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

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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

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.

815 AM UPDATE: NO SIG CHANGES ATTM.

FROM THE MID SHIFT BELOW...

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.

.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

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.

OUTLOOK...

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

SHORT TERM...TONIGHT THROUGH MONDAY...

LONG TERM...TUESDAY THROUGH SATURDAY...

GEELHART

.AVIATION...
ISSUED 525 PM CST SAT FEB 9 2013

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.

.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.

.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.

.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.

.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.

.AVIATION...

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.

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...

.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.

JMC

PREV DISCUSSION... /ISSUED 250 AM CST FRI FEB 8 2013/

DISCUSSION...

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...

.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.

.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

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 316 AM CST FRI FEB 8 2013

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

.FIRE WEATHER...
ISSUED AT 316 AM CST FRI FEB 8 2013

.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.

JMC

.PREV DISCUSSION... /ISSUED 250 AM CST FRI FEB 8 2013/

DISCUSSION...

MCGUIRE

.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION

NWS TOPEKA KS

313 AM CST FRI FEB 8 2013

.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...

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

.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

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.

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...

ADK

.PREV DISCUSSION... /ISSUED 903 PM CST THU FEB 7 2013/

UPDATE...

ADK

PREV DISCUSSION... /ISSUED 544 PM CST THU FEB 7 2013/

AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU

ADK

PREV DISCUSSION... /ISSUED 313 PM CST THU FEB 7 2013/

DISCUSSION...

AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU

BILLINGS

.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

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

.Long Term (Saturday Night - Thursday)...
Issued at 300 AM EST Fri Feb 8 2013

.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

.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

UPDATE ISSUED AT 548 PM EST THU FEB 7 2013

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 257 PM EST THU FEB 7 2013

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST THU FEB 7 2013

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1150 PM EST THU FEB 7 2013

.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.

.AVIATION.../00Z TAF ISSUANCE/