Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/10/13
AREA FORECAST DISCUSSION
NWS TUCSON AZ
215 PM MST FRI FEB 8 2013
.SYNOPSIS...AN APPROACHING PACIFIC STORM SYSTEM WILL BRING STRONG
AND GUSTY WINDS TODAY WITH AREAS OF BLOWING DUST POSSIBLE. COLDER
TEMPERATURES WITH RAIN AND SNOW SHOWERS SATURDAY. IT WILL REMAIN
COLD WITH A FEW SHOWERS TO START NEXT WEEK BEFORE A STRONG WARMING
TREND OCCURS AROUND THE MIDDLE OF THE WEEK.
&&
.DISCUSSION...WINDS CONTINUING TO INCREASE THIS AFTERNOON WITH
SOUTHERN PORTION OF FRONTAL BOUNDARY STARTING TO LOSE SOME INTEGRITY
JUST WEST OF US. BECOMING WINDY IN MANY LOCATIONS BUT STILL NOT
THREATENING WIND ADVISORY CRITERIA SO FAR. EXPECTING ONE OR TWO
SPOTS TO BRIEFLY CROSS THE SUSTAINED 30 MPH VALLEY 35 MPH MOUNTAIN
THRESHOLD BEFORE THE AFTERNOON IS OVER...BUT STILL NOT EXPECTING TO
QUITE REACH WIDESPREAD ADVISORY CONDTIONS.
MID LEVEL DYNAMICS AND COLD AIR FROM STRONG LOW PUSHING INTO ARIZONA
TONIGHT AND SATURDAY. MAIN TROUGH INFLECTION WILL COME TOGETHER WITH
MOISTURE MAINLY AFTER 12Z SATURDAY FOR OUR PART OF THE STATE WITH A
SIGNIFICANT UPSLOPE COMPONENT. 18Z NAMDNG5 AND 12Z ECMWF LOOK SOLID
AND CONTINUE TO HANDLE THINGS WELL. LATEST HRRR SHOWING ISOLATED
DEVELOPMENT WEST AND NORTHWEST OF TUCSON BETWEEN 04Z-08Z WHICH FITS
WELL.
SHOWERS INCREASING FROM THE WEST DURING THE DAY SATURDAY. NOT
EXCESSIVE STORM TOTAL PRECIP WITH QPF GENERALLY RANGING FROM .15 IN
VALLEYS TO .5 IN MOUNTAINS. COLD AIR ALREADY PUSHING IN TONIGHT AND
BY THE TIME THE BEST PRECIP GETS HERE AFTER 12Z SNOW LEVELS ARE
EXPECTED TO RANGE FROM 3000 TO 4000 FEET ACROSS MOST OF THE AREA. A
WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR SATURDAY ABOVE 4000
FEET...EVEN THOUGH HIGHER ELEVATIONS MAY STRUGGLE TO END UP WITH
ENOUGH SNOW TO MEET CRITERIA. THE PRIME AREA OF CONCERN IS 3500 TO
5500 FEET. PLEASE SEE PHXWSWTWC FOR DETAILS.
SOME CLEARING SATURDAY NIGHT INTO SUNDAY MORNING WITH SOLID COLD AIR
IN PLACE...WITH WIDESPREAD NEAR OR BELOW FREEZING TEMPERATURES AREAS
OF FROST ARE A CONCERN.
ON MONDAY A REINFORCING SHOT OF COLD AIR WITH A SYSTEM DIGGING DOWN
THE BACK SIDE OF THE MEAN TROUGH POSITION FROM THE NORTH. RESIDUAL
BOUNDARY LAYER MOISTURE SHOULD GIVE IT ENOUGH TO GENERATE A FEW MORE
RAIN AND SNOW SHOWERS ACROSS THE AREA AS SNOW LEVELS REMAIN LOW.
OVERALL SATURDAY THROUGH TUESDAY WE EXPECT A SUSTAINED PERIOD OF
COLD TEMPERATURES WITH AT LEAST 4 DAYS WHERE TEMPERATURES DON`T
CLIMB OUT OF THE 50S. SOME CONCERNS WITH LOW TEMPERATURES...WITH THE
POTENTIAL OF A WIDESPREAD FREEZE FROM TUCSON THROUGH THE LOWER
DESERTS...AND WIDESPREAD HARD FREEZE AT HIGHER ELEVATION LOCATIONS
FROM SUNDAY MORNING THROUGH WEDNESDAY MORNING.
&&
.AVIATION...HIGH CLOUDS WILL THIN OVER THE AREA THIS EVENING
BECOMING SCT250 BY 09/05Z. LOWER CLOUDS BETWEEN BKN050 AND BKN100
WILL DEVELOP 09/10Z THROUGH 09/20Z WITH SCATTERED SHOWERS. SOUTH TO
SOUTHWEST SURFACE WIND 15-25 KT WITH GUSTS TO 35 KT WILL EASE AFT
09/03Z TO SOUTHWEST 10-15 KT. WIND BECOMING WEST 15-20 KT AFT
09/20Z. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A STRONG LOW PRESSURE SYSTEM OVER CALIFORNIA WILL
MOVE ACROSS ARIZONA SATURDAY...WITH A SECOND SYSTEM FOLLOWING MONDAY
INTO EARLY TUESDAY. GUSTY SOUTH TO SOUTHWEST WINDS WILL EASE THIS
EVENING AND INCREASE AGAIN OUT OF THE WEST TO NORTHWEST
SATURDAY...ESPECIALLY FROM TUCSON EAST. SHOWERS WILL DEVELOP LATE
TONIGHT AND CONTINUE INTO MID DAY SATURDAY WITH THE SNOW LEVEL
DROPPING TO NEAR 3000 FT. THE SECOND SYSTEM WILL RESULT IN A SLIGHT
CHANCE OF SHOWERS ON MONDAY MAINLY TO THE EAST OF TUCSON AND OVER
HIGHER TERRAIN. TEMPERATURES SATURDAY THROUGH TUESDAY WILL BE 10-15
DEGREES COOLER THAN NORMAL. WARMER CONDITIONS WILL RETURN TO THE
AREA LATE NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...WINTER WEATHER ADVISORY SATURDAY
FROM 5 AM TO 5 PM MST ABOVE 4000 FEET INCLUDING
AZZ503-504-506>515.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
MEYER/CERNIGLIA
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
934 AM PST FRI FEB 8 2013
.SHORT TERM DISCUSSION...
WV IMAGERY THIS MORNING SHOWS A LARGE UPPER LOW NOW CENTERED OVER
SOCAL WHICH BEEN DIVING SOUTH ALONG THE WEST COAST AND IS
BEGINNING TO SWING INLAND. AREA RADARS SHOW A FEW SNOW SHOWERS
ALONG THE SIERRA CREST...OTHERWISE THE OVERNIGHT ACTIVITY HAS FIZZLED.
SCATTERED WRAP-AROUND SHOWERS WILL BE POSSIBLE ALONG THE SIERRA
CREST TODAY INTO THIS EVENING...MOSTLY SOUTH OF I80.
OTHERWISE...DRY AND COOL WEATHER WILL MOVE IN TODAY AND LOOKS TO
CONTINUE FOR THE FORESEEABLE FUTURE WITH PERSISTENT DRY NORTHERLY
FLOW ALOFT.
HAVE UPDATED THE TODAY/TONIGHT FORECAST TO TRIM POPS AND BRING
THEM MORE IN LINE WITH MODEL GUIDANCE. THE RUC WAS THE BEST
PERFORMER WITH THE CONVECTIVE SHOWERS YESTERDAY...SO HAVE LEANED
ON ITS GUIDANCE FOR TODAY. -DVC
.PREVIOUS DISCUSSION...ISSUED 242 AM PST...
SATELLITE IMAGERY INDICATED COLD UPPER LOW CENTER NOW SOMEWHERE
NEAR THE NORTH COAST OF CALIFORNIA ON ITS WAY TO THE SOUTH CENTRAL
PART OF THE STATE WHERE IT IS FORECAST TO BE BY MID DAY TODAY. A
SHORTWAVE DISTURBANCE PIVOTING AROUND THE LOW HAS BROUGHT LIGHT
SHOWERS TO SHASTA AND TEHAMA COUNTIES OVER THE LAST FEW HOURS.
MOST OF THE INSTABILITY AND MOISTURE WITH THIS LOW HOWEVER HAS
REMAINED OFFSHORE AND IS EXPECTED TO REMAIN OFFSHORE THROUGH THE
DAY TODAY. THEREFORE...ONLY ISOLATED SHOWERS ARE EXPECTED OVER THE
FORECAST AREA THIS MORNING WITH THIS SHOWER ACTIVITY EXPECTED TO
ERODE FROM THE NORTH AS THE MAIN LOW DROPS SOUTHWARD. AS THE LOW
DROPS SOUTHWARD INTO SOCAL THIS AFTERNOON...ANY SHOWER THREAT
SHOULD BE CONFINED TO THE NORTHERN SIERRA AND NORTHERN SAN JOAQUIN
VALLEY. THE NORTH AND WEST PORTIONS OF THE FORECAST AREA SHOULD
SEE SOME CLEARING SKIES. OVERALL AIRMASS WILL NOT BE MUCH WARMER
TODAY BUT MORE SUN SHOULD ALLOW FOR A SLIGHT WARMING IN AREAS THAT
CLEAR.
THE UPPER LOW SHIFTS INTO THE GREAT BASIN TONIGHT BUT WITH WRAP
AROUND MOISTURE POTENTIAL...CAN NOT RULE OUT A SLIGHT THREAT OF
SHOWERS OVER THE SIERRA. SURFACE HIGH PRESSURE PUSHING INTO THE
PACIFIC NORTHWEST WILL BRING A MODERATE NORTHERLY SURFACE GRADIENT
TO NORTHERN CALIFORNIA BY SATURDAY MORNING. CURRENT MODEL
PROJECTIONS SHOW ABOUT AN 8MB SURFACE GRADIENT FROM MFR TO SAC. THIS
SURFACE GRADIENT COMBINED WITH NORTHERLY UPPER FLOW WILL BRING
BREEZY NORTH WINDS TO THE REGION WHICH WILL LAST THROUGH THE
WEEKEND. CLEARER SKIES WILL MEAN COOLER TEMPERATURES SATURDAY
MORNING BUT THE BREEZY WINDS WILL LIKELY KEEP MINIMUM TEMPERATURES
ELEVATED A BIT. MOST VALLEY LOCATIONS ARE FORECAST TO REMAIN ABOVE
FREEZING WITH DRY NORTHERLY FLOW MAKING FOG FORMATION UNLIKELY. A
HIGH AMPLITUDE UPPER LEVEL RIDGE OVER THE EASTERN PACIFIC WILL BEGIN
TO PUSH INLAND SATURDAY AFTERNOON AS THE UPPER LOW CONTINUES
EASTWARD. THIS WILL BRING IN A WARMER AIRMASS RESULTING IN DAYTIME
HIGHS PUSHING UPWARDS TO RIGHT AROUND NORMAL FOR THIS TIME OF YEAR.
STILL MORE WARMING IS ON TAP FOR SUNDAY AS THE HIGH PRESSURE RIDGE
PUSHES FARTHER INLAND WITH A BIT MORE WARMING ON MONDAY. SURFACE
GRADIENTS WEAKEN ON MONDAY BRINGING LIGHTER NORTH WINDS WITH DAYTIME
HIGHS WARMING TO SEVERAL DEGREES ABOVE NORMAL.
.EXTENDED DISCUSSION (TUESDAY THROUGH FRIDAY)
DRY WEATHER WITH SLIGHTLY ABOVE NORMAL TEMPERATURES SHOULD
CONTINUE THROUGH THE EXTENDED PERIOD AS DRY NORTHERLY FLOW ALOFT
PERSISTS. STRONG HIGH PRESSURE WILL REMAIN ENTRENCHED ALONG THE
EASTERN PACIFIC...FORCING THE STORM TRACK WELL TO OUR NORTH AND
EAST. THERE MAY ALSO BE THE POSSIBILITY OF SOME PATCHY EARLY
MORNING FOG EARLY NEXT WEEK. THE MEDIUM-RANGE MODELS ARE HINTING
AT AN UPPER TROUGH DROPPING SOUTH INTO THE GREAT BASIN LATE NEXT
WEEK. IF THIS DOES INDEED HAPPEN...THIS "INSIDE SLIDER" COULD
BRING BREEZY NORTH WINDS AND A SLIGHT COOLING IN TEMPERATURES
ACROSS THE FORECAST AREA LATE NEXT WEEK. DANG
&&
.AVIATION...
COLD UPPER LOW IN THE VCNTY WILL SHIFT SEWD TODAY...WITH
WRAP-AROUND SCATTERED -SHSN AND MVFR CIGS/VSBYS OVER SIERNEV...
MAINLY S OF I-80. OTHERWISE...LOCAL MVFR CIGS OVER SAC VLY AND
NRN SAN JQN VALLEY DURING MORNING WILL ERODE GIVING WAY TO VFR
CONDITIONS AND MAINLY CLEARING SKIES IN THE VALLEY...NRN MTNS AND
COASTAL RANGE AS DRY NLY WIND DEVELOPS. NW WINDS 10-15 KT WITH
LOCAL GUSTS 20-30 KTS EXPECTED THROUGHOUT MUCH OF THE INTERIOR
VALLEY DURING THE AFTN. NLY FLOW CONTINUES TONITE KEEPING
FOG/STRATUS FROM FORMING IN THE VALLEY. GENERALLY DECREASING
CLOUDINESS OVER SIERNEV DUE TO DOWNSLOPE FLOW...HOWEVER CLOUDS MAY
LINGER NEAR SIERNEV CREST.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
412 AM PST FRI FEB 8 2013
.DISCUSSION...AS OF 4:12 AM PST FRIDAY...SCATTERED SHOWERS
CONTINUE TO STREAM ONSHORE AT THIS HOUR...MAINLY FROM THE GOLDEN
GATE SOUTHWARD WITH LITTLE OR NO SHOWER ACTIVITY EXPECTED FOR THE
NORTH BAY. SHOWER ACTIVITY WILL BE MOST NUMEROUS THIS MORNING AND
THEN MORE OR LESS END FOR THE BAY AREA BY MIDDAY. SHOWER THREAT
WILL LINGER MOST OF THE DAY FOR THE HILLS OF MONTEREY AND SAN
BENITO COUNTY. MESOSCALE MODELS SUCH AS THE RAP AND HRRR ARE
DEPICTING CURRENT SHOWER ACTIVITY QUITE WELL WHILE THE NAM
INITIALIZED TOO DRY BUT HAS THE LOCATION OF THE UPPER LOW CORRECT.
AS WOULD BE EXPECTED UNDER A SHOWERY REGIME RAIN TOTALS HAVE BEEN
VARIED WITH A FEW HUNDREDTHS FOR THE INLAND VALLEYS AND IN EXCESS
OF 0.50 FOR SOME OF THE COASTAL HILLS. OTHER ITEM TO CONSIDER
WILL BE SNOW LEVELS WITH OBSERVATION NETWORK INDICATING TEMPS IN
THE HILLS AT OR BELOW FREEZING DOWN TO AROUND 2000 FEET. SNOW
FLAKES AS LOW AS 1500 FEET WILL BE POSSIBLE IN HEAVIER SHOWERS
THIS MORNING...ANY ACCUMULATION OF NOTE WILL BE CONFINED TO AREAS
ABOVE 2500 TO 3000 FEET WITH A FEW INCHES MOST LIKELY OVER THE
HIGHER TERRAIN OF COASTAL MONTEREY COUNTY.
BY LATER THIS AFTERNOON ANY SHOWER THREAT WILL BE CONFINED TO
MONTEREY AND SAN BENITO COUNTY...AND MAINLY OVER THE HILLS WHILE
THE BAY AREA WILL SEE PARTLY CLOUDY SKIES BUT WITH COOL AFTERNOON
HIGHS IN THE 50S.
FOR TONIGHT THE UPPER LOW RESPONSIBLE FOR THE INSTABILITY SHOWERS
WILL SHIFT EASTWARD. HOWEVER A FAIRLY STRONG GRADIENT WILL REMAIN
IN PLACE WITH BREEZY NORTH WINDS EXPECTED IN THE HILLS AND JUST
ABOVE THE BOUNDARY LAYER. THIS WILL HELP TO KEEP TEMPERATURES FROM
GETTING TOO COLD...SO ONLY EXPECTING SOME PATCHY FROST BY SATURDAY
MORNING.
HIGH PRESSURE BUILDS SATURDAY THROUGH NEXT WEEK WITH NO RAIN IN
THE FORECAST. WILL HAVE TO MONITOR FOR SOME COLD TEMPS ON SUNDAY
MORNING WITH WINDS ALOFT SLIGHTLY LIGHTER. HOWEVER AT THIS TIME
NOT EXPECTING TO SEE COLD TEMPS LIKE WE SAW EARLIER IN JANUARY.
THERE WILL BE A CHILL IN THE AIR BUT NOT EXPECTING WIDESPREAD
SUB-FREEZING TEMPS.
HIGH PRESSURE WILL STRENGTHEN NEXT WEEK WITH A GRADUAL WARMING AND
DRYING TREND. OFFSHORE PRESSURE GRADIENTS SHOULD KEEP THE AIRMASS
FAIRLY WELL MIXED WITH ONLY PATCHY VALLEY FOG IN THE MORNINGS.
OTHERWISE EXPECT PLEASANT MID-WINTER WEATHER...ALTHOUGH MORE
RAIN AND MOUNTAIN SNOW IS REALLY NEEDED ACROSS NORTHERN CALIFORNIA.
&&
.AVIATION...AS OF 9:50 PM PST THURSDAY...A COLD UPPER TROUGH WAS
SETTLING OVER THE AREA ON THURSDAY EVENING. THIS TROUGH WILL
PRODUCE SCATTERED SHOWERS FROM KSFO AND KOAK SOUTHWARD ON THURSDAY
NIGHT...CONTINUING THROUGH MID MORNING FRIDAY. THERE IS ALSO A
SLIGHT CHANCE OF THUNDERSTORMS. CIGS WILL DROP TO MVFR DURING
SHOWERS. CONDITIONS WILL IMPROVE BRIEFLY TO VFR IN BETWEEN
SCATTERED SHOWERS. SHOWER ACTIVITY IS FORECAST TO MOVE SOUTH OF
THE AREA BY 18Z FRIDAY AND VFR CONDITIONS ARE EXPECTED THEREAFTER.
WINDS WILL BE LIGHT FROM THE SOUTH AND SOUTHWEST OVERNIGHT...THEN
VEER TO THE WEST AND NORTHWEST BY LATE FRIDAY MORNING AND INCREASE
FRIDAY AFTERNOON.
VICINITY OF KSFO...SCATTERED SHOWERS PRODUCING MVFR CIGS THROUGH
ABOUT 15Z FRIDAY MORNING. SHOWER ACTIVITY SHOULD MOVE ENTIRELY SOUTH
OF THE AREA BY 18Z FRIDAY AND VFR CONDITIONS ARE EXPECTED
THEREAFTER. WINDS WILL BE LIGHT FROM THE WSW THROUGH EARLY FRIDAY
MORNING...THEN VEER TO THE NORTHWEST AND INCREASE BY MIDDAY
FRIDAY.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...SCATTERED SHOWERS PRODUCING MVFR
CIGS THROUGH 18Z FRIDAY MORNING. VFR CONDITIONS THEREAFTER. WINDS
LIGHT FROM THE SOUTH ON FRIDAY NIGHT...BECOME WESTERLY ON FRIDAY
MORNING AND INCREASING BY EARLY FRIDAY AFTERNOON.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
SCA...PT ARENA TO PT REYES 0-10 NM FROM 10 AM
SCA...PT REYES TO PIGEON PT 0-10 NM FROM NOON
SCA...ROUGH BAR ADVISORY FOR SF BAR UNTIL 3 PM
&&
$$
PUBLIC FORECAST: RWW
AVIATION/MARINE: DYKEMA
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
1004 PM PST THU FEB 7 2013
.SHORT TERM DISCUSSION...
UPPER TROUGH IS MOVING THROUGH NORCAL THIS EVENING. THE SYSTEM IS
MOISTURE STARVED AND PRECIP AMOUNTS HAVE BEEN ON THE LOW SIDE FOR
THE MOST PART. THE PLACES THAT HAVE RECEIVED THE MOST HAVE BEEN
FROM WILLOW TO REDDING WHERE CONVECTION FLARED UP DURING THE LATE
AFTERNOON/EARLY EVENING REDDING HAS PICKED 0.21 INCHES AS OF 9 PM
AND ALSO OVER THE HIGHER TERRAIN WHERE BLUE CANYON HAS RECEIVED 3
TO 4 INCHES OF SNOW. SEVERAL OF THE THUNDERSTORMS EARLIER IN THE
EVENING WERE PRODUCING SMALL HAIL WITH ACCUMULATION UP TO AN INCH
IN A FEW SPOTS.
MAIN ENERGY WITH STORM WILL DROP SOUTH OF THE AREA THROUGH CENT
CAL TONIGHT AND SOCAL TOMORROW. FEEL NAM AND RUC HAVE A GOOD
HANDLE ON THIS SYSTEMS EVOLUTION AND BOTH MODELS SHOW VERY LITTLE
PRECIP OVER THE SAC VALLEY OVERNIGHT AND TOMORROW. BETTER CHANCES
WILL DEVELOP AFTER MIDNIGHT STOCKTON/MODESTO AND SRN SIERRA AS
DISTURBANCE PIVOTS THROUGH CENT CAL. HAVE UPDATED FORECAST TO
LOWER POPS BACK INTO THE SCATTERED RANGE FOR MOST OF THE SAC
VALLEY INCLUDING SACRAMENTO OVERNIGHT...BUT RAISED THEM INTO THE
NUMEROUS CATEGORY OVER THE SAN JOAQUIN VALLEY. HAVE ENDED THE
WINTER WX ADV FOR THE SIERRA...AS PRECIP HAS DIMINISHED AND ONLY
EXPECT UP TO AN ADDITIONAL INCH OF SNOW. SNOW LEVELS ARE AROUND
3000 FEET.
PREVIOUS DISCUSSION...
A COLD UPPER LOW AND ASSOCIATED RAIN/SNOW SHOWERS WILL MOVE
SOUTHEASTWARD ACROSS THE AREA TONIGHT AND EXIT TO THE EAST
TOMORROW. DRY NORTHERLY FLOW WILL SET IN FOR THE REMAINDER OF THE
WEEKEND AND INTO NEXT WEEK BRINGING FAIR WEATHER AND SEASONAL
TEMPERATURES.
THE CENTER OF THE UPPER LOW IS PROGGED TO SLIDE OVER INTERIOR
NORCAL TONIGHT. HOWEVER...THE BEST LIFT WILL SKIRT OUR AREA AS
THE JETSTREAK DIVES FURTHER SOUTH THROUGH CENTRAL AND SOUTHERN
CALIFORNIA. PRECIP WILL THUS BE LIMITED TO INSTABILITY SHOWERS AS
RELATIVELY STEEP LAPSE RATES PERSIST AT THE LOWER LEVELS AND LOW-
LEVEL MOISTURE LINGERS. SOME CENTRAL VALLEY THUNDERSTORM ACTIVITY
IS POSSIBLE INTO THE EVENING BEFORE THE LOSS OF DAYTIME HEATING
REDUCES THE LOW-LEVEL CAPE AND ENDS THE THREAT. MODELS VARY WITH
HANDLING THE PLACEMENT OF OVERNIGHT SHOWERS...BUT GENERAL
AGREEMENT IS THAT PRECIP AMOUNTS WILL BE LIGHT WITH MOST SHOWER
ACTIVITY CONFINED TO THE HIGHER ELEVATIONS. SNOW LEVELS WILL
CONTINUE TO DROP...LOCALLY AS LOW AS 2000 FEET OVERNIGHT. ONLY A
FEW ADDITIONAL INCHES ARE EXPECTED IN THE SIERRA...ALTHOUGH
LOCALLY HIGHER AMOUNTS ARE STILL POSSIBLE GIVEN THE CONVECTIVE
NATURE OF THE PRECIP. AS SUCH...HAVE CANCELLED THE WINTER WEATHER
ADVISORY OVER THE COASTAL MOUNTAINS AND HASTENED THE ENDING TIME
OF THE ADVISORY OVER THE WEST SLOPE OF THE SIERRA.
SHOWERS WILL DISSIPATE OVER THE AREA TOMORROW AS THE LOW SHIFTS
EASTWARD. THE CENTRAL VALLEY LOOKS TO DRY OUT QUICKLY WITH A
NORTHERLY PRESSURE GRADIENT SETTING UP BREEZY NORTHERLY
WINDS...PARTICULARLY IN THE WESTERN SAC VALLEY. SNOW SHOWERS MAY
LINGER INTO THE AFTERNOON OVER THE SIERRA (MOSTLY SOUTH OF
I80)...BUT TOTALS WILL BE SPOTTY AND ON THE LIGHT SIDE.
FOR THE WEEKEND...DRY NORTHERLY FLOW ALOFT WILL BRING FAIR
WEATHER AND MOSTLY CLEAR SKIES. DAYTIME TEMPERATURES WILL SLOWLY
WARM TO AROUND AVERAGE FOR THIS TIME OF YEAR...WHILE OVERNIGHT
LOWS REMAIN COOL WITH FROSTY MORNINGS POSSIBLE. -DVC
.EXTENDED DISCUSSION (MONDAY THROUGH THURSDAY)
DRY WEATHER PATTERN REESTABLISHES ITSELF FOR NORCAL AS DRY NLY FLOW
PREVAILS OVER THE FORECAST AREA THROUGH THE EFP. LOW PRESSURE OVER
THE GREAT BASIN EARLY IN THE EFP RESULTS IN NLY FLOW FROM B.C. AND
THE PAC NW WITH CONTINUED COLD/CHILLY TEMPS...ESPECIALLY MON
MORNING WITH COLD AIR FROM THE GREAT BASIN SPREADING INTO INTERIOR
NORCAL. HOWEVER...THE AIR MASS MODIFIES TUE/WED OVER NORCAL AS A
SHORT WAVE TROF FLATTENS THE AMPLIFIED RIDGE OVER WRN CANADA AND
THE FLOW INTO NORCAL COMES INTO THE AREA FROM A LOWER LATITUDE.
THIS SHORT WAVE PROGRESSES INTO THE GREAT BASIN AND RE-AMPLIFIES
THE W COAST RIDGE BRINGING MORE COLD AIR DOWN FROM THE YUKON/B.C
AREA BY THU MORNING FOR ANOTHER ROUND OF CHILLY MIN TEMPS AND
BREEZY N TO NELY WINDS.
AFTER THE WINDS DIMINISH TUE/WED SOME MORNING PATCHY FOG/FROST IS
POSSIBLE IN THE SRN SAC VLY SWD INTO THE DELTA AND SAN JQN VLY.
WHILE THE MIN TEMPS WILL CONTINUE TO RUN SEVERAL DEG BELOW
NORMAL...MAX TEMPS WILL RUN A LITTLE ABOVE NORMAL...IF NOT SEVERAL
DEG ABOVE NORMAL WHERE FAVORABLE ADIABATIC WARMING EFFECTS OCCUR.
JHM
&&
.AVIATION...
CD UPR LOW WL MOV S ACRS INTR NORCAL TNGT INTO FRI. MNLY VFR CONDS
EXC LCL MVFR/IFR CONDS POSS IN SHWRS NXT 24 HRS...MNLY OMTNS. SN
LVLS GENLY AOA 020 AMSL. SWLY FLOW ALF BCMG NLY FRI WITH LCL NLY SFC
WND GSTS TO 25 KTS FRI AFTN AND FRI NGT.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1016 AM MST FRI FEB 8 2013
.UPDATE...
&&
.SHORT TERM...SOUTHERLY WINDS BEGINNING TO MIX TO THE SURFACE
ACROSS THE PALMER DIVIDE...SOUTHERN FOOTHILLS AND THE SOUTHERN
SECTIONS OF THE DENVER AREA. A RECENT GUST OF 29 KTS OCCURRED AT
APA. SOUTHWEST FLOW ALOFT WILL CONTINUE TO INCREASE THROUGH THIS
EVENING AHEAD OF THE APPROACHING SYSTEM. SOME GUSTS OF 30 TO 40
MPH STILL POSSIBLE ACROSS THE EASTERN PLAINS AND PALMER DIVIDE.
THE GUSTY WINDS WILL DRIVE HUMIDITY INTO THE TEENS THIS AFTERNOON
WHICH WILL HELP TO ELEVATE THE FIRE DANGER IN AREAS THAT DID NOT
RECEIVE MUCH PRECIP FROM THE RECENT STORM. NO RED FLAG HILITES AT
THIS TIME. ACROSS MOUNTAINS...MID LEVEL MOISTURE INCREASES BY THE
EVENING...WITH LATEST RAP DELAYING THE STRONGER QG LIFT TILL
AFTER MIDNIGHT. OVERALL...CURRENT FORECASTS STILL ON TRACK...BUT
MAY NEED TO ADJUST TIMING OF THE GUSTY WINDS ACROSS THE PLAINS A
BIT EARLIER.
.AVIATION...SOUTHERLY WINDS HAVE MIXED TO THE SURFACE ACROSS THE
SOUTHERN DENVER AREA. WEAK DENVER CONVERGENCE BOUNDARY OVER DIA
HAS APPEARED TO SHIFT EAST WITH LIGHT NORTHWEST WINDS OCCURRING
THERE. SHOULD SEE GUSTY SOUTHERLY WINDS SPREAD ACROSS DIA BY 20Z
WHILE CONTINUING AT APA. IT NOW APPEARS THAT THE POTENTIAL FOR A
FEW GUSTS OF 30 KTS OR GREATER FOR DEN IS LOWER THAT EARLIER
THOUGHT...GIVEN THE CURRENT LOCATION OF THE BOUNDARY. BJC TO
REMAIN ON THE BACK SIDE OF THIS BOUNDARY. CURRENT TAF TRENDS STILL
SEEM ON TRACK...WITH POSSIBLE GUSTS AT DEN TO 22 KTS AT 20Z.
SHOWERS EXPECTED TO DEVELOP IN THE AREA SATURDAY AFTERNOON...
BECOMING LIKELY DURING THE EVENING. IT MAY INITIALLY BE
RAIN...BUT SHOULD CHANGE TO ALL SNOW LATE AFTER 21Z. AT THIS
TIME...IT LOOKS LIKE ANY ACCUMULATIONS IN THE DENVER AREA WILL BE
LIGHT.
&&
.PREV DISCUSSION... /ISSUED 438 AM MST FRI FEB 8 2013/
SHORT TERM...SOUTHWEST FLOW ALOFT WILL STRENGTHEN THROUGH THIS
EVENING AS LARGE UPPER LOW DROPS INTO THE DESERT SOUTHWEST. AN
EXPANDING CIRRUS SHIELD AHEAD OF THE UPPER TROUGH WILL QUICKLY
SPREAD ACROSS THE FORECAST AREA EARLY THIS MORNING. THIS WILL
LIKELY PROVIDE FOR A MOSTLY CLOUDY MORNING AS SUGGESTED BY
SYNTHETIC SATELLITE IMAGERY AS WELL. HOWEVER...BY AFTERNOON UPPER
LEVEL HUMIDITY DECREASES QUICKLY AS ANOTHER DRY SLOT MOVES IN
WHICH SHOULD BRING A RETURN OF MOSTLY SUNNY SKIES. EXCEPTION WOULD
BE IN THE HIGH COUNTRY WHERE SOME CONVECTIVE CLOUDINESS IS
POSSIBLE AS Q-G LIFT AND MID LEVEL MOISTURE BEGINS TO INCREASE.
ANY SHOWERS IN THE HIGH COUNTRY SHOULD HOLD OFF UNTIL THIS EVENING
WHEN BETTER MOISTURE...DESTABILIZATION...AND STRONGER Q-G LIFT
ARRIVE. MIGHT BE ABLE TO SNEAK OUT AN INCH OR SO OF SNOW OVERNIGHT
IN THE FAR WESTERN PORTIONS OF OUR FORECAST AREA...BUT SOUTHERLY
FLOW WILL KEEP OUR MOUNTAINS LARGELY BLOCKED FROM OROGRAPHIC
SNOWFALL THROUGH TONIGHT.
TEMPERATURES WILL BE ABOUT 10 DEGREES ABOVE NORMAL COUNTING ON
ENOUGH SUNSHINE THIS AFTERNOON. SOUTHERLY WINDS WILL ALSO INCREASE
WITH GUSTS OF 30-40 MPH OVER THE EASTERN PLAINS AND PALMER DIVIDE
AREA. FIRE DANGER WILL BE ELEVATED IN AREAS THAT DIDNT SEE SNOW
TWO NIGHTS AGO. HUMIDITY LEVELS SHOULD REMAIN JUST SHY OF RED FLAG
CONDITIONS.
LONG TERM...A RELATIVELY ACTIVE WEEK OF WEATHER APPEARS TO BE IN
STORE FOR THE FORECAST AREA...ALBEIT NOT AS ACTIVE AS NEW ENGLAND
OVER THE NEXT DAY OR SO. FOR COLORADO...A POTENT UPPER LEVEL LOW
WILL BE MOVING OVER THE STATE FROM MIDDAY SATURDAY THROUGH SUNDAY
MORNING. Q-G DIAGNOSTICS SHOWS THAT THERE WILL BE STRONG DYNAMIC
LIFT WITH THIS SYSTEM AND MODEL SOUNDINGS SHOW THE AIRMASS
BECOMING SLIGHTLY UNSTABLE BY SATURDAY AFTERNOON AND EVENING.
HOWEVER...ALL OF THE MODELS HAVE BEEN FAIRLY CONSISTENT IN
BRINGING THE CENTER OF THE UPPER CIRCULATION ACROSS THE NORTHERN
HALF OF COLORADO...RATHER THAN ALONG A MORE PREFERRED SOUTHERN
COLORADO TRACK. A NORTHERN TRACK WILL PUSH MOST OF THE
PRECIPITATION UP INTO WYOMING AND WESTERN NEBRASKA RATHER THAN
NORTHEASTERN COLORADO. DUE TO THE STRONG POSSIBILITY THAT THE
NORTHERN TRACK IS GOING TO PRODUCE A LOT OF DOWNSLOPE WESTERLIES
AT LOW LEVELS ALONG THE FRONT RANGE...THE FORECAST PRECIPITATION
AMOUNTS ARE LIGHT...IN SPITE OF BEING IN THE LIKELY CATEGORY. IF
THE SYSTEM EVOLVES WITH A MORE SOUTHERN TRACK...THEN LATER
FORECASTS WILL BEGIN TO REFLECT HEAVIER AMOUNTS OF PRECIPITATION
ON THE NORTHEAST COLORADO PLAINS. THE OTHER ELEMENT TO THE PASSING
STORM IS GOING TO BE STRONG PRESSURE GRADIENTS THAT DEVELOP OVER
THE NORTHEAST CORNER OF THE STATE. WITH LIGHT SNOW EXPECTED TO BE
FALLING...A FAIR AMOUNT OF BLOWING SNOW MAY RESULT. WHITEOUT
CONDITIONS MAY BE POSSIBLE SATURDAY NIGHT AND SUNDAY...DURING THE
PERIOD OF HIGHEST WINDS. WILL ISSUE A BLIZZARD WATCH FOR THE
NORTHEAST CORNER OF THE STATE TO HIGHLIGHT THIS POSSIBILITY.
IN THE MOUNTAINS...THE PASSING SYSTEM WILL PRODUCE SNOWFALL FROM
SATURDAY AFTERNOON THROUGH SUNDAY. THE PERIOD OF HEAVIEST SNOW
APPEARS TO BE SATURDAY AFTERNOON AND EVENING...BUT AMOUNTS DO NO
LOOK PARTICULARLY HEAVY. NO HIGHLIGHTS ARE EXPECTED AT THIS TIME.
OROGRAPHIC SNOW SHOWER ACTIVITY IS EXPECTED TO CONTINUE THE REST
OF THE WEEKEND AS ANOTHER WEATHER IMPULSE DROPS INTO THE REGION BY
SUNDAY NIGHT.
SOME SNOW SHOWERS MAY MOVE ONTO THE PLAINS SUNDAY NIGHT...BUT IT
IS DIFFICULT TO TELL HOW MUCH DOWNSLOPING WILL BE PRESENT TO
REDUCE SNOW SHOWER ACTIVITY. THE SECONDARY SYSTEM WILL HELP TO
REINFORCE THE COLD AIR THAT INITIALLY MOVES INTO THE STATE
SATURDAY AFTERNOON AND NIGHT. THIS WILL KEEP TEMPERATURES COLD
THROUGH THE START OF THE WEEK. AFTER DRY WEATHER AND GRADUAL
MODERATION IN TEMPERATURES THROUGH WEDNESDAY...THE GFS MODEL IS
NOW SHOWING ANOTHER UPPER TROUGH DIGGING ACROSS THE REGION FOR THE
END OF THE WEEK. THE ECMWF HAS A MUCH DIFFERENT SOLUTION...SO WE
WILL DEFER ANY DECISIONS ON THE END OF THE WEEK UNTIL LATER.
AVIATION...GUSTY SOUTHERLY WINDS SHOULD PREVAIL AT KDEN AND KAPA
THROUGH MOST OF THE DAY. GUSTS OF 25 KTS WILL LIKELY DEVELOP AS
AIRMASS MIXES THIS AFTERNOON BUT SEE POTENTIAL FOR A FEW 30+ KT
GUSTS IF DENVER CYCLONIC CONVERGENCE ZONE SHIFTS FAR ENOUGH
NORTHWARD. IF THIS ZONE SHIFTS SOUTHWARD...THEN THERE IS A CHANCE
THAT LIGHTER SOUTHWESTERLY WINDS WILL OCCUR AT KDEN AND KAPA BUT
THIS SCENARIO IS NOT ANTICIPATED AT THIS TIME. MEANWHILE...KBJC
SHOULD REMAIN FIRMLY ENTRENCHED ON THE BACK SIDE OF CONVERGENCE
ZONE SO LIGHTER WINDS AROUND 10KTS OR LESS SHOULD PREVAIL THERE.
VFR CONDITIONS WILL REMAIN IN PLACE THROUGH SATURDAY MORNING...
THEN SNOW SHOWERS LIKELY DEVELOPING IN THE AREA LATE SATURDAY
AFTERNOON AND EVENING. AT THIS TIME...ANY ACCUMULATION FOR THE
FRONT RANGE AIRPORTS IS EXPECTED TO BE LIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON
FOR COZ048-050-051.
&&
$$
SHORT TERM...D-L
LONG TERM....DANKERS
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1224 PM EST FRI FEB 8 2013
.SYNOPSIS...
A INTENSIFYING COASTAL STORM EAST OF DELMARVA WILL AFFECT OUR
AREA TODAY THROUGH TONIGHT, AS IT PASSES 150 MILES EAST OF ATLANTIC
CITY THIS EVENING...THEN MOVES TO NEAR NANTUCKET SATURDAY MORNING.
HIGH PRESSURE WILL BUILD INTO THE REGION SATURDAY NIGHT INTO
SUNDAY AS THE LOW CONTINUES TO MOVE INTO THE CANADIAN MARITIMES.
AN AREA OF LOW PRESSURE WILL TRACK THROUGH THE GREAT LAKES ON
MONDAY AND INTO EASTERN CANADA THROUGH TUESDAY, DRAGGING A COLD
FRONT ACROSS OUR AREA ON MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1115A: NEW GFS CHECKED AND IT CONCURS ON I78 NORTH MOSTLY SNOW IN
OUR AREA. THE WRAP AROUND IS STILL THERE BUT I THINK I`M GOING TO
TRIM AMTS 1-2 INCHES OVER MOST OF THE AREA...PENDING THE 3PM SNOW
DEPTHS AND RADAR PATTERN. LATEST RUC NOT SHOWING MUCH DRY SLOT ANY
MORE BUT CIRRUS SEEDING MAY QUIT FOR A FEW HRS LATE THIS AFTN BEFORE
THE WRAP AROUND TONIGHT. ITS GOING TO BE SLIPPERY TONIGHT OVER
MOST OF E PA AND N 3/4 OF NJ.
1030A: R/S LINE NOT BUDGING MUCH A SLIGHT NORTH
DRIFT TOWARD I78. HEAVIER PCPN MIXES AND CHANGES BRIEFLY TO SNOW
MIDDAY. IF THE PCPN LIGHTENS UP...IT SHOULD GO BACK TO RAIN ALONG
AND S OF I78.
I ADDED MORE SNOW TO THE WEATHER GRIDS TODAY AND A FASTER CHANGE
THIS EVENING BUT NO CHANGE IN ACCUMS SINCE TEMPS IN THE LOWER 30S
MIDDAY AND WHILE ACCUM ON GRASS AND CARS...LESS ON PAVEMENT. AN
SPS IS POSTED FOR THE CC R/S TRANSITION ZONE.
915: LOOKED AT 12Z NAM AND WHILE IT LOOKS MORE REALISTIC AM NOT
QUITE SURE HOW WE GET ALL THIS SNOW TONIGHT. NO BIG CHANGE IN THE
FCST AT 930AM. IT DOES LOOK LIKE THE REGION E OF RTE 206 IN NJ
WILL GET A PRETTY SUBSTANTIAL SNOW TODAY BUT FOR EVERYONE IN THE
ADVY/ WARNING THE MAIN EVENT IS TONIGHT...ESPECIALLY 0Z-6Z. I
THINK THE 12Z NAM IS STILL TOO WARM LOOKING AT ITS 12Z TSECTIONS
AND SEEING THE CC NOT MOVING NORTH YET FROM ABOUT 20 MI N OF I95.
815 AM UPDATE: NO SIG CHANGES ATTM.
12Z ANALYSIS SUGGESTS NAM BEST FIT ON PRES. ALL MODELS SIMILAR ON
6 HR QPF ENDING 12Z. HOWEVER THE MOST IMPORTANT...IT LOOKS LIKE
THE GFS IS IN LARGE ERROR ON ITS THERMAL PROFILE AND THAT THE 06Z
NAM AND 00Z ECMWF ARE MUCH MORE ACCURATE...I.E. COLDER. CC ON THE
821 AM RADAR SHOWS THE PHASE CHANGE VERY NICELY...FROM NEAR KUKT-
JUST N OF KTTN TO MIDWAY BETWEEN KLDJ AND KBLM. WE`VE SEEN 48-52 KT
GUSTS JUST EAST OF KORF AT 13Z.
SO FAR...NO SIGNIFICANT CHANGES TO THE WINTER WARNINGS OR ADVISORIES
IN PLACE. A WIND ADVISORY CONTINUES. WILL BE ADDED FOR PORTIONS OF
SOUTHEAST NEW JERSEY AND SOUTHERN DELAWARE FOR THIS AFTERNOON AND
TONIGHT. A COASTAL FLOOD WARNING CONTINUES.
FROM THE MID SHIFT BELOW...
FOR THE MOST PART...THIS FORECAST WAS BASED HEAVILY ON THE 0000
UTC ECMWF. THE 0000 UTC NAM LOOKS A BIT TOO STRONG AT THIS
LATITUDE... AND IS CONSIDERABLY FURTHER WEST THAT OTHER 0000 UTC
MODEL SOLUTIONS. THIS COULD BE DUE TO THE WARM BIAS SEEN ON THE
ANALYSIS...AND HOW THIS IS MANIFEST THROUGH THE DEVELOPMENT OF THE
SURFACE SYSTEM. ON THE OTHER HAND...THE 0000 UTC GFS LOOKS A BIT
TOO FAR EAST... CONSIDERING THAT THE MID LEVEL TROUGH GOES
NEGATIVE THIS AFTERNOON.
THE BOUNDARY LAYER HAS REMAINED FAIRLY WARM EARLY THIS MORNING...AS
THE FLOW HAS BEEN MORE EAST NORTHEAST THAN NORTHEAST. THIS IS
ALLOWING THE PRECIPITATION TO START AS RAIN AS FAR NORTHWEST AS
KPHL AND KTTN. FURTHER NORTH...THE COLUMN AND BOUNDARY LAYER
SHOULD REMAIN COLD ENOUGH FOR SNOW AS THE DOMINANT PRECIPITATION
TYPE IN THE MORNING. OUTSIDE OF THE TERRAIN...THE BOUNDARY LAYER
IN LIGHT PRECIPITATION RATES SHOULD ALLOW THE PRECIPITATION TO
CHANGE TO RAIN AT TIMES TODAY.
BASED ON THE 0000 UTC ECMWF...THE BEST PRECIPITATION RATES SHOULD BE
COINCIDENT WITH THE BEST MID LEVEL FRONTOGENETIC FORCING. THE BEST
BANDING POTENTIAL LIES WITH THE FORCING...AND THIS SHOULD ALSO OCCUR
IN THE 2100 UTC TO 0300 UTC TIMEFRAME FOR MOST PLACE. THE BEST LIFT
INITIALLY OCCURS CLOSER TO THE COAST...AND ACROSS SOUTHERN AREAS.
WITH PRECIPITABLE WATER VALUES REACHING CLOSE TO AN INCH (WHICH IS
TWO STANDARD DEVIATIONS ABOVE NORMAL FOR EARLY FEBRUARY)...HEAVY
RAIN IS POSSIBLE ACROSS CENTRAL AND SOUTHERN DELAWARE AND NEW
JERSEY. AT THIS POINT...IT DOES NOT LOOK LIKE THE FLASHIER AREAS
(NORTHERN DELAWARE...SOUTHEAST PENNSYLVANIA OR NORTH CENTRAL NEW
JERSEY) WILL GET THE HEAVIEST RAIN. FOR THIS REASON...WE PASSED ON A
FLOOD WATCH THIS MORNING.
AS THE PRESSURE GRADIENT INCREASES THIS AFTERNOON INTO THIS
EVENING...IT COULD SUPPORT MARGINAL WIND ADVISORY GUSTS FOR
SOUTHEAST NEW JERSEY AND SOUTHERN DELAWARE. MODEL SOUNDINGS SHOW
THAT 45 TO 50 KNOT WINDS REMAIN ABOVE THE LOWERING INVERSION.
HOWEVER...HEAVY RAIN COULD HELP THIS MOMENTUM GET THROUGH THE
INVERSION...RESULTING IN 50 MPH GUSTS. IT IS ALSO POSSIBLE THAT THE
STRONG PRESSURE FALLS COULD CREATE STRONGER THAN MODEL ISALLOBARIC
FLOW...WHICH TURN COULD RESULT IN STRONGER GUSTS. BASED ON THE
ABOVE...A WIND ADVISORY WAS BEEN ISSUED FOR THE ABOVE MENTIONED AREAS
FOR THIS AFTERNOON AND TONIGHT.
PERHAPS THE TRICKIEST PART OF THE FORECAST LATE THIS AFTERNOON AND
THIS EVENING IS THE RETURN OF THE COLDER AIR TO THE PHILADELPHIA
METRO AREA. AS THE LOW LEVEL CIRCULATION COMES ASTRIDE OF THE NEW
JERSEY COAST...THE NORTHERLY FLOW WILL ALLOW THE COLDER AIR TO FLOOD
THE BOUNDARY LAYER...RESULTING IN A PRECIPITATION PHASE CHANGE. RIGHT
NOW...DUE TO RAIN TODAY HAMPERING ACCUMULATIONS...WE HELD OFF ON
UPPING SNOWFALL AMOUNTS TODAY...AS IT IS STILL NOT CLEAR SHOW MUCH
ACCUMULATION WILL OCCUR BEFORE DUSK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
AS MENTIONED EARLIER...THE BEST MID LEVEL FORCING OCCURS ACROSS MUCH
OF THE AREA THROUGH ABOUT 0300 UTC. DURING THIS TIME...THE
PRECIPITATION PHASE CHANGE WILL BE OCCURRING. SINCE IT IS NOT CLEAR
HOW MUCH ACCUMULATION WILL OCCUR ON THE WET GROUND...WE WILL HOLD OF
ON UPGRADING SOUTHEAST PENNSYLVANIA (INCLUDING PHILADELPHIA) TO A
WINTER STORM WARNING.
THE BEST BANDING SHOULD OCCUR ACROSS CENTRAL AND EASTERN AREAS
DURING THE EVENING...RESULTING HEAVY RAIN CHANGING TO HEAVY SNOW.
FOR NOW...THE PREVIOUS FORECAST HAS A GOOD HANDLE ON THE FLAVOR OF
THE CHANGEOVER...AND MOSTLY TWEAKS WERE MADE TO THE SNOWFALL
FORECAST FOR CENTRAL AND SOUTHERN AREAS.
HOWEVER...AS THE CLOSED MID LEVEL SYSTEM CROSSES THE REGION LATE
THIS EVENING AND OVERNIGHT...THE MID LEVEL FRONTOGENETIC FORCING
INCREASES DRAMATICALLY ACROSS THE NORTHERN HALF OF THE AREA. THIS
SHOULD RESULT IN BANDING INTENSIFYING ACROSS THE NORTHERN LEHIGH
VALLEY...SOUTHERN POCONOS AND NORTHERN NEW JERSEY THIS EVENING.
BETWEEN 0000 AND 0600 UTC...AREAS THAT GET INTO THE BEST BANDING
COULD SEE 2 INCHES OF SNOW AN HOUR.
SINCE IT IS DIFFICULT TO PINPOINT THE PRECISE LOCATIONS OF THE
BANDS...THE OVERALL SNOWFALL FORECASTS WERE ONLY TWEAKED...AND WILL
UNDOUBTEDLY NEED TO BE ADJUSTED ONCE IT IS CLEAR WHERE THE BANDS SET
UP. WHILE THE PRESSURE GRADIENT INCREASES INTO THE EVENING
HOURS...THE COMBINATION OF VISIBILITY AND WIND GUSTS DOES NOT APPEAR
TO BE ENOUGH TO UPGRADE PORTIONS OF NORTHERN NEW JERSEY TO A
BLIZZARD WARNING THIS MORNING.
IN ADDITION...SLANTWISE CONVECTION IS POSSIBLE AS LOWER PVU AIR
COMES IN OVER THE MOISTURE IN PLACE. THE SLANTWISE CONVECTION MAY BE
ENOUGH TO PRODUCE CHARGE SEPARATION AND LIGHTNING. HOWEVER...IT IS
NOT CLEAR WHETHER THE COVERAGE OF LIGHTNING WILL BE ENOUGH TO
INCLUDE IN THE FORECAST...AND IT WILL BE OMITTED FOR NOW,.
AGAIN...THE TRICKIEST PART OF THE FORECAST WILL BE HOW QUICKLY THE
SNOW ACCUMULATES ACROSS PORTIONS OF SOUTHEAST PENNSYLVANIA AND
NEARBY NEW JERSEY AFTER THE CHANGEOVER. BANDING HERE WOULD HELP WITH
ACCUMULATIONS...BUT THIS IS NOT YET SUPPORTED BY NEAR OR SHORT TERM
MODELS.
AS THE CLOSED MID LEVEL SYSTEM MOVES EAST...THE PRECIPITATION SHOULD
TAPER OFF AFTER 0600 UTC SATURDAY. THE EXCEPTION COULD BE COASTAL
NEW JERSEY. THE WOBBLING MID LEVEL SYSTEM COULD ALLOW BANDS TO
REMAIN NEAR THE OCEAN AND MONMOUTH COUNTY COASTS INTO SATURDAY
MORNING.
THE BEST PRESSURE GRADIENT SHOULD BE OFFSHORE BY 0600 UTC
SATURDAY...BUT THE ADVISORY WAS EXTENDED THROUGH 0900 UTC TO ALLOW
ALL AREAS TO DROP BELOW 40 MPH IN GUSTS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
BY SATURDAY MORNING, THE COASTAL STORM SHOULD BE NEAR CAPE COD AND
CONTINUING TO MOVE TO THE NORTHEAST. GUIDANCE CONTINUES TO SHOW MOST
IF NOT ALL OF THE PRECIPITATION BEING OUT OF OUR AREA DURING THE
MORNING HOURS AFTER SUNRISE SATURDAY, SO WE HAVE BACKED OUR
PRECIPITATION CHANCES THROUGH THE MORNING HOURS SATURDAY. OUR MAIN
CONCERN SATURDAY WILL BE THE STRONG WINDS BEHIND THE STORM AS HIGH
PRESSURE TRIES TO BUILD IN BEHIND THE STORM INCREASING THE PRESSURE
GRADIENT ACROSS THE AREA. WINDS WITHIN THE LOWEST 2,000-3,000 FEET
DIFFER BETWEEN THE GFS AND NAM; THE GFS SHOWS 30-35 KNOTS WHILE THE
NAM SHOWS 40-45 KNOTS. THE NAM WOULD INDICATE MUCH STRONGER WIND
GUSTS DURING THE DAY, BUT FOR NOW WE EXPECT WIDESPREAD 30-40 MPH
GUSTS WITH SOME HIGHER AMOUNTS POSSIBLE. WE DECIDED TO GO A FEW
DEGREES BELOW GFS MOS GUIDANCE FOR HIGHS SATURDAY AS TEMPERATURES
MAY NOT RISE SIGNIFICANTLY IF WE HAVE A GOOD SNOW PACK FOR MUCH OF
THE AREA.
HIGH PRESSURE FINALLY BUILDS ACROSS THE AREA SATURDAY NIGHT INTO
SUNDAY WHICH WILL ALLOW THE WINDS TO BEGIN TO RELAX SATURDAY NIGHT.
WITH HIGH PRESSURE AT THE SURFACE AND RIDGING ALOFT, DRY WEATHER IS
EXPECTED THROUGH SUNDAY.
THEN THE FOCUS TURNS TO AN AREA OF LOW PRESSURE THAT WILL BE MOVING
THROUGH THE GREAT LAKES REGION MONDAY AND INTO EASTERN CANADA MONDAY
NIGHT INTO TUESDAY. THE SYSTEM IS EXPECTED TO DRAG A COLD FRONT
ACROSS OUR AREA MONDAY INTO MONDAY NIGHT WITH WARMING TEMPERATURES
AND MORE PRECIPITATION. A WARM FRONT COULD BE LIFTING ACROSS THE AREA
LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING WHICH COULD HAVE SOME
LIGHT OVERRUNNING PRECIPITATION. IF THE PRECIP STARTS EARLY ENOUGH
WHILE TEMPERATURES ARE COLD ENOUGH, WE COULD HAVE A MIXTURE OF
SNOW/SLEET/FREEZING RAIN FOR A PORTION OF THE AREA. HOWEVER, AS THE
WARM FRONT LIFTS NORTHWARD, WARM AIR IS EXPECTED TO SURGE NORTHWARD,
CHANGING MOSTLY EVERYONE OVER TO RAIN THROUGH THE DAY. ONCE THE
FRONT MOVES THROUGH THE AREA, PRECIPITATION SHOULD END ACROSS THE
AREA.
WITH NEARLY ZONAL FLOW ALOFT ACROSS THE AREA TUESDAY, TEMPERATURES
ARE NOT EXPECTED TO INCREASE ACROSS THE AREA FROM MONDAY, REMAINING
ABOVE NORMAL. MOST OF THE AREA SHOULD REMAIN DRY FOR TUESDAY INTO
TUESDAY NIGHT.
ANOTHER COASTAL LOW IS FORECAST TO DEVELOP ALONG THE COLD FRONT TO
OUR SOUTH BY WEDNESDAY, BUT FOR NOW THE GFS/ECMWF KEEP THE SYSTEM TO
OUR SOUTH. THE GFS DOES BRING UP SOME PRECIPITATION ACROSS SOME OF
OUR AREA, WHILE THE ECMWF KEEPS IT SOUTH. WE WILL KEEP WITH THE
PREVIOUS FORECAST AND A CHANCE OF PRECIPITATION FOR NOW ACROSS THE
AREA DUE TO THE UNCERTAINTY AND WAIT TO SEE WHAT LATER GUIDANCE
BRINGS US.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TODAY...LOWERING TO IFR IN RAIN I95 SEWD AND R/SNOW MIX KRDG AND
POSSIBLY KTTN AND PROBABLY MOSTLY SNOW AT KABE WITH THE BL TEMP
CONTROLLING PHASE DURING THE MIDDAY HOURS. NE WIND A FEW G20-30 KT
TODAY I95 SEWD AND 10 TO 15 KTS KRDG AND KABE. WIND TURNS N AND
GUSTS 20-30 KT LATE THIS AFTN/EVE WITH COLDER AIR ARRIVING AND
PCPN CHANGING TO ALL SNOW FROM NW TO SE. EXACTLY WHEN...NOT SURE
AND NOT EVEN SURE WHAT THE RADAR WILL LO0OK LIKE AT THE TIME OF
THE CHANGE BUT BETWEEN 21Z AND 00Z LOOKS TO BE THE BEST ESTIMATE
FOR THE CHANGE FM RAIN TO SNOW EXCEPT 02Z- 03Z KMIV AND KACY.
TONIGHT...LIFR CONDITIONS ARE EXPECTED THIS EVENING...AS RAIN
CHANGES TO SNOW FROM KPHL SOUTH AND EAST...AND SNOW CONTINUES
NORTH AND WEST. NORTH WINDS WILL GUST BETWEEN 25 AND 35
KNOTS...ESPECIALLY FROM KPHL SOUTH AND EAST. THE HEAVIEST
PRECIPITATION WILL FALL BETWEEN 0000 UTC AND 0600 UTC. AFTER 0600
UTC...CONDITIONS COULD SLOWLY IMPROVE THROUGH IFR AS WINDS SHIFT
TO THE NORTHWEST.
OUTLOOK...
SATURDAY-SATURDAY NIGHT...MVFR CONDITIONS POSSIBLE EARLY, THEN IMPROVING
TO VFR. GUSTY NORTHWEST WINDS THROUGH THE DAY, WITH GUSTS 25 TO 30
KNOTS, DECREASING BY SATURDAY NIGHT.
SUNDAY...VFR.
SUNDAY NIGHT...MOSTLY VFR...MVFR AND/OR IFR CIGS/VSBYS POSSIBLE VERY
LATE.
MONDAY...MVFR AND/OR IFR CIGS/VSBYS WITH AREAS OF RAIN...POSSIBLE
WINTRY MIX EARLY NORTH.
MONDAY NIGHT...IMPROVING TO VFR OVERNIGHT.
TUESDAY...MOSTLY VFR. GUSTY AFTERNOON WINDS 20-25 KNOTS.
&&
.MARINE...
CONFIDENCE IN STORM WARNING VERIFICATION IS LESS THAN AVERAGE BUT
WE CONTINUE THE HEADLINE TIL THIS RAPIDLY DEEPENING SFC LO E OF
THE VA CAPES PASSES WELL E OF NJK TONIGHT.
NO CHANGES TO THE MARINE HEADLINES EARLY THIS MORNING. THE 0000 UTC
NAM LOOKS TOO FAR WEST WITH ITS TRACK...AND THE 0000 UTC GFS IS A
BIT TOO FAR EAST. THE 0000 UTC ECMWF IS A COMPROMISE TRACK...AND ITS
OUTPUT HAS BEEN USED EXTENSIVELY FOR THIS FORECAST.
THE GRADIENT BETWEEN THE DEVELOPING SURFACE LOW OFF THE NORTH
CAROLINA COAST AND HIGH PRESSURE OFF THE NEW ENGLAND COAST IS
TIGHTENING TO SUPPORT SMALL CRAFT WINDS. A GRADUAL RAMP UP OF THE
GRADIENT CONTINUES INTO THE EARLY AFTERNOON.
BY EARLY TO MID AFTERNOON...THE GRADIENT SUPPORTS GALE FORCE WIND
GUSTS...ESPECIALLY OVER THE OCEAN WATERS. THE BEST GRADIENT APPEARS
TO OCCUR BETWEEN 2100 UTC AND 0300 UTC. AT THE SAME TIME...925 MB
WINDS INCREASE TO 45 TO 50 KNOTS OVER THE OCEAN WATERS. MODEL
SOUNDINGS OVER THE OCEAN WATERS SUGGEST THAT THE 50 KNOTS OF
MOMENTUM REMAINS JUST ABOVE THE TOP OF THE SUPPRESSED INVERSION.
HOWEVER...HEAVY RAIN COULD BRING SOME OF THIS MOMENTUM DOWN...
SUPPORTING GUSTS TO 50 KNOTS. WHILE THE GRADIENT...ESPECIALLY FROM
NON-NAM MODELS...DOES NOT APPEAR TO SUPPORT STORM FORCE GUSTS...THE
STORM WARNING REMAINS IN PLACE TO COVER GUSTS IN HEAVY RAIN ON THE
OCEAN. SEAS SHOULD JUMP QUICKLY THIS AFTERNOON AS THE EAST NORTHEAST
FETCH RAMPS UP...AND FOR THE MOST PART A COUPLE OF FEET WAS ADDED TO
THE WAVEWATCH MODEL OUTPUT FOR THIS AFTERNOON AND TONIGHT.
OVER DELAWARE BAY...THE GRADIENT IS NOT AS TIGHTEN...ESPECIALLY WITH
THE NON-NAM MODEL TRACKS. AS WITH THE OCEAN...THE BEST GRADIENT
FALLS IN THE 2100 TO 0300 UTC WINDOW...AND THIS IS THE BEST SHOT AT
STRONG GALE FORCE WINDS...ESPECIALLY IN THE MOUTH OF THE BAY. AS THE
SURFACE LOW PULLS ASTRIDE OF THE NEW JERSEY COAST...WINDS BACK TO
THE NORTHWEST AFTER 0600 UTC...AND GALE FORCE GUSTS ARE EXPECTED ON
ALL WATERS.
OUTLOOK...
GUSTY WINDS ACROSS THE WATERS WILL CONTINUE THROUGH SATURDAY INTO
SATURDAY EVENING. THE STORM WARNING ACROSS THE ATLANTIC COASTAL
WATERS WILL LIKELY BE REPLACED BY A GALE WARNING BY SATURDAY. WINDS
WILL CONTINUE TO DIMINISH INTO SATURDAY NIGHT, THROUGH SMALL CRAFT
ADVISORY CONDITIONS WILL LIKELY REMAIN. HOWEVER, AS HIGH PRESSURE
CONTINUES TO BUILD ACROSS THE AREA INTO SUNDAY WINDS WILL FINALLY
DROP BELOW ADVISORY LEVELS AND REMAIN SO THROUGH SUNDAY NIGHT.
HOWEVER, WINDS SHOULD RETURN TO SMALL CRAFT ADVISORY LEVELS MONDAY
AND MONDAY NIGHT AS A COLD FRONT MOVES THROUGH THE AREA; WINDS COULD
APPROACH GALE FORCE AGAIN. WINDS SHOULD DROP BACK BELOW ADVISORY
LEVELS TUESDAY AS THE PRESSURE GRADIENT SLACKENS SOME.
&&
.TIDES/COASTAL FLOODING...
A COASTAL FLOOD WARNING HAS NOW BEEN ISSUED FOR THE ATLANTIC
SEABOARD AS WELL AS THE LOWER DELAWARE BAY COVERING BOTH THIS
EVENING`S HIGH TIDE AS WELL AS SATURDAY MORNING`S. THE ASTRONOMICAL
FORECAST FOR THE HIGH TIDE THIS EVENING IS LOWER THAN SATURDAY
MORNING`S WHICH MAY KEEP THIS EVENING`S HIGH TIDE IN THE UPPER END
OF MINOR. HOWEVER, GUIDANCE CONTINUES TO INDICATE THAT SATURDAY
MORNING`S WILL REACH MODERATE. WE MAY EVEN APPROACH SEVERE COASTAL
FLOOD LEVELS FROM ATLANTIC CITY NORTHWARD SATURDAY MORNING.
THE UPPER PORTIONS OF THE DELAWARE BAY AND TIDAL DELAWARE RIVER DO
NOT LOOK LIKE THEY WILL REACH MINOR FLOOD LEVELS THIS EVENING, BUT
THE SATURDAY MORNING HIGH TIDE MAY GET TO MINOR.
WE ARE NOT EXPECTING COASTAL FLOODING ALONG THE EASTERN SHORE OF THE
CHESAPEAKE BAY AT THIS TIME
&&
.EQUIPMENT..
DIX 88D TEMPO OTS. LOST POWER AT THE SITE. TECH ON HIS WAY. RTS
UNKNOWN.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WARNING UNTIL 6 AM EST SATURDAY FOR PAZ054-055-
061-062.
WINTER STORM WARNING UNTIL 6 AM EST SATURDAY FOR PAZ060-101-
103>106.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 6 AM EST
SATURDAY FOR PAZ070-071-102.
NJ...WINTER STORM WARNING UNTIL 6 AM EST SATURDAY FOR NJZ001-007-
008.
WINTER STORM WARNING UNTIL 6 AM EST SATURDAY FOR NJZ009-010-
012>015-019-020-026.
COASTAL FLOOD WARNING FROM 4 PM THIS AFTERNOON TO 11 AM EST
SATURDAY FOR NJZ012>014-020>027.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 6 AM EST
SATURDAY FOR NJZ016>018-021>025-027.
WIND ADVISORY UNTIL 5 AM EST SATURDAY FOR NJZ022>025-027.
DE...COASTAL FLOOD WARNING FROM 4 PM THIS AFTERNOON TO 11 AM EST
SATURDAY FOR DEZ002>004.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 6 AM EST
SATURDAY FOR DEZ001.
WIND ADVISORY UNTIL 5 AM EST SATURDAY FOR DEZ003-004.
MD...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 6 AM EST
SATURDAY FOR MDZ008.
MARINE...STORM WARNING UNTIL 6 AM EST SATURDAY FOR ANZ450>455.
GALE WARNING UNTIL 6 PM EST SATURDAY FOR ANZ430-431.
&&
$$
SYNOPSIS...DRAG/ROBERTSON
NEAR TERM...DRAG/HAYES
SHORT TERM...HAYES
LONG TERM...ROBERTSON
AVIATION...DRAG/HAYES/ROBERTSON
MARINE...DRAG/HAYES/ROBERTSON
TIDES/COASTAL FLOODING...
EQUIPMENT...DRAG 1224
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1119 AM EST FRI FEB 8 2013
.SYNOPSIS...
A INTENSIFYING COASTAL STORM EAST OF DELMARVA WILL AFFECT OUR
AREA TODAY THROUGH TONIGHT, AS IT PASSES 150 MILES EAST OF ATLANTIC
CITY THIS EVENING...THEN MOVES TO NEAR NANTUCKET SATURDAY MORNING.
HIGH PRESSURE WILL BUILD INTO THE REGION SATURDAY NIGHT INTO
SUNDAY AS THE LOW CONTINUES TO MOVE INTO THE CANADIAN MARITIMES.
AN AREA OF LOW PRESSURE WILL TRACK THROUGH THE GREAT LAKES ON
MONDAY AND INTO EASTERN CANADA THROUGH TUESDAY, DRAGGING A COLD
FRONT ACROSS OUR AREA ON MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1115A: NEW GFS CHECKED AND IT CONCURS ON I78 NORTH MOSTLY SNOW IN
OUR AREA. THE WRAP AROUND IS STILL THERE BUT I THINK I`M GOING TO
TRIM AMTS 1-2 INCHES OVER MOST OF THE AREA...PENDING THE 3PM SNOW
DEPTHS AND RADAR PATTERN. LATEST RUC NOT SHOWING MUCH DRY SLOT ANY
MORE BUT CIRRUS SEEDING MAY QUIT FOR A FEW HRS LATE THIS AFTN BEFORE
THE WRAP AROUND TONIGHT. ITS GOING TO BE SLIPPERY TONIGHT OVER
MOST OF E PA AND N 3/4 OF NJ.
1030A: R/S LINE NOT BUDGING MUCH A SLIGHT NORTH
DRIFT TOWARD I78. HEAVIER PCPN MIXES AND CHANGES BRIEFLY TO SNOW
MIDDAY. IF THE PCPN LIGHTENS UP...IT SHOULD GO BACK TO RAIN ALONG
AND S OF I78.
I ADDED MORE SNOW TO THE WEATHER GRIDS TODAY AND A FASTER CHANGE
THIS EVENING BUT NO CHANGE IN ACCUMS SINCE TEMPS IN THE LOWER 30S
MIDDAY AND WHILE ACCUM ON GRASS AND CARS...LESS ON PAVEMENT. AN
SPS IS POSTED FOR THE CC R/S TRANSITION ZONE.
915: LOOKED AT 12Z NAM AND WHILE IT LOOKS MORE REALISTIC AM NOT
QUITE SURE HOW WE GET ALL THIS SNOW TONIGHT. NO BIG CHANGE IN THE
FCST AT 930AM. IT DOES LOOK LIKE THE REGION E OF RTE 206 IN NJ
WILL GET A PRETTY SUBSTANTIAL SNOW TODAY BUT FOR EVERYONE IN THE
ADVY/ WARNING THE MAIN EVENT IS TONIGHT...ESPECIALLY 0Z-6Z. I
THINK THE 12Z NAM IS STILL TOO WARM LOOKING AT ITS 12Z TSECTIONS
AND SEEING THE CC NOT MOVING NORTH YET FROM ABOUT 20 MI N OF I95.
815 AM UPDATE: NO SIG CHANGES ATTM.
12Z ANALYSIS SUGGESTS NAM BEST FIT ON PRES. ALL MODELS SIMILAR ON
6 HR QPF ENDING 12Z. HOWEVER THE MOST IMPORTANT...IT LOOKS LIKE
THE GFS IS IN LARGE ERROR ON ITS THERMAL PROFILE AND THAT THE 06Z
NAM AND 00Z ECMWF ARE MUCH MORE ACCURATE...I.E. COLDER. CC ON THE
821 AM RADAR SHOWS THE PHASE CHANGE VERY NICELY...FROM NEAR KUKT-
JUST N OF KTTN TO MIDWAY BETWEEN KLDJ AND KBLM. WE`VE SEEN 48-52 KT
GUSTS JUST EAST OF KORF AT 13Z.
SO FAR...NO SIGNIFICANT CHANGES TO THE WINTER WARNINGS OR ADVISORIES
IN PLACE. A WIND ADVISORY CONTINUES. WILL BE ADDED FOR PORTIONS OF
SOUTHEAST NEW JERSEY AND SOUTHERN DELAWARE FOR THIS AFTERNOON AND
TONIGHT. A COASTAL FLOOD WARNING CONTINUES.
FROM THE MID SHIFT BELOW...
FOR THE MOST PART...THIS FORECAST WAS BASED HEAVILY ON THE 0000
UTC ECMWF. THE 0000 UTC NAM LOOKS A BIT TOO STRONG AT THIS
LATITUDE... AND IS CONSIDERABLY FURTHER WEST THAT OTHER 0000 UTC
MODEL SOLUTIONS. THIS COULD BE DUE TO THE WARM BIAS SEEN ON THE
ANALYSIS...AND HOW THIS IS MANIFEST THROUGH THE DEVELOPMENT OF THE
SURFACE SYSTEM. ON THE OTHER HAND...THE 0000 UTC GFS LOOKS A BIT
TOO FAR EAST... CONSIDERING THAT THE MID LEVEL TROUGH GOES
NEGATIVE THIS AFTERNOON.
THE BOUNDARY LAYER HAS REMAINED FAIRLY WARM EARLY THIS MORNING...AS
THE FLOW HAS BEEN MORE EAST NORTHEAST THAN NORTHEAST. THIS IS
ALLOWING THE PRECIPITATION TO START AS RAIN AS FAR NORTHWEST AS
KPHL AND KTTN. FURTHER NORTH...THE COLUMN AND BOUNDARY LAYER
SHOULD REMAIN COLD ENOUGH FOR SNOW AS THE DOMINANT PRECIPITATION
TYPE IN THE MORNING. OUTSIDE OF THE TERRAIN...THE BOUNDARY LAYER
IN LIGHT PRECIPITATION RATES SHOULD ALLOW THE PRECIPITATION TO
CHANGE TO RAIN AT TIMES TODAY.
BASED ON THE 0000 UTC ECMWF...THE BEST PRECIPITATION RATES SHOULD BE
COINCIDENT WITH THE BEST MID LEVEL FRONTOGENETIC FORCING. THE BEST
BANDING POTENTIAL LIES WITH THE FORCING...AND THIS SHOULD ALSO OCCUR
IN THE 2100 UTC TO 0300 UTC TIMEFRAME FOR MOST PLACE. THE BEST LIFT
INITIALLY OCCURS CLOSER TO THE COAST...AND ACROSS SOUTHERN AREAS.
WITH PRECIPITABLE WATER VALUES REACHING CLOSE TO AN INCH (WHICH IS
TWO STANDARD DEVIATIONS ABOVE NORMAL FOR EARLY FEBRUARY)...HEAVY
RAIN IS POSSIBLE ACROSS CENTRAL AND SOUTHERN DELAWARE AND NEW
JERSEY. AT THIS POINT...IT DOES NOT LOOK LIKE THE FLASHIER AREAS
(NORTHERN DELAWARE...SOUTHEAST PENNSYLVANIA OR NORTH CENTRAL NEW
JERSEY) WILL GET THE HEAVIEST RAIN. FOR THIS REASON...WE PASSED ON A
FLOOD WATCH THIS MORNING.
AS THE PRESSURE GRADIENT INCREASES THIS AFTERNOON INTO THIS
EVENING...IT COULD SUPPORT MARGINAL WIND ADVISORY GUSTS FOR
SOUTHEAST NEW JERSEY AND SOUTHERN DELAWARE. MODEL SOUNDINGS SHOW
THAT 45 TO 50 KNOT WINDS REMAIN ABOVE THE LOWERING INVERSION.
HOWEVER...HEAVY RAIN COULD HELP THIS MOMENTUM GET THROUGH THE
INVERSION...RESULTING IN 50 MPH GUSTS. IT IS ALSO POSSIBLE THAT THE
STRONG PRESSURE FALLS COULD CREATE STRONGER THAN MODEL ISALLOBARIC
FLOW...WHICH TURN COULD RESULT IN STRONGER GUSTS. BASED ON THE
ABOVE...A WIND ADVISORY WAS BEEN ISSUED FOR THE ABOVE MENTIONED AREAS
FOR THIS AFTERNOON AND TONIGHT.
PERHAPS THE TRICKIEST PART OF THE FORECAST LATE THIS AFTERNOON AND
THIS EVENING IS THE RETURN OF THE COLDER AIR TO THE PHILADELPHIA
METRO AREA. AS THE LOW LEVEL CIRCULATION COMES ASTRIDE OF THE NEW
JERSEY COAST...THE NORTHERLY FLOW WILL ALLOW THE COLDER AIR TO FLOOD
THE BOUNDARY LAYER...RESULTING IN A PRECIPITATION PHASE CHANGE. RIGHT
NOW...DUE TO RAIN TODAY HAMPERING ACCUMULATIONS...WE HELD OFF ON
UPPING SNOWFALL AMOUNTS TODAY...AS IT IS STILL NOT CLEAR SHOW MUCH
ACCUMULATION WILL OCCUR BEFORE DUSK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
AS MENTIONED EARLIER...THE BEST MID LEVEL FORCING OCCURS ACROSS MUCH
OF THE AREA THROUGH ABOUT 0300 UTC. DURING THIS TIME...THE
PRECIPITATION PHASE CHANGE WILL BE OCCURRING. SINCE IT IS NOT CLEAR
HOW MUCH ACCUMULATION WILL OCCUR ON THE WET GROUND...WE WILL HOLD OF
ON UPGRADING SOUTHEAST PENNSYLVANIA (INCLUDING PHILADELPHIA) TO A
WINTER STORM WARNING.
THE BEST BANDING SHOULD OCCUR ACROSS CENTRAL AND EASTERN AREAS
DURING THE EVENING...RESULTING HEAVY RAIN CHANGING TO HEAVY SNOW.
FOR NOW...THE PREVIOUS FORECAST HAS A GOOD HANDLE ON THE FLAVOR OF
THE CHANGEOVER...AND MOSTLY TWEAKS WERE MADE TO THE SNOWFALL
FORECAST FOR CENTRAL AND SOUTHERN AREAS.
HOWEVER...AS THE CLOSED MID LEVEL SYSTEM CROSSES THE REGION LATE
THIS EVENING AND OVERNIGHT...THE MID LEVEL FRONTOGENETIC FORCING
INCREASES DRAMATICALLY ACROSS THE NORTHERN HALF OF THE AREA. THIS
SHOULD RESULT IN BANDING INTENSIFYING ACROSS THE NORTHERN LEHIGH
VALLEY...SOUTHERN POCONOS AND NORTHERN NEW JERSEY THIS EVENING.
BETWEEN 0000 AND 0600 UTC...AREAS THAT GET INTO THE BEST BANDING
COULD SEE 2 INCHES OF SNOW AN HOUR.
SINCE IT IS DIFFICULT TO PINPOINT THE PRECISE LOCATIONS OF THE
BANDS...THE OVERALL SNOWFALL FORECASTS WERE ONLY TWEAKED...AND WILL
UNDOUBTEDLY NEED TO BE ADJUSTED ONCE IT IS CLEAR WHERE THE BANDS SET
UP. WHILE THE PRESSURE GRADIENT INCREASES INTO THE EVENING
HOURS...THE COMBINATION OF VISIBILITY AND WIND GUSTS DOES NOT APPEAR
TO BE ENOUGH TO UPGRADE PORTIONS OF NORTHERN NEW JERSEY TO A
BLIZZARD WARNING THIS MORNING.
IN ADDITION...SLANTWISE CONVECTION IS POSSIBLE AS LOWER PVU AIR
COMES IN OVER THE MOISTURE IN PLACE. THE SLANTWISE CONVECTION MAY BE
ENOUGH TO PRODUCE CHARGE SEPARATION AND LIGHTNING. HOWEVER...IT IS
NOT CLEAR WHETHER THE COVERAGE OF LIGHTNING WILL BE ENOUGH TO
INCLUDE IN THE FORECAST...AND IT WILL BE OMITTED FOR NOW,.
AGAIN...THE TRICKIEST PART OF THE FORECAST WILL BE HOW QUICKLY THE
SNOW ACCUMULATES ACROSS PORTIONS OF SOUTHEAST PENNSYLVANIA AND
NEARBY NEW JERSEY AFTER THE CHANGEOVER. BANDING HERE WOULD HELP WITH
ACCUMULATIONS...BUT THIS IS NOT YET SUPPORTED BY NEAR OR SHORT TERM
MODELS.
AS THE CLOSED MID LEVEL SYSTEM MOVES EAST...THE PRECIPITATION SHOULD
TAPER OFF AFTER 0600 UTC SATURDAY. THE EXCEPTION COULD BE COASTAL
NEW JERSEY. THE WOBBLING MID LEVEL SYSTEM COULD ALLOW BANDS TO
REMAIN NEAR THE OCEAN AND MONMOUTH COUNTY COASTS INTO SATURDAY
MORNING.
THE BEST PRESSURE GRADIENT SHOULD BE OFFSHORE BY 0600 UTC
SATURDAY...BUT THE ADVISORY WAS EXTENDED THROUGH 0900 UTC TO ALLOW
ALL AREAS TO DROP BELOW 40 MPH IN GUSTS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
BY SATURDAY MORNING, THE COASTAL STORM SHOULD BE NEAR CAPE COD AND
CONTINUING TO MOVE TO THE NORTHEAST. GUIDANCE CONTINUES TO SHOW MOST
IF NOT ALL OF THE PRECIPITATION BEING OUT OF OUR AREA DURING THE
MORNING HOURS AFTER SUNRISE SATURDAY, SO WE HAVE BACKED OUR
PRECIPITATION CHANCES THROUGH THE MORNING HOURS SATURDAY. OUR MAIN
CONCERN SATURDAY WILL BE THE STRONG WINDS BEHIND THE STORM AS HIGH
PRESSURE TRIES TO BUILD IN BEHIND THE STORM INCREASING THE PRESSURE
GRADIENT ACROSS THE AREA. WINDS WITHIN THE LOWEST 2,000-3,000 FEET
DIFFER BETWEEN THE GFS AND NAM; THE GFS SHOWS 30-35 KNOTS WHILE THE
NAM SHOWS 40-45 KNOTS. THE NAM WOULD INDICATE MUCH STRONGER WIND
GUSTS DURING THE DAY, BUT FOR NOW WE EXPECT WIDESPREAD 30-40 MPH
GUSTS WITH SOME HIGHER AMOUNTS POSSIBLE. WE DECIDED TO GO A FEW
DEGREES BELOW GFS MOS GUIDANCE FOR HIGHS SATURDAY AS TEMPERATURES
MAY NOT RISE SIGNIFICANTLY IF WE HAVE A GOOD SNOW PACK FOR MUCH OF
THE AREA.
HIGH PRESSURE FINALLY BUILDS ACROSS THE AREA SATURDAY NIGHT INTO
SUNDAY WHICH WILL ALLOW THE WINDS TO BEGIN TO RELAX SATURDAY NIGHT.
WITH HIGH PRESSURE AT THE SURFACE AND RIDGING ALOFT, DRY WEATHER IS
EXPECTED THROUGH SUNDAY.
THEN THE FOCUS TURNS TO AN AREA OF LOW PRESSURE THAT WILL BE MOVING
THROUGH THE GREAT LAKES REGION MONDAY AND INTO EASTERN CANADA MONDAY
NIGHT INTO TUESDAY. THE SYSTEM IS EXPECTED TO DRAG A COLD FRONT
ACROSS OUR AREA MONDAY INTO MONDAY NIGHT WITH WARMING TEMPERATURES
AND MORE PRECIPITATION. A WARM FRONT COULD BE LIFTING ACROSS THE AREA
LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING WHICH COULD HAVE SOME
LIGHT OVERRUNNING PRECIPITATION. IF THE PRECIP STARTS EARLY ENOUGH
WHILE TEMPERATURES ARE COLD ENOUGH, WE COULD HAVE A MIXTURE OF
SNOW/SLEET/FREEZING RAIN FOR A PORTION OF THE AREA. HOWEVER, AS THE
WARM FRONT LIFTS NORTHWARD, WARM AIR IS EXPECTED TO SURGE NORTHWARD,
CHANGING MOSTLY EVERYONE OVER TO RAIN THROUGH THE DAY. ONCE THE
FRONT MOVES THROUGH THE AREA, PRECIPITATION SHOULD END ACROSS THE
AREA.
WITH NEARLY ZONAL FLOW ALOFT ACROSS THE AREA TUESDAY, TEMPERATURES
ARE NOT EXPECTED TO INCREASE ACROSS THE AREA FROM MONDAY, REMAINING
ABOVE NORMAL. MOST OF THE AREA SHOULD REMAIN DRY FOR TUESDAY INTO
TUESDAY NIGHT.
ANOTHER COASTAL LOW IS FORECAST TO DEVELOP ALONG THE COLD FRONT TO
OUR SOUTH BY WEDNESDAY, BUT FOR NOW THE GFS/ECMWF KEEP THE SYSTEM TO
OUR SOUTH. THE GFS DOES BRING UP SOME PRECIPITATION ACROSS SOME OF
OUR AREA, WHILE THE ECMWF KEEPS IT SOUTH. WE WILL KEEP WITH THE
PREVIOUS FORECAST AND A CHANCE OF PRECIPITATION FOR NOW ACROSS THE
AREA DUE TO THE UNCERTAINTY AND WAIT TO SEE WHAT LATER GUIDANCE
BRINGS US.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TODAY...LOWERING TO IFR IN RAIN I95 SEWD AND R/SNOW MIX KRDG AND
POSSIBLY KTTN AND PROBABLY MOSTLY SNOW AT KABE WITH THE BL TEMP
CONTROLLING PHASE DURING THE MIDDAY HOURS. NE WIND A FEW G20-30 KT
TODAY I95 SEWD AND 10 TO 15 KTS KRDG AND KABE. WIND TURNS N AND
GUSTS 20-30 KT LATE THIS AFTN/EVE WITH COLDER AIR ARRIVING AND
PCPN CHANGING TO ALL SNOW FROM NW TO SE. EXACTLY WHEN...NOT SURE
AND NOT EVEN SURE WHAT THE RADAR WILL LO0OK LIKE AT THE TIME OF
THE CHANGE BUT BETWEEN 21Z AND 00Z LOOKS TO BE THE BEST ESTIMATE
FOR THE CHANGE FM RAIN TO SNOW EXCEPT 02Z- 03Z KMIV AND KACY.
TONIGHT...LIFR CONDITIONS ARE EXPECTED THIS EVENING...AS RAIN
CHANGES TO SNOW FROM KPHL SOUTH AND EAST...AND SNOW CONTINUES
NORTH AND WEST. NORTH WINDS WILL GUST BETWEEN 25 AND 35
KNOTS...ESPECIALLY FROM KPHL SOUTH AND EAST. THE HEAVIEST
PRECIPITATION WILL FALL BETWEEN 0000 UTC AND 0600 UTC. AFTER 0600
UTC...CONDITIONS COULD SLOWLY IMPROVE THROUGH IFR AS WINDS SHIFT
TO THE NORTHWEST.
OUTLOOK...
SATURDAY-SATURDAY NIGHT...MVFR CONDITIONS POSSIBLE EARLY, THEN IMPROVING
TO VFR. GUSTY NORTHWEST WINDS THROUGH THE DAY, WITH GUSTS 25 TO 30
KNOTS, DECREASING BY SATURDAY NIGHT.
SUNDAY...VFR.
SUNDAY NIGHT...MOSTLY VFR...MVFR AND/OR IFR CIGS/VSBYS POSSIBLE VERY
LATE.
MONDAY...MVFR AND/OR IFR CIGS/VSBYS WITH AREAS OF RAIN...POSSIBLE
WINTRY MIX EARLY NORTH.
MONDAY NIGHT...IMPROVING TO VFR OVERNIGHT.
TUESDAY...MOSTLY VFR. GUSTY AFTERNOON WINDS 20-25 KNOTS.
&&
.MARINE...
CONFIDENCE IN STORM WARNING VERIFICATION IS LESS THAN AVERAGE BUT
WE CONTINUE THE HEADLINE TIL THIS RAPIDLY DEEPENING SFC LO E OF
THE VA CAPES PASSES WELL E OF NJK TONIGHT.
NO CHANGES TO THE MARINE HEADLINES EARLY THIS MORNING. THE 0000 UTC
NAM LOOKS TOO FAR WEST WITH ITS TRACK...AND THE 0000 UTC GFS IS A
BIT TOO FAR EAST. THE 0000 UTC ECMWF IS A COMPROMISE TRACK...AND ITS
OUTPUT HAS BEEN USED EXTENSIVELY FOR THIS FORECAST.
THE GRADIENT BETWEEN THE DEVELOPING SURFACE LOW OFF THE NORTH
CAROLINA COAST AND HIGH PRESSURE OFF THE NEW ENGLAND COAST IS
TIGHTENING TO SUPPORT SMALL CRAFT WINDS. A GRADUAL RAMP UP OF THE
GRADIENT CONTINUES INTO THE EARLY AFTERNOON.
BY EARLY TO MID AFTERNOON...THE GRADIENT SUPPORTS GALE FORCE WIND
GUSTS...ESPECIALLY OVER THE OCEAN WATERS. THE BEST GRADIENT APPEARS
TO OCCUR BETWEEN 2100 UTC AND 0300 UTC. AT THE SAME TIME...925 MB
WINDS INCREASE TO 45 TO 50 KNOTS OVER THE OCEAN WATERS. MODEL
SOUNDINGS OVER THE OCEAN WATERS SUGGEST THAT THE 50 KNOTS OF
MOMENTUM REMAINS JUST ABOVE THE TOP OF THE SUPPRESSED INVERSION.
HOWEVER...HEAVY RAIN COULD BRING SOME OF THIS MOMENTUM DOWN...
SUPPORTING GUSTS TO 50 KNOTS. WHILE THE GRADIENT...ESPECIALLY FROM
NON-NAM MODELS...DOES NOT APPEAR TO SUPPORT STORM FORCE GUSTS...THE
STORM WARNING REMAINS IN PLACE TO COVER GUSTS IN HEAVY RAIN ON THE
OCEAN. SEAS SHOULD JUMP QUICKLY THIS AFTERNOON AS THE EAST NORTHEAST
FETCH RAMPS UP...AND FOR THE MOST PART A COUPLE OF FEET WAS ADDED TO
THE WAVEWATCH MODEL OUTPUT FOR THIS AFTERNOON AND TONIGHT.
OVER DELAWARE BAY...THE GRADIENT IS NOT AS TIGHTEN...ESPECIALLY WITH
THE NON-NAM MODEL TRACKS. AS WITH THE OCEAN...THE BEST GRADIENT
FALLS IN THE 2100 TO 0300 UTC WINDOW...AND THIS IS THE BEST SHOT AT
STRONG GALE FORCE WINDS...ESPECIALLY IN THE MOUTH OF THE BAY. AS THE
SURFACE LOW PULLS ASTRIDE OF THE NEW JERSEY COAST...WINDS BACK TO
THE NORTHWEST AFTER 0600 UTC...AND GALE FORCE GUSTS ARE EXPECTED ON
ALL WATERS.
OUTLOOK...
GUSTY WINDS ACROSS THE WATERS WILL CONTINUE THROUGH SATURDAY INTO
SATURDAY EVENING. THE STORM WARNING ACROSS THE ATLANTIC COASTAL
WATERS WILL LIKELY BE REPLACED BY A GALE WARNING BY SATURDAY. WINDS
WILL CONTINUE TO DIMINISH INTO SATURDAY NIGHT, THROUGH SMALL CRAFT
ADVISORY CONDITIONS WILL LIKELY REMAIN. HOWEVER, AS HIGH PRESSURE
CONTINUES TO BUILD ACROSS THE AREA INTO SUNDAY WINDS WILL FINALLY
DROP BELOW ADVISORY LEVELS AND REMAIN SO THROUGH SUNDAY NIGHT.
HOWEVER, WINDS SHOULD RETURN TO SMALL CRAFT ADVISORY LEVELS MONDAY
AND MONDAY NIGHT AS A COLD FRONT MOVES THROUGH THE AREA; WINDS COULD
APPROACH GALE FORCE AGAIN. WINDS SHOULD DROP BACK BELOW ADVISORY
LEVELS TUESDAY AS THE PRESSURE GRADIENT SLACKENS SOME.
&&
.TIDES/COASTAL FLOODING...
A COASTAL FLOOD WARNING HAS NOW BEEN ISSUED FOR THE ATLANTIC
SEABOARD AS WELL AS THE LOWER DELAWARE BAY COVERING BOTH THIS
EVENING`S HIGH TIDE AS WELL AS SATURDAY MORNING`S. THE ASTRONOMICAL
FORECAST FOR THE HIGH TIDE THIS EVENING IS LOWER THAN SATURDAY
MORNING`S WHICH MAY KEEP THIS EVENING`S HIGH TIDE IN THE UPPER END
OF MINOR. HOWEVER, GUIDANCE CONTINUES TO INDICATE THAT SATURDAY
MORNING`S WILL REACH MODERATE. WE MAY EVEN APPROACH SEVERE COASTAL
FLOOD LEVELS FROM ATLANTIC CITY NORTHWARD SATURDAY MORNING.
THE UPPER PORTIONS OF THE DELAWARE BAY AND TIDAL DELAWARE RIVER DO
NOT LOOK LIKE THEY WILL REACH MINOR FLOOD LEVELS THIS EVENING, BUT
THE SATURDAY MORNING HIGH TIDE MAY GET TO MINOR.
WE ARE NOT EXPECTING COASTAL FLOODING ALONG THE EASTERN SHORE OF THE
CHESAPEAKE BAY AT THIS TIME
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WARNING UNTIL 6 AM EST SATURDAY FOR PAZ054-055-
061-062.
WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 6 AM EST
SATURDAY FOR PAZ060-101-103>106.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 6 AM EST
SATURDAY FOR PAZ070-071-102.
NJ...WINTER STORM WARNING UNTIL 6 AM EST SATURDAY FOR NJZ001-007-
008.
WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 6 AM EST
SATURDAY FOR NJZ009-010-012>015-019-020-026.
COASTAL FLOOD WARNING FROM 4 PM THIS AFTERNOON TO 11 AM EST
SATURDAY FOR NJZ012>014-020>027.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 6 AM EST
SATURDAY FOR NJZ016>018-021>025-027.
WIND ADVISORY UNTIL 5 AM EST SATURDAY FOR NJZ022>025-027.
DE...COASTAL FLOOD WARNING FROM 4 PM THIS AFTERNOON TO 11 AM EST
SATURDAY FOR DEZ002>004.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 6 AM EST
SATURDAY FOR DEZ001.
WIND ADVISORY UNTIL 5 AM EST SATURDAY FOR DEZ003-004.
MD...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 6 AM EST
SATURDAY FOR MDZ008.
MARINE...STORM WARNING UNTIL 6 AM EST SATURDAY FOR ANZ450>455.
GALE WARNING UNTIL 6 PM EST SATURDAY FOR ANZ430-431.
&&
$$
SYNOPSIS...DRAG/ROBERTSON
NEAR TERM...DRAG/HAYES 1118
SHORT TERM...HAYES
LONG TERM...ROBERTSON
AVIATION...DRAG/HAYES/ROBERTSON
MARINE...DRAG/HAYES/ROBERTSON
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
333 AM EST FRI FEB 8 2013
.DISCUSSION...
TODAY...
A BROAD STORM SYSTEM OVER THE CAROLINA COAST WILL UNDERGO RAPID
DVLPMNT TODAY AS IT BECOMES SANDWICHED BTWN TWO H25 JET STREAKS...A
100KT MAX OVER THE DEEP SOUTH AND A 110KT MAX OVER NEW ENGLAND AND
THE GEORGES BANK. AS THE SYSTEM WRAPS UP...IT WILL CRANK A COLD
FRONT RAPIDLY THRU CENTRAL FL...PULLING IT S OF LAKE OKEECHOBEE BY
MID AFTN. PREFRONTAL MOISTURE BAND IS UNIMPRESSIVE WITH H100-H70
MEAN RH VALUES LARGELY BLO 80PCT...MOST OF WHICH ALREADY HAS PUSHED
S OF 27N LAT (THE SRN MOST BNDRY FOR THE CWA).
PROGRESS OF THE FRNTL BNDRY WILL ONLY SERVE TO PUSH THE MOISTURE
FURTHER AWAY FROM CENTRAL FL. FURTHERMORE...LATEST RAP ANALYSIS
SHOWS A SINKING AIRMASS WITH POSITIVE MID LVL OMEGA...NEGATIVE UPR
LVL DIVERGENCE... AND NEUTRAL MID LVL VORTICITY ADVECTION. FCST WILL
BE FREE OF MENTIONABLE PRECIP.
AN EXTENSIVE STRATUS DECK ASSOCD WITH THE FRONTAL TROF ITSELF WILL
WORK ITS WAY INTO E CNTRL FL BY DAYBREAK...RESULTING IN MCLDY SKIES
THRU MID MORNING. THESE SHOULD BURN OFF BY MIDDAY...GIVING WAY TO
MSUNNY SKIES WITH SFC WINDS SHFTG FROM SW TO NW. DESPITE THE DVLPG
NW FLOW...CAA BEHIND THE FRONT WILL BE LIMITED AS THE SOURCE REGION
FOR THE POST FRONTAL AIRMASS WAS THE SRN PLAINS. MAX TEMPS IN THE
L/M70S FROM KISSIMMEE-MELBOURNE NWD...M/U70S TO THE S.
TONIGHT...
POST FRONTAL HIGH PRES RIDGE WILL PUSH ACRS THE DEEP SOUTH
OVERNIGHT...FORCING SFC WINDS TO VEER TO THE N. AN H85-H50 SHORT
WAVE TROF EXTENDING FROM THE ARKLATEX TO THE GREAT LAKES WILL DRIVE
A SECONDARY FRONT THRU THE FL PENINSULA OVERNIGHT. HOWEVER...THE
ASSOCD MOISTURE BAND IS EMBEDDED WITHIN A AREA OF STRONG ZONAL FLOW
THAT WILL CARRY THE BULK OF IT OFFSHORE BEFORE IT CAN PUSH INTO
CENTRAL FL. NO MENTIONABLE PRECIP CHANCES.
DESPITE THE NRLY FLOW AND THE ASSOCD POST FRONTAL DRYING...PGRAD
WILL REMAIN TIGHT ENOUGH TO PREVENT DECOUPLING. MIN TEMPS EXPECTED
TO REMAIN IN THE L/M50S INTERIOR COUNTIES...M/U50S COASTAL COUNTIES
WITH PORTIONS OF THE IMMEDIATE COAST HOLDING IN THE L60S S OF THE
CAPE.
WEEKEND...FAIRLY STRONG SFC HIGH (1030MB) OVER THE GREAT LAKES
EARLY SAT WILL TRANSLATE E/SE TO THE MID ATLC COAST BY SUNDAY
AFTERNOON. THIS WILL RESULT IN NE FLOW SATURDAY VEERING TO SE
FLOW SUNDAY AFTN. BREEZY AT THE COAST BOTH DAYS...ESP SUNDAY AS
PRES GRADIENT TIGHTENS A BIT. DRY W/NW FLOW ALOFT WILL KEEP THE
ATMOS DRY IN THE MID AND UPPER LEVELS. MID LEVEL RIDGING WILL
PRODUCE A SUBSIDENCE INVERSION AROUND 850 MB WHICH WILL TRAP SOME
LOW LEVEL MOISTURE BELOW. THIS WILL PRODUCE FAIR WEATHER CU THAT
PANCAKES BENEATH THE INVERSION SO EXPECT PARTLY CLOUDY SKIES.
SINCE THE MOISTURE LAYER WILL BE THIN...THERE WILL BE VERY
LITTLE CHANCE FOR RAIN BOTH DAYS. HOWEVER...CLOUD COVER LOOKS A
LITTLE MORE PERVASIVE SUNDAY. HIGH TEMPS SAT WILL BE IN THE LOW TO
MID 70S...WARMING TO THE MID AND UPPER 70S SUNDAY AS WINDS DEVELOP
A SOUTHERLY COMPONENT.
MON-THU...HIGH PRESSURE WILL CONTINUE SEAWARD WITH A RIDGE AXIS
EXTENDING WEST ACROSS THE FL PENINSULA MON-TUE. RESULTING
SOUTHERLY FLOW WILL PLACE EC FL SQUARELY BACK INTO THE WARM SECTOR
WITH HIGHS REACHING THE LOWER 80S MANY PLACES. MID LEVEL RIDGING
WILL BEGIN TO BREAK DOWN AS WESTERN U.S. UPPER TROUGH PUSHES EAST
AND A FRONTAL BOUNDARY SLOWLY PRESSES INTO THE SOUTHEAST U.S.
LATEST GFS/ECMWF MODELS SHOW LOW PRESSURE DEVELOPING ALONG THIS
FRONT NEAR THE CENTRAL GULF COAST AND RIDING E/NE TO THE CAROLINA
COAST...QUITE SIMILAR TO THE PATTERN WE ARE IN NOW. THE GFS HAS
TRENDED A LITTLE QUICKER BRINGING THE FRONT THROUGH WED...ECMWF
6-12 HOURS LATER. SUCH TIMING DIFFERENCES ARE NOT THAT UNUSUAL BUT
IT DOES UNDERSCORE SOME UNCERTAINTY WITH THE FORECAST IN THIS TIME
FRAME. BOTH MODELS INDICATE DEEPER MOISTURE AVAILABLE WHICH WOULD
PRODUCE A BETTER CHANCE FOR BENEFICIAL RAINFALL.
&&
.AVIATION...
THRU 08/16Z...SWRLY LLWS BTWN 25-30KTS BLO FL010...AREAS MVFR/LCL
IFR CIGS. AFT 08/16Z...VFR ALL SITES...WNDSHFT TO N/NW ARND 12KTS.
&&
.MARINE...
TODAY...HAZARDOUS BOATING CONDITIONS AS A COLD FRONT PUSHING INTO
THE NECK OF THE PENINSULA EARLY THIS MORNING GENERATES A FRESH TO
STRONG WRLY BREEZE THRU LATE AFTN. WINDS WILL VEER FROM SW TO NW
BEHIND THE FRONT BY MIDDAY AND GRADUALLY DIMINISH...BCMG A LIGHT TO
GENTLE BREEZE BY SUNSET. NEVERTHELESS THE PREVAILING OFFSHORE
COMPONENT WILL GENERATE SQUARE WAVES FOR MUCH OF THE DAY...BTWN
2-3FT NEARSHORE AND 4-6FT OFFSHORE. SCA THRU 21Z LOOKS GOOD.
TONIGHT...PGRAD WILL RETIGHTEN AS THE POST FRONTAL RIDGE PUSHES ACRS
THE DEEP SOUTH...RESULTING IN A MODERATE TO FRESH NRLY BREEZE. SEAS
2-3FT NEARSHORE AND 3-4FT OFFSHORE...BUT REMAINING CHOPPY IN THE
GULF STREAM DUE TO THE OPPOSING WIND/CURRENT DIRECTIONS.
SAT-SAT NIGHT...HIGH PRESSURE CONTINUES TO BE THE RULE AS IT BUILDS
ALONG THE EASTERN SEABOARD. NORTHERLY WINDS EARLY IN THE PERIOD WILL
VEER TO NORTHEAST THROUGH THE DAY...THOUGH A TIGHTER PRESSURE
GRADIENT WILL KEEP WIND SPEEDS AROUND 15 KTS NEAR THE COAST AND
15-18 KTS OFFSHORE. WILL LIKELY NEED CAUTION STATEMENT AT LEAST
FOR THE GULF STREAM. SEAS ARE EXPECTED TO INCREASE TO 3-5 FT NEAR
SHORE AND 4-6 OFFSHORE AS A NORTHEAST SWELL MOVES INTO THE AREA.
SUN-SUN NIGHT...HIGH PRES BUILDING NE OF THE BAHAMA BANK WILL
FORCE A GRADUAL WNDSHFT TO E/SE. LCL PGRAD SHOULD REMAIN TIGHT
ENOUGH TO SUPPORT SFC/BNDRY LYR WNDS BTWN 15-20KTS. SEAS 4-6FT
THRU THE DAY BUILDING TO 5-7FT OVERNIGHT AS THE ERLY SWELL TRAIN
CONTINUES TO IMPACT THE LCL ATLC.
MON-TUE...LCL PGRAD WILL RELAX AS THE RIDGE SETTLES OVER THE REGION.
WINDS BCMG S/SE 10-15KTS BY LATE AFTN...CONTG OVERNIGHT. SEAS 3-5FT
NEARSHORE AND 5-7FT OFFSHORE...SUBSIDING TO 2-4FT AND 3-5FT
RESPECTIVELY OVERNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 70 54 72 53 / 10 10 0 0
MCO 76 55 76 53 / 10 10 0 0
MLB 75 60 75 60 / 10 10 0 0
VRB 76 59 76 59 / 10 10 0 0
LEE 74 53 75 52 / 10 10 0 0
SFB 75 54 75 53 / 10 10 0 0
ORL 75 56 75 55 / 10 10 0 0
FPR 77 59 75 59 / 10 10 0 0
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM EST THIS AFTERNOON FOR
WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20
TO 60 NM OFFSHORE-WATERS FROM VOLUSIA BREVARD COUNTY LINE
TO SEBASTIAN INLET 20 TO 60 NM OFFSHORE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM....KELLY
AREA FORECAST DISCUSSION
NWS LINCOLN IL
843 PM CST SAT FEB 9 2013
.DISCUSSION...
ISSUED 835 PM CST SAT FEB 9 2013
CLOUDS CONTINUE TO INCREASE FROM SOUTHWEST TO NORTHEAST THIS
EVENING AS OUR NEXT WEATHER SYSTEM...CURRENTLY OVER SOUTHWEST
KANSAS...BEGINS TO LIFT NORTHEAST INTO THE CENTRAL PLAINS.
PRESSURE GRADIENT BEGINNING TO TIGHTEN UP OVER THE AREA AS
THE STORM BEGINS TO DEEPEN TO OUR WEST. SURFACE DEW POINTS
IN THE MID TO UPPER 50S CONFINED TO CENTRAL TEXAS THIS EVENING
BUT SHOULD HAVE NO PROBLEM STREAMING NORTHEAST OVERNIGHT ON
THE STRENGTH OF A 40-50 KT LOW LEVEL JET.
THE INITIAL BAND OF RAIN HAS STREAKED NORTHEAST TO JUST WEST OF
ST. LOUIS AND SHOULD PUSH EAST OF THE MISSISSIPPI RIVER IN THE
NEXT FEW HOURS AFFECTING OUR SOUTH AND WEST BY MIDNIGHT...AND THEN
WILL CONTINUE TO SHIFT OVER THE REMAINDER OF THE FORECAST AREA
INTO SUNDAY MORNING. LOOKS AS IF WE REACHED...OR WILL SHORTLY
REACH OUR LOWS FOR THE NIGHT AS THE COMBINATION OF CLOUDS AND AN
INCREASING SOUTHEAST WIND SHOULD HELP KEEP THE TEMPERATURES STEADY
OR SLOWLY RISING OVERNIGHT. HAVE MADE SOME ADJUSTMENTS TO THE
TIMING OF THE RAIN ACRS THE WEST AND SOUTH FOR LATER THIS EVENING.
STILL THE POSSIBILITY FOR SOME ISOLD CONVECTION BUT THAT LOOKS TO
BE MORE PROBABLE FOR SUNDAY MORNING IN THE 12Z-18Z TIME FRAME.
SHOULD HAVE THE UPDATED ZONES OUT BY 900 PM.
SMITH
&&
.AVIATION...
ISSUED 525 PM CST SAT FEB 9 2013
MAIN FORECAST CONCERN THIS PERIOD WILL BE TIMING OF RAIN INTO CENTRAL
ILLINOIS LATE TONIGHT...AND HOW QUICKLY CIGS DROP TO MVFR OR LOWER...
ESPECIALLY SUNDAY MORNING. NEXT WEATHER MAKER PUSHING INTO THE PLAINS
THIS EVENING WITH A VEIL OF MID AND HIGH CLOUDS STREAKING NE ACRS THE
REGION. FORECAST SOUNDINGS INDICATE A GRADUAL MOISTENING OF THE LOWER
LAYERS OF THE ATMOSPHERE AFTR 09Z WITH CIGS DECREASING TO MVFR AGAIN
BY DAWN SUNDAY...EXCPT AT KCMI WHERE CIGS WILL DROP TO MVFR OR LOWER
AROUND 13Z. EXPECT RAIN TO OVERSPREAD THE AREA AFTR MIDNIGHT TONIGHT
WITH A MORE CONCENTRATED AREA OF STEADY RAINFALL EXPECTED SUNDAY
MORNING BEFORE A MID LEVEL DRY SLOT MOVES ACRS THE MIDWEST SUNDAY
AFTN AND EVENING PUTTING AN END TO THE STEADIER RAINS...BEFORE WRAP
AROUND MOISTURE/MVFR CIGS AND STRONG WINDS MOVE IN SUNDAY NIGHT INTO
MONDAY. SOUNDING DATA INDICATES BORDERLINE LLWS CRITERIA ACRS THE WEST
AFTR 09Z...BUT THAT WILL BE THE TIME FRAME WHERE WE WILL BE SEEING
SOME GUSTS OCCUR SO WILL LEAVE OUT OF THE TAFS FOR THIS ISSUANCE.
OTHERWISE...SOUTHEAST WINDS OF 10 TO 15 KTS WILL PREVAIL TONIGHT WITH
THE SFC WINDS INCREASING LATE TONIGHT AND ESPECIALLY SUNDAY MORNING
OUT OF THE SE-S AT 15 TO 25 KTS WITH OCCASIONAL HIGHER GUSTS.
SMITH
&&
.PREV DISCUSSION...
ISSUED 210 PM CST SAT FEB 9 2013
PESKY LOW CLOUDS WHICH HAVE PLAGUED THE AREA RECENTLY FINALLY
HAVE BEEN SIGNIFICANTLY ERODING OVER THE LAST SEVERAL HOURS. EARLY
AFTERNOON SATELLITE IMAGERY SHOWING THEM MAINLY CONFINED TO AREAS
FROM THE ILLINOIS RIVER EAST TO CHAMPAIGN...ALTHOUGH THE REST OF
THESE CLOUDS SHOULD BE GONE BY LATE AFTERNOON. NOT MUCH BREAK IN
THE CLOUDS EXPECTED...AS MID AND HIGH CLOUDS WERE RAPIDLY
ADVANCING IN FROM THE SOUTHWEST. LARGE UPPER LOW SLOWLY ADVANCING
THROUGH THE 4 CORNERS REGION AND STILL ON TARGET TO AFFECT OUR
WEATHER LATE TONIGHT INTO EARLY NEXT WEEK.
SHORT TERM...TONIGHT THROUGH MONDAY...
MORNING MODELS REMAIN IN GOOD AGREEMENT WITH LIFTING THE UPPER LOW
INTO THE UPPER MISSISSIPPI VALLEY BY SUNDAY EVENING. SHOWERS ON
THE INCREASE ACROSS OKLAHOMA THIS AFTERNOON AND WILL BE ADVECTING
NORTHEAST TONIGHT AHEAD OF INTENSIFYING CYCLONE OVER THE PLAINS. A
LOT OF DRY AIR IN THE LOWER LEVELS NEEDS TO BE OVERCOME IN OUR
AREA...BUT RAP MODEL SOUNDINGS SHOW THE COLUMN MOISTENED UP IN
SPRINGFIELD BY 2 AM AND THE NORTHEASTERN CWA AROUND 4-5 AM. HAVE
INTRODUCED SOME SLIGHT CHANCE POPS IN THE FAR SOUTHWEST LATE THIS
EVENING...BUT HIGHER OVERNIGHT POPS REMAIN AFTER MIDNIGHT. HIGHEST
POPS DURING THE PERIOD WILL BE ON SUNDAY MORNING...WITH A RAPID
ENDING OF THE RAIN FROM WEST TO EAST DURING THE AFTERNOON. WILL
LINGER SOME SLIGHT CHANCE POPS INTO THE EVENING EAST OF I-57.
WINDS ARE ALSO A CONCERN DURING THE PERIOD. PRESSURE GRADIENT
TIGHTENS OVERNIGHT AS THE SURFACE LOW LIFTS NORTHEAST TO AROUND
OMAHA BY LATE SUNDAY MORNING. WILL LIKELY SEE SOME GUSTS OF AROUND
30-35 MPH LATE MORNING THROUGH MID AFTERNOON. WINDS WILL REMAIN
FAIRLY BREEZY AS THEY SWING AROUND TOWARD THE SOUTHWEST OR WEST
SUNDAY NIGHT...THEN GUSTS OF 30-40 MPH LIKELY AGAIN ON MONDAY.
HIGHEST GUSTS SHOULD BE ALONG AND NORTH OF THE I-74 CORRIDOR...
CLOSER TO THE SURFACE LOW.
LONG TERM...TUESDAY THROUGH SATURDAY...
SOUTHERN BRANCH OF THE JET STREAM STILL LOOKS TO BE THE ACTIVE ONE
MOST OF THIS WEEK...AS ANOTHER LOW IS DUG OUT OF THE DEEP TROUGH
IN THE SOUTHWEST U.S. AND MOVES EASTWARD TOWARD THE GULF COAST.
LONGER RANGE MODELS KEEP ANY OVERRUNNING PRECIP JUST TO OUR SOUTH
LATE TUESDAY NIGHT AND WEDNESDAY AS THE SURFACE LOW LIFTS TOWARD
THE MID-ATLANTIC COAST. MAIN FEATURE OF CONCERN IN THE EXTENDED IS
THE CARVING OUT OF A DEEP TROUGH OVER THE CENTER OF THE NATION
LATE THIS WEEK...MARKING A PERIOD OF COLDER WEATHER WHICH WILL
BEGIN FRIDAY AND LAST MUCH OF THE WEEKEND. THE GFS AND ECMWF
MODELS BOTH FORM A SURFACE REFLECTION IN THE TROUGH...BUT THE GFS
IS A LOT STRONGER AND FURTHER NORTH WITH ANY PRECIPITATION. SLIGHT
CHANCE POPS ARE STILL WARRANTED LATE IN THE WEEK DUE TO THE
UNCERTAINTY.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
533 PM CST SAT FEB 9 2013
.DISCUSSION...
ISSUED 210 PM CST SAT FEB 9 2013
PESKY LOW CLOUDS WHICH HAVE PLAGUED THE AREA RECENTLY FINALLY
HAVE BEEN SIGNIFICANTLY ERODING OVER THE LAST SEVERAL HOURS. EARLY
AFTERNOON SATELLITE IMAGERY SHOWING THEM MAINLY CONFINED TO AREAS
FROM THE ILLINOIS RIVER EAST TO CHAMPAIGN...ALTHOUGH THE REST OF
THESE CLOUDS SHOULD BE GONE BY LATE AFTERNOON. NOT MUCH BREAK IN
THE CLOUDS EXPECTED...AS MID AND HIGH CLOUDS WERE RAPIDLY
ADVANCING IN FROM THE SOUTHWEST. LARGE UPPER LOW SLOWLY ADVANCING
THROUGH THE 4 CORNERS REGION AND STILL ON TARGET TO AFFECT OUR
WEATHER LATE TONIGHT INTO EARLY NEXT WEEK.
SHORT TERM...TONIGHT THROUGH MONDAY...
MORNING MODELS REMAIN IN GOOD AGREEMENT WITH LIFTING THE UPPER LOW
INTO THE UPPER MISSISSIPPI VALLEY BY SUNDAY EVENING. SHOWERS ON
THE INCREASE ACROSS OKLAHOMA THIS AFTERNOON AND WILL BE ADVECTING
NORTHEAST TONIGHT AHEAD OF INTENSIFYING CYCLONE OVER THE PLAINS. A
LOT OF DRY AIR IN THE LOWER LEVELS NEEDS TO BE OVERCOME IN OUR
AREA...BUT RAP MODEL SOUNDINGS SHOW THE COLUMN MOISTENED UP IN
SPRINGFIELD BY 2 AM AND THE NORTHEASTERN CWA AROUND 4-5 AM. HAVE
INTRODUCED SOME SLIGHT CHANCE POPS IN THE FAR SOUTHWEST LATE THIS
EVENING...BUT HIGHER OVERNIGHT POPS REMAIN AFTER MIDNIGHT. HIGHEST
POPS DURING THE PERIOD WILL BE ON SUNDAY MORNING...WITH A RAPID
ENDING OF THE RAIN FROM WEST TO EAST DURING THE AFTERNOON. WILL
LINGER SOME SLIGHT CHANCE POPS INTO THE EVENING EAST OF I-57.
WINDS ARE ALSO A CONCERN DURING THE PERIOD. PRESSURE GRADIENT
TIGHTENS OVERNIGHT AS THE SURFACE LOW LIFTS NORTHEAST TO AROUND
OMAHA BY LATE SUNDAY MORNING. WILL LIKELY SEE SOME GUSTS OF AROUND
30-35 MPH LATE MORNING THROUGH MID AFTERNOON. WINDS WILL REMAIN
FAIRLY BREEZY AS THEY SWING AROUND TOWARD THE SOUTHWEST OR WEST
SUNDAY NIGHT...THEN GUSTS OF 30-40 MPH LIKELY AGAIN ON MONDAY.
HIGHEST GUSTS SHOULD BE ALONG AND NORTH OF THE I-74 CORRIDOR...
CLOSER TO THE SURFACE LOW.
LONG TERM...TUESDAY THROUGH SATURDAY...
SOUTHERN BRANCH OF THE JET STREAM STILL LOOKS TO BE THE ACTIVE ONE
MOST OF THIS WEEK...AS ANOTHER LOW IS DUG OUT OF THE DEEP TROUGH
IN THE SOUTHWEST U.S. AND MOVES EASTWARD TOWARD THE GULF COAST.
LONGER RANGE MODELS KEEP ANY OVERRUNNING PRECIP JUST TO OUR SOUTH
LATE TUESDAY NIGHT AND WEDNESDAY AS THE SURFACE LOW LIFTS TOWARD
THE MID-ATLANTIC COAST. MAIN FEATURE OF CONCERN IN THE EXTENDED IS
THE CARVING OUT OF A DEEP TROUGH OVER THE CENTER OF THE NATION
LATE THIS WEEK...MARKING A PERIOD OF COLDER WEATHER WHICH WILL
BEGIN FRIDAY AND LAST MUCH OF THE WEEKEND. THE GFS AND ECMWF
MODELS BOTH FORM A SURFACE REFLECTION IN THE TROUGH...BUT THE GFS
IS A LOT STRONGER AND FURTHER NORTH WITH ANY PRECIPITATION. SLIGHT
CHANCE POPS ARE STILL WARRANTED LATE IN THE WEEK DUE TO THE
UNCERTAINTY.
GEELHART
&&
.AVIATION...
ISSUED 525 PM CST SAT FEB 9 2013
MAIN FORECAST CONCERN THIS PERIOD WILL BE TIMING OF RAIN INTO CENTRAL
ILLINOIS LATE TONIGHT...AND HOW QUICKLY CIGS DROP TO MVFR OR LOWER...
ESPECIALLY SUNDAY MORNING. NEXT WEATHER MAKER PUSHING INTO THE PLAINS
THIS EVENING WITH A VEIL OF MID AND HIGH CLOUDS STREAKING NE ACRS THE
REGION. FORECAST SOUNDINGS INDICATE A GRADUAL MOISTENING OF THE LOWER
LAYERS OF THE ATMOSPHERE AFTR 09Z WITH CIGS DECREASING TO MVFR AGAIN
BY DAWN SUNDAY...EXCPT AT KCMI WHERE CIGS WILL DROP TO MVFR OR LOWER
AROUND 13Z. EXPECT RAIN TO OVERSPREAD THE AREA AFTR MIDNIGHT TONIGHT
WITH A MORE CONCENTRATED AREA OF STEADY RAINFALL EXPECTED SUNDAY
MORNING BEFORE A MID LEVEL DRY SLOT MOVES ACRS THE MIDWEST SUNDAY
AFTN AND EVENING PUTTING AN END TO THE STEADIER RAINS...BEFORE WRAP
AROUND MOISTURE/MVFR CIGS AND STRONG WINDS MOVE IN SUNDAY NIGHT INTO
MONDAY. SOUNDING DATA INDICATES BORDERLINE LLWS CRITERIA ACRS THE WEST
AFTR 09Z...BUT THAT WILL BE THE TIME FRAME WHERE WE WILL BE SEEING
SOME GUSTS OCCUR SO WILL LEAVE OUT OF THE TAFS FOR THIS ISSUANCE.
OTHERWISE...SOUTHEAST WINDS OF 10 TO 15 KTS WILL PREVAIL TONIGHT WITH
THE SFC WINDS INCREASING LATE TONIGHT AND ESPECIALLY SUNDAY MORNING
OUT OF THE SE-S AT 15 TO 25 KTS WITH OCCASIONAL HIGHER GUSTS.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
242 PM CST FRI FEB 8 2013
.DISCUSSION...
ISSUED 242 PM CST FRI FEB 8 2013
HIGH PRESSURE RIDGING CURRENTLY EXTENDING SOUTHWESTWARD FROM LAKE
SUPERIOR TOWARD OKLAHOMA/ARKANSAS. HAVE SEEN SOME PERIODIC
THINNING OF THE STRATOCUMULUS DECK IN THE EASTERN CWA...WITH SOME
MORE SIGNIFICANT EROSION COMING IN FROM WISCONSIN AND SOUTHWEST
MISSOURI. UPPER ANALYSIS AND WATER VAPOR IMAGERY SHOWING A LARGE
CUTOFF LOW DROPPING SOUTHWARD THROUGH CALIFORNIA...AND THIS
FEATURE WILL PLAY A SIGNIFICANT ROLE IN OUR WEATHER DURING THE
WEEKEND.
INITIAL FORECAST CHALLENGE WILL BE WITH THE CLOUD COVER
OVERNIGHT...OTHERWISE THE FOCUS WILL BE ON THE RAIN EXPECTED
DURING THE SECOND HALF OF THE WEEKEND.
SHORT TERM...TONIGHT THROUGH MONDAY...
CLOUD FORECAST WILL BE TRICKY OVERNIGHT. MOST OF THE MODELS ARE
STRUGGLING SOMEWHAT WITH THE EXISTING COVERAGE. THE HRRR...WHICH
IS FAIRLY CLOSE NOW...FILLS ANY GAPS BACK IN THIS EVENING. THE NAM
THINKS ANYTHING WEST OF THE MISSISSIPPI RIVER SHOULD BE CLEAR
ALREADY AND ERODES THE REST OF IT BY EARLY EVENING. THE RAP 925 MB
HUMIDITY APPEARS FAIRLY CLOSE RIGHT NOW AND SHOWS GRADUAL EROSION
FROM THE NORTH AND SOUTH THROUGH THE EVENING...BUT ITS FORECAST
SOUNDINGS SHOW THE INVERSION AT 950 MB REMAINING RATHER TIGHT
THROUGH THE NIGHT. HAVE USED A BLEND OF THE RAP 925 MB HUMIDITY AND
THE MOS GUIDANCE TO COME UP WITH THE SKY GRIDS...WHICH SHOW SKIES
BECOMING PARTLY CLOUDY AFTER MIDNIGHT.
HIGH PRESSURE RIDGE TO CONTINUE PUSHING EASTWARD THROUGH
SATURDAY...WITH WINDS COMING BACK AROUND TO THE SOUTHEAST BY LATE
AFTERNOON. IN THE MEANTIME...THE MODELS ARE IN FAIRLY GOOD
AGREEMENT IN LIFTING THE UPPER LOW INTO SOUTHEAST SOUTH DAKOTA BY
MIDDAY SUNDAY AND THE ASSOCIATED CYCLONE BECOMING VERTICALLY
STACKED DURING THE PROCESS. NOT MUCH CHANGE WAS NEEDED IN THE
GRIDS FOR THE RAIN TIMING LATE SATURDAY NIGHT THROUGH SUNDAY...BUT
HAVE BUMPED UP POP VALUES A LITTLE MORE. THE ASSOCIATED FRONTAL
BOUNDARY AND BACK EDGE OF THE RAIN WILL RAPIDLY SWEEP EASTWARD
DURING SUNDAY EVENING...AND SHOULD BE OUT OF THE AREA BEFORE
TEMPERATURES GET COLD ENOUGH FOR ANY SNOW.
SOUTHERLY WINDS ON SUNDAY WILL GUST TO AROUND 30 MPH OR SO...AND
WITH THE LOW SLOW TO EXIT THE AREA...AM EXPECTING ANOTHER WINDY
DAY ON MONDAY WITH WESTERLY WINDS GUSTING TO 30 MPH OR SO. THE
HIGHER WIND GUSTS ON MONDAY WILL BE NORTH OF I-72...CLOSER TO THE
LOW.
LONG TERM...TUESDAY THROUGH FRIDAY...
THE TRAILING END OF THE FRONT WILL GET HUNG UP ALONG THE GULF
COAST EARLY NEXT WEEK...AND WILL INTERACT WITH AN UPPER TROUGH
MOVING ALONG THE SOUTHERN JET STREAM. THIS WILL EFFECTIVELY CUT
OFF ANY MOISTURE ADVECTION THIS FAR NORTH...WITH DRY CONDITIONS
EXPECTED WITH THE NEXT TROUGH MOVING THROUGH THE NORTHERN STREAM
ON WEDNESDAY. LATE IN THE WEEK...THE LONGER RANGE MODELS BEGIN TO
DIVERGE. THE GFS IS MUCH MORE AGGRESSIVE IN DIGGING A TROUGH OVER
THE CENTRAL CONUS...CUTTING OFF AN UPPER LOW WHICH WOULD DRIFT
INTO ILLINOIS ON SATURDAY. THIS WOULD BE A WETTER AND COLDER
SCENARIO FOR US...VERSUS THE BROADER LONG WAVE TROUGH OF THE
ECMWF. HAVE LIMITED ANY POPS AT THE END OF THE WEEK TO THE SLIGHT
CHANCE RANGE FOR NOW.
GEELHART
&&
.AVIATION...
ISSUED 1138 AM CST FRI FEB 8 2013
17Z/11AM VISIBLE SATELLITE IMAGERY CONTINUES TO SHOW OVERCAST
CONDITIONS ACROSS CENTRAL ILLINOIS...ALTHOUGH A SUBSTANTIAL
THINNING IN THE CLOUDS IS EXPANDING ACROSS THE EAST. GIVEN
LATEST SATELLITE TRENDS...THINK A FEW GLIMPSES OF SUN WILL BE
LIKELY FROM KBMI AND KDEC EASTWARD THIS AFTERNOON...HOWEVER
GENERAL SKY COVER WILL REMAIN MOSTLY CLOUDY. MVFR CEILINGS WILL
GRADUALLY CLEAR AT THE EASTERN TERMINALS BY EARLY EVENING...THEN
FURTHER WEST AT BOTH KSPI AND KPIA AFTER 03Z. WINDS WILL INITIALLY
BE FROM THE NORTH AT AROUND 10KT THIS AFTERNOON...THEN WILL VEER
TO THE EAST TONIGHT...THEN TO THE SOUTH/SOUTHEAST BY SATURDAY
MORNING.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1241 AM EST FRI FEB 8 2013
.AVIATION...
DETERIORATING CONDITIONS ALREADY SETTLING IN AT KSBN WITH SPECIAL
JUST COMING IN FOR LIFR CIGS AND LOWERING VSBYS. KVPZ HAS WENT
DOWN TO 200 FT CIGS AND VSBYS AROUND A HALF MILE. HAVE GOTTEN MORE
AGGRESSIVE ON CIGS/VSBYS AT KSBN FOR A FEW HOURS AND WENT WITH
DRIZZLE FOR THE TIME BEING. SWITCH OVER LOOKS TO ARRIVE SOMEWHERE
AROUND 8Z AT KSBN. IN KFWA...BACK EDGE OF STEADIER LIGHT RAIN
SHOULD SWEEP THROUGH OVER THE NEXT HOUR...FOLLOWED BY DRIZZLE AND
FOG MUCH LIKE KSBN TILL LATER TONIGHT. SKEPTICAL MUCH IN THE WAY
OF ANY FROZEN PRECIP WILL OCCUR AT KFWA SO HAVE BACKED OFF ON VSBY
IMPACT THERE.
DRIER AIR WILL BEGIN TO QUICKLY WORK IN DURING THE DAY FRIDAY WITH
CLEARING EXPECTED BY EARLY AFTERNOON IN KSBN AND LATE AFTN AT
KFWA. CLEARING COULD OCCUR A BIT QUICKER THAN MODELS INDICATING
BUT HAVE WENT WITH THE ABOVE TIMING FOR NOW.
&&
.UPDATE...
DRY SLOT WORKING ACROSS WESTERN PORTIONS OF THE FORECAST AREA.
PATCHY DRIZZLE BEING OBSERVED IN SEVERAL LOCATIONS WITH FOG
DEVELOPMENT DROPPING VSBYS TO ONE HALF MILE OR LESS AT TIMES. WILL
NEED TO WATCH OUT FOR POSSIBLE FREEZING DRIZZLE DEPENDING ON SFC
TEMPS PRIOR TO ARRIVAL OF COLDER AIR. OTHERWISE...DRIZZLE/FOG
SHOULD CONTINUE TO TREK EASTWARD OVERNIGHT PRIOR TO TEMPS FALLING
BELOW FREEZING AND WHAT`S LEFT OF A WEAK DEFORMATION ZONE ACROSS
NE ILLINOIS MOVES IN. VSBYS WITH THIS AREA HAVE BEEN IN THE 1 TO 4
SM RANGE...WHICH ISN`T OVERLY FAVORABLE FOR ACCUMULATING SNOW. IF
ANY DOES OCCUR...LOCATIONS ALONG AND NORTH OF THE TOLL ROAD WOULD
SEE THE BEST CHANCE...BUT STILL LIKELY AN INCH OR LESS AS BEST
DYNAMICS AND DEEPER MSTR SHIFT EAST. MAY NEED TO DO SOME MINOR
ADJUSTMENT TO THE FORECAST BUT WILL SEE WHAT 1 AM OBS LOOK LIKE.
&&
.PREV DISCUSSION... /ISSUED 745 PM EST THU FEB 7 2013/
AVIATION/UPDATE...
CONTD NORTHWEST/LEFT SHIFT OF SFC LOW TRACK DRAW INTO NRN STREAM
SHORTWAVE TROF/HGHT FALL CENTER AS IT QUICKLY AMPLIFIES TO 100-130
M/12 HR FALLS ACRS SRN GRTLKS. WITH FALL CENTER INITIALLY WELL
LAGGED...EVOLVES TO A CLOSELY STACKED SFC-MIDTROPOSPHERIC SYSTEM BY
12 UTC FRI. THROUGH THE EVENING A SHARPER NW/N PULL OF MAX TW WITHIN
LWST HALF KM MATERIALIZES /WELL CAPTURED PER RAP ANALYSIS/ TO THEN
ABRUPTLY COLLAPSE PER INTENSE DYNAMIC COOLING AND UNQUESTIONABLY
EVAP COOLING SPCLY SERN HALF OF CWA. ONLY FAR SERN THERMAL PROFILE
TO SUPPORT LIQUID BYND 06 UTC. GIVEN A MORE ABRUPT THERMAL COLLAPSE
ANTICIPATE MORE OF A RAIN TO SNOW EVENT ACRS CWA. STILL ANTICIPATE
SOME SLEET SPCLY ACRS NRN CWA WITH MORE ENVIGORED DEEP/UVM NORTH OF
INTENSE LLVL FGEN FOCUS. RAPID CHANGEOVER TO SNOW QUICKLY FOLLOWED
BY ERASURE OF MSTR DEPTH AS DRY SLOT CONTS ENE ADVANCE. SHORT
SNOWFALL WINDOW ALONG WITH ANTECEDENT WARM/WET SFC SHOULD LIMIT
ACCUMS AND WL ADJUST DOWNWARD. STILL CHC OF FZDZ/FLURRIES MIX NEAR
DAYBREAK/FRIDAY MORNING WITH PASSAGE OF MIDLVL TROF/DCVA.
FOR AVN CONCERNS...SHARP/DEEP COOLING TO BRING RAPID SATURATION AND
ASSOCD LWR CIGS/BR FORMATION. AT KSBN QUICK TRANSITION FM VFR AT
PRESENT TO IFR/LIFR MET CONDS PROBABLE BY ABOUT 03-04 UTC. LIQUID TO
FROZEN/LIQUID MIX TO ALL SNOW IN RAPID SUCCESSION. WIND SHIFT/DRIER
AIR ALOFT TO BRING RAPID VSBY INCRS IN EARLY AM HOURS WITH CIGS
EVENTUALLY REBOUNDING TO ABOVE FUEL ALT AROUND 14 UTC. AT KFWA
SUSPECT A MORE ABRUPT CHANGEOVER TO FROZEN WITH STRONGEST LIFT/SLEET
POTNL REMAINING NORTH. AND AGAIN ABOVE FUEL ALT IN LATE AM HOURS.
CHCS FOR FZDZ/FLURRIES IN 10-14 UTC TIMEFRAME REMAIN TOO LOW FOR
INCLUSION ATTM.
PREV DISCUSSION... /ISSUED 348 PM EST THU FEB 7 2013/
SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
POTENTIAL OF MIXED PRECIP AND ACCUMULATING SNOW ACROSS WILL CONTINUE
TO BE THE MAIN FORECAST CONCERN FOR THE SHORT TERM. THE CURRENT ONLY
EXPECTED CHANGE TO HEADLINES WILL BE TO EXTEND THE WINTER WEATHER
ADVISORY THROUGH 12Z.
SFC LOW CONTINUES TO TAKE SHAPE ACROSS NORTHEAST MISSOURI THIS
AFTERNOON AS A FAIRLY STRONG UPPER VORT MAX APPROACHING WESTERN IOWA
DIVES THROUGH BASE OF UPPER TROUGH. WHILE AN OVERALL SLOWING TREND
HAS BEEN NOTED WITH THIS TROUGH THE PAST FEW DAYS...ANOTHER FACTOR
FOR SLOW PRECIP ARRIVAL FOR LOCAL AREA IS NORTHWARD ADVECTION OF
POCKET OF DRIER LOW/MID LEVEL AIR THAT HAS BEEN RESIDING ACROSS THE
MID MS RIVER VALLEY. TEMPS HAVE SOARED INTO THE UPPER 40S THIS
AFTERNOON ACROSS THE SOUTHWEST WHERE SNOW COVER HAS BEEN LACKING.
LOW/MID LEVEL THETA ADVECTION TO RAMP UP TOWARD EVENING AS UPSTREAM
UPPER TROUGH AXIS APPROACHES THE MID MS RIVER VALLEY. THIS WILL
ALLOW PRECIP SHIELD TO OVERSPREAD WESTERN PORTIONS OF THE AREA
TOWARD 00Z...AND LIKELY REACHING FAR EASTERN PORTIONS OF THE AREA IN
THE 04Z-06Z TIMEFRAME. EVEN FOR THE LATE AFTERNOON HOURS...IT
APPEARS AS THOUGH MOST OF BERRIEN COUNTY SHOULD RECEIVE MAINLY RAIN
AS PRECIP MOVES IN...WITH THE POSSIBLE EXCEPTION OF THE FAR NORTHERN
PORTIONS OF THE COUNTY WHERE SFC WET BULBS REMAIN BELOW FREEZING.
925 HPA HEIGHT MINIMUM SHOULD TRACK ACROSS SOUTHERN LAKE MICHIGAN
JUST AFTER 00Z RESULTING IN COLD ADVECTION PUSH TO SHIFT INTO
NORTHWEST PORTIONS OF THE AREA. PROFILES LOOK MORE CONDUCIVE FOR A
RAIN CHANGING TO SNOW SCENARIO ACROSS MOST OF THE FORECAST
AREA...WITH AN EXCEPTION ACROSS THE FAR NORTHEAST WHERE A MORE
PRONOUNCED SOUTHEAST LOW LEVEL WIND COMPONENT THROUGH THE DAY HAS
MAINTAINED A MORE PRONOUNCED LOW LEVEL DRY LAYER. THUS...HAVE
MAINTAINED FREEZING RAIN MENTION ACROSS THE FAR NORTHEAST THROUGH
THE MID TO LATE EVENING HOURS.
CONCERNS OF PREVIOUS FORECAST STILL INTACT WITH A BRIEF PERIOD OF
ALL SNOW EXPECTED THIS EVENING/EARLY PORTIONS OF OVERNIGHT THAT
COULD RESULT IN A QUICK 1 TO 3 OR 2 TO 4 INCH TYPE ACCUMULATION
ACROSS MAINLY SOUTHERN LOWER MICHIGAN COUNTIES. WHILE CONFIDENCE IN
AMOUNTS REMAINS SOMEWHAT LOW BASED ON EXACT CHANGEOVER
TIMING...STRONG LOW/MID LEVEL FRONTOGENETIC FORCING SHOULD RESULT IN
SOME GOOD SNOWFALL RATES FOR AT LEAST A 2 TO 3 HOUR PERIOD. BY LATE
EVENING...THERE ALSO APPEARS TO BE A MORE FAVORABLE OVERLAY BETWEEN
DEEPER UVM INDUCED FROM MORE ELEVATED MID LEVEL FRONTO FORCING AND
DGZ. INGREDIENTS METHOD APPROACH STILL INDICATES THE MOST PRONOUNCED
ELEVATED INSTABILITY PRECEDING SATURATED CONDITIONS. HOWEVER SOME
SIGNAL NOTED IN NAM QVEC/EPV ANALYSIS OF BETTER OVERLAPPING OF
FORCING/INSTABILITY ACROSS THE FAR NORTHEAST PORTIONS OF THE AREA AS
WEAK TROWAL FEATURE TRIES TO DEVELOP. SOME HESITATION TO GO WITH
HIGHER SNOW AMOUNTS ACROSS THIS LOCATION HOWEVER DUE TO A LONGER
POTENTIAL PERIOD OF MIXED PRECIP THROUGH THIS EVENING ACROSS THESE
LOCATIONS.
SECONDARY UPPER SPEED MAX TO DIVE THROUGH BASE OF THE UPPER TROUGH
LATE TONIGHT INTO FRIDAY MORNING. MID LEVEL DRY SLOT SHOULD RAPIDLY
WORK INTO THE AREA TOWARD MORNING WHICH COMBINED WITH WEAK FORCING
FROM AFOREMENTIONED SHORT WAVE/SPEED MAX MAY PROMOTE A PERIOD OF
PATCHY FREEZING DRIZZLE. AT THIS TIME IMPACTS WOULD APPEAR TO BE
QUITE LOW AND WILL MAINTAIN THE WINTER WEATHER ADVISORY ONLY THROUGH
12Z. REMAINDER OF SHORT TERM PERIOD WILL BE QUIET WITH UPPER LEVEL
RIDGING BUILDING BACK INTO THE WESTERN GREAT LAKES WEDNESDAY
AFTERNOON/NIGHT. STILL SOME QUESTIONS AS TO HOW QUICKLY LOW CLOUDS
WILL ERODE GIVEN STRENGTH OF LOW LEVEL FRONTAL INVERSION...AND IT IS
POSSIBLE SKY COVER MAY NEED TO BE INCREASED FOR THE AFTERNOON HOURS
ON FRIDAY.
LONG TERM... / SATURDAY THROUGH THURSDAY /
AN UPPER LEVEL RIDGE WILL BUILD INTO THE REGION SATURDAY INTO
SATURDAY NIGHT PROVIDING THE AREA WITH BENIGN WX AND SEASONABLE
TEMPS. A CLOSED UPPER LOW WILL LIFT NORTHEAST INTO THE UPPER MIDWEST
ON SUNDAY...FILLING EASTWARD INTO THE NORTHERN GREAT LAKES BY SUNDAY
NIGHT AND MONDAY. MODELS HAVE REMAINED CONSISTENT IN THE ASSOCIATED
OCCLUDED FRONT WORKING EAST THROUGH THE LOCAL AREA SUNDAY AFTERNOON
INTO SUNDAY NIGHT. THE FAR WEST TRACK OF THE MID LATITUDE CYCLONE
AND EARLY OCCLUSION PINCHING OFF DEEPER MOISTURE SHOULD COMBINE TO
LIMIT RAINFALL TOTALS AND DURATION SOMEWHAT. HOWEVER...STILL EXPECT
A DECENT/WIDESPREAD 0.25-0.50" OF RAIN WITH THE MAIN UNCERTAINTY AT
THIS RANGE BEING TIMING.
LEFTOVER/FRACTURED POSITIVELY TILTED UPPER TROUGH AXIS WILL BE
POSITIONED FROM THE GREAT LAKES SOUTHWEST INTO THE CENTRAL PLAINS BY
MONDAY AND TUESDAY....WITH WEST-SOUTHWEST FLOW ALOFT FROM THE
SOUTHERN PLAINS INTO THE EASTERN CONUS. AT THE SFC...A FILLING LOW
WILL TRACK EAST-NORTHEAST FROM THE NORTHERN GREAT LAKES ON MONDAY TO
QUEBEC ON TUESDAY. STRONG PRESSURE GRADIENT AND DEEPER MIXING IN LOW
LEVEL COLD ADVECTION (DRY SLOT ALOFT) REGIME ON MONDAY SHOULD RESULT
IN A WINDY/DRY DAY WITH TEMPS HOLDING STEADY OR EVEN DROPPING A FEW
DEGREES INTO THE MID 30S TO LOW 40S. LOW LEVEL RIDGING WILL BRING
LIGHTER WINDS TO THE AREA BY MONDAY NIGHT AND TUESDAY MORNING PER
LATEST GFS/ECMWF ITERATIONS.
THE ABOVE MENTIONED UPPER TROUGH AXIS LOOKS TO DROP SE THROUGH THE
AREA LATE TUESDAY INTO WEDNESDAY. WILL NEED TO WATCH AN EMBEDDED
SOUTHERN STREAM PV ANOMALY THAT WILL HAVE PLENTY OF JUICE TO WORK
GIVEN A WIDE OPEN GULF OF MEXICO AND SUBTROPICAL JET CONNECTION.
HOWEVER...LATEST TRENDS IN MODEL GUIDANCE SUGGESTS SUPPRESSION WITH
LEFTOVER NORTHERN STREAM CONFLUENCE SHUNTING THE DEVELOPING STORM
SYSTEM WELL SOUTH AND EAST OF THE IWX CWA. SUBTLE CHANGES IN MASS
FIELDS/NORTHERN STREAM INFLUENCE AND THIS WINTER STORM COULD TRACK
FARTHER TO THE NORTH BECOMING A CONCERN LOCALLY. FOR NOW WILL BUY
INTO THE DRY/SOUTH MODEL CONSENSUS SOLUTION. OTHERWISE...SEASONABLE
TEMPS EXPECTED TUESDAY THROUGH THURSDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR
MIZ077>081.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 1 AM EST SATURDAY FOR LMZ043-046.
&&
$$
SHORT TERM...MARSILI
LONG TERM...STEINWEDEL
AVIATION...FISHER
UPDATE...FISHER
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
252 PM CST FRI FEB 8 2013
.SYNOPSIS...
12Z UA ANALYSIS HAS TWO SEPARATE 850MB LOWS STARTING TO MERGE OVER
THE MID ATLANTIC AREA WITH HIGH PRESSURE ACROSS THE PLAINS.
SATELLITE TRENDS THROUGH MID AFTERNOON SHOW CLEARING OF THE LOW
CLOUDS ACROSS MN/WI MOVING INTO PARTS OF ILLINOIS IN A SUBSIDENCE
AREA. CLEARING OF THE LOW CLOUDS WAS ALSO OCCURRING ACROSS THE
SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY WHILE CLOUDS REMAIN
ACROSS THE MID MISSISSIPPI VALLEY.
18Z SFC ANALYSIS HAS A LOW IN SOUTHWEST SOUTH DAKOTA WITH A WARM
FRONT INTO NORTHEAST NEBRASKA. HIGH PRESSURE EXTENDED FROM WESTERN
LAKE SUPERIOR INTO TEXAS. DEW POINTS WERE IN THE TEENS AND 20S
ACROSS THE GREAT LAKES AND PLAINS WITH 30S AND HIGHER OVER THE OHIO
VALLEY AND DEEP SOUTH.
&&
.SHORT TERM...TONIGHT AND SATURDAY...
QUIET AND DRY CONDITIONS WILL BE SEEN ACROSS THE AREA TONIGHT AND
SATURDAY AS HIGH PRESSURE MOVES INTO THE EASTERN GREAT LAKES.
CLOUDS WILL HOLD ACROSS THE AREA FOR MUCH OF TONIGHT UNTIL RETURN
FLOW DEVELOPS AND ALLOWS THE SUBSIDENCE ACROSS KS/MO TO MOVE
NORTHWARD. CLOUDS ARE EXPECTED TO CLEAR FROM SOUTH TO NORTH FROM
JUST PRIOR TO DAWN THROUGH SATURDAY MORNING ACROSS THE AREA.
THERE ARE QUESTIONS AS TO WHETHER OR NOT THERE COULD BE ANY FOG
DEVELOPMENT TONIGHT. IF IT WOULD OCCUR...IT SHOULD BE VERY PATCHY
IN NATURE. THE RAP INITIALLY INDICATED SIGNIFICANT FOG
DEVELOPMENT TONIGHT BUT MORE RECENT TRENDS HAVE BACKED OFF ON ANY FOG
DEVELOPMENT.
AREAS THAT ARE CLEAR THIS EVENING AND OVER THE SNOW FIELD SHOULD SEE
TEMPERATURES IN THE TEENS AND POSSIBLY SOME SINGLE DIGITS.
ELSEWHERE...TEMPERATURES ARE EXPECTED TO REMAIN IN THE LOW TO MID
20S. ABOVE NORMAL TEMPERATURES ARE EXPECTED ON SATURDAY. ..08..
.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
DEEP SOUTHERLY FLOW WILL ALREADY BE IN PLACE SATURDAY EVENING...AND
WITH MOISTURE RAPIDLY SURGING NORTH THROUGH THE EVENING AND
OVERNIGHT...CLOUDS WILL BECOME WIDESPREAD AND OPAQUE EARLY ON...IF
NOT ALREADY AT SUNSET IN MOST PLACES. WINDS WILL ALSO BE ON THE
INCREASE THROUGH THE NIGHT....ALLOWING FOR TEMPERATURES TO REMAIN
ABOVE FREEZING...EVEN AFTER A POSSIBLE EVENING DIP TO LOWS EARLY IN
THE EVENING. THUS...DESPITE MODEL GUIDANCE SUGGESTING FREEZING RAIN
OVERNIGHT...IT REALLY SEEMS UNLIKELY GIVEN OUR SNOW PACK ONLY OVER
OUR FAR NORTH...AND THE INCREASING WAA AFTER AN ALREADY MILD DAY
PRECEDING IT. FOR NOW...WILL ONLY MENTION THIS POTENTIAL IN THE FAR
NORTH...OVER THE CURRENT SNOW AREA...BUT EVEN THERE THE THREAT FOR
NEW ICE FORMATION FROM FREEZING RAIN SEEMS QUITE LOW.
OTHERWISE...WAA OVERNIGHT SHOULD PRODUCE WIDESPREAD RAIN AFTER
MIDNIGHT AS THE COLUMN SATURATES...WITH A BAND OF MODERATE RAIN WITH
EMBEDDED THUNDER WORKING OVER THE AREA FROM SOUTH TO NORTH SUNDAY
THROUGH EARLY AFTERNOON. RAINFALL OF 0.25 TO 0.50 IS LIKELY WITH
SOME HIGHER POSSIBLE IN CONVECTION AND ANY TRAINING BANDED HEAVY
RAINS. AFTER 3 PM...A DRY SLOT SHOULD AFFECT MOST LOCATIONS...WITH
BREEZY/WINDY SOUTHWEST TO WEST WINDS WRAPPING IN. SOME SHOWERS MAY
YET OCCUR IN THE NORTH HALF AS WRAP AROUND MOISTURE MOVES BACK IN
DURING THE EVENING. SNOW SHOWERS ARE POSSIBLE LATE AND ON MONDAY
MORNING.
THERE SEEMS VERY LITTLE THREAT FOR ACCUMULATING SNOW WITH THIS
STORM...AS MODELS NOW HAVE TEMPERATURES ABOVE FREEZING MONDAY IN THE
DEEP MIXED OCCLUDED CYCLONE CIRCULATION. THE MILD AIR SHOULD CONTINUE
THROUGH MID WEEK BEFORE A SIGNIFICANT CLIPPER OR WESTERLY SHORT WAVE
MAY BRING ANOTHER SHOT AT RAIN OR SNOW TOWARD THURSDAY AND FRIDAY.
THE MODELS ARE IN POOR AGREEMENT ON THIS WAVE BEYOND THAT IT EXISTS.
THE GFS SHOWS A PERSISTENT SNOW...WHILE THE ECMWF SHOWS A GLANCING
SHOT OF RAIN AND SNOW GOING MAINLY NORTH.
ERVIN
&&
.AVIATION... /ISSUED 1043 AM CST FRI FEB 8 2013/
CHANGES FOR THE 18Z TAFS.
MVFR CONDITIONS WILL CONTINUE THROUGH AT LEAST 12Z/09. MOISTURE
TRAPPED UNDER AN INVERSION WILL REMAIN THERE AS THE HIGH MOVES
INTO THE GREAT LAKES TONIGHT. SOUTHERLY WINDS ON THE BACK SIDE OF
THE HIGH SHOULD RESULT IN CLEARING DEVELOPING ACROSS KS/MO THAT
BEGINS MOVING NORTH INTO IA/IL AFT 06Z/09. MVFR CONDITIONS SHOULD
IMPROVE TO VFR AFT 12Z/09. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1207 PM CST FRI FEB 8 2013
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
EXTENDED STRATUS THROUGH THE DAY IN MOST LOCATIONS. 12Z DVN
AND OAX SOUNDINGS HAD DEEP SATURATION THROUGH 100 MB IN THE STRATUS
DECK. NONE OF THE MODELS REALLY HANDLED THIS WELL. SURFACE RIDGE
WILL MOVE EAST TODAY AND BOUNDARY FLOW WILL BECOME SOUTHEASTERLY.
WITH THE LACK OF DRY ADVECTION IN THIS LAYER...NOT SURE IF THE
STRATUS WILL BREAK TONIGHT. THEREFORE...UPPED SKY COVER SOME. WILL
EVALUATE MORE THIS AFTERNOON. MINOR ADJUSTMENTS TO TEMPERATURES.
PREVIOUS DISCUSSION...MAIN FORECAST CONCERN IS REGARDING THE PESKY
STRATUS DECK AND TEMPS TODAY. NOT ANTICIPATING THE CURRENT STRATUS
SHIELD TO BUDGE MUCH TODAY WITH THE SURFACE HIGH SHIFTING ACROSS
SOUTHERN MN/NORTHEAST IA/SOUTHERN WI THROUGH THE AFTERNOON KEEPING
THE FORECAST IN WITHIN THE CAA. WINDS LOOK TO RELAX LATE THIS
MORNING BUT INVERSION WILL LINGER INTO THE AFTERNOON HOURS. BUFR
SOUNDINGS DEPICTING LOW LEVEL MOISTURE TO PERSIST THROUGH 21Z BEFORE
DISSIPATING SLIGHTLY. THE LATEST HRRR (06Z RUN) KEEPS CLOUD COVER
THROUGH AT LEAST 21Z AND THE WRF SIMULATED GOES-R DEPICTING STRATUS
TO PERSIST THROUGH MIDDAY...ESPECIALLY ACROSS NORTHERN IOWA. THE
925MB RH REMAINS AOA 80 PERCENT THROUGH 21Z BEFORE DECREASING. AS A
RESULT...HAVE INCREASED CLOUD COVER TO REFLECT THE PERSISTENT
STRATUS DECK AND LOWERED MAX TEMPS. HOWEVER...THIS WAS STILL AT OR
SLIGHTLY WARMER THAN GUIDANCE FOR MAX TEMPS TODAY.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
LATE WEEKEND SYSTEM REMAINS THE PRIMARY CONCERN WITH LITTLE CHANGE
IN THINKING FROM PREVIOUS FORECAST. IN THE MEAN TIME...FAIR WEATHER
IS EXPECTED TO END THE WEEK WITH RETURN FLOW BEGINNING TONIGHT
BRINGING MILD TEMPERATURES FOR SAT. CONDITIONS WILL CHANGE QUICKLY
INTO SAT NIGHT HOWEVER. WARM AIR/THETA-E ADVECTION WILL BEGIN
STARTING WITH WEAKER BANDS DURING THE EVENING WHICH WILL QUICKLY
TRANSITION TO A MORE ROBUST AREA OF PRECIP AS DEEP AND IMPRESSIVE
THERMODYNAMIC AND MID/UPPER LEVEL KINEMATIC FORCING EVENTUALLY
PHASE. ALTHOUGH TRANSIENT DUE TO THE RELATIVELY FAST
MOVEMENT...MODEL 290-300K ISENT LAYERS SHOW THIS SENSIBLE WEATHER
QUITE WELL AND SUGGEST DECENT PRECIP RATES LATE SAT NIGHT INTO SUN
MORNING WITH STRONG MOISTURE TRANSPORT NOTED IN THIS LAYER.
WIDESPREAD QUARTER TO HALF INCH PRECIP AMOUNTS ARE ANTICIPATED BY
MIDDAY. MODEL SURFACE AND WARM LAYER TEMPS ALOFT STILL SUGGEST
PRECIP TYPE WILL GENERALLY BE RAIN CENTRAL AND SOUTH...BUT BEGIN AS
MIX OF SLEET OR FREEZING RAIN NE QUARTER BEFORE TRANSITIONING TO ALL
RAIN BY 15Z SUN. DO NOT EXPECT WIDESPREAD PROBLEMS BUT WOULD NOT BE
SURPRISED TO SEE PATCHY TENTH OF AN INCH ACCUMS OF SLEET OR FREEZING
RAIN IN THE FAR NRN/NERN FEW TIERS OF COUNTIES. TOKEN MUCAPES AND
ELEVATED K INDICES ALSO CONTINUE TO SUGGEST THUNDER POTENTIAL EARLY
SUN MORNING SO KEPT THUNDER CENTRAL AND SOUTH.
ANY SIGNIFICANT UVM WILL HAVE DEPARTED ENTIRE FORECAST AREA BY 00Z
MON BUT WEAK LIFT AND LINGERING WRAP AROUND MOISTURE WILL KEEP LOW
CHANCES TRANSITIONING TO SNOW IN THE FORECAST LATER SUN NIGHT INTO
MON. MAIN STORY BY THIS TIME MAY BE WIND RATHER THAN PRECIP
HOWEVER. NAM AND GFS BOTH DEPICT 500M MIXED LAYER IN COLD ADVECTION
ACROSS NRN IA MON MORNING...BUT GFS IS MUCH MORE AGGRESSIVE. GFS
SUGGESTS G50 MPH POSSIBLE...NAM IN THE LOWER 30S AND THE ECMWF
SOMEWHERE IN BETWEEN. NOT GOING TOWARD THE HIGH END QUITE YET...BUT
THIS IS SOMETHING TO WATCH. ONLY CONCERN IN LATTER PERIODS WILL BE
PRECIP CHANCES AGAIN AROUND THU. ALTHOUGH TIMING IS
DIFFERENT...ECMWF A BIT FASTER THAN GFS...BOTH MODELS ARE MORE
ACTIVE IN NW FLOW THAN PREVIOUSLY SHOWN AND BRING A SHORT WAVE
THROUGH AROUND THAT TIME WHICH MAY RESULT IN SOME LIGHT SNOW.
&&
.AVIATION...08/18Z
THE STRATUS DECK CURRENTLY IN PLACE ACROSS THE DMX TAF SITES WILL
PERSIST FOR THE REST OF FRIDAY...INTO THE OVERNIGHT HOURS. AS A
RESULT WE ARE HOLDING MVFR CONDITIONS THROUGH THE CRITICAL TAF
PERIOD. AFTER SUNRISE SATURDAY...WE ARE EXPECTING THE STRATUS DECK
TO GRADUALLY START TO LIFT AND BREAK UP STARTING FROM THE SOUTH AND
EAST. MID AND UPPER LEVEL CLOUDS WILL BEGIN TO MOVE IN TOWARDS THE
END OF THIS TAF PERIOD.
WINDS SHOULD REMAIN IN THE 5 KT TO 10 KT RANGE FROM THE SOUTHEAST
FOR THE REST OF FRIDAY. AFTER 12Z SATURDAY WE ARE EPEXCTING THE
WINDS TO START TO VEER TO THE SOUTH AND INCREASE TO THE 10 KT TO 15
KT RANGE BY 18Z SATURDAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...SMALL
AVIATION...KOTENBERG
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1043 AM CST FRI FEB 8 2013
.UPDATE...
A SIGNIFICANT REVISION TO THE FCST HAS BEEN DONE REGARDING CLOUD
TRENDS.
MORNING ANALYSIS BRINGS QUESTIONS ON THE CLEARING TREND TODAY. WIND
FLOW ON THE 925MB CONDENSATION PRESSURE INDICATES THE DOWNWARD
MOTION ACROSS WISCONSIN WILL MOVE INTO THE FAR NORTHERN CWFA
AROUND MID DAY. ELSEWHERE...THE CLOUDS WILL REMAIN. AS SUCH THIS
WILL HAVE AN IMPACT ON TEMPERATURES WHERE THE CLOUDS REMAIN.
BASED ON THE RAP TRENDS...CLOUDS WILL REMAIN ACROSS MOST OF THE
CWFA THIS AFTERNOON AND TONIGHT. HOWEVER...DOWNWARD MOTION
DEVELOPS ACROSS MO/KS ON THE BACK SIDE OF THE HIGH LATE TONIGHT SO
BREAKS IN THE CLOUD COVER WILL DEVELOP THERE AND RESULT IN A
CLEARING TREND THAT MOVES NORTHWARD LATE TONIGHT AND INTO SATURDAY
MORNING.
AREAS THAT DO CLEAR TODAY WILL CLOUD BACK OVER AFTER SUNSET AND
SHOULD REMAIN CLOUDY UNTIL SATURDAY MORNING WHEN CLEARING OCCURS.
THE CLEARING SATURDAY WILL BE BRIEF AS ADVANCE CLOUDS TO THE NEXT
SYSTEM START ARRIVING DURING THE AFTERNOON. ..08..
&&
.AVIATION...
CHANGES FOR THE 18Z TAFS.
MVFR CONDITIONS WILL CONTINUE THROUGH AT LEAST 12Z/09. MOISTURE
TRAPPED UNDER AN INVERSION WILL REMAIN THERE AS THE HIGH MOVES
INTO THE GREAT LAKES TONIGHT. SOUTHERLY WINDS ON THE BACK SIDE OF
THE HIGH SHOULD RESULT IN CLEARING DEVELOPING ACROSS KS/MO THAT
BEGINS MOVING NORTH INTO IA/IL AFT 06Z/09. MVFR CONDITIONS SHOULD
IMPROVE TO VFR AFT 12Z/09. ..08..
&&
.PREV DISCUSSION... /ISSUED 527 AM CST FRI FEB 8 2013/
UPDATE...
SEEING CLEARING SKIES TAKING PLACE ACROSS WISCONSIN AND WAS
SPREADING SOUTHWARD. WILL CONTINUE WITH THE IDEA OF EXTENSIVE LOW
STRATUS THIS MORNING GIVING WAY TO CLEARING FROM NORTH TO SOUTH
DURING THE AFTERNOON. OTHERWISE NO CHANGES TO THE GOING FORECAST
AT THIS TIME.
AVIATION...
MVFR CIGS THROUGH THE MORNING THEN SKIES SHOULD CLEAR FROM NORTH
TO SOUTH DURING THE AFTERNOON WITH VFR CONDS AT ALL TAF SITES BY
LATE AFTERNOON. VFR CONDS EXPECTED TONIGHT AND SATURDAY. NORTH
WINDS 10 TO 15 KNOTS THIS MORNING DIMINISHING TO LESS THAN 10
KNOTS BY AFTERNOON. WINDS BECOMING SOUTHEAST LESS THAN 10 KNOTS
TONIGHT THEN SOUTHEAST TO SOUTH WINDS INCREASING TO 10 TO 20 KNOTS
ON SATURDAY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
536 AM CST FRI FEB 8 2013
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
UPDATE...EXTENDED STRATUS THROUGH THE DAY IN MOST LOCATIONS. 12Z
DVN AND OAX SOUNDINGS HAD DEEP SATURATION THROUGH 100 MB IN THE
STRATUS DECK. NONE OF THE MODELS REALLY HANDLED THIS WELL. SURFACE
RIDGE WILL MOVE EAST TODAY AND BOUNDARY FLOW WILL BECOME
SOUTHEASTERLY. WITH THE LACK OF DRY ADVECTION IN THIS LAYER...NOT
SURE IF THE STRATUS WILL BREAK TONIGHT. THEREFORE...UPPED SKY COVER
SOME. WILL EVALUATE MORE THIS AFTERNOON. MINOR ADJUSTMENTS TO
TEMPERATURES.
PREVIOUS DISCUSSION...MAIN FORECAST CONCERN IS REGARDING THE PESKY
STRATUS DECK AND TEMPS TODAY. NOT ANTICIPATING THE CURRENT STRATUS
SHIELD TO BUDGE MUCH TODAY WITH THE SURFACE HIGH SHIFTING ACROSS
SOUTHERN MN/NORTHEAST IA/SOUTHERN WI THROUGH THE AFTERNOON KEEPING
THE FORECAST IN WITHIN THE CAA. WINDS LOOK TO RELAX LATE THIS
MORNING BUT INVERSION WILL LINGER INTO THE AFTERNOON HOURS. BUFR
SOUNDINGS DEPICTING LOW LEVEL MOISTURE TO PERSIST THROUGH 21Z BEFORE
DISSIPATING SLIGHTLY. THE LATEST HRRR (06Z RUN) KEEPS CLOUD COVER
THROUGH AT LEAST 21Z AND THE WRF SIMULATED GOES-R DEPICTING STRATUS
TO PERSIST THROUGH MIDDAY...ESPECIALLY ACROSS NORTHERN IOWA. THE
925MB RH REMAINS AOA 80 PERCENT THROUGH 21Z BEFORE DECREASING. AS A
RESULT...HAVE INCREASED CLOUD COVER TO REFLECT THE PERSISTENT
STRATUS DECK AND LOWERED MAX TEMPS. HOWEVER...THIS WAS STILL AT OR
SLIGHTLY WARMER THAN GUIDANCE FOR MAX TEMPS TODAY.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
LATE WEEKEND SYSTEM REMAINS THE PRIMARY CONCERN WITH LITTLE CHANGE
IN THINKING FROM PREVIOUS FORECAST. IN THE MEAN TIME...FAIR WEATHER
IS EXPECTED TO END THE WEEK WITH RETURN FLOW BEGINNING TONIGHT
BRINGING MILD TEMPERATURES FOR SAT. CONDITIONS WILL CHANGE QUICKLY
INTO SAT NIGHT HOWEVER. WARM AIR/THETA-E ADVECTION WILL BEGIN
STARTING WITH WEAKER BANDS DURING THE EVENING WHICH WILL QUICKLY
TRANSITION TO A MORE ROBUST AREA OF PRECIP AS DEEP AND IMPRESSIVE
THERMODYNAMIC AND MID/UPPER LEVEL KINEMATIC FORCING EVENTUALLY
PHASE. ALTHOUGH TRANSIENT DUE TO THE RELATIVELY FAST
MOVEMENT...MODEL 290-300K ISENT LAYERS SHOW THIS SENSIBLE WEATHER
QUITE WELL AND SUGGEST DECENT PRECIP RATES LATE SAT NIGHT INTO SUN
MORNING WITH STRONG MOISTURE TRANSPORT NOTED IN THIS LAYER.
WIDESPREAD QUARTER TO HALF INCH PRECIP AMOUNTS ARE ANTICIPATED BY
MIDDAY. MODEL SURFACE AND WARM LAYER TEMPS ALOFT STILL SUGGEST
PRECIP TYPE WILL GENERALLY BE RAIN CENTRAL AND SOUTH...BUT BEGIN AS
MIX OF SLEET OR FREEZING RAIN NE QUARTER BEFORE TRANSITIONING TO ALL
RAIN BY 15Z SUN. DO NOT EXPECT WIDESPREAD PROBLEMS BUT WOULD NOT BE
SURPRISED TO SEE PATCHY TENTH OF AN INCH ACCUMS OF SLEET OR FREEZING
RAIN IN THE FAR NRN/NERN FEW TIERS OF COUNTIES. TOKEN MUCAPES AND
ELEVATED K INDICES ALSO CONTINUE TO SUGGEST THUNDER POTENTIAL EARLY
SUN MORNING SO KEPT THUNDER CENTRAL AND SOUTH.
ANY SIGNIFICANT UVM WILL HAVE DEPARTED ENTIRE FORECAST AREA BY 00Z
MON BUT WEAK LIFT AND LINGERING WRAP AROUND MOISTURE WILL KEEP LOW
CHANCES TRANSITIONING TO SNOW IN THE FORECAST LATER SUN NIGHT INTO
MON. MAIN STORY BY THIS TIME MAY BE WIND RATHER THAN PRECIP
HOWEVER. NAM AND GFS BOTH DEPICT 500M MIXED LAYER IN COLD ADVECTION
ACROSS NRN IA MON MORNING...BUT GFS IS MUCH MORE AGGRESSIVE. GFS
SUGGESTS G50 MPH POSSIBLE...NAM IN THE LOWER 30S AND THE ECMWF
SOMEWHERE IN BETWEEN. NOT GOING TOWARD THE HIGH END QUITE YET...BUT
THIS IS SOMETHING TO WATCH. ONLY CONCERN IN LATTER PERIODS WILL BE
PRECIP CHANCES AGAIN AROUND THU. ALTHOUGH TIMING IS
DIFFERENT...ECMWF A BIT FASTER THAN GFS...BOTH MODELS ARE MORE
ACTIVE IN NW FLOW THAN PREVIOUSLY SHOWN AND BRING A SHORT WAVE
THROUGH AROUND THAT TIME WHICH MAY RESULT IN SOME LIGHT SNOW.
&&
.AVIATION...08/12Z
EXPECTING STRATUS TO PERSIST THROUGH THE CRITICAL TAF PERIOD AND
BEGINS TO LIFT PAST 18Z TODAY. POTENTIAL IS THERE FOR MVFR CIGS TO
PERSIST LATE THIS AFTERNOON...BUT HAD MORE CONFIDENCE IN LIFTING THE
MVFR CIGS PAST 21Z TODAY. OTHERWISE...WINDS SHIFT TO THE EAST TODAY
THEN SOUTHEAST TO SOUTH BY TONIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...SMALL
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
404 AM CST FRI FEB 8 2013
.SHORT TERM /TODAY/...
MAIN FORECAST CONCERN IS REGARDING THE PESKY STRATUS DECK AND TEMPS
TODAY. NOT ANTICIPATING THE CURRENT STRATUS SHIELD TO BUDGE MUCH
TODAY WITH THE SURFACE HIGH SHIFTING ACROSS SOUTHERN MN/NORTHEAST
IA/SOUTHERN WI THROUGH THE AFTERNOON KEEPING THE FORECAST IN WITHIN
THE CAA. WINDS LOOK TO RELAX LATE THIS MORNING BUT INVERSION WILL
LINGER INTO THE AFTERNOON HOURS. BUFR SOUNDINGS DEPICTING LOW LEVEL
MOISTURE TO PERSIST THROUGH 21Z BEFORE DISSIPATING SLIGHTLY. THE
LATEST HRRR (06Z RUN) KEEPS CLOUD COVER THROUGH AT LEAST 21Z AND THE
WRF SIMULATED GOES-R DEPICTING STRATUS TO PERSIST THROUGH
MIDDAY...ESPECIALLY ACROSS NORTHERN IOWA. THE 925MB RH REMAINS AOA
80 PERCENT THROUGH 21Z BEFORE DECREASING. AS A RESULT...HAVE
INCREASED CLOUD COVER TO REFLECT THE PERSISTENT STRATUS DECK AND
LOWERED MAX TEMPS. HOWEVER...THIS WAS STILL AT OR SLIGHTLY WARMER
THAN GUIDANCE FOR MAX TEMPS TODAY.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
LATE WEEKEND SYSTEM REMAINS THE PRIMARY CONCERN WITH LITTLE CHANGE
IN THINKING FROM PREVIOUS FORECAST. IN THE MEAN TIME...FAIR WEATHER
IS EXPECTED TO END THE WEEK WITH RETURN FLOW BEGINNING TONIGHT
BRINGING MILD TEMPERATURES FOR SAT. CONDITIONS WILL CHANGE QUICKLY
INTO SAT NIGHT HOWEVER. WARM AIR/THETA-E ADVECTION WILL BEGIN
STARTING WITH WEAKER BANDS DURING THE EVENING WHICH WILL QUICKLY
TRANSITION TO A MORE ROBUST AREA OF PRECIP AS DEEP AND IMPRESSIVE
THERMODYNAMIC AND MID/UPPER LEVEL KINEMATIC FORCING EVENTUALLY
PHASE. ALTHOUGH TRANSIENT DUE TO THE RELATIVELY FAST
MOVEMENT...MODEL 290-300K ISENT LAYERS SHOW THIS SENSIBLE WEATHER
QUITE WELL AND SUGGEST DECENT PRECIP RATES LATE SAT NIGHT INTO SUN
MORNING WITH STRONG MOISTURE TRANSPORT NOTED IN THIS LAYER.
WIDESPREAD QUARTER TO HALF INCH PRECIP AMOUNTS ARE ANTICIPATED BY
MIDDAY. MODEL SURFACE AND WARM LAYER TEMPS ALOFT STILL SUGGEST
PRECIP TYPE WILL GENERALLY BE RAIN CENTRAL AND SOUTH...BUT BEGIN AS
MIX OF SLEET OR FREEZING RAIN NE QUARTER BEFORE TRANSITIONING TO ALL
RAIN BY 15Z SUN. DO NOT EXPECT WIDESPREAD PROBLEMS BUT WOULD NOT BE
SURPRISED TO SEE PATCHY TENTH OF AN INCH ACCUMS OF SLEET OR FREEZING
RAIN IN THE FAR NRN/NERN FEW TIERS OF COUNTIES. TOKEN MUCAPES AND
ELEVATED K INDICES ALSO CONTINUE TO SUGGEST THUNDER POTENTIAL EARLY
SUN MORNING SO KEPT THUNDER CENTRAL AND SOUTH.
ANY SIGNIFICANT UVM WILL HAVE DEPARTED ENTIRE FORECAST AREA BY 00Z
MON BUT WEAK LIFT AND LINGERING WRAP AROUND MOISTURE WILL KEEP LOW
CHANCES TRANSITIONING TO SNOW IN THE FORECAST LATER SUN NIGHT INTO
MON. MAIN STORY BY THIS TIME MAY BE WIND RATHER THAN PRECIP
HOWEVER. NAM AND GFS BOTH DEPICT 500M MIXED LAYER IN COLD ADVECTION
ACROSS NRN IA MON MORNING...BUT GFS IS MUCH MORE AGGRESSIVE. GFS
SUGGESTS G50 MPH POSSIBLE...NAM IN THE LOWER 30S AND THE ECMWF
SOMEWHERE IN BETWEEN. NOT GOING TOWARD THE HIGH END QUITE YET...BUT
THIS IS SOMETHING TO WATCH. ONLY CONCERN IN LATTER PERIODS WILL BE
PRECIP CHANCES AGAIN AROUND THU. ALTHOUGH TIMING IS
DIFFERENT...ECMWF A BIT FASTER THAN GFS...BOTH MODELS ARE MORE
ACTIVE IN NW FLOW THAN PREVIOUSLY SHOWN AND BRING A SHORT WAVE
THROUGH AROUND THAT TIME WHICH MAY RESULT IN SOME LIGHT SNOW.
&&
.AVIATION...08/06Z
STRATUS EXPECTED TO LINGER THROUGH MUCH OF THE TAF PERIOD WITH THE
SFC RIDGE AXIS TO MOVE THROUGH LATER FRIDAY ALLOW WINDS TO SHIFT
AROUND TO THE SOUTHEAST AND CLOUD DECK TO BEGIN TO DIMINISH.
UNCERTAINTIES SURROUND VSBYS AROUND SUNRISE INTO MID FRIDAY MORNING.
A FEW MODELS TRYING TO SEND NORTHERN TAF SITES AND KOTM DOWN TO
LIFR/IFR VSBYS RANGE. NOT CONFIDENT THAT THIS WILL OCCUR...SO HAVE
HIGHLIGHTED WITH SOME REDUCTION TO MVFR RANGE FOR NOW AND WILL HAVE
TO MONITOR OVER THE NEXT COUPLE OF HOURS AS CERTAINTY WILL BECOME
MORE APPARENT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...SMALL
AVIATION...MJB
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1146 PM CST THU FEB 7 2013
.AVIATION...
LOW PRESSURE OVER INDIANA WILL CONTINUE MOVING EAST AWAY FROM THE
AREA WHILE HIGH PRESSURE BUILDS INTO FROM THE NORTHERN PLAINS. A
LARGE AREA OF LOW CLOUDS WITH CIGS IN THE IFR TO MVFR RANGE MVFR
VSBSYS WAS LOCATED BETWEEN THE INDIANA LOW AND NORTHERN PLAINS
HIGH. NORTH WINDS ALSO BETWEEN THE TWO SYSTEM WILL CONTINUE TO
BRING IN DRIER AIR CAUSING VSBYS TO IMPROVE TO 6 MILES OR BETTER
EARLY THIS MORNING WITH CIGS INTO THE 1K TO 2K RANGE BY 12Z. THE
LOW CLOUDS ARE EXPECTED TO CLEAR THE AREA BY LATE MORNING OR EARLY
AFTERNOON WITH VFR CONDITIONS EXPECTED INTO FRIDAY EVENING.
DLF
&&
.PREV DISCUSSION... /ISSUED 926 PM CST THU FEB 7 2013/
UPDATE...
RADAR TRENDS SHOW THE SNOW HAS ENDED OVER ALL BUT THE FAR
NORTHEAST AND EASTERN PARTS OF THE CWFA. A ROUGH TIMING OF THE
BACK EDGE SUGGESTS THE SNOW SHOULD EXIT THE CWFA AROUND 05Z.
AMOUNT WISE...IT APPEARS THAT 1 TO 2 INCHES FELL IN THE HWY 20
CORRIDOR EAST OF KDBQ DOWN INTO CARROLL COUNTY. THESE NUMBERS ARE
BASED ON WHAT SPOTTER REPORTS WE HAVE RECEIVED SO FAR.
SOME MINOR TWEEKS HAVE BEEN DONE TO THE FCST FOR THE ENDING OF THE
SNOW. ALSO...BASED ON SATELLITE AND RAP TRENDS...CLEARING LATE
TONIGHT IS VERY DOUBTFUL AND HAVE KEPT THE AREA CLOUDY ALL NIGHT
WITH CLEARING FRIDAY MORNING. CAA IS SLOWLY DROPPING THE
TEMPERATURES BUT THE CURRENT OVERNIGHT LOWS MAY BE TOO COLD BY 2-4
DEGREES BASED ON CLOUDY SKIES. ...08..
PREV DISCUSSION... /ISSUED 304 PM CST THU FEB 7 2013/
SYNOPSIS...
12Z UA ANALYSIS HAS A WEAK 850MB LOW IN NORTHWEST MISSOURI WITH
ANOTHER IN THE OKLAHOMA PANHANDLE. A MOISTURE PLUME RAN FROM THE
GULF UP INTO THE MID MISSISSIPPI VALLEY WITH A STRONGER MOISTURE
PLUME OVER THE SOUTHEAST CONUS. RADAR TRENDS THROUGH MID AFTERNOON
CONTINUE TO SHOW WIDESPREAD RAIN ACROSS THE AREA WITH A MIX AND
CHANGE OVER TO SNOW ROUGHLY ALONG THE WI/IL BORDER.
18Z SFC ANALYSIS HAS A WEAK LOW WEST OF KMUT WITH A WARM FRONT
RUNNING ROUGHLY EAST ALONG I-80. THE COLD FRONT RAN SOUTH INTO
NORTHEAST OKLAHOMA. SEVERAL INVERTED TROFS RAN FROM THE LOW INTO
WISCONSIN AND SOUTHEAST MINNESOTA. DEW POINTS WERE IN THE 40S AND
50S ACROSS THE LOWER MISSISSIPPI VALLEY WITH 20S AND 30S OVER THE
GREAT LAKES AND MID MISSISSIPPI VALLEY.
SHORT TERM...TONIGHT AND FRIDAY...
DYNAMIC COOLING OF THE ATMOSPHERIC COLUMN HAS ALLOWED A MIX AND
CHANGE OVER TO SNOW ALONG THE HWY 20 CORRIDOR EAST OF KDBQ. CAA IS
NOW OCCURRING ACROSS THE FAR WESTERN PART OF THE CWFA BUT NO DYNAMIC
COOLING OF THE ATMOSPHERE HAS OCCURRED YET.
PER THE RAP TRENDS...DYNAMIC COOLING OF THE ATMOSPHERE WILL CONTINUE
TO SLOWLY PUSH THE MIX AND CHANGE OVER TO THE SOUTH LATE THIS
AFTERNOON AND EARLY EVENING FROM ROUGHLY THE MISSISSIPPI ON EAST AND
NORTH OF I-80. MINOR ACCUMULATIONS ARE POSSIBLE ON GRASSY SURFACES
WITH THE HIGHEST AMOUNTS OF 1-1.5 INCHES ALONG THE HWY 20 CORRIDOR
EAST OF KDBQ.
ACROSS THE REMAINDER OF THE CWFA IT WILL BE A RACE BETWEEN THE RAIN
ENDING AND THE COLD AIR ARRIVING. TRENDS WITH THE RAP SUGGEST A MIX
DEVELOPING JUST PRIOR TO THE RAIN ENDING OVER THE WESTERN HALF WITH
THE SOUTHERN MOST EXTENT ABOUT I-80.
THUS THE OVERALL SCENARIO IS ONE OF PRECIPITATION ENDING FROM WEST
TO EAST LATE THIS AFTERNOON THROUGH MIDNIGHT. BY MID EVENING AREAS
GENERALLY WEST OF A KDBQ TO KMQB LINE SHOULD BE DRY DUE TO DOWNWARD
MOTION AND INCREASING CONDENSATION PRESSURE DEFICITS.
AFTER MIDNIGHT...DRY CONDITIONS ARE EXPECTED. THE LARGE EXTENT OF
LOW CLOUDS UP INTO THE NORTHERN PLAINS INDICATES THAT CLEARING WILL
BE SLOW TO OCCUR. BREAKS IN THE CLOUD COVER SHOULD DEVELOP LATE
TONIGHT WITH CLEARING OCCURRING IN ERNEST STARTING AROUND SUNRISE.
QUIET AND DRY CONDITIONS WILL BE SEEN ON FRIDAY AS HIGH PRESSURE
BUILDS INTO THE AREA. SKIES WILL CONTINUE TO CLEAR DURING THE DAY
WITH MOSTLY SUNNY CONDITIONS EXPECTED BY MID AFTERNOON. ..08..
LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY...
OUR ATTENTION THIS LONG TERM FORECAST CONTINUES TO BE THE LARGE
SYNOPTIC STORM SET FOR THE WEEKEND INTO EARLY NEXT WEEK. GLOBAL AND
CONUS MODELS ARE IN GREAT AGREEMENT ON GENERAL DETAILS SHOWING A
DEEP/CLOSED UPPER TROF EXITING THE ROCKIES SATURDAY...SWEEPING
NORTHEAST SUNDAY...WHILE A STRONG SURFACE LOW MOVES FROM THE WESTERN
PLAINS TO SOUTHERN MN BY SUNDAY NIGHT. THIS PATH WILL BRING STRONG
SOUTH WINDS...AND MILD AIR TO THE REGION SATURDAY THROUGH
SUNDAY...ALONG WITH A PERIOD OF HIGH PROBABILITY RAIN SHOWERS AND
POSSIBLE THUNDER. RAINFALL TOTALS OF 0.25 TO 0.75 ARE CERTAINLY
POSSIBLE GIVEN THE STRONG FORCING...BUT ARE NOT LIKELY TO GET MUCH
HIGHER GIVEN THE PRONOUNCED DRY SLOT FORECAST TO SWEEP THROUGH THE
CWA SUNDAY AFTERNOON. BEHIND THIS SYSTEM...ALL MODELS SHOW WRAP
AROUND OCCLUDED LIGHT SNOW OR SNOW SHOWERS EITHER IN OUR NORTH
HALF...OR JUST NORTH OF THE CWA BORDER. THUS...SOME LOW POPS ARE IN
THE FORECAST FOR SUNDAY NIGHT AND MONDAY NORTH...AND DEPENDING ON
HOW THIS ALL UNFOLDS...THEY MAY NEED TO BE EXPANDED.
TEMPERATURES ARE ON THE MILD SIDE OF A GUIDANCE BLEND THROUGH THE
FORECAST GIVEN OUR HIGHLY CHANGEABLE SNOW COVER SITUATION TODAY. AT
THIS TIME...IT DOES APPEAR MOST IF NOT ALL SNOW SHOULD BE GONE BY
SUNDAY NIGHT. THUS...THE COLD INTRUSION BEHIND THIS LARGE SYSTEM MAY
LACK MUCH POTENCY.
ERVIN
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
341 PM CST FRI FEB 8 2013
.DISCUSSION...
THIS AFTERNOON AN UPPER LEVEL TROUGH WAS LOCATED ACROSS SOUTHERN NV
AND SOUTHEAST CA. SCATTERED TO BROKEN CIRRUS WAS MOVING NORTHEAST
ACROSS WESTERN AND CENTRAL KS...WELL AHEAD OF THE UPPER LEVEL
TROUGH. THE LOW CLOUDS AND FOG CONTINUE TO ERODE FROM EAST TO WEST
ACROSS NORTH CENTRAL KS. THE WESTERN COUNTIES CONTINUED TO REPORT
LOW STRATUS...BUT THROUGH THE LATE AFTERNOON HOURS THE STRATUS
SHOULD MIX OUT.
TONIGHT...SCT TO BKN CIRRUS WILL CONTINUE TO MOVE NORTHEAST ACROSS
THE CWA. THIS SHOULD PREVENT THE STRATUS AND FOG FROM REDEVELOPING
TONIGHT...ALSO SOUTHEAST WINDS WILL INCREASE THROUGH THE NIGHT TO
THE 5 TO 15 MPH RANGE. THE RAP MODEL FORECAST SOUNDINGS SHOW LOW
STRATUS AND THE POTENTIAL FOR FOG DEVELOPING BUT GIVEN INCREASING
HIGH CLOUDS AND SFC WINDS I WILL LEAN MORE TOWARDS THE 18Z NAM
MODEL. OVERNIGHT LOWS WILL ONLY DROP OFF INTO THE LOWER TO MID 30S.
SATURDAY...THE UPPER LEVEL TROUGH ACROSS SOUTHERN NV WILL BEGIN TO
LIFT NORTHEAST INTO CENTRAL CO AND THE FOUR CORNERS REGION. A LEE
SURFACE CYCLONE WILL DEEPEN THROUGH THE DAY ACROSS EASTERN CO.
SOUTHEAST-SOUTHERLY LOW-LEVEL WINDS WILL ADVECT GULF MOISTURE
NORTHWARD ACROSS WESTERN AND CENTRAL KS. WAA AND ISENTROPIC LIFT
WILL INCREASE ACROSS THE CWA DURING THE AFTERNOON HOURS. LIGHT RAIN
SHOWERS WILL BEGIN TO DEVELOP AFTER 18Z ACROSS CENTRAL KS AND MOVE
NORTHEAST ACROSS THE WESTERN HALF OF THE CWA DURING THE MID AND LATE
AFTERNOON HOURS. THE INSTABILITY MAY INCREASE JUST ENOUGH FOR
ISOLATED ELEVATED THUNDERSTORMS TO DEVELOP ACROSS THE SOUTHWEST
COUNTIES OF THE CWA BY LATE AFTERNOON. HIGH AND MID LEVEL CLOUDS
WILL INCREASE THROUGH THE DAY. HOWEVER...THE LOW-LEVEL WAA SHOULD
HELP HIGHS TO REACH AROUND 50 DEGREES TO THE MID 50S DESPITE THE
CLOUD COVER.
GARGAN
SATURDAY NIGHT AND SUNDAY...NOT MUCH CHANGE IN THE MODELS FROM
PREVIOUS FORECAST. BEST CHANCE FOR PRECIPITATIONS ACROSS THE CWA
LOOKS TO BE SATURDAY NIGHT FROM 00Z-12Z. MODELS IN GOOD AGREEMENT
WITH TIMING AND TRACK OF THE H5 CLOSED LOW TRACKING OVER WESTERN
KANSAS AND CENTRAL NEBRASKA. MODELS INDICATING GOOD CHANCES FOR
CONVECTION FROM THE 06Z-12Z WINDOW WITH 100KT 500MB JET STREAK...ROBUST
PV ANOMALY EXTENDING DOWN TO 590 MB...DEEP OMEGA...0-6KM SHEAR OF
AROUND 60-70KTS...AND MUCAPE VALUES OF 250-350 J/KG. CWA GETS DRY
SLOTTED BY 12Z-18Z AND BRINGS AN END TO THE PRECIPITATION.
MOISTURE IS NOT VERY ROBUST WITH THIS SYSTEM...AND WITH THE FAST
MOVEMENT OF THE SYSTEM AS WELL AS THE DRY SLOTTING
FEATURE...EXPECT TO SEE AT MOST A TENTH OF AN INCH FOR MOST
LOCATIONS. HOWEVER...A FEW LOCATIONS COULD SEE LOCALLY HIGHER
AMOUNTS WITH THUNDERSTORMS. SYSTEM MOVES OUT QUICKLY SUNDAY
MORNING...BUT LEFT LINGERING CHANCES ALONG THE FAR EASTERN
COUNTIES FOR THE MORNING HOURS. ATTM...DON`T EXPECT TO SEE ANY WRAP
AROUND MOISTURE...BUT THE ECMWF IS HINTING AT POTENTIALLY SOME OF
THE NORTHERN COUNTIES SUNDAY AFTERNOON. TEMPERATURES WILL REMAIN
WARM ENOUGH FOR ALL LIQUID PRECIPITATION. COLD FRONT PUSHES
THROUGH LATE SUNDAY MORNING AND SUNDAY AFTERNOON...AND CAA OCCURS
SUNDAY AFTERNOON WITH A DROP IN 850MB TEMPS FROM 5C TO -5C. WINDS
WILL BE GUSTY SUNDAY WITH A NEARLY 10MB PRESSURE GRADIENT ACROSS
THE CWA. NAM PRESSURE GRADIENT MAGNITUDES APPROACH 50 MICROBARS/KM
ATTM...SO EXPECT WIND GUSTS OF 35-40MPH OR POSSIBLY HIGHER MAINLY
OVER THE NORTHERN COUNTIES.
SUNDAY NIGHT THROUGH WEDNESDAY...UPPER LEVEL RIDGING AND SURFACE
HIGH DOMINATE THE PATTERN ACROSS KANSAS. TEMPERATURES SHOULD BE
CLOSE TO NORMAL FOR THIS TIME OF YEAR WITH HIGHS IN THE 40`S AND
LOWS IN THE 20`S UNDER MOSTLY SUNNY SKIES.
EXTENDED...NEXT FRONT TO IMPACT THE REGION WILL BE WEDNESDAY NIGHT
AND THURSDAY MORNING AS AN UPPER LEVEL TROF MOVING OUT OF WESTERN
CANADA MOVES EAST ALONG THE NORTHERN TIER STATES. MOISTURE WITH
THIS SYSTEM LOOKS LIMITED..SO NOT EXPECTING PRECIPITATION.
HOWEVER...STRONG CAA WILL OCCUR. GFS AND ECMWF DIVERGE WITH THE
AMOUNT OF COLD AIR THAT ADVECTS INTO THE AREA...BUT IF GFS IS
CORRECT...850MB TEMPS OF -20C COULD BE REALIZED BY THURSDAY NIGHT
AND INTO FRIDAY MORNING...POTENTIALLY BRINGING SOME VERY CHILLY
TEMPERATURES FOR FRIDAY AND POTENTIALLY A CHANCE FOR SNOW AS A
SHRTWV PUSHES IN FRIDAY.
01
&&
.AVIATION...
THE 12Z SOUNDING SHOWED A VERY THIN SATURATED LAYER WHICH
REPRESENTS THE STRATUS DECK. THE MVFR/IFR STRATUS ACROSS THE AREA
HAS BEGUN TO SCATTER OUT AS MIXING TAKES PLACE OVER KTOP AND KFOE.
THIS MIXING SHOULD CONTINUE THROUGH THE AFTERNOON WORKING WESTWARD
INTO KMHK AROUND 20Z. AFTER THAT ALL THE SITES WILL BE VFR FOR THE
REMAINDER OF THE PERIOD WITH A SOUTH TO SOUTHEAST WIND AROUND
10KT.
SANDERS
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
323 PM CST FRI FEB 8 2013
.DISCUSSION...
MAIN FORECAST CONCERN: TIMING AND PRECIPITATION CHANCES AS WELL AS
ASSOCIATED INTENSITY FOR SATURDAY AFTERNOON AND NIGHT. ADDITIONALLY
CHANCES FOR PRECIPITATION WITH A SYSTEM AT THE VERY END OF THE
PERIOD.
SYNOPSIS: TROUGH POSITIONED OFF THE WEST COAST CONTINUES ITS
MOVEMENT FURTHER INLAND AND SHALL SCOOT EASTWARD. THIS SYSTEM WILL
NOT BE CENTERED OVER THE HIGH PLAINS UNTIL 0Z ON SUNDAY AND WILL
QUICKLY TRAVEL NORTHEAST...HOWEVER A SECONDARY MORE SOUTHERLY SYSTEM
SHALL REMAIN BEHIND AND MOVE THROUGH THE SOUTHERN PLAINS AT THE
START OF THE WORK WEEK.
TONIGHT TO SUNDAY: STRATUS COULD LINGER IN THE OVERNIGHT HOURS
PARTICULARLY IN THE WESTERN FLANK OF THE CWA...BUT DO NOT ANTICIPATE
FOG AS OCCURRED THIS MORNING DUE TO MIXING WINDS. ONLY THE RAP
PLACES AN AREA OF FOG OVER THE FLINT HILLS LATE TONIGHT INTO
SATURDAY MORNING...YET CONFIDENCE IS NOT HIGH FOR THIS AREA. HIGHER
LIKELIHOODS APPEAR TO BE OVER EXTREME NORTH CENTRAL KANSAS AND
NEBRASKA.
AS THE LOW PRESSURE SYSTEM MOVES INTO THE CENTRAL PLAINS...THERE
WILL BE A TIGHTENED GRADIENT TO HELP PRODUCE GUSTY WINDS OF
APPROXIMATELY 30KTS IN AREAS OF CENTRAL KANSAS. THUS HAVE DECIDED TO
HOIST A WIND ADVISORY FOR NOON TO 7PM ON SATURDAY FOR ONLY A FEW
COUNTIES IN CENTRAL KANSAS. THIS MAY NEED TO BE EXPANDED SOUTHWARD
WITH INCREASING CONFIDENCE IN MIXING POTENTIAL...BUT DECIDED TO ONLY
PLACE ONE IN THE AREAS WITH HIGHEST DEGREE OF CONFIDENCE FOR NOW.
PLEASE CHECK THE LATEST WIND ADVISORY FOR FURTHER INFORMATION.
EXPECT THERE COULD BE A MORE NORTHERLY TRACK OF THE LOW TO DIVERT
SOME OF THE CHANCES FOR THUNDERSTORMS WITH THE RESPECTIVE
DYNAMICS/FORCING MOVING IN A SIMILAR FASHION. THE BEST CHANCE FOR
PRECIPITATION FOR THE CWA LOOKS TO BE SATURDAY NIGHT WITH HIGHEST
MOISTURE TRANSPORT OUT AHEAD OF THE SYSTEM AND 0-6KM BULK SHEAR OF
ABOUT 70-80KTS FOR EASTERN KANSAS...BUT CAPE VALUES ARE MINIMAL AT
BEST. THUNDERSTORM INITIATION HAS THE HIGHEST LIKELIHOOD ABOUT
MIDNIGHT ON SATURDAY TO SUNDAY. DECIDED TO MODIFY POP GRIDS TO
BETTER ACCOUNT FOR THIS TREND LEAVING CHANCES OUT AHEAD OF THE DRY
LINE AND COLD FRONTAL PASSAGE.
HIGH TEMPERATURES SHALL HOVER ABOVE NORMAL WITH VALUES AROUND 50 FOR
SATURDAY AND SUNDAY IN ALL AREAS EXCEPT SOUTHEASTERN KANSAS AND
ALONG THE KANSAS-OKLAHOMA BORDER WHERE MID 50S TO LOW 60S MAY BE
FOUND ON SATURDAY AND SUNDAY RESPECTIVELY.
MONDAY TO WEDNESDAY: A SECONDARY WAVE ASSOCIATED WITH THE LOW
PRESSURE SYSTEM FROM THE WEEKEND WILL LINGER OVER THE DESERT
SOUTHWEST AND MOVE EAST ACROSS THE SOUTHERN PLAINS ON TUESDAY. THIS
SYSTEM APPEARS TO BRING MINIMAL IMPACT TO THE FORECAST AREA AT THIS
TIME WITH ITS TRENDING SOUTHERN POSITION. TEMPERATURES ARE
ANTICIPATED TO RETURN TO NEAR NORMAL WITH HIGHS IN THE LOW TO MID
40S AND A TAD HIGHER FOR WEDNESDAY WITH BRIEF RIDGING.
THURSDAY TO FRIDAY: THE NEXT WAVE TO IMPACT THE AREA IS GOING TO
CREEP SOUTHWARD INTO THE CENTRAL PLAINS DURING THIS TIME FRAME.
MODELS ARE IN BETTER AGREEMENT WITH A SYSTEM MOVING
THROUGH...HOWEVER THE EXACT TIMING OF THE COLD AIR AND ANY
PRECIPITATION ARE A BIT IN QUESTION. COLD FRONTAL PASSAGE WILL BE ON
THURSDAY WITH COOLER AIR TO USHER IN BEHIND FOR FRIDAY WHERE HIGHS
MAY BE IN THE 30S AND NORTHERLY WINDS COULD BE 15 TO 20 MPH IN THE
AFTERNOON. BETTER AGREEMENT HAS PROMPTED SLIGHT AND CHANCES OF RAIN
OR SNOW TO OCCUR ON FRIDAY. THESE CHANCES AS WELL AS IMPACTS OF THE
COOLER AIR ON THE TEMPERATURES MAY AND WILL LIKELY BE ALTERED WITH
FUTURE FORECASTS.
JUANITA
&&
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MAIN HAZARDS: LINGERING LIFR/IFR CEILINGS AND VISIBILITIES UNTIL
20-22Z.
STRATUS/FOG SHIELD CONTINUES TO BE PROBLEMATIC ACROSS MOST OF
CENTRAL AND SOUTH CENTRAL KS. THE SHORT RANGE RUC MODEL AND VISIBLE
SATELLITE TENDS TO AGREE THE BEST...THAT THIS STRATUS DECK HAS COME
TO A HALT TO THE WEST OF KICT/KHUT. THE LIFR/IFR CIGS/VSBYS WILL
REMAIN LIKELY THROUGH AT LEAST 20Z FOR KICT/KHUT/KRSL AND KSLN...BUT
A GRADUAL IMPROVEMENT WILL OCCUR OVER THE NEXT FEW HOURS. DIURNAL
HEATING/MIXING SHOULD ALLOW THE STRATUS/FOG TO SLOWLY ERODE AFTER
20-22Z THIS AFTERNOON...WITH THE STRATUS LINGERING THE LONGEST AT
KSLN AND KCNU.
AFTER THIS CLOUD DECK COMPLETELY GOES AWAY AFTER 22Z...EXPECT VFR
CONDITIONS TO RETURN TO ALL TAF SITES.
KETCHAM
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 36 53 43 54 / 0 50 60 10
HUTCHINSON 35 52 42 52 / 0 50 60 0
NEWTON 35 52 44 52 / 0 50 60 10
ELDORADO 35 52 45 54 / 0 40 60 10
WINFIELD-KWLD 34 53 44 59 / 0 50 60 10
RUSSELL 34 51 35 47 / 0 50 60 10
GREAT BEND 37 51 37 49 / 0 50 50 0
SALINA 36 54 43 50 / 0 50 60 10
MCPHERSON 37 52 43 51 / 0 50 60 10
COFFEYVILLE 31 55 46 63 / 0 40 80 40
CHANUTE 31 55 46 61 / 0 40 80 40
IOLA 31 55 46 60 / 0 30 80 40
PARSONS-KPPF 32 54 47 62 / 0 40 80 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TO 7 PM CST SATURDAY FOR KSZ032-033-047-
048-050.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1137 AM CST FRI FEB 8 2013
...UPDATE TO AVIATION...
.DISCUSSION...
STRONG MID-UPPER LEVEL SUBSIDENCE WAS OCCURRING OVER THE CENTRAL
PLAINS IN THE OVERNIGHT HOURS BEHIND THURSDAYS SHORTWAVE. THE NEXT
UPPER SYSTEM WAS DIVING SOUTHEAST ALONG THE CALIFORNIA COAST WITH
CIRRUS PUSHING NORTHEAST OUT OF THE DESERT SOUTHWEST. NARROW
SURFACE HIGH PRESSURE WAS STRETCHED NORTH TO SOUTH FROM WESTERN
MINNESOTA TO CENTRAL KANSAS AT 08Z WITH STRATUS DECK NEAR ITS AXIS
AND SPREADING SOUTHWEST THROUGH EASTERN KANSAS. KOAX SOUNDING
SUGGESTS THE STRATUS IS QUIET SHALLOW AND A FEW HOLES IN UPSTREAM
STATES ARE EVIDENT VIA 11-3.9 MICRON SATELLITE PRODUCT. SOME FOG
HAS DEVELOPED IN NEBRASKA ALONG THE STRATUS DECK EDGE...AND SOME
MAY YET FORM SOUTH INTO KANSAS. WILL MONITOR LATEST TRENDS FOR ANY
INCLUSION.
MODELS CONTINUE TO STRUGGLE WITH THE STRATUS...WITH ONLY THE RAPID
UPDATE MODELS HAVING A CLUE. THEIR TRACK RECORD WITH SUCH FEATURES
IS NOT GREAT...WITH THIS FORECASTER EXPERIENCING A WET/COOL BIAS
FROM THE RAP ON MANY EVENTS. RECENT RUNS OF IT AND THE HRRR SUGGEST
CLOUDY CONDITIONS WILL INTO THE AFTERNOON HOURS. THE RIDGE AXIS MAKE
SLOW EASTWARD PROGRESS TODAY...WITH EAST TO SOUTHEAST WINDS
DEVELOPING...AND DOES NOT BODE WELL FOR A FAST CLEARING...BUT IF THE
HOLES CAN BE MAINTAINED THE PEAKS OF INSOLATION WOULD HELP BURN THE
STRATUS OFF. WILL KEEP SIGNIFICANT CLOUDS IN PLACE THROUGH LATE
MORNING AND TAKE A FEW DEGREES OF HIGH TEMPERATURES...BUT THIS IS A
LOW CONFIDENCE FORECAST FOR THESE ELEMENTS. INCREASING SOUTH WINDS
AND THICKENING HIGH CLOUDS SHOULD KEEP TEMPS IN THE LOWER 30S FOR
THE BULK OF THE AREA.
MOISTENING PROCESS AHEAD OF THE UPSTREAM LOW BRINGS BACK TO WELL
ABOVE NORMAL LEVELS BY SATURDAY AFTERNOON...WITH MEAGER LOW-MID
LEVEL WARM AIR ADVECTION PERHAPS LEADING TO ISOLATED TO SCATTERED
PRECIP BREAKING OUT. INSTABILITY AND FORCING INCREASE SATURDAY NIGHT
AS THE UPPER ENTERS THE CENTRAL PLAINS. MID LEVEL LAPSE RATES NEAR
THE 8C/KM RANGE WITH A BIT OF ELEVATED CAPE RESULTING...BUT GOOD
1-6KM SHEAR APPEARS TO COME WITH THE DRY SLOT. MODELS NOT TERRIBLY
STRONG WITH QPFS AND OVERALL COVERAGE OF PRECIP IS SOMEWHAT IN
QUESTION AS THIS POINT. WILL KEEP POPS IN THE LIKELY RANGE AT THIS
RANGE.
PRECIP STILL ON TRACK TO RAPIDLY EXIT SUNDAY AS WEST-SOUTHWEST FLOW
DEEPENS THROUGH COLUMN. MAIN CONCERN FOR THIS PERIOD APPEARS TO BE
WINDS AS SOME SOLUTIONS MIX SURFACE PARCELS WELL INTO THE
MID-TROPOSPHERE IN THE AFTERNOON AS STRONG PRESSURE RISES TAKE
PLACE. COLD AIR ADVECTION IN THE LATE DAY MAY KEEP TEMPS STEADY TO
FALLING IN THE NORTHWEST.
NEXT TROF TO ROTATE SOUTHEAST INTO THE SOUTHERN PLAINS IN MONDAY
NIGHT TO TUESDAY NIGHT PERIODS WITH WESTERLY FLOW DOMINATING MUCH OF
THE COLUMN. THIS SHOULD KEEP TEMPS IN THE NEAR TO ABOVE NORMAL RANGE
INTO THE MID WEEK. MODELS DO BEGIN TO DIVERGE WITH SUBSEQUENT
NORTHWEST FLOW WAVES BY LATE WEEK HOWEVER.
65
&&
.AVIATION...
THE 12Z SOUNDING SHOWED A VERY THIN SATURATED LAYER WHICH
REPRESENTS THE STRATUS DECK. THE MVFR/IFR STRATUS ACROSS THE AREA
HAS BEGUN TO SCATTER OUT AS MIXING TAKES PLACE OVER KTOP AND KFOE.
THIS MIXING SHOULD CONTINUE THROUGH THE AFTERNOON WORKING WESTWARD
INTO KMHK AROUND 20Z. AFTER THAT ALL THE SITES WILL BE VFR FOR THE
REMAINDER OF THE PERIOD WITH A SOUTH TO SOUTHEAST WIND AROUND
10KT.
SANDERS
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1131 AM CST FRI FEB 8 2013
.UPDATE...
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MAIN HAZARDS: LINGERING LIFR/IFR CEILINGS AND VISIBILITIES UNTIL
20-22Z.
STRATUS/FOG SHIELD CONTINUES TO BE PROBLEMATIC ACROSS MOST OF
CENTRAL AND SOUTH CENTRAL KS. THE SHORT RANGE RUC MODEL AND VISIBLE
SATELLITE TENDS TO AGREE THE BEST...THAT THIS STRATUS DECK HAS COME
TO A HALT TO THE WEST OF KICT/KHUT. THE LIFR/IFR CIGS/VSBYS WILL
REMAIN LIKELY THROUGH AT LEAST 20Z FOR KICT/KHUT/KRSL AND KSLN...BUT
A GRADUAL IMPROVEMENT WILL OCCUR OVER THE NEXT FEW HOURS. DIURNAL
HEATING/MIXING SHOULD ALLOW THE STRATUS/FOG TO SLOWLY ERODE AFTER
20-22Z THIS AFTERNOON...WITH THE STRATUS LINGERING THE LONGEST AT
KSLN AND KCNU.
AFTER THIS CLOUD DECK COMPLETELY GOES AWAY AFTER 22Z...EXPECT VFR
CONDITIONS TO RETURN TO ALL TAF SITES.
KETCHAM
&&
.PREV DISCUSSION... /ISSUED 1006 AM CST FRI FEB 8 2013/
UPDATE...
STRATUS AND PESKY DENSE FOG CONTINUE TO PLAGUE MOST OF CENTRAL AND
SOUTH CENTRAL KANSAS AT THIS TIME. THIS AREA OF FOG/STRATUS IS
GRADUALLY DRIFTING SW...WITH THE FIRST 30 MILES OF THE LEADING EDGE
OF THE STRATUS WHERE THE DENSE FOG IS LOCATED. VSBYS HAVE BEEN
AVERAGING 1/4 TO 1/2 MILE ALONG THIS LEADING EDGE. PLAN ON HANDLING
THIS WITH A SHORT TERM NOWCAST DUE TO THE TRANSIENT NATURE OF THE
FOG. SHORT RANGE RUC MODEL IS VERY PESSIMISTIC IN LIFTING/BURNING
THIS FOG FOR OFF UNTIL AFTER 18-19Z. SO HAVE EXTENDED THE DURATION
OF THE FOG/STRATUS UNTIL THEN. THINK THIS DECK WILL BURN OFF SOME
FROM THE EDGES...BEFORE BEGINNING TO LIFT BACK TO THE NORTH LATE
THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 510 AM CST FRI FEB 8 2013/
AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MAIN HAZARDS: LIFR/IFR CEILINGS AND VISIBILITIES THIS MORNING.
STRATUS SHIELD CONTINUES TO MOVE SOUTHWESTWARD ACROSS EASTERN KS
EARLY THIS MORNING. THE HRRR 3KM AND RUC13 SEEM TO HAVE A BETTER
HANDLE ON THE MORE MOIST BOUNDARY LAYER AIR. LIFR CIGS/VSBYS WILL
REMAIN LIKELY FOR MUCH OF THE MORNING ON THE SOUTHWESTERN FRINGES
OF THIS STRATUS SHIELD...AFFECTING RSL...SLN...HUT...AND ICT. CNU
SHOULD STAY MAINLY AT LOW END OF MVFR RANGE. DIURNAL
HEATING/MIXING SHOULD ALLOW STRATUS TO ERODE MIDDAY INTO THIS
AFTERNOON AND WILL HAVE CNU CLEARING THE LAST ~21Z.
JMC
PREV DISCUSSION... /ISSUED 250 AM CST FRI FEB 8 2013/
DISCUSSION...
THE PRIMARY FORECAST CONCERN WILL BE THE STORM SYSTEM EXPECTED TO
IMPACT THE AREA OVER THE WEEKEND BRINGING THE POSSIBILITY FOR SOME
HAIL SATURDAY NIGHT. CURRENTLY THIS STORM SYSTEM WAS DIGGING INTO
NORTHERN CALIFORNIA WHILE A MID/UPPER LEVEL RIDGE WAS TRANSLATING
EASTWARD OUT OF THE ROCKIES.
TODAY-TONIGHT...AT THE SURFACE...AN AREA OF LOW CLOUDS AND PATCHY
FOG WERE BACKING ACROSS THE FORECAST AREA EARLY THIS MORNING. SINCE
MANY OF THE SHORT-TERM MODELS HAD TROUBLE INITIALIZING THIS
ACTIVITY...UNCERTAINTY IN HOW QUICK IT MIXES OUT OR HOW FAR IT ADVECTS
WEST WILL LEAD TO A LOW CONFIDENCE TEMPERATURE FORECAST
TODAY...ESPECIALLY EAST OF THE KANSAS TURNPIKE WHERE STRATUS MAY
LINGER INTO THE AFTERNOON HOURS. TRENDED HIGHS LOWER EAST OF THE KTA
WHERE HIGHS MAY STRUGGLE TO CLIMB OUT OF THE 40S. FURTHER
WEST...WITH GREATER CHANCES FOR MORE PROLONGED INSOLATION/BREEZY
SOUTHERLY WINDS HIGHS MAY REACH THE MID 50S. EXTENSIVE MID AND UPPER
LEVEL CLOUDS ARE EXPECTED TO SPREAD OVER THE AREA LATE TONIGHT
WITHIN DIFFLUENT MID/UPPER FLOW DOWNSTREAM OF THE APPROACHING STORM
SYSTEM AND WITH THE EXPECTED SOUTHERLY WINDS...MILD LOWS ARE
ANTICIPATED WITH VALUES REMAINING IN THE MID/UPPER 30S ACROSS MUCH OF
THE AREA.
SATURDAY-SUNDAY...LOW LEVEL MOISTURE WILL SURGE NORTH DURING THE DAY
ON SATURDAY WHILE THE MORE ROBUST MOISTURE TRANSPORT/MUCAPE IS
PROGGED TO ARRIVE SAT NIGHT. WILL MAINTAIN MID POPS SAT AFTERNOON
WHILE HIGHER PROBABILITIES SHOULD ARRIVE AHEAD OF THE DRYLINE
SATURDAY NIGHT. THIS DRYLINE IS PROGGED TO SWEEP EAST ACROSS THE
AREA REACHING THE FLINT HILLS AREA BY AROUND 12Z SAT. THIS SHOULD
BRING A RAPID DEMISE TO ANY LINGERING SHOWER ACTIVITY WHILE WESTERLY
WINDS WITHIN THE DRY SECTOR SHOULD RESULT IN ANOTHER MILD DAY WITH
HIGHS RANGING FROM THE UPPER 40S NEAR KRSL TO THE MID 60S OVER
EXTREME SOUTHEAST KANSAS. ANY PRECIPITATION ON THE WESTERN/SOUTHWEST
PERIPHERY OF THE STORM SYSTEM IS EXPECTED TO REMAIN NORTH AND WEST
OF THE FORECAST AREA ON SUNDAY BUT CLOUDS MAY IMPACT FORECAST HIGHS
ACROSS THE I-70 CORRIDOR.
MONDAY-THURSDAY...ANOTHER STORM SYSTEM WILL ARRIVE ON THE HEELS OF
THE WEEKEND STORM BUT IS PROGGED TO REMAIN SOUTH OF THE AREA
IMPACTING THE SOUTHERN PLAINS. AS THE CENTRAL PLAINS AREA REMAINS
WITHIN A LARGER SCALE MID/UPPER TROUGH...MORE SEASONABLE HIGHS ARE
ANTICIPATED WITH VALUES IN THE LOW/MID 40S MON-TUE. SHORTWAVE
RIDGING IS PROGGED TO RETURN TOWARD MIDWEEK AND THE H85 THERMAL RIDGE
SHOULD ALLOW TEMPERATURES TO RETURN TO ABOVE NORMAL VALUES IN THE
50S. ANOTHER FAST MOVING CLIPPER SYSTEM MAY BRING A SURGE OF
CANADIAN AIR LATER IN THE WEEK BUT TIMING UNCERTAINTY REMAINS AND
RELUCTANT TO LOWER HIGHS ON THURSDAY AND MAINTAINED VALUES IN THE 50S.
MCGUIRE
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 48 36 53 47 / 0 0 40 60
HUTCHINSON 48 35 52 44 / 0 0 40 60
NEWTON 47 35 52 47 / 0 0 40 60
ELDORADO 47 35 52 49 / 0 0 40 60
WINFIELD-KWLD 48 34 53 50 / 0 0 40 60
RUSSELL 48 34 51 37 / 0 0 30 60
GREAT BEND 49 37 51 37 / 0 0 30 50
SALINA 46 36 54 43 / 0 0 30 60
MCPHERSON 47 37 52 44 / 0 0 30 60
COFFEYVILLE 47 31 55 49 / 0 0 40 70
CHANUTE 46 30 55 48 / 0 0 40 70
IOLA 46 30 55 47 / 0 0 30 70
PARSONS-KPPF 47 31 54 49 / 0 0 40 70
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1006 AM CST FRI FEB 8 2013
.UPDATE...
STRATUS AND PESKY DENSE FOG CONTINUE TO PLAGUE MOST OF CENTRAL AND
SOUTH CENTRAL KANSAS AT THIS TIME. THIS AREA OF FOG/STRATUS IS
GRADUALLY DRIFTING SW...WITH THE FIRST 30 MILES OF THE LEADING EDGE
OF THE STRATUS WHERE THE DENSE FOG IS LOCATED. VSBYS HAVE BEEN
AVERAGING 1/4 TO 1/2 MILE ALONG THIS LEADING EDGE. PLAN ON HANDLING
THIS WITH A SHORT TERM NOWCAST DUE TO THE TRANSIENT NATURE OF THE
FOG. SHORT RANGE RUC MODEL IS VERY PESSIMISTIC IN LIFTING/BURNING
THIS FOG FOR OFF UNTIL AFTER 18-19Z. SO HAVE EXTENDED THE DURATION
OF THE FOG/STRATUS UNTIL THEN. THINK THIS DECK WILL BURN OFF SOME
FROM THE EDGES...BEFORE BEGINNING TO LIFT BACK TO THE NORTH LATE
THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 510 AM CST FRI FEB 8 2013/
AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MAIN HAZARDS: LIFR/IFR CEILINGS AND VISIBILITIES THIS MORNING.
STRATUS SHIELD CONTINUES TO MOVE SOUTHWESTWARD ACROSS EASTERN KS
EARLY THIS MORNING. THE HRRR 3KM AND RUC13 SEEM TO HAVE A BETTER
HANDLE ON THE MORE MOIST BOUNDARY LAYER AIR. LIFR CIGS/VSBYS WILL
REMAIN LIKELY FOR MUCH OF THE MORNING ON THE SOUTHWESTERN FRINGES
OF THIS STRATUS SHIELD...AFFECTING RSL...SLN...HUT...AND ICT. CNU
SHOULD STAY MAINLY AT LOW END OF MVFR RANGE. DIURNAL
HEATING/MIXING SHOULD ALLOW STRATUS TO ERODE MIDDAY INTO THIS
AFTERNOON AND WILL HAVE CNU CLEARING THE LAST ~21Z.
JMC
PREV DISCUSSION... /ISSUED 250 AM CST FRI FEB 8 2013/
DISCUSSION...
THE PRIMARY FORECAST CONCERN WILL BE THE STORM SYSTEM EXPECTED TO
IMPACT THE AREA OVER THE WEEKEND BRINGING THE POSSIBILITY FOR SOME
HAIL SATURDAY NIGHT. CURRENTLY THIS STORM SYSTEM WAS DIGGING INTO
NORTHERN CALIFORNIA WHILE A MID/UPPER LEVEL RIDGE WAS TRANSLATING
EASTWARD OUT OF THE ROCKIES.
TODAY-TONIGHT...AT THE SURFACE...AN AREA OF LOW CLOUDS AND PATCHY
FOG WERE BACKING ACROSS THE FORECAST AREA EARLY THIS MORNING. SINCE
MANY OF THE SHORT-TERM MODELS HAD TROUBLE INITIALIZING THIS
ACTIVITY...UNCERTAINTY IN HOW QUICK IT MIXES OUT OR HOW FAR IT ADVECTS
WEST WILL LEAD TO A LOW CONFIDENCE TEMPERATURE FORECAST
TODAY...ESPECIALLY EAST OF THE KANSAS TURNPIKE WHERE STRATUS MAY
LINGER INTO THE AFTERNOON HOURS. TRENDED HIGHS LOWER EAST OF THE KTA
WHERE HIGHS MAY STRUGGLE TO CLIMB OUT OF THE 40S. FURTHER
WEST...WITH GREATER CHANCES FOR MORE PROLONGED INSOLATION/BREEZY
SOUTHERLY WINDS HIGHS MAY REACH THE MID 50S. EXTENSIVE MID AND UPPER
LEVEL CLOUDS ARE EXPECTED TO SPREAD OVER THE AREA LATE TONIGHT
WITHIN DIFFLUENT MID/UPPER FLOW DOWNSTREAM OF THE APPROACHING STORM
SYSTEM AND WITH THE EXPECTED SOUTHERLY WINDS...MILD LOWS ARE
ANTICIPATED WITH VALUES REMAINING IN THE MID/UPPER 30S ACROSS MUCH OF
THE AREA.
SATURDAY-SUNDAY...LOW LEVEL MOISTURE WILL SURGE NORTH DURING THE DAY
ON SATURDAY WHILE THE MORE ROBUST MOISTURE TRANSPORT/MUCAPE IS
PROGGED TO ARRIVE SAT NIGHT. WILL MAINTAIN MID POPS SAT AFTERNOON
WHILE HIGHER PROBABILITIES SHOULD ARRIVE AHEAD OF THE DRYLINE
SATURDAY NIGHT. THIS DRYLINE IS PROGGED TO SWEEP EAST ACROSS THE
AREA REACHING THE FLINT HILLS AREA BY AROUND 12Z SAT. THIS SHOULD
BRING A RAPID DEMISE TO ANY LINGERING SHOWER ACTIVITY WHILE WESTERLY
WINDS WITHIN THE DRY SECTOR SHOULD RESULT IN ANOTHER MILD DAY WITH
HIGHS RANGING FROM THE UPPER 40S NEAR KRSL TO THE MID 60S OVER
EXTREME SOUTHEAST KANSAS. ANY PRECIPITATION ON THE WESTERN/SOUTHWEST
PERIPHERY OF THE STORM SYSTEM IS EXPECTED TO REMAIN NORTH AND WEST
OF THE FORECAST AREA ON SUNDAY BUT CLOUDS MAY IMPACT FORECAST HIGHS
ACROSS THE I-70 CORRIDOR.
MONDAY-THURSDAY...ANOTHER STORM SYSTEM WILL ARRIVE ON THE HEELS OF
THE WEEKEND STORM BUT IS PROGGED TO REMAIN SOUTH OF THE AREA
IMPACTING THE SOUTHERN PLAINS. AS THE CENTRAL PLAINS AREA REMAINS
WITHIN A LARGER SCALE MID/UPPER TROUGH...MORE SEASONABLE HIGHS ARE
ANTICIPATED WITH VALUES IN THE LOW/MID 40S MON-TUE. SHORTWAVE
RIDGING IS PROGGED TO RETURN TOWARD MIDWEEK AND THE H85 THERMAL RIDGE
SHOULD ALLOW TEMPERATURES TO RETURN TO ABOVE NORMAL VALUES IN THE
50S. ANOTHER FAST MOVING CLIPPER SYSTEM MAY BRING A SURGE OF
CANADIAN AIR LATER IN THE WEEK BUT TIMING UNCERTAINTY REMAINS AND
RELUCTANT TO LOWER HIGHS ON THURSDAY AND MAINTAINED VALUES IN THE 50S.
MCGUIRE
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 52 36 53 47 / 0 0 40 60
HUTCHINSON 52 35 52 44 / 0 0 40 60
NEWTON 50 35 52 47 / 0 0 40 60
ELDORADO 50 35 52 49 / 0 0 40 60
WINFIELD-KWLD 53 34 53 50 / 0 0 40 60
RUSSELL 54 34 51 37 / 0 0 30 60
GREAT BEND 55 37 51 37 / 0 0 30 50
SALINA 49 36 54 43 / 0 0 30 60
MCPHERSON 51 37 52 44 / 0 0 30 60
COFFEYVILLE 47 31 55 49 / 0 0 40 70
CHANUTE 48 30 55 48 / 0 0 40 70
IOLA 47 30 55 47 / 0 0 30 70
PARSONS-KPPF 47 31 54 49 / 0 0 40 70
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
911 AM CST FRI FEB 8 2013
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 911 AM CST FRI FEB 8 2013
THE 08.12Z 250 HPA RAOB SYNOPTIC MAP SHOWED A CYCLONICALLY CURVED JET
LOCATED ACROSS THE WESTERN UNITED STATES. ANOTHER JET WAS LOCATED ACROSS
THE DEEP SOUTH. FINALLY, THE STRONGEST JET (130 KT) WAS LOCATED ACROSS
THE NORTHEASTERN UNITED STATES OF AMERICA. AT 500 HPA, A 540 DM CYCLONE
WAS LOCATED NEAR KSFO. SHORTWAVE RIDGING WAS LOCATED ACROSS THE ROCKIES.
A FEW MORE TROFS WERE LOCATED FARTHER DOWNSTREAM. AT 700 HPA, A VERY
DRY AND A BIT WARMER AIRMASS HAS SPREAD OVER WESTERN WESTERN KANSAS.
COLDER AIR ASSOCIATED WITH THE AFOREMENTIONED CYCLONE WAS LOCATED FARTHER
WEST WITH VALUES LESS THAN -10 DEG C. AT 850 HPA, THERE WAS WARM AIR
ADVECTION, PARTICULARLY ACROSS THE NORTHERN PLAINS. AT THE SFC, A STATIONARY
FRONT WAS LOCATED ACROSS THE LEE OF THE NORTHERN PLAINS. A COLD FRONT
WAS LOCATED ACROSS WESTERN ARIZONA. A FEW MORE FRONTAL SYSTEMS WERE
LOCATED ACROSS THE EASTERN U.S.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 240 AM CST FRI FEB 8 2013
A MID TO UPPER LEVEL RIDGE OF HIGH PRESSURE WILL SLIDE ACROSS THE
PLAINS TODAY AS A MID TO UPPER LEVEL LOW DIGS INTO THE WESTERN
CONUS. AN UPPER LEVEL JET ACCOMPANYING THIS LOW WILL EXTEND FROM THE
DESERT SOUTHWEST INTO THE SOUTHERN ROCKIES. TOWARDS THE SURFACE,
HIGH PRESSURE WILL BE LOCATED SOUTHEAST OF THE FORECAST AREA WITH
LEE TROUGHING INTENSIFYING ACROSS EASTERN COLORADO. THIS WILL BRING
SOUTHERLY WINDS TO WESTERN KANSAS TODAY THROUGH TONIGHT. WINDY
CONDITIONS ARE EXPECTED THIS AFTERNOON AS THE PRESSURE GRADIENT
TIGHTENS AND THE ATMOSPHERE MIXES. THE STRONGEST WINDS WILL BE FOUND
ACROSS FAR WESTERN KANSAS WHERE SUSTAINED WINDS OF 20 TO 30 MPH WILL
BE POSSIBLE WITH HIGHER GUSTS. THIS WILL BE CLOSE TO WIND ADVISORY
CRITERIA BUT HAVE REFRAINED FROM ISSUING ONE DUE TO IT BEING A LOW
END EVENT AT BEST. ONLY A FEW HIGH CLOUDS WILL BE PRESENT TODAY WITH
HIGHS IN THE MID TO UPPER 50S. BREEZY SOUTHERLY WINDS CONTINUE
TONIGHT AS THE AFOREMENTIONED LOW MOVES CLOSER TO THE HIGH PLAINS.
MID CLOUDS MAY INCREASE IN COVERAGE ACROSS SOUTH CENTRAL KANSAS AS
THE NIGHT PROGRESS WITH PARTLY CLOUDY SKIES AND DRY CONDITIONS
EXPECTED ELSEWHERE. AS FOR TEMPERATURES TONIGHT, LOWS ARE FORECAST
TO BE IN THE 30S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 316 AM CST FRI FEB 8 2013
THE 00Z FRIDAY GFS AND NAM REMAINS FAIRLY CONSISTENT WITH PREVIOUS
RUNS IN DEEPENING AN AREA OF LOW PRESSURE AT THE SURFACE ACROSS
EASTERN COLORADO ON SATURDAY AS AN UPPER LEVEL LOW MOVES EAST
TOWARDS THE CENTRAL ROCKIES. STRONG SOUTHERLY WINDS DEVELOPING AHEAD
OF THIS SURFACE LOW WILL DRAW MORE HUMID AIR IN THE SURFACE-850MB
LEVEL ACROSS MUCH OF WESTERN KANSAS ON SATURDAY AS A DRYLINE
DEVELOPS NEAR THE COLORADO BORDER. 00Z NAM BUFR SOUNDING DOES
SUGGEST THIS MOISTURE WILL BE AROUND 1KM DEEP BY SATURDAY AFTERNOON,
ESPECIALLY ACROSS SOUTH CENTRAL KANSAS. GIVEN THE IMPROVING LOW
LEVEL MOISTURE ALONG WITH SOME 925-850MB WARM AIR ADVECTION
DEVELOPING DURING THE DAY WILL RETAIN A MENTION OF LIGHT
PRECIPITATION BEING POSSIBLE SATURDAY AFTERNOON. CONVECTION CHANCES
SATURDAY AFTERNOON CURRENTLY APPEARS MORE FAVORABLE NEAR THE
COLORADO BORDER BASED ON LOCATION OF DEVELOPING DRYLINE, LOCATION OF
AN UPPER LEVEL JET, 0-6KM SHEAR GREATER THAN +50KTS AND MUCAPE CAPES
OF 500J/KG OR LESS.
850MB WINDS AT 18Z SATURDAY AND 00Z SUNDAY ARE FORECAST TO BE AROUND
40KTS. MIXED LAYER WINDS FROM THE NAM AND GFS AT 18Z SATURDAY AND
00Z SUNDAY RANGE FROM 30 TO 35KTS. SURFACE WINDS NEAR WIND
ADVISORY CRITERIA WILL BE POSSIBLE, ESPECIALLY WEST OF THE DRYLINE
WHERE A DEEPER MIXING DEPTH IS ANTICIPATED. DEWPOINTS WEST OF THE
DRYLINE STILL FORECAST TO FALL BACK INTO THE TEENS SATURDAY
AFTERNOON, HOWEVER GIVEN THE FURTHER WEST PLACEMENT OF THE DRYLINE
IT CURRENTLY APPEARS THESE LOW DEWPOINTS WILL BE MAINLY WEST OF
THE COLORADO BORDER. STILL ELEVATED FIRE DANGER LEVELS WILL BE
POSSIBLE FOR A FEW HOURS IN HAMILTON, STANTON AND MORTON COUNTIES.
ON SATURDAY NIGHT AN UPPER LEVEL TROUGH WILL CROSS THE CENTRAL
PLAINS AND A COLD FRONT WILL MOVE SOUTHEAST ACROSS WESTERN KANSAS.
PRECIPITATION WILL END FROM WEST TO EAST AS THE UPPER WAVE PASSES.
BEHIND THE COLD FRONT...GUSTY NORTHWEST WINDS ARE STILL
ANTICIPATED SO DESPITE CLEARING SKIES, COLD AIR ADVECTION, AND
LOWER DEWPOINTS RETURNING TO WESTERN KANSAS WILL FAVOR OVERNIGHT
LOWS SEVERAL DEGREES WARMER THAN THE 00Z GUIDANCE.
THE COLD FRONT WILL STALL OUT ACROSS NORTHERN TEXAS/SOUTHERN
OKLAHOMA ON SUNDAY. THIS FRONT WILL THEN REMAIN NEARLY STATIONARY
THROUGH EARLY NEXT WEEK AS ANOTHER UPPER LEVEL STORM SYSTEM MOVES
INTO THE SOUTHWEST UNITED STATES. MODEL SOUNDINGS, 850MB
TEMPERATURE TRENDS ALONG INCREASING MID TO HIGH LEVEL CLOUD COVER
EARLY NEXT WEEK CONTINUES TO SUPPORT HIGHS BOTH MONDAY AND TUESDAY
BEING ONLY IN THE 40S. THE BETTER OPPORTUNITY FOR PRECIPITATION
EARLY NEXT WEEK CURRENTLY APPEARS TO BE SOUTH OF THE OKLAHOMA
BORDER NEAR THE SURFACE BOUNDARY AS THE NEXT UPPER LEVEL SYSTEM
MOVES OUT OF THE ROCKIES AND ACROSS THE SOUTHERN PLAINS.
TEMPERATURE WILL THEN BEGIN TO CLIMB BACK INTO THE 50S MID WEEK AS
MID LEVEL WINDS BACK MORE TO THE NORTHWEST AND DOWNSLOPE FLOW BEGINS
TO IMPROVE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 517 AM CST FRI FEB 8 2013
BOTH THE 06Z NAM AND 08Z HRRR WERE IN GOOD AGREEMENT IN MOVING A
SURFACE BOUNDARY TO NEAR HAYS BY 12Z WHERE IT WILL THEN BECOME
STATIONARY THROUGH 15Z. BEHIND THIS BOUNDARY WIDESPREAD STATUS
ALONG WITH AREAS OF FOG WAS OBSERVED VIA SATELLITE AND SURFACE
OBSERVATIONS. BOTH MODELS KEEPS THIS STATUS AND FOG EAST OF HAYS
THROUGH THE EARLY MORNING HOURS, HOWEVER GIVEN HOW CLOSE THIS
STATUS WILL BE EARLY THIS MORNING WILL INSERT A BRIEF PERIOD OF
SCATTERED LIFR CLOUDS BETWEEN 12Z AND 15Z. AFTER 15Z THIS SURFACE
BOUNDARY WILL MOVE BACK NORTHEAST YIELDING VFR CONDITIONS. WINDS
AT LESS THAN 10KTS AT 12Z ACROSS ALL OF WESTERN AND NORTH CENTRAL
KANSAS WILL INCREASE TO NEAR 20KTS BY AROUND 18Z.
&&
.FIRE WEATHER...
ISSUED AT 316 AM CST FRI FEB 8 2013
GUSTY SOUTH SOUTHWEST WINDS OF 25 TO NEAR 30 MPH ARE EXPECTED ACROSS
FAR WESTERN KANSAS ON SATURDAY. IN ADDITION TO THESE GUSTY
WINDS...AFTERNOON RELATIVE HUMIDITIES ARE EXPECTED TO FALL BACK
INTO 20 TO 25 PERCENT RANGE. THIS WILL RESULT IN ELEVATED FIRE
WEATHER CONDITIONS FOR SEVERAL HOURS SATURDAY AFTERNOON ACROSS
PORTIONS OF HAMILTON, STANTON, AND MORTON COUNTIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 56 35 54 35 / 0 0 30 40
GCK 56 35 55 32 / 0 0 30 30
EHA 57 32 59 32 / 0 0 10 20
LBL 57 34 57 32 / 0 0 20 30
HYS 55 35 53 35 / 0 0 30 60
P28 56 38 51 42 / 0 0 40 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...HOVORKA_42
LONG TERM...BURGERT
AVIATION...BURGERT
FIRE WEATHER...BURGERT
AREA FORECAST DISCUSSION
NWS TOPEKA KS
525 AM CST FRI FEB 8 2013
...UPDATE TO AVIATION...
.DISCUSSION...
STRONG MID-UPPER LEVEL SUBSIDENCE WAS OCCURRING OVER THE CENTRAL
PLAINS IN THE OVERNIGHT HOURS BEHIND THURSDAYS SHORTWAVE. THE NEXT
UPPER SYSTEM WAS DIVING SOUTHEAST ALONG THE CALIFORNIA COAST WITH
CIRRUS PUSHING NORTHEAST OUT OF THE DESERT SOUTHWEST. NARROW
SURFACE HIGH PRESSURE WAS STRETCHED NORTH TO SOUTH FROM WESTERN
MINNESOTA TO CENTRAL KANSAS AT 08Z WITH STRATUS DECK NEAR ITS AXIS
AND SPREADING SOUTHWEST THROUGH EASTERN KANSAS. KOAX SOUNDING
SUGGESTS THE STRATUS IS QUIET SHALLOW AND A FEW HOLES IN UPSTREAM
STATES ARE EVIDENT VIA 11-3.9 MICRON SATELLITE PRODUCT. SOME FOG
HAS DEVELOPED IN NEBRASKA ALONG THE STRATUS DECK EDGE...AND SOME
MAY YET FORM SOUTH INTO KANSAS. WILL MONITOR LATEST TRENDS FOR ANY
INCLUSION.
MODELS CONTINUE TO STRUGGLE WITH THE STRATUS...WITH ONLY THE RAPID
UPDATE MODELS HAVING A CLUE. THEIR TRACK RECORD WITH SUCH FEATURES
IS NOT GREAT...WITH THIS FORECASTER EXPERIENCING A WET/COOL BIAS
FROM THE RAP ON MANY EVENTS. RECENT RUNS OF IT AND THE HRRR SUGGEST
CLOUDY CONDITIONS WILL INTO THE AFTERNOON HOURS. THE RIDGE AXIS MAKE
SLOW EASTWARD PROGRESS TODAY...WITH EAST TO SOUTHEAST WINDS
DEVELOPING...AND DOES NOT BODE WELL FOR A FAST CLEARING...BUT IF THE
HOLES CAN BE MAINTAINED THE PEAKS OF INSOLATION WOULD HELP BURN THE
STRATUS OFF. WILL KEEP SIGNIFICANT CLOUDS IN PLACE THROUGH LATE
MORNING AND TAKE A FEW DEGREES OF HIGH TEMPERATURES...BUT THIS IS A
LOW CONFIDENCE FORECAST FOR THESE ELEMENTS. INCREASING SOUTH WINDS
AND THICKENING HIGH CLOUDS SHOULD KEEP TEMPS IN THE LOWER 30S FOR
THE BULK OF THE AREA.
MOISTENING PROCESS AHEAD OF THE UPSTREAM LOW BRINGS BACK TO WELL
ABOVE NORMAL LEVELS BY SATURDAY AFTERNOON...WITH MEAGER LOW-MID
LEVEL WARM AIR ADVECTION PERHAPS LEADING TO ISOLATED TO SCATTERED
PRECIP BREAKING OUT. INSTABILITY AND FORCING INCREASE SATURDAY NIGHT
AS THE UPPER ENTERS THE CENTRAL PLAINS. MID LEVEL LAPSE RATES NEAR
THE 8C/KM RANGE WITH A BIT OF ELEVATED CAPE RESULTING...BUT GOOD
1-6KM SHEAR APPEARS TO COME WITH THE DRY SLOT. MODELS NOT TERRIBLY
STRONG WITH QPFS AND OVERALL COVERAGE OF PRECIP IS SOMEWHAT IN
QUESTION AS THIS POINT. WILL KEEP POPS IN THE LIKELY RANGE AT THIS
RANGE.
PRECIP STILL ON TRACK TO RAPIDLY EXIT SUNDAY AS WEST-SOUTHWEST FLOW
DEEPENS THROUGH COLUMN. MAIN CONCERN FOR THIS PERIOD APPEARS TO BE
WINDS AS SOME SOLUTIONS MIX SURFACE PARCELS WELL INTO THE
MID-TROPOSPHERE IN THE AFTERNOON AS STRONG PRESSURE RISES TAKE
PLACE. COLD AIR ADVECTION IN THE LATE DAY MAY KEEP TEMPS STEADY TO
FALLING IN THE NORTHWEST.
NEXT TROF TO ROTATE SOUTHEAST INTO THE SOUTHERN PLAINS IN MONDAY
NIGHT TO TUESDAY NIGHT PERIODS WITH WESTERLY FLOW DOMINATING MUCH OF
THE COLUMN. THIS SHOULD KEEP TEMPS IN THE NEAR TO ABOVE NORMAL RANGE
INTO THE MID WEEK. MODELS DO BEGIN TO DIVERGE WITH SUBSEQUENT
NORTHWEST FLOW WAVES BY LATE WEEK HOWEVER.
65
&&
.AVIATION...
THIN LAYER OF PRIMARILY MVFR STRATUS COVERS NORTHEAST KANSAS..SOME
IFR CIGS WILL PREVAIL IN THE MHK TERMINAL BEFORE RISING BACK TO
MVFR LEVELS. THE LOW LEVEL MOISTURE LAYER IS SHALLOW AND WITH SOME
MIXING THIS AFTERNOON EXPECT THE MVFR CIGS TO BREAK UP WITH VFR
CONDITIONS BY 21Z. WINDS WILL VEER FROMT HE NORTHEAST TO THE
SOUTHEAST BY LATE AFTERNOON. RAP MODEL FORECAST SOUNDINGS DOING
THE BEST JOB OF DEPICTING THE LOW LEVEL MOISTURE TODAY.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
521 AM CST FRI FEB 8 2013
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 240 AM CST FRI FEB 8 2013
A MID TO UPPER LEVEL RIDGE OF HIGH PRESSURE WILL SLIDE ACROSS THE
PLAINS TODAY AS A MID TO UPPER LEVEL LOW DIGS INTO THE WESTERN
CONUS. AN UPPER LEVEL JET ACCOMPANYING THIS LOW WILL EXTEND FROM THE
DESERT SOUTHWEST INTO THE SOUTHERN ROCKIES. TOWARDS THE SURFACE,
HIGH PRESSURE WILL BE LOCATED SOUTHEAST OF THE FORECAST AREA WITH
LEE TROUGHING INTENSIFYING ACROSS EASTERN COLORADO. THIS WILL BRING
SOUTHERLY WINDS TO WESTERN KANSAS TODAY THROUGH TONIGHT. WINDY
CONDITIONS ARE EXPECTED THIS AFTERNOON AS THE PRESSURE GRADIENT
TIGHTENS AND THE ATMOSPHERE MIXES. THE STRONGEST WINDS WILL BE FOUND
ACROSS FAR WESTERN KANSAS WHERE SUSTAINED WINDS OF 20 TO 30 MPH WILL
BE POSSIBLE WITH HIGHER GUSTS. THIS WILL BE CLOSE TO WIND ADVISORY
CRITERIA BUT HAVE REFRAINED FROM ISSUING ONE DUE TO IT BEING A LOW
END EVENT AT BEST. ONLY A FEW HIGH CLOUDS WILL BE PRESENT TODAY WITH
HIGHS IN THE MID TO UPPER 50S. BREEZY SOUTHERLY WINDS CONTINUE
TONIGHT AS THE AFOREMENTIONED LOW MOVES CLOSER TO THE HIGH PLAINS.
MID CLOUDS MAY INCREASE IN COVERAGE ACROSS SOUTH CENTRAL KANSAS AS
THE NIGHT PROGRESS WITH PARTLY CLOUDY SKIES AND DRY CONDITIONS
EXPECTED ELSEWHERE. AS FOR TEMPERATURES TONIGHT, LOWS ARE FORECASTED
TO BE IN THE 30S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 316 AM CST FRI FEB 8 2013
THE 00Z FRIDAY GFS AND NAM REMAINS FAIRLY CONSISTENT WITH PREVIOUS
RUNS IN DEEPENING AN AREA OF LOW PRESSURE AT THE SURFACE ACROSS
EASTERN COLORADO ON SATURDAY AS AN UPPER LEVEL LOW MOVES EAST
TOWARDS THE CENTRAL ROCKIES. STRONG SOUTHERLY WINDS DEVELOPING AHEAD
OF THIS SURFACE LOW WILL DRAW MORE HUMID AIR IN THE SURFACE-850MB
LEVEL ACROSS MUCH OF WESTERN KANSAS ON SATURDAY AS A DRYLINE
DEVELOPS NEAR THE COLORADO BORDER. 00Z NAM BUFR SOUNDING DOES
SUGGEST THIS MOISTURE WILL BE AROUND 1KM DEEP BY SATURDAY AFTERNOON,
ESPECIALLY ACROSS SOUTH CENTRAL KANSAS. GIVEN THE IMPROVING LOW
LEVEL MOISTURE ALONG WITH SOME 925-850MB WARM AIR ADVECTION
DEVELOPING DURING THE DAY WILL RETAIN A MENTION OF LIGHT
PRECIPITATION BEING POSSIBLE SATURDAY AFTERNOON. CONVECTION CHANCES
SATURDAY AFTERNOON CURRENTLY APPEARS MORE FAVORABLE NEAR THE
COLORADO BORDER BASED ON LOCATION OF DEVELOPING DRYLINE, LOCATION OF
AN UPPER LEVEL JET, 0-6KM SHEAR GREATER THAN +50KTS AND MUCAPE CAPES
OF 500J/KG OR LESS.
850MB WINDS AT 18Z SATURDAY AND 00Z SUNDAY ARE FORECAST TO BE AROUND
40KTS. MIXED LAYER WINDS FROM THE NAM AND GFS AT 18Z SATURDAY AND
00Z SUNDAY RANGE FROM 30 TO 35KTS. SURFACE WINDS NEAR WIND
ADVISORY CRITERIA WILL BE POSSIBLE, ESPECIALLY WEST OF THE DRYLINE
WHERE A DEEPER MIXING DEPTH IS ANTICIPATED. DEWPOINTS WEST OF THE
DRYLINE STILL FORECAST TO FALL BACK INTO THE TEENS SATURDAY
AFTERNOON, HOWEVER GIVEN THE FURTHER WEST PLACEMENT OF THE DRYLINE
IT CURRENTLY APPEARS THESE LOW DEWPOINTS WILL BE MAINLY WEST OF
THE COLORADO BORDER. STILL ELEVATED FIRE DANGER LEVELS WILL BE
POSSIBLE FOR A FEW HOURS IN HAMILTON, STANTON AND MORTON COUNTIES.
ON SATURDAY NIGHT AN UPPER LEVEL TROUGH WILL CROSS THE CENTRAL
PLAINS AND A COLD FRONT WILL MOVE SOUTHEAST ACROSS WESTERN KANSAS.
PRECIPITATION WILL END FROM WEST TO EAST AS THE UPPER WAVE PASSES.
BEHIND THE COLD FRONT...GUSTY NORTHWEST WINDS ARE STILL
ANTICIPATED SO DESPITE CLEARING SKIES, COLD AIR ADVECTION, AND
LOWER DEWPOINTS RETURNING TO WESTERN KANSAS WILL FAVOR OVERNIGHT
LOWS SEVERAL DEGREES WARMER THAN THE 00Z GUIDANCE.
THE COLD FRONT WILL STALL OUT ACROSS NORTHERN TEXAS/SOUTHERN
OKLAHOMA ON SUNDAY. THIS FRONT WILL THEN REMAIN NEARLY STATIONARY
THROUGH EARLY NEXT WEEK AS ANOTHER UPPER LEVEL STORM SYSTEM MOVES
INTO THE SOUTHWEST UNITED STATES. MODEL SOUNDINGS, 850MB
TEMPERATURE TRENDS ALONG INCREASING MID TO HIGH LEVEL CLOUD COVER
EARLY NEXT WEEK CONTINUES TO SUPPORT HIGHS BOTH MONDAY AND TUESDAY
BEING ONLY IN THE 40S. THE BETTER OPPORTUNITY FOR PRECIPITATION
EARLY NEXT WEEK CURRENTLY APPEARS TO BE SOUTH OF THE OKLAHOMA
BORDER NEAR THE SURFACE BOUNDARY AS THE NEXT UPPER LEVEL SYSTEM
MOVES OUT OF THE ROCKIES AND ACROSS THE SOUTHERN PLAINS.
TEMPERATURE WILL THEN BEGIN TO CLIMB BACK INTO THE 50S MID WEEK AS
MID LEVEL WINDS BACK MORE TO THE NORTHWEST AND DOWNSLOPE FLOW BEGINS
TO IMPROVE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 517 AM CST FRI FEB 8 2013
BOTH THE 06Z NAM AND 08Z HRRR WERE IN GOOD AGREEMENT IN MOVING A
SURFACE BOUNDARY TO NEAR HAYS BY 12Z WHERE IT WILL THEN BECOME
STATIONARY THROUGH 15Z. BEHIND THIS BOUNDARY WIDESPREAD STATUS
ALONG WITH AREAS OF FOG WAS OBSERVED VIA SATELLITE AND SURFACE
OBSERVATIONS. BOTH MODELS KEEPS THIS STATUS AND FOG EAST OF HAYS
THROUGH THE EARLY MORNING HOURS, HOWEVER GIVEN HOW CLOSE THIS
STATUS WILL BE EARLY THIS MORNING WILL INSERT A BRIEF PERIOD OF
SCATTERED LIFR CLOUDS BETWEEN 12Z AND 15Z. AFTER 15Z THIS SURFACE
BOUNDARY WILL MOVE BACK NORTHEAST YIELDING VFR CONDITIONS. WINDS
AT LESS THAN 10KTS AT 12Z ACROSS ALL OF WESTERN AND NORTH CENTRAL
KANSAS WILL INCREASE TO NEAR 20KTS BY AROUND 18Z.
&&
.FIRE WEATHER...
ISSUED AT 316 AM CST FRI FEB 8 2013
GUSTY SOUTH SOUTHWEST WINDS OF 25 TO NEAR 30 MPH ARE EXPECTED ACROSS
FAR WESTERN KANSAS ON SATURDAY. IN ADDITION TO THESE GUSTY
WINDS...AFTERNOON RELATIVE HUMIDITIES ARE EXPECTED TO FALL BACK
INTO 20 TO 25 PERCENT RANGE. THIS WILL RESULT IN ELEVATED FIRE
WEATHER CONDITIONS FOR SEVERAL HOURS SATURDAY AFTERNOON ACROSS
PORTIONS OF HAMILTON, STANTON, AND MORTON COUNTIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 56 35 54 35 / 0 0 30 40
GCK 56 35 55 32 / 0 0 30 30
EHA 57 32 59 32 / 0 0 10 20
LBL 57 34 57 32 / 0 0 20 30
HYS 55 35 53 35 / 0 0 30 60
P28 56 38 51 42 / 0 0 40 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HOVORKA_42
LONG TERM...BURGERT
AVIATION...BURGERT
FIRE WEATHER...BURGERT
AREA FORECAST DISCUSSION
NWS WICHITA KS
510 AM CST FRI FEB 8 2013
.AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MAIN HAZARDS: LIFR/IFR CEILINGS AND VISIBILITIES THIS MORNING.
STRATUS SHIELD CONTINUES TO MOVE SOUTHWESTWARD ACROSS EASTERN KS
EARLY THIS MORNING. THE HRRR 3KM AND RUC13 SEEM TO HAVE A BETTER
HANDLE ON THE MORE MOIST BOUNDARY LAYER AIR. LIFR CIGS/VSBYS WILL
REMAIN LIKELY FOR MUCH OF THE MORNING ON THE SOUTHWESTERN FRINGES
OF THIS STRATUS SHIELD...AFFECTING RSL...SLN...HUT...AND ICT. CNU
SHOULD STAY MAINLY AT LOW END OF MVFR RANGE. DIURNAL
HEATING/MIXING SHOULD ALLOW STRATUS TO ERODE MIDDAY INTO THIS
AFTERNOON AND WILL HAVE CNU CLEARING THE LAST ~21Z.
JMC
&&
.PREV DISCUSSION... /ISSUED 250 AM CST FRI FEB 8 2013/
DISCUSSION...
THE PRIMARY FORECAST CONCERN WILL BE THE STORM SYSTEM EXPECTED TO
IMPACT THE AREA OVER THE WEEKEND BRINGING THE POSSIBILITY FOR SOME
HAIL SATURDAY NIGHT. CURRENTLY THIS STORM SYSTEM WAS DIGGING INTO
NORTHERN CALIFORNIA WHILE A MID/UPPER LEVEL RIDGE WAS TRANSLATING
EASTWARD OUT OF THE ROCKIES.
TODAY-TONIGHT...AT THE SURFACE...AN AREA OF LOW CLOUDS AND PATCHY
FOG WERE BACKING ACROSS THE FORECAST AREA EARLY THIS MORNING. SINCE
MANY OF THE SHORT-TERM MODELS HAD TROUBLE INITIALIZING THIS
ACTIVITY...UNCERTAINTY IN HOW QUICK IT MIXES OUT OR HOW FAR IT ADVECTS
WEST WILL LEAD TO A LOW CONFIDENCE TEMPERATURE FORECAST
TODAY...ESPECIALLY EAST OF THE KANSAS TURNPIKE WHERE STRATUS MAY
LINGER INTO THE AFTERNOON HOURS. TRENDED HIGHS LOWER EAST OF THE KTA
WHERE HIGHS MAY STRUGGLE TO CLIMB OUT OF THE 40S. FURTHER
WEST...WITH GREATER CHANCES FOR MORE PROLONGED INSOLATION/BREEZY
SOUTHERLY WINDS HIGHS MAY REACH THE MID 50S. EXTENSIVE MID AND UPPER
LEVEL CLOUDS ARE EXPECTED TO SPREAD OVER THE AREA LATE TONIGHT
WITHIN DIFFLUENT MID/UPPER FLOW DOWNSTREAM OF THE APPROACHING STORM
SYSTEM AND WITH THE EXPECTED SOUTHERLY WINDS...MILD LOWS ARE
ANTICIPATED WITH VALUES REMAINING IN THE MID/UPPER 30S ACROSS MUCH OF
THE AREA.
SATURDAY-SUNDAY...LOW LEVEL MOISTURE WILL SURGE NORTH DURING THE DAY
ON SATURDAY WHILE THE MORE ROBUST MOISTURE TRANSPORT/MUCAPE IS
PROGGED TO ARRIVE SAT NIGHT. WILL MAINTAIN MID POPS SAT AFTERNOON
WHILE HIGHER PROBABILITIES SHOULD ARRIVE AHEAD OF THE DRYLINE
SATURDAY NIGHT. THIS DRYLINE IS PROGGED TO SWEEP EAST ACROSS THE
AREA REACHING THE FLINT HILLS AREA BY AROUND 12Z SAT. THIS SHOULD
BRING A RAPID DEMISE TO ANY LINGERING SHOWER ACTIVITY WHILE WESTERLY
WINDS WITHIN THE DRY SECTOR SHOULD RESULT IN ANOTHER MILD DAY WITH
HIGHS RANGING FROM THE UPPER 40S NEAR KRSL TO THE MID 60S OVER
EXTREME SOUTHEAST KANSAS. ANY PRECIPITATION ON THE WESTERN/SOUTHWEST
PERIPHERY OF THE STORM SYSTEM IS EXPECTED TO REMAIN NORTH AND WEST
OF THE FORECAST AREA ON SUNDAY BUT CLOUDS MAY IMPACT FORECAST HIGHS
ACROSS THE I-70 CORRIDOR.
MONDAY-THURSDAY...ANOTHER STORM SYSTEM WILL ARRIVE ON THE HEELS OF
THE WEEKEND STORM BUT IS PROGGED TO REMAIN SOUTH OF THE AREA
IMPACTING THE SOUTHERN PLAINS. AS THE CENTRAL PLAINS AREA REMAINS
WITHIN A LARGER SCALE MID/UPPER TROUGH...MORE SEASONABLE HIGHS ARE
ANTICIPATED WITH VALUES IN THE LOW/MID 40S MON-TUE. SHORTWAVE
RIDGING IS PROGGED TO RETURN TOWARD MIDWEEK AND THE H85 THERMAL RIDGE
SHOULD ALLOW TEMPERATURES TO RETURN TO ABOVE NORMAL VALUES IN THE
50S. ANOTHER FAST MOVING CLIPPER SYSTEM MAY BRING A SURGE OF
CANADIAN AIR LATER IN THE WEEK BUT TIMING UNCERTAINTY REMAINS AND
RELUCTANT TO LOWER HIGHS ON THURSDAY AND MAINTAINED VALUES IN THE 50S.
MCGUIRE
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 52 36 53 47 / 0 0 40 60
HUTCHINSON 52 35 52 44 / 0 0 40 60
NEWTON 50 35 52 47 / 0 0 40 60
ELDORADO 50 35 52 49 / 0 0 40 60
WINFIELD-KWLD 53 34 53 50 / 0 0 40 60
RUSSELL 54 34 51 37 / 0 0 30 60
GREAT BEND 55 37 51 37 / 0 0 30 50
SALINA 49 36 54 43 / 0 0 30 60
MCPHERSON 51 37 52 44 / 0 0 30 60
COFFEYVILLE 47 31 55 49 / 0 0 40 70
CHANUTE 48 30 55 48 / 0 0 40 70
IOLA 47 30 55 47 / 0 0 30 70
PARSONS-KPPF 47 31 54 49 / 0 0 40 70
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
313 AM CST FRI FEB 8 2013
.DISCUSSION...
STRONG MID-UPPER LEVEL SUBSIDENCE WAS OCCURRING OVER THE CENTRAL
PLAINS IN THE OVERNIGHT HOURS BEHIND THURSDAYS SHORTWAVE. THE NEXT
UPPER SYSTEM WAS DIVING SOUTHEAST ALONG THE CALIFORNIA COAST WITH
CIRRUS PUSHING NORTHEAST OUT OF THE DESERT SOUTHWEST. NARROW
SURFACE HIGH PRESSURE WAS STRETCHED NORTH TO SOUTH FROM WESTERN
MINNESOTA TO CENTRAL KANSAS AT 08Z WITH STRATUS DECK NEAR ITS AXIS
AND SPREADING SOUTHWEST THROUGH EASTERN KANSAS. KOAX SOUNDING
SUGGESTS THE STRATUS IS QUIET SHALLOW AND A FEW HOLES IN UPSTREAM
STATES ARE EVIDENT VIA 11-3.9 MICRON SATELLITE PRODUCT. SOME FOG
HAS DEVELOPED IN NEBRASKA ALONG THE STRATUS DECK EDGE...AND SOME
MAY YET FORM SOUTH INTO KANSAS. WILL MONITOR LATEST TRENDS FOR ANY
INCLUSION.
MODELS CONTINUE TO STRUGGLE WITH THE STRATUS...WITH ONLY THE RAPID
UPDATE MODELS HAVING A CLUE. THEIR TRACK RECORD WITH SUCH FEATURES
IS NOT GREAT...WITH THIS FORECASTER EXPERIENCING A WET/COOL BIAS
FROM THE RAP ON MANY EVENTS. RECENT RUNS OF IT AND THE HRRR SUGGEST
CLOUDY CONDITIONS WILL INTO THE AFTERNOON HOURS. THE RIDGE AXIS MAKE
SLOW EASTWARD PROGRESS TODAY...WITH EAST TO SOUTHEAST WINDS
DEVELOPING...AND DOES NOT BODE WELL FOR A FAST CLEARING...BUT IF THE
HOLES CAN BE MAINTAINED THE PEAKS OF INSOLATION WOULD HELP BURN THE
STRATUS OFF. WILL KEEP SIGNIFICANT CLOUDS IN PLACE THROUGH LATE
MORNING AND TAKE A FEW DEGREES OF HIGH TEMPERATURES...BUT THIS IS A
LOW CONFIDENCE FORECAST FOR THESE ELEMENTS. INCREASING SOUTH WINDS
AND THICKENING HIGH CLOUDS SHOULD KEEP TEMPS IN THE LOWER 30S FOR
THE BULK OF THE AREA.
MOISTENING PROCESS AHEAD OF THE UPSTREAM LOW BRINGS BACK TO WELL
ABOVE NORMAL LEVELS BY SATURDAY AFTERNOON...WITH MEAGER LOW-MID
LEVEL WARM AIR ADVECTION PERHAPS LEADING TO ISOLATED TO SCATTERED
PRECIP BREAKING OUT. INSTABILITY AND FORCING INCREASE SATURDAY NIGHT
AS THE UPPER ENTERS THE CENTRAL PLAINS. MID LEVEL LAPSE RATES NEAR
THE 8C/KM RANGE WITH A BIT OF ELEVATED CAPE RESULTING...BUT GOOD
1-6KM SHEAR APPEARS TO COME WITH THE DRY SLOT. MODELS NOT TERRIBLY
STRONG WITH QPFS AND OVERALL COVERAGE OF PRECIP IS SOMEWHAT IN
QUESTION AS THIS POINT. WILL KEEP POPS IN THE LIKELY RANGE AT THIS
RANGE.
PRECIP STILL ON TRACK TO RAPIDLY EXIT SUNDAY AS WEST-SOUTHWEST FLOW
DEEPENS THROUGH COLUMN. MAIN CONCERN FOR THIS PERIOD APPEARS TO BE
WINDS AS SOME SOLUTIONS MIX SURFACE PARCELS WELL INTO THE
MID-TROPOSPHERE IN THE AFTERNOON AS STRONG PRESSURE RISES TAKE
PLACE. COLD AIR ADVECTION IN THE LATE DAY MAY KEEP TEMPS STEADY TO
FALLING IN THE NORTHWEST.
NEXT TROF TO ROTATE SOUTHEAST INTO THE SOUTHERN PLAINS IN MONDAY
NIGHT TO TUESDAY NIGHT PERIODS WITH WESTERLY FLOW DOMINATING MUCH OF
THE COLUMN. THIS SHOULD KEEP TEMPS IN THE NEAR TO ABOVE NORMAL RANGE
INTO THE MID WEEK. MODELS DO BEGIN TO DIVERGE WITH SUBSEQUENT
NORTHWEST FLOW WAVES BY LATE WEEK HOWEVER.
65
&&
.AVIATION...
EXCEPT FOR THE RAP...MODELS SEEM TO HAVE LITTLE CLUE ABOUT THE
STRATUS. THINK THAT IT MAY BE HERE TO STAY FOR A WHILE WITH THE
CENTER OF THE SFC RIDGE PASSING TO THE NORTH CAUSING WINDS TO VEER
AROUND TO THE SOUTHEAST IN THE AFTERNOON. GIVEN THE EXPANSE OF THE
STRATUS TO THE EAST AND LIMITED MIXING DUE TO THE RIDGE...IT SEEMS
PLAUSIBLE THAT THE CLOUDS COULD HANG IN FOR MUCH OF FRIDAY. THE RAP
FORECAST SOUNDINGS SHOW THIS HAPPENING. THEREFORE THE FORECAST LEANS
ON PERSISTENCE UNTIL THE RIDGE AXIS PASSES EAST AND WINDS BECOME A
LITTLE MORE SOUTHERLY WHEN THERE COULD BE SOME MIXING. THINK CIGS
WILL REMAIN ABOVE 1 KFT. CONFIDENCE IN THE CIG FORECAST IS MARGINAL.
WOLTERS
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
250 AM CST FRI FEB 8 2013
.DISCUSSION...
THE PRIMARY FORECAST CONCERN WILL BE THE STORM SYSTEM EXPECTED TO
IMPACT THE AREA OVER THE WEEKEND BRINGING THE POSSIBILITY FOR SOME
HAIL SATURDAY NIGHT. CURRENTLY THIS STORM SYSTEM WAS DIGGING INTO
NORTHERN CALIFORNIA WHILE A MID/UPPER LEVEL RIDGE WAS TRANSLATING
EASTWARD OUT OF THE ROCKIES.
TODAY-TONIGHT...AT THE SURFACE...AN AREA OF LOW CLOUDS AND PATCHY
FOG WERE BACKING ACROSS THE FORECAST AREA EARLY THIS MORNING. SINCE
MANY OF THE SHORT-TERM MODELS HAD TROUBLE INITIALIZING THIS
ACTIVITY...UNCERTAINTY IN HOW QUICK IT MIXES OUT OR HOW FAR IT ADVECTS
WEST WILL LEAD TO A LOW CONFIDENCE TEMPERATURE FORECAST
TODAY...ESPECIALLY EAST OF THE KANSAS TURNPIKE WHERE STRATUS MAY
LINGER INTO THE AFTERNOON HOURS. TRENDED HIGHS LOWER EAST OF THE KTA
WHERE HIGHS MAY STRUGGLE TO CLIMB OUT OF THE 40S. FURTHER
WEST...WITH GREATER CHANCES FOR MORE PROLONGED INSOLATION/BREEZY
SOUTHERLY WINDS HIGHS MAY REACH THE MID 50S. EXTENSIVE MID AND UPPER
LEVEL CLOUDS ARE EXPECTED TO SPREAD OVER THE AREA LATE TONIGHT
WITHIN DIFFLUENT MID/UPPER FLOW DOWNSTREAM OF THE APPROACHING STORM
SYSTEM AND WITH THE EXPECTED SOUTHERLY WINDS...MILD LOWS ARE
ANTICIPATED WITH VALUES REMAINING IN THE MID/UPPER 30S ACROSS MUCH OF
THE AREA.
SATURDAY-SUNDAY...LOW LEVEL MOISTURE WILL SURGE NORTH DURING THE DAY
ON SATURDAY WHILE THE MORE ROBUST MOISTURE TRANSPORT/MUCAPE IS
PROGGED TO ARRIVE SAT NIGHT. WILL MAINTAIN MID POPS SAT AFTERNOON
WHILE HIGHER PROBABILITIES SHOULD ARRIVE AHEAD OF THE DRYLINE
SATURDAY NIGHT. THIS DRYLINE IS PROGGED TO SWEEP EAST ACROSS THE
AREA REACHING THE FLINT HILLS AREA BY AROUND 12Z SAT. THIS SHOULD
BRING A RAPID DEMISE TO ANY LINGERING SHOWER ACTIVITY WHILE WESTERLY
WINDS WITHIN THE DRY SECTOR SHOULD RESULT IN ANOTHER MILD DAY WITH
HIGHS RANGING FROM THE UPPER 40S NEAR KRSL TO THE MID 60S OVER
EXTREME SOUTHEAST KANSAS. ANY PRECIPITATION ON THE WESTERN/SOUTHWEST
PERIPHERY OF THE STORM SYSTEM IS EXPECTED TO REMAIN NORTH AND WEST
OF THE FORECAST AREA ON SUNDAY BUT CLOUDS MAY IMPACT FORECAST HIGHS
ACROSS THE I-70 CORRIDOR.
MONDAY-THURSDAY...ANOTHER STORM SYSTEM WILL ARRIVE ON THE HEELS OF
THE WEEKEND STORM BUT IS PROGGED TO REMAIN SOUTH OF THE AREA
IMPACTING THE SOUTHERN PLAINS. AS THE CENTRAL PLAINS AREA REMAINS
WITHIN A LARGER SCALE MID/UPPER TROUGH...MORE SEASONABLE HIGHS ARE
ANTICIPATED WITH VALUES IN THE LOW/MID 40S MON-TUE. SHORTWAVE
RIDGING IS PROGGED TO RETURN TOWARD MIDWEEK AND THE H85 THERMAL RIDGE
SHOULD ALLOW TEMPERATURES TO RETURN TO ABOVE NORMAL VALUES IN THE
50S. ANOTHER FAST MOVING CLIPPER SYSTEM MAY BRING A SURGE OF
CANADIAN AIR LATER IN THE WEEK BUT TIMING UNCERTAINTY REMAINS AND
RELUCTANT TO LOWER HIGHS ON THURSDAY AND MAINTAINED VALUES IN THE 50S.
MCGUIRE
&&
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
LOW CIGS WILL CONTINUE TO FILTER SOUTHWEST OVER THE EASTERN HALF
OF KS OVERNIGHT...AND LIKELY PERSIST THROUGH AT LEAST MID MORNING
FRIDAY...AS A SHALLOW COLD AIRMASS WEDGES SOUTH/SOUTHWEST. WESTERN
EXTENT OF LOW CIGS WILL BE TRICKY...BUT PER LATEST HRRR AND
RUC...THINKING WESTERN EXTENT SHOULD SET UP ALONG A LINE
EXTENDING FROM ROUGHLY KRSL-KHUT-KICT. CIGS SHOULD REMAIN MOSTLY
LOW MVFR...ALTHOUGH IFR WILL BE POSSIBLE...ESPECIALLY ON WESTERN
FRINGE (KRSL-KHUT-KICT) WHERE UPSLOPE AND DIURNAL COOLING
ENHANCEMENTS ARE MAXIMIZED. ADDITIONALLY...COULD BE LOOKING AT
PATCHY FOG LATE TONIGHT/EARLY FRIDAY...ESPECIALLY FOR
KRSL-KHUT-KICT. THINKING CIGS WILL BE SLUGGISH TO CLEAR FRIDAY
MORNING. WILL CONTINUE TO MONITOR TRENDS AND MAKE TIMELY
AMENDMENTS WHEN/WHERE NECESSARY.
ADK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 52 36 53 47 / 0 0 40 60
HUTCHINSON 52 35 52 44 / 0 0 40 60
NEWTON 50 35 52 47 / 0 0 40 60
ELDORADO 50 35 52 49 / 0 0 40 60
WINFIELD-KWLD 53 34 53 50 / 0 0 40 60
RUSSELL 54 34 51 37 / 0 0 30 60
GREAT BEND 55 37 51 37 / 0 0 30 50
SALINA 49 36 54 43 / 0 0 30 60
MCPHERSON 51 37 52 44 / 0 0 30 60
COFFEYVILLE 47 31 55 49 / 0 0 40 70
CHANUTE 48 30 55 48 / 0 0 40 70
IOLA 47 30 55 47 / 0 0 30 70
PARSONS-KPPF 47 31 54 49 / 0 0 40 70
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1144 PM CST THU FEB 7 2013
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
LOW CIGS WILL CONTINUE TO FILTER SOUTHWEST OVER THE EASTERN HALF
OF KS OVERNIGHT...AND LIKELY PERSIST THROUGH AT LEAST MID MORNING
FRIDAY...AS A SHALLOW COLD AIRMASS WEDGES SOUTH/SOUTHWEST. WESTERN
EXTENT OF LOW CIGS WILL BE TRICKY...BUT PER LATEST HRRR AND
RUC...THINKING WESTERN EXTENT SHOULD SET UP ALONG A LINE
EXTENDING FROM ROUGHLY KRSL-KHUT-KICT. CIGS SHOULD REMAIN MOSTLY
LOW MVFR...ALTHOUGH IFR WILL BE POSSIBLE...ESPECIALLY ON WESTERN
FRINGE (KRSL-KHUT-KICT) WHERE UPSLOPE AND DIURNAL COOLING
ENHANCEMENTS ARE MAXIMIZED. ADDITIONALLY...COULD BE LOOKING AT
PATCHY FOG LATE TONIGHT/EARLY FRIDAY...ESPECIALLY FOR
KRSL-KHUT-KICT. THINKING CIGS WILL BE SLUGGISH TO CLEAR FRIDAY
MORNING. WILL CONTINUE TO MONITOR TRENDS AND MAKE TIMELY
AMENDMENTS WHEN/WHERE NECESSARY.
ADK
&&
.PREV DISCUSSION... /ISSUED 1042 PM CST THU FEB 7 2013/
UPDATE...
LOW CLOUDS CONTINUE TO TREK SOUTHWESTWARD ACROSS EASTERN KS. THINK
THE LATEST RUC AND HRRR MODELS HAVE A GOOD FEEL FOR CURRENT
CONDITIONS...AND BRING THE LOW CLOUDS ALL THE WAY TO THE
I-135/HIGHWAY 14 CORRIDORS. HAVE ADJUSTED THE GRIDS/FORECAST TO
REFLECT THIS. STILL THINKING PATCHY FOG WILL BE POSSIBLE GENERALLY
WEST OF THE FLINT HILLS OVERNIGHT.
ADK
PREV DISCUSSION... /ISSUED 903 PM CST THU FEB 7 2013/
UPDATE...
SHORT-TERM GUIDANCE NOT HELPFUL THIS EVENING/OVERNIGHT REGARDING
LOW-LEVEL MOISTURE PROGS. CURRENT SWATH OF LOW CLOUDS APPROACHING
FROM THE NORTHEAST...ASSOCIATED WITH APPROACHING LOW-LEVEL COLD
ADVECTION...SHOULD MAKE IT INTO SOUTHEAST KS WITHIN THE NEXT FEW
HOURS. THINK LOW CLOUDS OVERNIGHT SHOULD REMAIN GENERALLY
ALONG/EAST OF THE FLINT HILLS...ALONG/EAST OF THE LOW-LEVEL RIDGE
AXIS. ADDITIONALLY...THINKING PATCHY FOG WILL BE POSSIBLE AFTER
MIDNIGHT GENERALLY ALONG/WEST OF THE FLINT HILLS...DUE TO
SLACKENING WINDS AND CLEAR SKIES AMIDST A NEWLY WET GROUND. BEST
CHANCES WILL LIKELY BE OVER CENTRAL/EAST-CENTRAL KS GENERALLY
NORTH OF HIGHWAY 50...WHERE LAST NIGHT`S RAINS WERE MOST
PLENTIFUL. NOT ANTICIPATING WIDESPREAD FOG...BUT PATCHY/SHALLOW
GROUND FOG FOR MAINLY LOW-LYING AREAS. SINCE TEMPERATURES WILL
LIKELY BE BELOW FREEZING...SLICK SPOTS ON ROADS/WALKWAYS COULD
DEVELOP IN FOGGY AREAS.
ADK
PREV DISCUSSION... /ISSUED 544 PM CST THU FEB 7 2013/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
FAIRLY QUIET VFR CONDITIONS EXPECTED FOR MUCH OF THE NEXT 24
HOURS. HOWEVER...COULD SEE SOME PATCHY AND SHALLOW GROUND FOG
LATE TONIGHT THROUGH EARLY FRIDAY MORNING ACROSS THE REGION...AS
HIGH PRESSURE SETTLES SOUTHEAST...ALLOWING FOR LIGHT WINDS AND
CLEAR SKIES OVER THE NEWLY WET GROUND. SINCE IT`LL LIKELY BE
SHALLOW AND PATCHY...PLAYED THE CONSERVATIVE ROUTE FOR NOW AND
ONLY WENT WITH 4SM BR ALL TAF SITES FROM ABOUT 11-15Z. WILL
CONTINUE TO ASSESS FOR 06Z TAF ISSUANCE.
ADK
PREV DISCUSSION... /ISSUED 313 PM CST THU FEB 7 2013/
DISCUSSION...
TONIGHT-FRI:
INITIAL CONCERN IS POTENTIAL FOR FREEZING GROUND FOG LATER TONIGHT...
ESPECIALLY IN THE MAXIMUM PRECIPITATION AXIS FROM ROUGHLY GBD TO
WEST OF EMP. LIGHT WINDS AND CLEAR SKIES WILL ALLOW TEMPERATURES
TO RADIATE INTO THE 20S IN THIS AREA. MODELS DO SHOW VERY DRY AIR
JUST OF THE DECK...SO NOT EXPECTED ANYTHING WIDESPREAD/DENSE AT
THIS TIME. THE MOIST GROUND MAY LIMIT MAX TEMPERATURES A FEW
DEGREES ON FRI...BUT ANTICIPATING 50S AREA WIDE.
FRI NIGHT-SUN:
ONE MORE COOL NIGHT ANTICIPATED AS RETURN FLOW APPEARS TO BE A
BIT SLOWER TO DEVELOP. BEST RETURN FLOW/MOISTURE WILL BE ON
SAT...WITH INCREASING CLOUDS/CHANCES OF PRECIPITATION DURING DAY.
AS TSA HINTED...RELATIVELY DRY AIR SAT AFTERNOON COULD CAUSE FAIR
AMOUNT OF EVAPORATIVE COOLING IF RAIN COMMENCES DURING THE DAY. BY
EVENING/OVERNIGHT...DEWPOINTS SHOULD PUSH WELL INTO THE
40S/50S...WITH GOOD CHANCE FOR RAIN SHOWERS/THUNDERSTORM. HAVE
UPPED MINIMUMS SAT NIGHT/SUN WITH MOST OF THE COLD AIR ONLY
REACHING CENTRAL KS BY DAYBREAK. LARGE DRY SLOT WILL BRING ABRUPT
END OF THE PRECIPITATION SUN MORNING. BASED ON LATEST GUIDANCE...
BELIEVE EVEN CENTRAL KS WILL ESCAPE THE WRAP AROUND PRECIPITATION
LATER SUN/SUN NIGHT.
MON-THU:
ECMWF CONTINUE TO BE VERY CONSISTENT WITH ITS PREVIOUS RUNS...
SUGGEST PRECIPITATION WILL REMAIN SOUTH OF THE AREA THROUGHOUT THE
PERIOD...AND GFS HAS COME AROUND TO THIS AS WELL. BOTH SUGGEST
TRAILING ENERGY IN LONG WAVE TROUGH WILL DEVELOP ANOTHER SURFACE
LOW ON COLD FRONT. WITH NEWER RUNS SHOWING FRONT GOING EVEN
FURTHER SOUTH...SO NORTHERN EDGE OF PRECIPITATION SHOULD REMAIN
SOUTH OF THE AREA. BOTH GFS/ECMWF 925 MILLIBAR MIXDOWN TEMPERATURES
SUGGEST TEMPERATURES IN AT LEAST THE UPPER 40S/LOWER 50S...BUT
WOULD NOT BE SURPRISED IF TEMPERATURES END UP WELL INTO THE 50S.
-HOWERTON
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE MAIN AVIATION FORECAST CONCERN WILL BE THE EXIT OF THE
PRECIPITATION...AND IFR/MVFR FLIGHT CONDITIONS. PRECIPITATION HAS
ENDED AT ALL TERMINALS EXCEPT KCNU AS OF 18Z. SKIES HAVE EITHER
CLEARED OR ARE CLEARING. HOWEVER...AT KCNU MVFR TO IFR CONDITIONS
ARE STILL POSSIBLE THROUGH THE REMAINDER OF THE DAY. VFR WILL
RETURN TO KCNU THIS AFTERNOON. THE SURFACE RIDGE AXIS WILL
TRAVERSE THE AREA OVERNIGHT CAUSING WINDS TO BE LIGHT AND VARIABLE
AND EVENTUALLY SWITCH AROUND TO THE SOUTH/SOUTHEAST. THE LIGHT AND
VARIABLE WINDS AND THE AMOUNT MOISTURE IN THE BOUNDARY LAYER MAKES
GROUND FOG A CONCERN FOR THE EARLY MORNING HOURS FRIDAY. HAVE
TRENDED THAT WAY WITH 4SM AND SCATTERED 1000FT CEILINGS. WILL NEED
TO WATCH THIS AND EDIT WITH LATER FORECASTS.
BILLINGS
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 28 53 35 52 / 0 0 0 40
HUTCHINSON 26 53 34 51 / 0 0 0 40
NEWTON 28 51 32 51 / 0 0 0 40
ELDORADO 28 52 33 51 / 0 0 0 40
WINFIELD-KWLD 29 53 35 52 / 0 0 0 40
RUSSELL 24 54 34 50 / 0 0 0 30
GREAT BEND 24 52 35 50 / 0 0 0 30
SALINA 26 51 34 53 / 0 0 0 30
MCPHERSON 26 52 34 51 / 0 0 0 30
COFFEYVILLE 30 53 35 54 / 0 0 0 40
CHANUTE 28 51 33 54 / 0 0 0 40
IOLA 28 50 33 54 / 0 0 0 30
PARSONS-KPPF 28 52 33 53 / 0 0 0 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1120 PM CST THU FEB 7 2013
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
EXCEPT FOR THE RAP...MODELS SEEM TO HAVE LITTLE CLUE ABOUT THE
STRATUS. THINK THAT IT MAY BE HERE TO STAY FOR A WHILE WITH THE
CENTER OF THE SFC RIDGE PASSING TO THE NORTH CAUSING WINDS TO VEER
AROUND TO THE SOUTHEAST IN THE AFTERNOON. GIVEN THE EXPANSE OF THE
STRATUS TO THE EAST AND LIMITED MIXING DUE TO THE RIDGE...IT SEEMS
PLAUSIBLE THAT THE CLOUDS COULD HANG IN FOR MUCH OF FRIDAY. THE RAP
FORECAST SOUNDINGS SHOW THIS HAPPENING. THEREFORE THE FORECAST LEANS
ON PERSISTENCE UNTIL THE RIDGE AXIS PASSES EAST AND WINDS BECOME A
LITTLE MORE SOUTHERLY WHEN THERE COULD BE SOME MIXING. THINK CIGS
WILL REMAIN ABOVE 1 KFT. CONFIDENCE IN THE CIG FORECAST IS MARGINAL.
WOLTERS
&&
.PREV DISCUSSION... /313 PM CST THU FEB 7 2013/
TONIGHT THROUGH FRIDAY...THE TAIL-END OF THE MORNING RAIN SHOWERS
WERE SKIMMING ACROSS EAST CENTRAL AND SOUTHEAST KANSAS THIS
AFTERNOON. NORTH-NORTHWESTERLY FLOW PREVAILED ACROSS THE REGION WITH
THE COLD FRONT HAVING PROGRESSED EAST OF THE CWA EARLIER TODAY.
TONIGHT INTO FRIDAY...A WEAK RIDGE WILL BUILD INTO THE CENTRAL CONUS
AHEAD OF THE NEXT SYSTEM THAT WILL PROGRESS INTO THE CENTRAL U.S.
THIS WEEKEND. SURFACE HIGH PRESSURE SITUATED OVER THE NORTHERN
PLAINS THIS AFTERNOON WILL SPILL SOUTHWARD INTO THE CENTRAL PLAINS
TONIGHT INTO FRIDAY. ONE AREA OF UNCERTAINTY IS WITH REGARDS TO THE
STRATUS DECK CURRENTLY UNDER THIS SURFACE HIGH AND WHETHER OR NOT
THE NORTHERLY FLOW WILL PUSH THIS DECK SOUTHWARD INTO EXTREME
NORTHEAST AND EASTERN KANSAS THIS EVENING. THE RAP IS THE MOST
AGGRESSIVE IN HOLDING LOW-LEVEL MOISTURE IN ACROSS NORTHEASTERN
KANSAS OVERNIGHT WHILE THE NAM/GFS/ECMWF SHOWS THE DRY AIR THAT IS
WEST OF THE CWA PREVAILING AND RESULTING IN CLEARING SKIES ACROSS
MUCH OF THE FORECAST AREA OVERNIGHT. WHETHER THIS STRATUS DECK
STRETCHES INTO THE REGION WILL ALSO IMPACT WHETHER THERE IS A
POTENTIAL FOR SOME PATCHY FOG TO DEVELOP EARLY FRIDAY MORNING DUE TO
THE LIGHT NORTHERLY WINDS AND THE PRESENCE OF SURFACE MOISTURE FROM
THE RAIN SHOWERS THIS MORNING. HAVE NOT ADDED ANY MENTION OF PATCHY
FOG IN THE FORECAST ATTM DUE TO THE UNCERTAINTY WITH THE MOVEMENT OF
THE STRATUS DECK...BUT WILL CONTINUE TO MONITOR THIS EVENING.
AS FOR TEMPERATURES...NORTHERLY FLOW WILL HELP TO DROP OVERNIGHT
LOWS INTO THE 20S. AS THE SURFACE HIGH SHIFTS EAST OF THE REGION ON
FRIDAY...WINDS WILL VEER TO THE EAST-SOUTHEAST WITH AFTERNOON HIGHS
RANGING FROM THE MID 40S OVER NORTHEAST KANSAS TO THE LOWER 50S
ACROSS CENTRAL KANSAS.
ACH
FRIDAY NIGHT THROUGH THURSDAY...AN UPPER LEVEL TROUGH WILL DIG
SOUTHEAST FROM THE PACIFIC NORTHWEST INTO THE FOUR CORNERS AREA LATE
FRIDAY NIGHT...THEN LIFT NORTHEAST INTO THE CENTRAL AND SOUTHERN
PLAINS SATURDAY NIGHT INTO SUNDAY.
SATURDAY THROUGH SATURDAY NIGHT...A LEE SURFACE LOW WILL DEVELOP
ACROSS EASTERN CO DURING THE DAY ON SATURDAY...THEN DEEPEN AHEAD OF
THE APPROACHING UPPER LEVEL TROUGH. SOUTHERLY LOW LEVEL WINDS AHEAD
OF THE LEE SURFACE LOW WILL ADVECT DEEPER GULF MOISTURE NORTHWARD
ACROSS EASTERN KS SATURDAY AFTERNOON AND EVENING. WAA/ISENTROPIC
LIFT WILL CAUSE SHOWERS TO DEVELOP ACROSS THE SOUTHERN COUNTIES OF
THE CWA THURSDAY AFTERNOON...THEN LIFT NORTHEAST ACROSS THE CWA
DURING THE EARLY EVENING HOURS. THE 12Z NAM AND ECMWF SHOW MUCAPE
INCREASING TO 300 TO 700 J/KG ACROSS THE CWA...THUS SCATTERED
ELEVATED THUNDERSTORMS WILL BE POSSIBLE ALONG WITH NUMEROUS SHOWERS
SATURDAY NIGHT INTO SUNDAY MORNING. THE SFC-6KM BULK SHEAR WILL BE
ABOUT 50 TO 60 KTS...THUS SOME OF THE STRONGER ELEVATED
THUNDERSTORMS MAY BE CAPABLE OF PRODUCING SMALL HAIL SATURDAY NIGHT.
WE MAY RECEIVE A QUARTER TO ONE HALF INCH OF RAINFALL...WITH SOME
LOCALLY HIGHER AMOUNTS SATURDAY NIGHT INTO SUNDAY MORNING.
SUNDAY...THE UPPER LEVEL TROUGH WILL LIFT NORTHEAST ACROSS NORTHWEST
KS INTO SOUTHWEST MN WHILE THE SURFACE LOW MOVES NORTHEAST ACROSS
EASTERN NE INTO NORTH CENTRAL IA. A PACIFIC COLD FRONT WILL MOVE
EAST ACROSS THE CWA DURING THE MORNING HOURS OF SUNDAY...AND WILL
BRING AN END TO THE SHOWERS AND SCATTERED THUNDERSTORMS ACROSS THE
EASTERN COUNTIES OF THE CWA. SKIES WILL CLEAR FROM SOUTHWEST TO
NORTHEAST ACROSS THE CWA...DURING THE LATE MORNING AND EARLY
AFTERNOON HOURS. THE WRAP AROUND PRECIP SHOULD REMAIN NORTH OF THE
STATE LINE...THOUGH CLOUDS AND PERHAPS SOME SPRINKLES OR FLURRIES
COULD DEVELOP ACROSS THE NORTHERN COUNTIES OF THE CWA DURING THE MID
AND LATE AFTERNOON HOURS. HIGHS ACROSS NORTH CENTRAL KS MAY BE
REACHED AROUND NOON...WITH SLOWLY FALLING TEMPERATURES INTO THE
UPPER 30S. THE REMAINDER OF THE CWA WILL WARM INTO THE UPPER 40S TO
MID 50S ACROSS EAST CENTRAL KS.
SUNDAY NIGHT THROUGH TUESDAY NIGHT...A SECOND UPPER LEVEL TROUGH
WILL DIG SOUTHWARD ACROSS THE WEST-CENTRAL CONUS INTO NM...THEN WILL
MOVE EAST ACROSS NORTH TX AND OK WHILE SHEARING OUT MONDAY NIGHT. THE
STRONGER ASCENT AND PRECIP CHANCES WILL OCCUR WELL SOUTH OF THE
CWA ACROSS SOUTHWEST KS AND OK. HIGHS WILL BE IN THE LOWER TO MID
40S. LOWS WILL BE IN THE 20S.
WEDNESDAY THROUGH THURSDAY...AN UPPER LEVEL TROUGH WILL MOVE ONSHORE
ACROSS THE PACIFIC NORTHWEST...THEN DIG SOUTHEAST ACROSS THE
NORTHERN AND CENTRAL PLAINS ON THURSDAY. AHEAD OF THE H5 TROUGH
TEMPERATURES WILL WARM INTO THE MID TO UPPER 40S. IF THE COLD FRONT
IS A BIT FASTER...THEN HIGH TEMPS ON THURSDAY WILL BE CAT OR TWO
COOLER. THE LOW-LEVELS OF THE ATMOSPHERE LOOK TOO DRY FOR ANY
MEASURABLE PRECIP. THE STRONGER ASCENT AHEAD OF THIS H5 TROUGH WILL
OCCUR ACROSS THE UPPER MIDWEST AND MID MS RIVER VALLEY...WELL
NORTHEAST OF THE CWA.
GARGAN
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1042 PM CST THU FEB 7 2013
.UPDATE...
LOW CLOUDS CONTINUE TO TREK SOUTHWESTWARD ACROSS EASTERN KS. THINK
THE LATEST RUC AND HRRR MODELS HAVE A GOOD FEEL FOR CURRENT
CONDITIONS...AND BRING THE LOW CLOUDS ALL THE WAY TO THE
I-135/HIGHWAY 14 CORRIDORS. HAVE ADJUSTED THE GRIDS/FORECAST TO
REFLECT THIS. STILL THINKING PATCHY FOG WILL BE POSSIBLE GENERALLY
WEST OF THE FLINT HILLS OVERNIGHT.
ADK
&&
.PREV DISCUSSION... /ISSUED 903 PM CST THU FEB 7 2013/
UPDATE...
SHORT-TERM GUIDANCE NOT HELPFUL THIS EVENING/OVERNIGHT REGARDING
LOW-LEVEL MOISTURE PROGS. CURRENT SWATH OF LOW CLOUDS APPROACHING
FROM THE NORTHEAST...ASSOCIATED WITH APPROACHING LOW-LEVEL COLD
ADVECTION...SHOULD MAKE IT INTO SOUTHEAST KS WITHIN THE NEXT FEW
HOURS. THINK LOW CLOUDS OVERNIGHT SHOULD REMAIN GENERALLY
ALONG/EAST OF THE FLINT HILLS...ALONG/EAST OF THE LOW-LEVEL RIDGE
AXIS. ADDITIONALLY...THINKING PATCHY FOG WILL BE POSSIBLE AFTER
MIDNIGHT GENERALLY ALONG/WEST OF THE FLINT HILLS...DUE TO
SLACKENING WINDS AND CLEAR SKIES AMIDST A NEWLY WET GROUND. BEST
CHANCES WILL LIKELY BE OVER CENTRAL/EAST-CENTRAL KS GENERALLY
NORTH OF HIGHWAY 50...WHERE LAST NIGHT`S RAINS WERE MOST
PLENTIFUL. NOT ANTICIPATING WIDESPREAD FOG...BUT PATCHY/SHALLOW
GROUND FOG FOR MAINLY LOW-LYING AREAS. SINCE TEMPERATURES WILL
LIKELY BE BELOW FREEZING...SLICK SPOTS ON ROADS/WALKWAYS COULD
DEVELOP IN FOGGY AREAS.
ADK
PREV DISCUSSION... /ISSUED 544 PM CST THU FEB 7 2013/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
FAIRLY QUIET VFR CONDITIONS EXPECTED FOR MUCH OF THE NEXT 24
HOURS. HOWEVER...COULD SEE SOME PATCHY AND SHALLOW GROUND FOG
LATE TONIGHT THROUGH EARLY FRIDAY MORNING ACROSS THE REGION...AS
HIGH PRESSURE SETTLES SOUTHEAST...ALLOWING FOR LIGHT WINDS AND
CLEAR SKIES OVER THE NEWLY WET GROUND. SINCE IT`LL LIKELY BE
SHALLOW AND PATCHY...PLAYED THE CONSERVATIVE ROUTE FOR NOW AND
ONLY WENT WITH 4SM BR ALL TAF SITES FROM ABOUT 11-15Z. WILL
CONTINUE TO ASSESS FOR 06Z TAF ISSUANCE.
ADK
PREV DISCUSSION... /ISSUED 313 PM CST THU FEB 7 2013/
DISCUSSION...
TONIGHT-FRI:
INITIAL CONCERN IS POTENTIAL FOR FREEZING GROUND FOG LATER TONIGHT...
ESPECIALLY IN THE MAXIMUM PRECIPITATION AXIS FROM ROUGHLY GBD TO
WEST OF EMP. LIGHT WINDS AND CLEAR SKIES WILL ALLOW TEMPERATURES
TO RADIATE INTO THE 20S IN THIS AREA. MODELS DO SHOW VERY DRY AIR
JUST OF THE DECK...SO NOT EXPECTED ANYTHING WIDESPREAD/DENSE AT
THIS TIME. THE MOIST GROUND MAY LIMIT MAX TEMPERATURES A FEW
DEGREES ON FRI...BUT ANTICIPATING 50S AREA WIDE.
FRI NIGHT-SUN:
ONE MORE COOL NIGHT ANTICIPATED AS RETURN FLOW APPEARS TO BE A
BIT SLOWER TO DEVELOP. BEST RETURN FLOW/MOISTURE WILL BE ON
SAT...WITH INCREASING CLOUDS/CHANCES OF PRECIPITATION DURING DAY.
AS TSA HINTED...RELATIVELY DRY AIR SAT AFTERNOON COULD CAUSE FAIR
AMOUNT OF EVAPORATIVE COOLING IF RAIN COMMENCES DURING THE DAY. BY
EVENING/OVERNIGHT...DEWPOINTS SHOULD PUSH WELL INTO THE
40S/50S...WITH GOOD CHANCE FOR RAIN SHOWERS/THUNDERSTORM. HAVE
UPPED MINIMUMS SAT NIGHT/SUN WITH MOST OF THE COLD AIR ONLY
REACHING CENTRAL KS BY DAYBREAK. LARGE DRY SLOT WILL BRING ABRUPT
END OF THE PRECIPITATION SUN MORNING. BASED ON LATEST GUIDANCE...
BELIEVE EVEN CENTRAL KS WILL ESCAPE THE WRAP AROUND PRECIPITATION
LATER SUN/SUN NIGHT.
MON-THU:
ECMWF CONTINUE TO BE VERY CONSISTENT WITH ITS PREVIOUS RUNS...
SUGGEST PRECIPITATION WILL REMAIN SOUTH OF THE AREA THROUGHOUT THE
PERIOD...AND GFS HAS COME AROUND TO THIS AS WELL. BOTH SUGGEST
TRAILING ENERGY IN LONG WAVE TROUGH WILL DEVELOP ANOTHER SURFACE
LOW ON COLD FRONT. WITH NEWER RUNS SHOWING FRONT GOING EVEN
FURTHER SOUTH...SO NORTHERN EDGE OF PRECIPITATION SHOULD REMAIN
SOUTH OF THE AREA. BOTH GFS/ECMWF 925 MILLIBAR MIXDOWN TEMPERATURES
SUGGEST TEMPERATURES IN AT LEAST THE UPPER 40S/LOWER 50S...BUT
WOULD NOT BE SURPRISED IF TEMPERATURES END UP WELL INTO THE 50S.
-HOWERTON
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE MAIN AVIATION FORECAST CONCERN WILL BE THE EXIT OF THE
PRECIPITATION...AND IFR/MVFR FLIGHT CONDITIONS. PRECIPITATION HAS
ENDED AT ALL TERMINALS EXCEPT KCNU AS OF 18Z. SKIES HAVE EITHER
CLEARED OR ARE CLEARING. HOWEVER...AT KCNU MVFR TO IFR CONDITIONS
ARE STILL POSSIBLE THROUGH THE REMAINDER OF THE DAY. VFR WILL
RETURN TO KCNU THIS AFTERNOON. THE SURFACE RIDGE AXIS WILL
TRAVERSE THE AREA OVERNIGHT CAUSING WINDS TO BE LIGHT AND VARIABLE
AND EVENTUALLY SWITCH AROUND TO THE SOUTH/SOUTHEAST. THE LIGHT AND
VARIABLE WINDS AND THE AMOUNT MOISTURE IN THE BOUNDARY LAYER MAKES
GROUND FOG A CONCERN FOR THE EARLY MORNING HOURS FRIDAY. HAVE
TRENDED THAT WAY WITH 4SM AND SCATTERED 1000FT CEILINGS. WILL NEED
TO WATCH THIS AND EDIT WITH LATER FORECASTS.
BILLINGS
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 28 53 35 52 / 0 0 0 40
HUTCHINSON 26 53 34 51 / 0 0 0 40
NEWTON 28 51 32 51 / 0 0 0 40
ELDORADO 28 52 33 51 / 0 0 0 40
WINFIELD-KWLD 29 53 35 52 / 0 0 0 40
RUSSELL 24 54 34 50 / 0 0 0 30
GREAT BEND 24 52 35 50 / 0 0 0 30
SALINA 26 51 34 53 / 0 0 0 30
MCPHERSON 26 52 34 51 / 0 0 0 30
COFFEYVILLE 30 53 35 54 / 0 0 0 40
CHANUTE 28 51 33 54 / 0 0 0 40
IOLA 28 50 33 54 / 0 0 0 30
PARSONS-KPPF 28 52 33 53 / 0 0 0 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
314 PM EST FRI FEB 08 2013
.Short Term (Tonight - Saturday night)...
Issued at 237 PM EST Fri Feb 8 2013
A long ridge of high pressure stretching from eastern Canada to the
Gulf of Mexico will keep our weather quiet tonight and into the
weekend. Low clouds will likely stick around into this evening
before finally breaking up overnight. With clearing skies and winds
becoming light, temperatures should be able to drop well into the
20s. Some light patchy fog could form around sunrise but dew point
depressions should remain large enough to prevent anything
significant.
Saturday will be a pleasant day with light winds, mostly sunny
skies, and afternoon temperatures peaking in the 40s north to around
50 south.
Saturday night a weak warm front, extending eastward from low
pressure over the Central Plains, will move through. This feature
will increase clouds and turn winds around to the south southeast by
Sunday morning. Low temperatures will likely occur around midnight
and then either go steady or rise a couple of degrees. The mercury
will bottom out in the 30s.
.Long Term (Sunday - Thursday Night)...
Issued at 300 PM EST Fri Feb 8 2013
The start of the long term period will feature a broad trough across
the central United States with an amplified ridge over the eastern
seaboard. This trough will push east through the Ohio Valley
through the extended period, providing good chances for
precipitation on Sunday followed by a period of seasonal weather
conditions.
A strong shortwave trough will eject out of the broad central CONUS
trough on Sunday, inducing a surface low across the Upper
Mississippi Valley as the parent trough takes on a negative tilt.
This surface low will quickly push northeast across the northern
Great Lakes.
Ahead of this system, a warm and moist airmass will
quickly spread north into the Ohio Valley. PWATs will be 2-3
standard deviations above normal for mid February, which will set
the stage for some moderate to locally heavy rainfall. The initial
wave of isentropic ascent will overspread central KY and southern IN
around 12-18Z Sunday. Model soundings and cross-sections show quite
a bit of low-level dry air to overcome, however, so think that the
bulk of the precipitation will hold off until after 18Z on Sunday.
Despite the best forcing going north, moist/convergent flow on the
nose of a 45-55 knot low-level jet coupled with moderate height
falls aloft should yield a solid line of moderate to locally heavy
rainfall out ahead of the surface front.
Thunder potential with Sunday`s system looks marginal, but enough to
warrant a slight chance mention. A very moist airmass (soundings
fully saturated almost up to 200 mb!) will definitely limit overall
instability, but given the strengthening/convergent low-level wind
fields, embedded updrafts capable of some thunder will be possible
as the system rolls through. A stout warm nose at 850 mb will limit
the potential for anything to become surface-based, so severe
weather does not appear likely at this time. Therefore, locally
heavy rainfall and some gusty sub-severe winds look to be the main
threats with this system.
Dry conditions will work in for Monday and Tuesday. Monday still
looks rather warm (highs in the 50s) before another reinforcing shot
of cold air arrives on Tuesday, dropping highs back into the 40s.
Guidance then begins to diverge with the handling of a southern
stream system on Wednesday. The 08/12Z GFS has been quite
aggressive the past run or two with bringing a deformation band of
rain/snow into southern KY. In fact, taken at face value, the
08/12Z GFS would give several inches of a heavy, wet snow to
southern KY. The bad news for all you snow lovers is that the ECMWF
has been very consistent in its solution of keeping all the
precipitation south. Therefore, will lean toward the consistent
ECMWF and continue with a dry forecast. However, this system will
need to be watched in the coming days as the operational GFS now is
gaining some support from some of its 08/12Z ensemble members.
Otherwise, the Wednesday system quickly pushes east, allowing for
dry conditions to work back in for Thursday. After highs in the 40s
on Wednesday, temperatures will rebound into the upper 40s and lower
50s on Thursday.
&&
.Aviation (18Z TAF Issuance)...
Issued at 1218 PM EST Fri Feb 8 2013
With high pressure moving in, low ceilings are the main challenge.
The models aren`t much help, with the NAM12 saying we should already
be sunny. However, the HRRR and RR agree that the low clouds will
hang tough through at least this evening, and knowing how
notoriously slow low ceilings can be to clear out (versus model
projections), will hold on to the MVFR ceilings for several more
hours. Of some concern is some thin spots and breaks showing up
across Illinois and Indiana, though, so will have to keep an eye on
those.
Some light BR isn`t entirely out of the question overnight, but even
if skies do clear out it appears that dew point depressions will
remain large enough to keep any visibility restrictions out of the
TAFs for now.
Northwest winds of 10 to 15 knots, with a few higher gusts, today
will become light tonight and then shift to the east on Saturday
around 5 to 10 knots.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......13
Long Term........KJD
Aviation.........13
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1218 PM EST FRI FEB 08 2013
...Updated Aviation Discussion...
.Short Term (Today - Saturday)...
Issued at 300 AM EST Fri Feb 8 2013
Surface low pressure now is over northern Ohio, with a trailing cold
front close to the Ohio River. Area of light to moderate rain
showers extends around this front. Water vapor imagery depicts two
separate troughs, one passing by to our north and another over the
Mid Atlantic coast. The merger of these two systems is forecast to
bring a major winter storm over the Northeast.
Our weather will be decidely quieter. After the rains clear the
east forecast area by mid morning, northwest winds behind the front
will mean much cooler temperatures than yesterday. Highs likely will
come this morning and remain steady through the day, with values
20-25 degrees cooler than yesterday. Cloud cover will linger in the
wake of the front, as seen by upstream clouds across Il/IA/MO. High
pressure will build into the Midwest tonight, bringing lighter winds
overnight. Those clouds should start breaking up this evening. Thus
not looking at ideal cooling conditions, but readings should fall to
near normal. The surface high Saturday will shift to around Lake
Erie, which will mean a start to easterly winds over us. Under
mostly sunny skies, we likely will see high temperatures in the 40s,
even up to around 50 across south central Kentucky.
.Long Term (Saturday Night - Thursday)...
Issued at 300 AM EST Fri Feb 8 2013
An upper low is still on track to eject out of the Desert Southwest
late Saturday, traverse the upper Mississippi Valley, and move over
the upper Great Lakes by Monday afternoon. This upper low and
associated surface reflection will strengthen along the way and
become vertically stacked by Sunday night. Ahead of this system,
broad southwesterly flow will supply unseasonably warm and moist
conditions Sunday into Monday. Highs Sunday and Monday in the low to
upper 50s are expected, with cloud cover and eventually precip
helping keep us from reaching full warming potential. Soundings
continue to indicate precipitable water values will be slightly
above one inch, or around +2 standard deviations for this time of
year.
So, precipitation chances will increase through the day Sunday as
the low pressure system pushes east and the associated cold front
approaches the Ohio Valley. A few showers Sunday morning are not out
of the question mainly west of the I-65 corridor as a warm front
lifts north. However, the greatest chance of area-wide showers and
embedded storms will be later in the afternoon and evening. Precip
will begin to diminish from west to east by midnight Monday morning.
The GFS has been slowly backing down on the wind speeds at 925 and
850 hPa over the last few days, while the ECMWF has increased a few
knots. Believe 45-55 knots will be common wind speeds for the
low-level jet. The anticipated cloud cover Sunday appears to limit
overall instability and soundings continue to advertise a stout cap.
Additionally, the abnormally high atmospheric moisture will limit
instability, with precip-efficient convection becoming more notable.
Still not overly impressed with this system, and some guidance is
showing better organized convection well to our south (associated
with better instability) and another area to our north (associated
with better dynamics). Currently it appears we will have showers and
some thunderstorms with gusty winds that will put down moderate to
perhaps heavy rain at times.
Surface high pressure will build in behind the departing system
Monday, with more seasonable temperatures and dry conditions
expected through at least Tuesday with the frontal boundary
positioned across the deep south. The final upper low across the
Desert Southwest will eject eastward Tuesday. Models seem to be
coming into better agreement (though the GFS has been flip-flopping
as of late) that the main forcing associated with this trough will
remain south of the forecast area, keeping active weather across the
southern states. This is forecast to be a positively tilted trough,
which provides further confidence that substantial moisture will not
be pulled northward into our area. So, will go with a dry forecast
for Tuesday night through Thursday. Surface winds will be
west-northwesterly, with high temperatures in the 40s and overnight
lows ranging from the mid 20s to low 30s.
&&
.Aviation (18Z TAF Issuance)...
Issued at 1218 PM EST Fri Feb 8 2013
With high pressure moving in, low ceilings are the main challenge.
The models aren`t much help, with the NAM12 saying we should already
be sunny. However, the HRRR and RR agree that the low clouds will
hang tough through at least this evening, and knowing how
notoriously slow low ceilings can be to clear out (versus model
projections), will hold on to the MVFR ceilings for several more
hours. Of some concern is some thin spots and breaks showing up
across Illinois and Indiana, though, so will have to keep an eye on
those.
Some light BR isn`t entirely out of the question overnight, but even
if skies do clear out it appears that dew point depressions will
remain large enough to keep any visibility restrictions out of the
TAFs for now.
Northwest winds of 10 to 15 knots, with a few higher gusts, today
will become light tonight and then shift to the east on Saturday
around 5 to 10 knots.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......RJS
Long Term........MJP
Aviation.........13
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
305 AM EST FRI FEB 08 2013
.Short Term (Today - Saturday)...
Issued at 300 AM EST Fri Feb 8 2013
Surface low pressure now is over northern Ohio, with a trailing cold
front close to the Ohio River. Area of light to moderate rain
showers extends around this front. Water vapor imagery depicts two
separate troughs, one passing by to our north and another over the
Mid Atlantic coast. The merger of these two systems is forecast to
bring a major winter storm over the Northeast.
Our weather will be decidely quieter. After the rains clear the
east forecast area by mid morning, northwest winds behind the front
will mean much cooler temperatures than yesterday. Highs likely will
come this morning and remain steady through the day, with values
20-25 degrees cooler than yesterday. Cloud cover will linger in the
wake of the front, as seen by upstream clouds across Il/IA/MO. High
pressure will build into the Midwest tonight, bringing lighter winds
overnight. Those clouds should start breaking up this evening. Thus
not looking at ideal cooling conditions, but readings should fall to
near normal. The surface high Saturday will shift to around Lake
Erie, which will mean a start to easterly winds over us. Under
mostly sunny skies, we likely will see high temperatures in the 40s,
even up to around 50 across south central Kentucky.
.Long Term (Saturday Night - Thursday)...
Issued at 300 AM EST Fri Feb 8 2013
An upper low is still on track to eject out of the Desert Southwest
late Saturday, traverse the upper Mississippi Valley, and move over
the upper Great Lakes by Monday afternoon. This upper low and
associated surface reflection will strengthen along the way and
become vertically stacked by Sunday night. Ahead of this system,
broad southwesterly flow will supply unseasonably warm and moist
conditions Sunday into Monday. Highs Sunday and Monday in the low to
upper 50s are expected, with cloud cover and eventually precip
helping keep us from reaching full warming potential. Soundings
continue to indicate precipitable water values will be slightly
above one inch, or around +2 standard deviations for this time of
year.
So, precipitation chances will increase through the day Sunday as
the low pressure system pushes east and the associated cold front
approaches the Ohio Valley. A few showers Sunday morning are not out
of the question mainly west of the I-65 corridor as a warm front
lifts north. However, the greatest chance of area-wide showers and
embedded storms will be later in the afternoon and evening. Precip
will begin to diminish from west to east by midnight Monday morning.
The GFS has been slowly backing down on the wind speeds at 925 and
850 hPa over the last few days, while the ECMWF has increased a few
knots. Believe 45-55 knots will be common wind speeds for the
low-level jet. The anticipated cloud cover Sunday appears to limit
overall instability and soundings continue to advertise a stout cap.
Additionally, the abnormally high atmospheric moisture will limit
instability, with precip-efficient convection becoming more notable.
Still not overly impressed with this system, and some guidance is
showing better organized convection well to our south (associated
with better instability) and another area to our north (associated
with better dynamics). Currently it appears we will have showers and
some thunderstorms with gusty winds that will put down moderate to
perhaps heavy rain at times.
Surface high pressure will build in behind the departing system
Monday, with more seasonable temperatures and dry conditions
expected through at least Tuesday with the frontal boundary
positioned across the deep south. The final upper low across the
Desert Southwest will eject eastward Tuesday. Models seem to be
coming into better agreement (though the GFS has been flip-flopping
as of late) that the main forcing associated with this trough will
remain south of the forecast area, keeping active weather across the
southern states. This is forecast to be a positively tilted trough,
which provides further confidence that substantial moisture will not
be pulled northward into our area. So, will go with a dry forecast
for Tuesday night through Thursday. Surface winds will be
west-northwesterly, with high temperatures in the 40s and overnight
lows ranging from the mid 20s to low 30s.
&&
.Aviation (06Z TAF Issuance)...
Issued at 1200 AM EST Fri Feb 8 2013
A cold front is approaching the terminals early this morning, and
will bring some light rain showers, and perhaps a rumble of thunder
to KBWG, but not high enough risk to put in TAFs. The winds will
veer ahead of the front, then become westnorthwesterly quickly as
the front moves through. Upstream obs behind this front indicate IFR
cigs are pretty likely an hour or two behind it. High-res RAP model
indicates low cigs will stick around for awhile behind this front.
Have kept IFR conditions through the morning for each site before
going up to the MVFR range in the afternoon.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......RJS
Long Term........MJP
Aviation.........RJS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1142 PM CST THU FEB 7 2013
.UPDATE...
ISSUED AT 1142 PM CST THU FEB 7 2013
UPDATED FOR 06Z TAF ISSUANCE.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 257 PM CST THU FEB 7 2013
BASED ON CURRENT RADAR...LINE OF SHOWERS WILL REACH FAR WESTERN
PORTIONS OF THE PAH FORECAST AREA AROUND 22Z...SPREADING ACROSS
SOUTHEAST MISSOURI INTO SOUTHERN ILLINOIS BETWEEN 00Z AND
02Z...REACHING FAR WEST KENTUCKY AND SOUTHWEST INDIANA BETWEEN 02Z
AND 03Z...THEN INTO THE PENNYRILE REGION OF WEST KENTUCKY LATE
THIS EVENING. THE NAM12 AND RUC LINE UP WELL WITH THIS
TIMING...AND THE NAM HAS PRECIP CLEARING THE PAH FA BY 12Z FRIDAY.
HAVE LIKELY TO CATEGORICAL POPS ACROSS THE ENTIRE FA FOR A LEAST A
FEW HOURS SHIFTING FROM WEST TO EAST BETWEEN 00Z AND 10Z. INCLUDED
SOME ISOLATED THUNDER CHANCES ACROSS THE SOUTHERN HALF OF THE
REGION THIS EVENING BASED ON LIGHTNING DATA OCCASIONALLY SHOWING A
FEW STRIKES IN SOUTHERN MISSOURI AND NAM AND SREF SHOWING NEAR
ZERO LI`S MAKING IT INTO THE AREA....ESPECIALLY IN SOUTHEAST
MISSOURI. ANY THUNDER POSSIBILITY SHOULD END BY MIDNIGHT.
DRY AND COOLER WEATHER IS EXPECTED FRIDAY INTO FRIDAY NIGHT AS
HIGH PRESSURE SLIDES THROUGH THE GREAT LAKES REGION. RH TIME
HEIGHTS SHOW VERY DRY AIR ACROSS THE REGION...SO WE SHOULD SEE
LOTS OF SUNSHINE ON FRIDAY AND MOSTLY CLEAR SKIES INTO FRIDAY
NIGHT. TEMPERATURES WILL BE NEAR SEASONAL FRIDAY AND FRIDAY
NIGHT...THEN A FEW DEGREES WARMER FOR SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 257 PM CST THU FEB 7 2013
00Z AND 12Z RUNS CONFIRM A FASTER APPROACH/PASSAGE OF THE WEEKEND
WEATHER SYSTEM OF NOTE. THE 12Z GFS IS NOW TRACKING THE SURFACE AND
UPPER LOWS FROM THE PLAINS STATES...NORTHEASTWARD TO THE GREAT
LAKES...A SUBTLE NORTHWARD SHIFT MORE AKIN TO THE 12Z YESTERDAY AND
00Z EURO TRACKS. BOTH MODELS PUSH THE FRONT OUT AHEAD AND SPEED UP
THE INTRO/PASSAGE/DEPARTURE OF PCPN FOR OUR AREA. THIS WILL
TRANSLATE TO INTRODUCTORY POPS SAT NIGHT...PEAK POPS SUNDAY...WITH
ENDING/DEPARTURE POPS SUNDAY NIGHT.
THE SYSTEM WILL HAVE MAINLY ELEVATED INSTABILITY...WITH THE MAX
SURFACE INSTABILITY AXIS FOCUSED ALONG THE LOWER MS VALLEY TO THE
GULF COAST. THIS IS BASED ON A RIBBON OF 50F TD MAKING ITS WAY INTO
OUR AREA...AND THIS AXIS COULD EXTEND FURTHER NORTHWARD IF TDS DO IN
FACT CLIMB HIGHER. STILL...WITH THE COLD FRONT INCOMING...AND
POWERFUL WIND FIELDS ALOFT...A DAMAGING WIND THREAT WILL ACCOMPANY
STORMS SHOULD THEY DEVELOP/BECOME SVR. BRN MAG TO 100KTS MIGRATES
ACROSS THE FA WITH THE SYSTEM/WHILE WEAK BULLSEYES OF 0-2KM VORT GEN
AND LAYER TOR PARAMETERS SUGGEST ISOLD TORS ARE POSSIBLE TOO. WILL
CONTINUE THE HIGHLIGHT OF THIS POSSIBILITY VIA THE HWO.
WITH POWERFUL WINDS PROPELLING THE SYSTEM THRU...WE SHOULD SEE QUICK
BURST QPF OF 1/2 TO 1 INCH ON AVERAGE FOR THE BASINS. HOWEVER...WITH
GFS SOUNDINGS REVEALING 1-1.25" PW`S PUSHING THE 99TH PERCENTILE FOR
THIS TIME OF YEAR...LOCALIZED HEAVIER RAINFALL COULD CREATE SOME
FLOOD ISSUES/OR AT LEAST CAUSE HEIGHTENED CONCERN/SOMETHING TO KEEP
AN EYE UPON.
MONDAY-TUESDAY...THE MODELS BACK OFF SOMEWHAT ON THE
STALLED/RETURNING BOUNDARY SCENARIO ACROSS OUR SOUTHERN COUNTIES. SO
WE`LL CONTINUE TO OMIT FOR THIS PACKAGE...AND WE`LL GO AHEAD AND
KEEP THE CLEAN FROPA AND RETURN POPS IF/WHEN NEEDED...IF FUTURE RUNS
SUGGEST SO. ONE SUCH TIME IS TUESDAY NIGHT. WE WENT SLGT CHC PCN AS
2NDARY TROF/LOW ROTATES ACROSS AREA. GIVEN THERMAL PROFILE AT THAT
TIME/WE CARRY EITHER/OR -RA/-SN. MINIMAL QPF EVENT BUT ALL
CONSIDERED AND WITH COLLAB...CURSORY SLGT CHC WARRANTED FOR NOW.
THE WARM PRE-FRONTAL ENVIRO WILL COOL FROM HIGHS IN THE 50S/NR 60
EARLY...BACK TO THE MORE FEBRUARY LIKE 40S BY MID WEEK. LOWS WILL
RESPOND IN KIND...RETURNING CLOSER TO NORMS BY THEN AS WELL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY EVENING)
ISSUED AT 1142 PM CST THU FEB 7 2013
RAIN WILL TAPER OFF OVERNIGHT AS A COLD FRONT SHIFTS EAST OF THE
REGION. IN THE WAKE OF THE FRONT...MVFR CEILINGS AND GUSTY WINDS
FROM THE NORTHWEST WILL PREVAIL. CLOUDS ARE LIKELY TO BE SLOW TO
CLEAR ON FRIDAY...WITH SUBSTANTIAL CLEARING NOT EXPECTED UNTIL
AFTERNOON.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...RST
LONG TERM...DH
AVIATION...RJP
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1203 AM EST FRI FEB 08 2013
...Updated Aviation Discussion...
.Short Term (Tonight - Friday night)...
Issued at 248 PM EST Thu Feb 7 2013
Low pressure near St Louis this evening will quickly move to
Cleveland by morning. As it moves by it will swing its cold front
through southern Indiana and central Kentucky overnight. A band of
showers will accompany the front, dropping about a quarter of an
inch of rain. A rumble of thunder isn`t entirely out of the
question in the Bowling Green region.
Temperatures tonight will likely drop into the middle and upper 30s
behind the front over southern Indiana and stay in the lower 40s
across much of Kentucky. Deep moisture and lift will be exiting as
the colder air comes in so we will keep all precipitation as liquid.
Friday will be noticeably different from today. As the front moves
well off to the east light rain and drizzle will taper off by mid
morning. Low clouds will likely hang tough through at least the
morning hours before beginning to break up in the afternoon.
Temperatures will be in the 40s with brisk northwest winds gusting
to around 20 mph.
Friday night high pressure will ridge in from the northwest, calming
our winds and clearing our skies. Temperatures will fall well into
the 20s.
.Long Term (Saturday - Thursday)...
Issued at 300 PM EST Thu Feb 7 2013
The long term will start out with light winds and mostly clear skies
with surface high pressure across the region. Temperatures will rise
into the mid 40s to upper 50s through the afternoon.
The latter half of the weekend, however, will feature more unsettled
weather. A low pressure system will track from Colorado on Saturday
afternoon to Wisconsin by Monday morning and then across the Great
Lakes region. A warm front associated with this system will move
north across the area Sunday morning. This may bring a few showers
to far southern and western portions of the forecast area.
The bulk of the precipitation, however will be Sunday afternoon into
Sunday night as the cold front approaches. The models still show
winds at 925 mb around 50-60 knots. As mentioned in the previous
forecast discussion, though, instability will be lacking with this
system. There will be a cap in place as temperatures a few thousand
feet off the surface show warming. Also, precipitable water values
will be rising to over an inch, so rain could be moderate to heavy
at times. Right now it looks like we will have showers with a chance
for some thunderstorms with gusty winds.
The rain will move out late Sunday night into Monday morning before
tapering off. The cold front will move through on Monday with colder
air filtering in late in the day. Temperatures still look like they
will top out in the 50s before they begin to fall into the 30s
Monday night. The models do still diverge on Tuesday night with the
GFS developing a low pressure system that tracks just to the south
of the forecast area. This would spread a mix of rain/snow to the
region. However, the ECMWF continues to keep everything further to
the south with dry conditions expected. Will continue to trend the
forecast drier, but hang on to slight chance pops Tuesday
night/Wednesday.
&&
.Aviation (06Z TAF Issuance)...
Issued at 1200 AM EST Fri Feb 8 2013
A cold front is approaching the terminals early this morning, and
will bring some light rain showers, and perhaps a rumble of thunder
to KBWG, but not high enough risk to put in TAFs. The winds will
veer ahead of the front, then become westnorthwesterly quickly as
the front moves through. Upstream obs behind this front indicate IFR
cigs are pretty likely an hour or two behind it. High-res RAP model
indicates low cigs will stick around for awhile behind this front.
Have kept IFR conditions through the morning for each site before
going up to the MVFR range in the afternoon.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......13
Long Term........EER
Aviation.........RJS
AREA FORECAST DISCUSSION
NWS JACKSON KY
1156 PM EST THU FEB 7 2013
.UPDATE...
ISSUED AT 1156 PM EST THU FEB 7 2013
COLD FRONT IS PROGRESSING ACROSS CNTRL KY AS FCST. LOWER CEILINGS ARE
ALREADY BEGINNING TO PUSH INTO THE I-75 CORRIDOR AND WILL CONTINUE TO
ADVANCE AS THE FRONT GETS CLOSER. UPDATED GRIDS WITH CURRENT OBS...
ZONES ARE IN GOOD SHAPE.
UPDATE ISSUED AT 854 PM EST THU FEB 7 2013
HI RES MODELS ARE MUCH QUICKER ON BLOWING THIS FRONT ACROSS EASTERN
KENTUCKY LATE TONIGHT INTO TOMORROW MORNING...SO IT LOOKS LIKE RAIN
MAY COME TO AN END BY LATE MORNING IN THE FAR EASTERN COUNTIES AND
PERHAPS SHORTLY AFTER DAYBREAK FOR AREAS CLOSER TO I-75. RAINFALL
AMOUNTS AGAIN SHOULD BE LIGHT...BUT ENOUGH TO KEEP THINGS WET
TOMORROW MORNING. LOOKING AT THE LATEST SATELLITE REVEALS EXTENSIVE
LOW CLOUDS BEHIND THE FRONT SUSTAINED BY STEADY NORTHWEST WINDS.
CONSIDERING THIS WOULD BE UPSLOPE FLOW FOR US AND GIVEN THE CLOUDS
ALREADY IN PLACE...WE MAY NOT CLEAR OUT AS ADVERTISED TOMORROW.
THUS...IT LOOKS MORE LIKELY WE WILL STAY SOCKED IN TOMORROW. THIS
LIKELY WON`T HAVE MUCH IMPACT ON HIGHS AS THE HIGH SHOULD LIKELY
OCCUR EARLY IN THE DAY BEFORE COLD ADVECTION TAKES OVER.
UPDATE ISSUED AT 548 PM EST THU FEB 7 2013
UPDATED THIS EVENING TO REFINE THE BETTER PRECIPITATION CHANCES WITH
THE HELP OF THE HRRR AND RUC. LOOKS LIKE PRECIPITATION SHOULD MOVE
INTO OUR WESTERN COUNTIES SHORTLY AFTER 1 AM TONIGHT AND REACH OUR
FAR EASTERN COUNTIES AROUND 7 OR 8 AM. ALSO INCREASED PRECIPITATION
CHANCES INTO THE CATEGORICAL RANGE GIVEN THE GOOD LIKELIHOOD OF
MEASURABLE RAIN ACROSS THE ENTIRE AREA. SENT GRIDS TO NDFD AND WILL
BE UPDATED THE ZFP SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 257 PM EST THU FEB 7 2013
THE MODELS WERE ALL IN VERY GOOD AGREEMENT WITH THEIR HANDLING OF THE
FIRST 36 HOURS OF THE NEW WEATHER FORECAST FOR EASTERN KENTUCKY. THE
CONSENSUS IS FOR AN AREA OF LOW PRESSURE TO CONTINUE MOVING ACROSS
THE TENNESSEE VALLEY...INTO THE SOUTHEASTERN UNITED STATES...AND
EVENTUALLY UP THE EASTERN SEABOARD. DUE TO THE APPROACH OF A STRONG
COLD FRONT FROM THE WEST...AND THE STRENGTH OF AN AREA OF HIGH
PRESSURE THAT IS CURRENTLY PARKED OVER THE OHIO VALLEY...THE SOUTHERN
STREAM SYSTEM MENTIONED EARLIER WILL NOT BE ABLE TO MOVE FAR ENOUGH
NORTH TO SPREAD ITS PRECIPITATION INTO EASTERN KENTUCKY. THE ONE
THING THE SOUTHERN STREAM SYSTEM WILL DO IS SPREAD ITS CLOUD COVER
ACROSS THE SOUTHERN HALF OF THE FORECAST AREA THROUGH LATE THIS
EVENING. EVENTUALLY THE CLOUD COVER ASSOCIATED WITH THE APPROACHING
COLD FRONT WILL OVERSPREAD THE ENTIRE AREA FROM THE WEST LATER
TONIGHT. THE WEATHER MAKER FOR OUR AREA WILL BE THE AFOREMENTIONED
COLD FRONT. THIS BOUNDARY IS PROGGED TO MOVE ACROSS CENTRAL KENTUCKY
DURING THE DAY ON FRIDAY. AS IT DOES SO A LINE OF LIGHT RAIN SHOWERS
WILL MOVE ACROSS THE AREA WITH IT. THIS WILL BE A FAST MOVING
SYSTEM...SO THE PRECIPITATION WILL BE SHORT LIVED. COLDER AIR WILL
SPILL INTO THE AREA BEHIND THE FRONT...PAVING THE WAY FOR A FRIGID
NIGHT FRIDAY NIGHT. LOWS FRIDAY NIGHT WILL BOTTOM OUT IN THE 20S
ACROSS THE AREA...AFTER HIGHS ON FRIDAY ONLY MAKE IT INTO THE 40S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST THU FEB 7 2013
THE MODELS ARE IN PRETTY GOOD AGREEMENT CONSIDERING THE HIGHLY
AMPLIFIED PATTERN OVER THE CONUS. RIDGING THROUGH THE OHIO VALLEY
WILL GIVE WAY TO A DEEP TROUGH PINWHEELING THROUGH THE GREAT PLAINS
OVER THE WEEKEND. THIS WILL GRADUALLY LOWER HEIGHTS OVER THE AREA AS
IT BRUSHES BY KENTUCKY TO START THE NEW WORK WEEK. THE MODELS ARE
QUITE SIMILAR WITH THIS SO A CONSENSUS LOOKS REASONABLE. THE MORE
CHALLENGING PART OF THE FORECAST APPEARS TO BE FOR MID WEEK AS A
SOUTHERN STREAM TROUGH DRAGS ITS WAY THROUGH THE DEEP SOUTH. THE
MODELS HAVE A SIGNIFICANT SPREAD WHEN IT COMES TO THIS WAVE MOVING
THROUGH...JUST SOUTH OF THE AREA. THE ECMWF IS SLOWER AND A BIT
FURTHER SOUTH WITH ITS CORE ENERGY THAN THE GFS AND THE FLATTER GEM.
THE ENSEMBLES OF THE ECMWF APPEAR TO HAVE THE MORE REASONABLE
SOLUTION SPECTRUM WITH THIS IN KEEPING THE STREAMS SEPARATE UNTIL
EVERYTHING GETS EAST OF THE APPALACHIANS. ACCORDINGLY...HAVE FAVORED
A MODEL CONSENSUS THROUGH MONDAY BEFORE LEANING MORE ON THE
OPERATIONAL ECMWF FOR WEATHER SPECIFICS FOR THE LATER PARTS OF THE
EXTENDED.
SENSIBLE WEATHER WILL FEATURE LOW CLOUDS AND THE BULK OF THE MOISTURE
FROM THIS UPCOMING SYSTEM ON THE WAY OUT FOR SATURDAY AS HIGH
PRESSURE BUILDS IN. THE NEXT WEATHER MAKER COMES IN ON SUNDAY WITH
PLENTY OF WARM AIR TO MAKE THE PCPN FALL AS ALL LIQUID. THIS WETTER
SYSTEM WILL PUSH A COLD FRONT THROUGH DURING SUNDAY NIGHT WITH A
DECENT BOUT OF RAIN APPEARING LIKELY. THE COLD AIR IN THE WAKE OF
THIS WILL STAY MAINLY TO THE NORTH OF THE AREA...AS IT HAS FOR MUCH
OF THE WINTER. A WAVE WILL MOVE ALONG THE FRONT STALLED TO OUR SOUTH
ON TUESDAY INTO WEDNESDAY WITH A SMALL POTENTIAL OF RIDING CLOSE
ENOUGH TO THE AREA TO GIVE EAST KENTUCKY SOME MIXED PCPN TUESDAY
NIGHT INTO WEDNESDAY MORNING. HIGH PRESSURE FOLLOWS THIS WAVE AND
WILL DRY THE REGION BACK OUT AS FAIRLY MILD CONDITIONS CONTINUE.
THE CR GRID LOAD CAME IN A BIT HEAVY ON THE GFS SOLUTION FOR THE
LATTER PART OF THE EXTENDED WITH RESPECT TO POP AND SKY. HAVE BACKED
OFF THIS TO SOME EXTENT IN FAVOR OF THE MORE SUPPRESSED ECMWF
SOLUTION. MADE JUST SOME SMALL TERRAIN BASED TWEAKS TO THE LOW
TEMPERATURES ON SATURDAY...MONDAY...AND WEDNESDAY NIGHTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1150 PM EST THU FEB 7 2013
VFR CONDITIONS ARE GIVING WAY TO A COLD FRONT PUSHING ACROSS CNTRL KY
TONIGHT INTO FRIDAY MORNING. A BAND OF LIGHT RAIN SHOWERS WILL PUSH
EAST LATE TONIGHT. IN THE WAKE OF THE FRONT...CIGS WILL CRASH QUICKLY
WITH UPSTREAM OBS INDICATING CIGS AS LOW AS 400-600 FEET. THUS...THIS
WILL ESSENTIALLY SHUT DOWN AIRPORTS IN EASTERN KENTUCKY EARLY
THIS MORNING. SOME IMPROVEMENT IN CIGS IS ANTICIPATED TODAY...LIFTING
TO MVFR BY EARLY AFTERNOON. HOWEVER...STILL LOTS OF UNCERTAINTY AS TO
WHETHER OR NOT WE WILL CLEAR OUT. PLENTY OF STRATUS EXTENDS WELL BACK
TO THE NORTHWEST OVER IOWA AND INTO THE DAKOTAS. IF THIS CONTINUES TO
FILL IN BEHIND THE FRONT...AND HISTORICALLY A NORTHWEST FLOW TRAPS
MOISTURE IN AN UPSLOPE FLOW...THEN THE POTENTIAL CLEARING WILL BE VERY
QUESTIONABLE. THUS...LOTS OF UNCERTAINTY WITH THE CIG FORECAST AFTER
18Z TOMORROW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DUSTY
SHORT TERM...AR
LONG TERM...GREIF
AVIATION...DUSTY
AREA FORECAST DISCUSSION
NWS JACKSON KY
1150 PM EST THU FEB 7 2013
.UPDATE...
ISSUED AT 854 PM EST THU FEB 7 2013
HI RES MODELS ARE MUCH QUICKER ON BLOWING THIS FRONT ACROSS EASTERN
KENTUCKY LATE TONIGHT INTO TOMORROW MORNING...SO IT LOOKS LIKE RAIN
MAY COME TO AN END BY LATE MORNING IN THE FAR EASTERN COUNTIES AND
PERHAPS SHORTLY AFTER DAYBREAK FOR AREAS CLOSER TO I-75. RAINFALL
AMOUNTS AGAIN SHOULD BE LIGHT...BUT ENOUGH TO KEEP THINGS WET
TOMORROW MORNING. LOOKING AT THE LATEST SATELLITE REVEALS EXTENSIVE
LOW CLOUDS BEHIND THE FRONT SUSTAINED BY STEADY NORTHWEST WINDS.
CONSIDERING THIS WOULD BE UPSLOPE FLOW FOR US AND GIVEN THE CLOUDS
ALREADY IN PLACE...WE MAY NOT CLEAR OUT AS ADVERTISED TOMORROW.
THUS...IT LOOKS MORE LIKELY WE WILL STAY SOCKED IN TOMORROW. THIS
LIKELY WON`T HAVE MUCH IMPACT ON HIGHS AS THE HIGH SHOULD LIKELY
OCCUR EARLY IN THE DAY BEFORE COLD ADVECTION TAKES OVER.
UPDATE ISSUED AT 548 PM EST THU FEB 7 2013
UPDATED THIS EVENING TO REFINE THE BETTER PRECIPITATION CHANCES WITH
THE HELP OF THE HRRR AND RUC. LOOKS LIKE PRECIPITATION SHOULD MOVE
INTO OUR WESTERN COUNTIES SHORTLY AFTER 1 AM TONIGHT AND REACH OUR
FAR EASTERN COUNTIES AROUND 7 OR 8 AM. ALSO INCREASED PRECIPITATION
CHANCES INTO THE CATEGORICAL RANGE GIVEN THE GOOD LIKELIHOOD OF
MEASURABLE RAIN ACROSS THE ENTIRE AREA. SENT GRIDS TO NDFD AND WILL
BE UPDATED THE ZFP SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 257 PM EST THU FEB 7 2013
THE MODELS WERE ALL IN VERY GOOD AGREEMENT WITH THEIR HANDLING OF THE
FIRST 36 HOURS OF THE NEW WEATHER FORECAST FOR EASTERN KENTUCKY. THE
CONSENSUS IS FOR AN AREA OF LOW PRESSURE TO CONTINUE MOVING ACROSS
THE TENNESSEE VALLEY...INTO THE SOUTHEASTERN UNITED STATES...AND
EVENTUALLY UP THE EASTERN SEABOARD. DUE TO THE APPROACH OF A STRONG
COLD FRONT FROM THE WEST...AND THE STRENGTH OF AN AREA OF HIGH
PRESSURE THAT IS CURRENTLY PARKED OVER THE OHIO VALLEY...THE SOUTHERN
STREAM SYSTEM MENTIONED EARLIER WILL NOT BE ABLE TO MOVE FAR ENOUGH
NORTH TO SPREAD ITS PRECIPITATION INTO EASTERN KENTUCKY. THE ONE
THING THE SOUTHERN STREAM SYSTEM WILL DO IS SPREAD ITS CLOUD COVER
ACROSS THE SOUTHERN HALF OF THE FORECAST AREA THROUGH LATE THIS
EVENING. EVENTUALLY THE CLOUD COVER ASSOCIATED WITH THE APPROACHING
COLD FRONT WILL OVERSPREAD THE ENTIRE AREA FROM THE WEST LATER
TONIGHT. THE WEATHER MAKER FOR OUR AREA WILL BE THE AFOREMENTIONED
COLD FRONT. THIS BOUNDARY IS PROGGED TO MOVE ACROSS CENTRAL KENTUCKY
DURING THE DAY ON FRIDAY. AS IT DOES SO A LINE OF LIGHT RAIN SHOWERS
WILL MOVE ACROSS THE AREA WITH IT. THIS WILL BE A FAST MOVING
SYSTEM...SO THE PRECIPITATION WILL BE SHORT LIVED. COLDER AIR WILL
SPILL INTO THE AREA BEHIND THE FRONT...PAVING THE WAY FOR A FRIGID
NIGHT FRIDAY NIGHT. LOWS FRIDAY NIGHT WILL BOTTOM OUT IN THE 20S
ACROSS THE AREA...AFTER HIGHS ON FRIDAY ONLY MAKE IT INTO THE 40S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST THU FEB 7 2013
THE MODELS ARE IN PRETTY GOOD AGREEMENT CONSIDERING THE HIGHLY
AMPLIFIED PATTERN OVER THE CONUS. RIDGING THROUGH THE OHIO VALLEY
WILL GIVE WAY TO A DEEP TROUGH PINWHEELING THROUGH THE GREAT PLAINS
OVER THE WEEKEND. THIS WILL GRADUALLY LOWER HEIGHTS OVER THE AREA AS
IT BRUSHES BY KENTUCKY TO START THE NEW WORK WEEK. THE MODELS ARE
QUITE SIMILAR WITH THIS SO A CONSENSUS LOOKS REASONABLE. THE MORE
CHALLENGING PART OF THE FORECAST APPEARS TO BE FOR MID WEEK AS A
SOUTHERN STREAM TROUGH DRAGS ITS WAY THROUGH THE DEEP SOUTH. THE
MODELS HAVE A SIGNIFICANT SPREAD WHEN IT COMES TO THIS WAVE MOVING
THROUGH...JUST SOUTH OF THE AREA. THE ECMWF IS SLOWER AND A BIT
FURTHER SOUTH WITH ITS CORE ENERGY THAN THE GFS AND THE FLATTER GEM.
THE ENSEMBLES OF THE ECMWF APPEAR TO HAVE THE MORE REASONABLE
SOLUTION SPECTRUM WITH THIS IN KEEPING THE STREAMS SEPARATE UNTIL
EVERYTHING GETS EAST OF THE APPALACHIANS. ACCORDINGLY...HAVE FAVORED
A MODEL CONSENSUS THROUGH MONDAY BEFORE LEANING MORE ON THE
OPERATIONAL ECMWF FOR WEATHER SPECIFICS FOR THE LATER PARTS OF THE
EXTENDED.
SENSIBLE WEATHER WILL FEATURE LOW CLOUDS AND THE BULK OF THE MOISTURE
FROM THIS UPCOMING SYSTEM ON THE WAY OUT FOR SATURDAY AS HIGH
PRESSURE BUILDS IN. THE NEXT WEATHER MAKER COMES IN ON SUNDAY WITH
PLENTY OF WARM AIR TO MAKE THE PCPN FALL AS ALL LIQUID. THIS WETTER
SYSTEM WILL PUSH A COLD FRONT THROUGH DURING SUNDAY NIGHT WITH A
DECENT BOUT OF RAIN APPEARING LIKELY. THE COLD AIR IN THE WAKE OF
THIS WILL STAY MAINLY TO THE NORTH OF THE AREA...AS IT HAS FOR MUCH
OF THE WINTER. A WAVE WILL MOVE ALONG THE FRONT STALLED TO OUR SOUTH
ON TUESDAY INTO WEDNESDAY WITH A SMALL POTENTIAL OF RIDING CLOSE
ENOUGH TO THE AREA TO GIVE EAST KENTUCKY SOME MIXED PCPN TUESDAY
NIGHT INTO WEDNESDAY MORNING. HIGH PRESSURE FOLLOWS THIS WAVE AND
WILL DRY THE REGION BACK OUT AS FAIRLY MILD CONDITIONS CONTINUE.
THE CR GRID LOAD CAME IN A BIT HEAVY ON THE GFS SOLUTION FOR THE
LATTER PART OF THE EXTENDED WITH RESPECT TO POP AND SKY. HAVE BACKED
OFF THIS TO SOME EXTENT IN FAVOR OF THE MORE SUPPRESSED ECMWF
SOLUTION. MADE JUST SOME SMALL TERRAIN BASED TWEAKS TO THE LOW
TEMPERATURES ON SATURDAY...MONDAY...AND WEDNESDAY NIGHTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1150 PM EST THU FEB 7 2013
VFR CONDITIONS ARE GIVING WAY TO A COLD FRONT PUSHING ACROSS CNTRL KY
TONIGHT INTO FRIDAY MORNING. A BAND OF LIGHT RAIN SHOWERS WILL PUSH
EAST LATE TONIGHT. IN THE WAKE OF THE FRONT...CIGS WILL CRASH QUICKLY
WITH UPSTREAM OBS INDICATING CIGS AS LOW AS 400-600 FEET. THUS...THIS
WILL ESSENTIALLY SHUT DOWN AIRPORTS IN EASTERN KENTUCKY EARLY
THIS MORNING. SOME IMPROVEMENT IN CIGS IS ANTICIPATED TODAY...LIFTING
TO MVFR BY EARLY AFTERNOON. HOWEVER...STILL LOTS OF UNCERTAINTY AS TO
WHETHER OR NOT WE WILL CLEAR OUT. PLENTY OF STRATUS EXTENDS WELL BACK
TO THE NORTHWEST OVER IOWA AND INTO THE DAKOTAS. IF THIS CONTINUES TO
FILL IN BEHIND THE FRONT...AND HISTORICALLY A NORTHWEST FLOW TRAPS
MOISTURE IN AN UPSLOPE FLOW...THEN THE POTENTIAL CLEARING WILL BE VERY
QUESTIONABLE. THUS...LOTS OF UNCERTAINTY WITH THE CIG FORECAST AFTER
18Z TOMORROW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...AR
LONG TERM...GREIF
AVIATION...DUSTY
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1203 PM CST FRI FEB 8 2013
.AVIATION...WINDS HAVE INCREASED OUT OF THE NORTH IN THE WAKE OF A
SECONDARY COLD FRONT WHICH IS WASHING OUT AS IT MOVES THROUGH THE
ACADIANA AREA. SUFFICIENT LOW LEVEL MOISTURE IN THE WAKE OF THIS
SYSTEM HAS MIXED OUT INTO AN MVFR STRATOCU DECK. THE NAM DOES NOT
APPEAR TO HAVE A HANDLE ON THE NORTHERN EXTENT OF THE DECK WHICH
EXTENDS INTO NORTHERN LOUISIANA AS WELL AS THE TYLER AREA OF EAST
TEXAS. SOME BREAKS ARE NOTED UPSTREAM OF LCH, LFT AND ARA SO WENT
WITH VFR LATER THIS AFTERNOON FOR THOSE TERMINALS.
DUE TO THE THICKER DECK INTO CENLA, OPTED TO BLEND IN RUC AND GFS
BOUNDARY LAYER MOISTURE WHICH DELAYS VFR UNTIL THIS EVENING FOR
AEX. THE LAYER IS THINNER TO THE WEST SO WENT WITH LATER THIS
AFTERNOON FOR LCH, SUNDOWN FOR BPT.
RETURN FLOW MVFR CIGS SATURDAY MORNING INTO ALL THE TERMINALS
SOUTH OF AEX.
SWEENEY
&&
.PREV DISCUSSION... /ISSUED 859 AM CST FRI FEB 8 2013/
UPDATE...
HAD TO DO A QUICK UPDATE TO HANDLE THE MARINE FOG AHEAD OF THE
FRONT WITH VISIBILITIES STILL BETWEEN 1/4 AND 1 SM IN AREAS ACROSS
THE EASTERN ZONES OF THE COASTAL WATERS. GUIDANCE DOES SUGGEST
THAT THIS FOG WILL GRADUALLY LIFT AS IS SHIFTS TO THE EAST WITH
THE FRONT. SO HAD TO EXTEND THE ADVISORY AND EXPAND THE AREA A
BIT. WILL LIKELY BE ABLE TO TRIM THE ADVISORY WITH THE FRONT
THROUGH THE MORNING.
ALSO WILL UPDATE THE ZONES AFTER 9 AM TO MAINLY TRIM AFTERNOON
HIGHS...ESPECIALLY ACROSS THE NORTHERN TIER OF COUNTIES AND
PARISHES WITH STRONGER CAA AND THICK CLOUD COVER. WILL ALSO REMOVE
THE DENSE FOG ADVISORY FROM THE INLAND AREAS.
BRAZZELL
PREV DISCUSSION... /ISSUED 642 AM CST FRI FEB 8 2013/
UPDATE...
REMOVED CALCASIEU...THE WESTERN PORTION OF CAMERON...ACADIA AND
THE ADJACENT COASTAL WATERS ALONG CAMERON FROM THE DENSE FOG
ADVISORY AS THE FRONTAL SYSTEM HAS NOW PUSHED THROUGH AND THE
VISIBILITIES ARE IMPROVING.
PREV DISCUSSION... /ISSUED 539 AM CST FRI FEB 8 2013/
AVIATION...
FRONTAL SYSTEM HAS MOVED THROUGH SE TX THIS AM WITH VSBY COMING UP
ALTHOUGH CEILINGS REMAIN LOW AT THIS TIME. WITH THE APPROACH OF
THE FRONT IN SW LA VSBYS HAVE ALSO STARTED TO RISE AT LCH. VSBY AT
LFT AND ARA WILL BEGIN TO RISE ALTHOUGH LIKE SE TX CEILINGS WILL
BE THE LAST TO IMPROVE. EXPECTING ALL SITES TO GO VFR BY THE EARLY
AFTERNOON HOURS.
PREV DISCUSSION... /ISSUED 441 AM CST FRI FEB 8 2013/
DISCUSSION...
CURRENT ANALYSIS SHOWS COLD FRONT BEGINNING TO MOVE ACROSS INLAND
SE TX THRU W LA. AREAS OF DENSE FOG CONTINUE TO FORM AHEAD OF THE
FRONT MAINLY ACROSS THE I-10 CORRIDOR OF S LA...AND THE COASTAL
LAKES/BAYS AND NEAR SHORE WATERS. THUS...HAVE ISSUED A DENSE FOG
ADVISORY THRU 15Z FOR THIS AREA...ALTHOUGH AREAS ACROSS SW LA
COULD BE LIFTED EARLIER AS THE FRONT CONTINUES SE THIS MORNING.
LIMITED DEEP LAYER MOISTURE WITH THIS FROPA WILL PROHIBIT ANY
CONVECTION. ALSO NOT EXPECTING MUCH CHANGE IN TEMPS...AS THE MAIN
EMPHASIS OF THE HIGH WILL BE WELL N AND E OF THE AREA. CLOUD COVER
IS EXPECTED TO DECREASE BEHIND THE FRONT...BUT PROBABLY AT BEST
PARTLY CLOUDY BY AFTERNOON ALLOWING TEMPS TO RISE INTO THE UPPER
60S TO NEAR 70.
THE PARTIAL CLEARING WILL BE VERY SHORT LIVED...AS CLOUD COVER
WILL INCREASE ONCE AGAIN DURING THE EVENING AND OVERNIGHT HOURS
SAT AS THE NEXT UPPER LEVEL STORM SYSTEM (CURRENTLY OVER THE WEST
COAST) APPROACHES THE REGION. IT LOOKS LIKE INITIATION OF THIS
MULTI-DAY PRECIP EVENT WILL GET OFF WITH A BANG AS A FAIRLY
SIGNIFICANT SHORTWAVE MOVES THROUGH THE REGION. AS MENTIONED
YESTERDAY AFTERNOON...A 40-50 KT LLJ WILL ACCOMPANY THE
SIGNIFICANT MOISTURE POOLING AND LIFT...IN WHAT LOOKS LIKE A
SQUALL LINE TO MOVE THRU SUN MORNING INTO THE EARLY AFTERNOON
HOURS. SPC HAS ENTIRE AREA OUTLINED IN SLIGHT RISK FOR SVR
TSTMS...MAINLY FOR POSSIBLE SUPER CELLS...AND OF COURSE...DAMAGING
WINDS LIKELY WITH THIS SQUALL LINE.
THE MAIN STORM SYSTEM WILL REMAIN WELL NE OF THE REGION...LEAVING
A NEARLY STATIONARY FRONTAL BOUNDARY OVER OUR REGION THRU TUE.
WITH THE FLOW ALOFT REMAINING SW...SEVERAL PERTURBATIONS MOVING NE
WITHIN THIS FLOW WILL KEEP HEALTHY CHANCES OF SHRA/TSRA THRU TUE.
GFS/ECMWF CONTINUE IN BETTER AGREEMENT IN ENDING THE SHRA/TSRA BY
TUE AFTERNOON.
DML
MARINE...
A WEAK COLD FRONT WILL TRAVEL SOUTHEAST THROUGH THE COASTAL
WATERS THIS MORNING...WITH AREAS OF DENSE FOG FORMING AHEAD OF IT
ACROSS THE INLAND LAKES AND BAYS...AND COASTAL WATERS OUT 20
NAUTICAL MILES. THE FOG IS EXPECTED TO LIFT AFTER THE FRONTAL
PASSAGE LATER THIS MORNING. THE NEXT CHANCE OF PRECIPITATION IS
EXPECTED BY SATURDAY NIGHT THROUGH TUESDAY AS A SERIES OF UPPER
LEVEL DISTURBANCES AFFECT THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 69 50 67 61 74 / 10 10 10 30 40
KBPT 69 51 67 62 74 / 10 10 10 30 30
KAEX 64 44 66 58 74 / 10 10 10 30 80
KLFT 69 49 69 61 76 / 10 10 10 20 50
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM LOWER ATCHAFALAYA
RIVER TO INTRACOASTAL CITY LA OUT 20 NM...WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
616 AM EST FRI FEB 8 2013
.SYNOPSIS...
LOW PRESSURE WILL BRING A WINTRY MIX OF PRECIPITATION NORTH OF
PITTSBURGH THIS MORNING. A COLD FRONT WILL CROSS THE AREA
TODAY...WITH RAIN CHANGING TO SNOW THIS AFTERNOON AND EVENING.
HIGH PRESSURE WILL THEN BUILD IN FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL TONIGHT/...
AN UPDATE HAS BEEN ISSUED THIS MORNING TO ADD THE SLIGHT CHANCE OF
FREEZING RAIN FOR THE PITTSBURGH METRO AND NORTHWARD.
THE LATEST RAP SURFACE ANALYSIS INDICATES A 1008MB LOW CENTERED
ACROSS NORTHERN OHIO. A COLD FRONT EXTENDS FROM THIS FEATURE
SOUTHWARD ACROSS CENTRAL OHIO. ALONG THE FRONT...RAIN SHOWERS ARE
PUSHING INTO EASTERN OHIO. THE UPPER OHIO VALLEY IS CURRENTLY IN A
SOUTHEASTERLY FLOW AHEAD OF THIS FEATURE WITH SFC TEMPS RANGING
FROM THE LOWER 30S ALONG FRANKLIN-DUBOIS LINE TO THE UPPER 30S
SOUTH OF INTERSTATE 70. SOME ROAD SENSORS ARE BELOW FREEZING
ACROSS THE PIT METRO AND NORTHWARD.
TODAY...THE COLD FRONT WILL SLIDE EASTWARD ACROSS THE UPPER OHIO
VALLEY...BRINGING MOSTLY RAIN THIS MORNING. THE EXCEPTION WILL BE
NORTH OF INTERSTATE 80...WHERE A WINTRY MIX OF SNOW...FREEZING
RAIN...AND RAIN WILL BE POSSIBLE. BASED ON RECENT SURFACE OBS
ALONG WITH LAMP/HRRR TEMP GUIDANCE...A FEW HUNDREDTHS OF AN INCH
OF ICE ARE IN THE FORECAST THERE. THERE IS STILL MORE UNCERTAINTY
AS TO HOW ROAD SURFACES WILL RESPONSE JUST AHEAD OF THE FRONT...AS
SOME ARE BELOW FREEZING. THIS WILL NEED TO BE MONITORED CLOSELY AS
FREEZING RAIN CANNOT BE RULED OUT FOR THE PIT METRO AND NORTHWARD.
SURFACE WAA SHOULD BE STRONG ENOUGH FOR PRECIP TO MOSTLY CHANGE
TO RAIN FOR A FEW HOURS IN THE LATE MORNING UNTIL CAA KICKS BACK
IN BEHIND THE FRONT THIS AFTERNOON.
BEHIND THE FRONT THIS EVENING AND TONIGHT...A MODEL CONSENSUS IS IN
AGREEMENT THAT STRONG CAA WILL ENSUE WITH TEMPS FALLING THIS
AFTERNOON AND PRECIP CHANGING OVER TO ALL SNOW. WITH LITTLE PRECIP
ANTICIPATED BEHIND THE FRONT...MOST SNOW ACCUMULATION THIS
AFTERNOON AND EVENING WILL BE CONFINED TO THE I-80 CORRIDOR AND
NORTHWARD WITH 1 TO 3 INCHES THERE.
HI-RES NMM/ARW MODELS ARE NOW SHOWING BETTER POTENTIAL FOR AN
UPSLOPING EVENT BEGINNING THIS EVENING FOR THE LAUREL HIGHLANDS
AND ALLEGHENY FRONT OF WV/PA/MD. HAVE INCREASED SNOWFALL AMOUNTS
TO 2 TO 4 INCHES IN PA AND 3 TO 6 IN WV/MD. IN ADDITION...WINDS
HAVE BEEN INCREASED TO JUST BELOW WIND ADVISORY CRITERIA FOR THE
RIDGES AS A TIGHTENED PRESSURE GRADIENT SETS UP THIS EVENING
BETWEEN THE COASTAL LOW STRENGTHENING EAST OF THE AREA AND A
SURFACE HIGH BEGINNING TO APPROACH FROM THE WEST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
A MODEL CONSENSUS INDICATES THAT A BROAD MID-LEVEL RIDGE ALONG WITH
A SURFACE HIGH WILL BUILD IN FROM THE WEST ON SATURDAY AND CROSS THE
UPPER OHIO VALLEY ON SUNDAY. ANY LINGERING MOISTURE ON THE WESTERN
PERIPHERY OF THE COASTAL LOW WILL BE PULLED EAST OF THE RIDGES BY
15Z SATURDAY WITH SUBSIDENCE MOVING INTO THE REGION BRINGING AN END
TO UPSLOPING. THEREAFTER...A DRY FORECAST IS IN PLACE THROUGH THE
WEEKEND.
RIDGING AND DRIER AIR BUILDING IN WILL BRING ABUNDANT SUNSHINE ON
SATURDAY...WITH TEMPS RESPONDING FAIRLY QUICKLY DESPITE A NORTHERLY
FLOW IN PLACE. FOR TEMPS SATURDAY...HAVE GONE A FEW DEGREES ABOVE
THE WARMER MAV...WITH HIGHS RANGING FROM THE MID 20S ACROSS THE I-80
CORRIDOR TO THE MID 30S IN NORTH-CENTRAL WV AND PORTIONS OF EASTERN
OHIO. WITH THE SURFACE HIGH MOVING JUST EAST OF THE AREA SATURDAY
NIGHT...A STRONG RADIATIONAL COOLING NIGHT LOOKS TO BE IN STORE
ALTHOUGH ONE LIMITING FACTOR COULD BE HIGH CIRRUS SLIDING INTO THE
AREA AHEAD OF THE NEXT FRONTAL SYSTEM APPROACHING FROM THE WEST.
HAVE FAVORED MORE RADITIONAL COOLING EAST OF PITTSBURGH FOR LOWS SAT
NIGHT. LOWS WILL RANGE FROM THE SINGLE DIGITS NORTHEAST OF
PITTSBURGH TO THE MID 20S IN PORTIONS OF EASTERN OHIO.
SURFACE HIGH WILL SHIFT FURTHER EAST OF THE AREA WITH RIDGE BECOMING
CENTERED ACROSS THE REGION ON SUNDAY. THIS WILL ALLOW FOR THE
LOW-LEVEL FLOW TO BECOME MORE SOUTHERLY AND WAA WILL BE ENHANCED
AHEAD OF AN APPROACHING COLD FRONT FROM THE WEST. IN
ADDITION...CLOUD COVERAGE WILL BE INCREASING THROUGHOUT THE DAY
AHEAD OF THE FRONT. HIGHS SUNDAY FAVOR THE WARMER ECMWF...RANGING
FROM THE UPPER 30S ACROSS THE I-80 CORRIDOR AND EASTERN RIDGES TO
THE UPPER 40S IN PORTIONS OF EAST-CENTRAL OHIO AND NORTHERN WV.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
INITIALLY DRY WEATHER WILL DETERIORATE AS LOW PRES DVLPS TWD THE
GREAT LAKES SUNDAY NGT.
HIGH AMPLITUDE CNTRL CONUS TROF IS PROGGED TO SLIDE EWD AS MID
WEEK APPROACHES...HENCE TEMPS SHOULD FADE BACK TWD THE SEASONAL
AVERAGES. HOWEVER...POPS WL BE DEPENDENT ON TIMING OF SHRTWVS
MOVING THROUGH THE SWLY FLOW ON THE ERN FLANK OF THAT TROF. HAVE
THUS FORECASTED LATE TUESDAY THRU THURSDAY POPS NR CHC CLIMO NMBRS
FOR NOW.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR AND LIGHT E-SE WINDS ARE EXPECTED OVERNIGHT...EXCEPT FOR LBE...
MGW AND DUJ...WHERE DOWNSLOPING WINDS COULD BRING GUSTS AROUND 20
KTS. COLD FRONT WILL BRING PRECIPITATION LATER THIS MORNING INTO THE
AFTERNOON HOURS. FKL AND DUJ WILL LIKELY SEE PERIODS OF SNOW AND
FREEZING RAIN. AT ALL OTHER TAF SITES...EXPECT THAT PRECIPITATION
SHOULD BEGIN AS RAIN AND CHANGE OVER TO SNOW AS FRONT BRINGS IN
COLDER AIR LATER IN THE AFTERNOON. WINDS WILL VEER TO THE WEST AND
BECOME GUSTY BEHIND THE FRONT...WITH THE POTENTIAL FOR SNOW SHOWERS
CONTINUING TO THE NORTH AT FKL/DUJ AND ALONG HIGHER ELEVATION AT
LBE/MGW.
.OUTLOOK.../TONIGHT THROUGH TUESDAY/...
MVFR RESTRICTIONS WILL CONTINUE MOST OF TONIGHT...WITH HIGH
PRES BRINGING A RETURN TO VFR FOR THE WEEKEND. ANOTHER LOW IS
FORECAST TO BRING WIDESPREAD RESTRICTIONS SUNDAY NGT AND MONDAY.
RESTRICTIONS MAY CONTINUE IN LAKE EFFECT SHOWERS MONDAY NIGHT AND
TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 1 AM EST SATURDAY FOR PAZ008-009-
015-016.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
742 PM EST SAT FEB 9 2013
.SYNOPSIS...
ISSUED AT 420 PM EST SAT FEB 9 2013
HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER ACROSS THE
REGION THROUGH EARLY SUNDAY. BEYOND THAT...A STORM SYSTEM WILL
ORGANIZE OVER THE PLAINS STATES AND PUSH NORTHEAST TOWARDS THE GREAT
LAKES. THIS WILL BRING A WINTRY MIX OF RAIN...SNOW...SLEET...AND
FREEZING RAIN TO THE REGION BY LATE SUNDAY AND SUNDAY NIGHT.
PRECIPITATION WILL CHANGE TO ALL SNOW ON MONDAY AS COOLER AIR MOVES
BACK INTO THE REGION. MAINLY QUIET WEATHER WILL RETURN FOR THE
MIDDLE PORTION OF NEXT WEEK...WITH SEASONAL TEMPERATURES EXPECTED.
&&
.UPDATE...
ISSUED AT 742 PM EST SAT FEB 9 2013
MADE SOME EARLY TWEAKS TO FORECAST. COMBINATION OF SHALLOW LAKE
CLOUDS OVER LAKE MICHIGAN AND PATCHY MID LEVEL AC WILL TEND TO
KEEP EASTERN UPPER ON THE CLOUDY SIDE OVERNIGHT (ASSUMING LAKE
MICHIGAN CLOUDS GET ADVECTED EASTWARD A BIT). AT THE SAME TIME...
CURRENTLY NOT AS CONCERNED WITH LOW CLOUDS SPILLING INTO NORTHWEST
LOWER WITH STRENGTHENING SOUTHEAST SURFACE FLOW OVER THE LOWER
PENINSULA. BOTH RAP AND NAM-WRF HAVING BOUNDARY LAYER ISSUES...RAP
FORECAST SOUNDINGS TOO COLD (SUGGESTING IT SHOULD ALREADY BE IN
THE MID TEENS AT GLR/GOV/CAD WHEN IN REALITY TEMPERATURES ARE 8-10F
WARMER)...AND NAM-WRF SOUNDINGS ARE TOO MOIST. THINK THERE WILL BE
ENOUGH OF A GRADIENT TO KEEP THINGS FROM DE-COUPLING AND RADIATING
LIKE MAD. SO HAVE NUDGED TEMPERATURE TRENDS UP A BIT (AND MINIMUM
TEMPERATURES BY EXTENSION).
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 420 PM EST SAT FEB 9 2013
ELONGATED SFC RIDGE AXIS JUST OFF TO THE EAST OF THE STATE THIS
AFTERNOON WITH SOUTHERLY RETURN FLOW STRENGTHENING ACROSS THE
STATE. ABUNDANT SUN ACROSS NRN LOWER MICHIGAN TODAY. REMAINING LAKE
CLOUDS OVER LAKE MICHIGAN STILL STILL JUST OFFSHORE OF LOWER
MICHIGAN BUT SHOWING A LITTLE SIGN OF INCHING BACK TOWARD SHORE.
UPPER MICHIGAN GETTING RIPPED OFF HOWEVER...AS SOUTHERLY MEAN LOW
LEVEL WIND IS DRAGGING LAKE CLOUDS UP THROUGH A GOOD PART OF EASTERN
UPPER. KERY REPORTED 5SM -SN ABOUT TWO HOURS AGO. SO...STILL
GETTING SOME SHALLOW NUISANCE LAKE SNOWS.
TONIGHT...MORE NUISANCE STUFF TO WORRY ABOUT THAN ANYTHING. LAKE
CLOUDS OVER SRN LAKE MICHIGAN ARE STARTING TO ERODE FROM THE SOUTH
AS WARMER LOW LEVEL AIR MAKES ITS WAY UP THE LAKE. HOWEVER...STILL A
WINDOW OF OPPORTUNITY TO GET SOME LAKE CLOUDS INTO THE PARTS OF NW
LOWER MICHIGAN THIS EVENING AS WE GET MORE OF A WESTERLY COMPONENT
TO THE WIND...ALTHOUGH REMAINING LAKE CLOUDS SHOULD FURTHER ERODE
AWAY FROM THE SOUTH AS WARMER LOW LEVEL AIR WORKS INTO REGION.
SECOND PROBLEM IS STRATUS AND/OR FOG POTENTIAL. AS WE GET MORE OF A
WESTERLY COMPONENT OFF LAKE MICHIGAN...FORECAST SOUNDINGS SHOW
ADDITIONAL MOISTURE GETTING PULLED INTO NRN LOWER MICHIGAN THROUGH
THE NIGHT (DEW POINT TRACE FOLDS OVER-TOP THE BOUNDARY LAYER). THIS
SUGGESTS THE POSSIBILITY OF DEVELOPMENT OF LOW STRATUS AND/OR FOG AS
WARM/MOIST LAYER ALOFT ADVECTS OVER A COLD BOUNDARY LAYER. DIDN`T GO
MOSTLY CLOUDY...BUT DO HAVE AN INCREASE IN CLOUD COVER (PARTLY
CLOUDY) THIS EVENING.
TEMPS...YET ANOTHER ISSUE. HAVE MAINLY CLEAR SKIES INTERIOR GOING
INTO THE EVENING WHICH WILL ALLOW TEMPS TO DROP QUICKLY AGAIN. BUT
TEMP FREE-FALL WILL BE THROTTLED COMPARED TO LAST NIGHT BY STRONGER
FLOW OFF THE SFC. DON`T FORESEE BELOW ZERO READINGS TONIGHT GIVEN THE
STRONGER WINDS AND CLOUD POTENTIAL...BUT SOME OF THE COLDER SPOTS
DIPPING INTO THE SINGLE DIGITS CERTAINLY NOT OUT OF THE
QUESTION.
SUNDAY...ANY CIGS/FOG WILL ERODE DURING THE MORNING HOURS AS WARMER
AIR CONTINUES TO WORK INTO THE REGION. NEXT WEATHER MAKER WILL BE
WORKING INTO THE MIDWEST THROUGH THE COURSE OF THE DAY. STRONG PULSE
OF WARM ADVECTION EXPECTED TO PUSH PRECIP UP THROUGH THE STATE...
GENERALLY BETWEEN THE 21Z AND 00Z TIME FRAME (MODEL CONSENSUS IS
PRETTY CLOSE)...WHICH SEEMS REASONABLE GIVEN THE VERY DRY AIR IN
PLACE DOWNSTAIRS INITIALLY. BUT ONCE AGAIN...WARM NOSE ALOFT
ROCKETING INTO THE REGION WILL ALSO BRING ANOTHER ROUND OF P-TYPE
ISSUES TO NORTHERN MICHIGAN. COLD TEMPS TO START AND SFC TEMPS JUST
INCHING TO AROUND THE FREEZING MARK WILL PRESENT A RAIN/FREEZING
RAIN PROBLEM OVER THE HIGH TERRAIN/NE LOWER MICHIGAN. SNOW/SLEET/
FREEZING RAIN MIX IN EASTERN UPPER WITH SLIGHTLY COLDER AIR ALOFT.
DON`T THINK WE GET WARNING CRITERIA PRECIP OF ANY TYPE. BUT MAY
ULTIMATELY NEED SOME ADVISORIES ISSUED...BUT WILL ALLOW LATER SHIFTS
TO TAKE CARE OF THAT.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 420 PM EST SAT FEB 9 2013
PROGRESSIVE PATTERN SET TO CONTINUE...COURTESY OF ONE AGITATED
PACIFIC PATTERN (WHICH WATER VAPOR IMAGERY SHOWS COVERED WITH A
VIRTUAL WAVE-TRAIN OF STRONG TROUGH/RIDGE COUPLETS) AND LACK OF ANY
DOWNSTREAM NORTH ATLANTIC BLOCKING. THIS AGGRESSIVE FLOW WILL HELP
KICK OUT CURRENT FOUR-CORNERS WAVE...WHICH WILL CUT ACROSS THE
NORTHERN LAKES SUNDAY NIGHT INTO MONDAY...BRINGING A PLETHORA OF
DIFFERENT WEATHER TYPES. PLENTY OF SUPPORT FOR A MUCH TAMER PERIOD
OF WEATHER HEADING THROUGH THE MIDDLE OF NEXT WEEK AS AREA BECOMES
CENTERED BETWEEN ACTIVE STORM TRACKS. FORECAST CONCERNS CONTINUE TO
FOCUS ON WEATHER TYPES AND POTENTIAL IMPACTS FROM SUNDAY NIGHT AND
MONDAYS SYSTEM.
AGGRESSIVE PUSH OF WAA/ISENTROPIC UPGLIDE ON NOSE OF 50+ KNOT LOW
LEVEL JET WILL RACE ACROSS THE AREA SUNDAY EVENING...ACCOMPANIED BY
AN AREA OF MODERATE PRECIP. WAA NOT AS AGGRESSIVE AT THE
SURFACE...ALTHOUGH STOUT OFF THE DECK WARM NOSE ENSURES ANYTHING
REACHING THE SURFACE ACROSS NORTHERN LOWER WILL BE OFF THE LIQUID
VARIETY. SOME LINGERING NEAR FREEZING AREAS/COLD SKIN TEMPERATURES
MAY CONTINUE TO RESULT IN POCKETS OF FREEZING RAIN ACROSS THE
INTERIOR HIGHLANDS DURING THE EARLY EVENING...WITH PLAIN RAIN
FALLING ELSEWHERE. EVAP COOLING ALLOWS COLUMN TEMPERATURES TO
STRADDLE THE FREEZING LINE NORTH OF THE BRIDGE...SUGGESTING
PRIMARILY A SNOW OR SNOW/SLEET MIXTURE AS STEADIEST/HEAVIEST PRECIP
ARRIVES. WHILE SNOW TO LIQUID RATIOS WILL REMAIN LOW...A SEVERAL
HOUR PERIOD OF POTENTIALLY HEAVY SNOWFALL RATES WILL LIKELY PRODUCE
A FEW INCHES (2 TO 5) ACROSS INTERIOR EASTERN UPPER. STRONG
SHORTWAVE AND ATTENDANT SURFACE LOW PIVOT INTO CENTRAL UPPER
MICHIGAN BY MONDAY MORNING...ALLOWING A PRETTY RESPECTABLE MID LEVEL
DRY SLOT TO OVERSPREAD NORTHERN LOWER MICHIGAN. THIS SHOULD BRING
MORE OF A VERY LIGHT RAIN/DRIZZLE SCENARIO OVERNIGHT. MOISTURE
REMAINS DEEPER NORTH OF THE STRAITS ALONG AND NORTH OF SURFACE WARM
FRONT. SNOW/SLEET MIXTURE SHOULD TRANSITION MORE TO A
RAIN/SLEET/FREEZING RAIN/SNOW MIXTURE AS 900MB CENTERED WARM NOSE
INCREASES TO +2C...WITH JUST MINIMAL ADDITIONAL SNOW ACCUMULATIONS
AFTER MIDNIGHT.
SYSTEM CONTINUES TO OCCLUDE/WEAKEN AS IT PUSHES OFF INTO CANADA
LATER MONDAY AND MONDAY NIGHT. DRY SLOT FOLLOWS SUITE...WITH DEEPER
MOISTURE ALONG SECONDARY TROUGH AXIS PUSHING INTO THE REGION THROUGH
THE DAY. BACKSIDE CAA NOT NEARLY AS AGGRESSIVE...SUGGESTING A SLOWER
TRANSITION BACK TO SNOW THAN WHAT IT APPEARED LIKE YESTERDAY. COLD
LAYER DEEPENS ENOUGH TO SUPPORT PRIMARILY SNOW BY LATE
AFTERNOON...WITH SOME MINOR (SUB ONE INCH) ACCUMULATIONS
POSSIBLE...ESPECIALLY WHERE WEST FLOW UPSLOPE IS MAXIMIZED INTO THE
HIGHLANDS. REAL MARGINAL CONDITIONS FOR NW-WNW LAKE ENHANCEMENT
MONDAY NIGHT WITH DELTA T/S FLIRTING WITH 13C AND INVERSION LEVELS
AT H85 LEVEL. PERHAPS AN ADDITIONAL INCH OF SNOW IN FAVORED
AREAS...OTHERWISE JUST SOME SCATTERED LIGHT SNOW SHOWERS AND
FLURRIES.
OTHER THAN SOME LINGERING LIGHT SNOW SHOWERS TUESDAY MORNING...JUST
NOT A WHOLE LOT TOO TALK ABOUT HEADING INTO THURSDAY AS NORTHERN
LAKES BECOMES CENTERED BETWEEN NORTHERN AND SOUTHERN STREAM WAVES.
IMAGINE A FEW FLURRIES/LIGHT SNOW SHOWERS ARE POSSIBLE LATER
WEDNESDAY INTO WEDNESDAY NIGHT AS SOUTHERN PORTION OF NORTHERN WAVE
SWEEPS ACROSS...BUT NOT WORTHY OF A SPECIFIC MENTION IN THIS
FORECAST. POTENTIAL FOR A STRONGER HYBRID CLIPPER TYPE SYSTEM TO
ARRIVE TO END THE EXTENDED...BRINGING ADDITIONAL LIGHT SNOW CHANCES.
TEMPERATURES TO AVERAGE NEAR TO ABOVE NORMAL WEDNESDAY THROUGH
FRIDAY...WITH A SHOT OF COOLER AIR ARRIVING TO START NEXT WEEKEND
(SUBJECT TO MANY CHANGES...OF COURSE).
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 651 PM EST SAT FEB 9 2013
VFR CONDITIONS EXPECTED TONIGHT WITH LOW LEVEL WIND SHEAR THROUGH
ABOUT 09Z-12Z. CLOUDS WILL THICKEN AND LOWER SUNDAY...WILL SEE
PRECIPITATION MOVE INTO TVC/PLN DURING THE AFTERNOON HOURS...
POSSIBLY BEGINNING AS FREEZING RAIN WITH SURFACE TEMPERATURES
EXPECTED RIGHT AROUND 32F.
&&
.MARINE...
ISSUED AT 420 PM EST SAT FEB 9 2013
SOUTHERLY WINDS WILL INCREASE TONIGHT AND FURTHER THROUGH THE DAY SUNDAY
IN ADVANCE OF ANOTHER LOW PRESSURE SYSTEM THAT WILL TRACK THROUGH
THE NRN LAKES LATE SUNDAY INTO MONDAY. AT THIS POINT...WITH WARMING
TEMPS OVER THE LAKES/INCREASING LAKE STABILITY...DON`T THINK WIND
GUSTS WILL REACH GALE FORCE WITH THIS SYSTEM. HOWEVER...A HANDFUL
OF SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR SUNDAY AND
SUNDAY NIGHT.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JPB
SYNOPSIS...NTS
SHORT TERM...TBA
LONG TERM...MSB
MARINE...TBA
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1151 PM EST THU FEB 7 2013
.AVIATION...
//DISCUSSION...
SNOW WILL BE ONGOING AT THE BEGINNING OF THE FORECAST PERIOD WITH
GENERAL VSBYS BETWEEN 1/2SM AND 1 1/2SM WITH POCKETS OF HEAVY SNOW
PRODUCING 1/4SM DURING THE FIRST FEW HOURS OF THE FORECAST. AFTER
09Z OR SO...SNOW WILL DIMINISH IN INTENSITY...BUT CONTINUE INTO
FRIDAY MORNING BEFORE ENDING ALTOGETHER. KYIP/KDTW/KDET MAY STILL
SEE A BRIEF PERIOD OF -FZRAPLSN MIX AS THE FORECAST BEGINS @ 06Z.
CIGS WILL FALL TO IFR/LIFR IN HEAVIEST SNOW BEFORE LIFTING TO MVFR
ON FRIDAY IN LIGHTER SNOW AND THEN SCATTERING OUT BY THE END OF THE
FORECAST AS DRIER NORTHWEST FLOW WORKS INTO AREA IN WAKE OF STORM
SYSTEM.
FOR DTW...A FEW HOUR PERIOD OF MODERATE TO POSSIBLY HEAVY SNOW WILL
MORE THAN LIKELY BRING A QUICK INCH OR TWO OF ACCUMULATION EARLY IN
THE FORECAST WITH PERHAPS A BIT OF -FZRA/PL MIXED IN WITH JUST LIGHT
SNOW EXPECTED LATER TONIGHT INTO EARLY FRIDAY MORNING AS DRY SLOT
LIMITS DEPTH OF MOISTURE.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE OF CEILINGS 5000 FEET OR LOWER THROUGH 00Z FRIDAY
EVENING.
* MODERATE CONFIDENCE OF VISIBILITIES AT 1/2 MILE IN SNOW FROM 06Z
TO 08Z.
* LOW CONFIDENCE IN SNOW STARTING OFF MIXED WITH FREEZING RAIN OR
SLEET.
&&
.PREV DISCUSSION...ISSUED 854 PM EST THU FEB 7 2013
UPDATE...
NO CHANGES TO ONGOING HEADLINES FOR TONIGHT/FRIDAY MORNING.
FORECAST IS IN REASONABLY GOOD SHAPE AS MID LEVEL FGEN COINCIDING
WITH WARNING AREA HAS STEADILY STRENGTHENED DURING THE EVENING WITH
INCREASED MOISTURE PROVIDING A STEADY EXPANSION OF SNOW SINCE
23Z-00Z OR SO. JUST LOWERED INITIAL SNOW ACCUMULATIONS SLIGHTLY AS
WEDGE OF DRY AIR EVIDENT ON KDTX 00Z SOUNDING CENTERED AROUND 800 MB
DELAYED ONSET OF STEADIER SNOW BY A FEW HOURS. STILL...TOTALS WILL
BE CLOSE TO 6 INCHES IN MANY AREAS AS SNOW CONTINUES
OVERNIGHT...FIRST ALONG THE H7 FRONT AND THEN AS DEFORMATION DRAGS
EAST WITH THE PASSAGE OF THE STORM SYSTEM. LOCAL POCKETS OF 8 INCHES
STILL REMAIN POSSIBLE OVER THE THUMB BY LATE FRIDAY MORNING AS SOME
ENHANCEMENT TO SNOWFALL RATES OCCUR AS NORTHEAST FLOW SETS UP OFF OF
LAKE HURON.
FURTHER SOUTH...AN ABRUPT START TO SNOW IS STILL EXPECTED IN THE
ADVISORY AREA...GENERALLY AROUND MIDNIGHT. DECENT RETURNS ON KDTX
88D HAVE STEADILY WORKED DOWN FROM AROUND 8KFT TO 4KFT OVER THE
PAST SEVERAL HOURS...WITH THE FINAL 4KFT EXPECTED TO SATURATE EVEN
FASTER AS HEAVY BURST OF PRECIPITATION...NOW OVER SOUTHWEST LOWER
MICHIGAN...WORKS INTO THE AREA.
INITIAL OBSERVATIONS WITH THIS POCKET OF HEAVIER SNOW BASICALLY
SUPPORT MODEL CONSENSUS OF PRECIPITATION RATES OF 0.1+"/HR OR NEAR
ONE INCH PER HOUR SNOWFALL RATES. REGIONAL RADAR LOOPS SUGGEST THIS
BURST WILL LAST 3 TO MAYBE 4 HOURS...SUPPORTING THE 2 TO 4 INCHES
OF SNOW FORECAST IN THAT TIME FRAME. CURRENT OBSERVATIONS SUGGEST
THE TRANSITION LINE BETWEEN SNOW AND A SNOW/SLEET/FREEZING RAIN
MIX WILL BE VERY CLOSE TO I-94...SO OVERALL ACCUMULATIONS WILL BE
SLIGHTLY LESS FROM THE SOUTHERN METRO DETROIT AREA SOUTH...GENERALLY
1 TO 3 INCHES.
WHILE INTENSITY DOES DIMINISH AFTER 4 AM...LIGHT TO OCCASIONALLY
MODERATE SNOW WILL CONTINUE TO AFFECT MANY AREAS OVERNIGHT INTO
EARLY FRIDAY AS DEFORMATION ZONE TRAVERSES MUCH OF THE AREA...WITH
DRY SLOT ALONG THE SOUTHERN EDGE OF THIS LIFT MAINLY AFFECTING
AREAS SOUTH OF I96...FURTHER LIMITING OVERALL ACCUMULATIONS OVER
THE FAR SOUTHERN CWA.
PREV DISCUSSION...ISSUED 330 PM EST THU FEB 7 2013
SHORT TERM...THIS EVENING THROUGH FRIDAY
COMPACT WAVE ALONG THE SOUTHERN PERIPHERY OF THE NORTHERN STREAM IS
CLIPPING EAST/SOUTHEAST THROUGH THE WESTERN GREAT LAKES THIS
AFTERNOON. LOWER TROPOSPHERIC FLOW HAS INCREASED IN ADVANCE OF THIS
FEATURE ALONG THE MID-MISSISSIPPI VALLEY MANIFESTING IN A BROAD
REGION OF RAIN ACROSS ILLINOIS SOUTH INTO ARKANSAS WITH SNOW
SPREADING ACROSS WISCONSIN AND FAR WESTERN LOWER MICHIGAN.
MID-LEVEL FORCING REMAINS IN PLACE ACROSS THE SAGINAW VALLEY /AS
EVIDENCED BY LOW-LEVEL WATER VAPOR IMAGERY/ WAITING FOR MOISTURE
TRANSPORT TO ARRIVE. EXPECTING SATURATION TO OCCUR WITHIN THIS ZONE
OF FORCING BY SUNDOWN...AFTER WHICH ACCUMULATING SNOWFALL WILL
QUICKLY FOLLOW.
MEANWHILE...THE WELL ESTABLISHED MOISTURE PLUME IS WAITING ON THE
UPPER-LEVEL PV ANOMALY OVER MINNESOTA TO LINK UP AND SHOULD BEGIN TO
BREAK TOWARD THE EAST THIS EVENING. CONSEQUENTLY...THE ONSET OF
MEANINGFUL SNOW SOUTH OF THE SAGINAW VALLEY WILL BE DURING THE LATE
EVENING HOURS AS THE WARM/MOIST CONVEYOR BELT FINALLY ARRIVES. IN
FACT...THE 07.18 RAP SUGGESTS PRECIPITATION ONSET WILL BE LAGGING
UNTIL AROUND MIDNIGHT IN MANY LOCATIONS. FURTHERMORE...12Z GUIDANCE
SUITE IS TOO BULLISH ON PRECIPITATION DURING THE FIRST 12 HOURS OF
THE FORECAST...OWING TO THE LACK OF DEEP MOISTURE TRANSPORT THUS FAR.
THE DURATION OF THE EVENT WILL CERTAINLY LIMIT ACCUMULATIONS SOUTH
OF THE MID-LEVEL FRONTAL FORCING...WHERE THE PRIMARY MECHANISM WILL
BE A QUICK BUT STRONG SHOT OF ISENTROPIC ASCENT ASSOCIATED WITH THE
SHARPENING MID-LEVEL ANOMALY. STILL EXPECT A GOOD BURST OF
PRECIPITATION /SNOW RATES IN THE INCH PER HOUR NEIGHBORHOOD/ GIVEN
THE SYSTEM WILL STILL BE DEEPENING AS IT TRAVERSES THE SOUTHERN
LAKES REGION. TO ADD FUEL TO THE RATES...THERE IS STILL THE
POTENTIAL FOR SOME CONVECTIVE CONTRIBUTION CLOSER TO THE 850MB LOW
TRACK...WHERE DIFFERENTIAL ADVECTIONS WILL DESTABILIZE THE PROFILE.
STILL PLENTY OF EVIDENCE TO SUPPORT A MIXTURE OF PRECIPITATION TYPES
ACROSS THE METRO DETROIT REGION SOUTH TO THE OHIO BORDER. THE BEST
OPPORTUNITY FOR FREEZING RAIN AND SLEET WILL BE NEAR THE ONSET OF
PRECIPITATION...BEFORE THE COLUMN SUCCUMBS TO COOLING VIA STRONG
ASCENT ALONG THE LEAD EDGE OF THE PV ANOMALY.
ON FRIDAY...SOME LIGHT SNOW WILL CONTINUE THROUGH THE MORNING AS
MID-LEVEL DEFORMATION LINGERS FOR SEVERAL HOURS. CLOSER TO LAKE
HURON...THE INCREASING NORTHEASTERLY FLOW WILL HELP BOOST SNOW
TOTALS ALONG THE IMMEDIATE LAKESHORE.
HIGH PRESSURE WILL QUICKLY BUILD INTO THE REGION BY LATE FRIDAY AND
TEMPERATURES WILL HOVER IN THE 20S MOST OF THE DAY UNDER THE
INFLUENCE OF MODEST COLD ADVECTION.
LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY
HIGH PRESSURE AT THE SURFACE AND UPPER RIDGING ALOFT WILL SLIDE
ACROSS MICHIGAN FRIDAY NIGHT THROUGH EARLY SUNDAY...BRINGING CALMER
WEATHER TO THE AREA. WARMER AND MUCH DRIER AIR ALOFT WILL START TO
PUSH IN BY FRIDAY EVENING...EFFECTIVELY LOWERING INVERSION HEIGHTS
AND STRIPPING AWAY ICE NUCLEI...ENDING POTENTIAL FOR LAKE EFFECT
SNOW TO AFFECT THE THUMB. DECREASING CLOUDS AND WINDS FRIDAY NIGHT
OVER THE FRESH SNOWPACK WILL ALLOW FOR GOOD RADIATIONAL
COOLING...AND DID CONTINUE TO UNDERCUT GUIDANCE SLIGHTLY...WITH
FORECAST MINS IN THE SINGLE DIGITS TO LOW TEENS ACROSS THE AREA.
MODELS START TO SHOW A STRONGER SURGE OF WARMER AIR ARRIVING BETWEEN
925-850MB SATURDAY NIGHT...HOWEVER SNOWPACK AND STRONG SUBSIDENCE
INVERSION SHOULD KEEP SURFACE TEMPERATURES COOL AS THE BOUNDARY
LAYERS REMAINS DECOUPLED. ONCE AGAIN...CONTINUED TO UNDERCUT MOS
GUIDANCE VALUES WITH MINS ONLY SLIGHTLY WARMER THAN FRIDAY NIGHT.
ENERGY NOW OFF THE PACIFIC NORTHWEST COAST WILL MAKE ITS WAY INTO
THE CENTRAL PLAINS ON SUNDAY AND THEN ACROSS THE GREAT LAKES MONDAY.
STRONG UPPER DIFFLUENCE AND UPPER HEIGHTS FALLS LEE OF THE ROCKIES
WILL SPIN UP A FAIRLY STRONG LOW PRESSURE SYSTEM. LATEST CONSENSUS
FROM MEDIUM-RANGE MODELS TRACKS THE SURFACE LOW ACROSS NORTHERN
MICHIGAN MONDAY. 50 KT LOW LEVEL JET PRECEDING THE SYSTEM WILL FEED
WARMTH AND MOISTURE (PW AROUND 0.8 INCHES) UP INTO LOWER MICHIGAN
STARTING SUNDAY AFTERNOON. IT APPEARS MOST PRECIPITATION WILL HOLD
OFF UNTIL VERY LATE IN THE DAY AND OVERNIGHT WHEN STRONGER
ISENTROPIC ASCENT AND UPPER DIVERGENCE WILL OVERSPREAD THE AREA.
STRONGER FORCING SHOULD ALSO COINCIDE WITH WARMING SURFACE
TEMPERATURES PER LATEST TRENDS IN THE EURO AND GFS...AND EXPECT
MOSTLY RAIN TO FALL OUT OF THIS SYSTEM. COLD FRONT WILL PUSH THROUGH
THE AREA EARLY MONDAY...CHANGING PRECIPITATION TO SNOW. STRONG DRY
SLOT PRECEDING THE FRONT IN ADDITION TO DRIER AIR ALOFT STRIPPING
AWAY ICE NUCLEI BEHIND THE FRONT WILL KEEP POTENTIAL FOR SNOW
ACCUMULATIONS LOW.
NORTHWEST FLOW AND PATTERN OF VERY WEAK CLIPPER SYSTEMS THEN LOOKS
TO BECOME ESTABLISHED TUESDAY THROUGH THURSDAY. LATEST EURO AND GFS
HINT AT A STRONGER SYSTEM WORKING ACROSS THE GREAT LAKES LATE ON
THURSDAY...BUT MODEL TO MODEL AND RUN TO RUN CONSISTENCY HAS BEEN
POOR AND WILL LEAVE MENTION OUT OF FORECAST FOR NOW. EARLIER SYSTEM
THE GFS HAD ADVERTISED CLIPPING THE SOUTHERN PORTION OF MICHIGAN
MID-WEEK NOW LOOKS TO TRACK FURTHER SOUTH AS UPPER LEVEL ENERGY
DIVES FURTHER INTO THE U.S. FROM CANADA.
MARINE...
A LOW PRESSURE SYSTEM WILL STRENGTHEN AS IT TRACKS ACROSS THE
SOUTHERN GREAT LAKES THIS EVENING AND TONIGHT. THIS SYSTEM WILL
CONTINUE EASTWARD EVENTUALLY BEING ABSORBED BY A STRONGER NOREASTER
ALONG THE ATLANTIC COAST FRIDAY NIGHT. THE GRADIENT WILL TIGHTEN
OVERNIGHT AS EASTERLY WINDS INCREASE AND BACK TO THE NORTHEAST.
WINDS WILL INCREASE TO AROUND 25 KNOTS SUSTAINED OVERNIGHT
NECESSITATING BRISK WIND ADVISORIES FOR ALL NEARSHORE ZONES. THE
EXCEPTION WILL BE SAGINAW BAY WHERE A GALE WARNING HAS BEEN ISSUED
AS WINDS FUNNEL DOWN THE BAY WITH THE FAVORABLE NORTHEAST FETCH.
SOME FREEZING SPRAY WILL BE POSSIBLE ACROSS NORTHERN LAKE HURON WITH
THE COOLER TEMPERATURES AND SLIGHTLY STRONGER FLOW TONIGHT...BUT
INTENSITY AND DURATION SHOULD STAY BELOW WARNING CRITERIA. AFTER
HIGH PRESSURE RETURNS TO THE REGION FOR MUCH OF THE WEEKEND...THE
NEXT LOW PRESSURE SYSTEM WILL TARGET THE REGION SUNDAY NIGHT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING...MIZ047-MIZ048-MIZ053...UNTIL 10 AM FRIDAY.
WINTER STORM WARNING...MIZ049-MIZ054-MIZ055-MIZ063...UNTIL NOON
FRIDAY.
WINTER WEATHER ADVISORY...MIZ060-MIZ061-MIZ062-MIZ068-MIZ069-MIZ070-
MIZ075-MIZ076-MIZ082-MIZ083...UNTIL NOON FRIDAY.
LAKE HURON...
GALE WARNING...SAGINAW BAY...UNTIL 1 PM FRIDAY.
BRISK WIND ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
HURON...UNTIL 10 PM FRIDAY.
WINTER STORM WARNING...NEARSHORE WATERS FROM PORT AUSTIN TO HARBOR
BEACH...UNTIL NOON FRIDAY.
LAKE ST CLAIR...
BRISK WIND ADVISORY...FROM 10 AM FRIDAY TO 10 PM FRIDAY.
MI WATERS OF LAKE ERIE...
BRISK WIND ADVISORY...FROM 10 AM FRIDAY TO 10 PM FRIDAY.
&&
$$
AVIATION.....DG
UPDATE.......DG
SHORT TERM...MANN
LONG TERM....HLO
MARINE.......DRK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
749 PM CST SAT FEB 9 2013
.UPDATE...
ADDED AREAS OF FREEZING DRIZZLE FOR EARLY TONIGHT ACROSS CENTRAL
MN AND PARTS OF WEST CENTRAL WI ALONG HIGHWAY 8. RETURNS
INCREASING ON RADAR IN LONG PULSE TO THE NORTH OF THE METRO. A FEW
REPORTS OF LIGHT ICING HAVE BEEN RECEIVED BY THIS OFFICE AND KDLH.
THE FREEZING DRIZZLE IS AT THE NOSE OF STRONG LOW LEVEL WAA AND
FRONTOGENESIS. TO THE WEST... PRECIPITATION IS STREAMING RAPIDLY
NORTHWARD ACROSS EASTERN SD. SOME THUNDER BEING REPORTED WEST OF
OUR CWA NEAR WATERTOWN SD. HENCE...ADDED ISOLATED THUNDER FOR A
FEW OF OUR FAR WESTERN COUNTIES THROUGH THE EVENING. ONE
OBSERVATION THIS EVENING IS THAT THE PRECIPITATION TO OUR WEST AND
SOUTHWEST IS DEVELOPING NORTHEAST MUCH FASTER THAN FORECAST. THE
HRRR IS DOING A PRETTY GOOD JOB AND HAS SOME SERIOUS CONVECTION
ALONG THE MN/IA BORDER SUNDAY MORNING WITH THE PTYPE MAINLY SLEET
AND SNOW.
&&
.DISCUSSION... /ISSUED 229 PM CST SAT FEB 9 2013/
MAIN CONCERN CONTINUES TO BE THE SIGNIFICANT WINTER STORM EXPECTED
TO IMPACT THE AREA FROM LATE TONIGHT INTO MONDAY. THE LATEST WATER
VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS SHOW THE FEATURE OF
INTEREST MAKING ITS WAY THROUGH THE SOUTHERN ROCKIES AT THE
CURRENT TIME... WITH A NICE RIDGE DEVELOPING AHEAD OF IT ACROSS
THE NORTHERN PLAINS. THE SHORTENING WAVELENGTH BETWEEN THESE
FEATURES WILL BE COINCIDENT WITH THE SYSTEM DEEPENING AND MOVING
NORTHEAST TOWARD OUR AREA... AND WILL MANIFEST ITSELF IN A PERIOD
OF STRONG FORCING LATE TONIGHT THROUGH THE DAY ON SUNDAY. THERE
CONTINUES TO BE SOME UNCERTAINTY IN PRECIPITATION TYPE WITH THIS
SYSTEM... ALTHOUGH THE 12Z GUIDANCE HAS COME INTO GOOD AGREEMENT
ON TRACKING THE SURFACE LOW ACROSS IOWA AND FAR SOUTHEAST
MINNESOTA AND INTO CENTRAL WISCONSIN SUNDAY INTO SUNDAY EVENING.
THE REMAINING DIFFERENCES REVOLVE AROUND HOW THE THERMAL PROFILE
WILL EVOLVE THROUGH THE EVENING... PARTICULARLY FROM THE SURFACE
TO 925MB. THE GFS CONTINUES TO BE WARMEST IN THAT LAYER... WITH
THE ECMWF... NAM... AND GEM SUGGESTING THINGS WILL BE COOLER AND
MOSTLY SNOW ACROSS MOST OF THE AREA. GENERALLY FOLLOWED A BLEND OF
THE ECMWF AND NAM FOR THE FORECAST DETAILS... WITH SOME ADDITIONAL
RELIANCE ON THE HIGH RESOLUTION WINDOW RUNS AND LOCAL 4KM GUIDANCE.
EXPECT PCPN TO OVERSPREAD THE CWFA OVERNIGHT INTO SUNDAY
MORNING... WITH SOME FREEZING RAIN POSSIBLE INITIALLY ACROSS
SOUTHERN AND EASTERN MINNESOTA BEFORE THE ELEVATED WARM LAYER
SATURATES AND COOLS TO BELOW FREEZING WET BULB VALUES. AFTER THAT
POINT... IT LOOKS LIKE THE MAIN CHANCES FOR MIXED PCPN WILL BE
FROM NEAR THE TWIN CITIES SOUTH AND EAST... WHERE THE ELEVATED
WARM LAYER WILL FLIRT WITH 0C AT TIMES AND NEAR SURFACE
TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE FREEZING. THE
WESTERN AND NORTHERN PORTIONS OF THE AREA LOOK TO BE SNOW FOR THE
ENTIRE EVENT... AND WITH THE MAIN MID-LEVEL DEFORMATION ZONE AND
ASSOCIATED FRONTOGENESIS IMPACTED THOSE AREAS... STILL EXPECT THE
BEST SNOW AMOUNTS TO OCCUR OVER THE FAR WEST AND NORTHWEST PART OF
THE AREA. PCPN ACROSS THE CENTRAL AND EASTERN CWFA... INCLUDING
THE TWIN CITIES... WILL BE PRIMARILY FORCED BY THE SURGE OF STRONG
WARM ADVECTION/ISENTROPIC LIFT SUNDAY MORNING... ALONG WITH A
DECENT AREA OF UPPER DIVERGENCE IN THE LEFT EXIT REGION OF THE
APPROACHING JET. THALER QG DIAGNOSTICS ARE VERY CONSISTENT BETWEEN
THE VARIOUS GUIDANCE SOURCES... AND ALL PUSH A STRONG SLUG OF QG-
OMEGA ACROSS THE CWFA DURING THE MORNING AND EARLY AFTERNOON
HOURS. THE MID-LEVEL DRY SLOT ASSOCIATED WITH THE UPPER JET STILL
LOOKS LIKE IT SHOULD IMPACT AT LEAST THE SOUTHEAST THIRD OR SO OF
THE CWFA... LIKELY FROM AROUND THE TWIN CITIES METRO SOUTH/EAST...
DURING THE AFTERNOON HOURS. THAT COULD BRING A PERIOD OF SOME
DRIZZLE OR FREEZING DRIZZLE... BUT AT THIS POINT DIDN/T TRY TO
WORK THAT INTO THE FORECAST GIVEN THE MORE SIGNIFICANT PCPN WHICH
WILL OCCUR PRIOR TO THAT AND SOME SNOW WITH THE UPPER LOW
AFTERWARD. AS THE DRY SLOT PUNCHES IN TOWARD THE AREA WE WILL SEE
CONVECTIVELY INSTABILITY INCREASE DRAMATICALLY JUST AHEAD OF IT AS
THE DRY AIR MOVES IN ABOVE THE MOIST BOUNDARY LAYER AND LOWER
TROPOSPHERE. SHOWALTER INDICES ACTUALLY DIP TO AROUND OR A BIT
BELOW ZERO OVER THE SOUTHEAST PORTION OF THE CWFA DURING THE
AFTERNOON... SO WOULDN/T BE SURPRISED IF SOME THUNDER OCCURRED.
ALSO LEFT THAT OUT OF THE FORECAST FOR NOW... BUT IT IS CERTAINLY
WORTH KEEPING AN EYE ON... SINCE ANY BURST OF CONVECTION WOULD
LIKELY CHANGE ANY LINGERING MIXED PCPN OVER TO SNOW AND COULD
AUGMENT PCPN TOTALS ACROSS THE SOUTHERN AND EASTERN PORTIONS OF
THE WINTER STORM WARNING AREA.
EXPECT TO SEE SOME SNOW PERSIST INTO SUNDAY NIGHT ON THE BACKSIDE
OF THE LOW... WITH SNOW SHOWERS LINGERING INTO MONDAY WITH THE
CYCLONIC FLOW. THE PRESSURE GRADIENT WILL TIGHTEN LATE SUNDAY
NIGHT INTO MONDAY... WITH 925MB WINDS INCREASING TO 30-40 KT
ACROSS MUCH OF THE WESTERN AND SOUTHWESTERN CWFA. KEPT THE
BLIZZARD WATCH GOING TO ACCOUNT FOR THE POSSIBILITY OF BLIZZARD
CONDITIONS FROM THE SNOW SHOWERS AND BLOWING SNOW LATE SUNDAY
NIGHT INTO MONDAY. DIDN/T WANT TO BLANKET THE ENTIRE TIME FRAME
WITH A BLIZZARD WARNING... SINCE MOST OF THE SNOW WILL OCCUR
SUNDAY PRIOR TO WHEN WINDS ARE EXPECTED TO INCREASE. SO... IT
SEEMED THE MOST LOGICAL WAY TO DO THINGS FOR NOW WAS TO GO WITH
THE WINTER STORM WARNING WHILE KEEPING A BLIZZARD WATCH FOR THE
LATER TIME FRAME.
RIDGING SHOULD BRING QUIET WEATHER FOR THE MIDDLE PART OF THE
WEEK... WITH AN ALBERTA CLIPPER DROPPING INTO THE REGION FOR THE
THURSDAY-FRIDAY TIME FRAME. INCLUDED A CHANCE OF SOME SNOW FROM
THURSDAY INTO FRIDAY AS THIS SYSTEM MOVES ACROSS THE REGION. THERE
REMAIN SOME DIFFERENCES BETWEEN THE ECMWF AND GFS... SO DON/T SEE
MUCH REASON TO GO WITH ANYTHING MORE THAN CHANCE POPS AT THIS
POINT. TEMPERATURES THROUGH THE WEEK LOOK SEASONABLE... EXCEPT
BEHIND THE CLIPPER FRIDAY INTO SATURDAY WHEN BELOW NORMAL
TEMPERATURES ARE EXPECTED TO RETURN TO THE AREA.
&&
.AVIATION... /00Z TAF ISSUANCE/
MAIN FORECAST CONCERN IS TIMING OF THE INITIAL BAND OF -SN...WITH
A MIXTURE OF PL/FZRA...THEN WHETHER AN INTENSE BAND OF +SN
DEVELOPS ACROSS S MN DURING THE MORNING HRS.
AXN/STC SHOULD BE IN THE COLDER AIR TO CONTINUE ALL -SN FOR PTYPE
FOR THE DURATION OF THE TAF PERIOD...WITH ONLY A SLIGHT CHC EARLY
FOR STC TO SEE PL. INITIALLY PRECIPITATION WILL LIKELY BE
LIGHT...WITH THE HEAVIEST DEVELOPING BY 9-12Z...WITH THE MOST
INTENSE AFT 12Z FOR RWF/STC/RNH/MSP. HOWEVER...THERE REMAINS SOME
CONCERN IF A HEAVIER BAND OF SNOW DEVELOPS SUNDAY MORNING AS A
LARGE AREA OF CONVECTION DEVELOPS ACROSS IOWA...BASICALLY
HINDERING MOISTURE ADVECTION TO THE NORTH ACROSS S MN. IN
ADDITION...MODELS ARE TRYING TO CHG THE -SNPL BACK TO RA IN THE
AFTN FOR RWF/MSP/RNH AS THE BOUNDARY OF VERY WARM AIR TO THE SOUTH
COLLIDES TO THE ARCTIC BOUNDARY TO THE N/NW.
THEREFORE...CONFIDENCE REMAINS VERY LOW FOR PTYPE AFT 12Z FOR ALL
BUT AXN/STC. EVENTUALLY SUNDAY AFTN SHOULD SEE SOME IMPROVEMENT AS
THE MAIN LOW SHIFTS OFF TO THE E/NE. HOWEVER...LINGERING LIGHT
SNOW WILL HOLD ON...ESPECIALLY ACROSS CENTRAL/EC MN. WINDS WILL
HOLD ON FROM THE SE/E OVERNIGHT AND BEGIN TO GUST BY MORNING. THE
WINDS WILL SHIFT TO THE E/NE DURING THE MORNING...WITH A MORE NE/N
DIRECTION BY LATE IN THE DAY.
KMSP...
TIMING OF PRECIPITATION REMAINS ON TRACK AFT 9Z TONIGHT...WITH
THE BULK OF THE PRECIPITATION AFT 12Z...AND POSSIBLY A PERIOD OF
HEAVY PRECIPITATION BETWEEN 16-20Z ON SUNDAY. PRECIPITATION TYPE
REMAINS THE MAIN QUESTION AND LOW CONFIDENCE CONTINUES...ESPECIALLY
DURING THE DAY SUNDAY. MODELS HAVE TRENDED TOWARD A COLDER
SOLUTION...SO PRECIPITATION TYPE IS BECOMING MORE OF SNOW/PL THAN
FZRA. BUT...CONFIDENCE REMAINS LOW...ESPECIALLY AFT 15Z IF COLDER
AIR OVERTAKES THE WARMER AIR TO THE SOUTH. IN ADDITION...WILL A
LARGE AREA OF CONVECTION ACROSS IOWA EXPECTED...LEAD TO LESS
MOISTURE ADVECTION ACROSS SOUTHERN MN ON SUNDAY. HAVE TRENDED
TOWARD A MORE SNOWFALL SCENARIO AFT 16Z...WITH A PERIOD OF
MODERATE/HEAVY SNOWFALL BETWEEN 16-20Z. LATER SHIFTS CAN PINPOINT
IF THIS DEVELOPS AND TIMING. SUNDAY AFTERNOON WILL LIKELY SEE A
LULL IN THE PRECIPITATION...WITH MORE SNOW POSSIBLE LATE
SUNDAY/EARLY MONDAY. WINDS WILL BE PREDOMINATELY E/SE THRU
15Z...THEN A SHIFT TO THE E/NE AFT 15Z...AND MORE N/NE BY LATE IN
THE DAY/EVENING HRS.
/OUTLOOK FOR KMSP/
SUN NGT...IFR/LIFR WITH SN. NE WIND 10 KTS BCMG NW 15 KTS.
MON...IFR WITH -SN EARLY...THEN MVFR WITH -SN/BLSN. NW WINDS 17G25KTS.
TUE...VFR. WINDS W AT 5-10 KTS. ..JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST MONDAY
FOR BLUE EARTH-LE SUEUR-RICE-SCOTT-WASECA-WATONWAN.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO MIDNIGHT CST
SUNDAY NIGHT FOR BROWN-CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI
PARLE-NICOLLET-POPE-REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-
YELLOW MEDICINE.
BLIZZARD WATCH FROM LATE SUNDAY NIGHT THROUGH MONDAY AFTERNOON
FOR BROWN-CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-NICOLLET-
POPE-REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-YELLOW MEDICINE.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 PM CST MONDAY
FOR CARVER-MCLEOD-MEEKER-STEARNS-TODD-WRIGHT.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 AM CST MONDAY
FOR ANOKA-BENTON-CHISAGO-HENNEPIN-ISANTI-KANABEC-MILLE LACS-
MORRISON-RAMSEY-SHERBURNE-WASHINGTON.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 3 PM CST SUNDAY
FOR FARIBAULT-FREEBORN-MARTIN-STEELE.
WINTER WEATHER ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY
NIGHT FOR GOODHUE.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT CST
SUNDAY NIGHT FOR DAKOTA.
WI...WINTER WEATHER ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY
NIGHT FOR CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE.
WINTER STORM WARNING FROM 6 AM SUNDAY TO 6 AM CST MONDAY FOR
BARRON-POLK-RUSK-ST. CROIX.
&&
$$
RAH/TRH/JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
541 PM CST SAT FEB 9 2013
.DISCUSSION...
MAIN CONCERN CONTINUES TO BE THE SIGNIFICANT WINTER STORM EXPECTED
TO IMPACT THE AREA FROM LATE TONIGHT INTO MONDAY. THE LATEST WATER
VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS SHOW THE FEATURE OF
INTEREST MAKING ITS WAY THROUGH THE SOUTHERN ROCKIES AT THE
CURRENT TIME... WITH A NICE RIDGE DEVELOPING AHEAD OF IT ACROSS
THE NORTHERN PLAINS. THE SHORTENING WAVELENGTH BETWEEN THESE
FEATURES WILL BE COINCIDENT WITH THE SYSTEM DEEPENING AND MOVING
NORTHEAST TOWARD OUR AREA... AND WILL MANIFEST ITSELF IN A PERIOD
OF STRONG FORCING LATE TONIGHT THROUGH THE DAY ON SUNDAY. THERE
CONTINUES TO BE SOME UNCERTAINTY IN PRECIPITATION TYPE WITH THIS
SYSTEM... ALTHOUGH THE 12Z GUIDANCE HAS COME INTO GOOD AGREEMENT
ON TRACKING THE SURFACE LOW ACROSS IOWA AND FAR SOUTHEAST
MINNESOTA AND INTO CENTRAL WISCONSIN SUNDAY INTO SUNDAY EVENING.
THE REMAINING DIFFERENCES REVOLVE AROUND HOW THE THERMAL PROFILE
WILL EVOLVE THROUGH THE EVENING... PARTICULARLY FROM THE SURFACE
TO 925MB. THE GFS CONTINUES TO BE WARMEST IN THAT LAYER... WITH
THE ECMWF... NAM... AND GEM SUGGESTING THINGS WILL BE COOLER AND
MOSTLY SNOW ACROSS MOST OF THE AREA. GENERALLY FOLLOWED A BLEND OF
THE ECMWF AND NAM FOR THE FORECAST DETAILS... WITH SOME ADDITIONAL
RELIANCE ON THE HIGH RESOLUTION WINDOW RUNS AND LOCAL 4KM GUIDANCE.
EXPECT PCPN TO OVERSPREAD THE CWFA OVERNIGHT INTO SUNDAY
MORNING... WITH SOME FREEZING RAIN POSSIBLE INITIALLY ACROSS
SOUTHERN AND EASTERN MINNESOTA BEFORE THE ELEVATED WARM LAYER
SATURATES AND COOLS TO BELOW FREEZING WET BULB VALUES. AFTER THAT
POINT... IT LOOKS LIKE THE MAIN CHANCES FOR MIXED PCPN WILL BE
FROM NEAR THE TWIN CITIES SOUTH AND EAST... WHERE THE ELEVATED
WARM LAYER WILL FLIRT WITH 0C AT TIMES AND NEAR SURFACE
TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE FREEZING. THE
WESTERN AND NORTHERN PORTIONS OF THE AREA LOOK TO BE SNOW FOR THE
ENTIRE EVENT... AND WITH THE MAIN MID-LEVEL DEFORMATION ZONE AND
ASSOCIATED FRONTOGENESIS IMPACTED THOSE AREAS... STILL EXPECT THE
BEST SNOW AMOUNTS TO OCCUR OVER THE FAR WEST AND NORTHWEST PART OF
THE AREA. PCPN ACROSS THE CENTRAL AND EASTERN CWFA... INCLUDING
THE TWIN CITIES... WILL BE PRIMARILY FORCED BY THE SURGE OF STRONG
WARM ADVECTION/ISENTROPIC LIFT SUNDAY MORNING... ALONG WITH A
DECENT AREA OF UPPER DIVERGENCE IN THE LEFT EXIT REGION OF THE
APPROACHING JET. THALER QG DIAGNOSTICS ARE VERY CONSISTENT BETWEEN
THE VARIOUS GUIDANCE SOURCES... AND ALL PUSH A STRONG SLUG OF QG-
OMEGA ACROSS THE CWFA DURING THE MORNING AND EARLY AFTERNOON
HOURS. THE MID-LEVEL DRY SLOT ASSOCIATED WITH THE UPPER JET STILL
LOOKS LIKE IT SHOULD IMPACT AT LEAST THE SOUTHEAST THIRD OR SO OF
THE CWFA... LIKELY FROM AROUND THE TWIN CITIES METRO SOUTH/EAST...
DURING THE AFTERNOON HOURS. THAT COULD BRING A PERIOD OF SOME
DRIZZLE OR FREEZING DRIZZLE... BUT AT THIS POINT DIDN/T TRY TO
WORK THAT INTO THE FORECAST GIVEN THE MORE SIGNIFICANT PCPN WHICH
WILL OCCUR PRIOR TO THAT AND SOME SNOW WITH THE UPPER LOW
AFTERWARD. AS THE DRY SLOT PUNCHES IN TOWARD THE AREA WE WILL SEE
CONVECTIVELY INSTABILITY INCREASE DRAMATICALLY JUST AHEAD OF IT AS
THE DRY AIR MOVES IN ABOVE THE MOIST BOUNDARY LAYER AND LOWER
TROPOSPHERE. SHOWALTER INDICES ACTUALLY DIP TO AROUND OR A BIT
BELOW ZERO OVER THE SOUTHEAST PORTION OF THE CWFA DURING THE
AFTERNOON... SO WOULDN/T BE SURPRISED IF SOME THUNDER OCCURRED.
ALSO LEFT THAT OUT OF THE FORECAST FOR NOW... BUT IT IS CERTAINLY
WORTH KEEPING AN EYE ON... SINCE ANY BURST OF CONVECTION WOULD
LIKELY CHANGE ANY LINGERING MIXED PCPN OVER TO SNOW AND COULD
AUGMENT PCPN TOTALS ACROSS THE SOUTHERN AND EASTERN PORTIONS OF
THE WINTER STORM WARNING AREA.
EXPECT TO SEE SOME SNOW PERSIST INTO SUNDAY NIGHT ON THE BACKSIDE
OF THE LOW... WITH SNOW SHOWERS LINGERING INTO MONDAY WITH THE
CYCLONIC FLOW. THE PRESSURE GRADIENT WILL TIGHTEN LATE SUNDAY
NIGHT INTO MONDAY... WITH 925MB WINDS INCREASING TO 30-40 KT
ACROSS MUCH OF THE WESTERN AND SOUTHWESTERN CWFA. KEPT THE
BLIZZARD WATCH GOING TO ACCOUNT FOR THE POSSIBILITY OF BLIZZARD
CONDITIONS FROM THE SNOW SHOWERS AND BLOWING SNOW LATE SUNDAY
NIGHT INTO MONDAY. DIDN/T WANT TO BLANKET THE ENTIRE TIME FRAME
WITH A BLIZZARD WARNING... SINCE MOST OF THE SNOW WILL OCCUR
SUNDAY PRIOR TO WHEN WINDS ARE EXPECTED TO INCREASE. SO... IT
SEEMED THE MOST LOGICAL WAY TO DO THINGS FOR NOW WAS TO GO WITH
THE WINTER STORM WARNING WHILE KEEPING A BLIZZARD WATCH FOR THE
LATER TIME FRAME.
RIDGING SHOULD BRING QUIET WEATHER FOR THE MIDDLE PART OF THE
WEEK... WITH AN ALBERTA CLIPPER DROPPING INTO THE REGION FOR THE
THURSDAY-FRIDAY TIME FRAME. INCLUDED A CHANCE OF SOME SNOW FROM
THURSDAY INTO FRIDAY AS THIS SYSTEM MOVES ACROSS THE REGION. THERE
REMAIN SOME DIFFERENCES BETWEEN THE ECMWF AND GFS... SO DON/T SEE
MUCH REASON TO GO WITH ANYTHING MORE THAN CHANCE POPS AT THIS
POINT. TEMPERATURES THROUGH THE WEEK LOOK SEASONABLE... EXCEPT
BEHIND THE CLIPPER FRIDAY INTO SATURDAY WHEN BELOW NORMAL
TEMPERATURES ARE EXPECTED TO RETURN TO THE AREA.
&&
.AVIATION.../00Z TAF ISSUANCE/
MAIN FORECAST CONCERN IS TIMING OF THE INITIAL BAND OF -SN...WITH
A MIXTURE OF PL/FZRA...THEN WHETHER AN INTENSE BAND OF +SN
DEVELOPS ACROSS S MN DURING THE MORNING HRS.
AXN/STC SHOULD BE IN THE COLDER AIR TO CONTINUE ALL -SN FOR PTYPE
FOR THE DURATION OF THE TAF PERIOD...WITH ONLY A SLIGHT CHC EARLY
FOR STC TO SEE PL. INITIALLY PRECIPITATION WILL LIKELY BE
LIGHT...WITH THE HEAVIEST DEVELOPING BY 9-12Z...WITH THE MOST
INTENSE AFT 12Z FOR RWF/STC/RNH/MSP. HOWEVER...THERE REMAINS SOME
CONCERN IF A HEAVIER BAND OF SNOW DEVELOPS SUNDAY MORNING AS A
LARGE AREA OF CONVECTION DEVELOPS ACROSS IOWA...BASICALLY
HINDERING MOISTURE ADVECTION TO THE NORTH ACROSS S MN. IN
ADDITION...MODELS ARE TRYING TO CHG THE -SNPL BACK TO RA IN THE
AFTN FOR RWF/MSP/RNH AS THE BOUNDARY OF VERY WARM AIR TO THE SOUTH
COLLIDES TO THE ARCTIC BOUNDARY TO THE N/NW.
THEREFORE...CONFIDENCE REMAINS VERY LOW FOR PTYPE AFT 12Z FOR ALL
BUT AXN/STC. EVENTUALLY SUNDAY AFTN SHOULD SEE SOME IMPROVEMENT AS
THE MAIN LOW SHIFTS OFF TO THE E/NE. HOWEVER...LINGERING LIGHT
SNOW WILL HOLD ON...ESPECIALLY ACROSS CENTRAL/EC MN. WINDS WILL
HOLD ON FROM THE SE/E OVERNIGHT AND BEGIN TO GUST BY MORNING. THE
WINDS WILL SHIFT TO THE E/NE DURING THE MORNING...WITH A MORE NE/N
DIRECTION BY LATE IN THE DAY.
KMSP...
TIMING OF PRECIPITATION REMAINS ON TRACK AFT 9Z TONIGHT...WITH
THE BULK OF THE PRECIPITATION AFT 12Z...AND POSSIBLY A PERIOD OF
HEAVY PRECIPITATION BETWEEN 16-20Z ON SUNDAY. PRECIPITATION TYPE
REMAINS THE MAIN QUESTION AND LOW CONFIDENCE CONTINUES...ESPECIALLY
DURING THE DAY SUNDAY. MODELS HAVE TRENDED TOWARD A COLDER
SOLUTION...SO PRECIPITATION TYPE IS BECOMING MORE OF SNOW/PL THAN
FZRA. BUT...CONFIDENCE REMAINS LOW...ESPECIALLY AFT 15Z IF COLDER
AIR OVERTAKES THE WARMER AIR TO THE SOUTH. IN ADDITION...WILL A
LARGE AREA OF CONVECTION ACROSS IOWA EXPECTED...LEAD TO LESS
MOISTURE ADVECTION ACROSS SOUTHERN MN ON SUNDAY. HAVE TRENDED
TOWARD A MORE SNOWFALL SCENARIO AFT 16Z...WITH A PERIOD OF
MODERATE/HEAVY SNOWFALL BETWEEN 16-20Z. LATER SHIFTS CAN PINPOINT
IF THIS DEVELOPS AND TIMING. SUNDAY AFTERNOON WILL LIKELY SEE A
LULL IN THE PRECIPITATION...WITH MORE SNOW POSSIBLE LATE
SUNDAY/EARLY MONDAY. WINDS WILL BE PREDOMINATELY E/SE THRU
15Z...THEN A SHIFT TO THE E/NE AFT 15Z...AND MORE N/NE BY LATE IN
THE DAY/EVENING HRS.
/OUTLOOK FOR KMSP/
SUN NGT...IFR/LIFR WITH SN. NE WIND 10 KTS BCMG NW 15 KTS.
MON...IFR WITH -SN EARLY...THEN MVFR WITH -SN/BLSN. NW WINDS 17G25KTS.
TUE...VFR. WINDS W AT 5-10 KTS. ..JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST MONDAY
FOR BLUE EARTH-LE SUEUR-RICE-SCOTT-WASECA-WATONWAN.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO MIDNIGHT CST
SUNDAY NIGHT FOR BROWN-CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI
PARLE-NICOLLET-POPE-REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-
YELLOW MEDICINE.
BLIZZARD WATCH FROM LATE SUNDAY NIGHT THROUGH MONDAY AFTERNOON
FOR BROWN-CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-NICOLLET-
POPE-REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-YELLOW MEDICINE.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 PM CST MONDAY
FOR CARVER-MCLEOD-MEEKER-STEARNS-TODD-WRIGHT.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 AM CST MONDAY
FOR ANOKA-BENTON-CHISAGO-HENNEPIN-ISANTI-KANABEC-MILLE LACS-
MORRISON-RAMSEY-SHERBURNE-WASHINGTON.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 3 PM CST SUNDAY
FOR FARIBAULT-FREEBORN-MARTIN-STEELE.
WINTER WEATHER ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY
NIGHT FOR GOODHUE.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT CST
SUNDAY NIGHT FOR DAKOTA.
WI...WINTER WEATHER ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY
NIGHT FOR CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE.
WINTER STORM WARNING FROM 6 AM SUNDAY TO 6 AM CST MONDAY FOR
BARRON-POLK-RUSK-ST. CROIX.
&&
$$
TRH/JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1055 PM CST THU FEB 7 2013
.UPDATE...FOR 06Z AVIATION DISCUSSION BELOW
&&
.DISCUSSION.../ISSUED 232 PM CST THU FEB 7 2013/
THE MAIN FORECAST ISSUE IS OBVIOUSLY THE POTENTIAL FOR A
SIGNIFICANT WINTER STORM ACROSS THE AREA OVER THE SECOND HALF OF
THE WEEKEND. LATEST WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSES
SHOW THE FEATURE OF INTEREST MOVING INTO THE WEST COAST AT THE
CURRENT TIME. THE OTHER FEATURES OF INTEREST IN THE BIG PICTURE
ARE THE UPPER WAVE CURRENTLY MOVING THROUGH OUR AREA... WHICH IS
HELPING TO GENERATE A SWATH OF PCPN OFF TO OUR SOUTHEAST... AND
THE SOUTHERN STREAM WAVE MOVING ALONG THE GULF COAST. THESE TWO
UPPER WAVES WILL PHASE OFF THE MID-ATLANTIC COAST AND CREATE A
BLOCKBUSTER OF A WINTER STORM FOR FOLKS IN NEW ENGLAND OVER THE
NEXT 48 HOURS. THE EVOLUTION OF THAT SYSTEM WILL IMPACT HOW THE
WESTERN SHORTWAVE BEHAVES AS IT EJECTS NORTHEAST INTO OUR AREA
OVER THE LATTER HALF OF THE WEEKEND. THE DEGREE TO WHICH THE
EASTERN STORM BOTTLES UP THE FLOW WILL HELP DICTATE THE TRACK AND
AMPLITUDE OF THE UPPER PATTERN AHEAD OF OUR SYSTEM... WHICH IS
LIKELY PART OF WHY WE/RE STILL SEEING A SIGNIFICANT AMOUNT OF
SPREAD IN THE GUIDANCE AS TO HOW THINGS WILL UNFOLD ACROSS OUR
AREA. THE NAM AND GFS ARE FARTHEST WEST... ALONG WITH THE SREF...
WHILE THE ECMWF... GEM... AND FIM ARE FARTHER EAST. AT THIS
POINT... THE CONSENSUS OF THE GUIDANCE IS FAIRLY CLOSE TO THE
ECMWF EVOLUTION... SO WILL STICK SOMEWHAT CLOSE TO THAT WHILE
ALLOWING FOR A BIT MORE WARMING IN THE LOW LEVEL THERMAL PROFILES
IN ACCORDANCE WITH WHAT THE NAM AND GFS SUGGEST TO SOME EXTENT.
THIS WOULD CONTINUE TO SUGGEST A MIXED PCPN EVENT FOR A GOOD PART
OF THE AREA... WITH THE NORTH AND NORTHWEST PORTION OF THE AREA
HAVING THE GREATEST LIKELIHOOD OF REMAINING ALL SNOW. WITH THAT IN
MIND... WILL BE ISSUING A WINTER STORM WATCH THAT INCLUDES THE
NORTHERN AND WESTERN PORTION OF THE AREA FROM SATURDAY NIGHT
THROUGH SUNDAY NIGHT. IT IS POSSIBLE THAT THE WATCH MAY NEED TO BE
EXTENDED SOUTH/EAST IN AREA DEPENDING UPON HOW EXPECTATIONS
EVOLVE... BUT FOR NOW DECIDED TO FOCUS ON WHERE CONFIDENCE IS
HIGHEST THAT 6-8 INCHES OR MORE OF SNOW WILL OCCUR... ALONG WITH
STRONG WINDS.
IN THE SHORTER TERM... LINGERING VERY LIGHT FREEZING DRIZZLE
CURRENTLY ACROSS THE AREA SHOULD MIX WITH SOME SNOWFLAKES AS WE
SEE A BIT OF SEEDING FROM DEEPER MOISTURE ASSOCIATED WITH THE
UPPER WAVE MOVING ACROSS THE AREA... AND ALL OF THIS ACTIVITY
SHOULD EXIT QUICKLY TO THE EAST THIS EVENING AS WE GET ONTO THE
BACKSIDE OF THE WAVE AND SEE SOME SUBSIDENCE SPREAD OVER THE AREA.
HIGH PRESSURE WILL REIGN FRIDAY THROUGH FRIDAY NIGHT... ALLOWING
FOR FAIR AND DRY CONDITIONS. RETURN FLOW WILL SETUP BY SATURDAY
MORNING... THEN REMAIN IN PLACE INTO SATURDAY NIGHT... ALLOWING
FOR GOOD MOISTURE RETURN AHEAD OF THE SYSTEM WHICH WILL EXIT THE
ROCKIES SATURDAY EVENING AND MOVE NORTHEAST INTO NEBRASKA BY
SUNDAY MORNING. GOOD ISENTROPIC ASCENT IS PROGGED ALONG THE
EASTERN PERIPHERY OF THE INVERTED TROUGH AHEAD OF THE SURFACE
LOW... AND UPPER DIVERGENCE IS EXPECTED TO INCREASE DRAMATICALLY
ACROSS THE CWFA BY SUNDAY AFTERNOON AND THE UPPER FLOW AMPLIFIES
AND DIFFLUENCE INCREASES MARKEDLY IN THE LEFT EXIT REGION OF THE
APPROACHING JET. THESE THINGS SUPPORT DEVELOPMENT AND ENHANCEMENT
OF PCPN ACROSS THE AREA ON SUNDAY WITH THIS INITIAL SURGE OF WARM
ADVECTION AND DEEP MOISTURE INTO THE AREA. PCPN-TYPE CONTINUES TO
BE THE PRIMARY ISSUE THAT WILL MITIGATE SNOWFALL POTENTIAL... AND
THERE IS GOOD AGREEMENT THAT WE SHOULD SEE SUFFICIENT WARM AIR
MOVE IN ALOFT TO CHANGE THINGS TO SLEET AND PERHAPS SOME FREEZING
RAIN FOR A TIME ACROSS THE SOUTHERN PORTION OF THE AREA... BEFORE
GOING OVER TO MAINLY RAIN FOR AT LEAST PART OF THE DAY. HOWEVER...
HEIGHTS CRASH QUICKLY BY SUNDAY EVENING AS THE UPPER LOW MOVES
INTO THE AREA... WHICH ALONG WITH DYNAMIC COOLING FROM SUSTAINED
UPWARD MOTION COULD HELP TO CHANGE THINGS BACK TO SNOW FAIRLY
QUICKLY DEPENDING UPON WHETHER THE AMOUNT OF WARM AIR WHICH MOVES
IN IS AS ROBUST AS THE GFS SUGGESTS OR CLOSER TO THE ECMWF AND
FIM. FOR NOW... KEPT THINGS ALL SNOW ACROSS THE NORTH AND
NORTHWEST... AND ALLOWED FOR MIXED PCPN UP THROUGH THE SOUTHERN
COUNTIES AND INTO THE NORTHERN TWIN CITIES METRO. THAT BEING
SAID... WITH PCPN TOTALS OF OVER SIX TENTHS OF AN INCH EXPECTED
OVER MUCH OF THE AREA... AND PERHAPS SOME CLOSE TO AN INCH... ANY
PERIOD OF SNOW COULD PUT DOWN DECENT ACCUMULATIONS. EXPECT
LOCATIONS THAT REMAIN ALL SNOW TO WIND UP BETWEEN 6 AND 10 FOR THE
MOST PART... ALTHOUGH LOCALLY HIGHER AMOUNTS COULD OCCUR DEPENDING
ON RATIOS... WHILE AMOUNTS WILL DECREASE QUICKLY AS ONE MOVES INTO
AREAS WHERE A GREATER PORTION OF THE PCPN IS OF MIXED-TYPE AND/OR
RAIN. AT THIS POINT... THE BEST GUESS FOR THE TWIN CITIES WOULD BE
FOR TOTAL AMOUNTS OF NEAR 6 INCHES... WITH THE NORTH AND NORTHWEST
SUBURBS SEEING THE GREATEST... BUT THAT COULD CERTAINLY CHANGE
DEPENDING UPON HOW THE STORM TRACK PANS OUT AND THE CHARACTER OF
WARM ADVECTION AHEAD OF IT. NEEDLESS TO SAY... THE SITUATION WILL
REQUIRE CONTINUED MONITORING... WITH UPDATES AND CHANGES LIKELY AS
WE HEAD THROUGH THE NEXT DAY OR TWO.
SOME SNOW SHOWERS CAN BE EXPECTED IN THE CYCLONIC FLOW ON THE
BACKSIDE OF THE SYSTEM THROUGH THE DAY ON MONDAY... WITH THINGS
DRYING OUT FOR GOOD ONCE HIGH PRESSURE WORKS IN MONDAY NIGHT AND
TUESDAY. BENIGN WEATHER THEN LOOKS TO PREDOMINATE THROUGH THE
BALANCE OF THE FORECAST PERIOD. AN ALBERTA CLIPPER COULD IMPACT
THE AREA BY THURSDAY... ALTHOUGH THERE ARE SOME DEFINITE TIMING
AND PLACEMENT DIFFERENCES BETWEEN THE GFS... ECMWF... AND THEIR
RESPECTIVE ENSEMBLES WITH RESPECT TO THAT... SO KEPT THINGS DRY
AFTER MONDAY FOR NOW.
&&
.AVIATION.../06Z TAF ISSUANCE/
PRIMARY TAF CONCERN IN CLEARING TREND OVERNIGHT. DRIER AIR OR
SUBSIDENCE BEHIND THE DEPARTING WISCONSIN WAVE IS BEGINNING TO POKE
SOME HOLES IN THE CLOUDS OVER THE AREA. IT APPEARS THIS WILL
CONTINUE WITH CLOUDS BREAKING UP THROUGH BY 12Z FRI. KRWF AND
PERHAPS KEAU SHOULD REMAIN IN THE CLOUDS THE LONGEST OVERNIGHT...WITH
KAXN ON THE EDGE OF IFR/LIFR STRATUS MOVING BACK INTO THE AREA.
RETURN SOUTHEAST FLOW SHOULD HELP KEEP AT LEAST MVFR CEILINGS OVER
WESTERN AREAS THROUGH THE MORNING WITH DRY CONDITIONS ELSEWHERE.
INCREASING SOUTHEAST WINDS MAY BECOME A BIT GUSTY IN THE AFTERNOON
AT KAXN. THE REMINDER SHOULD SHOULD REMAIN AOB 10 KNOTS DURING THE
DAY. SOME HIGH CLOUDS INTO FRIDAY NIGHT.
KMSP...
APPEARS CLEARING TREND WILL CONTINUE THIS MORNING. WILL SCATTER
LOW CLOUDS OUT AROUND 09Z AND HOLD ONTO TO THE TEMPO GROUP FOR FOG
POTENTIAL LATE. VFR THE REMAINDER OF THE PERIOD WITH PERHAPS SOME
MID CLOUDS MOVING IN LATE FRIDAY NIGHT AHEAD OF NEXT STORM SYSTEM.
SURFACE WINDS BECOMING MORE SOUTHEAST LATER FRIDAY MORNING AND
SHOULD REMAIN THERE THROUGH FRIDAY NIGHT.
/OUTLOOK FOR KMSP/
SAT...VFR. IFR DEVELOPING LATE WITH PRECIP MIX. WINDS SSE 10G15KTS.
SUN...IFR WITH RA/SN. SIGNIFICANT IMPACTS POSSIBLE. ESE AT 15G20KTS.
MON...IFR WITH SN IN MORNING...MVFR AFTERNOON. WINDS WNW 20G30KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH LATE SUNDAY
NIGHT FOR BENTON-CHIPPEWA-DOUGLAS-ISANTI-KANABEC-KANDIYOHI-
LAC QUI PARLE-MEEKER-MILLE LACS-MORRISON-POPE-SHERBURNE-
STEARNS-STEVENS-SWIFT-TODD-YELLOW MEDICINE.
WI...NONE.
&&
$$
TRH/DE
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
256 PM CST FRI FEB 8 2013
.SHORT TERM...
ISSUED AT 235 PM CST FRI FEB 8 2013
(TONIGHT)
AT 20Z...NW UPPER LEVEL FLOW DOMINATES THE MID MS VALLEY THIS
AFTERNOON WITH A MODESTLY AMPLIFIED RIDGE AXIS OVER THE PLAINS. AT
THE SFC...RIDGE AXIS EXTENDS FROM WRN WI INTO NWRN MO. SAT PIX
SHOWS EXTENSIVE AREA OF LO ST/SC CLOUD...BUT IT HAS BEEN SHRINKING
AND BEEN DISPLAYING FISSURES THE PAST FEW HRS...MOST NOTABLY OVER
SWRN-WRN MO AND PARTS OF IL. LARGE AREA OF THINNER CI CLOUDS ARE
SEEN SPILLING OVER THE UPPER LEVEL RIDGE JUST TO THE W OF MO. THESE
CLOUDS HAVE KEPT TEMPS DOWN WITH MINIMAL DIURNAL RISES SINCE EARLY
THIS MORNING...WITH READINGS IN THE 30S.
MAIN FCST PROBLEM IS RATHER PERSISTENT LO CLOUDS...STILL A HANGOVER
FROM YESTERDAY/S WX SYSTEM. FROM PREVIOUS UPDATED DISCUSSION LATE
THIS MORNING...MAIN OPPORTUNITIES FOR CLEARING WILL PRESENT
THEMSELVES WITH ANY ADDITIONAL DISSIPATION THAT THE SUN CAN DO OVER
THE NEXT HOUR OR TWO...AS THAT WINDOW IS STARTING TO CLOSE...WITH
HELP FROM ANY LOCALIZED AREAS OF DOWNSLOPE AND WHERE SUBSIDENCE CAN
BE STRONG ENOUGH WHERE THE LO CLOUD DECK IS THIN ENOUGH. FROM THAT
POINT HEADING INTO THE NIGHT...ADVECTION WILL THEN TAKE OVER...AND
SO FCST CONFIDENCE WILL INCREASE DRAMATICALLY ON THIS ISSUE BY EARLY
THIS EVENING ONCE DISSIPATION POTENTIAL IS GONE AND IT BECOMES ALL
ADVECTIVE PROCESSES.
FOR NOW...LOOKS LIKE BEST POTENTIAL WILL BE IN CNTRL IL WHERE CLOUDS
ARE ABOUT 500-600FT THICK AND WHATEVER CAN EDGE TOWARDS CNTRL-SERN
MO FROM AREAS THAT HAVE ALREADY CLEARED OUT FROM PRIMARILY DOWNSLOPE
PROCESSES. OTHERWISE...ONCE ADVECTION BECOMES THE ONLY GAME IN
TOWN...WILL NEED TO WAIT OUT THE LO LEVEL RIDGE UNTIL FLOW TURNS OUT
OF THE S LATE TONIGHT AND SATURDAY MORNING. BOTTOM LINE...LOOKS TO
BE CLOUDY FOR MOST AREAS FOR MUCH OF THE NIGHT.
THE UPPER LEVEL RIDGE AXIS WILL SLIDE E ACROSS OUR REGION TONIGHT
AND ALLOW THE ABUNDANT...MOSTLY THIN...CI CLOUDS TO OVERSPREAD BY
DAYBREAK. TEMPS WILL HAVE LITTLE CHANCE TO PLUNGE DESPITE SFC RIDGE
AXIS LIKEWISE SLIDING ACROSS OUR REGION WITH CLOUD ISSUES...TRADING
ONE CEILING FOR ANOTHER...ALBEIT HIGHER...ONE. WHERE LO CLOUDS ARE
EXPECTED TO TAKE THE LONGEST TO CLEAR...HAVE WENT THE MOST ABOVE MOS
FOR MIN TEMPS. OTHERWISE...PREFERRED NEAR THE WARMER MOS GUIDANCE
SINCE IT TENDED TO GO TOO OPTIMISTIC ON CLOUD COVER AS A RULE.
TES
&&
.LONG TERM...
ISSUED AT 253 PM CST FRI FEB 8 2013
(TOMORROW THROUGH NEXT THURSDAY)
WARM AND QUIET CONDITIONS ARE ANTICIPATED DURING THE DAY TOMORROW
WITH SELY WINDS AROUND THE BACK SIDE OF A SFC HIGH PRESSURE CENTER
AND RISING HEIGHTS ALOFT AHEAD OF AN APPROACHING LOW PRESSURE
SYSTEM. BUFKIT SOUNDINGS SHOW MIXING TO AROUND H92 WHICH SUPPORTS
AFTN HIGHS IN THE UPPER 40S TO LOWER 50S GIVEN H92 TEMPERATURES OF
2-5 DEGREES AND PLENTY OF INSOLATION.
A 40-50KT LLJ WILL TRANSPORT MOISTURE NWD ABOVE A WMFNT AS IT LIFTS
THROUGH AR INTO SRN MO ON SAT NIGHT. THESE PROCESSES WILL RESULT IN
PDS OF RAIN SHOWERS WITH EMBEDDED THUNDERSTORMS FROM LATE SAT NIGHT
THROUGH SUNDAY. THE PRESENCE OF THE RIDGE ACROSS THE CENTRAL PART OF
THE COUNTRY THROUGH TOMORROW WILL LIMIT THE AMOUNT OF MOISTURE
RETURN THAT OCCURS AHEAD OF THE EJECTING LOW PRESSURE SYSTEM.
ALTHOUGH THE DELAY IN MOISTURE RETURN WILL TEND TO LIMIT THE SEVERE
WEATHER POTENTIAL FOR OUR AREA...SOME OF THE EMBEDDED THUNDERSTORMS
COULD PRODUCE MODERATE RAINFALL AT TIMES DUE TO THE UNSEASONABLY
MOIST AIR MASS DEPICTED BY SREF/GFS/WRF FCSTS OF PW VALUES WHICH
RISE TO OVER 2 STDDEV ABOVE NORMAL FOR FEB IN THIS PART OF THE
COUNTRY. TEMPERATURES SHOULD BE AT LEAST AS WARM ON SUNDAY AS THEY
WERE ON SAT BECAUSE THE SFC WMFNT LIFTS THROUGH THE AREA DURING THE
MORNING AND BECAUSE IT LOOKS LIKE A DRY SLOT MOVES ACROSS THE AREA
DURING THE AFTN LEADING TO LESS CLOUD COVER AND MORE INSOLATION
ACROSS SOME PARTS OF THE CWA. A CDFNT WILL THEN SWEEP ACROSS THE
CWA DURING THE LATE AFTN AND EARLY EVENING HOURS. NO PCPN IS
EXPECTED BEHIND THE FRONT DUE TO STRONG ISENTROPIC DOWNGLIDE.
ANOTHER LOW PRESSURE SYSTEM DVLPS ACROSS THE SWRN CONUS IN THE WAKE
OF SUNDAYS SYSTEM. MODEL GUIDANCE SEEMS TO BE SETTLING ON A SRN
SOLUTION WITH THE TRACK OF THE VORT MAX REMAINING SOUTH OF THE CWA
ON TUE NIGHT AND WED. MODELS ALSO SHOW A COUPLE OF SHORTWAVES
CROSSING THE ROCKIES ON WED AND MOVING INTO THE PLAINS ON THU
HOWEVER THERE IS SOME DISAGREEMENT BETWEEN THE 12Z ECMWF/GFS ON THE
DEGREE OF INTERACTION BETWEEN SHORTWAVES AND ON HOW FAR SOUTH THEY
WILL DIG.
KANOFSKY
&&
.AVIATION...
ISSUED AT 1145 AM CST FRI FEB 8 2013
CONTINUE TO TREND MORE PESSIMISTIC WITH CIGS AND CONDITIONS THRU
THRU THE REST OF TODAY AND INTO TONIGHT. RAP SEEMS TO HAVE A GOOD
HANDLE ON TRENDS...SEE UPDATED DISCUSSION ABOVE FOR A MORE
TECHNICAL DESCRIPTION...BUT SHOULD SEE SOME CLEARING FOR KCOU BUT
MS RIVER AXIS WILL BE WHERE THE DIE-HARD CLOUDS LINGER. BEST
POTENTIAL FOR KCOU TO LOSE THEIR CIG WILL BE AFTER 21Z WHERE THEY
SHOULD BE VERY CLOSE AND MAY EVEN MOVE IN AND OUT DURING THIS
PERIOD UNTIL LATE EVENING WHEN LO CLOUDS SHOULD EXIT FOR GOOD. STL
METRO SITES ALSO SHOULD CLEAR LATER THIS EVENING AS WELL AS SE
WINDS ALOFT KICK IN AND BENEFIT FROM WHAT SHOULD BE A CLEARING
AREA TO OUR S...WITH KUIN THE LAST TO LOSE THE LO CIG IF ALL GOES
AS EXPECTED. THERE IS SOME POTENTIAL THAT STEERING WINDS WILL BE
TOO LIGHT WITH RIDGE THAT LO CLOUDS WILL LINGER LONGER THAN
EXPECTED. NET EFFECT WILL BE LOSE ONE CIG FOR ANOTHER IN MOST
CASES BUT IT WILL BE A MVFR FOR A VFR AS HI CI CLOUDS OVERSPREAD
THE AREA TOWARD DAYBREAK SATURDAY. N-NE SFC WNDS WILL BECOME LIGHT
AND VRBL WITH RIDGE PASSAGE AND THEN SE ON SATURDAY.
SPECIFICS FOR KSTL...MVFR CIGS TO CONTINUE INTO THE EVENING...
CLEARING EXPECTED BEFORE MIDNIGHT BUT MAY CONTINUE FARTHER IF
WINDS AT CLOUD LEVEL ARE VERY LIGHT...WITH VFR CIGS FROM CI CLOUDS
LATE TONIGHT AND INTO SATURDAY. N-NE SFC WNDS LESS THAN 10KTS
VEERING SE BY SATURDAY.
TES
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 29 50 39 58 / 0 0 60 80
QUINCY 27 47 36 52 / 0 5 60 80
COLUMBIA 27 53 40 60 / 0 5 80 80
JEFFERSON CITY 27 54 41 61 / 0 5 80 80
SALEM 24 47 38 53 / 0 0 40 100
FARMINGTON 25 52 39 55 / 0 5 60 90
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
235 PM CST FRI FEB 8 2013
.SHORT TERM...
ISSUED AT 235 PM CST FRI FEB 8 2013
(TONIGHT)
AT 20Z...NW UPPER LEVEL FLOW DOMINATES THE MID MS VALLEY THIS
AFTERNOON WITH A MODESTLY AMPLIFIED RIDGE AXIS OVER THE PLAINS. AT
THE SFC...RIDGE AXIS EXTENDS FROM WRN WI INTO NWRN MO. SAT PIX
SHOWS EXTENSIVE AREA OF LO ST/SC CLOUD...BUT IT HAS BEEN SHRINKING
AND BEEN DISPLAYING FISSURES THE PAST FEW HRS...MOST NOTABLY OVER
SWRN-WRN MO AND PARTS OF IL. LARGE AREA OF THINNER CI CLOUDS ARE
SEEN SPILLING OVER THE UPPER LEVEL RIDGE JUST TO THE W OF MO. THESE
CLOUDS HAVE KEPT TEMPS DOWN WITH MINIMAL DIURNAL RISES SINCE EARLY
THIS MORNING...WITH READINGS IN THE 30S.
MAIN FCST PROBLEM IS RATHER PERSISTENT LO CLOUDS...STILL A HANGOVER
FROM YESTERDAY/S WX SYSTEM. FROM PREVIOUS UPDATED DISCUSSION LATE
THIS MORNING...MAIN OPPORTUNITIES FOR CLEARING WILL PRESENT
THEMSELVES WITH ANY ADDITIONAL DISSIPATION THAT THE SUN CAN DO OVER
THE NEXT HOUR OR TWO...AS THAT WINDOW IS STARTING TO CLOSE...WITH
HELP FROM ANY LOCALIZED AREAS OF DOWNSLOPE AND WHERE SUBSIDENCE CAN
BE STRONG ENOUGH WHERE THE LO CLOUD DECK IS THIN ENOUGH. FROM THAT
POINT HEADING INTO THE NIGHT...ADVECTION WILL THEN TAKE OVER...AND
SO FCST CONFIDENCE WILL INCREASE DRAMATICALLY ON THIS ISSUE BY EARLY
THIS EVENING ONCE DISSIPATION POTENTIAL IS GONE AND IT BECOMES ALL
ADVECTIVE PROCESSES.
FOR NOW...LOOKS LIKE BEST POTENTIAL WILL BE IN CNTRL IL WHERE CLOUDS
ARE ABOUT 500-600FT THICK AND WHATEVER CAN EDGE TOWARDS CNTRL-SERN
MO FROM AREAS THAT HAVE ALREADY CLEARED OUT FROM PRIMARILY DOWNSLOPE
PROCESSES. OTHERWISE...ONCE ADVECTION BECOMES THE ONLY GAME IN
TOWN...WILL NEED TO WAIT OUT THE LO LEVEL RIDGE UNTIL FLOW TURNS OUT
OF THE S LATE TONIGHT AND SATURDAY MORNING. BOTTOM LINE...LOOKS TO
BE CLOUDY FOR MOST AREAS FOR MUCH OF THE NIGHT.
THE UPPER LEVEL RIDGE AXIS WILL SLIDE E ACROSS OUR REGION TONIGHT
AND ALLOW THE ABUNDANT...MOSTLY THIN...CI CLOUDS TO OVERSPREAD BY
DAYBREAK. TEMPS WILL HAVE LITTLE CHANCE TO PLUNGE DESPITE SFC RIDGE
AXIS LIKEWISE SLIDING ACROSS OUR REGION WITH CLOUD ISSUES...TRADING
ONE CEILING FOR ANOTHER...ALBEIT HIGHER...ONE. WHERE LO CLOUDS ARE
EXPECTED TO TAKE THE LONGEST TO CLEAR...HAVE WENT THE MOST ABOVE MOS
FOR MIN TEMPS. OTHERWISE...PREFERRED NEAR THE WARMER MOS GUIDANCE
SINCE IT TENDED TO GO TOO OPTIMISTIC ON CLOUD COVER AS A RULE.
TES
&&
.LONG TERM...
ISSUED AT 330 AM CST FRI FEB 8 2013
(TONIGHT THROUGH THURSDAY)
SURFACE RIDGE TO MOVE OFF TO THE EAST TONIGHT ALLOWING SOUTHEASTERLY
WINDS TO RETURN TO THE AREA. HOWEVER...WITH CLEAR SKIES AND LIGHT
SOUTHEAST WINDS...TEMPERATURES WILL BE COOLER THAN THIS MORNINGS
TEMPS...IN THE MID TO UPPER 20S.
BY SATURDAY...DESPITE HIGH CLOUDS MOVING IN AHEAD OF NEXT WEATHER
SYSTEM...INCREASING SOUTH WINDS AND DECENT MIXING WILL ALLOW TEMPS
TO WARM UP INTO THE UPPER 40S TO LOW 50S...ABOUT 5 TO 10 DEGREES
ABOVE NORMAL FOR THIS TIME OF YEAR.
AS WARM FRONT ASSOCIATED WITH NEXT WEATHER SYSTEM LIFTS NORTHWARD
THROUGH AREA SATURDAY NIGHT...WILL SEE ELEVATED CONVECTION DEVELOP
AND SPREAD NORTHEASTWARD ACROSS FORECAST AREA. NOT A LOT OF
INSTABILITY...SO JUST HAVE SILENT SLIGHT CHANCE MENTION OF
THUNDERSTORMS IN WEATHER GRIDS FOR NOW. LOWS SATURDAY NIGHT WILL BE
IN THE MID 30S TO LOW 40S.
WILL HAVE BETTER CHANCES OF THUNDERSTORMS ON SUNDAY WITH MAIN COLD
FRONT AS IT SLIDES QUICKLY EAST THROUGH FORECAST AREA. DESPITE
DECENT SHEAR/HELICITY AND DEWPTS IN THE MID TO UPPER 40S...NO SEVERE
WEATHER EXPECTED AT THIS TIME AS BEST INSTABILITIES AND MOISTURE
RETURN WILL BE FURTHER SOUTH OVER THE LOWER MISSISSIPPI VALLEY.
HIGHS WILL BE IN THE LOW 50S TO LOW 60S.
PCPN TO SHUT OFF PRETTY QUICK SUNDAY EVENING WITH COLDER AIR
FILTERING IN...BUT REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR...IN
THE 30S.
BEYOND THAT...KEPT EXTENDED DRY FOR NOW AS MODELS KEEP NEXT
SIGNIFICANT SHORTWAVE FURTHER TO THE SOUTH...THUS PCPN ASSOCIATED
WITH IT REMAINS TO THE SOUTH OF FORECAST AREA MID WEEK.
OTHERWISE...COLDER AIR TO FILTER IN BY TUESDAY WITH HIGHS DIPPING
INTO THE MID 30S TO MID 40S...THEN MODERATE BY THE END OF THE
FORECAST PERIOD AS SURFACE RIDGE BECOMES ANCHORED OVER LOWER
MISSISSIPPI RIVER VALLEY. HIGHS BY THURSDAY WILL BE BACK IN THE
UPPER 40S TO LOW 50S.
BYRD
&&
.AVIATION...
ISSUED AT 1145 AM CST FRI FEB 8 2013
CONTINUE TO TREND MORE PESSIMISTIC WITH CIGS AND CONDITIONS THRU
THRU THE REST OF TODAY AND INTO TONIGHT. RAP SEEMS TO HAVE A GOOD
HANDLE ON TRENDS...SEE UPDATED DISCUSSION ABOVE FOR A MORE
TECHNICAL DESCRIPTION...BUT SHOULD SEE SOME CLEARING FOR KCOU BUT
MS RIVER AXIS WILL BE WHERE THE DIE-HARD CLOUDS LINGER. BEST
POTENTIAL FOR KCOU TO LOSE THEIR CIG WILL BE AFTER 21Z WHERE THEY
SHOULD BE VERY CLOSE AND MAY EVEN MOVE IN AND OUT DURING THIS
PERIOD UNTIL LATE EVENING WHEN LO CLOUDS SHOULD EXIT FOR GOOD. STL
METRO SITES ALSO SHOULD CLEAR LATER THIS EVENING AS WELL AS SE
WINDS ALOFT KICK IN AND BENEFIT FROM WHAT SHOULD BE A CLEARING
AREA TO OUR S...WITH KUIN THE LAST TO LOSE THE LO CIG IF ALL GOES
AS EXPECTED. THERE IS SOME POTENTIAL THAT STEERING WINDS WILL BE
TOO LIGHT WITH RIDGE THAT LO CLOUDS WILL LINGER LONGER THAN
EXPECTED. NET EFFECT WILL BE LOSE ONE CIG FOR ANOTHER IN MOST
CASES BUT IT WILL BE A MVFR FOR A VFR AS HI CI CLOUDS OVERSPREAD
THE AREA TOWARD DAYBREAK SATURDAY. N-NE SFC WNDS WILL BECOME LIGHT
AND VRBL WITH RIDGE PASSAGE AND THEN SE ON SATURDAY.
SPECIFICS FOR KSTL...MVFR CIGS TO CONTINUE INTO THE EVENING...
CLEARING EXPECTED BEFORE MIDNIGHT BUT MAY CONTINUE FARTHER IF
WINDS AT CLOUD LEVEL ARE VERY LIGHT...WITH VFR CIGS FROM CI CLOUDS
LATE TONIGHT AND INTO SATURDAY. N-NE SFC WNDS LESS THAN 10KTS
VEERING SE BY SATURDAY.
TES
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 29 50 39 58 / 0 0 60 80
QUINCY 27 47 36 52 / 0 5 60 80
COLUMBIA 27 53 40 60 / 0 5 80 80
JEFFERSON CITY 27 54 41 61 / 0 5 80 80
SALEM 24 47 38 53 / 0 0 40 100
FARMINGTON 25 52 39 55 / 0 5 60 90
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1145 AM CST FRI FEB 8 2013
.UPDATE...
ISSUED AT 1100 AM CST FRI FEB 8 2013
LATEST NWP GUIDANCE SHOWS STEERING WINDS AT CLOUD LEVEL OUT OF THE
N-NE THRU THE DAY TODAY...SO CLEARING BY ADVECTION IS NOT GOING TO
HAPPEN. SUN ANGLE IS STRONGER NOW THAN IT WAS LAST MONTH...BUT IT
WILL STILL NEED HELP...AND APPROACHING /DIRTY RIDGE/ AXIS OVER
CNTRL IA AND NWRN MO WILL PROMOTE SOME SUBSIDENCE TODAY...MOST
NOTABLY OVER CNTRL IL. PIREPS SHOW THE THINNEST CLOUD DECKS... OF
AROUND 1KFT...ARE OVER NWRN IL AND SWRN MO AND SO THESE WILL BE
THE FIRST TO GO...THE LATTER ALSO FROM DOWNSLOPE FROM THE OZARK
PLATEAU FROM NE SFC WND COMPONENT.
SO...LOOK FOR SOME CLEARING TO OCCUR TO OUR NE IN CNTRL IL AS WELL
AS TO OUR SW OVER THE OZARKS AND WRN MO. THIS WILL PLACE MOST OF
OUR FA...ESPECIALLY NEAR THE MS RIVER...STILL IN THE CLOUDY ZONE
FOR TODAY SAVE THE SERN MO AREAS WHICH SHOULD SEE SOME SUN THIS
AFTERNOON.
CONDITIONAL CLIMO WITH LO CIGS AND NE SFC WNDS SHOW LITTLE IF ANY
DIURNAL BOUNCE...SO HAVE TRIMMED TEMPS TO MAXES IN THE 30S FOR
MOST OF THE REGION EXCEPT LO 40S IN SERN MO AND ARND 40 IN CNTRL
MO.
CLOUDS MAY ACTUALLY BUILD BACK INTO CNTRL MO FOR A PERIOD THIS
EVENING BEFORE VEERING CLOUD LEVEL WINDS TO THE SE FINALLY PUSH
THEM OUT LATER TONIGHT ONLY TO BE REPLACED WITH THIN CI CLOUDS
TOWARD DAYBREAK.
TES
&&
.SHORT TERM...
ISSUED AT 221 AM CST FRI FEB 8 2013
(TODAY)
SFC HIGH WILL CONTINUE TO BUILD INTO THE REGION THROUGH THE DAY. MAX
TEMPS ARE THE FCST CHALLENGE TODAY. NEW MODEL GUIDANCE INDICATES
STRATUS WILL STICK AROUND LONGER THAN PREVIOUSLY ANTICIPATED...WITH
CLOUDY/MOSTLY CLOUDY CONDITIONS LASTING INTO THE AFTN. THEREFORE
HIGH TEMPS HAVE BEEN LOWERED BY ABOUT 5 DEGREES ACROSS THE
BOARD...DEPENDING ON WHAT THE CLOUDS ACTUALLY DO...THAT MAY OR
MAY NOT BE A SMART MOVE. IF THE CLOUDS BREAK UP PRIOR TO
NOON...THEN HIGHS ARE NOW PROBABLY TOO COOL...BUT IF THEY HANG
TOUGH THROUGH THE AFTN...THEN I/M PROBABLY STILL TOO WARM. AREA
SHOULD REMAIN IN CAA THROUGH THE DAY WITH THE SFC RIDGE AXIS NOT
CROSSING THE CWA UNTIL THIS EVENING. LOCAL CLIMO SUGGESTS THAT
TEMPS SHOULD REMAIN NEARLY STEADY TODAY. IN THIS INSTANCE...THAT
SEEMS A BIT AGGRESSIVE AS 850 AND 925 TEMPS ACTUALLY RISE DURING
THE AFTN.
2%
&&
.LONG TERM...
ISSUED AT 330 AM CST FRI FEB 8 2013
(TONIGHT THROUGH THURSDAY)
SURFACE RIDGE TO MOVE OFF TO THE EAST TONIGHT ALLOWING SOUTHEASTERLY
WINDS TO RETURN TO THE AREA. HOWEVER...WITH CLEAR SKIES AND LIGHT
SOUTHEAST WINDS...TEMPERATURES WILL BE COOLER THAN THIS MORNINGS
TEMPS...IN THE MID TO UPPER 20S.
BY SATURDAY...DESPITE HIGH CLOUDS MOVING IN AHEAD OF NEXT WEATHER
SYSTEM...INCREASING SOUTH WINDS AND DECENT MIXING WILL ALLOW TEMPS
TO WARM UP INTO THE UPPER 40S TO LOW 50S...ABOUT 5 TO 10 DEGREES
ABOVE NORMAL FOR THIS TIME OF YEAR.
AS WARM FRONT ASSOCIATED WITH NEXT WEATHER SYSTEM LIFTS NORTHWARD
THROUGH AREA SATURDAY NIGHT...WILL SEE ELEVATED CONVECTION DEVELOP
AND SPREAD NORTHEASTWARD ACROSS FORECAST AREA. NOT A LOT OF
INSTABILITY...SO JUST HAVE SILENT SLIGHT CHANCE MENTION OF
THUNDERSTORMS IN WEATHER GRIDS FOR NOW. LOWS SATURDAY NIGHT WILL BE
IN THE MID 30S TO LOW 40S.
WILL HAVE BETTER CHANCES OF THUNDERSTORMS ON SUNDAY WITH MAIN COLD
FRONT AS IT SLIDES QUICKLY EAST THROUGH FORECAST AREA. DESPITE
DECENT SHEAR/HELICITY AND DEWPTS IN THE MID TO UPPER 40S...NO SEVERE
WEATHER EXPECTED AT THIS TIME AS BEST INSTABILITIES AND MOISTURE
RETURN WILL BE FURTHER SOUTH OVER THE LOWER MISSISSIPPI VALLEY.
HIGHS WILL BE IN THE LOW 50S TO LOW 60S.
PCPN TO SHUT OFF PRETTY QUICK SUNDAY EVENING WITH COLDER AIR
FILTERING IN...BUT REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR...IN
THE 30S.
BEYOND THAT...KEPT EXTENDED DRY FOR NOW AS MODELS KEEP NEXT
SIGNIFICANT SHORTWAVE FURTHER TO THE SOUTH...THUS PCPN ASSOCIATED
WITH IT REMAINS TO THE SOUTH OF FORECAST AREA MID WEEK.
OTHERWISE...COLDER AIR TO FILTER IN BY TUESDAY WITH HIGHS DIPPING
INTO THE MID 30S TO MID 40S...THEN MODERATE BY THE END OF THE
FORECAST PERIOD AS SURFACE RIDGE BECOMES ANCHORED OVER LOWER
MISSISSIPPI RIVER VALLEY. HIGHS BY THURSDAY WILL BE BACK IN THE
UPPER 40S TO LOW 50S.
BYRD
&&
.AVIATION...
ISSUED AT 1145 AM CST FRI FEB 8 2013
CONTINUE TO TREND MORE PESSIMISTIC WITH CIGS AND CONDITIONS THRU
THRU THE REST OF TODAY AND INTO TONIGHT. RAP SEEMS TO HAVE A GOOD
HANDLE ON TRENDS...SEE UPDATED DISCUSSION ABOVE FOR A MORE
TECHNICAL DESCRIPTION...BUT SHOULD SEE SOME CLEARING FOR KCOU BUT
MS RIVER AXIS WILL BE WHERE THE DIE-HARD CLOUDS LINGER. BEST
POTENTIAL FOR KCOU TO LOSE THEIR CIG WILL BE AFTER 21Z WHERE THEY
SHOULD BE VERY CLOSE AND MAY EVEN MOVE IN AND OUT DURING THIS
PERIOD UNTIL LATE EVENING WHEN LO CLOUDS SHOULD EXIT FOR GOOD. STL
METRO SITES ALSO SHOULD CLEAR LATER THIS EVENING AS WELL AS SE
WINDS ALOFT KICK IN AND BENEFIT FROM WHAT SHOULD BE A CLEARING
AREA TO OUR S...WITH KUIN THE LAST TO LOSE THE LO CIG IF ALL GOES
AS EXPECTED. THERE IS SOME POTENTIAL THAT STEERING WINDS WILL BE
TOO LIGHT WITH RIDGE THAT LO CLOUDS WILL LINGER LONGER THAN
EXPECTED. NET EFFECT WILL BE LOSE ONE CIG FOR ANOTHER IN MOST
CASES BUT IT WILL BE A MVFR FOR A VFR AS HI CI CLOUDS OVERSPREAD
THE AREA TOWARD DAYBREAK SATURDAY. N-NE SFC WNDS WILL BECOME LIGHT
AND VRBL WITH RIDGE PASSAGE AND THEN SE ON SATURDAY.
SPECIFICS FOR KSTL...MVFR CIGS TO CONTINUE INTO THE EVENING...
CLEARING EXPECTED BEFORE MIDNIGHT BUT MAY CONTINUE FARTHER IF
WINDS AT CLOUD LEVEL ARE VERY LIGHT...WITH VFR CIGS FROM CI CLOUDS
LATE TONIGHT AND INTO SATURDAY. N-NE SFC WNDS LESS THAN 10KTS
VEERING SE BY SATURDAY.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1140 AM CST Fri Feb 8 2013
...UPDATED AVIATION DISCUSSION...
.UPDATE...
/1014 AM CST Fri Feb 8 2013/
Stratus shield shows little signs of dissipating except in far
southwestern portions of the forecast area, so have increased sky
cover and lowered high temperatures for much of the forecast area.
Will need to continue to monitor the erosion of cloud cover and
temperature trends in the southwest over the next several hours.
Laflin
&&
.DISCUSSION...
Short Range (Today through Sunday)...
The weather will become progressively more interesting Saturday
night and Sunday. Until then the main concern will be how soon
before the stratus departs. A large area of stratus has expanded
south-southwest under a surface ridge which extends from MN through
eastern KS and northwest TX. Except for the RAP the models are doing
a poor job handling this cloud cover. Part of that is due to a lack
of depth to the cloud cover. Latest RAP soundings via Bufkit and
AvnFPS climatology suggest the stratus could very well hang around
into the afternoon hours...especially east of the surface ridge. For
now,
will side on a rapid break up this afternoon but will pass along
concerns to the day shift. Should cloudy skies linger through the
afternoon the current high temperatures will prove to be too
optimistic.
Primary attention will then focus on the deep upper trough now
moving through CA. Models are in good agreement in deepening this
system as it tracks east as a positively tilted system. The main
piece of energy is still expected to lift northeast and through the
Central Plains Saturday night and Sunday. Very strong mid/upper
level dynamics will result in large pressure falls downstream and a
deepening surface cyclone. While the wind shear parameters will be
quite strong and supportive of severe weather the key to it forming
will be the quality of low level moisture return. It currently
appears the low level moisture will be lacking by the time the
associated pre-frontal convergence zone reaches the CWA Sunday
morning. Thus the lack of sufficient instability will be a deterrent
to severe storm formation. However, the strength of the 0-6km bulk
shear will be supportive of fast moving storms which could produce
strong winds. In addition, the shear may be so strong as to shear
away the tops of any storms and thus destroy the vertical
structure/updraft.
Best bet for showers and thunderstorms will be Saturday night and
Sunday morning.
MJ
Medium Range (Monday through Friday)...
Expect mainly dry conditions with a bit of a roller coaster ride for
temperatures during the work week next week. By Monday, the system
that brings showers and thunderstorms to the forecast area Saturday
night into Sunday, will shift northeastward into the Great Lakes.
With no real cold air behind the cold front that moves through the
area Sunday, temperatures on Monday will hover near average in the
upper 30s to mid 40s. On Tuesday an upper level trough will move
through the area. Precipitation associated with this system will
remain south of the area but it will knock highs down a few degrees.
Height rises from weak upper level ridging building into the area
and downsloping westerly flow will help temperatures move above
average Wednesday. Highs will be in the 40s. Temperatures will climb
further on Thursday out ahead of the next storm system. There will
be a return to southwesterly flow allowing temperatures to rise into
the mid 40s to lower 50s. A cold front will move through the area
Thursday night however models are not in agreement on precipitation.
The GFS brings snow to the entire CWA behind the front while the EC
digs an upper level trough, associated with the aforementioned cold
front, further south with rain or snow affecting the southern CWA.
Have maintained the slight chance pops the initialization painted
across the southern CWA for Friday. One certainty is temperatures
will be cooler on Friday with strong cold air advection keeping
highs in the 30s across the CWA.
73
&&
.AVIATION...
For the 18z TAFs... The large expanse of low-end MVFR to marginally
IFR stratus finally beginning to show signs of erosion in southern
and west central Missouri this afternoon, likely scattering out
ceilings in the KC area over the next 1-2 hours. Clearing will build
very slowly eastward this afternoon, but areas of north central and
eastern Missouri may not clear until well after sunset. Winds will
slowly back to the south today through tonight, and may gust out of
the south at 25 to 30 kts by late morning Saturday.
Laflin
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1100 AM CST FRI FEB 8 2013
.UPDATE...
ISSUED AT 1100 AM CST FRI FEB 8 2013
LATEST NWP GUIDANCE SHOWS STEERING WINDS AT CLOUD LEVEL OUT OF THE
N-NE THRU THE DAY TODAY...SO CLEARING BY ADVECTION IS NOT GOING TO
HAPPEN. SUN ANGLE IS STRONGER NOW THAN IT WAS LAST MONTH...BUT IT
WILL STILL NEED HELP...AND APPROACHING /DIRTY RIDGE/ AXIS OVER
CNTRL IA AND NWRN MO WILL PROMOTE SOME SUBSIDENCE TODAY...MOST
NOTABLY OVER CNTRL IL. PIREPS SHOW THE THINNEST CLOUD DECKS... OF
AROUND 1KFT...ARE OVER NWRN IL AND SWRN MO AND SO THESE WILL BE
THE FIRST TO GO...THE LATTER ALSO FROM DOWNSLOPE FROM THE OZARK
PLATEAU FROM NE SFC WND COMPONENT.
SO...LOOK FOR SOME CLEARING TO OCCUR TO OUR NE IN CNTRL IL AS WELL
AS TO OUR SW OVER THE OZARKS AND WRN MO. THIS WILL PLACE MOST OF
OUR FA...ESPECIALLY NEAR THE MS RIVER...STILL IN THE CLOUDY ZONE
FOR TODAY SAVE THE SERN MO AREAS WHICH SHOULD SEE SOME SUN THIS
AFTERNOON.
CONDITIONAL CLIMO WITH LO CIGS AND NE SFC WNDS SHOW LITTLE IF ANY
DIURNAL BOUNCE...SO HAVE TRIMMED TEMPS TO MAXES IN THE 30S FOR
MOST OF THE REGION EXCEPT LO 40S IN SERN MO AND ARND 40 IN CNTRL
MO.
CLOUDS MAY ACTUALLY BUILD BACK INTO CNTRL MO FOR A PERIOD THIS
EVENING BEFORE VEERING CLOUD LEVEL WINDS TO THE SE FINALLY PUSH
THEM OUT LATER TONIGHT ONLY TO BE REPLACED WITH THIN CI CLOUDS
TOWARD DAYBREAK.
TES
&&
.SHORT TERM...
ISSUED AT 221 AM CST FRI FEB 8 2013
(TODAY)
SFC HIGH WILL CONTINUE TO BUILD INTO THE REGION THROUGH THE DAY. MAX
TEMPS ARE THE FCST CHALLENGE TODAY. NEW MODEL GUIDANCE INDICATES
STRATUS WILL STICK AROUND LONGER THAN PREVIOUSLY ANTICIPATED...WITH
CLOUDY/MOSTLY CLOUDY CONDITIONS LASTING INTO THE AFTN. THEREFORE
HIGH TEMPS HAVE BEEN LOWERED BY ABOUT 5 DEGREES ACROSS THE
BOARD...DEPENDING ON WHAT THE CLOUDS ACTUALLY DO...THAT MAY OR
MAY NOT BE A SMART MOVE. IF THE CLOUDS BREAK UP PRIOR TO
NOON...THEN HIGHS ARE NOW PROBABLY TOO COOL...BUT IF THEY HANG
TOUGH THROUGH THE AFTN...THEN I/M PROBABLY STILL TOO WARM. AREA
SHOULD REMAIN IN CAA THROUGH THE DAY WITH THE SFC RIDGE AXIS NOT
CROSSING THE CWA UNTIL THIS EVENING. LOCAL CLIMO SUGGESTS THAT
TEMPS SHOULD REMAIN NEARLY STEADY TODAY. IN THIS INSTANCE...THAT
SEEMS A BIT AGGRESSIVE AS 850 AND 925 TEMPS ACTUALLY RISE DURING
THE AFTN.
2%
&&
.LONG TERM...
ISSUED AT 330 AM CST FRI FEB 8 2013
(TONIGHT THROUGH THURSDAY)
SURFACE RIDGE TO MOVE OFF TO THE EAST TONIGHT ALLOWING SOUTHEASTERLY
WINDS TO RETURN TO THE AREA. HOWEVER...WITH CLEAR SKIES AND LIGHT
SOUTHEAST WINDS...TEMPERATURES WILL BE COOLER THAN THIS MORNINGS
TEMPS...IN THE MID TO UPPER 20S.
BY SATURDAY...DESPITE HIGH CLOUDS MOVING IN AHEAD OF NEXT WEATHER
SYSTEM...INCREASING SOUTH WINDS AND DECENT MIXING WILL ALLOW TEMPS
TO WARM UP INTO THE UPPER 40S TO LOW 50S...ABOUT 5 TO 10 DEGREES
ABOVE NORMAL FOR THIS TIME OF YEAR.
AS WARM FRONT ASSOCIATED WITH NEXT WEATHER SYSTEM LIFTS NORTHWARD
THROUGH AREA SATURDAY NIGHT...WILL SEE ELEVATED CONVECTION DEVELOP
AND SPREAD NORTHEASTWARD ACROSS FORECAST AREA. NOT A LOT OF
INSTABILITY...SO JUST HAVE SILENT SLIGHT CHANCE MENTION OF
THUNDERSTORMS IN WEATHER GRIDS FOR NOW. LOWS SATURDAY NIGHT WILL BE
IN THE MID 30S TO LOW 40S.
WILL HAVE BETTER CHANCES OF THUNDERSTORMS ON SUNDAY WITH MAIN COLD
FRONT AS IT SLIDES QUICKLY EAST THROUGH FORECAST AREA. DESPITE
DECENT SHEAR/HELICITY AND DEWPTS IN THE MID TO UPPER 40S...NO SEVERE
WEATHER EXPECTED AT THIS TIME AS BEST INSTABILITIES AND MOISTURE
RETURN WILL BE FURTHER SOUTH OVER THE LOWER MISSISSIPPI VALLEY.
HIGHS WILL BE IN THE LOW 50S TO LOW 60S.
PCPN TO SHUT OFF PRETTY QUICK SUNDAY EVENING WITH COLDER AIR
FILTERING IN...BUT REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR...IN
THE 30S.
BEYOND THAT...KEPT EXTENDED DRY FOR NOW AS MODELS KEEP NEXT
SIGNIFICANT SHORTWAVE FURTHER TO THE SOUTH...THUS PCPN ASSOCIATED
WITH IT REMAINS TO THE SOUTH OF FORECAST AREA MID WEEK.
OTHERWISE...COLDER AIR TO FILTER IN BY TUESDAY WITH HIGHS DIPPING
INTO THE MID 30S TO MID 40S...THEN MODERATE BY THE END OF THE
FORECAST PERIOD AS SURFACE RIDGE BECOMES ANCHORED OVER LOWER
MISSISSIPPI RIVER VALLEY. HIGHS BY THURSDAY WILL BE BACK IN THE
UPPER 40S TO LOW 50S.
BYRD
&&
.AVIATION...
ISSUED AT 528 AM CST FRI FEB 8 2013
A SFC RIDGE IS EXPECTED TO BUILD INTO THE REGION THROUGH THE DAY.
THE SFC RIDGE SLIDES EAST THIS EVENING PUTTING THE AREA IN SE
RETURN FLOW BY SATURDAY MORNING. IFR CIGS HAVE SLOWLY RAISED ALL
NIGHT WITH CIGS AT MOST LOCATIONS AOA 1KFT. THE MAIN FCST
CHALLENGE WILL BE DETERMINING WHEN AND IF THE STRATUS WILL
DISSIPATE. MOST MODEL GUIDANCE HAS THE STRATUS BREAKING UP LATE
MORNING INTO THE AFTN. I THINK THIS MAY BE TOO OPTIMISTIC. GIVEN
THE AMOUNT OF STRATUS ALREADY IN PLACE AND THE FACT THAT THE WINDS
ARE EXPECTED TO BECOME NERLY LATER TODAY IS NOT A CLIMATOLOGICALLY
FAVORABLE SET UP FOR THE DISSIPATION OF STRATUS. THIS SCENARIO IS
SUPPORTED BY THE RUC MODEL. CIG DISSIPATION WAS PUSHED BACK WITH
THIS PACKAGE...BUT THE TIMING MAY NEED TO BE PUSHED BACK EVEN
FURTHER WITH SUBSEQUENT FCST ISSUANCES.
SPECIFICS FOR KSTL...MVFR CIG SHOULD SCATTER OUT THIS
AFTN...THOUGH THIS TIMING MAY BE TOO OPTIMISTIC. WINDS WILL VEER
FROM NORTH TO SE AS SFC HIGH SLIDES EAST THIS EVENING.
2%
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1016 AM CST Fri Feb 8 2013
.UPDATE...
/1014 AM CST Fri Feb 8 2013/
Stratus shield shows little signs of dissipating except in far
southwestern portions of the forecast area, so have increased sky
cover and lowered high temperatures for much of the forecast area.
Will need to continue to monitor the erosion of cloud cover and
temperature trends in the southwest over the next several hours.
Laflin
&&
.DISCUSSION...
Short Range (Today through Sunday)...
The weather will become progressively more interesting Saturday
night and Sunday. Until then the main concern will be how soon
before the stratus departs. A large area of stratus has expanded
south-southwest under a surface ridge which extends from MN through
eastern KS and northwest TX. Except for the RAP the models are doing
a poor job handling this cloud cover. Part of that is due to a lack
of depth to the cloud cover. Latest RAP soundings via Bufkit and
AvnFPS climatology suggest the stratus could very well hang around
into the afternoon hours...especially east of the surface ridge. For
now,
will side on a rapid break up this afternoon but will pass along
concerns to the day shift. Should cloudy skies linger through the
afternoon the current high temperatures will prove to be too
optimistic.
Primary attention will then focus on the deep upper trough now
moving through CA. Models are in good agreement in deepening this
system as it tracks east as a positively tilted system. The main
piece of energy is still expected to lift northeast and through the
Central Plains Saturday night and Sunday. Very strong mid/upper
level dynamics will result in large pressure falls downstream and a
deepening surface cyclone. While the wind shear parameters will be
quite strong and supportive of severe weather the key to it forming
will be the quality of low level moisture return. It currently
appears the low level moisture will be lacking by the time the
associated pre-frontal convergence zone reaches the CWA Sunday
morning. Thus the lack of sufficient instability will be a deterrent
to severe storm formation. However, the strength of the 0-6km bulk
shear will be supportive of fast moving storms which could produce
strong winds. In addition, the shear may be so strong as to shear
away the tops of any storms and thus destroy the vertical
structure/updraft.
Best bet for showers and thunderstorms will be Saturday night and
Sunday morning.
MJ
Medium Range (Monday through Friday)...
Expect mainly dry conditions with a bit of a roller coaster ride for
temperatures during the work week next week. By Monday, the system
that brings showers and thunderstorms to the forecast area Saturday
night into Sunday, will shift northeastward into the Great Lakes.
With no real cold air behind the cold front that moves through the
area Sunday, temperatures on Monday will hover near average in the
upper 30s to mid 40s. On Tuesday an upper level trough will move
through the area. Precipitation associated with this system will
remain south of the area but it will knock highs down a few degrees.
Height rises from weak upper level ridging building into the area
and downsloping westerly flow will help temperatures move above
average Wednesday. Highs will be in the 40s. Temperatures will climb
further on Thursday out ahead of the next storm system. There will
be a return to southwesterly flow allowing temperatures to rise into
the mid 40s to lower 50s. A cold front will move through the area
Thursday night however models are not in agreement on precipitation.
The GFS brings snow to the entire CWA behind the front while the EC
digs an upper level trough, associated with the aforementioned cold
front, further south with rain or snow affecting the southern CWA.
Have maintained the slight chance pops the initialization painted
across the southern CWA for Friday. One certainty is temperatures
will be cooler on Friday with strong cold air advection keeping
highs in the 30s across the CWA.
73
&&
.AVIATION...
For the 12z TAF...Concerns growing that the extensive MVFR stratus
field will be slower to break up/dissipate. RAP only model which
effectively handles the current stratus. Latest RAP Bufkit progged
soundings and AvnFPS climatology suggest MVFR cigs could linger
through this afternoon. However, inspection of last nights 00z OAX
sounding revealed a very thin cloud layer so will split the
difference with the RAP and scatter out the cigs by mid afternoon.
Once these cigs are gone expect VFR conditions with east to
southeast winds.
MJ
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
552 AM CST FRI FEB 8 2013
.SHORT TERM...
ISSUED AT 221 AM CST FRI FEB 8 2013
(TODAY)
SFC HIGH WILL CONTINUE TO BUILD INTO THE REGION THROUGH THE DAY. MAX
TEMPS ARE THE FCST CHALLENGE TODAY. NEW MODEL GUIDANCE INDICATES
STRATUS WILL STICK AROUND LONGER THAN PREVIOUSLY ANTICIPATED...WITH
CLOUDY/MOSTLY CLOUDY CONDITIONS LASTING INTO THE AFTN. THEREFORE
HIGH TEMPS HAVE BEEN LOWERED BY ABOUT 5 DEGREES ACROSS THE
BOARD...DEPENDING ON WHAT THE CLOUDS ACTUALLY DO...THAT MAY OR
MAY NOT BE A SMART MOVE. IF THE CLOUDS BREAK UP PRIOR TO
NOON...THEN HIGHS ARE NOW PROBABLY TOO COOL...BUT IF THEY HANG
TOUGH THROUGH THE AFTN...THEN I/M PROBABLY STILL TOO WARM. AREA
SHOULD REMAIN IN CAA THROUGH THE DAY WITH THE SFC RIDGE AXIS NOT
CROSSING THE CWA UNTIL THIS EVENING. LOCAL CLIMO SUGGESTS THAT
TEMPS SHOULD REMAIN NEARLY STEADY TODAY. IN THIS INSTANCE...THAT
SEEMS A BIT AGGRESSIVE AS 850 AND 925 TEMPS ACTUALLY RISE DURING
THE AFTN.
2%
&&
.LONG TERM...
ISSUED AT 330 AM CST FRI FEB 8 2013
(TONIGHT THROUGH THURSDAY)
SURFACE RIDGE TO MOVE OFF TO THE EAST TONIGHT ALLOWING SOUTHEASTERLY
WINDS TO RETURN TO THE AREA. HOWEVER...WITH CLEAR SKIES AND LIGHT
SOUTHEAST WINDS...TEMPERATURES WILL BE COOLER THAN THIS MORNINGS
TEMPS...IN THE MID TO UPPER 20S.
BY SATURDAY...DESPITE HIGH CLOUDS MOVING IN AHEAD OF NEXT WEATHER
SYSTEM...INCREASING SOUTH WINDS AND DECENT MIXING WILL ALLOW TEMPS
TO WARM UP INTO THE UPPER 40S TO LOW 50S...ABOUT 5 TO 10 DEGREES
ABOVE NORMAL FOR THIS TIME OF YEAR.
AS WARM FRONT ASSOCIATED WITH NEXT WEATHER SYSTEM LIFTS NORTHWARD
THROUGH AREA SATURDAY NIGHT...WILL SEE ELEVATED CONVECTION DEVELOP
AND SPREAD NORTHEASTWARD ACROSS FORECAST AREA. NOT A LOT OF
INSTABILITY...SO JUST HAVE SILENT SLIGHT CHANCE MENTION OF
THUNDERSTORMS IN WEATHER GRIDS FOR NOW. LOWS SATURDAY NIGHT WILL BE
IN THE MID 30S TO LOW 40S.
WILL HAVE BETTER CHANCES OF THUNDERSTORMS ON SUNDAY WITH MAIN COLD
FRONT AS IT SLIDES QUICKLY EAST THROUGH FORECAST AREA. DESPITE
DECENT SHEAR/HELICITY AND DEWPTS IN THE MID TO UPPER 40S...NO SEVERE
WEATHER EXPECTED AT THIS TIME AS BEST INSTABILITIES AND MOISTURE
RETURN WILL BE FURTHER SOUTH OVER THE LOWER MISSISSIPPI VALLEY.
HIGHS WILL BE IN THE LOW 50S TO LOW 60S.
PCPN TO SHUT OFF PRETTY QUICK SUNDAY EVENING WITH COLDER AIR
FILTERING IN...BUT REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR...IN
THE 30S.
BEYOND THAT...KEPT EXTENDED DRY FOR NOW AS MODELS KEEP NEXT
SIGNIFICANT SHORTWAVE FURTHER TO THE SOUTH...THUS PCPN ASSOCIATED
WITH IT REMAINS TO THE SOUTH OF FORECAST AREA MID WEEK.
OTHERWISE...COLDER AIR TO FILTER IN BY TUESDAY WITH HIGHS DIPPING
INTO THE MID 30S TO MID 40S...THEN MODERATE BY THE END OF THE
FORECAST PERIOD AS SURFACE RIDGE BECOMES ANCHORED OVER LOWER
MISSISSIPPI RIVER VALLEY. HIGHS BY THURSDAY WILL BE BACK IN THE
UPPER 40S TO LOW 50S.
BYRD
&&
.AVIATION...
ISSUED AT 528 AM CST FRI FEB 8 2013
A SFC RIDGE IS EXPECTED TO BUILD INTO THE REGION THROUGH THE DAY.
THE SFC RIDGE SLIDES EAST THIS EVENING PUTTING THE AREA IN SE
RETURN FLOW BY SATURDAY MORNING. IFR CIGS HAVE SLOWLY RAISED ALL
NIGHT WITH CIGS AT MOST LOCATIONS AOA 1KFT. THE MAIN FCST
CHALLENGE WILL BE DETERMINING WHEN AND IF THE STRATUS WILL
DISSIPATE. MOST MODEL GUIDANCE HAS THE STRATUS BREAKING UP LATE
MORNING INTO THE AFTN. I THINK THIS MAY BE TOO OPTIMISTIC. GIVEN
THE AMOUNT OF STRATUS ALREADY IN PLACE AND THE FACT THAT THE WINDS
ARE EXPECTED TO BECOME NERLY LATER TODAY IS NOT A CLIMATOLOGICALLY
FAVORABLE SET UP FOR THE DISSIPATION OF STRATUS. THIS SCENARIO IS
SUPPORTED BY THE RUC MODEL. CIG DISSIPATION WAS PUSHED BACK WITH
THIS PACKAGE...BUT THE TIMING MAY NEED TO BE PUSHED BACK EVEN
FURTHER WITH SUBSEQUENT FCST ISSUANCES.
SPECIFICS FOR KSTL...
MVFR CIG SHOULD SCATTER OUT THIS AFTN...THOUGH THIS TIMING MAY BE
TOO OPTIMISTIC. WINDS WILL VEER FROM NORTH TO SE AS SFC HIGH SLIDES
EAST THIS EVENING.
2%
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
546 AM CST FRI FEB 8 2013
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Short Range (Today through Sunday)...
The weather will become progressively more interesting Saturday
night and Sunday. Until then the main concern will be how soon
before the stratus departs. A large area of stratus has expanded
south-southwest under a surface ridge which extends from MN through
eastern KS and northwest TX. Except for the RAP the models are doing
a poor job handling this cloud cover. Part of that is due to a lack
of depth to the cloud cover. Latest RAP soundings via Bufkit and
AvnFPS climatology suggest the stratus could very well hang around
into the afternoon hours...especially east of the surface ridge. For
now,
will side on a rapid break up this afternoon but will pass along
concerns to the day shift. Should cloudy skies linger through the
afternoon the current high temperatures will prove to be too
optimistic.
Primary attention will then focus on the deep upper trough now
moving through CA. Models are in good agreement in deepening this
system as it tracks east as a positively tilted system. The main
piece of energy is still expected to lift northeast and through the
Central Plains Saturday night and Sunday. Very strong mid/upper
level dynamics will result in large pressure falls downstream and a
deepening surface cyclone. While the wind shear parameters will be
quite strong and supportive of severe weather the key to it forming
will be the quality of low level moisture return. It currently
appears the low level moisture will be lacking by the time the
associated pre-frontal convergence zone reaches the CWA Sunday
morning. Thus the lack of sufficient instability will be a deterrent
to severe storm formation. However, the strength of the 0-6km bulk
shear will be supportive of fast moving storms which could produce
strong winds. In addition, the shear may be so strong as to shear
away the tops of any storms and thus destroy the vertical
structure/updraft.
Best bet for showers and thunderstorms will be Saturday night and
Sunday morning.
MJ
Medium Range (Monday through Friday)...
Expect mainly dry conditions with a bit of a roller coaster ride for
temperatures during the work week next week. By Monday, the system
that brings showers and thunderstorms to the forecast area Saturday
night into Sunday, will shift northeastward into the Great Lakes.
With no real cold air behind the cold front that moves through the
area Sunday, temperatures on Monday will hover near average in the
upper 30s to mid 40s. On Tuesday an upper level trough will move
through the area. Precipitation associated with this system will
remain south of the area but it will knock highs down a few degrees.
Height rises from weak upper level ridging building into the area
and downsloping westerly flow will help temperatures move above
average Wednesday. Highs will be in the 40s. Temperatures will climb
further on Thursday out ahead of the next storm system. There will
be a return to southwesterly flow allowing temperatures to rise into
the mid 40s to lower 50s. A cold front will move through the area
Thursday night however models are not in agreement on precipitation.
The GFS brings snow to the entire CWA behind the front while the EC
digs an upper level trough, associated with the aforementioned cold
front, further south with rain or snow affecting the southern CWA.
Have maintained the slight chance pops the initialization painted
across the southern CWA for Friday. One certainty is temperatures
will be cooler on Friday with strong cold air advection keeping
highs in the 30s across the CWA.
73
&&
.AVIATION...
For the 12z TAF...Concerns growing that the extensive MVFR stratus
field will be slower to break up/dissipate. RAP only model which
effectively handles the current stratus. Latest RAP Bufkit progged
soundings and AvnFPS climatology suggest MVFR cigs could linger
through this afternoon. However, inspection of last nights 00z OAX
sounding revealed a very thin cloud layer so will split the
difference with the RAP and scatter out the cigs by mid afternoon.
Once these cigs are gone expect VFR conditions with east to
southeast winds.
MJ
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
434 AM CST FRI FEB 8 2013
.DISCUSSION...
Short Range (Today through Sunday)...
The weather will become progressively more interesting Saturday
night and Sunday. Until then the main concern will be how soon
before the stratus departs. A large area of stratus has expanded
south-southwest under a surface ridge which extends from MN through
eastern KS and northwest TX. Except for the RAP the models are doing
a poor job handling this cloud cover. Part of that is due to a lack
of depth to the cloud cover. Latest RAP soundings via Bufkit and
AvnFPS climatology suggest the stratus could very well hang around
into the afternoon hours...especially east of the surface ridge. For
now,
will side on a rapid break up this afternoon but will pass along
concerns to the day shift. Should cloudy skies linger through the
afternoon the current high temperatures will prove to be too
optimistic.
Primary attention will then focus on the deep upper trough now
moving through CA. Models are in good agreement in deepening this
system as it tracks east as a positively tilted system. The main
piece of energy is still expected to lift northeast and through the
Central Plains Saturday night and Sunday. Very strong mid/upper
level dynamics will result in large pressure falls downstream and a
deepening surface cyclone. While the wind shear parameters will be
quite strong and supportive of severe weather the key to it forming
will be the quality of low level moisture return. It currently
appears the low level moisture will be lacking by the time the
associated pre-frontal convergence zone reaches the CWA Sunday
morning. Thus the lack of sufficient instability will be a deterrent
to severe storm formation. However, the strength of the 0-6km bulk
shear will be supportive of fast moving storms which could produce
strong winds. In addition, the shear may be so strong as to shear
away the tops of any storms and thus destroy the vertical
structure/updraft.
Best bet for showers and thunderstorms will be Saturday night and
Sunday morning.
MJ
Medium Range (Monday through Friday)...
Expect mainly dry conditions with a bit of a roller coaster ride for
temperatures during the work week next week. By Monday, the system
that brings showers and thunderstorms to the forecast area Saturday
night into Sunday, will shift northeastward into the Great Lakes.
With no real cold air behind the cold front that moves through the
area Sunday, temperatures on Monday will hover near average in the
upper 30s to mid 40s. On Tuesday an upper level trough will move
through the area. Precipitation associated with this system will
remain south of the area but it will knock highs down a few degrees.
Height rises from weak upper level ridging building into the area
and downsloping westerly flow will help temperatures move above
average Wednesday. Highs will be in the 40s. Temperatures will climb
further on Thursday out ahead of the next storm system. There will
be a return to southwesterly flow allowing temperatures to rise into
the mid 40s to lower 50s. A cold front will move through the area
Thursday night however models are not in agreement on precipitation.
The GFS brings snow to the entire CWA behind the front while the EC
digs an upper level trough, associated with the aforementioned cold
front, further south with rain or snow affecting the southern CWA.
Have maintained the slight chance pops the initialization painted
across the southern CWA for Friday. One certainty is temperatures
will be cooler on Friday with strong cold air advection keeping
highs in the 30s across the CWA.
73
&&
.AVIATION...
Biggest change to forecast is to keep MVFR conditions prevailing
through 16Z as opposed to IFR conditions. Ceilings and visibilities
upstream remain MVFR as well, and outside of a temporary period of
IFR between 09-13Z, expect primarily MVFR conditions to prevail at
TAF sites. Stratus will mix out by late morning, returning VFR
conditions.
Blair
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1133 PM CST THU FEB 7 2013
.UPDATE...
.DISCUSSION...
FOG HAS DEVELOPED OVER THE STRATUS FIELD ACROSS KANW-KONL. AS THE
SOUTHERLY LOW LEVEL JET DEVELOPS TONIGHT AND VEERS SOUTHWESTERLY
TOWARD MORNING...THIS FOG SHOULD LIFT AND THE CIGS SHOULD ERODE.
&&
.AVIATION...
MVFR/IFR/LIFR ACROSS KANW-KONL PERSISTS TONIGHT AND THEN LIFTS
NORTHEAST FRIDAY MORNING. VFR IS EXPECTED ALL AREAS THEREAFTER.
WINDS FRIDAY AFTERNOON INCREASE TO 18022G32KT.
&&
.PREV DISCUSSION... /ISSUED 821 PM CST THU FEB 7 2013/
UPDATE...
DISCUSSION...
RAISED MIN TEMPS A BIT IN THE WEST AND CNTL OVERNIGHT AS SOUTH
WINDS ARE FORECAST TO INCREASE FROM MIDNIGHT ONWARD. ALSO
INCREASED CLOUDS ACROSS THE EAST AS THE RUC AND SATELLITE SHOW
THIS BANK ADVANCING WEST TO NEAR HWY 83 BY MORNING AND THEN
RETREATING BACK EAST BY NOON FRIDAY. THE REST OF THE FCST IS ON
TRACK.
PREV DISCUSSION... /ISSUED 733 PM CST THU FEB 7 2013/
UPDATE...
AVIATION...
A BIT OF A SNAFU HAS DEVELOPED ACROSS NERN NEB. WHILE THE OTHER
MODELS LIFT THE STRATUS NORTHEAST TONIGHT...THE RUC DROPS IT IN
ALONG AND EAST OF HIGHWAY 83. THE LATEST SATELLITE LOOPS INDICATES
THE RUC IS VERIFYING. SO A NEW TAF IS IN PLACE FOR KVTN.
PRESUMABLY...THE STRATUS SHOULD REVERSE AND MOVE BACK EAST FRIDAY MORNING TO
AROUND KBBW-KONL BY AROUND 17Z.
PREV DISCUSSION... /ISSUED 516 PM CST THU FEB 7 2013/
UPDATE...
AVIATION...
VFR IS EXPECTED ALL AREAS TONIGHT AND FRIDAY.
THE BANK OF STRATUS ACROSS NORTHEAST NEB THIS AFTN WILL LIFT
NORTHEAST THIS EVENING AS LOW PRESSURE DEVELOPS ACROSS THE NRN
HIGH PLAINS. SCATTERED HIGH LEVEL CLOUDINESS IS EXPECTED
THEREAFTER. WINDS SATURDAY INCREASE TO 18O22G32KT AS THE LOW
PRESSURE DROPS SOUTH AND DEEPENS ACROSS THE CNTL HIGH PLAINS.
PREV DISCUSSION... /ISSUED 328 PM CST THU FEB 7 2013/
SHORT TERM...(THIS EVENING THROUGH FRIDAY)
AN ARCTIC COLD FRONT HAS BECOME NEARLY STATIONARY ACROSS EASTERN
PORTIONS OF NORTH CENTRAL NEBRASKA LATE THIS AFTERNOON...WITH AN
AREA OF LOW CLOUDS/STRATUS LINGERING ACROSS WHEELER...HOLT...AND
BOYD COUNTIES. THIS FRONT SHOULD MOVE EAST AS A WARM FRONT
TONIGHT...AS SOUTHERLY WINDS DEVELOP IN RESPONSE TO THE APPROACHING
STORM SYSTEM FROM THE WEST. A BREEZY TO WINDY DAY IS EXPECTED
FRIDAY AS THE PRESSURE GRADIENT CONTINUES TO TIGHTEN. SOUTH WINDS
LOOK TO STAY JUST UNDER WIND ADVISORY THRESHOLDS AT THIS
TIME...BUT WILL CONTINUE TO MONITOR. OTHERWISE A MILD DAY
FRIDAY...WITH HIGHS IN THE UPPER 40S TO MID 50S.
LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
MAIN FORECASTING CHALLENGE IS PRECIPITATION POTENTIAL WITH AN
APPROACHING WINTER STORM SATURDAY THROUGH SUNDAY NIGHT. THE MID
RANGE MODEL SOLUTIONS CONTINUE TO HAVE DIFFICULTY IN RESOLVING THE
TRACK AND SPEED OF A CLOSED UPPER LEVEL LOW AND ASSOCIATED
SNOWFALL LATER THIS WEEKEND. THE 12Z NAM AND 12Z GFS SOLUTIONS
TRENDED FURTHER NORTH THIS MORNING WITH THE H5 AND H7 LOWS. THE
GFS SOLN TRACKS THE H5 LOW FROM FAR NERN COLORADO...ALONG A LINE
FROM OGALLALA...TO NORTH PLATTE...TO BROKEN BOW...AND NORTHEAST OF
ONEILL. THE NAM SOLUTION IS FURTHER NORTH YET...TRACKING THE LOW
FROM NORTH OF SIDNEY...TO AINSWORTH TO NORTH OF ONEILL. THE LATEST
ECMWF TRENDED THE UPPER LOW FURTHER SOUTH FROM AROUND GOODLAND
KS...TO SOUTH OF KEARNEY...TO NORFOLK. GIVEN THE LARGE SPREAD IN
SOLUTIONS...DECIDED ON A COMPROMISE...AND MORE TOWARD THE GFS/EC
SOLUTION...WHICH FAVORS THE HEAVIEST SNOW...NORTH OF A LINE FROM
OGALLALA...TO STAPLETON TO ONEILL. IN THESE AREAS...DECIDED TO
HOIST A WINTER STORM WATCH FOR SNOWFALL POTENTIAL IN EXCESS OF 6
INCHES. AM EXPECTING STRONG GUSTY WINDS AND DECENT BLOWING SNOW
POTENTIAL ON SUNDAY BEHIND THE EXITING SYSTEM AS H85 WINDS REACH
50+ KTS OVER NORTHERN NEBRASKA. THIS WILL NO DOUBT PRODUCE SOME
VERY HAZARDOUS TRAVEL CONDITIONS SUNDAY AND SUNDAY EVENING.
IN ADVANCE OF THIS APPROACHING SYSTEM...STRONG SOUTHERLY WINDS WILL
CONTINUE FRIDAY NIGHT...WHICH WILL ALLOW MOISTURE TO WORK NORTH INTO
SOUTHWESTERN...CENTRAL AND EASTERN NEBRASKA ON SATURDAY. AS A LEAD
DISTURBANCE PUSHES INTO WESTERN KANSAS SATURDAY AFTERNOON...SHOWERS
AND EVEN SOME THUNDERSTORMS SHOULD DEVELOP INVOF OF A DRYLINE OVER
WESTERN KANSAS. THIS ACTIVITY WILL TRACK NORTH INTO SOUTHWESTERN
NEBRASKA AS H5 WINDS ARE ORIENTED SOUTH TO NORTH. ACTIVITY IS
EXPECTED TO PERSIST INTO THE EVENING HOURS ACROSS SOUTHWESTERN AND
CENTRAL NEBRASKA WITH PLENTY OF ELEVATED INSTABILITY NOTED PER H85
LI`S. AT THIS TIME...NOT EXPECTING ANY SEVERE TSRAS...BUT GIVEN THE
LOW FREEZING LEVELS...WOULDN`T BE SURPRISED TO SEE SOME SMALL
HAIL...ESPECIALLY SATURDAY EVENING.
RAIN WILL CHANGEOVER TO SNOW FROM WEST TO EAST OVERNIGHT SATURDAY
NIGHT...AS THE UPPER LEVEL SYSTEM TRACKS INTO CENTRAL...THEN
NORTHEASTERN NEBRASKA. ATTM...BASED ON THE GFS TRACK...A NICE
DEFORMATION ZONE DEVELOPS ACROSS SRN SD AND NORTHERN NEBRASKA LATE
SATURDAY NIGHT INTO SUNDAY. MODERATE TO HEAVY SNOW WILL DEVELOP
WITHIN THIS BAND...WHICH ATTM...IS NORTH OF A LINE FROM
OGALLALA...TO STAPLETON TO ONEILL. AS MENTIONED EARLIER...ONE CAVEAT
IS THE ECMWF SOLN...WHICH IS 100 MILES FURTHER SOUTH WITH ITS TRACK.
IF THIS WERE TO VERIFY...HEAVY SNOW WOULD EXTEND ALONG A LINE FROM
IMPERIAL...TO NORTH PLATTE TO BROKEN BOW. THIS WILL BE MONITORED
CLOSELY OVER THE NEXT 12 TO 24 HOURS AND ANY CHANGES TO THE ONGOING
HEADLINES AND FORECASTS WILL BE MADE OVERNIGHT TONIGHT OR FRIDAY
AFTERNOON.
BEYOND MONDAY...NORTHWESTERLY FLOW ALOFT...WILL BRING DRY...BUT COLD
CONDITIONS TO WESTERN AND NORTH CENTRAL NEBRASKA. WITH EXPECTED SNOW
COVER IN PLACE...TRENDED TEMPS BELOW THE LATEST MEX AND ECE
GUIDANCE.
AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
AN AREA OF LIFR STRATUS/FOG WILL LINGER INTO THEAFTERNOON HOURS
NORTHEAST OF A KBUB TO KANW LINE. THIS IS DUE TO AN ARCTIC FRONT
THAT HAS BACK SOUTHWEST INTO THE AREA. THIS SHOULD STAY EAST OF
THE KVTN TAF SITE...AND VFR CONDITIONS SHOULD PREVAIL THROUGH
TONIGHT AT BOTH KVTN AND KLBF. NORTHWEST SFC WINDS AROUND 10 KTS
THIS AFTERNOON...WILL BECOME SOUTHEAST 5 TO 10 KTS TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
FOR NEZ004>010-022>027-035>037-056-057-094.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION....CDC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
528 PM EST FRI FEB 8 2013
.SYNOPSIS...
WINTER STORM WILL CONTINUE TO AFFECT THE NORTH COUNTRY THROUGH
SATURDAY MORNING. HIGH PRESSURE SLOWLY BUILDS OVER THE AFTERNOON AND
EVENING HOURS AND THEN REMAINS OVER THE REGION FOR THE REMAINDER OF
THE WEEKEND. ANOTHER WEATHER SYSTEM AFFECTS THE NORTH COUNTRY NEXT
MONDAY INTO WEDNESDAY...FOLLOWED BY HIGH PRESSURE FOR WEDNESDAY
NIGHT INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 528 PM EST FRIDAY...SFC CYCLONE UNDERGOING RAPID DEEPENING
NEAR THE 40N/70W BENCHMARK. RAP ANALYSES SHOW A ZONE OF DEVELOPING
700 MB FRONTOGENESIS EXTENDING ACROSS CENTRAL VERMONT INTO THE
NORTHERN ADIRONDACKS. BELIEVE THIS AS WELL AS SOME CONVERGENCE IN
THE CHAMPLAIN VALLEY WILL HELP TO FOCUS BANDS OF MODERATE TO
LOCALLY HEAVY SNOW ACROSS CENTRAL VERMONT...THE CHAMPLAIN VALLEY
AND THE NORTHERN ADIRONDACKS AS THE EVENING PROGRESSES. COMPOSITE
RADAR IS ALREADY BEGINNING TO BEAR THIS OUT WITH BANDED 25 TO 30
DBZ ECHOES. EXPECT THESE TRENDS TO CONTINUE THROUGH AT LEAST THE
EARLY OVERNIGHT HOURS. HAVE UPDATED THE WINTER STORM WARNING TEXT
TO REFLECT THE TIMING OF THESE BANDS. GUSTY NORTHWEST WINDS WILL
LEND ITSELF TO AREAS OF BLOWING AND DRIFTING SNOW.
OTHERWISE...HAVE MADE NO OTHER CHANGES TO THE CURRENT FORECAST
EXCEPT TO BLEND IN CURRENT OBSERVATIONAL DATA.
PREVIOUS DISCUSSION ISSUED AT 330 PM EST FRIDAY...
WINTER STORM CONTINUES TO AFFECT THE CWA THIS AFTNOON...WITH
VARYING AMTS ACROSS THE AREA THUS FAR. HIGHEST TOTALS ATTM ARE
ACROSS THE NORTHERN CVLY INTO N NY. LESSER AMTS OVER SOUTHERN
ZONES DUE TO AREA BEING BETWEEN THE TWO SFC LOWS THRU THE DAY.
INLAND LOW IS EXPECTED TO BREAK DOWN OVERNGT...TRANSFERRING ENERGY
TO OFFSHORE LOW. MUCH OF SNOW OCCURRING NOW WILL SHIFT TO E VT
OVERNGT TOWARDS SATURDAY MORNING. DESPITE LACK OF ACCUM SNOWS FOR
SC VT...THESE AREAS WILL MAKE UP FOR IT OVERNGT. HAVE ADJUSTED
AMTS THRU THE OVERNGT FOR STORM TOTALS. ADJUSTED NUMBERS DOWNWARD
BY SEVERAL INCHES FOR PORTIONS OF ADDISON/RUTLAND COUNTIES DUE TO
DOWNSLOPING/SHADOWING EFFECTS. HIGHEST AMTS FOR CWA WILL CONTINUE
TO LEAN TOWARDS DACKS/SLV AND SE VT...ESPECIALLY IN HIR ELEV OF
WINDSOR COUNTY. OVERALL 8-16 INCHES STORM ACCUM WITH LCL AMTS HIR
NEAR 20 INCHES IN AFOREMENTIONED AREAS. WINDS ON THE INCR AS WELL
WITH GRADIENT SHIFTING WITH COASTL LOW MVG TOWARDS CAPE COD. TIGHT
GRADIENT WILL SUPPORT GUST POTENTIAL 30-40 MPH.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 330 PM EST FRIDAY...BY SATURDAY MORNING...EXPECTING WINTER
STORM TO WORKING EAST OF NEW ENGLAND...PUTTING FOCUS OF REMAINING
SNOW SHOWERS OVER EASTERN VT BFR TAPERING OFF BY MIDDAY/EARLY
AFTERNOON. SHARP CUTOFF AS RIDGE BUILDS SOUTH AND EAST INTO THE
REGION. LOOKING FOR AN ADDITIONAL INCH OR TWO ACCUM FOR SAT
MORNING...W/ FOCUS IN THE CT RIVER VALLEY. SOME LGT NON-ACCUM -SW
FOR WESTERN SLOPES/CVLY FOR SAT MORNING. STRONG WINDS WILL ALSO
TAPER OFF FROM W TO E AS RIDGE INTO AREA. CLRING SKIES COMBINED
WITH FRESH SNOW COVER FOR SAT NGT HAS TEMPS DROPPING ACROSS THE
CWA. MDL GUIDANCE IS MIXED FOR OVERNGT LOWS. MAV GUIDANCE TOO CD
OVER PAST WEEK OR SO WILL BE MVG CLOSER TO MET GUIDANCE WHICH PUTS
VALLEY LOCALES IN SINGLE NUMBERS ABV ZERO AND NEGATIVE NUMBERS FOR
HIR ELEV. NICE CD DAY ON TAP FOR SUNDAY AS RIDGE CRESTS OVER THE
NORTHEAST. GOING BLW NORMAL NUMBERS FOR HIGHS SUNDAY DESPITE FULL
SUNSHINE. LOOKING FOR HIGHS IN TEENS FOR VALLEY LOCALES AND NEAR
10F FOR HIR ELEV. GOING INTO SUN NGT...RIDGE BEGINS TO SLIDE EAST
OFFSHORE...ALLOWING FOR WAA TO BUILD INTO THE ST LAW VALLEY AND
EVENTUALLY THE CVLY OVERNGT SUNDAY. THIS WILL CAP LOWS IN THESE
AREAS...ALSO AIDED BY INCR CLDS FOR N NY AS FRNTL BOUNDARY LIFTS
NE. SL CHANCE BY MON MORNING FOR -SW FOR N NY...MAINLY FOR AREAS
NEAR LK ONTARIO.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 337 PM EST FRIDAY...THE 12Z GFS AND 12Z ECMWF SHOW GOOD
CONSISTENCY IN BRINGING A SHORTWAVE TROUGH AND ASSOCIATED SFC
EASTWARD ACROSS THE GREAT LAKES MONDAY AFTN...WITH THE SFC LOW
TRACKING NORTH OF THE INTL BORDER DURING SUNDAY NIGHT. ASSOCIATED
PERIOD OF LOW- LEVEL WAA/QG FORCING IS EXPECTED TO BRING SOME
LIGHT TO MODERATE PRECIPITATION (QPF UP TO 0.25") DURING MONDAY
AFTN INTO THE FIRST PART OF MONDAY NIGHT. VERTICAL TEMPERATURE
PROFILE BECOMES MARGINAL FOR SNOW WITH 850MB 0C LINE LIFTING NORTH
OF THE INTL BORDER IN ADVANCE OF SFC LOW FOR A TIME MONDAY AFTN. OUR
TOP-DOWN APPROACH FOR P-TYPE YIELDS A MIX OF SNOW/SLEET AND A BIT
OF RAIN FOR THE CHAMPLAIN AND S-CENTRAL VT VALLEYS. COULD BE SOME
MINOR TRAVEL IMPACTS - ESPECIALLY FOR HIGHER ELEVATIONS DURING
MONDAY AFTN AND MONDAY NIGHT...AND HAVE INDICATED POPS IN THE
LIKELY CATEGORY (60-70 PERCENT). HIGH TEMPS ON MONDAY WILL
GENERALLY BE IN THE 30S.
AS SHORTWAVE TROUGH SHIFTS EAST OF THE AREA ON TUESDAY...WINDS
BECOME MODERATE NWLY 15-25 MPH WITH POTENTIAL FOR SNOW SHOWER
ACTIVITY...ESPECIALLY IN FAVORED UPSLOPE AREAS INCLUDING THE NRN
ADIRONDACKS AND NRN GREEN MTNS. THIS NWLY FLOW GRADUALLY WEAKENS BY
TUESDAY NIGHT...SETTING UP FAIR AND TRANQUIL CONDITIONS FOR
WEDNESDAY. HIGHS TUESDAY WILL BE IN THE 30S...BUT THEN IN THE
MID-UPR 20S FOR WEDNESDAY.
MODEL SOLUTIONS DIVERGE THU-FRI...BUT WITH GENERAL TENDENCY IN SOLNS
FOR DEEPENING MID-LEVEL TROUGH ACROSS THE WRN GREAT LAKES AND ACROSS
THE NORTH-CENTRAL CONUS. THIS WOULD MEAN TEMPS SOMEWHAT ABOVE
AVERAGE FOR THE NORTH COUNTRY. POPS AT THIS POINT ARE LOW...WITH
FRONTAL SYSTEM EXPECTED TO BE DEVELOPING ACROSS THE GREAT LAKES AND
OHIO VALLEY REGION THURSDAY NIGHT INTO FRIDAY. HIGH TEMPS GENERALLY
IN THE 30S ACROSS THE NORTH COUNTRY BOTH DAYS.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 18Z SATURDAY...SIGNIFICANT IMPACT TO AVIATION AND GROUND-
BASED OPERATIONS OWING TO MODERATE TO OCCASIONALLY HEAVY SNOW AT
THE TAF LOCATIONS THROUGH THE REMAINDER OF TODAY UNTIL THE PRE-
DAWN HOURS SATURDAY. FRONTAL BOUNDARY ACROSS THE AREA BRINGING
STEADY IFR CONDITIONS WITH SNOW AND VSBY GENERALLY BELOW 1 MILE.
SNOW IS STEADIEST ACROSS NORTHERN AREAS...WITH LIGHTER SNOW AT
RUT. AS COASTAL LOW DEEPENS OFF DELMARVA AND MOVES SE OF CAPE COD
TONIGHT...ANTICIPATE KRUT BECOMING IFR IN SNOW AFTER 21Z. LOW
PULLS EAST OF CAPE COD TOMORROW MORNING WITH WINDS BECOMING N-NW
AT 10-15 KTS WITH GUSTS UP TO 25 KTS. MAY SEE A FEW GUSTS TO 30
KTS TOWARD 18Z SATURDAY. SNOW GENERALLY ENDS BY 12Z SATURDAY WITH
VSBY BECOMING P6SM AND CEILINGS RISING TO 2000-3500 FT BY 15Z SAT.
OUTLOOK 18Z SATURDAY THROUGH WEDNESDAY...STORM SYSTEM CLEARS OUT
OF THE REGION WITH HIGH PRESSURE BUILDING IN FROM THE GREAT LAKES
REGION ACROSS THE NORTH COUNTRY SAT NIGHT AND SUNDAY. THIS HIGH
PRESSURE SYSTEM WILL BRING DIMINISHING WINDS SATURDAY NIGHT AND
GENERALLY VFR CONDITIONS. WINDS SHIFT INTO THE SOUTH BY MONDAY
MORNING AS RIDGE AXIS SHIFTS EAST OF NEW ENGLAND. NEXT FRONTAL
SYSTEM BRINGS A PERIOD OF MIXED WINTRY PCPN AND MVFR/OCCASIONAL
IFR CONDITIONS MONDAY AFTN INTO MONDAY NIGHT. GENERALLY VFR
TUESDAY AND WEDNESDAY...HOWEVER LIGHT SNOW SHOWERS MAY LINGER AT
MPV/SLK WITH NW LOW-LEVEL FLOW IN PLACE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WARNING UNTIL 1 PM EST SATURDAY FOR VTZ001-002-
005-006-008>012-016>019.
WINTER WEATHER ADVISORY UNTIL 1 PM EST SATURDAY FOR VTZ003-004-
007.
NY...WINTER STORM WARNING UNTIL 1 PM EST SATURDAY FOR NYZ026>031-
034-035-087.
&&
$$
SYNOPSIS...JN
NEAR TERM...JN/LOCONTO
SHORT TERM...JN
LONG TERM...BANACOS
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
119 PM EST FRI FEB 8 2013
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL PASS ALONG LAKE ERIE AND INTO WESTERN
NEW YORK...SPREADING SNOW ACROSS THE REGION...WITH A WINTRY
MIX AND LOCALIZED RAIN SOUTH OF LAKE ONTARIO. THIS AREA OF LOW
PRESSURE WILL THEN MERGE WITH AN INTENSIFYING COASTAL LOW THAT WILL
BE MOVING NORTHWARD UP THE EAST COAST THIS AFTERNOON AND EVENING. AS
COLDER AIR PUSHES ACROSS THE REGION THIS AFTERNOON PRECIPITATION
WILL CHANGE TO ALL SNOW...WITH THE SNOW TAPERING OFF THROUGH THE
OVERNIGHT HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
SOME RECONFIGURATION TO THE WINTER WEATHER HEADLINE NEEDED THIS
MORNING. WARMER AIR FEEDING IN...ALONG WITH THE HELP OF DOWNSLOPE
FLOW HAS DIMINISHING THE THREAT OF FREEZING PRECIPITATION ALONG
THE SOUTHERN HALF OF THE AREA THIS MORNING...EVEN PLAIN RAIN ALONG
THE LAKE ERIE SHORELINE. RUC MODEL PROFILES SUGGESTING PRECIPITATION
WILL GO OVER QUICKLY TO SNOW LATE THIS MORNING. HOWEVER...WITH THE
LACK OF APPRECIABLE FREEZING PRECIPITATION THIS MORNING AND A
GENERAL 4-6 INCH ACCUMULATION THROUGH TONIGHT HAVE DOWNGRADED THE
WINTER STORM WARNING TO AN ADVISORY.
FARTHER TO THE NORTH...THE WINTER STORM WARNING WILL REMAIN IN
PLACE. UPPER TROUGH JUST UPSTREAM WILL PULL IN MUCH COLDER AIR THIS
AFTERNOON AS IT TAKES ON A NEGATIVE TILT. SNOWFALL RATES COULD
EXCEED AN INCH PER HOUR FOR A SEVERAL HOUR PERIOD THIS AFTERNOON
AS THE TROUGH CROSSES THE AREA.
SNOW WILL CONTINUE INTO THE EVENING HOURS WITH THE HEAVIEST SNOW
FOCUSED UPON THE SOUTH SHORE LAKE ONTARIO COUNTIES AS WELL AS THE
NORTH COUNTRY WHERE AN DEFORMATION BAND WILL FORM ON THE NORTHERN
SIDE OF THE UPPER LEVEL LOW. LIGHT SNOW WILL LIKELY LINGER THE
LONGEST SOUTH OF BUFFALO AND ROCHESTER WHERE A NORTHERLY UPSLOPE
WIND WILL MAINTAIN AT LEAST A CHANCE OF SNOW INTO THE LATE
OVERNIGHT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
STRONG LOW PRESSURE WILL EXIT FURTHER EAST OF CAPE COD AS HIGH
PRESSURE BUILDS IN FROM THE WEST ON SATURDAY. THERE WILL STILL BE A
MODEST NORTHERLY FLOW IN PLACE ACROSS THE REGION DURING THE DAY
SATURDAY. AS THE UPPER TROF ALSO EXITS TO THE EAST...MOISTURE WILL
DIMINISH THROUGH THE DAY...GETTING SHALLOWER AND LAKE INDUCED CAPE
DIMINISHES. 850MB TEMPERATURES ARE FORECAST TO BE AROUND
-12C...WHICH MAY BE ENOUGH TO GENERATE SOME VERY LIGHT LAKE EFFECT
SHOWERS. THIS IS ALSO MARGINALLY COLD ENOUGH FOR SNOW GROWTH...AND
TYPICALLY RESULTS IN FLURRIES OR SNIZZLE...EVEN THOUGH PATCHY
FREEZING DRIZZLE CANNOT BE RULED OUT. PRECIPITATION WILL PROBABLY BE
CONFINED TO UPSLOPE REGIONS IN CENTRAL PORTIONS OF THE CWA...WITH
ANY ACTIVITY TAPERING OFF IN THE AFTERNOON HOURS. TEMPERATURES WILL
BE ON THE COOL SIDE...WITH HIGHS IN THE LOWER 20S.
HIGH PRESSURE WILL RIDGE INTO THE REGION SATURDAY NIGHT...RESULTING
IN QUITE CHILLY OVERNIGHT LOWS. THE HIGH WILL BRING LIGHT WINDS AND
AND MOSTLY CLEAR SKIES WHICH IS GOOD FOR RADIATIONAL
COOLING...HOWEVER TEMPERATURES ALOFT WILL START TO WARM WHICH WILL
LIMIT LOWS A BIT. EXPECT LOW TEMPERATURES TO VARY WIDELY...WITH
SINGLE DIGITS COMMON IN MOST LOCATIONS...AND SUB-ZERO TEMPERATURES
EAST OF LAKE ONTARIO AND IN THE TYPICALLY COOLER VALLEYS. THE HIGH
WILL SLIDE TO THE EAST ON SUNDAY...PROVIDING A GOOD AMOUNT OF
SUNSHINE...AND WARMER TEMPERATURES. EXPECT LOCATIONS WEST OF
ROCHESTER TO RISE INTO THE 30S AND ABOVE FREEZING...WITH SLIGHTLY
COOLER TEMPERATURES TO THE EAST.
AS WE MOVE INTO SUNDAY NIGHT THE FOCUS SHIFTS TO THE NEXT SYSTEM
THAT WILL BE IMPACTING THE REGION. AN UPPER LEVEL LOW EJECTING OUT
OF THE DESERT SOUTHWEST WILL GENERATE A LEE CYCLONE OVER THE HIGH
PLAINS THAT WILL TRACK TO THE WESTERN GREAT LAKES BY SUNDAY NIGHT.
AS THIS LARGE STORM SYSTEM LIFTS NORTHEAST...THE TRIPLE POINT OF THE
LOW IS PROGGED TO ROTATE ACROSS WESTERN NEW YORK MONDAY MORNING WITH
WIDESPREAD PRECIP ACCOMPANYING THE FEATURE. THE AIR IN PLACE WILL
STILL BE FAIRLY COLD...AND WINDS AHEAD OF THE SYSTEM MAY NOT BE
STRONG ENOUGH TO DISPLACE THIS COLD AIR AT THE ONSET. GIVEN WARMING
DURING THE DAY ON SUNDAY...FEEL THAT AT LEAST ACROSS THE NIAGARA
FRONTIER AND NORTHERN GENESEE VALLEY TEMPERATURES WILL PROBABLY STAY
ABOVE FREEZING. COLDER AIR IN PLACE FARTHER EAST ACROSS THE FINGER
LAKES AND NORTH COUNTRY HOWEVER COULD PRESENT MORE OF A PROBLEM WITH
REGARDS TO FREEZING RAIN LATE SUNDAY NIGHT INTO MONDAY. A CONSENSUS
OF QPF AMONG THE GGEM/EUROPEAN/GFS BRINGS ABOUT QUARTER INCH. WARM
AIR WILL EVENTUALLY WIN OUT ON MONDAY...WITH TEMPERATURES EVENTUALLY
CLIMBING INTO THE 40S IN MOST LOCATIONS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
RAIN WILL EXIT EAST AS THE LOW TRACKS NORTH OF OUR REGION MONDAY
NIGHT AND COLDER AIR ONCE AGAIN FILTERS INTO THE REGION...THOUGH
GIVEN THAT THE LOW WILL BE DEEPLY OCCLUDED...AIRMASS ADVECTION
SHOULD NOT BE THAT COLD INITIALLY WITH 850MB TEMPS ONLY IN THE
NEIGHBORHOOD OF -6C TO -10C WITH TEMPS FALLING FROM THE 40S MONDAY
AFTERNOON INTO THE LOW TO MID 30S TUESDAY. GIVEN THE LACK OF DEEP
COLD AIR...NOT EXPECTING LAKE EFFECT SHOWERS WILL PRESENT MUCH OF A
PROBLEM. WEAK RIDGING BUILDS ACROSS THE OHIO VALLEY WEDNESDAY WITH
LIGHT WESTERLY FLOW AND MARGINALLY COLD TEMPERATURES BEING JUST
ENOUGH TO KEEP AT LEAST A LOW CHANCE OF LAKE EFFECT SHOWERS DOWNWIND
OF THE LAKES.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS SURFACE LOW PRESSURE AND ITS ASSOCIATED COLD FRONT MOVE FROM LAKE
ERIE TO MERGE WITH A LARGER COASTAL LOW...HEAVIER SNOW WILL MOVE
ACROSS THE REGION DURING THE AFTERNOON. THIS WILL RESULT IN A
SIGNIFICANT PERIOD OF VSBY BELOW 1SM...WITH PERIODS OF 1/4SM TO
1/2SM IN MODERATE TO HEAVY SNOW WITH CEILINGS OR VERTICAL VISIBILITY
AT OR BELOW 400 FEET. SNOW ACCUMULATIONS OF AN INCH AN HOUR ARE ALSO
LIKELY. A SECONDARY EPISODE OF LIGHTER SNOW WILL ACCOMPANY THE UPPER
LOW CROSSING THE AREA EARLY THIS EVENING.
CONDITIONS WILL IMPROVE FROM WEST TO EAST DURING THE EVENING. A
NORTHERLY FLOW OFF THE LAKES WILL CAUSE MVFR CIGS AND LIGHT SNOW
SHOWERS TO LINGER SOUTH OF THE LAKES LATE TONIGHT. HIGH PRESSURE
BUILDS IN ACROSS THE AREA FOR THE WEEKEND WITH VFR CONDITIONS.
OUTLOOK...
SATURDAY AND SUNDAY...VFR.
MONDAY...MVFR WITH RAIN AND POSSIBLE MIXED PCPN SPREADING EAST
ACROSS THE AREA.
TUESDAY...MVFR IN LIGHT SNOW.
WEDNESDAY...VFR WITH SLGT CHC OF SNOW.
&&
.MARINE...
AN AREA OF LOW PRESSURE OVER THE WESTERN END OF LAKE ERIE WILL
ADVANCE EASTWARD TOWARDS WESTERN NEW YORK BEFORE BECOMING ABSORBED
BY A DEEPENING AREA OF LOW PRESSURE ALONG THE EAST COASTLINE. THIS
WILL BRING A PERIOD OF GUSTY NORTHEAST WINDS BACKING TO NORTH...AND
THEN NORTHWEST THROUGH SATURDAY. SMALL CRAFTS CONDITIONS ON BOTH
LAKES TODAY AND TONIGHT BEFORE WINDS AND WAVES DROP BELOW SMALL
CRAFT LEVELS THROUGH THE NIGHT. ALSO A SMALL CRAFT WILL BE ISSUED
FOR THE LOWER NIAGARA RIVER WHERE NORTHERLY WINDS WILL FUNNEL UP THE
RIVER GORGE 15 TO 25 KNOTS. AN AREA OF HIGH PRESSURE WILL SETTLE
OVER THE LAKES SATURDAY AND SUNDAY WITH A PERIOD OF BELOW SMALL
CRAFT CONDITIONS LATER SATURDAY AND THROUGH MONDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER STORM WARNING UNTIL 5 AM EST SATURDAY FOR NYZ001>008-
010-011.
WINTER WEATHER ADVISORY UNTIL 5 AM EST SATURDAY FOR NYZ012>014-
019>021-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST SATURDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 4 AM EST SATURDAY FOR
LOZ030.
SMALL CRAFT ADVISORY UNTIL 6 PM EST SATURDAY FOR LOZ043.
SMALL CRAFT ADVISORY UNTIL 1 PM EST SATURDAY FOR LOZ042.
SMALL CRAFT ADVISORY UNTIL 8 AM EST SATURDAY FOR LOZ045.
SMALL CRAFT ADVISORY UNTIL 4 PM EST SATURDAY FOR LOZ044.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...THOMAS/TMA
SHORT TERM...APFFEL
LONG TERM...WOOD
AVIATION...WCH
MARINE...THOMAS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1034 AM EST FRI FEB 8 2013
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL PASS ALONG LAKE ERIE AND INTO WESTERN
NEW YORK...SPREADING SNOW ACROSS THE REGION...WITH A WINTRY
MIX AND LOCALIZED RAIN SOUTH OF LAKE ONTARIO. THIS AREA OF LOW
PRESSURE WILL THEN MERGE WITH AN INTENSIFYING COASTAL LOW THAT WILL
BE MOVING NORTHWARD UP THE EAST COAST THIS AFTERNOON AND EVENING. AS
COLDER AIR PUSHES ACROSS THE REGION THIS AFTERNOON PRECIPITATION
WILL CHANGE TO ALL SNOW...WITH THE SNOW TAPERING OFF THROUGH THE
OVERNIGHT HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
SOME RECONFIGURATION TO THE WINTER WEATHER HEADLINE NEEDED THIS
MORNING. WARMER AIR FEEDING IN...ALONG WITH THE HELP OF DOWNSLOPE
FLOW HAS DIMINISHING THE THREAT OF FREEZING PRECIPITATION ALONG
THE SOUTHERN HALF OF THE AREA THIS MORNING...EVEN PLAIN RAIN ALONG
THE LAKE ERIE SHORELINE. RUC MODEL PROFILES SUGGESTING PRECIPITATION
WILL GO OVER QUICKLY TO SNOW LATE THIS MORNING. HOWEVER...WITH THE
LACK OF APPRECIABLE FREEZING PRECIPITATION THIS MORNING AND A
GENERAL 4-6 INCH ACCUMULATION THROUGH TONIGHT HAVE DOWNGRADED THE
WINTER STORM WARNING TO AN ADVISORY.
FARTHER TO THE NORTH...THE WINTER STORM WARNING WILL REMAIN IN
PLACE. UPPER TROUGH JUST UPSTREAM WILL PULL IN MUCH COLDER AIR THIS
AFTERNOON AS IT TAKES ON A NEGATIVE TILT. SNOWFALL RATES COULD
EXCEED AN INCH PER HOUR FOR A SEVERAL HOUR PERIOD THIS AFTERNOON
AS THE TROUGH CROSSES THE AREA.
SNOW WILL CONTINUE INTO THE EVENING HOURS WITH THE HEAVIEST SNOW
FOCUSED UPON THE SOUTH SHORE LAKE ONTARIO COUNTIES AS WELL AS THE
NORTH COUNTRY WHERE AN DEFORMATION BAND WILL FORM ON THE NORTHERN
SIDE OF THE UPPER LEVEL LOW. LIGHT SNOW WILL LIKELY LINGER THE
LONGEST SOUTH OF BUFFALO AND ROCHESTER WHERE A NORTHERLY UPSLOPE
WIND WILL MAINTAIN AT LEAST A CHANCE OF SNOW INTO THE LATE
OVERNIGHT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
STRONG LOW PRESSURE WILL EXIT FURTHER EAST OF CAPE COD AS HIGH
PRESSURE BUILDS IN FROM THE WEST ON SATURDAY. THERE WILL STILL BE A
MODEST NORTHERLY FLOW IN PLACE ACROSS THE REGION DURING THE DAY
SATURDAY. AS THE UPPER TROF ALSO EXITS TO THE EAST...MOISTURE WILL
DIMINISH THROUGH THE DAY...GETTING SHALLOWER AND LAKE INDUCED CAPE
DIMINISHES. 850MB TEMPERATURES ARE FORECAST TO BE AROUND
-12C...WHICH MAY BE ENOUGH TO GENERATE SOME VERY LIGHT LAKE EFFECT
SHOWERS. THIS IS ALSO MARGINALLY COLD ENOUGH FOR SNOW GROWTH...AND
TYPICALLY RESULTS IN FLURRIES OR SNIZZLE...EVEN THOUGH PATCHY
FREEZING DRIZZLE CANNOT BE RULED OUT. PRECIPITATION WILL PROBABLY BE
CONFINED TO UPSLOPE REGIONS IN CENTRAL PORTIONS OF THE CWA...WITH
ANY ACTIVITY TAPERING OFF IN THE AFTERNOON HOURS. TEMPERATURES WILL
BE ON THE COOL SIDE...WITH HIGHS IN THE LOWER 20S.
HIGH PRESSURE WILL RIDGE INTO THE REGION SATURDAY NIGHT...RESULTING
IN QUITE CHILLY OVERNIGHT LOWS. THE HIGH WILL BRING LIGHT WINDS AND
AND MOSTLY CLEAR SKIES WHICH IS GOOD FOR RADIATIONAL
COOLING...HOWEVER TEMPERATURES ALOFT WILL START TO WARM WHICH WILL
LIMIT LOWS A BIT. EXPECT LOW TEMPERATURES TO VARY WIDELY...WITH
SINGLE DIGITS COMMON IN MOST LOCATIONS...AND SUB-ZERO TEMPERATURES
EAST OF LAKE ONTARIO AND IN THE TYPICALLY COOLER VALLEYS. THE HIGH
WILL SLIDE TO THE EAST ON SUNDAY...PROVIDING A GOOD AMOUNT OF
SUNSHINE...AND WARMER TEMPERATURES. EXPECT LOCATIONS WEST OF
ROCHESTER TO RISE INTO THE 30S AND ABOVE FREEZING...WITH SLIGHTLY
COOLER TEMPERATURES TO THE EAST.
AS WE MOVE INTO SUNDAY NIGHT THE FOCUS SHIFTS TO THE NEXT SYSTEM
THAT WILL BE IMPACTING THE REGION. AN UPPER LEVEL LOW EJECTING OUT
OF THE DESERT SOUTHWEST WILL GENERATE A LEE CYCLONE OVER THE HIGH
PLAINS THAT WILL TRACK TO THE WESTERN GREAT LAKES BY SUNDAY NIGHT.
AS THIS LARGE STORM SYSTEM LIFTS NORTHEAST...THE TRIPLE POINT OF THE
LOW IS PROGGED TO ROTATE ACROSS WESTERN NEW YORK MONDAY MORNING WITH
WIDESPREAD PRECIP ACCOMPANYING THE FEATURE. THE AIR IN PLACE WILL
STILL BE FAIRLY COLD...AND WINDS AHEAD OF THE SYSTEM MAY NOT BE
STRONG ENOUGH TO DISPLACE THIS COLD AIR AT THE ONSET. GIVEN WARMING
DURING THE DAY ON SUNDAY...FEEL THAT AT LEAST ACROSS THE NIAGARA
FRONTIER AND NORTHERN GENESEE VALLEY TEMPERATURES WILL PROBABLY STAY
ABOVE FREEZING. COLDER AIR IN PLACE FARTHER EAST ACROSS THE FINGER
LAKES AND NORTH COUNTRY HOWEVER COULD PRESENT MORE OF A PROBLEM WITH
REGARDS TO FREEZING RAIN LATE SUNDAY NIGHT INTO MONDAY. A CONSENSUS
OF QPF AMONG THE GGEM/EUROPEAN/GFS BRINGS ABOUT QUARTER INCH. WARM
AIR WILL EVENTUALLY WIN OUT ON MONDAY...WITH TEMPERATURES EVENTUALLY
CLIMBING INTO THE 40S IN MOST LOCATIONS.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
RAIN WILL EXIT EAST AS THE LOW TRACKS NORTH OF OUR REGION MONDAY
NIGHT AND COLDER AIR ONCE AGAIN FILTERS INTO THE REGION...THOUGH
GIVEN THAT THE LOW WILL BE DEEPLY OCCLUDED...AIRMASS ADVECTION
SHOULD NOT BE THAT COLD INITIALLY WITH 850MB TEMPS ONLY IN THE
NEIGHBORHOOD OF -6C TO -10C WITH TEMPS FALLING FROM THE 40S MONDAY
AFTERNOON INTO THE LOW TO MID 30S TUESDAY. GIVEN THE LACK OF DEEP
COLD AIR...NOT EXPECTING LAKE EFFECT SHOWERS WILL PRESENT MUCH OF A
PROBLEM. WEAK RIDGING BUILDS ACROSS THE OHIO VALLEY WEDNESDAY WITH
LIGHT WESTERLY FLOW AND MARGINALLY COLD TEMPERATURES BEING JUST
ENOUGH TO KEEP AT LEAST A LOW CHANCE OF LAKE EFFECT SHOWERS DOWNWIND
OF THE LAKES.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
SNOW WILL CONTINUE TO SPREAD ACROSS THE REGION THROUGH THIS
MORNING...BUT WILL BE LIGHT AT THE ONSET. PRECIPITATION MAY START
AS PL/FZRA AT JHW AND POSSIBLY BUF/ROC. ANY MIXED PRECIPITATION
WILL BE SHORT-LIVED AS COLDER AIR BUILDS IN LATER THIS MORNING.
THERE ALSO IS A 40 TO 50 KNOT LOW LEVEL JET WHICH WILL BRIEFLY
CROSS THE REGION THROUGH THIS MORNING...HOWEVER IT WILL NOT MIX
DOWN TO THE SURFACE RESULTING IN MODEST LLWS.
A PERIOD OF HEAVIER SNOW WILL MOVE IN THIS AFTERNOON FROM WEST TO
EAST. THIS WILL RESULT IN A SIGNIFICANT PERIOD OF VSBY BELOW
1SM...WITH PERIODS OF 1/4SM TO 1/2SM IN MODERATE TO HEAVY SNOW.
SNOW ACCUMULATIONS OF AN INCH AN HOUR ARE ALSO LIKELY.
CONDITIONS WILL IMPROVE FROM W-E THIS EVENING. A NORTHERLY FLOW
OFF THE LAKES WILL CAUSE MVFR CIGS AND LIGHT SNOW SHOWERS TO
LINGER SOUTH OF THE LAKES LATE TONIGHT.
OUTLOOK...
SATURDAY AND SUNDAY...VFR.
MONDAY...MVFR WITH RAIN AND POSSIBLE MIXED PCPN SPREADING EAST
ACROSS THE AREA.
TUESDAY...MVFR IN LIGHT SNOW.
&&
.MARINE...
AN AREA OF LOW PRESSURE OVER THE WESTERN END OF LAKE ERIE WILL
ADVANCE EASTWARD TOWARDS WESTERN NEW YORK BEFORE BECOMING ABSORBED
BY A DEEPENING AREA OF LOW PRESSURE ALONG THE EAST COASTLINE. THIS
WILL BRING A PERIOD OF GUSTY NORTHEAST WINDS BACKING TO NORTH...AND
THEN NORTHWEST THROUGH SATURDAY. SMALL CRAFTS CONDITIONS ON BOTH
LAKES TODAY AND TONIGHT BEFORE WINDS AND WAVES DROP BELOW SMALL
CRAFT LEVELS THROUGH THE NIGHT. ALSO A SMALL CRAFT WILL BE ISSUED
FOR THE LOWER NIAGARA RIVER WHERE NORTHERLY WINDS WILL FUNNEL UP THE
RIVER GORGE 15 TO 25 KNOTS. AN AREA OF HIGH PRESSURE WILL SETTLE
OVER THE LAKES SATURDAY AND SUNDAY WITH A PERIOD OF BELOW SMALL
CRAFT CONDITIONS LATER SATURDAY AND THROUGH MONDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER STORM WARNING UNTIL 5 AM EST SATURDAY FOR NYZ001>008-
010-011.
WINTER WEATHER ADVISORY UNTIL 5 AM EST SATURDAY FOR NYZ012>014-
019>021-085.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM EST
SATURDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 4 AM EST SATURDAY FOR
LOZ030.
SMALL CRAFT ADVISORY UNTIL 6 PM EST SATURDAY FOR LOZ043.
SMALL CRAFT ADVISORY UNTIL 1 PM EST SATURDAY FOR LOZ042.
SMALL CRAFT ADVISORY UNTIL 8 AM EST SATURDAY FOR LOZ045.
SMALL CRAFT ADVISORY UNTIL 4 PM EST SATURDAY FOR LOZ044.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...THOMAS/TMA
SHORT TERM...APFFEL
LONG TERM...WOOD
AVIATION...APFFEL
MARINE...THOMAS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
540 PM EST FRI FEB 8 2013
.SYNOPSIS...
COOL AND DRY HIGH PRESSURE WILL MOVE INTO THE CAROLINAS THROUGH
TONIGHT BEHIND A DEPARTING STORM SYSTEM...REMAINING OVER THE AREA ON
SATURDAY. THIS HIGH PRESSURE WILL SLIP OFF THE COAST SUNDAY AHEAD
OF AN APPROACHING COLD FRONT. THE COLD FRONT WILL STALL NEAR THE
AREA THROUGH THE MIDDLE OF NEXT WEEK...BRINGING RAIN CHANCES
MONDAY THROUGH WEDNESDAY. DRY HIGH PRESSURE WILL RETURN FOR THE
END OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 3 PM FRIDAY...A RICKETY COLD FRONT CROSSING THE EASTERN
APPALACHIAN FOOTHILLS WILL PROMPT A BACKING OF SURFACE WINDS
TO THE SOUTHWEST IN THE LATE AFTERNOON TO VERY EARLY EVENING
BEFORE CROSSING THE IMMEDIATE COAST IN THE MID-EVENING FOLLOWED
BY A RESURGENCE IN NW WINDS AND MODERATE COLD AIR ADVECTION FOR
THE OVERNIGHT PERIOD. SUITE OF HIGH RESOLUTION NEAR-TERM MODELS
SUCH AS THE HRRR AND NSSL WRF SUGGEST A COUPLE LIGHT SHOWERS IN
PASSING OF THIS FRAIL FRONT BETWEEN 500PM-900PM ACROSS OUR CWA.
QPF VALUES WILL REMAIN EXCEEDINGLY LOW AND NO GUARANTEE OF RAIN
MEASURING BEYOND A TRACE BUT TIME SECTIONS SHOW ADEQUATE RH AND
WEAK LIFT WARRANTING A SLIGHT CHANCE OF A FEW SHOWERS LATE THIS
AFTERNOON TO MIDDLE EVENING.
COLD AIR ADVECTION AND CLEARING LATE EVENING AND OVERNIGHT WILL
BRING CHILLY TEMPERATURES INTO DAYBREAK SATURDAY...MAINLY NEAR
30 DEGREES OVER THE FAR W-NW INTERIOR AND MIDDLE 30S NEAR AND
ALONG THE COAST. BRISK NW WINDS WILL PREVENT MINIMUM TEMPERATURES
FROM DIPPING AS LOW THEY COULD UNDER CLEARING SKIES...BUT
FACTORING IN THE WIND SHOULD PRODUCE APPARENT TEMPS/WIND CHILLS
IN THE MIDDLE TO UPPER 20S WITH FIRST LIGHT OF SATURDAY.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...VERY STRONG STORM SYSTEM WILL BE OFF THE NEW
ENGLAND COAST AT THE START OF THE PERIOD WITH SURFACE HIGH PRESSURE
RIDGING DOWN THE COAST BEHIND IT. AT THE SAME TIME...LONG WAVE RIDGE
BUILDS ACROSS THE EAST AT 500MB...WITH HEIGHTS RISING TO AS MUCH AS
576DM ON SUNDAY. THIS GENERALLY WOULD SUPPORT WARM AND QUIET
WEATHER...BUT A FEW CAVEATS WILL KEEP TEMPS SLIGHTLY COOL...AND
BRING INCREASINGLY UNSETTLED WEATHER AT THE END OF THE PERIOD.
AS SURFACE HIGH RIDGES DOWN BEHIND THE DEPARTING COASTAL
STORM...COOL NORTH WINDS WILL ENVELOP THE EASTERN CAROLINAS. AT THE
SAME TIME...AS THE RIDGE BUILDS ALOFT...LOW LEVEL THICKNESSES
INCREASE. THESE TWO WILL WORK AGAINST ONE ANOTHER...AND THE END
RESULT WILL BE A NEAR CLIMO DAY WITH AMPLE SUNSHINE ON SATURDAY.
HIGHS SATURDAY WILL REACH INTO THE MID 50S...APPROACHING 60 IN THE
FAR SOUTH. HIGH PRESSURE NEARLY OVERHEAD SATURDAY NIGHT WILL KEEP A
WEAK PRESSURE GRADIENT...AND ALTHOUGH SOME HIGH CLOUDS WILL BEGIN TO
FILTER IN DURING THE NIGHT...GOOD RADIATIONAL COOLING IS STILL
EXPECTED. THIS WILL HELP MINS FALL TO AROUND FREEZING...LOWER IN THE
TYPICALLY COLDER SPOTS.
SUNDAY IS A TRANSITION DAY AS SURFACE HIGH DRIFTS OFF THE
MID-ATLANTIC COAST SETTING UP WARM/MOIST RETURN FLOW INTO THE AREA.
MEANWHILE A SURFACE LOW WILL BE MOVING THROUGH THE GREAT PLAINS
PUSHING A COLD FRONT TOWARDS THE CAROLINAS. DECENT MOIST ADVECTION
OCCURS AHEAD OF THIS FRONT...AND A STRENGTHENING SOUTHERLY LLJ
OVERTOPPING THE WEAKENING RIDGE INCREASES ISENTROPIC LIFT IN
CONJUNCTION WITH ADVECTION OF THE MID-LEVEL THETA-E RIDGE. GUIDANCE
IN GOOD AGREEMENT IN OVERALL TIMING OF FEATURES LATE SUNDAY
NIGHT...BUT THE ECMWF IS A LITTLE MORE ROBUST WITH ITS LIFT AND
PRECIP POTENTIAL. WILL LEAN THIS DIRECTION BASED OFF RECENT ECMWF
PERFORMANCE...AND HENCE WILL SHOW POP INCREASING TO HIGH CHANCE AT
THE END OF THE PERIOD IN THE WEST...LOW CHANCE EAST.
SUNDAY WILL BE JUST A TAD WARMER THAN SATURDAY THANKS TO BREAKDOWN
OF COOL NORTH SURFACE FLOW...BUT OVERALL HEATING WILL BE
INCREASINGLY LIMITED BY CLOUD COVER. STILL EXPECT HIGHS IN THE UPPER
50S...LOW 60S FAR SOUTH. VERY LITTLE DIURNAL RANGE ANTICIPATED INTO
SUNDAY NIGHT THANKS TO CLOUDS AND RAIN...AND AN ATYPICAL DIURNAL
CURVE IS LIKELY WITH TEMPS FALLING JUST AFTER DARK...AND THEN
RISING SLOWLY THROUGH THE NIGHT. EARLY MINS WILL FALL INTO THE
MID/UPPER 40S BEFORE RISING TOWARDS DAYBREAK.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...A HIGH AMPLITUDE RIDGE WILL SHIFT OFFSHORE BY
THE START OF THE FORECAST PERIOD. LOW PRESSURE WILL MOVE ACROSS THE
GREAT LAKES AND INTO SE CANADA MON-TUE...DRAGGING A COLD FRONT INTO
THE EASTERN CAROLINAS LATE MON NIGHT AND TUE MORNING. A DEEP AND
RATHER MOIST SW TO WSW FLOW WILL QUICKLY DEVELOP AHEAD OF THE FRONT
WITH PRECIPITABLE WATER VALUES CLIMBING TO ABOUT AN INCH AND A HALF.
THE FRONT WILL BECOME PARALLEL TO THE MEAN FLOW...BECOMING MORE OR
LESS STATIONARY OVERHEAD OR JUST TO OUR S MID WEEK. A VIGOROUS
SOUTHERN STREAM SYSTEM WILL MOVE OUT OF THE FOUR CORNERS REGION
TUE...AIDING IN THE DEVELOPMENT OF LOW PRESSURE IN THE GULF OF
MEXICO. THIS AREA OF LOW PRESSURE WILL MOVE NE ALONG THE STALLED OUT
BOUNDARY AND ACROSS THE SOUTHEAST STATES TUE NIGHT AND WED. LOW
PRESSURE IS EXPECTED TO MOVE OFF THE CAROLINA COAST DURING WED AND
BEGIN TO INTENSIFY AS IT MOVES NE AND AWAY FROM THE AREA LATE DAY
AND WED NIGHT.
THUS...A VERY UNSETTLED PERIOD AND ALL OF THE AREA IS EXPECTED TO
RECEIVE PRECIPITATION SOMETIME DURING THE MON THROUGH WED TIME
FRAME. THE CHARACTER OF THE PRECIPITATION IS EXPECTED TO BE
STRATIFORM AS THE AREA OF LOW PRESSURE IS EXPECTED TO PASS S AND
THEN E OF THE FORECAST AREA. SHOULD THE GFS VERIFY...THEN THE AREA
OF LOW PRESSURE WOULD TRACK FURTHER N AND WITH THAT THERE MAY BE AT
LEAST SOME CONVECTIVE ELEMENTS AS THE PROXIMITY OF THE WARM SECTOR
WILL ALLOW FOR GREATER INSTABILITY. SINCE THE TIMING AND
JUXTAPOSITION OF THE SYNOPTIC FEATURES MAY STILL CHANGE SLIGHTLY...
I WAS HARD PRESSED TO GO CATEGORICAL FOR MOST AREAS DURING ANY
12-HOUR PERIOD. HOWEVER...SINCE THE AREA OF LOW PRESSURE WILL BE
MAKING ITS CLOSEST APPROACH AND THE STRONGEST SW LOW-LEVEL JET WILL
BE REALIZED TUE NIGHT AND EARLY WED...WILL BUMP POPS UP TO
CATEGORICAL DURING THIS TIME...EXCEPT FOR THE NW CORNER OF THE
FORECAST AREA.
HIGH PRESSURE WILL FILL IN BEHIND THE DEPARTING AREA OF LOW
PRESSURE...MOVING FROM THE GULF COAST STATES THU TO THE SOUTHEAST
STATES FRI.
ABUNDANCE OF CLOUDS MON THROUGH WED WILL KEEP LOWS WELL ABOVE NORMAL
BOTH MON AND TUE NIGHT. HIGHS WILL ALSO BE ABOVE NORMAL AS THERE
WILL BE NO INFLUX OF COLDER AIR EVEN BEHIND THE COLD FRONT. AS LOW
PRESSURE INTENSIFIES AS IT MOVES AWAY FROM THE CAROLINA COAST
WED...IT WILL BRING COLDER AND DRIER AIR INTO THE EASTERN CAROLINAS.
TEMPERATURES WILL RETURN TO MORE SEASONABLE LEVELS LATE WEEK.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...SECONDARY FRONT...MODIFIED ARCTIC AIR...WILL SPILL INTO
THE REGION THROUGH THE OVERNIGHT HOURS. A BRIEF STRATA CU CEILING
WILL OCCUR BRIEFLY AS THE FRONT PASSES THROUGH. HIGH CONFIDENCE FOR
VFR CONDITIONS. WEST WINDS WILL SHIFT TO THE NORTH NORTHWEST ON
SATURDAY AS HIGH PRESSURE BUILDS IN. MODERATE GRADIENT WILL PRODUCE
GUSTS APPROACHING 20 KTS BY MIDDAY WITH WEAK COLD AIR ADVECTION.
EXTENDED OUTLOOK...VFR WILL PERSIST THROUGH THE WEEKEND. A NEAR
STATIONARY FRONT WILL SET UP ON MONDAY WITH UNSETTLED CONDITIONS
THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...EXERCISE CAUTION CONDITIONS WILL PREVAIL
ACROSS ALL WATERS THROUGH EVENING NOT ONLY FOR SETTLING SEAS
FROM THE PREVIOUS STORM SYSTEM...BUT A RESURGENCE OF NW WINDS
AS A COLD FRONT CROSSES THE WATERS LATE THIS EVENING. A SMALL
CRAFT ADVISORY HAS BEEN HOISTED FOR THE NC WATERS FROM MIDNIGHT
TO 6AM TO ADDRESS FREQUENT 25 KT NW WIND GUSTS EXPECTED.
ADDITIONALLY...THE INCREASING OFFSHORE WIND LATE TONIGHT WILL
COINCIDE WITH AN ASTRONOMICALLY LOW TIDE TO PRODUCE LOW-WATER
CONDITIONS A FEW HOURS EITHER SIDE OF MIDNIGHT AND AN MWS WAS
ISSUED EARLIER TO GET THE WORD OUT TO MARINERS. MODERATE W-WSW
WINDS INTO EVENING WILL TURN TO NW LATE TONIGHT AND INCREASE AS
THE FRONT CLEARS THE WATERS. IT APPEARS THE NW SURGE WILL BE
SHORT-LIVED AND THE ADVISORY WILL RUN THROUGH 600 AM SATURDAY.
NO TSTMS OR RESTRICTIONS TO VISIBILITY EXPECTED ON THE 0-20
NM WATERS THROUGH TONIGHT. SEAS WILL REMAIN SOMEWHAT AGITATED
AS W-NW WINDS INTERACT WITH RESIDUAL SE WAVES FROM THE PREVIOUS
STORM SYSTEM.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...HIGH PRESSURE RIDGES DOWN FROM THE NORTH
BEHIND A POWERFUL COASTAL STORM WHICH WILL BE MOVING SLOWLY OFF THE
NEW ENGLAND COAST AT THE START OF THE PERIOD. THIS CREATES GUSTY
N/NW WINDS OF 15-20 KTS EARLY SATURDAY...EASING THROUGH THE DAY TO
AROUND 10 KTS WHILE VEERING TO THE NE BY SUNDAY MORNING. SEAS OF 2-4
FT EARLY WILL QUICKLY FALL TO 1-3 FT...LOWEST NEAR SHORE...DUE TO
THE OFFSHORE FETCH. ON SUNDAY...HIGH PRESSURE DRIFTS OFFSHORE
ALLOWING WINDS TO VEER FROM NE TO SE...AND FINALLY S BY SUNDAY
NIGHT. THESE WINDS WILL GENERALLY BE 10-15 KTS...BUT INCREASE LATE
AHEAD OF AN ADVANCING COLD FRONT...UP TO 15-20 KTS. THESE WINDS HELP
DRIVE SEAS UPWARDS THROUGH THE DAY...BECOMING 4-6 FT AT THE VERY END
OF THE PERIOD...AND A SMALL CRAFT ADVISORY MAY BE NECESSARY.
LONG TERM/MONDAY THROUGH TUESDAY/...
AS OF 3 PM FRIDAY...UNSETTLED WEATHER IS EXPECTED ACROSS THE WATERS
THROUGH MID WEEK. SW WINDS ON MON WILL SHIFT TO NW AND THEN N LATE
MON NIGHT AND TUE MORNING BEHIND A COLD FRONT. THIS FRONT WILL
LIKELY STALL NEARBY WITH WINDS VEERING TO NE DURING TUE AND THEN ALL
THE WAY AROUND TO SE AND S TUE NIGHT AS LOW PRESSURE APPROACHES FROM
THE SW. AS LOW PRESSURE INTENSIFIES AS IT MOVES NE OF THE WATERS...
WINDS WILL VEER TO WESTERLY WED AFTERNOON. THE STRONGEST WINDS THIS
PERIOD ARE EXPECTED MON WHEN SW WINDS...UP TO 20 TO 25 KT...WILL
ALLOW SEAS TO BUILD TO 5 TO 7 FT AND A SMALL CRAFT ADVISORY MAY BE
ISSUED FOR AT LEAST PORTIONS OF THE WATERS WITH LATER FORECAST
ISSUANCES. WINDS AND SEAS WILL BE ON A DOWNWARD TREND MON NIGHT.
WINDS AND SEAS WILL BUILD AGAIN TUE NIGHT AND WED AS LOW PRESSURE
MOVES ACROSS THE AREA AND A SMALL CRAFT ADVISORY MAY BE REQUIRED FOR
PORTIONS OF THE WATERS ONCE AGAIN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EST
SATURDAY FOR AMZ250-252.
&&
$$
SYNOPSIS...JDW
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...RJD
AVIATION...43
MARINE...MJC/RJD/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
328 PM EST FRI FEB 8 2013
.SYNOPSIS...
COOL AND DRY HIGH PRESSURE WILL MOVE INTO THE CAROLINAS THROUGH
TONIGHT BEHIND A DEPARTING STORM SYSTEM...REMAINING OVER THE AREA ON
SATURDAY. THIS HIGH PRESSURE WILL SLIP OFF THE COAST SUNDAY AHEAD
OF AN APPROACHING COLD FRONT. THE COLD FRONT WILL STALL NEAR THE
AREA THROUGH THE MIDDLE OF NEXT WEEK...BRINGING RAIN CHANCES
MONDAY THROUGH WEDNESDAY. DRY HIGH PRESSURE WILL RETURN FOR THE
END OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 3 PM FRIDAY...A RICKETY COLD FRONT CROSSING THE EASTERN
APPALACHIAN FOOTHILLS WILL PROMPT A BACKING OF SURFACE WINDS
TO THE SOUTHWEST IN THE LATE AFTERNOON TO VERY EARLY EVENING
BEFORE CROSSING THE IMMEDIATE COAST IN THE MID-EVENING FOLLOWED
BY A RESURGENCE IN NW WINDS AND MODERATE COLD AIR ADVECTION FOR
THE OVERNIGHT PERIOD. SUITE OF HIGH RESOLUTION NEAR-TERM MODELS
SUCH AS THE HRRR AND NSSL WRF SUGGEST A COUPLE LIGHT SHOWERS IN
PASSING OF THIS FRAIL FRONT BETWEEN 500PM-900PM ACROSS OUR CWA.
QPF VALUES WILL REMAIN EXCEEDINGLY LOW AND NO GUARANTEE OF RAIN
MEASURING BEYOND A TRACE BUT TIME SECTIONS SHOW ADEQUATE RH AND
WEAK LIFT WARRANTING A SLIGHT CHANCE OF A FEW SHOWERS LATE THIS
AFTERNOON TO MIDDLE EVENING.
COLD AIR ADVECTION AND CLEARING LATE EVENING AND OVERNIGHT WILL
BRING CHILLY TEMPERATURES INTO DAYBREAK SATURDAY...MAINLY NEAR
30 DEGREES OVER THE FAR W-NW INTERIOR AND MIDDLE 30S NEAR AND
ALONG THE COAST. BRISK NW WINDS WILL PREVENT MINIMUM TEMPERATURES
FROM DIPPING AS LOW THEY COULD UNDER CLEARING SKIES...BUT
FACTORING IN THE WIND SHOULD PRODUCE APPARENT TEMPS/WIND CHILLS
IN THE MIDDLE TO UPPER 20S WITH FIRST LIGHT OF SATURDAY.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...VERY STRONG STORM SYSTEM WILL BE OFF THE NEW
ENGLAND COAST AT THE START OF THE PERIOD WITH SURFACE HIGH PRESSURE
RIDGING DOWN THE COAST BEHIND IT. AT THE SAME TIME...LONG WAVE RIDGE
BUILDS ACROSS THE EAST AT 500MB...WITH HEIGHTS RISING TO AS MUCH AS
576DM ON SUNDAY. THIS GENERALLY WOULD SUPPORT WARM AND QUIET
WEATHER...BUT A FEW CAVEATS WILL KEEP TEMPS SLIGHTLY COOL...AND
BRING INCREASINGLY UNSETTLED WEATHER AT THE END OF THE PERIOD.
AS SURFACE HIGH RIDGES DOWN BEHIND THE DEPARTING COASTAL
STORM...COOL NORTH WINDS WILL ENVELOP THE EASTERN CAROLINAS. AT THE
SAME TIME...AS THE RIDGE BUILDS ALOFT...LOW LEVEL THICKNESSES
INCREASE. THESE TWO WILL WORK AGAINST ONE ANOTHER...AND THE END
RESULT WILL BE A NEAR CLIMO DAY WITH AMPLE SUNSHINE ON SATURDAY.
HIGHS SATURDAY WILL REACH INTO THE MID 50S...APPROACHING 60 IN THE
FAR SOUTH. HIGH PRESSURE NEARLY OVERHEAD SATURDAY NIGHT WILL KEEP A
WEAK PRESSURE GRADIENT...AND ALTHOUGH SOME HIGH CLOUDS WILL BEGIN TO
FILTER IN DURING THE NIGHT...GOOD RADIATIONAL COOLING IS STILL
EXPECTED. THIS WILL HELP MINS FALL TO AROUND FREEZING...LOWER IN THE
TYPICALLY COLDER SPOTS.
SUNDAY IS A TRANSITION DAY AS SURFACE HIGH DRIFTS OFF THE
MID-ATLANTIC COAST SETTING UP WARM/MOIST RETURN FLOW INTO THE AREA.
MEANWHILE A SURFACE LOW WILL BE MOVING THROUGH THE GREAT PLAINS
PUSHING A COLD FRONT TOWARDS THE CAROLINAS. DECENT MOIST ADVECTION
OCCURS AHEAD OF THIS FRONT...AND A STRENGTHENING SOUTHERLY LLJ
OVERTOPPING THE WEAKENING RIDGE INCREASES ISENTROPIC LIFT IN
CONJUNCTION WITH ADVECTION OF THE MID-LEVEL THETA-E RIDGE. GUIDANCE
IN GOOD AGREEMENT IN OVERALL TIMING OF FEATURES LATE SUNDAY
NIGHT...BUT THE ECMWF IS A LITTLE MORE ROBUST WITH ITS LIFT AND
PRECIP POTENTIAL. WILL LEAN THIS DIRECTION BASED OFF RECENT ECMWF
PERFORMANCE...AND HENCE WILL SHOW POP INCREASING TO HIGH CHANCE AT
THE END OF THE PERIOD IN THE WEST...LOW CHANCE EAST.
SUNDAY WILL BE JUST A TAD WARMER THAN SATURDAY THANKS TO BREAKDOWN
OF COOL NORTH SURFACE FLOW...BUT OVERALL HEATING WILL BE
INCREASINGLY LIMITED BY CLOUD COVER. STILL EXPECT HIGHS IN THE UPPER
50S...LOW 60S FAR SOUTH. VERY LITTLE DIURNAL RANGE ANTICIPATED INTO
SUNDAY NIGHT THANKS TO CLOUDS AND RAIN...AND AN ATYPICAL DIURNAL
CURVE IS LIKELY WITH TEMPS FALLING JUST AFTER DARK...AND THEN
RISING SLOWLY THROUGH THE NIGHT. EARLY MINS WILL FALL INTO THE
MID/UPPER 40S BEFORE RISING TOWARDS DAYBREAK.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...A HIGH AMPLITUDE RIDGE WILL SHIFT OFFSHORE BY
THE START OF THE FORECAST PERIOD. LOW PRESSURE WILL MOVE ACROSS THE
GREAT LAKES AND INTO SE CANADA MON-TUE...DRAGGING A COLD FRONT INTO
THE EASTERN CAROLINAS LATE MON NIGHT AND TUE MORNING. A DEEP AND
RATHER MOIST SW TO WSW FLOW WILL QUICKLY DEVELOP AHEAD OF THE FRONT
WITH PRECIPITABLE WATER VALUES CLIMBING TO ABOUT AN INCH AND A HALF.
THE FRONT WILL BECOME PARALLEL TO THE MEAN FLOW...BECOMING MORE OR
LESS STATIONARY OVERHEAD OR JUST TO OUR S MID WEEK. A VIGOROUS
SOUTHERN STREAM SYSTEM WILL MOVE OUT OF THE FOUR CORNERS REGION
TUE...AIDING IN THE DEVELOPMENT OF LOW PRESSURE IN THE GULF OF
MEXICO. THIS AREA OF LOW PRESSURE WILL MOVE NE ALONG THE STALLED OUT
BOUNDARY AND ACROSS THE SOUTHEAST STATES TUE NIGHT AND WED. LOW
PRESSURE IS EXPECTED TO MOVE OFF THE CAROLINA COAST DURING WED AND
BEGIN TO INTENSIFY AS IT MOVES NE AND AWAY FROM THE AREA LATE DAY
AND WED NIGHT.
THUS...A VERY UNSETTLED PERIOD AND ALL OF THE AREA IS EXPECTED TO
RECEIVE PRECIPITATION SOMETIME DURING THE MON THROUGH WED TIME
FRAME. THE CHARACTER OF THE PRECIPITATION IS EXPECTED TO BE
STRATIFORM AS THE AREA OF LOW PRESSURE IS EXPECTED TO PASS S AND
THEN E OF THE FORECAST AREA. SHOULD THE GFS VERIFY...THEN THE AREA
OF LOW PRESSURE WOULD TRACK FURTHER N AND WITH THAT THERE MAY BE AT
LEAST SOME CONVECTIVE ELEMENTS AS THE PROXIMITY OF THE WARM SECTOR
WILL ALLOW FOR GREATER INSTABILITY. SINCE THE TIMING AND
JUXTAPOSITION OF THE SYNOPTIC FEATURES MAY STILL CHANGE SLIGHTLY...
I WAS HARD PRESSED TO GO CATEGORICAL FOR MOST AREAS DURING ANY
12-HOUR PERIOD. HOWEVER...SINCE THE AREA OF LOW PRESSURE WILL BE
MAKING ITS CLOSEST APPROACH AND THE STRONGEST SW LOW-LEVEL JET WILL
BE REALIZED TUE NIGHT AND EARLY WED...WILL BUMP POPS UP TO
CATEGORICAL DURING THIS TIME...EXCEPT FOR THE NW CORNER OF THE
FORECAST AREA.
HIGH PRESSURE WILL FILL IN BEHIND THE DEPARTING AREA OF LOW
PRESSURE...MOVING FROM THE GULF COAST STATES THU TO THE SOUTHEAST
STATES FRI.
ABUNDANCE OF CLOUDS MON THROUGH WED WILL KEEP LOWS WELL ABOVE NORMAL
BOTH MON AND TUE NIGHT. HIGHS WILL ALSO BE ABOVE NORMAL AS THERE
WILL BE NO INFLUX OF COLDER AIR EVEN BEHIND THE COLD FRONT. AS LOW
PRESSURE INTENSIFIES AS IT MOVES AWAY FROM THE CAROLINA COAST
WED...IT WILL BRING COLDER AND DRIER AIR INTO THE EASTERN CAROLINAS.
TEMPERATURES WILL RETURN TO MORE SEASONABLE LEVELS LATE WEEK.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...VISIBLE SATELLITE IMAGERY SHOWS THE LOW STRATUS THAT
PLAGUED THE INLAND TERMINALS THIS MORNING IS RAPIDLY DISSIPATING. A
FEW LOW CLOUDS COULD LINGER FOR ANOTHER HOUR OR SO...BUT OTHERWISE
SOME CLEARING APPEARS LIKELY THIS AFTERNOON. LOW CLOUD COVER WILL
INCREASE AGAIN THIS EVENING AS A SECONDARY COLD FRONT AND ASSOCIATED
SHORTWAVE TROUGH MOVE THROUGH THE AREA. DO NOT ANTICIPATE ANYTHING
WORSE THAN A BRIEF PERIOD OF VFR CIGS AT THIS TIME. AFTER FROPA...
THE SKIES WILL CLEAR OUT WITH VFR PERSISTING THROUGH THE REST OF THE
TAF PERIOD. WEST-NORTHWEST WINDS 10 TO 12 KTS THIS AFTERNOON WILL
BECOME NORTH-NORTHWEST AFTER 00Z SATURDAY...REMAINING AROUND 10 KTS.
KILM CONTINUES TO SEE GUSTS AROUND 20 KTS...SO HAVE KEPT GUSTY
CONDITIONS HERE THROUGH THE AFTERNOON HOURS.
EXTENDED OUTLOOK...VFR WILL PERSIST THROUGH THE WEEKEND. RAIN LIKELY
WITH SUB-VFR CONDITIONS POSSIBLE MONDAY THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...EXERCISE CAUTION CONDITIONS WILL PREVAIL
ACROSS ALL WATERS THROUGH EVENING NOT ONLY FOR SETTLING SEAS
FROM THE PREVIOUS STORM SYSTEM...BUT A RESURGENCE OF NW WINDS
AS A COLD FRONT CROSSES THE WATERS LATE THIS EVENING. A SMALL
CRAFT ADVISORY HAS BEEN HOISTED FOR THE NC WATERS FROM MIDNIGHT
TO 6AM TO ADDRESS FREQUENT 25 KT NW WIND GUSTS EXPECTED.
ADDITIONALLY...THE INCREASING OFFSHORE WIND LATE TONIGHT WILL
COINCIDE WITH AN ASTRONOMICALLY LOW TIDE TO PRODUCE LOW-WATER
CONDITIONS A FEW HOURS EITHER SIDE OF MIDNIGHT AND AN MWS WAS
ISSUED EARLIER TO GET THE WORD OUT TO MARINERS. MODERATE W-WSW
WINDS INTO EVENING WILL TURN TO NW LATE TONIGHT AND INCREASE AS
THE FRONT CLEARS THE WATERS. IT APPEARS THE NW SURGE WILL BE
SHORT-LIVED AND THE ADVISORY WILL RUN THROUGH 600 AM SATURDAY.
NO TSTMS OR RESTRICTIONS TO VISIBILITY EXPECTED ON THE 0-20
NM WATERS THROUGH TONIGHT. SEAS WILL REMAIN SOMEWHAT AGITATED
AS W-NW WINDS INTERACT WITH RESIDUAL SE WAVES FROM THE PREVIOUS
STORM SYSTEM.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...HIGH PRESSURE RIDGES DOWN FROM THE NORTH
BEHIND A POWERFUL COASTAL STORM WHICH WILL BE MOVING SLOWLY OFF THE
NEW ENGLAND COAST AT THE START OF THE PERIOD. THIS CREATES GUSTY
N/NW WINDS OF 15-20 KTS EARLY SATURDAY...EASING THROUGH THE DAY TO
AROUND 10 KTS WHILE VEERING TO THE NE BY SUNDAY MORNING. SEAS OF 2-4
FT EARLY WILL QUICKLY FALL TO 1-3 FT...LOWEST NEAR SHORE...DUE TO
THE OFFSHORE FETCH. ON SUNDAY...HIGH PRESSURE DRIFTS OFFSHORE
ALLOWING WINDS TO VEER FROM NE TO SE...AND FINALLY S BY SUNDAY
NIGHT. THESE WINDS WILL GENERALLY BE 10-15 KTS...BUT INCREASE LATE
AHEAD OF AN ADVANCING COLD FRONT...UP TO 15-20 KTS. THESE WINDS HELP
DRIVE SEAS UPWARDS THROUGH THE DAY...BECOMING 4-6 FT AT THE VERY END
OF THE PERIOD...AND A SMALL CRAFT ADVISORY MAY BE NECESSARY.
LONG TERM/MONDAY THROUGH TUESDAY/...
AS OF 3 PM FRIDAY...UNSETTLED WEATHER IS EXPECTED ACROSS THE WATERS
THROUGH MID WEEK. SW WINDS ON MON WILL SHIFT TO NW AND THEN N LATE
MON NIGHT AND TUE MORNING BEHIND A COLD FRONT. THIS FRONT WILL
LIKELY STALL NEARBY WITH WINDS VEERING TO NE DURING TUE AND THEN ALL
THE WAY AROUND TO SE AND S TUE NIGHT AS LOW PRESSURE APPROACHES FROM
THE SW. AS LOW PRESSURE INTENSIFIES AS IT MOVES NE OF THE WATERS...
WINDS WILL VEER TO WESTERLY WED AFTERNOON. THE STRONGEST WINDS THIS
PERIOD ARE EXPECTED MON WHEN SW WINDS...UP TO 20 TO 25 KT...WILL
ALLOW SEAS TO BUILD TO 5 TO 7 FT AND A SMALL CRAFT ADVISORY MAY BE
ISSUED FOR AT LEAST PORTIONS OF THE WATERS WITH LATER FORECAST
ISSUANCES. WINDS AND SEAS WILL BE ON A DOWNWARD TREND MON NIGHT.
WINDS AND SEAS WILL BUILD AGAIN TUE NIGHT AND WED AS LOW PRESSURE
MOVES ACROSS THE AREA AND A SMALL CRAFT ADVISORY MAY BE REQUIRED FOR
PORTIONS OF THE WATERS ONCE AGAIN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EST
SATURDAY FOR AMZ250-252.
&&
$$
SYNOPSIS...JDW
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...RJD
AVIATION...MJC/BJR
MARINE...MJC/RJD/JDW
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
126 AM EST FRI FEB 8 2013
.SYNOPSIS...
A STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL MOVE THROUGH
EASTERN NC THROUGH EARLY FRIDAY MORNING. HIGH PRESSURE WILL BUILD
INTO THE AREA FROM THE NORTH SATURDAY THEN SETTLE OFFSHORE SUNDAY
AND MONDAY. A COLD FRONT WILL APPROACH FROM THE WEST MONDAY NIGHT
AND SLOWLY MOVE THROUGH THE AREA ON TUESDAY. HIGH PRESSURE BUILDS
IN FROM THE WEST BY MID WEEK.
&&
.NEAR TERM /EARLY THIS MORNING/...
AS OF 115 AM FRI...INCREASED WINDS SIGNIFICANTLY ALONG THE CRYSTAL
COAST INLAND TO A LINE FROM NEAR RICHLANDS TO NEW BERN AND THE
CENTRAL PAMLICO SOUND AS RECENT WINDS HAVE AVERAGED ABOUT 10 KNOTS
HIGHER THAN LATEST GUIDANCE. LATEST RUN OF HRRR CLOSEST TO
OBSERVED VALUES...SO HAVE INCREASED WINDS ACCORDINGLY THROUGH THE
NEXT 6-9 HOURS AS WINDS WILL INCREASE IN ADVANCE OF THE DEEPENING
LOW PRESSURE CENTER CURRENTLY LOCATED NEAR FRYING PAN SHOALS OFF
CAPE FEAR. RAIN...HEAVY AT TIMES...WILL CONTINUE FOR THE NEXT FEW
HOURS THEN TAPER OFF CLOSER TO DAY BREAK FROM SW TO NE AS THE LOW
TRAVERSES THE REGION.
AS THE LOW PASSES THROUGH WINDS WILL BRIEFLY SHIFT OUT OF THE
SOUTH BY DAYBREAK ACROSS EAST NC...WHILE THE COASTAL PLAIN WINDS
WILL BE NORTHERLY. AXIS OF INSTABILITY WILL REMAIN JUST
OFFSHORE...SO NOT EXPECTING MUCH IN THE WAY OF CONVECTION OVER
LAND...THOUGH COULD SEE A FEW LIGHTNING STRIKES DOWNEAST CARTERET
COUNTY THROUGH THE SOUTHERN AND CENTRAL OBX. RAIN WILL BE HEAVY AT
TIMES TONIGHT WITH TOTALS IN THE 1 TO 3 INCH RANGE ACROSS A BROAD
AREA...WITH ISOLATED HIGHER AMOUNTS. COULD BE SOME ISOLATED
FLOODING OF POOR DRAINAGE AREAS BUT NO WIDESPREAD FLOODING ISSUES
ARE EXPECTED DUE TO ANTECEDENT DRY CONDITIONS.
&&
.SHORT TERM /FRIDAY/...
AS OF 4 PM THURSDAY..RAIN WILL RAPIDLY COME TO AN END FROM SW TO
NE ACROSS THE AREA EARLY FRI MORNING...PERHAPS LINGERING TO AROUND
NOON ACROSS THE FAR NE PORTIONS. SFC LOW WILL EXIT NC WHILE
DEEPENING. THIS WILL BRING WINDY CONDITIONS TO THE OBX AND EASTERN
MAINLAND...THOUGH ATTM LOOKS TO REMAIN JUST BELOW WIND ADVISORY
CRITERIA. TEMPS GENERALLY WILL TOP OUT IN THE MID TO UPPER 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
AFTER A SLIGHT CHANCE FRI EVENING FOR A SPRINKLE OR EVEN FLURRY
OVER THE OUTER BANKS...WINDS WILL REMAIN GUSTY FRIDAY NIGHT INTO
SATURDAY ESPECIALLY FOR COASTAL AREAS AS DEPARTING LOW PRESSURE
INTENSIFIES TO THE NORTHEAST. DEEP UPPER TROF MOVES OFFSHORE
ALLOWING FOR A MULTILAYER DRY NW FLOW TO PREVAIL FOR MUCH OF THE
UPCOMING WEEKEND. TEMPS WILL BE BELOW NORMAL OVER THE WEEKEND
WITH HIGHS 45 TO 50 SAT AND 50 TO 55 MOST SPOTS SUNDAY. LOWS
FRIDAY NIGHT WILL REACH TO NEAR OR JUST BELOW FREEZING OVER INLAND
AREAS. WITH NEAR IDEAL RADIATIONAL COOLING...MIN TEMPS SATURDAY
NIGHT WILL DIP INTO THE MID TO UPPER 20S AWAY FROM THE COAST.
CLOUDS INCREASE LATE IN THE WEEKEND AHEAD OF THE SYSTEM.
THE NEXT CHANCES FOR PRECIP WILL ARRIVE LATE SUNDAY NIGHT AND ON
MONDAY WITH THE APPROACH OF A MID LEVEL TROF. RAIN CUD START
BEFORE DAWN OVER FAR INLAND AREAS AS A WARM FRONT LIFTS NORTH
MONDAY MORNING. SCATTERED SHOWERS ARE EXPECTED TO BE PREVALENT
THROUGH THE EARLY PART OF NEXT WEEK GIVEN THE TENDENCY FOR THE
ASSOCD COLD FRONT TO SLOW DOWN AND POTENTIALLY STALL AS IT COMES
UNDER PARALLEL FLOW OVER THE REGION TUESDAY. A CONSENSUS OF THE
MODEL GUIDANCE SUGGESTS THE FRONT PUSHES THRU THE AREA ON
WEDNESDAY BUT MAY LIFT BACK NORTH ALONG THE COAST THURSDAY. WONT
BE MAKING MAJOR CHANGES TO THE LONGER RANGE FORECAST FOR NOW UNTIL
MODELS CAN BETTER RESOLVE THE SYNOPTIC DETAILS.
TEMPERATURES WILL START OUT ABOVE NORMAL EARLY NEXT WEEK THEN
TREND BACK TO NEAR MORE SEASONABLE LEVELS DURING MIDWEEK.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH FRIDAY/...
AS OF 1250 AM FRI...EXPECT IFR CONDITIONS TO PREVAIL THROUGH
ROUGHLY 13-14Z AS LOW CLOUDS AND MODERATE TO HEAVY RAIN IMPACT THE
TAF SITES. MAINTAINED MENTION OF LOW LEVEL WIND SHEAR AT ALL SITES
DUE TO STRONG/DEEPENING LOW THAT WILL TRAVERSE THE TERMINALS THIS
MORNING...WITH WINDS AROUND 50 KNOTS JUST OFF THE DECK. WINDS
WILL SLOWLY BACK FROM NORTHEAST TO NORTH LATE TONIGHT AND THEN
NORTHWEST EARLY FRIDAY. CONDITIONS WILL IMPROVE TO MVFR/VFR AFTER
AROUND 14Z FRI. WINDS WILL REMAIN GUSTY FRI DUE TO A STRONG
SURFACE GRADIENT BETWEEN HIGH PRESSURE BUILDING IN FROM THE SW AND
A DEEPENING LOW PRESSURE AREA ACROSS NEW ENGLAND.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
WINDS WILL BE GUSTY FRIDAY NIGHT AND SATURDAY...BUT MAINLY VFR
EXPECTED FOR MUCH OF THE UPCOMING WEEKEND AS HIGH PRES BUILDS
OVER THE REGION SAT AND SLOWLY SLIDES OFFSHORE LATE SUN. POTENTIAL
FOR SUB-VFR CONDITIONS RETURN AS A WARM FRONT LIFTS NORTH THRU
THE AREA MONDAY MORNING WITH DEEP MOISTURE OVERSPREADING THE
REGION THROUGH TUESDAY.
&&
.MARINE...
SHORT TERM /EARLY THIS MORNING THROUGH FRIDAY/...
AS OF 120 AM FRI...LATEST SURFACE...BUOY...AND SATELLITE DATA
INDICATE A DEEPENING AREA OF LOW PRESSURE JUST OFF THE CAPE FEAR
COAST...MOVING NE TOWARDS THE EASTERN NC COASTAL WATERS. HAVE
INCREASED WINDS TO GALE FORCE FOR ALL WATERS AS CLKN7 CONTINUES TO
REPORT 35+ KNOTS...ALONG WITH AN 0136Z ASCAT SCATTEROMETER WINDS
PASS THAT INDICATED A WIDE SWATH OF 30 KNOT WINDS FROM NEAR
DIAMOND SHOALS SW TO WELL OFF ONSLOW BAY. SEAS ROSE RAPIDLY
EARLIER TONIGHT WITH 41109 JUST 4 MILES OFF THE BEACH NOW
REPORTING 8 FEET AND BUOY 41036 30 MILES OFF ONSLOW BAY RECENTLY
REPORTED 14 FEET. SEAS ARE ALSO INCREASE ACROSS THE CENTRAL AND
NORTHERN WATERS...THUS HAVE TAILORED NEAR TERM SEAS CLOSER TO
OBSERVED AND INCREASED BY 1-2 FEET THROUGH THE NEXT 6-12 HOURS.
AS THE LOW DEPARTS TO THE NORTHEAST ON FRIDAY...RAPID DEEPENING
IS EXPECTED AND AS A RESULT...WINDS WILL INCREASE OUT OF THE
NORTHWEST TO GALE FORCE BY LATE MORNING. SEAS WILL REMAIN ELEVATED
THROUGH FRI AS WELL.
LONG TERM /FRI NIGHT THROUGH TUESDAY/...
LOW PRESSURE WILL QUICKLY LIFT WELL NE OF THE REGION FRI EVE. AS
HIGH PRES BUILDS IN FROM THE NW FRI NIGHT AND SAT STRONG N WINDS
EXPECTED AS GRDNT WILL REMAIN TIGHT WITH DEEP LOW PRES WELL TO THE
NE. AS THE HIGH BUILDS SLOWLY SE WINDS WILL GRAD DIMINISH SAT
NIGHT INTO SUN. LULL IN WINDS WILL BE BRIEF AS S/SW WINDS WILL
INCREASE MON AS HIGH MOVES OFF CST AND COLD FRONT APPROACHES FORM
THE W.
AS N WINDS INCREASE LATER FRI NIGHT AND SAT SEAS WILL BUILD TO 7 TO
10 FEET OVER OUTER CNTRL AND NRN WTRS. SEAS WILL BE SLOW TO COME
DOWN SAT NIGHT AND SUN AS EXPECT DECENT SWELL FROM THE DEEP LOW TO
THE NE. S/SW WINDS WILL RAMP UP TO 20 TO 25 KTS MOST WTRS MON
WITH SEAS 6-7 FT BY MON AFTN. SLOWLY DECREASING WIND/SEAS MON
NIGHT THRU TUESDAY AS HIGH PRES BUILDS INTO THE AREA.
&&
.TIDES/COASTAL FLOODING...
INCREASING WINDS AND HIGHER THAN NORMAL ASTRONOMICAL TIDES WILL
LEAD TO WATER LEVELS 1 TO 1.5 FT ABOVE NORMAL INTO THE EARLY PART
OF THE WEEKEND. NEARSHORE WAVES ARE EXPECTED TO REMAIN BELOW 8 FT
BUT BREAKING WAVES AND WAVE RUNUP WILL LEAD TO ROUGH SURF AND
POSSIBLE MINOR BEACH EROSION FOR THE NORTHERN OUTER BANKS THROUGH
SATURDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...GALE WARNING FROM 6 AM THIS MORNING TO 7 PM EST THIS EVENING
FOR AMZ130-135-150-152-154.
GALE WARNING UNTIL 3 PM EST THIS AFTERNOON FOR AMZ156-158.
&&
$$
SYNOPSIS...TL
NEAR TERM...DAG/TL
SHORT TERM...TL
LONG TERM...BTC
AVIATION...BTC/DAG
MARINE...BTC/DAG
TIDES/COASTAL FLOODING...BTC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1149 PM EST THU FEB 7 2013
.SYNOPSIS...
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE ACROSS NORTHERN OHIO
TONIGHT. THE LOW WILL WEAKEN FRIDAY AS ANOTHER DEEP LOW MOVES UP
THE EAST COAST TOWARD NEW ENGLAND. HIGH PRESSURE WILL BRIEFLY
RETURN FOR SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
REALLY STICKY SITUATION THIS EVENING WITH THE FORECAST OF A
POTENTIAL METEOROLOGICAL MESS IN STORE.
LATEST SURFACE ANALYSIS SHOWS LOW PRESSURE OVER INDIANAPOLIS WITH
A WARM FRONT EXTENDING NORTHEAST TO JUST SOUTH OF THE LAKE ERIE
SHORE LINE. FLOW TO THE SOUTH OF THE BOUNDARY IS FROM THE
SOUTHEAST AND NORTH OF THE BOUNDARY IS NORTHEAST. THIS NORTHEAST
FLOW IS OFF LAKE ERIE INTO LUCAS...WOOD...OTTAWA AND SANDUSKY
COUNTIES. WE HAVE TWO FORCES WORKING AGAINST US IN THIS AREA.
FIRST OF ALL...THE LAKE IS AROUND 32 DEGREES AND THE AIR MASS
NORTH OF THE LAKE IS IN THE UPPER 20S. I THINK THE COLD AIR WILL
CONTINUE TO HOLD IN PLACE BASED ON THE RUC MODEL AS THE LOW PASSES
BY TO THE EAST. THIS MEANS...WARM AIR ADVECTION ALOFT WILL BE
ENOUGH TO SUPPORT LIQUID PRECIPITATION OVER NORTHWEST OHIO. WITH
FREEZING TEMPERATURES AT THE SURFACE...FREEZING RAIN IS A GOOD
POSSIBILITY. A WINTER WEATHER ADVISORY WILL BE ISSUED FOR THIS
AREA STARTING NOW UNTIL 7 AM TOMORROW MORNING WHEN I EXPECT THE
PRECIPITATION TO BE IN THE FORM OF SNOW AND ENDING THREAT FOR
FREEZING RAIN.
NOW...FOR NORTHWEST PENNSYLVANIA. THE BOUNDARY LIES JUST SOUTH OF
THAT AREA AS WELL ALLOWING THE COLD AIR TO HOLD IN PLACE FOR THE
TIME BEING. I THINK THE TEMPERATURES WILL GRADUALLY WARM ABOVE THE
FREEZING MARK LATER TONIGHT BUT PRECIPITATION COULD BE FREEZING
RAIN AT THE ONSET AND THEN CHANGE TO RAIN. WILL GO AHEAD AND ISSUE
A WINTER WEATHER ADVISORY FOR ASHTABULA...ERIE AND CRAWFORD
COUNTIES STARTING AROUND 1 AM AND CONTINUE IT UNTIL 7 PM FRIDAY.
ADVISORY WILL ALSO ACCOUNT FOR THE SNOW ACCUMULATIONS OF UP TO 4
INCHES IN THAT AREA INTO FRIDAY.
THE REST OF THE FORECAST AREA WILL LIKELY SEE RAIN OR A MIX OF
RAIN AND SNOW WITH SOME POSSIBLE BRIEF FREEZING RAIN NEAR THE LAKE
SHORE BUT NOT ENOUGH TO CAUSE PROBLEMS.
A SURGE OF WARM AIR ADVECTION WILL TAKE PLACE OVERNIGHT AND
TEMPERATURES WILL RISE ACROSS THE CENTRAL PORTIONS OF THE FORECAST
AREA.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
BIG STORY FOR THE SHORT TERM IS THE STRONG EAST COAST STORM FRIDAY
THROUGH SATURDAY. MODELS INDICATE PRECIP WILL CHANGE TO SNOW
ACROSS NWRN PA EARLY ON FRIDAY AND THEN SNOW MUCH OF THE DAY. WILL
NEED TO WATCH THIS... RIGHT NOW HAVE 2 TO 4 INCHES IN THE FORECAST
BUT DEPENDING ON HOW THE MOISTURE LINES UP COULD END UP BEING A
COUPLE MORE. SNOW SHOWERS CONTINUING EAST ON FRIDAY NIGHT
EARLY...BEFORE DRIER AIR MOVES INTO THE AREA AS HIGH PRESSURE
BUILDS ACROSS THE GREAT LAKES. NEXT CHANCE PF PRECIP WILL COME
SUNDAY NIGHT INTO MONDAY WITH LOW PRESSURE MOVING THROUGH THE
WESTERN LAKES. WILL HAVE LIKELY TO CAT POPS FOR RAIN.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
UPPER LEVEL LOW WILL SLIDE EAST ACROSS THE GREAT LAKES REGION ON
MONDAY. A GOOD SURGE OF MOISTURE AND SHOWERS ASSOCIATED WITH THE
PASSING UPPER LOW MAY LINGER INTO MONDAY...ESPECIALLY IN THE EAST
BEFORE UPPER LEVEL JET AND CONSIDERABLE MID-LEVEL DRY SLOT
OVERSPREAD THE AREA AND SHOWERS DIMINISH. AFTER A WARM START TO THE
DAY...FALLING TEMPERATURES CAN BE EXPECTED. THIS WILL LEAVE AN
ELONGATED UPPER LEVEL TROUGH IN PLACE FROM NEAR QUEBEC TO THE DESERT
SOUTHWEST. ASSOCIATED SURFACE TROUGH WILL SINK SOUTH LATE TUESDAY
BRINGING AN INCREASE IN LOW LEVEL MOISTURE AND SCATTERED LIGHT SNOW
SHOWERS. TEMPERATURES OVER LAKE ERIE WILL BE MARGINAL FOR LAKE
EFFECT SNOW SO ONLY EXPECTING MINOR ACCUMULATIONS IN FAVORED
EASTERLY FLOW AREAS. HIGHS WILL BE NEAR NORMAL FOR MID FEBRUARY ON
TUESDAY AND WEDNESDAY.
LONG WAVE TROUGH AXIS EVENTUALLY SHIFTS TOWARDS THE EAST COAST BY
MID-WEEK WITH RIDGING AT THE SURFACE AND ALOFT BUILDING TOWARDS THE
GREAT LAKES. THE 12Z GFS IS AN OUTLIER IN TRACKING A LOW PRESSURE
SYSTEM UP THE EAST SIDE OF THE APPALACHIANS AND WILL LEAN TOWARDS
THE DRIER CONSENSUS FOR NOW.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
A LOW AND ITS ASSOCIATED COLD FRONT WILL MOVE ACROSS OHIO LATE
TONIGHT AND FRIDAY MORNING. CONDITIONS WILL DETERIORATE RAPIDLY
AFTER MIDNIGHT. PRECIPITATION WAS OVER THE TOL AND FDY AREAS AT
MIDNIGHT. THE PRECIPITATION WILL REACH THE OHIO AND PA BORDER
BEFORE DAYBREAK. MOST AREAS WILL JUST HAVE RAIN...TOL AND NW PA
ARE THE EXCEPTIONS...IT WILL BE A MIX. A FLOW OFF THE LAKE COULD
KEEP TOL FREEZING RAIN FOR A BIT BEFORE THE WIND SHIFT. A
DOWNSLOPE FLOW AT ERI SHOULD KEEP THE THREAT OF FREEZING RAIN LOW.
A DRY SLOT WILL OCCUR FOR A SHORT TIME AFTER THE FRONTAL PASSAGE
AND THEN THE PRECIPITATION WILL GO OVER TO SNOW OR SNOW SHOWERS.
IT IS POSSIBLE IN THIS TRANSITION THAT A VERY BRIEF PERIOD OF
SLEET OR EVEN A LITTLE FREEZING RAIN COULD OCCUR. THE THREAT OF
FREEZING RAIN IS LOW AT MOST TAF SITES...SO WILL NOT MENTION IT.
CONDITIONS IN THE RAIN WILL BE A MIX OF IFR AND MVFR AND THEN
WHEN THE SNOW BEGIN MAINLY IFR. THE BULK OF THE SNOW MAY BE MORE
OVER NE OH AND NW PA. CONDITIONS WILL BEGIN TO IMPROVE TO VFR OVER
NORTHWEST OHIO LATE.
MENTION LOW LEVEL WIND SHEAR IN SOME OF THE TAFS DURING THE EARLY
MORNING HOURS.
OUTLOOK...NON VFR MAINLY EAST FRIDAY NIGHT. SOME NON-VFR CONDITIONS
SUNDAY NIGHT INTO TUESDAY.
&&
.MARINE...
LOW PRESSURE CROSSING THE LAKE FRI MORNING WILL LEAD TO EAST FLOW
VEERING TO MORE SE INTO TONIGHT THEN AS THE LOW PASSES BY A N TO NW
FLOW WILL SET UP AND INCREASE TO 20 TO 30 KNOTS FRI THEN STEADILY
DIMINISH FRI NIGHT THROUGH MIDDAY SAT AS HIGH PRESSURE MOVES OVER
THE LAKE.
THE HIGH WILL MOVE EAST OF THE LAKE SUN AND AN INCREASING SE THEN S
FLOW WILL DEVELOP LATER SUN AND SUN NIGHT BECOMING SW ON MON. AIR
TEMPS BY MON WILL BE WARMER THAN THE LAKE SO THIS SHOULD HELP KEEP
WINDS FROM BECOMING AS STRONG AS WOULD OTHERWISE BE THE CASE. STILL
CAN SEE WINDS 15 TO 25 KNOTS LATE MON INTO TUE WHILE WINDS TURN WEST
WITH THE PASSAGE OF A COLD FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL 7 PM EST FRIDAY FOR OHZ014-089.
WINTER WEATHER ADVISORY UNTIL 7 AM EST FRIDAY FOR OHZ003-
006>008.
PA...WINTER WEATHER ADVISORY UNTIL 7 PM EST FRIDAY FOR PAZ001>003.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...LOMBARDY
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KIELTYKA
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS NORMAN OK
500 AM CST FRI FEB 8 2013
.AVIATION...
AREA OF LOW CLOUDS AND SOME ASSOCIATED PATCHY FOG IS
EXPECTED TO IMPACT PNC THIS MORNING. WILL NEED TO WATCH SOUTHWEST
PROGRESS AS THIS AREA OF CLOUD COVER WILL LIKELY APPROACH OKC/OUN
SITES AROUND 15Z. LATEST HRRR WOULD SUGGEST THAT PNC MAY KEEP MFVR
CEILING THROUGH MUCH OF THE DAY WITH FOG DISSIPATING BY MID/LATE
MORNING. OTHERWISE... ALL SITES WILL SEE INCREASE IN HIGH CLOUDS
THIS AFTN AND SOME MID CLOUD INCREASE AFTER MIDNIGHT.
30
&&
.PREV DISCUSSION... /ISSUED 339 AM CST FRI FEB 8 2013/
.DISCUSSION...
COLD FRONT HAS SWEPT THROUGH OKLAHOMA AND NORTH TEXAS WITH
COOLER...DRIER AIR IN ITS WAKE. HOWEVER SOME LOW CLOUDS AND FOG
WILL LIKELY AFFECT PARTS OF NORTH CENTRAL INTO CENTRAL OKLAHOMA
THIS MORNING... BEFORE DISSIPATING. STILL EXPECT PLENTY OF
SUNSHINE AND A MILD DAY AS TEMPS RECOVER INTO THE 50S AND LOW 60S
THIS AFTN WITH SOUTH WINDS RETURNING.
THESE SOUTH WINDS WILL BEGIN TO PULL MOISTURE BACK NORTHWARD IN
ADVANCE OF STRONGER UPPER LOW THAT WILL MOVE OUT OF THE SOUTHERN
ROCKIES INTO THE CENTRAL AND SOUTHERN PLAINS OVER THE WEEKEND.
WILL SEE SCATTERED SHOWERS AND POSSIBLE A FEW THUNDERSTORMS DURING
THE DAY ON SATURDAY... BUT BEST CHANCE WILL COME SATURDAY NIGHT AS
UPPER WAVE AND ASSOCIATED SFC BOUNDARIES MOVE ACROSS THE AREA. NOT
OUT OF THE QUESTION TO SEE SOME SEVERE WEATHER... BUT INSTABILITY
WILL BE LIMITED AND TIME OF DAY WILL ALSO INHIBIT SEVERE POTENTIAL
TO SOME DEGREE.
STORMS SHOULD EXIT EAST QUICKLY SUNDAY MORNING WITH MILD AND
BREEZY DAY EXPECTED. THESE CONDITIONS ALONG WITH LOW AFTN
HUMIDITIES WILL ELEVATE WILDFIRE CONCERNS ACROSS MUCH OF THE AREA
SUNDAY AFTN... BUT DO NOT ANTICIPATE REACHING RED FLAG CONDITIONS.
COOLER WEATHER THEN RETURNS EARLY NEXT WEEK WITH A LOW CHANCE FOR
A FEW RAIN OR EVEN SNOW SHOWERS MONDAY NIGHT INTO TUESDAY AS
SECONDARY WAVE DROPS QUICKLY SOUTH ON THE BACK SIDE OF EXITING
STORM SYSTEM. MOISTURE WILL BE LACKING WITH THIS DISTURBANCE AND
DO NOT ANTICIPATE SIGNIFICANT RAIN OR SNOW AT THIS TIME WITH THIS
SYSTEM. A MODEST WARM-UP IS THEN EXPECTED THROUGH THE LATTER PART
OF THE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 57 37 54 48 / 0 10 40 70
HOBART OK 58 36 56 41 / 0 10 40 60
WICHITA FALLS TX 61 39 60 48 / 0 10 40 60
GAGE OK 57 33 55 36 / 0 10 30 60
PONCA CITY OK 54 35 55 47 / 0 10 30 70
DURANT OK 60 39 59 53 / 10 10 40 80
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
23/30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
558 PM EST FRI FEB 8 2013
.SYNOPSIS...
AN AREA OF MODERATE SNOW WILL CROSS EASTERN PORTIONS OF CENTRAL
PA THROUGH THIS EVENING. A FEW TO SEVERAL INCHES OF SNOW WILL
ACCUMULATE QUICKLY...MAKING FOR A DIFFICULT EVENING RUSH FOR MANY.
HIGH PRESSURE WILL BUILD INTO THE AREA BEHIND THE STORM LATER
SATURDAY INTO SUNDAY. A FRONTAL SYSTEM MOVING EAST FROM THE
MIDWEST SHOULD BRING ANOTHER PERIOD OF MIXED PRECIPITATION ON
MONDAY.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
BACK EDGE OF MODERATE SNOW ASSOCIATED WITH NRN STREAM SHORTWAVE IS
PUSHING THRU THE SUSQ VALLEY EARLY THIS EVENING. A QUICK INCH OF
SNOW WAS REPORTED AT IPT LATE THIS AFTN AND WEB CAMS SHOW A
COATING TO AN INCH WAS FAIRLY COMMON ACROSS MUCH OF CENTRAL PA
THIS AFTN. LATEST RAP GUIDANCE SUGGESTS BACK EDGE OF STEADY SNOW
WILL CONTINUE PUSHING EAST THIS EVENING. THUS...HAVE CANCELED THE
WINTER WX ADVISORY FOR MOST OF THE AREA. WILL KEEP ADV GOING
ACROSS OUR NE COUNTIES FROM TIOGA SOUTH THRU SCHUYLKILL...WHICH
WILL BE MOST AFFECTED BY PERIODS OF LIGHTER SNOW OVERNIGHT ASSOC
WITH NORTHERN STREAM SHORTWAVE DROPPING ACROSS NE PA TONIGHT.
HAVE NOTICED INCREASING WGUSTS ACROSS THE LAUREL HIGHLANDS EARLY
THIS EVENING /JST GUSTED TO 35KTS AT 22Z/. EXPECT WINDS TO RAMP UP
MARKEDLY LATE THIS EVENING ACROSS THE ENTIRE REGION...AS PRES GRAD
TIGHTENS WEST OF DEVELOPING COASTAL STORM. WILL LIKELY BE
INCREASING WGUSTS WITH THE NEXT UPDATE AND MAY APPROACH WIND ADV
CRITERIA BASED ON A QUICK LOOK AT THE BUFKIT SOUNDING DATA.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH 6 AM SATURDAY/...
LINGERING SNOW SHOWERS WILL BE TAPERING OFF ACROSS OUR EASTERN
ZONES LATE TONIGHT AND UPSLOPE FLOW MAY PRODUCE A FEW LINGERING
-SHSN ACROSS THE W MTNS. TEMPS WILL PLUNGE INTO THE TEENS TO L20S
FOR MOST.
&&
.LONG TERM /SATURDAY THROUGH FRIDAY/...
THE TIGHT P-GRADIENT IN THE WAKE OF THE DEPARTING INTENSE LOW WILL
HELP TO CREATE A STRONG NWRLY LLVL WIND MAX ON SAT. VERTICAL
MIXING OF UP TO JUST AROUND 2 KFT AGL WILL EASILY TAP 25-25 KT
WINDS AND TRANSPORT THEM TO THE SFC IN FREQUENT GUSTS. THESE WINDS
MAY APPROACH ADVISORY CRITERIA ON OCCASION /ESP ACROSS THE EASTERN
THIRD OF THE CWA/...BUT VAST MAJORITY OF GUSTS WILL BE BELOW ADV
CRITERIA.
PLENTY OF STRATOCU WILL PERSIST ACROSS MOST OR ALL OF THE REGION
INTO THE MID AFTERNOON AS A WELL DEFINED 850-500 THERMAL TROUGH
CROSSES THE REGION. THE CLOUDS WILL GRADUALLY ERODE FROM SE TO NW
LATE IN THE AFTERNOON. HIGH TEMPS SATURDAY WILL VARY FROM THE
LOWER 20S ACROSS THE NRN AND WRN MTNS...TO THE UPPER 20S AND LOWER
30S ACROSS MUCH OF THE SUSQ VALLEY...BUT FEEL COLDER WITH THE
BREEZY CONDITIONS.
GRADUALLY DIMINISHING WINDS AND CLEARING SKIES WILL FOLLOW FOR
SAT NIGHT AS HIGH PRESSURE BUILDS EAST OVER THE STATE. MINS
SATURDAY NIGHT WILL BE A TAD BELOW GUIDANCE VALUES BASED ON PRIME
CONDITIONS FOR RADIATIONAL COOLING...IN THE FORM OF THE FRESH SNOW
COVER...LIGHT WIND...AND MAINLY CLEAR SKIES. TEMPS LATE SAT
NIGHT COULD DIP TO NEAR ZERO THROUGHOUT THE PERENNIAL COLD SPOTS
OVER THE NRN MTNS...AND IN THE TEENS ACROSS THE SOUTHERN HALF OF
CWA.
SUNDAY WILL FEATURE SUNSHINE...MIXING WITH SOME MID AND HIGH CLOUDS
MOVING IN FROM THE WEST DURING THE AFTERNOON. THE VERY COLD START
AND GRADUAL INCREASE IN THE CLOUD COVER IN THE AFTERNOON WILL KEEP
TEMPS NEAR NORMAL /IN THE MID-UPPER 30S/ THROUGHOUT THE CENTRAL AND
ERN ZONES. INCREASING SOUTHERLY FLOW IN THE AFTERNOON ACROSS THE
WESTERN HIGH TERRAIN WILL ALLOW FOR MAXS REACHING THE U30S TO AROUND
40F...OR 5-8F ABOVE NORMAL.
LITTLE SPREAD AMONG MED RANGE MDL GUIDANCE THRU EARLY NEXT
WEEK...ALL OF WHICH TRACKS NEXT LOW PRES SYS WEST AND JUST NORTH OF
PA LATE SUN NIGHT INTO MONDAY. DEPENDING ON TIMING...AND GIVEN THE
MARGINAL LLVL TEMP PROFILE...ANY LIGHT PRECIP ARRIVING EARLY
MONDAY MORNING COULD BE IN THE FORM OF FZRA. SFC TEMPS IN THE 20S TO
LOWER 30S WILL BE COLD ENOUGH FOR ICY CONDS EARLY MONDAY /ESP IF
PRECIP REACHES THE NORTHEAST PORTION OF CWA BETWEEN 06-12Z/ BEFORE
A CHANGEOVER TO PLAIN RAIN FROM SW TO NE BY 14-16Z.
SLIGHTLY COOLER AIR WILL MOVE BACK INTO THE REGION FOR TUESDAY
AND WEDNESDAY WITH SCATTERED LIGHT RAIN/SNOW SHOWERS ACROSS MAINLY
THE NW MTNS.
MINOR HEIGHT/THICKNESS RISES IN THE WAKE OF A HIGH PRESSURE RIDGE
LATER IN THE WEEK WILL LIKELY BE FOLLOWED BY A RATHER POTENT NRN
STREAM SHORTWAVE/CLIPPER TYPE SYSTEM FOR FRIDAY INTO SATURDAY WITH A
CHANCE OF SNOW SHOWERS.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
BACK EDGE OF THE STEADY MODERATE SNOW JUST EAST OF THE OFFICE.
WHILE THIS AREA IS SEPERATE FROM THE PCPN WITH THE COASTAL STORM...
STILL EXPECT THIS BACK EDGE TO SLOW THIS EVENING. FAR WESTERN
AREAS LIKE JST AND BFD SEEING SOME LIGHTER SNOW...AS WINDS ARE
NOW SHIFTING TO THE NW THERE. MAIN ISSUE WILL BE THE GUSTY WINDS
LATER THIS EVENING...AS THE COASTAL LOW BECOMES A MAJOR STORM
SYSTEM OFF THE COAST. SOME CHANGES MADE TO 21Z TAFS.
GUST WNW WINDS WITH SOME GUSTS TO 35 KTS POSSIBLE LATER TONIGHT.
MVFR CIGS AND SCT -SHSN PREVAIL ACROSS WESTERN AND NORTHERN
SECTIONS SATURDAY WITH VFR TO LCL MVFR CIGS CENTRAL AND SOUTH
CENTRAL. BECOMING MAINLY VFR EAST.
OUTLOOK...
SUN...VFR NO SIG WX.
MON...AM WINTRY MIX TO RAIN. FROPA. -SHSN WEST LATE.
TUE...MAINLY VFR...MVFR -SHSN PSBL NW.
WED...ANOTHER WINTER STORM POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM EST SATURDAY FOR PAZ037-042-
053-058.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...DEVOIR
LONG TERM...RXR
AVIATION...DEVOIR/MARTIN/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
710 AM EST FRI FEB 8 2013
.SYNOPSIS...
TWO AREAS OF LOW PRESSURE IN THE UPPER OHIO VALLEY AND ALONG THE
CAROLINA COAST WILL MERGE INTO A DEEP COASTAL STORM LATER TODAY.
THIS STORM WILL RAPIDLY INTENSIFY AS IT LIFTS NORTHEAST OFFSHORE
THE MID-ATLANTIC AND NEW ENGLAND COASTS. HIGH PRESSURE WILL BUILD
INTO THE AREA BEHIND THE STORM LATER SATURDAY INTO SUNDAY. A
FRONTAL SYSTEM MOVING EAST FROM THE MIDWEST SHOULD BRING ANOTHER
PERIOD OF MIXED PRECIPITATION ON MONDAY.
&&
.NEAR TERM /UNTIL NOON TODAY/...
12Z UPDATE...
RADAR AND OBS INDICATE THE NRN EDGE OF THE PCPN SHIELD WORKING NWD
INTO THE LWR SUSQ VLY HAS MADE IT TO RT30 IN LANCASTER CO. SFC
TEMPS AND LLVL WET BULBS REMAIN VERY MARGINAL AND KLNS RECENTLY
REPORTED PLAIN RAIN. THEREFORE ADJUSTED WX GRIDS AND POPS OVR THE
SERN ZONES THRU MID-MORNING. VERY COMPLEX AND DIFFICULT FCST EARLY
ON TDY...BUT AS BETTER FORCING ARRIVES LATER EXPECT CONDS TO GO
DOWNHILL.
PREVIOUS DISCUSSION...
LATEST RUC SFC ANALYSIS SHOWS TWO AREAS OF LOW PRESSURE NEAR
CLEVELAND OH AND CAPE HATTERAS NC. THE COMPLEX INTERACTION OF
THESE SFC LOWS WILL BEGIN TO TAKE PLACE THROUGH THE MORNING
HOURS...WITH LG SCALE HT FALLS AND LLVL THETA-E ADV/ISENT LIFT
AIDING IN BLOSSOMING/EXPANDING PRECIP OVER THE AREA.
FIRST AREA OF CONCERN IS NRN EDGE OF PRECIP SHIELD SLOWLY SHIFTING
NWWD FROM THE I-95 CORRIDOR. HI-RES MDLS AND RADAR TRENDS SUGGEST
THIS AREA OF PCPN COULD REACH AS FAR NW AS THE I-81 CORRIDOR BY
MID MORNING. LOCATIONS ALONG AND S OF RT 30 WILL LKLY SEE THE PCPN
ARRIVE BY 12-13Z. TEMPERATURE PROFILES REMAIN MARGINAL WITH SFC-
850MB WET BULBS HOVERING A DEGREE OR TWO EITHER SIDE OF 0C.
THEREFORE EXPECT A MIXTURE OF WINTRY PTYPES OVR PTNS OF THE LWR
SUSQ VLY THIS MORNING...WITH EVEN SOME PLAIN RAIN NEAR THE MD LINE.
WARM AIR STREAMING INTO WINDWARD SIDE OF THE ALLEGHENY FRONT
AHEAD OF THE OH VLY SYS SHOULD ALLOW FOR MAINLY FREEZING RAIN OR
SNOW PTYPES...WITH SNOW THE RESULT OF WET BULB/EVAP COOLING
EFFECTS. EXPECT LITTLE TO NO PCPN TO FALL THIS MORNING OVR THE
N-CENTRAL MTNS AND SRN POCONOS/ENDLESS MTN REGION N/E OF IPT.
TEMPS WILL BE IN THE UPPER 20S AND LOW 30S...BUT MAY FALL WITH THE
ONSET OF PCPN.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM SATURDAY/...
NRN STREAM SHRTWV WILL AMPLIFY AS IT PIVOTS EWD ACRS THE LWR GRT
LKS...EVENTUALLY TAKING ON A SLGT NEGATIVE TILT AS IT MERGES WITH
SRN STREAM SHRTWV/JET SYSTEM ALONG THE MID-ATLC COAST. THE RESULT
WILL BE EC CYCLOGENESIS WITH RAPID INTENSIFICATION OF THE NEW
PRIMARY COASTAL LOW EXPECTED AS IT LIFTS NEWD OFFSHORE THE MID
ATLC AND NEW ENGLAND COASTS THROUGH TNT.
THERE ARE STILL SOME MINOR TRACK AND/OR TIMING DIFFS IN HANDLING
THE EVOLUTION OF THE SIGNIFICANTLY DEEPENING STORM. FROM
A SFC LOW TRACK STANDPOINT..THE LATEST GFS APPEARS TO BE AN ERN
OUTLIER AND THE NAM A WRN OUTLIER..WITH ALL OF THE NON-NCEP
GUIDANCE MORE CLOSELY CLUSTERED IN BTWN THESE "OUTLIER" SOLNS.
OVERALL DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE PREVIOUS FCST.
BASED ON THE PROJECTED SNFL AMTS...THE CURRENT CONFIGURATION OF
WINTER STORM WARNINGS AND ADVISORIES STILL LOOKS IN PRETTY GOOD
SHAPE.
THE MAIN TIMEFRAME FOR SNOW WILL BE THIS AFTERNOON INTO EARLY
TONIGHT. STG HT FALLS/LOW-MID LVL FGEN ASSOCD WITH THE NRN STREAM
WAVE WILL SUPPORT A PERIOD OF MOD TO HVY SNOW ACRS N-CENTRAL PA
BTWN 18-00Z. COINCIDING WITH THE MERGER OF WAVES...A DEFORMATION
AXIS SHOULD SET UP OVR E-CENTRAL AND NERN PA ON THE WRN EDGE OF
INTENSE 850MB JET PIVOTING NWD ALONG THE SRN NEW ENGLAND COAST.
THE WINTER STORM WARNINGS CONTINUE WITH A FCST STORM TOTAL
SNOWFALL OF 4 TO 8 INCHES. THE HIGHEST AMTS ARE LKLY TO OCCUR TO
THE NORTH/EAST OF IPT...WHERE MDLS SUGGESTS THE WRAP-AROUND SNOW
AXIS MAY PERSIST INTO LATE TNT.
N-NW WINDS WILL INCREASE LATE TONIGHT INTO EARLY SATURDAY ON THE
BACKSIDE OF THE DEEP CYCLONE.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
THE TIGHT P-GRADIENT IN THE WAKE OF THE DEPARTING INTENSE LOW WILL
HELP TO CREATE A STRONG NWRLY LLVL WIND MAX. VERTICAL MIXING OF UP
TO JUST AROUND 2 KFT AGL WILL EASILY TAP 35-40 KT WINDS AND
TRANSPORT THEM TO THE SFC IN FREQUENT GUSTS. THESE WINDS WILL
APPROACH ADVISORY CRITERIA /ESP ACROSS THE EASTERN THIRD OF THE
CWA/...BUT WITH THE CURRENT FLAGS FOR SNOW BLANKETING THE REGION
TODAY...WILL DEFER THIS LESSER CONCERN TO LATER SHIFTS.
PLENTY OF STRATO CU WILL PERSIST ACROSS MOST OR ALL OF THE REGION
INTO THE MID AFTERNOON AS A WELL DEFINED 850-500 THERMAL TROUGH
CROSSES THE REGION. THE CLOUDS WILL GRADUALLY ERODE FROM SE TO NW
LATE IN THE AFTERNOON.
HIGH TEMPS SATURDAY WILL VARY FROM THE LOWER 20S ACROSS THE NRN AND
WRN MTNS...TO THE UPPER 20S AND LOWER 30S ACROSS MUCH OF THE SUSQ
VALLEY.
GRADUALLY DIMINISHING WINDS AND CLEARING SKIES WILL FOLLOW FOR
SAT NIGHT AS HIGH PRESSURE BUILDS EAST OVER THE STATE. MINS
SATURDAY NIGHT WILL BE A TAD BELOW GUIDANCE VALUES BASED ON PRIME
CONDITIONS FOR RADIATIONAL COOLING...IN THE FORM OF THE FRESH SNOW
COVER...LIGHT WIND...AND MAINLY CLEAR SKIES.
TEMPS LATE SAT NIGHT COULD DIP TO NEAR ZERO THROUGHOUT THE PERENNIAL
COLD SPOTS OVER THE NRN MTNS.
SUNDAY WILL FEATURE SUNSHINE...MIXING WITH SOME MID AND HIGH CLOUDS
MOVING IN FROM THE WEST DURING THE AFTERNOON. THE VERY COLD START
AND GRADUAL INCREASE IN THE CLOUD COVER IN THE AFTERNOON WILL KEEP
TEMPS NEAR NORMAL /IN THE MID-UPPER 30S/ THROUGHOUT THE CENTRAL AND
ERN ZONES. INCREASING SOUTHERLY FLOW IN THE AFTERNOON ACROSS THE
WESTERN HIGH TERRAIN WILL ALLOW FOR MAXS REACHING THE U30S TO AROUND
40F...OR 5-8F ABOVE NORMAL.
LITTLE SPREAD AMONG MED RANGE MDL GUIDANCE THRU EARLY NEXT
WEEK...ALL OF WHICH TRACKS NEXT LOW PRES SYS WEST AND JUST NORTH OF
PA LATE SUN NIGHT INTO MONDAY. DEPENDING ON TIMING...AND GIVEN THE
MARGINAL LLVL TEMP PROFILE...ANY LIGHT PRECIP ARRIVING EARLY
MONDAY MORNING COULD BE IN THE FORM OF FZRA. SFC TEMPS IN THE 20S TO
LOWER 30S WILL BE COLD ENOUGH FOR ICY CONDS EARLY MONDAY BEFORE A
CHANGE TO PLAIN RAIN BY 14-15Z.
MODERATE RAINFALL AMOUNTS OF SEVERAL TENTHS OF AN INCH WILL COMBINE
WITH SOME SNOWMELT TO CAUSE SOME MINOR TO MODERATE RISES ON AREA
STREAMS AND CREEKS INTO THE MIDWEEK.
SLIGHTLY COOLER AIR WILL MOVE BACK INTO THE REGION FOR TUESDAY AND
WEDNESDAY WITH SCATTERED LIGHT RAIN/SNOW SHOWERS ACROSS MAINLY THE
NW MTNS.
MINOR HEIGHT/THICKNESS RISES IN THE WAKE OF A HIGH PRESSURE RIDGE
LATER IN THE WEEK WILL LIKELY BE FOLLOWED BY A RATHER POTENT NRN
STREAM SHORTWAVE/CLIPPER TYPE SYSTEM FOR FRIDAY INTO SATURDAY WITH A
CHANCE OF SNOW SHOWERS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
08/12Z-09/12Z...
WRN TAFS IN ZOB SECTOR ARE DOWN TO IFR...WHILE CIGS AT ERN TAFS
IN ZNY DOMAIN ARE RUNNING 1000-2000FT AGL. EXPECT LITTLE TO NO
IMPROVEMENT THRU THE AM HOURS. CONFIDENCE REMAINS LOW REGARDING
THE EVOLUTION OF PCPN/TYPE TRENDS IN THE NEAR TERM...BUT HIGHER
CONFIDENCE IN SNOW DEVELOPING THIS AFTN.
LOW PRESSURE MOVING EWD THRU THE UPPER OH VLY EARLY THIS MORNING
WILL MERGE WITH ANOTHER LOW MOVING UP THE CAROLINA COAST TO FORM A
MAJOR WINTER STORM OFFSHORE THE MID-ATLANTIC COAST BY LATE THIS
AFTERNOON. THE STORM WILL SLOW DOWN AS IT CONTINUES TO STRENGTHEN
OFF THE NEW ENGLAND COAST...REACHING PEAK INTENSITY JUST EAST OF
CAPE COD EARLY SATURDAY MORNING. AVIATION IMPACTS FROM THIS STORM
WILL LAST INTO SATURDAY AFTERNOON BEFORE HIGH PRESSURE ARRIVES
LATER SATURDAY INTO SUNDAY.
COLD AIR DAMMING EAST OF THE ALLEGHENY FRONT WILL SUPPORT LOW MVFR
AND IFR CIGS THRU MUCH OF THE PERIOD. CENTRAL PA AIRSPACE WILL BE
IN-BTWN THE TWO MERGING LOW PRESSURE SYSTEMS...THEREFORE MAKING
ONSET AND EARLY EVOLUTION OF PCPN/TYPES SOMEWHAT DIFFICULT AND
CHALLENGING. ALTHOUGH CONFIDENCE IN THE EXACT TIMING AND PTYPES
ARE RELATIVELY LOW...IN GENERAL EXPECT POOR FLYING CONDS TO
PERSIST INTO TONIGHT. TRIED TO SHOW TRANSITION FROM MIXED PCPN TO
ALL SNOW BY THE AFTN. IN ADDITION TO LOW VIS/CIGS AND MIXED WINTRY
PCPN...EXPECT WINDS TO SHIFT FROM E/SE TO WNW AND INCREASE TONIGHT
AS THE COASTAL STORM BOMBS-OUT EAST OF LONG ISLAND.
OUTLOOK...
SAT...MVFR/IFR EARLY BCMG MVFR/VFR. STRONG N-NW WINDS.
SUN...VFR NO SIG WX.
MON...AM WINTRY MIX TO RAIN. FROPA. -SHSN WEST LATE.
TUE...MAINLY VFR...MVFR -SHSN PSBL NW.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 AM EST SATURDAY FOR PAZ004>006-
037-041-042-046-051>053-058.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR PAZ010>012-
017>019-024>028-033>036-045-049-050-056-057-059-063>066.
&&
$$
SYNOPSIS...LAMBERT/STEINBUGL
NEAR TERM...LAMBERT/STEINBUGL
SHORT TERM...LAMBERT
LONG TERM...LAMBERT
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
617 AM EST FRI FEB 8 2013
.SYNOPSIS...
TWO AREAS OF LOW PRESSURE IN THE UPPER OHIO VALLEY AND ALONG THE
CAROLINA COAST WILL MERGE INTO A DEEP COASTAL STORM LATER TODAY.
THIS STORM WILL RAPIDLY INTENSIFY AS IT LIFTS NORTHEAST OFFSHORE
THE MID-ATLANTIC AND NEW ENGLAND COASTS. HIGH PRESSURE WILL BUILD
INTO THE AREA BEHIND THE STORM LATER SATURDAY INTO SUNDAY. A
FRONTAL SYSTEM MOVING EAST FROM THE MIDWEST SHOULD BRING ANOTHER
PERIOD OF MIXED PRECIPITATION ON MONDAY.
&&
.NEAR TERM /UNTIL NOON TODAY/...
LATEST RUC SFC ANALYSIS SHOWS TWO AREAS OF LOW PRESSURE NEAR
CLEVELAND OH AND CAPE HATTERAS NC. THE COMPLEX INTERACTION OF
THESE SFC LOWS WILL BEGIN TO TAKE PLACE THROUGH THE MORNING
HOURS...WITH LG SCALE HT FALLS AND LLVL THETA-E ADV/ISENT LIFT
AIDING IN BLOSSOMING/EXPANDING PRECIP OVER THE AREA.
FIRST AREA OF CONCERN IS NRN EDGE OF PRECIP SHIELD SLOWLY SHIFTING
NWWD FROM THE I-95 CORRIDOR. HI-RES MDLS AND RADAR TRENDS SUGGEST
THIS AREA OF PCPN COULD REACH AS FAR NW AS THE I-81 CORRIDOR BY
MID MORNING. LOCATIONS ALONG AND S OF RT 30 WILL LKLY SEE THE PCPN
ARRIVE BY 12-13Z. TEMPERATURE PROFILES REMAIN MARGINAL WITH SFC-
850MB WET BULBS HOVERING A DEGREE OR TWO EITHER SIDE OF 0C.
THEREFORE EXPECT A MIXTURE OF WINTRY PTYPES OVR PTNS OF THE LWR
SUSQ VLY THIS MORNING...WITH EVEN SOME PLAIN RAIN NEAR THE MD LINE.
WARM AIR STREAMING INTO WINDWARD SIDE OF THE ALLEGHENY FRONT
AHEAD OF THE OH VLY SYS SHOULD ALLOW FOR MAINLY FREEZING RAIN OR
SNOW PTYPES...WITH SNOW THE RESULT OF WET BULB/EVAP COOLING
EFFECTS. EXPECT LITTLE TO NO PCPN TO FALL THIS MORNING OVR THE
N-CENTRAL MTNS AND SRN POCONOS/ENDLESS MTN REGION N/E OF IPT.
TEMPS WILL BE IN THE UPPER 20S AND LOW 30S...BUT MAY FALL WITH THE
ONSET OF PCPN.
&&
.SHORT TERM /NOON TODAY THROUGH TONIGHT/...
NRN STREAM SHRTWV WILL AMPLIFY AS IT PIVOTS EWD ACRS THE LWR GRT
LKS...EVENTUALLY TAKING ON A SLGT NEGATIVE TILT AS IT MERGES WITH
SRN STREAM SHRTWV/JET SYSTEM ALONG THE MID-ATLC COAST. THE RESULT
WILL BE EC CYCLOGENESIS WITH RAPID INTENSIFICATION OF THE NEW
PRIMARY COASTAL LOW EXPECTED AS IT LIFTS NEWD OFFSHORE THE MID
ATLC AND NEW ENGLAND COASTS THROUGH TNT.
THERE ARE STILL SOME MINOR TRACK AND/OR TIMING DIFFS IN HANDLING
THE EVOLUTION OF THE SIGNIFICANTLY DEEPENING STORM. FROM
A SFC LOW TRACK STANDPOINT..THE LATEST GFS APPEARS TO BE AN ERN
OUTLIER AND THE NAM A WRN OUTLIER..WITH ALL OF THE NON-NCEP
GUIDANCE MORE CLOSELY CLUSTERED IN BTWN THESE "OUTLIER" SOLNS.
OVERALL DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE PREVIOUS FCST.
BASED ON THE PROJECTED SNFL AMTS...THE CURRENT CONFIGURATION OF
WINTER STORM WARNINGS AND ADVISORIES STILL LOOKS IN PRETTY GOOD
SHAPE.
THE MAIN TIMEFRAME FOR SNOW WILL BE THIS AFTERNOON INTO EARLY
TONIGHT. STG HT FALLS/LOW-MID LVL FGEN ASSOCD WITH THE NRN STREAM
WAVE WILL SUPPORT A PERIOD OF MOD TO HVY SNOW ACRS N-CENTRAL PA
BTWN 18-00Z. COINCIDING WITH THE MERGER OF WAVES...A DEFORMATION
AXIS SHOULD SET UP OVR E-CENTRAL AND NERN PA ON THE WRN EDGE OF
INTENSE 850MB JET PIVOTING NWD ALONG THE SRN NEW ENGLAND COAST.
THE WINTER STORM WARNINGS CONTINUE WITH A FCST STORM TOTAL
SNOWFALL OF 4 TO 8 INCHES. THE HIGHEST AMTS ARE LKLY TO OCCUR TO
THE NORTH/EAST OF IPT...WHERE MDLS SUGGESTS THE WRAP-AROUND SNOW
AXIS MAY PERSIST INTO LATE TNT.
N-NW WINDS WILL INCREASE LATE TONIGHT INTO EARLY SATURDAY ON THE
BACKSIDE OF THE DEEP CYCLONE.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
THE TIGHT P-GRADIENT IN THE WAKE OF THE DEPARTING INTENSE LOW WILL
HELP TO CREATE A STRONG NWRLY LLVL WIND MAX. VERTICAL MIXING OF UP
TO JUST AROUND 2 KFT AGL WILL EASILY TAP 35-40 KT WINDS AND
TRANSPORT THEM TO THE SFC IN FREQUENT GUSTS. THESE WINDS WILL
APPROACH ADVISORY CRITERIA /ESP ACROSS THE EASTERN THIRD OF THE
CWA/...BUT WITH THE CURRENT FLAGS FOR SNOW BLANKETING THE REGION
TODAY...WILL DEFER THIS LESSER CONCERN TO LATER SHIFTS.
PLENTY OF STRATO CU WILL PERSIST ACROSS MOST OR ALL OF THE REGION
INTO THE MID AFTERNOON AS A WELL DEFINED 850-500 THERMAL TROUGH
CROSSES THE REGION. THE CLOUDS WILL GRADUALLY ERODE FROM SE TO NW
LATE IN THE AFTERNOON.
HIGH TEMPS SATURDAY WILL VARY FROM THE LOWER 20S ACROSS THE NRN AND
WRN MTNS...TO THE UPPER 20S AND LOWER 30S ACROSS MUCH OF THE SUSQ
VALLEY.
GRADUALLY DIMINISHING WINDS AND CLEARING SKIES WILL FOLLOW FOR
SAT NIGHT AS HIGH PRESSURE BUILDS EAST OVER THE STATE. MINS
SATURDAY NIGHT WILL BE A TAD BELOW GUIDANCE VALUES BASED ON PRIME
CONDITIONS FOR RADIATIONAL COOLING...IN THE FORM OF THE FRESH SNOW
COVER...LIGHT WIND...AND MAINLY CLEAR SKIES.
TEMPS LATE SAT NIGHT COULD DIP TO NEAR ZERO THROUGHOUT THE PERENNIAL
COLD SPOTS OVER THE NRN MTNS.
SUNDAY WILL FEATURE SUNSHINE...MIXING WITH SOME MID AND HIGH CLOUDS
MOVING IN FROM THE WEST DURING THE AFTERNOON. THE VERY COLD START
AND GRADUAL INCREASE IN THE CLOUD COVER IN THE AFTERNOON WILL KEEP
TEMPS NEAR NORMAL /IN THE MID-UPPER 30S/ THROUGHOUT THE CENTRAL AND
ERN ZONES. INCREASING SOUTHERLY FLOW IN THE AFTERNOON ACROSS THE
WESTERN HIGH TERRAIN WILL ALLOW FOR MAXS REACHING THE U30S TO AROUND
40F...OR 5-8F ABOVE NORMAL.
LITTLE SPREAD AMONG MED RANGE MDL GUIDANCE THRU EARLY NEXT
WEEK...ALL OF WHICH TRACKS NEXT LOW PRES SYS WEST AND JUST NORTH OF
PA LATE SUN NIGHT INTO MONDAY. DEPENDING ON TIMING...AND GIVEN THE
MARGINAL LLVL TEMP PROFILE...ANY LIGHT PRECIP ARRIVING EARLY
MONDAY MORNING COULD BE IN THE FORM OF FZRA. SFC TEMPS IN THE 20S TO
LOWER 30S WILL BE COLD ENOUGH FOR ICY CONDS EARLY MONDAY BEFORE A
CHANGE TO PLAIN RAIN BY 14-15Z.
MODERATE RAINFALL AMOUNTS OF SEVERAL TENTHS OF AN INCH WILL COMBINE
WITH SOME SNOWMELT TO CAUSE SOME MINOR TO MODERATE RISES ON AREA
STREAMS AND CREEKS INTO THE MIDWEEK.
SLIGHTLY COOLER AIR WILL MOVE BACK INTO THE REGION FOR TUESDAY AND
WEDNESDAY WITH SCATTERED LIGHT RAIN/SNOW SHOWERS ACROSS MAINLY THE
NW MTNS.
MINOR HEIGHT/THICKNESS RISES IN THE WAKE OF A HIGH PRESSURE RIDGE
LATER IN THE WEEK WILL LIKELY BE FOLLOWED BY A RATHER POTENT NRN
STREAM SHORTWAVE/CLIPPER TYPE SYSTEM FOR FRIDAY INTO SATURDAY WITH A
CHANCE OF SNOW SHOWERS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
08/06Z-09/06Z...
LOW PRESSURE MOVING EWD THRU THE UPPER OH VLY EARLY THIS MORNING
WILL MERGE WITH ANOTHER LOW MOVING UP THE CAROLINA COAST TO FORM A
MAJOR WINTER STORM OFFSHORE THE MID-ATLANTIC COAST BY LATE THIS
AFTERNOON. THE STORM WILL SLOW DOWN AS IT CONTINUES TO STRENGTHEN
OFF THE NEW ENGLAND COAST...REACHING PEAK INTENSITY JUST EAST OF
CAPE COD EARLY SATURDAY MORNING. AVIATION IMPACTS FROM THIS STORM
WILL LAST INTO SATURDAY AFTERNOON BEFORE HIGH PRESSURE ARRIVES
LATER SATURDAY INTO SUNDAY.
COLD AIR DAMMING EAST OF THE ALLEGHENY FRONT WILL SUPPORT LOW MVFR
AND IFR CIGS THRU MUCH OF THE PERIOD. CENTRAL PA AIRSPACE WILL BE
IN-BTWN THE TWO MERGING LOW PRESSURE SYSTEMS...THEREFORE MAKING
ONSET AND EARLY EVOLUTION OF PCPN/TYPES SOMEWHAT DIFFICULT AND
CHALLENGING. ALTHOUGH CONFIDENCE IN THE EXACT TIMING AND PTYPES
ARE RELATIVELY LOW...IN GENERAL EXPECT POOR FLYING CONDS TO
PERSIST INTO TONIGHT. TRIED TO SHOW TRANSITION FROM MIXED PCPN TO
ALL SNOW BY THE AFTN. IN ADDITION TO LOW VIS/CIGS AND MIXED WINTRY
PCPN...EXPECT WINDS TO SHIFT FROM E/SE TO WNW AND INCREASE TONIGHT
AS THE COASTAL STORM BOMBS-OUT EAST OF LONG ISLAND.
OUTLOOK...
SAT...MVFR/IFR EARLY BCMG MVFR/VFR. STRONG N-NW WINDS.
SUN...VFR NO SIG WX.
MON...AM WINTRY MIX TO RAIN. FROPA. -SHSN WEST LATE.
TUE...MAINLY VFR...MVFR -SHSN PSBL NW.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 AM EST SATURDAY FOR PAZ004>006-
037-041-042-046-051>053-058.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR PAZ010>012-
017>019-024>028-033>036-045-049-050-056-057-059-063>066.
&&
$$
SYNOPSIS...LAMBERT/STEINBUGL
NEAR TERM...LAMBERT/STEINBUGL
SHORT TERM...LAMBERT
LONG TERM...LAMBERT
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
350 PM CST FRI FEB 8 2013
.DISCUSSION.../ISSUED AT 350 PM CST/
STRATUS FIELD MELTING AWAY ACROSS PORTIONS OF THE FORECAST AREA
WHILE IN OTHER AREAS IT IS HOLDING STEADFAST. RAP SUGGESTS THAT
STRATUS WILL BECOME MORE WIDESPREAD ACROSS THE AREA THROUGH THE
EVENING HOURS...AND EVEN SUGGESTS THE POTENTIAL FOR FOG DEVELOPING
ALONG AND EAST OF THE JAMES RIVER VALLEY. HAVE ADDED MENTION OF FOG
ALONG AND EAST OF THE JAMES RIVER VALLEY...BUT HAVE NOT GONE AS
BULLISH AS HE RAP WHICH WOULD SUGGEST THE POTENTIAL FOR A DENSE FOG
ADVISORY.
QUESTIONS STILL REMAIN AS TO HOW LONG THE STRATUS WILL LINGER DURING
THE DAYLIGHT HOURS ON SATURDAY. OVERALL...SYNOPTIC PATTERN SUGGESTS
WARM FRONT APPROACHING FROM THE SOUTH WITH 925 HPA TEMPERATURE
WARMING 2-3 DEGREES C IN THE 18 TO 00Z TIME FRAME. THIS SHOULD LEAD
TO A FAIR AMOUNT OF LATE DAY HEATING...WITH LATE AFTERNOON/EARLY
EVENING HIGHS. HAVE OUTSIDE CHANCE OF A SHOWER DEVELOPING IN THE
LATE AFTERNOON HOURS ACROSS CENTRAL SOUTH DAKOTA...BUT MAIN
PRECIPITATION SHOULD HOLD OFF THROUGH 00Z SUNDAY.
SATURDAY NIGHT WILL START TO BE A TRANSITION PERIOD TO WEATHER
ACROSS THE AREA AS STRONG JET STARTS TO LIFT OUT OF THE SOUTHERN
ROCKIES AND TOWARD THE CENTRAL PLAINS. LOW LEVEL THERMAL BOUNDARY
SHOULD SHARPEN ALONG DEVELOPING INVERTED TROUGH. SURGE OF MOISTURE
WILL PUSH INTO THE SYSTEM AS LOW LEVEL JET INCREASES...AND GOOD
DYNAMIC NUDGE WILL DEVELOP AS DRY SLOT PUSHES NORTH THROUGH
NEBRASKA. AS THIS FIRST LOBE LIFTS NORTHEASTWARD THROUGH THE PLAINS
DURING THE EVENING...SOME ELEVATED INSTABILITY INDICATED...AND WHILE
SURFACE TEMPS SHOULD BE SAFELY ABOVE FREEZING...MAY END UP WITH SOME
ICE PELLETS WITH SHOWERY PRECIPITATION. WILL GET SECONDARY AREA WITH
MAIN DIV Q/PV ADVECTION LATER IN NIGHT FROM SOUTHWEST...WHICH SHOULD
MAKE FOR MORE WIDESPREAD SHOWERS...BECOMING MORE STRATIFORM BACK IN
DEFORMATION THROUGH WESTERN CWA. WOULD NOT BE SURPRISED TO FIND A
FEW RUMBLES OF THUNDER BY LATE NIGHT GIVEN THE 800 HPA LI NEAR
ZERO. THIS COULD PRESENT A SMALL WILD CARD TOWARD TYPE IF DEEPER
CONVECTION BECOMES ESTABLISHED. HOWEVER...FOR THE MOST PART...HARD
TO PICTURE A GREAT DEAL OF SNOW WITH MOST OF THE PRECIPITATION ON
SATURDAY NIGHT...WITH MORE INTENSITY IN THE FAR WEST AND SOME
SLIGHTLY COOLER/DRIER AIR TO THE NORTH AIDING IN MIX/CHANGE
POTENTIAL. INVERTED TROUGH SHOULD BE FAIRLY CLOSE TO THE JAMES
VALLEY BY DAYBREAK SUNDAY...PERHAPS A BIT WESTWARD...WITH BULK OF
ANY FROZEN PRECIPITATION FORCED ALONG AND BEHIND FEATURE.
MODEL TRENDS ARE STARTING TO GRAVITATE TOWARD A SOLUTION CENTERED
AROUND AN ECMWF/GFS TRACK TO WAVE AS IT PUSHES OUT INTO THE PLAINS
AND ACROSS THE AREA ON SUNDAY. NAM CONTINUES TO BE THE NORTHERN AND
CANADIAN GLOBAL THE SOUTHERN OUTLIERS. FOLLOWING ALONG THE GENERAL
GUIDANCE...WAVE WILL PUSH VERY CLOSE TO THE MIDDLE OF THE CWA...
PERHAPS A BIT TO THE EAST...COLLAPSING THE INVERTED TROUGH CLOSER TO
I29 BY MIDDAY. FAIRLY SOLID LOOK TO DRY SLOT PUSHING NORTHWARD
THROUGH EASTERN CWA AHEAD OF THIS FEATURE...AND TRENDED BACK POPS
TOWARD SCATTERED FOR A TIME DURING THE MORNING...WITH PERHAPS A
LITTLE THUNDER AS WELL. WIDESPREAD PRECIPITATION BACK TO THE WEST
AS TROWAL BECOMES FAIRLY WELL ESTABLISHED BY EARLY SUNDAY...
WITH LIFT INITIALLY INDICATED ON THE NORTHWEST FLANK. HOWEVER...
FRONTOGENETIC FORCING GRADUALLY INCREASES ON THE SOUTHEAST FLANK OF
THE TROWAL AS SUNDAY GOES ON...WITH LOW EPV SUPPORTING AN ENHANCING
FRONTAL CIRCULATION...THE FOCUS FOR THE SOUTHEASTWARD COLLAPSING
SNOW BAND ON LATER SUNDAY AFTERNOON AND EVENING. FAIRLY STRONG LIFT
IN THE DENDRITIC GROWTH ZONE INDICATED...BUT NOT TOO DEEP A LAYER...
AND EFFICIENCY MAY SUFFER A BIT FOR THAT. SNOW RATIO IN MAX BAND
FROM 12-16 TO 1. RESULTING 8-12 INCHES OF SNOWFALL EXPECTED OVER THE
NORTHWEST THIRD OR SO OF THE AREA WILL INTERACT WITH STRONG NORTH
TO NORTHWEST WINDS BEHIND THE INVERTED TROUGH AS SYSTEM WRAPS UP
LATER SUNDAY AND SUNDAY NIGHT. WITH 30-40 KNOTS OF 925 HPA
WIND...SHOULD EASILY SUPPORT THREAT OF BLIZZARD CONDITIONS.
SHARPENED UP WITH OVERALL SNOWFALL TOTALS ON THE SOUTHEAST SIDE OF
THE BAND...AND WILL LIKELY NEED FURTHER SHARPENING ONCE DETERMINATION
OF THE LONGER LINGERING TROWAL SNOWFALL CAN BE DETERMINED.
IN TERMS OF HEADLINE DECISIONS...FAIRLY OBVIOUS NEED TO DELAY THE
START TIME IN THE WESTERN GROUP BY AT LEAST 6H...WITH VERY LITTLE
SNOWFALL AND THE WIND LIKELY NOT MUCH OF AN ISSUE UNTIL WELL AFTER
06Z. CONSIDERED DELAYING START TO THE MORE EASTERN GROUP AS WELL FOR
SIMILAR REASONS...ESPECIALLY THE FAR EAST WHICH WILL NOT SEE
INVERTED TROUGH PASSAGE AND INCREASE IN WINDS UNTIL TOWARD EVENING
ON SUNDAY. DID SPLIT OFF THE FAR EASTERN AREAS AND DELAY START UNTIL
LATE AFTERNOON SUNDAY...AND ADDED IN A FEW COUNTIES BORDERING THE
EAST EDGE OF THE EXISTING WATCH...MAINLY WHERE SNOWFALL OF 3 TO 4
INCHES WOULD BE COMBINING WITH GUSTY NORTHWEST WINDS TO 25 TO
40 MPH. ALSO...GIVEN THE WINDS WHICH ARE LIKELY TO ONLY BE ON A SLOW
DOWNWARD TREND BY EARLY MONDAY...EXTENDED THE WATCH THROUGH MIDDAY
MONDAY...BUT WORST CONDITIONS ARE CERTAINLY TO BE EXPECTED FROM EAST
CENTRAL SD INTO NORTHERN PARTS OF SW MN BY MONDAY MORNING.
CHANGES TO THE TUE THROUGH FRIDAY TIME PERIOD LIMITED DUE TO
ATTENTION ON THE MUCH MORE SIGNIFICANT ISSUES OF THE SHORTER TERM.
CLIPPER SYSTEM WORKING SOUTHEAST WEDNESDAY NIGHT AND THURSDAY SHOULD
BE ACCOMPANIED BY A PERIOD OF SNOW SHOWERS...WITH AMPLIFICATION OF
SYSTEM DRAWING DOWN SOME MUCH COLDER AIR. MAY BE A LITTLE MORE MESSY
THAN CURRENTLY GIVING CREDIT FOR...WITH AMPLIFICATION STRENGTHENING
GRADIENT TO 35 TO 45 KNOTS AT 925 HPA BEHIND SYSTEM ON THURSDAY AND
THURSDAY EVENING. FOR THE TIME...INCREASED POPS A TOUCH OVER THE
INITIALIZATION SLIGHTS/LOW CHANCE. /CHAPMAN
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
MODELS CONTINUING TO STRUGGLE WITH LOW LYING STRATUS ACROSS THE
CENTRAL PORTIONS OF THE US. HAVE CONTINUED TO SIDE WITH RAP
SOUNDINGS WHICH CONTINUE TO SUGGEST LOW LEVEL SATURATION ALONG AND
EAST OF THE JAMES THROUGH AT LEAST 09Z SATURDAY. MAY SEE WESTERN
EDGE OF THE STRATUS APPROACH THE JAMES RIVER VALLEY IN THE LATE
AFTERNOON HOURS...BUT SHOULD FILL BACK IN FRIDAY EVENING. HAVE
THEREFORE LOWERED CONDITIONS THROUGH AT LEAST THE FIRST 18 HOURS OF
THE TAF PERIOD. ONLY WAY TO SHAKE THE STRATUS ON SATURDAY WOULD BE
THROUGH ADVECTION...THOUGH TIMING OF THIS IS VERY UNCERTAIN.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...BLIZZARD WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING FOR
MNZ071-072-097.
BLIZZARD WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING FOR
MNZ080-081-098.
NE...NONE.
SD...BLIZZARD WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING FOR
SDZ040-054>056-059>062-064-065-068.
BLIZZARD WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING FOR
SDZ066-067-069.
BLIZZARD WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY MORNING
FOR SDZ038-039-050-052-053-057-058-063.
&&
$$
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1113 AM CST FRI FEB 8 2013
.DISCUSSION...
FORECAST UPDATE FOCUSES ON CLOUD COVER ACROSS THE AREA. MODELS NOT
HANDLING WIDESPREAD STRATUS ACROSS THE UPPER MIDWEST EXTENDING FROM
NORTHERN EDGE OF FORECAST AREA TO SOUTHERN MISSOURI. WITH
REINFORCING SOUTHEAST FLOW IN THE LOWER LEVELS OF THE
ATMOSPHERE...WILL BE A STRUGGLE TO SHAKE THE CLOUD COVER. MAY SEE
CLOUDS TRY TO ERODE ACROSS SOUTH CENTRAL SOUTH DAKOTA...BUT IN
GENERAL...WILL BE DIFFICULT TO SHAKE THE STRATUS ALONG AND EAST OF
THE JAMES RIVER VALLEY. HAVE LOWERED FORECAST HIGHS TO A DEGREE OR
TWO TO ISOTHERMAL FROM 925 HPA.
HAVE INCREASED CLOUD COVER ACROSS THE AREA TONIGHT...BUT WILL LIKELY
HAVE TO MAKE SOME ADDITIONAL CHANGES WITH AFTERNOON PACKAGE.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
MODELS CONTINUING TO STRUGGLE WITH LOW LYING STRATUS ACROSS THE
CENTRAL PORTIONS OF THE US. HAVE CONTINUED TO SIDE WITH RAP
SOUNDINGS WHICH CONTINUE TO SUGGEST LOW LEVEL SATURATION ALONG AND
EAST OF THE JAMES THROUGH AT LEAST 09Z SATURDAY. HAVE THEREFORE
LOWERED CONDITIONS THROUGH AT LEAST THE FIRST 18 HOURS OF THE TAF
PERIOD. ONLY WAY TO SHAKE THE STRATUS ON SATURDAY WOULD BE THROUGH
ADVECTION...WHICH IS UNCLEAR AS TO WHETHER THAT WOULD OCCUR OR NOT.
&&
.PREV DISCUSSION.../ISSUED AT 444 AM CST/
MAIN CONCERN THE NEXT 24 HOURS IS THE STRATUS AND HOW FAST IT
DISSIPATES/ADVECTS OUT. NO MODEL EXCEPT THE RAP HAS A REAL HANDLE ON
THE STRATUS WITH NAM AND GFS ERODING STRATUS THIS MORNING WHILE RAP
KEEPS OVER MUCH OF THE AREA THROUGH 00Z. THEREFORE...GIVEN THICKNESS
AND WIDESPREAD NATURE OF STRATUS HAVE FOLLOWED THE RAP THROUGH 21Z
AND THEN USED NAM AND GFS 925 MB WINDS TO GIVE INDICATION OF WHEN
FLOW HAS ENOUGH WESTERLY COMPONENT TO ADVECT CLOUDS TO THE
NORTHEAST. THIS KEEP CLOUDS EAST OF THE JAMES ALL DAY WITH THE SW MN
AND NW IA LIKELY NOT CLEAR UNTIL WELL AFTER SUNSET. WITH CLOUDS MOST
OF THE DAY...TEMPERATURES WILL STRUGGLE TO RISE MUCH. BASICALLY WENT
ISOTHERMAL FROM 925 MB EAST OF THE JAMES WHICH KEEPS HIGHS FROM
UPPER 20S TO LOWER 30S. ALONG AND EAST OF THE JAMES...MORE SUNSHINE
IN THE AFTERNOON WILL ENHANCE MIXING AS WARMER AIR MOVES IN ALOFT.
SO HAVE HIGHS IN THE MID 30S AROUND HON AND MHE TO UPPER 40S IN
GREGORY COUNTY.
DESPITE CLEARING SKIES...INCREASING SOUTHEAST FLOW WILL KEEP
ATMOSPHERE FAIRLY WELL MIXED TONIGHT. EXPECT LOWS TO ONLY DROP 5
DEGREES OR SO EAST OF THE JAMES AS WARMER AIR MOVES IN ALOFT. WHERE
TEMPERATURES RISE WELL ABOVE FREEZING...EXPECT THEM TO FALL TOWARD
FREEZING OVERNIGHT BUT STILL FAIRLY MILD. EXPECT TO SEE CIRRUS
SLOWLY INCREASE THROUGH THE NIGHT AS STRONG UPPER LOW MOVES INTO THE
ROCKIES./SCHUMACHER
ATTENTION THEN TURNS TO A POTENTIAL BLIZZARD ACROSS THE NORTHERN
PLAINS SATURDAY NIGHT INTO SUNDAY NIGHT. MODELS IN FAIRLY GOOD
AGREEMENT...BUT SMALL DIFFERENCES EXIST...AND UNFORTUNATELY OUR CWA
IS SITUATED IN A LOCATION THAT ONLY SMALL SHIFTS IN THE STORM TRACK
WILL HAVE SIGNIFICANT IMPACTS ON WEATHER CONDITIONS. NAM/SREF ARE
NORTHERN OUTLIERS AND WERE NOT NOT USED IN THIS FORECAST DUE TO
UNREALISTIC LOOKING WAVE EVOLUTION. THE MODELS CONSIDERED WERE THUS
THE GFS/ECMWF/UKMET AND GEM. OF THIS GROUP...THE GFS IS THE FURTHEST
NORTH...THE GEM/UKMET THE FURTHEST SOUTH AND THE ECMWF IN BETWEEN.
THE 4 MODELS HAVE BEEN VERY CONSISTENT IN THEIR OWN SOLUTIONS. THE
GEM IS STRONGEST AND QUICKEST WITH THE NORTHERN STREAM WAVE...WHICH
KEEPS THE SURFACE LOW FURTHEST SOUTH. IT IS THUS THE COLDEST
SOLUTION AND WOULD GIVE MORE AREAS SNOW. THE 0Z GFS AND ECMWF ARE
VERY SIMILAR WITH THEIR UPPER AIR PATTERNS...BUT DIFFER WITH REGARDS
TO SURFACE LOW TRACK AND TEMPERATURE PROFILE. GFS IS FURTHER
NORTH...WHICH MAY HAVE SOMETHING TO DO WITH LATENT HEAT RELEASE
RELOCATING THE LOW FURTHER NORTH. WHILE THIS CAN HAPPEN...THE GFS
CAN OVERDO THIS AT TIMES. PREFERENCE AT THIS POINT IS A BLEND OF THE
ECMWF AND GFS SOLUTIONS...LEANING CLOSER TO THE ECMWF. WHILE THE GEM
CAN NOT BE COMPLETELY RULED OUT AND HAS BEEN CONSISTENT ON ITS
SOUTHERN TRACK...FEEL THAT SOLUTION IS A LOWER PROBABILITY AT THIS
TIME. THIS BLEND RESULTS IN A SURFACE TRACK BETWEEN TEKAMAH NEBRASKA
AND SIOUX CITY IOWA.
HERE ARE OUR CURRENT THOUGHTS ON EVOLUTION FOLLOWING THE ABOVE
BLEND. PRECIPITATION WILL BEGIN SATURDAY EVENING MAINLY AS
RAIN...WITH SOME SLEET POSSIBLE MIXED IN ACROSS SOUTHWEST MINNESOTA.
EVERYWHERE EAST OF THE JAMES RIVER SHOULD REMAIN MAINLY RAIN
THROUGH MIDNIGHT. THE RAIN WILL LIKELY TRANSITION TO SNOW WEST OF
THE JAMES RIVER BY MIDNIGHT. AFTER MIDNIGHT THE RAIN MAY MIX WITH
SNOW EAST OF THE JAMES RIVER...MAINLY ALONG AND NORTH OF INTERSTATE
90...ALTHOUGH ACCUMULATIONS DURING THIS PERIOD WOULD BE LIGHT. THE
TOUGHEST FORECAST COMES IN THE 12Z TO 18Z TIMEFRAME. DURING THIS
PERIOD A BAND OF HEAVY PRECIP WITH THE 850MB FRONTOGENESIS WILL BE
OVER THE CWA. THIS WILL LIKELY BE ALL SNOW WEST OF THE JAMES RIVER
AND ALONG THE HIGHWAY 14 CORRIDOR. CLOSER TO INTERSTATE 90 WILL BE A
CLOSE CALL. FOR EXAMPLE...IN SIOUX FALLS THE ECMWF WOULD SUGGEST ALL
SNOW AND SEVERAL INCHES...WHILE THE GFS WOULD BE RAIN. IT WILL BE A
BATTLE BETWEEN WARM SOUTHEASTERLY FLOW...DYNAMIC COOLING FROM THE
HIGH PRECIP RATES...AND A COOL NORTHEASTERLY AGEOSTROPHIC FLOW. FEEL
LIKE RAIN TO SNOW OR A RAIN/SNOW MIX IS MOST LIKELY IN THIS TIME
FRAME FOR THE SIOUX FALLS AREA...WITH THE GFS TOO WARM AND THE ECMWF
A BIT TOO COOL. AFTER 18Z EVERYONE EXCEPT NORTHWEST IOWA SHOULD BE
SNOW...WITH A DECENT TROWAL SNOW BAND EXPECTED TO SETUP SOMEWHERE
OVER THE CWA...WITH THE GREATEST AMOUNTS FROM THIS TROWAL IN THE
BROOKINGS TO MARSHALL CORRIDOR. EVENTUALLY EVEN NORTHWEST IOWA WILL
GO OVER TO SOME LIGHT SNOW BEFORE THE PRECIP WINDS DOWN LATE SUNDAY
NIGHT.
WITH THE ABOVE IN MIND...HAVE OPTED TO EXPAND OUR PREVIOUS WATCH AND
CHANGE IT TO A BLIZZARD WATCH. NORTHWEST WINDS WILL REALLY INCREASE
FROM WEST TO EAST SATURDAY NIGHT INTO SUNDAY..WITH GUSTS OVER 50 MPH
POSSIBLE. SOME OF THE SNOW EAST OF THE JAMES RIVER WILL FALL BEFORE
WINDS REALLY PICK UP...BUT DID NOT WANT TO HAVE TWO DIFFERENT WINTER
HEADLINES GOING. SO OPTED TO GO JUST WITH A BLIZZARD WATCH COVERING
THE ENTIRE EVENT. ACCUMULATIONS OF 7 TO 14 INCHES SEEM POSSIBLE FROM
GREGORY COUNTY TO MITCHELL TO MARSHALL AND POINTS NORTHWEST. 4 TO 8
INCHES IS THE CURRENT THOUGH FROM BON HOMME TO SIOUX FALLS TO
WINDOM. AMOUNTS OF AN INCH OR TWO ARE POSSIBLE ACROSS NORTHWEST
IOWA. ONE THING TO NOTE IS THAT THE HIGHER ACCUMULATIONS IN THE WEST
ARE HIGHER CONFIDENCE...WHILE THE 4 TO 8 ZONE IS LOW CONFIDENCE.
DECIDED TO EXTEND THE WATCH SOUTH INTO THIS AREA...BECAUSE EVEN IF
THE SUNDAY MORNING SHOT OF PRECIP IS ALL RAIN...THE TROWAL SNOWS
COMBINED WITH STRONG WINDS MAY STILL CAUSE BLIZZARD CONDITIONS. THUS
EVEN IF SOME AREAS RECEIVE LESS THAN 6 INCHES OF SNOW...BLIZZARD
CONDITIONS ARE STILL POSSIBLE. FUTURE ADJUSTMENTS IN THESE HEADLINES
ARE LIKELY...BUT FEEL THE CURRENT LOCATION REPRESENTS THE AREA OF
HIGHEST PROBABILITY OF BLIZZARD CONDITIONS. KEEP IN MIND ANY SHIFTS
IN TRACK WILL HAVE A BIG IMPACT ON TOTAL SNOW AMOUNTS AND WHEN THE
RAIN CHANGES TO SNOW.
THE FALLING SNOW WILL END MONDAY MORNING...BUT BLOWING AND DRIFTING
IS LIKELY TO CONTINUE THROUGH THE DAY. THE EXTENDED PART OF THE
FORECAST WAS LEFT WITH ALLBLEND...SO MORE FOCUS COULD BE GIVEN TO
THE POTENTIAL BLIZZARD. OVERALL IT LOOKS LIKE TEMPERATURES STAY NEAR
NORMAL THROUGH THE EXTENDED...WITH NO REAL COLD SHOTS OR BIG WARM
UPS SEEN. A SYSTEM IN THE NORTHWEST FLOW MAY BRING SOME LIGHT SNOW
BACK INTO THE REGION ON THURSDAY...OTHERWISE THE EXTENDED LOOKS DRY.
/CHENARD
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...BLIZZARD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT
FOR MNZ071-072-080-081-097.
NE...NONE.
SD...BLIZZARD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT
FOR SDZ040-054>056-059>062-064-065-068.
BLIZZARD WATCH FROM SATURDAY EVENING THROUGH LATE SUNDAY NIGHT
FOR SDZ038-039-050-052-053-057-058-063.
&&
$$
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
558 AM CST FRI FEB 8 2013
.DISCUSSION.../ISSUED AT 444 AM CST/
MAIN CONCERN THE NEXT 24 HOURS IS THE STRATUS AND HOW FAST IT
DISSIPATES/ADVECTS OUT. NO MODEL EXCEPT THE RAP HAS A REAL HANDLE ON
THE STRATUS WITH NAM AND GFS ERODING STRATUS THIS MORNING WHILE RAP
KEEPS OVER MUCH OF THE AREA THROUGH 00Z. THEREFORE...GIVEN THICKNESS
AND WIDESPREAD NATURE OF STRATUS HAVE FOLLOWED THE RAP THROUGH 21Z
AND THEN USED NAM AND GFS 925 MB WINDS TO GIVE INDICATION OF WHEN
FLOW HAS ENOUGH WESTERLY COMPONENT TO ADVECT CLOUDS TO THE
NORTHEAST. THIS KEEP CLOUDS EAST OF THE JAMES ALL DAY WITH THE SW MN
AND NW IA LIKELY NOT CLEAR UNTIL WELL AFTER SUNSET. WITH CLOUDS MOST
OF THE DAY...TEMPERATURES WILL STRUGGLE TO RISE MUCH. BASICALLY WENT
ISOTHERMAL FROM 925 MB EAST OF THE JAMES WHICH KEEPS HIGHS FROM
UPPER 20S TO LOWER 30S. ALONG AND EAST OF THE JAMES...MORE SUNSHINE
IN THE AFTERNOON WILL ENHANCE MIXING AS WARMER AIR MOVES IN ALOFT.
SO HAVE HIGHS IN THE MID 30S AROUND HON AND MHE TO UPPER 40S IN
GREGORY COUNTY.
DESPITE CLEARING SKIES...INCREASING SOUTHEAST FLOW WILL KEEP
ATMOSPHERE FAIRLY WELL MIXED TONIGHT. EXPECT LOWS TO ONLY DROP 5
DEGREES OR SO EAST OF THE JAMES AS WARMER AIR MOVES IN ALOFT. WHERE
TEMPERATURES RISE WELL ABOVE FREEZING...EXPECT THEM TO FALL TOWARD
FREEZING OVERNIGHT BUT STILL FAIRLY MILD. EXPECT TO SEE CIRRUS
SLOWLY INCREASE THROUGH THE NIGHT AS STRONG UPPER LOW MOVES INTO THE
ROCKIES./SCHUMACHER
ATTENTION THEN TURNS TO A POTENTIAL BLIZZARD ACROSS THE NORTHERN
PLAINS SATURDAY NIGHT INTO SUNDAY NIGHT. MODELS IN FAIRLY GOOD
AGREEMENT...BUT SMALL DIFFERENCES EXIST...AND UNFORTUNATELY OUR CWA
IS SITUATED IN A LOCATION THAT ONLY SMALL SHIFTS IN THE STORM TRACK
WILL HAVE SIGNIFICANT IMPACTS ON WEATHER CONDITIONS. NAM/SREF ARE
NORTHERN OUTLIERS AND WERE NOT NOT USED IN THIS FORECAST DUE TO
UNREALISTIC LOOKING WAVE EVOLUTION. THE MODELS CONSIDERED WERE THUS
THE GFS/ECMWF/UKMET AND GEM. OF THIS GROUP...THE GFS IS THE FURTHEST
NORTH...THE GEM/UKMET THE FURTHEST SOUTH AND THE ECMWF IN BETWEEN.
THE 4 MODELS HAVE BEEN VERY CONSISTENT IN THEIR OWN SOLUTIONS. THE
GEM IS STRONGEST AND QUICKEST WITH THE NORTHERN STREAM WAVE...WHICH
KEEPS THE SURFACE LOW FURTHEST SOUTH. IT IS THUS THE COLDEST
SOLUTION AND WOULD GIVE MORE AREAS SNOW. THE 0Z GFS AND ECMWF ARE
VERY SIMILAR WITH THEIR UPPER AIR PATTERNS...BUT DIFFER WITH REGARDS
TO SURFACE LOW TRACK AND TEMPERATURE PROFILE. GFS IS FURTHER
NORTH...WHICH MAY HAVE SOMETHING TO DO WITH LATENT HEAT RELEASE
RELOCATING THE LOW FURTHER NORTH. WHILE THIS CAN HAPPEN...THE GFS
CAN OVERDO THIS AT TIMES. PREFERENCE AT THIS POINT IS A BLEND OF THE
ECMWF AND GFS SOLUTIONS...LEANING CLOSER TO THE ECMWF. WHILE THE GEM
CAN NOT BE COMPLETELY RULED OUT AND HAS BEEN CONSISTENT ON ITS
SOUTHERN TRACK...FEEL THAT SOLUTION IS A LOWER PROBABILITY AT THIS
TIME. THIS BLEND RESULTS IN A SURFACE TRACK BETWEEN TEKAMAH NEBRASKA
AND SIOUX CITY IOWA.
HERE ARE OUR CURRENT THOUGHTS ON EVOLUTION FOLLOWING THE ABOVE
BLEND. PRECIPITATION WILL BEGIN SATURDAY EVENING MAINLY AS
RAIN...WITH SOME SLEET POSSIBLE MIXED IN ACROSS SOUTHWEST MINNESOTA.
EVERYWHERE EAST OF THE JAMES RIVER SHOULD REMAIN MAINLY RAIN
THROUGH MIDNIGHT. THE RAIN WILL LIKELY TRANSITION TO SNOW WEST OF
THE JAMES RIVER BY MIDNIGHT. AFTER MIDNIGHT THE RAIN MAY MIX WITH
SNOW EAST OF THE JAMES RIVER...MAINLY ALONG AND NORTH OF INTERSTATE
90...ALTHOUGH ACCUMULATIONS DURING THIS PERIOD WOULD BE LIGHT. THE
TOUGHEST FORECAST COMES IN THE 12Z TO 18Z TIMEFRAME. DURING THIS
PERIOD A BAND OF HEAVY PRECIP WITH THE 850MB FRONTOGENESIS WILL BE
OVER THE CWA. THIS WILL LIKELY BE ALL SNOW WEST OF THE JAMES RIVER
AND ALONG THE HIGHWAY 14 CORRIDOR. CLOSER TO INTERSTATE 90 WILL BE A
CLOSE CALL. FOR EXAMPLE...IN SIOUX FALLS THE ECMWF WOULD SUGGEST ALL
SNOW AND SEVERAL INCHES...WHILE THE GFS WOULD BE RAIN. IT WILL BE A
BATTLE BETWEEN WARM SOUTHEASTERLY FLOW...DYNAMIC COOLING FROM THE
HIGH PRECIP RATES...AND A COOL NORTHEASTERLY AGEOSTROPHIC FLOW. FEEL
LIKE RAIN TO SNOW OR A RAIN/SNOW MIX IS MOST LIKELY IN THIS TIME
FRAME FOR THE SIOUX FALLS AREA...WITH THE GFS TOO WARM AND THE ECMWF
A BIT TOO COOL. AFTER 18Z EVERYONE EXCEPT NORTHWEST IOWA SHOULD BE
SNOW...WITH A DECENT TROWAL SNOW BAND EXPECTED TO SETUP SOMEWHERE
OVER THE CWA...WITH THE GREATEST AMOUNTS FROM THIS TROWAL IN THE
BROOKINGS TO MARSHALL CORRIDOR. EVENTUALLY EVEN NORTHWEST IOWA WILL
GO OVER TO SOME LIGHT SNOW BEFORE THE PRECIP WINDS DOWN LATE SUNDAY
NIGHT.
WITH THE ABOVE IN MIND...HAVE OPTED TO EXPAND OUR PREVIOUS WATCH AND
CHANGE IT TO A BLIZZARD WATCH. NORTHWEST WINDS WILL REALLY INCREASE
FROM WEST TO EAST SATURDAY NIGHT INTO SUNDAY..WITH GUSTS OVER 50 MPH
POSSIBLE. SOME OF THE SNOW EAST OF THE JAMES RIVER WILL FALL BEFORE
WINDS REALLY PICK UP...BUT DID NOT WANT TO HAVE TWO DIFFERENT WINTER
HEADLINES GOING. SO OPTED TO GO JUST WITH A BLIZZARD WATCH COVERING
THE ENTIRE EVENT. ACCUMULATIONS OF 7 TO 14 INCHES SEEM POSSIBLE FROM
GREGORY COUNTY TO MITCHELL TO MARSHALL AND POINTS NORTHWEST. 4 TO 8
INCHES IS THE CURRENT THOUGH FROM BON HOMME TO SIOUX FALLS TO
WINDOM. AMOUNTS OF AN INCH OR TWO ARE POSSIBLE ACROSS NORTHWEST
IOWA. ONE THING TO NOTE IS THAT THE HIGHER ACCUMULATIONS IN THE WEST
ARE HIGHER CONFIDENCE...WHILE THE 4 TO 8 ZONE IS LOW CONFIDENCE.
DECIDED TO EXTEND THE WATCH SOUTH INTO THIS AREA...BECAUSE EVEN IF
THE SUNDAY MORNING SHOT OF PRECIP IS ALL RAIN...THE TROWAL SNOWS
COMBINED WITH STRONG WINDS MAY STILL CAUSE BLIZZARD CONDITIONS. THUS
EVEN IF SOME AREAS RECEIVE LESS THAN 6 INCHES OF SNOW...BLIZZARD
CONDITIONS ARE STILL POSSIBLE. FUTURE ADJUSTMENTS IN THESE HEADLINES
ARE LIKELY...BUT FEEL THE CURRENT LOCATION REPRESENTS THE AREA OF
HIGHEST PROBABILITY OF BLIZZARD CONDITIONS. KEEP IN MIND ANY SHIFTS
IN TRACK WILL HAVE A BIG IMPACT ON TOTAL SNOW AMOUNTS AND WHEN THE
RAIN CHANGES TO SNOW.
THE FALLING SNOW WILL END MONDAY MORNING...BUT BLOWING AND DRIFTING
IS LIKELY TO CONTINUE THROUGH THE DAY. THE EXTENDED PART OF THE
FORECAST WAS LEFT WITH ALLBLEND...SO MORE FOCUS COULD BE GIVEN TO
THE POTENTIAL BLIZZARD. OVERALL IT LOOKS LIKE TEMPERATURES STAY NEAR
NORMAL THROUGH THE EXTENDED...WITH NO REAL COLD SHOTS OR BIG WARM
UPS SEEN. A SYSTEM IN THE NORTHWEST FLOW MAY BRING SOME LIGHT SNOW
BACK INTO THE REGION ON THURSDAY...OTHERWISE THE EXTENDED LOOKS DRY.
/CHENARD
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
BROAD AREA OF IFR/MVFR STRATUS CONTINUES TO SIT ACROSS THE REGION
THIS MORNING. GFS/NAM ARE NOT HANDLING THIS WELL AT ALL. THUS
FOLLOWED CLOSER TO THE RAP...WHICH SUGGESTS STRATUS STICKS AROUND AT
OUR TAF SITES THROUGH THE DAY. CIGS IN THE STRATUS ARE EXPECTED TO
REMAIN RIGHT AROUND 1K FEET. EVEN THOUGH BOUNDARY LAYER WINDS TURN
MORE SOUTHERLY TODAY...STRATUS DECK EXTENDS WELL SOUTHEAST OF US AND
THIS TURN OF FLOW WILL ONLY ACT TO CONTINUE TO ADVECT IN MORE
STRATUS. TIMING OF WHEN STRATUS EXITS IS VERY UNCERTAIN. DELAYED THE
EXIT TIME WITH THESE TAFS...BUT MAY STILL BE TOO EARLY AS BOUNDARY
LAYER FLOW STAYS SOUTHEASTERLY THROUGH THE TAF PERIOD...WHICH MAY
MAKE IT TOUGH TO ERODE THE CLOUDS THROUGH 12Z. WINDS WILL BE
BLUSTERY OUT OF THE SOUTH SOUTHEAST THIS AFTERNOON...WITH GUSTS UP
TO 25 KTS EXPECTED AT THE TAF SITES. /CHENARD
.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...BLIZZARD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT
FOR MNZ071-072-080-081-097.
NE...NONE.
SD...BLIZZARD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT
FOR SDZ040-054>056-059>062-064-065-068.
BLIZZARD WATCH FROM SATURDAY EVENING THROUGH LATE SUNDAY NIGHT
FOR SDZ038-039-050-052-053-057-058-063.
&&
$$
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
444 AM CST FRI FEB 8 2013
.DISCUSSION.../ISSUED AT 444 AM CST/
MAIN CONCERN THE NEXT 24 HOURS IS THE STRATUS AND HOW FAST IT
DISSIPATES/ADVECTS OUT. NO MODEL EXCEPT THE RAP HAS A REAL HANDLE ON
THE STRATUS WITH NAM AND GFS ERODING STRATUS THIS MORNING WHILE RAP
KEEPS OVER MUCH OF THE AREA THROUGH 00Z. THEREFORE...GIVEN THICKNESS
AND WIDESPREAD NATURE OF STRATUS HAVE FOLLOWED THE RAP THROUGH 21Z
AND THEN USED NAM AND GFS 925 MB WINDS TO GIVE INDICATION OF WHEN
FLOW HAS ENOUGH WESTERLY COMPONENT TO ADVECT CLOUDS TO THE
NORTHEAST. THIS KEEP CLOUDS EAST OF THE JAMES ALL DAY WITH THE SW MN
AND NW IA LIKELY NOT CLEAR UNTIL WELL AFTER SUNSET. WITH CLOUDS MOST
OF THE DAY...TEMPERATURES WILL STRUGGLE TO RISE MUCH. BASICALLY WENT
ISOTHERMAL FROM 925 MB EAST OF THE JAMES WHICH KEEPS HIGHS FROM
UPPER 20S TO LOWER 30S. ALONG AND EAST OF THE JAMES...MORE SUNSHINE
IN THE AFTERNOON WILL ENHANCE MIXING AS WARMER AIR MOVES IN ALOFT.
SO HAVE HIGHS IN THE MID 30S AROUND HON AND MHE TO UPPER 40S IN
GREGORY COUNTY.
DESPITE CLEARING SKIES...INCREASING SOUTHEAST FLOW WILL KEEP
ATMOSPHERE FAIRLY WELL MIXED TONIGHT. EXPECT LOWS TO ONLY DROP 5
DEGREES OR SO EAST OF THE JAMES AS WARMER AIR MOVES IN ALOFT. WHERE
TEMPERATURES RISE WELL ABOVE FREEZING...EXPECT THEM TO FALL TOWARD
FREEZING OVERNIGHT BUT STILL FAIRLY MILD. EXPECT TO SEE CIRRUS
SLOWLY INCREASE THROUGH THE NIGHT AS STRONG UPPER LOW MOVES INTO THE
ROCKIES./SCHUMACHER
ATTENTION THEN TURNS TO A POTENTIAL BLIZZARD ACROSS THE NORTHERN
PLAINS SATURDAY NIGHT INTO SUNDAY NIGHT. MODELS IN FAIRLY GOOD
AGREEMENT...BUT SMALL DIFFERENCES EXIST...AND UNFORTUNATELY OUR CWA
IS SITUATED IN A LOCATION THAT ONLY SMALL SHIFTS IN THE STORM TRACK
WILL HAVE SIGNIFICANT IMPACTS ON WEATHER CONDITIONS. NAM/SREF ARE
NORTHERN OUTLIERS AND WERE NOT NOT USED IN THIS FORECAST DUE TO
UNREALISTIC LOOKING WAVE EVOLUTION. THE MODELS CONSIDERED WERE THUS
THE GFS/ECMWF/UKMET AND GEM. OF THIS GROUP...THE GFS IS THE FURTHEST
NORTH...THE GEM/UKMET THE FURTHEST SOUTH AND THE ECMWF IN BETWEEN.
THE 4 MODELS HAVE BEEN VERY CONSISTENT IN THEIR OWN SOLUTIONS. THE
GEM IS STRONGEST AND QUICKEST WITH THE NORTHERN STREAM WAVE...WHICH
KEEPS THE SURFACE LOW FURTHEST SOUTH. IT IS THUS THE COLDEST
SOLUTION AND WOULD GIVE MORE AREAS SNOW. THE 0Z GFS AND ECMWF ARE
VERY SIMILAR WITH THEIR UPPER AIR PATTERNS...BUT DIFFER WITH REGARDS
TO SURFACE LOW TRACK AND TEMPERATURE PROFILE. GFS IS FURTHER
NORTH...WHICH MAY HAVE SOMETHING TO DO WITH LATENT HEAT RELEASE
RELOCATING THE LOW FURTHER NORTH. WHILE THIS CAN HAPPEN...THE GFS
CAN OVERDO THIS AT TIMES. PREFERENCE AT THIS POINT IS A BLEND OF THE
ECMWF AND GFS SOLUTIONS...LEANING CLOSER TO THE ECMWF. WHILE THE GEM
CAN NOT BE COMPLETELY RULED OUT AND HAS BEEN CONSISTENT ON ITS
SOUTHERN TRACK...FEEL THAT SOLUTION IS A LOWER PROBABILITY AT THIS
TIME. THIS BLEND RESULTS IN A SURFACE TRACK BETWEEN TEKAMAH NEBRASKA
AND SIOUX CITY IOWA.
HERE ARE OUR CURRENT THOUGHTS ON EVOLUTION FOLLOWING THE ABOVE
BLEND. PRECIPITATION WILL BEGIN SATURDAY EVENING MAINLY AS
RAIN...WITH SOME SLEET POSSIBLE MIXED IN ACROSS SOUTHWEST MINNESOTA.
EVERYWHERE EAST OF THE JAMES RIVER SHOULD REMAIN MAINLY RAIN
THROUGH MIDNIGHT. THE RAIN WILL LIKELY TRANSITION TO SNOW WEST OF
THE JAMES RIVER BY MIDNIGHT. AFTER MIDNIGHT THE RAIN MAY MIX WITH
SNOW EAST OF THE JAMES RIVER...MAINLY ALONG AND NORTH OF INTERSTATE
90...ALTHOUGH ACCUMULATIONS DURING THIS PERIOD WOULD BE LIGHT. THE
TOUGHEST FORECAST COMES IN THE 12Z TO 18Z TIMEFRAME. DURING THIS
PERIOD A BAND OF HEAVY PRECIP WITH THE 850MB FRONTOGENESIS WILL BE
OVER THE CWA. THIS WILL LIKELY BE ALL SNOW WEST OF THE JAMES RIVER
AND ALONG THE HIGHWAY 14 CORRIDOR. CLOSER TO INTERSTATE 90 WILL BE A
CLOSE CALL. FOR EXAMPLE...IN SIOUX FALLS THE ECMWF WOULD SUGGEST ALL
SNOW AND SEVERAL INCHES...WHILE THE GFS WOULD BE RAIN. IT WILL BE A
BATTLE BETWEEN WARM SOUTHEASTERLY FLOW...DYNAMIC COOLING FROM THE
HIGH PRECIP RATES...AND A COOL NORTHEASTERLY AGEOSTROPHIC FLOW. FEEL
LIKE RAIN TO SNOW OR A RAIN/SNOW MIX IS MOST LIKELY IN THIS TIME
FRAME FOR THE SIOUX FALLS AREA...WITH THE GFS TOO WARM AND THE ECMWF
A BIT TOO COOL. AFTER 18Z EVERYONE EXCEPT NORTHWEST IOWA SHOULD BE
SNOW...WITH A DECENT TROWAL SNOW BAND EXPECTED TO SETUP SOMEWHERE
OVER THE CWA...WITH THE GREATEST AMOUNTS FROM THIS TROWAL IN THE
BROOKINGS TO MARSHALL CORRIDOR. EVENTUALLY EVEN NORTHWEST IOWA WILL
GO OVER TO SOME LIGHT SNOW BEFORE THE PRECIP WINDS DOWN LATE SUNDAY
NIGHT.
WITH THE ABOVE IN MIND...HAVE OPTED TO EXPAND OUR PREVIOUS WATCH AND
CHANGE IT TO A BLIZZARD WATCH. NORTHWEST WINDS WILL REALLY INCREASE
FROM WEST TO EAST SATURDAY NIGHT INTO SUNDAY..WITH GUSTS OVER 50 MPH
POSSIBLE. SOME OF THE SNOW EAST OF THE JAMES RIVER WILL FALL BEFORE
WINDS REALLY PICK UP...BUT DID NOT WANT TO HAVE TWO DIFFERENT WINTER
HEADLINES GOING. SO OPTED TO GO JUST WITH A BLIZZARD WATCH COVERING
THE ENTIRE EVENT. ACCUMULATIONS OF 7 TO 14 INCHES SEEM POSSIBLE FROM
GREGORY COUNTY TO MITCHELL TO MARSHALL AND POINTS NORTHWEST. 4 TO 8
INCHES IS THE CURRENT THOUGH FROM BON HOMME TO SIOUX FALLS TO
WINDOM. AMOUNTS OF AN INCH OR TWO ARE POSSIBLE ACROSS NORTHWEST
IOWA. ONE THING TO NOTE IS THAT THE HIGHER ACCUMULATIONS IN THE WEST
ARE HIGHER CONFIDENCE...WHILE THE 4 TO 8 ZONE IS LOW CONFIDENCE.
DECIDED TO EXTEND THE WATCH SOUTH INTO THIS AREA...BECAUSE EVEN IF
THE SUNDAY MORNING SHOT OF PRECIP IS ALL RAIN...THE TROWAL SNOWS
COMBINED WITH STRONG WINDS MAY STILL CAUSE BLIZZARD CONDITIONS. THUS
EVEN IF SOME AREAS RECEIVE LESS THAN 6 INCHES OF SNOW...BLIZZARD
CONDITIONS ARE STILL POSSIBLE. FUTURE ADJUSTMENTS IN THESE HEADLINES
ARE LIKELY...BUT FEEL THE CURRENT LOCATION REPRESENTS THE AREA OF
HIGHEST PROBABILITY OF BLIZZARD CONDITIONS. KEEP IN MIND ANY SHIFTS
IN TRACK WILL HAVE A BIG IMPACT ON TOTAL SNOW AMOUNTS AND WHEN THE
RAIN CHANGES TO SNOW.
THE FALLING SNOW WILL END MONDAY MORNING...BUT BLOWING AND DRIFTING
IS LIKELY TO CONTINUE THROUGH THE DAY. THE EXTENDED PART OF THE
FORECAST WAS LEFT WITH ALLBLEND...SO MORE FOCUS COULD BE GIVEN TO
THE POTENTIAL BLIZZARD. OVERALL IT LOOKS LIKE TEMPERATURES STAY NEAR
NORMAL THROUGH THE EXTENDED...WITH NO REAL COLD SHOTS OR BIG WARM
UPS SEEN. A SYSTEM IN THE NORTHWEST FLOW MAY BRING SOME LIGHT SNOW
BACK INTO THE REGION ON THURSDAY...OTHERWISE THE EXTENDED LOOKS DRY.
/CHENARD
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
BROAD AREA OF IFR/MVFR STRATUS CONTINUES TO SIT ACROSS THE REGION
THIS MORNING. GFS/NAM ARE NOT HANDLING THIS WELL AT ALL. THUS
FOLLOWED CLOSER TO THE RAP...WHICH SUGGESTS STRATUS STICKS AROUND AT
OUR TAF SITES THROUGH THE DAY. CIGS IN THE STRATUS ARE EXPECTED TO
REMAIN RIGHT AROUND 1K FEET. EVEN THOUGH BOUNDARY LAYER WINDS TURN
MORE SOUTHERLY TODAY...STRATUS DECK EXTENDS WELL SOUTHEAST OF US AND
THIS TURN OF FLOW WILL ONLY ACT TO CONTINUE TO ADVECT IN MORE
STRATUS. TIMING OF WHEN STRATUS EXITS IS VERY UNCERTAIN. DELAYED THE
EXIT TIME WITH THESE TAFS...BUT MAY STILL BE TOO EARLY AS BOUNDARY
LAYER FLOW STAYS SOUTHEASTERLY THROUGH THE TAF PERIOD...WHICH MAY
MAKE IT TOUGH TO ERODE THE CLOUDS THROUGH 12Z. WINDS WILL BE
BLUSTERY OUT OF THE SOUTH SOUTHEAST THIS AFTERNOON...WITH GUSTS UP
TO 25 KTS EXPECTED AT THE TAF SITES. /CHENARD
.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...BLIZZARD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT
FOR MNZ071-072-080-081-097.
NE...NONE.
SD...BLIZZARD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT
FOR SDZ040-054>056-059>062-064-065-068.
BLIZZARD WATCH FROM SATURDAY EVENING THROUGH LATE SUNDAY NIGHT
FOR SDZ038-039-050-052-053-057-058-063.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
950 AM CST FRI FEB 8 2013
.UPDATE...
UPDATED SKY COVER FOR THIS AFTERNOON.
&&
.DISCUSSION...
NORTH TO NORTHEASTERLY LOW LEVEL FLOW WILL LIKELY PREVENT THE
COLD AIR STRATOCUMULUS FROM CLEARING ACROSS THE MIDSOUTH EARLY
THIS AFTERNOON...BUT RATHER CLOSER TO SUNSET....SO HAVE ADJUSTED
THE AFTERNOON SKY COVER FORECASTS ACCORDINGLY. THE REMAINDER OF
THE FORECAST APPEARS TO BE ON TRACK.
JAB
&&
.PREV DISCUSSION... /ISSUED 501 AM CST FRI FEB 8 2013/
DISCUSSION... /ISSUED 427 AM CST FRI FEB 8 2013/
SCATTERED SHOWERS WERE NOTED ALONG AND SOUTHEAST OF THE I40
CORRIDOR AT 415 AM...LIFTING EAST. GOES WATER IMAGERY SHOWED THE
PARENT UPPER LEVEL SHORTWAVE ON TRACK TO EXIT THE MIDSOUTH LATER
THIS MORNING. AT THE SURFACE...DRIER LOW LEVEL AIR SPREADS IN
BEHIND A PACIFIC COLD FRONT.
UPPER LEVEL RIDGING WILL SPREAD INTO THE MIDSOUTH TONIGHT AND
SATURDAY...IN ADVANCE OF A DEEP LONGWAVE TROF OVER THE GREAT BASIN.
MOIST LOW LEVEL RETURN FLOW AND INCREASED CLOUD COVER WILL ENSURE
MILD MINIMUM TEMPS SUNDAY MORNING.
THE MODELS ARE IN GOOD AGREEMENT IN LIFTING THE GREAT BASIN UPPER
LOW INTO THE UPPER MIDWEST SUNDAY EVENING. THE ASSOCIATED SURFACE
LOW WILL LIKEWISE REMAIN FAR REMOVED FROM THE MIDSOUTH...TRACKING
NEAR THE 500MB LOW CENTER. BEST RAIN CHANCES FOR THE MIDSOUTH WILL
BE FOCUSED SUNDAY AFTERNOON...ASSOCIATED WITH THE PASSAGE OF A
PACIFIC COLD FRONT AND MIDLEVEL TROF AXIS.
WITH SUNDAY/S SYSTEM LIKELY OCCLUDED OVER THE LOWER MS RIVER
VALLEY...MODEST ELEVATED INSTABILITY AND LAPSE RATES... SEVERE
WEATHER IS NOT ANTICIPATED OVER THE MIDSOUTH. A FEW STRONG WIND
GUSTS MAY OCCUR...IF ANY BOWING SEGMENTS ARE ABLE TO BRING DOWN
THE 50 TO 60KT REAR INFLOW WINDS ABOVE 900MB.
GFS AND ECMWF ARE IN AGREEMENT IN DEVELOPING ANOTHER UPPER LOW
OVER THE GREAT BASIN SUNDAY NIGHT INTO EARLY MONDAY. THIS FEATURE
WILL OPEN UP AND TAKE A MORE EASTERLY TRAJECTORY THAN ITS
PREDECESSOR...TRACKING ACROSS THE LOWER MS RIVER VALLEY TUESDAY
NIGHT. GFS CONTINUES TO SHOW MORE PRECIP WITH THIS FEATURE THAN
WHEN COMPARED WITH THE ECMWF...PARTICULARLY ON THE 06Z GFS RUN. IN
ANY CASE... THE DRY AIRMASS BEHIND SUNDAY/S COLD FRONT WOULD POINT
TOWARD A LOW QPF EVENT...MAINLY ACROSS NORTH MS TUESDAY NIGHT.
GFS SOUNDINGS INDICATE SNOW DOWN TO 925MB...WITH ABOVE FREEZING
TEMPS BELOW THIS LEVEL AND SURFACE TEMPS UPPER 30S. HAVE INTRODUCED
A MIXTURE OF LIGHT RAIN AND FLURRIES TO NORTHEAST MS AND PORTIONS
OF WEST TN EAST OF MEMPHIS TUESDAY NIGHT.
THE REMAINDER OF THE WEEK APPEARS RELATIVELY TRANQUIL...WITH
FAST...NEARLY ZONAL FLOW ALOFT. ECMWF INDICATES A POTENTIAL FOR
ARCTIC AIR INTRUSION LATE NEXT WEEK. HOWEVER...BOTH ECMWF AND GFS
ARE SHOWING CONSIDERABLE RUN TO RUN VARIATIONS BEYOND 180 HOURS...
SO DAYS 7 TO 10 HOLD LOWER THAN NORMAL FORECAST CONFIDENCE.
PWB
&&
.AVIATION...
12Z TAF SET
TRICKY FORECAST WITH REGARDS TO LINGERING LIFR TO MVFR CIGS. BOTH
THE GFS AND RUC HOLDS ONTO THE LOW CLOUDS LONGER THAN THE NAM. THE
RUC ACTUALLY KEEPS LOW CIGS THROUGH THE EVENING HOURS. LOOKING AT
LATEST SATELLITE IMAGES...ABUNDANT LOW CLOUDS COVER THE MIDWEST TO
OHIO VALLEY. A LITTLE CONCERNED THAT THE CLOUDS WILL LINGER INTO
THIS EVENING AS THE RUC IS SHOWING THIS IS DUE TO WINDS ALOFT THAT WILL
REMAIN OUT OF THE NORTH OR NORTHEAST. THIS SHOULD KEEP THE LOW
CLOUDS IN THE AREA. HOWEVER...FOR NOW WILL USE LATEST MAV/LAV
GUIDANCE THAT KEEPS CLOUDS THROUGH AT LEAST EARLY AFTERNOON FOR
12Z TAFS. THUS MAKING 12Z TAFS MORE PESSIMISTIC THAN 6Z TAFS BUT
NOT AS PESSIMISTIC AS THE RUC. CIGS SHOULD GRADUALLY LIFT TO MVFR
WHERE CONDITIONS ARE CURRENTLY LIFR OR IFR. ALSO CAN/T RULE OUT A
FEW BREAKS HERE AND THERE BUT GENERALLY MVFR CIGS SHOULD CONTINUE
THROUGH AT LEAST 18-22Z. N TO NE WINDS OF 12-15 KTS WITH HIGHER
GUSTS WILL CONTINUE THROUGH MIDDAY. THEREAFTER...SPEEDS WILL
SLOWLY BEGIN TO DIMINISH AS DIRECTION BECOMES MORE NE.
KRM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 51 34 57 47 / 10 0 0 30
MKL 48 28 55 43 / 10 0 0 20
JBR 50 31 53 45 / 0 0 10 60
TUP 58 31 61 43 / 30 0 0 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
501 AM CST FRI FEB 8 2013
.DISCUSSION... /ISSUED 427 AM CST FRI FEB 8 2013/
SCATTERED SHOWERS WERE NOTED ALONG AND SOUTHEAST OF THE I40
CORRIDOR AT 415 AM...LIFTING EAST. GOES WATER IMAGERY SHOWED THE
PARENT UPPER LEVEL SHORTWAVE ON TRACK TO EXIT THE MIDSOUTH LATER
THIS MORNING. AT THE SURFACE...DRIER LOW LEVEL AIR SPREADS IN
BEHIND A PACIFIC COLD FRONT.
UPPER LEVEL RIDGING WILL SPREAD INTO THE MIDSOUTH TONIGHT AND
SATURDAY...IN ADVANCE OF A DEEP LONGWAVE TROF OVER THE GREAT BASIN.
MOIST LOW LEVEL RETURN FLOW AND INCREASED CLOUD COVER WILL ENSURE
MILD MINIMUM TEMPS SUNDAY MORNING.
THE MODELS ARE IN GOOD AGREEMENT IN LIFTING THE GREAT BASIN UPPER
LOW INTO THE UPPER MIDWEST SUNDAY EVENING. THE ASSOCIATED SURFACE
LOW WILL LIKEWISE REMAIN FAR REMOVED FROM THE MIDSOUTH...TRACKING
NEAR THE 500MB LOW CENTER. BEST RAIN CHANCES FOR THE MIDSOUTH WILL
BE FOCUSED SUNDAY AFTERNOON...ASSOCIATED WITH THE PASSAGE OF A
PACIFIC COLD FRONT AND MIDLEVEL TROF AXIS.
WITH SUNDAY/S SYSTEM LIKELY OCCLUDED OVER THE LOWER MS RIVER
VALLEY...MODEST ELEVATED INSTABILITY AND LAPSE RATES... SEVERE
WEATHER IS NOT ANTICIPATED OVER THE MIDSOUTH. A FEW STRONG WIND
GUSTS MAY OCCUR...IF ANY BOWING SEGMENTS ARE ABLE TO BRING DOWN
THE 50 TO 60KT REAR INFLOW WINDS ABOVE 900MB.
GFS AND ECMWF ARE IN AGREEMENT IN DEVELOPING ANOTHER UPPER LOW
OVER THE GREAT BASIN SUNDAY NIGHT INTO EARLY MONDAY. THIS FEATURE
WILL OPEN UP AND TAKE A MORE EASTERLY TRAJECTORY THAN ITS
PREDECESSOR...TRACKING ACROSS THE LOWER MS RIVER VALLEY TUESDAY
NIGHT. GFS CONTINUES TO SHOW MORE PRECIP WITH THIS FEATURE THAN
WHEN COMPARED WITH THE ECMWF...PARTICULARLY ON THE 06Z GFS RUN. IN
ANY CASE... THE DRY AIRMASS BEHIND SUNDAY/S COLD FRONT WOULD POINT
TOWARD A LOW QPF EVENT...MAINLY ACROSS NORTH MS TUESDAY NIGHT.
GFS SOUNDINGS INDICATE SNOW DOWN TO 925MB...WITH ABOVE FREEZING
TEMPS BELOW THIS LEVEL AND SURFACE TEMPS UPPER 30S. HAVE INTRODUCED
A MIXTURE OF LIGHT RAIN AND FLURRIES TO NORTHEAST MS AND PORTIONS
OF WEST TN EAST OF MEMPHIS TUESDAY NIGHT.
THE REMAINDER OF THE WEEK APPEARS RELATIVELY TRANQUIL...WITH
FAST...NEARLY ZONAL FLOW ALOFT. ECMWF INDICATES A POTENTIAL FOR
ARCTIC AIR INTRUSION LATE NEXT WEEK. HOWEVER...BOTH ECMWF AND GFS
ARE SHOWING CONSIDERABLE RUN TO RUN VARIATIONS BEYOND 180 HOURS...
SO DAYS 7 TO 10 HOLD LOWER THAN NORMAL FORECAST CONFIDENCE.
PWB
&&
.AVIATION...
12Z TAF SET
TRICKY FORECAST WITH REGARDS TO LINGERING LIFR TO MVFR CIGS. BOTH
THE GFS AND RUC HOLDS ONTO THE LOW CLOUDS LONGER THAN THE NAM. THE
RUC ACTUALLY KEEPS LOW CIGS THROUGH THE EVENING HOURS. LOOKING AT
LATEST SATELLITE IMAGES...ABUNDANT LOW CLOUDS COVER THE MIDWEST TO
OHIO VALLEY. A LITTLE CONCERNED THAT THE CLOUDS WILL LINGER INTO
THIS EVENING AS THE RUC IS SHOWING THIS IS DUE TO WINDS ALOFT THAT WILL
REMAIN OUT OF THE NORTH OR NORTHEAST. THIS SHOULD KEEP THE LOW
CLOUDS IN THE AREA. HOWEVER...FOR NOW WILL USE LATEST MAV/LAV
GUIDANCE THAT KEEPS CLOUDS THROUGH AT LEAST EARLY AFTERNOON FOR
12Z TAFS. THUS MAKING 12Z TAFS MORE PESSIMISTIC THAN 6Z TAFS BUT
NOT AS PESSIMISTIC AS THE RUC. CIGS SHOULD GRADUALLY LIFT TO MVFR
WHERE CONDITIONS ARE CURRENTLY LIFR OR IFR. ALSO CAN/T RULE OUT A
FEW BREAKS HERE AND THERE BUT GENERALLY MVFR CIGS SHOULD CONTINUE
THROUGH AT LEAST 18-22Z. N TO NE WINDS OF 12-15 KTS WITH HIGHER
GUSTS WILL CONTINUE THROUGH MIDDAY. THEREAFTER...SPEEDS WILL
SLOWLY BEGIN TO DIMINISH AS DIRECTION BECOMES MORE NE.
KRM
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 51 34 57 47 / 10 0 0 30
MKL 48 28 55 43 / 10 0 0 20
JBR 50 31 53 45 / 0 0 10 60
TUP 58 31 61 43 / 20 0 0 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
821 PM CST SAT FEB 9 2013
.UPDATE...
WE HAVE ALLOWED THE WIND ADVISORY AND WARNING TO EXPIRE ON
SCHEDULE AT 8 PM. WINDS...IN GENERAL...ARE COMING DOWN...THOUGH A
FEW SPOTS IMMEDIATELY BEHIND THE ADVANCING PACIFIC FRONT MAY
BRIEFLY TOUCH ADVISORY LEVELS. OTHER CONCERN WILL CONTINUE TO
REVOLVE AROUND DEVELOPING CONVECTION THAT IS FORMING ACROSS THE
NORTHEAST ZONES CURRENTLY. THIS CONVECTION IS OCCURRING IN A
WEAKLY UNSTABLE AIRMASS...BUT IS SUPPORTED BY INCREASING LARGE
SCALE ASCENT AND INCREASED LOW-LEVEL FORCING AS A PACIFIC FRONT
IS IMPINGING ON THE IMPROVED LOW-LEVEL MOISTURE RESIDING ACROSS
ROUGHLY THE EASTERN HALF OF THE CWA. COULD YET SEE A FEW
STRONG/SEVERE STORMS...LIKELY FAVORING THE NORTHEAST ZONES. IT
BECOMES MORE UNCERTAIN HOW FAR SOUTH THE CONVECTION CAN DEVELOP
INTO THE ROLLING PLAINS AS LOW-LEVEL CONVERGENCE IS PROGGED TO
WEAKEN WITH SOUTHERN EXTENT AND CIN INCREASE.
REGARDLESS...CONVECTION WILL QUICKLY SHIFT EAST...AND LIKELY BE
OUT OF THE CWA BY MIDNIGHT.
&&
.PREV DISCUSSION... /ISSUED 540 PM CST SAT FEB 9 2013/
AVIATION...
GUSTY STRONG WINDS WILL BE THE MAIN CONCERN AT BOTH TERMINALS
THROUGH 1 OR 2Z...AFTER WHICH THE WINDS SHOULD DECREASE TO LESS
THAN ABOUT 18 KTS SUSTAINED. SOME LIGHT BLOWING DUST IS EXPECTED AT
KLBB THROUGH 1Z. ALSO...THERE IS A CHANCE OF TSRA IN THE VICINITY
OF KCDS THROUGH ABOUT 4Z. A FRONT WILL MOVE EAST ACROSS THE AREA
BEFORE MIDNIGHT BRINGING A WIND SHIFT FROM SW TO WEST BUT WITH NOT
MUCH CHANGE IN WIND SPEED GIVEN THE TIME OF DAY. SUNDAY
MORNING...THE WINDS WILL RAMP UP AGAIN AS STRONG W-NW WINDS ALOFT
MIX DOWN. SOME LIGHT BLOWING DUST WILL BE POSSIBLE AT LUBBOCK
AGAIN BY MIDDAY. THE WINDS WILL START TO DIMINISH SUNDAY
AFTERNOON.
PREV DISCUSSION... /ISSUED 304 PM CST SAT FEB 9 2013/
SHORT TERM...
A BUSY AFTERNOON IS IN STORE FOR THE CWA... WITH BOTH HIGH WINDS IN THE
WEST AND THE POSSIBILITY FOR STORMS IN THE EAST. AS EXPECTED... A
POTENT TROUGH IS CURRENTLY ADVANCING ON WEST TEXAS... WITH A 500MB
KT MAX OF OVER 100KT CURRENTLY SITUATED OVER EASTERN NEW MEXICO.
HIGH CLOUDS HAVE CLEARED OVER MOST OF THE NW PORTION OF THE CWA AND
NEW MEXICO...ALLOWING FOR DEEP MIXING AND VERY STRONG WINDS ACROSS
MOST OF EASTERN NEW MEXICO. WINDS HAVE BEEN SLOW TO VEER IN WEST
TEXAS THIS AFTERNOON...ALLOWING DEWPOINTS TO CLIMB INTO THE UPPER
30S AND NEAR 40 ACROSS MOST OF THE CAPROCK AS OF 18Z. HOWEVER...
SURFACE OBS AND RADAR TRENDS ARE INDICATING THAT WINDS ARE FINALLY
BEGINNING TO VEER SLIGHTLY IN THE WEST... WHICH HAS RESULTED IN
RAPID DRYING AND INCREASING WIND SPEEDS JUST EAST OF THE TEXAS NEW
MEXICO BORDER. GIVEN THESE TRENDS... HAVE OPTED TO UPGRADE
PARMER...CASTRO AND BAILEY COUNTIES TO A HIGH WIND WARNING THROUGH
02Z. FIRE WEATHER CONCERNS ARE STILL MINIMAL... ESPECIALLY GIVEN
THE HIGHER THAN ANTICIPATED DEWPOINTS ACROSS THE WEST AND MOIST FUEL
CONDITIONS... HOWEVER ELEVATED FIRE WEATHER CONDITIONS AND SOME
RED FLAG MINUTES WILL BE PRESENT NEAR THE TX/NM BORDER THROUGH
THE EARLY EVENING WHERE THE AIR WILL BE DRIEST AND WINDS
STRONGEST.
FURTHER EAST... THE FORECAST STILL APPEARS TO BE LARGELY ON TRACK AS
MOISTURE CONTINUES TO RETURN ACROSS THE EAST. RADAR AND SURFACES
OBSERVATIONS INDICATE THE BEGINNINGS OF A DRYLINE FORMING JUST TO
THE EAST OF THE TX/NM STATE LINE...AND APPEARS TO BE SLOWLY
ADVANCING EAST. IN ADDITION... VISIBLE SATELLITE IMAGERY IS SHOWING
AN INCREASE IN CUMULIFORM CLOUDS JUST TO THE DRY SIDE OF THIS
DEVELOPING DRYLINE. DEWPOINTS AS OF 20Z HAVE REACHED THE UPPER 40S
ACROSS THE SOUTHEAST...TO NEAR 40 IN THE NORTHERN ROLLING
PLAINS...WHICH IS A BIT LOWER THAN YOU WOULD LIKE FOR STORM
DEVELOPMENT. AS SUCH... INSTABILITY IS STILL VERY WEAK ACROSS THE
AREA...WITH MAXIMUM VALUES OF NEAR 500 J/KG RESTRICTED TO THE
SOUTHEAST. THERE STILL REMAINS SOME TIME FOR MOISTURE TO
INCREASE...AND IT STILL SEEMS WITHIN REASON THAT DEWPOINTS WILL
REACH THE UPPER 40S TO LOW 50S WITHIN THE NEXT FEW HOURS. LOCAL
HIGH RESOLUTION MODELS...INCLUDING THE TTUWRF AND TO A LESSER EXTENT
THE HRRR... SEEM TO BE SUGGESTING THAT INITIATION MAY HOLD OFF UNTIL
00Z... HOWEVER THE RUC IS STILL FIRING AROUND 22Z. GIVEN CURRENT
TRENDS... IT SEEMS THAT THE LATER INITIATION SOLUTIONS SEEM MORE
PLAUSIBLE. GIVEN THE VERY STRONGLY SHEARED WIND FIELDS... ANY
STORMS THAT CAN MANAGE TO INITIATE EARLY WILL VERY LIKELY BE
SUPERCELLULAR... AND COULD POSE A VERY ISOLATED TORNADO THREAT IF
MOISTURE CAN CONTINUE TO RISE. HOWEVER...THIS THREAT APPEARS TO BE
VERY MARGINAL AT THIS TIME... AND A MORE LIKELY THREAT WILL BE
MARGINALLY SEVERE HAIL TO 1" AND DAMAGING WINDS TO 70 MPH. THE MOST
LIKELY AREA FOR INITIATION STILL APPEARS TO BE NORTH OF LBB AND
EASTWARD TOWARDS THE CHILDRESS AREA. LATER IN THE EVENING...A
PACIFIC FRONT WILL SWEEP THROUGH THE AREA...AND LIKELY INITIATE
MORE STORMS WITH A MORE LINEAR MODE. STORMS WILL LIKELY EXIT THE
AREA TO THE EAST BY 06Z.
FOR TOMORROW...BREEZY WESTERLY WINDS BETWEEN 20-30 MPH WILL PERSIST
ACROSS THE AREA DURING THE AFTERNOON...WHICH WHEN COMBINED WITH LOW DEWPOINTS
WILL RESULT IN ELEVATED FIRE WEATHER CONDITIONS....ESPECIALLY ACROSS
THE ROLLING PLAINS WHERE WARMER TEMPERATURES WILL RESULT IN LOWER RH
VALUES...
LONG TERM...
BY SUNDAY EVENING...FLOW ACROSS THE REGION WILL BE ZONAL TO SLIGHTLY
WEST SOUTHWESTERLY AS TODAY/S WIND MAKER EJECTS INTO THE GREAT
LAKES. TROUGH OUT WEST CONTINUES TO DEEPEN AND APPROACH LATE MONDAY
NIGHT. FLOW BECOMES NORTHWESTERLY BY WEDNESDAY WITH AN EMBEDDED
TROUGH DUE IN ON THURSDAY AND ANOTHER TROUGH DIGGING INTO THE
SOUTHWEST BY FRIDAY THOUGH MORE LATITUDINALLY ORIENTED THAN THE
EARLY WEEK SYSTEM. RIDGING BUILDS OUT WEST WITH STRONG NNW FLOW
WITH DECENT COLD AIR ADVECTION.
COLD FRONT SHOULD FINALLY MAKE IT INTO THE AREA SUNDAY EVENING WITH
WINDS BECOMING MORE OR LESS EASTERLY AND REMAINING IN FAVORABLE
UPSLOPE REGIME FOR MOISTURE ADVECTION. NAM/GFS/ECM HAVE COME INTO
GOOD AGREEMENT WITH SOME FAIRLY SUBSTANTIVE MOISTURE ADVECTION
MONDAY EVENING PERHAPS MAKING IT A BIT FURTHER WEST THAN EARLIER
THOUGHT. NEVERTHELESS...GENERAL TRENDS IN THE FORECAST REMAIN
INSOFAR AS MOISTURE GOES...BUT...WITH THE GREATER
MOISTURE...PRECIPITATION PHASE IS A BIT LESS CERTAIN WITH PHASE
REMAINING LIQUID UNTIL WRAP AROUND ON THE BACK SIDE OF THE
LOW...WITH LOWER TEMPS. GIVEN THIS FAIRLY RADICAL CHANGE THIS
RUN...WILL HOLD OFF ON MAKING MAJOR CHANGES TO ONGOING FORECAST FOR
NOW.
INTO WEDNESDAY...DRIER AIR WILL CONTINUE TO FILTER INTO THE REGION
AND START A WARMING TREND AFTER BOTTOMING OUT ON TUESDAY. THOUGH
WINDS BACK TO SOUTHWESTERLY ON WEDNESDAY...COLD FRONT IN WEDNESDAY
NIGHT/THURSDAY MORNING WILL USHER IN BREEZY NORTHERLY WINDS ONCE
AGAIN WITH YET COOLER AIR SURGING SOUTHWARD INTO FRIDAY WITH DRY
WEATHER TO PREVAIL.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 25 53 20 50 24 / 0 0 0 10 40
TULIA 28 57 26 51 26 / 10 0 0 10 40
PLAINVIEW 29 58 24 54 26 / 10 0 0 0 40
LEVELLAND 29 59 24 57 24 / 0 0 0 0 20
LUBBOCK 31 60 23 57 26 / 10 0 0 0 20
DENVER CITY 25 59 29 58 30 / 0 0 0 0 20
BROWNFIELD 29 60 24 59 28 / 0 0 0 0 20
CHILDRESS 36 65 26 56 27 / 50 0 0 0 40
SPUR 36 64 29 59 31 / 30 0 0 0 20
ASPERMONT 40 66 30 62 36 / 40 0 0 0 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33/23
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
540 PM CST SAT FEB 9 2013
.AVIATION...
GUSTY STRONG WINDS WILL BE THE MAIN CONCERN AT BOTH TERMINALS
THROUGH 1 OR 2Z...AFTER WHICH THE WINDS SHOULD DECREASE TO LESS
THAN ABOUT 18 KTS SUSTAINED. SOME LIGHT BLOWING DUST IS EXPECTED AT
KLBB THROUGH 1Z. ALSO...THERE IS A CHANCE OF TSRA IN THE VICINITY
OF KCDS THROUGH ABOUT 4Z. A FRONT WILL MOVE EAST ACROSS THE AREA
BEFORE MIDNIGHT BRINGING A WIND SHIFT FROM SW TO WEST BUT WITH NOT
MUCH CHANGE IN WIND SPEED GIVEN THE TIME OF DAY. SUNDAY
MORNING...THE WINDS WILL RAMP UP AGAIN AS STRONG W-NW WINDS ALOFT
MIX DOWN. SOME LIGHT BLOWING DUST WILL BE POSSIBLE AT LUBBOCK
AGAIN BY MIDDAY. THE WINDS WILL START TO DIMINISH SUNDAY
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 304 PM CST SAT FEB 9 2013/
SHORT TERM...
A BUSY AFTERNOON IS IN STORE FOR THE CWA... WITH BOTH HIGH WINDS IN THE
WEST AND THE POSSIBILITY FOR STORMS IN THE EAST. AS EXPECTED... A
POTENT TROUGH IS CURRENTLY ADVANCING ON WEST TEXAS... WITH A 500MB
KT MAX OF OVER 100KT CURRENTLY SITUATED OVER EASTERN NEW MEXICO.
HIGH CLOUDS HAVE CLEARED OVER MOST OF THE NW PORTION OF THE CWA AND
NEW MEXICO...ALLOWING FOR DEEP MIXING AND VERY STRONG WINDS ACROSS
MOST OF EASTERN NEW MEXICO. WINDS HAVE BEEN SLOW TO VEER IN WEST
TEXAS THIS AFTERNOON...ALLOWING DEWPOINTS TO CLIMB INTO THE UPPER
30S AND NEAR 40 ACROSS MOST OF THE CAPROCK AS OF 18Z. HOWEVER...
SURFACE OBS AND RADAR TRENDS ARE INDICATING THAT WINDS ARE FINALLY
BEGINNING TO VEER SLIGHTLY IN THE WEST... WHICH HAS RESULTED IN
RAPID DRYING AND INCREASING WIND SPEEDS JUST EAST OF THE TEXAS NEW
MEXICO BORDER. GIVEN THESE TRENDS... HAVE OPTED TO UPGRADE
PARMER...CASTRO AND BAILEY COUNTIES TO A HIGH WIND WARNING THROUGH
02Z. FIRE WEATHER CONCERNS ARE STILL MINIMAL... ESPECIALLY GIVEN
THE HIGHER THAN ANTICIPATED DEWPOINTS ACROSS THE WEST AND MOIST FUEL
CONDITIONS... HOWEVER ELEVATED FIRE WEATHER CONDITIONS AND SOME
RED FLAG MINUTES WILL BE PRESENT NEAR THE TX/NM BORDER THROUGH
THE EARLY EVENING WHERE THE AIR WILL BE DRIEST AND WINDS
STRONGEST.
FURTHER EAST... THE FORECAST STILL APPEARS TO BE LARGELY ON TRACK AS
MOISTURE CONTINUES TO RETURN ACROSS THE EAST. RADAR AND SURFACES
OBSERVATIONS INDICATE THE BEGINNINGS OF A DRYLINE FORMING JUST TO
THE EAST OF THE TX/NM STATE LINE...AND APPEARS TO BE SLOWLY
ADVANCING EAST. IN ADDITION... VISIBLE SATELLITE IMAGERY IS SHOWING
AN INCREASE IN CUMULIFORM CLOUDS JUST TO THE DRY SIDE OF THIS
DEVELOPING DRYLINE. DEWPOINTS AS OF 20Z HAVE REACHED THE UPPER 40S
ACROSS THE SOUTHEAST...TO NEAR 40 IN THE NORTHERN ROLLING
PLAINS...WHICH IS A BIT LOWER THAN YOU WOULD LIKE FOR STORM
DEVELOPMENT. AS SUCH... INSTABILITY IS STILL VERY WEAK ACROSS THE
AREA...WITH MAXIMUM VALUES OF NEAR 500 J/KG RESTRICTED TO THE
SOUTHEAST. THERE STILL REMAINS SOME TIME FOR MOISTURE TO
INCREASE...AND IT STILL SEEMS WITHIN REASON THAT DEWPOINTS WILL
REACH THE UPPER 40S TO LOW 50S WITHIN THE NEXT FEW HOURS. LOCAL
HIGH RESOLUTION MODELS...INCLUDING THE TTUWRF AND TO A LESSER EXTENT
THE HRRR... SEEM TO BE SUGGESTING THAT INITIATION MAY HOLD OFF UNTIL
00Z... HOWEVER THE RUC IS STILL FIRING AROUND 22Z. GIVEN CURRENT
TRENDS... IT SEEMS THAT THE LATER INITIATION SOLUTIONS SEEM MORE
PLAUSIBLE. GIVEN THE VERY STRONGLY SHEARED WIND FIELDS... ANY
STORMS THAT CAN MANAGE TO INITIATE EARLY WILL VERY LIKELY BE
SUPERCELLULAR... AND COULD POSE A VERY ISOLATED TORNADO THREAT IF
MOISTURE CAN CONTINUE TO RISE. HOWEVER...THIS THREAT APPEARS TO BE
VERY MARGINAL AT THIS TIME... AND A MORE LIKELY THREAT WILL BE
MARGINALLY SEVERE HAIL TO 1" AND DAMAGING WINDS TO 70 MPH. THE MOST
LIKELY AREA FOR INITIATION STILL APPEARS TO BE NORTH OF LBB AND
EASTWARD TOWARDS THE CHILDRESS AREA. LATER IN THE EVENING...A
PACIFIC FRONT WILL SWEEP THROUGH THE AREA...AND LIKELY INITIATE
MORE STORMS WITH A MORE LINEAR MODE. STORMS WILL LIKELY EXIT THE
AREA TO THE EAST BY 06Z.
FOR TOMORROW...BREEZY WESTERLY WINDS BETWEEN 20-30 MPH WILL PERSIST
ACROSS THE AREA DURING THE AFTERNOON...WHICH WHEN COMBINED WITH LOW DEWPOINTS
WILL RESULT IN ELEVATED FIRE WEATHER CONDITIONS....ESPECIALLY ACROSS
THE ROLLING PLAINS WHERE WARMER TEMPERATURES WILL RESULT IN LOWER RH
VALUES...
LONG TERM...
BY SUNDAY EVENING...FLOW ACROSS THE REGION WILL BE ZONAL TO SLIGHTLY
WEST SOUTHWESTERLY AS TODAY/S WIND MAKER EJECTS INTO THE GREAT
LAKES. TROUGH OUT WEST CONTINUES TO DEEPEN AND APPROACH LATE MONDAY
NIGHT. FLOW BECOMES NORTHWESTERLY BY WEDNESDAY WITH AN EMBEDDED
TROUGH DUE IN ON THURSDAY AND ANOTHER TROUGH DIGGING INTO THE
SOUTHWEST BY FRIDAY THOUGH MORE LATITUDINALLY ORIENTED THAN THE
EARLY WEEK SYSTEM. RIDGING BUILDS OUT WEST WITH STRONG NNW FLOW
WITH DECENT COLD AIR ADVECTION.
COLD FRONT SHOULD FINALLY MAKE IT INTO THE AREA SUNDAY EVENING WITH
WINDS BECOMING MORE OR LESS EASTERLY AND REMAINING IN FAVORABLE
UPSLOPE REGIME FOR MOISTURE ADVECTION. NAM/GFS/ECM HAVE COME INTO
GOOD AGREEMENT WITH SOME FAIRLY SUBSTANTIVE MOISTURE ADVECTION
MONDAY EVENING PERHAPS MAKING IT A BIT FURTHER WEST THAN EARLIER
THOUGHT. NEVERTHELESS...GENERAL TRENDS IN THE FORECAST REMAIN
INSOFAR AS MOISTURE GOES...BUT...WITH THE GREATER
MOISTURE...PRECIPITATION PHASE IS A BIT LESS CERTAIN WITH PHASE
REMAINING LIQUID UNTIL WRAP AROUND ON THE BACK SIDE OF THE
LOW...WITH LOWER TEMPS. GIVEN THIS FAIRLY RADICAL CHANGE THIS
RUN...WILL HOLD OFF ON MAKING MAJOR CHANGES TO ONGOING FORECAST FOR
NOW.
INTO WEDNESDAY...DRIER AIR WILL CONTINUE TO FILTER INTO THE REGION
AND START A WARMING TREND AFTER BOTTOMING OUT ON TUESDAY. THOUGH
WINDS BACK TO SOUTHWESTERLY ON WEDNESDAY...COLD FRONT IN WEDNESDAY
NIGHT/THURSDAY MORNING WILL USHER IN BREEZY NORTHERLY WINDS ONCE
AGAIN WITH YET COOLER AIR SURGING SOUTHWARD INTO FRIDAY WITH DRY
WEATHER TO PREVAIL.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 25 53 20 50 24 / 0 0 0 10 40
TULIA 28 57 26 51 26 / 10 0 0 10 40
PLAINVIEW 29 58 24 54 26 / 10 0 0 0 40
LEVELLAND 29 59 24 57 24 / 0 0 0 0 20
LUBBOCK 31 60 23 57 26 / 10 0 0 0 20
DENVER CITY 25 59 29 58 30 / 0 0 0 0 20
BROWNFIELD 29 60 24 59 28 / 0 0 0 0 20
CHILDRESS 36 65 26 56 27 / 50 0 0 0 40
SPUR 36 64 29 59 31 / 30 0 0 0 20
ASPERMONT 40 66 30 62 36 / 40 0 0 0 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 8 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ023-028-029-033>035-039-040.
HIGH WIND WARNING UNTIL 8 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ021-022-027.
&&
$$
33
AREA FORECAST DISCUSSION
NWS SPOKANE WA
420 AM PST Fri Feb 8 2013
.SYNOPSIS...
Light snow will linger through mid-morning over the central and
southern Idaho Panhandle. A drier weather pattern will arrive for
the weekend. The next storm system is expected to arrive on
Tuesday bringing an increased potential for rain and mountain
snow. Breezy conditions may also follow the passage of this storm
system Tuesday night into Wednesday.
&&
.DISCUSSION...
Today: We will be monitoring a decaying band of rain and snow over
Spokane, Kellogg, St. Maries and Winchester this morning.
Localized accumulations of 1 to 3 inches occurred overnight over
the Palouse and portions of Shoshone county with this deformation
band. A report of 5 inches came from the Moscow area at an elevation
of 3400 feet. Snow levels have generally been in the 2000-2500 ft
range. Radar trends between 11 PM and 2 AM show an overall decrease
in the organization and intensity of the precipitation within the
deformation band. It is likely undergoing a good deal of stretching
and shearing as the upper level trough digs into central California
this morning. The 06z NAM and recent runs of the HRRR seem to have a
good depiction of this band and suggest that it will linger over
Spokane, Kootenai, and Shoshone counties through about 9 AM. It is
doubtful that snow intensities will increase to what they were last
evening, but some accumulations of a half inch will be possible this
morning above 2000 feet. Early morning water vapor imagery shows a
weak shortwave over eastern Oregon moving to the northeast which may
enhance precipitation over southeast Washington and the
southern/central Panhandle early this morning.
By late morning, upper level high pressure overspreading northwest
Washington and southern British Columbia should bring drier air
into northern Washington. By afternoon, light northerly flow
should begin to erode clouds from north to south. The southern
Idaho Panhandle and the Palouse are often the last places to
experience clearing in weather patterns like this. It may be
evening before Lewiston and Pullman see much break in the
overcast. Central and northeast Washington should experience a
good deal of sunshine today.
Tonight and Saturday: Some low chances for precipitation have been
retained over the Idaho Panhandle for this evening and again on
Saturday. The models continue to advertise an upper level
disturbance descending into the Panhandle in the northerly flow.
Precipitation amounts (if anything occurs at all) should be light.
Model forecast soundings show marginal and shallow instability
over the Panhandle. The north/northwest flow suggests that
precipitation chances will be the greatest over the rising terrain
of southern Shoshone county and the Camas Prairie. It is hard to
get too excited about much accumulating snow since the model
soundings are quite dry in the dendritic layer (-10C to -20C).
Therefore precipitation chances around St Maries, Deary, Clarkia
and Winchester are 30 percent or less. /GKoch
Sunday through Thursday...An eastern Pacific Ridge between
130-140W will remain established through next week. On Sunday and
Monday the ridge briefly flattens and moves across the area.
Despite the ridge models show some mid and high clouds spilling
across the area and boundary layer moisture progs show only a
marginal fog threat mainly around Wenatchee, Moses Lake, and the
northern valleys. On Tuesday into Wednesday the GFS has trended
strongly towards the ECMWF solution with a trough dropping into
the region from the northwest with a strong cold front passage Tue
night into Wednesday. Westerly flow and limited moisture with the
front will likely keep areas in the lee of the Cascades dry, with
most of the precipitation with the front confined to the Cascade
crest, and Idaho Panhandle. Snow levels along and ahead of the
front will range from 2000-3000 feet...before falling Wednesday
night behind the front. Tightening surface pressure gradients with
the front along with 850mb winds of 30-50 knots will lead to at
least breezy conditions for much of the area. Precise timing of
front will dictate strength of winds as a day time passage would
give stronger winds with better mixing potential. For now just
trended the winds upward towards the 00z GFS solution. On
Thursday another weak disturbance dropping out of Canada will clip
North Idaho giving this area the best threat for snow showers. JW
&&
.AVIATION...
12Z TAFS: A band of light snow will linger in the Pullman, Spokane
and Coeur D`Alene areas through 15-17z. Little to no additional
accumulation is anticipated with this decaying deformation band.
With temperatures in the low 30s, runways should be wet. Dry air
should move in from the north today as the upper level ridge
amplifies over northern Washington and British Columbia. Look for
improving ceilings through the day. Pullman and Lewiston will
probably be the last airports to clear late in the afternoon or
early in the evening. /GKoch
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 38 23 35 22 34 22 / 20 0 0 0 0 0
Coeur d`Alene 38 24 35 20 35 22 / 40 0 10 0 0 0
Pullman 37 25 36 25 37 24 / 50 0 10 10 0 0
Lewiston 42 30 44 29 42 28 / 50 0 10 10 0 0
Colville 41 23 39 23 38 20 / 10 0 0 0 0 0
Sandpoint 38 25 35 23 35 25 / 20 0 10 0 0 10
Kellogg 42 24 37 23 39 24 / 70 0 20 20 0 0
Moses Lake 43 25 39 25 41 25 / 0 0 0 0 0 0
Wenatchee 42 25 37 26 40 26 / 0 0 0 0 0 0
Omak 38 21 32 22 35 21 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
255 AM PST Fri Feb 8 2013
.SYNOPSIS...
Light snow will linger through mid-morning over the central and
southern Idaho Panhandle. A drier weather pattern will arrive for
the weekend. The next storm system is expected to arrive on
Tuesday bringing an increased potential for rain and mountain
snow. Breezy conditions may also follow the passage of this storm
system Tuesday night into Wednesday.
&&
.DISCUSSION...
Today: We will be monitoring a decaying band of rain and snow over
Spokane, Kellogg, St. Maries and Winchester this morning.
Localized accumulations of 1 to 3 inches occurred overnight over
the Palouse and portions of Shoshone county with this deformation
band. Snow levels have generally been in the 2000-2500 ft range.
Radar trends between 11 PM and 2 AM show an overall decrease in
the organization and intensity of the precipitation within the
deformation band. It is likely undergoing a good deal of
stretching and shearing as the upper level trough digs into
central California this morning. The 06z NAM and recent runs of
the HRRR seem to have a good depiction of this band and suggest
that it will linger over Spokane, Kootenai, and Shoshone counties
through about 9 AM. It is doubtful that snow intensities will
increase to what they were last evening, but some accumulations of
a half inch will be possible this morning above 2000 feet. Early
morning water vapor imagery shows a weak shortwave over eastern
Oregon moving to the northeast which may enhance precipitation
over southeast Washington and the southern/central Panhandle early
this morning.
By late morning, upper level high pressure overspreading northwest
Washington and southern British Columbia should bring drier air
into northern Washington. By afternoon, light northerly flow
should begin to erode clouds from north to south. The southern
Idaho Panhandle and the Palouse are often the last places to
experience clearing in weather patterns like this. It may be
evening before Lewiston and Pullman see much break in the
overcast. Central and northeast Washington should experience a
good deal of sunshine today.
Tonight and Saturday: Some low chances for precipitation have been
retained over the Idaho Panhandle for this evening and again on
Saturday. The models continue to advertise an upper level
disturbance descending into the Panhandle in the northerly flow.
Precipitation amounts (if anything occurs at all) should be light.
Model forecast soundings show marginal and shallow instability
over the Panhandle. The north/northwest flow suggests that
precipitation chances will be the greatest over the rising terrain
of southern Shoshone county and the Camas Prairie. It is hard to
get too excited about much accumulating snow since the model
soundings are quite dry in the dendritic layer (-10C to -20C).
Therefore precipitation chances around St Maries, Deary, Clarkia
and Winchester are 30 percent or less. /GKoch
Sunday through Thursday...An eastern Pacific Ridge between
130-140W will remain established through next week. On Sunday and
Monday the ridge briefly flattens and moves across the area.
Despite the ridge models show some mid and high clouds spilling
across the area and boundary layer moisture progs show only a
marginal fog threat mainly around Wenatchee, Moses Lake, and the
northern valleys. On Tuesday into Wednesday the GFS has trended
strongly towards the ECMWF solution with a trough dropping into
the region from the northwest with a strong cold front passage Tue
night into Wednesday. Westerly flow and limited moisture with the
front will likely keep areas in the lee of the Cascades dry, with
most of the precipitation with the front confined to the Cascade
crest, and Idaho Panhandle. Snow levels along and ahead of the
front will range from 2000-3000 feet...before falling Wednesday
night behind the front. Tightening surface pressure gradients with
the front along with 850mb winds of 30-50 knots will lead to at
least breezy conditions for much of the area. Precise timing of
front will dictate strength of winds as a day time passage would
give stronger winds with better mixing potential. For now just
trended the winds upward towards the 00z GFS solution. On
Thursday another weak disturbance dropping out of Canada will clip
North Idaho giving this area the best threat for snow showers. JW
&&
.AVIATION...
06Z TAFS: Light to locally moderate pcpn across SE WA and the lower
ID Panhandle will weaken overnight but be slow fully clearout
until aft 12z per local HRRR guidance. Incr BL moisture frm the
pcpn event will lead to low fcst fg/stratus betwn KGEG-KLWS.
Confidence low due to poor model guidance of current pcpn
and dvlpng drier nrly flow. KLWS/KPUW will carry the highest
threat for cig/vis restrictions given the high pcpn amts that
have already fallen this evening. Otherwise...all sites should see
improving conditions aft 19z and achieve VFR status by the aftn hrs
of Friday. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 38 23 35 22 34 22 / 20 0 0 0 0 0
Coeur d`Alene 38 24 35 20 35 22 / 40 0 10 0 0 0
Pullman 37 25 36 25 37 24 / 50 0 10 10 0 0
Lewiston 42 30 44 29 42 28 / 50 0 10 10 0 0
Colville 41 23 39 23 38 20 / 10 0 0 0 0 0
Sandpoint 38 25 35 23 35 25 / 20 0 10 0 0 10
Kellogg 42 24 37 23 39 24 / 70 0 20 20 0 0
Moses Lake 43 25 39 25 41 25 / 0 0 0 0 0 0
Wenatchee 42 25 37 26 40 26 / 0 0 0 0 0 0
Omak 38 21 32 22 35 21 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1015 PM PST Thu Feb 7 2013
.SYNOPSIS...
A weakening frontal system will bring a mix of rain and snow to
the Inland Northwest. The best chance for accumulating snow will
be above 2500 feet tonight. A ridge of high pressure will build
back into the region over the weekend and bring a drying trend,
but also a good chance for fog and low clouds. No big storm
systems are anticipated through early next week.
&&
.DISCUSSION...
Evening Update: Update for this evening to increase snow amounts
for the WA and ID Palouse and portions of the lower ID Panhandle
mainly south of I-90 toward the Camas Prairie.
A persistent deformation axis on the northwestern quadrant of a
700mb vort max that is crossing from NE Oregon...N/NE toward the
Camas Prairie has resulted in several hours of light to moderate
pcpn across the WA/ID Palouse...Blue Mtns...Camas Prairie...and
Central Panhandle Mtns which is mainly in the form of snow above
2300 feet and rain/snow below. Additionally...steepening lapse
rates under a -31C 500mb cold pool and midlevel convergence due to
NW flow wrapping in from the backside of the low has resulted in
an enhanced band of pcpn from Pullman toward the Spokane Area.
Snowfall amounts so far in Pullman have been around 3/4 to one
inch and the potential exist for at least another inch with this
wave before weakening overnight. The light snow accumulations will
also be found across a majority of the Idaho Panhandle south of
I-90 to the Camas Prairie with snow levels generally around 2300
feet and this is confirmed by numerous CAMS along state highway
2...6...and US 95. Models are not handling the westward extent of
the pcpn exceptionally well and we generally referenced the
HRRR/Satellite/Radar for the evening update. This wave is
disconnected from the main jet stream axis which explains its slow
movement but should also support the NAM/GFS solutions of
weakening over the next few hours.
What is a concern is a second wave upstream wave tracking into Ern
Oregon in which no models are handling well. The main low is
expected to continue to sag into California and pull this wave
south with it but given the performance of tonight`s wave, it is
not a sure bet and we increased pops across the southeast through
the remainder of the night. /sb
&&
.AVIATION...
06Z TAFS: Light to locally moderate pcpn across SE WA and the lower
ID Panhandle will weaken overnight but be slow fully clearout
until aft 12z per local HRRR guidance. Incr BL moisture frm the
pcpn event will lead to low fcst fg/stratus betwn KGEG-KLWS.
Confidence low due to poor model guidance of current pcpn
and dvlpng drier nrly flow. KLWS/KPUW will carry the highest
threat for cig/vis restrictions given the high pcpn amts that
have already fallen this evening. Otherwise...all sites should see
improving conditions aft 19z and achieve VFR status by the aftn hrs
of Friday. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 27 36 23 35 22 34 / 100 10 0 0 0 0
Coeur d`Alene 28 36 24 35 20 35 / 90 10 0 10 0 0
Pullman 28 36 25 36 25 37 / 100 20 0 10 10 0
Lewiston 31 44 30 44 29 43 / 100 40 0 10 10 0
Colville 27 39 23 39 23 38 / 30 10 0 0 0 0
Sandpoint 27 36 25 35 23 35 / 50 10 0 10 0 0
Kellogg 28 38 24 37 23 39 / 100 40 0 20 10 0
Moses Lake 24 40 25 39 25 39 / 10 10 0 0 0 0
Wenatchee 25 38 25 37 26 37 / 10 10 0 0 0 0
Omak 19 33 21 32 22 31 / 10 10 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
849 PM CST SAT FEB 9 2013
.SHORT TERM...TONIGHT INTO SUNDAY
849 PM CST SAT FEB 9 2013
MAIN FOCUS THIS EVENING IS ON THE PRECIPITATION TYPE TRENDS GOING
INTO THE OVERNIGHT HOURS AND SUNDAY MORNING. BASED ON THE LATEST 6
HOURS OR SO OF RAP SOUNDINGS AND THE LATEST 10.00Z NAM
SOUNDINGS...WILL BE MAKING SOME ADJUSTMENTS TO THE PRECIPITATION
TYPES DUE TO WARM LAYER TEMPERATURES NOT LOOKING AS WARM ACROSS
SOUTHEAST MINNESOTA AND WEST CENTRAL WISCONSIN.
IN SE MN/WC WI... THE 10.01Z RAP AND 10.00Z NAM BUFKIT SOUNDINGS
SUGGEST THAT THE WARM LAYER DOES NOT GET MUCH ABOVE THE 0-2C RANGE
UNTIL AFTER 12Z SUNDAY. TOP DOWN APPROACH SAYS THAT THE THE MAIN
PRECIPITATION TYPES WOULD BE SNOW AND SLEET STARTING TONIGHT
BETWEEN 6-12Z. THEREFORE...WILL BE BUMPING UP THESE TOTALS A LITTLE
BIT FOR THE OVERNIGHT PERIOD.
THE THREAT FOR FREEZING RAIN LOOKS TO BE THE HIGHEST ACROSS
NORTHEAST IOWA AND SOUTHWEST WISCONSIN WHERE THE WARM LAYER GETS
INTO THE +3 TO +6C RANGE QUICKER THAN AREAS TO THE NORTH.
HOWEVER...SURFACE TEMPERATURES ARE ALREADY HOVERING AROUND 30-32F
IN THIS AREA...SO IMPACT MAY NOT BE TOO SIGNIFICANT THERE. AS THE
RAIN/PRECIPITATION STARTS TO FALL...LATENT HEAT RELEASE WILL HELP
TO PUSH THESE TEMPERATURES UP A FEW DEGREES AND THE SOUTHERLY WARM
AIR ADVECTION WILL ALSO HELP TO KEEP TEMPERATURES ON A WARMING
TREND OVERNIGHT INTO TOMORROW. THIS MEANS THAT THE PERIOD OF
FREEZING RAIN WILL LIKELY BE BRIEF BEFORE IT GOES TO JUST REGULAR
RAIN.
OTHERWISE...THE TIMING OF THE SYSTEM STILL LOOKS ON TRACK WITH THE
LAYOUT OF THE ADVISORIES AND WITH THE MIX OF PRECIPITATION
TYPES...A WINTER WEATHER ADVISORY STILL LOOKS LIKE THE WAY TO GO
FOR SOME OF THE SLICK SPOTS THAT WILL LIKELY FORM ON UNTREATED
ROADS/SURFACES. THERE HAVE BEEN A FEW THUNDERSTORMS NOTED FROM
NORTHWEST MISSOURI INTO EASTERN SOUTH DAKOTA THIS EVENING OUT IN
THE LEADING PRECIPITATION BAND...BUT CONFIDENCE IS NOT HIGH ENOUGH
THAT THESE WILL OCCUR INTO THE UPPER MISSISSIPPI RIVER VALLEY AS
10.01Z RAP 0-6KM MUCAPE REMAINS LESS THAN 100 J/KG THROUGH
TOMORROW MORNING. STILL WOULD NOT BE SURPRISED TO HAVE SOME
THUNDERSLEET OCCUR OVERNIGHT INTO TOMORROW MORNING GIVEN THE LARGE
SCALE LIFT ASSOCIATED WITH THIS SYSTEM.
.LONG TERM...TUESDAY THROUGH SATURDAY
238 PM CST SAT FEB 9 2013
NORTHWEST FLOW WILL SET UP BEHIND THE DEPARTING STORM SYSTEM
MONDAY. THIS WILL ALLOW A SYSTEM TO DROP INTO THE UPPER MIDWEST
THURSDAY. SOME DIFFERENCE ON HOW LONG THE LONG WAVE TROUGH WILL BE
OVER THE UPPER MIDWEST AS THE 09.12Z ECMWF AND GEM HOLD ONTO IT AS
IT CONNECTS TO ENERGY DROPPING INTO THE DESERT SOUTHWEST WHILE THE
GFS IS A LITTLE MORE PROGRESSIVE. VERY LITTLE TIME SPENT
DIAGNOSING THIS SYSTEM SO WILL LET THE MODEL CONSENSUS GRIDS RIDE
WITH A CHANCE OF PRECIPITATION FROM THURSDAY INTO FRIDAY OR
FRIDAY NIGHT.
&&
.AVIATION...TONIGHT AND SUNDAY
548 PM CST SAT FEB 9 2013
MVFR TO LIFR CONDITIONS ARE ALREADY IN PLACE ACROSS THE REGION
WITH THE SUB-IFR CONDITIONS MAINLY WEST OF THE MISSISSIPPI RIVER.
WITH LOW LEVEL MOISTURE FLOW INCREASING THROUGH THE NIGHT...DO NOT
THINK THAT CONDITIONS WILL IMPROVE MUCH DESPITE THERE BEING SOME
CLEARING ACROSS SOUTHWEST IOWA. CONDITIONS WILL CONTINUE TO
DETERIORATE AT BOTH LSE/RST OVERNIGHT INTO TOMORROW MORNING AS
THE NEXT SYSTEM MOVES INTO THE AREA WITH MIXED PRECIPITATION TYPES
EXPECTED AT THE ONSET. USED FORECAST SOUNDINGS FROM THE 09.22Z RAP
AND 09.18Z NAM/GFS TO GET AND GET SOME TIMING INVOLVED BETWEEN THE
DIFFERENT P-TYPES WITH IT. EXPECT IN TO BE A SNOW/SLEET MIX TO
BEGIN BEFORE CHANGING TO A SLEET/FREEZING RAIN MIX AND FINALLY TO
ALL RAIN BY AFTERNOON. FOG WILL LIKELY FORM AS A RESULT OF THE
HIGH LOW LEVEL MOISTURE AND WARMER TEMPERATURES HELPING TO MELT
SOME OF THE SNOW DOWN. WINDS WILL ALSO BE ON THE INCREASE TOMORROW
MORNING WITH GUSTS IN THE 20-25KT RANGE IN THE MORNING/EARLY
AFTERNOON.
&&
.HYDROLOGY...
238 PM CST SAT FEB 9 2013
RAINFALL FROM THE SYSTEM TONIGHT THROUGH SUNDAY COULD POSE SOME
PROBLEMS FOR AREA STREAMS. THE GROUND IS FROZEN SO RUNOFF WILL NOT
BE ABLE TO GO INTO THE GROUND AND WILL QUICKLY FIND ITS WAY INTO
THE STREAMS. NOT EXPECTING HUGE AMOUNTS OF QPF...SO WOULD
PRIMARILY THINK IN BANK RISES WOULD OCCUR. HOWEVER...SOME
LOCALIZED HIGHER QPF AMOUNTS COULD LEAD TO MINOR FLOODING OF
SMALLER STREAMS ALONG WITH SOME ICE JAM POTENTIAL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
238 PM CST SAT FEB 9 2013
WI...WINTER WEATHER ADVISORY FROM 3 AM TO NOON CST SUNDAY FOR
WIZ032>034-041-042-053>055-061.
WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST SUNDAY FOR WIZ017-
029-043-044.
MN...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST SUNDAY
FOR MNZ086-087-094-095.
WINTER WEATHER ADVISORY FROM 3 AM TO NOON CST SUNDAY FOR MNZ079-
088-096.
IA...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST SUNDAY
FOR IAZ008>010-018-019-029.
WINTER WEATHER ADVISORY FROM 3 AM TO NOON CST SUNDAY FOR IAZ011-
030.
&&
$$
SHORT TERM...HALBACH
LONG TERM...04
AVIATION...HALBACH
HYDROLOGY....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
315 PM CST FRI FEB 8 2013
.SHORT TERM...TONIGHT THROUGH MONDAY
315 PM CST FRI FEB 8 2013
SURFACE MAP HAS A RIDGE OF HIGH PRESSURE EXTENDING FROM HUDSON BAY
INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION. DRY FEED OF
AIR/SUBSIDENCE UNDER THE RIDGE WAS ERODING STRATUS DECK TO THE
SOUTHWEST AND WAS NOW CONFINED ACROSS PORTIONS OF SOUTHEAST MN AND
NORTHEAST IA. MEANWHILE...TEMPERATURES THIS AFTERNOON WERE SITTING
RIGHT AROUND NORMAL IN THE MIDDLE AND UPPER 20S.
08.12Z MODELS IN PRETTY DECENT AGREEMENT WITH THE TRACK OF THE STORM
SYSTEM AFFECTING THE AREA THIS WEEKEND. NAM SEEMS TO BE A BIT
FARTHER NORTH WITH THE TRACK. GENERALLY TOOK A CONSENSUS OF THE
MODELS.
STRATUS WILL BE PROBLEMATIC OVERNIGHT INTO SATURDAY. WITH THE RIDGE
AXIS MOVING EAST OF THE AREA OVERNIGHT/SATURDAY MORNING...WINDS WILL
SWING BACK TO THE SOUTH WHICH WILL ADVECT STRATUS BACK INTO THE
AREA. NAM 0-5KM RH FIELD SHOWS THIS TREND. HAVE ADDED A MENTION OF
FOG ALONG AND EAST OF THE MISSISSIPPI RIVER FROM LATER THIS EVENING
THROUGH SATURDAY MORNING WHERE IT WILL BE CALMER CLOSER TO THE RIDGE
AXIS LEADING TO A RAPID TEMPERATURE DROP OFF. HRRR MODEL SUGGESTS
THAT THIS FOG COULD GET LOCALLY DENSE WITH VSBY UNDER A 1/4 MILE.
OTHER MODELS ARE NOT AS RAMBUNCTIOUS. WILL HAVE TO KEEP A CLOSE EYE
ON THIS. DURING THE DAY SATURDAY... EXPECTING INCREASING SOUTHERLY
FLOW TO ADVECT MORE LOW LEVEL MOISTURE INTO THE AREA LEADING TO
CONTINUED STRATUS DEVELOPMENT. AT THE SAME TIME...INCREASING FLOW
MAY ACTUALLY HELP TO MIX THIS MOISTURE FOR SOME PARTIAL SUNSHINE
FROM TIME TO TIME. OTHERWISE...LOOK FOR TEMPERATURES TO WARM INTO
THE 30 TO 35 DEGREE RANGE.
ATTENTION THEN TURNS TO A STRONG STORM SYSTEM HEADING OUT OF THE
COLORADO ROCKIES INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION
LATER SATURDAY NIGHT THROUGH SUNDAY. THIS SYSTEM PROMISES A WINTRY
MIX FOR THE AREA...STARTING OFF IN THE VERY EARLY MORNING HOURS OF
SUNDAY AND ALONG/WEST OF THE MISSISSIPPI RIVER AS A SLEET/FREEZING
RAIN MIX...SPREADING EAST OF THE RIVER BY DAY BREAK. WITH DECENT
SURGE OF PRECIPITABLE WATER...THERE IS THE POTENTIAL FOR 1/10 TO
2/10 INCH OF ICE ACCUMULATION BEFORE TRANSITIONING TO RAIN BY LATER
SUNDAY MORNING/SUNDAY AFTERNOON AS WARM/MOIST AIR CONVEYOR BELT
WRAPS INTO THE AREA. THE EXCEPTION FOR A TOTAL TRANSITION TO RAIN
MAY BE ACROSS NORTH CENTRAL WI/TAYLOR COUNTY WHERE A MIX MAY HANG
AROUND LATER. OTHERWISE...LOOKING FOR A FAIRLY HEFTY AMOUNT OF
RAINFALL THROUGH THE DAY SUNDAY EXPECTED TO BE IN THE WITH 1/4 TO
1/2 INCH RANGE. THIS MAY LEAD TO SOME HYDROLOGY ISSUES WHICH IS
TALKED ABOUT BELOW IN THE HYDROLOGY SECTION.
AS THE STORM SYSTEM SWINGS NORTHEAST INTO EAST-CENTRAL MN/NORTHWEST
WI SUNDAY EVENING...LOOKING FOR A DRY SLOT TO WORK INTO THE
AREA...LEADING TO A DIMINISHING RAIN AND INTO A MORE DRIZZLE
SCENARIO EARLY IN THE EVENING...THEN A SWITCHING TO A LIGHT
SNOW/CHANCE OF DRIZZLE/FREEZING DRIZZLE SCENARIO IN THE LATE EVENING
AND OVERNIGHT AS COLDER AIR FILTERS IN UNDER THE LOW.
PLAN ON LINGERING DEFORMATION BAND LIGHT SNOW ON MONDAY AS THE LOW
PULLS OFF INTO ONTARIO. AT THIS POINT...LOOKS LIKE PERHAPS AN INCH
OF ACCUMULATION CAN BE EXPECTED MAINLY ALONG AND NORTH OF
I-90.
THIS STORM SYSTEM IS EXPECTED TO PRODUCE QUITE A WINTRY MIX AND
WILL DEFINITELY HAVE AN IMPACT ON THE REGION WITH THE BIGGEST
CONCERN BEING THE FREEZING RAIN/SLEET ACCUMULATIONS LATE SATURDAY
NIGHT INTO SUNDAY MORNING. FEELING IS THAT A WINTER WEATHER ADVISORY
WILL BE NEEDED AND WILL PASS THIS CONCERN ONTO THE NIGHT SHIFT FOR
FURTHER ASSESSMENT.
.LONG TERM...TUESDAY THROUGH FRIDAY
315 PM CST FRI FEB 8 2013
MAIN FORECAST CONCERN IS PRECIPITATION CHANCES THURSDAY INTO FRIDAY.
THE 08.12Z GFS/GEM/ECMWF ARE IN AGREEMENT IN DIGGING UPPER LEVEL
TROUGH OVER THE UPPER GREAT LAKES REGION THROUGH THE FORECAST
PERIOD. THE MAIN DIFFERENCES BETWEEN THE MODELS ARE TIMING AND
STRENGTH OF SHORTWAVE TROUGH MOVING INTO THE UPPER MIDWEST AND
NORTHERN PLAINS WEDNESDAY NIGHT INTO FRIDAY...AS THE 08.12Z
ECMWF/GFS ARE MUCH MORE PROGRESSIVE THAN THE 08.12Z GEM.
HOWEVER...ALL THE DETERMINISTIC MODELS SUGGEST DECENT LIFT AND
SATURATION IN ASSOCIATION WITH SHORTWAVE TROUGH AND WILL INCREASE
CHANCES OF PRECIPITATION FOR THURSDAY INTO FRIDAY. THE 08.12Z
GFS/ECMWF INDICATE WARMER AIR FILTERING AHEAD OF THE SHORTWAVE
TROUGH AND CAUSE PRECIPITATION TYPE CONCERNS DURING THE DAY
THURSDAY...ESPECIALLY OVER THE SOUTHERN PARTS OF THE FORECAST AREA.
HAVE INTRODUCED RAIN AND SNOW MIX OVER THE SOUTHERN PORTIONS OF THE
FORECAST AREA. PRECIPITATION SHOULD BE ALL SNOW OVER THE NORTHERN
PORTIONS OF THE FORECAST AREA.
&&
.AVIATION...THROUGH 18Z SATURDAY
1031 AM CST FRI FEB 8 2013
MVFR STRATUS DECK IS JUST ABOUT TO CLEAR KLSE...LIKELY BY 17Z.
KRST ON THE OTHER HAND DOES NOT LOOK AS LIKELY TO CLEAR AS
PREVIOUSLY FORECAST. WINDS IN THE STRATUS LAYER ARE TURNING
EASTERLY...AND BY 21Z WILL BE SOUTHEASTERLY. AS SUCH...THE
CLEARING LINE MAY JUST GET TO KRST...THEN THE STRATUS WILL START
MOVING BACK IN. AMENDED THE TAF TO INCLUDE A PERIOD OF SCATTERED
CONDITIONS BETWEEN 18-21Z...THE MOST LIKELY TIME WHEN PARTIAL
CLEARING WOULD OCCUR. THE STRATUS LAYER WINDS WILL GRADUALLY TURN
TO THE SOUTH AND SOUTHWEST TONIGHT AS HIGH PRESSURE CURRENTLY OVER
THE AREA HEADS OFF TO THE EAST. THEY WILL ALSO INCREASE...ALLOWING
THE STRATUS TO MOVE BACK INTO KLSE...SOMETIME BETWEEN 06-09Z. ONE
OF THE BIG QUESTIONS IS IF THE BASE OF THE STRATUS LAYER WILL
LOWER DUE TO NOCTURNAL COOLING. MODEL SOUNDINGS SEEM TO SUGGEST
THAT...THUS HAVE PUT IN SOME IFR CONDITIONS AT LEAST AT KRST LATE
IN THE NIGHT. CERTAINLY CANNOT RULE OUT LOWER CEILINGS...BUT
CONFIDENCE IS NOT HIGH ENOUGH TO GO ANY LOWER THAN IFR AT THIS
TIME. EXPECTING THE STRATUS DECK TO STICK AROUND MUCH OF SATURDAY
MORNING AT BOTH TAF SITES. THERE COULD BE SOME CLEARING FROM THE
SOUTHWEST APPROACHING THE TAF SITES TOWARDS 18Z...THOUGH.
ONLY OTHER ISSUE IS WINDS...WHICH SHOULD GRADUALLY PICK UP OUT OF
THE SOUTHEAST TONIGHT. MAY SEE SOME GUSTS UPWARDS OF 20 KT AT KRST
SATURDAY MORNING.
&&
.HYDROLOGY...
315 PM CST FRI FEB 8 2013
EXPECTING RAINFALL AMOUNTS OF AROUND 1/2 INCH TO FALL ON EXISTING
SNOWPACK AND FROZEN GROUNDS SUNDAY. THIS WILL LIKELY RESULT IN
RUNOFF INTO AREA STREAMS...CREEKS AND RIVERS. AS A RESULT...PLAN FOR
RISES ON AREA RIVER WAYS. IF RAINFALL SHOULD BECOME MORE
SIGNIFICANT...RIVER FLOODING WILL BECOME AN INCREASING CONCERN. THE
POSSIBILITY FOR ICE JAMS WILL ALSO HAVE TO BE MONITORED. IN
ADDITION...LOCALIZED SIGNIFICANT PONDING OF WATER CAN BE EXPECTED ON
AREA ROADWAYS WHERE DRAINAGE IN CONSTRICTED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 PM CST FRI FEB 8 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DTJ
AVIATION...AJ
HYDROLOGY....DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1031 AM CST FRI FEB 8 2013
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
1031 AM CST FRI FEB 8 2013
1031 AM UPDATE...STRATUS DECK CONTINUES TO GRADUALLY CLEAR
NORTHEAST TO SOUTHWEST ACROSS THE FORECAST AREA THIS MORNING.
HOWEVER...THE WIND FLOW IN THE STRATUS DECK IS BEGINNING TO TURN
EASTERLY AND WILL TURN SOUTHEAST BY 00Z. 12Z DVN SOUNDING SHOWED
THAT THE STRATUS DECK WAS QUITE THICK...ABOUT 3000 FEET COVERING
THE LAYER BETWEEN 925-850MB. THUS...A PESSIMISTIC FORECAST SEEMS
IN ORDER IN HANDLING THE STRATUS. 08.12/13Z HRRR AND RAP RUNS
SUGGEST THE CLOUD DECK WILL HANG UP OVER MUCH OF SOUTHEAST
MINNESOTA AND NORTHEAST IOWA THIS AFTERNOON...THEN JUST GET STUCK
THERE FOR TONIGHT. THE CLOUDS THEN EXPAND NORTHEASTWARD LATER
TONIGHT INTO SATURDAY AS THE 925MB WINDS PICK UP OUT OF THE SOUTH
AND EVENTUALLY SOUTHWEST WITH THE SURFACE HIGH PRESSURE AREA
DEPARTING. AS SUCH...HAVE GREATLY INCREASED CLOUD COVER WEST OF
THE MISSISSIPPI RIVER THROUGH TONIGHT...SPREADING IT EASTWARD LATE
TONIGHT INTO SATURDAY MORNING. ADJUSTED THE DIURNAL TEMPERATURE
CURVE TO FIT THIS IDEA AS WELL. ON A SIDE NOTE...MAY HAVE TO ADD
SOME PATCHY FOG TO CENTRAL WISCONSIN AREAS SINCE THEY WILL BE
CLEAR WITH LIGHT WINDS THIS EVENING...ALLOWING FOR A RAPID
TEMPERATURE DROP-OFF.
PREVIOUS DISCUSSION ISSUED AT 300 AM...
COMPLEX...STRONG STORM SYSTEM TO IMPACT THE REGION ON SUNDAY WITH
MIXED PRECIPITATION...RAIN...FLOODING POTENTIAL...ICE POSSIBLE.
AN UPPER LEVEL SHORTWAVE TROUGH WAS MOVING ONTO THE WEST COAST EARLY
THIS MORNING...PER THE LATEST WATER VAPOR SATELLITE IMAGERY. A CLOSED
LOW WILL DEVELOP WITH THE TROUGH...WHICH TAKES ON A NEGATIVE
TILT/STRENGTHENS AS IT MOVES ACROSS THE PLAINS TO ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY ON SUNDAY.
THIS STORM SYSTEM CAN BE BROKEN DOWN INTO THREE PARTS - THE
INITIAL WAVE OF PCPN ASSOCIATED WITH STRONG THERMODYNAMICS/SLOPING
FRONTOGENETICS...DRY SLOT BEHIND THIS REGION REMOVING ICE FROM THE
CLOUD...THEN THE DEFORMATION/COLD AIR ADVECTIVE REGION THAT WILL
LIKELY BE SNOW.
STRONG PUSH OF LOW LEVEL THERMODYNAMICS EVIDENCED VIA WARM AIR
ADVECTION AND THE 280-295K SFCS...MAXED OVER THE FORECAST AREA
BETWEEN 12Z SUN-00Z MON. SOUTHWEST-NORTHEAST RUNNING X-SECTION SHOWS
A STRONG NEARLY UPRIGHT FRONTOGENETIC RESPONSE ON THE LEADING EDGE
OF THE LOW LEVEL WARMING...WITH A 55 KT 850 MB JET DRIVING NORTHWARD
THROUGH THE AREA ON SUNDAY MORNING. THE NAM12 POINTS TO A BAND OF
PCPN DEVELOPING WITHIN THIS REGION...BUT THE MAIN BAND OF PCPN WITH
THE NAM/GFS/EC MOVES IN FOR THE LATE MORNING/AFTERNOON OF SUNDAY.
TIMING OF THE PCPN IS SIGNIFICANT AS WARMING AT THE SFC AND A LOFT
WILL OCCUR THROUGH THE DAY. BUFKIT SOUNDINGS POINT TO PARTIAL/FULL
MELTING AS THE PCPN MOVES IN...SO WHAT WOULD FALL WILL LIKELY BE
LIQUID. EARLY MORNING TEMPS WILL BE NEAR FREEZING...BUT ARE EXPECTED
TO WARM. HOWEVER...MORE IMPORTANTLY WILL BE ROAD TEMPS...AND THOSE
ARE CURRENTLY IN THE MID/UPPER 20S. SO...RAIN FALLING AT 36 OR SO
WOULD STILL BE ABLE TO FREEZE ON UNTREATED ROADS AND OTHER SFCS.
THIS BRINGS A REAL THREAT FOR FREEZING RAIN SUNDAY MORNING AS A
RESULT. UNSURE IF THIS THREAT WOULD CONTINUE INTO THE
AFTERNOON...AND HAVE OPTED TO TURN OVER TO JUST RAIN FOR THAT
PERIOD.
BEHIND THIS WAVE OF PCPN COMES A MID LEVEL DRY SLOT. THIS INTRUSION
OF DRIER AIR WILL REMOVE MUCH OF THE ICE BEARING PORTIONS OF THE
CLOUD...LEAVING THE LINGERING ISENTROPIC LIFT TO PRODUCE SOME
DRIZZLE. THE 00Z MODELS FAVOR A MOSTLY EVENING TIME FRAME FOR THIS.
AS THE STORM LIFTS NORTHEAST TOWARD THE NORTHERN GREAT LAKES SUNDAY
NIGHT...A COLD FRONT WILL SLIDE WEST-EAST ACROSS THE FORECAST AREA.
ALONG WITH COLDER AIR...THE SATURATION DEEPENS AGAIN...WITH ICE NOW
PART OF THE PCPN EQUATION. WHILE THE MAIN DEFORMATION AREA WOULD
STAY WELL NORTH OF THE FORECAST AREA //IF IT KEEPS ITS CURRENT
FORECASTED TRACK//...THERE WOULD BE SOME BITS OF UPPER LEVEL ENERGY
THAT WOULD RESULT IN AREAS OF LIGHT SNOW. THIS WOULD CONTINUE INTO
MONDAY...WITH THE BETTER CHANCES ACROSS THE NORTH.
THIS STORM WILL BRING VARIOUS WEATHER TYPES THAT WILL HAVE AN IMPACT
ON THE REGION. EXACT TRACK...TIMING AND TEMPERATURE PROFILE MAKES
REFINING WHERE AND HOW MUCH DIFFICULT. CURRENTLY SEE THE THREAT FOR
SOME ICE EARLY ON SUNDAY AS THE BIGGEST CONCERN FOR THE FORECAST
AREA...BUT HESITANT TO ISSUE A WINTER STORM WATCH AT THIS TIME.
FURTHER EVALUATION LATER TODAY MAY NECESSITATE ONE. DO BELIEVE SOME
HEADLINES WILL BE REQUIRED FOR SUNDAY...WHETHER IT STARTS AS A WATCH
OR ENDS UP AS AN ADVISORY.
.LONG TERM...MONDAY THROUGH THURSDAY
300 AM CST FRI FEB 8 2013
LIGHT SNOW WILL BE LINGERING MONDAY...ON THE BACKSIDE OF THE
DEPARTING STORM SYSTEM. INVERTED TROUGH AND SOME UPPER LEVEL ENERGY
WILL HELP SPARK THE LIGHT SNOW...WITH POSSIBLY ANOTHER INCH OF
ACCUMULATION. THE GFS AND ECMWF THEN AGREE ON A COUPLE QUIET DAYS
FOR TUE/WED...BUT THEN BRING AN UPPER LEVEL SHORTWAVE ACROSS THE
REGION WED NIGHT/THU NIGHT. DIFFERENCES IN THE TIMING AND
PLACEMENT...WITH THE GFS FASTER AND MORE NORTH WITH ITS SFC LOW. IT
KEEPS MOST OF ITS QPF NORTH OF THE FORECAST AREA. THE EC/S MORE
SOUTH AND SLOWER SOLUTION WOULD BRING LIGHT SNOW IN FOR THU
NIGHT/FRI...WITH SOME ACCUMULATIONS LIKELY. MODEL DIFFERENCES LOWERS
CONFIDENCE...SO WILL OPT FOR CONSENSUS AT THIS TIME.
&&
.AVIATION...THROUGH 18Z SATURDAY
1031 AM CST FRI FEB 8 2013
MVFR STRATUS DECK IS JUST ABOUT TO CLEAR KLSE...LIKELY BY 17Z.
KRST ON THE OTHER HAND DOES NOT LOOK AS LIKELY TO CLEAR AS
PREVIOUSLY FORECAST. WINDS IN THE STRATUS LAYER ARE TURNING
EASTERLY...AND BY 21Z WILL BE SOUTHEASTERLY. AS SUCH...THE
CLEARING LINE MAY JUST GET TO KRST...THEN THE STRATUS WILL START
MOVING BACK IN. AMENDED THE TAF TO INCLUDE A PERIOD OF SCATTERED
CONDITIONS BETWEEN 18-21Z...THE MOST LIKELY TIME WHEN PARTIAL
CLEARING WOULD OCCUR. THE STRATUS LAYER WINDS WILL GRADUALLY TURN
TO THE SOUTH AND SOUTHWEST TONIGHT AS HIGH PRESSURE CURRENTLY OVER
THE AREA HEADS OFF TO THE EAST. THEY WILL ALSO INCREASE...ALLOWING
THE STRATUS TO MOVE BACK INTO KLSE...SOMETIME BETWEEN 06-09Z. ONE
OF THE BIG QUESTIONS IS IF THE BASE OF THE STRATUS LAYER WILL
LOWER DUE TO NOCTURNAL COOLING. MODEL SOUNDINGS SEEM TO SUGGEST
THAT...THUS HAVE PUT IN SOME IFR CONDITIONS AT LEAST AT KRST LATE
IN THE NIGHT. CERTAINLY CANNOT RULE OUT LOWER CEILINGS...BUT
CONFIDENCE IS NOT HIGH ENOUGH TO GO ANY LOWER THAN IFR AT THIS
TIME. EXPECTING THE STRATUS DECK TO STICK AROUND MUCH OF SATURDAY
MORNING AT BOTH TAF SITES. THERE COULD BE SOME CLEARING FROM THE
SOUTHWEST APPROACHING THE TAF SITES TOWARDS 18Z...THOUGH.
ONLY OTHER ISSUE IS WINDS...WHICH SHOULD GRADUALLY PICK UP OUT OF
THE SOUTHEAST TONIGHT. MAY SEE SOME GUSTS UPWARDS OF 20 KT AT KRST
SATURDAY MORNING.
&&
.HYDROLOGY...
300 AM CST FRI FEB 8 2013
RAINFALL UPON SNOWPACK AND FROZEN GROUNDS WILL RESULT IN NEARLY FULL
RUNOFF INTO AREA STREAMS...CREEKS AND RIVERS ON SUNDAY. AT THIS
MOMENT...RAINFALL AMOUNTS FROM 1/4 TO 3/4 OF AN INCH ARE
EXPECTED...WITH SNOW WATER EQUIVALENT IN THE SNOW PACK FROM 1/2 TO 1
INCH. THIS SHOULD RESULT IN SOME RISES ON AREA RIVER WAYS. IF
RAINFALL SHOULD BE MORE SIGNIFICANT...RIVER FLOODING BECOMES A
GREATER CONCERN. THE POSSIBILITY FOR ICE JAMS WILL ALSO HAVE TO BE
MONITORED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 AM CST FRI FEB 8 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK/AJ
LONG TERM....RIECK
AVIATION...AJ
HYDROLOGY....RIECK
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1053 PM MST SAT FEB 9 2013
.UPDATE AND CORRECTION...
&&
.SHORT TERM...THE UPPER TROUGH OVER WESTERN COLORADO EARLIER
TODAY JUMPED THE DIVIDE LATE THIS AFTERNOON AND CONSEQUENTLY SPLIT
INTO TWO CIRCULATION CENTERS. AT THE PRESENT TIME ONE WAS POSITIONED
OVER SOUTHEAST WYOMING...THE OTHER OVER SOUTHEAST COLORADO. AT THE
SURFACE...A DEEP LOW FORMED OVER EL PASO AND SOUTHERN LINCOLN
COUNTIES LATE THIS AFTERNOON AND HAS SINCE SHIFTED NORTHEASTWARD TO
NEAR MCCOOK IN EXTREME SOUTHWEST NEBRASKA. EARLIER THIS EVENING A
BAND OF MODERATE SNOWFALL STRETCHING NORTHEAST ACROSS LINCOLN...
WASHINGTON AND PHILLIPS COUNTIES AS THE SFC LOW TRACKED NORTHEAST.
THIS LINE OF PCPN HAS SINCE SHIFTED EAST INTO KANSAS/SWRN NEBRASKA
WHERE IT IGNITED INTO A LINE OF THUNDERSTORMS EARLY THIS EVENING.
LATEST RUN OF THE RAP AND NAM MODELS SHOW THIS SFC LOW TRACKING VERY
SLOWLY NORTHWARD ACROSS SWRN NEBRASKA DURING THE NEXT SEVERAL HOURS.
THE RESULTING TIGHT PRESSURE GRADIENT AROUND THIS DEEPENING LOW IS
EXPECTED TO GENERATE STRONG NORTH-NORTHWEST SFC WINDS ACROSS THE
NORTHEAST COLORADO...BEGINNING NOT LONG AFTER MIDNIGHT. WITH LITTLE
OR NO SNOW ON THE GROUND YET...BLIZZARD CONDITIONS OBVIOUSLY HAVE
NOT DEVELOPED YET. HOWEVER...MODELS SHOW A RESURGENCE IN PCPN ACROSS
THE NERN CORNER OF THE STATE IN THE NEXT FEW HOURS AS THE UPPER LOW
IN SERN COLORADO ROTATES NORTHWARD. SO BLIZZARD CONDITIONS ARE STILL
EXPECTED TO DEVELOP. THEREFORE ZONES 48..49...50 AND 51 REMAIN UNDER
A BLIZZARD WARNING.
MEANWHILE THE UPPER LOW OVER SOUTHEAST WYOMING IS PROGGED TO ROTATES
SOUTHWESTWARD OVER NORTHWEST COLORADO DURING THE NEXT SEVERAL HOURS.
AS IT DOES...SHOULD SEE SNOWFALL ON THE INCREASE IN THE MOUNTAINS
AND HIGH VALLEYS OF NORTH CENTRAL COLORADO. NEW SNOW AMOUNTS BY
MIDDAY SUNDAY EXPECTED TO RANGE FROM 4-7 INCHES IN MTN AREAS ROUGHLY
NORTH OF I-70 AND 2-5 INCH TOTALS SOUTH OF THERE...WITH LIGHTER
AMOUNTS ON VALLEY FLOORS. SHOULD ALSO SEE GUSTY NORTHWEST WINDS OVER
THE HIGHER TERRAIN LATER TONIGHT AND SUNDAY MORNING CAUSING AREAS OF
BLOWING SNOW. THUS...THE WINTER WEATHER ADVISORY FOR SNOW AND
BLOWING WAS ALLOWED TO CONTINUE FOR MTN ZONES 31...33 AND 34. AS FOR
THE BLIZZARD WARNING IN NORTHEAST COLORADO...THOUGHT BEST TO DROP
ZONES 42 AND 44 FROM THE WARNING AS IT NOW APPEARS THESE ZONES WILL
SEE LITTLE SNOW ACCUMULATION. ALSO DROPPED THE WINTER WEATHER
ADVISORY FOR ZONES 45 AND 46 FOR THE SAME REASON.
.AVIATION...AT THIS HOUR (05Z) SNOWFALL WAS PRETTY MUCH OVER IN
THE DENVER METRO AREA. HOWEVER COULD SEE ANOTHER BATCH OF LIGHT
SNOW CURRENTLY UP ALONG THE WYOMING BORDER NORTH OF FORT COLLINS
SLIDING SOUTH ALONG THE FRONT RANGE IN THE NEXT FEW HOURS. NOT
EXPECTING MUCH IF ANY ACCUMULATION WITH THIS LAST WAVE OF SNOW.
HOWEVER LIFR AND IFR CEILINGS LIKELY TO REMAIN OVER THE DENVER
METRO AREA FOR MUCH OF THE NIGHT WITH THE LOWER CEILINGS
ACCOMPANYING THE LIGHT PRECIPITATION. NORTH-NORTHWEST SFC WINDS OF
07-14KTS ARE FORECAST TO STEADILY INCREASE REST OF THE TONIGHT
WITH SUSTAINED WINDS OF 12-22KT AND HIGHER GUSTS TO AROUND 30KTS
GENERALLY EAST OF I-25. THESE GUSTY NORTHERLY WINDS LIKELY TO
CONTINUE FOR MUCH OF SUNDAY AS CEILINGS CONTINUE TO RISE WITH
DRIER AIR SLIDING DOWN FROM WYOMING ON THE BACK SIDE OF THE
EXITING LOW PRESSURE SYSTEM. BY LATE IN THE DAY...THERE IS A
CHANCE OF SNOW AT BJC AND APA AIRPORTS WITH LOW LEVEL UPSLOPE
WINDS ALONG THE FRONT RANGE. DO NOT EXPECT TO SEE ANY SNOW AT DIA
DURING THE DAY.
&&
.PREV DISCUSSION... /ISSUED 303 PM MST SAT FEB 9 2013/
SHORT TERM...ONLY MINOR CHANGES THIS AFTERNOON. THE CIRCULATION
AT THE SOUTH END OF THE TROUGH REMAINS SLIGHTLY SOUTH OF WHERE IT
WAS EXPECTED TO BE...AND THE 18Z NAM COMES ALONG WITH A SIMILAR
SOUTHWARD ADJUSTMENT OF PERHAPS 40 MILES...ADDING CONFIDENCE TO
THE CHANGES MADE THIS MORNING. IT COMES UP WITH A MORE REASONABLE
INTENSITY TO ITS SNOWBAND WHICH SNOW STRETCHES ALONG THE PLAINS
FROM LIMON TO JULESBURG. WE WILL STICK WITH OUR PREVIOUS SNOW
FORECAST WHICH HAS THOSE DETAILS COMPROMISED BETWEEN SEVERAL MODEL
RUNS...BUT GENERALLY LIGHT FROM GREELEY AND DENVER WESTWARD WITH
ABOUT 4 INCHES THROUGH FORT MORGAN AND DIA AND THEN UP TO 8 INCHES
OUT IN THE NORTHEAST CORNER. STILL POTENTIAL FOR MORE SOMEWHERE
IF WE DO GET A CONCENTRATED SLOW MOVING BAND FOR A WHILE...BUT THE
4 TO 8 IN GENERAL SHOULD BE FINE. WIND ALSO JUST A LITTLE STRONGER
WITH THE LATEST MODEL RUNS. NUDGING THINGS SOUTHWARD GIVES HIGHER
CONFIDENCE TO ENOUGH SNOW/WIND FOR AN ADVISORY FOR THE STRETCH
FROM BENNETT TO LIMON. THE PART OF SOUTHERN WELD COUNTY EAST OF
HIGHWAY 85...AND WESTERN ELBERT/SOUTHERN DOUGLAS COUNTY COULD ALSO
HAVE A FAIR AMOUNT OF BLOWING SNOW...IF THERE IS ENOUGH SNOWFALL.
MEANWHILE THE AREA FROM DENVER NORTHWARD WILL HAVE TO GET ITS SNOW
IN THE NEXT 6 HOURS OR SO AS THE CONVECTIVE BLOB GOES BY...THEN
THE DOWNSLOPING SHOULD OVERRIDE THE WEAKER LIFT THAT WILL BE LEFT.
THE SNOW WILL LIKELY BE JUST ABOUT DONE ON SUNDAY MORNING THOUGH
THERE COULD STILL BE A LITTLE ALONG THE EASTERN BORDER. THE WIND
WILL BE EASING IN THE WEST...BUT COULD BE SLOW TO COME DOWN IN THE
EAST. EXPECT THAT CONDITIONS WILL BE IMPROVING IN THE NORTHEAST
CORNER IN THE AFTERNOON...BUT IF SNOWFALL IS TOWARD THE HIGHER END
OF OUR RANGE THEN VISIBILITIES COULD STILL BE PRETTY BAD.
LONG TERM...AN UPPER LEVEL TROUGH DROPPING SOUTH OUT OF THE
NORTHERN RCOKIES WILL BE CENTERED OVER THE GREAT BASIN SUNDAY NIGHT.
AS THIS TROUGH SINKS SOUTH...IT WILL SPREAD LIFT AND MOISTURE OVER
WESTERN AND CENTRAL COLORADO SUNDAY NIGHT AND MONDAY. FORCING AND
MOISTURE NOT GREAT...BUT ENOUGH TO PRODUCE LIGHT SNOW OVER THE
MOUNTAINS AND SOUTHERN FOOTHILLS. SOME UPSLOPE DEVELOPS WITH THIS
SYSTEM...SO THERE COULD BE A LITTLE LIGHT SNOW ALONG THE FRONT
RANGE. THE BEST CHANCE BEING ALONG THE PALMER DIVIDE. SNOW WILL COME
TO AN END MONDAY NIGHT AS THE TROUGH SHIFTS SOUTHEAST ACROSS THE
SOUTHERN ROCKIES.
A WEAK RIDGE EMBEDDED IN A NORTHWEST FLOW ALOFT WILL MOVE ACROSS
COLORADO TUESDAY NIGHT AND EARLY WEDNESDAY. THIS WILL BRING MILDER
TEMPERATURES AND DRY CONDITIONS. THIS WILL BE SHORT LIVED AS THE
NEXT SHORT WAVE TROUGH DROPS SOUTH OUT OF THE NORTHERN ROCKIES. THIS
SYSTEM WILL PUSH A COLD FRONT TROUGH COLORADO RESULTING IN COOLER
TEMPERATURES FOR THURSDAY AND FRIDAY. A LOT OF DIFFERENCES AMONG THE
MODELS. MOST OF THEM INDICATE MOISTURE WILL BE LIMITED WITH THIS
SYSTEM. FOR NOW...WILL KEEP THE MENTION OF SNOW CONFINED TO THE
HIGHER TERRAIN FOR WEDNESDAY NIGHT THROUGH FRIDAY. SATURDAY WILL BE
MILD AND DRY AS THIS TROUGH MOVES OFF TO THE EAST AND THE NEXT RIDGE
FORMS OVER THE REGION.
AVIATION...SNOW SHOWERS THROUGH MID EVENING...IT IS NOW LOOKING
LIKE THE STRONGER INTENSITIES MAY BE BEFORE 00Z RATHER THEN AFTER.
IN ANY EVENT THERE WILL BE PERIODS OF IFR CONDITIONS THROUGH 04Z
AND THEY MAY PREVAIL FOR SEVERAL HOURS. HEAVIER SHOWERS MAY
PRODUCE 1/2 MILE VISIBILITIES BUT ONLY FOR SHORT LENGTHS OF TIME.
AFTER 04Z CEILINGS AND VISIBILITIES WILL IMPROVE ALTHOUGH
INSTRUMENT APPROACHES MAY BE NEEDED TO KDEN THROUGH THE NIGHT. ON
SUNDAY NORTHWEST WINDS WILL CONTINUE WITH GUSTS IN THE 20 TO 30
KNOT RANGE...SOME UNCERTAINTY ABOUT HOW HIGH THE CEILINGS WILL BE
BUT PROBABLY HIGH ENOUGH FOR VISUAL APPROACHES TO KDEN.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING UNTIL 5 PM MST SUNDAY FOR COZ048>051.
WINTER WEATHER ADVISORY UNTIL 11 AM MST SUNDAY FOR COZ031-033-
034.
&&
$$
SHORT TERM...BAKER/GIMMESTAD
LONG TERM....MEIER
AVIATION...BAKER/GIMMESTAD
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1041 PM MST SAT FEB 9 2013
.UPDATE...
&&
.SHORT TERM...THE UPPER TROUGH OVER WESTERN COLORADO EARLIER
TODAY JUMPED THE DIVIDE LATE THIS AFTERNOON AND CONSEQUENTLY
SPLIT INTO TWO CIRCULATION CENTERED. AT THE PRESENT TIME ONE WAS
POSITIONED OVER SOUTHWEST WYOMING..THE OTHER OVER SOUTHEAST
COLORADO. AT THE SURFACE...A DEEP LOW FORMED OVER EL PASO AND
LINCOLN COUNTIES LATE THIS AFTERNOON AND HAS SINCE SHIFTS
NORTHEASTWARD TO MCCOOK IN EXTREME SOUTHWEST NEBRASKA. EARLIER
THIS EVENING SAW A BAND OF MODERATE SNOWFALL ON RADAR STRETCHED
ACROSS LINCOLN COUNTY UP ACROSS WASHINGTON AND PHILLIPS COUNTIES
IN THE VICINITY OF THIS SFC LOW. SINCE THEN...THIS LINE OF PCPN
HAS SHIFTED EAST INTO KANSAS/SWRN NEBRASKA WHERE IT IGNITED INTO A
LINE OF THUNDERSTORMS. LATE RUN OF THE RAP AND NAM MODELS SHOW
THIS SFC LOW TRACKING VERY SLOWLY NORTHWARD ACROSS SWRN NEBRASKA
NEXT SEVERAL HOURS. THE RESULTING TIGHT PRESSURE GRADIENT AROUND
THIS DEEPENING LOW IS EXPECTED TO GENERATE STRONG NORTH-NORTHWEST
SFC WINDS ACROSS THE NORTHEAST CORNER OF COLORADO...BEGINNING
SOMETIME AFTER MIDNIGHT. OF COURSE WITH LITTLE OR NO SNOW ON THE
GROUND OUT THERE YET...NOT LIKELY WE/LL SEE BLIZZARD CONDITIONS.
HOWEVER...MODELS SHOW A RESURGENCE IN PCPN ACROSS THE NERN CORNER
OF THE STATE IN THE NEXT FEW HOURS AS THE UPPER LOW IN SERN
COLORADO ROTATES NORTHWARD. MEANWHILE THE UPPER LOW OVER
SOUTHEAST WYOMING IS PROGGED TO ROTATES SOUTHWESTWARD OVER
NORTHWEST COLORADO DURING THE NEXT SEVERAL HOURS. AS IT DOES...
SHOULD SEE SNOWFALL ON THE INCREASE IN THE MOUNTAINS AND HIGH
VALLEYS OF NORTH CENTRAL COLORADO. NEW SNOW AMOUNTS BY MIDDAY
SUNDAY EXPECTED TO RANGE FROM 4-7 INCHES IN MTN AREAS ROUGHLY
NORTH OF I-70 AND 2-5 INCH TOTALS SOUTH OF THERE...WITH LIGHTER
AMOUNTS ON VALLEY FLOORS. SHOULD ALSO SEE GUSTY NORTHWEST WINDS
OVER THE HIGHER TERRAIN LATER TONIGHT AND SUNDAY MORNING CAUSING
AREAS OF BLOWING SNOW. THUS...THE WINTER WEATHER ADVISORY FOR
SNOW AND BLOWING WAS ALLOWED TO CONTINUE FOR MTN ZONES 31...33
AND 34. AS FOR THE BLIZZARD WARNING IN NORTHEAST COLORADO...
THOUGHT BEST TO DROP ZONES 42 AND 44 FROM THE WARNING AS IT NOW
APPEARS THESE ZONES WILL SEE LITTLE SNOW ACCUMULATION. ALSO
DROPPED THE WINTER WEATHER ADVISORY FOR ZONES 45 AND 46 FOR THE
SAME REASON.
.AVIATION...AT THIS HOUR (05Z) SNOWFALL WAS PRETTY MUCH OVER IN
THEDENVER METRO AREA. HOWEVER COULD SEE ANOTHER BATCH OF LIGHT
SNOW CURRENTLY UP ALONG THE WYOMING BORDER NORTH OF FORT COLLINS
SLIDING SOUTH ALONG THE FRONT RANGE IN THE NEXT FEW HOURS. NOT
EXPECTING MUCH IF ANY ACCUMULATION WITH THIS LAST WAVE OF SNOW.
HOWEVER LIFR AND IFR CEILINGS LIKELY TO REMAIN OVER THE DENVER
METRO AREA FOR MUCH OF THE NIGHT WITH THE LOWER CEILINGS
ACCOMPANYING THE LIGHT PRECIPITATION. NORTH-NORTHWEST SFC WINDS OF
07-14KTS ARE FORECAST TO STEADILY INCREASE REST OF THE TONIGHT
WITH SUSTAINED WINDS OF 12-22KT AND HIGHER GUSTS TO AROUND 30KTS
GENERALLY EAST OF I-25. THESE GUSTY NORTHERLY WINDS LIKELY TO
CONTINUE FOR MUCH OF SUNDAY AS CEILINGS CONTINUE TO RISE WITH
DRIER AIR SLIDING DOWN FROM WYOMING ON THE BACK SIDE OF THE
EXITING LOW PRESSURE SYSTEM. BY LATE IN THE DAY...THERE IS A
CHANCE OF SNOW AT BJC AND APA AIRPORTS WITH LOW LEVEL UPSLOPE
WINDS ALONG THE FRONT RANGE. DO NOT EXPECT TO SEE ANY SNOW AT DIA
DURING THE DAY.
&&
.PREV DISCUSSION... /ISSUED 303 PM MST SAT FEB 9 2013/
SHORT TERM...ONLY MINOR CHANGES THIS AFTERNOON. THE CIRCULATION
AT THE SOUTH END OF THE TROUGH REMAINS SLIGHTLY SOUTH OF WHERE IT
WAS EXPECTED TO BE...AND THE 18Z NAM COMES ALONG WITH A SIMILAR
SOUTHWARD ADJUSTMENT OF PERHAPS 40 MILES...ADDING CONFIDENCE TO
THE CHANGES MADE THIS MORNING. IT COMES UP WITH A MORE REASONABLE
INTENSITY TO ITS SNOWBAND WHICH SNOW STRETCHES ALONG THE PLAINS
FROM LIMON TO JULESBURG. WE WILL STICK WITH OUR PREVIOUS SNOW
FORECAST WHICH HAS THOSE DETAILS COMPROMISED BETWEEN SEVERAL MODEL
RUNS...BUT GENERALLY LIGHT FROM GREELEY AND DENVER WESTWARD WITH
ABOUT 4 INCHES THROUGH FORT MORGAN AND DIA AND THEN UP TO 8 INCHES
OUT IN THE NORTHEAST CORNER. STILL POTENTIAL FOR MORE SOMEWHERE
IF WE DO GET A CONCENTRATED SLOW MOVING BAND FOR A WHILE...BUT THE
4 TO 8 IN GENERAL SHOULD BE FINE. WIND ALSO JUST A LITTLE STRONGER
WITH THE LATEST MODEL RUNS. NUDGING THINGS SOUTHWARD GIVES HIGHER
CONFIDENCE TO ENOUGH SNOW/WIND FOR AN ADVISORY FOR THE STRETCH
FROM BENNETT TO LIMON. THE PART OF SOUTHERN WELD COUNTY EAST OF
HIGHWAY 85...AND WESTERN ELBERT/SOUTHERN DOUGLAS COUNTY COULD ALSO
HAVE A FAIR AMOUNT OF BLOWING SNOW...IF THERE IS ENOUGH SNOWFALL.
MEANWHILE THE AREA FROM DENVER NORTHWARD WILL HAVE TO GET ITS SNOW
IN THE NEXT 6 HOURS OR SO AS THE CONVECTIVE BLOB GOES BY...THEN
THE DOWNSLOPING SHOULD OVERRIDE THE WEAKER LIFT THAT WILL BE LEFT.
THE SNOW WILL LIKELY BE JUST ABOUT DONE ON SUNDAY MORNING THOUGH
THERE COULD STILL BE A LITTLE ALONG THE EASTERN BORDER. THE WIND
WILL BE EASING IN THE WEST...BUT COULD BE SLOW TO COME DOWN IN THE
EAST. EXPECT THAT CONDITIONS WILL BE IMPROVING IN THE NORTHEAST
CORNER IN THE AFTERNOON...BUT IF SNOWFALL IS TOWARD THE HIGHER END
OF OUR RANGE THEN VISIBILITIES COULD STILL BE PRETTY BAD.
LONG TERM...AN UPPER LEVEL TROUGH DROPPING SOUTH OUT OF THE
NORTHERN RCOKIES WILL BE CENTERED OVER THE GREAT BASIN SUNDAY NIGHT.
AS THIS TROUGH SINKS SOUTH...IT WILL SPREAD LIFT AND MOISTURE OVER
WESTERN AND CENTRAL COLORADO SUNDAY NIGHT AND MONDAY. FORCING AND
MOISTURE NOT GREAT...BUT ENOUGH TO PRODUCE LIGHT SNOW OVER THE
MOUNTAINS AND SOUTHERN FOOTHILLS. SOME UPSLOPE DEVELOPS WITH THIS
SYSTEM...SO THERE COULD BE A LITTLE LIGHT SNOW ALONG THE FRONT
RANGE. THE BEST CHANCE BEING ALONG THE PALMER DIVIDE. SNOW WILL COME
TO AN END MONDAY NIGHT AS THE TROUGH SHIFTS SOUTHEAST ACROSS THE
SOUTHERN ROCKIES.
A WEAK RIDGE EMBEDDED IN A NORTHWEST FLOW ALOFT WILL MOVE ACROSS
COLORADO TUESDAY NIGHT AND EARLY WEDNESDAY. THIS WILL BRING MILDER
TEMPERATURES AND DRY CONDITIONS. THIS WILL BE SHORT LIVED AS THE
NEXT SHORT WAVE TROUGH DROPS SOUTH OUT OF THE NORTHERN ROCKIES. THIS
SYSTEM WILL PUSH A COLD FRONT TROUGH COLORADO RESULTING IN COOLER
TEMPERATURES FOR THURSDAY AND FRIDAY. A LOT OF DIFFERENCES AMONG THE
MODELS. MOST OF THEM INDICATE MOISTURE WILL BE LIMITED WITH THIS
SYSTEM. FOR NOW...WILL KEEP THE MENTION OF SNOW CONFINED TO THE
HIGHER TERRAIN FOR WEDNESDAY NIGHT THROUGH FRIDAY. SATURDAY WILL BE
MILD AND DRY AS THIS TROUGH MOVES OFF TO THE EAST AND THE NEXT RIDGE
FORMS OVER THE REGION.
AVIATION...SNOW SHOWERS THROUGH MID EVENING...IT IS NOW LOOKING
LIKE THE STRONGER INTENSITIES MAY BE BEFORE 00Z RATHER THEN AFTER.
IN ANY EVENT THERE WILL BE PERIODS OF IFR CONDITIONS THROUGH 04Z
AND THEY MAY PREVAIL FOR SEVERAL HOURS. HEAVIER SHOWERS MAY
PRODUCE 1/2 MILE VISIBILITIES BUT ONLY FOR SHORT LENGTHS OF TIME.
AFTER 04Z CEILINGS AND VISIBILITIES WILL IMPROVE ALTHOUGH
INSTRUMENT APPROACHES MAY BE NEEDED TO KDEN THROUGH THE NIGHT. ON
SUNDAY NORTHWEST WINDS WILL CONTINUE WITH GUSTS IN THE 20 TO 30
KNOT RANGE...SOME UNCERTAINTY ABOUT HOW HIGH THE CEILINGS WILL BE
BUT PROBABLY HIGH ENOUGH FOR VISUAL APPROACHES TO KDEN.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING UNTIL 5 PM MST SUNDAY FOR COZ048>051.
WINTER WEATHER ADVISORY UNTIL 11 AM MST SUNDAY FOR COZ031-033-
034.
&&
$$
SHORT TERM...BAKER/GIMMESTAD
LONG TERM....MEIER
AVIATION...BAKER/GIMMESTAD
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
315 AM EST SUN FEB 10 2013
.DISCUSSION...
TODAY-TONIGHT...
HIGH PRES RIDGE SPANNING THE LENGTH OF THE ERN SEABOARD WILL
CONTINUE TO DOMINATE THE LCL WX PATTERN. THE RIDGE IS EMBEDDED
WITHIN A STRONG W TO SW H85-H30 FLOW THAT WILL PUSH IT INTO THE W
ATLC OVER THE NEXT 24HRS. THIS MOTION WILL FORCE SFC/LOW LVL ERLY
WINDS ACRS CENTRAL FL TO VEER TO THE SE THRU THE DAY...THEN TO THE
S/SE OVERNIGHT.
THE INCREASING SRLY WIND COMPONENT WILL ALLOW A GRADUAL WARMING
TREND TO BEGIN. AFTN MAX TEMPS IN THE M/U70S AREAWIDE...SLIGHTLY ABV
AVG FOR EARLY FEB. INCREASING SRLY FLOW OVERNIGHT WILL KEEP MIN
TEMPS IN THE U50S/L60S INTERIOR AND N OF THE CAPE...L/M60S SPACE AND
TREASURE COASTS...ARND 10F ABV AVG.
EVENING SOUNDINGS SHOW A STRONG SUBSIDENCE INVERSION THRU THE
H90-H70 LYR THAT WILL EFFECTIVELY CAP VERTICAL MOTION BLO 5KFT.
LATEST RAP ANALYSIS SHOWS A FAIR AMOUNT OF REMNANT FRONTAL MOISTURE
LINGERING OVER THE S HALF OF THE PENINSULA...H100-H85 LYR MEAN RH
VALUES BTWN 70-80PCT. RH VALUES DIMINISH UPSTREAM BUT STILL LARGELY
BTWN 50-60PCT. THIS SHOULD BE ENOUGH TO ALLOW A SCT-BKN STRATOCU
DECK TO FORM ACRS CENTRAL FL AFT SUNRISE THAT WILL PANCAKE AT THE
BASE OF THE AFOREMENTIONED RIDGE. OVERALL MOISTURE IS TOO LOW AND
THE INVERSION TOO STRONG TO ALLOW ANY SHRAS TO FORM.
MONDAY...LOW LVL SOUTHERLY FLOW IN THE MORNING WILL VEER TO S-SW IN
THE AFTERNOON AS A COLD FRONT MOVES TWD S GA AND THE FL PANHANDLE.
SHOULD BE PARTLY SUNNY WITH HIGHS IN THE UPPER 70S ALONG THE VOLUSIA
COAST TO LOWER 80S OVER THE INTERIOR.
MONDAY NIGHT...LIGHT SW FLOW AHEAD OF THE NEXT FRONT AND DEWPTS IN
THE 60S ALONG WITH MOSTLY CLEAR SKIES IN THE LATE EVENING WILL ALLOW
LATE NIGHT FOG TO DEVELOP. THE FOG SHOULD BE MORE PREVALENT ACROSS
NRN SECTIONS INCLUDING LAKE AND VOLUSIA COUNTIES.
TUESDAY-TUE NIGHT...LOW LVL SOUTHERLY FLOW WILL CONTINUE WITH
ANOTHER WARM AFTERNOON IN THE UPPER 70S NRN SECTIONS TO LOWER 80S
SOUTH. A MID LVL DISTURBANCE ACROSS OK WILL INDUCE A LOW PRESSURE
AREA TO DEVELOP ALONG THE FRONT ALONG THE NRN GULF COAST THAT WILL
TRACK ENE THROUGH TUE NIGHT. AT THIS TIME IT LOOKS LIKE THE
PREFRONTAL CONVECTIVE LINE WILL REMAIN ACROSS NRN FL THROUGH THE
LATE NIGHT HOURS AND WILL KEEP POPS LESS THAN 20 PERCENT ACROSS NRN
SECTIONS FOR NOW TUE NIGHT BASED ON 00Z MODELS. EXPECT INCREASING
CLOUDINESS ACROSS NRN SECTIONS LATE TUE NIGHT WITH LOW TEMPS MILD IN
THE 60S.
WED...00Z MODELS ARE IN AGREEMENT THAT THE PREFRONTAL CONVECTIVE
LINE WILL REACH NRN SECTIONS WED MORNING AND MOVE SE THROUGH E
CENTRAL FL THROUGH THE DAY AND OFF THE TREASURE COAST BY LATE
EVENING. CAPES IN THE 500-800 J/KG RANGE AND NEGATIVE LIS SHOULD
SUPPORT THUNDER CHANCES WITH THE LINE ACROSS CENTRAL AND NRN
SECTIONS. TRENDS SHOULD BE FOR WEAKENING THROUGH THE DAY AND WILL
ONLY CARRY SLGT SHOWER CHCS LATE IN THE DAY FOR FAR SRN SECTIONS.
HIGHS AHEAD OF THE FRONT WILL BE WARM IN THE LOWER 80S.
WED NIGHT...THE FRONT SHOULD PASS OFF TO THE SE THROUGH THE NIGHT
WITH SOME ISOLATED SHOWERS ENDING ACROSS THE TREASURE COAST BY LATE
EVENING. MODELS HINTING AT SOME OVERRUNNING DEVELOPING LATE AND FOR
NOW EXPECT CONSIDERABLE CLOUDINESS.
THU...OLD FRONTAL BOUNDARY SHOULD ACT AS A WARM FRONT ACROSS FAR S
FL WITH MID LVL OVERRUNNING EXPECT TO BRING AREAS OF LIGHT RAIN
ACROSS CENTRAL AND SOUTH FL. WILL KEEP POPS IN SCATTERED RANGE
THOUGH LATER FORECASTS MAY NEED TO INCREASE RAIN CHANCES WITH AREA
OF STRATIFORM RAIN LIKELY MOVING IN ACROSS THE CENTRAL PENINSULA BY
AFTERNOON.
FRIDAY-SUNDAY...MODELS INDICATE SECONDARY CYCLOGENESIS ACROSS THE
ATLC FRIDAY NE OF THE BAHAMAS WITH TRAILING FRONTAL MOISTURE ACROSS
THE SRN HALF OF THE PENINSULA. THROUGH THE WEEKEND...THE LONGWAVE
TROUGH WILL DEEPEN ACROSS THE ERN CONUS SHUNTING THE DEEP MOISTURE
SE AWAY FROM THE AREA BY FRIDAY NIGHT AND ALLOWING A COLDER
CONTINENTAL AIRMASS TO MOVE DOWN THE PENINSULA. LOOKS LIKE BELOW
NORMAL TEMPS FOR THE UPCOMING WEEKEND WITH HIGHS IN THE 60S AND LOWS
MAINLY IN THE 40S.
&&
.AVIATION...
THRU 11/00Z...VFR ALL SITES...BTWN 10/15Z-11/00Z E/SE SFC WND G22KTS.
&&
.MARINE...
TODAY-TONIGHT...HI PRES RIDGE APPROACHING THE ERN SEABOARD WILL
MAINTAIN A FAIRLY TIGHT PGRAD OVER THE FL PENINSULA...GEOSTROPHIC
APPROX CHART INDICATES SUSTAINED SFC/BNDRY LYR WNDS BTWN 15-20KTS.
EARLY MRNG OBS FROM THE DATA BUOYS/C-MAN STATIONS ARE JUST BLO
15KTS...SEAS ARND 4FT AREAWIDE INCREASING TO ARND 6FT AT BUOY010.
THE RIDGE AXIS WILL PUSH INTO THE W ATLC OVER THE NEXT 24HRS...
ALLOWING WINDS TO VEER TO THE SE THRU THE DAY...THEN TO THE S/SE
OVERNIGHT. AS THEY DO...THE HIGHER SEAS N OF THE BAHAMAS SHOULD
ADVECT INTO THE LCL ATLC...ALLOWING WAVE HEIGHTS TO BUILD TO 4-6FT
AREAWIDE. CAUTIONARY STATEMENTS WILL CONTINUE.
SOUTHERLY WINDS TO 15 KNOTS OFFSHORE MONDAY WITH SEAS 4-6 FT WILL
DECREASE TO 3-4 FT BY TUE AFTN. NEXT COLD FRONT WILL CROSS THE
WATERS WED INTO WED NIGHT...WITH SW WINDS NEAR 20 KNOTS OFFSHORE AND
SEAS REBUILDING TO 4-6 FT. WINDS DECREASE FROM THE NW ON THU WITH
SEAS AGAIN SUBSIDING UNTIL NEXT INCREASE FROM THE NORTH NEXT WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 72 62 79 62 / 0 10 10 10
MCO 78 58 82 62 / 10 10 10 10
MLB 75 64 80 65 / 10 10 0 10
VRB 76 63 80 62 / 10 10 0 10
LEE 77 59 81 62 / 0 10 10 10
SFB 77 59 81 63 / 0 10 10 10
ORL 78 59 82 62 / 0 10 10 10
FPR 75 63 80 62 / 10 10 0 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...VOLKMER
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1115 PM CST SAT FEB 9 2013
.DISCUSSION...
ISSUED 835 PM CST SAT FEB 9 2013
CLOUDS CONTINUE TO INCREASE FROM SOUTHWEST TO NORTHEAST THIS
EVENING AS OUR NEXT WEATHER SYSTEM...CURRENTLY OVER SOUTHWEST
KANSAS...BEGINS TO LIFT NORTHEAST INTO THE CENTRAL PLAINS.
PRESSURE GRADIENT BEGINNING TO TIGHTEN UP OVER THE AREA AS
THE STORM BEGINS TO DEEPEN TO OUR WEST. SURFACE DEW POINTS
IN THE MID TO UPPER 50S CONFINED TO CENTRAL TEXAS THIS EVENING
BUT SHOULD HAVE NO PROBLEM STREAMING NORTHEAST OVERNIGHT ON
THE STRENGTH OF A 40-50 KT LOW LEVEL JET.
THE INITIAL BAND OF RAIN HAS STREAKED NORTHEAST TO JUST WEST OF
ST. LOUIS AND SHOULD PUSH EAST OF THE MISSISSIPPI RIVER IN THE
NEXT FEW HOURS AFFECTING OUR SOUTH AND WEST BY MIDNIGHT...AND THEN
WILL CONTINUE TO SHIFT OVER THE REMAINDER OF THE FORECAST AREA
INTO SUNDAY MORNING. LOOKS AS IF WE REACHED...OR WILL SHORTLY
REACH OUR LOWS FOR THE NIGHT AS THE COMBINATION OF CLOUDS AND AN
INCREASING SOUTHEAST WIND SHOULD HELP KEEP THE TEMPERATURES STEADY
OR SLOWLY RISING OVERNIGHT. HAVE MADE SOME ADJUSTMENTS TO THE
TIMING OF THE RAIN ACRS THE WEST AND SOUTH FOR LATER THIS EVENING.
STILL THE POSSIBILITY FOR SOME ISOLD CONVECTION BUT THAT LOOKS TO
BE MORE PROBABLE FOR SUNDAY MORNING IN THE 12Z-18Z TIME FRAME.
SHOULD HAVE THE UPDATED ZONES OUT BY 900 PM.
&&
.AVIATION...
ISSUED 1105 PM CST SAT FEB 9 2013
FORECAST CONCERNS CONTINUE TO REVOLVE AROUND TIMING OF MVFR/IFR
CIGS BACK INTO THE FORECAST AREA EITHER LATE TONIGHT OR JUST
AFTER DAWN SUNDAY. ONE BAND OF RAIN WAS TRACKING NORTHEAST OVER
PARTS OF WEST CENTRAL IL LATE THIS EVENING AND THAT WILL AFFECT
MOST OF OUR AREA. HAD A REPORT OF SOME SLEET MIXED IN WITH THE
RAIN DOWN IN STL BUT HAVE NOT SEEN ANY ADDITIONAL REPORTS OF
SLEET SINCE THEN. FORECAST SOUNDINGS SHOWING A VERY NARROW WINDOW
TIME FRAME WHERE SLEET MAY OCCUR BUT SIGNIFICANT WARM ADVECTION
OCCURRING AHEAD OF THE STORM SYSTEM TO OUR WEST SHOULD OVERCOME
ANY EVAPORATIVE COOLING THAT MAY OCCUR SO WILL CONTINUE TO GO
WITH -RA/-SHRA.
THE UPPER WAVE THAT IS CAUSING THIS INITIAL BAND OF PRECIP TO PUSH
ACRS THE AREA WILL SHIFT EAST OF OUR AREA AFTR 08Z...WITH A SECONDARY
SHORTWAVE SEEN PUSHING OUT OF THE SOUTHERN PLAINS WITH CONVECTION
DEVELOPING NOW OVER OKLAHOMA NE INTO SRN KANSAS. THIS BAND SHOULD
MOVE THRU THE TAF SITES IN THE 12Z-18Z TIME FRAME. MAY BE ENOUGH
ELEVATED INSTABILITY TO PRODUCE SOME ISOLD CONVECTION DURING THE
MORNING BUT COVERAGE LOOKS TOO LIMITED TO INCLUDE IN TAFS. FINALLY
THE COLD FRONT WILL SHIFT ACRS THE AREA IN THE 21Z-00Z TIME FRAME.
THERE APPEARS TO BE ENOUGH LOW LEVEL CONVERGENCE ALONG THE BOUNDARY
TO KEEP AT LEAST A VCSH MENTION IN ALL THE TAF SITES UNTIL THE
BOUNDARY SHIFTS EAST OF KCMI AROUND 02Z. AFTER THAT...THE BIG
CONCERN WILL BE WITH WRAP AROUND CLOUDS AND STRONG GRADIENT WINDS
AS THE STORM SYSTEM MOVES OFF TO OUR NORTH.
WILL SLOW DOWN THE INITIAL ONSET OF MVFR CIGS FOR A FEW HOURS ACRS
THE WEST AS UPSTREAM OBS NOT SHOWING MUCH IN THE WAY OF LOWER CIGS
UNTIL YOU GET OUT ACRS WEST CENTRAL AND SOUTHWEST MISSOURI. MODELS
CONTINUE TO SHOW THE DRY SLOW PUSHING IN EARLY IN THE AFTN WHICH
WILL CUT OFF THE STEADY RAINS AND MAY ACTUALLY BRING CIGS UP TO
VFR BY EVENING ACRS THE SOUTHWEST BEFORE THE WRAP AROUND MOISTURE
APPROACHES THE FORECAST AREA LATE TOMORROW EVENING AND OVERNIGHT
ALONG WITH THE STRONG SW WINDS. OUR SE WINDS TONIGHT WILL AVERAGE
FROM 12 TO 17 KTS WITH A FEW GUSTS ARND 22KTS...THEN WINDS WILL
VEER MORE INTO A SOUTHERLY DIRECTION ON SUNDAY AT 15 TO 20 KTS WITH
SOME GUSTS APPRCHG 30 KTS AT TIMES. JUST AFTR FROPA LATE TOMORROW
AFTN AND EVE...WINDS WILL SHIFT INTO THE SSW (200-230 DEGREES) AT
15 TO 25 KTS WITH GUSTS AOA 30 KTS.
SMITH
&&
.PREV DISCUSSION...
ISSUED 210 PM CST SAT FEB 9 2013
PESKY LOW CLOUDS WHICH HAVE PLAGUED THE AREA RECENTLY FINALLY
HAVE BEEN SIGNIFICANTLY ERODING OVER THE LAST SEVERAL HOURS. EARLY
AFTERNOON SATELLITE IMAGERY SHOWING THEM MAINLY CONFINED TO AREAS
FROM THE ILLINOIS RIVER EAST TO CHAMPAIGN...ALTHOUGH THE REST OF
THESE CLOUDS SHOULD BE GONE BY LATE AFTERNOON. NOT MUCH BREAK IN
THE CLOUDS EXPECTED...AS MID AND HIGH CLOUDS WERE RAPIDLY
ADVANCING IN FROM THE SOUTHWEST. LARGE UPPER LOW SLOWLY ADVANCING
THROUGH THE 4 CORNERS REGION AND STILL ON TARGET TO AFFECT OUR
WEATHER LATE TONIGHT INTO EARLY NEXT WEEK.
SHORT TERM...TONIGHT THROUGH MONDAY...
MORNING MODELS REMAIN IN GOOD AGREEMENT WITH LIFTING THE UPPER LOW
INTO THE UPPER MISSISSIPPI VALLEY BY SUNDAY EVENING. SHOWERS ON
THE INCREASE ACROSS OKLAHOMA THIS AFTERNOON AND WILL BE ADVECTING
NORTHEAST TONIGHT AHEAD OF INTENSIFYING CYCLONE OVER THE PLAINS. A
LOT OF DRY AIR IN THE LOWER LEVELS NEEDS TO BE OVERCOME IN OUR
AREA...BUT RAP MODEL SOUNDINGS SHOW THE COLUMN MOISTENED UP IN
SPRINGFIELD BY 2 AM AND THE NORTHEASTERN CWA AROUND 4-5 AM. HAVE
INTRODUCED SOME SLIGHT CHANCE POPS IN THE FAR SOUTHWEST LATE THIS
EVENING...BUT HIGHER OVERNIGHT POPS REMAIN AFTER MIDNIGHT. HIGHEST
POPS DURING THE PERIOD WILL BE ON SUNDAY MORNING...WITH A RAPID
ENDING OF THE RAIN FROM WEST TO EAST DURING THE AFTERNOON. WILL
LINGER SOME SLIGHT CHANCE POPS INTO THE EVENING EAST OF I-57.
WINDS ARE ALSO A CONCERN DURING THE PERIOD. PRESSURE GRADIENT
TIGHTENS OVERNIGHT AS THE SURFACE LOW LIFTS NORTHEAST TO AROUND
OMAHA BY LATE SUNDAY MORNING. WILL LIKELY SEE SOME GUSTS OF AROUND
30-35 MPH LATE MORNING THROUGH MID AFTERNOON. WINDS WILL REMAIN
FAIRLY BREEZY AS THEY SWING AROUND TOWARD THE SOUTHWEST OR WEST
SUNDAY NIGHT...THEN GUSTS OF 30-40 MPH LIKELY AGAIN ON MONDAY.
HIGHEST GUSTS SHOULD BE ALONG AND NORTH OF THE I-74 CORRIDOR...
CLOSER TO THE SURFACE LOW.
LONG TERM...TUESDAY THROUGH SATURDAY...
SOUTHERN BRANCH OF THE JET STREAM STILL LOOKS TO BE THE ACTIVE ONE
MOST OF THIS WEEK...AS ANOTHER LOW IS DUG OUT OF THE DEEP TROUGH
IN THE SOUTHWEST U.S. AND MOVES EASTWARD TOWARD THE GULF COAST.
LONGER RANGE MODELS KEEP ANY OVERRUNNING PRECIP JUST TO OUR SOUTH
LATE TUESDAY NIGHT AND WEDNESDAY AS THE SURFACE LOW LIFTS TOWARD
THE MID-ATLANTIC COAST. MAIN FEATURE OF CONCERN IN THE EXTENDED IS
THE CARVING OUT OF A DEEP TROUGH OVER THE CENTER OF THE NATION
LATE THIS WEEK...MARKING A PERIOD OF COLDER WEATHER WHICH WILL
BEGIN FRIDAY AND LAST MUCH OF THE WEEKEND. THE GFS AND ECMWF
MODELS BOTH FORM A SURFACE REFLECTION IN THE TROUGH...BUT THE GFS
IS A LOT STRONGER AND FURTHER NORTH WITH ANY PRECIPITATION. SLIGHT
CHANCE POPS ARE STILL WARRANTED LATE IN THE WEEK DUE TO THE
UNCERTAINTY.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
235 AM CST SUN FEB 10 2013
...UPDATED LONG TERM SECTION...
.SYNOPSIS...
ISSUED AT 1126 PM CST SAT FEB 9 2013
AT 00Z SUNDAY A -31C 500MB LOW WAS LOCATED OVER WESTERN COLORADO,
AND A +110KT 300MB JET STREAK EXTENDED FROM SOUTHWEST NEW MEXICO
INTO THE PANHANDLE OF OKLAHOMA. A SURFACE AND 850MB LOW WAS
LOCATED ACROSS EAST CENTRAL COLORADO AND WEST CENTRAL KANSAS. A
DRYLINE EXTENDED SOUTH OF THIS LOW ACROSS EXTREME WESTERN KANSAS. A
COLD FRONT STRETCHED FROM SOUTHWEST NEBRASKA, ACROSS NORTHWEST
KANSAS, INTO EAST CENTRAL COLORADO. LOW LEVEL MOISTURE WAS
PRESENT AHEAD OF THIS DRYLINE ACROSS WESTERN KANSAS WITH DODGE
CITY 00Z SOUNDING INDICATING A SATURATED LAYER UP TO AROUND THE
800MB LEVEL. WIDESPREAD STATUS AND FOG WAS ALSO REPORTED EARLIER
THIS MORNING. HAVILAND PROFILER AND 850MB WINDS AT 00Z INDICATED
40 TO 50KTS WERE PRESENT IN THE 850MB TO 800MB LEVEL.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 123 AM CST SUN FEB 10 2013
AN AREA OF LOW PRESSURE AT THE SURFACE LOCATED NEAR THE
KANSAS/COLORADO BORDER EARLIER THIS MORNING WILL LIFT NORTHEAST
ACROSS SOUTHERN NEBRASKA EARLY TODAY AS AN UPPER LEVEL TROUGH/LOW
CROSSES THE CENTRAL PLAINS. A TIGHT SURFACE PRESSURE GRADIENT WILL
EXIST ACROSS WESTERN AND NORTH CENTRAL KANSAS WITH 850MB WIND
SPEEDS OF AROUND 50KTS FORECAST TO BE LOCATED IN NORTH CENTRAL
KANSAS AT AROUND 18Z. THE TIGHT SURFACE PRESSURE GRADIENT ALONG
WITH 40-50KT WINDS JUST ABOVE THE SURFACE CONTINUES TO SUPPORT
WIND SPEEDS IN THE 30 TO 35 MPH RANGE ACROSS NORTH CENTRAL AND
MOST OF WESTERN KANSAS TODAY. THE POSSIBLE EXCEPTION WILL BE IN
EXTREME SOUTHWEST KANSAS NEAR ELKHART, BUT EVEN HERE WIND SPEEDS
NEAR 30 MPH ARE STILL POSSIBLE. SOME LOW TO MID LEVEL MOISTURE
LOCATED BEHIND A COLD FRONT WILL CROSS WESTERN KANSAS EARLY THIS
MORNING, AND GIVEN 850MB TO 500MB LAPSE RATES IN EXCESS OF 8C/KM
UNDER THE COLD UPPER LOW THERE MAY ALSO BE A FEW SPRINKLES OR A
BRIEF SHOWER WILL POSSIBLE AROUND DAYBREAK ALONG THE INTERSTATE 70
CORRIDOR.
TEMPERATURES TODAY WILL BE A LITTLE TRICKY ACROSS WEST CENTRAL
AND NORTH CENTRAL KANSAS GIVEN THE CLOUD COVER EXPECTED. STILL
UNSURE JUST HOW LONG THE CLOUDS WILL LINGER. GIVEN THIS ALONG WITH
THE NAM AND GFS MODEL SOUNDINGS HAVE DECIDED TO STAY CLOSE TO THE
COOLER MET GUIDANCE. FURTHER SOUTH, CLOSER TO THE OKLAHOMA
BORDER, THE 00Z SUNDAY 850MB MIX DOWN TEMPERATURES FROM THE ECMWF
AND GFS SUGGESTED HIGHS ONLY AROUND 50 DEGREES. HOWEVER GIVEN THE
AMOUNT OF SUNSHINE EXPECTED AND THE MIXING DEPTH EXPECTED WITH THE
NORTHWEST WINDS WILL STAY CLOSE TO THE WARMER PREVIOUS FORECAST.
TONIGHT UNDER PARTLY TO MOSTLY CLEAR SKIES THE GUSTY NORTHWEST
WINDS WILL SUBSIDE TO AROUND 10 MPH. LOWS FALLING BACK INTO THE
20S STILL APPEARS REASONABLE WITH SOME TEENS POSSIBLE IN NORTH
CENTRAL AND WEST CENTRAL KANSAS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 235 AM CST SUN FEB 10 2013
A MID TO UPPER LEVEL SHORTWAVE IS EXPECTED TO MOVE DOWN ACROSS THE
ROCKIES MONDAY THEN INTO THE CENTRAL AND SOUTHERN PLAINS MONDAY
NIGHT INTO TUESDAY. CLOUDS INCREASE IN COVERAGE AS THIS SYSTEM
APPROACHES WITH MOSTLY CLOUDY SKIES ANTICIPATED BY MONDAY NIGHT. A
CHANCE OF SNOW WILL BE POSSIBLE ACROSS FAR SOUTHWEST KANSAS AND THE
KS/OK BORDER MONDAY NIGHT INTO EARLY TUESDAY MORNING WITH A SLIGHT
CHANCE FARTHER NORTH. ACCUMULATIONS ARE EXPECTED TO BE LIGHT WITH
THE EXCEPTION OF AREAS ALONG THE KS/OK BORDER WHERE AN INCH OR TWO
MAY BE POSSIBLE. CLOUDS DECREASE IN COVERAGE ON TUESDAY MORNING
WITH MOSTLY CLEAR SKIES EXPECTED BY TUESDAY AFTERNOON. WINDS SHIFT
TO MORE OF A NORTHERLY DIRECTION MONDAY THEN BECOME LIGHT AND
VARIABLE MONDAY NIGHT INTO TUESDAY. A COLD DAY IS ANTICIPATED MONDAY
WITH HIGHS RANGING FROM THE UPPER 30S ACROSS THE KS/CO BORDER TO MID
40S ACROSS SOUTH CENTRAL KANSAS. THE COLDEST TEMPERATURES OF THE
FORECAST PERIOD ARE EXPECTED EARLY TUESDAY MORNING WITH LOWS RANGING
FROM THE MID TEENS ACROSS THE KS/CO BORDER TO MID 20S ACROSS SOUTH
CENTRAL KANSAS. HIGHS THEN REBOUND INTO THE 40S ON TUESDAY.
TRANQUIL WEATHER IS ANTICIPATED TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT AS HIGH PRESSURE DOMINATES THE REGION. MOSTLY CLEAR SKIES AND
DRY CONDITIONS ARE FORECASTED DURING THIS PERIOD WITH LIGHT
NORTHWEST WINDS. LOWS WEDNESDAY MORNING WILL GENERALLY BE IN THE 20S
WITH HIGHS WEDNESDAY IN THE LOWER 50S. LOWS THURSDAY MORNING ARE
FORECASTED TO FALL INTO THE UPPER 20S AND LOWER 30S.
MODELS THEN CONTINUE TO SUGGEST A MID TO UPPER LEVEL SHORTWAVE TO
MOVE DOWN FROM CANADA AND INTO THE PLAINS THURSDAY INTO FRIDAY. IF
THIS VERIFIES THIS WILL HELP PUSH A STRONG ARCTIC HIGH AND COLD
FRONT DOWN THROUGH THE ROCKIES AND PLAINS. AS OF NOW, TIMING OF THIS
FRONT LOOKS TO BE DURING THURSDAY AFTERNOON. INCREASED CLOUD
COVER IS EXPECTED THURSDAY NIGHT INTO FRIDAY AS THIS SYSTEM MOVES
THROUGH WESTERN KANSAS. THE 00Z GFS AND ECMWF HINT AT THE CHANCE OF
FLURRIES OR LIGHT SNOW THURSDAY NIGHT INTO FRIDAY AND HAVE PLACED A
SLIGHT CHANCE IN THE GRIDS TO REFLECT THIS. HIGHS THURSDAY ARE
FORECASTED TO RANGE FROM THE LOWER 40S ACROSS WEST CENTRAL KANSAS TO
AROUND 50 DEGREES ACROSS SOUTH CENTRAL KANSAS. LOWS THURSDAY NIGHT
WILL ONCE AGAIN DIP INTO THE 20S. COLD TEMPERATURES ARE FORECASTED
BEHIND THIS SYSTEM FRIDAY WITH HIGHS RANGING FROM THE MID 30S ACROSS
WEST CENTRAL KANSAS TO LOWER 40S ACROSS THE KS/OK BORDER.
UPPER LEVEL RIDGING BUILDS ACROSS THE PLAINS THIS WEEKEND WITH HIGH
PRESSURE BEING THE DOMINATING FEATURE AT THE SURFACE. THIS WILL
BRING PARTLY CLOUDY SKIES AND DRY CONDITIONS TO WESTERN KANSAS. LOWS
SATURDAY MORNING ARE FORECASTED TO BE IN THE LOWER 20S WITH HIGHS
SATURDAY AFTERNOON REBOUNDING INTO THE 40S. LOWS SUNDAY MORNING LOOK
TO DIP INTO THE MID TO UPPER 20S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1126 PM CST SAT FEB 9 2013
AREAS OF FOG AND IFR/LIFR CIGS WILL QUICKLY GIVE WAY TO VFR
CONDITIONS AS A DRYLINE MOVES EAST ACROSS WESTERN KANSAS EARLY
THIS MORNING. NAM AND HRRR BOTH SUGGEST VFR CONDITIONS AT GCK AT 06Z, AT
DDC AROUND 07Z, AND A BRIEF PERIOD VFR CONDITIONS AT HYS BETWEEN
8Z AND 11Z. LOW LEVEL MOISTURE POOLING BEHIND A COLD FRONT SURGING
SOUTHEAST ACROSS WESTERN KANSAS BEHIND THIS DRYLINE IS EXPECTED TO
PRODUCE SOME MVFR CIGS AT HYS AND GCK BETWEEN 11Z AND 15Z WITH
LOW VFR CIGS THEN BEING POSSIBLE AT HYS UNTIL 21Z. A TIGHT
PRESSURE GRADIENT WILL PERSIST ACROSS WESTERN KANSAS BEHIND THE
COLD FRONT. SUSTAINED NORTHWEST WINDS AT ALL THREE TAF SITES ARE
EXPECTED TO RANGE FROM 25 TO 30KTS. THE STRONGER WIND SPEEDS ARE
EXPECTED TO BE BETWEEN 17Z AND 22Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 21 42 22 / 0 0 10 30
GCK 43 19 39 19 / 0 0 10 20
EHA 49 20 38 20 / 0 10 10 30
LBL 48 21 41 21 / 0 10 10 30
HYS 42 21 41 19 / 10 0 10 10
P28 52 25 45 27 / 0 0 10 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 9 AM CST /8 AM MST/ THIS MORNING TO 6 PM CST
/5 PM MST/ THIS EVENING FOR KSZ030-031-043>046-061>066-074>081-
084>090.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
126 AM CST SUN FEB 10 2013
...UPDATED SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1126 PM CST SAT FEB 9 2013
AT 00Z SUNDAY A -31C 500MB LOW WAS LOCATED OVER WESTERN COLORADO,
AND A +110KT 300MB JET STREAK EXTENDED FROM SOUTHWEST NEW MEXICO
INTO THE PANHANDLE OF OKLAHOMA. A SURFACE AND 850MB LOW WAS
LOCATED ACROSS EAST CENTRAL COLORADO AND WEST CENTRAL KANSAS. A
DRYLINE EXTENDED SOUTH OF THIS LOW ACROSS EXTREME WESTERN KANSAS. A
COLD FRONT STRETCHED FROM SOUTHWEST NEBRASKA, ACROSS NORTHWEST
KANSAS, INTO EAST CENTRAL COLORADO. LOW LEVEL MOISTURE WAS
PRESENT AHEAD OF THIS DRYLINE ACROSS WESTERN KANSAS WITH DODGE
CITY 00Z SOUNDING INDICATING A SATURATED LAYER UP TO AROUND THE
800MB LEVEL. WIDESPREAD STATUS AND FOG WAS ALSO REPORTED EARLIER
THIS MORNING. HAVILAND PROFILER AND 850MB WINDS AT 00Z INDICATED
40 TO 50KTS WERE PRESENT IN THE 850MB TO 800MB LEVEL.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 123 AM CST SUN FEB 10 2013
AN AREA OF LOW PRESSURE AT THE SURFACE LOCATED NEAR THE
KANSAS/COLORADO BORDER EARLIER THIS MORNING WILL LIFT NORTHEAST
ACROSS SOUTHERN NEBRASKA EARLY TODAY AS AN UPPER LEVEL TROUGH/LOW
CROSSES THE CENTRAL PLAINS. A TIGHT SURFACE PRESSURE GRADIENT WILL
EXIST ACROSS WESTERN AND NORTH CENTRAL KANSAS WITH 850MB WIND
SPEEDS OF AROUND 50KTS FORECAST TO BE LOCATED IN NORTH CENTRAL
KANSAS AT AROUND 18Z. THE TIGHT SURFACE PRESSURE GRADIENT ALONG
WITH 40-50KT WINDS JUST ABOVE THE SURFACE CONTINUES TO SUPPORT
WIND SPEEDS IN THE 30 TO 35 MPH RANGE ACROSS NORTH CENTRAL AND
MOST OF WESTERN KANSAS TODAY. THE POSSIBLE EXCEPTION WILL BE IN
EXTREME SOUTHWEST KANSAS NEAR ELKHART, BUT EVEN HERE WIND SPEEDS
NEAR 30 MPH ARE STILL POSSIBLE. SOME LOW TO MID LEVEL MOISTURE
LOCATED BEHIND A COLD FRONT WILL CROSS WESTERN KANSAS EARLY THIS
MORNING, AND GIVEN 850MB TO 500MB LAPSE RATES IN EXCESS OF 8C/KM
UNDER THE COLD UPPER LOW THERE MAY ALSO BE A FEW SPRINKLES OR A
BRIEF SHOWER WILL POSSIBLE AROUND DAYBREAK ALONG THE INTERSTATE 70
CORRIDOR.
TEMPERATURES TODAY WILL BE A LITTLE TRICKY ACROSS WEST CENTRAL
AND NORTH CENTRAL KANSAS GIVEN THE CLOUD COVER EXPECTED. STILL
UNSURE JUST HOW LONG THE CLOUDS WILL LINGER. GIVEN THIS ALONG WITH
THE NAM AND GFS MODEL SOUNDINGS HAVE DECIDED TO STAY CLOSE TO THE
COOLER MET GUIDANCE. FURTHER SOUTH, CLOSER TO THE OKLAHOMA
BORDER, THE 00Z SUNDAY 850MB MIX DOWN TEMPERATURES FROM THE ECMWF
AND GFS SUGGESTED HIGHS ONLY AROUND 50 DEGREES. HOWEVER GIVEN THE
AMOUNT OF SUNSHINE EXPECTED AND THE MIXING DEPTH EXPECTED WITH THE
NORTHWEST WINDS WILL STAY CLOSE TO THE WARMER PREVIOUS FORECAST.
TONIGHT UNDER PARTLY TO MOSTLY CLEAR SKIES THE GUSTY NORTHWEST
WINDS WILL SUBSIDE TO AROUND 10 MPH. LOWS FALLING BACK INTO THE
20S STILL APPEARS REASONABLE WITH SOME TEENS POSSIBLE IN NORTH
CENTRAL AND WEST CENTRAL KANSAS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 337 PM CST SAT FEB 9 2013
ANOTHER UPPER LEVEL TROUGH WILL DIG INTO THE SOUTHERN ROCKIES BY
MONDAY AFTERNOON AS COOL HIGH PRESSURE SETTLES INTO THE NORTHERN AND
CENTRAL PLAINS. SURFACE LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS
WEST TEXAS BY 00Z TUESDAY IN RESPONSE TO THE DIGGING SYSTEM. THE VARIOUS
MODELS HANDLE THE SYSTEM DIFFERENTLY BY MONDAY NIGHT AND TUESDAY, BUT
THE GFS/GEM AND ECMWF ARE IN REASONABLE AGREEMENT IN PLACING THE
500MB LOW CENTER AROUND WICHITA FALLS, TX BY 00Z WEDNESDAY.
THE GEM IS MORE CLOSED OFF THAN THE ECMWF AND THEREFORE HAS HIGHER
SNOW AMOUNTS ACROSS FAR SOUTHWEST KANSAS. THE SYSTEM WILL BE WEAKENING
BY TUESDAY EVENING AND OPENING UP SO THAT THE BEST CHANCE FOR SNOW
ACCUMULATIONS (PERHAPS 1 TO 2 INCHES) SHOULD BE FURTHER WEST
INCLUDING ELKHART, LIBERAL AND ULYSSES, WITH LESSER AMOUNTS TO THE
EAST AT MEDICINE LODGE. IT APPEARS THAT THE SNOW WILL OCCUR LATE
MONDAY NIGHT AND TUESDAY MORNING, WITH SOME CLEARING BY TUESDAY
AFTERNOON.
SOME WARMING CAN BE EXPECTED BY WEDNESDAY AHEAD OF THE NEXT
SHORTWAVE TROUGH. HIGHS SHOULD REACH INTO THE UPPER 40S TO LOWER 50S.
THIS SYSTEM IS ADVERTISED TO DIG INTO THE SOUTHERN ROCKIES PER
ECMWF, BUT THE OTHER MODELS ARE FURTHER EAST WITH THE TROUGH.
NONE OF THE MODELS ARE FAVORABLE FOR PRECIPITATION. A COLD SURGE WILL
PROGRESS DOWN THE PLAINS AHEAD OF THE SYSTEM THURSDAY NIGHT, BUT
NOT BEFORE TEMPERATURES REACH INTO THE UPPER 40S TO LOWER 50S ON
THURSDAY. COOLER HIGHS IN THE MID OR UPPER 30S CAN BE EXPECTED BY
FRIDAY. SINCE SURFACE HIGH PRESSURE WILL BE FIRMLY IN PLACE AHEAD
OF THE SYSTEM, LITTLE IN THE WAY OF LOW LEVEL THERMAL ADVECTIONS ARE
EXPECTED SO THAT SNOW IS UNLIKELY THIS FAR NORTH AND EAST.
TRANQUIL WEATHER CAN BE EXPECTED FOR FRIDAY AND INTO NEXT WEEKEND AS
A NORTHWESTERLY FLOW PATTERN DEVELOPS ACROSS THE WESTERN UNITED STATES.
LOW LEVEL MOISTURE FROM THE GULF WILL LIKELY STAY WELL TO THE SOUTHEAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1126 PM CST SAT FEB 9 2013
AREAS OF FOG AND IFR/LIFR CIGS WILL QUICKLY GIVE WAY TO VFR
CONDITIONS AS A DRYLINE MOVES EAST ACROSS WESTERN KANSAS EARLY
THIS MORNING. NAM AND HRRR BOTH SUGGEST VFR CONDITIONS AT GCK AT 06Z, AT
DDC AROUND 07Z, AND A BRIEF PERIOD VFR CONDITIONS AT HYS BETWEEN
8Z AND 11Z. LOW LEVEL MOISTURE POOLING BEHIND A COLD FRONT SURGING
SOUTHEAST ACROSS WESTERN KANSAS BEHIND THIS DRYLINE IS EXPECTED TO
PRODUCE SOME MVFR CIGS AT HYS AND GCK BETWEEN 11Z AND 15Z WITH
LOW VFR CIGS THEN BEING POSSIBLE AT HYS UNTIL 21Z. A TIGHT
PRESSURE GRADIENT WILL PERSIST ACROSS WESTERN KANSAS BEHIND THE
COLD FRONT. SUSTAINED NORTHWEST WINDS AT ALL THREE TAF SITES ARE
EXPECTED TO RANGE FROM 25 TO 30KTS. THE STRONGER WIND SPEEDS ARE
EXPECTED TO BE BETWEEN 17Z AND 22Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 21 42 22 / 0 0 0 30
GCK 45 19 39 19 / 0 0 0 30
EHA 46 20 38 20 / 0 10 10 40
LBL 48 21 41 21 / 0 10 10 40
HYS 44 21 41 19 / 0 0 0 10
P28 52 25 45 27 / 0 0 0 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 9 AM CST /8 AM MST/ THIS MORNING TO 6 PM CST
/5 PM MST/ THIS EVENING FOR KSZ030-031-043>046-061>066-074>081-
084>090.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1133 PM CST SAT FEB 9 2013
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1126 PM CST SAT FEB 9 2013
AT 00Z SUNDAY A -31C 500MB LOW WAS LOCATED OVER WESTERN COLORADO,
AND A +110KT 300MB JET STREAK EXTENDED FROM SOUTHWEST NEW MEXICO
INTO THE PANHANDLE OF OKLAHOMA. A SURFACE AND 850MB LOW WAS
LOCATED ACROSS EAST CENTRAL COLORADO AND WEST CENTRAL KANSAS. A
DRYLINE EXTENDED SOUTH OF THIS LOW ACROSS EXTREME WESTERN KANSAS. A
COLD FRONT STRETCHED FROM SOUTHWEST NEBRASKA, ACROSS NORTHWEST
KANSAS, INTO EAST CENTRAL COLORADO. LOW LEVEL MOISTURE WAS
PRESENT AHEAD OF THIS DRYLINE ACROSS WESTERN KANSAS WITH DODGE
CITY 00Z SOUNDING INDICATING A SATURATED LAYER UP TO AROUND THE
800MB LEVEL. WIDESPREAD STATUS AND FOG WAS ALSO REPORTED EARLIER
THIS MORNING. HAVILAND PROFILER AND 850MB WINDS AT 00Z INDICATED
40 TO 50KTS WERE PRESENT IN THE 850MB TO 800MB LEVEL.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 220 PM CST SAT FEB 9 2013
A STRONG UPPER LOW AND SHORTWAVE TROUGH WILL MOVE FROM SOUTHEAST
COLORADO AND NEW MEXICO AND LIFT NORTHEASTWARD AND DEEPEN AS IT
MOVES INTO CENTRAL NEBRASKA AND KANSAS OVERNIGHT. A SURFACE DRYLINE
TROUGH WILL ADVANCE RAPIDLY EASTWARD FROM EASTERN COLORADO AND
ACROSS WESTERN KANSAS WITH A FEW THUNDERSTORMS POSSIBLE ALONG AND
AHEAD OF THE DRYLINE, AS THE MID LEVEL COLD POOL ADVANCES INTO
WESTERN KANSAS. NEW MODELS SHOW LIMITED CAPE OF 200 TO 500 J/KG
AND WITH SETTING OF THE SUN AND COOLING THE CAPE FIELDS QUICKLY
DECREASE. NOT EXPECTING ANY SEVERE WEATHER TONIGHT, HOWEVER SOME
SMALL HAIL IS POSSIBLE AND SHOULD BE LESS THAN DIME SIZE. WILL
KEEP 20 TO 40 PERCENT CHANCES FOR THUNDERSTORMS WITH THE HIGHER
CHANCES FROM WAKEENEY TO DODGE CITY AND EAST. STRONG SOUTH WINDS
OF 25 TO 35 MPH MAY CONTINUE THROUGH 9 OR 10 PM TONIGHT AND MAY
HAVE TO EXTEND THE WIND ADVISORY PAST THE CURRENT ONE THAT ENDS AT
7 PM CST. OVERNIGHT LOWS WILL BE FAIRLY MILD WITH GOOD MIXING
TONIGHT AND FROM THE LOWER 30S FAR WEST TO THE MID AND UPPER 30S
EAST ACROSS SOUTH CENTRAL KANSAS.
FOR SUNDAY WILL NEED ANOTHER WIND ADVISORY WITH WEST TO NORTHWEST
WINDS OF 30 TO NEAR 40 MPH WITH HIGHER GUSTS. WILL HAVE STRONG
MOMENTUM MIX DOWN POTENTIAL BEHIND THE EXITING UPPER LEVEL SHORTWAVE
TROUGH WITH MOSTLY SUNNY TO PARTLY CLOUDY SKIES. HIGHS IN THE MID TO
UPPER 40S LOOK REASONABLE WITH WARMER LOWER 50S IN THE COLDWATER TO
MEDICINE LODGE AREAS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 337 PM CST SAT FEB 9 2013
ANOTHER UPPER LEVEL TROUGH WILL DIG INTO THE SOUTHERN ROCKIES BY
MONDAY AFTERNOON AS COOL HIGH PRESSURE SETTLES INTO THE NORTHERN AND
CENTRAL PLAINS. SURFACE LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS
WEST TEXAS BY 00Z TUESDAY IN RESPONSE TO THE DIGGING SYSTEM. THE VARIOUS
MODELS HANDLE THE SYSTEM DIFFERENTLY BY MONDAY NIGHT AND TUESDAY, BUT
THE GFS/GEM AND ECMWF ARE IN REASONABLE AGREEMENT IN PLACING THE
500MB LOW CENTER AROUND WICHITA FALLS, TX BY 00Z WEDNESDAY.
THE GEM IS MORE CLOSED OFF THAN THE ECMWF AND THEREFORE HAS HIGHER
SNOW AMOUNTS ACROSS FAR SOUTHWEST KANSAS. THE SYSTEM WILL BE WEAKENING
BY TUESDAY EVENING AND OPENING UP SO THAT THE BEST CHANCE FOR SNOW
ACCUMULATIONS (PERHAPS 1 TO 2 INCHES) SHOULD BE FURTHER WEST
INCLUDING ELKHART, LIBERAL AND ULYSSES, WITH LESSER AMOUNTS TO THE
EAST AT MEDICINE LODGE. IT APPEARS THAT THE SNOW WILL OCCUR LATE
MONDAY NIGHT AND TUESDAY MORNING, WITH SOME CLEARING BY TUESDAY
AFTERNOON.
SOME WARMING CAN BE EXPECTED BY WEDNESDAY AHEAD OF THE NEXT
SHORTWAVE TROUGH. HIGHS SHOULD REACH INTO THE UPPER 40S TO LOWER 50S.
THIS SYSTEM IS ADVERTISED TO DIG INTO THE SOUTHERN ROCKIES PER
ECMWF, BUT THE OTHER MODELS ARE FURTHER EAST WITH THE TROUGH.
NONE OF THE MODELS ARE FAVORABLE FOR PRECIPITATION. A COLD SURGE WILL
PROGRESS DOWN THE PLAINS AHEAD OF THE SYSTEM THURSDAY NIGHT, BUT
NOT BEFORE TEMPERATURES REACH INTO THE UPPER 40S TO LOWER 50S ON
THURSDAY. COOLER HIGHS IN THE MID OR UPPER 30S CAN BE EXPECTED BY
FRIDAY. SINCE SURFACE HIGH PRESSURE WILL BE FIRMLY IN PLACE AHEAD
OF THE SYSTEM, LITTLE IN THE WAY OF LOW LEVEL THERMAL ADVECTIONS ARE
EXPECTED SO THAT SNOW IS UNLIKELY THIS FAR NORTH AND EAST.
TRANQUIL WEATHER CAN BE EXPECTED FOR FRIDAY AND INTO NEXT WEEKEND AS
A NORTHWESTERLY FLOW PATTERN DEVELOPS ACROSS THE WESTERN UNITED STATES.
LOW LEVEL MOISTURE FROM THE GULF WILL LIKELY STAY WELL TO THE SOUTHEAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1126 PM CST SAT FEB 9 2013
AREAS OF FOG AND IFR/LIFR CIGS WILL QUICKLY GIVE WAY TO VFR
CONDITIONS AS A DRYLINE MOVES EAST ACROSS WESTERN KANSAS EARLY
THIS MORNING. NAM AND HRRR BOTH SUGGEST VFR CONDITIONS AT GCK AT 06Z, AT
DDC AROUND 07Z, AND A BRIEF PERIOD VFR CONDITIONS AT HYS BETWEEN
8Z AND 11Z. LOW LEVEL MOISTURE POOLING BEHIND A COLD FRONT SURGING
SOUTHEAST ACROSS WESTERN KANSAS BEHIND THIS DRYLINE IS EXPECTED TO
PRODUCE SOME MVFR CIGS AT HYS AND GCK BETWEEN 11Z AND 15Z WITH
LOW VFR CIGS THEN BEING POSSIBLE AT HYS UNTIL 21Z. A TIGHT
PRESSURE GRADIENT WILL PERSIST ACROSS WESTERN KANSAS BEHIND THE
COLD FRONT. SUSTAINED NORTHWEST WINDS AT ALL THREE TAF SITES ARE
EXPECTED TO RANGE FROM 25 TO 30KTS. THE STRONGER WIND SPEEDS ARE
EXPECTED TO BE BETWEEN 17Z AND 22Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 47 21 42 / 20 0 0 0
GCK 31 45 19 39 / 20 0 0 0
EHA 30 47 19 38 / 30 0 10 10
LBL 31 49 20 41 / 20 0 10 10
HYS 34 45 22 41 / 20 0 0 0
P28 37 53 25 45 / 50 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 9 AM CST /8 AM MST/ TO 6 PM CST /5 PM MST/
SUNDAY FOR KSZ030-031-043>046-061>066-074>081-084>090.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...KRUSE
LONG TERM...FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS PADUCAH KY
305 AM CST SUN FEB 10 2013
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 305 AM CST SUN FEB 10 2013
LATEST SFC ANALYSIS SHOWS A SFC LOW OVER NW KANSAS AND A COLD FRONT
EXTENDING SOUTHWARD INTO OK AND TX. THIS LOW WILL SCOOT NORTHEAST
OVERNIGHT AND BE SITUATED OVER SOUTH CENTRAL NEBRASKA AT 12Z. PRIOR
TO 12Z...IT APPEARS WE WILL CONTINUE TO SEE A BAND OF SCATTERED
SHOWERS MOVE ACROSS THE REGION. BUT THE MAIN ACTION SHOULD BE AFTER
12Z...AS THE LOW TRAVELS FURTHER NORTHEAST TOWARD OMAHA NEBRASKA.
WE SHOULD SEE A NEARLY SOLID BAND OF RAIN WITH EMBEDDED STORMS
ROLL THROUGH HERE FROM WEST TO EAST THROUGHOUT THE DAY. IT APPEARS
THE TIMING OF THE RAIN/STORMS MAY HAVE TO BE SPED UP EVEN MORE. AT
0800Z...THE MAIN LINE OF CONVECTION WAS ALREADY LINED UP FROM SE
KS THROUGH CENTRAL OK AND INTO CENTRAL TX. THIS IS SEVERAL HOURS
AHEAD OF WHERE THE LATEST RUC ANALYSIS INDICATES IT SHOULD BE. AT
THIS RATE...THE LINE COULD BE ENTERING THE OZARKS AT 12Z. HAVE
ADJUSTED HOURLY POPS ACCORDINGLY AND ADJUSTMENTS WILL BE MADE
THROUGHOUT THE MORNING AS THINGS PROGRESS.
BY 00Z MONDAY...THE BEST CHANCES WILL LINGER IN OUR EASTERN
SECTIONS...AND BE EXITING THE ENTIRE AREA DURING THE EARLY EVENING
HOURS AS THE ACTUAL COLD FRONT PUSHES EAST OF THE CWA.
STILL NOT SEEING GREAT MOISTURE RETURN FORECAST OVER THE AREA...WITH
MODELS ONLY SHOWING DEWPOINTS IN THE LOWER TO MAYBE MID 50S (SOUTH).
LOOKING AT LATEST OBS...WE HAVE A WHILE BEFORE WE SEE THOSE 50S
DEWS. BETTER SFC BASED INSTABILTY IS DEFINITELY TO OUR SOUTH...BUT
MODELS ARE ABLE TO COME UP WITH A FEW HUNDRED JOULES/KG OF MU CAPE
DURING THE DAY. WIND FIELDS ARE DEFINITELY A CONCERN...AS THEY
STRENGTHEN THROUGHOUT THE DAY. BUT WITH LIMITED INSTABILITY AND
WEAK LAPSE RATES...OTHER THAN AN ISOLATED STG TO SVR STORM...THE
CHANCES FOR WIDESPREAD SEVERE WEATHER APPEAR VERY LOW.
HOWEVER...COULD STILL SEE SOME LOCALLY HEAVY RAIN...AS PW/S STILL
INDICATE A GOOD DEAL OF MOISTURE FOR THIS TIME OF YEAR.
THE GRADIENT SHOULD TIGHTEN UP AS WELL...AS WE COULD SEE SOME GUSTY
WINDS DEVELOP OVER THE NEXT SEVERAL HRS. MODEL SOUNDINGS AND LAYER
WIND PLOTS INDICATE 25 TO 30 KTS RIGHT OFF THE DECK...IF WE CAN MIX
THAT DOWN. THE WINDS WILL LIKELY STAY UP THROUGHOUT THE NIGHT AND
INTO MONDAY...AS THE MAIN SFC LOW TAKES ITS TIME MOVING ACROSS THE
GREAT LAKES REGION. THE STRONGEST WINDS WILL BE ACROSS OUR NORTHERN
COUNTIES ON MONDAY...BUT THEN START TO SLACKEN OFF BY THE END OF THE
DAY AND INTO THE NIGHT...AS HIGH PRESSURE BUILDS IN.
AS FAR AS TEMPS...WE WILL SEE A SPIKE IN LOW LEVEL TEMPS AHEAD OF
THE COLD FRONT TODAY...AND WE SHOULD SEE THE MERCURY RESPOND TO THIS
WITH HIGHS IN THE MID TO UPPER 50S. COULD EVEN SEE 60 DEG AT PLACES
LIKE POPLAR BLUFF MO...PADUCAH KY...AND HOPKINSVILLE KY MAYBE. A
PRETTY GOOD PUSH OF COLD AIR FILTERS IN BEHIND THE FRONT LATE
TONIGHT AND INTO MONDAY WHICH WILL KICK TEMPS BACK DOWN TO NEAR
NORMAL OR SLIGHTLY ABOVE NORMAL...WITH THE COLDEST READINGS IN THE
NORTH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 305 AM CST SUN FEB 10 2013
THERE ARE TWO MAIN ISSUES TO DEAL WITH IN THE EXTENDED PORTION OF
THE FORECAST. THE FIRST IS THE REMNANT FOUR CORNERS LOW/TROUGH
THAT IS EXPECTED TO MOVE EASTWARD OVER OUR REGION TUESDAY NIGHT.
THE SECOND IS WHAT TO DO WITH A SIGNIFICANT TROUGH THAT THE MODELS
DEVELOP OVER THE EASTERN THIRD OF THE COUNTRY LATE THIS WEEK AND
INTO NEXT WEEKEND.
THE GFS CONTINUES TO BE THE WETTEST FOR TUESDAY NIGHT...AND IT IS
SUPPORTED BY THE NAM. THESE MODELS ARE GENERATING A QUARTER INCH
OF LIQUID QPF. THE CANADIAN MODEL IS SLIGHTLY DRIER...WHILE THE
ECMWF IS QUITE DRY...BASICALLY ONLY SPITTING OUT A FEW HUNDREDTHS.
ALL OF THE MODELS HAVE RATHER COMPACT AND SHARP TROUGHS MOVING
THROUGH THE REGION...WITH THE BASE WELL SOUTH OF THE AREA. IT
WOULD NOT BE A STRETCH TO SEE A SMALL CLOSED LOW WITH THIS SYSTEM.
THIS WOULD PUT THE QUAD STATE REGION IN THE DEFORMATION
ZONE...WITH THE POTENTIAL FOR BANDING. THE BANDS WOULD LIKELY BE
ORIENTED EAST TO WEST...WHICH IS PARALLEL TO THE SYSTEM MOTION.
THIS COULD RESULT IN SOME AREAS GETTING A NICE SNOWFALL...A FEW
INCHES...WHILE OTHER AREAS CLOSE BY GET LITTLE OR NO SNOW
ACCUMULATION.
TEMPERATURE PROFILES CONTINUE TO INDICATE SATURATION DEEP ENOUGH
FOR SNOW TO FORM ALOFT...AND THE ONLY WARM LAYER BASED RIGHT AT
THE SURFACE. WITH THE FORCING INDICATED IN THE GFS/GEM/NAM...THE
LOW-LEVELS SHOULD COOL MORE THAN INDICATED IN THE MODELS. TEMPERATURES
MAY ONLY DROP TO AROUND THE FREEZING MARK...BUT THAT WOULD BE
SUFFICIENT TO ALLOW SNOW TO ACCUMULATE...IF IT FALLS HARD ENOUGH.
WE HAVE BEEN BITTEN BY THIS SORT OF THE THING IN THE PAST.
THE PRECIPITATION WILL LIKELY START AS RAIN AND MIX WITH AND
EVENTUALLY CHANGE OVER TO ALL SNOW. DID NOT WANT TO JUMP TOO FAR
FROM THE PREVIOUS FORECAST AT THIS TIME...SO JUST MENTIONED RAIN
AND SNOW TUESDAY NIGHT AND EARLY WEDNESDAY WITH NO ACCUMULATIONS.
HOWEVER...DID INCREASE POPS UP TO AROUND 40 IN THE SOUTH...AND
WILL MENTION THE POSSIBILITY OF ACCUMULATING SNOW IN THE HWO.
SOUTHWEST WINDS AND SEASONABLY MILD CONDITIONS ARE EXPECTED
WEDNESDAY AND THURSDAY...BEFORE THE MAJOR PATTERN SHIFT OCCURS. AS
IS THE CASE WITH MOST SIGNIFICANT PATTERN SHIFTS...THE MODELS ALL
EVENTUALLY GET THERE...BUT THEY ARE NOT LOCKED IN ON THE DETAILS OR
TIMING. THE ECMWF HAS DIVERGED FROM THE GFS AND GEM COMPARED TO
YESTERDAYS RUNS.
WHAT WE KNOW WITH SOME CONFIDENCE IS THAT THERE WILL BE LITTLE OR
NO LOW-LEVEL MOISTURE RETURN AHEAD OF THE INDIVIDUAL SHORT WAVE
TROUGHS THAT WILL CARVE OUT THE LARGER TROUGH. THE MODELS HAVE A
DIFFICULT TIME DEVELOPING ANY TANGIBLE PRECIPITATION...SO
ESPECIALLY GIVEN THE LACK OF MODEL AGREEMENT ON TIMING INDIVIDUAL
DISTURBANCES...HAVE ELECTED TO KEEP THE FORECAST DRY THURSDAY
NIGHT THROUGH SUNDAY.
THE CONSENSUS OF 00Z MODEL GUIDANCE BRINGS A SIGNIFICANT SHOT OF
COLD AIR INTO THE REGION FRIDAY INTO SATURDAY. IF THERE WERE TO BE
PRECIPITATION BEHIND THIS COLD FRONT...IT WOULD MOST LIKELY BE
LIGHT SNOW NEXT WEEKEND. THIS FORECAST HAS TEMPERATURES DROPPING
BELOW NORMAL FRIDAY AND THEN ONLY REACHING THE 30S FOR HIGHS ON
SATURDAY. SUNDAY WILL SEE SOME MODERATION...BUT TEMPERATURES WILL
STRUGGLE TO GET TO THE 40S.
&&
.AVIATION...
ISSUED AT 1035 PM CST SAT FEB 9 2013
LIGHT SHOWERS AND SPRINKLES CAME IN FASTER THAN FORECAST. WILL
CONTINUE WITH A VCSH / -RA MENTION THROUGH THE OVERNIGHT THEN
TRANSITION OVER TO HEAVIER SHOWERS AND THE POSSIBILITY OF TSRA
FOR SUNDAY. CONTINUED WITH MVFR TO MARGINAL IFR CONDITIONS WITH THE
CONVECTIVE ACTIVITY. WINDS SHOULD PICK UP AND BE GUSTY FROM THE SSE.
GUSTS IN THE 20-30KT RANGE EXPECTED.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...CW
LONG TERM...DRS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
437 AM EST SUN FEB 10 2013
.SYNOPSIS...
HIGH PRESSURE WILL SHIFT EAST TODAY WITH ONE MORE DRY DAY IN STORE
FOR THE REGION. A COLD FRONT WILL THEN BRING RAIN TO THE UPPER OHIO
VALLEY AS IT APPROACHES FROM THE WEST TONIGHT AND CROSSES THE AREA
ON MONDAY. BEHIND THE FRONT...SNOW SHOWERS WILL BE POSSIBLE ACROSS
PORTIONS OF THE AREA MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A BROAD 500MB RIDGE
CENTERED ACROSS THE OHIO VALLEY WITH OUR AREA IN A WEST-
NORTHWESTERLY FLOW JUST AHEAD OF THE AXIS OF THIS FEATURE. AT THE
SURFACE...AN ELONGATED AREA OF HIGH PRESSURE EXTENDS FROM NEW YORK
INTO THE EASTERN CAROLINAS. DESPITE A DEEP LAYER OF DRY AIR THE
SURFACE THAT HAS BROUGHT CLEAR SKIES OVERNIGHT...STRATOCUMULUS IS
BEGINNING TO SPILL IN FROM THE SOUTHWEST AHEAD OF THE NEXT
FRONTAL SYSTEM.
TODAY...THE MID-LEVEL RIDGE WILL CROSS THE UPPER OHIO VALLEY AS A
SURFACE LOW MOVES INTO THE UPPER MID-WEST AND SWINGS A COLD FRONT
ACROSS THE MISSOURI VALLEY. 700-250MB MOISTURE WILL ADVECT INTO THE
AREA WELL AHEAD OF THE FRONT...INCREASING SKY COVERAGE TO MOSTLY
CLOUDY TODAY. A SOUTHWESTERLY LOW-LEVEL FLOW WILL BECOME MORE SOUTHERLY
BY THIS EVENING...ENHANCING WAA WITH 850MB TEMPS INCREASING TO
5-7C ACROSS THE AREA BY 00Z MONDAY. TEMPS ARE A FEW DEGREES WARMER
THAN MAV/MET GUIDANCE...WITH HIGHS RANGING FROM THE MID 40S NORTH
OF I-80 AND ACROSS THE HIGHER ELEVATIONS OF THE LAUREL HIGHLANDS
TO THE MID 50S ACROSS NORTH-CENTRAL WV AND PORTIONS OF EASTERN
OHIO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
NAM/GFS/SREF 700MB OMEGA FIELDS INDICATE SUFFICIENT FORCING FOR
WIDESPREAD PRE-FRONTAL SHOWERS TO BEGIN TO PUSH INTO EASTERN OHIO
AFTER 00Z TONIGHT...REACHING THE PITTSBURGH METRO BY AROUND 06Z.
NUMEROUS SHOWERS WILL CONTINUE WITH WAA AHEAD OF THE FRONT UNTIL
AROUND 15Z WHEN THE COLD FRONT REACHES THE AREA.
THUS...CATEGORICAL POPS ARE FORECAST IN THIS TIME FRAME. WITH
TEMPS WARMING INTO THE 40S AND 50S ACROSS THE AREA TODAY AND WAA
OVERNIGHT...ONLY CHANCE OF SUB-FREEZING TEMPS WITH THE ONSET OF
RAIN LOOKS TO BE WHERE COLD AIR MAY HOLD IN FOREST/JEFFERSON
COUNTIES AND THE VALLEYS OF GARRETT/TUCKER COUNTIES. THUS...A FEW
HOURS OF FREEZING RAIN ARE FORECAST DURING THE PRE-DAWN HOURS
MONDAY THERE. THIS REMAINS MENTIONED IN THE HWO.
TEMPS WILL ONLY DROP SLIGHTLY SUNDAY NIGHT...WITH LOWS ARE NAM/GFS
BLEND...RANGING FROM THE LOWER 30S IN THE LAUREL HIGHLANDS/ALLEGHENY
FRONT TO THE LOWER 40S IN EASTERN OHIO AND NORTHERN WV. BEFORE THE
FRONT PUSHES THROUGH...HIGHS EARLY ON MONDAY WILL RANGE FROM THE
MID 40S NORTH OF PITTSBURGH TO THE MID 50S IN NORTH-CENTRAL WV.
BEHIND THE FRONT...CAA WILL BE WEAK AS THE LOW-LEVEL FLOW SHIFTS TO
SOUTHWESTERLY IN THE 18Z-00Z MONDAY TIME FRAME. THUS...THE CHANCE OF
RAIN SHOWERS WILL LOWER WITH DECREASING THICKNESSES FINALLY
ALLOWING FOR A CHANGE OVER TO SNOW AFTER 00Z TUESDAY. BEST CHANCE
FOR SNOW SHOWERS MONDAY NIGHT WILL BE ALONG THE LAUREL
HIGHLANDS/ALLEGHENY FRONT OF WV/MD/PA WHERE SOME UPSLOPING
ENHANCEMENT WILL OCCUR. STILL...LITTLE OR NO ACCUMULATION IS
EXPECTED AS GROUND TEMPS WILL BE RELATIVELY WARM AND PRECIPITATION
LIGHT. LOWS ARE A MAV/MET BLEND ON MONDAY NIGHT...AROUND 5 DEGREES
ABOVE SEASONAL NORMALS.
TUESDAY AND TUESDAY NIGHT...GFS/NAM INDICATE A CLOSED UPPER LOW
WILL PASS NORTH OF THE AREA EARLY ON TUESDAY AND LEAVE THE AREA IN
A CYCLONIC...WEST-NORTHWESTERLY FLOW WITH SOME WEAK VORT ENERGY
SWINGING ACROSS AREAS NORTH OF PITTSBURGH. ALTHOUGH THE VORT WILL
PROVIDE FORCING...AVAILABLE MOISTURE WILL BE LIMITED IN A
WEST-NORTHWESTERLY FLOW OVER A MOSTLY FROZEN LAKE ERIE. THUS WENT
WITH CHC POPS NORTH OF I-80 ON TUESDAY. HIGH PRESSURE BUILDING IN
FROM THE WEST WILL THEN ALLOW FOR A DRY FORECAST ACROSS THE AREA
ON TUESDAY NIGHT. TEMPS WILL BE NEAR NORMAL SEASONAL VALUES
TUESDAY AND TUES NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE MODELS ARE IN FAIRLY GOOD AGREEMENT AT THE START OF THE PERIOD
AS AN UPPER LEVEL POSITIVELY TILTED TROUGH SWINGS TOWARDS THE OHIO
VALLEY. AT THE SURFACE...BOTH THE ECMWF AND GFS TRANSLATE THIS TO
THE DEVELOPMENT ACROSS THE MID ATLANTIC COASTLINE. WHAT DIFFERS IS
THIS LOW PLACEMENT...WITH THE GFS BRINGING THE LOW AND PRECIP CLOSE
ENOUGH TO CLIP THE SOUTHEASTERN HALF OF THE REGION...AND THE
ECMWF KEEPING THE SYSTEM JUST A BIT FURTHER SOUTH.
WITH BETTER RUN TO RUN CONSISTENCY WITH THE GFS AND THE NEWEST ECMWF
AND GEFS SUGGESTING A SLIGHTLY NORTHWARD TRACK...HEDGED MORE TOWARDS
THE 12Z GFS AND MEX GUIDANCE THROUGH THIS PERIOD.
THE MODELS THEN HAVE LARGER DIFFERENCES IN REGARDS TO THE SYSTEM
PROGGED FOR FRI/SAT. WITH THE CONTINUITY BETWEEN RUNS DEGRADING WITH
THIS SECOND SYSTEM...OPTED TO TAKE A SOLUTION CLOSER TO HPC BUT
REMAINED CLOSE TO MEX GUIDANCE FOR THE REMAINDER OF THE PERIOD. IN
GENERAL KEPT TEMPERATURES NEAR NORMAL THROUGH THE PERIOD.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
HIGH CLOUDS WILL SLOWLY START TO MOVE INTO THE AREA FROM THE
SOUTHWEST OVERNIGHT TOWARD MORNING. THESE WILL SLOWLY THICKEN
THROUGH THE DAY AS THE GRADIENT FORCES MORE SOUTHEASTERLY FLOW
OVER THE AREA. DEEPER MOISTURE APPROACHES AFTER 11/02Z ON THE NOSE
OF A STRONG SSW LOW LEVEL JET OF AROUND 50-55 KTS. THIS WILL BRING
LOW LEVEL WIND SHEAR OVER ALL SITES STARTING BETWEEN 11/02Z AND
11/05Z ROUGHLY COINCIDENT WITH THE START OF PRECIPITATION. FRIES
.OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
RESTRICTIONS WILL RETURN IN RAIN SUNDAY NIGHT AND MONDAY...AND
CONTINUE IN SNOW SHOWERS MONDAY NIGHT AND TUESDAY. ANOTHER SYSTEM
COULD CLIP LBE AND MGW WEDNESDAY/THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
109 AM EST SUN FEB 10 2013
.SYNOPSIS...
HIGH PRESSURE WILL SHIFT EAST TODAY WITH ONE MORE DRY DAY IN STORE
FOR THE REGION. A COLD FRONT WILL THEN BRING RAIN TO THE UPPER OHIO
VALLEY AS IT APPROACHES FROM THE WEST TONIGHT AND CROSSES THE AREA
ON MONDAY. BEHIND THE FRONT...SNOW SHOWERS WILL BE POSSIBLE ACROSS
PORTIONS OF THE AREA MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AN ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED WITH LITTLE
CHANGE TO THE FORECAST EARLY THIS MORNING.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A BROAD 500MB RIDGE
CENTERED ACROSS THE OHIO VALLEY WITH OUR AREA IN A
WEST-NORTHWESTERLY FLOW JUST AHEAD OF THE AXIS OF THIS FEATURE. AT
THE SURFACE...AN ELONGATED AREA OF HIGH PRESSURE EXTENDS FROM NEW
YORK INTO THE EASTERN CAROLINAS. WITH DEEP SUBSIDENCE AND A DRY
LAYER ALOFT...SKIES ARE MOSTLY CLEAR ACROSS THE AREA. THE EXCEPTION
IS CIRRUS BEGINNING TO SPILL IN FROM THE SOUTHWEST AHEAD OF THE
NEXT FRONTAL SYSTEM.
TODAY...THE MID-LEVEL RIDGE WILL CROSS THE UPPER OHIO VALLEY AS A
SURFACE LOW MOVES INTO THE UPPER MID-WEST AND SWINGS A COLD FRONT
ACROSS THE MISSOURI VALLEY. 700-250MB MOISTURE WILL ADVECT INTO THE
AREA WELL AHEAD OF THE FRONT...INCREASING SKY COVERAGE TO MOSTLY
CLOUDY BY EVENING. A SOUTHWESTERLY LOW-LEVEL FLOW WILL BECOME MORE
SOUTHERLY BY THIS EVENING...ENHANCING WAA WITH 850MB TEMPS
INCREASING TO 5-7C ACROSS THE AREA BY 00Z MONDAY. TEMPS ARE A FEW
DEGREES WARMER THAN MAV/MET GUIDANCE...WITH HIGHS RANGING FROM
THE MID 40S NORTH OF I-80 AND ACROSS THE HIGHER ELEVATIONS OF THE
LAUREL HIGHLANDS TO THE MID 50S ACROSS NORTH-CENTRAL WV AND
PORTIONS OF EASTERN OHIO.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
MODELS IN GOOD OVERALL AGREEMENT ON OCCLUDED BOUNDARY QUICKLY
MOVING ACROSS THE UPPER OHIO VALLEY SUNDAY NIGHT INTO EARLY MONDAY
AS PARENT LOW PRESSURE SPINS ACROSS THE GREAT LAKES. RAIN WILL
OVERSPREAD THE AREA SUNDAY NIGHT AND CONTINUE INTO EARLY MONDAY
BEFORE TRANSITIONING TO SHOWERS AS BOUNDARY EXITS.
MODEL SOUNDINGS CONTINUE TO SHOW A BRIEF PERIOD OF FREEZING RAIN
POSSIBLE ACROSS THE RIDGES AND NORTHEAST AREAS ESPECIALLY AT THE
ONSET OF OF THE RAIN. HAVE ONLY LEFT A CHANCE OF FREEZING
RAIN IN FORECAST AS TEMPERATURES SUNDAY WILL BE QUITE WARM WITH A
GOOD AMOUNT OF SUNSHINE. SURFACE WINDS WILL BE SOUTHEAST TO SOUTH
AS THE NIGHT GOES ON AND WITH CONTINUED WARM ADVECTION ANY LOW
LEVEL COLD AIR REMAINING SHOULD BE SCOURED OUT. TEMPERATURES
SUNDAY NIGHT WILL FALL A BIT EARLY THEN HOLD STEADY OR RISE.
A FAST SHOT OF RAIN WITH QPF ONE QUARTER TO ONE HALF INCH SHOULD
NOT CAUSE ANY HYDRO PROBLEMS. BEHIND BOUNDARY MONDAY AFTERNOON
COLD ADVECTION WILL RETURN BY LATE DAY WITH SOME MOISTURE WRAPPING
UNDERNEATH GREAT LAKES LOW. THIS WILL KEEP A CHANCE OF SHOWERS
MONDAY AFTERNOON CHANGING TO SNOW SHOWERS AND DIMINISHING INTO
TUESDAY.
TEMPERATURES WILL TRANSITION BACK TO NORMAL TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE MODELS ARE IN FAIRLY GOOD AGREEMENT AT THE START OF THE PERIOD
AS AN UPPER LEVEL POSITIVELY TILTED TROUGH SWINGS TOWARDS THE OHIO
VALLEY. AT THE SURFACE...BOTH THE ECMWF AND GFS TRANSLATE THIS TO
THE DEVELOPMENT ACROSS THE MID ATLANTIC COASTLINE. WHAT DIFFERS IS
THIS LOW PLACEMENT...WITH THE GFS BRINGING THE LOW AND PRECIP CLOSE
ENOUGH TO CLIP THE SOUTHEASTERN HALF OF THE REGION...AND THE
ECMWF KEEPING THE SYSTEM JUST A BIT FURTHER SOUTH.
WITH BETTER RUN TO RUN CONSISTENCY WITH THE GFS AND THE NEWEST ECMWF
AND GEFS SUGGESTING A SLIGHTLY NORTHWARD TRACK...HEDGED MORE TOWARDS
THE 12Z GFS AND MEX GUIDANCE THROUGH THIS PERIOD.
THE MODELS THEN HAVE LARGER DIFFERENCES IN REGARDS TO THE SYSTEM
PROGGED FOR FRI/SAT. WITH THE CONTINUITY BETWEEN RUNS DEGRADING WITH
THIS SECOND SYSTEM...OPTED TO TAKE A SOLUTION CLOSER TO HPC BUT
REMAINED CLOSE TO MEX GUIDANCE FOR THE REMAINDER OF THE PERIOD. IN
GENERAL KEPT TEMPERATURES NEAR NORMAL THROUGH THE PERIOD.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
HIGH CLOUDS WILL SLOWLY START TO MOVE INTO THE AREA FROM THE
SOUTHWEST OVERNIGHT TOWARD MORNING. THESE WILL SLOWLY THICKEN
THROUGH THE DAY AS THE GRADIENT FORCES MORE SOUTHEASTERLY FLOW
OVER THE AREA. DEEPER MOISTURE APPROACHES AFTER 11/02Z ON THE NOSE
OF A STRONG SSW LOW LEVEL JET OF AROUND 50-55 KTS. THIS WILL BRING
LOW LEVEL WIND SHEAR OVER ALL SITES STARTING BETWEEN 11/02Z AND
11/05Z ROUGHLY COINCIDENT WITH THE START OF PRECIPITATION. FRIES
.OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
RESTRICTIONS WILL RETURN IN RAIN SUNDAY NIGHT AND MONDAY...AND
CONTINUE IN SNOW SHOWERS MONDAY NIGHT AND TUESDAY. ANOTHER SYSTEM
COULD CLIP LBE AND MGW WEDNESDAY/THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
1257 AM EST SUN FEB 10 2013
.SYNOPSIS...
ISSUED AT 420 PM EST SAT FEB 9 2013
HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER ACROSS THE
REGION THROUGH EARLY SUNDAY. BEYOND THAT...A STORM SYSTEM WILL
ORGANIZE OVER THE PLAINS STATES AND PUSH NORTHEAST TOWARDS THE GREAT
LAKES. THIS WILL BRING A WINTRY MIX OF RAIN...SNOW...SLEET...AND
FREEZING RAIN TO THE REGION BY LATE SUNDAY AND SUNDAY NIGHT.
PRECIPITATION WILL CHANGE TO ALL SNOW ON MONDAY AS COOLER AIR MOVES
BACK INTO THE REGION. MAINLY QUIET WEATHER WILL RETURN FOR THE
MIDDLE PORTION OF NEXT WEEK...WITH SEASONAL TEMPERATURES EXPECTED.
&&
.UPDATE...
ISSUED AT 1255 AM EST SUN FEB 10 2013
UPDATES THIS HOUR: VERY MINOR CHANGES TO SKY COVER OVER NW LOWER
WITH SOMEWHAT LARGER ADJUSTMENTS TO TEMPERATURES BASED ON VERY
LARGE SPREAD ACROSS THE CWA /-4 IN ALGER ATTM WITH THE COAST OF NW
LOWER IN THE MID-UPPER 20S/. EXPECT THE COOL SPOTS TO GRADUALLY
RE-COUPLE AND WARM OVER THE NEXT FEW HOURS...BUT OTHERWISE...
QUIET WEATHER CONTINUES THROUGH DAYBREAK.
UPDATE ISSUED AT 742 PM EST SAT FEB 9 2013
MADE SOME EARLY TWEAKS TO FORECAST. COMBINATION OF SHALLOW LAKE
CLOUDS OVER LAKE MICHIGAN AND PATCHY MID LEVEL AC WILL TEND TO
KEEP EASTERN UPPER ON THE CLOUDY SIDE OVERNIGHT (ASSUMING LAKE
MICHIGAN CLOUDS GET ADVECTED EASTWARD A BIT). AT THE SAME TIME...
CURRENTLY NOT AS CONCERNED WITH LOW CLOUDS SPILLING INTO NORTHWEST
LOWER WITH STRENGTHENING SOUTHEAST SURFACE FLOW OVER THE LOWER
PENINSULA. BOTH RAP AND NAM-WRF HAVING BOUNDARY LAYER ISSUES...RAP
FORECAST SOUNDINGS TOO COLD (SUGGESTING IT SHOULD ALREADY BE IN
THE MID TEENS AT GLR/GOV/CAD WHEN IN REALITY TEMPERATURES ARE 8-10F
WARMER)...AND NAM-WRF SOUNDINGS ARE TOO MOIST. THINK THERE WILL BE
ENOUGH OF A GRADIENT TO KEEP THINGS FROM DE-COUPLING AND RADIATING
LIKE MAD. SO HAVE NUDGED TEMPERATURE TRENDS UP A BIT (AND MINIMUM
TEMPERATURES BY EXTENSION).
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 420 PM EST SAT FEB 9 2013
ELONGATED SFC RIDGE AXIS JUST OFF TO THE EAST OF THE STATE THIS
AFTERNOON WITH SOUTHERLY RETURN FLOW STRENGTHENING ACROSS THE
STATE. ABUNDANT SUN ACROSS NRN LOWER MICHIGAN TODAY. REMAINING LAKE
CLOUDS OVER LAKE MICHIGAN STILL STILL JUST OFFSHORE OF LOWER
MICHIGAN BUT SHOWING A LITTLE SIGN OF INCHING BACK TOWARD SHORE.
UPPER MICHIGAN GETTING RIPPED OFF HOWEVER...AS SOUTHERLY MEAN LOW
LEVEL WIND IS DRAGGING LAKE CLOUDS UP THROUGH A GOOD PART OF EASTERN
UPPER. KERY REPORTED 5SM -SN ABOUT TWO HOURS AGO. SO...STILL
GETTING SOME SHALLOW NUISANCE LAKE SNOWS.
TONIGHT...MORE NUISANCE STUFF TO WORRY ABOUT THAN ANYTHING. LAKE
CLOUDS OVER SRN LAKE MICHIGAN ARE STARTING TO ERODE FROM THE SOUTH
AS WARMER LOW LEVEL AIR MAKES ITS WAY UP THE LAKE. HOWEVER...STILL A
WINDOW OF OPPORTUNITY TO GET SOME LAKE CLOUDS INTO THE PARTS OF NW
LOWER MICHIGAN THIS EVENING AS WE GET MORE OF A WESTERLY COMPONENT
TO THE WIND...ALTHOUGH REMAINING LAKE CLOUDS SHOULD FURTHER ERODE
AWAY FROM THE SOUTH AS WARMER LOW LEVEL AIR WORKS INTO REGION.
SECOND PROBLEM IS STRATUS AND/OR FOG POTENTIAL. AS WE GET MORE OF A
WESTERLY COMPONENT OFF LAKE MICHIGAN...FORECAST SOUNDINGS SHOW
ADDITIONAL MOISTURE GETTING PULLED INTO NRN LOWER MICHIGAN THROUGH
THE NIGHT (DEW POINT TRACE FOLDS OVER-TOP THE BOUNDARY LAYER). THIS
SUGGESTS THE POSSIBILITY OF DEVELOPMENT OF LOW STRATUS AND/OR FOG AS
WARM/MOIST LAYER ALOFT ADVECTS OVER A COLD BOUNDARY LAYER. DIDN`T GO
MOSTLY CLOUDY...BUT DO HAVE AN INCREASE IN CLOUD COVER (PARTLY
CLOUDY) THIS EVENING.
TEMPS...YET ANOTHER ISSUE. HAVE MAINLY CLEAR SKIES INTERIOR GOING
INTO THE EVENING WHICH WILL ALLOW TEMPS TO DROP QUICKLY AGAIN. BUT
TEMP FREE-FALL WILL BE THROTTLED COMPARED TO LAST NIGHT BY STRONGER
FLOW OFF THE SFC. DON`T FORESEE BELOW ZERO READINGS TONIGHT GIVEN THE
STRONGER WINDS AND CLOUD POTENTIAL...BUT SOME OF THE COLDER SPOTS
DIPPING INTO THE SINGLE DIGITS CERTAINLY NOT OUT OF THE
QUESTION.
SUNDAY...ANY CIGS/FOG WILL ERODE DURING THE MORNING HOURS AS WARMER
AIR CONTINUES TO WORK INTO THE REGION. NEXT WEATHER MAKER WILL BE
WORKING INTO THE MIDWEST THROUGH THE COURSE OF THE DAY. STRONG PULSE
OF WARM ADVECTION EXPECTED TO PUSH PRECIP UP THROUGH THE STATE...
GENERALLY BETWEEN THE 21Z AND 00Z TIME FRAME (MODEL CONSENSUS IS
PRETTY CLOSE)...WHICH SEEMS REASONABLE GIVEN THE VERY DRY AIR IN
PLACE DOWNSTAIRS INITIALLY. BUT ONCE AGAIN...WARM NOSE ALOFT
ROCKETING INTO THE REGION WILL ALSO BRING ANOTHER ROUND OF P-TYPE
ISSUES TO NORTHERN MICHIGAN. COLD TEMPS TO START AND SFC TEMPS JUST
INCHING TO AROUND THE FREEZING MARK WILL PRESENT A RAIN/FREEZING
RAIN PROBLEM OVER THE HIGH TERRAIN/NE LOWER MICHIGAN. SNOW/SLEET/
FREEZING RAIN MIX IN EASTERN UPPER WITH SLIGHTLY COLDER AIR ALOFT.
DON`T THINK WE GET WARNING CRITERIA PRECIP OF ANY TYPE. BUT MAY
ULTIMATELY NEED SOME ADVISORIES ISSUED...BUT WILL ALLOW LATER SHIFTS
TO TAKE CARE OF THAT.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 420 PM EST SAT FEB 9 2013
PROGRESSIVE PATTERN SET TO CONTINUE...COURTESY OF ONE AGITATED
PACIFIC PATTERN (WHICH WATER VAPOR IMAGERY SHOWS COVERED WITH A
VIRTUAL WAVE-TRAIN OF STRONG TROUGH/RIDGE COUPLETS) AND LACK OF ANY
DOWNSTREAM NORTH ATLANTIC BLOCKING. THIS AGGRESSIVE FLOW WILL HELP
KICK OUT CURRENT FOUR-CORNERS WAVE...WHICH WILL CUT ACROSS THE
NORTHERN LAKES SUNDAY NIGHT INTO MONDAY...BRINGING A PLETHORA OF
DIFFERENT WEATHER TYPES. PLENTY OF SUPPORT FOR A MUCH TAMER PERIOD
OF WEATHER HEADING THROUGH THE MIDDLE OF NEXT WEEK AS AREA BECOMES
CENTERED BETWEEN ACTIVE STORM TRACKS. FORECAST CONCERNS CONTINUE TO
FOCUS ON WEATHER TYPES AND POTENTIAL IMPACTS FROM SUNDAY NIGHT AND
MONDAYS SYSTEM.
AGGRESSIVE PUSH OF WAA/ISENTROPIC UPGLIDE ON NOSE OF 50+ KNOT LOW
LEVEL JET WILL RACE ACROSS THE AREA SUNDAY EVENING...ACCOMPANIED BY
AN AREA OF MODERATE PRECIP. WAA NOT AS AGGRESSIVE AT THE
SURFACE...ALTHOUGH STOUT OFF THE DECK WARM NOSE ENSURES ANYTHING
REACHING THE SURFACE ACROSS NORTHERN LOWER WILL BE OFF THE LIQUID
VARIETY. SOME LINGERING NEAR FREEZING AREAS/COLD SKIN TEMPERATURES
MAY CONTINUE TO RESULT IN POCKETS OF FREEZING RAIN ACROSS THE
INTERIOR HIGHLANDS DURING THE EARLY EVENING...WITH PLAIN RAIN
FALLING ELSEWHERE. EVAP COOLING ALLOWS COLUMN TEMPERATURES TO
STRADDLE THE FREEZING LINE NORTH OF THE BRIDGE...SUGGESTING
PRIMARILY A SNOW OR SNOW/SLEET MIXTURE AS STEADIEST/HEAVIEST PRECIP
ARRIVES. WHILE SNOW TO LIQUID RATIOS WILL REMAIN LOW...A SEVERAL
HOUR PERIOD OF POTENTIALLY HEAVY SNOWFALL RATES WILL LIKELY PRODUCE
A FEW INCHES (2 TO 5) ACROSS INTERIOR EASTERN UPPER. STRONG
SHORTWAVE AND ATTENDANT SURFACE LOW PIVOT INTO CENTRAL UPPER
MICHIGAN BY MONDAY MORNING...ALLOWING A PRETTY RESPECTABLE MID LEVEL
DRY SLOT TO OVERSPREAD NORTHERN LOWER MICHIGAN. THIS SHOULD BRING
MORE OF A VERY LIGHT RAIN/DRIZZLE SCENARIO OVERNIGHT. MOISTURE
REMAINS DEEPER NORTH OF THE STRAITS ALONG AND NORTH OF SURFACE WARM
FRONT. SNOW/SLEET MIXTURE SHOULD TRANSITION MORE TO A
RAIN/SLEET/FREEZING RAIN/SNOW MIXTURE AS 900MB CENTERED WARM NOSE
INCREASES TO +2C...WITH JUST MINIMAL ADDITIONAL SNOW ACCUMULATIONS
AFTER MIDNIGHT.
SYSTEM CONTINUES TO OCCLUDE/WEAKEN AS IT PUSHES OFF INTO CANADA
LATER MONDAY AND MONDAY NIGHT. DRY SLOT FOLLOWS SUITE...WITH DEEPER
MOISTURE ALONG SECONDARY TROUGH AXIS PUSHING INTO THE REGION THROUGH
THE DAY. BACKSIDE CAA NOT NEARLY AS AGGRESSIVE...SUGGESTING A SLOWER
TRANSITION BACK TO SNOW THAN WHAT IT APPEARED LIKE YESTERDAY. COLD
LAYER DEEPENS ENOUGH TO SUPPORT PRIMARILY SNOW BY LATE
AFTERNOON...WITH SOME MINOR (SUB ONE INCH) ACCUMULATIONS
POSSIBLE...ESPECIALLY WHERE WEST FLOW UPSLOPE IS MAXIMIZED INTO THE
HIGHLANDS. REAL MARGINAL CONDITIONS FOR NW-WNW LAKE ENHANCEMENT
MONDAY NIGHT WITH DELTA T/S FLIRTING WITH 13C AND INVERSION LEVELS
AT H85 LEVEL. PERHAPS AN ADDITIONAL INCH OF SNOW IN FAVORED
AREAS...OTHERWISE JUST SOME SCATTERED LIGHT SNOW SHOWERS AND
FLURRIES.
OTHER THAN SOME LINGERING LIGHT SNOW SHOWERS TUESDAY MORNING...JUST
NOT A WHOLE LOT TOO TALK ABOUT HEADING INTO THURSDAY AS NORTHERN
LAKES BECOMES CENTERED BETWEEN NORTHERN AND SOUTHERN STREAM WAVES.
IMAGINE A FEW FLURRIES/LIGHT SNOW SHOWERS ARE POSSIBLE LATER
WEDNESDAY INTO WEDNESDAY NIGHT AS SOUTHERN PORTION OF NORTHERN WAVE
SWEEPS ACROSS...BUT NOT WORTHY OF A SPECIFIC MENTION IN THIS
FORECAST. POTENTIAL FOR A STRONGER HYBRID CLIPPER TYPE SYSTEM TO
ARRIVE TO END THE EXTENDED...BRINGING ADDITIONAL LIGHT SNOW CHANCES.
TEMPERATURES TO AVERAGE NEAR TO ABOVE NORMAL WEDNESDAY THROUGH
FRIDAY...WITH A SHOT OF COOLER AIR ARRIVING TO START NEXT WEEKEND
(SUBJECT TO MANY CHANGES...OF COURSE).
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1148 PM EST SAT FEB 9 2013
BRIEF PERIOD OF MVFR CEILINGS AT MBL THROUGH 08Z-09Z...OTHERWISE
VFR UNTIL SUNDAY AFTERNOON AS CLOUDS LOWER AND PRECIPITATION MOVES
IN FROM THE SOUTHWEST. COULD START AS A PERIOD OF FREEZING
RAIN/SLEET MAINLY AT APN/PLN.
&&
.MARINE...
ISSUED AT 420 PM EST SAT FEB 9 2013
SOUTHERLY WINDS WILL INCREASE TONIGHT AND FURTHER THROUGH THE DAY SUNDAY
IN ADVANCE OF ANOTHER LOW PRESSURE SYSTEM THAT WILL TRACK THROUGH
THE NRN LAKES LATE SUNDAY INTO MONDAY. AT THIS POINT...WITH WARMING
TEMPS OVER THE LAKES/INCREASING LAKE STABILITY...DON`T THINK WIND
GUSTS WILL REACH GALE FORCE WITH THIS SYSTEM. HOWEVER...A HANDFUL
OF SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR SUNDAY AND
SUNDAY NIGHT.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JA
SYNOPSIS...NTS
SHORT TERM...TBA
LONG TERM...MSB
MARINE...TBA
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1150 PM EST SAT FEB 9 2013
.SYNOPSIS...
ISSUED AT 420 PM EST SAT FEB 9 2013
HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER ACROSS THE
REGION THROUGH EARLY SUNDAY. BEYOND THAT...A STORM SYSTEM WILL
ORGANIZE OVER THE PLAINS STATES AND PUSH NORTHEAST TOWARDS THE GREAT
LAKES. THIS WILL BRING A WINTRY MIX OF RAIN...SNOW...SLEET...AND
FREEZING RAIN TO THE REGION BY LATE SUNDAY AND SUNDAY NIGHT.
PRECIPITATION WILL CHANGE TO ALL SNOW ON MONDAY AS COOLER AIR MOVES
BACK INTO THE REGION. MAINLY QUIET WEATHER WILL RETURN FOR THE
MIDDLE PORTION OF NEXT WEEK...WITH SEASONAL TEMPERATURES EXPECTED.
&&
.UPDATE...
ISSUED AT 742 PM EST SAT FEB 9 2013
MADE SOME EARLY TWEAKS TO FORECAST. COMBINATION OF SHALLOW LAKE
CLOUDS OVER LAKE MICHIGAN AND PATCHY MID LEVEL AC WILL TEND TO
KEEP EASTERN UPPER ON THE CLOUDY SIDE OVERNIGHT (ASSUMING LAKE
MICHIGAN CLOUDS GET ADVECTED EASTWARD A BIT). AT THE SAME TIME...
CURRENTLY NOT AS CONCERNED WITH LOW CLOUDS SPILLING INTO NORTHWEST
LOWER WITH STRENGTHENING SOUTHEAST SURFACE FLOW OVER THE LOWER
PENINSULA. BOTH RAP AND NAM-WRF HAVING BOUNDARY LAYER ISSUES...RAP
FORECAST SOUNDINGS TOO COLD (SUGGESTING IT SHOULD ALREADY BE IN
THE MID TEENS AT GLR/GOV/CAD WHEN IN REALITY TEMPERATURES ARE 8-10F
WARMER)...AND NAM-WRF SOUNDINGS ARE TOO MOIST. THINK THERE WILL BE
ENOUGH OF A GRADIENT TO KEEP THINGS FROM DE-COUPLING AND RADIATING
LIKE MAD. SO HAVE NUDGED TEMPERATURE TRENDS UP A BIT (AND MINIMUM
TEMPERATURES BY EXTENSION).
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 420 PM EST SAT FEB 9 2013
ELONGATED SFC RIDGE AXIS JUST OFF TO THE EAST OF THE STATE THIS
AFTERNOON WITH SOUTHERLY RETURN FLOW STRENGTHENING ACROSS THE
STATE. ABUNDANT SUN ACROSS NRN LOWER MICHIGAN TODAY. REMAINING LAKE
CLOUDS OVER LAKE MICHIGAN STILL STILL JUST OFFSHORE OF LOWER
MICHIGAN BUT SHOWING A LITTLE SIGN OF INCHING BACK TOWARD SHORE.
UPPER MICHIGAN GETTING RIPPED OFF HOWEVER...AS SOUTHERLY MEAN LOW
LEVEL WIND IS DRAGGING LAKE CLOUDS UP THROUGH A GOOD PART OF EASTERN
UPPER. KERY REPORTED 5SM -SN ABOUT TWO HOURS AGO. SO...STILL
GETTING SOME SHALLOW NUISANCE LAKE SNOWS.
TONIGHT...MORE NUISANCE STUFF TO WORRY ABOUT THAN ANYTHING. LAKE
CLOUDS OVER SRN LAKE MICHIGAN ARE STARTING TO ERODE FROM THE SOUTH
AS WARMER LOW LEVEL AIR MAKES ITS WAY UP THE LAKE. HOWEVER...STILL A
WINDOW OF OPPORTUNITY TO GET SOME LAKE CLOUDS INTO THE PARTS OF NW
LOWER MICHIGAN THIS EVENING AS WE GET MORE OF A WESTERLY COMPONENT
TO THE WIND...ALTHOUGH REMAINING LAKE CLOUDS SHOULD FURTHER ERODE
AWAY FROM THE SOUTH AS WARMER LOW LEVEL AIR WORKS INTO REGION.
SECOND PROBLEM IS STRATUS AND/OR FOG POTENTIAL. AS WE GET MORE OF A
WESTERLY COMPONENT OFF LAKE MICHIGAN...FORECAST SOUNDINGS SHOW
ADDITIONAL MOISTURE GETTING PULLED INTO NRN LOWER MICHIGAN THROUGH
THE NIGHT (DEW POINT TRACE FOLDS OVER-TOP THE BOUNDARY LAYER). THIS
SUGGESTS THE POSSIBILITY OF DEVELOPMENT OF LOW STRATUS AND/OR FOG AS
WARM/MOIST LAYER ALOFT ADVECTS OVER A COLD BOUNDARY LAYER. DIDN`T GO
MOSTLY CLOUDY...BUT DO HAVE AN INCREASE IN CLOUD COVER (PARTLY
CLOUDY) THIS EVENING.
TEMPS...YET ANOTHER ISSUE. HAVE MAINLY CLEAR SKIES INTERIOR GOING
INTO THE EVENING WHICH WILL ALLOW TEMPS TO DROP QUICKLY AGAIN. BUT
TEMP FREE-FALL WILL BE THROTTLED COMPARED TO LAST NIGHT BY STRONGER
FLOW OFF THE SFC. DON`T FORESEE BELOW ZERO READINGS TONIGHT GIVEN THE
STRONGER WINDS AND CLOUD POTENTIAL...BUT SOME OF THE COLDER SPOTS
DIPPING INTO THE SINGLE DIGITS CERTAINLY NOT OUT OF THE
QUESTION.
SUNDAY...ANY CIGS/FOG WILL ERODE DURING THE MORNING HOURS AS WARMER
AIR CONTINUES TO WORK INTO THE REGION. NEXT WEATHER MAKER WILL BE
WORKING INTO THE MIDWEST THROUGH THE COURSE OF THE DAY. STRONG PULSE
OF WARM ADVECTION EXPECTED TO PUSH PRECIP UP THROUGH THE STATE...
GENERALLY BETWEEN THE 21Z AND 00Z TIME FRAME (MODEL CONSENSUS IS
PRETTY CLOSE)...WHICH SEEMS REASONABLE GIVEN THE VERY DRY AIR IN
PLACE DOWNSTAIRS INITIALLY. BUT ONCE AGAIN...WARM NOSE ALOFT
ROCKETING INTO THE REGION WILL ALSO BRING ANOTHER ROUND OF P-TYPE
ISSUES TO NORTHERN MICHIGAN. COLD TEMPS TO START AND SFC TEMPS JUST
INCHING TO AROUND THE FREEZING MARK WILL PRESENT A RAIN/FREEZING
RAIN PROBLEM OVER THE HIGH TERRAIN/NE LOWER MICHIGAN. SNOW/SLEET/
FREEZING RAIN MIX IN EASTERN UPPER WITH SLIGHTLY COLDER AIR ALOFT.
DON`T THINK WE GET WARNING CRITERIA PRECIP OF ANY TYPE. BUT MAY
ULTIMATELY NEED SOME ADVISORIES ISSUED...BUT WILL ALLOW LATER SHIFTS
TO TAKE CARE OF THAT.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 420 PM EST SAT FEB 9 2013
PROGRESSIVE PATTERN SET TO CONTINUE...COURTESY OF ONE AGITATED
PACIFIC PATTERN (WHICH WATER VAPOR IMAGERY SHOWS COVERED WITH A
VIRTUAL WAVE-TRAIN OF STRONG TROUGH/RIDGE COUPLETS) AND LACK OF ANY
DOWNSTREAM NORTH ATLANTIC BLOCKING. THIS AGGRESSIVE FLOW WILL HELP
KICK OUT CURRENT FOUR-CORNERS WAVE...WHICH WILL CUT ACROSS THE
NORTHERN LAKES SUNDAY NIGHT INTO MONDAY...BRINGING A PLETHORA OF
DIFFERENT WEATHER TYPES. PLENTY OF SUPPORT FOR A MUCH TAMER PERIOD
OF WEATHER HEADING THROUGH THE MIDDLE OF NEXT WEEK AS AREA BECOMES
CENTERED BETWEEN ACTIVE STORM TRACKS. FORECAST CONCERNS CONTINUE TO
FOCUS ON WEATHER TYPES AND POTENTIAL IMPACTS FROM SUNDAY NIGHT AND
MONDAYS SYSTEM.
AGGRESSIVE PUSH OF WAA/ISENTROPIC UPGLIDE ON NOSE OF 50+ KNOT LOW
LEVEL JET WILL RACE ACROSS THE AREA SUNDAY EVENING...ACCOMPANIED BY
AN AREA OF MODERATE PRECIP. WAA NOT AS AGGRESSIVE AT THE
SURFACE...ALTHOUGH STOUT OFF THE DECK WARM NOSE ENSURES ANYTHING
REACHING THE SURFACE ACROSS NORTHERN LOWER WILL BE OFF THE LIQUID
VARIETY. SOME LINGERING NEAR FREEZING AREAS/COLD SKIN TEMPERATURES
MAY CONTINUE TO RESULT IN POCKETS OF FREEZING RAIN ACROSS THE
INTERIOR HIGHLANDS DURING THE EARLY EVENING...WITH PLAIN RAIN
FALLING ELSEWHERE. EVAP COOLING ALLOWS COLUMN TEMPERATURES TO
STRADDLE THE FREEZING LINE NORTH OF THE BRIDGE...SUGGESTING
PRIMARILY A SNOW OR SNOW/SLEET MIXTURE AS STEADIEST/HEAVIEST PRECIP
ARRIVES. WHILE SNOW TO LIQUID RATIOS WILL REMAIN LOW...A SEVERAL
HOUR PERIOD OF POTENTIALLY HEAVY SNOWFALL RATES WILL LIKELY PRODUCE
A FEW INCHES (2 TO 5) ACROSS INTERIOR EASTERN UPPER. STRONG
SHORTWAVE AND ATTENDANT SURFACE LOW PIVOT INTO CENTRAL UPPER
MICHIGAN BY MONDAY MORNING...ALLOWING A PRETTY RESPECTABLE MID LEVEL
DRY SLOT TO OVERSPREAD NORTHERN LOWER MICHIGAN. THIS SHOULD BRING
MORE OF A VERY LIGHT RAIN/DRIZZLE SCENARIO OVERNIGHT. MOISTURE
REMAINS DEEPER NORTH OF THE STRAITS ALONG AND NORTH OF SURFACE WARM
FRONT. SNOW/SLEET MIXTURE SHOULD TRANSITION MORE TO A
RAIN/SLEET/FREEZING RAIN/SNOW MIXTURE AS 900MB CENTERED WARM NOSE
INCREASES TO +2C...WITH JUST MINIMAL ADDITIONAL SNOW ACCUMULATIONS
AFTER MIDNIGHT.
SYSTEM CONTINUES TO OCCLUDE/WEAKEN AS IT PUSHES OFF INTO CANADA
LATER MONDAY AND MONDAY NIGHT. DRY SLOT FOLLOWS SUITE...WITH DEEPER
MOISTURE ALONG SECONDARY TROUGH AXIS PUSHING INTO THE REGION THROUGH
THE DAY. BACKSIDE CAA NOT NEARLY AS AGGRESSIVE...SUGGESTING A SLOWER
TRANSITION BACK TO SNOW THAN WHAT IT APPEARED LIKE YESTERDAY. COLD
LAYER DEEPENS ENOUGH TO SUPPORT PRIMARILY SNOW BY LATE
AFTERNOON...WITH SOME MINOR (SUB ONE INCH) ACCUMULATIONS
POSSIBLE...ESPECIALLY WHERE WEST FLOW UPSLOPE IS MAXIMIZED INTO THE
HIGHLANDS. REAL MARGINAL CONDITIONS FOR NW-WNW LAKE ENHANCEMENT
MONDAY NIGHT WITH DELTA T/S FLIRTING WITH 13C AND INVERSION LEVELS
AT H85 LEVEL. PERHAPS AN ADDITIONAL INCH OF SNOW IN FAVORED
AREAS...OTHERWISE JUST SOME SCATTERED LIGHT SNOW SHOWERS AND
FLURRIES.
OTHER THAN SOME LINGERING LIGHT SNOW SHOWERS TUESDAY MORNING...JUST
NOT A WHOLE LOT TOO TALK ABOUT HEADING INTO THURSDAY AS NORTHERN
LAKES BECOMES CENTERED BETWEEN NORTHERN AND SOUTHERN STREAM WAVES.
IMAGINE A FEW FLURRIES/LIGHT SNOW SHOWERS ARE POSSIBLE LATER
WEDNESDAY INTO WEDNESDAY NIGHT AS SOUTHERN PORTION OF NORTHERN WAVE
SWEEPS ACROSS...BUT NOT WORTHY OF A SPECIFIC MENTION IN THIS
FORECAST. POTENTIAL FOR A STRONGER HYBRID CLIPPER TYPE SYSTEM TO
ARRIVE TO END THE EXTENDED...BRINGING ADDITIONAL LIGHT SNOW CHANCES.
TEMPERATURES TO AVERAGE NEAR TO ABOVE NORMAL WEDNESDAY THROUGH
FRIDAY...WITH A SHOT OF COOLER AIR ARRIVING TO START NEXT WEEKEND
(SUBJECT TO MANY CHANGES...OF COURSE).
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1148 PM EST SAT FEB 9 2013
BRIEF PERIOD OF MVFR CEILINGS AT MBL THROUGH 08Z-09Z...OTHERWISE
VFR UNTIL SUNDAY AFTERNOON AS CLOUDS LOWER AND PRECIPITATION MOVES
IN FROM THE SOUTHWEST. COULD START AS A PERIOD OF FREEZING
RAIN/SLEET MAINLY AT APN/PLN.
&&
.MARINE...
ISSUED AT 420 PM EST SAT FEB 9 2013
SOUTHERLY WINDS WILL INCREASE TONIGHT AND FURTHER THROUGH THE DAY SUNDAY
IN ADVANCE OF ANOTHER LOW PRESSURE SYSTEM THAT WILL TRACK THROUGH
THE NRN LAKES LATE SUNDAY INTO MONDAY. AT THIS POINT...WITH WARMING
TEMPS OVER THE LAKES/INCREASING LAKE STABILITY...DON`T THINK WIND
GUSTS WILL REACH GALE FORCE WITH THIS SYSTEM. HOWEVER...A HANDFUL
OF SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR SUNDAY AND
SUNDAY NIGHT.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JPB
SYNOPSIS...NTS
SHORT TERM...TBA
LONG TERM...MSB
MARINE...TBA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1152 PM CST SAT FEB 9 2013
.AVIATION... /06Z TAF ISSUANCE/
THE FIRST BAND OF LIGHT PRECIPITATION IS NEARING KAXN AND KRWF AT TAF
ISSUANCE. MAINLY SNOW IS EXPECTED OVERNIGHT BUT SOME LIGHT FREEZING
RAIN AND SLEET CAN NOT BE RULED OUT. THE TREND WILL BE FOR SEVERAL
BANDS OF LIGHT PRECIPITATION TO MOVE THROUGH OVERNIGHT BEFORE A
MORE PRONOUNCED AREA OF MODERATE TO HEAVY SNOW DEVELOPS IN THE
MORNING AND LASTS THROUGH THE DAY. KSTC WILL ALSO SEE INTERMITTENT
LIGHT SNOW OVERNIGHT ALONG WITH SOME BOUTS OF FREEZING DRIZZLE IN
BETWEEN. BEST CHANCE FOR MODERATE TO HEAVY SNOW AT KSTC IS FROM
LATE MORNING THROUGH THE EARLY AFTERNOON HOURS. KMSP...KRNH AND
KEAU ARE MORE PROBLEMATIC ON PRECIPITATION TYPE AS SOME LOW LEVEL
WARM AIR MAY RESULT IN A MIX OF LIGHT SNOW AND FREEZING RAIN
DURING THE LATE NIGHT AND EARLY MORNING HOURS. CHANCES INCREASE
FOR MODERATE TO HEAVY SNOW AT THESE SITES BETWEEN 15Z AND 21Z. AN
ADDITIONAL THREAT FOR A PERIOD OF HEAVY SNOW EXISTS FOR KEAU
SUNDAY EVENING ASSOCIATED WITH A MID LEVEL LOW MOVING THROUGH.
THERE COULD ALSO BE SOME THUNDER AS WELL. NORTHWEST WINDS WILL BE
ON THE INCREASE FOR KAXN AND KRWF IN THE EVENING WITH SUSTAINED
SPEEDS OF 15 TO 20 KNOTS LIKELY ALONG WITH GUSTS FROM 25 TO 30
KNOTS. HIGHER WINDS AFTER 11/06Z WITH 25G35KTS COMMON ALONG WITH
BLSN.
KMSP...SOME LIGHT PRECIPITATION WILL REACH THE AIRFIELD AFTER 09Z.
TRENDS CONTINUE TO POINT TO A MIX OF SNOW...SLEET AND FREEZING
RAIN IN THE 10Z-14Z TIME FRAME WITH MODERATE TO HEAVY SNOW LIKELY
FROM 15Z-19Z. SNOWFALL RATES DURING THE LATE MORNING AND EARLY
AFTERNOON HOURS COULD BE AROUND 2 INCHES AN HOUR. LIGHTER SNOW
EXPECTED DURING THE LATE AFTERNOON AND EVENING HOURS ALONG WITH
THE WIND BACKING TO THE NORTHWEST LATE IN THE EVENING WITH SPEEDS
OF 15 TO 20 KNOTS LIKELY ALONG WITH GUSTS OVERNIGHT FROM 25 TO 30
KNOTS.
/OUTLOOK FOR KMSP/
MON...IFR EARLY WITH -SN/BLSN...THEN MVFR WITH -SN. NW WINDS
18G30KTS.
TUE...VFR. W WINDS 5-10 KTS.
WED...VFR. W WINDS 5 TO 10 KTS.
&&
.DISCUSSION... /ISSUED 229 PM CST SAT FEB 9 2013/
MAIN CONCERN CONTINUES TO BE THE SIGNIFICANT WINTER STORM EXPECTED
TO IMPACT THE AREA FROM LATE TONIGHT INTO MONDAY. THE LATEST WATER
VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS SHOW THE FEATURE OF
INTEREST MAKING ITS WAY THROUGH THE SOUTHERN ROCKIES AT THE
CURRENT TIME... WITH A NICE RIDGE DEVELOPING AHEAD OF IT ACROSS
THE NORTHERN PLAINS. THE SHORTENING WAVELENGTH BETWEEN THESE
FEATURES WILL BE COINCIDENT WITH THE SYSTEM DEEPENING AND MOVING
NORTHEAST TOWARD OUR AREA... AND WILL MANIFEST ITSELF IN A PERIOD
OF STRONG FORCING LATE TONIGHT THROUGH THE DAY ON SUNDAY. THERE
CONTINUES TO BE SOME UNCERTAINTY IN PRECIPITATION TYPE WITH THIS
SYSTEM... ALTHOUGH THE 12Z GUIDANCE HAS COME INTO GOOD AGREEMENT
ON TRACKING THE SURFACE LOW ACROSS IOWA AND FAR SOUTHEAST
MINNESOTA AND INTO CENTRAL WISCONSIN SUNDAY INTO SUNDAY EVENING.
THE REMAINING DIFFERENCES REVOLVE AROUND HOW THE THERMAL PROFILE
WILL EVOLVE THROUGH THE EVENING... PARTICULARLY FROM THE SURFACE
TO 925MB. THE GFS CONTINUES TO BE WARMEST IN THAT LAYER... WITH
THE ECMWF... NAM... AND GEM SUGGESTING THINGS WILL BE COOLER AND
MOSTLY SNOW ACROSS MOST OF THE AREA. GENERALLY FOLLOWED A BLEND OF
THE ECMWF AND NAM FOR THE FORECAST DETAILS... WITH SOME ADDITIONAL
RELIANCE ON THE HIGH RESOLUTION WINDOW RUNS AND LOCAL 4KM GUIDANCE.
EXPECT PCPN TO OVERSPREAD THE CWFA OVERNIGHT INTO SUNDAY
MORNING... WITH SOME FREEZING RAIN POSSIBLE INITIALLY ACROSS
SOUTHERN AND EASTERN MINNESOTA BEFORE THE ELEVATED WARM LAYER
SATURATES AND COOLS TO BELOW FREEZING WET BULB VALUES. AFTER THAT
POINT... IT LOOKS LIKE THE MAIN CHANCES FOR MIXED PCPN WILL BE
FROM NEAR THE TWIN CITIES SOUTH AND EAST... WHERE THE ELEVATED
WARM LAYER WILL FLIRT WITH 0C AT TIMES AND NEAR SURFACE
TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE FREEZING. THE
WESTERN AND NORTHERN PORTIONS OF THE AREA LOOK TO BE SNOW FOR THE
ENTIRE EVENT... AND WITH THE MAIN MID-LEVEL DEFORMATION ZONE AND
ASSOCIATED FRONTOGENESIS IMPACTED THOSE AREAS... STILL EXPECT THE
BEST SNOW AMOUNTS TO OCCUR OVER THE FAR WEST AND NORTHWEST PART OF
THE AREA. PCPN ACROSS THE CENTRAL AND EASTERN CWFA... INCLUDING
THE TWIN CITIES... WILL BE PRIMARILY FORCED BY THE SURGE OF STRONG
WARM ADVECTION/ISENTROPIC LIFT SUNDAY MORNING... ALONG WITH A
DECENT AREA OF UPPER DIVERGENCE IN THE LEFT EXIT REGION OF THE
APPROACHING JET. THALER QG DIAGNOSTICS ARE VERY CONSISTENT BETWEEN
THE VARIOUS GUIDANCE SOURCES... AND ALL PUSH A STRONG SLUG OF QG-
OMEGA ACROSS THE CWFA DURING THE MORNING AND EARLY AFTERNOON
HOURS. THE MID-LEVEL DRY SLOT ASSOCIATED WITH THE UPPER JET STILL
LOOKS LIKE IT SHOULD IMPACT AT LEAST THE SOUTHEAST THIRD OR SO OF
THE CWFA... LIKELY FROM AROUND THE TWIN CITIES METRO SOUTH/EAST...
DURING THE AFTERNOON HOURS. THAT COULD BRING A PERIOD OF SOME
DRIZZLE OR FREEZING DRIZZLE... BUT AT THIS POINT DIDN/T TRY TO
WORK THAT INTO THE FORECAST GIVEN THE MORE SIGNIFICANT PCPN WHICH
WILL OCCUR PRIOR TO THAT AND SOME SNOW WITH THE UPPER LOW
AFTERWARD. AS THE DRY SLOT PUNCHES IN TOWARD THE AREA WE WILL SEE
CONVECTIVELY INSTABILITY INCREASE DRAMATICALLY JUST AHEAD OF IT AS
THE DRY AIR MOVES IN ABOVE THE MOIST BOUNDARY LAYER AND LOWER
TROPOSPHERE. SHOWALTER INDICES ACTUALLY DIP TO AROUND OR A BIT
BELOW ZERO OVER THE SOUTHEAST PORTION OF THE CWFA DURING THE
AFTERNOON... SO WOULDN/T BE SURPRISED IF SOME THUNDER OCCURRED.
ALSO LEFT THAT OUT OF THE FORECAST FOR NOW... BUT IT IS CERTAINLY
WORTH KEEPING AN EYE ON... SINCE ANY BURST OF CONVECTION WOULD
LIKELY CHANGE ANY LINGERING MIXED PCPN OVER TO SNOW AND COULD
AUGMENT PCPN TOTALS ACROSS THE SOUTHERN AND EASTERN PORTIONS OF
THE WINTER STORM WARNING AREA.
EXPECT TO SEE SOME SNOW PERSIST INTO SUNDAY NIGHT ON THE BACKSIDE
OF THE LOW... WITH SNOW SHOWERS LINGERING INTO MONDAY WITH THE
CYCLONIC FLOW. THE PRESSURE GRADIENT WILL TIGHTEN LATE SUNDAY
NIGHT INTO MONDAY... WITH 925MB WINDS INCREASING TO 30-40 KT
ACROSS MUCH OF THE WESTERN AND SOUTHWESTERN CWFA. KEPT THE
BLIZZARD WATCH GOING TO ACCOUNT FOR THE POSSIBILITY OF BLIZZARD
CONDITIONS FROM THE SNOW SHOWERS AND BLOWING SNOW LATE SUNDAY
NIGHT INTO MONDAY. DIDN/T WANT TO BLANKET THE ENTIRE TIME FRAME
WITH A BLIZZARD WARNING... SINCE MOST OF THE SNOW WILL OCCUR
SUNDAY PRIOR TO WHEN WINDS ARE EXPECTED TO INCREASE. SO... IT
SEEMED THE MOST LOGICAL WAY TO DO THINGS FOR NOW WAS TO GO WITH
THE WINTER STORM WARNING WHILE KEEPING A BLIZZARD WATCH FOR THE
LATER TIME FRAME.
RIDGING SHOULD BRING QUIET WEATHER FOR THE MIDDLE PART OF THE
WEEK... WITH AN ALBERTA CLIPPER DROPPING INTO THE REGION FOR THE
THURSDAY-FRIDAY TIME FRAME. INCLUDED A CHANCE OF SOME SNOW FROM
THURSDAY INTO FRIDAY AS THIS SYSTEM MOVES ACROSS THE REGION. THERE
REMAIN SOME DIFFERENCES BETWEEN THE ECMWF AND GFS... SO DON/T SEE
MUCH REASON TO GO WITH ANYTHING MORE THAN CHANCE POPS AT THIS
POINT. TEMPERATURES THROUGH THE WEEK LOOK SEASONABLE... EXCEPT
BEHIND THE CLIPPER FRIDAY INTO SATURDAY WHEN BELOW NORMAL
TEMPERATURES ARE EXPECTED TO RETURN TO THE AREA.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST MONDAY FOR BLUE EARTH-LE
SUEUR-RICE-SCOTT-WASECA-WATONWAN.
WINTER STORM WARNING UNTIL MIDNIGHT CST SUNDAY NIGHT FOR BROWN-
CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-NICOLLET-POPE-
REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-YELLOW MEDICINE.
BLIZZARD WATCH FROM LATE SUNDAY NIGHT THROUGH MONDAY AFTERNOON
FOR BROWN-CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-NICOLLET-
POPE-REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-YELLOW MEDICINE.
WINTER STORM WARNING UNTIL 6 PM CST MONDAY FOR CARVER-MCLEOD-
MEEKER-STEARNS-TODD-WRIGHT.
WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR ANOKA-BENTON-
CHISAGO-HENNEPIN-ISANTI-KANABEC-MILLE LACS-MORRISON-RAMSEY-
SHERBURNE-WASHINGTON.
WINTER WEATHER ADVISORY UNTIL 3 PM CST SUNDAY FOR FARIBAULT-
FREEBORN-MARTIN-STEELE.
WINTER WEATHER ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY
NIGHT FOR GOODHUE.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST SUNDAY NIGHT FOR
DAKOTA.
WI...WINTER WEATHER ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY
NIGHT FOR CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE.
WINTER STORM WARNING FROM 6 AM SUNDAY TO 6 AM CST MONDAY FOR
BARRON-POLK-RUSK-ST. CROIX.
&&
$$
RAH/TRH
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
449 AM EST SUN FEB 10 2013
.SYNOPSIS...
SUNNY AND MILDER WEATHER IS EXPECTED TODAY AS HIGH PRESSURE MOVES
OFF THE EAST COAST AND A SOUTHERLY FLOW OF AIR DEVELOPS. A LOW
PRESSURE SYSTEM WILL BRING A LIGHT WINTRY MIX INCLUDING FREEZING
RAIN LATE TONIGHT INTO MONDAY MORNING...WITH A TRANSITION TO PLAIN
RAIN MONDAY. AFTER THIS LOW PRESSURE SYSTEM PASSES BY TO THE
NORTHEAST MONDAY NIGHT, IT WILL SWING A COLD FRONT THROUGH THE
AREA WITH A RETURN TO COLDER TEMPERATURES. THIS WILL LEAD TO SNOW
SHOWERS AND FLURRIES DOWNWIND OF LAKE ONTARIO AND LAKE ERIE UNTIL
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
400 AM UPDATE...MADE MINOR TWEEKS MAINLY TO CLD COVER AND TEMPS
ERLY THIS MORNING AS LOW CLDS STUBBORNLY HANG ON DOWNWIND OF LAKE
ONTARIO. I SUSPECT THESE CLDS WILL DISSIPATE AFTER SUNRISE. ALSO
HAVE A FEW FLURRIES FROM THESE CLOUDS AS SURFACE TEMPS ARE CLOSE
TO THE MAX ICE CRYSTAL GROWTH RATE...SUGGESTING ANY OROGRAPHIC
LIFTING CAN EASILY SQUEEZE OUT A FLURRY OR TWO.
PREVIOUS DISCUSSION BELOW FROM 1 AM UPDATE...
IR IMAGERY AND GOES 11-3.9 MIRCON IMAGERY SHOWS PESKY LOW LAKE
EFFECT CLOUDS HANGING ON UNDER A SHARP VERY LOW-LEVEL INVERSION
WITHIN A SHALLOW NORTHWEST FLOW IN EC NY. KBGM 88D VWP SHOWS A
340-350 DEGREE WIND AT 10 KTS ABT 500 FEET AGL AND ALMOST LIGHT
AND VARIABLE ABOVE THIS. THIS LOW CLOUD LAYER THAT WAS MAINLY
DOWNWIND OF THE FINGER LAKES AND LAKE ONTARIO WAS SHRINKING AND
WILL CONTINUE TO DO SO AS THE LATEST RAP 925 MB LAYER WINDS
BETWEEEN 6 AND 9Z TURN MORE NORTH TO NORTHEAST AND WEAKEN...LOSING
THE OVERLAKE TRAJECTORIES. IN ADDITION OUR LOCAL WRF MODEL WITH
ITS HOURLY OUTPUT ALSO IS VERY SIMILAR AND DIMINISHES THE LOW CLD
COVER IN A SIMILAR FASHION AS PER THE DRYING OF THE 925 MB LAYER
AS THE 925 MB WINDS SHIFT MORE NRLY AND LOSE LAKE TRAJECTORIES.
HENCE HAVE CLOUDS DIMINISHING FOR THE REMAINDER OF THE EARLY
MORNING HOURS. MINS WILL BE TRICKY GIVING THE WIDE RANGE OF
TEMPERATURES OBSERVED AT PRESENT DUE TO CLD CVR. IN CLD CVR AREAS
TEMPS ARE IN THE TEENS WITH TEMPERATURES RAPIDLY DROPPING TO NEAR
ZERO IN CLR SKY AREAS. I HAVE MINS RANGING FROM SUB ZERO SINGLE
DIGITS MAINLY TO SINGLE DIGITS WHERE CLD CLEAR LATEST IN EC NY.
FOR SUNDAY...SFC HIGH PRESSURE RDG AXIS IS OVHD AT 12Z AND RAPIDLY
SHIFTS EAST DURING THE DAY...REACHING OFFSHORE BY EVENING.
MEANWHILE NEXT STORM WAS BEGINNING TO WORK EASTWARD. THE 850 AND
925 MB WAA BEGINS DURING THE DAY AS SOUTHERLY WINDS
INCREASE...THIS WILL ALSO POP UP AN UPPER LEVEL RDG OVHD DURING
THE DAY SUNDAY. SOME HIGHER CLDS WILL ADVECT IN OVER THE UPR RDG...
BUT THE DEEPER MID LAYER CLDS HOLD OFF MOST OF THE DAY REACHING
WRN NY LATE. I SEE MAINLY CIRRUS OVERSPREADING C NY AND NE PA DURING
AFTERNOON WITH A MILDER DAY IN STORE DUE TO LL WARM ADVECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
ALL 00Z MODELS...INCLUDING THE NAM12...GFS40...CMC AND EURO ALL
TRACK THE NEXT SIGNIFICANT CYCLONE TRACKING INTO WI BY 6Z MONDAY.
AT UPPER LEVELS THERE WAS A LOW OVER THE WESTERN LAKES REGION
WITH A PERSISTENT UPPER LVL RDG OFF THE SE COAST TO THE WRN GULF
COAST. AS A RESULT OF THIS UPPER LEVEL GEOPOTENTIAL FIELD...THERE
WAS A STRONG UPPER LEVEL JET STREAK THAT WILL PUNCH INTO THE OHIO
VALLEY BETWEEN 6Z AND 18Z MONDAY. THIS WILL INDUCED A STRONG
SOUTHERLY LOW-LEVEL JET ARND 850 MB UP INTO NY AND PA TONIGHT/ERLY MON.
THIS LLJ WILL FEATURE STRONG MOISTURE ADVECTION AND RISE
ISENTROPICALLY. ALL MODELS AGREE THAT PRECIP SPREADS FROM WEST TO
EAST ACROSS CENTRAL NY AND NE PA BTWN 6Z AND 12Z MONDAY. WILL RAMP
POPS UP TO CATEGORICAL BY 12Z ALL FORECAST AREA.
NOW TO P-TYPE. INITIALLY TEMPERATURES AND DEWPOINTS MOST OF CWA
WILL BE BELOW FREEZING WITH SUB FREEZING DWPTS AS WELL LATE TONIGHT.
MODEL GUIDC SUGGESTS OUR DOWNSLOPE REGIONS IN THE NRN FINGER LAKES
ACTUALLY REMAIN ABV FREEZING WHICH IS NOT UNUSUAL TONIGHT. SO I WUD
EXPECT STEADY AND SLOWING RISING TEMPERATURES SUNDAY NIGHT REST OF
ZFORECAST AREA. WHEN PRECIP ARRIVES IT WILL BE MAINLY ZR INITIALLY
WITH POSSIBLY SOME IP...BUT WITH 850 MB TEMPS ABV FREEZING DON/T
SEE SNOW. PRECIPITATION WILL RAPIDLY TURN OVER TO PLAIN RAIN
MONDAY DURING THE MORNING MOST OF CWA AS TEMPS WARM ABV FREEZING.
THE LAST HOLD OUTS WILL BE IN THE FAR EASTERN PART OF THE CWA FROM
SULLIVAN CO TO THE UPPER MOHAWK VALLEY WHERE ZR WILL LAST UNTIL
AFTERNOON. ICE AMNTS WILL BE LIGHT...GENERALLY UNDER
.1 INCHES...HOWEVER I SEE SOME AREAS IN THE CATSKILLS TO MOHAWK
VALLEY SEEING MAYBE UP TO .15 INCH. MAIN IMPACT WILL BE TO TRAVEL.
FOR NOW HELD OFF ON ISSUING ANY FLAGS FOR FREEZING RAIN AS NOT SURE
AS TO THE EXTENT OR AREAL COVERAGE OF THE ICING. THERE IS PLENTY
OF TIME AT THIS POINT IN OUR FORECAST AREA SO WILL LET DAY SHIFT
HANDLE. I SUSPECT AN ADVY WILL BE ISSUED FOR A LARGE PART OF THE
FORECAST AREA THIS AFTERNOON FOR LATE TONIGHT/MONDAY MORNING.
THEN BY AFTERNOON MONDAY...RAIN SHEILD ASSOCIATED WITH WARM/MOIST
CONVEYOR BELT IS EAST OF REGION AND THE COLD FRONT WILL SWING THRU
BETWEEN 21Z MON AND 02Z TUE. THIS FEATURE WILL BE ACCOMPANIED BY
CAA AND MAINLY SNOW SHOWERS WHICH WILL MIX WITH RAIN SHOWERS
INITIALLY.
FOR MONDAY NIGHT INTO EARLY TUESDAY...THE LL FLOW IS MORE W-SW
WHICH SHUD DIRECTLY ANY LAKE MOISTURE AND DEVELOPING LES MAINLY N
OF THE BGM FORECAST AREA. H85 TEMPS AT THIS POINT WILL BE MARGINAL
AT BEST SO DOESN/T LOOK LIKE MUCH BEFORE TUE AM IN C NY OR NE PA
OTHER THAN A FEW SNOW SHOWERS OR FLURRIES.
THEN TUE INTO TUE NGT...ANOTHER WAVE AND ASSOCIATED COLD FRONT AND
SURGE OF COLDER AIR PRESSES SOUTH TWD NY AND TURNS THE LL FLOW
MORE W-NW WHICH COMBINED WITH H85 TEMPS DROPPING TO -12C SHUD TRIGGER
SOME LAKE RESPONSE. FOR NOW HAVE POPS IN FOR LES NC NY LATER TUE
INTO TUE NGT. THE NAM HOLDS ONTO THE LES LONGER THRU TUE NGT...GFS
BACKS FLOW QUICKER TUE NGT. NOT SURE EXACTLY ON TIMING THIS FAR
OUT SO PRETTY MUCH WENT WITH SCENARIO THAT KEEPS THE LES IN
LONGER NC NY. NOT LOOKING FOR A MAJOR EVENT. GFS AND NAM SOUNDINGS
FOR SYR SHOW INVERSION BARELY AT 850 MB AND MAX LIFT BELOW THE MAX
GROWTH RATE FOR ICE CRYSTALS. I CUD SEE A FEW INCHES BUT NO
WARNING AMNTS FOR LAKE SNOW BELTS IN NC NY...SO NO LES WATCH. REST OF
FORECAST AREA WILL SEE TYPICAL BKN SC LAYER WITH SCATTERED
FLURRIES OR EVEN SNOW SHOWERS WITH THE DAY/S HEATING. NO ACCUMS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
NOT A DEAD QUIET PATTERN...BUT NOTHING BIG GOING ON EITHER...AT
LEAST NOT YET. THIS PERIOD WILL FEATURE A SPLIT FLOW PATTERN WITH
ALTERNATING WEAK NORTHERN STREAM AND SOUTHERN STREAM WAVES JUST
BARELY SKIMMING BY THE AREA. TEMPERATURES WILL BE NEAR OR JUST A
TOUCH ABOVE CLIMATOLOGY. I WAS COMFORTABLE FOLLOWING HPC GUIDANCE
INCLUDING JUST SLIGHT TO LOW CHANCE POPS...AND MAINLY SNOW SHOWERS
AS PRECIP TYPE...THOUGH PERHAPS MIXED WITH RAIN BY FRIDAY AS FLOW
BECOMES MORE SOUTHWESTERLY. MORE AMPLIFICATION TO THE FLOW OCCURS
HEADING INTO THE WEEKEND...SO WE WILL HAVE TO SEE IF MORE
SIGNIFICANT WAVES WILL BE ABLE TO IMPACT OUR WEATHER BY THEN.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
SOME SHALLOW LL MOISTURE CONTS TO DRIFT OFF THE LAKES AND BRING
MVFR/IFR CONDS TO ITH AND BGM. XPCT THIS TO SLOWLY ERODE OVRNGT AS
THE WIND FLOW BECOMES LESS FVRBL. OTRW...XPCT VFR CONDS THRU THE
PD AS HIGH PRES BLDS INTO THE AREA. LGT WINDS TODAY WILL BECOME SE
AFT 00Z AS A WRM FNT APRCHS AHD OF A LOW MVG INTO THE LAKES. ANY
PCPN WILL BEGIN AFT THE END OF THE TAF PD.
.OUTLOOK...
SUN NGT/MON...MVFR/IFR IN LIGHT WINTRY MIX LATE SUN NIGHT INTO MON
MORNING /INCLUDING FREEZING RAIN/...CHANGING TO ALL RAIN MON.
MON NGT/TUE/TUE NGT...SCT MVFR CNTRL NY IN -SHSN...VFR ELSEWHERE.
WED/THU...VFR MUCH OF THE TIME...BUT MVFR -SN POSSIBLE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...MDP
AVIATION...DGM/DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
133 AM EST SUN FEB 10 2013
.SYNOPSIS...
SUNNY AND MILDER WEATHER IS EXPECTED TODAY AS HIGH PRESSURE MOVES
OFF THE EAST COAST AND A SOUTHERLY FLOW OF AIR DEVELOPS. A LOW
PRESSURE SYSTEM WILL BRING A LIGHT WINTRY MIX INCLUDING FREEZING
RAIN LATE TONIGHT INTO MONDAY MORNING...WITH A TRANSITION TO PLAIN
RAIN MONDAY. AFTER THIS LOW PRESSURE SYSTEM PASSES BY TO THE
NORTHEAST MONDAY NIGHT, IT WILL SWING A COLD FRONT THROUGH THE
AREA WITH A RETURN TO COLDER TEMPERATURES. THIS WILL LEAD TO SNOW
SHOWERS AND FLURRIES DOWNWIND OF LAKE ONTARIO AND LAKE ERIE UNTIL
WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
IR IMAGERY AND GOES 11-3.9 MIRCON IMAGERY SHOWS PESKY LOW LAKE
EFFECT CLOUDS HANGING ON UNDER A SHARP VERY LOW-LEVEL INVERSION
WITHIN A SHALLOW NORTHWEST FLOW IN EC NY. KBGM 88D VWP SHOWS A
340-350 DEGREE WIND AT 10 KTS ABT 500 FEET AGL AND ALMOST LIGHT
AND VARIABLE ABOVE THIS. THIS LOW CLOUD LAYER THAT WAS MAINLY
DOWNWIND OF THE FINGER LAKES AND LAKE ONTARIO WAS SHRINKING AND
WILL CONTINUE TO DO SO AS THE LATEST RAP 925 MB LAYER WINDS
BETWEEEN 6 AND 9Z TURN MORE NORTH TO NORTHEAST AND WEAKEN...LOSING
THE OVERLAKE TRAJECTORIES. IN ADDITION OUR LOCAL WRF MODEL WITH
ITS HOURLY OUTPUT ALSO IS VERY SIMILAR AND DIMINISHES THE LOW CLD
COVER IN A SIMILAR FASHION AS PER THE DRYING OF THE 925 MB LAYER
AS THE 925 MB WINDS SHIFT MORE NRLY AND LOSE LAKE TRAJECTORIES.
HENCE HAVE CLOUDS DIMINISHING FOR THE REMAINDER OF THE EARLY
MORNING HOURS. MINS WILL BE TRICKY GIVING THE WIDE RANGE OF
TEMPERATURES OBSERVED AT PRESENT DUE TO CLD CVR. IN CLD CVR AREAS
TEMPS ARE IN THE TEENS WITH TEMPERATURES RAPIDLY DROPPING TO NEAR
ZERO IN CLR SKY AREAS. I HAVE MINS RANGING FROM SUB ZERO SINGLE
DIGITS MAINLY TO SINGLE DIGITS WHERE CLD CLEAR LATEST IN EC NY.
FOR SUNDAY...SFC HIGH PRESSURE RDG AXIS IS OVHD AT 12Z AND RAPIDLY
SHIFTS EAST DURING THE DAY...REACHING OFFSHORE BY EVENING.
MEANWHILE NEXT STORM WAS BEGINNING TO WORK EASTWARD. THE 850 AND
925 MB WAA BEGINS DURING THE DAY AS SOUTHERLY WINDS
INCREASE...THIS WILL ALSO POP UP AN UPPER LEVEL RDG OVHD DURING
THE DAY SUNDAY. SOME HIGHER CLDS WILL ADVECT IN OVER THE UPR RDG...
BUT THE DEEPER MID LAYER CLDS HOLD OFF MOST OF THE DAY REACHING
WRN NY LATE. I SEE MAINLY CIRRUS OVERSPREADING C NY AND NE PA DURING
AFTERNOON WITH A MILDER DAY IN STORE DUE TO LL WARM ADVECTION.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
3 PM UPDATE...
MIDWEST STORM CENTER LIFTS NE INTO ONTARIO BUT AN OCCLUDED FRONT
MOVES THROUGH MONDAY NIGHT WITH MIXED PRECIP. WITH HIGH CLOUDS
SUNDAY EVE AND DRY AIR AT THE SFC TEMPERATURES WILL BE ABLE TO
DROP BELOW FREEZING. 20S MOST AREAS AND TEENS IN THE FAR EAST.
CLOUDS THICKEN AND LOWER WITH LIGHT PRECIP COMING IN AFTER
MIDNIGHT...AND BEFORE SUNRISE. TOTAL AMOUNTS A QUARTER TO HALF AN
INCH MOSTLY MONDAY AM. THE FRONT MAKES STEADY PROGRESS SO MIXED
PRECIP WILL CHANGE TO RAIN BY NOON EXCEPT IN THE FAR EAST WHERE
SOME SLEET COULD BE HAPPENING AT THE HIGHEST ELEVATIONS OF THE SRN
TUG AND CATSKILLS. WITH FREEZING RAIN BEING SHORT LIVED AMOUNTS
WILL BE LESS THAN A TENTH OF AN INCH. THE FINGER LAKES MAY GET
NOTHING WITH TEMPERATURES RISING ABOVE FREEZING THE FASTEST AND
EARLIEST. CONTINUE TO HIGHLIGHT THE FREEZING RAIN THREAT IN THE
HWO.
MONDAY NIGHT TO TUESDAY IN A BROAD TROF AS THE STACKED LOW PASSES
WELL TO THE NORTH OF THE CWA IN SE CANADA. MULTIPLE SHORT WAVES
AND A COLD FRONT WILL MOVE THROUGH MONDAY NIGHT BRINGING SOME
LIGHT SNOW TO MAINLY CENTRAL NY. LESSER AMOUNTS WILL BE IN NE PA.
TUESDAY MORE SNOW SHOWERS ENHANCED WITH LAKE MOISTURE. 850MB TEMPS
FALL TO -12 WHICH IS NOT COLD ENOUGH FOR PURE LAKE EFFECT WITH
LAKE TEMPS IN THE 30S. MORE SHORT WAVES AND A WEAK SFC TROF WILL
PROVIDE LIFT. LOW LEVEL FLOW FROM THE WEST SO MOST OF THE SNOW
SHOWERS WILL BE CONFINED TO UPSTATE NY. ON THE EDGE OF THE
SYNOPTIC MOISTURE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
NOT A DEAD QUIET PATTERN...BUT NOTHING BIG GOING ON EITHER...AT
LEAST NOT YET. THIS PERIOD WILL FEATURE A SPLIT FLOW PATTERN WITH
ALTERNATING WEAK NORTHERN STREAM AND SOUTHERN STREAM WAVES JUST
BARELY SKIMMING BY THE AREA. TEMPERATURES WILL BE NEAR OR JUST A
TOUCH ABOVE CLIMATOLOGY. I WAS COMFORTABLE FOLLOWING HPC GUIDANCE
INCLUDING JUST SLIGHT TO LOW CHANCE POPS...AND MAINLY SNOW SHOWERS
AS PRECIP TYPE...THOUGH PERHAPS MIXED WITH RAIN BY FRIDAY AS FLOW
BECOMES MORE SOUTHWESTERLY. MORE AMPLIFICATION TO THE FLOW OCCURS
HEADING INTO THE WEEKEND...SO WE WILL HAVE TO SEE IF MORE
SIGNIFICANT WAVES WILL BE ABLE TO IMPACT OUR WEATHER BY THEN.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SOME SHALLOW LL MOISTURE CONTS TO DRIFT OFF THE LAKES AND BRING
MVFR/IFR CONDS TO ITH AND BGM. XPCT THIS TO SLOWLY ERODE OVRNGT AS
THE WIND FLOW BECOMES LESS FVRBL. OTRW...XPCT VFR CONDS THRU THE
PD AS HIGH PRES BLDS INTO THE AREA. LGT WINDS TODAY WILL BECOME SE
AFT 00Z AS A WRM FNT APRCHS AHD OF A LOW MVG INTO THE LAKES. ANY
PCPN WILL BEGIN AFT THE END OF THE TAF PD.
.OUTLOOK...
SUN NGT/MON...MVFR/IFR IN LIGHT WINTRY MIX LATE SUN NIGHT INTO MON
MORNING /INCLUDING FREEZING RAIN/...CHANGING TO ALL RAIN MON.
MON NGT/TUE/TUE NGT...SCT MVFR CNTRL NY IN -SHSN...VFR ELSEWHERE.
WED/THU...VFR MUCH OF THE TIME...BUT MVFR -SN POSSIBLE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...TAC
LONG TERM...MDP
AVIATION...DGM/DJP
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
426 AM EST SUN FEB 10 2013
.SYNOPSIS...
SOUTHERLY FLOW INCREASES TODAY. PSEUDO WARM FRONT LIFTING NORTH THRU
TENNESSEE VALLEY. COLD FRONT PASSES MONDAY. HIGH PRESSURE TUESDAY.
LOW PRESSURE PASSES TO THE SOUTH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
WIDE RANGE OF TEMPERATURES OVERNIGHT...FROM NEAR 10 DEGREES IN THE
COLDEST MOUNTAIN VALLEYS OF WEST VIRGINIA...TO NEAR 30 ALONG EXPOSED
MOUNTAIN RIDGES.
FIGURING ON HIGH AND MID CLOUDS THICKENING THIS MORNING...WITH SOME
RADAR RETURNS FROM IT...THEN THIN OUT A BIT FOR A PERIOD THIS
AFTERNOON....BEFORE THE DEEPER MOISTURE KNOCKS ON THE DOOR IN OUR
WESTERN COUNTIES BY DARK.
925 MB FLOW INCREASES AT 25 TO 30 KNOTS FROM THE SSE BY 21Z. WILL
INCREASE GUSTS OVER THE MOUNTAIN COUNTIES...INCLUDING SW VIRGINIA
THIS AFTERNOON.
WITH THE FLOW REMAINING MOSTLY SSE THIS EVENING...NOT SE...THINKING
TEMPERATURES IN OUR COLDEST SPOTS IN THE UPPER GREENBRIER VALLEY
WILL DROP TO AROUND 33 OR 34 DEGREES AFTER THE ONSET OF THE RAIN.
SO NOT THINKING READINGS WILL DROP BELOW FREEZING. WILL INSERT A
SLIGHT CHANCE OF SOME POCKETS OF FREEZING RAIN FOR ABOUT 4 HOURS
CENTERED ON MIDNIGHT FOR THOSE LOCATIONS...INCLUDING PORTIONS OF
POCAHONTAS AND EASTERN RANDOLPH COUNTIES. HAVE TEMPERATURES RISING
DURING THE PREDAWN AS WINDS VEER TO SW THERE.
NO BIG CHANGES ON POPS...WITH HOURLY POPS DECREASING QUICKLY BEFORE
12Z IN THE WESTERN LOWLANDS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AREA GETS INTO INCREASINGLY ALIGNED WSW FLOW AS UPPER LEVEL LOW
TRAVERSES GREAT LAKES MON. DEEP LAYER MOISTURE EXITS FIRST THING IN
THE MORNING...AS UPPER LEVEL JET MAX PASSES. THIS WILL LEAD TO
INCREASINGLY MIXED AIR MASS THAT MAY BECOME DRY ADIABATIC ALL THE
WAY TO H7. HAVE WINDS REACHING CRITERIA FOR ADV ONLY FOR HIGHEST
ELEVATIONS SO FAR VIA RUC MOMENTUM MIXING ALGORITHM.
HIGH PRESSURE SLOWLY BUILDS IN ON TUE...ONLY TO RETREAT TUE NT AS
NEXT S/W TROF APPROACHES FROM THE W. ASSOCIATED CONFLUENCE ZONE
SETS UP ACROSS NRN PA AS SFC LOW TRACKS TO THE S...THE GFS/ECMWF
SOLN FAVORED OVER THE NAM12...WHICH IS THE ODD MODEL N. CANADIAN IS
EVEN FURTHER S. HAVE LIMITED LIKELY POPS TO FAR S PORTION OF THE
AREA.
WHILE THIS IS A SYNOPTICALLY CORRECT TRACK FOR SNOW...BORING
PACIFIC AIR MASS IN PLACE AHEAD OF THE SYSTEM LEAVES TEMPERATURES
ONLY MARGINALLY LOW ENOUGH...ESPECIALLY AT THE SFC...GIVING RISE TO
MIXED PRECIPITATION AND EVEN JUST RAIN. HAVE MINIMAL SNOW AMOUNTS
OF JUST OVER AN INCH ON THE CENTRAL MOUNTAINS AS SYSTEM EXITS WED
AFTERNOON...AND VERY LITTLE ICE. TOGETHER WITH POPS MAINLY IN THE
CHANCE RANGE...HAVE NO HWO MENTION WARRANTED AT THIS POINT AS
CONFIDENCE IN CODABLE WINTER EVENT IS QUITE LOW.
BLENDED IN ADJMET FOR TEMPERATURES EARLY ON...THEN ADJMAV / ADJMEX
TOWARD THE END IN LIGHT OF GFS SOLN. THIS KEEPS FCST LARGELY IN
LINE WITH PREVIOUS PACKAGE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
MDL TRENDS CONT TO CLOSE IN ON OP GFS SOLUTIONS AT LEAST REGARDING
S/W TROF ON WED. 12Z ECWMF CONT THE TREND AS WELL. STILL SOME
UNCERTAINTIES WITH SFC LOW TRACK...BUT ALL AGREE AT LEAST SOME
INFLUENCE FROM INVERTED SFC TROUBLE. ELECTED TO RAISE POPS INTO LKLY
ACROSS SW VA AND IN THE WV MTNS...WITH HIGH CHC ACROSS THE LOWLANDS.
APPEARS LLVL TEMPS WILL BE WARM ENOUGH FOR PERHAPS MAINLY RA BLO
2KFT. SYS PULLS OUT QUICKLY WED EVE FOR A RETURN TO DRY WX THU AND
MOST OF FRI.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
SOME LOCAL VSBY 5 TO 6 MILES IN HAZE AND SMOKE IN WV VALLEYS UNDER
TEMPERATURE INVERSION OVERNIGHT.
HIGH AND MID CLOUDS AOA 10 THSD FT THROUGH ABOUT 22Z BEFORE
THICKENING AND LOWERING.
CEILINGS BECOMING 4 TO 8 THSD FT 23Z SUNDAY TO 03Z MONDAY WITH LIGHT
RAIN LIMITING VSBY 3 TO 5 MILES. CEILINGS BECOMING 2 TO 4 THSD FT BY
06Z MONDAY IN WIDESPREAD RAIN. A SLIGHT CHANCE OF A POCKET OF
FREEZING RAIN IN POCAHONTAS COUNTY AROUND 06Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING OF ARRIVAL OF THE RAIN MAY VARY
BY A COUPLE OF HOURS SUNDAY EVENING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SUN 02/10/13
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z MONDAY...
IFR POSSIBLE IN RAIN LATE SUNDAY NIGHT. IFR POSSIBLE AGAIN
WEDNESDAY AND WEDNESDAY NIGHT IN LIGHT RAIN OR SNOW...MAINLY
MOUNTAIN COUNTIES.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/TRM
NEAR TERM...KTB
SHORT TERM...TRM
LONG TERM...30
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1140 PM CST SAT FEB 9 2013
.AVIATION...
BREEZY WEST WINDS WILL CONTINUE OVERNIGHT. THE WINDS WILL INCREASE
SUNDAY MORNING AS STRONGER WINDS ALOFT MIX DOWNWARD. SOME LIGHT
BLOWING DUST IS EXPECTED AGAIN AT KLBB...BUT VSBYS SHOULD REMAIN
ABOVE MVFR. THE WINDS WILL BEGIN TO DECREASE LATE SUNDAY AFTERNOON
AS THE GRADIENT RELAXES. A FRONT WILL APPROACH KCDS AFTER 0Z.
&&
.PREV DISCUSSION... /ISSUED 1001 PM CST SAT FEB 9 2013/
UPDATE...
HAVE DONE A QUICK UPDATE TO CLEAN UP THE GRIDS AND TRIM BACK POPS.
SEVERE CONVECTION HAS QUICKLY COME TO AN END...THOUGH WE COULD
STILL SEE A FEW SHOWERS OR STORMS YET OVER THE NEXT HOUR OR TWO
ACROSS THE FAR EASTERN ZONES BEFORE THE PACIFIC FRONT CLEARS THE
AREA. OTHERWISE...DRY AND BREEZY CONDITIONS WILL BE THE RULE
BEHIND THE FRONT OVERNIGHT.
PREV DISCUSSION... /ISSUED 821 PM CST SAT FEB 9 2013/
UPDATE...
WE HAVE ALLOWED THE WIND ADVISORY AND WARNING TO EXPIRE ON
SCHEDULE AT 8 PM. WINDS...IN GENERAL...ARE COMING DOWN...THOUGH A
FEW SPOTS IMMEDIATELY BEHIND THE ADVANCING PACIFIC FRONT MAY
BRIEFLY TOUCH ADVISORY LEVELS. OTHER CONCERN WILL CONTINUE TO
REVOLVE AROUND DEVELOPING CONVECTION THAT IS FORMING ACROSS THE
NORTHEAST ZONES CURRENTLY. THIS CONVECTION IS OCCURRING IN A
WEAKLY UNSTABLE AIRMASS...BUT IS SUPPORTED BY INCREASING LARGE
SCALE ASCENT AND INCREASED LOW-LEVEL FORCING AS A PACIFIC FRONT
IS IMPINGING ON THE IMPROVED LOW-LEVEL MOISTURE RESIDING ACROSS
ROUGHLY THE EASTERN HALF OF THE CWA. COULD YET SEE A FEW
STRONG/SEVERE STORMS...LIKELY FAVORING THE NORTHEAST ZONES. IT
BECOMES MORE UNCERTAIN HOW FAR SOUTH THE CONVECTION CAN DEVELOP
INTO THE ROLLING PLAINS AS LOW-LEVEL CONVERGENCE IS PROGGED TO
WEAKEN WITH SOUTHERN EXTENT AND CIN INCREASE.
REGARDLESS...CONVECTION WILL QUICKLY SHIFT EAST...AND LIKELY BE
OUT OF THE CWA BY MIDNIGHT.
PREV DISCUSSION... /ISSUED 540 PM CST SAT FEB 9 2013/
AVIATION...
GUSTY STRONG WINDS WILL BE THE MAIN CONCERN AT BOTH TERMINALS
THROUGH 1 OR 2Z...AFTER WHICH THE WINDS SHOULD DECREASE TO LESS
THAN ABOUT 18 KTS SUSTAINED. SOME LIGHT BLOWING DUST IS EXPECTED AT
KLBB THROUGH 1Z. ALSO...THERE IS A CHANCE OF TSRA IN THE VICINITY
OF KCDS THROUGH ABOUT 4Z. A FRONT WILL MOVE EAST ACROSS THE AREA
BEFORE MIDNIGHT BRINGING A WIND SHIFT FROM SW TO WEST BUT WITH NOT
MUCH CHANGE IN WIND SPEED GIVEN THE TIME OF DAY. SUNDAY
MORNING...THE WINDS WILL RAMP UP AGAIN AS STRONG W-NW WINDS ALOFT
MIX DOWN. SOME LIGHT BLOWING DUST WILL BE POSSIBLE AT LUBBOCK
AGAIN BY MIDDAY. THE WINDS WILL START TO DIMINISH SUNDAY
AFTERNOON.
PREV DISCUSSION... /ISSUED 304 PM CST SAT FEB 9 2013/
SHORT TERM...
A BUSY AFTERNOON IS IN STORE FOR THE CWA... WITH BOTH HIGH WINDS IN THE
WEST AND THE POSSIBILITY FOR STORMS IN THE EAST. AS EXPECTED... A
POTENT TROUGH IS CURRENTLY ADVANCING ON WEST TEXAS... WITH A 500MB
KT MAX OF OVER 100KT CURRENTLY SITUATED OVER EASTERN NEW MEXICO.
HIGH CLOUDS HAVE CLEARED OVER MOST OF THE NW PORTION OF THE CWA AND
NEW MEXICO...ALLOWING FOR DEEP MIXING AND VERY STRONG WINDS ACROSS
MOST OF EASTERN NEW MEXICO. WINDS HAVE BEEN SLOW TO VEER IN WEST
TEXAS THIS AFTERNOON...ALLOWING DEWPOINTS TO CLIMB INTO THE UPPER
30S AND NEAR 40 ACROSS MOST OF THE CAPROCK AS OF 18Z. HOWEVER...
SURFACE OBS AND RADAR TRENDS ARE INDICATING THAT WINDS ARE FINALLY
BEGINNING TO VEER SLIGHTLY IN THE WEST... WHICH HAS RESULTED IN
RAPID DRYING AND INCREASING WIND SPEEDS JUST EAST OF THE TEXAS NEW
MEXICO BORDER. GIVEN THESE TRENDS... HAVE OPTED TO UPGRADE
PARMER...CASTRO AND BAILEY COUNTIES TO A HIGH WIND WARNING THROUGH
02Z. FIRE WEATHER CONCERNS ARE STILL MINIMAL... ESPECIALLY GIVEN
THE HIGHER THAN ANTICIPATED DEWPOINTS ACROSS THE WEST AND MOIST FUEL
CONDITIONS... HOWEVER ELEVATED FIRE WEATHER CONDITIONS AND SOME
RED FLAG MINUTES WILL BE PRESENT NEAR THE TX/NM BORDER THROUGH
THE EARLY EVENING WHERE THE AIR WILL BE DRIEST AND WINDS
STRONGEST.
FURTHER EAST... THE FORECAST STILL APPEARS TO BE LARGELY ON TRACK AS
MOISTURE CONTINUES TO RETURN ACROSS THE EAST. RADAR AND SURFACES
OBSERVATIONS INDICATE THE BEGINNINGS OF A DRYLINE FORMING JUST TO
THE EAST OF THE TX/NM STATE LINE...AND APPEARS TO BE SLOWLY
ADVANCING EAST. IN ADDITION... VISIBLE SATELLITE IMAGERY IS SHOWING
AN INCREASE IN CUMULIFORM CLOUDS JUST TO THE DRY SIDE OF THIS
DEVELOPING DRYLINE. DEWPOINTS AS OF 20Z HAVE REACHED THE UPPER 40S
ACROSS THE SOUTHEAST...TO NEAR 40 IN THE NORTHERN ROLLING
PLAINS...WHICH IS A BIT LOWER THAN YOU WOULD LIKE FOR STORM
DEVELOPMENT. AS SUCH... INSTABILITY IS STILL VERY WEAK ACROSS THE
AREA...WITH MAXIMUM VALUES OF NEAR 500 J/KG RESTRICTED TO THE
SOUTHEAST. THERE STILL REMAINS SOME TIME FOR MOISTURE TO
INCREASE...AND IT STILL SEEMS WITHIN REASON THAT DEWPOINTS WILL
REACH THE UPPER 40S TO LOW 50S WITHIN THE NEXT FEW HOURS. LOCAL
HIGH RESOLUTION MODELS...INCLUDING THE TTUWRF AND TO A LESSER EXTENT
THE HRRR... SEEM TO BE SUGGESTING THAT INITIATION MAY HOLD OFF UNTIL
00Z... HOWEVER THE RUC IS STILL FIRING AROUND 22Z. GIVEN CURRENT
TRENDS... IT SEEMS THAT THE LATER INITIATION SOLUTIONS SEEM MORE
PLAUSIBLE. GIVEN THE VERY STRONGLY SHEARED WIND FIELDS... ANY
STORMS THAT CAN MANAGE TO INITIATE EARLY WILL VERY LIKELY BE
SUPERCELLULAR... AND COULD POSE A VERY ISOLATED TORNADO THREAT IF
MOISTURE CAN CONTINUE TO RISE. HOWEVER...THIS THREAT APPEARS TO BE
VERY MARGINAL AT THIS TIME... AND A MORE LIKELY THREAT WILL BE
MARGINALLY SEVERE HAIL TO 1" AND DAMAGING WINDS TO 70 MPH. THE MOST
LIKELY AREA FOR INITIATION STILL APPEARS TO BE NORTH OF LBB AND
EASTWARD TOWARDS THE CHILDRESS AREA. LATER IN THE EVENING...A
PACIFIC FRONT WILL SWEEP THROUGH THE AREA...AND LIKELY INITIATE
MORE STORMS WITH A MORE LINEAR MODE. STORMS WILL LIKELY EXIT THE
AREA TO THE EAST BY 06Z.
FOR TOMORROW...BREEZY WESTERLY WINDS BETWEEN 20-30 MPH WILL PERSIST
ACROSS THE AREA DURING THE AFTERNOON...WHICH WHEN COMBINED WITH LOW DEWPOINTS
WILL RESULT IN ELEVATED FIRE WEATHER CONDITIONS....ESPECIALLY ACROSS
THE ROLLING PLAINS WHERE WARMER TEMPERATURES WILL RESULT IN LOWER RH
VALUES...
LONG TERM...
BY SUNDAY EVENING...FLOW ACROSS THE REGION WILL BE ZONAL TO SLIGHTLY
WEST SOUTHWESTERLY AS TODAY/S WIND MAKER EJECTS INTO THE GREAT
LAKES. TROUGH OUT WEST CONTINUES TO DEEPEN AND APPROACH LATE MONDAY
NIGHT. FLOW BECOMES NORTHWESTERLY BY WEDNESDAY WITH AN EMBEDDED
TROUGH DUE IN ON THURSDAY AND ANOTHER TROUGH DIGGING INTO THE
SOUTHWEST BY FRIDAY THOUGH MORE LATITUDINALLY ORIENTED THAN THE
EARLY WEEK SYSTEM. RIDGING BUILDS OUT WEST WITH STRONG NNW FLOW
WITH DECENT COLD AIR ADVECTION.
COLD FRONT SHOULD FINALLY MAKE IT INTO THE AREA SUNDAY EVENING WITH
WINDS BECOMING MORE OR LESS EASTERLY AND REMAINING IN FAVORABLE
UPSLOPE REGIME FOR MOISTURE ADVECTION. NAM/GFS/ECM HAVE COME INTO
GOOD AGREEMENT WITH SOME FAIRLY SUBSTANTIVE MOISTURE ADVECTION
MONDAY EVENING PERHAPS MAKING IT A BIT FURTHER WEST THAN EARLIER
THOUGHT. NEVERTHELESS...GENERAL TRENDS IN THE FORECAST REMAIN
INSOFAR AS MOISTURE GOES...BUT...WITH THE GREATER
MOISTURE...PRECIPITATION PHASE IS A BIT LESS CERTAIN WITH PHASE
REMAINING LIQUID UNTIL WRAP AROUND ON THE BACK SIDE OF THE
LOW...WITH LOWER TEMPS. GIVEN THIS FAIRLY RADICAL CHANGE THIS
RUN...WILL HOLD OFF ON MAKING MAJOR CHANGES TO ONGOING FORECAST FOR
NOW.
INTO WEDNESDAY...DRIER AIR WILL CONTINUE TO FILTER INTO THE REGION
AND START A WARMING TREND AFTER BOTTOMING OUT ON TUESDAY. THOUGH
WINDS BACK TO SOUTHWESTERLY ON WEDNESDAY...COLD FRONT IN WEDNESDAY
NIGHT/THURSDAY MORNING WILL USHER IN BREEZY NORTHERLY WINDS ONCE
AGAIN WITH YET COOLER AIR SURGING SOUTHWARD INTO FRIDAY WITH DRY
WEATHER TO PREVAIL.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 25 53 20 50 24 / 0 0 0 10 40
TULIA 28 57 26 51 26 / 0 0 0 10 40
PLAINVIEW 29 58 24 54 26 / 0 0 0 0 40
LEVELLAND 29 59 24 57 24 / 0 0 0 0 20
LUBBOCK 31 60 23 57 26 / 0 0 0 0 20
DENVER CITY 25 59 29 58 30 / 0 0 0 0 20
BROWNFIELD 29 60 24 59 28 / 0 0 0 0 20
CHILDRESS 36 65 26 56 27 / 50 0 0 0 40
SPUR 36 64 29 59 31 / 20 0 0 0 20
ASPERMONT 40 66 30 62 36 / 20 0 0 0 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1001 PM CST SAT FEB 9 2013
.UPDATE...
HAVE DONE A QUICK UPDATE TO CLEAN UP THE GRIDS AND TRIM BACK POPS.
SEVERE CONVECTION HAS QUICKLY COME TO AN END...THOUGH WE COULD
STILL SEE A FEW SHOWERS OR STORMS YET OVER THE NEXT HOUR OR TWO
ACROSS THE FAR EASTERN ZONES BEFORE THE PACIFIC FRONT CLEARS THE
AREA. OTHERWISE...DRY AND BREEZY CONDITIONS WILL BE THE RULE
BEHIND THE FRONT OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 821 PM CST SAT FEB 9 2013/
UPDATE...
WE HAVE ALLOWED THE WIND ADVISORY AND WARNING TO EXPIRE ON
SCHEDULE AT 8 PM. WINDS...IN GENERAL...ARE COMING DOWN...THOUGH A
FEW SPOTS IMMEDIATELY BEHIND THE ADVANCING PACIFIC FRONT MAY
BRIEFLY TOUCH ADVISORY LEVELS. OTHER CONCERN WILL CONTINUE TO
REVOLVE AROUND DEVELOPING CONVECTION THAT IS FORMING ACROSS THE
NORTHEAST ZONES CURRENTLY. THIS CONVECTION IS OCCURRING IN A
WEAKLY UNSTABLE AIRMASS...BUT IS SUPPORTED BY INCREASING LARGE
SCALE ASCENT AND INCREASED LOW-LEVEL FORCING AS A PACIFIC FRONT
IS IMPINGING ON THE IMPROVED LOW-LEVEL MOISTURE RESIDING ACROSS
ROUGHLY THE EASTERN HALF OF THE CWA. COULD YET SEE A FEW
STRONG/SEVERE STORMS...LIKELY FAVORING THE NORTHEAST ZONES. IT
BECOMES MORE UNCERTAIN HOW FAR SOUTH THE CONVECTION CAN DEVELOP
INTO THE ROLLING PLAINS AS LOW-LEVEL CONVERGENCE IS PROGGED TO
WEAKEN WITH SOUTHERN EXTENT AND CIN INCREASE.
REGARDLESS...CONVECTION WILL QUICKLY SHIFT EAST...AND LIKELY BE
OUT OF THE CWA BY MIDNIGHT.
PREV DISCUSSION... /ISSUED 540 PM CST SAT FEB 9 2013/
AVIATION...
GUSTY STRONG WINDS WILL BE THE MAIN CONCERN AT BOTH TERMINALS
THROUGH 1 OR 2Z...AFTER WHICH THE WINDS SHOULD DECREASE TO LESS
THAN ABOUT 18 KTS SUSTAINED. SOME LIGHT BLOWING DUST IS EXPECTED AT
KLBB THROUGH 1Z. ALSO...THERE IS A CHANCE OF TSRA IN THE VICINITY
OF KCDS THROUGH ABOUT 4Z. A FRONT WILL MOVE EAST ACROSS THE AREA
BEFORE MIDNIGHT BRINGING A WIND SHIFT FROM SW TO WEST BUT WITH NOT
MUCH CHANGE IN WIND SPEED GIVEN THE TIME OF DAY. SUNDAY
MORNING...THE WINDS WILL RAMP UP AGAIN AS STRONG W-NW WINDS ALOFT
MIX DOWN. SOME LIGHT BLOWING DUST WILL BE POSSIBLE AT LUBBOCK
AGAIN BY MIDDAY. THE WINDS WILL START TO DIMINISH SUNDAY
AFTERNOON.
PREV DISCUSSION... /ISSUED 304 PM CST SAT FEB 9 2013/
SHORT TERM...
A BUSY AFTERNOON IS IN STORE FOR THE CWA... WITH BOTH HIGH WINDS IN THE
WEST AND THE POSSIBILITY FOR STORMS IN THE EAST. AS EXPECTED... A
POTENT TROUGH IS CURRENTLY ADVANCING ON WEST TEXAS... WITH A 500MB
KT MAX OF OVER 100KT CURRENTLY SITUATED OVER EASTERN NEW MEXICO.
HIGH CLOUDS HAVE CLEARED OVER MOST OF THE NW PORTION OF THE CWA AND
NEW MEXICO...ALLOWING FOR DEEP MIXING AND VERY STRONG WINDS ACROSS
MOST OF EASTERN NEW MEXICO. WINDS HAVE BEEN SLOW TO VEER IN WEST
TEXAS THIS AFTERNOON...ALLOWING DEWPOINTS TO CLIMB INTO THE UPPER
30S AND NEAR 40 ACROSS MOST OF THE CAPROCK AS OF 18Z. HOWEVER...
SURFACE OBS AND RADAR TRENDS ARE INDICATING THAT WINDS ARE FINALLY
BEGINNING TO VEER SLIGHTLY IN THE WEST... WHICH HAS RESULTED IN
RAPID DRYING AND INCREASING WIND SPEEDS JUST EAST OF THE TEXAS NEW
MEXICO BORDER. GIVEN THESE TRENDS... HAVE OPTED TO UPGRADE
PARMER...CASTRO AND BAILEY COUNTIES TO A HIGH WIND WARNING THROUGH
02Z. FIRE WEATHER CONCERNS ARE STILL MINIMAL... ESPECIALLY GIVEN
THE HIGHER THAN ANTICIPATED DEWPOINTS ACROSS THE WEST AND MOIST FUEL
CONDITIONS... HOWEVER ELEVATED FIRE WEATHER CONDITIONS AND SOME
RED FLAG MINUTES WILL BE PRESENT NEAR THE TX/NM BORDER THROUGH
THE EARLY EVENING WHERE THE AIR WILL BE DRIEST AND WINDS
STRONGEST.
FURTHER EAST... THE FORECAST STILL APPEARS TO BE LARGELY ON TRACK AS
MOISTURE CONTINUES TO RETURN ACROSS THE EAST. RADAR AND SURFACES
OBSERVATIONS INDICATE THE BEGINNINGS OF A DRYLINE FORMING JUST TO
THE EAST OF THE TX/NM STATE LINE...AND APPEARS TO BE SLOWLY
ADVANCING EAST. IN ADDITION... VISIBLE SATELLITE IMAGERY IS SHOWING
AN INCREASE IN CUMULIFORM CLOUDS JUST TO THE DRY SIDE OF THIS
DEVELOPING DRYLINE. DEWPOINTS AS OF 20Z HAVE REACHED THE UPPER 40S
ACROSS THE SOUTHEAST...TO NEAR 40 IN THE NORTHERN ROLLING
PLAINS...WHICH IS A BIT LOWER THAN YOU WOULD LIKE FOR STORM
DEVELOPMENT. AS SUCH... INSTABILITY IS STILL VERY WEAK ACROSS THE
AREA...WITH MAXIMUM VALUES OF NEAR 500 J/KG RESTRICTED TO THE
SOUTHEAST. THERE STILL REMAINS SOME TIME FOR MOISTURE TO
INCREASE...AND IT STILL SEEMS WITHIN REASON THAT DEWPOINTS WILL
REACH THE UPPER 40S TO LOW 50S WITHIN THE NEXT FEW HOURS. LOCAL
HIGH RESOLUTION MODELS...INCLUDING THE TTUWRF AND TO A LESSER EXTENT
THE HRRR... SEEM TO BE SUGGESTING THAT INITIATION MAY HOLD OFF UNTIL
00Z... HOWEVER THE RUC IS STILL FIRING AROUND 22Z. GIVEN CURRENT
TRENDS... IT SEEMS THAT THE LATER INITIATION SOLUTIONS SEEM MORE
PLAUSIBLE. GIVEN THE VERY STRONGLY SHEARED WIND FIELDS... ANY
STORMS THAT CAN MANAGE TO INITIATE EARLY WILL VERY LIKELY BE
SUPERCELLULAR... AND COULD POSE A VERY ISOLATED TORNADO THREAT IF
MOISTURE CAN CONTINUE TO RISE. HOWEVER...THIS THREAT APPEARS TO BE
VERY MARGINAL AT THIS TIME... AND A MORE LIKELY THREAT WILL BE
MARGINALLY SEVERE HAIL TO 1" AND DAMAGING WINDS TO 70 MPH. THE MOST
LIKELY AREA FOR INITIATION STILL APPEARS TO BE NORTH OF LBB AND
EASTWARD TOWARDS THE CHILDRESS AREA. LATER IN THE EVENING...A
PACIFIC FRONT WILL SWEEP THROUGH THE AREA...AND LIKELY INITIATE
MORE STORMS WITH A MORE LINEAR MODE. STORMS WILL LIKELY EXIT THE
AREA TO THE EAST BY 06Z.
FOR TOMORROW...BREEZY WESTERLY WINDS BETWEEN 20-30 MPH WILL PERSIST
ACROSS THE AREA DURING THE AFTERNOON...WHICH WHEN COMBINED WITH LOW DEWPOINTS
WILL RESULT IN ELEVATED FIRE WEATHER CONDITIONS....ESPECIALLY ACROSS
THE ROLLING PLAINS WHERE WARMER TEMPERATURES WILL RESULT IN LOWER RH
VALUES...
LONG TERM...
BY SUNDAY EVENING...FLOW ACROSS THE REGION WILL BE ZONAL TO SLIGHTLY
WEST SOUTHWESTERLY AS TODAY/S WIND MAKER EJECTS INTO THE GREAT
LAKES. TROUGH OUT WEST CONTINUES TO DEEPEN AND APPROACH LATE MONDAY
NIGHT. FLOW BECOMES NORTHWESTERLY BY WEDNESDAY WITH AN EMBEDDED
TROUGH DUE IN ON THURSDAY AND ANOTHER TROUGH DIGGING INTO THE
SOUTHWEST BY FRIDAY THOUGH MORE LATITUDINALLY ORIENTED THAN THE
EARLY WEEK SYSTEM. RIDGING BUILDS OUT WEST WITH STRONG NNW FLOW
WITH DECENT COLD AIR ADVECTION.
COLD FRONT SHOULD FINALLY MAKE IT INTO THE AREA SUNDAY EVENING WITH
WINDS BECOMING MORE OR LESS EASTERLY AND REMAINING IN FAVORABLE
UPSLOPE REGIME FOR MOISTURE ADVECTION. NAM/GFS/ECM HAVE COME INTO
GOOD AGREEMENT WITH SOME FAIRLY SUBSTANTIVE MOISTURE ADVECTION
MONDAY EVENING PERHAPS MAKING IT A BIT FURTHER WEST THAN EARLIER
THOUGHT. NEVERTHELESS...GENERAL TRENDS IN THE FORECAST REMAIN
INSOFAR AS MOISTURE GOES...BUT...WITH THE GREATER
MOISTURE...PRECIPITATION PHASE IS A BIT LESS CERTAIN WITH PHASE
REMAINING LIQUID UNTIL WRAP AROUND ON THE BACK SIDE OF THE
LOW...WITH LOWER TEMPS. GIVEN THIS FAIRLY RADICAL CHANGE THIS
RUN...WILL HOLD OFF ON MAKING MAJOR CHANGES TO ONGOING FORECAST FOR
NOW.
INTO WEDNESDAY...DRIER AIR WILL CONTINUE TO FILTER INTO THE REGION
AND START A WARMING TREND AFTER BOTTOMING OUT ON TUESDAY. THOUGH
WINDS BACK TO SOUTHWESTERLY ON WEDNESDAY...COLD FRONT IN WEDNESDAY
NIGHT/THURSDAY MORNING WILL USHER IN BREEZY NORTHERLY WINDS ONCE
AGAIN WITH YET COOLER AIR SURGING SOUTHWARD INTO FRIDAY WITH DRY
WEATHER TO PREVAIL.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 25 53 20 50 24 / 0 0 0 10 40
TULIA 28 57 26 51 26 / 0 0 0 10 40
PLAINVIEW 29 58 24 54 26 / 0 0 0 0 40
LEVELLAND 29 59 24 57 24 / 0 0 0 0 20
LUBBOCK 31 60 23 57 26 / 0 0 0 0 20
DENVER CITY 25 59 29 58 30 / 0 0 0 0 20
BROWNFIELD 29 60 24 59 28 / 0 0 0 0 20
CHILDRESS 36 65 26 56 27 / 50 0 0 0 40
SPUR 36 64 29 59 31 / 20 0 0 0 20
ASPERMONT 40 66 30 62 36 / 20 0 0 0 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33/23
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
230 AM CST SUN FEB 10 2013
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
230 AM CST SUN FEB 10 2013
FORECAST FOCUS IS ON THE STORM SYSTEM THAT SLIDES ACROSS THE REGION
TODAY...WITH CONTINUING PCPN INTO MONDAY.
LATEST WATER VAPOR SATELLITE IMAGERY PLACES THE SHORTWAVE OVER THE
SOUTHERN PLAINS...WITH THE 00Z MODEL RUNS ALL DRIVING IT NORTHEAST
ACROSS THE FORECAST AREA BY THIS EVENING. RELATIVELY WEAK
FRONTOGENETIC FORCING VIA NAM12/RAP LOOKS RESPONSIBLE FOR THE
CURRENT BAND OF LIGHT PCPN RUNNING NORTHWEST-SOUTHEAST FROM SOUTHERN
MN THROUGH IA. THIS WILL CONTINUE TO LIFT NORTHEAST THROUGH THE
MORNING. THE BULK OF THIS SYSTEM/S FORCING IS POST THIS BAND
HOWEVER...WITH THE STRONG LOW LEVEL THERMODYNAMIC LIFT VIA WARM
ADVECTION/ISENTROPIC UPGLIDE ON THE LEADING EDGE OF THE SHORTWAVE
LIFTING ACROSS THE REGION FROM THE LATE MORNING THROUGH THE
AFTERNOON. THE MODELS KEY ON THIS FORCING FOR THE SYSTEM/S MAIN PCPN
BAND. PLENTY OF MOISTURE TO WORK WITH FOR EARLY FEB...WITH A STRONG
PUSH OF 850 MB MOISTURE TRANSPORT ON THE NOSE OF 50 KT LOW LEVEL
JET. PWS ARE NEARLY 300 PERCENT ABOVE NORMAL WITH SREF ANOMALIES
AROUND +3. IN ADDITION...THE FRONTOGENETIC FORCING IS NEARLY UPRIGHT
AT TIMES...PER NORTHEAST-SOUTHWEST RUNNING X-SECTIONS...AND THIS
COUPLED WITH THE NOSE OF THE LOW LEVEL JET COULD RESULT IN SOME
CONVECTION. A CRACK OR TWO OF THUNDER CAN/T BE RULED OUT...MOSTLY TO
THE SOUTH.
THE PCPN BAND MOVES NORTH OF THE FORECAST AREA BY 00Z...WITH THE
STORM SYSTEM/S SFC LOW OVER NORTHERN IA BY THIS TIME. NAM/GFS
CONTINUE TO INDICATE THAT A SMALLER AREA OF PCPN WILL DEVELOP WITH
THE LOW...ASSOCIATED WITH UPPER LEVEL ENERGY BEING WRAPPED HARD
AROUND THE STORM...AND SOME SFC TROUGHINESS RESULTING IN
CONVERGENCE. THIS AREA OF ENHANCED QPF WOULD FALL ACROSS SOUTHEAST
MN THIS EVENING...SHUFFLING ACROSS NORTHERN WI OVERNIGHT.
ELSEWHERE...ENOUGH BROADSCALE LIFT WITH AMPLE SATURATION THAT AREAS
OF LIGHT PCPN ARE LIKELY. WITH THE COLD FRONTAL PASSAGE IN THE
EVENING...EXPECT A TRANSITION FROM RAIN TO SNOW.
THE SNOW WILL LINGER ON MONDAY...WITH AN INVERTED SFC TROUGH HANGING
WEST OF THE EASTWARD MOVING LOW...BITS OF UPPER LEVEL ENERGY...AND
FAVORABLE LOW LEVEL LAPSE RATES HELPING SPARK THE SNOW. THE BETTER
CHANCES WILL LIE MOSTLY ALONG AND NORTH OF I-90...WITH ADDITIONAL
ACCUMULATIONS ON MONDAY OF AN INCH OR LESS.
AS IT HAS APPEARED THE PAST FEW DAYS...THERE APPEARS TO BE 3
DIFFERENT PCPN PHASES WITH THIS STORM SYSTEM...OR PERHAPS 4 NOW.
SFC OBS WITH THE FRONTOGENETIC PCPN BAND MOVING NORTHEAST INDICATES
MOSTLY RAIN RIGHT NOW...ALTHOUGH THE CONVECTIVE NATURE WOULD SUGGEST
THAT ANY HIGH RETURNS COULD BE...OR PERHAPS ARE MORE LIKELY TO
BE...SLEET. RAP BUFKIT SOUNDINGS OVER NORTHEAST IA HAVE A 1-2 C WARM
LAYER...WHICH GRADUALLY DEEPENS. THE ATMOSPHERE CONTINUES TO
WARM...BUT AS IT DOES...THE CLOUDS LOSE THEIR ICE BEHIND THIS FIRST
PCPN BAND. CURRENT IR/SATELLITE CLOUD TEMPS INDICATE THIS AS WELL.
SO...COULD SEE A FREEZING RAIN/SLEET MIX CHANGE OVER TO FREEZING
DRIZZLE FOR EARLY THIS MORNING...ALL SFC TEMP DEPENDENT OF COURSE.
BUT REMEMBER - EVEN AS TEMPS WARM THROUGH THE DAY...ROAD TEMPS ARE
COLDER...MOSTLY IN THE UPPER 20S...AND ICY SPOTS WILL DEVELOP IF
THEY ARE UNTREATED.
THE MAIN BAND OF PCPN...THE BAND THAT WILL BRING MOST OF THE QPF TO
THE FORECAST AREA...IS EXPECTED TO DEVELOP JUST TO THE
SOUTHWEST...MOVING NORTHEAST ACROSS THE REGION LATE
MORNING/AFTERNOON. GOOD PUSH OF LOW LEVEL WARM AIR WITH THIS
PCPN...GENERALLY 1-3 C AT MAX. THIS IS SUGGESTIVE OF ONLY PARTIAL
MELTING...WHICH WOULD RESULT IN SLEET. HOWEVER...THE DEPTH OF THIS
WARM LAYER EXCEEDS 3 KFT IN SOME LOCATIONS - WHICH COULD RESULT IN
FULL MELTING. HOWEVER...THE TRACK OF THE SYSTEM KEEPS IT A BIT
COLDER WEST OF THE MISSISSIPPI RIVER...EVIDENCED IN A WEST-EAST
RUNNING X-SECTION AND BUFKIT SOUNDINGS. NAM12 BUFKIT SOUNDINGS AT
KRST WOULD FAVOR SNOW TO A SNOW/RAIN MIX...SFC TEMP DEPENDENT. NOT
MUCH OF A DENDRITIC SNOW REGION...BUT ITS ISOTHERMAL AROUND 0 C FOR
A FEW HOURS. WOULD EXPECT A WET SNOW WITH LOWER SNOW RATIOS. WILL
HAVE TO TREND FROM WEST TO EAST AND SOUTH TO NORTH WITH PCPN TYPES.
AFTER THIS BAND GOES THROUGH THE MODELS CONTINUE TO POINT TO A
SHALLOWING OF THE CLOUD LAYER AND LOSS OF ICE AS A MID LEVEL DRY
INTRUSION WORKS ACROSS THE REGION. DRIZZLE WOULD BE THE PCPN
TYPE...OUTSIDE OF THE BAND OF PCPN ASSOCIATED WITH THE WRAP AROUND
ENERGY. THAT SHOULD FALL AS SNOW.
THE CLOUD LAYER DEEPENS AGAIN AND WELCOMES ICE BACK INTO THE PTYPE
EQUATION EARLY THIS EVENING...POST THE SYSTEM/S COLD FRONT. AREAS OF
LIGHT SNOW ARE LIKELY...WITH MINOR ACCUMULATIONS. THIS SNOW
CONTINUES ON MONDAY...AS ALREADY MENTIONED.
OVERALL...ITS A MESS. A LOT GOING ON WITH ONLY SMALL CHANGES IN HOW
WARM IT GETS AND/OR DEPTH OF THE WARM LAYER HAVING A SIGNIFICANT
IMPACT ON WHAT FALLS. THAT DOESN/T EVEN INCLUDE THE YES/NO ICE IN
THE CLOUD QUESTION. IT DOES APPEAR THERE COULD BE A BIT MORE FROZEN
PCPN THEN PREVIOUS FORECASTS HAVE INDICATED. EITHER WAY...THE WINTER
WEATHER ADVISORY LOOKS GOOD AND WILL CONTINUE.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
230 AM CST SUN FEB 10 2013
MODELS REMAIN AT ODDS IN HOW TO HANDLE A NORTHWEST FLOW SHORTWAVE
SLATED TO SPIN ACROSS THE REGION TOWARD THE END OF THE WORK WEEK.
THE GFS MOVES THIS FEATURE IN WED NIGHT...KICKING IT EAST BY THU
NIGHT. THE EC IS WEAKER WITH THIS SHORTWAVE...AND SLOWER...NOT
MOVING IT UNTIL THU. IT MIGHT BE A BIT MORE SOUTH TOO. THE GEM SIDES
MORE TOWARD THE GFS WITH STRENGTH AND POSITIONING...BUT IS
SLOWER...ALSO MOVING IN OVERNIGHT WED. ALL PRODUCE QPF...MORE IN THE
GEM/GFS...AND ALL WOULD BE SNOW. GOOD AMOUNT OF CONSISTENCY IN THE
EC WITH POSITIONING...ALTHOUGH STRENGTH HAS VARIED. THE GFS HAS
JUMPED AROUND. WILL LEAN ON AN EC/CONSENSUS SOLUTION FOR THIS TIME
PERIOD.
THE WEEKEND LOOKS COLDER AS A DEEPER UPPER LEVEL TROUGH IS CARVED
OUT POST THE WED/THU SHORTWAVE. HIGHS IN THE TEENS WITH LOWS CLOSE
TO ZERO LOOK REASONABLE.
&&
.AVIATION...THROUGH 06Z MONDAY
1139 PM CST SAT FEB 9 2013
COMPLICATED FORECAST RUNNING THROUGH THE NEXT 24 HOURS AS A STORM
SYSTEM APPROACHES FROM THE SOUTHWEST. CURRENTLY...IFR TO MVFR
CEILINGS HAVE BEEN CLEARING FROM THE SOUTH ACROSS SOUTHERN
WISCONSIN AND SOUTH CENTRAL MINNESOTA/NORTHEAST IOWA. CEILINGS
COULD IMPROVE TO VFR EARLY SUNDAY MORNING...BUT THEN WILL LIKELY
DROP DOWN AGAIN ONCE THE NEXT BAND OF PRECIPITATION MOVES IN.
TIMING STILL LOOKS GOOD FOR THE FIRST WAVE OF SLEET/RAIN/FREEZING
RAIN/SNOW TO MOVE IN AROUND 8Z AT RST AND 10Z AT LSE BUT THEN IT
APPEARS THAT A DRY SLOT WILL COME IN BEHIND IT FOR A PERIOD. COULD
SEE SOME DRIZZLE/FREEZING DRIZZLE AFTER THIS FIRST BAND COMES
THROUGH...THOUGH NOT MANY OBSERVATIONS UPSTREAM ARE SHOWING ANY OF
THAT. THE MAIN SLUG OF PRECIPITATION COMES IN LATER SUNDAY MORNING
AND STILL LOOKS LIKE IT WILL BE A WINTRY MIX. LSE SHOULD BE MORE
ON THE RAIN SIDE WHILE RST SHOULD BE MORE ON THE SNOW/SLEET SIDE.
AFTER ANOTHER LULL AFTER THIS BAND MOVES THROUGH...SOME FOG SHOULD
SET UP OUT AHEAD OF THE SURFACE LOW THAT WILL BRING A COLD FRONT
INTO RST SUNDAY EVENING.
&&
.HYDROLOGY...
230 AM CST SUN FEB 10 2013
MORNING RAIN...COUPLED WITH A FEW INCHES OF SNOW PACK...WILL LEAD TO
RUNOFF INTO AREA WATERWAYS. NEARLY A FULL RELEASE AS GROUNDS ARE
FROZEN. EXPECT SOME IN BANK RISES...BUT UNLESS EXPECTED AMOUNTS ARE
SIGNIFICANTLY HIGHER...DON/T ANTICIPATE ANY WIDESPREAD FLOODING
CONCERNS. THE POTENTIAL FOR ICE JAMS WILL HAVE TO BE MONITORED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
230 AM CST SUN FEB 10 2013
WI...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ032>034-041-
042-053>055-061.
WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING TO 6 PM CST THIS
EVENING FOR WIZ017-029-043-044.
MN...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ086-087-094-
095.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ079-088-096.
IA...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR IAZ008>010-018-
019-029.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR IAZ011-030.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION.....HALBACH
HYDROLOGY....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1139 PM CST SAT FEB 9 2013
.SHORT TERM...TONIGHT INTO SUNDAY
849 PM CST SAT FEB 9 2013
MAIN FOCUS THIS EVENING IS ON THE PRECIPITATION TYPE TRENDS GOING
INTO THE OVERNIGHT HOURS AND SUNDAY MORNING. BASED ON THE LATEST 6
HOURS OR SO OF RAP SOUNDINGS AND THE LATEST 10.00Z NAM
SOUNDINGS...WILL BE MAKING SOME ADJUSTMENTS TO THE PRECIPITATION
TYPES DUE TO WARM LAYER TEMPERATURES NOT LOOKING AS WARM ACROSS
SOUTHEAST MINNESOTA AND WEST CENTRAL WISCONSIN.
IN SE MN/WC WI... THE 10.01Z RAP AND 10.00Z NAM BUFKIT SOUNDINGS
SUGGEST THAT THE WARM LAYER DOES NOT GET MUCH ABOVE THE 0-2C RANGE
UNTIL AFTER 12Z SUNDAY. TOP DOWN APPROACH SAYS THAT THE THE MAIN
PRECIPITATION TYPES WOULD BE SNOW AND SLEET STARTING TONIGHT
BETWEEN 6-12Z. THEREFORE...WILL BE BUMPING UP THESE TOTALS A LITTLE
BIT FOR THE OVERNIGHT PERIOD.
THE THREAT FOR FREEZING RAIN LOOKS TO BE THE HIGHEST ACROSS
NORTHEAST IOWA AND SOUTHWEST WISCONSIN WHERE THE WARM LAYER GETS
INTO THE +3 TO +6C RANGE QUICKER THAN AREAS TO THE NORTH.
HOWEVER...SURFACE TEMPERATURES ARE ALREADY HOVERING AROUND 30-32F
IN THIS AREA...SO IMPACT MAY NOT BE TOO SIGNIFICANT THERE. AS THE
RAIN/PRECIPITATION STARTS TO FALL...LATENT HEAT RELEASE WILL HELP
TO PUSH THESE TEMPERATURES UP A FEW DEGREES AND THE SOUTHERLY WARM
AIR ADVECTION WILL ALSO HELP TO KEEP TEMPERATURES ON A WARMING
TREND OVERNIGHT INTO TOMORROW. THIS MEANS THAT THE PERIOD OF
FREEZING RAIN WILL LIKELY BE BRIEF BEFORE IT GOES TO JUST REGULAR
RAIN.
OTHERWISE...THE TIMING OF THE SYSTEM STILL LOOKS ON TRACK WITH THE
LAYOUT OF THE ADVISORIES AND WITH THE MIX OF PRECIPITATION
TYPES...A WINTER WEATHER ADVISORY STILL LOOKS LIKE THE WAY TO GO
FOR SOME OF THE SLICK SPOTS THAT WILL LIKELY FORM ON UNTREATED
ROADS/SURFACES. THERE HAVE BEEN A FEW THUNDERSTORMS NOTED FROM
NORTHWEST MISSOURI INTO EASTERN SOUTH DAKOTA THIS EVENING OUT IN
THE LEADING PRECIPITATION BAND...BUT CONFIDENCE IS NOT HIGH ENOUGH
THAT THESE WILL OCCUR INTO THE UPPER MISSISSIPPI RIVER VALLEY AS
10.01Z RAP 0-6KM MUCAPE REMAINS LESS THAN 100 J/KG THROUGH
TOMORROW MORNING. STILL WOULD NOT BE SURPRISED TO HAVE SOME
THUNDERSLEET OCCUR OVERNIGHT INTO TOMORROW MORNING GIVEN THE LARGE
SCALE LIFT ASSOCIATED WITH THIS SYSTEM.
.LONG TERM...TUESDAY THROUGH SATURDAY
238 PM CST SAT FEB 9 2013
NORTHWEST FLOW WILL SET UP BEHIND THE DEPARTING STORM SYSTEM
MONDAY. THIS WILL ALLOW A SYSTEM TO DROP INTO THE UPPER MIDWEST
THURSDAY. SOME DIFFERENCE ON HOW LONG THE LONG WAVE TROUGH WILL BE
OVER THE UPPER MIDWEST AS THE 09.12Z ECMWF AND GEM HOLD ONTO IT AS
IT CONNECTS TO ENERGY DROPPING INTO THE DESERT SOUTHWEST WHILE THE
GFS IS A LITTLE MORE PROGRESSIVE. VERY LITTLE TIME SPENT
DIAGNOSING THIS SYSTEM SO WILL LET THE MODEL CONSENSUS GRIDS RIDE
WITH A CHANCE OF PRECIPITATION FROM THURSDAY INTO FRIDAY OR
FRIDAY NIGHT.
&&
.AVIATION...THROUGH 06Z MONDAY
1139 PM CST SAT FEB 9 2013
COMPLICATED FORECAST RUNNING THROUGH THE NEXT 24 HOURS AS A STORM
SYSTEM APPROACHES FROM THE SOUTHWEST. CURRENTLY...IFR TO MVFR
CEILINGS HAVE BEEN CLEARING FROM THE SOUTH ACROSS SOUTHERN
WISCONSIN AND SOUTH CENTRAL MINNESOTA/NORTHEAST IOWA. CEILINGS
COULD IMPROVE TO VFR EARLY SUNDAY MORNING...BUT THEN WILL LIKELY
DROP DOWN AGAIN ONCE THE NEXT BAND OF PRECIPITATION MOVES IN.
TIMING STILL LOOKS GOOD FOR THE FIRST WAVE OF SLEET/RAIN/FREEZING
RAIN/SNOW TO MOVE IN AROUND 8Z AT RST AND 10Z AT LSE BUT THEN IT
APPEARS THAT A DRY SLOT WILL COME IN BEHIND IT FOR A PERIOD. COULD
SEE SOME DRIZZLE/FREEZING DRIZZLE AFTER THIS FIRST BAND COMES
THROUGH...THOUGH NOT MANY OBSERVATIONS UPSTREAM ARE SHOWING ANY OF
THAT. THE MAIN SLUG OF PRECIPITATION COMES IN LATER SUNDAY MORNING
AND STILL LOOKS LIKE IT WILL BE A WINTRY MIX. LSE SHOULD BE MORE
ON THE RAIN SIDE WHILE RST SHOULD BE MORE ON THE SNOW/SLEET SIDE.
AFTER ANOTHER LULL AFTER THIS BAND MOVES THROUGH...SOME FOG SHOULD
SET UP OUT AHEAD OF THE SURFACE LOW THAT WILL BRING A COLD FRONT
INTO RST SUNDAY EVENING.
&&
.HYDROLOGY...
238 PM CST SAT FEB 9 2013
RAINFALL FROM THE SYSTEM TONIGHT THROUGH SUNDAY COULD POSE SOME
PROBLEMS FOR AREA STREAMS. THE GROUND IS FROZEN SO RUNOFF WILL NOT
BE ABLE TO GO INTO THE GROUND AND WILL QUICKLY FIND ITS WAY INTO
THE STREAMS. NOT EXPECTING HUGE AMOUNTS OF QPF...SO WOULD
PRIMARILY THINK IN BANK RISES WOULD OCCUR. HOWEVER...SOME
LOCALIZED HIGHER QPF AMOUNTS COULD LEAD TO MINOR FLOODING OF
SMALLER STREAMS ALONG WITH SOME ICE JAM POTENTIAL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
238 PM CST SAT FEB 9 2013
WI...WINTER WEATHER ADVISORY FROM 3 AM TO NOON CST SUNDAY FOR
WIZ032>034-041-042-053>055-061.
WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST SUNDAY FOR WIZ017-
029-043-044.
MN...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST SUNDAY
FOR MNZ086-087-094-095.
WINTER WEATHER ADVISORY FROM 3 AM TO NOON CST SUNDAY FOR MNZ079-
088-096.
IA...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST SUNDAY
FOR IAZ008>010-018-019-029.
WINTER WEATHER ADVISORY FROM 3 AM TO NOON CST SUNDAY FOR IAZ011-
030.
&&
$$
SHORT TERM...HALBACH
LONG TERM...04
AVIATION...HALBACH
HYDROLOGY....04
AREA FORECAST DISCUSSION
NWS DES MOINES IA
553 AM CST SUN FEB 10 2013
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
ANOTHER BAND OF PRECIP DEVELOPING ACROSS
SOUTHWEST IOWA INTO NORTHWEST MISSOURI WILL CONTINUE TO ADVECT NORTH
NORTHEAST THROUGH THE MORNING HOURS. THIS BAND HAS DEVELOPED ALONG
THE 295-300K ISENTROPIC LAYER WITH GOOD MOISTURE TRANSPORT AND
THETA-E ADVECTION PRESENT. LIGHT RAIN/DRIZZLE WILL PERSIST OVER
THE CENTRAL AND SOUTHWEST SECTIONS OF THE FORECAST AREA THROUGH 18Z
OR SOONER BEFORE THE DRY SLOW PUNCHES INTO THE STATE LATE THIS
MORNING. LOWERED POPS OVER THE SOUTHERN HALF OF THE FORECAST AREA
TODAY AS A RESULT OF THE DRY SLOT.
FURTHER NORTH...THE TIMING OF CURRENT MIXED PRECIP BAND AFFECTING
NORTHERN IOWA LOOKS TO PUSH OUT OF THE FORECAST AREA BY AROUND 15Z
THIS MORNING. WARMER AIR CONTINUES TO ADVECT INTO THE STATE AND WILL
SWITCH PRECIP OVER TO ALL RAIN BY 18Z OR LIKELY EARLIER. SOUNDINGS
AT ALO BECOME ALL RAIN BY 15Z...WITH MCW TEETERING BETWEEN
FZRA/SN/RAIN B/T 15-18Z. THE 06Z HRRR HAS INITIALIZED WELL WITH
CURRENT RADAR TRENDS AND ENDS THE BULK OF THE PRECIP BY AROUND 16Z.
STILL LIKELY TO SEE LIGHT FZRA/SLEET AND EVEN SNOW MIX UNTIL THEN
AND WILL KEEP ADVISORY TIMING AS IS.
THE TIMING OF THE COLDER TEMPS AND WRAP-AROUND MOISTURE INTO
NORTHWEST IOWA LOOKS TO BE PAST 21Z AND HAVE RAIN/SNOW MIX MENTIONED
OVER THE NORTH. BUFR SOUNDINGS DEPICTING ICE INTRODUCTION BEGINNING
AS EARLY AS 21Z BUT MORE LIKELY CLOSER TO 00Z MONDAY. HAVE MENTION
OF SN/RA ACROSS THE NORTH PAST 21Z.
.LONG TERM /TONIGHT THROUGH SATURDAY/...
UPPER LOW OVER NORTHWEST IOWA AT THE BEGINNING OF THE PERIOD WILL
SHIFT NORTHEAST INTO THE WESTERN GREAT LAKES BY 12Z MONDAY. THIS
WILL HELP SWING A COLD FRONT THROUGH THE STATE THIS EVENING.
STRONG COLD ADVECTION FROM 850-900 MB WILL DEEPEN MIXING THROUGH
THE EVENING. PROXIMITY MODEL SOUNDING PROFILES REMAIN PERSISTENT
WITH 40 TO 45 KTS AVAILABLE WITHIN THE MIXED LAYER AND SHOULD HAVE
SOME OF THESE WINDS TRANSFER TO THE SFC IN THE FORM OF GUSTS WHILE
SUSTAINED WINDS APPROACH 30 MPH FOR A PERIOD. THEREFORE CONFIDENCE
IS HIGH THAT WIND ADVISORY CRITERIA WILL BE MET OVERNIGHT INTO
EARLY MONDAY MORNING BEGINNING SHORTLY AFTER 00Z IN THE WEST. SOME
UNCERTAINTY THOUGH ON HEADLINE TYPE OVER THE NORTH WHERE SOME SNOW
IS LIKELY. ANY SNOW ACCUMULATIONS THIS EVENING ARE EXPECTED TO BE
AN INCH OR LESS WHICH SHOULD NOT CAUSE A BIG PROBLEM CONSIDERING
THERE IS CURRENTLY NO SNOW COVER ACROSS THE AREA. HOWEVER
POTENTIAL IS THERE FOR SOME CONVECTIVE ELEMENTS TO BE ASSOCIATED
WITH AN AREA OF SNOW THIS AFTERNOON INTO THE EARLY EVENING. IF
THIS INDEED DOES DEVELOP AND HIGHER SNOW AMOUNTS APPROACHING 2
INCHES OCCURS...THEN THE FLAVOR OF HEADLINES ASSOCIATED WITH THE
WIND WOULD NEED TO TRANSITION TO WINTER WEATHER. WITH CURRENT
HEADLINE OUT THROUGH MID MORNING AND SOME UNCERTAINLY WITH TYPE
ACROSS THE NORTH...HAVE OPTED TO NOT ISSUE ADDITIONAL HEADLINES
FOR NOW WHICH WOULD ALLOW THE FOLLOWING SHIFT TO ACCESS TRENDS
BEFORE ISSUING.
THE CANADIAN UPPER WAVE WHICH WILL DIVE INTO THE TROUGH CREATED BY
OUR CURRENT SYSTEM...WILL PASS TO THE SOUTH OF THE AREA TUESDAY
AND TUESDAY NIGHT WITH NO SIGNIFICANT WEATHER FORECAST FOR CENTRAL
IOWA. ANOTHER WAVE WILL DROP SOUTH BY WEDNESDAY NIGHT AND WILL
CARVE A TROUGH OUT ACROSS THE NORTHERN PLAINS WITH ANOTHER PUSH OF
COLDER AIR WITH 850 MB TEMPERATURES DROPPING TO -10C. SOME LIGHT
SNOW POTENTIAL WITH THIS PASSING WAVE. SIGNIFICANT DIFFERENCES
BEYOND THAT WITH THE ECMWF MORE PROGRESSIVE PUSHING THE UPPER
RIDGE INTO THE WESTERN PLAINS WHILE THE GFS DETERMINISTIC AND
ENSEMBLES HOLD THE NORTHWEST FLOW FOR A MORE PROLONGED PERIOD.
&&
.AVIATION...10/12Z
LIFR/IFR CIGS WILL PERSIST DURING MUCH OF THE CRITICAL TAF PERIOD AS
A BAND OF DRIZZLE/LIGHT RAIN MOVES ACROSS CENTRAL IOWA. VISIBILITY
WITHIN THIS BAND HAVE DROPPED TO IFR DSM/FOD WILL SEE THESE LOWER
VIS THROUGH 14Z OR SO. KEPT MENTION OF FZRA AT MCW AS TEMPS STILL
REMAIN BELOW FREEZING THROUGH 14Z BEFORE WARMER TEMPS MOVE INTO
NORTHERN IOWA. LOW CONFIDENCE WITH LIFR/IFR CIGS TO IMPROVE UNTIL
AFTER 18Z TODAY AT DSM/OTM. LEANED TOWARD THE MORE PESSIMISTIC NAM
MOS AS IT KEEPS IFR CIGS THROUGH MONDAY MORNING OVER NORTHERN IOWA.
LATEST HRRR MODEL RUN HAS IFR CIGS LIFT BY AROUND 21Z AT FOD...BUT
KEEP ALO/MCW CIGS THROUGH THE AFTERNOON. VERY STRONG WINDS DEVELOP
THIS EVENING AND LIKELY WILL SEE GUSTS OVER 30KTS OVERNIGHT TONIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR
IAZ004>007-016-017.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
409 AM CST SUN FEB 10 2013
.SHORT TERM /TODAY/...
ANOTHER BAND OF PRECIP DEVELOPING ACROSS
SOUTHWEST IOWA INTO NORTHWEST MISSOURI WILL CONTINUE TO ADVECT NORTH
NORTHEAST THROUGH THE MORNING HOURS. THIS BAND HAS DEVELOPED ALONG
THE 295-300K ISENTROPIC LAYER WITH GOOD MOISTURE TRANSPORT AND
THETA-E ADVECTION PRESENT. LIGHT RAIN/DRIZZLE WILL PERSIST OVER
THE CENTRAL AND SOUTHWEST SECTIONS OF THE FORECAST AREA THROUGH 18Z
OR SOONER BEFORE THE DRY SLOW PUNCHES INTO THE STATE LATE THIS
MORNING. LOWERED POPS OVER THE SOUTHERN HALF OF THE FORECAST AREA
TODAY AS A RESULT OF THE DRY SLOT.
FURTHER NORTH...THE TIMING OF CURRENT MIXED PRECIP BAND AFFECTING
NORTHERN IOWA LOOKS TO PUSH OUT OF THE FORECAST AREA BY AROUND 15Z
THIS MORNING. WARMER AIR CONTINUES TO ADVECT INTO THE STATE AND WILL
SWITCH PRECIP OVER TO ALL RAIN BY 18Z OR LIKELY EARLIER. SOUNDINGS
AT ALO BECOME ALL RAIN BY 15Z...WITH MCW TEETERING BETWEEN
FZRA/SN/RAIN B/T 15-18Z. THE 06Z HRRR HAS INITIALIZED WELL WITH
CURRENT RADAR TRENDS AND ENDS THE BULK OF THE PRECIP BY AROUND 16Z.
STILL LIKELY TO SEE LIGHT FZRA/SLEET AND EVEN SNOW MIX UNTIL THEN
AND WILL KEEP ADVISORY TIMING AS IS.
THE TIMING OF THE COLDER TEMPS AND WRAP-AROUND MOISTURE INTO
NORTHWEST IOWA LOOKS TO BE PAST 21Z AND HAVE RAIN/SNOW MIX MENTIONED
OVER THE NORTH. BUFR SOUNDINGS DEPICTING ICE INTRODUCTION BEGINNING
AS EARLY AS 21Z BUT MORE LIKELY CLOSER TO 00Z MONDAY. HAVE MENTION
OF SN/RA ACROSS THE NORTH PAST 21Z.
.LONG TERM /TONIGHT THROUGH SATURDAY/...
UPPER LOW OVER NORTHWEST IOWA AT THE BEGINNING OF THE PERIOD WILL
SHIFT NORTHEAST INTO THE WESTERN GREAT LAKES BY 12Z MONDAY. THIS
WILL HELP SWING A COLD FRONT THROUGH THE STATE THIS EVENING.
STRONG COLD ADVECTION FROM 850-900 MB WILL DEEPEN MIXING THROUGH
THE EVENING. PROXIMITY MODEL SOUNDING PROFILES REMAIN PERSISTENT
WITH 40 TO 45 KTS AVAILABLE WITHIN THE MIXED LAYER AND SHOULD HAVE
SOME OF THESE WINDS TRANSFER TO THE SFC IN THE FORM OF GUSTS WHILE
SUSTAINED WINDS APPROACH 30 MPH FOR A PERIOD. THEREFORE CONFIDENCE
IS HIGH THAT WIND ADVISORY CRITERIA WILL BE MET OVERNIGHT INTO
EARLY MONDAY MORNING BEGINNING SHORTLY AFTER 00Z IN THE WEST. SOME
UNCERTAINTY THOUGH ON HEADLINE TYPE OVER THE NORTH WHERE SOME SNOW
IS LIKELY. ANY SNOW ACCUMULATIONS THIS EVENING ARE EXPECTED TO BE
AN INCH OR LESS WHICH SHOULD NOT CAUSE A BIG PROBLEM CONSIDERING
THERE IS CURRENTLY NO SNOW COVER ACROSS THE AREA. HOWEVER
POTENTIAL IS THERE FOR SOME CONVECTIVE ELEMENTS TO BE ASSOCIATED
WITH AN AREA OF SNOW THIS AFTERNOON INTO THE EARLY EVENING. IF
THIS INDEED DOES DEVELOP AND HIGHER SNOW AMOUNTS APPROACHING 2
INCHES OCCURS...THEN THE FLAVOR OF HEADLINES ASSOCIATED WITH THE
WIND WOULD NEED TO TRANSITION TO WINTER WEATHER. WITH CURRENT
HEADLINE OUT THROUGH MID MORNING AND SOME UNCERTAINLY WITH TYPE
ACROSS THE NORTH...HAVE OPTED TO NOT ISSUE ADDITIONAL HEADLINES
FOR NOW WHICH WOULD ALLOW THE FOLLOWING SHIFT TO ACCESS TRENDS
BEFORE ISSUING.
THE CANADIAN UPPER WAVE WHICH WILL DIVE INTO THE TROUGH CREATED BY
OUR CURRENT SYSTEM...WILL PASS TO THE SOUTH OF THE AREA TUESDAY
AND TUESDAY NIGHT WITH NO SIGNIFICANT WEATHER FORECAST FOR CENTRAL
IOWA. ANOTHER WAVE WILL DROP SOUTH BY WEDNESDAY NIGHT AND WILL
CARVE A TROUGH OUT ACROSS THE NORTHERN PLAINS WITH ANOTHER PUSH OF
COLDER AIR WITH 850 MB TEMPERATURES DROPPING TO -10C. SOME LIGHT
SNOW POTENTIAL WITH THIS PASSING WAVE. SIGNIFICANT DIFFERENCES
BEYOND THAT WITH THE ECMWF MORE PROGRESSIVE PUSHING THE UPPER
RIDGE INTO THE WESTERN PLAINS WHILE THE GFS DETERMINISTIC AND
ENSEMBLES HOLD THE NORTHWEST FLOW FOR A MORE PROLONGED PERIOD.
&&
.AVIATION...10/06Z
COMPLEX SCENARIO DURING FORECAST PACKAGE AS STRONG THETA-E ADVECTION
PRODUCES LIGHT WINTRY PRECIPITATION ACROSS NORTHERN IOWA TONIGHT
INTO SUNDAY MORNING. ANTICIPATE WIDESPREAD IFR CONDITIONS IN MOST
LOCATION BY DAYBREAK AS CEILINGS CRASH ALONG WITH AREAS OF FREEZING
RAIN...SLEET AND SNOW NORTH OF KSLB TO KALO OVERNIGHT. WARMER
SURFACE TEMPERATURES WILL EDGE NORTHWARD WITH MUCH OF THE FORECAST
AREA BECOMING STRAIGHT RAIN BY 12 TO 15Z WITH THE POSSIBLE EXCEPTION
OF KMCW. CEILING MAY IMPROVE ACROSS SOUTHERN IOWA ON SUNDAY AS WARM
SECTOR EDGES INTO THE STATE. WINDS WILL BE STRONG FROM THE SOUTH TO
SOUTHEAST FOR MUCH OF THE FORECAST AS DEEP LOW PRESSURE MOVES INTO
NORTHWEST IOWA. WINDS WILL BECOME WEST TO NORTHWEST TOWARD THE END
OF THE FORECAST PERIOD AS A FRONT PASSES THROUGH THE STATE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
IAZ015-023>028-035>039.
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR
IAZ004>007-016-017.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...COGIL
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1041 AM EST SUN FEB 10 2013
.UPDATE...
ISSUED AT 1040 AM EST SUN FEB 10 2013
FEW CHANGES NEEDED THIS MORNING AS WE TRACK THE APPROACHING SFC LOW
JUST WEST OF COLUMBUS KS /KOLU/ AT 15Z. THE CLOSEST BAND OF
PRECIPITATION STRETCHES FROM NEAR ST. CLOUD MN /KSTC/ SOUTHEASTWARD
THROUGH SOUTHERN WI /NEAR DECORAH WI KDEH/...MOVING NNE AROUND 45KTS.
WHILE SNOW REMAINS THE PREDOMINANT WEATHER TYPE ACROSS THE WESTERN
EDGE...THERE IS A TRANSITION TO MIXED PRECIP AND RAIN TOWARD EASTERN
MN AND WESTERN WI...WHERE PRECIPITATION LOOKS MORE CONVECTIVE WITH
POCKETS OF 45-50DBZ REFLECTIVITY. THERE WERE A FEW...MAINLY
NEGATIVE...LIGHTNING STRIKES ACROSS SW MN AROUND 13Z.
OTHERWISE...LIGHTNING HAS REMAINED WELL TO OUR S ACROSS IA AND IL.
WHILE LIGHTNING IS NOT EXPECTED AS THE SYSTEM NEARS LATER THIS
AFTERNOON...SOME OF THESE STRONGER REFLECTIVITIES WILL PRODUCE
HEAVIER PRECIPITATION...WITH 1IN/HR SNOW AMOUNTS OR GREATER OVER FAR
WESTERN UPPER MI. WILL CONTINUE TO MONITOR THE APPROACHING WINTRY MIX
OF PRECIPITATION. &&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 543 AM EST SUN FEB 10 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED MID LEVEL
LOW LIFTING OUT OVER THE WRN PLAINS...AND 00Z RAOBS AND SFC OBS
INDICATE THAT SYSTEM HAS DEVELOPED A GOOD GULF MOISTURE CONNECTION.
THE MID LEVEL LOW WILL TRACK NE...REACHING THE UPPER LAKES MON
MORNING. ALTHOUGH MODELS ARE IN GOOD AGREEMENT ON THE TRACK OF THE
MID LEVEL LOW AND ASSOCIATED SFC LOW...FCST REMAINS A CHALLENGE
WITH RESPECT TO PTYPES AS EVAPORATIVE AND THEN DYNAMIC COOLING
BATTLE STRONG WAA. WITH THE STRONG WAA REGIME TAPPING A SOLID GULF
MOISTURE FEED...PRECIPITABLE WATER SURGES TO 250-300PCT OF NORMAL IN
THE UPPER LAKES...PROVIDING POTENTIAL FOR HVY PCPN. HOWEVER...
HEAVIEST PCPN WILL BE SHORT-LIVED (ABOUT 4-6HRS) ON THE FRONT SIDE
OF THE SYSTEM AS STRONG ISENTROPIC ASCENT RAPIDLY SHIFTS ACROSS THE
AREA PER 295K SFC WHICH SHOWS 40-50KT WINDS PERPENDICULAR TO
ISOBARS. ALTHOUGH THERE IS ABUNDANT AVBL MOISTURE...QUICK MOVEMENT
OF THIS VIGOROUS ASCENT WILL HELP KEEP PCPN TOTALS IN CHECK. NARROW
MIDLEVEL DRY SLOT PUNCHING N COULD LEAD TO SOME CONVECTIVE PCPN ON
TAIL END OF THE ISENTROPIC ASCENT/MAIN PCPN BAND THIS EVENING
(MODELS ALSO SHOW SHOWALTER INDEX FALLING CLOSE TO 0C). AS FOR
PTYPE...IT REMAINS A TOUGH CALL. FCST SOUNDINGS FROM THE NAM/GFS
SHOW TEMP PROFILE HOVERING NEAR 0C THRU A RATHER SUBSTANTIAL
LOW-LEVEL DEPTH...AND THE NAM IN PARTICULAR SHOWS SURGES OF ABOVE 0C
TEMPS AT TIMES...SUGGESTING EPISODES OF VARYING PTYPES. WITH HIGH
RES TEMP PROFILE INFO NOT AVBL FOR THE UKMET/REGIONAL
GEM/UKMET/ECMWF...USE OF 850MB TEMPS AND 1000-850MB THICKNESS DOES
NOT CLARIFY OR ADD ANY CERTAINTY TO THE PTYPE FCST. OF THOSE
MODELS...THE REGIONAL GEM IS QUITE WARM IN THE LOW-LEVELS AS IT HAS
1000-850MB THICKNESS RISING ABOVE 1300M TONIGHT ACROSS NEARLY THE
ENTIRE FCST AREA AND AS HIGH AS 1320M ACROSS THE SCNTRL/SE FCST
AREA. IF CORRECT...PCPN WOULD CHANGE TO MOSTLY RA/FZRA OVER MUCH OF
THE AREA. AT THIS POINT...WILL INCLUDE MIXED PTYPES ROUGHLY SE OF A
MARQUETTE TO CRYSTAL FALLS LINE. IT MAY BE ONE OF THOSE EVENTS WHERE
PCPN IS MOSTLY SNOW DURING PERIOD OF STRONGEST FORCING/HEAVIEST
PCPN AND THEN MORE OF A MIX OR A TRANSITION TO LIQUID PTYPES DURING
PERIODS OF LIGHT PCPN.
MIXING RATIOS SOLIDLY AROUND 4G/KG ON THE 295K SFC AND ABOUT 6 HRS
OF STRONG ISENTROPIC ASCENT SUGGEST POTENTIAL FOR AROUND 4 INCHES OF
SNOW WHERE PTYPE IS EXCLUSIVELY SNOW. THE SNOW WILL BE WET/HVY DUE
TO A NARROW AND HIGH DGZ (SNOW-TO-WATER WILL PROBABLY BE DOWN AROUND
10 TO 1). STRONGER DEEP LAYER FORCING PER QVECTORS WILL PASS ACROSS
THE NW FCST AREA...SO TOTALS THERE MAY BE HIGHER. IN FACT OVER THE
NW...SNOW AMOUNTS WILL BE CLOSE TO THE WARNING CRITERIA OF 6
INCHES/12HR FOR LOW SNOW TO WATER RATIO SNOW. LATER SHIFTS WILL NEED
TO MONITOR FOR POSSIBLE UPGRADE OF ADVY TO WARNING ACROSS THE
KEWEENAW IN PARTICULAR. AFTER THE PERIOD OF STRONG ISENTROPIC ASCENT
QUICKLY EXITS THIS EVENING...PCPN COVERAGE OVERNIGHT IS MUCH MORE
UNCERTAIN WITH NO COHERENT FORCING. IN ANY EVENT...THE PCPN SHOULD
BE MUCH LIGHTER IN THE WAKE OF THE MAIN BAND OF PCPN EXITING TO THE
N AND E THIS EVENING.
WITH THIS FCST ISSUANCE...OPTED TO INCLUDE THE REMAINDER OF THE FCST
AREA (ALGER/DELTA/MENOMINEE COUNTIES EASTWARD) IN A WINTER WX ADVY
LATE THIS AFTN/TONIGHT GIVEN THE EXPECTED MIXED PCPN AND 1-3 INCHES
OF HVY/WET SNOW IN THAT AREA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 436 AM EST SUN FEB 10 2013
AREA WILL BE IN THE MIDDLE OF THE SYSTEM PRODUCING A VARIETY OF
WINTER PRECIPITATION TYPES. AT 12Z ON MONDAY...THE LOW SHOULD BE
CENTERED OVER SOUTH CENTRAL UPPER MICHIGAN AND SHIFTING TO THE
EAST-NORTHEAST THROUGH THE DAY. UPPER LEVEL DRY SLOT WILL BE EAST OF
THE CWA AT THE START OF THE PERIOD AND WITH THE NEARLY VERTICALLY
STACKED LOW OVER THE SOUTH CENTRAL CWA...EXPECT THE HEAVIEST
PRECIPITATION TO BE JUST TO THE NORTHWEST OF THE LOW CENTER...FROM
THE KEWEENAW THROUGH GOGEBIC COUNTY WHERE THE LOWER LEVEL NOSE OF
LINGERING WARM AIR WRAPPING NW AROUND THE LOW. MEANWHILE...THE REST
OF THE AREA WILL BE SEEING LIGHT PRECIPITATION. THINK THERE WILL BE
ENOUGH WARM AIR ON THE EAST SIDE OF THE LOW TO KEEP SOME MIXED
PRECIPITATION GOING OVER EASTERN UPPER MICHIGAN DURING THE MORNING.
AS THE LOW SHIFTS TO THE EAST AND COLDER AIR SURGES SOUTH IN THE
AFTERNOON...SHOULD SEE A FAIRLY QUICK TRANSITION TO ALL SNOW FROM
THE RAIN/FREEZING RAIN MIX.
WITH THAT COLDER AIR MOVING IN...EXPECT A TRANSITION TO LAKE
ENHANCED SNOW ON MONDAY. EXPECT IT TO OCCUR IN THE NORTH WIND
FAVORED LOCATIONS DURING THE LATE MORNING OVER THE WEST AND THEN
OVER THE EAST IN THE AFTERNOON. WITH MUCH OF THE CLOUD AT THE BOTTOM
OR BELOW THE DGZ FOR MUCH OF MONDAY...DON/T THINK THE SNOW RATIOS
WILL COME UP MUCH FROM THE 10-12 TO 1 RANGE UNTIL LATER IN THE
AFTERNOON WHEN COLDER AIR ARRIVES. ANOTHER 2-4 INCHES IN THE FAVORED
LOCATIONS OUT WEST SEEMS REASONABLE FOR MONDAY...WITH A DUSTING TO 2
INCHES IN OTHER LOCATIONS. AS FOR WINDS...THE TRACK OF THE LOW
SHOULD LIMIT THE AMOUNT OF ENHANCEMENT FROM THE PRESSURE RISE/FALL
COUPLET SINCE THE WINDS WILL BE PERPENDICULAR TO IT. THAT BEING
SAID...NORTHERLY WINDS SHOULD BE ON THE INCREASE THROUGH THE DAY
FROM WEST TO EAST AS COLDER AIR INCREASES THE LOW LEVEL LAPSE RATES.
THINK THE HIGHEST GUSTS WILL BE RIGHT ALONG THE LAKE SUPERIOR
SHORELINE AND WILL PROBABLY SEE A COUPLE HOUR PERIOD OF GUSTS IN THE
30-35MPH RANGE.
MONDAY NIGHT INTO TUESDAY...H900 TEMPS AROUND -13C WILL BE ENOUGH TO
HOLD ONTO LAKE ENHANCED/EFFECT SNOW INTO MONDAY EVENING. BUT...THE
APPROACHING HIGH PRESSURE RIDGE WILL BE INCREASING THE DRY AIR AND
SUBSIDENCE THROUGH THE NIGHT AND LOWER INVERSION HEIGHTS. IN
ADDITION...EXPECT WARMER AIR TO ALSO MOVE SOUTHEAST INTO THE AREA
AND REDUCE THE LAKE INSTABILITY. THUS...EXPECT THE INTENSITY OF THE
SNOW TO DIMINISH THROUGH THE NIGHT WITH JUST LINGERING LIGHT SNOW
SHOWERS BY TUESDAY MORNING IN THE FAVORED NORTHWEST WIND SNOW
BELTS. CLOUDS WILL BE ON THE DECREASE THROUGH TUESDAY AFTERNOON WITH
THE SURFACE RIDGE STARTING TO SHIFT TO THE EAST AND LOWER LEVEL
WINDS BACKING TO THE WEST-SOUTHWEST. THIS IS IN RESPONSE TO THE NEXT
SURFACE TROUGH THAT WILL BE CROSSING THE AREA TUESDAY NIGHT INTO
WEDNESDAY MORNING AS THE MORE DOMINATE SOUTHERN STREAM JET REMAINS
OVER THE SOUTHERN THIRD OF THE CONUS. BEST MOISTURE/FORCING WITH
THIS TROUGH AND SHORTWAVE LOOK TO STAY OVER THE NORTHEAST HALF OF
LAKE SUPERIOR...BUT MAY BRUSH THE KEWEENAW AND FROM MARQUETTE TO
NEWBERRY ON WEDNESDAY.
EXTENDED RANGE MODELS BEGIN TO DIVERGE AFTER THIS POINT...AS A
NORTHERN STREAM WAVE DIVES SOUTHEAST OUT OF ALBERTA AND INTO THE
NORTHERN PLAINS ON WEDNESDAY. THIS WAVE CONTINUES TO DRIVE TO THE
SOUTHEAST AND TRIES TO MERGE/PHASE WITH THE STRONGER SOUTHERN
STREAM. 00Z GFS IS ON THE FARTHER NORTH AND LESS PHASED
SOLUTION...WHILE THE 12Z ECMWF IS THE FARTHEST SOUTHEAST AND THE 12Z
GEM IS IN BETWEEN. 00Z GEM/ECMWF DID TREND CLOSER TO THE GFS
SOLUTION...SO WILL FOLLOW A GENERALLY BLEND AND HAVE THE ASSOCIATED
SURFACE LOW TRACK THROUGH WISCONSIN. WOULD EXPECT SOME SHOWERS TO BE
AFFECTING THE AREA ON THURSDAY AND WILL CONTINUE MENTION OF
CHANCE/SLIGHT POPS. AFTER THURSDAY...GFS/GEM WRAP THE LOW UP AND
HAVE IT SLOWLY DEPART THE GREAT LAKES REGION THROUGH FRIDAY
NIGHT...WHILE THE ECMWF QUICKLY SLIDES IT EAST. WILL SPLIT THE
DIFFERENCE AND HIGHLIGHT CHANCE POPS FOR MUCH OF THE AREA AND
ESPECIALLY OVER THE LAKE EFFECT REGIONS SINCE THERE WILL BE A
NORTHERLY COMPONENT TO THE WINDS AS H850 TEMPS FALL TO 14C ON
FRIDAY. HIGH PRESSURE RIDGE WILL THEN TRY TO MOVE IN FOR FRIDAY
NIGHT INTO SATURDAY AND HAVE GRADUALLY DIMINISHED THE LAKE EFFECT
POPS.
AFTER THE ABOVE NORMAL TEMPERATURES THROUGH WED/THURS...EXPECT A
TRANSITION BACK TO MORE NORMAL TEMPERATURES FOR FRIDAY AND INTO THE
FIRST PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 641 AM EST SUN FEB 10 2013
AT KIWD...IFR CIGS SHOULD RISE SLIGHTLY TO LOW MVFR THIS MORNING AS
DOWNSLOPING E-SE WINDS STRENGTHEN. AT KCMX...EXPECT LOW MVFR CIGS TO
PREVAIL INTO THE AFTN. ALTHOUGH UPSLOPING S-SE WINDS SHOULD WORK TO
MAINTAIN IFR CIGS AT KSAW INTO THE AFTN...SOMEWHAT DRIER AIR WORKING
INTO THE AREA MAY ALLOW CIGS TO RISE TO LOW MVFR. THIS AFTN...
ATTENTION SHIFTS TO LOW PRES ADVANCING NE FROM THE CNTRL PLAINS.
BAND OF PCPN...POSSIBLY MDT/HVY...WILL SWING NE...AFFECTING ALL
TERMINALS FOR SEVERAL HRS DURING THE LATE AFTN/EARLY EVENING. PCPN
SHOULD BE IN THE FORM OF SNOW...BUT SOME PL IS POSSIBLE AT KSAW.
LIFR CONDITIONS ARE LIKELY TO PREVAIL AS THIS MAIN BAND OF PCPN
LIFTS THRU THE AREA. LATER EVENING/OVERNIGHT...LIGHTER AND PROBABLY
MORE INTERMITTENT PCPN IS EXPECTED THOUGH CONDITIONS WILL LIKELY
REMAIN IFR/LIFR. SOME -FZDZ/-FZRA MAY OCCUR AT KSAW DURING THE
NIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 436 AM EST SUN FEB 10 2013
A LOW PRESSURE SYSTEM EXITING THE CENTRAL PLAINS WILL MOVE INTO THE
UPPER GREAT LAKES REGION LATE TONIGHT AND THEN SHIFT EAST ON MONDAY
AFTERNOON. THIS WILL LEAD TO INCREASING EAST-NORTHEAST FLOW OVER
WESTERN LAKE SUPERIOR AND EXPECT GALES TO 40KTS THIS AFTERNOON AND
EVENING. THUS...HAVE ISSUED A GALE WARNING FOR LSZ162/263. THEN AS
THE WINDS TURN TO THE NORTH TONIGHT...EXPECT GALES TO 35-40KTS OVER
THE WEST AND NORTH CENTRAL LAKE THROUGH MONDAY. THERE MAY BE GALES
OVER THE EASTERN LAKE MONDAY AFTERNOON...BUT CONFIDENCE WASN/T HIGH
ENOUGH TO ISSUE A GALE WARNING. A HIGH PRESSURE RIDGE WILL DIMINISH
THE WINDS MONDAY NIGHT INTO TUESDAY.
A SURFACE TROUGH WILL MOVE ACROSS LAKE SUPERIOR TUESDAY NIGHT AND
WEDNESDAY...SHIFTING WINDS TO THE WEST BUT KEEPING THEM BELOW
20KTS. A WEAK LOW PRESSURE SYSTEM WILL THEN MOVE OUT OF THE DAKOTAS
ON WEDNESDAY NIGHT AND INTO WISCONSIN ON THURSDAY.
FREEZING SPRAY IS EXPECTED MONDAY AND MONDAY NIGHT OVER MUCH OF
LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ THIS AFTERNOON
TO 7 AM EST /6 AM CST/ MONDAY FOR MIZ006-007-012>014-085.
WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ THIS AFTERNOON
TO 7 AM EST /6 AM CST/ TUESDAY FOR MIZ002-009.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST
MONDAY FOR MIZ001-003>005-084.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM CST
MONDAY FOR MIZ010-011.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM EST /2 PM CST/ THIS AFTERNOON TO 10 AM
EST /9 AM CST/ MONDAY FOR LSZ162.
GALE WARNING FROM 7 AM TO 7 PM EST MONDAY FOR LSZ264.
GALE WARNING FROM 3 PM THIS AFTERNOON TO 4 PM EST MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KF
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
642 AM EST SUN FEB 10 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 543 AM EST SUN FEB 10 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED MID LEVEL
LOW LIFTING OUT OVER THE WRN PLAINS...AND 00Z RAOBS AND SFC OBS
INDICATE THAT SYSTEM HAS DEVELOPED A GOOD GULF MOISTURE CONNECTION.
THE MID LEVEL LOW WILL TRACK NE...REACHING THE UPPER LAKES MON
MORNING. ALTHOUGH MODELS ARE IN GOOD AGREEMENT ON THE TRACK OF THE
MID LEVEL LOW AND ASSOCIATED SFC LOW...FCST REMAINS A CHALLENGE
WITH RESPECT TO PTYPES AS EVAPORATIVE AND THEN DYNAMIC COOLING
BATTLE STRONG WAA. WITH THE STRONG WAA REGIME TAPPING A SOLID GULF
MOISTURE FEED...PRECIPITABLE WATER SURGES TO 250-300PCT OF NORMAL IN
THE UPPER LAKES...PROVIDING POTENTIAL FOR HVY PCPN. HOWEVER...
HEAVIEST PCPN WILL BE SHORT-LIVED (ABOUT 4-6HRS) ON THE FRONT SIDE
OF THE SYSTEM AS STRONG ISENTROPIC ASCENT RAPIDLY SHIFTS ACROSS THE
AREA PER 295K SFC WHICH SHOWS 40-50KT WINDS PERPENDICULAR TO
ISOBARS. ALTHOUGH THERE IS ABUNDANT AVBL MOISTURE...QUICK MOVEMENT
OF THIS VIGOROUS ASCENT WILL HELP KEEP PCPN TOTALS IN CHECK. NARROW
MIDLEVEL DRY SLOT PUNCHING N COULD LEAD TO SOME CONVECTIVE PCPN ON
TAIL END OF THE ISENTROPIC ASCENT/MAIN PCPN BAND THIS EVENING
(MODELS ALSO SHOW SHOWALTER INDEX FALLING CLOSE TO 0C). AS FOR
PTYPE...IT REMAINS A TOUGH CALL. FCST SOUNDINGS FROM THE NAM/GFS
SHOW TEMP PROFILE HOVERING NEAR 0C THRU A RATHER SUBSTANTIAL
LOW-LEVEL DEPTH...AND THE NAM IN PARTICULAR SHOWS SURGES OF ABOVE 0C
TEMPS AT TIMES...SUGGESTING EPISODES OF VARYING PTYPES. WITH HIGH
RES TEMP PROFILE INFO NOT AVBL FOR THE UKMET/REGIONAL
GEM/UKMET/ECMWF...USE OF 850MB TEMPS AND 1000-850MB THICKNESS DOES
NOT CLARIFY OR ADD ANY CERTAINTY TO THE PTYPE FCST. OF THOSE
MODELS...THE REGIONAL GEM IS QUITE WARM IN THE LOW-LEVELS AS IT HAS
1000-850MB THICKNESS RISING ABOVE 1300M TONIGHT ACROSS NEARLY THE
ENTIRE FCST AREA AND AS HIGH AS 1320M ACROSS THE SCNTRL/SE FCST
AREA. IF CORRECT...PCPN WOULD CHANGE TO MOSTLY RA/FZRA OVER MUCH OF
THE AREA. AT THIS POINT...WILL INCLUDE MIXED PTYPES ROUGHLY SE OF A
MARQUETTE TO CRYSTAL FALLS LINE. IT MAY BE ONE OF THOSE EVENTS WHERE
PCPN IS MOSTLY SNOW DURING PERIOD OF STRONGEST FORCING/HEAVIEST
PCPN AND THEN MORE OF A MIX OR A TRANSITION TO LIQUID PTYPES DURING
PERIODS OF LIGHT PCPN.
MIXING RATIOS SOLIDLY AROUND 4G/KG ON THE 295K SFC AND ABOUT 6 HRS
OF STRONG ISENTROPIC ASCENT SUGGEST POTENTIAL FOR AROUND 4 INCHES OF
SNOW WHERE PTYPE IS EXCLUSIVELY SNOW. THE SNOW WILL BE WET/HVY DUE
TO A NARROW AND HIGH DGZ (SNOW-TO-WATER WILL PROBABLY BE DOWN AROUND
10 TO 1). STRONGER DEEP LAYER FORCING PER QVECTORS WILL PASS ACROSS
THE NW FCST AREA...SO TOTALS THERE MAY BE HIGHER. IN FACT OVER THE
NW...SNOW AMOUNTS WILL BE CLOSE TO THE WARNING CRITERIA OF 6
INCHES/12HR FOR LOW SNOW TO WATER RATIO SNOW. LATER SHIFTS WILL NEED
TO MONITOR FOR POSSIBLE UPGRADE OF ADVY TO WARNING ACROSS THE
KEWEENAW IN PARTICULAR. AFTER THE PERIOD OF STRONG ISENTROPIC ASCENT
QUICKLY EXITS THIS EVENING...PCPN COVERAGE OVERNIGHT IS MUCH MORE
UNCERTAIN WITH NO COHERENT FORCING. IN ANY EVENT...THE PCPN SHOULD
BE MUCH LIGHTER IN THE WAKE OF THE MAIN BAND OF PCPN EXITING TO THE
N AND E THIS EVENING.
WITH THIS FCST ISSUANCE...OPTED TO INCLUDE THE REMAINDER OF THE FCST
AREA (ALGER/DELTA/MENOMINEE COUNTIES EASTWARD) IN A WINTER WX ADVY
LATE THIS AFTN/TONIGHT GIVEN THE EXPECTED MIXED PCPN AND 1-3 INCHES
OF HVY/WET SNOW IN THAT AREA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 436 AM EST SUN FEB 10 2013
AREA WILL BE IN THE MIDDLE OF THE SYSTEM PRODUCING A VARIETY OF
WINTER PRECIPITATION TYPES. AT 12Z ON MONDAY...THE LOW SHOULD BE
CENTERED OVER SOUTH CENTRAL UPPER MICHIGAN AND SHIFTING TO THE
EAST-NORTHEAST THROUGH THE DAY. UPPER LEVEL DRY SLOT WILL BE EAST OF
THE CWA AT THE START OF THE PERIOD AND WITH THE NEARLY VERTICALLY
STACKED LOW OVER THE SOUTH CENTRAL CWA...EXPECT THE HEAVIEST
PRECIPITATION TO BE JUST TO THE NORTHWEST OF THE LOW CENTER...FROM
THE KEWEENAW THROUGH GOGEBIC COUNTY WHERE THE LOWER LEVEL NOSE OF
LINGERING WARM AIR WRAPPING NW AROUND THE LOW. MEANWHILE...THE REST
OF THE AREA WILL BE SEEING LIGHT PRECIPITATION. THINK THERE WILL BE
ENOUGH WARM AIR ON THE EAST SIDE OF THE LOW TO KEEP SOME MIXED
PRECIPITATION GOING OVER EASTERN UPPER MICHIGAN DURING THE MORNING.
AS THE LOW SHIFTS TO THE EAST AND COLDER AIR SURGES SOUTH IN THE
AFTERNOON...SHOULD SEE A FAIRLY QUICK TRANSITION TO ALL SNOW FROM
THE RAIN/FREEZING RAIN MIX.
WITH THAT COLDER AIR MOVING IN...EXPECT A TRANSITION TO LAKE
ENHANCED SNOW ON MONDAY. EXPECT IT TO OCCUR IN THE NORTH WIND
FAVORED LOCATIONS DURING THE LATE MORNING OVER THE WEST AND THEN
OVER THE EAST IN THE AFTERNOON. WITH MUCH OF THE CLOUD AT THE BOTTOM
OR BELOW THE DGZ FOR MUCH OF MONDAY...DON/T THINK THE SNOW RATIOS
WILL COME UP MUCH FROM THE 10-12 TO 1 RANGE UNTIL LATER IN THE
AFTERNOON WHEN COLDER AIR ARRIVES. ANOTHER 2-4 INCHES IN THE FAVORED
LOCATIONS OUT WEST SEEMS REASONABLE FOR MONDAY...WITH A DUSTING TO 2
INCHES IN OTHER LOCATIONS. AS FOR WINDS...THE TRACK OF THE LOW
SHOULD LIMIT THE AMOUNT OF ENHANCEMENT FROM THE PRESSURE RISE/FALL
COUPLET SINCE THE WINDS WILL BE PERPENDICULAR TO IT. THAT BEING
SAID...NORTHERLY WINDS SHOULD BE ON THE INCREASE THROUGH THE DAY
FROM WEST TO EAST AS COLDER AIR INCREASES THE LOW LEVEL LAPSE RATES.
THINK THE HIGHEST GUSTS WILL BE RIGHT ALONG THE LAKE SUPERIOR
SHORELINE AND WILL PROBABLY SEE A COUPLE HOUR PERIOD OF GUSTS IN THE
30-35MPH RANGE.
MONDAY NIGHT INTO TUESDAY...H900 TEMPS AROUND -13C WILL BE ENOUGH TO
HOLD ONTO LAKE ENHANCED/EFFECT SNOW INTO MONDAY EVENING. BUT...THE
APPROACHING HIGH PRESSURE RIDGE WILL BE INCREASING THE DRY AIR AND
SUBSIDENCE THROUGH THE NIGHT AND LOWER INVERSION HEIGHTS. IN
ADDITION...EXPECT WARMER AIR TO ALSO MOVE SOUTHEAST INTO THE AREA
AND REDUCE THE LAKE INSTABILITY. THUS...EXPECT THE INTENSITY OF THE
SNOW TO DIMINISH THROUGH THE NIGHT WITH JUST LINGERING LIGHT SNOW
SHOWERS BY TUESDAY MORNING IN THE FAVORED NORTHWEST WIND SNOW
BELTS. CLOUDS WILL BE ON THE DECREASE THROUGH TUESDAY AFTERNOON WITH
THE SURFACE RIDGE STARTING TO SHIFT TO THE EAST AND LOWER LEVEL
WINDS BACKING TO THE WEST-SOUTHWEST. THIS IS IN RESPONSE TO THE NEXT
SURFACE TROUGH THAT WILL BE CROSSING THE AREA TUESDAY NIGHT INTO
WEDNESDAY MORNING AS THE MORE DOMINATE SOUTHERN STREAM JET REMAINS
OVER THE SOUTHERN THIRD OF THE CONUS. BEST MOISTURE/FORCING WITH
THIS TROUGH AND SHORTWAVE LOOK TO STAY OVER THE NORTHEAST HALF OF
LAKE SUPERIOR...BUT MAY BRUSH THE KEWEENAW AND FROM MARQUETTE TO
NEWBERRY ON WEDNESDAY.
EXTENDED RANGE MODELS BEGIN TO DIVERGE AFTER THIS POINT...AS A
NORTHERN STREAM WAVE DIVES SOUTHEAST OUT OF ALBERTA AND INTO THE
NORTHERN PLAINS ON WEDNESDAY. THIS WAVE CONTINUES TO DRIVE TO THE
SOUTHEAST AND TRIES TO MERGE/PHASE WITH THE STRONGER SOUTHERN
STREAM. 00Z GFS IS ON THE FARTHER NORTH AND LESS PHASED
SOLUTION...WHILE THE 12Z ECMWF IS THE FARTHEST SOUTHEAST AND THE 12Z
GEM IS IN BETWEEN. 00Z GEM/ECMWF DID TREND CLOSER TO THE GFS
SOLUTION...SO WILL FOLLOW A GENERALLY BLEND AND HAVE THE ASSOCIATED
SURFACE LOW TRACK THROUGH WISCONSIN. WOULD EXPECT SOME SHOWERS TO BE
AFFECTING THE AREA ON THURSDAY AND WILL CONTINUE MENTION OF
CHANCE/SLIGHT POPS. AFTER THURSDAY...GFS/GEM WRAP THE LOW UP AND
HAVE IT SLOWLY DEPART THE GREAT LAKES REGION THROUGH FRIDAY
NIGHT...WHILE THE ECMWF QUICKLY SLIDES IT EAST. WILL SPLIT THE
DIFFERENCE AND HIGHLIGHT CHANCE POPS FOR MUCH OF THE AREA AND
ESPECIALLY OVER THE LAKE EFFECT REGIONS SINCE THERE WILL BE A
NORTHERLY COMPONENT TO THE WINDS AS H850 TEMPS FALL TO 14C ON
FRIDAY. HIGH PRESSURE RIDGE WILL THEN TRY TO MOVE IN FOR FRIDAY
NIGHT INTO SATURDAY AND HAVE GRADUALLY DIMINISHED THE LAKE EFFECT
POPS.
AFTER THE ABOVE NORMAL TEMPERATURES THROUGH WED/THURS...EXPECT A
TRANSITION BACK TO MORE NORMAL TEMPERATURES FOR FRIDAY AND INTO THE
FIRST PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 641 AM EST SUN FEB 10 2013
AT KIWD...IFR CIGS SHOULD RISE SLIGHTLY TO LOW MVFR THIS MORNING AS
DOWNSLOPING E-SE WINDS STRENGTHEN. AT KCMX...EXPECT LOW MVFR CIGS TO
PREVAIL INTO THE AFTN. ALTHOUGH UPSLOPING S-SE WINDS SHOULD WORK TO
MAINTAIN IFR CIGS AT KSAW INTO THE AFTN...SOMEWHAT DRIER AIR WORKING
INTO THE AREA MAY ALLOW CIGS TO RISE TO LOW MVFR. THIS AFTN...
ATTENTION SHIFTS TO LOW PRES ADVANCING NE FROM THE CNTRL PLAINS.
BAND OF PCPN...POSSIBLY MDT/HVY...WILL SWING NE...AFFECTING ALL
TERMINALS FOR SEVERAL HRS DURING THE LATE AFTN/EARLY EVENING. PCPN
SHOULD BE IN THE FORM OF SNOW...BUT SOME PL IS POSSIBLE AT KSAW.
LIFR CONDITIONS ARE LIKELY TO PREVAIL AS THIS MAIN BAND OF PCPN
LIFTS THRU THE AREA. LATER EVENING/OVERNIGHT...LIGHTER AND PROBABLY
MORE INTERMITTENT PCPN IS EXPECTED THOUGH CONDITIONS WILL LIKELY
REMAIN IFR/LIFR. SOME -FZDZ/-FZRA MAY OCCUR AT KSAW DURING THE
NIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 436 AM EST SUN FEB 10 2013
A LOW PRESSURE SYSTEM EXITING THE CENTRAL PLAINS WILL MOVE INTO THE
UPPER GREAT LAKES REGION LATE TONIGHT AND THEN SHIFT EAST ON MONDAY
AFTERNOON. THIS WILL LEAD TO INCREASING EAST-NORTHEAST FLOW OVER
WESTERN LAKE SUPERIOR AND EXPECT GALES TO 40KTS THIS AFTERNOON AND
EVENING. THUS...HAVE ISSUED A GALE WARNING FOR LSZ162/263. THEN AS
THE WINDS TURN TO THE NORTH TONIGHT...EXPECT GALES TO 35-40KTS OVER
THE WEST AND NORTH CENTRAL LAKE THROUGH MONDAY. THERE MAY BE GALES
OVER THE EASTERN LAKE MONDAY AFTERNOON...BUT CONFIDENCE WASN/T HIGH
ENOUGH TO ISSUE A GALE WARNING. A HIGH PRESSURE RIDGE WILL DIMINISH
THE WINDS MONDAY NIGHT INTO TUESDAY.
A SURFACE TROUGH WILL MOVE ACROSS LAKE SUPERIOR TUESDAY NIGHT AND
WEDNESDAY...SHIFTING WINDS TO THE WEST BUT KEEPING THEM BELOW
20KTS. A WEAK LOW PRESSURE SYSTEM WILL THEN MOVE OUT OF THE DAKOTAS
ON WEDNESDAY NIGHT AND INTO WISCONSIN ON THURSDAY.
FREEZING SPRAY IS EXPECTED MONDAY AND MONDAY NIGHT OVER MUCH OF
LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ THIS AFTERNOON
TO 7 AM EST /6 AM CST/ MONDAY FOR MIZ006-007-012>014-085.
WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ THIS AFTERNOON
TO 7 AM EST /6 AM CST/ TUESDAY FOR MIZ002-009.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST
MONDAY FOR MIZ001-003>005-084.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM CST
MONDAY FOR MIZ010-011.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM EST /2 PM CST/ THIS AFTERNOON TO 10 AM
EST /9 AM CST/ MONDAY FOR LSZ162.
GALE WARNING FROM 7 AM TO 7 PM EST MONDAY FOR LSZ264.
GALE WARNING FROM 3 PM THIS AFTERNOON TO 4 PM EST MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
544 AM EST SUN FEB 10 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 543 AM EST SUN FEB 10 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED MID LEVEL
LOW LIFTING OUT OVER THE WRN PLAINS...AND 00Z RAOBS AND SFC OBS
INDICATE THAT SYSTEM HAS DEVELOPED A GOOD GULF MOISTURE CONNECTION.
THE MID LEVEL LOW WILL TRACK NE...REACHING THE UPPER LAKES MON
MORNING. ALTHOUGH MODELS ARE IN GOOD AGREEMENT ON THE TRACK OF THE
MID LEVEL LOW AND ASSOCIATED SFC LOW...FCST REMAINS A CHALLENGE
WITH RESPECT TO PTYPES AS EVAPORATIVE AND THEN DYNAMIC COOLING
BATTLE STRONG WAA. WITH THE STRONG WAA REGIME TAPPING A SOLID GULF
MOISTURE FEED...PRECIPITABLE WATER SURGES TO 250-300PCT OF NORMAL IN
THE UPPER LAKES...PROVIDING POTENTIAL FOR HVY PCPN. HOWEVER...
HEAVIEST PCPN WILL BE SHORT-LIVED (ABOUT 4-6HRS) ON THE FRONT SIDE
OF THE SYSTEM AS STRONG ISENTROPIC ASCENT RAPIDLY SHIFTS ACROSS THE
AREA PER 295K SFC WHICH SHOWS 40-50KT WINDS PERPENDICULAR TO
ISOBARS. ALTHOUGH THERE IS ABUNDANT AVBL MOISTURE...QUICK MOVEMENT
OF THIS VIGOROUS ASCENT WILL HELP KEEP PCPN TOTALS IN CHECK. NARROW
MIDLEVEL DRY SLOT PUNCHING N COULD LEAD TO SOME CONVECTIVE PCPN ON
TAIL END OF THE ISENTROPIC ASCENT/MAIN PCPN BAND THIS EVENING
(MODELS ALSO SHOW SHOWALTER INDEX FALLING CLOSE TO 0C). AS FOR
PTYPE...IT REMAINS A TOUGH CALL. FCST SOUNDINGS FROM THE NAM/GFS
SHOW TEMP PROFILE HOVERING NEAR 0C THRU A RATHER SUBSTANTIAL
LOW-LEVEL DEPTH...AND THE NAM IN PARTICULAR SHOWS SURGES OF ABOVE 0C
TEMPS AT TIMES...SUGGESTING EPISODES OF VARYING PTYPES. WITH HIGH
RES TEMP PROFILE INFO NOT AVBL FOR THE UKMET/REGIONAL
GEM/UKMET/ECMWF...USE OF 850MB TEMPS AND 1000-850MB THICKNESS DOES
NOT CLARIFY OR ADD ANY CERTAINTY TO THE PTYPE FCST. OF THOSE
MODELS...THE REGIONAL GEM IS QUITE WARM IN THE LOW-LEVELS AS IT HAS
1000-850MB THICKNESS RISING ABOVE 1300M TONIGHT ACROSS NEARLY THE
ENTIRE FCST AREA AND AS HIGH AS 1320M ACROSS THE SCNTRL/SE FCST
AREA. IF CORRECT...PCPN WOULD CHANGE TO MOSTLY RA/FZRA OVER MUCH OF
THE AREA. AT THIS POINT...WILL INCLUDE MIXED PTYPES ROUGHLY SE OF A
MARQUETTE TO CRYSTAL FALLS LINE. IT MAY BE ONE OF THOSE EVENTS WHERE
PCPN IS MOSTLY SNOW DURING PERIOD OF STRONGEST FORCING/HEAVIEST
PCPN AND THEN MORE OF A MIX OR A TRANSITION TO LIQUID PTYPES DURING
PERIODS OF LIGHT PCPN.
MIXING RATIOS SOLIDLY AROUND 4G/KG ON THE 295K SFC AND ABOUT 6 HRS
OF STRONG ISENTROPIC ASCENT SUGGEST POTENTIAL FOR AROUND 4 INCHES OF
SNOW WHERE PTYPE IS EXCLUSIVELY SNOW. THE SNOW WILL BE WET/HVY DUE
TO A NARROW AND HIGH DGZ (SNOW-TO-WATER WILL PROBABLY BE DOWN AROUND
10 TO 1). STRONGER DEEP LAYER FORCING PER QVECTORS WILL PASS ACROSS
THE NW FCST AREA...SO TOTALS THERE MAY BE HIGHER. IN FACT OVER THE
NW...SNOW AMOUNTS WILL BE CLOSE TO THE WARNING CRITERIA OF 6
INCHES/12HR FOR LOW SNOW TO WATER RATIO SNOW. LATER SHIFTS WILL NEED
TO MONITOR FOR POSSIBLE UPGRADE OF ADVY TO WARNING ACROSS THE
KEWEENAW IN PARTICULAR. AFTER THE PERIOD OF STRONG ISENTROPIC ASCENT
QUICKLY EXITS THIS EVENING...PCPN COVERAGE OVERNIGHT IS MUCH MORE
UNCERTAIN WITH NO COHERENT FORCING. IN ANY EVENT...THE PCPN SHOULD
BE MUCH LIGHTER IN THE WAKE OF THE MAIN BAND OF PCPN EXITING TO THE
N AND E THIS EVENING.
WITH THIS FCST ISSUANCE...OPTED TO INCLUDE THE REMAINDER OF THE FCST
AREA (ALGER/DELTA/MENOMINEE COUNTIES EASTWARD) IN A WINTER WX ADVY
LATE THIS AFTN/TONIGHT GIVEN THE EXPECTED MIXED PCPN AND 1-3 INCHES
OF HVY/WET SNOW IN THAT AREA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 436 AM EST SUN FEB 10 2013
AREA WILL BE IN THE MIDDLE OF THE SYSTEM PRODUCING A VARIETY OF
WINTER PRECIPITATION TYPES. AT 12Z ON MONDAY...THE LOW SHOULD BE
CENTERED OVER SOUTH CENTRAL UPPER MICHIGAN AND SHIFTING TO THE
EAST-NORTHEAST THROUGH THE DAY. UPPER LEVEL DRY SLOT WILL BE EAST OF
THE CWA AT THE START OF THE PERIOD AND WITH THE NEARLY VERTICALLY
STACKED LOW OVER THE SOUTH CENTRAL CWA...EXPECT THE HEAVIEST
PRECIPITATION TO BE JUST TO THE NORTHWEST OF THE LOW CENTER...FROM
THE KEWEENAW THROUGH GOGEBIC COUNTY WHERE THE LOWER LEVEL NOSE OF
LINGERING WARM AIR WRAPPING NW AROUND THE LOW. MEANWHILE...THE REST
OF THE AREA WILL BE SEEING LIGHT PRECIPITATION. THINK THERE WILL BE
ENOUGH WARM AIR ON THE EAST SIDE OF THE LOW TO KEEP SOME MIXED
PRECIPITATION GOING OVER EASTERN UPPER MICHIGAN DURING THE MORNING.
AS THE LOW SHIFTS TO THE EAST AND COLDER AIR SURGES SOUTH IN THE
AFTERNOON...SHOULD SEE A FAIRLY QUICK TRANSITION TO ALL SNOW FROM
THE RAIN/FREEZING RAIN MIX.
WITH THAT COLDER AIR MOVING IN...EXPECT A TRANSITION TO LAKE
ENHANCED SNOW ON MONDAY. EXPECT IT TO OCCUR IN THE NORTH WIND
FAVORED LOCATIONS DURING THE LATE MORNING OVER THE WEST AND THEN
OVER THE EAST IN THE AFTERNOON. WITH MUCH OF THE CLOUD AT THE BOTTOM
OR BELOW THE DGZ FOR MUCH OF MONDAY...DON/T THINK THE SNOW RATIOS
WILL COME UP MUCH FROM THE 10-12 TO 1 RANGE UNTIL LATER IN THE
AFTERNOON WHEN COLDER AIR ARRIVES. ANOTHER 2-4 INCHES IN THE FAVORED
LOCATIONS OUT WEST SEEMS REASONABLE FOR MONDAY...WITH A DUSTING TO 2
INCHES IN OTHER LOCATIONS. AS FOR WINDS...THE TRACK OF THE LOW
SHOULD LIMIT THE AMOUNT OF ENHANCEMENT FROM THE PRESSURE RISE/FALL
COUPLET SINCE THE WINDS WILL BE PERPENDICULAR TO IT. THAT BEING
SAID...NORTHERLY WINDS SHOULD BE ON THE INCREASE THROUGH THE DAY
FROM WEST TO EAST AS COLDER AIR INCREASES THE LOW LEVEL LAPSE RATES.
THINK THE HIGHEST GUSTS WILL BE RIGHT ALONG THE LAKE SUPERIOR
SHORELINE AND WILL PROBABLY SEE A COUPLE HOUR PERIOD OF GUSTS IN THE
30-35MPH RANGE.
MONDAY NIGHT INTO TUESDAY...H900 TEMPS AROUND -13C WILL BE ENOUGH TO
HOLD ONTO LAKE ENHANCED/EFFECT SNOW INTO MONDAY EVENING. BUT...THE
APPROACHING HIGH PRESSURE RIDGE WILL BE INCREASING THE DRY AIR AND
SUBSIDENCE THROUGH THE NIGHT AND LOWER INVERSION HEIGHTS. IN
ADDITION...EXPECT WARMER AIR TO ALSO MOVE SOUTHEAST INTO THE AREA
AND REDUCE THE LAKE INSTABILITY. THUS...EXPECT THE INTENSITY OF THE
SNOW TO DIMINISH THROUGH THE NIGHT WITH JUST LINGERING LIGHT SNOW
SHOWERS BY TUESDAY MORNING IN THE FAVORED NORTHWEST WIND SNOW
BELTS. CLOUDS WILL BE ON THE DECREASE THROUGH TUESDAY AFTERNOON WITH
THE SURFACE RIDGE STARTING TO SHIFT TO THE EAST AND LOWER LEVEL
WINDS BACKING TO THE WEST-SOUTHWEST. THIS IS IN RESPONSE TO THE NEXT
SURFACE TROUGH THAT WILL BE CROSSING THE AREA TUESDAY NIGHT INTO
WEDNESDAY MORNING AS THE MORE DOMINATE SOUTHERN STREAM JET REMAINS
OVER THE SOUTHERN THIRD OF THE CONUS. BEST MOISTURE/FORCING WITH
THIS TROUGH AND SHORTWAVE LOOK TO STAY OVER THE NORTHEAST HALF OF
LAKE SUPERIOR...BUT MAY BRUSH THE KEWEENAW AND FROM MARQUETTE TO
NEWBERRY ON WEDNESDAY.
EXTENDED RANGE MODELS BEGIN TO DIVERGE AFTER THIS POINT...AS A
NORTHERN STREAM WAVE DIVES SOUTHEAST OUT OF ALBERTA AND INTO THE
NORTHERN PLAINS ON WEDNESDAY. THIS WAVE CONTINUES TO DRIVE TO THE
SOUTHEAST AND TRIES TO MERGE/PHASE WITH THE STRONGER SOUTHERN
STREAM. 00Z GFS IS ON THE FARTHER NORTH AND LESS PHASED
SOLUTION...WHILE THE 12Z ECMWF IS THE FARTHEST SOUTHEAST AND THE 12Z
GEM IS IN BETWEEN. 00Z GEM/ECMWF DID TREND CLOSER TO THE GFS
SOLUTION...SO WILL FOLLOW A GENERALLY BLEND AND HAVE THE ASSOCIATED
SURFACE LOW TRACK THROUGH WISCONSIN. WOULD EXPECT SOME SHOWERS TO BE
AFFECTING THE AREA ON THURSDAY AND WILL CONTINUE MENTION OF
CHANCE/SLIGHT POPS. AFTER THURSDAY...GFS/GEM WRAP THE LOW UP AND
HAVE IT SLOWLY DEPART THE GREAT LAKES REGION THROUGH FRIDAY
NIGHT...WHILE THE ECMWF QUICKLY SLIDES IT EAST. WILL SPLIT THE
DIFFERENCE AND HIGHLIGHT CHANCE POPS FOR MUCH OF THE AREA AND
ESPECIALLY OVER THE LAKE EFFECT REGIONS SINCE THERE WILL BE A
NORTHERLY COMPONENT TO THE WINDS AS H850 TEMPS FALL TO 14C ON
FRIDAY. HIGH PRESSURE RIDGE WILL THEN TRY TO MOVE IN FOR FRIDAY
NIGHT INTO SATURDAY AND HAVE GRADUALLY DIMINISHED THE LAKE EFFECT
POPS.
AFTER THE ABOVE NORMAL TEMPERATURES THROUGH WED/THURS...EXPECT A
TRANSITION BACK TO MORE NORMAL TEMPERATURES FOR FRIDAY AND INTO THE
FIRST PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1209 AM EST SUN FEB 10 2013
LOWER END MVFR CIGS ARE EXPECTED OVERNIGHT AS LOW LEVEL MOISTURE
CONTINUES TO MOVE INTO THE REGION ON SRLY FLOW. A MORE SSE TRAJECTORY
LATE IN THE NIGHT AT SAW SHOULD HELP LOWER CIGS INTO THE IFR RANGE
ALONG WITH MVFR VSBY IN BR. DOWNSLOPE FLOW AT IWD AND CMX WILL HELP
KEEP CIGS FROM DROPPING OFF AS MUCH. BY MID TO LATE AFTERNOON...SNOW
MIXED WITH SLEET IS EXPECTED TO SPREAD NE INTO UPPER MI DROPPING
BOTH CIG AND VSBY INTO THE IFR RANGE. THERE IS ALSO A POTENTIAL FOR
SOME FREEZING RAIN BUT THE PROBABILITY WAS LOW ENOUGH TO LEAVE OUT
MENTION IN THE TAF AT THIS TIME. A PERIOD OF HEAVIER PCPN...MAINLY
SNOW...IS LIKELY TO HELP LOWER CIGS INTO THE LIFR RANGE DURING THE
EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 436 AM EST SUN FEB 10 2013
A LOW PRESSURE SYSTEM EXITING THE CENTRAL PLAINS WILL MOVE INTO THE
UPPER GREAT LAKES REGION LATE TONIGHT AND THEN SHIFT EAST ON MONDAY
AFTERNOON. THIS WILL LEAD TO INCREASING EAST-NORTHEAST FLOW OVER
WESTERN LAKE SUPERIOR AND EXPECT GALES TO 40KTS THIS AFTERNOON AND
EVENING. THUS...HAVE ISSUED A GALE WARNING FOR LSZ162/263. THEN AS
THE WINDS TURN TO THE NORTH TONIGHT...EXPECT GALES TO 35-40KTS OVER
THE WEST AND NORTH CENTRAL LAKE THROUGH MONDAY. THERE MAY BE GALES
OVER THE EASTERN LAKE MONDAY AFTERNOON...BUT CONFIDENCE WASN/T HIGH
ENOUGH TO ISSUE A GALE WARNING. A HIGH PRESSURE RIDGE WILL DIMINISH
THE WINDS MONDAY NIGHT INTO TUESDAY.
A SURFACE TROUGH WILL MOVE ACROSS LAKE SUPERIOR TUESDAY NIGHT AND
WEDNESDAY...SHIFTING WINDS TO THE WEST BUT KEEPING THEM BELOW
20KTS. A WEAK LOW PRESSURE SYSTEM WILL THEN MOVE OUT OF THE DAKOTAS
ON WEDNESDAY NIGHT AND INTO WISCONSIN ON THURSDAY.
FREEZING SPRAY IS EXPECTED MONDAY AND MONDAY NIGHT OVER MUCH OF
LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ THIS AFTERNOON
TO 7 AM EST /6 AM CST/ MONDAY FOR MIZ006-007-012>014-085.
WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ THIS AFTERNOON
TO 7 AM EST /6 AM CST/ TUESDAY FOR MIZ002-009.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST
MONDAY FOR MIZ001-003>005-084.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM CST
MONDAY FOR MIZ010-011.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM EST /2 PM CST/ THIS AFTERNOON TO 10 AM
EST /9 AM CST/ MONDAY FOR LSZ162.
GALE WARNING FROM 7 AM TO 7 PM EST MONDAY FOR LSZ264.
GALE WARNING FROM 3 PM THIS AFTERNOON TO 4 PM EST MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
619 AM CST SUN FEB 10 2013
.UPDATE...UPDATED AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION.../ISSUED AT 430 AM CST SUN FEB 10 2013/
THE POWERFUL STORM WILL BRING WINTER WEATHER ACROSS THE REGION
TODAY...WITH A BAND OF HEAVY SNOW WITH CONVECTIVE ELEMENTS
EXPECTED TO DEVELOP THIS MORNING AND TRAVERSE THE REGION AS IT
MOVES NORTHWARD TOWARDS LAKES SUPERIOR. SNOW WILL CONTINUE ACROSS
THE WEST THROUGHOUT THE DAY...BUT THE REST OF THE REGION SHOULD
SEE A BREAK DURING THE AFTERNOON HOURS. SOME ADDITIONAL SNOW IS
EXPECTED OVERNIGHT...WITH BLIZZARD CONDITIONS DEVELOPING LATER
TONIGHT ACROSS THE MINNESOTA RIVER VALLEY. LOOKING AHEAD...COOLER
WEATHER WILL SETTLE IN FOR THE UPCOMING WEEK...WITH NO SIGNIFICANT
PRECIPITATION EXPECTED.
TODAY THROUGH MONDAY...AS OF EARLY THIS MORNING...THE WELL
ADVERTISED WINTER STORM WAS TAKING SHAPE ACROSS THE CENTRAL CONUS. IR
IMAGERY TOGETHER WITH RAP13 SURFACE ANALYSIS PLACED THE SURFACE LOW
ACROSS SOUTH CENTRAL NEBRASKA...WITH THREE DISTINCT AREAS OF COLD
CLOUD TOPS FANNING OUT ACROSS THE UPPER MIDWEST. OVER THE NEXT 12
HOURS...ISENTROPIC LIFT WILL INCREASE ACROSS THE CWA...WITH A
FRONTOGENETIC CIRCULATION IN THE H700-500 LAYER AIDING IN THE
ASCENT. A CROSS SECTION FROM OMAHA THROUGH DULUTH DEPICT THIS
VERTICAL MOTION. PERHAPS MOST IMPORTANTLY THE CROSS SECTION ALSO
SHOWS UPRIGHT INSTABILITY VIA THE THETA_E LINES WITHIN THIS LAYER
ON THE LEADING EDGE OF THE DRY SLOT. THIS IS A TEXTBOOK SETUP FOR
THUNDERSNOW...AND THIS ELEVATED INSTABILITY IS CONFIRMED BY
ELEVATED CAPE VALUES OF 50 TO 100J/KG VIA THE SREF/NAM/GFS BUFR
SOUNDINGS AT KFRM/KRWF/KMSP/KEAU. THEREFORE DESPITE THE ABSENCE OF
A DEEP COLD LAYER...INCLUDED SLEET IN THE GRIDS TO TARGET THE
POSSIBILITY OF SOME GRAUPEL WITH THE CONVECTIVE ELEMENTS. THE LAST
FEW RUNS OF THE HRRR HAVE A GOOD HANDLE ON THE RAPID DEVELOPMENT
OF AN AREA OF PRECIP THAT IS NOW LOCATED OVER EASTERN NEBRASKA.
TRIED TO TIME THIS BAND OF HEAVY SNOW IN THE HOURLY WEATHER GRIDS.
IT SHOULD ARRIVE AT FAIRMONT BY 11/12Z...AND REACH THE METRO AREA
AND ST CLOUD AROUND 15/16Z...AND IMPACT RICE LAKE/EAU CLAIRE
AROUND 16/17Z. FURTHER WEST MODERATE TO HEAVY SNOW IS EXPECTED
MOST OF THE DAY AS A TROWEL...SEEN IN THE H500-700
THICKNESS...DEVELOPS ACROSS CENTRAL MINNESOTA. AS THE CYCLONE
CONTINUES TO OCCLUDE...THE MEDIUM RANGE AND HIRES MODELS ALL
DEVELOP A SECOND AREA OF PRECIP AHEAD OF THE H500MB VORT MAX
SUNDAY EVENING THAT LAGS THE SURFACE LOW AND TRACKS FROM ROUGHLY
ALBERT LEA...THROUGH RED WING...AND LADYSMITH. THIS WILL DROP
ADDITIONAL SNOW FALL ACROSS SOUTHERN MINNESOTA...WHICH COULD SET
THE STAGE FOR BLIZZARD CONDITIONS EXTENDING AS FAR SOUTH AS I-90
SUNDAY NIGHT THROUGH MONDAY. BUFR FORECAST SOUNDINGS AT FAIRMONT
FROM BOTH THE GFS AND NAM SHOW DIFFERENTIAL COLD AIR ADVECTION
DESTABILIZING THE BOUNDARY LAYER SUNDAY NIGHT...WITH WINDS OF 40
TO 45KTS ATOP THE MIXED LAYER...AS WELL AS SATURATION AND WEAK
LIFT WITHIN THE DEEP DENDRITIC ZONE. IF THE SNOWFALL FORECAST PANS
OUT ACROSS SOUTHERN MINNESOTA TODAY AND THE DITCHES ARE
FULL...THAN HAVE HIGH CONFIDENCE THAT THE BLIZZARD WARNING WILL
NEED TO BE EXTENDED SOUTH LASTING THROUGH MONDAY AFTERNOON. GIVEN
THE CURRENT COMPLEX HEADLINE SITUATION...HAVE OPTED TO JUST EXTEND
THE WINTER WEATHER ADVISORY OUT IN TIME THROUGH MONDAY AFTERNOON
SINCE THE BLIZZARD CONDITIONS WOULDN/T DEVELOP UNTIL SUNDAY NIGHT.
MONDAY NIGHT THROUGH FRIDAY...NORTHWEST FLOW WILL DEVELOP ACROSS THE
REGION WITH A SURFACE HIGH BUILDING OVER THE UPPER MIDWEST IN THE
WAKE OF THE STORM. LEE SIDE WARMING OVER THE CANADIAN PLAINS WILL
KEEP THE COLDEST AIR ACROSS HUDSON BAY. A CLIPPER SYSTEM WILL MOVE
ACROSS THE REGION MID WEEK AND BRING SOME LIGHT SNOW. POPS WILL
LIKELY HAVE TO BE ADJUSTED UP FOR THIS SYSTEM IF IT REMAINS ON
COURSE. ANOTHER SURGE OF ARCTIC AIR WILL FOLLOW BEHIND THIS
CLIPPER...WITH SUB ZERO LOW TEMPERATURES POSSIBLE BY THE END OF THE
WEEK.
&&
.AVIATION.../12Z TAF ISSUANCE/
THE WINTER STORM IS NOW UNDERWAY WITH ONE BATCH OF PRECIP PUSHING
THROUGH ALL THE TAF SITES EARLIER...WITH A MORE INTENSE ROUND NOW
DEVELOPING ACROSS SWRN MN AND WRN IA. THIS BATCH WILL BRING A
PERIOD OF HEAVY PRECIPITATION TO MUCH OF THE AREA LATE THIS
MORNING AND EARLY AFTERNOON. ISOLATED THUNDERSTORMS HAVE ALREADY BEEN
DEVELOPING WITHIN THIS BAND OVERNIGHT...AND THINK THAT TREND WILL
CONTINUE AS IT SWINGS THROUGH. IT SHOULD REMAIN MOSTLY SNOW NORTH
OF A LINE FROM KDXX...TO KMSP...AND KRNH. SOUTH OF THAT LINE A
WINTRY MIX IS EXPECTED. FOLLOWING THAT ROUND...OCCASIONAL LIGHT
SNOW OR PATCHY DRIZZLE WILL CONTINUE THROUGH THE REST OF THE TAF
PERIOD WITH THE STEADIEST AND HEAVIEST SNOW IMPACTING AXN...STC...
AND POSSIBLY RWF INTO MONDAY MORNING. THERE WILL BE ANOTHER AREA
WITH ENHANCED SNOWFALL FOR A FEW HOURS THIS EVENING JUST BEHIND
THE LOW ITSELF WHICH SHOULD BRING MODERATE SNOW FROM KFRM...TO
KRGX AND KEAU. KMSP AND KRNH MAY ALSO BE IMPACTED AND INDICATED
SO IN THE TAF.
BLIZZARD CONDITIONS WILL DEVELOP THIS EVENING AS WINDS STRENGTHEN.
GUSTS TO 35+ KTS APPEAR LIKELY WEST OF KAXN AND INCLUDING KRWF.
TOWARD THE END OF THE PERIOD...SOME OF THE STRONGER WINDS WILL
SPREAD TO THE EASTERN TAF SITES.
KMSP...FAIRLY HIGH CONFIDENCE IN A PERIOD OF HEAVY SNOW AND
VICINITY TS LATE THIS MORNING AS THE MAIN BAND OF PRECIPITATION
INTENSIFIES. SNOW RATES OF 1 TO 2 INCHES PER HOUR ARE PROBABLE.
AFTER 18 OR 19Z...OCCASIONAL LIGHT SNOW WILL CONTINUE UNTIL THE
LOW PASSES AT WHICH POINT ANOTHER BATCH OF HEAVIER SNOW COULD FALL
EARLY THIS EVENING. MOST OF THE MODELS KEEP IT JUST SOUTH OF THE
TERMINAL...BUT IT BEARS WATCHING.
/OUTLOOK FOR KMSP/
LATE MON...MVFR WITH -SN. NW WINDS 18G30KTS.
TUE...VFR. W WINDS 5 TO 10 KTS.
WED...VFR. MVFR WITH CHC -SN LATE. SW WINDS 5 TO 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST MONDAY FOR BLUE EARTH-
FARIBAULT-FREEBORN-LE SUEUR-MARTIN-RICE-SCOTT-STEELE-WASECA-
WATONWAN.
WINTER STORM WARNING UNTIL 9 PM CST THIS EVENING FOR BROWN-
CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-NICOLLET-POPE-
REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-YELLOW MEDICINE.
BLIZZARD WARNING FROM 9 PM THIS EVENING TO 6 PM CST MONDAY FOR
BROWN-CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-NICOLLET-
POPE-REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-YELLOW MEDICINE.
WINTER STORM WARNING UNTIL 6 PM CST MONDAY FOR CARVER-MCLEOD-
MEEKER-STEARNS-TODD-WRIGHT.
WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR ANOKA-BENTON-
CHISAGO-HENNEPIN-ISANTI-KANABEC-MILLE LACS-MORRISON-RAMSEY-
SHERBURNE-WASHINGTON.
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR DAKOTA-GOODHUE.
WI...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR CHIPPEWA-DUNN-
EAU CLAIRE-PEPIN-PIERCE.
WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR BARRON-POLK-RUSK-
ST. CROIX.
&&
$$
JRB/BORGHOFF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
430 AM CST SUN FEB 10 2013
.DISCUSSION...
THE POWERFUL STORM WILL BRING WINTER WEATHER ACROSS THE REGION
TODAY...WITH A BAND OF HEAVY SNOW WITH CONVECTIVE ELEMENTS EXPECTED
TO DEVELOP THIS MORNING AND TRAVERSE THE REGION AS IT MOVES
NORTHWARD TOWARDS LAKES SUPERIOR. SNOW WILL CONTINUE ACROSS THE
WEST THROUGHOUT THE DAY...BUT THE REST OF THE REGION SHOULD SEE A
BREAK DURING THE AFTERNOON HOURS. SOME ADDITIONAL SNOW IS EXPECTED
OVERNIGHT...WITH BLIZZARD CONDITIONS DEVELOPING LATER TONIGHT
ACROSS THE MINNESOTA RIVER VALLEY. LOOKING AHEAD...COOLER WEATHER
WILL SETTLE IN FOR THE UPCOMING WEEK...WITH NO SIGNIFICANT
PRECIPITATION EXPECTED.
TODAY THROUGH MONDAY...AS OF EARLY THIS MORNING...THE WELL
ADVERTISED WINTER STORM WAS TAKING SHAPE ACROSS THE CENTRAL CONUS. IR
IMAGERY TOGETHER WITH RAP13 SURFACE ANALYSIS PLACED THE SURFACE LOW
ACROSS SOUTH CENTRAL NEBRASKA...WITH THREE DISTINCT AREAS OF COLD
CLOUD TOPS FANNING OUT ACROSS THE UPPER MIDWEST. OVER THE NEXT 12
HOURS...ISENTROPIC LIFT WILL INCREASE ACROSS THE CWA...WITH A
FRONTOGENETIC CIRCULATION IN THE H700-500 LAYER AIDING IN THE
ASCENT. A CROSS SECTION FROM OMAHA THROUGH DULUTH DEPICT THIS
VERTICAL MOTION. PERHAPS MOST IMPORTANTLY THE CROSS SECTION ALSO
SHOWS UPRIGHT INSTABILITY VIA THE THETA_E LINES WITHIN THIS LAYER
ON THE LEADING EDGE OF THE DRY SLOT. THIS IS A TEXTBOOK SETUP FOR
THUNDERSNOW...AND THIS ELEVATED INSTABILITY IS CONFIRMED BY
ELEVATED CAPE VALUES OF 50 TO 100J/KG VIA THE SREF/NAM/GFS BUFR
SOUNDINGS AT KFRM/KRWF/KMSP/KEAU. THEREFORE DESPITE THE ABSENCE OF
A DEEP COLD LAYER...INCLUDED SLEET IN THE GRIDS TO TARGET THE
POSSIBILITY OF SOME GRAUPEL WITH THE CONVECTIVE ELEMENTS. THE LAST
FEW RUNS OF THE HRRR HAVE A GOOD HANDLE ON THE RAPID DEVELOPMENT
OF AN AREA OF PRECIP THAT IS NOW LOCATED OVER EASTERN NEBRASKA.
TRIED TO TIME THIS BAND OF HEAVY SNOW IN THE HOURLY WEATHER GRIDS.
IT SHOULD ARRIVE AT FAIRMONT BY 11/12Z...AND REACH THE METRO AREA
AND ST CLOUD AROUND 15/16Z...AND IMPACT RICE LAKE/EAU CLAIRE
AROUND 16/17Z. FURTHER WEST MODERATE TO HEAVY SNOW IS EXPECTED
MOST OF THE DAY AS A TROWEL...SEEN IN THE H500-700
THICKNESS...DEVELOPS ACROSS CENTRAL MINNESOTA. AS THE CYCLONE
CONTINUES TO OCCLUDE...THE MEDIUM RANGE AND HIRES MODELS ALL
DEVELOP A SECOND AREA OF PRECIP AHEAD OF THE H500MB VORT MAX
SUNDAY EVENING THAT LAGS THE SURFACE LOW AND TRACKS FROM ROUGHLY
ALBERT LEA...THROUGH REDWING...AND LADYSMITH. THIS WILL DROP
ADDITIONAL SNOW FALL ACROSS SOUTHERN MINNESOTA...WHICH COULD SET
THE STAGE FOR BLIZZARD CONDITIONS EXTENDING AS FAR SOUTH AS I-90
SUNDAY NIGHT THROUGH MONDAY. BUFR FORECAST SOUNDINGS AT FAIRMONT
FROM BOTH THE GFS AND NAM SHOW DIFFERENTIAL COLD AIR ADVECTION
DESTABILIZING THE BOUNDARY LAYER SUNDAY NIGHT...WITH WINDS OF 40
TO 45KTS ATOP THE MIXED LAYER...AS WELL AS SATURATION AND WEAK
LIFT WITHIN THE DEEP DENDRITIC ZONE. IF THE SNOWFALL FORECAST PANS
OUT ACROSS SOUTHERN MINNESOTA TODAY AND THE DITCHES ARE
FULL...THAN HAVE HIGH CONFIDENCE THAT THE BLIZZARD WARNING WILL
NEED TO BE EXTENDED SOUTH LASTING THROUGH MONDAY AFTERNOON. GIVEN
THE CURRENT COMPLEX HEADLINE SITUATION...HAVE OPTED TO JUST EXTEND
THE WINTER WEATHER ADVISORY OUT IN TIME THROUGH MONDAY AFTERNOON
SINCE THE BLIZZARD CONDITIONS WOULDNT DEVELOP UNTIL SUNDAY NIGHT.
MONDAY NIGHT THROUGH FRIDAY...NORTHWEST FLOW WILL DEVELOP ACROSS THE
REGION WITH A SURFACE HIGH BUILDING OVER THE UPPER MIDWEST IN THE
WAKE OF THE STORM. LEE SIDE WARMING OVER THE CANADIAN PLAINS WILL
KEEP THE COLDEST AIR ACROSS HUDSON BAY. A CLIPPER SYSTEM WILL MOVE
ACROSS THE REGION MID WEEK AND BRING SOME LIGHT SNOW. POPS WILL
LIKELY HAVE TO BE ADJUSTED UP FOR THIS SYSTEM IF IT REMAINS ON
COURSE. ANOTHER SURGE OF ARCTIC AIR WILL FOLLOW BEHIND THIS
CLIPPER...WITH SUB ZERO LOW TEMPERATURES POSSIBLE BY THE END OF THE
WEEK.
&&
.AVIATION... /06Z TAF ISSUANCE/
THE FIRST BAND OF LIGHT PRECIPITATION IS NEARING KAXN AND KRWF AT TAF
ISSUANCE. MAINLY SNOW IS EXPECTED OVERNIGHT BUT SOME LIGHT FREEZING
RAIN AND SLEET CAN NOT BE RULED OUT. THE TREND WILL BE FOR SEVERAL
BANDS OF LIGHT PRECIPITATION TO MOVE THROUGH OVERNIGHT BEFORE A
MORE PRONOUNCED AREA OF MODERATE TO HEAVY SNOW DEVELOPS IN THE
MORNING AND LASTS THROUGH THE DAY. KSTC WILL ALSO SEE INTERMITTENT
LIGHT SNOW OVERNIGHT ALONG WITH SOME BOUTS OF FREEZING DRIZZLE IN
BETWEEN. BEST CHANCE FOR MODERATE TO HEAVY SNOW AT KSTC IS FROM
LATE MORNING THROUGH THE EARLY AFTERNOON HOURS. KMSP...KRNH AND
KEAU ARE MORE PROBLEMATIC ON PRECIPITATION TYPE AS SOME LOW LEVEL
WARM AIR MAY RESULT IN A MIX OF LIGHT SNOW AND FREEZING RAIN
DURING THE LATE NIGHT AND EARLY MORNING HOURS. CHANCES INCREASE
FOR MODERATE TO HEAVY SNOW AT THESE SITES BETWEEN 15Z AND 21Z. AN
ADDITIONAL THREAT FOR A PERIOD OF HEAVY SNOW EXISTS FOR KEAU
SUNDAY EVENING ASSOCIATED WITH A MID LEVEL LOW MOVING THROUGH.
THERE COULD ALSO BE SOME THUNDER AS WELL. NORTHWEST WINDS WILL BE
ON THE INCREASE FOR KAXN AND KRWF IN THE EVENING WITH SUSTAINED
SPEEDS OF 15 TO 20 KNOTS LIKELY ALONG WITH GUSTS FROM 25 TO 30
KNOTS. HIGHER WINDS AFTER 11/06Z WITH 25G35KTS COMMON ALONG WITH
BLSN.
KMSP...SOME LIGHT PRECIPITATION WILL REACH THE AIRFIELD AFTER 09Z.
TRENDS CONTINUE TO POINT TO A MIX OF SNOW...SLEET AND FREEZING
RAIN IN THE 10Z-14Z TIME FRAME WITH MODERATE TO HEAVY SNOW LIKELY
FROM 15Z-19Z. SNOWFALL RATES DURING THE LATE MORNING AND EARLY
AFTERNOON HOURS COULD BE AROUND 2 INCHES AN HOUR. LIGHTER SNOW
EXPECTED DURING THE LATE AFTERNOON AND EVENING HOURS ALONG WITH
THE WIND BACKING TO THE NORTHWEST LATE IN THE EVENING WITH SPEEDS
OF 15 TO 20 KNOTS LIKELY ALONG WITH GUSTS OVERNIGHT FROM 25 TO 30
KNOTS.
/OUTLOOK FOR KMSP/
MON...IFR EARLY WITH -SN/BLSN...THEN MVFR WITH -SN. NW WINDS
18G30KTS.
TUE...VFR. W WINDS 5-10 KTS.
WED...VFR. W WINDS 5 TO 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST MONDAY FOR BLUE EARTH-
FARIBAULT-FREEBORN-LE SUEUR-MARTIN-RICE-SCOTT-STEELE-WASECA-
WATONWAN.
WINTER STORM WARNING UNTIL 9 PM CST THIS EVENING FOR BROWN-
CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-NICOLLET-POPE-
REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-YELLOW MEDICINE.
BLIZZARD WARNING FROM 9 PM THIS EVENING TO 6 PM CST MONDAY FOR
BROWN-CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-NICOLLET-
POPE-REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-YELLOW MEDICINE.
WINTER STORM WARNING UNTIL 6 PM CST MONDAY FOR CARVER-MCLEOD-
MEEKER-STEARNS-TODD-WRIGHT.
WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR ANOKA-BENTON-
CHISAGO-HENNEPIN-ISANTI-KANABEC-MILLE LACS-MORRISON-RAMSEY-
SHERBURNE-WASHINGTON.
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR DAKOTA-GOODHUE.
WI...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR CHIPPEWA-DUNN-
EAU CLAIRE-PEPIN-PIERCE.
WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR BARRON-POLK-RUSK-
ST. CROIX.
&&
$$
JRB/BORGHOFF
AREA FORECAST DISCUSSION
NWS BILLINGS MT
402 AM MST SUN FEB 10 2013
.SHORT TERM...VALID FOR TDY AND MON...
WITH THIS FORECAST PACKAGE...HAVE UPGRADED THE RED LODGE AND
BEARTOOTH FOOTHILLS TO A WINTER STORM WARNING AND CONTINUED THE
WINTER WEATHER ADVISORY FOR THE BIG HORN MOUNTAINS...SOUTHERN BIG
HORN COUNTY AND SHERIDAN COUNTY WYOMING.
VAD WINDS CONTINUE TO SHOW DEEP NORTHERLY FLOW UP ABOUT TO 10K
FEET AGL WITH MODELS SHOWING PLENTY OF MOISTURE AVAILABLE AND
UNSTABLE LAPSE RATES. THUS THE RED LODGE AND BEARTOOTH FOOTHILLS
ZONES CONTINUE TO SEE EXCELLENT UPSLOPE SNOW THIS MORNING.
REPORTS FROM AROUND MIDNIGHT SHOWED UP TO 5 INCHES OF SNOW HAD
ALREADY FALLEN. HOWEVER..SINCE MIDNIGHT...RADAR AND WEBCAMS
CONTINUE TO SHOW MODERATE TO HEAVY SNOW FALLING. BOTH THE RAP AND
NAM ARE LOCKED IN ON SETTLING A BAND OF UPSLOPE SNOW AGAINST THE
FOOTHILLS THROUGH THE MORNING. THIS AFTERNOON...THE UPSLOPE FLOW
WILL DIMINISH ALONG WITH SHALLOWING MOISTURE...CAUSING THE SNOW TO
TAPER OFF GOING INTO THIS EVENING. EXPECT TO SEE REPORTS OF 6 TO
10 INCHES OF SNOW WITH LOCALLY HIGHER AMOUNTS IN THIS AREA.
RADAR ALSO CONTINUES TO SHOW ENHANCED SNOWFALL ALONG THE BIG HORN
AND PRYOR MOUNTAIN FOOTHILLS AS WELL AS OVER THE BIG HORN
MOUNTAINS. SHERIDAN HAS LARGELY BEEN SHADOWED BY THE DOWNSLOPE
NORTHWEST WINDS OVERNIGHT...HOWEVER...ANTICIPATE SNOW TO INCREASE
THIS MORNING AS THE FRONTAL BOUNDARY SETTLES IN AGAINST THE
MOUNTAINS.
AREAS FROM BILLINGS TO HARLOWTON TO ROUNDUP WILL CONTINUE TO SEE
SOME SCATTERED SNOW SHOWERS THIS MORNING IN CONVECTIVE SNOW BANDS.
HOWEVER...WITH THE STIFF NORTHERLY WINDS...THESE AREAS WILL
LARGELY NOT SEE MUCH MORE SNOW ACCUMULATION AS RADAR CLEARLY
SHOWS THE DOWNSLOPING IS IN IN FULL EFFECT.
ALL OF THIS SNOWFALL HAS BEEN THE RESULT OF THE SHORTWAVE TROUGH
APPROACHING FROM THE NORTH. THE SHORTWAVE IS CURRENTLY SEEN ON WV
IMAGERY ENTERING NORTHERN MONTANA. THIS WAVE WILL SLOWLY TRACK
SOUTH ACROSS THE FORECAST AREA THROUGH THIS AFTERNOON. THE WAVE
WILL BE OVER THE FORECAST AREA BY THIS AFTERNOON...WHICH WILL
RESULT IN THE BEST FORCING SHIFTING SOUTH OF THE FORECAST
AREA...ALONG WITH THE NORTHERLY WINDS WEAKENING AND STARTING TO
TURN TO THE WEST. GIVEN THE INSTABILITY UNDER THE WAVE
AXIS...EXPECT SOME SCATTERED SNOW SHOWERS TO CONTINUE ACROSS
EASTERN MONTANA...ALTHOUGH ACCUMULATIONS WILL LIKELY BE VERY
LIGHT.
ALL PRECIPITATION WILL END ACROSS THE FORECAST AREA SUNDAY NIGHT
INTO MONDAY MORNING AS SHORTWAVE RIDGING BUILDS IN BEHIND THE
WAVE. SKIES WILL CLEAR OUT DURING THE DAY MONDAY...WITH WINDS
SWITCHING AROUND TO THE WEST AS PREVIOUSLY MENTIONED. THIS WILL
RESULT IN THE RETURN TO DOWNSLOPE FLOW ACROSS THE WESTERN AND
CENTRAL ZONES...ALLOWING US TO START THE START THE WARMING TREND.
THE PRESSURE GRADIENT LOOKS FAVORABLE FOR A CLARKS FOR DRAINAGE
FLOW FOR BILLINGS...RESULTING IN TEMPERATURES RUNNING IN THE LOW
30S AS COMPARED TO UPPER 30S IN SURROUNDING AREAS. THE PRESSURE
GRADIENT WILL CONTINUE TO TIGHTEN ACROSS WESTERN ZONES GOING INTO
MONDAY NIGHT...WHICH WILL RESULT IN A WINDY PERIOD FOR THE
FOOTHILLS FROM LIVINGSTON TO NYE. CHURCH
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
MEDIUM AND LONG RANGE MODELS IN GOOD AGREEMENT AND ONLY MINOR
ADJUSTMENTS MADE TO THE EXTENDED FORECAST.
FAST NORTHWESTER FLOW OF AIR ALOFT WILL BE OVER THE REGION
TUESDAY AND WEDNESDAY. SEVERAL SHORT WAVES MOVING THROUGH THIS
FLOW WILL ALLOW A LEE SIDE SURFACE TROUGH TO DEVELOP AND BRING GAP
FLOW WINDS TO THE SOUTHWEST VALLEYS. FLOW BECOMING NORTHERLY LATE
ON WEDNESDAY AS A STRONG JET AND SHORT WAVE ENERGY CARVE OUT A
TROUGH OF LOW PRESSURE OVER THE REGION. THIS WILL DRIVE A COLD
FRONT INTO OUR AREA WEDNESDAY AFTERNOON WITH STRONG COLD AIR
ADVECTION TO TAKE PLACE. SHOULD SEE A MIXTURE OF RAIN AND SNOW
DURING THE AFTERNOON...CHANGING TO ALL SNOW OVERNIGHT. STEEP LAPSE
RATES WILL BE OVER THE AREA FOR CONVECTIVE SNOW SHOWERS BUT
PRECIPITATION WILL BE HAMPERED BY NORTHWEST DOWN SLOPE WINDS OVER
THE PLAINS. THIS WILL LIMIT PRECIPITATION AMOUNTS FOR MOST AREAS.
NORTHWEST WINDS WILL UPSLOPE INTO SOUTHERN BIG HORN AND NORTHERN
WYOMING AND THESE AREAS COULD SEE ACCUMULATING SNOW BY THURSDAY
MORNING. BELOW SEASONAL TEMPERATURES ARE EXPECTED THURSDAY AND
FRIDAY BUT WILL WARM TO SEASONAL VALUES OVER THE WEEKEND AS A
RIDGE OF HIGH PRESSURE BUILDS IN OVER THE FORECAST AREA. RICHMOND
&&
.AVIATION...
AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE FORECAST AREA
TODAY. PERIODS OF SNOW WILL MOVE FROM NORTHWEST TO SOUTHEAST AND
WILL AFFECT ALL FLIGHT TERMINALS. MVFR TO LIFR CONDITIONS WILL BE
LIKELY DUE TO LOW CEILINGS AND POOR VISIBILITY. NORTHWEST WINDS
WILL BE INCREASING EAST OF A LINE FROM KSHR TO KMLS TODAY AND WILL
CREATE AREAS OF BLOWING SNOW. THE SNOW WILL BRING MOUNTAIN
OBSCURATIONS. SNOW WILL BE DECREASING FROM WEST TO EAST THIS
AFTERNOON. RICHMOND
&&
.PRELIMINARY POINT TEMP/POPS...
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 030 013/033 022/040 028/045 025/034 018/037 021/045
3/S 20/U 01/B 14/R 22/S 22/S 10/B
LVM 028 010/034 026/036 029/042 023/032 016/034 018/040
5/S 30/N 01/N 14/O 32/S 21/B 11/B
HDN 030 009/033 018/039 024/044 021/033 014/035 018/043
7/S 30/U 01/B 14/O 33/S 21/B 10/B
MLS 029 012/032 023/039 026/042 024/031 014/032 016/041
6/S 31/B 01/B 14/O 32/S 21/B 10/B
4BQ 029 011/030 017/037 025/042 022/031 011/031 016/040
7/S 51/B 01/B 13/O 33/S 22/S 10/B
BHK 027 010/026 019/035 023/038 020/027 009/027 013/037
7/S 51/B 01/B 03/S 33/S 22/S 10/B
SHR 027 006/028 012/037 020/041 017/029 012/031 016/041
9/S 40/U 01/B 14/O 33/S 32/S 10/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 8 PM MST THIS EVENING
FOR ZONE 38.
WINTER STORM WARNING IN EFFECT UNTIL 8 PM MST THIS EVENING
FOR ZONES 56-66.
WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL 8 PM MST THIS EVENING
FOR ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
925 AM EST SUN FEB 10 2013
.SYNOPSIS...
A FRONT WILL BRING A LIGHT WINTRY MIX, INCLUDING FREEZING RAIN
LATE TONIGHT INTO MONDAY MORNING, WITH A TRANSITION TO PLAIN
RAIN MONDAY. MONDAY NIGHT, A COLD FRONT WILL BRING COLDER
TEMPERATURES AND SNOW SHOWERS. THE SNOW SHOWERS AND FLURRIES WILL
BE DOWNWIND OF LAKE ONTARIO AND LAKE ERIE, AND LAST UNTIL
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
9 AM UPDATE...
EXTENDED THE CLOUDS AND FLURRIES FOR A FEW MORE HOURS. SATELLITE
SHOWING A SHRINKAGE IN COVERAGE. BY NOON THESE LOW CLOUDS WILL BE
GONE BUT HIGH CLOUDS ALREADY SPREADING IN FROM THE SW AHEAD OF THE
NEXT SYSTEM. ADJUSTED HOURLY TEMPERATURES. UNTIL SOME MIXING
HAPPENS THE CLOUDS WILL REMAIN HOLDING TEMPERATURES STEADY THERE.
OUTSIDE THE CLOUD AREAS TEMPERATURES RISING SLOWLY BUT HAVE A LONG
WAY TO GO STARTING BELOW ZERO.
400 AM UPDATE...MADE MINOR TWEAKS MAINLY TO CLD COVER AND TEMPS
ERLY THIS MORNING AS LOW CLDS STUBBORNLY HANG ON DOWNWIND OF LAKE
ONTARIO. I SUSPECT THESE CLDS WILL DISSIPATE AFTER SUNRISE. ALSO
HAVE A FEW FLURRIES FROM THESE CLOUDS AS SURFACE TEMPS ARE CLOSE
TO THE MAX ICE CRYSTAL GROWTH RATE...SUGGESTING ANY OROGRAPHIC
LIFTING CAN EASILY SQUEEZE OUT A FLURRY OR TWO.
PREVIOUS DISCUSSION BELOW FROM 1 AM UPDATE...
IR IMAGERY AND GOES 11-3.9 MICRON IMAGERY SHOWS PESKY LOW LAKE
EFFECT CLOUDS HANGING ON UNDER A SHARP VERY LOW-LEVEL INVERSION
WITHIN A SHALLOW NORTHWEST FLOW IN EC NY. KBGM 88D VWP SHOWS A
340-350 DEGREE WIND AT 10 KTS ABT 500 FEET AGL AND ALMOST LIGHT
AND VARIABLE ABOVE THIS. THIS LOW CLOUD LAYER THAT WAS MAINLY
DOWNWIND OF THE FINGER LAKES AND LAKE ONTARIO WAS SHRINKING AND
WILL CONTINUE TO DO SO AS THE LATEST RAP 925 MB LAYER WINDS
BETWEEEN 6 AND 9Z TURN MORE NORTH TO NORTHEAST AND WEAKEN...LOSING
THE OVERLAKE TRAJECTORIES. IN ADDITION OUR LOCAL WRF MODEL WITH
ITS HOURLY OUTPUT ALSO IS VERY SIMILAR AND DIMINISHES THE LOW CLD
COVER IN A SIMILAR FASHION AS PER THE DRYING OF THE 925 MB LAYER
AS THE 925 MB WINDS SHIFT MORE NRLY AND LOSE LAKE TRAJECTORIES.
HENCE HAVE CLOUDS DIMINISHING FOR THE REMAINDER OF THE EARLY
MORNING HOURS. MINS WILL BE TRICKY GIVING THE WIDE RANGE OF
TEMPERATURES OBSERVED AT PRESENT DUE TO CLD CVR. IN CLD CVR AREAS
TEMPS ARE IN THE TEENS WITH TEMPERATURES RAPIDLY DROPPING TO NEAR
ZERO IN CLR SKY AREAS. I HAVE MINS RANGING FROM SUB ZERO SINGLE
DIGITS MAINLY TO SINGLE DIGITS WHERE CLD CLEAR LATEST IN EC NY.
FOR SUNDAY...SFC HIGH PRESSURE RDG AXIS IS OVHD AT 12Z AND RAPIDLY
SHIFTS EAST DURING THE DAY...REACHING OFFSHORE BY EVENING.
MEANWHILE NEXT STORM WAS BEGINNING TO WORK EASTWARD. THE 850 AND
925 MB WAA BEGINS DURING THE DAY AS SOUTHERLY WINDS
INCREASE...THIS WILL ALSO POP UP AN UPPER LEVEL RDG OVHD DURING
THE DAY SUNDAY. SOME HIGHER CLDS WILL ADVECT IN OVER THE UPR RDG...
BUT THE DEEPER MID LAYER CLDS HOLD OFF MOST OF THE DAY REACHING
WRN NY LATE. I SEE MAINLY CIRRUS OVERSPREADING C NY AND NE PA DURING
AFTERNOON WITH A MILDER DAY IN STORE DUE TO LL WARM ADVECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
ALL 00Z MODELS...INCLUDING THE NAM12...GFS40...CMC AND EURO ALL
TRACK THE NEXT SIGNIFICANT CYCLONE TRACKING INTO WI BY 6Z MONDAY.
AT UPPER LEVELS THERE WAS A LOW OVER THE WESTERN LAKES REGION
WITH A PERSISTENT UPPER LVL RDG OFF THE SE COAST TO THE WRN GULF
COAST. AS A RESULT OF THIS UPPER LEVEL GEOPOTENTIAL FIELD...THERE
WAS A STRONG UPPER LEVEL JET STREAK THAT WILL PUNCH INTO THE OHIO
VALLEY BETWEEN 6Z AND 18Z MONDAY. THIS WILL INDUCED A STRONG
SOUTHERLY LOW-LEVEL JET ARND 850 MB UP INTO NY AND PA TONIGHT/ERLY MON.
THIS LLJ WILL FEATURE STRONG MOISTURE ADVECTION AND RISE
ISENTROPICALLY. ALL MODELS AGREE THAT PRECIP SPREADS FROM WEST TO
EAST ACROSS CENTRAL NY AND NE PA BTWN 6Z AND 12Z MONDAY. WILL RAMP
POPS UP TO CATEGORICAL BY 12Z ALL FORECAST AREA.
NOW TO P-TYPE. INITIALLY TEMPERATURES AND DEWPOINTS MOST OF CWA
WILL BE BELOW FREEZING WITH SUB FREEZING DWPTS AS WELL LATE TONIGHT.
MODEL GUIDC SUGGESTS OUR DOWNSLOPE REGIONS IN THE NRN FINGER LAKES
ACTUALLY REMAIN ABV FREEZING WHICH IS NOT UNUSUAL TONIGHT. SO I WUD
EXPECT STEADY AND SLOWING RISING TEMPERATURES SUNDAY NIGHT REST OF
ZFORECAST AREA. WHEN PRECIP ARRIVES IT WILL BE MAINLY ZR INITIALLY
WITH POSSIBLY SOME IP...BUT WITH 850 MB TEMPS ABV FREEZING DON/T
SEE SNOW. PRECIPITATION WILL RAPIDLY TURN OVER TO PLAIN RAIN
MONDAY DURING THE MORNING MOST OF CWA AS TEMPS WARM ABV FREEZING.
THE LAST HOLD OUTS WILL BE IN THE FAR EASTERN PART OF THE CWA FROM
SULLIVAN CO TO THE UPPER MOHAWK VALLEY WHERE ZR WILL LAST UNTIL
AFTERNOON. ICE AMNTS WILL BE LIGHT...GENERALLY UNDER
.1 INCHES...HOWEVER I SEE SOME AREAS IN THE CATSKILLS TO MOHAWK
VALLEY SEEING MAYBE UP TO .15 INCH. MAIN IMPACT WILL BE TO TRAVEL.
FOR NOW HELD OFF ON ISSUING ANY FLAGS FOR FREEZING RAIN AS NOT SURE
AS TO THE EXTENT OR AREAL COVERAGE OF THE ICING. THERE IS PLENTY
OF TIME AT THIS POINT IN OUR FORECAST AREA SO WILL LET DAY SHIFT
HANDLE. I SUSPECT AN ADVY WILL BE ISSUED FOR A LARGE PART OF THE
FORECAST AREA THIS AFTERNOON FOR LATE TONIGHT/MONDAY MORNING.
THEN BY AFTERNOON MONDAY...RAIN SHEILD ASSOCIATED WITH WARM/MOIST
CONVEYOR BELT IS EAST OF REGION AND THE COLD FRONT WILL SWING THRU
BETWEEN 21Z MON AND 02Z TUE. THIS FEATURE WILL BE ACCOMPANIED BY
CAA AND MAINLY SNOW SHOWERS WHICH WILL MIX WITH RAIN SHOWERS
INITIALLY.
FOR MONDAY NIGHT INTO EARLY TUESDAY...THE LL FLOW IS MORE W-SW
WHICH SHUD DIRECTLY ANY LAKE MOISTURE AND DEVELOPING LES MAINLY N
OF THE BGM FORECAST AREA. H85 TEMPS AT THIS POINT WILL BE MARGINAL
AT BEST SO DOESN/T LOOK LIKE MUCH BEFORE TUE AM IN C NY OR NE PA
OTHER THAN A FEW SNOW SHOWERS OR FLURRIES.
THEN TUE INTO TUE NGT...ANOTHER WAVE AND ASSOCIATED COLD FRONT AND
SURGE OF COLDER AIR PRESSES SOUTH TWD NY AND TURNS THE LL FLOW
MORE W-NW WHICH COMBINED WITH H85 TEMPS DROPPING TO -12C SHUD TRIGGER
SOME LAKE RESPONSE. FOR NOW HAVE POPS IN FOR LES NC NY LATER TUE
INTO TUE NGT. THE NAM HOLDS ONTO THE LES LONGER THRU TUE NGT...GFS
BACKS FLOW QUICKER TUE NGT. NOT SURE EXACTLY ON TIMING THIS FAR
OUT SO PRETTY MUCH WENT WITH SCENARIO THAT KEEPS THE LES IN
LONGER NC NY. NOT LOOKING FOR A MAJOR EVENT. GFS AND NAM SOUNDINGS
FOR SYR SHOW INVERSION BARELY AT 850 MB AND MAX LIFT BELOW THE MAX
GROWTH RATE FOR ICE CRYSTALS. I CUD SEE A FEW INCHES BUT NO
WARNING AMNTS FOR LAKE SNOW BELTS IN NC NY...SO NO LES WATCH. REST OF
FORECAST AREA WILL SEE TYPICAL BKN SC LAYER WITH SCATTERED
FLURRIES OR EVEN SNOW SHOWERS WITH THE DAY/S HEATING. NO ACCUMS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
NOT A DEAD QUIET PATTERN...BUT NOTHING BIG GOING ON EITHER...AT
LEAST NOT YET. THIS PERIOD WILL FEATURE A SPLIT FLOW PATTERN WITH
ALTERNATING WEAK NORTHERN STREAM AND SOUTHERN STREAM WAVES JUST
BARELY SKIMMING BY THE AREA. TEMPERATURES WILL BE NEAR OR JUST A
TOUCH ABOVE CLIMATOLOGY. I WAS COMFORTABLE FOLLOWING HPC GUIDANCE
INCLUDING JUST SLIGHT TO LOW CHANCE POPS...AND MAINLY SNOW SHOWERS
AS PRECIP TYPE...THOUGH PERHAPS MIXED WITH RAIN BY FRIDAY AS FLOW
BECOMES MORE SOUTHWESTERLY. MORE AMPLIFICATION TO THE FLOW OCCURS
HEADING INTO THE WEEKEND...SO WE WILL HAVE TO SEE IF MORE
SIGNIFICANT WAVES WILL BE ABLE TO IMPACT OUR WEATHER BY THEN.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
PERSISTENT LOW CLDS CONTS TO DRIFT OFF LAKE ONTARIO THIS MRNG
BRING MVFR AND IFR CIGS TO SOME OF THE TAF SITES. XPCT HTG AND
HIPRES TO FNLY LIFT THESE CLDS AWAY FROM THE AREA LEAVING VFR
CONDS LTR THIS MRNG. VFR CONDS WILL REMAIN THRU MUCH OF THE PD UNTIL
A WRM FNT APRCHS FROM THE WEST. THIS WILL BRING CLDS AND
OVERRIDING WRM AIR. THE RESULT WILL BE CIGS LWRD TO MVFR LVLS AND
MVFR VSBYS IN MIXED PCPN.
.OUTLOOK...
MON...MVFR/IFR IN LIGHT WINTRY MIX LATE SUN NIGHT INTO MON
MORNING /INCLUDING FREEZING RAIN/...CHANGING TO ALL RAIN MON.
MON NGT/TUE/TUE NGT...SCT MVFR CNTRL NY IN -SHSN...VFR ELSEWHERE.
WED/THU...VFR MUCH OF THE TIME...BUT MVFR -SN POSSIBLE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/TAC
NEAR TERM...DJN/TAC
SHORT TERM...DJN
LONG TERM...MDP
AVIATION...DGM/DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
648 AM EST SUN FEB 10 2013
.SYNOPSIS...
SUNNY AND MILDER WEATHER IS EXPECTED TODAY AS HIGH PRESSURE MOVES
OFF THE EAST COAST AND A SOUTHERLY FLOW OF AIR DEVELOPS. A LOW
PRESSURE SYSTEM WILL BRING A LIGHT WINTRY MIX INCLUDING FREEZING
RAIN LATE TONIGHT INTO MONDAY MORNING...WITH A TRANSITION TO PLAIN
RAIN MONDAY. AFTER THIS LOW PRESSURE SYSTEM PASSES BY TO THE
NORTHEAST MONDAY NIGHT, IT WILL SWING A COLD FRONT THROUGH THE
AREA WITH A RETURN TO COLDER TEMPERATURES. THIS WILL LEAD TO SNOW
SHOWERS AND FLURRIES DOWNWIND OF LAKE ONTARIO AND LAKE ERIE UNTIL
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
400 AM UPDATE...MADE MINOR TWEEKS MAINLY TO CLD COVER AND TEMPS
ERLY THIS MORNING AS LOW CLDS STUBBORNLY HANG ON DOWNWIND OF LAKE
ONTARIO. I SUSPECT THESE CLDS WILL DISSIPATE AFTER SUNRISE. ALSO
HAVE A FEW FLURRIES FROM THESE CLOUDS AS SURFACE TEMPS ARE CLOSE
TO THE MAX ICE CRYSTAL GROWTH RATE...SUGGESTING ANY OROGRAPHIC
LIFTING CAN EASILY SQUEEZE OUT A FLURRY OR TWO.
PREVIOUS DISCUSSION BELOW FROM 1 AM UPDATE...
IR IMAGERY AND GOES 11-3.9 MIRCON IMAGERY SHOWS PESKY LOW LAKE
EFFECT CLOUDS HANGING ON UNDER A SHARP VERY LOW-LEVEL INVERSION
WITHIN A SHALLOW NORTHWEST FLOW IN EC NY. KBGM 88D VWP SHOWS A
340-350 DEGREE WIND AT 10 KTS ABT 500 FEET AGL AND ALMOST LIGHT
AND VARIABLE ABOVE THIS. THIS LOW CLOUD LAYER THAT WAS MAINLY
DOWNWIND OF THE FINGER LAKES AND LAKE ONTARIO WAS SHRINKING AND
WILL CONTINUE TO DO SO AS THE LATEST RAP 925 MB LAYER WINDS
BETWEEEN 6 AND 9Z TURN MORE NORTH TO NORTHEAST AND WEAKEN...LOSING
THE OVERLAKE TRAJECTORIES. IN ADDITION OUR LOCAL WRF MODEL WITH
ITS HOURLY OUTPUT ALSO IS VERY SIMILAR AND DIMINISHES THE LOW CLD
COVER IN A SIMILAR FASHION AS PER THE DRYING OF THE 925 MB LAYER
AS THE 925 MB WINDS SHIFT MORE NRLY AND LOSE LAKE TRAJECTORIES.
HENCE HAVE CLOUDS DIMINISHING FOR THE REMAINDER OF THE EARLY
MORNING HOURS. MINS WILL BE TRICKY GIVING THE WIDE RANGE OF
TEMPERATURES OBSERVED AT PRESENT DUE TO CLD CVR. IN CLD CVR AREAS
TEMPS ARE IN THE TEENS WITH TEMPERATURES RAPIDLY DROPPING TO NEAR
ZERO IN CLR SKY AREAS. I HAVE MINS RANGING FROM SUB ZERO SINGLE
DIGITS MAINLY TO SINGLE DIGITS WHERE CLD CLEAR LATEST IN EC NY.
FOR SUNDAY...SFC HIGH PRESSURE RDG AXIS IS OVHD AT 12Z AND RAPIDLY
SHIFTS EAST DURING THE DAY...REACHING OFFSHORE BY EVENING.
MEANWHILE NEXT STORM WAS BEGINNING TO WORK EASTWARD. THE 850 AND
925 MB WAA BEGINS DURING THE DAY AS SOUTHERLY WINDS
INCREASE...THIS WILL ALSO POP UP AN UPPER LEVEL RDG OVHD DURING
THE DAY SUNDAY. SOME HIGHER CLDS WILL ADVECT IN OVER THE UPR RDG...
BUT THE DEEPER MID LAYER CLDS HOLD OFF MOST OF THE DAY REACHING
WRN NY LATE. I SEE MAINLY CIRRUS OVERSPREADING C NY AND NE PA DURING
AFTERNOON WITH A MILDER DAY IN STORE DUE TO LL WARM ADVECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
ALL 00Z MODELS...INCLUDING THE NAM12...GFS40...CMC AND EURO ALL
TRACK THE NEXT SIGNIFICANT CYCLONE TRACKING INTO WI BY 6Z MONDAY.
AT UPPER LEVELS THERE WAS A LOW OVER THE WESTERN LAKES REGION
WITH A PERSISTENT UPPER LVL RDG OFF THE SE COAST TO THE WRN GULF
COAST. AS A RESULT OF THIS UPPER LEVEL GEOPOTENTIAL FIELD...THERE
WAS A STRONG UPPER LEVEL JET STREAK THAT WILL PUNCH INTO THE OHIO
VALLEY BETWEEN 6Z AND 18Z MONDAY. THIS WILL INDUCED A STRONG
SOUTHERLY LOW-LEVEL JET ARND 850 MB UP INTO NY AND PA TONIGHT/ERLY MON.
THIS LLJ WILL FEATURE STRONG MOISTURE ADVECTION AND RISE
ISENTROPICALLY. ALL MODELS AGREE THAT PRECIP SPREADS FROM WEST TO
EAST ACROSS CENTRAL NY AND NE PA BTWN 6Z AND 12Z MONDAY. WILL RAMP
POPS UP TO CATEGORICAL BY 12Z ALL FORECAST AREA.
NOW TO P-TYPE. INITIALLY TEMPERATURES AND DEWPOINTS MOST OF CWA
WILL BE BELOW FREEZING WITH SUB FREEZING DWPTS AS WELL LATE TONIGHT.
MODEL GUIDC SUGGESTS OUR DOWNSLOPE REGIONS IN THE NRN FINGER LAKES
ACTUALLY REMAIN ABV FREEZING WHICH IS NOT UNUSUAL TONIGHT. SO I WUD
EXPECT STEADY AND SLOWING RISING TEMPERATURES SUNDAY NIGHT REST OF
ZFORECAST AREA. WHEN PRECIP ARRIVES IT WILL BE MAINLY ZR INITIALLY
WITH POSSIBLY SOME IP...BUT WITH 850 MB TEMPS ABV FREEZING DON/T
SEE SNOW. PRECIPITATION WILL RAPIDLY TURN OVER TO PLAIN RAIN
MONDAY DURING THE MORNING MOST OF CWA AS TEMPS WARM ABV FREEZING.
THE LAST HOLD OUTS WILL BE IN THE FAR EASTERN PART OF THE CWA FROM
SULLIVAN CO TO THE UPPER MOHAWK VALLEY WHERE ZR WILL LAST UNTIL
AFTERNOON. ICE AMNTS WILL BE LIGHT...GENERALLY UNDER
.1 INCHES...HOWEVER I SEE SOME AREAS IN THE CATSKILLS TO MOHAWK
VALLEY SEEING MAYBE UP TO .15 INCH. MAIN IMPACT WILL BE TO TRAVEL.
FOR NOW HELD OFF ON ISSUING ANY FLAGS FOR FREEZING RAIN AS NOT SURE
AS TO THE EXTENT OR AREAL COVERAGE OF THE ICING. THERE IS PLENTY
OF TIME AT THIS POINT IN OUR FORECAST AREA SO WILL LET DAY SHIFT
HANDLE. I SUSPECT AN ADVY WILL BE ISSUED FOR A LARGE PART OF THE
FORECAST AREA THIS AFTERNOON FOR LATE TONIGHT/MONDAY MORNING.
THEN BY AFTERNOON MONDAY...RAIN SHEILD ASSOCIATED WITH WARM/MOIST
CONVEYOR BELT IS EAST OF REGION AND THE COLD FRONT WILL SWING THRU
BETWEEN 21Z MON AND 02Z TUE. THIS FEATURE WILL BE ACCOMPANIED BY
CAA AND MAINLY SNOW SHOWERS WHICH WILL MIX WITH RAIN SHOWERS
INITIALLY.
FOR MONDAY NIGHT INTO EARLY TUESDAY...THE LL FLOW IS MORE W-SW
WHICH SHUD DIRECTLY ANY LAKE MOISTURE AND DEVELOPING LES MAINLY N
OF THE BGM FORECAST AREA. H85 TEMPS AT THIS POINT WILL BE MARGINAL
AT BEST SO DOESN/T LOOK LIKE MUCH BEFORE TUE AM IN C NY OR NE PA
OTHER THAN A FEW SNOW SHOWERS OR FLURRIES.
THEN TUE INTO TUE NGT...ANOTHER WAVE AND ASSOCIATED COLD FRONT AND
SURGE OF COLDER AIR PRESSES SOUTH TWD NY AND TURNS THE LL FLOW
MORE W-NW WHICH COMBINED WITH H85 TEMPS DROPPING TO -12C SHUD TRIGGER
SOME LAKE RESPONSE. FOR NOW HAVE POPS IN FOR LES NC NY LATER TUE
INTO TUE NGT. THE NAM HOLDS ONTO THE LES LONGER THRU TUE NGT...GFS
BACKS FLOW QUICKER TUE NGT. NOT SURE EXACTLY ON TIMING THIS FAR
OUT SO PRETTY MUCH WENT WITH SCENARIO THAT KEEPS THE LES IN
LONGER NC NY. NOT LOOKING FOR A MAJOR EVENT. GFS AND NAM SOUNDINGS
FOR SYR SHOW INVERSION BARELY AT 850 MB AND MAX LIFT BELOW THE MAX
GROWTH RATE FOR ICE CRYSTALS. I CUD SEE A FEW INCHES BUT NO
WARNING AMNTS FOR LAKE SNOW BELTS IN NC NY...SO NO LES WATCH. REST OF
FORECAST AREA WILL SEE TYPICAL BKN SC LAYER WITH SCATTERED
FLURRIES OR EVEN SNOW SHOWERS WITH THE DAY/S HEATING. NO ACCUMS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
NOT A DEAD QUIET PATTERN...BUT NOTHING BIG GOING ON EITHER...AT
LEAST NOT YET. THIS PERIOD WILL FEATURE A SPLIT FLOW PATTERN WITH
ALTERNATING WEAK NORTHERN STREAM AND SOUTHERN STREAM WAVES JUST
BARELY SKIMMING BY THE AREA. TEMPERATURES WILL BE NEAR OR JUST A
TOUCH ABOVE CLIMATOLOGY. I WAS COMFORTABLE FOLLOWING HPC GUIDANCE
INCLUDING JUST SLIGHT TO LOW CHANCE POPS...AND MAINLY SNOW SHOWERS
AS PRECIP TYPE...THOUGH PERHAPS MIXED WITH RAIN BY FRIDAY AS FLOW
BECOMES MORE SOUTHWESTERLY. MORE AMPLIFICATION TO THE FLOW OCCURS
HEADING INTO THE WEEKEND...SO WE WILL HAVE TO SEE IF MORE
SIGNIFICANT WAVES WILL BE ABLE TO IMPACT OUR WEATHER BY THEN.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
PERSISTENT LOW CLDS CONTS TO DRIFT OFF LAKE ONTARIO THIS MRNG
BRING MVFR AND IFR CIGS TO SOME OF THE TAF SITES. XPCT HTG AND
HIPRES TO FNLY LIFT THESE CLDS AWAY FROM THE AREA LEAVING VFR
CONDS LTR THIS MRNG. VFR CONDS WILL REMAIN THRU MUCH OF THE PD UNTIL
A WRM FNT APRCHS FROM THE WEST. THIS WILL BRING CLDS AND
OVERRIDING WRM AIR. THE RESULT WILL BE CIGS LWRD TO MVFR LVLS AND
MVFR VSBYS IN MIXED PCPN.
.OUTLOOK...
MON...MVFR/IFR IN LIGHT WINTRY MIX LATE SUN NIGHT INTO MON
MORNING /INCLUDING FREEZING RAIN/...CHANGING TO ALL RAIN MON.
MON NGT/TUE/TUE NGT...SCT MVFR CNTRL NY IN -SHSN...VFR ELSEWHERE.
WED/THU...VFR MUCH OF THE TIME...BUT MVFR -SN POSSIBLE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...MDP
AVIATION...DGM/DJP
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
545 AM EST SUN FEB 10 2013
.SYNOPSIS...
SOUTHERLY FLOW INCREASES TODAY. PSEUDO WARM FRONT LIFTING NORTH INTO
KENTUCKY TODAY. COLD FRONT PASSES MONDAY. HIGH PRESSURE TUESDAY.
LOW PRESSURE PASSES TO THE SOUTH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
WIDE RANGE OF TEMPERATURES OVERNIGHT...FROM NEAR 10 DEGREES IN THE
COLDEST MOUNTAIN VALLEYS OF WEST VIRGINIA...TO NEAR 30 ALONG EXPOSED
MOUNTAIN RIDGES.
FIGURING ON HIGH AND MID CLOUDS THICKENING THIS MORNING...WITH SOME
RADAR RETURNS FROM IT...THEN THIN OUT A BIT FOR A PERIOD THIS
AFTERNOON....BEFORE THE DEEPER MOISTURE KNOCKS ON THE DOOR IN OUR
WESTERN COUNTIES BY DARK.
925 MB FLOW INCREASES AT 25 TO 30 KNOTS FROM THE SSE BY 21Z. WILL
INCREASE GUSTS OVER THE MOUNTAIN COUNTIES...INCLUDING SW VIRGINIA
THIS AFTERNOON.
WITH THE FLOW REMAINING MOSTLY SSE THIS EVENING...NOT SE...THINKING
TEMPERATURES IN OUR COLDEST SPOTS IN THE UPPER GREENBRIER VALLEY
WILL DROP TO AROUND 33 OR 34 DEGREES AFTER THE ONSET OF THE RAIN.
SO NOT THINKING READINGS WILL DROP BELOW FREEZING. WILL INSERT A
SLIGHT CHANCE OF SOME POCKETS OF FREEZING RAIN FOR ABOUT 4 HOURS
CENTERED ON MIDNIGHT FOR THOSE LOCATIONS...INCLUDING PORTIONS OF
POCAHONTAS AND EASTERN RANDOLPH COUNTIES. HAVE TEMPERATURES RISING
DURING THE PREDAWN AS WINDS VEER TO SW THERE.
NO BIG CHANGES ON POPS...WITH HOURLY POPS DECREASING QUICKLY BEFORE
12Z IN THE WESTERN LOWLANDS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AREA GETS INTO INCREASINGLY ALIGNED WSW FLOW AS UPPER LEVEL LOW
TRAVERSES GREAT LAKES MON. DEEP LAYER MOISTURE EXITS FIRST THING IN
THE MORNING...AS UPPER LEVEL JET MAX PASSES. THIS WILL LEAD TO
INCREASINGLY MIXED AIR MASS THAT MAY BECOME DRY ADIABATIC ALL THE
WAY TO H7. HAVE WINDS REACHING CRITERIA FOR ADV ONLY FOR HIGHEST
ELEVATIONS SO FAR VIA RUC MOMENTUM MIXING ALGORITHM.
HIGH PRESSURE SLOWLY BUILDS IN ON TUE...ONLY TO RETREAT TUE NT AS
NEXT S/W TROF APPROACHES FROM THE W. ASSOCIATED CONFLUENCE ZONE
SETS UP ACROSS NRN PA AS SFC LOW TRACKS TO THE S...THE GFS/ECMWF
SOLN FAVORED OVER THE NAM12...WHICH IS THE ODD MODEL N. CANADIAN IS
EVEN FURTHER S. HAVE LIMITED LIKELY POPS TO FAR S PORTION OF THE
AREA.
WHILE THIS IS A SYNOPTICALLY CORRECT TRACK FOR SNOW...BORING
PACIFIC AIR MASS IN PLACE AHEAD OF THE SYSTEM LEAVES TEMPERATURES
ONLY MARGINALLY LOW ENOUGH...ESPECIALLY AT THE SFC...GIVING RISE TO
MIXED PRECIPITATION AND EVEN JUST RAIN. HAVE MINIMAL SNOW AMOUNTS
OF JUST OVER AN INCH ON THE CENTRAL MOUNTAINS AS SYSTEM EXITS WED
AFTERNOON...AND VERY LITTLE ICE. TOGETHER WITH POPS MAINLY IN THE
CHANCE RANGE...HAVE NO HWO MENTION WARRANTED AT THIS POINT AS
CONFIDENCE IN CODABLE WINTER EVENT IS QUITE LOW.
BLENDED IN ADJMET FOR TEMPERATURES EARLY ON...THEN ADJMAV / ADJMEX
TOWARD THE END IN LIGHT OF GFS SOLN. THIS KEEPS FCST LARGELY IN
LINE WITH PREVIOUS PACKAGE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
MDL TRENDS CONT TO CLOSE IN ON OP GFS SOLUTIONS AT LEAST REGARDING
S/W TROF ON WED. 12Z ECWMF CONT THE TREND AS WELL. STILL SOME
UNCERTAINTIES WITH SFC LOW TRACK...BUT ALL AGREE AT LEAST SOME
INFLUENCE FROM INVERTED SFC TROUBLE. ELECTED TO RAISE POPS INTO LKLY
ACROSS SW VA AND IN THE WV MTNS...WITH HIGH CHC ACROSS THE LOWLANDS.
APPEARS LLVL TEMPS WILL BE WARM ENOUGH FOR PERHAPS MAINLY RA BLO
2KFT. SYS PULLS OUT QUICKLY WED EVE FOR A RETURN TO DRY WX THU AND
MOST OF FRI.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
ABUNDANT HIGH AND MID CLOUDS AOA 10 THSD FT THROUGH ABOUT 22Z BEFORE
THICKENING AND LOWERING. MAYBE SPRINKLES REACHING THE GROUND IN
SOUTHEAST OHIO THIS MORNING.
CEILINGS BECOMING 4 TO 8 THSD FT 23Z SUNDAY TO 03Z MONDAY WITH LIGHT
RAIN LIMITING VSBY 3 TO 5 MILES BY 03Z TO 06Z. CEILINGS BECOMING 2
TO 3 THSD FT BY 06Z MONDAY IN WIDESPREAD RAIN...BECOMING AOB 1 THSD
FT BKN OVER MOUNTAINS. A SLIGHT CHANCE OF A POCKET OF FREEZING RAIN
IN POCAHONTAS COUNTY AROUND 06Z.
MAIN RAIN SHIELD SHIFTING EAST..AWAY FROM THE LOWLAND COUNTIES
AFTER 08Z...WITH VSBY AOA 5 MILES BUT CEILINGS REMAINING MOSTLY 2 TO
3 THSD FT BKN/OVC.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING OF ARRIVAL OF THE RAIN MAY VARY
BY A COUPLE OF HOURS SUNDAY EVENING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z MONDAY...
IFR POSSIBLE AGAIN WEDNESDAY AND WEDNESDAY NIGHT IN LIGHT RAIN OR
SNOW...MAINLY MOUNTAIN COUNTIES.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/TRM
NEAR TERM...KTB
SHORT TERM...TRM
LONG TERM...30
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
601 AM CST SUN FEB 10 2013
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
230 AM CST SUN FEB 10 2013
FORECAST FOCUS IS ON THE STORM SYSTEM THAT SLIDES ACROSS THE REGION
TODAY...WITH CONTINUING PCPN INTO MONDAY.
LATEST WATER VAPOR SATELLITE IMAGERY PLACES THE SHORTWAVE OVER THE
SOUTHERN PLAINS...WITH THE 00Z MODEL RUNS ALL DRIVING IT NORTHEAST
ACROSS THE FORECAST AREA BY THIS EVENING. RELATIVELY WEAK
FRONTOGENETIC FORCING VIA NAM12/RAP LOOKS RESPONSIBLE FOR THE
CURRENT BAND OF LIGHT PCPN RUNNING NORTHWEST-SOUTHEAST FROM SOUTHERN
MN THROUGH IA. THIS WILL CONTINUE TO LIFT NORTHEAST THROUGH THE
MORNING. THE BULK OF THIS SYSTEM/S FORCING IS POST THIS BAND
HOWEVER...WITH THE STRONG LOW LEVEL THERMODYNAMIC LIFT VIA WARM
ADVECTION/ISENTROPIC UPGLIDE ON THE LEADING EDGE OF THE SHORTWAVE
LIFTING ACROSS THE REGION FROM THE LATE MORNING THROUGH THE
AFTERNOON. THE MODELS KEY ON THIS FORCING FOR THE SYSTEM/S MAIN PCPN
BAND. PLENTY OF MOISTURE TO WORK WITH FOR EARLY FEB...WITH A STRONG
PUSH OF 850 MB MOISTURE TRANSPORT ON THE NOSE OF 50 KT LOW LEVEL
JET. PWS ARE NEARLY 300 PERCENT ABOVE NORMAL WITH SREF ANOMALIES
AROUND +3. IN ADDITION...THE FRONTOGENETIC FORCING IS NEARLY UPRIGHT
AT TIMES...PER NORTHEAST-SOUTHWEST RUNNING X-SECTIONS...AND THIS
COUPLED WITH THE NOSE OF THE LOW LEVEL JET COULD RESULT IN SOME
CONVECTION. A CRACK OR TWO OF THUNDER CAN/T BE RULED OUT...MOSTLY TO
THE SOUTH.
THE PCPN BAND MOVES NORTH OF THE FORECAST AREA BY 00Z...WITH THE
STORM SYSTEM/S SFC LOW OVER NORTHERN IA BY THIS TIME. NAM/GFS
CONTINUE TO INDICATE THAT A SMALLER AREA OF PCPN WILL DEVELOP WITH
THE LOW...ASSOCIATED WITH UPPER LEVEL ENERGY BEING WRAPPED HARD
AROUND THE STORM...AND SOME SFC TROUGHINESS RESULTING IN
CONVERGENCE. THIS AREA OF ENHANCED QPF WOULD FALL ACROSS SOUTHEAST
MN THIS EVENING...SHUFFLING ACROSS NORTHERN WI OVERNIGHT.
ELSEWHERE...ENOUGH BROADSCALE LIFT WITH AMPLE SATURATION THAT AREAS
OF LIGHT PCPN ARE LIKELY. WITH THE COLD FRONTAL PASSAGE IN THE
EVENING...EXPECT A TRANSITION FROM RAIN TO SNOW.
THE SNOW WILL LINGER ON MONDAY...WITH AN INVERTED SFC TROUGH HANGING
WEST OF THE EASTWARD MOVING LOW...BITS OF UPPER LEVEL ENERGY...AND
FAVORABLE LOW LEVEL LAPSE RATES HELPING SPARK THE SNOW. THE BETTER
CHANCES WILL LIE MOSTLY ALONG AND NORTH OF I-90...WITH ADDITIONAL
ACCUMULATIONS ON MONDAY OF AN INCH OR LESS.
AS IT HAS APPEARED THE PAST FEW DAYS...THERE APPEARS TO BE 3
DIFFERENT PCPN PHASES WITH THIS STORM SYSTEM...OR PERHAPS 4 NOW.
SFC OBS WITH THE FRONTOGENETIC PCPN BAND MOVING NORTHEAST INDICATES
MOSTLY RAIN RIGHT NOW...ALTHOUGH THE CONVECTIVE NATURE WOULD SUGGEST
THAT ANY HIGH RETURNS COULD BE...OR PERHAPS ARE MORE LIKELY TO
BE...SLEET. RAP BUFKIT SOUNDINGS OVER NORTHEAST IA HAVE A 1-2 C WARM
LAYER...WHICH GRADUALLY DEEPENS. THE ATMOSPHERE CONTINUES TO
WARM...BUT AS IT DOES...THE CLOUDS LOSE THEIR ICE BEHIND THIS FIRST
PCPN BAND. CURRENT IR/SATELLITE CLOUD TEMPS INDICATE THIS AS WELL.
SO...COULD SEE A FREEZING RAIN/SLEET MIX CHANGE OVER TO FREEZING
DRIZZLE FOR EARLY THIS MORNING...ALL SFC TEMP DEPENDENT OF COURSE.
BUT REMEMBER - EVEN AS TEMPS WARM THROUGH THE DAY...ROAD TEMPS ARE
COLDER...MOSTLY IN THE UPPER 20S...AND ICY SPOTS WILL DEVELOP IF
THEY ARE UNTREATED.
THE MAIN BAND OF PCPN...THE BAND THAT WILL BRING MOST OF THE QPF TO
THE FORECAST AREA...IS EXPECTED TO DEVELOP JUST TO THE
SOUTHWEST...MOVING NORTHEAST ACROSS THE REGION LATE
MORNING/AFTERNOON. GOOD PUSH OF LOW LEVEL WARM AIR WITH THIS
PCPN...GENERALLY 1-3 C AT MAX. THIS IS SUGGESTIVE OF ONLY PARTIAL
MELTING...WHICH WOULD RESULT IN SLEET. HOWEVER...THE DEPTH OF THIS
WARM LAYER EXCEEDS 3 KFT IN SOME LOCATIONS - WHICH COULD RESULT IN
FULL MELTING. HOWEVER...THE TRACK OF THE SYSTEM KEEPS IT A BIT
COLDER WEST OF THE MISSISSIPPI RIVER...EVIDENCED IN A WEST-EAST
RUNNING X-SECTION AND BUFKIT SOUNDINGS. NAM12 BUFKIT SOUNDINGS AT
KRST WOULD FAVOR SNOW TO A SNOW/RAIN MIX...SFC TEMP DEPENDENT. NOT
MUCH OF A DENDRITIC SNOW REGION...BUT ITS ISOTHERMAL AROUND 0 C FOR
A FEW HOURS. WOULD EXPECT A WET SNOW WITH LOWER SNOW RATIOS. WILL
HAVE TO TREND FROM WEST TO EAST AND SOUTH TO NORTH WITH PCPN TYPES.
AFTER THIS BAND GOES THROUGH THE MODELS CONTINUE TO POINT TO A
SHALLOWING OF THE CLOUD LAYER AND LOSS OF ICE AS A MID LEVEL DRY
INTRUSION WORKS ACROSS THE REGION. DRIZZLE WOULD BE THE PCPN
TYPE...OUTSIDE OF THE BAND OF PCPN ASSOCIATED WITH THE WRAP AROUND
ENERGY. THAT SHOULD FALL AS SNOW.
THE CLOUD LAYER DEEPENS AGAIN AND WELCOMES ICE BACK INTO THE PTYPE
EQUATION EARLY THIS EVENING...POST THE SYSTEM/S COLD FRONT. AREAS OF
LIGHT SNOW ARE LIKELY...WITH MINOR ACCUMULATIONS. THIS SNOW
CONTINUES ON MONDAY...AS ALREADY MENTIONED.
OVERALL...ITS A MESS. A LOT GOING ON WITH ONLY SMALL CHANGES IN HOW
WARM IT GETS AND/OR DEPTH OF THE WARM LAYER HAVING A SIGNIFICANT
IMPACT ON WHAT FALLS. THAT DOESN/T EVEN INCLUDE THE YES/NO ICE IN
THE CLOUD QUESTION. IT DOES APPEAR THERE COULD BE A BIT MORE FROZEN
PCPN THEN PREVIOUS FORECASTS HAVE INDICATED. EITHER WAY...THE WINTER
WEATHER ADVISORY LOOKS GOOD AND WILL CONTINUE.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
230 AM CST SUN FEB 10 2013
MODELS REMAIN AT ODDS IN HOW TO HANDLE A NORTHWEST FLOW SHORTWAVE
SLATED TO SPIN ACROSS THE REGION TOWARD THE END OF THE WORK WEEK.
THE GFS MOVES THIS FEATURE IN WED NIGHT...KICKING IT EAST BY THU
NIGHT. THE EC IS WEAKER WITH THIS SHORTWAVE...AND SLOWER...NOT
MOVING IT UNTIL THU. IT MIGHT BE A BIT MORE SOUTH TOO. THE GEM SIDES
MORE TOWARD THE GFS WITH STRENGTH AND POSITIONING...BUT IS
SLOWER...ALSO MOVING IN OVERNIGHT WED. ALL PRODUCE QPF...MORE IN THE
GEM/GFS...AND ALL WOULD BE SNOW. GOOD AMOUNT OF CONSISTENCY IN THE
EC WITH POSITIONING...ALTHOUGH STRENGTH HAS VARIED. THE GFS HAS
JUMPED AROUND. WILL LEAN ON AN EC/CONSENSUS SOLUTION FOR THIS TIME
PERIOD.
THE WEEKEND LOOKS COLDER AS A DEEPER UPPER LEVEL TROUGH IS CARVED
OUT POST THE WED/THU SHORTWAVE. HIGHS IN THE TEENS WITH LOWS CLOSE
TO ZERO LOOK REASONABLE.
&&
.AVIATION...TODAY AND TONIGHT
600 AM CST SUN FEB 10 2013
ONE BAND OF FREEZING RAIN...SLEET...AND SNOW HAS MOVED EAST OF THE
TAF SITES. IN ITS WAKE THERE ARE PATCHY AREAS OF FREEZING DRIZZLE.
ANOTHER AREA OF FREEZING RAIN...SLEET...AND SNOW WILL MOVE INTO
KRST AROUND 10.1530Z AND KLSE AROUND 10.16Z. ONCE THIS BAND MOVES
OUT OF THE AREA...THERE WILL BE JUST SOME PATCHY DRIZZLE FOR THE
AFTERNOON. SCATTERED RAIN AND SNOW SHOWERS WILL MOVE INTO THE
AREA THIS EVENING...AND SNOW SHOWERS TONIGHT. UP TO A HALF INCH OF
SNOW ACCUMULATION IS EXPECTED.
THROUGH THE ENTIRE TIME PERIOD...BOTH CEILINGS AND VISIBILITIES
WILL BE IFR TO MVFR.
&&
.HYDROLOGY...
230 AM CST SUN FEB 10 2013
MORNING RAIN...COUPLED WITH A FEW INCHES OF SNOW PACK...WILL LEAD TO
RUNOFF INTO AREA WATERWAYS. NEARLY A FULL RELEASE AS GROUNDS ARE
FROZEN. EXPECT SOME IN BANK RISES...BUT UNLESS EXPECTED AMOUNTS ARE
SIGNIFICANTLY HIGHER...DON/T ANTICIPATE ANY WIDESPREAD FLOODING
CONCERNS. THE POTENTIAL FOR ICE JAMS WILL HAVE TO BE MONITORED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
230 AM CST SUN FEB 10 2013
WI...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ032>034-041-
042-053>055-061.
WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING TO 6 PM CST THIS
EVENING FOR WIZ017-029-043-044.
MN...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ086-087-094-
095.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ079-088-096.
IA...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR IAZ008>010-018-
019-029.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR IAZ011-030.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...BOYNE
HYDROLOGY....RIECK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1147 AM CST SUN FEB 10 2013
.SHORT TERM /TODAY/...
ANOTHER BAND OF PRECIP DEVELOPING ACROSS
SOUTHWEST IOWA INTO NORTHWEST MISSOURI WILL CONTINUE TO ADVECT NORTH
NORTHEAST THROUGH THE MORNING HOURS. THIS BAND HAS DEVELOPED ALONG
THE 295-300K ISENTROPIC LAYER WITH GOOD MOISTURE TRANSPORT AND
THETA-E ADVECTION PRESENT. LIGHT RAIN/DRIZZLE WILL PERSIST OVER
THE CENTRAL AND SOUTHWEST SECTIONS OF THE FORECAST AREA THROUGH 18Z
OR SOONER BEFORE THE DRY SLOW PUNCHES INTO THE STATE LATE THIS
MORNING. LOWERED POPS OVER THE SOUTHERN HALF OF THE FORECAST AREA
TODAY AS A RESULT OF THE DRY SLOT.
FURTHER NORTH...THE TIMING OF CURRENT MIXED PRECIP BAND AFFECTING
NORTHERN IOWA LOOKS TO PUSH OUT OF THE FORECAST AREA BY AROUND 15Z
THIS MORNING. WARMER AIR CONTINUES TO ADVECT INTO THE STATE AND WILL
SWITCH PRECIP OVER TO ALL RAIN BY 18Z OR LIKELY EARLIER. SOUNDINGS
AT ALO BECOME ALL RAIN BY 15Z...WITH MCW TEETERING BETWEEN
FZRA/SN/RAIN B/T 15-18Z. THE 06Z HRRR HAS INITIALIZED WELL WITH
CURRENT RADAR TRENDS AND ENDS THE BULK OF THE PRECIP BY AROUND 16Z.
STILL LIKELY TO SEE LIGHT FZRA/SLEET AND EVEN SNOW MIX UNTIL THEN
AND WILL KEEP ADVISORY TIMING AS IS.
THE TIMING OF THE COLDER TEMPS AND WRAP-AROUND MOISTURE INTO
NORTHWEST IOWA LOOKS TO BE PAST 21Z AND HAVE RAIN/SNOW MIX MENTIONED
OVER THE NORTH. BUFR SOUNDINGS DEPICTING ICE INTRODUCTION BEGINNING
AS EARLY AS 21Z BUT MORE LIKELY CLOSER TO 00Z MONDAY. HAVE MENTION
OF SN/RA ACROSS THE NORTH PAST 21Z.
.LONG TERM /TONIGHT THROUGH SATURDAY/...
UPPER LOW OVER NORTHWEST IOWA AT THE BEGINNING OF THE PERIOD WILL
SHIFT NORTHEAST INTO THE WESTERN GREAT LAKES BY 12Z MONDAY. THIS
WILL HELP SWING A COLD FRONT THROUGH THE STATE THIS EVENING.
STRONG COLD ADVECTION FROM 850-900 MB WILL DEEPEN MIXING THROUGH
THE EVENING. PROXIMITY MODEL SOUNDING PROFILES REMAIN PERSISTENT
WITH 40 TO 45 KTS AVAILABLE WITHIN THE MIXED LAYER AND SHOULD HAVE
SOME OF THESE WINDS TRANSFER TO THE SFC IN THE FORM OF GUSTS WHILE
SUSTAINED WINDS APPROACH 30 MPH FOR A PERIOD. THEREFORE CONFIDENCE
IS HIGH THAT WIND ADVISORY CRITERIA WILL BE MET OVERNIGHT INTO
EARLY MONDAY MORNING BEGINNING SHORTLY AFTER 00Z IN THE WEST. SOME
UNCERTAINTY THOUGH ON HEADLINE TYPE OVER THE NORTH WHERE SOME SNOW
IS LIKELY. ANY SNOW ACCUMULATIONS THIS EVENING ARE EXPECTED TO BE
AN INCH OR LESS WHICH SHOULD NOT CAUSE A BIG PROBLEM CONSIDERING
THERE IS CURRENTLY NO SNOW COVER ACROSS THE AREA. HOWEVER
POTENTIAL IS THERE FOR SOME CONVECTIVE ELEMENTS TO BE ASSOCIATED
WITH AN AREA OF SNOW THIS AFTERNOON INTO THE EARLY EVENING. IF
THIS INDEED DOES DEVELOP AND HIGHER SNOW AMOUNTS APPROACHING 2
INCHES OCCURS...THEN THE FLAVOR OF HEADLINES ASSOCIATED WITH THE
WIND WOULD NEED TO TRANSITION TO WINTER WEATHER. WITH CURRENT
HEADLINE OUT THROUGH MID MORNING AND SOME UNCERTAINLY WITH TYPE
ACROSS THE NORTH...HAVE OPTED TO NOT ISSUE ADDITIONAL HEADLINES
FOR NOW WHICH WOULD ALLOW THE FOLLOWING SHIFT TO ACCESS TRENDS
BEFORE ISSUING.
THE CANADIAN UPPER WAVE WHICH WILL DIVE INTO THE TROUGH CREATED BY
OUR CURRENT SYSTEM...WILL PASS TO THE SOUTH OF THE AREA TUESDAY
AND TUESDAY NIGHT WITH NO SIGNIFICANT WEATHER FORECAST FOR CENTRAL
IOWA. ANOTHER WAVE WILL DROP SOUTH BY WEDNESDAY NIGHT AND WILL
CARVE A TROUGH OUT ACROSS THE NORTHERN PLAINS WITH ANOTHER PUSH OF
COLDER AIR WITH 850 MB TEMPERATURES DROPPING TO -10C. SOME LIGHT
SNOW POTENTIAL WITH THIS PASSING WAVE. SIGNIFICANT DIFFERENCES
BEYOND THAT WITH THE ECMWF MORE PROGRESSIVE PUSHING THE UPPER
RIDGE INTO THE WESTERN PLAINS WHILE THE GFS DETERMINISTIC AND
ENSEMBLES HOLD THE NORTHWEST FLOW FOR A MORE PROLONGED PERIOD.
&&
.AVIATION...10/18Z
LOW PRESSURE JUST NORTH OF KOFK WILL MOVE TO NORTHEAST WI BY LATE
TONIGHT. SOME IMPROVEMENT IN CONDITIONS ACROSS THE SOUTH HALF OF IA
AS PRONOUNCED DRY SLOT PUSHES INTO THE STATE. KDSM AND KOTM WILL
LIKELY SEE A SEVERAL HOUR PERIOD OF VFR CONDITIONS BEFORE THE MVFR
AND IFR CONDITIONS WRAP AROUND THE BACK SIDE OF THE LOW. SELY WINDS
WILL VEER TO SWLY THIS AFTERNOON. WITH THE PASSAGE OF THE LOW WNWLY
WINDS WILL INCREASE WITH SURFACE GUSTS ABV 30 KTS BY MON MORNING AND
WINDS OF 50 TO 60 KTS WITHIN 3000 FEET OF THE SFC. CLOUD LAYER WILL
GRADUALLY LIFT MON MORNING AS WELL.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MS FEB 13
LONG TERM...DONAVON
AVIATION...MS FEB 13
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
329 PM EST SUN FEB 10 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TONIGHT BEFORE MOVING EAST
OF THE CHESAPEAKE BAY ON MONDAY AFTERNOON. HIGH PRESSURE BUILDS IN
BRIEFLY MONDAY PRIOR TO DEVELOPING LOW PRESSURE APPROACHING THE
REGION WEDNESDAY FROM THE SOUTHEASTERN UNITED STATES. HIGH
PRESSURE THEN MOVES IN BEFORE THE PATTERN BECOMES ACTIVE AGAIN
LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
THE SFC HIGH HAS SHIFTED S AND E OF THE AREA THIS AFTN WHILE LOPRES
ADVANCES NEWD ACROSS THE CENTRAL PLAINS. WAA FROM LGT SLY RETURN
FLOW AROUND THE HIGH COMBINED WITH FILTERED SUNSHINE HAS ALLOWED FOR
A NICE REBOUND IN TEMPS THIS AFTN WITH HIGHS IN THE 40S.
THE LOW WILL TRACK NEWD ACROSS THE UPPER MIDWEST TNGT. WHILE THE
BEST UPPER DYNAMICS ASSOCIATED WITH THIS VERTICALLY-STACKED CYCLONE
WILL REMAIN WELL TO THE NORTH AND WEST OF THE AREA...A STRONG /50-60
KT/ SLY LLVL JET WILL DEVELOP OVER THE ERN SEABOARD TNGT IN ADVANCE
OF THE COLD FRONT. 12Z MODELS REMAIN IN GOOD AGREEMENT WITH TIMING
OF PRECIP...WHICH FOLLOWS CLOSELY THE PASSAGE OF THE H5 RIDGE AXIS
AND ARRIVAL OF SIGNIFICANT ISENTROPIC LIFT/MOISTURE ADVECTION. FCST
REFLECTS A SLIGHTLY FASTER ONSET SINCE OVERRUNNING PRECIP TENDS TO
COMES IN EARLIER THAN MODELS INDICATE.
THE BIGGEST CHALLENGE WITH THE FCST TNGT IS EVALUATING THE THREAT
FOR FREEZING RAIN. MOST GUIDANCE TDA HAS BEEN TOO AGGRESSIVE WITH
MOISTURE RETURN. FOR EXAMPLE THE 12Z NAM...GFS AND LAST FEW RUNS OF
THE RAP HAVE BEEN VERIFYING DEWPOINTS 5-10F TOO HIGH. A SLY BREEZE
AND CLOUDS SHOULD LIMIT AMT OF RADIATIONAL COOLING PRIOR TO PRECIP
THIS EVE. MIN TEMPS LIKELY TO OCCUR SHORTLY ONCE RAIN STARTS AS
EVAPORATIVE COOLING WILL CAUSE TEMPS TO DROP DOWN TO THE WET BULB.
THERE IS STILL AN OUTSIDE CHANCE TEMPS WET BULB DOWN TO FREEZING IN
SHELTERED VLYS NEAR THE MASON-DIXON LINE AND NRN POTOMAC HIGHLANDS.
EVEN IF THIS DOES HAPPEN...RAIN FALLING THRU A 4-6C WARM NOSE DOES
NOT SUPPORT ICE ACCRETION AT THE SFC. MODELS CONTINUE TO SHOW
SIGNIFICANT INTRUSION OF WARM AIR INTO THE BOUNDARY LAYER...WHICH
WOULD LEAD TO RISING TEMPS OVNGT. THERE IS A CONCERN THAT IN-SITU
CAD WILL BE STRONG ENOUGH TO INHIBIT THESE WINDS FROM REACHING THE
BOUNDARY LAYER AND THUS TEMPS DO NOT RISE AS SHARPLY.
PRECIP WILL END DURING THE MRNG AS THE LLVL JET SHIFTS EAST OF THE
AREA. THE COLD FRONT WILL MOVE THRU DURING THE LATE MRNG AND AFTN.
WENT WITH A MORE PESSIMISTIC FCST FOR LOCATIONS EAST OF THE BLUE
RIDGE AND IN NRN MD IN TERMS OF HOW LONG WE HANG ON TO LOW CLOUDS
AND FOG PRIOR TO FROPA. LOWERED MAX TEMPS IN THESE LOCATIONS AS
WELL. MON FEATURES A LARGE SPREAD IN MAX TEMPS...RANGING FROM THE
UPPER 40S NEAR THE MASON-DIXON LINE TO MID 60S IN THE CENTRAL
FOOTHILLS AND CENTRAL SHENANDOAH VLY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
SPRAWLING OCCLUDED LOW WILL MOVE EAST ACROSS SOUTHEASTERN CANADA
MONDAY NIGHT THROUGH TUESDAY AS A ZONAL FLOW DEVELOPS OVER THE ERN
CONUS WITH AN UPPER LOW OVER THE DESERT SOUTHWEST.
MONDAY NIGHT...STRONG WLY FLOW JUST OFF THE DECK TO THE SOUTH OF THE
VERTICALLY STACKED LOW OVER OTTAWA /DUE NORTH FROM DC/. DOWNSLOPING
FLOW WILL CLEAR SKIES WELL EAST OF THE ALLEGHENY FRONT. WLY FLOW IS
NOT IDEAL FOR UPSLOPE SNOW...THEREFORE MAINTAINED LOW CHANCES FOR
SNOW SHOWERS WEST OF THE ALLEGHENY FRONT. DECENT CONFIDENCE ON
MAV/MET BLEND FOR MIN TEMPS OF MID 20S IN THE HIGHLANDS...LOW TO MID
30S EAST TO THE VA/MD PIEDMONT...UPR 30S BALT-WASH METRO AND SRN MD.
TUESDAY...WLY FLOW LIGHTER BUT ENOUGH TO MIX DOWN 20 TO 25 MPH
GUSTS. DOWNSLOPING FLOW AND SCATTERED OR LESS CLOUDS SHOULD RESULT
IN MILD TEMPS. MEX BLEND WITH PREVIOUS GIVES MID TO UPR 40S NRN 3RD
OF THE CWA...MID TO UPR 50S KCHO AND SOUTH /AROUND 50F FOR DC/.
TUESDAY NIGHT...UPR LOW EJECTS EAST FROM DESERT SW WITH OVERRUNNING
HIGH CLOUDS OVERSPREAD AND THICKENING ACROSS THE CWA THROUGH THE
NIGHT. CONTINUE SOME LOW CHANCE POPS FOR THE FAR SWRN ZONES FOR LATE
IN THE NIGHT WHERE A LIGHT WINTRY MIX MAY START BEFORE SUNRISE.
TIMING OF CLOUDS KEY FOR MIN TEMPS WHICH WILL LOOK TO BE AROUND
FREEZING FOR ALL OF THE CWA EXCEPT FOR THE SRN TIER.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
WEDNESDAY INTO WEDNESDAY NIGHT...UPR TROUGH TRACKS ACROSS MID-SOUTH
STATES TO THE CAROLINAS. STILL A DIFFERENCE BETWEEN 12Z GFS/ECMWF
WITH GFS FARTHER NORTH/POSSIBLE SNOW EVENT AND ECMWF STAYING SOUTH
WITH LITTLE PRECIP FOR THE CWA. WITH GEFS MEMBERS STILL DISPLAYING
QUITE A RANGE OF LOCATIONS FOR SFC LOWS...DELAYED POPS AND DECREASED
FOR NRN HALF OF THE CWA AS A COMPROMISE. WILL HAVE TO KEEP WATCHING
THIS ONE WITH SFC CYCLOGENESIS EXPECTED SOMEWHERE NEAR THE LWX CWA.
TEMPERATURES ARE MARGINAL FOR SNOW...BUT DYNAMIC COOLING FROM
DEVELOPMENT WOULD ALLOW FOR SNOW ACROSS HIGHER ELEVATIONS AND IN
STRONGER BANDS. WENT MORE RAINY WEDNESDAY TO A SNOW/SLEET MIX
WEDNESDAY NIGHT. LOW CONFIDENCE AS OF NOW.
ACTIVE PATTERN CONTINUES FOR LONG TERM WITH DEEP ERN CONUS TROUGH
BY FRIDAY. MAINTAINED CHANCE POPS AND CONTINUED SNOW/MIX WORDING
THROUGH END OF FORECAST PERIOD. WILL ALSO HAVE TO WATCH THIS PERIOD
FOR SIGNIFICANT WINTER WEATHER.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS THRU THIS EVE. RA WILL OVERSPREAD THE TERMINALS FROM
WEST TO EAST LATE THIS EVE AND OVNGT. UNTIL A COLD FRONT PASSES
THRU...EXPECT MVFR/IFR CIGS AND VSBYS TO DEVELOP BETWEEN 06Z-09Z AND
CONTINUE THRU THE MRNG EVEN AFTER THE RAIN ENDS. WINDS AT 2K FT AGL
INCREASE TO 40 KT OVNGT. LLWS WAS INCLUDED IN THE 18Z TAFS MAINLY
FOR THE 06Z-14Z PERIOD.
LLWS FROM WLY FLOW EXPECTED MONDAY NIGHT...WLY FLOW GUSTS UP TO 25
KT ON TUESDAY. NEXT PRECIP POSSIBLE MIDWEEK.
&&
.MARINE...
LGT SLY WINDS 5-10 KT WILL GRADUALLY INCREASE THIS AFTN AND EVE. SLY
WINDS CONTINUING TO INCREASE EXPECT TO REACH SCA THRESHOLD IN THE
MAIN STEM OF THE CHSPK BAY AND LWR TIDAL POTOMAC RVR BY THE ERY
MRNG. THE SCA EXPANDS TO INCLUDE ALL WATERS DURING THE DAY ON MON
WITH WIDESPREAD 20-25 KT EXPECTED.
EXTENDED SCA ACROSS THE WATERS FOR MONDAY NIGHT. SOME GUSTS AROUND
20 KT POSSIBLE...WITH STRONGER WINDS JUST OFF THE SFC. LOW
DEVELOPING IN WEDNESDAY TIMEFRAME AROUND THE CHESAPEAKE BAY REGION
WOULD LEAD TO MORE MARINE WIND HEADLINES.
&&
.TIDES/COASTAL FLOODING...
SLY FLOW WILL CONTINUE TO STRENGTHEN TNGT AND MON. POSITIVE TIDAL
ANOMALIES HAVE INCREASED TDA AND ARE CURRENTLY AROUND THREE-QUARTERS
FT. WILL NEED POSITIVE TIDAL ANOMALIES TO DOUBLE IN ORDER TO CAUSE
MINOR COASTAL FLOODING AT THE MOST SENSITIVE LOCATIONS SUCH AS
ANNAPOLIS AND ALEXANDRIA. CURRENT CBOFS KEEPS LVLS BELOW ADVISORY
THRESHOLD AT ALL LOCATIONS THRU THE NEXT FEW HIGH TIDE CYCLES TNGT
AND AND MON.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 3 AM MONDAY TO 6 AM EST TUESDAY FOR
ANZ531>534-537-539>541-543.
SMALL CRAFT ADVISORY FROM 6 AM MONDAY TO 6 AM EST TUESDAY FOR
ANZ530-535-536-538-542.
&&
$$
SYNOPSIS...BAJ
NEAR TERM...JRK
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BAJ/JRK
MARINE...BAJ/JRK
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1230 PM CST SUN FEB 10 2013
.UPDATE...
UPDATED TO INCLUDE 18Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION.../ISSUED AT 430 AM CST SUN FEB 10 2013/
THE POWERFUL STORM WILL BRING WINTER WEATHER ACROSS THE REGION
TODAY...WITH A BAND OF HEAVY SNOW WITH CONVECTIVE ELEMENTS
EXPECTED TO DEVELOP THIS MORNING AND TRAVERSE THE REGION AS IT
MOVES NORTHWARD TOWARDS LAKES SUPERIOR. SNOW WILL CONTINUE ACROSS
THE WEST THROUGHOUT THE DAY...BUT THE REST OF THE REGION SHOULD
SEE A BREAK DURING THE AFTERNOON HOURS. SOME ADDITIONAL SNOW IS
EXPECTED OVERNIGHT...WITH BLIZZARD CONDITIONS DEVELOPING LATER
TONIGHT ACROSS THE MINNESOTA RIVER VALLEY. LOOKING AHEAD...COOLER
WEATHER WILL SETTLE IN FOR THE UPCOMING WEEK...WITH NO SIGNIFICANT
PRECIPITATION EXPECTED.
TODAY THROUGH MONDAY...AS OF EARLY THIS MORNING...THE WELL
ADVERTISED WINTER STORM WAS TAKING SHAPE ACROSS THE CENTRAL CONUS. IR
IMAGERY TOGETHER WITH RAP13 SURFACE ANALYSIS PLACED THE SURFACE LOW
ACROSS SOUTH CENTRAL NEBRASKA...WITH THREE DISTINCT AREAS OF COLD
CLOUD TOPS FANNING OUT ACROSS THE UPPER MIDWEST. OVER THE NEXT 12
HOURS...ISENTROPIC LIFT WILL INCREASE ACROSS THE CWA...WITH A
FRONTOGENETIC CIRCULATION IN THE H700-500 LAYER AIDING IN THE
ASCENT. A CROSS SECTION FROM OMAHA THROUGH DULUTH DEPICT THIS
VERTICAL MOTION. PERHAPS MOST IMPORTANTLY THE CROSS SECTION ALSO
SHOWS UPRIGHT INSTABILITY VIA THE THETA_E LINES WITHIN THIS LAYER
ON THE LEADING EDGE OF THE DRY SLOT. THIS IS A TEXTBOOK SETUP FOR
THUNDERSNOW...AND THIS ELEVATED INSTABILITY IS CONFIRMED BY
ELEVATED CAPE VALUES OF 50 TO 100J/KG VIA THE SREF/NAM/GFS BUFR
SOUNDINGS AT KFRM/KRWF/KMSP/KEAU. THEREFORE DESPITE THE ABSENCE OF
A DEEP COLD LAYER...INCLUDED SLEET IN THE GRIDS TO TARGET THE
POSSIBILITY OF SOME GRAUPEL WITH THE CONVECTIVE ELEMENTS. THE LAST
FEW RUNS OF THE HRRR HAVE A GOOD HANDLE ON THE RAPID DEVELOPMENT
OF AN AREA OF PRECIP THAT IS NOW LOCATED OVER EASTERN NEBRASKA.
TRIED TO TIME THIS BAND OF HEAVY SNOW IN THE HOURLY WEATHER GRIDS.
IT SHOULD ARRIVE AT FAIRMONT BY 11/12Z...AND REACH THE METRO AREA
AND ST CLOUD AROUND 15/16Z...AND IMPACT RICE LAKE/EAU CLAIRE
AROUND 16/17Z. FURTHER WEST MODERATE TO HEAVY SNOW IS EXPECTED
MOST OF THE DAY AS A TROWEL...SEEN IN THE H500-700
THICKNESS...DEVELOPS ACROSS CENTRAL MINNESOTA. AS THE CYCLONE
CONTINUES TO OCCLUDE...THE MEDIUM RANGE AND HIRES MODELS ALL
DEVELOP A SECOND AREA OF PRECIP AHEAD OF THE H500MB VORT MAX
SUNDAY EVENING THAT LAGS THE SURFACE LOW AND TRACKS FROM ROUGHLY
ALBERT LEA...THROUGH RED WING...AND LADYSMITH. THIS WILL DROP
ADDITIONAL SNOW FALL ACROSS SOUTHERN MINNESOTA...WHICH COULD SET
THE STAGE FOR BLIZZARD CONDITIONS EXTENDING AS FAR SOUTH AS I-90
SUNDAY NIGHT THROUGH MONDAY. BUFR FORECAST SOUNDINGS AT FAIRMONT
FROM BOTH THE GFS AND NAM SHOW DIFFERENTIAL COLD AIR ADVECTION
DESTABILIZING THE BOUNDARY LAYER SUNDAY NIGHT...WITH WINDS OF 40
TO 45KTS ATOP THE MIXED LAYER...AS WELL AS SATURATION AND WEAK
LIFT WITHIN THE DEEP DENDRITIC ZONE. IF THE SNOWFALL FORECAST PANS
OUT ACROSS SOUTHERN MINNESOTA TODAY AND THE DITCHES ARE
FULL...THAN HAVE HIGH CONFIDENCE THAT THE BLIZZARD WARNING WILL
NEED TO BE EXTENDED SOUTH LASTING THROUGH MONDAY AFTERNOON. GIVEN
THE CURRENT COMPLEX HEADLINE SITUATION...HAVE OPTED TO JUST EXTEND
THE WINTER WEATHER ADVISORY OUT IN TIME THROUGH MONDAY AFTERNOON
SINCE THE BLIZZARD CONDITIONS WOULDN/T DEVELOP UNTIL SUNDAY NIGHT.
MONDAY NIGHT THROUGH FRIDAY...NORTHWEST FLOW WILL DEVELOP ACROSS THE
REGION WITH A SURFACE HIGH BUILDING OVER THE UPPER MIDWEST IN THE
WAKE OF THE STORM. LEE SIDE WARMING OVER THE CANADIAN PLAINS WILL
KEEP THE COLDEST AIR ACROSS HUDSON BAY. A CLIPPER SYSTEM WILL MOVE
ACROSS THE REGION MID WEEK AND BRING SOME LIGHT SNOW. POPS WILL
LIKELY HAVE TO BE ADJUSTED UP FOR THIS SYSTEM IF IT REMAINS ON
COURSE. ANOTHER SURGE OF ARCTIC AIR WILL FOLLOW BEHIND THIS
CLIPPER...WITH SUB ZERO LOW TEMPERATURES POSSIBLE BY THE END OF THE
WEEK.
&&
.AVIATION.../18Z TAF ISSUANCE/
SIGNIFICANT WINTER STORM OVER THE AREA CONTINUES. ALL MN TAF SITES
HAVE CHANGED OVER TO SNOW OF VARYING INTENSITIES WHILE THE WI TAF
SITES ARE STILL DEALING WITH THE VARIED WINTRY P-TYPES. WILL LOOK
FOR THEIR CHANGEOVER TO OCCUR BY AROUND 20Z. NEXT COMPLICATION
COMES WITH THE DRY SLOT MOVING UP FROM SRN MN. THIS WILL ALLOW
SNOWFALL TO TAPER OFF TO -SN OR SHSN...IF NOT NOTHING...FOR A 3-4
HR PERIOD BETWEEN ABOUT 21Z-00Z. POSSIBLE TO SEE SOME -FZDZ AS THE
SNOW COMES TO AN END...BUT ICING WILL BE VERY MINIMAL...IF
ANYTHING. WHEN SNOW RESUMES LATER THIS EVENING...EXPECTING IT TO
REMAIN ON THE LIGHT SIDE...VARYING BETWEEN SHSN AND -SN. THERE
STILL MAY BE SOME LIGHT ACCUMULATIONS WITH THIS LATER SNOW BUT THE
BULK OF ACCUMULATIONS FROM THIS SYSTEM OVERALL WILL HAVE OCCURRED
FROM THIS MRNG THRU MID-AFTN. AS THE LOW PRES CENTER SHIFTS NE
ACRS THE AREA THIS EVENING...WINDS WILL SWING ARND THE COMPASS
FROM E TO S TO NW AND REMAIN NW THRU TMRW. IN ADDITION...THE TIGHT
PRES GRADIENT FOLLOWING THIS LOW WILL MAKE FOR A STRONG INCRS IN
WIND SPEEDS TNGT THRU TMRW...SUCH THAT BLSN WILL BE A CONCERN FOR
WRN TAF SITES THRU THE NIGHT. CONDITIONS TRY TO IMPROVE LATE DAY
TMRW WHEN THE SNOWFALL WILL BE NOTICEABLY LIGHTER AND WINDS START
TO DROP OFF.
KMSP...P-TYPE HAS CHANGED OVER TO PREDOMINANTLY SNOW AND THIS IS
EXPECTED TO REMAIN AS SUCH FOR THE DURATION. THE MAIN EXCEPTION IS
WHEN THE DRY SLOT...CURRENTLY FROM WRN THRU SERN MN...SHIFTS NWD
OVER THE TWIN CITIES. AS THE -SN DIMINISHES...THERE MAY BE A BRIEF
PERIOD OF -FZDZ WITH VERY LIMITED ICING. THE PRECIP IS THEN
EXPECTED TO TAKE A 2-3 HR BREAK BETWEEN 20Z-21Z THRU 23Z-00Z.
THERE STILL COULD BE SOME FLURRIES DURG THIS TIME...BUT NOT
ANYWHERE NEAR THE INTENSITY SEEN EARLIER TDA. -SN WILL THEN RESUME
THIS EVENING AND CONTINUE THRU MOST OF THE NIGHT...POSSIBLY
BECOMING BLSN CLOSE TO DAYBREAK AS STRONG NW WINDS OVER WRN MN
SHIFT INTO CENTRAL MN. CONDS WILL THEN TRY TO IMPROVE MID-TO-LATE
DAY TMRW.
/OUTLOOK FOR KMSP/
LATE MON...MVFR WITH -SN. NW WINDS 18G30KTS.
TUE...VFR. W WINDS 5 TO 10 KTS.
WED...VFR. MVFR WITH CHC -SN LATE. SW WINDS 5 TO 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST MONDAY FOR BLUE EARTH-
FARIBAULT-FREEBORN-LE SUEUR-MARTIN-RICE-SCOTT-STEELE-WASECA-
WATONWAN.
WINTER STORM WARNING UNTIL 9 PM CST THIS EVENING FOR BROWN-
CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-NICOLLET-POPE-
REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-YELLOW MEDICINE.
BLIZZARD WARNING FROM 9 PM THIS EVENING TO 6 PM CST MONDAY FOR
BROWN-CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-NICOLLET-
POPE-REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-YELLOW MEDICINE.
WINTER STORM WARNING UNTIL 6 PM CST MONDAY FOR CARVER-MCLEOD-
MEEKER-STEARNS-TODD-WRIGHT.
WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR ANOKA-BENTON-
CHISAGO-HENNEPIN-ISANTI-KANABEC-MILLE LACS-MORRISON-RAMSEY-
SHERBURNE-WASHINGTON.
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR DAKOTA-GOODHUE.
WI...WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR BARRON-POLK-RUSK-
ST. CROIX.
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR CHIPPEWA-DUNN-
EAU CLAIRE-PEPIN-PIERCE.
&&
$$
JPC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
259 PM CST SUN FEB 10 2013
.SHORT TERM...TODAY THROUGH MONDAY NIGHT. MAIN CONCERN DURING
THIS TIME PERIOD WILL BE THE WINDS BEHIND THE SURFACE LOW. OUR
NORTHERN COUNTIES...WHERE SNOWFALL OCCURRED EARLIER TODAY...WILL
LIKELY RUN INTO VISIBILITY RESTRICTIONS AS BLOWING SNOW OCCURS
THROUGH THE EARLY EVENING HOURS. ORD HAS EXPERIENCED VISIBILITIES
BETWEEN ONE AND TWO MILES SINCE ABOUT 18Z TODAY...BUT EARLIER
TODAY CONDITIONS WERE BELOW HALF A MILE. ALSO...THERE WILL BE A
SLIGHT CHANCE FOR SNOW THROUGH THE REMAINDER OF TODAY...MAINLY FOR
OUR NORTHERN COUNTIES.
AT 20Z...THE RAP INDICATED A 500MB LOW APPROXIMATELY CENTERED
OVER SIOUX FALLS SOUTH DAKOTA. THE SURFACE LOW WAS DIRECTLY UNDER
THE UPPER LEVEL LOW...RESULTING IN A STACKED TROUGH WHICH IS NOW
EXITING THE CENTRAL PLAINS. BEHIND THE SURFACE LOW...HEIGHT RISES
ARE RESULTING IN A SHARP PRESSURE GRADIENT OVER THE OUTLOOK AREA.
NORTHWESTERLY WIND SPEEDS OF 30 MPH WERE EXPERIENCED OVER NEARLY
THE ENTIRE CWA. GUSTS WERE REACHING THE MID TO UPPER 40S...WITH
ONLY A COUPLE SITES REACHING 50 MPH. THE WINTER WEATHER ADVISORY
FOR BLOWING SNOW WILL CONTINUE UNTIL 9 PM TONIGHT TONIGHT. THIS
WILL LIKELY NEED TO BE CONVERTED TO A WIND ADVISORY IF
VISIBILITIES RECOVERY LATER TODAY. THE WIND ADVISORY COUNTIES
UNTIL 9 PM...AS MODELS ARE NOT DEPICTING ANY LETTING UP OF THE
PRESSURE GRADIENT BEFORE THEN. THE WIND ADVISORY MAY NEED TO BE
EXTENDED FOR OUR EASTERN COUNTIES IF CONDITIONS DO NO EASE UP
LATER TONIGHT.
WIND SPEEDS WILL BEGIN TO RELAX AFTER MIDNIGHT AS THE PRESSURE
GRADIENT EASES OVER THE REGION. A NORTHWESTERLY WIND COMPONENT WILL
BE REALIZED OVER THE ENTIRE SHORT TERM PERIOD.
HIGH TEMPERATURES FOR TOMORROW WILL BE RELATIVELY CLOSE TO NORMAL
FOR THIS TIME OF YEAR. ON THE OTHER HAND...LOW TEMPERATURES WILL BE
SLIGHTLY ABOVE NORMAL FOR THIS TIME OF YEAR.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY...WEAK ZONAL FLOW IS
EXPECTED ACROSS THE REGION TO BEGIN THE EXTENDED PERIODS AS THE
VIGOROUS UPPER LEVEL LOW THAT MOVED ACROSS THE LOCAL AREA THIS
MORNING APPROACHES THE EASTERN SEABOARD AND A SECOND UPPER LEVEL
LOW TRACKS ACROSS THE DESERT SOUTHWEST. AT THE SAME TIME A WEAK
UPPER LEVEL SHORTWAVE IS EXPECTED TO EXTEND ACROSS THE LOCAL AREA
FROM THE NORTH...PROVIDING AMPLE MID LEVEL CLOUD COVER DURING THE
OVERNIGHT HOURS MONDAY INTO TUESDAY MORNING...BUT WITH MINIMAL
FORCING AND VERY LIMITED LOW LEVEL MOISTURE...DO NO EXPECT ANY
SORT OF PRECIPITATION UNDER THIS SCENARIO.
AS THE AFOREMENTIONED UPPER LEVEL ACROSS THE DESERT SOUTHWEST
MOVES INTO THE SOUTHERN PLAINS TUESDAY AFTERNOON...THE UPPER
LEVEL FLOW PATTERN WILL BECOME MORE AMPLIFIED...AS A RIDGE OF HIGH
PRESSURE WORKS ITS WAY TOWARDS THE WEST COAST. THIS WILL ESTABLISH
A NORTHWESTERLY FLOW ALOFT ACROSS THE NORTHERN AND CENTRAL PLAINS
BY WEDNESDAY...WITH MULTIPLE QUICK PASSING UPPER LEVEL
DISTURBANCES EXPECTED TO TRAVERSE THE PLAINS. WITH THE QUICK
MOVING NATURE OF THESE DISTURBANCES AND DRY LOW LEVELS OF THE
ATMOSPHERE...DO NOT THINK MORE THAN FLURRIES WILL BE REALIZED
THROUGH THE END OF THE WEEK...WITH THE BEST GUEST AT TIMING BEING
DURING THE DAY ACROSS THE NORTHWEST THURSDAY...AND ACROSS ALL
AREAS ON FRIDAY. THE FIRST OF THESE DISTURBANCE WILL BE
ACCOMPANIED BY A SURFACE COLD FRONT...WHICH IS EXPECTED TO KNOCK
TEMPERATURES DOWN 10+ DEGREES F ON THURSDAY...WITH THIS
COOLER...YET SEASONAL AIRMASS THEN EXPECTED TO PERSIST ACROSS THE
LOCAL ARE THROUGH THE END OF THE WEEK. AHEAD OF THE
FRONT...WEDNESDAY AFTERNOON APPEARS TO BE THE NICEST DAY OF THE
WEEK...WITH A LIGHT DOWNSLOPING COMPONENT TO THE WINDS LIKELY
HELPING TEMPERATURES CLIMB TO NEAR 50 DEGREES.
&&
.PREV DISCUSSION... /ISSUED 1149 AM CST SUN FEB 10 2013/
AVIATION...18Z TAF FOR KGRI. LOW PRESSURE AT THE SURFACE WILL
CONTINUE TO TRACK NORTHEAST THROUGH THE CENTRAL PLAINS REGION
TODAY...AND MVFR CONDITIONS WILL PREVAIL THROUGH THE DAY UNTIL
CEILINGS BEGIN TO RISE AROUND MIDNIGHT. WIND SPEEDS WILL BE
ANOTHER ISSUE TODAY AS NORTHWESTERLY SPEEDS AROUND 30 KNOTS WILL
BE REALIZED THROUGH THE EVENING. GUSTS WILL BE CLOSER TO 40 KNOTS
THROUGH THE AFTERNOON AS PRESSURE RISES CONTINUE BEHIND THE
SURFACE LOW...RESULTING IN A STRONG PRESSURE GRADIENT ACROSS SOUTH
CENTRAL NEBRASKA.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR NEZ041-047>049-
060>064-072>077-082>087.
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR NEZ039-
040-046.
KS...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR KSZ005>007-017>019.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1233 PM EST SUN FEB 10 2013
.SYNOPSIS...
A FRONT WILL BRING A LIGHT WINTRY MIX, INCLUDING FREEZING RAIN
LATE TONIGHT INTO MONDAY MORNING, WITH A TRANSITION TO PLAIN
RAIN MONDAY. MONDAY NIGHT, A COLD FRONT WILL BRING COLDER
TEMPERATURES AND SNOW SHOWERS. SCATTERED SNOW SHOWERS AND
FLURRIES WILL CONTINUE TUESDAY DOWNWIND OF LAKE ONTARIO AND LAKE
ERIE.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
9 AM UPDATE...
EXTENDED THE CLOUDS AND FLURRIES FOR A FEW MORE HOURS. SATELLITE
SHOWING A SHRINKAGE IN COVERAGE. BY NOON THESE LOW CLOUDS WILL BE
GONE BUT HIGH CLOUDS ALREADY SPREADING IN FROM THE SW AHEAD OF THE
NEXT SYSTEM. ADJUSTED HOURLY TEMPERATURES. UNTIL SOME MIXING
HAPPENS THE CLOUDS WILL REMAIN HOLDING TEMPERATURES STEADY THERE.
OUTSIDE THE CLOUD AREAS TEMPERATURES RISING SLOWLY BUT HAVE A LONG
WAY TO GO STARTING BELOW ZERO.
400 AM UPDATE...MADE MINOR TWEAKS MAINLY TO CLD COVER AND TEMPS
ERLY THIS MORNING AS LOW CLDS STUBBORNLY HANG ON DOWNWIND OF LAKE
ONTARIO. I SUSPECT THESE CLDS WILL DISSIPATE AFTER SUNRISE. ALSO
HAVE A FEW FLURRIES FROM THESE CLOUDS AS SURFACE TEMPS ARE CLOSE
TO THE MAX ICE CRYSTAL GROWTH RATE...SUGGESTING ANY OROGRAPHIC
LIFTING CAN EASILY SQUEEZE OUT A FLURRY OR TWO.
PREVIOUS DISCUSSION BELOW FROM 1 AM UPDATE...
IR IMAGERY AND GOES 11-3.9 MICRON IMAGERY SHOWS PESKY LOW LAKE
EFFECT CLOUDS HANGING ON UNDER A SHARP VERY LOW-LEVEL INVERSION
WITHIN A SHALLOW NORTHWEST FLOW IN EC NY. KBGM 88D VWP SHOWS A
340-350 DEGREE WIND AT 10 KTS ABT 500 FEET AGL AND ALMOST LIGHT
AND VARIABLE ABOVE THIS. THIS LOW CLOUD LAYER THAT WAS MAINLY
DOWNWIND OF THE FINGER LAKES AND LAKE ONTARIO WAS SHRINKING AND
WILL CONTINUE TO DO SO AS THE LATEST RAP 925 MB LAYER WINDS
BETWEEEN 6 AND 9Z TURN MORE NORTH TO NORTHEAST AND WEAKEN...LOSING
THE OVERLAKE TRAJECTORIES. IN ADDITION OUR LOCAL WRF MODEL WITH
ITS HOURLY OUTPUT ALSO IS VERY SIMILAR AND DIMINISHES THE LOW CLD
COVER IN A SIMILAR FASHION AS PER THE DRYING OF THE 925 MB LAYER
AS THE 925 MB WINDS SHIFT MORE NRLY AND LOSE LAKE TRAJECTORIES.
HENCE HAVE CLOUDS DIMINISHING FOR THE REMAINDER OF THE EARLY
MORNING HOURS. MINS WILL BE TRICKY GIVING THE WIDE RANGE OF
TEMPERATURES OBSERVED AT PRESENT DUE TO CLD CVR. IN CLD CVR AREAS
TEMPS ARE IN THE TEENS WITH TEMPERATURES RAPIDLY DROPPING TO NEAR
ZERO IN CLR SKY AREAS. I HAVE MINS RANGING FROM SUB ZERO SINGLE
DIGITS MAINLY TO SINGLE DIGITS WHERE CLD CLEAR LATEST IN EC NY.
FOR SUNDAY...SFC HIGH PRESSURE RDG AXIS IS OVHD AT 12Z AND RAPIDLY
SHIFTS EAST DURING THE DAY...REACHING OFFSHORE BY EVENING.
MEANWHILE NEXT STORM WAS BEGINNING TO WORK EASTWARD. THE 850 AND
925 MB WAA BEGINS DURING THE DAY AS SOUTHERLY WINDS
INCREASE...THIS WILL ALSO POP UP AN UPPER LEVEL RDG OVHD DURING
THE DAY SUNDAY. SOME HIGHER CLDS WILL ADVECT IN OVER THE UPR RDG...
BUT THE DEEPER MID LAYER CLDS HOLD OFF MOST OF THE DAY REACHING
WRN NY LATE. I SEE MAINLY CIRRUS OVERSPREADING C NY AND NE PA DURING
AFTERNOON WITH A MILDER DAY IN STORE DUE TO LL WARM ADVECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
ALL 00Z MODELS...INCLUDING THE NAM12...GFS40...CMC AND EURO ALL
TRACK THE NEXT SIGNIFICANT CYCLONE TRACKING INTO WI BY 6Z MONDAY.
AT UPPER LEVELS THERE WAS A LOW OVER THE WESTERN LAKES REGION
WITH A PERSISTENT UPPER LVL RDG OFF THE SE COAST TO THE WRN GULF
COAST. AS A RESULT OF THIS UPPER LEVEL GEOPOTENTIAL FIELD...THERE
WAS A STRONG UPPER LEVEL JET STREAK THAT WILL PUNCH INTO THE OHIO
VALLEY BETWEEN 6Z AND 18Z MONDAY. THIS WILL INDUCED A STRONG
SOUTHERLY LOW-LEVEL JET ARND 850 MB UP INTO NY AND PA TONIGHT/ERLY MON.
THIS LLJ WILL FEATURE STRONG MOISTURE ADVECTION AND RISE
ISENTROPICALLY. ALL MODELS AGREE THAT PRECIP SPREADS FROM WEST TO
EAST ACROSS CENTRAL NY AND NE PA BTWN 6Z AND 12Z MONDAY. WILL RAMP
POPS UP TO CATEGORICAL BY 12Z ALL FORECAST AREA.
NOW TO P-TYPE. INITIALLY TEMPERATURES AND DEWPOINTS MOST OF CWA
WILL BE BELOW FREEZING WITH SUB FREEZING DWPTS AS WELL LATE TONIGHT.
MODEL GUIDC SUGGESTS OUR DOWNSLOPE REGIONS IN THE NRN FINGER LAKES
ACTUALLY REMAIN ABV FREEZING WHICH IS NOT UNUSUAL TONIGHT. SO I WUD
EXPECT STEADY AND SLOWING RISING TEMPERATURES SUNDAY NIGHT REST OF
ZFORECAST AREA. WHEN PRECIP ARRIVES IT WILL BE MAINLY ZR INITIALLY
WITH POSSIBLY SOME IP...BUT WITH 850 MB TEMPS ABV FREEZING DON/T
SEE SNOW. PRECIPITATION WILL RAPIDLY TURN OVER TO PLAIN RAIN
MONDAY DURING THE MORNING MOST OF CWA AS TEMPS WARM ABV FREEZING.
THE LAST HOLD OUTS WILL BE IN THE FAR EASTERN PART OF THE CWA FROM
SULLIVAN CO TO THE UPPER MOHAWK VALLEY WHERE ZR WILL LAST UNTIL
AFTERNOON. ICE AMNTS WILL BE LIGHT...GENERALLY UNDER
.1 INCHES...HOWEVER I SEE SOME AREAS IN THE CATSKILLS TO MOHAWK
VALLEY SEEING MAYBE UP TO .15 INCH. MAIN IMPACT WILL BE TO TRAVEL.
FOR NOW HELD OFF ON ISSUING ANY FLAGS FOR FREEZING RAIN AS NOT SURE
AS TO THE EXTENT OR AREAL COVERAGE OF THE ICING. THERE IS PLENTY
OF TIME AT THIS POINT IN OUR FORECAST AREA SO WILL LET DAY SHIFT
HANDLE. I SUSPECT AN ADVY WILL BE ISSUED FOR A LARGE PART OF THE
FORECAST AREA THIS AFTERNOON FOR LATE TONIGHT/MONDAY MORNING.
THEN BY AFTERNOON MONDAY...RAIN SHIELD ASSOCIATED WITH WARM/MOIST
CONVEYOR BELT IS EAST OF REGION AND THE COLD FRONT WILL SWING THRU
BETWEEN 21Z MON AND 02Z TUE. THIS FEATURE WILL BE ACCOMPANIED BY
CAA AND MAINLY SNOW SHOWERS WHICH WILL MIX WITH RAIN SHOWERS
INITIALLY.
FOR MONDAY NIGHT INTO EARLY TUESDAY...THE LL FLOW IS MORE W-SW
WHICH SHUD DIRECTLY ANY LAKE MOISTURE AND DEVELOPING LES MAINLY N
OF THE BGM FORECAST AREA. H85 TEMPS AT THIS POINT WILL BE MARGINAL
AT BEST SO DOESN/T LOOK LIKE MUCH BEFORE TUE AM IN C NY OR NE PA
OTHER THAN A FEW SNOW SHOWERS OR FLURRIES.
THEN TUE INTO TUE NGT...ANOTHER WAVE AND ASSOCIATED COLD FRONT AND
SURGE OF COLDER AIR PRESSES SOUTH TWD NY AND TURNS THE LL FLOW
MORE W-NW WHICH COMBINED WITH H85 TEMPS DROPPING TO -12C SHUD TRIGGER
SOME LAKE RESPONSE. FOR NOW HAVE POPS IN FOR LES NC NY LATER TUE
INTO TUE NGT. THE NAM HOLDS ONTO THE LES LONGER THRU TUE NGT...GFS
BACKS FLOW QUICKER TUE NGT. NOT SURE EXACTLY ON TIMING THIS FAR
OUT SO PRETTY MUCH WENT WITH SCENARIO THAT KEEPS THE LES IN
LONGER NC NY. NOT LOOKING FOR A MAJOR EVENT. GFS AND NAM SOUNDINGS
FOR SYR SHOW INVERSION BARELY AT 850 MB AND MAX LIFT BELOW THE MAX
GROWTH RATE FOR ICE CRYSTALS. I CUD SEE A FEW INCHES BUT NO
WARNING AMNTS FOR LAKE SNOW BELTS IN NC NY...SO NO LES WATCH. REST OF
FORECAST AREA WILL SEE TYPICAL BKN SC LAYER WITH SCATTERED
FLURRIES OR EVEN SNOW SHOWERS WITH THE DAY/S HEATING. NO ACCUMS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
1230 PM UPDATE...
THE LONG TERM PERIOD BEGINS WITH A SPLIT FLOW PATTERN...BUT A
TRANSITION TO A MORE AMPLIFIED NORTHERN-STREAM-DOMINANT PATTERN
WILL OCCUR AS WE HEAD INTO NEXT WEEKEND. TEMPERATURES NEAR OR
SLIGHTLY ABOVE CLIMATOLOGY AT THE START OF THE PERIOD...WILL
GRADUALLY TREND BACK TO COLDER WITH TIME. GFS AND ECMWF DO NOT
QUITE AGREE ON DETAILS OF HOW QUICKLY OR EVENTFULLY THAT PROCESS
OCCURS. A COLD FRONT OF UNCERTAIN STRENGTH IS EXPECTED TO PASS
SOMETIME AROUND EARLY FRIDAY TO INTRODUCE INITIAL COLDER
AIR...WHICH FOR THE GFS MARKS AN AGGRESSIVE INVASION OF ARCTIC AIR
FOR THE WEEKEND. THE ECMWF MEANWHILE GETS THE ARCTIC IN AS
WELL...EVENTUALLY...BUT IN PIECES BECAUSE IT TAKES LONGER TO BREAK
DOWN THE SOUTHWEST FLOW AHEAD OF THE AMPLIFIED INCOMING TROUGH /SO
IT MAY TAKE UNTIL AFTER THE WEEKEND FOR THE COLDEST TEMPERATURES/.
IN THE GRIDS...FOR NOW I TRIED TO STRIKE A BALANCE BY ALLOWING FOR
TRENDING BELOW CLIMATOLOGY NEXT WEEKEND...BUT NOT AS ABRUPTLY AS
THE 12Z GFS RUN. I ALSO ACCEPTED HPC POPS GENERALLY IN THE 30-50
PCT CHANCE RANGE FRIDAY NIGHT THROUGH SUNDAY...HIGHEST IN CENTRAL
NY DOWNWIND OF LAKES ERIE/ONTARIO...SINCE THERE SHOULD BE SOME
ABILITY FOR LAKE RESPONSES AS THE COLD AIR MAKES ITS WAY IN.
BEFORE ALL THAT ARRIVES...I ONLY HAVE SLIGHT TO LOW CHANCE POPS AT
BEST FROM THE WEAK WAVES OCCASIONALLY SKIMMING THROUGH OUR
PERIPHERY WITHIN THE SPLIT FLOW.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
18Z UPDATE...
HIGH PRESSURE IN CONTROL...KEEPING THINGS VFR THIS AFTERNOON
THROUGH EVENING. HOWEVER...LATE TONIGHT THE HIGH PRESSURE WILL
YIELD TO A QUICK MOVING SYSTEM WHICH WILL BRING MVFR CONDITIONS
FROM A DASH OF WINTRY MIX /INCLUDING FREEZING RAIN/...SPREADING IN
ROUGHLY WSW TO ENE DURING THE 09Z-14Z MONDAY TIME PERIOD. THE
WINTRY MIX WILL CHANGE TO PLAIN RAIN FAIRLY QUICKLY...AND BECOME
SCATTERED RAIN SHOWERS...BUT MVFR CIGS SHOULD REMAIN. FUEL
ALTERNATE THRESHOLD IS EXPECTED TO BE REACHED FOR ALL TERMINALS
EXCEPT KSYR-KRME MONDAY MORNING...AND SOME IFR CIGS POSSIBLE AT
TIMES KBGM-KAVP. ALSO...WHILE NOT INDICATED YET IN TAFS AS
POTENTIAL IS STILL BEING ASSESSED...LOW LEVEL WIND SHEAR IS NOT
OUT OF THE QUESTION AS THE WAVE OF WINTRY MIX/RAIN MOVES THROUGH.
SSW WINDS AT ABOUT THE 2 KFT AGL LEVEL WILL BE REACHING AROUND 50
KTS...BUT WITH CLOUDS AND OVERRUNNING WARM AIR IT MAY BE A GRADUAL
STEPWISE INCREASE FROM THE SURFACE TO THAT LEVEL RATHER THAN AN
ABRUPT ONE. IF LIKELIHOOD OF LLWS THRESHOLD INCREASES...IT MAY BE
ADDED TO SOME TAFS.
.OUTLOOK...
MON AFT...MVFR CIGS/VIS IN SCT -SHRA.
MON NGT/TUE/TUE NGT...SCT MVFR CNTRL NY IN -SHSN...VFR ELSEWHERE.
WED/THU...VFR MOST OF THE TIME...BUT MVFR CIGS AND -SN POSSIBLE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP/TAC
NEAR TERM...DJN/TAC
SHORT TERM...DJN
LONG TERM...MDP
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
231 PM EST SUN FEB 10 2013
.SYNOPSIS...
RAIN TONIGHT. COLD FRONT EARLY MONDAY. HIGH PRESSURE TUESDAY. LOW
PRESSURE PASSES TO THE SOUTH WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
MODELS IN FAIRLY GOOD AGREEMENT WITH THE BAND OF PRECIPITATION
MOVING THROUGH TONIGHT. WILL INCREASE POPS TO 100 PERCENT. WITH
CLOUDS AND WINDS...WILL GO WITH WARMER MOS GUIDANCE FOR LOWS
TONIGHT. COLD FRONT MOVES THROUGH EARLY MONDAY. WITH COLD AIR
LAGGING CONSIDERABLY BEHIND THE FRONT...SHOULD SEE A GOOD DRY SLOT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AREA GETS INTO INCREASINGLY ALIGNED WSW FLOW AS UPPER LEVEL LOW
TRAVERSES GREAT LAKES MON. DEEP LAYER MOISTURE EXITS FIRST THING IN
THE MORNING...AS UPPER LEVEL JET MAX PASSES. THIS WILL LEAD TO
INCREASINGLY MIXED AIR MASS THAT MAY BECOME DRY ADIABATIC ALL THE
WAY TO H7. HAVE WINDS REACHING CRITERIA FOR ADV ONLY FOR HIGHEST
ELEVATIONS SO FAR VIA RUC MOMENTUM MIXING ALGORITHM.
HIGH PRESSURE SLOWLY BUILDS IN ON TUE...ONLY TO RETREAT TUE NT AS
NEXT S/W TROF APPROACHES FROM THE W. ASSOCIATED CONFLUENCE ZONE
SETS UP ACROSS NRN PA AS SFC LOW TRACKS TO THE S...THE GFS/ECMWF
SOLN FAVORED OVER THE NAM12...WHICH IS THE ODD MODEL N. CANADIAN IS
EVEN FURTHER S. HAVE LIMITED LIKELY POPS TO FAR S PORTION OF THE
AREA.
WHILE THIS IS A SYNOPTICALLY CORRECT TRACK FOR SNOW...BORING
PACIFIC AIR MASS IN PLACE AHEAD OF THE SYSTEM LEAVES TEMPERATURES
ONLY MARGINALLY LOW ENOUGH...ESPECIALLY AT THE SFC...GIVING RISE TO
MIXED PRECIPITATION AND EVEN JUST RAIN. HAVE MINIMAL SNOW AMOUNTS
OF JUST OVER AN INCH ON THE CENTRAL MOUNTAINS AS SYSTEM EXITS WED
AFTERNOON...AND VERY LITTLE ICE. TOGETHER WITH POPS MAINLY IN THE
CHANCE RANGE...HAVE NO HWO MENTION WARRANTED AT THIS POINT AS
CONFIDENCE IN CODABLE WINTER EVENT IS QUITE LOW.
BLENDED IN ADJMET FOR TEMPERATURES EARLY ON...THEN ADJMAV / ADJMEX
TOWARD THE END IN LIGHT OF GFS SOLN. THIS KEEPS FCST LARGELY IN
LINE WITH PREVIOUS PACKAGE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
MDL TRENDS CONT TO CLOSE IN ON OP GFS SOLUTIONS AT LEAST REGARDING
S/W TROF ON WED. 12Z ECWMF CONT THE TREND AS WELL. STILL SOME
UNCERTAINTIES WITH SFC LOW TRACK...BUT ALL AGREE AT LEAST SOME
INFLUENCE FROM INVERTED SFC TROUBLE. ELECTED TO RAISE POPS INTO LKLY
ACROSS SW VA AND IN THE WV MTNS...WITH HIGH CHC ACROSS THE LOWLANDS.
APPEARS LLVL TEMPS WILL BE WARM ENOUGH FOR PERHAPS MAINLY RA BLO
2KFT. SYS PULLS OUT QUICKLY WED EVE FOR A RETURN TO DRY WX THU AND
MOST OF FRI.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS THIS AFTERNOON WITH INCREASING SOUTHERLY FLOW. A
FRONTAL BOUNDARY WILL PUSH THROUGH TONIGHT AND PROVIDE RESTRICTIONS
IN LOW CLOUDS AND SHOWERS. CLOUDS WILL CLEAR FROM THE WEST MONDAY
MORNING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: HIGH THIS AFTERNOON...MEDIUM WITH THE FRONT
TONIGHT.
ALTERNATE SCENARIOS: TIMING OF ARRIVAL OF THE RAIN AND LOWER CLOUDS
TONIGHT COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H H H H H H M M M
HTS CONSISTENCY H H H H H H H M M M M H
BKW CONSISTENCY H H H H H H H H H H M M
EKN CONSISTENCY H H H H H H H H H H H M
PKB CONSISTENCY H H H H H H H H H M M M
CKB CONSISTENCY H H H H H H H H H H H M
AFTER 18Z MONDAY...
IFR POSSIBLE AGAIN WEDNESDAY AND WEDNESDAY NIGHT IN LIGHT RAIN OR
SNOW...MAINLY MOUNTAIN COUNTIES.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY
NEAR TERM...RPY
SHORT TERM...TRM
LONG TERM...30
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1213 PM EST SUN FEB 10 2013
.SYNOPSIS...
SOUTHERLY FLOW INCREASES TODAY. PSEUDO WARM FRONT LIFTING NORTH INTO
KENTUCKY TODAY. COLD FRONT PASSES MONDAY. HIGH PRESSURE TUESDAY.
LOW PRESSURE PASSES TO THE SOUTH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
WIDE RANGE OF TEMPERATURES OVERNIGHT...FROM NEAR 10 DEGREES IN THE
COLDEST MOUNTAIN VALLEYS OF WEST VIRGINIA...TO NEAR 30 ALONG EXPOSED
MOUNTAIN RIDGES.
FIGURING ON HIGH AND MID CLOUDS THICKENING THIS MORNING...WITH SOME
RADAR RETURNS FROM IT...THEN THIN OUT A BIT FOR A PERIOD THIS
AFTERNOON....BEFORE THE DEEPER MOISTURE KNOCKS ON THE DOOR IN OUR
WESTERN COUNTIES BY DARK.
925 MB FLOW INCREASES AT 25 TO 30 KNOTS FROM THE SSE BY 21Z. WILL
INCREASE GUSTS OVER THE MOUNTAIN COUNTIES...INCLUDING SW VIRGINIA
THIS AFTERNOON.
WITH THE FLOW REMAINING MOSTLY SSE THIS EVENING...NOT SE...THINKING
TEMPERATURES IN OUR COLDEST SPOTS IN THE UPPER GREENBRIER VALLEY
WILL DROP TO AROUND 33 OR 34 DEGREES AFTER THE ONSET OF THE RAIN.
SO NOT THINKING READINGS WILL DROP BELOW FREEZING. WILL INSERT A
SLIGHT CHANCE OF SOME POCKETS OF FREEZING RAIN FOR ABOUT 4 HOURS
CENTERED ON MIDNIGHT FOR THOSE LOCATIONS...INCLUDING PORTIONS OF
POCAHONTAS AND EASTERN RANDOLPH COUNTIES. HAVE TEMPERATURES RISING
DURING THE PREDAWN AS WINDS VEER TO SW THERE.
NO BIG CHANGES ON POPS...WITH HOURLY POPS DECREASING QUICKLY BEFORE
12Z IN THE WESTERN LOWLANDS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AREA GETS INTO INCREASINGLY ALIGNED WSW FLOW AS UPPER LEVEL LOW
TRAVERSES GREAT LAKES MON. DEEP LAYER MOISTURE EXITS FIRST THING IN
THE MORNING...AS UPPER LEVEL JET MAX PASSES. THIS WILL LEAD TO
INCREASINGLY MIXED AIR MASS THAT MAY BECOME DRY ADIABATIC ALL THE
WAY TO H7. HAVE WINDS REACHING CRITERIA FOR ADV ONLY FOR HIGHEST
ELEVATIONS SO FAR VIA RUC MOMENTUM MIXING ALGORITHM.
HIGH PRESSURE SLOWLY BUILDS IN ON TUE...ONLY TO RETREAT TUE NT AS
NEXT S/W TROF APPROACHES FROM THE W. ASSOCIATED CONFLUENCE ZONE
SETS UP ACROSS NRN PA AS SFC LOW TRACKS TO THE S...THE GFS/ECMWF
SOLN FAVORED OVER THE NAM12...WHICH IS THE ODD MODEL N. CANADIAN IS
EVEN FURTHER S. HAVE LIMITED LIKELY POPS TO FAR S PORTION OF THE
AREA.
WHILE THIS IS A SYNOPTICALLY CORRECT TRACK FOR SNOW...BORING
PACIFIC AIR MASS IN PLACE AHEAD OF THE SYSTEM LEAVES TEMPERATURES
ONLY MARGINALLY LOW ENOUGH...ESPECIALLY AT THE SFC...GIVING RISE TO
MIXED PRECIPITATION AND EVEN JUST RAIN. HAVE MINIMAL SNOW AMOUNTS
OF JUST OVER AN INCH ON THE CENTRAL MOUNTAINS AS SYSTEM EXITS WED
AFTERNOON...AND VERY LITTLE ICE. TOGETHER WITH POPS MAINLY IN THE
CHANCE RANGE...HAVE NO HWO MENTION WARRANTED AT THIS POINT AS
CONFIDENCE IN CODABLE WINTER EVENT IS QUITE LOW.
BLENDED IN ADJMET FOR TEMPERATURES EARLY ON...THEN ADJMAV / ADJMEX
TOWARD THE END IN LIGHT OF GFS SOLN. THIS KEEPS FCST LARGELY IN
LINE WITH PREVIOUS PACKAGE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
MDL TRENDS CONT TO CLOSE IN ON OP GFS SOLUTIONS AT LEAST REGARDING
S/W TROF ON WED. 12Z ECWMF CONT THE TREND AS WELL. STILL SOME
UNCERTAINTIES WITH SFC LOW TRACK...BUT ALL AGREE AT LEAST SOME
INFLUENCE FROM INVERTED SFC TROUBLE. ELECTED TO RAISE POPS INTO LKLY
ACROSS SW VA AND IN THE WV MTNS...WITH HIGH CHC ACROSS THE LOWLANDS.
APPEARS LLVL TEMPS WILL BE WARM ENOUGH FOR PERHAPS MAINLY RA BLO
2KFT. SYS PULLS OUT QUICKLY WED EVE FOR A RETURN TO DRY WX THU AND
MOST OF FRI.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS THIS AFTERNOON WITH INCREASING SOUTHERLY FLOW. A
FRONTAL BOUNDARY WILL PUSH THROUGH TONIGHT AND PROVIDE RESTRICTIONS
IN LOW CLOUDS AND SHOWERS. CLOUDS WILL CLEAR FROM THE WEST MONDAY
MORNING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: HIGH THIS AFTERNOON...MEDIUM WITH THE FRONT
TONIGHT.
ALTERNATE SCENARIOS: TIMING OF ARRIVAL OF THE RAIN AND LOWER CLOUDS
TONIGHT COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H H H H H H M M M
HTS CONSISTENCY H H H H H H H M M M M H
BKW CONSISTENCY H H H H H H H H H H M M
EKN CONSISTENCY H H H H H H H H H H H M
PKB CONSISTENCY H H H H H H H H H M M M
CKB CONSISTENCY H H H H H H H H H H H M
AFTER 18Z MONDAY...
IFR POSSIBLE AGAIN WEDNESDAY AND WEDNESDAY NIGHT IN LIGHT RAIN OR
SNOW...MAINLY MOUNTAIN COUNTIES.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/TRM
NEAR TERM...KTB
SHORT TERM...TRM
LONG TERM...30
AVIATION...RPY
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1150 AM CST SUN FEB 10 2013
.UPDATE...
18Z AVIATION DISCUSSION UPDATED BELOW.
ABUNDANT WAA SNOW WRAPPING INTO THE REGION LATE THIS MORNING ALONG
WITH DEFORMATION ZONE INCREASING ON SATELLITE WITH COOLING TOPS.
RADAR WAS ALSO IMPRESSIVE IN SHOWING NEW DEVELOPMENT FROM THE EAST
THIS MORNING. THE HRRR MODEL SHOWS A GOOD AMOUNT OF PRECIPITATION
CONTINUING THROUGH THE AFTERNOON. HAVE RECEIVED REPORTS OF 4 TO 11
INCHES SO FAR THIS MORNING. THUS...INCREASED SNOWFALL TOTALS FOR
THE STORM WITH 5 TO 12 INCHES OR MORE WEST OF THE JAMES VALLEY
WITH 8 TO 15 INCHES FROM THE JAMES VALLEY AND EAST BY THE TIME THE
SNOW ENDS LATE TONIGHT INTO MONDAY MORNING. ALSO...NORTH WINDS
WILL CONTINUE TO INCREASE ACROSS THE EASTERN PART OF THE REGION
THIS AFTERNOON CREATING BLIZZARD CONDITIONS. ALREADY HAD REPORTS
OF BLIZZARD CONDITIONS OUT WEST ALONG WITH INTERSTATE CLOSERS.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH TUESDAY
WINTER STORM WELL UNDER WAY WITH SFC LOW STRENGTHENING OVER THE
NEBRASKA/KANSAS BORDER. SNOW HAS BEEN MOVING NORTHWARD ACROSS THE
REGION ALL NIGHT WITH UPPER DIFFLUENCE OVER THE REGION. FIRST BAND
OF HEAVY SNOW MOVED THROUGH SEVERAL HOURS AGO AND NEXT HEAVY BAND
ACROSS THE SOUTHEAST CWA MOVING NORTH-NORTHWEST. MODELS STILL
SHOWING VERY IMPRESSIVE FRONTOGENESIS AND LIFT...ALONG WITH COLD
AIR INSTABILITY. SNOWFALL AMOUNTS ACROSS THE AREA ARE ALREADY IN
THE 3 TO 6 INCH RANGE...WITH ABR GETTING CLOSE TO 6 INCHES. WIND
BEGINNING TO INCREASE ACROSS SOUTH CENTRAL SOUTH DAKOTA WITH PIR
SUSTAINED AT 20 KNOTS. EVERYTHING PRETTY MUCH ON TRACK WITH THE
STORM AND FORECAST WAS NOT CHANGED MUCH. STILL EXPECTING THE
HEAVIEST SWATH OF SNOW FROM THE SOUTHWEST CWA NORTHEAST INTO
NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA. THE SNOW SHIELD
HAS MADE IT PRETTY FAR WEST ACTUALLY...WITH THE NORTHWEST CWA
SEEING SNOWFALL. MBG HAS ABOUT 2 TO 3 INCHES AND STILL SNOWING
WITH SELBY AROUND 4 INCHES. INCREASED SNOW TOTALS A BIT FOR NORTH
CENTRAL SD. ALL IN ALL...CURRENT HEADLINES APPEAR THEY WILL WORK
OUT SO NO CHANGES THERE. WINDS STILL EXPECTED TO INCREASE FROM
WEST TO EAST ACROSS THE AREA TODAY...FIRST OVER CENTRAL SOUTH
DAKOTA THIS MORNING WHERE SPEEDS ARE ALREADY BEGINNING TO RISE.
SPEEDS WILL PICK UP IN THE JAMES VALLEY BY LATE MORNING AND EARLY
AFTERNOON...THEN EVENTUALLY OVER FAR EASTERN SOUTH DAKOTA AND WEST
CENTRAL MINNESOTA BY LATE AFTERNOON AND EARLY EVENING. BLOWING AND
DRIFTING SNOW EXPECTED TO CAUSE SIGNIFICANT PROBLEMS ACROSS THE
REGION AS WINDS COMBINE WITH FALLING SNOW AND THE SEVERAL INCHES
OF SNOW ALREADY THIS MORNING. SPINK COUNTY ALREADY ADVISING NO
TRAVEL AND AN LAE PRODUCT WAS SENT OUT FOR THIS SEVERAL HOURS
AGO. STILL CANNOT RULE OUT THUNDERSNOW...BASICALLY OVER THE
SOUTHEAST CWA WHERE BEST INSTABILITY RESIDES. ALREADY HAS SOME
ISOLATED REPORTS OF THUNDERSNOW LAST NIGHT. THIS STORM STILL ON
TRACK TO EXIT THE AREA ON MONDAY...BUT NOT BEFORE AN ENTIRE NIGHT
OF BLOWING AND DRIFTING SNOW. WINDS WILL BEGIN TO DECREASE SLOWLY
FROM WEST TO EAST ACROSS THE AREA ON MONDAY...SO STILL EXPECTING
BLOWING SNOW MOST OF THE DAY ACROSS EASTERN PORTIONS OF THE
FORECAST AREA. MODELS SEEM TO WANT TO END THE SNOW A TAD QUICKER
ON MONDAY SO HAVE FOLLOWED SUIT IN THE FORECAST.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
NO SIGNIFICANT CHANGES MADE TO THE EXTENDED FORECAST GRIDS THIS
MORNING. NORTHWEST FLOW CLIPPER SYSTEMS WILL BE THE ORDER OF THE
DAY IN THE OUT PERIODS...WITH TWO OR THREE CLIPPER-TYPE SHORTWAVES
WORKING SEWD THROUGH THE REGION. POPS/WX MENTION CONTINUES
STARTING IN THE NORTHWEST ZONES WEDNESDAY AND SPREADING TO THE
SOUTHEAST ZONES BY THURSDAY AFTERNOON/EVENING WITH THE FIRST
CLIPPER WAVE. LOW LEVEL THERMAL PROGS SUGGEST WARMER LOW LEVEL AIR
WILL BE WORKING INTO THE REGION TUESDAY NIGHT AND WEDNESDAY.
HOWEVER...WITH ABUNDANT FRESH AND DEEP SNOW COVER OVER THE
CWA...NOT ALL THAT CONFIDENT THAT TRULY WARMER TEMPERATURES WILL
BE REALIZED AT THE SURFACE...PRIOR TO THE NEXT PUSH OF
ARCTIC-SOURCED LOW LEVEL CAA THURSDAY INTO THURSDAY NIGHT. GFS AND
ECMWF SUGGEST LOW LEVEL COLD AIR WILL STICK AROUND INTO SATURDAY.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
A STRONG SURFACE LOW PRESSURE AREA IN NORTHEAST NEBRASKA WILL HEAD
NORTHEAST THROUGH TONIGHT AND BE IN THE GREAT LAKES REGION BY
MONDAY MORNING. LIGHT TO HEAVY SNOWFALL AT TIMES WILL CONTINUE AT
ALL TERMINALS THROUGH THIS EVENING. NORTH WINDS AT 20 TO 30 KNOTS
WITH GUSTS TO 40 KNOTS ARE EXPECTED TO BRING BLIZZARD CONDITIONS
AT ALL TERMINALS INTO THIS EVENING. IFR/MVFR VISIBILITIES AND
CEILINGS ARE EXPECTED AT ALL LOCATIONS. THE SNOW WILL END FROM
WEST TO EAST TONIGHT THROUGH MONDAY MORNING ALONG WITH DECREASING
WINDS. PIR AND MBG WILL BE THE FIRST TO HAVE IMPROVEMENT WITH ABR
AND ATY HAVING IMPROVEMENT LATER TONIGHT AND MONDAY MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...BLIZZARD WARNING UNTIL 6 AM CST /5 AM MST/ MONDAY FOR BUFFALO-
DEWEY-EDMUNDS-FAULK-HAND-HUGHES-HYDE-JONES-LYMAN-MCPHERSON-
POTTER-STANLEY-SULLY-WALWORTH.
BLIZZARD WARNING UNTIL NOON CST MONDAY FOR BROWN-CLARK-CODINGTON-
DAY-DEUEL-GRANT-HAMLIN-MARSHALL-ROBERTS-SPINK.
WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ MONDAY FOR
CAMPBELL-CORSON.
MN...BLIZZARD WARNING UNTIL NOON CST MONDAY FOR BIG STONE-TRAVERSE.
&&
$$
UPDATE...MOHR
SHORT TERM...TMT
LONG TERM...DORN
AVIATION...MOHR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1100 AM CST SUN FEB 10 2013
.UPDATE...
ABUNDANT WAA SNOW WRAPPING INTO THE REGION LATE THIS MORNING ALONG
WITH DEFORMATION ZONE INCREASING ON SATELLITE WITH COOLING TOPS.
RADAR WAS ALSO IMPRESSIVE IN SHOWING NEW DEVELOPMENT FROM THE EAST
THIS MORNING. THE HRRR MODEL SHOWS A GOOD AMOUNT OF PRECIPITATION
CONTINUING THROUGH THE AFTERNOON. HAVE RECEIVED REPORTS OF 4 TO 11
INCHES SO FAR THIS MORNING. THUS...INCREASED SNOWFALL TOTALS FOR
THE STORM WITH 5 TO 12 INCHES OR MORE WEST OF THE JAMES VALLEY
WITH 8 TO 15 INCHES FROM THE JAMES VALLEY AND EAST BY THE TIME THE
SNOW ENDS LATE TONIGHT INTO MONDAY MORNING. ALSO...NORTH WINDS
WILL CONTINUE TO INCREASE ACROSS THE EASTERN PART OF THE REGION
THIS AFTERNOON CREATING BLIZZARD CONDITIONS. ALREADY HAD REPORTS
OF BLIZZARD CONDITIONS OUT WEST ALONG WITH INTERSTATE CLOSERS.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH TUESDAY
WINTER STORM WELL UNDER WAY WITH SFC LOW STRENGTHENING OVER THE
NEBRASKA/KANSAS BORDER. SNOW HAS BEEN MOVING NORTHWARD ACROSS THE
REGION ALL NIGHT WITH UPPER DIFFLUENCE OVER THE REGION. FIRST BAND
OF HEAVY SNOW MOVED THROUGH SEVERAL HOURS AGO AND NEXT HEAVY BAND
ACROSS THE SOUTHEAST CWA MOVING NORTH-NORTHWEST. MODELS STILL
SHOWING VERY IMPRESSIVE FRONTOGENESIS AND LIFT...ALONG WITH COLD
AIR INSTABILITY. SNOWFALL AMOUNTS ACROSS THE AREA ARE ALREADY IN
THE 3 TO 6 INCH RANGE...WITH ABR GETTING CLOSE TO 6 INCHES. WIND
BEGINNING TO INCREASE ACROSS SOUTH CENTRAL SOUTH DAKOTA WITH PIR
SUSTAINED AT 20 KNOTS. EVERYTHING PRETTY MUCH ON TRACK WITH THE
STORM AND FORECAST WAS NOT CHANGED MUCH. STILL EXPECTING THE
HEAVIEST SWATH OF SNOW FROM THE SOUTHWEST CWA NORTHEAST INTO
NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA. THE SNOW SHIELD
HAS MADE IT PRETTY FAR WEST ACTUALLY...WITH THE NORTHWEST CWA
SEEING SNOWFALL. MBG HAS ABOUT 2 TO 3 INCHES AND STILL SNOWING
WITH SELBY AROUND 4 INCHES. INCREASED SNOW TOTALS A BIT FOR NORTH
CENTRAL SD. ALL IN ALL...CURRENT HEADLINES APPEAR THEY WILL WORK
OUT SO NO CHANGES THERE. WINDS STILL EXPECTED TO INCREASE FROM
WEST TO EAST ACROSS THE AREA TODAY...FIRST OVER CENTRAL SOUTH
DAKOTA THIS MORNING WHERE SPEEDS ARE ALREADY BEGINNING TO RISE.
SPEEDS WILL PICK UP IN THE JAMES VALLEY BY LATE MORNING AND EARLY
AFTERNOON...THEN EVENTUALLY OVER FAR EASTERN SOUTH DAKOTA AND WEST
CENTRAL MINNESOTA BY LATE AFTERNOON AND EARLY EVENING. BLOWING AND
DRIFTING SNOW EXPECTED TO CAUSE SIGNIFICANT PROBLEMS ACROSS THE
REGION AS WINDS COMBINE WITH FALLING SNOW AND THE SEVERAL INCHES
OF SNOW ALREADY THIS MORNING. SPINK COUNTY ALREADY ADVISING NO
TRAVEL AND AN LAE PRODUCT WAS SENT OUT FOR THIS SEVERAL HOURS
AGO. STILL CANNOT RULE OUT THUNDERSNOW...BASICALLY OVER THE
SOUTHEAST CWA WHERE BEST INSTABILITY RESIDES. ALREADY HAS SOME
ISOLATED REPORTS OF THUNDERSNOW LAST NIGHT. THIS STORM STILL ON
TRACK TO EXIT THE AREA ON MONDAY...BUT NOT BEFORE AN ENTIRE NIGHT
OF BLOWING AND DRIFTING SNOW. WINDS WILL BEGIN TO DECREASE SLOWLY
FROM WEST TO EAST ACROSS THE AREA ON MONDAY...SO STILL EXPECTING
BLOWING SNOW MOST OF THE DAY ACROSS EASTERN PORTIONS OF THE
FORECAST AREA. MODELS SEEM TO WANT TO END THE SNOW A TAD QUICKER
ON MONDAY SO HAVE FOLLOWED SUIT IN THE FORECAST.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
NO SIGNIFICANT CHANGES MADE TO THE EXTENDED FORECAST GRIDS THIS
MORNING. NORTHWEST FLOW CLIPPER SYSTEMS WILL BE THE ORDER OF THE
DAY IN THE OUT PERIODS...WITH TWO OR THREE CLIPPER-TYPE SHORTWAVES
WORKING SEWD THROUGH THE REGION. POPS/WX MENTION CONTINUES
STARTING IN THE NORTHWEST ZONES WEDNESDAY AND SPREADING TO THE
SOUTHEAST ZONES BY THURSDAY AFTERNOON/EVENING WITH THE FIRST
CLIPPER WAVE. LOW LEVEL THERMAL PROGS SUGGEST WARMER LOW LEVEL AIR
WILL BE WORKING INTO THE REGION TUESDAY NIGHT AND WEDNESDAY.
HOWEVER...WITH ABUNDANT FRESH AND DEEP SNOW COVER OVER THE
CWA...NOT ALL THAT CONFIDENT THAT TRULY WARMER TEMPERATURES WILL
BE REALIZED AT THE SURFACE...PRIOR TO THE NEXT PUSH OF
ARCTIC-SOURCED LOW LEVEL CAA THURSDAY INTO THURSDAY NIGHT. GFS AND
ECMWF SUGGEST LOW LEVEL COLD AIR WILL STICK AROUND INTO SATURDAY.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
A POTENT WINTER STORM HAS DESCENDED UPON CENTRAL AND NORTHEAST
SOUTH DAKOTA THIS MORNING...RESULTING IN ALL VARIETIES OF IFR
CONDITION IN FALLING AND BLOWING SNOW.
VERY POOR FLYING CONDITIONS IN MODERATE TO HEAVY SNOW WILL
PERSIST FOR MUCH OF THE DAY TODAY INTO THIS EVENING OVER THE KABR
AND KATY TERMINALS. BY EARLY THIS EVENING...BLIZZARD CONDITIONS
SHOULD BE COMMENCING AT THESE TWO TERMINALS AS WELL...WITH
SUSTAINED NORTHWEST WINDS OF 25 TO 35 MPH WITH GUSTS TO 45
MPH...PERSISTING RIGHT ON THROUGH TONIGHT INTO MONDAY MORNING.
THE KPIR AND KMBG TERMINALS WILL CONTINUE TO SEE LIGHT TO MODERATE
SNOW THROUGHOUT THE DAY TODAY. THE BLIZZARD CONDITIONS KICK IN BY
MID MORNING AT THESE TWO TERMINALS...WITH SUSTAINED NORTHWEST
WINDS OF 20 TO 40 MPH WITH GUSTS AS HIGH AS 50 MPH...PERSISTING
THROUGH TONIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...BLIZZARD WARNING UNTIL 6 AM CST /5 AM MST/ MONDAY FOR BUFFALO-
DEWEY-EDMUNDS-FAULK-HAND-HUGHES-HYDE-JONES-LYMAN-MCPHERSON-
POTTER-STANLEY-SULLY-WALWORTH.
BLIZZARD WARNING UNTIL NOON CST MONDAY FOR BROWN-CLARK-CODINGTON-
DAY-DEUEL-GRANT-HAMLIN-MARSHALL-ROBERTS-SPINK.
WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ MONDAY FOR
CAMPBELL-CORSON.
MN...BLIZZARD WARNING UNTIL NOON CST MONDAY FOR BIG STONE-TRAVERSE.
&&
$$
UPDATE...MOHR
SHORT TERM...TMT
LONG TERM...DORN
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
400 PM CST SUN FEB 10 2013
.DISCUSSION...
THE COLD FRONT HAS PUSHED OFFSHORE THIS AFTERNOON WITH
TEMPERATURES IN THE MID 60S ACROSS SOUTHEAST TEXAS. SKIES WILL
REMAIN CLOUDY OVERNIGHT AS SOUTHWESTERLY FLOW ALOFT WILL KEEP
PACIFIC MOISTURE STREAMING ACROSS THE REGION. OVERNIGHT LOWS WILL
DROP INTO THE UPPER 40S AND LOWER 50S ACROSS OUR INLAND COUNTIES
TONIGHT WITH LOWS ALONG THE COAST IN THE LOW 60S.
RAIN WILL REMAIN IN THE FORECAST THROUGH EARLY WEDNESDAY.
ISENTROPIC ASCENT ACROSS THE REGION ON MONDAY WILL ALLOW FOR LIGHT
SHOWERS THROUGHOUT THE DAY WHILE ANOTHER UPPER LEVEL DISTURBANCE
APPROACHES THE REGION ON TUESDAY. THIS SYSTEM WILL PRODUCE HIGHER
RAIN CHANCES ACROSS THE REGION BEFORE MUCH COOLER AND DRIER AIR
FILTERS INTO THE REGION ON WEDNESDAY. THIS COOLER AIR WILL BE
REINFORCED BY ANOTHER FRONTAL PASSAGE ON FRIDAY LEADING TO DRY
CONDITIONS AND MORE SEASONABLE TEMPERATURES FOR THE LATTER HALF OF
THE WEEK. 38
&&
.MARINE...
NORTHERLY FLOW IN THE WAKE OF THE COLD FRONT SPREADING SOUTHWARD...A
LITTLE FASTER SOUTH OF MATAGORDA BAY. RAP HAS BEEN HANDLING WINDS
WELL WITH THE 18Z RUN. MIGHT BRIEFLY FLIRT WITH SCEC CONDITIONS
SOUTH OF MATAGORDA BAY TONIGHT. GRADIENT RESPONDS BY INCREASING AND
BECOMING NORTHEASTERLY AS HIGH PRESSURE BUILDS OVER ARKLATEX-
MISSISSIPPI AREA TONIGHT AND MONDAY. SCEC CONDITIONS LOOK MORE
LIKELY ON MONDAY. SHOWERS TONIGHT ALONG THE FRONTAL BOUNDARY THEN AS
S/W MOVING THROUGH TEXAS ON MONDAY EXPECT TO SEE SOME -RA/SHRA OVER
THE UPPER TEXAS COASTAL WATERS MAINLY EARLY MONDAY THROUGH EARLY
AFTERNOON. ANOTHER PACIFIC COLD FRONT MOVES OFF THE COAST TUESDAY
NIGHT BRINGING SCEC CONDITIONS.
TIDES STILL .5 TO 1.5 FEET ABOVE NORMAL AND THIS SHOULD CONTINUE
THROUGH TUESDAY NIGHT THEN FALL BACK TOWARD NORMAL WITH THE NW FLOW.
45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 54 63 53 67 43 / 20 30 30 50 10
HOUSTON (IAH) 58 68 55 68 48 / 20 30 30 50 10
GALVESTON (GLS) 62 67 60 68 60 / 30 30 30 40 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...38
AVIATION/MARINE...45
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
349 PM CST SUN FEB 10 2013
.SHORT TERM...
RELATIVELY QUIET WEATHER CONDITIONS IN THE SHORT TERM PERIOD.
A WEAK FRONT WILL ENTER THE BIG COUNTRY LATE TONIGHT BUT WILL
WASH OUT ACROSS THE AREA ON MONDAY. SUBTROPICAL JET WILL CONTINUE
TO FEED MID AND HIGH LEVEL MOISTURE FROM THE SOUTHWEST ACROSS MAINLY
SOUTHERN SECTIONS OVERNIGHT. THE NAM CONTINUES TO SHOW SOME LIGHT
RAIN SHOWERS DEVELOPING OVER EXTREME SOUTHEAST COUNTIES ON MONDAY IN
AN AREA OF WEAK ISENTROPIC ASCENT/WAA. 3KM WRF AND LATEST RUC ALSO
HINTING AT THIS POSSIBILITY SO WILL KEEP SLIGHT CHANCE POPS INTACT
THIS FORECAST CYCLE. CLOUD COVER WILL LIMIT COOLING ACROSS SOUTHEAST
SECTIONS TONIGHT WITH LOWS MAINLY IN THE LOWER 40S. LIMITED CLOUD
COVER...LIGHT WINDS AND A DRY AIRMASS WILL ALLOW TEMPS TO COOL INTO
THE LOW TO MID 30S ACROSS THE REMAINDER OF THE AREA. MID AND HIGH
CLOUDS WILL CONTINUE TO INCREASE ON MONDAY WITH AFTERNOON HIGHS
RANGING FROM THE LOW TO MID 60S NORTH TO THE MID AND UPPER 60S
SOUTH.
.LONG TERM...
UPPER LOW NEAR THE FOUR CORNERS LATE MONDAY WILL WILL DIG
SOUTHEAST TUESDAY INTO NEW MEXICO. SURFACE TO 850MB LAYER WILL
QUICKLY SATURATE OVER THE ENTIRE CWA BY MIDNIGHT MONDAY
CONCOMITANT WITH AN INTENSIFYING LLJ...40-50KT CENTERED OVER THE
SOUTHWESTERN CWA. THE HEAVIEST RAINFALL ACCUMULATION CHANCES WILL
BE OVER THE BIG COUNTRY ON THE NOSE OF THE LOW LEVEL JET
BEGINNING AROUND MIDNIGHT MONDAY AND LASTING INTO TUESDAY
MORNING. HAVE INCLUDED THE MENTION OF CONVECTIVE ACTIVITY MONDAY
NIGHT THROUGH TUESDAY AS THE COLD FRONT/DRYLINE MOVES EAST
THROUGH THE FORECAST AREA. LATEST SPC CONVECTIVE OUTLOOK MENTIONS
VIA A SEE TEXT THE POSSIBILITY FOR LARGE HAIL FOR OUR AREA BASED
ON SUFFICIENT INSTABILITY AND SHEAR VALUES FOR ELEVATED
SUPERCELLS...AS REFLECTED IN THE LATEST FORECAST SOUNDINGS...WILL
CONTINUE TO EVALUATE THIS POSSIBILITY. PRECIPITATION CHANCES WILL
BE CONFINED TO OUR EASTERN TIER OF COUNTIES BY TUESDAY AFTERNOON
WITH PRECIPITATION ENDING OVER ALL OF THE FORECAST AREA BY TUESDAY
EVENING. TUESDAY MORNING LOWS WILL RANGE FROM THE LOWER 40S TO
AROUND 50 DEGREES AND TUESDAY AFTERNOON HIGHS WILL RANGE FROM THE
MID 50S TO THE MID 60S UNDER CLOUDY SKIES.
AFTERNOON HIGHS AND MORNING LOWS WILL REMAIN NEAR CLIMO THROUGH
THE COMING WEEKEND...GENERALLY IN THE LOWER 60S FOR HIGHS AND THE
MID 30S FOR LOWS. THE NEXT COLD FRONTAL PASSAGE WILL BE LATE
THURSDAY WITH LITTLE IMPACT ON THE FORECAST AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 34 64 46 58 32 / 0 5 60 40 10
SAN ANGELO 32 70 50 64 35 / 0 10 50 10 5
JUNCTION 38 68 45 66 35 / 0 20 50 20 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
24/15
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
256 PM CST SUN FEB 10 2013
.SHORT TERM...THROUGH TUESDAY NIGHT
256 PM CST SUN FEB 10 2013
MAIN FORECAST CONCERN IS WITH THE PRECIPITATION TRENDS TONIGHT AND
MONDAY.
SURFACE ANALYSIS THIS AFTERNOON SHOWS A STRONG AREA OF LOW
PRESSURE NEAR KSUX. LOCAL AND REGIONAL RADARS SHOWING THE MAIN
BAND OF PRECIPITATION AHEAD OF THE LOW EXTENDS FROM NORTHEAST
MINNESOTA ACROSS MUCH OF WISCONSIN. DRY SLOT COMING IN BEHIND THE
BAND WITH DRIZZLE OCCURRING IN IT.
THE UPPER LEVEL LOW OVER SOUTHEAST SOUTH DAKOTA WILL MOVE PAST THE
AREA OVERNIGHT. HOWEVER...THE MAIN FORCING IS ALREADY MOVING PAST
THE AREA WITH THE BAND OF PRECIPITATION. THE PV ADVECTION IN THE
500-300 MB LAYER WILL RAPIDLY DECREASE THIS EVENING AND WITH THE
BEST ISENTROPIC UP GLIDE MOVING OUT AS WELL EXPECT ONLY SOME
DRIZZLE TO BE THE DOMINANT PRECIPITATION TYPE UNTIL THE SURFACE
LOW GOES BY AND THE COLDER AIR STARTS TO MOVE IN. ONCE THE LOW
GOES BY...THE FORCING WILL START TO INCREASE OVERNIGHT AS THE
10.12Z NAM SHOWS THIS SYSTEM HAS A NICE TROWAL ASSOCIATED WITH IT.
THIS IS IN PLACE BETWEEN THE 285K AND 295K SURFACE WHERE THE UP
GLIDE ON THESE SURFACES IS BETWEEN 2 AND 5 UBARS/S. THIS UP GLIDE
COMBINED WITH THE COLDER AIR COMING IN WILL CHANGE THE LIQUID
PRECIPITATION OVER TO LIGHT SNOW DURING THE LATE EVENING AND
OVERNIGHT HOURS. THE LIGHT SNOW SHOULD THEN CONTINUE THROUGH
MONDAY MORNING BEFORE THE TROWAL MOVES AWAY FROM THE REGION MONDAY
AFTERNOON. THE LIGHT SNOW SHOULD REALLY TAPER OFF MONDAY AFTERNOON
AS THIS OCCURS. ACCUMULATIONS TONIGHT AND MONDAY SHOULD GENERALLY
BE AROUND AN INCH WITH POSSIBLY A COUPLE OF INCHES UP IN TAYLOR
COUNTY. THE WINDS ON THE BACK SIDE OF THE SURFACE LOW WILL
INCREASE WITH SUSTAINED WEST TO NORTHWEST WINDS OF 15 TO 30 MPH
EXPECTED OVERNIGHT THROUGH MONDAY. NOT ANTICIPATING THE NEED FOR
AN ADVISORY WITH GUSTS STAYING UNDER 40 MPH.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
256 PM CST SUN FEB 10 2013
NORTHWEST FLOW ALOFT WILL SET UP OVER THE UPPER MIDWEST IN THE
WAKE OF THE CURRENT STORM SYSTEM. THIS WILL ALLOW A SYSTEM TO DROP
INTO THE REGION FOR THE MIDDLE OR END OF THE WEEK. THE MODELS SHOW
VERY LITTLE CONSISTENCY ON THE TIMING OF THIS FEATURE. THE 10.12Z
GFS IS THE FASTEST BRINGING IN WEDNESDAY AFTERNOON WHILE THE
10.12Z GEM IS THE SLOWEST AND STRONGEST AND DOES NOT BRING IT IN
UNTIL THURSDAY NIGHT. UNTIL THESE TIMING DIFFERENCES ARE WORKED
OUT...WILL NEED TO CARRY A MENTION OF PRECIPITATION FROM WEDNESDAY
NIGHT THROUGH FRIDAY WITH THE BEST CHANCES CENTERED ON WEDNESDAY
NIGHT AND THURSDAY. THE SURFACE LOW MAY PASS BY JUST TO THE NORTH
OF THE AREA THURSDAY BRINGING ENOUGH WARM AIR FOR A MIX OF RAIN
AND SNOW ACROSS THE SOUTH WITH LIGHT SNOW EXPECTED ELSEWHERE.
&&
.AVIATION...THROUGH 18Z MONDAY
1130 AM CST SUN FEB 10 2013
MAIN AVIATION CONCERNS ARE IFR TO MVFR AND WINDY CONDITIONS AT
BOTH RST AND LSE TAF SITES THROUGH TAF PERIOD. LATEST 17Z METARS
REPORTING TEMPERATURES IN THE MIDDLE 30S AND RAIN ACROSS MUCH OF
THE AREA. TEMPERATURES SHOULD REMAIN ABOVE FREEZING AND CLIMB INTO
THE MIDDLE TO UPPER 30S AND ALLOW FOR ANY PRECIPITATION TO BE
DRIZZLE OR RAIN THROUGH THE AFTERNOON HOURS TO AROUND 04-06Z
MONDAY AT BOTH TAF SITES. LATEST 10.15Z RAP AND 10.12Z NAM BUFKIT
SOUNDINGS SHOWING NEAR SURFACE BOUNDARY LAYER TO BE SATURATED
THROUGH TAF PERIOD...WITH THE LATEST CEILING HEIGHTS BEING
REPORTED IN THE RANGE OF 400-1300 FEET ACROSS THE REGION. EXPECT IFR
TO LIFR CONDITIONS AT RST AND MVFR TO IFR CONDITIONS AT LSE
THROUGH TAF PERIOD. THE LATEST DETERMINISTIC 10.12Z NAM AND 10.15Z
RAP INDICATE COLD FRONT TO TRACK ACROSS THE AREA THIS EVENING.
WITH A TIGHT PRESSURE GRADIENT ON THE BACKSIDE OF THE COLD
FRONT...WINDS WILL SHIFT TO THE WEST TO NORTHWEST AT BOTH RST AND
LSE TAF SITES BETWEEN 04-06Z MONDAY TIME FRAME AND INCREASE TO 15
TO 20 KNOTS WITH GUST UP TO 25 TO 30 KNOTS. IN ADDITION...COLDER
AIR WILL FILTER IN BEHIND THE COLD FRONT AND CHANGE THE RAIN OR
DRIZZLE TO ALL SNOW ACROSS THE AREA. WITH THE COMBINATION OF SNOW
AND WINDY CONDITIONS...CANNOT RULE OUT THE POSSIBILITY OF SOME
PATCHY BLOWING SNOW AFTER 10Z MONDAY AT RST. FOR NOW HAVE KEPT
MENTION OF BLOWING SNOW OUT OF THE TAF SITES...HOWEVER KEPT
VISIBILITIES IN THE MVFR RANGE.
&&
.HYDROLOGY...
256 PM CST SUN FEB 10 2013
WITH THE BULK OF THE RAINFALL NOW OVER...THE POTENTIAL FOR
FLOODING IS PRETTY LOW. HOWEVER...WILL CONTINUE TO MONITOR STREAMS
AS THE RUN OFF WORKS INTO THE WATER WAYS POSSIBLY CAUSING SOME IN
BANK RISES. ICE JAMS NOT TOTALLY OUT OF THE QUESTION...BUT DO NOT
BELIEVE THERE WILL BE ENOUGH RISES TO BREAK UP THE ICE ON THE
LARGER RIVERS. ICE JAM POTENTIAL SHOULD BE LIMITED TO THE SMALL
STREAMS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
256 PM CST SUN FEB 10 2013
WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ017-
029.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...DTJ
HYDROLOGY....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1143 AM CST SUN FEB 10 2013
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
230 AM CST SUN FEB 10 2013
FORECAST FOCUS IS ON THE STORM SYSTEM THAT SLIDES ACROSS THE REGION
TODAY...WITH CONTINUING PCPN INTO MONDAY.
LATEST WATER VAPOR SATELLITE IMAGERY PLACES THE SHORTWAVE OVER THE
SOUTHERN PLAINS...WITH THE 00Z MODEL RUNS ALL DRIVING IT NORTHEAST
ACROSS THE FORECAST AREA BY THIS EVENING. RELATIVELY WEAK
FRONTOGENETIC FORCING VIA NAM12/RAP LOOKS RESPONSIBLE FOR THE
CURRENT BAND OF LIGHT PCPN RUNNING NORTHWEST-SOUTHEAST FROM SOUTHERN
MN THROUGH IA. THIS WILL CONTINUE TO LIFT NORTHEAST THROUGH THE
MORNING. THE BULK OF THIS SYSTEM/S FORCING IS POST THIS BAND
HOWEVER...WITH THE STRONG LOW LEVEL THERMODYNAMIC LIFT VIA WARM
ADVECTION/ISENTROPIC UPGLIDE ON THE LEADING EDGE OF THE SHORTWAVE
LIFTING ACROSS THE REGION FROM THE LATE MORNING THROUGH THE
AFTERNOON. THE MODELS KEY ON THIS FORCING FOR THE SYSTEM/S MAIN PCPN
BAND. PLENTY OF MOISTURE TO WORK WITH FOR EARLY FEB...WITH A STRONG
PUSH OF 850 MB MOISTURE TRANSPORT ON THE NOSE OF 50 KT LOW LEVEL
JET. PWS ARE NEARLY 300 PERCENT ABOVE NORMAL WITH SREF ANOMALIES
AROUND +3. IN ADDITION...THE FRONTOGENETIC FORCING IS NEARLY UPRIGHT
AT TIMES...PER NORTHEAST-SOUTHWEST RUNNING X-SECTIONS...AND THIS
COUPLED WITH THE NOSE OF THE LOW LEVEL JET COULD RESULT IN SOME
CONVECTION. A CRACK OR TWO OF THUNDER CAN/T BE RULED OUT...MOSTLY TO
THE SOUTH.
THE PCPN BAND MOVES NORTH OF THE FORECAST AREA BY 00Z...WITH THE
STORM SYSTEM/S SFC LOW OVER NORTHERN IA BY THIS TIME. NAM/GFS
CONTINUE TO INDICATE THAT A SMALLER AREA OF PCPN WILL DEVELOP WITH
THE LOW...ASSOCIATED WITH UPPER LEVEL ENERGY BEING WRAPPED HARD
AROUND THE STORM...AND SOME SFC TROUGHINESS RESULTING IN
CONVERGENCE. THIS AREA OF ENHANCED QPF WOULD FALL ACROSS SOUTHEAST
MN THIS EVENING...SHUFFLING ACROSS NORTHERN WI OVERNIGHT.
ELSEWHERE...ENOUGH BROADSCALE LIFT WITH AMPLE SATURATION THAT AREAS
OF LIGHT PCPN ARE LIKELY. WITH THE COLD FRONTAL PASSAGE IN THE
EVENING...EXPECT A TRANSITION FROM RAIN TO SNOW.
THE SNOW WILL LINGER ON MONDAY...WITH AN INVERTED SFC TROUGH HANGING
WEST OF THE EASTWARD MOVING LOW...BITS OF UPPER LEVEL ENERGY...AND
FAVORABLE LOW LEVEL LAPSE RATES HELPING SPARK THE SNOW. THE BETTER
CHANCES WILL LIE MOSTLY ALONG AND NORTH OF I-90...WITH ADDITIONAL
ACCUMULATIONS ON MONDAY OF AN INCH OR LESS.
AS IT HAS APPEARED THE PAST FEW DAYS...THERE APPEARS TO BE 3
DIFFERENT PCPN PHASES WITH THIS STORM SYSTEM...OR PERHAPS 4 NOW.
SFC OBS WITH THE FRONTOGENETIC PCPN BAND MOVING NORTHEAST INDICATES
MOSTLY RAIN RIGHT NOW...ALTHOUGH THE CONVECTIVE NATURE WOULD SUGGEST
THAT ANY HIGH RETURNS COULD BE...OR PERHAPS ARE MORE LIKELY TO
BE...SLEET. RAP BUFKIT SOUNDINGS OVER NORTHEAST IA HAVE A 1-2 C WARM
LAYER...WHICH GRADUALLY DEEPENS. THE ATMOSPHERE CONTINUES TO
WARM...BUT AS IT DOES...THE CLOUDS LOSE THEIR ICE BEHIND THIS FIRST
PCPN BAND. CURRENT IR/SATELLITE CLOUD TEMPS INDICATE THIS AS WELL.
SO...COULD SEE A FREEZING RAIN/SLEET MIX CHANGE OVER TO FREEZING
DRIZZLE FOR EARLY THIS MORNING...ALL SFC TEMP DEPENDENT OF COURSE.
BUT REMEMBER - EVEN AS TEMPS WARM THROUGH THE DAY...ROAD TEMPS ARE
COLDER...MOSTLY IN THE UPPER 20S...AND ICY SPOTS WILL DEVELOP IF
THEY ARE UNTREATED.
THE MAIN BAND OF PCPN...THE BAND THAT WILL BRING MOST OF THE QPF TO
THE FORECAST AREA...IS EXPECTED TO DEVELOP JUST TO THE
SOUTHWEST...MOVING NORTHEAST ACROSS THE REGION LATE
MORNING/AFTERNOON. GOOD PUSH OF LOW LEVEL WARM AIR WITH THIS
PCPN...GENERALLY 1-3 C AT MAX. THIS IS SUGGESTIVE OF ONLY PARTIAL
MELTING...WHICH WOULD RESULT IN SLEET. HOWEVER...THE DEPTH OF THIS
WARM LAYER EXCEEDS 3 KFT IN SOME LOCATIONS - WHICH COULD RESULT IN
FULL MELTING. HOWEVER...THE TRACK OF THE SYSTEM KEEPS IT A BIT
COLDER WEST OF THE MISSISSIPPI RIVER...EVIDENCED IN A WEST-EAST
RUNNING X-SECTION AND BUFKIT SOUNDINGS. NAM12 BUFKIT SOUNDINGS AT
KRST WOULD FAVOR SNOW TO A SNOW/RAIN MIX...SFC TEMP DEPENDENT. NOT
MUCH OF A DENDRITIC SNOW REGION...BUT ITS ISOTHERMAL AROUND 0 C FOR
A FEW HOURS. WOULD EXPECT A WET SNOW WITH LOWER SNOW RATIOS. WILL
HAVE TO TREND FROM WEST TO EAST AND SOUTH TO NORTH WITH PCPN TYPES.
AFTER THIS BAND GOES THROUGH THE MODELS CONTINUE TO POINT TO A
SHALLOWING OF THE CLOUD LAYER AND LOSS OF ICE AS A MID LEVEL DRY
INTRUSION WORKS ACROSS THE REGION. DRIZZLE WOULD BE THE PCPN
TYPE...OUTSIDE OF THE BAND OF PCPN ASSOCIATED WITH THE WRAP AROUND
ENERGY. THAT SHOULD FALL AS SNOW.
THE CLOUD LAYER DEEPENS AGAIN AND WELCOMES ICE BACK INTO THE PTYPE
EQUATION EARLY THIS EVENING...POST THE SYSTEM/S COLD FRONT. AREAS OF
LIGHT SNOW ARE LIKELY...WITH MINOR ACCUMULATIONS. THIS SNOW
CONTINUES ON MONDAY...AS ALREADY MENTIONED.
OVERALL...ITS A MESS. A LOT GOING ON WITH ONLY SMALL CHANGES IN HOW
WARM IT GETS AND/OR DEPTH OF THE WARM LAYER HAVING A SIGNIFICANT
IMPACT ON WHAT FALLS. THAT DOESN/T EVEN INCLUDE THE YES/NO ICE IN
THE CLOUD QUESTION. IT DOES APPEAR THERE COULD BE A BIT MORE FROZEN
PCPN THEN PREVIOUS FORECASTS HAVE INDICATED. EITHER WAY...THE WINTER
WEATHER ADVISORY LOOKS GOOD AND WILL CONTINUE.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
230 AM CST SUN FEB 10 2013
MODELS REMAIN AT ODDS IN HOW TO HANDLE A NORTHWEST FLOW SHORTWAVE
SLATED TO SPIN ACROSS THE REGION TOWARD THE END OF THE WORK WEEK.
THE GFS MOVES THIS FEATURE IN WED NIGHT...KICKING IT EAST BY THU
NIGHT. THE EC IS WEAKER WITH THIS SHORTWAVE...AND SLOWER...NOT
MOVING IT UNTIL THU. IT MIGHT BE A BIT MORE SOUTH TOO. THE GEM SIDES
MORE TOWARD THE GFS WITH STRENGTH AND POSITIONING...BUT IS
SLOWER...ALSO MOVING IN OVERNIGHT WED. ALL PRODUCE QPF...MORE IN THE
GEM/GFS...AND ALL WOULD BE SNOW. GOOD AMOUNT OF CONSISTENCY IN THE
EC WITH POSITIONING...ALTHOUGH STRENGTH HAS VARIED. THE GFS HAS
JUMPED AROUND. WILL LEAN ON AN EC/CONSENSUS SOLUTION FOR THIS TIME
PERIOD.
THE WEEKEND LOOKS COLDER AS A DEEPER UPPER LEVEL TROUGH IS CARVED
OUT POST THE WED/THU SHORTWAVE. HIGHS IN THE TEENS WITH LOWS CLOSE
TO ZERO LOOK REASONABLE.
&&
.AVIATION...THROUGH 18Z MONDAY
1130 AM CST SUN FEB 10 2013
MAIN AVIATION CONCERNS ARE IFR TO MVFR AND WINDY CONDITIONS AT
BOTH RST AND LSE TAF SITES THROUGH TAF PERIOD. LATEST 17Z METARS
REPORTING TEMPERATURES IN THE MIDDLE 30S AND RAIN ACROSS MUCH OF
THE AREA. TEMPERATURES SHOULD REMAIN ABOVE FREEZING AND CLIMB INTO
THE MIDDLE TO UPPER 30S AND ALLOW FOR ANY PRECIPITATION TO BE
DRIZZLE OR RAIN THROUGH THE AFTERNOON HOURS TO AROUND 04-06Z
MONDAY AT BOTH TAF SITES. LATEST 10.15Z RAP AND 10.12Z NAM BUFKIT
SOUNDINGS SHOWING NEAR SURFACE BOUNDARY LAYER TO BE SATURATED
THROUGH TAF PERIOD...WITH THE LATEST CEILING HEIGHTS BEING
REPORTED IN THE RANGE OF 400-1300 FEET ACROSS THE REGION. EXPECT IFR
TO LIFR CONDITIONS AT RST AND MVFR TO IFR CONDITIONS AT LSE
THROUGH TAF PERIOD. THE LATEST DETERMINISTIC 10.12Z NAM AND 10.15Z
RAP INDICATE COLD FRONT TO TRACK ACROSS THE AREA THIS EVENING.
WITH A TIGHT PRESSURE GRADIENT ON THE BACKSIDE OF THE COLD
FRONT...WINDS WILL SHIFT TO THE WEST TO NORTHWEST AT BOTH RST AND
LSE TAF SITES BETWEEN 04-06Z MONDAY TIME FRAME AND INCREASE TO 15
TO 20 KNOTS WITH GUST UP TO 25 TO 30 KNOTS. IN ADDITION...COLDER
AIR WILL FILTER IN BEHIND THE COLD FRONT AND CHANGE THE RAIN OR
DRIZZLE TO ALL SNOW ACROSS THE AREA. WITH THE COMBINATION OF SNOW
AND WINDY CONDITIONS...CANNOT RULE OUT THE POSSIBILITY OF SOME
PATCHY BLOWING SNOW AFTER 10Z MONDAY AT RST. FOR NOW HAVE KEPT
MENTION OF BLOWING SNOW OUT OF THE TAF SITES...HOWEVER KEPT
VISIBILITIES IN THE MVFR RANGE.
&&
.HYDROLOGY...
230 AM CST SUN FEB 10 2013
MORNING RAIN...COUPLED WITH A FEW INCHES OF SNOW PACK...WILL LEAD TO
RUNOFF INTO AREA WATERWAYS. NEARLY A FULL RELEASE AS GROUNDS ARE
FROZEN. EXPECT SOME IN BANK RISES...BUT UNLESS EXPECTED AMOUNTS ARE
SIGNIFICANTLY HIGHER...DON/T ANTICIPATE ANY WIDESPREAD FLOODING
CONCERNS. THE POTENTIAL FOR ICE JAMS WILL HAVE TO BE MONITORED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
230 AM CST SUN FEB 10 2013
WI...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ032>034-041-
042-053>055-061.
WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING TO 6 PM CST THIS
EVENING FOR WIZ017-029-043-044.
MN...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ086-087-094-
095.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ079-088-096.
IA...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR IAZ008>010-018-
019-029.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR IAZ011-030.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...DTJ
HYDROLOGY....RIECK