Forecast Discussions mentioning any of "HRRR" "RR" "RUC13" "RUC" received at GSD on 11/29/11

AREA FORECAST DISCUSSION...UPDATED

NWS CHICAGO/ROMEOVILLE IL

 939 PM CST MON NOV 28 2011

.DISCUSSION...
938 PM CST

THE GOING FORECAST FOR TONIGHT INTO TUESDAY GENERALLY REMAINS ON
TRACK. THE UPPER LOW OVER THE LOWER TO MIDDLE PORTION OF THE
MISSISSIPPI VALLEY IS LOOKING VERY IMPRESSIVE ON WATER VAPOR
IMAGERY TONIGHT...WITH A WELL-DEFINED CLOSED CIRCULATION AND MOIST
CONVEYOR BELT FROM THE EASTERN GULF AND WESTERN ATLANTIC COMING
INTO THE SYSTEM. THE UPPER AIR PROFILES THIS EVENING PAINTED THE
PICTURE WITH THE COLD CORE UPPER LOW /-10C AT 850MB OVER MI/ AND A
VERY WARM AND MOIST NOSE TO THE NORTH /OVER 0C TD AT 700MB IN OH/.
THE WOLCOTT INDIANA WIND PROFILER IS SHOWING INCREASINGLY
EASTERLY WINDS UP TO 600 MB INDICATIVE OF THE SYSTEM TROWAL
DEVELOPMENT. THIS TROWAL AND ASSOCIATED ISENTROPIC OMEGA FROM THE
EAST STILL LOOK TO POINT DIRECTLY INTO NORTHWEST IN AND EASTERN IL
LATE TONIGHT INTO TUESDAY. SO DO EXPECT TO SEE RADAR ECHOES
CONTINUE TO BLOSSOM OVER THAT AREA. THE 29.00 RUC AND NAM CONTINUE
TO TREND EAST WITH THE WESTERN EDGE OF THE RAIN SHIELD...KEEPING
THE TIGHT GRADIENT BETWEEN NOTHING AND APPRECIABLE RAIN ABOUT 50
MILES EAST OF INTERSTATE 55. WILL GO AHEAD AND EASE THE NORTHWEST
SIDE OF THE POPS IN THE FORECAST...BUT OTHERWISE TIMING AND
ORIENTATION LOOK GOOD. PRECIPITATION AMOUNTS IN THE FAR SOUTHEAST
BETWEEN 1.25 AND 2 INCHES ARE PROBABLE. SUCH PREDICTED RAINFALL
AMOUNTS HAVE CAUSED THE FORECAST FOR THE KANKAKEE RIVER AT SHELBY
TO NOW GO ABOVE FLOOD STAGE. OTHER THAN A RIVER FLOOD WARNING FOR
THAT...NO OTHER CHANGES ARE PLANNED TO GOING HEADLINES THIS
EVENING. THE TRANSITION TO A MIX OR ALL SNOW DUE TO DYNAMIC
COOLING LOOKS PROBABLE WHEN THE UPPER LOW/PV ANOMALY ARE AT ITS
CLOSEST POINT DURING THE MID-AFTERNOON TO EARLY EVENING. THE
WINDOW OF TIME FOR PRECIPITATION TO FALL AS SNOW LOOKS SOMEWHAT
SHORTER IN THE NEW GUIDANCE...ENDING AROUND 9 PM TUE NIGHT.
STILL...THAT 4 TO 6 HOUR WINDOW IS ENOUGH TIME GIVEN THE FORCING
FOR HEAVIER RATES TO CAUSE SOME IMPACTS AND POTENTIALLY RESULT IN
MINOR SNOWFALL ACCUMULATIONS IN NORTHWEST IN.

MTF

&&

//PREV DISCUSSION...
335 PM CDT

TONIGHT THROUGH WEDNESDAY NIGHT...

POWERFUL STORM SYSTEM WILL BRING A WIDE VARIETY OF ADVERSE WEATHER
TO ABOUT THE SOUTHEAST HALF OF THE CWA...WHILE THE NORTHWEST AREAS
SIT HIGH AND DRY.

CLASSIC MID-LATITUDE CYCLONE IS IN THE PROCESS OF ORGANIZING OVER
THE SOUTHERN PLAINS THIS AFTERNOON WITH WARM CONVEYOR BELT
EXTENDING FROM THE NORTHWEST CARIBBEAN NORTH INTO THE LOWER OHIO
VALLEY. WATER VAPOR IMAGERY DOES SUGGEST THAT A MID LEVEL
CIRCULATION HAS INDEED CLOSED OFF NEAR MEMPHIS AS HAS BEEN
ADVERTISED BY NUMERICAL GUIDANCE FOR A COUPLE DAYS NOW. GUIDANCE IS
GENERALLY IN PRETTY GOOD AGREEMENT ON THIS SYSTEM LIFTING NORTHEAST
INTO THE OHIO VALLEY ON TUESDAY WITH THE CYCLONE EXPECTED TO
BEGIN DEEPENING AS IT LIFTS NORTH TUESDAY INTO TUESDAY NIGHT.

THREAT 1: HEAVY RAIN/FLOODING
RAIN FROM THE WARM CONVEYOR BELT WILL BEGIN TO OVERSPREAD SOUTHEAST
PORTIONS OF THE CWA BY EARLY THIS EVENING AND CONTINUE AT TIMES
THROUGH THE OVERNIGHT HOURS. SYSTEM IS TAPPING INTO A PRETTY GOOD
FEED OF MOISTURE WITH PWAT VALUES OVER AN INCH (200-225% OF
NORMAL)PROGGED TO MAKE IT INTO OUR SOUTHEAST COUNTIES TONIGHT INTO
TUESDAY MORNING. IN ADDITION TO THE UNSEASONABLY HIGH VALUES OF
MOISTURE ALSO CONCERNED THAT THE DEVELOPING TROWAL/DEFORMATION ZONE
WILL END UP PIVOTING OVER NORTHWEST INDIANA AND POSSIBLY FAR EASTERN
ILLINOIS WHICH WOULD PROLONG THE MODERATE TO OCCASIONALLY HEAVY
RAIN. MODELS GENERALLY IN GOOD AGREEMENT ON AN AXIS OF HEAVY RAIN
WITH TOTALS OF AT LEAST 1-2 INCHES OVER OUR FAR SOUTHEAST CWA...WITH
THE POTENTIAL FOR LOCALLY HEAVIER TOTALS. THESE AREAS PICKED UP
GENERALLY A HALF INCH TO INCH OF RAIN OVER THE WEEKEND AND
CONTINGENCY FORECASTS FROM THE RFC BRING ALL 3 NW INDIANA FORECAST
POINTS ALONG THE KANKAKEE RIVER INTO FLOOD BASED ON HPC QPF. GIVEN
THIS HAVE OPTED TO HOIST A FLOOD WATCH WITH THE THREAT BEING MAINLY
LOW LAND MINOR FLOODING TRANSITIONING TO RIVER FLOODING.

THREAT 2: WIND/LAKESHORE FLOODING
PRESSURE GRADIENT EXPECTED TO REALLY TIGHTEN UP LATE TONIGHT INTO
TUESDAY AS DEEPENING SURFACE LOW TRACKS NNE TO LAKE ERIE WHILE
SURFACE HIGH ATTEMPTS TO PUSH EASTWARD INTO THE CORN BELT. WINDS
LIKELY TO RAMP UP TO 20-30 MPH TUESDAY WITH GUSTS OF 30-40 MPH
LIKELY. THE EXCEPTION WILL BE NEAR LAKE MICHIGAN WHERE THE NEAR
FRICTIONLESS SURFACE AND GREATER LOW LEVEL INSTABILITY DUE TO THE
COLD AIR OVER THE WARMER LAKE WATERS SHOULD ALLOW WINDS TO INCREASE
TO 30-40 MPH WITH GUSTS OVER 50 MPH LIKELY. HAVE ISSUED A WIND
ADVISORY FOR AREAS NEAR THE LAKE AND ACTUALLY WOULDNT EVEN BE ALL
THAT SURPRISED TO SEE WINDS FLIRT WITH HIGH WIND WARNING CRITERIA
(SUSTAINED 40MPH/GUSTS 58MPH) FOR A TIME TUESDAY RIGHT ALONG THE
SHORELINE. THE VERY STRONG NNE WINDS BLOWING DOWN THE FULL FETCH OF
THE LAKE SHOULD ALLOW FOR WAVES TO APPROACH 20FT TUESDAY AFTERNOON
AND EVENING WHICH COULD ONCE AGAIN CAUSE SOME LAKESHORE FLOODING AND
OVERWASH PROBLEMS. WHILE WINDS WILL SUBSIDE TUESDAY EVENING AND BACK
TO MORE NNW THE WAVES WILL BE SLOWER TO RESPOND WITH SOME FLOOD
THREAT POSSIBLY LINGERING INTO WEDNESDAY.

THREAT 3: HEAVY SNOW
MODELS CONTINUE TO SUGGEST THAT THE DEFORMATION BAND WILL SET UP
OVER OUR EASTERN CWA TUESDAY AFTERNOON...WITH ALMOST ANY VERSION OF
THE WRF THAT I COULD FIND SHOWING IT LINGERING INTO THE EVENING
TUESDAY. BOTH GLOBAL MODELS AND MESOSCALE MODELS DEPICT VERY
IMPRESSIVE SET-UP FOR DYNAMIC COOLING AS HEIGHTS BEGIN TO CRASH
TOMORROW AFTERNOON (DROPPING >60M/6 HOUR)...WHICH SHOULD BE GOOD
ENOUGH TO RESULT IN RAIN CHANGING OVER TO WET SNOW EITHER TUESDAY
AFTERNOON OR EARLY TUES EVENING. BEST CHANCE OF THE CHANGE OVER
OCCURRING WILL ACTUALLY BE OVER OUR SE CWA WHERE THE FORCING AND
DYNAMIC COOLING WILL BE MOST INTENSE...WITH AREAS FARTHER
NORTHWEST POSSIBLY REMAINING ALL RAIN. PRESENCE OF 7C/KM H7-5
LAPSE RATES IN THE DRY INTRUSION ACTUALLY COULD SUPPORT SOME
CONVECTIVE ELEMENTS TOMORROW AFTERNOON OVER OUR FAR EASTERN
COUNTIES...WHICH COULD HELP FACILITATE A SWITCH OVER TO SNOW
AND/OR ENHANCE PRECIP RATES.

AM CONCERNED THAT SNOWFALL COULD GET SOMEWHAT OUT OF HAND FOR A TIME
LATER TOMORROW AFTERNOON AND EVENING OVER MAINLY NORTHWEST INDIANA.
SURFACE TEMPS LOOKS TO START OUT ABOVE FREEZING...BUT NOT UNCOMMON
IN SITUATIONS LIKE THIS FOR STRONG DYNAMIC COOLING TO RESULT IN SFC
TEMPS DROPPING TO OR JUST BELOW FREEZING DURING THE BOUTS OF
HEAVIEST PRECIP. SOIL TEMPS STILL IN THE MID 40S...WHICH MAY HELP TO
LESSEN THE ACCUMULATION THREAT SOMEWHAT...THOUGH AS SNOW RATES
INCREASE THE EFFECTS OF WARM SOIL TEMPS DECREASE. THREAT CERTAINLY
EXISTS FOR A SLUSHY SEVERAL INCHES OF SNOW OVER NORTHWEST INDIANA
BUT WITH MARGINAL TEMPS AND WARM GROUND SUSPECT THE PRIMARY TRAVEL
HAZARD WILL END UP BEING GREATLY REDUCED VISBY (POSSIBLY TO 1/4SM OR
LESS) WITH ACCUMS ON ROADWAYS FAIRLY LIMITED AND THUS PROBABLY NOT
NECESSITATING A WINTER WEATHER ADVISORY.

IT WILL TRULY BE A TALE OF TWO CITIES BETWEEN ROCKFORD AND
VALPARAISO TUESDAY...WITH A MODIFIED MORE SUBDUED VERSION OF
ARMAGEDDON TAKING PLACE OVER SOUTHEAST CWA WHILE AREAS OF NORTH
CENTRAL ILLINOIS ARE JUST CLOUDY BREEZY AND COOL! STORM RAPIDLY
DEPARTS LATE TUESDAY NIGHT INTO WEDNESDAY WITH RAPIDLY IMPROVING
CONDITIONS. THIS STORM WILL BE MANUFACTURING ITS OWN COLD AIR VIA
DYNAMIC PROCESSES TOMORROW...SO WITH NO GOOD PUSH OF COLD AIR IN ITS
WAKE AND IN FACT WARM AIR ADVECTION KICKING IN WE SHOULD SEE TEMPS
REBOUND TO NEAR IF NOT EVER SO SLIGHTLY ABOVE AVERAGE AGAIN BY
WEDNESDAY.

IZZI

LONG TERM THURSDAY THROUGH MONDAY...

A COUPLE TIME FRAMES OF INTEREST DURING THE LATTER
PORTION OF THIS WEEK INTO NEXT...PARTICULARLY CENTERED ON THIS
WEEKEND. FIRST...A CLIPPER-LIKE SYSTEM IS EXPECTED TO PROGRESS EAST
THROUGH THE GREAT LAKES ON THURSDAY NIGHT SWINGING A CANADIAN COLD
FRONT THROUGH THE REGION. THIS FRONT IS CHARACTERIZED IN MODEL
SOLUTIONS AS HAVING LITTLE MOISTURE RETURN FLOW AHEAD OF IT WITH
MOST OF ITS ADVECTION BEING COLD AIR BEHIND IT. PRECIPITATION WITH
THESE TYPE OF FRONTS TENDS TO BE LIGHT AND OFTEN RIGHT ALONG OR JUST
BEHIND THE FRONT. SUCH IS WHAT THE 28.12 GFS AND EC ARE DEPICTING
AND HAVE GENERALLY GONE WITH A BLEND OF THESE AND THE INHERITED
FORECAST...WITH BETTER FORCING JUST NORTH OF THE AREA. THIS LOOKS TO
BE SNOW SHOWERS IF PRECIPITATION CAN MATERIALIZE. IN THE WAKE OF
THIS FRONT LATE THURSDAY NIGHT INTO FRIDAY...THERE LIKELY WILL BE A
CORRIDOR OF LAKE-ENHANCED CLOUDS AND POTENTIALLY SNOW SHOWERS
INTO NORTHWEST IN.

ATTENTION THEN TURNS TO A CLOSED UPPER LOW IN THE SOUTHWEST WHICH
BEGINS TO PHASE INTO A PROGRESSIVE NORTHERN STREAM TROUGH ON
SATURDAY. THE THERMAL BOUNDARY FROM OUR OLD FRONT ON THURSDAY NIGHT
BEGINS TO LIFT NORTHWARD IN ADVANCE OF THE SYSTEM...WITH LARGE MODEL
DISAGREEMENT ON WHERE THIS STALLS AND HOW QUICKLY THE SYSTEM
TRANSLATES ALONG IT. WHAT IS INTRIGUING ABOUT THIS IS THE 28.12
GFS...EC...AND GEFS ALL SHOW A PERIOD OF APPROXIMATELY 18 TO 24
HOURS OF WARM AIR ADVECTION AND AT TIMES WHAT APPEARS TO BE
FRONTOGENETIC ENHANCED PRECIPITATION FOR SOMEWHERE IN THE REGION.
ABOUT 40 PERCENT OF THE GEFS MEMBERS PROVIDE ORD AT LEAST ONE
QUARTER OF AN INCH OF PRECIPITATION DURING THAT TIME. THE EC ALSO IS
FURTHER NORTH AND WARM ENOUGH IN THICKNESSES AND LOW-LEVEL
TEMPERATURES TO SUPPORT MAINLY RAIN THROUGH SATURDAY NIGHT IN THE
IMMEDIATE REGION...WHILE THE GFS POINTS MORE TOWARDS A MIX OR
POSSIBLY EVEN MAINLY SNOW. OBVIOUSLY OVER FIVE DAYS OUT...A LOT OF
UNCERTAINTY WHICH WILL LIKELY CONTINUE FOR AT LEAST A DAY OR TWO
MORE...BUT SOMETHING TO KEEP OUR EYES ON. HAVE CONTINUED THE TREND
TO INCREASE POPS CENTERED ON SATURDAY NIGHT BASED ON A MODEL BLEND
TO THE INHERITED FORECAST. TEMPERATURES THEN ARE FAVORED TO DROP
BELOW NORMAL TO AT LEAST START THE FIRST FULL WEEK OF DECEMBER.

MTF


.AVIATION...

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

 * MVFR CIGS PERSISTING THROUGH THE EVENING
 * NORTHEAST WIND INCREASING OVERNIGHT...WITH STRONG GUSTS TOMORROW
 * RAIN DEVELOPING TONIGHT MAINLY SOUTHEAST OF ORD

SHEA

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

DEEPENING LOW PRESSURE SYSTEM ACROSS THE TENNESSEE VALLEY WILL
CONTINUE TO LIFT NORTH AND INTO THE OHIO VALLEY THIS EVENING.
IMPACT TO THE TERMINALS WILL TAKE PLACE OVERNIGHT...WITH RAIN
BEGINNING TO OVERSPREAD GYY BEYOND 05Z TONIGHT...AND LATER MOVING
ACROSS MDW. ORD AND DPA ARE WILDCARDS AS TO HOW LIKELY IT WILL
RAIN LATE TONIGHT AND INTO TOMORROW MORNING...VS JUST BEING IN THE
VC TO THE SOUTH AND EAST. PRESENT THINKING IS THAT THERE SHOULD BE
A WELL DEFINED LINE BETWEEN PRECIP AND NO PRECIP...AND THAT ORD
MAY STAY ON THE NO PRECIP SIDE. CONDITIONS WILL BE WORSE FOR MDW
AND WORSE YET FOR GYY. THAT SAID...WINDS WILL PICK UP TOMORROW FOR
ALL OF THE TERMINALS AND INCREASE TO A SUSTAINED 20+ KT RANGE AND
GUST INTO THE MIDDLE 30 KT RANGE. CIG TRENDS MAY BE A LITTLE
TRICKY WHERE THERE IS NO PRECIP FALLING...AS A WELL MIXED BOUNDARY
LAYER SHOULD KEEP CIGS FROM COMPLETELY TANKING...BUT THEY WILL
EASILY FALL TO LOW END MVFR AND POTENTIALLY IFR FOR LOCATIONS THAT
SEE RAIN /E.G. MDW AND GYY/.

SHEA

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

 * MODERATE CONFIDENCE IN CIG TREND
 * HIGH CONFIDENCE IN WIND FORECAST...MOD/HIGH IN GUST FORECAST
 * LOW CONFIDENCE IN PRECIPITATION TIMING / COVERAGE LATE TONIGHT
   INTO TUESDAY

SHEA

//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...

 * WEDNESDAY...VFR.
 * THURSDAY...VFR. CHC LGT SN IN THE EVENING.
 * FRIDAY...CHC SHSN IN THE MORNING.
 * SATURDAY...VFR.
 * SUNDAY...CHC RA/SN. MVFR POSSIBLE.

SHEA

&&

.MARINE...
255 PM CST

A SURFACE RIDGE AXIS EXTENDS ACROSS THE MIDDLE OF LAKE MICHIGAN
WITH SOUTHWEST WINDS OVER THE NORTHERN PORTIONS OF THE LAKE AND
NORTHEAST WINDS OVER THE SOUTH. DEEPENING LOW PRESSURE OVER
EASTERN TENNESSEE AND KENTUCKY WILL TRACK NORTHWARD THIS
EVENING...FORCING THE RIDGE AXIS TO THE NORTH AND STRENGTHENING
THE PRESSURE GRADIENT OVER LAKE MICHIGAN. WINDS WILL QUICKLY
STRENGTHEN THROUGH THE EVENING AND OVERNIGHT WILL GALE FORCE WINDS
DEVELOPING BY THE EARLY MORNING HOURS. GALES SHOULD INITIALLY DEVELOP
OVER THE FAR SOUTHERN PORTIONS OF THE LAKE...INCLUDING THE
NEARSHORE AND OFFSHORE WATERS...BUT THE GALES SHOULD RAPIDLY
SPREAD NORTH...ENGULFING ALL OF THE LAKE BY DAYBREAK. HIGHER END
GALES SHOULD DEVELOP BY MIDDAY AS THE SFC LOW MOVES OVER THE
EASTERN GREAT LAKES...WITH OCCASIONAL STORM FORCE GUSTS TO 50KT
POSSIBLE OVER THE SOUTHERN 2/3RDS OF THE LAKE. GALES SHOULD BEGIN
TO WIND DOWN WEDNESDAY MORNING AS THE SURFACE LOW MOVES INTO
QUEBEC AND A WEAK RIDGE CROSSES THE UPPER MISSISSIPPI VALLEY AND
INTO THE WESTERN GREAT LAKES REGION.

WHILE THE GALES SHOULD SUBSIDE WEDNESDAY MORNING...HIGH WAVES
HAZARDOUS TO SMALL CRAFT WILL LIKELY PERSIST THROUGH WEDNESDAY
NIGHT.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ006-ILZ014...6 AM TUESDAY TO 9 PM TUESDAY.

     LAKESHORE FLOOD ADVISORY...ILZ006-ILZ014...6 AM TUESDAY TO 10 AM
     WEDNESDAY.

     FLOOD WATCH...ILZ033...MIDNIGHT TUESDAY TO 9 PM TUESDAY.

IN...FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...MIDNIGHT
     TUESDAY TO 9 PM TUESDAY.

     LAKESHORE FLOOD ADVISORY...INZ001-INZ002...6 AM TUESDAY TO 3 PM
     WEDNESDAY.

     WIND ADVISORY...INZ001-INZ002...6 AM TUESDAY TO 9 PM TUESDAY.

LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
     LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
     LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
     LMZ874-LMZ876-LMZ878...3 AM TUESDAY TO 9 AM WEDNESDAY.

     SMALL CRAFT ADVISORY...NEARSHORE WATERS
     UNTIL 3 AM TUESDAY.

&&

$$







AREA FORECAST DISCUSSION

NWS DES MOINES IA

 315 PM CST SUN NOV 27 2011

.SHORT TERM /TONIGHT/...
PRIMARY CONCERN REMAINS LOW CLOUD TRENDS.  MODELS HAVE HAD A POOR
TIME INITIALIZING AND RESOLVING STRATUS...BUT LATEST RUC SEEMS TO
HAVE THE BEST HANDLE ON THINGS BEING MORE PERSISTENT.  THIS
GENERALLY AGREES WITH EXTRAPOLATION NUDGING CLEARING LINE SLOWLY
EASTWARD INTO CENTRAL IA TOWARD MIDNIGHT AND SUGGESTING CLEARING TO
OUR ERN FORECAST AREA BY MORNING BASED ON FURTHER EXTRAPOLATION.
LOW CONFIDENCE IN THESE TRENDS WILL ALSO SPILL OVER INTO MIN TEMPS.
HAVE GENERALLY FOLLOWED GUIDANCE WEST WHERE AIRMASS IS ADEQUATELY
REPRESENTED BY MODELS.  HOWEVER NUDGED TEMPS UP ABOVE EVEN THE
WARMEST GUIDANCE EAST WHERE PROLONGED CLOUD COVER IS ANTICIPATED.
CLEARING PROGRESSION WILL MAKE ALL THE DIFFERENCE...SO EXPECT
CONSIDERABLE GRADIENT IN MIN TEMPS.

.LONG TERM /TONIGHT THROUGH SUNDAY/...
FAIRLY BENIGN MID/LONG RANGE WITH LITTLE IN THE WAY OF PRECIPITATION
CHANCES UNTIL THE NEXT WEEKEND. NEXT WEATHER SYSTEM TO IMPACT IOWA
WILL BE A POSITIVELY TILTED SHORTWAVE MOVING ONSHORE IN THE PACIFIC
NORTHWEST AT THIS TIME.  THE BRUNT OF THE SHORTWAVE ENERGY
ASSOCIATED WITH THE WAVE WILL PASS TO THE EAST WELL NORTH OF IOWA.
THE SOUTHERN PART OF THE SHORTWAVE SHOULD MERGE WITH LARGE UPPER LOW
OVER THE OHIO VALLEY BY 18Z TUESDAY.  THE COLD FRONT ASSOCIATED WITH
THE SHORTWAVE SHOULD CROSS IOWA MONDAY NIGHT.  ONLY LIMITED FORCING
AND MOISTURE SHOULD KEEP THE SENSIBLE WEATHER IMPACT LIMITED TO
INCREASED WINDS...CLOUDS AND MODEST COOLING BUT NO PRECIPITATION.
ON MONDAY...THERE SHOULD BE VERY LITTLE BOUNDARY LAYER FLOW WITH THE
CENTER OF A WEAK SURFACE HIGH PRESSURE SYSTEM IN THE AREA.  MODEL
SOUNDINGS SHOW A VERY STRONG INVERSION WITH MINIMAL MIXING.
THEREFORE...EXPECT COOL TEMPERATURES WITH LIGHT SURFACE WINDS.

FOR THURSDAY AND BEYOND INTO NEXT WEEKEND...THE GFS AND ECMWF ONCE
AGAIN DIVERGE IN THEIR SOLUTIONS OF THE WEATHER OVER THE UPPER
MIDWEST.  THE ECMWF LIFTS OUT AND WEAKENS THE SOUTHWEST UNITED
STATES UPPER LOW INTO THE PLAINS BY NEXT SATURDAY EVENING.  THIS
WILL BRING THE NEXT CHANCE OF PRECIPITATION TO IOWA.  IT IS FAR TO
EARLY TO DETERMINE THE EXTENT OF THE PRECIPITATION CHANCES OR THE
PRECIPITATION TYPE.  FOR NOW...INTRODUCED SMALL POPS SATURDAY NIGHT
INTO SUNDAY.

&&

.AVIATION...27/18Z
PRIMARY CONCERN IN THIS PERIOD WILL BE STRATUS TRENDS.  ALTHOUGH THE
RUC IS DOING BETTER...NAM/GFS INITIALIZED THIS LOW LEVEL MOISTURE
POORLY AND WERE TOO AGGRESSIVE ON THE CLEARING.  THE STRATUS HAS
MOVED LITTLE THIS MORNING SO HAVE PROLONGED THE SLOW CLEARING UNTIL
THIS EVENING...23Z-07Z WEST-EAST.  17Z SURFACE ANALYSIS PLACES RIDGE
FROM NEBRASKA TO ND/MN BORDER.  CLEARING SKIES MAY ALSO LEAD TO FOG
DEVELOPMENT OVERNIGHT AS RIDGE SETTLES IN BEHIND EXITING LOW
CLOUDS.  ALTHOUGH LOWER CONDITIONS ARE POSSIBLE...CONFIDENCE IN
THESE TRENDS HAS LEAD TO NO MORE THAN MVFR VSBYS FOR THE TIME BEING.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM/AVIATION...SMALL
LONG TERM...JOHNSON









AREA FORECAST DISCUSSION

NWS DES MOINES IA

 1130 PM CST SAT NOV 26 2011

.UPDATE 27/06Z AVIATION DISCUSSION...

.SHORT TERM /TONIGHT/...
WIND ADVISORY DROPPED AT 9 PM...BUT WINDS WILL REMAIN BRISK
OVERNIGHT. CLOUDS TO HOLD ON AS WELL. RAISED MINS A BIT OVER THE
REGION WITH CLOUDS AND MIXING HOLDING ON.

.PREVIOUS SHORT TERM /TONIGHT/...
MAIN CONCERN TONIGHT WILL BE TEMP AND WIND TRENDS...AND PRECIP TO A
LESSER EXTENT.  PRIMARY PRECIP SHIELD ASSOCIATED WITH CENTRAL CONUS
LONG WAVE TROUGH CURRENTLY EXTENDS FROM SRN PLAINS INTO GREAT LAKES
AND HAS ALL BUT EXITED FORECAST AREA.  FORCING WITH THIS IS MAINLY
MID/UPPER LEVEL BASED IN THE FORM OF DPVA AND RIGHT ENTRANCE REGION
DIVERGENCE OF GREAT LAKES JET SEGMENT.  RADAR AND SATELLITE TRENDS
DO NOT LOOK PROMISING FOR ADDITIONAL PRECIP THIS EVENING...HOWEVER
MODELS DO SUSTAIN SOME MID LEVEL KINEMATIC FORCING WITH BRIEF SURGE
OF DEEPER MOISTURE SWINGING THROUGH AROUND 00Z OR SHORTLY
THEREAFTER.  THUS HAVE KEPT MENTION OF SPRINKLES OR FLURRIES NE
THIRD DURING THE EVENING.

POTENTIAL FOR ADVISORY LEVEL WINDS HAS DECREASED AS WELL...BOTH
SPATIALLY AND TEMPORALLY...WITH ONLY A SITE OR TWO WEST CURRENTLY
VERIFYING.  ISALLOBARIC MAX...MAX MSLP GRADIENT...AND MAGNITUDE OF
MIXED LAYER WINDS ALL DECREASE THIS EVENING AS THEY APPROACH THE MO
RIVER SO DO NOT EXPECT ADVISORY CRITERIA WINDS TO CONTINUE AS LONG
OR AS FAR EAST AS PREVIOUSLY ANTICIPATED.  THUS HEADLINE NOW ENDS AT
03Z WITH SEVERAL TIERS OF ERN COUNTIES REMOVED.

OUTSIDE OF THE RUC...RAW MODEL TEMPS ARE BEHIND THE CURVE IN TERMS
OF COOLING.  HOWEVER EVEN THE COOLER NAM WHICH EVENTUALLY CATCHES UP
TO THE RUC SUGGESTS CLOUDS AND WINDS KEEPING TEMPS ABOVE GUIDANCE.


.LONG TERM /SUNDAY THROUGH SATURDAY/...
IN THE LONG TERM...IT WILL BE FAIRLY QUIET WITH A DRY FORECAST
THROUGH DAY SEVEN. UPPER LEVEL LOW PRESSURE SYSTEM FORECAST BY ALL
MODELS OVER THE SOUTHEAST UNITED STATES HEADS NORTH INTO THE OHIO
VALLEY BY TUESDAY.  MEANWHILE...A WEAK NORTHERN STREAM SHORTWAVE
SHOULD CROSS THE NORTHERN PLAINS AND UPPER MIDWEST. UPSTREAM QG
FORCING OVER THE NORTHERN PLAINS SHOULD WEAKEN AS THE WAVE
APPROACHES THE MISSISSIPPI VALLEY AND INTERACTS WITH UPPER LOW
MOVING NORTH INTO THE OHIO VALLEY. THE LACK OF SUSTAINED VERTICAL
MOTION AND LIMITED MOISTURE SHOULD KEEP THE ASSOCIATED COLD FRONT
DRY WITH SOME CLOUDS AS IT CROSSES IOWA.  ON MONDAY...AHEAD OF THE
FRONT...WEAK HIGH PRESSURE OVER CENTRAL IOWA BETWEEN THE SYSTEM OVER
THE OHIO VALLEY AND THE APPROACHING COLD FRONT.  ONLY MODEST MIXING
SHOULD KEEP TEMPERATURES RELATIVELY COOL CONSIDERING THE THERMAL
CHARACTERISTICS OF THE AIRMASS. GIVEN THE EXPECTED COOL TEMPERATURES
ON MONDAY...ONLY MODEST COOLING IS FORECAST BEHIND THE FRONT ON
TUESDAY. THIS IS PROBABLY DUE TO BETTER MIXING EVEN THOUGH THE
AIRMASS WILL BE COOLER.

MODELS AGREE IN DIGGING AN UPPER LOW OVER THE SOUTHWEST UNITED
STATES DURING THE EXTENDED.  THE 12Z ECMWF/GFS SUGGEST NORTHWEST
FLOW OVER THE NORTH CENTRAL UNITED STATES BUT THEY HAVE TIMING
DIFFERENCES WITH SHORTWAVES AND FRONTAL PASSAGES LATE NEXT WEEK.
ALTHOUGH ALL SOLUTIONS LOOK MAINLY DRY FOR CENTRAL IOWA...DAY TO DAY
TEMPERATURE FORECASTS HAVE ONLY MODEST CONFIDENCE AT THIS POINT.

&&

.AVIATION...27/06Z
MAIN FOCUS ON STRATUS AND WINDS OVERNIGHT. WINDS WILL REMAIN BRISK
WITH NW 20 TO 30 GUST 40 MPH AT TIMES. STRATUS IN THE MVFR CATEGORY
WITH EASTERN AREAS SEEING CIGS JUST AT OR UNDER 2000` AT TIMES
THROUGH 12Z. EXPECT PBL CLOUDS TO LIFT AFT 15Z SUNDAY WITH SCT-BKN
GIVING WAY TO VFR CIGS AFT 16-19Z EAST. WINDS TO RELAX AND REMAIN
LIGHT FROM 00Z THROUGH END OF FORECAST PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE

&&

$$

SHORT TERM...SMALL/REV
LONG TERM...JOHNSON
AVIATION...REV


















AREA FORECAST DISCUSSION

NWS GOODLAND KS

 1007 AM MST SUN NOV 27 2011

.SHORT TERM (TODAY-TUESDAY)...
220 AM MST SUN NOV 27 2011

EARLY MORNING WV IMAGERY AND RUC H5 ANALYSIS SHOW UPPER LEVEL
PATTERN DOMINATED BY HIGHLY AMPLIFIED RIDGE-TROUGH PATTERN. H5
RIDGE CURRENTLY CENTERED OFF SOUTHERN CALIFORNIA COAST...WITH AXIS
EXTENDING NORTH TO SASKATCHEWAN CANADA. TROUGH AXIS CURRENTLY
EXTENDS FROM WESTERN GREAT LAKES REGION TO SOUTHERN TEXAS. BETWEEN
THESE FEATURES NORTHERLY FLOW AND LARGE SCALE SUBSIDENCE IS IN
PLACES ACROSS PLAINS.

H5 RIDGE WILL DOMINATE PATTERN OVER CWA THROUGH MON...WITH MILD
TEMPS AND DRY CONDITIONS EXPECTED. SHORTWAVE TROUGH PASSES OVER
CWA MONDAY NIGHT...WITH ASSOCIATED COLD FRONT MOVING THROUGH
DURING 18-00Z TIME PERIOD. SHOULD SEE DECENT WARMING AHEAD OF
FRONTAL PASSAGE WITH HIGHS WARMING TO NEAR 60 OVER MOST OF CWA
MIDDAY MONDAY...AND TO MID 60S ACROSS SOUTHERN EXTENT OF CWA.
WHILE GUIDANCE SHOWS TD VALUES INCREASING AHEAD OF FROPA TO LOW
20S...RH VALUES NEAR 18-20% STILL FORECAST ACROSS SOUTHERN PART OF
CWA. WITH GUSTY WINDS DEVELOPING DURING THE AFTERNOON...COULD SEE
A BRIEF WINDOW OF OVERLAP OF NEAR RED FLAG CONDITIONS BEFORE RH
VALUES INCREASE. LOOKS MARGINAL...SO NOT PLANNING ANY HIGHLIGHTS
THIS FORECAST CYCLE.

COULDNT RULE OUT A FEW SPRINKLES/FLURRIES DURING A BRIEF WINDOW
MONDAY NIGHT. HOWEVER...DUE TO THE PROGRESSIVE NATURE OF THIS WAVE
SUBSIDENCE WILL BE QUICK TO BUILD BACK OVER CWA...AND LARGE SCALE
ASCENT IS SOUTHEAST OF CWA BY TIME GUIDANCE SHOWS MID LEVELS
SATURATING. WILL KEEP MENTION OUT OF FORECAST FOR NOW.

SHORTWAVE RIDGING QUICKLY BUILDS BACK OVER CWA BEHIND DEPARTING
TROUGH...WITH DRY CONDITIONS AND SEASONAL TEMPS IN THE MID-UPPER
40S ON TUESDAY.

DR

.LONG TERM (WEDNESDAY-SATURDAY)...
220 AM MST SUN NOV 27 2011

THE UPPER LEVEL RIDGE WILL REMAIN OVER THE CWA WEDNESDAY BEFORE THE
UPPER LEVEL FLOW TRANSITIONS TO MORE OF A SPLIT FLOW PATTERN
THURSDAY THROUGH SATURDAY...WITH A CLOSED LOW OVER THE WESTERN CONUS
AND AN UPPER LEVEL TROUGH OVER THE NORTH AND NORTHEAST CONUS.
MODELS ARE COMING INTO BETTER AGREEMENT WITH THE SPLIT FLOW PATTERN
AND THE FRONTAL TIMING FOR THURSDAY.  CURRENTLY THE STRONG COLD
FRONT LOOKS TO MOVE THROUGH DURING THE OVERNIGHT OR EARLY MORNING
HOURS.  MODELS CONTINUE TO SHOW PRECIP. AND WINDY CONDITIONS BEHIND
THE FRONT THURSDAY.  HOWEVER MOST OF THE PRECIP. AND FORCING IS
DEPICTED WEST OF THE CWA.

FROM FRIDAY THROUGH THE WEEKEND THE MODELS ARE MUCH LESS
CONFIDENT WITH THE UPPER LEVEL FLOW.  GENERALLY THE CLOSED LOW OVER
THE SOUTHWEST CONUS MERGES WITH AN UPPER LEVEL TROUGH THAT MOVES
DOWN FROM CANADA DURING THE WEEKEND.  THE PLACEMENT OF THE UPPER
LEVEL FEATURES ONCE THE CLOSED LOW IS ABSORBED INTO THE MAIN FLOW IS
STILL IN QUESTION.  GENERALLY THE CLOSED LOW WILL MERGE WITH THE
MAIN FLOW OVER THE WESTERN HIGH PLAINS...PLACING AN UPPER LEVEL
TROUGH OVER THE CENTRAL CONUS. AHEAD OF THE UPPER LEVEL TROUGH
ANOTHER COLD FRONT WILL MOVE THROUGH THE CWA. NOT TOO CONFIDENT
WITH PRECIP. CHANCES BEHIND THE FRONT AS THIS WILL DEPEND ON
WHETHER THE UPPER LEVEL FLOW WILL MERGE BEFORE MOVING OVER THE CWA
SENDING MOISTURE OUR WAY...OR REMAIN SPLIT WHICH WOULD SEND THE
MOISTURE TO OUR NORTH AND SOUTH.

TEMPERATURES THROUGH THE PERIOD WILL BE WARMEST ON WEDNESDAY BEFORE
THE COLD FRONT MOVES THROUGH.  THROUGH THE REST OF THE WEEK
TEMPERATURES WILL BE ROUGHLY 10 DEGREES BELOW NORMAL AS THE COLD AIR
REMAINS OVER THE CWA. A BRIEF WARM UP WILL OCCUR SATURDAY...WITH
NEAR NORMAL TEMPERATURES BEFORE THE NEXT COLD FRONT MOVES
THROUGH.

JTL
&&

.AVIATION...
1007 AM MST SUN NOV 27 2011

FOR THE 18Z TAFS...VFR THROUGH THE PERIOD. WINDS WILL BE LIGHT AND
FROM THE WEST/NORTHWEST AS HIGH PRESSURE BUILDS IN. A FEW HIGH
CLOUDS CAN BE EXPECTED...ESPECIALLY LATER IN THE PERIOD.

BAS
&&

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

$$








AREA FORECAST DISCUSSION

NWS GOODLAND KS

 530 AM MST SUN NOV 27 2011

.SHORT TERM (TODAY-TUESDAY)...
220 AM MST SUN NOV 27 2011

EARLY MORNING WV IMAGERY AND RUC H5 ANALYSIS SHOW UPPER LEVEL
PATTERN DOMINATED BY HIGHLY AMPLIFIED RIDGE-TROUGH PATTERN. H5
RIDGE CURRENTLY CENTERED OFF SOUTHERN CALIFORNIA COAST...WITH AXIS
EXTENDING NORTH TO SASKATCHEWAN CANADA. TROUGH AXIS CURRENTLY
EXTENDS FROM WESTERN GREAT LAKES REGION TO SOUTHERN TEXAS. BETWEEN
THESE FEATURES NORTHERLY FLOW AND LARGE SCALE SUBSIDENCE IS IN
PLACES ACROSS PLAINS.

H5 RIDGE WILL DOMINATE PATTERN OVER CWA THROUGH MON...WITH MILD
TEMPS AND DRY CONDITIONS EXPECTED. SHORTWAVE TROUGH PASSES OVER
CWA MONDAY NIGHT...WITH ASSOCIATED COLD FRONT MOVING THROUGH
DURING 18-00Z TIME PERIOD. SHOULD SEE DECENT WARMING AHEAD OF
FRONTAL PASSAGE WITH HIGHS WARMING TO NEAR 60 OVER MOST OF CWA
MIDDAY MONDAY...AND TO MID 60S ACROSS SOUTHERN EXTENT OF CWA.
WHILE GUIDANCE SHOWS TD VALUES INCREASING AHEAD OF FROPA TO LOW
20S...RH VALUES NEAR 18-20% STILL FORECAST ACROSS SOUTHERN PART OF
CWA. WITH GUSTY WINDS DEVELOPING DURING THE AFTERNOON...COULD SEE
A BRIEF WINDOW OF OVERLAP OF NEAR RED FLAG CONDITIONS BEFORE RH
VALUES INCREASE. LOOKS MARGINAL...SO NOT PLANNING ANY HIGHLIGHTS
THIS FORECAST CYCLE.

COULDNT RULE OUT A FEW SPRINKLES/FLURRIES DURING A BRIEF WINDOW
MONDAY NIGHT. HOWEVER...DUE TO THE PROGRESSIVE NATURE OF THIS WAVE
SUBSIDENCE WILL BE QUICK TO BUILD BACK OVER CWA...AND LARGE SCALE
ASCENT IS SOUTHEAST OF CWA BY TIME GUIDANCE SHOWS MID LEVELS
SATURATING. WILL KEEP MENTION OUT OF FORECAST FOR NOW.

SHORTWAVE RIDGING QUICKLY BUILDS BACK OVER CWA BEHIND DEPARTING
TROUGH...WITH DRY CONDITIONS AND SEASONAL TEMPS IN THE MID-UPPER
40S ON TUESDAY.

DR

.LONG TERM (WEDNESDAY-SATURDAY)...
220 AM MST SUN NOV 27 2011

THE UPPER LEVEL RIDGE WILL REMAIN OVER THE CWA WEDNESDAY BEFORE THE
UPPER LEVEL FLOW TRANSITIONS TO MORE OF A SPLIT FLOW PATTERN
THURSDAY THROUGH SATURDAY...WITH A CLOSED LOW OVER THE WESTERN CONUS
AND AN UPPER LEVEL TROUGH OVER THE NORTH AND NORTHEAST CONUS.
MODELS ARE COMING INTO BETTER AGREEMENT WITH THE SPLIT FLOW PATTERN
AND THE FRONTAL TIMING FOR THURSDAY.  CURRENTLY THE STRONG COLD
FRONT LOOKS TO MOVE THROUGH DURING THE OVERNIGHT OR EARLY MORNING
HOURS.  MODELS CONTINUE TO SHOW PRECIP. AND WINDY CONDITIONS BEHIND
THE FRONT THURSDAY.  HOWEVER MOST OF THE PRECIP. AND FORCING IS
DEPICTED WEST OF THE CWA.

FROM FRIDAY THROUGH THE WEEKEND THE MODELS ARE MUCH LESS
CONFIDENT WITH THE UPPER LEVEL FLOW.  GENERALLY THE CLOSED LOW OVER
THE SOUTHWEST CONUS MERGES WITH AN UPPER LEVEL TROUGH THAT MOVES
DOWN FROM CANADA DURING THE WEEKEND.  THE PLACEMENT OF THE UPPER
LEVEL FEATURES ONCE THE CLOSED LOW IS ABSORBED INTO THE MAIN FLOW IS
STILL IN QUESTION.  GENERALLY THE CLOSED LOW WILL MERGE WITH THE
MAIN FLOW OVER THE WESTERN HIGH PLAINS...PLACING AN UPPER LEVEL
TROUGH OVER THE CENTRAL CONUS. AHEAD OF THE UPPER LEVEL TROUGH
ANOTHER COLD FRONT WILL MOVE THROUGH THE CWA. NOT TOO CONFIDENT
WITH PRECIP. CHANCES BEHIND THE FRONT AS THIS WILL DEPEND ON
WHETHER THE UPPER LEVEL FLOW WILL MERGE BEFORE MOVING OVER THE CWA
SENDING MOISTURE OUR WAY...OR REMAIN SPLIT WHICH WOULD SEND THE
MOISTURE TO OUR NORTH AND SOUTH.

TEMPERATURES THROUGH THE PERIOD WILL BE WARMEST ON WEDNESDAY BEFORE
THE COLD FRONT MOVES THROUGH.  THROUGH THE REST OF THE WEEK
TEMPERATURES WILL BE ROUGHLY 10 DEGREES BELOW NORMAL AS THE COLD AIR
REMAINS OVER THE CWA. A BRIEF WARM UP WILL OCCUR SATURDAY...WITH
NEAR NORMAL TEMPERATURES BEFORE THE NEXT COLD FRONT MOVES
THROUGH.

JTL
&&

.AVIATION...
528 AM MST SUN NOV 27 2011

VFR CONDITIONS WILL PREVAIL FOR THE 12Z TAFS. UPPER LEVEL RIDGE
WILL CONTINUE TO BUILD OVER THE AREA TODAY. LIGHT NORTH TO NORTH
NORTHWEST WINDS CAN BE EXPECTED AND SKIES WILL BE CLEAR.

JTL
&&

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

$$








AREA FORECAST DISCUSSION

NWS GOODLAND KS

 220 AM MST SUN NOV 27 2011

.SHORT TERM (TODAY-TUESDAY)...
220 AM MST SUN NOV 27 2011


EARLY MORNING WV IMAGERY AND RUC H5 ANALYSIS SHOW UPPER LEVEL
PATTERN DOMINATED BY HIGHLY AMPLIFIED RIDGE-TROUGH PATTERN. H5
RIDGE CURRENTLY CENTERED OFF SOUTHERN CALIFORNIA COAST...WITH AXIS
EXTENDING NORTH TO SASKATCHEWAN CANADA. TROUGH AXIS CURRENTLY
EXTENDS FROM WESTERN GREAT LAKES REGION TO SOUTHERN TEXAS. BETWEEN
THESE FEATURES NORTHERLY FLOW AND LARGE SCALE SUBSIDENCE IS IN
PLACES ACROSS PLAINS.

H5 RIDGE WILL DOMINATE PATTERN OVER CWA THROUGH MON...WITH MILD
TEMPS AND DRY CONDITIONS EXPECTED. SHORTWAVE TROUGH PASSES OVER
CWA MONDAY NIGHT...WITH ASSOCIATED COLD FRONT MOVING THROUGH
DURING 18-00Z TIME PERIOD. SHOULD SEE DECENT WARMING AHEAD OF
FRONTAL PASSAGE WITH HIGHS WARMING TO NEAR 60 OVER MOST OF CWA
MIDDAY MONDAY...AND TO MID 60S ACROSS SOUTHERN EXTENT OF CWA.
WHILE GUIDANCE SHOWS TD VALUES INCREASING AHEAD OF FROPA TO LOW
20S...RH VALUES NEAR 18-20% STILL FORECAST ACROSS SOUTHERN PART OF
CWA. WITH GUSTY WINDS DEVELOPING DURING THE AFTERNOON...COULD SEE
A BRIEF WINDOW OF OVERLAP OF NEAR RED FLAG CONDITIONS BEFORE RH
VALUES INCREASE. LOOKS MARGINAL...SO NOT PLANNING ANY HIGHLIGHTS
THIS FORECAST CYCLE.

COULDNT RULE OUT A FEW SPRINKLES/FLURRIES DURING A BRIEF WINDOW
MONDAY NIGHT. HOWEVER...DUE TO THE PROGRESSIVE NATURE OF THIS WAVE
SUBSIDENCE WILL BE QUICK TO BUILD BACK OVER CWA...AND LARGE SCALE
ACSENT IS SOUTHEAST OF CWA BY TIME GUIDANCE SHOWS MID LEVELS
SATURATING. WILL KEEP MENTION OUT OF FORECAST FOR NOW.

SHORTWAVE RIDGING QUICKLY BUILDS BACK OVER CWA BEHIND DEPARTING
TROUGH...WITH DRY CONDITIONS AND SEASONAL TEMPS IN THE MID-UPPER
40S ON TUESDAY.

DR

.LONG TERM (WEDNESDAY-SATURDAY)...
220 AM MST SUN NOV 27 2011

THE UPPER LEVEL RIDGE WILL REMAIN OVER THE CWA WEDNESDAY BEFORE THE
UPPER LEVEL FLOW TRANSITIONS TO MORE OF A SPLIT FLOW PATTERN
THURSDAY THROUGH SATURDAY...WITH A CLOSED LOW OVER THE WESTERN CONUS
AND AN UPPER LEVEL TROUGH OVER THE NORTH AND NORTHEAST CONUS.
MODELS ARE COMING INTO BETTER AGREEMENT WITH THE SPLIT FLOW PATTERN
AND THE FRONTAL TIMING FOR THURSDAY.  CURRENTLY THE STRONG COLD
FRONT LOOKS TO MOVE THROUGH DURING THE OVERNIGHT OR EARLY MORNING
HOURS.  MODELS CONTINUE TO SHOW PRECIP. AND WINDY CONDITIONS BEHIND
THE FRONT THURSDAY.  HOWEVER MOST OF THE PRECIP. AND FORCING IS
DEPICTED WEST OF THE CWA.

FROM FRIDAY THROUGH THE WEEKEND THE MODELS ARE MUCH LESS
CONFIDENT WITH THE UPPER LEVEL FLOW.  GENERALLY THE CLOSED LOW OVER
THE SOUTHWEST CONUS MERGES WITH AN UPPER LEVEL TROUGH THAT MOVES
DOWN FROM CANADA DURING THE WEEKEND.  THE PLACEMENT OF THE UPPER
LEVEL FEATURES ONCE THE CLOSED LOW IS ABSORBED INTO THE MAIN FLOW IS
STILL IN QUESTION.  GENERALLY THE CLOSED LOW WILL MERGE WITH THE
MAIN FLOW OVER THE WESTERN HIGH PLAINS...PLACING AN UPPER LEVEL
TROUGH OVER THE CENTRAL CONUS. AHEAD OF THE UPPER LEVEL TROUGH
ANOTHER COLD FRONT WILL MOVE THROUGH THE CWA. NOT TOO CONFIDENT
WITH PRECIP. CHANCES BEHIND THE FRONT AS THIS WILL DEPEND ON
WHETHER THE UPPER LEVEL FLOW WILL MERGE BEFORE MOVING OVER THE CWA
SENDING MOISTURE OUR WAY...OR REMAIN SPLIT WHICH WOULD SEND THE
MOISTURE TO OUR NORTH AND SOUTH.

TEMPERATURES THROUGH THE PERIOD WILL BE WARMEST ON WEDNESDAY BEFORE
THE COLD FRONT MOVES THROUGH.  THROUGH THE REST OF THE WEEK
TEMPERATURES WILL BE ROUGHLY 10 DEGREES BELOW NORMAL AS THE COLD AIR
REMAINS OVER THE CWA. A BRIEF WARM UP WILL OCCUR SATURDAY...WITH
NEAR NORMAL TEMPERATURES BEFORE THE NEXT COLD FRONT MOVES
THROUGH.

JTL
&&

.AVIATION...
940 PM MST SAT NOV 26 2011

FOR THE 06Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD.
WINDS WILL BE LIGHT AND NORTHWESTERLY UNDER CLEAR SKIES AS HIGH
PRESSURE BUILDS OVER THE REGION.

CJS
&&

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

$$








AREA FORECAST DISCUSSION

NWS WAKEFIELD VA

 345 PM EST SUN NOV 27 2011

.SYNOPSIS...
HIGH PRESSURE SLOWLY EDGES OFF THE COAST THROUGH MONDAY. AN AREA OF
LOW PRESSURE WILL DEVELOP OVER THE DEEP SOUTH BY EARLY MONDAY AND WILL
AFFECT THE MID ATLANTIC STATES LATE MONDAY NIGHT AND TUESDAY. HIGH
PRESSURE RETURNS FOR THE MIDDLE AND LATER HALF OF THE WEEK.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
SATELLITE CONTINUES TO SHOW BANDS OF CU TRYING TO LIFT NORTHWARD
AS THE LOW LEVEL MOISTURE CONTINUES TO INCREASE IN THE SOUTHERLY
FLOW. THIS PATTERN OF SOUTHERLY FLOW WILL CONTINUE THROUGH MONDAY
NIGHT AS THE SURFACE HIGH CONTINUES TO SLIDE OFF INTO THE WESTERN
ATLANTIC AND THE UPPER TROUGH DIGS INTO THE LOWER MISSISSIPPI
BEFORE CLOSING OFF. WITH THE INCREASING OF THE LOW LEVEL
MOISTURE...EXPECT TO SEE A GRADUAL INCREASE IN THE CLOUDS TONIGHT
THROUGH THE DAY ON MONDAY WITH THE MOST CLOUDS IN THE THE LEE OF
THE PIEDMONT WITH THE TURNING OF THE FLOW TO THE SE. THE MID LEVEL
REMAIN DRY SO DO NOT SEE ANY CHANCE OF RAIN TONIGHT OR MONDAY. ON
MONDAY NIGHT AS THE UPPER LOW BEGINS TO LIFT NEWD AND THE SURFACE
FRONT BEGINS ITS APPROACH...COULD BEGIN TO SEE SOME SHOWERS
DEVELOP IN ADVANCE OF THE FRONT...BUT NOT ANTICIPATING MUCH
ACTIVITY UNTIL AFTER 6Z TUES.

FOR TEMPERATURES...WITH THE MOIST SOUTHERLY FLOW
CONTINUING...SHOULD SEE THE MILD READINGS CONTINUE. DID ALLOW FOR
SOME RADIATIONAL COOLING TONIGHT...BUT AGAIN IT WILL NOT BE AS
COOL AS PREVIOUS NIGHTS SO LOWS IN THE UPPER 40S TO THE LOWER 50S
SHOULD BE THE NORM. HIGHS TOMORROW WILL BE WARM AGAIN IN THE UPPER
60S TO LOWER 70S. CLOUDS COULD LIMIT THE HEATING SOME...BUT BEING
IN THE WARM SECTOR...THERE SHOULD BE SOME SUN SHINE AROUND. WITH
THE APPROACH OF THE FRONT AND THICKENING CLOUDS TEMPS WILL STAY UP
IN THE MID 50 TO AROUND 60 MONDAY NIGHT AS THE MOISTURE CONTINUES
TO INCREASE.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
GOING WITH A COMBINATION OF THE 12Z GFS...NAM...AND ECMWF MDLS WITH
REGARD TO TIMING OF FRNTL BNDRY AND ASSOC SHOWERS MOVNG ACRS THE
REGION DURING TUE. ONLY VRY WEAK INSTABILITY EXPECTED DURING TUE
EVEN THO TEMPS CLIMB INTO THE MID 60S OVR ERN PORTIONS OF THE AREA.
SO...SLGT CHC OF THUNDER IS ENOUGH. BULK OF PCPN WILL END GENERALLY
FM W TO E LATER TUE AFTN INTO TUE EVENG...AS FRNTL BNDRY EVENTUALLY
SLIDES OFF THE CST. MOST AREAS CUD RECEIVE BETWEEN .25 TO .50 INCH
OF RAINFALL WITH THIS SYSTEM...WITH HIER AMTS ACRS THE NRN CNTIES.
SLGT OR SML CHC OF SHOWERS...MAINLY OVR NRN THIRD OF THE AREA...WILL
LINGER LATE TUE NGT THRU WED...AS UPR LO LIFTS FM W.VA NNE INTO SE
CANADA. OTHRWISE...SHUD SEE A PRTLY SNY SKY ON WED. HIGHS ON TUE IN
THE UPR 50S TO MID 60S. LOWS TUE NGT IN THE UPR 30S TO LWR 40S.
HIGHS ON WED IN THE LWR TO MID 50S.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
FOLLOWED CLOSE TO HPC BUT USED SOME ELEMENTS OF THE GFS/EURO. ON THE
HEELS OF A POTENT STORM SYSTEM...THE LONG TERM LOOKS DRY AND COOL.
AN ACTIVE NORTHERN STREAM WILL SEND SHORT WAVES THROUGH THE AREA BUT
THEY LOOK TO BE DRY. UPPER LEVEL HIGH OVER THE GULF OF MEXICO REGION
WILL NUDGE TOWARD THE SOUTHEAST STATES TOWARD NEXT WEEKEND. AT THE
SURFACE...POLAR HIGH PRESSURE WILL SLOWLY BUILD INTO THE AREA...
INTERRUPTED BY A REINFORCING COLD FRONT LATE FRIDAY.

HIGH TEMPERATURES WILL GENERALLY BE IN THE LOW TO MID 50S BUT
COOL TO THE MID 40S TO AROUND 50 ON SATURDAY. LOW TEMPERATURES WILL
BE MAINLY IN THE 30S...WITH SOME MID TO UPPER 20S WELL INLAND BY
SUNDAY MORNING.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS CONTINUE...BUT WITH THE SFC HIGH SLIDING OFF THE SE
COAST AND THE FRONTAL BOUNDARY HAVING MOVED INTO THE OHIO
VALLEY...THE PRESSURE GRADIENT HAS TIGHTENED. THIS IS LEADING TO
INCREASING SOUTHERLY WINDS...WHICH ARE GUSTING 20 TO 25 KTS.
EXPECT THIS TO CONTINUE THROUGH THE AFTERNOON HOURS. LOW LEVEL
MOISTURE CONTINUES TO WRAP AROUND THE SFC HIGH AND HAS REACHED THE
NC/VA BORDER. IT IS PRODUCING A CU FIELD AROUND 4K FT. THIS
MOISTURE WILL CONTINUE TO SPREAD NORTHWARD THIS EVENING INTO
MONDAY. A LITTLE CONCERNED THAT AS THE WINDS TURN A BIT MORE SE
COULD SEE SOME MVFR CEILINGS...BUT FOR NOW HAVE HELD CEILINGS
ABOVE 3K FT.

AFTER 18Z MONDAY...WILL SEE AN AREA OF LOW PRESSURE FORM ALONG THE
COLD FRONT OVER THE GULF COAST STATES ON MONDAY. THIS LOW MOVES
NORTHWARD INTO THE OHIO VALLEY WITH THE COLD FRONT SWINGING
THROUGH THE SERN US INTO THE MID ATLANTIC STATES TUESDAY. THIS
WILL RESULT IN SHOWERS WITH POSSIBLE MVFR CONDITIONS. THE FLOW
TURNS SWRLY BEHIND THE FRONT WHICH SHOULD BEGIN THE CLEARING
PROCESS WITH VFR CONDITIONS RETURNING.

&&

.MARINE...
SOUTHERLY WINDS WERE AROUND 15 KNOTS SUNDAY AFTN. SENSORS THAT ARE
NOT ELEVATED AND ARE AWAY FROM THE WESTERN SHORE OF THE BAY ARE
HOLDING WELL BELOW SCA CRITERIA. THE 18Z NAM AND RUC ARE HANDLING
THIS WELL AND INDICATE A DECREASE IN WINDS TOWARDS MIDNIGHT.

WINDS AND SEAS SHOULD STAY BELOW SCA CRITERIA UNTIL THE EARLY
MORNING HOURS OF TUESDAY (LATE MONDAY NIGHT) WHEN A SOUTHEAST FETCH
OVER THE COASTAL WATERS IS EXPECTED TO BRING 5 FOOT SEAS TO WITHIN
20 MILES OF OUR SHORE. SE WINDS WILL RUN AROUND 20 KNOTS OVER THE
BAY AND POSSIBLY CURRITUCK SOUND ON TUESDAY RESULTING IN THE
LIKELIHOOD OF SCA HEADLINES. WINDS TURN TO SW BY TUESDAY NIGHT AND
MAY INCREASE TO 20-25 KNOTS OVER THE COASTAL WATERS...ESPECIALLY
OVER NORTHERN PORTIONS. WINDS AND SEAS SHOULD DECREASE TO BELOW SCA
CRITERIA BY LATE WEDNESDAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...ESS
NEAR TERM...ESS
SHORT TERM...TMG
LONG TERM...LSA
AVIATION...ESS
MARINE...LSA







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 229 PM EST SUN NOV 27 2011

.SYNOPSIS...
A SLOW MOVING STORM SYSTEM WILL BRING PERIODS OF SHOWERS
THROUGH MIDWEEK. MILD TEMPERATURES EARLY IN THE WEEK WILL COOL
SIGNIFICANTLY FOR THE LAST HALF OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
2:30 PM UPDATE: ADJUSTED POP AND TEMPS TO BETTER FIT CURRENT TRENDS...

A SLOW MOVING FRONTAL SYSTEM OVER EASTERN OHIO AT
17Z IS CREATING SHOWERS ACROSS THE AREA AS IT MOVES VERY SLOWLY
EASTWARD. BY 06 UTC THE SYSTEM WILL BE ORIENTED FROM NW PA TO SE
OH...WITH WIDESPREAD SHOWERS ALONG AND WEST OF THE FRONT...AND BY
12 UTC THE FRONT WILL BE STATIONARY ACROSS THE SAME AREA WITH
WIDESPREAD SHOWERS BACKING SLIGHTLY TO THE WEST. USED THE HRRR TO
CREATE POP FIRST SEVERAAL HOURS OF THE FORECAST...AND THE SREF
THEREAFTER TO ACCOUNT FOR UNCERTAINTY. PRECIP AMOUNTS THROUGH
TONIGHT WILL RANGE FROM VERY LITTLE SOUTHEAST OF PIT...AROUND A
QUARTER INCH FOR THE PIT METRO...TO 1-1.50 INCHES ACROSS PORTIONS
OF EASTERN OHIO. CLOUDS...PRECIP...AND SOUTHERLY FLOW WILL KEEP
TEMPERATURES VERY MILD...WITH LOWS IN THE UPPER 40S TO LOWER 50S
ACROSS THE AREA.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
LOW PRESSURE IS EXPECTED TO DEVELOP ALONG THE SOUTHERN PORTION OF
THE FRONT OVER NORTHERN GA MONDAY MORNING...THEN MOVE NORTHWARD TO
A POSITION OVER CNTRL OH BY 12 UTC TUESDAY. THIS WILL BRING
WIDESPREAD SHOWERS BACK ACROSS THE AREA TUESDAY INTO TUESDAY
NIGHT. LOW PRESSURE IS FORECAST TO EJECT TO THE NORTHEAST
TUESDAY NIGHT/WEDNESDAY WITH PRECIP COVERAGE BECOMING MORE
SCATTERED BY WEDNESDAY MORNING. USED THE SREF TO CREATE POP TO
ACCOUNT FOR UNCERTAINTY THIS PERIOD. ADDITIONAL RAINFALL AMOUNTS
THROUGH WEDNESDAY WILL RANGE FROM 0.50-1.00 INCH ACROSS SOUTHWEST
PA AND POINTS EAST TO AROUND AN INCH ACROSS EASTERN OHIO. VERY
MILD TEMPERATURES WILL CONTINUE THROUGH MONDAY NIGHT...WITH VERY
LITTLE TEMPERATURE RISE ON TUESDAY. SHARPLY COLDER TEMPERATURES
ARE EXPECTED WEDNESDAY WITH SOME ACCUMULATING SNOWS POSSIBLE ON
THE RIDGES AS WRAP AROUND MOISTURE MOVES UP THE SLOPES....BUT
MOISTURE SEEMS LIMITED AT THIS TIME. THIS POTENTIAL MAY BE
HIGHLIGHTED IN LATER FORECASTS AS CONFIDENCE INCREASES.

&&

AVIATION /18Z SUNDAY THROUGH FRIDAY/...

MODELS IN FAIRLY GOOD AGREEMENT THAT COLD FRONT INITIALLY IN WESTERN
OHIO WILL DRIFT SLOWLY EAST OVER NEXT 12-18 HOURS BEFORE STALLING IN
THE VICINITY OF PA-OH BORDER. RADAR SHOWS AREAS OF LIGHT RAIN IN
EASTERN OHIO AND WESTERN PENNSYLVANIA DRIFTING EAST WITH GENERAL VFR
CONDITIONS.  AFTER 03Z CONDITIONS WILL DETERIORATE TO MVFR THROUGH
MID MORNING.

FRONT WILL RETREAT NORTH AS STRONG LOW DEVELOPS ALONG THE FRONT
TOMORROW AND MOVES SLOWLY NORTHEAST.  EXPECT CONDITIONS TO IMPROVE
TO VFR AFTER MID MORNING MONDAY THROUGH 00Z TUESDAY. BULK OF RAIN
WILL MOVE ACROSS AREA WEDNESDAY WITH AND IFR CONDITIONS WITH
PERIODS OF MODERATE TO HEAVY RAIN AND FOG. COLD AIR WILL MOVE INTO
REGION FROM SOUTHWEST WITH RAIN CHANGING TO SNOW SHOWERS IN MOST
LOCATIONS BY WEDNESDAY MORNING WITH MIXED RAIN AND SNOW SHOWERS
WEDNESDAY.

CONDITIONS IMPROVE TO VFR BY THURSDAY MORNING WITH HIGH PRESSURE
BUILDING INTO REGION. COLD FRONT WITH LIMITED MOISTURE WILL MOVE
ACROSS REGION FROM THE GREAT LAKES WITH MVFR CONDITIONS POSSIBLE
FROM 18Z FRIDAY THROUGH 06Z SATURDAY.

BEHIND FRONT VFR CONDITIONS FORECAST THROUGH THE WEEKEND.

.LONG TERM WEDNESDAY NIGHT THROUGH SUNDAY.
BY WEDNESDAY EVENING NORTHERLY FLOW BEHIND EXITING STORM IN NEW
ENGLAND MAY KEEP A FEW SHOWERS/FLURRIES OVER REGION EARLY. HIGH
PRESSURE WILL BUILD NORTHEAST TO WV BY THURSDAY MORNING BRINGING
DRIER AIR AND SUNSHINE.  MODELS CONSISTENT WITH COLD MOVING
SOUTHEAST FROM GREAT LAKES ON FRIDAY WITH LIMITED MOISTURE. CHANCE
OF SHOWERS FROM MID DAY FRIDAY ON.  BY SATURDAY BROAD WESTERLY FLOW
WILL BRING COLDER TEMPERATURES WITH LOWS IN THE 20S AND HIGHS IN THE
30S AND LITTLE THREAT OF PRECIPITATION FOR THE WEEKEND.

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

&&

$$







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 213 PM EST SUN NOV 27 2011

.SYNOPSIS...
A SLOW MOVING STORM SYSTEM WILL BRING PERIODS OF SHOWERS
THROUGH MIDWEEK. MILD TEMPERATURES EARLY IN THE WEEK WILL COOL
SIGNIFICANTLY FOR THE LAST HALF OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
2:15 PM UPDATE: A SLOW MOVING FRONTAL SYSTEM OVER EASTERN OHIO AT
17Z IS CREATING SHOWERS ACROSS THE AREA AS IT MOVES VERY SLOWLY
EASTWARD. BY 06 UTC THE SYSTEM WILL BE ORIENTED FROM NW PA TO SE
OH...WITH WIDESPREAD SHOWERS ALONG AND WEST OF THE FRONT...AND BY
12 UTC THE FRONT WILL BE STATIONARY ACROSS THE SAME AREA WITH
WIDESPREAD SHOWERS BACKING SLIGHTLY TO THE WEST. USED THE HRRR TO
CREATE POP FIRST SEVERAAL HOURS OF THE FORECAST...AND THE SREF
THEREAFTER TO ACCOUNT FOR UNCERTAINTY. PRECIP AMOUNTS THROUGH
TONIGHT WILL RANGE FROM VERY LITTLE SOUTHEAST OF PIT...AROUND A
QUARTER INCH FOR THE PIT METRO...TO 1-1.50 INCHES ACROSS PORTIONS
OF EASTERN OHIO. CLOUDS...PRECIP...AND SOUTHERLY FLOW WILL KEEP
TEMPERATURES VERY MILD...WITH LOWS IN THE UPPER 40S TO LOWER 50S
ACROSS THE AREA.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
LOW PRESSURE IS EXPECTED TO DEVELOP ALONG THE SOUTHERN PORTION OF
THE FRONT OVER NORTHERN GA MONDAY MORNING...THEN MOVE NORTHWARD TO
A POSITION OVER CNTRL OH BY 12 UTC TUESDAY. THIS WILL BRING
WIDESPREAD SHOWERS BACK ACROSS THE AREA TUESDAY INTO TUESDAY
NIGHT. LOW PRESSURE IS FORECAST TO EJECT TO THE NORTHEAST
TUESDAY NIGHT/WEDNESDAY WITH PRECIP COVERAGE BECOMING MORE
SCATTERED BY WEDNESDAY MORNING. USED THE SREF TO CREATE POP TO
ACCOUNT FOR UNCERTAINTY THIS PERIOD. ADDITIONAL RAINFALL AMOUNTS
THROUGH WEDNESDAY WILL RANGE FROM 0.50-1.00 INCH ACROSS SOUTHWEST
PA AND POINTS EAST TO AROUND AN INCH ACROSS EASTERN OHIO. VERY
MILD TEMPERATURES WILL CONTINUE THROUGH MONDAY NIGHT...WITH VERY
LITTLE TEMPERATURE RISE ON TUESDAY. SHARPLY COLDER TEMPERATURES
ARE EXPECTED WEDNESDAY WITH SOME ACCUMULATING SNOWS POSSIBLE ON
THE RIDGES AS WRAP AROUND MOISTURE MOVES UP THE SLOPES. THIS
POTENTIAL WILL BE HIGHLIGHTED IN LATER FORECASTS AS CONFIDENCE
INCREASES.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
RESIDUAL SNOW SHOWERS WILL END WEDNESDAY EVENING AS THE LOW
EXITS TO THE EAST. MAINLY DRY CONDITIONS WILL PREVAIL THURSDAY
UNDER LOW AMPLITUDE RIDGING. A WEAK FRONTAL BOUNDARY IS PROGGED
TO CLIP THE AREA FRIDAY/FRIDAY NIGHT FOR A LOW CHANCE OF RAIN/SNOW
SHOWERS. SATURDAY LOOKS MAINLY DRY. TEMPERATURES 5-10 DEGREES
BELOW NORMAL WILL PREVAIL.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS EXPECTED AT ALL PORTS THROUGH THE MORNING HOURS. A
COLD FRONT WILL SLOWLY MOVE ACROSS OHIO THIS AFTERNOON. FRONT WILL
THEN STALL OVER THE UPPER OHIO VALLEY TONIGHT.

AN AREA OF BKN-OVC MIDDLE CLOUDS WILL MOVE AHEAD OF THE FRONT AND
OVERSPREAD THE REGION BY THIS AFTERNOON. SOUTHERLY SFC WINDS WILL
BECOME GUSTY BY LATE MORNING AND CONTINUE THROUGH THE AFTERNOON.
EXPECT GUSTS AROUND 20KTS AT MOST PORTS. LLWS IS POSSIBLE LATER
TODAY AS A STRONG LL JET WILL MOVE ACROSS THE REGION. FOR NOW,
WILL NOT MENTION IN THE FORECAST, BUT THIS WILL NEED TO BE
REASSESSED LATER TODAY.

THE DIFFICULT PART OF THE FORECAST BEGINS LATER THIS EVENING,
ATTEMPTING TO TIME THE ONSET OF RESTRICTIONS AND HOW FAR AND HOW
FAST THESE WILL SPREAD EASTWARD.

FOR CURRENT FORECAST, WILL BRING RESTRICTIONS TO ZZV WITH RAIN
SHOWERS THIS EVENING. RESTRICTIONS MAY REACH ALSO FKL JUST AFTER
00Z.


OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
PERIODS OF SHOWERS AND RESTRICTIONS WILL BE POSSIBLE AT ALL PORTS
THROUGH WEDNESDAY. ON MONDAY, SHOWERS SHOULD GENERALLY BE FROM
PITTSBURGH WEST, WITH THE MAIN RAIN SHIELD MOVING IN ON TUESDAY AND
TUESDAY NIGHT. EXPECT RESTRICTIONS TO CONTINUE INTO WEDNESDAY,
ALTHOUGH MOST OF THE PRECIPITATION WILL SHIFT NORTHWARD. VFR
EXPECTED ON THURSDAY UNDER HIGH PRESSURE.

&&

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

&&

$$







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 746 PM EST MON NOV 28 2011

.SYNOPSIS...

WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW PROGRESSIVE FLOW ACROSS
SRN CANADA...FEATURING A WEAK RIDGE OVER SW CANADA...A SHORTWAVE
TROF OVER MANITOBA AND ANOTHER SHORTWAVE OVER QUEBEC. A CUTOFF LOW
IS OVER THE LWR MISSISSIPPI VALLEY. INCREASING SW FLOW AHEAD OF THE
MANITOBA SHORTWAVE HAS SCOURED OUT LOW CLOUDS ACROSS MOST OF THE
FCST AREA WITH DOWNSLOPING NEAR LAKE SUPERIOR AIDING THE CLEARING
TREND. AS OF 2030Z...LAST OF THE LOW CLOUDS ARE DOWNWIND OF LAKE
MICHIGAN...E OF KESC-GRAND MARAIS LINE. APPROACHING COLD FRONT
ASSOCIATED WITH MANITOBA SHORTWAVE IS NOT ACCOMPANIED BY ANY PCPN S
OF THE INTERNATIONAL BORDER AS AIRMASS IS DRY PER 12Z SOUNDINGS. &&

.SHORT TERM /TONIGHT AND TUE/...

SHORT TERM WILL BE GENERALLY QUIET AS OVERALL DRY AIRMASS LIMITS ANY
PCPN POTENTIAL DESPITE PASSAGE OF SHORTWAVE. COLD FRONT ASSOCIATED
WITH SHORTWAVE MOVING ACROSS ONTARIO TONIGHT WILL BRING A WIND SHIFT
AND USHER IN A PERIOD OF DECENT CAA (850MB TEMPS FALL FROM 0 TO 2C
THIS EVENING TO -6 TO -8C BY 12Z TUE). SHOULD BEGIN TO SEE AN
INCREASE IN LAKE EFFECT CLOUDS OVERNIGHT AS OVERWATER INSTABILITY
IMPROVES. OTHERWISE...NO PCPN IS EXPECTED AS AIRMASS IS DRY.

ON TUE...BRISK N WINDS AND MORE THAN ADEQUATE OVERWATER INSTABILITY
WILL LEAD TO QUITE A BIT OF STRATOCU OFF LAKE SUPERIOR. ALTHOUGH
850MB TEMPS ARE MARGINALLY COLD TO SUPPORT FLURRIES/-SHSN OFF THE
LAKE...TEMPS IN THE SHALLOW MOIST LAYER ARE JUST ABOVE -10C. IF
ANYTHING...THERE MIGHT BE SOME -FZDZ...BUT SUBCLOUD LAYER ON FCST
SOUNDINGS LOOKS TOO DRY TO SUPPORT THAT. THE LACK OF LOW CLOUDS WELL
UPSTREAM SUPPORTS MODEL FCST OF SOMEWHAT DRIER LOWER BOUNDARY LAYER.
IF THERE SOMEHOW IS A LITTLE PCPN TUE...IT WOULD PROBABLY BE OVER
NCNTRL UPPER MI (ERN BARAGA/MARQUETTE/WRN ALGER) DUE TO
PRECONDITIONING/STREAMLINE OFF LAKE NIPIGON INTO THAT AREA. IT WILL
BE A SEASONABLY CHILLY DAY WITH HIGHS IN THE UPPER 20S TO MID 30S.

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...

TUESDAY NIGHT THROUGH WEDNESDAY EVENING...
WITH THE CONTINUED NORTHEASTWARD EJECTION OF
THE CUT OFF LOW OVER THE OHIO VALLEY AT 00Z WEDNESDAY TO THE LOWER
GREAT LAKES BY DAYBREAK WEDNESDAY...AND ACROSS QUEBEC THEREAFTER.
THE RESULT FOR THE UPPER GREAT LAKES WILL BE A 500MB RIDGE
OVERHEAD...AND A RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE AREA
FROM TX. SENSIBLE WEATHER WISE...EXPECT DRY CONDITIONS WITH WARMING
ALOFT FROM A CWA AVERAGE -4 TO -1C AT 850MB DURING THE PERIOD.

THURSDAY MORNING THROUGH FRIDAY MORNING...
THE NEXT FEATURE OF INTEREST WILL BE SLIDING ACROSS EASTERN MT
WEDNESDAY MORNING...AND BETTER ORGANIZING FROM ND TO EASTERN CO BY
18Z WEDNESDAY. THE FEATURE WILL THEN WEAKEN AS IT SETS UP FROM UPPER
MI THROUGH TX BY 18Z THURSDAY. WITH THE ASSISTANCE OF SOME MID LEVEL
SUPPORT ON THE NORTHERN EDGE OF THIS FEATURE /500MB TROUGH EXTENDING
SW FROM THE NORTHERN PORTIONS OF HUDSON BAY/ LIGHT PRECIPITATION
WILL BE POSSIBLE...MAINLY BEHIND THE SFC LOW. NORTHERLY FLOW AND
850MB TEMPS OF -7 TO -9C BY 18Z THURSDAY SHOULD BRING ABOUT LIGHT
SNOW SHOWERS. INDICATIONS CONTINUE TO POINT AT 1 TO 3 INCHES OF SNOW
THURSDAY ACROSS THE KEWEENAW PENINSULA...WITH VALUES REMAINING BELOW
ADVISORY HEADLINE CRITERIA AT THIS TIME. COOLER NW FLOW WILL THEN
DOMINATE THURSDAY NIGHT WITH 850MB TEMPS BOTTOMING OUT AROUND -13C
BY 12Z FRIDAY...WHILE THE 500MB AXIS AND SFC FRONT EXIT TO OUR
EAST...LIMITING SIGNIFICANT SNOWFALL ACCUMULATIONS.

FRIDAY AFTERNOON AND EVENING...
WAA WILL QUICKLY TAKE HOLD FRIDAY AFTERNOON THROUGH THE EVENING
HOURS WITH 850MB TEMPS REBOUNDING TO AROUND -1 TO -4C DEPENDING ON
WHAT MODEL YOU BELIEVE...AND A WEAK RIDGE SLIDING ACROSS ALOFT.
EITHER WAY IT SHOULD BE DRY WITH SW WINDS...WITH THE LAST OF THE
LAKE EFFECT/LAKE ENHANCED PRECIP ENDING AT 12Z FRIDAY ON MAINLY
WESTERLY WINDS.

BEYOND FRIDAY EVENING THE FORECAST BEGINS TO BECOME A LITTLE LESS
PREDICTABLE. A 500MB TROUGH SET UP FROM N CENTRAL CANADA THROUGH MT
AT 18Z FRIDAY WILL ATTEMPT TO PUSH A SOUTHWESTERN U.S. CUT OFF LOW
INTO THE MAIN FLOW OVER THE WEEKEND...WITH THE ELONGATED TROUGH
SLIDING OVER THE UPPER GREAT LAKES SOMETIME BETWEEN SATURDAY MORNING
AND SUNDAY AFTERNOON...WITH AN ADDITIONAL WAVE ALMOST RIGHT BEHIND
THE PRIMARY WAVE FOR SUNDAY AFTERNOON OR MONDAY AFTERNOON.
YES...THERE IS NEARLY A 24 HOUR DIFFERENCE BETWEEN THE 28/00Z RUN OF
THE ECMWF AND THE 28/00Z AND 06Z RUNS OF THE GFS. THE 12Z RUNS OF
THE GFS AND ECMWF HAVE COME INTO A LITTLE BETTER AGREEMENT ONCE
AGAIN...AND WE WILL HAVE TO WAIT AND SEE IF THIS TREND CONTINUES.
&&

.AVIATION /FOR THE 00Z TAF ISSUANCE/...

EXPECT VFR CONDITIONS TO PREVAIL THRU MUCH OF THE NIGHT DESPITE THE
PASSAGE OF A COLD FRONT. INITIALLY...AIRMASS WILL BE TOO WARM
FOR LAKE EFFECT CLOUDS...BUT MAY NEED TO WATCH FOR A BRIEF PERIOD
OF MVFR CIGS JUST BEHIND FRONT THIS EVENING. SATELLITE IMAGERY/SFC
OBS SHOW A NARROW POST-FRONTAL BAND OF MVFR CIGS...BUT THERE IS
UNCERTAINTY WHETHER THE SRN END OF THE STRATOCU DECK WILL SLIP FAR
ENOUGH S TO AFFECT KCMX/KSAW. AS AIRMASS BECOMES COLDER AND
OVERWATER INSTABILITY INCREASES...EXPECT STRATOCU/MVFR CIGS TO
DEVELOP OFF LAKE SUPERIOR AND AFFECT KIWD/KCMX/KSAW THROUGH MUCH OF
THE DAY ON TUESDAY.
&&

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

TYPICAL CHANGEABLE LATE FALL PATTERN EXPECTED THIS WEEK. COLD FRONT
WILL PASS ACROSS THE AREA TONIGHT. MAY SEE A FEW GALE FORCE GUSTS
BTWN ISLE ROYALE AND THE KEWEENAW LATE THIS AFTN IN THE SW FLOW
AHEAD OF THE FRONT. BEHIND THE FRONT IN DECENT CAA REGIME...THERE
MAY BE SOME NORTHERLY GALE FORCE GUSTS FROM NCNTRL TO SCNTRL LAKE
SUPERIOR OVERNIGHT/EARLY TUE AS OVERWATER INSTABILITY INCREASES. AT
THIS TIME...IT APPEARS GALE GUSTS SHOULDN`T BE WIDESRPEAD OR
PERSISTENT ENOUGH TO WARRANT A GALE WARNING. WINDS WILL SLOWLY
DIMINISH FROM W TO E TUE AFTN/NIGHT AS HIGH PRES RIDGE MOVES CLOSER
TO THE AREA. LIGHTER WINDS UNDER 20KT WILL BE THE RULE WED
AFTN/NIGHT UNDER WEAK PRES GRADIENT ASSOCIATED SFC TROF SETTLING SE
INTO THE UPPER LAKES. N TO NW WINDS WILL INCREASE INTO THE 15-25KT
RANGE THU/THU NIGHT AS THE TROF SLIPS SE OF THE AREA. AFTER A BRIEF
PERIOD OF LIGHTER WINDS LATE THU NIGHT/FRI MORNING...WINDS WILL
AGAIN BE ON THE INCREASE LATER FRI INTO SAT AHEAD OF THE NEXT LOW
PRES TROF APPROACHING FROM THE NW. MAY SEE GALES IN THE SW FLOW
AHEAD OF THE TROF.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
  GALE WARNING FROM 7 AM TO 7 PM EST TUESDAY FOR LMZ221-250.

&&

$$

SYNOPSIS...ROLFSON
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JV
MARINE...ROLFSON









AREA FORECAST DISCUSSION

NWS GAYLORD MI

 207 PM EST SUN NOV 27 2011

.SYNOPSIS.../ISSUED AT 1126 AM/

A COLD FRONT HAS DELIVERED A COOLER AIR MASS TO NORTHERN MICHIGAN.
LIGHT RAIN AND SNOW WILL GRADUALLY END FROM WEST TO EAST THIS
AFTERNOON. SOME LIGHT LAKE EFFECT RAIN OR RAIN/SNOW MIX WILL
DEVELOP TONIGHT...BUT PRECIPITATION AMOUNTS WILL BE VERY LIGHT. THERE
WILL BE A BRIEF BREAK FROM PRECIPITATION MONDAY...BUT THEN
PRECIPITATION CHANCES WILL RETURN TUESDAY...MAINLY SOUTHEAST OF
GAYLORD. TEMPERATURES WILL BE SEASONABLY COLD THIS UPCOMING WEEK.

TL/JH

&&

.SHORT TERM.../ISSUED AT 207 PM/...THIS AFTERNOON

...LIGHT SYNOPTIC RAIN/SNOW WILL GRADUALLY END WITH A MUCH MORE
SEASONABLE AIR MASS NOW ESTABLISHED FOR THE UPCOMING WEEK...

MESOSCALE UPDATE 207 PM: LAKE INSTABILITY IS ARRIVING FASTER THAN
EXPECTED PER APX 88D. LIGHT R/S SHWRS HAVE DEVELOPED OVER MUCH OF NW
LOWER. WILL AMEND THE FCST TO ACCOUNT FOR THIS. SLOW MOVEMENT OF
UPPER TROF HAS DEPLAYED THE EXIT OF DEEPER MSTR. SO DGZ WILL BE
SATURATED FOR A WHILE LONGER THAN PREVIOUSLY EXPECTED. STILL PLAN TO
TRANSITION TO ALL LIQUID NRN LOWER LATE THIS AFTN INTO TNGT.

PLEASE SEE CLIMATE SECTION FOR RECORD WARM LOW TEMPS SAT 11/26.

HIGHLY AMPLIFIED BUT SLOWLY PROGRESSIVE FLOW IS OVER THE CONUS. THE
MERIDIONAL UPPER TROF /NESTLED BETWEEN 2 SUBTROPICAL RIDGES/ HAS
ADVANCED FROM THE PLAINS TOWARD THE MS RIVER VALLEY IN THE PAST 24
HRS...WITH ITS WAVELENGTH DECREASING. THIS TROF WILL BEGIN
BIFURCATING TODAY WITH THE PORTION AFFECTING THE GTLKS REMAINING
PROGRESSIVE.

THE ASSOCIATED ANABATIC COLD FRONT WAS E OF THE FCST AREA...
EXTENDING FROM A 1002 MB LOW S OF JAMES BAY...TO LAKE HURON...TO
THE THUMB. NNW WINDS UP TO 30 KTS WILL CONTINUE ADVECTING COOLER
SEASONABLE AIR IN THE AREA.

SYNOPTIC PCPN: BACK EDGE OF PCPN SHIELD HAS CHANGED OVER TO SNOW AND
WILL END FROM NW TO SE THIS AFTN WITH NO ACCUM.

88D CORRELATION COEFFICIENT SHOWS R/S LINE PROGRESSING SEWD...
CONFIRMED BY TRANSITION HERE AT OFFICE AND SPOTTER REPORTS.

BACK EDGE OF PCPN LINES UP WITH DEEP MSTR. SO ONCE -SN ENDS THE DGZ
DRIES OUT PER RUC FCST SOUNDINGS. SO EXPECT PCPN TO END OVER NRN
LOWER. SHOULD SEE CHANGOVER TO -SN ALL THE WAY TO LAKE HURON/SAGINAW
BAY. UPSTREAM PIREPS CONFIRM SATL AND 12Z 700 CHART MID-LEVEL
DRYING. CLOUD TOPS ARE 4-6K FT UPSTREAM.

LAKE EFFECT PCPN: THE MQT 88D IS ALREADY SHOWING LAKE DEVELOPMENT ON
SUPERIOR AS LOW-LEVEL THERMAL PROFILE /INSTABILITY/ IS SUPPORTIVE.
IT WILL TAKE UNTIL 21Z FOR CAA TO ADVECT FAVORABLE LAPSE RATES INTO
NW LOWER. HOWEVER...FRONTAL INVERSION WILL CAP LAKE CLOUDS TO 850 MB.
AM NOT EXPECTING MUCH MORE THAN WIDESPREAD CLOUDS AS THE DGZ NEVER
RE-SATURATES.

IT WILL BE MOIST UP TO 850. SO NW FLOW INTO HIGHER TERRAIN SHOULD
PRODUCE SOME DRIZZLE.

OVER THE EASTERN U.P. EXPECTED R SHWRS TO POSSIBLY MIX WITH SNOW
LATE...AS INVERSION DEEPENS JUST ENOUGH TO ICE CRYSTALS TO DEVELOP.
BUT IT MAY NOT BE ENUF FOR SNOW.

THIS HAS NECESSITATED CHANGES TO THE FCST ISSUED AT 403 AM. BROUGHT
SNOW TO AN END AS DEEP MSTR DEPARTS...AND CHANGED R TO S BEFORE
ENDING SE OF GAYLORD. ALL LAKE PCPN OVER THE U.P. HAS BEEN CHANGED
FROM S TO A R/S MIX. ALL SNOW HAS BEEN REMOVED FROM THE FCST FOR NRN
LOWER. WHAT MINISCULE SNOWFALL AMTS WERE FCST HAVE BEEN ZERO`D OUT.

TEMPS WILL CONTINUE FALLING ANOTHER 4-7F ALONG LAKE HURON/SAGINAW
BAY. ELSEWHERE...TEMPS WILL HOLD STEADY THE REST OF THE DAY.


DUAL POL PCPN ESTIMATES: THIS IS OUR FIRST PCPN EVENT SINCE
RETURNING TO SERVICE WITH DUAL POL. OVERALL PCPN ESTIMATES ARE
SUPERIOR TO THE LEGACY ALGORITHM. LEGACY WAS GENERALLY TOO LOW.
THE MAIN DISAGREEMENT WAS OVER BENZIE/MANISTEE COUNTIES WHERE AN
AVERAGE OF THE TWO WAS THE BEST. DUAL POL ACCUMULATION WAS WAY TO
HIGH BY UP TO 2 TIMES...MOST LIKELY DUE TO MELTING ISSUES.

HALBLAUB

&&

.LONG TERM.../ISSUED AT 417 AM/...TONIGHT AND BEYOND

SOME QUIETER WX FOR A DAY OR SO...AS HIGH PRESSURE WEDGES IN
OVERHEAD BETWEEN SYSTEMS IN THE DEEP SOUTH AND UP BY HUDSON BAY.
MODELS HAVE TRENDED WESTWARD WITH THE EJECTING SOUTHERN LOW BY
TUESDAY...AND AS THE PREVIOUS SHIFT NOTED WE MAY GET CLIPPED BY THE
BROAD PRECIP SHIELD NW OF THIS SYSTEM...PERHAPS AS SOON AS LATE
MONDAY NIGHT. PRECIP TRENDS (INCLUDING PRECIP TYPE) ARE THE MAIN
CONCERN.

MODELS...HEY...ANOTHER TWO-CAMP SOLUTION. THIS TIME THE GFS/UKMET
ARE IN A MORE NORTHERLY CAMP WITH THE EJECTING SOUTHERN UPPER LOW
(EASTERN OHIO TUESDAY EVENING)...WHICH WOULD RESULT IN WETTER WX
HERE. THE OPERATIONAL GFS OFFERS THE MOST DIRE SOLUTION.
MEANWHILE...THE NAM...ECMWF...AND GEM ARE MORE SOUTHERLY (TN/NC/VA
BORDER AREA) AND DRIER. HPC RECOMMENDS HEDGING OUR BETS WITH A
GFS/ECMWF COMPROMISE...WHICH SEEMS A REASONABLE APPROACH UNTIL
THINGS GETS FURTHER NAILED DOWN.

TONIGHT/MONDAY...MODELS HAVE TRENDED COLDER TONIGHT...WITH 850MB
TEMPS OF -9C LINGERING TO AROUND MIDNIGHT (DELTA T/S 15-16). WILL
ADJUST POPS TONIGHT HIGHER...WITH A SMALL AREA OF LIKELY POPS IN
BOTH PENINSULAS IN NW/NNW SNOWBELTS. AM A LITTLE CONCERNED WE COULD
MANAGE SOME SNEAKY 1-2 INCH ACCUMS...ESPECIALLY GIVEN THE SOLID
SUPERIOR CONNECTION INTO NW LOWER. BUT WE WON/T HAVE MUCH TIME FOR
CONVECTION TO RECOVER/REORGANIZE AFTER DIURNAL DISRUPTIONS...BEFORE
THE 850MB THERMAL TROF LIFTS OUT TO THE NE OVERNIGHT. BY 12Z...850MB
TEMPS WILL BE DOWN TO THE -4/-5C RANGE...AND THERE SHOULDN/T BE ANY
PRECIP LEFT FOR MONDAY. SKIES WILL TEND TO CLEAR MONDAY...WITH HIGH
PRESSURE OVERHEAD AND A NARROW WEDGE OF SHARP SUBSIDENCE (850-700MB
RH GOES BELOW 20 PERCENT). SOME MID/HIGH CLOUDS WILL LINGER NEAR
SAGINAW BAY.

MIN TEMPS IN THE 20S TONIGHT...WITH SOME UPPER TEENS POSSIBLE IN
INTERIOR SECTIONS OF NE LOWER MI. MAX TEMPS UPPER 30S TO AROUND 40F.

MONDAY NIGHT/TUESDAY...A NORTHERN STREAM SHORTWAVE WILL MAKE
EASTWARD PROGRESS ACROSS NORTHERN MN MONDAY NIGHT...AND THEN WILL
WASH OUT AS THE LARGER CIRCULATION TO THE SOUTH AND SE TAKES OVER.
BAND OF F-GEN AND ASSOCIATED MID CLOUDS AHEAD OF THIS WAVE WILL
REACH EASTERN UPPER MI BY DAWN TUESDAY...PRODUCING VIRGA AND MAYBE A
FLURRY.

THE BIGGER CONCERN IS THE DEEP LOW TO THE SOUTH. MODEL DIFFS ARE
RELATIVELY MINOR THRU 12Z TUESDAY...WITH RAIN DEFINITELY MOVING INTO
SE LOWER MI...AND NAM/GFS BOTH TRY TO BACK UP PRECIP TOWARD SAGINAW
BAY. WILL MAINTAIN A CHANCE OF RAIN IN THE SE ZONES (ALL PRECIP
LIQUID THERE...WITH 850MB TEMPS 3-4C...AND SURFACE TEMPS IN THE MID
30S. ALL MODELS CONTINUE TO SLOWLY EXPAND PRECIP NORTHWARD AS THE
UPPER LOW LOVES UP THE TN VALLEY AND CENTRAL APPALACHIANS. WILL
BOOST AND EXPAND POPS...WITH LIKELY POPS ALONG/SE OF HTL-APN...AND
CATEGORICAL NEAR TAWAS/STANDISH. THIS WILL ALMOST ALL LIQUID...WITH
ABOVE FREEZING 850MB AND SURFACE TEMPS IN MOST OF THE PRECIP AREA.
HOWEVER...ALONG THE OUTER EDGE OF THE PRECIP SHIELD...850MB TEMPS
WILL DROP SLIGHTLY BELOW ZERO...AND THE SURFACE-BASED WARM LAYER
WILL SHRINK BELOW 1K FEET. WILL MENTION A RAIN/SNOW MIX ALONG THE NW
EDGE (MANISTEE TO CHEBOYGAN).

MIN TEMPS UPPER 20S TO AROUND 30 IN MOST PLACES...EXCEPT LOW/MID 30S
FAR SE. MAX TEMPS MID 30S TO LOWER 40S.

REST OF THE FORECAST...FORECAST RAPIDLY TURNS MORE INTERESTING TUE
NIGHT. AS THE SURFACE LOW PASSES BY TO THE EAST...COLD
ADVECTION FROM 850MB ON DOWN WILL RAPIDLY TURN PRECIP FROM RAIN TO
SNOW. PRECIP WILL BE DWINDLING LATE TUE NIGHT AND OUT OF THE PICTURE
COMPLETELY BY MIDDAY WEDNESDAY. WILL INCREASE POPS TUESDAY
NIGHT...INCLUDING ADDING SOME LIKELY POPS IN NE LOWER (RAIN/SNOW MIX
IN THE EVENING...ALL SNOW OVERNIGHT). SNOW POTENTIAL VARIES GREATLY
FROM MODEL TO MODEL...AS THEY DIFFER ON BOTH PRECIP PRODUCTION (GFS
IS QUITE WET...UP TO AN INCH OF QPF TUE NIGHT IN NE LOWER)...AND ON
HOW QUICKLY TO TURN PRECIP TO SNOW. CERTAINLY POTENTIAL IS THERE FOR
MODERATE (ADVISORY-LEVEL) ACCUMS...PERHAPS EVEN MORE IN A WORST-CASE
SCENARIO.

JZ

&&

.MARINE.../ISSUED AT 1126 AM/

AT 11 AM...ADDED THE STRAITS TO THE SCA. OTHERWISE ALL OTHER SCA
HEADLINES REMAIN AS IS FROM 405 AM ISSUANCE.

COLD FRONT HAS EXITED THE WATERS SURROUDNING NRN MI. NW- NNW
GUSTS WILL CONTINUE 25-30KT IN MOST PLACES WELL.

HALBLAUB

WINDS WILL DIMINISH LATE TONIGHT INTO MONDAY AS HIGH PRESSURE
BRIEFLY SETTLES INTO THE LAKES REGION.

JZ

&&

.AVIATION.../ISSUED AT 207 PM/...VALID FOR 18Z TAFS

COLD FRONT HAS DEPARTED THE REGION AND COOLER AIR MASS NOW
ESTABLISHED. LARGE-SCALE LGT PCPN IS ENDING AND PATTERN IS
TRANSITIONING TO LGT LAKE EFFECT RA/SN SHWRS FOR TVC/PLN/MBL. LAKE
EFFECTS WILL END MON WITH CIGS IMPROVING TO LOW-END VFR. CONFIDENCE
IS HIGH ON OCCURRENCE BUT LOW ON TIMING OF TRANSITION TO VFR.

REST OF THIS AFTN: 1200-1500 FT MVFR CIGS WILL LIFT TO 2000-2800 FT.
VSBYS MOSTLY UNRESTRICTED BUT BRIEF REDUCTION TO MVFR POSSIBLE IN AN
HEAVIER RA/SN SHWRS. NW WINDS WILL AVERAGE 10-15 KTS WITH AN
OCCASIONAL G20.

TNGT: MVFR 2000-3000 FT CIGS. AN OCCASIONAL -SHRA OR -DZ WILL REMAIN
POSSIBLE PLN/TVC/MBL...ESPECIALLY BEFORE 06Z. NW WINDS WILL DIMINISH
BELOW 10 KTS AND PROBABLY TURN CALM OR VRB03 BY 09Z.

MON THRU 18Z: ANY LEFTOVER MVFR CIGS LIFT AND BECOME VFR SCT-BKN
3500 FT. LIGHT WINDS.

HALBLAUB

&&

.CLIMATE.../ISSUED AT 1126 AM/

RECORDS: ALL LONG-TERM CLIMATE SITES EXCEPT SSM SET/TIED THE WARMEST
LOW TEMPS ON RECORD YESTERDAY.

APN 45F (OLD RECORD 41 IN 1948)
GLR 46F (OLD RECORD 39 IN 2009)
HTL 48F (OLD RECORD 43 IN 2006)
TVC 50F (TIED OLD RECORD 50 IN 1915)

HALBLAUB

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR LHZ345-347-348.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR LMZ323-342-
     344>346.
LS...SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR LSZ321.

&&

$$

WFO APX









AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 1236 PM EST SUN NOV 27 2011

UPDATED AVIATION DISCUSSION FOR 18Z TAFS

.UPDATE...
IT HAS BEEN A STRUGGLE TO SEE LES DEVELOPMENT THIS MORNING...MOST
LIKELY DUE TO THE VERY STRONG SUBSIDENCE INVERSION NOTED ON THE 12Z
INL SOUNDING AND NEUTRAL TO JUST SLIGHTLY CYCLONIC PBL FLOW. HAVE
SEEN SOME BETTER BANDING BETWEEN MARQUETTE AND MUNISING IN THE LAST
FEW HOURS MOST LIKELY OWED TO SLIGHT ENHANCEMENT FROM LAKE NIPIGON
AND FROM BEING ON THE WESTERN EDGE OF THE MID LEVEL CLOUDS. WITH
THAT BEING SAID...HAVE RAISED POPS THIS MORNING IN WESTERN ALGER
COUNTY TO CATEGORICAL AND ALSO RAISED ACCUMULATIONS TO UP TO 3
INCHES WELL INLAND OF LAKE SUPERIOR. IF NOTHING ELSE...SOME
UNTREATED ROADS WILL BECOME A LITTLE SLIPPERY IN THIS AREA ALONG THE
M-94 CORRIDOR BETWEEN SKANDIA AND WETMORE.

OTHERWISE...WITH THE DRY AIR AND BUILDING HEIGHTS MOVING INTO
WESTERN UPPER MI BY THIS AFTN...HAVE OPTED TO JUST GO WITH SCATTERED
SNOW SHOWERS FOR THE REMAINDER OF THE DAY IN THIS AREA.

IN ADDITION...TEMPS WILL STRUGGLE TO RISE MUCH TODAY DUE TO CLOUD
COVER AND COLD ADVECTION. WILL GENERALLY GO WITH STEADY TEMPS IN THE
UPPER 20S WEST AND MID 30S EAST.
&&

.SYNOPSIS /ISSUED AT 442 AM/...
WV IMAGERY AND RUC ANALYSIS INDICATED A HIGH AMPLITUDE PATTERN WITH
A MID/UPPER LEVEL RIDGE OVER THE WRN CONUS AND A TROUGH OVER THE
CNTRL CONUS FROM NW ONTARIO TO CNTRL TX. THE BACK EDGE OF THE DEEPER
MOISTURE WAS MOVING STEADILY EASTWARD AND WAS NEAR A INL-MSP LINE.
AT THE SFC...LOW PRES NE OF LAKE SUPERIOR CONTINUED TO LIFT OFF TO
THE NE THROUGH NRN ONTARIO. CAA IN THE WAKE OF THE LOW HAD DROPPED
850 MB TEMPS TO NEAR -10C OVER WRN LAKE SUPERIOR. EVEN THOUGH
KINL/CYPL SOUNDINGS INDICATED A MOISTURE PROFILE THROUGH LOW AND MID
LEVELS FAVORABLE FOR LAKE EFFECT SNOW...WITH ONLY MARGINAL
INSTABILITY (LK-H8 DELTA/T TO 15C)AND THE CLOUD LAYER BLO THE DGZ
LAYER (10K-14K FT) SNOW HAS BEEN RELATIVELY LIGHT. BRIEF PERIODS OF
LAKE ENHANCED SNOW AT IWD AND AT NWS MQT HAVE RESULTED IN A LIGHT
COATING OF SNOW. IR LOOP SHOWED THE BACK EDGE OF THE LOW CLOUDS TO
NEAR THE MN/DAKOTAS BORDER.
&&

.DISCUSSION...

TODAY AND TONIGHT...EXPECT SCT/NMRS LIGHT LAKE EFFECT SNOW SHOWERS
TO CONTINUE FOR LOCATIONS FAVORED BY NNW FLOW. THE RELATIVELY SHORT
FETCH LENGTH INTO THE WEST WILL LIMIT ACCUMULATION POTENTIAL. THE
LOCAL HIGH RES WRF/ARW SUGGESTS THAT UPSTREAM CONDITIONING FROM LAKE
NIPIGON AND SLIGHTLY MORE N THAN NNW FLOW MAY SUPPORT LES BANDS INTO
NORTH CENTRAL UPPER MI. THE LATER ARRIVAL OF THE COLD AIR INTO THE
EAST TIL THE AFTER THE MOISTURE DEPARTS WILL ALSO BE UNFAVORABLE FOR
ANY SIGNIFICANT ACCUMULATIONS. THE LES SHOULD DIMINISH DURING THE
AFTERNOON AS 800-700 MB DRYING MOVE IN. OVERALL...GIVEN THE LACK OF
SYNOPTIC SCALE UPWARD MOTION WITH THE MARGINAL INSTABILITY...ONLY
MINOR ACCUMULATIONS OF AN INCH OR LESS ARE EXPECTED.

TONIGHT...ANY REMAINING LES WILL GRADUALLY END AS SFC AND MID LEVEL
RIDGING BUILD INTO THE THE REGION WITH ACYC FLOW AND INVERSION
HEIGHTS FALLING TO AROUND 3K FT. WITH FAVORABLE RADIATIONAL COOLING
CONDITIONS INLAND OVERNIGHT...MIN TEMPS WILL FALL INTO THE MID TEENS
WHILE LAKE CLOUDS KEEP TEMPS INT THE MID 20S EAST.

MONDAY INTO TUE...MDLS WERE IN REASONABLE AGREEMENT WITH A NRN
STREAM SHORTWAVE TROUGH MOVING INTO MANITOBA MON AND THROUGH NRN
ONTARIO EARLY TUE WHICH WILL DRAG A COLD FRONT THROUGH LAKE
SUPERIOR. WITH LITTLE MOISTURE AVAILABLE ONLY WEAK DYNAMICS ON
THE SRN TAIL OF THE SHRTWV...NO MEASURABLE PCPN IS EXPECTED. WITH SW
LOW LEVEL WAA AND SUNSHINE AHEAD OF THE TROUGH ON MON...TEMPS WILL
REBOUND INTO THE UPPER 30S TO AROUND 40. WITH ONLY MODERATE CAA
BEHIND THE FRONT AND A RELATIVELY DRY AIRMASS 850 MB TEMPS TO AROUND
-6C WILL NOT BE LOW ENOUGH TO PRODUCE LES. PCPN ASSOCIATED WITH THE
CUTOFF LOW ALSO WILL REMAIN EAST OF THE AREA TUE AS DRY NRLY FLOW
(PWAT DOWN TO NEAR 0.10 INCH) DOMINATES THE AREA.

WED THROUGH SAT...THE GFS/ECMWF/GEM WERE CONSISTENT IN SHOWING TREND
TOWARD TROUGHING INTO THE CNTRL CONUS AS A RIDGE BUILDS OVER THE ERN
PACIFIC. WITH THIS PATTERN...COLDER WILL MOVE INTO THE GREAT LAKES
WITH POTENTIAL FOR SOME LES. TIMING IS UNCERTAIN...BUT GFS/ECMWF
CONSENSUS SUGGESTS THAT A SHORTWAVE WILL MOVE THROUGH THU WITH 850 MB
TEMPS FALLING TO NEAR -13C BY LATE THU INTO THU NIGHT. EVEN THOUGH
THIS SHOULD PROVIDE ENOUGH INSTABILITY FOR LES...FCST DRY 850-700 MB
MOISTURE WILL BE UNFAVORABLE FOR SIGNIFICANT ACCUMULATIONS. A
PROGRESSIVE NRN STREAM FLOW WOULD LEAD TO WAA FRI INTO SAT WITH
RECOVERING TEMPS AND MAINLY DRY WEATHER.
&&

.AVIATION...
GUSTY NORTH TO NORTHWEST FLOW WILL KEEP MVFR CIGS AT ALL TERMINALS
THROUGH THIS EVENING. ALTHOUGH THERE HAVE BEEN LAKE EFFECT SNOW
SHOWERS...THE BEST HAVE BEEN EAST OF SAWYER WITH VERY FEW AT CMX AND
IWD. WITH MVFR TYPE CIGS AS FAR WEST AS FARGO...IT WILL TAKE SOME
TIME FOR CLEARING TO MOVE INTO UPPER MICHIGAN. IN FACT...VFR CIGS
WILL PROBABLY NOT OCCUR UNTIL MIDNIGHT OR AFTER FOR THE REGION AS
THE HIGH BUILDS IN. THE HIGH SHIFTS SOUTHEAST OF THE AREA ON MONDAY
ALLOWING FOR SOUTHERLY WINDS TO DEVELOP AHEAD OF ANOTHER WEAK COLD
FRONT.
&&

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

EXPECT N TO NW WINDS UP TO 30 KTS WITH A FEW GALE FORCE GUSTS TO 35
KTS TO DIMINISH THIS AFTERNOON WITH THE APPROACH OF HI PRES FROM
MINNESOTA. LIGHT WINDS TONIGHT WITH THE PASSAGE OF THE HI WILL GIVE
WAY TO A STRONGER SW FLOW ON MON AS THE PRES GRADIENT SHARPENS
BETWEEN THE HI DRIFTING INTO THE LOWER LAKES AND ANOTHER APPROACHING
COLD FRONT. LOOK FOR A WSHFT TO THE N BEHIND THIS FRONT ON MON NIGHT
AND STRENGTHENING WINDS MAINLY OVER THE E HALF INTO TUE ON THE NW
FLANK OF A DEEP LO PRES MOVING THRU THE LOWER GREAT LAKES INTO
ONTARIO. DEPENDING ON HOW FAR W THIS LO DRIFTS...N GALES TO 35 KTS
ARE POSSIBLE OVER PORTIONS OF THE E HALF. THE STRONGER WINDS WILL
DIMINISH TUE NIGHT THRU WED WITH THE APPROACH OF ANOTHER HI PRES
SYSTEM...BUT A STRONGER NW FLOW WILL DEVELOP ON THU IN THE WAKE OF
ANOTHER COLD FROPA.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$


UPDATE...MRD

SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...MRD
MARINE...KC








AREA FORECAST DISCUSSION

NWS GAYLORD MI

 1127 AM EST SUN NOV 27 2011

.SYNOPSIS.../ISSUED AT 1126 AM/

A COLD FRONT HAS DELIVERED A COOLER AIR MASS TO NORTHERN MICHIGAN.
LIGHT RAIN AND SNOW WILL GRADUALLY END FROM WEST TO EAST THIS
AFTERNOON. SOME LIGHT LAKE EFFECT RAIN OR RAIN/SNOW MIX WILL
DEVELOP TONIGHT...BUT PRECIPITATION AMOUNTS WILL BE VERY LIGHT. THERE
WILL BE A BRIEF BREAK FROM PRECIPITATION MONDAY...BUT THEN
PRECIPITATION CHANCES WILL RETURN TUESDAY...MAINLY SOUTHEAST OF
GAYLORD. TEMPERATURES WILL BE SEASONABLY COLD THIS UPCOMING WEEK.

TL/JH

&&

.SHORT TERM.../ISSUED AT 1126 AM/...THIS AFTERNOON

...LIGHT SYNOPTIC RAIN/SNOW WILL GRADUALLY END WITH A MUCH MORE
SEASONABLE AIR MASS NOW IN PLACE...

ALL UPDATED PUBLIC PRODUCTS AND RER`S HAVE POSTED. SEE CLIMATE
SECTION.

HIGHLY AMPLIFIED BUT SLOWLY PROGRESSIVE FLOW IS OVER THE CONUS. THE
MERIDIONAL UPPER TROF /NESTLED BETWEEN 2 SUBTROPICAL RIDGES/ HAS
ADVANCED FROM THE PLAINS TOWARD THE MS RIVER VALLEY IN THE PAST 24
HRS...WITH ITS WAVELENGTH DECREASING. THIS TROF WILL BEGIN
BIFURCATING TODAY WITH THE PORTION AFFECTING THE GTLKS REMAINING
PROGRESSIVE.

THE ASSOCIATED ANABATIC COLD FRONT WAS E OF THE FCST AREA...
EXTENDING FROM A 1002 MB LOW S OF JAMES BAY...TO LAKE HURON...TO
THE THUMB. NNW WINDS UP TO 30 KTS WILL CONTINUE ADVECTING COOLER
SEASONABLE AIR IN THE AREA.

SYNOPTIC PCPN: BACK EDGE OF PCPN SHIELD HAS CHANGED OVER TO SNOW AND
WILL END FROM NW TO SE THIS AFTN WITH NO ACCUM.

88D CORRELATION COEFFICIENT SHOWS R/S LINE PROGRESSING SEWD...
CONFIRMED BY TRANSITION HERE AT OFFICE AND SPOTTER REPORTS.

BACK EDGE OF PCPN LINES UP WITH DEEP MSTR. SO ONCE -SN ENDS THE DGZ
DRIES OUT PER RUC FCST SOUNDINGS. SO EXPECT PCPN TO END OVER NRN
LOWER. SHOULD SEE CHANGOVER TO -SN ALL THE WAY TO LAKE HURON/SAGINAW
BAY. UPSTREAM PIREPS CONFIRM SATL AND 12Z 700 CHART MID-LEVEL
DRYING. CLOUD TOPS ARE 4-6K FT UPSTREAM.

LAKE EFFECT PCPN: THE MQT 88D IS ALREADY SHOWING LAKE DEVELOPMENT ON
SUPERIOR AS LOW-LEVEL THERMAL PROFILE /INSTABILITY/ IS SUPPORTIVE.
IT WILL TAKE UNTIL 21Z FOR CAA TO ADVECT FAVORABLE LAPSE RATES INTO
NW LOWER. HOWEVER...FRONTAL INVERSION WILL CAP LAKE CLOUDS TO 850 MB.
AM NOT EXPECTING MUCH MORE THAN WIDESPREAD CLOUDS AS THE DGZ NEVER
RE-SATURATES.

IT WILL BE MOIST UP TO 850. SO NW FLOW INTO HIGHER TERRAIN SHOULD
PRODUCE SOME DRIZZLE.

OVER THE EASTERN U.P. EXPECTED R SHWRS TO POSSIBLY MIX WITH SNOW
LATE...AS INVERSION DEEPENS JUST ENOUGH TO ICE CRYSTALS TO DEVELOP.
BUT IT MAY NOT BE ENUF FOR SNOW.

THIS HAS NECESSITATED CHANGES TO THE FCST ISSUED AT 403 AM. BROUGHT
SNOW TO AN END AS DEEP MSTR DEPARTS...AND CHANGED R TO S BEFORE
ENDING SE OF GAYLORD. ALL LAKE PCPN OVER THE U.P. HAS BEEN CHANGED
FROM S TO A R/S MIX. ALL SNOW HAS BEEN REMOVED FROM THE FCST FOR NRN
LOWER. WHAT MINISCULE SNOWFALL AMTS WERE FCST HAVE BEEN ZERO`D OUT.

TEMPS WILL CONTINUE FALLING ANOTHER 4-7F ALONG LAKE HURON/SAGINAW
BAY. ELSEWHERE...TEMPS WILL HOLD STEADY THE REST OF THE DAY.


DUAL POL PCPN ESTIMATES: THIS IS OUR FIRST PCPN EVENT SINCE
RETURNING TO SERVICE WITH DUAL POL. OVERALL PCPN ESTIMATES ARE
SUPERIOR TO THE LEGACY ALGORITHM. LEGACY WAS GENERALLY TOO LOW.
THE MAIN DISAGREEMENT WAS OVER BENZIE/MANISTEE COUNTIES WHERE AN
AVERAGE OF THE TWO WAS THE BEST. DUAL POL ACCUMULATION WAS WAY TO
HIGH BY UP TO 2 TIMES...MOST LIKELY DUE TO MELTING ISSUES.

HALBLAUB

&&

.LONG TERM.../ISSUED AT 417 AM/...TONIGHT AND BEYOND

SOME QUIETER WX FOR A DAY OR SO...AS HIGH PRESSURE WEDGES IN
OVERHEAD BETWEEN SYSTEMS IN THE DEEP SOUTH AND UP BY HUDSON BAY.
MODELS HAVE TRENDED WESTWARD WITH THE EJECTING SOUTHERN LOW BY
TUESDAY...AND AS THE PREVIOUS SHIFT NOTED WE MAY GET CLIPPED BY THE
BROAD PRECIP SHIELD NW OF THIS SYSTEM...PERHAPS AS SOON AS LATE
MONDAY NIGHT. PRECIP TRENDS (INCLUDING PRECIP TYPE) ARE THE MAIN
CONCERN.

MODELS...HEY...ANOTHER TWO-CAMP SOLUTION. THIS TIME THE GFS/UKMET
ARE IN A MORE NORTHERLY CAMP WITH THE EJECTING SOUTHERN UPPER LOW
(EASTERN OHIO TUESDAY EVENING)...WHICH WOULD RESULT IN WETTER WX
HERE. THE OPERATIONAL GFS OFFERS THE MOST DIRE SOLUTION.
MEANWHILE...THE NAM...ECMWF...AND GEM ARE MORE SOUTHERLY (TN/NC/VA
BORDER AREA) AND DRIER. HPC RECOMMENDS HEDGING OUR BETS WITH A
GFS/ECMWF COMPROMISE...WHICH SEEMS A REASONABLE APPROACH UNTIL
THINGS GETS FURTHER NAILED DOWN.

TONIGHT/MONDAY...MODELS HAVE TRENDED COLDER TONIGHT...WITH 850MB
TEMPS OF -9C LINGERING TO AROUND MIDNIGHT (DELTA T/S 15-16). WILL
ADJUST POPS TONIGHT HIGHER...WITH A SMALL AREA OF LIKELY POPS IN
BOTH PENINSULAS IN NW/NNW SNOWBELTS. AM A LITTLE CONCERNED WE COULD
MANAGE SOME SNEAKY 1-2 INCH ACCUMS...ESPECIALLY GIVEN THE SOLID
SUPERIOR CONNECTION INTO NW LOWER. BUT WE WON/T HAVE MUCH TIME FOR
CONVECTION TO RECOVER/REORGANIZE AFTER DIURNAL DISRUPTIONS...BEFORE
THE 850MB THERMAL TROF LIFTS OUT TO THE NE OVERNIGHT. BY 12Z...850MB
TEMPS WILL BE DOWN TO THE -4/-5C RANGE...AND THERE SHOULDN/T BE ANY
PRECIP LEFT FOR MONDAY. SKIES WILL TEND TO CLEAR MONDAY...WITH HIGH
PRESSURE OVERHEAD AND A NARROW WEDGE OF SHARP SUBSIDENCE (850-700MB
RH GOES BELOW 20 PERCENT). SOME MID/HIGH CLOUDS WILL LINGER NEAR
SAGINAW BAY.

MIN TEMPS IN THE 20S TONIGHT...WITH SOME UPPER TEENS POSSIBLE IN
INTERIOR SECTIONS OF NE LOWER MI. MAX TEMPS UPPER 30S TO AROUND 40F.

MONDAY NIGHT/TUESDAY...A NORTHERN STREAM SHORTWAVE WILL MAKE
EASTWARD PROGRESS ACROSS NORTHERN MN MONDAY NIGHT...AND THEN WILL
WASH OUT AS THE LARGER CIRCULATION TO THE SOUTH AND SE TAKES OVER.
BAND OF F-GEN AND ASSOCIATED MID CLOUDS AHEAD OF THIS WAVE WILL
REACH EASTERN UPPER MI BY DAWN TUESDAY...PRODUCING VIRGA AND MAYBE A
FLURRY.

THE BIGGER CONCERN IS THE DEEP LOW TO THE SOUTH. MODEL DIFFS ARE
RELATIVELY MINOR THRU 12Z TUESDAY...WITH RAIN DEFINITELY MOVING INTO
SE LOWER MI...AND NAM/GFS BOTH TRY TO BACK UP PRECIP TOWARD SAGINAW
BAY. WILL MAINTAIN A CHANCE OF RAIN IN THE SE ZONES (ALL PRECIP
LIQUID THERE...WITH 850MB TEMPS 3-4C...AND SURFACE TEMPS IN THE MID
30S. ALL MODELS CONTINUE TO SLOWLY EXPAND PRECIP NORTHWARD AS THE
UPPER LOW LOVES UP THE TN VALLEY AND CENTRAL APPALACHIANS. WILL
BOOST AND EXPAND POPS...WITH LIKELY POPS ALONG/SE OF HTL-APN...AND
CATEGORICAL NEAR TAWAS/STANDISH. THIS WILL ALMOST ALL LIQUID...WITH
ABOVE FREEZING 850MB AND SURFACE TEMPS IN MOST OF THE PRECIP AREA.
HOWEVER...ALONG THE OUTER EDGE OF THE PRECIP SHIELD...850MB TEMPS
WILL DROP SLIGHTLY BELOW ZERO...AND THE SURFACE-BASED WARM LAYER
WILL SHRINK BELOW 1K FEET. WILL MENTION A RAIN/SNOW MIX ALONG THE NW
EDGE (MANISTEE TO CHEBOYGAN).

MIN TEMPS UPPER 20S TO AROUND 30 IN MOST PLACES...EXCEPT LOW/MID 30S
FAR SE. MAX TEMPS MID 30S TO LOWER 40S.

REST OF THE FORECAST...FORECAST RAPIDLY TURNS MORE INTERESTING TUE
NIGHT. AS THE SURFACE LOW PASSES BY TO THE EAST...COLD
ADVECTION FROM 850MB ON DOWN WILL RAPIDLY TURN PRECIP FROM RAIN TO
SNOW. PRECIP WILL BE DWINDLING LATE TUE NIGHT AND OUT OF THE PICTURE
COMPLETELY BY MIDDAY WEDNESDAY. WILL INCREASE POPS TUESDAY
NIGHT...INCLUDING ADDING SOME LIKELY POPS IN NE LOWER (RAIN/SNOW MIX
IN THE EVENING...ALL SNOW OVERNIGHT). SNOW POTENTIAL VARIES GREATLY
FROM MODEL TO MODEL...AS THEY DIFFER ON BOTH PRECIP PRODUCTION (GFS
IS QUITE WET...UP TO AN INCH OF QPF TUE NIGHT IN NE LOWER)...AND ON
HOW QUICKLY TO TURN PRECIP TO SNOW. CERTAINLY POTENTIAL IS THERE FOR
MODERATE (ADVISORY-LEVEL) ACCUMS...PERHAPS EVEN MORE IN A WORST-CASE
SCENARIO.

JZ

&&

.MARINE.../ISSUED AT 1126 AM/

AT 11 AM...ADDED THE STRAITS TO THE SCA. OTHERWISE ALL OTHER SCA
HEADLINES REMAIN AS IS FROM 405 AM ISSUANCE.

COLD FRONT HAS EXITED THE WATERS SURROUDNING NRN MI. NW- NNW
GUSTS WILL CONTINUE 25-30KT IN MOST PLACES WELL.

HALBLAUB

WINDS WILL DIMINISH LATE TONIGHT INTO MONDAY AS HIGH PRESSURE
BRIEFLY SETTLES INTO THE LAKES REGION.

JZ

&&

.AVIATION.../ISSUED AT 642 AM/...VALID FOR 12Z TAFS

LOW PRESSURE NE OF THE SAULT WILL CONTINUE TO MOVE NE AWAY FROM THE
REGION. THE ASSOCIATED COLD FRONT WAS MOVING OFF THE LAKE HURON
COAST. RAIN WILL DIMINISH TODAY...THOUGH SOME LAKE EFFECT SHRA/SHSN
COULD IMPACT THE TAF SITES NEAR LAKE MI (ESPECIALLY TVC) LATE THIS
AFTERNOON THRU THIS EVENING. CIGS WILL SLOWLY IMPROVE AS THE DAY
PROCEEDS...AND WILL BE LARGELY MVFR...THOUGH COULD DRIP IFR AT TIMES
EARLY THIS MORNING. CIGS WILL BECOME MAINLY VFR BY LATE TONIGHT...AS
HIGH PRESSURE BRIEFLY BUILDS IN.

JZ

&&

.CLIMATE.../ISSUED AT 1126 AM/

RECORDS: ALL LONG-TERM CLIMATE SITES EXCEPT SSM SET/TIED THE WARMEST
LOW TEMPS ON RECORD YESTERDAY.

APN 45F (OLD RECORD 41 IN 1948)
GLR 46F (OLD RECORD 39 IN 2009)
HTL 48F (OLD RECORD 43 IN 2006)
TVC 50F (TIED OLD RECORD 50 IN 1915)

HALBLAUB

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR LHZ345-347-348.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR LMZ323-342-
     344>346.
LS...SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR LSZ321.

&&

$$

WFO APX






AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 1022 AM EST SUN NOV 27 2011

.UPDATE...
IT HAS BEEN A STRUGGLE TO SEE LES DEVELOPMENT THIS MORNING...MOST
LIKELY DUE TO THE VERY STRONG SUBSIDENCE INVERSION NOTED ON THE 12Z
INL SOUNDING AND NEUTRAL TO JUST SLIGHTLY CYCLONIC PBL FLOW. HAVE
SEEN SOME BETTER BANDING BETWEEN MARQUETTE AND MUNISING IN THE LAST
FEW HOURS MOST LIKELY OWED TO SLIGHT ENHANCEMENT FROM LAKE NIPIGON
AND FROM BEING ON THE WESTERN EDGE OF THE MID LEVEL CLOUDS. WITH
THAT BEING SAID...HAVE RAISED POPS THIS MORNING IN WESTERN ALGER
COUNTY TO CATEGORICAL AND ALSO RAISED ACCUMULATIONS TO UP TO 3
INCHES WELL INLAND OF LAKE SUPERIOR. IF NOTHING ELSE...SOME
UNTREATED ROADS WILL BECOME A LITTLE SLIPPERY IN THIS AREA ALONG THE
M-94 CORRIDOR BETWEEN SKANDIA AND WETMORE.

OTHERWISE...WITH THE DRY AIR AND BUILDING HEIGHTS MOVING INTO
WESTERN UPPER MI BY THIS AFTN...HAVE OPTED TO JUST GO WITH SCATTERED
SNOW SHOWERS FOR THE REMAINDER OF THE DAY IN THIS AREA.

IN ADDITION...TEMPS WILL STRUGGLE TO RISE MUCH TODAY DUE TO CLOUD
COVER AND COLD ADVECTION. WILL GENERALLY GO WITH STEADY TEMPS IN THE
UPPER 20S WEST AND MID 30S EAST.
&&

PREV DISCUSSION...ISSUED AT 625 AM EST SUN NOV 27 2011...

.SYNOPSIS /ISSUED AT 442 AM/...
WV IMAGERY AND RUC ANALYSIS INDICATED A HIGH AMPLITUDE PATTERN WITH
A MID/UPPER LEVEL RIDGE OVER THE WRN CONUS AND A TROUGH OVER THE
CNTRL CONUS FROM NW ONTARIO TO CNTRL TX. THE BACK EDGE OF THE DEEPER
MOISTURE WAS MOVING STEADILY EASTWARD AND WAS NEAR A INL-MSP LINE.
AT THE SFC...LOW PRES NE OF LAKE SUPERIOR CONTINUED TO LIFT OFF TO
THE NE THROUGH NRN ONTARIO. CAA IN THE WAKE OF THE LOW HAD DROPPED
850 MB TEMPS TO NEAR -10C OVER WRN LAKE SUPERIOR. EVEN THOUGH
KINL/CYPL SOUNDINGS INDICATED A MOISTURE PROFILE THROUGH LOW AND MID
LEVELS FAVORABLE FOR LAKE EFFECT SNOW...WITH ONLY MARGINAL
INSTABILITY (LK-H8 DELTA/T TO 15C)AND THE CLOUD LAYER BLO THE DGZ
LAYER (10K-14K FT) SNOW HAS BEEN RELATIVELY LIGHT. BRIEF PERIODS OF
LAKE ENHANCED SNOW AT IWD AND AT NWS MQT HAVE RESULTED IN A LIGHT
COATING OF SNOW. IR LOOP SHOWED THE BACK EDGE OF THE LOW CLOUDS TO
NEAR THE MN/DAKOTAS BORDER.
&&

.DISCUSSION...

TODAY AND TONIGHT...EXPECT SCT/NMRS LIGHT LAKE EFFECT SNOW SHOWERS
TO CONTINUE FOR LOCATIONS FAVORED BY NNW FLOW. THE RELATIVELY SHORT
FETCH LENGTH INTO THE WEST WILL LIMIT ACCUMULATION POTENTIAL. THE
LOCAL HIGH RES WRF/ARW SUGGESTS THAT UPSTREAM CONDITIONING FROM LAKE
NIPIGON AND SLIGHTLY MORE N THAN NNW FLOW MAY SUPPORT LES BANDS INTO
NORTH CENTRAL UPPER MI. THE LATER ARRIVAL OF THE COLD AIR INTO THE
EAST TIL THE AFTER THE MOISTURE DEPARTS WILL ALSO BE UNFAVORABLE FOR
ANY SIGNIFICANT ACCUMULATIONS. THE LES SHOULD DIMINISH DURING THE
AFTERNOON AS 800-700 MB DRYING MOVE IN. OVERALL...GIVEN THE LACK OF
SYNOPTIC SCALE UPWARD MOTION WITH THE MARGINAL INSTABILITY...ONLY
MINOR ACCUMULATIONS OF AN INCH OR LESS ARE EXPECTED.

TONIGHT...ANY REMAINING LES WILL GRADUALLY END AS SFC AND MID LEVEL
RIDGING BUILD INTO THE THE REGION WITH ACYC FLOW AND INVERSION
HEIGHTS FALLING TO AROUND 3K FT. WITH FAVORABLE RADIATIONAL COOLING
CONDITIONS INLAND OVERNIGHT...MIN TEMPS WILL FALL INTO THE MID TEENS
WHILE LAKE CLOUDS KEEP TEMPS INT THE MID 20S EAST.

MONDAY INTO TUE...MDLS WERE IN REASONABLE AGREEMENT WITH A NRN
STREAM SHORTWAVE TROUGH MOVING INTO MANITOBA MON AND THROUGH NRN
ONTARIO EARLY TUE WHICH WILL DRAG A COLD FRONT THROUGH LAKE
SUPERIOR. WITH LITTLE MOISTURE AVAILABLE ONLY WEAK DYNAMICS ON
THE SRN TAIL OF THE SHRTWV...NO MEASURABLE PCPN IS EXPECTED. WITH SW
LOW LEVEL WAA AND SUNSHINE AHEAD OF THE TROUGH ON MON...TEMPS WILL
REBOUND INTO THE UPPER 30S TO AROUND 40. WITH ONLY MODERATE CAA
BEHIND THE FRONT AND A RELATIVELY DRY AIRMASS 850 MB TEMPS TO AROUND
-6C WILL NOT BE LOW ENOUGH TO PRODUCE LES. PCPN ASSOCIATED WITH THE
CUTOFF LOW ALSO WILL REMAIN EAST OF THE AREA TUE AS DRY NRLY FLOW
(PWAT DOWN TO NEAR 0.10 INCH) DOMINATES THE AREA.

WED THROUGH SAT...THE GFS/ECMWF/GEM WERE CONSISTENT IN SHOWING TREND
TOWARD TROUGHING INTO THE CNTRL CONUS AS A RIDGE BUILDS OVER THE ERN
PACIFIC. WITH THIS PATTERN...COLDER WILL MOVE INTO THE GREAT LAKES
WITH POTENTIAL FOR SOME LES. TIMING IS UNCERTAIN...BUT GFS/ECMWF
CONSENSUS SUGGESTS THAT A SHORTWAVE WILL MOVE THROUGH THU WITH 850 MB
TEMPS FALLING TO NEAR -13C BY LATE THU INTO THU NIGHT. EVEN THOUGH
THIS SHOULD PROVIDE ENOUGH INSTABILITY FOR LES...FCST DRY 850-700 MB
MOISTURE WILL BE UNFAVORABLE FOR SIGNIFICANT ACCUMULATIONS. A
PROGRESSIVE NRN STREAM FLOW WOULD LEAD TO WAA FRI INTO SAT WITH
RECOVERING TEMPS AND MAINLY DRY WEATHER.
&&

.AVIATION /FOR THE 12Z TAF ISSUANCE/...

EXPECT MVFR CIGS TO PREDOMINATE THRU THE DAY ALONG WITH SOME -SHSN
AS GUSTY NW WINDS BLOW COLDER AIR ACROSS THE RELATIVELY WARM WATERS
OF LK SUP AND MAINTAIN MOIST LYR UNDER LLVL INVERSION. THE APRCH OF
HI PRES TNGT AND MUCH DRIER LLVL AIR WILL ALLOW AN IMPROVEMENT TO
VFR CONDITIONS AND CAUSE THE GUSTY WINDS TO DIMINISH.
&&

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

EXPECT N TO NW WINDS UP TO 30 KTS WITH A FEW GALE FORCE GUSTS TO 35
KTS TO DIMINISH THIS AFTERNOON WITH THE APPROACH OF HI PRES FROM
MINNESOTA. LIGHT WINDS TONIGHT WITH THE PASSAGE OF THE HI WILL GIVE
WAY TO A STRONGER SW FLOW ON MON AS THE PRES GRADIENT SHARPENS
BETWEEN THE HI DRIFTING INTO THE LOWER LAKES AND ANOTHER APPROACHING
COLD FRONT. LOOK FOR A WSHFT TO THE N BEHIND THIS FRONT ON MON NIGHT
AND STRENGTHENING WINDS MAINLY OVER THE E HALF INTO TUE ON THE NW
FLANK OF A DEEP LO PRES MOVING THRU THE LOWER GREAT LAKES INTO
ONTARIO. DEPENDING ON HOW FAR W THIS LO DRIFTS...N GALES TO 35 KTS
ARE POSSIBLE OVER PORTIONS OF THE E HALF. THE STRONGER WINDS WILL
DIMINISH TUE NIGHT THRU WED WITH THE APPROACH OF ANOTHER HI PRES
SYSTEM...BUT A STRONGER NW FLOW WILL DEVELOP ON THU IN THE WAKE OF
ANOTHER COLD FROPA.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

UPDATE...MRD

SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...KC
MARINE...KC







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 625 AM EST SUN NOV 27 2011

UPDATED AVIATION DISCUSSION FOR 12Z TAFS

.SYNOPSIS /ISSUED AT 442 AM/...
WV IMAGERY AND RUC ANALYSIS INDICATED A HIGH AMPLITUDE PATTERN WITH
A MID/UPPER LEVEL RIDGE OVER THE WRN CONUS AND A TROUGH OVER THE
CNTRL CONUS FROM NW ONTARIO TO CNTRL TX. THE BACK EDGE OF THE DEEPER
MOISTURE WAS MOVING STEADILY EASTWARD AND WAS NEAR A INL-MSP LINE.
AT THE SFC...LOW PRES NE OF LAKE SUPERIOR CONTINUED TO LIFT OFF TO
THE NE THROUGH NRN ONTARIO. CAA IN THE WAKE OF THE LOW HAD DROPPED
850 MB TEMPS TO NEAR -10C OVER WRN LAKE SUPERIOR. EVEN THOUGH
KINL/CYPL SOUNDINGS INDICATED A MOISTURE PROFILE THROUGH LOW AND MID
LEVELS FAVORABLE FOR LAKE EFFECT SNOW...WITH ONLY MARGINAL
INSTABILITY (LK-H8 DELTA/T TO 15C)AND THE CLOUD LAYER BLO THE DGZ
LAYER (10K-14K FT) SNOW HAS BEEN RELATIVELY LIGHT. BRIEF PERIODS OF
LAKE ENHANCED SNOW AT IWD AND AT NWS MQT HAVE RESULTED IN A LIGHT
COATING OF SNOW. IR LOOP SHOWED THE BACK EDGE OF THE LOW CLOUDS TO
NEAR THE MN/DAKOTAS BORDER.
&&

.DISCUSSION...

TODAY AND TONIGHT...EXPECT SCT/NMRS LIGHT LAKE EFFECT SNOW SHOWERS
TO CONTINUE FOR LOCATIONS FAVORED BY NNW FLOW. THE RELATIVELY SHORT
FETCH LENGTH INTO THE WEST WILL LIMIT ACCUMULATION POTENTIAL. THE
LOCAL HIGH RES WRF/ARW SUGGESTS THAT UPSTREAM CONDITIONING FROM LAKE
NIPIGON AND SLIGHTLY MORE N THAN NNW FLOW MAY SUPPORT LES BANDS INTO
NORTH CENTRAL UPPER MI. THE LATER ARRIVAL OF THE COLD AIR INTO THE
EAST TIL THE AFTER THE MOISTURE DEPARTS WILL ALSO BE UNFAVORABLE FOR
ANY SIGNIFICANT ACCUMULATIONS. THE LES SHOULD DIMINISH DURING THE
AFTERNOON AS 800-700 MB DRYING MOVE IN. OVERALL...GIVEN THE LACK OF
SYNOPTIC SCALE UPWARD MOTION WITH THE MARGINAL INSTABILITY...ONLY
MINOR ACCUMULATIONS OF AN INCH OR LESS ARE EXPECTED.

TONIGHT...ANY REMAINING LES WILL GRADUALLY END AS SFC AND MID LEVEL
RIDGING BUILD INTO THE THE REGION WITH ACYC FLOW AND INVERSION
HEIGHTS FALLING TO AROUND 3K FT. WITH FAVORABLE RADIATIONAL COOLING
CONDITIONS INLAND OVERNIGHT...MIN TEMPS WILL FALL INTO THE MID TEENS
WHILE LAKE CLOUDS KEEP TEMPS INT THE MID 20S EAST.

MONDAY INTO TUE...MDLS WERE IN REASONABLE AGREEMENT WITH A NRN
STREAM SHORTWAVE TROUGH MOVING INTO MANITOBA MON AND THROUGH NRN
ONTARIO EARLY TUE WHICH WILL DRAG A COLD FRONT THROUGH LAKE
SUPERIOR. WITH LITTLE MOISTURE AVAILABLE ONLY WEAK DYNAMICS ON
THE SRN TAIL OF THE SHRTWV...NO MEASURABLE PCPN IS EXPECTED. WITH SW
LOW LEVEL WAA AND SUNSHINE AHEAD OF THE TROUGH ON MON...TEMPS WILL
REBOUND INTO THE UPPER 30S TO AROUND 40. WITH ONLY MODERATE CAA
BEHIND THE FRONT AND A RELATIVELY DRY AIRMASS 850 MB TEMPS TO AROUND
-6C WILL NOT BE LOW ENOUGH TO PRODUCE LES. PCPN ASSOCIATED WITH THE
CUTOFF LOW ALSO WILL REMAIN EAST OF THE AREA TUE AS DRY NRLY FLOW
(PWAT DOWN TO NEAR 0.10 INCH) DOMINATES THE AREA.

WED THROUGH SAT...THE GFS/ECMWF/GEM WERE CONSISTENT IN SHOWING TREND
TOWARD TROUGHING INTO THE CNTRL CONUS AS A RIDGE BUILDS OVER THE ERN
PACIFIC. WITH THIS PATTERN...COLDER WILL MOVE INTO THE GREAT LAKES
WITH POTENTIAL FOR SOME LES. TIMING IS UNCERTAIN...BUT GFS/ECMWF
CONSENSUS SUGGESTS THAT A SHORTWAVE WILL MOVE THROUGH THU WITH 850 MB
TEMPS FALLING TO NEAR -13C BY LATE THU INTO THU NIGHT. EVEN THOUGH
THIS SHOULD PROVIDE ENOUGH INSTABILITY FOR LES...FCST DRY 850-700 MB
MOISTURE WILL BE UNFAVORABLE FOR SIGNIFICANT ACCUMULATIONS. A
PROGRESSIVE NRN STREAM FLOW WOULD LEAD TO WAA FRI INTO SAT WITH
RECOVERING TEMPS AND MAINLY DRY WEATHER.
&&

.AVIATION /FOR THE 12Z TAF ISSUANCE/...

EXPECT MVFR CIGS TO PREDOMINATE THRU THE DAY ALONG WITH SOME -SHSN
AS GUSTY NW WINDS BLOW COLDER AIR ACROSS THE RELATIVELY WARM WATERS
OF LK SUP AND MAINTAIN MOIST LYR UNDER LLVL INVERSION. THE APRCH OF
HI PRES TNGT AND MUCH DRIER LLVL AIR WILL ALLOW AN IMPROVEMENT TO
VFR CONDITIONS AND CAUSE THE GUSTY WINDS TO DIMINISH.
&&

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

EXPECT N TO NW WINDS UP TO 30 KTS WITH A FEW GALE FORCE GUSTS TO 35
KTS TO DIMINISH THIS AFTERNOON WITH THE APPROACH OF HI PRES FROM
MINNESOTA. LIGHT WINDS TONIGHT WITH THE PASSAGE OF THE HI WILL GIVE
WAY TO A STRONGER SW FLOW ON MON AS THE PRES GRADIENT SHARPENS
BETWEEN THE HI DRIFTING INTO THE LOWER LAKES AND ANOTHER APPROACHING
COLD FRONT. LOOK FOR A WSHFT TO THE N BEHIND THIS FRONT ON MON NIGHT
AND STRENGTHENING WINDS MAINLY OVER THE E HALF INTO TUE ON THE NW
FLANK OF A DEEP LO PRES MOVING THRU THE LOWER GREAT LAKES INTO
ONTARIO. DEPENDING ON HOW FAR W THIS LO DRIFTS...N GALES TO 35 KTS
ARE POSSIBLE OVER PORTIONS OF THE E HALF. THE STRONGER WINDS WILL
DIMINISH TUE NIGHT THRU WED WITH THE APPROACH OF ANOTHER HI PRES
SYSTEM...BUT A STRONGER NW FLOW WILL DEVELOP ON THU IN THE WAKE OF
ANOTHER COLD FROPA.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$


SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...KC
MARINE...KC






AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 442 AM EST SUN NOV 27 2011

.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A HIGH AMPLITUDE PATTERN WITH
A MID/UPPER LEVEL RIDGE OVER THE WRN CONUS AND A TROUGH OVER THE
CNTRL CONUS FROM NW ONTARIO TO CNTRL TX. THE BACK EDGE OF THE DEEPER
MOISTURE WAS MOVING STEADILY EASTWARD AND WAS NEAR A INL-MSP LINE.
AT THE SFC...LOW PRES NE OF LAKE SUPERIOR CONTINUED TO LIFT OFF TO
THE NE THROUGH NRN ONTARIO. CAA IN THE WAKE OF THE LOW HAD DROPPED
850 MB TEMPS TO NEAR -10C OVER WRN LAKE SUPERIOR. EVEN THOUGH
KINL/CYPL SOUNDINGS INDICATED A MOISTURE PROFILE THROUGH LOW AND MID
LEVELS FAVORABLE FOR LAKE EFFECT SNOW...WITH ONLY MARGINAL
INSTABILITY (LK-H8 DELTA/T TO 15C)AND THE CLOUD LAYER BLO THE DGZ
LAYER (10K-14K FT) SNOW HAS BEEN RELATIVELY LIGHT. BRIEF PERIODS OF
LAKE ENHANCED SNOW AT IWD AND AT NWS MQT HAVE RESULTED IN A LIGHT
COATING OF SNOW. IR LOOP SHOWED THE BACK EDGE OF THE LOW CLOUDS TO
NEAR THE MN/DAKOTAS BORDER.
&&

.DISCUSSION...

TODAY AND TONIGHT...EXPECT SCT/NMRS LIGHT LAKE EFFECT SNOW SHOWERS TO
CONTINUE FOR LOCATIONS FAVORED BY NNW FLOW. THE RELATIVELY SHORT
FETCH LENGTH INTO THE WEST WILL LIMIT ACCUMULATION POTENTIAL.
THE LOCAL HIGH RES WRF/ARW SUGGESTS THAT UPSTREAM CONDITIONING FROM
LAKE NIPIGON AND SLIGHTLY MORE N THAN NNW FLOW MAY SUPPORT LES BANDS
INTO NORTH CENTRAL UPPER MI. THE LATER ARRIVAL OF THE COLD AIR
INTO THE EAST TIL THE AFTER THE MOISTURE DEPARTS WILL ALSO BE
UNFAVORABLE FOR ANY SIGNIFICANT ACCUMULATIONS. THE LES SHOULD
DIMINISH DURING THE AFTERNOON AS 800-700 MB DRYING MOVE IN.
OVERALL...GIVEN THE LACK OF SYNOPTIC SCALE UPWARD MOTION WITH THE
MARGINAL INSTABILITY...ONLY MINOR ACCUMULATIONS OF AN INCH OR LESS
ARE EXPECTED.

TONIGHT...ANY REMAINING LES WILL GRADUALLY END AS SFC AND MID LEVEL
RIDGING BUILD INTO THE THE REGION WITH ACYC FLOW AND INVERSION
HEIGHTS FALLING TO AROUND 3K FT. WITH FAVORABLE RADIATIONAL COOLING
CONDITIONS INLAND OVERNIGHT...MIN TEMPS WILL FALL INTO THE MID TEENS
WHILE LAKE CLOUDS KEEP TEMPS INT THE MID 20S EAST.

MONDAY INTO TUE...MDLS WERE IN REASONABLE AGREEMENT WITH A NRN
STREAM SHORTWAVE TROUGH MOVING INTO MANITOBA MON AND THROUGH NRN
ONTARIO EARLY TUE WHICH WILL DRAG A COLD FRONT THROUGH LAKE
SUPERIOR. WITH LITTLE MOISTURE AVAILABLE ONLY WEAK DYNAMICS ON
THE SRN TAIL OF THE SHRTWV...NO MEASURABLE PCPN IS EXPECTED. WITH SW
LOW LEVEL WAA AND SUNSHINE AHEAD OF THE TROUGH ON MON...TEMPS WILL
REBOUND INTO THE UPPER 30S TO AROUND 40. WITH ONLY MODERATE CAA
BEHIND THE FRONT AND A RELATIVELY DRY AIRMASS 850 MB TEMPS TO AROUND
-6C WILL NOT BE LOW ENOUGH TO PRODUCE LES. PCPN ASSOCIATED WITH THE
CUTOFF LOW ALSO WILL REMAIN EAST OF THE AREA TUE AS DRY NRLY FLOW
(PWAT DOWN TO NEAR 0.10 INCH) DOMINATES THE AREA.

WED THROUGH SAT...THE GFS/ECMWF/GEM WERE CONSISTENT IN SHOWING TREND
TOWARD TROUGHING INTO THE CNTRL CONUS AS A RIDGE BUILDS OVER THE ERN
PACIFIC. WITH THIS PATTERN...COLDER WILL MOVE INTO THE GREAT LAKES
WITH POTENTIAL FOR SOME LES. TIMING IS UNCERTAIN...BUT GFS/ECMWF
CONSENSUS SUGGESTS THAT A SHORTWAVE WILL MOVE THROUGH THU WITH 850 MB
TEMPS FALLING TO NEAR -13C BY LATE THU INTO THU NIGHT. EVEN THOUGH
THIS SHOULD PROVIDE ENOUGH INSTABILITY FOR LES...FCST DRY 850-700 MB
MOISTURE WILL BE UNFAVORABLE FOR SIGNIFICANT ACCUMULATIONS. A
PROGRESSIVE NRN STREAM FLOW WOULD LEAD TO WAA FRI INTO SAT WITH
RECOVERING TEMPS AND MAINLY DRY WEATHER. &&

.AVIATION /FOR THE 06Z TAF ISSUANCE/...

LOW PRESSURE OVER EASTERN LAKE SUPERIOR WILL CONTINUE TO LIFT NE
REACHING ONTARIO LATER TONIGHT. THE ADVECTION OF COLDER/DRIER LOW
LEVEL AIR INTO THE AREA IN THE WAKE OF THIS SYSTEM SHOULD ALLOW FOR
SLOW IMPROVEMENT TO MVFR CONDITIONS AT ALL SITES LATER TONIGHT INTO
SUNDAY. THE COLDER AIR WILL ALSO CAUSE ANY LIGHT RAIN TO CHANGE OVER
SNOW OVERNIGHT AT KCMX AND KIWD. INCREASED MIXING WILL ALLOW N-NW
WINDS TO GUST AOA 25 KTS AT TIMES ON SUNDAY.
&&

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

EXPECT N TO NW WINDS UP TO 30 KTS WITH A FEW GALE FORCE GUSTS TO 35
KTS TO DIMINISH THIS AFTERNOON WITH THE APPROACH OF HI PRES FROM
MINNESOTA. LIGHT WINDS TONIGHT WITH THE PASSAGE OF THE HI WILL GIVE
WAY TO A STRONGER SW FLOW ON MON AS THE PRES GRADIENT SHARPENS
BETWEEN THE HI DRIFTING INTO THE LOWER LAKES AND ANOTHER APPROACHING
COLD FRONT. LOOK FOR A WSHFT TO THE N BEHIND THIS FRONT ON MON NIGHT
AND STRENGTHENING WINDS MAINLY OVER THE E HALF INTO TUE ON THE NW
FLANK OF A DEEP LO PRES MOVING THRU THE LOWER GREAT LAKES INTO
ONTARIO. DEPENDING ON HOW FAR W THIS LO DRIFTS...N GALES TO 35 KTS
ARE POSSIBLE OVER PORTIONS OF THE E HALF. THE STRONGER WINDS WILL
DIMINISH TUE NIGHT THRU WED WITH THE APPROACH OF ANOTHER HI PRES
SYSTEM...BUT A STRONGER NW FLOW WILL DEVELOP ON THU IN THE WAKE OF
ANOTHER COLD FROPA.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$


SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...VOSS
MARINE...KC







AREA FORECAST DISCUSSION

NWS TWIN CITIES/CHANHASSEN MN

 346 PM CST SUN NOV 27 2011

.DISCUSSION...

SUMMARY...LARGELY DRY FORECAST WITH ONLY SMALL POPS IN THE
FORECAST FOR THURSDAY AND NEXT SUNDAY. THREE COLD FRONTS MOVE
THROUGH OVER THE NEXT 7 DAYS...MONDAY NIGHT...WEDNESDAY
NIGHT...AND SATURDAY NIGHT. SLIGHTLY ABOVE NORMAL TEMPS ARE
EXPECTED AHEAD OF THESE BOUNDARIES MONDAY...WEDNESDAY AND
SATURDAY. NEAR NORMAL OR SLIGHTLY BELOW NORMALS TEMPS ARE
EXPECTED BEHIND THE FRONTAL PASSAGES ON TUESDAY...
THURSDAY...FRIDAY AND SUNDAY.

TONIGHT AND TOMORROW...TRICKY TEMP FORECAST: STATUS DECK HAS BEEN
VERY SLOW TO CLEAR TODAY AND CONTINUES MOVING TO THE EAST AT JUST
7KTS. WITHIN THE LAST HOUR OR SO...WE`RE FINALLY SEEING SOME
THINNING OF THE DECK IN MN. THIS MIGHT BE A SIGN THAT THE CLEARING
IS A BIT FASTER THAN WHAT`S IN THE FORECAST FOR TONIGHT.
HOWEVER...WE WILL LOSE OUR SUN HERE IN THE NEXT COUPLE HOURS...SO
KEPT THE SLOW CLEARING TREND IN THE FORECAST TONIGHT. MIGHT HAVE
TO WAIT FOR THE RIDGE AXIS TO PASS OVERHEAD...WHICH WOULD MATCH UP
FAIRLY WELL WITH THE 925MB RH OFF THE RUC THIS EVENING. THE CLOUDS
WILL OBVIOUSLY HAVE LARGE IMPACT ON THE TEMPERATURES TONIGHT. KEPT
WEST CENTRAL WI IN THE MID 20S AND EVEN LEFT MOST OF THE METRO IN
THE LOWER TO MID 20S. AREAS THAT GET AT 3-4 HOURS OF CLEAR SKIES
TOMORROW MORNING...WILL LIKELY GET INTO THE TEENS FOR LOWS.
OTHERWISE...THE MERCURY WILL BE HEAD THE OTHER WAY TOMORROW WITH
WARM AIR ADVECTION KICKING IN BETWEEN 06-12Z TONIGHT. SOUTHWEST
WINDS WITH MIXING UP TO 975-925MB OFF THE FORECAST SOUNDINGS WOULD
GIVE US LOW TO MID 40S ALMOST EVERYWHERE TOMORROW. IN
FACT...DOWNSLOPING OFF THE BUFFALO RIDGE IN WESTERN MN SHOULD
YIELD 50S FOR HIGHS. COLD FRONT PASSES THROUGH FROM NW TO SE LATE
TOMORROW AFTERNOON AND TOMORROW EVENING. MIGHT BE A MID DECK OF
CLOUDS WITH THE FRONT BUT NO PRECIPITATION IS EXPECTED.

TUESDAY THROUGH THURSDAY...-4 TO -6 C AT 850MB INDICATING A COOL
DOWN FOR TUESDAY BEHIND THE FRONT BUT CERTAINLY NOTHING OUT OF THE
ORDINARY. THE COOL DOWN WILL BE BRIEF WITH 1000-500MB THICKNESS
ALREADY CLIMBING BETWEEN 540M-546M EARLY WEDNESDAY. ANOTHER FRONT
MOVES THROUGH WEDNESDAY NIGHT AND WITH THIS BOUNDARY THERE MIGHT
BE JUST ENOUGH FORCING AND MOISTURE TO SHAKE OUT A FEW SNOW FLAKES
IN THE STRATO CUMULUS IN THE WAKE OF THE FRONT ON THURSDAY. BOTH
THE 27.12Z GFS/ECMWF HAVE A FEW TENTHS OF SNOW ACCUMULATION ACROSS
CENTRAL MN AND WESTERN WI.

EXTENDED...NO MAJOR SYSTEMS OUT ON THE HORIZON. WOULDN`T BE
SURPRISED IF WE END UP WITH A LITTLE PRECIP NEXT SUNDAY BASED ON
THE PATTERN INDICATED BY THE ECMWF AND TO A LESSER DEGREE THE
LATEST GFS ENSEMBLE. CPC IS FORECASTING BELOW NORMAL TEMPERATURES
FOR MUCH OF THE COUNTRY IN THE 6-14 DAY OUTLOOKS. ALTHOUGH THE
SIGNAL ISN`T QUITE AS STRONG IN MN/WI...IT FINALLY APPEARS WE
SHOULD GET INTO A MORE WINTER-LIKE AIR MASS AFTER NEXT WEEKEND.

&&

.AVIATION.../18Z TAF ISSUANCE/

BACK EDGE OF MVFR CIGS MVG EAST PAINFULLY SLOW...LESS THAN 10 KTS.
PIREPS SHOWING CLOUDS 1500 TO 2000 FEET THICK. SLOWED DOWN CLEARING
FROM PRESENT TAFS A BIT..TYING CLEARING TREND TO THE SURFACE RIDGE
LINE. SEE SPECIFIC TAFS FOR TIMING. SURFACE PRESSURE GRADIENT
REMAINS FAIRLY TIGHT ...SHUD SEE GUSTS AROUND 20 KTS MSP AND WI TAFS
UNTIL AROUND 21Z. WINDS BECOMING LIGHT AS RIDGE MOVES ACROSS AND
THEN S TO SW FOR MONDAY AHEAD OF CDFNT.

KMSP...CIGS 2500 TO 3000 FEET THRU ABOUT 01Z AND THEN CLOUDS
BECOMING SCT AS SURFACE RIDGE MOVES INTO AREA.  WINDS REMAINING NW
INTO THE EARLY EVENING WITH GUSTS 20 KTS UNTIL 21Z.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

$$

BAP/CLF







AREA FORECAST DISCUSSION...UPDATED

NWS ST LOUIS MO

 926 PM CST MON NOV 28 2011

.UPDATE...
/926 PM CST MON NOV 28 2011/

RADAR TRENDS ARE SHOWING SOME INCREASE CURRENTLY OVER THE EASTERN
OZARKS. DO NOT EXPECT ADDITIONAL AMOUNTS OF SNOW AND SLEET TO BE
MUCH MORE THAN A HALF INCH AS VISIBILITIES AT OBSERVATION SITES
ARE NOT DROPPING MUCH AND THERE IS NO SIGNIFICANT COOLING ON IR
IMAGERY. RUC AND OTHER MODELS SOUNDINGS ARE SHOWING SOME WEAK
WARMING THROUGH A DEEP LAYER THE REST OF THE NIGHT AT THE SAME
TIME ASCENT WILL WEAKEN. TOTAL SNOW AND SLEET AMOUNTS IN THE FAR
SOUTHERN CWA STILL LOOK LIKE THEY WILL BE 1 TO 2 INCHES WITH
AMOUNTS DROPPING OFF QUICKLY TO THE NORTH. REST OF THE FORECAST
STILL LOOK GOOD.

BRITT

&&

.DISCUSSION...
/341 PM CST MON NOV 28 2011/

UPPER LOW CUT OFF LATE LAST NIGHT OVER SE AR AND DURING THE DAY
TODAY SYSTEM HAS BEGUN TO PIVOT TO THE NORTHEAST...PERHAPS JUST A
BIT FURTHER E THAN FORECAST BY EARLIER NWP OUTPUT.  NO QUESTION THAT
THIS SYSTEM WILL BRING PRECIPITATION TO SE SECTIONS OF THE CWA
OVER THE NEXT 24 HOURS...AS LATEST MODEL RUNS CONTINUE TO SUPPORT
EARLIER THINKING THAT VERY MOIST AIRMASS WILL BE UNDERGOING STRONG
ISENTROPIC ASCENT AS IT WRAPS AROUND THE NORTH SIDE OF THE LOW FROM
THE OHIO VALLEY INTO SE MO.  ISENTROPIC PROGS INDICATE THAT THERE
WILL BE AN EXTREMELY TIGHT POP GRADIENT/SHARP CUTOFF IN PRECIP ON
THE WESTERN EDGE OF THE PRECIP SHIELD...AND FOR NOW WE`RE HOLDING
ONTO THE THINKING THAT THIS EDGE WILL BE JUST EAST OF A IJX-VIH
LINE.  ANY SMALL WOBBLE IN THE TRACK OF THE SYSTEM MAY CAUSE A
FAIRLY BIG ADJUSTMENT TO THE POPS IN THIS CORRIDOR.

BIGGEST CONCERN FOR AREA IS PTYPE...AND 12Z UA DATA INDICATED AMS
LOCKED TO THE WEST OF THE SYSTEM WAS JUST A BIT COOLER THAN
SUGGESTED BY EARLIER RUNS. THERE COULD BE A MIX OF PTYPES EARLY
THIS EVENING WITH THE INITIAL ONSET OF THE PRECIP...BUT THE
INTENSE NATURE OF THE PROGGED WAA ACROSS AREA CERTAINLY SUGGESTS
THAT WARM AIR WILL OVERWHELM COLUMN AND AS A RESULT MOST OF THE
PRECIP FROM MID EVENING ON WILL FALL IN THE FORM OF RAIN. THE
EXCEPTION TO THIS IS THE E OZARKS...WHERE FORECAST SOUNDINGS DO
INDICATE THAT POCKET OF LOW LEVEL COLD AIR IS GOING TO STUBBORNLY
HOLD ON. IN THIS AREA...PRIMARILY ALONG AND SOUTH OF A STE
GENEVIEVE...POTOSI LINE...HAVE CONTINUED TO A MENTION OF SNOW AND
SLEET ALONG WITH THE RAIN THROUGHOUT THE NIGHT. ANY ACCUMULATIONS
SHOULD BE MINOR BUT CERTAINLY NOT OUT OF THE QUESTION...ESPECIALLY
IF DYNAMIC COOLING CAN DROP TEMPS ENOUGH IN A LOCALIZED AREA.

PRECIP WINDS DOWN FROM EASTERN MO INTO S CENTRAL IL DURING THE DAY
ON TUE...WITH THE BULK OF THE PRECIP EAST OF THE MISSISSIPPI RIVER
BY MIDDAY.  THE DECREASE OF THE WAA AS THE SYSTEM PUSHES INTO THE
LOWER GREAT LAKES DOES ALLOW AMS OVER AREA TO BEGIN TO COOL ONCE
AGAIN...BUT FOR THE MOST PART IT LOOKS LIKE PRECIP WILL BE SHUTTING
DOWN BY THE TIME THERMAL PROFILES WOULD SUPPORT A MIX AND/OR A
CHANGEOVER TO ALL SNOW.  SO...OTHER THAN CONTINUING A MENTION OF
SOME LINGERING LIGHT SNOW IN THE AFOREMENTIONED POCKET OF COOL AIR
OVER THE OZARKS...HAVE MAINTAINED ALL RAIN IN THE FORECASTS FOR TUE.

TRANQUIL WEATHER WILL RETURN FOR MID WEEK WITH TEMPS REBOUNDING TO
NEAR OR JUST ABOVE THE 50 DEGREE MARK OVER S MO ON
THURSDAY...ALTHOUGH A DRY COLD FRONTAL PASSAGE SHOULD KNOCK DAYTIME
TEMPS BACK INTO THE 30S AND 40S BY FRIDAY.

NEXT SYSTEM SHOULD BEGIN TO PUSH OUT OF THE WESTERN U.S. AND INTO
THE PLAINS LATE SATURDAY-SUNDAY TIME FRAME...WITH PRECIP RETURNING
TO THE AREA DURING THIS TIME.  SOME QUESTION AS TO WHAT THE PTYPE
MAY BE...BUT FOR NOW HAVE GONE WITH A BROAD-BRUSH RAIN/SNOW MIX AND
WILL FINE-TUNE AS WE GET CLOSER TO EVENT.

GKS/TRUETT

&&

.AVIATION...
/523 PM CST MON NOV 28 2011/

INITIALLY MVFR CIGS AT KCOU/KUIN SHOULD PERSIST FOR AT LEAST THE
NEXT COUPLE OF HOURS WITH A FAIR AMOUNT OF UNCERTAINTY THEREAFTER.
SATELLITE IMAGERY SHOWS THAT THE EROSION ON THE WRN EDGE OF THE
CLOUD SHIELD HAS SLOWED OVER THE PAST FEW HOURS WHILE A SFC LOW
OVER IL WAS ALSO RETROGRADING INTO THE AREA. THIS SET OF TAFS IS
OPTIMISTIC WITH CIG IMPROVEMENT AFTER 03-04Z HOWEVER IT IS
POSSIBLE THAT NOCTURNAL COOLING AND THE APPROACHING SFC LOW COULD
KEEP MVFR CONDITIONS IN PLACE FOR SEVERAL MORE HOURS...ESPECIALLY
AT KUIN. REGARDLESS OF WHAT HAPPENS OVERNIGHT...CIGS SHOULD
IMPROVE RAPIDLY TOMORROW AS THE LOW PRESSURE CENTER MOVES AWAY
FROM THE AREA. NWLY WINDS INCREASE TONIGHT AS THE PRESSURE GRADIENT
TIGHTENS.

SPECIFICS FOR KSTL AND KSUS...RADAR IMAGERY AT TAF ISSUANCE SHOWED
THAT PCPN WAS IMMINENT AT KSTL/KSUS. THERE COULD BE A BRIEF PERIOD
OF RAIN MIXED WITH SLEET OR SNOW EARLY TONIGHT BEFORE INCREASING
WAA ALOFT TURNS EVERYTHING TO RAIN. MVFR CIGS ARE EXPECTED TO
PERSIST THROUGH THE NIGHT WITH MINOR IMPROVEMENT NEAR SUNRISE
FOLLOWED BY RAPID IMPROVEMENT LATE TOMORROW AFTN AS THE LOW
PRESSURE CENTER PULLS AWAY. NWLY WINDS INCREASE TONIGHT AS THE
PRESSURE GRADIENT TIGHTENS.

KANOFSKY

&&

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

$$

WFO LSX







AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

 303 PM CST SUN NOV 27 2011

.DISCUSSION...

Short Term (Tonight-Tuesday Night)...

A subtle northwest wind shift has helped dislodge the clearing line
which has been anchored over ern KS and ern NE since yesterday
afternoon. Eastward advancement has picked up the last several
hours, and should slow somewhat this evening, but ultimately clear
the eastern CWA before daybreak.

As winds diminish tonight, expect we`ll end up with one of the
coldest nights to date over the western half of the CWA where upper
teens are possible in the NW sheltered regions and the low-mid 20s
elsewhere.

It should be noted that some extremely dry boundary layer air exists
over central Kansas into Nebraska with dewpoints below zero in some
areas. This airmass will spread eastward tomorrow, and have manually
adjusted gridded dwpt/RH fields to account for anomalously low
readings during the afternoon. Light to calm winds should keep fire
danger to a minimum, especially after the rainfall on Friday.
Otherwise, a rather chilly day in store with limited mixing as an
elongated surface ridge axis shifts overhead.

Models continue to indicate a low level density surge pushing
southeast across the area early Tuesday morning, with a very strong
isobar packing in its wake, accentuated by strong cyclogenesis over
the southeast states. For lack of a better description, this
secondary cold front, trailed by a 1035mb surface high, will usher
in another reinforcing shot of cold air and strong winds for
Tuesday. Much like Saturday, it will feel pretty brutal with
temperatures struggling to reach 40 degrees with wind gusts
frequently reaching 30-35 mph.

Bookbinder

Medium Range (Wednesday through Sunday)...

The main forecast concern in the extended time frame will be the
chance for precipitation and precipitation type on Saturday night.

Wednesday-Friday...models in good agreement through the period.
Wednesday, a surface ridge of high pressure will dominate the region
keeping conditions dry. On Thursday, an upper level low will be
digging southward along the west coast. In response, upstream upper
level ridging will exist over the Southern Plains and into the
Midwest keeping conditions dry as a weak cold front drops through
the forecast area. On Friday, the upper level ridge flattens out as
a upper level trough drops down from the Northern Plains into the
Upper Midwest. Precipitation with this system however, will remain
north of the forecast area.

Saturday-Sunday...Model solutions begin to differ as to the
progression of the west coast trough. The 00Z EC has flip-flopped
with the 12Z GFS becoming the more progressive solution. On
Saturday, the EC takes a closed upper low over the extreme
southwestern CONUS and opens it into a upper trough as it moves out
into the central and southern Rockies by Saturday night. WAA will
draw moisture northward into the forecast area out ahead of a
associated surface cold front. The EC develops showers ahead of the
front with the chance for a mix of rain and snow showers behind the
front. The EC then moves this system east of the forecast area with
high pressure building in behind it on Sunday. The GFS is slower and
further south with the upper level low as it has it digging further
south than the EC into the Baja on Saturday. By Sunday, the closed
low moves into the southwestern CONUS with precipitation remaining
well south and west of the forecast area. To account for the EC
solution have chance pops for Saturday night across the forecast
area changing to a rain/snow mix behind the cold front.

73

&&

.AVIATION...

Borderline MVFR/VFR stratus deck hasn`t moved 5 miles from when I
arrived on shift at 4PM yesterday, and when I left at midnight this
morning. 900-875mb layered RH field in the RUC continues to have the
best handle on this deck, with a gradual expected improvement
between 21-23Z as a subtle 20 degree backing of the wind upstream
across ern Nebraska should result in a slight eastward nudge prior
to sunset.

Otherwise, northwest winds were beginning to lose their gusty
character and will slowly diminish toward sunset, and then rapidly
abate to a light northwest winds at less than 5 knots overnight into
the day Monday with clear skies.

Bookbinder

&&

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

$$

WFO EAX











AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

 1119 AM CST SUN NOV 27 2011

...UPDATED AVIATION DISCUSSION...

.DISCUSSION...

Main challenges for the next few days will be temperatures with an
upper pattern that remains fairly complex across the CONUS.

Today - Tonight:

Temperatures today will likely be slow to recover from their minimal
diurnal range due to cloud cover from moisture trapped underneath a
slow moving upper wave. Low to mid level stratus should hang on
across the area through the mid to late morning hours and then
begin to shift east with the axis of the upper wave, allowing
stronger subsidence and drier air can move in and help to clear
things out. Couple the slower retreat of cloud cover with continued
northerly/northwesterly winds advecting slightly cooler air and
temperatures today look to be stuck in the lower 40s/near 40 for most
areas.

For tonight, skies are expected to clear out with a weak surface
ridge nosing into northwestern Missouri. With dewpoints likely to
fall into the teens overnight, decent radiational cooling should
occur and parts of far northwestern Missouri should be able to fall
into the mid to upper teens. Elsewhere across the forecast area,
winds that don`t completely go calm may keep the boundary layer
mixed enough to keep lows in the low to mid 20s.

Monday - Tuesday:

The upper low will continue to spin to our south and east as another
wave begins to move southeast out of the northern Rockies and Plains
Monday evening/night. With this wave moving through the upper ridge
it leads to a brief raising of thicknesses and heights across the
area. This should allow for temperatures to warm back to more
seasonal readings, especially across the western forecast area. High
temperatures will range from the upper 40s across our west to the
lower 40s in our east as result. This secondary wave will send a
reinforcing shot of cooler air into the region. Fortunately the
airmasses associated with these recent waves have been of a maritime
origin and as a result we really only cool back down into the
lower 40s for Tuesday.

Wednesday - Saturday:

Another wave will move overtop the eastern Pacific upper ridge
Wednesday and Thursday. Models are actually somewhat consistent in
breaking this wave apart and sending the northern portion across the
Great Lakes and pinching off the southern portion into the
Southwestern CONUS. This pretty much leaves our area dry, although
we may see increased cloud cover as there is fair amount of
vorticity that remains between the two main waves. Strong maritime
high pressure reinforces the airmass already in place and as a
result we continue to see a good likelihood of below normal
temperatures through the end of the week. By Saturday however, that
high pressure should have moved to our southeast with winds
returning to southerly/southwesterly direction. This should result
in another modest warm with temperatures returning to near seasonal
levels by Saturday afternoon.

CDB

&&

.AVIATION...

Borderline MVFR/VFR stratus deck hasn`t moved 5 miles from when I
arrived on shift at 4PM yesterday, and when I left at midnight this
morning. 900-875mb layered RH field in the RUC continues to have the
best handle on this deck, with a gradual expected improvement
between 21-23Z as a subtle 20 degree backing of the wind upstream
across ern Nebraska should result in a slight eastward nudge prior
to sunset.

Otherwise, northwest winds were beginning to lose their gusty
character and will slowly diminish toward sunset, and then rapidly
abate to a light northwest winds at less than 5 knots overnight into
the day Monday with clear skies.

Bookbinder

&&

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

$$

WFO EAX









AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

 311 AM CST Sun Nov 27 2011

.DISCUSSION...

Main challenges for the next few days will be temperatures with an
upper pattern that remains fairly complex across the CONUS.

Today - Tonight:

Temperatures today will likely be slow to recover from their minimal
diurnal range due to cloud cover from moisture trapped underneath a
slow moving upper wave. Low to mid level stratus should hang on
across the area through the mid to late morning hours and then
begin to shift east with the axis of the upper wave, allowing
stronger subsidence and drier air can move in and help to clear
things out. Couple the slower retreat of cloud cover with continued
northerly/northwesterly winds advecting slightly cooler air and
temperatures today look to be stuck in the lower 40s/near 40 for most
areas.

For tonight, skies are expected to clear out with a weak surface
ridge nosing into northwestern Missouri. With dewpoints likely to
fall into the teens overnight, decent radiational cooling should
occur and parts of far northwestern Missouri should be able to fall
into the mid to upper teens. Elsewhere across the forecast area,
winds that don`t completely go calm may keep the boundary layer
mixed enough to keep lows in the low to mid 20s.

Monday - Tuesday:

The upper low will continue to spin to our south and east as another
wave begins to move southeast out of the northern Rockies and Plains
Monday evening/night. With this wave moving through the upper ridge
it leads to a brief raising of thicknesses and heights across the
area. This should allow for temperatures to warm back to more
seasonal readings, especially across the western forecast area. High
temperatures will range from the upper 40s across our west to the
lower 40s in our east as result. This secondary wave will send a
reinforcing shot of cooler air into the region. Fortunately the
airmasses associated with these recent waves have been of a maritime
origin and as a result we really only cool back down into the
lower 40s for Tuesday.

Wednesday - Saturday:

Another wave will move overtop the eastern Pacific upper ridge
Wednesday and Thursday. Models are actually somewhat consistent in
breaking this wave apart and sending the northern portion across the
Great Lakes and pinching off the southern portion into the
Southwestern CONUS. This pretty much leaves our area dry, although
we may see increased cloud cover as there is fair amount of
vorticity that remains between the two main waves. Strong maritime
high pressure reinforces the airmass already in place and as a
result we continue to see a good likelihood of below normal
temperatures through the end of the week. By Saturday however, that
high pressure should have moved to our southeast with winds
returning to southerly/southwesterly direction. This should result
in another modest warm with temperatures returning to near seasonal
levels by Saturday afternoon.

CDB

&&

.AVIATION...

There has been no net eastward movement to the VFR stratus deck this
evening as deep cyclonic flow persists ahead of elongated upper
trough axis. Based on RUC 875mb RH progs, have pushed back clearing
all the way until 15Z.

Winds will remain gusty from the north-northwest, peaking at 25 to
30 knots for the next several hours with only the slightest of
diminishing trends through the day with a general 15G25KT character.
Winds will rapidly diminish between 23 and 00Z with sunset and a
building high pressure ridge.

Bookbinder

&&

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

$$









AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

 1124 PM CST SAT NOV 26 2011

...UPDATED AVIATION DISCUSSION...

.DISCUSSION...

Short Range (Tonight through Monday)...

Radar and surface observations this afternoon show that the cold
front, that was moving through the region this morning, has cleared
the eastern boundary of our forecast area, with showers still
lingering across central Missouri. The cooler air behind the front
did not waste anytime surging south, as temperatures have continued
to wallow around in the 40s across the region this afternoon. Cloud
cover has been slow to clear behind the front due to the amount of
moisture trapped in the base of the parent trough that is the driving
force behind the cold front. Despite clear skies in central Kansas,
thoughts are that we will have to wait till sometime Sunday morning
for clouds to begin clearing out given the progress of the trough.

Conditions Sunday will be more typical of late November weather than
what we experienced over the past work week. The cooler air behind
the front will stay in place across the region even as the clouds
clear. Pressure gradient wind, and boundary layer mixing after
sunrise Sunday, will keep winds rather gusty through much of the
day. The breezy conditions should abate by the evening hours as a
surface ridge slides east across Kansas and Missouri, allowing the
wind to go light and variable late Sunday night into Monday morning.
Have pushed Sunday night/Monday morning lows down as a result as
guidance numbers look too warm given clear skies, light winds, and
forecast 850mb temperatures around -2C.

For the rest of Monday, the trough that moved through earlier this
weekend will have bombed out into a cutoff low across the lower half
of the Mississippi River Valley. Much of the activity related to
this features will be to our south and east though, leaving clear
skies and slightly warmer -near normal- temperatures prevailing
through the day.

Cutter


Medium Range (Tuesday through Saturday)...

Not much in the way of forecast concerns in the extended period as
temperatures are expected to be seasonable during the period with
the next chance of precipitation not until Saturday.

Tuesday, a weak cold front will push through the forecast area.
Although fropa will be dry, the front will drop high temperatures to
around 40 to the mid 40s. A surface ridge of high pressure will move
through the region on Wednesday. This will bring a return to
southwest flow across the forecast area and warm highs a few
degrees. On Thursday another weak and dry cold front will move
through the area. However, a more interesting feature of note is an
upper level trough digging southward along the west coast. In
response to the digging trough, a ridge will develop in the Plains
and Midwest states. On Friday a cut off low develops in the base of
the west coast trough. Meanwhile another upper level trough moving
from the Northern Plains into the Great Lakes region will flatten
the ridge across the forecast area. At the surface a Canadian high
builds into the region keeping temperatures slightly below average
on Friday with highs ranging from the mid 30s to the lower 40s.
Model solutions diverge as to the evolution of the cut off low in
the southwest on Saturday. The GFS is much more progressive bringing
the cut off upper low out into the Southern Plains developing
showers across the forecast area out ahead of it. The ECMWF is
slower with the upper low keeping it over the southwestern CONUS. To
account for the more progressive GFS solution have include slight
chance pops for Saturday.

73


&&

.AVIATION...

There has been no net eastward movement to the VFR stratus deck this
evening as deep cyclonic flow persists ahead of elongated upper
trough axis. Based on RUC 875mb RH progs, have pushed back clearing
all the way until 15Z.

Winds will remain gusty from the north-northwest, peaking at 25 to
30 knots for the next several hours with only the slightest of
diminishing trends through the day with a general 15G25KT character.
Winds will rapidly diminish between 23 and 00Z with sunset and a
building high pressure ridge.

Bookbinder

&&

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

$$

WFO EAX











AREA FORECAST DISCUSSION

NWS BUFFALO NY

 541 PM EST SUN NOV 27 2011

.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL MOVE INTO THE REGION TONIGHT WITH A
PERIOD OF RAIN. THE RAIN WILL LINGER INTO MONDAY MORNING BEFORE
TAPERING TO WIDELY SCATTERED LIGHT SHOWERS BY AFTERNOON AS THE FRONT
WEAKENS IN PLACE. AN AREA OF LOW PRESSURE WILL THEN LIFT ACROSS THE
LOWER LAKES TUESDAY AND TUESDAY NIGHT WITH MORE RAIN...WHICH MAY END
AS A LITTLE WET SNOW ON WEDNESDAY AS COOLER AIR FILTERS INTO THE
REGION. DRY WEATHER WILL RETURN ON THURSDAY BEFORE COLDER AIR
ARRIVES FRIDAY INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
REGIONAL RADAR IMAGERY THIS AFTERNOON SHOWS AN INITIAL BATCH OF
SHOWERS LIFTING ACROSS WESTERN NEW YORK WITH A FEW SPRINKLES ALSO
CROSSING THE EASTERN LAKE ONTARIO REGION. THIS FIRST BATCH OF RAIN
WILL BE VERY LIGHT...AND THE HIGH RESOLUTION HRRR MODEL AND RADAR
TRENDS CONTINUE TO SUGGEST THERE WILL BE A RELATIVE LULL IN SHOWER
ACTIVITY THIS EVENING BETWEEN THIS INITIAL BATCH AND A MORE SOLID
AREA OF RAIN FORECAST TO DEVELOP BY MID TO LATE EVENING ACROSS
WESTERN NEW YORK. TEMPERATURES HAVE SOARED THIS AFTERNOON IN
RESPONSE TO DEEP SOUTHERLY FLOW...WITH UPPER 50S INLAND AND LOWER
60S ON THE LAKE PLAINS DUE TO ADDED COMPRESSIONAL WARMING FROM
DOWNSLOPE FLOW. TEMPS WILL ONLY SLOWLY PULL BACK THIS EVENING AS WE
REMAIN ON THE WARM SIDE OF THE FRONTAL BOUNDARY.

FOR TONIGHT...A COMPLEX TROUGH OVER THE MID SECTION OF THE NATION
WILL SPLIT OVERNIGHT...WITH NORTHERN STREAM ENERGY ACCELERATING EAST
ACROSS QUEBEC...WHILE THE SOUTHERN STREAM ENERGY IS LEFT BEHIND TO
EVOLVE INTO A CLOSED LOW OVER THE LOWER MISSISSIPPI VALLEY. AN
ASSOCIATED COLD FRONT WILL ADVANCE SLOWLY EASTWARD INTO THE REGION
OVERNIGHT...THEN STALL AND WASH OUT ON MONDAY AS THE LOW LEVEL FLOW
QUICKLY EVOLVES INTO A COL BETWEEN THE TWO MID LEVEL CLOSED LOWS.
PWAT OF 1-1.25 INCHES IS AVAILABLE ALONG AND AHEAD OF THIS FRONT...
WHICH IS 2-3 STANDARD DEVIATIONS ABOVE AVERAGE FOR LATE NOVEMBER.
MAIN FORCING MECHANISMS WILL BE FRONTOGENESIS AND CONVERGENCE IN THE
800-700MB LAYER ALONG THE ADVANCING FRONT...AND UPPER LEVEL
DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 140 KNOT UPPER LEVEL
JET.

WITH THE DEEP LAYER FRONTAL ASCENT AND AMPLE SUPPLY OF MOISTURE
WIDESPREAD RAIN ALONG THE FRONTAL BOUNDARY IS A CERTAINTY...THE MAIN
FORECAST CHALLENGE IS THE PLACEMENT AND TIMING WITH A SHARP EASTERN
CUTOFF TO THE STEADIER RAIN. EXPECT THE STEADIER RAIN TO MAKE IT
INTO WESTERN NY DURING THE MID TO LATE EVENING AND THE NORTH COUNTRY
AS WELL BY LATE EVENING...AFTER THAT IT WILL ONLY MAKE VERY SLOW
PROGRESS EASTWARD TOWARDS THE GENESEE VALLEY AND FINGER LAKES. MANY
AREAS IN CENTRAL NY ALONG THE BORDER WITH THE BGM CWA MAY REMAIN DRY
UNTIL LATE TONIGHT. AS FAR AS RAINFALL AMOUNTS GO...EXPECT BASIN
AVERAGE OF A QUARTER TO A THIRD OF AN INCH ACROSS WESTERN NY AND THE
NORTH COUNTRY...WITH MUCH LESS ACROSS THE FINGER LAKES.

MONDAY MORNING EXPECT RAIN TO STILL BE QUITE WIDESPREAD ACROSS MUCH
OF THE REGION AT SUNRISE. THE STEADIER RAIN WILL QUICKLY TAPER OFF
DURING THE MORNING AS FRONTAL CONVERGENCE BREAKS DOWN DUE TO THE
LOSS OF MID LEVEL FLOW WITHIN THE DEVELOPING COL REGION. THERE WILL
BE PLENTY OF LOW CLOUDS AROUND IN THE WEAK NORTHERLY UPSLOPE FLOW
BEHIND THE WASHING OUT FRONTAL BOUNDARY...SO THIS WILL LIKELY ALLOW
LIGHT SHOWERS AND DRIZZLE TO LINGER INTO THE EARLY AFTERNOON. LATER
IN THE DAY EXPECT MUCH OF THE AREA TO BE DRY...ALTHOUGH WITH THE
LINGERING FRONTAL BOUNDARY NEARBY CANNOT RULE OUT A FEW LIGHT
SHOWERS ESPECIALLY FROM THE SOUTHERN TIER INTO THE FINGER LAKES.

WESTERN AND CENTRAL NY WILL BE ON THE COOL SIDE OF THE BOUNDARY BY
MONDAY...AND THAT COMBINED WITH PLENTY OF LOW/THICK CLOUD COVER WILL
BRING MUCH COOLER TEMPS WITH THE NORTHERN HALF OF THE AREA LIKELY
NOT MAKING IT OUT OF THE UPPER 40S...WITH SOME LOWER 50S NEAR THE
PENNSYLVANIA STATE LINE AND IN CENTRAL NY.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
BY MONDAY EVENING...A DEVELOPING AREA OF LOW PRESSURE ASSOCIATED
WITH A CUT OFF 500 MB LOW WILL BE NEAR KENTUCKY. MEANWHILE...A
STALLED FRONTAL BOUNDARY WILL SIT SOMEWHERE ACROSS WESTERN NEW YORK.
ITS THIS BOUNDARY THAT SHOULD KEY ANY RAIN SHOWERS MONDAY NIGHT. AS THE
LOW LIFTS NORTHWARD...IT WILL FORCE THIS BOUNDARY NORTH AS
WELL...WITH AN INCREASING SOUTHERLY FLOW RESULTING IN WARM AIR
ADVECTION AND LIFT ALONG THIS FRONT. ON MONDAY EVENING EXPECT
SCATTERED SHOWERS ACROSS WESTERN NEW YORK TO ENHANCE AS IT LIFTS
ACROSS LAKE ERIE AND ONTARIO. WHILE MODELS DISAGREE SLIGHTLY ON THE
FRONTAL POSITION...A CONSENSUS BRINGS THE AXIS OF RAIN SHOWERS INTO
SOUTHERN ONTARIO BY DAYBREAK.

ON TUESDAY...THE LOW WILL SLOWLY LIFT INTO OHIO. AS THE SURFACE LOW
LIFTS NORTHWARD...A BROAD AREA OF RAIN WILL LIFT INTO THE REGION
FROM SOUTHWEST TO NORTHEAST. AGAIN...THERE ARE SOME MODEST TIMING
DIFFERENCES...WITH THE GFS ABOUT 6 HOURS FASTER THAN THE
NAM...HOWEVER BOTH MODELS AGREE ON THE GENERAL TREND HERE...SO CAN
JUST SPLIT THE DIFFERENCE. STEADY RAIN SHOULD MOVE IN TUESDAY
AFTERNOON AND EVENING...THEN GRADUALLY EXIT TO THE NORTH LATE
TUESDAY NIGHT.

AS THE LOW LIFTS INTO INTO QUEBEC WEDNESDAY...WINDS WILL SHIFT TO
THE SW AND TEMPERATURES WILL COOL DRAMATICALLY AT BOTH THE SURFACE
AND ALOFT. THIS WILL CAUSE LINGERING RAIN SHOWERS TO MIX WITH SNOW
ON WEDNESDAY. 850 MB TEMPS WILL BE MODESTLY COOL...AT ABOUT -3C. IT
APPEARS FOR MOST...IT WILL BE TOO WARM FOR SNOW SHOWERS TO
ACCUMULATE ON WEDNESDAY. HOWEVER...THE HIGHER TERRAIN OF THE
SOUTHERN TIER BEARS WATCHING. AS THE UPPER LOW PASSES...TEMPERATURES WILL
BE JUST COOL ENOUGH ALOFT FOR SOME MODEST LAKE ENHANCEMENT...AND
SOME UPSLOPING. THIS SAID...IT DOES NOT LOOK LIKE MUCH...PERHAPS A
WET INCH OR TWO ACROSS HIGHER TERRAIN.

WHILE THIS SYSTEM WILL LIKELY CAUSE AN AREA OF HEAVY RAINFALL IN
EXCESS OF TWO INCHES...THIS AREA WILL LIKELY BE TO OUR SOUTH AND
WEST. IT WOULD TAKE A SIGNIFICANT EASTWARD SHIFT IN THE TRACK OF THE
LOW TO CAUSE THIS AXIS TO SHIFT INTO WESTERN NEW YORK...WITH MMEFS
ENSEMBLES SHOWING ONLY A SLIGHT CHANCE OF THIS HAPPENING. IF THERE
WERE TO BE ISSUES...IT WOULD BE IN THE BUFFALO CREEKS. AT THIS
TIME...ABOUT AN INCH OF RAIN IS EXPECTED IN THE NIAGARA
FRONTIER...WITH BETWEEN A HALF INCH AND AN INCH ELSEWHERE. THIS
WOULD NOT BE ENOUGH TO CAUSE FLOODING.

GUSTY NE WINDS WILL DEVELOP ON LAKE ONTARIO AND THE NIAGARA FRONTIER
TUESDAY EVENING. WINDS WILL SHIFT TO THE SOUTHWEST LATE THAT NIGHT
AND WEDNESDAY...WITH BEST WINDS FOCUSING ON LAKE ERIE AND INTO THE
NIAGARA FRONTIER. IN EACH CASE...THE STRONGEST GUSTS LOOK TO BE IN
THE 40 MPH RANGE.

TEMPERATURES WILL CONTINUE TO BE UNSEASONABLY WARM THROUGH TUESDAY
NIGHT. WITH LITTLE DROP IN OVERNIGHT LOWS...ESPECIALLY IN THE
SOUTHERN TIER AND EAST OF LAKE ONTARIO REGIONS.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LINGERING SNOW SHOWERS EAST OF LAKE ONTARIO SHOULD TAPER OFF LATE
WEDNESDAY NIGHT. AFTER THIS...HIGH PRESSURE WILL BUILD INTO THE
REGION THROUGH THURSDAY...BRINGING FAIR WEATHER AND SEASONABLE
TEMPERATURES.

A CLIPPER LOW WILL APPROACH THURSDAY NIGHT...CROSSING THE REGION
FRIDAY. 12Z MODELS HAVE SLOWED A BIT WITH THIS SYSTEM...SO WILL
TREND BACK TIMING ACCORDINGLY. THIS WILL BRING A CHANCE OF SNOW
SHOWERS TO THE REGION FRIDAY...AND ALSO AT THE FIRST MEASURABLE
SNOW OF THE SEASON FOR BUFFALO. 850 MB TEMPS WITH THIS AREA ABOUT
-11C...SO IT SHOULD BE COLD ENOUGH TO PRODUCE LAKE ENHANCED SNOWS
WHERE WINDS ARE FAVORABLE. ITS UNLIKELY THE FAST MOVING WOULD BE
ABLE TO DROP TOO MUCH SNOW GIVEN HOW FAST ITS MOVING.

THE CLIPPER SHOULD EXIT EAST FRIDAY NIGHT...ALLOWING HIGH PRESSURE
TO ONCE AGAIN RIDGE ACROSS THE REGION. SATURDAY SHOULD BE ANOTHER
FAIR AND SEASONABLY COOL DAY.

FOR SUNDAY...THE 12Z GFS/EUROPEAN DIFFER QUITE A BIT. THE GFS DIGS A
TROF INTO THE NORTHEAST...WHICH WOULD BE FAVORABLE FOR SNOW
SHOWERS...WHILE THE EUROPEAN CONTOURS TO KEEP AN UPPER LEVEL RIDGE
ACROSS THE REGION. FOR NOW...LEAN SLIGHTLY TOWARD THE EUROPEAN...AND
KEEP ONLY SLIGHT CHANCE POPS IN FOR SUNDAY.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
THE FIRST BATCH OF SHOWERS IS SPREADING INTO WESTERN NY THIS
AFTERNOON. CIGS/VSBY WILL REMAIN VFR IN MOST LOCATIONS WITH
THIS...ALTHOUGH SOME MVFR WILL BE FOUND ACROSS THE HIGHER ELEVATIONS
OF THE SOUTHERN TIER INCLUDING KJHW...AND ALSO AT KIAG WITH LESS
DOWNSLOPE FLOW AND MORE FLOW OFF LAKE ERIE THAN NEARBY KBUF. MAY SEE
A BREAK IN THE SHOWERS FOR SEVERAL HOURS DURING THE LATE AFTERNOON
AND EARLY EVENING BEFORE A STEADIER RAIN DEVELOPS MID TO LATE
EVENING. ONCE THIS RAIN ARRIVES EXPECT CIGS TO STEADILY DETERIORATE
WITH MVFR GIVING WAY TO IFR OVERNIGHT AS WINDS SLOWLY VEER WITH THE
APPROACH AND PASSAGE OF A COLD FRONT...AND THE LOW LEVELS FULLY
SATURATE. SHOULD SEE WIDESPREAD IFR LASTING FROM LATER TONIGHT
THROUGH MONDAY MORNING. CIGS WILL MAINLY BE MVFR...ALTHOUGH SOME IFR
CIGS WILL ALSO DEVELOP ACROSS THE WESTERN SOUTHERN TIER AND IN ANY
AREAS OF MODERATE RAIN.

ON MONDAY EXPECT A SLOW IMPROVEMENT BACK TO MVFR BY MIDDAY WITH IFR
CIGS LINGERING ACROSS THE SOUTHERN TIER. SCATTERED LIGHT SHOWERS AND
DRIZZLE WILL CONTINUE THROUGH MIDDAY WITH A STALLED OUT FRONTAL
BOUNDARY NEARBY.

LOW LEVEL WIND SHEAR WILL CONTINUE THROUGH THIS EVENING WITH A 40-50
KNOT LOW LEVEL JET OVERHEAD. THIS QUICKLY BREAKS DOWN LATER THIS
EVENING AND WILL BRING AN END TO THE WIND SHEAR.

OUTLOOK...
TUESDAY...AREAS OF MVFR/IFR WITH SHOWERS LIKELY AT TIMES.
WEDNESDAY...MVFR WITH RAIN/SNOW SHOWERS.
THURSDAY...VFR.
FRIDAY...MVFR WITH A CHANCE OF SNOW SHOWERS.

&&

.MARINE...
MODERATE SOUTHERLY WINDS WILL CONTINUE INTO EARLY THIS EVENING
BEFORE DIMINISHING OVERNIGHT AS THE PRESSURE GRADIENT RELAXES. SMALL
CRAFT ADVISORIES WILL BE MAINTAINED THROUGH THIS EVENING ON LAKE
ERIE. LATER TONIGHT A COLD FRONT WILL MOVE SLOWLY SOUTHEAST ACROSS
THE LOWER LAKES REGION WITH WINDS VEERING WEST AND EVENTUALLY
NORTHWEST BY MONDAY MORNING. A BRIEF PERIOD OF 15 KNOT WEST WINDS
WILL OCCUR ON LAKE ONTARIO FROM LATE TONIGHT INTO MONDAY MORNING BUT
THIS WILL BE SHORT LIVED AND WINDS AND WAVES ARE EXPECTED TO REMAIN
JUST BELOW SMALL CRAFT ADVISORY CRITERIA.

LATER MONDAY INTO TUESDAY WINDS WILL DIMINISH AND EVENTUALLY BECOME
EAST TO NORTHEAST AND INCREASE AS LOW PRESSURE ORGANIZES OVER THE
OHIO VALLEY. NORTHEAST WINDS WILL INCREASE TUESDAY NIGHT ESPECIALLY
ON LAKE ONTARIO WITH SOLID SMALL CRAFT ADVISORY CONDITIONS AND AN
OUTSIDE CHANCE OF GALES. WINDS FLIP AROUND TO THE SOUTHWEST ON
WEDNESDAY AS LOW PRESSURE PULLS INTO THE SAINT LAWRENCE VALLEY WITH
ANOTHER PERIOD OF HIGH END SMALL CRAFT ADVISORY CONDITIONS ON BOTH
LAKES.

&&

.CLIMATE...
THE VERY WARM NOVEMBER CONTINUES WITH MANY AREAS ON THE LAKE
PLAINS CRACKING INTO THE LOWER 60S TODAY ON MILD SOUTHERLY WINDS.
HERE ARE SOME STATS THROUGH NOVEMBER 26TH...

AT BUFFALO...THE AVERAGE TEMPERATURE FOR THE MONTH IS 46.3 DEGREES
WHICH IS 4.7 DEGREES ABOVE AVERAGE. THIS RANKS AS THE 6TH WARMEST
ON RECORD. THERE ARE A FEW MORE WARM DAYS ON THE WAY...AND THIS
MAY ALLOW US TO COME UP A SLOT OR TWO BUT THE WARMEST NOVEMBER IS
OUT OF REACH. THERE HAS YET TO BE MEASURABLE SNOW AT THE BUFFALO
AIRPORT WITH A TRACE ON SEVERAL DAYS THIS MONTH. THE LATEST DATE
OF FIRST MEASURABLE SNOW IS DECEMBER 3RD...WITH 4 PREVIOUS YEARS
SEEING NO MEASURABLE SNOW IN THE MONTH OF NOVEMBER. ONE OF THESE
YEARS WAS JUST TWO YEARS AGO IN 2009 WHEN THE FIRST MEASURABLE
SNOW WAS ON DECEMBER 1ST. THERE IS A CHANCE OF SOME WET SNOW ON
WEDNESDAY BUT THIS MAY NOT MEASURE AS SURFACE TEMPERATURES REMAIN
ABOVE FREEZING.

AT ROCHESTER...THE AVERAGE TEMPERATURE FOR THE MONTH IS 45.5
DEGREES WHICH IS 4.2 DEGREES ABOVE AVERAGE. THIS RANKS AS THE 8TH
WARMEST ON RECORD. THERE ARE A FEW MORE WARM DAYS ON THE
WAY...AND THIS MAY ALLOW US TO COME UP A SLOT OR TWO BUT THE
WARMEST NOVEMBER IS OUT OF REACH. UNLIKE BUFFALO...THE ROCHESTER
AIRPORT RECEIVED ITS FIRST MEASURABLE SNOW ON NOVEMBER 17TH.

IT SHOULD BE NOTED THAT PAST RESEARCH SHOWS NO CORRELATION BETWEEN
A WARM FALL AND THE UPCOMING WINTER.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EST THIS EVENING FOR LEZ040-
         041.

&&

$$

SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK
SHORT TERM...APFFEL
LONG TERM...APFFEL
AVIATION...HITCHCOCK
MARINE...HITCHCOCK/TJP
CLIMATE...HITCHCOCK








AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 407 PM EST SUN NOV 27 2011

.SYNOPSIS...
WEAKENING FRONT AND INCREASING MOISTURE TONIGHT INTO MONDAY...WILL
RESULT IN THICKENING CLOUDS WITH SOME LIGHT SHOWERS OR PATCHY
DRIZZLE. HOWEVER...OUR MAIN BATCH OF RAIN WILL COME FROM A LOW
PRESSURE SYSTEM MOVING THROUGH THE REGION TUESDAY AFTERNOON
THROUGH TUESDAY NIGHT. SOME SHOWERS MAY LINGER INTO WEDNESDAY.
BEHIND THE SYSTEM...TEMPERATURES WILL COOL DOWN TO NEAR NORMAL
LEVELS DURING THE SECOND HALF OF THE WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
4 PM UPDATE...TEMPERATURES TOPPED OUT ROUGHLY 13 TO 17 DEGREES
ABOVE NORMAL...BEING HELD BACK FROM GOING FURTHER ONLY BECAUSE OF
THICKENING HIGH CLOUDS. FRONT IS APPROACHING FROM THE WEST BUT
STRUGGLING...WITH MAINLY ONLY VIRGA SO FAR EXCEPT FOR EXTREME
WESTERN PA AND NY. ONE WEAK WAVE TRAVELING THROUGH THE BRISK
SOUTHWEST FLOW WILL MANAGE TO SKIM STEUBEN COUNTY AND SOME OF THE
WESTERN FINGER LAKES WITH LIGHT SHOWERS DURING THE NEXT FEW
HOURS...THE REST OF THE AREA WILL CONTINUE TO SEE THICKENING HIGH
TO MID LEVEL CLOUDS.

A BIT OF A SQUEEZE PLAY TONIGHT INTO MONDAY MORNING...AS FRONT
STALLS OUT IN OUR NORTHWESTERN ZONES WITH LIGHT SHOWERS COMING OUT
OF TOP-DOWN MOISTENING FROM UPPER LEVELS...YET ALSO SHALLOW MARINE
MOISTURE ATTEMPTS TO RIDE IN ON SOUTHERLY LOW LEVEL FLOW. RUC AND
18Z NAM HAVE BACKED OFF SOMEWHAT ON THIS IDEA HOWEVER...WITH LIGHT
SURFACE WIND VEERING TO INCLUDE SOME WESTERLY COMPONENT...WHICH IS
NOT AS FAVORABLE FOR MARINE MOISTURE TO REACH INTO THE AREA. I
HAVE LIMITED PATCHY DRIZZLE MENTION TO SOME OF THE
POCONOS/CATSKILLS REGION SUSCEPTIBLE TO UPSLOPE FLOW...LATER
TONIGHT INTO EARLY MONDAY MORNING. FARTHER NORTHWEST...NOT AS
MUCH LOW LEVEL MOISTURE...YET ENOUGH MOISTURE IN MID/HIGH LEVELS
FOR LIGHT SHOWERS. CLOUDS HANG AROUND THROUGH MONDAY
AFTERNOON...THOUGH WITH ANY SHOWERS DIMINISHING AS WEAK FRONT
BEGINS TO SLOWLY SHIFT NORTHWARD.

WITH AMOUNT OF CLOUD COVER...ESPECIALLY LATE TONIGHT THROUGH
MONDAY...WILL BE STAYING ON WARM SIDE OF GUIDANCE FOR LOWS
TONIGHT...AND COOLER THAN THE MODELS FOR HIGHS MONDAY.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
GOOD MODEL AGREEMENT ON BIG PICTURE FOR UPPER LOW TO PROGRESSIVELY
MOVE THROUGH THE AREA...WITH MODEL CONSENSUS GIVING US OUR MAIN
BATCH OF RAIN LATE TUESDAY INTO TUESDAY NIGHT. WHILE THERE WILL BE
AN ATLANTIC SUBTROPICAL FEED OF MOISTURE...SPEED OF SYSTEM WILL
MINIMIZE ANY THREAT FOR WATER PROBLEMS. AT THIS TIME WE ARE
EXPECTING AREAL AVERAGE OF LESS THAN AN INCH OF RAINFALL.
HOWEVER...SOME MARGINAL INSTABILITY EVIDENT AS NEGATIVELY TILTED
FRONT COMES THROUGH TUESDAY EVENING...TO THE POINT THAT LATER
SHIFTS MAY NEED TO CONSIDER ADDING MENTION OF THUNDER. WITH
DELAYED TIMING OF FRONT...TEMPERATURES LOOK TO GET QUITE WARM ON
TUESDAY.

COLD CORE OF UPPER LOW PASSES DIRECTLY OVERHEAD WEDNESDAY...AND
EXPECTING SCATTERED SHOWERS IN THE WRAP AROUND MOISTURE OF THE
COMMA HEAD. DESPITE STRONG COLD AIR ADVECTION...925-850MB
TEMPERATURES DO NOT SUPPORT SHOWERS CHANGING OVER TO SNOW DURING
THE DAY WEDNESDAY.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
PERIOD BEGINS WITH VIGOROUS STORM SYSTEM EXITING TO THE EAST, AND
HIGH PRESSURE BUILDING NORTHWARD FROM THE LOWER OHIO VALLEY.

A WEAK LOW PRESSURE CENTER AND ASSOCIATED FRONT WILL MOVE OVER
LAKE ONTARIO EARLY FRIDAY, BRINGING WITH IT A CHANCE FOR A RAIN OR
SNOW SHOWER.

A TROF WILL DIG INTO ONTARIO PROVINCE SATURDAY INTO SUNDAY, WITH
SOME JET ACTIVITY ALONG THE US/CANADIAN BORDER. THIS WILL BRING
A BETTER CHANCE FOR SNOW SHOWERS, ESPECIALLY OVER NY STATE, THIS
WEEKEND.

TEMPERATURES WILL FLUCTUATE BETWEEN SYSTEMS, BUT OVERALL WILL BE
TRENDING BACK TOWARD SEASONABLY COOL READINGS.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
A STALLED FRONTAL SYSTEM STRETCHES FROM LOWER ONTARIO, DOWN LAKE
ERIE. SHOWERS ARE MOVING NORTHEASTWARD ALONG THE FRONT, AND WILL
AFFECT OUR TERMINALS LATER TONIGHT WHEN THE FRONT PUSHES EASTWARD.

THE EASTWARD PUSH OF THE FRONT WILL NOT LAST FOR LONG, AS IT IS
FORECAST TO RETROGRADE WESTWARD OVERNIGHT. HOWEVER SOME DRIZZLE
AND SCATTERED SHOWER ACTIVITY WILL AFFECT THE BGM, SYR, ITH, ELM,
AND RME TERMINALS WELL AFTER DARK. CEILINGS WILL SLOWLY DEGRADE TO
MVFR TERRITORY LATE TONIGHT, BEFORE RISING TO A MOSTLY CLOUDY VFR
DECK TOWARD NOON MONDAY.

AT AVP, THE TERMINAL WILL BE AFFECTED BY A MARINE LAYER OF
MOISTURE WHICH IS FORECAST TO MOVE NORTHWARD THROUGH THE WYOMING
VALLEY. MVFR CEILINGS AND VISIBILITIES WILL ARRIVE BETWEEN 4Z AND
6Z, WITH IFR CONDITIONS SOON TO FOLLOW. A COMBINATION OF FOG AND
DRIZZLE WILL KEEP IFR RESTRICTIONS AT AVP THROUGH MID MORNING.

OUTLOOK...

MON NGT...IFR/MVFR. PERIODS OF RAIN AND FOG.

TUE THRU THU...PATCHY MVFR IN SCT -SHRA. SCT -SHSN AND MVFR/BRIEF
IFR POSSIBLE BEGINNING WED.

&&

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

&&

$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...MDP
LONG TERM...DJP
AVIATION...DJP







AREA FORECAST DISCUSSION

NWS BUFFALO NY

 332 PM EST SUN NOV 27 2011

.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL MOVE INTO THE REGION TONIGHT WITH A
PERIOD OF RAIN. THE RAIN WILL LINGER INTO MONDAY MORNING BEFORE
TAPERING TO WIDELY SCATTERED LIGHT SHOWERS BY AFTERNOON AS THE FRONT
WEAKENS IN PLACE. AN AREA OF LOW PRESSURE WILL THEN LIFT ACROSS THE
LOWER LAKES TUESDAY AND TUESDAY NIGHT WITH MORE RAIN...WHICH MAY END
AS A LITTLE WET SNOW ON WEDNESDAY AS COOLER AIR FILTERS INTO THE
REGION. DRY WEATHER WILL RETURN ON THURSDAY BEFORE COLDER AIR
ARRIVES FRIDAY INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
REGIONAL RADAR IMAGERY THIS AFTERNOON SHOWS AN INITIAL BATCH OF
SHOWERS LIFTING ACROSS WESTERN NEW YORK WITH A FEW SPRINKLES ALSO
CROSSING THE EASTERN LAKE ONTARIO REGION. THIS FIRST BATCH OF RAIN
WILL BE VERY LIGHT...AND THE HIGH RESOLUTION HRRR MODEL AND RADAR
TRENDS CONTINUE TO SUGGEST THERE WILL BE A RELATIVE LULL IN SHOWER
ACTIVITY THIS EVENING BETWEEN THIS INITIAL BATCH AND A MORE SOLID
AREA OF RAIN FORECAST TO DEVELOP BY MID TO LATE EVENING ACROSS
WESTERN NEW YORK. TEMPERATURES HAVE SOARED THIS AFTERNOON IN
RESPONSE TO DEEP SOUTHERLY FLOW...WITH UPPER 50S INLAND AND LOWER
60S ON THE LAKE PLAINS DUE TO ADDED COMPRESSIONAL WARMING FROM
DOWNSLOPE FLOW. TEMPS WILL ONLY SLOWLY PULL BACK THIS EVENING AS WE
REMAIN ON THE WARM SIDE OF THE FRONTAL BOUNDARY.

FOR TONIGHT...A COMPLEX TROUGH OVER THE MID SECTION OF THE NATION
WILL SPLIT OVERNIGHT...WITH NORTHERN STREAM ENERGY ACCELERATING EAST
ACROSS QUEBEC...WHILE THE SOUTHERN STREAM ENERGY IS LEFT BEHIND TO
EVOLVE INTO A CLOSED LOW OVER THE LOWER MISSISSIPPI VALLEY. AN
ASSOCIATED COLD FRONT WILL ADVANCE SLOWLY EASTWARD INTO THE REGION
OVERNIGHT...THEN STALL AND WASH OUT ON MONDAY AS THE LOW LEVEL FLOW
QUICKLY EVOLVES INTO A COL BETWEEN THE TWO MID LEVEL CLOSED LOWS.
PWAT OF 1-1.25 INCHES IS AVAILABLE ALONG AND AHEAD OF THIS FRONT...
WHICH IS 2-3 STANDARD DEVIATIONS ABOVE AVERAGE FOR LATE NOVEMBER.
MAIN FORCING MECHANISMS WILL BE FRONTOGENESIS AND CONVERGENCE IN THE
800-700MB LAYER ALONG THE ADVANCING FRONT...AND UPPER LEVEL
DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 140 KNOT UPPER LEVEL
JET.

WITH THE DEEP LAYER FRONTAL ASCENT AND AMPLE SUPPLY OF MOISTURE
WIDESPREAD RAIN ALONG THE FRONTAL BOUNDARY IS A CERTAINTY...THE MAIN
FORECAST CHALLENGE IS THE PLACEMENT AND TIMING WITH A SHARP EASTERN
CUTOFF TO THE STEADIER RAIN. EXPECT THE STEADIER RAIN TO MAKE IT
INTO WESTERN NY DURING THE MID TO LATE EVENING AND THE NORTH COUNTRY
AS WELL BY LATE EVENING...AFTER THAT IT WILL ONLY MAKE VERY SLOW
PROGRESS EASTWARD TOWARDS THE GENESEE VALLEY AND FINGER LAKES. MANY
AREAS IN CENTRAL NY ALONG THE BORDER WITH THE BGM CWA MAY REMAIN DRY
UNTIL LATE TONIGHT. AS FAR AS RAINFALL AMOUNTS GO...EXPECT BASIN
AVERAGE OF A QUARTER TO A THIRD OF AN INCH ACROSS WESTERN NY AND THE
NORTH COUNTRY...WITH MUCH LESS ACROSS THE FINGER LAKES.

MONDAY MORNING EXPECT RAIN TO STILL BE QUITE WIDESPREAD ACROSS MUCH
OF THE REGION AT SUNRISE. THE STEADIER RAIN WILL QUICKLY TAPER OFF
DURING THE MORNING AS FRONTAL CONVERGENCE BREAKS DOWN DUE TO THE
LOSS OF MID LEVEL FLOW WITHIN THE DEVELOPING COL REGION. THERE WILL
BE PLENTY OF LOW CLOUDS AROUND IN THE WEAK NORTHERLY UPSLOPE FLOW
BEHIND THE WASHING OUT FRONTAL BOUNDARY...SO THIS WILL LIKELY ALLOW
LIGHT SHOWERS AND DRIZZLE TO LINGER INTO THE EARLY AFTERNOON. LATER
IN THE DAY EXPECT MUCH OF THE AREA TO BE DRY...ALTHOUGH WITH THE
LINGERING FRONTAL BOUNDARY NEARBY CANNOT RULE OUT A FEW LIGHT
SHOWERS ESPECIALLY FROM THE SOUTHERN TIER INTO THE FINGER LAKES.

WESTERN AND CENTRAL NY WILL BE ON THE COOL SIDE OF THE BOUNDARY BY
MONDAY...AND THAT COMBINED WITH PLENTY OF LOW/THICK CLOUD COVER WILL
BRING MUCH COOLER TEMPS WITH THE NORTHERN HALF OF THE AREA LIKELY
NOT MAKING IT OUT OF THE UPPER 40S...WITH SOME LOWER 50S NEAR THE
PENNSYLVANIA STATE LINE AND IN CENTRAL NY.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
BY MONDAY EVENING...A DEVELOPING AREA OF LOW PRESSURE ASSOCIATED
WITH A CUT OFF 500 MB LOW WILL BE NEAR KENTUCKY. MEANWHILE...A
STALLED FRONTAL BOUNDARY WILL SIT SOMEWHERE ACROSS WESTERN NEW YORK.
ITS THIS BOUNDARY THAT SHOULD KEY ANY RAIN SHOWERS MONDAY NIGHT. AS THE
LOW LIFTS NORTHWARD...IT WILL FORCE THIS BOUNDARY NORTH AS
WELL...WITH AN INCREASING SOUTHERLY FLOW RESULTING IN WARM AIR
ADVECTION AND LIFT ALONG THIS FRONT. ON MONDAY EVENING EXPECT
SCATTERED SHOWERS ACROSS WESTERN NEW YORK TO ENHANCE AS IT LIFTS
ACROSS LAKE ERIE AND ONTARIO. WHILE MODELS DISAGREE SLIGHTLY ON THE
FRONTAL POSITION...A CONSENSUS BRINGS THE AXIS OF RAIN SHOWERS INTO
SOUTHERN ONTARIO BY DAYBREAK.

ON TUESDAY...THE LOW WILL SLOWLY LIFT INTO OHIO. AS THE SURFACE LOW
LIFTS NORTHWARD...A BROAD AREA OF RAIN WILL LIFT INTO THE REGION
FROM SOUTHWEST TO NORTHEAST. AGAIN...THERE ARE SOME MODEST TIMING
DIFFERENCES...WITH THE GFS ABOUT 6 HOURS FASTER THAN THE
NAM...HOWEVER BOTH MODELS AGREE ON THE GENERAL TREND HERE...SO CAN
JUST SPLIT THE DIFFERENCE. STEADY RAIN SHOULD MOVE IN TUESDAY
AFTERNOON AND EVENING...THEN GRADUALLY EXIT TO THE NORTH LATE
TUESDAY NIGHT.

AS THE LOW LIFTS INTO INTO QUEBEC WEDNESDAY...WINDS WILL SHIFT TO
THE SW AND TEMPERATURES WILL COOL DRAMATICALLY AT BOTH THE SURFACE
AND ALOFT. THIS WILL CAUSE LINGERING RAIN SHOWERS TO MIX WITH SNOW
ON WEDNESDAY. 850 MB TEMPS WILL BE MODESTLY COOL...AT ABOUT -3C. IT
APPEARS FOR MOST...IT WILL BE TOO WARM FOR SNOW SHOWERS TO
ACCUMULATE ON WEDNESDAY. HOWEVER...THE HIGHER TERRAIN OF THE
SOUTHERN TIER BEARS WATCHING. AS THE UPPER LOW PASSES...TEMPERATURES WILL
BE JUST COOL ENOUGH ALOFT FOR SOME MODEST LAKE ENHANCEMENT...AND
SOME UPSLOPING. THIS SAID...IT DOES NOT LOOK LIKE MUCH...PERHAPS A
WET INCH OR TWO ACROSS HIGHER TERRAIN.

WHILE THIS SYSTEM WILL LIKELY CAUSE AN AREA OF HEAVY RAINFALL IN
EXCESS OF TWO INCHES...THIS AREA WILL LIKELY BE TO OUR SOUTH AND
WEST. IT WOULD TAKE A SIGNIFICANT EASTWARD SHIFT IN THE TRACK OF THE
LOW TO CAUSE THIS AXIS TO SHIFT INTO WESTERN NEW YORK...WITH MMEFS
ENSEMBLES SHOWING ONLY A SLIGHT CHANCE OF THIS HAPPENING. IF THERE
WERE TO BE ISSUES...IT WOULD BE IN THE BUFFALO CREEKS. AT THIS
TIME...ABOUT AN INCH OF RAIN IS EXPECTED IN THE NIAGARA
FRONTIER...WITH BETWEEN A HALF INCH AND AN INCH ELSEWHERE. THIS
WOULD NOT BE ENOUGH TO CAUSE FLOODING.

GUSTY NE WINDS WILL DEVELOP ON LAKE ONTARIO AND THE NIAGARA FRONTIER
TUESDAY EVENING. WINDS WILL SHIFT TO THE SOUTHWEST LATE THAT NIGHT
AND WEDNESDAY...WITH BEST WINDS FOCUSING ON LAKE ERIE AND INTO THE
NIAGARA FRONTIER. IN EACH CASE...THE STRONGEST GUSTS LOOK TO BE IN
THE 40 MPH RANGE.

TEMPERATURES WILL CONTINUE TO BE UNSEASONABLY WARM THROUGH TUESDAY
NIGHT. WITH LITTLE DROP IN OVERNIGHT LOWS...ESPECIALLY IN THE
SOUTHERN TIER AND EAST OF LAKE ONTARIO REGIONS.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LINGERING SNOW SHOWERS EAST OF LAKE ONTARIO SHOULD TAPER OFF LATE
WEDNESDAY NIGHT. AFTER THIS...HIGH PRESSURE WILL BUILD INTO THE
REGION THROUGH THURSDAY...BRINGING FAIR WEATHER AND SEASONABLE
TEMPERATURES.

A CLIPPER LOW WILL APPROACH THURSDAY NIGHT...CROSSING THE REGION
FRIDAY. 12Z MODELS HAVE SLOWED A BIT WITH THIS SYSTEM...SO WILL
TREND BACK TIMING ACCORDINGLY. THIS WILL BRING A CHANCE OF SNOW
SHOWERS TO THE REGION FRIDAY...AND ALSO AT THE FIRST MEASURABLE
SNOW OF THE SEASON FOR BUFFALO. 850 MB TEMPS WITH THIS AREA ABOUT
-11C...SO IT SHOULD BE COLD ENOUGH TO PRODUCE LAKE ENHANCED SNOWS
WHERE WINDS ARE FAVORABLE. ITS UNLIKELY THE FAST MOVING WOULD BE
ABLE TO DROP TOO MUCH SNOW GIVEN HOW FAST ITS MOVING.

THE CLIPPER SHOULD EXIT EAST FRIDAY NIGHT...ALLOWING HIGH PRESSURE
TO ONCE AGAIN RIDGE ACROSS THE REGION. SATURDAY SHOULD BE ANOTHER
FAIR AND SEASONABLY COOL DAY.

FOR SUNDAY...THE 12Z GFS/EUROPEAN DIFFER QUITE A BIT. THE GFS DIGS A
TROF INTO THE NORTHEAST...WHICH WOULD BE FAVORABLE FOR SNOW
SHOWERS...WHILE THE EUROPEAN CONTOURS TO KEEP AN UPPER LEVEL RIDGE
ACROSS THE REGION. FOR NOW...LEAN SLIGHTLY TOWARD THE EUROPEAN...AND
KEEP ONLY SLIGHT CHANCE POPS IN FOR SUNDAY.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
THE FIRST BATCH OF SHOWERS IS SPREADING INTO WESTERN NY THIS
AFTERNOON. CIGS/VSBY WILL REMAIN VFR IN MOST LOCATIONS WITH
THIS...ALTHOUGH SOME MVFR WILL BE FOUND ACROSS THE HIGHER ELEVATIONS
OF THE SOUTHERN TIER INCLUDING KJHW...AND ALSO AT KIAG WITH LESS
DOWNSLOPE FLOW AND MORE FLOW OFF LAKE ERIE THAN NEARBY KBUF. MAY SEE
A BREAK IN THE SHOWERS FOR SEVERAL HOURS DURING THE LATE AFTERNOON
AND EARLY EVENING BEFORE A STEADIER RAIN DEVELOPS MID TO LATE
EVENING. ONCE THIS RAIN ARRIVES EXPECT CIGS TO STEADILY DETERIORATE
WITH MVFR GIVING WAY TO IFR OVERNIGHT AS WINDS SLOWLY VEER WITH THE
APPROACH AND PASSAGE OF A COLD FRONT...AND THE LOW LEVELS FULLY
SATURATE. SHOULD SEE WIDESPREAD IFR LASTING FROM LATER TONIGHT
THROUGH MONDAY MORNING. CIGS WILL MAINLY BE MVFR...ALTHOUGH SOME IFR
CIGS WILL ALSO DEVELOP ACROSS THE WESTERN SOUTHERN TIER AND IN ANY
AREAS OF MODERATE RAIN.

ON MONDAY EXPECT A SLOW IMPROVEMENT BACK TO MVFR BY MIDDAY WITH IFR
CIGS LINGERING ACROSS THE SOUTHERN TIER. SCATTERED LIGHT SHOWERS AND
DRIZZLE WILL CONTINUE THROUGH MIDDAY WITH A STALLED OUT FRONTAL
BOUNDARY NEARBY.

LOW LEVEL WIND SHEAR WILL CONTINUE THROUGH THIS EVENING WITH A 40-50
KNOT LOW LEVEL JET OVERHEAD. THIS QUICKLY BREAKS DOWN LATER THIS
EVENING AND WILL BRING AN END TO THE WIND SHEAR.

OUTLOOK...
TUESDAY...AREAS OF MVFR/IFR WITH SHOWERS LIKELY AT TIMES.
WEDNESDAY...MVFR WITH RAIN/SNOW SHOWERS.
THURSDAY...VFR.
FRIDAY...MVFR WITH A CHANCE OF SNOW SHOWERS.

&&

.MARINE...
MODERATE SOUTHERLY WINDS WILL CONTINUE INTO EARLY THIS EVENING
BEFORE DIMINISHING OVERNIGHT AS THE PRESSURE GRADIENT RELAXES. SMALL
CRAFT ADVISORIES WILL BE MAINTAINED THROUGH EARLY EVENING ON LAKE
ERIE. LATER TONIGHT A COLD FRONT WILL MOVE SLOWLY SOUTHEAST ACROSS
THE LOWER LAKES REGION WITH WINDS VEERING WEST AND EVENTUALLY
NORTHWEST BY MONDAY MORNING. A BRIEF PERIOD OF 15 KNOT WEST WINDS
WILL OCCUR ON LAKE ONTARIO FROM LATE TONIGHT INTO MONDAY MORNING BUT
THIS WILL BE SHORT LIVED AND WINDS AND WAVES ARE EXPECTED TO REMAIN
JUST BELOW SMALL CRAFT ADVISORY CRITERIA.

LATER MONDAY INTO TUESDAY WINDS WILL DIMINISH AND EVENTUALLY BECOME
EAST TO NORTHEAST AND INCREASE AS LOW PRESSURE ORGANIZES OVER THE
OHIO VALLEY. NORTHEAST WINDS WILL INCREASE TUESDAY NIGHT ESPECIALLY
ON LAKE ONTARIO WITH SOLID SMALL CRAFT ADVISORY CONDITIONS AND AN
OUTSIDE CHANCE OF GALES. WINDS FLIP AROUND TO THE SOUTHWEST ON
WEDNESDAY AS LOW PRESSURE PULLS INTO THE SAINT LAWRENCE VALLEY WITH
ANOTHER PERIOD OF HIGH END SMALL CRAFT ADVISORY CONDITIONS ON BOTH
LAKES.

&&

.CLIMATE...
THE VERY WARM NOVEMBER CONTINUES WITH MANY AREAS ON THE LAKE
PLAINS CRACKING INTO THE LOWER 60S TODAY ON MILD SOUTHERLY WINDS.
HERE ARE SOME STATS THROUGH NOVEMBER 26TH...

AT BUFFALO...THE AVERAGE TEMPERATURE FOR THE MONTH IS 46.3 DEGREES
WHICH IS 4.7 DEGREES ABOVE AVERAGE. THIS RANKS AS THE 6TH WARMEST
ON RECORD. THERE ARE A FEW MORE WARM DAYS ON THE WAY...AND THIS
MAY ALLOW US TO COME UP A SLOT OR TWO BUT THE WARMEST NOVEMBER IS
OUT OF REACH. THERE HAS YET TO BE MEASURABLE SNOW AT THE BUFFALO
AIRPORT WITH A TRACE ON SEVERAL DAYS THIS MONTH. THE LATEST DATE
OF FIRST MEASURABLE SNOW IS DECEMBER 3RD...WITH 4 PREVIOUS YEARS
SEEING NO MEASURABLE SNOW IN THE MONTH OF NOVEMBER. ONE OF THESE
YEARS WAS JUST TWO YEARS AGO IN 2009 WHEN THE FIRST MEASURABLE
SNOW WAS ON DECEMBER 1ST. THERE IS A CHANCE OF SOME WET SNOW ON
WEDNESDAY BUT THIS MAY NOT MEASURE AS SURFACE TEMPERATURES REMAIN
ABOVE FREEZING.

AT ROCHESTER...THE AVERAGE TEMPERATURE FOR THE MONTH IS 45.5
DEGREES WHICH IS 4.2 DEGREES ABOVE AVERAGE. THIS RANKS AS THE 8TH
WARMEST ON RECORD. THERE ARE A FEW MORE WARM DAYS ON THE
WAY...AND THIS MAY ALLOW US TO COME UP A SLOT OR TWO BUT THE
WARMEST NOVEMBER IS OUT OF REACH. UNLIKE BUFFALO...THE ROCHESTER
AIRPORT RECEIVED ITS FIRST MEASURABLE SNOW ON NOVEMBER 17TH.

IT SHOULD BE NOTED THAT PAST RESEARCH SHOWS NO CORRELATION BETWEEN
A WARM FALL AND THE UPCOMING WINTER.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR LEZ040-
         041.

&&

$$

SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK
SHORT TERM...APFFEL
LONG TERM...APFFEL
AVIATION...HITCHCOCK
MARINE...HITCHCOCK
CLIMATE...HITCHCOCK






AREA FORECAST DISCUSSION

NWS BUFFALO NY

 1255 PM EST SUN NOV 27 2011

.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL APPROACH THE REGION ON TODAY WITH
THICKENING CLOUDS AND INCREASING RAIN CHANCES FROM WEST TO EAST.
SHOWERS WILL LAST INTO TONIGHT BEFORE THE FRONT FALLS APART ON
MONDAY WITH JUST A SMALL CHANCE OF A LINGERING SHOWER. AN AREA OF
LOW PRESSURE WILL THEN LIFT ACROSS THE REGION TUESDAY AFTERNOON AND
TUESDAY NIGHT WITH ANOTHER ROUND OF SHOWERS WHICH MAY END AS SOME
WET SNOW ON WEDNESDAY AS SOMEWHAT COLDER AIR ARRIVES.

&&

.NEAR TERM /THROUGH TONIGHT/...
RADAR IMAGERY EARLY THIS AFTERNOON SHOWS MAINLY LIGHT SHOWERS
ENTERING WESTERN NY. A BREAK IN THE RAIN HAS DEVELOPED IN THE PAST
FEW HOURS ACROSS MUCH OF NORTHEAST OHIO AND CENTRAL LAKE ERIE. THE
EXPERIMENTAL HIGH RESOLUTION 3KM HRRR MODEL SEEMS TO HAVE A GOOD
HANDLE ON THIS...WITH THE INITIAL BATCH OF SHOWERS MOVING THROUGH
THIS AFTERNOON FOLLOWED BY A SEVERAL HOUR BREAK...THEN A STEADIER
RAIN MOVING IN AGAIN BY MID EVENING. WILL CONTINUE TO MONITOR
UPSTREAM RADAR TRENDS...AND IF THIS APPEARS TO BE THE CASE WILL
ATTEMPT TO BUILD THIS TIMING INTO THE NEXT GRID UPDATE.

THIS FRONT IS SLOW MOVING AND WILL CONTINUE TO SLOW DOWN...SO
CENTRAL NY MAY REMAIN DRY FOR MOST IF NOT THE ENTIRE DAY WITH A
RATHER SHARP EASTERN GRADIENT IN PRECIP CHANCES.

850MB TEMPS OF AROUND +9C AND ONGOING DEEP SOUTHERLY FLOW WILL BRING
ANOTHER DAY OF WELL ABOVE AVERAGE TEMPS WITH SOUTHERLY DOWNSLOPE
FLOW BOOSTING THE LAKE PLAINS TO NEAR 60 ONCE AGAIN...WITH LOW 60S
FROM ROCHESTER OVER TOWARD SYRACUSE. FAR WESTERN NY WILL SEE TEMPS
DROP BACK A FEW DEGREES THIS AFTERNOON AS THE STEADIER RAIN MOVE IN.
HIGHER TERRAIN WILL REMAIN IN THE MID TO UPPER 50S WITHOUT THE
BENEFIT OF DOWNSLOPE COMPRESSIONAL WARMING.

EXPECT THE FRONT TO LOSE ALMOST ALL EASTWARD MOTION TONIGHT AND THE
PRECIP WILL WEAKEN SUBSTANTIALLY AS THE UPPER TROUGH LIFTS
NORTHWARD. TEMPS WILL STILL BE WELL ABOVE NORMAL FOR THE NIGHT WITH
LOWS IN THE MID 40S ACROSS THE WEST AND TO NEAR 50 FOR THE EASTERN
LAKE ONTARIO REGION.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
00Z MODELS CONTINUING TO COME INTO BETTER AGREEMENT TO THE OVERALL
SYNOPTIC PATTERN DURING THIS PORTION OF THE FORECAST...LEADING TO
INCREASED FORECASTER CONFIDENCE.

WEAK FRONTAL BOUNDARY WILL BE DROPPING DOWN ACROSS THE SAINT
LAWRENCE VALLEY AND FAR WESTERN NEW YORK AT THE START OF THE PERIOD.
THIS BOUNDARY LOOKS TO EVENTUALLY WASH OUT...AS HIGH PRESSURE
REMAINS ANCHORED OFF THE ATLANTIC COAST AND A CUTOFF LOW DEVELOPS
OVER THE SOUTHEAST STATES...RESULTING IN HEIGHT RISES ACROSS THE
NORTHEAST. WE THINK THAT THERE WILL BE ENOUGH MOISTURE ALONG THE
FRONTAL ZONE FOR THE LIKELIHOOD FOR SHOWERS MONDAY MORNING...THEN
TRENDING TOWARD A DRIER FORECAST AS WE GET INTO THE AFTERNOON AND
EVENING. TEMPERATURES WILL BE PROBLEMATIC FOR MONDAY WITH THE
FRONTAL AND PRECIPITATION POTENTIALLY RESULTING IN A LARGE NORTH
TO SOUTH TEMPERATURES VARIATION WITH HIGHS RANGING FROM THE UPPER
40S IN THE NIAGARA FRONTIER...TO NEAR 60 IN THE SOUTHERN TIER.
SUBTLE SHIFTS IN THE FRONT MAY REQUIRE SIGNIFICANT ADJUSTMENTS TO
TEMPERATURES IN THE FUTURE.

THE SOUTHEASTERN CLOSED LOW WILL LIFT NORTHEASTWARD MONDAY NIGHT
AND TUESDAY...EVENTUALLY REACHING CENTRAL NEW YORK BY TUESDAY NIGHT.
STILL SOME SLIGHT TIMING DIFFERENCES EXIST BETWEEN THE GFS AND ECMWF
ON THE TIMING OF THIS SYSTEM...WITH THE ECMWF BEING ABOUT 6 HOURS
SLOWER. MAJORITY OF THE RAIN SHOULD FALL IN THE TUESDAY THROUGH
TUESDAY NIGHT TIME FRAME AS THE LOW APPROACHES. WILL HAVE TO KEEP
ON EYE ON RAINFALL AMOUNTS WITH THIS SYSTEM AS THERE IS SOME
POTENTIAL FOR MODERATE TO HEAVY RAINFALL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
COOLER AIR WILL BUILD BEHIND THE LOW WEDNESDAY...MARGINALLY COLD
ENOUGH TO SUPPORT SNOW. GIVEN 850 MB TEMPS WILL ONLY BE -2 TO -4C
ON WEDNESDAY...CHANCES FOR MEASURABLE SNOW WILL BE LIMITED.

BY THIS TIME...THERE IS ACTUALLY QUITE GOOD MODEL AGREEMENT...AS THE
12Z GGEM/EUROPEAN/GFS ALL LIFT THE LOW INTO THE CANADIAN MARITIMES.
EXPECT FAIR AND SEASONABLE WEATHER ON THURSDAY.

MODELS ALL BRING A RATHER SHARP BUT PROGRESSIVE UPPER LEVEL TROF
ACROSS THE REGION LATE THURSDAY NIGHT INTO FRIDAY. TEMPERATURES ARE
FAIRLY COLD WITH THIS...SO THIS WILL BRING A CHANCE OF SNOW SHOWERS
BOTH WITH THE UPPER TROF...AND CONSIDERING LAKE ENHANCEMENT. WHILE
THE SPEED OF THE TROF WILL LIMIT THE CHANCES FOR HEAVY
ACCUMULATIONS...THERE IS A CHANCE FOR MEASURABLE SNOW IN WESTERN NEW
YORK WITH THIS SYSTEM.

THE LOW WILL QUICKLY EXIT SATURDAY NIGHT...WITH ANOTHER FAIR BUT
SEASONABLE DAY EXPECTED ON SATURDAY... AS A ZONAL FLOW DEVELOPS.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THE FIRST BATCH OF SHOWERS IS SPREADING INTO WESTERN NY THIS
AFTERNOON. CIGS/VSBY WILL REMAIN VFR IN MOST LOCATIONS WITH
THIS...ALTHOUGH SOME MVFR WILL BE FOUND ACROSS THE HIGHER ELEVATIONS
OF THE SOUTHERN TIER INCLUDING KJHW...AND ALSO AT KIAG WITH LESS
DOWNSLOPE FLOW AND MORE FLOW OFF LAKE ERIE THAN NEARBY KBUF. MAY SEE
A BREAK IN THE SHOWERS FOR SEVERAL HOURS DURING THE LATE AFTERNOON
AND EARLY EVENING BEFORE A STEADIER RAIN DEVELOPS MID TO LATE
EVENING. ONCE THIS RAIN ARRIVES EXPECT CIGS TO STEADILY DETERIORATE
WITH MVFR GIVING WAY TO IFR OVERNIGHT AS WINDS SLOWLY VEER WITH THE
APPROACH AND PASSAGE OF A COLD FRONT...AND THE LOW LEVELS FULLY
SATURATE. SHOULD SEE WIDESPREAD IFR LASTING FROM LATER TONIGHT
THROUGH MONDAY MORNING. CIGS WILL MAINLY BE MVFR...ALTHOUGH SOME IFR
CIGS WILL ALSO DEVELOP ACROSS THE WESTERN SOUTHERN TIER AND IN ANY
AREAS OF MODERATE RAIN.

ON MONDAY EXPECT A SLOW IMPROVEMENT BACK TO MVFR BY MIDDAY WITH IFR
CIGS LINGERING ACROSS THE SOUTHERN TIER. SCATTERED LIGHT SHOWERS AND
DRIZZLE WILL CONTINUE THROUGH MIDDAY WITH A STALLED OUT FRONTAL
BOUNDARY NEARBY.

LOW LEVEL WIND SHEAR WILL CONTINUE THROUGH THIS EVENING WITH A 40-50
KNOT LOW LEVEL JET OVERHEAD. THIS QUICKLY BREAKS DOWN LATER THIS
EVENING AND WILL BRING AN END TO THE WIND SHEAR.

OUTLOOK...
TUESDAY...AREAS OF MVFR/IFR WITH SHOWERS LIKELY AT TIMES.
WEDNESDAY...MVFR WITH RAIN/SNOW SHOWERS.
THURSDAY...VFR.
FRIDAY...MVFR WITH A CHANCE OF SNOW SHOWERS.

&&

.MARINE...
LIGHT SOUTHERLY WINDS WILL INCREASE AND BECOME SOUTH SOUTHWEST
TODAY IN ADVANCE OF A COLD FRONT PUSHING THROUGH THE CENTRAL GREAT
LAKES. WINDS WILL INCREASE ENOUGH TO BRING SMALL CRAFT ADVISORY
CONDITIONS ON LAKE ERIE STARTING EARLY THIS MORNING AND CONTINUING
THROUGH THE AFTERNOON. AT THE EAST END OF LAKE ONTARIO WINDS WILL
NOT INCREASE SUFFICIENTLY TO WARRANT A SMALL CRAFT ADVISORY.

LATER SUNDAY NIGHT AND MONDAY THE PRESSURE GRADIENT WILL RELAX AS
THE COLD FRONT FALLS APART OVERHEAD.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR LEZ040-
         041.

&&

$$

SYNOPSIS...WCH
NEAR TERM...HITCHCOCK/WCH
SHORT TERM...TMA
LONG TERM...APFFEL
AVIATION...HITCHCOCK
MARINE...WCH






AREA FORECAST DISCUSSION

NWS NEWPORT/MOREHEAD CITY NC

 1045 PM EST MON NOV 28 2011

.SYNOPSIS...
A COLD FRONT WILL SWEEP THROUGH THE AREA TUESDAY MORNING FROM THE
WEST. HIGH PRESSURE WILL BUILD INTO NORTH CAROLINA WEDNESDAY
THROUGH THURSDAY. ANOTHER COLD FRONT WILL PASS THROUGH THE REGION
FRIDAY NIGHT. HIGH PRESSURE WILL ONCE AGAIN BUILD INTO THE AREA
NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 1030 PM MON...MOIST SELY FLOW CONTINUES ACROSS THE REGION
THIS EVENING AHEAD OF A STRONG COLD FRONT PRESENTLY SLOWLY MOVING
ACROSS THE NC PIEDMONT AND INTO SERN NC WITH ASSOC UPPER LOW
SLOWLY PUSHING ACROSS NRN MS/AL AND S CNTRL TN. 00Z KMHX SOUNDING
SHOWS FAIRLY MOIST BELOW 800 MB BUT REMAINS DRY ABOVE WITH PW`S
SIMILAR TO THIS MORNING AROUND 0.85". DON`T THINK WE WILL SEE MORE
THAN AN ISOLATED LIGHT SHOWER THROUGH THE REMAINDER OF THE EVENING
WITH MOISTURE REMAINING SHALLOW. LATEST HRRR MODEL RUN INDICATING
STRONGER FORCING/HEAVIER PCPN PUSHING INTO DUPLIN CO AROUND 3 AM
AND TO NEAR A CAPE LOOKOUT TO GREENVILLE LINE BY 6 AM...WHICH IS
CLOSE TO THE LEAD TIME OF ARRIVAL TOOLS.

AS THE FRONT MOVES EAST OVERNIGHT...LLJ WILL INC TO AOA 40 KT WITH
PWATS INC TO AROUND 1.5 INCHES. TREMENDOUS KINEMATICS WILL BE IN
PLACE WITH THE COLD FRONT...THOUGH LACKING INGREDIENT WILL BE
INSTABILITY. STILL...AN ISOLATED EMBEDDED STORM IS STILL POSSIBLE
AS FORCING WILL BE VERY STRONG... AND MAY PRODUCE LOCALLY DAMAGING
WIND GUSTS.

TEMPS THIS EVENING HAVE FALLEN INTO THE M/U60S AND DON`T EXPECT
THEM TO DROP MUCH MORE OVERNIGHT AS STRONG WAA PERSISTS AHEAD OF
THE FRONT...THE EXCEPTION BEING FAR WRN PORTION OF THE CWA WHERE
THE FRONT IS EXPECTED TO REACH BY 6 AM AND COULD SEE TEMPS FALLING
TO AROUND 60 AFTER FROPA.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AS OF 3 PM MON...LINE OF SHOWERS WILL TRANSLATE EAST INTO THE
REST OF THE FA THROUGH THE MORNING ON TUE...REACHING THE OBX
AROUND THE NOON HOUR. AN ISO THUNDERSTORM WILL STILL BE
POSSIBLE...THOUGH STRONG CAA WILL LIMIT THE POTENTIAL FOR ANYTHING
MORE THAN AN ISO MENTION. DAYTIME HIGHS IN THE 60S WILL BE
REALIZED TUE MORNING...WITH TEMPS FALLING FROM WEST TO EAST
THROUGHOUT THE DAY BEHIND THE FROPA. BY AFTERNOON MANY AREAS WILL
HAVE DROPPED WELL INTO THE 50S. RAIN WILL CLEAR OUT FOR MOST AREAS
EXCEPT THE OBX BY EARLY AFTERNOON...WITH ONLY SOME SCT SHOWERS
REMAINING.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
CUTOFF LOW MOVES QUICKLY NORTH UP THE APPALACHIANS TUE NIGHT. WEAK
SFC RIDGE BUILDS ACROSS THE AREA TUE NIGHT IN THE WAKE OF COLD
FRONTAL PASSAGE. ANY LINGERING SHOWERS WILL BE ENDING OVER THE OUTER
BANKS EARLY TUE EVENING AS THE MID LEVEL DRYING MOVES TO THE COAST.
MUCH COOLER AIR WILL WORK INTO THE AREA AROUND THE DEPARTING UPPER
LOW WITH LOW TEMPS TUE NIGHT FALLING INTO THE 30S INLAND WITH
LOW-MID 40S AT THE COAST.

BELOW NORMAL TEMPERATURES WILL HIGHLIGHT THE WED THRU SAT TIMEFRAME
AS SEVERAL REINFORCING SHOTS OF COOLER AIR INVADE THE AREA. MOISTURE
WILL BE TOO SCARCE FOR ORGANIZED PCPN BUT MAY SEE CLOUDY INTERVALS
AS WEAK SHORT WAVES PASS THRU THE AREA.

TEMPERATURES WILL BEGIN TO MODERATE LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK AS RETURN FLOW GRADUALLY SETS UP AHEAD OF DOWNSTREAM
TROF. TIMING OF PCPN CHCS MAY BE TIED TO PROGRESSIVENESS OF LARGE
SCALE TROF BEING CARVED OUT OVER THE UPPER MIDWEST EARLY NEXT WEEK.
WILL KEEP THE DAY 7 FCST DRY FOR NOW UNTIL THE TIMING OF THIS
DOWNSTREAM FEATURE CAN BE BETTER RESOLVED.

&&

.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH TUESDAY/...
AS OF 8 PM MON...VFR CONDITIONS CONTINUE THIS EVENING WITH MOIST
SELY FLOW PERSISTING BELOW 7K FT. LLJ WILL INC TO ABOVE 30 KT BY
06Z...AND NON CONVECTIVE LLWS MAY BE AN ISSUE AS SFC FLOW REMAINS
BELOW 10 KT. LARGE UPR CLOSED LOW AND ASSOCIATED COLD FRONT WILL
APPROACH AND PASS THROUGH E NC AFTER 12Z...WITH A PERIOD OF HEAVY
SHOWERS AND AN ISO THUNDERSTORM LIKELY. CIGS/VSBYS WILL TEMPORARILY
BE RESTRICTED TO IFR AS THE SHOWERS MOVE THROUGH. AT THIS TIME IT
LOOKS LIKE THE WINDOW FOR FLIGHT RESTRICTIONS AT THE TERMINALS WILL
BE AROUND 09Z THROUGH 16Z...WITH CONDITIONS IMPROVING THEREAFTER.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
VFR CONDITIONS EXPECTED FOR A LARGE PART OF THIS FCST PERIOD AS
DRIER AIR FILTERS INTO THE REGION. MAY BE SOME CLOUDY INTERVALS DUE
TO WEAK SHORT WAVE PASSAGES BUT EXPECT CLOUD BASES WILL BE HIGHER
THAN 3K FT FOR THE MOST PART. MAY ALSO SEE BRIEF/PATCHY LATE
NIGHT/EARLY MORNING RADIATION FOG AS DEW POINT DEPRESSIONS LOWER
LATER IN THE WEEK.

&&

.MARINE...
SHORT TERM /THROUGH TUESDAY/...
AS OF 8 PM MON...WINDS AND SEAS GRADUALLY INCREASING THIS EVENING
AHEAD OF A STRONG COLD FRONT PRESENTLY PUSHING ACROSS SC. FORECAST
LOOKS ON TRACK WITH WINDS AROUD 15-20 KT SRN AND CENTRAL WATERS
AND 10-15 KT ELSEWHERE. SEAS ARE ALSO BUILDING ACROSS SRN/CENTRAL
WATERS WHERE BUOY 41036 NOW UP TO 8FT. GRADIENT INC FURTHER AS
THE STRONG COLD FRONT APPROACHES LATE TONIGHT...AND WINDS AND SEAS
WILL CONTINUE TO INC. SEAS WILL INC AND BUILD FROM S TO N...WITH
SCA CONDITIONS BEING MET FOR THE NORTHERN WATERS BY EARLY TUE
MORNING. KEPT SCA OUT OF THE SOUNDS FOR NOW...AS THE COOLER WATERS
SHOULD KEEP WINDS JUST BELOW THE 25 KT THRESHOLD...THOUGH GUSTS
MAY GET CLOSE TO THAT BY EARLY TUE MORNING. WINDS WILL VEER FROM
SE TO SW BEHIND THE COLD FRONT LATE TUE MORNING THROUGH AFTERNOON.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODERATE (15-20KT) SW/W WINDS TUE NIGHT/WED WILL SHIFT MORE NW/N AT
ROUGHLY THE SAME SPEEDS AS WEAK SFC TROF PASSES ON THURSDAY. SEAS
WILL INITIALLY FALL BLO SMALL CRAFT ADVISORY LEVELS (6 FT) FOR A
TIME LATE WED/WED NIGHT BEFORE BUILDING BACK ABV 6 FT AGAIN AS WINDS
BECOME MORE NORTHERLY AND CONTINUE AT MODERATE LEVELS THU-SAT.
THEREFORE SMALL CRAFT ADVISORIES MAY AGAIN BE REQUIRED LATER IN THE
WEEK...MAINLY FOR SEAS.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR AMZ152-154.
     SMALL CRAFT ADVISORY UNTIL 4 PM EST WEDNESDAY FOR AMZ156-158.
     SMALL CRAFT ADVISORY FROM 5 AM TUESDAY TO 5 AM EST WEDNESDAY
     FOR AMZ150.

&&

$$
SYNOPSIS...TL
NEAR TERM...SK/TL
SHORT TERM...TL
LONG TERM...BTC
AVIATION...BTC/SK/TL
MARINE...BTC/SK/TL







AREA FORECAST DISCUSSION

NWS WILMINGTON NC

 855 PM EST MON NOV 28 2011

.SYNOPSIS...
A STORM SYSTEM APPROACHING THE AREA FROM THE GULF COAST STATES WILL
BRING SHOWERS AND A FEW THUNDERSTORMS ACROSS THE AREA THROUGH
TUESDAY MORNING. THE ASSOCIATED COLD FRONT WILL PUSH THROUGH DURING
TUESDAY ALLOWING COOLER AND DRIER AIR TO INFILTRATE THE AREA IN ITS
WAKE. HIGH PRESSURE WILL BUILD ACROSS THE EASTERN CAROLINAS
WEDNESDAY THROUGH FRIDAY...THEN GIVE WAY TO THE NEXT DRY COLD
FRONTAL PASSAGE FRIDAY NIGHT. COOL HIGH PRESSURE WILL AFFECT THE
AREA THIS WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 845 PM EST MONDAY...MADE ADJUSTMENTS TO PCPN COVERAGE ACROSS
THE ILM CWA. AT THE MOMENT...LOOKING AT 2 DISTINCT BROKEN LINES OF
CONVECTION. WITH THE 1ST MOVING ACROSS THE WESTERN HALF OF THE ILM
CWA...WITH THE MAIN LINE BEHIND THE 1ST. THE MAIN LINE WILL OVERTAKE
AND MESH WITH THE 1ST LINE LATER THIS EVENING...AND BECOME THE MAIN
LINE OF CONVECTION AFFECTING THE AREA OVERNIGHT. LATEST HRRR
INDICATES THE BACK EDGE OF THE CONVECTION WILL BE EXITING THE ILM
CWA TO THE EAST BETWEEN 13Z-15Z TUESDAY. POSSIBLY LATER DUE TO
LATEST HRRR TRENDS DURING THIS EVENING WHICH KEEPS DELAYING ITS
PASSAGE. WITH THIS CURRENT TREND...HAVE ALSO INCREASED MIN TEMPS
ACROSS THE FA DUE TO THE LATER PASSAGE OF THE PCPN ACTIVITY.

PREVIOUS DISCUSSION..............................................
AS OF 300 PM MONDAY...A SURFACE LOW POSITIONED OVER KY BY NIGHTFALL
ENROUTE NORTHWARD WILL MOVE TO OHIO BY DAYBREAK TUESDAY. EXTENSIVE
SE FETCH OF WIND FLOW WILL CONTINUE TO OVER SPREAD THE REGION WITH
MILD AND HUMID AIR AHEAD OF THE PARENT UPPER LOW MUCH OF THE EVE.
WARM SECTOR SHOWERS WILL INCREASE THIS EVENING AND OVERNIGHT AS THE
UPPER SYSTEM TRACKS GENERALLY NE ALONG THE APPALACHIA SPINE TONIGHT
INTO EARLY TUESDAY.

OVERNIGHT A COLD FRONT WILL CROSS OUR WARNING AREA FROM SW TO NE
BRINGING A WINDSHIFT FROM SE TO SW IN THE MIDDLE EVENING OVER THE
FAR INTERIOR...TO AROUND CAPE LOOKOUT NE OF OUR FORECAST ZONES BY
DAYBREAK TUESDAY.

LIMITING CONVECTIVE PARAMETERS ARE THE NOTABLY ARID AIR PERCHED
ABOVE 800MB AND MEAGER INSTABILITY THROUGH PASSAGE OF THE SYSTEM.
DEEP CONVECTION IS NOT LIKELY AND TOPS WILL REMAIN LOW. A NARROW
WINDOW OF DEEP MOISTURE IN THE COLUMN WILL TRAVERSE THE AREA JUST
AHEAD OF THE COLD FRONT. STRONG KINEMATICS AND NOTEWORTHY HELICITY
FIELDS...COULD PROMPT SOME STRONG WIND GUSTS OVER OUR AREA...AND
ISOLATED "SEVERE SHOWERS" CANNOT BE RULED OUT AS WELL...MAINLY
EVENING AND OVERNIGHT. WE MAY NOT EVEN SEE ANY LIGHTNING OVER LAND
WITH THIS SYSTEM GIVEN THE SHALLOW MOISTURE AND LOW CAPE VALUES BUT
AM RELUCTANT TO REMOVE THUNDER DUE TO SHEAR ENERGY OF THE SYSTEM.
WILL CONFINE SLIGHT CHANCE OF THUNDER ACROSS LAND ZONES FOR THE
TONIGHT/OVERNIGHT PERIOD SHIFTING NE INTO EARLY TUESDAY MORNING.

MINIMUM TEMPS BY FIRST LIGHT OF TUESDAY WITH COLD ADVECTION ALREADY
IMPINGING THE S AND W ZONES SHOULD RANGE ROUGHLY FROM THE UPPER 40S
OVER THE WRN SC ZONES TO THE MIDDLE AND UPPER 50S ALONG THE NORTH
COAST AND NE INTERIOR.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...THE NAM...GFS AND ECMWF ARE IN FAIRLY GOOD
AGREEMENT WITH THE HANDLING TO THE CUT-OFF LOW AT 500 HPA THROUGH
48 HOURS. AFTER 48 HOURS...THE NAM`S REPRESENTATION OF THE SURFACE
LOW TRAILS THE OTHER MODELS AT 48H. AT THE SURFACE THESE THREE
MODELS ARE VERY SIMILAR WITH THE OCCLUDED LOW AS THEY MOVE THE LOW
FROM NORTHERN GEORGIA TO LAKE ERIE BY LATE WEDNESDAY NIGHT. BY 12
UTC TUESDAY...THE COLD FRONT AND ITS ASSOCIATED PRECIPITATION
SHIELD WILL BE OVER THE NORTHERN SECTIONS FOR THE FORECAST AREA
AND MOVING OUT OF THE AREA BEFORE NOON. AFTER THE FRONT SHIFTS
EAST-NORTHEASTWARD COOLER AIR WILL SPILL IN AND MAXIMUM
TEMPERATURES WILL STRUGGLE TO GET OUT OF THE UPPER 50S TO NEAR 60
ON TUESDAY AND ONLY IN THE UPPER 50S WEDNESDAY. LOW TEMPERATURES
ARE EXPECTED TO REMAIN IN THE MID TO UPPER 30S. &&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...SHORTWAVE WILL CROSS THE AREA THURS MORNING WITH
MID TO UPPER RIDGE BUILDING UP THE SOUTHEAST COAST LATE THURS
THROUGH SAT. AT THE SURFACE...HIGH PRESSURE WILL BUILD IN ON THURS.
THE CENTER OF HIGH WILL REMAIN WEST OF AREA WITH A DEEP NORTHERLY
FLOW OF COOL AND DRY AIR LASTING THROUGH SATURDAY. A WEAK MOISTURE
STARVED BOUNDARY MAY SLIDE SOUTH LATE FRI INTO EARLY SAT AS EVIDENT
IN MOISTURE AND WIND FIELDS BUT RIDGE BUILDING UP THE COAST MAY HOLD
IT OFF TO THE NORTH AND EAST AND OVERALL EFFECT WILL NOT BE MUCH.
MOISTURE WILL BE LIMITED AS PCP WATER VALUES WILL BE DOWN CLOSE TO A
QUARTER OF AN INCH WITH A SPIKE UP NEAR A HALF INCH AS FLOW COMES
AROUND FROM THE N-NW TO NE BY SAT NIGHT. OVERALL MAY SEE SOME CLOUDS
AS SHORTWAVE MOVES THROUGH ON THURS AND ASSOCIATED WITH BACK DOOR
FRONTAL BOUNDARY LATE FRI BUT NOT EXPECTING ANY PCP THROUGH THE
FIRST HALF OF THE WEEKEND AND SHOULD SEE A GOOD DEAL OF SUNSHINE.
GRADIENT RELAXES THROUGH THE WEEKEND AS HIGH PRESSURE EXTENDS DOWN
INTO THE CAROLINAS.

RIDGE SHIFTS OFF SHORE SUNDAY INTO MONDAY WITH A RETURN FLOW SETTING
UP ALOFT BUT THE SURFACE FLOW WILL BE A LITTLE SLOWER TO COME AROUND
AS CENTER OF HIGH SHIFTS OFF THE NEW ENGLAND COAST EARLY SUNDAY WITH
RIDGE EXTENDING SW DOWN INTO THE CAROLINAS MAINTAINING A NE TO E
FLOW THROUGH SUNDAY. BY MONDAY A DEEPER SOUTHERLY RETURN FLOW SETS
UP FROM THE SURFACE UP THROUGH THE MID TO UPPER LEVELS. PCP WATER
VALUES INCREASE THROUGH SUNDAY UP CLOSE TO THREE QUARTERS OF INCH
AND THEN UP TOWARDS 1.5 INCHES IN INCREASINGLY MOIST SOUTHERLY FLOW
LATE MONDAY INTO EARLY TUES AHEAD OF APPROACHING COLD FRONT.

AS FOR TEMPS...BEST CAA THROUGH THE PERIOD WILL COME IN DEEP
NORTHERLY FLOW ONCE SHORTWAVE CLEARS THE COAST ON THURS. H5 HEIGHTS
WILL INCREASE AS RIDGE BUILDS LATE THURS INTO THE WEEKEND. EXPECT
850 TEMPS TO DROP THURS WITH STEADY READINGS OR SLIGHT INCREASE
THEREAFTER. WITH PLENTY OF DRY AIR IN PLACE AND DEWPOINT TEMPS BELOW
40 IN MOST PLACES THURS THROUGH SUNDAY...EXPECT LARGER DIURNAL
SWINGS WITH TEMPS MAKING IT TO 55 TO CLOSE TO 60 FOR HIGHS AND DOWN
BELOW 40 MOST NIGHTS. WARMING TREND BEGINS EARLY NEXT WEEK WITH
TEMPS REBOUNDING CLOSER TO 70 BY MONDAY.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...ISOLATED TO SCATTERED -SHRA ACTIVITY CONTINUES TO SPREAD
ACROSS WESTERN PORTIONS OF THE CWA AS DEPICTED BY CURRENT RADAR.
ANTICIPATE THIS TREND TO PERSIST OVER THE NEXT COUPLE OF
HOURS...WITH RAINFALL COVERAGE INCREASING ACROSS THE AREA AHEAD OF
AN ADVANCING COLD FRONT. SOUTHEAST WINDS WILL CONTINUE AOB
12KTS...WITH INCREASING WIND GUSTS AOB 25 KTS.

CURRENT GUIDANCE AND FCST SOUNDINGS SUGGEST THE FROPA WILL OCCUR
LATE TONIGHT INTO THE OVERNIGHT HOURS...AS IT PROPAGATES WEST TO
EAST. LOW CONFIDENCE REGARDING EXACT TIMING OF PASSAGE...BUT EXPECT
MVFR SHRA/TSRA...WITH PERIODS OF IFR POSSIBLE IN HEAVIER DOWNPOURS.
GIVEN LOW INSTABILITY VALUES...THE PROBABILITY OF WIDESPREAD TSRA IS
UNLIKELY...HOWEVER CANNOT RULE OUT ISOLATED CONVECTION...THUS HAVE
KEPT IN VCTS AND CB IN FCST. LOCAL WRF MODEL SUGGESTS SHOWERS AND
ISOLATED THUNDERSTORMS WILL CONTINUE THROUGH TUESDAY MORNING. AFTER
14Z APPROXIMATELY...ANTICIPATE CONDITIONS TO IMPROVE TO VFR FOR
REMAINDER OF VALID PERIOD...THOUGH AREAS OF MVFR CIGS MAY STILL
LINGER TUESDAY MID-MORNING. EXPECT WINDS TO GRADUALLY SHIFT MORE
WEST-SOUTHWEST TUESDAY MORNING...WITH PERIODS OF GUSTY WINDS AOB
20KTS.

EXTENDED OUTLOOK...EXPECT VFR THROUGH PERIOD.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 845 PM MONDAY...MID 70S SSTS LURKING JUST OFFSHORE FROM THE
ILM COASTAL WATERS...WITH 41013 AND 41004 BUOYS EXHIBITING THESE
WARM TEMPS. NEAR SHORE...LOW TO MID 60S REMAIN COMMON PER LATEST
OMRILM REPORTS. THE GRADIENT WINDS WILL FURTHER INCREASE ACROSS ALL
OF THE ILM WATERS THROUGH THE NIGHT TO STRONG SCA CRITERIA. HOWEVER
THE 30 TO 40 KT WINDS JUST OFF THE DECK VIA LATEST KLTX VWP...WILL
HAVE A DIFFICULT TIME REACHING THE OCEAN SFC...EVEN AS WIND
GUSTS...DUE TO THESE COOLER SHELF WATERS. THESE HIGHER WINDS JUST
OFF THE DECK ARE LIKELY MAKING IT TO THE OCEAN SFC EITHER AS
SUSTAINED AND/OR AS WIND GUSTS VIA THE LATEST 41013 AND 41004 LATEST
REPORTS. THE BIG KAHUNAS IN DC ARE ON THE BALL WITH THE GALE WARNING
FOR THE OFFSHORE WATERS ADJACENT TO THE ILM COASTAL WATERS.

HAVE INCREASED SEAS AND ALLOWED THEM TO LAST LONGER ACROSS THE ILM
WATERS OVERNIGHT INTO EARLY TUE...BEFORE SLOWLY BEING BEATEN DOWN
LATER IN THE DAY. THIS DUE TO THE HIGHER SE-SW WINDS JUST OFFSHORE
PRODUCING THE HIGHER SEAS WHICH CONTINUALLY BLEED INTO THE ILM
COASTAL WATERS.

PREVIOUS DISCUSSION.................................................
AS OF 300 PM MONDAY...ROUGH CONDITIONS ON THE WATERS AND ADVISORIES
POSTED THROUGH MUCH OF TUESDAY DUE TO MOUNTING SE WAVES AND STRONG
S-SE WINDS OVERNIGHT. ANY TSTMS OR STRONG SHOWERS THAT MANAGE TO
FORM OVER THE WATERS WILL CERTAINLY BE CAPABLE OF GENERATING SEVERE
WIND GUSTS JUST OFF STORM MOTION ALONE. SPECTRUM ANALYSIS DEPICTS
BUILDING SE WAVES OF 6-11 FEET...HIGHEST OFFSHORE...TONIGHT IN 7-8
SECONDS INTERVALS. THUS SCA CONDITIONS THROUGH ALL OF THE NEAR TERM
FORECAST PERIOD. CHILLY SEA SURFACE TEMPS NEAR SHORE WILL LIKELY
RESULT IN THE STRONGEST WINDS HOLDING OFFSHORE...BUT INTENSIFYING SE
WAVE ENERGY WILL PROPAGATE NEAR SHORE. WE MAY SEE LARGE STANDING
WAVES THROUGH INLETS DURING OUTGOING TIDES THAT HAVE SE EXPOSURE.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...THE FORECAST PERIOD WILL BEGIN WITH THE SURFACE
COLD FRONT CROSSING THE WATERS AND WINDS BLOWING FROM WEST TO
SOUTHWEST AT 15 TO 20 KNOTS WITH A QUICK INCREASE IN WINDS WITH A
SHOT OF COLD AIR ADVECTION BY NIGHTFALL.  SEAS ARE EXPECTED TO
REMAIN AT SMALL CRAFT CONDITIONS RANGE THROUGH TUESDAY NIGHT BEFORE
SLOWLY FALLING BELOW CRITERIA. WINDS WILL BE WESTERLY ON WEDNESDAY
AND WILL SHIFT TO THE NORTHWEST AS THE FINAL TROUGH FROM THE UPPER
LEVEL SYSTEM THAT PAST TO THE NORTHWEST OF THE WATERS ON TUESDAY.

LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...ONCE SHORTWAVE CLEARS THE WATERS ON
THURS...HIGH PRESSURE WILL BUILD IN WITH RIDGE BUILDING ALOFT
THROUGH THE PERIOD. OVERALL EXPECT DEEP COOL NORTHERLY FLOW
THROUGH MOST OF THE PERIOD. WINDS WILL VEER SLIGHTLY FROM N TO NE
BY SAT NIGHT AS CENTER OF HIGH PRESSURE SHIFTS OFF THE NEW ENGLAND
COAST. GRADIENT MAY RELAX LATE THURS THROUGH FRI AS ONE AREA OF
HIGH PRESSURE MOVES OFF SHORE BUT WILL TIGHTEN AGAIN FRI NIGHT
INTO SAT AS WEAK BACK DOOR FRONT MOVES SOUTH WITH SECOND AREA OF
HIGH PRESSURE BUILDING IN FOR SAT. THEREFORE NORTHERLY WINDS
AROUND 15 KTS ON THURS MAY DECREASE TO 10 TO 15 KTS BY FRI BEFORE
INCREASING AGAIN TO A SOLID 15 KTS IN THE OUTER WATERS FRI NIGHT
INTO SAT. THE ALONG SHORE WINDS WILL CREATE HIGHER SEAS OFF SHORE
THROUGH THE PERIOD. EXPECT SEAS CLOSER TO 1 TO 2 FT NEAR SHORE AND
3 TO 4 OUTER WATERS WITH SOME 5 FOOTERS CREEPING IN SAT MORNING IN
NORTHERLY SURGE.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST TUESDAY FOR AMZ250-252-
     254-256.

&&

$$

NEAR TERM...DCH/MJC
SHORT TERM...HAWKINS
LONG TERM...RGZ
AVIATION...SGL









AREA FORECAST DISCUSSION

NWS NEWPORT/MOREHEAD CITY NC

 846 PM EST MON NOV 28 2011

.SYNOPSIS...
A COLD FRONT WILL SWEEP THROUGH THE AREA TUESDAY MORNING FROM THE
WEST. HIGH PRESSURE WILL BUILD INTO NORTH CAROLINA WEDNESDAY
THROUGH THURSDAY. ANOTHER COLD FRONT WILL PASS THROUGH THE REGION
FRIDAY NIGHT. HIGH PRESSURE WILL ONCE AGAIN BUILD INTO THE AREA
NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 8 PM MON...MOIST SELY FLOW CONTINUES ACROSS THE REGION THIS
EVEING AHEAD OF A STRONG COLD FRONT PRESENTLY PUSHING ACROSS SC
WITH ASSOC UPPER LOW SLOWLY PUSHING ACROSS NRN MS/AL AND S CNTRL
TN. 00Z KMHX SOUNDING SHOWS FAIRLY MOIST BELOW 800 MB BUT REMAINS
DRY ABOVE WITH PW`S SIMILAR TO THIS MORNING AROUND 0.85". DON`T
THINK WE WILL SEE MORE THAN AN ISOLATED LIGHT SHOWER THROUGH THE
REMAINDER OF THE EVENING WITH MOISTURE REMAINING SHALLOW AND HAVE
REDUCED POPS TO 20% THROUGH MIDNIGHT WITH THIS UPDATE...AND MAY
NEED TO PUSH BACK A FEW HOURS LATER UNTIL BETTER FORCING MOVES
INTO THE REGION LATE TONIGHT. LATEST HRRR MODEL RUN INDICATING
STRONGER FORCING/HEAVIER PCPN PUSHING INTO DUPLIN CO AROUND 3 AM
AND TO NEAR A CAPE LOOKOUT TO GREENVILLE LINE BY 6 AM.

AS THE FRONT MOVES EAST OVERNIGHT...LLJ WILL INC TO AOA 40 KT WITH
PWATS INC TO AROUND 1.5 INCHES. TREMENDOUS KINEMATICS WILL BE IN
PLACE WITH THE COLD FRONT...THOUGH LACKING INGREDIENT WILL BE
INSTABILITY. STILL...AN ISOLATED EMBEDDED STORM IS STILL POSSIBLE
AS FORCING WILL BE VERY STRONG... AND MAY PRODUCE LOCALLY DAMAGING
WIND GUSTS.

TEMPS THIS EVENING HAVE FALLEN INTO THE M/U60S AND DON`T EXPECT
THEM TO DROP MUCH MORE OVERNIGHT AS STRONG WAA PERSISTS AHEAD OF
THE FRONT...THE EXCEPTION BEING FAR WRN PORTION OF THE CWA WHERE
THE FRONT IS EXPECTED TO REACH BY 6 AM AND COULD SEE TEMPS FALLING
TO AROUND 60 AFTER FROPA.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AS OF 3 PM MON...LINE OF SHOWERS WILL TRANSLATE EAST INTO THE
REST OF THE FA THROUGH THE MORNING ON TUE...REACHING THE OBX
AROUND THE NOON HOUR. AN ISO THUNDERSTORM WILL STILL BE
POSSIBLE...THOUGH STRONG CAA WILL LIMIT THE POTENTIAL FOR ANYTHING
MORE THAN AN ISO MENTION. DAYTIME HIGHS IN THE 60S WILL BE
REALIZED TUE MORNING...WITH TEMPS FALLING FROM WEST TO EAST
THROUGHOUT THE DAY BEHIND THE FROPA. BY AFTERNOON MANY AREAS WILL
HAVE DROPPED WELL INTO THE 50S. RAIN WILL CLEAR OUT FOR MOST AREAS
EXCEPT THE OBX BY EARLY AFTERNOON...WITH ONLY SOME SCT SHOWERS
REMAINING.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
CUTOFF LOW MOVES QUICKLY NORTH UP THE APPALACHIANS TUE NIGHT. WEAK
SFC RIDGE BUILDS ACROSS THE AREA TUE NIGHT IN THE WAKE OF COLD
FRONTAL PASSAGE. ANY LINGERING SHOWERS WILL BE ENDING OVER THE OUTER
BANKS EARLY TUE EVENING AS THE MID LEVEL DRYING MOVES TO THE COAST.
MUCH COOLER AIR WILL WORK INTO THE AREA AROUND THE DEPARTING UPPER
LOW WITH LOW TEMPS TUE NIGHT FALLING INTO THE 30S INLAND WITH
LOW-MID 40S AT THE COAST.

BELOW NORMAL TEMPERATURES WILL HIGHLIGHT THE WED THRU SAT TIMEFRAME
AS SEVERAL REINFORCING SHOTS OF COOLER AIR INVADE THE AREA. MOISTURE
WILL BE TOO SCARCE FOR ORGANIZED PCPN BUT MAY SEE CLOUDY INTERVALS
AS WEAK SHORT WAVES PASS THRU THE AREA.

TEMPERATURES WILL BEGIN TO MODERATE LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK AS RETURN FLOW GRADUALLY SETS UP AHEAD OF DOWNSTREAM
TROF. TIMING OF PCPN CHCS MAY BE TIED TO PROGRESSIVENESS OF LARGE
SCALE TROF BEING CARVED OUT OVER THE UPPER MIDWEST EARLY NEXT WEEK.
WILL KEEP THE DAY 7 FCST DRY FOR NOW UNTIL THE TIMING OF THIS
DOWNSTREAM FEATURE CAN BE BETTER RESOLVED.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH TUESDAY/...
AS OF 8 PM MON...VFR CONDITIONS CONTINUE THIS EVENING WITH MOIST
SELY FLOW PERSISTING BELOW 7K FT. LLJ WILL INC TO ABOVE 30 KT BY
06Z...AND NON CONVECTIVE LLWS MAY BE AN ISSUE AS SFC FLOW REMAINS
BELOW 10 KT. LARGE UPR CLOSED LOW AND ASSOCIATED COLD FRONT WILL
APPROACH AND PASS THROUGH E NC AFTER 12Z...WITH A PERIOD OF HEAVY
SHOWERS AND AN ISO THUNDERSTORM LIKELY. CIGS/VSBYS WILL TEMPORARILY
BE RESTRICTED TO IFR AS THE SHOWERS MOVE THROUGH. AT THIS TIME IT
LOOKS LIKE THE WINDOW FOR FLIGHT RESTRICTIONS AT THE TERMINALS WILL
BE AROUND 09Z THROUGH 16Z...WITH CONDITIONS IMPROVING THEREAFTER.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
VFR CONDITIONS EXPECTED FOR A LARGE PART OF THIS FCST PERIOD AS
DRIER AIR FILTERS INTO THE REGION. MAY BE SOME CLOUDY INTERVALS DUE
TO WEAK SHORT WAVE PASSAGES BUT EXPECT CLOUD BASES WILL BE HIGHER
THAN 3K FT FOR THE MOST PART. MAY ALSO SEE BRIEF/PATCHY LATE
NIGHT/EARLY MORNING RADIATION FOG AS DEW POINT DEPRESSIONS LOWER
LATER IN THE WEEK.

&&

.MARINE...
SHORT TERM /THROUGH TUESDAY/...
AS OF 8 PM MON...WINDS AND SEAS GRADUALLY INCREASING THIS EVENING
AHEAD OF A STRONG COLD FRONT PRESENTLY PUSHING ACROSS SC. FORECAST
LOOKS ON TRACK WITH WINDS AROUD 15-20 KT SRN AND CENTRAL WATERS
AND 10-15 KT ELSEWHERE. SEAS ARE ALSO BUILDING ACROSS SRN/CENTRAL
WATERS WHERE BUOY 41036 NOW UP TO 8FT. GRADIENT INC FURTHER AS
THE STRONG COLD FRONT APPROACHES LATE TONIGHT...AND WINDS AND SEAS
WILL CONTINUE TO INC. SEAS WILL INC AND BUILD FROM S TO N...WITH
SCA CONDITIONS BEING MET FOR THE NORTHERN WATERS BY EARLY TUE
MORNING. KEPT SCA OUT OF THE SOUNDS FOR NOW...AS THE COOLER WATERS
SHOULD KEEP WINDS JUST BELOW THE 25 KT THRESHOLD...THOUGH GUSTS
MAY GET CLOSE TO THAT BY EARLY TUE MORNING. WINDS WILL VEER FROM
SE TO SW BEHIND THE COLD FRONT LATE TUE MORNING THROUGH AFTERNOON.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODERATE (15-20KT) SW/W WINDS TUE NIGHT/WED WILL SHIFT MORE NW/N AT
ROUGHLY THE SAME SPEEDS AS WEAK SFC TROF PASSES ON THURSDAY. SEAS
WILL INITIALLY FALL BLO SMALL CRAFT ADVISORY LEVELS (6 FT) FOR A
TIME LATE WED/WED NIGHT BEFORE BUILDING BACK ABV 6 FT AGAIN AS WINDS
BECOME MORE NORTHERLY AND CONTINUE AT MODERATE LEVELS THU-SAT.
THEREFORE SMALL CRAFT ADVISORIES MAY AGAIN BE REQUIRED LATER IN THE
WEEK...MAINLY FOR SEAS.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR AMZ152-154.
     SMALL CRAFT ADVISORY UNTIL 4 PM EST WEDNESDAY FOR AMZ156-158.
     SMALL CRAFT ADVISORY FROM 5 AM TUESDAY TO 5 AM EST WEDNESDAY
     FOR AMZ150.

&&

$$
SYNOPSIS...TL
NEAR TERM...SK/TL
SHORT TERM...TL
LONG TERM...BTC
AVIATION...BTC/SK/TL
MARINE...BTC/SK/TL







AREA FORECAST DISCUSSION

NWS WILMINGTON NC

 224 AM EST SUN NOV 27 2011

.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO MIGRATE OFFSHORE THROUGH THE
REMAINDER OF THE WEEKEND. A STORM SYSTEM WILL SLOWLY APPROACH THE
AREA FROM THE GULF COAST STATES...CREATING UNSETTLED WEATHER
MONDAY THROUGH EARLY TUESDAY. COOLER AND DRIER AIR WILL FIND ITS
WAY INTO THE REGION MID THROUGH LATE WEEK AS HIGH PRESSURE BUILDS
ACROSS THE EASTERN CAROLINAS.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 2:30 AM SUNDAY...DEEP...NEARLY CUT-OFF H/5 LONG WAVE TROUGH
PUSHING EAST ACROSS THE DEEP SOUTH WILL DRIVE A FRONTAL SYSTEM
CLOSER TO THE FORECAST AREA AS HIGH PRESSURE CENTERED EAST OF CAPE
HATTERAS MOVES FURTHER OFFSHORE. GUIDANCE SUGGESTS A WARM FRONT
WILL BE ALIGNED ALONG THE COASTAL CAROLINAS BY DAYBREAK SUNDAY.
SOUTHERLY FLOW AND MOISTURE ADVECTION WILL INCREASE AS GRADIENT
TIGHTENS IN ADVANCE OF FRONTAL SYSTEM...KEEPING TEMPERATURES UP
ABOVE NORMAL TODAY AND TONIGHT. LOOKING FOR HIGHS IN THE LOWER TO
MID 70S TODAY...WITH LOWS IN THE MID 50S OVERNIGHT. MOISTURE
INCREASE WILL BE LIMITED TO THE LOWER LEVELS WITH MID LEVELS
REMAINING QUITE DRY. SATELLITE LOOPS AND MODEL SOUNDINGS SHOW
THERE WILL BE ENOUGH UPPER LEVEL MOISTURE FOR AN INCREASE IN
CIRRUS. HOWEVER...MOST NOTICEABLE INCREASE IN CLOUDS WILL BE AT THE
LOWEST LEVELS AS THE NEAR TERM WEARS ON. PRECIP CHANCES LIMITED TO
SLIGHT CHANCE OR LOW CHANCE FOR SHOWERS EARLY MONDAY MORNING DUE
TO LIMITED DEEP MOISTURE AND WEAK FORCING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 2:30 AM SUNDAY...A DEEP AND FAIRLY COLD/-25C/ 500MB CUTOFF
LOW WILL PROGRESS SLOWLY ACROSS THE GULF STATES ON MONDAY. AHEAD
OF THIS SYSTEM IN THE LOW LEVELS A NARROW BUT STRONG/INTENSE BAND
OF WARM AND MOIST ADVECTION WILL DEVELOP. THE EXACT TIMING THAT
THIS WAA ZONE CROSSES OUR LONGITUDE HAS BEEN UNCERTAIN FOR DAYS
NOW BUT FINALLY APPEARS TO HAVE CONGEALED INTO A WINDOW A FEW
HOURS EITHER SIDE OF 06Z TUESDAY. THE SURFACE AIRMASS WILL REMAIN
QUITE DRY UNTIL THIS RIBBON OF MOISTURE AND FORCING ARRIVES TO
PRECIP CHANCES LOOK PRETTY SLIM. THE NIGHTTIME PASSAGE OF THE RAIN
WILL MEAN THAT INSTABILITY WILL BE AT A MINIMUM. THIS IS FORTUNATE
SINCE MID AND UPPER WIND FIELDS WILL GROW VERY STRONG AND DEEP
CONVECTION WOULD READILY TURN SEVERE. LOW LEVEL WIND FIELDS WILL
ALSO BE QUITE STRONG MEANING MONDAY NIGHT WILL PROBABLY BRING A
LINE OF MODERATE TO OCCASIONALLY HEAVY RAINFALL ACROSS THE REGION.
EMBEDDED IN THIS LINE WILL BE SOME SHALLOW CONVECTIVE ELEMENTS
THAT MAY CONTAIN STRONG BUT MAINLY SUB-SEVERE WIND GUSTS.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 2:30 AM SUNDAY...WEAK HIGH BUILDS IN FROM THE WEST WED AND
THUR WHILE AN UPPER LOW MOVES ACROSS AS WELL ON THURS. THIS
FEATURE WILL BE MOISTURE DEPRIVED AND THUS OF LITTLE CONSEQUENCE.
TEMPERATURES A LITTLE BLOW CLIMO THROUGHOUT. MORE WEAK COOL
ADVECTION IN A SPLIT UPPER FLOW REGIME WILL ROUND OUT THE LONG
TERM. TEMPS WILL STAY ON THE COOL SIDE OF CLIMO AND RAIN FREE
CONDITIONS CONTINUE.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...MODERATE CONFIDENCE FORECAST OVERNIGHT DUE TO CIGS AND
FOG POTENTIAL. WIDESPREAD CLOUDINESS IS LIKELY ALL DAY SUNDAY...BUT
WITH VFR.

NAM BUFR PROFILES ARE STILL ERRONEOUSLY FORECASTING IFR...SO WILL
CONTINUE TO DISREGARD THEM. LATEST HRRR APPEARS TO BE INITIALIZING
QUITE WELL THE CIGS...SO WILL BLEND WITH GFS FORECAST SOUNDINGS AND
OBS FOR THIS TAF PACKAGE.

WIDESPREAD STRATUS/STRATOCU OVERSPREADING MUCH OF THE SOUTHEAST
ATTM...AND EXPECT THIS TO CONTINUE OVERNIGHT AS LIGHT SOUTHERLY FLOW
ADVECTS MOISTURE INTO THE COLUMN. 00Z SOUNDINGS FROM CHS SHOWED A
PRONOUNCED INVERSION AT AROUND 4500 FT...SO EXPECT MOST OF THE
STRATUS TO REMAIN IN THE 4-5 KFT LEVEL OVERNIGHT...WHICH MATCHES
WELL WITH CURRENT OBS. STILL SOME CONCERN FOR FOG IF CIGS DO NOT
FILL IN AS RAPIDLY AS ANTICIPATED...BUT FOG THREAT HAS DECREASED
ENOUGH THAT MENTION OF VSBY RESTRICTIONS HAS BEEN REMOVED. EXPECT
BKN/OVC 4-5 KFT CIGS THROUGH THE OVERNIGHT.

WIDESPREAD STRATUS/STRATOCU WILL PERSIST ALL DAY SUNDAY WITH LOW-VFR
CIGS. WINDS WILL REMAIN SOUTHERLY ON RETURN FLOW...INCREASING TO
AROUND 10 KTS IN THE AFTN. NO SIGNIFICANT CHANGES AFTER NIGHTFALL
SUNDAY EITHER...AS CIGS WILL PERSIST AND WINDS WILL REMAIN ELEVATED
DUE TO TIGHTENING PG AHEAD OF AN APPROACHING STORM SYSTEM.

EXTENDED OUTLOOK...LOW CONFIDENCE IN STRATUS OVERNIGHT SUNDAY.
SHOWERS/TEMPO MVFR/IFR LIKELY MONDAY AND TUESDAY. VFR WEDNESDAY AND
THURSDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2:30 AM SUNDAY...SELY WINDS WILL GRADUALLY INCREASE IN
ADVANCE OF A FRONTAL SYSTEM TODAY AND TONIGHT...WITH 15 TO 20 KTS
DEVELOPING BY DAYBREAK MONDAY. SEAS WILL SLOWLY BUILD AS A
RESULT...WITH SOME 6 FOOTERS APPEARING BY THE END OF THE NEAR
TERM...ALTHOUGH INITIALLY SEAS IN THE 3 TO 5 FT RANGE WILL BE
MORE COMMON. HAVE HOISTED SMALL CRAFT ADVISORY DUE TO ONSET OF 6
FT SEAS STARTING LATE TONIGHT.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 2:30 AM SUNDAY...SMALL CRAFT ADVISORY WILL BE IN EFFECT ON
MONDAY IN STRONG PREFRONTAL REGIME AHEAD OF VERY DEEP UPPER LOW
AND SURFACE CYCLONE CROSSING THE NRN GULF STATES. THE COLD FRONT
ASSOCIATED WITH THESE SYSTEMS WILL CROSS THE WATERS JUST AFTER
MIDNIGHT MONDAY NIGHT. WIND WILL VEER BUT NOT SO ABRUPTLY AS ONE
MIGHT EXPECTED. RATHER THAN THE USUAL `CLEAN` FROPA CYCLONIC FLOW
WILL LINGER AS THE SURFACE WAVE ROTATES AROUND THE CENTER OF THE
LOW ALOFT...PINWHEELING IT N ACROSS GA AND ERN TN AND THEN
WESTWARD FROM THERE. THIS WILL TRANSLATE INTO AN EROSION OF
FORECAST CONFIDENCE INTO TUESDAY. NOT ONLY IS THIS EVOLUTION A
LITTLE ON THE UNCOMMON SIDE BUT IT WILL ALSO LEAD TO SEVERAL HOURS
OF LIGHTER WINDS (AND THUS DIMINISHING SEAS) FOLLOWED ONCE AGAIN
BY AN INCREASE IN WINDS AS THE COLD SURGE ENSUES. THE COMPLICATION
WILL HAVE TO DO WITH THE EXPIRATION OF ANY HEADLINES...WHICH MAY
NOT BE WARRANTED NOW THROUGH THE SPAN OF THE SHORT TERM PERIOD.

LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 2:30 AM SUNDAY...MUCH LIGHTER WINDS ON TAP FOR THE LONG TERM
AS HIGH PRESSURE SETTLES IN FROM THE WEST. NOT BEING A VERY STRONG
HIGH THERE WILL ONLY BE A MODERATE GRADIENT IN PLACE ON ITS
EASTERN PERIPHERY. THIS HIGH WILL STAY TO OUR WEST ON THURSDAY AS
AN UPPER DISTURBANCE CROSSES THE AREA. THIS COULD YIELD JUST
ENOUGH LOWERING OF PRESSURE WELL OFF THE COAST TO TIGHTEN THE
GRADIENT SLIGHTLY ACROSS THE FORECAST AREA.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 3 AM MONDAY TO 7 AM EST TUESDAY FOR
     AMZ250-252-254-256.

&&

$$

SYNOPSIS...REK
NEAR TERM...REK
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...JDW
MARINE...REK/MBB





AREA FORECAST DISCUSSION

NWS GRAND FORKS ND

 901 PM CST MON NOV 28 2011

.UPDATE...
REALLY NO REASON TO CHANGE THE CURRENT FORECAST. WINDS ARE
DIMINISHING AND SKIES WILL REMAIN MAINLY CLEAR. SO LOWS SHOULD
FALL CLOSE TO 10 IN THE NORTH AND NEAR 20 SOUTH. LATEST GUIDANCE
JUST COMING IN ARE A FEW DEGREES WARMER THAN CURRENT FORECAST
LOWS...BUT SUSPECT DIURNAL BIAS PARTLY AT PLAY.

MODEL RH X-SECT MIMIC IR/WV SATELLITE DEPICTION OF VERY DRY
COLUMN. UPSTREAM AREA OF MID CLOUD MOVING INTO WESTERN DAKOTAS
SLOWLY DECREASING IN COVERAGE. GFS/NAM KEEP MID LEVELS RELATIVELY
DRY SO EXPECT ONLY SCT CLOUDS OVERNIGHT. HRRR HAS BEEN PERSISTENT
IN BRINGING THE BAND OF MID CLOUDS ACROSS THE CWFA AFTER 06Z...YET
SUSPECT ITS A TAD OVERDONE. WILL MAKE TWEAKS FOR TRENDS OTRW
CURRENT FORECAST OK.

&&
.AVIATION...WINDS BCMG L/V OVERNIGHT AND CAVU. ANY CLOUDS WOULD
BE SCT ABV 120.

&&

.PREV DISCUSSION... /ISSUED 241 PM CST MON NOV 28 2011/

SHORT TERM...
COLD FRONT EXITING THE FCST AREA AT 20Z. BRIEF WARMER AIR BEHIND
THE FRONT IN THE WEST WINDS ALSO NOW MOVING MORE INTO WCNTRL MN AS
TEMPS RISE FROM THE UPPER 30S TO MID 40S AT BEMIDJ-WADENA-ELBOW
LAKE. TEMPS STARTING TO COOL A FEW DEGREES OVER ERN ND. LAST OF
THE HIGH CLOUDS WIL CLEAR OUT OF THE SOUTHEASTERN FCST AREA EARLY
THIS EVENING. THIS WILL LEAVE A CLEAR SKY TONIGHT AND WINDS WHICH
ARE GUSTING TO NR 30 KTS BEHIND THE FRONT WILL DIE DOWN TO NR 5
KTS OVERNIGHT AS SFC HIGH MOVES INTO ERN ND/SD NR 06Z.

QUESTION TONIGHT WILL BE LOW TEMPS. MODEL MOS GUIDANCE IS QUITE A
BIT WARMER THAN PREV FCST...15 TO 22 VERSUS 10-16 FROM PREV FCST.
UPSTREAM DEW PTS NOT ALL THAT LOW BUT STILL IN THE TEEENS. LIGHT
WIND AND CLEAR SKY ALONG WITH DRY GROUND WOULD ARGUE FOR LOWER
THAN MOS GUIDANCE TEMPS TONIGHT. BOIVERIFY TEMP STATS SHOWS FOR
MIN TEMPS....GEM MODEL HAS BEEN DOING THE BEST IN THESE SITUATIONS
SO FOLLOWED ITS COLDER ROUTE WHICH HAS SOME SINGLE DIGITS IN THE
FAR NORTH TO MID TEENS IN THE FAR SOUTH AND SOUTHEAST.

WINDS WILL TURN SOUTHERY ON TUESDAY. LOOK FOR PLENT OF SUN WITH
ONLY SOME THIN HIGH CLOUDS AT TIMES. DRY AIRMASS AND DRY GROUND
WILL ALLOW TEMPS TO WARM NICELY BACK INTO THE 30S.

COLD FRONT ARRIVAL FOR WEDNESDAY SEEMS TO HAVE SLOWED A BIT FROM
PREV DAYS THOUGHTS WITH COLD FRONT ALONG THE CANADIAN BORDER AT
15Z WED....THEN DROPPING TO NR A BAUDETTE-GRAND FORKS TO
COOPERSTOWN LINE 18Z-21Z THEN SPREADING SOUTH TOWARD FARGO BY 00Z.
BAND OF MID LEVEL LIFT AND MOISTURE SATURATION OCCURS JUST BEHIND
THE FRONT IN THE COLD ADVECTION. THUS DO LOOK FOR A PERIOD OF
LIGHT SNOW. MODELS SHOW MAIN 500 MB ENERGY SPLITTING SOME AS IT
MOVES TOWARD AREA WED AFTN-EVE WITH MAIN ENERGY DIVING SOUTH INTO
THE CNTRL PLAINS AND WEAKER 500 MB VORT MOVING INTO NRN MN. THUS
PRECIP AMTS DO LOOK TO WEAKEN AS SYSTEM DROPS SOUTHEAST ACROSS THE
FCST AREA. STILL LOOK FOR AN INCH....MAYBE 2 ALONG THE CANADIAN
BORDER TO WELL LESS THAN AN INCH SOUTH OF HIGHWAY 2. BUT COORD
WITH BIS/DLH AND DID UP POPS TO LIKELY RANGE BEHIND FRONT AS
MEASURABLE PRECIP QUITE LIKELY...BUT AMOUNTS LOW. WINDS WILL BE
GUSTY FROM THE NORTH TO 30-35 KTS BEHIND FRONT FOR A TIME.

THURSDAY WILL BE A COLD DAY....BUT LOOKS LIKE COLD ADVECTION IS
PRETTY BRIEF WITH WARM ADV ON THE HEELS ALREADY BY LATE IN THE DAY
IN ERN ND. THIS MAY HELP TEMPS RECOVER SOME FROM WED NIGHT
LOWS...BUT STILL EXPECT MOSTLY 15 TO 25 FOR HIGHS THURSDAY. GFS
MEX GUIDANCE IS QUITE COLDER THAN ALL BLENDS... USED ALL BLENDS
NOW PER COORDINATION....BUT TEMPS THURSDAY MIGHT BE ON THE WARM
SIDE IF TRENDS CONTINUE.

LONG TERM (FRI-MON)...
MODELS IN FAIR AGREEMENT WITH THE EXTENDED PERIOD...UNCERTAINTIES
IN TIMING OF FROPA ON SATURDAY AND THE DURATION AND PLACEMENT OF THE
COLDEST AIR OF THE ARCTIC PUSH SUNDAY AND MONDAY. DEFINITELY
CONTINUED DRY WEATHER OTHER THAN THE CHANCE OF LIGHT SNOW WITH THE
FRONTAL PASSAGE SATURDAY NIGHT INTO SUNDAY. TEMPERATURES ABOVE
NORMAL ON FRI AND SAT WITH RELATIVELY WARMER AIRMASS IN ADVANCE OF
ARCTIC INTRUSION AND THEN BELOW NORMAL SUNDAY AND MONDAY BEHIND THE
FRONT.

AVIATION...
VFR WITH CIRRUS CIGS THIS AFTERNOON AT FAR AND BJI. SKC EXPECTED
OVERNIGHT AS HIGH PRESSURE MOVES IN AND WINDS WEAKEN WITH BOUNDARY
LAYER DECOUPLING AT SUNDOWN.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$
EWENS






AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 255 PM CST SUN NOV 27 2011

.SHORT TERM...TONIGHT THROUGH WEDNESDAY
255 PM CST SUN NOV 27 2011

MAIN FORECAST CONCERN IS ON CLOUDS/TEMPERATURES TONIGHT INTO MONDAY.

CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED TROUGHING OVER BRITISH COLUMBIA...RIDGING FROM SOUTHERN
CALIFORNIA NORTHEASTWARD INTO SOUTHERN MANITOBA...AND TROUGHING FROM
JAMES BAY SOUTHWEST THROUGH WISCONSIN AND DOWN INTO EASTERN TEXAS.
WITH THE FORECAST AREA ON THE WEST SIDE OF THIS LATTER UPPER
TROUGHING...MID TO UPPER LEVEL SUBSIDENCE IS OCCURRING. THIS CAN BE
SEEN ON 12Z SOUNDINGS FROM ABR...MPX AND DVN. ALSO OF NOTE ON THE
MPX AND DVN SOUNDINGS IS A NEAR TO FULLY SATURATED LAYER FROM 910MB
TO AT LEAST 850MB...REPRESENTATIVE OF THE STRATUS DECK IN PLACE AT
THE TIME. LATEST VISIBLE SATELLITE IMAGERY SHOWED THE STRATUS
COVERING THE ENTIRE FORECAST AREA AND EXTENDING WEST TO A
NORTH-SOUTH LINE THROUGH WINDOM MINNESOTA. GOING A LITTLE FARTHER
WEST...A SURFACE RIDGE IS PRESENT ALONG THE DAKOTAS/MINNESOTA
BORDER. NORTHWEST WINDS REMAIN GUSTY AHEAD OF THE RIDGE WITH GUSTS
OF 20-25 KT OVER THE FORECAST AREA. TEMPERATURES HAVE ALSO STRUGGLED
TO RISE MUCH TODAY...DUE TO A COMBINATION OF THE STRATUS LIMITING
DIURNAL HEATING AND 850MB TEMPS OF -9C OBSERVED AT MPX ON ITS 12Z
SOUNDING.

MUCH OF THE SHORT TERM PERIOD LOOKS QUIET FOR THE FORECAST AREA...
THOUGH THERE ARE A FEW FEATURES TO WATCH. FIRST IS THE SOUTHERN END
OF THE CURRENT UPPER TROUGH IN EAST TEXAS. ALL MODELS AGREE ON THE
SOUTHERN END CLOSING OFF INTO AN UPPER LOW OVER THE SOUTHEASTERN
U.S. MONDAY INTO MONDAY NIGHT...WHICH RESULTS IN SURFACE LOW
DEVELOPMENT ON ITS NORTH SIDE OVER KENTUCKY AND TENNESSEE. THE UPPER
AND SURFACE LOWS THEN GET LIFTED NORTHEAST THROUGH THE EASTERN U.S.
FOR TUESDAY INTO WEDNESDAY...IN RESPONSE TO THE CURRENT BRITISH
COLUMBIA TROUGH MOVING THROUGH THE FORECAST AREA ON TUESDAY. AS OF
NOW IT APPEARS ANY DEFORMATION PRECIPITATION ON THE NORTHWEST SIDE
OF THE UPPER AND SURFACE LOWS WILL STAY TO THE SOUTHEAST...THANKS TO
THAT BRITISH COLUMBIA UPPER TROUGH...PERHAPS REACHING AT MOST THE
ROCKFORD ILLINOIS AREA. OTHERWISE...MUCH OF THE REST OF THE TIME THE
FORECAST AREA SHOULD BE DOMINATED BY SUBSIDENCE AND DRY AIR...DUE TO
UPPER RIDGING COMING ACROSS ON MONDAY AND AGAIN TUESDAY NIGHT INTO
WEDNESDAY...RESULTING IN DRY CONDITIONS.

CLOUD COVER FORECAST IS PROBLEMATIC...ESPECIALLY TONIGHT WITH THE
STRATUS STUCK IN PLACE BELOW THE SUBSIDENCE INVERSION. TYPICALLY TO
GET RID OF STRATUS IN THESE CASES...ESPECIALLY THIS TIME OF YEAR
WITH THE VERY LOW SUN ANGLE...THE SURFACE RIDGE NEEDS TO MOVE IN
AND/OR THROUGH. 27.12Z NAM/GFS SEEM TOO AGGRESSIVE BY CLEARING
THINGS OUT BY 21Z IN OUR WESTERN FORECAST AREA TODAY...WHICH IS
ALREADY TOO FAST PER LATEST SATELLITE IMAGERY. FOLLOWED MORE OF AN
IDEA PRESENTED BY THE RUC AND 925MB WIND FORECASTS...WHICH WOULD
SUGGEST CLEARING MAINLY OCCURRING AFTER MIDNIGHT TONIGHT INTO
MID-DAY MONDAY...WORKING FROM NORTHWEST TO SOUTHEAST AS 925MB WINDS
TURN SOUTHWESTERLY. IT IS POSSIBLE GRANT COUNTY STAYS CLOUDY ALL DAY
MONDAY WITH 925MB WINDS STILL FORECAST NEAR CALM OR OUT OF THE
NORTHEAST...SOMETHING THAT WILL HAVE TO BE MONITORED. OTHERWISE...
SHOULD GET A BAND OF MID/HIGH CLOUDS TO COME ACROSS MONDAY NIGHT
INTO TUESDAY WITH THE BRITISH COLUMBIA UPPER TROUGH. MORE HIGH
CLOUDS LOOK TO MOVE THROUGH WEDNESDAY AFTERNOON AS THE UPPER RIDGE
AXIS CROSSES THE FORECAST AREA.

TEMPERATURES ARE ALSO TRICKY. RAISED LOW TEMPERATURES UP FOR MOST
AREAS TONIGHT INTO THE MID TO UPPER 20S...EXCEPT FOR THE FAR WEST
WHERE CLEARING AND LIGHTER WINDS SHOULD ALLOW TEMPS TO TANK INTO THE
UPPER TEENS TO AROUND 20. STILL SHOULD SEE A DECENT AMOUNT OF SUN ON
MONDAY TO ALLOW TEMPS TO CLIMB INTO THE MID 30S TO LOW 40S...AIDED
BY 850MB TEMPS REACHING 4-6C BY LATE AFTERNOON AHEAD OF THE UPPER
TROUGH. LOOK FOR A COOL DOWN ON TUESDAY AS THE UPPER TROUGH
CROSSES...DROPPING 850MB TEMPS DOWN TO -2 TO -4C AND THUS HIGHS INTO
THE LOW TO MID 30S. TUESDAY NIGHT COULD BE QUITE CHILLY WITH A
SURFACE RIDGE CROSSING AND CLEAR SKIES. STAYED WITH A BLEND OF
GUIDANCE THEN. MODERATION IN TEMPERATURES IS EXPECTED AGAIN ON
WEDNESDAY WITH THE UPPER RIDGE COMING IN...BRINGING 850MB TEMPS UP
TO 1-3C.

.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
255 PM CST SUN NOV 27 2011

SIMILAR TO YESTERDAY...MODELS AND GFS ENSEMBLES ARE IN PRETTY GOOD
AGREEMENT THROUGH FRIDAY ON THE UPPER AIR PATTERN...THEN BEGIN TO
DIVERGE ON HOW TO HANDLE THE WEEKEND. FIRST FEATURE OF INTEREST IS A
LONG WAVE TROUGH EXTENDING FROM SASKATCHEWAN INTO CALIFORNIA AT 00Z
THURSDAY. MODELS PROG THIS TROUGH TO SPLIT INTO TWO...WITH THE
NORTHERN PORTION CROSSING THE FORECAST AREA THURSDAY NIGHT. AHEAD OF
THE TROUGH...MODELS HAVE BECOME IN BETTER AGREEMENT ALL SHOWING SOME
LIGHT SNOW COMING THROUGH...THOUGH FOR THE 27.12Z ECMWF IT IS A
CHANGE FROM ITS PREVIOUS RUN WHICH HAD NO SNOW DUE TO DRY LOW
LEVELS. THEREFORE...ONLY HAVE 20 PERCENT CHANCES OF SNOW AT THE
MOMENT. LATER FORECASTS MAY NEED HIGHER CHANCES IF MODELS STAY IN
AGREEMENT. DRY AND COLDER CONDITIONS LOOK ON TAP FOR THURSDAY NIGHT
INTO FRIDAY AS 850MB TEMPS DROP TO -8 TO -10C AND SURFACE HIGH
PRESSURE BUILDS IN. THE WEEKEND FEATURES ISSUES REGARDING HANDLING
SHORTWAVES DROPPING DOWN OFF A BUILDING EASTERN PACIFIC RIDGE...AND
IF THESE SHORTWAVES CAN POSSIBLY PHASE WITH THE SOUTHERN END OF THE
LONG WAVE TROUGH THAT GOT CUT-OFF ON THURSDAY. THE 27.12Z GFS AND
SOME OF ITS ENSEMBLES SAY THE CUT-OFF LOW REMAINS...RESULTING IN A
DRY NORTHWEST FLOW PATTERN FOR THE WEEKEND. THE 27.12Z ECMWF AND
EXTRAPOLATION OF THE 27.12Z UKMET/CANADIAN SUGGEST A PHASING OR AT
LEAST THE UPPER LOW GETTING KICKED NORTHEAST TOWARDS THE FORECAST
AREA. HARD TO SAY WHICH ONE IS RIGHT AT THIS MOMENT...BUT SINCE
VERIFICATION WISE THE ECMWF TENDS TO A LITTLE BETTER AND DOES HAVE
SOME CONSISTENCY FROM ITS PREVIOUS RUN...TEND TO LEAN MORE TOWARDS
THE ECMWF/UKMET/CANADIAN CAMP. UNDER THIS SCENARIO...SATURDAY SHOULD
STILL END UP DRY WITH MODERATION AS RETURN FLOW SETS UP BEHIND
FRIDAYS SURFACE RIDGE. ISENTROPIC LIFT/WARM ADVECTION THEN SET UP
FOR SATURDAY NIGHT ACROSS FAR SOUTHERN AREAS OF THE CWA...AND ACROSS
THE REST OF THE FORECAST AREA ON SUNDAY AS THE UPPER LOW APPROACHES.
PLACED IN 20 PERCENT CHANCES AT THE PRESENT TIME...GIVEN THE
UNCERTAINTY PRESENT WITH THE GFS SCENARIO AND SOME OF THE GFS
ENSEMBLES.

&&

.AVIATION...THIS AFTERNOON THROUGH MONDAY
1130 AM CST SUN NOV 27 2011

MN/IA/WI REMAIN FIRMLY UNDER MVFR STATUS DECK AS OF MID-DAY.
CLOUDS/MOISTURE ARE TRAPPED UNDER/IN AN INVERSION IN THE 900-850MB
LAYER AND ARE 1500-2000FT DEEP...MAKING THE CLOUD DECK RATHER
RESISTANT TO EROSION/MIXING IN PLACE. DISTANCE-SPEED TOOL APPLIED
TO THE WESTERN EDGE OF THE CLOUDS HAS THE CLEARING LINE MOVING
15018KT. THIS TIMING WOULD PUT THE CLEARING TO KRST AROUND 14Z MON
AND KLSE AROUND 18Z MON. SFC RIDGE AXIS MOVES OVER THE FCST AREA
TONIGHT...WITH WINDS ACROSS CENTRAL/NORTHERN MN/NORTHWEST WI
BECOMING SOUTHWEST/WEST LATE TONIGHT AND FOR MON. THIS MAY
ACCELERATE THE CLOUDS/CLEARING EASTWARD...BUT THIS INCREASE OF
SOUTHWEST FLOW DOES NOT SPREAD OVER THE TAF SITES UNTIL MON MORNING.
HAVE USED THE DISTANCE-SPEED TOOL TIMING OF CLEARING THE MVFR STATUS
OUT OF THE TAFS SITES. SFC PRESSURE GRADIENT CONTINUES TO RELAX THIS
AFTERNOON/EVENING WITH RESULTING GRADUAL DECREASE OF SFC WINDS.
ONCE THE CLOUDS CLEAR THE TAF SITES MON...AN EXTENDED PERIOD OF VFR
CONDITIONS EXPECTED MUCH OF THE UPCOMING WORK WEEK.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
255 PM CST SUN NOV 27 2011

WI...NONE.
MN...NONE.
IA...NONE.

&&

$$

SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RRS








AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 1130 AM CST SUN NOV 27 2011

.SHORT TERM...TODAY THROUGH WEDNESDAY
1030 AM CST SUN NOV 27 2011

IN THE PROCESS OF ISSUING AN UPDATE TO LINGER THE STRATUS DECK THRU
TONIGHT AND INTO MONDAY OVER MUCH OF THE FCST AREA.

STRATUS EXTENDS ALL THE WAY UP INTO CAN EAST OF LK WINNIPEG.
DISTANCE-SPEED TOOL APPLIED TO WEST EDGE OF THE STRATUS FOR THE PAST
20 HRS HAS IT MOVING 150 DEGREES AT 18KTS. MOISTURE IS 1500-2000 FT
DEEP OVER CENTRAL/EASTERN MN PER LAPS SOUNDINGS AND PILOT REPORTS.
MODEL SOUNDINGS SHOW THE MOISTURE UNDER THE 900-850MB INVERSION AS
WELL AS IN THE STABLE INVERSION LAYER. THIS PLUS THE INVERSION AND
DEPTH OF MOISTURE WILL MAKE THE CLOUDS VERY DIFFICULT TO ERODE/MIX
OUT. IT LOOKING LIKE WE WILL HAVE TO WAIT FOR THE CLOUDS TO ADVECT
OUT OF THE AREA TONIGHT/MON. BASED ON SATELLITE TRENDS WITH THE
DISTANCE-SPEED TOOL AND RUC LOW LEVEL MOISTURE FIELDS...CLEARING
EDGE OF THE CLOUDS DOES NOT REACH THE WEST EDGE OF THE FCST AREA
UNTIL 11Z MON. BULK OF OTHER MODELS MIX/ERODE THE TRAPPED LOW LEVEL
MOISTURE OUT OF MN/IA/WESTERN WI RATHER QUICKLY THIS
AFTERNOON/EVENING WHICH APPEARS VERY OPTIMISTIC. WINDS ACROSS
CENTRAL/NORTHERN MN DO BECOME SOUTHWEST LATE TONIGHT...WITH SOME
ACCELERATION OF THE EAST MOVEMENT OF THE CLOUDS EXPECTED NORTH OF
THE FCST AREA LATE TONIGHT AND ON MON. LAST TO SEE THE CLOUDS CLEAR
MON LOOKING TO BE THE SOUTHEAST END OF THE FCST AREA. THUS HAVE
UPDATED FCST GRIDS FOR MORE CLOUDS TONIGHT INTO MON. HAVE ALSO
RAISED LOWS TONIGHT WHERE SKIES EXPECTED TO REMAIN OVERCAST. HOWEVER
CONCERNED THAT MAY NOT HAVE RAISED THESE ENOUGH OVER THE SOUTHEAST
HALF OF THE FCST AREA WHERE CONFIDENCE IS PRETTY HIGH FOR CLOUDY
SKIES THRU THE NIGHT AND TO 15Z MON.

.LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY NIGHT
236 AM CST SUN NOV 27 2011

FAIRLY QUIET EXTENDED PERIOD WITH TWO SYSTEMS OF NOTE TO KEEP AN
EYE ON. SOME UNCERTAINTY EXISTS WITH A COLD FRONT THAT DROPS DOWN
THROUGH THE REGION ON THURSDAY WITH SOME OF THE PREVIOUS MODELS
SUGGESTING THAT SOME POST-FRONTAL SNOW COULD FORM. THE LATEST
TREND IS TO GO AWAY FROM THIS THOUGH WITH DRIER AIR IN LOW LEVELS
RESTRICTING ANY PRECIPITATION FROM MAKING IT TO THE GROUND. THE
NEXT CHANCES FOR ANY PRECIPITATION WILL BE ON SATURDAY NIGHT AS
ANOTHER COLD FRONT DROPS DOWN INTO THE REGION.

&&

.AVIATION...THIS AFTERNOON THROUGH MONDAY
1130 AM CST SUN NOV 27 2011

MN/IA/WI REMAIN FIRMLY UNDER MVFR STATUS DECK AS OF MID-DAY.
CLOUDS/MOISTURE ARE TRAPPED UNDER/IN AN INVERSION IN THE 900-850MB
LAYER AND ARE 1500-2000FT DEEP...MAKING THE CLOUD DECK RATHER
RESISTANT TO EROSION/MIXING IN PLACE. DISTANCE-SPEED TOOL APPLIED
TO THE WESTERN EDGE OF THE CLOUDS HAS THE CLEARING LINE MOVING
15018KT. THIS TIMING WOULD PUT THE CLEARING TO KRST AROUND 14Z MON
AND KLSE AROUND 18Z MON. SFC RIDGE AXIS MOVES OVER THE FCST AREA
TONIGHT...WITH WINDS ACROSS CENTRAL/NORTHERN MN/NORTHWEST WI
BECOMING SOUTHWEST/WEST LATE TONIGHT AND FOR MON. THIS MAY
ACCELERATE THE CLOUDS/CLEARING EASTWARD...BUT THIS INCREASE OF
SOUTHWEST FLOW DOES NOT SPREAD OVER THE TAF SITES UNTIL MON MORNING.
HAVE USED THE DISTANCE-SPEED TOOL TIMING OF CLEARING THE MVFR STATUS
OUT OF THE TAFS SITES. SFC PRESSURE GRADIENT CONTINUES TO RELAX THIS
AFTERNOON/EVENING WITH RESULTING GRADUAL DECREASE OF SFC WINDS.
ONCE THE CLOUDS CLEAR THE TAF SITES MON...AN EXTENDED PERIOD OF VFR
CONDITIONS EXPECTED MUCH OF THE UPCOMING WORK WEEK.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
236 AM CST SUN NOV 27 2011

WI...NONE.
MN...NONE.
IA...NONE.

&&

$$

SHORT TERM...RRS/AJ
LONG TERM....HALBACH
AVIATION.....RRS








AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 1030 AM CST SUN NOV 27 2011

.SHORT TERM...TODAY THROUGH WEDNESDAY
1030 AM CST SUN NOV 27 2011

IN THE PROCESS OF ISSUING AN UPDATE TO LINGER THE STRATUS DECK THRU
TONIGHT AND INTO MONDAY OVER MUCH OF THE FCST AREA.

STRATUS EXTENDS ALL THE WAY UP INTO CAN EAST OF LK WINNIPEG.
DISTANCE-SPEED TOOL APPLIED TO WEST EDGE OF THE STRATUS FOR THE PAST
20 HRS HAS IT MOVING 150 DEGREES AT 18KTS. MOISTURE IS 1500-2000 FT
DEEP OVER CENTRAL/EASTERN MN PER LAPS SOUNDINGS AND PILOT REPORTS.
MODEL SOUNDINGS SHOW THE MOISTURE UNDER THE 900-850MB INVERSION AS
WELL AS IN THE STABLE INVERSION LAYER. THIS PLUS THE INVERSION AND
DEPTH OF MOISTURE WILL MAKE THE CLOUDS VERY DIFFICULT TO ERODE/MIX
OUT. IT LOOKING LIKE WE WILL HAVE TO WAIT FOR THE CLOUDS TO ADVECT
OUT OF THE AREA TONIGHT/MON. BASED ON SATELLITE TRENDS WITH THE
DISTANCE-SPEED TOOL AND RUC LOW LEVEL MOISTURE FIELDS...CLEARING
EDGE OF THE CLOUDS DOES NOT REACH THE WEST EDGE OF THE FCST AREA
UNTIL 11Z MON. BULK OF OTHER MODELS MIX/ERODE THE TRAPPED LOW LEVEL
MOISTURE OUT OF MN/IA/WESTERN WI RATHER QUICKLY THIS
AFTERNOON/EVENING WHICH APPEARS VERY OPTIMISTIC. WINDS ACROSS
CENTRAL/NORTHERN MN DO BECOME SOUTHWEST LATE TONIGHT...WITH SOME
ACCELERATION OF THE EAST MOVEMENT OF THE CLOUDS EXPECTED NORTH OF
THE FCST AREA LATE TONIGHT AND ON MON. LAST TO SEE THE CLOUDS CLEAR
MON LOOKING TO BE THE SOUTHEAST END OF THE FCST AREA. THUS HAVE
UPDATED FCST GRIDS FOR MORE CLOUDS TONIGHT INTO MON. HAVE ALSO
RAISED LOWS TONIGHT WHERE SKIES EXPECTED TO REMAIN OVERCAST. HOWEVER
CONCERNED THAT MAY NOT HAVE RAISED THESE ENOUGH OVER THE SOUTHEAST
HALF OF THE FCST AREA WHERE CONFIDENCE IS PRETTY HIGH FOR CLOUDY
SKIES THRU THE NIGHT AND TO 15Z MON.

.LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY NIGHT
236 AM CST SUN NOV 27 2011

FAIRLY QUIET EXTENDED PERIOD WITH TWO SYSTEMS OF NOTE TO KEEP AN
EYE ON. SOME UNCERTAINTY EXISTS WITH A COLD FRONT THAT DROPS DOWN
THROUGH THE REGION ON THURSDAY WITH SOME OF THE PREVIOUS MODELS
SUGGESTING THAT SOME POST-FRONTAL SNOW COULD FORM. THE LATEST
TREND IS TO GO AWAY FROM THIS THOUGH WITH DRIER AIR IN LOW LEVELS
RESTRICTING ANY PRECIPITATION FROM MAKING IT TO THE GROUND. THE
NEXT CHANCES FOR ANY PRECIPITATION WILL BE ON SATURDAY NIGHT AS
ANOTHER COLD FRONT DROPS DOWN INTO THE REGION.

&&

.AVIATION...THROUGH 12Z MONDAY
552 AM CST SUN NOV 27 2011

MORNING IR SATELLITE IMAGERY/SURFACE OBSERVATIONS SHOWING WIDESPREAD
MVFR STRATUS ENTRENCHED ACROSS THE UPPER MISSISSIPPI RIVER VALLEY
REGION INCLUDING KRST/KLSE TAF SITES. IN ADDITION...A FAIRLY TIGHT
PRESSURE GRADIENT WAS PRODUCING NORTHWEST WINDS IN THE 15 TO 25 KT
RANGE ACROSS THE AREA. MAIN CONCERN CONTINUES TO BE ON HOW LONG THE
STRATUS LINGERS AS HIGH PRESSURE BUILDS IN FROM THE PLAINS. LATEST
RUC MODELS SOUNDING/BUFKIT SHOWS MOISTURE/STRATUS REMAINING TRAPPED
BELOW THE SUBSIDENCE INVERSION ASSOCIATED WITH THE HIGH THROUGH
TODAY AND INTO THIS EVENING. TRENDED MORE ON THE PESSIMISTIC SIDE...
KEEPING THE BKN-OVC MVFR STRATUS IN AT KRST THROUGH 01Z...THEN
SCATTERING OUT AFTERWARDS AS THE RIDGE AXIS MOVES OVERHEAD. AT
KLSE...THINKING THAT STRATUS SHOULD BREAK UP SOMETIME AROUND 06Z.
WINDS SHOULD SUBSIDE THROUGH THIS AFTERNOON AS THE PRESSURE GRADIENT
RELAXES A BIT...THEN GOING LIGHT LESS THAN 5KT BY 03Z.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
236 AM CST SUN NOV 27 2011

WI...NONE.
MN...NONE.
IA...NONE.

&&

$$

SHORT TERM...RRS/AJ
LONG TERM....HALBACH
AVIATION.....DAS





AREA FORECAST DISCUSSION ...CORRECTION FOR AVIATION VALID TIME

NWS LA CROSSE WI

 552 AM CST SUN NOV 27 2011

.SHORT TERM...TODAY THROUGH WEDNESDAY
236 AM CST SUN NOV 27 2011

THE MAIN FOCUS OF THE NEAR TERM IS WITH WHEN THE STRATUS WILL
CLEAR ALONG WITH WHETHER SOME SCATTERED FLURRIES WILL LINGER THIS
MORNING BEFORE DRY CONDITIONS TAKE OVER FOR THE REST OF THE WEEK.

AN ELONGATED MID TO UPPER LEVEL TROUGH THAT EXTENDS FROM WESTERN
ONTARIO SOUTH THROUGH MINNESOTA TO TEXAS CONTINUES TO SLOWLY
PROPAGATE EASTWARD THIS MORNING. THE 500-300MB PV ADVECTION IS
JUST STRONG ENOUGH TO PROVIDE SOME LIFT TO PRODUCE SOME SCATTERED
SNOW FLURRIES ACROSS PARTS OF THE REGION. THERMAL PROFILES FROM
THE 27.05Z RUC AND THE LATEST IR SATELLITE TEMPERATURE SCANS SHOW
THAT THE STRATUS DECK IS IN THE -10 TO -12C RANGE...WHICH WOULD BE
CONDUCIVE TO ICE DEVELOPMENT IN THE CLOUD. THUS...SCATTERED
FLURRIES WILL BE POSSIBLE THROUGH LATE MORNING WHEN THE MID LEVEL
TROUGH AND PV ADVECTION MOVES INTO CENTRAL TO EASTERN WISCONSIN.

EVEN THOUGH THE FLURRIES APPEAR THAT THEY SHOULD COME TO AN END
LATER THIS MORNING...THE STRATUS DECK IS ANOTHER STORY.
CURRENTLY THIS DECK EXTENDS WEST THROUGH MINNESOTA INTO THE EASTERN
PARTS OF NORTH AND SOUTH DAKOTA WITH NO BREAKS EVIDENT WITH IT.
THE 27.00Z NAM AND GFS APPEAR TO BE TOO AGGRESSIVE WITH CLEARING
THESE CLOUDS OUT THIS MORNING WHILE THE 27.05Z RUC ALONG WITH PREVIOUS
RUNS SEEM TO HAVE A BETTER GRIP ON REALITY AND KEEPS THE HIGHER RH
VALUES AROUND UNDER THE 850MB INVERSION INTO EVENING. THE BACK
EDGE OF THE STRATUS APPEARS TO BE LOOSELY TIED TO BEING JUST AHEAD
OF THE MAIN SURFACE TO 925MB RIDGE AXIS...WHICH DOES NOT GET INTO
THE REGION UNTIL TONIGHT. THUS...HAVE GONE WITH A MORE PESSIMISTIC
CLOUD FORECAST FOR TODAY WITH AN EVENTUAL CLEARING TONIGHT AS THE
RIDGE MOVES IN.

AFTER THE RIDGE MOVES THROUGH...LOW LEVEL WINDS WILL SWING AROUND
TO THE SOUTHWEST AHEAD OF THE NEXT DISTURBANCE DROPPING OUT OF
SOUTHERN CANADA. MID LEVEL QG FORCING AND LOW LEVEL FRONTOGENESIS
WEAKENS QUITE A BIT AS THE COLD FRONT DROPS DOWN INTO THE REGION.
MOISTURE DOES REACH SATURATION IN THE MID TO HIGH LEVELS MONDAY
NIGHT INTO TUESDAY MORNING BASED ON 27.00Z NAM AND GFS FORECAST
SOUNDINGS AND RH FIELDS...SO THERE SHOULD BE AN INCREASE IN CLOUD
COVER OVER THIS TIME FRAME. THE LOW LEVEL MOISTURE FEED APPEARS TO
BE TAKEN OVER BY THE CUT OFF LOW IN THE OHIO RIVER VALLEY.
THUS...ANY PRECIPITATION OUT OF THIS SYSTEM LOOKS UNLIKELY AS THIS
FRONT PASSES THROUGH. ANOTHER RIDGE OF HIGH PRESSURE WILL MOVE
INTO THE REGION BEHIND THIS FRONT AS THE CUT OFF LOW TO THE EAST
TRACKS THROUGH THE EASTERN GREAT LAKES REGION.

.LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY NIGHT
236 AM CST SUN NOV 27 2011

FAIRLY QUIET EXTENDED PERIOD WITH TWO SYSTEMS OF NOTE TO KEEP AN
EYE ON. SOME UNCERTAINTY EXISTS WITH A COLD FRONT THAT DROPS DOWN
THROUGH THE REGION ON THURSDAY WITH SOME OF THE PREVIOUS MODELS
SUGGESTING THAT SOME POST-FRONTAL SNOW COULD FORM. THE LATEST
TREND IS TO GO AWAY FROM THIS THOUGH WITH DRIER AIR IN LOW LEVELS
RESTRICTING ANY PRECIPITATION FROM MAKING IT TO THE GROUND. THE
NEXT CHANCES FOR ANY PRECIPITATION WILL BE ON SATURDAY NIGHT AS
ANOTHER COLD FRONT DROPS DOWN INTO THE REGION.

&&

.AVIATION...THROUGH 12Z MONDAY
552 AM CST SUN NOV 27 2011

MORNING IR SATELLITE IMAGERY/SURFACE OBSERVATIONS SHOWING WIDESPREAD
MVFR STRATUS ENTRENCHED ACROSS THE UPPER MISSISSIPPI RIVER VALLEY
REGION INCLUDING KRST/KLSE TAF SITES. IN ADDITION...A FAIRLY TIGHT
PRESSURE GRADIENT WAS PRODUCING NORTHWEST WINDS IN THE 15 TO 25 KT
RANGE ACROSS THE AREA. MAIN CONCERN CONTINUES TO BE ON HOW LONG THE
STRATUS LINGERS AS HIGH PRESSURE BUILDS IN FROM THE PLAINS. LATEST
RUC MODELS SOUNDING/BUFKIT SHOWS MOISTURE/STRATUS REMAINING TRAPPED
BELOW THE SUBSIDENCE INVERSION ASSOCIATED WITH THE HIGH THROUGH
TODAY AND INTO THIS EVENING. TRENDED MORE ON THE PESSIMISTIC SIDE...
KEEPING THE BKN-OVC MVFR STRATUS IN AT KRST THROUGH 01Z...THEN
SCATTERING OUT AFTERWARDS AS THE RIDGE AXIS MOVES OVERHEAD. AT
KLSE...THINKING THAT STRATUS SHOULD BREAK UP SOMETIME AROUND 06Z.
WINDS SHOULD SUBSIDE THROUGH THIS AFTERNOON AS THE PRESSURE GRADIENT
RELAXES A BIT...THEN GOING LIGHT LESS THAN 5KT BY 03Z.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
236 AM CST SUN NOV 27 2011

WI...NONE.
MN...NONE.
IA...NONE.

&&

$$

SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...DAS













AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 236 AM CST SUN NOV 27 2011

.SHORT TERM...TODAY THROUGH WEDNESDAY
236 AM CST SUN NOV 27 2011

THE MAIN FOCUS OF THE NEAR TERM IS WITH WHEN THE STRATUS WILL
CLEAR ALONG WITH WHETHER SOME SCATTERED FLURRIES WILL LINGER THIS
MORNING BEFORE DRY CONDITIONS TAKE OVER FOR THE REST OF THE WEEK.

AN ELONGATED MID TO UPPER LEVEL TROUGH THAT EXTENDS FROM WESTERN
ONTARIO SOUTH THROUGH MINNESOTA TO TEXAS CONTINUES TO SLOWLY
PROPAGATE EASTWARD THIS MORNING. THE 500-300MB PV ADVECTION IS
JUST STRONG ENOUGH TO PROVIDE SOME LIFT TO PRODUCE SOME SCATTERED
SNOW FLURRIES ACROSS PARTS OF THE REGION. THERMAL PROFILES FROM
THE 27.05Z RUC AND THE LATEST IR SATELLITE TEMPERATURE SCANS SHOW
THAT THE STRATUS DECK IS IN THE -10 TO -12C RANGE...WHICH WOULD BE
CONDUCIVE TO ICE DEVELOPMENT IN THE CLOUD. THUS...SCATTERED
FLURRIES WILL BE POSSIBLE THROUGH LATE MORNING WHEN THE MID LEVEL
TROUGH AND PV ADVECTION MOVES INTO CENTRAL TO EASTERN WISCONSIN.

EVEN THOUGH THE FLURRIES APPEAR THAT THEY SHOULD COME TO AN END
LATER THIS MORNING...THE STRATUS DECK IS ANOTHER STORY.
CURRENTLY THIS DECK EXTENDS WEST THROUGH MINNESOTA INTO THE EASTERN
PARTS OF NORTH AND SOUTH DAKOTA WITH NO BREAKS EVIDENT WITH IT.
THE 27.00Z NAM AND GFS APPEAR TO BE TOO AGGRESSIVE WITH CLEARING
THESE CLOUDS OUT THIS MORNING WHILE THE 27.05Z RUC ALONG WITH PREVIOUS
RUNS SEEM TO HAVE A BETTER GRIP ON REALITY AND KEEPS THE HIGHER RH
VALUES AROUND UNDER THE 850MB INVERSION INTO EVENING. THE BACK
EDGE OF THE STRATUS APPEARS TO BE LOOSELY TIED TO BEING JUST AHEAD
OF THE MAIN SURFACE TO 925MB RIDGE AXIS...WHICH DOES NOT GET INTO
THE REGION UNTIL TONIGHT. THUS...HAVE GONE WITH A MORE PESSIMISTIC
CLOUD FORECAST FOR TODAY WITH AN EVENTUAL CLEARING TONIGHT AS THE
RIDGE MOVES IN.

AFTER THE RIDGE MOVES THROUGH...LOW LEVEL WINDS WILL SWING AROUND
TO THE SOUTHWEST AHEAD OF THE NEXT DISTURBANCE DROPPING OUT OF
SOUTHERN CANADA. MID LEVEL QG FORCING AND LOW LEVEL FRONTOGENESIS
WEAKENS QUITE A BIT AS THE COLD FRONT DROPS DOWN INTO THE REGION.
MOISTURE DOES REACH SATURATION IN THE MID TO HIGH LEVELS MONDAY
NIGHT INTO TUESDAY MORNING BASED ON 27.00Z NAM AND GFS FORECAST
SOUNDINGS AND RH FIELDS...SO THERE SHOULD BE AN INCREASE IN CLOUD
COVER OVER THIS TIME FRAME. THE LOW LEVEL MOISTURE FEED APPEARS TO
BE TAKEN OVER BY THE CUT OFF LOW IN THE OHIO RIVER VALLEY.
THUS...ANY PRECIPITATION OUT OF THIS SYSTEM LOOKS UNLIKELY AS THIS
FRONT PASSES THROUGH. ANOTHER RIDGE OF HIGH PRESSURE WILL MOVE
INTO THE REGION BEHIND THIS FRONT AS THE CUT OFF LOW TO THE EAST
TRACKS THROUGH THE EASTERN GREAT LAKES REGION.

.LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY NIGHT
236 AM CST SUN NOV 27 2011

FAIRLY QUIET EXTENDED PERIOD WITH TWO SYSTEMS OF NOTE TO KEEP AN
EYE ON. SOME UNCERTAINTY EXISTS WITH A COLD FRONT THAT DROPS DOWN
THROUGH THE REGION ON THURSDAY WITH SOME OF THE PREVIOUS MODELS
SUGGESTING THAT SOME POST-FRONTAL SNOW COULD FORM. THE LATEST
TREND IS TO GO AWAY FROM THIS THOUGH WITH DRIER AIR IN LOW LEVELS
RESTRICTING ANY PRECIPITATION FROM MAKING IT TO THE GROUND. THE
NEXT CHANCES FOR ANY PRECIPITATION WILL BE ON SATURDAY NIGHT AS
ANOTHER COLD FRONT DROPS DOWN INTO THE REGION.

&&

.AVIATION...THROUGH 06Z MONDAY
1135 PM CST SAT NOV 26 2011

MAIN CONCERN IS ON HOW QUICKLY STRATUS DEPARTS THE AREA SUNDAY. AT 05Z
INFRARED SATELLITE IMAGERY SHOWING LARGE STRATUS DECK IN THE WAKE
OF THE COLD FRONT. BACK EDGE WAS OVER THE EASTERN DAKOTAS AND HAS
SHOWN NO EASTWARD MOVEMENT THROUGH THE EVENING HOURS. 27.00Z NAM
MOST ROBUST IN WANTING TO PUSH THE STRATUS OUT ON SUNDAY MORNING. HOWEVER
BASED ON CURRENT SATELLITE TRENDS THIS APPEARS TO BE TOO FAST.
27.02Z RUC BUFKIT SOUNDING HOLDS ONTO THE LOW LEVEL MOISTURE BELOW
THE INVERSION UNTIL AT LEAST 21Z AT KLSE AND KRST. WILL TREND
TOWARDS THE SLOWER SOLUTION...WITH CEILINGS SCATTERING OUT AT 01Z
AT KLSE AND 23Z AT KRST. UNTIL THEN EXPECT CEILINGS IN THE
015-025K FOOT RANGE AT BOTH SITES. PRESSURE GRADIENT REMAINS TIGHT
AND THUS EXPECT SOME GUSTS TO CONTINUE THROUGH 18Z...AFTER WHICH
THE GRADIENT DOES RELAX SOMEWHAT. ONCE CLOUDS SCATTER OUT...EXPECT
LIGHTER WINDS AND VFR CONDITIONS AFTER 01Z MONDAY.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
236 AM CST SUN NOV 27 2011

WI...NONE.
MN...NONE.
IA...NONE.

&&

$$

SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...RABERDING







AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 1135 PM CST SAT NOV 26 2011

.SHORT TERM...TONIGHT THROUGH TUESDAY
219 PM CST SAT NOV 26 2011

MAIN FORECAST CONCERNS ARE WITH PRECIPITATION TONIGHT AND THEN
TEMPERATURES THROUGH THE REST OF THE SHORT TERM PERIOD.

CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGES OVER BOTH THE WEST AND EAST COASTS OF THE U.S. AND
TROUGHING IN-BETWEEN FROM MANITOBA SOUTHWARD THROUGH TEXAS. BULK OF
THE ENERGY ASSOCIATED WITH THE UPPER TROUGHING HAS BEEN DROPPING
SOUTH INTO TEXAS PER PRESSURE VALUES ON THE 1.5 PV SURFACE. STILL...
GRADUAL HEIGHT FALLS ON THE EAST SIDE OF THE UPPER TROUGH AND
SHORTWAVES MOVING THROUGH THE SOUTHWEST FLOW...COMBINED WITH LOW
LEVEL MOISTURE TRANSPORT...HELPED BRING THE LIGHT TO MODERATE RAIN
TO MUCH OF THE FORECAST AREA THIS MORNING. THIS PRECIPITATION IS
NOW ONLY AFFECTING THE FAR SOUTHEASTERN PORTION OF THE FORECAST
AREA DUE TO A DRY SLOT IN THE MID TO UPPER LEVELS PUNCHING IN
ELSEWHERE. MEANWHILE...VERY WEAK COLD CONVEYOR BELT AROUND A
1006MB SURFACE LOW IN NORTHEAST WISCONSIN IS REFLECTED BY LIGHT
RADAR RETURNS ACROSS CENTRAL MN INTO NORTHWEST WI. A MIX OF LIGHT
RAIN AND SNOW HAS BEEN REPORTED WITH THESE RADAR RETURNS...THANKS
TO SURFACE TEMPERATURES THAT HAVE BEEN FALLING ON GUSTY NORTHWEST
WINDS. OFF TO THE WEST... EVEN COLDER AIR WAS EVIDENT OVER THE
DAKOTAS INTO MONTANA WHERE 12Z 850MB TEMPS WERE OBSERVED AT -5 TO
-7C. COMPARE THIS TO OBSERVED 4-6C OVER THE AREA AT 12Z TODAY.
SKIES DO CLEAR OUT OVER THE WESTERN DAKOTAS...THOUGH...THANKS TO A
DRY 12Z GLASGOW MT SOUNDING.

TONIGHT AND SUNDAY...UPPER TROUGH OVER THE PLAINS IS FORECAST TO
GRADUALLY TRACK EAST DURING THIS PERIOD...WITH THE 500MB AXIS
SITUATED OVER LA CROSSE AT 12Z SUNDAY AND THEN OVER EASTERN
WISCONSIN AT 00Z MONDAY. SINCE THIS UPPER TROUGH IS COMING THROUGH
POSITIVELY TILTED AND AGAIN MOST OF THE ENERGY DROPPING SOUTH INTO
THE SOUTHERN PLAINS...VERY LITTLE IN THE WAY OF FORCING IS EXPECTED.
MAIN PRECIPITATION LOOKS TO BE THE CURRENT WEAK COLD CONVEYOR BELT
OVER CENTRAL MINNESOTA WHICH SHOULD SLIDE THROUGH MUCH OF THE
FORECAST AREA THIS EVENING. CANNOT RULE OUT A FEW HUNDREDTHS OF
QPF...AS INDICATED BY THE 26.12Z NAM/26.00Z ECMWF...BUT THE
PROBABILITY SEEMS TOO LOW TO GO MORE THAN A 50 PERCENT CHANCE GIVEN
NEARLY DRY 26.09Z SREF MEAN/26.12Z GFS AND GIVEN WEAK APPEARANCE OF
CONVEYOR BELT ON RADAR. PRECIPITATION TYPE WILL BE DETERMINED BY THE
SURFACE TEMPERATURE GIVEN THE WARMEST LAYER AT THE SURFACE...MAKING
IT A RAIN/SNOW SCENARIO. HOWEVER...THERE ARE SOME HINTS OF LOSS OF
ICE DUE TO SOME DRIER AIR IN THE 10000-15000 FT LAYER...WHICH COULD
ALLOW FOR JUST A LITTLE MORE LIQUID VS SNOW. NOT ENOUGH CONFIDENCE
EXISTS TO MENTION ANY FREEZING PRECIPITATION...THOUGH...DUE TO
QUESTION MARKS ON AMOUNT OF PRECIPITATION IN GENERAL AND SURFACE
TEMPERATURES LIKELY TAKING AWHILE TO FALL BELOW FREEZING. ANY
SNOW ACCUMULATION LIKELY TO BE VERY LIGHT IF AT ALL TOO. OVERNIGHT
HOURS THROUGH SUNDAY LOOK MOSTLY DRY AS THE UPPER TROUGH PUSHES
EAST AND SUBSIDENCE COMES IN. CERTAINLY MUCH COOLER WEATHER DURING
THIS PERIOD AS 850MB TEMPS TANK TO -4 TO -8C BY 12Z SUNDAY...ALONG
WITH THE BLUSTERY NORTHWEST WINDS. NOT A WHOLE LOT OF MODIFICATION
EXPECTED TOMORROW WITH CLEARING NOT COMING IN UNTIL LATE AND 850MB
TEMPS STAYING BELOW -2C. IN FACT...ANY CLEARING MAY ONLY OCCUR IN
THE FAR WESTERN FORECAST AREA.

SUNDAY NIGHT THROUGH TUESDAY...QUIET WEATHER LOOKS TO DOMINATE THE
FORECAST AREA DESPITE A FRONTAL PASSAGE LIKELY TO MOVE THROUGH VERY
LATE MONDAY. THINGS WILL BE MORE ACTIVE TO OUR SOUTHEAST AS AN UPPER
LOW FORMS OVER THE SOUTHEASTERN U.S....BUT ANY PRECIPITATION
WRAPPING BACK AROUND THIS UPPER LOW LOOKS TO STAY EAST AND SOUTH OF
CHICAGO. REGARDING THE FRONTAL PASSAGE...A NORTHERN STREAM UPPER
LEVEL TROUGH CURRENTLY OVER THE EASTERN PACIFIC IS FORECAST TO CROSS
THE DAKOTAS ON MONDAY...BRINGING A SURGE OF DOWNSLOPED WARMED AIR
INTO THE FORECAST AREA. 850MB TEMPS ACTUALLY CLIMB UP TO 4-6C BY 00Z
TUESDAY. PROBLEM IS THAT A LOT OF THE WARMING TAKES PLACE ALOFT AND
WE WILL NOT BE ABLE TO MIX UP TO IT...DUE TO THE LOW SUN ANGLE AND
LIGHT WINDS FORECAST. STILL...MIXING UP TO 925MB IS LIKELY WITH FULL
SUNSHINE RESULTING IN HIGHS IN THE UPPER 30S TO LOW 40S. THIS SHOULD
BE A NICE REBOUND AFTER SUNDAY NIGHT LOWS LIKELY IN THE MID TEENS TO
MID 20S...COLDEST IN THE TYPICAL COLD SPOTS. DRY WEATHER EXPECTED
WITH THE FRONTAL PASSAGE DUE TO LACK OF MOISTURE...THEN COOLER
TEMPERATURES COME IN AGAIN AS HIGH PRESSURE BUILDS BACK OVER THE
PLAINS FOR MONDAY NIGHT AND TUESDAY. 850MB TEMPS THIS TIME DO NOT
FALL AS MUCH...ONLY TO -2 TO -4C...SO TUESDAY SHOULD END UP A LITTLE
WARMER THAN SUNDAY. MAY HAVE SOME THICKER HIGH CLOUDS TO DEAL WITH
IN THE MORNING COMING OFF THE SOUTHEASTERN UPPER LOW TO LIMIT
FIXING...BUT THESE LOOK TO START CLEARING OUT IN THE AFTERNOON.

.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
219 PM CST SAT NOV 26 2011

SIMILAR TO THE SUNDAY NIGHT THROUGH TUESDAY TIME PERIOD...MUCH OF
THE EXTENDED LOOKS QUIET...THOUGH PLENTY OF UNCERTAINTY EXISTS WITH
THE UPPER LEVEL PATTERN HEADING INTO NEXT WEEKEND. LONGWAVE PATTERN
FEATURES UPPER RIDGING BUILDING INTO THE AREA ON WEDNESDAY BETWEEN
THE UPPER LOW LIFTING UP THE EAST COAST AND TROUGHING DIGGING DOWN
THE WEST COAST. SHOULD SEE WARMER TEMPERATURES ON WEDNESDAY
ASSOCIATED WITH THE UPPER RIDGING...THOUGH NOT MUCH ABOVE NORMAL
GIVEN 850MB TEMPS ONLY 2-4C. THIS TROUGHING LOOKS TO SPLIT INTO
TWO...WITH THE NORTHERN STREAM PORTION CROSSING THE FORECAST AREA
THURSDAY NIGHT. MODELS HAVE BEEN SPLIT WHETHER OR NOT FRONTOGENESIS
AND DPVA FORCING AHEAD OF THE NORTHERN STREAM TROUGH CAN PRODUCE
LIGHT SNOW...MOSTLY DUE TO LACK OF MOISTURE WITH IT. CONSENSUS OF
GUIDANCE SUGGESTS JUST A 10-15 PERCENT CHANCE FOR BOTH THURSDAY AND
THURSDAY NIGHT...WHICH RESULTS IN A DRY FORECAST. MORE IMPORTANTLY
IS THE 850MB TEMPS ACCOMPANYING THE TROUGH. MODELS HAVE BEEN
INCONSISTENT INCLUDING RUN TO RUN ON HOW COLD THE AIR IS WITH IT.
CURRENT CONSENSUS IS BETWEEN -8 TO -12C...BUT HAVE SEEN MODELS BOTH
WARMER AND COLDER. THIS SHOULD SET UP TEMPERATURES BELOW NORMAL FOR
FRIDAY AS AN AREA OF HIGH PRESSURE BUILDS IN. HEADING INTO THE
WEEKEND...MODELS ARE IN AGREEMENT OF RIDGING BUILDING UP IN THE
EASTERN PACIFIC. QUESTION IS WHERE SHORTWAVES DIG DOWN TO ON THE
EAST SIDE OF THIS RIDGE. THE 26.12Z GFS AND SOME GFS ENSEMBLE
MEMBERS ALLOW SHORTWAVES TO DIG DOWN INTO THE WESTERN U.S....
RESULTING IN DOWNSTREAM RIDGING OVER THE FORECAST AREA. OTHERS LIKE
THE 26.00Z/26.12Z ECMWF AND OTHER GFS ENSEMBLE MEMBERS DIG THE
SHORTWAVES DOWN MORE OVER THE NORTHERN PLAINS INTO OUR REGION BY
MAINTAINING NORTHWEST FLOW. FOLLOWED A SOMEWHAT OF CONSENSUS
APPROACH WHICH JUST PLACES SOME 10-20 PERCENT CHANCES OVER THE AREA
ON SATURDAY...MAINLY NORTH OF I-90 WITH A SHORTWAVE TROUGH GOING
THROUGH THERE. SLIGHTLY WARMER TEMPERATURES WOULD OCCUR ON SATURDAY
AS WELL WITH WARM ADVECTION ASSOCIATED WITH THE SHORTWAVE TROUGH.

IN SUMMARY...EXTENDED LOOKS AROUND NORMAL ON TEMPERATURES WITH
MAINLY DRY CONDITIONS.

&&

.AVIATION...THROUGH 06Z MONDAY
1135 PM CST SAT NOV 26 2011

MAIN CONCERN IS ON HOW QUICKLY STRATUS DEPARTS THE AREA SUNDAY. AT 05Z
INFRARED SATELLITE IMAGERY SHOWING LARGE STRATUS DECK IN THE WAKE
OF THE COLD FRONT. BACK EDGE WAS OVER THE EASTERN DAKOTAS AND HAS
SHOWN NO EASTWARD MOVEMENT THROUGH THE EVENING HOURS. 27.00Z NAM
MOST ROBUST IN WANTING TO PUSH THE STRATUS OUT ON SUNDAY MORNING. HOWEVER
BASED ON CURRENT SATELLITE TRENDS THIS APPEARS TO BE TOO FAST.
27.02Z RUC BUFKIT SOUNDING HOLDS ONTO THE LOW LEVEL MOISTURE BELOW
THE INVERSION UNTIL AT LEAST 21Z AT KLSE AND KRST. WILL TREND
TOWARDS THE SLOWER SOLUTION...WITH CEILINGS SCATTERING OUT AT 01Z
AT KLSE AND 23Z AT KRST. UNTIL THEN EXPECT CEILINGS IN THE
015-025K FOOT RANGE AT BOTH SITES. PRESSURE GRADIENT REMAINS TIGHT
AND THUS EXPECT SOME GUSTS TO CONTINUE THROUGH 18Z...AFTER WHICH
THE GRADIENT DOES RELAX SOMEWHAT. ONCE CLOUDS SCATTER OUT...EXPECT
LIGHTER WINDS AND VFR CONDITIONS AFTER 01Z MONDAY.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
219 PM CST SAT NOV 26 2011

WI...NONE.
MN...NONE.
IA...NONE.

&&

$$

SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING







AREA FORECAST DISCUSSION

NWS CHEYENNE WY

 430 PM MST MON NOV 28 2011

.AVIATION...00Z TAFS

COLD FRONT LOOKS TO BE THROUGH KCYS LATE THIS AFTERNOON WITH A
NORTH TO NORTHEAST WIND. CONCERN TURNS TO LOWERING CEILINGS
TONIGHT EAST OF THE LARAMIE RANGE. SOME FORECAST GUIDANCE SHOWING
CEILINGS DROPPING HERE AT KCYS TO IFR BY MORNING...BUT HRRR MODEL
NOT SHOWING THIS. ALSO LOW CLOUDS HAVE NOT YET DEVELOPED UPSTREAM
IN SOUTH DAKOTA OR NEBRASKA...SO CONFIDENCE IS NOT THERE FOR THIS
TO HAPPEN. DECIDED TO GO WITH MVFR CEILINGS AND CONTINUE TO
METWATCH UPSTREAM CLOUD FORMATION AND SEE WHAT HAPPENS BEFORE
GOING IFR IN ANY TAFS EAST OF THE LARAMIE RANGE.

CLAYCOMB


&&

.PREV DISCUSSION... /ISSUED 256 PM MST MON NOV 28 2011/

SHORT TERM...TONIGHT THROUGH WEDNESDAY...

CURRENTLY COLD FRONT ON THE DOORSTEP OF KCYS. WINDS HAVE SHIFTED
TO THE NORTHWEST AND ARE GUSTING INTO THE MID 30S BUT TEMPERATURE
REMAINING STEADY SO FAR. LOOKING AT PRESSURE CHANGE AND
OBSERVATIONS LOOKS LIKE THE FRONT HAS ALSO MOVED THROUGH THE
SOUTHERN PANHANDLE. RADAR REMAINED PPINE WITH THE FRONT AND
SATELLITE SHOWED MAINLY MID CLOUDS.

THIS MORNINGS UPPER PACKAGE PLENTY OF WARM AIR AHEAD OF THE SYSTEM
THAT IS MOVING THROUGH THE AREA. FLOW WAS GENERALLY FROM THE WEST
WITH LITTLE MOISTURE.

FORECAST PROBLEM FOR THIS PACKAGE WILL BE WINDS AND TEMPERATURES.

LOOKS LIKE HIGH PRESSURE WILL SETTLE ACROSS THE CWA TONIGHT BEHIND
THE FRONT AND GUSTY WINDS WILL PERSIST UNTIL AFTER SUNSET. TUESDAY
SHOULD BE DRY AND COOLER THAN TODAY BUT ANOTHER SYSTEM MOVING
MOVING INTO THE PACIFIC NORTHWEST WILL QUICKLY BRING THE WINDS
AROUND AND TEMPER SIGNIFICANT COOLING. THE NEXT SYSTEM WILL
CONTINUE TO APPROACH AND ON WEDNESDAY WILL SEE CLOUDS INCREASING.
BY WEDNESDAY AFTERNOON COULD POSSIBLY START TO SEE SOME
PRECIPITATION IN THE HIGH COUNTRY AND IN THE NORTHERN CWA BUT THE
SNOW SHOULD BEGIN IN EARNEST AFTER 01/00Z.

FOR THE SHORT TERM TEMPERATURES LOOK TO BE AROUND NORMAL.

LONG TERM...WEDNESDAY NIGHT-MONDAY
THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE SNOW POTENTIAL
ON WEDNESDAY NIGHT INTO THURSDAY AND HOW COLD TEMPERATURES WILL BE
THROUGH THE WEEK.

LATEST WATER VAPOR LOOP WAS SHOWING TWO DISTINCT UPPER LEVEL
VORTICITY LOBES MOVING THROUGH THE EASTERN PACIFIC. THE FIRST WAVE
WAS AROUND 42 DEG N AND 155 DEG W...WHILE THE TRAILING WAVE WAS 44
DEG N AND 176 N. THE MODELS SEEM TO BE IN FAIRLY GOOD AGREEMENT
IN SHOWING THE FIRST WAVE DIGGING ACROSS THE SOUTHERN ROCKIES
DURING THE NEXT COUPLE OF DAYS WHICH WILL CAUSE THE FLOW TO SPLIT AS
THE NEXT WAVE SKIRTS ACROSS THE NORTHERN ROCKIES LATER IN THE WEEK.

THE FIRST UPPER LEVEL WAVE SHOULD BEGIN TO IMPACT THE AREA
BEGINNING LATE WEDNESDAY AFTERNOON AND CONTINUING UNTIL THURSDAY
AFTERNOON. THIS WAVE WILL HAVE AID FROM THE RIGHT ENTRANCE REGION OF
THE UPPER LEVEL JET...BUT IT WILL BE RATHER SHORT LIVED. THE MODELS
ARE SHOWING SOME WEAK POTENTIAL INSTABILITY BETWEEN 700-500MB NEAR
CASPER AROUND 06Z. OTHERWISE...THIS SYSTEM SHOULD HAVE DEEP ENOUGH
MOISTURE AND LIFT BEHIND THE FRONT TO PRODUCE SOME LIGHT TO MODERATE
SNOWFALL BEGINNING LATE WEDNESDAY AFTERNOON IN THE NORTHERN HALF OF
THE FORECAST AREA WITH THIS SNOW SPREADING INTO THE SOUTHERN HALF OF
THE FORECAST AREA WEDNESDAY NIGHT. SNOWFALL ACCUMULATIONS SHOULD
GENERALLY BE AROUND 2-4 INCHES WITH HIGHER AMOUNTS IN THE MOUNTAINS
WHERE THE SNOW RATIOS WILL BE A LITTLE GREATER. THE MAIN LIMITATION
FOR MUCH IN THE WAY OF ACCUMULATION WILL BE THE SHORT LIVED NATURE OF
THE HEAVIER SNOWFALL. THIS WILL MOST LIKELY TAKE PLACE WEDNESDAY
EVENING WHEN THE COLD AIR AIR ADVECTION WILL BE THE STRONGEST WITH
SOME WEAK SHORT LIVED MID LEVEL FRONTOGENISIS (700-500MB) POSSIBLE.
THE SNOW SHOULD BEGIN TO TAPER OFF FROM NORTH TO SOUTH ON THURSDAY.

TEMPERATURES WILL TURN SHARPLY COLDER WITH GUSTY NORTH WINDS
AT 30 TO 40 MPH POSSIBLE ON WEDNESDAY EVENING INTO THURSDAY
MORNING. TEMPERATURES WILL ALSO NOT BUDGE MUCH ON THURSDAY WITH
HIGHS GENERALLY IN THE TEENS AND LOW 20S WHICH WILL ONLY BE A COUPLE
OF DEGREES WARMER THAN MORNING LOWS. MEANWHILE...LOWS ON THURSDAY
NIGHT COULD BE QUITE CHILLY (SINGLE DIGITS TO BELOW ZERO IN THE
VALLEYS) DUE TO THE 1040MB SURFACE HIGH SETTLING OVER THE AREA. WE
REALLY BACKED OFF ON HIGHS COMPARED TO THE GUIDANCE NUMBERS FOR
THIS TIME FRAME.

FRIDAY-MONDAY:
THE NEXT CONCERN DURING THIS TIME FRAME...WILL BE THE ARRIVAL OF
THE NEXT WAVE ON SATURDAY INTO SUNDAY. THE MAIN CONCERN WITH THIS
SYSTEM WILL BE HOW MUCH THIS TROF WILL AMPLIFY AS IT APPROACHES
THE CANADIAN ROCKIES. THIS WILL DETERMINE HOW MUCH COLD AIR SPILLS
INTO THE REGION THIS WEEKEND. IF THIS TROF DOES AMPLIFY...WE COULD
SEE ARCTIC AIR SPILLING INTO THE AREA BEGINNING SATURDAY AND
CONTINUING THROUGH MONDAY. SNOW CHANCES LOOK TO BE FAIRLY SMALL AT
THIS TIME WITH VERY LITTLE IF ANY ACCUMULATION. OF COURSE...THIS
WILL BE DEPENDENT ON HOW MUCH MOISTURE WILL BE AVAILABLE.

&&
FIRE WEATHER...
WIND SPEEDS WILL CONTINUE TO DIMINISH TONIGHT. OTHERWISE...THE
ONLY CONCERN WILL BE THE HIGH WIND POTENTIAL ON WEDNESDAY NIGHT
INTO THURSDAY...BUT THE PRECIPITATION CHANCES WILL BE QUITE HIGH
WHICH WILL LIMIT FIRE WEATHER CONCERNS.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.

&&

$$

SHORT TERM...GRIFFITH
LONG TERM/AVIATION...REC







AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

 403 AM CST TUE NOV 29 2011

.DISCUSSION...
938 PM CST

THE GOING FORECAST FOR TONIGHT INTO TUESDAY GENERALLY REMAINS ON
TRACK. THE UPPER LOW OVER THE LOWER TO MIDDLE PORTION OF THE
MISSISSIPPI VALLEY IS LOOKING VERY IMPRESSIVE ON WATER VAPOR
IMAGERY TONIGHT...WITH A WELL-DEFINED CLOSED CIRCULATION AND MOIST
CONVEYOR BELT FROM THE EASTERN GULF AND WESTERN ATLANTIC COMING
INTO THE SYSTEM. THE UPPER AIR PROFILES THIS EVENING PAINTED THE
PICTURE WITH THE COLD CORE UPPER LOW /-10C AT 850MB OVER MI/ AND A
VERY WARM AND MOIST NOSE TO THE NORTH /OVER 0C TD AT 700MB IN OH/.
THE WOLCOTT INDIANA WIND PROFILER IS SHOWING INCREASINGLY
EASTERLY WINDS UP TO 600 MB INDICATIVE OF THE SYSTEM TROWAL
DEVELOPMENT. THIS TROWAL AND ASSOCIATED ISENTROPIC OMEGA FROM THE
EAST STILL LOOK TO POINT DIRECTLY INTO NORTHWEST IN AND EASTERN IL
LATE TONIGHT INTO TUESDAY. SO DO EXPECT TO SEE RADAR ECHOES
CONTINUE TO BLOSSOM OVER THAT AREA. THE 29.00 RUC AND NAM CONTINUE
TO TREND EAST WITH THE WESTERN EDGE OF THE RAIN SHIELD...KEEPING
THE TIGHT GRADIENT BETWEEN NOTHING AND APPRECIABLE RAIN ABOUT 50
MILES EAST OF INTERSTATE 55. WILL GO AHEAD AND EASE THE NORTHWEST
SIDE OF THE POPS IN THE FORECAST...BUT OTHERWISE TIMING AND
ORIENTATION LOOK GOOD. PRECIPITATION AMOUNTS IN THE FAR SOUTHEAST
BETWEEN 1.25 AND 2 INCHES ARE PROBABLE. SUCH PREDICTED RAINFALL
AMOUNTS HAVE CAUSED THE FORECAST FOR THE KANKAKEE RIVER AT SHELBY
TO NOW GO ABOVE FLOOD STAGE. OTHER THAN A RIVER FLOOD WARNING FOR
THAT...NO OTHER CHANGES ARE PLANNED TO GOING HEADLINES THIS
EVENING. THE TRANSITION TO A MIX OR ALL SNOW DUE TO DYNAMIC
COOLING LOOKS PROBABLE WHEN THE UPPER LOW/PV ANOMALY ARE AT ITS
CLOSEST POINT DURING THE MID-AFTERNOON TO EARLY EVENING. THE
WINDOW OF TIME FOR PRECIPITATION TO FALL AS SNOW LOOKS SOMEWHAT
SHORTER IN THE NEW GUIDANCE...ENDING AROUND 9 PM TUE NIGHT.
STILL...THAT 4 TO 6 HOUR WINDOW IS ENOUGH TIME GIVEN THE FORCING
FOR HEAVIER RATES TO CAUSE SOME IMPACTS AND POTENTIALLY RESULT IN
MINOR SNOWFALL ACCUMULATIONS IN NORTHWEST IN.

MTF

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 10Z...

 * MVFR CIGS PERSISTING THROUGH MID MORNING
 * STRONG NORTH TO NORTHEAST WINDS TODAY WITH GUSTS OVER 35 KT
   POSSIBLE

KJB

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

DEEPENING LOW PRESSURE SYSTEM ACROSS THE TENNESSEE VALLEY
CONTINUES TO LIFT TO THE NORTHEAST AND TOWARDS THE OHIO VALLEY
TONIGHT. LATEST FORECAST TRENDS ARE KEEPING THE WESTERN EDGE OF
THE PRECIPITATION SHIELD FARTHER EAST THAN ORIGINALLY ANTICIPATED.
LATEST GUIDANCE IS IN AGREEMENT...AND WILL TREND IN THAT DIRECTION
WITH THE 04Z TAF AMD PACKAGE. WILL REMOVE ALL OF THE PRECIP FROM
ORD...SHIFT LESS WITH MDW AND THE SAME FOR GYY. MVFR CIGS SHOULD
REMAIN THROUGH THE OVERNIGHT HOURS AND GRADUALLY LIFT INTO THE
LATE MORNING HOURS...THOUGH THE FORECAST COULD GET A LITTLE TRICKY
FOR MDW IF ANY PRECIP DOES WORK FAR ENOUGH ACROSS THE TERMINALS.
PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN AND WINDS WILL
INCREASE THROUGH THE MORNING HOURS. NORTHERLY GUSTS WILL INCREASE
TO A SUSTAINED LOWER 20 KT READING WITH GUSTS PEAKING AOA 35 KT
INTO THE EARLY AFTERNOON HOURS.

SHEA

//ORD AND MDW CONFIDENCE...UPDATED 10Z...

 * MODERATE CONFIDENCE IN CIG TREND
 * HIGH CONFIDENCE IN WIND FORECAST
 * MODERATE CONFIDENCE IN PRECIPITATION REMAINING SOUTH OF ORD

KJB

//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...

 * WEDNESDAY...VFR.
 * THURSDAY...VFR. CHC LGT SN IN THE EVENING.
 * FRIDAY...CHC SHSN IN THE MORNING.
 * SATURDAY...VFR.
 * SUNDAY...CHC RA/SN. MVFR POSSIBLE.

SHEA

&&

.MARINE...
344 AM CST

...HIGH GALES ON CENTRAL AND SOUTHERN LAKE MICHIGAN TODAY...

.LOW PRESSURE OF OVER THE LOWER OHIO VALLEY EARLY THIS MORNING
WILL MOVE NE TO LAKE ERIE BY EVENING WHILE HIGH PRESSURE MOVES
E ACROSS THE PLAINS. THE VERY STRONG PRESSURE GRADIENT DEVELOPING
OVER THE WESTERN GREAT LAKES HAS RESULTED IN NORTHEAST TO NORTH
WINDS INCREASING SIGNIFICANTLY...AND THE WITH VE REACHING GALE TO
HIGH GALE FORCE LATER THIS MORNING. THE GALE FORCE WINDS WILL
PERSIST INTO TONIGHT UNTIL THE DEEPENING LOW MOVES FURTHER
NE INTO SOUTHERN QUEBEC. WINDS DIMINISH WED AS THE HIGH SHIFTS
EAST OVER THE WESTERN GREAT LAKES AND OHIO VALLEY.

TRS

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ006-ILZ014 UNTIL 9 PM TUESDAY.

     LAKESHORE FLOOD ADVISORY...ILZ006-ILZ014 UNTIL 10 AM WEDNESDAY.

     FLOOD WATCH...ILZ033 UNTIL 9 PM TUESDAY.

IN...FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 9 PM
     TUESDAY.

     LAKESHORE FLOOD ADVISORY...INZ001-INZ002 UNTIL 3 PM WEDNESDAY.

     WIND ADVISORY...INZ001-INZ002 UNTIL 9 PM TUESDAY.

     WINTER WEATHER ADVISORY...INZ010-INZ011-INZ019...NOON TUESDAY TO
     MIDNIGHT WEDNESDAY.

LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
     LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
     LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
     LMZ874-LMZ876-LMZ878 UNTIL 9 AM WEDNESDAY.

&&

$$





AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

 349 AM CST TUE NOV 29 2011

.DISCUSSION...
938 PM CST

THE GOING FORECAST FOR TONIGHT INTO TUESDAY GENERALLY REMAINS ON
TRACK. THE UPPER LOW OVER THE LOWER TO MIDDLE PORTION OF THE
MISSISSIPPI VALLEY IS LOOKING VERY IMPRESSIVE ON WATER VAPOR
IMAGERY TONIGHT...WITH A WELL-DEFINED CLOSED CIRCULATION AND MOIST
CONVEYOR BELT FROM THE EASTERN GULF AND WESTERN ATLANTIC COMING
INTO THE SYSTEM. THE UPPER AIR PROFILES THIS EVENING PAINTED THE
PICTURE WITH THE COLD CORE UPPER LOW /-10C AT 850MB OVER MI/ AND A
VERY WARM AND MOIST NOSE TO THE NORTH /OVER 0C TD AT 700MB IN OH/.
THE WOLCOTT INDIANA WIND PROFILER IS SHOWING INCREASINGLY
EASTERLY WINDS UP TO 600 MB INDICATIVE OF THE SYSTEM TROWAL
DEVELOPMENT. THIS TROWAL AND ASSOCIATED ISENTROPIC OMEGA FROM THE
EAST STILL LOOK TO POINT DIRECTLY INTO NORTHWEST IN AND EASTERN IL
LATE TONIGHT INTO TUESDAY. SO DO EXPECT TO SEE RADAR ECHOES
CONTINUE TO BLOSSOM OVER THAT AREA. THE 29.00 RUC AND NAM CONTINUE
TO TREND EAST WITH THE WESTERN EDGE OF THE RAIN SHIELD...KEEPING
THE TIGHT GRADIENT BETWEEN NOTHING AND APPRECIABLE RAIN ABOUT 50
MILES EAST OF INTERSTATE 55. WILL GO AHEAD AND EASE THE NORTHWEST
SIDE OF THE POPS IN THE FORECAST...BUT OTHERWISE TIMING AND
ORIENTATION LOOK GOOD. PRECIPITATION AMOUNTS IN THE FAR SOUTHEAST
BETWEEN 1.25 AND 2 INCHES ARE PROBABLE. SUCH PREDICTED RAINFALL
AMOUNTS HAVE CAUSED THE FORECAST FOR THE KANKAKEE RIVER AT SHELBY
TO NOW GO ABOVE FLOOD STAGE. OTHER THAN A RIVER FLOOD WARNING FOR
THAT...NO OTHER CHANGES ARE PLANNED TO GOING HEADLINES THIS
EVENING. THE TRANSITION TO A MIX OR ALL SNOW DUE TO DYNAMIC
COOLING LOOKS PROBABLE WHEN THE UPPER LOW/PV ANOMALY ARE AT ITS
CLOSEST POINT DURING THE MID-AFTERNOON TO EARLY EVENING. THE
WINDOW OF TIME FOR PRECIPITATION TO FALL AS SNOW LOOKS SOMEWHAT
SHORTER IN THE NEW GUIDANCE...ENDING AROUND 9 PM TUE NIGHT.
STILL...THAT 4 TO 6 HOUR WINDOW IS ENOUGH TIME GIVEN THE FORCING
FOR HEAVIER RATES TO CAUSE SOME IMPACTS AND POTENTIALLY RESULT IN
MINOR SNOWFALL ACCUMULATIONS IN NORTHWEST IN.

MTF

&&

.AVIATION...

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

 * MVFR CIGS PERSISTING THROUGH MID MORNING
 * STRONG NORTH TO NORTHEAST WINDS TODAY WITH GUSTS OVER 35 KT
   POSSIBLE

KJB

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

DEEPENING LOW PRESSURE SYSTEM ACROSS THE TENNESSEE VALLEY
CONTINUES TO LIFT TO THE NORTHEAST AND TOWARDS THE OHIO VALLEY
TONIGHT. LATEST FORECAST TRENDS ARE KEEPING THE WESTERN EDGE OF
THE PRECIPITATION SHIELD FARTHER EAST THAN ORIGINALLY ANTICIPATED.
LATEST GUIDANCE IS IN AGREEMENT...AND WILL TREND IN THAT DIRECTION
WITH THE 04Z TAF AMD PACKAGE. WILL REMOVE ALL OF THE PRECIP FROM
ORD...SHIFT LESS WITH MDW AND THE SAME FOR GYY. MVFR CIGS SHOULD
REMAIN THROUGH THE OVERNIGHT HOURS AND GRADUALLY LIFT INTO THE
LATE MORNING HOURS...THOUGH THE FORECAST COULD GET A LITTLE TRICKY
FOR MDW IF ANY PRECIP DOES WORK FAR ENOUGH ACROSS THE TERMINALS.
PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN AND WINDS WILL
INCREASE THROUGH THE MORNING HOURS. NORTHERLY GUSTS WILL INCREASE
TO A SUSTAINED LOWER 20 KT READING WITH GUSTS PEAKING AOA 35 KT
INTO THE EARLY AFTERNOON HOURS.

SHEA

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

 * MODERATE CONFIDENCE IN CIG TREND
 * HIGH CONFIDENCE IN WIND FORECAST
 * MODERATE CONFIDENCE IN PRECIPITATION REMAINING SOUTH OF ORD

KJB

//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...

 * WEDNESDAY...VFR.
 * THURSDAY...VFR. CHC LGT SN IN THE EVENING.
 * FRIDAY...CHC SHSN IN THE MORNING.
 * SATURDAY...VFR.
 * SUNDAY...CHC RA/SN. MVFR POSSIBLE.

SHEA

&&

.MARINE...
344 AM CST

...HIGH GALES ON CENTRAL AND SOUTHERN LAKE MICHIGAN TODAY...

.LOW PRESSURE OF OVER THE LOWER OHIO VALLEY EARLY THIS MORNING
WILL MOVE NE TO LAKE ERIE BY EVENING WHILE HIGH PRESSURE MOVES
E ACROSS THE PLAINS. THE VERY STRONG PRESSURE GRADIENT DEVELOPING
OVER THE WESTERN GREAT LAKES HAS RESULTED IN NORTHEAST TO NORTH
WINDS INCREASING SIGNIFICANTLY...AND THE WITH VE REACHING GALE TO
HIGH GALE FORCE LATER THIS MORNING. THE GALE FORCE WINDS WILL
PERSIST INTO TONIGHT UNTIL THE DEEPENING LOW MOVES FURTHER
NE INTO SOUTHERN QUEBEC. WINDS DIMINISH WED AS THE HIGH SHIFTS
EAST OVER THE WESTERN GREAT LAKES AND OHIO VALLEY.

TRS

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ006-ILZ014 UNTIL 9 PM TUESDAY.

     LAKESHORE FLOOD ADVISORY...ILZ006-ILZ014 UNTIL 10 AM WEDNESDAY.

     FLOOD WATCH...ILZ033 UNTIL 9 PM TUESDAY.

IN...FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 9 PM
     TUESDAY.

     LAKESHORE FLOOD ADVISORY...INZ001-INZ002 UNTIL 3 PM WEDNESDAY.

     WIND ADVISORY...INZ001-INZ002 UNTIL 9 PM TUESDAY.

     WINTER WEATHER ADVISORY...INZ010-INZ011-INZ019...NOON TUESDAY TO
     MIDNIGHT WEDNESDAY.

LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
     LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
     LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
     LMZ874-LMZ876-LMZ878 UNTIL 9 AM WEDNESDAY.

&&

$$










AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

 211 AM CST TUE NOV 29 2011

.DISCUSSION...
938 PM CST

THE GOING FORECAST FOR TONIGHT INTO TUESDAY GENERALLY REMAINS ON
TRACK. THE UPPER LOW OVER THE LOWER TO MIDDLE PORTION OF THE
MISSISSIPPI VALLEY IS LOOKING VERY IMPRESSIVE ON WATER VAPOR
IMAGERY TONIGHT...WITH A WELL-DEFINED CLOSED CIRCULATION AND MOIST
CONVEYOR BELT FROM THE EASTERN GULF AND WESTERN ATLANTIC COMING
INTO THE SYSTEM. THE UPPER AIR PROFILES THIS EVENING PAINTED THE
PICTURE WITH THE COLD CORE UPPER LOW /-10C AT 850MB OVER MI/ AND A
VERY WARM AND MOIST NOSE TO THE NORTH /OVER 0C TD AT 700MB IN OH/.
THE WOLCOTT INDIANA WIND PROFILER IS SHOWING INCREASINGLY
EASTERLY WINDS UP TO 600 MB INDICATIVE OF THE SYSTEM TROWAL
DEVELOPMENT. THIS TROWAL AND ASSOCIATED ISENTROPIC OMEGA FROM THE
EAST STILL LOOK TO POINT DIRECTLY INTO NORTHWEST IN AND EASTERN IL
LATE TONIGHT INTO TUESDAY. SO DO EXPECT TO SEE RADAR ECHOES
CONTINUE TO BLOSSOM OVER THAT AREA. THE 29.00 RUC AND NAM CONTINUE
TO TREND EAST WITH THE WESTERN EDGE OF THE RAIN SHIELD...KEEPING
THE TIGHT GRADIENT BETWEEN NOTHING AND APPRECIABLE RAIN ABOUT 50
MILES EAST OF INTERSTATE 55. WILL GO AHEAD AND EASE THE NORTHWEST
SIDE OF THE POPS IN THE FORECAST...BUT OTHERWISE TIMING AND
ORIENTATION LOOK GOOD. PRECIPITATION AMOUNTS IN THE FAR SOUTHEAST
BETWEEN 1.25 AND 2 INCHES ARE PROBABLE. SUCH PREDICTED RAINFALL
AMOUNTS HAVE CAUSED THE FORECAST FOR THE KANKAKEE RIVER AT SHELBY
TO NOW GO ABOVE FLOOD STAGE. OTHER THAN A RIVER FLOOD WARNING FOR
THAT...NO OTHER CHANGES ARE PLANNED TO GOING HEADLINES THIS
EVENING. THE TRANSITION TO A MIX OR ALL SNOW DUE TO DYNAMIC
COOLING LOOKS PROBABLE WHEN THE UPPER LOW/PV ANOMALY ARE AT ITS
CLOSEST POINT DURING THE MID-AFTERNOON TO EARLY EVENING. THE
WINDOW OF TIME FOR PRECIPITATION TO FALL AS SNOW LOOKS SOMEWHAT
SHORTER IN THE NEW GUIDANCE...ENDING AROUND 9 PM TUE NIGHT.
STILL...THAT 4 TO 6 HOUR WINDOW IS ENOUGH TIME GIVEN THE FORCING
FOR HEAVIER RATES TO CAUSE SOME IMPACTS AND POTENTIALLY RESULT IN
MINOR SNOWFALL ACCUMULATIONS IN NORTHWEST IN.

MTF

&&

.AVIATION...

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

 * MVFR CIGS PERSISTING THROUGH MID MORNING
 * STRONG NORTH TO NORTHEAST WINDS TODAY WITH GUSTS OVER 35 KT
   POSSIBLE

KJB

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

DEEPENING LOW PRESSURE SYSTEM ACROSS THE TENNESSEE VALLEY
CONTINUES TO LIFT TO THE NORTHEAST AND TOWARDS THE OHIO VALLEY
TONIGHT. LATEST FORECAST TRENDS ARE KEEPING THE WESTERN EDGE OF
THE PRECIPITATION SHIELD FARTHER EAST THAN ORIGINALLY ANTICIPATED.
LATEST GUIDANCE IS IN AGREEMENT...AND WILL TREND IN THAT DIRECTION
WITH THE 04Z TAF AMD PACKAGE. WILL REMOVE ALL OF THE PRECIP FROM
ORD...SHIFT LESS WITH MDW AND THE SAME FOR GYY. MVFR CIGS SHOULD
REMAIN THROUGH THE OVERNIGHT HOURS AND GRADUALLY LIFT INTO THE
LATE MORNING HOURS...THOUGH THE FORECAST COULD GET A LITTLE TRICKY
FOR MDW IF ANY PRECIP DOES WORK FAR ENOUGH ACROSS THE TERMINALS.
PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN AND WINDS WILL
INCREASE THROUGH THE MORNING HOURS. NORTHERLY GUSTS WILL INCREASE
TO A SUSTAINED LOWER 20 KT READING WITH GUSTS PEAKING AOA 35 KT
INTO THE EARLY AFTERNOON HOURS.

SHEA

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

 * MODERATE CONFIDENCE IN CIG TREND
 * HIGH CONFIDENCE IN WIND FORECAST
 * MODERATE CONFIDENCE IN PRECIPITATION REMAINING SOUTH OF ORD

KJB

//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...

 * WEDNESDAY...VFR.
 * THURSDAY...VFR. CHC LGT SN IN THE EVENING.
 * FRIDAY...CHC SHSN IN THE MORNING.
 * SATURDAY...VFR.
 * SUNDAY...CHC RA/SN. MVFR POSSIBLE.

SHEA

&&

.MARINE...
255 PM CST

A SURFACE RIDGE AXIS EXTENDS ACROSS THE MIDDLE OF LAKE MICHIGAN
WITH SOUTHWEST WINDS OVER THE NORTHERN PORTIONS OF THE LAKE AND
NORTHEAST WINDS OVER THE SOUTH. DEEPENING LOW PRESSURE OVER
EASTERN TENNESSEE AND KENTUCKY WILL TRACK NORTHWARD THIS
EVENING...FORCING THE RIDGE AXIS TO THE NORTH AND STRENGTHENING
THE PRESSURE GRADIENT OVER LAKE MICHIGAN. WINDS WILL QUICKLY
STRENGTHEN THROUGH THE EVENING AND OVERNIGHT WILL GALE FORCE WINDS
DEVELOPING BY THE EARLY MORNING HOURS. GALES SHOULD INITIALLY DEVELOP
OVER THE FAR SOUTHERN PORTIONS OF THE LAKE...INCLUDING THE
NEARSHORE AND OFFSHORE WATERS...BUT THE GALES SHOULD RAPIDLY
SPREAD NORTH...ENGULFING ALL OF THE LAKE BY DAYBREAK. HIGHER END
GALES SHOULD DEVELOP BY MIDDAY AS THE SFC LOW MOVES OVER THE
EASTERN GREAT LAKES...WITH OCCASIONAL STORM FORCE GUSTS TO 50KT
POSSIBLE OVER THE SOUTHERN 2/3RDS OF THE LAKE. GALES SHOULD BEGIN
TO WIND DOWN WEDNESDAY MORNING AS THE SURFACE LOW MOVES INTO
QUEBEC AND A WEAK RIDGE CROSSES THE UPPER MISSISSIPPI VALLEY AND
INTO THE WESTERN GREAT LAKES REGION.

WHILE THE GALES SHOULD SUBSIDE WEDNESDAY MORNING...HIGH WAVES
HAZARDOUS TO SMALL CRAFT WILL LIKELY PERSIST THROUGH WEDNESDAY
NIGHT.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ006-ILZ014...6 AM TUESDAY TO 9 PM TUESDAY.

     LAKESHORE FLOOD ADVISORY...ILZ006-ILZ014...6 AM TUESDAY TO 10 AM
     WEDNESDAY.

     FLOOD WATCH...ILZ033 UNTIL 9 PM TUESDAY.

IN...FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 9 PM
     TUESDAY.

     LAKESHORE FLOOD ADVISORY...INZ001-INZ002...6 AM TUESDAY TO 3 PM
     WEDNESDAY.

     WIND ADVISORY...INZ001-INZ002...6 AM TUESDAY TO 9 PM TUESDAY.

LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
     LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
     LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
     LMZ874-LMZ876-LMZ878 UNTIL 9 AM WEDNESDAY.

     SMALL CRAFT ADVISORY...NEARSHORE WATERS
     UNTIL 3 AM TUESDAY.

&&

$$






AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

 1052 PM CST MON NOV 28 2011

.DISCUSSION...
938 PM CST

THE GOING FORECAST FOR TONIGHT INTO TUESDAY GENERALLY REMAINS ON
TRACK. THE UPPER LOW OVER THE LOWER TO MIDDLE PORTION OF THE
MISSISSIPPI VALLEY IS LOOKING VERY IMPRESSIVE ON WATER VAPOR
IMAGERY TONIGHT...WITH A WELL-DEFINED CLOSED CIRCULATION AND MOIST
CONVEYOR BELT FROM THE EASTERN GULF AND WESTERN ATLANTIC COMING
INTO THE SYSTEM. THE UPPER AIR PROFILES THIS EVENING PAINTED THE
PICTURE WITH THE COLD CORE UPPER LOW /-10C AT 850MB OVER MI/ AND A
VERY WARM AND MOIST NOSE TO THE NORTH /OVER 0C TD AT 700MB IN OH/.
THE WOLCOTT INDIANA WIND PROFILER IS SHOWING INCREASINGLY
EASTERLY WINDS UP TO 600 MB INDICATIVE OF THE SYSTEM TROWAL
DEVELOPMENT. THIS TROWAL AND ASSOCIATED ISENTROPIC OMEGA FROM THE
EAST STILL LOOK TO POINT DIRECTLY INTO NORTHWEST IN AND EASTERN IL
LATE TONIGHT INTO TUESDAY. SO DO EXPECT TO SEE RADAR ECHOES
CONTINUE TO BLOSSOM OVER THAT AREA. THE 29.00 RUC AND NAM CONTINUE
TO TREND EAST WITH THE WESTERN EDGE OF THE RAIN SHIELD...KEEPING
THE TIGHT GRADIENT BETWEEN NOTHING AND APPRECIABLE RAIN ABOUT 50
MILES EAST OF INTERSTATE 55. WILL GO AHEAD AND EASE THE NORTHWEST
SIDE OF THE POPS IN THE FORECAST...BUT OTHERWISE TIMING AND
ORIENTATION LOOK GOOD. PRECIPITATION AMOUNTS IN THE FAR SOUTHEAST
BETWEEN 1.25 AND 2 INCHES ARE PROBABLE. SUCH PREDICTED RAINFALL
AMOUNTS HAVE CAUSED THE FORECAST FOR THE KANKAKEE RIVER AT SHELBY
TO NOW GO ABOVE FLOOD STAGE. OTHER THAN A RIVER FLOOD WARNING FOR
THAT...NO OTHER CHANGES ARE PLANNED TO GOING HEADLINES THIS
EVENING. THE TRANSITION TO A MIX OR ALL SNOW DUE TO DYNAMIC
COOLING LOOKS PROBABLE WHEN THE UPPER LOW/PV ANOMALY ARE AT ITS
CLOSEST POINT DURING THE MID-AFTERNOON TO EARLY EVENING. THE
WINDOW OF TIME FOR PRECIPITATION TO FALL AS SNOW LOOKS SOMEWHAT
SHORTER IN THE NEW GUIDANCE...ENDING AROUND 9 PM TUE NIGHT.
STILL...THAT 4 TO 6 HOUR WINDOW IS ENOUGH TIME GIVEN THE FORCING
FOR HEAVIER RATES TO CAUSE SOME IMPACTS AND POTENTIALLY RESULT IN
MINOR SNOWFALL ACCUMULATIONS IN NORTHWEST IN.

MTF

&&

.AVIATION...

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

 * MVFR CIGS PERSISTING THROUGH THE EVENING
 * NORTHEAST WIND INCREASING OVERNIGHT...WITH STRONG GUSTS TOMORROW
 * RAIN DEVELOPING TONIGHT MAINLY SOUTHEAST OF ORD

SHEA

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

DEEPENING LOW PRESSURE SYSTEM ACROSS THE TENNESSEE VALLEY
CONTINUES TO LIFT TO THE NORTHEAST AND TOWARDS THE OHIO VALLEY
TONIGHT. LATEST FORECAST TRENDS ARE KEEPING THE WESTERN EDGE OF
THE PRECIPITATION SHIELD FARTHER EAST THAN ORIGINALLY ANTICIPATED.
LATEST GUIDANCE IS IN AGREEMENT...AND WILL TREND IN THAT DIRECTION
WITH THE 04Z TAF AMD PACAKGE. WILL REMOVE ALL OF THE PRECIP FROM
ORD...SHIFT LESS WITH MDW AND THE SAME FOR GYY. MVFR CIGS SHOULD
REMAIN THROUGH THE OVERNIGHT HOURS AND GRADUALLY LIFT INTO THE
LATE MORNING HOURS...THOUGH THE FORECAST COULD GET A LITTLE TRICKY
FOR MDW IF ANY PRECIP DOES WORK FAR ENOUGH ACROSS THE TERMINALS.
PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN AND WINDS WILL
INCREASE THROUGH THE MORNING HOURS. NORTERLY GUSTS WILL INCREASE
TO A SUSTAINED LOWER 20 KT READING WITH GUSTS PEAKING AOA 35 KT
INTO THE EARLY AFTERNOON HOURS.

SHEA

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

 * MODERATE CONFIDENCE IN CIG TREND
 * HIGH CONFIDENCE IN WIND FORECAST...MOD/HIGH IN GUST FORECAST
 * MODERATE CONFIDENCE IN PRECIPITATION TIMING / COVERAGE LATE
   TONIGHT INTO TUESDAY...STAYING EAST OR ORD

SHEA

//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...

 * WEDNESDAY...VFR.
 * THURSDAY...VFR. CHC LGT SN IN THE EVENING.
 * FRIDAY...CHC SHSN IN THE MORNING.
 * SATURDAY...VFR.
 * SUNDAY...CHC RA/SN. MVFR POSSIBLE.

SHEA

&&

.MARINE...
255 PM CST

A SURFACE RIDGE AXIS EXTENDS ACROSS THE MIDDLE OF LAKE MICHIGAN
WITH SOUTHWEST WINDS OVER THE NORTHERN PORTIONS OF THE LAKE AND
NORTHEAST WINDS OVER THE SOUTH. DEEPENING LOW PRESSURE OVER
EASTERN TENNESSEE AND KENTUCKY WILL TRACK NORTHWARD THIS
EVENING...FORCING THE RIDGE AXIS TO THE NORTH AND STRENGTHENING
THE PRESSURE GRADIENT OVER LAKE MICHIGAN. WINDS WILL QUICKLY
STRENGTHEN THROUGH THE EVENING AND OVERNIGHT WILL GALE FORCE WINDS
DEVELOPING BY THE EARLY MORNING HOURS. GALES SHOULD INITIALLY DEVELOP
OVER THE FAR SOUTHERN PORTIONS OF THE LAKE...INCLUDING THE
NEARSHORE AND OFFSHORE WATERS...BUT THE GALES SHOULD RAPIDLY
SPREAD NORTH...ENGULFING ALL OF THE LAKE BY DAYBREAK. HIGHER END
GALES SHOULD DEVELOP BY MIDDAY AS THE SFC LOW MOVES OVER THE
EASTERN GREAT LAKES...WITH OCCASIONAL STORM FORCE GUSTS TO 50KT
POSSIBLE OVER THE SOUTHERN 2/3RDS OF THE LAKE. GALES SHOULD BEGIN
TO WIND DOWN WEDNESDAY MORNING AS THE SURFACE LOW MOVES INTO
QUEBEC AND A WEAK RIDGE CROSSES THE UPPER MISSISSIPPI VALLEY AND
INTO THE WESTERN GREAT LAKES REGION.

WHILE THE GALES SHOULD SUBSIDE WEDNESDAY MORNING...HIGH WAVES
HAZARDOUS TO SMALL CRAFT WILL LIKELY PERSIST THROUGH WEDNESDAY
NIGHT.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ006-ILZ014...6 AM TUESDAY TO 9 PM TUESDAY.

     LAKESHORE FLOOD ADVISORY...ILZ006-ILZ014...6 AM TUESDAY TO 10 AM
     WEDNESDAY.

     FLOOD WATCH...ILZ033 UNTIL 9 PM TUESDAY.

IN...FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 9 PM
     TUESDAY.

     LAKESHORE FLOOD ADVISORY...INZ001-INZ002...6 AM TUESDAY TO 3 PM
     WEDNESDAY.

     WIND ADVISORY...INZ001-INZ002...6 AM TUESDAY TO 9 PM TUESDAY.

LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
     LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
     LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
     LMZ874-LMZ876-LMZ878...3 AM TUESDAY TO 9 AM WEDNESDAY.

     SMALL CRAFT ADVISORY...NEARSHORE WATERS
     UNTIL 3 AM TUESDAY.

&&

$$





AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

 1012 PM CST MON NOV 28 2011

.DISCUSSION...
938 PM CST

THE GOING FORECAST FOR TONIGHT INTO TUESDAY GENERALLY REMAINS ON
TRACK. THE UPPER LOW OVER THE LOWER TO MIDDLE PORTION OF THE
MISSISSIPPI VALLEY IS LOOKING VERY IMPRESSIVE ON WATER VAPOR
IMAGERY TONIGHT...WITH A WELL-DEFINED CLOSED CIRCULATION AND MOIST
CONVEYOR BELT FROM THE EASTERN GULF AND WESTERN ATLANTIC COMING
INTO THE SYSTEM. THE UPPER AIR PROFILES THIS EVENING PAINTED THE
PICTURE WITH THE COLD CORE UPPER LOW /-10C AT 850MB OVER MI/ AND A
VERY WARM AND MOIST NOSE TO THE NORTH /OVER 0C TD AT 700MB IN OH/.
THE WOLCOTT INDIANA WIND PROFILER IS SHOWING INCREASINGLY
EASTERLY WINDS UP TO 600 MB INDICATIVE OF THE SYSTEM TROWAL
DEVELOPMENT. THIS TROWAL AND ASSOCIATED ISENTROPIC OMEGA FROM THE
EAST STILL LOOK TO POINT DIRECTLY INTO NORTHWEST IN AND EASTERN IL
LATE TONIGHT INTO TUESDAY. SO DO EXPECT TO SEE RADAR ECHOES
CONTINUE TO BLOSSOM OVER THAT AREA. THE 29.00 RUC AND NAM CONTINUE
TO TREND EAST WITH THE WESTERN EDGE OF THE RAIN SHIELD...KEEPING
THE TIGHT GRADIENT BETWEEN NOTHING AND APPRECIABLE RAIN ABOUT 50
MILES EAST OF INTERSTATE 55. WILL GO AHEAD AND EASE THE NORTHWEST
SIDE OF THE POPS IN THE FORECAST...BUT OTHERWISE TIMING AND
ORIENTATION LOOK GOOD. PRECIPITATION AMOUNTS IN THE FAR SOUTHEAST
BETWEEN 1.25 AND 2 INCHES ARE PROBABLE. SUCH PREDICTED RAINFALL
AMOUNTS HAVE CAUSED THE FORECAST FOR THE KANKAKEE RIVER AT SHELBY
TO NOW GO ABOVE FLOOD STAGE. OTHER THAN A RIVER FLOOD WARNING FOR
THAT...NO OTHER CHANGES ARE PLANNED TO GOING HEADLINES THIS
EVENING. THE TRANSITION TO A MIX OR ALL SNOW DUE TO DYNAMIC
COOLING LOOKS PROBABLE WHEN THE UPPER LOW/PV ANOMALY ARE AT ITS
CLOSEST POINT DURING THE MID-AFTERNOON TO EARLY EVENING. THE
WINDOW OF TIME FOR PRECIPITATION TO FALL AS SNOW LOOKS SOMEWHAT
SHORTER IN THE NEW GUIDANCE...ENDING AROUND 9 PM TUE NIGHT.
STILL...THAT 4 TO 6 HOUR WINDOW IS ENOUGH TIME GIVEN THE FORCING
FOR HEAVIER RATES TO CAUSE SOME IMPACTS AND POTENTIALLY RESULT IN
MINOR SNOWFALL ACCUMULATIONS IN NORTHWEST IN.

MTF

&&

.AVIATION...

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

 * MVFR CIGS PERSISTING THROUGH THE EVENING
 * NORTHEAST WIND INCREASING OVERNIGHT...WITH STRONG GUSTS TOMORROW
 * RAIN DEVELOPING TONIGHT MAINLY SOUTHEAST OF ORD

SHEA

//DISCUSSION...UPDATED 04Z...

LATEST FORECAST TRENDS ARE KEEPING THE WESTERN EDGE OF THE
PRECIPITATION SHIELD FARTHER EAST THAN ORIGINALLY ANTICIPATED.
LATEST GUIDANCE IS IN AGREEMENT...AND WILL TREND IN THAT DIRECTION
WITH THE 04Z TAF AMD PACAKGE. WILL REMOVE ALL OF THE PRECIP FROM
ORD...SHIFT LOWER WITH MDW AND THE SAME FOR GYY. OTHERWISE...GOING
WIND AND CIG FORECAST LOOKS TO REMAIN ON TRACK. MVFR CIGS SHOULD
REMAIN THROUGH THE OVERNIGHT HOURS AND GRADUALLY LIFT INTO THE
LATE MORNING HOURS. PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN AND
WINDS WILL INCREASE THROUGH THE MORNING HOURS.

SHEA

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

DEEPENING LOW PRESSURE SYSTEM ACROSS THE TENNESSEE VALLEY WILL
CONTINUE TO LIFT NORTH AND INTO THE OHIO VALLEY THIS EVENING.
IMPACT TO THE TERMINALS WILL TAKE PLACE OVERNIGHT...WITH RAIN
BEGINNING TO OVERSPREAD GYY BEYOND 05Z TONIGHT...AND LATER MOVING
ACROSS MDW. ORD AND DPA ARE WILDCARDS AS TO HOW LIKELY IT WILL
RAIN LATE TONIGHT AND INTO TOMORROW MORNING...VS JUST BEING IN THE
VC TO THE SOUTH AND EAST. PRESENT THINKING IS THAT THERE SHOULD BE
A WELL DEFINED LINE BETWEEN PRECIP AND NO PRECIP...AND THAT ORD
MAY STAY ON THE NO PRECIP SIDE. CONDITIONS WILL BE WORSE FOR MDW
AND WORSE YET FOR GYY. THAT SAID...WINDS WILL PICK UP TOMORROW FOR
ALL OF THE TERMINALS AND INCREASE TO A SUSTAINED 20+ KT RANGE AND
GUST INTO THE MIDDLE 30 KT RANGE. CIG TRENDS MAY BE A LITTLE
TRICKY WHERE THERE IS NO PRECIP FALLING...AS A WELL MIXED BOUNDARY
LAYER SHOULD KEEP CIGS FROM COMPLETELY TANKING...BUT THEY WILL
EASILY FALL TO LOW END MVFR AND POTENTIALLY IFR FOR LOCATIONS THAT
SEE RAIN /E.G. MDW AND GYY/.

SHEA

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

 * MODERATE CONFIDENCE IN CIG TREND
 * HIGH CONFIDENCE IN WIND FORECAST...MOD/HIGH IN GUST FORECAST
 * LOW CONFIDENCE IN PRECIPITATION TIMING / COVERAGE LATE TONIGHT
   INTO TUESDAY

SHEA

//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...

 * WEDNESDAY...VFR.
 * THURSDAY...VFR. CHC LGT SN IN THE EVENING.
 * FRIDAY...CHC SHSN IN THE MORNING.
 * SATURDAY...VFR.
 * SUNDAY...CHC RA/SN. MVFR POSSIBLE.

SHEA

&&

.MARINE...
255 PM CST

A SURFACE RIDGE AXIS EXTENDS ACROSS THE MIDDLE OF LAKE MICHIGAN
WITH SOUTHWEST WINDS OVER THE NORTHERN PORTIONS OF THE LAKE AND
NORTHEAST WINDS OVER THE SOUTH. DEEPENING LOW PRESSURE OVER
EASTERN TENNESSEE AND KENTUCKY WILL TRACK NORTHWARD THIS
EVENING...FORCING THE RIDGE AXIS TO THE NORTH AND STRENGTHENING
THE PRESSURE GRADIENT OVER LAKE MICHIGAN. WINDS WILL QUICKLY
STRENGTHEN THROUGH THE EVENING AND OVERNIGHT WILL GALE FORCE WINDS
DEVELOPING BY THE EARLY MORNING HOURS. GALES SHOULD INITIALLY DEVELOP
OVER THE FAR SOUTHERN PORTIONS OF THE LAKE...INCLUDING THE
NEARSHORE AND OFFSHORE WATERS...BUT THE GALES SHOULD RAPIDLY
SPREAD NORTH...ENGULFING ALL OF THE LAKE BY DAYBREAK. HIGHER END
GALES SHOULD DEVELOP BY MIDDAY AS THE SFC LOW MOVES OVER THE
EASTERN GREAT LAKES...WITH OCCASIONAL STORM FORCE GUSTS TO 50KT
POSSIBLE OVER THE SOUTHERN 2/3RDS OF THE LAKE. GALES SHOULD BEGIN
TO WIND DOWN WEDNESDAY MORNING AS THE SURFACE LOW MOVES INTO
QUEBEC AND A WEAK RIDGE CROSSES THE UPPER MISSISSIPPI VALLEY AND
INTO THE WESTERN GREAT LAKES REGION.

WHILE THE GALES SHOULD SUBSIDE WEDNESDAY MORNING...HIGH WAVES
HAZARDOUS TO SMALL CRAFT WILL LIKELY PERSIST THROUGH WEDNESDAY
NIGHT.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ006-ILZ014...6 AM TUESDAY TO 9 PM TUESDAY.

     LAKESHORE FLOOD ADVISORY...ILZ006-ILZ014...6 AM TUESDAY TO 10 AM
     WEDNESDAY.

     FLOOD WATCH...ILZ033 UNTIL 9 PM TUESDAY.

IN...FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 9 PM
     TUESDAY.

     LAKESHORE FLOOD ADVISORY...INZ001-INZ002...6 AM TUESDAY TO 3 PM
     WEDNESDAY.

     WIND ADVISORY...INZ001-INZ002...6 AM TUESDAY TO 9 PM TUESDAY.

LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
     LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
     LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
     LMZ874-LMZ876-LMZ878...3 AM TUESDAY TO 9 AM WEDNESDAY.

     SMALL CRAFT ADVISORY...NEARSHORE WATERS
     UNTIL 3 AM TUESDAY.

&&

$$





AREA FORECAST DISCUSSION...CORRECTED

NWS NORTHERN INDIANA

 446 AM EST TUE NOV 29 2011

.SHORT TERM...
DYNAMIC/IMPRESSIVE SRN STREAM WAVE CONTS TO WRAP UP ACRS WRN TN
EARLY THIS MORNING W/MATURE INTENSE TROWAL TO ITS NORTH. WIDESPREAD
MOD-HVY RAIN WAS ONGOING ACRS MUCH OF THE CWA W/HEAVIEST BANDED PCPN
ORIENTED SW-NE THROUGH ACRS THE NW HALF.

COMPLEX/MULTI-FACETED FCST GOING FWD FOR TDA AND TONIGHT. COLD CORE
LOW OVR WRN TN WILL LIFT OUT NEWD THROUGH WRN OH AND DEEPEN THROUGH LT
AFTN IN RESPONSE TO UPSTREAM NRN STREAM TROUGH MAKING QUICK EWD
PROGRESS ACRS THE UPR MIDWEST. IN FACT FULL GAMUT OF 00Z GUIDANCE
TRENDED QUICKER W/RAIN-SNOW CHG OVR AND IN LIFTING THIS DEEP SYS OUT
W/VAPOR INDICATING FTR BEGINNING TO GET PICKED UP W/RAIN CHG TO SNOW
NOW INTO SE MO/SRN IL. HWVR MODEL INTRICACIES ABOUND ESP W/TIMING OF
CHG OVR AND PLACEMENT OF MOST INTENSE PORTION OF MID LVL DEFORMATION
BAND. EARLY CONJECTURE HERE GIVES A NOD TO MODELS THAT IMPLY A
FASTER CHG OVR/WWD PLACEMENT GIVEN NRN STREAM TROUGH IS SLIGHTLY EWD
OF PRIOR 03Z RUC GUIDANCE AND QUICKER W/INFILTRATION OF LL CAA WING
ADVTG SWWD WITHIN RAPIDLY INCREASING LL AGEOSTROPHIC FLW THROUGH MID
MORNING W/CORRESPONDING SUBSEQUENT FASTER ARRIVAL OF COLD POCKET
ALOFT FULLY ANTICIPATED. THIS WILL ESSENTIALLY OVERWHELM TROWAL WARM
NOSE AND LEAD TO RAPID MIX TWD HEAVY SNOW BTWN 17-20Z SW-NE ACRS THE
WRN 2/3RDS OF CWA TIED TO MAXIMIZING VERTICAL ASCENT WITHIN MID LVL
DEFORMATION ZONE ALG NOSE OF ASCENDING WARM CONVEYOR BELT. AND THUS
THE CHALLENGE OF THE DAY IS WHAT TO DO W/SNOW AMOUNTS.

BLENDED MULTI-MODEL QPF WAS UTILIZED TO DAMPEN MUCH HIGHER HIGHRES
GUIDANCE WHILE OFFSETTING LWR BOUND SPECTRAL GUIDANCE. THIS GIVES SIMILAR
AMOUNTS W/HPC YET PREFER A HEDGE WWD PLACEMENT OF MORE SIG SNOW BAND.
THROUGH 05Z...5 INCH AMOUNTS HAVE BEEN REPORTED ACRS WRN TN. HIGHER
AMOUNTS ARE CERTAINLY PLAUSIBLE...EVEN LIKELY...ESP CONSIDERING ALL
HIGHRES SOLUTIONS IMPLYING LOW TOPPED CONVN THIS AFTN WITHIN MID LVL
DEFORMATION ZONE ACRS NRN IN/SRN MI AND SREF PROBS OF 1+ INCH/HR
SNOW RATES EXCEED 70% THIS AFTN AND EVENING AND 2+ PROBS EXCEEDING
30%. NR TERM 06Z RUNS OF HRRR/RUC BOTH CONFIRMING FASTER CHG OVR AND
DVLPMNT OF 40+ DBZ RTNS THIS AFTN WITHIN DEFORMATION ZONE THUS
W/GROWING LIKELIHOOD OF EXTREME SNOWFALL RATES...POTENTIAL ACCUMS
MAY BE SIGNIFICANTLY HIGHER THAN CURRENTLY SHOWN W/SOME EXPERIMENTAL
HIGHRES SNOW ALGORITHMS INDICATING A FOOT PLUS ALG A WARSAW TO
KALAMAZOO LINE. THUS GIVEN TIMING OF CHG OVR WILL LIKELY OCCUR WELL
BFR THE AFTN COMMUTE AND POTENTIAL FOR SHORT DURATION/6+ INCH SNOW
AMOUNTS WILL HOIST A WINTER STORM WATCH FROM EARLY AFTN THROUGH 06Z
FOR GENERALLY THE WRN 2/3RDS OF CWA. FRINGE COUNTIES ALG BOTH SIDES
ARE PROBLEMATIC ESP FAR NW WHERE DVLPMNT OF STG ISOLLABARIC FLW XPCD
THIS AFTN OFF LK MI SHLD MODIFY THE BNDRY LYR SUFFICIENTLY TO
PROMOTE MORE OF A MIX AND NEGLIGIBLE ACCUMS...AND EAST W/SPECTRAL
MODEL CONSENSUS MUCH SLWR LIFTING INTENSE DEFORMATION ZONE BAND OUT
THIS EVENING. THUS THE NOD TWD A WATCH VS WARNING AT THIS POINT AND
IN LIGHT OF CHG OVR TIMING UNCERTAINTIES STILL.

REGARDLESS WHAT IS LEFT OF MID LVL DEFORMATION ZONE...LEFTOVERS
WILL RAPIDLY LIFT OUT/BREAK DOWN TWD LT EVENING/EARLY MORNING W/SNOW
ENDING QUICKLY W-E. CLDS SHLD HOLD THOUGH WITHIN LL THERMAL TROUGH
AND FLW NW LL FLW OFF THE LAKE AND WILL HOLD W/WARMER MIN BLEND
OVERNIGHT.

&&

.LONG TERM...WEDNESDAY THROUGH MONDAY

ONLY MINOR TWEAKS MADE TO THE FCST AS LATEST GUIDANCE IS SIMILAR TO
PREVIOUS GUIDANCE AND INHERITED GRIDS. A REPRIEVE FROM THE WET/WHITE
WX ANTICIPATED WEDNESDAY INTO THURSDAY AS HEIGHT RISES/SHORTWAVE
RIDGING ENSUES BEHIND TODAY`S POWERHOUSE SYSTEM. WEDNESDAY WILL
START OUT MAINLY CLOUDY (ESPECIALLY EAST) AND BREEZY...WITH CLEARING
AND DIMINISHING WINDS BY AFTERNOON. WAA ALOFT WILL BE OFFSET BY
SHALLOW MIXING AND SNOW COVER OVER MUCH OF THE AREA. WITH THIS OPTED
FOR COOLER GUIDANCE EACH DAY.

MORNING WATER VAPOR LOOP SHOWS A POTENT NORTHERN STREAM SHORTWAVE
TROUGH NEAR 145W IN THE NE PAC. THIS FEATURE WILL DIG INTO THE
WESTERN CONUS BY WEDNESDAY...WITH ENSEMBLES CONTINUING TO INDICATE
AN UPPER TROUGH FRACTURE BY THIS TIME. THE MOISTURE STARVED AND
SOMEWHAT SHEARED NRN PIECE OF THIS WAVE LOOKS TO PROPAGATE RAPIDLY
EWD THROUGH THE GREAT LAKES BY THURSDAY NIGHT/FRIDAY MORNING.
ECMWF/GFS 5-3H Q-VECTOR PROGS POINT TO A BRIEF PERIOD OF LARGE SCALE
ASCENT BYPASSING MAINLY TO THE NORTH DURING THIS TIME. AS A
RESULT...NOT EXPECTING MUCH IN THE WAY OF PRECIP BEHIND THE
ATTENDANT CDFNT LOCALLY. OPTED TO LOWER POPS TO SLIGHT CHC FOR THE
POSSIBILITY OF A FEW LGT SNOW SHOWERS.

GREATER AMPLIFICATION OF A NE PAC RIDGE WILL SUPPORT DOWNSTREAM
AMPLIFICATION THIS WEEKEND...ALLOWING ANOTHER POSITIVELY TILTED NRN
STREAM UPPER TROUGH TO DIG INTO THE CENTRAL CONUS. THIS GREATER
AMPLIFICATION WILL HELP FORCE A SRN STREAM LEAD SHORTWAVE NEWD
TOWARDS THE GREAT LAKES BY SATURDAY NIGHT/SUNDAY...BRINGING WITH IT
A BETTER CHC FOR MORE WIDESPREAD PRECIPITATION BY THIS TIME. AS
EXPECTED THIS FAR IN ADVANCE...STILL LOW CONFIDENCE WRT TO DETAILS
(TRACK/TIMING/AMPLITUDE/ETC) SO WILL RETAIN CHC POPS AND FAVOR THE
MORE CONSISTENT ECMWF WHICH HINTS AT A FARTHER NW TRACK AND MAINLY
RAIN LOCALLY. OTHERWISE...TEMPS FOR THE ENTIRE PERIOD ARE FCST TO
GENERALLY BE AT OR BELOW NORMAL.

&&

.AVIATION...
XPC IFR CIGS TO HOLD THROUGH THE PD W/GENERALLY MVFR VSBYS
PREFERRED IN RAIN UNTIL THIS AFTN WHEN CHG OVR TO SNOW OCCURS. PD
OF LIFR CONDS LIKELY LT THIS AFTN/EARLY EVENING IN +SN W/LONGER
DURATION XPCD AT KSBN. WILL ATTEMPT SOME REFINED TIMING W/12Z ISSUANCE.
OTHERWISE GRADIENT WINDS ARE COMING UP NOW W/SFC GUSTS AOA 25KTS
THROUGH EARLY EVENING.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...FLOOD WATCH THROUGH THIS EVENING FOR INZ003>009-012>018-020-
     022>027-032>034.

     WINTER STORM WATCH FROM 1 PM EST /NOON CST/ THIS AFTERNOON
     THROUGH LATE TONIGHT FOR INZ004>009-012>018-020-022>025-032.

MI...FLOOD WATCH THROUGH THIS EVENING FOR MIZ077>081.

     WINTER STORM WATCH FROM 1 PM EST THIS AFTERNOON THROUGH LATE
     TONIGHT FOR MIZ078>081.

OH...FLOOD WATCH THROUGH THIS EVENING FOR OHZ001-002-004-005-015-016-
     024-025.

     WINTER STORM WATCH FROM 1 PM EST THIS AFTERNOON THROUGH LATE
     TONIGHT FOR OHZ001.

LM...GALE WARNING UNTIL 10 AM EST WEDNESDAY FOR LMZ043-046.

&&

$$

SHORT TERM...T
LONG TERM...STEINWEDEL
AVIATION...T









AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 438 AM EST TUE NOV 29 2011

.SYNOPSIS...
AS A COLD FRONT MOVES THROUGH TODAY...RAIN WILL DIMINISH AND
COLDER TEMPERATURES WILL ARRIVE. SNOW SHOWERS ARE POSSIBLE TONIGHT
INTO WEDNESDAY. DRY WEATHER IS SLATED FOR THE LATTER PART OF THE
WEEK UNDER SEASONAL TEMPERATURES.

&&

.NEAR TERM /THROUGH TONIGHT/...
LOW PRESSURE CURRENTLY OVER SOUTHERN OHIO IS PROJECTED TO MOVE TO
THE NORTHEAST DURING THE DAY. ASSOCIATED COLD FRONT CURRENTLY WRAPS
TO THE SOUTHEAST FROM THE LOW...WRAPPING BACK INTO THE CAROLINAS.
RAIN WILL OVERSPREAD THE REGION FROM SOUTH TO NORTH AS THE LOW
APPROACHES...WITH THE HEAVIEST RAINFALL OCCURRING AS THE FRONT MOVES
THROUGH LATE MORNING/EARLY AFTERNOON. TEMPERATURES REMAIN QUITE WARM
IN ADVANCE OF THE FRONT...WITH OVERNIGHT TEMPERATURES WELL ABOVE
CLIMATOLOGICAL HIGH TEMPERATURES FOR LATE NOVEMBER. ALTHOUGH SOME
BRIEF WARMING IS POSSIBLE THIS MORNING...TEMPERATURES WILL FALL
DURING THE DAY AS THE COLD FRONT PASSES. WITH THE LOW EXPECTED TO
TRACK ACROSS EASTERN OHIO UP TO LAKE ERIE...DRY SLOT COULD THEN PASS
THROUGH DURING THE EVENING HOURS...LEAVING EASTERN OHIO AND NORTHERN
WV PANHANDLE DRY FOR A PERIOD OF TIME. HOWEVER...MODELS ARE IN
AGREEMENT THAT ANOTHER PIECE OF ENERGY WILL RIDE UP THE RIDGES
DURING THE EVENING HOURS. TEMPERATURES ACROSS THE RIDGES WILL BE
CRITICAL DURING THIS TIME PERIOD: IF TEMPS DROP LOW ENOUGH...THERE
IS THE POTENTIAL TO DROP A QUICK 1-3 INCHES OF SNOW DURING THIS
PERIOD OF TIME. CURRENT FORECAST ANTICIPATES THAT THIS PRECIP WILL
FALL AS RAIN DURING THE EVENING. AFTER MIDNIGHT...MORE MOISTURE WILL
BEGIN TO MOVE IN FROM THE WEST...ALLOWING FOR SOME SHOWERS TO RETURN
TO THE ENTIRE FORECAST AREA. ALONG THE RIDGES...ABOUT AN INCH OF
SNOW IS EXPECTED AFTER MIDNIGHT. OUTSIDE OF THE RIDGES...A MIX OR
CHANGEOVER TO SNOW CERTAINLY CANNOT BE RULED OUT...BUT TEMPERATURES
ARE EXPECTED TO ONLY DROP TO THE MID 30S OVERNIGHT...LIMITING
ACCUMULATION.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
LOW PRESSURE CENTER SHOULD BE NORTH OF LAKE ONTARIO BY WEDNESDAY
MORNING...AND THE CENTER WILL CONTINUE ITS TREK TO THE NORTHEAST.
WINDS SHOULD BECOME FAVORABLE FOR SOME LAKE EFFECT/UPSLOPE FLOW FOR
SEVERAL HOURS ON WEDNESDAY...AND WITH REMAINS OF DEFORMATION ZONE
MOVING TO THE EAST...HAVE INCREASED POPS ACROSS MOST LOCATIONS
DURING THE DAY. HAVE ALSO BUMPED UP POPS A BIT WEDNESDAY NIGHT FOR
THE RIDGES AS UPSLOPE WINDS SQUEEZE REMAINING MOISTURE OUT. WITH
MUCH COLDER TEMPERATURES WEDNESDAY...REMAINS TO BE SEEN IF SHOWERS
WILL REMAIN SNOW...OR CHANGEOVER TO RAIN. HIGH PRESSURE WILL MOVE
INTO THE REGION BY THURSDAY...ALLOWING FOR DRY CONDITIONS THAT DAY
INTO FRIDAY. ALTHOUGH THERE WILL BE SOME SLIGHT MODERATION IN
TEMPS...HIGHS WILL REMAIN A COUPLE OF DEGREES BELOW NORMAL.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODELS HAVE BEEN CONSISTENT WITH A WEAK COLD FRONT CLIPPING THE
AREA LATE FRIDAY/FRIDAY NIGHT. WITH LIMITED MOISTURE...WILL USE
LOW END CHANCE POPS. DRY AND CHILLY CONDITIONS ARE EXPECTED FOR
SATURDAY...WITH A SMALL CHANCE OF PRECIP COMING IN FOR LATE SUNDAY
AND MONDAY.

&&

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
BLEND OF RECENT SURFACE AND RADAR DATA ALONG WITH HRRR AND NAM MODEL
OUTPUT SHOW COLD FRONTAL BAND OF RAIN MOVING NORTHEASTWARD THROUGH
THE UPPER OHIO VALLEY THROUGH EARLY AFTERNOON.

INITIAL AVIATION CONCERN WILL BE THE WIND. WINDS FROM 2 KFT AGL UP
WILL BE SOUTHEAST AT 40 KTS, WHICH CAN PRODUCE LOW LEVEL WIND SHEAR
AS LONG AS SURFACE WINDS REMAIN LESS THAN 15 KTS. HOWEVER, WITH THE
RAIN BAND ONSET, THE FAST WINDS CAN MIX TO THE SURFACE TO CAUSE
GUSTS OF 25-30 KTS, AS EVIDENCED BY RECENT SURFACE DATA OVER THE
MOUNTAINS, FOR EXAMPLE KEKN, K2G4, KJST, AND KDUJ.

WITHIN THE FRONTAL RAIN BAND, FLIGHT CONDITIONS WILL DETERIORATE TO
MVFR THIS MORNING WITH SHORT-LIVED IFR POSSIBLE IN HEAVIER RAINFALL.

WITH PASSAGE OF THE COLD FRONT TOWARD MIDDAY, SURFACE WINDS WILL
SHIFT INTO THE SOUTHWEST WITH GUSTS TO 20-25 KTS. POST FRONTAL
CONDITIONS THIS AFTERNOON AND TONIGHT WILL BE MAINLY MVFR IN
INTERMITTENT SHOWERS. THERE CAN BE A DRY SLOT WITH VFR CONDITIONS
LATE AFTERNOON INTO EVENING, FOLLOWED BY RENEWED SHOWERS TONIGHT DUE
TO TROWAL DYNAMICS.

SURFACE TEMPERATURES WILL DROP INTO THE 30S, BUT NAM MODEL PROFILES
SUGGEST CLOUDS MAY BE TOO SHALLOW, WEST OF THE MOUNTAINS, TO PRODUCE
A CHANGE TO SNOW SHOWERS AS CLOUD TOP TEMPERATURES CAN BE WARMER
THAN THE M10C NEEDED FOR ICE NUCLEI INITIATION. NEAR THE MOUNTAINS,
CLOUDS CAN BE TALLER AND HENCE HAVE COLDER CLOUD TOPS MAKING SNOW
FORMATION POSSIBLE.

OUTLOOK...WEDNESDAY THROUGH SATURDAY....
CONTINUED POST SYSTEM WRAP-AROUND SHOWERS MAY CAUSE ADDITIONAL
PERIODS OF MAINLY MVFR RESTRICTIONS INTO WEDNESDAY NIGHT.  THEN
MAINLY VFR UNDER HIGH PRESSURE THURSDAY INTO SATURDAY. ALBEIT THERE
IS A SMALL CHANCE OF SHOWERS WITH RESTRICTIONS NORTH FROM A PASSING
GREAT LAKES COLD FRONT FRIDAY NIGHT.

&&

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

&&

$$







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 318 AM EST TUE NOV 29 2011

.SYNOPSIS...
AS A COLD FRONT MOVES THROUGH TODAY...RAIN WILL DIMINISH AND
COLDER TEMPERATURES WILL ARRIVE. SNOW SHOWERS ARE POSSIBLE TONIGHT
INTO WEDNESDAY. DRY WEATHER IS SLATED FOR THE LATTER PART OF THE
WEEK UNDER SEASONAL TEMPERATURES.

&&

.NEAR TERM /THROUGH TONIGHT/...
LOW PRESSURE CURRENTLY OVER SOUTHERN OHIO IS PROJECTED TO MOVE TO
THE NORTHEAST DURING THE DAY. ASSOCIATED COLD FRONT CURRENTLY WRAPS
TO THE SOUTHEAST FROM THE LOW...WRAPPING BACK INTO THE CAROLINAS.
RAIN WILL OVERSPREAD THE REGION FROM SOUTH TO NORTH AS THE LOW
APPROACHES...WITH THE HEAVIEST RAINFALL OCCURRING AS THE FRONT MOVES
THROUGH LATE MORNING/EARLY AFTERNOON. TEMPERATURES REMAIN QUITE WARM
IN ADVANCE OF THE FRONT...WITH OVERNIGHT TEMPERATURES WELL ABOVE
CLIMATOLOGICAL HIGH TEMPERATURES FOR LATE NOVEMBER. ALTHOUGH SOME
BRIEF WARMING IS POSSIBLE THIS MORNING...TEMPERATURES WILL FALL
DURING THE DAY AS THE COLD FRONT PASSES. WITH THE LOW EXPECTED TO
TRACK ACROSS EASTERN OHIO UP TO LAKE ERIE...DRY SLOT COULD THEN PASS
THROUGH DURING THE EVENING HOURS...LEAVING EASTERN OHIO AND NORTHERN
WV PANHANDLE DRY FOR A PERIOD OF TIME. HOWEVER...MODELS ARE IN
AGREEMENT THAT ANOTHER PIECE OF ENERGY WILL RIDE UP THE RIDGES
DURING THE EVENING HOURS. TEMPERATURES ACROSS THE RIDGES WILL BE
CRITICAL DURING THIS TIME PERIOD: IF TEMPS DROP LOW ENOUGH...THERE
IS THE POTENTIAL TO DROP A QUICK 1-3 INCHES OF SNOW DURING THIS
PERIOD OF TIME. CURRENT FORECAST ANTICIPATES THAT THIS PRECIP WILL
FALL AS RAIN DURING THE EVENING. AFTER MIDNIGHT...MORE MOISTURE WILL
BEGIN TO MOVE IN FROM THE WEST...ALLOWING FOR SOME SHOWERS TO RETURN
TO THE ENTIRE FORECAST AREA. ALONG THE RIDGES...ABOUT AN INCH OF
SNOW IS EXPECTED AFTER MIDNIGHT. OUTSIDE OF THE RIDGES...A MIX OR
CHANGEOVER TO SNOW CERTAINLY CANNOT BE RULED OUT...BUT TEMPERATURES
ARE EXPECTED TO ONLY DROP TO THE MID 30S OVERNIGHT...LIMITING
ACCUMULATION.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
LOW PRESSURE CENTER SHOULD BE NORTH OF LAKE ONTARIO BY WEDNESDAY
MORNING...AND THE CENTER WILL CONTINUE ITS TREK TO THE NORTHEAST.
WINDS SHOULD BECOME FAVORABLE FOR SOME LAKE EFFECT/UPSLOPE FLOW FOR
SEVERAL HOURS ON WEDNESDAY...AND WITH REMAINS OF DEFORMATION ZONE
MOVING TO THE EAST...HAVE INCREASED POPS ACROSS MOST LOCATIONS
DURING THE DAY. HAVE ALSO BUMPED UP POPS A BIT WEDNESDAY NIGHT FOR
THE RIDGES AS UPSLOPE WINDS SQUEEZE REMAINING MOISTURE OUT. WITH
MUCH COLDER TEMPERATURES WEDNESDAY...REMAINS TO BE SEEN IF SHOWERS
WILL REMAIN SNOW...OR CHANGEOVER TO RAIN. HIGH PRESSURE WILL MOVE
INTO THE REGION BY THURSDAY...ALLOWING FOR DRY CONDITIONS THAT DAY
INTO FRIDAY. ALTHOUGH THERE WILL BE SOME SLIGHT MODERATION IN
TEMPS...HIGHS WILL REMAIN A COUPLE OF DEGREES BELOW NORMAL.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODELS HAVE BEEN CONSISTENT WITH A WEAK COLD FRONT CLIPPING THE
AREA LATE FRIDAY/FRIDAY NIGHT. WITH LIMITED MOISTURE...WILL USE
LOW END CHANCE POPS. DRY AND CHILLY CONDITIONS ARE EXPECTED FOR
SATURDAY...WITH A SMALL CHANCE OF PRECIP COMING IN FOR LATE SUNDAY
AND MONDAY.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
BLEND OF RECENT SURFACE AND RADAR DATA ALONG WITH HRRR AND NAM MODEL
OUTPUT SHOW COLD FRONTAL BAND OF RAIN MOVING NORTHEASTWARD THROUGH
THE UPPER OHIO VALLEY THIS MORNING INTO EARLY AFTERNOON.

INITIAL AVIATION CONCERN WILL BE THE WIND. SURFACE WINDS WILL BE
EAST NEAR 10 KTS, WHILE WINDS FROM 2 KFT AGL UP WILL BE SOUTHEAST AT
40 KTS, WHICH CAN PRODUCE LOW LEVEL WIND SHEAR. JUST PRIOR TO THE
RAIN BAND ONSET, THE FAST WINDS CAN MIX TO THE SURFACE TO CAUSE
GUSTS OF 25-30 KTS, AS EVIDENCED BY RECENT SURFACE DATA OVER THE
MOUNTAINS.

WITHIN THE FRONTAL RAIN BAND, FLIGHT CONDITIONS WILL DETERIORATE TO
MVFR WITH SHORT-LIVED IFR POSSIBLE IN HEAVIER RAINFALL.

WITH PASSAGE OF THE COLD FRONT, SURFACE WINDS WILL SHIFT INTO THE
SOUTHWEST WITH GUSTS TO 20-25 KTS. POST FRONTAL CONDITIONS THIS
AFTERNOON AND TONIGHT WILL BE MAINLY MVFR IN INTERMITTENT SHOWERS.
THERE CAN BE A DRY SLOT WITH VFR CONDITIONS LATE AFTERNOON INTO
EVENING, FOLLOWED BY RENEWED SHOWERS TONIGHT DUE TO WRAP AROUND
DYNAMICS.

SURFACE TEMPERATURES WILL DROP INTO THE 30S, BUT NAM MODEL PROFILES
SUGGEST CLOUDS MAY BE TOO SHALLOW TO PRODUCE A CHANGE TO SNOW
SHOWERS AS CLOUD TOP TEMPERATURES CAN BE WARMER THAN THE M10C NEEDED
FOR ICE NUCLEI INITIATION.

OUTLOOK...WEDNESDAY THROUGH SATURDAY....
CONTINUED POST SYSTEM WRAP AROUND SHOWERS MAY CAUSE ADDITIONAL
PERIODS OF MAINLY MVFR RESTRICTIONS INTO WEDNESDAY NIGHT. THEN
MAINLY VFR UNDER HIGH PRESSURE THURSDAY INTO SATURDAY. ALBEIT
THERE IS A SMALL CHANCE OF SHOWERS WITH RESTRICTIONS NORTH FROM A
PASSING GREAT LAKES COLD FRONT FRIDAY NIGHT.

&&

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

&&

$$







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 101 AM EST TUE NOV 29 2011

.SYNOPSIS...
A SLOW MOVING LOW PRESSURE SYSTEM WILL BRING OCCASIONAL RAIN
THROUGH TUESDAY. COOLER WEATHER IN ITS WAKE WILL TURN RAIN
SHOWERS TO SNOW SHOWERS BY WEDNESDAY. DRY WEATHER IS SLATED FOR
THE LATTER PART OF THE WEEK UNDER SEASONAL TEMPERATURES.

&&

.NEAR TERM /THROUGH TODAY/...
06Z UPDATE: SOME MINOR TWEAKS MADE TO PREVIOUS FORECAST. PRIMARY
CHANGE WAS TO BUMP UP POPS ACROSS EASTERN OHIO WHERE STEADIEST
RAIN IS OCCURRING...AND TO TIGHTEN GRADIENT ALONG NORTHEASTERN
SHIELD OF PRECIP ACROSS NORTHWESTERN PA WHERE LITTLE RAIN HAS
FALLEN SO FAR. ALSO BUMPED UP WIND GUSTS ALONG THE RIDGES WHERE
SOUTHEAST WINDS ARE FAVORABLE FOR DOWNSLOPING. THERE HAVE BEEN A
FEW GUSTS TO 25-30 KTS ACROSS WV/MD RIDGES...AND EXPECT THAT THIS
SHOULD MAKE SOME NORTHWARD PROGRESS OVERNIGHT.

03Z UPDATE: NO BIG CHANGES TO THE ONGOING FORECAST. DRY WEATHER
CONTINUES FOR A FEW MORE HOURS OVER WRN PA AND NRN WV. WITH THE
WINDS PICKING UP...SO HAVE THE TEMPS. MGW HAS CLIMBED INTO THE MID
60S...WHILE OTHER LOCATIONS IN THE FAVORED DOWNSLOPE AREAS HAVE
ALSO ROSE. TWEAKED TEMPS TO ACCOUNT FOR LATEST TRENDS...OTHERWISE
PREVIOUS DISCUSSION FOLLOWS.

.PREVIOUS DISCUSSION...
HIGHEST CONFIDENCE FORECAST RESIDES IN EAST CENTRAL
OHIO WHERE STEADY LIGHT RAIN SHALL PERSIST THROUGH THE BALANCE OF
THE NIGHT. DUE NOT FORESEE MUCH CHANGE IN TEMPERATURES OVERNIGHT
DUE TO THE CLOUDS AND INCREASING WIND.

A SHORT PERIOD /3-6HRS/ OF LIGHT TO MODERATE RAINFALL SHALL OCCUR
FROM AFTER DAWN TUESDAY S OF THE MASON DIXON LINE TO MID AFTERNOON
ACROSS I-80 COMMUNITIES.  TOTAL RAINFALL AMOUNTS ARE PROJECTED TO BE
AROUND 3/4" OF AN INCH...SAVE FOR ZZV AREA AND EASTERN PORTIONS OF
GARRETT AND TUCKER WHERE VALUES COULD BE A TENTH OR TWO HIGHER.

WINDS WILL PICK UP FROM THE SE TONIGHT OVER THE RIDGES S AND E OF
PIT.  GUSTS COULD ECLIPSE 30 MPH.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
SHOWERS WILL DECREASE IN COVERAGE TUESDAY NIGHT BECOMING SCATTERED
BY WEDNESDAY.  FORECAST POSITION OF OCCLUDED SURFACE FRONT...TRACK
OF LOW PRESSURE...AND MID LEVEL DRY PUNCH SHOULD LIMIT RAINFALL
AMOUNTS.  AS THE UPPER LOW MOVES NORTHEAST...MUCH COLDER AIR WILL
ARRIVE WITH PTYPE CHANGING TO SNOW FOR MOST LOCATIONS WEDNESDAY. DO
NOT EXPECT SIGNIFICANT ACCUMULATION...WITH PERHAPS AN INCH OR SO ON
THE RIDGES AND ALONG THE I-80 CORRIDOR.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGH PRESSURE MOVES IN FOR THURSDAY AND WILL BRING DRY BUT CHILLY
CONDITIONS. MODELS HAVE BEEN CONSISTENT WITH A WEAK COLD FRONT
CLIPPING THE AREA LATE FRIDAY/FRIDAY NIGHT. WITH LIMITED
MOISTURE...WILL USE LOW END CHANCE POPS. DRY AND CHILLY CONDITIONS
ARE EXPECTED FOR SATURDAY...WITH A SMALL CHANCE OF PRECIP COMING
IN FOR LATE SUNDAY AND MONDAY.

&&

.AVIATION /06Z TUESDAY THROUGH FRIDAY/...
BLEND OF RECENT SURFACE AND RADAR DATA ALONG WITH HRRR AND NAM MODEL
OUTPUT SHOW COLD FRONTAL BAND OF RAIN MOVING NORTHEASTWARD THROUGH
THE UPPER OHIO VALLEY THIS MORNING INTO EARLY AFTERNOON.

INITIAL AVIATION CONCERN WILL BE THE WIND. SURFACE WINDS WILL BE
EAST NEAR 10 KTS, WHILE WINDS FROM 2 KFT AGL UP WILL BE SOUTHEAST AT
40 KTS, WHICH CAN PRODUCE LOW LEVEL WIND SHEAR. JUST PRIOR TO THE
RAIN BAND ONSET, THE FAST WINDS CAN MIX TO THE SURFACE TO CAUSE
GUSTS OF 25-30 KTS, AS EVIDENCED BY RECENT SURFACE DATA OVER THE
MOUNTAINS.

WITHIN THE FRONTAL RAIN BAND, FLIGHT CONDITIONS WILL DETERIORATE TO
MVFR WITH SHORT-LIVED IFR POSSIBLE IN HEAVIER RAINFALL.

WITH PASSAGE OF THE COLD FRONT, SURFACE WINDS WILL SHIFT INTO THE
SOUTHWEST WITH GUSTS TO 20-25 KTS. POST FRONTAL CONDITIONS THIS
AFTERNOON AND TONIGHT WILL BE MAINLY MVFR IN INTERMITTENT SHOWERS.
THERE CAN BE A DRY SLOT WITH VFR CONDITIONS LATE AFTERNOON INTO
EVENING, FOLLOWED BY RENEWED SHOWERS TONIGHT DUE TO WRAP AROUND
DYNAMICS.

SURFACE TEMPERATURES WILL DROP INTO THE 30S, BUT NAM MODEL PROFILES
SUGGEST CLOUDS MAY BE TOO SHALLOW TO PRODUCE A CHANGE TO SNOW
SHOWERS AS CLOUD TOP TEMPERATURES CAN BE WARMER THAN THE M10C NEEDED
FOR ICE NUCLEI INITIATION.

OUTLOOK...WEDNESDAY THROUGH SATURDAY....
CONTINUED POST SYSTEM WRAP AROUND SHOWERS MAY CAUSE ADDITIONAL
PERIODS OF MAINLY MVFR RESTRICTIONS INTO WEDNESDAY NIGHT. THEN
MAINLY VFR UNDER HIGH PRESSURE THURSDAY INTO SATURDAY. ALBEIT
THERE IS A SMALL CHANCE OF SHOWERS WITH RESTRICTIONS NORTH FROM A
PASSING GREAT LAKES COLD FRONT FRIDAY NIGHT.

&&

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

&&

$$







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 1220 AM EST TUE NOV 29 2011

UPDATED AVIATION DISCUSSION FOR 06Z TAFS

.SYNOPSIS...

WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW PROGRESSIVE FLOW ACROSS
SRN CANADA...FEATURING A WEAK RIDGE OVER SW CANADA...A SHORTWAVE
TROF OVER MANITOBA AND ANOTHER SHORTWAVE OVER QUEBEC. A CUTOFF LOW
IS OVER THE LWR MISSISSIPPI VALLEY. INCREASING SW FLOW AHEAD OF THE
MANITOBA SHORTWAVE HAS SCOURED OUT LOW CLOUDS ACROSS MOST OF THE
FCST AREA WITH DOWNSLOPING NEAR LAKE SUPERIOR AIDING THE CLEARING
TREND. AS OF 2030Z...LAST OF THE LOW CLOUDS ARE DOWNWIND OF LAKE
MICHIGAN...E OF KESC-GRAND MARAIS LINE. APPROACHING COLD FRONT
ASSOCIATED WITH MANITOBA SHORTWAVE IS NOT ACCOMPANIED BY ANY PCPN S
OF THE INTERNATIONAL BORDER AS AIRMASS IS DRY PER 12Z SOUNDINGS. &&

.SHORT TERM /TONIGHT AND TUE/...

SHORT TERM WILL BE GENERALLY QUIET AS OVERALL DRY AIRMASS LIMITS ANY
PCPN POTENTIAL DESPITE PASSAGE OF SHORTWAVE. COLD FRONT ASSOCIATED
WITH SHORTWAVE MOVING ACROSS ONTARIO TONIGHT WILL BRING A WIND SHIFT
AND USHER IN A PERIOD OF DECENT CAA (850MB TEMPS FALL FROM 0 TO 2C
THIS EVENING TO -6 TO -8C BY 12Z TUE). SHOULD BEGIN TO SEE AN
INCREASE IN LAKE EFFECT CLOUDS OVERNIGHT AS OVERWATER INSTABILITY
IMPROVES. OTHERWISE...NO PCPN IS EXPECTED AS AIRMASS IS DRY.

ON TUE...BRISK N WINDS AND MORE THAN ADEQUATE OVERWATER INSTABILITY
WILL LEAD TO QUITE A BIT OF STRATOCU OFF LAKE SUPERIOR. ALTHOUGH
850MB TEMPS ARE MARGINALLY COLD TO SUPPORT FLURRIES/-SHSN OFF THE
LAKE...TEMPS IN THE SHALLOW MOIST LAYER ARE JUST ABOVE -10C. IF
ANYTHING...THERE MIGHT BE SOME -FZDZ...BUT SUBCLOUD LAYER ON FCST
SOUNDINGS LOOKS TOO DRY TO SUPPORT THAT. THE LACK OF LOW CLOUDS WELL
UPSTREAM SUPPORTS MODEL FCST OF SOMEWHAT DRIER LOWER BOUNDARY LAYER.
IF THERE SOMEHOW IS A LITTLE PCPN TUE...IT WOULD PROBABLY BE OVER
NCNTRL UPPER MI (ERN BARAGA/MARQUETTE/WRN ALGER) DUE TO
PRECONDITIONING/STREAMLINE OFF LAKE NIPIGON INTO THAT AREA. IT WILL
BE A SEASONABLY CHILLY DAY WITH HIGHS IN THE UPPER 20S TO MID 30S.

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...

TUESDAY NIGHT THROUGH WEDNESDAY EVENING...
WITH THE CONTINUED NORTHEASTWARD EJECTION OF
THE CUT OFF LOW OVER THE OHIO VALLEY AT 00Z WEDNESDAY TO THE LOWER
GREAT LAKES BY DAYBREAK WEDNESDAY...AND ACROSS QUEBEC THEREAFTER.
THE RESULT FOR THE UPPER GREAT LAKES WILL BE A 500MB RIDGE
OVERHEAD...AND A RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE AREA
FROM TX. SENSIBLE WEATHER WISE...EXPECT DRY CONDITIONS WITH WARMING
ALOFT FROM A CWA AVERAGE -4 TO -1C AT 850MB DURING THE PERIOD.

THURSDAY MORNING THROUGH FRIDAY MORNING...
THE NEXT FEATURE OF INTEREST WILL BE SLIDING ACROSS EASTERN MT
WEDNESDAY MORNING...AND BETTER ORGANIZING FROM ND TO EASTERN CO BY
18Z WEDNESDAY. THE FEATURE WILL THEN WEAKEN AS IT SETS UP FROM UPPER
MI THROUGH TX BY 18Z THURSDAY. WITH THE ASSISTANCE OF SOME MID LEVEL
SUPPORT ON THE NORTHERN EDGE OF THIS FEATURE /500MB TROUGH EXTENDING
SW FROM THE NORTHERN PORTIONS OF HUDSON BAY/ LIGHT PRECIPITATION
WILL BE POSSIBLE...MAINLY BEHIND THE SFC LOW. NORTHERLY FLOW AND
850MB TEMPS OF -7 TO -9C BY 18Z THURSDAY SHOULD BRING ABOUT LIGHT
SNOW SHOWERS. INDICATIONS CONTINUE TO POINT AT 1 TO 3 INCHES OF SNOW
THURSDAY ACROSS THE KEWEENAW PENINSULA...WITH VALUES REMAINING BELOW
ADVISORY HEADLINE CRITERIA AT THIS TIME. COOLER NW FLOW WILL THEN
DOMINATE THURSDAY NIGHT WITH 850MB TEMPS BOTTOMING OUT AROUND -13C
BY 12Z FRIDAY...WHILE THE 500MB AXIS AND SFC FRONT EXIT TO OUR
EAST...LIMITING SIGNIFICANT SNOWFALL ACCUMULATIONS.

FRIDAY AFTERNOON AND EVENING...
WAA WILL QUICKLY TAKE HOLD FRIDAY AFTERNOON THROUGH THE EVENING
HOURS WITH 850MB TEMPS REBOUNDING TO AROUND -1 TO -4C DEPENDING ON
WHAT MODEL YOU BELIEVE...AND A WEAK RIDGE SLIDING ACROSS ALOFT.
EITHER WAY IT SHOULD BE DRY WITH SW WINDS...WITH THE LAST OF THE
LAKE EFFECT/LAKE ENHANCED PRECIP ENDING AT 12Z FRIDAY ON MAINLY
WESTERLY WINDS.

BEYOND FRIDAY EVENING THE FORECAST BEGINS TO BECOME A LITTLE LESS
PREDICTABLE. A 500MB TROUGH SET UP FROM N CENTRAL CANADA THROUGH MT
AT 18Z FRIDAY WILL ATTEMPT TO PUSH A SOUTHWESTERN U.S. CUT OFF LOW
INTO THE MAIN FLOW OVER THE WEEKEND...WITH THE ELONGATED TROUGH
SLIDING OVER THE UPPER GREAT LAKES SOMETIME BETWEEN SATURDAY MORNING
AND SUNDAY AFTERNOON...WITH AN ADDITIONAL WAVE ALMOST RIGHT BEHIND
THE PRIMARY WAVE FOR SUNDAY AFTERNOON OR MONDAY AFTERNOON.
YES...THERE IS NEARLY A 24 HOUR DIFFERENCE BETWEEN THE 28/00Z RUN OF
THE ECMWF AND THE 28/00Z AND 06Z RUNS OF THE GFS. THE 12Z RUNS OF
THE GFS AND ECMWF HAVE COME INTO A LITTLE BETTER AGREEMENT ONCE
AGAIN...AND WE WILL HAVE TO WAIT AND SEE IF THIS TREND CONTINUES.
&&

.AVIATION /FOR THE 06Z TAF ISSUANCE/...

EXPECT MVFR CONDITIONS TO PREVAIL THRU MUCH OF THE FCST PD AS LAKE
CLOUDS WILL MOVE IN TONIGHT BEHIND A COLD FRONT. INITIALLY...WARMER
AIR BEHIND THE FRONT MAY LIMIT LAKE CLOUD FORMATION FOR THE EARLY
OVERNIGHT...BUT AS AIRMASS BECOMES COLDER AND OVERWATER INSTABILITY
INCREASES...EXPECT STRATOCU/MVFR CIGS TO DEVELOP OFF LAKE SUPERIOR
AND AFFECT KIWD/KCMX/KSAW THROUGH MUCH OF THE DAY ON TUESDAY.
&&

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

TYPICAL CHANGEABLE LATE FALL PATTERN EXPECTED THIS WEEK. COLD FRONT
WILL PASS ACROSS THE AREA TONIGHT. MAY SEE A FEW GALE FORCE GUSTS
BTWN ISLE ROYALE AND THE KEWEENAW LATE THIS AFTN IN THE SW FLOW
AHEAD OF THE FRONT. BEHIND THE FRONT IN DECENT CAA REGIME...THERE
MAY BE SOME NORTHERLY GALE FORCE GUSTS FROM NCNTRL TO SCNTRL LAKE
SUPERIOR OVERNIGHT/EARLY TUE AS OVERWATER INSTABILITY INCREASES. AT
THIS TIME...IT APPEARS GALE GUSTS SHOULDN`T BE WIDESRPEAD OR
PERSISTENT ENOUGH TO WARRANT A GALE WARNING. WINDS WILL SLOWLY
DIMINISH FROM W TO E TUE AFTN/NIGHT AS HIGH PRES RIDGE MOVES CLOSER
TO THE AREA. LIGHTER WINDS UNDER 20KT WILL BE THE RULE WED
AFTN/NIGHT UNDER WEAK PRES GRADIENT ASSOCIATED SFC TROF SETTLING SE
INTO THE UPPER LAKES. N TO NW WINDS WILL INCREASE INTO THE 15-25KT
RANGE THU/THU NIGHT AS THE TROF SLIPS SE OF THE AREA. AFTER A BRIEF
PERIOD OF LIGHTER WINDS LATE THU NIGHT/FRI MORNING...WINDS WILL
AGAIN BE ON THE INCREASE LATER FRI INTO SAT AHEAD OF THE NEXT LOW
PRES TROF APPROACHING FROM THE NW. MAY SEE GALES IN THE SW FLOW
AHEAD OF THE TROF.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
  GALE WARNING FROM 7 AM TO 7 PM EST TUESDAY FOR LMZ221-250.

&&

$$

SYNOPSIS...ROLFSON
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JV
MARINE...ROLFSON






AREA FORECAST DISCUSSION...UPDATED AVIATION

NWS ST LOUIS MO

 1152 PM CST MON NOV 28 2011

.UPDATE...
/926 PM CST MON NOV 28 2011/

RADAR TRENDS ARE SHOWING SOME INCREASE CURRENTLY OVER THE EASTERN
OZARKS. DO NOT EXPECT ADDITIONAL AMOUNTS OF SNOW AND SLEET TO BE
MUCH MORE THAN A HALF INCH AS VISIBILITIES AT OBSERVATION SITES
ARE NOT DROPPING MUCH AND THERE IS NO SIGNIFICANT COOLING ON IR
IMAGERY. RUC AND OTHER MODELS SOUNDINGS ARE SHOWING SOME WEAK
WARMING THROUGH A DEEP LAYER THE REST OF THE NIGHT AT THE SAME
TIME ASCENT WILL WEAKEN. TOTAL SNOW AND SLEET AMOUNTS IN THE FAR
SOUTHERN CWA STILL LOOK LIKE THEY WILL BE 1 TO 2 INCHES WITH
AMOUNTS DROPPING OFF QUICKLY TO THE NORTH. REST OF THE FORECAST
STILL LOOK GOOD.

BRITT

&&

.DISCUSSION...
/341 PM CST MON NOV 28 2011/

UPPER LOW CUT OFF LATE LAST NIGHT OVER SE AR AND DURING THE DAY
TODAY SYSTEM HAS BEGUN TO PIVOT TO THE NORTHEAST...PERHAPS JUST A
BIT FURTHER E THAN FORECAST BY EARLIER NWP OUTPUT.  NO QUESTION THAT
THIS SYSTEM WILL BRING PRECIPITATION TO SE SECTIONS OF THE CWA
OVER THE NEXT 24 HOURS...AS LATEST MODEL RUNS CONTINUE TO SUPPORT
EARLIER THINKING THAT VERY MOIST AIRMASS WILL BE UNDERGOING STRONG
ISENTROPIC ASCENT AS IT WRAPS AROUND THE NORTH SIDE OF THE LOW FROM
THE OHIO VALLEY INTO SE MO.  ISENTROPIC PROGS INDICATE THAT THERE
WILL BE AN EXTREMELY TIGHT POP GRADIENT/SHARP CUTOFF IN PRECIP ON
THE WESTERN EDGE OF THE PRECIP SHIELD...AND FOR NOW WE`RE HOLDING
ONTO THE THINKING THAT THIS EDGE WILL BE JUST EAST OF A IJX-VIH
LINE.  ANY SMALL WOBBLE IN THE TRACK OF THE SYSTEM MAY CAUSE A
FAIRLY BIG ADJUSTMENT TO THE POPS IN THIS CORRIDOR.

BIGGEST CONCERN FOR AREA IS PTYPE...AND 12Z UA DATA INDICATED AMS
LOCKED TO THE WEST OF THE SYSTEM WAS JUST A BIT COOLER THAN
SUGGESTED BY EARLIER RUNS. THERE COULD BE A MIX OF PTYPES EARLY
THIS EVENING WITH THE INITIAL ONSET OF THE PRECIP...BUT THE
INTENSE NATURE OF THE PROGGED WAA ACROSS AREA CERTAINLY SUGGESTS
THAT WARM AIR WILL OVERWHELM COLUMN AND AS A RESULT MOST OF THE
PRECIP FROM MID EVENING ON WILL FALL IN THE FORM OF RAIN. THE
EXCEPTION TO THIS IS THE E OZARKS...WHERE FORECAST SOUNDINGS DO
INDICATE THAT POCKET OF LOW LEVEL COLD AIR IS GOING TO STUBBORNLY
HOLD ON. IN THIS AREA...PRIMARILY ALONG AND SOUTH OF A STE
GENEVIEVE...POTOSI LINE...HAVE CONTINUED TO A MENTION OF SNOW AND
SLEET ALONG WITH THE RAIN THROUGHOUT THE NIGHT. ANY ACCUMULATIONS
SHOULD BE MINOR BUT CERTAINLY NOT OUT OF THE QUESTION...ESPECIALLY
IF DYNAMIC COOLING CAN DROP TEMPS ENOUGH IN A LOCALIZED AREA.

PRECIP WINDS DOWN FROM EASTERN MO INTO S CENTRAL IL DURING THE DAY
ON TUE...WITH THE BULK OF THE PRECIP EAST OF THE MISSISSIPPI RIVER
BY MIDDAY.  THE DECREASE OF THE WAA AS THE SYSTEM PUSHES INTO THE
LOWER GREAT LAKES DOES ALLOW AMS OVER AREA TO BEGIN TO COOL ONCE
AGAIN...BUT FOR THE MOST PART IT LOOKS LIKE PRECIP WILL BE SHUTTING
DOWN BY THE TIME THERMAL PROFILES WOULD SUPPORT A MIX AND/OR A
CHANGEOVER TO ALL SNOW.  SO...OTHER THAN CONTINUING A MENTION OF
SOME LINGERING LIGHT SNOW IN THE AFOREMENTIONED POCKET OF COOL AIR
OVER THE OZARKS...HAVE MAINTAINED ALL RAIN IN THE FORECASTS FOR TUE.

TRANQUIL WEATHER WILL RETURN FOR MID WEEK WITH TEMPS REBOUNDING TO
NEAR OR JUST ABOVE THE 50 DEGREE MARK OVER S MO ON
THURSDAY...ALTHOUGH A DRY COLD FRONTAL PASSAGE SHOULD KNOCK DAYTIME
TEMPS BACK INTO THE 30S AND 40S BY FRIDAY.

NEXT SYSTEM SHOULD BEGIN TO PUSH OUT OF THE WESTERN U.S. AND INTO
THE PLAINS LATE SATURDAY-SUNDAY TIME FRAME...WITH PRECIP RETURNING
TO THE AREA DURING THIS TIME.  SOME QUESTION AS TO WHAT THE PTYPE
MAY BE...BUT FOR NOW HAVE GONE WITH A BROAD-BRUSH RAIN/SNOW MIX AND
WILL FINE-TUNE AS WE GET CLOSER TO EVENT.

GKS/TRUETT

&&

.AVIATION...
/1121 PM CST MON NOV 28 2011/

MVFR CIGS HAVE FINALLY ERODED OVER KCOU/KUIN AND VFR CONDITIONS
ARE EXPECTED AT THOSE SITES FOR THE REST OF THE NIGHT. WINDS WILL
GRADUALLY INCREASE TONIGHT AS THE PRESSURE GRADIENT TIGHTENS
BETWEEN A DEPARTING LOW PRESSURE SYSTEM OVER THE OHIO VALLEY AND
AN APPROACHING SURFACE RIDGE AXIS.

SPECIFICS FOR KSTL AND KSUS...KSTL/KSUS REMAIN ON THE WRN FRINGE
OF A SHARP PCPN GRADIENT AND PDS OF LGT RAIN SHOULD CONTINUE
THROUGH MOST OF THE NIGHT. MVFR CIGS WILL PERSIST THROUGH MOST OF
THE DAY WITH RAPID IMPROVEMENT BY LATE AFTN AS THE LOW PRESSURE
SYSTEM LIFTS AWAY FROM THE REGION. WINDS WILL GRADUALLY INCREASE
OVERNIGHT AS THE PRESSURE GRADIENT TIGHTENS.

KANOFSKY

&&

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

$$

WFO LSX







AREA FORECAST DISCUSSION

NWS WILMINGTON NC

 405 AM EST TUE NOV 29 2011

.SYNOPSIS...
COOLER AND DRIER AIR WILL BE USHERED IN FROM THE WEST TODAY. HIGH
PRESSURE WILL BUILD ACROSS THE EASTERN CAROLINAS FOR THE REMAINDER
OF THE WEEK. THIS HIGH WILL SHIFT OFF THE NORTHEAST COAST OVER THE
WEEKEND POSSIBLY ALLOWING FOR A SLIGHT MODERATION BACK TOWARDS
SEASONABLE TEMPERATURES.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 330 AM EST TUESDAY...LEADING EDGE OF THE LINE OF CONVECTION
HAS PUSHED ENTIRELY THROUGH THE ILM CWA. ITS POTENTIAL TO PRODUCE
SEVERE WEATHER HAS DIMINISHED CONSIDERABLY. RIGHT NOW...IT CONTINUES
TO PRODUCE DRAMATIC WIND SHIFTS WITH CAA IMMEDIATELY BEHIND IT. POST
FRONTAL RAINS WILL BE THE MAINSTAY THIS MORNING. A NARROW BAND OF
DEEP MOISTURE FROM THE SUBTROPICS/TROPICS WILL KEEP THE POST FRONTAL
RAINS ONGOING INTO DAYLIGHT TUESDAY. UNUSUAL FOR POSTFRONTAL
RAINS...ESPECIALLY WITH PROGGED WIDESPREAD AMOUNTS IN THE ONE
QUARTER TO ONE HALF INCH...ALONG WITH ISOLATED 2+ INCHES. THE HIGHER
AMOUNT HAS ALREADY OCCURRED IN A 15 MILE WIND SWATH BETWEEN
JOHNSONVILLE OF SE FLORENCE COUNTY NORTHWARD ACROSS CENTRAL  MARION
COUNTY TO MINTURN OF WESTERN DILLON COUNTY. PER LATEST HRRR MODEL
RUNS...THE TREND HAS BEEN ENDING THE PCPN BY MID MORNING ILM SC
COUNTIES TO LATE MORNING ACROSS THE ILM NC COUNTIES.

THE UPPER CLOSED LOW WILL BE LIFTING NE ALONG THE BACKBONE OF THE
APPALACHIANS THROUGHOUT THE NEAR TERM...REACHING THE EASTERN GREAT
LAKES WED MORNING. THERE IS ONE MID LEVEL VORTICITY LOBE SPIRALING
AROUND THE UPPER CLOSED LOW...WHICH AFFECTS THE FAR NW PORTIONS OF
THE ILM CWA WITH PVA DURING THIS AFTERNOON. SOME OF THE DEEPER
MOISTURE ROTATING AROUND THE UPPER LOW DOES MOVE ACROSS THE ILM CWA
AT THE SAME TIME THIS VORT DOES. WILL INCLUDE LOW CHANCE FOR POPS TO
ACCOMMODATE. WILL KEEP IT AS LIQUID RAINSHOWERS EVENTHOUGH 850MB
TEMPS ARE PROGGED TO DROP TO -2 ACROSS THIS AREA...HOWEVER THE
1000-850MB THICKNESSES ARE STILL PROGGED ABOVE 1300 THE USUAL
THICKNESS TO SEE FROZEN PCPN. FOR MAX/MIN TEMPS OPTED TO USE THE
LOWER END OF GUIDANCE DUE TO CAA ALREADY OCCURRING. WITH EXCELLENT
LOW LEVEL LAPSE RATES ESPECIALLY DURING THE INSOLATION PART OF THE
DAY...BROKEN TO OVERCAST STRATOCU WILL OVERSPREAD THE ILM CWA.

&&


.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...COOL AND DRY WEATHER IS ON TAP FOR THE DURATION
OF THE SHORT TERM PERIOD. CUTOFF UPPER LOW WILL BE QUICKLY EXITING
TO THE NE ACRS NY AND INTO NEW ENGLAND STATES EARLY WED WITH
LINGERING VORT MAX IN THE TRAILING PART OF THE TROUGH OVER ARKANSAS.
THIS FEATURE WILL CUT TO OUR SOUTH WEDNESDAY EVENING. WITH THE LOW
LEVELS ADVECTING COOL AND DRY AIR HOWEVER THIS UPPER FEATURE WILL
HAVE LITTLE TO NO EFFECT ON SENSIBLE WEATHER. THIS LOW WILL DEEPEN
JUST OFF THE COAST OF THE CAROLINAS EARLY THURSDAY BUT WILL QUICKLY
ACQUIRE A NEGATIVE TILT ALLOWING FOR HEIGHT RISES OVER THE COASTAL
PLAIN TO MOVE IN FROM THE WEST BY THE AFTERNOON. THESE HEIGHT RISES
WILL NOT BE REALIZED AT THE SURFACE...NORMALLY IN THE FORM OF
WARMING TEMPERATURES. WEAK SURFACE HIGH ACROSS THE SOUTHEAST WILL
KEEP MIXING FAIRLY SHALLOW. BOTH DAYS WILL BRING HIGHS IN THE UPPER
50S AND LOWS IN THE LOW TO UPPER 30S...MILDEST ALONG THE COAST BY
NIGHT.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM TUESDAY...LOW AMPLITUDE UPPER RIDGING CROSS THE AREA
FRIDAY AND SATURDAY WHILE SURFACE HIGH PRESSURE REMAINS TO OUR NNE.
THE LATTER WILL TEND TO OFFSET THE WARMING OF THE FORMER TO KEEP
TEMPS BELOW CLIMO. LARGE POSITIVELY TILTED TROUGHINESS DEVELOPS
OVER THE NORTH-CENTRAL PORTION OF THE COUNTRY FOR THE REMAINDER OF
THE PERIOD KEEPING THE AREA DRY. THE HIGH TO OUR NORTH SHOULD
PROGRESS TO THE EAST ENOUGH TO ALLOW FOR A SLIGHT MODERATION OF
TEMPS ESP BY MONDAY.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...SCATTERED SHRA ACTIVITY CONTINUES TO SPREAD ACROSS
PORTIONS OF THE CWA AS DEPICTED BY CURRENT RADAR. ANTICIPATE THIS
TREND TO PERSIST...WITH RAINFALL COVERAGE INCREASING TO NEARLY
ENCOMPASS THE ENTIRE AREA AHEAD OF AN ADVANCING COLD FRONT.
SOUTHEAST WINDS WILL CONTINUE AOB 12KTS AT KILM FOR THE NEXT HOUR OR
SO...AND WEST WINDS AT THE KFLO/KLBT/KCRE/KMYR AOB 15KTS...WIND
GUSTS AOB 30 KTS.

CURRENT GUIDANCE AND FCST SOUNDINGS SUGGEST THE FROPA WILL OCCUR
THROUGH THE OVERNIGHT AS IT PROPAGATES WEST TO EAST. LOW CONFIDENCE
REGARDING EXACT TIMING OF PASSAGE...BUT EXPECT MVFR SHRA/TSRA...WITH
BRIEF PERIODS OF IFR IN HEAVIER DOWNPOURS TO CONTINUE. GIVEN LOW
INSTABILITY VALUES...THE PROBABILITY OF WIDESPREAD TSRA IS
UNLIKELY...HOWEVER CANNOT RULE OUT AN ISOLATED THUNDERSTORM. LOCAL
WRF MODEL SUGGESTS SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE
THROUGH THIS MORNING. AFTER 14Z APPROXIMATELY...ANTICIPATE
CONDITIONS TO IMPROVE TO VFR FOR REMAINDER OF VALID PERIOD...THOUGH
AREAS OF MVFR CIGS MAY STILL LINGER TUESDAY MID-MORNING. WINDS WILL
GRADUALLY SHIFT MORE WEST-SOUTHWEST LATER THIS MORNING...WITH
PERIODS OF GUSTY WINDS AOB 25KTS THROUGHOUT THE AFTERNOON INTO EARLY
EVENING.

EXTENDED OUTLOOK...EXPECT VFR THROUGH PERIOD.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM TUESDAY...SFC COLD FRONT HAS PUSHED ACROSS THE LOCAL
WATERS EARLY THIS MORNING. THE ENSUING CAA UNDER SW-W WINDS 15-25 KT
WITH FEW GUSTS 30-35 KT WILL RULE THE DAY. THE SFC PG IS PROGGED TO
RE-TIGHTEN BY MIDDAY ACROSS THE WATERS RESULTING IN SUSTAINED WIND
SPEEDS ON THE HIGHER SIDE OF THE RANGE GIVEN. THE RISEN SEAS WILL
PEAK EARLY THIS MORNING...THEN SLOWLY SUBSIDE TODAY THROUGH TONIGHT.
SOME OF THE HIGHER SEAS...ESPECIALLY THE OUTER WATERS OFF CAPE FEAR
AND ROMAIN...WERE AIDED BY SEAS BLEEDING IN FROM THE OFFSHORE WATERS
WHERE WINDS AT GALE FORCE OCCURRED. THE LOW MID 70S SSTS WERE THE
BIG CONTRIBUTOR FOR THESE HIGHER WINDS MAKING IT TO THE OFFSHORE
OCEAN SFC. SWAN GUIDANCE FOR SEAS WAS USED...BUT DID NOT LOWER THEM
AS FAST AS WHAT SWAN WAS INDICATING. THE SCA MAY NEED TO BE
EXTENDED FURTHER INTO TONIGHT...ESPECIALLY THE WATERS FROM CAPE FEAR
NORTHWARD. AVERAGE PERIODS WILL RUN 6-8 SECONDS THROUGH EARLY THIS
AFTERNOON. THE AVERAGE PERIODS WILL DECREASE TO 4 TO 6 SECONDS LATE
THIS AFTERNOON AND TONIGHT DUE TO WESTERLY WINDS ACROSS A DIMINISHED
FETCH AREA.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...WESTERLY WINDS ON WEDNESDAY WILL BE THE LAST
REMAINING EFFECTS OF THE PREVIOUS STORM SYSTEM...WHICH BY WED WILL
BE RAPIDLY MOVING INTO THE NEW ENGLAND STATES. WIND WILL THEN
TRANSITION OVER TO NORTHERLY LATE WEDNESDAY DUE TO HIGH PRESSURE
BUILDING IN FROM THE WEST. A FAIRLY ROBUST UPPER SYSTEM WILL CROSS
THE WATERS EARLY THURSDAY. POOR DIRECTIONAL ALIGNMENT OF WIND IN THE
VERTICAL HOWEVER WILL PREVENT THIS FROM MAKING MUCH OF A DIRECT
EFFECT/INCREASE IN SURFACE WIND SPEEDS. NO HEADLINES EXPECTED THIS
PERIOD FOR THE MOST PART. THE EXCEPTION MAY BE TOWARDS THE END OF
THE PERIOD WHEN SOME 5 FT SEAS MANAGE TO AFFECT THE VERY OUTER
REACHES OF THE 20NM FCST ZONE.

LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 AM TUESDAY...N TO NE FLOW ON THE SOUTHEAST PERIPHERY OF HIGH
PRESSURE WILL CHARACTERIZE MOST OF THE PERIOD. WHILE WIND SPEED MAY
SHOW LITTLE VARIATION THOUGH THE PERIOD THE INCREASING TIME OF THE
STEADY FETCH COULD ADD SLIGHTLY TO WAVE HEIGHTS. 5 FT SEAS MAY
OCCASIONALLY BE AFFECTING THE OUTER PORTIONS OF MAINLY THE NORTHERN
ZONES. IT IS THUS HARD TO ASCERTAIN THE NEED FOR ANY CAUTIONARY
HEADLINES THIS FAR OUT IN TIME.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST TUESDAY FOR AMZ250-252-
     254-256.

&&

$$

SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...SGL











AREA FORECAST DISCUSSION

NWS WILMINGTON NC

 300 AM EST TUE NOV 29 2011

.SYNOPSIS...
COOLER AND DRIER AIR WILL BE USHERED IN FROM THE WEST TODAY. HIGH
PRESSURE WILL BUILD ACROSS THE EASTERN CAROLINAS FOR THE REMAINDER
OF THE WEEK. THIS HIGH WILL SHIFT OFF THE NORTHEAST COAST OVER THE
WEEKEND POSSIBLY ALLOWING FOR A SLIGHT MODERATION BACK TOWARDS
SEASONABLE TEMPERATURES.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 1120 PM EST MONDAY...ADJUSTMENTS MADE TO PCPN COVERAGE AND
MOVEMENT ACROSS THE ILM CWA FOR THE REMAINDER OF THE OVERNIGHT. THE
2 DISTINCT BROKEN LINES OF CONVECTION EARLIER ARE MESHING INTO 1 AT
THE MOMENT. THE POTENTIAL SVR WX THREAT WILL OCCUR IMMEDIATELY ALONG
THE LINE OF CONVECTION THAT BASICALLY NOW BISECTS THE ILM CWA...FROM
CRE TO LBT. SMALL COUPLETS NOTED ON LOW LEVEL SRM...HOWEVER THEY
HAVE NOT BEEN STRONG OR TIGHT ENOUGH TO WORKS THEIR WAY TO THE SFC.
WIND THREAT OR TORNADO THREAT DUE TO DECENT LOW LEVEL WIND SHEAR
BOTH FROM DIRECTION AND VELOCITY...AS SEEN WITH 00Z TUE CHS RAOB
FLIGHT AND HODOGRAPHS. HAVE ADJUSTED PCPN MOVEMENTS BASED ON LATEST
RADAR MOSAIC TRENDS AND HRRR OUTPUT. WITH THIS INPUT...1/3 TO 1/2 OF
THE ILM CWA WILL STILL HAVE TO DEAL WITH PCPN BY DAYBREAK TUESDAY.
THE SEVERE WX THREAT ALONG THE LEADING EDGE OF THE CONVECTION WILL
HAVE MOVED NORTH AND EAST OF THE ILM CWA BY SUN-UP. BEST CAA AND
DRIER AIR TO OCCUR DURING THE DAY TUESDAY.


&&


.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...COOL AND DRY WEATHER IS ON TAP FOR THE DURATION
OF THE SHORT TERM PERIOD. CUTOFF UPPER LOW WILL BE QUICKLY EXITING
TO THE NE ACRS NY AND INTO NEW ENGLAND STATES EARLY WED WITH
LINGERING VORT MAX IN THE TRAILING PART OF THE TROUGH OVER ARKANSAS.
THIS FEATURE WILL CUT TO OUR SOUTH WEDNESDAY EVENING. WITH THE LOW
LEVELS ADVECTING COOL AND DRY AIR HOWEVER THIS UPPER FEATURE WILL
HAVE LITTLE TO NO EFFECT ON SENSIBLE WEATHER. THIS LOW WILL DEEPEN
JUST OFF THE COAST OF THE CAROLINAS EARLY THURSDAY BUT WILL QUICKLY
ACQUIRE A NEGATIVE TILT ALLOWING FOR HEIGHT RISES OVER THE COASTAL
PLAIN TO MOVE IN FROM THE WEST BY THE AFTERNOON. THESE HEIGHT RISES
WILL NOT BE REALIZED AT THE SURFACE...NORMALLY IN THE FORM OF
WARMING TEMPERATURES. WEAK SURFACE HIGH ACROSS THE SOUTHEAST WILL
KEEP MIXING FAIRLY SHALLOW. BOTH DAYS WILL BRING HIGHS IN THE UPPER
50S AND LOWS IN THE LOW TO UPPER 30S...MILDEST ALONG THE COAST BY
NIGHT.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM TUESDAY...LOW AMPLITUDE UPPER RIDGING CROSS THE AREA
FRIDAY AND SATURDAY WHILE SURFACE HIGH PRESSURE REMAINS TO OUR NNE.
THE LATTER WILL TEND TO OFFSET THE WARMING OF THE FORMER TO KEEP
TEMPS BELOW CLIMO. LARGE POSITIVELY TILTED TROUGHINESS DEVELOPS
OVER THE NORTH-CENTRAL PORTION OF THE COUNTRY FOR THE REMAINDER OF
THE PERIOD KEEPING THE AREA DRY. THE HIGH TO OUR NORTH SHOULD
PROGRESS TO THE EAST ENOUGH TO ALLOW FOR A SLIGHT MODERATION OF
TEMPS ESP BY MONDAY.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...SCATTERED SHRA ACTIVITY CONTINUES TO SPREAD ACROSS
PORTIONS OF THE CWA AS DEPICTED BY CURRENT RADAR. ANTICIPATE THIS
TREND TO PERSIST...WITH RAINFALL COVERAGE INCREASING TO NEARLY
ENCOMPASS THE ENTIRE AREA AHEAD OF AN ADVANCING COLD FRONT.
SOUTHEAST WINDS WILL CONTINUE AOB 12KTS AT KILM FOR THE NEXT HOUR OR
SO...AND WEST WINDS AT THE KFLO/KLBT/KCRE/KMYR AOB 15KTS...WIND
GUSTS AOB 30 KTS.

CURRENT GUIDANCE AND FCST SOUNDINGS SUGGEST THE FROPA WILL OCCUR
THROUGH THE OVERNIGHT AS IT PROPAGATES WEST TO EAST. LOW CONFIDENCE
REGARDING EXACT TIMING OF PASSAGE...BUT EXPECT MVFR SHRA/TSRA...WITH
BRIEF PERIODS OF IFR IN HEAVIER DOWNPOURS TO CONTINUE. GIVEN LOW
INSTABILITY VALUES...THE PROBABILITY OF WIDESPREAD TSRA IS
UNLIKELY...HOWEVER CANNOT RULE OUT AN ISOLATED THUNDERSTORM. LOCAL
WRF MODEL SUGGESTS SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE
THROUGH THIS MORNING. AFTER 14Z APPROXIMATELY...ANTICIPATE
CONDITIONS TO IMPROVE TO VFR FOR REMAINDER OF VALID PERIOD...THOUGH
AREAS OF MVFR CIGS MAY STILL LINGER TUESDAY MID-MORNING. WINDS WILL
GRADUALLY SHIFT MORE WEST-SOUTHWEST LATER THIS MORNING...WITH
PERIODS OF GUSTY WINDS AOB 25KTS THROUGHOUT THE AFTERNOON INTO EARLY
EVENING.

EXTENDED OUTLOOK...EXPECT VFR THROUGH PERIOD.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1135 PM MONDAY...MID 70S SSTS LURKING JUST OFFSHORE FROM THE
ILM COASTAL WATERS...WITH 41013 AND 41004 BUOYS EXHIBITING THESE
WARMER WATER TEMPS. NEAR SHORE...LOW TO MID 60S REMAIN COMMON PER
LATEST OMRILM REPORTS. THE GRADIENT WINDS WILL FURTHER INCREASE
ACROSS ALL OF THE ILM WATERS THROUGH THE NIGHT REACHING STRONG SCA
CRITERIA. HOWEVER THE 40 TO 50 KT WINDS...IE. LOW LEVEL JET AT
925MB...ILLUSTRATED WELL BY THE LATEST KLTX VWP AND HRRR MODEL WILL
HAVE A DIFFICULT TIME REACHING THE OCEAN SFC...EVEN AS WIND
GUSTS...DUE TO THE COOLER SHELF WATERS. THESE HIGHER WINDS JUST OFF
THE DECK ARE LIKELY MAKING IT TO THE OCEAN SFC AS SUSTAINED AND/OR
WIND GUSTS ACROSS THE WARMER SSTS...VIA THE LATEST 41013 AND 41004
LATEST BUOY REPORTS. THE BIG KAHUNAS IN DC REMAIN VIGILANT AND
CONTINUE WITH THE GALE WARNING UP FOR THE OFFSHORE WATERS ADJACENT
TO THE ILM COASTAL WATERS.

HAVE INCREASED SEAS ACROSS THE ILM WATERS AND THE IMMEDIATE ADJACENT
OFFSHORE WATERS THROUGH THE TUESDAY PREDAWN HRS. WITH SIX TO 9 FT
BEING COMMON...EXCEPT UP TO 10-11 FT ACROSS THE SHALLOW OUTERWATERS
OFF CAPE FEAR. THE COLD FRONT...IDENTIFIED BY ENHANCED CONVECTION
JUST AHEAD OF IT...WILL TRACK ENE AND REACH THE WATERS BETWEEN SURF
CITY AND CAPE FEAR BY DAYBREAK. HAVE IDENTIFIED THE IMMEDIATE WIND
SWITCH FROM SE-S...THEN TO SW DURING THE DAY TUESDAY.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...WESTERLY WINDS ON WEDNESDAY WILL BE THE LAST
REMAINING EFFECTS OF THE PREVIOUS STORM SYSTEM...WHICH BY WED WILL
BE RAPIDLY MOVING INTO THE NEW ENGLAND STATES. WIND WILL THEN
TRANSITION OVER TO NORTHERLY LATE WEDNESDAY DUE TO HIGH PRESSURE
BUILDING IN FROM THE WEST. A FAIRLY ROBUST UPPER SYSTEM WILL CROSS
THE WATERS EARLY THURSDAY. POOR DIRECTIONAL ALIGNMENT OF WIND IN THE
VERTICAL HOWEVER WILL PREVENT THIS FROM MAKING MUCH OF A DIRECT
EFFECT/INCREASE IN SURFACE WIND SPEEDS. NO HEADLINES EXPECTED THIS
PERIOD FOR THE MOST PART. THE EXCEPTION MAY BE TOWARDS THE END OF
THE PERIOD WHEN SOME 5 FT SEAS MANAGE TO AFFECT THE VERY OUTER
REACHES OF THE 20NM FCST ZONE.

LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 AM TUESDAY...N TO NE FLOW ON THE SOUTHEAST PERIPHERY OF HIGH
PRESSURE WILL CHARACTERIZE MOST OF THE PERIOD. WHILE WIND SPEED MAY
SHOW LITTLE VARIATION THOUGH THE PERIOD THE INCREASING TIME OF THE
STEADY FETCH COULD ADD SLIGHTLY TO WAVE HEIGHTS. 5 FT SEAS MAY
OCCASIONALLY BE AFFECTING THE OUTER PORTIONS OF MAINLY THE NORTHERN
ZONES. IT IS THUS HARD TO ASCERTAIN THE NEED FOR ANY CAUTIONARY
HEADLINES THIS FAR OUT IN TIME.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST TUESDAY FOR AMZ250-252-
     254-256.

&&

$$

NEAR TERM...DCH/MJC
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...SGL








AREA FORECAST DISCUSSION...UPDATED

NWS NEWPORT/MOREHEAD CITY NC

 1254 AM EST TUE NOV 29 2011

.SYNOPSIS...
A COLD FRONT WILL SWEEP THROUGH THE AREA TODAY FROM THE WEST.
HIGH PRESSURE WILL BUILD INTO NORTH CAROLINA WEDNESDAY THROUGH
THURSDAY. ANOTHER COLD FRONT WILL PASS THROUGH THE REGION FRIDAY
NIGHT. HIGH PRESSURE WILL ONCE AGAIN BUILD INTO THE AREA NEXT
WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 1250 AM TUES...EASTERN NORTH CAROLINA REMAINS PINCHED
BETWEEN HIGH PRESSURE NORTHEAST OF THE REGION AND A STRONG COLD
FRONT APPROACHING FROM THE WEST. THE NORTH TO SOUTH ORIENTED COLD
FRONT WILL BEGIN IMPACTING WESTERN ZONES DUPLIN COUNTY NORTH TO
PITT COUNTY BETWEEN 08-10Z WITH HEAVY SHOWERS WITH ISOLATED
THUNDER POSSIBLE. THREAT FOR SEVERE WEATHER REMAINS MINIMAL DUE TO
LACK OF INSTABILITY. SHEAR PROFILES ARE IMPRESSIVE WITH LLJ OF 35
KNOTS BASED ON LATEST LAPS SOUNDING. SOUTHEASTERLY WINDS WILL
CONTINUE 8-10 KNOTS WITH GUSTS UPWARDS OF 15 KNOTS DUE THE
PRESSURE GRADIENT. ONLY MINOR TWEAKS TO POPS/WX/TEMPS FOR THE
SHORT TERM EARLY MORNING UPDATE.

PREVIOUS DISCUSSION...MOIST SOUTHEASTERLY FLOW CONTINUES ACROSS THE
REGION THIS EVENING AHEAD OF A STRONG COLD FRONT PRESENTLY SLOWLY
MOVING ACROSS THE NC PIEDMONT AND INTO SERN NC WITH ASSOC UPPER
LOW SLOWLY PUSHING ACROSS NRN MS/AL AND S CNTRL TN. 00Z KMHX
SOUNDING SHOWS FAIRLY MOIST BELOW 800 MB BUT REMAINS DRY ABOVE
WITH PW`S SIMILAR TO THIS MORNING AROUND 0.85". DON`T THINK WE
WILL SEE MORE THAN AN ISOLATED LIGHT SHOWER THROUGH THE REMAINDER
OF THE EVENING WITH MOISTURE REMAINING SHALLOW. LATEST HRRR MODEL
RUN INDICATING STRONGER FORCING/HEAVIER PCPN PUSHING INTO DUPLIN
CO AROUND 3 AM AND TO NEAR A CAPE LOOKOUT TO GREENVILLE LINE BY 6
AM...WHICH IS CLOSE TO THE LEAD TIME OF ARRIVAL TOOLS.

AS THE FRONT MOVES EAST OVERNIGHT...LLJ WILL INC TO AOA 40 KT WITH
PWATS INC TO AROUND 1.5 INCHES. TREMENDOUS KINEMATICS WILL BE IN
PLACE WITH THE COLD FRONT...THOUGH LACKING INGREDIENT WILL BE
INSTABILITY. STILL...AN ISOLATED EMBEDDED STORM IS STILL POSSIBLE
AS FORCING WILL BE VERY STRONG... AND MAY PRODUCE LOCALLY DAMAGING
WIND GUSTS.

TEMPS THIS EVENING HAVE FALLEN INTO THE M/U60S AND DON`T EXPECT
THEM TO DROP MUCH MORE OVERNIGHT AS STRONG WAA PERSISTS AHEAD OF
THE FRONT...THE EXCEPTION BEING FAR WRN PORTION OF THE CWA WHERE
THE FRONT IS EXPECTED TO REACH BY 6 AM AND COULD SEE TEMPS FALLING
TO AROUND 60 AFTER FROPA.

&&

.SHORT TERM /TONIGHT/...
AS OF 3 PM MON...LINE OF SHOWERS WILL TRANSLATE EAST INTO THE
REST OF THE FA THROUGH THE MORNING ON TUE...REACHING THE OBX
AROUND THE NOON HOUR. AN ISO THUNDERSTORM WILL STILL BE
POSSIBLE...THOUGH STRONG CAA WILL LIMIT THE POTENTIAL FOR ANYTHING
MORE THAN AN ISO MENTION. DAYTIME HIGHS IN THE 60S WILL BE
REALIZED TUE MORNING...WITH TEMPS FALLING FROM WEST TO EAST
THROUGHOUT THE DAY BEHIND THE FROPA. BY AFTERNOON MANY AREAS WILL
HAVE DROPPED WELL INTO THE 50S. RAIN WILL CLEAR OUT FOR MOST AREAS
EXCEPT THE OBX BY EARLY AFTERNOON...WITH ONLY SOME SCT SHOWERS
REMAINING.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
CUTOFF LOW MOVES QUICKLY NORTH UP THE APPALACHIANS TUE NIGHT. WEAK
SFC RIDGE BUILDS ACROSS THE AREA TUE NIGHT IN THE WAKE OF COLD
FRONTAL PASSAGE. ANY LINGERING SHOWERS WILL BE ENDING OVER THE OUTER
BANKS EARLY TUE EVENING AS THE MID LEVEL DRYING MOVES TO THE COAST.
MUCH COOLER AIR WILL WORK INTO THE AREA AROUND THE DEPARTING UPPER
LOW WITH LOW TEMPS TUE NIGHT FALLING INTO THE 30S INLAND WITH
LOW-MID 40S AT THE COAST.

BELOW NORMAL TEMPERATURES WILL HIGHLIGHT THE WED THRU SAT TIMEFRAME
AS SEVERAL REINFORCING SHOTS OF COOLER AIR INVADE THE AREA. MOISTURE
WILL BE TOO SCARCE FOR ORGANIZED PCPN BUT MAY SEE CLOUDY INTERVALS
AS WEAK SHORT WAVES PASS THRU THE AREA.

TEMPERATURES WILL BEGIN TO MODERATE LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK AS RETURN FLOW GRADUALLY SETS UP AHEAD OF DOWNSTREAM
TROF. TIMING OF PCPN CHCS MAY BE TIED TO PROGRESSIVENESS OF LARGE
SCALE TROF BEING CARVED OUT OVER THE UPPER MIDWEST EARLY NEXT WEEK.
WILL KEEP THE DAY 7 FCST DRY FOR NOW UNTIL THE TIMING OF THIS
DOWNSTREAM FEATURE CAN BE BETTER RESOLVED.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1250 AM TUES...VFR CONDITIONS WILL DIMINISH TO IFR FROM
WEST TO EAST EARLY THIS MORNING ASSOCIATED WITH HEAVY SHOWERS
ALONG A STRONG NORTH TO SOUTH ORIENTED COLD FRONT PUSHING EAST
INTO EASTERN NC. OAJ/ISO WILL SEE LOWERED CEILINGS AND
VISIBILITIES BETWEEN 08-09Z FOLLOW SHORTLY BY PGV AND EWN. AWOS
ISSUES CONTINUE AT PGV SO WILL LIST AMENDMENT NOT SKED FOR PGV AT
THIS TIME. TAFS EXPECTED TO SEE 5-7 HOURS OF IFR CONDITIONS EARLY
THIS MORNING IMPROVING TO MVFR/VFR BY EARLY AFTERNOON. LOW CLOUDS
WILL LIFT AND BECOME BKN/OVC AROUND 5K FT BY LATE AFTERNOON...WITH
WINDS VEERING SOUTH THEN SOUTHWEST BEHIND THE FRONT.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
VFR CONDITIONS EXPECTED FOR A LARGE PART OF THIS FCST PERIOD AS
DRIER AIR FILTERS INTO THE REGION. MAY BE SOME CLOUDY INTERVALS DUE
TO WEAK SHORT WAVE PASSAGES BUT EXPECT CLOUD BASES WILL BE HIGHER
THAN 3K FT FOR THE MOST PART. MAY ALSO SEE BRIEF/PATCHY LATE
NIGHT/EARLY MORNING RADIATION FOG AS DEW POINT DEPRESSIONS LOWER
LATER IN THE WEEK.

&&

.MARINE...
SHORT TERM /THROUGH TUESDAY/...
AS OF 1250 AM TUES...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE
SOUTHEAST WINDS 10 TO 20 KNOTS. SOUTHEAST WINDS WILL CONTINUE 15
TO 20 OVERNIGHT AND GUST UPWARDS OF 30 KNOTS...PER LATEST UPSTREAM
BUOY REPORT FROM FRYING PAN SHOALS. SEAS REMAIN 6-10 FT SOUTH OF
DIAMOND SHOALS WITH 3 TO 6 FT NORTH. NO SIGNIFICANT CHANGES TO THE
SHORT TERM FORECAST WITH THE MORNING UPDATE.

PREVIOUS DISCUSSION...WINDS AND SEAS GRADUALLY INCREASING THIS
EVENING AHEAD OF A STRONG COLD FRONT PRESENTLY PUSHING ACROSS SC.
FORECAST LOOKS ON TRACK WITH WINDS AROUND 15-20 KT SRN AND CENTRAL
WATERS AND 10-15 KT ELSEWHERE. SEAS ARE ALSO BUILDING ACROSS
SRN/CENTRAL WATERS WHERE BUOY 41036 NOW UP TO 8FT. GRADIENT INC
FURTHER AS THE STRONG COLD FRONT APPROACHES LATE TONIGHT...AND
WINDS AND SEAS WILL CONTINUE TO INC. SEAS WILL INC AND BUILD FROM
S TO N...WITH SCA CONDITIONS BEING MET FOR THE NORTHERN WATERS BY
EARLY TUE MORNING. KEPT SCA OUT OF THE SOUNDS FOR NOW...AS THE
COOLER WATERS SHOULD KEEP WINDS JUST BELOW THE 25 KT
THRESHOLD...THOUGH GUSTS MAY GET CLOSE TO THAT BY EARLY TUE
MORNING. WINDS WILL VEER FROM SE TO SW BEHIND THE COLD FRONT LATE
TUE MORNING THROUGH AFTERNOON.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODERATE (15-20KT) SW/W WINDS TUE NIGHT/WED WILL SHIFT MORE NW/N AT
ROUGHLY THE SAME SPEEDS AS WEAK SFC TROF PASSES ON THURSDAY. SEAS
WILL INITIALLY FALL BLO SMALL CRAFT ADVISORY LEVELS (6 FT) FOR A
TIME LATE WED/WED NIGHT BEFORE BUILDING BACK ABV 6 FT AGAIN AS WINDS
BECOME MORE NORTHERLY AND CONTINUE AT MODERATE LEVELS THU-SAT.
THEREFORE SMALL CRAFT ADVISORIES MAY AGAIN BE REQUIRED LATER IN THE
WEEK...MAINLY FOR SEAS.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR AMZ152-154.
     SMALL CRAFT ADVISORY UNTIL 4 PM EST WEDNESDAY FOR AMZ156-158.
     SMALL CRAFT ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 AM EST
     WEDNESDAY FOR AMZ150.

&&

$$
SYNOPSIS...DAG
NEAR TERM...SK/DAG/TL
SHORT TERM...TL
LONG TERM...BTC
AVIATION...BTC/DAG
MARINE...BTC/DAG/SK/TL





AREA FORECAST DISCUSSION

NWS WILMINGTON NC

 1145 PM EST MON NOV 28 2011

.SYNOPSIS...
A STORM SYSTEM APPROACHING THE AREA FROM THE GULF COAST STATES WILL
BRING SHOWERS AND A FEW THUNDERSTORMS ACROSS THE AREA THROUGH
TUESDAY MORNING. THE ASSOCIATED COLD FRONT WILL PUSH THROUGH DURING
TUESDAY ALLOWING COOLER AND DRIER AIR TO INFILTRATE THE AREA IN ITS
WAKE. HIGH PRESSURE WILL BUILD ACROSS THE EASTERN CAROLINAS
WEDNESDAY THROUGH FRIDAY...THEN GIVE WAY TO THE NEXT DRY COLD
FRONTAL PASSAGE FRIDAY NIGHT. COOL HIGH PRESSURE WILL AFFECT THE
AREA THIS WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 1120 PM EST MONDAY...ADJUSTMENTS MADE TO PCPN COVERAGE AND
MOVEMENT ACROSS THE ILM CWA FOR THE REMAINDER OF THE OVERNIGHT. THE
2 DISTINCT BROKEN LINES OF CONVECTION EARLIER ARE MESHING INTO 1 AT
THE MOMENT. THE POTENTIAL SVR WX THREAT WILL OCCUR IMMEDIATELY ALONG
THE LINE OF CONVECTION THAT BASICALLY NOW BISECTS THE ILM CWA...FROM
CRE TO LBT. SMALL COUPLETS NOTED ON LOW LEVEL SRM...HOWEVER THEY
HAVE NOT BEEN STRONG OR TIGHT ENOUGH TO WORKS THEIR WAY TO THE SFC.
WIND THREAT OR TORNADO THREAT DUE TO DECENT LOW LEVEL WIND SHEAR
BOTH FROM DIRECTION AND VELOCITY...AS SEEN WITH 00Z TUE CHS RAOB
FLIGHT AND HODOGRAPHS. HAVE ADJUSTED PCPN MOVEMENTS BASED ON LATEST
RADAR MOSAIC TRENDS AND HRRR OUTPUT. WITH THIS INPUT...1/3 TO 1/2 OF
THE ILM CWA WILL STILL HAVE TO DEAL WITH PCPN BY DAYBREAK TUESDAY.
THE SEVERE WX THREAT ALONG THE LEADING EDGE OF THE CONVECTION WILL
HAVE MOVED NORTH AND EAST OF THE ILM CWA BY SUN-UP. BEST CAA AND
DRIER AIR TO OCCUR DURING THE DAY TUESDAY.


&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...THE NAM...GFS AND ECMWF ARE IN FAIRLY GOOD
AGREEMENT WITH THE HANDLING TO THE CUT-OFF LOW AT 500 HPA THROUGH
48 HOURS. AFTER 48 HOURS...THE NAM`S REPRESENTATION OF THE SURFACE
LOW TRAILS THE OTHER MODELS AT 48H. AT THE SURFACE THESE THREE
MODELS ARE VERY SIMILAR WITH THE OCCLUDED LOW AS THEY MOVE THE LOW
FROM NORTHERN GEORGIA TO LAKE ERIE BY LATE WEDNESDAY NIGHT. BY 12
UTC TUESDAY...THE COLD FRONT AND ITS ASSOCIATED PRECIPITATION
SHIELD WILL BE OVER THE NORTHERN SECTIONS FOR THE FORECAST AREA
AND MOVING OUT OF THE AREA BEFORE NOON. AFTER THE FRONT SHIFTS
EAST-NORTHEASTWARD COOLER AIR WILL SPILL IN AND MAXIMUM
TEMPERATURES WILL STRUGGLE TO GET OUT OF THE UPPER 50S TO NEAR 60
ON TUESDAY AND ONLY IN THE UPPER 50S WEDNESDAY. LOW TEMPERATURES
ARE EXPECTED TO REMAIN IN THE MID TO UPPER 30S.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...SHORTWAVE WILL CROSS THE AREA THURS MORNING WITH
MID TO UPPER RIDGE BUILDING UP THE SOUTHEAST COAST LATE THURS
THROUGH SAT. AT THE SURFACE...HIGH PRESSURE WILL BUILD IN ON THURS.
THE CENTER OF HIGH WILL REMAIN WEST OF AREA WITH A DEEP NORTHERLY
FLOW OF COOL AND DRY AIR LASTING THROUGH SATURDAY. A WEAK MOISTURE
STARVED BOUNDARY MAY SLIDE SOUTH LATE FRI INTO EARLY SAT AS EVIDENT
IN MOISTURE AND WIND FIELDS BUT RIDGE BUILDING UP THE COAST MAY HOLD
IT OFF TO THE NORTH AND EAST AND OVERALL EFFECT WILL NOT BE MUCH.
MOISTURE WILL BE LIMITED AS PCP WATER VALUES WILL BE DOWN CLOSE TO A
QUARTER OF AN INCH WITH A SPIKE UP NEAR A HALF INCH AS FLOW COMES
AROUND FROM THE N-NW TO NE BY SAT NIGHT. OVERALL MAY SEE SOME CLOUDS
AS SHORTWAVE MOVES THROUGH ON THURS AND ASSOCIATED WITH BACK DOOR
FRONTAL BOUNDARY LATE FRI BUT NOT EXPECTING ANY PCP THROUGH THE
FIRST HALF OF THE WEEKEND AND SHOULD SEE A GOOD DEAL OF SUNSHINE.
GRADIENT RELAXES THROUGH THE WEEKEND AS HIGH PRESSURE EXTENDS DOWN
INTO THE CAROLINAS.

RIDGE SHIFTS OFF SHORE SUNDAY INTO MONDAY WITH A RETURN FLOW SETTING
UP ALOFT BUT THE SURFACE FLOW WILL BE A LITTLE SLOWER TO COME AROUND
AS CENTER OF HIGH SHIFTS OFF THE NEW ENGLAND COAST EARLY SUNDAY WITH
RIDGE EXTENDING SW DOWN INTO THE CAROLINAS MAINTAINING A NE TO E
FLOW THROUGH SUNDAY. BY MONDAY A DEEPER SOUTHERLY RETURN FLOW SETS
UP FROM THE SURFACE UP THROUGH THE MID TO UPPER LEVELS. PCP WATER
VALUES INCREASE THROUGH SUNDAY UP CLOSE TO THREE QUARTERS OF INCH
AND THEN UP TOWARDS 1.5 INCHES IN INCREASINGLY MOIST SOUTHERLY FLOW
LATE MONDAY INTO EARLY TUES AHEAD OF APPROACHING COLD FRONT.

AS FOR TEMPS...BEST CAA THROUGH THE PERIOD WILL COME IN DEEP
NORTHERLY FLOW ONCE SHORTWAVE CLEARS THE COAST ON THURS. H5 HEIGHTS
WILL INCREASE AS RIDGE BUILDS LATE THURS INTO THE WEEKEND. EXPECT
850 TEMPS TO DROP THURS WITH STEADY READINGS OR SLIGHT INCREASE
THEREAFTER. WITH PLENTY OF DRY AIR IN PLACE AND DEWPOINT TEMPS BELOW
40 IN MOST PLACES THURS THROUGH SUNDAY...EXPECT LARGER DIURNAL
SWINGS WITH TEMPS MAKING IT TO 55 TO CLOSE TO 60 FOR HIGHS AND DOWN
BELOW 40 MOST NIGHTS. WARMING TREND BEGINS EARLY NEXT WEEK WITH
TEMPS REBOUNDING CLOSER TO 70 BY MONDAY.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...ISOLATED TO SCATTERED -SHRA ACTIVITY CONTINUES TO SPREAD
ACROSS WESTERN PORTIONS OF THE CWA AS DEPICTED BY CURRENT RADAR.
ANTICIPATE THIS TREND TO PERSIST OVER THE NEXT COUPLE OF
HOURS...WITH RAINFALL COVERAGE INCREASING ACROSS THE AREA AHEAD OF
AN ADVANCING COLD FRONT. SOUTHEAST WINDS WILL CONTINUE AOB
12KTS...WITH INCREASING WIND GUSTS AOB 25 KTS.

CURRENT GUIDANCE AND FCST SOUNDINGS SUGGEST THE FROPA WILL OCCUR
LATE TONIGHT INTO THE OVERNIGHT HOURS...AS IT PROPAGATES WEST TO
EAST. LOW CONFIDENCE REGARDING EXACT TIMING OF PASSAGE...BUT EXPECT
MVFR SHRA/TSRA...WITH PERIODS OF IFR POSSIBLE IN HEAVIER DOWNPOURS.
GIVEN LOW INSTABILITY VALUES...THE PROBABILITY OF WIDESPREAD TSRA IS
UNLIKELY...HOWEVER CANNOT RULE OUT ISOLATED CONVECTION...THUS HAVE
KEPT IN VCTS AND CB IN FCST. LOCAL WRF MODEL SUGGESTS SHOWERS AND
ISOLATED THUNDERSTORMS WILL CONTINUE THROUGH TUESDAY MORNING. AFTER
14Z APPROXIMATELY...ANTICIPATE CONDITIONS TO IMPROVE TO VFR FOR
REMAINDER OF VALID PERIOD...THOUGH AREAS OF MVFR CIGS MAY STILL
LINGER TUESDAY MID-MORNING. EXPECT WINDS TO GRADUALLY SHIFT MORE
WEST-SOUTHWEST TUESDAY MORNING...WITH PERIODS OF GUSTY WINDS AOB
20KTS.

EXTENDED OUTLOOK...EXPECT VFR THROUGH PERIOD.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1135 PM MONDAY...MID 70S SSTS LURKING JUST OFFSHORE FROM THE
ILM COASTAL WATERS...WITH 41013 AND 41004 BUOYS EXHIBITING THESE
WARMER WATER TEMPS. NEAR SHORE...LOW TO MID 60S REMAIN COMMON PER
LATEST OMRILM REPORTS. THE GRADIENT WINDS WILL FURTHER INCREASE
ACROSS ALL OF THE ILM WATERS THROUGH THE NIGHT REACHING STRONG SCA
CRITERIA. HOWEVER THE 40 TO 50 KT WINDS...IE. LOW LEVEL JET AT
925MB...ILLUSTRATED WELL BY THE LATEST KLTX VWP AND HRRR MODEL
...WILL HAVE A DIFFICULT TIME REACHING THE OCEAN SFC...EVEN AS WIND
GUSTS...DUE TO THE COOLER SHELF WATERS. THESE HIGHER WINDS JUST OFF
THE DECK ARE LIKELY MAKING IT TO THE OCEAN SFC AS SUSTAINED AND/OR
WIND GUSTS ACROSS THE WARMER SSTS...VIA THE LATEST 41013 AND 41004
LATEST BUOY REPORTS. THE BIG KAHUNAS IN DC REMAIN VIGILANT AND
CONTINUE WITH THE GALE WARNING UP FOR THE OFFSHORE WATERS ADJACENT
TO THE ILM COASTAL WATERS.

HAVE INCREASED SEAS ACROSS THE ILM WATERS AND THE IMMEDIATE ADJACENT
OFFSHORE WATERS THROUGH THE TUESDAY PREDAWN HRS. WITH SIX TO 9 FT
BEING COMMON...EXCEPT UP TO 10-11 FT ACROSS THE SHALLOW OUTERWATERS
OFF CAPE FEAR. THE COLD FRONT...IDENTIFIED BY ENHANCED CONVECTION
JUST AHEAD OF IT...WILL TRACK ENE AND REACH THE WATERS BETWEEN SURF
CITY AND CAPE FEAR BY DAYBREAK. HAVE IDENTIFIED THE IMMEDIATE WIND
SWITCH FROM SE-S...THEN TO SW DURING THE DAY TUESDAY.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...THE FORECAST PERIOD WILL BEGIN WITH THE SURFACE
COLD FRONT CROSSING THE WATERS AND WINDS BLOWING FROM WEST TO
SOUTHWEST AT 15 TO 20 KNOTS WITH A QUICK INCREASE IN WINDS WITH A
SHOT OF COLD AIR ADVECTION BY NIGHTFALL.  SEAS ARE EXPECTED TO
REMAIN AT SMALL CRAFT CONDITIONS RANGE THROUGH TUESDAY NIGHT BEFORE
SLOWLY FALLING BELOW CRITERIA. WINDS WILL BE WESTERLY ON WEDNESDAY
AND WILL SHIFT TO THE NORTHWEST AS THE FINAL TROUGH FROM THE UPPER
LEVEL SYSTEM THAT PAST TO THE NORTHWEST OF THE WATERS ON TUESDAY.

LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...ONCE SHORTWAVE CLEARS THE WATERS ON
THURS...HIGH PRESSURE WILL BUILD IN WITH RIDGE BUILDING ALOFT
THROUGH THE PERIOD. OVERALL EXPECT DEEP COOL NORTHERLY FLOW
THROUGH MOST OF THE PERIOD. WINDS WILL VEER SLIGHTLY FROM N TO NE
BY SAT NIGHT AS CENTER OF HIGH PRESSURE SHIFTS OFF THE NEW ENGLAND
COAST. GRADIENT MAY RELAX LATE THURS THROUGH FRI AS ONE AREA OF
HIGH PRESSURE MOVES OFF SHORE BUT WILL TIGHTEN AGAIN FRI NIGHT
INTO SAT AS WEAK BACK DOOR FRONT MOVES SOUTH WITH SECOND AREA OF
HIGH PRESSURE BUILDING IN FOR SAT. THEREFORE NORTHERLY WINDS
AROUND 15 KTS ON THURS MAY DECREASE TO 10 TO 15 KTS BY FRI BEFORE
INCREASING AGAIN TO A SOLID 15 KTS IN THE OUTER WATERS FRI NIGHT
INTO SAT. THE ALONG SHORE WINDS WILL CREATE HIGHER SEAS OFF SHORE
THROUGH THE PERIOD. EXPECT SEAS CLOSER TO 1 TO 2 FT NEAR SHORE AND
3 TO 4 OUTER WATERS WITH SOME 5 FOOTERS CREEPING IN SAT MORNING IN
NORTHERLY SURGE.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST TUESDAY FOR AMZ250-252-
     254-256.

&&

$$

NEAR TERM...DCH/MJC
SHORT TERM...HAWKINS
LONG TERM...RGZ
AVIATION...SGL












AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 408 AM EST TUE NOV 29 2011

.SYNOPSIS...
LOW PRESSURE WILL MOVE ACROSS TODAY. SOME LIGHT PRECIPITATION
TONIGHT. HIGH PRESSURE THURSDAY. MOISTURE STARVED FRONT FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
FRONT AS 0830Z HAD JUST PASSED UNI-3I2-CRW-BKW LINE...WITH BRIEF GUSTS
NEAR 25KTS ON NARROW ELEVATED CONVECTIVE BAND. HAVE OCCLUDED FRONT
CLEARING CENTRAL LOWLANDS NEXT HR AND SE OH/NORTHERN WV LOWLANDS BY
12Z. BOUNDARY TAKES ON MORE OF A NW TO SE ORIENTATION IN THE
MTNS...HENCE A FEW HRS DELAY OF FROPA FROM TO S TO N. DRY SLOT
QUICKLY WORKS IN THRU MID MORNING...EFFECTIVELY SHUTTING OFF PCPN
AFTER A COUPLE HRS POST FRONTAL RAINS. THIS MAY LINGER LONGER ACROSS
SE OH AND THE NORTHERN AREAS DUE TO LAGGING NATURE OF BOUNDARY
ACROSS MTNS AND INTO VA. RAINFALL AMOUNTS TO HALF AN INCH LOOK GOOD
WITH THIS...WITH UP TO AN INCH ALONG EAST FACING SLOPES IN MTNS.

REWORKED HRLY TEMPERATURE GRIDS TDY FROM LAV AND RUC TO REFLECT MILD
READINGS AHEAD OF BOUNDARY EARLY THIS MORNING AND DROPPING TMPS WITH FROPA.
LOOKING AT A MIDNIGHT HIGH FOR ALL PLACES...WITH TEMPS DROPPING
10-15 DEGREES WITH FROPA...AND SLOWLY FALLING THROUGH 40S TDY...WITH
30S ACROSS THE HIGH TERRAIN.

DEEP UPR LOW WILL TRACK THRU EASTERN KY THIS AFTN AND INTO THE AREA
THIS EVENING. THIS WILL INCREASE THE MOISTURE DEPTH AND LIFT TO
ALLOW LIGHT PCPN TO BREAK OUT LATE THIS AFTN ACROSS SE KY AND INTO
SOUTHERN AREAS THIS EVENING BEFORE ROTATING UP THE SPINE OF MTNS
TONIGHT. DRY SLOT MAY PIVOT ARND INTO SE OH...KEEPING AREAS ALONG
AND WEST OF OH RVR DRY INTO THE EARLY PART OF THE NIGHT...BEFORE
FILLING IN TOWARD MORNING.

AREA WILL SEE THE BEST UPR LOW HAS TO OFFER WITH RESPECT TO
MAGNITUDE OF COLD POOL ALOFT. H85 TMPS BOTTOM OUT TO ARN -5C BY 12Z
WED. A MONTH FROM NOW...THERE WOULD BE NO CONCERN ABOUT PCPN TYPE
OUTSIDE OF MTNS. HOWEVER...AS IT STANDS....BL WILL BE SLOW TO COOL
THIS EVENING. MDLS SHOW BL TEMPS AND H925 TMPS WARM ENOUGH TO KEEP
THINGS LIQUID OUTSIDE OF THE MTNS UNTIL AFTER MIDNIGHT...IF NOT A
LITTLE LONGER. EVEN IN MTNS...WHERE IT SHOULD BE COLD ENOUGH FOR
SNOW...KEEP ACCUMULATIONS TO ARND AN INCH OR SO IN THE AOA
3KFT...DUE TO VERY WET AND WARM GRND. WITH SATURATION/WEAK LIFT TO NEAR
-8C...WILL KEEP DZ MENTION OUT OF GRIDS ATTM.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
MODELS SHOW SOME LINGERING MOISTURE ON WEDNESDAY. 850 MB
TEMPERATURES ARE NOT COLD ENOUGH FOR AUTO CONVECTION IN THE LOWER
LAYER...SO WILL KEEP POPS ON THE LOW SIDE. BASED ON 850 MB
TEMPERATURES AND WITH SOME CLEARING IN THE WESTERN COUNTIES DURING
THE DAY WEDNESDAY...MOS GUIDANCE IN THE WEST LOOKS A BIT TOO COLD.
HIGH PRESSURE THEN BUILDS IN FOR THURSDAY. A MOISTURE STARVED FRONT
ARRIVES ON FRIDAY...BUT BASED ON LACK OF MOISTURE IN THE
MODELS...WILL KEEP A DRY FORECAST FOR NOW.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
HAVE GONE WITH HPC THINKING FOR THIS PART OF THE FORECAST...WHICH
LEANS TOWARDS THE ECMWF/UKMET/CANADIAN SOLUTIONS. LATEST 12 UTC
GFS MODEL HAS TRENDED TOWARDS THESE SOLUTIONS AS WELL.

A WEAK COLD FRONT WILL PUSH THROUGH THE AREA ON FRIDAY.  HOWEVER...
THE AIRMASS WILL BE QUITE DRY...SO NO PRECIP IS EXPECTED WITH THIS
FEATURE.  HIGH PRESSURE WILL THEN BE IN CONTROL FOR SATURDAY AND
SATURDAY NIGHT...BEFORE A COLD FRONT APPROACHES FROM THE WEST
SUNDAY.  THE FRONT IS EXPECTED TO BE IN THE AREA ON MONDAY.

AS A RESULT...EXPECT PRECIP CHANCES WILL INCREASE BY LATE
SUNDAY...WITH CHANCES CONTINUING THROUGH THE END OF THE PERIOD.

ONLY REAL CHANGES FROM HPC THINKING WERE THE SKY GRIDS.  FELT HPC
FORECAST INCLUDED TOO MANY CLOUDS WITH DRY FRONT ON FRIDAY...SO
TWEAKED DOWNWARD.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
LOW PRESSURE LIFTS NORTH THRU KENTUCKY TONIGHT.

OCCLUDED FRONT WORKING ACROSS THE AREA THRU 12Z. ELEVATED
CONVECTIVE BAND MAY PRODUCE BRIEF IFR CIGS/VSBY ALONG WITH GUSTS
TO 30KTS. HAVE CODED UP SOME TEMPO GROUPS TO HANDLE THIS IT MOVES
N THRU AREA 06-12Z. COULD SEE SOME HIGHER GUSTS ACROSS RIDGE TOPS
GIVEN 50KT LLVL JET.

BEHIND THE FRONT...GENERALLY MVFR CEILINGS PREVAIL WITH A COUPLE
HRS OF POST FRONTAL RAINS AS WINDS TURNING TO SOUTH SOUTHWEST. DRY
SLOT WORKS IN THRU MID MORNING...ESSENTIALLY ENDING PCPN FOLLOWING
POST FRONTAL RAINS. NOT COLD ENOUGH YET FOR SNOW EXCEPT POSSIBLY
IN SOUTHERN MOUNTAIN RIDGETOPS AFTER 14Z WITH NO ACCUMULATION.

UPR LOW ROTATES THRU THIS AFTN. MOISTURE DEPTH INCREASE UNDER COLD
POOL WHICH SHOULD ALLOW SHOWERY PCPN TO BREAK OUT ACROSS THE AREA.
AS LLVL TEMPS CONT TO COOL...A TRANSITION TO SHSN IS EXPECTED
ACROSS THE MTNS. BRING BACK MVFR CIGS THIS AFTN UNDER COLD
POOL...WITH IFR CONDITIONS MTNS AMID DEVELOPING SHSN.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...

FORECAST CONFIDENCE: HIGH TO MEDIUM.

ALTERNATE SCENARIOS: TIMING OF OCCLUDED FRONT AND LOWER CEILINGS
WITH BAND OF RAIN SHOWERS MAY VARY.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

DATE                                   TUE 11/29/11
UTC 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
EST 1HRLY       01   02   03   04   05   06   07   08   09   10   11   12
CRW CONSISTENCY  H    H    H    M    H    H    M    H    H    H    M    M
HTS CONSISTENCY  M    L    L    M    M    M    L    M    M    M    M    M
BKW CONSISTENCY  M    M    M    M    L    L    L    L    L    M    M    M
EKN CONSISTENCY  M    M    M    M    M    H    M    L    L    L    L    L
PKB CONSISTENCY  H    H    L    H    H    M    L    M    M    L    L    M
CKB CONSISTENCY  H    H    H    H    H    M    M    H    H    L    L    M

AFTER 06Z WEDNESDAY...
IFR POSSIBLE IN RAIN AND SNOW LATE TUE INTO WED...MAINLY MOUNTAINS.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...JSH/RPY/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...JSH
AVIATION...30













AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 126 AM EST TUE NOV 29 2011

.SYNOPSIS...
LOW PRESSURE TO OUR SOUTHWEST WILL MOVE TO PENNSYLVANIA BY LATE
TUESDAY. SOME LINGERING PRECIPITATION POSSIBLE WEDNESDAY...INCLUDING
SNOW SHOWERS. HIGH PRESSURE THURSDAY.

&&

.NEAR TERM /THROUGH TODAY/...
UPDATED...
FCST REMAINDER OF OVERNIGHT HRS GENERALLY ON TRACK. DID SPEED UP
FROPA A FEW HRS BASED ON LATEST RUC. FRONT AS 06Z HAD JUST PASSED
ILN-HTS-I16...WITH BRIEF GUSTS NEAR 30KTS ON NARROW ELEVATED
CONVECTIVE BAND. HAVE OCCLUDED FRONT CLEARING CENTRAL LOWLANDS BY
09Z AND SE OH/NORTHERN WV LOWLANDS BY 12Z. BOUNDARY TAKES ON MORE
OF A NW TO SE ORIENTATION IN THE MTNS...HENCE A FEW HRS DELAY OF
FROPA FROM TO S TO N. DRY SLOT QUICKLY WORKS IN THRU MID
MORNING...EFFECTIVELY SHUTTING OFF PCPN AFTER A COUPLE HRS POST
FRONTAL RAINS. THIS MAY LINGER LONGER ACROSS SE OH AND THE
NORTHERN AREAS DUE TO LAGGING NATURE OF BOUNDARY ACROSS MTNS AND
INTO VA. RAINFALL AMNTS HALF AN INCH LOOK GOOD WITH THIS...WITH UP
TO AN INCH ACROSS SE OH AND NORTHERN AREAS. COULD SEE LCLY HIGHER
AMNTS IN MTNS AND ESPECIALLY EAST FACING SLOPES.

REWORKED HRLY TMP GRIDS FROM LAV AND RUC TO REFLECT MILD READINGS
AHEAD OF BOUNDARY AND DROPPING TMPS WITH FROPA.

PREVIOUS DISCUSSION BELOW...
HI RES MODELS AND EVEN THE GFS ARE IN QUITE GOOD AGREEMENT ON THE
EVOLUTION OF THE IMPRESSIVE UPPER LOW AND ASSOCIATED SURFACE
FEATURES LIFTING NORTHEASTWARD ACROSS OUR REGION TONIGHT AND
TUESDAY. ITS ASSOCIATED SURFACE LOW OVER GEORGIA AT 18Z TODAY WILL
BECOME VERTICALLY STACKED UNDER THE UPPER LOW...DRIVING AN
OCCLUDED FRONT BEFORE IT. THIS OCCLUDED FRONT WILL LIKELY REACH A
DAY-HTS-BLF LINE AROUND 08Z...THEN EXIT INTO PENNSYLVANIA BY 14Z
TUESDAY. SOME INTENSIFICATION OF THIS SYSTEM IS NOTED ON ALL THE
MODELS.

THIS SCENARIO HAS A WELL SUPPORTED AND DYNAMIC OCCLUDED FRONT MOVING
ACROSS US TONIGHT. ONE IMPORTANT FEATURE WILL BE THE STRENGTHENING
SOUTHEASTERLY FLOW AHEAD OF THE FRONT...WITH 850 MB SPEEDS OF AROUND
55 KTS. HOWEVER...NOCTURNAL TIMING OF THE WINDS AND WARM ADVECTION
SUGGESTS WINDS STRONG ENOUGH FOR WIND ADVISORY CRITERIA WILL STAY
MAINLY ON THE MOUNTAIN RIDGETOPS. THUS...WILL HIGHLIGHT STRONG AND
GUSTY WINDS FOR RIDGETOPS AND NOT GO WITH AN ADVISORY AT TIME.
SECOND FEATURE WILL BE A WELL ORGANIZED BAND OF HEAVIER RAIN SHOWERS
PRECEDING THE OCCLUDED FRONT...ESPECIALLY EAST FACING SLOPES OF
MOUNTAINS AND WEST OF THE OHIO RIVER WHERE DOWNSLOPING IS LESS OF A
FACTOR. EXPECT RAINFALL AMOUNTS WITH THE FRONT TO RANGE FROM A HALF
TO THREE QUARTERS OF AN INCH IN THE RELATIVE RAIN SHADOW JUST WEST
OF THE MOUNTAINS...TO POSSIBLY AN INCH AND A QUARTER OVER SOUTHEAST
OHIO AND PARTS OF THE MOUNTAINS. DO NOT THINK THIS IS ENOUGH TO GO
WITH A FLOOD WATCH AS PREVIOUS 24 HOUR RAINS HAVE BEEN HALF AN INCH
TO AN INCH AT BEST OVER SOUTHEAST OHIO AND LITTLE ELSEWHERE.

BEHIND THE FRONT WILL BE A RELATIVE DRY SLOT WITH PERHAPS SCATTERED
LIGHT RAIN SHOWERS. LACK OF LOW LEVEL COLD AIR SUGGESTS ANY SHOWERS
BEHIND THE FRONT WILL MAINLY REMAIN AS LIQUID. THERE MAY BE SOME WET
FLAKES OF SNOW OVER THE HIGHER MOUNTAINS LATER ON TUESDAY AS THIS
IS WHERE THE COLD AIR ALOFT WILL ARRIVE FIRST. NO ACCUMULATION.

LOOK FOR TEMPS TO ONLY SLOWLY DROP WITH THE PRECIP TONIGHT...THEN
REMAIN RELATIVELY STEADY TO ONLY A SLIGHT RECOVERY BEHIND THE FRONT
ON TUESDAY. COLD CORE ALOFT WILL BRING AN INCREASED AREA OF SHOWERS
MAINLY OVER EASTERN SECTIONS TUESDAY AFTERNOON...AND HAVE RAISED
POPS ACCORDINGLY. STILL...DOWNPLAYING SNOW TUESDAY DUE TO RELATIVELY
WARM BOUNDARY LAYER TEMPS.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY/...
STRONG LOW ALOFT DEEPENS AS IT LIFTS NORTH TUESDAY NIGHT WITH A
CHILLIER AIRMASS NOW HAVING FILLED IN. UPPER LEVELS WILL HAVE SINCE
DRIED OUT...LEAVING LOW AND MID LEVEL MOISTURE AND WEAK FORCING
UNTIL THE SYSTEM CLEARS THE CWA. BULK OF THE LIQUID EQUIVALENT
PRECIPITATION ACCUMULATIONS SHOULD BE OVER BY TUESDAY NIGHT AND
WEDNESDAY. SNOW SHOWERS NOT OUT OF THE QUESTION IN THE LOWLANDS
TUESDAY NIGHT...BUT UNLIKELY TO SEE ANY ACCUMULATIONS HERE AS A
TRANSITION TO LIQUID IS LIKELY WEDNESDAY. IN THE HIGHER ELEVATIONS
OF THE EASTERN MOUNTAINS WHERE THE TEMPERATURES WILL HAVE A BETTER
CHANCE OF STAYING BELOW FREEZING...LIGHT ACCUMULATIONS ARE POSSIBLE
THROUGH THE DURATION OF THE SHORT TERM FORECAST.

PRESSURE RISES COMMENCE WEDNESDAY NIGHT INTO THURSDAY WITH HIGH
PRESSURE SETTLING IN...BUT THE NORTHWEST FLOW SHOULD KEEP THE LIGHT
SNOW SHOWERS GOING IN THE NORTHEAST MOUNTAINS UNTIL 06Z THURSDAY.
CLEAR SKIES FOLLOW FOR THE BULK OF THURSDAY WITH THE HIGH
PRESSURE...LESS SOME CIRRUS ADVECTION LATER IN THE DAY. COULD SEE
SOME OF THE COLDEST AIR OF THE SEASON AREA WIDE WEDNESDAY NIGHT WITH
LOW TO MID 20S AREA WIDE...AND EVEN TEENS IN THE MOUNTAINS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
HAVE GONE WITH HPC THINKING FOR THIS PART OF THE FORECAST...WHICH
LEANS TOWARDS THE ECMWF/UKMET/CANADIAN SOLUTIONS. LATEST 12 UTC
GFS MODEL HAS TRENDED TOWARDS THESE SOLUTIONS AS WELL.

A WEAK COLD FRONT WILL PUSH THROUGH THE AREA ON FRIDAY.  HOWEVER...
THE AIRMASS WILL BE QUITE DRY...SO NO PRECIP IS EXPECTED WITH THIS
FEATURE.  HIGH PRESSURE WILL THEN BE IN CONTROL FOR SATURDAY AND
SATURDAY NIGHT...BEFORE A COLD FRONT APPROACHES FROM THE WEST
SUNDAY.  THE FRONT IS EXPECTED TO BE IN THE AREA ON MONDAY.

AS A RESULT...EXPECT PRECIP CHANCES WILL INCREASE BY LATE
SUNDAY...WITH CHANCES CONTINUING THROUGH THE END OF THE PERIOD.

ONLY REAL CHANGES FROM HPC THINKING WERE THE SKY GRIDS.  FELT HPC
FORECAST INCLUDED TOO MANY CLOUDS WITH DRY FRONT ON FRIDAY...SO
TWEAKED DOWNWARD.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
LOW PRESSURE LIFTS NORTH THRU KENTUCKY TONIGHT.

OCCLUDED FRONT WORKING ACROSS THE AREA THRU 12Z. ELEVATED
CONVECTIVE BAND MAY PRODUCE BRIEF IFR CIGS/VSBY ALONG WITH GUSTS
TO 30KTS. HAVE CODED UP SOME TEMPO GROUPS TO HANDLE THIS IT MOVES
N THRU AREA 06-12Z. COULD SEE SOME HIGHER GUSTS ACROSS RIDGE TOPS
GIVEN 50KT LLVL JET.

BEHIND THE FRONT...GENERALLY MVFR CEILINGS PREVAIL WITH A COUPLE
HRS OF POST FRONTAL RAINS AS WINDS TURNING TO SOUTH SOUTHWEST. DRY
SLOT WORKS IN THRU MID MORNING...ESSENTIALLY ENDING PCPN FOLLOWING
POST FRONTAL RAINS. NOT COLD ENOUGH YET FOR SNOW EXCEPT POSSIBLY
IN SOUTHERN MOUNTAIN RIDGETOPS AFTER 14Z WITH NO ACCUMULATION.

UPR LOW ROTATES THRU THIS AFTN. MOISTURE DEPTH INCREASE UNDER COLD
POOL WHICH SHOULD ALLOW SHOWRY PCPN TO BREAK OUT ACROSS THE AREA.
AS LLVL TEMPS CONT TO COOL...A TRANSITION TO SHSN IS EXPECTED
ACROSS THE MTNS. BRING BACK MVFR CIGS THIS AFTN UNDER COLD
POOL...WITH IFR CONDITIONS MTNS AMID DEVELOPING SHSN.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...

FORECAST CONFIDENCE: HIGH TO MEDIUM.

ALTERNATE SCENARIOS: TIMING OF OCCLUDED FRONT AND LOWER CEILINGS
WITH BAND OF RAIN SHOWERS MAY VARY.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

DATE                                   TUE 11/29/11
UTC 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
EST 1HRLY       01   02   03   04   05   06   07   08   09   10   11   12
CRW CONSISTENCY  H    H    H    M    H    H    M    H    H    H    M    M
HTS CONSISTENCY  M    L    L    M    M    M    L    M    M    M    M    M
BKW CONSISTENCY  M    M    M    M    L    L    L    L    L    M    M    M
EKN CONSISTENCY  M    M    M    M    M    H    M    L    L    L    L    L
PKB CONSISTENCY  H    H    L    H    H    M    L    M    M    L    L    M
CKB CONSISTENCY  H    H    H    H    H    M    M    H    H    L    L    M

AFTER 06Z WEDNESDAY...
IFR POSSIBLE IN RAIN AND SNOW LATE TUE INTO WED...MAINLY MOUNTAINS.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...26/JSH/JMV
NEAR TERM...JMV/30
SHORT TERM...26
LONG TERM...JSH
AVIATION...30









AREA FORECAST DISCUSSION

NWS CHEYENNE WY

 1015 PM MST MON NOV 28 2011

.AVIATION...06Z TAFS

LATEST SATELLITE IMAGERY CONTINUES TO SHOW LOW CLOUDS NOT
DEVELOPING EAST OF THE LARAMIE RANGE WHICH IS SUPPORTED BY LATEST
HRRR GUIDANCE. CONFIDENCE HIGH THAT LOW CEILINGS WILL PROBABLY NOT
DEVELOP OVERNIGHT FOR MOST LOCATIONS. THE EXCEPTION BEING RAWLINS
WHERE HRRR SHOWING SOME PATCHY IFR CONDITIONS DEVELOPING AROUND
THE 08Z-09Z TIME FRAME. GOING TO BE A REAL HIT/MISS TYPE SCENARIO
OUT THAT WAY...SO OPTED FOR AN MVFR FORECAST FROM 08Z THROUGH
SUNRISE.

CONDITIONS REALLY CHANGE WEDNESDAY NIGHT INTO THURSDAY AS A STRONG
COLD FRONT PUSHES INTO SOUTHEAST WYOMING. SNOW EXPECTED ALONG WITH
STRONG NORTH WINDS LATE WEDNESDAY AFTERNOON THROUGH THURSDAY
MORNING.

CLAYCOMB


&&

PREV DISCUSSION... /ISSUED 256 PM MST MON NOV 28 2011/

SHORT TERM...TONIGHT THROUGH WEDNESDAY...

CURRENTLY COLD FRONT ON THE DOORSTEP OF KCYS. WINDS HAVE SHIFTED
TO THE NORTHWEST AND ARE GUSTING INTO THE MID 30S BUT TEMPERATURE
REMAINING STEADY SO FAR. LOOKING AT PRESSURE CHANGE AND
OBSERVATIONS LOOKS LIKE THE FRONT HAS ALSO MOVED THROUGH THE
SOUTHERN PANHANDLE. RADAR REMAINED PPINE WITH THE FRONT AND
SATELLITE SHOWED MAINLY MID CLOUDS.

THIS MORNINGS UPPER PACKAGE PLENTY OF WARM AIR AHEAD OF THE SYSTEM
THAT IS MOVING THROUGH THE AREA. FLOW WAS GENERALLY FROM THE WEST
WITH LITTLE MOISTURE.

FORECAST PROBLEM FOR THIS PACKAGE WILL BE WINDS AND TEMPERATURES.

LOOKS LIKE HIGH PRESSURE WILL SETTLE ACROSS THE CWA TONIGHT BEHIND
THE FRONT AND GUSTY WINDS WILL PERSIST UNTIL AFTER SUNSET. TUESDAY
SHOULD BE DRY AND COOLER THAN TODAY BUT ANOTHER SYSTEM MOVING
MOVING INTO THE PACIFIC NORTHWEST WILL QUICKLY BRING THE WINDS
AROUND AND TEMPER SIGNIFICANT COOLING. THE NEXT SYSTEM WILL
CONTINUE TO APPROACH AND ON WEDNESDAY WILL SEE CLOUDS INCREASING.
BY WEDNESDAY AFTERNOON COULD POSSIBLY START TO SEE SOME
PRECIPITATION IN THE HIGH COUNTRY AND IN THE NORTHERN CWA BUT THE
SNOW SHOULD BEGIN IN EARNEST AFTER 01/00Z.

FOR THE SHORT TERM TEMPERATURES LOOK TO BE AROUND NORMAL.

LONG TERM...WEDNESDAY NIGHT-MONDAY
THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE SNOW POTENTIAL
ON WEDNESDAY NIGHT INTO THURSDAY AND HOW COLD TEMPERATURES WILL BE
THROUGH THE WEEK.

LATEST WATER VAPOR LOOP WAS SHOWING TWO DISTINCT UPPER LEVEL
VORTICITY LOBES MOVING THROUGH THE EASTERN PACIFIC. THE FIRST WAVE
WAS AROUND 42 DEG N AND 155 DEG W...WHILE THE TRAILING WAVE WAS 44
DEG N AND 176 N. THE MODELS SEEM TO BE IN FAIRLY GOOD AGREEMENT
IN SHOWING THE FIRST WAVE DIGGING ACROSS THE SOUTHERN ROCKIES
DURING THE NEXT COUPLE OF DAYS WHICH WILL CAUSE THE FLOW TO SPLIT AS
THE NEXT WAVE SKIRTS ACROSS THE NORTHERN ROCKIES LATER IN THE WEEK.

THE FIRST UPPER LEVEL WAVE SHOULD BEGIN TO IMPACT THE AREA
BEGINNING LATE WEDNESDAY AFTERNOON AND CONTINUING UNTIL THURSDAY
AFTERNOON. THIS WAVE WILL HAVE AID FROM THE RIGHT ENTRANCE REGION OF
THE UPPER LEVEL JET...BUT IT WILL BE RATHER SHORT LIVED. THE MODELS
ARE SHOWING SOME WEAK POTENTIAL INSTABILITY BETWEEN 700-500MB NEAR
CASPER AROUND 06Z. OTHERWISE...THIS SYSTEM SHOULD HAVE DEEP ENOUGH
MOISTURE AND LIFT BEHIND THE FRONT TO PRODUCE SOME LIGHT TO MODERATE
SNOWFALL BEGINNING LATE WEDNESDAY AFTERNOON IN THE NORTHERN HALF OF
THE FORECAST AREA WITH THIS SNOW SPREADING INTO THE SOUTHERN HALF OF
THE FORECAST AREA WEDNESDAY NIGHT. SNOWFALL ACCUMULATIONS SHOULD
GENERALLY BE AROUND 2-4 INCHES WITH HIGHER AMOUNTS IN THE MOUNTAINS
WHERE THE SNOW RATIOS WILL BE A LITTLE GREATER. THE MAIN LIMITATION
FOR MUCH IN THE WAY OF ACCUMULATION WILL BE THE SHORT LIVED NATURE OF
THE HEAVIER SNOWFALL. THIS WILL MOST LIKELY TAKE PLACE WEDNESDAY
EVENING WHEN THE COLD AIR AIR ADVECTION WILL BE THE STRONGEST WITH
SOME WEAK SHORT LIVED MID LEVEL FRONTOGENISIS (700-500MB) POSSIBLE.
THE SNOW SHOULD BEGIN TO TAPER OFF FROM NORTH TO SOUTH ON THURSDAY.

TEMPERATURES WILL TURN SHARPLY COLDER WITH GUSTY NORTH WINDS
AT 30 TO 40 MPH POSSIBLE ON WEDNESDAY EVENING INTO THURSDAY
MORNING. TEMPERATURES WILL ALSO NOT BUDGE MUCH ON THURSDAY WITH
HIGHS GENERALLY IN THE TEENS AND LOW 20S WHICH WILL ONLY BE A COUPLE
OF DEGREES WARMER THAN MORNING LOWS. MEANWHILE...LOWS ON THURSDAY
NIGHT COULD BE QUITE CHILLY (SINGLE DIGITS TO BELOW ZERO IN THE
VALLEYS) DUE TO THE 1040MB SURFACE HIGH SETTLING OVER THE AREA. WE
REALLY BACKED OFF ON HIGHS COMPARED TO THE GUIDANCE NUMBERS FOR
THIS TIME FRAME.

FRIDAY-MONDAY:
THE NEXT CONCERN DURING THIS TIME FRAME...WILL BE THE ARRIVAL OF
THE NEXT WAVE ON SATURDAY INTO SUNDAY. THE MAIN CONCERN WITH THIS
SYSTEM WILL BE HOW MUCH THIS TROF WILL AMPLIFY AS IT APPROACHES
THE CANADIAN ROCKIES. THIS WILL DETERMINE HOW MUCH COLD AIR SPILLS
INTO THE REGION THIS WEEKEND. IF THIS TROF DOES AMPLIFY...WE COULD
SEE ARCTIC AIR SPILLING INTO THE AREA BEGINNING SATURDAY AND
CONTINUING THROUGH MONDAY. SNOW CHANCES LOOK TO BE FAIRLY SMALL AT
THIS TIME WITH VERY LITTLE IF ANY ACCUMULATION. OF COURSE...THIS
WILL BE DEPENDENT ON HOW MUCH MOISTURE WILL BE AVAILABLE.

&&
FIRE WEATHER...
WIND SPEEDS WILL CONTINUE TO DIMINISH TONIGHT. OTHERWISE...THE
ONLY CONCERN WILL BE THE HIGH WIND POTENTIAL ON WEDNESDAY NIGHT
INTO THURSDAY...BUT THE PRECIPITATION CHANCES WILL BE QUITE HIGH
WHICH WILL LIMIT FIRE WEATHER CONCERNS.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.

&&

$$

SHORT TERM...GRIFFITH
LONG TERM/AVIATION...REC







AREA FORECAST DISCUSSION

NWS NORTHERN INDIANA

 1000 AM EST TUE NOV 29 2011

.HYDROLOGY...
HAVE UPDATED THE FLOOD WATCH TO AN AREAL FLOOD WARNING FOR THE
ENTIRE AREA. SATURATED GROUND FROM EARLIER RAINFALL HAS CAUSED
THE ADDITIONAL RAINFALL TO RUNOFF AND PRODUCE SOME FLOODING OF
ROADS AND RAPID RISES ON STREAMS. ADDITIONAL RAINFALL OF 1 TO
2 INCHES AND EVEN MELTED SNOW LATER TODAY IS EXPECTED TO CAUSE
WIDESPREAD AREAL FLOODING LATER TODAY.

&&

.PREV DISCUSSION... /ISSUED 446 AM EST TUE NOV 29 2011/

SHORT TERM...
DYNAMIC/IMPRESSIVE SRN STREAM WAVE CONTS TO WRAP UP ACRS WRN TN
EARLY THIS MORNING W/MATURE INTENSE TROWAL TO ITS NORTH. WIDESPREAD
MOD-HVY RAIN WAS ONGOING ACRS MUCH OF THE CWA W/HEAVIEST BANDED PCPN
ORIENTED SW-NE THROUGH ACRS THE NW HALF.

COMPLEX/MULTI-FACETED FCST GOING FWD FOR TDA AND TONIGHT. COLD CORE
LOW OVR WRN TN WILL LIFT OUT NEWD THROUGH WRN OH AND DEEPEN THROUGH LT
AFTN IN RESPONSE TO UPSTREAM NRN STREAM TROUGH MAKING QUICK EWD
PROGRESS ACRS THE UPR MIDWEST. IN FACT FULL GAMUT OF 00Z GUIDANCE
TRENDED QUICKER W/RAIN-SNOW CHG OVR AND IN LIFTING THIS DEEP SYS OUT
W/VAPOR INDICATING FTR BEGINNING TO GET PICKED UP W/RAIN CHG TO SNOW
NOW INTO SE MO/SRN IL. HWVR MODEL INTRICACIES ABOUND ESP W/TIMING OF
CHG OVR AND PLACEMENT OF MOST INTENSE PORTION OF MID LVL DEFORMATION
BAND. EARLY CONJECTURE HERE GIVES A NOD TO MODELS THAT IMPLY A
FASTER CHG OVR/WWD PLACEMENT GIVEN NRN STREAM TROUGH IS SLIGHTLY EWD
OF PRIOR 03Z RUC GUIDANCE AND QUICKER W/INFILTRATION OF LL CAA WING
ADVTG SWWD WITHIN RAPIDLY INCREASING LL AGEOSTROPHIC FLW THROUGH MID
MORNING W/CORRESPONDING SUBSEQUENT FASTER ARRIVAL OF COLD POCKET
ALOFT FULLY ANTICIPATED. THIS WILL ESSENTIALLY OVERWHELM TROWAL WARM
NOSE AND LEAD TO RAPID MIX TWD HEAVY SNOW BTWN 17-20Z SW-NE ACRS THE
WRN 2/3RDS OF CWA TIED TO MAXIMIZING VERTICAL ASCENT WITHIN MID LVL
DEFORMATION ZONE ALG NOSE OF ASCENDING WARM CONVEYOR BELT. AND THUS
THE CHALLENGE OF THE DAY IS WHAT TO DO W/SNOW AMOUNTS.

BLENDED MULTI-MODEL QPF WAS UTILIZED TO DAMPEN MUCH HIGHER HIGHRES
GUIDANCE WHILE OFFSETTING LWR BOUND SPECTRAL GUIDANCE. THIS GIVES SIMILAR
AMOUNTS W/HPC YET PREFER A HEDGE WWD PLACEMENT OF MORE SIG SNOW BAND.
THROUGH 05Z...5 INCH AMOUNTS HAVE BEEN REPORTED ACRS WRN TN. HIGHER
AMOUNTS ARE CERTAINLY PLAUSIBLE...EVEN LIKELY...ESP CONSIDERING ALL
HIGHRES SOLUTIONS IMPLYING LOW TOPPED CONVN THIS AFTN WITHIN MID LVL
DEFORMATION ZONE ACRS NRN IN/SRN MI AND SREF PROBS OF 1+ INCH/HR
SNOW RATES EXCEED 70% THIS AFTN AND EVENING AND 2+ PROBS EXCEEDING
30%. NR TERM 06Z RUNS OF HRRR/RUC BOTH CONFIRMING FASTER CHG OVR AND
DVLPMNT OF 40+ DBZ RTNS THIS AFTN WITHIN DEFORMATION ZONE THUS
W/GROWING LIKELIHOOD OF EXTREME SNOWFALL RATES...POTENTIAL ACCUMS
MAY BE SIGNIFICANTLY HIGHER THAN CURRENTLY SHOWN W/SOME EXPERIMENTAL
HIGHRES SNOW ALGORITHMS INDICATING A FOOT PLUS ALG A WARSAW TO
KALAMAZOO LINE. THUS GIVEN TIMING OF CHG OVR WILL LIKELY OCCUR WELL
BFR THE AFTN COMMUTE AND POTENTIAL FOR SHORT DURATION/6+ INCH SNOW
AMOUNTS WILL HOIST A WINTER STORM WATCH FROM EARLY AFTN THROUGH 06Z
FOR GENERALLY THE WRN 2/3RDS OF CWA. FRINGE COUNTIES ALG BOTH SIDES
ARE PROBLEMATIC ESP FAR NW WHERE DVLPMNT OF STG ISOLLABARIC FLW XPCD
THIS AFTN OFF LK MI SHLD MODIFY THE BNDRY LYR SUFFICIENTLY TO
PROMOTE MORE OF A MIX AND NEGLIGIBLE ACCUMS...AND EAST W/SPECTRAL
MODEL CONSENSUS MUCH SLWR LIFTING INTENSE DEFORMATION ZONE BAND OUT
THIS EVENING. THUS THE NOD TWD A WATCH VS WARNING AT THIS POINT AND
IN LIGHT OF CHG OVR TIMING UNCERTAINTIES STILL.

REGARDLESS WHAT IS LEFT OF MID LVL DEFORMATION ZONE...LEFTOVERS
WILL RAPIDLY LIFT OUT/BREAK DOWN TWD LT EVENING/EARLY MORNING W/SNOW
ENDING QUICKLY W-E. CLDS SHLD HOLD THOUGH WITHIN LL THERMAL TROUGH
AND FLW NW LL FLW OFF THE LAKE AND WILL HOLD W/WARMER MIN BLEND
OVERNIGHT.

LONG TERM...WEDNESDAY THROUGH MONDAY

ONLY MINOR TWEAKS MADE TO THE FCST AS LATEST GUIDANCE IS SIMILAR TO
PREVIOUS GUIDANCE AND INHERITED GRIDS. A REPRIEVE FROM THE WET/WHITE
WX ANTICIPATED WEDNESDAY INTO THURSDAY AS HEIGHT RISES/SHORTWAVE
RIDGING ENSUES BEHIND TODAY`S POWERHOUSE SYSTEM. WEDNESDAY WILL
START OUT MAINLY CLOUDY (ESPECIALLY EAST) AND BREEZY...WITH CLEARING
AND DIMINISHING WINDS BY AFTERNOON. WAA ALOFT WILL BE OFFSET BY
SHALLOW MIXING AND SNOW COVER OVER MUCH OF THE AREA. WITH THIS OPTED
FOR COOLER GUIDANCE EACH DAY.

MORNING WATER VAPOR LOOP SHOWS A POTENT NORTHERN STREAM SHORTWAVE
TROUGH NEAR 145W IN THE NE PAC. THIS FEATURE WILL DIG INTO THE
WESTERN CONUS BY WEDNESDAY...WITH ENSEMBLES CONTINUING TO INDICATE
AN UPPER TROUGH FRACTURE BY THIS TIME. THE MOISTURE STARVED AND
SOMEWHAT SHEARED NRN PIECE OF THIS WAVE LOOKS TO PROPAGATE RAPIDLY
EWD THROUGH THE GREAT LAKES BY THURSDAY NIGHT/FRIDAY MORNING.
ECMWF/GFS 5-3H Q-VECTOR PROGS POINT TO A BRIEF PERIOD OF LARGE SCALE
ASCENT BYPASSING MAINLY TO THE NORTH DURING THIS TIME. AS A
RESULT...NOT EXPECTING MUCH IN THE WAY OF PRECIP BEHIND THE
ATTENDANT CDFNT LOCALLY. OPTED TO LOWER POPS TO SLIGHT CHC FOR THE
POSSIBILITY OF A FEW LGT SNOW SHOWERS.

GREATER AMPLIFICATION OF A NE PAC RIDGE WILL SUPPORT DOWNSTREAM
AMPLIFICATION THIS WEEKEND...ALLOWING ANOTHER POSITIVELY TILTED NRN
STREAM UPPER TROUGH TO DIG INTO THE CENTRAL CONUS. THIS GREATER
AMPLIFICATION WILL HELP FORCE A SRN STREAM LEAD SHORTWAVE NEWD
TOWARDS THE GREAT LAKES BY SATURDAY NIGHT/SUNDAY...BRINGING WITH IT
A BETTER CHC FOR MORE WIDESPREAD PRECIPITATION BY THIS TIME. AS
EXPECTED THIS FAR IN ADVANCE...STILL LOW CONFIDENCE WRT TO DETAILS
(TRACK/TIMING/AMPLITUDE/ETC) SO WILL RETAIN CHC POPS AND FAVOR THE
MORE CONSISTENT ECMWF WHICH HINTS AT A FARTHER NW TRACK AND MAINLY
RAIN LOCALLY. OTHERWISE...TEMPS FOR THE ENTIRE PERIOD ARE FCST TO
GENERALLY BE AT OR BELOW NORMAL.

AVIATION...
XPC IFR CIGS TO HOLD THROUGH THE PD W/GENERALLY MVFR VSBYS
PREFERRED IN RAIN UNTIL THIS AFTN WHEN CHG OVR TO SNOW OCCURS. PD
OF LIFR CONDS LIKELY LT THIS AFTN/EARLY EVENING IN +SN W/LONGER
DURATION XPCD AT KSBN. WILL ATTEMPT SOME REFINED TIMING W/12Z ISSUANCE.
OTHERWISE GRADIENT WINDS ARE COMING UP NOW W/SFC GUSTS AOA 25KTS
THROUGH EARLY EVENING.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM 1 PM EST /NOON CST/ THIS AFTERNOON
     THROUGH LATE TONIGHT FOR INZ004>009-012>018-020-022>025-032.

MI...WINTER STORM WATCH FROM 1 PM EST THIS AFTERNOON THROUGH LATE
     TONIGHT FOR MIZ078>081.

OH...WINTER STORM WATCH FROM 1 PM EST THIS AFTERNOON THROUGH LATE
     TONIGHT FOR OHZ001.

LM...GALE WARNING UNTIL 10 AM EST WEDNESDAY FOR LMZ043-046.

&&

$$

SHORT TERM...T
LONG TERM...STEINWEDEL
AVIATION...T






AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 941 AM EST TUE NOV 29 2011

.SYNOPSIS...
AS A COLD FRONT MOVES THROUGH LATER TODAY...RAIN WILL DIMINISH AND
COLDER WEATHER WILL ARRIVE. SNOW SHOWERS ARE POSSIBLE TONIGHT
INTO WEDNESDAY. DRY WEATHER IS SLATED FOR THE LATTER PART OF THE
WEEK UNDER SEASONAL TEMPERATURES.

&&

.NEAR TERM /THROUGH TONIGHT/...
PLUME OF MOISTURE ASSOCIATED WITH THE WARM CONVEYOR BELT EXTENDS ALL
ALL THE WAY TO THE ATLANTIC...WHICH IS BRINGING RAIN /AT TIMES
MODERATE/ TO LOCATIONS EAST OF THE OHIO RIVER. AS THE UPPER LEVEL
CYCLONE CONTINUES ITS NE MOVEMENT...THE AXIS OF RAIN WILL SHIFT NE
AS WELL THIS AFTERNOON. QPF AMOUNTS WILL BE AROUND 0.50 INCHES
WITH THIS BAND...BUT STILL DO NOT FEEL THIS WILL YIELD ANY HIGH
WATER.

WITH THE LOW EXPECTED TO TRACK ACROSS EASTERN OHIO UP TO LAKE
ERIE...DRY SLOT WILL PASS DURING THE EVENING...LEAVING EASTERN
OHIO AND NORTHERN WV PANHANDLE DRY FOR A PERIOD OF TIME.
HOWEVER...MODELS ARE IN AGREEMENT THAT ANOTHER PIECE OF ENERGY
WILL RIDE UP THE RIDGES DURING THE EVENING HOURS. ALSO CAN NOT
RULE OUT A PERIOD OF DRIZZLE AS THE MID AND UPPER MOISTURE PULL
AWAY.

TEMPERATURES ACROSS THE RIDGES WILL BE CRITICAL DURING THIS TIME
PERIOD: IF TEMPS DROP LOW ENOUGH...THERE IS THE POTENTIAL TO DROP
A QUICK 1-3 INCHES OF SNOW DURING THIS PERIOD OF TIME.

CURRENT FORECAST ANTICIPATES THAT THIS PRECIP WILL FALL AS RAIN
DURING THE EVENING. AFTER MIDNIGHT...MORE MOISTURE WILL BEGIN TO
MOVE IN FROM THE WEST...ALLOWING FOR SOME SHOWERS TO RETURN TO THE
ENTIRE FORECAST AREA. ALONG THE RIDGES...ABOUT AN INCH OF SNOW IS
EXPECTED AFTER MIDNIGHT. OUTSIDE OF THE RIDGES...A MIX OR
CHANGEOVER TO SNOW CERTAINLY CANNOT BE RULED OUT...BUT
TEMPERATURES ARE EXPECTED TO ONLY DROP TO THE MID 30S
OVERNIGHT...LIMITING ACCUMULATION.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
LOW PRESSURE CENTER SHOULD BE NORTH OF LAKE ONTARIO BY WEDNESDAY
MORNING...AND THE CENTER WILL CONTINUE ITS TREK TO THE NORTHEAST.
WINDS SHOULD BECOME FAVORABLE FOR SOME LAKE EFFECT/UPSLOPE FLOW FOR
SEVERAL HOURS ON WEDNESDAY...AND WITH REMAINS OF DEFORMATION ZONE
MOVING TO THE EAST...HAVE INCREASED POPS ACROSS MOST LOCATIONS
DURING THE DAY. HAVE ALSO BUMPED UP POPS A BIT WEDNESDAY NIGHT FOR
THE RIDGES AS UPSLOPE WINDS SQUEEZE REMAINING MOISTURE OUT. WITH
MUCH COLDER TEMPERATURES WEDNESDAY...REMAINS TO BE SEEN IF SHOWERS
WILL REMAIN SNOW...OR CHANGEOVER TO RAIN. HIGH PRESSURE WILL MOVE
INTO THE REGION BY THURSDAY...ALLOWING FOR DRY CONDITIONS THAT DAY
INTO FRIDAY. ALTHOUGH THERE WILL BE SOME SLIGHT MODERATION IN
TEMPS...HIGHS WILL REMAIN A COUPLE OF DEGREES BELOW NORMAL.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODELS HAVE BEEN CONSISTENT WITH A WEAK COLD FRONT CLIPPING THE
AREA LATE FRIDAY/FRIDAY NIGHT. WITH LIMITED MOISTURE...WILL USE
LOW END CHANCE POPS. DRY AND CHILLY CONDITIONS ARE EXPECTED FOR
SATURDAY...WITH A SMALL CHANCE OF PRECIP COMING IN FOR LATE SUNDAY
AND MONDAY.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
BLEND OF RECENT SURFACE AND RADAR DATA ALONG WITH HRRR AND NAM MODEL
OUTPUT SHOW COLD FRONTAL BAND OF RAIN MOVING NORTHEASTWARD THROUGH
THE UPPER OHIO VALLEY THROUGH EARLY AFTERNOON.

THE MAIN AVIATION CONCERN WILL BE THE WIND. WINDS FROM 2 KFT AGL UP
WILL BE 40 KTS, WITH RAIN NOW OCCURRING, THE FAST WINDS CAN MIX
TO THE SURFACE TO CAUSE GUSTS OF 25-30 KTS, AS EVIDENCED BY RECENT
SURFACE DATA OVER THE MOUNTAINS, FOR EXAMPLE KEKN, K2G4, KJST, AND
KDUJ.

WITHIN THE FRONTAL RAIN BAND, FLIGHT CONDITIONS WILL DETERIORATE TO
MVFR THIS MORNING WITH SHORT-LIVED IFR POSSIBLE IN HEAVIER RAINFALL.

WITH PASSAGE OF THE COLD FRONT TOWARD MIDDAY, SURFACE WINDS WILL
SHIFT INTO THE SOUTHWEST WITH GUSTS TO 20-25 KTS. POST FRONTAL
CONDITIONS THIS AFTERNOON AND TONIGHT WILL BE MAINLY MVFR IN
INTERMITTENT SHOWERS. THERE CAN BE A DRY SLOT WITH VFR CONDITIONS
LATE AFTERNOON INTO EVENING, FOLLOWED BY RENEWED SHOWERS TONIGHT DUE
TO TROWAL DYNAMICS.

SURFACE TEMPERATURES WILL DROP INTO THE 30S, BUT NAM MODEL PROFILES
SUGGEST CLOUDS MAY BE TOO SHALLOW, WEST OF THE MOUNTAINS, TO PRODUCE
A CHANGE TO SNOW SHOWERS AS CLOUD TOP TEMPERATURES CAN BE WARMER
THAN THE M10C NEEDED FOR ICE NUCLEI INITIATION. NEAR THE MOUNTAINS,
CLOUDS CAN BE TALLER AND HENCE HAVE COLDER CLOUD TOPS MAKING SNOW
FORMATION POSSIBLE.

OUTLOOK...WEDNESDAY THROUGH SATURDAY....
NO WIDESPREAD IFR WEATHER IS PREDICTED.

&&

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

&&

$$







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 707 AM EST TUE NOV 29 2011

.SYNOPSIS...
AS A COLD FRONT MOVES THROUGH TODAY...RAIN WILL DIMINISH AND
COLDER TEMPERATURES WILL ARRIVE. SNOW SHOWERS ARE POSSIBLE TONIGHT
INTO WEDNESDAY. DRY WEATHER IS SLATED FOR THE LATTER PART OF THE
WEEK UNDER SEASONAL TEMPERATURES.

&&

.NEAR TERM /THROUGH TONIGHT/...
LOW PRESSURE CURRENTLY OVER SOUTHERN OHIO IS PROJECTED TO MOVE TO
THE NORTHEAST DURING THE DAY. ASSOCIATED COLD FRONT CURRENTLY WRAPS
TO THE SOUTHEAST FROM THE LOW...WRAPPING BACK INTO THE CAROLINAS.

RAIN WILL OVERSPREAD THE REGION FROM SOUTH TO NORTH AS THE LOW
APPROACHES...WITH THE HEAVIEST RAINFALL OCCURRING AS THE FRONT MOVES
THROUGH LATE MORNING/EARLY AFTERNOON.

BASED ON RECENT NAM MODEL OUTPUT AND UPPER AIR DATA, EXPECT
SURFACE WINDS TO GUST TO 25-30 MPH AT TIMES.

TEMPERATURES REMAIN QUITE WARM IN ADVANCE OF THE FRONT...WITH
OVERNIGHT TEMPERATURES WELL ABOVE CLIMATOLOGICAL HIGH TEMPERATURES
FOR LATE NOVEMBER. ALTHOUGH SOME BRIEF WARMING IS POSSIBLE THIS
MORNING...TEMPERATURES WILL FALL DURING THE DAY AS THE COLD FRONT
PASSES.

WITH THE LOW EXPECTED TO TRACK ACROSS EASTERN OHIO UP TO LAKE
ERIE...DRY SLOT COULD THEN PASS THROUGH DURING THE EVENING
HOURS...LEAVING EASTERN OHIO AND NORTHERN WV PANHANDLE DRY FOR A
PERIOD OF TIME. HOWEVER...MODELS ARE IN AGREEMENT THAT ANOTHER
PIECE OF ENERGY WILL RIDE UP THE RIDGES DURING THE EVENING HOURS.

TEMPERATURES ACROSS THE RIDGES WILL BE CRITICAL DURING THIS TIME
PERIOD: IF TEMPS DROP LOW ENOUGH...THERE IS THE POTENTIAL TO DROP
A QUICK 1-3 INCHES OF SNOW DURING THIS PERIOD OF TIME.

CURRENT FORECAST ANTICIPATES THAT THIS PRECIP WILL FALL AS RAIN
DURING THE EVENING. AFTER MIDNIGHT...MORE MOISTURE WILL BEGIN TO
MOVE IN FROM THE WEST...ALLOWING FOR SOME SHOWERS TO RETURN TO THE
ENTIRE FORECAST AREA. ALONG THE RIDGES...ABOUT AN INCH OF SNOW IS
EXPECTED AFTER MIDNIGHT. OUTSIDE OF THE RIDGES...A MIX OR
CHANGEOVER TO SNOW CERTAINLY CANNOT BE RULED OUT...BUT
TEMPERATURES ARE EXPECTED TO ONLY DROP TO THE MID 30S
OVERNIGHT...LIMITING ACCUMULATION.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
LOW PRESSURE CENTER SHOULD BE NORTH OF LAKE ONTARIO BY WEDNESDAY
MORNING...AND THE CENTER WILL CONTINUE ITS TREK TO THE NORTHEAST.
WINDS SHOULD BECOME FAVORABLE FOR SOME LAKE EFFECT/UPSLOPE FLOW FOR
SEVERAL HOURS ON WEDNESDAY...AND WITH REMAINS OF DEFORMATION ZONE
MOVING TO THE EAST...HAVE INCREASED POPS ACROSS MOST LOCATIONS
DURING THE DAY. HAVE ALSO BUMPED UP POPS A BIT WEDNESDAY NIGHT FOR
THE RIDGES AS UPSLOPE WINDS SQUEEZE REMAINING MOISTURE OUT. WITH
MUCH COLDER TEMPERATURES WEDNESDAY...REMAINS TO BE SEEN IF SHOWERS
WILL REMAIN SNOW...OR CHANGEOVER TO RAIN. HIGH PRESSURE WILL MOVE
INTO THE REGION BY THURSDAY...ALLOWING FOR DRY CONDITIONS THAT DAY
INTO FRIDAY. ALTHOUGH THERE WILL BE SOME SLIGHT MODERATION IN
TEMPS...HIGHS WILL REMAIN A COUPLE OF DEGREES BELOW NORMAL.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODELS HAVE BEEN CONSISTENT WITH A WEAK COLD FRONT CLIPPING THE
AREA LATE FRIDAY/FRIDAY NIGHT. WITH LIMITED MOISTURE...WILL USE
LOW END CHANCE POPS. DRY AND CHILLY CONDITIONS ARE EXPECTED FOR
SATURDAY...WITH A SMALL CHANCE OF PRECIP COMING IN FOR LATE SUNDAY
AND MONDAY.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
BLEND OF RECENT SURFACE AND RADAR DATA ALONG WITH HRRR AND NAM MODEL
OUTPUT SHOW COLD FRONTAL BAND OF RAIN MOVING NORTHEASTWARD THROUGH
THE UPPER OHIO VALLEY THROUGH EARLY AFTERNOON.

THE MAIN AVIATION CONCERN WILL BE THE WIND. WINDS FROM 2 KFT AGL UP
WILL BE 40 KTS, WITH RAIN NOW OCCURRING, THE FAST WINDS CAN MIX
TO THE SURFACE TO CAUSE GUSTS OF 25-30 KTS, AS EVIDENCED BY RECENT
SURFACE DATA OVER THE MOUNTAINS, FOR EXAMPLE KEKN, K2G4, KJST, AND
KDUJ.

WITHIN THE FRONTAL RAIN BAND, FLIGHT CONDITIONS WILL DETERIORATE TO
MVFR THIS MORNING WITH SHORT-LIVED IFR POSSIBLE IN HEAVIER RAINFALL.

WITH PASSAGE OF THE COLD FRONT TOWARD MIDDAY, SURFACE WINDS WILL
SHIFT INTO THE SOUTHWEST WITH GUSTS TO 20-25 KTS. POST FRONTAL
CONDITIONS THIS AFTERNOON AND TONIGHT WILL BE MAINLY MVFR IN
INTERMITTENT SHOWERS. THERE CAN BE A DRY SLOT WITH VFR CONDITIONS
LATE AFTERNOON INTO EVENING, FOLLOWED BY RENEWED SHOWERS TONIGHT DUE
TO TROWAL DYNAMICS.

SURFACE TEMPERATURES WILL DROP INTO THE 30S, BUT NAM MODEL PROFILES
SUGGEST CLOUDS MAY BE TOO SHALLOW, WEST OF THE MOUNTAINS, TO PRODUCE
A CHANGE TO SNOW SHOWERS AS CLOUD TOP TEMPERATURES CAN BE WARMER
THAN THE M10C NEEDED FOR ICE NUCLEI INITIATION. NEAR THE MOUNTAINS,
CLOUDS CAN BE TALLER AND HENCE HAVE COLDER CLOUD TOPS MAKING SNOW
FORMATION POSSIBLE.

OUTLOOK...WEDNESDAY THROUGH SATURDAY....
CONTINUED POST SYSTEM WRAP-AROUND SHOWERS MAY CAUSE ADDITIONAL
PERIODS OF MAINLY MVFR RESTRICTIONS INTO WEDNESDAY NIGHT.  THEN
MAINLY VFR UNDER HIGH PRESSURE THURSDAY INTO SATURDAY. ALBEIT THERE
IS A SMALL CHANCE OF SHOWERS WITH RESTRICTIONS NORTH FROM A PASSING
GREAT LAKES COLD FRONT FRIDAY NIGHT.

&&

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

&&

$$







AREA FORECAST DISCUSSION

NWS WILMINGTON NC

 615 AM EST TUE NOV 29 2011

.SYNOPSIS...
COOLER AND DRIER AIR WILL BE USHERED IN FROM THE WEST TODAY. HIGH
PRESSURE WILL BUILD ACROSS THE EASTERN CAROLINAS FOR THE REMAINDER
OF THE WEEK. THIS HIGH WILL SHIFT OFF THE NORTHEAST COAST OVER THE
WEEKEND POSSIBLY ALLOWING FOR A SLIGHT MODERATION BACK TOWARDS
SEASONABLE TEMPERATURES.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 330 AM EST TUESDAY...LEADING EDGE OF THE LINE OF CONVECTION
HAS PUSHED ENTIRELY THROUGH THE ILM CWA. ITS POTENTIAL TO PRODUCE
SEVERE WEATHER HAS DIMINISHED CONSIDERABLY. RIGHT NOW...IT CONTINUES
TO PRODUCE DRAMATIC WIND SHIFTS WITH CAA IMMEDIATELY BEHIND IT. POST
FRONTAL RAINS WILL BE THE MAINSTAY THIS MORNING. A NARROW BAND OF
DEEP MOISTURE FROM THE SUBTROPICS/TROPICS WILL KEEP THE POST FRONTAL
RAINS ONGOING INTO DAYLIGHT TUESDAY. UNUSUAL FOR POSTFRONTAL
RAINS...ESPECIALLY WITH PROGGED WIDESPREAD AMOUNTS IN THE ONE
QUARTER TO ONE HALF INCH...ALONG WITH ISOLATED 2+ INCHES. THE HIGHER
AMOUNT HAS ALREADY OCCURRED IN A 15 MILE WIND SWATH BETWEEN
JOHNSONVILLE OF SE FLORENCE COUNTY NORTHWARD ACROSS CENTRAL  MARION
COUNTY TO MINTURN OF WESTERN DILLON COUNTY. PER LATEST HRRR MODEL
RUNS...THE TREND HAS BEEN ENDING THE PCPN BY MID MORNING ILM SC
COUNTIES TO LATE MORNING ACROSS THE ILM NC COUNTIES.

THE UPPER CLOSED LOW WILL BE LIFTING NE ALONG THE BACKBONE OF THE
APPALACHIANS THROUGHOUT THE NEAR TERM...REACHING THE EASTERN GREAT
LAKES WED MORNING. THERE IS ONE MID LEVEL VORTICITY LOBE SPIRALING
AROUND THE UPPER CLOSED LOW...WHICH AFFECTS THE FAR NW PORTIONS OF
THE ILM CWA WITH PVA DURING THIS AFTERNOON. SOME OF THE DEEPER
MOISTURE ROTATING AROUND THE UPPER LOW DOES MOVE ACROSS THE ILM CWA
AT THE SAME TIME THIS VORT DOES. WILL INCLUDE LOW CHANCE FOR POPS TO
ACCOMMODATE. WILL KEEP IT AS LIQUID RAINSHOWERS EVENTHOUGH 850MB
TEMPS ARE PROGGED TO DROP TO -2 ACROSS THIS AREA...HOWEVER THE
1000-850MB THICKNESSES ARE STILL PROGGED ABOVE 1300 THE USUAL
THICKNESS TO SEE FROZEN PCPN. FOR MAX/MIN TEMPS OPTED TO USE THE
LOWER END OF GUIDANCE DUE TO CAA ALREADY OCCURRING. WITH EXCELLENT
LOW LEVEL LAPSE RATES ESPECIALLY DURING THE INSOLATION PART OF THE
DAY...BROKEN TO OVERCAST STRATOCU WILL OVERSPREAD THE ILM CWA.

&&


.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...COOL AND DRY WEATHER IS ON TAP FOR THE DURATION
OF THE SHORT TERM PERIOD. CUTOFF UPPER LOW WILL BE QUICKLY EXITING
TO THE NE ACRS NY AND INTO NEW ENGLAND STATES EARLY WED WITH
LINGERING VORT MAX IN THE TRAILING PART OF THE TROUGH OVER ARKANSAS.
THIS FEATURE WILL CUT TO OUR SOUTH WEDNESDAY EVENING. WITH THE LOW
LEVELS ADVECTING COOL AND DRY AIR HOWEVER THIS UPPER FEATURE WILL
HAVE LITTLE TO NO EFFECT ON SENSIBLE WEATHER. THIS LOW WILL DEEPEN
JUST OFF THE COAST OF THE CAROLINAS EARLY THURSDAY BUT WILL QUICKLY
ACQUIRE A NEGATIVE TILT ALLOWING FOR HEIGHT RISES OVER THE COASTAL
PLAIN TO MOVE IN FROM THE WEST BY THE AFTERNOON. THESE HEIGHT RISES
WILL NOT BE REALIZED AT THE SURFACE...NORMALLY IN THE FORM OF
WARMING TEMPERATURES. WEAK SURFACE HIGH ACROSS THE SOUTHEAST WILL
KEEP MIXING FAIRLY SHALLOW. BOTH DAYS WILL BRING HIGHS IN THE UPPER
50S AND LOWS IN THE LOW TO UPPER 30S...MILDEST ALONG THE COAST BY
NIGHT.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM TUESDAY...LOW AMPLITUDE UPPER RIDGING CROSS THE AREA
FRIDAY AND SATURDAY WHILE SURFACE HIGH PRESSURE REMAINS TO OUR NNE.
THE LATTER WILL TEND TO OFFSET THE WARMING OF THE FORMER TO KEEP
TEMPS BELOW CLIMO. LARGE POSITIVELY TILTED TROUGHINESS DEVELOPS
OVER THE NORTH-CENTRAL PORTION OF THE COUNTRY FOR THE REMAINDER OF
THE PERIOD KEEPING THE AREA DRY. THE HIGH TO OUR NORTH SHOULD
PROGRESS TO THE EAST ENOUGH TO ALLOW FOR A SLIGHT MODERATION OF
TEMPS ESP BY MONDAY.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 12Z...COLD FRONT HAS NOW PAST WELL EAST OF THE CWA...WITH POST
FRONTAL RAIN WITH A MIXTURE OF MVFR AND VFR STRATA CU CEILINGS.
EXPECT VFR TO PREVAIL AT ALL TERMINALS BY MID TO LATE MORNING AS THE
RAIN AND LOWER CEILINGS SLOWLY MOVE EAST. WINDS WILL ACTUALLY BACK
TO THE SOUTHWEST AS THE OCCLUDED SYSTEM SLOWLY PULLS OUT. THE GFS
HAS SOME MVFR STRATA CU LINGERING FOR MOST OF THE DAY...BUT LOW
CONFIDENCE ON THIS...GIVEN THAT MUCH OF THE AREA IS ALREADY 4K FT OR
HIGHER. HAVE BACKED OFF A BIT ON THE GUSTS TODAY...BUT A GUST TO 20
KTS IS NOT OUT OF THE QUESTION. BY LATE AFTERNOON...MOST IF NOT ALL
OF THE DEEP MOISTURE EXITS THE REGION...WITH SCATTERED SKIES
EXPECTED. LOWERING DEWPOINTS AND MODERATE MIXING WILL ALLOW WINDS TO
STAY 10 KTS OR SO THROUGH MUCH OF THE EVENING HOURS.

EXTENDED OUTLOOK...EXPECT VFR THROUGH PERIOD.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM TUESDAY...SFC COLD FRONT HAS PUSHED ACROSS THE LOCAL
WATERS EARLY THIS MORNING. THE ENSUING CAA UNDER SW-W WINDS 15-25 KT
WITH FEW GUSTS 30-35 KT WILL RULE THE DAY. THE SFC PG IS PROGGED TO
RE-TIGHTEN BY MIDDAY ACROSS THE WATERS RESULTING IN SUSTAINED WIND
SPEEDS ON THE HIGHER SIDE OF THE RANGE GIVEN. THE RISEN SEAS WILL
PEAK EARLY THIS MORNING...THEN SLOWLY SUBSIDE TODAY THROUGH TONIGHT.
SOME OF THE HIGHER SEAS...ESPECIALLY THE OUTER WATERS OFF CAPE FEAR
AND ROMAIN...WERE AIDED BY SEAS BLEEDING IN FROM THE OFFSHORE WATERS
WHERE WINDS AT GALE FORCE OCCURRED. THE LOW MID 70S SSTS WERE THE
BIG CONTRIBUTOR FOR THESE HIGHER WINDS MAKING IT TO THE OFFSHORE
OCEAN SFC. SWAN GUIDANCE FOR SEAS WAS USED...BUT DID NOT LOWER THEM
AS FAST AS WHAT SWAN WAS INDICATING. THE SCA MAY NEED TO BE
EXTENDED FURTHER INTO TONIGHT...ESPECIALLY THE WATERS FROM CAPE FEAR
NORTHWARD. AVERAGE PERIODS WILL RUN 6-8 SECONDS THROUGH EARLY THIS
AFTERNOON. THE AVERAGE PERIODS WILL DECREASE TO 4 TO 6 SECONDS LATE
THIS AFTERNOON AND TONIGHT DUE TO WESTERLY WINDS ACROSS A DIMINISHED
FETCH AREA.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...WESTERLY WINDS ON WEDNESDAY WILL BE THE LAST
REMAINING EFFECTS OF THE PREVIOUS STORM SYSTEM...WHICH BY WED WILL
BE RAPIDLY MOVING INTO THE NEW ENGLAND STATES. WIND WILL THEN
TRANSITION OVER TO NORTHERLY LATE WEDNESDAY DUE TO HIGH PRESSURE
BUILDING IN FROM THE WEST. A FAIRLY ROBUST UPPER SYSTEM WILL CROSS
THE WATERS EARLY THURSDAY. POOR DIRECTIONAL ALIGNMENT OF WIND IN THE
VERTICAL HOWEVER WILL PREVENT THIS FROM MAKING MUCH OF A DIRECT
EFFECT/INCREASE IN SURFACE WIND SPEEDS. NO HEADLINES EXPECTED THIS
PERIOD FOR THE MOST PART. THE EXCEPTION MAY BE TOWARDS THE END OF
THE PERIOD WHEN SOME 5 FT SEAS MANAGE TO AFFECT THE VERY OUTER
REACHES OF THE 20NM FCST ZONE.

LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 AM TUESDAY...N TO NE FLOW ON THE SOUTHEAST PERIPHERY OF HIGH
PRESSURE WILL CHARACTERIZE MOST OF THE PERIOD. WHILE WIND SPEED MAY
SHOW LITTLE VARIATION THOUGH THE PERIOD THE INCREASING TIME OF THE
STEADY FETCH COULD ADD SLIGHTLY TO WAVE HEIGHTS. 5 FT SEAS MAY
OCCASIONALLY BE AFFECTING THE OUTER PORTIONS OF MAINLY THE NORTHERN
ZONES. IT IS THUS HARD TO ASCERTAIN THE NEED FOR ANY CAUTIONARY
HEADLINES THIS FAR OUT IN TIME.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST TUESDAY FOR AMZ250-252-
     254-256.

&&

$$

SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43














AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 930 AM EST TUE NOV 29 2011

.SYNOPSIS...
LOW PRESSURE WILL MOVE ACROSS TODAY. SOME LIGHT PRECIPITATION THROUGH
TONIGHT. HIGH PRESSURE THURSDAY. MOISTURE STARVED FRONT FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
915 AM UPDATE. NEW COMMA SHAPED AREA OF RAIN HAS QUICKLY DEVELOPED
OVER SOUTHERN THIRD OF CWA IN RESPONSE TO YET ANOTHER IMPULSE
ROTATING AROUND APPROACHING UPPER LOW OVER THE TENNESSEE VALLEY.
THIS WILL SHIFT NORTH THIS MORNING AND MAINLY BE NORTH OF OUR CWA BY
EARLY AFTERNOON. HAVE UPPED POPS WITH THIS FEATURE THRU EARLY
AFTERNOON. THEN...PER CURRENT FORECAST...SHOWERS DEVELOP LATER THIS
AFTERNOON UNDER THE UPPER LOW. ALSO TWEAKED TEMPS DOWNWARD PER
CURRENT TEMPS AND TRENDS UPSTREAM.

PREVIOUS DISCUSSION BELOW...
FRONT AS 0830Z HAD JUST PASSED UNI-3I2-CRW-BKW LINE...WITH BRIEF GUSTS
NEAR 25KTS ON NARROW ELEVATED CONVECTIVE BAND. HAVE OCCLUDED FRONT
CLEARING CENTRAL LOWLANDS NEXT HR AND SE OH/NORTHERN WV LOWLANDS BY
12Z. BOUNDARY TAKES ON MORE OF A NW TO SE ORIENTATION IN THE
MTNS...HENCE A FEW HRS DELAY OF FROPA FROM TO S TO N. DRY SLOT
QUICKLY WORKS IN THRU MID MORNING...EFFECTIVELY SHUTTING OFF PCPN
AFTER A COUPLE HRS POST FRONTAL RAINS. THIS MAY LINGER LONGER ACROSS
SE OH AND THE NORTHERN AREAS DUE TO LAGGING NATURE OF BOUNDARY
ACROSS MTNS AND INTO VA. RAINFALL AMOUNTS TO HALF AN INCH LOOK GOOD
WITH THIS...WITH UP TO AN INCH ALONG EAST FACING SLOPES IN MTNS.

REWORKED HRLY TEMPERATURE GRIDS TDY FROM LAV AND RUC TO REFLECT MILD
READINGS AHEAD OF BOUNDARY EARLY THIS MORNING AND DROPPING TMPS WITH FROPA.
LOOKING AT A MIDNIGHT HIGH FOR ALL PLACES...WITH TEMPS DROPPING
10-15 DEGREES WITH FROPA...AND SLOWLY FALLING THROUGH 40S TDY...WITH
30S ACROSS THE HIGH TERRAIN.

DEEP UPR LOW WILL TRACK THRU EASTERN KY THIS AFTN AND INTO THE AREA
THIS EVENING. THIS WILL INCREASE THE MOISTURE DEPTH AND LIFT TO
ALLOW LIGHT PCPN TO BREAK OUT LATE THIS AFTN ACROSS SE KY AND INTO
SOUTHERN AREAS THIS EVENING BEFORE ROTATING UP THE SPINE OF MTNS
TONIGHT. DRY SLOT MAY PIVOT ARND INTO SE OH...KEEPING AREAS ALONG
AND WEST OF OH RVR DRY INTO THE EARLY PART OF THE NIGHT...BEFORE
FILLING IN TOWARD MORNING.

AREA WILL SEE THE BEST UPR LOW HAS TO OFFER WITH RESPECT TO
MAGNITUDE OF COLD POOL ALOFT. H85 TMPS BOTTOM OUT TO ARN -5C BY 12Z
WED. A MONTH FROM NOW...THERE WOULD BE NO CONCERN ABOUT PCPN TYPE
OUTSIDE OF MTNS. HOWEVER...AS IT STANDS....BL WILL BE SLOW TO COOL
THIS EVENING. MDLS SHOW BL TEMPS AND H925 TMPS WARM ENOUGH TO KEEP
THINGS LIQUID OUTSIDE OF THE MTNS UNTIL AFTER MIDNIGHT...IF NOT A
LITTLE LONGER. EVEN IN MTNS...WHERE IT SHOULD BE COLD ENOUGH FOR
SNOW...KEEP ACCUMULATIONS TO ARND AN INCH OR SO IN THE AOA
3KFT...DUE TO VERY WET AND WARM GRND. WITH SATURATION/WEAK LIFT TO NEAR
-8C...WILL KEEP DZ MENTION OUT OF GRIDS ATTM.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
MODELS SHOW SOME LINGERING MOISTURE ON WEDNESDAY. 850 MB
TEMPERATURES ARE NOT COLD ENOUGH FOR AUTO CONVECTION IN THE LOWER
LAYER...SO WILL KEEP POPS ON THE LOW SIDE. BASED ON 850 MB
TEMPERATURES AND WITH SOME CLEARING IN THE WESTERN COUNTIES DURING
THE DAY WEDNESDAY...MOS GUIDANCE IN THE WEST LOOKS A BIT TOO COLD.
HIGH PRESSURE THEN BUILDS IN FOR THURSDAY. A MOISTURE STARVED FRONT
ARRIVES ON FRIDAY...BUT BASED ON LACK OF MOISTURE IN THE
MODELS...WILL KEEP A DRY FORECAST FOR NOW.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
HAVE GONE WITH HPC THINKING FOR THIS PART OF THE FORECAST...WHICH
LEANS TOWARDS THE ECMWF/UKMET/CANADIAN SOLUTIONS. LATEST 12 UTC
GFS MODEL HAS TRENDED TOWARDS THESE SOLUTIONS AS WELL.

A WEAK COLD FRONT WILL PUSH THROUGH THE AREA ON FRIDAY.  HOWEVER...
THE AIRMASS WILL BE QUITE DRY...SO NO PRECIP IS EXPECTED WITH THIS
FEATURE.  HIGH PRESSURE WILL THEN BE IN CONTROL FOR SATURDAY AND
SATURDAY NIGHT...BEFORE A COLD FRONT APPROACHES FROM THE WEST
SUNDAY.  THE FRONT IS EXPECTED TO BE IN THE AREA ON MONDAY.

AS A RESULT...EXPECT PRECIP CHANCES WILL INCREASE BY LATE
SUNDAY...WITH CHANCES CONTINUING THROUGH THE END OF THE PERIOD.

ONLY REAL CHANGES FROM HPC THINKING WERE THE SKY GRIDS.  FELT HPC
FORECAST INCLUDED TOO MANY CLOUDS WITH DRY FRONT ON FRIDAY...SO
TWEAKED DOWNWARD.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
15Z TUESDAY THRU 12Z WEDNESDAY...
UPDATED TO INCREASE SHOWERS CENTRAL AND NORTH THRU EARLY AFTERNOON
WITH IMPULSE ROTATING NORTH NORTHWEST AROUND APPROACHING UPPER LOW
OVER THE TENNESSEE VALLEY. EXPECT MVFR TO IFR IN THIS AREA OF RAIN
SHOWERS.

PREVIOUS DISCUSSION...
BEHIND THE FRONT...GENERALLY MVFR CEILINGS PREVAIL WITH A COUPLE HRS
OF POST FRONTAL RAINS AS WINDS TURNING TO SOUTH SOUTHWEST. DRY SLOT
WORKS IN THRU MID MORNING...ESSENTIALLY ENDING PCPN FOLLOWING POST
FRONTAL RAINS. NOT COLD ENOUGH YET FOR SNOW EXCEPT POSSIBLY IN
SOUTHERN MOUNTAIN RIDGETOPS AFTER 16Z WITH NO ACCUMULATION.

UPR LOW ROTATES THRU THIS AFTN. MOISTURE DEPTH INCREASE UNDER COLD
POOL WHICH SHOULD ALLOW SHOWERY PCPN TO BREAK OUT ACROSS THE AREA
THIS EVENING. AS LLVL TEMPS CONT TO COOL...A TRANSITION TO SHSN IS
EXPECTED ACROSS THE MTNS. BRING BACK MVFR CIGS THIS AFTN UNDER
COLD POOL...WITH IFR CONDITIONS MTNS AMID DEVELOPING SHSN.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...

FORECAST CONFIDENCE: HIGH TO MEDIUM.

ALTERNATE SCENARIOS: TIMING OF OCCLUDED FRONT AND LOWER CEILINGS
WITH BAND OF RAIN SHOWERS MAY VARY. DOWNSLOPING EFFECTS MAY KEEP
KCKB AND KEKN VFR AHEAD OF FRONT. VARYING CIGS POST FRONTAL.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

UTC 1HRLY       14   15   16   17   18   19   20   21   22   23   00   01
EST 1HRLY       09   10   11   12   13   14   15   16   17   18   19   20
CRW CONSISTENCY  M    H    H    H    L    H    H    M    H    H    H    M
HTS CONSISTENCY  M    M    H    H    H    H    H    H    H    H    M    M
BKW CONSISTENCY  M    M    M    L    H    H    H    H    M    M    M    M
EKN CONSISTENCY  M    H    H    H    H    M    L    L    H    H    M    M
PKB CONSISTENCY  H    M    M    L    M    H    M    M    H    H    H    H
CKB CONSISTENCY  M    H    H    M    M    L    L    M    H    H    H    H

AFTER 12Z WEDNESDAY...
IFR POSSIBLE IN RAIN AND SNOW LATE TUE INTO WED...MAINLY MOUNTAINS.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...JSH/RPY/30
NEAR TERM...JMV
SHORT TERM...RPY
LONG TERM...JSH
AVIATION...JMV











AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 609 AM EST TUE NOV 29 2011

.SYNOPSIS...
LOW PRESSURE WILL MOVE ACROSS TODAY. SOME LIGHT PRECIPITATION
TONIGHT. HIGH PRESSURE THURSDAY. MOISTURE STARVED FRONT FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATED...
FCST ON TRACK...NO CHANGES ATTM.

PREVIOUS DISCUSSION BELOW...
FRONT AS 0830Z HAD JUST PASSED UNI-3I2-CRW-BKW LINE...WITH BRIEF GUSTS
NEAR 25KTS ON NARROW ELEVATED CONVECTIVE BAND. HAVE OCCLUDED FRONT
CLEARING CENTRAL LOWLANDS NEXT HR AND SE OH/NORTHERN WV LOWLANDS BY
12Z. BOUNDARY TAKES ON MORE OF A NW TO SE ORIENTATION IN THE
MTNS...HENCE A FEW HRS DELAY OF FROPA FROM TO S TO N. DRY SLOT
QUICKLY WORKS IN THRU MID MORNING...EFFECTIVELY SHUTTING OFF PCPN
AFTER A COUPLE HRS POST FRONTAL RAINS. THIS MAY LINGER LONGER ACROSS
SE OH AND THE NORTHERN AREAS DUE TO LAGGING NATURE OF BOUNDARY
ACROSS MTNS AND INTO VA. RAINFALL AMOUNTS TO HALF AN INCH LOOK GOOD
WITH THIS...WITH UP TO AN INCH ALONG EAST FACING SLOPES IN MTNS.

REWORKED HRLY TEMPERATURE GRIDS TDY FROM LAV AND RUC TO REFLECT MILD
READINGS AHEAD OF BOUNDARY EARLY THIS MORNING AND DROPPING TMPS WITH FROPA.
LOOKING AT A MIDNIGHT HIGH FOR ALL PLACES...WITH TEMPS DROPPING
10-15 DEGREES WITH FROPA...AND SLOWLY FALLING THROUGH 40S TDY...WITH
30S ACROSS THE HIGH TERRAIN.

DEEP UPR LOW WILL TRACK THRU EASTERN KY THIS AFTN AND INTO THE AREA
THIS EVENING. THIS WILL INCREASE THE MOISTURE DEPTH AND LIFT TO
ALLOW LIGHT PCPN TO BREAK OUT LATE THIS AFTN ACROSS SE KY AND INTO
SOUTHERN AREAS THIS EVENING BEFORE ROTATING UP THE SPINE OF MTNS
TONIGHT. DRY SLOT MAY PIVOT ARND INTO SE OH...KEEPING AREAS ALONG
AND WEST OF OH RVR DRY INTO THE EARLY PART OF THE NIGHT...BEFORE
FILLING IN TOWARD MORNING.

AREA WILL SEE THE BEST UPR LOW HAS TO OFFER WITH RESPECT TO
MAGNITUDE OF COLD POOL ALOFT. H85 TMPS BOTTOM OUT TO ARN -5C BY 12Z
WED. A MONTH FROM NOW...THERE WOULD BE NO CONCERN ABOUT PCPN TYPE
OUTSIDE OF MTNS. HOWEVER...AS IT STANDS....BL WILL BE SLOW TO COOL
THIS EVENING. MDLS SHOW BL TEMPS AND H925 TMPS WARM ENOUGH TO KEEP
THINGS LIQUID OUTSIDE OF THE MTNS UNTIL AFTER MIDNIGHT...IF NOT A
LITTLE LONGER. EVEN IN MTNS...WHERE IT SHOULD BE COLD ENOUGH FOR
SNOW...KEEP ACCUMULATIONS TO ARND AN INCH OR SO IN THE AOA
3KFT...DUE TO VERY WET AND WARM GRND. WITH SATURATION/WEAK LIFT TO NEAR
-8C...WILL KEEP DZ MENTION OUT OF GRIDS ATTM.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
MODELS SHOW SOME LINGERING MOISTURE ON WEDNESDAY. 850 MB
TEMPERATURES ARE NOT COLD ENOUGH FOR AUTO CONVECTION IN THE LOWER
LAYER...SO WILL KEEP POPS ON THE LOW SIDE. BASED ON 850 MB
TEMPERATURES AND WITH SOME CLEARING IN THE WESTERN COUNTIES DURING
THE DAY WEDNESDAY...MOS GUIDANCE IN THE WEST LOOKS A BIT TOO COLD.
HIGH PRESSURE THEN BUILDS IN FOR THURSDAY. A MOISTURE STARVED FRONT
ARRIVES ON FRIDAY...BUT BASED ON LACK OF MOISTURE IN THE
MODELS...WILL KEEP A DRY FORECAST FOR NOW.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
HAVE GONE WITH HPC THINKING FOR THIS PART OF THE FORECAST...WHICH
LEANS TOWARDS THE ECMWF/UKMET/CANADIAN SOLUTIONS. LATEST 12 UTC
GFS MODEL HAS TRENDED TOWARDS THESE SOLUTIONS AS WELL.

A WEAK COLD FRONT WILL PUSH THROUGH THE AREA ON FRIDAY.  HOWEVER...
THE AIRMASS WILL BE QUITE DRY...SO NO PRECIP IS EXPECTED WITH THIS
FEATURE.  HIGH PRESSURE WILL THEN BE IN CONTROL FOR SATURDAY AND
SATURDAY NIGHT...BEFORE A COLD FRONT APPROACHES FROM THE WEST
SUNDAY.  THE FRONT IS EXPECTED TO BE IN THE AREA ON MONDAY.

AS A RESULT...EXPECT PRECIP CHANCES WILL INCREASE BY LATE
SUNDAY...WITH CHANCES CONTINUING THROUGH THE END OF THE PERIOD.

ONLY REAL CHANGES FROM HPC THINKING WERE THE SKY GRIDS.  FELT HPC
FORECAST INCLUDED TOO MANY CLOUDS WITH DRY FRONT ON FRIDAY...SO
TWEAKED DOWNWARD.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
LOW PRESSURE LIFTS NORTH OUT OF AREA TDY.

OCCLUDED FRONT WORKING ACROSS THE AREA THRU 13Z. ELEVATED
CONVECTIVE BAND MAY PRODUCE BRIEF IFR CIGS/VSBY. HAVE CODED UP
SOME TEMPO GROUPS TO HANDLE THIS IT MOVES ACROSS NORTHERN SITES
12-14Z. DOWNSLOPING EFFECTS COULD MITIGATE THIS FOR KEKN AND KCKB.

BEHIND THE FRONT...GENERALLY MVFR CEILINGS PREVAIL WITH A COUPLE
HRS OF POST FRONTAL RAINS AS WINDS TURNING TO SOUTH SOUTHWEST. DRY
SLOT WORKS IN THRU MID MORNING...ESSENTIALLY ENDING PCPN FOLLOWING
POST FRONTAL RAINS. NOT COLD ENOUGH YET FOR SNOW EXCEPT POSSIBLY
IN SOUTHERN MOUNTAIN RIDGETOPS AFTER 16Z WITH NO ACCUMULATION.

UPR LOW ROTATES THRU THIS AFTN. MOISTURE DEPTH INCREASE UNDER COLD
POOL WHICH SHOULD ALLOW SHOWERY PCPN TO BREAK OUT ACROSS THE AREA
THIS EVENING. AS LLVL TEMPS CONT TO COOL...A TRANSITION TO SHSN IS
EXPECTED ACROSS THE MTNS. BRING BACK MVFR CIGS THIS AFTN UNDER
COLD POOL...WITH IFR CONDITIONS MTNS AMID DEVELOPING SHSN.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...

FORECAST CONFIDENCE: HIGH TO MEDIUM.

ALTERNATE SCENARIOS: TIMING OF OCCLUDED FRONT AND LOWER CEILINGS
WITH BAND OF RAIN SHOWERS MAY VARY. DOWNSLOPING EFFECTS MAY KEEP
KCKB AND KEKN VFR AHEAD OF FRONT. VARYING CIGS POST FRONTAL.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

UTC 1HRLY       11   12   13   14   15   16   17   18   19   20   21   22
EST 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
CRW CONSISTENCY  M    M    H    H    M    H    H    H    H    H    H    H
HTS CONSISTENCY  M    H    M    M    M    M    H    M    H    M    M    M
BKW CONSISTENCY  H    H    H    H    H    H    M    L    H    M    M    H
EKN CONSISTENCY  M    M    M    M    H    H    L    M    H    H    H    H
PKB CONSISTENCY  M    L    M    L    H    M    L    H    H    H    H    H
CKB CONSISTENCY  M    L    M    M    M    M    M    L    H    H    H    H

AFTER 12Z WEDNESDAY...
IFR POSSIBLE IN RAIN AND SNOW LATE TUE INTO WED...MAINLY MOUNTAINS.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...JSH/RPY/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...JSH
AVIATION...30









AREA FORECAST DISCUSSION...UPDATED

NWS BROWNSVILLE TX

 539 AM CST TUE NOV 29 2011

.DISCUSSION...SEE THE AVIATION SEGMENT BELOW FOR A DISCUSSION OF
THE 12Z TAF PACKAGE. ALSO...SEE THE MARINE SEGMENT BELOW FOR A
MINOR ADJUSTMENT TO THE FIRST PERIOD OF THE COASTAL WATERS
FORECAST.
&&

.AVIATION...NO CHANGES WERE NEEDED TO THE EXISTING TAFS. VFR
CONDITIONS WILL CONTINUE TO PREVAIL THROUGH THE NEXT 24 HOURS.
THE PASSAGE OF SURFACE HIGH PRESSURE LOCATED SOUTH OF THE RIO
GRANDE VALLEY TO THE EAST...AS WELL AS THE PASSAGE OF A WEAK COLD
FRONT THROUGH OUR REGION LATER TODAY AND TONIGHT...WILL PRODUCE
MAINLY LIGHT AND VARIABLE WINDS THROUGH THE PERIOD.
&&

.MARINE...BUOY 42020 REPORTED SOUTHWEST WINDS AROUND 19 KNOTS WITH
GUSTS TO AROUND 23 KNOTS WITH SEAS SLIGHTLY OVER 4.5 FEET WITH A
PERIOD OF 5 SECONDS AT 05 CST/11 UTC. STRONGER WINDS AND HIGHER
SEAS ARE OCCURRING ALONG THE LOWER TEXAS COAST...A TREND TOTALLY
MISSED BY THE GFS MODEL AND CONFIRMED BY THE RUC. THUS...HAVE
RAISED SMALL CRAFT EXERCISE CAUTION AND INDICATED WINDS OF 15 TO
20 KNOTS FOR THE GULF OF MEXICO WATERS EAST OF PADRE ISLAND FROM
0 TO 60 NAUTICAL MILES OFFSHORE UNTIL NOON TODAY BASED ON THE BUOY
OB AND RUC DATA. RUC SUGGESTS THAT MARINE CONDITIONS WILL IMPROVE
BY THE MID-MORNING TODAY...AT WHICH TIME THE INCOMING SHIFT COULD
LIKELY DISCONTINUE THE SCEC. NO OTHER MARINE FORECAST CHANGES
MADE.
&&

.PREV DISCUSSION... /ISSUED 422 AM CST TUE NOV 29 2011/

SHORT TERM /TODAY THROUGH WEDNESDAY/...PLEASANT WEATHER CONDITIONS
WILL DOMINATE THE FIRST 36 HOURS OF THE FORECAST. DRY WEATHER WILL
PREVAIL TODAY AS A MID-LEVEL NORTHWEST-TO-SOUTHEAST FLOW DOMINATES
OVERHEAD...WHILE WARMER TEMPERATURES DEVELOP COURTESY OF A FLOW FROM
THE SOUTH AND SOUTHWEST AT THE SURFACE. ALTHOUGH A WEAK COLD FRONT
WILL PUSH THROUGH DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY LATER
TODAY AND TONIGHT...COURTESY OF SURFACE HIGH PRESSURE BUILDING SOUTH
AND EAST THROUGH THE LONE STAR STATE...NO RAINFALL IS EXPECTED DUE
TO DRY ATMOSPHERIC CONDITIONS CAUSED BY PRECIPITABLE WATER AMOUNTS
UNABLE TO RECOVER FROM THE RECENT STRONG COLD FRONT. COOL AND DRY
WEATHER IS EXPECTED TONIGHT...WITH DRY WEATHER CONTINUING TOMORROW
ALONG WITH NEAR NORMAL TEMPERATURES...COURTESY OF THE COLD FRONTAL
PASSAGE LATER TODAY AND TONIGHT.

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...THE LONGER RANGE
MODEL GUIDANCE CONTINUES TO ADVERTISE A STRONG MID LEVEL SHORT
WAVE DIVING SOUTH ACROSS THE WEST COAST WED AND THURS. THIS SHORT
WAVE CUTS OFF AND SLOWS DOWN CONSIDERABLY OVER THE DESERT SW LATE
THURS AND FRI. THIS FEATURE THEN OPENS UP AS A MORE PROGRESSIVE
SHORT WAVE FRI NIGHT INTO SAT MOVING INTO THE CENTRAL MISS RIVER
VALLEY SUN. FAIRLY DEEP MOISTURE VALUES POOL AHEAD OF THIS FEATURE
OVER THE SW STATES AND THE NORTHERN HALF OF TX. MEANWHILE DEEP
SOUTH TX WILL REMAIN ON THE SOUTHERN FRINGES OF THIS DEEPER
MOISTURE FIELD AND THE STRONGER MID LEVEL DYNAMICS ASSOCIATED WITH
THE CLOSED LOW/TROUGH. WILL MAINTAIN THE MENTION OF 20 TO 30 %
POPS WITH THE APPROACH AND PASSAGE OF THE COLD FRONT ASSOCIATED
WITH THIS MID LEVEL FEATURE PROVIDING THE BEST SURFACE
CONVERGENCE.

THE GFS AND THE ECMWF CONTINUE TO HAVE SOME TIMING DIFFERENCES
WITH THE HANDLING OF THIS FEATURE. THE GFS HAS A LITTLE FASTER
MOVEMENT OF MID LEVEL TROUGH/CLOSED LOW VERSUS THE ECWMF. THESE
TIMING DIFFERENCES EXTEND ON DOWN TO THE SURFACE WITH THE COLD
FRONT ASSOCIATED WITH THIS SYSTEM MOVING THROUGH FASTER IN THE GFS
SOLUTION VERSUS THE SLOWER ECMWF. THE RUN TO RUN CONSISTENCY WITH
THE GFS MEX MOS IS ABOVE AVERAGE AND WILL GO WITH THE GFS SOLUTION
WHICH IS A LITTLE MORE REALISTIC VERSUS THE ECMWF OUTPUT.

MARINE...TODAY THROUGH WEDNESDAY...A WEAK COLD FRONT WILL PASS
THROUGH THE LOWER TEXAS COAST LATER TODAY AND TONIGHT...BUT NO MAJOR
CHANGES IN WINDS AND SEAS ARE EXPECTED IN THE WAKE OF THE FRONT.
OVERALL...LIGHT TO MODERATE WINDS AND LOW TO MODERATE SEAS WILL
PREVAIL FOR THE ADJACENT COASTAL WATERS OF DEEP SOUTH TEXAS TODAY
THROUGH WEDNESDAY.

WEDNESDAY NIGHT THROUGH SATURDAY...THE FORMATION OF THE CLOSED
MID LEVEL LOW TO THE WEST OF TX WILL RESULT IN A MODERATE TO
STRONG PGF ALONG THE LOWER TX COASTLINE. AS A RESULT EXPECT THE SE
SURFACE FLOW TO INCREASE PUSHING ON UP INTO SCEC/SCA CRIT AFTER
WED.
&&

.BRO WATCHES/WARNINGS/ADVISORIES...NONE.
&&

$$

THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE






AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

 313 PM CST TUE NOV 29 2011

.DISCUSSION...
313 PM CST

MESOSCALE/TONIGHT...

A VERY IMPRESSIVE WATER VAPOR SATELLITE LOOP THIS AFTERNOON
REVEALS THE EXPANSIVE COLD CORE LOW LIFTING NORTHEAST ACROSS THE
APPALACHIANS...JUST GRAZING THE AREA. A WELL-DEFINED DEFORMATION
AREA HAS FILLED IN WITH BANDS OF COLDER AND AT TIMES CONVECTIVE
CLOUD TOPS PROVIDING HEAVIER AND FROZEN PRECIPITATION ACROSS PARTS
OF NORTHERN IN. THE DUAL POLARIZATION RADAR EVEN DETECTED THE
PRECIPITATION TYPE SWITCH AT 7000-9000 FT. THIS HAS BEEN OBSERVED
AT THE GROUND JUST TO THE SOUTH AND EAST OF THE FORECAST AREA IN
LAFAYETTE /WHERE SLUSHY ACCUMULATION HAS OCCURRED ON GRASSY
SURFACES/. THE 13KM RUC SOUNDINGS ACROSS BENTON AND JASPER
COUNTIES CONTINUE TO SHOW A GRADUAL SHRINKING OF THE NEAR-SURFACE
WARM LAYER TO ALLOW FOR A MIX TO MAKE IT TO THE GROUND FOR
POSSIBLY A COUPLE HOURS. THAT COUPLE OF HOURS LOOKS TO BE IT GIVEN
SATELLITE AND SHORT TERM MODEL TRENDS TO SHIFT THE FORCING EAST.
GIVEN THAT ANY TRANSITION WILL BE SO SHORT LIVED AND OVER WARM
GROUND...WILL CANCEL THE WINTER WEATHER ADVISORY.

STRONG NORTHERLY WINDS HAVING GUSTED AS HIGH AS 60 MPH AT THE
CHICAGO CRIB...52 MPH AT GARY...AND 48 MPH AT MIDWAY WILL
GRADUALLY DIMINISH THROUGH THE EVENING WITH THE AREA PINCHED
BETWEEN THE 1001 MB LOW NEAR CLEVELAND AND THE INCOMING 1027 MB
RIDGE. AN AIRCRAFT SOUNDING OUT OF OHARE JUST AFTER 2 PM REVEALED
40 KT WINDS AT THE TOP OF THE CHANNEL...AND NAM AND RUC SOUNDINGS
KEEP SIMILAR SPEEDS WITHIN THE BOUNDARY LAYER UNTIL A COUPLE HOURS
AFTER SUNSET. WITH STILL AN ONSHORE COMPONENT TO THE WIND...WILL
LET THE WIND ADVISORY CONTINUE. A QUICK DECOUPLING LATER IN THE
EVENING SHOULD ALLOW FOR WINDS TO COME DOWN MORE RAPIDLY ACROSS
THE ILLINOIS FORECAST AREA. ASSOCIATED LAKE SHORE FLOODING
CONCERNS WITH THE WIND ALSO CONTINUE GIVEN THE 10 TO 15 FT WAVES
FORECAST...BUT LIKELY WILL NOT LAST AS FAR INTO WEDNESDAY. CLOUDS
SHOULD SCOUR FAIRLY QUICKLY WEST OF CHICAGO THROUGH EARLY
EVENING...THEN MORE SLOWLY DOWNSTREAM OF THE LAKE. WHILE SOME LAKE
ENHANCED CLOUDS MAY OCCUR...FORECAST DEPTHS ARE VERY SHALLOW WITH
DRIER AIR BEING RAKED IN ON THE NORTHERLY WINDS...AND THUS NOT
EXPECTING ANY SHOWERS. WITH FORECAST TEMPERATURES HAVE MADE ONLY
MINOR TWEAKS...WITH READINGS ALMOST RIGHT AT NORMAL ACROSS THE
ENTIRE FORECAST AREA.

MTF

WEDNESDAY THROUGH TUESDAY...

ACTUALLY LOOKING LIKE A DAY OR TWO OF FAIRLY PLEASANT LATE NOVEMBER
WEATHER WEDNESDAY INTO THURSDAY IN WAKE OF TODAY`S SIDESWIPING BY
THE STRONG STORM SYSTEM. WARM AIR ADVECTION WILL COMMENCE WEDNESDAY
AS LOW/MID LEVEL FLOW BEGINS TO BACK IN ADVANCE OF THE NEXT NORTHERN
STREAM SHORTWAVE WHICH WILL BEGIN DROPPING INTO THE NORTHERN PLAINS.
AFTER A CHILLY MORNING TEMPS SHOULD REBOUND NICELY TOMORROW WITH
NEARLY FULL SUNSHINE.

INCREASING MID/HIGH LEVEL CLOUDINESS AND SOUTHWEST WINDS SHOULD KEEP
TEMPS A BIT WARMER TOMORROW NIGHT WHICH WILL THEN PROVIDE FOR A NICE
SPRING BOARD FOR TEMPS THURSDAY TO CLIMB BACK TO SEVERAL DEGREES
ABOVE AVERAGE. COLD FRONT WILL THEN DROP SOUTHWARD ACROSS THE CWA
LATE THURSDAY AFTERNOON/EARLY THURSDAY EVENING. STRONGEST FORCING
WITH THIS WAVE LOOKS TO PASS WELL NORTH/NORTHEAST OF THE AREA AND
WITH SCANT MOISTURE AT BEST AM HAVING A HARD TIME GETTING TOO WORKED
UP OVER OUR SNOW CHANCES THURSDAY NIGHT. ECMWF/GFS BOTH STILL TRYING
TO SPIT OUT A HUNDREDTH OF AN INCH OR SO OF QPF SO HAVE MAINTAINED
THE SLIGHT CHANCE POPS WE HAD GOING...WHICH ARE SUPPORTED BY CURRENT
MOS NUMBERS.

VERY QUICK HITTING SHOT OF FAIRLY COLD AIR THEN ARRIVES LATER
THURSDAY NIGHT AND ESPECIALLY FRIDAY. THERE STILL DOES APPEAR TO BE
A SMALL WINDOW OF OPPORTUNITY FOR SOME LAKE EFFECT SNOW SHOWERS IN
PORTER COUNTY LATE THURSDAY NIGHT INTO FRIDAY MORNING...BUT NOT
EXPECTING ANYTHING SIGNIFICANT WITH LAKE EFFECT PARAMETERS FAIRLY
MARGINAL AND DURATION BEING SHORT AS FLOW QUICKLY BACKS TO
SOUTHERLY FRIDAY AFTERNOON.

BY THIS WEEKEND OUR ATTENTION WILL TURN THE THE VIGOROUS UPPER LOW
THATS CURRENTLY OFF THE BRITISH COLUMBIA COAST. MEDIUM RANGE
GUIDANCE IS IN REMARKABLY GOOD AGREEMENT THROUGH FRIDAY WITH THIS
SYSTEM DROPPING SOUTH AND WITH AN ANOMALOUSLY STRONG UPPER LOW (H5
HEIGHTS 3+ STANDARD DEVIATIONS BELOW AVERAGE) SETTING UP SHOP OVER
THE DESSERT SOUTHWEST BY FRIDAY. MODERATE RIDGING DOWNSTREAM OVER
THE SOUTHEASTERN CONUS SHOULD LEAVE OUR AREA IN A WEST-SOUTHWEST
FLOW ALOFT.

FORECAST CONFIDENCE THIS WEEKEND INTO EARLY NEXT WEEK IS LOW AS
MODELS OFTEN STRUGGLE WITH CUT OFF LOWS. HAVING SAID THAT...IT
APPEARS AS THOUGH THIS FIRST UPPER LOW WILL WEAKEN INTO AN OPEN WAVE
AND RIDE THE SOUTHWEST FLOW ALOFT INTO OUR AREA THIS WEEKEND...WITH
SOME DEGREE OF PHASING WITH A RESULTANT AMPLIFYING NORTHERN
STREAM TROUGH EXPECTED. WHILE DETAILS ARE MURKY...IT WOULD APPEAR
THAT OUR AREA IS IN STORE FOR INCREASINGLY UNSETTLED WEATHER LATE
SATURDAY INTO SUNDAY. WITH VARYING SOLUTIONS ABOUT THE TRACK OF
THE SURFACE SYSTEM AND RESULTANT THERMAL PROFILES IT WOULD BE
ABSURD TRYING TO PINPOINT P-TYPES FOR THE WEEKEND JUST YET.
ANOTHER...POTENTIALLY MORE SIGNIFICANT BUT BRIEF BLAST OF COLD AIR
LOOKS TO ARRIVE IN THE WAKE OF THIS SYSTEM EARLY NEXT WEEK.

IZZI

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 20Z...

* STRONG NORTH TO NORTHEAST WINDS WITH GUSTS TO 35 KT THROUGH
  LATE THIS AFTERNOON.
* WINDS NOW BEGINNING A SLOW WEAKENING TREND.
* OCNL MVFR CIGS PERSISTING THROUGH SUNSET.

KREIN

//DISCUSSION...UPDATED 18Z...

WINDS WILL REMAIN THE MAIN AVIATION CONCERN THROUGH THIS EVENING.

THE STRONG LOW PRESSURE SYSTEM HAS MOVED INTO NORTHEASTERN OHIO.
COMBINED WITH HIGH PRESSURE EXTENDING FROM THE CENTRAL PLAINS
THROUGH THE WESTERN GREAT LAKE...THE SURFACE PRESSURE GRADIENT HAS
REACHED IT`S STRONGEST AND EXPECT A FAIRLY STEADY STATE TO WIND
SPEEDS FOR THE NEXT 4-5HRS. THE LATEST AIRCRAFT WIND REPORTS
INDICATE WIND SPEEDS AROUND 50KT AT THE TOP OF THE MIXED LAYER OF
ABOUT 4KFT AGL. HOWEVER...WITH OVC MVFR CIGS...THE STRONGEST WINDS
HAVE NOT BEEN ABLE TO MIX DOWN TO THE SURFACE...THOUGH 40+ KT GUSTS
HAVE BEEN OBSERVED AT ORD/MDW/GYY. THERE IS STILL THE POTENTIAL
FOR AN ISOLD 45-50KT GUST AT ORD/MDW THROUGH ABOUT
21Z...ESPECIALLY IF SOME BREAKS IN THE OVERCAST CAN DEVELOP.

THE LOW CENTER WILL STEADILY TRACK TO THE NORTHEAST THROUGH THE
AFTERNOON AND EVENING. WINDS WILL REMAIN STRONG AND GUSTY THROUGH
THE EVENING...AND EXPECT THAT GUSTS IN EXCESS OF 30KT WILL
CONTINUE THROUGH THE EARLY EVENING AND THEN GRADUALLY DIMINISH
THROUGH THE NIGHT.

AS THE SFC HIGH GRADUALLY BUILDS EASTWARD...CIGS SHOULD ALSO
GRADUALLY IMPROVE...GOING VFR BY EARLY EVENING.

KREIN

//ORD AND MDW CONFIDENCE...UPDATED 20Z...

* MODERATE-HIGH CONFIDENCE IN CIG TRENDS.
* HIGH CONFIDENCE IN WIND FORECAST.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.

KREIN

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

 * WEDNESDAY NIGHT...VFR.
 * THURSDAY...VFR. CHC LGT SN WITH MVFR IN THE EVENING.
 * FRIDAY...CHC SHSN IN THE MORNING.
 * SATURDAY...SLT CHC OF RA/SN WITH MVFR POSSIBLE.
 * SUNDAY...CHC RA/SN. MVFR POSSIBLE.
 * MONDAY...VFR.

KJB

&&

.MARINE...

153 PM...LOW PRESSURE NEAR LAKE ERIE WILL CONTINUE TO LIFT
NORTHEAST TONIGHT AND INTO QUEBEC WEDNESDAY MORNING WHILE A LARGE
RIDGE OF HIGH PRESSURE EXTENDS FROM JAMES BAY SOUTHWEST INTO THE
CENTRAL PLAINS. THE GRADIENT BETWEEN THESE TWO FEATURES WILL
REMAIN STRONG BUT SLOWLY WEAKEN TONIGHT. SPEEDS/GUSTS PEAKED MID
MORNING AND EXPECT GALES IN THE 40-45 KT RANGE FOR MUCH OF THE
EVENING...BUT THREAT FOR STORM FORCE GUSTS TO 50 KT APPEARS TO
HAVE ENDED.

THE RIDGE NOTED ABOVE WILL SPLIT TONIGHT AS ONE AREA MOVES EAST
ACROSS NORTHERN QUEBEC AND THE SOUTHERN AREA DROPS SOUTH ACROSS THE
SOUTHERN PLAINS AND OHIO VALLEY WEDNESDAY. THE NORTHERN PORTION OF
THIS RIDGE WILL MOVE ACROSS LAKE MICHIGAN WEDNESDAY AFTERNOON WITH
WIND SPEEDS RAPIDLY DIMINISHING WEDNESDAY MORNING AND BECOMING
SOUTHWEST BY EVENING.

A WEAK LOW WILL DEVELOP OVER THE PLAINS WEDNESDAY NIGHT AND QUICKLY
MOVE ACROSS THE NORTHERN LAKES REGION THURSDAY AFTERNOON...
DRAGGING A COLD FRONT ACROSS THE LAKE THURSDAY NIGHT. THE GRADIENT
TIGHTENS BEHIND THIS FRONT AS STRONG HIGH PRESSURE BUILDS ACROSS
THE PLAINS. BUT IN ADDITION TO THE TIGHTENING GRADIENT...COLDER
AIR WILL ALSO BE SPREADING ACROSS THE REGION AND EXPECT NORTHERLY
WINDS GUSTING TO AT LEAST 30 KTS WITH THE POTENTIAL FOR SOME GUSTS
TO 35 KTS. THIS HIGH THEN QUICKLY MOVES EAST ON FRIDAY WITH
SOUTHERLY WINDS DEVELOPING OVER THE LAKE FRIDAY NIGHT AS LOW
PRESSURE LIFTS NORTH ACROSS CANADA. ANOTHER COLD FRONT THEN MOVES
ACROSS THE LAKES REGION SUNDAY. CMS

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ006-ILZ014 UNTIL 9 PM TUESDAY.

     LAKESHORE FLOOD ADVISORY...ILZ006-ILZ014 UNTIL 10 AM
     WEDNESDAY.

IN...LAKESHORE FLOOD ADVISORY...INZ001-INZ002 UNTIL 3 PM WEDNESDAY.

     WIND ADVISORY...INZ001-INZ002 UNTIL 9 PM TUESDAY.

LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
     LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
     LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
     LMZ874-LMZ876-LMZ878 UNTIL 9 AM WEDNESDAY.

&&

$$









AREA FORECAST DISCUSSION

NWS INDIANAPOLIS IN

 529 PM EST TUE NOV 29 2011

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

&&

.SYNOPSIS...

THE UPPER LOW WILL MOVE INTO THE NORTHEAST USA BY WEDNESDAY
MORNING...ENDING THE PRECIPITATION ACROSS THE AREA. A COLD FRONT
WILL MOVE INTO THE AREA FOR THE WEEKEND INTO EARLY NEXT WEEK
BRINGING ANOTHER CHANCE FOR PRECIPITATION.

&&

.NEAR TERM /REST OF THIS AFTERNOON AND TONIGHT/...

FOCUS IS ON SNOW EVENT. MODELS ARE SIMILAR ENOUGH THAT A BLEND CAN
BE USED.

THERMAL PROFILES HAVE COOLED ENOUGH THAT MOST OF THE PRECIPITATION
IS SNOW ACROSS THE FORECAST AREA AT 20Z. EXCEPTIONS ARE WHERE
PRECIPITATION IS LIGHTEST WHERE IT IS STILL RAIN. THUS EXPECT SNOW
AS THE MAIN PRECIPITATION TYPE FOR THE REST OF THE PERIOD.

HEAVIEST SNOW IS FALLING IN AREAS OF STRONGEST FRONTOGENETICAL
FORCING AT 850 AND 700 MB. LATEST RUC FORECAST IS FOR THESE
HEAVIER BANDS TO REMAIN RELATIVELY STATIONARY FOR THE NEXT FEW
HOURS BEFORE MOVING EAST THIS EVENING. THESE BANDS ARE MAINLY
WHERE THE WINTER WEATHER ADVISORY ALREADY EXISTS.

HOWEVER RECENT TRENDS ARE TO GO A LITTLE FARTHER SOUTH WITH THE
HEAVIER SNOW...SO WILL EXPAND THE ADVISORY ONE MORE TIER OF
COUNTIES SOUTH INTO INDIANAPOLIS PROPER....ESPECIALLY SINCE SNOW
WILL BE FALLING IN RUSH HOUR THERE.

BASED ON WHAT HAS ALREADY FALLEN...SOME MELTING...AND WHAT WILL
FALL THIS EVENING KEPT STORM TOTAL AMOUNTS NEAR 4 INCHES ACROSS
THE FAR NORTH TO 1 TO 2 INCHES ALONG I-70 AND LOWER AMOUNTS SOUTH.

FORCING QUICKLY EXITS THE AREA THIS EVENING SO WILL ONLY GO
CHANCE POPS AFTER 06Z.

MOS LOOKS TOO COLD WITH LOW TEMPERATURES GIVEN EXPECTED CLOUD
COVER...SO WENT CLOSER TO ENSEMBLE MEANS.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...

FOCUS IS ON SKY EARLY THEN ON TEMPERATURES. MODELS ARE SIMILAR SO
USED A BLEND.

FORCING WILL BE FAR ENOUGH EAST BY WEDNESDAY MORNING SO THAT CAN
GO DRY ALL AREAS. LOOKING AT LOW LEVEL RELATIVE HUMIDITY
FORECASTS....BELIEVE THAT LOW CLOUDS WILL HANG AROUND UNTIL MID
DAY...ESPECIALLY EAST. THESE WILL KEEP TEMPERATURES CLOSER TO THE
COOLER MAV MOS MOST AREAS.

HIGH PRESSURE WILL THEN PROVIDE DRY CONDITIONS INTO THURSDAY
NIGHT. MAV MOS LOOKS LIKE A COOL OUTLIER FOR LOWS WEDNESDAY NIGHT
SO WENT CLOSER TO THE MET AND ENSEMBLE MEANS. USED A BLEND OF MOS
FOR THURSDAY.

A FRONT WILL MOVE INTO THE AREA LATE THURSDAY NIGHT INTO
FRIDAY...BUT FORCING IS MINIMAL WITH IT AS BEST ENERGY REMAINS
WELL TO THE NORTH. ALSO MOISTURE IS WEAK AS WELL...SO WENT DRY ON
FRIDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...

MAIN LONG TERM FOCUS WILL BE A DEEPENING UPPER TROUGH WHICH MOVES
FROM THE NORTHERN PLAINS SATURDAY TO THE GREAT LAKES BY MONDAY AND
EASTERN GREAT LAKES TO WEST VIRGINIA BY TUESDAY. MODELS ARE A
LITTLE MORE PROGRESSIVE THIS RUN...BUT STILL KEEP PRECIP JUST TO
OUR NORTHWEST SATURDAY. PRECIP WILL BEGIN MOST AREAS LATE SATURDAY
NIGHT AND MAINLY AS LIGHT RAIN. BUT I WOULD NOT RULE OUT A BRIEF
PERIOD OF SNOW IN OUR NORTH WHEN IT FIRST STARTS.

AS MENTIONED ABOVE MODELS HAVE TRENDED MORE PROGRESSIVE AND THE
TRAILING COLD FRONT SHOULD BE FAR ENOUGH EAST BY MONDAY FOR MOST
AREAS TO BE DRY BY THEN.  SOME MODELS INCLUDING HPC INDICATE A WEAK
SECONDARY SYSTEM WILL MOVE ACROSS THE SOUTHERN GREAT LAKES MONDAY
NIGHT AND WILL ADD A SLIGHT CHANCE OF SNOW SHOWERS ACROSS OUR FAR
NORTH. OTHERWISE...DRY AND COLD WEATHER WILL BE THE RULE AFTER THIS
UPCOMING WEEKEND.

&&

.AVIATION /DISCUSSION FOR THE 300000Z TAFS/...

PRECIPITATION AREA HAS BEGUN TO SHRINK IN BOTH COVERAGE AND
INTENSITY OVER THE PAST HOUR OR SO AS LIFT WITHIN THE DEFORMATION
ZONE WEAKENS AND PUSHES OFF TO THE NORTHEAST. PRECIPITATION HAS
MAINLY BEEN A MIX OF RAIN/SNOW WITH THE SNOW LINKED TO THE STRONGER
RETURNS ON THE RADAR. THIS PROCESS EXPECTED TO CONTINUE THIS EVENING
AS DEFORMATION ZONE WEAKENS. APPEARS PRECIPITATION WILL BE OVER AT
KHUF/KLAF BY ISSUANCE TIME...AND BY 300200Z-300300Z AT KIND/KBMG.
PRECIPITATION MAY STILL BE HEAVY ENOUGH FOR IFR VISIBILITY
RESTRICTIONS AT KIND/KBMG UNTIL ABOUT 300100Z.

CEILINGS EXPECTED TO IMPROVE RATHER RAPIDLY LATER THIS EVENING AS
THE PRECIPITATION ENDS. ALREADY SEEING CEILINGS 030-040 OBSERVED
JUST ACROSS THE ILLINOIS STATE LINE. EXPECTING THE LINGERING IFR
CEILINGS TO LIFT INTO A 030-040 DECK BY 300300Z.

SURFACE WIND GUSTS UP TO ABOUT 25 KTS FROM 320-350 HEADINGS EXPECTED
THROUGHOUT MOST OF THE EVENING...WITH THESE GUSTS DIMINISHING AFTER
300600Z AS PRESSURE GRADIENT LOOSENS UP.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR INZ021-
028>031-035>049.

&&

$$

SYNOPSIS...50/AH
NEAR TERM...50/AH
SHORT TERM...50/AH
LONG TERM....JH
AVIATION...JAS






AREA FORECAST DISCUSSION

NWS NORTHERN INDIANA

 403 PM EST TUE NOV 29 2011

.SHORT TERM.../TONIGHT/

...FIRST WIDESPREAD SNOW OF THE SEASON COMMENCING...

UPDATES ISSUED EARLIER GENERALLY ON TRACK WITH RAPID COOLING OF
COLUMN OCCURRING BETWEEN 18 AND 20Z. MANY LOCATIONS NOW REPORTING
SNOW OR A MIX OF SNOW/SLEET/RAIN. SNOW AMOUNTS INITIALLY MAY BE ON
LIGHTER SIDE WITH MELTING OCCURRING ON SLIGHTLY WARMER SURFACES.
HOWEVER AS UPPER LOW APPROACHES LATE THIS AFTERNOON AND EVENING AND
MESOBANDING BETTER ESTABLISHES SNOWFALL RATES SHOULD INCREASE ACROSS
MUCH OF THE WARNING AREA. SPORADIC LIGHTNING STRIKES SEEN SW OF THE
AREA IN MAIN MESOBAND WHICH WILL TRANSLATE THROUGH THE AREA INTO
TONIGHT.

HEAVIEST SNOWFALL WILL OCCUR BETWEEN 22Z TUES AND 6Z WEDS AS MAIN
DEFORMATION ZONE SHIFTS ACROSS THE FORECAST AREA. SEVERAL RUNS OF
THE HRRR HAVE SHOWN THE MAIN SWATH OF HEAVIER SNOW TO TAKE SHAPE
EITHER SIDE OF A MARION TO ANGOLA TO HILLSDALE LINE. THIS MODEL
DEPICTS UPWARDS OF 8 TO 12 INCHES OF SNOWFALL. THINK THIS IS LIKELY
OVER DONE WITH GREATER CONFIDENCE IN DECENT AREA OF 4 TO 7 INCHES OF
SNOW WITH AMOUNTS APPROACHING 8 ESPECIALLY ACROSS PORTIONS OF
NORTHEASTERN INDIANA INTO FAR SOUTHERN LWR MI AND FAR NW OHIO. WILL
LET EVE SHIFT MONITOR TRENDS OF AMOUNTS AND HEAVIEST BAND AND ADJUST
HEADLINES ACCORDINGLY. TEMPS WILL CONTINUE TO FALL AND BOTTOM OUT IN
THE UPPER 20S TO AROUND 30.

WINDS WILL ALSO INCREASE TONIGHT AS THE TIGHTLY WRAPPED LOW
CONTINUES TO MOVE AWAY. AS WE GET INTO THE OVERNIGHT HOURS THIS
COULD CAUSE SOME DRIFTING AND LOW BLOWING OF THE SNOW...BUT GIVEN
THE INITIAL WET CONTENT...NOT EXPECTED TO BE A SIG IMPACT.

&&

.LONG TERM...

MINOR ADJUSTMENTS TO THE TEMPERATURES WEDNESDAY AND WEDNESDAY NIGHT
TO TAKE INTO ACCOUNT OUR LATEST SNOWFALL FORECASTS AND EXPECTED
CLOUD COVER. HAVE NUDGED TEMPS DOWN FOR THE MAX T AND UP FROM
PREVIOUS GRIDS FOR OVERNIGHT LOW. WITH CYCLONIC FLOW OVER THE REGION
EXPECT THAT CLOUDS WILL PERSIST AND HAVE INCREASED CLOUD COVER - BUT
MAY NOT HAVE INCREASED ENOUGH FOR THURSDAY.

LONGWAVE PATTERN IS BEGINNING TO BE MUCH MORE AMPLIFIED AND THIS
SETS UP A PROGRESSIVE PATTERN OVER THE GREAT LAKES REGION BEGINNING
THURSDAY WITH ANOTHER VIGOROUS SHORTWAVE TO TO DIVE OUT OF THE
NORTHERN PLAINS BY SATURDAY...LEADING TO ANOTHER SHOT OF COLDER AIR
POISED TO DROP OUT OF THE CANADIAN PLAINS THIS COMING WEEKEND.

WITH A BRIEF WARMING TREND THU/FRI TEMPS WILL BE BELOW NORMAL
BEGINNING SAT-NEXT TUES.

WITH THE INCOMING SHORTWAVE ON SATURDAY...HAVE INCREASED POP TO MORE
CLOSELY MATCH SURROUNDING OFFICES AND WOULD EXPECT TO SEE ANOTHER
ACCUMULATING SNOWFALL DURING THE PERIOD.

&&

.AVIATION...
FLIGHT CONDITIONS WILL CONTINUE TO DETERIORATE ACROSS THE AREA
THIS AFTERNOON AND EVENING AS RAIN QUICKLY SWITCHES TO SNOW AND
BECOMES HEAVY AT TIMES. CIGS AND VSBY INTO THE IFR IF NOT LIFR
RANGE WILL OCCUR INTO THIS EVENING. PRECIP WILL BEGIN TO TAPER
AFTER 6Z BUT AT LEAST MVFR CIGS WILL PERSIST.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR INZ006>009-
     015>018-022>027-032>034.

     WINTER WEATHER ADVISORY UNTIL 1 AM EST /MIDNIGHT CST/ WEDNESDAY
     FOR INZ004-005-012>014-020.

MI...WINTER STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR MIZ080-081.

     WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR MIZ078-079.

OH...WINTER STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR OHZ001-002-004-
     015.

LM...GALE WARNING UNTIL 10 AM EST WEDNESDAY FOR LMZ043-046.

&&

$$

SHORT TERM...FISHER
LONG TERM...LEWIS
AVIATION...SKIPPER






AREA FORECAST DISCUSSION

NWS INDIANAPOLIS IN

 330 PM EST TUE NOV 29 2011

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW

&&

.SYNOPSIS...

THE UPPER LOW WILL MOVE INTO THE NORTHEAST USA BY WEDNESDAY
MORNING...ENDING THE PRECIPITATION ACROSS THE AREA. A COLD FRONT
WILL MOVE INTO THE AREA FOR THE WEEKEND INTO EARLY NEXT WEEK
BRINGING ANOTHER CHANCE FOR PRECIPITATION.

&&

.NEAR TERM /REST OF THIS AFTERNOON AND TONIGHT/...

FOCUS IS ON SNOW EVENT. MODELS ARE SIMILAR ENOUGH THAT A BLEND CAN
BE USED.

THERMAL PROFILES HAVE COOLED ENOUGH THAT MOST OF THE PRECIPITATION
IS SNOW ACROSS THE FORECAST AREA AT 20Z. EXCEPTIONS ARE WHERE
PRECIPITATION IS LIGHTEST WHERE IT IS STILL RAIN. THUS EXPECT SNOW
AS THE MAIN PRECIPITATION TYPE FOR THE REST OF THE PERIOD.

HEAVIEST SNOW IS FALLING IN AREAS OF STRONGEST FRONTOGENETICAL
FORCING AT 850 AND 700 MB. LATEST RUC FORECAST IS FOR THESE
HEAVIER BANDS TO REMAIN RELATIVELY STATIONARY FOR THE NEXT FEW
HOURS BEFORE MOVING EAST THIS EVENING. THESE BANDS ARE MAINLY
WHERE THE WINTER WEATHER ADVISORY ALREADY EXISTS.

HOWEVER RECENT TRENDS ARE TO GO A LITTLE FARTHER SOUTH WITH THE
HEAVIER SNOW...SO WILL EXPAND THE ADVISORY ONE MORE TIER OF
COUNTIES SOUTH INTO INDIANAPOLIS PROPER....ESPECIALLY SINCE SNOW
WILL BE FALLING IN RUSH HOUR THERE.

BASED ON WHAT HAS ALREADY FALLEN...SOME MELTING...AND WHAT WILL
FALL THIS EVENING KEPT STORM TOTAL AMOUNTS NEAR 4 INCHES ACROSS
THE FAR NORTH TO 1 TO 2 INCHES ALONG I-70 AND LOWER AMOUNTS SOUTH.

FORCING QUICKLY EXITS THE AREA THIS EVENING SO WILL ONLY GO
CHANCE POPS AFTER 06Z.

MOS LOOKS TOO COLD WITH LOW TEMPERATURES GIVEN EXPECTED CLOUD
COVER...SO WENT CLOSER TO ENSEMBLE MEANS.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...

FOCUS IS ON SKY EARLY THEN ON TEMPERATURES. MODELS ARE SIMILAR SO
USED A BLEND.

FORCING WILL BE FAR ENOUGH EAST BY WEDNESDAY MORNING SO THAT CAN
GO DRY ALL AREAS. LOOKING AT LOW LEVEL RELATIVE HUMIDITY
FORECASTS....BELIEVE THAT LOW CLOUDS WILL HANG AROUND UNTIL MID
DAY...ESPECIALLY EAST. THESE WILL KEEP TEMPERATURES CLOSER TO THE
COOLER MAV MOS MOST AREAS.

HIGH PRESSURE WILL THEN PROVIDE DRY CONDITIONS INTO THURSDAY
NIGHT. MAV MOS LOOKS LIKE A COOL OUTLIER FOR LOWS WEDNESDAY NIGHT
SO WENT CLOSER TO THE MET AND ENSEMBLE MEANS. USED A BLEND OF MOS
FOR THURSDAY.

A FRONT WILL MOVE INTO THE AREA LATE THURSDAY NIGHT INTO
FRIDAY...BUT FORCING IS MINIMAL WITH IT AS BEST ENERGY REMAINS
WELL TO THE NORTH. ALSO MOISTURE IS WEAK AS WELL...SO WENT DRY ON
FRIDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...

MAIN LONG TERM FOCUS WILL BE A DEEPENING UPPER TROUGH WHICH MOVES
FROM THE NORTHERN PLAINS SATURDAY TO THE GREAT LAKES BY MONDAY AND
EASTERN GREAT LAKES TO WEST VIRGINIA BY TUESDAY. MODELS ARE A
LITTLE MORE PROGRESSIVE THIS RUN...BUT STILL KEEP PRECIP JUST TO
OUR NORTHWEST SATURDAY. PRECIP WILL BEGIN MOST AREAS LATE SATURDAY
NIGHT AND MAINLY AS LIGHT RAIN. BUT I WOULD NOT RULE OUT A BRIEF
PERIOD OF SNOW IN OUR NORTH WHEN IT FIRST STARTS.

AS MENTIONED ABOVE MODELS HAVE TRENDED MORE PROGRESSIVE AND THE
TRAILING COLD FRONT SHOULD BE FAR ENOUGH EAST BY MONDAY FOR MOST
AREAS TO BE DRY BY THEN.  SOME MODELS INCLUDING HPC INDICATE A WEAK
SECONDARY SYSTEM WILL MOVE ACROSS THE SOUTHERN GREAT LAKES MONDAY
NIGHT AND WILL ADD A SLIGHT CHANCE OF SNOW SHOWERS ACROSS OUR FAR
NORTH. OTHERWISE...DRY AND COLD WEATHER WILL BE THE RULE AFTER THIS
UPCOMING WEEKEND.

&&

.AVIATION /DISCUSSION FOR 29/18Z TAF ISSUANCE/...

VERY POOR FLYING CONDITIONS WILL CONTINUE INTO THIS EVENING AND
IMPROVE OVERNIGHT AND EARLY WEDNESDAY TO VFR. STRONG LOW PRESSURE
OVER NORTHERN OHIO WILL CONTINUE MOVING NORTHEAST ACROSS THE EASTERN
GREAT LAKES INTO SOUTHEAST CANADA. AS COLDER AIR WRAPS INTO OUR
REGION...A MIXTURE OF RAIN AND SOME SLEET WILL CHANGE TO ALL SNOW BY
MID OR LATE AFTERNOON. PRECIPITATION WILL BEGIN DIMINISHING WEST TO
EAST THIS EVENING AND WILL END ALL AREAS BY 06Z LEAVING MVFR
CEILINGS OVERNIGHT.

DRIER AIR WILL GRADUALLY MOVE IN LATE TONIGHT AND WEDNESDAY
IMPROVING CONDITIONS TO VFR OVER WESTERN SECTIONS LATE TONIGHT AND
EVEN INDY BY 13Z WEDNESDAY. CLEAR SKIES ARE POSSIBLE SOME AREAS BY
END OF THE TAF PERIOD.

A STRONG PRESSURE GRADIENT WILL CAUSE WINDS TO BECOME NORTHWEST 15
KNOTS WITH GUSTS TO 25 KNOTS BY LATE AFTERNOON. WINDS WILL GRADUALLY
DIMINISH OVERNIGHT AND WEST TO NORTHWEST WINDS OF 10 KNOTS OR LESS
WILL BE THE RULE WEDNESDAY.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR INZ021-
028>031-035>049.

&&

$$

SYNOPSIS...50/AH
NEAR TERM...50/AH
SHORT TERM...50/AH
LONG TERM....JH
AVIATION...JH





AREA FORECAST DISCUSSION

NWS NORTHERN INDIANA

 125 PM EST TUE NOV 29 2011

.UPDATE...
ZONES/GRIDS WERE UPDATED EARLIER TO UPGRADE PORTIONS OF THE WATCH
TO A WARNING WITH REMAINING COUNTIES UNDER AN ADVISORY.

AREA IN INCREASED ASCENT AND LOCALIZED WAA HAS OCCURRED ACROSS
PORTIONS OF NW OHIO SW INTO WESTERN INDIANA BY LAFAYETTE. RAIN HAS
BEEN MIXING AT TIMES WITH SLEET AS COLDER AIR CONTINUES TO
STRUGGLE WITH SHALLOW WAA IN LOWER LEVELS. AS DYNAMIC COOLING
COMMENCES SLEET WILL BECOME MORE PREDOMINATE AND THEN SWITCH TO
SNOW. SWOMCD ISSUED RECENTLY HIGHLIGHTING INCREASING CONCERN FOR
HEAVY SNOW ACROSS MUCH OF THE FORECAST AREA...ESPECIALLY IN NE
INDIANA AND NW OHIO WITH ONE INCH OR MORE PER HOUR RATES POSSIBLE.
ADDITIONAL MESOSCALE DETAILS CAN BE FOUND IN THIS PRODUCT. THE BIG
CHALLENGE IS WHEN EXACTLY THE SWITCH OVER OCCURS AND HOW LONG THE
BAND PERSISTS ACROSS THE AREA AS THE UPPER LOW QUICKLY EXITS.
ALTHOUGH EXTREME AMOUNTS ARE NOT EXPECTED...GENERAL SWATH OF 4 TO
6 INCHES WITH LOCALLY HIGHER AMOUNTS LOOK TO OCCUR FROM EAST OF A
LOGANSPORT TO WARSAW TO COLDWATER LINE. ALTHOUGH GENERALLY UNDER
TYPICAL CRITERIA...TIMING OF HEAVIEST SNOW COINCIDING WITH
AFTERNOON/EVENING RUSH HOUR...COMBINED WITH FIRST WIDESPREAD
SNOWFALL...WARRANTED A BIT MORE AGGRESSIVE HANDLE ON HEADLINES. AS
A RESULT HAVE UPGRADED TO WARNING IN THESE AREA WITH EASTERN
FRINGE GOING JUST TO THE EAST OF I-69. FAR EASTERN PORTIONS OF THE
WARNING MAY SEE A BIT MORE SLEET THAN OTHERS BEING CLOSER TO
WARMEST AIR BUT STILL SHOULD SQUEEZE OUT ENOUGH SNOW TO BE OF
CONCERN. WEST OF THE ABOVE MENTIONED LINE...WINTER WEATHER
ADVISORY HAS BEEN ISSUED FOR THE TIME BEING WITH CONTINUED
MONITORING AS SNOW BAND UNFOLDS.

&&

.AVIATION...
FLIGHT CONDITIONS WILL CONTINUE TO DETERIORATE ACROSS THE AREA
THIS AFTERNOON AND EVENING AS RAIN QUICKLY SWITCHES TO SNOW AND
BECOMES HEAVY AT TIMES. CIGS AND VSBY INTO THE IFR IF NOT LIFR
RANGE WILL OCCUR INTO THIS EVENING. PRECIP WILL BEGIN TO TAPER
AFTER 6Z BUT AT LEAST MVFR CIGS WILL PERSIST.

&&

.PREV DISCUSSION... /ISSUED 1000 AM EST TUE NOV 29 2011/

HYDROLOGY...
HAVE UPDATED THE FLOOD WATCH TO AN AREAL FLOOD WARNING FOR THE
ENTIRE AREA. SATURATED GROUND FROM EARLIER RAINFALL HAS CAUSED
THE ADDITIONAL RAINFALL TO RUNOFF AND PRODUCE SOME FLOODING OF
ROADS AND RAPID RISES ON STREAMS. ADDITIONAL RAINFALL OF 1 TO
2 INCHES AND EVEN MELTED SNOW LATER TODAY IS EXPECTED TO CAUSE
WIDESPREAD AREAL FLOODING LATER TODAY.

PREV DISCUSSION... /ISSUED 446 AM EST TUE NOV 29 2011/

SHORT TERM...
DYNAMIC/IMPRESSIVE SRN STREAM WAVE CONTS TO WRAP UP ACRS WRN TN
EARLY THIS MORNING W/MATURE INTENSE TROWAL TO ITS NORTH. WIDESPREAD
MOD-HVY RAIN WAS ONGOING ACRS MUCH OF THE CWA W/HEAVIEST BANDED PCPN
ORIENTED SW-NE THROUGH ACRS THE NW HALF.

COMPLEX/MULTI-FACETED FCST GOING FWD FOR TDA AND TONIGHT. COLD CORE
LOW OVR WRN TN WILL LIFT OUT NEWD THROUGH WRN OH AND DEEPEN THROUGH LT
AFTN IN RESPONSE TO UPSTREAM NRN STREAM TROUGH MAKING QUICK EWD
PROGRESS ACRS THE UPR MIDWEST. IN FACT FULL GAMUT OF 00Z GUIDANCE
TRENDED QUICKER W/RAIN-SNOW CHG OVR AND IN LIFTING THIS DEEP SYS OUT
W/VAPOR INDICATING FTR BEGINNING TO GET PICKED UP W/RAIN CHG TO SNOW
NOW INTO SE MO/SRN IL. HWVR MODEL INTRICACIES ABOUND ESP W/TIMING OF
CHG OVR AND PLACEMENT OF MOST INTENSE PORTION OF MID LVL DEFORMATION
BAND. EARLY CONJECTURE HERE GIVES A NOD TO MODELS THAT IMPLY A
FASTER CHG OVR/WWD PLACEMENT GIVEN NRN STREAM TROUGH IS SLIGHTLY EWD
OF PRIOR 03Z RUC GUIDANCE AND QUICKER W/INFILTRATION OF LL CAA WING
ADVTG SWWD WITHIN RAPIDLY INCREASING LL AGEOSTROPHIC FLW THROUGH MID
MORNING W/CORRESPONDING SUBSEQUENT FASTER ARRIVAL OF COLD POCKET
ALOFT FULLY ANTICIPATED. THIS WILL ESSENTIALLY OVERWHELM TROWAL WARM
NOSE AND LEAD TO RAPID MIX TWD HEAVY SNOW BTWN 17-20Z SW-NE ACRS THE
WRN 2/3RDS OF CWA TIED TO MAXIMIZING VERTICAL ASCENT WITHIN MID LVL
DEFORMATION ZONE ALG NOSE OF ASCENDING WARM CONVEYOR BELT. AND THUS
THE CHALLENGE OF THE DAY IS WHAT TO DO W/SNOW AMOUNTS.

BLENDED MULTI-MODEL QPF WAS UTILIZED TO DAMPEN MUCH HIGHER HIGHRES
GUIDANCE WHILE OFFSETTING LWR BOUND SPECTRAL GUIDANCE. THIS GIVES SIMILAR
AMOUNTS W/HPC YET PREFER A HEDGE WWD PLACEMENT OF MORE SIG SNOW BAND.
THROUGH 05Z...5 INCH AMOUNTS HAVE BEEN REPORTED ACRS WRN TN. HIGHER
AMOUNTS ARE CERTAINLY PLAUSIBLE...EVEN LIKELY...ESP CONSIDERING ALL
HIGHRES SOLUTIONS IMPLYING LOW TOPPED CONVN THIS AFTN WITHIN MID LVL
DEFORMATION ZONE ACRS NRN IN/SRN MI AND SREF PROBS OF 1+ INCH/HR
SNOW RATES EXCEED 70% THIS AFTN AND EVENING AND 2+ PROBS EXCEEDING
30%. NR TERM 06Z RUNS OF HRRR/RUC BOTH CONFIRMING FASTER CHG OVR AND
DVLPMNT OF 40+ DBZ RTNS THIS AFTN WITHIN DEFORMATION ZONE THUS
W/GROWING LIKELIHOOD OF EXTREME SNOWFALL RATES...POTENTIAL ACCUMS
MAY BE SIGNIFICANTLY HIGHER THAN CURRENTLY SHOWN W/SOME EXPERIMENTAL
HIGHRES SNOW ALGORITHMS INDICATING A FOOT PLUS ALG A WARSAW TO
KALAMAZOO LINE. THUS GIVEN TIMING OF CHG OVR WILL LIKELY OCCUR WELL
BFR THE AFTN COMMUTE AND POTENTIAL FOR SHORT DURATION/6+ INCH SNOW
AMOUNTS WILL HOIST A WINTER STORM WATCH FROM EARLY AFTN THROUGH 06Z
FOR GENERALLY THE WRN 2/3RDS OF CWA. FRINGE COUNTIES ALG BOTH SIDES
ARE PROBLEMATIC ESP FAR NW WHERE DVLPMNT OF STG ISOLLABARIC FLW XPCD
THIS AFTN OFF LK MI SHLD MODIFY THE BNDRY LYR SUFFICIENTLY TO
PROMOTE MORE OF A MIX AND NEGLIGIBLE ACCUMS...AND EAST W/SPECTRAL
MODEL CONSENSUS MUCH SLWR LIFTING INTENSE DEFORMATION ZONE BAND OUT
THIS EVENING. THUS THE NOD TWD A WATCH VS WARNING AT THIS POINT AND
IN LIGHT OF CHG OVR TIMING UNCERTAINTIES STILL.

REGARDLESS WHAT IS LEFT OF MID LVL DEFORMATION ZONE...LEFTOVERS
WILL RAPIDLY LIFT OUT/BREAK DOWN TWD LT EVENING/EARLY MORNING W/SNOW
ENDING QUICKLY W-E. CLDS SHLD HOLD THOUGH WITHIN LL THERMAL TROUGH
AND FLW NW LL FLW OFF THE LAKE AND WILL HOLD W/WARMER MIN BLEND
OVERNIGHT.

LONG TERM...WEDNESDAY THROUGH MONDAY

ONLY MINOR TWEAKS MADE TO THE FCST AS LATEST GUIDANCE IS SIMILAR TO
PREVIOUS GUIDANCE AND INHERITED GRIDS. A REPRIEVE FROM THE WET/WHITE
WX ANTICIPATED WEDNESDAY INTO THURSDAY AS HEIGHT RISES/SHORTWAVE
RIDGING ENSUES BEHIND TODAY`S POWERHOUSE SYSTEM. WEDNESDAY WILL
START OUT MAINLY CLOUDY (ESPECIALLY EAST) AND BREEZY...WITH CLEARING
AND DIMINISHING WINDS BY AFTERNOON. WAA ALOFT WILL BE OFFSET BY
SHALLOW MIXING AND SNOW COVER OVER MUCH OF THE AREA. WITH THIS OPTED
FOR COOLER GUIDANCE EACH DAY.

MORNING WATER VAPOR LOOP SHOWS A POTENT NORTHERN STREAM SHORTWAVE
TROUGH NEAR 145W IN THE NE PAC. THIS FEATURE WILL DIG INTO THE
WESTERN CONUS BY WEDNESDAY...WITH ENSEMBLES CONTINUING TO INDICATE
AN UPPER TROUGH FRACTURE BY THIS TIME. THE MOISTURE STARVED AND
SOMEWHAT SHEARED NRN PIECE OF THIS WAVE LOOKS TO PROPAGATE RAPIDLY
EWD THROUGH THE GREAT LAKES BY THURSDAY NIGHT/FRIDAY MORNING.
ECMWF/GFS 5-3H Q-VECTOR PROGS POINT TO A BRIEF PERIOD OF LARGE SCALE
ASCENT BYPASSING MAINLY TO THE NORTH DURING THIS TIME. AS A
RESULT...NOT EXPECTING MUCH IN THE WAY OF PRECIP BEHIND THE
ATTENDANT CDFNT LOCALLY. OPTED TO LOWER POPS TO SLIGHT CHC FOR THE
POSSIBILITY OF A FEW LGT SNOW SHOWERS.

GREATER AMPLIFICATION OF A NE PAC RIDGE WILL SUPPORT DOWNSTREAM
AMPLIFICATION THIS WEEKEND...ALLOWING ANOTHER POSITIVELY TILTED NRN
STREAM UPPER TROUGH TO DIG INTO THE CENTRAL CONUS. THIS GREATER
AMPLIFICATION WILL HELP FORCE A SRN STREAM LEAD SHORTWAVE NEWD
TOWARDS THE GREAT LAKES BY SATURDAY NIGHT/SUNDAY...BRINGING WITH IT
A BETTER CHC FOR MORE WIDESPREAD PRECIPITATION BY THIS TIME. AS
EXPECTED THIS FAR IN ADVANCE...STILL LOW CONFIDENCE WRT TO DETAILS
(TRACK/TIMING/AMPLITUDE/ETC) SO WILL RETAIN CHC POPS AND FAVOR THE
MORE CONSISTENT ECMWF WHICH HINTS AT A FARTHER NW TRACK AND MAINLY
RAIN LOCALLY. OTHERWISE...TEMPS FOR THE ENTIRE PERIOD ARE FCST TO
GENERALLY BE AT OR BELOW NORMAL.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR INZ006>009-
     015>018-022>027-032>034.

     WINTER WEATHER ADVISORY UNTIL 1 AM EST /MIDNIGHT CST/ WEDNESDAY
     FOR INZ004-005-012>014-020.

MI...WINTER STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR MIZ080-081.

     WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR MIZ078-079.

OH...WINTER STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR OHZ001-002-004-
     015.

LM...GALE WARNING UNTIL 10 AM EST WEDNESDAY FOR LMZ043-046.

&&

$$

SHORT TERM...T
LONG TERM...STEINWEDEL
AVIATION...SKIPPER/FISHER
UPDATE...FISHER






AREA FORECAST DISCUSSION

NWS TOPEKA KS

 331 PM CST TUE NOV 29 2011

.DISCUSSION...

SHORT RANGE FORECAST (TONIGHT AND WEDNESDAY)...

20Z WATER VAPOR IMAGERY AND ASSOCIATED 500 MB RUC ANALYSIS SHOWS A
DEEP CUT OFF LOW PRESSURE SYSTEM SLOWLY MOVING NORTHEASTWARD THROUGH
THE OHIO RIVER VALLEY...BRINGING NORTHWESTERLY MID LEVEL FLOW OVER
THE CENTRAL U.S. A SHORTWAVE TROUGH EMBEDDED WITHIN THE NORTHWEST
FLOW IS CURRENTLY PUSHING THROUGH THE AREA...HOWEVER MEAGER LIFT
FROM THIS QUICKLY MOVING SHORTWAVE WILL ONLY BRING SOME SCATTERED
HIGH CLOUDS FOR THIS AFTERNOON. AT THE SURFACE A SURFACE RIDGE OF
HIGH PRESSURE CURRENTLY SITS OVER CENTRAL KANSAS CREATING TIGHT
GRADIENT WITH SUBSEQUENT GUSTY NORTH-NORTHWEST WINDS ACROSS FAR
EASTERN KANSAS. A NARROW BAND OF DRY AIR HAS MOVED INTO NORTH
CENTRAL KANSAS AS DEWPOINTS HAVE MIXED INTO THE SINGLE
DIGITS...HOWEVER DUE TO THE LIGHT WINDS NEAR THE CENTER OF THE
SURFACE HIGH...FIRE DANGER IS NOT VERY HIGH IN THIS AREA DESPITE THE
VERY DRY AIR.

OVERNIGHT THE SURFACE RIDGE MOVES OVER NORTHEAST KANSAS CAUSING
WINDS TO GO CALM. WITH SKIES CLEARING OUT RADIATIONAL COOLING WILL
ALLOW TEMPERATURES TO DROP INTO THE LOWER TO MID 20S. WOULD HAVE
GONE A LITTLE COOLER IN NORTH CENTRAL KANSAS BUT SOUTHERLY FLOW
ALONG THE WESTERN EDGE OF THE EASTWARD MOVING SURFACE RIDGE WILL
ALLOW FOR SOME WEAK WARM AIR ADVECTION AS WELL AS SOME BOUNDARY
LAYER MIXING. THESE FACTORS WILL HELP TO KEEP TEMPERATURES A LITTLE
WARMER THAN AREAS FURTHER EAST. LOW LYING AREAS AND RIVER VALLEYS
EAST OF HIGHWAY 75 COULD SEE TEMPS DROP INTO THE UPPER TEENS AS
SOUTHERLY FLOW WILL LIKELY NOT BEGIN IN THESE AREAS UNTIL EARLY WED
MORNING.

WEDNESDAY WILL BRING ANOTHER MOSTLY CLEAR DAY WITH SLIGHTLY WARMER
TEMPERATURES THAN TUESDAY. SOUTHERLY FLOW WILL ALLOW FOR WARM AIR
ADVECTION EAST OF A DEEPENING SURFACE TROUGH WHICH WILL COME OFF THE
WESTERN HIGH PLAINS AND MOVE EAST INTO THE CENTRAL PLAINS. UTILIZED
A MIX DOWN METHOD FROM THE 900 MB LEVEL FOR WEDNESDAYS HIGHS.
TIGHTENING SURFACE PRESSURE GRADIENT BETWEEN THE DEEPENING LOW AND
THE DEPARTING SURFACE HIGH WILL CAUSE THE SOUTHERLY WINDS TO PICK UP
IN INTENSITY THROUGHOUT THE DAY ON WEDNESDAY.

JL

EXTENDED RANGE FORECAST (WEDNESDAY NIGHT THROUGH TUESDAY)...

AN UPPER LEVEL TROUGH WILL DIG SOUTHWARD ACROSS THE WESTERN CONUS
INTO THE DESERT SOUTHWEST BY THURSDAY EVENING. A MINOR H5 WILL MOVE
EAST ACROSS THE NORTHERN AND CENTRAL PLAINS WEDNESDAY NIGHT.
LOW-LEVEL CAA ACROSS THE NORTHERN PLAINS WILL CAUSE A SURFACE COLD
FRONT TO PUSH SOUTHWARD ACROSS THE CWA THURSDAY MORNING. HIGHS MAY
OCCUR DURING THE MID AND LATE MORNING HOURS ON THURSDAY ACROSS
SOUTHEAST KS...WITH TEMPERATURES HOLDING STEADY OR SLOWLY FALLING
INTO THE LOWER 40S BY AFTERNOON. NORTH WINDS WILL INCREASE 20 TO 25
MPH WITH GUSTS OF 35 TO 45 MPH BEHIND THE COLD FRONT. THERE MAY BE
SOME SNOW FLURRIES EARLY THURSDAY MORNING ACROSS THE NORTHERN
COUNTIES OF THE CWA.

FRIDAY...WILL BE COOL WITH INCREASING HIGH CLOUDINESS. WINDS WILL
SHIFT TO THE SOUTHEAST BY LATE AFTERNOON AS A LEE SFC TROUGH DEEPENS
ACROSS THE HIGH PLAINS. HIGHS ON FRIDAY WILL ONLY REACH THE MID TO
UPPER 30S. THE NAM MODEL SOLUTION HAS BEEN VERY INCONSISTENT AND
ERRONEOUS THE PAST 48 HOURS. THE NAM IS WAY TOO PROGRESSIVE LIFTING
THE CLOSED UPPER LOW INTO THE SOUTHERN HIGH PLAINS LATE FRIDAY
AFTERNOON. IF FOR SOME REASON IT WERE TO VERIFY THEN PRECIP MAY
BEGIN DEVELOPING ACROSS THE SOUTHERN COUNTIES OF THE CWA LATE FRIDAY
AFTERNOON AND SPREAD NORTHWARD INTO THE EARLY EVENING HOURS. ALL
OTHER OPERATIONAL NUMERICAL MODELS SHOW THE CLOSED UPPER LOW
REMAINING ACROSS THE DESERT SOUTHWEST INTO FRIDAY NIGHT.

FRIDAY NIGHT THROUGH SATURDAY NIGHT...A PIECE OF THE UPPER LOW
ACROSS THE DESERT SOUTHWEST WILL LIFT NORTHEAST INTO THE CENTRAL
PLAINS ON SATURDAY. THE ECMWF MODEL SHOWS STRONG WAA DEVELOPING
FRIDAY NIGHT WHICH SHOULD CAUSE SFC TEMPS AND DEWPOINTS TO RISE
ABOVE FREEZING ACROSS MUCH OF THE CWA BY 6Z SAT. THE GFS AND GEM
HAVE BEEN CONVERGING TOWARDS THE ECMWF...BUT CONTINUE TO BE A BIT
COOLER. I WILL BE LEANING A BIT MORE TOWARDS THE ECMWF DURING THIS
FORECAST PERIOD. LOW TEMPERATURES WILL OCCUR DURING THE MID EVENING
HOURS OF FRIDAY...THEN SLOWLY RISE THROUGH THE NIGHT. ISENTROPIC
LIFT AND ASCENT AHEAD OF THE APPROACHING H5 TROUGH WILL CAUSE LIGHT
RAIN TO DEVELOP. IF THERE IS ENOUGH LOW-LEVEL DRY AIR IN PLACE AS
THE RAIN DEVELOPS THEN WET-BULB COOLING MAY ALLOW SURFACE
TEMPERATURES ACROSS THE NORTHERN AND WESTERN COUNTIES TO DROP BELOW
FREEZING. THERE MAY BE SOME LIGHT PERIODS OF FREEZING RAIN FRIDAY
EVENING BEFORE IT CHANCES TO LIGHT RAIN. ROAD SURFACE ARE FAIRLY
WARM...THUS THE ONLY SLICKS SPOTS THAT MAY DEVELOP FRIDAY EVENING
MAY BE ON BRIDGES AND OTHER ELEVATED ROAD SURFACES.

THE RAIN ON SATURDAY MAY BEGIN TO MIX WITH SNOW ACROSS NORTH CENTRAL
KS DURING THE AFTERNOON HOURS AS THE H5 TROUGH LIFTS NORTHEAST
ACROSS CENTRAL KS INTO EASTERN NE. THE NORTHERN COUNTIES MAY SEE A
PERIOD OF LIGHT SNOW SATURDAY NIGHT...THE RAIN WILL MIX WITH SNOW
ACROSS THE REMAINDER OF THE CWA THROUGH THE EVENING HOURS. THERE MAY
BE A BRIEF PERIOD OF LIGHT SNOW ACROSS NORTHEAST AND EAST CENTRAL KS
BEFORE THE PRECIP MOVES EAST OF THE CWA LATE SATURDAY NIGHT INTO
SUNDAY MORNING. ATTM...THE ACCUMULATING SNOW WILL MOST LIKELY
REMAIN WEST AND NORTH OF THE CWA...FROM WEST CENTRAL KS INTO EASTERN
NE WHERE SEVERAL INCHES OF SNOW MAY ACCUMULATE. THE NORTH CENTRAL
COUNTIES MAY SEE AROUND AN INCH OF SNOW ON GRASSY SURFACES SATURDAY
NIGHT. HIGHS ON SATURDAY WILL REACH THE LOWER TO MID 40S SOUTH OF
I-70 WITH MID TO UPPER 30S NORTH OF I-70. OVERNIGHT LOWS ON SATURDAY
WILL SLOWLY DROP INTO THE 20S.

SUNDAY THROUGH TUESDAY...THE MAIN H5 LOW WILL REMAIN CUTOFF ACROSS
THE SOUTHWEST CONUS AS A LONGER WAVE LENGTH H5 TROUGH DEVELOPS
ACROSS THE EASTERN CONUS. NORTHWEST FLOW ALOFT AND A COLD SFC HIGH
PRESSURE WILL KEEP HIGHS IN THE MID 30S AND OVERNIGHT LOWS IN THE
TEENS AND LOWER 20S.

GARGAN

&&

.AVIATION...

VFR CONDITIONS EXPECTED THROUGH NEXT 24 HOURS...WITH WINDS
SWITCHING FROM THE NORTH TO SOUTH AROUND 09 Z ON WEDNESDAY MORNING.

JL

&&

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

$$








AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 1253 PM EST TUE NOV 29 2011

.SYNOPSIS...
LOW PRESSURE WILL MOVE ACROSS THIS AFTERNOON AND TONIGHT. SOME LIGHT
RAIN AND SNOW SHOWERS THROUGH EARLY WEDNESDAY MORNING. HIGH PRESSURE
THURSDAY. MOISTURE STARVED FRONT FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
915 AM UPDATE. NEW COMMA SHAPED AREA OF RAIN HAS QUICKLY DEVELOPED
OVER SOUTHERN THIRD OF CWA IN RESPONSE TO YET ANOTHER IMPULSE
ROTATING AROUND APPROACHING UPPER LOW OVER THE TENNESSEE VALLEY.
THIS WILL SHIFT NORTH THIS MORNING AND MAINLY BE NORTH OF OUR CWA BY
EARLY AFTERNOON. HAVE UPPED POPS WITH THIS FEATURE THRU EARLY
AFTERNOON. THEN...PER CURRENT FORECAST...SHOWERS DEVELOP LATER THIS
AFTERNOON UNDER THE UPPER LOW. ALSO TWEAKED TEMPS DOWNWARD PER
CURRENT TEMPS AND TRENDS UPSTREAM.

PREVIOUS DISCUSSION BELOW...
FRONT AS 0830Z HAD JUST PASSED UNI-3I2-CRW-BKW LINE...WITH BRIEF GUSTS
NEAR 25KTS ON NARROW ELEVATED CONVECTIVE BAND. HAVE OCCLUDED FRONT
CLEARING CENTRAL LOWLANDS NEXT HR AND SE OH/NORTHERN WV LOWLANDS BY
12Z. BOUNDARY TAKES ON MORE OF A NW TO SE ORIENTATION IN THE
MTNS...HENCE A FEW HRS DELAY OF FROPA FROM TO S TO N. DRY SLOT
QUICKLY WORKS IN THRU MID MORNING...EFFECTIVELY SHUTTING OFF PCPN
AFTER A COUPLE HRS POST FRONTAL RAINS. THIS MAY LINGER LONGER ACROSS
SE OH AND THE NORTHERN AREAS DUE TO LAGGING NATURE OF BOUNDARY
ACROSS MTNS AND INTO VA. RAINFALL AMOUNTS TO HALF AN INCH LOOK GOOD
WITH THIS...WITH UP TO AN INCH ALONG EAST FACING SLOPES IN MTNS.

REWORKED HRLY TEMPERATURE GRIDS TDY FROM LAV AND RUC TO REFLECT MILD
READINGS AHEAD OF BOUNDARY EARLY THIS MORNING AND DROPPING TMPS WITH FROPA.
LOOKING AT A MIDNIGHT HIGH FOR ALL PLACES...WITH TEMPS DROPPING
10-15 DEGREES WITH FROPA...AND SLOWLY FALLING THROUGH 40S TDY...WITH
30S ACROSS THE HIGH TERRAIN.

DEEP UPR LOW WILL TRACK THRU EASTERN KY THIS AFTN AND INTO THE AREA
THIS EVENING. THIS WILL INCREASE THE MOISTURE DEPTH AND LIFT TO
ALLOW LIGHT PCPN TO BREAK OUT LATE THIS AFTN ACROSS SE KY AND INTO
SOUTHERN AREAS THIS EVENING BEFORE ROTATING UP THE SPINE OF MTNS
TONIGHT. DRY SLOT MAY PIVOT ARND INTO SE OH...KEEPING AREAS ALONG
AND WEST OF OH RVR DRY INTO THE EARLY PART OF THE NIGHT...BEFORE
FILLING IN TOWARD MORNING.

AREA WILL SEE THE BEST UPR LOW HAS TO OFFER WITH RESPECT TO
MAGNITUDE OF COLD POOL ALOFT. H85 TMPS BOTTOM OUT TO ARN -5C BY 12Z
WED. A MONTH FROM NOW...THERE WOULD BE NO CONCERN ABOUT PCPN TYPE
OUTSIDE OF MTNS. HOWEVER...AS IT STANDS....BL WILL BE SLOW TO COOL
THIS EVENING. MDLS SHOW BL TEMPS AND H925 TMPS WARM ENOUGH TO KEEP
THINGS LIQUID OUTSIDE OF THE MTNS UNTIL AFTER MIDNIGHT...IF NOT A
LITTLE LONGER. EVEN IN MTNS...WHERE IT SHOULD BE COLD ENOUGH FOR
SNOW...KEEP ACCUMULATIONS TO ARND AN INCH OR SO IN THE AOA
3KFT...DUE TO VERY WET AND WARM GRND. WITH SATURATION/WEAK LIFT TO NEAR
-8C...WILL KEEP DZ MENTION OUT OF GRIDS ATTM.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
MODELS SHOW SOME LINGERING MOISTURE ON WEDNESDAY. 850 MB
TEMPERATURES ARE NOT COLD ENOUGH FOR AUTO CONVECTION IN THE LOWER
LAYER...SO WILL KEEP POPS ON THE LOW SIDE. BASED ON 850 MB
TEMPERATURES AND WITH SOME CLEARING IN THE WESTERN COUNTIES DURING
THE DAY WEDNESDAY...MOS GUIDANCE IN THE WEST LOOKS A BIT TOO COLD.
HIGH PRESSURE THEN BUILDS IN FOR THURSDAY. A MOISTURE STARVED FRONT
ARRIVES ON FRIDAY...BUT BASED ON LACK OF MOISTURE IN THE
MODELS...WILL KEEP A DRY FORECAST FOR NOW.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
HAVE GONE WITH HPC THINKING FOR THIS PART OF THE FORECAST...WHICH
LEANS TOWARDS THE ECMWF/UKMET/CANADIAN SOLUTIONS. LATEST 12 UTC
GFS MODEL HAS TRENDED TOWARDS THESE SOLUTIONS AS WELL.

A WEAK COLD FRONT WILL PUSH THROUGH THE AREA ON FRIDAY.  HOWEVER...
THE AIRMASS WILL BE QUITE DRY...SO NO PRECIP IS EXPECTED WITH THIS
FEATURE.  HIGH PRESSURE WILL THEN BE IN CONTROL FOR SATURDAY AND
SATURDAY NIGHT...BEFORE A COLD FRONT APPROACHES FROM THE WEST
SUNDAY.  THE FRONT IS EXPECTED TO BE IN THE AREA ON MONDAY.

AS A RESULT...EXPECT PRECIP CHANCES WILL INCREASE BY LATE
SUNDAY...WITH CHANCES CONTINUING THROUGH THE END OF THE PERIOD.

ONLY REAL CHANGES FROM HPC THINKING WERE THE SKY GRIDS.  FELT HPC
FORECAST INCLUDED TOO MANY CLOUDS WITH DRY FRONT ON FRIDAY...SO
TWEAKED DOWNWARD.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
UPPER LOW MOVES ACROSS THE AREA TONIGHT AND WEDNESDAY MORNING.
GENERALLY WIDESPREAD MVFR CEILINGS...IFR MOUNTAINS AFTER 02Z. SCATTERED
RAIN SHOWERS CAN BE EXPECTED AT ANY TIME UNDER THE COLD POOL...BUT
MOST ORGANIZED AREA OF SHOWERS WILL BE OVER THE MOUNTAINS 00Z-06Z
AND OVER SOUTHEAST OHIO 06Z TO 12Z. RAIN SHOWERS WILL CHANGE TO SNOW
SHOWERS MOUNTAINS ABOVE 200 FEET BY 02Z AND A MIX OF RAIN AND SNOW
SHOWERS ELSEWHERE 06Z TO 12Z. IFR CEILINGS IN HEAVIER SHOWERS AND
MOUNTAINS.

AFTER 12Z WHILE SHOWERS DECREASE FROM WEST TOE EAST...MVFR CEILINGS
PREVAIL LOWLANDS...WITH IFR MOUNTAINS.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: TIMING OF ORGANIZED AREAS OF SHOWERS AND
IMPROVEMENT ON WEDNESDAY MAY VARY.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

UTC 1HRLY       18   19   20   21   22   23   00   01   02   03   04   05
EST 1HRLY       13   14   15   16   17   18   19   20   21   22   23   00
CRW CONSISTENCY  L    M    M    H    M    M    L    M    M    M    M    M
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  H    H    H    H    L    M    M    L    L    L    L    L
EKN CONSISTENCY  H    H    M    M    M    L    M    L    L    L    M    M
PKB CONSISTENCY  H    L    M    M    M    H    M    M    M    M    M    H
CKB CONSISTENCY  L    M    M    M    M    M    H    M    M    M    M    M

AFTER 18Z WEDNESDAY...
IFR STILL POSSIBLE IN MOUNTAIN RAIN AND SNOW SHOWERS.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...JSH/RPY/30
NEAR TERM...JMV
SHORT TERM...RPY
LONG TERM...JSH
AVIATION...JMV











AREA FORECAST DISCUSSION

NWS BROWNSVILLE TX

 ISSUED BY NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1116 AM CST TUE NOV 29 2011


.AVIATION...
VFR CONDITIONS WILL CONTINUE THE NEXT 24 HOURS. WEAK FRONT IS
PUSHING THROUGH SOUTH TEXAS WITH WINDS SHIFTING TO THE NORTH LESS
THAN 10 MPH. HRL AND BRO WILL SEE A BRIEF NORTH WIND QUICKLY
VEERING TO THE NORTHEAST BY LATE AFTERNOON. A WEAK GRADIENT WILL
REMAIN TOMORROW WITH LIGHT N AND NE WINDS.

&&

.PREV DISCUSSION... /ISSUED 539 AM CST TUE NOV 29 2011/

DISCUSSION...SEE THE AVIATION SEGMENT BELOW FOR A DISCUSSION OF
THE 12Z TAF PACKAGE. ALSO...SEE THE MARINE SEGMENT BELOW FOR A
MINOR ADJUSTMENT TO THE FIRST PERIOD OF THE COASTAL WATERS
FORECAST.

AVIATION...NO CHANGES WERE NEEDED TO THE EXISTING TAFS. VFR
CONDITIONS WILL CONTINUE TO PREVAIL THROUGH THE NEXT 24 HOURS.
THE PASSAGE OF SURFACE HIGH PRESSURE LOCATED SOUTH OF THE RIO
GRANDE VALLEY TO THE EAST...AS WELL AS THE PASSAGE OF A WEAK COLD
FRONT THROUGH OUR REGION LATER TODAY AND TONIGHT...WILL PRODUCE
MAINLY LIGHT AND VARIABLE WINDS THROUGH THE PERIOD.

MARINE...BUOY 42020 REPORTED SOUTHWEST WINDS AROUND 19 KNOTS WITH
GUSTS TO AROUND 23 KNOTS WITH SEAS SLIGHTLY OVER 4.5 FEET WITH A
PERIOD OF 5 SECONDS AT 05 CST/11 UTC. STRONGER WINDS AND HIGHER
SEAS ARE OCCURRING ALONG THE LOWER TEXAS COAST...A TREND TOTALLY
MISSED BY THE GFS MODEL AND CONFIRMED BY THE RUC. THUS...HAVE
RAISED SMALL CRAFT EXERCISE CAUTION AND INDICATED WINDS OF 15 TO
20 KNOTS FOR THE GULF OF MEXICO WATERS EAST OF PADRE ISLAND FROM
0 TO 60 NAUTICAL MILES OFFSHORE UNTIL NOON TODAY BASED ON THE BUOY
OB AND RUC DATA. RUC SUGGESTS THAT MARINE CONDITIONS WILL IMPROVE
BY THE MID-MORNING TODAY...AT WHICH TIME THE INCOMING SHIFT COULD
LIKELY DISCONTINUE THE SCEC. NO OTHER MARINE FORECAST CHANGES
MADE.

PREV DISCUSSION... /ISSUED 422 AM CST TUE NOV 29 2011/

SHORT TERM /TODAY THROUGH WEDNESDAY/...PLEASANT WEATHER CONDITIONS
WILL DOMINATE THE FIRST 36 HOURS OF THE FORECAST. DRY WEATHER WILL
PREVAIL TODAY AS A MID-LEVEL NORTHWEST-TO-SOUTHEAST FLOW DOMINATES
OVERHEAD...WHILE WARMER TEMPERATURES DEVELOP COURTESY OF A FLOW FROM
THE SOUTH AND SOUTHWEST AT THE SURFACE. ALTHOUGH A WEAK COLD FRONT
WILL PUSH THROUGH DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY LATER
TODAY AND TONIGHT...COURTESY OF SURFACE HIGH PRESSURE BUILDING SOUTH
AND EAST THROUGH THE LONE STAR STATE...NO RAINFALL IS EXPECTED DUE
TO DRY ATMOSPHERIC CONDITIONS CAUSED BY PRECIPITABLE WATER AMOUNTS
UNABLE TO RECOVER FROM THE RECENT STRONG COLD FRONT. COOL AND DRY
WEATHER IS EXPECTED TONIGHT...WITH DRY WEATHER CONTINUING TOMORROW
ALONG WITH NEAR NORMAL TEMPERATURES...COURTESY OF THE COLD FRONTAL
PASSAGE LATER TODAY AND TONIGHT.

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...THE LONGER RANGE
MODEL GUIDANCE CONTINUES TO ADVERTISE A STRONG MID LEVEL SHORT
WAVE DIVING SOUTH ACROSS THE WEST COAST WED AND THURS. THIS SHORT
WAVE CUTS OFF AND SLOWS DOWN CONSIDERABLY OVER THE DESERT SW LATE
THURS AND FRI. THIS FEATURE THEN OPENS UP AS A MORE PROGRESSIVE
SHORT WAVE FRI NIGHT INTO SAT MOVING INTO THE CENTRAL MISS RIVER
VALLEY SUN. FAIRLY DEEP MOISTURE VALUES POOL AHEAD OF THIS FEATURE
OVER THE SW STATES AND THE NORTHERN HALF OF TX. MEANWHILE DEEP
SOUTH TX WILL REMAIN ON THE SOUTHERN FRINGES OF THIS DEEPER
MOISTURE FIELD AND THE STRONGER MID LEVEL DYNAMICS ASSOCIATED WITH
THE CLOSED LOW/TROUGH. WILL MAINTAIN THE MENTION OF 20 TO 30 %
POPS WITH THE APPROACH AND PASSAGE OF THE COLD FRONT ASSOCIATED
WITH THIS MID LEVEL FEATURE PROVIDING THE BEST SURFACE
CONVERGENCE.

THE GFS AND THE ECMWF CONTINUE TO HAVE SOME TIMING DIFFERENCES
WITH THE HANDLING OF THIS FEATURE. THE GFS HAS A LITTLE FASTER
MOVEMENT OF MID LEVEL TROUGH/CLOSED LOW VERSUS THE ECWMF. THESE
TIMING DIFFERENCES EXTEND ON DOWN TO THE SURFACE WITH THE COLD
FRONT ASSOCIATED WITH THIS SYSTEM MOVING THROUGH FASTER IN THE GFS
SOLUTION VERSUS THE SLOWER ECMWF. THE RUN TO RUN CONSISTENCY WITH
THE GFS MEX MOS IS ABOVE AVERAGE AND WILL GO WITH THE GFS SOLUTION
WHICH IS A LITTLE MORE REALISTIC VERSUS THE ECMWF OUTPUT.

MARINE...TODAY THROUGH WEDNESDAY...A WEAK COLD FRONT WILL PASS
THROUGH THE LOWER TEXAS COAST LATER TODAY AND TONIGHT...BUT NO MAJOR
CHANGES IN WINDS AND SEAS ARE EXPECTED IN THE WAKE OF THE FRONT.
OVERALL...LIGHT TO MODERATE WINDS AND LOW TO MODERATE SEAS WILL
PREVAIL FOR THE ADJACENT COASTAL WATERS OF DEEP SOUTH TEXAS TODAY
THROUGH WEDNESDAY.

WEDNESDAY NIGHT THROUGH SATURDAY...THE FORMATION OF THE CLOSED
MID LEVEL LOW TO THE WEST OF TX WILL RESULT IN A MODERATE TO
STRONG PGF ALONG THE LOWER TX COASTLINE. AS A RESULT EXPECT THE SE
SURFACE FLOW TO INCREASE PUSHING ON UP INTO SCEC/SCA CRIT AFTER
WED.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL MMM MMM MMM MMM / MMM MMM MMM MMM
BROWNSVILLE         MMM MMM MMM MMM / MMM MMM MMM MMM
HARLINGEN           MMM MMM MMM MMM / MMM MMM MMM MMM
MCALLEN             MMM MMM MMM MMM / MMM MMM MMM MMM
RIO GRANDE CITY     MMM MMM MMM MMM / MMM MMM MMM MMM
SOUTH PADRE ISLAND  MMM MMM MMM MMM / MMM MMM MMM MMM

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$

THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE

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