AS IN HOW FAST SIGNIFICANTLY COLDER/DRIER AIR
SUBSEQUENTLY OVERSPREADS OUR AREA FROM THE NORTHWEST FOLLOWING THE
FRONTAL PASSAGE. ALL OF THIS APPEARS TO ULTIMATELY BE TIED TO THE
STRENGTH AND DEPTH OF THE UPPER TROUGH PASSING ACROSS ONTARIO AND
QUEBEC LATE IN THE WEEK...WITH A FASTER/FLATTER TROUGH ALLOWING FOR
A FASTER PROGRESSION ALA THE GFS...AND A SLOWER/SLIGHTLY MORE
AMPLIFIED TROUGH RESULTING IN A SLOWER EVOLUTION MORE ALONG THE
LINES OF THE ECMWF/GEM. AT THIS DISTANT JUNCTURE...WILL JUST OPT TO
KEEP THINGS SIMPLE AND PORTRAY A GENERAL NORTHWEST-SOUTHEAST
DECREASE IN CHANCE POPS ON FRIDAY FOLLOWING THE FRONTAL PASSAGE...
THEN A RETURN TO SEASONABLY COLDER AND DRY CONDITIONS FOR SATURDAY
WITH THE COLDER AIRMASS PRESENTLY APPEARING TO BE TOO DRY TO SUPPORT
MUCH LAKE EFFECT.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
EXPECT MAINLY VFR/MVFR CONDITIONS TODAY...WITH PERIODS OF IFR OR
LOWER IN SNOW SHOWERS. MOST SIGNIFICANT BAND WILL DROP SOUTHWARD
AND WEAKEN LATE MORNING INTO THIS AFTERNOON...TEMPORARILY IMPACTED
IAG/ROC/BUF. EXPECT IMPROVING CONDITIONS BEHIND THIS.
THE SNOW SHOWERS WILL GRADUALLY DIMINISH TONIGHT...PERSISTING THE
LONGEST SOUTHEAST OF THE LAKES IN SOME LINGERING LAKE EFFECT. A MIX
OF VFR AND MVFR CIGS WILL CONTINUE WITH MVFR MORE PREVALENT ACROSS
THE HIGHER TERRAIN.
OUTLOOK...
MONDAY...VFR/MVFR WITH SCATTERED SNOW SHOWERS.
TUESDAY AND WEDNESDAY...VFR.
THURSDAY...MVFR/VFR. A CHANCE OF SHOWERS.
&&
.MARINE...
WINDS HAVE DIMINISHED TO BELOW GALE EARLY THIS MORNING AS THE STRONG
LOW PRESSURE SYSTEM CONTINUES TO PULL AWAY INTO ATLANTIC CANADA. A
SECONDARY COLD FRONT WILL DROP SOUTH ACROSS THE LOWER LAKES TODAY
WITH MODERATE WESTERLIES BECOMING NORTHWEST. THIS WILL MAINTAIN
SMALL CRAFT ADVISORY CONDITIONS THROUGH THIS EVENING ON BOTH LAKES
ERIE AND ONTARIO. WAVES WILL BEGIN TO COME DOWN LATER THIS EVENING
IN MOST LOCATIONS...EXCEPT AT THE SOUTHEAST CORNER OF LAKE ONTARIO
FROM ABOUT ROCHESTER TO MEXICO BAY WHERE FAVORABLE FETCH WILL
MAINTAIN SMALL CRAFT ADVISORY CONDITIONS THROUGH MONDAY IN NORTHWEST
FLOW. HIGH PRESSURE WILL BUILD OVER THE LOWER LAKES MONDAY NIGHT
WITH WINDS BECOMING LIGHT.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ012-020-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 10 PM EST MONDAY FOR
LOZ043-044.
SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LOZ042-045.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL/HITCHCOCK
MARINE...APFFEL/HITCHCOCK