Forecast Discussions mentioning any of "HRRR" "RR" "RUC13" "RUC" received at GSD on 12/09/11

AREA FORECAST DISCUSSION

NWS ALBANY NY

557 PM EST WED DEC 7 2011

.SYNOPSIS...
A STORM SYSTEM WILL LIFT NORTHEAST FROM THE DELMARVA REGION THIS
EVENING...TO THE EAST END OF LONG ISLAND AROUND MIDNIGHT...AND
THEN INTO THE GULF OF MAINE THURSDAY MORNING. THIS STORM TRACK
WILL RESULT IN RAIN CHANGING TO SNOW THIS EVENING ACROSS MUCH OF
THE REGION WITH SIGNIFICANT SNOWFALL ACCUMULATIONS OVERNIGHT IN
MANY AREAS. THE HEAVIEST SNOW IS EXPECTED TO FALL ACROSS THE
NORTHERN TACONICS...EASTERN CATSKILLS...BERKSHIRES AND SOUTHERN
GREEN MOUNTAINS. HEAVY RAIN WILL CONTINUE TO FALL OVERNIGHT ACROSS
THE MID HUDSON VALLEY AND LITCHFIELD HILLS.

.NEAR TERM /THROUGH THURSDAY/...
WINTER STORM WARNINGS ARE IN EFFECT FOR TONIGHT FOR THE EASTERN
CATSKILLS...NORTHERN TACONICS...BERKSHIRES AND SOUTHERN GREEN
MOUNTAINS AND WINTER WEATHER ADVISORIES IN EFFECT FOR THE
SOUTHEAST ADIRONDACKS...LAKE GEORGE SARATOGA REGION...EASTERN
MOHAWK VALLEY...SACANDAGA REGION...GREATER CAPITAL DISTRICT AND
CENTRAL TACONICS. A FLOOD WATCH IS IN EFFECT THROUGH THURSDAY
MORNING FOR THE MID HUDSON VALLEY...SOUTHERN TACONICS AND
LITCHFIELD HILLS.

SNOWFALL ACCUMULATIONS ARE GENERALLY EXPECTED TO BE 3 TO 8 INCHES
IN THE ADVISORY AREA AND 5 TO 12 INCHES IN THE WARNING AREA EXCEPT
ACROSS THE CENTRAL AND SOUTHEAST CATSKILLS...NORTHERN BERKSHIRES
AND HIGHER TERRAIN OF THE SOUTHERN GREEN MOUNTAINS WHERE 8 TO 16
INCHES OF SNOW IS EXPECTED. TOTAL RAINFALL AMOUNTS IN THE FLOOD
WATCH AREA ARE EXPECTED TO BE IN THE 1.75 TO 2.25 INCH RANGE.

AS OF 530 PM EST...CLOUD TOPS CONTINUE TO COOL ACROSS THE FA WITH
21Z KALB SOUNDING INDICATING A WARM TONGUE OF 4C AT AROUND 875 MB
WITH THE FREEZING LEVEL AT AROUND 775 MB OR 6.6 KFT. HAVE RECEIVED
A REPORT OF 1 INCH OF SNOW THUS FAR IN CHARLOTTEVILLE IN SCHOHARIE
COUNTY WITH HEAVY WET SNOW AND A TEMP OF 36 DEGREES AT AN
ELEVATION OF AROUND 1500 FEET. EXPECT A RAPID CHANGEOVER TO SNOW
THIS EVENING ACROSS MUCH OF THE FA MAINLY BETWEEN 00Z AND 03Z WITH
VERY HEAVY SNOW EXPECTED TO FALL DURING MUCH OF THE NIGHT BEFORE
TAPERING OFF LATE. THE ONLY AREAS WHICH ARE NOT EXPECTED TO
RECEIVE MUCH SNOW ARE FAR NORTHWEST PORTIONS OF THE FA INCLUDING
THE WESTERN ADIRONDACKS AND WESTERN MOHAWK VALLEY WHERE VERY
LITTLE QPF EXPECTED...NORTHERN FRINGE OF PCPN SHIELD AND FAR
SOUTHEAST PORTION OF FA WHICH WILL REMAIN TOO WARM FOR MUCH IN THE
WAY OF SNOW MAINLY FROM THE MID HUDSON VALLEY EAST TO THE
LITCHFIELD HILLS WHERE A FLOOD WATCH IS IN EFFECT.

MANY FAVORABLE FACTORS FOR HEAVY SNOW ARE IN PLACE ACROSS MUCH OF
THE FA WITH THE MOST SIGNIFICANT FACTORS BEING IMPRESSIVE
FRONTOGENESIS H8-H7 EXTENDING FROM THE CATSKILLS NORTHEAST TO
SOUTHERN VERMONT AT 00Z AND THEN SHIFTING TO AN ORIENTATION FROM
JUST EAST OF THE CAPITAL DISTRICT THROUGH THROUGH THE NORTHERN
BERKSHIRES INTO SOUTHERN VERMONT AT 06Z. AS THE EVENING WEARS ON
THE SNOW GROWTH REGION BECOMES INCREASINGLY MORE FAVORABLE WITH
THE -12 TO -18 C TEMP SLICING THROUGH A REGION OF +20 UBAR/SEC. IN
ADDITION IMPRESSIVE EPV EXISTS IN LOWER LEVELS ESPECIALLY BTWN 00Z
AND 06Z. THE LATEST HRRR COL MAX REFLECTIVITY ALSO INDICATES
IMPRESSIVE BANDED PCPN ESPECIALLY ACROSS THE HIGHER TERRAIN IN THE
WARNING AREA BETWEEN 03Z AND 06Z WITH THE BACK EDGE OF THE PCPN
SHIELD EXITING THE FA FROM WEST TO EAST BETWEEN 08Z AND 10Z.
EXPECT LOW TEMPS TONIGHT TO RANGE FROM THE MID 20S NORTHWEST TO
MID 30S FAR SOUTHEAST.

ON THURSDAY EXPECT IMPROVING CONDITIONS WITH HIGH PRESSURE MOVING
IN AND MAINLY DRY CONDITIONS WITH HIGHS RANGING FROM THE UPPER
20S TO LOWER 30S NORTHWEST TO LOWER 40S FAR SOUTHEAST.

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
THU NT...BACKING LOW LEVEL WINDS SHOULD ALLOW ANY LINGERING SNOW
BANDS/SNOW SHOWERS TO SHIFT NORTHWARD INTO THE WESTERN
ADIRONDACKS...WITH ADDITIONAL ACCUMS POSSIBLE BEFORE INVERSION
HEIGHTS LOWER AND DIMINISH INTENSITY OF ANY SNOWBANDS.
ELSEWHERE...INITIALLY CLEAR TO PARTLY CLOUDY SKIES SHOULD BECOME
MOSTLY CLOUDY LATER AT NIGHT AS MID LEVEL ISENTROPIC LIFT INCREASES
AHEAD OF NEXT APPROACHING SHORTWAVE. EXPECT MINS TO FALL INTO THE
TEENS AND 20S...WARMEST ACROSS VALLEY REGIONS.

FRI-SAT...UPPER LEVEL TROUGH WILL APPROACH FROM THE W...AND PASS
ACROSS FRI NT. A SFC COLD FRONT ASSOCIATED WITH THIS FEATURE WILL
CROSS THE REGION LATE FRI OR FRI EVE...PRECEDED AND ACCOMPANIED BY
SNOW SHOWERS. THEN...BEHIND THE FRONT...BANDS OF SNOW SHOWERS AND
POSSIBLE SNOW SQUALLS WILL BE POSSIBLE...INITIALLY FAVORING PORTIONS
OF THE WESTERN MOHAWK VALLEY/SCHOHARIE VALLEY...THEN GRADUALLY
SHIFTING NORTHWARD INTO THE WESTERN ADIRONDACKS BY SAT. THERE IS
SOME POTENTIAL FOR LOCALLY HEAVY SNOWFALL AMTS WITHIN SOME OF THESE
BANDS...AND WILL MENTION THIS POSSIBILITY IN THE HWO...WITH GREATEST
THREAT ACROSS THE WESTERN ADIRONDACKS. EXPECT FRI MAXES TO REACH THE
30S IN MOST AREAS...EXCEPT AROUND OR INTO THE LOWER 40S WITHIN THE
VALLEYS...WITH 20S ACROSS HIGHER ELEVATIONS. COLDER AIR BEHIND THE
FRONT WILL MOVE IN FOR FRI NT AND SAT...WITH FRI NT MINS IN THE
TEENS AND LOWER 20S...AND SAT MAXES MAINLY IN THE 30S WITHIN
VALLEYS...AND 20S ACROSS HIGHER ELEVATIONS.

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THIS PERIOD WILL BE FAIRLY QUIET AS HIGH PRESSURE BUILDS INTO THE
MID ATLANTIC REGION SATURDAY NIGHT AND DOMINATES OUR WEATHER INTO
THE EARLY PART OF THE COMING WEEK. A CHANCE OF SOME LAKE ENHANCED
SNOW SHOWERS SATURDAY NIGHT...THEN DRY UNTIL TUESDAY NIGHT WHEN A
WEAK BOUNDARY BRINGS ABOUT SOME SNOW AND RAIN SHOWERS WEST OF THE
HUDSON VALLEY WEDNESDAY.

THE PERIOD STARTS OFF CHILLY...LOWS FROM AROUND 10 TO 20 ABOVE ON
SUNDAY MORNING...WITH HIGHS SUNDAY ONLY IN THE UPPER 20S TO THE
MID 30S. TEMPERATURES WILL GRADUALLY MODERATE WITH HIGHS RISING
TO THE UPPER 30S AND LOWER 40S BY TUESDAY AFTERNOON.

FOR THE MOST PART...USED HPC GUIDANCE TO POPULATE THE GRIDS.

.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
WIDESPREAD IFR CONDITIONS ARE EXPECTED THROUGH AT LEAST
08Z/THU...WITH PERHAPS JUST SOME BRIEF IMPROVEMENTS TO MVFR VSBYS AT
TIMES.

RAIN AND DRIZZLE WILL CONTINUE INTO THIS EVENING...WITH SOME PERIODS
OF MODERATE TO HEAVY RAIN POSSIBLE. THEN...A TRANSITION TO WET SNOW
IS TO OCCUR LATER THIS EVENING...ROUGHLY BETWEEN 01Z-03Z/THU AT KGFL
AND KALB...AND NOT UNTIL AFTER 06Z/THU AT KPOU. THE SNOW MAY BE
MODERATE TO HVY IN INTENSITY...ESP AT KALB AND POSSIBLY KPOU.
PRECIPITATION SHOULD DECREASE IN INTENSITY FROM W TO E BETWEEN
07Z-09Z/THU...AND ENDING BY 11Z/THU IN ALL AREAS.

FOR THU...EXPECT MAINLY VFR CONDITIONS...EXCEPT POSSIBLY SOME MVFR
CIGS/VSBY IN ISOLATED SNOW SHOWERS AT KGFL AND KALB LATER IN THE
AFTERNOON.

WINDS WILL REMAIN FROM THE NORTH TO NORTHEAST AT 5-10 KT THIS
AFTERNOON AND EARLY EVENING...THEN SHIFT INTO THE N...THEN NW AND
INCREASE TO 10-20 KT AFTER 05Z/THU. WINDS WILL THEN BACK INTO THE NW
TO W...AND INCREASE TO 15-25 KT AFTER 14Z/THU...WITH SOME GUSTS
POSSIBLY REACHING 30-35 KT AT KALB.

OUTLOOK...
THU NT-SAT...MAINLY VFR...SLIGHT CHC -SHSN. BREEZY.
SUN-MON...VFR...NO SIG WX.

.HYDROLOGY...
A SIGNIFICANT MIXED PRECIPITATION EVENT WAS OCCURRING ACROSS THE
REGION WITH STORM TOTAL LIQUID AMOUNTS FROM LESS THAN A QUARTER
INCH IN NORTHERN HERKIMER COUNTY TO A LITTLE OVER TWO INCHES IN
THE LOWER HUDSON VALLEY OF NEW YORK AND THE LITCHFIELD HILLS OF
CONNECTICUT. OVER COOLER REGIONS SUCH AS THE HIGHER ELEVATIONS OF
THE CATSKILLS...BERKSHIRES...AND GREEN MOUNTAINS OF SOUTHERN
VERMONT A SUBSTANTIAL AMOUNT OF THIS PRECIPITATION IS FORECAST
TO COME AS SNOW. ACROSS OUR SOUTHERNMOST COUNTIES...EASTERN ULSTER
...DUTCHESS...AND LITCHFIELD...MOST OF THE PRECIPITATION WILL
COME AS RAIN AND LOCALLY HEAVY AMOUNTS MAY AMOUNT TO ENOUGH TO
RESULT IN SOME MINOR FLOODING OF ROADS AND PARKING AREAS AND
CAUSE RISES OF SEVERAL FEET ON RIVERS AND STREAMS.

FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH THROUGH THURSDAY MORNING FOR CTZ001-013.
NY...WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR NYZ047-051-
054-058-063.
WINTER WEATHER ADVISORY UNTIL 6 AM EST THURSDAY FOR NYZ039>043-
048>050-052-053-059>061-082>084.
FLOOD WATCH THROUGH THURSDAY MORNING FOR NYZ064>066.
MA...WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR MAZ001-025.
VT...WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR VTZ013-014.
WINTER WEATHER ADVISORY UNTIL 6 AM EST THURSDAY FOR VTZ015.

$$
SYNOPSIS...11
NEAR TERM...11
SHORT TERM...KL
LONG TERM...RCK
AVIATION...KL
HYDROLOGY...RCK

AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

958 PM CST THU DEC 8 2011

.DISCUSSION...
910 PM CST

THE SNOW POTENTIAL CONTINUES FOR THE REMAINDER OF TONIGHT AS
THE CLIPPER SYSTEM BECOMES MORE ENHANCED WITH THE UPPER COLD
TROUGH DIGGING SOUTHWARD INTO THE MIDWEST. THE DRY AIR IN THE LOW
LEVELS WAS EVIDENT ON THIS EVENINGS DVN SOUNDING...WITH STILL
NOTEWORTHY T/TD SPREAD BELOW 710 MB. IN THE PAST HOUR
THOUGH...MULTIPLE SOUTHEAST IA SITES HAVE BEGUN REPORTING SNOW AS
MORE FORCING LIKELY AIDS IN DEEPER MOISTENING OF THE COLUMN. EVEN
CEDAR RAPIDS HAS SEEN SNOW...WHICH IS BASICALLY DUE WEST OF
CHICAGO /IN OTHER WORDS...SUPPORT FOR LIGHT SNOW HAS REACHED THIS
FAR NORTH/. VARIOUS SHORT TERM MODELS AGREE WITH A PRIMARY CORRIDOR
OF SNOW...MAINLY LIGHT LIKELY...DEVELOPING ACROSS CENTRAL
IL...TOWARDS WATSEKA/RANTOUL/CHAMPAIGN AND INTO NORTHERN IN BY OR
SOON AFTER MIDNIGHT. THIS IS IN PLACE WITH SYNOPTIC FORCING...AND
MESOSCALE MOISTURE CONVERGENCE AT 280-285K AND MID-LEVEL
FRONTOGENESIS ON THE 09.00 NAM. THESE FEATURES ARE SOMEWHAT
TRANSIENT THOUGH...AND THE SHORT-LIVED NATURE LIKELY IS ONLY TO
RESULT IN A HALF AN INCH AT THE MOST. THIS IN LINE WITH THE NAM
AND GFS COBB DATA FOR NEARBY LAFAYETTE. ONE TRICKY ASPECT IS
FURTHER NORTH...WHERE THE HRRR HAS CONTINUOUSLY TRIED TO SHOW SNOW
BETWEEN MIDNIGHT AND 3 AM ACROSS THE CENTRAL AND SOUTHERN PORTIONS
OF THE CHICAGO METRO AREA. THIS IS IN TANDEM WITH WHEN THE UPPER
TROUGH/POTENTIAL VORTICITY ANOMALY COMES ACROSS. HAVING ALREADY
SEEN SNOW THIS FAR NORTH OUT TO OUR WEST...CANNOT RULE OUT SNOW
YET IN CHICAGO. HAVE FURTHER TIGHTENED THE POP GRADIENT IN THE
FORECAST FOR THE REST OF TONIGHT...AS WELL AS SLOWED THE
TEMPERATURE DROP THIS EVENING. THE BULK OF THE CONTINENTAL POLAR
AIR MASS WILL OOZE IN VERY LATE TONIGHT INTO FRIDAY.

MTF

//PREV DISCUSSION...
338 PM CST

MAIN CONCERNS FOR THE FORECAST IN THE NEAR TERM REVOLVE AROUND
CHANCES FOR SNOW TONIGHT INTO EARLY FRIDAY MORNING...AS WELL AS A
MUCH COLDER AIR MASS TO DROP SOUTH OVER THE CWA TONIGHT INTO
FRIDAY. LATEST THINKING IS THAT THE POTENTIAL FOR LIGHT SNOW
REMAINS...BUT FOR THIS TO MORE LIKELY OCCUR OVER THE SOUTHERN HALF
OF THE CWA.

A MOSTLY CLOUDY DAY HAS BEEN OBSERVED ACROSS MUCH OF THE CWA AS A
STREAM OF MID LEVEL MOISTURE HAS MOVED EAST THROUGH MUCH OF THE
MIDDLE PART OF THE CONUS TODAY. THIS HAS OCCURRED OUT AHEAD OF
LONG WAVE TROUGH DIGGING SOUTH THROUGH THE NORTHERN PLAINS. WITH
THE ABSENCE OF ANY STRONGER MID/UPPER LEVEL FEATURES PROGRESSING
ZONAL FLOW ALOFT...SURFACE PATTERN REMAINS FAIRLY RELAXED WITH
SURFACE RIDGING JUST SOUTH OF THE CWA. EXPECT CLOUD COVER TO ONLY
INCREASE OVER THE ENTIRE CWA THIS EVENING AS THIS UPPER LEVEL
TROUGH APPROACHES FROM THE NORTH...WITH CHANCES FOR SNOW
INCREASING INTO TONIGHT.

LIGHT SNOW STILL ANTICIPATED TO SHIFT ACROSS THE CWA TONIGHT INTO
EARLY FRIDAY...BUT WITH SOME OF THE PREVIOUSLY MENTIONED CONCERNS
STILL IN PLACE. LATEST MOSAIC RADAR IS SHOWING AN AREA OF LIGHT TO
MODERATE SNOW SLOWLY MOVING EAST ACROSS NEBRASKA AND IOWA THIS
AFTERNOON. THIS AREA OF SNOW IS FORMING IN A WEAK AREA OF MID
LEVEL FRONTOGENETICAL FORCING OUT AHEAD OF AN APPROACHING SHORT
WAVE TROUGH. ALTHOUGH THE LATEST THINKING IS FOR THIS AREA OF SNOW
TO WORK ITS WAY EAST THIS EVENING...NOT THINKING THIS WILL AFFECT
MOST OF THE AREA...IN TERMS OF ACCUMULATION. 12Z UPPER AIR
SOUNDINGS CONTINUE TO SHOW A FAIR AMOUNT OF DRY AIR IN PLACE
ACROSS THE CWA...AND ITS THIS DRIER AIR WHICH WILL BE ONE FACTOR
THAT WILL HELP LIMIT OVERALL SNOWFALL POTENTIAL. THE OTHER FACTOR
WILL BE WITH FORCING ACROSS THE CWA. LOW/MID LEVEL BAROCLINIC ZONE
STILL FORECAST TO MOVE SOUTH ACROSS THE AREA AS A MUCH COLDER AIR
MASS DROPS SOUTH. PREVIOUSLY MODEL RUNS WERE INDICATING AT THE
POTENTIAL FOR SOME WEAK TO MODERATE FORCING IN RESPONSE TO THIS
DIRECT THERMAL CIRCULATION ACROSS THE CWA. ALTHOUGH WITH LATEST
MODEL RUNS...HAVE NOT BEEN OVERLY EXCITED WITH WHAT I HAVE BEEN
SEEING. LOW LEVEL FORCING IS NONEXISTENT WITH ANY MID LEVEL
FORCING INCONSISTENT AND WEAK AT BEST. THE ONLY FORCING THAT
APPEARS TO BE LOCATED ACROSS THE CWA IS TIED TO UPPER LEVEL
DIVERGENCE ASSOCIATED WITH A STRONG UPPER LEVEL JET STREAK. ITS
NOT UNTIL YOU GET A LITTLE FURTHER SOUTH/SOUTHEAST THAT BETTER
FORCING WILL RESIDE...WHICH WILL OCCUR JUST AT OR SOUTH OF THE
SOUTHERN FRINGE OF THE CWA. LOOKING AT VARIOUS HIRES/SREF MODEL
OUTPUT...ALL SIGNALS INDICATE THIS LATEST THINKING.

WITH THIS IN MIND...HAVE LOWERED POPS ONCE AGAIN TODAY...MAINLY
FOR THE SOUTHERN HALF OF THE CWA AS I AM NOT THAT THRILLED FOR THE
IDEA OF ANY GOOD ACCUMULATION. ALTHOUGH...STILL DID LEAVE MENTION
OF SLIGHT CHANCE TO CHANCE POPS FOR LIGHT SNOW ACROSS THE MIDDLE
PORTION OF THE CWA. THE POSSIBILITY DOES REMAIN FOR SOME FLURRIES
OR LIGHT SNOW TO DEVELOP ACROSS THIS AREA...BUT WITH NO
ACCUMULATION EXPECTED. SOUTH OF THE INTERSTATE CORRIDOR...SNOW
AMOUNTS UP TO A HALF AN INCH ARE STILL POSSIBLE BY EARLY FRIDAY
MORNING. ANY LINGERING SNOWFALL TO EXIT BY FRIDAY MORNING WITH
CLOUD COVER TO ERODE FROM THE WEST. A COLD AIR MASS WILL THEN
CONTINUE TO DROP SOUTH OVER THE CWA AS THIS LONG WAVE TROUGH MOVES
OVERHEAD. A CHILLY DAY IN STORE ON FRIDAY WITH HIGHS ONLY IN THE
20S WITH MUCH LOWER TEMPERATURES FORECAST FRIDAY NIGHT. AS SURFACE
RIDGE AXIS SHIFTS OVERHEAD...CALM WINDS AND CLEAR SKIES WILL ALLOW
TEMPERATURES TO FALL...WITH FORECAST LOW TEMPERATURES IN THE
SINGLE DIGITS EXPECTED ACROSS NORTHERN CENTRAL ILLINOIS AND LOWER
TEENS EXPECTED FOR THE REMAINING CWA.

RODRIGUEZ

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 04Z...

*SMALL THREAT OF PERIOD OF FLURRIES/VERY LIGHT SNOW OVERNIGHT.

TRS

//DISCUSSION...UPDATED 00Z...

SHORT WAVE CONTINUES TO MOVE EAST FROM THE CENTRAL PLAINS
EARLY THIS EVENING SPREADING SNOW FROM NEB OVER SW AND S
CENTRAL IA AS WELL AS FAR NW MO. MODELS PROG 500HPA TROUGH
AXIS REACHING MS RIVER VALLEY AT 06Z THEN WEAKENING IT WHILE
A SECOND SHORT WAVE...CURRENTLY TURNING FROM A SOUTH-SOUTHEAST
TO A MORE TRUE SOUTHEAST MOVEMENT OVER THE DAKOTAS REACHES
WESTERN IA...NORTHWEST MO AND SOUTHEAST KS 12Z FRI.

MODEL TRENDS ARE FOR INCREASING FORCING OCCURRING TONIGHT FROM
NORTHERN MO ACROSS CENTRAL IL TO NORTHEAST IND...WHICH IS WERE
LIGHT ACCUMULATING SNOW IS EXPECTED. FURTHER NORTH ACROSS THE
LOCAL TERMINALS SHORT RANGE HIGH RESOLUTION MODELS INDICATING A
CHANCE OF MEASURABLE PRECIPITATION AS FAR NORTH AS ORD OVERNIGHT
AS THE FIRST SHORT WAVE TROUGH APPROACHES THE AREA. SNOW GENERATED
ALOFT WILL BE FIGHTING VERY DRY AIR IN LOW LEVELS WITH SURFACE DEW
POINTS IN THE TEENS GRADUALLY SINKING SOUTH FROM SOUTHERN WI. WITH
FORCING AND MOISTURE AVAILABILITY LIMITED HAVE INTRODUCED A PROB30
FOR LIGHT SNOW AT CHI TERMINALS 09Z-11Z. FEEL THREAT TO ACTUALLY
START AT 08Z BUT CANNOT USE PROB GROUP IN FIRST 9 HOURS OF TAFOR.

IF SNOW DOES OCCUR AT ORD OR MDW IT WILL BE VERY LIGHT WITH
CONDITIONAL SNOWFALL OF A TRACE TO 0.1 INCH OVERNIGHT.

TRS

//ORD AND MDW CONFIDENCE...UPDATED 04Z...

*HIGH CONFIDENCE IN WIND AND CLOUD FORECASTS.

*MODERATE CONFIDENCE NO SNOW OF SIGNIFICANCE OBSERVED AT ORD OR
MDW.

TRS

//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...

*
SATURDAY...VFR.

SUNDAY...VFR.

MONDAY...VFR.

TUESDAY...VFR.

WEDNESDAY...VFR. CHC SHRA DURING NIGHT.
*

TRS

.MARINE...
138 PM CST

COLD AIR WILL CONTINUE TO SPILL ACROSS LAKE MICHIGAN TONIGHT AND ON
FRIDAY AS A SECONDARY PUSH OF COLD AIR OCCURS. THIS COLD
AIR...COMBINED WITH A DECENT PRESSURE GRADIENT FROM AN AREA OF HIGH
PRESSURE BUILDING IN ACROSS THE PLAINS...WILL ALLOW WESTERLY WINDS
OF 15 TO 30 KT TO CONTINUE ACROSS THE LAKE. HOWEVER...THE STRONGEST
WINDS WILL REMAIN ON THE NORTHERN HALF OF THE LAKE.

THE MAIN CONCERN DURING THE FORECAST PERIOD WILL BE FOR LATE
SATURDAY THROUGH SUNDAY NIGHT. IT APPEARS THAT AN AREA OF LOW
PRESSURE WILL TRACK EASTWARD ACROSS SOUTH CENTRAL CANADA. AS THIS
DOES SO...HIGH PRESSURE IS EXPECTED TO DOMINATE ACROSS THE
SOUTHEASTERN UNITED STATES. THESE TWO PRESSURE SYSTEMS LOOK TO SET
UP A STRONG PRESSURE GRADIENT DURING THIS TIME FRAME...WHICH WILL
SUPPORT STRONG SOUTHWESTERLY WINDS. GALE FORCE WINDS AROUND 35 KT
ARE QUITE POSSIBLE ON SUNDAY...ESPECIALLY ON THE NORTH END OF THE
LAKE. THESE SOUTHWEST WINDS WILL CONTINUE INTO NEXT WEEK...BUT LOOK
TO ABATE BY MID WEEK AS A SURFACE RIDGE OF HIGH PRESSURE BUILDS IN
ACROSS THE GREAT LAKES.

KJB

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN CITY IN UNTIL 10 AM SATURDAY.

AREA FORECAST DISCUSSION...UPDATED

NWS CHICAGO/ROMEOVILLE IL

911 PM CST THU DEC 8 2011

.DISCUSSION...
910 PM CST

MTF

.PREV DISCUSSION...
338 PM CST

RODRIGUEZ

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 02Z...

*SMALL THREAT OF PERIOD OF FLURRIES/LIGHT SNOW OVERNIGHT.

TRS

//DISCUSSION...UPDATED 00Z...

IF SNOW DOES OCCUR AT ORD OR MDW IT WILL BE VERY LIGHT WITH
CONDITIONAL SNOWFALL OF A TRACE TO 0.1 INCH OVERNIGHT.

TRS

//ORD AND MDW CONFIDENCE...UPDATED 02Z...

*HIGH CONFIDENCE IN WIND AND CLOUD FORECASTS.

*MODERATE CONFIDENCE NO SNOW OF SIGNIFICANCE OBSERVED AT ORD OR
MDW.

TRS

//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...

*
SATURDAY...VFR.

SUNDAY...VFR.

MONDAY...VFR.

TUESDAY...VFR.

WEDNESDAY...VFR. CHC SHRA DURING NIGHT.
*

TRS

.MARINE...
138 PM CST

KJB

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN CITY IN UNTIL 10 AM SATURDAY.

AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

233 AM CST WED DEC 7 2011

.DISCUSSION...
900 PM CST

AS ANTICIPATED...CLOUDS ARE MAKING IT EXTRA CHALLENGING WITH THE
TEMPERATURE FORECAST TONIGHT. THE CLEARING WAS SHORT-LIVED...WITH
CLOUDS BOTH EXPANDING AND ADVECTING BACK EAST WITHIN AND JUST ON
THE BACKSIDE OF THE LOW-LEVEL RIDGE. AN UPPER LEVEL TROUGH ALOFT
OVER THE AREA IS CONTINUING TO SHEAR OUT...WITH SUPPRESSION
APPARENTLY INCREASING LOOKING AT THE WATER VAPOR SATELLITE. THE
EVENING DVN AND ILX SOUNDINGS DEPICTED A FAIRLY DEEP 3000 FT LAYER
AT SATURATED OR NEAR-SATURATED...AND THERE ARE FEW SIGNS OF HOLES
EXISTING WITHIN THE CLOUD RIBBON. DESPITE THAT...THE BACK EDGE IS
PROGRESSING...LOCATED ABOUT 100 MILES WEST OF THE MISSISSIPPI
RIVER AROUND 9 PM. THE NAM AND RUC ANALYSIS OF 925-850MB MOISTURE
CAPTURE THIS WELL AND THE PROGRESSION OF THIS. THEIR DRYING
FORECAST COMES ACROSS NORTHERN IL FROM 3 AM THROUGH
DAYBREAK...COINCIDENT WITH THEIR DEPICTION OF HIGHER Q-VECTOR
DIVERGENCE /A PROXY FOR THE SUPPRESSION MENTIONED EARLIER/. THE
LAMP GUIDANCE HAS A VERY GOOD HANDLE ON THE STEADY TEMPERATURES
UNDER THE CLOUD COVER AND SHOW A LATE NIGHT DROP...ESPECIALLY IN
THE WESTERN FORECAST AREA. HAVE STEERED THIS AND THE RUC TREND
INTO THE FORECAST. OVERALL...MINIMUMS ARE SLIGHTLY WARMER FOR MOST
PLACES...A FEW DEGREES TOTAL FOR SOUTH AND EAST OF CHICAGO WHICH
SHOULD SEE THE CLOUDS ARRIVE SHORTLY AND LAST ALL THE WAY THROUGH
DAYBREAK.

MTF

PREVIOUS DISCUSSION...
417 PM CDT

SHORT TERM...THIS AFTERNOON THROUGH FRIDAY

MAIN CONCERN THIS PORTION OF THE FORECAST CENTERS ON LIGHT SNOW
CHANCES THURSDAY NIGHT INTO EARLY FRIDAY AND THEN BLAST OF ARCTIC
AIR FRIDAY INTO EARLY SATURDAY.

AFTERNOON WATER VAPOR IMAGERY SHOWS MID LEVEL TROUGHING ACROSS THE
REGION...WHILE AT THE SURFACE...HIGH PRESSURE STRETCHES FROM THE
WESTERN GREAT LAKES SOUTHWEST TO THE SOUTHERN PLAINS. ON VISIBLE
SATELLITE...EVER PRESENT STRATUS ACTUALLY HAS ERODED A BIT THIS
AFTERNOON FROM THE NORTH AS HIGH PRESSURE BUILDS IN. SUSPECT HOWEVER
THAT STRATUS WILL TEMPORARILY RETURN THIS EVENING AS FLOW BECOMES
NORTHERLY THEN WESTERLY. MODEL RH PROGS SHOW PLENTIFUL MOISTURE
BELOW 800 MB UNTIL LATER TONIGHT. THEN EXPECT THE REMAINING OVERCAST
TO ERODE FROM NORTHWEST. WITH CHILLY AIR MASS IN PLACE...TIMING OF
CLEARING TONIGHT WILL HAVE IMPACT ON LOW TEMPERATURES. THINK THAT
SKIES WILL CLEAR ENOUGH BY TOMORROW MORNING SO THAT...ALONG
WITH LIGHT WINDS...TEMPERATURES WILL BE ABLE TO PLUMMET TO THE UPPER
TEENS ACROSS NORTHWEST AND NORTH CENTRAL ILLINOIS. THE
REMAINDER OF THE AREA CAN EXPECT LOW TO MID 20S...WITH UPPER 20S IN
AND NEAR DOWNTOWN CHICAGO. WENT CLOSE TO MAV/MET GUIDANCE FOR LOWS
AND SLIGHTLY COLDER THAN PREVIOUS ISSUANCE.

WEDNESDAY WILL START OUT MOSTLY SUNNY...BUT CLOUDS MAY INCREASE JUST
A BIT IN THE AFTERNOON AS A COLD FRONT SWINGS THROUGH THE AREA
DURING THE AFTERNOON. LOW LEVELS WILL BE EXTREMELY DRY SO NO
PRECIPITATION IS FORECAST WITH THE FROPA. HIGHS WILL TOP OUT NEAR OR
JUST BELOW AVERAGE...LOW 30S OVER NORTH CENTRAL ILLINOIS AND MID 30S
FOR THE REMAINDER OF THE AREA. FROPA WILL SEND REINFORCING SHOT OF
COLDER AIR ACROSS REGION...AS TEMPERATURES COOL AT H85 WEDNESDAY
NIGHT TO ROUGHLY -8C. PRESSURE GRADIENT WILL REMAIN TIGHT ENOUGH TO
KEEP A WESTERLY BREEZE GOING...WITH LOWS LIKELY SIMILAR TO TONIGHT.

THURSDAY WILL BE A FEW DEGREES COOLER THAN WEDNESDAY...WITH CLOUDS
INCREASING FROM THE WEST AS A WAVE DEVELOPS WEST OF THE AREA ALONG
A TIGHT BAROCLINIC ZONE...WITH THE BULK OF ARCTIC AIR OVER THE
NORTHERN PLAINS AND UPPER MIDWEST NORTH OF OUR AREA. ON THURSDAY
NIGHT...DIGGING H5 TROUGH WILL SPAWN A WEAK SURFACE LOW WHICH WILL
TRACK ACROSS THE NORTHERN GREAT LAKES AND SEND AN ARCTIC
FRONTAL BOUNDARY TOWARD THE AREA. THE FRONTOGENETIC FORCED WAVE
ALONG THE ARCTIC FRONT WILL TRACK ALONG THE TIGHTEST THERMAL PACKING
TO NEAR OR OVER OUR AREA. MOST GUIDANCE...WITH THE EXCEPTION
OF THE NAM AND SREF HAVE COME INTO DECENT AGREEMENT ON A BAND OF
LIGHT QPF OVER ALL OF NORTHERN ILLINOIS AND NORTHWEST INDIANA ON
THURSDAY NIGHT INTO EARLY FRIDAY. TIME HEIGHTS AND SOUNDINGS
CONTINUE TO SHOW ADEQUATE SATURATION AND LIFT INTO THE FAVORABLE
DENDRITIC GROWTH AREA. THE RIGHT ENTRANCE REGION OF JET MAY PROVIDE
SOME ENHANCED LIFT. WITH COLD TEMPERATURES IN PLACE...EXPECTING 20:1
RATIO...WHICH WOULD RESULT IN THE FIRST LIGHT ACCUMULATING SNOWFALL
OF THE SEASON FOR MUCH OF THE AREA. AT THIS POINT...POTENTIAL EXISTS
FOR SOME LOCATIONS TO SEE IN EXCESS OF ONE INCH OF SNOWFALL. NOT
HIGH CONFIDENCE YET ON THIS FEATURE...SO DID STAY WITH CHANCE POPS
AS OPPOSED TO HIGHER POPS. IT MAY COME DOWN TO VERY CLOSE TO THE
EVENT UNTIL THE PART OF THE AREA WITH THE BEST FORCING FOR LIGHT
SNOW IS ASCERTAINED. ONCE WAVE QUICKLY SHIFTS EAST THROUGH THE
AREA...THE BIG STORY WILL BE SHARP COLD ADVECTION...WITH MINUS
TEEN TEMPERATURES AT H85 POISED TO POUR INTO AREA. WENT WITH BLENDED
MODEL GUIDANCE FOR LOWS EARLY FRIDAY MORNING...WHICH YIELDS UPPER
TEENS FAR NORTHERN ILLINOIS TO THE LOWER AND MIDDLE 20S FARTHER
SOUTH.

WITH STRONG COLD AIR ADVECTION ONGOING ON FRIDAY...IT WILL BE VERY
DIFFICULT TO RECOVER MUCH FROM THESE LOW TEMPERATURES. MODELS DIFFER
ON HOW COLD WE GET AT H85 AS THERMAL TROUGH REACHES AREA ON FRIDAY.
BUT THE GENERAL RANGE IS ABOUT -15C TO -20C. THUS WENT COLDER THAN
PREVIOUS FORECAST ISSUANCE BY SEVERAL DEGREES FOR FRIDAY...WITH LOW
20S FAR NORTH AND MIDDLE AND UPPER 20S ALONG AND SOUTH OF INTERSTATE
80. SOME LIGHT SNOW MAY LINGER OVER THE EASTERN PORTION OF THE
FORECAST AREA BEFORE SHIFTING EAST BY THE AFTERNOON.

LONG TERM...FRIDAY NIGHT THROUGH TUESDAY NIGHT

GUIDANCE HAS CONTINUED TO TREND COLDER WITH LOW TEMPERATURES
FRIDAY NIGHT...CAPTURED WELL BY A BLEND OF MODEL GUIDANCE AND
PREVIOUS FORECAST. ARCTIC HIGH WILL STRETCH ACROSS AREA...ALLOWING
FOR LIGHT WINDS AND STRONG RADIATIONAL COOLING OVERNIGHT. IF MINOR
SNOW COVER IS IN PLACE...FORECAST LOWS IN THE LOWER TO MIDDLE TEENS
FOR MUCH OF THE AREA OUTSIDE THE CHICAGO HEAT ISLAND MAY STILL END
UP BEING A FEW DEGREES TOO HIGH. SATURDAY WILL START OUT QUITE
COLD...BUT WARM ADVECTION ALOFT AND SOUTHWESTERLY FLOW AT THE
SURFACE WILL ALLOW FOR SOME RECOVERY TO THE UPPER 20S TO AROUND 30
DEGREES. FOR THE REMAINDER OF THE EXTENDED...THE AREA WILL REMAIN
INFLUENCED BY RIDGING OVER THE EASTERN CONUS...SO SOUTHWESTERLY
FLOW...DRY CONDITIONS...AND TEMPERATURES RETURNING TO SLIGHTLY ABOVE
NORMAL...OR AROUND 40 DEGREES...CAN BE EXPECTED. THERE MAY BE A COLD
FRONTAL PASSAGE DAY 6 OR DAY 7...BUT EVEN THAT MAY BE A DRY FROPA.

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 08Z...

* CIG TRENDS THROUGH INTO THE MORNING HOURS

SHEA

//DISCUSSION...UPDATED 08Z...

NORTHERN EDGE OF STRATUS APPEARS TO BE ACCELERATING SOUTH...AND
NUDGED UP THE TIMING OF WHEN THE MVFR CIGS SHOULD POP TO VFR.
TIMING MAY STILL NEED TO BE TWEAKED FASTER IF EROSION CONTINUES AS
FAST IT IS CURRENTLY TRENDING. OTHERWISE THE NEXT CONCERN WILL BE WITH HOW
FAR INTO THE TRACON THE HIGH IFR / LOW MVFR CIGS WILL ADVANCE BEFORE
CONDITIONS RAPIDLY IMPROVE. KFEP FELL TO 015 FOR A SHORT TIME
BEFORE MOVING BACK INTO MID RANGE MVFR... AND HAVE A FEELING THAT
WILL BE THE TREND WHEN CIGS FALL. DURATION NOT LOOKING TO BE TOO
LONG AND MODIFIED THE TAFOR TO INCLUDE THE LOWER CLOUDS IN A TEMPO
VS PREVAILING.

SHEA

//DISCUSSION...UPDATED 06Z...

A RIDGE OF HIGH PRESSURE IS SINKING SOUTHEAST ACROSS THE FORECAST
AREA...WITH LIGHT AND VARIABLE WINDS ACROSS MUCH OF NORTHERN
ILLINOIS. WHILE WE DID CLEAR OUT BRIEFLY EARLIER THIS
EVENING...STRATUS HAS ADVANCED EASTWARD ALONG THE RIDGE AXIS AND
EXTENDS AS FAR WEST AS EASTERN IOWA LATE THIS EVENING. SURFACE OBS
SHOW MVFR DECK ADVANCING EAST ACROSS THE RIVER...WITH IFR CIGS
BECOMING MORE WIDESPREAD. DONT SEE ANY REASON WHY CLOUDS WOULD
SCATTER/CLEAR BEFORE DAYBREAK TOMORROW AS ANY SUBSIDENCE ACROSS THE
AREA WOULD ONLY ENHANCE THE INVERSION TO HOLD IN THE MOISTURE...THUS
BUMPED BACK TIMING OF CLEARING TIL MID MORNING AND LOWERED CIGS TO
015 LATE TONIGHT. CANT RULE OUT IFR CONDITIONS REACHING THE CHICAGO
TERMINALS...BUT WITH GUIDANCE STILL NOT LOCKING ONTO THE LOW CIGS
DONT HAVE MUCH FEEL FOR HOW LOW CIGS WILL DROP OR WHEN...THOUGH RUC
SOUNDINGS DO SHOW CIGS CLOSE TO IFR AROUND 12Z. HAVE SOMEWHAT BETTER
CONFIDENCE AT RFD WITH MET/RUC GUIDANCE HONING IN ON 09Z.

ONCE RIDGE AXIS PASSES THROUGH...WINDS WILL BEGIN TO INCREASE OUT OF
THE WEST...WSW. GUSTS WILL PICK UP DURING THE AFTERNOON HOURS
WEDNESDAY AHEAD OF AN APPROACHING COLD FRONT WITH MODEST MIXING
BRINGING DOWN LOW 20KT WINDS. PRECIP WILL STAY NORTH OF THE
CHICAGO/ROCKFORD TERMINALS. DO EXPECT CLOUD COVER TO ONCE AGAIN
INCREASE...BUT SHOULD STAY VFR.

BMD

//ORD AND MDW CONFIDENCE...UPDATED 08Z...

* HIGH CONFIDENCE IN WIND FORECAST
* MODERATE TO HIGH CONFIDENCE IN VFR CIGS DROPPING TO MID-HIGH
MVFR...LOW CONFIDENCE IN FALLING BELOW 1.5 KFT

SHEA

//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...

THURSDAY...SLIGHT CHANCE OF SNOW OVERNIGHT. IFR/MVFR POSSIBLE.
FRIDAY...VFR.
SATURDAY...MVFR POSSIBLE.
SUNDAY...VFR.
MONDAY...VFR.

BMD

.MARINE...
230 AM CST

HIGH PRESSURE EXTENDING FROM NEWFOUNDLAND...THROUGH THE EASTERN
GREAT LAKES...TO TEXAS WILL CONTINUE TO BUILD SLOWLY EASTWARD OVER
THE NEXT FEW DAYS. MEANWHILE...LOW PRESSURE OVER NORTHERN HUDSON
BAY WILL DRAG A COLD FRONT ACROSS LAKE MICHIGAN LATE THIS
AFTERNOON AND EARLY THIS EVENING. A SURGE OF MUCH COOLER
AIR...COMBINED WITH HIGH PRESSURE BUILDING OUT OF THE NORTHERN
ROCKIES AND INTO THE NORTHERN PLAINS WILL LEAD TO QUICKLY
INCREASING...GENERALLY WESTERLY...WINDS OVER LAKE MICHIGAN. BRISK
WESTERLY WINDS WILL PERSIST OVER THE LAKE INTO SATURDAY. BY
SATURDAY NIGHT...THE HIGH WILL DROP INTO THE OHIO VALLEY AS LOW
PRESSURE DROPS OUT OF THE CANADIAN NORTHWEST TERRITORIES AND
TRACKS ACROSS THE PRAIRIE REACHES JAMES BAY BY SUNDAY MORNING.

KREIN

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744...6 PM
WEDNESDAY TO 10 PM THURSDAY.

SMALL CRAFT ADVISORY...LMZ745...6 PM WEDNESDAY TO 10 AM SATURDAY.

AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

207 AM CST WED DEC 7 2011

.DISCUSSION...
900 PM CST

MTF

PREVIOUS DISCUSSION...
417 PM CDT

SHORT TERM...THIS AFTERNOON THROUGH FRIDAY

MAIN CONCERN THIS PORTION OF THE FORECAST CENTERS ON LIGHT SNOW
CHANCES THURSDAY NIGHT INTO EARLY FRIDAY AND THEN BLAST OF ARCTIC
AIR FRIDAY INTO EARLY SATURDAY.

LONG TERM...FRIDAY NIGHT THROUGH TUESDAY NIGHT

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 08Z...

* CIG TRENDS THROUGH INTO THE MORNING HOURS

SHEA

//DISCUSSION...UPDATED 08Z...

SHEA

//DISCUSSION...UPDATED 06Z...

BMD

//ORD AND MDW CONFIDENCE...UPDATED 08Z...

* HIGH CONFIDENCE IN WIND FORECAST
* MODERATE TO HIGH CONFIDENCE IN VFR CIGS DROPPING TO MID-HIGH
MVFR...LOW CONFIDENCE IN FALLING BELOW 1.5 KFT

SHEA

//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...

THURSDAY...SLIGHT CHANCE OF SNOW OVERNIGHT. IFR/MVFR POSSIBLE.
FRIDAY...VFR.
SATURDAY...MVFR POSSIBLE.
SUNDAY...VFR.
MONDAY...VFR.

BMD

.MARINE...
158 PM CST

A SURFACE RIDGE OF HIGH PRESSURE EXTENDING FROM THE PLAINS
NORTHEASTWARD ACROSS THE UPPER GREAT LAKES REGION WILL SLOWLY SAG
SOUTHWARD TONIGHT AS A STRONG AREA OF LOW PRESSURE MOVES INTO
THE HUDSON BAY. AS THIS SURFACE RIDGE MOVES ACROSS LAKE MICHIGAN
THERE WILL BE A PERIOD OF LIGHTER WINDS THIS EVENING. HOWEVER...THIS
WILL BE SHORT LIVED AS THE WINDS WILL BECOME WEST SOUTHWESTERLY AND
INCREASE TO NEAR 30 KT LATER TONIGHT ACROSS THE NORTHERN HALF OF THE
LAKE. THESE WINDS WILL CONTINUE LAKE-WIDE DURING THE DAY ON
WEDNESDAY AS A COLD FRONT MOVES SOUTH ACROSS THE LAKE. THERE COULD
BE A PERIOD OF LOW END GALES AS THE COLD AIR BEGINS TO PUSH ACROSS
THE LAKE WEDNESDAY NIGHT INTO THURSDAY. HOWEVER...WIDESPREAD 30 KT
WITH SOME GALE FORCE GUSTS APPEARS TO BE THE MOST LIKELY AT THIS
TIME.

WINDS ACROSS LAKE MICHIGAN LOOK TO REMAIN IN THE 15 TO 25 KT RANGE
INTO FRIDAY AS THE PRESSURE GRADIENT BETWEEN THE LOW ACROSS THE
HUDSON BAY AND HIGH PRESSURE ACROSS THE PLAINS REMAINS ELEVATED.
ANOTHER SURGE OF HIGHER WINDS...POTENTIALLY GALE FORCE...LOOKS TO
OCCUR ON SATURDAY AS ANOTHER AREA OF LOW PRESSURE TRACKS ACROSS
SOUTHERN CANADA.

KJB

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

1144 PM CST TUE DEC 6 2011

.DISCUSSION...
900 PM CST

MTF

PREVIOUS DISCUSSION...
417 PM CDT

SHORT TERM...THIS AFTERNOON THROUGH FRIDAY

MAIN CONCERN THIS PORTION OF THE FORECAST CENTERS ON LIGHT SNOW
CHANCES THURSDAY NIGHT INTO EARLY FRIDAY AND THEN BLAST OF ARCTIC
AIR FRIDAY INTO EARLY SATURDAY.

LONG TERM...FRIDAY NIGHT THROUGH TUESDAY NIGHT

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* VARIABLE CIGS THIS EVENING...MVFR RETURNING AND POTENTIAL FOR IFR.
* LIGHT WINDS THIS EVENING BECOMING WEST...WSW OVERNIGHT.

BMD

//DISCUSSION...UPDATED 06Z...

BMD

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* MEDIUM TO HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM TO HIGH CONFIDENCE IN MVFR CONDITIONS...LOW CONFIDENCE
IN IFR.

BMD

//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...

THURSDAY...SLIGHT CHANCE OF SNOW OVERNIGHT. IFR/MVFR POSSIBLE.
FRIDAY...VFR.
SATURDAY...MVFR POSSIBLE.
SUNDAY...VFR.
MONDAY...VFR.

BMD

.MARINE...
158 PM CST

KJB

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

1007 PM CST TUE DEC 6 2011

.DISCUSSION...
900 PM CST

AS ANTICIPATED...CLOUDS ARE MAKING IT EXTRA CHALLENGING WITH THE
TEMPERATURE FORECAST TONIGHT. THE CLEARING WAS SHORT-LIVED...WITH
CLOUDS BOTH EXPANDING AND ADVECTING BACK EAST WITHIN AND JUST ON
THE BACKSIDE OF THE LOW-LEVEL RIDGE. AN UPPER LEVEL TROUGH ALOFT
OVER THE AREA IS CONTINUING TO SHEAR OUT...WITH SUPPRESSION
APPARENTLY INCREASING LOOKING AT THE WATER VAPOR SATELLITE. THE
EVENING DVN AND ILX SOUNDINGS DEPICTED A FAIRLY DEEP 3000 FT LAYER
AT SATURATED OR NEAR-SATURATED...AND THERE ARE FEW SIGNS OF HOLES
EXISTING WITHIN THE CLOUD RIBBON. DESPITE THAT...THE BACK EDGE IS
PROGRESSING...LOCATED ABOUT 100 MILES WEST OF THE MISSISSIPPI
RIVER AROUND 9 PM. THE NAM AND RUC ANALYSES OF 925-850MB MOISTURE
CAPTURE THIS WELL AND THE PROGRESSION OF THIS. THEIR DRYING
FORECAST COMES ACROSS NORTHERN IL FROM 3 AM THROUGH
DAYBREAK...COINCIDENT WITH THEIR DEPICTION OF HIGHER Q-VECTOR
DIVERGENCE /A PROXY FOR THE SUPPRESSION MENTIONED EARLIER/. THE
LAMP GUIDANCE HAS A VERY GOOD HANDLE ON THE STEADY TEMPERATURES
UNDER THE CLOUD COVER AND SHOW A LATE NIGHT DROP...ESPECIALLY IN
THE WESTERN FORECAST AREA. HAVE STEERED THIS AND THE RUC TREND
INTO THE FORECAST. OVERALL...MINIMUMS ARE SLIGHTLY WARMER FOR MOST
PLACES...A FEW DEGREES TOTAL FOR SOUTH AND EAST OF CHICAGO WHICH
SHOULD SEE THE CLOUDS ARRIVE SHORTLY AND LAST ALL THE WAY THROUGH
DAYBREAK.

MTF

PREVIOUS DISCUSSION...
417 PM CDT

SHORT TERM...THIS AFTERNOON THROUGH FRIDAY

MAIN CONCERN THIS PORTION OF THE FORECAST CENTERS ON LIGHT SNOW
CHANCES THURSDAY NIGHT INTO EARLY FRIDAY AND THEN BLAST OF ARCTIC
AIR FRIDAY INTO EARLY SATURDAY.

LONG TERM...FRIDAY NIGHT THROUGH TUESDAY NIGHT

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 04Z...

* VARIABLE CIGS THIS EVENING...MVFR RETURNING LATE THIS
EVENING...AND POTENTIAL FOR IFR.
* LIGHT WINDS BECOMING WEST...WSW OVERNIGHT. BMD

//DISCUSSION...UPDATED 00Z...

MAIN FORECAST CONCERNS WILL BE DEALING WITH VARIABLE CIGS AND
BACKING WINDS AS RIDGE AXIS SLIDES ACROSS THE REGION. SKIES HAVE
CLEARED OUT OVER MOST OF NORTH CENTRAL AND NORTHEASTERN ILLINOIS
THIS EVENING...HOWEVER NARROW BAND OF STRATUS UNDER THE RIDGE
AXIS WITH MVFR AND OCCASIONAL IFR CIGS SPANNING ACROSS
NORTHWESTERN ILLINOIS AND EASTERN IOWA. THIS MOISTURE WILL MOVE
EAST AHEAD OF THE RIDGE...WITH POTENTIALLY MVFR CIGS RETURNING
OVERNIGHT. MOS GUIDANCE DOES NOT HANDLE THIS MOISTURE
WELL...HOWEVER NAM/RUC 925MB RH FIELDS DO INDICATE LOW LEVEL
MOISTURE RETURNING AFTER MIDNIGHT LOCAL TONIGHT TO THE CHICAGO
AREA TERMINALS. LOW LEVEL MOISTURE IS EXPECTED TO PUSH OUT OF THE
AREA MID TO LATE MORNING WITH ADDITIONAL HIGH AND MID CLOUDS
MOVING IN FROM THE NORTH ALONG THE TAIL END OF A COLD FRONT. NO
PRECIP IS EXPECTED...HOWEVER WINDS ARE EXPECTED TO TURN BACK TO
THE WNW BY LATE WEDNESDAY AFTERNOON/EARLY EVENING. BMD

//ORD AND MDW CONFIDENCE...UPDATED 04Z...

* MEDIUM TO HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM CONFIDENCE IN DETAILS OF CIG FORECAST. BMD

//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...

THURSDAY...SLIGHT CHANCE OF SNOW OVERNIGHT. IFR/MVFR POSSIBLE.
FRIDAY...VFR.
SATURDAY...MVFR POSSIBLE.
SUNDAY...VFR.
MONDAY...VFR.

BMD

.MARINE...
158 PM CST

KJB

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

AREA FORECAST DISCUSSION...UPDATED

NWS INDIANAPOLIS IN

1008 PM EST THU DEC 8 2011

.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

.SYNOPSIS...WEAK HIGH PRESSURE SOUTHEAST OF CENTRAL INDIANA WILL
QUICKLY DEPART THE AREA TONIGHT AS A QUICK MOVING UPPER LEVEL
DISTURBANCE PUSHES INTO THE SOUTHERN GREAT LAKES AND OHIO VALLEY
LATE TONIGHT. DUE TO LIMITED MOISTURE AVAILABLE...ANY SNOWFALL
AMOUNTS WILL BE QUITE LIGHT.

THE UPPER DISTURBANCE WILL EXIT BY FRIDAY AFTERNOON...ALLOWING
COLDER AIR ASSOCIATED WITH HIGH PRESSURE TO ARRIVE FOR THE
WEEKEND. IF FACT...HIGH TEMPERATURES ON SATURDAY MAY NOT RISE
ABOVE FREEZING AT IND. THIS WOULD BE THE FIRST TIME THAT HAS
HAPPENED SINCE FEBRUARY 10TH 2011.

DRY WEATHER SHOULD THEN PERSIST UNTIL TUESDAY WHEN ANOTHER
MOISTURE STARVED QUICK MOVING COLD FRONT WILL PUSH ACROSS THE
AREA. ANOTHER STRONGER SYSTEM MAY ARRIVE ON THURSDAY AS LOW
PRESSURE DEVELOPS OVER THE PLAINS STATES.

.NEAR TERM /REST OF TONIGHT/...
MODELS SHOW UPPER FORCING FOR THE SYSTEM MOVING INTO THE AREA
TONIGHT ALL STAYING NORTH...AND CROSS SECTIONS DON/T SHOW ANY
INSTABILITY TO CONTRIBUTE TO BANDING. 0Z NAM SHOWS ISENTROPIC
LIFT AT 6Z BUT SATURATION DOESN/T MAKE IT DOWN TO THE LOWER LEVELS
UNTIL 9Z WHEN MOST OF THE ISENTROPIC LIFT IS GONE. THAT SAID THE
NAM IS STILL PRODUCING QPF GENERALLY NORTH OF I70.

0 AND 1Z RUC ARE KEEPING ALL PRECIPITATION WEST AND THEN NORTH OF THE
FORECAST AREA...AND THE LATEST RUN IS SHOWING LESS ISENTROPIC LIFT
AVAILABLE THAN EARLIER RUNS. ALL OF THE CURRENT SNOW THAT IS FALLING
IN NEBRASKA...IOWA AND WESTERN ILLINOIS APPEARS TO BE ASSOCIATED
WITH UPPER FORCING AND IS BEHIND THE FRONT. HOWEVER THE RAPID
REFRESH SHOWS THE SNOW IN THE WESTERN ILLINOIS BAND EXPANDING AND
PRODUCING MEASURABLE SNOW ACROSS THE NORTHERN COUNTIES BY AROUND 6
OR 7Z...WHICH LOOKS MUCH MORE LIKE THE 0Z NAM.

ULTIMATELY AM FEELING FAIRLY CONFIDENT IN THE FORECAST OF LITTLE TO
NO ACCUMULATION FROM THE I70 CORRIDOR SOUTH. GREATEST UNCERTAINTY
EXISTS NORTH OF A DANVILLE ILLINOIS TO MUNCIE LINE WHERE MODEL
DISAGREEMENT IS HIGH AND ANALYSIS OF CURRENT CONDITIONS IS
UNFORTUNATELY NOT PROVIDING A LIGHTBULB MOMENT. CEILINGS HAVE BEEN
DROPPING AT KLAF...SO THERE IS SOME INDICATION THEY COULD SATURATE
ENOUGH EVENTUALLY THAT ISENTROPIC LIFT COULD PRODUCE A LITTLE
ACCUMULATION. WITH MORE MODELS POINTING TO SOME AMOUNT OF SNOW IN
THE NORTH THAN NOT...THINK BEST COURSE OF ACTION AT THIS TIME IS TO
RAISE POPS THERE INTO THE HIGHER CHANCE CATEGORY. WITH THE RUC
SHOWING DRY OVER THE AREA THOUGH AND LESS IMPRESSIVE FORCING WILL
NOT GO UP TO LIKELIES THERE. WILL ALSO NOT MAKE ANY ADJUSTMENTS TO
AMOUNTS...WITH ONLY HALF AN INCH TOTALS IN THE NORTH. TEMPERATURES
AND OTHER FIELDS STILL LOOK ON TRACK...SO NO OTHER CHANGES MADE.

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

MAIN FOCUS DURING THIS PERIOD WILL BE ENDING ANY SNOWFALL ON
FRIDAY AND THEN FOCUS WILL BE TEMPERATURES.

TIME HEIGHTS ON FRIDAY MORNING CONTINUE TO SHOW A SIMILAR PATTERN
TO WHAT WAS PREVIOUSLY DISCUSSED IN THE PRIOR PERIOD...WITH
LIMITED FORCING AND LIMITED SATURATION. THUS SOME LINGERING LIGHT
SNOW SHOWERS WILL BE POSSIBLE MAINLY ACROSS THE NORTHERN PARTS OF
THE FORECAST AREA...AND GRADUALLY TAPER OFF AS THE DAY PROGRESSES
AS THE FORCING ASSOCIATED WITH THE SHORT WAVE DEPARTS. BY 00Z
FORECAST SOUNDINGS BECOME QUITE DRY AS STRONG COLD AIR ADVECTION
THAT STARTS IN THE MORNING CONTINUES THROUGH THE DAY. 850MB TEMPS
ARE EXPECTED TO FALL TO A CHILLY -9 BY 00Z AND TO -11C BY 12Z.
THUS WILL TREND HIGHS ON FRIDAY NEAR MAVMOS 3 HOURLIES INSTEAD.

FORECAST SOUNDINGS THEN DRY OUT SIGNIFICANTLY ON FRIDAY NIGHT
THROUGH SUNDAY NIGHT AS A LARGE AREA OF COLD HIGH PRESSURE SETTLES
OVER THE OHIO VALLEY. AS STATED ABOVE...HIGH TEMPERATURES ON
SATURDAY ARE NOT EXPECTED TO EXCEED FREEZING AND WILL AGAIN TRENDS
THESE TOWARD THE 3HOURLY MAVMOS TEMPS. AS FOR FRIDAY NIGHT
LOWS...CLEAR SKIES ARE EXPECTED WITH LIGHT NORTHWEST WINDS. THUS WILL
TREND FRIDAY NIGHT LOWS COOLER THAN MAVMOS.

MUCH STRONGER WARM AIR ADVECTION WILL BE IN PLACE ON SATURDAY
NIGHT AND ON SUNDAY AS THE DOME OF COLD AIR DEPARTS TO THE EAST
AND SOUTHERLY SURFACE FLOW BEGINS ON RETURN FLOW AROUND THE
SURFACE HIGH TO THE EAST. PLENTY OF SUN STILL EXPECTED FOR
SATURDAY...HOWEVER A FEW MORE CLOUDS ON SUNDAY AMID THE WARM AIR
ADVECTION. STILL PARTLY CLOUDY WILL BE THE RULE. WILL TREND
SATURDAY NIGHT LOWS WARMER THAN MAVMOS AS WELL AS SUNDAY/S HIGHS
GIVEN THE WARM AIR ADVECTION.

.LONG TERM /MONDAY THROUGH THURSDAY/...

QUITE A BIT OF DIFFERENCES AMONG THE ENSEMBLE DATA REGARDING HOW
FAST THE CUTOFF LOW THAT IS EXPECTED TO BE OVER THE SOUTHWEST
PARTS OF THE COUNTRY ON MONDAY WILL EJECT TOWARDS THE OHIO VALLEY.
THERE DOES SEEM TO BE SOME AGREEMENT THAT OVERALL...LONG WAVE
TROUGHING WILL BE LOCATED AROUND THE MIDDLE OF COUNTRY BY NEXT
THURSDAY. AS A RESULT...WILL GO WITH A GRADUALLY INCREASING
THREAT OF PRECIPITATION STARTING ON TUESDAY...WITH THE HIGHEST
POPS EXPECTED BY NEXT THURSDAY CLOSEST TO THE APPROACH OF THE LONG
WAVE TROUGH.

.AVIATION /DISCUSSION FOR THE 090300Z TAF UPDATES/...

TAF FORECASTS LOOK ON TRACK...MADE NO CHANGES EXCEPT FOR MINOR
TWEAKS. PREVIOUS DISCUSSION FOLLOWS...

EXPECT IFR CONDITIONS AFTER 06Z TONIGHT AT LAF AS AN UPPER TROUGH
APPROACHES FROM THE WEST. IND AND HUF COULD ALSO FLURRIES OR
LIGHT SNOW AFTER 06Z THROUGH FRIDAY MORNING...BUT THOSE TERMINALS
SHOULD BE NEAR THE EDGE OF THE SNOWFALL. SO FOR NOW...WILL ONLY GO
MVFR THERE AND AMEND LATER IF NEEDED. MEANWHILE...BMG SHOULD BE VFR
WITH ONLY FLURRIES AT THE WORST. MEANWHILE...COLD FRONT JUST NORTH
OF LAF EXPECTED TO MOVE TO NEAR HUF AND IND AROUND 06Z TONIGHT AND
08Z AT BMG. WINDS WILL BE LIGHT FROM THE SOUTHWEST AHEAD OF THE
FRONT AND SHIFT TO THE NORTHWEST BEHIND IT INCREASING TO AROUND 10
KNOTS AFTER 18Z TOMORROW.

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SYNOPSIS...PUMA
NEAR TERM...CP
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...MK

AREA FORECAST DISCUSSION

NWS DODGE CITY KS

555 PM CST THU DEC 8 2011

.UPDATE...

.AVIATION /FOR THE 00Z TAF ISSUANCE/

A WEAK SURFACE HIGH PRESSURE RIDGE IS FOCUSED FROM THE NORTHERN INTO
CENTRAL PLAINS STATES THIS EVENING, WITH A RELATIVE LOW PRESSURE
AREA ACROSS THE TEXAS PANHANDLE. THIS WILL MAINTAIN LIGHT NORTH
WINDS ACROSS WESTERN KANSAS OVERNIGHT DUE TO THE PERSISTENT PRESSURE
GRADIENT. CIRRUS CLOUDS ARE OVERSPREADING THE AREA, WHILE A
THICKER LOW STRATUS REGION SIDES FROM NEBRASKA INTO NORTHERN KANSAS
EARLY THIS EVENING. THE HRRR AND NAM WERE IN LINE WITH ONE ANOTHER
WITH LOW VISIBILITIES DUE TO FOG DEVELOPMENT LATE THE EVENING AND
OVERNIGHT, AND THE GFS LAMP MOS INDICATES FOG DEVELOPMENT BY MORNING
IN THIS WEAKLY UPSLOPE ENVIRONMENT.

.PREV DISCUSSION... /ISSUED 352 PM CST THU DEC 8 2011/

DISCUSSION...

DAYS 1-2...

A SHORTWAVE TROUGH MOVING ACROSS THE NORTHERN PLAINS TODAY WILL
PROGRESS INTO THE UPPER MIDWEST BY FRIDAY. ALL OF THE DEEP MOISTURE
WITH THIS SYSTEM IS WELL TO OUR NORTHEAST. AHEAD AND WELL SOUTH OF
THIS SYSTEM THERE IS A WEAK SURFACE LOW THAT IS PARTLY FORCED BY
DOWNSLOPE FLOW OVER THE EASTERN TEXAS PANHANDLE. A WEAK COLD FRONT
WAS SITUATED ACROSS SOUTHERN NEBRASKA. NO PRECIPITATION IS EXPECTED
ACROSS WESTERN KANSAS TONIGHT AS THIS SYSTEM CONTINUES TO MOVE AWAY
FROM OUR FORECAST AREA AND SINCE ISENTROPIC LIFT IS FORECAST TO BE
MINIMAL. HOWEVER, AS THE FRONT PASSES THROUGH WESTERN KANSAS, THE
BOUNDARY LAYER IS PROGGED TO MOISTEN UP AND COOL OFF SIMULTANEOUSLY.
THIS COULD LEAD TO WIDESPREAD LOW STRATUS CLOUDS AND POSSIBLY AREAS
OF FREEZING FOG. BUFR SOUNDINGS SUGGEST FREEZING FOG DEVELOPMENT
AS THE TEMPERATURE DROPS WITH THE DEWPOINT.

SURFACE HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS WESTERN KANSAS
FRIDAY AND FRIDAY NIGHT IN THE WAKE OF THE AFOREMENTIONED SHORTWAVE
TROUGH. SOLAR HEATING WILL GRADUALLY ERODE LOW CLOUDS AND FOG BY
MID-MORNING. HIGH TEMPERATURES FRIDAY WILL BE ABOUT THE SAME AS
TODAY, WITH THE COOLEST READINGS OVER THE SNOW COVERED AREAS ALONG
AND NORTHWEST OF A LINE FROM SYRACUSE TO ELLIS. THE NAM IS A LITTLE
COOLER FOR DODGE CITY, BUT THIS MAY BE A RESULT OF ITS SNOW COVER
FIELD BEING TOO FAR SOUTH. GOOD RADIATIONAL COOLING CAN BE EXPECTED
FRIDAY NIGHT, ESPECIALLY OVER CENTRAL AND SOUTH CENTRAL KANSAS WHERE
HIGH PRESSURE WILL STILL LINGER ALONG WITH LIGHT WINDS AND MOSTLY
CLEAR SKIES.

THE MID TO UPPER-LEVEL FLOW WILL BECOME MORE ZONAL BY SATURDAY. THIS
OFTEN RESULTS IN LEE TROUGHING, WEAK DOWNSLOPE FLOW AND A
WARMING TREND. HOWEVER, THIS WILL BE A SLOW PROCESS AS SEA LEVEL
PRESSURE VALUES ARE STILL PROGGED TO BE AROUND 1030-1032MB EVEN BY
SATURDAY AFTERNOON. THE PREVIOUSLY FORECASTED HIGH TEMPERATURES
BETWEEN 40 AND 45F FOR SATURDAY STILL LOOK ON TRACK.

DAYS 3-7...

THE EXTENDED PERIOD BEGINS 00Z SUNDAY. SOUTHWEST KANSAS WILL BE IN
SPLIT FLOW AT THE END OF THE WEEKEND (IN BETWEEN AN ACTIVE NORTHERN
AND SOUTHERN BRANCH JETS). WITH THE WESTERLY FLOW ALOFT, WE WILL SEE
LEE SURFACE TROUGHING ACROSS COLORADO. THIS WILL ALLOW FOR SOUTHERLY
WINDS AT THE SURFACE WITH NEAR SEASONAL TEMPERATURES (MAINLY 40S DEG
F) FOR HIGHS.

ON MONDAY, A WEAK NORTHERN SHORTWAVE TROUGH WILL USHER IN THE
PASSAGE OF A COLD FRONT. THIS FRONT IS NOT VERY STRONG AND THE COLD
AIR ADVECTION BEHIND THE FRONT IS FAIRLY WEAK. AS A RESULT, THE
FORECAST WILL BE DRY AND TEMPERATURES WILL BE SLIGHTLY COOLER EXCEPT
ACROSS THE SOUTHEAST ZONES DUE TO A LATER IN THE DAY FRONTAL PASSAGE.

FOR TUESDAY, MID AND UPPER LEVEL FLOW STRENGTHENS AND WE SHOULD SEE
A RETURN TO LEE SURFACE TROUGHING. TEMPERATURES WILL MODERATE
SLIGHTLY WITH SOUTHERLY WINDS. FORECAST SOUNDINGS SHOW THE
ATMOSPHERE MOISTENING FROM TOP DOWN TUESDAY EVENING SO WE SHOULD SEE
MORE CIRRUS.

THE FORECAST BECOMES MORE INTERESTING WEDNESDAY AS A RELATIVELY
STRONG STORM SYSTEM MOVES ACROSS THE CENTRAL PLAINS. THIS LOOKS LIKE
A RAIN EVENT FOR MUCH SW KANSAS. THE MODELS ARE INDICATING SLIGHTLY
COOLER AIR AT 850 HPA THAN COMPARED TO YESTERDAY SO WOULD NOT RULE
OUT SOME WINTRY PRECIPITATION. RIGHT NOW THE FORECAST IS OF LOW
CONFIDENCE. THIS IS ALSO TOWARDS THE END OF THE EXTENDED PERIOD SO
WILL KEEP PRECIPITATION TYPE AS RAIN IN CASE THE MODELS WAFFLE BACK
TO A WARMER SOLUTION. TEMPERATURES COULD FLIRT WITH THE 50 DEG F
MARK WEDNESDAY AS SOUTHERLY WINDS CONTINUE AND HIGHER DEWPOINTS ARE
ADVECTED IN FROM AN OPEN GULF OF MEXICO. THERE ARE STILL SIGNIFICANT
DIFFERENCES BETWEEN THE GFS AND ECMWF SO THE FORECAST WILL LIKELY
CHANGE WITH TIME. REGARDLESS, THE SIGNAL IS THERE FOR SOME
PRECIPITATION MIDWEEK ACROSS KDDC COUNTRY. -SUGDEN

.PRELIMINARY POINT TEMPS/POPS...
DDC 19 41 17 44 / 0 0 0 0
GCK 17 36 16 42 / 0 0 0 0
EHA 19 35 17 44 / 0 0 0 0
LBL 20 42 20 44 / 0 0 0 0
HYS 17 35 14 41 / 10 0 0 0
P28 22 41 16 46 / 10 0 0 0

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

FN99/99

AREA FORECAST DISCUSSION

NWS LOUISVILLE KY

602 PM EST WED DEC 07 2011

...Updated Aviation Discussion...

.Short Term (Tonight and Thursday)...

First off, snow band was not as impressive as the HRRR earlier today
made it out to be. County officials in our Lake Cumberland region
have all indicated very little snow stuck. Webcams from that area
also look mostly just wet and not white. Had some pictures with snow
from the LEX-area webcams in a brief band that went through their in
the last couple of hours, but likewise nothing has accumulated.
Surface temperatures are just too warm, in the mid 30s along with
the still wet grounds from the rain earlier in the week.

Sunshine is poking out some in cloud cover west of a KLEX to
Scottsville line. With any heating though, additional low clouds are
developing. These clouds may yet produce some scattered very light
flurries across central KY, but temperatures will not be cool enough
where these clouds are to promote lots of snow. With the cloud
cover, temperatures are holding to around 40 degrees at most.

Skies should clear out overnight as deep dry air moves into the
region. High pressure will move in south of the region, so expect a
general westerly wind through the night. Expect temperatures to fall
into the 20s areawide overnight under these clear skies. Sheltered
locations may see the low 20s.

High pressure will be centered over the Appalachians during the day
Thursday. Thus expect a southwesterly flow. Clear skies should allow
us to reach the low/mid 40s areawide, roughly 5 degrees below normal.

.Long term (Thursday night - Wednesday)...

A digging shortwave will dive from the northern plains into the
lower Great Lakes on Friday. Moisture return ahead of this system
will be limited and therefore continued to only mention flurries in
the forecast early Friday morning across southern Indiana, gradually
working eastward across north central Kentucky and the Bluegrass
through the day. Temperatures ahead of the front will likely warm
enough for just sprinkles in the late morning and afternoon. In the
morning and the evening, moisture to about 700 mb should yield
some potential for ice crystals as temps at this level will be
around -10 C. No impacts from these flurries are anticipated.

Otherwise, cold frontal boundary moves through Friday afternoon and
evening with a cold airmass lurking for the weekend. Lows Friday
night are expected to drop into the lower 20 in most spots, with a
few upper teens possible across southern Indiana and perhaps the
Bluegrass. High temperatures on Saturday will struggle, only making
it to the low and mid 30s. Saturday night will bring more
temperatures right around the 20 degree mark.

Sunday into the middle of next week, mid level flow will gradually
transition from a progressive zonal flow then try to head back toward
the classic La Nina pattern we have been seeing which would yield
southwest flow aloft with a ridge to our southeast and a developing
trough over the western CONUS. Will keep forecast through Wednesday
dry, although some signs point to another potent system tracking
into the region possibly Thursday or Friday. Although this is pretty
far out, confidence in the recent pattern supported by
teleconnections could lead to another substantial precipitation
event across the Ohio Valley. Stay tuned.

Highs through the first half of next week will gradually moderate
toward the mid 40s, with upper 40s and low 50s ahead of the next
system possible on Wednesday. Lows each night will be in the 20s,
warming to the low 30s by Wednesday morning.

.Aviation (00Z TAF Issuance)...

Expect VFR conditions through the TAF period as our latest weather
system departs the region to the east. Skies will continue to clear
from west to east overnight. Additionally, dry air is filtering into
the area. The T/Td spread should be large enough to limit fog
formation overnight. Current guidance and trends in the observations
are illustrating this as well. Surface winds will become
southwesterly by morning as surface high pressure builds across the
Appalachians.

.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$

Short Term.......RJS
Long Term........BJS
Aviation.........MJP

AREA FORECAST DISCUSSION

NWS LOUISVILLE KY

229 PM EST WED DEC 07 2011

.Short Term (Tonight and Thursday)...

.Long term (Thursday night - Wednesday)...

.Aviation (18Z TAF Issuance)...

Looks like the best band of precip is setting up just east of all of
the TAF sites early this afternoon. 18Z package will go out with
some light showers in the vicinity of KLEX for a few more hours.
Expect MVFR-level clouds to stick around KBWG to mid afternoon and
over KLEX into the evening hours. After that skies will clear
quickly, and expect VFR conditions rest of period. Winds will start
off just west of northerly and then become more westerly by this
evening, as low pressure currently over the Appalachians shifts
eastward farther away from the area.

.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$

Short Term.......RJS
Long Term........BJS
Aviation.........RJS

AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

308 PM EST WED DEC 7 2011

.SYNOPSIS...
STRENGTHENING LOW PRESSURE, MOVING NORTHEASTWARD PAST THE VIRGINIA COAST,
HAS DRAWN COLDER AIR INTO THE UPPER OHIO VALLEY TO CAUSE A CHANGE
TO SNOW. SOME MOUNTAIN LOCATIONS CAN GET HEAVY SNOW AMOUNTS. HIGH
PRESSURE WILL FOLLOW WITH DRY, BRISK CONDITIONS THURSDAY. AN
EASTBOUND COLD FRONT THROUGH THE GREAT LAKES WILL PROVIDE
SCATTERED SNOW SHOWERS FRIDAY NIGHT.

.NEAR TERM /THROUGH THURSDAY/...
HAVE CONTINUE TO MAKE ADJUSTMENTS TO PRECIPITATION TYPE AND
DURATION AND TEMPERATURES BASED ON RECENT TRENDS IN SURFACE AND
RADAR DATA ALONG WITH RECENT HRRR AND NAM MODEL OUTPUT.

EXPECT ALL THE PRECIPITATION TO BE SNOW BY 3 TO 4 PM. BASED ON NAM
MODEL PROFILES, SHOWING STRONG UPDRAFTS WITHIN THE DENDRITIC SNOW
GROWTH ZONE AROUND -15C, STILL EXPECT A BURST OF HEAVIER SNOW
ACROSS THE MOUNTAINS THIS EVENING. HENCE HAVE MAINTAINED THE
WINTER STORM WARNINGS AND ADVISORIES FOR THE MOUNTAIN AREAS WITH
SNOW AMOUNTS UPWARDS OF 4 INCHES.

STILL THINK THE SNOWFALL WILL CUTOFF GENERALLY BY 2 AM FOR THE
RIDGES. HAVE WIND GUSTS TO 30 MPH PER NAM MODEL PROFILES.

DUE TO DROPPING TEMPERATURES TONIGHT, FOR ALL LOCATIONS, REGARDLESS
OF SNOW AMOUNTS, THERE IS THE HAZARD OF WET UNTREATED PAVEMENTS
TURNING ICY. LOWS TONIGHT IN THE LOWER TO MID 20S.

ENSUING HIGH PRESSURE SHOULD PROVIDE ALL LOCATIONS WITH DRY, BRISK
CONDITIONS THURSDAY.

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
MAINLY DRY AND COLD CONDITIONS WILL PREVAIL THURSDAY NIGHT.

THE NEXT FRONT IS PROGGED TO AFFECT THE REGION FRIDAY AND
FRIDAY NIGHT. MOST MODELS IN AGREEMENT KEEPING THE GREATEST
FORCING AND MOISTURE FROM THE I-80 CORRIDOR NORTHWARD. WILL
INCREASE POPS TO LIKELY THERE LATE FRIDAY INTO FRIDAY NIGHT
WITH CHANCE POPS FOR WESTERN PA...WITH LESSER CHANCES ACROSS
EASTERN OHIO. THERMAL PROFILES WILL BE COLD ENOUGH FOR A MAINLY
SNOW EVENT.

SUB ADVISORY LEVEL SNOW ACCUMULATIONS ARE POSSIBLE FOR THE I-80
CORRIDOR...WITH MINOR ACCUMULATIONS FOR THE RIDGES AND LITTLE
ACCUMULATION ELSEWHERE. THE SYSTEM WILL EXIT THE REGION BY
SATURDAY FOR DRY AND COLD CONDITIONS.

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL DOMINATE THE FIRST HALF OF THE PERIOD WITH
TEMPERATURES BELOW NORMAL...MODERATING A FEW DEGREES EACH DAY AS THE
FLOW BECOMES MORE SOUTHERLY.

MORE UNCERTAINTY LIES IN THE LATER PART OF THE PERIOD AS THE
DETERMINISTIC MODELS HANDLE THE DEVELOPMENT OF THE NEXT SYSTEM
DIFFERENTLY FOR WEDNESDAY AND THURSDAY.

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
EXPECT AREAS OF IFR IN SNOW AND FOG INTO 03Z. CONDITIONS SHOULD
IMPROVE...FIRST AT ZZV AND FKL WHERE CIGS HAVE ALREADY LIFTED TO
MVFR...AND LAST AT MGW AND LBE SINCE THE WRAP-AROUND MOISTURE
ASSOCIATED WITH THE LOW WILL BE LAST TO LEAVE THESE PORTS.

SKIES SHOULD SCATTER OUT OVERNIGHT BUT WITH NORTHWEST FLOW ALOFT
SCATTERED TO BROKEN CU SHOULD REDEVELOP ON THURSDAY. THINK AT THIS
POINT THAT CONDITIONS WILL REMAIN VFR DURING THE DAY THURSDAY BUT
WITH ENHANCEMENT FRONT THE LAKE...MVFR CIGS MAY CAUSE TEMPORARY
IMPACTS ESPECIALLY FOR THE NORTHERN PORTS.

OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
GENERALLY VFR THROUGH MONDAY WITH POSSIBLE RESTRICTIONS IN SNOW WITH
THE SHORTWAVE PASSAGE FRIDAY NIGHT/SATURDAY.

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WARNING UNTIL 4 AM EST THURSDAY FOR MDZ001.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 4 AM EST THURSDAY FOR PAZ023-031-
073-075.
WINTER STORM WARNING UNTIL 4 AM EST THURSDAY FOR PAZ074-076.
WV...WINTER WEATHER ADVISORY UNTIL 4 AM EST THURSDAY FOR WVZ021-022.
WINTER STORM WARNING UNTIL 4 AM EST THURSDAY FOR WVZ023-041.

AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

1142 AM EST WED DEC 7 2011

.SYNOPSIS...
STRENGTHENING LOW PRESSURE, MOVING NORTHEASTWARD THROUGH VIRGINIA,
WILL DRAW COLDER AIR INTO THE UPPER OHIO VALLEY AND CHANGE ANY
REMAINING RAIN TO WET SNOW BY TONIGHT. SOME MOUNTAIN LOCATIONS CAN
GET HEAVY SNOW AMOUNTS. HIGH PRESSURE WILL PROVIDE DRY, BRISK
CONDITIONS THURSDAY.

.NEAR TERM /THROUGH THURSDAY/...
MADE ADJUSTMENTS TO DURATION OF PRECIPITATION AND TIMING OF CHANGE
FROM RAIN TO SNOW BASED ON BLEND OF RECENT SURFACE AND RADAR DATA
AND HRRR AND NAM MODEL OUTPUT. HAVE GOTTEN SOME REPORTS OF WET
SNOW STARTING OVER THE HIGHER MOUNTAINS. HAVE CONCERNS HOW LONG
THE PRECIPITATION WILL HANG ON TO AREAS WEST OF THE RIDGES THIS
EVENING. DYNAMICS STILL VERY FAVORABLE FOR A BURST OF HEAVY WET
SNOW ACROSS THE MOUNTAINS THIS EVENING.

SO FOR NOW HAVE LARGELY MAINTAINED THE FORECASTED SNOW AMOUNTS.
DID CUT OFF END OF THE SNOWFALL GENERALLY BY 2 AM FOR THE RIDGES.
HAVE WIND GUSTS TO 30 MPH PER NAM MODEL PROFILES.

DUE TO DROPPING TEMPERATURES TONIGHT, FOR ALL LOCATIONS, REGARDLESS
OF SNOW AMOUNTS, THERE IS THE HAZARD OF WET UNTREATED PAVEMENTS
TURNING ICY. LOWS TONIGHT IN THE LOWER TO MID 20S.

ENSUING HIGH PRESSURE SHOULD PROVIDE ALL LOCATIONS WITH DRY, BRISK
CONDITIONS THURSDAY.

.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
COLD WEST WINDS ACROSS THE LAKE ERIE MAY CAUSE A FEW SNOW SHOWERS
ACROSS THE I-80 CORRIDOR THURSDAY OTHERWISE DRY AND COLD.

HIGH PRESSURE SHOULD PROVIDE DRY AND COLD CONDITIONS THURSDAY
NIGHT. NEXT COLD FRONT APPROACHES WITH A CHANCE FOR SNOW SHOWERS
LATER FRIDAY INTO FRIDAY NIGHT. TEMPERATURES WILL BE BELOW NORMAL
THROUGH THE PERIOD.

.LONG TERM /SATURDAY THROUGH TUESDAY/...
COLD NORTHWEST FLOW WILL BE REINFORCED BEHIND COLD FRONT AND BRING
SOME SNOW SHOWERS NORTH AND RIDGES SATURDAY BEFORE HIGH PRESSURE
BUILDS IN ENDING PRECIP SATURDAY NIGHT.

COLD RIDGE OF HIGH PRESSURE WILL DOMINATE REMAINDER OF WEEKEND
WITH MODERATING TEMPERATURES EARLY NEXT WEEK.

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
DIFFICULT AND LOW CONFIDENCE FORECAST THROUGH TONIGHT. WILL
CONTINUE WITH A FORECAST OF IFR TO LIFR CIGS THROUGH THIS MORNING.
THERE SHOULD BE A SLOW IMPROVEMENT TO MVFR FROM PIT NORTH THIS
AFTERNOON. RAIN WILL CONTINUE TO MOVE ACROSS THE SOUTHERN HALF OF
THE REGION THIS MORNING. RAIN WILL LIKELY CHANGE TO SNOW FROM
WEST TO EAST DURING THE LATE MORNING/AFTERNOON. FKL WILL BE FAR
ENOUGH TO THE NORTH TO MISS THE PRECIP. TIMING THE CHANGE OVER TO
SNOW WILL BE DIFFICULT AS THE COLDER AIR WILL TAKE ITS TIME MOVING
SOUTHWARD. EXPECT ALL PORTS TO CHANGE TO SNOW BY LATE AFT. THE
GREATEST EFFECT FROM THE SNOW WILL LIKELY BE FELT AT LBE AND MGW
AND THESE PORTS WILL REQUIRE LOWER RESTRICTIONS IN VIS TODAY.

OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY...
MVFR RESTRICTIONS MAY LINGER INTO WEDNESDAY NIGHT BEFORE HIGH
PRESSURE BUILDS IN FOR THURSDAY AND FRIDAY. NEXT CHANCE FOR
RESTRICTIONS WILL BE WITH THE SHORTWAVE PASSAGE SATURDAY. VFR WILL
RETURN SUNDAY.

AREA FORECAST DISCUSSION

NWS MARQUETTE MI

354 PM EST WED DEC 7 2011

.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED CYCLONIC MID/UPPER LEVEL FLOW
AROUND A VORTEX OVER HUDSON BAY BRINGING NRN STREAM WNW FLOW FROM
SRN CANADA INTO THE UPPER GREAT LAKES. AN UPSTREAM SHORTWAVE TROUGH WAS
MOVING THROUGH SRN MANITOBA WITH ANOTHER TRAILING SHRTWV OVER NRN
SASK. AT THE SFC...WINDS WERE VEERING W TO WNW BEHIND A TROUGH/FRONT
THAT MOVED THROUGH THIS MORNING. A TRAILING ARCTIC FRONT NEAR LAKE
WINNIPEG WAS DROPPING TOWARD THE AREA WITH MUCH COLDER AIR BEHIND IT
WITH TEMPERATURES FROM -5 TO 5F OVER NORTHERN MANITOBA/SASK. VIS
LOOP INDICATED CLEARING SKIES OVER THE WEST HALF OF THE CWA AS DRIER
AIR MOVES INTO THE REGION. EVEN WITH 850 MB TEMPS AROUND
-11C...SKIES HAD CLEARED OVER MUCH OF WRN LAKE SUPERIOR.
&&

.SHORT TERM...TONIGHT AND THURSDAY

CLOUDS AND SCT LIGHT LAKE EFFECT SNOW SHOWERS ARE EXPECTED TO
REDEVELOP OVER WRN LAKE SUPERIOR INTO WRN UPPER MI THIS EVENING AS
GREATER LOW LEVEL MOISTURE MOVES TOWARD THE AREA...PER VIS LOOP.
PASSAGE OF THE SASK SHRTWV AND ARCTIC FRONT THU MORNING WITH
INCREASING 850-700 MB MOISTURE AND INVERSION HEIGHTS CLIMBING AROUND
8K FT WILL PROVIDE A SIGNIFICANT BOOST TO THE LAKE EFFECT SNOW. SNOW
GROWTH ALSO LOOKS FAVORABLE AS THE DGZ WILL BE RIGHT IN THE BEST
OMEGA/UPWARD MOTION. GIVEN MODEL QPF AND SNOW/WATER RATIOS
APPROACHING 30/1 WOULD NOT BE SURPRISED TO SEE PERIODS OF MODERATE
TO HEAVY SNOWFALL. THE MOST PERSISTENT LOW LEVEL CONV AND CHANCE FOR
GREATEST ACCUMULATION IS EXPECTED FROM FAR NE ONTONAGON COUNTY INTO
CENTRAL HOUGHTON COUNTY...FROM GREENLAND TO TWIN LAKES. INCREASINGLY
CONVERGENT WRLY FLOW. INCREASING WINDS GUSTING TO NEAR 30 MPH AT
TIMES ON THURSDAY WILL ALSO SHARPLY REDUCE VSBYS IN BLOWING SNOW AS
WELL AND CAUSE DRIFTING SNOW ACROSS THE ROADS. SO...WITH THE
LIKELIHOOD OF AN EXTENDED PERIOD OF LES...HEAVY SNOW AT TIMES...A
LAKE EFFECT SNOW WARNING WAS ISSUED. CONFIDENCE IN ACCUMULATIONS BY
LATE THURSDAY IS LIMITED BY UNCERTAINTY ON WHERE THE HEAVIER BANDS
WILL DEVELOP AND HOW LONG THEY WILL PERSIST. SNOWFALL GENERALLY FROM
3 TO 7 INCHES IS LIKELY WITH SOME HIGHER LCL AMOUNTS.

LOCATIONS NEAR LAKE SUPERIOR EAST OF MUNISING...FROM GRAND MARAIS TO
TWO HEART MAY ALSO SEE A PERIOD OF HEAVIER LES IF THE EXPECTED
DOMINANT BAND SAGS SOUTHWARD WITH SLIGHTLY VEERING WINDS THU.
UNCERTAINTY REMAINS WHETHER THE HEAVIER SNOW WILL REMAIN OFFSHORE OR
MOVE INLAND...SO NO HEADLINES WERE ISSUED AT THIS TIME.

.LONG TERM /THURSDAY NIGHT THROUGH NEXT WEDNESDAY/...

SIGNIFICANT LAKE EFFECT SNOW IS THE MAIN CONCERN FOR THE INITIAL
PORTION OF THE LONG TERM.

LARGE SCALE TROUGH WITH COLDEST AIR OF SEASON THUS FAR TO PUSH INTO
THE AREA SETTLES OVER MUCH OF THE EASTERN CONUS TO END THE WEEK.
NOT MUCH IN THE WAY OF LARGER SCALE SHORTWAVES THAT WILL BRING
WIDESPREAD SNOW TO THE AREA...BUT SIGNIFICANT LK EFFECT FOR WEST
FLOW AREAS IS LIKELY AS H85 TEMPS TUMBLE TO AROUND -18C BY FRIDAY.
MODEL SOUNDINGS INDICATE LAKE INDUCED CAPES AOA 600J/KG WHILE LAKE
EQUIBRIUM LEVELS ARE OVR 10 KFT AGL. HIGHER OVERWATER INSTABILITY
IS SUPPLEMENTED BY STRONG LOW-LEVEL (SFC-H95) CONVERGENCE.

MODELS ARE ACTUALLY IN VERY GOOD AGREEMENT WITH OVERALL SCENARIO
THOUGH SUBTLE SHIFTS IN BLYR WINDS MAKE ALL THE DIFFERENCE AS TO
THE LOCATIONS THAT END UP WITH THE HIGHEST SNOW AMOUNTS. BY LATE
THURSDAY AND INTO THURSDAY NIGHT...SHEAR WITHIN THE SFC-H8 LAYER
IS QUITE LOW...LEADING TO BETTER CHANCE THAT DOMINANT BANDS CAN
ORGANIZE. WINDS BECOMING WESTERLY AT 925MB WITH WSW OR SW SFC WINDS
OVR UPR MI (ENHANCED BY NIGHTTIME LAND BREEZES) WOULD FAVOR STRONGEST
CONVERGENCE/HEAVIER SNOW BANDS OVR WESTERN UPR MI FM ONTONAGON
THROUGH TWIN LAKES/PAINESDALE. WARNING WILL CONTINUE FOR THOSE AREAS
THROUGH LATE FRIDAY FOR THIS PROLONGED HEAVY LAKE EFFECT SNOW EVENT.
STORM TOTALS OVER A FOOT SEEM PRETTY LIKELY IF THE PRIMARY SNOW BAND
STAYS STATIONARY FOR REASONABLE AMOUNT OF TIME.

HIGHER TERRAIN AREAS OF REST OF HOUGHTON COUNTY WILL ALSO SEE
OFF-AND-ON HEAVIER SNOW SHOWERS. ALSO EXPECT SOME HEAVIER SNOW TO
OCCUR OVR SOUTHERN PORTIONS OF HOUGHTON COUNTY...MAINLY NORTH OF
M-38. ADVY WILL COVER THIS POSSIBILITY. EXPECT VERY LITTLE IF ANY
SNOW TOWARD KENTON/SIDNAW ALONG M-28. KEWEENAW COUNTY IS MORE OF A
QUESTION MARK AS THE MORE WNW BLYR WINDS THERE ARE NOT AS FAVORABLE.
STILL THOUGH...DEGREE OF INSTABILITY AND SUFFICIENT MOISTURE PRESENT
COULD LEAD TO LOCALIZED HEAVY AMOUNTS OVR HIGHER TERRAIN THERE AS
WELL. AN ADVISORY WILL HANDLE THIS FOR NOW...THOUGH LATER UPGRADE
COULD BE NEEDED. EXPECT QUIET WEATHER FOR REST OF THE CWA THURSDAY
NIGHT INTO FRIDAY. TEMPS WILL BE ON THE CHILLY SIDE THOUGH WITH
NIGHTTIME LOWS THURSDAY NIGHT TOWARD THE ZERO MARK OVR INTERIOR SW
UPR MI AND HIGHS ON FRIDAY MAINLY STAYING IN THE TEENS.

BY LATE FRIDAY...WEAKER TROUGH FCST TO SLIDE THROUGH THE AREA MAY
VEER WINDS TO MORE NW LEADING TO INCREASED CHANCES OF LAKE EFFECT
SNOW SHOWERS INTO FAR EASTERN SECTION OF CWA...MAINLY EAST OF
MUNISING AND WELL NORTH OF NEWBERRY. LAKE EFFECT SNOW PARAMETER
DEVELOPED BY NWS GAYLORD WHICH INCORPORATES 1000-850MB
SHEAR/850-700MB RH/H85 TEMPS INDICATES FAVORABLE SETUP FOR HEAVY
SNOW RATES IN THOSE EASTERN AREAS FRIDAY AFTN/FRIDAY EVENING.
SNOWFALL RATES UP TO 2 INCHES PER HOUR COULD OCCUR IN THOSE AREAS
AND HEADLINES MAY BE NEEDED AT SOME POINT. HOWEVER...WILL LEAVE
THOSE DECISIONS TO LATER SHIFTS AS EXPECT VERY LITTLE SNOWFALL IN
THOSE AREAS THROUGH FRIDAY MORNING.

TROUGH AND COLDER AIR SFC-H85 SLOWLY HEAD INTO LOWER GREAT LAKES
FRIDAY NIGHT INTO SATURDAY. WARM AIR ADVECTION STARTS UP BY SATURDAY
LEADING TO A PUSH OF ISENTROPIC ASCENT 285-290K (750-650MB) ACROSS
MUCH OF THE CWA. UVM IN THE LAYER FAIRLY STRONG...BUT TROUBLE IS
THERE IS DRY AIR LINGERING BLO H85 THRU THE DAY. COULD BE SOME
FLURRIES OR LIGHT SNOW SHOWERS...BUT BETTER SATURATION WILL KEEP THE
GREATER CHANCE OF ACCUMULATING SNOWS MORE INTO ONTARIO. GUSTY SW
WINDS WILL ADD CHILL TO THE AIR DESPITE SFC TEMPS REBOUNDING INTO
LOWER TO MIDDLE 20S.

FOR THE EXTENDED...TROUGH THAT WAS OVER THE AREA FOR MUCH OF THIS
WEEK IS FCST TO EASE INTO EASTERN CANADA LEADING TO MORE OF A ZONAL
FLOW PATTERN/WARMING TREND BY EARLY NEXT WEEK. WEAK SHORTWAVE/WARM
FRONT SLIDES ACROSS UPR LAKES MONDAY BUT MOISTURE IS MINIMAL SO DO
NOT EXPECT A WHOLE LOT OF PRECIPITIATON. BETTER CHANCE OF
PRECIPITATION WOULD BE FARTHER NORTH CLOSER TO H85-H7 FRONTOGENESIS
AND RIGHT ENTRANCE REGION OF UPR JET OVR ONTARIO. ANOTHER TROUGH
FORMING OVR SCNTRL CANADA IS FCST TO MOVE ACROSS THE UPR GREAT LAKES
LATE TUESDAY INTO WEDNESDAY. DIFFERENCES BEGIN TO APPEAR WITH REGARD
TO DEPTH OF TROUGH BY WEDNESDAY. LAST TWO RUNS OF GFS CLOSED THE
TROUGH OFF OVR UPR MISSISSIPPI RIVER VALLEY/UPR LAKES. MEANWHILE...
RECENT RUNS OF THE ECMWF AND PREVIOUS RUNS OF GFS INDICATED MORE OF
A PROGRESSIVE SYSTEM...WITH DEEPER SYSTEM FORMING OVR CNTRL PLAINS
MID-LATE NEXT WEEK. ENSEMBLES FM GFS/ECMWF/CANADIAN SHED LITTLE
LIGHT ON THE SUBJECT WITH MIXED SIGNALS IN TERMS OF STRENGTH AND
MOVEMENT OF THE TROUGHS. DOES SEEM THAT AT LEAST ECMWF WOULD SUPPORT
BETTER CHANCE OF ORGANIZED PRECIPITATION IN THE MIDWEEK TIME FRAME.
WILL NOT PUT TOO MUCH EMPHASIS ON THIS YET THOUGH AS SUPPORT FOR
THAT IDEA REMAINS LIMITED SUPPORT LOOKING AT OTHER AVILABLE GUIDANCE
AND ENSEMBLES.
&&

.AVIATION /FOR THE 18Z TAF ISSUANCE/
DRIER AIR MOVING IN ON WESTERLY WINDS BEHIND A TROUGH WILL BRING
IMPROVING CONDITIONS FOR KIWD/KSAW TO VFR BY LATE THIS AFTERNOON.
HOWEVER...KCMX IS EXPECTED TO RETAIN MVFR CIGS THIS AFTERNOON WITH
LAKE MOISTURE CONTRIBUTION AND UPSLOPE WNW FLOW. AS COLDER ARCTIC
AIR MOVES INTO THE REGION LATE TONIGHT...LAKE EFFECT SNOW SHOWERS
WILL INCREASE ACROSS THE KEWEENAW. HOWEVER...THE LOWER END VSBY WITH
SHSN...DOWN TO AROUND 1SM SHOULD HOLD OFF UNTIL AROUND 12Z/THU. THE
WEST WINDS WILL NOT BE FAVORABLE FOR ANY LES AT KSAW/KIWD...BUT LOW
LEVEL MOISTURE IN THE COLD AIRMASS WILL SUPPORT MVFR CIGS.
&&

.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...

WINDS MAINLY OUT OF A WESTERLY DIRECTION OVER 20KTS WILL PREVAIL THROUGH
MUCH OF THE PERIOD. THE WINDS/WAVES ALONG WITH PLENTY OF COLD AIR
WILL RESULT IN THE POTENTIAL FOR FREEZING SPRAY TONIGHT INTO FRIDAY.
WESTERLY GALES ARE EXPECTED TO RETURN AROUND SUNRISE THURSDAY BEHIND
AN ARCTIC FRONT OVER THE WEST HALF...BEFORE EXTENDING THROUGH CENTRAL AND
EASTERN LS THROUGH EARLY THURSDAY EVENING.

EXPECT STRONG HIGH PRESSURE ACROSS SW CANADA TO WEAKEN ACROSS THE
PLAINS STATES FRIDAY...WHILE EXTENDING A RIDGE ACROSS LS BY FRIDAY
NIGHT. LOW PRESSURE OVER MANITOBA SATURDAY MORNING WILL SLIDE ACROSS
ONTARIO SATURDAY AFTERNOON AND EVENING...WHILE DRAGGING A TROUGH
OVER LS. A PERIOD OF SW GALES IS POSSIBLE SATURDAY AHEAD OF THE LOW.
ANOTHER LOW PRESSURE SYSTEM...OVER THE DAKOTAS SUNDAY MORNING...WILL
LIKELY FILTER ACROSS LAKE SUPERIOR SUNDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING FROM 1 AM THURSDAY TO 7 PM EST FRIDAY
FOR MIZ002-003.

LAKE EFFECT SNOW ADVISORY FROM 1 AM THURSDAY TO 7 PM EST FRIDAY
FOR MIZ001-084.

LAKE SUPERIOR...
GALE WARNING FROM 7 AM THURSDAY TO 1 AM EST FRIDAY FOR
LSZ263>267.

LAKE MICHIGAN...
NONE.
&&

SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLB

AREA FORECAST DISCUSSION

NWS MARQUETTE MI

1245 PM EST WED DEC 7 2011

UPDATED AVIATION DISCUSSION FOR 12Z TAFS

.SYNOPSIS...

WV IMAGERY AND RUC ANALYSIS REVEAL AN ACTIVE NRN STREAM FLOW TAKING
SHAPE OVER WRN AND CENTRAL CANADA INTO THE NRN CONUS. ONE SHORTWAVE
MOVING THROUGH NRN ONTARIO AND THE NRN PLAINS WILL CONTINUE EAST
ACROSS THE UPR GREAT LAKES PUSHING A COLD FRONT ACROSS THE REGION
TODAY. A SECOND CLIPPER SHORTWAVE MOVING THROUGH ALBERTA IS
EXPECTED TO MOVE ACROSS THE UPPER GREAT LAKES LATE TONIGHT INTO
THURSDAY USHERING IN THE COLDEST AIR OF THE SEASON AND SETTING UP A
PROLONGED LAKE EFFECT SNOW EVENT FOR NORTHWEST UPPER MI AND POSSIBLY
SHORELINE AREAS FROM GRAND MARAIS EAST TO WHITEFISH POINT.
&&

.DISCUSSION...

MAIN FCST CONCERN IS LES POTENTIAL WITH THE FRONT/TROUGH MOVING
THROUGH THE AREA TODAY AND THEN SECONDARY CLIPPER SYSTEM/ARCTIC PUSH
MOVING THROUGH LATE TONIGHT INTO THURSDAY.

TODAY...SATELLITE TRENDS AND MODEL RH/Q-VECT CONV FIELDS SUGGEST
LOWER CLOUDS OVER WESTERN UPPER MI WILL CONTINUE TO SPREAD EAST
ACROSS THE REST OF THE FCST AREA LATER THIS MORNING. COMBINATION OF
LOW-LVL CONV AND MODERATE Q-VECT CONV ALONG INCOMING COLD FRONT AND
CAA BEHIND THE FRONT SHOULD BRING SOME LIGHT SNOW TO NRN SECTIONS OF
FCST AREA TODAY. LOOK FOR ANY LES ACCUMS GENERALLY LESS THAN AN
INCH.

PASSAGE OF CLIPPER SHORTWAVE LATE TONIGHT SHOULD PROVIDE A BRIEF
PERIOD OF ENHANCEMENT TO LES ACCUMS LATE TONIGHT INTO THURSDAY
MORNING AS 850 MB TEMPS LOWER TO AROUND -15C BY 12Z WED. SNOW GROWTH
ALSO LOOKS FAVORABLE AS THE DGZ WILL BE RIGHT IN THE BEST
OMEGA/UPWARD MOTION. GIVEN MODEL QPF AND SNOW/WATER RATIOS
APPROACHING 30/1 WOULD NOT BE SURPRISED TO SEE A QUICK 4-7 INCHES OF
LES OVER THE KEWEENAW PENINSULA AND PERHAPS OVER THE LAKE SUPERIOR
SHORELINE EAST OF PICTURED ROCKS WHERE A DOMINANT LES BAND COULD SET
UP IN AN INCREASINGLY CONVERGENT WRLY FLOW. INCREASING WINDS GUSTING
TO NEAR 30 MPH AT TIMES ON THURSDAY WILL ALSO SHARPLY REDUCE VSBYS
IN BLOWING SNOW AS WELL AS CAUSE DRIFTING OF SNOW ACROSS ROADS.

AFTER THE CLIPPER SHORTWAVE MOVES EAST THU MORNING...THE POTENTIAL
FOR HEAVIER LES BCMS LESS CERTAIN...AND THERE WILL LIKELY BE A LULL
IN THE SNOW FOR THU AFTERNOON INTO THU EVENING AS RDDG AND AN INFLUX
OF DRIER AIR FROM WEST OF THE LAKE MAY LIMIT LES ACCUMS.
BECAUSE OF THIS POSSIBLE LULL AND THE UNCERTAINTY OF DETAILS WITH
WHERE THE DOMINANT BAND WOULD SET UP LATE TONIGHT INTO THU MORNING
HAVE DECIDED TO JUST KEEP THE LES WATCH GOING FOR NRN
ONTONAGON...NRN HOUGHTON AND KEWEENAW COUNTIES FOR LATE TONIGHT INTO
FRI NIGHT. HOWEVER...WOULD NOT BE SURPRISED TO SEE A LES WARNING
ISSUED ON THE DAY SHIFT FOR THE ABOVE MENTIONED COUNTIES AND
POSSIBLY AN ADVISORY ISSUED FOR THE ERN ALGER AND NRN LUCE SHORELINE
AREAS.

LES COULD PICK UP AGAIN LATE THU NIGHT INTO FRI MORNING OVER THE
KEWEENAW PENINSULA AS MODELS SHOW THE MID-UPR LVL TROF AXIS MOVING
OVERHEAD PROVIDING ENHANCEMENT TO LES BANDS. 850 MB TEMPS NEAR -20C
AND INCREASED LOW-LVL CONVERGENCE WITH DEVELOPING LAND BREEZES WILL
LIKELY FOCUS ANOTHER DOMINANT LES BAND OVER KEWEENAW PENINSULA.
AGAIN SNOW GROWTH LOOKS PRETTY FAVORABLE AS OMEGA INTERSECTS DGZ.
LAND BREEZES MAY SPARE THE FAR ERN SHORELINE AREAS THE BRUNT OF
HEAVIER SNOW BY PUSHING BAND FAR ENOUGH OFFSHORE.

AS MID-LVL TROF AND DEEPER MOISTURE STARTS TO DEPART THE WESTERN
CWA...EXPECT LES TO BEGIN TO DIMINISH FRI AFTERNOON...BUT THERE WILL
STILL BE AT LEAST SOME ONGOING ACCUMULATION INTO FRI EVENING. WITH
WINDS SHIFTING MORE OUT OF THE WSW...EXPECT BEST BANDS TO BE OVER
THE NRN PORTIONS OF THE KEWEENAW AND OFFSHORE OF THE ERN CWA.

EXPECT LES TO COME TO AN END ON SAT...AS A CLIPPER SYSTEM DROPS
THROUGH SOUTHERN ONTARIO AND SHIFTS WINDS TO THE SW PRODUCING WAA
ALOFT. ANOTEHR CLIPPER SYSTEM AND ASSOC FRONT MAY BRING SOME MORE
MORE LIGHT SNOW TO THE AREA AGAIN ON MONDAY WITH SOME LIGHT LES
POSSIBLE INTO MONDAY NIGHT.
&&

.AVIATION /FOR THE 12Z TAF ISSUANCE/
DRIER AIR MOVING IN ON WESTERLY WINDS BEHIND A TROUGH WILL BRING
IMPROVING CONDITIONS FOR KIWD/KSAW TO VFR BY LATE THIS AFTERNOON.
HOWEVER...KCMX IS EXPECTED TO RETAIN MVFR CIGS THIS AFTERNOON WITH
LAKE MOISTURE CONTRIBUTION AND UPSLOPE WNW FLOW. AS COLDER ARCTIC
AIR MOVES INTO THE REGION LATE TONIGHT...LAKE EFFECT SNOW SHOWERS
WILL INCREASE ACROSS THE KEWEENAW. HOWEVER...THE LOWER END VSBY WITH
SHSN...DOWN TO AROUND 1SM SHOULD HOLD OFF UNTIL AROUND 12Z/THU. THE
WEST WINDS WILL NOT BE FAVORABLE FOR ANY LES AT KSAW/KIWD...BUT LOW
LEVEL MOISTURE IN THE COLD AIRMASS WILL SUPPORT MVFR CIGS.

.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...

WINDS MAINLY OUT OF A WESTERLY DIRECTION OVER 20KTS WILL BE COMMON
THROUGH MUCH OF THE PERIOD...ALONG WITH PLENTY OF COLD AIR WHICH
WILL RESULT IN THE POTENTIAL FOR FREEZING SPRAY TONIGHT INTO FRIDAY.
A TROUGH OF LOW PRESSURE ACROSS LS WILL EXIT EAST TODAY...BRINGING
AN END TO THE SW GALES OVER THE WESTERN HALF OF LS. WESTERLY GALES
MAY RETURN AROUND SUNRISE THURSDAY OVER THE WEST HALF...BEFORE
EXTENDING THROUGH CENTRAL AND EASTERN LS THROUGH EARLY THURSDAY
EVENING.

EXPECT STRONG HIGH PRESSURE ACROSS SW CANADA TO WEAKEN
ACROSS THE PLAINS STATES FRIDAY...WHILE EXTENDING A RIDGE ACROSS LS
BY FRIDAY NIGHT. LOW PRESSURE OVER MANITOBA SATURDAY MORNING WILL
SLIDE ACROSS ONTARIO SATURDAY AFTERNOON AND EVENING...WHILE DRAGGING
A TROUGH OVER LS. ANOTHER LOW PRESSURE SYSTEM...OVER THE DAKOTAS
SUNDAY MORNING...WILL LIKELY FILTER ACROSS LS SUNDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM LATE TONIGHT THROUGH LATE FRIDAY
NIGHT FOR MIZ001>003.

LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ263-264-266.

LAKE MICHIGAN...
NONE.
&&

SYNOPSIS...VOSS
DISCUSSION...VOSS
AVIATION...JLB
MARINE...KF

AREA FORECAST DISCUSSION

NWS MARQUETTE MI

715 AM EST WED DEC 7 2011

UPDATED AVIATION DISCUSSION FOR 12Z TAFS

.SYNOPSIS...

.DISCUSSION...

MAIN FCST CONCERN IS LES POTENTIAL WITH THE FRONT/TROUGH MOVING
THROUGH THE AREA TODAY AND THEN SECONDARY CLIPPER SYSTEM/ARCTIC PUSH
MOVING THROUGH LATE TONIGHT INTO THURSDAY.

.AVIATION /FOR THE 12Z TAF ISSUANCE/

LAKE EFFECT SNOW SHOWERS HAVE BEGUN AT CMX...DROPPING VIS DOWN TO
1SM ALREADY. IWD AND SAW ARE NOT IN SUCH A FAVORABLE PREDICAMENT
OVER THE NEXT 24 HOURS...AS THE MAINLY WESTERLY DOMINATING WINDS
KEEP THE LOWER CEILINGS/VIS SITUATED NEAR THE KEWEENAW PENINSULA.
THE STRONGEST WINDS WITH GUSTS OF 25 TO 30KTS WILL ALSO BE OVER CMX
TODAY...WITH OTHER SITES GUSTING AROUND 20KTS. OTHERWISE...SAW AND
IWD SHOULD REMAIN VFR OR HIGH END MVFR THROUGH THE PERIOD.
&&

.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...

EXPECT STRONG HIGH PRESSURE ACROSS SW CANADA TO WEAKEN
ACROSS THE PLAINS STATES FRIDAY...WHILE EXTENDING A RIDGE ACROSS LS
BY FRIDAY NIGHT. LOW PRESSURE OVER MANITOBA SATURDAY MORNING WILL
SLIDE ACROSS ONTARIO SATURDAY AFTERNOON AND EVENING...WHILE DRAGGING
A TROUGH OVER LS. ANOTHER LOW PRESSURE SYSTEM...OVER THE DAKOTAS
SUNDAY MORNING...WILL LIKELY FILTER ACROSS LS SUNDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM LATE TONIGHT THROUGH LATE FRIDAY
NIGHT FOR MIZ001>003.

LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ263-264-266.

LAKE MICHIGAN...
NONE.
&&

SYNOPSIS...VOSS
DISCUSSION...VOSS
AVIATION...KF
MARINE...KF

AREA FORECAST DISCUSSION

NWS MARQUETTE MI

629 AM EST WED DEC 7 2011

.SYNOPSIS...

.DISCUSSION...

MAIN FCST CONCERN IS LES POTENTIAL WITH THE FRONT/TROUGH MOVING
THROUGH THE AREA TODAY AND THEN SECONDARY CLIPPER SYSTEM/ARCTIC PUSH
MOVING THROUGH LATE TONIGHT INTO THURSDAY.

.AVIATION /FOR THE 06Z TAF ISSUANCE/

SW GRADIENT WINDS AHEAD OF APPROACHING COLD FRONT WILL SUPPORT LLWS
AT ALL TAF SITES OVERNIGHT. WINDS VEERING WRLY IN THE MORNING BEHIND
THE FRONT SHOULD BRING MVFR CIGS BACK INTO KIWD AND KCMX EARLY THIS
MORNING. FAVORABLE WRLY FLOW AT KCMX MAY RESULT IN WIND GUSTS
AOA 30 KTS AS WELL AS POSSIBLE LAKE EFFECT SNOW SHOWERS. DRIER AIR
WILL MOVE INTO KIWD WED MORNING AND KEEP LAKE EFFECT CLOUDS NORTH OF
THE SITE. KSAW WILL STAY VFR THROUGH THE PERIOD.
&&

.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...

EXPECT STRONG HIGH PRESSURE ACROSS SW CANADA TO WEAKEN
ACROSS THE PLAINS STATES FRIDAY...WHILE EXTENDING A RIDGE ACROSS LS
BY FRIDAY NIGHT. LOW PRESSURE OVER MANITOBA SATURDAY MORNING WILL
SLIDE ACROSS ONTARIO SATURDAY AFTERNOON AND EVENING...WHILE DRAGGING
A TROUGH OVER LS. ANOTHER LOW PRESSURE SYSTEM...OVER THE DAKOTAS
SUNDAY MORNING...WILL LIKELY FILTER ACROSS LS SUNDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM LATE TONIGHT THROUGH LATE FRIDAY
NIGHT FOR MIZ001>003.

LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ263-264-266.

GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162.

LAKE MICHIGAN...
NONE.
&&

SYNOPSIS...VOSS
DISCUSSION...VOSS
AVIATION...KF
MARINE...KF

AREA FORECAST DISCUSSION...UPDATED FOR 06Z TAFS

NWS MARQUETTE MI

1123 PM EST TUE DEC 6 2011

.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A SHEARED MID/UPPER LEVEL
TROUGH FROM NRN ONTARIO THROUGH NW WI AND IA INTO THE CNTRL PLAINS.
AN UPSTREAM SHORTWAVE TROUGH WAS MOVING THROUGH CNTRL MANITOBA. AT
THE SFC...SW FLOW WAS INCREASING OVER WRN LAKE SUPERIOR AND W UPPER
MI BTWN A DEPARTING RIDGE FROM QUEBEC INTO EAST UPPER MI AND A
TROUGH OVER MANITOBA. ALTHOUGH THE BACKING WINDS HAVE PUSHED THE
LAKE CLOUDS OFFSHORE OVER THE CNTRL AND WEST CWA...LOWER LEVEL
MOISTURE OVER WRN WI WAS STREAMING BACK INTO THE WEST...PER VIS
LOOP. MID LEVEL CLOUDS WERE ADVANCING THROUGH NW ONTARIO AND NRN MN
ASSOCIATED WITH WAA/295K ISENTROPIC LIFT AHEAD OF THE TROUGH.
&&

.SHORT TERM...TONIGHT AND WEDNESDAY

MAIN FCST CONCERN IS LES POTENTIAL WITH THE FRONT/TROUGH MOVING
THROUGH THE AREA.

SATELLITE TRENDS AND NAM/RUC 925-900 MB RH FCST SUGGESTS THAT THE
LOWER CLOUDS WILL CONTINUE TO SPREAD TO THE EAST THIS EVENING AND
THEN MOVE OUT OVERNIGHT AS WINDS BEGIN TO VEER MORE TO THE WNW.

MODERATE MID LEVEL QVECTOR CONV ASSOCIATED WITH THE TROUGH MOVING
INTO THE AREA WED MORNING WILL BRING AN INCREASE IN 850-700 MB
MOISTURE. WITH WINDS VEERING WRLY AND 850 MB TEMPS TO AROUND
-11C...CONDITIONS WILL BECOME MORE FAVORABLE FOR LES INTO THE
KEWEENAW LATE TONIGHT INTO WED MORNING. CAA DROPS 850 MB TEMPS TO
AROUND -14C DURING THE AFTERNOON...BUT THE DEEPER MOISTURE IS
EXPECTED TO DEPART. SINCE THE PERIOD WITH THE COMBINATION OF LOW
LEVEL CONV AND 850-700 MB MOISTURE IS BRIEF...ANY LES
ACCUMULATIONS ARE EXPECTED TO BE LIGHT...GENERALLY AN INCH OR LESS.
SCT -SHSN WILL ALSO AFFECT LOCATIONS E OF MUNISING DURING THE
AFTERNOON BUT AGAIN ACCUMULATIONS SHOULD BE LIGHT.

.LONG TERM /WED NIGHT THROUGH NEXT TUESDAY/...

COLD FRONT THAT WILL START THE COOLING TREND WILL BE EAST OF THE
AREA AT THE START OF THE PERIOD...WHICH WILL PRODUCED A PROLONGED
LAKE EFFECT SNOW PERIOD FOR PORTIONS OF UPPER MICHIGAN.

EXPECT SFC LOW TO BE STATIONED OVER HUDSON BAY THROUGH SAT...WHILE A
SFC HIGH SHIFTS FROM THE NRN PLAINS ON THURS TO THE OHIO RIVER
VALLEY BY FRI NIGHT. THIS WILL LEAD TO WINDS OUT OF A WNW DIRECTION
ON WED NIGHT INTO THURS...THEN BACKING TO THE W FOR THURS NIGHT INTO
FRI NIGHT. THIS A LITTLE MORE WESTERLY THAN SHOWN YESTERDAY AND WILL
LIKELY FOCUS PCPN OVER THE ERN CWA TO BE FROM GRAND MARAIS
EASTWARD...RIGHT ALONG THE SHORELINE. THINK LAND BREEZES WILL HELP
FOCUS A DOMINATE BAND EITHER RIGHT ALONG THE SHORELINE OR JUST
OFFSHORE AT TIMES DURING THE PERIOD. OVER THE WEST...FAVORABLE
LOCATIONS WILL BE FROM ROCKLAND THROUGH COPPER HARBOR...ESPECIALLY
OVER THE HIGHER TERRAIN.

EXPECT LES TO BE ONGOING AT THE START OF THE PERIOD...BUT WILL
REALLY BEGIN TO RAMP UP OVERNIGHT WED INTO THURS MORNING...AS
SHORTWAVE AND SECONDARY SFC TROUGH SWEEP ACROSS THE AREA. THIS WILL
INCREASE MID LVL MOISTURE AND START A DOWNWARD TREND IN H850 TEMPS
FROM -14C /DELTA-T OF 19/ TO -20C OVER THE W AND -18C OVER THE E.
THESE VALUES DON/T LOOK AS COLD AS YESTERDAY FOR THE THURS/FRI TIME
FRAME...WHICH WILL BE MORE FAVORABLE FOR THE LES POTENTIAL...AS THE
DGZ WILL BE RIGHT IN THE BEST OMEGA. IN ADDITION...MODELS SHOWING A
MORE MOIST LLVL...WITH LESS SUB CLOUD LAYER DRY AIR. THIS ALLOWS THE
BEST LK INDUCED FORCING TO BE LOCATED DIRECTLY IN OR THE TOP HALF OF
THE DGZ AND AID FOR FASTER ACCUMULATION. THUS...HAVE BUMPED UP SLR
UP SLIGHTLY INTO THE LOW/MID 20S...ALTHOUGH NOT QUITE AS HIGH AS
SEEN ON SOME OF THE CARIBOU SLR VALUES.

MIGHT BE A LITTLE LULL IN LES OVER THE WEST ON THURS AFTN...AS DRIER
AIR ABOVE H800 MOVES THROUGH AND LOWERS THE INVERSION HEIGHTS. THIS
WILL BE SHORT LIVED AS NEXT WAVE OF DEEPER MOISTURE MOVES IN AND
INVERSION HEIGHTS RISE ON THURS NIGHT WITH THE UPPER TROUGH MOVING
OVERHEAD. EVEN WITH THIS LULL...THERE WILL STILL BE GUSTY WINDS THAT
WILL CREATE BLOWING/DRIFTING SNOW ALONG THE LK SUPERIOR SHORELINE
WITH THE FAIRLY FLUFFY SNOW THAT WILL HAVE FALLEN WED NIGHT INTO
THURS MORNING.

FRI DEEPER MOISTURE STARTS TO DEPART THE WEST DURING THE
DAY...STARTING TO DIMINISH LES INSTENSITY...BUT WILL STILL BE
ONGOING THROUGH FRI NIGHT. WITH WINDS SHIFTING MORE OUT OF THE
WSW...EXPECT BEST BANDS TO BE OVER THE KEWEENAW AND OFFSHORE OVER
THE E /ALTHOUGH A WEAK TROUGH COULD SLIDE THE BAND BACK ONSHORE FRI
NIGHT/.

AS FOR SNOWFALL AMOUNTS...LES PARAMETER EXCEEDS 2 FOR MUCH OF THE
PERIOD...WHICH ALONG WITH LK INDUCED CAPE VALUES EXCEEDING 700 J/KG
AND EQL/S IN THE 9-12KFT RANGE...THE POTENTIAL IS THERE FOR HEAVY
SNOWFALL ACCUMULATIONS. CURRENT FCST FROM 6Z THURS TO 6Z SAT HAS
12-20 INCHES OVER THE HIGHER TERRAIN FROM ROCKLAND TO CALUMET AND
SIMILAR TOTALS RIGHT ALONG THE LK SUPERIOR SHORELINE E OF GRAND
MARAIS. WILL LIKELY SEE A COUPLE PERIODS WHERE OUR 8IN/12HR WARN
CRITERIA WILL BE REACHED OVER THE WEST...SO HAVE PUT OUT A LES WATCH
FOR ONTONAGON THROUGH KEWEENAW COUNTIES. HAVE LIMITED CONFIDENCE IN
THE EAST WITH BAND LOCATION DUE TO THE LITTLE MORE WRLY WINDS AND
SOME LIKELY WANDERING OF THE BAND ON/OFF SHORE THROUGH THE
PERIOD...SO HELD OFF ON A WATCH FOR TIME BEING.

DAYS 4 THROUGH 7 /FRI NIGHT THROUGH NEXT TUESDAY/...

EXPECT LES TO COME TO AN END ON SAT...AS A CLIPPER SYSTEM DROPS
THROUGH SOUTHERN ONTARIO AND SHIFTS WINDS TO THE SW AND PRODUCES WAA
ALOFT. FINE DETAILS BECOME A LITTLE MORE MUDDLED FOR SUN THROUGH
TUES...AS NO MAJOR DISTURBANCES OR FEATURES AFFECT THE REGION. THIS
LEAVES THE AREA UNDER ZONAL FLOW ALOFT FOR SUN...AHEAD OF A
SHORTWAVE MOVING ACROSS THE AREA MON INTO MON NIGHT. WITH H850 TEMPS
AROUND -1C ON SUN...EXPECT TEMPS TO BE SLIGHTLY ABOVE NORMAL WITH
HIGHS IN THE LOWER 30S. SUN NIGHT INTO MON NIGHT SHOULD SEE A SFC
TROUGH NEAR THE UPPER GREAT LKS REGION...BUT WITH HOW WEAK IT
APPEARS TO BE WITH THE ZONAL FLOW...HAVE LIMITED CONFIDENCE ON PCPN.
THUS...WILL GO WITH A MOSTLY CLOUDY PERIOD...ALTHOUGH THE BEST
CHANCE FOR PCPN WILL BE MON INTO MON NIGHT. THESE CLOUDS WILL KEEP
OVERNIGHT LOWS FROM BEING TOO COLD AND KEEP TEMPS NEAR NORMAL FOR
MON INTO TUES.
&&

.AVIATION /FOR THE 06Z TAF ISSUANCE/

.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...

SW WINDS ARE EXPECTED TO INCREASE TO GALE FORCE TONIGHT INTO EARLY
WED...MAINLY OVER WESTERN AND NCNTRL LAKE SUPERIOR AHEAD OF A TROUGH
MOVING TOWARD THE REGION. AS WINDS VEER NW BEHIND THE TROUGH...WINDS
ARE EXPECTED TO DIMINISH INTO THE 20-30 KT RANGE. A WINTRY PATTERN
OF W-NW WINDS WILL THEN PERSIST THRU LATE WEEK WITH LAKE EFFECT SNOW
SHOWERS. GIVEN ARCTIC AIR PASSING OVER THE LAKE AND EFFICIENT
MIXING...EXPECT WINDS CONSISTENTLY 20-30 KT WITH ANOTHER PERIOD OF
GALES POSSIBLE AGAIN LATE WED NIGHT AND THURSDAY. COMBINATION OF
ARCTIC AIR AND STRONG WIND SHOULD RESULT IN FREEZING SPRAY WED NIGHT
INTO FRIDAY.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM LATE WEDNESDAY NIGHT THROUGH LATE
FRIDAY NIGHT FOR MIZ001>003.

LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EST WEDNESDAY FOR LSZ266.

GALE WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY FOR LSZ162.

GALE WARNING UNTIL 10 AM EST WEDNESDAY FOR LSZ263-264.

LAKE MICHIGAN...
NONE.
&&

SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB

AREA FORECAST DISCUSSION

NWS JACKSON MS

1153 AM CST WED DEC 7 2011

.UPDATE...

THIS AFTERNOON...LATEST VISIBLE IMAGERY TRENDS AND RUC GUIDANCE INDICATE
THAT THE SUBSIDENCE ON THE BACKSIDE OF THE TROUGH IS NOT ENOUGH TO
MIX OUT A MOIST THERMAL TROUGH ALONG THE MS RIVER AND COLD ADVECTION
STRATOCUMULUS ARE REGENERATING...SO HAVE DELAYED THE CLEARING SOME
AND LOWERED HIGHS A BIT BASED ON THESE TRENDS. STILL EXPECT CLEARING
SKIES FOR TONIGHT AS HEIGHTS RISE AND SURFACE HIGH PRESSURE SETTLES
OVER THE AREA.

.PREV DISCUSSION... /ISSUED 1005 AM CST WED DEC 7 2011/

UPDATE...

THE LIGHT SNOW EVENT IS WINDING DOWN QUICKLY AS THE INTENSE MID LEVEL
TROUGH SWINGS EASTWARD ACROSS THE ARKLAMISS. A FEW FLURRIES WILL
CONTINUE OVER THE GOLDEN TRIANGLE REGION LATE THIS MORNING...BUT WILL
GO AHEAD AND CANCEL THE WINTER WEATHER ADVISORY GIVEN NO ADDITIONAL
SNOWFALL ACCUMULATION AND SFC TEMPERATURES ABOVE FREEZING.

THE LATEST VISIBLE SATELLITE IMAGERY INDICATES STRONG SUBSIDENCE ON
THE BACK SIDE OF THE TROUGH IS ERODING THE STRATOCUMULUS DECK AND
EXPECT MOSTLY SUNNY SKIES TO ENVELOP THE FORECAST AREA AS WE GO
THROUGH THE AFTERNOON. THE FORECAST IS GENERALLY ON TRACK AND ONLY
MINOR ADJUSTMENTS ARE NECESSARY. /EC/

PREV DISCUSSION... /ISSUED 321 AM CST WED DEC 7 2011/

FOR TONIGHT...SFC HIGH PRESSURE WILL BUILD OVER THE AREA AND PROVIDE
GREAT RAD COOLING CONDITIONS. LOOK FOR ALL OF THE AREA TO FALL
BETWEEN 20-25 DEGREES. SOME UPPER TEENS ARE NOT OUT OF THE QUESTION
EITHER. WE WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR FOG TO
DEVELOP AS BOUNDARY LAYER CONDITIONS LOOK TO SUPPORT SUCH CONDITIONS
AFTER TEMPS FALL AND CROSSOVER AFTERNOON DEWPTS. COOL/COLD CONDITIONS
WILL EXIST FOR THU AND THU NGT AS THE SFC RIDGE WILL STILL BE OVER
THE REGION. /CME/

LONG TERM...FRIDAY THROUGH WEDNESDAY...TEMPERATURES WILL MODERATE A
BIT ON FRIDAY BEFORE ANOTHER REINFORCING DRY COLD FRONT MOVES
THROUGH FRIDAY AFTERNOON WITH HIGHS IN THE MID TO UPPER 50S. ANOTHER
COLD/BREEZY NIGHT IS ON TAP FRIDAY NIGHT WITH LOWS FALLING INTO THE
UPPER 20S. NORTHEAST FLOW AND COLD AIR ADVECTION WILL CONTINUE ON
SATURDAY WITH AFTERNOON HIGHS ONLY CLIMBING TO THE LOW 50S.

BEYOND SATURDAY THE GFS/ECMWF HAVE COME INTO A LITTLE BETTER
AGREEMENT THAN PREVIOUS RUNS. SUNDAY WILL START OUT COLD WITH LOWS
FALLING INTO THE MID 20S...BUT TEMPS WILL MODERATE A BIT DURING THE
AFTERNOON WITH HIGHS IN THE MID 50S. THE SURFACE HIGH WILL SHIFT
FURTHER EAST AND THE FLOW WILL BECOME MORE EASTERLY ON MONDAY. TEMPS
WILL MODERATE A BIT BY MONDAY AS H850/H925 TEMPS WARM A BIT WITH
HIGHS IN THE MID TO UPPER 50S. MOISTURE WILL BE ON THE INCREASE BY
TUESDAY AND THIS MAY ALLOW SOME SHOWERS TO DEVELOP INTO WEDNESDAY. A
MORE ACTIVE PATTER LOOKS LIKE IT WILL DEVELOP AS WE GET INTO THE
MID/LATE PART OF NEXT WEEK.

STUCK PRETTY CLOSE TO GUIDANCE TEMPS THROUGH THE PERIOD...BUT DID DO
THE USUAL CUTS TO GUIDANCE LOWS IN THE AREAS THAT GENERALLY COOL
BELOW GUIDANCE UNDER STRONG RADIATIONAL COOLING. ALSO CUT BELOW
GUIDANCE HIGHS ON SATURDAY AS H925/H850 TEMPS COMBINED WITH COLD AIR
ADVECTION SHOULD KEEPS HIGHS IN THE LOW 50S. STUCK WITH OR CLOSE TO
GUIDANCE POPS/TEMPS BEYOND SATURDAY./15/

.AVIATION...

MIX OF IFR AND MVFR CONDITIONS CONTINUE THIS MORNING AT
TAF SITES ACROSS THE AREA...BUT WILL IMPROVE FROM WEST TO EAST AS
SKIES CLEAR DURING THE AFTERNOON. OTHER THAN AT KGTR...WINTRY
PRECIPITATION HAS JUST ABOUT COME TO AN END AT SITES...WITH PATCHES
OF LIGHT RAIN FALLING ELSEWHERE AS AN STRONG UPPER TROUGH SWINGS
ACROSS THE REGION. LOOK FOR ANY PATCHY PRECIPITATION TO COME TO AN
END BY 18Z. NORTHWEST WINDS WILL AGAIN BE BREEZY BUT WILL DIMINISH
DURING THE LATE AFTERNOON AND OVERNIGHT. THERE IS A LOW END RISK FOR
SOME RESTRICTED VISIBILITIES LATE TONIGHT AS TEMPERATURES COOL AND
GROUND FOG DEVELOPS. IF THIS OCCURS...TEMPERATURES WILL BE WELL BELOW
FREEZING AND FREEZING FOG IS POSSIBLE. AT THIS TIME...THIS IS A LOW
PROBABILITY EVENT AND WILL NOT MENTION IN OFFICIAL TAFS. WITH THAT
SAID...A HEAVY FROST IS EXPECTED ACROSS THE ENTIRE AREA. /19/ &&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON 40 25 52 27 / 0 0 0 0
MERIDIAN 40 25 53 24 / 8 0 0 0
VICKSBURG 42 22 52 24 / 0 0 0 0
HATTIESBURG 45 26 53 28 / 0 0 0 0
NATCHEZ 43 24 52 28 / 0 0 0 0
GREENVILLE 39 24 48 26 / 5 0 0 0
GREENWOOD 39 23 51 24 / 11 0 0 0

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&

AREA FORECAST DISCUSSION...UPDATED

NWS ST LOUIS MO

926 PM CST THU DEC 8 2011

.UPDATE...
/922 PM CST THU DEC 8 2011/
GOING FORECAST LOOKS TO BE IN GOOD SHAPE. LIGHT SNOW HAS BEEN
REPORTED ACROSS PARTS OF NORTHEAST MISSOURI AND WEST CENTRAL
ILLINOIS WITH SOME MINOR ACCUMULATIONS. RUC CONTINUES TO SHOW WEAK
FRONTOGENESIS BETWEEN 925-850MB UP THERE...WITH ANOTHER AREA OF
FRONTOGENESIS FURTHER NORTHWEST ACROSS IOWA. THIS LARGER AND
STRONGER AREA OF FORCING WILL MOVE DOWN ACROSS NORTHEAST MISSOURI
AND WEST CENTRAL ILLINOIS LATER TONIGHT...BEFORE MOVING EAST AS
THE LOW-MID LEVEL SHORTWAVE MOVES INTO THE OHIO VALLEY.

CARNEY

.DISCUSSION...
/335 PM CST THU DEC 8 2011/

TONIGHT...LIGHT SNOW HAS BEEN FALLING ACROSS NEBRASKA THIS AFTERNOON
IN RESPONSE TO LOW-MID LEVEL FRONTOGENETICAL FORCING AND WEAK LARGE
SCALE ASCENT ASSOCIATED WITH THE SHORT WAVE MOVING OUT OF THE
CENTRAL ROCKIES. THIS SNOW HAS JUST BEGUN TO SPREAD INTO EXTREME
NORTHERN KANSAS...SOUTHWEST IOWA AND EXTREME NORTHWEST MISSOURI. THE
MAIN QUESTION FOR TONIGHT IS ITS LONGEVITY AS THE SYSTEM MOVES
EASTWARD. VIRTUALLY ALL OF THE MODEL GUIDANCE HAS SIGNIFICANTLY
BACKED OFF ON THE SOUTHWARD EXTENT OF MEASURABLE SNOWFALL ACROSS
NORTHERN MISSOURI INTO WEST CENTRAL ILLINOIS TONIGHT. THERE IS A
GENERAL SUGGESTION THE CURRENT AREA WILL SPLIT INTO TWO BANDS THIS
EVENING...ONE TRANSLATING EASTWARD INTO IOWA AND THE OTHER TRYING TO
SPREAD SOUTHEAST INTO NORTHWEST MISSOURI AND ULTIMATELY OUR CWA. THE
APPARENT PROBLEM IS THIS SOUTHERN BAND ENCOUNTERS RATHER DRY AIR
INTO THE LOWEST 1-2 KM AND STRUGGLES TO MAINTAIN ITS IDENTITY AS IT
MOVES INTO NORTHEAST MISSOURI THIS EVENING. THE DRY AIR SHOULD
CERTAINLY LIMIT ITS SOUTHERN EXTENT AS DEPICTED BY THE MODELS AND
HAVE LOWERED POPS AND ADDED THE MENTION OF FLURRIES CLOSER TO
INTERSTATE 70. FURTHER NORTH...THE FORCING REMAINS STOUT ENOUGH THAT
I THINK IT WILL BE ABLE TO OVERCOME THE DRIER AIR TO PRODUCE LIGHT
SNOWFALL ACCUMULATIONS. THESE SHOULD BE LESS THAN AN INCH AND BE
CONFINED TO THE AREA ALONG AND NORTH OF A SHELBINA-HANNIBAL LINE
WITH A DUSTING POSSIBLE A BIT FURTHER SOUTH OF THIS LINE.

GLASS

BY FRIDAY...FIRST SHORTWAVE TO SLIDE EAST OF FORECAST AREA...BUT
COULD STILL SEE SOME LINGERING FLURRIES...MAINLY ALONG AND NORTH
OF I-70 THROUGH MIDDAY. MODELS DO CONTINUE TO SHOW A SECONDARY
SHORTWAVE SLIDING THROUGH FORECAST AREA FRIDAY AFTERNOON AND
EVENING...SO HAVE HELD BACK CLEARING A BIT AND COULD SEE ANOTHER
ROUND OF FLURRIES WITH THIS SECONDARY WAVE...HAVE LEFT OUT FOR
NOW. AS FOR HIGH TEMPS...WITH NORTH WINDS AND PLENTY OF CLOUD
COVER...TEMPS TO STRUGGLE TO REACH THE UPPER 20S TO UPPER 30S.

SKIES TO CLEAR OUT BY LATE FRIDAY EVENING AND WITH LIGHT AND
VARIABLE WINDS...TEMPS TO DROP INTO THE TEENS MOST LOCATIONS.

BY SATURDAY...SURFACE RIDGE TO BEGIN MOVING OFF TO THE EAST ALLOWING
SOUTHERLY WINDS TO RETURN TO THE REGION. TEMPS WILL SLOWLY MODERATE
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. HIGHS ON SATURDAY WILL
BE IN THE 30S...THEN INTO THE LOW TO MID 40S BY SUNDAY THROUGH
TUESDAY...AND THEN INTO THE MID TO UPPER 40S BY WEDNESDAY...JUST
AHEAD OF NEXT WEATHER SYSTEM. MODELS CONTINUE TO ADVERTISE A WEAK
FRONT THAT WILL APPROACH THE AREA MONDAY NIGHT AND TUESDAY...BEFORE
WASHING IT OUT...BUT LITTLE IF ANY WEATHER IS EXPECTED WITH IT.

BEYOND THAT...A MORE VIGOROUS WEATHER SYSTEM DEVELOPING AND
AFFECTING THE FORECAST AREA BEGINNING ON WEDNESDAY. EXTENDED MODELS
NOW IN BETTER AGREEMENT WITH DEVELOPING SURFACE LOW OVER THE
TEXAS PANHANDLE...SLIDING NORTHEAST INTO THE FORECAST AREA BY
WEDNESDAY NIGHT. SHOULD SEE DECENT CHANCES OF PCPN IN THE FORECAST
AREA WEDNESDAY THROUGH THURSDAY. TIMING AND STRENGTH OF SYSTEM
STILL HARD TO PIN DOWN...SO FOR NOW WILL JUST KEEP CHANCE POPS
THROUGH THE PERIOD WITH PCPN IN THE FORM OF RAIN AS HIGH TEMPS TO
BE IN THE 40S AND 50S WITH OVERNIGHT LOWS ABOVE FREEZING.

BYRD

.AVIATION...
/548 PM CST THU DEC 8 2011/

THERE IS LITTLE CHANGE FROM PREVIOUS THINKING WITH THIS NEW SET
OF TAFS. RADAR IS SHOWING INCREASED AREA OF REFLECTIVITY FROM
KPPQ-KMBY-KSTJ THE PAST FEW HOURS...BUT WEBCAMS AND SURFACE
OBSERVATIONS INDICATE THAT THE SNOW IS ONLY REACHING THE GROUND
OVER NORTHWEST MISSOURI. THIS IS BECAUSE THE LOWER ATMOSPHERE IS
DRY AND IT WILL TAKE A WHILE FOR THIS PRECIPITATION TO REACH THE
GROUND. STILL THINK THAT NORTHEAST MISSOURI AND WEST CENTRAL
ILLINOIS INCLUDING KUIN WILL LIKELY SEE A PERIOD OF LIGHT SNOW
THAT WILL REDUCE VISIBILITIES TO MVFR AND ACCUMULATIONS OF 1 INCH
OR LESS BEFORE THE SNOW SLOWLY DIMINISHES LATE TONIGHT AND EARLY
FRIDAY. FARTHER SOUTH...STILL DOES NOT LOOK LIKE THERE WILL BE
MUCH MORE THAN FLURRIES WITH LITTLE RESTRICTIONS TO VISIBILITY AND
ONLY LOW CHANCES OF CEILINGS FALLING BELOW VFR. DRY WEATHER WILL
RETURN ON FRIDAY.

A COLD FRONT THAT IS ROUGHLY ALONG A KSPI-KSTL-KVIH LINE WILL PUSH
SOUTHEASTWARD TONIGHT. WINDS WILL REMAIN MAINLY LIGHT NORTHERLY
BEHIND THROUGH 12Z.

SPECIFICS FOR KSTL...COLD FRONT WILL MOVE SOUTHEAST OF THE
TERMINAL THIS EVENING WITH LIGHT AND VARIABLE WINDS WILL BECOMING
LIGHT NORTHERLY. STILL EXPECT SOME FLURRIES WITH VFR CONDITION
LATE THIS EVENING AND OVERNIGHT.

BRITT

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

WFO LSX

AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

925 PM CST Thu Dec 8 2011

.UPDATE...
/908 PM CST Thu Dec 8 2011/

Light snow has been steadily spreading across northern Missouri this
evening in advance of a weak midlevel shortwave and entrance quad of
a Great Lakes upper jet. Bulk of snow activity has been focused
across ern Neb and wrn IA where some modest frontogenesis has been
occurring within a weak baroclinic region in the 900-700 hPa layer.
This band of frontogenetical forcing is expected to shift southeast
into the northern portions of the forecast area tonight, and may even
increase a bit as convergence increases ahead of a northwesterly LLJ
over northern Iowa. Already getting reports of up to 1 inch of snow
across Atchison County MO, and wouldn`t be surprised to see another
inch or so across far northern MO as additional snow moves out of
southeast Nebraska. This would bring total snow amounts in the 1 to 2
inch range across areas north of Highway 36 and west of I-35. As the
upper wave shifts into the Great Lakes after 06Z, this
frontogenetical forcing will be quick to decrease, and expect this
area of snow to do the same as it shifts into north central and
northeast MO, with snowfall totals of an inch or less for these areas.
Temps have been slow to fall and just recently fell below freezing
across the northern forecast area, which allowed for some melting and
refreezing on roadways. As a result, have received reports of
numerous accidents in northwest MO. Will continue to highlight this
hazard in an SPS.

Further south, some broad synoptic-scale lift associated with the
upper jet may allow some weak snow to drift as far south as the I-70
corridor after midnight. However, low-level frontolysis will act
against any appreciable snowfall rates across this area, and do not
expect any accumulations other than a very slight dusting south of
the 36 Hwy corridor.

Hawblitzel

.DISCUSSION...

A combination of shortwave troughs, one moving eastward across
Oklahoma and a second digging southeast through Nebraska has allowed
light snow to develop over the northern portions of the CWA this
afternoon. Surface observations and Nebraska traffic cameras are
confirming that slow top down saturation is occurring over southeast
Nebraska and extreme northwestern Missouri. Precipitation produced
by weak frontogenesis and PVA is currently being enhanced by modest
upper dynamics provided from right entrance region of 140 knot upper
jet stretching from central Nebraska into the Great Lakes region.
Surface temperatures have climbed into the middle 30s in northern MO,
so much of the snow that has fallen has been lost to melting or is
only sticking to bridges or overpasses.

Into the evening hours, expecting a slow east southeast expansion of
very light snow into areas north of Highway 36 as an initial
shortwave pivot across SD/NE/IA. The primary question is how far
south snowfall may actually reach this evening and overnight. WV
indicates a secondary shortwave in eastern Alberta sliding down the
western edge of the larger central Canada upper trough. As this
trough reaches ND early this evening the base of the large upr
trough is projected to flatten, preventing low level moisture and
precip from sinking toward the I-70 corridor at all this evening. At
the same time, favorable upper jet dynamics are also forecast to shift
away from the area with precipitation intensity expected to
significantly diminish after midnight. Thus, will concentrate
precipitation chances over the northern CWA and continue to indicate
very light accumulations.

For Friday, the secondary upper trough will begin to dig into
Nebraska area early Friday morning. This trough may finally give
enough of a southward push to the low-level moisture axis that areas
along the Interstate 70 corridor may actually have the highest chance
for flurries towards daybreak. For temperatures, extensive cloud
cover along with reinforcing cold air advection will keep
temperatures below normal in most locations. Wouldn`t be surprised to
see a few additional flurries develop Friday afternoon.

Friday night into Saturday: A 1037 MB surface high will travel
across the cwa Friday night and should push overnight low
temperatures below normal. A slight warmup will begin for Saturday
as warm advection commences and surface winds turn to the
southwest.

Dux

Medium Range (Sunday through Thursday)...

Good model agreement early in the period begins to degrade by the
middle of next week as a significant western hemisphere pattern
realignment commences. A seasonably deep negative height anomaly
center off the California coast will slowly progress into the
southern Rockies in response to northern stream influences;
primarily a kicker wave diving southeast into the Pacific northwest.
Continuity among all operational models has been poor regarding the
speed and track of this system into the plains during the midweek
time frame, but in general the GFS has been faster and further south
along the I-40/I-44/I-70 corridor (typical bias), while the ECMWF
lifts the system northeast slower in the face of stronger ridging
through the Great Lakes (more typical evolution). Compounding the
forecast challenge is GFS and CMC ensemble members display an
extremely large spread of solutions, in some cases becoming
completely out of phase by the end of the period. Thus, while
forecast confidence early in the period is fair, this confidence
deteriorates to well below average by the end of the period.

Surface high pressure extending from the Ohio River Valley through
the mid Atlantic coast will allow warming return flow to envelope
the lower Missouri River valley late in the weekend through early
next week. Initially, ridging along the Gulf coast will trap better
moisture return well to the south, however eventually a modified
boundary layer subtropical plume will become caught in the LLJ axis
and transported north. Would not be surprised to see a period of
drizzle/sprinkles/very light showers at some point Sunday night or
Monday (most bullishly advertised by the recent ECMWF runs), but
areal extent, intensity questions, and timing uncertainty do not
justify very high pops at this time. And while operational models
indicate very good chances for rainfall on Wednesday, the
aforementioned spread in ensembles suggests conservative pops for
the time being (and would expect models to continue to jump around
in successive iterations). The only more highly certain aspect of
this forecast package is the likelihood for average to above average
temperatures through the period, with the possibility that a few
periods could end up much warmer than currently forecast based on
cloud cover or lack thereof.

.AVIATION...

For the 00Z TAFs...Focus is on the area of light snow moving into
northern Missouri. Expect the bulk of this activity to stay near and
north of the STJ-IRK corridor, with only very light snow and minimal
impacts expected across the MCI-COU corridor. It is not out of the
question that snow with IFR conditions could drop as far south as MCI
around 06Z. For now, the chances of this appear low enough that only
TEMPO MVFR seems warranted in the TAF. NAM and RUC forecast soundings
suggest low-end MVFR or IFR cigs developing later tonight as the snow
tapers off. Not 100% sold on this, but given the model consensus,
will include at least low-end MVFR for now.

Hawblitzel

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&

WFO EAX

AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

530 PM CST Thu Dec 8 2011

...UPDATED AVIATION DISCUSSION...

.DISCUSSION...

Dux

Medium Range (Sunday through Thursday)...

.AVIATION...

Hawblitzel

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&

WFO EAX

AREA FORECAST DISCUSSION

NWS NORTH PLATTE NE

558 PM CST THU DEC 8 2011

.AVIATION...

SNOW CONTINUES OVER NORTH CENTRAL NEBRASKA EAST OF A LINE FROM KVTN
TO KTIF TO KLBF. SOME VISIBILITIES IN THE IFR CATEGORIES WITH SNOW.
CEILINGS WILL LOWER INTO MVFR CATEGORY EARLY THIS EVENING AND INTO
IFR CATEGORIES OVER SOUTHWEST NEBRASKA LATE THIS EVENING AND OVER
NIGHT. SOME LIGHT SNOW EXPECTED AT KVTN IN THE EARLY MORNING HOURS.
WEST TO NORTHWEST WINDS LESS THAN 10KTS.

.PREV DISCUSSION... /ISSUED 348 PM CST THU DEC 8 2011/

DISCUSSION...
BANDED FOLDS OF THETA E AND EPV CONTINUE TO PRODUCE LIGHT TO
MODERATE SNOW. THE RUC SUGGESTS THIS SNOW SHOULD MOVE OUT OF THE FCST
AREA BY 02-03 UTC THIS EVENING. ANOTHER WEAK WAVE ACROSS ERN MT THIS
AFTN SHOULD SLICE THROUGH NCNTL NEB MAINLY AFTER 06Z TONIGHT THROUGH
15Z FRIDAY. THE NAM...GFS AND GEM SUPPORT THIS SOLN.

WE CONTINUE THE PATCHY FREEZING DRIZZLE ACROSS PARTS OF SCNTL AND
SWRN NEB THIS EVENING. AN ARCTIC FRONT CURRENTLY NEAR KTIF WILL MOVE
SOUTH AND WASHOUT PERHAPS DRYING THE MIDLEVEL ALLOWING FOR LOW LEVEL
SATURATION AND FREEZING DRIZZLE.

BEHIND THE SECOND DISTURBANCE TONIGHT ANOTHER ARCTIC HIGH WILL BUILD
INTO THE UPPER MISSOURI BASIN AND BE CENTERED OVER WRN SD/ND FRIDAY
MORNING. THIS IS A BIG BREAK FOR THE FCST AREA AS LOWS OF -20F
OCCURRED BENEATH ACROSS WRN CANADA THURSDAY MORNING. THIS HIGH IS
FCST TO DRIFT THROUGH THE FCST AREA FRIDAY PRODUCING CLEAR SKIES AND
COLD WEATHER WITH HIGHS ONLY IN THE 20S. BY FRIDAY EVENING...LOW
PRESSURE WILL BE TRACKING CNTL CANADA PRODUCING AS WARM WESTERLY
H850MB FLOW WITH H850 TEMPS RISING TO NEAR 0C BY SATURDAY MORNING.
THUS LOWS SHOULD OCCUR AT OR BEFORE MIDNIGHT MOST AREAS AND THEN
WARM.

FOR SATURDAY...WEST AND SOUTHWEST WINDS CONTINUE WITH HIGHS IN THE
40S. WINDS TAKE A MORE SOUTHERLY TACK SUNDAY AHEAD OF A COLD FRONT
PROGGED TO MOVE THROUGH SUNDAY NIGHT AND MONDAY. STILL HIGHS SUNDAY
SHOULD RISE INTO THE 40S. A COLD FRONT MOVING THROUGH MONDAY IS
EXPECTED TO TAKE THE EDGE OFF HIGHS. 30S APPEAR TO BE THE OPERATIVE
MODE.

THE GEM...GFS AND ECM ARE IN GOOD AGREEMENT ON A SIGNIFICANT SHORT
WAVE TRACKING THROUGH THE CNTL PLAINS WEDNESDAY. TEMPS MIGHT BE WARM
ENOUGH FOR RAIN AS H10-5 THICKNESSES HOVER NEAR 546DAM AND H850MB
TEMPS -3 TO 0C. A CHANCE OF RAIN AND SNOW IS SHOWN EAST WITH SLIGHT
CHANCE OF SNOW WEST. THE GFS AND GEM SHOW EVAPORATIVE COOLING WHILE
THE ECM DOES NOT. THIS SYSTEM SHOULD EXIT WEDNESDAY NIGHT WITH
ANOTHER STRONG COLD FRONT DROPPING TOWARD THE FCST AREA.

HYDROLOGY...

A FLOOD WARNING FOR ICE JAMMING HAS BEEN ISSUED ON
THE NORTH PLATTE RIVER AT LEWELLEN. THE FLOOD WARNING WILL
CONTINUE UNTIL FURTHER NOTICE. WEATHER CONDITIONS FEATURING WARM
TEMPS DURING THE DAYTIME AND SINGLE DIGITS AT NIGHT THIS WEEKEND
COULD CAUSE THE JAMMING TO PERSIST.
&&

.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&

SHORT TERM/EXTENDED...POWER/CDC
AVIATION...POWER

AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

122 AM EST WED DEC 7 2011

.SYNOPSIS...
DRIZZLE AND PATCHY FOG WILL BE OVER THE REGION OVERNIGHT, AS A
STORM SYSTEM SLOWLY PULLS EASTWARD. A STRONGER STORM WILL DEVELOP
IN THE MID ATLANTIC REGION WEDNESDAY AFTERNOON THEN TRACK
NORTHEAST ALONG THE COAST WEDNESDAY NIGHT. A RAIN AND SNOW MIX IS
LIKELY INITIALLY WEDNESDAY EVENING, THEN AS COLDER AIR GETS DRAWN
INTO THE SYSTEM A PERIOD OF SNOW IS LIKELY, WITH SEVERAL INCHES OF
SNOW POSSIBLE FOR THE WESTERN CATSKILLS AND POCONOS.

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE FRONT IS ALONG OUR EXTREME EASTERN BORDER AT THIS HOUR.
TEMPERATURES REMAIN IN THE MID 50S OVER SULLIVAN COUNTY NY, WHILE
BROOME AND CHENANGO IS NOW IN THE UPPER 30S.

PATCHY DENSE FOG IS BEING OBSERVED, MAINLY ALONG THE HIGHER
ELEVATIONS. THE SURFACE OBS SHOW THAT THE DENSE FOG IS NOT
WIDESPREAD, SO WE WILL HOLD OFF ON A DENSE FOG ADVISORY.

SPOTTY DRIZZLE CONTINUES BEHIND THE FRONT. TEMPERATURES ARE
HOLDING IN THE MIDDLE TO UPPER 30S ACROSS OUR WESTERN AND CENTRAL
ZONES. LATEST RUC13 AND HRRR GUIDANCE SUGGESTS TEMPERATURES WILL
BARELY FALL OVERNIGHT, SO WE ARE NOT ANTICIPATING FREEZING
DRIZZLE. A FEW ISOLATED REPORTS ARE POSSIBLE...BUT THAT WOULD NOT
BE IN THE NEXT FEW HOURS.

.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
WEDNESDAY/WEDNESDAY NIGHT...UPPER LEVEL WAVE SHARPENS IN THE TN
VALLEY THEN MOVES INTO THE MID ATLANTIC REGION BY WEDNESDAY
EVENING. SFC LOW DEVELOPS IN RESPONSE TO THIS UPPER LEVEL WAVE
AND DEEPENS AS IT MOVES INTO THE MID ATLANTIC REGION BY WEDNESDAY
AFTERNOON. THIS FEATURE THEN TRACK NORTHEAST OFF THE SOUTHERN NJ
COAST AND INTO COASTAL NEW ENGLAND BY 12Z THURSDAY. MODEL TRENDS
HAVE BEEN TO TRACK SYSTEM FURTHER NORTH AND WEST LEADING TO MORE
PRECIP FOR FORECAST AREA. SNOW FORECAST VERY DIFFICULT WITH THIS
SYSTEM DUE TO FAST MOTION AND INITIALLY PRECIP WILL BE IN THE FORM
OF RAIN/SNOW THEN CHANGE TO ALL SNOW AS COLD AIR DEEPENS BEHIND
WAVE. FOR NOW IT LOOKS LIKE AND ADVISORY SNOWFALL FOR THE HIGHER
TERRAIN OF THE WESTERN CATSKILLS AND POCONOS WITH 3-5 INCHES
LIKELY. IF THE CONSENSUS TRACK CHANGES IT WILL HAVE A BIG IMPACT
ON TOTAL SNOW ACCUMS.

THURSDAY THROUGH FRIDAY...BEHIND THIS WAVE COLDER AIR WILL SPREAD
ACROSS CENTRAL NEW YORK WITH CONDITIONS MARGINAL FAVORABLE FOR
SOME LAKE EFFECT SNOW THURSDAY AFTERNOON THROUGH THURSDAY NIGHT.
WITH W/SW FLOW ACTIVITY WILL RESIDE MAINLY OVER NRN ONEIDA COUNTY
AND PARTS OF STEUBEN COUNTY AND THE FINGER LAKES REGION FROM LAKE ERIE.

ON FRIDAY THE NEXT UPPER LEVEL TROF WILL APPROACH THE REGION FROM
THE UPPER GREAT LAKES. WILL CONTINUE WITH CHC POPS FOR ALL BUT FAR
SE FA.

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
UPDATED AT 120 AM...GIVEN SHORT TERM CONCERNS WE HAVE MADE LTL CHG
TO THE MED RNG FCST...WHICH IS BASICALLY INDICATING QUIET WX.
PREV BLO...

XNTDD PD BEGINS WITH A NW FLOW OF COLD AIR AND PSBL LE SNOW SHWRS
FOR MUCH OF THE AREA. THIS CONTS INTO SAT AS THE BASE OF THE UPR
TROF MVES THRU. GRADUAL WRM UP WITH DRIER AIR BEGINS LATE
SUN...BUT RDG IS FLAT AND WSW FLOW IS SLOW TO BRING HIER TEMPS TO
THE AREA. SOME LE MAY LINGER ACROSS THE NRN ZONES INTO SUN. WRMR
ON MON WITH THE SFC HI OFF TO THE EAST AND CONTD DRY WSW FLOW. H8
TEMPS CLIMB ABOVE 0C. COLD FNT ON TUES WILL BRING BACK THE PSBLTY
OF SOME LGT RAIN OR SNOW SHWRS...AND SOME WEAK LAKE ENHANCEMENT.

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
WDSPRD IFR WILL PERSIST ACRS THE FCST AREA THRU 06Z THURSDAY. LOW
CIGS AND AREAS OF -RADZ/BR/FG THIS MRNG INTO THE EARLY AFTN HRS.
AS LOW PRES WORKS NWD LATER THIS AFTN...WE`LL SEE PCPN SWITCHOVER
TO SNOW DURING THE MID/LATE AFTN ACRS CNTRL NY AND THIS EVNG ACRS
NE PA. WINDS LGT NRLY THIS MRNG...INCRSNG TO 10-15 KTS THIS EVNG.

OUTLOOK...

THU...VFR.

FRI...MVFR SNOW SHWRS

SAT...VFR OCNL MVFR SNOW SHWRS.

SUN...VFR.

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...RRM
LONG TERM...DGM
AVIATION...

AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

1247 AM EST WED DEC 7 2011

PATCHY DENSE FOG IS BEING OBSERVED, MAINLY ALONG THE HIGHER
ELEVATIONS. THE SURFACE OBS SHOW THAT THE DENSE FOG IS NOT
WIDESPREAD, SO WE WILL HOLD OFF ON A DENSE FOG ADVISORY.

ON FRIDAY THE NEXT UPPER LEVEL TROF WILL APPROACH THE REGION FROM
THE UPPER GREAT LAKES. WILL CONTINUE WITH CHC POPS FOR ALL BUT FAR
SE FA.

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
XNTDD PD BEGINS WITH A NW FLOW OF COLD AIR AND PSBL LE SNOW SHWRS
FOR MUCH OF THE AREA. THIS CONTS INTO SAT AS THE BASE OF THE UPR
TROF MVES THRU. GRADUAL WRM UP WITH DRIER AIR BEGINS LATE
SUN...BUT RDG IS FLAT AND WSW FLOW IS SLOW TO BRING HIER TEMPS TO
THE AREA. SOME LE MAY LINGER ACROSS THE NRN ZONES INTO SUN. WRMR
ON MON WITH THE SFC HI OFF TO THE EAST AND CONTD DRY WSW FLOW. H8
TEMPS CLIMB ABOVE 0C. COLD FNT ON TUES WILL BRING BACK THE PSBLTY
OF SOME LGT RAIN OR SNOW SHWRS...AND SOME WEAK LAKE ENHANCEMENT.

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
WDSPRD IFR WILL PERSIST ACRS THE FCST AREA THRU 06Z THURSDAY. LOW
CIGS AND AREAS OF -RADZ/BR/FG THIS MRNG INTO THE EARLY AFTN HRS.
AS LOW PRES WORKS NWD LATER THIS AFTN...WE`LL SEE PCPN SWITCHOVER
TO SNOW DURING THE MID/LATE AFTN ACRS CNTRL NY AND THIS EVNG ACRS
NE PA. WINDS LGT NRLY THIS MRNG...INCRSNG TO 10-15 KTS THIS EVNG.

OUTLOOK...

THU...VFR.

FRI...MVFR SNOW SHWRS

SAT...VFR OCNL MVFR SNOW SHWRS.

SUN...VFR.

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...RRM
LONG TERM...DGM

AREA FORECAST DISCUSSION

NWS WILMINGTON NC

1232 AM EST WED DEC 7 2011

.SYNOPSIS...
MILD CONDITIONS ACCOMPANIED BY SHOWERS AND A FEW THUNDERSTORMS CAN
BE EXPECTED BY THIS AFTERNOON...PREVAILING INTO EVENING AHEAD OF
AN APPROACHING COLD FRONT. COLDER AIR WILL SPILL ACROSS THE REGION
BEGINNING THURSDAY...BRINGING CHILLY TEMPERATURES MORE TYPICAL OF
EARLY DECEMBER THROUGH MUCH OF NEXT WEEK.

.NEAR TERM /THROUGH TONIGHT/...
AS OF 944 PM TUESDAY...LATEST HRRR MODEL INDICATES POSSIBLE PCPN
ACROSS THE ADJACENT ATLANTIC WATERS LATE TONIGHT THAT COULD NIP THE
ILM COASTAL COUNTIES. TO ACCOMMODATE THIS POSSIBILITY...WILL
INDICATE LOW POPS FOR THE AREA AROUND AND INCLUDING CAPE FEAR. SW
FLOW ALOFT...AND SE-S FLOW AT THE LOWER LEVELS...WILL BOTH PROVIDE
THE NECESSARY MOISTURE FOR INCREASED CLOUD COVER. COULD SEE
WIDESPREAD 60S FOR TONIGHTS LOWS WHICH ARE THE NORMAL DAYTIME HIGHS
FOR THIS TIME OF THE YEAR...BIZARRE. FRONTAL DYNAMICS AND WEAK
IMPULSES OR S/W TROFS ALOFT RIDING NE ALONG IT...ARE PROGGED TO
REMAIN WEST OF THE ILM CWA OVERNIGHT. SOUTHERLY WINDS TO INCREASE
TONIGHT AHEAD OF THE FRONT...THUS PREVENTING ANY WIDESPREAD FOG
DEVELOPMENT.

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...A COLD FRONT WILL MOVE THROUGH THE AREA
WEDNESDAY AFTERNOON AND EVENING...BRINGING SCATTERED TO NUMEROUS
SHOWERS AND PERHAPS ISOLATED THUNDERSTORMS. THE GREATEST
POTENTIAL FOR PRECIPITATION LOOKS TO RUN FROM ABOUT 18Z THROUGH
ABOUT 03Z WITH WARM TEMPERATURES CONTINUING. AFTER THE FRONT PASSES
DURING THE EVENING...STRONG COLD AIR ADVECTION WILL
COMMENCE...USHERING IN A RETURN TO BELOW NORMAL TEMPERATURES FOR
THURSDAY AND THURSDAY NIGHT UNDER MAINLY CLEAR SKIES.

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...A RATHER DYNAMIC WEATHER PATTERN IS EXPECTED
TO UNFOLD THROUGH THE EXTENDED PERIOD WITH AT LEAST TWO UPPER-LEVEL
FEATURES EXPECTED TO BRING CLOUDS AND SOME CHANCES FOR RAIN.
EXTENDED-RANGE MODELS (GFS AND ECMWF) ARE IN GOOD AGREEMENT FRIDAY
AND SATURDAY...BUT THEN DIVERGE BEGINNING SUNDAY.

TWO ARCTIC HIGHS FRIDAY...ONE SITUATED EAST OF NEW ENGLAND AND A
SECOND OVER THE CENTRAL PLAINS STATES...WILL BE SEPARATED BY A
TROUGH/FRONT LYING JUST OFF THE CAROLINA COAST. AN UPPER LEVEL
DISTURBANCE STREAKING NORTHEAST FRIDAY EVENING WILL HELP INDUCE LOW
PRESSURE TO DEVELOP OFF THE COAST WITH A SHORT WINDOW FOR RAIN
POSSIBLE ALONG THE NC COAST AND OFFSHORE. OUR POP IS ONLY 20 PERCENT
AT ILM...WITH 10% POPS FARTHER WEST. AN ARCTIC COLD FRONT WILL PUSH
THROUGH THE AREA LATE FRIDAY NIGHT...FOLLOWED BY ARCTIC HIGH
PRESSURE BUILDING IN THROUGH MONDAY WITH MAINLY CLEAR SKIES. THE
ECMWF BEGINS TO DIVERGE FROM THE GFS HERE WITH ITS FORECAST POSITION
OF THE HIGH LYING A COUPLE HUNDRED MILES FARTHER SOUTH THAN THE GFS.
THE MAIN IMPLICATION HERE IS THAT A HIGH CENTERED CLOSER TO THE
CAROLINAS WOULD LIKELY GIVE US LIGHTER OVERNIGHT WIND SPEEDS AND
COLDER LOW TEMPERATURES SATURDAY AND SUNDAY NIGHTS.

MODELS DIVERGE FURTHER MONDAY INTO TUESDAY WITH THEIR HANDLING OF A
SHORTWAVE TROUGH MOVING NORTHEAST FROM TEXAS INTO THE CAROLINAS. THE
ECMWF DEVELOPS A LARGER AREA OF OVERRUNNING RAIN MONDAY INTO
TUESDAY...WHILE THE GFS REMAINS MUCH DRIER. THIS LIKELY DUE TO
DIFFERENCES IN DEGREE OF BACKING IN THE 850/700 MB FLOW...VERY
DIFFICULT TO DISCERN THIS FAR IN ADVANCE. WE HAVE INTRODUCED A 30
POP (RAIN) LATE MONDAY INTO TUESDAY ACKNOWLEDGING BETTER RUN-TO-RUN
CONSISTENCY IN THE ECMWF...BUT TEMPERED BY COLLABORATIVE THRESHOLDS
WITH SURROUNDING NWS OFFICES WHO ARE MAINTAINING A DRY FORECAST.

FORECAST TEMPERATURES THROUGH THE EXTENDED RANGE ARE GENERALLY A FEW
DEGREES WARMER IN THE ECMWF THAN IN THE GFS (WARMER 1000-500 MB
THICKNESSES AND WARMER 850 MB TEMPS). THE ONLY EXCEPTION MAY BE
SATURDAY AND SUNDAY NIGHTS WHERE THE FARTHER SOUTH POSITION OF THE
ARCTIC HIGH IN THE ECMWF COULD PRODUCE SOMEWHAT COOLER NIGHTTIME
LOWS THAN THE 12Z GFS INDICATES. OTHERWISE LATEST GFS MOS NUMBERS
ARE REASONABLE.

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...AS OF 06Z...MODERATE CONFIDENCE OVERNIGHT WITH MVFR STRATUS POSSIBLE
AT THE COAST. COLD FRONT WILL BRING PRECIP AND RESTRICTIONS ON
WEDNESDAY.

CAROLINAS REMAIN ENTRENCHED BETWEEN COLD FRONT CRAWLING EASTWARD THE
MTNS...AND HIGH PRESSURE RIDGING DOWN THE ATLANTIC SEA BOARD.
TIGHTENED PG IS KEEPING WINDS ELEVATED SO DO NOT EXPECT MUCH IN THE
WAY OF FOG OVERNIGHT...BUT HIGHER TD/S MAY PROMOTE A STRATUS THREAT.
HOWEVER...GUIDANCE HAS BACKED OFF CONSIDERABLY ON IFR
POTENTIAL...AND HAVE NOT SEEN ANY IFR STRATUS UPSTREAM. FOR THIS
REASON HAVE REMOVED IFR FROM INLAND TERMINALS AND EXPECT VFR TO BE
PREDOMINANT OVERNIGHT AT FLO/LBT. ILM/CRE/MYR MAY SEE AN ISOLATED
SHOWER OR MVFR CIG AS FLOW REMAINS MORE ONSHORE THAN PREVIOUSLY
ANTICIPATED. HAVE TEMPO MVFR AT ALL THE COASTAL TERMINALS FOR
POTENTIAL...BUT DO NOT EXPECT WIDESPREAD RESTRICTIONS OVERNIGHT.
WINDS WILL PERSIST FROM THE SOUTH AROUND 5 KTS.

AFTER SUNRISE EXPECT VFR...AND THE COLD FRONT WILL BEGIN TO IMPACT
THE AREA FROM THE WEST IN THE AFTN. THE CONTINUALLY TIGHTENING
GRADIENT WILL PRODUCE WINDS FROM THE S/SW OF 10-15 KTS GUSTING UP TO
25 KTS. SHOWERS WILL OVERSPREAD THE TERMINALS...FIRST AT LBT/FLO BY
LATE AFTN AND TO THE COAST DURING THE EVENING...AND HAVE INDICATED
CB AT THE INLAND TERMINALS WHERE SUFFICIENT INSTABILITY IN SOUNDINGS
SHOWS A POTENTIAL TSTM THREAT. PRECIP INDUCED VSBYS AND CIGS OF AT
LEAST MVFR ARE LIKELY...WITH IFR POSSIBLE IN THE HEAVIEST RAIN. COLD
FRONT WILL RACE THROUGH DURING WEDNESDAY NIGHT...TURNING WINDS TO
THE WEST BUT REMAINING STRONG THROUGH THE END OF THIS VALID PERIOD.
SKY CONDITIONS WILL RAPIDLY IMPROVE TO VFR BEHIND FROPA AS WELL.

EXTENDED OUTLOOK...VFR THROUGH THE EXTENDED.

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 944 PM TUESDAY...MODELS STILL INDICATING/PROGGING HIGHER WIND
SPEEDS ACROSS THE WATERS...WITH A REFLECTION WITH BUILDING SEAS.
OVERALL...MODELS THIS EARLY WINTER SEASON HAVE BEEN HAVING A
SOMEWHAT DIFFICULT TIME WITH OVER-FORECASTING WIND SPEEDS AND
BUILDING SEAS ACROSS THE ILM COASTAL WATERS IN THE WARM SECTOR AHEAD
OF APPROACHING STRONG COLD FRONTS. EXPECT SOME BLEEDING OF HIGHER
SEAS OFFSHORE INTO THE OUTER WATERS OF THE COASTAL WATERS...DUE TO
SSTS OFFSHORE IN THE 70S ALLOWING STRONGER WINDS ALOFT TO MIX TO THE
OCEAN SFC. S-SSW WINDS 10 TO 15 KT...AND SEAS 2 TO 4 FT...LIKELY
BUILDING TO 3 TO 5 FT...WITH THE HIGHER SEAS RESERVED ACROSS THE
OUTER WATERS. COULD OBSERVE SHRA OVER THE OFFSHORE WATERS TRACK INTO
THE COASTAL WATERS DURING THE OVERNIGHT PERIOD.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WINDS STEADILY INCREASE DURING THE DAY
WEDNESDAY FROM AROUND 20 KNOTS TO A RANGE OF 25-30 KNOTS BY
WEDNESDAY EVENING. GFS IS ADVERTISING 35 TO 40 KNOTS IN WAA BUT
WITH THE COOLER WATER TEMPERATURES...THIS LOOKS OVERDONE. THURSDAY
WILL SEE AN OFFSHORE FLOW THAT WEAKENS THROUGHOUT THE DAY. SEAS WILL
RAMP UP AS WELL WITH SOME EIGHT FOOTERS POSSIBLE LATE WEDNESDAY INTO
WEDNESDAY NIGHT BEFORE SUBSIDING TO 3 TO 4 FT THURSDAY AFTERNOON AND
EVENING. A SMALL CRAFT ADVISORY HAS BEEN RAISED FOR 18Z WEDNESDAY
THROUGH 12Z THURSDAY.

LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...AN EXTENDED PERIOD OF MODERATE TO STRONG
NORTHEAST WINDS ARE EXPECTED THROUGH THE WEEKEND AS ARCTIC HIGH
PRESSURE BUILDS INTO THE REGION. AN INVERTED TROUGH OFF THE COAST
FRIDAY WILL BE KICKED FARTHER OFFSHORE AS AN ARCTIC COLD FRONT MOVES
THROUGH THE AREA SATURDAY MORNING. THE ARCTIC HIGH WILL MOVE NORTH
OF THE AREA THROUGH THE WEEKEND WITH STRONG MODERATE TO STRONG NORTH
TO NORTHEAST WINDS. THESE WINDS WILL BUILD SEAS TO AS MUCH AS 6-7
FEET IN THE OUTERMOST PORTIONS OF THE COASTAL WATERS SATURDAY NIGHT
INTO SUNDAY...WITH LESS AGITATED CONDITIONS EXPECTED CLOSER TO SHORE.

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.

MARINE...SMALL CRAFT ADVISORY FROM 1 PM WEDNESDAY TO 8 AM EST
THURSDAY FOR AMZ250-252-254-256.

NEAR TERM...DCH/8
SHORT TERM...RAN
LONG TERM...TRA
AVIATION...JDW/8

AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

748 AM EST WED DEC 7 2011

.SYNOPSIS...
A COMPACT AND INTENSE UPPER TROUGH WILL MOVE FROM THE LOWER
MISSISSIPPI VALLEY INTO THE MID-ATLANTIC STATES BY THIS EVENING.
THIS WILL ALLOW A DYNAMIC LOW PRESSURE SYSTEM TO DEVELOP IN THE
LEE OF THE CENTRAL APPALACHIANS OVER NORTH CAROLINA AND VIRGINIA
BY THIS AFTERNOON AND INTENSIFY AS IT TRACKS NORTHEASTWARD OVER
THE DELMARVA PENINSULA BEFORE ACCELERATING NORTHWARD ALONG THE NEW
ENGLAND COAST INTO THE CANADIAN MARITIMES BY THURSDAY MORNING.
RAIN...HEAVY AT TIMES WILL CHANGE TO SNOW FROM NORTHWEST TO
SOUTHEAST AS COLD AIR WRAPS INTO THE BACKSIDE OF THE SYSTEM. SNOW
WILL END BY EARLY THURSDAY MORNING WITH SEASONABLY COLD AND MAINLY
DRY CONDITIONS PREVAILING INTO THE WEEKEND.

.NEAR TERM /UNTIL 7 PM THIS EVENING/...
MADE A SLIGHT NWD ADJUSTMENT TO NEAR TERM QPF AXIS AND TWEAKED
INCREASED INTENSITY OF RA TO WDSPRD/MODERATE. THE LAURELS MAY
CHANGE OVER A LITTLE SOONER THAN CURRENTLY FCST 15-16Z VS. 17-18Z
OTHERWISE CURRENT FCST REMAINS ON TRACK.

SFC OBS AND RUC DATA INDICATE THE WAVY SFC FRONT HAS PUSHED EAST
OF THE LWR SUSQ VLY. HIGHS SHOULD BE REACHED EARLY THIS MORNING
WITH STEADY TO FALLING TEMPERATURES EXPECTED THROUGH THIS EVENING.

A BROAD AREA OF LGT TO MOD RNFL HAS OVERSPREAD MUCH OF THE CWA AS
EXPECTED MAINLY S/E OF DUJ-BGM LINE. SATL DATA SHOWS APPROACHING
MID-UPPER LEVEL SHORTWAVE TROUGH MOVG THRU THE ARKLATEX PHASING
WITH AN INTENSIFYING UPPER JET MAXIMA...RESULTING IN A WELL
DEFINED AREA OF UPPER LEVEL DIVERGENCE AND THUS SUPPORTING INC
CVRG OF PCPN. STRENGTHENING LG SCALE LIFT WILL ENHANCE PCPN OVR
S-CENTRAL PA NEAR AXIS OF ABOVE NORMAL PWATS. DETERMINISTIC MODEL
AND ENSEMBLE GUID IS NOW IN VERY GOOD AGREEMENT IN SHOWING A MOD
TO HVY PCPN AXIS SETTING UP OVR S-CNTRL PA THRU THE AFTN WITH A
HIGH PROBABILITY IN 1 INCH QPF.

THE INITIAL SURGE OF PCPN WILL BE IN THE FORM OF RAIN BUT LOWERING
HEIGHTS/THICKNESS VALUES SHOULD ALLOW PCPN TO TRANSITION FROM RAIN
TO SNOW...ESPECIALLY AT HIGHER ELEVATIONS. THE LAUREL HIGHLANDS
SHOULD CHANGEOVER FIRST AROUND EARLY AFTN WITH LOCALLY HVY SNFL
RATES SUPPORTING SEVERAL INCHES OF ACCUM BY THIS EVE. THE TIMING
OF COOLING AND SNOW DURATION WILL BE CRITICAL TO HOW MUCH SNOW
OCCURS. THE TRANSITION TO SNOW SHOULD OCCUR LATE THIS AFTN INTO
THE EARLY EVE FURTHER E ACRS THE CNTRL MTNS AND EVENTUALLY THE LWR
SUSQ VLY.

.SHORT TERM /7 PM THIS EVENING THROUGH 6 AM THURSDAY/...
THE TIMING OF COOLING WILL LKLY BE EVEN MORE IMPORTANT DURING THIS
PD AS FOCUS FOR SNFL SHIFTS EWD INTO CNTRL AND ERN PA. MODELS
GENERATE A ADDNL 0.50-1 INCH LIQUID EQUIVALENT OVR THIS AREA IN
THE 00-06Z TIMEFRAME...THE OPTIMUM WINDOW FOR SIG ACCUMS OVR
CNTRL AND ERN AREAS. WARM BL AND SFC TEMPS WILL EVENTUALLY BE
OVERCOME BY STG DYNAMIC COOLING AND ENHANCED PCPN/SNFL RATES ESP
IN COMMA HEAD/DEFORMATION ZONE NW OF SFC LOW TRACK...BUT
LIMITED/UNCERTAIN DURATION OF TEMPS COLD ENOUGH FOR SNOW WILL LKLY
RESULT IN COMPLICATED ELEVATION DEPENDENCE AND THUS LIMIT ACCUMS
TO SOME EXTENT IN VALLEY AREAS. THEREFORE ONLY UPGRADED TO WINTER
STORM WARNINGS FOR SOMERSET AND SCHUYLKILL WHERE PROBABILITIES
FOR HEAVY SNOW ARE GREATER OVR THE HIGHER TERRAIN OF THE LAURELS
AND POCONOS. ELSEWHERE AN ADVISORY SHOULD BE SUFFICIENT GIVEN THE
COMPLEX NATURE OF ACCUM DIFFS WITH ELEVATION AND UNCERTAINTY ASSOC
WITH TIMING CHANGEOVER/TRANSITION. FOLLOWING DAYS OF LOW
CONFIDENCE AND LARGE MDL SPREADS..THERE IS GOOD MODEL AGREEMENT ON
THE STORM TRACK AND THEREFORE USED A CONSENSUS APPROACH IN
CONSTRUCTING QPF/SNOW AMTS. FINALLY WITH THE THREAT OF 2+ INCH QPF
AND SATURATED GROUNDS ISSUED FLOOD WATCH IN COORDINATION WITH
LWX/PHI FOR A PTN OF THE LWR SUSQ VLY.

.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS THE STRONG LOW PRESSURE SYSTEM CONTINUES TO MOVE THROUGH THE EAST
COAST A MORE ZONAL PATTERN WILL EXTEND ACROSS PA THROUGH THURSDAY.
EXPECT SEVERAL MAINLY DRY SHORT WAVES TO PROPAGATE THROUGH THIS
WEEKEND. MSTR-STARVED COLD FNT MARKING THE LEADING EDGE OF THE UPPER
MIDWEST H5 TROUGH AND ACCOMPANYING SEASONABLY COLD /-12 TO -14C AT
850MB/ AIR ALOFT WILL CROSS THE AREA FRI NIGHT INTO SATURDAY...WITH
LITTLE FANFARE OTHER THAN SOME LAKE ENHANCED/UPSLOPE SNOW SHOWERS
ALONG THE ALLEGHENIES. LONG RANGE MODELS DIFFER ON TIMING WITH THE
NEXT LONG WAVE TROUGH DIPPING SOUTH FROM CANADA. MOST GEFS ENSEMBLES
MOVE IT THROUGH EARLY SUNDAY...WITH ONLY A FEW MEMBERS SLOWING IT
DOWN. THIS IS IN LINE WITH THE EC AND NAM. AS TROUGH AXIS MOVES
THROUGH THE REGION THERE REMAINS THE POSSIBILITY OF SCATTERED SNOW
SHOWERS SATURDAY. SYSTEM IS MOISTURE STARVED SO ANY SNOW WILL
BE LIGHT ACCUMULATIONS. COLD AIR MASS WILL ENTRENCH ITSELF OVER THE
AREA THIS WEEKEND WITH TEMPERATURES IN THE 30S. DRY SOUTH WESTERLY
FLOW BEHIND THE WEEKEND SYSTEM WILL LEAD TO WARMING MILD TEMPS
THROUGH THE FIRS HALF OF NEXT WEEK.

.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
COLD FRONT CONTINUES TO SLOWLY SAG THRU THE LOWER SUSQ VALLEY.

REGION CONTINUES TO BE AFFECTED BY WIDESPREAD LIFR/MVFR.
ITERMITTENT SHOWERS AND PATCHY DENSE FOG WILL KEEP LOW CIGS
THROUGH THE MORNING AND EXPECT POOR FLYING CONDS TO CONTINUE
THROUGH THE TAF PERIOD...WITH PERIODS OF LIFR AND VLIFR CIGS/VSBYS
POSSIBLE.

COLD AIR WILL PUSH IN FROM THE WEST BY MID AFTERNOON WITH RAIN
CHANGING TO SNOW FROM WEST TO EAST. THE TRANSITION WILL BEGIN BY
15Z ACROSS THE NORTHWEST AND SLOWLY PROGRESS EASTWARD WITH
JST/AOO/UNV CHANGING OVER BETWEEN ABOUT 20-23Z. THE SOUTHEASTERN
TERMINALS WILL CHANGE TO SNOW BETWEEN ABOUT 23-03Z WED EVENING.

AFTER FRONTAL PASSAGE EXPECT CONDITIONS TO SIGINIFCANTLY
IMPROVE...AFTER 06Z. BY 12Z VFR CONDITIONS SHOULD DOMINATE AT ALL
TAF SITES. WIND SHEAR IS A POSSIBILITY WITH A LLJ ALONG THE
FRONT...EXPECT GUSTY WINDS AT AND BEHIND THE FRONT WITH WIND
GUSTS UP TO 30KTS POSSIBLE.

OUTLOOK...
WED...WIDESPREAD IFR/MVFR CONTINUING WITH A RAIN CHANGING TO SNOW
SCENARIO FROM WEST TO EAST THROUGHOUT THE DAY.

THU...NO SIG WX EXPECTED.

FRI...PM SHSN POSSIBLE NW MTNS.

SAT/SUN...NO SIG WX EXPECTED.

.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
THURSDAY FOR PAZ012-018-019-025>028-034-035-037-041-042-045-
046-049>053.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST THURSDAY
FOR PAZ017-024.
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST
THURSDAY FOR PAZ058.
WINTER STORM WARNING FROM NOON TODAY TO 7 AM EST THURSDAY FOR
PAZ033.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
THURSDAY FOR PAZ036-056-057-059-063>066.
FLOOD WATCH FROM 1 PM EST THIS AFTERNOON THROUGH THURSDAY
MORNING FOR PAZ059-065-066.

$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...CERU
AVIATION...CERU

AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

657 AM EST WED DEC 7 2011

SFC OBS AND RUC DATA INDICATE THE WAVY SFC FRONT HAS PUSHED EAST
OF THE LWR SUSQ VLY. HIGHS SHOULD BE REACHED EARLY THIS MORNING
WITH STEADY TO FALLING TEMPERATURES EXPECTED THROUGH THIS EVENING.

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
COLD FRONT CONTINUES TO SLOWLY SAG THRU THE LOWER SUSQ VALLEY.

REGION CONTINUES TO BE AFFECTED BY WIDESPREAD IFR/MVFR. EXPECT
POOR FLYING CONDS TO CONTINUE THROUGH THE TAF PERIOD...WITH
PERIODS OF LIFR AND VLIFR CIGS/VSBYS POSSIBLE.

COLD AIR WILL PUSH IN FROM THE WEST TOMORROW WITH RAIN CHANGING
TO SNOW FROM WEST TO EAST. THE TRANSITION WILL BEGIN BY 12Z
ACROSS THE NORTHWEST AND SLOWLY PROGRESS EASTWARD WITH JST/AOO/UNV
CHANGING OVER BETWEEN ABOUT 20-23Z. THE SOUTHEASTERN TERMINALS
WILL CHANGE TO SNOW BETWEEN ABOUT 23-02Z WED EVENING.

BY 12Z THURSDAY CONDITIONS WILL BE IMPROVING RAPIDLY WITH THE
STORM SYSTEM EXITING THE EAST COAST.

OUTLOOK...
WED...WIDESPREAD IFR/MVFR CONTINUING WITH A RAIN CHANGING TO SNOW
SCENARIO FROM WEST TO EAST THROUGHOUT THE DAY.

THU...NO SIG WX EXPECTED.

FRI...PM SHSN POSSIBLE NW MTNS.

SAT/SUN...NO SIG WX EXPECTED.

$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...CERU
AVIATION...CERU

AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

621 AM EST WED DEC 7 2011

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC OBS AND RUC DATA INDICATE THE WAVY SFC FRONT HAS PUSHED EAST
OF THE LWR SUSQ VLY. HIGHS SHOULD BE REACHED EARLY THIS MORNING
WITH STEADY TO FALLING TEMPERATURES EXPECTED THROUGH THIS EVENING.

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
THE TIMING OF COOLING WILL LKLY BE EVEN MORE IMPORTANT DURING THIS
PD AS FOCUS FOR SNFL SHIFTS EWD INTO CNTRL AND ERN PA. MODELS
GENERATE A ADDNL 0.50-1 INCH LIQUID EQUIVALENT OVR THIS AREA IN
THE 00-06Z TIMEFRAME...THE OPTIMUM WINDOW FOR SIG ACCUMS OVR
CNTRL AND ERN AREAS. WARM BL AND SFC TEMPS WILL EVENTUALLY BE
OVERCOME BY STG DYNAMIC COOLING AND ENHANCED PCPN/SNFL RATES ESP
IN COMMA HEAD/DEFORMATION ZONE NW OF SFC LOW TRACK...BUT
LIMITED/UNCERTAIN DURATION OF TEMPS COLD ENOUGH FOR SNOW WILL LKLY
RESULT IN COMPLICATED ELEVATION DEPENDENCE AND THUS LIMIT ACCUMS
TO SOME EXTENT IN VALLEY AREAS. THEREFORE ONLY UPGRADED TO WINTER
STORM WARNINGS FOR SOMERSET AND SCHUYLKILL WHERE PROBABILITIES
FOR HEAVY SNOW ARE GREATER OVR THE HIGHER TERRAIN OF THE LAURELS
AND POCONOS. ELSEWHERE AN ADVISORY SHOULD BE SUFFICIENT GIVEN THE
COMPLEX NATURE OF ACCUM DIFFS WITH ELEVATION AND UNCERTAINTY ASSOC
WITH TIMING CHANGEOVER/TRANSITION. FOLLOWING DAYS OF LOW
CONFIDENCE AND LARGE MDL SPREADS..THERE IS GOOD MODEL AGREEMENT ON
THE STORM TRACK AND THEREFORE USED A CONSENSUS APPROACH IN
CONSTRUCTING QPF/SNOW AMTS. FINALLY WITH THE THREAT OF 2+ INCH QPF
AND SATURATED GROUNDS ISSUED FLOOD WATCH IN COORDINATION WITH
LWX/PHI FOR A PTN OF THE LWR SUSQ VLY.

.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
COLD FRONT CONTINUES TO SLOWLY SAG THRU THE LOWER SUSQ VALLEY.

REGION CONTINUES TO BE AFFECTED BY WIDESPREAD IFR/MVFR. EXPECT
POOR FLYING CONDS TO CONTINUE THROUGH THE TAF PERIOD...WITH
PERIODS OF LIFR AND VLIFR CIGS/VSBYS POSSIBLE.

BY 12Z THURSDAY CONDITIONS WILL BE IMPROVING RAPIDLY WITH THE
STORM SYSTEM EXITING THE EAST COAST.

OUTLOOK...
WED...WIDESPREAD IFR/MVFR CONTINUING WITH A RAIN CHANGING TO SNOW
SCENARIO FROM WEST TO EAST THROUGHOUT THE DAY.

THU...NO SIG WX EXPECTED.

FRI...PM SHSN POSSIBLE NW MTNS.

SAT/SUN...NO SIG WX EXPECTED.

$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...CERU
AVIATION...CERU

AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

134 AM EST WED DEC 7 2011

.SYNOPSIS...
A WAVY FRONTAL BOUNDARY OVER CENTRAL PENNSYLVANIA WILL MOVE
SLOWLY TO THE SOUTH AND EAST OVERNIGHT. A DYNAMIC LOW PRESSURE
SYSTEM WILL DEVELOP IN THE LEE OF THE CENTRAL APPALACHIANS BY THIS
AFTERNOON AND INTENSIFY AS IT TRACKS NORTHEASTWARD OVER THE
DELMARVA PENINSULA...BEFORE ACCELERATING NORTHWARD ALONG THE NEW
ENGLAND COAST INTO THE CANADIAN MARITIMES BY THURSDAY MORNING.
RAIN WILL CHANGE TO SNOW FROM NORTHWEST TO SOUTHEAST BY THE
EVENING...AS COLD AIR WRAPS INTO THE BACKSIDE OF THE SYSTEM. SNOW
WILL END EARLY THURSDAY WITH SEASONABLY COLD AND MAINLY DRY
CONDITIONS PREVAILING INTO THE WEEKEND.

.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AT 06Z..SFC OBS AND RUC DATA SUGGEST WK WAVE OF LOW PRES IS BTWN
SEG AND RDG...WITH TRAILING WAVY FRONTAL BNDRY TRAILING TO THE SW
ALONG THE APPALACHIANS. AREAS OF DZ AND LGT RAIN WILL PERSIST IN
MOST AREAS PRIOR TO 08Z BEFORE RAIN SHIELD SURGING NEWD ACRS WV
OVERSPREADS THE SRN 1/2 TO 1/3 OF THE CWA. SATL ANAL AND TRENDS
SHOW THE MID-UPPER LOW TRACKING EWD ACRS ERN OK/NE TX/WRN AR
BEGINNING TO INTENSIFY AS IT PHASES WITH 150KT JET ACRS THE SE
U.S. WV LOOPS SHOWS THE UPPER TROUGH DIGGING TWD THE LWR TN VLY
WITH DOWNSTREAM IR ENHANCEMENT/COOLING CLOUD TOPS ALONG THE
S-CENTRAL APPALACHIANS FM TN TO WV WITH STRENGTHENING UPPER LVL
DIFL. RDR TRENDS APPEAR TO BE AHEAD OF NEAR TERM MDL GUID WHICH IS
NOT SURPRISING GIVEN THE PROGRESSIVE NATURE OF THIS SYS AND DEEP
WAA OUT AHEAD OF THE H5 TROUGH. RDR TRENDS ALSO SUGGEST THE QPF
AXIS MAY BE SETTING UP A LITTLE FURTHER N THAN DEPICTED BY THE
GUID. HOURLY TEMPERATURES HAVE FALLEN INTO THE UPPER 30S BEHIND
THE FRONT OVR THE LAUREL HIGHLANDS AND NW MTNS...BUT READINGS
SHOULD STAY ABV THE FZG MARK. HIGHEST POPS THROUGH 12Z ARE OVR
THE SRN TIER WITH 6-HR QPF AMTS LKLY IN THE 0.25 TO 0.50 INCH
RANGE PER MDL BLEND.

.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM THURSDAY/...
MODEL SOLUTIONS CONTINUE TO BE SIMILAR WITH TIMING...PLACEMENT
AND EFFECTS FOR WEDNESDAY AND WEDNESDAY NIGHT. CONFIDENCE IN THE SHORT
TERM FCST HAS INCREASED MARKEDLY IN THE LAST 12-18 HRS.

SHARP POS-TILTED TROUGH OVER THE CENTRAL STATES WILL SWING VERY
QUICKLY TO A MERIDIONAL OR EVEN SLIGHT NEG TILT BY WED EVENING. A
SFC LOW WILL DEVELOP IN THE CAROLINAS AS THE HEIGHT FALLS OCCUR
TONIGHT AND VERY EARLY WED. THE DEEP MOISTURE FLOW FROM THE GULF
GETS CUT OFF FAIRLY QUICKLY...BUT THE ATLANTIC WILL KEEP THE
PRESSURES DROPPING. LACK OF DEEP/ANOMALOUS EASTERLY FLOW IS A
NEGATIVE FOR THIS STORM...BUT THE DYNAMICS ARE VERY POWERFUL.
SW-NE UPPER JET IS WELL OVER 100KTS. THE FAST NORTHEASTWARD
MOVEMENT OF THE STORM WILL LIMIT THE TIME PERIOD OF HEAVIEST
PRECIP. HOWEVER...THE DYNAMICS PULL MUCHO MOISTURE IN AND TEMPS
COOL VERY RAPIDLY FROM TOP DOWN. THEREFORE...A CHANGE FROM RAIN TO
SNOW WILL OCCUR FROM TOP DOWN. SFC TEMPS ARE STILL RATHER WARM FOR
ACCUMS TO OCCUR IN THE LOWER ELEVS - ESP THE LOWER SUSQ - UNTIL
LATE IN THE DAY...THOUGH.

NAM/GFS BUFKIT PROFILES ARE EXTREMELY WET IN THE SERN HALF OF THE
AREA...WITH VERY STRONG UPWARD OMEGAS IN THE MID LEVELS...RIGHT IN
BEST THE DENDRITIC SNOW GROWTH ZONE. THE STORM SHOULD END RATHER
QUICKLY FROM W-SE WED NIGHT. QPF IN THE COLD AIR AND HPC MANUAL
PROGS GIVES HIGH PROB OF A 2-5 INCH SNOWFALL FOR THE SOUTHERN HALF
OF THE STATE...AND 6+ ARE POSSIBLE IN THE HIGHER ELEVATIONS OF THE
LAURELS WHERE TEMPS ARE COLDER FIRST AND OVER THE POCONOS/SCHUYLKILL
CO WHERE THE SNOW LEVELS DROP FIRST IN THE EAST AND THE PRECIP
WILL LAST INTO THE MIDDLE OF THE NIGHT. WILL POST A WINTER STORM
WATCH FOR SOMERSET AND SCHUYLKILL COS. AGAIN...THE DRAWBACKS FOR
HEAVIER SNOW IN THE MORE-POPULOUS AREAS OF THE MID AND LOWER SUSQ
VALLEY WILL BE THE LATER TURNOVER TO SNOW AND THE WARM SFC TEMPS.
SNOW MAY FALL FOR A WHILE BUT MELT AS IT FALLS WED AFTN. THIS MAY
SOUND FAMILIAR. THE S-L RATIOS LOOK LIKE A NEAR 10:1 WITH A HEAVY
WETNESS TO IT AS THE SNOW GRABS LOTS OF SUPER- COOLED WATER ON THE
WAY DOWN FROM ON HIGH.

THINK ADVISORY SNOWFALL IS POSSIBLE FOR A STRIPE FROM THE LAURELS
THROUGH DAUPHIN AND SCHUYLKILL COUNTIES LATE WEDNESDAY AFTERNOON
THROUGH LATE WEDNESDAY NIGHT. INTENSE UPWARD VERTICAL MOTION IN
ADVANCE OF THE VIGOROUS UPPER WAVE SHOULD BRING A 4 TO 6 HOUR
PERIOD OF HEAVY PRECIPITATION...LIKELY SNOW...TO NORTHERN PORTIONS
OF THE SOUTH CENTRAL MOUNTAINS AND THE MIDDLE TO LOWER SUSQ. RIVER
VALLEY. CONFIDENCE IS INCREASING AT THIS TIME...BUT NOT
SUFFICIENTLY TO SADDLE ONCOMING SHIFT WITH ADDITIONAL HEADLINES AT
THIS TIME WITH 00Z CYCLE HAVING JUST BEGUN.

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
POTENT BUT PROGRESSIVE LOW PRESSURE AREA FOR WED/WED NIGHT WILL
QUICKLY MOVE TO THE NEW ENGLAND COAST BY DAYBREAK THURS...WITH A
BRISK AND COLD WLY FLOW REGIME PREVAILING OVR CNTRL PA DURING THE
DAY. THIS SHOULD TRANSLATE INTO A BRIEF PD OF SNOW SHOWERS MAINLY
FOR THE NW MTNS EARLY GIVEN FAVORABLE DOWNWIND LAKE TRAJECTORIES
AND COLD CYC FLOW ALOFT. THE LLVL FLOW THU NIGHT INTO FRI BACKS
TO THE WSW AS A NRN STREAM TROUGH ROTATES INTO THE UPPER MIDWEST
AROUND THE BASE OF HUDSON BAY VORTEX.

A MSTR-STARVED COLD FNT MARKING THE LEADING EDGE OF THE UPPER
MIDWEST H5 TROUGH AND ACCOMPANYING SEASONABLY COLD /-12 TO -14C AT
850MB/ AIR ALOFT WILL CROSS THE AREA FRI NGT...WITH LITTLE
FANFARE OTHER THAN SOME LAKE ENHANCED/UPSLOPE SNOW SHOWERS ALONG
THE ALLEGHENIES. TEMPERATURES SHOULD BOTTOM ON SATURDAY AS THE CORE
UPPER TROUGH AXIS MOVES OVERHEAD...WITH MAXES IN THE UPPER 20S TO
MID 30S...ALONG WITH A BREEZY WESTERLY WIND. HIGH PRES WILL
OVERSPREAD THE REGION ON SUNDAY AND DOMINATE THE PATTERN INTO
EARLY NEXT WEEK. RETURN FLOW AROUND THE HIGH SHOULD LEAD TO
MODERATING TEMPS WITH FAIR WEATHER PERSISTING THROUGH MONDAY.

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
COLD FRONT CONTINUES TO SLOWLY SAG THRU THE LOWER SUSQ VALLEY.

REGION CONTINUES TO BE AFFECTED BY WIDESPREAD IFR/MVFR. EXPECT
POOR FLYING CONDS TO CONTINUE THROUGH THE TAF PERIOD...WITH
PERIODS OF LIFR AND VLIFR CIGS/VSBYS POSSIBLE.

BY 12Z THURSDAY CONDITIONS WILL BE IMPROVING RAPIDLY WITH THE
STORM SYSTEM EXITING THE EAST COAST.

OUTLOOK...
WED...WIDESPREAD IFR/MVFR CONTINUING WITH A RAIN CHANGING TO SNOW
SCENARIO FROM WEST TO EAST THROUGHOUT THE DAY.

THU...NO SIG WX EXPECTED.

FRI...PM SHSN POSSIBLE NW MTNS.

SAT/SUN...NO SIG WX EXPECTED.

.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS AFTERNOON THROUGH LATE TONIGHT
FOR PAZ058.
WINTER STORM WATCH FROM 10 AM EST THIS MORNING THROUGH THIS
EVENING FOR PAZ033.

$$
SYNOPSIS...DANGELO/STEINBUGL
NEAR TERM...DANGELO/DEVOIR/STEINBUGL
SHORT TERM...DANGELO/DEVOIR
LONG TERM...RXR/STEINBUGL
AVIATION...LA CORTE

AREA FORECAST DISCUSSION

NWS GREEN BAY WI

1034 PM CST TUE DEC 6 2011

UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE

.SYNOPSIS...SEASONABLY COLD AND VERY QUIET FOR THE EARLY PART OF
DECEMBER.

AMPLIFIED LNGWV PATTERN IN PLACE...WITH LARGE SCALE FLOW
DOMINATED BY MASSIVE RIDGE OVER THE ERN PAC. THE FLOW DOWNSTREAM
WAS SOMEWHAT SPLIT...WITH NRN STREAM MUCH STRONGER THAN THE
SRN...AND WITH TROFFING OVER ERN NOAM. THE TREND DURING THE FIRST
PART OF THE FCST PERIOD WL BE FOR BROAD ERN NOAM TROF TO EXPAND
SWD FM VORTEX IN THE HUDSON BAY RGN. THE SAME FEATURES SHOULD
REMAIN IN PLACE FOR THE LATTER HALF OF THE PERIOD...BUT WITH A
GRADUAL DECR IN AMPLITUDE.

TEMPS ACRS THE AREA HAVE COOLED TO NR NORMAL...AND WL CONT THE
DOWNSLIDE TO SOMEWHAT BLO NORMAL LEVELS AS THE UPR TROF DEEPENS
OVER THE RGN. ALTHOUGH THE N NOW HAS A DECENT SNOWCOVER...THE LACK
OF A WIDESPREAD DEEP SNOWCOVER ACRS THE ENTIRE REGION WL PREVENT
THIS FROM TURNING INTO A VERY COLD PERIOD. READINGS SHOULD REBOUND
DURING THE LATTER PART OF THE PERIOD AS UPR FLOW BECOMES MORE WLY.
GULF MOISTURE WL REMAIN TRAPPED WELL S OF THE AREA...AND DON/T SEE
ANY STG SYSTEMS IN THE FAST NWLY/WNWLY FLOW EITHER. EVEN THE
PROSPECT FOR LAKE-EFFECT LOOKS LOW AS FLOW WL BE RATHER WLY. SO
DON/T EXPECT MUCH PCPN DURING THE PERIOD.
&&

.SHORT TERM...TONIGHT AND WEDNESDAY.

LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM THE CENTRAL GREAT PLAINS...ACROSS THE
GREAT LAKES...AND INTO QUEBEC THIS AFTERNOON. DESPITE THE SURFACE
HIGH...LOW CLOUDS OVER WESTERN AND CENTRAL WISCONSIN ARE
STUBBORNLY MOVING TO THE NORTHEAST. EARLIER FLURRY ACTIVITY OVER
THE DOOR PENINSULA IS ALSO FINALLY STARTING TO MOVE TO THE EAST AS
WELL. MEANWHILE...OVER THE LAKE WINNIPEG REGION...A DIVING
SHORTWAVE IS SENDING A WARM FRONT TO THE SOUTHEAST. AS THE SURFACE
HIGH DRIFTS TO THE SOUTH TONIGHT...CLOUDS AND TEMPS REMAIN THE
MAIN FORECAST CONCERNS.

TONIGHT...SURFACE HIGH PRESSURE WILL DRIFT TO THE SOUTH AS HEIGHT
FALLS OCCUR OVER SOUTH-CENTRAL CANADA AND THE FAR NORTHERN PLAINS.
LOW LEVEL SW WINDS WILL STRENGTHEN AND CONTINUE TO PUSH THE LOW
STRATUS TO THE NE. BASED ON THE LATEST SATELLITE OBS...TEND TO
THINK THE LOW STRATUS WILL STAY IN TACT OVER CENTRAL INTO EAST-
CENTRAL WISCONSIN THROUGH MID-EVENING WHILE NORTH- CENTRAL
WISCONSIN MAY ACTUALLY TURN PARTLY CLOUDY. UNLESS SOME HOLES
DEVELOP LATER THIS AFTERNOON...WILL TREND THE FORECAST THIS
DIRECTION. DRIER AIR IS THEN PROGGED TO PUSH THE STUBBORN STRATUS
TO THE EAST LATE THIS EVENING AND OVERNIGHT. SOME HIGH CLOUDS MAY
ARRIVE LATE AHEAD OF A SHEAR SHORTWAVE DIVING OVER SOUTH-CENTRAL
CANADA. THE STRENGTHENING WIND FIELD AND CLOUD COVER WILL KEEP
TEMPS WARMER THAN LAST NIGHT...AND WILL GO UPPER SINGLE DIGITS
NORTH TO LOWER 20S SE.

WEDNESDAY...THE SHEARED WAVE WILL SLIDE SOUTHEAST OVER LAKE
SUPERIOR...AND PUSH A WEAKENING COLD FRONT ACROSS THE FORECAST
AREA DURING THE MORNING. WILL SEE SOME SCT TO BKN MID CLOUDS WITH
THE FRONT...BUT NO REAL THREAT OF SNOW SHOWERS EXCEPT OVER
NORTHERN VILAS WHERE WNW WINDS MAY SEND A SCT SNOW SHOWERS ALONG
THE U.P.-WISCONSIN BORDER. TEMPS A COUPLE DEGREES WARMER THAN
TODAY OFF OF A WARMER START IN THE MORNING.

.LONG TERM...WED NGT THROUGH NEXT TUE. TRENDED TEMPS DOWN A
LITTLE BOTH THU AND FRI AS FCST AREA WL BE DOMINATED BY COLD AIR
FLOWING SEWD FM CANADA. WLY FLOW SHOULD KEEP SIG LAKE-EFFECT NE OF
THE AREA. THE CANADIAN GLOBAL MODEL BROUGHT SOME PCPN ACRS E-C WI
ON THU NGT INTO FRI AS BAROCLINIC LEAF TYPE FEATURES SLIDES ACRS
THE AREA. THE FEATURE WAS ALSO AT LEAST HINTED AT ON THE REST OF
THE MODELS...BUT THEY WERE ALL WEAKER AND FARTHER S. SO CANADIAN
SEEMS LIKE AN OUTLIER AND WL STICK WITH DRY FCST.
&&

.AVIATION...CLOUDS CONTINUE TO BLANKET MUCH OF NORTHEAST WISCONSIN
LATE THIS EVENING. VFR CIGS WERE NOTED OVER EAST CENTRAL WISCONSIN
WHILE MVFR CIGS WERE OVER CENTRAL AND NORTH CENTRAL WISCONSIN. SAT
IMAGERY INDICATES THE BACK EDGE OF THE MVFR CIGS WITH SOME IFR
CIGS REMAINED FROM AROUND ASX TO SOUTHEAST MINNESOTA. INCREASING
SOUTHWEST WINDS MAY PRODUCE A FEW HOLES IN THE CLOUD COVER OVERNIGHT.
MORE VFR TO MVFR CLOUDS WITH A PASSAGE OF A COLD FRONT FOR
WEDNESDAY FOLLOWED WITH VFR CONDITIONS FOR WEDNESDAY NIGHT. WILL
REMOVE THE LLWS MENTION OVERNIGHT DUE TO GUSTY WINDS REPORTED OVER
WESTERN LOCATIONS LATE THIS EVENING.

TDH
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION

NWS DENVER CO

250 AM MST FRI DEC 9 2011

.SHORT TERM...DRY NW FLOW ALOFT WILL BE OVER THE AREA THRU TONIGHT.
HOWEVER WHAT APPEARS TO BE AN EASY FCST IS NOT DUE TO SHALLOW
INVERSIONS THAT WILL EXIST OVER LINGERING SNOWPACK ALONG THE FRONT
RANGE WHICH WILL AFFECT HIGH TEMPS. AREAS OF FOG AND LOW CLOUDS
HAVE DEVELOPED OVERNIGHT TO THE NORTH AND EAST OF DENVER WHICH WILL
LINGER THRU THE MORNING HOURS BEFORE BREAKING UP BY MIDDAY. BY AFTN
IT APPEARS A WK DENVER CYCLONE WILL BE IN PLACE NR DENVER WITH SLY
LOW LVL FLOW FM DENVER SOUTH ACROSS THE PALMER DIVIDE WHILE FM
DENVER NORTH TO GREELEY AND FORT COLLINS WINDS WILL BE LIGHT NNE.
HIGHS OVER THE SRN SUBURBS MAY REACH THE LOWER 40S WHILE ACROSS THE
NRN SUBURBS TO FORT COLLINS AND GREELEY READINGS MAY NOT GET OUT OF
THE 20S AS THE SHALLOW INVERSIONS HOLD SO A 20 DEGREE SPREAD IN
HIGHS ACROSS THE METRO AREA IS CERTAINLY NOT IMPOSSIBLE. OVER THE
PLAINS WILL KEEP READINGS MAINLY IN THE LOWER TO MID 30S.

.LONG TERM...HIGH PRESSURE ALOFT WILL SHIFT OVER COLORADO ON
SATURDAY WITH A DRY AND WARMER AIRMASS IN PLACE ACROSS COLORADO. FOR
SUNDAY...THE NEXT UPPER LOW WILL BE DEVELOPING ALONG THE WEST COAST
WHICH WILL SHIFT THE FLOW ALOFT TO A LIGHT SOUTHWESTERLY OVER
COLORADO. IN ADDITION...THERE WILL BE A DEVELOPING SURFACE LEE TROF
AIDING TO THE WARMUP ALONG THE FRONT RANGE. TEMPERATURES WILL CLIMB
TO A BIT ABOVE SEASONABLE NORMALS THROUGH THE WEEKEND. THIS WILL
TAKE A GOOD BITE OUT OF THE SNOW COVER OVER THE FRONT RANGE.

THE PATTERN EVOLUTION THROUGH MIDDLE OF NEXT WEEK IS SHOWING A BIT
BETTER CONSENSUS AMONGST THE LONG RANGE MODELS AS THE GFS HAS COME
MORE IN LINE WITH THE EUROPEAN...WITH A QUICKER EJECTION OF THE
DESERT SOUTHWEST LOW INTO COLORADO SOMETIME ON WEDNESDAY. THIS WILL
BRING A CHANCE OF SNOW TO THE MOUNTAINS AND COOLER TEMPERATURES. THE
PATTERN DOES NOT FAVOR THE PLAINS MUCH FOR PRECIP SO WILL SIT WITH
THE SLIGHT CHANCE CURRENTLY IN THE FORECAST.

.AVIATION...IFR CONDITIONS HAVE DEVELOPED JUST TO THE NORTH OF THE
AIRPORT WITH CAMS SHOWING FOG ALONG E-470 AND ALONG I-76. THE NAM
AND RUC KEEP THESE LOW CLOUDS AND FOG NORTH OF THE AIRPORT THRU THE
MORNING HOURS WHILE THE HRRR SHOWS IT AFFECTING THE AIRPORT THRU 15Z
WITH VISIBILITIES DROPPING DOWN TO 1/4 MILE. IF WK DENVER CYCLONE
STAYS TO THE NE OF DIA AND SFC WINDS BECOME LIGHT NWLY THEN THE LOW
CLOUDS AND FOG MAY MOVE INTO THE AIRPORT BY 11Z. CURRENT TAF HAS
A TEMPO GROUP WITH VISIBILITIES DROPPING DOWN TO 1 MILE AND CEILING
AROUND 500 FT SO MAY HAVE TO ADJUST LOWER AS CONDITIONS DVLP. AFT
15Z THE HRRR SHOWS WINDS BECOMING SLY AND THEN SELY BY MIDDAY. IF
THAT HAPPENS THEN LOW CLOUDS SHOULD GRADUALLY ERODE BY MID TO LATE
MORNING WITH IMPROVING CONDITIONS. FOR TONIGHT EXPECT VFR
CONDITIONS WITH WINDS BECOMING DRAINAGE BY 02Z.

.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SHORT TERM...RPK
LONG TERM....SWE
AVIATION...RPK

AREA FORECAST DISCUSSION

NWS CHARLESTON SC

421 AM EST FRI DEC 9 2011

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL TODAY. A COLD FRONT WILL MOVE THROUGH THE
REGION TONIGHT. HIGH PRESSURE WILL GENERALLY DOMINATE THROUGH THE
REMAINDER OF THE PERIOD.

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PRE-DAWN...PERIODS OF HIGH CLOUDS HAVE BEEN CROSSING GEORGIA AND THE
CAROLINAS OVERNIGHT AND AREAS OF STRATOCUMULUS RECENTLY DEVELOPING
OVER SE GEORGIA AND COASTAL SOUTHEAST SOUTH CAROLINA. A GOOD GRADIENT
OF TEMPS WITH A FEW AREAS AT OR JUST BELOW FREEZING OVER LOCALES
ADJACENT TO THE SE CSRA AND SE MIDLANDS REGIONS...40S CLOSER TO
THE COAST.

A BROAD SW-NE UPPER JET WILL RESIDE FROM THE GULF COAST STATES
TO THE MID ATLC TODAY WITH SURFACE HIGH PRES OVER THE REGION.
A MID LEVEL SHORT WAVE IS FORECAST TO RACE E ALONG THE UPPER GULF
COAST OUT OF TEXAS TODAY AND THIS SHOULD SLIGHTLY BACK OUR UPPER
FLOW LATE. MODELS HAVE BEEN IN AGREEMENT IN FORMATION OF A COASTAL
TROUGH TODAY AND EVEN A SURFACE WAVE DEVELOPING ALONG IT. THE MAIN
00Z MODEL DIFFERENCES ARE HIGHLIGHTED BY HOW FAR OFF THE COAST WEAK
CYCLOGENESIS OCCURS. THE NAM AND HRRR SUGGEST THE TROUGH AND WAVE
WILL NUDGE CLOSER TO THE COAST BUT BOTH MAY BE JUST A BIT TOO
AGGRESSIVE WITH PRECIP FIELDS GIVEN THE DRY GFS. IT APPEARS THAT
AFTER MID AFTERNOON ISOLATED LIGHT SHOWERS COULD INDEED OCCUR IN THE
CHARLESTON TRI-COUNTY AREA OR ALONG THE IMMEDIATE COAST FROM
CHARLESTON N. WE MAINTAINED SILENT POPS BUT DID INDICATE SOME
COASTAL SHOWERS ADJACENT TO CHARLESTON COUNTY LATE DAY.

ALL OTHER AREAS...MAINLY A SKY COVER AND TEMP FORECAST TODAY WITH
EXPANDING AREAS OF STRATOCUMULUS EXPECTED IN MANY PLACES BUT MODELS
NOT MUCH IN UNISON WITH CLOUD TRENDS EITHER TODAY. WE MAINTAINED
PERSISTENCE WITH A PARTLY TO MOSTLY CLOUDY FORECAST. MILDER WEATHER
WITH HIGHS IN THE LOWER TO MID 60S. THICKER MORE PERSISTENT CLOUD
COVER ANYWHERE WOULD RESULT IN SLIGHT LOWER TEMPS WITH A LIGHT NNE
WIND.

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
TONIGHT...CLOUDS SHOULD PREVAIL MOST AREAS DURING THE EVENING INTO
THE OVERNIGHT AS THE GULF COAST SHORT WAVE APPROACHES. A FEW EARLY
EVENING SPRINKLES ARE POSSIBLE IN THE CHARLESTON TRI-COUNTY AREA.
LATE TONIGHT...A FEW LIGHT SHOWERS MAY STREAK OVER OUR SOUTHEAST
GEORGIA ZONES IN ASSOCIATION WITH PVA AND SOMEWHAT HIGHER
CONDENSATION PRES DEFICITS THERE. WE INTRODUCED A 20 POP TO THE S OF
SAVANNAH LATE BUT DO NOT EXPECT MUCH IN WAY OF MEASURABLE RAIN.
CLOUDS WILL PROBABLY BE CLEARING INLAND LATE BUT THE BLANKETS OF
CLOUDS SHOULD MAKE FOR MILDER LOW TEMPS TONIGHT IN THE 40S MANY
AREAS. A SURFACE COLD FRONT WILL MOVE THROUGH THE AREA AFTER
MIDNIGHT AND LIGHT WINDS MAY BEGIN TO STIR A BIT TOWARD DAWN EVEN
OVER INLAND AREAS.

A BROAD UPPER LEVEL TROUGH PATTERN WILL FAVOR SURFACE HIGH PRESSURE
BUILDING NORTH OF THE REGION WITH A PERSISTENT COASTAL TROUGH ALONG
THE SC/GA COASTLINE. MOISTURE CONVERGENCE OVER THE WATERS AND ALONG
THE COAST WILL SUPPORT SCATTERED SHOWERS FROM TIME TO TIME.
ELSEWHERE...DRY CONDITIONS EXPECTED WITH TEMPERATURES DROPPING BELOW
NORMAL SATURDAY NIGHT THROUGH MONDAY BEHIND A REINFORCING COLD
FRONT.

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
A RELATIVELY ZONAL FLOW WILL GIVE WAY TO A BUILDING UPPER RIDGE MID
TO LATE NEXT WEEK. A COLD FRONT COULD APPROACH FROM THE WEST ON
FRIDAY. TEMPERATURES WILL SLOWLY WARM TO ABOVE-NORMAL VALUES BY LATE
IN THE PERIOD WITH GENERALLY DRY CONDITIONS.

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING AT BOTH KCHS AND
KSAV. THEN...STRATOCUMULUS POSITIONED OFF THE COAST COULD BEGIN TO
ADVECT INLAND LATE TONIGHT AND FRIDAY AS THE LOW LEVEL FLOW VEERS
ONSHORE. WHILE CEILINGS ARE EXPECTED TO DEVELOP AT BOTH TERMINALS...
MODELS SUGGEST THEY SHOULD GENERALLY REMAIN VFR. THERE IS A SMALL
POTENTIAL FOR SOME MARGINAL MVFR CEILINGS TO DEVELOP FROM DAYBREAK
THROUGH LATE MORNING...BUT GIVEN THE LOW PROBABILITY WILL ONLY
SHOW THIS CLOUD LAYER AS SCATTERED. MODEL SOUNDINGS SHOW CIGS MAINLY
4-6 KFT BY THIS AFTERNOON AND EVENING. LIGHT WINDS THROUGHOUT WITH
A N TO NE COMPONENT.

EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED TO PREVAIL.

.MARINE...
STRONG THERMAL AND MOISTURE GRADIENTS HAVE ELEVATED NE WINDS TO A
SOLID 15 KT OVERNIGHT. SEAS HAVE BEEN BUILDING A BIT AT GRAYS
REEF AND WERE BETWEEN 4-5 FT PRE-DAWN. WINDS SHOULD BACK A BIT
TODAY WITH DIMINISHING SPEEDS AND SEAS REMAINING 2-4 FT. 5 FT
SEAS WELL OFF THE GEORGIA COAST EARLY TODAY. A COLD FRONT WILL
MOVE THROUGH THE WATERS AFTER MIDNIGHT TONIGHT AND N WINDS SHOULD
BEGIN TO SHOW A LATE NIGHT UPTICK...NEARING 15 KT BY DAWN WITH
SEAS BUILDING BY A FOOT OR SO TOWARD DAYBREAK ON SAT TO THE S OF
CHARLESTON.

STRONG HIGH PRESSURE BUILDING IN FROM THE NORTHWEST SATURDAY
AND SUNDAY. A CORRESPONDING INCREASE IN WINDS/SEAS EXPECTED AS
THE NORTHEAST GRADIENT TIGHTENS. SMALL CRAFT ADVISORY CONDITIONS
LIKELY ALL WATERS...EXCEPT PERHAPS CHARLESTON HARBOR...SUNDAY INTO
MONDAY. THERE IS EVEN A CHANCE THAT GALE CONDITIONS COULD OCCUR
LATE SATURDAY NIGHT INTO SUNDAY OVER PORTIONS OF THE AREA.
CONDITIONS WILL IMPROVE LATE MONDAY INTO TUESDAY AS THE HIGH
PRESSURE TO THE NORTH WEAKENS AND SHIFTS EAST.

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

JRL

AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

305 AM CST FRI DEC 9 2011

.DISCUSSION...
910 PM CST

MTF

//PREV DISCUSSION...
338 PM CST

RODRIGUEZ

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 08Z...

* LGT SN CONTINUES THRU 10Z. VSBYS WILL FLUCTUATE BETWEEN
2-3SM...AND CIGS BETWEEN 2KFT AND 3KFT AGL.

* SN WILL PUSH EAST AND END BEFORE DAYBREAK WITH A RETURN TO VFR
CONDS.

BEACHLER

//DISCUSSION...UPDATED 06Z...

LEAD SHORT WAVE TROUGH CURRENTLY OVER THE MS VALLEY CONTINUED TO
MOVE EASTWARD. A SECOND SHORT WAVE TROUGH HAS CONTINUED TO ROTATE
SOUTHEASTWARD FROM OVER THE EASTERN DAKOTAS TO WESTERN MN AND
NORTHWEST IA. THE INITIAL SHORT WAVE HAS BEEN GRADUALLY SPREADING
SNOW EASTWARD ACROSS THE SOUTH HALF OF IA INTO PORTIONS OF FAR
NORTHWEST IL...AND A MIX OF RAIN AND SNOW INTO WEST CENTRAL IL
DURING THE EVENING.

WHILE RADAR ECHOES COVER MUCH OF NORTHERN AND CENTRAL IL ALMOST
ALL OF THE PRECIPITATION IS EVAPORATING BEFORE REACHING THE
GROUND AS QUITE DRY LOW LEVEL AIR IN PLACE WITH SURFACE DEW POINT
DEPRESSIONS 18 TO 20 DEGREES F JUST NORTH OF THE WI BORDER. UNDER
THE FEW STRONGER BANDS LIGHT SNOW HAS MADE IT TO THE GROUND WITH
IT BEING REPORTED FROM THE QUAD CITIES AND KC75 TO AS FAR NORTH
AS KSFY.

WITH THE FIRST SHORT WAVE CONTINUING ACROSS SOUTHERN WI AND
NORTHERN AND CENTRAL IL OVERNIGHT SOME LIGHT SNOW IS EXPECTED TO
MOVE ACROSS NORTHEAST IL. WITH ONLY VERY LIGHT INTENSITY AND
SHORT DURATION OF OCCURRENCE EXPECT KORD AND KMDW TO ONLY RECEIVE
A TOTAL OF A TRACE TO 0.1 INCH OF SNOWFALL. AS THIS SHORT WAVE
TROUGH PASSES OVERHEAD AND TO THE EAST LOW LEVEL WINDS BECOME
WEST-NORTHWEST AND ADVECT THE VERY DRY AIR ACROSS MN...WI AND
NORTHEAST IA ACROSS NORTHERN IL.

THE SECOND SHORT WAVE TROUGH IS PROGGED TO MOVE TO A POSITION
FROM NORTHEAST WI SOUTHWEST ACROSS IA AT 18Z. THIS WILL CONTINUE
TO PRODUCE LIGHT PRECIPITATION ACROSS CENTRAL IL TO NORTHERN
IND DURING THE EARLY AND MID MORNING BUT DUE TO INTRUSION OF
INCREASINGLY DRY LOW LEVEL AIR THE PRECIPITATION IS EXPECTED TO
REMAIN SOUTH OF THE LOCAL TERMINALS. WITH PASSAGE OF SECOND SHORT
WAVE TROUGH DURING THE DAY FRI SKIES WILL CLEAR.

SURFACE WINDS ONLY TO BACK AND VEER 20 DEG OR SO AS EACH SHORT
WAVE TROUGH PASSES BY.

TRS

//ORD AND MDW CONFIDENCE...UPDATED 08Z...

* HIGH CONFIDENCE IN WIND DIR/SPEED.
* MEDIUM CONFIDENCE IN CIGS/VSBY PRIOR TO 13Z.
* HIGH CONFIDENCE IN CIGS/VSBY AFT 13Z.

BEACHLER

//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...

SATURDAY...VFR.

SUNDAY...VFR.

MONDAY...VFR.

TUESDAY...VFR.

WEDNESDAY...VFR. CHC SHRA DURING NIGHT.

TRS

.MARINE...
305 AM CST

LOW PRESSURE OVER HUDSON BAY WILL BEGIN TO LIFT NORTHEASTWARD
TODAY. HOWEVER...WEST TO NORTHWEST FLOW BEHIND THE LOW WILL
CONTINUE TO STREAM COLD AIR OUT OF CANADA AND ACROSS THE GREAT
LAKES. THE VERY COLD AIR MOVING OVER RELATIVELY WARMER WATER WILL
BRING A CHANCE FOR WATERSPOUTS OVER THE LAKE TODAY AND TONIGHT.
HIGH PRESSURE OVER THE NORTHERN AND CENTRAL PLAINS WILL SPREAD
ACROSS THE MIDDLE MISSISSIPPI AND OHIO VALLEYS TONIGHT AND
TOMORROW. AS A LOW PRESSURE SYSTEM DROPS OUT OF THE CANADIAN
ROCKIES SATURDAY...WINDS OVER THE LAKE WILL TURN MORE
SOUTHWESTERLY AND AS THE LOW TRACKS ACROSS SOUTHERN CANADA WHILE
HIGH PRESSURE SETTLE SOUTH OF THE LAKES ON SUNDAY...SOUTHWEST
WINDS MAY INCREASE TO GALE FORCE.

KREIN

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN CITY IN UNTIL 10 AM SATURDAY.

AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

210 AM CST FRI DEC 9 2011

.DISCUSSION...
910 PM CST

MTF

//PREV DISCUSSION...
338 PM CST

RODRIGUEZ

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 08Z...

* LGT SN CONTINUES THRU 10Z. VSBYS WILL FLUCTUATE BETWEEN
2-3SM...AND CIGS BETWEEN 2KFT AND 3KFT AGL.

* SN WILL PUSH EAST AND END BEFORE DAYBREAK WITH A RETURN TO VFR
CONDS.

BEACHLER

//DISCUSSION...UPDATED 06Z...

SURFACE WINDS ONLY TO BACK AND VEER 20 DEG OR SO AS EACH SHORT
WAVE TROUGH PASSES BY.

TRS

//ORD AND MDW CONFIDENCE...UPDATED 08Z...

* HIGH CONFIDENCE IN WIND DIR/SPEED.
* MEDIUM CONFIDENCE IN CIGS/VSBY PRIOR TO 13Z.
* HIGH CONFIDENCE IN CIGS/VSBY AFT 13Z.

BEACHLER

//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...

SATURDAY...VFR.

SUNDAY...VFR.

MONDAY...VFR.

TUESDAY...VFR.

WEDNESDAY...VFR. CHC SHRA DURING NIGHT.

TRS

.MARINE...
138 PM CST

KJB

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN CITY IN UNTIL 10 AM SATURDAY.

AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

1100 PM CST THU DEC 8 2011

.DISCUSSION...
910 PM CST

MTF

//PREV DISCUSSION...
338 PM CST

RODRIGUEZ

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

*THREAT OF SHORT PERIOD OF LIGHT SNOW OVERNIGHT-PREDAWN.

TRS

//DISCUSSION...UPDATED 06Z...

SURFACE WINDS ONLY TO BACK AND VEER 20 DEG OR SO AS EACH SHORT
WAVE TROUGH PASSES BY.

TRS

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

*HIGH CONFIDENCE IN WIND AND CLOUD FORECASTS.

*MODERATE CONFIDENCE IN THE COUPLE HOUR WINDOW WHEN LIGHT SNOW
MAY OCCUR.

TRS

//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...

*
SATURDAY...VFR.

SUNDAY...VFR.

MONDAY...VFR.

TUESDAY...VFR.

WEDNESDAY...VFR. CHC SHRA DURING NIGHT.
*

TRS

.MARINE...
138 PM CST

KJB

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN CITY IN UNTIL 10 AM SATURDAY.

AREA FORECAST DISCUSSION...UPDATED

NWS INDIANAPOLIS IN

1117 PM EST THU DEC 8 2011

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

0 AND 1Z RUC ARE KEEPING ALL PRECIPITATION WEST AND THEN NORTH OF
THE FORECAST AREA...AND THE LATEST RUN IS SHOWING LESS ISENTROPIC
LIFT AVAILABLE THAN EARLIER RUNS. ALL OF THE CURRENT SNOW THAT IS
FALLING IN NEBRASKA...IOWA AND WESTERN ILLINOIS APPEARS TO BE
ASSOCIATED WITH UPPER FORCING AND IS BEHIND THE FRONT. HOWEVER THE
RAPID REFRESH SHOWS THE SNOW IN THE WESTERN ILLINOIS BAND EXPANDING
AND PRODUCING MEASURABLE SNOW ACROSS THE NORTHERN COUNTIES BY AROUND
6 OR 7Z...WHICH LOOKS MUCH MORE LIKE THE 0Z NAM.

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

MAIN FOCUS DURING THIS PERIOD WILL BE ENDING ANY SNOWFALL ON
FRIDAY AND THEN FOCUS WILL BE TEMPERATURES.

.LONG TERM /MONDAY THROUGH THURSDAY/...

.AVIATION /DISCUSSION FOR THE 090600Z TAFS/...

EXPECT CEILINGS AND VISIBILITIES TO DETERIORATE TO MVFR OR POSSIBLY
IFR IN LIGHT SNOW AT LAF AROUND ISSUANCE TIME AS AN UPPER TROUGH
APPROACHES FROM THE NORTHWEST. MEANWHILE...IND AND HUF SHOULD BE AT
THE EDGE OF ANY LIGHT SNOW FIELD...SO WILL GO WITH ONLY MVFR
CONDITIONS IN THE FLURRIES THERE OVERNIGHT ENDING MID MORNING. BMG
SHOULD JUST SEE VFR THROUGH THE PERIOD AS DEEPER MOISTURE STAYS TO
THE NORTH. MEANWHILE...COLD FRONT JUST NORTH OF LAF AT 04Z EXPECTED
TO MOVE TO NEAR HUF AND IND AROUND 07Z OVERNIGHT AND 09Z AT BMG.
WINDS WILL BE LIGHT FROM THE SOUTHWEST AHEAD OF THE FRONT AND SHIFT
TO THE NORTHWEST BEHIND IT INCREASING TO AROUND 10 KNOTS AFTER 18Z
THIS AFTERNOON AS ALL SITES IMPROVE TO VFR.

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SYNOPSIS...PUMA
NEAR TERM...CP
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...MK

AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

330 AM CST FRI DEC 9 2011

.SYNOPSIS...
AREA RADARS AT 08Z INDICATED A BAND OF LIGHT SNOW EXTENDING ROUGHLY
FROM FAIRFIELD THROUGH THE QUAD CITIES TO STERLING. THIS WAS
ASSOCIATED WITH AN AXIS OF FRONTOGENESIS NORTH OF THE COLD FRONT
THAT HAS SETTLED WELL SOUTH OF THE AREA. BASED ON RADAR TRENDS AND
RECENT SNOWFALL MEASUREMENT OF .7 INCHES HERE AT DVN...IT APPEARS
THAT A WIDESPREAD .5 TO 1 INCH SNOWFALL EVENT HAS OCCURRED FOR
ROUGHLY THE AREA SOUTH OF INTERSTATE 80. THE FRONTOGENESIS WAS BEING
TRIGGERED BY BOTH A MID LEVEL IMPULSE ROUNDING THE BASE OF A
LONGWAVE TROUGH OVER NORTH CENTRAL U.S...AND THE ENTRANCE REGION TO
A 150 KT JET CORE EXITING TO THE NORTHEAST OUT OF THE GREAT LAKES
INTO EASTERN CANADA. AT THE SURFACE...THE COLD FRONT REACHED FROM
CENTRAL OK NORTHEAST THROUGH SOUTHERN MO TO SE LOWER MI. TO THE
NORTH...A RIDGE EXTENDED FROM A 1030 MB HIGH OVER EASTERN MT
SOUTHEAST ACROSS NEB INTO KS. UNDER THIS RIDGE...TEMPERATURES WERE
IN THE SINGLE DIGITS AND TEENS...WITH A FEW SUBZERO READINGS
DIRECTLY UNDER THE HIGH CENTER IN AREAS WITH DEEPER SNOWCOVER.

.SHORT TERM...TODAY AND TONIGHT...
INITIAL FOCUS IS THE SNOW ENDING THIS MORNING...THEN TEMPERATURES AS
STRONG HIGH PRESSURE BUILDS AN ARCTIC AIRMASS INTO THE AREA BY
TONIGHT. LATEST RADAR TRENDS HAVE SHOWN A GENERAL WEAKENING TREND IN
THE SE TO NE BAND OF SNOW AS HAS TRANSITIONED E-SE OVER THE PAST
COUPLE HOURS. THIS ALIGNS WELL WITH THE RUC MODEL TRENDS INDICATING
RAPIDLY WEAKENING FRONTOGENESIS BETWEEN 06Z AND 12Z AS THE PRIMARY
MID AND UPPER LEVEL FORCING EXITS THE AREA. THIS...ALONG WITH AWIPS
DISTANCE-TIME TOOL SUGGESTS THE AXIS OF ACCUMULATING WILL LIKELY BE
OVER BY 12Z OVER THE AREA WITH FLURRIES FOR AN HOUR OR TWO TO FOLLOW
SOUTHEAST OF A KEOKUK TO GALESBURG LINE. LATEST MODELS SUGGEST A
SECOND WEAK VORT MAX AND AXIS OF MID LEVEL QG FORCING DROPPING
SOUTHEAST OUT OF SD INTO S CENTRAL IA BY 18Z. THIS WILL LIKELY BE
ENOUGH TO KEEP CLOUDS IN PLACE ACROSS THE SOUTH...BUT WITH A DEEP
DRY LOW LAYER IN PLACE BY THIS TIME...WILL MENTION ONLY FLURRIES FOR
ROUGHLY SOUTH OF HIGHWAY 34 THIS MORNING. TO THE NORTH...SKIES
SHOULD CLEAR BY MID MORNING...BUT WITH THE COMBINATION OF COLD
ADVECTION...REINFORCED BY FRESH SNOWFALL...DO NOT EXPECT MUCH
TEMPERATURE RECOVERY AND HAVE HELD HIGHS IN THE 20S.

TONIGHT...A 1035 PLUS HIGH CENTER SETTLES INTO MO WITH THE RIDGE
AXIS REACHING NORTH ALONG THE MS RIVER BY 12Z. THIS...ALONG WITH
UPPER LEVEL SUBSIDENCE...A COLUMN OF DRY AIR...AND FRESH ALBEIT
SHALLOW SNOW COVER...SHOULD LEAD TO A BITTER COLD NIGHT. USING A
COMBINATION OF FORECAST 850 MB TEMPERATURES...AND UPSTREAM TRENDS
FROM TONIGHT...HAVE STAYED WITH PREVIOUS FORECAST MINS FROM THE
SINGLE DIGITS ACROSS THE CENTRAL AND NORTHERN 2/3RDS OF THE FORECAST
AREA...TO AROUND 10 IN THE FAR SOUTH. LATER SHIFTS MAY BE ABLE TO
FINE TUNE THIS ONCE THE EXTENT AND COVERAGE OF TONIGHT/S SNOWFALL
CAN BE ASSESSED AND TAKE INTO ACCOUNT. ..SHEETS..

.LONG TERM...SATURDAY THROUGH NEXT THURSDAY...
DRY WITH MODERATING TEMPERATURES INTO THURSDAY...A MODERATE RAIN
EVENT LIKELY LATE WEDNESDAY INTO THURSDAY.

OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH DRY UPSTREAM
RIDGING SUPPORTING LITTLE SENSIBLE IMPACTS UNTIL NEXT THURSDAY. THE
DAY 7 SYSTEM/S ENERGY IS IN THE WESTERN PACIFIC WITH LITTLE PROBLEMS
NOTED THAT WOULD GREATLY IMPACT RAIN EVENT LATE WEDNESDAY INTO NEXT
THURSDAY. PREFERENCE FOR DAY 7 EVENT IS CLOSER TO HI-RES ECMWF AS GFS
APPEARS TOO MOIST AND THUS PRODUCING TOO HIGH PRECIPITATION AMOUNTS.
TOOLS AND TECHNIQUES SUGGEST MOSTLY .25 TO .75 INCH AMOUNTS FOR THE
AREA. THESE AMOUNTS SHOULD BE BETTER ASCERTAINED NEXT 24-48 HOURS.

SATURDAY-SUNDAY...SURFACE AND UPPER LEVEL RIDGING SUPPORTS FAIR SKIES
AND COLD WITH WIDE DIURNAL TEMPERATURE RANGES WITH MINS ON LOW SIDE
AND MAX TEMPS ON THE HIGHER SIDE. TEMPERATURES MODERATING TO ABOVE
NORMAL BY SUNDAY NIGHT WITH SOUTH WINDS AS HIGH PRESSURE MOVES EAST.

MONDAY-MONDAY NIGHT...LOW LEVEL MOISTURE RETURN AHEAD OF NEXT WEAK
AND DECAYING FRONT APPEARS MAY BE A BIT OVERDONE. HAVE LEFT SLIGHT
CHANCE POPS OF A MIX OR MOSTLY LIGHT SNOW BUT LATER SHIFTS MAY BE
ABLE TO REMOVE POPS IF TOO MOIST BIAS IS CONFIRMED. HIGHS MAY REACH
40 DEGREES CERTAIN AREAS WITH ENOUGH SUNSHINE FOR LATER SHIFTS TO
CONSIDER.

TUESDAY-WEDNESDAY...SLOW WARMING TREND CONTINUES AS SW CONUS UPPER
LOW STARTS TO MOVE INTO PLAINS WITH MODERATE WAA ON SOUTH WINDS
IMPACTING AREA BY MID/LATE WEDNESDAY PM. MOSTLY FAIR SKIES TO GIVE
WAY TO LOTS OF MID/HI CLOUDS BY WEDNESDAY AFTERNOON. TEMPERATURES TO
AVERAGE ABOUT 10 DEGREES ABOVE NORMAL WITH LIGHT WESTERLY WINDS TO
BECOME MODERATE SOUTH WINDS AS DISTURBANCE APPROACHES. ALL IN ALL...
REASONABLY NICE WEATHER FOR MID DECEMBER. HIGHS MAY REACH INTO THE
MIDDLE 40S FAVORED SOUTHERN LOCATIONS IF ENOUGH SUNSHINE AND BL
MIXING OCCURS WEDNESDAY PM. PRECIPITATION TO OVERSPREAD AREA LATE PM
AND ESPECIALLY WEDNESDAY NIGHT WITH GOOD WAA AS DISTURBANCE ROTATES
NE WITH SURFACE LOW PASSING TO OUR NW. SPEED OF SYSTEM AND SHEARING
FROM OPENING OF CLOSED SOUTH PLAINS UPPER LOW SUGGESTS 3-6 HOURS OF
LIGHT TO MODERATE RAIN. MOST AREA RAIN AMOUNTS ARE LIKELY TO TOTAL
.25-.50 INCHES WITH LOCALIZED .75+ INCH AMOUNTS POSSIBLE NEAR TRIPLE
POINT AND ANY POTENTIAL DEFORMATION ZONE.

THURSDAY...UPPER LOW/S SLOWER PROGRESS SUGGESTS ANOTHER SEASONABLY
MILD DAY WITH RAIN ENDING BY MID DAY WITH LIMITED COOLING BEHIND
FRONT AS UPPER TROUGH STAYS TO THE WEST. TRENDS SUGGEST THIS UPPER
DISTURBANCE WILL CONTINUE TO SLOW AND PHASE WITH FURTHER NW TRACK
NEXT 48 HOURS. ..NICHOLS..

.AVIATION...
AN UPPER LEVEL DISTURBANCE PRODUCING A BAND OF SNOW FROM SOUTHEAST
IOWA INTO NORTHWEST ILLINOIS WILL SLIDE SOUTHEAST OF THE REGION BY
SUNRISE. IFR CONDITIONS AT MLI AND BRL WILL IMPROVE TO VFR BY 13Z.
CONDITIONS WILL REMAIN VFR WITH CLEARING SKIES THROUGH THE REST OF
TODAY AND TONIGHT AS HIGH PRESSURE MOVES INTO THE REGION. ..SHEETS..

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

SHEETS/NICHOLS

AREA FORECAST DISCUSSION

NWS GOODLAND KS

249 AM MST FRI DEC 9 2011

.DISCUSSION...
249 AM MST FRI DEC 9 2011

FORECAST PROBLEMS WILL EXTENT OF FOG THIS MORNING AND POSSIBLY
SATURDAY MORNING...TEMPERATURE FORECAST INTO THE WEEKEND WHICH WILL
NOT BE EASY BASED ON RECENT HORRIBLE PERFORMANCE...AND STORM FOR THE
MIDDLE OF NEXT WEEK. SATELLITE CONTINUING TO SHOW AN AMPLIFIED FLOW
FROM THE PACIFIC INTO EASTERN NORTH AMERICA. TROUGHS OVER THE
WESTERN PACIFIC AND OVER NORTH AMERICA HAVE BEEN DEEPENING OVER THE
LAST 24 HOURS.

AT JET LEVEL MODELS WERE TOO FAR SOUTH AND EAST WITH THE JET AXIS
PUSHING THROUGH WESTERN MONTANA. THE NAM WAS DOING A LITTLE BETTER
THAN THE OTHER MODELS. ALL THE MODELS WERE DOING FINE AT MID
LEVELS. THE ECMWF WAS DOING A LITTLE BETTER THAN THE NAM WITH THE
SURFACE PRESSURE AND WIND FIELD. IT WAS CAPTURE THE TROUGHING ALONG
THE FRONT RANGE WELL PLUS IT WAS DOING BETTER WITH THE SURFACE
RIDGING FROM THE CENTRAL PLAINS EXTENDING TO THE NORTHWEST. MAKES
SENSE WITH WERE THE JET IS AS WELL. ON THE LOW LEVEL THERMAL FIELD
THE GFS WAS DOING SLIGHTLY BETTER THAN THE CANADIAN AND ECMWF.
BOIVER WOULD SUPPORT FOR THIS WEEK AS WELL.

TODAY/TONIGHT...LEFT FRONT QUADRANT OF STRONG NORTH TO SOUTH JET
WILL MOVE ACROSS THE AREA FROM AROUND 18Z THROUGH THE AFTERNOON.
SATELLITE IS SHOWING A THICKENING/SOUTHWARD MOVING MID DECK AND IT
APPEARS TO BE TIED TO THE MID/UPPER JET. SO THERE LOOKS TO BE SOME
MID CLOUDS ON TOP OF WHATEVER STRATUS WE HAVE AROUND AS WELL. WILL BE
MONITORING TRENDS AS LONG AS POSSIBLE BUT SOME COVERAGE OF FREEZING
FOG WILL BE NEEDED AT LEAST THROUGH MID MORNING.

THEN HOW FAST CLOUDS CLEAR OUT WILL BE A BIG DETERMINER ON HOW WARM
IT WILL GET. TEMPERATURE FORECAST WILL ALSO BE COMPLICATED BY THE
REMAINING SNOWFIELD WHICH WAS HARD TO MONITOR DUE TO CLOUD COVER.
BUT DUE TEMPERATURES BEING 5 TO 10 DEGREES WARMER THAN ADVERTISED
YESTERDAY...THERE WAS SOME MELTING. THERE IS A CENTRAL CORRIDOR
FROM SOUTHWEST TO NORTHWEST...ROUGHLY FROM GOODLAND TO MCCOOK AND
OBERLIN WHERE THE DEEPEST SNOW COVER RESIDES. ON EITHER SIDE OF
THIS LITTLE TO NO SNOW IS IN PLACE. WITH THE DWINDLING SNOW COVER
AND LAST FEW DAYS PERFORMANCE...THE NAM IS BEING OVERLY AFFECTED BY
THE SNOW IT STILL THINKS IS ON THE GROUND. MAV/GFS 2 METER HAS BEEN
A LITTLE BETTER BUT STILL HAS SHOWN A COOL BIAS.

LATEST SATELLITE SHOWS THE STRATUS FIELD EXPANDING SOUTH RAPIDLY AND
NOT AS FAST ON THE WEST END. THE RUC IS CAPTURING THE STRATUS FIELD
THE BEST WITH THE GFS NOT TOO FAR BEHIND. SAYING THIS...THESE WOULD
INDICATE THAT THE SOUTHEAST THIRD TO HALF MAY KEEP SOME KIND OF LOW
CLOUD COVER THE REST OF THE DAY. ALSO THE WIND FIELD LOOKS TO BE
BLOWING FROM THE SNOWFIELD TO THE SOUTHEAST. ALL THAT SAID MAY LOWER
MAXES A LITTLE BIT WITH THE THINKING THAT THE SOUTHEAST WILL BE THE
COOLEST.

THE 00Z NAM IS PRODUCING A WIDE AREA OF NOT ONLY FOG BUT DENSE FOG BY
LATER TONIGHT. THE 06Z NAM HAS MOVED THIS AREA FURTHER NORTH.
COMPARED TO OTHER MODEL OUTPUT IT IS BY FAR THE MOST AGGRESSIVE.
CONSIDERING THOUGH THAT THE RUC AND GFS ARE SLOW IN REMOVING MORNING
STRATUS...THE RICHER LOW LEVEL MOISTURE MAY NOT BE THAT FAR AWAY.
THERE WILL BE LIGHT WINDS AND PROBABLY LITTLE TO NO CLOUD COVER TO
PREVENT RADIATIONAL COOLING TO CONTINUE. ALSO CONSIDERING THE LIGHT
WIND FIELD...THE AIR MASS WILL NOT CHANGE THAT MUCH. CONSIDERING HOW
THE WIND AND SNOW FIELD IS...WHAT THE NAM IS SHOWING NOT OUT OF THE
REALM OF POSSIBILITY SO INSERTED FOG INTO THE FORECAST FOR TONIGHT.

SATURDAY/SATURDAY NIGHT...AFTER THE MORNING STRATUS AND FOG BURN OFF
SHOULD BE A LOT OF SUN. LIGHT DOWNSLOPE WINDS TRANSITION TO A MORE
SOUTHERLY DIRECTION. CONSIDERING THAT NOT MUCH MELTING WILL OCCUR
TODAY LOCATIONS ALONG AND NORTH OF THE SNOWFIELD MAY HAVE A HARD
TIME WARMING UP A LOT. THERE CONTINUES TO BE A HUGE DIFFERENCE IN
HIGH TEMPERATURE FOR THIS DAY. AT THIS TIME WILL KEEP TEMPERATURES
NEAR THE MAV/GFS 2 METER/ECMWF WHICH SEEM TO HAVE BEEN WORKING THE
BEST.

LOW LEVEL JET/WARM AIR ADVECTION LOOK TO START PICKING UP DURING THE
NIGHT. THIS SHOULD TRANSPORT MOISTURE BACK NORTH. NOT SOLD ON ANY
FOG BUT MORE THAN ONE MODEL WOULD INDICATE STRATUS TO MOVE BACK INTO
THE SOUTHEAST HALF. SO WILL MAKE THAT AREA WARMER.

SUNDAY/SUNDAY NIGHT...LEFT FRONT QUADRANT OF NEW SOUTHERN JET
APPROACHES THE SOUTHWEST PORTION OF THE FORECAST AREA LATE IN THE
DAY. SOME JET LIFT WILL BE NEAR THE SOUTHERN PORTION OF THE AREA
DURING THE NIGHT. IT IS POSSIBLE THAT SOME STRATUS WILL OUT IN THE
EAST MOST OF THE MORNING AT THE VERY LEAST. WINDS WILL TEND TO BE
SOUTH TO SOUTH SOUTHEAST. THAT LOOKS REASONABLE CONSIDERING THE
SOUTHWEST FLOW ALOFT. IN FACT THE WINDS MAY BE ENOUGH SOUTHEAST.
CONTINUED HUGE DIFFERENCES IN MODEL OUTPUT. NO MATTER WHICH OUTPUT
YOU CONSIDERING...THEY ALL SHOW A COOLING TREND FROM SATURDAY TO
SUNDAY WHICH IS A LITTLE DISTURBING. AGAIN WILL PLAY IT
CONSERVATIVE AND KEEP TEMPERATURES SIMILAR AND NOT RAISE THEM MUCH
IF ANY.

AGAIN FOR SUNDAY NIGHT WITH THE STRONG SOUTHERLY LOW LEVEL FLOW...
STRATUS AND POSSIBLY SOME FOG WILL SURGE BACK INTO THE AREA.

THANKS TO ALL THAT COLLABORATED.

BULLER

MONDAY THROUGH THURSDAY...MAIN CONCERN WITH THIS PERIOD WILL BE THE
EVOLUTION OF THE TROUGH FROM THE WEST COAST TO THE HIGH PLAINS BY MID
WEEK. MODELS ARE TRENDING THE TROUGH FURTHER NORTH THAN PREVIOUS
RUNS WHICH WILL GIVE US A BETTER CHANCE FOR PRECIPITATION. HOWEVER
THE MODELS DISAGREE HOW FAR NORTH THE TROUGH WILL TRACK AND HOW FAST
IT WILL MOVE ACROSS THE HIGH PLAINS. CURRENTLY WEDNESDAY LOOKS TO BE
THE BEST OPPORTUNITY FOR PRECIP. GENERALLY THE EASTERN CWA WILL HAVE
A BETTER SHOT AT PRECIP. AS THE TROUGH MOVES NORTHEAST ACROSS THE
AREA. STILL UNSURE ABOUT THE PHASE OF THE PRECIP. GENERALLY LOOKS
TO BE A RAIN AND SNOW MIX IN THE MORNING...FOLLOWED BY PREDOMINANTLY
RAIN IN THE AFTERNOON THEN TRANSITIONING TO SNOW OVERNIGHT.

TEMPERATURES ARE ALSO DIFFICULT TO NAIL DOWN DUE TO THE DIFFERING
TRACKS OF THE TROUGH AMONG THE MODELS. GENERALLY LOOKS TO BE
SLIGHTLY BELOW NORMAL THROUGH WEDNESDAY FOLLOWED BY NEAR NORMAL
TEMPERATURES AFTER THAT.

JTL
&&

.AVIATION...
1112 PM MST THU DEC 8 2011

PREVAILING IFR CONDITIONS WITH OCCASIONAL TRANSITIONS TO MVFR AND
LIFR CONDITIONS WILL CONTINUE AT BOTH KMCK AND KGLD THROUGH THE
NIGHT WITH AN EVENTUAL TRANSITION TO VFR AT KGLD BY 13Z AND KMCK
BY 15Z AS DRYER AIR MOVES INTO THE REGION FROM THE NORTHWEST.

LOCKHART
&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&

AREA FORECAST DISCUSSION

NWS TOPEKA KS

250 AM CST FRI DEC 9 2011

.DISCUSSION...

SHORT RANGE FORECAST (TODAY AND SATURDAY)...

AT 8Z LIGHT SNOW IN RESPONSE TO SOME LOW LEVEL FRONTOGENESIS WAS
WINDING DOWN ACROSS FAR NORTHEASTERN KANSAS AS THE AREA OF 850 MB
FRONTOGENESIS MOVED OFF TO THE EAST. NO ACCUMULATION ASIDE FROM A
DUSTING OF SNOW ALONG THE FAR NORTHEAST CORNER OF KANSAS AND
SOUTHEAST CORNER OF NEBRASKA WAS REPORTED FROM THESE LIGHT SNOW
SHOWERS. A SURFACE RIDGE WHICH EXTENDS FROM SOUTHERN KANSAS
NORTHWARD TO THE WESTERN DAKOTAS WILL ALLOW LIGHT NORTHERLY FLOW
AND SUBSEQUENT COLD AIR ADVECTION INTO NORTHERN AND CENTRAL KANSAS.
ACROSS THE SOUTHERN EDGE OF THE SURFACE RIDGE A FAIRLY SHALLOW
STRATUS LAYER WILL PERSIST THROUGH THE MORNING HOURS BEFORE SLOWLY
DISSIPATING THIS AFTERNOON. AS A RESULT OF THE AMPLE CLOUD COVER
THROUGH THE FIRST HALF OF THE DAY AND THE WEAK COLD AIR ADVECTION
INTO THE AREA HAVE OPTED TO GO ON THE LOWER SIDE OF THE MET/MAV
GUIDANCE ENVELOPE FOR FRIDAY`S HIGH TEMPS. WITH SKIES CLEARING OUT
BY EVENING AND WITH THE SURFACE RIDGE BECOMING MORE CENTERED OVER
NORTHEAST KANSAS EXPECT TEMPERATURES TO BE A BIT COOLER ON
SATURDAY MORNING THAN FRIDAY MORNING...ONCE AGAIN OPTING FOR THE
LOWER END OF THE GUIDANCE ENVELOPE FOR SAT MORNING
LOWS...ESPECIALLY IN LOW LYING AREAS AND RIVER VALLEYS. FOR
SATURDAY SOUTHERLY WINDS WILL ALLOW WARMER AIR TO TRICKLE INTO THE
AREA AND WILL WORK IN CONJUNCTION WITH A WEAKLY AMPLIFIED 500 MB
RIDGE TO BRING A GRADUAL WARMING TREND TO NORTHEAST KANSAS FOR
THIS WEEKEND.

MID-RANGE AND EXTENDED FORECAST (SUNDAY THROUGH THURSDAY)...

EXPECT INCREASING CLOUDS FOR THE BEGINNING OF THE WEEK AS WARM AIR
ADVECTION WILL ALLOW FOR SOME MODEST ISENTROPIC ASCENT...AND BE
SOMEWHAT ENHANCED BY A QUICKLY MOVING SHORTWAVE TROUGH WHICH WILL
PASS THROUGH THE CENTRAL PLAINS. ALTHOUGH CLOUDS WILL INCREASE
DURING THIS TIME PERIOD EXPECT THE ASCENT TO BE WEAK AND MOISTURE
TO BE SHALLOW ENOUGH TO PRECLUDE ANY MENTION OF ACCUMULATING
PRECIP.

BY MID WEEK A DEEPLY AMPLIFIED SOUTHERN STREAM TROUGH WILL DIG
SOUTHWARD ALONG THE PACIFIC COASTLINE AND EJECT EASTWARD. AS IT
CROSSES THE DESERT SOUTHWEST IT WILL TAKE ON A NEGATIVE TILT WHICH
WILL CAUSE THE TRAJECTORY OF THE UPPER LOW TO TAKE MORE OF A EAST-
NORTHEAST COURSE AS IT TRAVERSES THE CENTRAL PART OF THE U.S.
EXPECT WARM AIR ADVECTION SHOWERS TO HOLD OFF UNTIL AFTER 12Z ON
WEDNESDAY...THEN INCREASE IN INTENSITY ONCE THEY BEGIN ON
WEDNESDAY. MODEL SOUNDINGS INDICATE DEEP ENOUGH SATURATION TO
WARRANT CONCERN FOR PERIODS OF MODERATE RAIN ACROSS THE FORECAST
AREA ON WEDNESDAY. GFS AND ECMWF INDICATE SOME MODEST ELEVATED
INSTABILITY WITH THIS SYSTEM...SO WILL INTRODUCE SOME ISOLATED
THUNDER FOR THE HEAVIER SHOWERS ON WEDNESDAY. THE SYSTEM LOOKS TO
BE FAIRLY PROGRESSIVE AND ECMWF/GFS AGREE ON A QUICK EXIT OF THE
SYSTEM BY THURSDAY MORNING. AS OF NOW THERMAL PROFILES SUGGEST
THIS EVENT WILL BE PRIMARILY RAIN...WITH SOME RAIN/SNOW MIXTURE ON
THE BACK SIDE OF THE SYSTEM AS COLD AIR FILTERS INTO NORTH CENTRAL
KANSAS ON WEDNESDAY NIGHT. WILL NAIL DOWN MORE SPECIFICS REGARDING THE
TIMING AND ANY POSSIBLE PRECIP TYPES OF THE SYSTEM AS IT
APPROACHES.

.AVIATION...
MAIN FORECAST CONCERN WILL BE WITH THE CIGS OVERNIGHT. OBS UPSTREAM
INDICATE A NARROW BAND OF IFR CIGS INITIALLY...BUT CIGS IMPROVE TO
VFR DEEPER INTO THE STRATUS ACROSS EASTERN NEB. RH PROGS FROM THE
NAM AND RUC AT 925MB SHOW A SATURATED LAYER REMAINING OVER THE
TERMINALS THROUGH THE MORNING. THEREFORE WILL KEEP AN PREVAILING
MVFR CIGS UNTIL 18Z WITH A TEMPO IFR FOR THE NEXT FEW HOURS. THERE
IS THE POTENTIAL FOR CIGS TO IMPROVE BEFORE NOON FRIDAY. RADAR
TRENDS AND MODEL OUTPUT CONTINUE TO POINT TOWARDS PRECIP REMAINING
TO THE NORTH SO WILL NOT MENTION AN PRECIP AT THIS TIME.

WOLTERS

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION

NWS DODGE CITY KS

1131 PM CST THU DEC 8 2011

.UPDATE...

.AVIATION /FOR THE 06 UTC TAF ISSUANCE/

FOG IS RAPIDLY DEVELOPING ALONG A CORRIDOR FROM ABOUT DDC THROUGH
GCK AND WESTWARD TO THE COLORADO LINE. THIS IS PARTIALLY DUE TO
STRONG RADIATIONAL COOLING AND ALSO SURFACE MOISTURE CONVERGENCE.
FOLLOWING THE RAPID RUC REFRESH MODEL, THE FOG WILL LIKELY CONTINUE
OVER THE NEXT SEVERAL HOURS BEFORE ADVECTING SOUTHWARD AS THE
STRATUS THICKENS ACROSS THE AREA. THEREFORE ALTHOUGH VISIBILITIES
MAY IMPROVE ACROSS THE AREA, CATEGORIES MAY STILL REMAIN IN THE
IFR/LIFR CATEGORIES THROUGH ABOUT 15 UTC OR SO.

PREV DISCUSSION... /ISSUED 352 PM CST THU DEC 8 2011/

DISCUSSION...

DAYS 1-2...

DAYS 3-7...

.PRELIMINARY POINT TEMPS/POPS...
DDC 19 41 17 44 / 0 0 0 0
GCK 17 36 16 42 / 0 0 0 0
EHA 19 35 17 44 / 0 0 0 0
LBL 20 42 20 44 / 0 0 0 0
HYS 17 35 14 41 / 10 0 0 0
P28 22 41 16 46 / 10 0 0 0

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

FN99/99

AREA FORECAST DISCUSSION

NWS TOPEKA KS

1114 PM CST THU DEC 8 2011

...AVIATION UPDATE...

.DISCUSSION...
SEE PREV DISCUSSION.

WOLTERS

.PREV DISCUSSION... /530 PM CST THU DEC 8 2011/
THE 18Z FORECAST SOUNDINGS FROM THE RUC/NAM/GFS ALL SHOW MID LEVELS
OF THE ATMOSPHERE DRYING OUT AFTER 03Z TONIGHT. BECAUSE OF THIS
THERE MAY NOT BE ANY ICE CRYSTALS WITHIN THE CLOUD WHICH WOULD BRING
IN THE POSSIBILITY FOR A LIGHT FREEZING MIST OR DRIZZLE OVERNIGHT.
FORTUNATELY THERE DOES NOT APPEAR TO BE MUCH LIFT WITHIN THE CLOUD
FOR DRIZZLE TO FORM. SO ANY PRECIP THAT FALLS OVER NORTHEAST KS LATE
THIS EVENING AND OVERNIGHT SHOULD BE LIGHT...BUT THERE IS A SMALL
PROBABILITY FOR SOME VERY LIGHT FREEZING PRECIP INSTEAD OF SNOW.
WILL NEED TO KEEP AN EYE ON THIS AS THE NIGHT PROGRESSES.

WOLTERS

/309 PM CST THU DEC 8 2011/
TODAY THROUGH FRIDAY...ON CURRENT WATER VAPOR IMAGERY AN UPPER LEVEL
TROUGH IS MOVING SOUTHEAST OUT OF THE NORTHERN PLAINS DOWN INTO THE
CENTRAL PLAINS. CURRENT RADAR TRENDS INDICATE WIDESPREAD
PRECIPITATION ACROSS CENTRAL NEBRASKA MOVING TO THE SOUTHEAST. LIGHT
SNOW HAS BEEN FALLING FOR MUCH OF THE DAY ACROSS CENTRAL NEBRASKA
WHERE ACCUMULATIONS UP TO 3 INCHES HAVE BEEN REPORTED. RADAR TRENDS
HAVE THE SOUTHEASTERN EDGE OF THE PRECIPITATION CURRENTLY ENTERING
NORTH CENTRAL KANSAS.

DRY LOW LEVELS WILL GRADUALLY SATURATE AS THE WAVE APPROACHES THE
REGION AS LOW LEVEL VERTICAL MOTION AND LIFT AHEAD OF THE UPPER
LEVEL TROUGH OCCURS. WITH THE ENTIRE VERTICAL PROFILE BELOW ZERO AND
SOME MOISTURE IN THE SNOW GROWTH REGION EXPECT THE DOMINANT
PRECIPITATION TYPE TO BE SNOW. PRECIPITATION SHOULD BEGIN IN NORTH
CENTRAL KANSAS LATER THIS AFTERNOON AND MOVE TO THE SOUTHEAST.
HOWEVER...AS SOON AS THE LOW LEVEL SATURATE THE VERTICAL MOTION
DISSIPATES. THE SUITE OF 12Z MODELS HAVE TRENDED FARTHER TO THE
NORTH WITH THE BEST MOISTURE AND LIFT REMAINING PRIMARILY OVER
NEBRASKA. HOWEVER...STILL EXPECT SOME LIGHT SNOW OVER NORTHERN
PORTIONS OF THE CWA WHERE THERE COULD BE SOME LIGHT ACCUMULATIONS OF
UP TO HALF AN INCH OVER PORTIONS OF THE CWA ALONG THE NEBRASKA
BORDER. PRECIPITATION WILL GRADUALLY COME TO AN END ACROSS THE CWA
BEFORE SUNRISE WITH A FEW LIGHT SNOW SHOWERS AND FLURRIES LINGERING
INTO THE DAY ON FRIDAY. CLOUDS WILL EVENTUALLY CLEAR FROM WEST TO
EAST ACROSS THE CWA ON FRIDAY AS THE UPPER LEVEL WAVE CONTINUES TO
MOVE TO THE SOUTH AND EAST. COLD AIR ADVECTION ON THE WESTERN SIDE
OF THE OF THE UPPER LEVEL TROUGH AND MOSTLY CLOUDY SKIES WILL KEEP
HIGH TEMPERATURES IN THE LOW TO MID 30S ACROSS THE CWA.

ANDERSON

CLEARING SKIES AND LIGHT WINDS WITH SURFACE HIGH EXITING KANSAS
SUGGESTS FRIDAY NIGHT COULD BE QUITE COLD...BUT MOISTURE LOOKS DEEP
ENOUGH TO KEEP STRONG NEAR-GROUND INVERSIONS IN CHECK.
CONVERSELY...WINDS MAY BE STRONG ENOUGH ALOFT TO KEEP FOG AT
BAY...BUT THIS WILL NEED TO BE WATCHED. LOW LEVEL WARM AIR ADVECTION
REGIME KICKS IN SATURDAY FOR TEMPS SEVERAL DEGREES ABOVE FRIDAY.
SLOWLY RETURNING SOUTHERN PLAINS MOISTURE AND WINDS STAYING UP WILL
PROVIDE A MUCH WARMER SATURDAY NIGHT THAN FRIDAY NIGHT AS WELL. LOW
LEVELS MOISTEN ENOUGH FOR SOME LOW CLOUD RETURN IN AT LEAST WESTERN
AREAS SUNDAY ON SOUTH TO SOUTHWEST WINDS. WILL NEED TO KEEP AN EYE
ON A WEAK WAVE MOVING THROUGH SUNDAY NIGHT INTO EARLY MONDAY FOR
POSSIBLE SHOWER ACTIVITY...BUT LACK OF GOOD DEPTH OF MOISTURE UNDER
RELATIVELY WARM TEMPS ALOFT SUGGESTS KEEPING THESE PERIODS DRY.

MAIN WEATHER FEATURE OF NOTE FOR THE LATER PERIODS CONTINUES TO BE
THE UPPER LOW AND ITS TRAJECTORY AND TIMING FOR THE TUESDAY NIGHT
INTO THURSDAY PERIODS. RUN-TO-RUN AND MODEL-TO-MODEL CONSISTENCY IS
STILL LACKING...EVEN BY TUESDAY AFTERNOON...AND HARD TO GO TOO HIGH
ON PRECIP CHANCES AT THIS POINT. GIVE THE LARGE CONSISTENCY
PROBLEMS...ITS NOT SURPRISING TO SEE GFS ENSEMBLES SHOWING HIGH
UNCERTAINTY WITH 850MB TEMPERATURES DURING THE MOST LIKELY PRECIP
TIMES...AND WILL KEEP PRECIP TYPE FORECAST RATHER BROAD AT THIS
POINT...BUT SOME FROZEN OR FREEZING PRECIPITATION COULD MATERIALIZE
IN MAINLY NORTHERN AND WESTERN LOCATIONS.

.TOP WATCHES/WARNINGS/ADVISORIES...NONE.

AREA FORECAST DISCUSSION...UPDATED AVIATION

NWS ST LOUIS MO

1140 PM CST THU DEC 8 2011

CARNEY

.DISCUSSION...
/335 PM CST THU DEC 8 2011/

GLASS

SKIES TO CLEAR OUT BY LATE FRIDAY EVENING AND WITH LIGHT AND
VARIABLE WINDS...TEMPS TO DROP INTO THE TEENS MOST LOCATIONS.

BYRD

.AVIATION...
/1140 PM CST THU DEC 8 2011/

BAND OF SNOW WITH LIGHT ACCUMULATION STAYED JUST SOUTH OF KUIN
THIS EVENING...THOUGH THERE IS AN ADDITIONAL AREA OF SNOW MOVING
ACROSS NORTHERN MISSOURI. WILL KEEP LIGHT SNOW GOING THROUGH THE
NIGHT AT KUIN WITH SOME LIGHT ACCUMULATIONS POSSIBLE THROUGH 12Z.
STILL LOOKS LIKE ONLY FLURRIES FARTHER SOUTH AT KSTL/KSUS. THERE
ARE IFR CEILINGS AT KIRK CURRENTLY...AND HAVE LEFT MVFR CEILINGS
GOING AT KUIN...BUT STILL THINK CEILINGS WILL REMAIN VFR FARTHER
SOUTH AT KCOU/KSTL/KSUS. ANY LINGERING SNOW WILL EXIT THE REGION
EARLY ON FRIDAY MORNING WITH VFR CONDITIONS.

SPECIFICS FOR KSTL...EXPECT MAINLY VFR CONDITIONS THROUGH THE
PERIOD WITH THE POTENTIAL FOR FLURRIES BETWEEN 08-14Z. LIGHT AND
VARIABLE WINDS WILL BECOME NORTHERLY BY EARLY FRIDAY.

BRITT

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

WFO LSX

AREA FORECAST DISCUSSION

NWS GLASGOW MT

919 PM MST THU DEC 8 2011

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT...
FAST SLIGHTLY CYCLONIC NW FLOW ALOFT...WITH A WEAK SHORTWAVE IN
IT CAUSING CLOUDY SKIES AND A FEW SNOWFLAKES THIS EVE. MOIST
LAYER/CLOUDS NOT VERY DEEP. MODELS INDICATE SHORTWAVE TO BE OUT OF
THE AREA BY MIDNIGHT...HRRR MODEL SHOWING WEAK 88D ECHOES ENDING
TOO. WILL LIMIT WEATHER TO JUST SCATTERED EVENING FLURRIES.

CLOUDY SKIES EXTEND WELL UPSTREAM ALONG THE FAST JET THOUGH...BUT
EXPECT IT TO BECOME BROKEN. NE THIRD OF CWA IS CLEAR...BUT WON`T
EXPAND A LOT WEST AND SOUTH. 00Z KGGW SOUNDING SHOWED THE COOLING
OF THE AIRMASS BELOW 700 MB IN THE PAST 24 HOURS...HOWEVER THE
COLD ADVECTION ENDED THIS AFTERNOON. FORECAST LOWS LOOK
GOOD...ALREADY A LITTLE BELOW ZERO IN THE CLEAR AREA.

POLAR HIGH PRESSURE HAS FRAGMENTED INTO PIECES...ONE PART OVER NE
MT. MODELS INDICATE PRESSURE GRADIENTS WITH THIS RELAX
OVERNIGHT...SO WHILE A FEW PLACES ARE OVER 10 MPH ON WINDS THIS
EVE...WINDS TO BE ALL UNDER 10 MPH LATER TONIGHT...SO NO
WIND CHILL ADVISORY ISSUED...BUT WEATHER STORY/HAZARDOUS WEATHER OUTLOOK
DESCRIBE IT WELL. SIMONSEN

PREVIOUS SHORT TERM...FOR NORTHEAST MONTANA TONIGHT THROUGH
SATURDAY...WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD SHOWING
THE VERY STRONG AND CLOSED UPPER LOW CENTER OVER HUDSON BAY AND
ITS ASSOCIATED LARGE SCALE UPPER TROUGH SPREADING OVER A LARGE
PORTION OF THE NORTH AMERICAN CONTINENT. JUST RECENTLY THIS
AFTERNOON THE BASE OF THE STRONGER PORTION OF THE LARGE TROUGH HAS
TAKEN ON A STRANGE SQUARISH SHAPE. VERY SLIGHT LARGE SCALE
TROUGHING IS ALSO PRESENT IN THE SOUTHERN STREAM ACROSS THE
SOUTHERN U.S. STATES. AN UPPER LEVEL RIDGE AND ITS ASSOCIATED AREA
OF HIGH PRESSURE IS GAINING STRENGTH JUST OF THE PACIFIC NORTHWEST
COAST.

LOCALLY...CLOUDS QUICKLY FORMED OVER THE CWA TODAY RIGHT ALONG THE
SURFACE RIDGE AXIS WITH CLEARER SKIES OFF TO THE NORTHEAST AND
CLOUDY SKIES CENTRAL AND SOUTHWEST. ENOUGH ASCENT IS PRESENT TO
SET OFF SOME VERY LIGHT VIRGA AND MAYBE SOME FLURRIES AS IS
EVIDENCED BY THE LIGHT RADAR REFLECTIVITIES TODAY. THE HRRR MODEL
HAS BEEN VERY ACCURATE IN DEPICTING THIS ACTIVITY WHEREAS THE
OTHER OPERATIONAL MODEL SOLUTIONS DID NOT BOTHER MUCH WITH IT.
TRIED TO FOLLOW THE TREND OF THIS HRRR MODEL FOR THE VERY NEAR
SHORT TERM THROUGH TONIGHT AS FLURRIES SHIFT SOUTHWEST AND
DIMINISH SOUTHWARD. ALSO...TONIGHT...WIND CHILL VALUES WILL
APPROACH 20 BELOW ZERO AGAIN ESPECIALLY OVER OUR FAR NORTHEAST
ZONES. BUT WITH WINDS FORECASTED BELOW 10 MPH...FELT IT WAS
SUFFICIENT TO ONLY MENTION IT IN THE HWO.

BEGINNING FRIDAY...THE ARCTIC AIR MASS AND HUDSON BAY LOW QUICKLY
GIVE WAY TO THE APPROACHING HIGH PRESSURE AND WARMER TEMPERATURES
FROM THE WEST. HIGHS SHOULD REBOUND EASILY INTO THE MID 20S
CENTRAL AND WELL ABOVE FREEZING OVER OUR SOUTHWESTERN ZONES.
ANOTHER PERIOD OF CLOUDINESS WILL SWEEP OVER NORTHEAST MONTANA ON
FRIDAY BUT I EXPECT ANY PRECIPITATION TO REMAIN WELL NORTH OF THE
INTERNATIONAL BOARDER. TRIED TO SHOW THE TREND WITH SOME SILENT
POPS AND SKY COVER.

SATURDAY...THE UPPER RIDGE FLATTENS SOMEWHAT BUT STILL MANAGES TO
MAKE SIGNIFICANT INROADS INTO OUR AREA...BRINGING TEMPERATURES
ABOVE FREEZING TO ALL OF NORTHEAST MONTANA EXPECT THE FAR
NORTHEAST LITTLE CORNER. MOSTLY CLEAR SKIES AND NO PRECIPITATION
TO START THE WEEKEND. BMICKELSON

.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
MADE SOME INCREASES WITH POPS FOR SUNDAY NIGHT AND ESPECIALLY
MONDAY. A SYSTEM LOOKS STRONGER WITH SOME OF THE MODELS AND
CONSISTENT ON THE ECMWF. ALSO RAISED POPS SLIGHTLY NEAR THE END OF
THE PERIOD CLOSER TO CLIMATOLOGY WITH AN UPPER TROUGH IN THE
WESTERN STATES. REST OF FORECAST LOOKED GOOD. JAMBA

PREVIOUS DISCUSSION...
THE EXTENDED PERIOD FEATURES A SERIES OF SHORTWAVE TROUGHS AND
RIDGES IN A PROGRESSIVE PATTERN. LIMITED MOISTURE WITH EACH OF THE
WEATHER SYSTEMS WILL LIMIT PRECIP CHANCES. TEMPERATURES WILL BE
WITHIN 10 DEGREES OF NORMAL DURING THE WHOLE PERIOD.

AN UPPER RIDGE MOVES TO THE EAST SATURDAY NIGHT AND SUNDAY WITH AN
UPPER TROUGH MOVING THROUGH EASTERN MONTANA ON MONDAY. THIS WILL
BRING A DRY COLD FRONT ACROSS THE AREA ON SUNDAY. LOOK FOR
SOMEWHAT COLDER AIR SUNDAY NIGHT AND MONDAY.

SHORTWAVE RIDGE FOLLOWS ON TUESDAY. ECMWF CURRENTLY WARMER THAN
THE GFS WITH THE TEMPERATURES. WILL FORECAST ON THE COLDER SIDE OF
THE POSSIBILITIES FOR NOW GIVEN THAT LIGHT WINDS SHOULD LEAD TO
POOR MIXING WITH LOW LEVEL INVERSIONS TRAPPING COLD AIR AT THE
SURFACE.

ANOTHER SHORTWAVE TROUGH MOVES THROUGH THE AREA WEDNESDAY AND THURSDAY
WITH ANOTHER DRY COLD FRONT AND SOMEWHAT COLDER AIR. FORRESTER

.AVIATION...
VFR. CEILINGS WILL GENERALLY DISSIPATE ACROSS THE REGION THIS
EVENING AND OVERNIGHT. WINDS WILL REMAIN LIGHT AREA WIDE THROUGH
THE PERIOD. PROTON

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

WEATHER.GOV/GLASGOW

AREA FORECAST DISCUSSION

NWS NORTH PLATTE NE

349 AM CST FRI DEC 9 2011

.DISCUSSION...

LIGHT SNOW ASSOCIATED WITH A WEAK UPPER LEVEL SHORTWAVE WILL
CONTINUE ACROSS NORTH CENTRAL NEBRASKA THROUGH MID MORNING TODAY.
THE MAJORITY OF THE ACTIVITY WILL REMAIN LIGHT AT BEST...WITH MODELS
INDICATING ONLY MINIMAL QPF. THE GFS AND EURO ARE PREDOMINATELY
DRY...BUT BOTH THE NAM AND THE 09.05Z HRRR WOULD INDICATE THE
POTENTIAL OF A COUPLE HUNDREDTHS OF AN INCH OF ADDITIONAL QPF...WHICH
USING A SNOW RATIO OF 18 TO 1 WOULD YIELD ABOUT A QUARTER TO A
HALF OF AN INCH OF SNOW ACCUMULATION. BASED OFF OF RECENT
PERFORMANCE...THE HRRR SOLUTION SEEMS TO BE A GOOD COMPRISE. SO
TRENDED THE FORECAST IN THAT DIRECTION. LIGHT SNOW WILL QUICKLY
END BY LATE MORNING TODAY AS UPPER LEVEL SUPPORT AND THE
DISTURBANCE PUSHES EAST. ARCTIC HIGH PRESSURE THEN WILL SETTLE
ACROSS THE REGION. TEMPERATURES FOR TODAY STILL LOOK BELOW
AVERAGE...WITH GENERALLY HIGHS IN THE UPPER 20S. ACROSS NORTH
CENTRAL NEBRASKA...WHERE CLOUD COVER WILL HELP LIMIT TEMPERATURES
FURTHER...MID 20S MAY BE AS WARM AS IT GETS...BUT WITH CLEAR SKIES
ACROSS SOUTHWEST NEBRASKA...A FEW 30S ARE NOT OUT OF THE QUESTION.
THE SURFACE HIGH PRESSURE WILL CONTINUE TO THE SOUTHEAST OVERNIGHT
TONIGHT...WITH WARM AIR ADVECTION TO FOLLOW IN ITS WAKE. HIGHS FOR
SATURDAY MAY BE TRICKY THOUGH...AS SPREAD IN GUIDANCE SATURDAY
AFTERNOON IS RUNNING AS MUCH AS 10 DEGREES OR MORE ACROSS
SOUTHWEST NEBRASKA. THE DEGREE OF MIXING BETWEEN BUFR SOUNDING
REVEAL THE REASON FOR THE SPREAD. GENERALLY FOLLOWED A BLEND
APPROACH...WHICH MAY NOT BE THE BEST WAY TO HANDLE THE
SITUATION...BUT USING A BLEND ALLOWS FOR THE SLIGHT WARMUP WHICH
IS EXPECTED. LOOKING GENERALLY AT HIGHS IN THE UPPER 30S TO MID
40S ACROSS THE CWA. MORE OF THE SAME FOR SUNDAY...WITH SOUTHERLY
FLOW AND TEMPERATURES BACK IN THE 40S. THE DEGREE OF MIXING DOES
APPEAR GREATER BY MID AFTERNOON SUNDAY...HOWEVER H85 TEMPERATURES WILL
COOL ABOUT 3C DEGREES...SO LOOKING AT HIGHS A DEGREE OR TWO
COOLER THAN SATURDAY. A WEAK COLD FRONT WILL MOVE THROUGH SUNDAY
NIGHT INTO MONDAY...COOLING TEMPERATURES BACK INTO THE 30S FOR
HIGHS...AND TEENS FOR LOWS TO START THE WORK WEEK.

THINGS GET INTERESTING BY MID WEEK AS AN UPPER LEVEL LOW
APPROACHES THE FORECAST AREA. THE EUROPEAN SOLUTION CONTINUES TO
SHOW A NEGATIVELY TILTED TROUGH WHICH WOULD HAVE THE POTENTIAL TO
HAVE A STRONG IMPACT ON THE REGION. THE GFS SEEMS TO BE TRENDING
TOWARD THE EURO SOLUTION...BUT STILL SIGNIFICANT TIMING AND
LOCATION DIFFERENCES ARE EVIDENT. BOTH LONG RANGE MODELS DO
HOWEVER SUGGEST THAT THE GULF WILL BE WIDE OPEN...AS LOW 40 TD/S
MAY SNEAK BACK UP ACROSS OUR SOUTHEASTERN COUNTIES WEDNESDAY
AFTERNOON. IT WOULD BE QUITE POSSIBLE THAT RAIN WOULD BE THE
PRIMARY PTYPE BEFORE A CHANGE OVER TO SNOW LATE IN THE EVENT. WITH
IT BEING MID DECEMBER...WILL CONTINUE THE RAIN SNOW MIX ACROSS THE
EASTERN ZONES...WITH ALL SNOW OUT WEST....BUT AT LEAST THERE/S
PLENTY OF TIME TO HAMMER THIS OUT.

.AVIATION...

FOR THE KLBF AND KVTN TERMINALS THROUGH 12Z SATURDAY.

AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL TRACK FROM NORTHEASTERN
NEBRASKA INTO THE UPPER MISSISSIPPI VALLEY TODAY. THIS FEATURE WILL
SPREAD MID TO HIGH LEVEL CLOUDINESS ACROSS THE REGION BEFORE IT
EXITS EAST. IN ADDITION TO ABUNDANT MID TO HIGH LEVEL VFR
CLOUDINESS...MVFR CEILINGS ARE LIKELY THIS MORNING AT BOTH
TERMINALS. FOR LOCATIONS ALONG AND SOUTH OF INTERSTATE 80...IFR
CEILINGS WITH SURFACE VISBYS AS LOW AS 3SM ARE POSSIBLE THROUGH MID
MORNING. SKIES WILL BECOME MOSTLY CLEAR TONIGHT WITH VFR CONDS
EXPECTED. SURFACE WINDS WILL BE VARIABLE AT UNDER 10 KTS TDY WITH A
GRADUAL SHIFT TO THE WEST AT AROUND 10 KTS TONIGHT.

.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&

SHORT TERM/EXTENDED...JACOBS
AVIATION...CLB

AREA FORECAST DISCUSSION

NWS NORTH PLATTE NE

1146 PM CST THU DEC 8 2011

.AVIATION...

LIGHT WINDS WILL CONTINUE OVER WESTERN NEBRASKA THROUGH THE DAY ON
FRIDAY...WEST TO NORTHWEST AT LESS THAN 10KTS. MAINLY VFR CONDITIONS
OVER WESTERN NEBRASKA WITH SOME MVFR OVER EXTREME SOUTHWEST NEBRASKA
FROM KOGA TO KIML. SOME FLURRIES OVER THE DAKOTAS MY MOVE INTO NORTH
CENTRAL NEBRASKA FROM KVTN TO KONL BUT CONFIDENCE NOT HIGH AND HAVE
IN A TEMPO GROUP. GENERAL TREND WITH MODELS INDICATES SKIES OVER
WESTERN NEBRASKA CLEARING OUT AFTER SUNRISE.

.PREV DISCUSSION... /ISSUED 348 PM CST THU DEC 8 2011/

HYDROLOGY...

.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&

SHORT TERM/EXTENDED...CDC
AVIATION...POWER

AREA FORECAST DISCUSSION

NWS FORT WORTH TX

350 AM CST FRI DEC 9 2011

.AVIATION...
09Z UPDATE...
CONCERNS REGARDING IFR AND POSSIBLE LIFR CIGS ARRIVING AT DFW
METRO AIRPORTS IS COMING TO FRUITION AND HAVE ADDED JUST IFR CIGS
WITH NO VSBY RESTRICTIONS FOR NOW. WACO LOOKS THE MOST LIKELY TO
SEE LIFR CONDITIONS AND RESTRICTIONS TO VSBY AS WELL. RUC BAK/OPS
40 AND WRF SOUNDINGS HANDLE THE CURRENT SITUATION MUCH BETTER THAN
THE GFS OR LAMP MOS.

WAA IS OCCURRING OVER A SHALLOW FRONTAL INVERSION CENTERED NEAR
925MB OR 2-2.5 KFT...THOUGH VEERED FROM THE WSW. STRENGTH OF FLOW
IS GENERALLY 15-25 KTS WHICH SHOULD KEEP RESTRICTIONS MORE RELATED
TO STRATUS VERSUS VSBY AT DFW METRO TERMINALS. WE WILL MONITOR
TRENDS CLOSELY. WE ARE EXPECTING A SLOWER FRONTAL ARRIVAL AFTER
18Z...VERSUS THE MORNING TIMING ADVERTISED BY THE GFS.

.DISCUSSION...
LIGHT SOUTH FLOW CONTINUES OVER NORTH TEXAS AND MOISTURE HAS BEGUN
TO RETURN SLOWLY ACROSS THE SOUTHERN HALF OF THE FORECAST AREA
THIS MORNING. DEWPOINTS HAVE STEADILY CREPT UP AND LOW STRATUS HAS
FORMED DURING THE PAST FEW HOURS SOUTH OF THE INTERSTATE 20
CORRIDOR. STRATUS IS SPREADING NORTH AND WILL LIKELY COVER THE
DALLAS-FORT WORTH METROPLEX BEFORE SUNRISE. THERE IS STILL THE
POTENTIAL FOR PATCHY FOG TO FORM BUT WITH THE COMBINATION OF
QUICKLY-DEVELOPING STRATUS AND THICKENING HIGH CLOUDS...THE
PROBABILITY FOR WIDESPREAD LOW VISIBILITIES SEEMS PRETTY SLIM.
WILL CONTINUE WITH THE MENTION OF FOG FOR AREAS GENERALLY SOUTH OF
INTERSTATE 20 WHERE HIGHEST LEVELS OF SHALLOW MOISTURE RESIDE.

MEANWHILE A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST THIS
MORNING AND CONTINUE ITS SLOW STEADY JOURNEY SOUTHEASTWARD
THROUGH THE AREA DURING THE DAY. WINDS WILL BACK TO THE NORTHEAST
AND THEN NORTH AS THE FRONT MOVES THROUGH. IT LOOKS LIKE THE
BOUNDARY WILL REACH THE METROPLEX BY NOON AND PUSH SOUTHEAST OF
THE REGION AROUND SUNSET. HIGH PRESSURE WILL BUILD BACK IN BEHIND
THE FRONT LEAVING THE AREA COOL AND DRY THROUGH SATURDAY.

ON SUNDAY...THE SURFACE RIDGE WILL SHIFT QUICKLY EAST AND BECOME
ESTABLISHED OVER THE EAST COAST. THIS WILL ALLOW RETURN FLOW TO
START UP AGAIN AND LOW LEVEL MOISTURE TO GRADUALLY INCREASE. A
WEAK SHORTWAVE EMBEDDED IN THE WESTERLIES WILL TRAVERSE THE REGION
DURING THE DAY SUNDAY BRINGING A SLIGHT CHANCE FOR SHOWERS TO
SOUTHERN COUNTIES.

AN UPPER LEVEL LOW WILL THEN DEEPEN OFF THE CALIFORNIA COAST AND
BEGIN ITS APPROACH FROM THE WEST EARLY IN THE WORK WEEK. MODELS
ARE COMING INTO BETTER AGREEMENT WITH THE SYSTEM OPENING UP AND
ACCELERATING OFF TO THE EAST-NORTHEAST ACROSS THE PLAINS. THE GFS
IS STILL FURTHER SOUTH THAN THE ECMWF WITH THE PATH OF THE MAIN
UPPER LEVEL FEATURE. EITHER WAY...NORTH TEXAS WILL SEE RAIN CHANCES
INCREASE AS WE APPROACH THE MIDDLE PART OF NEXT WEEK. THE BEST
CHANCE FOR RAIN WILL BE WEDNESDAY AS THE TROUGH AXIS SWINGS THROUGH
AND A PACIFIC FRONT MOVES THROUGH THE AREA. IT STILL LOOKS LIKE
INSTABILITY WILL BE MINIMAL WITH ML CAPES BELOW 500 J/KG FOR THE
MOST PART...BUT COMBINED WITH GOOD DYNAMICS...THUNDER IS STILL A
DECENT POSSIBILITY WEDNESDAY. RAIN CHANCES WILL LIKELY END ON
THURSDAY MORNING...AS THE SYSTEM MIGRATES EAST AWAY FROM NORTH
TEXAS.

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 54 31 50 32 51 / 0 0 0 5 10
WACO, TX 55 31 50 31 48 / 0 0 0 10 20
PARIS, TX 52 28 48 28 50 / 0 0 0 5 5
DENTON, TX 52 27 50 27 49 / 0 0 0 5 10
MCKINNEY, TX 52 28 49 27 50 / 0 0 0 5 10
DALLAS, TX 54 32 50 33 51 / 0 0 0 5 10
TERRELL, TX 55 30 49 29 50 / 0 0 0 5 10
CORSICANA, TX 55 32 51 32 47 / 0 0 0 5 10
TEMPLE, TX 57 32 52 32 50 / 0 0 0 20 20
MINERAL WELLS, TX 52 27 49 28 49 / 0 0 0 10 10

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

05/30

AREA FORECAST DISCUSSION

NWS CHARLESTON SC

704 AM EST FRI DEC 9 2011

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL TODAY. A COLD FRONT WILL MOVE THROUGH THE
REGION TONIGHT. HIGH PRESSURE WILL GENERALLY DOMINATE THROUGH THE
REMAINDER OF THE PERIOD.

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEAR-DAWN...ONSHORE ADVECTION OF MOISTURE IN THE LOWER LEVELS
ASSISTING EXPANDING STRATOCUMULUS DEVELOPMENT OVER THE FORECAST
AREA THIS MORNING BUT CLOUDS HAVE BEEN SLOW TO INCREASE OVER SE
SOUTH CAROLINA PRIOR TO DAWN. TEMPS AT DAYBREAK A FUNCTION OF
CLOUD COVER...LOW TO MID 30S WHERE SKIES STILL CLEAR...UPPER 30S
TO MID 40S WHERE CLOUDS HAVE BEEN PERSISTING.

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AT KSAV...VFR CIGS 4-6 KFT LOOKS TO HAVE SETTLED IN. THESE CIGS
SHOULD PERSIST THROUGH MUCH OF THE FORECAST PERIOD PRIOR TO 12Z/10.
THERE ARE SMALL CHANCES OF MVFR CIGS THIS MORNING AND AGAIN TONIGHT...
TOO LOW TO WORK INTO THE TAF.

AT KCHS...12Z SOUNDING WAS QUITE MOIST BUT CLOUDS FEW TO SCATTERED
THUS FAR. IT LOOKS LIKE CIGS WILL BE VFR 4-6 KFT WHEN THEY DO DEVELOP
AND PERSIST THROUGH TONIGHT. THERE ARE SMALL CHANCES OF BRIEF MVFR
CIGS THIS MORNING AND AGAIN TONIGHT. A FEW MODELS CONTINUE TO
INDICATE SMALL CHANCES FOR A FEW LIGHT SHOWERS OR SPRINKLES LATE
THIS AFTERNOON OR EVENING. CONFIDENCE IN EITHER MVFR OR RAIN MENTIONS
TOO LOW FOR MENTIONS AT THIS TIME.

EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED TO PREVAIL.

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

529 AM CST FRI DEC 9 2011

.AVIATION...
AS OF 5 AM...THE AXIS OF SNOW AND MVFR CONDITIONS HAD PUSHED
SOUTHEAST OF ALL TERMINALS. CLEARING SKIES AND VFR CONDITIONS WILL
PREVAIL THROUGH THE REST OF TODAY INTO TONIGHT AS STRONG HIGH
PRESSURE BUILDS INTO THE REGION. AS THE RIDGE MOVES IN...NORTHWEST WINDS
WILL BECOME LIGHT WESTERLY.
..SHEETS..

.PREV DISCUSSION... /ISSUED 330 AM CST FRI DEC 9 2011/

SYNOPSIS...
AREA RADARS AT 08Z INDICATED A BAND OF LIGHT SNOW EXTENDING ROUGHLY
FROM FAIRFIELD THROUGH THE QUAD CITIES TO STERLING. THIS WAS
ASSOCIATED WITH AN AXIS OF FRONTOGENESIS NORTH OF THE COLD FRONT
THAT HAS SETTLED WELL SOUTH OF THE AREA. BASED ON RADAR TRENDS AND
RECENT SNOWFALL MEASUREMENT OF .7 INCHES HERE AT DVN...IT APPEARS
THAT A WIDESPREAD .5 TO 1 INCH SNOWFALL EVENT HAS OCCURRED FOR
ROUGHLY THE AREA SOUTH OF INTERSTATE 80. THE FRONTOGENESIS WAS BEING
TRIGGERED BY BOTH A MID LEVEL IMPULSE ROUNDING THE BASE OF A
LONGWAVE TROUGH OVER NORTH CENTRAL U.S...AND THE ENTRANCE REGION TO
A 150 KT JET CORE EXITING TO THE NORTHEAST OUT OF THE GREAT LAKES
INTO EASTERN CANADA. AT THE SURFACE...THE COLD FRONT REACHED FROM
CENTRAL OK NORTHEAST THROUGH SOUTHERN MO TO SE LOWER MI. TO THE
NORTH...A RIDGE EXTENDED FROM A 1030 MB HIGH OVER EASTERN MT
SOUTHEAST ACROSS NEB INTO KS. UNDER THIS RIDGE...TEMPERATURES WERE
IN THE SINGLE DIGITS AND TEENS...WITH A FEW SUBZERO READINGS
DIRECTLY UNDER THE HIGH CENTER IN AREAS WITH DEEPER SNOWCOVER.

SHORT TERM...TODAY AND TONIGHT...
INITIAL FOCUS IS THE SNOW ENDING THIS MORNING...THEN TEMPERATURES AS
STRONG HIGH PRESSURE BUILDS AN ARCTIC AIRMASS INTO THE AREA BY
TONIGHT. LATEST RADAR TRENDS HAVE SHOWN A GENERAL WEAKENING TREND IN
THE SE TO NE BAND OF SNOW AS HAS TRANSITIONED E-SE OVER THE PAST
COUPLE HOURS. THIS ALIGNS WELL WITH THE RUC MODEL TRENDS INDICATING
RAPIDLY WEAKENING FRONTOGENESIS BETWEEN 06Z AND 12Z AS THE PRIMARY
MID AND UPPER LEVEL FORCING EXITS THE AREA. THIS...ALONG WITH AWIPS
DISTANCE-TIME TOOL SUGGESTS THE AXIS OF ACCUMULATING WILL LIKELY BE
OVER BY 12Z OVER THE AREA WITH FLURRIES FOR AN HOUR OR TWO TO FOLLOW
SOUTHEAST OF A KEOKUK TO GALESBURG LINE. LATEST MODELS SUGGEST A
SECOND WEAK VORT MAX AND AXIS OF MID LEVEL QG FORCING DROPPING
SOUTHEAST OUT OF SD INTO S CENTRAL IA BY 18Z. THIS WILL LIKELY BE
ENOUGH TO KEEP CLOUDS IN PLACE ACROSS THE SOUTH...BUT WITH A DEEP
DRY LOW LAYER IN PLACE BY THIS TIME...WILL MENTION ONLY FLURRIES FOR
ROUGHLY SOUTH OF HIGHWAY 34 THIS MORNING. TO THE NORTH...SKIES
SHOULD CLEAR BY MID MORNING...BUT WITH THE COMBINATION OF COLD
ADVECTION...REINFORCED BY FRESH SNOWFALL...DO NOT EXPECT MUCH
TEMPERATURE RECOVERY AND HAVE HELD HIGHS IN THE 20S.

LONG TERM...SATURDAY THROUGH NEXT THURSDAY...
DRY WITH MODERATING TEMPERATURES INTO THURSDAY...A MODERATE RAIN
EVENT LIKELY LATE WEDNESDAY INTO THURSDAY.

TUESDAY-WEDNESDAY...SLOW WARMING TREND CONTINUES AS SW CONUS UPPER
LOW STARTS TO MOVE INTO PLAINS WITH MODERATE WAA ON SOUTH WINDS
IMPACTING AREA BY MID/LATE WEDNESDAY PM. MOSTLY FAIR SKIES TO GIVE
WAY TO LOTS OF MID/HI CLOUDS BY WEDNESDAY AFTERNOON. TEMPERATURES TO
AVERAGE ABOUT 10 DEGREES ABOVE NORMAL WITH LIGHT WESTERLY WINDS TO
BECOME MODERATE SOUTH WINDS AS DISTURBANCE APPROACHES. ALL IN ALL...
REASONABLY NICE WEATHER FOR MID DECEMBER. HIGHS MAY REACH INTO THE
MIDDLE 40S FAVORED SOUTHERN LOCATIONS IF ENOUGH SUNSHINE AND BL
MIXING OCCURS WEDNESDAY PM. PRECIPITATION TO OVERSPREAD AREA LATE PM
AND ESPECIALLY WEDNESDAY NIGHT WITH GOOD WAA AS DISTURBANCE ROTATES
NE WITH SURFACE LOW PASSING TO OUR NW. SPEED OF SYSTEM AND SHEARING
FROM OPENING OF CLOSED SOUTH PLAINS UPPER LOW SUGGESTS 3-6 HOURS OF
LIGHT TO MODERATE RAIN. MOST AREA RAIN AMOUNTS ARE LIKELY TO TOTAL
25-.50 INCHES WITH LOCALIZED .75+ INCH AMOUNTS POSSIBLE NEAR TRIPLE
POINT AND ANY POTENTIAL DEFORMATION ZONE.

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

AREA FORECAST DISCUSSION

NWS GOODLAND KS

449 AM MST FRI DEC 9 2011

.DISCUSSION...
249 AM MST FRI DEC 9 2011

AGAIN FOR SUNDAY NIGHT WITH THE STRONG SOUTHERLY LOW LEVEL FLOW...
STRATUS AND POSSIBLY SOME FOG WILL SURGE BACK INTO THE AREA.

THANKS TO ALL THAT COLLABORATED.

BULLER

JTL
&&

.AVIATION...
431 AM MST FRI DEC 9 2011

VFR TO LIFR CONDITIONS WILL CAN BE EXPECTED FOR THE 12Z TAFS.
CURRENT SATELLITE IMAGES SHOW FOG/LOW STRATUS MOVING SOUTHEAST
ACROSS THE CENTRAL PLAINS. THE WESTERN EDGE OF THE LOW STRATUS
AND FOG LOOK TO BE DEFINED BY A WIND SHIFT TO THE NORTHWEST.
HRRR...SREF...AND RUC MODELS SEEM TO HAVE A GOOD HAND ON THE
LOCATION OF THE FOG AND STRATUS. CURRENT THINKING HAS A BRIEF
PERIOD OF LOWER VIS FOLLOWED BY VIS AND CEILING IMPROVING FOR KMCK
BY LATE MORNING. CLOUDS SHOULD BEGIN TO CLEAR OUT DURING THE
AFTERNOON AS WINDS TURN TO THE NORTHWEST. THE CLOUDS SHOULD CLEAR
OUT BY EVENING. AM SOMEWHAT CONCERNED THE MODELS MAY BE HANGING
ONTO THE LOW CEILING AND VIS TOO LONG JUDGING BY POSITION OF THE
EDGE OF STRATUS ON SATELLITE. BUT DO SEE SOME ADDITIONAL STRATUS
DEVELOPING OVER NORTHEAST COLORADO SO WILL LEAVE FORECAST AS IS.
FOR KGLD THE WEST WINDS HAVE KEPT CONDITIONS MVFR. CLIMO HAS SOME
LOW CEILINGS/VIS DURING THE EARLY MORNING...AND SURROUNDING SITES
HAVE LOWER VIS AND CEILING SO PLACED A TEMPO GROUP IN DURING THE
MORNING IN CASE WINDS CALM BRIEFLY. WINDS SHIFT TO THE NORTHWEST
AROUND 18Z SO CLOUDS SHOULD BEGIN TO CLEAR OUT SHORTLY AFTER THAT.

JTL
&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&

AREA FORECAST DISCUSSION

NWS NORTH PLATTE NE

617 AM CST FRI DEC 9 2011

.AVIATION...

FOR THE KLBF AND KVTN TERMINALS THROUGH 12Z SATURDAY.

AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL TRACK FROM NORTHEASTERN
NEBRASKA INTO THE UPPER MISSISSIPPI VALLEY TODAY. THIS FEATURE WILL
SPREAD MID TO HIGH LEVEL CLOUDINESS ACROSS THE REGION BEFORE IT
EXITS EAST. IN ADDITION TO ABUNDANT MID TO HIGH LEVEL VFR
CLOUDINESS...MVFR CEILINGS ARE LIKELY THIS MORNING AT BOTH
TERMINALS. FOR LOCATIONS SOUTH OF INTERSTATE 80...IFR CEILINGS WITH
SURFACE VSBYS AS LOW AS 3SM ARE POSSIBLE THROUGH MID MORNING. SKIES
WILL BECOME MOSTLY CLEAR TONIGHT WITH VFR CONDS EXPECTED. SURFACE
WINDS WILL BE VARIABLE AT UNDER 10 KTS TDY WITH A GRADUAL SHIFT TO
THE WEST AT AROUND 10 KTS TONIGHT.

.PREV DISCUSSION... /ISSUED 349 AM CST THU DEC 8 2011/

DISCUSSION...

.LBF WATCHES/WARNINGS/ADVISORIES...NONE.

SHORT TERM/EXTENDED...JACOBS
AVIATION...CLB

AREA FORECAST DISCUSSION

NWS BUFFALO NY

1100 AM EST FRI DEC 9 2011

.SYNOPSIS...
COLDER AIR WILL CONTINUE TO POUR OVER THE EASTERN GREAT LAKES TODAY
WITH LAKE EFFECT SNOW DOWNWIND OF BOTH LAKE ERIE AND
ONTARIO...INTENSIFYING TO MODERATE TO HEAVY LAKE BANDS TODAY.
INITIALLY...THE HEAVIEST SNOW WILL IMPACT AREAS NORTHEAST OF THE
LAKES...BEFORE THE WIND SHIFTS AND CAUSE THE SNOW TO SETTLE SLOWLY
TO THE SOUTH LATER FRIDAY AFTERNOON INTO FRIDAY NIGHT. THE LAKE
EFFECT SNOW WILL WIND DOWN EARLY SATURDAY OFF LAKE ERIE...AND MIDDAY
SATURDAY OFF LAKE ONTARIO AND THEN BE FOLLOWED BY DRY WEATHER ON
SUNDAY AS HIGH PRESSURE BUILDS ACROSS OUR REGION.

.NEAR TERM /THROUGH TONIGHT/...
CURRENT OBSERVATIONAL ANALYSIS SHOWS WIDESPREAD LIGHT SYNOPTIC SNOW
MOVING OFF INTO CENTRAL NY AS AN UPPER LEVEL JET OVER SOUTHERN
QUEBEC MOVES TO THE MOUTH OF THE ST LAWRENCE RIVER. IR CLOUD TOPS
ARE WARMING WITH SYNOPTIC SNOW WANING. THIS LEAVES A MEAGER AND
QUITE THIN LAKE EFFECT BAND OVER LAKE ERIE AND SOME LINGERING
MOISTURE OVER NIAGARA COUNTY AT 16Z. MORNING AMDAR DATA AND 12Z
SOUNDING DATA INDICATES AN 850MB TEMPERATURE AT AROUND -7C...AND 06
AND 12Z MODEL DATA SHOWS VERY SLOW COOLING...PERHAPS DOWN TO -8C
OVER THE NEXT 12 HOURS.

SATELLITE IMAGERY INDICATES NO REAL ENHANCEMENT UPSTREAM OVER LAKE
ERIE...AND WHILE CLE RADAR DOES SHOW SOME WEAK MULTI-BAND
FORMATION... LATEST HRRR AND 12Z GUIDANCE PACKAGES SUGGEST THE
MEAGER BAND WILL WORK ITS WAY SOUTH ACROSS NORTHERN ERIE AND OTHER
PORTIONS OF THE NIAGARA FRONTIER...DOWN ACROSS THE SOUTHTOWNS LATER
THIS AFTERNOON OR EARLY EVENING. AS THE BAND MOVES THROUGH...A 1-3
INCH ACCUMULATION IS POSSIBLE DEPENDING ON LOCATION. BUT WITH
SURFACE TEMPERATURES AT OR SLIGHTLY ABOVE FREEZING...AND MINIMAL
INCREASE IN INSTABILITY ALONG WITH NO IMMEDIATE SIGNS OF
INTENSIFICATION...WILL DROP WARNINGS FOR MOST OF THE NIAGARA
FRONTIER EXCEPT FOR NIAGARA COUNTY. OVER NIAGARA COUNTY...WARNING
AMOUNTS MAY STILL BE REALIZED WITH ONGOING SNOW BEFORE THE BAND
MOVES SOUTHWARD.

NO CHANGES FOR AREAS EAST OF LAKE ONTARIO.

FOR TONIGHT LAKE EFFECT SNOWS WILL FOCUS UPON SKI COUNTRY AND THE
WESTERN SOUTHERN TIER ON A WESTERLY FLOW. WINDS STILL WSW ACROSS
LAKE ONTARIO WILL BEGIN THE NIGHT WITH THE BAND ACROSS JEFFERSON AND
TOWARDS THE TUG HILL. AS THE UPPER LEVEL SHORTWAVE NEARS WINDS WILL
VEER TO WNW SHIFTING THE LAKE BANDS EVEN FURTHER SOUTHWARD. OUTSIDE
THE LAKE SNOWS THE PASSAGE OF THE UPPER LEVEL SHORT WAVE WILL
PRODUCE LIGHT SNOW SHOWERS AND FLURRIES ACROSS THE REGION.

THE ADDED COMPONENT OF UPSLOPE FLOW ACROSS THE CHAUTAUQUA RIDGE AND
THE TUG HILL WILL FOCUS THE HIGHEST SNOWFALL TOTALS HERE OVERNIGHT.
WILL HAVE TO MONITOR THE CHAUTAUQUA RIDGE AREA AS SNOWFALL TOTALS
MAY EXCEED WARNING THRESHOLDS. WILL WAIT TO SEE HOW SIGNIFICANT THE
LAKE BAND DEVELOPS OFF BOTH LAKES THIS MORNING BEFORE MAKING ANY
DECISIONS FOR THE OVERNIGHT TIME PERIOD.

AS FOR TEMPERATURES HIGHS WILL REACH ABOVE FREEZING FOR MUCH OF THE
CWA. INTERIOR PORTIONS OF THE GENESEE VALLEY MAY EVEN REACH THE 40
DEGREE MARK EARLY AFTERNOON BEFORE TEMPERATURES BEGIN TO FALL. FOR
TONIGHT. LOWS WILL FALL BACK INTO THE 20S.

FOR SPECIFIC SNOWFALL TOTALS...PLEASE SEE BUFWSWBUF OR THE LATEST
GRAPHICS ON OUR WEB PAGE AT WWW.WEATHER.GOV/BUFFALO.

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
LAKE SNOWS WILL BE WINDING DOWN AT THE START OF THIS PERIOD AS A
MASSIVE AREA OF HIGH PRESSURE WILL QUICKLY MAKE ITSELF RELEVANT
ACROSS OUR REGION. THIS WILL INITIALLY COME AS A RESULT OF ITS
ASSOCIATED STRONG SUBSIDENCE...THEN PART TWO WILL TAKE HOLD AS
IMPRESSIVE WARM ADVECTION WILL ONCE AGAIN BOOST OUR TEMPERATURES TO
ABOVE NORMAL LEVELS. THE DETAILS...

THE BASE OF A SHALLOW H5 TROUGH WILL RACE ACROSS OUR FORECAST AREA
ON SATURDAY WHILE EXPANSIVE SFC HIGH PRESSURE OVER THE MISSISSIPPI
VALLEY WILL NOSE NORTHEASTWARD ACROSS THE OHIO VALLEY...UP TO NEW
YORK STATE. THIS WILL KEEP A COLD (-12C @H85) WESTERLY FLOW IN PLACE
ACROSS LAKES ERIE AND ONTARIO...BUT IN TERMS OF LAKE EFFECT...MOST
IF NOT ALL OF THE VALUABLE MID LEVEL MOISTURE WILL HAVE BEEN
STRIPPED AWAY. THE ON GOING LAKE EFFECT ACTIVITY WILL BECOME STARVED
FOR MOISTURE AS A SHRIKING DENDRITIC GROWTH ZONE UNDER A LOWERING
CAP WILL SIGNAL THE END OF THE EVENT.

OFF LAKE ERIE...MULTIPLE BANDED LAKE SNOW SHOWERS EARLY IN THE DAY
WILL TAPER OFF TO FLURRIES BY LATE AFTERNOON. AS A RESULT...LITTLE
ADDITIONAL SNOW ACCUMULATION WILL BE EXPECTED ACROSS THE SRN TIER.

AS USUAL...THE ENDING WILL BE A SLOWER TO OCCUR EAST OF LK ONTARIO.
A LONGER FETCH FROM THE 280-290 FLOW WILL ENABLE ENOUGH LAKE
MOISTURE TO KEEP SNOW SHOWERS IN PLACE OVER THE TUG HILL THROUGHOUT
THE DAY...WITH A COUPLE MORE INCHES OF ACCUMULATION STILL POSSIBLE.

FOR THE REMAINDER OF THE FORECAST AREA...SATURDAY WILL BE THE
COLDEST DAY UP TO THIS POINT IN THE YOUNG SEASON. THE -12C H85 AIR
WILL ONLY SUPPORT SFC HIGHS IN THE UPPER 20S TO LOWER 30S FOR MOST
SITES WHILE BRISK WESTERLY WINDS WILL PRODUCE WIND CHILLS LARGELY IN
THE TEENS.

RIDGING AT ALL LEVELS WILL BUILD ACROSS THE LOWER GREAT LAKES
SATURDAY NIGHT...INCLUDING THE CENTER OF A STRONG SFC HIGH MAKING
ITS WAY TO PENNSYLVANIA. THE ASSOCIATED SUBSIDENCE AND INCREASINGLY
DRY AIRMASS WILL PRODUCE A MAINLY CLEAR AND COLD NIGHT OVER OUR
REGION...WITH LEFTOVER SNOW SHOWERS ON THE TUG HILL DYING OFF AS
FLURRIES.

THE SFC HIGH WILL MOVE OFF THE MID ATLANTIC COAST SUNDAY AND SUNDAY
NIGHT. THE RETURN FLOW IN ITS WAKE WILL ESTABLISH A DEEP WARM
ADVECTIVE FLOW...WITH H85 TEMPS CLIMBING FROM AN AVERAGE OF -6C
SUNDAY MORNING TO +2C BY LATE SUNDAY NIGHT. THIS WILL RESULT IN A
`CLEAN` WARM UP AS LITTLE MOISTURE WILL BE AVAILABLE FOR ISENTROPIC
LIFT TO GENERATE MUCH ALTO-CU. MORE IMPORTANTLY FOR MANY PEOPLE...
SFC TEMPS SUNDAY AFTERNOON WILL REBOUND INTO THE MID AND UPPER 30S
FOR MOST AREAS. FOR THE TYPICALLY WARMER GENESEE VALLEY...HIGHS
COULD EXCEED 40.

THE FAIR AND SEASONABLY MILD WEATHER CONDITIONS WILL CONTINUE ON
MONDAY AS HIGH PRESSURE CENTERED OFF THE COAST WILL NOSE BACK ACROSS
OUR REGION. BRIGHT SUNNY SKIES WILL HELP TEMPS CLIMB INTO THE LOW TO
MID 40S REGION WIDE WITH LIGHT WINDS. NORMAL HIGHS FOR THIS POINT IN
DECEMBER ARE GENERALLY IN THE MID 30S.

.LONG TERM /TUESDAY THROUGH THURSDAY/...
A LOW AMPLITUDE PACIFIC FLOW ACROSS SOUTHERN CANADA WILL KEEP ANY
REAL COLD AIR BOTTLED UP WELL TO OUR NORTH DURING THIS PERIOD...
WHILE A TRANSITORY RIDGE WILL HELP TO ACTUALLY BOOST OUR MERCURY
READINGS TO ABOVE NORMAL LEVELS. IN FACT...MEDIUM RANGE GUIDANCE IS
IN GENERALLY GOOD AGREEMENT THAT THE CHANCE FOR ANY TRUE COLD
INTRUSIONS WILL PROBABLY HOLD OFF UNTIL AT LEAST NEXT WEEKEND...
AND EVEN THAT OPPORTUNITY SHOULD BE FLEETING. HERE IS A CLOSER LOOK.

WEAKENING HIGH PRESSURE WILL BRING OUR FORECAST AREA ONE MORE DRY
DAY ON TUESDAY...ALTHOUGH MID AND UPPER LEVEL MOISTURE (IE. CLOUD
COVER) WILL INCREASE DURING THE COURSE OF THE DAY IN ADVANCE OF THE
NEXT SHORTWAVE.

THIS SHORTWAVE WILL CROSS THE REGION TUESDAY NIGHT...BUT WITH
LIMITED MOISTURE TO WORK WITH IN THE LOW LEVELS...WE SHOULD ONLY
EXPERIENCE NUISANCE MIXED PRECIPITATION.

A HIGH AMPLITUDE RIDGE OVER THE MISSISSIPPI VALLEY WEDNESDAY MORNING
WILL THEN PRESS EAST ACROSS THE UPPER GREAT LAKES AND OHIO VALLEY
WEDNESDAY AFTERNOON BEFORE NOSING ACROSS OUR REGION WEDNESDAY NIGHT.
THIS WILL OFFER US CLEARING SKIES AND A SHORT RETURN TO FAIR DRY
WEATHER.

THE RIDGE WILL MOVE EAST OF OUR REGION ON THURSDAY WHILE A CUTTER
TYPE STORM SYSTEM WILL LIFT FROM THE PLAINS TO THE UPPER GREAT
LAKES. THIS SCENARIO WILL ALLOW FOR SOME GULF MOISTURE TO WORK
NORTHWARDS ACROSS THE OHIO VALLEY AND UP INTO OUR REGION...WITH
SCATTERED RAIN SHOWERS BREAKING OUT DURING THE COURSE OF THE DAY.

.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
AT 12Z MVFR/IFR FLIGHT CONDITIONS WERE FOUND ACROSS THE REGION AS
LAKE EFFECT SNOW...COMBINED WITH SYNOPTIC SNOW FALL ACROSS THE
REGION. SYNOPTIC SNOWS WILL END FROM WEST TO EAST LATER THIS MORNING
WITH JUST THE LAKE SNOWS BEING THE PRIMARY SNOW MECHANISM. WILL
LOWER VSBYS DOWN TO 1/2SM FOR KIAG-KBUF-KART TERMINALS WITH THE LAKE
EFFECT SNOW BANDS.

TOWARDS EVENING WINDS WILL VEER...FIRST OVER LAKE ERIE AND DELAYED
SEVERAL HOURS OVER EASTERN LAKE ONTARIO ALLOWING FOR THE BANDS OF
SNOW TO BE FOCUSED ACROSS THE SOUTHERN TIER. THIS WILL ALLOW SNOWS
TO END ACROSS THE NORTHERN NIAGARA FRONTIER AND NORTHERN GENESEE
VALLEY.

WINDS...AS WELL AS LOW LEVEL LIFT WILL REMAIN FAVORABLE FOR LAKE
EFFECT SNOWS TO BE NEAR WATERTOWN THROUGH THE EVENING HOURS. EXPECT
A BAND OF SNOW OFF LAKE ONTARIO TO BE CENTERED JUST SOUTH OF
WATERTOWN BY LATE OVERNIGHT...WHILE A LESS BAND OF SNOW OFF LAKE
ERIE WEAKENS OVER THE SOUTHERN TIER.

OUTLOOK...
SATURDAY...MAINLY VFR WITH AREAS OF MVFR IN SNOW SHOWERS SOUTHEAST
OF THE LAKES.
SUNDAY AND TUESDAY...VFR.

.MARINE...
WILL CONTINUE THE SCA THROUGH TODAY AND INTO SATURDAY ON BOTH LAKE
ERIE AND ONTARIO AS CAA AND UPPER LEVEL TROUGH PASS ACROSS THE EASTERN
LAKES LATER TONIGHT AND SATURDAY. THOUGH CONDITIONS ON THE LAKES AT
PRESENT MOMENT ARE MAINLY BELOW SCA...WILL NOT DROP THE ADVISORIES
ONLY TO REISSUE FOR LATER TODAY AS WINDS AND WAVES WILL RETURN TO
SCA. WINDS ON THE RIVERS SHOULD REMAIN JUST BELOW SCA THROUGH
SATURDAY.

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW WARNING UNTIL 1 AM EST SATURDAY FOR NYZ007.
LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST
SATURDAY FOR NYZ006-019-020.
LAKE EFFECT SNOW ADVISORY UNTIL 6 PM EST THIS EVENING FOR
NYZ002-010-011.
LAKE EFFECT SNOW WARNING UNTIL 6 PM EST THIS EVENING FOR
NYZ001.
LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
NYZ012-085.
LAKE EFFECT SNOW WARNING UNTIL 3 AM EST SATURDAY FOR NYZ008.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST SATURDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR
LOZ043>045.
SMALL CRAFT ADVISORY UNTIL 10 PM EST SATURDAY FOR LOZ042.

SYNOPSIS...LEVAN/THOMAS
NEAR TERM...LEVAN/THOMAS/ZAFF
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...THOMAS
MARINE...THOMAS

AREA FORECAST DISCUSSION

NWS WILMINGTON NC

928 AM EST FRI DEC 9 2011

.SYNOPSIS...
A COASTAL TROUGH WILL DEVELOP A WEAK LOW PRESSURE CENTER OFFSHORE
LATER TODAY. THE LOW WILL LIFT NORTH OF THE AREA LATE TONIGHT AND
SATURDAY MORNING. SHOWERS ASSOCIATED WITH THIS FEATURE ARE EXPECTED
TO REMAIN MAINLY OFFSHORE...ALTHOUGH A FEW SPRINKLES COULD BRUSH THE
CAPE FEAR REGION. A REINFORCING AREA OF COOL AND DRY HIGH PRESSURE
WILL SLOWLY BUILD ACROSS THE REGION DURING THE WEEKEND AND PERSIST
THROUGH THE MIDDLE OF NEXT WEEK.

.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM FRIDAY...A COASTAL TROUGH HAS DEVELOPED BETWEEN THE
BEACHES AND THE FRYING PAN SHOALS WEATHER BUOY ABOUT 33 MILES
OFFSHORE. WIND DIRECTIONS ARE NORTHERLY ON THE BEACHES (AND INLAND)
WITH A SOUTHEAST WIND REPORTED OUT AT THE BUOY. THE LATEST FEW RUNS
OF THE HRRR APPEAR TO HAVE A GOOD HANDLE ON THIS FEATURE AND SHOW IT
REACHING ITS WESTERNMOST POINT WITHIN THE NEXT FEW HOURS...THEN
TURNING BACK OUT TO SEA THIS AFTERNOON AS SYNOPTIC LOW PRESSURE
BEGINS TO TAKE SHAPE FARTHER OFFSHORE. THIS MEANS WE SHOULD MAINTAIN
NORTH-NORTHEASTERLY SURFACE WINDS ACROSS THE EASTERN CAROLINAS
TONIGHT.

RADAR WIND PROFILES CONFIRM MODEL PROJECTIONS OF A RAPIDLY VEERING
WIND PROFILE WITH HEIGHT CURRENTLY. NORTH-NORTHEAST SURFACE WINDS
TURN EAST TO SOUTHEASTERLY 2000 FEET UP...THEN SOUTHERLY UP THROUGH
4000-5000 FT AGL. AS THE SYNOPTIC LOW DEVELOPS OFFSHORE THIS
AFTERNOON THIS SHOULD HELP WEAKEN THE ONSHORE FLOW ABOVE THE
SURFACE...ESPECIALLY ACROSS EASTERN SOUTH CAROLINA...WEAKENING ANY
ISENTROPIC LIFT WHICH HAS BEEN SUPPORTING THE LOW CLOUD DECKS
APPARENT ON SATELLITE IMAGERY AND SURFACE OBSERVATIONS. THERE IS A
VERY REAL POTENTIAL SKIES COULD BECOME MOSTLY SUNNY THROUGH A LARGE
PORTION OF THE AREA THIS AFTERNOON WITHOUT THE BENEFIT OF THE
ISENTROPIC LIFT. GIVEN THAT VIRTUALLY ALL MESOSCALE AND SYNOPTIC
MODELS SHOW CONSIDERABLE CLOUD COVER REMAINING THROUGH THE DAY WE
WILL SPLIT THE DIFFERENCE FOR NOW WITH SKY COVER FORECASTS...SHOWING
PARTLY CLOUDY SKIES CONTINUING. WE HAVE NUDGED HIGH TEMPERATURE
FORECASTS UP A COUPLE DEGREES ALONG COASTAL SOUTH CAROLINA WHERE THE
MOST SUNSHINE IS EXPECTED TODAY...ALTHOUGH UPWARD REVISIONS ARE
POSSIBLE ELSEWHERE IF CLOUDS DO NOT REDEVELOP IN THE AFTERNOON.

A FEW SPRINKLES (NON-MEASURABLE RAINFALL) ARE POSSIBLE IN THE CAPE
FEAR AREA LATE THIS MORNING OR EARLY THIS AFTERNOON...BUT MOS POPS
IN THE 20-30 PERCENT RANGE APPEAR TOO WET GIVEN THE MEAGER LIFT AND
MOIST LAYER DEPTH EXPECTED TODAY.

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...PASSAGE OF DRY COLD FRONT AROUND THE START OF
THE PERIOD WILL PUSH ANY LIGHT RAIN NEAR THE COAST FARTHER OFFSHORE
DURING SAT. COLD ADVECTION BEHIND THE FRONT WILL KNOCK TEMPERATURES
BACK TO CLIMO SAT AFTERNOON AND SLIGHTLY BELOW CLIMO SAT NIGHT. LOW
LEVEL NORTH TO NORTHWEST FLOW SAT VEERS TO NORTHEAST LATE IN THE DAY
AS CENTER OF CANADIAN HIGH MOVES OVER THE MID ATLANTIC STATES. MID
LEVEL RETURN FLOW DEVELOPS LATE SAT NIGHT AND SUN...AS THE MID LEVEL
RIDGE AXIS SHIFTS OFFSHORE...BUT LOW LEVELS REMAIN VERY DRY. LIGHT
RAIN MAY MOVE BACK OVER THE COASTAL WATERS LATER SUN INTO SUN NIGHT
BUT THINK THE MAIN IMPACT WILL BE INCREASED CLOUD COVER ALONG THE
COAST LATE IN THE PERIOD. ALTHOUGH COLD ADVECTION WILL SHUT OFF
LATER SAT COLD AIRMASS IN PLACE WILL KEEP HIGHS A FEW DEGREES BELOW
CLIMO SUN. CLOUD COVER ALONG THE COAST SUN NIGHT AND NORTHEAST FLOW
WILL RESULT IN A WIDE RANGE OF LOWS. INLAND AREAS WILL END UP A FE
DEGREES BELOW CLIMO WITH COASTAL SITES NEAR TO SLIGHTLY ABOVE CLIMO.

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...MEDIUM RANGE GUIDANCE HAS COME INTO BETTER
AGREEMENT TONIGHT AND FORECAST CONFIDENCE IS INCREASING A
LITTLE...MAINLY DURING THE EARLY PORTIONS OF THE PERIOD. WEAK
INVERTED TROUGH OFF THE SOUTHEAST COAST IS PULLED NORTHEAST MON BY
EXITING SHORTWAVE. LOOKS LIKE THE LIGHT RAIN ASSOCIATED WITH THE
TROUGH WILL REMAIN OFFSHORE SO HAVE NOT ADDED A POP FOR MON. PATTERN
ALOFT BECOMES ZONAL LATER MON IN THE WAKE OF EXITING SHORTWAVE. A
SECOND WEAK SHORTWAVE WILL PASS JUST NORTH OF THE AREA...ACCOMPANIED
BY A WEAK COLD FRONT...TUE NIGHT INTO WED. OTHER THAN AN INCREASE IN
CLOUD COVER AND A BRIEF PERIOD OF COLD ADVECTION EARLY WED.
GFS/ECMWF BOTH DEPICT BUILDING 5H RIDGE FROM THE GULF OF
MEXICO...BUT VARY ON HOW QUICKLY THE RIDGE BUILDS AND THE STRENGTH
OF THIS RIDGE LATE IN THE PERIOD. TEMPERATURES WILL BE NEAR CLIMO
THROUGH THE PERIOD WITH A SLIGHT MODERATING TREND LATE IN THE
PERIOD. SINCE THE WEAKER 5H RIDGE IN THE ECMWF IS FAVORED HAVE NOT
GONE TOO WARM WITH TEMPS AT THE END OF THE PERIOD.

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...WEAK ISENTROPIC LIFT AND CYCLOGENESIS OFF THE COAST WILL
CREATE STRATA CU DECKS AT VARYING LEVELS TODAY. BRIEF PERIODS OF
MVFR ARE POSSIBLE...BUT PREDOMINATELY VFR. A SPRINKLE IS POSSIBLE
ALONG THE COAST...WITH MINIMAL AVIATION IMPACTS. LIGHT NORTHEAST
FLOW WILL CONTINUE TODAY AS HIGH PRESSURE RECEDES.

EXTENDED OUTLOOK...VFR THROUGH SUNDAY. LOW CONFIDENCE FOR POSSIBLE
SHOWERS ALONG THE COAST MONDAY.

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM FRIDAY...A COASTAL TROUGH HAS DEVELOPED BETWEEN THE
COASTLINE AND THE FRYING PAN SHOALS BUOY. WIND DIRECTIONS AT THE
BEACHES ARE GENERALLY FROM THE NORTH...WHILE THE BUOY OFFSHORE IS
REPORTING A SOUTHEAST WIND. LATEST SHORT-TERM MODELS SUGGEST THE
TROUGH HAS NEARLY REACHED ITS WESTERNMOST POINT AND SHOULD BEGIN TO
DRIFT EAST THIS AFTERNOON AS SYNOPTIC-SCALE LOW PRESSURE DEVELOPS
ALONG IT WELL OFFSHORE. THIS MEANS NORTH TO NORTHEAST SURFACE WINDS
SHOULD PREDOMINATE THROUGH THE DAY INTO TONIGHT.

RADAR SHOWS SPRINKLES OR LIGHT SHOWERS MAINLY ACROSS THE OFFSHORE
WATERS. THE BEST CHANCE OF ANY OF THIS RAIN MAKING IT INTO THE
COASTAL WATERS EXISTS JUST TO THE SOUTH AND EAST OF CAPE FEAR DURING
THE LATE MORNING AND EARLY AFTERNOON HOURS.

SEAS WERE RUNNING A BIT HIGHER THAN INITIALLY FORECAST THIS
MORNING...AVERAGING 4 FT NORTH OF CAPE FEAR AND AROUND 3 FT THE
SOUTH. SPECTRAL WAVE ENERGY DIAGRAMS SHOW A SIGNIFICANT AMOUNT OF
THE WAVE ENERGY HAS A 9-SECOND SWELL PERIOD...WHICH THE WAVEWATCH
MODEL SHOWS IS MOVING IN FROM THE SOUTHEAST. FORECAST WAVE HEIGHTS
HAVE BEEN UPDATED THROUGH TONIGHT.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...NORTH TO NORTHEAST FLOW WILL CONTINUE THROUGH
THE PERIOD. GRADIENT TIGHTENS UP LATE SAT OR EARLY SUN WITH WINDS
AND SEAS EXPECTED TO EXCEED SCA THRESHOLDS AROUND MIDNIGHT. COLD
ADVECTION SAT NIGHT WILL ALSO LEAD TO SLIGHTLY STRONGER WIND GUSTS.
GRADIENT WILL REMAIN PINCHED SUN AND SUN NIGHT...WITH 20 TO 25 KT
WINDS CONTINUING THROUGH THE END OF THE PERIOD. PROLONGED STRONG
NORTHEAST FLOW CAUSE THE EAST-NORTHEAST WIND WAVE TO TRANSITION TO
AN EAST-NORTHEAST SWELL BETWEEN 5 AND 8 FT.

LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...NORTH TO NORTHEAST WINDS CONTINUE FOR MUCH OF
THE PERIOD WITH SPEEDS GRADUALLY DECREASING MON INTO TUE AS GRADIENT
RELAXES. SPEEDS IN THE 20 TO 25 KT RANGE MON MORNING DROP BELOW 20
KT BY MIDDAY AND CLOSE TO 15 KT BY MON EVENING. SEAS WILL RESPOND A
LITTLE SLOWER...WITH 6 TO 7 FT 7 TO 8 SECOND SWELLS TAKING SOME TIME
TO DROP BELOW 6 FT. SHOULD SEE ALL HEADLINES DROPPED BY TUE MORNING
WITH SCA WATERS AS EARLY AS MON EVENING. WINDS BACK AROUND TO
NORTH-NORTHWEST LATE IN THE PERIOD AHEAD OF NEXT WEAK COLD FRONT
EXPECTED TO CROSS THE WATERS LATE TUE NIGHT. GRADIENT REMAINS
UNCHANGED WITH OFFSHORE FLOW 10 TO 15 KT TUE.

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.

NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...DL

AREA FORECAST DISCUSSION

NWS NEWPORT/MOREHEAD CITY NC

914 AM EST FRI DEC 9 2011

.SYNOPSIS...
HIGH PRESSURE EXTENDING OVER THE AREA FROM THE NE WILL MOVE E TODAY
WHILE A WEAK TROUGH OF LOW PRESSURE LINGERS OFF THE COAST. LOW PRES
WILL DEVELOP ALONG THE TROUGH LATE TONIGHT AND A SECONDARY COLD
FRONT WILL MOVE ACROSS FROM THE WEST EARLY SATURDAY. HIGH PRESSURE
WILL BUILD IN FROM THE WEST SATURDAY NIGHT THROUGH THE MIDDLE OF
NEXT WEEK.

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 915 AM FRI...MIXED MID AND HIGH CLOUDS OVER THE AREA THIS
MORNING. ENOUGH SUNSHINE FILTERING THROUGH TO CONTINUE PARTLY
CLOUDY WORDING IN THE FORECAST. TEMPS ON TRACK. NO CHANGES NEEDED
TO ZONES THIS MORNING.

/PREVIOUS DISCUSSION/
AS OF 315 AM FRI...SHRT WVS IN SW FLOW ALOFT WILL SPREAD HIGH CLOUDS
OVER AREA EARLY THIS MORNING...THEN DEVELOPING ONSHORE FLOW EXPECTED
TO SPREAD SOME SCU IN BY LATE MORNING...LEADING TO A BIT MORE CLOUD
COVER THAN PREVIOUS FCST. NAM12 APPEARS OVERDONE WITH LIGHT QPF OVER
AREA DURING DAY AS NOT VERIFYING WELL WITH ACTIVITY FCST OF GA COAST
AT 06Z...THUS WILL KEEP DRY FCST. INCREASING LOW LVL THICKNESSES
SUPPORT MAXT TEMPS NEAR 60 EVEN WITH PT SUNNY SKIES.

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
AS OF 315 AM FRI...APPROACHING SHRT WV EXPECTED TO PRODUCE WEAK
CYCLOGENESIS ALONG COASTAL TROF BNDRY OVERNIGHT...AND ENOUGH SUPPORT
TO BRING 20 POPS ALONG OBX AND S COAST AFTER 10 PM. CLOUD COVER
THICKENING OVERNIGHT AS WELL. MOS BLEND IN DECENT AGREEMENT WITH
PREVIOUS FCST FOR MIN TEMPS...MAINLY LOW-MID 40S.

.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 315 AM FRI...EARLY PART OF THE LONG TERM PERIOD WILL FEATURE
MAINLY DRY WEATHER WITH BELOW NORMAL TEMPS. MED/LONG RANGE MODEL
SUITE IN GOOD AGREEMENT ON SYNOPTIC REGIME THROUGH EARLY NEXT WEEK.
UPR MIDWEST TROUGH WILL SWEEP EASTWARD THROUGH THE CONUS THIS
WEEKEND...BRINGING A TASTE OF A BRIEF COOLDOWN TO BELOW NORMAL TEMPS
TO E NC. AT THE SFC...A COLD FRONT WILL PUSH THROUGH THE REGION SAT
MORNING. RETURN FLOW WILL BE BRIEF OUT AHEAD OF THE FRONT...AND
LIMITED MOISTURE PER SOUNDING ANALYSIS INDICATES ONLY AN INC IN
CLOUDS EXPECTED SAT WITH THE FRONTAL PASSAGE. CONVERGENCE SLIGHTLY
BETTER OVER THE COASTAL WATERS WHERE A SHOWER OR TWO MAY GRAZE THE
OBX THROUGH SAT MORNING. DECENT CAA WILL TRANSLATE TO HIGH TEMPS IN
THE 50S ACROSS E NC...THOUGH GUSTY N WINDS WILL MAKE IT FEEL A BIT
COOLER. WINDS WILL BECOME LIGHT SAT NIGHT AND WITH CLEAR SKIES TEMPS
WILL PLUMMET INTO THE 20S INLAND WITH 30S IMMEDIATE COASTAL AREAS TO
LOW 40S OBX. THICKNESSES REMAIN LOW ON SUNDAY AFTERNOON SUGGESTING
MAX T`S 50-55 CWA WIDE. FLOW ALOFT BECOMES ZONAL EARLY NEXT WEEK
SUGGESTING TEMPS RETURNING TO NEAR AVERAGE FOR MID DEC. HIGH PRES
WILL REMAIN LODGED AT THE SFC EAST OF THE CENTRAL AND SOUTHERN
APPALACHIANS BRINGING CONTINUED DRY CONDITIONS.

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH FRIDAY EVENING/...
AS OF 915 AM FRIDAY...SCU CIGS AROUND 5K FT DEVELOPING S OF AREA
WILL SPREAD N-NE OVER TAF SITES THIS MORNING WITH ONSHORE FLOW
DEVELOPING IN 950-850 MB LAYER. VFR WILL PREVAIL THROUGH EVENING
THEN CIGS EXPECTED TO LOWER TO MVFR LATE TONIGHT AS DEVELOPING LOW
PRES MOVES ALONG COASTAL TROF.

LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 315 AM FRI...VFR CONDITIONS EXPECTED THROUGH THE LONG TERM.
CLOUDS WILL LINGER THROUGH SAT MORNING THOUGH REMAIN IN THE VFR
RANGE. WINDS WILL BECOME GUSTY OUT OF THE NORTH ON SAT FOLLOWING A
COLD FRONTAL PASSAGE. WINDS LIGHTEN SAT NIGHT BEFORE PICKING BACK
UP DURING THE DAY SUNDAY...THOUGH NOT AS GUSTY AS ON SAT. FOG/BR
SHOULD NOT BE AN ISSUE THROUGH THE WEEKEND AS DEWPOINTS WILL BE
QUITE LOW DUE TO DRY HIGH PRES MOVING INTO E NC.

.MARINE...
SHORT TERM /THROUGH TONIGHT/
AS OF 915 AM FRI...CURRENT MARINE ZONES IN GOOD SHAPE. LATEST OBS
FROM LAND/BUOYS MATCH UP WELL WITH FORECAST. NO CHANGES NEEDED
THIS MORNING.

WEAK LOW PRES DEVELOPING S OF AREA PRODUCING TIGHER PRES GRAD
WITH NE WINDS 15-20 KTS OBSERVED MAINLY S OF HAT. LATEST RUC13 HAS
DECENT HANDLE ON THIS TREND AND SUPPORTS STRONGER WINDS PERSISTING
MOST OF MORNING...THEN DECREASING THIS AFTN AS GRADIENT SLACKENS.
WINDS WILL INCREASE AGAIN LATE TONIGHT WITH SFC LOW DEVELOPMENT
ALONG TROF. WW3 AND SWAN IN AGREEMENT WITH PREVIOUS FCST
SEAS...WITH BUILDING SEAS LATE TONIGHT WITH INCREASING NE WINDS.

LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 315 AM FRI...ISSUED SCA BEGINNING SAT MORNING AS CONFIDENCE
IS HIGH THAT WINDS PICK UP DRAMATICALLY BEHIND A COLD FRONTAL
PASSAGE. SEAS WILL FOLLOW SUIT AS A WIND WAVE ABOVE 6 FT
DEVELOPS...PEAKING SAT NIGHT INTO SUN. WINDS WILL DIMINISH BELOW
SCA FOR THE SOUNDS SAT EVENING INTO EARLY SUN MORNING...THOUGH
REMAIN HIGH FOR THE COASTAL WATERS THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK. SHORT PERIOD WIND WAVE WILL TRANSITION TO A LONG
PERIOD NORTHEASTERLY SWELL NEXT WEEK AS A NW/SE GRADIENT REMAINS
ACROSS THE NC COASTAL WATERS DUE TO PERSISTENT HIGH PRES ACROSS
THE MID ATLANTIC/SOUTHERN APPALACHIANS. SEAS LOOK TO REMAIN ABOVE
6 FEET INTO TUESDAY AND POTENTIALLY INTO MIDDLE NEXT WEEK.

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY
FOR AMZ135.
SMALL CRAFT ADVISORY FROM 10 AM TO 7 PM EST SATURDAY FOR
AMZ130.
SMALL CRAFT ADVISORY FROM 10 AM SATURDAY TO 3 AM EST TUESDAY
FOR AMZ150-152-154.
SMALL CRAFT ADVISORY FROM 1 PM SATURDAY TO 3 AM EST TUESDAY
FOR AMZ156-158.

SYNOPSIS...JBM
NEAR TERM...HSA/JBM
SHORT TERM...JBM
LONG TERM...TL
AVIATION...HSA/JBM/TL
MARINE...HSA/JBM/TL

AREA FORECAST DISCUSSION

NWS NEWPORT/MOREHEAD CITY NC

700 AM EST FRI DEC 9 2011

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 630 AM FRI...HIGH CLOUDS HAVE THINNED PAST HOUR BUT MORE
SPREADING IN OVER WRN NC/SC AND SCU STARTING TO DEVELOP OVER SE NC
AND SPREADING N...THUS PT SUNNY FCST ON TRACK. NO CHANGE TO TEMPS.

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH FRIDAY EVENING/...
AS OF 645 AM FRIDAY...SCU CIGS AROUND 5K FT DEVELOPING S OF AREA
WILL SPREAD N-NE OVER TAF SITES THIS MORNING WITH ONSHORE FLOW
DEVELOPING IN 950-850 MB LAYER. VFR WILL PREVAIL THROUGH EVENING
THEN CIGS EXPECTED TO LOWER TO MVFR LATE TONIGHT AS DEVELOPING LOW
PRES MOVES ALONG COASTAL TROF.

.MARINE...
SHORT TERM /THROUGH TONIGHT/
AS OF 645 AM FRI...UPDATED FOR STRONGER WINDS OVER CENTRAL AND SRN
WATERS THIS MORNING. WEAK LOW PRES DEVELOPING S OF AREA PRODUCING
TIGHER PRES GRAD WITH NE WINDS 15-20 KTS OBSERVED MAINLY S OF HAT.
LATEST RUC13 HAS DECENT HANDLE ON THIS TREND AND SUPPORTS STRONGER
WINDS PERSISTING MOST OF MORNING...THEN DECREASING THIS AFTN AS
GRADIENT SLACKENS. WINDS WILL INCREASE AGAIN LATE TONIGHT WITH SFC
LOW DEVELOPMENT ALONG TROF. WW3 AND SWAN IN AGREEMENT WITH PREVIOUS
FCST SEAS...WITH BUILDING SEAS LATE TONIGHT WITH INCREASING NE
WINDS.

$$
SYNOPSIS...JBM
NEAR TERM...JBM
SHORT TERM...JBM
LONG TERM...TL
AVIATION...JBM/TL
MARINE...JBM/TL

AREA FORECAST DISCUSSION

NWS DENVER CO

1031 AM MST FRI DEC 9 2011

.UPDATE...NOW THAT THE FOG IS MOSTLY OUT OF MY TAF AIRPORTS I WILL
ADDRESS TEMPERATURES BEFORE NOON...IT IS PROBABLY A BIT TOO COLD.
THE SNOW AND FOG AREA NORTH OF DENVER WILL PLAY HAVOC WITH MAX AND
MIN TEMPS AND THE CHANCE OF FOG TONIGHT.

.AVIATION...FOG WILL MOST LIKELY DEVELOP OVER THE SNOWFIELD NORTH
OF DENVER AGAIN TONIGHT. MESOSCALE MODELS DO NOT AGREE WITH
RELATIVE HUMIDITY FORECASTS...SO IT IS TOUGH TO SAY IF FOG
REDEVELOPS ACROSS THE METRO AREA. HAVE PUT IN VCFG AS A FIRST GUESS.

.PREV DISCUSSION... /ISSUED 250 AM MST FRI DEC 9 2011/

SHORT TERM...DRY NW FLOW ALOFT WILL BE OVER THE AREA THRU TONIGHT.
HOWEVER WHAT APPEARS TO BE AN EASY FCST IS NOT DUE TO SHALLOW
INVERSIONS THAT WILL EXIST OVER LINGERING SNOWPACK ALONG THE FRONT
RANGE WHICH WILL AFFECT HIGH TEMPS. AREAS OF FOG AND LOW CLOUDS
HAVE DEVELOPED OVERNIGHT TO THE NORTH AND EAST OF DENVER WHICH WILL
LINGER THRU THE MORNING HOURS BEFORE BREAKING UP BY MIDDAY. BY AFTN
IT APPEARS A WK DENVER CYCLONE WILL BE IN PLACE NR DENVER WITH SLY
LOW LVL FLOW FM DENVER SOUTH ACROSS THE PALMER DIVIDE WHILE FM
DENVER NORTH TO GREELEY AND FORT COLLINS WINDS WILL BE LIGHT NNE.
HIGHS OVER THE SRN SUBURBS MAY REACH THE LOWER 40S WHILE ACROSS THE
NRN SUBURBS TO FORT COLLINS AND GREELEY READINGS MAY NOT GET OUT OF
THE 20S AS THE SHALLOW INVERSIONS HOLD SO A 20 DEGREE SPREAD IN
HIGHS ACROSS THE METRO AREA IS CERTAINLY NOT IMPOSSIBLE. OVER THE
PLAINS WILL KEEP READINGS MAINLY IN THE LOWER TO MID 30S.

LONG TERM...HIGH PRESSURE ALOFT WILL SHIFT OVER COLORADO ON
SATURDAY WITH A DRY AND WARMER AIRMASS IN PLACE ACROSS COLORADO. FOR
SUNDAY...THE NEXT UPPER LOW WILL BE DEVELOPING ALONG THE WEST COAST
WHICH WILL SHIFT THE FLOW ALOFT TO A LIGHT SOUTHWESTERLY OVER
COLORADO. IN ADDITION...THERE WILL BE A DEVELOPING SURFACE LEE TROF
AIDING TO THE WARMUP ALONG THE FRONT RANGE. TEMPERATURES WILL CLIMB
TO A BIT ABOVE SEASONABLE NORMALS THROUGH THE WEEKEND. THIS WILL
TAKE A GOOD BITE OUT OF THE SNOW COVER OVER THE FRONT RANGE.

AVIATION...IFR CONDITIONS HAVE DEVELOPED JUST TO THE NORTH OF THE
AIRPORT WITH CAMS SHOWING FOG ALONG E-470 AND ALONG I-76. THE NAM
AND RUC KEEP THESE LOW CLOUDS AND FOG NORTH OF THE AIRPORT THRU THE
MORNING HOURS WHILE THE HRRR SHOWS IT AFFECTING THE AIRPORT THRU 15Z
WITH VISIBILITIES DROPPING DOWN TO 1/4 MILE. IF WK DENVER CYCLONE
STAYS TO THE NE OF DIA AND SFC WINDS BECOME LIGHT NWLY THEN THE LOW
CLOUDS AND FOG MAY MOVE INTO THE AIRPORT BY 11Z. CURRENT TAF HAS
A TEMPO GROUP WITH VISIBILITIES DROPPING DOWN TO 1 MILE AND CEILING
AROUND 500 FT SO MAY HAVE TO ADJUST LOWER AS CONDITIONS DVLP. AFT
15Z THE HRRR SHOWS WINDS BECOMING SLY AND THEN SELY BY MIDDAY. IF
THAT HAPPENS THEN LOW CLOUDS SHOULD GRADUALLY ERODE BY MID TO LATE
MORNING WITH IMPROVING CONDITIONS. FOR TONIGHT EXPECT VFR
CONDITIONS WITH WINDS BECOMING DRAINAGE BY 02Z.

.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SHORT TERM...99
LONG TERM....99
AVIATION...RTG

AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

1152 AM CST FRI DEC 9 2011

.AVIATION...
VFR TAF CYCLE UNDERWAY AT ALL TERMINALS AS STRONG AND COLD HIGH
PRESSURE BUILDS INTO THE REGION OUT OF THE NORTHERN PLAINS. A WEAK
UPPER LEVEL WAVE CONTINUING TO ROLL ACRS THE SOUTHWEST HALF OF IA
THIS AFTERNOON WILL PRODUCE PASSING SCT-BKN AC AT LEVELS MAINLY 6K
FT AGL AND HIGHER ACRS MLI AND ESPECIALLY BRL THROUGH LATE
AFTERNOON BEFORE THESE SITES CLEAR OUT AGAIN. SOME LIGHT SNOW OR
FLURRIES POSSIBLE IN THE VCNTY OF BRL THIS AFTERNOON BUT MORE
LIKELY SOUTHWEST OF THAT TERMINAL. PREVAILING NORTHWEST SFC WINDS
AROUND 10 KTS WILL BECOME LIGHT WESTERLY AFTER SUNSET AS THE
SFC RIDGE BUILDS INTO THE REGION. ..12..

PREV DISCUSSION... /ISSUED 330 AM CST FRI DEC 9 2011/

.LONG TERM...SATURDAY THROUGH NEXT THURSDAY...
DRY WITH MODERATING TEMPERATURES INTO THURSDAY...A MODERATE RAIN
EVENT LIKELY LATE WEDNESDAY INTO THURSDAY.

TUESDAY-WEDNESDAY...SLOW WARMING TREND CONTINUES AS SW CONUS UPPER
LOW STARTS TO MOVE INTO PLAINS WITH MODERATE WAA ON SOUTH WINDS
IMPACTING AREA BY MID/LATE WEDNESDAY PM. MOSTLY FAIR SKIES TO GIVE
WAY TO LOTS OF MID/HI CLOUDS BY WEDNESDAY AFTERNOON. TEMPERATURES TO
AVERAGE ABOUT 10 DEGREES ABOVE NORMAL WITH LIGHT WESTERLY WINDS TO
BECOME MODERATE SOUTH WINDS AS DISTURBANCE APPROACHES. ALL IN ALL...
REASONABLY NICE WEATHER FOR MID DECEMBER. HIGHS MAY REACH INTO THE
MIDDLE 40S FAVORED SOUTHERN LOCATIONS IF ENOUGH SUNSHINE AND BL
MIXING OCCURS WEDNESDAY PM. PRECIPITATION TO OVERSPREAD AREA LATE PM
AND ESPECIALLY WEDNESDAY NIGHT WITH GOOD WAA AS DISTURBANCE ROTATES
NE WITH SURFACE LOW PASSING TO OUR NW. SPEED OF SYSTEM AND SHEARING
FROM OPENING OF CLOSED SOUTH PLAINS UPPER LOW SUGGESTS 3-6 HOURS OF
LIGHT TO MODERATE RAIN. MOST AREA RAIN AMOUNTS ARE LIKELY TO TOTAL
25-.50 INCHES WITH LOCALIZED .75+ INCH AMOUNTS POSSIBLE NEAR TRIPLE
POINT AND ANY POTENTIAL DEFORMATION ZONE.

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

AREA FORECAST DISCUSSION

NWS GOODLAND KS

1058 AM MST FRI DEC 9 2011

.DISCUSSION...
249 AM MST FRI DEC 9 2011

AGAIN FOR SUNDAY NIGHT WITH THE STRONG SOUTHERLY LOW LEVEL FLOW...
STRATUS AND POSSIBLY SOME FOG WILL SURGE BACK INTO THE AREA.

THANKS TO ALL THAT COLLABORATED.

BULLER

JTL
&&

.AVIATION...
1056 AM MST FRI DEC 9 2011

FOR THE 18Z TAFS...VFR CONDITIONS WILL PREVAIL THIS AFTERNOON AT BOTH
TERMINALS. A GOOD DEAL OF UNCERTAINTY EXISTS AFTER 00Z WITH REGARD TO
FOG/LOW STRATUS POTENTIAL. MODEL GUIDANCE SUGGESTS A GRADUAL LOWERING
OF DEWPOINTS THIS EVENING AND OVERNIGHT WITH MOS GUIDE NOT DEPICTING
ANY REDUCTIONS IN VIS OR CIGS. HOWEVER...WITH CONTINUED SNOW MELT THIS
AFTERNOON CONTRIBUTING TO A MOIST LOW LEVEL BOUNDARY LAYER...WITH VERY
LIGHT WINDS AND LITTLE SKY COVER INITIALLY THIS EVENING...PERSISTENCE
WOULD INDICATE THAT TEMPS SHOULD QUICKLY DROP TO NEAR DEWPOINTS BY 02Z-
04Z RANGE WITH VIS REDUCTION/LOW CIGS AS OCCURRED YESTERDAY EVENING.
FOR NOW WILL LOWER VIS TO MVFR LEVELS WITH A SCT LIFR DECK TO INDICATE
IFR AND EVEN SUB-IFR POTENTIAL.

050
&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&

AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

313 PM EST FRI DEC 9 2011

.SYNOPSIS...
AFTER SOME SNOW SHOWERS TONIGHT WITH A COLD FRONT...EXPECT DRY AND
COLD WEATHER FOR THE WEEKEND. THE NEXT CHANCE FOR PRECIPITATION
WILL NOT COME UNTIL TUESDAY NIGHT.

.NEAR TERM /THROUGH SATURDAY/...
LINE OF LIGHT RADAR RETURNS FROM SNOW SHOWERS CAN BE SEEN MOVING
STEADILY TO THE EAST ACROSS WESTERN OHIO AND EASTERN INDIANA. MODEL
STILL DO NOT SHOW MUCH DEEP MOISTURE WITH THE SYSTEM. HOWEVER...4KM
HI-RES WRF NMM AND HRRR RUNS HAVE BEEN CONSISTENT SHOWING A 3-6 HOUR
WINDOW OF SNOW SHOWERS MOVING THROUGH DURING THE EVENING. HAVE
INCREASED POPS TO LIKELY DURING THE EVENING HOURS NORTHWEST OF THE
RIDGES...ALTHOUGH FEEL PRETTY CONFIDENT THAT ACCUMULATION WILL
REMAIN LESS THAN HALF AN INCH. AS ALWAYS...RIDGES AND LOCATIONS OF
I-80 WILL RECEIVE SLIGHTLY MORE ACCUMULATION. THINK THAT MOST
SNOWFALL SHOULD BE OUT OF THE REGION BY SUNRISE SATURDAY...WITH
ISOLATED SNOW SHOWERS REMAINING ACROSS THE RIDGES AS THE COLD FRONT
COMPLETES ITS PASSAGE ACROSS THE REGION. COLD AIR BEHIND THE FRONT
WILL RESULT IN THE COLDEST HIGH TEMPERATURES SO FAR THIS
SEASON...WITH MOST LOCATIONS REMAINING BELOW FREEZING ALL DAY.

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
WEATHER WILL BE VERY QUIET DURING THIS PORTION OF THE FORECAST. HIGH
PRESSURE WILL REMAIN IN CONTROL OVER THE EAST COAST...AND
SOUTHWESTERLY WINDS WILL PREVENT ANY LAKE EFFECT OR UPSLOPE SHOWERS
FROM OCCURRING. OVERNIGHT LOWS WILL BE THE COLDEST OF THE
SEASON...WITH ALL LOCATIONS DROPPING IN THE TEENS. IF ENOUGH
RADIATIONAL COOLING OCCURS ALONG THE SNOWPACK IN THE RIDGES...TEMPS
HERE COULD REACH THE SINGLE DIGITS. TEMPERATURES WILL MODERATE
DURING THE PERIOD...WITH A RETURN TO NORMAL HIGHS BY MONDAY.

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
PER HPC GUIDANCE, FAVORED RECENT ECMWF MODEL OUTPUT WITH SOME NAEFS
INFLUENCE. THESE MODEL SOLUTIONS MAINTAINED THE IDEA THAT THE UPPER
LEVEL JETSTREAM ACROSS THE U.S. WILL BECOME MORE ZONAL DURING THE
COMING WEEK. HENCE TEMPERATURES SHOULD BE NEAR SEASONABLE LEVELS
THIS PERIOD, WHICH IS ALSO SUPPORTED BY GFS MOS.

HIGH PRESSURE WILL PROVIDE DRY CONDITIONS INTO TUESDAY. A COLD
FRONTAL PASSAGE MAY PROVIDE SOME SNOW AND RAIN SHOWERS TUESDAY
NIGHT AND WEDNESDAY. A BETTER DEVELOPED LOW PRESSURE SYSTEM MAY
PROVIDE A SECOND BOUT OF SNOW AND RAIN SHOWERS THURSDAY INTO
POSSIBLY EARLY FRIDAY. NAEFS MODEL OUTPUT SUGGESTS SOME INJECTION
OF NORTHWEST FLOW ENERGY NEXT WEEKEND WHICH WOULD RESULT IN COLDER
TEMPERATURES NEXT WEEKEND.

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
RECENT SURFACE, SATELLITE, AND RADAR DATA, ALONG WITH RECENT HRRR
AND NAM MODEL OUTPUT, SHOW A COLD FRONTAL PASSAGE THIS EVENING THAT
WILL RESULT IN FLIGHT CONDITIONS QUICKLY DETERIORATING TO MAINLY
MVFR WITH SNOW SHOWERS. BRIEF IFR CONDITIONS ARE POSSIBLE,
PARTICULARLY NORTH, WITHIN THE I-80 CORRIDOR, AT TAF SITES SUCH AS
KFKL AND KDUJ.

BY 06Z FOR TAF SITES SOUTH OF THE I-80 CORRIDOR, SNOW SHOWERS WILL
DISSIPATE, AND LINGERING STRATOCUMULUS CEILINGS WILL LIFT TO VFR
LEVELS. WITHIN THE I-80 CORRIDOR, COLD WESTERLY WINDS CAN INDUCE
SOME LAKE EFFECT SNOW SHOWERS WHICH CAN CAUSE MVFR STRATOCUMULUS
AND BANDS OF SCATTERED IFR SNOW SHOWERS TO LINGER INTO SATURDAY
MORNING.

OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
VFR INTO TUESDAY. COLD FRONTAL SHOWERS OF SNOW AND RAIN CAN CAUSE
RESTRICTIONS TUESDAY NIGHT INTO WEDNESDAY.

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

AREA FORECAST DISCUSSION

NWS NORTH PLATTE NE

1212 PM CST FRI DEC 9 2011

.AVIATION...
SURFACE HIGH PRESSURE CONTINUES TO DRIFT ACROSS THE CENTRAL PLAINS
TODAY. THIS WILL CAUSE WINDS TO BE LIGHT AND VARIABLE. AS THE HIGH
SHIFTS SOUTH OVERNIGHT...LIGHT SOUTHERLY WINDS ARE EXPECTED TO
DEVELOP. AS FOR SKIES...CLOUDS WILL DIMINISH...BECOMING CLEAR OR A
FEW HIGH CLOUDS OVERNIGHT. SOME CONCERN THAT SOME MVFR OR IFR FOG
WILL DEVELOP OVER SOUTHWEST INTO CENTRAL NEBRASKA IN THE MORNING.
NO MOS GUIDANCE SUPPORTS DEVELOPMENT...HOWEVER DUE TO THE RECENT
SNOW AND SOME SUN TO MELT PART OF THE SNOW TODAY ALONG WITH LITTLE
WIND TO MIX THE BL...COULD SEE SOME DEVELOPMENT. THIS WILL NEED TO
BE MONITORED CLOSELY.

.PREV DISCUSSION... /ISSUED 349 AM CST THU DEC 8 2011/

DISCUSSION...

.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&

SHORT TERM/EXTENDED...99
AVIATION...MASEK

AREA FORECAST DISCUSSION

NWS BUFFALO NY

1222 PM EST FRI DEC 9 2011

NO CHANGES FOR AREAS EAST OF LAKE ONTARIO.

FOR SPECIFIC SNOWFALL TOTALS...PLEASE SEE BUFWSWBUF OR THE LATEST
GRAPHICS ON OUR WEB PAGE AT WWW.WEATHER.GOV/BUFFALO.

THIS SHORTWAVE WILL CROSS THE REGION TUESDAY NIGHT...BUT WITH
LIMITED MOISTURE TO WORK WITH IN THE LOW LEVELS...WE SHOULD ONLY
EXPERIENCE NUISANCE MIXED PRECIPITATION.

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AT 18Z...THE SURFACE MAP SHOWS A COLD FRONT PUSHING ACROSS CENTRAL
LAKE ERIE WITH AN AREA OF LAKE ENHANCED SNOW FORMING RIGHT AHEAD OF
THE BOUNDARY. THE SNOW IS RESULTING IN IFR CONDITIONS AT KIAG.
EXPECT IFR CONDITIONS TO DEVELOP AT KBUF AS THE SNOW BAND DROPS
SOUTH ACROSS THE NIAGARA FRONTIER...GENERALLY BETWEEN 18Z AND 21Z.
A SIMILAR TREND WILL TAKE PLACE AT KART BETWEEN 20Z AND 00Z.

AREAS NOT IMMEDIATELY DOWNWIND OF THE LAKES...SUCH AS KROC...MAY SEE
CONDITIONS LOWER TO MVFR AT TIMES AS THE FRONT CONTINUES TO PUSH TO
THE EAST.

LATE THIS AFTERNOON AND INTO THE EVENING...THE LAKE SNOWS WILL
SETTLE SLOWLY TO THE SOUTH AS WESTERLY WINDS SETS UP BEHIND THE
FRONT. THIS WILL ALLOW CONDITIONS TO IMPROVE GRADUALLY VCNTY
KIAG/KBUF AND KART...WHILE AT KJHW...CIGS AND VSBYS WILL LOWER TO
IFR AS THE SNOW SETS UP ACROSS THE SOUTHERN TIER.

LAKE SNOWS WILL STILL BE IN PLACE SOUTHEAST OF THE LAKES INTO
SATURDAY MORNING...BUT MOST OF THE TAF SITES NORTH OF THE SOUTHERN
TIER SHOULD BE SEEING VFR CONDITIONS.

OUTLOOK...
SATURDAY NIGHT...MAINLY VFR WITH AREAS OF MVFR IN WEAKENING LAKE
EFFECT SNOW.
SUNDAY THROUGH TUESDAY...VFR.
WEDNESDAY...MAINLY VFR.

SYNOPSIS...LEVAN/THOMAS
NEAR TERM...LEVAN/THOMAS/ZAFF
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...TJP
MARINE...THOMAS

AREA FORECAST DISCUSSION

NWS FORT WORTH TX

1007 AM CST FRI DEC 9 2011

.UPDATE...
EXTENDED THE FOG ADVISORY THROUGH NOON FOR THE REGION ALONG THE
I-35 CORRIDOR SOUTH OF THE METROPLEX THROUGH TEMPLE. OTHERWISE
BAND OF MOISTURE AND LOW CLOUDS WILL BE STUBBORN TODAY AS FRONT
WILL NOT HAVE A LOT OF CLEARING POWER. LOOKS LIKE CLOUDS WILL
PERSIST GENERALLY ALONG AND EAST OF I-35. OBVIOUSLY TEMPERATURES
BENEATH THE CLOUD BANK WILL BE HELD DOWN DUE TO LACK OF SUNSHINE
AND HAVE LOWERED THEM A FEW DEGREES. OTHERWISE...CLOUD BANK LOOKS
LIKE IT WILL MOVE SOUTHWEST DURING THE EVENING HOURS AND
SOUTHERN/SOUTHWESTERN ZONES MAY STAY CLOUDY TONIGHT. WILL RAISE
TONIGHTS LOWS IN THAT AREA. NO OTHER CHANGES AT THIS TIME. TR.92

.AVIATION...
/16Z AMENDMENTS/

LATEST SURFACE DATA INDICATES A WEAK SURFACE LOW PRESSURE SYSTEM
JUST SOUTH OF THE MAJOR AIRPORTS THIS MORNING WHICH IS HELPING TO
KEEP WEAK EASTERLY FLOW IN PLACE. THIS WILL LIKELY KEEP LOW CIGS
IN PLACE FOR SEVERAL MORE HOURS. A COLD FRONT IS ALSO EXPECTED TO
MOVE SOUTH INTO THE AREA LATER TODAY ALTHOUGH LOW LEVEL MOISTURE
WILL LINGER EVEN AS THIS FRONT MOVES THROUGH. LATEST RUC SOUNDINGS
SUPPORT LOWER CIGS THROUGH THE AFTERNOON...ALTHOUGH THERE MAY BE
SOME BRIEF TEMPORARY IMPROVEMENTS. HAVE AMENDED METROPLEX TAFS
ACCORDINGLY AND WILL MONITOR CIG TRENDS FOR FURTHER ADJUSTMENTS IF
NECESSARY.

DUNN

.PREV UPDATE...
.UPDATE...
WARM...MOIST AIR CONTINUES TO ADVECT NORTHWARD CAUSING PATCHY
AREAS OF DENSE FOG TO BECOME MORE WIDESPREAD AS WE APPROACH
SUNRISE. A DENSE FOG ADVISORY WILL BE ISSUED THROUGH 10 AM FOR
CENTRAL AND SOUTHERN COUNTIES WHERE VISIBILITIES ARE RAPIDLY
DETERIORATING. THE ADVISORY AREA EXTENDS FROM THE DALLAS-FORT
WORTH METROPLEX SOUTHWARD ALONG AND SURROUNDING THE INTERSTATE
35/35 W CORRIDOR. THE FOG WILL LIKELY HANG AROUND THROUGH MID
MORNING AND VISIBILITIES SHOULD BEGIN IMPROVING BY 10 AM.

.PREV DISCUSSION... /ISSUED 350 AM CST FRI DEC 9 2011/
LIGHT SOUTH FLOW CONTINUES OVER NORTH TEXAS AND MOISTURE HAS BEGUN
TO RETURN SLOWLY ACROSS THE SOUTHERN HALF OF THE FORECAST AREA
THIS MORNING. DEWPOINTS HAVE STEADILY CREPT UP AND LOW STRATUS HAS
FORMED DURING THE PAST FEW HOURS SOUTH OF THE INTERSTATE 20
CORRIDOR. STRATUS IS SPREADING NORTH AND WILL LIKELY COVER THE
DALLAS-FORT WORTH METROPLEX BEFORE SUNRISE. THERE IS STILL THE
POTENTIAL FOR PATCHY FOG TO FORM BUT WITH THE COMBINATION OF
QUICKLY-DEVELOPING STRATUS AND THICKENING HIGH CLOUDS...THE
PROBABILITY FOR WIDESPREAD LOW VISIBILITIES SEEMS PRETTY SLIM.
WILL CONTINUE WITH THE MENTION OF FOG FOR AREAS GENERALLY SOUTH OF
INTERSTATE 20 WHERE HIGHEST LEVELS OF SHALLOW MOISTURE RESIDE.

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 48 33 50 32 51 / 0 0 0 5 10
WACO, TX 52 38 50 31 48 / 0 0 0 10 20
PARIS, TX 46 29 48 28 50 / 0 0 0 5 5
DENTON, TX 48 29 50 27 49 / 0 0 0 5 10
MCKINNEY, TX 47 29 49 27 50 / 0 0 0 5 10
DALLAS, TX 47 33 50 33 51 / 0 0 0 5 10
TERRELL, TX 47 31 49 29 50 / 0 0 0 5 10
CORSICANA, TX 50 33 51 32 47 / 0 0 0 5 10
TEMPLE, TX 53 38 52 32 50 / 0 0 0 20 20
MINERAL WELLS, TX 51 34 49 28 49 / 0 0 0 10 10

.FWD WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR TXZ133-134-145-146-
158>161-174.

AREA FORECAST DISCUSSION...UPDATED

NWS FORT WORTH TX

1003 AM CST FRI DEC 9 2011

.AVIATION...
/16Z AMENDMENTS/

DUNN

.UPDATE...
WARM...MOIST AIR CONTINUES TO ADVECT NORTHWARD CAUSING PATCHY
AREAS OF DENSE FOG TO BECOME MORE WIDESPREAD AS WE APPROACH
SUNRISE. A DENSE FOG ADVISORY WILL BE ISSUED THROUGH 10 AM FOR
CENTRAL AND SOUTHERN COUNTIES WHERE VISIBILITIES ARE RAPIDLY
DETERIORATING. THE ADVISORY AREA EXTENDS FROM THE DALLAS-FORT
WORTH METROPLEX SOUTHWARD ALONG AND SURROUNDING THE INTERSTATE
35/35 W CORRIDOR. THE FOG WILL LIKELY HANG AROUND THROUGH MID
MORNING AND VISIBILITIES SHOULD BEGIN IMPROVING BY 10 AM.

.FWD WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR TXZ133-134-145-146-
158>161-174.