Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 11/24/11
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
616 PM EST WED NOV 23 2011
.SYNOPSIS...
A HIGH PRESSURE SYSTEM OVER THE TENNESSEE VALLEY THIS EVENING WILL
BUILD INTO THE REGION AND DOMINATE OUR WEATHER THROUGH THE
WEEKEND. A COLD FRONT, APPROACHING FROM THE WEST, WILL MOVE SLOWLY
ACROSS OUR REGION SUNDAY NIGHT AND MONDAY. LOW PRESSURE MAY
DEVELOP ON THE FRONT ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY
NORTH MONDAY NIGHT INTO TUESDAY NIGHT. ANOTHER FRONTAL SYSTEM,
WITH A REINFORCING SHOT OF COLD AIR, WILL APPROACH FROM THE
NORTHWEST WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
THE LATEST SHORT TERM UPDATE WAS MAINLY TO LOWER CURRENT TEMPS AS
THEY ARE FALLING FASTER, BUT CONVERSELY CLOUDS ARE LINGERING
SLIGHTLY LONGER. THE LATEST HRRR AND WRF-NMM SEEM TO HAVE A PRETTY
GOOD HANDLE ON ANY RESIDUAL SHOWERS ASSOCIATED WITH THE SHARPENING
TROF OVER THE SERN PART OF OUR CWA.
HIGH PRESSURE BACK OVER THE TENNESSEE VALLEY WILL CONTINUE TO
WORKS ITS WAY TOWARDS OUR REGION TONIGHT.
A TIGHTENING PRESSURE GRADIENT AND STRONG COLD AIR ADVECTION WILL
HELP TO KEEP THE STRONGER WIND GUSTS IN THE FORECAST THROUGH AT
LEAST 03Z. LATEST VAD WIND PROFILE AND ACARS SOUNDINGS ARE SHOWING
THAT THE WRF-NMM IS OVERFORECASTING THE CORE OF THE BLO 850MB CAA
JET BY ABOUT 10 KNOTS. WE START TO DECOUPLE UNDER CLEARING SKIES
AND COMPLETELY LOSE THE GUSTS. TEMPERATURES WILL BE AT LEAST 10
TO 15 DEGREES COLDER THAN TUESDAY NIGHT WITH THE COLD AIR
ADVECTION AND DECREASING COLD COVER.
THANKSGIVING MORNING LOOKS TO BE A PLEASANT ONE WITH TEMPERATURES IN
THE UPPER 30S AND A BRISK WESTERLY WIND AROUND 10 KNOTS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
HIGH PRESSURE CONTINUES TO MOVE INTO OUR REGION TOMORROW HELPING US
TO MAINTAIN THE NORTHWESTERLY WINDS AND CLEAR SKIES. THE PRESSURE
GRADIENT WILL BEGIN TO SLACKEN EVEN MORE TOMORROW AND DEEP MIXING
APPEARS OUT THE QUESTION SO GUSTS SHOULD NOT BE AN ISSUE...AROUND 15
KNOTS OR LESS. IT IS CERTAINLY GOING TO BE ONE GORGEOUS
THANKSGIVING DAY.
HAPPY THANKSGIVING!!!!
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
A LARGE HIGH PRESSURE SYSTEM, CENTERED JUST TO OUR SOUTH, WILL
MOVE SLOWLY EAST TO A POSITION JUST OFF THE NORTH CAROLINA COAST
ON SATURDAY. THIS SYSTEM WILL SUPPLY US WITH FAIR AND RELATIVELY
MILD WEATHER THROUGH THE WEEKEND. WILL SEE PLENTY OF SUNSHINE
FRIDAY AND SATURDAY. CLOUDS WILL BEGIN TO INCREASE SUNDAY AS THE
HIGH MOVES OFF TO THE EAST AND A COLD FRONT APPROACHES FROM THE
WEST. THERE COULD BE A FEW LIGHT SHOWERS SPREADING INTO OUR
NORTHWEST SECTIONS LATE IN THE DAY. DAYTIME HIGHS FRIDAY THROUGH
SUNDAY WILL BE IN THE MID 50S TO MID 60S. OVERNIGHT LOWS WILL BE
MAINLY IN THE 30S THURSDAY NIGHT AND IN THE MID 30S TO MID 40S
FRIDAY NIGHT AND SATURDAY NIGHT. RAIN IS LIKELY SUNDAY NIGHT AND
MONDAY AS THE COLD FRONT CROSSES THE REGION. LOW PRESSURE WILL
THEN DEVELOP ON THE FRONT ALONG THE MID ATLANTIC COAST AND MOVE
NORTH. THIS COULD MORE RAIN TO OUR AREA MONDAY NIGHT INTO TUESDAY
NIGHT. WITH CLOUDS AND RAIN, HIGH TEMPERATURES MONDAY AND TUESDAY
WILL BE SLIGHTLY LOWER THAN OVER THE WEEKEND, WITH READINGS IN
THE UPPER 40S AND 50S. BY WEDNESDAY, ANOTHER FRONT WILL BE
APPROACHING FROM THE NORTHWEST, AS AN UPPER TROUGH MOVES EAST
FROM THE GREAT LAKES. THIS FRONT WILL USHER IN A REINFORCING
SHOT OF COLD AIR BUT WILL BE MOISTURE STARVED. LOOKS LIKE THE
MOST WE COULD GET WOULD BE SCATTERED SHOWERS. HIGH TEMPERATURES
WEDNESDAY WILL BE IN THE 40S TO LOWER 50S.
&&
.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE SOON TO BE ISSUED 00Z TAFS WILL FEATURE IMPROVING CONDITIONS
WITH ANY MVFR CIGS DISAPPEARING AS THE EVENING PROGRESSES. ANY
LEFTOVER SHOWERS EARLY SE TERMINALS SHOULD NOT PRODUCE VSBY
RESTRICTIONS. THE FORECAST MODELS ARE CLEARING SKIES A BIT TOO
HASTILY BASED ON UPWIND FCST SOUNDINGS AND OBSERVATIONS. SO WE
DID LINGER A MAINLY VFR STRATOCU CIG SLIGHTLY LONGER. NORTH TO
NORTHWEST WINDS WILL BE GUSTY THIS EVENING, BUT BASED ON ACAR
SOUNDINGS SHOULD MAINLY REMAIN BELOW 30KTS. AS THE HIGH NEARS,
CLEAR SKIES WILL PREVAIL AND WE SHOULD LOSE THE WIND GUSTS
OVERNIGHT. THE PREVAILING FCST WIND SPEEDS MAY BE A BIT TOO HIGH
FOR THE EARLY MORNING HOURS, THESE ARE WEIGHED TOWARD THE START OF
THE OVERNIGHT FCST PERIOD GROUP.
VERY DRY AIR MASS ON THURSDAY, THANKSGIVING DAY, AND WE ARE NOT
EXPECTING ANY CLOUDS TO FORM. WINDS WILL SLOWLY BACK TO THE WEST
AND THERE IS THE SUGGESTION OF SOME MID TEEN WIND GUSTS POSSIBLE
DURING THE AFTERNOON. BUT THERE WILL BE A QUICK DECOUPLING OF THE
WINDS ONCE THE SUN SETS.
OUTLOOK...
THE HIGH PRESSURE SYSTEM TO OUR SOUTH WILL CONTINUE TO PROVIDE US
WITH GOOD VFR FLYING CONDITIONS WELL INTO SUNDAY. A COLD FRONT
MOVING IN FROM THE WEST AND A LOW DEVELOPING ON THIS FRONT, ONCE
IT MOVES JUST OFF TO OUR EAST, WILL BRING OUR NEXT ROUND OF
INCLEMENT WEATHER SUNDAY NIGHT INTO THE MIDDLE OF NEXT WEEK.
LOWER CIGS/VSBYS IN RAIN AND FOG CAN BE EXPECTED FOR MUCH OF
THAT TIME PERIOD.
&&
.MARINE...
WITH THE COLD FRONT NOW TO OUR EAST AND HIGH PRESSURE TRYING TO NOSE
IN FROM THE WEST THE SURFACE PRESSURE GRADIENT WILL REALLY TIGHTEN
UP TONIGHT. NORTHERLY TO NORTHWESTERLY WINDS WILL BEGIN TO REALLY
HOWL WITH MULTIPLE HOURS OF GALE FORCE GUSTS EXPECTED TONIGHT. SEAS
WILL ALSO REMAIN QUITE ELEVATED TONIGHT IN THE WAKE OF THE STRONGER
NNW FLOW RUNNING AROUND 6 FEET.
THE GALE WARNING IS STILL IN AFFECT FOR ALL OUR COASTAL ZONES
THROUGH 09Z...THAT REMAINS UNCHANGED. AFTER THAT TIME PERIOD THE
GUSTS DROP INTO SMALL CRAFT RANGE FOR A FEW MORE HOURS FOLLOWED BY
SMALL CRAFT FOR HAZARDOUS SEAS BEING A POSSIBILITY.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR WATERS
THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST, A COLD FRONT
WILL APPROACH FROM THE WEST. THE PRESSURE GRADIENT WILL TIGHTEN
BETWEEN THESE TWO SYSTEMS. THIS WILL MEAN INCLEMENT WEATHER WITH
INCREASING S TO SE WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY.
LOW PRESSURE IS THEN FORECAST TO DEVELOP ON THE FRONT ONCE IT MOVES
OFF THE EAST COAST. DEPENDING ON THE TIMING AND LOCATION OF THE LOW,
ADVISORY OR GALE CONDITIONS COULD OCCUR IN THE SUNDAY NIGHT TO MID
WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
THE CONSENSUS OF THE LATEST GUIDANCE PRODUCTS (STEVENS, MDL AND
THE BOFS FAMILY) GIVES TIDAL DEPARTURES THAT WOULD JUST TOUCH
MINOR TIDAL FLOODING LEVELS ALONG THE OCEANFRONT. MOST OF THE
FORECAST DEPARTURES ARE LESS THAN HALF A FOOT AS THE BULK OF THE
TIDE ISSUES HAVE TO DO WITH THE ASTRONOMICAL SPRING TIDE
ASSOCIATED WITH THE NEW MOON. BECAUSE OVERALL WAVE ACTION IS NOT
EXPECTED TO BE UNUSUALLY HIGH AND NO RAIN IS EXPECTED, WE HAVE
DECIDED TO ISSUE A COASTAL FLOOD STATEMENT VS AN ADVISORY. THE
FORECAST NORTH WINDS ARE CAUSING SOME OF THE HIGHER GUIDANCE TIDAL
DEPARTURES AT SANDY HOOK AND LEWES.
FARTHER UP IN DELAWARE BAY AND THE TIDAL DELAWARE RIVER, THE WIND
DIRECTION SHOULD ASSIST. OVERALL TIDAL DEPARTURES HAVE TO BE
GREATER THAN AT THE SHORE, GENERALLY AROUND THREE-QUARTERS OF A
FOOT. THE ONE CAVEAT THAT WE WILL HAVE TO WATCH IS THE BELOW FLOOD
STAGE RIVER CREST NOW WORKING ITS WAY DOWN THE DELAWARE RIVER.
ALONG CHESAPEAKE BAY, NO TIDAL PROBLEMS ARE BEING REPORTED WITH
THE CURRENT HIGH TIDE CYCLE AND DEPARTURES ARE ALREADY DECREASING.
THE OVERALL NORTHWEST TO NORTH WINDS SHOULD HELP CONTINUE DRAIN IT
AND LOWER DEPARTURES INTO THURSDAY MORNING.
ASTRONOMICAL HIGH TIDES WITH THE CURRENT NEW MOON SPRING TIDE
CYCLE WILL PEAK ON FRIDAY MORNING. CURRENT EXPECTATIONS ARE FOR
THE WIND DIRECTION TO BE LESS FAVORABLE AND BY THEN THE DELAWARE
RIVER FRESH WATER CREST WILL ALSO BE THROUGH.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...GALE WARNING UNTIL 4 AM EST THURSDAY FOR ANZ430-431-450>455.
&&
$$
SYNOPSIS...RPW
NEAR TERM...GIGI/HEAVENER
SHORT TERM...HEAVENER
LONG TERM...RPW
AVIATION...GIGI/RPW
MARINE...HEAVENER/RPW
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
900 PM EST Wed Nov 23 2011
.SYNOPSIS...
01Z water vapor and H4 RUC analysis show the main upper level
trough axis that impacted the forecast area the past 36 hours is now
exiting off the Atlantic seaboard to our east. One final impulse is
sliding down the backside of this trough...however the atmospheric
column is now far to dry for this energy to pose any threat. KTLH
sounding from this evening shows a PW values all the way down to
0.4", and a very dry profile above 900mb. With this profile, not a
cloud to be found over our land zones, and this will hold through
the overnight. With the drier atmosphere and clear skies, temps will
be cool overnight, reaching the 40s at most inland locations. The
current grids show the normally colder spots reaching the lower 40s
by sunrise. This seems like it would be the coldest scenario, as the
gradient never really relaxes. Expecting to see winds occasionally
bump up to 4 to 5 knots, even for the more sheltered area, and would
not be surprised if low temps end up above what is currently
forecast.
A dry atmosphere and surface high pressure will provide a pleasant
Thanksgiving day across the Southeast U.S. Forecast will show plenty
of sunshine and temperatures reaching the upper 60s/lower 70s during
the afternoon hours. Enjoy!
&&
.MARINE...
The gradient will tighten overnight across the northeast Gulf of
Mexico as strong high pressure passes well to our north. Winds will
shift to the north and eventually northeast by early Thursday
morning and increase to around advisory levels. Winds will diminish
below advisory levels by around midday Thursday...however winds will
continue to reach cautionary levels at times through at least
Thursday night.
&&
.Aviation (through 00Z Friday)...
Skies have cleared across the entire region in the wake of the cold
front. VFR conditions are expected to prevail through the TAF
period. Winds will veer around from north to northeast by the
morning hours and will become gusty at 10 to 15 knots during the
later morning and afternoon hours.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 43 72 38 72 49 / 0 0 0 0 0
Panama City 48 69 45 68 55 / 0 0 0 0 0
Dothan 44 70 39 71 48 / 0 0 0 0 10
Albany 43 69 39 72 47 / 0 0 0 0 0
Valdosta 46 71 40 74 49 / 0 0 0 0 0
Cross City 45 72 39 74 50 / 0 0 0 0 0
Apalachicola 51 70 47 69 57 / 0 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
MROCZKA/CAMP
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
8 PM EST WED NOV 23 2011
.DISCUSSION...
CURRENT ROUND OF METARS...BUOY REPORTS AND SURFACE ANALYSIS PLACED A
WEAK COLD FRONT STRETCHING FROM NORTHERN BREVARD COUNTY TO THE TAMPA
BAY AREA WITH HIGH PRESSURE BUILDING ACROSS NORTH FLORIDA AND MOVING
DOWN THE PENINSULA. UPSTREAM DEW POINTS WERE STILL IN THE LOW 60S
FROM AROUND SAINT AUGUSTINE TO GAINESVILLE AND CROSS CITY BUT TO THE
NORTH THE DEW POINTS WERE IN THE LOW AND MID 50S.
THE FRONT WILL CONTINUE TO WEAKEN AS IT MOVES DOWN THE PENINSULA
OVERNIGHT. LATEST RUC 500MB HEIGHT ANALYSIS SHOWED THE UPPER TROUGH
AXIS OVER THE EASTERN GULF WITH NORTHWEST FLOW OVER THE SOUTHEAST.
WILL HAVE TO DEAL WITH BRIEF PERIODS OF LOW CLOUDS FIRST PART OF THE
NIGHT AS THE COOLER AIR MASS RUNS OVER THE STILL RELATIVELY MOIST
AND WARMER AIR BELOW IT BUT AFTER MIDNIGHT WILL SEE CLEAR SKIES
EVOLVING NORTH TO SOUTH.
EVENING UPDATE MAKES CHANGES TO SEVERAL GRIDS...SKIES...WINDS AND
TEMPERATURE GRIDS TO SHOW A SLIGHTLY SLOWER FRONTAL MOVEMENT.
WINDS SHOULD START TO INCREASE TOWARD SUNRISE AS THE HIGH PRESSURE
BUILDS OVER CENTRAL FLORIDA.
PREVIOUS DISCUSSIONS
THU...BREEZY (WINDY NEAR THE COAST?) AND COOLER WX ON TAP AS LARGE
AREA OF HIGH PRESSURE OVER THE SE BUILDS TO THE MID ATLC STATES.
MAY SEE SOME MARINE SC PUSH ONSHORE COASTAL AREAS BY AFTERNOON
BUT BY AND LARGE SKIES SHOULD BE SUNNY-MOSUNNY WITH MAXES IN THE
70-75F RANGE.
THU NIGHT...THE TAIL END OF A MID-LEVEL TROUGH WILL SWEEP DOWN THE
EAST FLORIDA COAST OVERNIGHT. AT THE SURFACE HIGH PRESSURE OVER THE
SOUTHEAST U.S. WILL STRENGTHEN ITS GRIP ACROSS THE FLORIDA PENINSULA
WITH WINDS OUT OF THE NORTHEAST. CONDITIONS WILL REMAIN DRY AS
MOISTURE WILL HAVE BEEN SCOURED OUT WITH THE MOST RECENT FRONTAL
PASSAGE...BUT WILL HAVE TO WATCH FOR POSSIBLE MARINE STRATOCUMULUS
CLOUDS ALONG THE COAST. MIN TEMPS IN THE L/M50S ALONG AND N OF THE
I-4 CORRIDOR AND THROUGH THE INTERIOR (NEAR CLIMO) WITH L/M60S ALONG
THE SPACE AND TREASURE COASTS (ARND 5F ABV CLIMO).
FRI-FRI NIGHT...AS THE PREVIOUSLY MENTIONED UPPER TROUGH MOVES AWAY
FROM THE PENINSULA...SHORTWAVE RIDGING WILL AMPLIFY AND SLIDE
EASTWARD ACROSS THE PENINSULA AS ANOTHER UPPER TROUGH DIGS ACROSS
THE CENTRAL CONUS. THE SURFACE RIDGE LOCATED TO THE NORTH WILL HOLD
TIGHT THOUGH WINDS WILL VEER TO EASTERLY. WILL HAVE TO BE MINDFUL OF
POSSIBLE MARINE STRATOCUMULUS CLOUDS OVER THE COASTAL WATERS AND
PERHAPS NEAR THE COAST AS MOISTURE GETS TRAPPED BENEATH A RATHER
STOUT INVERSION LOCATED AT AROUND 850 MB. WILL KEEP CONDITIONS DRY
THROUGH THIS PERIOD FOR NOW. MAX TEMPS IN THE M/U70S (NEAR
CLIMO)...MIN TEMPS L/M60S (5-7F ABV CLIMO)...EXCEPT UPPER 50S LAKE
COUNTY.
SAT-TUE...(PREVIOUS EXTENDED DISCUSSION)...EXTENDED GUIDANCE SHOWING
SOME DISPARITY WRT TO THE NEXT FL FROPA. THE HI AMP FRONTAL TROF
WILL BE FED BY A VERY STRONG H25 JET MAX. BOTH GFS/ECMWF MODELS
INDICATE THE SYSTEM BCMG A FULL LAT TROF BY DAYBREAK SUN...THOUGH
THE GFS IS A BIT FASTER WITH THE MID LVL TROF AXIS. ALSO...BOTH
INDICATE A SECONDARY LOW WITH NEGATIVELY TILTED MID LVL TROF DVLPG
OVER THE DEEP SOUTH BY DAYBREAK MON...THOUGH AGAIN GFS HAS A FASTER
SOLUTION AS WELL AS A DEEPER SFC LOW. NOT SURPRISINGLY...GFS PUSHES
ITS FRONTAL MOISTURE BAND THRU THE FL PENINSULA A GOOD 24HRS AHEAD
OF THE ECMWF.
THE JET PATTERN OVER THE N PAC IS QUITE STRONG AND EXTENSIVE WITH
100KT ISOTACH NEARLY SPANNING ITS LENGTH BTWN THE 30TH AND 40TH
PARALLEL. THIS SHOULD FAVOR A MORE PROGRESSIVE WX PATTERN THRU THE
FIRST PART OF NEXT WEEK. TOWARD THIS END...WILL LEAN TOWARD THE
FASTER GFS SOLUTION AND FOCUS PRECIP SUN INTO MON. RIDGING OVER THE
ATLC WOULD TEND TO MAKE THE FROPA A FAIRLY SLOW ONE WITH POPS
BEGINNING BY MIDDAY SUN AND CONTINUING THRU MIDDAY MON.
TEMPS ABV CLIMO THRU THE WEEKEND WITH MAXES IN THE U70S/L80S...MINS
IN THE L/M60S. MEX NUMERICAL GUIDANCE HAS TRENDED COLDER BEHIND THE
FRONT WITH MIN TEMPS N OF I-4 FALLING INTO THE L/M50S MON MORNING
AND INTO THE L/M40S TUE MORNING...BUT HOLDING IN THE L/M60S ALONG
THE TREASURE COAST MON MORNING BEFORE DROPPING INTO THE L50S TUE
MORNING. MAX TEMPS IN THE M60/L70S BOTH DAYS.
&&
.AVIATION...PREVAILING VFR. TEMPO MVFR CEILINGS THROUGH MIDNIGHT
THEN SKC.
&&
.MARINE...
BUOYS RECORDING WEST NORTHWEST WINDS AROUND 15 KNOTS AND 2 TO 3 FOOT
SEAS OUT TO 20NM AND ONLY 3 FEET AT BUOY 010. WINDS WILL SHIFT TO
THE NORTH AND INCREASE TOWARD SUNRISE AS HIGH PRESSURE BUILDS DOWN
THE COASTAL WATERS. SEAS WILL INCREASE AND BECOME CHOPPY...
ESPECIALLY IN THE GULF STREAM WHERE NORTHERLY WINDS PUSH AS THE
NORTHWARD FLOWING STEAM OF WATER.
LATEST GFS WINDS AND SWAN WAVE GUIDANCE BRING PRETTY SOLID SCA CONDS
FROM N-S INTO THE 0-20NM LEGS LATE TONIGHT/EARLY THU MORNING...AND
AS SUCH HAVE EXPANDED THE SCA TO INCLUDE THE ENTIRE MAOR.
THU NIGHT...INITIAL NNE WINDS AROUND 20+ KTS VEER TO NE/ENE
OVERNIGHT AND DECREASE SLIGHTLY TO 15-20/20KTS. SMALL CRAFT ADVISORY
CONDITIONS CONTINUING. A FRESH NORTHEAST LONG PERIOD SWELL WILL
PLAGUE THE COASTAL WATERS DRIVING SEAS OUT TO 20 NM OFF THE COAST
AND 7-9 FT 20-60NM OFFSHORE.
FRI-FRI NIGHT...HIGH PRESSURE OVER THE SOUTHEAST WILL REMAIN IN
PLACE KEEPING WINDS ONSHORE...ENE/NE WINDS THROUGH THIS TIME WITH
SPEEDS AVERAGING 15-20/20 KTS. SEAS REMAIN STUBBORN AND SLOW TO
SUBSIDE WITH 5-8 FT SEAS AWAY FROM THE COAST AND ACROSS THE GULF
STREAM...SLIGHTLY LOWER HEIGHTS CLOSER TOWARD THE COAST.
SAT-MON...E WINDS WILL BEGIN TO VEER LATE SAT NIGHT TO ESE/SE WITH
SSE/S WINDS INTO MON AHEAD OF AN APPROACHING FRONTAL BOUNDARY. IF
THIS FRONT PICKS UP STEAM WINDS COULD EASILY VEER MORE SW OR W
DURING THE DAY ON MON. THE SURFACE HIGH PRESSURE RIDGE WILL WEAKEN
DURING THIS TIME AND GET PUSHED FURTHER OUT INTO THE WESTERN ATLC.
THE TIGHTENING PRESSURE GRADIENT MAY AGAIN INCREASE WIND SPEEDS LATE
SUN INTO MON AHEAD OF THE NEXT SYSTEM.
WHILE SOME SHOWER ACTIVITY MAY BEGIN TO INCREASE THROUGH THE LATTER
HALF OF THE WEEKEND AS MOISTURE PROFILES STRENGTHEN...THE BIGGEST
THREAT FROM HEAVIER SHOWERS OR AN ISOLATED LIGHTNING STORM MAY BE
LATE SUN NIGHT OR INTO MON AS THESE CELLS WOULD PUSH OFF OF THE
COAST. AS OF THIS WRITING...TIMING OF THIS SYSTEM NEEDS TO BE IRONED
OUT FOR FURTHER CONFIDENCE.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FROM 5 AM THURSDAY TO 4 AM FRIDAY FROM
FLAGLER BEACH TO JUPITER INLET OUT 20 NM.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 4 PM SATURDAY
FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM
OFFSHORE.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 4 PM SATURDAY
FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET 20 TO 60 NM
OFFSHORE.
SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 4 PM SATURDAY FROM
SEBASTIAN INLET TO JUPITER INLET 20 TO 60 NM OFFSHORE.
&&
$$
UPDATES/AVIATION...WIMMER
IMPACT WX.....PENDERGRAST
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
933 AM EST TUE NOV 22 2011
.UPDATE...PATCHY DENSE FOG/STRATUS NOTED AT THIS TIME AND
VISIBLE IMAGERY SHOWS MULTILAYERED CLOUDS OVER MOST PORTIONS OF THE
REGION. MODEL THICKNESS FIELDS WHEN COMBINED WITH CLOUDINESS
SUGGEST A WARM FRONT OVER N CENTRAL FL AND RADAR HAS BEEN SHOWING A
FEW LIGHT SHOWERS/SPRINKLES SE OF A LINE FROM ST AUGUSTINE TO
PALATKA NEAR THIS FRONT. 12Z JAX SOUNDING SHOWS PWAT OF 1.1 INCHES
MOST OF IT BELOW 650 MB AND SIGNIFICANT SUBSIDENCE INVERSION ABOVE
THAT. LLVL FLOW PER SOUNDING IS GENERALLY S TO SW...WHILE CURRENT SFC
DATA SHOWS VERY WEAK SE E TO SE WINDS.
FOR REST OF TODAY...Q-VECTOR CONVERGENCE ALONG WITH SURGE OF DEEPER
MOISTURE AND THE WARM FRONT WILL ALLOW FOR ISOLD TO SCT SHOWER
ACTIVITY (MAINLY AFTN HRS)...MAINLY OVER NE FL. RUC MODEL SOUNDING
SHOWS ENOUGH INSTABILITY (CAPE 1200 J/KG AND LI -3) IN THE AFTERNOON
TO SUPPORT A THUNDERSTORM OVER NE FL. SREF OUTPUT ALSO INDICATING AT
LEAST 20-30% CHANCE OF A THUNDERSTORM BY AFTN HRS. THE SLY FLOW WILL
ALSO AID IN TEMPS REACHING THE UPPER 70S AND LOWER 80S WITH PARTLY
TO MOSTLY CLOUDY SKIES.
&&
.AVIATION...CONDS RANGE FROM LIFR TO VFR AT THIS TIME. GNV STILL
DOWN AT 1MI BKN003 AND SHOULD IMPROVE WITHIN NEXT HR BUT AFT THAT
STILL MVFR EXPECTED AT TIMES THROUGH NOON. IN THE AFTN/EARLY
EVENING...VFR EXPECTED TO PREVAIL THOUGH ANTICIPATE SCT-LCL
BKN030-045. ANTICIPATE MVFR CIG/VSBY DEVELOPING 03Z-06Z WITH
COMBINATION OF MVFR/IFR POSSIBLE DUE TO CIGS AFT 06Z.
&&
.MARINE...ESE FLOW IS 5-10 KT AND SEAS GENERALLY 2-4 FT. ANTICIPATE
WINDS COMING AROUND TO SE AND INCREASING DURING THE DAY AS PRES
GRADIENT INCREASES AHEAD OF APPROACHING FRONT. WILL REMOVE FOG FROM
FCST AND ONLY MINOR ADJUSTMENTS TO WINDS/SEAS.
RIP CURRENTS: MODERATE RISK TODAY DUE TO LONG PERIOD SWELL ~10
SECONDS FROM THE E TO SE.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 81 61 75 45 / 20 60 70 0
SSI 76 64 75 51 / 20 30 60 0
JAX 81 61 79 47 / 30 30 50 10
SGJ 78 63 80 55 / 30 30 50 20
GNV 82 60 81 48 / 30 20 60 20
OCF 83 61 81 49 / 30 30 60 20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...SMALL CRAFT ADVISORY FROM 4 AM TO 11 AM EST WEDNESDAY FOR
ALTAMAHA SOUND GA TO FERNANDINA BEACH FL 20 NM TO 60 NM
OFFSHORE.
&&
$$
SHASHY/KEEGAN
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
953 PM EST WED NOV 23 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE WEST TONIGHT AND
PERSIST THROUGH THE WEEKEND. ANOTHER COLD FRONT WILL AFFECT THE
REGION EARLY NEXT WEEK...FOLLOWED BY ANOTHER HIGH PRESSURE SYSTEM.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
NO MAJOR CHANGES ARE NEEDED TO THE GRIDS AND TEXT PRODUCTS FOR THE
LATE EVENING UPDATE. A PRONOUNCED WIND SURGE IS MOVING STEADILY
SOUTH AND WILL CLEAR THE SOUTHERN PARTS OF THE FORECAST AREA
BY MIDNIGHT. BOTH TEMPERATURES AND DEWPOINTS ARE FALLING QUICKLY
IN ITS WAKE. LOWS FROM THE LOWER 40S WELL INLAND TO UPPER 40S AT
THE BEACHES SEEM QUITE REASONABLE.
LAKE WINDS...WINDS AT BOTH PINEVILLE AND PINOPOLIS INDICATE WINDS
ARE SOLIDLY WITHIN LAKE WIND ADVISORY THRESHOLDS. ALTHOUGH WINDS
SHOULD PEAK WITHIN THE NEXT FEW HOURS...IT WILL TAKE SOMETIME FOR
SPEEDS TO DIMINISH. A LAKE WIND ADVISORY WILL CONTINUE FOR LAKE
MOULTRIE UNTIL 6 AM.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
AN UPPER LEVEL TROUGH WILL CONTINUE TO PUSH OFFSHORE ON THURSDAY
AS RIDGING BUILDS INTO THE REGION FROM THE WEST. THE UPPER LEVEL
RIDGE WILL THEN PREVAIL OVER THE SOUTHEASTERN STATES THROUGH
SATURDAY. AT THE SURFACE...EXPANSIVE HIGH PRESSURE WILL PERSIST
ACROSS THE MID-ATLANTIC REGION AND SOUTHEAST STATES THROUGH
FRIDAY...THEN BEGIN TO SHIFT OFFSHORE ON SATURDAY.
STRONG SUBSIDENCE AND A LACK OF ANY SIGNIFICANT MOISTURE WILL RESULT
IN RAIN FREE CONDITIONS AND MAINLY CLEAR SKIES INTO FRIDAY.
THEN...AS THE LOW LEVEL FLOW BECOMES MORE ONSHORE SOUTH OF THE
SURFACE HIGH...AN INCREASE IN CLOUD COVER IS EXPECTED INTO THE START
OF THE WEEKEND...ESPECIALLY ACROSS SOUTHEAST GEORGIA. TEMPERATURES
WILL BE SLIGHTLY BELOW NORMAL ON THURSDAY...MODERATE TO NEAR NORMAL
ON FRIDAY...THEN BECOME SLIGHTLY ABOVE NORMAL BY SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT SHOWING A BLOCKING
RIDGE DEVELOPING OVER THE WESTERN ATLANTIC BY THE END OF THE
WEEKEND...RESULTING IN THE DEVELOPMENT OF A HIGHLY AMPLIFIED UPPER
LEVEL TROUGH NEAR THE MISSISSIPPI VALLEY. MODELS THEN SHOW A CLOSED
UPPER LEVEL LOW DEVELOPING SOMEWHERE OVER THE SOUTHEAST STATES EARLY
IN THE WEEK...BUT THERE IS SIGNIFICANT SPREAD IN THE MODELS WITH
RESPECT TO THE LOCATION AND PROGRESSION OF THE UPPER LEVEL
LOW...WITH THE 23/00Z GFS MORE PROGRESSIVE THAN THE 23/00Z ECMWF AND
CANADIAN. THIS LEADS TO A RATHER LOW CONFIDENCE FORECAST...BUT WILL
FAVOR THE GFS SOLUTION WHICH IS IN LINE WITH HPC THINKING. AS A
RESULT...A COLD FRONT IS EXPECTED TO APPROACH FROM THE WEST LATE IN
THE WEEKEND...PUSHING THROUGH THE AREA SUNDAY NIGHT INTO MONDAY AS
THE TROUGH AXIS TAKES ON A NEGATIVE TILT. A GOOD MOISTURE FEED AHEAD
OF THE FRONT SHOULD RESULT IN A SOLID CHANCE OF SHOWERS ACROSS MUCH
OF THE AREA...WITH PERHAPS A FEW STRONG THUNDERSTORMS ACCOMPANYING
THE FRONT ITSELF. DRIER CONDITIONS ARE EXPECTED TUESDAY AND
WEDNESDAY AS THE FRONT SHIFTS OFFSHORE AND THE UPPER LOW LIFTS
NORTHWARD. ABOVE NORMAL TEMPERATURES LATE IN THE WEEKEND WILL FALL
BELOW NORMAL IN WAKE OF THE COLD FRONT.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THE 00Z TAF PERIOD FOR BOTH KCHS
AND KSAV. THE MAIN ISSUE OVERNIGHT WILL BE WHETHER GUSTY CONDITIONS
PERSIST AT KCHS...OR WHETHER SURFACE WINDS WILL DIMINISH BELOW 10
KNOTS RESULTING IN LLWS. UPSTREAM OBS CONTINUE TO GUST NEAR 20
KNOTS...AND THIS IS EXPECTED TO TRANSITION ACROSS KCHS FOR SEVERAL
HOURS INITIALLY THIS EVENING. THEREAFTER...SURFACE WINDS WILL LIKELY
DIMINISH AND WITH MODEL SOUNDINGS SHOWING VEERING 35 KT WINDS
ALOFT...MARGINAL LLWS WOULD THEN PERSIST THROUGH THE REMAINDER OF
THE EVENING. OCCASIONAL GUSTS CAN NOT BE RULED OUT ACROSS KSAV PRIOR
TO 03Z...BUT EXPECT OVERALL WIND SPEEDS AT THE SURFACE TO REMAIN 10
KNOTS OR LESS THROUGH THE OVERNIGHT. THEREFORE...WENT AHEAD AND
INITIALIZED KSAV WITH LLWS THROUGH THURSDAY MORNING.
EXTENDED AVIATION OUTLOOK...SUB-VFR CONDITIONS POSSIBLE SUN/MON IN
SCATTERED SHOWERS AND T-STORMS.
&&
.MARINE...
SMALL CRAFT ADVISORIES CONTINUE FOR ALL MARINE LEGS. BUOY
OBSERVATIONS AND RADAR DATA INDICATE THE INITIAL WIND SURGE
CONTINUES TO WORK SOUTH. A SPECIAL MARINE WARNING HAS BEEN ISSUED
ALONG AND AHEAD OF THE LEADING LEDGE TO COVER GUSTS TO 35-40 KT
FOR LESS THAN 2 HOURS. INCOMING RUC DATA SUGGEST MARGINAL GALES
MAY OCCUR BEHIND THE WIND SURGE FOR SEVERAL MORE HOURS WITH
BOUNDARY LAYER WINDS FORECAST TO BE RIGHT AT 35 KNOTS. MODIS WATER
TEMPERATURE DATA INDICATE SEA SURFACE TEMPERATURES ARE IN THE
UPPER 60S TO LOWER 70S BEYOND 40 NM...SO GALES COULD CERTAINLY
OCCUR IN THE WARMER WATERS WERE MORE VIGOROUS MIXING WILL OCCUR.
HOWEVER...PER COORDINATION WITH WFO JAX...HAVE OPTED TO HOLD WINDS
AT 25-30 KT FOR NOW SINCE THE EVENT LOOKS MARGINAL AND HANDLE
WITH A STRONG SMALL CRAFT ADVISORY. A GALE WARNING MAY STILL BE
NEEDED...BUT CONFIDENCE IS NOT GREATER THAN 80 PERCENT ATTM.
THURSDAY THROUGH MONDAY...IMPROVING CONDITIONS ARE EXPECTED ON
THURSDAY AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE
NORTHWEST. WINDS AND SEAS SHOULD FALL BELOW SMALL CRAFT ADVISORY
CRITERIA FOR ALL NEAR SHORE WATERS BY THE END OF THE DAY
THURSDAY...BUT A FAVORABLE FETCH WILL KEEP SEAS ELEVATED ABOVE
ADVISORY CRITERIA ACROSS THE OUTER GEORGIA WATERS THROUGH FRIDAY
AFTERNOON.
THE AREA OF HIGH PRESSURE WILL PREVAIL OVER THE REGION INTO THE
WEEKEND...WITH A COLD FRONT THEN EXPECTED TO APPROACH FROM THE WEST
LATE IN THE WEEKEND AND PUSH OFFSHORE EARLY NEXT WEEK. ADDITIONAL
SMALL CRAFT ADVISORIES ARE POSSIBLE OVER PORTIONS OF THE WATERS IN
ASSOCIATION WITH THIS FRONT.
&&
.TIDES/COASTAL FLOODING...
GIVEN THE UPCOMING PERIGEAN SPRING TIDES THERE IS A PRETTY GOOD
CHANCE OF EXCEEDING COASTAL FLOOD ADVISORY CRITERIA DURING THE
MORNING HIGH TIDES THURSDAY THROUGH AT LEAST SATURDAY. WITH THE
ASTRONOMICAL PREDICTED VALUES RIGHT AT 7.0 FT IN CHARLESTON HARBOR
THURSDAY THROUGH SATURDAY MORNINGS...ONLY A NEUTRAL OR HIGHER
ANOMALY WILL BE NECESSARY FOR MINOR COASTAL FLOODING. THIS APPEARS
QUITE LIKELY GIVEN THE VEERING WIND PROFILE LATE TONIGHT THROUGH
THURSDAY. LATER SHIFTS MAY NEED TO ISSUE A COASTAL FLOOD ADVISORY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL 6 AM EST THURSDAY FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EST THURSDAY FOR AMZ330-352.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THURSDAY FOR AMZ350.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THURSDAY FOR AMZ354.
SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR AMZ374.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
322 PM EST TUE NOV 22 2011
.SHORT TERM...
TONIGHT THROUGH WEDNESDAY NIGHT...
KIWX RADAR SHOWING LARGE EXPANSE OF MODERATE RAIN...WITH EMBEDDED
HEAVIER BANDS...COVERING THE ENTIRE CWA THIS AFTERNOON. SFC ANALYSIS
INDICATING LOW PRESSURE CENTER HAS MOVED INTO SW INDIANA...WITH
PRESSURE FALL ANALYSIS TAKING LOW ON NE TRACK BETWEEN DAYTON AND
LIMA THIS EVENING. THIS TRACK WOULD BRING 700MB LOW AND ASSOCIATED
DEFORMATION AXIS ACROSS THE AREA AND RESULT IN CONTINUED MODERATE TO
HEAVY RAIN OVER THE EASTERN HALF OF THE CWA THROUGH EARLY THIS
EVENING. WATER VAPOR IMAGERY AND LATEST RUC ANALYSIS HAS UPPER
TROUGH OVER SE MO/W IL THIS AFTERNOON AND IS EXPECTED TO MAKES ITS
WAY EASTWARD TO IN/OH LINE BY 06Z AND BRING AN END TO THE PRECIP BY
LATE TONIGHT TO THE EASTERN CWA. SFC HIGH PRESSURE TO BUILD INTO THE
REGION ON WEDNESDAY AND BRING A QUIET WEATHER PATTERN TO THE REGION
HEADING TOWARD THE THANKSGIVING HOLIDAY ALONG WITH SEASONABLE TEMPS
WITH HIGHS WEDNESDAY NEAR 50 AND L30S FOR LOWS.
&&
.LONG TERM.../THURSDAY THROUGH TUESDAY/
MODELS IN GOOD AGREEMENT LATE THIS WEEK THAT A GRADUALLY
STRENGTHENING LONG WAVE TROF WILL PROGRESS EASTWARD ACROSS THE WRN
U.S. WHILE AHEAD OF IT A STRONG UPR LEVEL RIDGE WILL MOVE EAST
ACROSS ERN PORTIONS OF THE COUNTRY. THIS SHOULD RESULT IN A WARM DRY
AIRMASS IMPACTING OUR CWA THU-FRI. LITTLE CLOUDINESS AND DECENT
MIXING FOR THIS TIME OF YEAR...ESPECIALLY FRIDAY... SHOULD ALLOW
HIGHS TO REACH THE M50S THU AND THE L60S FRI OVER MOST OF THE CWA.
TEMPS SHOULD REMAIN ABOVE NORMAL SATURDAY... BUT WITH UPR RIDGE
MOVG TO THE EAST COAST AND INCRSG CLOUDS AND PRBLY EVENTUALLY
SHOWERS ASSOCIATED WITH THE APCHG TROF SPREADING INTO THE CWA DURING
THE DAY... HIGHS SHOULD BE A BIT LOWER THAN FRIDAY... IN THE M50S.
THE LONG WAVE IS FCST BY ALL OPERATIONAL MEDIUM RANGE MODELS TO
CLOSE/CUT OFF OVER THE CENTRAL U.S. SUNDAY... BUT LARGE DIFFERENCES
REMAIN ON WHERE THIS WILL OCCUR BOTH AMONG LATEST GUIDANCE AND AMONG
THEIR RESPECTIVE RECENT RUNS. GFS ENSEMBLES ALSO SUGGESTING CUT OFF
LOW WILL DEVELOP BUT SPREAD IS VERY LARGE. THUS, CONFIDENCE IN LONG
RANGE FCST GOOD THROUGH SAT... THEN GOES DOWNHILL SUNDAY THROUGH
TUE... THOUGH DOES APPEAR THAT TEMPS WILL BE CONSIDERABLY
COOLER...CLOSER TO IF NOT BLO NORMAL EARLY NEXT WEEK. ALSO HARD ATTM
TO LEAVE OUT A CHC OF PRECIP IN EACH 12HR PERIOD SUN-TUE GIVEN
POTENTIAL FOR LOW CLOSING/CUTTING OFF OVER CENTRAL U.S. SUNDAY AND
THEN SLOWLY LIFTING OUT TO THE NE MON-TUE.
&&
.AVIATION... /18Z TAFS/
KIWX RADAR SHOWING WIDESPREAD RAIN OVER THE AREA THIS AFTERNOON AND
IS EXPECTED TO CONTINUE INTO THE EARLY EVENING HOURS. 17Z OBS
SHOWING IFR CONDITIONS WORKING UP TOWARD BOTH TAF SITES AND WILL
TREND THAT DIRECTION ACCORDINGLY. GUSTY EAST WINDS WILL BACK AROUND
TO THE NORTH OVERNIGHT WITH THE PASSAGE OF SFC LOW. HIGH PRESSURE
WILL BUILD INTO THE REGION AND VFR CONDITIONS WILL PREVAIL BY EARLY
WEDNESDAY MORNING.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST WEDNESDAY FOR LMZ043-046.
&&
$$
SHORT TERM...LOGSDON
LONG TERM...JT
AVIATION...LOGSDON
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
122 AM EST TUE NOV 22 2011
.AVIATION... /06 UTC TAFS/
MINOR TWEAKS TO ONGOING FCST. LARGE FLUX OF MSTR INTO NRN IN LTR
THIS AM AS STORM SYSTEM CURRENTLY OVR NCNLT ARK DEEPENS AND TRACKS
INTO SERN IN BY MIDDAY. EXPECT RAPID DETERIORATION TO IFR MET CONDS
WITH ONSET OF RAFL...AND FURTHER TO AT OR BLO LIFR CONDS AFTR FEW
HOURS OF CONTINUOUS RAFL BRINGING SATURATION LVL FURTHER TOWRD SFC.
TRENDED KSBN ABOVE FUEL ATL TOWARD END OF FCST PD AS SYSTEM PULLS
WELL EAST INTO NERN/ERN OH BY 06 UTC.
&&
.UPDATE...
SOME EROSION OF LOW CLOUD DECK ACROSS SOUTHERN LOWER MICHIGAN INTO
EXTREME NORTHERN INDIANA NOTED EARLY THIS AFTERNOON. SATELLITE
IMAGERY EARLY THIS EVENING INDICATES LITTLE OVERALL CHANGE IN
POSITION OF NORTHERN EXTENT OF THIS LOW CLOUD DECK RUNNING ROUGHLY
FROM KVPZ...TO KGSH...JUST NORTH OF KDFI. SLIGHT VEERING OF LOW
LEVEL WINDS IS ANTICIPATED LATE THIS EVENING INTO THE OVERNIGHT AS
AN UPPER LEVEL TROUGH CONTINUES TO PULL OUT OF THE ROCKIES INTO THE
SOUTHERN PLAINS. A TIGHT LOW LEVEL THETA-E BOUNDARY WILL BEGIN TO
ADVECT BACK NORTHWARD OVERNIGHT...AND THUS SHOULD SEE GRADUAL
NORTHWARD EXPANSION OF THIS LOW CLOUD DECK ACROSS THE FAR NORTH
OVERNIGHT. IN THE MEANTIME...MOSTLY CLEAR TO PARTLY CLOUDY SKIES
HAVE ALLOWED TEMPERATURES TO DROP INTO THE MID 30S ACROSS THE FAR
NORTH...ALTHOUGH THESE READINGS WILL LIKELY BE CLOSE TO MINS FOR THE
NIGHT. JUST SOME MINOR TWEAKS TO SKY COVER AND TEMPS MADE TO ACCOUNT
FOR THESE TRENDS...BUT OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING
FORECAST WITH MEASURABLE PRECIP MOST LIKELY HOLDING OFF UNTIL TOWARD
12Z ACROSS THE SOUTH.
&&
.PREV DISCUSSION... /ISSUED 718 PM EST MON NOV 21 2011/
AVIATION...
00Z TAFS...CIG TRENDS AND TIMING PRECIPITATION ONSET WILL BE THE
PRIMARY AVIATION FORECAST CONCERNS DURING THIS CYCLE.
PERSISTENT LOW CLOUD DECK ACROSS NORTHERN INDIANA...APPARENTLY
ENHANCED BY UPWIND LAKE ERIE BOUNDARY LAYER MODIFICATION HAS
SLOWLY ERODED ACROSS EXTREME NORTHERN INDIANA EARLIER THIS
AFTERNOON LEAVING KSBN WITH SOME JUST CIRRUS. LATEST SATELLITE
IMAGERY SUGGESTS THE NORTHERN EDGE OF THIS MVFR DECK EXTENDS FROM
NEAR KOXI TO KGSH TO JUST WEST OF KTOL. AS AN UPPER LEVEL TROUGH
ACROSS THE ROCKIES EJECTS INTO THE PLAINS TONIGHT...STALLED LOW
LEVEL MOISTURE GRADIENT SHOULD BEGIN TO LIFT SLIGHTLY BACK
NORTHWARD ACROSS FAR NORTHERN INDIANA EVENTUALLY ALLOWING A RETURN
TO MVFR DECK AT KSBN OVERNIGHT. DO NOT SEE MUCH POTENTIAL FOR
SIGNIFICANT IMPROVEMENT AT KFWA...WITH TREND TO IFR CIGS EXPECTED
LATER TONIGHT AS THIS BOUNDARY LIFTS NORTHWARD. STRONG ISENTROPIC
UPGLIDE TO OVERSPREAD NORTHERN INDIANA FROM SOUTH TO NORTH ON
TUESDAY MORNING ALLOWING FOR A WIDESPREAD RAIN EVENT. EVEN AFTER
THE INITIAL ISENTROPIC LIFT SURGE...STRONGER DEFORMATION FORCING
SHOULD MAINTAIN RAIN AT TERMINALS THROUGH THE END OF THE
PERIOD. DO NOT ENVISION MUCH IMPROVEMENT AT TERMINALS IN TERMS OF
FLIGHT CATEGORY...WITH LIFR CONDITIONS APPEARING TO BE A GOOD
POSSIBILITY AT KFWA ON TUESDAY.
&&
PREV DISCUSSION... /ISSUED 304 PM EST MON NOV 21 2011/
SHORT TERM...
TONIGHT THROUGH TUESDAY NIGHT...
WATER VAPOR IMAGERY AND LATEST RUC ANALYSIS DEPICTING SHORT WAVE
ENERGY EJECTING OUT OF THE BASE OF UPPER TROUGH ALONG SW US/MEX
BORDER THIS AFTERNOON. THIS WILL QUICKLY MOVE THROUGH THE MORE
PROGRESSIVE ZONAL FLOW EAST OF THE MISSISSIPPI AND RESULT IN SFC LOW
DEEPENING AND MOVING ALONG THE OHIO RIVER VALLEY ON TUESDAY.
FORECAST AREA WILL BE IN THE OVERRUNNING PRECIP NORTH OF THIS SYSTEM
MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS. PRONOUNCED
BACKING OF THE WINDS ALONG THE 300K THETA SFC WILL LEAD TO ENHANCED
ISENTROPIC ASCENT OVER THE AREA TUESDAY MORNING...BUT WILL TAKE SOME
TIME TO OVERCOME MID LEVEL DRYING...SO HAVE BACKED DOWN A BIT ON
POPS IN THE 12-18Z TIMEFRAME OVER THE NORTHERN HALF OF THE CWA.
ENTIRE COLUMN WILL THEN QUICKLY SATURATE EARLY TUESDAY AFTERNOON
LENDING CREDENCE TO A DEFINITE RAIN EVENT OVER ALL OF THE FORECAST
AREA TUESDAY AFTERNOON/EVENING. WHILE AXIS OF HEAVIEST PRECIP
EXPECTED TO BE SOUTH OF THE FORECAST AREA...SOUTHERN CWA COULD STILL
SEE IN EXCESS OF ONE INCH OF RAIN. SYSTEM TO EXIT THE AREA TUESDAY
NITE WITH JUST CHANCE POPS LEFT IN SE CWA AFTER MIDNIGHT. SOUTHERLY
TRACK OF SFC LOW WILL KEEP FCST AREA IN COOL EASTERLY FLOW AT LOW
LEVELS WHICH WILL HAMPER MIXING DOWN WAA ALOFT...HAVE CUT HIGHS TUE
FROM CURRENT FCST MORE TOWARD LATEST MOS GUIDANCE TO BETTER REFLECT
THIS THINKING.
&&
LONG TERM...
RIDGING SFC AND ALOFT TO BLD IN ACRS THE CWA TO START THE PD ON WED
BEHIND DEPARTING SHRT TERM SYS AND APCHG DEEP LYRD TROUGH CROSSING
THE ROCKIES FRI. BIGGEST CHG WAS TO BUMP TEMPS CONSIDERABLY THU-SAT
AND AGAINST PREVAILING ALLBLEND PROCEDURE WHICH AGAIN TDA WAS BIASED
WET AND COOL.
OTHERWISE PROBS ABOUND W/POTENTIAL PHASING ISSUED RELEGATED TO SPLIT
STREAM FLW ACRS THE WRN US LT WEEK AND NXT WEEKEND. GREATER
CONTINUITY LIES W/OP GFS AND ECM/GFS ENSEMBLES AND HAVE GENERALLY
FOLLOWED SUGGESTION OF MODEL CONSENSUS THIS AFTN ESP IN LIGHT OF
MORE AGREEABLE SLOWING TREND SEEN IN SUBSEQUENT MODEL ITERATIONS
SINCE YDA AND DISCUSSED YDA. THUS DROPPED FRI NIGHT PCPN MENTION
ALTOGETHER AND NOTCHED W-E GRADIENT FURTHER SAT. REMAINDER ON TRACK
ATTM TIED TO PROGGED DEEP MID MS VALLEY CUTOFF LT NXT WEEKEND YET
STILL HIGHLY UNCERTAIN W/CONSIDERABLE MODEL SPREAD ALOFT NOT TO
MENTION VARIOUS PLACEMENT VAGARIES. THUS WILL HOLD SHORT OF ANY
PERCEIVED LIKELY MENTION AT THIS TIME IN LIGHT OF THE UNCERTAINTY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LOGSDON
LONG TERM...T
AVIATION...MURPHY
UPDATE...MARSILI
AREA FORECAST DISCUSSION
NWS TOPEKA KS
306 PM CST TUE NOV 22 2011
.DISCUSSION...
SHORT RANGE FORECAST (TODAY THROUGH WEDNESDAY)
20Z WATER VAPOR SHOWS THE UPPER WAVE THAT BROUGHT THE RAIN THIS
MORNING CONTINUES TO MOVE EAST WITH A SHORTWAVE RIDGE BUILDING INTO
THE CENTRAL PLAINS. AT THE SFC THERE WAS A BROAD AND WEAK RIDGE OVER
MUCH OF THE CENTRAL U.S.
FOR TONIGHT AND WEDNESDAY...THE MAIN CONCERN IS THE LOW CLOUDS AND
POTENTIAL FOR DENSE FOG FORMING. INCREASING SUBSIDENCE FROM THE
SHORTWAVE RIDGE SHOULD PREVENT ANY PRECIPITATION FROM OCCURRING.
HOWEVER THE LOW STRATUS HAS PREVENTED THE BOUNDARY LAYER FROM MIXING
OUT THIS AFTERNOON AND DEWPOINTS REMAIN IN THE 30S AND LOW 40S. BOTH
THE NAM AND RUC INSIST ON THE STRATUS DECK MOVING EAST EARLY THIS
EVENING. IF THIS IN FACT OCCURS...THE SETUP FOR RADIATIONAL FOG
LOOKS GOOD WITH CLEAR SKIES AND VERY LIGHT WINDS ANTICIPATED
OVERNIGHT. RIGHT NOW THE FORECAST HAS MIN TEMPS FORECAST TO BE
ANYWHERE BETWEEN 5 AND 10 DEGREES COOLER THAN THE CURRENT OBSERVED
DEWPOINTS. SINCE THERE CONTINUES TO BE UNCERTAINTY IN THE STRATUS
MOVING EAST...THE LOW TEMP FORECAST COULD BE TO COOL AND RADIATIONAL
COOLING MAY NOT DEVELOP. OTHERWISE I WOULD CONSIDER A DENSE FOG
ADVISORY THROUGH WEDNESDAY MORNING. THE EVENING SHIFT SHOULD BE ABLE
TO MONITOR CLOUD COVER AND SEE IF DENSE FOG WILL FORM AND THE MOST
LIKELY LOCATION FOR ITS FORMATION. OTHERWISE MODELS SHOW WARM AIR
ADVECTING IN FROM THE SOUTH FOR WEDNESDAY WITH THE BOUNDARY LAYER
MIXING TO AROUND 925MB. THIS SHOULD LEAD TO HIGHS IN THE LOWER AND
MIDDLE 60S TOMORROW AFTERNOON.
WOLTERS
MID RANGE FORECAST (WEDNESDAY NIGHT THROUGH FRIDAY)
MODEL CONTINUE TO SHOW WARM ADVECTION INCREASING WEDNESDAY NIGHT AS
WELL AS AN INCREASE IN MIXING. AS A RESULT...EXPECT LOWS TO BE 8 TO
10 DEGREES ABOVE TONIGHTS LOWS...ALTHOUGH SKIES WILL BE CLEAR.
ALTHOUGH SOME HIGH CLOUDS WILL MOVE INTO THE COUNTY WARNING AREA
(CWA) ON THANKSGIVING...THEY SHOULD NOT BE THICK ENOUGH TO OFFSET
THE PERSISTENT WARM AIR ADVECTION. AXIS OF WARMER AIR AND WARMEST
HIGH TEMPS STILL APPEARS WILL SET UP FROM NEAR SALINA INTO THE
MANHATTAN AREA WHERE TEMPS SHOULD APPROACH 70 BY MID
AFTERNOON...ALTHOUGH THE MIDDLE TO UPPER 60S LOOK IN STORE FOR
MOST LOCATIONS IN THE CWA.
LATE THURSDAY NIGHT AND ESPECIALLY DURING THE DAY FRIDAY...SOME LOW
LEVEL MOISTURE WILL BEGIN TO ADVECT NORTHWARD INTO THE
CWA...ALTHOUGH IT WILL PRIMARILY OCCUR IN THE LATTER HALF OF THE DAY
AS THE ATMOSPHERE IN THE 700-850MB LAYER WILL BE SLOW TO MOISTEN.
WILL KEEP CHANCE POPS ALL AREAS EXCEPT THE SOUTHEAST CORNER OF THE
CWA. ALSO...ELEVATED CAPE REMAINS VERY LIMITED AT BEST...SO WILL
KEEP WEATHER GRIDS AS SHOWERS FOR NOW.
ALTHOUGH FRIDAY WILL START OUT A GOOD 15 DEGREES ABOVE NORMAL...
THE AXIS OF WARMER LLVL TEMPS WILL STEADILY SHIFT SOUTHEAST OF THE
CWA AS CLOUDS THICKEN THROUGH THE DAY. THE SOUTHEAST HALF OF THE CWA
SHOULD RISE INTO THE LOWER 60S TO MIDDLE 60S....BUT THE NORTHWEST
COUNTIES SHOULD ONLY MAKE IT INTO THE MIDDLE TO UPPER 50S. 63
EXTENDED FORECAST (FRIDAY NIGHT THROUGH TUESDAY)
FRIDAY NIGHT A HIGHLY AMPLIFIED SHORTWAVE TROUGH WILL MOVE OUT OF
THE DESERT SOUTHWEST INTO THE CENTRAL PLAINS. A COLD FRONT WILL MOVE
EAST ACROSS THE STATE OF KANSAS ON FRIDAY AND GRADUALLY CLEAR THE
CWA EARLY SATURDAY MORNING. BUMPED UP PRECIPITATION CHANCES ON FRIDAY
NIGHT INTO SATURDAY MORNING WITH GOOD AGREEMENT IN THE MEDIUM TO
LONG RANGE MODELS...GOOD UPPER LEVEL SUPPORT FOR PRECIPITATION AND
MODEL SOUNDINGS INDICATING A DEEP SATURATED LAYER DURING THIS
TIME-FRAME. MODELS THEN CLOSE THE UPPER LEVEL LOW OFF TO THE EAST OF
THE CWA BUT DIFFER ON WHERE THE LOW WILL CUT OFF AND VARY FROM THE
GREAT LAKES REGION TO THE SOUTHEAST U.S. THIS IS HIGHLY DEPENDENT
UPON THE STRENGTH AND AMPLIFICATION OF THE UPPER LEVEL WAVE.
HOWEVER...THE CENTRAL U.S. WILL REMAIN ON THE WESTERN SIDE OF THE
CUT OFF LOW WHICH WILL KEEP NORTHWESTERLY FLOW AND COLD AIR
ADVECTION OVER THE REGION FOR THE REMAINDER OF THE EXTENDED FORECAST
WITH COOLER AND DRY CONDITIONS EXPECTED FOR LATE NEXT WEEKEND INTO
EARLY NEXT WEEK.
ANDERSON
&&
.AVIATION...
THE PERSISTENT IFR STRATUS IS EXPECTED TO GRADUALLY CLEAR TO VFR
EARLY TUESDAY EVENING OVER THE TERMINALS AS THE SFC RIDGE SETTLES
OVER THE REGION. NORTHWEST WINDS SWITCH TO A LIGHT WESTERLY
DIRECTION AS BOUNDARY LAYER DECOUPLES AND DRIER AIR IS ADVECTED
IN. LATEST BUFKIT SOUNDINGS INDICATE DENSE GROUND FOG DEVELOPING
TUESDAY EVENING WITH AMPLE GROUND MOISTURE PRESENT. PLACED LIFR
CONDITIONS AS CONFIDENCE IS HIGH...HOWEVER TIMING IS UNCERTAIN. AT
THIS TIME...PLACED FOG FORMING AFTER 05Z BASED ON A COMBINATION OF
THE RUC AND NAM ANALYSIS.
BOWEN
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1140 AM CST TUE NOV 22 2011
...UPDATE TO AVIATION...
.DISCUSSION...
TODAY/TONIGHT...MAIN FOCUS WILL BE PRECIPITATION CHANCES OVER THE
NEXT 10 HOURS AS UPPER WAVE PASSES OVER THE CENTRAL PLAINS. AS OF
EARLY THIS MORNING...WIDESPREAD SHOWERS WERE OBSERVED OVER MUCH OF
EASTERN KANSAS. THIS DEFORMATION ACTIVITY WAS LOCATED IN A FAVORABLE
REGION OF FRONTOGENETICAL FORCING AND STRONG ASCENT. AS THE MORNING
PROGRESSES...EXPECT THE BEST ASCENT TO SHIFT MAINLY EAST OF THE CWA
AS LARGE SCALE DOWNGLIDE MOVES INTO THE AREA. PRECIPITATION WILL
GENERALLY END FROM WEST TO EAST...WITH MOST SECTIONS DRY BY MIDDAY.
WITH SURFACE TEMPERATURES THIS MORNING CONTINUING TO HOLD IN THE
MIDDLE 30S OVER NC KS TO THE LOWER 40S IN FAR EASTERN
SECTIONS...ALONG WITH H85 TEMPERATURES +3 TO +5...CONCERN FOR ANY
TYPE OF WINTRY PRECIPITATION HAS BEEN MITIGATED. MUCH DRIER AIR
THROUGH THE TROPOSPHERE WILL ADVECT INTO THE REGION THROUGHOUT THE
DAY...RESULTING IN GRADUALLY CLEARING SKIES FROM WEST TO EAST. MOST
SECTIONS SHOULD BE MOSTLY CLEAR BY SUNSET TONIGHT. THE REAR OF THE
UPPER SYSTEM HAS LITTLE ASSOCIATED COLD AIR...WHICH WILL ALLOW
MODEST MODIFICATION OF THE AIRMASS THIS AFTERNOON...ESPECIALLY
SECTIONS THAT EXPERIENCE A MODEST PERIOD OF SURFACE HEATING.
AFTERNOON READINGS WILL TOP OUT IN THE UPPER 40S TO LOWER 50S. A
QUIET NIGHT IS EXPECTED WITH MOSTLY CLEAR SKIES AND READINGS FALLING
INTO THE UPPER 20S TO LOWER 30S. SOME PATCHY FOG MAY BE REALIZED
AFTER MIDNIGHT OVER THE EASTERN QUARTER OF THE CWA...ESP IN
VALLEYS...WITH MOIST GROUNDS AND LIGHT SFC WINDS IN PLACE.
WEDNESDAY INTO THURSDAY...AN AMPLIFICATION TO THE PATTERN IS
EXPECTED BY MIDWEEK WITH UPPER LEVEL RIDGING OCCURRING OVER MUCH OF
THE CENTRAL PLAINS. AT THE SURFACE...HIGH PRESSURE WILL MOVE TO THE
EAST WITH A LEE TROUGH FORMING ACROSS THE HIGH PLAINS...RESULTING IN
SOUTHERLY FLOW RETURNING TO THE AREA. TEMPERATURES WILL BE
MILD...WITH MAXIMUM READINGS APPROACHING OR TOPPING THE 60 DEGREE
MARK EACH AFTERNOON. A BREEZY DAY CAN BE EXPECTED ON THURSDAY AS THE
SOUTHERLY FLOW STRENGTHENS...ALONG WITH INCREASING MOISTURE...WILL
MAKE FOR A WARM THU NIGHT WITH LOWS IN THE MIDDLE 40S.
EXTENDED...A POTENT SHORTWAVE TROUGH WILL EJECT FROM THE FOUR
CORNERS REGION INTO THE PLAINS ON FRIDAY. IN ADVANCE OF THE
SYSTEM...MODEST SOUTHERLY SFC FLOW WILL CONTINUE ON FRIDAY...WITH
HIGHS IN THE 58-62 RANGE. A COLD FRONT WILL SLIDE THROUGH THE CWA
FRIDAY AFTERNOON/EVENING...AND WITH GOOD UPPER LEVEL
SUPPORT...PRECIPITATION CHANCES LOOK GOOD FRIDAY EVENING/NIGHT.
ATTM...LITTLE IN THE WAY OF APPRECIABLE INSTABILITY WITH MUCAPE
VALUES UNDER 100 J/KG...THEREFORE REMOVED ISO THUNDER. THEREAFTER
FORECAST LOOKS DRY AND COOLER. MODELS STILL TRYING TO ACQUIRE BETTER
HANDLE ON DEPARTING UPPER TROUGH AND DEGREE OF
AMPLIFICATION/EVOLUTION OVER THE WEEKEND ACROSS THE MID MISSISSIPPI
VALLEY REGION...WHICH HAS SOME IMPACT TO TEMPERATURE TRENDS IN THE
FAR EXTENDED. NO OTHER SIGNIFICANT DEVIATIONS TO PREVIOUS PACKAGE.
BLAIR
&&
.AVIATION...
THE PERSISTENT IFR STRATUS IS EXPECTED TO GRADUALLY CLEAR TO VFR
EARLY TUESDAY EVENING OVER THE TERMINALS AS THE SFC RIDGE SETTLES
OVER THE REGION. NORTHWEST WINDS SWITCH TO A LIGHT WESTERLY
DIRECTION AS BOUNDARY LAYER DECOUPLES AND DRIER AIR IS ADVECTED
IN. LATEST BUFKIT SOUNDINGS INDICATE DENSE GROUND FOG DEVELOPING
TUESDAY EVENING WITH AMPLE GROUND MOISTURE PRESENT. PLACED LIFR
CONDITIONS AS CONFIDENCE IS HIGH...HOWEVER TIMING IS UNCERTAIN. AT
THIS TIME...PLACED FOG FORMING AFTER 05Z BASED ON A COMBINATION OF
THE RUC AND NAM ANALYSIS.
BOWEN
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1248 PM EST TUE NOV 22 2011
...Updated Aviation Discussion...
Forecast Update #2...
Warm front has moved north into southern Indiana late this morning.
Temps on south side of front have surged several degrees with its
passage. Widespread moderate to embedded heavy rain this morning
within isentropic lift zone north of warm front has moved well out
of our area at this time. This has left behind a relatively benign
axis of showers over our eastern and southern forecast area. It is
this area where surface-based lifted indices show -1 to -2. Isolated
storm redevelopment is expected in this area this afternoon, within
or near the only area that remains in SPC`s reduced slight risk area
over central Kentucky.
To the west, clouds remain very dense which will not allow
destabilization through insolation. However, with a strong low-level
jet, low-level warm advection has been significant with boundary-
layer warming through advection. As the surface low moves northeast
this afternoon, it still looks like scattered to perhaps numerous
showers and a few thunderstorms may redevelop this afternoon over
much of central Kentucky into southern Indiana. With such wind
fields, still can`t rule out isolated strong wind gusts with any
cells which develop. In reality, with limited instability (moist
adiabatic lapse rates aloft), there should be little or no lightning
with any convection which forms. Will continue to monitor trends.
Another forecast update to account for latest trends will be sent
shortly.
Forecast Update #1...
Steady rain with embedded pockets of heavy rain has been the rule
through mid morning north of the warm front, which extends east-
northeast along the Ohio River from low pressure centered over
southeast MO at 14 UTC. Rainfall rates from the embedded pockets of
heavy rain have resulted in significant ponding of water on some
roads, underpasses, and low spots, but we have received no reports
of flooding at this time. Have received several reports of rainfall
around one inch since last night, with a couple reports up to 1.5
inches. The heaviest rains will move northeast out of our area late
this morning. This will still leave an axis of showers and a few
thunderstorms over central KY well ahead of the cold front.
The question remains whether additional storms can fire this
afternoon with any potential for severe. Low-level wind fields still
will be strong over KY into southern IN along and south of warm
front. However, primary instability will remain south over TN Valley
into Gulf States. In those locations, current radar already shows a
line of thunderstorms from parts of middle TN and especially
southwest in central LA.
As this axis of showers and storms moves east this afternoon, could
see some stronger/isolated severe storms develop over our southern/
southeastern forecast area (eastern parts of south-central KY) this
afternoon where current satellite imagery suggests clouds are not as
dense and surface-based lifted index values are already below zero.
Chances for any severe cell development over rest of central KY
appears predicated on any additional cells developing behind current
activity. It`s this area which is shrouded by extensive denser cloud
cover right now, although with temps in 60s and dewpoints in lower
60s in this area, there may be just enough instability to allow a
some low-top storms to develop, perhaps with little lightning, but
still with isolated strong to perhaps severe wind potential given
ambient low-level wind fields and shear. 12z NAM, 06z in-house WRF,
and latest HRRR suggest development of a narrow line later today
right along the cold front. Will maintain situational awareness on
this throughout the day.
For now, have updated precip/POP trends to account for latest radar
observations and expected short-term trends. Max temps also are
problematic. For now, kept lower 70s downstate considering current
temps and less dense cloud cover. Over the north, lowered temps a
bit, but they should still rise today as warm front continues to
move northeast.
&&
.Short Term (Today - Tonight)...
...Heavy Rain and Severe Weather Possible Today...
Low pressure over Arkansas at 07Z will move quickly to the northeast
as it deepens today, crossing southeast Missouri this morning and
south central Indiana this afternoon. A warm front reaches from the
low northeast up the length of the Ohio River. A pre-frontal trof
will enter the far west CWA around 19Z with the cold front following
two or three hours later, while the warm front moves very little
until the low passes by just to our north.
A large mass of rain with embedded thunder over the middle
Mississippi Valley early this morning will move northeast ahead of
the surface low and will primarily affect southern Indiana and far
northern Kentucky through the morning hours. An inch of rain is not
out of the question with this activity, especially from Hoosier
National Forest over to Scottsburg. South of there, scattered
showers and isolated thunderstorms will be possible this morning as
was the case overnight. Because the heaviest rain is expected to
move over areas that have received the least rain during the past
few wet days, widespread flooding is not anticipated at this time.
Localized minor flooding will be possible in pockets of particularly
heavy rain and poor drainage.
A long squall line is still expected to erupt ahead of the advancing
trof and front this afternoon. The main question is how far north
it will be able to stretch. With widespread stabilizing rains and
clouds in southern Indiana this morning, the feeling is that the
severe threat will be primarily south of the Ohio River today,
especially south of a Hartford to Taylorsville to Cynthiana line.
Surface dew points will be in the lower 60s with precipitable water
values well above seasonal normals in the 1.2 to 1.5 inch range.
Instability will not be great, with boundary layer lifted index
values bottoming out only around -1. Nevertheless there are strong
dynamics with this system with a 90kt 500hPa jet max streaming over
head this afternoon along with strong low level winds and
significant 0-1km and 0-3km helicity. Given the expected QLCS
nature of the storms it appears that strong gusty winds will be the
main threat, and although the better tornado chances will be over
MS/AL/TN we can`t rule out an isolated tornado or two in central
Kentucky. Large hail will be possible in the taller storms.
With all the wind associated with this system, the storms will be
fast movers...possibly around 50 mph. Those strong SSW winds will
also bring very warm air into the region, with highs expected to
range from the middle 70s along the Tennessee border to the lower
70s near the Ohio River and mid to upper 60s in southern Indiana
where there will be more rain and more time spent on the cool side
of the warm front.
A possible fly in the ointment: over the past couple of days,
various model solutions have suggested that the LMK CWA will be in a
relative lull between widespread showers and embedded thunder to the
north and severe storms to the south. Today the GFS40 and
especially the NAM12 have backed away from that slightly and are
more suggestive that central Kentucky will indeed see a squall line,
however the SPC SREF is still holding on to the Kentucky gap
solution. Having said that, however, the SPC SREF is doing some odd
things in its solution this morning and is not a model of choice at
this time.
Bottom line: best chance for storms today will be along and south
of a line from Hartford to Taylorsville to Cynthiana. Best timing
looks to be from as early as 11am CST in the far west for
commencement, to as late as 8pm EST in the far northeast for
conclusion. Strong winds are the main threat, with isolated
tornadoes and isolated large hail as secondary threats.
Behind the front tonight temperatures will plunge but not far enough
for any snow. Light post frontal rain will be possible this
evening, gradually tapering off overnight. Lows will be in the
middle to upper 40s with west to northwest winds of 10 to 15 mph.
.Long term (Wednesday - Monday)...
Other than a few lingering light rain showers over the far eastern
Bluegrass counties, conditions will improve on Wednesday behind the
storm system. Surface high pressure and ridging aloft will move in
behind the system, keeping our conditions pleasant for the rest of
Wednesday, and especially for the Thanksgiving holiday. Look for
highs Wednesday to be a bit cool, but with ample sunshine moving in.
Highs in the 50s can be expected, followed by a bright and sunny
turkey day with highs in the upper 50s and low 60s. By Friday, the
surface high pressure will slide east, turning our winds southerly.
Anyone shopping early in the morning will be met with temperatures
around 40 increasing into the low and mid 60s with a few wind gusts
here and there.
After Friday, we will see another system approach from the west next
weekend as troughing will not only develop off the southwest
California coast, but a stronger, northern stream trough will enter
the Pacific NW. These will combine to generate surface low pressure
over the Plains by Saturday. The GFS develops a northern stream
surface low initially, and then shows a southern stream low taking
over by the end of the extended forecast as the upper lows wrap up
over the Mid-Mississippi Valley region. The Euro sticks with the
northern stream surface low as the dominate one. Regardless of the
details, both models indicate the reinforcing shot from the upper
disturbance in the northern stream diving southeast across the
central CONUS and overhead by late in the weekend. This entire
system looks to bring another round of heavy rainfall with embedded
thunderstorms (too early to tell if strong-severe will occur) late
Saturday over the western CWA, and then overspreading the area by
Sunday. The reinforcing northern stream trough will bring cold
temperatures aloft and saturated conditions Monday night, and
perhaps Sunday night, too. Monday night looks like a decent shot at
a rain/snow mix, but given the forecast lows for Sunday night, too,
went ahead and included the RASN mix for then, as well, especially
since this agrees with the previous extended forecaster`s thoughts.
Timing differences this far out (models continue to slow this
progression) could greatly change the outcome, so caution is
warranted.
Friday and especially Saturday could turn out to be warmer than MOS
guidance indicates if the models continue to slow the eastward
progression of the next system. At any rate, Fri-Sat will be mild
with highs in the 60s, with lows Fri. night and Sat. night in the
40s to around 50. Sunday and Monday will likely see highs in the 50s
and 40s, respectively, with each night dropping to the low to mid
30s.
&&
.Aviation (18Z TAF Issuance)...
Surface low pressure at 17 UTC was over southeast IL and will
continue to move east-northeast this afternoon along warm front
extending east from the low. Southerly surface winds south of this
front have been gusting at times to 30 mph over central Kentucky,
and this trend should continue for another few hours before winds
veer to southwest and start to diminish a bit late this afternoon.
Scattered to numerous showers will continue this afternoon along and
ahead of a cold front to the west. Instability is limited but
low-level winds remain strong (about 50 kts at 4000 ft). Scattered
low-top convection may develop this afternoon as the cold front
moves across central Kentucky. The areal extent of convection should
be limited, so have included it mainly as VCTS in TAFs or only a
2-hour TEMPO window for convection for now. Otherwise, showers with
VFR or MVFR vsbys and cigs expected this afternoon.
After cold front passes late today and this evening, winds will
switch to west and eventually northwest. It will remain cloudy with
mvfr cigs for much of the night. Low clouds will begin to clear from
northwest to southeast on Wednesday, and have reflected this near
end of current TAF valid forecast period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Updates..........TWF
Short Term.......13
Long Term........AL
Aviation.........TWF
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1156 AM EST TUE NOV 22 2011
Forecast Update #2...
Warm front has moved north into southern Indiana late this morning.
Temps on south side of front have surged several degrees with its
passage. Widespread moderate to embedded heavy rain this morning
within isentropic lift zone north of warm front has moved well out
of our area at this time. This has left behind a relatively benign
axis of showers over our eastern and southern forecast area. It is
this area where surface-based lifted indices show -1 to -2. Isolated
storm redevelopment is expected in this area this afternoon, within
or near the only area that remains in SPC`s reduced slight risk area
over central Kentucky.
To the west, clouds remain very dense which will not allow
destabilization through insolation. However, with a strong low-level
jet, low-level warm advection has been significant with boundary-
layer warming through advection. As the surface low moves northeast
this afternoon, it still looks like scattered to perhaps numerous
showers and a few thunderstorms may redevelop this afternoon over
much of central Kentucky into southern Indiana. With such wind
fields, still can`t rule out isolated strong wind gusts with any
cells which develop. In reality, with limited instability (moist
adiabatic lapse rates aloft), there should be little or no lightning
with any convection which forms. Will continue to monitor trends.
Another forecast update to account for latest trends will be sent
shortly.
Forecast Update #1...
Steady rain with embedded pockets of heavy rain has been the rule
through mid morning north of the warm front, which extends east-
northeast along the Ohio River from low pressure centered over
southeast MO at 14 UTC. Rainfall rates from the embedded pockets of
heavy rain have resulted in significant ponding of water on some
roads, underpasses, and low spots, but we have received no reports
of flooding at this time. Have received several reports of rainfall
around one inch since last night, with a couple reports up to 1.5
inches. The heaviest rains will move northeast out of our area late
this morning. This will still leave an axis of showers and a few
thunderstorms over central KY well ahead of the cold front.
The question remains whether additional storms can fire this
afternoon with any potential for severe. Low-level wind fields still
will be strong over KY into southern IN along and south of warm
front. However, primary instability will remain south over TN Valley
into Gulf States. In those locations, current radar already shows a
line of thunderstorms from parts of middle TN and especially
southwest in central LA.
As this axis of showers and storms moves east this afternoon, could
see some stronger/isolated severe storms develop over our southern/
southeastern forecast area (eastern parts of south-central KY) this
afternoon where current satellite imagery suggests clouds are not as
dense and surface-based lifted index values are already below zero.
Chances for any severe cell development over rest of central KY
appears predicated on any additional cells developing behind current
activity. It`s this area which is shrouded by extensive denser cloud
cover right now, although with temps in 60s and dewpoints in lower
60s in this area, there may be just enough instability to allow a
some low-top storms to develop, perhaps with little lightning, but
still with isolated strong to perhaps severe wind potential given
ambient low-level wind fields and shear. 12z NAM, 06z in-house WRF,
and latest HRRR suggest development of a narrow line later today
right along the cold front. Will maintain situational awareness on
this throughout the day.
For now, have updated precip/POP trends to account for latest radar
observations and expected short-term trends. Max temps also are
problematic. For now, kept lower 70s downstate considering current
temps and less dense cloud cover. Over the north, lowered temps a
bit, but they should still rise today as warm front continues to
move northeast.
&&
.Short Term (Today - Tonight)...
...Heavy Rain and Severe Weather Possible Today...
Low pressure over Arkansas at 07Z will move quickly to the northeast
as it deepens today, crossing southeast Missouri this morning and
south central Indiana this afternoon. A warm front reaches from the
low northeast up the length of the Ohio River. A pre-frontal trof
will enter the far west CWA around 19Z with the cold front following
two or three hours later, while the warm front moves very little
until the low passes by just to our north.
A large mass of rain with embedded thunder over the middle
Mississippi Valley early this morning will move northeast ahead of
the surface low and will primarily affect southern Indiana and far
northern Kentucky through the morning hours. An inch of rain is not
out of the question with this activity, especially from Hoosier
National Forest over to Scottsburg. South of there, scattered
showers and isolated thunderstorms will be possible this morning as
was the case overnight. Because the heaviest rain is expected to
move over areas that have received the least rain during the past
few wet days, widespread flooding is not anticipated at this time.
Localized minor flooding will be possible in pockets of particularly
heavy rain and poor drainage.
A long squall line is still expected to erupt ahead of the advancing
trof and front this afternoon. The main question is how far north
it will be able to stretch. With widespread stabilizing rains and
clouds in southern Indiana this morning, the feeling is that the
severe threat will be primarily south of the Ohio River today,
especially south of a Hartford to Taylorsville to Cynthiana line.
Surface dew points will be in the lower 60s with precipitable water
values well above seasonal normals in the 1.2 to 1.5 inch range.
Instability will not be great, with boundary layer lifted index
values bottoming out only around -1. Nevertheless there are strong
dynamics with this system with a 90kt 500hPa jet max streaming over
head this afternoon along with strong low level winds and
significant 0-1km and 0-3km helicity. Given the expected QLCS
nature of the storms it appears that strong gusty winds will be the
main threat, and although the better tornado chances will be over
MS/AL/TN we can`t rule out an isolated tornado or two in central
Kentucky. Large hail will be possible in the taller storms.
With all the wind associated with this system, the storms will be
fast movers...possibly around 50 mph. Those strong SSW winds will
also bring very warm air into the region, with highs expected to
range from the middle 70s along the Tennessee border to the lower
70s near the Ohio River and mid to upper 60s in southern Indiana
where there will be more rain and more time spent on the cool side
of the warm front.
A possible fly in the ointment: over the past couple of days,
various model solutions have suggested that the LMK CWA will be in a
relative lull between widespread showers and embedded thunder to the
north and severe storms to the south. Today the GFS40 and
especially the NAM12 have backed away from that slightly and are
more suggestive that central Kentucky will indeed see a squall line,
however the SPC SREF is still holding on to the Kentucky gap
solution. Having said that, however, the SPC SREF is doing some odd
things in its solution this morning and is not a model of choice at
this time.
Bottom line: best chance for storms today will be along and south
of a line from Hartford to Taylorsville to Cynthiana. Best timing
looks to be from as early as 11am CST in the far west for
commencement, to as late as 8pm EST in the far northeast for
conclusion. Strong winds are the main threat, with isolated
tornadoes and isolated large hail as secondary threats.
Behind the front tonight temperatures will plunge but not far enough
for any snow. Light post frontal rain will be possible this
evening, gradually tapering off overnight. Lows will be in the
middle to upper 40s with west to northwest winds of 10 to 15 mph.
.Long term (Wednesday - Monday)...
Other than a few lingering light rain showers over the far eastern
Bluegrass counties, conditions will improve on Wednesday behind the
storm system. Surface high pressure and ridging aloft will move in
behind the system, keeping our conditions pleasant for the rest of
Wednesday, and especially for the Thanksgiving holiday. Look for
highs Wednesday to be a bit cool, but with ample sunshine moving in.
Highs in the 50s can be expected, followed by a bright and sunny
turkey day with highs in the upper 50s and low 60s. By Friday, the
surface high pressure will slide east, turning our winds southerly.
Anyone shopping early in the morning will be met with temperatures
around 40 increasing into the low and mid 60s with a few wind gusts
here and there.
After Friday, we will see another system approach from the west next
weekend as troughing will not only develop off the southwest
California coast, but a stronger, northern stream trough will enter
the Pacific NW. These will combine to generate surface low pressure
over the Plains by Saturday. The GFS develops a northern stream
surface low initially, and then shows a southern stream low taking
over by the end of the extended forecast as the upper lows wrap up
over the Mid-Mississippi Valley region. The Euro sticks with the
northern stream surface low as the dominate one. Regardless of the
details, both models indicate the reinforcing shot from the upper
disturbance in the northern stream diving southeast across the
central CONUS and overhead by late in the weekend. This entire
system looks to bring another round of heavy rainfall with embedded
thunderstorms (too early to tell if strong-severe will occur) late
Saturday over the western CWA, and then overspreading the area by
Sunday. The reinforcing northern stream trough will bring cold
temperatures aloft and saturated conditions Monday night, and
perhaps Sunday night, too. Monday night looks like a decent shot at
a rain/snow mix, but given the forecast lows for Sunday night, too,
went ahead and included the RASN mix for then, as well, especially
since this agrees with the previous extended forecaster`s thoughts.
Timing differences this far out (models continue to slow this
progression) could greatly change the outcome, so caution is
warranted.
Friday and especially Saturday could turn out to be warmer than MOS
guidance indicates if the models continue to slow the eastward
progression of the next system. At any rate, Fri-Sat will be mild
with highs in the 60s, with lows Fri. night and Sat. night in the
40s to around 50. Sunday and Monday will likely see highs in the 50s
and 40s, respectively, with each night dropping to the low to mid
30s.
&&
.Aviation (12Z TAF Issuance)...
Low pressure moving from southeast Missouri to eastern Indiana today
will pull a warm front across southern Indiana this morning and a
cold front through central Kentucky this afternoon. Widespread
showers can be expected until mid morning in association with the
warm front, especially at SDF. Fortunately most of the ceilings in
the area of showers are VFR with only occasional forays into MVFR
VSBY.
A squall line is expected to form ahead of the cold front this
afternoon, primarily from southern Kentucky south into the Tennessee
Valley. BWG will be most affected, with LEX grazed by the northern
tip of the squall line. SDF may be just a bit too far north to be
significantly influenced by the squalls. So, will bring TSRA into
BWG and LEX when we expect the line of storms to push through, and
will keep SDF at SHRA with VCTS.
SSW winds will be brisk and gusty ahead of the front today,
especially this afternoon. With the passage of the front early this
evening, winds will switch to the WNW. At SDF and LEX winds will
remain brisk and gusty, while BWG won`t see as high of a wind since
they will be farther away from the low crossing from Indiana into
Ohio.
Low clouds are expected to sweep in behind the departing system.
They should last through the night and possibly into Wednesday
morning.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Updates..........TWF
Short Term.......13
Long Term........AL
Aviation.........13
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1005 AM EST TUE NOV 22 2011
...Forecast Update...
Steady rain with embedded pockets of heavy rain has been the rule
through mid morning north of the warm front, which extends east-
northeast along the Ohio River from low pressure centered over
southeast MO at 14 UTC. Rainfall rates from the embedded pockets of
heavy rain have resulted in significant ponding of water on some
roads, underpasses, and low spots, but we have received no reports
of flooding at this time. Have received several reports of rainfall
around one inch since last night, with a couple reports up to 1.5
inches. The heaviest rains will move northeast out of our area late
this morning. This will still leave an axis of showers and a few
thunderstorms over central KY well ahead of the cold front.
The question remains whether additional storms can fire this
afternoon with any potential for severe. Low-level wind fields still
will be strong over KY into southern IN along and south of warm
front. However, primary instability will remain south over TN Valley
into Gulf States. In those locations, current radar already shows a
line of thunderstorms from parts of middle TN and especially
southwest in central LA.
As this axis of showers and storms moves east this afternoon, could
see some stronger/isolated severe storms develop over our southern/
southeastern forecast area (eastern parts of south-central KY) this
afternoon where current satellite imagery suggests clouds are not as
dense and surface-based lifted index values are already below zero.
Chances for any severe cell development over rest of central KY
appears predicated on any additional cells developing behind current
activity. It`s this area which is shrouded by extensive denser cloud
cover right now, although with temps in 60s and dewpoints in lower
60s in this area, there may be just enough instability to allow a
some low-top storms to develop, perhaps with little lightning, but
still with isolated strong to perhaps severe wind potential given
ambient low-level wind fields and shear. 12z NAM, 06z in-house WRF,
and latest HRRR suggest development of a narrow line later today
right along the cold front. Will maintain situational awareness on
this throughout the day.
For now, have updated precip/POP trends to account for latest radar
observations and expected short-term trends. Max temps also are
problematic. For now, kept lower 70s downstate considering current
temps and less dense cloud cover. Over the north, lowered temps a
bit, but they should still rise today as warm front continues to
move northeast.
&&
.Short Term (Today - Tonight)...
...Heavy Rain and Severe Weather Possible Today...
Low pressure over Arkansas at 07Z will move quickly to the northeast
as it deepens today, crossing southeast Missouri this morning and
south central Indiana this afternoon. A warm front reaches from the
low northeast up the length of the Ohio River. A pre-frontal trof
will enter the far west CWA around 19Z with the cold front following
two or three hours later, while the warm front moves very little
until the low passes by just to our north.
A large mass of rain with embedded thunder over the middle
Mississippi Valley early this morning will move northeast ahead of
the surface low and will primarily affect southern Indiana and far
northern Kentucky through the morning hours. An inch of rain is not
out of the question with this activity, especially from Hoosier
National Forest over to Scottsburg. South of there, scattered
showers and isolated thunderstorms will be possible this morning as
was the case overnight. Because the heaviest rain is expected to
move over areas that have received the least rain during the past
few wet days, widespread flooding is not anticipated at this time.
Localized minor flooding will be possible in pockets of particularly
heavy rain and poor drainage.
A long squall line is still expected to erupt ahead of the advancing
trof and front this afternoon. The main question is how far north
it will be able to stretch. With widespread stabilizing rains and
clouds in southern Indiana this morning, the feeling is that the
severe threat will be primarily south of the Ohio River today,
especially south of a Hartford to Taylorsville to Cynthiana line.
Surface dew points will be in the lower 60s with precipitable water
values well above seasonal normals in the 1.2 to 1.5 inch range.
Instability will not be great, with boundary layer lifted index
values bottoming out only around -1. Nevertheless there are strong
dynamics with this system with a 90kt 500hPa jet max streaming over
head this afternoon along with strong low level winds and
significant 0-1km and 0-3km helicity. Given the expected QLCS
nature of the storms it appears that strong gusty winds will be the
main threat, and although the better tornado chances will be over
MS/AL/TN we can`t rule out an isolated tornado or two in central
Kentucky. Large hail will be possible in the taller storms.
With all the wind associated with this system, the storms will be
fast movers...possibly around 50 mph. Those strong SSW winds will
also bring very warm air into the region, with highs expected to
range from the middle 70s along the Tennessee border to the lower
70s near the Ohio River and mid to upper 60s in southern Indiana
where there will be more rain and more time spent on the cool side
of the warm front.
A possible fly in the ointment: over the past couple of days,
various model solutions have suggested that the LMK CWA will be in a
relative lull between widespread showers and embedded thunder to the
north and severe storms to the south. Today the GFS40 and
especially the NAM12 have backed away from that slightly and are
more suggestive that central Kentucky will indeed see a squall line,
however the SPC SREF is still holding on to the Kentucky gap
solution. Having said that, however, the SPC SREF is doing some odd
things in its solution this morning and is not a model of choice at
this time.
Bottom line: best chance for storms today will be along and south
of a line from Hartford to Taylorsville to Cynthiana. Best timing
looks to be from as early as 11am CST in the far west for
commencement, to as late as 8pm EST in the far northeast for
conclusion. Strong winds are the main threat, with isolated
tornadoes and isolated large hail as secondary threats.
Behind the front tonight temperatures will plunge but not far enough
for any snow. Light post frontal rain will be possible this
evening, gradually tapering off overnight. Lows will be in the
middle to upper 40s with west to northwest winds of 10 to 15 mph.
.Long term (Wednesday - Monday)...
Other than a few lingering light rain showers over the far eastern
Bluegrass counties, conditions will improve on Wednesday behind the
storm system. Surface high pressure and ridging aloft will move in
behind the system, keeping our conditions pleasant for the rest of
Wednesday, and especially for the Thanksgiving holiday. Look for
highs Wednesday to be a bit cool, but with ample sunshine moving in.
Highs in the 50s can be expected, followed by a bright and sunny
turkey day with highs in the upper 50s and low 60s. By Friday, the
surface high pressure will slide east, turning our winds southerly.
Anyone shopping early in the morning will be met with temperatures
around 40 increasing into the low and mid 60s with a few wind gusts
here and there.
After Friday, we will see another system approach from the west next
weekend as troughing will not only develop off the southwest
California coast, but a stronger, northern stream trough will enter
the Pacific NW. These will combine to generate surface low pressure
over the Plains by Saturday. The GFS develops a northern stream
surface low initially, and then shows a southern stream low taking
over by the end of the extended forecast as the upper lows wrap up
over the Mid-Mississippi Valley region. The Euro sticks with the
northern stream surface low as the dominate one. Regardless of the
details, both models indicate the reinforcing shot from the upper
disturbance in the northern stream diving southeast across the
central CONUS and overhead by late in the weekend. This entire
system looks to bring another round of heavy rainfall with embedded
thunderstorms (too early to tell if strong-severe will occur) late
Saturday over the western CWA, and then overspreading the area by
Sunday. The reinforcing northern stream trough will bring cold
temperatures aloft and saturated conditions Monday night, and
perhaps Sunday night, too. Monday night looks like a decent shot at
a rain/snow mix, but given the forecast lows for Sunday night, too,
went ahead and included the RASN mix for then, as well, especially
since this agrees with the previous extended forecaster`s thoughts.
Timing differences this far out (models continue to slow this
progression) could greatly change the outcome, so caution is
warranted.
Friday and especially Saturday could turn out to be warmer than MOS
guidance indicates if the models continue to slow the eastward
progression of the next system. At any rate, Fri-Sat will be mild
with highs in the 60s, with lows Fri. night and Sat. night in the
40s to around 50. Sunday and Monday will likely see highs in the 50s
and 40s, respectively, with each night dropping to the low to mid
30s.
&&
.Aviation (12Z TAF Issuance)...
Low pressure moving from southeast Missouri to eastern Indiana today
will pull a warm front across southern Indiana this morning and a
cold front through central Kentucky this afternoon. Widespread
showers can be expected until mid morning in association with the
warm front, especially at SDF. Fortunately most of the ceilings in
the area of showers are VFR with only occasional forays into MVFR
VSBY.
A squall line is expected to form ahead of the cold front this
afternoon, primarily from southern Kentucky south into the Tennessee
Valley. BWG will be most affected, with LEX grazed by the northern
tip of the squall line. SDF may be just a bit too far north to be
significantly influenced by the squalls. So, will bring TSRA into
BWG and LEX when we expect the line of storms to push through, and
will keep SDF at SHRA with VCTS.
SSW winds will be brisk and gusty ahead of the front today,
especially this afternoon. With the passage of the front early this
evening, winds will switch to the WNW. At SDF and LEX winds will
remain brisk and gusty, while BWG won`t see as high of a wind since
they will be farther away from the low crossing from Indiana into
Ohio.
Low clouds are expected to sweep in behind the departing system.
They should last through the night and possibly into Wednesday
morning.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........TWF
Short Term.......13
Long Term........AL
Aviation.........13
AREA FORECAST DISCUSSION
NWS CARIBOU ME
542 PM EST TUE NOV 22 2011
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST OF THE REGION THIS EVENING. LOW
PRESSURE WILL APPROACH LATE TONIGHT AND CROSS THE SOUTHERN GULF OF
MAINE ON WEDNESDAY. THE LOW WILL MOVE EAST OF THE REGION WEDNESDAY
NIGHT WITH HIGH PRESSURE SETTLING IN FOR THANKSGIVING DAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
UPDATE: HAVE UPDATED SKY GRIDS TO FIT CURRENT SKY CONDITIONS.
USING HRRR AND RUC MODELS HAVE SLOWED DOWN ONSET OF PRECIPITATION
ACROSS DOWNEAST FOR TONIGHT AND ACROSS NORTHERN PORTIONS FOR
WEDNESDAY. EXPECTING WET SNOW ON WEDNESDAY SO HAVE ALSO REMOVED
BLOWING SNOW FROM THE FORECAST.
COLLABORATED W/GYX ON SNOWFALL AND HEADLINES AND W/THE NERFC ON
QPF. WE LOOK TO LINE UP PRETTY WELL ATTM W/PRECIP STAYING IN THE
FORM OF SNOW NOW ALL THE WAY TO THE COAST W/THE EXCEPTION OF THE
OUTER ISLAND WHICH COULD SEE A PERIOD OF RAIN MIX IN AT TIMES ON
WEDNESDAY AND SOME SLEET DOES LOOK POSSIBLE ALONG THE COAST.
DETAILS BELOW.
DECIDED STAYING W/A BLEND OF THE NAM AND GFS THROUGH THIS FCST
TERM WHICH NOW KEEPS THE BLYR COLDER ALLOWING FOR MORE SNOW TO THE
COAST AS THE LOW TRAVELS ACROSS THE GULF OF MAINE. A SHARP CUTOFF
IS STILL ANTICIPATED ACROSS THE NORTHERN ZONES(MEZ001>004) AS THE
BEST LIFT AND 1000-700MB FRONTOGENETICAL FORCING WILL BE ACROSS
THE DOWNEAST AND COAST. A 6 HR WINDOW OF STRONG FORCING IS LIKELY
ON WEDNESDAY BEFORE THE STEADIER SNOW WINDS DOWN AS THE BEST
FORCING EXITS TO THE EAST INTO NEW BRUNSWICK. SNOW RATIOS COULD
CLIMB AS HIGH AS 12:1 AT THE HEIGHT OF THE EVENT ON WEDNESDAY
LEADING TO HIGHER SNOWFALL TOTALS. THIS IS RIGHT IN THAT SNOW GROWTH
ZONE OF -10 TO -20C. THEREFORE, THE DECISION WAS TO INCREASE THE
SNOWFALL TOTALS ACROSS THE DOWNEAST ON TO THE COAST FROM BANGOR TO
BAR HARBOR AND EAST INTO WASHINGTON COUNTY 7 TO 10 INCHES. FARTHER
NORTH UP THROUGH GREENVILLE...DOVER FOXCROFT TO TOPSFIELD, SNOW
TOTALS WILL BE LESS BUT W/SOME DECENT MID LEVEL BANDING ON
WEDNESDAY, THERE COULD BE A BRIEF PERIOD OF HEAVIER SNOW BRINGING
SNOWFALL TOTALS CLOSE TO 6-7 INCHES. NORTH OF THIS AREA...SNOWFALL
CUTS OFF W/WEAK FORCING. MDL SOUNDINGS KEEP PRECIP FROZEN FOR THE
W/LITTLE SET UP FOR SLEET ESPECIALLY THE NAM. THE GFS AND EVEN THE
RUC HINT AT THE POTENTIAL FOR SOME SLEET. CONFIDENCE IS BUILDING FOR
A SNOW EVENT EVEN TO THE COAST BUT SOME CONCERN FOR THE SLEET. IF
THE LOW HANGS OVER THE WATER LONGER AND COASTAL FRONT STAYS OFF THE
COAST, THE A CHANGEOVER WILL BE TOUGH. ATTM, DECIDED TO KEEP THE
MENTION OF SLEET IN THE FCST FOR THE COAST. SOME SUBLIMATION ON
WEDNESDAY IS LIKELY FOR DOWNEAST AND THE COAST AS TEMPERATURES ARE
EXPECTED TO PUSHING INTO THE LOWER AND MID 30S.
SO HERE IS HOW IT SHAPES UP, WINTER STORM WARNINGS ARE IN EFFECT
FOR THE CENTRAL MAINE MEZ011,031-032) ON SOUTHWARD TO THE COAST
W/ANYWHERE FROM 6 TO 10 INCHES OF SNOW EXPECTED. THIS WILL NEED TO
BE WATCHED ESPECIALLY FOR THE EASTERN SECTIONS AS A LONGER PERIOD
OF HEAVIER SNOWFALL RATES COULD VERY WELL LEAD TO HIGHER SNOW AMOUNTS
THAN ANTICIPATED. WHILE WINTER WEATHER ADVISORIES ARE UP FOR THE
GREENVILLE, MILLINOCKET AND HOULTON REGIONS FOR 2 TO 5 INCHES OF
SNOW. NORTH TO NORTHEAST WINDS WILL BE A FACTOR ON WEDNESDAY
LEADING TO BLOWING SNOW AND LOWER VISIBILITIES WHICH WILL ALLOW
FOR A HIGHER IMPACT.
AS FOR THOSE TEMPERATURES, LEANED W/A BLEND OF THE LAMP AND MAV
GUIDANCE AS THIS BLEND IS WORKING QUITE WELL W/THE LATEST
CONDITIONS. THIS ALLOWS FOR TEMPERATURES TO LEVEL OFF AFTER
MIDNIGHT TONIGHT W/CLOUDS MOVING IN AND A SLOW RISE ON WEDNESDAY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
THE FAST MOVING LOW WHICH IS EXPECTED TO BRING SNOW TO CENTRAL AND
DOWNEAST MAINE ON WEDNESDAY WILL QUICKLY MOVE EAST AND AWAY
WEDNESDAY EVENING. ANY LINGERING SNOW IN EASTERN PARTS OF THE
DOWNEAST REGION WILL TAPER OFF WEDNESDAY EVENING. THIS WILL BE
FOLLOWED BY CLEARING LATER WEDNESDAY NIGHT. HIGH PRESSURE
POSITIONED TO THE SOUTHWEST AND RIDGING NORTHEAST ACROSS THE STATE
WILL ALLOW WINDS TO CALM...AND TEMPS OVER FRESH SNOW COVER TO
DROP INTO THE TEENS OVER MUCH OF THE REGION. HIGH PRESSURE WILL
MOVE INTO THE MID ATLANTIC REGION FRIDAY AS A RETURN FLOW OF
SOUTHWESTERLY AIR NORTH OF THE HIGH MOVES ACROSS THE STATE. THIS
WILL BRING A MOSTLY SUNNY DAY DOWNEAST WITH PARTIAL SUNSHINE
ACROSS THE NORTH ON FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEAK COLD FRONTAL BOUNDARY WILL MOVE INTO THE AREA FRIDAY NIGHT
BRINGING A BAND OF CLOUDS CROSS THE REGION. THE FRONTAL BOUNDARY
WILL REMAIN NEARBY OVER THE SOUTHWESTERN PART OF THE REGION
SATURDAY THEN BEGIN TO LIFT BACK NORTH AS A WARM FRONT ON SUNDAY.
THE BOUNDARY WILL KEEP SKIES MOSTLY CLOUDY OVER THE WEEKEND
ALTHOUGH PRECIPITATION OTHER THAN A LIGHT SHOWER OR SPRINKLE IS
NOT EXPECTED. HIGH PRESSURE OVER THE MID ATLANTIC REGION WILL
BRING MILD WEATHER ON MONDAY. THE NEXT MAJOR WEATHER MAKER COULD
THEN BE A LARGE STORM SYSTEM APPROACHING LATE TUESDAY. THE LOW IS
EXPECTED TO LIFT WEST OF THE AREA PULLING AN OCCLUSION THROUGH
TUESDAY EVENING. WIND AND A PERIOD OF RAIN WOULD RESULT IF THIS
OCCURS.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
NEAR TERM: VFR STARTING IT OUT TONIGHT AND THEN THE TREND IS FOR
CONDITIONS TO DROP TO MVFR ACROSS KBGR AND KBHB AFTER MIDNIGHT AND
THEN GO TO IFR BY WEDNESDAY MORNING W/SNOW AND WIND. VFR HOLDS ON A
WHILE LONGER FOR THE NORTHERN TAFS INTO WEDNESDAY MORNING AND THEN
A DROP TO MVFR FOR A BRIEF PERIOD ESPECIALLY FOR KHUL. KHUL COULD
VERY WELL SEE IFR FOR A BRIEF TIME WEDNESDAY MORNING BEFORE
IMPROVING BY THE AFTERNOON.
SHORT TERM: CONDITIONS WILL IMPROVE TO VFR WEDNESDAY EVENING AND
REMAIN VFR THROUGH FRIDAY. VFR TO MVFR CONDITIONS ARE EXPECTED ON
SATURDAY AS A WEAK FRONTAL BOUNDARY MOVES IN.
&&
.MARINE...
NEAR TERM: COLLABORATED W/GYX ON UPGRADING THINGS TO A GALE
WARNING STARTING WEDNESDAY MORNING AND GOING THROUGH WEDNESDAY
NIGHT. A BLEND OF THE GFS AND NAM12 SHOWS SUSTAINED WINDS OF 25
TO 30 KT BY LATE WEDNESDAY MORNING W/GUSTS HITTING 35 TO POSSIBLY
40 KTS FOR A TIME ON WEDNESDAY. RAISED WAVE HEIGHTS GIVEN A ESE
WIND DIRECTION. THIS IS ABOVE THE WNAWAVE BY 2 FT..
SHORT TERM: A GALE WARNING FOR NORTH TO NORTHEAST WINDS AROUND THE
DEPARTING LOW WILL CONTINUE INTO WEDNESDAY EVENING. WINDS WILL
DIMINISH OVERNIGHT WEDNESDAY NIGHT THEN REMAIN BELOW SCA INTO
SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING FROM 5 AM TO 8 PM EST WEDNESDAY FOR
MEZ011-015>017-029>032.
WINTER WEATHER ADVISORY FROM 5 AM TO 8 PM EST WEDNESDAY FOR
MEZ005-006-010.
MARINE...GALE WARNING FROM 7 AM WEDNESDAY TO 3 AM EST THURSDAY FOR
ANZ050>052.
&&
$$
NEAR TERM...FOSTER/HEWITT
SHORT TERM...BLOOMER
LONG TERM...BLOOMER
AVIATION...FOSTER/HEWITT
MARINE...FOSTER/HEWITT/BLOOMER
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1107 AM CST TUE NOV 22 2011
.AVIATION...18Z TAF. MORNING FOG HAS DISSIPATED AND CLEAR SKIES
ARE EXPECTED THROUGH THE REMAINDER OF THE TAF PERIOD. WINDS WILL
BE FAIRLY LIGHT FROM A WESTERLY DIRECTION.
&&
.UPDATE...VSBYS HAVE IMPROVED THIS MORNING AND HAVE REMOVED FOG
MENTION ACROSS OUR EASTERN ZONES. CLEAR/SUNNY SKIES ARE EXPECTED
THE REMAINDER OF THE DAY.
&&
.PREV DISCUSSION... /ISSUED 616 AM CST TUE NOV 22 2011/
UPDATE...JUST REFRESHED FIRST FEW HOURS OF FORECAST...MAINLY TO
DROP PRE-FIRST PERIOD FROM ZONE PRODUCT AND ALSO TO DRAG MENTION
OF PATCHY FOG AND PATCHY DENSE FOG FARTHER WEST. BASED ON LATEST
TRENDS FROM AUTOMATED OBS AND RUC LOW-LEVEL RELATIVE HUMIDITY
DATA...AT LEAST PATCHY FOG HAS DEVELOPED AS FAR WEST AS HIGHWAY
281 DURING THE PAST 1-2 HOURS...WITH KGRI BRIEFLY DOWN TO 1/2 MILE
AT 11Z. JUST TO THE EAST ALONG THE VERY BACK EDGE OF DEPARTING
CLOUD COVER...SITES SUCH AS AURORA AND YORK ARE DOWN IN THE 1/4 TO
1/2 MILE RANGE...BUT HAVE SHOWN SOME VARIABILITY. NOW THAT TEMPS
HAVE FALLEN BELOW FREEZING IN THE FOGGY AREAS...SLICK SPOTS ON
AREA ROADS ARE CERTAINLY NOT OUT OF THE QUESTION...BUT GIVEN THE
LOCALIZED NATURE OF ANY DENSE FOG WILL HOLD OFF ON AN ADVISORY
BUT LET THE MENTION IN THE HWO PRODUCT STAND. AS THE CLEARING LINE
HAS MARCHED EAST...EARLY MORNING LOW TEMPS HAVE DROPPED EVEN
FARTHER THAN THOUGHT A FEW HOURS AGO IN SOME SPOTS. WONDER IF THIS
COLD START COULD MAKE REACHING FORECAST AFTERNOON HIGHS A BIT
TOUGH IN PLACES...BUT WILL LET IT RIDE FOR NOW AS MANY AREAS
SHOULD STILL TOUCH/EXCEED THE 50 MARK. STILL LOOKS LIKE ANY
STRATUS/FOG SHOULD BE EAST OF THE CWA BY 15Z OR SO.
PREV DISCUSSION... /ISSUED 426 AM CST TUE NOV 22 2011/
SHORT TERM...THROUGH THURSDAY NIGHT. OTHER THAN SOME FOG IN THE
FAR EASTERN CWA THIS MORNING...NOT MUCH WEATHER OF CONSEQUENCE
DURING THE UPCOMING 72 HOURS...WHICH WILL BE SEASONABLY PLEASANT
BY LATE NOVEMBER STANDARDS.
STARTING OFF AT 10Z THIS MORNING...OBJECTIVE SURFACE ANALYSIS AND
AUTOMATED OBS REVEALED BROAD HIGH PRESSURE STRETCHED ACROSS
SOUTHERN NEB/NORTHERN KS...WITH BREEZES RANGING FROM CALM TO VERY
LIGHT WESTERLY. 11-3.9 MICRON SATELLITE IMAGERY SHOWS A FAIRLY
SHARP CUTOFF BETWEEN MOSTLY CLEAR SKIES ACROSS THE WESTERN 2/3 OF
THE CWA...AND CONSIDERABLE CLOUDS MAINLY OF THE MID/HIGH VARIETY
ACROSS THE EAST. HOWEVER...PER AUTOMATED OBS AND THE LATEST RUC
LOW LEVEL RELATIVE HUMIDITY PROGS...A CORRIDOR OF LOW STRATUS IS
BRUSHING MAINLY THE FAR EASTERN ROW OF COUNTIES IN THE CWA...WITH
LOW DEWPOINT DEPRESSIONS NEAR THE EDGE OF THIS STRATUS EVEN
RESULTING IN A NARROW CORRIDOR OF FOG...AT TIMES DENSE...NEAR THE
HIGHWAY 81 CORRIDOR AS EVIDENCED BY YORK OBS. RADAR WISE...ONLY A
FEW WEAK ECHOES...SPRINKLES AT BEST...HAVE RECENTLY EXITED THE
EXTREME SOUTHEAST CWA...WHILE A MUCH STEADIER LIGHT RAIN PERSISTS
ACROSS NORTHEAST KS/FAR SOUTHEAST NEB. IN THE MID/UPPER
LEVELS...10Z WATER VAPOR IMAGERY ALONG WITH SHORT TERM MODEL DATA
HIGHLIGHT THE PRIMARY FEATURE OF INTEREST AS A PROGRESSIVE OPEN
SHORTWAVE CENTERED OVER EASTERN KS AND STEADILY LIFTING EAST-
NORTHEAST.
AS FOR THE SYSTEM STARTING TO DEPART THE REGION...NEEDLESS TO SAY
SEVERAL 00Z/06 MODELS FROM 24 HOURS AGO ENDED UP BEING HORRIBLY
OVERDONE WITH COVERAGE OF PRECIPITATION ACROSS PARTS OF THE
CWA...ESPECIALLY THE NAM...AND AS IT TURNED OUT THE ONLY AREAS
THAT MAYBE PICKED UP A FEW HUNDREDTHS AT MOST WERE LIKELY CONFINED
TO PARTS OF JEWELL/MITCHELL COUNTIES KS...WITH NOTABLY HIGHER
AMOUNTS FOCUSING BARELY OUTSIDE THE CWA SUCH AS CONCORDIA WITH 0.20.
STILL...IT WAS A FAIRLY CLOSE CALL AT ONE POINT EARLIER IN THE
NIGHT WHETHER ANY OF THIS LIGHT PRECIPITATION WOULD
FREEZE...ALTHOUGH IT APPEARS TEMPS REMAINED A FEW DEGREES WARM
ENOUGH TO AVOID ISSUES. GIVEN THE MORE OPEN...PROGRESSIVE NATURE
OF THE SYSTEM...SKIES ACROSS THE MAJORITY OF THE CWA HAVE ALSO
CLEARED FASTER THAN ANTICIPATED 24 HOURS AGO...THUS WHY TEMPS HAVE
ALREADY FALLEN OFF INTO THE UPPER TEENS TO MID 20S IN MUCH OF THE
CWA...WHILE 30S ARE HANGING ON UNDER THE STRATUS IN THE FAR EAST.
OBVIOUSLY THE ONLY REAL CONCERN DURING THE NEXT 3-6 HOURS OR SO
INVOLVES THE CONTINUED FOG/LOW STRATUS PLAGUING FAR EASTERN AREAS.
WHILE SOME OF IT IS LIKELY DENSE IN LOCALIZED SPOTS...NO PLANS FOR
AN ADVISORY AT THIS TIME BUT HAVE MENTIONED IN THE HWO...AND
CANNOT RULE OUT A FEW SLICK SPOTS AS TEMPS EDGE BELOW FREEZING
DURING NEXT FEW HOURS. PER RUC RH PROGS AND LATEST GFS LAMP
GUIDANCE FOR YORK...STRATUS/FOG SHOULD ERODE EAST OUT OF THE CWA
BY MID MORNING AT THE LATEST. AS TEMPS CONTINUE TO COOL THIS
MORNING...CANNOT RULE OUT AT LEAST LIGHT FOG DEVELOPING BACK WEST
TOWARD THE HIGHWAY 281 AS WELL...BUT NOT ANTICIPATING ANYTHING
DENSE THAT FAR WEST.
ASSUMING THAT STRATUS VACATES THE CWA BY MID MORNING...SUNNY SKIES
WILL DOMINATE THE DAYTIME HOURS BEHIND THE DEPARTING
SHORTWAVE...WHICH WILL BE WELL OFF INTO THE EASTERN MIDWEST BY
SUNSET. WITH THE AID OF LIGHT WESTERLY DOWNSLOPE FLOW...A NICE
WARMUP IS IN STORE TODAY...AND KEPT HIGH TEMPS A TOUCH ABOVE THE
CONSENSUS OF MET/MAV GUIDANCE...AIMING FOR AROUND 50 FAR EAST...TO
MID 50S SOUTHWEST.
TONIGHT...LIGHT WESTERLY FLOW PERSISTS AT THE SURFACE...WITH DRY
NORTHWEST FLOW ALOFT. CHANGED INHERITED LOW TEMPS VERY
LITTLE...KEEPING THEM ON THE COLDER END OF GUIDANCE WITH MOST
SPOTS IN THE MID TO UPPER 20S. GIVEN RECENT LACK OF RAINFALL
ACROSS THE CWA AND FACT THAT BREEZES SHOULD AVERAGE AROUND
5KT...NOT EXPECTING ANY FOG ISSUES TONIGHT BUT SUPPOSE SOME LIGHT
DEVELOPMENT IS NOT OUT OF THE QUESTION.
CONDITIONS WILL REALLY START TURNING SEASONABLY PLEASANT FOR
WEDNESDAY AS MID LEVEL HEIGHTS RISE IN RESPONSE TO A BROAD RIDGE
AXIS ESTABLISHING ITSELF ACROSS THE CENTRAL CONUS. FAIRLY LIGHT
WESTERLY BREEZES WILL DOMINATE THE DAYTIME HOURS. DESPITE FAIRLY
SHALLOW MIXING TO ONLY AROUND 900MB...STILL FEEL THAT MOST OF THE
CWA SHOULD BRUSH THE 60 MARK FOR HIGHS...WITH MID 60S FOR MOST KS
ZONES.
WED NIGHT...STEADY LIGHT SOUTHERLY BREEZES WILL BE IN PLACE AT THE
SURFACE AS THE FLOW ALOFT STARTS TO TURN SOUTHWESTERLY IN ADVANCE
OF THE NEXT SYSTEM ALONG THE WEST COAST. ALTHOUGH THESE BREEZES
WILL HELP KEEP LOW TEMPS A BIT WARMER THAN TONIGHT...FELT THAT
RECENT TRENDS OF ENDING UP TOO WARM WITH LOWS UNDER CLEAR SKIES
JUSTIFIED KNOCKING 2-3 DEGREES OFF PREVIOUS FORECAST...NOW
BRINGING MOST AREAS DOWN INTO THE LOW 30S.
THANKSGIVING DAY...DRY AND AT LEAST MOSTLY SUNNY CONDITIONS
PERSIST...ALTHOUGH SOUTH WINDS WILL INCREASE A BIT INTO THE
SUSTAINED 10-20 MPH RANGE AS A HIGH PLAINS LEE TROUGH DEEPENS A
BIT. THE HIGHEST WINDS IN THIS RANGE WILL FOCUS ACROSS THE
SOUTHEAST 1/2 OF THE CWA. TEMP WISE...ALTHOUGH MIXING WILL REMAIN
SOMEWHAT SHALLOW...SEE NO REASON WHY SOUTHERLY FLOW WON/T BOOST
HIGHS ANOTHER NOTCH...AND ACTUALLY RAISED 2-4 DEGREES OVER
PREVIOUS FORECAST PUTTING MOST OF THE CWA WELL INTO THE 60S...AND
EVEN UPPER 60S IN PARTS OF KS. IF THESE NUMBERS HOLD...THIS LOOKS
TO BE THE WARMEST THANKSGIVING DAY IN THE TRI-CITIES SINCE 2006.
THURS NIGHT...KEPT DRY...BUT INCREASING HIGH LEVEL CLOUDS WILL
ACCOMPANY THE LEADING EDGE OF SHORTWAVE ENERGY EJECTING OUT OF
THE WEST. MODEST INCREASE IN LOW LEVEL MOISTURE...SOUTHERLY
BREEZES AND INCREASING CLOUDS SHOULD MAKE THIS THE OVERALL WARMEST
NIGHT OF THE FORECAST PERIOD...WITH LOWS HOLDING UP IN THE
MID/UPPER 30S IN MOST OF THE CWA...AND EVEN LOW 40S SOUTHEAST.
LONG TERM...FRIDAY THROUGH MONDAY. GENERALLY USED AN INTERMEDIATE
COMBINATION OF GUIDANCE SPREADS FOR THE LONG TERM FORECAST. MODELS
ARE STILL INDICATING A SHORTWAVE TROUGH TO SWING THROUGH FROM THE
NORTHWEST FOR FRIDAY/FRIDAY NIGHT. WITH DRY AIR IN PLACE...THE
BEST BET FOR ANY PRECIPITATION WILL BE IN OUR EASTERN CWA WHERE
WHERE SOME LOWER LEVEL GULF INFLOW COULD SPREAD INTO THAT AREA
WITH THE AID OF SOME BACKING WIND AS THE SURFACE COLD FRONT
APPROACHES. THE TRI-CITIES MAY BE ON THE FAR WESTERN EDGE OF ANY
PRECIPITATION THAT DEVELOPS BUT MODELS ARE TRENDING A BIT FARTHER
WEST. WHERE MODELS HAD INDICATED A CLOSED AND EVENTUALLY CUTOFF
LOW OVER THE SOUTHWEST UNITED STATES/MEXICO FOR FRIDAY FROM MODEL
RUNS LAST NIGHT...THIS CUTOFF HAS BEEN PUSHED BACK TO SATURDAY
NIGHT ON THE ECMWF AND DOES NOT OCCUR AT ALL ON THE GFS AS THE
SOUTHERN AND NORTHERN STREAMS PHASE WAVES FOR FRIDAY. MODELS STILL
MOVE THE WAVE THROUGH QUICKLY WITH RIDGING FOLLOWING...KEEPING A
DRY FORECAST THROUGH THE WEEKEND INTO MONDAY AS THE WAVE DIGS TO
THE EAST OF THE MISSOURI VALLEY.
SATURDAY IS STILL LOOKING QUITE BREEZY/WINDY AS SURFACE HIGH
PRESSURE BUILDS IN. MODELS DIFFER BY VARYING DEGREES ON
TEMPERATURES...BUT GENERALLY LOOK SEASONABLY COOL.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
616 AM CST TUE NOV 22 2011
.UPDATE...JUST REFRESHED FIRST FEW HOURS OF FORECAST...MAINLY TO
DROP PRE-FIRST PERIOD FROM ZONE PRODUCT AND ALSO TO DRAG MENTION
OF PATCHY FOG AND PATCHY DENSE FOG FARTHER WEST. BASED ON LATEST
TRENDS FROM AUTOMATED OBS AND RUC LOW-LEVEL RELATIVE HUMIDITY
DATA...AT LEAST PATCHY FOG HAS DEVELOPED AS FAR WEST AS HIGHWAY
281 DURING THE PAST 1-2 HOURS...WITH KGRI BRIEFLY DOWN TO 1/2 MILE
AT 11Z. JUST TO THE EAST ALONG THE VERY BACK EDGE OF DEPARTING
CLOUD COVER...SITES SUCH AS AURORA AND YORK ARE DOWN IN THE 1/4 TO
1/2 MILE RANGE...BUT HAVE SHOWN SOME VARIABILITY. NOW THAT TEMPS
HAVE FALLEN BELOW FREEZING IN THE FOGGY AREAS...SLICK SPOTS ON
AREA ROADS ARE CERTAINLY NOT OUT OF THE QUESTION...BUT GIVEN THE
LOCALIZED NATURE OF ANY DENSE FOG WILL HOLD OFF ON AN ADVISORY
BUT LET THE MENTION IN THE HWO PRODUCT STAND. AS THE CLEARING LINE
HAS MARCHED EAST...EARLY MORNING LOW TEMPS HAVE DROPPED EVEN
FARTHER THAN THOUGHT A FEW HOURS AGO IN SOME SPOTS. WONDER IF THIS
COLD START COULD MAKE REACHING FORECAST AFTERNOON HIGHS A BIT
TOUGH IN PLACES...BUT WILL LET IT RIDE FOR NOW AS MANY AREAS
SHOULD STILL TOUCH/EXCEED THE 50 MARK. STILL LOOKS LIKE ANY
STRATUS/FOG SHOULD BE EAST OF THE CWA BY 15Z OR SO.
&&
.PREV DISCUSSION... /ISSUED 541 AM CST TUE NOV 22 2011/
AVIATION...12Z KGRI TAF. THE FIRST HOUR OR SO OF THE FORECAST
WILL BE TRICKY AS FAR AS VISIBILITY IS CONCERNED. THE EDGE OF THE
STRATUS IS JUST TO THE EAST AND IS MOVING EAST...SO THE BEST GUESS
IS IFR OR POSSIBLY MVFR FOR THE FIRST HOUR...THEN VISIBILITY
SHOULD IMPROVE QUICKLY. VFR CONDITIONS WITH LIGHT WIND ARE
EXPECTED FOR THE REST OF THE FORECAST.
PREV DISCUSSION... /ISSUED 426 AM CST TUE NOV 22 2011/
SHORT TERM...THROUGH THURSDAY NIGHT. OTHER THAN SOME FOG IN THE
FAR EASTERN CWA THIS MORNING...NOT MUCH WEATHER OF CONSEQUENCE
DURING THE UPCOMING 72 HOURS...WHICH WILL BE SEASONABLY PLEASANT
BY LATE NOVEMBER STANDARDS.
STARTING OFF AT 10Z THIS MORNING...OBJECTIVE SURFACE ANALYSIS AND
AUTOMATED OBS REVEALED BROAD HIGH PRESSURE STRETCHED ACROSS
SOUTHERN NEB/NORTHERN KS...WITH BREEZES RANGING FROM CALM TO VERY
LIGHT WESTERLY. 11-3.9 MICRON SATELLITE IMAGERY SHOWS A FAIRLY
SHARP CUTOFF BETWEEN MOSTLY CLEAR SKIES ACROSS THE WESTERN 2/3 OF
THE CWA...AND CONSIDERABLE CLOUDS MAINLY OF THE MID/HIGH VARIETY
ACROSS THE EAST. HOWEVER...PER AUTOMATED OBS AND THE LATEST RUC
LOW LEVEL RELATIVE HUMIDITY PROGS...A CORRIDOR OF LOW STRATUS IS
BRUSHING MAINLY THE FAR EASTERN ROW OF COUNTIES IN THE CWA...WITH
LOW DEWPOINT DEPRESSIONS NEAR THE EDGE OF THIS STRATUS EVEN
RESULTING IN A NARROW CORRIDOR OF FOG...AT TIMES DENSE...NEAR THE
HIGHWAY 81 CORRIDOR AS EVIDENCED BY YORK OBS. RADAR WISE...ONLY A
FEW WEAK ECHOES...SPRINKLES AT BEST...HAVE RECENTLY EXITED THE
EXTREME SOUTHEAST CWA...WHILE A MUCH STEADIER LIGHT RAIN PERSISTS
ACROSS NORTHEAST KS/FAR SOUTHEAST NEB. IN THE MID/UPPER
LEVELS...10Z WATER VAPOR IMAGERY ALONG WITH SHORT TERM MODEL DATA
HIGHLIGHT THE PRIMARY FEATURE OF INTEREST AS A PROGRESSIVE OPEN
SHORTWAVE CENTERED OVER EASTERN KS AND STEADILY LIFTING EAST-
NORTHEAST.
AS FOR THE SYSTEM STARTING TO DEPART THE REGION...NEEDLESS TO SAY
SEVERAL 00Z/06 MODELS FROM 24 HOURS AGO ENDED UP BEING HORRIBLY
OVERDONE WITH COVERAGE OF PRECIPITATION ACROSS PARTS OF THE
CWA...ESPECIALLY THE NAM...AND AS IT TURNED OUT THE ONLY AREAS
THAT MAYBE PICKED UP A FEW HUNDREDTHS AT MOST WERE LIKELY CONFINED
TO PARTS OF JEWELL/MITCHELL COUNTIES KS...WITH NOTABLY HIGHER
AMOUNTS FOCUSING BARELY OUTSIDE THE CWA SUCH AS CONCORDIA WITH 0.20.
STILL...IT WAS A FAIRLY CLOSE CALL AT ONE POINT EARLIER IN THE
NIGHT WHETHER ANY OF THIS LIGHT PRECIPITATION WOULD
FREEZE...ALTHOUGH IT APPEARS TEMPS REMAINED A FEW DEGREES WARM
ENOUGH TO AVOID ISSUES. GIVEN THE MORE OPEN...PROGRESSIVE NATURE
OF THE SYSTEM...SKIES ACROSS THE MAJORITY OF THE CWA HAVE ALSO
CLEARED FASTER THAN ANTICIPATED 24 HOURS AGO...THUS WHY TEMPS HAVE
ALREADY FALLEN OFF INTO THE UPPER TEENS TO MID 20S IN MUCH OF THE
CWA...WHILE 30S ARE HANGING ON UNDER THE STRATUS IN THE FAR EAST.
OBVIOUSLY THE ONLY REAL CONCERN DURING THE NEXT 3-6 HOURS OR SO
INVOLVES THE CONTINUED FOG/LOW STRATUS PLAGUING FAR EASTERN AREAS.
WHILE SOME OF IT IS LIKELY DENSE IN LOCALIZED SPOTS...NO PLANS FOR
AN ADVISORY AT THIS TIME BUT HAVE MENTIONED IN THE HWO...AND
CANNOT RULE OUT A FEW SLICK SPOTS AS TEMPS EDGE BELOW FREEZING
DURING NEXT FEW HOURS. PER RUC RH PROGS AND LATEST GFS LAMP
GUIDANCE FOR YORK...STRATUS/FOG SHOULD ERODE EAST OUT OF THE CWA
BY MID MORNING AT THE LATEST. AS TEMPS CONTINUE TO COOL THIS
MORNING...CANNOT RULE OUT AT LEAST LIGHT FOG DEVELOPING BACK WEST
TOWARD THE HIGHWAY 281 AS WELL...BUT NOT ANTICIPATING ANYTHING
DENSE THAT FAR WEST.
ASSUMING THAT STRATUS VACATES THE CWA BY MID MORNING...SUNNY SKIES
WILL DOMINATE THE DAYTIME HOURS BEHIND THE DEPARTING
SHORTWAVE...WHICH WILL BE WELL OFF INTO THE EASTERN MIDWEST BY
SUNSET. WITH THE AID OF LIGHT WESTERLY DOWNSLOPE FLOW...A NICE
WARMUP IS IN STORE TODAY...AND KEPT HIGH TEMPS A TOUCH ABOVE THE
CONSENSUS OF MET/MAV GUIDANCE...AIMING FOR AROUND 50 FAR EAST...TO
MID 50S SOUTHWEST.
TONIGHT...LIGHT WESTERLY FLOW PERSISTS AT THE SURFACE...WITH DRY
NORTHWEST FLOW ALOFT. CHANGED INHERITED LOW TEMPS VERY
LITTLE...KEEPING THEM ON THE COLDER END OF GUIDANCE WITH MOST
SPOTS IN THE MID TO UPPER 20S. GIVEN RECENT LACK OF RAINFALL
ACROSS THE CWA AND FACT THAT BREEZES SHOULD AVERAGE AROUND
5KT...NOT EXPECTING ANY FOG ISSUES TONIGHT BUT SUPPOSE SOME LIGHT
DEVELOPMENT IS NOT OUT OF THE QUESTION.
CONDITIONS WILL REALLY START TURNING SEASONABLY PLEASANT FOR
WEDNESDAY AS MID LEVEL HEIGHTS RISE IN RESPONSE TO A BROAD RIDGE
AXIS ESTABLISHING ITSELF ACROSS THE CENTRAL CONUS. FAIRLY LIGHT
WESTERLY BREEZES WILL DOMINATE THE DAYTIME HOURS. DESPITE FAIRLY
SHALLOW MIXING TO ONLY AROUND 900MB...STILL FEEL THAT MOST OF THE
CWA SHOULD BRUSH THE 60 MARK FOR HIGHS...WITH MID 60S FOR MOST KS
ZONES.
WED NIGHT...STEADY LIGHT SOUTHERLY BREEZES WILL BE IN PLACE AT THE
SURFACE AS THE FLOW ALOFT STARTS TO TURN SOUTHWESTERLY IN ADVANCE
OF THE NEXT SYSTEM ALONG THE WEST COAST. ALTHOUGH THESE BREEZES
WILL HELP KEEP LOW TEMPS A BIT WARMER THAN TONIGHT...FELT THAT
RECENT TRENDS OF ENDING UP TOO WARM WITH LOWS UNDER CLEAR SKIES
JUSTIFIED KNOCKING 2-3 DEGREES OFF PREVIOUS FORECAST...NOW
BRINGING MOST AREAS DOWN INTO THE LOW 30S.
THANKSGIVING DAY...DRY AND AT LEAST MOSTLY SUNNY CONDITIONS
PERSIST...ALTHOUGH SOUTH WINDS WILL INCREASE A BIT INTO THE
SUSTAINED 10-20 MPH RANGE AS A HIGH PLAINS LEE TROUGH DEEPENS A
BIT. THE HIGHEST WINDS IN THIS RANGE WILL FOCUS ACROSS THE
SOUTHEAST 1/2 OF THE CWA. TEMP WISE...ALTHOUGH MIXING WILL REMAIN
SOMEWHAT SHALLOW...SEE NO REASON WHY SOUTHERLY FLOW WON/T BOOST
HIGHS ANOTHER NOTCH...AND ACTUALLY RAISED 2-4 DEGREES OVER
PREVIOUS FORECAST PUTTING MOST OF THE CWA WELL INTO THE 60S...AND
EVEN UPPER 60S IN PARTS OF KS. IF THESE NUMBERS HOLD...THIS LOOKS
TO BE THE WARMEST THANKSGIVING DAY IN THE TRI-CITIES SINCE 2006.
THURS NIGHT...KEPT DRY...BUT INCREASING HIGH LEVEL CLOUDS WILL
ACCOMPANY THE LEADING EDGE OF SHORTWAVE ENERGY EJECTING OUT OF
THE WEST. MODEST INCREASE IN LOW LEVEL MOISTURE...SOUTHERLY
BREEZES AND INCREASING CLOUDS SHOULD MAKE THIS THE OVERALL WARMEST
NIGHT OF THE FORECAST PERIOD...WITH LOWS HOLDING UP IN THE
MID/UPPER 30S IN MOST OF THE CWA...AND EVEN LOW 40S SOUTHEAST.
LONG TERM...FRIDAY THROUGH MONDAY. GENERALLY USED AN INTERMEDIATE
COMBINATION OF GUIDANCE SPREADS FOR THE LONG TERM FORECAST. MODELS
ARE STILL INDICATING A SHORTWAVE TROUGH TO SWING THROUGH FROM THE
NORTHWEST FOR FRIDAY/FRIDAY NIGHT. WITH DRY AIR IN PLACE...THE
BEST BET FOR ANY PRECIPITATION WILL BE IN OUR EASTERN CWA WHERE
WHERE SOME LOWER LEVEL GULF INFLOW COULD SPREAD INTO THAT AREA
WITH THE AID OF SOME BACKING WIND AS THE SURFACE COLD FRONT
APPROACHES. THE TRI-CITIES MAY BE ON THE FAR WESTERN EDGE OF ANY
PRECIPITATION THAT DEVELOPS BUT MODELS ARE TRENDING A BIT FARTHER
WEST. WHERE MODELS HAD INDICATED A CLOSED AND EVENTUALLY CUTOFF
LOW OVER THE SOUTHWEST UNITED STATES/MEXICO FOR FRIDAY FROM MODEL
RUNS LAST NIGHT...THIS CUTOFF HAS BEEN PUSHED BACK TO SATURDAY
NIGHT ON THE ECMWF AND DOES NOT OCCUR AT ALL ON THE GFS AS THE
SOUTHERN AND NORTHERN STREAMS PHASE WAVES FOR FRIDAY. MODELS STILL
MOVE THE WAVE THROUGH QUICKLY WITH RIDGING FOLLOWING...KEEPING A
DRY FORECAST THROUGH THE WEEKEND INTO MONDAY AS THE WAVE DIGS TO
THE EAST OF THE MISSOURI VALLEY.
SATURDAY IS STILL LOOKING QUITE BREEZY/WINDY AS SURFACE HIGH
PRESSURE BUILDS IN. MODELS DIFFER BY VARYING DEGREES ON
TEMPERATURES...BUT GENERALLY LOOK SEASONABLY COOL.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE/SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
541 AM CST TUE NOV 22 2011
.AVIATION...12Z KGRI TAF. THE FIRST HOUR OR SO OF THE FORECAST
WILL BE TRICKY AS FAR AS VISIBILITY IS CONCERNED. THE EDGE OF THE
STRATUS IS JUST TO THE EAST AND IS MOVING EAST...SO THE BEST GUESS
IS IFR OR POSSIBLY MVFR FOR THE FIRST HOUR...THEN VISIBILITY
SHOULD IMPROVE QUICKLY. VFR CONDITIONS WITH LIGHT WIND ARE
EXPECTED FOR THE REST OF THE FORECAST.
&&
.PREV DISCUSSION... /ISSUED 426 AM CST TUE NOV 22 2011/
SHORT TERM...THROUGH THURSDAY NIGHT. OTHER THAN SOME FOG IN THE
FAR EASTERN CWA THIS MORNING...NOT MUCH WEATHER OF CONSEQUENCE
DURING THE UPCOMING 72 HOURS...WHICH WILL BE SEASONABLY PLEASANT
BY LATE NOVEMBER STANDARDS.
STARTING OFF AT 10Z THIS MORNING...OBJECTIVE SURFACE ANALYSIS AND
AUTOMATED OBS REVEALED BROAD HIGH PRESSURE STRETCHED ACROSS
SOUTHERN NEB/NORTHERN KS...WITH BREEZES RANGING FROM CALM TO VERY
LIGHT WESTERLY. 11-3.9 MICRON SATELLITE IMAGERY SHOWS A FAIRLY
SHARP CUTOFF BETWEEN MOSTLY CLEAR SKIES ACROSS THE WESTERN 2/3 OF
THE CWA...AND CONSIDERABLE CLOUDS MAINLY OF THE MID/HIGH VARIETY
ACROSS THE EAST. HOWEVER...PER AUTOMATED OBS AND THE LATEST RUC
LOW LEVEL RELATIVE HUMIDITY PROGS...A CORRIDOR OF LOW STRATUS IS
BRUSHING MAINLY THE FAR EASTERN ROW OF COUNTIES IN THE CWA...WITH
LOW DEWPOINT DEPRESSIONS NEAR THE EDGE OF THIS STRATUS EVEN
RESULTING IN A NARROW CORRIDOR OF FOG...AT TIMES DENSE...NEAR THE
HIGHWAY 81 CORRIDOR AS EVIDENCED BY YORK OBS. RADAR WISE...ONLY A
FEW WEAK ECHOES...SPRINKLES AT BEST...HAVE RECENTLY EXITED THE
EXTREME SOUTHEAST CWA...WHILE A MUCH STEADIER LIGHT RAIN PERSISTS
ACROSS NORTHEAST KS/FAR SOUTHEAST NEB. IN THE MID/UPPER
LEVELS...10Z WATER VAPOR IMAGERY ALONG WITH SHORT TERM MODEL DATA
HIGHLIGHT THE PRIMARY FEATURE OF INTEREST AS A PROGRESSIVE OPEN
SHORTWAVE CENTERED OVER EASTERN KS AND STEADILY LIFTING EAST-
NORTHEAST.
AS FOR THE SYSTEM STARTING TO DEPART THE REGION...NEEDLESS TO SAY
SEVERAL 00Z/06 MODELS FROM 24 HOURS AGO ENDED UP BEING HORRIBLY
OVERDONE WITH COVERAGE OF PRECIPITATION ACROSS PARTS OF THE
CWA...ESPECIALLY THE NAM...AND AS IT TURNED OUT THE ONLY AREAS
THAT MAYBE PICKED UP A FEW HUNDREDTHS AT MOST WERE LIKELY CONFINED
TO PARTS OF JEWELL/MITCHELL COUNTIES KS...WITH NOTABLY HIGHER
AMOUNTS FOCUSING BARELY OUTSIDE THE CWA SUCH AS CONCORDIA WITH 0.20.
STILL...IT WAS A FAIRLY CLOSE CALL AT ONE POINT EARLIER IN THE
NIGHT WHETHER ANY OF THIS LIGHT PRECIPITATION WOULD
FREEZE...ALTHOUGH IT APPEARS TEMPS REMAINED A FEW DEGREES WARM
ENOUGH TO AVOID ISSUES. GIVEN THE MORE OPEN...PROGRESSIVE NATURE
OF THE SYSTEM...SKIES ACROSS THE MAJORITY OF THE CWA HAVE ALSO
CLEARED FASTER THAN ANTICIPATED 24 HOURS AGO...THUS WHY TEMPS HAVE
ALREADY FALLEN OFF INTO THE UPPER TEENS TO MID 20S IN MUCH OF THE
CWA...WHILE 30S ARE HANGING ON UNDER THE STRATUS IN THE FAR EAST.
OBVIOUSLY THE ONLY REAL CONCERN DURING THE NEXT 3-6 HOURS OR SO
INVOLVES THE CONTINUED FOG/LOW STRATUS PLAGUING FAR EASTERN AREAS.
WHILE SOME OF IT IS LIKELY DENSE IN LOCALIZED SPOTS...NO PLANS FOR
AN ADVISORY AT THIS TIME BUT HAVE MENTIONED IN THE HWO...AND
CANNOT RULE OUT A FEW SLICK SPOTS AS TEMPS EDGE BELOW FREEZING
DURING NEXT FEW HOURS. PER RUC RH PROGS AND LATEST GFS LAMP
GUIDANCE FOR YORK...STRATUS/FOG SHOULD ERODE EAST OUT OF THE CWA
BY MID MORNING AT THE LATEST. AS TEMPS CONTINUE TO COOL THIS
MORNING...CANNOT RULE OUT AT LEAST LIGHT FOG DEVELOPING BACK WEST
TOWARD THE HIGHWAY 281 AS WELL...BUT NOT ANTICIPATING ANYTHING
DENSE THAT FAR WEST.
ASSUMING THAT STRATUS VACATES THE CWA BY MID MORNING...SUNNY SKIES
WILL DOMINATE THE DAYTIME HOURS BEHIND THE DEPARTING
SHORTWAVE...WHICH WILL BE WELL OFF INTO THE EASTERN MIDWEST BY
SUNSET. WITH THE AID OF LIGHT WESTERLY DOWNSLOPE FLOW...A NICE
WARMUP IS IN STORE TODAY...AND KEPT HIGH TEMPS A TOUCH ABOVE THE
CONSENSUS OF MET/MAV GUIDANCE...AIMING FOR AROUND 50 FAR EAST...TO
MID 50S SOUTHWEST.
TONIGHT...LIGHT WESTERLY FLOW PERSISTS AT THE SURFACE...WITH DRY
NORTHWEST FLOW ALOFT. CHANGED INHERITED LOW TEMPS VERY
LITTLE...KEEPING THEM ON THE COLDER END OF GUIDANCE WITH MOST
SPOTS IN THE MID TO UPPER 20S. GIVEN RECENT LACK OF RAINFALL
ACROSS THE CWA AND FACT THAT BREEZES SHOULD AVERAGE AROUND
5KT...NOT EXPECTING ANY FOG ISSUES TONIGHT BUT SUPPOSE SOME LIGHT
DEVELOPMENT IS NOT OUT OF THE QUESTION.
CONDITIONS WILL REALLY START TURNING SEASONABLY PLEASANT FOR
WEDNESDAY AS MID LEVEL HEIGHTS RISE IN RESPONSE TO A BROAD RIDGE
AXIS ESTABLISHING ITSELF ACROSS THE CENTRAL CONUS. FAIRLY LIGHT
WESTERLY BREEZES WILL DOMINATE THE DAYTIME HOURS. DESPITE FAIRLY
SHALLOW MIXING TO ONLY AROUND 900MB...STILL FEEL THAT MOST OF THE
CWA SHOULD BRUSH THE 60 MARK FOR HIGHS...WITH MID 60S FOR MOST KS
ZONES.
WED NIGHT...STEADY LIGHT SOUTHERLY BREEZES WILL BE IN PLACE AT THE
SURFACE AS THE FLOW ALOFT STARTS TO TURN SOUTHWESTERLY IN ADVANCE
OF THE NEXT SYSTEM ALONG THE WEST COAST. ALTHOUGH THESE BREEZES
WILL HELP KEEP LOW TEMPS A BIT WARMER THAN TONIGHT...FELT THAT
RECENT TRENDS OF ENDING UP TOO WARM WITH LOWS UNDER CLEAR SKIES
JUSTIFIED KNOCKING 2-3 DEGREES OFF PREVIOUS FORECAST...NOW
BRINGING MOST AREAS DOWN INTO THE LOW 30S.
THANKSGIVING DAY...DRY AND AT LEAST MOSTLY SUNNY CONDITIONS
PERSIST...ALTHOUGH SOUTH WINDS WILL INCREASE A BIT INTO THE
SUSTAINED 10-20 MPH RANGE AS A HIGH PLAINS LEE TROUGH DEEPENS A
BIT. THE HIGHEST WINDS IN THIS RANGE WILL FOCUS ACROSS THE
SOUTHEAST 1/2 OF THE CWA. TEMP WISE...ALTHOUGH MIXING WILL REMAIN
SOMEWHAT SHALLOW...SEE NO REASON WHY SOUTHERLY FLOW WON/T BOOST
HIGHS ANOTHER NOTCH...AND ACTUALLY RAISED 2-4 DEGREES OVER
PREVIOUS FORECAST PUTTING MOST OF THE CWA WELL INTO THE 60S...AND
EVEN UPPER 60S IN PARTS OF KS. IF THESE NUMBERS HOLD...THIS LOOKS
TO BE THE WARMEST THANKSGIVING DAY IN THE TRI-CITIES SINCE 2006.
THURS NIGHT...KEPT DRY...BUT INCREASING HIGH LEVEL CLOUDS WILL
ACCOMPANY THE LEADING EDGE OF SHORTWAVE ENERGY EJECTING OUT OF
THE WEST. MODEST INCREASE IN LOW LEVEL MOISTURE...SOUTHERLY
BREEZES AND INCREASING CLOUDS SHOULD MAKE THIS THE OVERALL WARMEST
NIGHT OF THE FORECAST PERIOD...WITH LOWS HOLDING UP IN THE
MID/UPPER 30S IN MOST OF THE CWA...AND EVEN LOW 40S SOUTHEAST.
LONG TERM...FRIDAY THROUGH MONDAY. GENERALLY USED AN INTERMEDIATE
COMBINATION OF GUIDANCE SPREADS FOR THE LONG TERM FORECAST. MODELS
ARE STILL INDICATING A SHORTWAVE TROUGH TO SWING THROUGH FROM THE
NORTHWEST FOR FRIDAY/FRIDAY NIGHT. WITH DRY AIR IN PLACE...THE
BEST BET FOR ANY PRECIPITATION WILL BE IN OUR EASTERN CWA WHERE
WHERE SOME LOWER LEVEL GULF INFLOW COULD SPREAD INTO THAT AREA
WITH THE AID OF SOME BACKING WIND AS THE SURFACE COLD FRONT
APPROACHES. THE TRI-CITIES MAY BE ON THE FAR WESTERN EDGE OF ANY
PRECIPITATION THAT DEVELOPS BUT MODELS ARE TRENDING A BIT FARTHER
WEST. WHERE MODELS HAD INDICATED A CLOSED AND EVENTUALLY CUTOFF
LOW OVER THE SOUTHWEST UNITED STATES/MEXICO FOR FRIDAY FROM MODEL
RUNS LAST NIGHT...THIS CUTOFF HAS BEEN PUSHED BACK TO SATURDAY
NIGHT ON THE ECMWF AND DOES NOT OCCUR AT ALL ON THE GFS AS THE
SOUTHERN AND NORTHERN STREAMS PHASE WAVES FOR FRIDAY. MODELS STILL
MOVE THE WAVE THROUGH QUICKLY WITH RIDGING FOLLOWING...KEEPING A
DRY FORECAST THROUGH THE WEEKEND INTO MONDAY AS THE WAVE DIGS TO
THE EAST OF THE MISSOURI VALLEY.
SATURDAY IS STILL LOOKING QUITE BREEZY/WINDY AS SURFACE HIGH
PRESSURE BUILDS IN. MODELS DIFFER BY VARYING DEGREES ON
TEMPERATURES...BUT GENERALLY LOOK SEASONABLY COOL.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
426 AM CST TUE NOV 22 2011
.SHORT TERM...THROUGH THURSDAY NIGHT. OTHER THAN SOME FOG IN THE
FAR EASTERN CWA THIS MORNING...NOT MUCH WEATHER OF CONSEQUENCE
DURING THE UPCOMING 72 HOURS...WHICH WILL BE SEASONABLY PLEASANT
BY LATE NOVEMBER STANDARDS.
STARTING OFF AT 10Z THIS MORNING...OBJECTIVE SURFACE ANALYSIS AND
AUTOMATED OBS REVEALED BROAD HIGH PRESSURE STRETCHED ACROSS
SOUTHERN NEB/NORTHERN KS...WITH BREEZES RANGING FROM CALM TO VERY
LIGHT WESTERLY. 11-3.9 MICRON SATELLITE IMAGERY SHOWS A FAIRLY
SHARP CUTOFF BETWEEN MOSTLY CLEAR SKIES ACROSS THE WESTERN 2/3 OF
THE CWA...AND CONSIDERABLE CLOUDS MAINLY OF THE MID/HIGH VARIETY
ACROSS THE EAST. HOWEVER...PER AUTOMATED OBS AND THE LATEST RUC
LOW LEVEL RELATIVE HUMIDITY PROGS...A CORRIDOR OF LOW STRATUS IS
BRUSHING MAINLY THE FAR EASTERN ROW OF COUNTIES IN THE CWA...WITH
LOW DEWPOINT DEPRESSIONS NEAR THE EDGE OF THIS STRATUS EVEN
RESULTING IN A NARROW CORRIDOR OF FOG...AT TIMES DENSE...NEAR THE
HIGHWAY 81 CORRIDOR AS EVIDENCED BY YORK OBS. RADAR WISE...ONLY A
FEW WEAK ECHOES...SPRINKLES AT BEST...HAVE RECENTLY EXITED THE
EXTREME SOUTHEAST CWA...WHILE A MUCH STEADIER LIGHT RAIN PERSISTS
ACROSS NORTHEAST KS/FAR SOUTHEAST NEB. IN THE MID/UPPER
LEVELS...10Z WATER VAPOR IMAGERY ALONG WITH SHORT TERM MODEL DATA
HIGHLIGHT THE PRIMARY FEATURE OF INTEREST AS A PROGRESSIVE OPEN
SHORTWAVE CENTERED OVER EASTERN KS AND STEADILY LIFTING EAST-
NORTHEAST.
AS FOR THE SYSTEM STARTING TO DEPART THE REGION...NEEDLESS TO SAY
SEVERAL 00Z/06 MODELS FROM 24 HOURS AGO ENDED UP BEING HORRIBLY
OVERDONE WITH COVERAGE OF PRECIPITATION ACROSS PARTS OF THE
CWA...ESPECIALLY THE NAM...AND AS IT TURNED OUT THE ONLY AREAS
THAT MAYBE PICKED UP A FEW HUNDREDTHS AT MOST WERE LIKELY CONFINED
TO PARTS OF JEWELL/MITCHELL COUNTIES KS...WITH NOTABLY HIGHER
AMOUNTS FOCUSING BARELY OUTSIDE THE CWA SUCH AS CONCORDIA WITH 0.20.
STILL...IT WAS A FAIRLY CLOSE CALL AT ONE POINT EARLIER IN THE
NIGHT WHETHER ANY OF THIS LIGHT PRECIPITATION WOULD
FREEZE...ALTHOUGH IT APPEARS TEMPS REMAINED A FEW DEGREES WARM
ENOUGH TO AVOID ISSUES. GIVEN THE MORE OPEN...PROGRESSIVE NATURE
OF THE SYSTEM...SKIES ACROSS THE MAJORITY OF THE CWA HAVE ALSO
CLEARED FASTER THAN ANTICIPATED 24 HOURS AGO...THUS WHY TEMPS HAVE
ALREADY FALLEN OFF INTO THE UPPER TEENS TO MID 20S IN MUCH OF THE
CWA...WHILE 30S ARE HANGING ON UNDER THE STRATUS IN THE FAR EAST.
OBVIOUSLY THE ONLY REAL CONCERN DURING THE NEXT 3-6 HOURS OR SO
INVOLVES THE CONTINUED FOG/LOW STRATUS PLAGUING FAR EASTERN AREAS.
WHILE SOME OF IT IS LIKELY DENSE IN LOCALIZED SPOTS...NO PLANS FOR
AN ADVISORY AT THIS TIME BUT HAVE MENTIONED IN THE HWO...AND
CANNOT RULE OUT A FEW SLICK SPOTS AS TEMPS EDGE BELOW FREEZING
DURING NEXT FEW HOURS. PER RUC RH PROGS AND LATEST GFS LAMP
GUIDANCE FOR YORK...STRATUS/FOG SHOULD ERODE EAST OUT OF THE CWA
BY MID MORNING AT THE LATEST. AS TEMPS CONTINUE TO COOL THIS
MORNING...CANNOT RULE OUT AT LEAST LIGHT FOG DEVELOPING BACK WEST
TOWARD THE HIGHWAY 281 AS WELL...BUT NOT ANTICIPATING ANYTHING
DENSE THAT FAR WEST.
ASSUMING THAT STRATUS VACATES THE CWA BY MID MORNING...SUNNY SKIES
WILL DOMINATE THE DAYTIME HOURS BEHIND THE DEPARTING
SHORTWAVE...WHICH WILL BE WELL OFF INTO THE EASTERN MIDWEST BY
SUNSET. WITH THE AID OF LIGHT WESTERLY DOWNSLOPE FLOW...A NICE
WARMUP IS IN STORE TODAY...AND KEPT HIGH TEMPS A TOUCH ABOVE THE
CONSENSUS OF MET/MAV GUIDANCE...AIMING FOR AROUND 50 FAR EAST...TO
MID 50S SOUTHWEST.
TONIGHT...LIGHT WESTERLY FLOW PERSISTS AT THE SURFACE...WITH DRY
NORTHWEST FLOW ALOFT. CHANGED INHERITED LOW TEMPS VERY
LITTLE...KEEPING THEM ON THE COLDER END OF GUIDANCE WITH MOST
SPOTS IN THE MID TO UPPER 20S. GIVEN RECENT LACK OF RAINFALL
ACROSS THE CWA AND FACT THAT BREEZES SHOULD AVERAGE AROUND
5KT...NOT EXPECTING ANY FOG ISSUES TONIGHT BUT SUPPOSE SOME LIGHT
DEVELOPMENT IS NOT OUT OF THE QUESTION.
CONDITIONS WILL REALLY START TURNING SEASONABLY PLEASANT FOR
WEDNESDAY AS MID LEVEL HEIGHTS RISE IN RESPONSE TO A BROAD RIDGE
AXIS ESTABLISHING ITSELF ACROSS THE CENTRAL CONUS. FAIRLY LIGHT
WESTERLY BREEZES WILL DOMINATE THE DAYTIME HOURS. DESPITE FAIRLY
SHALLOW MIXING TO ONLY AROUND 900MB...STILL FEEL THAT MOST OF THE
CWA SHOULD BRUSH THE 60 MARK FOR HIGHS...WITH MID 60S FOR MOST KS
ZONES.
WED NIGHT...STEADY LIGHT SOUTHERLY BREEZES WILL BE IN PLACE AT THE
SURFACE AS THE FLOW ALOFT STARTS TO TURN SOUTHWESTERLY IN ADVANCE
OF THE NEXT SYSTEM ALONG THE WEST COAST. ALTHOUGH THESE BREEZES
WILL HELP KEEP LOW TEMPS A BIT WARMER THAN TONIGHT...FELT THAT
RECENT TRENDS OF ENDING UP TOO WARM WITH LOWS UNDER CLEAR SKIES
JUSTIFIED KNOCKING 2-3 DEGREES OFF PREVIOUS FORECAST...NOW
BRINGING MOST AREAS DOWN INTO THE LOW 30S.
THANKSGIVING DAY...DRY AND AT LEAST MOSTLY SUNNY CONDITIONS
PERSIST...ALTHOUGH SOUTH WINDS WILL INCREASE A BIT INTO THE
SUSTAINED 10-20 MPH RANGE AS A HIGH PLAINS LEE TROUGH DEEPENS A
BIT. THE HIGHEST WINDS IN THIS RANGE WILL FOCUS ACROSS THE
SOUTHEAST 1/2 OF THE CWA. TEMP WISE...ALTHOUGH MIXING WILL REMAIN
SOMEWHAT SHALLOW...SEE NO REASON WHY SOUTHERLY FLOW WON/T BOOST
HIGHS ANOTHER NOTCH...AND ACTUALLY RAISED 2-4 DEGREES OVER
PREVIOUS FORECAST PUTTING MOST OF THE CWA WELL INTO THE 60S...AND
EVEN UPPER 60S IN PARTS OF KS. IF THESE NUMBERS HOLD...THIS LOOKS
TO BE THE WARMEST THANKSGIVING DAY IN THE TRI-CITIES SINCE 2006.
THURS NIGHT...KEPT DRY...BUT INCREASING HIGH LEVEL CLOUDS WILL
ACCOMPANY THE LEADING EDGE OF SHORTWAVE ENERGY EJECTING OUT OF
THE WEST. MODEST INCREASE IN LOW LEVEL MOISTURE...SOUTHERLY
BREEZES AND INCREASING CLOUDS SHOULD MAKE THIS THE OVERALL WARMEST
NIGHT OF THE FORECAST PERIOD...WITH LOWS HOLDING UP IN THE
MID/UPPER 30S IN MOST OF THE CWA...AND EVEN LOW 40S SOUTHEAST.
.LONG TERM...FRIDAY THROUGH MONDAY. GENERALLY USED AN INTERMEDIATE
COMBINATION OF GUIDANCE SPREADS FOR THE LONG TERM FORECAST. MODELS
ARE STILL INDICATING A SHORTWAVE TROUGH TO SWING THROUGH FROM THE
NORTHWEST FOR FRIDAY/FRIDAY NIGHT. WITH DRY AIR IN PLACE...THE
BEST BET FOR ANY PRECIPITATION WILL BE IN OUR EASTERN CWA WHERE
WHERE SOME LOWER LEVEL GULF INFLOW COULD SPREAD INTO THAT AREA
WITH THE AID OF SOME BACKING WIND AS THE SURFACE COLD FRONT
APPROACHES. THE TRI-CITIES MAY BE ON THE FAR WESTERN EDGE OF ANY
PRECIPITATION THAT DEVELOPS BUT MODELS ARE TRENDING A BIT FARTHER
WEST. WHERE MODELS HAD INDICATED A CLOSED AND EVENTUALLY CUTOFF
LOW OVER THE SOUTHWEST UNITED STATES/MEXICO FOR FRIDAY FROM MODEL
RUNS LAST NIGHT...THIS CUTOFF HAS BEEN PUSHED BACK TO SATURDAY
NIGHT ON THE ECMWF AND DOES NOT OCCUR AT ALL ON THE GFS AS THE
SOUTHERN AND NORTHERN STREAMS PHASE WAVES FOR FRIDAY. MODELS STILL
MOVE THE WAVE THROUGH QUICKLY WITH RIDGING FOLLOWING...KEEPING A
DRY FORECAST THROUGH THE WEEKEND INTO MONDAY AS THE WAVE DIGS TO
THE EAST OF THE MISSOURI VALLEY.
SATURDAY IS STILL LOOKING QUITE BREEZY/WINDY AS SURFACE HIGH
PRESSURE BUILDS IN. MODELS DIFFER BY VARYING DEGREES ON
TEMPERATURES...BUT GENERALLY LOOK SEASONABLY COOL.
&&
.PREV DISCUSSION... /ISSUED 1107 PM CST MON NOV 21 2011/
AVIATION...06Z TAF. LATE EVENING 11-3.9 MICRON SATELLITE IMAGERY
SHOWS THE BACK EDGE OF THE MID AND HIGH LEVEL CLOUDS IS MAKING
GRADUAL PROGRESS EAST AS A MID LEVEL DISTURBANCE CONTINUES TO
TRACK ACROSS THE REGION. A FEW SPRINKLES MANAGED TO DEVELOP IN THE
VICINITY OF KGRI...BUT THOSE SHOULD REMAIN ISOLATED ENOUGH TO OMIT
FROM THE FORECAST. ANOTHER CONCERN IS THE POSSIBILITY OF MVFR
CEILINGS DUE TO STRATUS THAT IS LOCATED JUST EAST OF THE TERMINAL.
THE MID AND HIGH LEVEL CLOUDS MAKE IT NEARLY IMPOSSIBLE TO SEE THE
STRATUS ON SATELLITE...BUT SURFACE OBSERVATIONS TELL THE STORY
WITH KAUH AT TIMES REPORTING AN MVFR CEILING. THE LATEST RUC
SUGGESTS THE CLOUDS COULD MAKE A RUN TOWARDS KGRI AS PER H925 RH
FORECASTS...WHILE THE NAM KEEPS THE CLOUDS JUST EAST OF THE
TERMINAL LOCATION. WILL CONTINUE TO MENTION SCATTERED CLOUDS
AROUND 1500FT...BUT NOT GO WITH A CEILING AT THIS TIME. CLOUDS
SHOULD DECREASE QUICKLY AFTER 12Z TUESDAY...AND WILL ONLY CARRY
SCATTERED HIGH LEVEL CLOUDS. WINDS SHOULD REMAIN LIGHT AND
VARIABLE MUCH OF THE PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...HEINLEIN
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
954 PM EST WED NOV 23 2011
.SYNOPSIS...
LOW PRESSURE IS EXITING EASTWARD THROUGH THE GULF OF MAINE. IN
THE WAKE OF THE LOW PRESSURE SYSTEM...A RIDGE OF HIGH PRESSURE
WILL BUILD EASTWARD ACROSS THE NORTH COUNTRY BRINGING DRY WEATHER
FOR THANKSGIVING AND RIGHT THROUGH THE UPCOMING WEEKEND.
TEMPERATURES WILL BE NEAR NORMAL FOR THANKSGIVING WITH HIGHS IN
THE UPPER 30S...THEN MODERATING TO ABOVE AVERAGE READINGS FOR
FRIDAY THROUGH NEXT MONDAY. THE NEXT CHANCE FOR PRECIPITATION
WILL BE LATE SUNDAY INTO MONDAY AS A FRONTAL BOUNDARY APPROACHES
THE AREA FROM THE WEST.
&&
.NEAR TERM /UNTIL 11 AM THURSDAY MORNING/...
AS OF 954 PM EST WEDNESDAY...MADE SOME MINOR ADDITIONAL ADJUSTMENTS
TO SKY COVER THROUGH TOMORROW AFTERNOON BASED OFF CURRENT
OBSERVATIONS AND LATEST NEAR-TERM MODEL DATA. RUC13 275K
ISENTROPIC PROGS SEEM TO CAPTURE CURRENT SITUATION NICELY INTO THE
OVERNIGHT HOURS...WITH CLOUDS ESSENTIALLY HANGING TOUGH...ESP THE
NORTHWESTERN HALF OF THE FORECAST AREA DESPITE LOW PRESSURE
PULLING WELL EAST INTO THE MARITIMES. AS FLOW ALOFT TRENDS
WESTERLY LATER TONIGHT...SOME CLEARING LIKELY IN THE CT RIVER
VALLEY...AND POSSIBLY INTO THE SLV. ELSEWHERE GENERALLY MOSTLY
CLOUDY TO CLOUDY. THIS WILL TEMPER OVERNIGHT LOWS ABOVE 12/18Z MOS
GUIDANCE...WITH VALUES GENERALLY BOTTOMING OUT IN THE 20S...THOUGH
LOCALLY TEENS IN THE NRN CT RVR VALLEY FROM ORANGE COUNTY
NORTHWARD. OUTSIDE A STRAY FLURRY...NO ADDITIONAL PCPN EXPECTED
OVERNIGHT AS NORTHERLY WINDS TREND LIGHT.
FOR THANKSGIVING DAY...A DRY FORECAST WITH RISING HEIGHTS ALOFT.
AS MENTIONED ABOVE I`VE MADE SOME ADDITIONAL CHANGES TO SKY
COVER...KEEPING MAINLY CLOUDY SKIES ACROSS OUR CENTRAL/NRN
COUNTIES...AND OFFERING PTLY SUNNY CONDS SOUTH. AIR MASS IS
SLOWLY MODERATING...BUT GENERALLY EXPECTING HIGHS FROM THE MID 30S
ACROSS ERN VT TO THE UPR 30S IN THE CHAMPLAIN VALLEY. WARMEST
TEMPS EXPECTED IN THE ST. LAWRENCE VALLEY /LOW TO MID 40S/. SNOW
COVER WILL HELP HOLD DOWN TEMPS SOMEWHAT FROM THE ADIRONDACKS EWD
ACROSS VT. WINDS WILL START LIGHT...THEN BECOMING S-SW AT 5-10 MPH
IN THE AFTN.
&&
.SHORT TERM /11 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 247 PM EST WEDNESDAY...A QUIET PERIOD OF WEATHER EXPECTED
FOR THE SHORT-TERM PERIOD WITH NIL POPS. SFC RIDGE AXIS SHIFTS
SOUTH OF NEW ENGLAND ALLOWING FOR A STRONGER WSWLY GRADIENT FLOW
TO DEVELOP OVER THE NORTH COUNTRY. WINDS ON FRIDAY COULD BECOME
LOCALLY BREEZY...GENERALLY SOUTHWEST 15-25 MPH. THERE WILL ALSO
BE MODERATING TEMPERATURES DURING THE PERIOD. LOWS THURSDAY NIGHT
WILL GENERALLY BE 25-30F...THOUGH LOCALLY COLDER READINGS ARE
POSSIBLE IN FAR NERN VT. WITH 850MB THERMAL RIDGE AXIS IN
PLACE...HIGHS BOUNCE BACK TO THE UPR 40S ON FRIDAY AND A FEW LOW
50S ACROSS NRN NY. THIS WILL ALLOW FOR SOME MELTING OF RECENT
SNOWFALL. THERE MAY BE A TENDENCY FOR A FRONTAL BOUNDARY TO
DEVELOP ALONG THE INTL BORDER FRIDAY INTO FRIDAY NIGHT. CLOUD
FORECAST IS GENERALLY PARTLY TO MOSTLY CLOUDY...WITH THE GREATER
CLOUD AMTS ACROSS NRN AREAS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 330 PM EST WEDNESDAY...HIGH PRESSURE IS EXPECTED TO
CONTINUE FROM SATURDAY THROUGH EARLY SUNDAY...WITH DRY WEATHER
AND ABOVE-NORMAL TEMPERATURES. EUROPEAN AND GFS CONTINUE TO
DISAGREE WITH RESPECTS TO THE SUNDAY THROUGH WEDNESDAY TIME
PERIOD. BOTH MODELS SHOW A LOW PRESSURE SYSTEM LIFTING NORTH OF
THE REGION ON SUNDAY...WITH BULK OF PRECIPITATION SUNDAY
NIGHT....MAINLY RAIN SHOWERS IN THE VALLEYS WITH SOME SNOW MIXING
IN THE HIGHER ELEVATIONS. MODELS DIVERGE GREATLY AFTER SUNDAY
NIGHT...WITH THE GFS KEEPING AFOREMENTIONED FRONT AROUND THROUGH
TUESDAY AND LIFTING A CUT OFF LOW ACROSS THE REGION. ECMWF DOES
NOT HAVE THIS FEATURE AT ALL. THEREFORE...CAN NOT PUT MUCH WEIGHT
BEHIND EITHER OF THESE MODELS. WOULD LIKE TO SEE MODELS COME INTO
BETTER AGREEMENT WITH RESPECT TO THE EXTENDED. AT THIS TIME BEST
CHANCE FOR PRECIP IN THE EXTENDED LOOKS TO BE SUNDAY INTO SUNDAY
NIGHT.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
THROUGH 00Z FRIDAY...ABUNDANT LOW-LEVEL MOISTURE THIS EVENING HAS
HELPED TO PERSIST WIDESPREAD MVFR TO IFR CEILINGS/VISIBILITIES. AN
AREA OF LAKE EFFECT SNOW HAS DEVELOPED OVER THE PAST COUPLE HOURS
SO STILL COULD SEE PERIODS OF LIGHT SNOW AT BTV OVER THE NEXT
COUPLE OF HOURS. OTHERWISE EXPECT MVFR TO IFR CONDITIONS TO
PREVAIL THROUGH THE OVERNIGHT HOURS. NORTH WINDS AROUND 10 KNOTS
BECOME LIGHT/VARIABLE OVERNIGHT AS RIDGE OF HIGH PRESSURE BUILDS
IN. CONDITIONS TOMORROW TREND TOWARD VFR THOUGH LINGERING MVFR
CEILINGS STILL POSSIBLE AT SLK.
OUTLOOK 00Z FRIDAY THROUGH MONDAY...VFR CONDITIONS EXPECTED THROUGH
THE PERIOD AS A RIDGE OF HIGH PRESSURE BUILDS OVER THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...JMG/BANACOS
SHORT TERM...BANACOS
LONG TERM...NEILES
AVIATION...NEILES/LOCONTO
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
951 PM EST WED NOV 23 2011
.SYNOPSIS...
LOW LEVEL MOISTURE BEHIND DEPARTED FRONT...CAUSES ONLY GRADUAL
BREAKUP OF CLOUDS TONIGHT...AND AREAS OF FOG WHERE IT DOES CLEAR.
DRY HIGH PRESSURE AND WARMING TEMPERATURES THANKSGIVING DAY RIGHT
INTO THE WEEKEND. WET SYSTEM BY EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
930 PM UPDATE...BACK EDGE OF THE CLEARING SKIES IS MAKING GOOD
PROGRESS EAST...NOW INTO STEUBEN AND YATES COUNTIES. THIS LINE
WILL CONTINUE TO MAKE PROGRESS EAST THROUGH THE NEXT FEW
HOURS...REACHING THE SYRACUSE AREA BY MIDNIGHT. FARTHER SOUTH AND
EAST WHILE THE SKY IS STILL EXPECTED TO CLEAR...MOISTURE FROM THE
FINGER LAKES AND THE UPSLOPE FLOW (NORTHWEST WIND) MAY KEEP SKIES
CLOUDY A BIT LONGER. STILL EXPECT EVERYONE TO CLEAR OUT...AT LEAST
CLOUD WISE...BY 10Z. BASED ON THE OBS ACROSS STEUBEN COUNTY WITH
HORNELL DOWN TO 1/4SM IN FOG...EXPECT AREAS OF FOG TO FORM
OVERNIGHT AND IT COULD BE QUITE DENSE GIVEN OUR RECENT RAINFALL.
WILL CONTINUE TO HIGHLIGHT AREAS OF FOG IN THE GRIDS.
ONE MORE THING TO ADD....WITH THE RUC SHOWING THE CORE OF COLD AIR
OVER THE FINGER LAKES NOW (-3C) AND A WIND OUT OF THE
NORTHWEST...KBGM IN CLEAR AIR MODE IS SHOWING SOME LIGHT ECHOES
DOWNWIND OF CAYUGA AND OWASCO LAKES (LAKE EFFECT FLURRIES). THROUGH
MIDNIGHT SOME SCT. FLURRIES ARE POSSIBLE...MAINLY ACROSS THE
HIGHER TERRAIN...ACROSS
TOMPKINS...CORTLAND...TIOGA...BROOME...BRADFORD...SUSQUEHANNA...AND
WAYNE COUNTIES.
AT 3 PM...FRONT IS WELL EAST OF THE AREA...BUT UPPER TROUGH
AXIS IS STILL FINISHING ITS TREK THROUGH THE AREA...AS CLEARLY
MARKED VIA MOISTURE SPOKE ON THE WATER VAPOR IMAGERY LOOP. UPPER
TROUGH AXIS AND WEAKENING MID LEVEL DEFORMATION ARE PAIRED UP OVER
THE EASTERN HALF OF THE AREA...YET DEEPER MOISTURE IS ALREADY WELL
TO OUR EAST. SO WITH SHALLOW SATURATED LAYER...ONLY DIMINISHING
LIGHT SHOWERS AND PATCHY DRIZZLE EARLY THIS EVENING. OUR HIGH
TEMPS OCCURRED EARLY TODAY...YET BECAUSE TEMPERATURE WITHIN THE
SHALLOW SATURATED LAYER STAYS ABOVE MINUS-5 DEGREES CELSIUS...NOT
SEEING ANY OPPORTUNITY FOR CRYSTAL FORMATION. THUS WITH ANY
SHOWERS THAT ARE LEFT...VERY LITTLE IF ANY MIX WITH SNOW EVEN AT
HIGHER ELEVATIONS...AND CERTAINLY NO ACCUMULATION.
TONIGHT...925MB RH FIELDS SUGGEST THAT DESPITE DRY OVERALL
AIR MASS...LOW LEVEL MOISTURE FROM LAKE ONTARIO...AND IN
GENERAL...GETS TRAPPED UNDER DEVELOPING INVERSION AS WARM AIR
ADVECTION ALREADY BEGINS ALOFT OVERNIGHT. THE WET GROUND FROM 1-2
INCHES OF PRIOR RAINFALL ALSO WILL AID IN MOIST LOW LEVELS.
THUS...LOW CLOUDS WILL BE VERY STUBBORN TO BREAK...AND SKY GRIDS
HAVE BEEN ADJUSTED ACCORDINGLY. THOSE AREAS THAT DO CLEAR COULD
HAVE AREAS OF FOG FORM BECAUSE OF THE WET GROUND...WITH WET GROUND
AND WEAKENING/DECOUPLING WINDS. AREAS WEST OF I-81 HAVE THE BEST
CHANCE FOR FOG FORMATION. WE WILL HAVE TO MONITOR FOR PROSPECTS OF
FREEZING FOG EARLY IN THE MORNING IF IT MANAGES TO GET LOCALLY
DENSE. WITH AMOUNT OF LOW LEVEL MOISTURE...I EXPECT LOW
TEMPERATURES TONIGHT TO BE SLIGHTLY ABOVE MODEL GUIDANCE NUMBERS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
HIGH PRESSURE RIDGE AT SURFACE AND ALOFT TAKES OVER FOR
THANKSGIVING AND FRIDAY. IN ADDITION TO ABUNDANT SUNSHINE...THE
SOUTHWEST SURFACE FLOW AROUND THE HIGH CENTERED TO OUR SOUTH...AND
RISING THICKNESSES...ALL HELP YIELD WARMING
TEMPERATURES...ESPECIALLY FRIDAY AND SATURDAY WITH HIGHS ABOUT 15
TO 20 DEGREES ABOVE NORMAL. ONLY FLY IN THE OINTMENT IS THAT
MOISTURE WILL STILL BE COMING OFF OF LAKE ONTARIO INITIALLY
THURSDAY...WHICH MAY MEAN SOME CLOUD COVER IN ONEIDA COUNTY...YET
STILL TEMPERATURES WILL BE IN A WARMING TREND THERE.
A NORTHERN STREAM FRONTAL BOUNDARY WILL ATTEMPT TO SAG SOUTH
FRIDAY NIGHT TO SATURDAY MORNING...BUT AT THIS TIME I AGREE WITH
NAM/GFS IN NOT BRINGING IT CLOSE ENOUGH TO IMPACT OUR WEATHER
OTHER THAN PERHAPS A FEW EXTRA CLOUDS IN THE NORTHERN ZONES.
HOWEVER CLOSE THAT FRONT APPROACHES...IT WILL SURGE BACK NORTHWARD
SATURDAY WITH INCREASING SOUTHWESTERLY FLOW.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MAIN FOCUS IN THE MEDIUM RNG IS THE AMPLIFYING TROF WHICH IS
FORECAST TO MOV INTO THE CNTRL AND THE ERN U.S. EARLY NXT WEEK.
THERE ARE SIG DIFFS IN THE MDLS W/RESPECT TO TIMING...PCPN
AMTS...AND NRN/SRN STREAM INTERACTION. GFS PAINTS A POTNL FLOOD
SCENARIO WITH SRN PORTION OF THE TROF CUTTING OFF THEN LIFTING
NEWD...WITH +RA ACRS THE FSCT AREA SUN NGT INTO MONDAY ALONG AN
INVERTED TROF. THE EURO SHOWS LESS INTERACTION BETWEEN NRN AND SRN
STREAMS...BUT STILL SHOWS RAIN WORKING NWD INTO THE RGN LATE MON
NGT INTO TUE...BUT THE HEAVIEST PCPN IS SHUNTED OFF TO OUR
SOUTHEAST. GIVEN THESE DIFFS...WE LEANED HEAVILY ON HPC GUIDANCE
FOR THE MEDIUM RNG..WHICH PAINTS AN UNSETTLED PICTURE INTO
MIDWEEK.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
EXTRAPOLATION OF THE BACKEDGE OF THE IFR/MVFR CIGS GETS IT INTO
SYR/ELM IN THE 05-06Z TIME FRAME...08Z AT BGM...AND ARND 10Z AT
RME. AT AVP...BEST GUESS ATTM IS ARND 05-06Z AS SRN EDGE OF THE
LOW CLDS APPEAR TO BE ERODING. AFTER THIS TIME...VFR WILL PREVAIL
WITH GNRLY CLEAR SKIES. WILL HAVE TO WATCH FOR PSBL VLY FOG AT ELM
TWDS DAYBREAK BUT NOT CONFIDENT ENUF TO ADD IN THIS PCKG. WINDS
NRLY TNGT 10-15 KTS DIMINISHING TO 5 KTS...BECMG WRLY 10-15 KTS ON
THU.
OUTLOOK...
THU THROUGH SAT...VFR.
SUN/MON...IFR/MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...HEDEN/MDP
SHORT TERM...MDP
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
934 PM EST WED NOV 23 2011
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD IN TONIGHT. HIGH PRESSURE
WILL THEN REMAIN IN PLACE THROUGH THE END OF THE WEEK...GIVING US
DRY CONDITIONS AND A WARMING TREND INTO SATURDAY. A COLD FRONT
WILL APPROACH BY LATE SATURDAY WITH SHOWERS FOR SATURDAY NIGHT
INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
A BAND OF STRATUS CURRENTLY STRETCHES FROM SOUTH-CENTRAL
MICHIGAN...CURVED SOUTH-SOUTHEAST TOWARD LIMA...AND THEN
EXPANDING EXTENSIVELY SOUTHWEST INTO SOUTHERN INDIANA AND
KENTUCKY. AS THESE CLOUDS SLOWLY DRIFT EAST-NORTHEAST...THEY WILL
NOT BE GOING AWAY ANY TIME SOON...AS THE MOISTURE REMAINS TRAPPED
UNDER RELATIVE HIGH PRESSURE. THE PRIMARY FORECAST UPDATE WAS TO
ADD CLOUDY TO MOSTLY CLOUDY SKIES FOR THE WESTERN HALF OF THE
FORECAST AREA...AND ALLOW SOME INCREASE IN CLOUDS FOR THE EASTERN
HALF OVERNIGHT. THE HRRR VISIBILITY PRODUCT IS SUGGESTING THAT
DENSE FOG COULD FORM IN THE CURRENT CLEAR AREA IN THE EASTERN HALF
OF THE CWA...WHERE WINDS HAVE GONE MOSTLY CALM. WILL CONTINUE TO
MONITOR THIS POSSIBILITY...THOUGH IT REMAINS UNCERTAIN GIVEN THE
CLOUD COVER MOVING IN THAT GENERAL DIRECTION FROM THE WEST.
RAISED TEMPERATURES A BIT IN THE WEST (ESPECIALLY
SOUTHWEST)...KEEPING THINGS ABOVE FREEZING FOR ALL BUT THE FAR
EAST.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
HIGH PRESSURE WILL BE CENTERED ACROSS THE OHIO VALLEY AS IT SLOWLY
WORKS OFF TO THE EAST. ANY MORNING LOW LEVEL MOISTURE CLOUDS THAT
MIGHT HAPPEN TO DRIFT INTO THE AREA SHOULD DIMINISH. TEMPS NEAR
GUIDANCE THROUGH PERIOD EXCEPT A BIT LOWER THURSDAY NIGHT AND
LITTLE WARMER FRIDAY NIGHT WITH SOUTHERLY FLOW WITH DRY
CONDITIONS THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
A STRONG COLD FRONT WITH COPIOUS MOISTURE WILL APPROACH THE AREA ON
SATURDAY. WITH GFS TRENDING FASTER WITH RESPECT TO THIS
SYSTEM...SPED UP ONSET OF CHANCE OF SHOWERS TO SATURDAY AFTERNOON IN
WESTERN COUNTIES. ENTIRE AREA SHOULD SEE SHOWERS SATURDAY NIGHT AND
SUNDAY AS THE FRONT PUSHES THROUGH. KEPT THUNDER OUT OF THE FORECAST
AS IT APPEARS THAT INSTABILITY WILL BE LACKING.
AFTER THE FRONT MOVES EAST ON SUNDAY...AN UPPER TROUGH WILL KEEP A
LOW CHANCE OF SHOWERS INTO MONDAY...MAINLY IN EASTERN COUNTIES.
ANOTHER UPPER DISTURBANCE PASSING THROUGH THE GREAT LAKES MAY BRING
A FEW SHOWERS TO NORTHERN LOCATIONS ON TUESDAY. EXPECT MAINLY DRY
WEATHER ON WEDNESDAY WITH HIGH PRESSURE PUSHING IN FROM THE
SOUTHWEST.
TEMPERATURES WILL START OUT ABOVE NORMAL ON SATURDAY AHEAD OF THE
COLD FRONT...WITH HIGHS FORECAST TO BE AROUND 60. HIGHS WILL BE NEAR
NORMAL IN THE 40S SUNDAY THROUGH TUESDAY. COLDER READINGS AROUND 40
MAY BE IN STORE FOR WEDNESDAY.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
SURFACE HIGH PRESSURE CURRENTLY CENTERED OVER THE LOWER OHIO
VALLEY WILL SLOWLY DRIFT EASTWARD OVERNIGHT INTO THURSDAY WITH LOW
LEVEL FLOW BACKING TO THE SOUTHWEST. MAIN FORECAST CONCERN FOR
THE TAF PERIOD IS THE POTENTIAL FOR LOW CEILINGS TONIGHT. A
PERSISTENT LOW STRATUS DECK OVER INDIANA... SOUTHERN
ILLINOIS...AND WESTERN KENTUCKY WAS SLOWLY ERODING EARLIER THIS
AFTERNOON. HOWEVER...NOW THAT THE SUN IS DOWN THOSE CLOUDS SHOULD
STICK AROUND FOR TONIGHT AND PERHAPS EVEN INCREASE IN AERIAL
COVERAGE AS THE LATEST RUC GUIDANCE SUGGESTS. THESE CLOUDS ARE
THE RESULT OF TRAPPED LOW LEVEL MOISTURE DUE TO A SUBSIDENCE
INVERSION ASSOCIATED WITH THE HIGH. LATEST SATELLITE IMAGERY SHOWS
A SLOW EASTWARD PROGRESSION WITH THIS CLOUD DECK...ALREADY
ENCROACHING ON KCVG. WENT WITH IFR CEILINGS TONIGHT FOR THE
WESTERN TAF SITES BASED ON WHAT HAPPENED FURTHER UPSTREAM LAST
NIGHT. MAY ALSO SEE SOME VFR TO MVFR VSBY REDUCTION AT KCVG/KLUK
DUE TO MIST...BUT EXPECT THE CLOUD DECK TO GENERALLY LIMIT MIST
DEVELOPMENT TONIGHT. CONFIDENCE IN CEILINGS IS LOWER FOR THE
EASTERN TAF SITES SO ONLY WENT WITH A SCATTERED LOW CLOUD DECK
THERE. ANY STRATUS THAT LINGERS INTO THURSDAY MORNING WILL TAKE
TIME TO ERODE...BUT WENT WITH SKC BY 17Z.
OUTLOOK...MVFR CIGS/VSBYS POSSIBLE SUNDAY AND MONDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...PADGETT
NEAR TERM...HATZOS
SHORT TERM...PADGETT
LONG TERM...CONIGLIO
AVIATION...KURZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
701 PM EST WED NOV 23 2011
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD IN TONIGHT. HIGH PRESSURE
WILL THEN REMAIN IN PLACE THROUGH THE END OF THE WEEK...GIVING US
DRY CONDITIONS AND A WARMING TREND INTO SATURDAY. A COLD FRONT
WILL APPROACH BY LATE SATURDAY WITH SHOWERS FOR SATURDAY NIGHT
INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
HIGH PRESSURE CONTINUES TO BUILD IN. SKIES HAVE CLEARED EXCEPT FOR
THE FAR SOUTHWEST WHERE LOW LEVEL MOISTURE REMAINS. QUESTION IS
IF CLOUDS WILL RETURN TO CWA TONIGHT. MOISTURE REMAINS TRAPPED TO
THE SOUTHWEST OF CWA. WITH HIGH SHIFTING EASTWARD OVERNIGHT SOME
CLOUDS MAY PUSH BACK INTO THE SOUTHWEST PART OF CWA. HOWEVER NOT
CONFIDENT ENOUGH TO MAKE WHOLESALE CHANGE TO CURRENT FCST. SO LEFT
CLEARING AS IS AND BANK ON CLOUDS JUST STAYING OUT OF MOST OF THE
AREA. WILL HAVE TO MONITOR FOR ANY CHANGES TO THIS THOUGHT. HAVE
BUMPED UP LOW TEMPS JUST A BIT FROM PREVIOUS FCST BUT BELIEVE
COLDER THAN GUIDANCE IS THE WAY TO GO WITH LIGHT WINDS AND GOOD
RADIATIONAL COOLING ALONG AS CLOUDS DO NOT RETURN.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
HIGH PRESSURE WILL BE CENTERED ACROSS THE OHIO VALLEY AS IT SLOWLY
WORKS OFF TO THE EAST. ANY MORNING LOW LEVEL MOISTURE CLOUDS THAT
MIGHT HAPPEN TO DRIFT INTO THE AREA SHOULD DIMINISH. TEMPS NEAR
GUIDANCE THROUGH PERIOD EXCEPT A BIT LOWER THURSDAY NIGHT AND
LITTLE WARMER FRIDAY NIGHT WITH SOUTHERLY FLOW WITH DRY
CONDITIONS THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
A STRONG COLD FRONT WITH COPIOUS MOISTURE WILL APPROACH THE AREA ON
SATURDAY. WITH GFS TRENDING FASTER WITH RESPECT TO THIS
SYSTEM...SPED UP ONSET OF CHANCE OF SHOWERS TO SATURDAY AFTERNOON IN
WESTERN COUNTIES. ENTIRE AREA SHOULD SEE SHOWERS SATURDAY NIGHT AND
SUNDAY AS THE FRONT PUSHES THROUGH. KEPT THUNDER OUT OF THE FORECAST
AS IT APPEARS THAT INSTABILITY WILL BE LACKING.
AFTER THE FRONT MOVES EAST ON SUNDAY...AN UPPER TROUGH WILL KEEP A
LOW CHANCE OF SHOWERS INTO MONDAY...MAINLY IN EASTERN COUNTIES.
ANOTHER UPPER DISTURBANCE PASSING THROUGH THE GREAT LAKES MAY BRING
A FEW SHOWERS TO NORTHERN LOCATIONS ON TUESDAY. EXPECT MAINLY DRY
WEATHER ON WEDNESDAY WITH HIGH PRESSURE PUSHING IN FROM THE
SOUTHWEST.
TEMPERATURES WILL START OUT ABOVE NORMAL ON SATURDAY AHEAD OF THE
COLD FRONT...WITH HIGHS FORECAST TO BE AROUND 60. HIGHS WILL BE NEAR
NORMAL IN THE 40S SUNDAY THROUGH TUESDAY. COLDER READINGS AROUND 40
MAY BE IN STORE FOR WEDNESDAY.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
SURFACE HIGH PRESSURE CURRENTLY CENTERED OVER THE LOWER OHIO
VALLEY WILL SLOWLY DRIFT EASTWARD OVERNIGHT INTO THURSDAY WITH LOW
LEVEL FLOW BACKING TO THE SOUTHWEST. MAIN FORECAST CONCERN FOR
THE TAF PERIOD IS THE POTENTIAL FOR LOW CEILINGS TONIGHT. A
PERSISTENT LOW STRATUS DECK OVER INDIANA... SOUTHERN
ILLINOIS...AND WESTERN KENTUCKY WAS SLOWLY ERODING EARLIER THIS
AFTERNOON. HOWEVER...NOW THAT THE SUN IS DOWN THOSE CLOUDS SHOULD
STICK AROUND FOR TONIGHT AND PERHAPS EVEN INCREASE IN AERIAL
COVERAGE AS THE LATEST RUC GUIDANCE SUGGESTS. THESE CLOUDS ARE
THE RESULT OF TRAPPED LOW LEVEL MOISTURE DUE TO A SUBSIDENCE
INVERSION ASSOCIATED WITH THE HIGH. LATEST SATELLITE IMAGERY SHOWS
A SLOW EASTWARD PROGRESSION WITH THIS CLOUD DECK...ALREADY
ENCROACHING ON KCVG. WENT WITH IFR CEILINGS TONIGHT FOR THE
WESTERN TAF SITES BASED ON WHAT HAPPENED FURTHER UPSTREAM LAST
NIGHT. MAY ALSO SEE SOME VFR TO MVFR VSBY REDUCTION AT KCVG/KLUK
DUE TO MIST...BUT EXPECT THE CLOUD DECK TO GENERALLY LIMIT MIST
DEVELOPMENT TONIGHT. CONFIDENCE IN CEILINGS IS LOWER FOR THE
EASTERN TAF SITES SO ONLY WENT WITH A SCATTERED LOW CLOUD DECK
THERE. ANY STRATUS THAT LINGERS INTO THURSDAY MORNING WILL TAKE
TIME TO ERODE...BUT WENT WITH SKC BY 17Z.
OUTLOOK...MVFR CIGS/VSBYS POSSIBLE SUNDAY AND MONDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...PADGETT
NEAR TERM...PADGETT
SHORT TERM...PADGETT
LONG TERM...CONIGLIO
AVIATION...KURZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
552 PM EST TUE NOV 22 2011
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL CONTINUE MOVING NORTHEAST THROUGH THE
OHIO VALLEY TONIGHT. AFTER A COLD FRONT PASSES THE
REGION...PRECIPITATION WILL COME TO AN END EARLY ON WEDNESDAY.
HIGH PRESSURE WILL BUILD IN THROUGH THE END OF THE
WEEK...PROVIDING FAIR CONDITIONS AND MOSTLY CLEAR SKIES.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
23Z UPDATE >
SCALED BACK THUNDER CHANCES EVEN FURTHER THAN THE LAST
UPDATE...AND MADE SOME TIMING ADJUSTMENT TO THE POPS TO ACCOUNT
FOR CURRENT TRENDS. THE EXPECTED NEAR-ZERO INSTABILITY IS LOOKING
MORE LIKE ZERO AT THIS TIME...WITH JUST A FEW CONVECTIVE LOOKING
SHOWERS APPEARING NEAR THE COLD FRONT IN INDIANA. NO OTHER
SIGNIFICANT CHANGES WERE MADE TO THE FORECAST.
PREVIOUS DISCUSSION >
SURFACE ANALYSIS CURRENTLY INDICATES THAT LOW PRESSURE IS CENTERED
NEAR INDIANAPOLIS...MOVING NORTHEAST TOWARD LAKE ERIE. THE SHIELD
OF STEADY PRECIPITATION (NORTH OF THE WARM FRONT) HAS SHIFTED
NORTH OF THE FORECAST AREA...WITH SCATTERED SHOWERS REMAINING IN
PLACE NEAR THE WARM FRONT AND INTO THE WARM SECTOR.
CONVECTIVE POTENTIAL LATE THIS AFTERNOON AND TONIGHT HAS BEEN THE
FOCUS OF THE FORECAST TODAY. THE THETA-E SURGE AHEAD OF THE
SURFACE LOW HAS BEEN WELL MODELED BY THE NAM12 IN TERMS OF SPATIAL
EXTENT AND TIMING...BUT OVERDONE IN TERMS OF MAGNITUDE. MOST OF
THE CWA WILL FIND ITS WAY INTO THE WARM SECTOR OVER THE NEXT FEW
HOURS (ESPECIALLY ALONG AND SOUTH OF THE
METEOROLOGICALLY-CONVENIENT I-71 CORRIDOR). WHAT THIS MEANS IN
TERMS OF CONVECTION IS NOT TOTALLY CLEAR. THE NAM12 CAPE
DEPICTIONS SHOW UP TO 500 J/KG...WITH MUCH MORE SUBDUED NUMBERS
COMING IN FROM THE OTHER MODELS (AROUND 200 J/KG ON THE RUC AND
GFS) AND LAPS ANALYSIS. 15Z SREF PROBS FOR >500 J/KG ARE UNDER 20
PERCENT. IN ADDITION...THE EXPECTED SOURCE REGION FOR CONVECTION
(ACCORDING TO THE HRRR RADAR SIMULATIONS) IS IN CENTRAL
KENTUCKY...WHERE RAIN HAS ESSENTIALLY PUT AN END TO
DESTABILIZATION. THUS...IT IS BELIEVED THAT INSTABILITY WILL BE
EXTREMELY LIMITED FOR THIS EVENT. WHILE IT IS TRUE THAT DYNAMIC
WEATHER SYSTEMS SUCH AS THIS ONE ARE CAPABLE OF DOING A LOT WITH A
LITTLE (IN TERMS OF INSTABILITY)...NEAR-ZERO VALUES ARE NOT GOING
TO SUPPORT A SEVERE WEATHER THREAT.
IT IS EXPECTED THAT...EMBEDDED WITHIN THE LARGER AREAS OF
RAIN...SOME WEAK CONVECTION MAY BE ABLE TO DEVELOP. THERE ARE
SIGNS (HRRR / SPC-WRF) OF THIS OCCURRING ALONG A PRE-FRONTAL
TROUGH WITHIN THE NEXT COUPLE HOURS...AND THEN AGAIN ALONG THE
COLD FRONT DURING THE MID TO LATE EVENING. THE DYNAMICS OF THE
SYSTEM ALONE WILL SUPPORT SOME GUSTY WINDS...EVEN OUTSIDE OF
STORMS. BEFORE THE RAIN MOVED IN...THERE WERE GUSTS TO AROUND 40
KNOTS IN THE LEXINGTON/FRANKFORT AREA OF KENTUCKY. HOWEVER...THIS
WILL BE AN EXCEPTION AND NOT A RULE. 50 KNOT WINDS ARE UP
THERE...BUT AT ABOUT 4000 FEET. IT WILL BE EXTREMELY DIFFICULT
(IF NOT IMPOSSIBLE) TO MIX TO ANYTHING THAT HIGH IN A MOIST...WARM
ADVECTING...PRECIPITATING PATTERN LIKE THIS.
ASIDE FROM A BRIEF DOWNPOUR IN A THUNDERSTORM...THE THREAT FOR
HEAVY OR PROLONGED RAINFALL HAS ENDED. TOTALS FROM THE RAIN TODAY
HAVE GENERALLY RANGED BETWEEN 1.00 AND 1.50 INCHES...NOT ENOUGH TO
GENERATE WIDESPREAD FLOODING. RISES ON A FEW RIVERS WILL BE
MONITORED (INCLUDING THE QUICK-RESPONDING OHIO BRUSH CREEK IN
ADAMS COUNTY...WHICH IS ALREADY IN FLOOD) BUT NO AREAL PRODUCTS
WILL BE NEEDED.
AS THE COLD FRONT MOVES AWAY FROM THE REGION...ADDITIONAL SHOWERS
WILL DEVELOP IN THE WRAP-AROUND COLD ADVECTION FLOW BEHIND THE
SURFACE LOW (AND ASSOCIATED WITH THE AXIS OF THE UPPER TROUGH).
ACCOUNTED FOR THIS WITH A PERIOD OF CHANCE POPS OVERNIGHT...WITH
EVERYTHING ELSE OTHERWISE TAPERED DOWN TO SLIGHT CHANCE OR DRY.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
THE UPPER TROUGH WILL BE MOVING AWAY FROM THE REGION ON WEDNESDAY
MORNING...BRINGING AN END TO PRECIPITATION NOT LONG AFTER THE
START OF THE FORECAST PERIOD. AN EXTENSIVE AREA OF HIGH PRESSURE
WILL THEN BUILD INTO THE EASTERN HALF OF THE COUNTRY...REMAINING
IN PLACE THROUGH THE END OF THE WEEK.
MODEL RH DEPICTIONS...EVEN WHEN CONSIDERING ALL LAYERS OF THE
ATMOSPHERE...ARE COMING IN QUITE DRY WITH THIS HIGH AND ITS
ASSOCIATED UPPER RIDGE. WILL KEEP SKY GRIDS IN THE CLEAR TO MOSTLY
CLEAR RANGE. THE FIRST CLEAR NIGHT (WEDNESDAY NIGHT) LOOKS TO BE
THE COLDEST...WITH SUB-FREEZING TEMPERATURES EXPECTED IN GOOD
RADIATIONAL COOLING CONDITIONS. TEMPERATURES SHOULD GRADUALLY
MODERATE THROUGH THE REST OF THE PERIOD...WITH NO MAJOR
DIFFERENCES DETECTED IN THE VARIOUS MODEL NUMBERS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE LONG TERM WILL START OUT DRY WITH HIGH PRESSURE ACROSS THE
AREA. WITH WARM SOUTHERLY FLOW ACROSS THE REGION TEMPERATURES WILL
BE WELL ABOVE NORMAL FOR FRIDAY AND SATURDAY. HIGH TEMPERATURES
WILL BE IN THE 60S ACROSS MOST LOCATIONS. A STRONG LOW PRESSURE
SYSTEM WILL APPROACH THE AREA SATURDAY EVENING AND WILL IMPACT THE
AREA THROUGH THE END OF THE LONG TERM PERIOD. THERE ARE SOME MODEL
TIMING DIFFERENCES HOWEVER THE LATEST ECMWF HAS COME INTO PRETTY
GOOD AGREEMENT WITH THE GFS. DUE TO THIS AGREEMENT WENT WITH A
BLEND. RAIN WILL BEGIN TO MOVE INTO THE AREA SATURDAY EVENING AND
WILL BE WIDESPREAD ACROSS THE AREA ON SUNDAY. THE UPPER LOW BECOMES
CUT OFF BY SUNDAY AND LINGERS NEAR THE AREA THROUGH THE MIDDLE OF
NEXT WEEK. THIS WILL ALLOW FOR PRECIPITATION TO LINGER ACROSS THE
AREA AS WELL. COLDER AIR WORKING INTO THE AREA WILL ALLOW FOR SOME
SNOW SHOWER ACTIVITY TO MIX IN AS WELL MONDAY NIGHT INTO TUESDAY.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
LOW PRESSURE OVER SE ILLINOIS WILL TRACK NE TO WEST CENTRAL OHIO
THIS EVENING. THE LOW WILL THEN CONTINUE ENE TO A POSITION NEAR CNTRL
PENNSYLVANIA BY WEDNESDAY MORNING. A WARM FRONT WILL LIFT N INTO
THE REGION THIS AFTERNOON/EVENING...FOLLOWED BY A COLD FRONT.
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS WILL BECOME MORE
SCATTERED IN NATURE SOUTH OF THE WARM FRONT FROM MID AFTERNOON
INTO EARLY EVENING. SOME SHOWER ACTIVITY IS EXPECTED ALONG AND
AHEAD OF THE COLD FRONT...BUT ITS COVERAGE IS STILL SOMEWHAT
UNCERTAIN ATTM. FORECAST DILEMMA REVOLVES AROUND CIGS/VSBYS.
IFR/LIFR CIGS SHOULD LIFT BRIEFLY TO MVFR CIGS IN THE WARM
SECTOR...THEN BECOME IFR ONCE AGAIN BEHIND THE COLD FRONT IN THE
CAA. VSBYS WILL BE LOCALLY IFR WITH HEAVY RAIN ALONG AND NORTH OF
THE WARM FRONT...THEN MAINLY MVFR IN ANY SHOWERS ALONG AND AHEAD
OF THE COLD FRONT. SOME SHOWER ACTIVITY MAY OCCUR ACRS CNTRL OHIO
LATE TONIGHT ALONG A TROF AXIS. HAVE HANDLED THIS WITH A VCSH
MENTION. AS THE LOW PULLS AWAY FROM THE REGION WEDNESDAY MORNING
AND AFTERNOON...HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE
WEST. SIGNIFICANT DRYING IS EXPECTED AND THUS...IFR CIGS WILL
SCATTERED OUT AND BECOME CLEAR FROM WEST TO EAST BETWEEN 15Z AND
21Z WEDNESDAY.
WINDS WILL BE GUSTY IN THE WARM SECTOR AND BEHIND THE COLD FRONT.
HAVE GUSTS OF 25 TO 30 KNOTS...BUT OBSERVATIONS WILL HAVE TO BE
WATCHED SHOULD GUSTS BECOME HIGHER IN THE MORE UNCERTAIN WARM
SECTOR THIS AFTERNOON INTO EARLY THIS EVENING.
OUTLOOK...MVFR CIGS/VSBYS POSSIBLE SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...NOVAK
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
413 PM EST TUE NOV 22 2011
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL CONTINUE MOVING NORTHEAST THROUGH THE
OHIO VALLEY TONIGHT. AFTER A COLD FRONT PASSES THE
REGION...PRECIPITATION WILL COME TO AN END EARLY ON WEDNESDAY.
HIGH PRESSURE WILL BUILD IN THROUGH THE END OF THE
WEEK...PROVIDING FAIR CONDITIONS AND MOSTLY CLEAR SKIES.
&&
.NEAR TERM /TUESDAY NIGHT/...
SURFACE ANALYSIS CURRENTLY INDICATES THAT LOW PRESSURE IS CENTERED
NEAR INDIANAPOLIS...MOVING NORTHEAST TOWARD LAKE ERIE. THE SHIELD
OF STEADY PRECIPITATION (NORTH OF THE WARM FRONT) HAS SHIFTED
NORTH OF THE FORECAST AREA...WITH SCATTERED SHOWERS REMAINING IN
PLACE NEAR THE WARM FRONT AND INTO THE WARM SECTOR.
CONVECTIVE POTENTIAL LATE THIS AFTERNOON AND TONIGHT HAS BEEN THE
FOCUS OF THE FORECAST TODAY. THE THETA-E SURGE AHEAD OF THE
SURFACE LOW HAS BEEN WELL MODELED BY THE NAM12 IN TERMS OF SPATIAL
EXTENT AND TIMING...BUT OVERDONE IN TERMS OF MAGNITUDE. MOST OF
THE CWA WILL FIND ITS WAY INTO THE WARM SECTOR OVER THE NEXT FEW
HOURS (ESPECIALLY ALONG AND SOUTH OF THE
METEOROLOGICALLY-CONVENIENT I-71 CORRIDOR). WHAT THIS MEANS IN
TERMS OF CONVECTION IS NOT TOTALLY CLEAR. THE NAM12 CAPE
DEPICTIONS SHOW UP TO 500 J/KG...WITH MUCH MORE SUBDUED NUMBERS
COMING IN FROM THE OTHER MODELS (AROUND 200 J/KG ON THE RUC AND
GFS) AND LAPS ANALYSIS. 15Z SREF PROBS FOR >500 J/KG ARE UNDER 20
PERCENT. IN ADDITION...THE EXPECTED SOURCE REGION FOR CONVECTION
(ACCORDING TO THE HRRR RADAR SIMULATIONS) IS IN CENTRAL
KENTUCKY...WHERE RAIN HAS ESSENTIALLY PUT AN END TO
DESTABILIZATION. THUS...IT IS BELIEVED THAT INSTABILITY WILL BE
EXTREMELY LIMITED FOR THIS EVENT. WHILE IT IS TRUE THAT DYNAMIC
WEATHER SYSTEMS SUCH AS THIS ONE ARE CAPABLE OF DOING A LOT WITH A
LITTLE (IN TERMS OF INSTABILITY)...NEAR-ZERO VALUES ARE NOT GOING
TO SUPPORT A SEVERE WEATHER THREAT.
IT IS EXPECTED THAT...EMBEDDED WITHIN THE LARGER AREAS OF
RAIN...SOME WEAK CONVECTION MAY BE ABLE TO DEVELOP. THERE ARE
SIGNS (HRRR / SPC-WRF) OF THIS OCCURRING ALONG A PRE-FRONTAL
TROUGH WITHIN THE NEXT COUPLE HOURS...AND THEN AGAIN ALONG THE
COLD FRONT DURING THE MID TO LATE EVENING. THE DYNAMICS OF THE
SYSTEM ALONE WILL SUPPORT SOME GUSTY WINDS...EVEN OUTSIDE OF
STORMS. BEFORE THE RAIN MOVED IN...THERE WERE GUSTS TO AROUND 40
KNOTS IN THE LEXINGTON/FRANKFORT AREA OF KENTUCKY. HOWEVER...THIS
WILL BE AN EXCEPTION AND NOT A RULE. 50 KNOT WINDS ARE UP
THERE...BUT AT ABOUT 4000 FEET. IT WILL BE EXTREMELY DIFFICULT
(IF NOT IMPOSSIBLE) TO MIX TO ANYTHING THAT HIGH IN A MOIST...WARM
ADVECTING...PRECIPITATING PATTERN LIKE THIS.
ASIDE FROM A BRIEF DOWNPOUR IN A THUNDERSTORM...THE THREAT FOR
HEAVY OR PROLONGED RAINFALL HAS ENDED. TOTALS FROM THE RAIN TODAY
HAVE GENERALLY RANGED BETWEEN 1.00 AND 1.50 INCHES...NOT ENOUGH TO
GENERATE WIDESPREAD FLOODING. RISES ON A FEW RIVERS WILL BE
MONITORED (INCLUDING THE QUICK-RESPONDING OHIO BRUSH CREEK IN
ADAMS COUNTY...WHICH IS ALREADY IN FLOOD) BUT NO AREAL PRODUCTS
WILL BE NEEDED.
AS THE COLD FRONT MOVES AWAY FROM THE REGION...ADDITIONAL SHOWERS
WILL DEVELOP IN THE WRAP-AROUND COLD ADVECTION FLOW BEHIND THE
SURFACE LOW (AND ASSOCIATED WITH THE AXIS OF THE UPPER TROUGH).
ACCOUNTED FOR THIS WITH A PERIOD OF CHANCE POPS OVERNIGHT...WITH
EVERYTHING ELSE OTHERWISE TAPERED DOWN TO SLIGHT CHANCE OR DRY.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
THE UPPER TROUGH WILL BE MOVING AWAY FROM THE REGION ON WEDNESDAY
MORNING...BRINGING AN END TO PRECIPITATION NOT LONG AFTER THE
START OF THE FORECAST PERIOD. AN EXTENSIVE AREA OF HIGH PRESSURE
WILL THEN BUILD INTO THE EASTERN HALF OF THE COUNTRY...REMAINING
IN PLACE THROUGH THE END OF THE WEEK.
MODEL RH DEPICTIONS...EVEN WHEN CONSIDERING ALL LAYERS OF THE
ATMOSPHERE...ARE COMING IN QUITE DRY WITH THIS HIGH AND ITS
ASSOCIATED UPPER RIDGE. WILL KEEP SKY GRIDS IN THE CLEAR TO MOSTLY
CLEAR RANGE. THE FIRST CLEAR NIGHT (WEDNESDAY NIGHT) LOOKS TO BE
THE COLDEST...WITH SUB-FREEZING TEMPERATURES EXPECTED IN GOOD
RADIATIONAL COOLING CONDITIONS. TEMPERATURES SHOULD GRADUALLY
MODERATE THROUGH THE REST OF THE PERIOD...WITH NO MAJOR
DIFFERENCES DETECTED IN THE VARIOUS MODEL NUMBERS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE LONG TERM WILL START OUT DRY WITH HIGH PRESSURE ACROSS THE
AREA. WITH WARM SOUTHERLY FLOW ACROSS THE REGION TEMPERATURES WILL
BE WELL ABOVE NORMAL FOR FRIDAY AND SATURDAY. HIGH TEMPERATURES
WILL BE IN THE 60S ACROSS MOST LOCATIONS. A STRONG LOW PRESSURE
SYSTEM WILL APPROACH THE AREA SATURDAY EVENING AND WILL IMPACT THE
AREA THROUGH THE END OF THE LONG TERM PERIOD. THERE ARE SOME MODEL
TIMING DIFFERENCES HOWEVER THE LATEST ECMWF HAS COME INTO PRETTY
GOOD AGREEMENT WITH THE GFS. DUE TO THIS AGREEMENT WENT WITH A
BLEND. RAIN WILL BEGIN TO MOVE INTO THE AREA SATURDAY EVENING AND
WILL BE WIDESPREAD ACROSS THE AREA ON SUNDAY. THE UPPER LOW BECOMES
CUT OFF BY SUNDAY AND LINGERS NEAR THE AREA THROUGH THE MIDDLE OF
NEXT WEEK. THIS WILL ALLOW FOR PRECIPITATION TO LINGER ACROSS THE
AREA AS WELL. COLDER AIR WORKING INTO THE AREA WILL ALLOW FOR SOME
SNOW SHOWER ACTIVITY TO MIX IN AS WELL MONDAY NIGHT INTO TUESDAY.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
LOW PRESSURE OVER SE ILLINOIS WILL TRACK NE TO WEST CENTRAL OHIO
THIS EVENING. THE LOW WILL THEN CONTINUE ENE TO A POSITION NEAR CNTRL
PENNSYLVANIA BY WEDNESDAY MORNING. A WARM FRONT WILL LIFT N INTO
THE REGION THIS AFTERNOON/EVENING...FOLLOWED BY A COLD FRONT.
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS WILL BECOME MORE
SCATTERED IN NATURE SOUTH OF THE WARM FRONT FROM MID AFTERNOON
INTO EARLY EVENING. SOME SHOWER ACTIVITY IS EXPECTED ALONG AND
AHEAD OF THE COLD FRONT...BUT ITS COVERAGE IS STILL SOMEWHAT
UNCERTAIN ATTM. FORECAST DILEMMA REVOLVES AROUND CIGS/VSBYS.
IFR/LIFR CIGS SHOULD LIFT BRIEFLY TO MVFR CIGS IN THE WARM
SECTOR...THEN BECOME IFR ONCE AGAIN BEHIND THE COLD FRONT IN THE
CAA. VSBYS WILL BE LOCALLY IFR WITH HEAVY RAIN ALONG AND NORTH OF
THE WARM FRONT...THEN MAINLY MVFR IN ANY SHOWERS ALONG AND AHEAD
OF THE COLD FRONT. SOME SHOWER ACTIVITY MAY OCCUR ACRS CNTRL OHIO
LATE TONIGHT ALONG A TROF AXIS. HAVE HANDLED THIS WITH A VCSH
MENTION. AS THE LOW PULLS AWAY FROM THE REGION WEDNESDAY MORNING
AND AFTERNOON...HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE
WEST. SIGNIFICANT DRYING IS EXPECTED AND THUS...IFR CIGS WILL
SCATTERED OUT AND BECOME CLEAR FROM WEST TO EAST BETWEEN 15Z AND
21Z WEDNESDAY.
WINDS WILL BE GUSTY IN THE WARM SECTOR AND BEHIND THE COLD FRONT.
HAVE GUSTS OF 25 TO 30 KNOTS...BUT OBSERVATIONS WILL HAVE TO BE
WATCHED SHOULD GUSTS BECOME HIGHER IN THE MORE UNCERTAIN WARM
SECTOR THIS AFTERNOON INTO EARLY THIS EVENING.
OUTLOOK...MVFR CIGS/VSBYS POSSIBLE SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...NOVAK
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
337 PM EST TUE NOV 22 2011
.SYNOPSIS...
LOW PRESSURE OVER INDIANA WILL MOVE EAST ACROSS THE REGION TONIGHT
AND OFF THE NEW ENGLAND COAST ON WEDNESDAY. HIGH PRESSURE WILL
BUILD OVER THE REGION FOR THANKSGIVING DAY. THE HIGH PRESSURE AREA
WILL SETTLE SOUTHWARD OVER THE SOUTHEAST STATES INTO THE FIRST
PART OF THE WEEKEND AND PROVIDE FAIR MILD WEATHER. &&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE SYNOPTIC RAIN SHIELD HAS PROGRESSED INTO NW PA WHILE THE
SOUTHERN EDGE OF THE SHIELD IS MOVING INTO THE SOUTHWESTERN
COUNTIES NEAR MNN. THE DRY SLOT SHOULD PROGRESS ACROSS THE CENTRAL
AND EASTERN COUNTIES WHILE NW OHIO REMAINS MORE IN THE DEFORMATION
ZONE WITH STEADIER RAIN. WILL TAPER POPS THROUGH THE EVENING.
UNTIL ABOUT 04Z IN THE SOUTHERN AND EASTERN COUNTIES THERE IS A
SLIGHT CHANCE OF THUNDER AS INDICATED BY THE NAM AND HRRR WITH A FEW
HUNDRED JOULES OF ELEVATED CAPE. WILL MENTION A SLIGHT CHANCE OF
THUNDER UNTIL NEAR MIDNIGHT. EXPECT TEMPERATURES TO RISE THIS
EVENING AND REACH A MAX BEFORE MIDNIGHT AS THE WARM SECTOR OF THE
LOW PRESSURE AREA OVERSPREADS THE SOUTHERN AND EASTERN COUNTIES.
COLD ADVECTION WILL LOWER TEMPERATURES IN THE WAKE OF THE LOW BY
12Z. HAVE USED MAV GUIDANCE TEMPERATURES WITH MINOR CHANGES.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
ON WEDNESDAY LINGERING SHOWERS FROM THE EXITING LOW PRESSURE OVER
PA WILL QUICKLY MOVE OUT OF THE AREA DURING THE MORNING WITH
CLEARING MOVING IN RATHER QUICKLY. HAVE CHANCE POPS IN THE EAST
THIRD EARLY WITH DRY CONDITIONS BY AFTERNOON OVER THE ENTIRE CWA.
TEMPERATURES WILL RISE LITTLE IN THE EAST DUE TO LATER CLEARING
WHILE READINGS NEAR TOL WILL RECOVER TO NEAR 50.
THEN GENERALLY CLEAR WEATHER IS EXPECTED INTO THE WEEKEND WITH
GRADUALLY WARMING CONDITIONS. TEMPERATURES WILL BE SLIGHTLY ABOVE
NORMAL ON THANKSGIVINGS DAY AND WELL ABOVE NORMAL ON FRIDAY. HAVE
USED MAV/MET TEMPERATURES WITH SLIGHT ADJUSTMENTS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
WEEKEND WILL START OFF DRY AND MILD AS SOUTH TO SOUTHWEST FLOW
DEVELOPS AHEAD OF THE NEXT STORM SYSTEM. LOW PRESSURE IS PROGGED TO
MOVE NORTHEAST TO THE CENTRAL UNITED STATES FORCING A WARM FRONT
NORTH OF THE AREA. THE LOW WILL MOVE NORTHEAST TO ILLINOIS AND
INDIANA WHERE IT WILL STALL. THE SYSTEM WILL SPREAD RAIN INTO THE
REGION SATURDAY NIGHT AND CONTINUE INTO TUESDAY. THE LOW WILL THEN
MOVE NORTHEAST TO EASTERN LAKE ERIE BY TUESDAY AFTERNOON ALLOWING
COLD AIR ADVECTION TO TAKE PLACE. MODELS SUGGEST COLD AIR WILL BE
STRONG ENOUGH THAT SOME SNOW COULD MIX IN WITH THE RAIN BY LATE
TUESDAY AFTERNOON. WILL HOLD OFF ON MENTIONING SNOW AT THIS TIME DUE
TO TIMING ISSUES. COLD AIR ADVECTION MAY NOT ACTUALLY ARRIVE UNTIL
LATER TUESDAY NIGHT.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
RAIN QUICKLY SPREAD INTO THE REGION THIS MORNING AND EARLY
AFTERNOON QUICKLY CAUSING CEILINGS TO DROP DOWN TO IFR LEVELS.
VISIBILITIES BETWEEN IFR AND MVFR ARE ALSO OCCURRING IN THE RAIN.
MODERATE RAIN WILL CONTINUE TO SPREAD NORTH INTO THE REGION
THIS AFTERNOON. GFS MODEL INDICATES DRY SLOT WILL TRY TO WORK ITS
WAY NORTH INTO THE REGION THIS EVENING AND THIS SHOULD HELP TO CUT
SOME OF THE RAIN OFF FROM WEST TO EAST. LOW IS EXPECTED TO TRACK
NORTHEAST OVER THE REGION AND WE SHOULD SEE WINDS SHIFTING
GRADUALLY FROM A SOUTHEAST DIRECTION TO A NORTHWEST DIRECTION FROM
WEST TO EAST. IT WILL TAKE A LOT LONGER TO SEE A RETURN BACK TO
VFR CONDITIONS IN THE EAST COMPARED TO THE WEST TOMORROW.
OUTLOOK...NON VFR SUNDAY.
&&
.MARINE...
THE LOW IN SOUTHERN INDIANA IS EXPECTED TO TRACK NE TOWARD ERIE THEN
EAST ACROSS PA TONIGHT AND WED MORNING. EAST WINDS SHOULD INCREASE
TO ABOUT 30 KNOTS THEN BACK TO NORTH THEN NW THROUGH WED MORNING
BEFORE STARTING TO DIMINISH. THE SCA CONDITIONS SHOULD END BY LATE
WED EVENING BUT THEY WILL PROBABLY REDEVELOP BY EARLY FRI MORNING AS
A SW FLOW INCREASES FOR A WHILE BEFORE DIMINISHING SOME BY LATE IN
THE DAY FRI.
MAINLY A SOUTH FLOW IS EXPECTED SAT AND MUCH OF SUN BUT DOES NOT
LOOK STRONG ENOUGH FOR A SCA.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST WEDNESDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...REL
NEAR TERM...REL
SHORT TERM...
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
958 AM EST TUE NOV 22 2011
.SYNOPSIS...
A WARM FRONT WILL LIFT INTO NORTHERN OHIO TODAY AS DEEPENING LOW
PRESSURE MOVES UP THE LOWER OHIO RIVER VALLEY. THIS AREA OF LOW
PRESSURE WILL MOVE OVER NORTHERN OHIO TUESDAY EVENING AND DRAG A
COLD FRONT ACROSS THE REGION. HIGH PRESSURE WILL BUILD IN FOR
THANKSGIVING DAY AND REMAIN THE DOMINANT FEATURE INTO FRIDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST FOR TODAY IS ON TRACK WITH ONLY MINOR CHANGES PLANNED AS
RAIN OVERSPREADS THE ENTIRE AREA BY EVENING. HEAVIER RAIN IS JUST
NOW MOVING INTO THE SOUTHWEST PART OF THE CWA WHICH IS IN GOOD
AGREEMENT WITH HRRR MODEL AND LOCAL MESOSCALE MODEL. HAVE MADE
ONLY MINOR CHANGES TO HOURLY POPS OVER THE NE PART OF THE AREA.
WILL LOWER MAX TEMPERATURES JUST A BIT TO REFLECT THE IMPENDING
RAIN AND CONTINUED OVERCAST SKIES. WILL USE THE MAV GUIDANCE WITH
SLIGHT ADJUSTMENT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
TEMPERATURES SHOULD HOLD STEADY OR WARM SLIGHTLY ACROSS THE
EASTERN HALF OF THE REGION THROUGH THE EVENING. THIS AS LOW
PRESSURE MOVES ACROSS NORTHERN OHIO. THE ENTIRE REGION SHOULD BE
SEEING PERIODS OF RAIN INTO THE OVERNIGHT HOURS. STILL SOME
UNCERTAINTY ABOUT WHETHER THE WARM SECTOR WILL GET INTO THE CWA.
AT THIS POINT IT APPEARS IT MAY GET AS FAR NORTH AS A MARION TO
KYNG LINE. HAVE ADDED SOME SCATTERED THUNDERSTORMS TO THE FORECAST
FOR THIS AREA FOR THE EVENING. THE THUNDERSTORMS WILL BRING HIGHER
RAINFALL RATES WITH THEM AND COULD LEAD TO SOME FLOODING ISSUES.
STILL ENOUGH UNCERTAINTY IN THE TRACK OF THE LOW TO NOT GO WITH A
FLOOD WATCH AT THIS TIME BUT LATER SHIFTS WILL NEED TO MONITOR
THIS POTENTIAL CLOSELY. WILL PLACE A MENTION OF LOCALLY HEAVY
RAINFALL AND MINOR FLOODING POTENTIAL IN THE HWO.
THE MAIN AREA OF RAIN WILL END FROM WEST TO EAST THROUGH
WEDNESDAY MORNING. THERE WILL BE SOME LINGERING SHOWERS FOR A FEW
HOURS IN THE WAKE OF THE FRONT. 8H TEMPERATURES ONLY DIP TO AROUND
ZERO SO THERE SHOULD NOT BE ALL THAT MUCH OFF OF LAKE ERIE BUT MAY
KEEP SPRINKLES GOING FOR INLAND NW PA INTO WEDNESDAY EVENING.
HIGH PRESSURE WILL TAKE CONTROL ON THURSDAY AND REMAIN THE
DOMINANT FEATURE INTO FRIDAY. HIGHS WILL RETURN TO NEAR OR SLIGHT
ABOVE SEASONAL LEVELS ON THURSDAY. FRIDAY WILL BE EVEN WARMER WITH
MANY LOCATIONS NEAR OR SLIGHTLY ABOVE 60 DEGREES.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
BOTH MODELS KEEP HIGH PRESSURE OVER THE AREA ON SATURDAY...BUT
DIVERGE AFTER THAT. BOTH MODELS ARE A LITTLE SLOWER THAN YESTERDAY
BUT ECMWF MOVES LOW PRESSURE SYSTEM ACROSS THE AREA ON SUNDAY
WHILE THE GFS CONTINUES TO HOLD THE SYSTEM BACK UNTIL MONDAY. FOR
FORECAST JUST KEPT CHANCE POPS GOING SUNDAY THROUGH MONDAY AS
CONFIDENCE IN THE EXACT TIMING OF THE SYSTEM IS LOW.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
LOW PRESSURE SYSTEM OVER ARKANSAS WILL MOVE ACROSS OHIO THIS
EVENING. RAIN SHIELD AHEAD OF LOW ALREADY INTO SW OH AND WILL
SPREAD OVER ENTIRE AREA BY EARLY AFTERNOON. ONCE STEADY RAIN
STARTS WILL CONTINUE INTO THE OVERNIGHT HOURS. A WIDESPREAD INCH
OF RAIN IS POSSIBLE NEXT 24 HOURS. AS RAIN SPREADS OVER THE AREA
SO WILL WIDESPREAD IFR CONDITIONS. 300-500 FT CIGS ALREADY MOVING
INTO CENTRAL OHIO. IN ADDITION E-NE WINDS WILL INCREASE TO AROUND
15G25KT BY LATE AFTERNOON/EARLY EVENING. FINALLY...DID NOT MENTION
IN TAF BUT FEW RUMBLES OF THUNDER PROBABLE SOUTH OF A YNG TO FDY
LINE LATE THIS AFTERNOON INTO EARLY EVENING.
OUTLOOK...NON VFR CONDITIONS WILL PERSIST INTO WEDNESDAY AM.
&&
.MARINE...
LOW PRESSURE SYSTEM NOW OVER ARKANSAS WILL TRACK ACROSS OHIO
TONIGHT. THE NAM STILL HAS THE TRACK OF THE LOW FURTHER NORTH THAN
EITHER GFS OR ECMWF. EXPECT WINDS TO INCREASE TO 30 KNOTS BY THIS
TIME TOMORROW...ALTHOUGH A MARGINAL GALE IS NOT OUT THE QUESTION FOR
A FEW HOURS. HIGH PRESSURE BUILDS IN WEDNESDAY AFTERNOON AND
REMAINS IN CONTROL THROUGH SATURDAY. A SOUTH TO SOUTHWEST FLOW
SETS UP THURSDAY AND CONTINUES THROUGH SATURDAY. MODELS DISAGREE ON
TIMING OF NEXT LOW PRESSURE SYSTEM. THE ECMWF MOVES THE SYSTEM
THROUGH ON SUNDAY...WHILE THE GFS HOLDS IT BACK UNTIL MONDAY. FOR
WIND AND WAVE FORECAST LEANED TOWARD THE SLOWER GFS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST WEDNESDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...MULLEN
NEAR TERM...REL
SHORT TERM...MULLEN
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
418 PM CST TUE NOV 22 2011
.SHORT TERM...
HAD ANOTHER DAY WITH LOW CLOUDS OVER AT LEAST SOME OF OUR AREA
TODAY. LOW CLOUD FIELD HAS PERSISTED ACROSS THE BIG COUNTRY...
THOUGH LATEST VISIBLE SATELLITE TRENDS SHOWING EROSION TO THE
NORTHWEST AND A HALT TO THE SOUTHWARD EXPANSION.
THE NAM AND RUC BOUNDARY LAYER MOISTURE FIELDS SUGGEST A LOW
CLOUD PERSISTENCE AND DEVELOPMENT TO THE SOUTH TONIGHT...ESPECIALLY
ACROSS OUR EASTERN COUNTIES. DEWPOINTS HAVE NOT DROPPED AS MUCH
TODAY AS PREVIOUSLY EXPECTED. A LACK OF DRY AIR ADVECTION IS
INDICATED TONIGHT. AS RADIATIONAL COOLING OCCURS OVERNIGHT...AT
LEAST PATCHY FOG DEVELOPMENT IS ANTICIPATED. THE BEST CHANCE FOR
FOG DEVELOPMENT IS ACROSS THE CLOUD FREE AREAS. THE EXCEPTION WHOULD
BE ACROSS THE SOUTHWESTERN PART OF OUR AREA WHERE THE DRIEST AIR
RESIDES. NORTH WINDS WILL DECREASE THIS EVENING AND BECOME LIGHT FOR
MUCH OF THE NIGHT. THE UPS FOG TOOL INDICATES A FAVORABLE SETUP FOR
THE DEVELOPMENT OF FOG ACROSS OUR CENTRAL COUNTIES. WITH THE
ABOVE CONSIDERATIONS...CARRYING A MENTION OF SOME CLOUDINESS
TONIGHT AND EARLY FRIDAY MORNING. PATCHY FOG IS MENTIONED ACROSS
THE BIG COUNTRY AND NORTHWEST HILL COUNTRY...WITH AREAS OF FOG
FROM THE CONCHO VALLEY EAST ACROSS THE HEARTLAND.
HAVE NOT YET MENTIONED DENSE FOG IN THE FORECAST...AND THIS IS
SOMETHING WHICH WILL BEAR MONITORING.
THE FOG WILL LIFT QUICKLY BY MID-MORNING WEDNESDAY WITH LOW
CLOUD BREAKUP...AND SKIES WILL BE SUNNY DURING THE AFTERNOON.
OVERNIGHT LOWS WILL BE IN THE UPPER 30S TO LOWER 40S...WITH
AFTERNOON HIGHS WEDNESDAY IN THE UPPER 60S TO LOWER 70S.
&&
.LONG TERM..
SHORT WAVE RIDGING MOVES EAST OF THE AREA WEDNESDAY NIGHT WITH
SOUTHWEST FLOW ALOFT DEVELOPING AHEAD OF NEXT SOUTHWEST CONUS
TROUGH. THANKSGIVING DAY WILL BE MOSTLY SUNNY BUT BREEZY AS SOUTH
WINDS INCREASE WITH LEE TROUGH DEVELOPING. TEMPERATURES WILL BE
ABOVE NORMAL WITH AFTERNOON HIGHS IN THE LOWER 70S. MODELS ARE IN
DECENT AGREEMENT THAT THE SYSTEM TO THE WEST WILL CLOSE OFF OVER THE
NORTHERN BAHA REGION ON THURSDAY...THEN LIFT NORTHEAST AS AN OPEN
WAVE AS IT CROSSES THE ROCKIES AND INTO THE PLAINS ON FRIDAY. THE
GFS AND ECMWF BOTH PAINT QPF OVER THE ENTIRE AREA BEGINNING OVER
WESTERN ZONES LATE FRIDAY INTO FRIDAY NIGHT. MADE SLIGHT CHANGES TO
POPS...MAINLY TO SHIFT POPS WESTWARD ON FRIDAY WITH THE BULK OF
PRECIPITATION OCCURRING FRIDAY EVENING AND DURING THE OVERNIGHT
HOURS.
UPPER TROUGH MOVES EAST OF THE AREA ON SATURDAY WITH A STRONG COLD
FRONT DROPPING SOUTH ACROSS THE REGION DURING THE DAY. MODEL PROGS
SHOW THE COLD FRONT ENTERING THE BIG COUNTRY AROUND DAYBREAK SATURDAY
WITH THE FRONT RACING SOUTH ACROSS THE REMAINDER OF THE AREA DURING
THE MORNING HOURS. VERY IMPRESSIVE WIND FIELDS SHOWING UP ON THE
LATEST GFS WITH 850 MB WINDS FROM THE NORTH AT 40 TO 50 KT BEHIND
THE FRONT. STRONG COLD AIR ADVECTION AND ALIGNMENT OF NORTHERLY
WINDS THROUGH 700 MB WILL RESULT IN A VERY WINDY DAY ACROSS THE
AREA WITH GUSTS 40 TO 50 MPH POSSIBLE. CURRENTLY HAVE HIGHS ON
SATURDAY IN THE MID AND UPPER 50S AND THESE MAY NEED TO BE LOWERED
A BIT MORE IN SUBSEQUENT FORECASTS. WINDS DIMINISH SATURDAY
EVENING WITH A COLD NIGHT IN STORE SATURDAY NIGHT. CURRENT LOWS
ARE NEAR FREEZING BUT AGAIN THESE TEMPS MAY NEED TO BE LOWERED AS
WELL. DRY WITH A WARMING TREND SUNDAY INTO MONDAY. HIGHS ON SUNDAY
WILL CONTINUE TO BE COOL WITH HIGHS IN THE UPPER 50S AND LOW 60S.
WARMER MONDAY WITH HIGHS IN THE 60S. NEXT COLD FRONT IS EXPECTED
MONDAY NIGHT OR TUESDAY WITH COOLER TEMPERATURES FOLLOWING THE
FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 40 70 46 72 52 / 0 0 0 0 10
SAN ANGELO 39 71 43 71 50 / 0 0 0 0 10
JUNCTION 39 72 39 73 54 / 0 0 0 0 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
19/24
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
1214 PM CST TUE NOV 22 2011
.DISCUSSION...
SEE AVIATION SECTION.
&&
.AVIATION...
LOW CLOUD FIELD WHICH COVERS ROUGHLY THE NORTHERN THIRD OF OUR
COUNTIES IS MOVING SLOWLY SOUTHWARD...WITH LEADING EDGE AT 1745Z
EXTENDING FROM JUST NORTH OF STERLING CITY TO SAN SABA. CEILINGS
ARE IN THE RANGE OF 800-1200 FT. HOW FAR SOUTH THIS CLOUD FIELD
WILL PROGRESS AND HOW PERSISTENT IT WILL REMAIN IS UNCERTAIN AT
THIS TIME. THE LATEST RUC13 MODEL BOUNDARY LAYER MOISTURE FIELD
SUGGESTS A POSSIBILITY OF PATCHY LOW CLOUDS PERSISTING THROUGH
03Z.
FOR THE 18Z TAF PAKCAGE HAVE INTRODUCED LOW CLOUDS AT KSJT AND
KBBD THIS AFTERNOON...AND HAVE CARRIED A PERSISTENCE OF LOW CLOUDS
LONGER AT KABI. WILL CONTINUE TO MONITOR SATELLITE IMAGERY AND
AMEND AS NEEDED. FOR TONIGHT...POTENTIAL EXISTS FOR FOG
DEVELOPMENT WITH GOOD RADIATIONAL COOLING AND NOT MUCH DROPOFF OF
THE DEWPOINTS. HAVE NOT INTRODUCED FOG YET...BUT THIS IS BEING
CONSIDERED. NORTH-NORTHWEST WINDS WILL DECREASE BY THIS EVENING
WITH LIGHT NORTH WINDS EXPECTED TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 536 AM CST TUE NOV 22 2011/
DISCUSSION...
/SEE BELOW FOR AVIATION DISCUSSION/
AVIATION...
LIFR CIGS AND VISIBILITIES SHOULD IMPROVE TO IFR AT KABI BY
15Z...AS DRIER NORTHWEST AIR OF 5 TO 10 KTS MOVES IN. SHOULD TAKE
UNTIL 19Z FOR IFR CIGS TO LIFT TO MVFR HOWEVER. IFR CIGS AT KBDD
SHOULD LIFT TO VFR BY 14Z. CIGS AND VISIBILITIES WERE ALREADY AT
VFR AT REST OF TAF SITES...AND EXPECT VFR CONDITONS NEXT 24 HOURS
AS SURFACE HIGH PRESSURE BUILDS IN. NORTHWEST WINDS OTHERWISE TO
INCREASE TO 8 TO 10 KTS ACROSS ALL TAF SITES BY NOON.
PREV DISCUSSION... /ISSUED 348 AM CST TUE NOV 22 2011/
SHORT TERM...
UPPER LEVEL TROUGH WAS MOVING NORTHEAST OF WEST CENTRAL TEXAS
THIS MORNING. CLOUDS WERE ERODING OVER THE CONCHO VALLEY...
CROCKETT COUNTY WITH SUBSIDENCE BEHIND THE SYSTEM. LAST LINE OF
THUNDERSTORMS MOVED EAST OF THE REGION AROUND 2 AM.
THERE WERE SOME PATCHY AREAS OF DENSE FOG...SWEETWATER WAS AT 1/4
MILE AT 3 AM CST. GIVEN THE PATCHY NATURE HOWEVER...WILL NOT ISSUE
A DENSE FOG ADVISORY THIS MORNING.
DESPITE SUBSIDENCE BEHIND THE UPPER TROUGH...BOTH THE NAM AND GFS
KEEP CLOUD COVER OVER THE BIG COUNTRY...ESPECIALLY EASTERN
SECTIONS...UNTIL EARLY AFTERNOON. WILL KEEP TEMPERATURES COOLER IN
THE BIG COUNTRY WITH HIGHS NEAR 60...WITH WARMER TEMPERATURES IN
THE LOWER 70S IN THE CONCHO VALLEY AND AREAS SOUTHWARD TO THE I-10
CORRIDOR. NORTHWEST WINDS OF 5 TO 15 MPH WILL ALSO HAVE A
DOWNSLOPE COMPRESSIONAL HEATING COMPONENT OF 1 TO 2 DEGREES.
CENTER OF WEAK SURFACE HIGH PRESSURE BUILDS INTO WEST CENTRAL
TEXAS OVERNIGHT. WENT A COUPLE DEGREES COOLER...TOWARD THE COOLER
NAM MOS VALUES...GIVEN GOOD RADIATIONAL COOLING CONDITIONS.
LONG TERM...
THE UPPER LEVEL TROUGH THAT BROUGHT THUNDERSTORMS TO THE AREA
TODAY AND LAST NIGHT CONTINUES TO MOVE EAST AT THIS HOUR. BY
WEDNESDAY...UPPER LEVEL RIDGING WILL BE OVER THE AREA. BIG COUNTRY
TEMPERATURES WILL BE CONSIDERABLY WARMER BY WEDNESDAY THAN THEY
WERE TODAY...WHILE SOUTHERN AREAS WILL ACTUALLY BE COOLER DUE TO
VERY WARM TEMPERATURES EXPERIENCED TODAY. GENERALLY NEAR OR
SLIGHTLY WARMER THAN NORMAL TEMPERATURES CAN BE EXPECTED THROUGH
FRIDAY.
BY FRIDAY...AN UPPER LEVEL LOW OVER THE AZ/NM AREA WILL BE OPENING
UP INTO A WAVE AS IT MOVES TOWARD TX. MODELS ARE IN FAIRLY GOOD
AGREEMENT WITH THE GENERAL PATH OF THIS LOW ACROSS THE SOUTHERN
PLAINS...BRINGING OUR NEXT CHANCE OF RAINFALL. THE DIFFERENCES
BETWEEN THE MODELS IS IN THE SPEED OF THE TROUGH...AND WHEN IT
WILL AFFECT THE AREA. THE EC IS A LITTLE SLOWER WITH THE SPEED OF
THE TROUGH MOVING ACROSS THE AREA...SO HAVE HELD UP POPS/WX A TAD
FRIDAY NIGHT INTO SATURDAY MORNING. THE BEST CHANCE FOR
SIGNIFICANT RAINFALL WILL MAINLY LIE IN AREAS EAST OF A LINE FROM
ABILENE...TO JUNCTION. WE WILL STILL HAVE A CHANCE WEST OF THAT
LINE...BUT RAINFALL AMOUNTS...SHOULD ANY OCCUR...WILL INCREASE AS
ONE MOVES EAST.
TEMPERATURES SATURDAY WILL LIKELY BE COOLER THAN NORMAL...AND HAVE
KEPT THAT TREND GOING WITH DRY WEATHER THROUGH EARLY NEXT WEEK.
ANOTHER PIECE OF ENERGY IS EXPECTED TO FOLLOW THE FRIDAY
NIGHT/SATURDAY MORNING TROUGH...POSSIBLY SENDING ANOTHER SHOT OF
COLD AIR INTO THE AREA MONDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 55 39 70 44 72 / 0 0 0 0 0
SAN ANGELO 69 37 71 43 72 / 0 0 0 0 0
JUNCTION 73 37 72 40 74 / 10 0 0 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1148 AM CST TUE NOV 22 2011
.DISCUSSION...PLEASE SEE 18Z AVIATION DISCUSSION.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD.
CLEARING BEHIND THE COLD FRONT WILL CONTINUE TO TAKE PLACE THROUGH
THE EARLY AFTERNOON. OTHERWISE...NORTHWEST WINDS WILL GUST TO
NEAR 20-25 KNOTS THROUGH THE AFTERNOON...WITH WINDS SUBSIDING IN
THE EARLY EVENING SHIFTING OUT OF THE NORTH TO NORTHEAST AS HIGHER
PRESSURE MOVES IN.
&&
.PREV DISCUSSION... /ISSUED 1030 AM CST TUE NOV 22 2011/
DISCUSSION...MADE UPDATES TO THE WINDS AND POPS DUE TO THE COLD
FRONT MOVING A BIT FASTER THAN PREVIOUSLY EXPECTED. A WIND SHIFT
OUT OF THE SOUTHWEST EARLY THIS MORNING CREATED SOME DRYING IN THE
MIDLEVELS. WITH THIS CAPPING...REMOVED MENTION OF THUNDER WITH
THE EXCEPTION OF THE IMMEDIATE COAST AND THE GULF WATERS. STILL
EXPECT THAT WITH HEATING PRIOR TO THE FRONTAL PASSAGE AND DECENT
CAPE...COULD SEE AN ISOLATED THUNDERSTORM DEVELOP AS THE FRONT
APPROACHES THE COAST EARLY THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 551 AM CST TUE NOV 22 2011/
DISCUSSION...UPDATED FOR 12Z AVIATION DISCUSSION BELOW.
AVIATION...MAIN FLIGHT CONCERNS TO BE PRECIP CHANCES AND LOW CIGS.
XPCT MIX OF MVFR/VFR CIGS THRU EARLY AFTN FOLLOWED BY CLEARING
SKIES. SCT SHRA THRU EARLY AFTN VCT VCNTY WITH SLIGHTLY LESSER
CHANCES CRP/ALI...KLRD LIKELY TO REMAIN DRY. PRECIP TO BE INVOF
SURFACE BOUNDARY THAT WILL PUSH THROUGH S TX TODAY WITH LIGHT S
WINDS AHEAD OF BOUNDARY BCMG NNW BEHIND. CLEARING SKIES THIS AFTN
AT KLRD FIRST WITH CLEARING LINE PROGRESSING FROM WEST TO EAST.
LIGHT TO MODERATE NE WINDS AFTER DARK WITH MAINLY CLEAR SKIES ALL
TERMINALS.
PREV DISCUSSION... /ISSUED 423 AM CST TUE NOV 22 2011/
SHORT TERM (TODAY THROUGH WEDNESDAY)...CHANCES OF RAIN ARE
BIGGEST CHALLENGE FOR SHORT TERM FORECAST. EARLY THIS MORNING A
COLD FRONT WAS DRAPED FROM EAGLE PASS TO THE NORTHEAST ACROSS THE
HILL COUNTRY WITH A TROUGH OF LOW PRESSURE FROM EAGLE PASS
SOUTHWARD INTO NE OLD MEX. A LINE OF SHOWERS AND THUNDERSTORMS HAS
DEVELOPED ALONG THE COLD FRONT WITH THE LINE GRADUALLY PROGRESSING
EASTWARD. AM EXPECTING THIS LINE TO GRADUALLY WEAKEN THROUGH THE
REMAINDER OF THE NIGHT AS IT APPROACHES CWA. FORECAST SOUNDINGS
INDICATE CAPPING INVERSION TO EXIST ACROSS WESTERN 2/3 OF AREA AND
THUS EXPECT BEST PRECIP CHANCES TODAY TO EXIST ACROSS NE ZONES AND
EASTERN COASTAL PLAINS. LATEST 4KM WRF AND HRRR GUIDANCE BRINGS A
LINE OF SHOWERS AND ISOLATED THUNDERSTORMS THROUGH EASTERN ZONES
THIS MORNING WITH LINE PUSHING OFF COAST AROUND MIDDAY/EARLY
AFTERNOON AND SEE NO STRONG INDICATIONS TO DISCOUNT THIS GUIDANCE
ATTM. STRONG STORM POTENTIAL IS LOOKING LESS LIKELY THAN EARLIER
GUIDANCE RUNS INDICATED AS LOW LEVEL WINDS VEER TOO STRONGLY AND
COOLING OF MID LEVEL TEMPS TO BE SLOWER THAN PREVIOUSLY THOUGHT.
IF ANY STRONG STORMS DEVELOP THEY SHOULD BE VERY ISOLATED AT BEST
AND ACROSS NE ZONES. SURFACE TROUGH TO SLIDE EASTWARD TODAY WITH
WINDS SHIFTING NWRLY BEHIND BOUNDARY AS SIGNIFICANTLY DRIER AIR
WORKS INTO S TX. MAIN SURFACE FRONT TO SLIDE THROUGH S TX LATE
AFTERNOON WITH WINDS BECOMING MORE NNERLY. ANOTHER DAY OF
UNSEASONABLY WARM TEMPS TODAY BEFORE MAX/MIN TEMPS FALL TO
SEASONABLE LEVELS TONIGHT THROUGH WED AS HIGH PRESSURE BUILDS
INTO CWA.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...OVERALL NOT A LOT OF
CHANGES (MAIN ONES TO FALL IN LINE WITH ISC). QUIET WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT WITH MOISTURE RETURNING LATE THURSDAY IN TIME
FOR THE NEXT UPPER LEVEL TROUGH COMING ACROSS LATE FRIDAY.
INTERESTING THAT 00Z ECMWF IS BACK TO CUTTING OFF PART OF THE UPPER
LOW THIS WEEKEND AND RETROGRADING IT AGAIN (AFTER NOT DOING SO ON
ITS 12Z RUN). THUS...AM AGAIN RELYING MORE ON THE GFS SOLUTION WITH
THIS SYSTEM...AND PRETTY MUCH KEEPING THE SAME POPS (DID GO A BIT
HIGHER FARTHER SOUTH FRIDAY/FRIDAY NIGHT). SOME RAINS COULD LINGER
FOR A SHORT TIME SATURDAY MORNING...BUT SHOULD BE CLEARER...WINDY
AND COOLER FOR SATURDAY AFTERNOON WITH CRITICAL FIRE WEATHER
CONDITIONS PROBABLE....AND WINDS NEAR GALE FORCE OVER THE OFFSHORE
WATERS. THIS COULD BE THE COLDEST AIRMASS SO FAR THIS YEAR AS STRONG
HIGH MOVES INTO SOUTHERN PLAINS. HOWEVER...WINDS WILL STAY UP ENOUGH
SO THAT TEMPERATURES SUNDAY MORNING WILL NOT BE TERRIBLY COLD
(MONDAY WILL BE THE COLDEST MORNING...WITH SUNDAY BEING THE COLDEST
DAY). AIRMASS MODIFIES ON MONDAY AHEAD OF ANOTHER FRONT POSSIBLE
EARLY TUESDAY MORNING. NOT MUCH ELSE TO SAY...SUBTLE CHANGES TO
PREVIOUS TEMPERATURE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 55 76 54 78 66 / 10 0 0 10 10
VICTORIA 49 74 46 77 61 / 0 0 0 10 10
LAREDO 54 78 55 82 64 / 0 0 0 10 10
ALICE 54 78 51 80 63 / 0 0 0 10 10
ROCKPORT 55 72 56 75 66 / 10 0 0 10 10
COTULLA 49 76 49 79 58 / 0 0 0 10 10
KINGSVILLE 54 76 51 78 64 / 10 0 0 10 10
NAVY CORPUS 58 72 59 74 68 / 10 0 0 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
CB/85...AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1030 AM CST TUE NOV 22 2011
.DISCUSSION...MADE UPDATES TO THE WINDS AND POPS DUE TO THE COLD
FRONT MOVING A BIT FASTER THAN PREVIOUSLY EXPECTED. A WIND SHIFT
OUT OF THE SOUTHWEST EARLY THIS MORNING CREATED SOME DRYING IN THE
MIDLEVELS. WITH THIS CAPPING...REMOVED MENTION OF THUNDER WITH
THE EXCEPTION OF THE IMMEDIATE COAST AND THE GULF WATERS. STILL
EXPECT THAT WITH HEATING PRIOR TO THE FRONTAL PASSAGE AND DECENT
CAPE...COULD SEE AN ISOLATED THUNDERSTORM DEVELOP AS THE FRONT
APPROACHES THE COAST EARLY THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 551 AM CST TUE NOV 22 2011/
DISCUSSION...UPDATED FOR 12Z AVIATION DISCUSSION BELOW.
AVIATION...MAIN FLIGHT CONCERNS TO BE PRECIP CHANCES AND LOW CIGS.
XPCT MIX OF MVFR/VFR CIGS THRU EARLY AFTN FOLLOWED BY CLEARING
SKIES. SCT SHRA THRU EARLY AFTN VCT VCNTY WITH SLIGHTLY LESSER
CHANCES CRP/ALI...KLRD LIKELY TO REMAIN DRY. PRECIP TO BE INVOF
SURFACE BOUNDARY THAT WILL PUSH THROUGH S TX TODAY WITH LIGHT S
WINDS AHEAD OF BOUNDARY BCMG NNW BEHIND. CLEARING SKIES THIS AFTN
AT KLRD FIRST WITH CLEARING LINE PROGRESSING FROM WEST TO EAST.
LIGHT TO MODERATE NE WINDS AFTER DARK WITH MAINLY CLEAR SKIES ALL
TERMINALS.
PREV DISCUSSION... /ISSUED 423 AM CST TUE NOV 22 2011/
SHORT TERM (TODAY THROUGH WEDNESDAY)...CHANCES OF RAIN ARE
BIGGEST CHALLENGE FOR SHORT TERM FORECAST. EARLY THIS MORNING A
COLD FRONT WAS DRAPED FROM EAGLE PASS TO THE NORTHEAST ACROSS THE
HILL COUNTRY WITH A TROUGH OF LOW PRESSURE FROM EAGLE PASS
SOUTHWARD INTO NE OLD MEX. A LINE OF SHOWERS AND THUNDERSTORMS HAS
DEVELOPED ALONG THE COLD FRONT WITH THE LINE GRADUALLY PROGRESSING
EASTWARD. AM EXPECTING THIS LINE TO GRADUALLY WEAKEN THROUGH THE
REMAINDER OF THE NIGHT AS IT APPROACHES CWA. FORECAST SOUNDINGS
INDICATE CAPPING INVERSION TO EXIST ACROSS WESTERN 2/3 OF AREA AND
THUS EXPECT BEST PRECIP CHANCES TODAY TO EXIST ACROSS NE ZONES AND
EASTERN COASTAL PLAINS. LATEST 4KM WRF AND HRRR GUIDANCE BRINGS A
LINE OF SHOWERS AND ISOLATED THUNDERSTORMS THROUGH EASTERN ZONES
THIS MORNING WITH LINE PUSHING OFF COAST AROUND MIDDAY/EARLY
AFTERNOON AND SEE NO STRONG INDICATIONS TO DISCOUNT THIS GUIDANCE
ATTM. STRONG STORM POTENTIAL IS LOOKING LESS LIKELY THAN EARLIER
GUIDANCE RUNS INDICATED AS LOW LEVEL WINDS VEER TOO STRONGLY AND
COOLING OF MID LEVEL TEMPS TO BE SLOWER THAN PREVIOUSLY THOUGHT.
IF ANY STRONG STORMS DEVELOP THEY SHOULD BE VERY ISOLATED AT BEST
AND ACROSS NE ZONES. SURFACE TROUGH TO SLIDE EASTWARD TODAY WITH
WINDS SHIFTING NWRLY BEHIND BOUNDARY AS SIGNIFICANTLY DRIER AIR
WORKS INTO S TX. MAIN SURFACE FRONT TO SLIDE THROUGH S TX LATE
AFTERNOON WITH WINDS BECOMING MORE NNERLY. ANOTHER DAY OF
UNSEASONABLY WARM TEMPS TODAY BEFORE MAX/MIN TEMPS FALL TO
SEASONABLE LEVELS TONIGHT THROUGH WED AS HIGH PRESSURE BUILDS
INTO CWA.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...OVERALL NOT A LOT OF
CHANGES (MAIN ONES TO FALL IN LINE WITH ISC). QUIET WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT WITH MOISTURE RETURNING LATE THURSDAY IN TIME
FOR THE NEXT UPPER LEVEL TROUGH COMING ACROSS LATE FRIDAY.
INTERESTING THAT 00Z ECMWF IS BACK TO CUTTING OFF PART OF THE UPPER
LOW THIS WEEKEND AND RETROGRADING IT AGAIN (AFTER NOT DOING SO ON
ITS 12Z RUN). THUS...AM AGAIN RELYING MORE ON THE GFS SOLUTION WITH
THIS SYSTEM...AND PRETTY MUCH KEEPING THE SAME POPS (DID GO A BIT
HIGHER FARTHER SOUTH FRIDAY/FRIDAY NIGHT). SOME RAINS COULD LINGER
FOR A SHORT TIME SATURDAY MORNING...BUT SHOULD BE CLEARER...WINDY
AND COOLER FOR SATURDAY AFTERNOON WITH CRITICAL FIRE WEATHER
CONDITIONS PROBABLE....AND WINDS NEAR GALE FORCE OVER THE OFFSHORE
WATERS. THIS COULD BE THE COLDEST AIRMASS SO FAR THIS YEAR AS STRONG
HIGH MOVES INTO SOUTHERN PLAINS. HOWEVER...WINDS WILL STAY UP ENOUGH
SO THAT TEMPERATURES SUNDAY MORNING WILL NOT BE TERRIBLY COLD
(MONDAY WILL BE THE COLDEST MORNING...WITH SUNDAY BEING THE COLDEST
DAY). AIRMASS MODIFIES ON MONDAY AHEAD OF ANOTHER FRONT POSSIBLE
EARLY TUESDAY MORNING. NOT MUCH ELSE TO SAY...SUBTLE CHANGES TO
PREVIOUS TEMPERATURE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 87 55 76 54 78 / 30 10 0 0 10
VICTORIA 83 49 74 46 77 / 70 0 0 0 10
LAREDO 86 54 78 55 82 / 10 0 0 0 10
ALICE 88 54 78 51 80 / 30 0 0 0 10
ROCKPORT 83 55 72 56 75 / 50 10 0 0 10
COTULLA 83 49 76 49 79 / 10 0 0 0 10
KINGSVILLE 88 54 76 51 78 / 30 10 0 0 10
NAVY CORPUS 83 58 72 59 74 / 40 10 0 0 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
CB/85...UPDATE
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
551 AM CST TUE NOV 22 2011
.DISCUSSION...UPDATED FOR 12Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...MAIN FLIGHT CONCERNS TO BE PRECIP CHANCES AND LOW CIGS.
XPCT MIX OF MVFR/VFR CIGS THRU EARLY AFTN FOLLOWED BY CLEARING
SKIES. SCT SHRA THRU EARLY AFTN VCT VCNTY WITH SLIGHTLY LESSER
CHANCES CRP/ALI...KLRD LIKELY TO REMAIN DRY. PRECIP TO BE INVOF
SURFACE BOUNDARY THAT WILL PUSH THROUGH S TX TODAY WITH LIGHT S
WINDS AHEAD OF BOUNDARY BCMG NNW BEHIND. CLEARING SKIES THIS AFTN
AT KLRD FIRST WITH CLEARING LINE PROGRESSING FROM WEST TO EAST.
LIGHT TO MODERATE NE WINDS AFTER DARK WITH MAINLY CLEAR SKIES ALL
TERMINALS.
&&
.PREV DISCUSSION... /ISSUED 423 AM CST TUE NOV 22 2011/
SHORT TERM (TODAY THROUGH WEDNESDAY)...CHANCES OF RAIN ARE
BIGGEST CHALLENGE FOR SHORT TERM FORECAST. EARLY THIS MORNING A
COLD FRONT WAS DRAPED FROM EAGLE PASS TO THE NORTHEAST ACROSS THE
HILL COUNTRY WITH A TROUGH OF LOW PRESSURE FROM EAGLE PASS
SOUTHWARD INTO NE OLD MEX. A LINE OF SHOWERS AND THUNDERSTORMS HAS
DEVELOPED ALONG THE COLD FRONT WITH THE LINE GRADUALLY PROGRESSING
EASTWARD. AM EXPECTING THIS LINE TO GRADUALLY WEAKEN THROUGH THE
REMAINDER OF THE NIGHT AS IT APPROACHES CWA. FORECAST SOUNDINGS
INDICATE CAPPING INVERSION TO EXIST ACROSS WESTERN 2/3 OF AREA AND
THUS EXPECT BEST PRECIP CHANCES TODAY TO EXIST ACROSS NE ZONES AND
EASTERN COASTAL PLAINS. LATEST 4KM WRF AND HRRR GUIDANCE BRINGS A
LINE OF SHOWERS AND ISOLATED THUNDERSTORMS THROUGH EASTERN ZONES
THIS MORNING WITH LINE PUSHING OFF COAST AROUND MIDDAY/EARLY
AFTERNOON AND SEE NO STRONG INDICATIONS TO DISCOUNT THIS GUIDANCE
ATTM. STRONG STORM POTENTIAL IS LOOKING LESS LIKELY THAN EARLIER
GUIDANCE RUNS INDICATED AS LOW LEVEL WINDS VEER TOO STRONGLY AND
COOLING OF MID LEVEL TEMPS TO BE SLOWER THAN PREVIOUSLY THOUGHT.
IF ANY STRONG STORMS DEVELOP THEY SHOULD BE VERY ISOLATED AT BEST
AND ACROSS NE ZONES. SURFACE TROUGH TO SLIDE EASTWARD TODAY WITH
WINDS SHIFTING NWRLY BEHIND BOUNDARY AS SIGNIFICANTLY DRIER AIR
WORKS INTO S TX. MAIN SURFACE FRONT TO SLIDE THROUGH S TX LATE
AFTERNOON WITH WINDS BECOMING MORE NNERLY. ANOTHER DAY OF
UNSEASONABLY WARM TEMPS TODAY BEFORE MAX/MIN TEMPS FALL TO
SEASONABLE LEVELS TONIGHT THROUGH WED AS HIGH PRESSURE BUILDS
INTO CWA.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...OVERALL NOT A LOT OF
CHANGES (MAIN ONES TO FALL IN LINE WITH ISC). QUIET WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT WITH MOISTURE RETURNING LATE THURSDAY IN TIME
FOR THE NEXT UPPER LEVEL TROUGH COMING ACROSS LATE FRIDAY.
INTERESTING THAT 00Z ECMWF IS BACK TO CUTTING OFF PART OF THE UPPER
LOW THIS WEEKEND AND RETROGRADING IT AGAIN (AFTER NOT DOING SO ON
ITS 12Z RUN). THUS...AM AGAIN RELYING MORE ON THE GFS SOLUTION WITH
THIS SYSTEM...AND PRETTY MUCH KEEPING THE SAME POPS (DID GO A BIT
HIGHER FARTHER SOUTH FRIDAY/FRIDAY NIGHT). SOME RAINS COULD LINGER
FOR A SHORT TIME SATURDAY MORNING...BUT SHOULD BE CLEARER...WINDY
AND COOLER FOR SATURDAY AFTERNOON WITH CRITICAL FIRE WEATHER
CONDITIONS PROBABLE....AND WINDS NEAR GALE FORCE OVER THE OFFSHORE
WATERS. THIS COULD BE THE COLDEST AIRMASS SO FAR THIS YEAR AS STRONG
HIGH MOVES INTO SOUTHERN PLAINS. HOWEVER...WINDS WILL STAY UP ENOUGH
SO THAT TEMPERATURES SUNDAY MORNING WILL NOT BE TERRIBLY COLD
(MONDAY WILL BE THE COLDEST MORNING...WITH SUNDAY BEING THE COLDEST
DAY). AIRMASS MODIFIES ON MONDAY AHEAD OF ANOTHER FRONT POSSIBLE
EARLY TUESDAY MORNING. NOT MUCH ELSE TO SAY...SUBTLE CHANGES TO
PREVIOUS TEMPERATURE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 87 55 76 54 78 / 50 10 0 0 10
VICTORIA 83 49 74 46 77 / 70 0 0 0 10
LAREDO 86 54 78 55 82 / 10 0 0 0 10
ALICE 88 54 78 51 80 / 30 0 0 0 10
ROCKPORT 83 55 72 56 75 / 50 10 0 0 10
COTULLA 83 49 76 49 79 / 10 0 0 0 10
KINGSVILLE 88 54 76 51 78 / 30 10 0 0 10
NAVY CORPUS 83 58 72 59 74 / 40 10 0 0 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
AVIATION...HART/79
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
423 AM CST TUE NOV 22 2011
.SHORT TERM (TODAY THROUGH WEDNESDAY)...CHANCES OF RAIN ARE
BIGGEST CHALLENGE FOR SHORT TERM FORECAST. EARLY THIS MORNING A
COLD FRONT WAS DRAPED FROM EAGLE PASS TO THE NORTHEAST ACROSS THE
HILL COUNTRY WITH A TROUGH OF LOW PRESSURE FROM EAGLE PASS
SOUTHWARD INTO NE OLD MEX. A LINE OF SHOWERS AND THUNDERSTORMS HAS
DEVELOPED ALONG THE COLD FRONT WITH THE LINE GRADUALLY PROGRESSING
EASTWARD. AM EXPECTING THIS LINE TO GRADUALLY WEAKEN THROUGH THE
REMAINDER OF THE NIGHT AS IT APPROACHES CWA. FORECAST SOUNDINGS
INDICATE CAPPING INVERSION TO EXIST ACROSS WESTERN 2/3 OF AREA AND
THUS EXPECT BEST PRECIP CHANCES TODAY TO EXIST ACROSS NE ZONES AND
EASTERN COASTAL PLAINS. LATEST 4KM WRF AND HRRR GUIDANCE BRINGS A
LINE OF SHOWERS AND ISOLATED THUNDERSTORMS THROUGH EASTERN ZONES
THIS MORNING WITH LINE PUSHING OFF COAST AROUND MIDDAY/EARLY
AFTERNOON AND SEE NO STRONG INDICATIONS TO DISCOUNT THIS GUIDANCE
ATTM. STRONG STORM POTENTIAL IS LOOKING LESS LIKELY THAN EARLIER
GUIDANCE RUNS INDICATED AS LOW LEVEL WINDS VEER TOO STRONGLY AND
COOLING OF MID LEVEL TEMPS TO BE SLOWER THAN PREVIOUSLY THOUGHT.
IF ANY STRONG STORMS DEVELOP THEY SHOULD BE VERY ISOLATED AT BEST
AND ACROSS NE ZONES. SURFACE TROUGH TO SLIDE EASTWARD TODAY WITH
WINDS SHIFTING NWRLY BEHIND BOUNDARY AS SIGNIFICANTLY DRIER AIR
WORKS INTO S TX. MAIN SURFACE FRONT TO SLIDE THROUGH S TX LATE
AFTERNOON WITH WINDS BECOMING MORE NNERLY. ANOTHER DAY OF
UNSEASONABLY WARM TEMPS TODAY BEFORE MAX/MIN TEMPS FALL TO
SEASONABLE LEVELS TONIGHT THROUGH WED AS HIGH PRESSURE BUILDS
INTO CWA.
&&
.LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...OVERALL NOT A LOT OF
CHANGES (MAIN ONES TO FALL IN LINE WITH ISC). QUIET WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT WITH MOISTURE RETURNING LATE THURSDAY IN TIME
FOR THE NEXT UPPER LEVEL TROUGH COMING ACROSS LATE FRIDAY.
INTERESTING THAT 00Z ECMWF IS BACK TO CUTTING OFF PART OF THE UPPER
LOW THIS WEEKEND AND RETROGRADING IT AGAIN (AFTER NOT DOING SO ON
ITS 12Z RUN). THUS...AM AGAIN RELYING MORE ON THE GFS SOLUTION WITH
THIS SYSTEM...AND PRETTY MUCH KEEPING THE SAME POPS (DID GO A BIT
HIGHER FARTHER SOUTH FRIDAY/FRIDAY NIGHT). SOME RAINS COULD LINGER
FOR A SHORT TIME SATURDAY MORNING...BUT SHOULD BE CLEARER...WINDY
AND COOLER FOR SATURDAY AFTERNOON WITH CRITICAL FIRE WEATHER
CONDITIONS PROBABLE....AND WINDS NEAR GALE FORCE OVER THE OFFSHORE
WATERS. THIS COULD BE THE COLDEST AIRMASS SO FAR THIS YEAR AS STRONG
HIGH MOVES INTO SOUTHERN PLAINS. HOWEVER...WINDS WILL STAY UP ENOUGH
SO THAT TEMPERATURES SUNDAY MORNING WILL NOT BE TERRIBLY COLD
(MONDAY WILL BE THE COLDEST MORNING...WITH SUNDAY BEING THE COLDEST
DAY). AIRMASS MODIFIES ON MONDAY AHEAD OF ANOTHER FRONT POSSIBLE
EARLY TUESDAY MORNING. NOT MUCH ELSE TO SAY...SUBTLE CHANGES TO
PREVIOUS TEMPERATURE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 87 55 76 54 78 / 50 10 0 0 10
VICTORIA 83 49 74 46 77 / 70 0 0 0 10
LAREDO 86 54 78 55 82 / 10 0 0 0 10
ALICE 88 54 78 51 80 / 30 0 0 0 10
ROCKPORT 83 55 72 56 75 / 50 10 0 0 10
COTULLA 83 49 76 49 79 / 10 0 0 0 10
KINGSVILLE 88 54 76 51 78 / 30 10 0 0 10
NAVY CORPUS 83 58 72 59 74 / 50 10 0 0 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
RH/79...SHORT TERM
GW/79...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1151 PM CST MON NOV 21 2011
.AVIATION...
FOG AND LOW CLOUDS WILL BE THE MAIN AVIATION CONCERN. FOG HAS BEEN
ABLE TO MOVE FURTHER NORTHWESTWARD TO THE DHT TAF SITE...AND
CONTINUES AT AMA. CARRIED VLIFR CONDITIONS AT DHT/AMA THROUGH
15Z/16Z BEFORE IMPROVING TO VFR. LESS CONFIDENCE ABOUT DENSE FOG AT
GUY ATTM BUT WILL CONTINUE TO MONITOR. NORTHERLY WIND SHIFT MOVING
THROUGH THE PANHANDLES ATTM...BUT WINDS SHOULD REMAIN LESS THAN 12
KNOTS. WINDS WILL RETURN THE SOUTH TOWARDS THE LATTER PART OF THE TAF
PERIOD.
&&
.PREV DISCUSSION... /ISSUED 926 PM CST MON NOV 21 2011/
UPDATE...
HAVE ISSUED DENSE FOG ADVISORY FOR ALL OF THE TEXAS PANHANDLE FOR THE
REST OF TONIGHT THROUGH 10 AM TUESDAY.
DENSE FOG HAS DEVELOPED ACROSS WESTERN ZONES. POTENTIAL FOR
ADDITIONAL MORE WIDESPREAD DEVELOPMENT WILL EXIST ACROSS THE TEXAS
PANHANDLE OVERNIGHT AND INTO TUESDAY MORNING. UPDATED TEXT PRODUCTS
HAVE BEEN ISSUED.
COCKRELL
PREV DISCUSSION... /ISSUED 808 PM CST MON NOV 21 2011/
UPDATE...
HAVE MADE SOME UPDATES TO GRAPHICAL FORECASTS FOR THE REST OF TONIGHT
AND TUESDAY MORNING. HAVE REDUCED POPS DOWN TO ISOLATED TO SCATTERED
FOR THE REST OF TONIGHT...BASED ON RADAR TRENDS AND DYNAMICS PRECEIVED
THROUGH SATELLITE AND RUC ANALYSES. RUC AND HRRR ARE SLOW TO BRING
IN DRY AIR FROM WEST TONIGHT. THIS SCENARIO FITS WELL WITH SURFACE
OBS NEAR OR AT SATURATION OVER THE EASTERN PLAINS OF NEW MEXICO AT
THIS TIME. HAVE LOWERED WIND SPEEDS...LOWERED MINIMUM TEMPERATURES
SLIGHTLY IN NORTHERN ZONES...RAISED DEWPOINTS...RECALCULATED DERIVED
ELEMENTS INCLUDING RELATIVE HUMIDITY...AND HAVE INSERTED FOG ACROSS
ALL SECTIONS BEGINNING EARLIER THAN ONSET IN PREVIOUS FORECAST. HAVE
CARRIED FOG INTO TUESDAY MORNING. NO OTHER CHANGES AT THIS TIME.
UPDATED TEXT PRODUCTS WILL BE ISSUED SHORTLY.
COCKRELL
PREV DISCUSSION... /ISSUED 538 PM CST MON NOV 21 2011/
AVIATION...
MAIN AREA OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO MOVE EAST OF
THE TAF SITES...BUT LEFT VCSH REMARKS AT GUY FOR A FEW HOURS. LOW
CLOUDS AND FOG WILL BE THE FORECAST CONCERNS AT GUY/AMA AND HAVE
TRENDED TOWARDS A MORE PESSIMISTIC FORECAST. LOW DEWPOINT DEPRESSIONS
WILL SUPPORT LOW CIGS AND THE DEVELOPMENT OF FOG THROUGH THE
OVERNIGHT AND HAVE INCLUDED LIFR CIGS/VSBYS AT GUY/AMA. WILL AMEND AS
NECESSARY. IFR CONDITIONS AT DHT SHOULD GIVE WAY TO VFR AS DRIER AIR
ATTEMPTS TO MOVE IN FROM THE WEST. WILL CONTINUE TO MONITOR AND SEE
IF FOG IS ABLE TO MAKE IT THAT FAR WEST. EASTERLY TO SOUTHEASTERLY
WINDS WILL BECOME MORE NORTHERLY WITH TIME...BUT SHOULD REMAIN
BETWEEN 10 AND 15 KNOTS THROUGH THE PERIOD.
PREV DISCUSSION... /ISSUED 344 PM CST MON NOV 21 2011/
DISCUSSION...
SCATTERED SHOWERS AND THUNDERSTORMS WERE MOVING ACROSS THE TEXAS AND
OKLAHOMA PANHANDLES THIS AFTERNOON. THIS ACTIVITY WAS GENERATED BY A
LEAD SHORT WAVE IMPULSE LOCATED OVER THE PANHANDLES PER LATEST WATER
VAPOR SATELLITE IMAGERY. AN UPPER-LEVEL TROUGH CURRENTLY OVER THE
FOUR CORNERS REGION WILL CONTINUE TO LIFT NORTHEAST ACROSS THE
SOUTHERN PLAINS TONIGHT. LARGE SCALE ASCENT WILL INCREASE AS THIS
SYSTEM DRAWS CLOSER TO THE REGION...SO EXPECT ADDITIONAL SHOWERS AND
THUNDERSTORMS TO DEVELOP AND MOVE ACROSS THE AREA THIS EVENING.
OPERATIONAL RUNS OF THE GFS/NAM/SREF/RUC SHOW CONVECTION CONTINUING
THIS EVENING BUT QUICKLY SHIFTING TO THE NORTHEAST...WITH THE
AXIS OF HEAVY RAINFALL MOVING INTO OKLAHOMA. FORECAST SOUNDINGS AND
SPC MESOSCALE ANALYSIS GRAPHICS INDICATE AMPLE AMOUNT OF ELEVATED
INSTABILITY PARTICULARLY ACROSS THE SOUTHERN TEXAS PANHANDLE SO
EXPECT THE STORMS TO REMAIN ELEVATED AS WE HEAD INTO EVENING.
ALTHOUGH THESE STORMS HAVE NOT HAD ANY HISTORY LATELY OF PRODUCING
HAIL...THERE STILL REMAINS THE POSSIBILITY THAT SOME OF THE STORMS
CAN BECOME SEVERE DUE TO STEEP MID LEVEL LAPSE RATES AROUND
7-9 C/KM...MUCAPES AROUND 1000 J/KG...AND LARGE BULK SHEER VALUES.
HAIL STILL REMAINS THE MAIN SEVERE WEATHER THREAT BUT EXPECT THIS
THREAT TO DECREASE LATER THIS EVENING. RAIN WILL END LATER TONIGHT
ACROSS MUCH OF THE AREA DUE TO THE PROGRESSIVE NATURE OF THIS
SYSTEM...BUT STILL HELD ONTO SLIGHT CHANCE POPS ACROSS THE EASTERN
TEXAS AND OKLAHOMA PANHANDLES THROUGH 12Z TUESDAY. A PACIFIC COLD
FRONT WILL MOVE INTO THE PANHANDLES AFTER MIDNIGHT TONIGHT. THIS
FRONT WILL PUSH FROM WEST TO EAST ALLOWING MUCH DRIER AIR TO MOVE
ACROSS THE AREA. THIS WILL QUICKLY SHUT OFF PRECIP CHANCES WHILE
ISENTROPIC DOWNGLIDE WILL CAUSE SKIES TO CLEAR FROM WEST TO EAST.
DESPITE THIS INFLUX OF DRIER AIR...HAVE MENTIONED PATCHY FOG IN THE
CENTRAL AND EASTERN ZONES DUE TO RESIDUAL MOISTURE FROM THE RAINS
THIS AFTERNOON/EVENING. NOT EXPECTING FOG TO BECOME WIDESPREAD AND
LAST THAT LONG AS DRY AIR ADVECTION SHOULD CAUSE ANY FOG TO LIFT BY
MORNING. TEMPS THIS AFTERNOON HAVE HOVERED IN THE 40S AND WITH MOST
OF THE AREA REMAINING UNDER MOSTLY CLOUDY SKIES...EXPECT LOWS TO
ONLY FALL INTO THE 30S.
TUESDAY WILL SEE A RETURN TO SUNNY SKIES AS THIS SYSTEM WILL BE WELL
EAST OF THE AREA. TEMPS WILL BE WARMER...DESPITE WINDS REMAINING
OUT OF THE NORTH FOR MUCH OF THE DAY BEHIND THE DEPARTING COLD FRONT.
HEIGHTS RISES ACROSS THE SOUTHERN PLAINS SHOULD HELP TO BUMP TEMPS
UP INTO THE UPPER 50S TO LOWER 60S. A SURFACE LEE-SIDE TROUGH
DEEPENS ACROSS THE WESTERN HIGH PLAINS MID WEEK WHILE AN UPPER
RIDGE BUILDS ACROSS THE ROCKIES. HIGHS WILL CLIMB INTO THE 70S BY
THANKSGIVING DAY IN RESPONSE TO BREEZY DOWNSLOPING SOUTHWEST WINDS.
BY THE END OF THE WEEK...MEDIUM RANGE MODELS CONTINUE TO DEPICT AN
UPPER-LEVEL TROUGH LIFTING NORTHEAST OUT OF THE DESERT SOUTHWEST.
THE GFS AND ECMWF DIFFER ON THE TIMING OF THIS SYSTEM...WITH THE
GFS HAVING A MORE PROGRESSIVE SOLUTION AND AS A RESULT...BRING IN
QPF FRIDAY RATHER THAN SATURDAY AS THE 00 UTC RUN INDICATED.
/HOWEVER THE LATEST 12 UTC ECMWF RUN IS TRENDING TOWARD THE GFS AND
NOW BRINGS IN PRECIP ON FRIDAY/. THE CANADIAN IS DRY THROUGH THE
PERIOD. GIVEN THESE MODEL DISCREPANCIES...HAVE OPTED TO LEAVE THE
FRIDAY TIMEFRAME DRY. A FAIRLY STRONG COLD FRONT WILL PUSH INTO THE
AREA SATURDAY. STRONG COLD AIR ADVECTION BEHIND THE FRONT SUGGESTS
MUCH COOLER CONDITIONS BY THE WEEKEND.
CLK
FIRE WEATHER...
SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS EVENING ACROSS THE
TEXAS AND OKLAHOMA PANHANDLES...AS AN UPPER-LEVEL TROUGH APPROACHES
THE SOUTHERN PLAINS. THIS SYSTEM WILL QUICKLY EXIT EAST OF THE AREA
BY TUESDAY...WITH WARMER AND DRIER CONDITIONS RETURNING TO THE
PANHANDLES. ON TUESDAY LOWEST AFTERNOON RELATIVE HUMIDITIES WILL
FALL TO AROUND 20 PERCENT IN THE WESTERN OKLAHOMA PANHANDLE AND THE
NORTHWEST TEXAS PANHANDLE BUT 20 FOOT WINDS WILL BE AROUND 10 TO 15
MPH...PRECLUDING FIRE WEATHER CONCERNS. ELEVATED FIRE WEATHER
CONCERNS CAN CREEP BACK INTO THE FORECAST WEDNESDAY ACROSS THE
WESTERN ZONES AS MINIMUM RELATIVE HUMIDITIES FALL TO AROUND 15 TO 20
PERCENT WHILE 20 FOOT WINDS INCREASE TO NEAR 15 MPH. ELEVATED OR
CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE THANKSGIVING DAY...
AGAIN ACROSS THE WESTERN TEXAS AND OKLAHOMA PANHANDLES...DUE TO THE
COMBINATION OF MINIMUM RELATIVE HUMIDITIES FALL TO AROUND 10 TO 15
PERCENT WHILE 20 FOOT WINDS INCREASE TO AROUND 15 TO 20 MPH. COOLER
TEMPERATURES AND THUS HIGHER MINIMUM RELATIVE HUMIDITIES ARE
EXPECTED BY THE END OF THE WEEK. RELATIVE HUMIDITIES ABOVE 20
PERCENT ARE EXPECTED THROUGH THE PERIOD...PRECLUDING ELEVATED OR
CRITICAL FIRE WEATHER CONDITIONS.
CLK
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF
SMITH...DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL...
HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM...
POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
OK...NONE.
&&
$$
10/03
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1143 PM CST MON NOV 21 2011
.UPDATE...
LATE EVENING UPDATE TO ELIMINATE EVENING WORDING AND TO CONCENTRATE
ON THE HIGHER POPS TO THE NORTH. EFFECTS OF THE MID-LEVEL DRY SLOT
AND SURFACE TROUGHING OVER WESTERN COUNTIES HAS ENABLED STORM
FOCUS TO RECONCENTRATE FARTHER UPSTREAM WITH THE COLD FRONT
BECOMING MORE WELL-DEFINED ALONG A SW-NE AXIS FROM DRT TO AQO.
50-70 PERECENT CHANCES REMAIN INTACT FOR THE AUS/SAT METRO AREAS
WITH ISOLATED HEAVY DOWNPOURS OVER 1 INCH POSSIBLE. LOWER PORTION
OF THE CONVECTIVE SQUALL LINES SHOW SOME BREAKS...SO WILL POPS
WERE LOWERED ABOUT 10 PERCENT OVER THIS AREA.
&&
.PREV DISCUSSION... /ISSUED 1128 PM CST MON NOV 21 2011/
DISCUSSION...
SEE AVIATION DISCUSSION.
AVIATION...
NO MAJOR CHANGES FROM PREVIOUS TAF PACKAGE WITH MVFR CIGS AT I-35
TERMINALS IMPROVING BACK TO VFR BETWEEN 15-18Z. SHOWERS AND
THUNDERSTORMS WILL EXPAND AND MOVE EAST TOWARD I-35 TERMINALS
THROUGH EARLY TUESDAY MORNING. AT KDRT...MVFR CIGS ARE FORECAST
FOR THE NEXT COUPLE HOURS...WITH VFR CONDITIONS PREVAILING
THEREAFTER. MOISTURE TRAPPED IN THE FRONTAL LAYER ACROSS NORTH TEXAS
AND OKLAHOMA MAY IMPACT I-35 TERMINALS LATE TUESDAY NIGHT WITH IFR
CIGS/VSBYS POSSIBLE. A MODERATE SOUTHERLY LOW LEVEL FLOW WILL
BECOME NORTHERLY BEHIND THE FROPA EARLY TUESDAY MORNING...THEN
DECREASE IN SPEED.
PREV DISCUSSION... /ISSUED 855 PM CST MON NOV 21 2011/
UPDATE...
EVENING UPDATE ENHANCES POPS FOR THE EASTERN HILL COUNTRY COUNTIES
AND INTO THE METRO AREAS. SEVERE POTENTIAL LIKELY TO REMAIN HIGHER
TO THE NORTH...BUT THE SURFACE BOUNDARY IS SHOWING A MORE
PROGRESSIVE TREND. THE FASTER RUC MODEL WAS POPULATED FOR EARLIER
WIND SHIFTS FOR MUCH OF THE HILL COUNTRY AND AUS AREA. THIS TRENDS
THE MIN TEMPS DOWNWARD AS WELL. 00Z NAM SHOWED A DECENT
INITIALIZATION OF CONVECTIVE ACTIVITY WHICH ALSO SUPPORTS SLIGHLTY
HIGHER POPS NEAR THE I-35 CORRIDOR LATE THIS EVENING AND IN THE
EARLY MORNING HOURS. MUCH OF THE INCREASED POPS IS LIKELY
ACCOUNTED FOR BY LIGHTER SHOWERS...SO WHILE POPS WERE RAISED...THE
QPF AMOUNTS SHOULD NOT BE MUCH MORE THAN PREVIOUSLY ASSESSED.
AREAS ALONG AND NORTH OF I-10 COULD SEE RAINFALL AVERAGES OF 1/4
TO 1/2 INCH WITH ISOLATED HIGHER TOTALS UP TO 2 INCHES POSSIBLE
NEAR AND TO THE NE OF THE AUS METRO AREA.
PREV DISCUSSION... /ISSUED 541 PM CST MON NOV 21 2011/
DISCUSSION...
SEE AVIATION DISCUSSION.
AVIATION...
AT I-35 TERMINALS...A MIX OF VFR AND MVFR CIGS THIS EVENING WILL
DETERIORATE TO ALL MVFR BEFORE MIDNIGHT...THEN CONTINUE A DOWNWARD
TREND PRIOR TO THE FRONT PUSHING THROUGH. IFR CIGS ARE NOT
FORECAST AT THIS TIME...BUT ARE POSSIBLE BRIEFLY WITH SHOWERS AND
THUNDERSTORMS EARLY TUESDAY MORNING. IMPROVEMENT BACK TO VFR IS
FORECAST BY MID DAY TUESDAY. AT KDRT...VFR CONDITIONS ARE FORECAST
TO PERSIST THROUGH THE TAF PERIOD. A MODERATE SOUTHERLY LOW LEVEL
FLOW WILL TURN WEST BEHIND THE FRONT AND THEN NORTH LATE TUESDAY.
PREV DISCUSSION... /ISSUED 318 PM CST MON NOV 21 2011/
DISCUSSION...
MODELS IN AGREEMENT MOVING PROGRESSIVE S/W TROUGH INTO CENTRAL
TEXAS OVERNIGHT...BRINGING A COLD FRONT INTO WESTERN PORTIONS AROUND
MIDNIGHT AND EXITING EASTERN PORTIONS AROUND MIDDAY TOMORROW.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL DEVELOP
GENERALLY ALONG AND AHEAD OF THE FRONT. SEVERE DYNAMICS (BETTER
UPPER LEVEL FORCING MECHANISMS, SHEAR) WILL REMAIN MAINLY NORTH OF
OUR CWA TONIGHT AND EARLY TUESDAY...HOWEVER CANNOT RULE OUT TOTALLY
SOME OF THE STORMS APPROACHING SEVERE LIMITS OVERNIGHT OVER OUR
EXTREME NORTHERN CWA. MAXIMUM RAIN AMOUNTS SHOULD BE AROUND A HALF
INCH WITH THIS SYSTEM THROUGH MIDDAY TOMORROW MAINLY OVER OUR
NORTHEAST CORRIDOR. THE SYSTEM WILL EXIT TO THE EAST TOMORROW
EVENING WITH AN INCREASING DRY NORTHWEST FLOW ALOFT AND A DRY
SURFACE RIDGE BUILDING SOUTHWARD INTO THE REGION. WEDNESDAY LOOKS
TO BE MOSTLY SUNNY AND MILD WITH HIGHS IN THE 70S AND RIDGING ALOFT
TRAVERSES THE AREA. AS THE NEXT SYSTEM APPROACHES ON THANKSGIVING...
SOUTHERLY FLOW WILL RETURN WITH INCREASING CLOUDINESS BEGINNING
IN WESTERN PORTIONS AND GRADUALLY DEVELOPING EASTWARD DURING THE
DAY. EARLY MORNING LOWS ON THANKSGIVING WILL GENERALLY BE IN THE
40S WITH AFTERNOON HIGHS RANGING FROM NEAR 70 HILL COUNTRY TO THE
UPPER 70S EXTREME SOUTHWEST. LOW TO MID 70S WILL PREVAIL ALONG THE
I-35 CORRIDOR THANKSGIVING AFTERNOON. THE MODELS ALSO SEEM TO BE IN
GOOD AGREEMENT WITH THE NEXT UPPER AIR SYSTEM. THIS POSITIVELY
TILTED UPPER LEVEL TROUGH WILL ENTER WESTERN TEXAS THURSDAY
NIGHT...PUSHING INTO OUR CWA FRIDAY. THE POLAR JET WILL DIG SOUTH
ON THE BACKSIDE OF THIS SYSTEM AS IT PUSHES ACROSS FRIDAY INTO
FRIDAY NIGHT MAKING IT SLOW DOWN SOMEWHAT FRIDAY...WHICH FORTUNATELY
FOR US...MAY MAKE FOR SLIGHTLY BETTER RAIN AMOUNTS. DUE TO ITS
POSITIVE TILT ORIENTATION AND PROGRESSIVE MOVEMENT...WE DO NOT
ANTICIPATE THIS SYSTEM TO DEVELOP SEVERE WEATHER...AT THE PRESENT
TIME. CLEARING...BREEZY AND COOLER SATURDAY AS DRY NORTHWEST FLOW
ALOFT AND GUSTY NORTH WINDS ACCOMPANY A BUILDING DRY SURFACE RIDGE.
MOSTLY CLEAR AND COOL SUNDAY. COLDER MONDAY MORNING WITH LIGHT WINDS
AND CLEAR SKIES...MAKE EXPECT SOME FREEZING TEMPERATURES ACROSS OUR
CWA NEXT MONDAY MORNING.
FIRE WEATHER...
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED
TOMORROW AFTERNOON OVER WESTERN PORTIONS...GENERALLY WEST OF
WITH U.S. HIGHWAY 83. RELATIVE HUMIDITIES WILL LOWER TO BELOW 20
PERCENT WITH NORTHWEST WINDS OF 10 TO 15 MPH. MORE ELEVATED
CONDITIONS ARE EXPECTED SUNDAY AFTERNOON AS STRONG DRY NORTHWEST
FLOW ALOFT MIXES DOWN TO THE SURFACE.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 65 79 49 73 45 / 70 40 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 67 81 43 73 43 / 70 40 0 0 0
NEW BRAUNFELS MUNI AIRPORT 68 81 43 74 44 / 60 30 0 0 0
BURNET MUNI AIRPORT 57 76 45 72 47 / 60 20 0 0 0
DEL RIO INTL AIRPORT 55 81 46 73 49 / 20 - 0 0 0
GEORGETOWN MUNI AIRPORT 60 77 46 72 43 / 70 30 0 0 0
HONDO MUNI AIRPORT 63 83 42 76 42 / 40 10 0 0 0
SAN MARCOS MUNI AIRPORT 67 80 46 73 43 / 60 30 0 0 0
LA GRANGE - FAYETTE REGIONAL 70 80 48 73 43 / 60 60 - 0 0
SAN ANTONIO INTL AIRPORT 65 82 47 75 47 / 50 30 0 0 0
STINSON MUNI AIRPORT 69 84 48 76 46 / 50 30 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...11
SYNOPTIC/GRIDS...18
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1128 PM CST MON NOV 21 2011
.DISCUSSION...
SEE AVIATION DISCUSSION.
&&
.AVIATION...
NO MAJOR CHANGES FROM PREVIOUS TAF PACKAGE WITH MVFR CIGS AT I-35
TERMINALS IMPROVING BACK TO VFR BETWEEN 15-18Z. SHOWERS AND
THUNDERSTORMS WILL EXPAND AND MOVE EAST TOWARD I-35 TERMINALS
THROUGH EARLY TUESDAY MORNING. AT KDRT...MVFR CIGS ARE FORECAST
FOR THE NEXT COUPLE HOURS...WITH VFR CONDITIONS PREVAILING
THEREAFTER. MOISTURE TRAPPED IN THE FRONTAL LAYER ACROSS NORTH TEXAS
AND OKLAHOMA MAY IMPACT I-35 TERMINALS LATE TUESDAY NIGHT WITH IFR
CIGS/VSBYS POSSIBLE. A MODERATE SOUTHERLY LOW LEVEL FLOW WILL
BECOME NORTHERLY BEHIND THE FROPA EARLY TUESDAY MORNING...THEN
DECREASE IN SPEED.
&&
.PREV DISCUSSION... /ISSUED 855 PM CST MON NOV 21 2011/
UPDATE...
EVENING UPDATE ENHANCES POPS FOR THE EASTERN HILL COUNTRY COUNTIES
AND INTO THE METRO AREAS. SEVERE POTENTIAL LIKELY TO REMAIN HIGHER
TO THE NORTH...BUT THE SURFACE BOUNDARY IS SHOWING A MORE
PROGRESSIVE TREND. THE FASTER RUC MODEL WAS POPULATED FOR EARLIER
WIND SHIFTS FOR MUCH OF THE HILL COUNTRY AND AUS AREA. THIS TRENDS
THE MIN TEMPS DOWNWARD AS WELL. 00Z NAM SHOWED A DECENT
INITIALIZATION OF CONVECTIVE ACTIVITY WHICH ALSO SUPPORTS SLIGHLTY
HIGHER POPS NEAR THE I-35 CORRIDOR LATE THIS EVENING AND IN THE
EARLY MORNING HOURS. MUCH OF THE INCREASED POPS IS LIKELY
ACCOUNTED FOR BY LIGHTER SHOWERS...SO WHILE POPS WERE RAISED...THE
QPF AMOUNTS SHOULD NOT BE MUCH MORE THAN PREVIOUSLY ASSESSED.
AREAS ALONG AND NORTH OF I-10 COULD SEE RAINFALL AVERAGES OF 1/4
TO 1/2 INCH WITH ISOLATED HIGHER TOTALS UP TO 2 INCHES POSSIBLE
NEAR AND TO THE NE OF THE AUS METRO AREA.
PREV DISCUSSION... /ISSUED 541 PM CST MON NOV 21 2011/
DISCUSSION...
SEE AVIATION DISCUSSION.
AVIATION...
AT I-35 TERMINALS...A MIX OF VFR AND MVFR CIGS THIS EVENING WILL
DETERIORATE TO ALL MVFR BEFORE MIDNIGHT...THEN CONTINUE A DOWNWARD
TREND PRIOR TO THE FRONT PUSHING THROUGH. IFR CIGS ARE NOT
FORECAST AT THIS TIME...BUT ARE POSSIBLE BRIEFLY WITH SHOWERS AND
THUNDERSTORMS EARLY TUESDAY MORNING. IMPROVEMENT BACK TO VFR IS
FORECAST BY MID DAY TUESDAY. AT KDRT...VFR CONDITIONS ARE FORECAST
TO PERSIST THROUGH THE TAF PERIOD. A MODERATE SOUTHERLY LOW LEVEL
FLOW WILL TURN WEST BEHIND THE FRONT AND THEN NORTH LATE TUESDAY.
PREV DISCUSSION... /ISSUED 318 PM CST MON NOV 21 2011/
DISCUSSION...
MODELS IN AGREEMENT MOVING PROGRESSIVE S/W TROUGH INTO CENTRAL
TEXAS OVERNIGHT...BRINGING A COLD FRONT INTO WESTERN PORTIONS AROUND
MIDNIGHT AND EXITING EASTERN PORTIONS AROUND MIDDAY TOMORROW.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL DEVELOP
GENERALLY ALONG AND AHEAD OF THE FRONT. SEVERE DYNAMICS (BETTER
UPPER LEVEL FORCING MECHANISMS, SHEAR) WILL REMAIN MAINLY NORTH OF
OUR CWA TONIGHT AND EARLY TUESDAY...HOWEVER CANNOT RULE OUT TOTALLY
SOME OF THE STORMS APPROACHING SEVERE LIMITS OVERNIGHT OVER OUR
EXTREME NORTHERN CWA. MAXIMUM RAIN AMOUNTS SHOULD BE AROUND A HALF
INCH WITH THIS SYSTEM THROUGH MIDDAY TOMORROW MAINLY OVER OUR
NORTHEAST CORRIDOR. THE SYSTEM WILL EXIT TO THE EAST TOMORROW
EVENING WITH AN INCREASING DRY NORTHWEST FLOW ALOFT AND A DRY
SURFACE RIDGE BUILDING SOUTHWARD INTO THE REGION. WEDNESDAY LOOKS
TO BE MOSTLY SUNNY AND MILD WITH HIGHS IN THE 70S AND RIDGING ALOFT
TRAVERSES THE AREA. AS THE NEXT SYSTEM APPROACHES ON THANKSGIVING...
SOUTHERLY FLOW WILL RETURN WITH INCREASING CLOUDINESS BEGINNING
IN WESTERN PORTIONS AND GRADUALLY DEVELOPING EASTWARD DURING THE
DAY. EARLY MORNING LOWS ON THANKSGIVING WILL GENERALLY BE IN THE
40S WITH AFTERNOON HIGHS RANGING FROM NEAR 70 HILL COUNTRY TO THE
UPPER 70S EXTREME SOUTHWEST. LOW TO MID 70S WILL PREVAIL ALONG THE
I-35 CORRIDOR THANKSGIVING AFTERNOON. THE MODELS ALSO SEEM TO BE IN
GOOD AGREEMENT WITH THE NEXT UPPER AIR SYSTEM. THIS POSITIVELY
TILTED UPPER LEVEL TROUGH WILL ENTER WESTERN TEXAS THURSDAY
NIGHT...PUSHING INTO OUR CWA FRIDAY. THE POLAR JET WILL DIG SOUTH
ON THE BACKSIDE OF THIS SYSTEM AS IT PUSHES ACROSS FRIDAY INTO
FRIDAY NIGHT MAKING IT SLOW DOWN SOMEWHAT FRIDAY...WHICH FORTUNATELY
FOR US...MAY MAKE FOR SLIGHTLY BETTER RAIN AMOUNTS. DUE TO ITS
POSITIVE TILT ORIENTATION AND PROGRESSIVE MOVEMENT...WE DO NOT
ANTICIPATE THIS SYSTEM TO DEVELOP SEVERE WEATHER...AT THE PRESENT
TIME. CLEARING...BREEZY AND COOLER SATURDAY AS DRY NORTHWEST FLOW
ALOFT AND GUSTY NORTH WINDS ACCOMPANY A BUILDING DRY SURFACE RIDGE.
MOSTLY CLEAR AND COOL SUNDAY. COLDER MONDAY MORNING WITH LIGHT WINDS
AND CLEAR SKIES...MAKE EXPECT SOME FREEZING TEMPERATURES ACROSS OUR
CWA NEXT MONDAY MORNING.
FIRE WEATHER...
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED
TOMORROW AFTERNOON OVER WESTERN PORTIONS...GENERALLY WEST OF
WITH U.S. HIGHWAY 83. RELATIVE HUMIDITIES WILL LOWER TO BELOW 20
PERCENT WITH NORTHWEST WINDS OF 10 TO 15 MPH. MORE ELEVATED
CONDITIONS ARE EXPECTED SUNDAY AFTERNOON AS STRONG DRY NORTHWEST
FLOW ALOFT MIXES DOWN TO THE SURFACE.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 69 79 49 73 45 / 60 50 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 68 81 43 73 43 / 60 50 0 0 0
NEW BRAUNFELS MUNI AIRPORT 66 81 43 74 44 / 50 40 0 0 0
BURNET MUNI AIRPORT 66 76 45 72 47 / 70 30 0 0 0
DEL RIO INTL AIRPORT 59 81 46 73 49 / 30 20 0 0 0
GEORGETOWN MUNI AIRPORT 68 77 46 72 43 / 70 40 0 0 0
HONDO MUNI AIRPORT 65 83 42 76 42 / 50 30 0 0 0
SAN MARCOS MUNI AIRPORT 67 80 46 73 43 / 50 40 0 0 0
LA GRANGE - FAYETTE REGIONAL 70 80 48 73 43 / 50 60 - 0 0
SAN ANTONIO INTL AIRPORT 67 82 47 75 47 / 50 40 0 0 0
STINSON MUNI AIRPORT 69 84 48 76 46 / 40 40 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...11
SYNOPTIC/GRIDS...18
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
555 PM CST WED NOV 23 2011
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...FORECASTING CLOUD COVER IS THE BIGGEST CHALLENGE OF
TONIGHT AND TOMORROWS FORECAST...AS IT HAS BEEN FOR THE LAST FEW
DAYS. IT IS USUALLY WISE TO KEEP CLOUDS AROUND IN NOVEMBER AND
DECEMBER AND WILL KEEP MORE CLOUDS IN THE FORECAST THAN THE
GUIDANCE WOULD INDICATE. THE RUC HAD THE BEST FORECAST OF THE
CLOUD COVER THIS AFTERNOON WITH CLEARING OCCURRING IN THE DOWNSLOPE
AREA OF NORTHEAST WISCONSIN. IT WOULD KEEP THE CURRENT CLOUDS IN
THE WESTERN PART OF THE FORECAST AREA FOR MOST OF THE NIGHT WITH
CLOUDS REFORMING GENERALLY NORTH OF GREEN BAY IN THE EAST.
DIFFICULT TO SAY FOR SURE. WE HAVE TRIED JUST ABOUT EVERY MODEL
FIELD (1000MB TO 925MB, 925MB, 925 TO 950MB RELATIVE HUMIDITY,
MOISTURE TRANSPORT VECTORS, AND HRR CEILING HEIGHTS) BUT NONE
DEPICT THE CURRENT CLOUDS THAT WELL. LOWS TONIGHT SHOULD BE ABOVE
NORMAL ONCE AGAIN DUE TO MILD BOUNDARY LAYER TEMPERATURES, A
STEADY BREEZE AND CLOUDS. THE COOLEST TEMPERATURES SHOULD BE IN
VALLEYS WITH CLEAR SKIES AND IN AREAS WITH SNOW ON THE GROUND.
THANKSGIVING MAY NOT BE QUITE AS MILD AS IT LOOKED LIKE A FEW
DAYS AGO AS THERE IS A POSSIBILITY THAT THE DAY COULD START OUT
WITH CLOUDS LIKE MOST OF THE LAST FEW DAYS. 925MB TEMPERATURES ARE
VERY MILD THOUGH, AND EVEN WITH CLOUDS IT WILL BE 10 TO 15 DEGREES
ABOVE NORMAL AND THERE SHOULD AT LEAST BE SOME SUNSHINE BY
AFTERNOON IN MOST PLACES.
.LONG TERM...THURSDAY NIGHT TO WEDNESDAY.
SOUTHERLY FLOW AHEAD OF A WEAK COLD FRONT EXPECTED THURSDAY
EVENING. GRADIENT EXPECTED TO SLACKEN DURING THE NIGHT...ESPECIALLY
ACROSS THE NORTH. DEPENDING ON HOW MUCH SNOW PACK IS LEFT...ENOUGH
EVIDENCE TO ADD FOG AFTER MIDNIGHT OVER THE FAR NORTH. MODELS TODAY
ARE SHOWING LOW LEVEL MOISTURE TRAPPED BELOW AN INVERSION LATER
THURSDAY NIGHT INTO FRIDAY. QUESTION IS HOW QUICK THIS LAYER WILL
SATURATE. DO THINK BEST SATURATION WILL OCCUR ACROSS THE NORTH. CONFIDENCE
IS NOT THAT GREAT ACROSS THE SOUTH DUE TO DIFFERING NUMERICAL
GUIDANCE VALUES FOR CLOUD HEIGHT. WITH EXPECTED LOW CLOUDS TO
DEVELOP ACROSS THE NORTH AND WEAK UPWARD VERTICAL MOTIONS...THOUGHTS
TURNED TO THE POTENTIAL FOR DRIZZLE LATE THURSDAY NIGHT INTO FRIDAY.
DO THINK MOISTURE WILL BE TOO SHALLOW THURSDAY NIGHT INTO FRIDAY MORNING...
BUT CLOUD LAYER MAY BE DEEP ENOUGH TO SUPPORT DRIZZLE FRIDAY AFTERNOON.
DID NOT ADD DRIZZLE TO THE FORECAST ACROSS THE NORTH ON FRIDAY AND
WILL PASS ON MY CONCERNS TO MIDNIGHT SHIFT.
FOR FRIDAY NIGHT...MOIST SOUTHERLY FLOW EXPECTED ACROSS THE AREA. THINK
PRECIPITATION WILL START OUT AS DRIZZLE WITH A MORE STEADIER RAIN LATE
FRIDAY NIGHT INTO SATURDAY AS FRONT APPROACHES. PRECIPITATION WILL
CONTINUE INTO SATURDAY. MORE QUESTIONS APPEAR ON SATURDAY AS SEVERAL
MODELS SHOW A DRY SLOT MOVING ACROSS THE REGION SATURDAY AFTERNOON
INTO SATURDAY NIGHT. DESPITE A FEW MODELS DRYING US OUT FOR AWHILE...
WILL CONTINUE A CHANCE OF RAIN SATURDAY AFTERNOON AND RAIN OR SNOW
SATURDAY NIGHT. MANY QUESTIONS LINGER SATURDAY NIGHT ON HOW FAST THE
COLD AIR WILL ARRIVE. LATER SHIFTS WILL PROBABLY NEED TO ALTER TIMING
THE CHANGEOVER TO ALL SNOW ACROSS SOME PORTION OF THE FORECAST AREA.
OTHERWISE...ANOTHER SYSTEM WILL MOVE ACROSS THE AREA MONDAY NIGHT
AND TUESDAY AND WILL BRING ANOTHER SMALL CHANCE FOR RAIN OR SNOW
TO THE AREA.
&&
.AVIATION...
CLOUD FORECAST CONTINUES TO BE VERY UNCERTAIN. WINDS OVER THE AREA
INCREASING...BUT INVERSION STRONG. SAT IMAGERY SHOWING LOW CLOUD
LIFTING NORTH OUT OF FOX VALLEY...THOUGH AREA TO THE WEST LOOKS LIKE
IT IS STARTING TO EXPAND ONCE AGAIN. RUC SEEMS TO HAVE BEST HANDLE
ON THINGS SO HAVE FOLLOWED...CLEARING EAST FOR MOST OF
NIGHT...BRINGING CLOUDS BACK IN AROUND 9Z. WILL KEEP CLOUDS OVER
CENTRAL AREAS. WITH INCREASING WINDS...CIG HEIGHTS EXPECTED TO
STAY IN MVFR RANGE. LOW LEVEL WIND SHEAR POSSIBLE TONIGHT WITH
SOUTHWEST WINDS AROUND 35 KNOTS AT 1000 FT AGL AND SURFACE WINDS
FROM THE SOUTH AT 5 TO 10 KNOTS.
TE
&&
.MARINE...HAZARDOUS CONDITIONS WITH GALE FORCE ARE POSSIBLE OVER
THE UPCOMING WEEKEND. MODEL DIFFERENCES IN STRENGTH AND TIMING OF
THIS SYSTEM THIS WEEKEND ARE MITIGATING FACTORS IN INTRODUCING
GALES IN THE HAZARDOUS WEATHER OUTLOOK. IT APPEARS THAT THE
STRONGEST WINDS WILL BE SATURDAY NIGHT INTO SUNDAY...BUT COULD
START SATURDAY AFTERNOON IF THE QUICKER MODEL SOLUTION IS CORRECT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
532 PM CST WED NOV 23 2011
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
250 PM CST WED NOV 23 2011
MAIN FORECAST CONCERNS THIS PACKAGE...RAIN CHANCES CENTERED ON FRI
NIGHT/SAT...WINDS SAT...TEMPERATURES THRU THE PERIOD.
18Z DATA ANALYSIS HAD LOW PRESSURE MOVING EAST ACROSS CENTRAL
CANADA AND HIGH PRESSURE OVER MO TO EAST TX. VIS IMAGERY/SFC OBS
SHOWED LOW STRATUS REMAINED TRAPPED UNDER AN INVERSION NEAR 925MB
ACROSS MUCH OF WI/IA AND SOUTHEAST MN. LAPS SOUNDINGS AND PILOT
REPORTS INDICATING THE MOISTURE/CLOUDS RATHER SHALLOW UNDER THE
INVERSION. MOST MODELS...EXCEPT FOR GFS...DOING A DECENT JOB
DEPICTING THE LOW LEVEL MOISTURE/CLOUDS THIS MORNING. INCREASING
PRESSURE GRADIENT OVER THE AREA AND WESTERLY FLOW IN THE 925-700MB
LAYER FINALLY STARTING TO ERODE/ADVECT THE LOW LEVEL MOISTURE/CLOUDS
EAST AT MID-DAY...WITH CLEARING WORKING INTO THE WEST END OF THE
FCST AREA.
23.12Z MODELS LOOK TO HAVE INITIALIZED WITHOUT SIGNIFICANT ERRORS
AND OFFER RATHER SIMILAR SOLUTIONS FOR TONIGHT THRU FRI. SOLUTIONS
DIVERGE WITH STRENGTH/TIMING OF THE TROUGH FRI NIGHT INTO SAT NIGHT.
OVERALL TREND LOOKS TO DEVELOP A STRONGER SFC LOW NORTH OF THE AREA
FRI NIGHT/SAT...AND SHUNTS THE DEEPER MOISTURE/PRECIP AHEAD OF IT
A BIT FURTHER EAST. STRONGER LOW RESULTS IN A STRONGER GRADIENT/LOW
LEVEL COLD ADVECTION BEHIND IT ON SAT. DPROG/DT OF 500MB HGTS AT
23.12Z SHOWED MODEL RUNS OF 21.12Z AND 22.12Z VERIFIED QUITE WELL
ACROSS NOAM/EASTERN PAC...BUT ALL WERE A BIT WEAK WITH THE TROUGH
OVER THE OH VALLEY. THRU THU MODEL TRENDS FAVOR THE MORE PROGRESSIVE
OF EARLIER SOLUTIONS WITH A TROUGH EXITING OFF THE EAST COAST. TREND
IS A BIT SLOWER/STRONGER WITH A FEATURE OVER THE CA BAJA AT 00Z FRI.
FOR THU NIGHT/FRI MODELS TRENDING TOWARD A SOLUTION OF MORE
NORTHERN-SOUTHERN STREAM SEPARATION AS THE SHORTWAVE ENERGY COMES
EAST INTO MT TO WEST TX. TREND AT 00Z SAT IS ALSO A BIT SLOWER WITH
THIS ENERGY. BY 00Z SUN MODELS IN TWO CAMPS WITH THE TROUGHING OVER
THE MID/UPPER MS VALLEY...NAM/GFS FASTER...ECMWF/GEM SLOWER. ALL BUT
GEM FASTER THAN THEIR EARLIER RUNS BY SAT NIGHT...AND LOOK TO KEEP
THE NORTHERN/SOUTHERN STREAM PIECES OF ENERGY MORE SEPARATE UNTIL
THE TOUGH AXIS PASSES EAST OF THE AREA. SOMEWHAT BETTER RUN-TO-RUN
CONSISTENCY TONIGHT THRU SAT TO ECMWF. CHECK OF OBS VS. MODEL DATA
AT 18Z SHOWED MODELS ALL REASONABLE WITH THE SFC MASS FIELDS OVER
THE NORTH-CENTRAL CONUS. MOST...BUT FOR GFS...REMAINED GOOD WITH THE
TRAPPED LOW LEVEL MOISTURE/CLOUDS OVER THE REGION. PER WV IMAGERY...
ALL MODELS LOOKED REASONABLE WITH THE SHORTWAVE DETAILS OVER NOAM/
EASTERN PAC. NO CLEAR MODEL FAVORITE THIS CYCLE...BUT WITH ECMWF
OFFERING SOMEWHAT BETTER RUN-TO-RUN CONSISTENCY FAVORED A MODEL/
ENSEMBLE BLEND WEIGHTED TOWARD THE ECMWF. HOWEVER GIVEN THE DETAIL
DIFFERENCES...SHORT-TERM FCST CONFIDENCE AVERAGE THIS CYCLE.
FOR THE SHORT TERM...SFC-850MB GRADIENT CONTINUES TO INCREASE OVER
THE AREA TONIGHT...WITH A DRY WESTERLY COMPONENT OF THE FLOW. LOW
CLOUDS WILL FINALLY CLEAR THE AREA LATE THIS AFTERNOON/EARLY THIS
EVENING. MODEL SOUNDINGS/X-SECTIONS THEN INDICATE A RATHER DEEP...
DRY AIRMASS OVER THE AREA FOR LATER THIS EVENING INTO THU NIGHT AS
MID LEVEL SHORTWAVE RIDGING BUILDS OVER THE AREA. MODERATE PRESSURE
GRADIENT REMAINS OVER THE AREA FOR TONIGHT INTO THU NIGHT...TO LIMIT
ANY FOG POTENTIAL TONIGHT AND FOR SOME LOW LEVEL MIXING ON THU.
925MB TEMPS ON THU PROGGED TO BE IN THE +8 TO +13C RANGE. QUESTION
IS DEPTH OF MIXING. MODEL SOUNDINGS ONLY INDICATE MIXING TO ABOUT
950MB. EVEN SO...WITH PLENTY OF SUNSHINE ON THU HIGHS EXPECTED TO BE
IN THE 50S...SOME 15-20 DEGREES ABOVE NORMAL. SOUTHWEST GRADIENT
WINDS CONTINUE THU NIGHT...FOR LOWS REMAINING MUCH ABOVE NORMAL
UNDER INCREASING HIGH CLOUDS. TEMPS REMAIN MILD FRI WITH THE WARM
START AND SOUTHWEST FLOW AHEAD OF THE APROACHING LOW/TOUGH. GFS NOW
THE LONE MODEL PRODUCING SOME -RA OVER THE SOUTHEAST PARTS OF THE
FCST AREA FRI AFTERNOON. GFS MODEL SOUNDINGS AND X-SECTIONS INDICATE
INITIAL FORCING/LIFT IS ABOVE 500MB WHILE COLUMN BELOW 500MB IS
QUITE DRY THRU 00Z SAT. REMOVED SMALL FRI AFTERNOON -RA CHANCE FROM
THE SOUTH END OF THE FCST AREA. DEEPER MOISTURE/LIFT AHEAD OF THE
TROUGH ARRIVE FRI NIGHT...BUT PLENTY OF DETAIL DIFFERENCES WITH THE
DEPTH/STRENGTH/TIMING OF THIS MOISTURE/FORCING/LIFT. GIVEN THESE
DETAIL DIFFERENCES...ESPECIALLY WITH DEPTH OF MOISTURE/SATURATION OF
THE COLUMN AHEAD OF THE SFC-MID LEVEL TROUGH AXIS...NOT MUCH FOR
CONFIDENCE TO MAKE CHANGES TO PRECIP CHANCES IN THE FRI NIGHT/SAT
FCST GRIDS. ECMWF WOULD IMPLY RAIN CHANCES NEED TO BE RAISED FRI
NIGHT/SAT. MANY OF THE OTHER MODELS WOULD INDICATE THE CHANCES NEED
TO BE LOWERED WITH THE DEEPER MOISTURE/SATURATION REMAINING EAST/
SOUTH OF THE FCST AREA. THUS LEFT MOST RAIN CHANCES FOR FRI NIGHT/
SAT AS IS FOR THIS CYCLE. TIGHTER SFC-850MB GRADIENT ON BACK SIDE OF
THE SFC-850MB LOW IS OVER THE AREA SAT. THIS WITH MDT TO STRONG LOW
LEVEL COLD ADVECTION AND 925MB WINDS INCREASING TO THE 35-40KT
RANGE. DEPENDING ON TIMING/ARRIVAL OF THE STRONGER GRADIENT/COLD
ADVECTION MAY YET NEED A WIND ADVISORY FOR PARTS OF THE AREA SAT.
HIGHS SAT LIKELY TO BE IN THE MORNING WITH STEADY/SLOWLY FALLING
TEMPS IN THE AFTERNOON. SOME INDICATIONS FOR SECONDARY SHORTWAVES TO
ROTATE SOUTH IN THE BACK SIDE OF THE TROUGH LATE SAT/SAT NIGHT...
ALONG WITH MOISTURE WRAPPING AROUND THE SFC-700MB LOW. WITH COLDER
AIR IN PLACE...PRECIP CHANCES IN THE 20-40 PERCENT RANGE FOR
RAIN/SNOW CHANGING TO SNOW SAT NIGHT REASONABLE FOR NOW.
FAVORING A MODEL/ENSEMBLE CONSENSUS...GENERALLY TRENDED LOWS/HIGHS
FOR TONIGHT THRU SAT NIGHT TOWARD A BLEND OF THE NUMERICAL
GUIDANCE.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
250 PM CST WED NOV 23 2011
23.00Z MEDIUM RANGE MODELS IN MODEST AGREEMENT WITH EACH OTHER AND
THEIR PREVIOUS RUNS SUN...BUT STILL PLENTY OF DETAIL DIFFERENCES IN
THE TROUGHING OVER THE EAST HALF OF THE CONUS. MODEST AGREEMENT
CONTINUES MON THE NEXT STRONGER SHORTWAVE TROUGH/ENERGY DROPS
INTO THE NORTHERN PLAINS. TREND IS SLOWER/FURTHER SOUTH WITH AN
UPPER LOW IN THE SOUTHEAST CONUS. MODELS DIVERGE CONSIDERABLY WITH
THE DETAILS BY TUE AND FOR WED...BUT A GENERAL CONSENSUS FOR
LONGWAVE TROUGHING OVER EASTERN NOAM AND LONGWAVE RIDGING ALONG THE
WEST COAST. NONE OF THE MODEL DISPLAYING CLEARLY BETTER RUN-TO-RUN
CONSISTENCY THAN THE OTHERS IN THE SUN-WED PERIOD. OF NOTE THOUGH
23.06Z GFS TRENDED CLOSER TO 23.00Z ECMWF THRU MUCH OF THE DAY 4-7
PERIOD WHILE 23.12Z GFS TRENDED MUCH MORE PROGRESSIVE WITH THE
SOUTHEAST CONUS SYSTEM MON/TUE. NEEDLESS TO SAY...LONG-TERM FCST
CONFIDENCE BELOW AVERAGE THIS CYCLE. WITH NO CLEAR MODEL FAVORITE OR
NO ONE MODEL SHOWING BETTER RUN-TO-RUN CONSISTENCY...PREFER THE
PMDEPD IDEA OF FAVORING A MODEL/ENSEMBLE BLEND FOR NOW. SOME
CONSENSUS FOR SHORTWAVE RIDGING AND HIGH PRESSURE TO BUILD OVER THE
AREA FOR SUN IN THE WAKE OF THE DEPARTING SAT SYSTEM...FOR A
COOL/DRY DAY SUNDAY. NEXT TROUGH/SHORT-WAVE MOVES ACROSS THE
NORTHERN PLAINS MON...BUT DIFFERENCES OF SPEED/STRENGTH APPEAR.
THESE DIFFERENCES...ESPECIALLY AT THE LOWER LEVELS...INCREASE FOR
TUE INTO WED. GFS WITH A SLOWER/ STRONGER SYSTEM ACROSS THE UPPER
MIDWEST/GREAT LAKES LATE MON-WED WITH ECMWF WEAKER/MORE PROGRESSIVE
SYSTEM. AGAIN LIKE PMDEPD IDEA...FCST GRIDS FOR MON-WED INCORPORATED
A STRONG MODEL/ENSEMBLE CONSENSUS/BLEND UNTIL CLEARER DETAILS/
SIGNALS ARE SEEN. OVERALL LONGWAVE TROUGHING IN THE EASTERN CONUS
AND RIDGING OVER WESTERN NOAM RESULTS IN NORTHWEST FLOW ALOFT OVER
THE NORTH-CENTRAL CONUS. TEMPERATURES FOR THE SUN-WED PERIOD LOOKING
TO BE CLOSER TO NORMAL.
&&
.AVIATION...TONIGHT AND THURSDAY
532 PM CST WED NOV 23 2011
STRATUS HAS BEEN STUBBORN TO CLEAR ACROSS THE AREA...WITH MVFR
CEILINGS STILL IN PLACE AT KLSE. BACK EDGE OF THE CLOUDS JUST WEST
OF THE TAF SITE...BUT SATELLITE TRENDS SHOWING THIS BACK EDGE HAS
BECOME NEARLY STATIONARY. MODELS NOT HANDLING THIS LOW LEVEL
MOISTURE WELL AT ALL...WITH BOTH THE RUC AND NAM INDICATING CLOUD
DISSIPATION BY 00Z THURSDAY. SO BIGGEST CONCERN IS WHEN WILL THE
STRATUS CLEAR AT KLSE. AS THE SURFACE HIGH PULLS FURTHER
SOUTHEAST...PRESSURE GRADIENT WILL TIGHTEN OVERNIGHT. BOTH THE RUC
AND NAM BUFKIT SOUNDINGS SHOWING LOW LEVEL WINDS OFF THE SURFACE
INCREASING THIS EVENING AND THUS EXPECT THE STRATUS TO CONTINUE TO
DIMINISH AND PUSH EASTWARD. THUS TRENDED THE KLSE TAF SITE TO BE
STRATUS FREE BY AROUND 02Z. AFTER THAT VFR CONDITIONS WILL
PREVAIL. STILL COULD BE SOME 5SM TO 6SM VISIBILITIES THROUGH THE
OVERNIGHT HOURS...BUT NOTHING LESS THAN THAT. WITH TIGHTER
PRESSURE GRADIENT AND SOME MIXING THURSDAY WILL LIKELY SEE SOME
GUSTS IN THE AFTERNOON AT 19 TO 23 KNOTS AT BOTH TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
250 PM CST WED NOV 23 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
219 PM CST TUE NOV 22 2011
.SHORT TERM...TONIGHT THROUGH FRIDAY
219 PM CST TUE NOV 22 2011
MUCH OF THE FOCUS OVER THE SHORT TERM IS ON WHEN THE CLOUDS WILL GO
AWAY AND THE CONDITIONS FOR THANKSGIVING AND THE TRAVEL DAYS
AROUND IT.
A DEPARTING POSITIVELY TILTED MID LEVEL TROUGH EXTENDING FROM THE
SOUTHWESTERN GREAT LAKES DOWN TO THE LOWER MISSISSIPPI RIVER VALLEY
WILL QUICKLY MOVE TO THE EAST TONIGHT WITH BROAD RIDGING ALOFT
MOVING IN BEHIND THIS FEATURE. A WEAK MID LEVEL SHORT WAVE TROUGH
WILL PROPAGATE AROUND THE NORTHERN PERIPHERY OF THE RIDGE TONIGHT
INTO TOMORROW MORNING BUT SHOULD NOT HAVE MUCH OF AN IMPACT OUTSIDE
OF ADDING SOME HIGH LEVEL CLOUDS INTO THE MIX. DOWN AT THE
SURFACE...A LOW CENTERED OVER THE OHIO RIVER VALLEY WILL TRACK
NORTHEAST THROUGH THE EASTERN GREAT LAKES AS A RIDGE OF HIGH
PRESSURE EXTENDS FROM SOUTHERN ONTARIO THROUGH THE UPPER MISSISSIPPI
RIVER VALLEY REGION.
CLOUD COVER WILL REMAIN PROBLEMATIC THROUGH TOMORROW WITH A THIN
LAYER OF MOISTURE TRAPPED UNDER A SHALLOW INVERSION PER 22.12Z
REGIONAL RAOBS AND RUC SOUNDINGS. THIS THIN LATER OF STRATUS
EXTENDS FROM THE GREAT LAKES BACK INTO EASTERN NORTH DAKOTA AND
NEBRASKA...BUT HAS DEVELOPED AN ELONGATED HOLE THAT RUNS FROM
NORTHEAST WISCONSIN WEST SOUTHWEST THROUGH LA CROSSE TOWARD
CENTRAL IOWA. THE 22.18Z RUC...ALONG WITH PREVIOUS RUNS...HAVE
PICKED UP ON THIS DRY SLOT AND BASICALLY KEEPS IT IN PLACE THROUGH
TONIGHT. THE BACK EDGE TO THE WESTERN SIDE OF THE STRATUS APPEARS
TIED TO THE LOW LEVEL WARM FRONT WHICH IS EXPECTED TO COME THROUGH
THE REGION TOMORROW MORNING. EVEN IF THE CLEAR SLOT REMAINS IN
PLACE TONIGHT...THIS AREA MAY FOG UP QUICKLY GIVEN IDEAL
RADIATIONAL COOLING CONDITIONS WITH LIGHT WINDS AND THE RIDGE
OVERHEAD. SO...CONFIDENCE IS NOT HIGH ON WHEN THE CLOUDS WILL
COMPLETELY CLEAR OUT...BUT THE BETTER CHANCES APPEAR TO BE AROUND
LUNCHTIME TOMORROW WITH THE DRIER AND WARMER WESTERLIES COMING IN.
BEYOND THIS...EVERYTHING STILL LOOKS ON TAP FOR A WARM UP GOING
INTO THANKSGIVING WITH NEARLY IDEAL TRAVEL CONDITIONS OUTSIDE OF
SOME GUSTY WINDS ON THURSDAY. THE SURFACE PRESSURE GRADIENT
TIGHTENS UP ON THANKSGIVING AHEAD OF THE NEXT SYSTEM TRACKING
THROUGH THE ROCKIES WITH 22.12Z NAM AND GFS BUFKIT SOUNDINGS
SHOWING A SHALLOW MIXED LAYER UNDER THE STEEP 900MB INVERSION.
MOMENTUM TRANSFER FROM THESE SOUNDINGS SHOW THAT GUSTS WILL LIKELY
GO UP TO AROUND 20-25KT LATE THURSDAY MORNING INTO THE EARLY
AFTERNOON. TEMPERATURES ARE EXPECTED TO CLIMB INTO THE UPPER 50S
TO NEAR 60 IN SOME SPOTS WITH 22.12Z NAM AND GFS 850MB TEMPERATURE
ANOMALIES BETWEEN 1 TO 2 STANDARD DEVIATIONS. WHILE RECORD HIGH
TEMPERATURES ARE NOT EXPECTED...IT WILL DEFINITELY BE WELL ABOVE
NORMAL.
AS THE FRONT AND SURFACE LOW APPROACH ON FRIDAY...LOW LEVEL
MOISTURE TRANSPORT WILL BE ON THE INCREASE THOUGH DEEP MOISTURE
WILL BE SOMEWHAT LACKING INTO THE AFTERNOON. 22.12Z NAM AND GFS
SOUNDINGS SHOW A DEEP DRY LAYER THAT THE MOISTURE AND FORCING WILL
HAVE TO OVERCOME...WHICH MAY BE TOUGH DURING THE DAY FRIDAY. HAVE
LEFT SOME SLIGHT CHANCE PROBABILITIES FOR NOW FRIDAY
AFTERNOON...BUT HAVE TRIMMED THEM BACK TO MAINLY BEING IN
NORTHEAST IOWA.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
219 PM CST TUE NOV 22 2011
AFTER A QUIET WEEK INTO FRIDAY...THE WEATHER PATTERN BECOMES MORE
ACTIVE THIS WEEKEND INTO EARLY NEXT WEEK. RAIN WILL BECOME MORE
WIDESPREAD ALONG THE AFOREMENTIONED FRONT FRIDAY NIGHT INTO
SATURDAY AS A NORTHERN STREAM TROUGH BRIEFLY PHASES WITH A
SOUTHERN STREAM TROUGH. PLENTY OF QG FORCING WILL BE PROVIDED FROM
THIS FEATURE WHILE LOW LEVEL MOISTURE TRANSPORT CONTINUES TO PUMP
MOISTURE NORTHWARD FROM THE GULF. THE TREND HAS BEEN TO GO A BIT
FURTHER TO THE SOUTHEAST WITH THE BEST CHANCES FOR GETTING THIS
RAIN FRIDAY NIGHT INTO SATURDAY WITH THE MAIN BAND SETTING UP
ACROSS EASTERN IOWA INTO CENTRAL WISCONSIN.
AS THIS SYSTEM MOVES OFF TO THE EAST THE NORTHERN STREAM TROUGH
WILL PROPAGATE OFF TO THE NORTHEAST THROUGH CANADA WHILE THE
SOUTHERN STREAM TROUGH GETS CUT OFF AND LINGERS AROUND THE GREAT
LAKES INTO EARLY NEXT WEEK. CONFIDENCE IS RATHER LOW IN WHERE THIS
LOW WILL TRACK AS THE 22.12Z GFS IS FURTHER EAST WITH THE CORE OF
THE LOW AND PULLS SOME SIGNIFICANTLY COLDER AIR DOWN INTO THE
REGION ON TUESDAY WITH 850MB TEMPERATURES DROPPING TO AROUND -15C.
COMPARE THAT TO THE 22.12Z ECMWF WHICH IS FURTHER WEST WITH THE
LOW AND KEEPS PRECIPITATION ACROSS THE REGION LONGER INTO TUESDAY.
SOME SNOW WILL BE POSSIBLE ON THE BACK SIDE OF THE SYSTEM...BUT
WHEN AND WHERE IT WILL FALL IS STILL UP IN THE AIR AND THIS POINT.
&&
.AVIATION...THIS AFTERNOON THROUGH WEDNESDAY
1125 AM CST TUE NOV 22 2011
PLENTIFUL LOW LEVEL MOISTURE REMAINED TRAPPED ACROSS MN/IA/WI...
UNDER AN INVERSION NEAR 900MB. GIVEN IT/S LATE NOV THIS IS RESULTING
IN WIDESPREAD MVFR/IFR CIGS ACROSS MUCH OF MN/IA/WESTERN WI.
EASTERLY SFC-925MB FLOW AROUND LOW PRESSURE IN SOUTHERN IL WAS
PUSHING SOME DRIER LOW LEVEL AIR WESTWARD INTO THE FCST AREA AT MID
DAY...WITH CIGS/VSBYS RISING TO VFR EAST/SOUTH OF KLSE. SHORT RANGE/
HI-RESOLUTION MODELS DOING A REASONABLE JOB WITH THIS LOW LEVEL
DRYING THIS MORNING...AND TRENDED TAFS FOR A PERIOD OF VFR CIGS/
VSBYS THIS AFTERNOON INTO EARLY THIS EVENING. HOWEVER...WITH ANY
DECREASE OF CLOUDS INTO THIS EVENING AND THE TRAPPED LOW LEVEL/
BOUNDARY LAYER MOISTURE/LIGHT WINDS...AT LEAST MVFR VSBYS IN BR WILL
QUICKLY REDEVELOP WITH DIURNAL COOLING. EXPANSIVE AREA OF MVFR/IFR
CLOUDS OVER WESTERN MN/IA WILL ADVECT EAST TONIGHT/EARLY WED AS THE
MID MS VALLEY LOW MOVES EAST AND THE SFC-MID LEVEL FLOW BECOMES MORE
WESTERLY OVER THE REGION. LOWERED CIGS AGAIN LATER TONIGHT/EARLY WED
MORNING AS THIS MOISTURE/CLOUDS MOVE INTO THE AREA. FINAL TRICKY
POINT WILL BE HOW QUICKLY THIS MOISTURE/CLOUDS MOVE EAST OF THE AREA
WED. MODEL SOUNDINGS/X-SECTIONS INDICATE THIS MOISTURE TO BE VERY
SHALLOW BY WED AND WAS OPTIMISTIC FOR THE LOW CLOUDS TO BREAK UP AT
THE TAF SITES DURING THE MID MORNING HOURS OF WED. GOOD VFR EXPECTED
AT THE TAF SITES FOR LATER WED INTO THU...BUT FOR SOME LATE NIGHT/
EARLY MORNING MVFR VSBYS IN BR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
219 PM CST TUE NOV 22 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
326 AM CST TUE NOV 22 2011
.SHORT TERM...TODAY THROUGH WEDNESDAY...SKY COVER AND TEMPERATURES
ARE THE MAIN FCST CONCERNS.
WV IMAGERY SHOWED A COUPLE POTENT S/W TROFS POISED TO MISS NE WI
TODAY. ONE WAS HEADED TOWARD LK WINNIPEG EARLY THIS MORNING...
WHILE ANOTHER WAS MOVG INTO WSTRN MO. WITH THE ENERGY SPLITTING
AROUND US AND A LACK OF DEEP SATURATION...THE PREVIOUS DRY FCST
LOOKS TO BE ON TRACK. CLOUD TRENDS CONTINUE TO BE PROBLEMATIC.
LOW CLOUDS WERE GRADUALLY INCREASING ACROSS THE FORECAST AREA
AGAIN THIS MORNING. IN ADDITION...SOME HIGHER BASED STRATOCUMULUS
CLOUDS WERE SPREADING IN FROM THE WEST...AIDED BY SOME WAA.
BASED ON THE LATEST SATL/OBSERVATION TRENDS...WILL STAY WITH A
MOSTLY CLOUDY FCST. USED A BLEND OF THE TOP PERFORMING GUIDANCE
SETS FOR MAX TEMPS...WHICH RESULTED IN SLIGHTLY COOLER TEMPS THAN
THE PREVIOUS FCST.
RIDGING AT THE SFC AND ALOFT WILL MOVE INTO WI TONIGHT...WHICH
SHOULD RESULT IN A GRADUAL CLEARING TREND OVERNIGHT. CLEARING
SKIES AND LIGHT WINDS SHOULD LEAD TO PATCHY FOG DEVELOPMENT...
ESP AFTER MIDNIGHT. MIN TEMPS ARE EXPECTED TO DROP INTO THE
20S...WITH SOME LOWER 30S NEAR LK MICH.
AFTER PATCHY MORNING FOG AND LOW CLOUDS DISSIPATE WEDS MORNING...
EXPECT SKIES TO BECOME MOSTLY SUNNY. MIXING THROUGH 950-925 MB
SUPPORTS HIGHS IN THE LOWER TO MIDDLE 40S. THE HIGHER ELEVATIONS
OF NC WI MAY GET JUST AS WARM OR WARMER THAN VALLEY LOCATIONS
AS MIXING TAPS INTO THE WARM AIR ALOFT.
.LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY.
THE GFS ENSEMBLE MEAN INDICATES SPLIT FLOW REMAINING IN PLACE OVER
NORTH AMERICA THROUGH THIS UPCOMING WEEKEND. ONLY ONE TROUGH TO
IMPACT THE REGION OVER THIS PERIOD...WHICH IS PROGGED TO ARRIVE
EARLY THIS WEEKEND. OPERATIONAL MODELS SPIN UP A CLOSED UPPER LOW
WHICH IS AT ODDS WITH THE GFS ENSEMBLE MEAN THAT SHOWS MORE OF A
PROGRESSIVE TROUGH. GIVEN THE FAIR AMOUNT OF SPREAD WITH THE
DETAILS...FIGURE THAT CHANGES TO THE FORECAST SATURDAY THROUGH
TUESDAY WILL BE FAIRLY SMALL.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...HIGH PRESSURE WILL BE
SLIDING TO THE EAST OVER THE OHIO VALLEY WHILE SHORTWAVE TROUGHING
WILL BE MOVING NW OVER TOP A MID-LEVEL RIDGE WELL TO THE NORTHWEST
OF THE REGION. WITH THE GULF OF MEXICO SHUT OF THANKS TO THE
SURFACE HIGH...WILL SEE MOSTLY CLEAR SKIES WEDNESDAY NIGHT INTO
THURSDAY WITH INCREASING SSW WINDS. BY THURSDAY NIGHT...INCREASING
MOISTURE WILL GET DRAWN UP INTO THE NORTHERN MISSISSIPPI VALLEY.
WITH A STRONG INVERSION...LOW STRATUS MAY BECOME AN ISSUE OVER N-C
WISCONSIN. WILL ADD TO THE FORECAST. HIGHS IN THE UPPER 40S TO MID
50S ON THANKSGIVING.
REST OF THE FORECAST...AS HEIGHT FALLS OCCUR OVER THE GREAT
PLAINS...WILL SEE A COLD FRONT SAG INTO NW WISCONSIN ON FRIDAY
AFTERNOON. LOW AND HIGH LEVEL MOISTURE WILL BE ON THE INCREASE...BUT
A SUBSTANTIAL MID-LEVEL DRY WEDGE SHOULD KEEP THE AREA DRY...UNDER
INCREASING CLOUDS. HIGH TEMPS REMAINING VERY MILD. THIS CHANGES
INTO FRIDAY NIGHT THROUGH SATURDAY NIGHT WHEN INCREASING FORCING
ALOFT FINALLY ERODES THE DRY WEDGE AND SURFACE LOW PRESSURE TRACKS
ACROSS THE STATE. SOME POTENTIAL FOR SNOW ON THE BACKSIDE OF THE
SURFACE LOW SATURDAY NIGHT OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN. THE UPPER TROUGH COULD POTENTIALLY LINGER SUNDAY THROUGH
TUESDAY WITH RAIN AND SNOW SHOWERS POSSIBLE...PENDING DETAILS LIKE
SURFACE LOW POSITIONS AND THERMAL FIELDS. WILL HAVE TO KEEP THE
FORECAST GENERIC GIVEN UNCERTAINTIES.
&&
.AVIATION...CEILINGS CONTINUE TO CAUSE GREAT UNCERTAINTY WITH THIS
TAF ISSUANCE. WARM ADVECTION AHEAD OF SYSTEM MOVING THROUGH
NORTHERN PLAINS...LEADING TO INCREASING CLOUDS BETWEEN 5 AND 7K
OVER WESTERN HALF OF STATE. PATCHY LOW CLOUDS SEEN NEAR LAKE AND
FAR NORTHERN WI. TREND IS TO LIFT NORTH. MODEL TIME/HEIGHT
SECTIONS STILL SHOW RETURN OF LOWER CLOUDS EARLY THIS MORNING...
MAYBE LIFTING NORTH OUT OF IL. WILL FOLLOW RUC WHICH SEEMS TO HAVE
BETTER HANDLE ON CURRENT TRENDS. WILL CONTINUE TRENDS TO CLEAR
THINGS OUT TONIGHT AS THE PLAINS SYSTEM DEPARTS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TSK/MPC
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
300 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO OUR REGION THIS THANKSGIVING
THURSDAY AND DOMINATE OUR WEATHER INTO SUNDAY. A COLD FRONT...
APPROACHING FROM THE WEST...WILL MOVE SLOWLY ACROSS OUR REGION
SUNDAY NIGHT INTO MONDAY. LOW PRESSURE MAY DEVELOP ON THE FRONT
ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY NORTHWARD MONDAY
NIGHT INTO TUESDAY NIGHT. MORE LOW PRESSURE IS POSSIBLE DURING
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LOWER CLOUD DECK CONTINUES TO SHRINK AWAY EARLY THIS
MORNING...WITH THE LAST VESTIGES OVER THE SOUTHERN POCONOS AND
SOUTHERN NEW JERSEY AND DELAWARE. THE COLD AIR ADVECTION IS
ENDING...AND THE MOISTURE TRAPPED UNDER THE INVERSION IS MIXING OUT.
THE MOISTURE MAY BE TOUGHER TO SCOUR OUT OF THE HIGHER TERRAIN...AND
THIS MAY HAVE TO BE ACCOUNTED FOR IN THE EARLY MORNING FORECAST.
ELSEWHERE...THE LOWER CLOUDS SHOULD DISSIPATE BEFORE SUNRISE.
CONVECTIVE TEMPERATURES ARE OUT OF REACH TODAY...AND OTHER THAN SOME
HIGH CLOUDINESS THIS MORNING...SKIES SHOULD BE SUNNY. THE BEST PART
OF THE SURFACE PRESSURE GRADIENT IS OVER THE FORECAST AREA
NOW...AND SOME GUSTINESS LINGERS. THE GUSTINESS TO THE WIND SHOULD
DROP BACK EARLY THIS MORNING AS THE LAST OF THE COLD AIR ADVECTION
ENDS.
IT IS POSSIBLE THERE COULD BE SOME GUSTINESS JUST AFTER
SUNRISE...BUT FOR THE MOST PART WINDS SHOULD NOT BE AN ISSUE TODAY.
850 MB TEMPERATURES SUPPORT HIGHS IN THE MID 50S TODAY...WHICH IS
CLOSE TO THE MOS BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
BUILDING MID LEVEL RIDGING SHOULD KEEP ANY HIGH AND MID LEVEL CLOUDS
NORTH OF THE AREA TONIGHT...AND SKIES SHOULD BE CLEAR. AS THE HIGH
REACHES NORTH CAROLINA TONIGHT...THE GRADIENT WILL BACK OFF.
HOWEVER...WINDS MAY NOT BECOME COMPLETELY CALM OUTSIDE OF PROTECTED
AREAS...AS THE GRADIENT WOULD SUPPORT WEST WINDS LESS THAN 10 MPH.
THE ABOVE SCENARIO WOULD SUPPORTS LOWS NEAR THE MOS BLEND IN THE
URBAN AREAS AND PLACES WITH EXPOSURE. FOR PROTECTED AREAS (INCLUDING
THE PINE BARRENS IN NEW JERSEY)...LOWS WERE DROPPED A FEW DEGREES
FROM THE MOS MEAN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A QUIESCENT PERIOD OF WEATHER IS SHAPING UP FOR THE NORTHERN MID
ATLANTIC AREA FRIDAY INTO SUNDAY. THE MODELS HAVE LATCHED ONTO A
COLD FRONT WHICH LOOKS LIKE IT WILL AFFECT OUR AREA MAINLY SUNDAY
NIGHT INTO MONDAY. THEN...MODEL PERFORMANCE HAS SEEMINGLY
DETERIORATED OVER THE PAST 24 TO 48 HOURS, WITH RUN-TO-RUN AND
INTERMODEL INCONSISTENCY AND CHANGEABILITY. WITH NO CLEAR
SIGNALS...IT WAS DECIDED TO JUST USE A BROAD BRUSH OF CHANCE
PROBABILITIES FOR SHOWERS THROUGH THE MONDAY THROUGH WEDNESDAY
PERIOD, WITH A MODERATE TO HIGH AMOUNT OF CLOUDINESS. THE GFS EVEN
PAINTS SOME TYPE OF RAIN/SNOW EVENT WEDNESDAY NIGHT INTO THURSDAY.
LATER MODEL ITERATIONS WILL BE NEEDED TO GAIN MORE CLARITY ON THIS
PERIOD.
SO...HPC TEMPERATURES WERE USED AS A STARTING POINT FOR HIGHS AND
LOWS, WITH SOME MODIFICATIONS FOR LOCAL EFFECTS AND CLIMATOLOGY. A
GENERAL COOLING TREND SHOULD OCCUR THROUGH THE LONG TERM PERIOD...
WITH HIGHS IN THE MID 50S AND LOWER 60S OVER THE WEEKEND, DROPPING
TO THE 40S TO NEAR 50 BY WEDNESDAY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL CONTINUE TO PROVIDE US WITH FINE VFR
FLYING CONDITIONS FRIDAY INTO...OR PERHAPS THROUGH MOST OF...SUNDAY.
A COLD FRONT MOVING IN FROM THE WEST SUNDAY NIGHT WILL MOVE EASTWARD
THROUGH OUR AREA. HOWEVER, A SUCCESSION OF LOWS COULD AFFECT OUR
REGION AND PERHAPS BRING LOWER CONDITIONS AT TIMES INTO THE EARLY OR
EVEN MIDDLE PORTION OF NEXT WEEK. MODEL GUIDANCE HAS BEEN CHANGING
AND INCONSISTENT...SO LITTLE IN THE WAY OF CONFIDENCE CAN BE SHOWN
UNTIL THE MODELS START TO OFFER BETTER AGREEMENT AND RUN-TO-RUN
CONSISTENCY. LOWER CEILINGS AND/OR VISIBILITIES IN SHOWERS/RAIN AND
FOG MAY OCCUR THROUGH MUCH OF THE SUNDAY NIGHT THROUGH WEDNESDAY
TIME PERIOD, THOUGH.
&&
.MARINE...
WINDS HAVE DROPPED BELOW GALE FORCE IN GUSTS JUST ABOUT EVERYWHERE
EARLY THIS MORNING. THE GUSTINESS SHOULD LOSE ITS EDGE WITH THE END
OF THE COLD AIR ADVECTION...SO THE GALE WARNING WILL BE REPLACED BY
A SMALL CRAFT ADVISORY WITH THE EARLY MORNING PACKAGE.
THE GRADIENT REMAINS IN PLACE MOST OF THE DAY...AND AT A GLANCE DOES
NOT APPEAR TO SUPPORT SMALL CRAFT WINDS ANYWHERE AFTER ABOUT 1500
UTC. THEREFORE...THE SMALL CRAFT ADVISORY THAT REPLACES THE GALE
WARNING WILL BE RUN UNTIL ABOUT 1400 UTC ON THE DELAWARE BAY (AND IT
MAY NOT EVEN BE NEEDED THAT LONG).
OVER THE OCEAN WATERS...SEAS ARE STILL RUNNING 5 TO 9 FEET...WITH
THE HIGHEST SEAS ACROSS THE SOUTHERN WATERS. WHILE WINDS SHOULD DROP
BELOW SMALL CRAFT LEVELS IN GUSTS BY 1500 UTC...THE SEAS ACROSS THE
SOUTHERN WATERS MAY TAKE LONGER TO SORT THEMSELVES OUT. BASED ON THE
ABOVE...THE SMALL CRAFT ADVISORY WILL BE RUN THROUGH ABOUT 1500 UTC
ACROSS THE NORTHERN OCEAN WATERS...AND ABOUT 1800 UTC ACROSS THE
SOUTHERN OCEAN WATERS.
AFTER THIS...THE GRADIENT LOOKS TO SUPPORT WINDS AROUND 15 KNOTS ON
THE OCEAN FOR THE REST OF TODAY INTO TONIGHT. WINDS ACROSS THE
DELAWARE BAY WILL BE SLIGHTLY LOWER...BUT PROBABLY DO NOT DROP BELOW
10 KNOTS...AS THE GRADIENT LOOKS TO SUPPORT WINDS OF THESE SPEEDS.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR MARINE
AREA FRIDAY THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST,
A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY. THE PRESSURE
GRADIENT WILL TIGHTEN BETWEEN THESE TWO SYSTEMS...AND THIS WILL MEAN
A GOOD CHANCE OF SHOWERS AS WELL AS INCREASING SOUTH TO SOUTHEAST
WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY. A SERIES OF LOW
PRESSURE SYSTEMS COULD AFFECT OUR AREA THROUGH THE EARLY AND MIDDLE
PORTIONS OF NEXT WEEK...BUT MODEL GUIDANCE HAS BECOME TOO CHANGEABLE
AND INCONSISTENT TO OFFER ANY KIND OF SPECIFICS. ADVISORY CONDITIONS
ARE LIKELY AT SOME POINT...AND EVEN GALE CONDITIONS MAY OCCUR FOR A
TIME...IN THE SUNDAY NIGHT TO MID WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
TIDE DEPARTURES HAVE RISEN A BIT EARLY THIS MORNING...EVEN AS WINDS
HAVE SHIFTED TO THE NORTH. IT COULD BE THAT AN EKMAN SPIRAL HAS
DEVELOPED ON THE OCEAN WATERS...WHICH PRODUCES A NET MASS TRANSPORT
OF WATER TO THE SHORE. THIS COULD ACCOUNT FOR THE TIDE DEPARTURES
RUNNING BETWEEN THREE-QUARTERS AND ONE AND ONE-QUARTER FEET ABOVE
PREDICTED EARLY THIS MORNING.
THE HIGH ASTRONOMICAL TIDES WILL BRING THE HIGH TIDE CYCLE WITH
ONE-HALF FOOT OF THE MINOR TIDAL FLOODING BENCHMARK WITHOUT ANY
RESIDUAL TIDE EFFECTS. GIVEN WHAT IS GOING ON NOW...AS WELL AS THE
PREPONDERANCE OF TIDE MODEL GUIDANCE...A COASTAL FLOOD ADVISORY WILL
BE ISSUED FOR THE OCEAN...RARITAN BAY AND THE BACK BAYS FOR THE
MORNING HIGH TIDE.
TIDE DEPARTURES ARE CURRENTLY NEGATIVE ACROSS THE DELAWARE BAY AND
TIDAL DELAWARE RIVER. THE TIDE MODEL GUIDANCE BRINGS BOTH OF THESE
LOCATIONS CLOSE TO THE MINOR TIDAL FLOODING BENCHMARK LATER THIS
MORNING AND EARLY THIS AFTERNOON. FOR NOW...WILL WATCH TRENDS AND
ISSUE A COASTAL FLOOD STATEMENT IF IT APPEARS AS THOUGH IT MAY BE
CLOSE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...COASTAL FLOOD ADVISORY UNTIL 9 AM EST THIS MORNING FOR
NJZ012>014-020-022>027.
DE...COASTAL FLOOD ADVISORY UNTIL 9 AM EST THIS MORNING FOR DEZ003-
004.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ450-
451.
SMALL CRAFT ADVISORY UNTIL 8 AM EST THIS MORNING FOR ANZ430-
431.
&&
$$
SYNOPSIS...
NEAR TERM...HAYES
SHORT TERM...HAYES
LONG TERM...
AVIATION...HAYES/
MARINE...HAYES/
TIDES/COASTAL FLOODING...HAYES
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
149 AM EST THU NOV 24 2011
.SYNOPSIS...
A HIGH PRESSURE SYSTEM OVER THE TENNESSEE VALLEY LATE THIS EVENING
WILL BUILD INTO THE REGION AND DOMINATE OUR WEATHER THROUGH THE
WEEKEND. A COLD FRONT, APPROACHING FROM THE WEST, WILL MOVE SLOWLY
ACROSS OUR REGION SUNDAY NIGHT AND MONDAY. LOW PRESSURE MAY
DEVELOP ON THE FRONT ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY
NORTH MONDAY NIGHT INTO TUESDAY NIGHT. ANOTHER FRONTAL SYSTEM,
WITH A REINFORCING SHOT OF COLD AIR, WILL APPROACH FROM THE
NORTHWEST WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE STUBBORN STRATOCUMULUS TRAPPED UNDER THE INVERSION IN THE
COLD AIR ADVECTION IS FINALLY BREAKING UP. A BATCH REMAINS ACROSS
THE SOUTHERN POCONOS...AND THIS ONE COULD TAKE SOME TIME TO BREAK
MORE WITH THE UPSLOPE FLOW. THE BATCH OVER SOUTHERN NEW JERSEY AND
SOUTHERN DELAWARE SHOULD CONTINUE TO BREAK UP AS DRIER AIR IS
ENTRAINED INTO THE LOWER LEVELS.
THE BEST SURFACE PRESSURE GRADIENT IS ACROSS THE FORECAST AREA
EARLY THIS MORNING...AND WINDS REMAIN AT OR ABOVE 10 MPH IS MOST
PLACES. THERE IS STILL SOME GUSTINESS OUT THERE EARLY THIS
MORNING...AS LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT.
AMDAR SOUNDINGS SHOWED 32 TO 35 KNOTS OF WINDS AT THE TOP OF IN
THE INVERSION...SO THERE COULD BE SOME GUSTINESS FOR THE NEXT HOUR
OR TOW. AFTER THAT...THE GUSTINESS SHOULD ABATE...BUT MOST PLACES
PROBABLY KEEP A STEADY NORTH TO NORTHWEST WIND OVERNIGHT.
LOW TEMPERATURES APPEAR TO BE IN LINE...AND LITTLE CHANGE WAS
NEEDED FOR THE OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
HIGH PRESSURE CONTINUES TO MOVE INTO OUR REGION TOMORROW HELPING US
TO MAINTAIN THE NORTHWESTERLY WINDS AND CLEAR SKIES. THE PRESSURE
GRADIENT WILL BEGIN TO SLACKEN EVEN MORE TOMORROW AND DEEP MIXING
APPEARS OUT THE QUESTION SO GUSTS SHOULD NOT BE AN ISSUE...AROUND 15
KNOTS OR LESS. IT IS CERTAINLY GOING TO BE ONE GORGEOUS
THANKSGIVING DAY.
HAPPY THANKSGIVING!!!!
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A LARGE HIGH PRESSURE SYSTEM, CENTERED JUST TO OUR SOUTH, WILL
MOVE SLOWLY EAST TO A POSITION JUST OFF THE NORTH CAROLINA COAST
ON SATURDAY. THIS SYSTEM WILL SUPPLY US WITH FAIR AND RELATIVELY
MILD WEATHER THROUGH THE WEEKEND. WILL SEE PLENTY OF SUNSHINE
FRIDAY AND SATURDAY. CLOUDS WILL BEGIN TO INCREASE SUNDAY AS THE
HIGH MOVES OFF TO THE EAST AND A COLD FRONT APPROACHES FROM THE
WEST. THERE COULD BE A FEW LIGHT SHOWERS SPREADING INTO OUR
NORTHWEST SECTIONS LATE IN THE DAY. DAYTIME HIGHS FRIDAY THROUGH
SUNDAY WILL BE IN THE MID 50S TO MID 60S. OVERNIGHT LOWS WILL BE
MAINLY IN THE 30S THURSDAY NIGHT AND IN THE MID 30S TO MID 40S
FRIDAY NIGHT AND SATURDAY NIGHT. RAIN IS LIKELY SUNDAY NIGHT AND
MONDAY AS THE COLD FRONT CROSSES THE REGION. LOW PRESSURE WILL
THEN DEVELOP ON THE FRONT ALONG THE MID ATLANTIC COAST AND MOVE
NORTH. THIS COULD MORE RAIN TO OUR AREA MONDAY NIGHT INTO TUESDAY
NIGHT. WITH CLOUDS AND RAIN, HIGH TEMPERATURES MONDAY AND TUESDAY
WILL BE SLIGHTLY LOWER THAN OVER THE WEEKEND, WITH READINGS IN
THE UPPER 40S AND 50S. BY WEDNESDAY, ANOTHER FRONT WILL BE
APPROACHING FROM THE NORTHWEST, AS AN UPPER TROUGH MOVES EAST
FROM THE GREAT LAKES. THIS FRONT WILL USHER IN A REINFORCING
SHOT OF COLD AIR BUT WILL BE MOISTURE STARVED. LOOKS LIKE THE
MOST WE COULD GET WOULD BE SCATTERED SHOWERS. HIGH TEMPERATURES
WEDNESDAY WILL BE IN THE 40S TO LOWER 50S.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
THE HIGH PRESSURE SYSTEM TO OUR SOUTH WILL CONTINUE TO PROVIDE US
WITH GOOD VFR FLYING CONDITIONS WELL INTO SUNDAY. A COLD FRONT
MOVING IN FROM THE WEST AND A LOW DEVELOPING ON THIS FRONT, ONCE
IT MOVES JUST OFF TO OUR EAST, WILL BRING OUR NEXT ROUND OF
INCLEMENT WEATHER SUNDAY NIGHT INTO THE MIDDLE OF NEXT WEEK.
LOWER CIGS/VSBYS IN RAIN AND FOG CAN BE EXPECTED FOR MUCH OF
THAT TIME PERIOD.
&&
.MARINE...
WITH THE COLD FRONT NOW TO OUR EAST AND HIGH PRESSURE TRYING TO NOSE
IN FROM THE WEST THE SURFACE PRESSURE GRADIENT WILL REALLY TIGHTEN
UP TONIGHT. NORTHERLY TO NORTHWESTERLY WINDS WILL BEGIN TO REALLY
HOWL WITH MULTIPLE HOURS OF GALE FORCE GUSTS EXPECTED TONIGHT. SEAS
WILL ALSO REMAIN QUITE ELEVATED TONIGHT IN THE WAKE OF THE STRONGER
NNW FLOW RUNNING AROUND 6 FEET.
THE GALE WARNING IS STILL IN AFFECT FOR ALL OUR COASTAL ZONES
THROUGH 09Z...THAT REMAINS UNCHANGED. AFTER THAT TIME PERIOD THE
GUSTS DROP INTO SMALL CRAFT RANGE FOR A FEW MORE HOURS FOLLOWED BY
SMALL CRAFT FOR HAZARDOUS SEAS BEING A POSSIBILITY.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR WATERS
THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST, A COLD FRONT
WILL APPROACH FROM THE WEST. THE PRESSURE GRADIENT WILL TIGHTEN
BETWEEN THESE TWO SYSTEMS. THIS WILL MEAN INCLEMENT WEATHER WITH
INCREASING S TO SE WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY.
LOW PRESSURE IS THEN FORECAST TO DEVELOP ON THE FRONT ONCE IT MOVES
OFF THE EAST COAST. DEPENDING ON THE TIMING AND LOCATION OF THE LOW,
ADVISORY OR GALE CONDITIONS COULD OCCUR IN THE SUNDAY NIGHT TO MID
WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
TIDE DEPARTURES HAVE RISEN A BIT EARLY THIS MORNING...EVEN AS WINDS
HAVE SHIFTED TO THE NORTH. IT COULD BE THAT AN EKMAN SPIRAL HAS
DEVELOPED ON THE OCEAN WATERS...WHICH PRODUCES A NET MASS TRANSPORT
OF WATER TO THE SHORE. THIS COULD ACCOUNT FOR THE TIDE DEPARTURES
RUNNING BETWEEN THREE-QUARTERS AND ONE AND ONE-QUARTER FEET ABOVE
PREDICTED EARLY THIS MORNING.
THE HIGH ASTRONOMICAL TIDES WILL BRING THE HIGH TIDE CYCLE WITH
ONE-HALF FOOT OF THE MINOR TIDAL FLOODING BENCHMARK WITHOUT ANY
RESIDUAL TIDE EFFECTS. GIVEN WHAT IS GOING ON NOW...AS WELL AS THE
PREPONDERANCE OF TIDE MODEL GUIDANCE...A COASTAL FLOOD ADVISORY WILL
BE ISSUED FOR THE OCEAN...RARITAN BAY AND THE BACK BAYS FOR THE
MORNING HIGH TIDE.
TIDE DEPARTURES ARE CURRENTLY NEGATIVE ACROSS THE DELAWARE BAY AND
TIDAL DELAWARE RIVER. THE TIDE MODEL GUIDANCE BRINGS BOTH OF THESE
LOCATIONS CLOSE TO THE MINOR TIDAL FLOODING BENCHMARK LATER THIS
MORNING AND EARLY THIS AFTERNOON. FOR NOW...WILL WATCH TRENDS AND
ISSUE A COASTAL FLOOD STATEMENT IF IT APPEARS AS THOUGH IT MAY BE
CLOSE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...COASTAL FLOOD ADVISORY FROM 5 AM TO 9 AM EST THIS MORNING FOR
NJZ012>014-020-022>027.
DE...COASTAL FLOOD ADVISORY FROM 5 AM TO 9 AM EST THIS MORNING FOR
DEZ003-004.
MD...NONE.
MARINE...GALE WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR ANZ430-431-
450>455.
&&
$$
SYNOPSIS...RPW
NEAR TERM...GIGI/HEAVENER
SHORT TERM...HEAVENER
LONG TERM...RPW
AVIATION...HAYES/RPW
MARINE...GIGI/HEAVENER/RPW
TIDES/COASTAL FLOODING...HAYES
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1213 AM EST THU NOV 24 2011
.SYNOPSIS...
A HIGH PRESSURE SYSTEM OVER THE TENNESSEE VALLEY LATE THIS EVENING
WILL BUILD INTO THE REGION AND DOMINATE OUR WEATHER THROUGH THE
WEEKEND. A COLD FRONT, APPROACHING FROM THE WEST, WILL MOVE SLOWLY
ACROSS OUR REGION SUNDAY NIGHT AND MONDAY. LOW PRESSURE MAY
DEVELOP ON THE FRONT ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY
NORTH MONDAY NIGHT INTO TUESDAY NIGHT. ANOTHER FRONTAL SYSTEM,
WITH A REINFORCING SHOT OF COLD AIR, WILL APPROACH FROM THE
NORTHWEST WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE STUBBORN STRATOCUMULUS TRAPPED UNDER THE INVERSION IN THE
COLD AIR ADVECTION IS FINALLY BREAKING UP. A BATCH REMAINS ACROSS
THE SOUTHERN POCONOS...AND THIS ONE COULD TAKE SOME TIME TO BREAK
MORE WITH THE UPSLOPE FLOW. THE BATCH OVER SOUTHERN NEW JERSEY AND
SOUTHERN DELAWARE SHOULD CONTINUE TO BREAK UP AS DRIER AIR IS
ENTRAINED INTO THE LOWER LEVELS.
THE BEST SURFACE PRESSURE GRADIENT IS ACROSS THE FORECAST AREA
EARLY THIS MORNING...AND WINDS REMAIN AT OR ABOVE 10 MPH IS MOST
PLACES. THERE IS STILL SOME GUSTINESS OUT THERE EARLY THIS
MORNING...AS LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT.
AMDAR SOUNDINGS SHOWED 32 TO 35 KNOTS OF WINDS AT THE TOP OF IN
THE INVERSION...SO THERE COULD BE SOME GUSTINESS FOR THE NEXT HOUR
OR TOW. AFTER THAT...THE GUSTINESS SHOULD ABATE...BUT MOST PLACES
PROBABLY KEEP A STEADY NORTH TO NORTHWEST WIND OVERNIGHT.
LOW TEMPERATURES APPEAR TO BE IN LINE...AND LITTLE CHANGE WAS
NEEDED FOR THE OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
HIGH PRESSURE CONTINUES TO MOVE INTO OUR REGION TOMORROW HELPING US
TO MAINTAIN THE NORTHWESTERLY WINDS AND CLEAR SKIES. THE PRESSURE
GRADIENT WILL BEGIN TO SLACKEN EVEN MORE TOMORROW AND DEEP MIXING
APPEARS OUT THE QUESTION SO GUSTS SHOULD NOT BE AN ISSUE...AROUND 15
KNOTS OR LESS. IT IS CERTAINLY GOING TO BE ONE GORGEOUS
THANKSGIVING DAY.
HAPPY THANKSGIVING!!!!
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A LARGE HIGH PRESSURE SYSTEM, CENTERED JUST TO OUR SOUTH, WILL
MOVE SLOWLY EAST TO A POSITION JUST OFF THE NORTH CAROLINA COAST
ON SATURDAY. THIS SYSTEM WILL SUPPLY US WITH FAIR AND RELATIVELY
MILD WEATHER THROUGH THE WEEKEND. WILL SEE PLENTY OF SUNSHINE
FRIDAY AND SATURDAY. CLOUDS WILL BEGIN TO INCREASE SUNDAY AS THE
HIGH MOVES OFF TO THE EAST AND A COLD FRONT APPROACHES FROM THE
WEST. THERE COULD BE A FEW LIGHT SHOWERS SPREADING INTO OUR
NORTHWEST SECTIONS LATE IN THE DAY. DAYTIME HIGHS FRIDAY THROUGH
SUNDAY WILL BE IN THE MID 50S TO MID 60S. OVERNIGHT LOWS WILL BE
MAINLY IN THE 30S THURSDAY NIGHT AND IN THE MID 30S TO MID 40S
FRIDAY NIGHT AND SATURDAY NIGHT. RAIN IS LIKELY SUNDAY NIGHT AND
MONDAY AS THE COLD FRONT CROSSES THE REGION. LOW PRESSURE WILL
THEN DEVELOP ON THE FRONT ALONG THE MID ATLANTIC COAST AND MOVE
NORTH. THIS COULD MORE RAIN TO OUR AREA MONDAY NIGHT INTO TUESDAY
NIGHT. WITH CLOUDS AND RAIN, HIGH TEMPERATURES MONDAY AND TUESDAY
WILL BE SLIGHTLY LOWER THAN OVER THE WEEKEND, WITH READINGS IN
THE UPPER 40S AND 50S. BY WEDNESDAY, ANOTHER FRONT WILL BE
APPROACHING FROM THE NORTHWEST, AS AN UPPER TROUGH MOVES EAST
FROM THE GREAT LAKES. THIS FRONT WILL USHER IN A REINFORCING
SHOT OF COLD AIR BUT WILL BE MOISTURE STARVED. LOOKS LIKE THE
MOST WE COULD GET WOULD BE SCATTERED SHOWERS. HIGH TEMPERATURES
WEDNESDAY WILL BE IN THE 40S TO LOWER 50S.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
THE HIGH PRESSURE SYSTEM TO OUR SOUTH WILL CONTINUE TO PROVIDE US
WITH GOOD VFR FLYING CONDITIONS WELL INTO SUNDAY. A COLD FRONT
MOVING IN FROM THE WEST AND A LOW DEVELOPING ON THIS FRONT, ONCE
IT MOVES JUST OFF TO OUR EAST, WILL BRING OUR NEXT ROUND OF
INCLEMENT WEATHER SUNDAY NIGHT INTO THE MIDDLE OF NEXT WEEK.
LOWER CIGS/VSBYS IN RAIN AND FOG CAN BE EXPECTED FOR MUCH OF
THAT TIME PERIOD.
&&
.MARINE...
WITH THE COLD FRONT NOW TO OUR EAST AND HIGH PRESSURE TRYING TO NOSE
IN FROM THE WEST THE SURFACE PRESSURE GRADIENT WILL REALLY TIGHTEN
UP TONIGHT. NORTHERLY TO NORTHWESTERLY WINDS WILL BEGIN TO REALLY
HOWL WITH MULTIPLE HOURS OF GALE FORCE GUSTS EXPECTED TONIGHT. SEAS
WILL ALSO REMAIN QUITE ELEVATED TONIGHT IN THE WAKE OF THE STRONGER
NNW FLOW RUNNING AROUND 6 FEET.
THE GALE WARNING IS STILL IN AFFECT FOR ALL OUR COASTAL ZONES
THROUGH 09Z...THAT REMAINS UNCHANGED. AFTER THAT TIME PERIOD THE
GUSTS DROP INTO SMALL CRAFT RANGE FOR A FEW MORE HOURS FOLLOWED BY
SMALL CRAFT FOR HAZARDOUS SEAS BEING A POSSIBILITY.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR WATERS
THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST, A COLD FRONT
WILL APPROACH FROM THE WEST. THE PRESSURE GRADIENT WILL TIGHTEN
BETWEEN THESE TWO SYSTEMS. THIS WILL MEAN INCLEMENT WEATHER WITH
INCREASING S TO SE WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY.
LOW PRESSURE IS THEN FORECAST TO DEVELOP ON THE FRONT ONCE IT MOVES
OFF THE EAST COAST. DEPENDING ON THE TIMING AND LOCATION OF THE LOW,
ADVISORY OR GALE CONDITIONS COULD OCCUR IN THE SUNDAY NIGHT TO MID
WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
THE CONSENSUS OF THE LATEST GUIDANCE PRODUCTS (STEVENS, MDL AND
THE BOFS FAMILY) GIVES TIDAL DEPARTURES THAT WOULD JUST TOUCH
MINOR TIDAL FLOODING LEVELS ALONG THE OCEANFRONT. MOST OF THE
FORECAST DEPARTURES ARE LESS THAN HALF A FOOT AS THE BULK OF THE
TIDE ISSUES HAVE TO DO WITH THE ASTRONOMICAL SPRING TIDE
ASSOCIATED WITH THE NEW MOON. BECAUSE OVERALL WAVE ACTION IS NOT
EXPECTED TO BE UNUSUALLY HIGH AND NO RAIN IS EXPECTED, WE HAVE
DECIDED TO ISSUE A COASTAL FLOOD STATEMENT VS AN ADVISORY. THE
FORECAST NORTH WINDS ARE CAUSING SOME OF THE HIGHER GUIDANCE TIDAL
DEPARTURES AT SANDY HOOK AND LEWES.
FARTHER UP IN DELAWARE BAY AND THE TIDAL DELAWARE RIVER, THE WIND
DIRECTION SHOULD ASSIST. OVERALL TIDAL DEPARTURES HAVE TO BE
GREATER THAN AT THE SHORE, GENERALLY AROUND THREE-QUARTERS OF A
FOOT. THE ONE CAVEAT THAT WE WILL HAVE TO WATCH IS THE BELOW FLOOD
STAGE RIVER CREST NOW WORKING ITS WAY DOWN THE DELAWARE RIVER.
ALONG CHESAPEAKE BAY, NO TIDAL PROBLEMS ARE BEING REPORTED WITH
THE CURRENT HIGH TIDE CYCLE AND DEPARTURES ARE ALREADY DECREASING.
THE OVERALL NORTHWEST TO NORTH WINDS SHOULD HELP CONTINUE DRAIN IT
AND LOWER DEPARTURES INTO THURSDAY MORNING.
ASTRONOMICAL HIGH TIDES WITH THE CURRENT NEW MOON SPRING TIDE
CYCLE WILL PEAK ON FRIDAY MORNING. CURRENT EXPECTATIONS ARE FOR
THE WIND DIRECTION TO BE LESS FAVORABLE AND BY THEN THE DELAWARE
RIVER FRESH WATER CREST WILL ALSO BE THROUGH.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...GALE WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR ANZ430-431-
450>455.
&&
$$
SYNOPSIS...RPW
NEAR TERM...GIGI/HAYES/HEAVENER
SHORT TERM...HEAVENER
LONG TERM...RPW
AVIATION...HAYES/RPW
MARINE...GIGI/HEAVENER/RPW
TIDES/COASTAL FLOODING...GIGI
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
202 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE WEST TONIGHT AND
PERSIST THROUGH THE WEEKEND. ANOTHER COLD FRONT WILL AFFECT THE
REGION EARLY NEXT WEEK...FOLLOWED BY ANOTHER HIGH PRESSURE SYSTEM.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
NO NOTEWORTHY CHANGES WERE MADE THIS THE EARLY MORNING UPDATE.
FRESHENED UP HOURLY GRIDS TO ACCOUNT FOR FALLING TEMPS AND
DEWPOINTS. OTHERWISE...GOING FORECAST IS IN GOOD SHAPE.
LAKE WINDS...WINDS AT BOTH PINEVILLE AND PINOPOLIS INDICATE WINDS
ARE SOLIDLY WITHIN LAKE WIND ADVISORY THRESHOLDS. ALTHOUGH WINDS
SHOULD PEAK WITHIN THE NEXT FEW HOURS...IT WILL TAKE SOMETIME FOR
SPEEDS TO DIMINISH. A LAKE WIND ADVISORY WILL CONTINUE FOR LAKE
MOULTRIE UNTIL 6 AM.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
AN UPPER LEVEL TROUGH WILL CONTINUE TO PUSH OFFSHORE ON THURSDAY
AS RIDGING BUILDS INTO THE REGION FROM THE WEST. THE UPPER LEVEL
RIDGE WILL THEN PREVAIL OVER THE SOUTHEASTERN STATES THROUGH
SATURDAY. AT THE SURFACE...EXPANSIVE HIGH PRESSURE WILL PERSIST
ACROSS THE MID-ATLANTIC REGION AND SOUTHEAST STATES THROUGH
FRIDAY...THEN BEGIN TO SHIFT OFFSHORE ON SATURDAY.
STRONG SUBSIDENCE AND A LACK OF ANY SIGNIFICANT MOISTURE WILL RESULT
IN RAIN FREE CONDITIONS AND MAINLY CLEAR SKIES INTO FRIDAY.
THEN...AS THE LOW LEVEL FLOW BECOMES MORE ONSHORE SOUTH OF THE
SURFACE HIGH...AN INCREASE IN CLOUD COVER IS EXPECTED INTO THE START
OF THE WEEKEND...ESPECIALLY ACROSS SOUTHEAST GEORGIA. TEMPERATURES
WILL BE SLIGHTLY BELOW NORMAL ON THURSDAY...MODERATE TO NEAR NORMAL
ON FRIDAY...THEN BECOME SLIGHTLY ABOVE NORMAL BY SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT SHOWING A BLOCKING
RIDGE DEVELOPING OVER THE WESTERN ATLANTIC BY THE END OF THE
WEEKEND...RESULTING IN THE DEVELOPMENT OF A HIGHLY AMPLIFIED UPPER
LEVEL TROUGH NEAR THE MISSISSIPPI VALLEY. MODELS THEN SHOW A CLOSED
UPPER LEVEL LOW DEVELOPING SOMEWHERE OVER THE SOUTHEAST STATES EARLY
IN THE WEEK...BUT THERE IS SIGNIFICANT SPREAD IN THE MODELS WITH
RESPECT TO THE LOCATION AND PROGRESSION OF THE UPPER LEVEL
LOW...WITH THE 23/00Z GFS MORE PROGRESSIVE THAN THE 23/00Z ECMWF AND
CANADIAN. THIS LEADS TO A RATHER LOW CONFIDENCE FORECAST...BUT WILL
FAVOR THE GFS SOLUTION WHICH IS IN LINE WITH HPC THINKING. AS A
RESULT...A COLD FRONT IS EXPECTED TO APPROACH FROM THE WEST LATE IN
THE WEEKEND...PUSHING THROUGH THE AREA SUNDAY NIGHT INTO MONDAY AS
THE TROUGH AXIS TAKES ON A NEGATIVE TILT. A GOOD MOISTURE FEED AHEAD
OF THE FRONT SHOULD RESULT IN A SOLID CHANCE OF SHOWERS ACROSS MUCH
OF THE AREA...WITH PERHAPS A FEW STRONG THUNDERSTORMS ACCOMPANYING
THE FRONT ITSELF. DRIER CONDITIONS ARE EXPECTED TUESDAY AND
WEDNESDAY AS THE FRONT SHIFTS OFFSHORE AND THE UPPER LOW LIFTS
NORTHWARD. ABOVE NORMAL TEMPERATURES LATE IN THE WEEKEND WILL FALL
BELOW NORMAL IN WAKE OF THE COLD FRONT.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS AT BOTH SITES THROUGH 06Z FRIDAY. GUSTS AT KCHS HAS
DIMINISHED AND THIS WILL CONTINUE THROUGH THE PREDAWN HOURS. HAVE
MAINTAINED LLWS MENTION AT BOTH SITES AS 35 KT WINDS AREN/T TOO FAR
OFF THE DECK. WINDS WILL TURN TO MORE NE AFTER SUNRISE AND THERE
MAY EVEN BE SOME LOW END GUSTS THROUGH LATE MORNING AS THE HIGH
CONTINUES TO BUILD IN FROM THE WEST. OTHERWISE...CLOUD FREE
CONDITIONS WILL PREVAIL WITH NE FLOW INTO TONIGHT.
EXTENDED AVIATION OUTLOOK...SUB-VFR CONDITIONS POSSIBLE SUN/MON IN
SCATTERED SHOWERS AND T-STORMS.
&&
.MARINE...
SMALL CRAFT ADVISORIES CONTINUE FOR ALL MARINE LEGS. BUOY
OBSERVATIONS AND RADAR DATA INDICATE THE INITIAL WIND SURGE
CONTINUES TO WORK SOUTH. A SPECIAL MARINE WARNING HAS BEEN ISSUED
ALONG AND AHEAD OF THE LEADING LEDGE TO COVER GUSTS TO 35-40 KT
FOR LESS THAN 2 HOURS. INCOMING RUC DATA SUGGEST MARGINAL GALES
MAY OCCUR BEHIND THE WIND SURGE FOR SEVERAL MORE HOURS WITH
BOUNDARY LAYER WINDS FORECAST TO BE RIGHT AT 35 KNOTS. MODIS WATER
TEMPERATURE DATA INDICATE SEA SURFACE TEMPERATURES ARE IN THE
UPPER 60S TO LOWER 70S BEYOND 40 NM...SO GALES COULD CERTAINLY
OCCUR IN THE WARMER WATERS WERE MORE VIGOROUS MIXING WILL OCCUR.
HOWEVER...PER COORDINATION WITH WFO JAX...HAVE OPTED TO HOLD WINDS
AT 25-30 KT FOR NOW SINCE THE EVENT LOOKS MARGINAL AND HANDLE
WITH A STRONG SMALL CRAFT ADVISORY. A GALE WARNING MAY STILL BE
NEEDED...BUT CONFIDENCE IS NOT GREATER THAN 80 PERCENT ATTM.
THURSDAY THROUGH MONDAY...IMPROVING CONDITIONS ARE EXPECTED ON
THURSDAY AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE
NORTHWEST. WINDS AND SEAS SHOULD FALL BELOW SMALL CRAFT ADVISORY
CRITERIA FOR ALL NEAR SHORE WATERS BY THE END OF THE DAY
THURSDAY...BUT A FAVORABLE FETCH WILL KEEP SEAS ELEVATED ABOVE
ADVISORY CRITERIA ACROSS THE OUTER GEORGIA WATERS THROUGH FRIDAY
AFTERNOON.
THE AREA OF HIGH PRESSURE WILL PREVAIL OVER THE REGION INTO THE
WEEKEND...WITH A COLD FRONT THEN EXPECTED TO APPROACH FROM THE WEST
LATE IN THE WEEKEND AND PUSH OFFSHORE EARLY NEXT WEEK. ADDITIONAL
SMALL CRAFT ADVISORIES ARE POSSIBLE OVER PORTIONS OF THE WATERS IN
ASSOCIATION WITH THIS FRONT.
&&
.TIDES/COASTAL FLOODING...
GIVEN THE UPCOMING PERIGEAN SPRING TIDES THERE IS A PRETTY GOOD
CHANCE OF EXCEEDING COASTAL FLOOD ADVISORY CRITERIA DURING THE
MORNING HIGH TIDES THURSDAY THROUGH AT LEAST SATURDAY. WITH THE
ASTRONOMICAL PREDICTED VALUES RIGHT AT 7.0 FT IN CHARLESTON HARBOR
THURSDAY THROUGH SATURDAY MORNINGS...ONLY A NEUTRAL OR HIGHER
ANOMALY WILL BE NECESSARY FOR MINOR COASTAL FLOODING. THIS APPEARS
QUITE LIKELY GIVEN THE VEERING WIND PROFILE LATE TONIGHT THROUGH
THURSDAY. LATER SHIFTS MAY NEED TO ISSUE A COASTAL FLOOD ADVISORY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR AMZ330-
352.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR AMZ354.
SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR AMZ374.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
320 AM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 08Z...
* IFR CIGS THROUGH MID/LATE MORNING.
* GUSTY SOUTHWEST WINDS THROUGH THE PERIOD...PRIMARILY THIS
AFTERNOON.
* LLWS POTENTIAL TONIGHT. CMS
//DISCUSSION...UPDATED 06Z...
STRATUS DECK CONTINUES TO SPREAD ACROSS THE REGION AND WILL BE
OVER ALL TERMINALS WITHIN THE NEXT HOUR. CIGS QUICKLY DROPPED
FROM LOW END MVFR TO HIGH TO MIDDLE RANGE IFR. VERY STRONG
SUBSIDENCE INVERSION NOTED ON THE 00Z RAOB OUT OF DVN...AND WOULD
EXPECT THE STRATUS DECK TO REMAIN THROUGH THE MORNING HOURS. WARM
AIR ADVECTION WILL BEGIN TO RAMP UP AND BOUNDARY LAYER FLOW WILL
ALSO INCREASE INTO THE MORNING...AND IT IS THEN THAT THE CLOUDS
SHOULD LIFT AND THEN BEGIN TO ERODE. INTO THE AFTERNOON
HOURS...EFFICIENT MIXING WILL ALLOW GUSTS IN THE AFTERNOON TO
REACH INTO THE LOWER 20KT RANGE AND WILL LAST UNTIL SUN DOWN. AS
GUSTS FALL OFF...THE POTENTIAL EXISTS FOR LLWS INTO THE EVENING
HOURS. FORECAST SOUNDINGS SHOWING ROUGHLY 40KT AT 02KFT...JUST
FLIRTING WITH CRITERIA. FOR NOW...WILL WITHHOLD ANYTHING IN THE
ORD TAFOR.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 08Z...
* HIGH CONFIDENCE IFR CIGS WILL PERSIST THROUGH MID/LATE MORNING.
* MEDIUM CONFIDENCE CIGS WILL LIFT/SCATTER OUT THIS AFTERNOON...
LOW CONFIDENCE ON TIMING.
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* LOW CONFIDENCE IN MEETING LLWS CRITERIA TONIGHT. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...VFR
* SATURDAY...RA. MVFR LIKELY WITH IFR POSSIBLE
* SUNDAY THROUGH TUESDAY...MVFR. SHRA WITH POSSIBLE RASN OVERNIGHT
SHEA
&&
.MARINE...
300 AM CST
WINDS HAVE BEEN A LITTLE SLOW TO INCREASE THIS MORNING DESPITE A
FAIRLY TIGHT PRESSURE GRADIENT AND STRONG FLOW ALOFT IN PLACE. WITH
TWO SEPARATE AREAS OF LOW PRESSURE TO THE NORTH AND NORTHWEST OF THE
LAKE AND A RIDGE OF HIGH PRESSURE JUST TO THE SOUTHEAST...STRONG
SOUTHERLY FLOW CONTINUES TO USHER IN WARMER AIR TO THE NORTH.
BELIEVE THIS IS WHAT MAY BE CAUSING THIS SLOW INCREASE IN WIND SPEED
AS A SLIGHTLY MORE STABLE LAKE MAY BE IN PLACE THAN WHAT CURRENT
GUIDANCE IS INDICATING. NONETHELESS...WINDS WILL CONTINUE TO
INCREASE TODAY AS THIS TIGHT PRESSURE GRADIENT REMAINS AND FLOW
ALOFT INCREASES. PERSISTENT SOUTHWEST WINDS TO 30 KT CAN BE EXPECTED
INTO FRIDAY FOR BOTH THE NORTH AND SOUTH HALF OF LAKE MICHIGAN. HAVE
LEFT OUT ANY MENTION OF GALES FOR THE LAKE THIS FORECAST
ISSUANCE...BUT DO THINK THERE MAY BE BRIEF PERIODS OF HIGHER WINDS
AROUND GALES LATE THIS AFTERNOON AND EARLY EVENING MAINLY FOR THE
NORTH HALF OF THE LAKE. ALTHOUGH DO FEEL THAT THIS WILL BE SPORADIC
AND BRIEF...THUS LEAVING ANY MENTION OF GALES OUT OF THE CURRENT
FORECAST. SOUTHWEST WINDS WILL SLOWLY BEGIN TO DIMINISH FRIDAY NIGHT
INTO SATURDAY...BUT WILL BECOME MORE WESTERLY ON SATURDAY AS AN AREA
OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY PUSH ACROSS THE
LAKE. THEN A PERIOD OF WEST TO NORTHWEST WINDS CAN BE EXPECTED INTO
THE START OF NEXT WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
411 AM EST THU NOV 24 2011
.SHORT TERM...
AS FEARED...POTENTIAL WRINKLES IN TERMS OF STRATUS AND FOG CAME TO
FRUITION OVERNIGHT AND ARE CAUSE FOR SIGNIFICANT CHANGES TO SHORT
TERM FORECAST GRIDS. 11-3.9 MICRON SATELLITE IMAGE SHOWS LARGE AREA
OF STRATUS ACROSS THE MS AND OH RIVER VALLEY REGIONS AND QUICKLY
EXPANDING NORTHEAST ACROSS OUR AREA AS OF 08Z. 1000MB SW FLOW OF 5
TO 10 KNOTS AIDING IN MOVING STRATUS NORTHEAST. THE ENTIRE SHORT
TERM FORECAST HINGES ON WHAT THIS STRATUS DECK DOES OVER NEXT 24
HOURS AND HENCE THE SHORT TERM PROBLEM OF THE DAY.
NAM12 AND RUC HAVE SOME CLUE THAT STRATUS EXISTS BUT HRRR SEEMS TO
HAVE BEST HANDLE BY FAR. MOS GUIDANCE HAS NO CLUE WITH CLOUD COVER
CATEGORIES MAINLY CLEAR THROUGH THE PERIOD AND EVEN LAMP GUIDANCE AS
OF 08Z HAS NO INDICATION. THUS MOS TEMPS NOT CLOSE TODAY FOR
OPTIMISTIC 50S UNLESS CLOUD COVER ERODES QUICKLY WHICH IS DOUBTFUL
AT THIS TIME. NAM12 BUFKIT SOUNDINGS SHOW SATURATED SURFACE TO 1KFT
LAYER WITH STRONG INVERSION AND VERY DRY AIR ABOVE. WHILE YESTERDAYS
MODEL RUNS MIXED THE LOWER LEVELS...LATEST RUNS ARE MUCH STRONGER
WITH INVERSION AND SLIGHTLY DEEPER WITH MOIST LAYER LEADING TO
LITTLE MIXING UNTIL LATE AFTERNOON. LATEST HRRR LOW CLOUD PRODUCT
HAD STRATUS AREA NAILED AT INITIATION AND KEEPS IT LOCKED THROUGH
ITS VALID PERIOD WHICH IS MID AFTERNOON. HRRR 2M TEMPS ALSO REMAIN
IN UPPER 30S AND LOWER 40S THROUGH MID AFTERNOON. ALSO SOME CONCERN
FOR DRIZZLE FOR A FEW HOURS AFTER SUNRISE AS TURBULENT MIXING OF
SHALLOW CLOUD TOPS OFTEN LEADS TO PERIOD OF LIGHT
PRECIPITATION...ESPECIALLY WHEN SUB CLOUD LAYER IS MOIST WITH BR OR
FOG. HAVE ADDED A CHANCE FOR DRIZZLE TO ACCOUNT FOR THIS POSSIBILITY
THROUGH MID MORNING.
A LOOK BACK AT SATELLITE TRENDS ON WEDNESDAY REVEALED VERY LITTLE
MIXING OF STRATUS AND THUS CONCERNED FOR SIMILAR TREND TODAY INTO
TONIGHT. SUBTLE DIFFERENCE TODAY WILL BE INCREASING WINDS IN THE
1000-925MB LAYER... ESPECIALLY ABOVE 950MB WITH 40 TO 50 KNOTS
DEVELOPING LATE TONIGHT. HOWEVER...THIS WILL BE JUST ABOVE INVERSION
AND MAY NOT BE ENOUGH TO MIX OUT LOWER STRATUS DECK GIVEN STRONG
INVERSION IN PLACE. 1000MB WINDS LOOK TO INCREASE BUT ONLY IN THE 5 TO
15 KNOT RANGE WITH LIGHTER WINDS UPSTREAM WHERE STRATUS COULD
REDEVELOP AND AGAIN ADVECT BACK IN.
AFTER MUCH COLLABORATION HAVE OPTED FOR CLOUDY CONDITIONS THROUGH
EARLY AFTERNOON WITH A SUBTLE OPTIMISTIC TRANSITION TO PARTLY CLOUDY
MID TO LATE AFTERNOON. KEPT SKY COVER IN PARTLY CLOUDY RANGE TONIGHT
WITH UNCERTAINTY CONTINUING AS TO DEGREE OF REDEVELOPMENT IF WE
ACTUALLY DO BREAK OUT THIS AFTERNOON. STRONGER FLOW ON FRIDAY AHEAD
OF NEXT SYSTEM SUGGEST ANY REMAINING STRATUS WOULD MIX OUT MID TO
LATE MORNING.
TEMPS OBVIOUSLY WILL BE IMPACTED SIGNIFICANTLY WITH THIS STRATUS.
HAVE LOWERED HIGHS TODAY SEVERAL DEGREES BUT LIKELY NOT NEARLY
ENOUGH IF CLOUDS PERSIST ALL DAY. HAVE TO RESPECT PARTIAL CLEARING
IN AFTERNOON SO DID NOT GO AS LOW AS COLDEST MODEL BLENDS. 06Z NAM12
KEEPING TEMPS IN 30S ALL AREAS TODAY. MINS TONIGHT NOW HEAVILY
DEPENDENT ON ACTUAL MAX TEMPS TODAY BUT EXPECT LITTLE DROP OFF WITH
DECENT GRADIENT AND CLOUD POTENTIAL. KEPT TEMPS IN LOW TO MID 40S
TONIGHT. HIGHS ON FRIDAY STILL LOOK TO BE NEAR 60 WITH BETTER MIXING
BUT CONCERNS CONTINUE FOR LINGERING STRATUS IN THE MORNING.
&&
.LONG TERM.../SATURDAY THROUGH WEDNESDAY/
FEW SIG CHANGES TO LONG TERM WITH MODEL TURMOIL STILL ABUNDANT
THROUGH THE PERIOD. ARRIVAL OF TROUGH FROM THE WEST AND ASSOCIATED
PRECIP STILL NOT MUCH CLEARER WITH NAM/GFS SPREADING RAIN ACROSS THE
AREA MID MORNING WEST INTO AFTERNOON EAST VS ECMWF MORE QUICK
AFTERNOON ARRIVAL WEST TO EAST. THESE FASTER SOLUTIONS ALSO PUSHES
PRECIP OUT AFTER 6Z SUN IN WESTERN AREAS. THINK COMPROMISE STILL
NEEDED IN MODELS...MEANING GENERALLY SAME FORECAST FOR SAT/SAT NGT.
TEMPS STILL GOING TO BE TRICKY BUT WITH INCREASING MID/HIGH CLOUDS
THINK THEY WILL BE KEPT IN CHECK ESPECIALLY WEST. HAVE INCREASED SKY
COVER TO REFLECT FASTER CLOUD ARRIVAL.
ECMWF ONLY MODEL THAT STARTS PROGRESSIVE SUNDAY WITH GFS/GEFS/GEM
ALL SHOWING CLOSED UPPER LOW ACROSS THE GREAT LAKES /IN VARYING
LOCATIONS/. WITH TIME...ECMWF AND GEM CONTINUE A DEPICTION OF RAPID
DEEPENING OF UPPER LOW AND MAJOR TRANSLATION SOUTHWARD IN ENERGY.
GFS/GEFS HOLD WITH NORTHERN INFLUENCE BEING STRONGER. NEXT TROUGH
WILL MOVE INTO THE AREA MONDAY NIGHT INTO TUESDAY AND INTERACT WITH
CLOSED LOW WHEREVER IT MAY BE. THINK THERE WILL BE AT LEAST A
DECENT SHOT FOR PRECIP UNDER THE UPPER LOW WITH COOL NW FLOW ACROSS
THE LAKE AND SYNOPTIC MSTR STILL ACROSS THE AREA. IN
ADDITION...PIECE OF ENERGY SHOULD ROTATE ACROSS THE AREA ON SUNDAY.
WILL MAINTAIN MID RANGE CHC POPS FOR NOW WITH POSSIBLE INCREASE TO
LIKELY WITH TIME. BASED ON THERMAL PROFILES...HAVE OPTED TO THROW IN
MIX MENTION FOR THE DAY AS 1000-850 MB VALUES DROP TO NEAR OR BELOW
1300 M.
HAVE ONLY MADE MINOR TWEAKS TO POPS FROM CR INIT TO PLACE HIGHER
EMPHASIS ON PAST VS PRESENT WITH SLIGHTLY HIGHER POPS. WHILE AN
OUTLIER...IF ECMWF SOLUTION OF UPPER LOW EVENTUALLY WORKING NORTH
TOWARDS THE AREA MON NGT INTO TUES NGT BODES TRUE...COULD BE RATHER
WET. ECMWF HAS BEEN VERY VARIABLE OF LATE...BUT NO WORSE THAN SOME
OF THE OTHERS LEADING TO AT LEAST CONSIDERATION OF THE SCENARIO.
REGARDLESS OF SOLUTIONS...NORMAL TO BELOW NORMAL TEMPS WILL BE IN
STORE SUNDAY AND BEYOND.
&&
.AVIATION...
STRATUS DECK CONTINUES TO ADVECT RAPIDLY NORTHEAST OUT OF CENTRAL
ILLINOIS AND INDIANA. THIS SHOULD OVERSPREAD TERMINAL SITES AROUND
07Z AT KSBN AND 08Z AND KFWA BASED ON LATEST EXTRAPOLATION FROM
SATELLITE. CIGS GENERALLY IN THE 4-8HFT RANGE WITH VIS BETWEEN 1 AND
2SM. HAVE TRENDED TAFS TO THIS RANGE. MODELS NOT HANDLING STRATUS
AREA WELL BUT NAM BUFKIT HINTED AT IT LAST NIGHT AND DOES SHOW
SATURATED LOWER LEVELS BELOW VERY STRONG INVERSION AT BOTH TAF
SITES. CONCERN IS NAM12 SOUNDINGS NOW SHOW SATURATED LOWER LEVELS
PERSISTING THROUGH MUCH OF THE DAY UNTIL VERY LATE AFTERNOON WHEN
MIXING FINALLY DRIES OUT LOWER LEVELS. GIVEN TRENDS ON WEDNESDAY OF
SLOW ERODING STRATUS HAVE TRENDED TAFS TO A MORE PESSIMISTIC NATURE
WITH SLOWER EROSION OF LOW CLOUD DECK.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR LMZ043-046.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
335 AM CST THU NOV 24 2011
.SYNOPSIS...
SFC HIGH CENTERED OVER THE TN/OH VLYS EARLY THIS AM. MOIST LOW LEVEL
RETURN FLOW (SFC DEWPTS IN 40S) ON WESTERN AND SOUTHERN PERIPHERY OF
HIGH WITH 11-3.9 MICRON SATL IMAGERY SHOWING LARGE AREA OF LOW
CLOUDS WITHIN THIS MOIST AXIS. SOME FOG ALSO FOUND OVER REGION BUT
MAINLY LIGHT (2-6SM) DUE TO BLANKET OF LOW CLOUDS AND ALSO S/SW WINDS
OF 5-10 KTS KEEPING BL MIXED JUST ENOUGH.
&&
.SHORT TERM...TODAY AND TONIGHT...
ANOTHER DIFFICULT FCST REVOLVING AROUND SKY COVER TRENDS WITH HUGE IMPACT
ON TEMPS. COMPOUNDING DIFFICULTY IS THAT IT/S HARD TO FIND MODEL DOING
WELL IN CAPTURING COVERAGE/EXTENT OF LOW CLOUDS. OBSERVED SOUNDINGS
SHOW MOISTURE TO BE VERY SHALLOW ON THE ORDER OF 20 MB OR SO IN DEPTH
BUT BELOW VERY STRONG LOW LEVEL INVERSION. IT IS EXPECTED THOUGH THAT
MIXING TO INCREASE TDY AIDED BY STRENGTHENING SFC PRESSURE GRADIENT
WITH DEVELOPING GUSTY S/SW WINDS. THIS SHOULD BE SUFFICIENT TO TAP LARGE
AMOUNTS OF DRY AIR NEAR BASE OF INVERSION TO BEGIN EROSION PROCESS/
CLEARING TREND LATER THIS AM THROUGH AFTN. HIGHEST CONFIDENCE OF SEEING
CLEARING TDY IS ACROSS W/SW SECTIONS BEING IN CLOSER PROXIMITY TO
BACK EDGE OF STRATUS. LOWEST CONFIDENCE OF ANY CLEARING OF IS ACROSS NW IL
COUNTIES WHERE MOIST LOW LEVEL PARCEL TRAJECTORIES ARE AIMED. THE
HRRR LOW CLOUD PRODUCT... WHICH DID REALLY WELL YSTDY WITH STRATUS...
SUPPORTS THIS IDEA OF BEST CLEARING POTENTIAL W/SW OF MISSISSIPPI RVR TDY
AND HAVE TAILORED FCST CLOSELY TOWARD THIS SCENARIO. OBVIOUSLY AS CLOUDS
GO TDY... SO GO TEMPS. LOOKING BACK YSTDY TO OUR WEST NOTICED THAT AREAS
KEPT STRATUS THROUGH 18Z BEFORE DECREASING SAW HIGHS GENERALLY IN RANGE
OF 47-55 DEGS WITH U50S NEAR KC METRO. WENT WITH THIS GENERAL RANGE FOR MOST
OF CWA BEING COOLEST NW IL... AND WARMEST SE IA INTO NORTHEAST MO WHERE HAVE
SOME U50S/NR 60 DEGS. OF COURSE IF STRATUS HOLDS AND WHERE THAT DOES
OCCUR WILL SEE TEMPS ONLY GO UP 3-5 DEGS FOR HIGHS GENERALLY MID 40S.
IF CLEARING BUSTS OPEN EARLIER THEN WITH GUSTY S/SW WINDS WOULD SEE MORE
AREAS NR 60 OR IN THE 60S FOR HIGHS AND POSSIBLY NEARING RECORDS. SHOULD THIS
OCCUR MOST LIKELY WRN/SRN CWA.
TNGT... WENT WITH GENERAL IDEA THAT ANY CLEARING TO FILL BACK IN WITH
STRATUS WITH MOIST LOW LEVEL SFC PARCEL TRAJECTORIES STILL AIMED AT REGION.
THIS ALSO SUPPORTED BY BACKUP RUC MODEL AVIATION FLIGHT CATEGORIES PRODUCT
WHICH SHOWS IFR CONDITIONS BLOSSOMING THROUGHOUT REGION. GIVEN THIS AND
SLY WINDS AROUND 10 KTS WITH SOME GUSTS STAYED AT OR ABOVE WARMEST GUIDANCE
FOR LOWS... WITH WIDESPREAD L/M 40S. SOME FOG POSSIBLE BUT MAINLY LIGHT
(2-6SM) DUE TO CLOUDS AND SOUTH WINDS AROUND 10 KTS WITH SOME GUSTS.
..05..
.LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY...
FORECAST FOCUS ON RAIN FRIDAY NIGHT AND SATURDAY OTHERWISE MAINLY A
CHILLY BUT DRY PERIOD.
FRIDAY...EXPECTING A WARM DAY IN THE BRISK SOUTHERLY FLOW AS TROUGH
DIVES INTO THE NORTHERN ROCKIES AND ANOTHER LIFTS INTO THE SOUTHERN
ROCKIES. MAX TEMPS IN THE 60 TO 65 RANGE ROUGHLY SOUTH OF HIGHWAY 30
WITH 55 TO 60 TO THE NORTH. THESE TEMPS BASED ON INCREASING CLOUD
COVER AS THE DAY PROGRESSES. BUT IF THERE IS MORE SUNSHINE THEN
TEMPS MAY BE SOMEWHAT HIGHER. HOWEVER A BIG PROBLEM COULD BE STRATUS
FORMING UNDER THE STRENGTHENING INVERSION EARLY FRIDAY THAT IF
LINGERS TOO LONG WOULD PUT A BIG DENT INTO THE WARM TEMPS. BASED ON
THIS CURRENT FORECAST RECORD HIGHS ARE NOT IN JEOPARDY. SEE CLIMATE
SECTION BELOW. PREVIOUS SHIFT HAD REMOVED MENTION OF RAIN FOR FRIDAY
AND BASED ON LATEST DATA THIS STILL LOOKS GOOD. SHOULD HAVE SOUTH
WINDS GUSTING TO AROUND 30 MPH.
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE 00Z ECM HAS SLOWED THE
PHASING OF THE TWO STREAMS AND KEEPS MUCH OF THE CWA DRY FRIDAY
EVENING...AND IN FACT KEEPS OUR FAR EASTERN CWA TOTALLY DRY FRIDAY
NIGHT. OTHERWISE WILL GRADUALLY WORK THE LIKELY POPS EASTWARD AS
MOST OF THE OPERATIONAL MODELS PAINT A WET NIGHT. RAINY DAY ON
SATURDAY MOST OF THE CWA EXCEPT OUR WESTERN CWA WHERE WE WILL HAVE A
CHANCE. TIMING THE ENDING OF THE RAIN VARIES UPON THE MODELS AND
LATER SHIFTS MAY NEED TO ADJUST. WIDESPREAD 0.20 TO 0.40 INCH RAIN
AMOUNTS STILL APPEAR LIKELY. ANY RAIN THAT CHANGES TO SNOW SHOWERS
AT THE TAIL END OF THIS EVENT BY SATURDAY NIGHT LOOKS SHORT-LIVED
AND UNEVENTFUL AS OF NOW. BACK TO REALITY AS MUCH COLDER AIR RETURNS
ON SATURDAY WITH STRONG COLD ADVECTION. MAX TEMPS ONLY IN THE MID
40S TO LOWER 50S...ALONG WITH NORTHWEST WINDS GUSTING OVER 30 MPH
ADDING TO THE CHILL. A RATHER WET AND RAW DAY ON SATURDAY.
SUNDAY THROUGH WEDNESDAY...INTERESTING THAT THE PAST COUPLE OF RUNS
OF THE ECM SHOWED EITHER A PROGRESSIVE TROUGH MOVING ACROSS THE
EASTERN UNITED STATES EARLY NEXT WEEK...OR A CLOSED LOW FORMING WELL
TO OUR EAST. AMAZINGLY THE 00Z RUN NOW IS DEPICTING THE CLOSED LOW
FARTHER TO THE WEST FORMING IN THE GULF STATES AND MOVING INTO THE
OHIO VALLEY. THE PRECIPITATION JUST GRAZES OUR FAR SE CWA. THE
GFS/GEM INDICATE A DIGGING TROUGH IN THE EASTERN STATES KEEPING THE
PRECIPITATION WELL EAST OF THE DVN CWA. BASICALLY FOR THE PAST 7
DAYS THE GFS/ECM HAVE BEEN ERRATIC AND SHOWING A LOT OF FLIP-
FLOPPING. THEREFORE THE EXTENDED REMAINS LOW CONFIDENCE. OTHER THAN
A SLIGHT CHANCE OF SNOW SHOWERS EAST OF THE MS RIVER ON SUNDAY THE
EXTENDED INDICATES DRY AND CHILLY WEATHER FOR NOW.
IF THE ECM IS CORRECT THE RECORD COLD ARCTIC AIR THAT HAS BEEN
BUILDING IN ALASKA THE PAST SEVERAL WEEKS WILL BE GETTING CLOSER AND
CLOSER THE FIRST WEEK OF DECEMBER. FAIRBANKS HAS NOT BEEN ABOVE ZERO
FOR THE PAST 10 DAYS. THE ARCTIC OSCILLATION IS ALSO FORECAST TO
START GOING NEGATIVE DURING THAT TIME. THIS MAY ALSO INCREASE THE
POTENTIAL FOR A SNOWSTORM.
..HAASE..
&&
.AVIATION... /ISSUED 1135 PM CST WED NOV 23 2011/
THE STRATUS REMAINS IN PLACE OVER THE EASTERN THIRD OF IOWA AND
HAD EXPANDED ACROSS NORTHERN IL LATE THIS EVENING. WITH VERY
LITTLE CHANGE IN THE LOCATION OF THE BACK EDGE OF THE STRATUS THIS
EVENING...IT APPEARS THAT THE CLOUDS WILL REMAIN OVER THE AREA
MUCH OF THE NIGHT WITH MAINLY IFR CIGS. AS LONG AS THE CLOUDS ARE
IN PLACE...VISIBILITIES SHOULD REMAIN IN THE 3 TO 5SM RANGE DUE TO
FOG. AS THE SOUTHWEST LOW LEVEL FLOW INCREASES LATE TONIGHT AND
THURSDAY MORNING...THE CLOUDS SHOULD START ERRODING FROM WEST TO
EAST. HAVE CLEARED TAF SITES OUT BETWEEN 12Z AND 15Z. EXPECT VFR
CONDITIONS THE REST OF THE PERIOD WITH SOUTHWEST WINDS GUSTING TO
AROUND 20 KTS BY THURSDAY AFTERNOON. ..DLF..
&&
.CLIMATE...
RECORD HIGHS FOR NOVEMBER 24...
MOLINE.........66 IN 1966
CEDAR RAPIDS...63 IN 1931
DUBUQUE........63 IN 1931
BURLINGTON.....68 IN 1915
RECORD HIGHS FOR NOVEMBER 25...
MOLINE.........67 IN 1896
CEDAR RAPIDS...68 IN 1896
DUBUQUE........65 IN 1896
BURLINGTON.....68 IN 1915
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1140 PM EST WED NOV 23 2011
.SYNOPSIS...
AFTER SOME CLOUDS OVERNIGHT TONIGHT INTO THE MORNING HOURS...HIGH
PRESSURE WILL BRING CLEARING SKIES AND SEASONABLY MILD TEMPERATURES
FOR THANKSGIVING DAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
CLOUDS ARE FORMING ALONG THE RIDGES...WITH A LARGE AREA OF LOW
CLOUDS MARCHING ACROSS WESTERN OHIO. HI RES MODELS SHOW THE AREA
TO THE WEST ENVELOPING EASTERN OHIO IN HE NEXT 2-4 HOURS...MOVING
INTO WESTERN PA AROUND SUNRISE. FURTHER EAST...THE CLOUD DECK
THERE LOOKS TO BE EXPANDING TO THE WEST AND EAST. GIVEN THESE
CONDITIONS...WILL INCREASE SKY COVER GRADUALLY OVERNIGHT TO
MOSTLY CLOUDY TO OVERCAST AREA WIDE BY MORNING. THINK THIS
DECK WILL DISSIPATE BY LATE MORNING...WITH HIGH PRESSURE GIVING
A MOSTLY SUNNY THANKSGIVING AFTN. LOWER TO MID 30S WILL PREVAIL
FOR LOWS TNGT...WITH LOWER/MID 50S FOR HIGHS THANKSGIVING DAY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
LARGE DOME OF HIGH PRESSURE WILL COVER THE EASTERN THIRD OF THE
NATION THROUGH PERIOD WITH TEMPERATURES AVERAGING ABOVE NORMAL AND
GENERALLY CLEAR SKIES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
LATEST MEDIUM RANGE MODELS CONTINUE TO SHOW A SHARP UPPER TROUGH
PUSHING INTO THE EASTERN STATES EARLY NEXT WEEK...BUT GFS AND ECMWF
STILL DIFFER ON WHERE AND WHEN SOUTHERN BRANCH TROUGH WILL CLOSE
OFF. WENT CLOSE TO HPC GUIDANCE WHICH PUSHES A COLD FRONT THROUGH
THE UPPER OHIO VALLEY SUNDAY AND THEN DEVELOPS A SURFACE LOW OVER
THE MID ATLANTIC REGION MONDAY INTO EARLY TUESDAY. LIKELY POPS FOR
SHOWERS ARE FORECAST FOR SUNDAY INTO SUNDAY NIGHT WITH COVERAGE
BECOMING MORE SCATTERED MONDAY INTO TUESDAY.
ANOTHER UPPER TROUGH WILL SWING INTO THE GREAT LAKES REGION AND WILL
BRING A REINFORCING SHOT OF COLDER AIR AND SCATTERED PRECIPITATION
EARLY WEDNESDAY.
ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL GRADUALLY COOL DOWN
TO A FEW DEGREES BELOW NORMAL BY WEDNESDAY.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
FORECAST PROBLEM FOR THE SHORT TERM IS THE AREA OF IFR/LIFR STRATUS
DEVELOPING IN THE STRONG WAA. MAIN AREA IS TO THE WEST, WITH A
SMALLER AREA FILLING IN OVER THE RIDGES. CURRENT HI RES MODELS
INDICATE THAT THE AREA TO THE WEST WILL EXPAND EASTWARD DURING THE
OVERNIGHT HOURS, WHILE THE AREA EAST WILL ALSO FILL INTO THE WEST.
THIS WILL NEED TO BE MONITORED CLOSELY, BUT WITH HI RES MODELS AND
TO AN EXTENT, LATEST NAM RUN, SHOWING THIS EXPANSION, WILL NEED TO
BRING IN IFR/LIFR CIGS TO ALL PORTS AS DAWN APPROACHES. WILL USE
TIMING FROM HRRR MODEL, IN THE WEST, RESTRICTIONS WILL BEGIN AT ZZV
AROUND 08Z AND THEN REACH PIT AROUND 12Z. IN THE EAST, WILL BEGIN
FORECAST WITH MVFR CIGS AT LBE AND MGW, THEN MAY NEED TO LOWER
FURTHER AS DAWN APPROACHES. OBVIOUSLY, IF EXPANSION OF LOW CIGS DOES
NOT TAKE PLACE, WILL NEED TO MAKE MAJOR CHANGES TO FORECAST.
MODEL DATA IS SHOWING THAT THE LOWER CLOUDS SHOULD DISPERSE RAPIDLY
BY MID-MORNING ONCE THE ATMOSPHERE BEGINS THE MIXING PROCESS.
EXPECT A RETURN TO VFR CONDITION FOLLOWING THE ELIMINATION OF THE
STRATUS.
OUTLOOK... THURSDAY NIGHT THROUGH MONDAY...
VFR INTO SATURDAY EVENING. PREFRONTAL SHOWERS WITH RESTRICTIONS
POSSIBLE STARTING LATE SATURDAY NIGHT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
400 AM EST THU NOV 24 2011
LATEST UPDATE...SYNOPSIS/SHORT AND LONG TERM/MARINE...
.SYNOPSIS...(400 AM EST THU NOV 24 2011)
THANKSGIVING DAY WILL SEE SOME CLOUDS MOVE IN WITH HIGHS IN THE
UPPER 40S. NO RAIN IS EXPECTED UNTIL THE WEEKEND WHEN A COLD FRONT
MOVES THROUGH. RAIN SHOWERS COULD MIX WITH WET SNOW BY SUNDAY NIGHT
AS COLDER AIR MOVES IN BEHIND THE COLD FRONT.
&&
.SHORT TERM...(400 AM EST THU NOV 24 2011)
(TODAY THROUGH SATURDAY)
FORECAST PROBLEMS IN THE NEAR TERM INCLUDE LOW CLOUDS AND POTENTIAL
IMPACT ON MAX TEMPS TODAY AND TIMING IN THE RAIN ON SATURDAY.
LOWERED MAXES FROM THE LOWER 50S TO UPPER 40S FOR TODAY AS SATELLITE
AND OBS SHOW AREA OF LOW STRATUS MOVING INTO THE WESTERN FORECAST
AREA ATTM. MAX TEMPS WERE HELD TO THE LOWER 40S ACROSS IOWA ON
WEDNESDAY AFTERNOON UNDER THESE CLOUDS.
00Z NAM RH PROFILES SHOW INVERSION SLOWLY LOWERING AND SUGGESTS
CLOUDS COULD BREAK UP THIS AFTERNOON...BUT LATEST RUC IS MORE
PESSIMISTIC AND WOULD MEAN A CLOUDY DAY AND MAXES PROBABLY HELD IN
THE MID 40S. STRATUS MAY HANG ON EVEN INTO TONIGHT AND POSSIBLE
FRIDAY MORNING BEFORE INCREASING WINDS AND MIXING SCOUR THEM OUT.
KEPT CHANCE POPS UP NORTH FOR FRIDAY NIGHT AS SOME ISENTROPIC ASCENT
AND MID LEVEL MOISTURE IS AVAILABLE. THE STEADIER RAIN SHOULD
HOLD OFF UNTIL AFTER 12Z SATURDAY AND POSSIBLY UNTIL 00Z SUNDAY IF
THE SLOWER EURO SOLUTION PANS OUT...AS DIGGING SHORTWAVE TROUGH
APPROACHES AND COUPLED JET ALONG WITH DEEP MOISTURE MOVES IN.
&&
.LONG TERM...(400 AM EST THU NOV 24 2011)
(SATURDAY NIGHT THROUGH WEDNESDAY)
THE MID RANGE MODELS CONTINUE TO SHOW DIFFERENCES IN THE LONG TERM.
THERE IS GOOD AGREEMENT ON THE SYSTEM SATURDAY NIGHT THROUGH SUNDAY
NIGHT. HOWEVER... CONFIDENCE IS LOWER FOR THE POTENTIAL
PRECIPITATION WITH A SYSTEM MONDAY NIGHT INTO WEDNESDAY. IN FACT...
THE ECMWF SHOWS THE WEATHER ASSOCIATED WITH A CUT OFF LOW SWEEPING
BY TO THE SOUTHEAST OF THE AREA. MEANWHILE... THE GFS HAS NO CUTOFF
LOW AND MOVES A WEAK CANADIAN WAVE BY TO THE NORTH. THEREFORE...
CONFIDENCE AND THE POPS ARE LOWER AFTER MONDAY AND SOME PERIODS HAVE
BEEN DRIED OUT. THE PRECIPITATION... IF IT OCCURS... COULD BE
RAIN... SNOW OR A RAIN/SNOW MIX.
TEMPERATURES WILL BE A LITTLE ABOVE NORMAL THROUGH THE WEEKEND. THEY
WILL BE AROUND NORMAL NEXT WEEK. NORMAL HIGHS THIS TIME OF YEAR ARE
AROUND 40 DEGREES AND NORMAL LOWS ARE IN THE UPPER 20S.
&&
.AVIATION...(1146 PM EST WED NOV 23 2011)
CERTAINLY A RISK FOR IFR OR LOWER CONDITIONS TONIGHT INTO THURSDAY.
LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE INVERSION LOCATED
ROUGHLY 2K FT OFF THE GROUND. ANY POCKETS OF CLEAR SKIES HAVE BEEN
FILLING IN WITH FOG AND STRATUS. IN ADDITION A LARGE AREA OF SUB
MVFR CLOUDS WILL ADVECT IN FROM THE SOUTHWEST BEGINNING AROUND 08Z.
IT IS BECOMING MORE LIKELY THAT THE LOW CLOUDS WILL PERSIST THROUGH
THE MORNING AND PERHAPS INTO THE AFTERNOON. EXTRA CAUTION IS
ADVISED FOR AVIATORS TONIGHT INTO THURSDAY GIVEN THIS SETUP.
ANOTHER RISK FOR LOW CLOUDS AND FOG EXISTS FOR THURSDAY NIGHT AS
WELL.
&&
.MARINE...(400 AM EST THU NOV 24 2011)
ISSUED A SMALL CRAFT ADVISORY FOR TODAY THROUGH FRIDAY NIGHT AS A
TIGHTENING PRESSURE GRADIENT WILL BRING WEST TO SOUTHWEST WINDS
GUSTING TO 25 KNOTS AND WAVES BUILDING ABOVE FOUR FEET.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY TODAY THROUGH FRIDAY NIGHT.
&&
$$
SYNOPSIS: OSTUNO
SHORT TERM: OSTUNO
LONG TERM: 63
AVIATION: MJS
MARINE: OSTUNO
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1244 AM EST THU NOV 24 2011
.SYNOPSIS...
LOW LEVEL MOISTURE BEHIND DEPARTED FRONT...CAUSES ONLY GRADUAL
BREAKUP OF CLOUDS TONIGHT...AND AREAS OF FOG WHERE IT DOES CLEAR.
DRY HIGH PRESSURE AND WARMING TEMPERATURES THANKSGIVING DAY RIGHT
INTO THE WEEKEND. WET SYSTEM BY EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
930 PM UPDATE...BACK EDGE OF THE CLEARING SKIES IS MAKING GOOD
PROGRESS EAST...NOW INTO STEUBEN AND YATES COUNTIES. THIS LINE
WILL CONTINUE TO MAKE PROGRESS EAST THROUGH THE NEXT FEW
HOURS...REACHING THE SYRACUSE AREA BY MIDNIGHT. FARTHER SOUTH AND
EAST WHILE THE SKY IS STILL EXPECTED TO CLEAR...MOISTURE FROM THE
FINGER LAKES AND THE UPSLOPE FLOW (NORTHWEST WIND) MAY KEEP SKIES
CLOUDY A BIT LONGER. STILL EXPECT EVERYONE TO CLEAR OUT...AT LEAST
CLOUD WISE...BY 10Z. BASED ON THE OBS ACROSS STEUBEN COUNTY WITH
HORNELL DOWN TO 1/4SM IN FOG...EXPECT AREAS OF FOG TO FORM
OVERNIGHT AND IT COULD BE QUITE DENSE GIVEN OUR RECENT RAINFALL.
WILL CONTINUE TO HIGHLIGHT AREAS OF FOG IN THE GRIDS.
ONE MORE THING TO ADD....WITH THE RUC SHOWING THE CORE OF COLD AIR
OVER THE FINGER LAKES NOW (-3C) AND A WIND OUT OF THE
NORTHWEST...KBGM IN CLEAR AIR MODE IS SHOWING SOME LIGHT ECHOES
DOWNWIND OF CAYUGA AND OWASCO LAKES (LAKE EFFECT FLURRIES). THROUGH
MIDNIGHT SOME SCT. FLURRIES ARE POSSIBLE...MAINLY ACROSS THE
HIGHER TERRAIN...ACROSS
TOMPKINS...CORTLAND...TIOGA...BROOME...BRADFORD...SUSQUEHANNA...AND
WAYNE COUNTIES.
AT 3 PM...FRONT IS WELL EAST OF THE AREA...BUT UPPER TROUGH
AXIS IS STILL FINISHING ITS TREK THROUGH THE AREA...AS CLEARLY
MARKED VIA MOISTURE SPOKE ON THE WATER VAPOR IMAGERY LOOP. UPPER
TROUGH AXIS AND WEAKENING MID LEVEL DEFORMATION ARE PAIRED UP OVER
THE EASTERN HALF OF THE AREA...YET DEEPER MOISTURE IS ALREADY WELL
TO OUR EAST. SO WITH SHALLOW SATURATED LAYER...ONLY DIMINISHING
LIGHT SHOWERS AND PATCHY DRIZZLE EARLY THIS EVENING. OUR HIGH
TEMPS OCCURRED EARLY TODAY...YET BECAUSE TEMPERATURE WITHIN THE
SHALLOW SATURATED LAYER STAYS ABOVE MINUS-5 DEGREES CELSIUS...NOT
SEEING ANY OPPORTUNITY FOR CRYSTAL FORMATION. THUS WITH ANY
SHOWERS THAT ARE LEFT...VERY LITTLE IF ANY MIX WITH SNOW EVEN AT
HIGHER ELEVATIONS...AND CERTAINLY NO ACCUMULATION.
TONIGHT...925MB RH FIELDS SUGGEST THAT DESPITE DRY OVERALL
AIR MASS...LOW LEVEL MOISTURE FROM LAKE ONTARIO...AND IN
GENERAL...GETS TRAPPED UNDER DEVELOPING INVERSION AS WARM AIR
ADVECTION ALREADY BEGINS ALOFT OVERNIGHT. THE WET GROUND FROM 1-2
INCHES OF PRIOR RAINFALL ALSO WILL AID IN MOIST LOW LEVELS.
THUS...LOW CLOUDS WILL BE VERY STUBBORN TO BREAK...AND SKY GRIDS
HAVE BEEN ADJUSTED ACCORDINGLY. THOSE AREAS THAT DO CLEAR COULD
HAVE AREAS OF FOG FORM BECAUSE OF THE WET GROUND...WITH WET GROUND
AND WEAKENING/DECOUPLING WINDS. AREAS WEST OF I-81 HAVE THE BEST
CHANCE FOR FOG FORMATION. WE WILL HAVE TO MONITOR FOR PROSPECTS OF
FREEZING FOG EARLY IN THE MORNING IF IT MANAGES TO GET LOCALLY
DENSE. WITH AMOUNT OF LOW LEVEL MOISTURE...I EXPECT LOW
TEMPERATURES TONIGHT TO BE SLIGHTLY ABOVE MODEL GUIDANCE NUMBERS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
HIGH PRESSURE RIDGE AT SURFACE AND ALOFT TAKES OVER FOR
THANKSGIVING AND FRIDAY. IN ADDITION TO ABUNDANT SUNSHINE...THE
SOUTHWEST SURFACE FLOW AROUND THE HIGH CENTERED TO OUR SOUTH...AND
RISING THICKNESSES...ALL HELP YIELD WARMING
TEMPERATURES...ESPECIALLY FRIDAY AND SATURDAY WITH HIGHS ABOUT 15
TO 20 DEGREES ABOVE NORMAL. ONLY FLY IN THE OINTMENT IS THAT
MOISTURE WILL STILL BE COMING OFF OF LAKE ONTARIO INITIALLY
THURSDAY...WHICH MAY MEAN SOME CLOUD COVER IN ONEIDA COUNTY...YET
STILL TEMPERATURES WILL BE IN A WARMING TREND THERE.
A NORTHERN STREAM FRONTAL BOUNDARY WILL ATTEMPT TO SAG SOUTH
FRIDAY NIGHT TO SATURDAY MORNING...BUT AT THIS TIME I AGREE WITH
NAM/GFS IN NOT BRINGING IT CLOSE ENOUGH TO IMPACT OUR WEATHER
OTHER THAN PERHAPS A FEW EXTRA CLOUDS IN THE NORTHERN ZONES.
HOWEVER CLOSE THAT FRONT APPROACHES...IT WILL SURGE BACK NORTHWARD
SATURDAY WITH INCREASING SOUTHWESTERLY FLOW.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MAIN FOCUS IN THE MEDIUM RNG IS THE AMPLIFYING TROF WHICH IS
FORECAST TO MOV INTO THE CNTRL AND THE ERN U.S. EARLY NXT WEEK.
THERE ARE SIG DIFFS IN THE MDLS W/RESPECT TO TIMING...PCPN
AMTS...AND NRN/SRN STREAM INTERACTION. GFS PAINTS A POTNL FLOOD
SCENARIO WITH SRN PORTION OF THE TROF CUTTING OFF THEN LIFTING
NEWD...WITH +RA ACRS THE FSCT AREA SUN NGT INTO MONDAY ALONG AN
INVERTED TROF. THE EURO SHOWS LESS INTERACTION BETWEEN NRN AND SRN
STREAMS...BUT STILL SHOWS RAIN WORKING NWD INTO THE RGN LATE MON
NGT INTO TUE...BUT THE HEAVIEST PCPN IS SHUNTED OFF TO OUR
SOUTHEAST. GIVEN THESE DIFFS...WE LEANED HEAVILY ON HPC GUIDANCE
FOR THE MEDIUM RNG..WHICH PAINTS AN UNSETTLED PICTURE INTO
MIDWEEK.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
SOME GRADUAL CLRG ATTM BUT WITH PLENTY OF LL MOISTURE STILL
ARND...PTCHY IFR CIGS AND VSBYS PSBL THRU THE NGT. ON THU...DRIER
AIR ALOFT WILL HELP MIX OUT THE MOISTURE AND RETURN ALL STATIONS
TO VFR. VFR CONDS SHD REMAIN THRU THE END OF THE PD WITH THE DRY
AIR.
OUTLOOK...
THU THROUGH SAT...VFR.
SUN NGT/MON...IFR/MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...HEDEN/MDP
SHORT TERM...MDP
LONG TERM...
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1230 AM EST THU NOV 24 2011
.SYNOPSIS...
LOW PRESSURE IS EXITING EASTWARD THROUGH THE GULF OF MAINE. IN
THE WAKE OF THE LOW PRESSURE SYSTEM...A RIDGE OF HIGH PRESSURE
WILL BUILD EASTWARD ACROSS THE NORTH COUNTRY BRINGING DRY WEATHER
FOR THANKSGIVING AND RIGHT THROUGH THE UPCOMING WEEKEND.
TEMPERATURES WILL BE NEAR NORMAL FOR THANKSGIVING WITH HIGHS IN
THE UPPER 30S...THEN MODERATING TO ABOVE AVERAGE READINGS FOR
FRIDAY THROUGH NEXT MONDAY. THE NEXT CHANCE FOR PRECIPITATION
WILL BE LATE SUNDAY INTO MONDAY AS A FRONTAL BOUNDARY APPROACHES
THE AREA FROM THE WEST.
&&
.NEAR TERM /UNTIL 11 AM THIS MORNING/...
AS OF 1212 AM EST THURSDAY...NO CHANGES PLANNED TO GOING FORECAST
ATTM. LL CLD COVER REMAINS INTACT OVER THE NORTH COUNTRY...WITH NO
REAL SIGNS OF ANY SCOURING OUT TAKING PLACE. SO WILL KEEP CWA
CLOUDY. TEMPS SLOWLY DROPPING DESPITE CLDY SKIES...AIDED THOUGH BY
WK NORTHERLY FLOW. TRENDS LOOK GD.
PREVIOUS DISCUSSION...MADE SOME MINOR ADDITIONAL ADJUSTMENTS
TO SKY COVER THROUGH TOMORROW AFTERNOON BASED OFF CURRENT
OBSERVATIONS AND LATEST NEAR-TERM MODEL DATA. RUC13 275K
ISENTROPIC PROGS SEEM TO CAPTURE CURRENT SITUATION NICELY INTO THE
OVERNIGHT HOURS...WITH CLOUDS ESSENTIALLY HANGING TOUGH...ESP THE
NORTHWESTERN HALF OF THE FORECAST AREA DESPITE LOW PRESSURE
PULLING WELL EAST INTO THE MARITIMES. AS FLOW ALOFT TRENDS
WESTERLY LATER TONIGHT...SOME CLEARING LIKELY IN THE CT RIVER
VALLEY...AND POSSIBLY INTO THE SLV. ELSEWHERE GENERALLY MOSTLY
CLOUDY TO CLOUDY. THIS WILL TEMPER OVERNIGHT LOWS ABOVE 12/18Z MOS
GUIDANCE...WITH VALUES GENERALLY BOTTOMING OUT IN THE 20S...THOUGH
LOCALLY TEENS IN THE NRN CT RVR VALLEY FROM ORANGE COUNTY
NORTHWARD. OUTSIDE A STRAY FLURRY...NO ADDITIONAL PCPN EXPECTED
OVERNIGHT AS NORTHERLY WINDS TREND LIGHT.
FOR THANKSGIVING DAY...A DRY FORECAST WITH RISING HEIGHTS ALOFT.
AS MENTIONED ABOVE I`VE MADE SOME ADDITIONAL CHANGES TO SKY
COVER...KEEPING MAINLY CLOUDY SKIES ACROSS OUR CENTRAL/NRN
COUNTIES...AND OFFERING PTLY SUNNY CONDS SOUTH. AIR MASS IS
SLOWLY MODERATING...BUT GENERALLY EXPECTING HIGHS FROM THE MID 30S
ACROSS ERN VT TO THE UPR 30S IN THE CHAMPLAIN VALLEY. WARMEST
TEMPS EXPECTED IN THE ST. LAWRENCE VALLEY /LOW TO MID 40S/. SNOW
COVER WILL HELP HOLD DOWN TEMPS SOMEWHAT FROM THE ADIRONDACKS EWD
ACROSS VT. WINDS WILL START LIGHT...THEN BECOMING S-SW AT 5-10 MPH
IN THE AFTN.
&&
.SHORT TERM /11 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 247 PM EST WEDNESDAY...A QUIET PERIOD OF WEATHER EXPECTED
FOR THE SHORT-TERM PERIOD WITH NIL POPS. SFC RIDGE AXIS SHIFTS
SOUTH OF NEW ENGLAND ALLOWING FOR A STRONGER WSWLY GRADIENT FLOW
TO DEVELOP OVER THE NORTH COUNTRY. WINDS ON FRIDAY COULD BECOME
LOCALLY BREEZY...GENERALLY SOUTHWEST 15-25 MPH. THERE WILL ALSO
BE MODERATING TEMPERATURES DURING THE PERIOD. LOWS THURSDAY NIGHT
WILL GENERALLY BE 25-30F...THOUGH LOCALLY COLDER READINGS ARE
POSSIBLE IN FAR NERN VT. WITH 850MB THERMAL RIDGE AXIS IN
PLACE...HIGHS BOUNCE BACK TO THE UPR 40S ON FRIDAY AND A FEW LOW
50S ACROSS NRN NY. THIS WILL ALLOW FOR SOME MELTING OF RECENT
SNOWFALL. THERE MAY BE A TENDENCY FOR A FRONTAL BOUNDARY TO
DEVELOP ALONG THE INTL BORDER FRIDAY INTO FRIDAY NIGHT. CLOUD
FORECAST IS GENERALLY PARTLY TO MOSTLY CLOUDY...WITH THE GREATER
CLOUD AMTS ACROSS NRN AREAS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 330 PM EST WEDNESDAY...HIGH PRESSURE IS EXPECTED TO
CONTINUE FROM SATURDAY THROUGH EARLY SUNDAY...WITH DRY WEATHER
AND ABOVE-NORMAL TEMPERATURES. EUROPEAN AND GFS CONTINUE TO
DISAGREE WITH RESPECTS TO THE SUNDAY THROUGH WEDNESDAY TIME
PERIOD. BOTH MODELS SHOW A LOW PRESSURE SYSTEM LIFTING NORTH OF
THE REGION ON SUNDAY...WITH BULK OF PRECIPITATION SUNDAY
NIGHT....MAINLY RAIN SHOWERS IN THE VALLEYS WITH SOME SNOW MIXING
IN THE HIGHER ELEVATIONS. MODELS DIVERGE GREATLY AFTER SUNDAY
NIGHT...WITH THE GFS KEEPING AFOREMENTIONED FRONT AROUND THROUGH
TUESDAY AND LIFTING A CUT OFF LOW ACROSS THE REGION. ECMWF DOES
NOT HAVE THIS FEATURE AT ALL. THEREFORE...CAN NOT PUT MUCH WEIGHT
BEHIND EITHER OF THESE MODELS. WOULD LIKE TO SEE MODELS COME INTO
BETTER AGREEMENT WITH RESPECT TO THE EXTENDED. AT THIS TIME BEST
CHANCE FOR PRECIP IN THE EXTENDED LOOKS TO BE SUNDAY INTO SUNDAY
NIGHT.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
THROUGH 06Z FRIDAY...ABUNDANT LOW-LEVEL MOISTURE WILL REMAIN OVER
THE REGION INTO THURSDAY WITH WIDESPREAD MVFR AND LOCAL IFR
CEILINGS. BY 13Z ALL TAF SITES EXPECTED TO BE MVFR...WITH A TREND
TO VFR BY 18Z. EXCEPTIONS WILL BE KSLK/KMSS WHERE MVFR CIGS MAY
PERSIST THROUGH THE PERIOD. LIGHT NORTH WINDS OVERNIGHT WILL
BECOME SOUTH TO SOUTHWEST ON THURSDAY AS HIGH PRESSURE PASSES
WELL SOUTH OF THE AREA.
OUTLOOK 06Z FRIDAY THROUGH MONDAY...VFR CONDITIONS EXPECTED
THROUGH SUNDAY AS A RIDGE OF HIGH PRESSURE BUILDS OVER THE
REGION. SHOWERS WITH MVFR CONDITIONS EXPECTED SUNDAY NIGHT AND
MONDAY AS A FRONTAL SYSTEM MOVES SLOWLY ACROSS THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...JMG/JN
SHORT TERM...BANACOS
LONG TERM...NEILES
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
406 AM EST THU NOV 24 2011
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE OVER THE LOWER OHIO VALLEY WILL
SLOWLY MOVE EAST THROUGH THE END OF THE WEEK. LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE PLAINS FRIDAY AND APPROACH THE GREAT
LAKES REGION SATURDAY. THE COLD FRONT FROM THE LOW PRESSURE IS
EXPECTED TO CROSS THE AREA SATURDAY NIGHT AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE TO THE SOUTH WILL KEEP THE AREA DRY TODAY...BUT THE
SIGNIFICANT WEATHER FEATURE OF TODAY WILL BE THE LOW CLOUDS THAT
HAVE BEEN ADVANCING EASTWARD ACROSS THE FORECAST AREA OVERNIGHT.
IR SAT SHOWING A LARGE AREA OF LOW STRATUS CLOUDS EXTENDING BACK
INTO IN AND IL THIS MORNING. THERE ARE SOME BREAKS IN THE CLOUDS
ACROSS THE WESTERN HALF OF THE AREA...BUT THINKING EVEN THIS AREA
WILL FILL IN BY AROUND OR JUST SUNRISE THIS MORNING.
MAV AND MET GUIDANCE WAY OFF THIS MORNING HANDLING THESE LOW
CLOUDS...SO ACTUALLY LEANED TOWARD THE HRRR MODEL FOR THIS
SITUATION. RECENT RUNS SINCE AROUND 04Z HAVE HANDLING THE LOW
CLOUDS FAIRLY WELL BRINGING THEM INTO THE AREA...AND THE HRRR
ACTUALLY PERSISTS THEM THROUGH MUCH OF THE DAY. LEANED TOWARD THIS
SOLUTION WITH A MAINLY CLOUDY FORECAST FOR TODAY ACROSS THE AREA
WITH SOME BREAKS POSSIBLE LATE AFTN/AROUND SUNSET THIS EVENING.
WITH THE ADDED CLOUDS IN THE FORECAST ALSO HAD TO ADJUST TEMPS
ACCORDINGLY. LOWERED TEMPS TO MAINLY UPPER 40S TO AROUND 50 FOR
TODAY WITH LITTLE RISE THROUGH THIS MORNING. MY CONCERN IS THAT IF
THE LOW STRATUS CLOUDS DO DOMINATE THROUGH THE ENTIRE AFTERNOON
THAT TEMPS TODAY MAY END UP EVEN COOLER THAN FORECAST. THEN RATHER
THAN A NORMAL DIURNAL CURVE TEMPS SIMPLY JUST CONTINUE TO SLOWLY
RISE THIS EVENING AND TONIGHT WITH WAA. FOR NOW WILL PROTECT
EITHER SOLUTION AND ALLOW THE FORECAST TEMPS TO BE A COMPROMISE
BETWEEN POSSIBLE SOLUTIONS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
HIGH PRESSURE TO THE SOUTH WILL REMAIN IN CONTROL TONIGHT THROUGH
FRIDAY NIGHT. GUIDANCE SUGGESTING THAT THE CLOUDS SHOULD DISSIPATE
TONIGHT ALLOWING FOR MOSTLY CLEAR TO PARTLY CLOUDY SKIES. WILL
LEAN TOWARD THAT TREND FOR NOW...BUT WILL BE SOMETHING WORTH
WATCHING THROUGH TODAY. TEMPS WILL BE TRICKY REGARDING THE
OVERNIGHT TRENDS...BUT OVERALL LOOKING FOR A MILDER NIGHT TONIGHT.
WITH INCREASING SOUTHERLY FLOW TEMPS WILL BE MILD ON FRIDAY AND
THEN EVEN A FEW BETTER ON SAT AHEAD OF AN APPROACHING COLD FRONT.
MADE LITTLE CHANGES TO TEMPS FRIDAY NIGHT THRU SAT NIGHT AS LIKED
LEANING ON THE WARMER SIDE OF CURRENT GUIDANCE. ALSO MADE LITTLE
CHANGES TO POPS THROUGH SAT NIGHT WITH LIKELY ALREADY MENTIONED IN
SOME AREAS. KEPT POPS RATHER HIGH IN THE LIKELY CATEGORY ON SUNDAY
WITH THE ECMWF A BIT SLOWER...BUT DID TREND TO LOWERING POPS
ACROSS THE WEST SUNDAY NIGHT. FOR SUNDAY AND SUNDAY NIGHT MADE
LITTLE CHANGES DUE TO TIMING ISSUES WITH THE FRONT...AS WELL AS
AIRMASS DIFFERENCES BETWEEN THE COOLER GFS AND WARMER ECMWF.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
LIKE YESTERDAY...MODELS CONTINUE TO HAVE SIGNIFICANT DIFFERENCES
DURING THE LONG TERM PERIOD. THE GFS CONTINUES TO BE COLDER AND
FASTER WITH THE MAIN FEATURES. HAVE NOT MADE MANY CHANGES TO THE
LONG TERM DURING THE PERIOD GIVEN THIS UNCERTAINTY. APPEARS THAT
NEARLY EVERY PERIOD WILL SEE AT LEAST A CHANCE FOR PRECIPITATION.
IT COULD BE COLD ENOUGH FOR MIXED SNOW AND RAIN BOTH TUESDAY AND
WEDNESDAY NIGHTS WITH LIQUID PRECIPITATION DURING THE DAY.
TEMPERATURES DURING THE PERIOD WILL AVERAGE WITHIN A DEGREE OR TWO
OF NORMAL.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
BAND OF STRATUS OVER WESTERN OHIO CONTINUING TO MOVE EAST AND
EXPAND. ANOTHER AREA OF STATUS MOVING RAPIDLY NORTHEAST FROM
CENTRAL INDIANA. THE MODELS DO NOT HAVE A HANDLE ON THIS WHICH IS
TYPICAL FOR THIS TIME OF YEAR WHEN LOW LEVEL MOISTURE GETS TRAPPED
BELOW THE INVERSION. MY FORECAST IS FOR THE STRATUS TO EVENTUALLY
COVER THE ENTIRE FORECAST AREA BY DAYBREAK THURSDAY. THE VISIBILITY
SHOULD BE MAINLY MVFR BUT COULD FLUCTUATE TO IFR AT TIMES. THE
CEILING SHOULD BE MAINLY IFR BUT COULD IMPROVE TO MVFR AT TIMES.
CONDITIONS SHOULD BE WORSE AT DAYBREAK. WITH THE TIME OF THE YEAR
THE CEILINGS MAY JUST GO BROKEN DURING THE AFTERNOON. NOT EXPECTING CLEAR
SKIES AS THE SURFACE RIDGE WILL BE EAST OF THE AREA...SO NO REAL
SUBSIDENCE. THURSDAY AFTERNOON CEILINGS MAY BE NEAR 1000 FEET WITH
THE VISIBILITY 6SM OR BETTER. CONDITIONS WILL BEGIN TO DETERIORATE AGAIN
THURSDAY NIGHT.
OUTLOOK...NON VFR SATURDAY NIGHT THROUGH SUNDAY NIGHT.
&&
.MARINE...
PERSIST WSW TO SW FLOW IS EXPECTED ON LAKE ERIE TILL A COLD FRONT
CROSSES THE LAKE SOMETIME SATURDAY NIGHT. WILL HOIST A SMALL CRAFT
FOR ABOUT THE EAST HALF OF THE AREA AS LOCAL SCHEMES AND MODELS ARE
GIVING 4 FOOT OR GREATER WAVES. THE FLOW WILL BECOME WESTERLY
BEHIND THE FRONT AND THEN REMAIN THAT WAY THROUGH THE END OF THE
PERIOD. LOT`S OF MODEL UNCERTAINTY DURING THE PERIOD SO THIS
FORECAST COULD BE IN FLUX...ESPECIALLY EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 3 AM EST
SATURDAY FOR LEZ147>149.
&&
$$
SYNOPSIS...ABE
NEAR TERM...ABE
SHORT TERM...ABE
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1208 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD IN TONIGHT. HIGH PRESSURE
WILL THEN REMAIN IN PLACE THROUGH THE END OF THE WEEK...GIVING US
DRY CONDITIONS AND A WARMING TREND INTO SATURDAY. A COLD FRONT
WILL APPROACH BY LATE SATURDAY WITH SHOWERS FOR SATURDAY NIGHT
INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A LARGE AREA OF STRATUS EXTENDS FROM THE CENTRAL AND WESTERN PARTS
OF OUR FORECAST AREA...SOUTHWESTWARD ACROSS SOUTHERN
INDIANA...WESTERN KENTUCKY...AND MUCH OF THE UPPER MISSISSIPPI
VALLEY. THIS MOISTURE IS TRAPPED UNDERNEATH THE RIDGE OF HIGH
PRESSURE CURRENTLY CENTERED JUST SOUTH OF OUR FORECAST AREA. THIS
CLOUD DECK WILL SLOWLY MOVE EASTWARD WITH THE RIDGE...WHICH MEANS
OUR EASTERN ZONES WILL JOIN THE REST OF THE FORECAST AREA BY
BECOMING MOSTLY CLOUDY AS WELL BY LATE TONIGHT. THIS SHOULD
PREVENT FOG FROM DEVELOPING ACROSS ANY OF OUR ZONES
OVERNIGHT. HOWEVER...THERE WILL STILL BE AREAS OF LIGHT MIST
CAUSING MINOR REDUCTIONS IN VISIBILITIES. HAVE UPDATED THE
FORECAST TO KEEP CLOUD COVER IN PLACE THROUGH SUNRISE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
HIGH PRESSURE WILL BE CENTERED ACROSS THE OHIO VALLEY AS IT SLOWLY
WORKS OFF TO THE EAST. ANY MORNING LOW LEVEL MOISTURE CLOUDS THAT
MIGHT HAPPEN TO DRIFT INTO THE AREA SHOULD DIMINISH. TEMPS NEAR
GUIDANCE THROUGH PERIOD EXCEPT A BIT LOWER THURSDAY NIGHT AND
LITTLE WARMER FRIDAY NIGHT WITH SOUTHERLY FLOW WITH DRY
CONDITIONS THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
A STRONG COLD FRONT WITH COPIOUS MOISTURE WILL APPROACH THE AREA ON
SATURDAY. WITH GFS TRENDING FASTER WITH RESPECT TO THIS
SYSTEM...SPED UP ONSET OF CHANCE OF SHOWERS TO SATURDAY AFTERNOON IN
WESTERN COUNTIES. ENTIRE AREA SHOULD SEE SHOWERS SATURDAY NIGHT AND
SUNDAY AS THE FRONT PUSHES THROUGH. KEPT THUNDER OUT OF THE FORECAST
AS IT APPEARS THAT INSTABILITY WILL BE LACKING.
AFTER THE FRONT MOVES EAST ON SUNDAY...AN UPPER TROUGH WILL KEEP A
LOW CHANCE OF SHOWERS INTO MONDAY...MAINLY IN EASTERN COUNTIES.
ANOTHER UPPER DISTURBANCE PASSING THROUGH THE GREAT LAKES MAY BRING
A FEW SHOWERS TO NORTHERN LOCATIONS ON TUESDAY. EXPECT MAINLY DRY
WEATHER ON WEDNESDAY WITH HIGH PRESSURE PUSHING IN FROM THE
SOUTHWEST.
TEMPERATURES WILL START OUT ABOVE NORMAL ON SATURDAY AHEAD OF THE
COLD FRONT...WITH HIGHS FORECAST TO BE AROUND 60. HIGHS WILL BE NEAR
NORMAL IN THE 40S SUNDAY THROUGH TUESDAY. COLDER READINGS AROUND 40
MAY BE IN STORE FOR WEDNESDAY.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
SURFACE HIGH PRESSURE CURRENTLY CENTERED OVER THE LOWER OHIO
VALLEY WILL SLOWLY DRIFT EASTWARD OVERNIGHT INTO THURSDAY WITH LOW
LEVEL FLOW BACKING TO THE SOUTHWEST. MAIN FORECAST CONCERN FOR
THE TAF PERIOD IS THE POTENTIAL FOR LOW CEILINGS TONIGHT. A
PERSISTENT LOW STRATUS DECK OVER INDIANA... SOUTHERN
ILLINOIS...AND WESTERN KENTUCKY WAS SLOWLY ERODING EARLIER THIS
AFTERNOON. HOWEVER...NOW THAT THE SUN IS DOWN THOSE CLOUDS SHOULD
STICK AROUND FOR TONIGHT AND PERHAPS EVEN INCREASE IN AERIAL
COVERAGE AS THE LATEST RUC GUIDANCE SUGGESTS. THESE CLOUDS ARE
THE RESULT OF TRAPPED LOW LEVEL MOISTURE DUE TO A SUBSIDENCE
INVERSION ASSOCIATED WITH THE HIGH. LATEST SATELLITE IMAGERY SHOWS
A SLOW EASTWARD PROGRESSION WITH THIS CLOUD DECK...ALREADY
ENCROACHING ON KCVG. WENT WITH IFR CEILINGS TONIGHT FOR THE
WESTERN TAF SITES BASED ON WHAT HAPPENED FURTHER UPSTREAM LAST
NIGHT. MAY ALSO SEE SOME VFR TO MVFR VSBY REDUCTION AT KCVG/KLUK
DUE TO MIST...BUT EXPECT THE CLOUD DECK TO GENERALLY LIMIT MIST
DEVELOPMENT TONIGHT. CONFIDENCE IN CEILINGS IS LOWER FOR THE
EASTERN TAF SITES SO ONLY WENT WITH A SCATTERED LOW CLOUD DECK
THERE. ANY STRATUS THAT LINGERS INTO THURSDAY MORNING WILL TAKE
TIME TO ERODE...BUT WENT WITH SKC BY 17Z.
OUTLOOK...MVFR CIGS/VSBYS POSSIBLE SUNDAY AND MONDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...PADGETT
NEAR TERM...LATTO
SHORT TERM...PADGETT
LONG TERM...CONIGLIO
AVIATION...KURZ
AREA FORECAST DISCUSSION
NWS NORMAN OK
219 AM CST THU NOV 24 2011
.DISCUSSION...
CLOUD COVER...WITH CEILINGS AROUND 200 FT AND DENSE FOG...CONTINUES
TO SPREAD NORTH AND WEST THIS MORNING AROUND 15-20KT. THIS BRINGS
AREA OF LOW CLOUDS TO I-35 AROUND 11Z. HRRR WHICH IS USUALLY TOO
AGGRESSIVE...HAS LOW CEILINGS TO HWY 81 AND SOUTH OF I-40 BY 13Z.
WILL ADJUST SKY GRIDS TO REFLECT CLOUDS NEAR HWY 81 AND NORTH INTO
LINCOLN/PAYNE COUNTIES. HEATING AND INCREASING WINDS SHOULD ERODE
CLOUDS BY MID MORNING...ESPECIALLY WESTERN EDGE.
WINDS TONIGHT AND A MILD THANKSGIVING SHOULD KEEP THE FOG PONTENTIAL
LOW BUT SOME LOW CLOUDS MAY DEVELOP/MOVE INTO SOUTHERN PARTS OF
THE FA BY EARLY FRIDAY. ONLY MINOR ADJUSTMENTS WERE MADE TO
TIMING OF WX/POPS WITH FRIDAY/EARLY SATURDAY TROUGH. OVERNIGHT
LOWS FRIDAY NIGHT WILL BE A LITTLE TRICKY WITH PLACEMENT OF COLD
FRONT/CAA.
MOST OF THE RAIN SHOULD END BY MID MORNING SATURDAY. STRONG...GUSTY
NORTH WINDS SATURDAY SHOULD BE THE MAIN WEATHER STORY. RATHER DRY
AIRMASS BEHIND EARLY SATURDAY COLD FRONT WILL RESULT IN COLD
OVERNIGHT LOWS SUNDAY AND MONDAY. WITH SURFACE HIGH BUILDING SOUTH
INTO TEXAS...PER GFS...AFTERNOON TEMPERATURES USUALLY REBOUND QUICKER
THAN EXPECTED. ANOTHER COLD FRONT WILL PUSH ACROSS THE SOUTHERN
PLAINS LATE MONDAY INTO TUESDAY..BUT NO PRECIPITATION IS EXPECTED
WITH THE FRONTAL PASSAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 68 47 64 45 / 0 0 20 70
HOBART OK 67 48 64 40 / 0 0 40 50
WICHITA FALLS TX 68 48 65 46 / 0 0 40 70
GAGE OK 71 47 65 36 / 0 0 40 40
PONCA CITY OK 68 47 65 43 / 0 0 20 70
DURANT OK 68 48 65 51 / 0 0 30 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED TYPO
NWS LA CROSSE WI
354 AM CST THU NOV 24 2011
.SHORT TERM...TODAY THROUGH SATURDAY
352 AM CST THU NOV 24 2011
AT 3 AM...VLIFR/IFR CEILINGS WERE SEEN ACROSS ACROSS THE FORECAST
AREA. THESE CLOUDS HAVE BEEN SPREADING IN ALL DIRECTIONS
UNDERNEATH THE STRONG INVERSION LOCATED JUST ABOVE THE SURFACE.
OVERALL...THE HRRR HAS BEEN HANDLING THESE CLOUDS THE BEST...AND
IT SUGGESTS THAT THERE WILL BE GRADUAL DISSIPATION OF THESE CLOUDS
ON THE OUTER EDGES BETWEEN 16Z AND 18Z...AND THEN THIS PROGRESS A
BIT FASTER ACROSS THE REMAINING AREAS AS SOME DRIER AIR FROM ALOFT
MIXES DOWN.
DESPITE THE PERSISTENT CLOUDS THIS MORNING...THE COMBINATION OF
SOUTHERLY WINDS AND AFTERNOON SUSHINE WILL HELP THE TEMPERATURES
CLIMB INTO THE 50S ACROSS THE FORECAST AREA. DUE TO THE SUNSHINE
ARRIVE EARLIER...THE WARMEST TEMPERATURES /UPPER 50S/ WILL LIKELY
FOUND IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA THIS AFTERNOON. WITH
NORTH CENTRAL WISCONSIN BEING ONE OF LAST TO LOSE THE CLOUDS...SO
THEY WILL LIKELY ONLY SEE TEMPERATURES CLIMBING TO AROUND 50 DEGREES.
FOR TONIGHT...BOTH THE 24.00Z NAM AND GFS SOUNDINGS SUGGEST THAT
THE CLOUDS ACROSS NORTHERN AND EASTERN WISCONSIN WILL ONCE AGAIN
SPREAD WESTWARD ACROSS THE FORECAST AREA. THE COMBINATION OF THESE
CLOUDS AND UNUSUALLY MOIST DEW POINTS WILL RESULT IN MINIMUM
TEMPERATURES ONLY FALLING INTO THE LOWER AND MID 40S. THIS IS
ABOUT 5 DEGREES WARMER THAN OUR NORMAL HIGH TEMPERATURE FOR THIS
DATE.
ON FRIDAY...THE LOW CLOUDS WILL GRADUALLY LIFT AND DISSIPATE
DURING THE DAY. HOWEVER AT THE SAME TIME...MID AND HIGH CLOUDS
WILL BE STREAMING INTO THE REGION AHEAD OF AN APPROACHING LONG
WAVE TROUGH. AS RESULT...NOT EXPECTING TOO MUCH SUNSHINE. DESPITE
THE LACK OF ABUNDANT SUNSHINE...SOUTHERLY WINDS WILL HELP WARM
TEMPERATURES INTO THE LOWER AND MID 50S.
ON FRIDAY NIGHT...THE MODELS CONTINUE TO INDICATE THAT MODERATE TO
STRONG MOISTURE TRANSPORT WILL MOVE INTO THE FORECAST AREA. THIS
WILL BE THE BEST ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA
DURING THE EVENING. DURING THE OVERNIGHT...MODERATE TO STRONG
ISENTROPIC LIFT AND FRONTOGENESIS WILL MOVE EAST INTO THE AREA.
AT THIS TIME...IT LOOKS LIKE THE BEST RAIN CHANCES WILL BE FROM
ALONG THE MISSISSIPPI RIVER EAST. DESPITE THE RAIN...THE SOUTHERLY
WINDS SHOULD HELP KEEP THE MINIMUM TEMPERATURES UNUSUALLY WARM FOR
THIS TIME OF YEAR. THEY WILL BE IN THE LOWER AND MID 40S ACROSS
SOUTHEAST MINNESOTA AND NORTHEAST IOWA...AND IN THE MID TO UPPER
40S FOR WESTERN WISCONSIN.
ON SATURDAY AND SATURDAY NIGHT...BOTH THE GFS AND ECMWF SHOW THAT
THERE WILL BE RAPID CYCLOGENSIS OCCURRING ACROSS MINNESOTA. THIS
IS IN RESPONSE TO SOME INTERACTION BETWEEN THE NORTHERN AND
SOUTHERN SHORT WAVE TROUGH EMBEDDED IN THE LONG WAVE TROUGH. THIS
RESULT IN THE TROPOPAUSE DESCENDING TO AROUND 500 MB...AND A RAPID
TIGHTENING OF THE SURFACE PRESSURE GRADIENT. SUSTAINED WINDS WILL
CLIMB INTO THE 15 TO 30 MPH RANGE...AND THE WIND GUSTS WILL RANGE
FROM 30 TO 40 MPH.
WITH STRONG COLD AIR ADVECTION BEING FOUND IN THE WAKE OF THE
COLD FRONT ON SATURDAY...TEMPERATURES SHOULD FALL STEADILY THROUGH
THE EARLY AFTERNOON AND THEN STABILIZE. THIS TREND WAS INTRODUCED
TO THE HOURLY TEMPERATURE GRIDS. IN ADDITION...GFS SOUNDINGS ARE
COLD ENOUGH FOR A SOME SNOW TO MIX IN. THIS WAS ALREADY IN THE
SOUTHEAST MINNESOTA AND NORTHEAST FORECAST GRIDS...BUT IT NOW
LOOKS LIKE WESTERN WISCONSIN MAY ALSO SEE SOME OF THIS SNOW
TOO...SO IT WAS ADDED TO THE GRIDS DURING THE MID AND LATE
AFTERNOON.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
352 AM CST THU NOV 24 2011
ON SATURDAY NIGHT...IT CONTINUE TO LOOK LIKE THERE WILL BE SOME
LINGERING LIGHT PRECIPITATION. AS RESULT...KEPT A CHANCE OF LIGHT
RAIN AND SNOW DURING THE EVENING...AND LIGHT SNOW OVERNIGHT. LIKE
THE PAST COUPLE OF DAYS...NOT EXPECTING TOO MUCH SNOW AT ALL FROM
THIS SYSTEM. IN ADDITION TO THE MIXED PRECIPITATION...THE STRONG
WINDS WILL LIKELY CONTINUE THROUGH THE NIGHT. SUSTAINED WINDS WILL
REMAIN IN THE 15 TO 30 MPH RANGE...AND THE WINDS WILL GUST UP TO
40 MPH.
BEYOND THIS TIME PERIOD...THERE CONTINUES TO BE VERY LITTLE
CONSISTENCY. HOWEVER WITH THIS SAID...I DO LIKE THAT THE MODELS
ARE STARTING TO BECOME MORE TRANSITORY WITH THEIR SYSTEM. THIS
MAKES SENSE WHEN LOOKING AT THE RATHER ACTIVE WAVE PATTERN FROM
AFRICA INTO THE WESTERN PACIFIC. THE GFS PATTERN ACTUALLY
RESEMBLES ONE OF THE PATTERNS THAT YOU WOULD TYPICALLY SEE DURING
A LA NINA. ANOTHER FEATURE THAT WE WILL HAVE TO PAY ATTENTION TO
AS WE HEAD INTO DECEMBER IS THE INTENSIFYING MADDEN JULIAN
OSCILLATION /WHICH HAS BEEN CONSISTENTLY FORECAST BY THE
BRAZILLIAN...ECMWF...JAPANESE...AND U.S. MODEL ENSEMBLES FOR THE
PAST WEEK/ THAT IS LOCATED OVER THE WESTERN INDIAN OCEAN. THIS WILL
LIKELY CAUSE SOME ISSUES WITH THE MODEL RUN TO RUN CONSISTENCY AT
LEAST INITIALLY. IN ADDITION...IT MAY BE ONE OF THE REASONS WHY THE
CLIMATE FORECAST SYSTEM VERSION 2 MODEL IS SUGGESTING THAT AT
LEAST THE FIRST HALF OF DECEMBER MAY END UP BEING WARMER THAN
NORMAL.
&&
.AVIATION...THROUGH 06Z FRIDAY
1135 PM CST WED NOV 23 2011
STRATUS HAD DEVELOPED WESTWARD THIS EVENING AND HAS SPREAD VLIFR
CEILINGS INTO KRST WITH A LOWER MVFR CEILING AT KLSE. MODEL SOUNDINGS
SHOW THIS LOW LEVEL MOISTURE TO REMAIN TRAPPED UNDER THE INVERSION
INTO THURSDAY MORNING. THUS HAVE KEPT THE STRATUS AT BOTH TAF
SITES THROUGH AT LEAST 15Z THURSDAY AND THEN WINDS SHOULD MIX THE
MOISTURE OUT BY LATE MORNING WITH VFR CONDITIONS. WITH A RATHER
TIGHT PRESSURE GRADIENT...EXPECT SOUTHWEST WINDS TO GUST TO
BETWEEN 20 AND 25 KNOTS AT BOTH SITES...WITH THE WINDS REMAINING
AROUND 10 TO 12 KNOTS AFTER SUNSET THROUGH 06Z FRIDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
251 AM CST THU NOV 24 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
329 AM CST THU NOV 24 2011
.SHORT TERM...THANKSGIVING DAY THROUGH FRIDAY...SKY COVER AND
IT`S EFFECT ON TEMPERATURES WILL BE THE MAIN FCST CONCERNS.
WIDESPREAD LOW STRATUS HAS ONCE AGAIN OVERSPREAD THE ENTIRE CWA
THIS MORNING...DUE TO LLVL MOISTURE TRAPPED BENEATH A STRONG
INVERSION. PATCHY FOG WAS ALSO OCCURRING...ESPECIALLY OVER
NORTHERN WI...WHERE SOME SNOW PACK REMAINED.
HAVE DECIDED TO STOP FIGHTING WITH THE CLOUDS. WITH LITTLE
CHANGE IN THE PATTERN ANTICIPATED THROUGH FRIDAY...BELIEVE
THAT LOW CLOUDS WILL PERSIST. BUFKIT SOUNDINGS AND 950 MB
RH PROGS SUPPORT THIS. SOME PARTIAL CLEARING MAY OCCUR DURING
THE EARLY TO MID AFTERNOON TODAY...ESPECIALLY IN FAR NE WI...
BUT EXPECT CLOUDS TO FILL BACK IN DURING THE EVENING. WILL
ALSO CONTINUE TO MENTION PATCHY FOG TONIGHT INTO FRIDAY
MORNING...WITH AREAS OF FOG OVER THE NORTHERN WI SNOW PACK.
ANY CLEARING ON FRIDAY IS DOUBTFUL...AS LLVL MOISTURE DEEPENS
A LITTLE IN ADVANCE OF THE APPROACHING COLD FRONT.
HAVE LOWERED MAX TEMPS BY 3 TO 5 DEGREES TODAY AND FRIDAY...
WHICH SHOULD ACCOUNT FOR THE EFFECTS OF THE CLOUD COVER.
USED A BLEND OF THE BETTER PERFORMING GUIDANCE SETS FOR
MIN TEMPS TONIGHT...BUT AREAS WITH PARTIAL CLEARING COULD
QUICKLY DROP BLO THE FCST VALUES THIS EVENING...SO TEMPS WILL
NEED TO BE MONITORED.
.LONG TERM...FRIDAY NIGHT TO NEXT THURSDAY.
THE GFS ENSEMBLE MEAN INDICATES THAT AN AMPLIFYING TROUGH OVER THE
EASTERN CONUS THIS WEEKEND WILL GET REINFORCED THROUGH EARLY TO
MIDDLE OF NEXT WEEK AS FLATTENED RIDGING BUILDS OVER THE WESTERN
CONUS. OPERATIONAL MODELS CONTINUE TO STRUGGLE WITH THE EVOLUTION
OF THIS EASTERN CONUS TROUGH...AND THE POTENTIAL FOR A CUTOFF LOW TO
MEANDER OVER THE OHIO VALLEY. WILL BLEND THE ECMWF AND GFS...BUT
TRIED TO KEEP SIGNIFICANT CHANGES TO A MINIMUM.
FRIDAY NIGHT THROUGH SATURDAY NIGHT...AS A SHORTWAVE TROUGH DIGS
ACROSS THE CENTRAL GREAT PLAINS...LOW PRESSURE WILL MOVE ACROSS THE
NORTHERN MISSISSIPPI VALLEY AND INTO WESTERN WISCONSIN BY 12Z
SATURDAY. WITH UPPER DIVERGENCE INCREASING THROUGH THE NIGHT...AND
LOW LEVEL FORCING VIA A WARM FRONT DRAPED OVER NORTHERN
WISCONSIN...SHOULD SEE RAIN SHOWERS PUSH NE ACROSS THE
STATE...MAINLY AFTER MIDNIGHT AS A BEEFY DRY WEDGE IN THE MID-LEVELS
WILL HAVE TO BE OVERCOME. LOW PRESSURE THEN TRACKS ACROSS THE STATE
OF WISCONSIN ON SATURDAY...WITH SHOWERS CONTINUING. COLDER AIR WILL
EVENTUALLY WRAP AROUND THE LOW INTO THE STATE LATE SATURDAY
AFTERNOON INTO SATURDAY EVENING...WITH RAIN SHOWERS TURNING OVER TO
SNOW SHOWERS. SOME ACCUMULATIONS APPEAR POSSIBLE SATURDAY NIGHT
OVER N-C WISCONSIN...WITH AN ADDED BONUS FROM LAKE EFFECT WHICH
SHOULD BE CRANKING UP LATE SATURDAY NIGHT. WILL INCREASE POPS
SATURDAY NIGHT.
REST OF THE FORECAST...NW FLOW BEHIND THE SURFACE LOW WILL CONTINUE
INTO SUNDAY...WITH LAKE EFFECT SNOW SHOWERS PROBABLE OVER N-C
WISCONSIN AND A FEW SNOW SHOWERS LINGERING OVER THE EASTERN HALF OF
THE STATE. DRIER AIR WILL ARRIVE FOR THE AFTERNOON...BUT CYCLONIC
FLOW WILL LIKELY KEEP THE CLOUDS AROUND. NW WINDS WILL ALSO BE
GUSTY WITH SOME GUSTS TO 30 OR 35 MPH POSSIBLE. A SURFACE RIDGE
AXIS WILL QUICKLY PUSH INTO THE STATE SUNDAY NIGHT AND SO WILL
WARMER AIR...WHICH WILL ERODE ANY LINGERING LOW STRATUS. THE
REINFORCING SHORTWAVE AND COLD FRONT WILL PLOW ACROSS THE WESTERN
GREAT LAKES MONDAY INTO MONDAY NIGHT WITH ANOTHER SURGE OF COLD AIR
IN ITS WAKE. CURRENTLY CARRYING POPS MONDAY NIGHT FOR THIS
FEATURE...AND THIS LOOKS GOOD. THE COLD AIR LOOKS COLD ENOUGH FOR
LAKE EFFECT OVER NORTH-CENTRAL WISCONSIN HEADING INTO TUESDAY.
UNDER NW FLOW ALOFT...SIGNS OF ANOTHER WAVE ARRIVING WEDNESDAY NIGHT
INTO THURSDAY. OTHER THAN A BRIEF WARM UP ON MONDAY...TEMPERATURES
LOOK NEAR OR BELOW NORMAL FOR THE REST OF THE WEEK.
&&
.AVIATION...(FOR 06Z TAF ISSUANCE) EVENING SOUNDING AT GRB
SHOWING STRONG INVERSION...THIS LEADING TO STRATUS ONCE AGAIN
EXPANDING ACROSS STATE. RUC SEEMS TO HAVE BEST HANDLE ON THINGS SO
HAVE CONTINUED TO FOLLOW IT. IFR CIGS ARE EXPECTED...WITH LOCAL
LIFR OVER THE NORTH...INCLUDING RHI. MVFR VSBYS WITH WINDS
REMAINING UP OVERNIGHT...ALTHOUGH PATCHY IFR VSBYS WILL OCCUR OVER
THE REMAINING SNOW PACK IN NORTHERN WI. LOW LEVEL WIND SHEAR
POSSIBLE OVERNIGHT WITH SOUTHWEST WINDS AROUND 30 KNOTS AT 1000 FT
AGL AND SURFACE WINDS FROM THE SOUTH AT 5 TO 10 KNOTS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
KIECKBUSCH/MPC
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
309 AM CST THU NOV 24 2011
.TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM TO HIGH.
CURRENT LOW STRATUS DECK AND PATCHY FOG IS LOCATED ALONG AND EAST OF
A SUBTLE RIDGE AT SURFACE FROM TWIN CITIES DOWN INTO EASTERN
MISSOURI. WEST OF THIS RIDGE THE WINDS ARE MORE SOUTH...EAST OF THE
RIDGE THEY ARE SOUTHWEST. THEREFORE...A ZONE OF SUBSIDENCE EXITS IN
THIS WIND SEPARATION BAND...AND THIS IS WHERE THE STRATUS EDGE
IS...ROUGHLY. MODELS MOVE THIS RIDGE EAST TODAY. THE USUAL EROSION
WILL TAKE PLACE AS WELL. BASED ON 1000-950 MB RELATIVE HUMIDITY
VALUES SHOWN BY MODELS OVER MY COUNTY WARNING AREA...AREAS WEST OF
MADISON WILL BREAK UP BETWEEN 15Z AND 17Z. AREAS TOWARD MILWAUKEE
WILL NOT BREAK UP UNTIL 18-19Z. THEREAFTER...HAZY SUNSHINE WITH
SOUTHWEST WINDS IN THE 10 TO 15 MPH RANGE WITH GUSTS TO 20 MPH. MAX
TEMPS THIS AFTERNOON SHOULD MAKE IT INTO THE LOWER 50S...WHICH IS A
FEW POINTS HIGHER THAN YESTERDAY. BUT..I DON/T SEE THOSE MID-UPPER
50S DUE TO SLOW EROSION/MIXING OF STRATUS DECK AND LOW SUN ANGLE.
IF EVERYTHING I SAID IS WRONG...AND STRATUS BREAKS UP EARLIER THAN
EXPECTED...THEN WE/LL SEE UPPER 50S TO 60.
BUFKIT SOUNDINGS SHOW LOW-LEVEL INVERSION HANGING IN THIS AFTERNOON
INTO TONIGHT. THE 1000-950 RELATIVE HUMIDITY VALUES TONIGHT INCREASE
ONCE AGAIN TO 90 TO 95 PCT RANGE...SO EXPECT STRATUS DECK AND AREAS
OF FOG TO DEVELOP ONCE AGAIN TONIGHT. HOWEVER...SURFACE SOUTH TO
SOUTHWEST WINDS WILL REMAIN IN THE 8 TO 15 MPH RANGE TONIGHT PER
MODEL FORECASTS DUE TO DECENT SURFACE PRESSURE GRADIENT. JUST ABOVE
THE INVERSION...THE RUC AND NAM MODELS HAVE SOUTHWEST WINDS OF 47 TO
54 KNOTS AT AROUND 2000 FT AGL. GOOD THING INVERSION HANGS IN
THERE..OTHERWISE WE/D HAVE A WIND ADVISORY OR LOW-END HIGH WIND
EVENT ON OUR HANDS.
FRIDAY - CONFIDENCE...MEDIUM
1000-950 MILLIBAR RH PROG AND BUFKIT SOUNDINGS SUGGEST STRATUS
POTENTIAL BEST BETWEEN 12-15Z. SOUNDINGS ERODE THIS LOW LEVEL
MOISTURE AND THEN MID LEVEL MOISTURE INCREASES...AOA 15K FEET DURING
THE AFTERNOON. THE 850 THERMAL RIDGE IS REINFORCED BY THE CONTINUED
SOUTHWEST FLOW. STRONG SOUTHWEST UPPER FLOW HAS WEAKLY ANTICYCLONIC
LOOK TO IT. HOWEVER MODELS DO SHOW INCREASING VORTICITY...MOSTLY
SHEARED...INTO NORTHERN WI. THOUGH NAM/ECMWF DO SHOW SOME WEAK DCVA
INTO THE CWA IN THE AFTERNOON.
FRIDAY NIGHT THROUGH SATURDAY NIGHT - CONFIDENCE...MEDIUM
UPPER TROUGH APPROACHES AND DEEPENS WITH CLOSED LOW EVOLVING ACROSS
THE WESTERN GREAT LAKES SATURDAY NIGHT. 700 MILLIBAR OMEGA INCREASES
FRIDAY NIGHT...ESPECIALLY IN THE 6-12Z TIME FRAME. DIFFERENTIAL
CYCLONIC VORTICITY ADVECTION INCREASES FRIDAY NIGHT. BOTH THE ECMWF
AND GEMNH SUGGEST A DRY WEDGE IN THE FAR SOUTHEAST SO WILL HAVE
LOWER POPS THERE. SEVERAL SPOKES MAY ROTATE THROUGH AHEAD OF THE
LOW/UPPER TROUGH RIGHT THROUGH SATURDAY NIGHT. RIGHT REAR QUADRANT
UPPER JET DIVERGENCE IS ALSO NOTED FRIDAY NIGHT INTO SATURDAY
MORNING WITH JET CORE ON EASTERN SIDE OF ADVANCING TROUGH. PROGS
SUGGEST LATER FRIDAY NIGHT INTO SATURDAY MORNING AS THE BEST WINDOW
FOR WIDESPREAD RAIN POTENTIAL...SO WILL CONCENTRATE HIGHEST POPS IN
THAT TIME FRAME. COLD ADVECTION IS MUCH SLOWER TO ARRIVE ON THE ECMWF
WITH GFS AND NAM VERY QUICK TO ADVECT COLDER 850 TEMPS. WITH
LINGERING UPPER CYCLONIC FLOW SATURDAY NIGHT...ANY LIGHT PRECIP
COULD BECOME MIXY ESPECIALLY IN THE WESTERN CWA...THOUGH ECMWF
SUPPORTS LIQUID.
SUNDAY - CONFIDENCE...LOW
TIMING OF TROUGH AND ASSOCIATED LINGERING PRECIP A QUESTION. GFS/NAM
SUGGEST LINGERING LIGHT QPF WITH MUCH COLDER THERMAL
PROFILES...WHILE THE ECMWF IS MORE PROGRESSIVE...DRIER AND WARMER.
WILL LEAVE ALLBLEND POPS ALONE FOR NOW.
MONDAY - CONFIDENCE...LOW TO MEDIUM
WHILE THE ECMWF/GEM VARY ON POSITION OF UPPER LOW IN THE SE US...ALL
MODELS POINT TO A QUIET REGIME HERE IN SRN WI WITH MID LEVEL
RIDGING. WEAK WAVE IN MONDAY NIGHT TIME FRAME...WILL LEAN TOWARDS
DRY ALLBLEND POPS.
TUESDAY - CONFIDENCE...MEDIUM
THE STRONGER LOOKING GFS WAVE PASSES BY TO THE NORTH EARLY WHILE THE
ECMWF AND GEMNH HAVE MUCH WEAKER WAVE. IN ALL CASES PRECIP POTENTIAL
LOOKS LOW ENOUGH TO GO WITH THE DRY LOOK OF THE ALLBLEND.
WEDNESDAY - CONFIDENCE...LOW TO MEDIUM
GFS THE OUTLIER AT THIS POINT WITH A MORE VIGOROUS WAVE DRIVING
INTO THE AREA...WHILE THE ECMWF AND TRENDS IN GEMNH SUGGEST DRY
WITH VORT ACTION WELL NORTH AND BROAD WESTERLY ANTICYCLONIC FLOW.
&&
.AVIATION/12Z TAFS/...LOW STRATUS DECK AND FOG TRENDS PER FORECAST MODEL
OUTPUT SUGGESTS EROSION BY 15Z WEST OF MADISON...PROGRESSING TO
THE MILWAUKEE TO KENOSHA AREA BY 18 TO 19Z TODAY. SOUTHWEST WINDS
TO STAY UP IN THE 8 TO 15 KNOT RANGE WITH GUSTS TO 20 KNOTS...SO
DON/T EXPECT VSBYS TO GET BELOW 1 MILE..AND LOWEST CEILINGS WILL
BE 3 TO 4 HUNDRED FT. STRATUS DECK WILL SCATTER OUT FOR THE
AFTERNOON...WITH HAZY SUNSHINE AND VSBYS OF 5 TO 6 MILES UNDER
INVERSION. ABOVE THE INVERSION THE SOUTHWEST WINDS WILL BE
INCREASING TO 30 TO 40 KTS.
FOR TONIGHT...EXPECT THE LOW-LEVEL STRATUS DECK TO REFORM...IFR
CONDS WITH CIGS 5 TO 9 HUNDRED FT AGL. VSBYS SHOULD BE IN THE 2 TO 5
MILE RANGE UNDER INVERSION. FORECAST MODELS INCREASE SOUTHWEST WINDS
JUST ABOVE THE INVERSION TO 48 TO 54 KNOTS..ABOUT 2 THSD FT AGL.
WILL KEEP LOW-LEVEL WIND SHEAR TERM IN THE TAFS FOR TONIGHT. SURFACE
WINDS WILL REMAIN IN THE 10 TO 15 KNOT RANGE WITH SOME HIGHER GUSTS
TO AROUND 20 KNOTS.
&&
.MARINE...THE PRESSURE GRADIENT WILL TIGHTEN TODAY...AND REMAIN TIGHT
THROUGH FRIDAY. GUSTS TO 20 TO 25 KNOTS ON ORDER...SO HAVE ISSUED
A SMALL CRAFT ADVISORY THROUGH FRIDAY...ENDING FRIDAY EVENING AS
LOW PRESSURE MOVES ACROSS NORTHERN WISCONSIN. SOME PATCHY FOG
TODAY AND TONIGHT WITH MOIST LOW-LEVEL AIR UNDER INVERSION WHICH
NEVER REALLY BREAKS UP OVER THE WATERS.
MORE GUSTY WINDS AFTER THE COLD FRONTAL PASSAGE SATURDAY INTO
SUNDAY. GUSTY WEST TO NORTHWEST WINDS OF 30 TO 35 KNOTS ARE
POSSIBLE. THE HIGHEST WAVES AGAIN WOULD BE TOWARD THE OPEN WATERS
WITH THE OFFSHORE FLOW. A SMALL CRAFT ADVISORY OR GALE WATCH/WARNING
MAY BE NEEDED FOR THIS PERIOD.
BRISK WINDS AND HIGH WAVES ARE POSSIBLE AGAIN NEXT MONDAY AND
TUESDAY...AHEAD OF AND BEHIND A PASSING COLD FRONT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM CST FRIDAY FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...KAPELA
FRIDAY THROUGH WEDNESDAY...COLLAR
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1052 PM CST WED NOV 23 2011
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...FORECASTING CLOUD COVER IS THE BIGGEST CHALLENGE OF
TONIGHT AND TOMORROWS FORECAST...AS IT HAS BEEN FOR THE LAST FEW
DAYS. IT IS USUALLY WISE TO KEEP CLOUDS AROUND IN NOVEMBER AND
DECEMBER AND WILL KEEP MORE CLOUDS IN THE FORECAST THAN THE
GUIDANCE WOULD INDICATE. THE RUC HAD THE BEST FORECAST OF THE
CLOUD COVER THIS AFTERNOON WITH CLEARING OCCURRING IN THE DOWNSLOPE
AREA OF NORTHEAST WISCONSIN. IT WOULD KEEP THE CURRENT CLOUDS IN
THE WESTERN PART OF THE FORECAST AREA FOR MOST OF THE NIGHT WITH
CLOUDS REFORMING GENERALLY NORTH OF GREEN BAY IN THE EAST.
DIFFICULT TO SAY FOR SURE. WE HAVE TRIED JUST ABOUT EVERY MODEL
FIELD (1000MB TO 925MB, 925MB, 925 TO 950MB RELATIVE HUMIDITY,
MOISTURE TRANSPORT VECTORS, AND HRR CEILING HEIGHTS) BUT NONE
DEPICT THE CURRENT CLOUDS THAT WELL. LOWS TONIGHT SHOULD BE ABOVE
NORMAL ONCE AGAIN DUE TO MILD BOUNDARY LAYER TEMPERATURES, A
STEADY BREEZE AND CLOUDS. THE COOLEST TEMPERATURES SHOULD BE IN
VALLEYS WITH CLEAR SKIES AND IN AREAS WITH SNOW ON THE GROUND.
THANKSGIVING MAY NOT BE QUITE AS MILD AS IT LOOKED LIKE A FEW
DAYS AGO AS THERE IS A POSSIBILITY THAT THE DAY COULD START OUT
WITH CLOUDS LIKE MOST OF THE LAST FEW DAYS. 925MB TEMPERATURES ARE
VERY MILD THOUGH, AND EVEN WITH CLOUDS IT WILL BE 10 TO 15 DEGREES
ABOVE NORMAL AND THERE SHOULD AT LEAST BE SOME SUNSHINE BY
AFTERNOON IN MOST PLACES.
.LONG TERM...THURSDAY NIGHT TO WEDNESDAY.
SOUTHERLY FLOW AHEAD OF A WEAK COLD FRONT EXPECTED THURSDAY
EVENING. GRADIENT EXPECTED TO SLACKEN DURING THE NIGHT...ESPECIALLY
ACROSS THE NORTH. DEPENDING ON HOW MUCH SNOW PACK IS LEFT...ENOUGH
EVIDENCE TO ADD FOG AFTER MIDNIGHT OVER THE FAR NORTH. MODELS TODAY
ARE SHOWING LOW LEVEL MOISTURE TRAPPED BELOW AN INVERSION LATER
THURSDAY NIGHT INTO FRIDAY. QUESTION IS HOW QUICK THIS LAYER WILL
SATURATE. DO THINK BEST SATURATION WILL OCCUR ACROSS THE NORTH. CONFIDENCE
IS NOT THAT GREAT ACROSS THE SOUTH DUE TO DIFFERING NUMERICAL
GUIDANCE VALUES FOR CLOUD HEIGHT. WITH EXPECTED LOW CLOUDS TO
DEVELOP ACROSS THE NORTH AND WEAK UPWARD VERTICAL MOTIONS...THOUGHTS
TURNED TO THE POTENTIAL FOR DRIZZLE LATE THURSDAY NIGHT INTO FRIDAY.
DO THINK MOISTURE WILL BE TOO SHALLOW THURSDAY NIGHT INTO FRIDAY MORNING...
BUT CLOUD LAYER MAY BE DEEP ENOUGH TO SUPPORT DRIZZLE FRIDAY AFTERNOON.
DID NOT ADD DRIZZLE TO THE FORECAST ACROSS THE NORTH ON FRIDAY AND
WILL PASS ON MY CONCERNS TO MIDNIGHT SHIFT.
FOR FRIDAY NIGHT...MOIST SOUTHERLY FLOW EXPECTED ACROSS THE AREA. THINK
PRECIPITATION WILL START OUT AS DRIZZLE WITH A MORE STEADIER RAIN LATE
FRIDAY NIGHT INTO SATURDAY AS FRONT APPROACHES. PRECIPITATION WILL
CONTINUE INTO SATURDAY. MORE QUESTIONS APPEAR ON SATURDAY AS SEVERAL
MODELS SHOW A DRY SLOT MOVING ACROSS THE REGION SATURDAY AFTERNOON
INTO SATURDAY NIGHT. DESPITE A FEW MODELS DRYING US OUT FOR AWHILE...
WILL CONTINUE A CHANCE OF RAIN SATURDAY AFTERNOON AND RAIN OR SNOW
SATURDAY NIGHT. MANY QUESTIONS LINGER SATURDAY NIGHT ON HOW FAST THE
COLD AIR WILL ARRIVE. LATER SHIFTS WILL PROBABLY NEED TO ALTER TIMING
THE CHANGEOVER TO ALL SNOW ACROSS SOME PORTION OF THE FORECAST AREA.
OTHERWISE...ANOTHER SYSTEM WILL MOVE ACROSS THE AREA MONDAY NIGHT
AND TUESDAY AND WILL BRING ANOTHER SMALL CHANCE FOR RAIN OR SNOW
TO THE AREA.
&&
.AVIATION...
EVENING SOUNDING AT GRB SHOWING STRONG INVERSION...THIS
LEADING TO STRATUS ONCE AGAIN EXPANDING ACROSS STATE. RUC SEEMS
TO HAVE BEST HANDLE ON THINGS SO HAVE CONTINUED TO FOLLOWED...CLEARING
EAST WILL BE TAKEN OVER BY STRATUS BETWEEN 6Z AND 9Z. CIG MVFR
CIGS WILL DROP TO IFR...LOCAL LIFR OVER NORTH...RHI. MVFR VISBYS
WITH WINDS REMAINING UP OVERNIGHT. LOW LEVEL WIND SHEAR POSSIBLE
THROUGH 9Z WITH SOUTHWEST WINDS AROUND 30 KNOTS AT 1000 FT AGL AND
SURFACE WINDS FROM THE SOUTH AT 5 TO 10 KNOTS.
TE
&&
.MARINE...HAZARDOUS CONDITIONS WITH GALE FORCE ARE POSSIBLE OVER
THE UPCOMING WEEKEND. MODEL DIFFERENCES IN STRENGTH AND TIMING OF
THIS SYSTEM THIS WEEKEND ARE MITIGATING FACTORS IN INTRODUCING
GALES IN THE HAZARDOUS WEATHER OUTLOOK. IT APPEARS THAT THE
STRONGEST WINDS WILL BE SATURDAY NIGHT INTO SUNDAY...BUT COULD
START SATURDAY AFTERNOON IF THE QUICKER MODEL SOLUTION IS CORRECT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1016 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO OUR REGION THIS THANKSGIVING
THURSDAY AND DOMINATE OUR WEATHER INTO SUNDAY. A COLD FRONT...
APPROACHING FROM THE WEST...WILL MOVE SLOWLY ACROSS OUR REGION
SUNDAY NIGHT INTO MONDAY. LOW PRESSURE MAY DEVELOP ON THE FRONT
ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY NORTHWARD MONDAY
NIGHT INTO TUESDAY NIGHT. MORE LOW PRESSURE IS POSSIBLE DURING
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD AIR ADVECTION IS ENDING. HOWEVER TEMPERATURES WITH THE
PREVIOUS FORECAST ARE ON TRACK TODAY WITH SLIGHT ALTERATIONS
BASED ON 14Z METAR OBS. RAISED VISIBILITY A BIT ON THIS UPDATE ALSO
BASED OFF OF 14Z OBS. PREVIOUS FORECASTER THINKING BELOW STILL
LOOKS GOOD SO FEW CHANGES MADE OVERALL ATTM. A VERY NICE
THANKSGIVING DAY IS AHEAD OF US!
CONVECTIVE TEMPERATURES ARE OUT OF REACH TODAY...AND OTHER THAN
SOME HIGH CLOUDINESS THIS MORNING...SKIES SHOULD BE SUNNY. THE
BEST PART OF THE SURFACE PRESSURE GRADIENT IS OVER THE FORECAST
AREA NOW...AND SOME GUSTINESS LINGERS. THE GUSTINESS TO THE WIND
SHOULD DROP BACK EARLY THIS MORNING AS THE LAST OF THE COLD AIR
ADVECTION ENDS.
IT IS POSSIBLE THERE COULD BE SOME GUSTINESS TODAY...BUT FOR THE
MOST PART WINDS SHOULD NOT BE AN ISSUE TODAY. 850 MB TEMPERATURES
SUPPORT HIGHS IN THE MID 50S TODAY...WHICH IS CLOSE TO THE MOS
BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
BUILDING MID LEVEL RIDGING SHOULD KEEP ANY HIGH AND MID LEVEL CLOUDS
NORTH OF THE AREA TONIGHT...AND SKIES SHOULD BE CLEAR. AS THE HIGH
REACHES NORTH CAROLINA TONIGHT...THE GRADIENT WILL BACK OFF.
HOWEVER...WINDS MAY NOT BECOME COMPLETELY CALM OUTSIDE OF PROTECTED
AREAS...AS THE GRADIENT WOULD SUPPORT WEST WINDS LESS THAN 10 MPH.
THE ABOVE SCENARIO WOULD SUPPORTS LOWS NEAR THE MOS BLEND IN THE
URBAN AREAS AND PLACES WITH EXPOSURE. FOR PROTECTED AREAS (INCLUDING
THE PINE BARRENS IN NEW JERSEY)...LOWS WERE DROPPED A FEW DEGREES
FROM THE MOS MEAN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A QUIESCENT PERIOD OF WEATHER IS SHAPING UP FOR THE NORTHERN MID
ATLANTIC AREA FRIDAY INTO SUNDAY. THE MODELS HAVE LATCHED ONTO A
COLD FRONT WHICH LOOKS LIKE IT WILL AFFECT OUR AREA MAINLY SUNDAY
NIGHT INTO MONDAY. THEN...MODEL PERFORMANCE HAS SEEMINGLY
DETERIORATED OVER THE PAST 24 TO 48 HOURS, WITH RUN-TO-RUN AND
INTERMODEL INCONSISTENCY AND CHANGEABILITY. WITH NO CLEAR
SIGNALS...IT WAS DECIDED TO JUST USE A BROAD BRUSH OF CHANCE
PROBABILITIES FOR SHOWERS THROUGH THE MONDAY THROUGH WEDNESDAY
PERIOD, WITH A MODERATE TO HIGH AMOUNT OF CLOUDINESS. THE GFS EVEN
PAINTS SOME TYPE OF RAIN/SNOW EVENT WEDNESDAY NIGHT INTO THURSDAY.
LATER MODEL ITERATIONS WILL BE NEEDED TO GAIN MORE CLARITY ON THIS
PERIOD.
SO...HPC TEMPERATURES WERE USED AS A STARTING POINT FOR HIGHS AND
LOWS, WITH SOME MODIFICATIONS FOR LOCAL EFFECTS AND CLIMATOLOGY. A
GENERAL COOLING TREND SHOULD OCCUR THROUGH THE LONG TERM PERIOD...
WITH HIGHS IN THE MID 50S AND LOWER 60S OVER THE WEEKEND, DROPPING
TO THE 40S TO NEAR 50 BY WEDNESDAY.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL CONTINUE TO PROVIDE US WITH FINE VFR
FLYING CONDITIONS FRIDAY INTO...OR PERHAPS THROUGH MOST OF...SUNDAY.
A COLD FRONT MOVING IN FROM THE WEST SUNDAY NIGHT WILL MOVE EASTWARD
THROUGH OUR AREA. HOWEVER, A SUCCESSION OF LOWS COULD AFFECT OUR
REGION AND PERHAPS BRING LOWER CONDITIONS AT TIMES INTO THE EARLY OR
EVEN MIDDLE PORTION OF NEXT WEEK. MODEL GUIDANCE HAS BEEN CHANGING
AND INCONSISTENT...SO LITTLE IN THE WAY OF CONFIDENCE CAN BE SHOWN
UNTIL THE MODELS START TO OFFER BETTER AGREEMENT AND RUN-TO-RUN
CONSISTENCY. LOWER CEILINGS AND/OR VISIBILITIES IN SHOWERS/RAIN AND
FOG MAY OCCUR THROUGH MUCH OF THE SUNDAY NIGHT THROUGH WEDNESDAY
TIME PERIOD, THOUGH.
&&
.MARINE...
WINDS AND SEAS CONTINUE TO DECREASE ON THE WATERS THIS MORNING.
THE SCA FLAG FOR THE DELAWARE BAY AND THE NORTHERN COASTAL WATERS
HAVE BEEN TAKEN DOWN. SEAS REMAIN UP ACROSS THE SOUTHERN COASTAL
WATERS...SO THE FLAG WILL CONTINUE THERE INTO THE MID-AFTERNOON. A
FEW GUSTS UP TO 25 KTS STILL MAY OCCUR ON THE WATERS THIS
AFTERNOON...BUT THE TREND CONTINUES DOWNWARD AS HIGH PRESSURE
BUILDS IN. SUB SCA CONDITIONS EXPECTED TONIGHT INTO FRIDAY AND
WINDS WILL BACK AROUND TO W THEN SW.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR MARINE
AREA FRIDAY THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST,
A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY. THE PRESSURE
GRADIENT WILL TIGHTEN BETWEEN THESE TWO SYSTEMS...AND THIS WILL MEAN
A GOOD CHANCE OF SHOWERS AS WELL AS INCREASING SOUTH TO SOUTHEAST
WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY. A SERIES OF LOW
PRESSURE SYSTEMS COULD AFFECT OUR AREA THROUGH THE EARLY AND MIDDLE
PORTIONS OF NEXT WEEK...BUT MODEL GUIDANCE HAS BECOME TOO CHANGEABLE
AND INCONSISTENT TO OFFER ANY KIND OF SPECIFICS. ADVISORY CONDITIONS
ARE LIKELY AT SOME POINT...AND EVEN GALE CONDITIONS MAY OCCUR FOR A
TIME...IN THE SUNDAY NIGHT TO MID WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
THE CFW FOR THE OCEAN AREAS HAS BEEN CANCELLED WITH THE HIGH TIDE
HAVING PASSED. MINOR TIDAL FLOODING LEVELS WERE REACHED ALONG THE
SHORE AREAS.
TIDE DEPARTURES ON THE UPPER DELAWARE BAY AND TIDAL PORTION OF
THE DELAWARE HAVE INCREASED STEADILY THIS MORNING. THE FACT THAT
WE WOULD ONLY NEED ABOUT ONE-HALF TO THREE-QUARTERS OF A FOOT OF
DEPARTURE FROM PREDICTED (WE ARE JUST ABOUT THERE NOW) SUGGESTS
THAT MINOR TIDAL FLOODING WILL OCCUR THERE AS WELL. BASED ON THE
ABOVE...AND THE RATE OF INCREASE OF DEPARTURES...A COASTAL FLOOD
ADVISORY HAS BEEN ISSUED FOR THE UPPER DELAWARE BAY AND TIDAL
SECTION OF THE DELAWARE RIVER.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
PAZ070-071.
NJ...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ016>019-021.
DE...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ001-002.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
ANZ452>455.
&&
$$
SYNOPSIS...
NEAR TERM...GAINES/HAYES
SHORT TERM...HAYES
LONG TERM...
AVIATION...HAYES
MARINE...HAYES
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
925 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO OUR REGION THIS THANKSGIVING
THURSDAY AND DOMINATE OUR WEATHER INTO SUNDAY. A COLD FRONT...
APPROACHING FROM THE WEST...WILL MOVE SLOWLY ACROSS OUR REGION
SUNDAY NIGHT INTO MONDAY. LOW PRESSURE MAY DEVELOP ON THE FRONT
ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY NORTHWARD MONDAY
NIGHT INTO TUESDAY NIGHT. MORE LOW PRESSURE IS POSSIBLE DURING
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD AIR ADVECTION IS ENDING. HOWEVER TEMPERATURES WITH THE
PREVIOUS FORECAST ARE ON TRACK TODAY WITH SLIGHT ALTERATIONS
BASED ON 14Z METAR OBS. RAISED VISIBILITY A BIT ON THIS UPDATE ALSO
BASED OFF OF 14Z OBS. PREVIOUS FORECASTER THINKING BELOW STILL
LOOKS GOOD SO FEW CHANGES MADE OVERALL ATTM. A VERY NICE
THANKSGIVING DAY IS AHEAD OF US!
CONVECTIVE TEMPERATURES ARE OUT OF REACH TODAY...AND OTHER THAN
SOME HIGH CLOUDINESS THIS MORNING...SKIES SHOULD BE SUNNY. THE
BEST PART OF THE SURFACE PRESSURE GRADIENT IS OVER THE FORECAST
AREA NOW...AND SOME GUSTINESS LINGERS. THE GUSTINESS TO THE WIND
SHOULD DROP BACK EARLY THIS MORNING AS THE LAST OF THE COLD AIR
ADVECTION ENDS.
IT IS POSSIBLE THERE COULD BE SOME GUSTINESS TODAY...BUT FOR THE
MOST PART WINDS SHOULD NOT BE AN ISSUE TODAY. 850 MB TEMPERATURES
SUPPORT HIGHS IN THE MID 50S TODAY...WHICH IS CLOSE TO THE MOS
BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
BUILDING MID LEVEL RIDGING SHOULD KEEP ANY HIGH AND MID LEVEL CLOUDS
NORTH OF THE AREA TONIGHT...AND SKIES SHOULD BE CLEAR. AS THE HIGH
REACHES NORTH CAROLINA TONIGHT...THE GRADIENT WILL BACK OFF.
HOWEVER...WINDS MAY NOT BECOME COMPLETELY CALM OUTSIDE OF PROTECTED
AREAS...AS THE GRADIENT WOULD SUPPORT WEST WINDS LESS THAN 10 MPH.
THE ABOVE SCENARIO WOULD SUPPORTS LOWS NEAR THE MOS BLEND IN THE
URBAN AREAS AND PLACES WITH EXPOSURE. FOR PROTECTED AREAS (INCLUDING
THE PINE BARRENS IN NEW JERSEY)...LOWS WERE DROPPED A FEW DEGREES
FROM THE MOS MEAN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A QUIESCENT PERIOD OF WEATHER IS SHAPING UP FOR THE NORTHERN MID
ATLANTIC AREA FRIDAY INTO SUNDAY. THE MODELS HAVE LATCHED ONTO A
COLD FRONT WHICH LOOKS LIKE IT WILL AFFECT OUR AREA MAINLY SUNDAY
NIGHT INTO MONDAY. THEN...MODEL PERFORMANCE HAS SEEMINGLY
DETERIORATED OVER THE PAST 24 TO 48 HOURS, WITH RUN-TO-RUN AND
INTERMODEL INCONSISTENCY AND CHANGEABILITY. WITH NO CLEAR
SIGNALS...IT WAS DECIDED TO JUST USE A BROAD BRUSH OF CHANCE
PROBABILITIES FOR SHOWERS THROUGH THE MONDAY THROUGH WEDNESDAY
PERIOD, WITH A MODERATE TO HIGH AMOUNT OF CLOUDINESS. THE GFS EVEN
PAINTS SOME TYPE OF RAIN/SNOW EVENT WEDNESDAY NIGHT INTO THURSDAY.
LATER MODEL ITERATIONS WILL BE NEEDED TO GAIN MORE CLARITY ON THIS
PERIOD.
SO...HPC TEMPERATURES WERE USED AS A STARTING POINT FOR HIGHS AND
LOWS, WITH SOME MODIFICATIONS FOR LOCAL EFFECTS AND CLIMATOLOGY. A
GENERAL COOLING TREND SHOULD OCCUR THROUGH THE LONG TERM PERIOD...
WITH HIGHS IN THE MID 50S AND LOWER 60S OVER THE WEEKEND, DROPPING
TO THE 40S TO NEAR 50 BY WEDNESDAY.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL CONTINUE TO PROVIDE US WITH FINE VFR
FLYING CONDITIONS FRIDAY INTO...OR PERHAPS THROUGH MOST OF...SUNDAY.
A COLD FRONT MOVING IN FROM THE WEST SUNDAY NIGHT WILL MOVE EASTWARD
THROUGH OUR AREA. HOWEVER, A SUCCESSION OF LOWS COULD AFFECT OUR
REGION AND PERHAPS BRING LOWER CONDITIONS AT TIMES INTO THE EARLY OR
EVEN MIDDLE PORTION OF NEXT WEEK. MODEL GUIDANCE HAS BEEN CHANGING
AND INCONSISTENT...SO LITTLE IN THE WAY OF CONFIDENCE CAN BE SHOWN
UNTIL THE MODELS START TO OFFER BETTER AGREEMENT AND RUN-TO-RUN
CONSISTENCY. LOWER CEILINGS AND/OR VISIBILITIES IN SHOWERS/RAIN AND
FOG MAY OCCUR THROUGH MUCH OF THE SUNDAY NIGHT THROUGH WEDNESDAY
TIME PERIOD, THOUGH.
&&
.MARINE...
THE GRADIENT REMAINS IN PLACE MOST OF THE DAY...AND AT A GLANCE
DOES NOT APPEAR TO SUPPORT SMALL CRAFT WINDS ANYWHERE AFTER ABOUT
1500 UTC. THEREFORE...THE SMALL CRAFT ADVISORY THAT REPLACES THE
GALE WARNING WILL BE RUN UNTIL ABOUT 1500 UTC ON THE DELAWARE BAY
(AND IT MAY NOT EVEN BE NEEDED THAT LONG).
OVER THE OCEAN WATERS...SEAS ARE STILL RUNNING 5 TO 9 FEET...WITH
THE HIGHEST SEAS ACROSS THE SOUTHERN WATERS. WHILE WINDS SHOULD DROP
BELOW SMALL CRAFT LEVELS IN GUSTS BY 1500 UTC...THE SEAS ACROSS
THE SOUTHERN WATERS MAY TAKE LONGER TO SORT THEMSELVES OUT. BASED
ON THE ABOVE...THE SMALL CRAFT ADVISORY WILL BE RUN THROUGH ABOUT
1500 UTC ACROSS THE NORTHERN OCEAN WATERS...AND ABOUT 1800 UTC
ACROSS THE SOUTHERN OCEAN WATERS.
AFTER THIS...THE GRADIENT LOOKS TO SUPPORT WINDS AROUND 15 KNOTS ON
THE OCEAN FOR THE REST OF TODAY INTO TONIGHT. WINDS ACROSS THE
DELAWARE BAY WILL BE SLIGHTLY LOWER...BUT PROBABLY DO NOT DROP BELOW
10 KNOTS...AS THE GRADIENT LOOKS TO SUPPORT WINDS OF THESE SPEEDS.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR MARINE
AREA FRIDAY THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST,
A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY. THE PRESSURE
GRADIENT WILL TIGHTEN BETWEEN THESE TWO SYSTEMS...AND THIS WILL MEAN
A GOOD CHANCE OF SHOWERS AS WELL AS INCREASING SOUTH TO SOUTHEAST
WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY. A SERIES OF LOW
PRESSURE SYSTEMS COULD AFFECT OUR AREA THROUGH THE EARLY AND MIDDLE
PORTIONS OF NEXT WEEK...BUT MODEL GUIDANCE HAS BECOME TOO CHANGEABLE
AND INCONSISTENT TO OFFER ANY KIND OF SPECIFICS. ADVISORY CONDITIONS
ARE LIKELY AT SOME POINT...AND EVEN GALE CONDITIONS MAY OCCUR FOR A
TIME...IN THE SUNDAY NIGHT TO MID WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
THE CFW FOR THE OCEAN AREAS HAS BEEN CANCELLED WITH THE HIGH TIDE
HAVING PASSED. MINOR TIDAL FLOODING LEVELS WERE REACHED ALONG THE
SHORE AREAS.
TIDE DEPARTURES ON THE UPPER DELAWARE BAY AND TIDAL PORTION OF
THE DELAWARE HAVE INCREASED STEADILY THIS MORNING. THE FACT THAT
WE WOULD ONLY NEED ABOUT ONE-HALF TO THREE-QUARTERS OF A FOOT OF
DEPARTURE FROM PREDICTED (WE ARE JUST ABOUT THERE NOW) SUGGESTS
THAT MINOR TIDAL FLOODING WILL OCCUR THERE AS WELL. BASED ON THE
ABOVE...AND THE RATE OF INCREASE OF DEPARTURES...A COASTAL FLOOD
ADVISORY HAS BEEN ISSUED FOR THE UPPER DELAWARE BAY AND TIDAL
SECTION OF THE DELAWARE RIVER.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
PAZ070-071.
NJ...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ016>019-021.
DE...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ001-002.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR ANZ450-
451.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ430-
431.
&&
$$
SYNOPSIS...
NEAR TERM...GAINES/HAYES
SHORT TERM...HAYES
LONG TERM...
AVIATION...HAYES
MARINE...HAYES
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
909 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO OUR REGION THIS THANKSGIVING
THURSDAY AND DOMINATE OUR WEATHER INTO SUNDAY. A COLD FRONT...
APPROACHING FROM THE WEST...WILL MOVE SLOWLY ACROSS OUR REGION
SUNDAY NIGHT INTO MONDAY. LOW PRESSURE MAY DEVELOP ON THE FRONT
ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY NORTHWARD MONDAY
NIGHT INTO TUESDAY NIGHT. MORE LOW PRESSURE IS POSSIBLE DURING
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD AIR ADVECTION IS ENDING...AND THE MOISTURE TRAPPED UNDER
THE INVERSION IS MIXING OUT. THE MOISTURE MAY BE TOUGHER TO SCOUR
OUT OF THE HIGHER TERRAIN...AND THIS MAY HAVE TO BE ACCOUNTED FOR
IN THE MORNING FORECAST.
CONVECTIVE TEMPERATURES ARE OUT OF REACH TODAY...AND OTHER THAN
SOME HIGH CLOUDINESS THIS MORNING...SKIES SHOULD BE SUNNY. THE
BEST PART OF THE SURFACE PRESSURE GRADIENT IS OVER THE FORECAST
AREA NOW...AND SOME GUSTINESS LINGERS. THE GUSTINESS TO THE WIND
SHOULD DROP BACK EARLY THIS MORNING AS THE LAST OF THE COLD AIR
ADVECTION ENDS.
IT IS POSSIBLE THERE COULD BE SOME GUSTINESS TODAY...BUT FOR THE
MOST PART WINDS SHOULD NOT BE AN ISSUE TODAY. 850 MB TEMPERATURES
SUPPORT HIGHS IN THE MID 50S TODAY...WHICH IS CLOSE TO THE MOS
BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
BUILDING MID LEVEL RIDGING SHOULD KEEP ANY HIGH AND MID LEVEL CLOUDS
NORTH OF THE AREA TONIGHT...AND SKIES SHOULD BE CLEAR. AS THE HIGH
REACHES NORTH CAROLINA TONIGHT...THE GRADIENT WILL BACK OFF.
HOWEVER...WINDS MAY NOT BECOME COMPLETELY CALM OUTSIDE OF PROTECTED
AREAS...AS THE GRADIENT WOULD SUPPORT WEST WINDS LESS THAN 10 MPH.
THE ABOVE SCENARIO WOULD SUPPORTS LOWS NEAR THE MOS BLEND IN THE
URBAN AREAS AND PLACES WITH EXPOSURE. FOR PROTECTED AREAS (INCLUDING
THE PINE BARRENS IN NEW JERSEY)...LOWS WERE DROPPED A FEW DEGREES
FROM THE MOS MEAN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A QUIESCENT PERIOD OF WEATHER IS SHAPING UP FOR THE NORTHERN MID
ATLANTIC AREA FRIDAY INTO SUNDAY. THE MODELS HAVE LATCHED ONTO A
COLD FRONT WHICH LOOKS LIKE IT WILL AFFECT OUR AREA MAINLY SUNDAY
NIGHT INTO MONDAY. THEN...MODEL PERFORMANCE HAS SEEMINGLY
DETERIORATED OVER THE PAST 24 TO 48 HOURS, WITH RUN-TO-RUN AND
INTERMODEL INCONSISTENCY AND CHANGEABILITY. WITH NO CLEAR
SIGNALS...IT WAS DECIDED TO JUST USE A BROAD BRUSH OF CHANCE
PROBABILITIES FOR SHOWERS THROUGH THE MONDAY THROUGH WEDNESDAY
PERIOD, WITH A MODERATE TO HIGH AMOUNT OF CLOUDINESS. THE GFS EVEN
PAINTS SOME TYPE OF RAIN/SNOW EVENT WEDNESDAY NIGHT INTO THURSDAY.
LATER MODEL ITERATIONS WILL BE NEEDED TO GAIN MORE CLARITY ON THIS
PERIOD.
SO...HPC TEMPERATURES WERE USED AS A STARTING POINT FOR HIGHS AND
LOWS, WITH SOME MODIFICATIONS FOR LOCAL EFFECTS AND CLIMATOLOGY. A
GENERAL COOLING TREND SHOULD OCCUR THROUGH THE LONG TERM PERIOD...
WITH HIGHS IN THE MID 50S AND LOWER 60S OVER THE WEEKEND, DROPPING
TO THE 40S TO NEAR 50 BY WEDNESDAY.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL CONTINUE TO PROVIDE US WITH FINE VFR
FLYING CONDITIONS FRIDAY INTO...OR PERHAPS THROUGH MOST OF...SUNDAY.
A COLD FRONT MOVING IN FROM THE WEST SUNDAY NIGHT WILL MOVE EASTWARD
THROUGH OUR AREA. HOWEVER, A SUCCESSION OF LOWS COULD AFFECT OUR
REGION AND PERHAPS BRING LOWER CONDITIONS AT TIMES INTO THE EARLY OR
EVEN MIDDLE PORTION OF NEXT WEEK. MODEL GUIDANCE HAS BEEN CHANGING
AND INCONSISTENT...SO LITTLE IN THE WAY OF CONFIDENCE CAN BE SHOWN
UNTIL THE MODELS START TO OFFER BETTER AGREEMENT AND RUN-TO-RUN
CONSISTENCY. LOWER CEILINGS AND/OR VISIBILITIES IN SHOWERS/RAIN AND
FOG MAY OCCUR THROUGH MUCH OF THE SUNDAY NIGHT THROUGH WEDNESDAY
TIME PERIOD, THOUGH.
&&
.MARINE...
THE GRADIENT REMAINS IN PLACE MOST OF THE DAY...AND AT A GLANCE
DOES NOT APPEAR TO SUPPORT SMALL CRAFT WINDS ANYWHERE AFTER ABOUT
1500 UTC. THEREFORE...THE SMALL CRAFT ADVISORY THAT REPLACES THE
GALE WARNING WILL BE RUN UNTIL ABOUT 1500 UTC ON THE DELAWARE BAY
(AND IT MAY NOT EVEN BE NEEDED THAT LONG).
OVER THE OCEAN WATERS...SEAS ARE STILL RUNNING 5 TO 9 FEET...WITH
THE HIGHEST SEAS ACROSS THE SOUTHERN WATERS. WHILE WINDS SHOULD DROP
BELOW SMALL CRAFT LEVELS IN GUSTS BY 1500 UTC...THE SEAS ACROSS THE
SOUTHERN WATERS MAY TAKE LONGER TO SORT THEMSELVES OUT. BASED ON THE
ABOVE...THE SMALL CRAFT ADVISORY WILL BE RUN THROUGH ABOUT 1500 UTC
ACROSS THE NORTHERN OCEAN WATERS...AND ABOUT 1800 UTC ACROSS THE
SOUTHERN OCEAN WATERS.
AFTER THIS...THE GRADIENT LOOKS TO SUPPORT WINDS AROUND 15 KNOTS ON
THE OCEAN FOR THE REST OF TODAY INTO TONIGHT. WINDS ACROSS THE
DELAWARE BAY WILL BE SLIGHTLY LOWER...BUT PROBABLY DO NOT DROP BELOW
10 KNOTS...AS THE GRADIENT LOOKS TO SUPPORT WINDS OF THESE SPEEDS.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR MARINE
AREA FRIDAY THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST,
A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY. THE PRESSURE
GRADIENT WILL TIGHTEN BETWEEN THESE TWO SYSTEMS...AND THIS WILL MEAN
A GOOD CHANCE OF SHOWERS AS WELL AS INCREASING SOUTH TO SOUTHEAST
WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY. A SERIES OF LOW
PRESSURE SYSTEMS COULD AFFECT OUR AREA THROUGH THE EARLY AND MIDDLE
PORTIONS OF NEXT WEEK...BUT MODEL GUIDANCE HAS BECOME TOO CHANGEABLE
AND INCONSISTENT TO OFFER ANY KIND OF SPECIFICS. ADVISORY CONDITIONS
ARE LIKELY AT SOME POINT...AND EVEN GALE CONDITIONS MAY OCCUR FOR A
TIME...IN THE SUNDAY NIGHT TO MID WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
THE CFW FOR THE OCEAN AREAS HAS BEEN CANCELLED WITH THE HIGH TIDE
HAVING PASSED. MINOR TIDAL FLOODING LEVELS WERE REACHED ALONG THE
SHORE AREAS.
TIDE DEPARTURES ON THE UPPER DELAWARE BAY AND TIDAL PORTION OF
THE DELAWARE HAVE INCREASED STEADILY THIS MORNING. THE FACT THAT
WE WOULD ONLY NEED ABOUT ONE-HALF TO THREE-QUARTERS OF A FOOT OF
DEPARTURE FROM PREDICTED (WE ARE JUST ABOUT THERE NOW) SUGGESTS
THAT MINOR TIDAL FLOODING WILL OCCUR THERE AS WELL. BASED ON THE
ABOVE...AND THE RATE OF INCREASE OF DEPARTURES...A COASTAL FLOOD
ADVISORY HAS BEEN ISSUED FOR THE UPPER DELAWARE BAY AND TIDAL
SECTION OF THE DELAWARE RIVER.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
PAZ070-071.
NJ...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ016>019-021.
DE...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ001-002.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR ANZ450-
451.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ430-
431.
&&
$$
SYNOPSIS...
NEAR TERM...HAYES
SHORT TERM...HAYES
LONG TERM...
AVIATION...HAYES
MARINE...HAYES
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
630 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO OUR REGION THIS THANKSGIVING
THURSDAY AND DOMINATE OUR WEATHER INTO SUNDAY. A COLD FRONT...
APPROACHING FROM THE WEST...WILL MOVE SLOWLY ACROSS OUR REGION
SUNDAY NIGHT INTO MONDAY. LOW PRESSURE MAY DEVELOP ON THE FRONT
ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY NORTHWARD MONDAY
NIGHT INTO TUESDAY NIGHT. MORE LOW PRESSURE IS POSSIBLE DURING
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LOWER CLOUD DECK CONTINUES TO SHRINK AWAY EARLY THIS
MORNING...WITH THE LAST VESTIGES OVER THE SOUTHERN POCONOS AND
SOUTHERN NEW JERSEY AND DELAWARE. THE COLD AIR ADVECTION IS
ENDING...AND THE MOISTURE TRAPPED UNDER THE INVERSION IS MIXING OUT.
THE MOISTURE MAY BE TOUGHER TO SCOUR OUT OF THE HIGHER TERRAIN...AND
THIS MAY HAVE TO BE ACCOUNTED FOR IN THE EARLY MORNING FORECAST.
ELSEWHERE...THE LOWER CLOUDS SHOULD DISSIPATE BEFORE SUNRISE.
CONVECTIVE TEMPERATURES ARE OUT OF REACH TODAY...AND OTHER THAN SOME
HIGH CLOUDINESS THIS MORNING...SKIES SHOULD BE SUNNY. THE BEST PART
OF THE SURFACE PRESSURE GRADIENT IS OVER THE FORECAST AREA
NOW...AND SOME GUSTINESS LINGERS. THE GUSTINESS TO THE WIND SHOULD
DROP BACK EARLY THIS MORNING AS THE LAST OF THE COLD AIR ADVECTION
ENDS.
IT IS POSSIBLE THERE COULD BE SOME GUSTINESS JUST AFTER
SUNRISE...BUT FOR THE MOST PART WINDS SHOULD NOT BE AN ISSUE TODAY.
850 MB TEMPERATURES SUPPORT HIGHS IN THE MID 50S TODAY...WHICH IS
CLOSE TO THE MOS BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
BUILDING MID LEVEL RIDGING SHOULD KEEP ANY HIGH AND MID LEVEL CLOUDS
NORTH OF THE AREA TONIGHT...AND SKIES SHOULD BE CLEAR. AS THE HIGH
REACHES NORTH CAROLINA TONIGHT...THE GRADIENT WILL BACK OFF.
HOWEVER...WINDS MAY NOT BECOME COMPLETELY CALM OUTSIDE OF PROTECTED
AREAS...AS THE GRADIENT WOULD SUPPORT WEST WINDS LESS THAN 10 MPH.
THE ABOVE SCENARIO WOULD SUPPORTS LOWS NEAR THE MOS BLEND IN THE
URBAN AREAS AND PLACES WITH EXPOSURE. FOR PROTECTED AREAS (INCLUDING
THE PINE BARRENS IN NEW JERSEY)...LOWS WERE DROPPED A FEW DEGREES
FROM THE MOS MEAN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A QUIESCENT PERIOD OF WEATHER IS SHAPING UP FOR THE NORTHERN MID
ATLANTIC AREA FRIDAY INTO SUNDAY. THE MODELS HAVE LATCHED ONTO A
COLD FRONT WHICH LOOKS LIKE IT WILL AFFECT OUR AREA MAINLY SUNDAY
NIGHT INTO MONDAY. THEN...MODEL PERFORMANCE HAS SEEMINGLY
DETERIORATED OVER THE PAST 24 TO 48 HOURS, WITH RUN-TO-RUN AND
INTERMODEL INCONSISTENCY AND CHANGEABILITY. WITH NO CLEAR
SIGNALS...IT WAS DECIDED TO JUST USE A BROAD BRUSH OF CHANCE
PROBABILITIES FOR SHOWERS THROUGH THE MONDAY THROUGH WEDNESDAY
PERIOD, WITH A MODERATE TO HIGH AMOUNT OF CLOUDINESS. THE GFS EVEN
PAINTS SOME TYPE OF RAIN/SNOW EVENT WEDNESDAY NIGHT INTO THURSDAY.
LATER MODEL ITERATIONS WILL BE NEEDED TO GAIN MORE CLARITY ON THIS
PERIOD.
SO...HPC TEMPERATURES WERE USED AS A STARTING POINT FOR HIGHS AND
LOWS, WITH SOME MODIFICATIONS FOR LOCAL EFFECTS AND CLIMATOLOGY. A
GENERAL COOLING TREND SHOULD OCCUR THROUGH THE LONG TERM PERIOD...
WITH HIGHS IN THE MID 50S AND LOWER 60S OVER THE WEEKEND, DROPPING
TO THE 40S TO NEAR 50 BY WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL CONTINUE TO PROVIDE US WITH FINE VFR
FLYING CONDITIONS FRIDAY INTO...OR PERHAPS THROUGH MOST OF...SUNDAY.
A COLD FRONT MOVING IN FROM THE WEST SUNDAY NIGHT WILL MOVE EASTWARD
THROUGH OUR AREA. HOWEVER, A SUCCESSION OF LOWS COULD AFFECT OUR
REGION AND PERHAPS BRING LOWER CONDITIONS AT TIMES INTO THE EARLY OR
EVEN MIDDLE PORTION OF NEXT WEEK. MODEL GUIDANCE HAS BEEN CHANGING
AND INCONSISTENT...SO LITTLE IN THE WAY OF CONFIDENCE CAN BE SHOWN
UNTIL THE MODELS START TO OFFER BETTER AGREEMENT AND RUN-TO-RUN
CONSISTENCY. LOWER CEILINGS AND/OR VISIBILITIES IN SHOWERS/RAIN AND
FOG MAY OCCUR THROUGH MUCH OF THE SUNDAY NIGHT THROUGH WEDNESDAY
TIME PERIOD, THOUGH.
&&
.MARINE...
THE GRADIENT REMAINS IN PLACE MOST OF THE DAY...AND AT A GLANCE
DOES NOT APPEAR TO SUPPORT SMALL CRAFT WINDS ANYWHERE AFTER ABOUT
1500 UTC. THEREFORE...THE SMALL CRAFT ADVISORY THAT REPLACES THE
GALE WARNING WILL BE RUN UNTIL ABOUT 1500 UTC ON THE DELAWARE BAY
(AND IT MAY NOT EVEN BE NEEDED THAT LONG).
OVER THE OCEAN WATERS...SEAS ARE STILL RUNNING 5 TO 9 FEET...WITH
THE HIGHEST SEAS ACROSS THE SOUTHERN WATERS. WHILE WINDS SHOULD DROP
BELOW SMALL CRAFT LEVELS IN GUSTS BY 1500 UTC...THE SEAS ACROSS THE
SOUTHERN WATERS MAY TAKE LONGER TO SORT THEMSELVES OUT. BASED ON THE
ABOVE...THE SMALL CRAFT ADVISORY WILL BE RUN THROUGH ABOUT 1500 UTC
ACROSS THE NORTHERN OCEAN WATERS...AND ABOUT 1800 UTC ACROSS THE
SOUTHERN OCEAN WATERS.
AFTER THIS...THE GRADIENT LOOKS TO SUPPORT WINDS AROUND 15 KNOTS ON
THE OCEAN FOR THE REST OF TODAY INTO TONIGHT. WINDS ACROSS THE
DELAWARE BAY WILL BE SLIGHTLY LOWER...BUT PROBABLY DO NOT DROP BELOW
10 KNOTS...AS THE GRADIENT LOOKS TO SUPPORT WINDS OF THESE SPEEDS.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR MARINE
AREA FRIDAY THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST,
A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY. THE PRESSURE
GRADIENT WILL TIGHTEN BETWEEN THESE TWO SYSTEMS...AND THIS WILL MEAN
A GOOD CHANCE OF SHOWERS AS WELL AS INCREASING SOUTH TO SOUTHEAST
WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY. A SERIES OF LOW
PRESSURE SYSTEMS COULD AFFECT OUR AREA THROUGH THE EARLY AND MIDDLE
PORTIONS OF NEXT WEEK...BUT MODEL GUIDANCE HAS BECOME TOO CHANGEABLE
AND INCONSISTENT TO OFFER ANY KIND OF SPECIFICS. ADVISORY CONDITIONS
ARE LIKELY AT SOME POINT...AND EVEN GALE CONDITIONS MAY OCCUR FOR A
TIME...IN THE SUNDAY NIGHT TO MID WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
A FEW POINTS HAVE REACHED THE MINOR TIDAL FLOODING BENCHMARK ALONG
THE OCEANFRONT THIS MORNING (SANDY HOOK AND ATLANTIC CITY ARE
ALREADY THERE...AND CAPE MAY AND LEWES DELAWARE SHOULD FOLLOW
SHORTLY). THE DEPARTURES DECREASED AS HIGH TIDE APPROACHED (WHICH
IS TYPICAL IN AN NON-SURGE TIDE)...BUT STILL ENOUGH FOR MINOR
TIDAL FLOODING.
TIDE DEPARTURES ON THE UPPER DELAWARE BAY AND TIDAL PORTION OF
THE DELAWARE HAVE INCREASED STEADILY THIS MORNING. THE FACT THAT
WE WOULD ONLY NEED ABOUT ONE-HALF TO THREE-QUARTERS OF A FOOT OF
DEPARTURE FROM PREDICTED (WE ARE JUST ABOUT THERE NOW) SUGGESTS
THAT MINOR TIDAL FLOODING WILL OCCUR THERE AS WELL. BASED ON THE
ABOVE...AND THE RATE OF INCREASE OF DEPARTURES...A COASTAL FLOOD
ADVISORY HAS BEEN ISSUED FOR THE UPPER DELAWARE BAY AND TIDAL
SECTION OF THE DELAWARE RIVER.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
PAZ070-071.
NJ...COASTAL FLOOD ADVISORY UNTIL 9 AM EST THIS MORNING FOR
NJZ012>014-020-022>027.
COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ016>019-021.
DE...COASTAL FLOOD ADVISORY UNTIL 9 AM EST THIS MORNING FOR DEZ003-
004.
COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ001-002.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR ANZ450-
451.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ430-
431.
&&
$$
SYNOPSIS...
NEAR TERM...HAYES
SHORT TERM...HAYES
LONG TERM...
AVIATION...HAYES
MARINE...HAYES
TIDES/COASTAL FLOODING...HAYES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
817 AM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* CIGS AROUND 700 FT SLOWLY LIFTING INTO THE AFTERNOON AND MAY
REACH MVFR EARLY THIS AFTERNOON.
* IFR/LIFR CIGS REDEVELOPING THIS EVENING AND OVERNIGHT.
* PERIODS OF GUSTY SOUTHWEST WINDS TO AROUND 20 KT.
* POTENTIAL FOR LLWS TONIGHT.
MDB
//DISCUSSION...UPDATED 12Z...
VERY LARGE AREA OF IFR/LIFR CIGS EXTENDS FROM THE GREAT LAKES
SOUTH TO THE ARKLATEX THIS MORNING. LOCALLY THESE CLOUDS ARE
TRAPPED UNDER A VERY STRONG INVERSION JUST A FEW THOUSAND FEET
ALOFT AND IT WILL LIKELY BE UNTIL AT LEAST EARLY THIS AFTERNOON
BEFORE THESE CLOUDS POTENTIALLY SHOW SOME BREAKS OR SCATTER OUT.
WHILE CIGS SHOULD SLOWLY DIURNALLY LIFT THROUGH IFR INTO LOW MVFR
THIS AFTERNOON...CONFIDENCE ON TIMING AND SPECIFIC HEIGHTS IS LOW.
THE INVERSION ALOFT BECOMES EVEN STRONGER TONIGHT AND WITH LOW
LEVEL MOISTURE STILL STREAMING NORTH...SHOULD CLOUDS SCATTER OUT
THEY SHOULD QUICKLY REDEVELOP BY LATE EVENING/EARLY FRIDAY
MORNING. THOUGH THE INVERSION DOES MIX OUT RATHER QUICKLY AFTER
SUNRISE FRIDAY MORNING. VISIBILITIES HAVE GENERALLY BEEN IN THE
2-4SM RANGE MOST AREAS AND NOT EXPECTING ANYTHING MUCH LOWER THAN
THAT...AT LEAST NOT ANYTHING WIDESPREAD. THE VIS SHOULD IMPROVE
THROUGH THE MORNING BUT LIKELY DROP BACK INTO MVFR THIS EVENING
AND OVERNIGHT.
DESPITE THE LOW INVERSION...WINDS HAVE GUSTED IN THE 15-20KT
RANGE DURING THE EARLY MORNING HRS AND EXPECT GUSTS IN THIS RANGE
FOR MUCH OF THE DAY...WITH THE POTENTIAL FOR SOME HIGHER GUSTS
DURING THE AFTERNOON SHOULD LOW CLOUDS SCATTER OUT. GRADIENT
REMAINS TIGHT THROUGH THE NIGHT AND LOW LEVEL WINDS ALOFT INCREASE
TO 40-45 KTS BY 2KFT...THUS THE POTENTIAL FOR LLWS. HAVE OPTED TO
LEAVE THIS OUT OF THIS FORECAST SINCE IT IS QUITE POSSIBLE SURFACE
WINDS WILL BE GUSTY AND CONFIDENCE REGARDING MEETING LLWS CRITERIA
IS LOW. CMS
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM CONFIDENCE IFR CIGS WILL LIFT TO LOW MVFR EARLY THIS
AFTERNOON...LOW CONFIDENCE ON TIMING AND IF CIGS WILL LIFT TO
MUCH ABOVE 1000 FT.
* LOW CONFIDENCE LOW MVFR CIGS WILL SCATTER OUT THIS AFTERNOON.
* MEDIUM CONFIDENCE IFR CIGS WILL REDEVELOP THIS EVENING AND
PERSIST INTO MID MORNING FRIDAY.
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* LOW CONFIDENCE REGARDING LLWS TONIGHT.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. CHANCE OF SHRA.
SATURDAY...MVFR WITH IFR POSSIBLE. PERIODS OF RAIN DURING THE DAY.
CHANCE OF SHRA/SHSN SATURDAY NIGHT.
SUNDAY...MVFR POSSIBLE. CHANCE OF SHRA/SHSN.
MONDAY THROUGH WEDNESDAY...VFR. CMS
&&
.MARINE...
300 AM CST
WINDS HAVE BEEN A LITTLE SLOW TO INCREASE THIS MORNING DESPITE A
FAIRLY TIGHT PRESSURE GRADIENT AND STRONG FLOW ALOFT IN PLACE. WITH
TWO SEPARATE AREAS OF LOW PRESSURE TO THE NORTH AND NORTHWEST OF THE
LAKE AND A RIDGE OF HIGH PRESSURE JUST TO THE SOUTHEAST...STRONG
SOUTHERLY FLOW CONTINUES TO USHER IN WARMER AIR TO THE NORTH.
BELIEVE THIS IS WHAT MAY BE CAUSING THIS SLOW INCREASE IN WIND SPEED
AS A SLIGHTLY MORE STABLE LAKE MAY BE IN PLACE THAN WHAT CURRENT
GUIDANCE IS INDICATING. NONETHELESS...WINDS WILL CONTINUE TO
INCREASE TODAY AS THIS TIGHT PRESSURE GRADIENT REMAINS AND FLOW
ALOFT INCREASES. PERSISTENT SOUTHWEST WINDS TO 30 KT CAN BE EXPECTED
INTO FRIDAY FOR BOTH THE NORTH AND SOUTH HALF OF LAKE MICHIGAN. HAVE
LEFT OUT ANY MENTION OF GALES FOR THE LAKE THIS FORECAST
ISSUANCE...BUT DO THINK THERE MAY BE BRIEF PERIODS OF HIGHER WINDS
AROUND GALES LATE THIS AFTERNOON AND EARLY EVENING MAINLY FOR THE
NORTH HALF OF THE LAKE. ALTHOUGH DO FEEL THAT THIS WILL BE SPORADIC
AND BRIEF...THUS LEAVING ANY MENTION OF GALES OUT OF THE CURRENT
FORECAST. SOUTHWEST WINDS WILL SLOWLY BEGIN TO DIMINISH FRIDAY NIGHT
INTO SATURDAY...BUT WILL BECOME MORE WESTERLY ON SATURDAY AS AN AREA
OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY PUSH ACROSS THE
LAKE. THEN A PERIOD OF WEST TO NORTHWEST WINDS CAN BE EXPECTED INTO
THE START OF NEXT WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
601 AM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* IFR/LIFR CIGS LIFTING TO LOW MVFR THIS AFTERNOON.
* IFR/LIFR CIGS REDEVELOPING THIS EVENING AND OVERNIGHT.
* PERIODS OF GUSTY SOUTHWEST WINDS.
* POTENTIAL FOR LLWS TONIGHT. CMS
//DISCUSSION...UPDATED 12Z...
VERY LARGE AREA OF IFR/LIFR CIGS EXTENDS FROM THE GREAT LAKES
SOUTH TO THE ARKLATEX THIS MORNING. LOCALLY THESE CLOUDS ARE
TRAPPED UNDER A VERY STRONG INVERSION JUST A FEW THOUSAND FEET
ALOFT AND IT WILL LIKELY BE UNTIL AT LEAST EARLY THIS AFTERNOON
BEFORE THESE CLOUDS POTENTIALLY SHOW SOME BREAKS OR SCATTER OUT.
WHILE CIGS SHOULD SLOWLY DIURNALLY LIFT THROUGH IFR INTO LOW MVFR
THIS AFTERNOON...CONFIDENCE ON TIMING AND SPECIFIC HEIGHTS IS LOW.
THE INVERSION ALOFT BECOMES EVEN STRONGER TONIGHT AND WITH LOW
LEVEL MOISTURE STILL STREAMING NORTH...SHOULD CLOUDS SCATTER OUT
THEY SHOULD QUICKLY REDEVELOP BY LATE EVENING/EARLY FRIDAY
MORNING. THOUGH THE INVERSION DOES MIX OUT RATHER QUICKLY AFTER
SUNRISE FRIDAY MORNING. VISIBILITIES HAVE GENERALLY BEEN IN THE
2-4SM RANGE MOST AREAS AND NOT EXPECTING ANYTHING MUCH LOWER THAN
THAT...AT LEAST NOT ANYTHING WIDESPREAD. THE VIS SHOULD IMPROVE
THROUGH THE MORNING BUT LIKELY DROP BACK INTO MVFR THIS EVENING
AND OVERNIGHT.
DESPITE THE LOW INVERSION...WINDS HAVE GUSTED IN THE 15-20KT
RANGE DURING THE EARLY MORNING HRS AND EXPECT GUSTS IN THIS RANGE
FOR MUCH OF THE DAY...WITH THE POTENTIAL FOR SOME HIGHER GUSTS
DURING THE AFTERNOON SHOULD LOW CLOUDS SCATTER OUT. GRADIENT
REMAINS TIGHT THROUGH THE NIGHT AND LOW LEVEL WINDS ALOFT INCREASE
TO 40-45 KTS BY 2KFT...THUS THE POTENTIAL FOR LLWS. HAVE OPTED TO
LEAVE THIS OUT OF THIS FORECAST SINCE IT IS QUITE POSSIBLE SURFACE
WINDS WILL BE GUSTY AND CONFIDENCE REGARDING MEETING LLWS CRITERIA
IS LOW. CMS
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM CONFIDENCE LIFR/IFR CIGS WILL LIFT TO LOW MVFR BY EARLY
AFTERNOON...LOW CONFIDENCE ON TIMING.
* LOW CONFIDENCE LOW MVFR CIGS WILL SCATTER OUT THIS AFTERNOON.
* MEDIUM CONFIDENCE IFR CIGS WILL REDEVELOP THIS EVENING AND
PERSIST INTO MID MORNING FRIDAY.
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* LOW CONFIDENCE REGARDING LLWS TONIGHT. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. CHANCE OF SHRA.
SATURDAY...MVFR WITH IFR POSSIBLE. PERIODS OF RAIN DURING THE DAY.
CHANCE OF SHRA/SHSN SATURDAY NIGHT.
SUNDAY...MVFR POSSIBLE. CHANCE OF SHRA/SHSN.
MONDAY THROUGH WEDNESDAY...VFR. CMS
&&
.MARINE...
300 AM CST
WINDS HAVE BEEN A LITTLE SLOW TO INCREASE THIS MORNING DESPITE A
FAIRLY TIGHT PRESSURE GRADIENT AND STRONG FLOW ALOFT IN PLACE. WITH
TWO SEPARATE AREAS OF LOW PRESSURE TO THE NORTH AND NORTHWEST OF THE
LAKE AND A RIDGE OF HIGH PRESSURE JUST TO THE SOUTHEAST...STRONG
SOUTHERLY FLOW CONTINUES TO USHER IN WARMER AIR TO THE NORTH.
BELIEVE THIS IS WHAT MAY BE CAUSING THIS SLOW INCREASE IN WIND SPEED
AS A SLIGHTLY MORE STABLE LAKE MAY BE IN PLACE THAN WHAT CURRENT
GUIDANCE IS INDICATING. NONETHELESS...WINDS WILL CONTINUE TO
INCREASE TODAY AS THIS TIGHT PRESSURE GRADIENT REMAINS AND FLOW
ALOFT INCREASES. PERSISTENT SOUTHWEST WINDS TO 30 KT CAN BE EXPECTED
INTO FRIDAY FOR BOTH THE NORTH AND SOUTH HALF OF LAKE MICHIGAN. HAVE
LEFT OUT ANY MENTION OF GALES FOR THE LAKE THIS FORECAST
ISSUANCE...BUT DO THINK THERE MAY BE BRIEF PERIODS OF HIGHER WINDS
AROUND GALES LATE THIS AFTERNOON AND EARLY EVENING MAINLY FOR THE
NORTH HALF OF THE LAKE. ALTHOUGH DO FEEL THAT THIS WILL BE SPORADIC
AND BRIEF...THUS LEAVING ANY MENTION OF GALES OUT OF THE CURRENT
FORECAST. SOUTHWEST WINDS WILL SLOWLY BEGIN TO DIMINISH FRIDAY NIGHT
INTO SATURDAY...BUT WILL BECOME MORE WESTERLY ON SATURDAY AS AN AREA
OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY PUSH ACROSS THE
LAKE. THEN A PERIOD OF WEST TO NORTHWEST WINDS CAN BE EXPECTED INTO
THE START OF NEXT WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
405 AM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 10Z...
* IFR/LIFR CIGS THROUGH MID/LATE MORNING.
* GUSTY SOUTHWEST WINDS THROUGH THE PERIOD...PRIMARILY THIS
AFTERNOON.
* LLWS POTENTIAL TONIGHT. CMS
//DISCUSSION...UPDATED 06Z...
STRATUS DECK CONTINUES TO SPREAD ACROSS THE REGION AND WILL BE
OVER ALL TERMINALS WITHIN THE NEXT HOUR. CIGS QUICKLY DROPPED
FROM LOW END MVFR TO HIGH TO MIDDLE RANGE IFR. VERY STRONG
SUBSIDENCE INVERSION NOTED ON THE 00Z RAOB OUT OF DVN...AND WOULD
EXPECT THE STRATUS DECK TO REMAIN THROUGH THE MORNING HOURS. WARM
AIR ADVECTION WILL BEGIN TO RAMP UP AND BOUNDARY LAYER FLOW WILL
ALSO INCREASE INTO THE MORNING...AND IT IS THEN THAT THE CLOUDS
SHOULD LIFT AND THEN BEGIN TO ERODE. INTO THE AFTERNOON
HOURS...EFFICIENT MIXING WILL ALLOW GUSTS IN THE AFTERNOON TO
REACH INTO THE LOWER 20KT RANGE AND WILL LAST UNTIL SUN DOWN. AS
GUSTS FALL OFF...THE POTENTIAL EXISTS FOR LLWS INTO THE EVENING
HOURS. FORECAST SOUNDINGS SHOWING ROUGHLY 40KT AT 02KFT...JUST
FLIRTING WITH CRITERIA. FOR NOW...WILL WITHHOLD ANYTHING IN THE
ORD TAFOR.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 10Z...
* HIGH CONFIDENCE IFR/LIFR CIGS WILL PERSIST THROUGH MID/LATE
MORNING.
* MEDIUM CONFIDENCE CIGS WILL LIFT/SCATTER OUT THIS AFTERNOON...
LOW CONFIDENCE ON TIMING.
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* LOW CONFIDENCE IN MEETING LLWS CRITERIA TONIGHT. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...VFR
* SATURDAY...RA. MVFR LIKELY WITH IFR POSSIBLE
* SUNDAY THROUGH TUESDAY...MVFR. SHRA WITH POSSIBLE RASN OVERNIGHT
SHEA
&&
.MARINE...
300 AM CST
WINDS HAVE BEEN A LITTLE SLOW TO INCREASE THIS MORNING DESPITE A
FAIRLY TIGHT PRESSURE GRADIENT AND STRONG FLOW ALOFT IN PLACE. WITH
TWO SEPARATE AREAS OF LOW PRESSURE TO THE NORTH AND NORTHWEST OF THE
LAKE AND A RIDGE OF HIGH PRESSURE JUST TO THE SOUTHEAST...STRONG
SOUTHERLY FLOW CONTINUES TO USHER IN WARMER AIR TO THE NORTH.
BELIEVE THIS IS WHAT MAY BE CAUSING THIS SLOW INCREASE IN WIND SPEED
AS A SLIGHTLY MORE STABLE LAKE MAY BE IN PLACE THAN WHAT CURRENT
GUIDANCE IS INDICATING. NONETHELESS...WINDS WILL CONTINUE TO
INCREASE TODAY AS THIS TIGHT PRESSURE GRADIENT REMAINS AND FLOW
ALOFT INCREASES. PERSISTENT SOUTHWEST WINDS TO 30 KT CAN BE EXPECTED
INTO FRIDAY FOR BOTH THE NORTH AND SOUTH HALF OF LAKE MICHIGAN. HAVE
LEFT OUT ANY MENTION OF GALES FOR THE LAKE THIS FORECAST
ISSUANCE...BUT DO THINK THERE MAY BE BRIEF PERIODS OF HIGHER WINDS
AROUND GALES LATE THIS AFTERNOON AND EARLY EVENING MAINLY FOR THE
NORTH HALF OF THE LAKE. ALTHOUGH DO FEEL THAT THIS WILL BE SPORADIC
AND BRIEF...THUS LEAVING ANY MENTION OF GALES OUT OF THE CURRENT
FORECAST. SOUTHWEST WINDS WILL SLOWLY BEGIN TO DIMINISH FRIDAY NIGHT
INTO SATURDAY...BUT WILL BECOME MORE WESTERLY ON SATURDAY AS AN AREA
OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY PUSH ACROSS THE
LAKE. THEN A PERIOD OF WEST TO NORTHWEST WINDS CAN BE EXPECTED INTO
THE START OF NEXT WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1053 AM EST THU NOV 24 2011
.UPDATE...
STAUNCH LL INVERSION IN PLACE PER RAOB/TAMDAR ANALYSIS WITH WAA
REGIME ONGOING ACROSS THE FA. LL MOISTURE REMAINS TRAPPED BELOW
THE INVERSION BASE...WHICH IS JUST ABOVE H95...AND INCREASING FLOW
WILL LIKELY BE TOO LITTLE TO SUPPORT MIX OUT OF STRATUS TODAY.
SATELLITE CONFIRMS STRATUS DECK STRETCHING BACK TO TX...AND GIVEN
LOW SUN ANGLE AND A RE-ENFORCING INVERSION PER WAA...HAVE UPDATED
SKY GRIDS TO HOLD CLOUDY MENTION THROUGH THE DAY. THE POTENTIAL
FOR A FEW BREAKS LINGERS ACROSS THE NW THIRD GIVEN THE INCREASED
POTENTIAL FOR TURBULENT BL TOP MIXING...ALBEIT SMALL ATTM.
OTHERWISE...EVEN WITH THE LACK OF STRONG INSOLATION TEMPS WILL
CONTINUE TO CLIMB THROUGH AFTERNOON GIVEN SIG WAA. HOWEVER...MOST
AREAS WILL FALL SHORT OF 50...SAVE THE NW WHERE THERMAL ADVECTION
WILL BE THE STRONGEST.
&&
.PREV DISCUSSION... /ISSUED 635 AM EST THU NOV 24 2011/
AVIATION...
STRATUS HAS ENVELOPED ENTIRE AREA WITH IFR CONDITIONS AT BOTH TAF
SITES. AMDAR SOUNDINGS AND PIREPS INDICATE MOISTURE DEPTH ABOUT 1KFT
WITH DRY AIR ABOVE. VERY STRONG INVERSION OF NEARLY 15 DEGREES SEEN
IN ONE AMDAR SOUNDING EARLIER THIS MORNING. WILL BE DIFFICULT TO MIX
THIS MOISTURE OUT BUT WIND FIELD HAS INCREASED AND YEILDS SOME HOPE
FOR AFTERNOON BREAKS. HOWEVER...HRRR RUNS FOR LOW CLOUD PRODUCT HAS
BEEN HANDLING THIS STRATUS VERY WELL AND CONTINUES TO SHOW ONLY A
SMALL CONTRACTION OF STRATUS WITH FEW BREAKS THROUGH LATE AFTERNOON.
THEREFORE HAVE SHOWN ONLY SLIGHT IMPROVEMENTS IN CIGS TODAY BUT VIS
SHOULD IMPROVE TO P6SM WITH WIND LATER THIS MORNING. SIMILAR
CONDITIONS TONIGHT SO EXPECT STRATUS TO FILL BACK IN. WINDS WILL BE
INCREASING THROUGH THE NIGHT IN LOWER LEVELS SO POSSIBLE THIS COULD
HELP MIX STRATUS LAYER LATE TONIGHT.
SHORT TERM...
AS FEARED...POTENTIAL WRINKLES IN TERMS OF STRATUS AND FOG CAME TO
FRUITION OVERNIGHT AND ARE CAUSE FOR SIGNIFICANT CHANGES TO SHORT
TERM FORECAST GRIDS. 11-3.9 MICRON SATELLITE IMAGE SHOWS LARGE AREA
OF STRATUS ACROSS THE MS AND OH RIVER VALLEY REGIONS AND QUICKLY
EXPANDING NORTHEAST ACROSS OUR AREA AS OF 08Z. 1000MB SW FLOW OF 5
TO 10 KNOTS AIDING IN MOVING STRATUS NORTHEAST. THE ENTIRE SHORT
TERM FORECAST HINGES ON WHAT THIS STRATUS DECK DOES OVER NEXT 24
HOURS AND HENCE THE SHORT TERM PROBLEM OF THE DAY.
NAM12 AND RUC HAVE SOME CLUE THAT STRATUS EXISTS BUT HRRR SEEMS TO
HAVE BEST HANDLE BY FAR. MOS GUIDANCE HAS NO CLUE WITH CLOUD COVER
CATEGORIES MAINLY CLEAR THROUGH THE PERIOD AND EVEN LAMP GUIDANCE AS
OF 08Z HAS NO INDICATION. THUS MOS TEMPS NOT CLOSE TODAY FOR
OPTIMISTIC 50S UNLESS CLOUD COVER ERODES QUICKLY WHICH IS DOUBTFUL
AT THIS TIME. NAM12 BUFKIT SOUNDINGS SHOW SATURATED SURFACE TO 1KFT
LAYER WITH STRONG INVERSION AND VERY DRY AIR ABOVE. WHILE YESTERDAYS
MODEL RUNS MIXED THE LOWER LEVELS...LATEST RUNS ARE MUCH STRONGER
WITH INVERSION AND SLIGHTLY DEEPER WITH MOIST LAYER LEADING TO
LITTLE MIXING UNTIL LATE AFTERNOON. LATEST HRRR LOW CLOUD PRODUCT
HAD STRATUS AREA NAILED AT INITIATION AND KEEPS IT LOCKED THROUGH
ITS VALID PERIOD WHICH IS MID AFTERNOON. HRRR 2M TEMPS ALSO REMAIN
IN UPPER 30S AND LOWER 40S THROUGH MID AFTERNOON. ALSO SOME CONCERN
FOR DRIZZLE FOR A FEW HOURS AFTER SUNRISE AS TURBULENT MIXING OF
SHALLOW CLOUD TOPS OFTEN LEADS TO PERIOD OF LIGHT
PRECIPITATION...ESPECIALLY WHEN SUB CLOUD LAYER IS MOIST WITH BR OR
FOG. HAVE ADDED A CHANCE FOR DRIZZLE TO ACCOUNT FOR THIS POSSIBILITY
THROUGH MID MORNING.
A LOOK BACK AT SATELLITE TRENDS ON WEDNESDAY REVEALED VERY LITTLE
MIXING OF STRATUS AND THUS CONCERNED FOR SIMILAR TREND TODAY INTO
TONIGHT. SUBTLE DIFFERENCE TODAY WILL BE INCREASING WINDS IN THE
1000-925MB LAYER... ESPECIALLY ABOVE 950MB WITH 40 TO 50 KNOTS
DEVELOPING LATE TONIGHT. HOWEVER...THIS WILL BE JUST ABOVE INVERSION
AND MAY NOT BE ENOUGH TO MIX OUT LOWER STRATUS DECK GIVEN STRONG
INVERSION IN PLACE. 1000MB WINDS LOOK TO INCREASE BUT ONLY IN THE 5
TO 15 KNOT RANGE WITH LIGHTER WINDS UPSTREAM WHERE STRATUS COULD
REDEVELOP AND AGAIN ADVECT BACK IN.
AFTER MUCH COLLABORATION HAVE OPTED FOR CLOUDY CONDITIONS THROUGH
EARLY AFTERNOON WITH A SUBTLE OPTIMISTIC TRANSITION TO PARTLY CLOUDY
MID TO LATE AFTERNOON. KEPT SKY COVER IN PARTLY CLOUDY RANGE TONIGHT
WITH UNCERTAINTY CONTINUING AS TO DEGREE OF REDEVELOPMENT IF WE
ACTUALLY DO BREAK OUT THIS AFTERNOON. STRONGER FLOW ON FRIDAY AHEAD
OF NEXT SYSTEM SUGGEST ANY REMAINING STRATUS WOULD MIX OUT MID TO
LATE MORNING.
TEMPS OBVIOUSLY WILL BE IMPACTED SIGNIFICANTLY WITH THIS STRATUS.
HAVE LOWERED HIGHS TODAY SEVERAL DEGREES BUT LIKELY NOT NEARLY
ENOUGH IF CLOUDS PERSIST ALL DAY. HAVE TO RESPECT PARTIAL CLEARING
IN AFTERNOON SO DID NOT GO AS LOW AS COLDEST MODEL BLENDS. 06Z NAM12
KEEPING TEMPS IN 30S ALL AREAS TODAY. MINS TONIGHT NOW HEAVILY
DEPENDENT ON ACTUAL MAX TEMPS TODAY BUT EXPECT LITTLE DROP OFF WITH
DECENT GRADIENT AND CLOUD POTENTIAL. KEPT TEMPS IN LOW TO MID 40S
TONIGHT. HIGHS ON FRIDAY STILL LOOK TO BE NEAR 60 WITH BETTER MIXING
BUT CONCERNS CONTINUE FOR LINGERING STRATUS IN THE MORNING.
LONG TERM.../SATURDAY THROUGH WEDNESDAY/
FEW SIG CHANGES TO LONG TERM WITH MODEL TURMOIL STILL ABUNDANT
THROUGH THE PERIOD. ARRIVAL OF TROUGH FROM THE WEST AND ASSOCIATED
PRECIP STILL NOT MUCH CLEARER WITH NAM/GFS SPREADING RAIN ACROSS THE
AREA MID MORNING WEST INTO AFTERNOON EAST VS ECMWF MORE QUICK
AFTERNOON ARRIVAL WEST TO EAST. THESE FASTER SOLUTIONS ALSO PUSHES
PRECIP OUT AFTER 6Z SUN IN WESTERN AREAS. THINK COMPROMISE STILL
NEEDED IN MODELS...MEANING GENERALLY SAME FORECAST FOR SAT/SAT NGT.
TEMPS STILL GOING TO BE TRICKY BUT WITH INCREASING MID/HIGH CLOUDS
THINK THEY WILL BE KEPT IN CHECK ESPECIALLY WEST. HAVE INCREASED SKY
COVER TO REFLECT FASTER CLOUD ARRIVAL.
ECMWF ONLY MODEL THAT STARTS PROGRESSIVE SUNDAY WITH GFS/GEFS/GEM
ALL SHOWING CLOSED UPPER LOW ACROSS THE GREAT LAKES /IN VARYING
LOCATIONS/. WITH TIME...ECMWF AND GEM CONTINUE A DEPICTION OF RAPID
DEEPENING OF UPPER LOW AND MAJOR TRANSLATION SOUTHWARD IN ENERGY.
GFS/GEFS HOLD WITH NORTHERN INFLUENCE BEING STRONGER. NEXT TROUGH
WILL MOVE INTO THE AREA MONDAY NIGHT INTO TUESDAY AND INTERACT WITH
CLOSED LOW WHEREVER IT MAY BE. THINK THERE WILL BE AT LEAST A
DECENT SHOT FOR PRECIP UNDER THE UPPER LOW WITH COOL NW FLOW ACROSS
THE LAKE AND SYNOPTIC MSTR STILL ACROSS THE AREA. IN
ADDITION...PIECE OF ENERGY SHOULD ROTATE ACROSS THE AREA ON SUNDAY.
WILL MAINTAIN MID RANGE CHC POPS FOR NOW WITH POSSIBLE INCREASE TO
LIKELY WITH TIME. BASED ON THERMAL PROFILES...HAVE OPTED TO THROW IN
MIX MENTION FOR THE DAY AS 1000-850 MB VALUES DROP TO NEAR OR BELOW
1300 M.
HAVE ONLY MADE MINOR TWEAKS TO POPS FROM CR INIT TO PLACE HIGHER
EMPHASIS ON PAST VS PRESENT WITH SLIGHTLY HIGHER POPS. WHILE AN
OUTLIER...IF ECMWF SOLUTION OF UPPER LOW EVENTUALLY WORKING NORTH
TOWARDS THE AREA MON NGT INTO TUES NGT BODES TRUE...COULD BE RATHER
WET. ECMWF HAS BEEN VERY VARIABLE OF LATE...BUT NO WORSE THAN SOME
OF THE OTHERS LEADING TO AT LEAST CONSIDERATION OF THE SCENARIO.
REGARDLESS OF SOLUTIONS...NORMAL TO BELOW NORMAL TEMPS WILL BE IN
STORE SUNDAY AND BEYOND.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR LMZ043-046.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...LASHLEY
UPDATE...JC
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
635 AM EST THU NOV 24 2011
.AVIATION...
STRATUS HAS ENVELOPED ENTIRE AREA WITH IFR CONDITIONS AT BOTH TAF
SITES. AMDAR SOUNDINGS AND PIREPS INDICATE MOISTURE DEPTH ABOUT 1KFT
WITH DRY AIR ABOVE. VERY STRONG INVERSION OF NEARLY 15 DEGREES SEEN
IN ONE AMDAR SOUNDING EARLIER THIS MORNING. WILL BE DIFFICULT TO MIX
THIS MOISTURE OUT BUT WIND FIELD HAS INCREASED AND YEILDS SOME HOPE
FOR AFTERNOON BREAKS. HOWEVER...HRRR RUNS FOR LOW CLOUD PRODUCT HAS
BEEN HANDLING THIS STRATUS VERY WELL AND CONTINUES TO SHOW ONLY A
SMALL CONTRACTION OF STRATUS WITH FEW BREAKS THROUGH LATE AFTERNOON.
THEREFORE HAVE SHOWN ONLY SLIGHT IMPROVEMENTS IN CIGS TODAY BUT VIS
SHOULD IMPROVE TO P6SM WITH WIND LATER THIS MORNING. SIMILAR
CONDITIONS TONIGHT SO EXPECT STRATUS TO FILL BACK IN. WINDS WILL BE
INCREASING THROUGH THE NIGHT IN LOWER LEVELS SO POSSIBLE THIS COULD
HELP MIX STRATUS LAYER LATE TONIGHT.
&&
.SHORT TERM...
AS FEARED...POTENTIAL WRINKLES IN TERMS OF STRATUS AND FOG CAME TO
FRUITION OVERNIGHT AND ARE CAUSE FOR SIGNIFICANT CHANGES TO SHORT
TERM FORECAST GRIDS. 11-3.9 MICRON SATELLITE IMAGE SHOWS LARGE AREA
OF STRATUS ACROSS THE MS AND OH RIVER VALLEY REGIONS AND QUICKLY
EXPANDING NORTHEAST ACROSS OUR AREA AS OF 08Z. 1000MB SW FLOW OF 5
TO 10 KNOTS AIDING IN MOVING STRATUS NORTHEAST. THE ENTIRE SHORT
TERM FORECAST HINGES ON WHAT THIS STRATUS DECK DOES OVER NEXT 24
HOURS AND HENCE THE SHORT TERM PROBLEM OF THE DAY.
NAM12 AND RUC HAVE SOME CLUE THAT STRATUS EXISTS BUT HRRR SEEMS TO
HAVE BEST HANDLE BY FAR. MOS GUIDANCE HAS NO CLUE WITH CLOUD COVER
CATEGORIES MAINLY CLEAR THROUGH THE PERIOD AND EVEN LAMP GUIDANCE AS
OF 08Z HAS NO INDICATION. THUS MOS TEMPS NOT CLOSE TODAY FOR
OPTIMISTIC 50S UNLESS CLOUD COVER ERODES QUICKLY WHICH IS DOUBTFUL
AT THIS TIME. NAM12 BUFKIT SOUNDINGS SHOW SATURATED SURFACE TO 1KFT
LAYER WITH STRONG INVERSION AND VERY DRY AIR ABOVE. WHILE YESTERDAYS
MODEL RUNS MIXED THE LOWER LEVELS...LATEST RUNS ARE MUCH STRONGER
WITH INVERSION AND SLIGHTLY DEEPER WITH MOIST LAYER LEADING TO
LITTLE MIXING UNTIL LATE AFTERNOON. LATEST HRRR LOW CLOUD PRODUCT
HAD STRATUS AREA NAILED AT INITIATION AND KEEPS IT LOCKED THROUGH
ITS VALID PERIOD WHICH IS MID AFTERNOON. HRRR 2M TEMPS ALSO REMAIN
IN UPPER 30S AND LOWER 40S THROUGH MID AFTERNOON. ALSO SOME CONCERN
FOR DRIZZLE FOR A FEW HOURS AFTER SUNRISE AS TURBULENT MIXING OF
SHALLOW CLOUD TOPS OFTEN LEADS TO PERIOD OF LIGHT
PRECIPITATION...ESPECIALLY WHEN SUB CLOUD LAYER IS MOIST WITH BR OR
FOG. HAVE ADDED A CHANCE FOR DRIZZLE TO ACCOUNT FOR THIS POSSIBILITY
THROUGH MID MORNING.
A LOOK BACK AT SATELLITE TRENDS ON WEDNESDAY REVEALED VERY LITTLE
MIXING OF STRATUS AND THUS CONCERNED FOR SIMILAR TREND TODAY INTO
TONIGHT. SUBTLE DIFFERENCE TODAY WILL BE INCREASING WINDS IN THE
1000-925MB LAYER... ESPECIALLY ABOVE 950MB WITH 40 TO 50 KNOTS
DEVELOPING LATE TONIGHT. HOWEVER...THIS WILL BE JUST ABOVE INVERSION
AND MAY NOT BE ENOUGH TO MIX OUT LOWER STRATUS DECK GIVEN STRONG
INVERSION IN PLACE. 1000MB WINDS LOOK TO INCREASE BUT ONLY IN THE 5
TO 15 KNOT RANGE WITH LIGHTER WINDS UPSTREAM WHERE STRATUS COULD
REDEVELOP AND AGAIN ADVECT BACK IN.
AFTER MUCH COLLABORATION HAVE OPTED FOR CLOUDY CONDITIONS THROUGH
EARLY AFTERNOON WITH A SUBTLE OPTIMISTIC TRANSITION TO PARTLY CLOUDY
MID TO LATE AFTERNOON. KEPT SKY COVER IN PARTLY CLOUDY RANGE TONIGHT
WITH UNCERTAINTY CONTINUING AS TO DEGREE OF REDEVELOPMENT IF WE
ACTUALLY DO BREAK OUT THIS AFTERNOON. STRONGER FLOW ON FRIDAY AHEAD
OF NEXT SYSTEM SUGGEST ANY REMAINING STRATUS WOULD MIX OUT MID TO
LATE MORNING.
TEMPS OBVIOUSLY WILL BE IMPACTED SIGNIFICANTLY WITH THIS STRATUS.
HAVE LOWERED HIGHS TODAY SEVERAL DEGREES BUT LIKELY NOT NEARLY
ENOUGH IF CLOUDS PERSIST ALL DAY. HAVE TO RESPECT PARTIAL CLEARING
IN AFTERNOON SO DID NOT GO AS LOW AS COLDEST MODEL BLENDS. 06Z NAM12
KEEPING TEMPS IN 30S ALL AREAS TODAY. MINS TONIGHT NOW HEAVILY
DEPENDENT ON ACTUAL MAX TEMPS TODAY BUT EXPECT LITTLE DROP OFF WITH
DECENT GRADIENT AND CLOUD POTENTIAL. KEPT TEMPS IN LOW TO MID 40S
TONIGHT. HIGHS ON FRIDAY STILL LOOK TO BE NEAR 60 WITH BETTER MIXING
BUT CONCERNS CONTINUE FOR LINGERING STRATUS IN THE MORNING.
&&
.LONG TERM.../SATURDAY THROUGH WEDNESDAY/
FEW SIG CHANGES TO LONG TERM WITH MODEL TURMOIL STILL ABUNDANT
THROUGH THE PERIOD. ARRIVAL OF TROUGH FROM THE WEST AND ASSOCIATED
PRECIP STILL NOT MUCH CLEARER WITH NAM/GFS SPREADING RAIN ACROSS THE
AREA MID MORNING WEST INTO AFTERNOON EAST VS ECMWF MORE QUICK
AFTERNOON ARRIVAL WEST TO EAST. THESE FASTER SOLUTIONS ALSO PUSHES
PRECIP OUT AFTER 6Z SUN IN WESTERN AREAS. THINK COMPROMISE STILL
NEEDED IN MODELS...MEANING GENERALLY SAME FORECAST FOR SAT/SAT NGT.
TEMPS STILL GOING TO BE TRICKY BUT WITH INCREASING MID/HIGH CLOUDS
THINK THEY WILL BE KEPT IN CHECK ESPECIALLY WEST. HAVE INCREASED SKY
COVER TO REFLECT FASTER CLOUD ARRIVAL.
ECMWF ONLY MODEL THAT STARTS PROGRESSIVE SUNDAY WITH GFS/GEFS/GEM
ALL SHOWING CLOSED UPPER LOW ACROSS THE GREAT LAKES /IN VARYING
LOCATIONS/. WITH TIME...ECMWF AND GEM CONTINUE A DEPICTION OF RAPID
DEEPENING OF UPPER LOW AND MAJOR TRANSLATION SOUTHWARD IN ENERGY.
GFS/GEFS HOLD WITH NORTHERN INFLUENCE BEING STRONGER. NEXT TROUGH
WILL MOVE INTO THE AREA MONDAY NIGHT INTO TUESDAY AND INTERACT WITH
CLOSED LOW WHEREVER IT MAY BE. THINK THERE WILL BE AT LEAST A
DECENT SHOT FOR PRECIP UNDER THE UPPER LOW WITH COOL NW FLOW ACROSS
THE LAKE AND SYNOPTIC MSTR STILL ACROSS THE AREA. IN
ADDITION...PIECE OF ENERGY SHOULD ROTATE ACROSS THE AREA ON SUNDAY.
WILL MAINTAIN MID RANGE CHC POPS FOR NOW WITH POSSIBLE INCREASE TO
LIKELY WITH TIME. BASED ON THERMAL PROFILES...HAVE OPTED TO THROW IN
MIX MENTION FOR THE DAY AS 1000-850 MB VALUES DROP TO NEAR OR BELOW
1300 M.
HAVE ONLY MADE MINOR TWEAKS TO POPS FROM CR INIT TO PLACE HIGHER
EMPHASIS ON PAST VS PRESENT WITH SLIGHTLY HIGHER POPS. WHILE AN
OUTLIER...IF ECMWF SOLUTION OF UPPER LOW EVENTUALLY WORKING NORTH
TOWARDS THE AREA MON NGT INTO TUES NGT BODES TRUE...COULD BE RATHER
WET. ECMWF HAS BEEN VERY VARIABLE OF LATE...BUT NO WORSE THAN SOME
OF THE OTHERS LEADING TO AT LEAST CONSIDERATION OF THE SCENARIO.
REGARDLESS OF SOLUTIONS...NORMAL TO BELOW NORMAL TEMPS WILL BE IN
STORE SUNDAY AND BEYOND.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR LMZ043-046.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
627 AM CST THU NOV 24 2011
.AVIATION...
IFR TO LIFR CONDITIONS IN FOG AND LOW CLOUDS CONTINUE TO BLANKET
REGION EARLY THIS AM. CLOUD TRENDS THE MAIN CHALLENGE DURING
THE TAF CYCLE. IT APPEARS LITTLE CHG THROUGH MID MORNING WITH
WIDESPREAD IFR/LIFR CONDITIONS. HOWEVER BY LATE AM AND THIS AFTN
EXPECT INCREASED MIXING WITH GUSTY S/SW WINDS 15-25 KTS TO ERODE
LOW CLOUDS FROM WEST TO EAST RESULTING IN VFR CONDITIONS. THIS
SCENARIO SUPPORTED BY LAST SEVERAL RUNS OF RUC BACKUP FLIGHT RULES
PRODUCT AND HRRR LOW LEVEL CLOUD PRODUCT. TNGT WITH LOW LEVEL
MOISTURE STILL STREAMING TOWARD AREA AND LOW LEVEL INVERSION
STRENGTHENING BELIEVE STRATUS WITH IFR TO LIFR CONDITIONS WILL
REDEVELOP OVER AREAS THAT MANAGE TO CLEAR OUT TDY. THIS ALSO
DEPICTED BY RUC BACKUP MODEL FLIGHT RULES PRODUCT. MAY HAVE TO
WATCH FOR LLWS LATER TNGT AS SOME MODELS INCREASE WINDS TO AROUND
40 KTS IN 1500-2000 FT AGL... BUT BEING MARGINAL WITH POTENTIAL
GUSTY SLY SFC WINDS HAVE LEFT OUT MENTION.
&&
.PREV DISCUSSION... /ISSUED 335 AM CST THU NOV 24 2011/
SYNOPSIS...
SFC HIGH CENTERED OVER THE TN/OH VLYS EARLY THIS AM. MOIST LOW LEVEL
RETURN FLOW (SFC DEWPTS IN 40S) ON WESTERN AND SOUTHERN PERIPHERY OF
HIGH WITH 11-3.9 MICRON SATL IMAGERY SHOWING LARGE AREA OF LOW
CLOUDS WITHIN THIS MOIST AXIS. SOME FOG ALSO FOUND OVER REGION BUT
MAINLY LIGHT (2-6SM) DUE TO BLANKET OF LOW CLOUDS AND ALSO S/SW WINDS
OF 5-10 KTS KEEPING BL MIXED JUST ENOUGH.
SHORT TERM...TODAY AND TONIGHT...
ANOTHER DIFFICULT FCST REVOLVING AROUND SKY COVER TRENDS WITH HUGE IMPACT
ON TEMPS. COMPOUNDING DIFFICULTY IS THAT IT/S HARD TO FIND MODEL DOING
WELL IN CAPTURING COVERAGE/EXTENT OF LOW CLOUDS. OBSERVED SOUNDINGS
SHOW MOISTURE TO BE VERY SHALLOW ON THE ORDER OF 20 MB OR SO IN DEPTH
BUT BELOW VERY STRONG LOW LEVEL INVERSION. IT IS EXPECTED THOUGH THAT
MIXING TO INCREASE TDY AIDED BY STRENGTHENING SFC PRESSURE GRADIENT
WITH DEVELOPING GUSTY S/SW WINDS. THIS SHOULD BE SUFFICIENT TO TAP LARGE
AMOUNTS OF DRY AIR NEAR BASE OF INVERSION TO BEGIN EROSION PROCESS/
CLEARING TREND LATER THIS AM THROUGH AFTN. HIGHEST CONFIDENCE OF SEEING
CLEARING TDY IS ACROSS W/SW SECTIONS BEING IN CLOSER PROXIMITY TO
BACK EDGE OF STRATUS. LOWEST CONFIDENCE OF ANY CLEARING OF IS ACROSS NW IL
COUNTIES WHERE MOIST LOW LEVEL PARCEL TRAJECTORIES ARE AIMED. THE
HRRR LOW CLOUD PRODUCT... WHICH DID REALLY WELL YSTDY WITH STRATUS...
SUPPORTS THIS IDEA OF BEST CLEARING POTENTIAL W/SW OF MISSISSIPPI RVR TDY
AND HAVE TAILORED FCST CLOSELY TOWARD THIS SCENARIO. OBVIOUSLY AS CLOUDS
GO TDY... SO GO TEMPS. LOOKING BACK YSTDY TO OUR WEST NOTICED THAT AREAS
KEPT STRATUS THROUGH 18Z BEFORE DECREASING SAW HIGHS GENERALLY IN RANGE
OF 47-55 DEGS WITH U50S NEAR KC METRO. WENT WITH THIS GENERAL RANGE FOR MOST
OF CWA BEING COOLEST NW IL... AND WARMEST SE IA INTO NORTHEAST MO WHERE HAVE
SOME U50S/NR 60 DEGS. OF COURSE IF STRATUS HOLDS AND WHERE THAT DOES
OCCUR WILL SEE TEMPS ONLY GO UP 3-5 DEGS FOR HIGHS GENERALLY MID 40S.
IF CLEARING BUSTS OPEN EARLIER THEN WITH GUSTY S/SW WINDS WOULD SEE MORE
AREAS NR 60 OR IN THE 60S FOR HIGHS AND POSSIBLY NEARING RECORDS. SHOULD THIS
OCCUR MOST LIKELY WRN/SRN CWA.
TNGT... WENT WITH GENERAL IDEA THAT ANY CLEARING TO FILL BACK IN WITH
STRATUS WITH MOIST LOW LEVEL SFC PARCEL TRAJECTORIES STILL AIMED AT REGION.
THIS ALSO SUPPORTED BY BACKUP RUC MODEL AVIATION FLIGHT CATEGORIES PRODUCT
WHICH SHOWS IFR CONDITIONS BLOSSOMING THROUGHOUT REGION. GIVEN THIS AND
SLY WINDS AROUND 10 KTS WITH SOME GUSTS STAYED AT OR ABOVE WARMEST GUIDANCE
FOR LOWS... WITH WIDESPREAD L/M 40S. SOME FOG POSSIBLE BUT MAINLY LIGHT
(2-6SM) DUE TO CLOUDS AND SOUTH WINDS AROUND 10 KTS WITH SOME GUSTS.
.05..
LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY...
FORECAST FOCUS ON RAIN FRIDAY NIGHT AND SATURDAY OTHERWISE MAINLY A
CHILLY BUT DRY PERIOD.
FRIDAY...EXPECTING A WARM DAY IN THE BRISK SOUTHERLY FLOW AS TROUGH
DIVES INTO THE NORTHERN ROCKIES AND ANOTHER LIFTS INTO THE SOUTHERN
ROCKIES. MAX TEMPS IN THE 60 TO 65 RANGE ROUGHLY SOUTH OF HIGHWAY 30
WITH 55 TO 60 TO THE NORTH. THESE TEMPS BASED ON INCREASING CLOUD
COVER AS THE DAY PROGRESSES. BUT IF THERE IS MORE SUNSHINE THEN
TEMPS MAY BE SOMEWHAT HIGHER. HOWEVER A BIG PROBLEM COULD BE STRATUS
FORMING UNDER THE STRENGTHENING INVERSION EARLY FRIDAY THAT IF
LINGERS TOO LONG WOULD PUT A BIG DENT INTO THE WARM TEMPS. BASED ON
THIS CURRENT FORECAST RECORD HIGHS ARE NOT IN JEOPARDY. SEE CLIMATE
SECTION BELOW. PREVIOUS SHIFT HAD REMOVED MENTION OF RAIN FOR FRIDAY
AND BASED ON LATEST DATA THIS STILL LOOKS GOOD. SHOULD HAVE SOUTH
WINDS GUSTING TO AROUND 30 MPH.
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE 00Z ECM HAS SLOWED THE
PHASING OF THE TWO STREAMS AND KEEPS MUCH OF THE CWA DRY FRIDAY
EVENING...AND IN FACT KEEPS OUR FAR EASTERN CWA TOTALLY DRY FRIDAY
NIGHT. OTHERWISE WILL GRADUALLY WORK THE LIKELY POPS EASTWARD AS
MOST OF THE OPERATIONAL MODELS PAINT A WET NIGHT. RAINY DAY ON
SATURDAY MOST OF THE CWA EXCEPT OUR WESTERN CWA WHERE WE WILL HAVE A
CHANCE. TIMING THE ENDING OF THE RAIN VARIES UPON THE MODELS AND
LATER SHIFTS MAY NEED TO ADJUST. WIDESPREAD 0.20 TO 0.40 INCH RAIN
AMOUNTS STILL APPEAR LIKELY. ANY RAIN THAT CHANGES TO SNOW SHOWERS
AT THE TAIL END OF THIS EVENT BY SATURDAY NIGHT LOOKS SHORT-LIVED
AND UNEVENTFUL AS OF NOW. BACK TO REALITY AS MUCH COLDER AIR RETURNS
ON SATURDAY WITH STRONG COLD ADVECTION. MAX TEMPS ONLY IN THE MID
40S TO LOWER 50S...ALONG WITH NORTHWEST WINDS GUSTING OVER 30 MPH
ADDING TO THE CHILL. A RATHER WET AND RAW DAY ON SATURDAY.
SUNDAY THROUGH WEDNESDAY...INTERESTING THAT THE PAST COUPLE OF RUNS
OF THE ECM SHOWED EITHER A PROGRESSIVE TROUGH MOVING ACROSS THE
EASTERN UNITED STATES EARLY NEXT WEEK...OR A CLOSED LOW FORMING WELL
TO OUR EAST. AMAZINGLY THE 00Z RUN NOW IS DEPICTING THE CLOSED LOW
FARTHER TO THE WEST FORMING IN THE GULF STATES AND MOVING INTO THE
OHIO VALLEY. THE PRECIPITATION JUST GRAZES OUR FAR SE CWA. THE
GFS/GEM INDICATE A DIGGING TROUGH IN THE EASTERN STATES KEEPING THE
PRECIPITATION WELL EAST OF THE DVN CWA. BASICALLY FOR THE PAST 7
DAYS THE GFS/ECM HAVE BEEN ERRATIC AND SHOWING A LOT OF FLIP-
FLOPPING. THEREFORE THE EXTENDED REMAINS LOW CONFIDENCE. OTHER THAN
A SLIGHT CHANCE OF SNOW SHOWERS EAST OF THE MS RIVER ON SUNDAY THE
EXTENDED INDICATES DRY AND CHILLY WEATHER FOR NOW.
IF THE ECM IS CORRECT THE RECORD COLD ARCTIC AIR THAT HAS BEEN
BUILDING IN ALASKA THE PAST SEVERAL WEEKS WILL BE GETTING CLOSER AND
CLOSER THE FIRST WEEK OF DECEMBER. FAIRBANKS HAS NOT BEEN ABOVE ZERO
FOR THE PAST 10 DAYS. THE ARCTIC OSCILLATION IS ALSO FORECAST TO
START GOING NEGATIVE DURING THAT TIME. THIS MAY ALSO INCREASE THE
POTENTIAL FOR A SNOWSTORM.
.HAASE..
CLIMATE...
RECORD HIGHS FOR NOVEMBER 24...
MOLINE.........66 IN 1966
CEDAR RAPIDS...63 IN 1931
DUBUQUE........63 IN 1931
BURLINGTON.....68 IN 1915
RECORD HIGHS FOR NOVEMBER 25...
MOLINE.........67 IN 1896
CEDAR RAPIDS...68 IN 1896
DUBUQUE........65 IN 1896
BURLINGTON.....68 IN 1915
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
639 AM EST THU NOV 24 2011
UPDATED AVIATION DISCUSSION FOR 12Z TAFS
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL RIDGE
ACROSS THE CNTRL CONUS. A SHORTWAVE TROUGH OFFSHORE FROM THE PAC NW
WILL HELP AMPLIFY A PROGRESSIVE MID LEVEL TROUGH THAT WILL MOVE INTO
THE PLAINS TONIGHT AND TO THE WRN GREAT LAKES BY LATE SAT. AT THE
SFC...SSW FLOW PREVAILED OVER THE REGION BTWN LOW PRES INTO SRN
MANITOBA AND A RIDGE OVER THE OH AND LOWER MS VALLEY. 11-3.9 IR LOOP
INDICATED LOW CLOUDS ALONG THE WI BORDER FROM IWD TO IMT AND OVER
MUCH OF THE EAST HALF OF THE CWA. OTHERWISE...WAA HIGH CLOUDS WERE
SPREADING FROM NRN MN INTO WRN UPPER MI.
&&
.DISCUSSION...
TODAY AND TONIGHT...VERY MILD AIR HAS SPREAD OVER THE COLDER AIR NEAR THE
SURFACE CREATING A STRONG INVERSION AS 00Z KGRB SOUNDING SHOWED 925
MB TEMP AT 9C. MAX TEMPS WILL DEPEND ON HOW QUICKLY ANY MORNING
FOG/STRATUS BURNS OFF AND THE MIXING DEPTH. EVEN WITH LATE NOV SUN
ANGLE AND A VERY STABLE SFC-900 MB LAYER...EXPECT ENOUGH MIXING FOR
TEMPS ABOVE CONS GUIDANCE VALUES...CLIMBING INTO THE UPPER 40S TO
AROUND 50. AREAS WITH DOWNSLOPE SW WINDS COULD SEE READINGS INTO AT
LEAST THE MID 50S. SOUTHWEST WINDS WILL HELP KEEP MIN TEMPS WELL
ABOVE NORMAL TONIGHT WITH READINGS ONLY DROPPING INT0 THE UPPER 30S
TO AROUND 40.
FRIDAY...INCREASING CLOUDS WILL LIMIT POTENTIAL FOR HIGHER TEMPS BUT
WITH THE MILD AIRMASS IN PLACE TEMPS SHOULD STILL CLIMB INTO THE MID
AND UPPER 40S.
LATE FRIDAY NIGHT INTO SATURDAY...THE GFS/ECMWF WERE IN REASONABLE
AGREEMENT WITH THE PROGRESSIVE MID LEVEL TROUGH AND THE SFC LOW
DEVELOPING OVER THE PLAINS AND MOVING INTO TO NEAR IMT BY 18Z SAT.
STRONG MOISTURE INFLOW WITH PWAT VALUES TO 0.75 INCH AND 295K-300K
ISENTROPIC LIFT AHEAD OF THE LOW SUPPORT LIKELY RAIN CHANCES OVER THE
AREA...WITH THE HEAVIEST PCPN MAINLY IN THE MORNING. CAA IN THE WAKE
OF THE LOW ALONG WILL BRING A CHANGEOVER TO SNOW AND LAKE ENHANCED
SNOW LATE SAT NIGHT INTO SUN MORNING AS 850 MB TEMPS DROP TO AROUND
-8C.
MODEL DIFFERENCES EMERGE THAT IMPACT THE SNOWFALL POTENTIAL OVER WRN
UPPER MI. THE GFS CLOSES OFF A MID LEVEL LOW WHICH KEEPS THE DEEPER
MOISTURE AND LIFT ALONG WITH STRONGER CYCLONIC CIRCULATION INTO THE
WRN CWA. THE ECMWF AND CANADIAN GLOBAL GEM WITH A MORE PROGRESSIVE
MID LEVEL TROUGH WOULD BRING THE DRIER AIR IN FASTER WITH REDUCED
CHANCES FOR ACCUMULATING SNOW. UNTIL THE MODELS COME INTO BETTER
AGREEMENT A COMPROMISE WAS USED WHICH SUGGEST THE POTENTIAL FOR
SEVERAL INCHES OF SNOW OVER THE WEST. WITH ONLY MARGINALLY COLD AIR
INTO THE REGION...ANY ACCUMULATING SNOW WILL DIMINISH RAPIDLY AS THE
DEEPER MOISTURE AND WEAK LIFT MOVE OFF TO THE EAST SUNDAY.
MONDAY THROUGH WED...THE GFS...ECMWF AND MAJORITY OF ENSEMBLE
MEMBERS NOW SUGGEST THAT THE NRN STREAM WILL PREVAIL ACROSS THE NRN
LAKES AND THAT EITHER NO CUTOFF WILL DEVELOP TO THE SOUTH OR IT WILL
REMAIN FAR ENOUGH AWAY TO HAVE LITTLE IMPACT ON THE WEATHER OVER THE
REGION. SFC AND MID LEVEL RIDGING INTO THE AREA MON ALONG WITH
SIGNIFICANT WAA WILL KEEP THE AREA DRY WITH SW WINDS AND TEMPS
CLIMBING TO NEAR 40F. LOW CONFIDENCE BY TUE/WED BUT MODELS SUGGEST
POTENTIAL FOR A A COLD FROPA BEHIND A NRN STREAM SHRTWV COULD BRING
ENOUGH COLD AIR INTO THE AREA FOR SOME LAKE EFFECT SNOW.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
LOW CLOUDS CONTINUE TO MAKE FOR A DIFFICULT FORECAST FOR SOME OF THE
TAF SITES. AREA OF LOW CLOUDS OVER NORTHERN WI SPREAD INTO KSAW
OVERNIGHT. EXPECT THE LIFR CONDITIONS TO CONTINUE THROUGH MUCH OF
THE MORNING BEFORE MIXING BREAKS UP THE CLOUDS. WITH SOUTHWEST FLOW
CONTINUING TONIGHT...EXPECT LOW CLOUDS TO ONCE AGAIN REDEVELOP AND
PUSH INTO THE TAF SITES. UNCERTAIN ON COVERAGE AND NORTHWARD
EXTENT...SO HAVE ONLY WENT MVFR/IFR CIGS AT KSAW/KIWD. LLWS IS
EXPECTED AGAIN TONIGHT AHEAD OF AN APPROACHING SURFACE TROUGH ON
FRIDAY.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
SOUTHWESTERLY WINDS WILL CONTINUE TODAY INTO TONIGHT...ALTHOUGH A
STRENGTHENING INVERSION WILL LIKELY KEEP WINDS FROM GUSTING OVER
30KTS. ON FRIDAY...A WEAK SFC TROUGH WILL STALL OVER LK SUPERIOR AND
DIMINISH THE WINDS BELOW 20KTS. A LOW IS THEN EXPECTED TO MOVE OUT
OF THE CENTRAL PLAINS AND FOLLOW THE TROUGH OVER EASTERN LAKE
SUPERIOR ON SATURDAY. AS THE LOW SHIFTS NORTHEAST ON SATURDAY
NIGHT...NORTH TO NORTHWEST GALE FORCE GUSTS TO 35KTS ARE POSSIBLE
OVER CENTRAL/EASTERN LAKE SUPERIOR. HIGH PRESSURE RIDGE WILL BUILD
OVER LAKE SUPERIOR ON SUNDAY NIGHT AND LEAD TO DECREASING
WINDS...BEFORE THEY PICK UP AGAIN OUT OF THE SOUTHWEST ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
611 AM EST THU NOV 24 2011
LATEST UPDATE...AVIATION...
.SYNOPSIS...(400 AM EST THU NOV 24 2011)
THANKSGIVING DAY WILL SEE SOME CLOUDS MOVE IN WITH HIGHS IN THE
UPPER 40S. NO RAIN IS EXPECTED UNTIL THE WEEKEND WHEN A COLD FRONT
MOVES THROUGH. RAIN SHOWERS COULD MIX WITH WET SNOW BY SUNDAY NIGHT
AS COLDER AIR MOVES IN BEHIND THE COLD FRONT.
&&
.SHORT TERM...(400 AM EST THU NOV 24 2011)
(TODAY THROUGH SATURDAY)
FORECAST PROBLEMS IN THE NEAR TERM INCLUDE LOW CLOUDS AND POTENTIAL
IMPACT ON MAX TEMPS TODAY AND TIMING IN THE RAIN ON SATURDAY.
LOWERED MAXES FROM THE LOWER 50S TO UPPER 40S FOR TODAY AS SATELLITE
AND OBS SHOW AREA OF LOW STRATUS MOVING INTO THE WESTERN FORECAST
AREA ATTM. MAX TEMPS WERE HELD TO THE LOWER 40S ACROSS IOWA ON
WEDNESDAY AFTERNOON UNDER THESE CLOUDS.
00Z NAM RH PROFILES SHOW INVERSION SLOWLY LOWERING AND SUGGESTS
CLOUDS COULD BREAK UP THIS AFTERNOON...BUT LATEST RUC IS MORE
PESSIMISTIC AND WOULD MEAN A CLOUDY DAY AND MAXES PROBABLY HELD IN
THE MID 40S. STRATUS MAY HANG ON EVEN INTO TONIGHT AND POSSIBLE
FRIDAY MORNING BEFORE INCREASING WINDS AND MIXING SCOUR THEM OUT.
KEPT CHANCE POPS UP NORTH FOR FRIDAY NIGHT AS SOME ISENTROPIC ASCENT
AND MID LEVEL MOISTURE IS AVAILABLE. THE STEADIER RAIN SHOULD
HOLD OFF UNTIL AFTER 12Z SATURDAY AND POSSIBLY UNTIL 00Z SUNDAY IF
THE SLOWER EURO SOLUTION PANS OUT...AS DIGGING SHORTWAVE TROUGH
APPROACHES AND COUPLED JET ALONG WITH DEEP MOISTURE MOVES IN.
&&
.LONG TERM...(400 AM EST THU NOV 24 2011)
(SATURDAY NIGHT THROUGH WEDNESDAY)
THE MID RANGE MODELS CONTINUE TO SHOW DIFFERENCES IN THE LONG TERM.
THERE IS GOOD AGREEMENT ON THE SYSTEM SATURDAY NIGHT THROUGH SUNDAY
NIGHT. HOWEVER... CONFIDENCE IS LOWER FOR THE POTENTIAL
PRECIPITATION WITH A SYSTEM MONDAY NIGHT INTO WEDNESDAY. IN FACT...
THE ECMWF SHOWS THE WEATHER ASSOCIATED WITH A CUT OFF LOW SWEEPING
BY TO THE SOUTHEAST OF THE AREA. MEANWHILE... THE GFS HAS NO CUTOFF
LOW AND MOVES A WEAK CANADIAN WAVE BY TO THE NORTH. THEREFORE...
CONFIDENCE AND THE POPS ARE LOWER AFTER MONDAY AND SOME PERIODS HAVE
BEEN DRIED OUT. THE PRECIPITATION... IF IT OCCURS... COULD BE
RAIN... SNOW OR A RAIN/SNOW MIX.
TEMPERATURES WILL BE A LITTLE ABOVE NORMAL THROUGH THE WEEKEND. THEY
WILL BE AROUND NORMAL NEXT WEEK. NORMAL HIGHS THIS TIME OF YEAR ARE
AROUND 40 DEGREES AND NORMAL LOWS ARE IN THE UPPER 20S.
&&
.AVIATION...(611 AM EST THU NOV 24 2011)
IFR AND LIFR CONDITIONS EXPECTED TO CONTINUE PAST 18Z AS STRATUS
DECK HAS MOVED IN AND WILL BE SLOW TO LEAVE. THE LAYER OF CLOUDS
WILL HAVE BASES FROM 200 TO 800 FEET AGL AND TOPS LOWER THAN 200
FEET AGL. WILL HAVE SOME CLEARING AFTER 18Z...BUT THIS IS
QUESTIONABLE GIVEN THE PERSISTENCE OF THESE CLOUDS YESTERDAY ACROSS
AREAS WEST OF LOWER MICHIGAN.
&&
.MARINE...(400 AM EST THU NOV 24 2011)
ISSUED A SMALL CRAFT ADVISORY FOR TODAY THROUGH FRIDAY NIGHT AS A
TIGHTENING PRESSURE GRADIENT WILL BRING WEST TO SOUTHWEST WINDS
GUSTING TO 25 KNOTS AND WAVES BUILDING ABOVE FOUR FEET.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY THROUGH FRIDAY NIGHT.
&&
$$
SYNOPSIS: OSTUNO
SHORT TERM: OSTUNO
LONG TERM: 63
AVIATION: OSTUNO
MARINE: OSTUNO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
547 AM EST THU NOV 24 2011
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL RIDGE
ACROSS THE CNTRL CONUS. A SHORTWAVE TROUGH OFFSHORE FROM THE PAC NW
WILL HELP AMPLIFY A PROGRESSIVE MID LEVEL TROUGH THAT WILL MOVE INTO
THE PLAINS TONIGHT AND TO THE WRN GREAT LAKES BY LATE SAT. AT THE
SFC...SSW FLOW PREVAILED OVER THE REGION BTWN LOW PRES INTO SRN
MANITOBA AND A RIDGE OVER THE OH AND LOWER MS VALLEY. 11-3.9 IR LOOP
INDICATED LOW CLOUDS ALONG THE WI BORDER FROM IWD TO IMT AND OVER
MUCH OF THE EAST HALF OF THE CWA. OTHERWISE...WAA HIGH CLOUDS WERE
SPREADING FROM NRN MN INTO WRN UPPER MI.
&&
.DISCUSSION...
TODAY AND TONIGHT...VERY MILD AIR HAS SPREAD OVER THE COLDER AIR NEAR THE
SURFACE CREATING A STRONG INVERSION AS 00Z KGRB SOUNDING SHOWED 925
MB TEMP AT 9C. MAX TEMPS WILL DEPEND ON HOW QUICKLY ANY MORNING
FOG/STRATUS BURNS OFF AND THE MIXING DEPTH. EVEN WITH LATE NOV SUN
ANGLE AND A VERY STABLE SFC-900 MB LAYER...EXPECT ENOUGH MIXING FOR
TEMPS ABOVE CONS GUIDANCE VALUES...CLIMBING INTO THE UPPER 40S TO
AROUND 50. AREAS WITH DOWNSLOPE SW WINDS COULD SEE READINGS INTO AT
LEAST THE MID 50S. SOUTHWEST WINDS WILL HELP KEEP MIN TEMPS WELL
ABOVE NORMAL TONIGHT WITH READINGS ONLY DROPPING INT0 THE UPPER 30S
TO AROUND 40.
FRIDAY...INCREASING CLOUDS WILL LIMIT POTENTIAL FOR HIGHER TEMPS BUT
WITH THE MILD AIRMASS IN PLACE TEMPS SHOULD STILL CLIMB INTO THE MID
AND UPPER 40S.
LATE FRIDAY NIGHT INTO SATURDAY...THE GFS/ECMWF WERE IN REASONABLE
AGREEMENT WITH THE PROGRESSIVE MID LEVEL TROUGH AND THE SFC LOW
DEVELOPING OVER THE PLAINS AND MOVING INTO TO NEAR IMT BY 18Z SAT.
STRONG MOISTURE INFLOW WITH PWAT VALUES TO 0.75 INCH AND 295K-300K
ISENTROPIC LIFT AHEAD OF THE LOW SUPPORT LIKELY RAIN CHANCES OVER THE
AREA...WITH THE HEAVIEST PCPN MAINLY IN THE MORNING. CAA IN THE WAKE
OF THE LOW ALONG WILL BRING A CHANGEOVER TO SNOW AND LAKE ENHANCED
SNOW LATE SAT NIGHT INTO SUN MORNING AS 850 MB TEMPS DROP TO AROUND
-8C.
MODEL DIFFERENCES EMERGE THAT IMPACT THE SNOWFALL POTENTIAL OVER WRN
UPPER MI. THE GFS CLOSES OFF A MID LEVEL LOW WHICH KEEPS THE DEEPER
MOISTURE AND LIFT ALONG WITH STRONGER CYCLONIC CIRCULATION INTO THE
WRN CWA. THE ECMWF AND CANADIAN GLOBAL GEM WITH A MORE PROGRESSIVE
MID LEVEL TROUGH WOULD BRING THE DRIER AIR IN FASTER WITH REDUCED
CHANCES FOR ACCUMULATING SNOW. UNTIL THE MODELS COME INTO BETTER
AGREEMENT A COMPROMISE WAS USED WHICH SUGGEST THE POTENTIAL FOR
SEVERAL INCHES OF SNOW OVER THE WEST. WITH ONLY MARGINALLY COLD AIR
INTO THE REGION...ANY ACCUMULATING SNOW WILL DIMINISH RAPIDLY AS THE
DEEPER MOISTURE AND WEAK LIFT MOVE OFF TO THE EAST SUNDAY.
MONDAY THROUGH WED...THE GFS...ECMWF AND MAJORITY OF ENSEMBLE
MEMBERS NOW SUGGEST THAT THE NRN STREAM WILL PREVAIL ACROSS THE NRN
LAKES AND THAT EITHER NO CUTOFF WILL DEVELOP TO THE SOUTH OR IT WILL
REMAIN FAR ENOUGH AWAY TO HAVE LITTLE IMPACT ON THE WEATHER OVER THE
REGION. SFC AND MID LEVEL RIDGING INTO THE AREA MON ALONG WITH
SIGNIFICANT WAA WILL KEEP THE AREA DRY WITH SW WINDS AND TEMPS
CLIMBING TO NEAR 40F. LOW CONFIDENCE BY TUE/WED BUT MODELS SUGGEST
POTENTIAL FOR A A COLD FROPA BEHIND A NRN STREAM SHRTWV COULD BRING
ENOUGH COLD AIR INTO THE AREA FOR SOME LAKE EFFECT SNOW.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
LOOKING AT IR SATELLITE IMAGERY...THE COMBINATION OF DOWNSLOPE SW
WINDS AOA 20 KTS WITHIN BOUNDARY LYR AND HIGHER DEWPOINT DEPRESSIONS
MAKES STRATUS/FOG DEVELOPMENT LESS LIKELY AT KIWD AND KCMX
OVERNIGHT. THUS HAVE DECIDED TO GO WITH CLEAR SKIES AND VFR
CONDITIONS AT KIWD AND KCMX. SLOW ADVANCE OF STRATUS/FOG FROM NRN WI
WILL LIKELY REACH INTO KSAW BY 08Z BUT MIXING FROM SW WINDS SHOULD
SCOUR OUT STRATUS/FOG WITHIN A FEW HRS AFTER SUNRISE. MAINTAINED
LLWS IN ALL SITES OVERNIGHT WITH STRONG WRLY WINDS JUST OFF THE
SFC.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
SOUTHWESTERLY WINDS WILL CONTINUE TODAY INTO TONIGHT...ALTHOUGH A
STRENGTHENING INVERSION WILL LIKELY KEEP WINDS FROM GUSTING OVER
30KTS. ON FRIDAY...A WEAK SFC TROUGH WILL STALL OVER LK SUPERIOR AND
DIMINISH THE WINDS BELOW 20KTS. A LOW IS THEN EXPECTED TO MOVE OUT
OF THE CENTRAL PLAINS AND FOLLOW THE TROUGH OVER EASTERN LAKE
SUPERIOR ON SATURDAY. AS THE LOW SHIFTS NORTHEAST ON SATURDAY
NIGHT...NORTH TO NORTHWEST GALE FORCE GUSTS TO 35KTS ARE POSSIBLE
OVER CENTRAL/EASTERN LAKE SUPERIOR. HIGH PRESSURE RIDGE WILL BUILD
OVER LAKE SUPERIOR ON SUNDAY NIGHT AND LEAD TO DECREASING
WINDS...BEFORE THEY PICK UP AGAIN OUT OF THE SOUTHWEST ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...VOSS
MARINE...SRF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1035 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE A DRY STRETCH OF WEATHER THROUGH
SATURDAY ALONG WITH MODERATING TEMPERATURES. BY SUNDAY, A COLD
FRONT WILL BRING SCATTERED SHOWERS TO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE. TOUCHY CLOUD FORECAST TODAY...WITH LOW LEVEL CLOUDS
IN WESTERN NY AND ALSO MOHAWK VALLEY AND PARTS OF THE
CATSKILLS...VERY POORLY RESOLVED BY THE MODELS. HIGH RES MODELS
HAVE STARTED TO CATCH UP...THOUGH RIC MODEL OVERCOMPENSATING.
BASED ON HR RR DEPICTION OF CLOUD COVER...I BRING MORE CLOUDS BACK
GENERALLY ALONG AND NORTH OF I-90 CORRIDOR THIS AFTERNOON AND
PARTS OF WESTERN FINGER LAKES REGION...WHERE INVERSION IS MORE
RETAINED. DRY POCKET WITH SUNSHINE IN BETWEEN...KEEPS THINGS MIXED
ENOUGH WITH DISSIPATION OF INVERSION...TO PREVENT CLOUDS FROM CREEPING
EASTWARD. TEMPERATURES ALSO ADJUSTED SLIGHTLY LOWER WHERE MORE
CLOUDS ARE NOW EXPECTED.
LOOKING INTO TONIGHT...EXPECTING CLOUDS TO CONTINUE TO BE STUCK
OVER PARTS OF WESTERN MOHAWK VALLEY. MODELS CURRENTLY NOT
SUGGESTING ENOUGH LOW LEVEL MOISTURE FOR CLOUDS OVER REMAINDER OF
AREA...THOUGH THIS WILL HAVE TO MONITORED SINCE THEY PERFORMED
POORLY UPSTREAM FOR LAST NIGHT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
FRIDAY THROUGH SATURDAY...A BROAD UPPER LEVEL RIDGE WILL BUILD
OVER THE NORTHEAST AS AFC HIGH PRES IN THE MID ATLANTIC PROVIDES A
MODERATING SOUTHWEST FLOW. LATE FRIDAY NIGHT INTO SATURDAY, LOW
PRES OVER THE UPPER GREAT LAKES WITH WARM FRONT STRETCHING ACROSS
NEARBY SOUTHERN ONTARIO WILL PRODUCE MORE CLOUD COVER. ANY THREAT
OF PRECIP WILL REMAIN WELL NORTH OF REGION JUST SOME MID CLOUDS
DUE TO MID LEVEL WARMING BUT STILL PARTLY CLOUDY.
MAX TEMPS FRIDAY/SATURDAY WILL GENERALLY RANGE IN THE MID TO UPPER
50S WITH THE NORMALLY WARMER AREAS NEAR 60.
SATURDAY NIGHT...AN APPROACHING COLD FRONT FROM THE WESTERN LAKES
WILL BE IN THE VICINITY OF EXTREME WESTERN NEW YORK BY 12Z
SUNDAY. WILL CONTINUE WITH SLIGHT CHC POPS FOR RAIN SHOWERS LATE
SATURDAY NIGHT OVER THE FINGER LAKES REGION AND CENTRAL SOUTHERN
TIER.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MAIN FOCUS IN THE MEDIUM RNG IS THE AMPLIFYING TROF WHICH IS
FORECAST TO MOV INTO THE CNTRL AND THE ERN U.S. EARLY NXT WEEK.
THERE ARE SIG DIFFS IN THE MDLS W/RESPECT TO TIMING...PCPN
AMTS...AND NRN/SRN STREAM INTERACTION. GFS PAINTS A POTNL FLOOD
SCENARIO WITH SRN PORTION OF THE TROF CUTTING OFF THEN LIFTING
NEWD...WITH +RA ACRS THE FSCT AREA SUN NGT INTO MONDAY ALONG AN
INVERTED TROF. THE EURO SHOWS LESS INTERACTION BETWEEN NRN AND SRN
STREAMS...BUT STILL SHOWS RAIN WORKING NWD INTO THE RGN LATE MON
NGT INTO TUE...BUT THE HEAVIEST PCPN IS SHUNTED OFF TO OUR
SOUTHEAST. GIVEN THESE DIFFS...WE LEANED HEAVILY ON HPC GUIDANCE
FOR THE MEDIUM RNG..WHICH PAINTS AN UNSETTLED PICTURE INTO
MIDWEEK.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
DENSE FOG AT ELM...AND PTCHY IFR/MVFR CIGS ELSEWHERE THIS MRNG.
DRY AIR UNDER HIPRES WILL HELP MIX OUT THE LL MOISTURE AND BRING
ALL CIGS AND VSBY TO VFR. MAINLY CLR CONDS TODAY IN TNGT UNDER THE
HI. SOME MVFR FOG PSBL AGAIN TNGT AT ELM...BUT STRONGER LL WINDS
SHD KEEP IFR CIGS AND VSBY FROM OCCURRING.
OUTLOOK...
THU THROUGH SAT...VFR.
SUN NGT/MON...IFR/MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...MDP
SHORT TERM...RRM
LONG TERM...
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1020 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE REGION TODAY...AND
REMAIN OVER THE NORTHEAST THROUGH THE UPCOMING WEEKEND. A FRONTAL
BOUNDARY APPROACHES THE AREA LATE SUNDAY INTO MONDAY. A LOW MOVING
ALONG THIS FRONT WILL KEEP PRECIPITATION OVER THE NORTH COUNTRY
INTO TUESDAY BEFORE HIGH PRESSURE BUILDS INTO THE AREA FOR MIDWEEK
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 1009 AM EST THURSDAY...STRATUS DECK WILL LIKELY HOLD FIRM
TODAY GIVEN STRONG INVERSION 950-850MB LAYER PER 12Z ALB SOUNDING
AND AVAILABLE RUC FCST SOUNDINGS. THIS WILL LIKELY ALSO HOLD
TEMPERATURES SLIGHTLY BELOW MOS VALUES. WINDS WILL GRADUALLY
BECOME S-SW 5-10 MPH...MAINLY WEST OF THE GREEN MTNS...WITH WINDS
MORE LIGHT/VARIABLE EAST OF THE GREENS. COULD BE A BRIEF FLURRY OR
TWO...BUT SHALLOW NATURE OF CLOUD DECK AND BUILDING HEIGHTS ALOFT
WILL GENERALLY PRECLUDE ANY PCPN TODAY OR TONIGHT.
FOR TONIGHT...CLOUDS REMAIN TRICKY. LIKELY TO SEE A SLOWER
CLEARING TREND...BUT STRENGTHENING S-SW FLOW OVERNIGHT SHOULD HELP
TO EVENTUALLY ADVECT THE STRATUS AWAY FROM SW-NE. WINDS OVERNIGHT
REMAIN 5-10 MPH RANGE WITH PREVAILING GRADIENT FLOW...ESPECIALLY
IN THE WIDER VALLEY LOCATIONS. WINDS WILL APPROACH 20 KTS ON LAKE
CHAMPLAIN AFTER MIDNIGHT. CLOUDS AND WIND WILL HELP HOLD LOW
TEMPERATURES MAINLY IN THE 30S...EXCEPT LOCALLY LOW-MID 20S FOR
THE FAR NERN PORTIONS OF VERMONT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
AS OF 227 AM EST THURSDAY...HIGH PRESSURE SOUTH OF THE CWA ON
FRIDAY...PUSHING OFFSHORE DURING THE DAY SATURDAY. W/ CWA EXPECTED
TO BE UNDER WSW FLOW...WAA WILL BRING IN INCR HIGH TEMPS OVER THE
TWO-DAY PERIOD. W/ 850/925 TEMPS NEAR +4C TO +8C BOTH DAYS HIGHS
NEAR 50F ARE NOT OUT OF THE QUESTION. HAVE GONE A FEW DEGREES ABV
NORMALS/MDL GUIDANCE AS DO NOT SEE ENOUGH COOLING OVERNGT THAT THE
NUMBERS SHOW WITH CWA STILL UNDER WAA FROM THE WSW. MDLS DO HINT AT
THE POSSIBILITY OF INCR CLDS DURING THE DAY SATURDAY FOR N
ZONES/ST LAW VALLEY DUE TO WK WARM FRNT THAT MAY ULTIMATELY
INHIBIT SUNSHINE THERE. OTHER WX ISSUE TO BE OF CONCERN WILL BE
GUST POTENTIAL OVER N NY DUE TO MID LEVEL JET NEAR CANADIAN
BORDER. BUFKIT SUGGEST GUSTS TO NEAR 30 MPH IF MIXING OCCURS SO
WILL PUT IN MENTION...OTHERWISE...CWA WILL SEE FAIRLY NICE 2-DAY
STRETCH OF WX FOR LATE NOVEMBER.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 405 AM EST THURSDAY...DRY CONDITIONS WILL CONTINUE SATURDAY
NIGHT INTO EARLY SUNDAY AS WE REMAIN UNDER INFLUENCE OF HIGH
PRESSURE...WHICH WILL BE MOVING FURTHER OFFSHORE. CHANCES FOR RAIN
SHOWERS INCREASE DURING THE DAY ON SUNDAY WITH LOW PRESSURE LIFTING
NORTH OF THE REGION AND ASSOCIATED COLD FRONT APPROACHING FROM THE
GREAT LAKES/OHIO VALLEY. BUT ECMWF AND GFS CONTINUE TO OFFER
SIGNIFICANTLY DIFFERENT SOLUTIONS FOR THE REMAINDER OF THE PERIOD.
GFS DEPICTING FULL LATITUDE TROUGH...WITH SURFACE COLD FRONT MOVING
SLOWLY ACROSS THE NORTHEAST. THIS SCENARIO WOULD RESULT IN SOME
SIGNIFICANT RAINFALL ACROSS THE AREA SUNDAY NIGHT INTO MONDAY WITH
GOOD FEED OF MOISTURE OFF THE ATLANTIC. THIS SYSTEM THEN GETS PUSHED
TO THE EAST BY SERIES OF POTENT NORTHERN STREAM SHORTWAVES WHICH
WOULD TRAVERSE THE REGION TUESDAY THROUGH THURSDAY...ACCOMPANIED BY
SCATTERED RAIN/SNOW SHOWERS. ECMWF BRINGS INITIAL SHORTWAVE AND
COLD FRONT ACROSS THE AREA BY MONDAY. SOUTHERN STREAM SHORTWAVE
THEN LIFTS NORTHEAST FROM THE MISSISSIPPI VALLEY BRINGING
POSSIBILITY OF MORE WIDESPREAD RAINFALL FOR TUESDAY INTO WEDNESDAY.
WITH SUCH A WIDE DISPARITY BETWEEN THE MODELS...FORECASTER
CONFIDENCE FOR MUCH OF THE EXTENDED PERIOD IS RATHER LOW. BEST
CHANCE FOR RAINFALL ON ALL OF THE MODELS APPEARS TO BE SUNDAY
NIGHT. FOR THE REST OF THE PERIOD...HAVE GONE WITH FORECAST OF MAINLY
CLOUDY WITH A CHANCE OF SHOWERS. PRECIPITATION TYPE RAIN THROUGH
MONDAY...BUT SOME SNOW SHOWERS POSSIBLE THEREAFTER OVER THE HIGHER
TERRAIN AS TEMPS RETURN TO MORE SEASONABLE LEVELS.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
THROUGH 12Z FRIDAY...ABUNDANT LOW-LEVEL MOISTURE WILL REMAIN OVER
THE REGION THIS MORNING WITH WIDESPREAD MVFR AND LOCAL IFR
CEILINGS. SLOW IMPROVEMENT AS HIGH PRESSURE BUILDS EAST FROM THE
OHIO VALLEY. BY 16Z ALL TAF SITES EXPECTED TO BE MVFR...WITH A
TREND TO VFR BY 19Z. EXCEPTIONS WILL BE KSLK/KMSS WHERE MVFR CIGS
MAY PERSIST THROUGH THE PERIOD. LIGHT AND VARIABLE WINDS WILL
BECOME SOUTH TO SOUTHWEST AT 5 TO 15 KTS TODAY.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...VFR CONDITIONS EXPECTED THROUGH
SUNDAY AS A RIDGE OF HIGH PRESSURE PASSES SOUTH OF THE REGION.
SHOWERS WITH MVFR/IFR CONDITIONS EXPECTED SUNDAY NIGHT AND MONDAY
AS A FRONTAL SYSTEM MOVES SLOWLY ACROSS THE AREA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JN
NEAR TERM...BANACOS
SHORT TERM...JN
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
640 AM EST THU NOV 24 2011
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE OVER THE LOWER OHIO VALLEY WILL
SLOWLY MOVE EAST THROUGH THE END OF THE WEEK. LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE PLAINS FRIDAY AND APPROACH THE GREAT
LAKES REGION SATURDAY. THE COLD FRONT FROM THE LOW PRESSURE IS
EXPECTED TO CROSS THE AREA SATURDAY NIGHT AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO SIGNIFICANT CHANGES TO THE FORECAST. LATEST IR SAT SHOWING
STRATUS CLOUDS ACROSS MUCH OF THE FORECAST AREA THIS MORNING. SOME
PEAKS OF SUN MAY BE POSSIBLE ACROSS A FEW LOCATIONS...BUT ANY
CLEAR SPOTS ARE FILLING IN SO WILL CONTINUE WITH A MOSTLY CLOUDY
TO CLOUDY FORECAST. PREVIOUS DISCUSSION BELOW.
HIGH PRESSURE TO THE SOUTH WILL KEEP THE AREA DRY TODAY...BUT THE
SIGNIFICANT WEATHER FEATURE OF TODAY WILL BE THE LOW CLOUDS THAT
HAVE BEEN ADVANCING EASTWARD ACROSS THE FORECAST AREA OVERNIGHT.
IR SAT SHOWING A LARGE AREA OF LOW STRATUS CLOUDS EXTENDING BACK
INTO IN AND IL THIS MORNING. THERE ARE SOME BREAKS IN THE CLOUDS
ACROSS THE WESTERN HALF OF THE AREA...BUT THINKING EVEN THIS AREA
WILL FILL IN BY AROUND OR JUST SUNRISE THIS MORNING.
MAV AND MET GUIDANCE WAY OFF THIS MORNING HANDLING THESE LOW
CLOUDS...SO ACTUALLY LEANED TOWARD THE HRRR MODEL FOR THIS
SITUATION. RECENT RUNS SINCE AROUND 04Z HAVE HANDLING THE LOW
CLOUDS FAIRLY WELL BRINGING THEM INTO THE AREA...AND THE HRRR
ACTUALLY PERSISTS THEM THROUGH MUCH OF THE DAY. LEANED TOWARD THIS
SOLUTION WITH A MAINLY CLOUDY FORECAST FOR TODAY ACROSS THE AREA
WITH SOME BREAKS POSSIBLE LATE AFTN/AROUND SUNSET THIS EVENING.
WITH THE ADDED CLOUDS IN THE FORECAST ALSO HAD TO ADJUST TEMPS
ACCORDINGLY. LOWERED TEMPS TO MAINLY UPPER 40S TO AROUND 50 FOR
TODAY WITH LITTLE RISE THROUGH THIS MORNING. MY CONCERN IS THAT IF
THE LOW STRATUS CLOUDS DO DOMINATE THROUGH THE ENTIRE AFTERNOON
THAT TEMPS TODAY MAY END UP EVEN COOLER THAN FORECAST. THEN RATHER
THAN A NORMAL DIURNAL CURVE TEMPS SIMPLY JUST CONTINUE TO SLOWLY
RISE THIS EVENING AND TONIGHT WITH WAA. FOR NOW WILL PROTECT
EITHER SOLUTION AND ALLOW THE FORECAST TEMPS TO BE A COMPROMISE
BETWEEN POSSIBLE SOLUTIONS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
HIGH PRESSURE TO THE SOUTH WILL REMAIN IN CONTROL TONIGHT THROUGH
FRIDAY NIGHT. GUIDANCE SUGGESTING THAT THE CLOUDS SHOULD DISSIPATE
TONIGHT ALLOWING FOR MOSTLY CLEAR TO PARTLY CLOUDY SKIES. WILL
LEAN TOWARD THAT TREND FOR NOW...BUT WILL BE SOMETHING WORTH
WATCHING THROUGH TODAY. TEMPS WILL BE TRICKY REGARDING THE
OVERNIGHT TRENDS...BUT OVERALL LOOKING FOR A MILDER NIGHT TONIGHT.
WITH INCREASING SOUTHERLY FLOW TEMPS WILL BE MILD ON FRIDAY AND
THEN EVEN A FEW BETTER ON SAT AHEAD OF AN APPROACHING COLD FRONT.
MADE LITTLE CHANGES TO TEMPS FRIDAY NIGHT THRU SAT NIGHT AS LIKED
LEANING ON THE WARMER SIDE OF CURRENT GUIDANCE. ALSO MADE LITTLE
CHANGES TO POPS THROUGH SAT NIGHT WITH LIKELY ALREADY MENTIONED IN
SOME AREAS. KEPT POPS RATHER HIGH IN THE LIKELY CATEGORY ON SUNDAY
WITH THE ECMWF A BIT SLOWER...BUT DID TREND TO LOWERING POPS
ACROSS THE WEST SUNDAY NIGHT. FOR SUNDAY AND SUNDAY NIGHT MADE
LITTLE CHANGES DUE TO TIMING ISSUES WITH THE FRONT...AS WELL AS
AIRMASS DIFFERENCES BETWEEN THE COOLER GFS AND WARMER ECMWF.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
LIKE YESTERDAY...MODELS CONTINUE TO HAVE SIGNIFICANT DIFFERENCES
DURING THE LONG TERM PERIOD. THE GFS CONTINUES TO BE COLDER AND
FASTER WITH THE MAIN FEATURES. HAVE NOT MADE MANY CHANGES TO THE
LONG TERM DURING THE PERIOD GIVEN THIS UNCERTAINTY. APPEARS THAT
NEARLY EVERY PERIOD WILL SEE AT LEAST A CHANCE FOR PRECIPITATION.
IT COULD BE COLD ENOUGH FOR MIXED SNOW AND RAIN BOTH TUESDAY AND
WEDNESDAY NIGHTS WITH LIQUID PRECIPITATION DURING THE DAY.
TEMPERATURES DURING THE PERIOD WILL AVERAGE WITHIN A DEGREE OR TWO
OF NORMAL.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
STRATUS DECK HAS MOVED OVER THE ENTIRE AREA OVERNIGHT. STILL A FEW
BREAKS FLOATING AROUND BUT THINK THE LOW CLOUDS WILL PERSIST MOST
OF THE DAY. BETTER MIXING IS LIKELY LATER THIS MORNING AND
AFTERNOON. THIS MAY CAUSE THE CIGS TO LIFT SLIGHTLY AND MAY ALSO
ALLOW FOR A FEW PEAKS OF THE SUN. FOR THE MOST PART THOUGH...CIGS
WILL REMAIN IFR TODAY. NOT REALLY SURE HOW FAST THE STRATUS DECK
WILL DISSIPATE AS THE MODELS HAVE NO FEEL FOR THE CURRENT
SITUATION. WILL TRY TO CLEAR THINGS FROM WEST TO EAST THIS EVENING
BUT WOULD NOT BE SURPRISED TO SEE THE CLOUDS PERSIST OVERNIGHT. SW
TO S FLOW EXPECTED THE ENTIRE PERIOD.
OUTLOOK...NON VFR SATURDAY NIGHT THROUGH SUNDAY NIGHT.
&&
.MARINE...
PERSIST WSW TO SW FLOW IS EXPECTED ON LAKE ERIE TILL A COLD FRONT
CROSSES THE LAKE SOMETIME SATURDAY NIGHT. WILL HOIST A SMALL CRAFT
FOR ABOUT THE EAST HALF OF THE AREA AS LOCAL SCHEMES AND MODELS ARE
GIVING 4 FOOT OR GREATER WAVES. THE FLOW WILL BECOME WESTERLY
BEHIND THE FRONT AND THEN REMAIN THAT WAY THROUGH THE END OF THE
PERIOD. LOT`S OF MODEL UNCERTAINTY DURING THE PERIOD SO THIS
FORECAST COULD BE IN FLUX...ESPECIALLY EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 3 AM EST
SATURDAY FOR LEZ147>149.
&&
$$
SYNOPSIS...ABE
NEAR TERM...ABE
SHORT TERM...ABE
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
629 AM EST THU NOV 24 2011
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE OVER THE LOWER OHIO VALLEY WILL
SLOWLY MOVE EAST THROUGH THE END OF THE WEEK. LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE PLAINS FRIDAY AND APPROACH THE GREAT
LAKES REGION SATURDAY. THE COLD FRONT FROM THE LOW PRESSURE IS
EXPECTED TO CROSS THE AREA SATURDAY NIGHT AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO SIGNIFICANT CHANGES TO THE FORECAST. LATEST IR SAT SHOWING
STRATUS CLOUDS ACROSS MUCH OF THE FORECAST AREA THIS MORNING. SOME
PEAKS OF SUN MAY BE POSSIBLE ACROSS A FEW LOCATIONS...BUT ANY
CLEAR SPOTS ARE FILLING IN SO WILL CONTINUE WITH A MOSTLY CLOUDY
TO CLOUDY FORECAST. PREVIOUS DISCUSSION BELOW.
HIGH PRESSURE TO THE SOUTH WILL KEEP THE AREA DRY TODAY...BUT THE
SIGNIFICANT WEATHER FEATURE OF TODAY WILL BE THE LOW CLOUDS THAT
HAVE BEEN ADVANCING EASTWARD ACROSS THE FORECAST AREA OVERNIGHT.
IR SAT SHOWING A LARGE AREA OF LOW STRATUS CLOUDS EXTENDING BACK
INTO IN AND IL THIS MORNING. THERE ARE SOME BREAKS IN THE CLOUDS
ACROSS THE WESTERN HALF OF THE AREA...BUT THINKING EVEN THIS AREA
WILL FILL IN BY AROUND OR JUST SUNRISE THIS MORNING.
MAV AND MET GUIDANCE WAY OFF THIS MORNING HANDLING THESE LOW
CLOUDS...SO ACTUALLY LEANED TOWARD THE HRRR MODEL FOR THIS
SITUATION. RECENT RUNS SINCE AROUND 04Z HAVE HANDLING THE LOW
CLOUDS FAIRLY WELL BRINGING THEM INTO THE AREA...AND THE HRRR
ACTUALLY PERSISTS THEM THROUGH MUCH OF THE DAY. LEANED TOWARD THIS
SOLUTION WITH A MAINLY CLOUDY FORECAST FOR TODAY ACROSS THE AREA
WITH SOME BREAKS POSSIBLE LATE AFTN/AROUND SUNSET THIS EVENING.
WITH THE ADDED CLOUDS IN THE FORECAST ALSO HAD TO ADJUST TEMPS
ACCORDINGLY. LOWERED TEMPS TO MAINLY UPPER 40S TO AROUND 50 FOR
TODAY WITH LITTLE RISE THROUGH THIS MORNING. MY CONCERN IS THAT IF
THE LOW STRATUS CLOUDS DO DOMINATE THROUGH THE ENTIRE AFTERNOON
THAT TEMPS TODAY MAY END UP EVEN COOLER THAN FORECAST. THEN RATHER
THAN A NORMAL DIURNAL CURVE TEMPS SIMPLY JUST CONTINUE TO SLOWLY
RISE THIS EVENING AND TONIGHT WITH WAA. FOR NOW WILL PROTECT
EITHER SOLUTION AND ALLOW THE FORECAST TEMPS TO BE A COMPROMISE
BETWEEN POSSIBLE SOLUTIONS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
HIGH PRESSURE TO THE SOUTH WILL REMAIN IN CONTROL TONIGHT THROUGH
FRIDAY NIGHT. GUIDANCE SUGGESTING THAT THE CLOUDS SHOULD DISSIPATE
TONIGHT ALLOWING FOR MOSTLY CLEAR TO PARTLY CLOUDY SKIES. WILL
LEAN TOWARD THAT TREND FOR NOW...BUT WILL BE SOMETHING WORTH
WATCHING THROUGH TODAY. TEMPS WILL BE TRICKY REGARDING THE
OVERNIGHT TRENDS...BUT OVERALL LOOKING FOR A MILDER NIGHT TONIGHT.
WITH INCREASING SOUTHERLY FLOW TEMPS WILL BE MILD ON FRIDAY AND
THEN EVEN A FEW BETTER ON SAT AHEAD OF AN APPROACHING COLD FRONT.
MADE LITTLE CHANGES TO TEMPS FRIDAY NIGHT THRU SAT NIGHT AS LIKED
LEANING ON THE WARMER SIDE OF CURRENT GUIDANCE. ALSO MADE LITTLE
CHANGES TO POPS THROUGH SAT NIGHT WITH LIKELY ALREADY MENTIONED IN
SOME AREAS. KEPT POPS RATHER HIGH IN THE LIKELY CATEGORY ON SUNDAY
WITH THE ECMWF A BIT SLOWER...BUT DID TREND TO LOWERING POPS
ACROSS THE WEST SUNDAY NIGHT. FOR SUNDAY AND SUNDAY NIGHT MADE
LITTLE CHANGES DUE TO TIMING ISSUES WITH THE FRONT...AS WELL AS
AIRMASS DIFFERENCES BETWEEN THE COOLER GFS AND WARMER ECMWF.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
LIKE YESTERDAY...MODELS CONTINUE TO HAVE SIGNIFICANT DIFFERENCES
DURING THE LONG TERM PERIOD. THE GFS CONTINUES TO BE COLDER AND
FASTER WITH THE MAIN FEATURES. HAVE NOT MADE MANY CHANGES TO THE
LONG TERM DURING THE PERIOD GIVEN THIS UNCERTAINTY. APPEARS THAT
NEARLY EVERY PERIOD WILL SEE AT LEAST A CHANCE FOR PRECIPITATION.
IT COULD BE COLD ENOUGH FOR MIXED SNOW AND RAIN BOTH TUESDAY AND
WEDNESDAY NIGHTS WITH LIQUID PRECIPITATION DURING THE DAY.
TEMPERATURES DURING THE PERIOD WILL AVERAGE WITHIN A DEGREE OR TWO
OF NORMAL.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
BAND OF STRATUS OVER WESTERN OHIO CONTINUING TO MOVE EAST AND
EXPAND. ANOTHER AREA OF STATUS MOVING RAPIDLY NORTHEAST FROM
CENTRAL INDIANA. THE MODELS DO NOT HAVE A HANDLE ON THIS WHICH IS
TYPICAL FOR THIS TIME OF YEAR WHEN LOW LEVEL MOISTURE GETS TRAPPED
BELOW THE INVERSION. MY FORECAST IS FOR THE STRATUS TO EVENTUALLY
COVER THE ENTIRE FORECAST AREA BY DAYBREAK THURSDAY. THE VISIBILITY
SHOULD BE MAINLY MVFR BUT COULD FLUCTUATE TO IFR AT TIMES. THE
CEILING SHOULD BE MAINLY IFR BUT COULD IMPROVE TO MVFR AT TIMES.
CONDITIONS SHOULD BE WORSE AT DAYBREAK. WITH THE TIME OF THE YEAR
THE CEILINGS MAY JUST GO BROKEN DURING THE AFTERNOON. NOT EXPECTING CLEAR
SKIES AS THE SURFACE RIDGE WILL BE EAST OF THE AREA...SO NO REAL
SUBSIDENCE. THURSDAY AFTERNOON CEILINGS MAY BE NEAR 1000 FEET WITH
THE VISIBILITY 6SM OR BETTER. CONDITIONS WILL BEGIN TO DETERIORATE AGAIN
THURSDAY NIGHT.
OUTLOOK...NON VFR SATURDAY NIGHT THROUGH SUNDAY NIGHT.
&&
.MARINE...
PERSIST WSW TO SW FLOW IS EXPECTED ON LAKE ERIE TILL A COLD FRONT
CROSSES THE LAKE SOMETIME SATURDAY NIGHT. WILL HOIST A SMALL CRAFT
FOR ABOUT THE EAST HALF OF THE AREA AS LOCAL SCHEMES AND MODELS ARE
GIVING 4 FOOT OR GREATER WAVES. THE FLOW WILL BECOME WESTERLY
BEHIND THE FRONT AND THEN REMAIN THAT WAY THROUGH THE END OF THE
PERIOD. LOT`S OF MODEL UNCERTAINTY DURING THE PERIOD SO THIS
FORECAST COULD BE IN FLUX...ESPECIALLY EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 3 AM EST
SATURDAY FOR LEZ147>149.
&&
$$
SYNOPSIS...ABE
NEAR TERM...ABE
SHORT TERM...ABE
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS NORMAN OK
545 AM CST THU NOV 24 2011
.AVIATION...
RECENT SATELLITE TREND SHOWS LOW CLOUDS AND DENSE FOG EXPANDING
MORE NORTHWARD WITH A SLOWER PROGRESSION TO THE WEST. THEREFORE...
WILL NOT MENTION IFR CEILINGS AT TAF SITES. COULD SEE SOME LIGHT
FOG ACROSS NORTH CENTRAL OKLAHOMA DURING THE NEXT FEW HOURS SO
WILL MENTION FOG IN PNC TAF. OTHERWISE VFR CONDITIONS EXPECTED AT
TAF SITES THROUGH AT LEAST 6Z FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 219 AM CST THU NOV 24 2011/
DISCUSSION...
CLOUD COVER...WITH CEILINGS AROUND 200 FT AND DENSE FOG...CONTINUES
TO SPREAD NORTH AND WEST THIS MORNING AROUND 15-20KT. THIS BRINGS
AREA OF LOW CLOUDS TO I-35 AROUND 11Z. HRRR WHICH IS USUALLY TOO
AGGRESSIVE...HAS LOW CEILINGS TO HWY 81 AND SOUTH OF I-40 BY 13Z.
WILL ADJUST SKY GRIDS TO REFLECT CLOUDS NEAR HWY 81 AND NORTH INTO
LINCOLN/PAYNE COUNTIES. HEATING AND INCREASING WINDS SHOULD ERODE
CLOUDS BY MID MORNING...ESPECIALLY WESTERN EDGE.
WINDS TONIGHT AND A MILD THANKSGIVING SHOULD KEEP THE FOG PONTENTIAL
LOW BUT SOME LOW CLOUDS MAY DEVELOP/MOVE INTO SOUTHERN PARTS OF
THE FA BY EARLY FRIDAY. ONLY MINOR ADJUSTMENTS WERE MADE TO
TIMING OF WX/POPS WITH FRIDAY/EARLY SATURDAY TROUGH. OVERNIGHT
LOWS FRIDAY NIGHT WILL BE A LITTLE TRICKY WITH PLACEMENT OF COLD
FRONT/CAA.
MOST OF THE RAIN SHOULD END BY MID MORNING SATURDAY. STRONG...GUSTY
NORTH WINDS SATURDAY SHOULD BE THE MAIN WEATHER STORY. RATHER DRY
AIRMASS BEHIND EARLY SATURDAY COLD FRONT WILL RESULT IN COLD
OVERNIGHT LOWS SUNDAY AND MONDAY. WITH SURFACE HIGH BUILDING SOUTH
INTO TEXAS...PER GFS...AFTERNOON TEMPERATURES USUALLY REBOUND QUICKER
THAN EXPECTED. ANOTHER COLD FRONT WILL PUSH ACROSS THE SOUTHERN
PLAINS LATE MONDAY INTO TUESDAY..BUT NO PRECIPITATION IS EXPECTED
WITH THE FRONTAL PASSAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 68 47 64 45 / 0 0 20 70
HOBART OK 67 48 64 40 / 0 0 40 50
WICHITA FALLS TX 68 48 65 46 / 0 0 40 70
GAGE OK 71 47 65 36 / 0 0 40 40
PONCA CITY OK 68 47 65 43 / 0 0 20 70
DURANT OK 68 48 65 51 / 0 0 30 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...DENSE FOG ADVISORY UNTIL 8 AM CST THIS MORNING FOR OKZ026-
030>032-040>043-046>048-050>052.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
536 AM CST THU NOV 24 2011
.SHORT TERM...TODAY THROUGH SATURDAY
352 AM CST THU NOV 24 2011
AT 3 AM...VLIFR/IFR CEILINGS WERE SEEN ACROSS ACROSS THE FORECAST
AREA. THESE CLOUDS HAVE BEEN SPREADING IN ALL DIRECTIONS
UNDERNEATH THE STRONG INVERSION LOCATED JUST ABOVE THE SURFACE.
OVERALL...THE HRRR HAS BEEN HANDLING THESE CLOUDS THE BEST...AND
IT SUGGESTS THAT THERE WILL BE GRADUAL DISSIPATION OF THESE CLOUDS
ON THE OUTER EDGES BETWEEN 16Z AND 18Z...AND THEN THIS PROGRESS A
BIT FASTER ACROSS THE REMAINING AREAS AS SOME DRIER AIR FROM ALOFT
MIXES DOWN.
DESPITE THE PERSISTENT CLOUDS THIS MORNING...THE COMBINATION OF
SOUTHERLY WINDS AND AFTERNOON SUNSHINE WILL HELP THE TEMPERATURES
CLIMB INTO THE 50S ACROSS THE FORECAST AREA. DUE TO THE SUNSHINE
ARRIVE EARLIER...THE WARMEST TEMPERATURES /UPPER 50S/ WILL LIKELY
FOUND IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA THIS AFTERNOON. WITH
NORTH CENTRAL WISCONSIN BEING ONE OF LAST TO LOSE THE CLOUDS...SO
THEY WILL LIKELY ONLY SEE TEMPERATURES CLIMBING TO AROUND 50 DEGREES.
FOR TONIGHT...BOTH THE 24.00Z NAM AND GFS SOUNDINGS SUGGEST THAT
THE CLOUDS ACROSS NORTHERN AND EASTERN WISCONSIN WILL ONCE AGAIN
SPREAD WESTWARD ACROSS THE FORECAST AREA. THE COMBINATION OF THESE
CLOUDS AND UNUSUALLY MOIST DEW POINTS WILL RESULT IN MINIMUM
TEMPERATURES ONLY FALLING INTO THE LOWER AND MID 40S. THIS IS
ABOUT 5 DEGREES WARMER THAN OUR NORMAL HIGH TEMPERATURE FOR THIS
DATE.
ON FRIDAY...THE LOW CLOUDS WILL GRADUALLY LIFT AND DISSIPATE
DURING THE DAY. HOWEVER AT THE SAME TIME...MID AND HIGH CLOUDS
WILL BE STREAMING INTO THE REGION AHEAD OF AN APPROACHING LONG
WAVE TROUGH. AS RESULT...NOT EXPECTING TOO MUCH SUNSHINE. DESPITE
THE LACK OF ABUNDANT SUNSHINE...SOUTHERLY WINDS WILL HELP WARM
TEMPERATURES INTO THE LOWER AND MID 50S.
ON FRIDAY NIGHT...THE MODELS CONTINUE TO INDICATE THAT MODERATE TO
STRONG MOISTURE TRANSPORT WILL MOVE INTO THE FORECAST AREA. THIS
WILL BE THE BEST ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA
DURING THE EVENING. DURING THE OVERNIGHT...MODERATE TO STRONG
ISENTROPIC LIFT AND FRONTOGENESIS WILL MOVE EAST INTO THE AREA.
AT THIS TIME...IT LOOKS LIKE THE BEST RAIN CHANCES WILL BE FROM
ALONG THE MISSISSIPPI RIVER EAST. DESPITE THE RAIN...THE SOUTHERLY
WINDS SHOULD HELP KEEP THE MINIMUM TEMPERATURES UNUSUALLY WARM FOR
THIS TIME OF YEAR. THEY WILL BE IN THE LOWER AND MID 40S ACROSS
SOUTHEAST MINNESOTA AND NORTHEAST IOWA...AND IN THE MID TO UPPER
40S FOR WESTERN WISCONSIN.
ON SATURDAY AND SATURDAY NIGHT...BOTH THE GFS AND ECMWF SHOW THAT
THERE WILL BE RAPID CYCLOGENESIS OCCURRING ACROSS MINNESOTA. THIS
IS IN RESPONSE TO SOME INTERACTION BETWEEN THE NORTHERN AND
SOUTHERN SHORT WAVE TROUGH EMBEDDED IN THE LONG WAVE TROUGH. THIS
RESULT IN THE TROPOPAUSE DESCENDING TO AROUND 500 MB...AND A RAPID
TIGHTENING OF THE SURFACE PRESSURE GRADIENT. SUSTAINED WINDS WILL
CLIMB INTO THE 15 TO 30 MPH RANGE...AND THE WIND GUSTS WILL RANGE
FROM 30 TO 40 MPH.
WITH STRONG COLD AIR ADVECTION BEING FOUND IN THE WAKE OF THE
COLD FRONT ON SATURDAY...TEMPERATURES SHOULD FALL STEADILY THROUGH
THE EARLY AFTERNOON AND THEN STABILIZE. THIS TREND WAS INTRODUCED
TO THE HOURLY TEMPERATURE GRIDS. IN ADDITION...GFS SOUNDINGS ARE
COLD ENOUGH FOR A SOME SNOW TO MIX IN. THIS WAS ALREADY IN THE
SOUTHEAST MINNESOTA AND NORTHEAST FORECAST GRIDS...BUT IT NOW
LOOKS LIKE WESTERN WISCONSIN MAY ALSO SEE SOME OF THIS SNOW
TOO...SO IT WAS ADDED TO THE GRIDS DURING THE MID AND LATE
AFTERNOON.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
352 AM CST THU NOV 24 2011
ON SATURDAY NIGHT...IT CONTINUE TO LOOK LIKE THERE WILL BE SOME
LINGERING LIGHT PRECIPITATION. AS RESULT...KEPT A CHANCE OF LIGHT
RAIN AND SNOW DURING THE EVENING...AND LIGHT SNOW OVERNIGHT. LIKE
THE PAST COUPLE OF DAYS...NOT EXPECTING TOO MUCH SNOW AT ALL FROM
THIS SYSTEM. IN ADDITION TO THE MIXED PRECIPITATION...THE STRONG
WINDS WILL LIKELY CONTINUE THROUGH THE NIGHT. SUSTAINED WINDS WILL
REMAIN IN THE 15 TO 30 MPH RANGE...AND THE WINDS WILL GUST UP TO
40 MPH.
BEYOND THIS TIME PERIOD...THERE CONTINUES TO BE VERY LITTLE
CONSISTENCY. HOWEVER WITH THIS SAID...I DO LIKE THAT THE MODELS
ARE STARTING TO BECOME MORE TRANSITORY WITH THEIR SYSTEM. THIS
MAKES SENSE WHEN LOOKING AT THE RATHER ACTIVE WAVE PATTERN FROM
AFRICA INTO THE WESTERN PACIFIC. THE GFS PATTERN ACTUALLY
RESEMBLES ONE OF THE PATTERNS THAT YOU WOULD TYPICALLY SEE DURING
A LA NINA. ANOTHER FEATURE THAT WE WILL HAVE TO PAY ATTENTION TO
AS WE HEAD INTO DECEMBER IS THE INTENSIFYING MADDEN JULIAN
OSCILLATION /WHICH HAS BEEN CONSISTENTLY FORECAST BY THE
BRAZILLIAN...ECMWF...JAPANESE...AND U.S. MODEL ENSEMBLES FOR THE
PAST WEEK/ THAT IS LOCATED OVER THE WESTERN INDIAN OCEAN. THIS WILL
LIKELY CAUSE SOME ISSUES WITH THE MODEL RUN TO RUN CONSISTENCY AT
LEAST INITIALLY. IN ADDITION...IT MAY BE ONE OF THE REASONS WHY THE
CLIMATE FORECAST SYSTEM VERSION 2 MODEL IS SUGGESTING THAT AT
LEAST THE FIRST HALF OF DECEMBER MAY END UP BEING WARMER THAN
NORMAL.
&&
.AVIATION...TODAY AND TONIGHT
536 AM CST THU NOV 24 2011
ANOTHER MORNING WITH A LOW STRATUS DECK OVER THE AREA AND THE MAIN
PROBLEM IS AGAIN WHEN WILL THE CLOUDS CLEAR OUT. CEILINGS ARE
EITHER IFR TO LOW MVFR IN THE DECK AND ARE EXPECTED TO REMAIN THAT
WAY UNTIL THE CLOUDS SCATTER OUT. THE 24.07Z HRRR LOW CLOUD
PRODUCT HAS A GOOD HANDLE ON WHERE THE CLOUDS ARE AND INDICATES A
SLOW EASTWARD DRIFT THROUGH THE MORNING AND THEN A PRETTY RAPID
EASTWARD PROGRESSION DURING THE LATE MORNING AND AFTERNOON AS THE
WINDS INCREASE AND THE SUN BEATS ON THE CLOUDS. THIS IS ALSO IN
VERY GOOD AGREEMENT WITH THE 24.06Z NAM BUFKIT SOUNDINGS. WILL
INDICATE THE CLOUDS SCATTERING OUT AT BOTH TAF SITES BY 18Z. THERE
IS SOME SIGNAL IN THE NAM...24.00Z GFS AND 24.03Z SREFS THAT THE
CLOUDS COULD ONCE AGAIN COME BACK LATE TONIGHT. EACH NIGHT THE
BACK EDGE OF THE CLOUDS HAS GOTTEN A LITTLE FARTHER TO THE EAST SO
THINKING THE BACK EDGE TONIGHT MAY BE JUST TO THE EAST OF KLSE.
ALSO...THE TIMING MAY NOT BE UNTIL VERY LATE IN THE FORECAST
PERIOD...SO A LOT OF UNCERTAINTY AND WILL NOT REINTRODUCE THE LOW
DECK AT THIS POINT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
251 AM CST THU NOV 24 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS TAUNTON MA
430 PM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE FROM THE TENNESSEE VALLEY TO THE MID ATLANTIC STATES
WILL PROVIDE SOUTHERN NEW ENGLAND WITH DRY WEATHER THROUGH THE
WEEKEND WITH WARMING TEMPERATURES. LOW PRESSURE OUT OF THE GREAT
LAKES WILL MOVE TO THE MID ATLANTIC COAST LATE SUNDAY NIGHT...THEN
WILL MOVE SLOWLY MOVE ACROSS THE REGION MONDAY INTO TUESDAY. A COLD
FRONT WILL TRAIL THROUGH TUESDAY NIGHT. ANOTHER FRONT MAY APPROACH
THE REGION LATE NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
410 PM UPDATE...
THE ONLY REMAINING LOW CLOUDS WERE OVER SOUTHERN NEW HAMPSHIRE AND
NORTH OF ROUTE 2 IN NORTHERN MA. THE RUC SHOWS THIS CLOUDINESS
HANGING AROUND MUCH LONGER THAN THE OTHER MODELS. THINK A
SIGNIFICANT PORTION OF IT WILL CLEAR OUT AFTER SUNDOWN. CLEAR SKIES
EXPECTED OVER THE REST OF SOUTHERN NEW ENGLAND AS STRONG HIGH
PRESSURE FROM THE TN VALLEY TO THE MID ATLANTIC INFLUENCES OUR
WEATHER. USED MAVMOSGUID BIAS CORRECTED GRIDS FOR LOWS TONIGHT.
LOWERED THEM BY A FEW DEGREES IN NORTHERN CHESHIRE COUNTY WHERE
HIGHS TODAY REMAINED IN THE 30S. WITH CLEARING SKIES AND LIGHT WINDS
THERE...IT COULD DROP TO MID 20S. ELSEWHERE EXPECTING LOWS IN THE
UPPER 20S TO MID 30S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...HIGH PRESSURE WITH CONTINUED WARMING TREND ALOFT
AND AT THE SURFACE. LIGHT WINDS AND ABUNDANT SUNSHINE EXPECTED.
TEMPERATURES AT 925 MB CLIMB TO 10-13C ON BOTH NAM AND GFS. USED
MAVMOS GUIDANCE WITH BIAS ADJUSTMENT WHICH YIELDS 60 TO 64 ACROSS
CT...MUCH OF RI...AND INTERIOR SE MA. LOWER TO MID 50S IN SOUTHERN
NH AND NW MA.
FRIDAY NIGHT...CLEAR SKIES AND LIGHT WINDS MAY ALLOW FOR
TEMPERATURES TO RADIATE DOWN TO PURE MAVMOS LEVELS WHICH WERE 5 TO
10 DEGREES LOWER THAN THE BIAS CORRECTED ONES. HOWEVER...AM OPTING
FOR A BLEND OF THE TWO SINCE WE WILL BE IN AN ANOMALOUSLY WARM
PATTERN. LOWS MAINLY IN THE MID 30S TO NEAR 40 BUT COOLER IN
NORTHWESTERN AREAS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
MODEL DISCUSSION AND PREFERENCES...
HIGH CONFIDENCE CONTINUES FOR THE FORECAST THIS WEEKEND AS STRONG
HIGH PRES BUILDS ALONG THE EASTERN SEABOARD.
BEYOND SUNDAY...THE FORECAST BECOMES VERY MUDDY TO SAY THE LEAST.
INDIVIDUAL OP MODEL SOLUTIONS HAVE VEERED IN THEIR OWN DIRECTIONS...
LEAVING A LOT TO TRY TO FIGURE OUT FOR SENSIBLE WEATHER AND TEMP
REGIME...ESPECIALLY WITH APPROACH OF LOW AND ASSOCIATED FRONT EARLY
NEXT WEEK. EVEN HPC CHANGED THEIR COURSE FOR THIS AFTERNOON/S MEDIUM
RANGE ISSUANCE. DID LEAN TOWARD HPC SOLUTION WHICH WENT TOWARD THE
GEFS ENSEMBLE MEANS...BUT THIS ONLY PLACES THE LOW IN BETWEEN THE
FAR NE 12Z OP GFS AND FAR SW ECMWF. NEEDLESS TO SAY...CONFIDENCE IS
VERY LOW FOR THE MON-WED TIMEFRAME /AT LEAST/.
SATURDAY-SUNDAY...
SPRING LIKE WEATHER WILL CONTINUE AS HIGH PRES OFF THE MID ATLC/SE
U.S. COAST. THIS WILL PUMP MILD AIR UP INTO THE REGION...WITH MODEL
850 HPA TEMPS ON THE ORDER OF +9C TO AS HIGH AS +11C SATURDAY AND
EVEN INTO SUNDAY. EXPECT MAINLY CLEAR SKIES ON SATURDAY...THEN
QUESTIONS IN PLACE AS TO WHETHER CLOUDS START TO MOVE IN DURING
SUNDAY. IN ANY EVENT...WITH RECORD HIGHS AT OUR FOUR MAJOR CLIMATE
SITES MAINLY IN THE MID-UPPER 60S...MAY SEE MAX TEMPS ON SATURDAY
/AND MAYBE SUNDAY TOO/ GETTING CLOSE TO RECORD LEVELS. HAVE INCLUDED
LIST OF RECORDS AND DATES IN CLIMATE SECTION BELOW.
SUNDAY NIGHT TO TUESDAY...
AS MENTIONED ABOVE...VERY LITTLE FORECAST CONFIDENCE DURING THIS
TIMEFRAME. FOR NOW...CONTINUED TO CARRY INCREASING POPS SUNDAY
NIGHT...WITH LIKELY POPS INTO WESTERN AREAS AFTER MIDNIGHT. LOOKS
LIKE BEST SHOT OF PRECIP COULD OCCUR MONDAY INTO MONDAY NIGHT. LOW
PRES ALONG THIS FRONT MAY ENHANCE THE RAINFALL ALONG WITH GOOD
TROPICAL CONNECTION UP THE COAST ON LONG S-SE FETCH. CONTINUED WITH
VERY MILD TEMPS THROUGH MONDAY NIGHT...RUNNING AT LEAST 10-15 DEGS
ABOVE SEASONAL NORMALS...THEN MAY START TO TRIM BACK AS FRONT COULD
PUSH E DURING TUESDAY. HAVE TRENDED TO END CHANCE POPS FROM W-E TUE
NIGHT.
WEDNESDAY...
A SECOND FRONT MAY PUSH ACROSS BY WED MORNING...SO MAY SEE SHOT OF
COOLER AIR WORKING IN ON W WINDS. TIMING IS HIGHLY UNCERTAIN...
THOUGH. DID NOT GO NEARLY AS COLD AS MOS GUIDANCE...PRETTY MUCH
LOWERED TEMPS A BIT FROM THE PREV FORECAST. MAY BE A BIT BREEZY
ESPECIALLY ALONG THE COAST DURING THE DAY.
THURSDAY...
WITH SUCH LOW CONFIDENCE...REALLY UNCERTAIN OF WEATHER FOR THIS
PERIOD. AT THIS POINT...HAVE CARRIED DRY WEATHER WITH SEASONABLE
TEMPS.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
410 PM UPDATE...
REST OF THIS AFTERNOON AND EVENING...THE ONLY REMAINING MVFR
CEILINGS AROUND 2000-2500 FT WERE OVER SOUTHERN NH AND NORTH OF
ROUTE 2 IN NORTHERN MA. THE RUC SHOWS THIS CLOUDINESS HANGING AROUND
MUCH LONGER THAN THE OTHER MODELS. THINK A SIGNIFICANT PORTION OF IT
WILL CLEAR OUT AFTER SUNDOWN. ELSEWHERE HIGH CONFIDENCE VFR WITH
CLEAR SKIES.
TONIGHT...HIGH CONFIDENCE VFR WITH CLEAR SKIES EXCEPT POSSIBLE
POCKETS OF MVFR CEILINGS CONTINUING IN THE MONADNOCKS OF SOUTHERN
NH. THIS SHOULD REMAIN TO THE WEST OF MHT...MODERATE CONFIDENCE OF
THAT.
FRIDAY... HIGH CONFIDENCE VFR WITH CLEAR OR MOSTLY CLEAR SKIES.
KBOS TERMINAL...
HIGH CONFIDENCE VFR THROUGH FRIDAY. THERE WILL BE SCT-BKN CLOUDS
IN THE 2000-2500 FT RANGE THROUGH ABOUT 01Z NOT TOO FAR TO THE
NORTH OF LOGAN INTL.
FRIDAY NIGHT...HIGH CONFIDENCE VFR WITH CLEAR OR MOSTLY CLEAR SKIES.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY...HIGH CONFIDENCE FOR VFR CONDITIONS. MAY SEE LOCAL
MVFR-IFR VSBYS IN PATCHY FOG LATE SAT NIGHT.
SUNDAY...MODERATE CONFIDENCE FOR MAINLY VFR. MID TO HIGH LEVEL
CLOUDS MAY MOVE IN FROM WEST TO EAST. MAY SEE LOCAL MVFR-IFR VSBYS
IN PATCHY FOG EARLY SUN MORNING.
SUNDAY NIGHT-MONDAY NIGHT...LOW CONFIDENCE. EXPECT VFR CIGS EARLY
SUN NIGHT...THEN MVFR CIGS/VSBYS IN DEVELOPING SHOWERS. MAY SEE
PERIODS OF IFR CONDITIONS LATE SUNDAY NIGHT-MONDAY WITH POCKETS OF
HEAVY RAIN POSSIBLE. ALSO MAY SEE IFR VSBYS IN PATCHY FOG LATE
NIGHTS ON SUN AND MON.
TUESDAY...LOW CONFIDENCE. AREAS OF MVFR CIGS/VSBYS IN SHOWERS EARLY
DURING THE DAY...THEN SHOULD SLOWLY IMPROVE LATE TUESDAY-TUESDAY
NIGHT FROM W-E...BUT TIMING IS HIGHLY SUSPECT.
&&
.MARINE...
TONIGHT AND FRIDAY...
SEAS HAVE BEEN STEADILY SUBSIDING THROUGHOUT THE AFTERNOON
BUT STILL REMAIN AT 5 TO 6 FEET ACROSS THE EASTERN OUTER WATERS.
HAVE CONTINUED THE SMALL CRAFT ADVISORIES FOR HAZARDOUS SEAS FOR
WATERS NORTH OF CAPE COD THROUGH 7 PM AND FOR THE WATERS OFF OF
CAPE COD AND SE OF NANTUCKET THROUGH 10 PM. EXPECTING ALL WATERS
TO BE BELOW THRESHOLDS BY AROUND 10 PM. PREFERRED WNAWAVE GRIDS TO
SWANNAM OR SWANGFS BECAUSE IT KEEPS SEAS HIGHER JUST TO THE EAST
OF OUR MARINE FORECAST AREA.
MODELS INDICATE THAT THERE WILL BE AN INCREASING PRESSURE GRADIENT
OVER THE SOUTHERN COASTAL WATERS ON FRIDAY AFTERNOON. THIS CAUSES
WEST TO SOUTHWEST WINDS TO GUST TO AROUND 20 KT AND
CORRESPONDINGLY THE SEAS WILL BEGIN TO INCREASE BACK TO AROUND
5 TO 6 FEET OVER THE SOUTHERN AND SOUTHEASTERN OUTER WATERS.
SMALL CRAFT ADVISORIES WILL AGAIN BE NEEDED FOR SOMEWHAT ROUGH SEAS.
FRIDAY NIGHT...CONDITIONS WILL REMAIN RATHER STEADY-STATE WITH SEAS
NEAR 5 TO 6 FEET OVER THE SOUTHERN AND SOUTHEASTERN WATERS. COULD
HAVE W TO SW WIND GUSTS TO 15 TO 20 KT OVER ALL COASTAL WATERS.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY-SUNDAY...W-SW WINDS MAY GUST CLOSE TO 20 KT DURING THE DAY
SAT...THEN WILL BACK TO S ON SUN. SEAS MAY LINGER AT 5-6 FT EARLY
SATURDAY ACROSS THE SOUTHERN OUTER WATERS...THEN SHOULD SUBSIDE.
SUNDAY NIGHT...S-SE WINDS SHOULD REMAIN BELOW SMALL CRAFT CRITERIA.
SEAS WILL BUILD BACK UP TO AROUND 5 FT ON THE SOUTHERN OPEN WATERS
MAINLY AFTER MIDNIGHT.
MONDAY...EXPECT SE WINDS GUSTING TO 25 KT FOR A TIME DURING THE
DAY...THEN SHIFT TO SW AND SHOULD DIMINISH MON NIGHT. SEAS MAY BUILD
UP TO 8 FEET OR GREATER...THOUGH SUSPECT WNA WAVEWATCH MODEL MAY BE
TOO HIGH USING THE GFS MODEL WHICH HAS STRONGEST GRADIENT AND LOW
PASSING CLOSE TO THE WATERS.
TUESDAY...W-SW WINDS MAY GUST TO 20 KT. SEAS STILL FORECASTED AROUND
8 FT BUT SHOULD SUBSIDE IF THEY REACH THAT HIGH.
&&
.TIDES/COASTAL FLOODING...
HAVE ISSUED ANOTHER COASTAL FLOOD STATEMENT FOR POSSIBLE POCKETS
OF MINOR COASTAL FLOODING OR SPLASHOVER NEAR THE TIME OF THE
FRIDAY MORNING HIGH TIDE...MAINLY BETWEEN 9 AM AND NOON.
ALTHOUGH WE WILL HAVE HIGHER ASTRONOMICAL TIDES THAN TODAY...WE WILL
HAVE LOWER SEAS AND AN OFFSHORE WIND WHICH SHOULD PREVENT ANYTHING
SIGNIFICANT FROM OCCURRING. MRPSSE GUIDANCE GAVE -0.5 FT SURGE
DUE TO THE OFFSHORE WINDS. WE CAPPED THESE AT NO LESS THAN -0.2 FT
JUST IN CASE THERE WAS SOME RESIDUAL LEFTOVER FROM TODAY.
&&
.CLIMATE...
WITH VERY MILD AIR WORKING UP THE COAST THIS WEEKEND...SEVERAL OF
THE FOUR MAJOR CLIMATE LOCATIONS MAY APPROACH RECORD HIGHS. HERE IS
A LIST OF THE RECORDS...
NOV 26 SAT NOV 27 SUN
BOSTON 67/1946 AND PREV 72/1896
WORCESTER 64/1895 66/1896
PROVIDENCE 67/2001 66/1946
BRADLEY 65/1979 64/1976
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 7 PM EST THIS
EVENING FOR ANZ250-251.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM EST THIS
EVENING FOR ANZ254-255.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM NOON FRIDAY TO 5
AM EST SATURDAY FOR ANZ256.
&&
$$
SYNOPSIS...EVT/GAF
NEAR TERM...GAF
SHORT TERM...GAF
LONG TERM...EVT/GAF
AVIATION...EVT/GAF
MARINE...EVT/GAF
TIDES/COASTAL FLOODING...GAF
CLIMATE...EVT
AREA FORECAST DISCUSSION
NWS TAUNTON MA
415 PM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE FROM THE TENNESSEE VALLEY TO THE MID ATLANTIC STATES
WILL PROVIDE SOUTHERN NEW ENGLAND WITH DRY WEATHER THROUGH THE
WEEKEND WITH WARMING TEMPERATURES. A COLD FRONT WILL SLOWLY MOVE
TOWARD THE REGION SUNDAY NIGHT...MOVING OFFSHORE LATE TUESDAY OR
TUESDAY NIGHT. ANOTHER FRONT MAY PUSH ACROSS THE REGION DURING THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
410 PM UPDATE...
THE ONLY REMAINING LOW CLOUDS WERE OVER SOUTHERN NEW HAMPSHIRE AND
NORTH OF ROUTE 2 IN NORTHERN MA. THE RUC SHOWS THIS CLOUDINESS
HANGING AROUND MUCH LONGER THAN THE OTHER MODELS. THINK A
SIGNIFICANT PORTION OF IT WILL CLEAR OUT AFTER SUNDOWN. CLEAR
SKIES EXPECTED OVER THE REST OF SOUTHERN NEW ENGLAND AS STRONG
HIGH PRESSURE FROM THE TN VALLEY TO THE MID ATLANTIC INFLUENCES
OUR WEATHER. USED MAVMOSGUID BIAS CORRECTED GRIDS FOR LOWS
TONIGHT. LOWERED THEM BY A FEW DEGREES IN NORTHERN CHESHIRE COUNTY
WHERE HIGHS TODAY REMAINED IN THE 30S. WITH CLEARING SKIES AND
LIGHT WINDS THERE...IT COULD DROP TO MID 20S. ELSEWHERE EXPECTING
LOWS IN THE UPPER 20S TO MID 30S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY... HIGH PRESSURE WITH CONTINUED WARMING TREND ALOFT AND AT
THE SURFACE. LIGHT WINDS AND ABUNDANT SUNSHINE EXPECTED.
TEMPERATURES AT 925 MB CLIMB TO 10-13C ON BOTH NAM AND GFS. USED
MAVMOS GUIDANCE WITH BIAS ADJUSTMENT WHICH YIELDS 60 TO 64 ACROSS
CT...MUCH OF RI...AND INTERIOR SE MA. LOWER TO MID 50S IN SOUTHERN
NH AND NW MA.
FRIDAY NIGHT... CLEAR SKIES AND LIGHT WINDS MAY ALLOW FOR
TEMPERATURES TO RADIATE DOWN TO PURE MAVMOS LEVELS WHICH WERE 5 TO
10 DEGREES LOWER THAN THE BIAS CORRECTED ONES. HOWEVER...AM OPTING
FOR A BLEND OF THE TWO SINCE WE WILL BE IN AN ANOMALOUSLY WARM PATTERN.
LOWS MAINLY IN THE MID 30S TO NEAR 40 BUT COOLER IN NORTHWESTERN
AREAS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...
* ABOVE AVERAGE AND DRY WEATHER FOR THE WEEKEND
* PRECIP CHANCES INCREASING BEGINNING NEXT WEEK
* TEMPS WILL BE CLOSE TO AVERAGE LATER IN THE WEEK
CONFIDENCE...
ANOTHER TRICKY FORECAST FOR THIS MORNING AS MODEL SPREAD CONTINUES
TO BE QUITE LARGE. HAVE HIGH CONFIDENCE IN THE FORECAST FOR SATURDAY
AND EVEN INTO SUNDAY. ALSO CONFIDENCE IS INCREASING THAT TEMPS FOR
SAT THROUGH TUESDAY WILL BE ABOVE SEASONABLE AVERAGE AS SOUTHWEST
FLOW CONTINUES TO DOMINATE THE REGION. VERY LOW CONFIDENCE ON TIMING
OF PRECIP ON MONDAY THROUGH WEDNESDAY AS MODELS ARE STRUGGLING WITH
THE MEDIUM RANGE. IN THE EXTENDED PORTION OF THE
FORECAST...CONFIDENCE IS INCREASING THAT TEMPS WILL BE CLOSE TO OR
BELOW AVERAGE. HOWEVER HAVE HIGH UNCERTAINTY ON CHANCE OF
PRECIPITATION. FOR NOW LEFT THURSDAY DRY...BUT DEPENDING ON MODEL
SOLUTION PRECIP MAY NEED TO BE INSERTED.
FRIDAY PM - SATURDAY...
ALL SHORT RANGE MODELS ARE CONSISTENT FOR THE BEGINNING PERIODS OF
THIS FORECAST. HIGH PRESSURE WILL SET UP ACROSS THE CAROLINAS AND
EVENTUALLY BE PUSHED OFF SHORE BY A STOUT TROUGH DIGGING THROUGH THE
CENTER CONUS BY SUNDAY.
WITH THE HIGH PRESSURE SOUTH OF THE REGION...WESTERLY WINDS WILL SET
UP ACROSS SOUTHERN NEW ENGLAND. THIS WILL HELP INCREASE TEMPS AT
LEAST 10F ABOVE AVERAGE. WITH A GOOD AMOUNT OF WAA...850MB TEMPS
WILL INCREASE TO 8-10C. MID TO HIGH LEVEL CLOUDS WILL STREAM THROUGH
THE NORTHERN HALF OF THE AREA...WHICH COULD EFFECT HOW MUCH THE
REGION MIXES OUT. LOW TEMPS FOR THIS PORTION OF THE FORECAST WILL BE
MILD...REACHING THE MID 40S ALONG THE COAST WITH THE UPPER 30S TO
LOW 40S IN THE INTERIOR.
SUNDAY - TUESDAY...
THIS IS THE POINT WHERE ALL MODELS DIVERGE FROM EACH OTHER. THE GFS
KEEPS THE LONGWAVE TROUGH INTACT WITH A CUTOFF LOW MOVING ACROSS THE
GREAT LAKES. WHERE AS THE ECMWF IS PERSISTENT ON KEEPING A CUTOFF LOW
ACROSS THE TX/LA BORDER. WITH THIS CUTOFF LOW...AN UPPER LEVEL
DISTURBANCE WILL MOVE ACROSS THE THE GREAT LAKES AND INTO THE
NORTHEAST. EITHER WAY BOTH MODEL SOLUTIONS BRING PRECIP TO THE
REGION LATE SUNDAY NIGHT AND INTO MONDAY. THE QUESTION IS JUST HOW
MUCH AND THE EXACT TIMING. THE GFS HAS BEEN THE MOST CONSISTENT FROM
RUN TO RUN...AND BEING LESS DRAMATIC WITH THE POTENTIAL OF A CUT OFF
LOW. THE ECMWF HAS ALSO BEEN CONSISTENT WITH A CUT OFF LOW IN LA/TX
REGION...AS WELL AS CONTINUING TO BE MORE PROGRESSIVE. WITH ALL THE
UNCERTAINTY IN HAND...TRENDED TOWARDS THE GFS ENSEMBLES AS WELL AS
HPC.
STOUT SOUTHERLY WINDS WILL BE BREEZY ON SUNDAY AHEAD OF A SURFACE
TROUGH. EXPECT PRECIP TO BEGIN FROM WEST TO EAST IN THE LATE
MORNING/EARLY AFTERNOON ON SUNDAY AS SURFACE LOW PASSES ACROSS
SOUTHERN NEW ENGLAND BY MONDAY AFTERNOON. TEMPS WILL BEGIN TO
DECLINING BACK TO AVERAGE BY TUESDAY. BEST TIME FRAME FOR PRECIP WILL
BE EARLY MONDAY MORNING. STILL SOME UNCERTAINTY ON TIMING AND
AMOUNTS. STAY TUNE FOR FURTHER FORECAST ON THIS SYSTEM.
WEDNESDAY - THURSDAY...
WITH THE SPREAD OF THE MODELS INCREASING...THIS PORTION OF THE
FORECAST REMAINS LOW CONFIDENCE. THE MORE AMPLIFIED...CUT OFF
LOW...ECMWF KEEPS THE AREA WET AS THE LOW PRESSURE SYSTEM GETS
KICKED BACK UP INTO THE LONG WAVE PATTERN AND MOVES ACROSS THE
REGION. WHERE AS THE GFS KEEPS THE AREA DRY UNTIL AN UPPER LEVEL
DISTURBANCE PUSHES THROUGH ON BY LATE THURSDAY...INDICATING PERHAPS
A COASTAL STORM. BECAUSE OF THE VERY LOW CONFIDENCE...KEPT THE POPS
FORECAST LOW AND TRENDED TOWARDS A COOLER TEMPERATURE SOLUTION.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
410 PM UPDATE...
REST OF THIS AFTERNOON AND EVENING... THE ONLY REMAINING MVFR
CEILINGS AROUND 2000-2500 FT WERE OVER SOUTHERN NH AND NORTH OF
ROUTE 2 IN NORTHERN MA. THE RUC SHOWS THIS CLOUDINESS HANGING
AROUND MUCH LONGER THAN THE OTHER MODELS. THINK A SIGNIFICANT
PORTION OF IT WILL CLEAR OUT AFTER SUNDOWN. ELSEWHERE HIGH
CONFIDENCE VFR WITH CLEAR SKIES.
TONIGHT... HIGH CONFIDENCE VFR WITH CLEAR SKIES EXCEPT POSSIBLE
POCKETS OF MVFR CEILINGS CONTINUING IN THE MONADNOCKS OF SOUTHERN
NH. THIS SHOULD REMAIN TO THE WEST OF MHT... MODERATE CONFIDENCE
OF THAT.
FRIDAY... HIGH CONFIDENCE VFR WITH CLEAR OR MOSTLY CLEAR SKIES.
KBOS TERMINAL...
HIGH CONFIDENCE VFR THROUGH FRIDAY. THERE WILL BE SCT-BKN CLOUDS
IN THE 2000-2500 FT RANGE THROUGH ABOUT 01Z NOT TOO FAR TO THE
NORTH OF LOGAN INTL.
OUTLOOK...FRIDAY NIGHT THROUGH MONDAY...
FRIDAY NIGHT...HIGH CONFIDENCE VFR WITH CLEAR OR MOSTLY CLEAR SKIES.
SATURDAY...HIGH CONFIDENCE FOR VFR CONDITIONS.
SATURDAY NIGHT-SUNDAY...HIGH CONFIDENCE FOR MAINLY VFR. MID TO HIGH
LEVEL CLOUDS WILL MOVE IN FROM WEST TO EAST. MAY SEE LOCAL MVFR-IFR
VSBYS IN PATCHY FOG LATE SAT NIGHT/SUN MORNING.
SUNDAY NIGHT-MONDAY...MODERATE CONFIDENCE. EXPECT VFR CIGS EARLY SUN
NIGHT...THEN MVFR CIGS/VSBYS IN DEVELOPING SHOWERS. MAY SEE LOCAL
IFR VSBYS IN FOG SUN NIGHT-MON MORNING.
&&
.MARINE...
410 PM UPDATE...
TONIGHT...
SEAS HAVE BEEN STEADILY SUBSIDING THROUGHOUT THE AFTERNOON
BUT STILL REMAIN AT 5 TO 6 FEET ACROSS THE EASTERN OUTER WATERS.
HAVE CONTINUED THE SMALL CRAFT ADVISORIES FOR HAZARDOUS SEAS FOR
WATERS NORTH OF CAPE COD THROUGH 7 PM AND FOR THE WATERS OFF OF
CAPE COD AND SE OF NANTUCKET THROUGH 10 PM. EXPECTING ALL WATERS
TO BE BELOW THRESHOLDS BY AROUND 10 PM. PREFERRED WNAWAVE GRIDS TO
SWANNAM OR SWANGFS BECAUSE IT KEEPS SEAS HIGHER JUST TO THE EAST
OF OUR MARINE FORECAST AREA.
MODELS INDICATE THAT THERE WILL BE AN INCREASING PRESSURE GRADIENT
OVER THE SOUTHERN COASTAL WATERS ON FRIDAY AFTERNOON. THIS CAUSES
WEST TO SOUTHWEST WINDS TO GUST TO AROUND 20 KT AND
CORRESPONDINGLY THE SEAS WILL BEGIN TO INCREASE BACK TO AROUND
5 TO 6 FEET OVER THE SOUTHERN AND SOUTHEASTERN OUTER WATERS.
SMALL CRAFT ADVISORIES WILL AGAIN BE NEEDED FOR SOMEWHAT ROUGH SEAS.
OUTLOOK...FRIDAY NIGHT THROUGH MONDAY...
FRIDAY NIGHT...CONDITIONS WILL REMAIN RATHER STEADY-STATE WITH
SEAS NEAR 5 TO 6 FEET OVER THE SOUTHERN AND SOUTHEASTERN WATERS.
COULD HAVE W TO SW WIND GUSTS TO 15 TO 20 KT OVER ALL COASTAL
WATERS.
SATURDAY - SATURDAY NIGHT...
HIGH PRESSURE WILL SET UP ACROSS THE CAROLINAS KEEPING THE WATERS IN
A WEST TO SOUTHWESTERLY FLOW. GOOD MIXING ACROSS THE WATERS WILL
HELP BUILD SEAS TO ABOVE SCA...ESPECIALLY ACROSS THE OUTER WATERS.
AFTER SUNSET ON SATURDAY...BOTH SEAS AND WIND WILL RELAX BELOW SCA.
SUNDAY - MONDAY...
SURFACE TROUGH WILL APPROACH THE REGION ON SUNDAY...INCREASING
SOUTHERLY WINDS TO 20 KTS. EXPECT SEAS TO BEGIN TO BUILD ABOVE 5FT
STARTING ON THE SOUTHERN OUTER WATERS AND EVENTUALLY INCREASING
ACROSS ALL WATERS BY MONDAY. SURFACE LOW PRESSURE SYSTEM WILL
APPROACH THE REGION BY MONDAY ALLOWING FOR WINDS TO SWITCH FROM A
STOUT SOUTHERLY DIRECTION TO THE WEST. HAVE HIGH CONFIDENCE THAT A
SCA WILL BE NEEDED DURING THIS TIMEFRAME FOR THE OUTER WATERS AND
ALONG THE COASTS.
&&
.TIDES/COASTAL FLOODING...
HAVE ISSUED ANOTHER COASTAL FLOOD STATEMENT FOR POSSIBLE POCKETS
OF MINOR COASTAL FLOODING OR SPLASHOVER NEAR THE TIME OF THE
FRIDAY MORNING HIGH TIDE...MAINLY BETWEEN 9 AM AND NOON.
ALTHOUGH WE WILL HAVE HIGHER ASTRONOMICAL TIDES THAN TODAY...WE WILL
HAVE LOWER SEAS AND AN OFFSHORE WIND WHICH SHOULD PREVENT ANYTHING
SIGNIFICANT FROM OCCURRING. MRPSSE GUIDANCE GAVE -0.5 FT SURGE
DUE TO THE OFFSHORE WINDS. WE CAPPED THESE AT NO LESS THAN -0.2 FT
JUST IN CASE THERE WAS SOME RESIDUAL LEFTOVER FROM TODAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 7 PM EST THIS
EVENING FOR ANZ250-251.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM EST THIS
EVENING FOR ANZ254-255.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM NOON FRIDAY TO 5
AM EST SATURDAY FOR ANZ256.
&&
$$
SYNOPSIS...GAF/DUNTEN
NEAR TERM...GAF
SHORT TERM...GAF
LONG TERM...DUNTEN
AVIATION...GAF/DUNTEN
MARINE...GAF/DUNTEN
TIDES/COASTAL FLOODING...GAF
AREA FORECAST DISCUSSION
NWS ALBANY NY
402 PM EST THU NOV 24 2011
.SYNOPSIS...
THE WEATHER PATTERN WILL BE TRANQUIL FOR THIS HOLIDAY WEEKEND AS
HIGH PRESSURE REMAINS IN CONTROL ACROSS THE EASTERN SEABOARD.
TEMPERATURES WILL SLOWLY MODERATE TO ABOVE NORMAL AS SOUTHERLY
WINDS INCREASE. THE NEXT CHANCE FOR SHOWERS ARRIVES LATE SUNDAY
INTO MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
STRATUS DECK WAS ALONG THE I90 CORRIDOR AS OF 19Z. THIS CLOUD DECK
CONTINUES TO SLOWLY ERODE AND MIGRATE NORTHWARD THIS AFTERNOON.
NCEP MODEL SUITE AND HOURLY RUC13 LOW LEVEL RH FIELDS SUGGEST THIS
STRATUS DECK SHOULD CONTINUE TO LIFT NORTHWARD AND ERODE FURTHER.
MEANWHILE...WARM ADVECTION ALOFT AND ITS ASSOCIATED HIGH AND SOME
MID LEVEL CLOUDS ARE QUICKLY MOVING ACROSS NEW ENGLAND AND
PORTIONS OF UPSTATE NEW YORK. THIS TOO IS EXPECTED TO SLIDE
OFFSHORE TONIGHT LEAVING BEHIND A PTCLOUDY-MOCLEAR SKIES.
BASED ON CURRENT DEWPOINTS...MOS TEMPERATURES LOOK A BIT COOL AND
HAVE FOLLOWED WARMER OVERNIGHT TRENDS WITHIN THE LAV/LAMP
GUIDANCE.
LARGE AREA OF HIGH PRESSURE...CENTERED OVER THE SOUTHEAST
CONUS...WILL BE THE DOMINANT PLAYER FOR THIS NEAR TERM AND INTO
THE SHORT TERM.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THIS LARGE AREA OF HIGH PRESSURE WILL KEEP THE WEATHER QUIET EAST
OF THE MISSISSIPPI RIVER THROUGH THIS SHORT TERM PERIOD. IN
FACT...RATHER PRONOUNCED WEST-SOUTHWEST FLOW ALONG WITH MILD MID
LEVEL TEMPS WILL RESULT IN TEMPERATURES CLIMBING TOWARD OR
EXCEEDING 10 DEGREES ABOVE CLIMATOLOGY /IN ADDITION...DOWNSLOPING
MAY ENHANCE THESE TEMPS INTO THE VALLEY LOCATIONS/. THE ONLY
COMPLICATION COULD BE SOME OVERNIGHT SHALLOW BR/FG AND A POTENTIAL
FOR SOME LOW LEVEL STRATUS DEVELOPMENT. IN ADDITION...WITH THE
ONGOING WARM ADVECTION...SOME HIGH AND MID LEVEL CLOUD COVER MAY
MOVE ACROSS THE SKY THOUGH THIS PERIOD. EITHER WAY...THE WEATHER
SHOULD HAVE MINIMAL IMPACT TO HOLIDAY WEEKEND TRAVELS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ACTIVE WEATHER PATTERN EXPECTED THROUGH THE LONG TERM...BUT MODEL
GUIDANCE HAS DIFFERING SOLUTIONS...SO CONFIDENCE IS LOW. WENT WITH
HPC GUIDANCE.
SFC LOW APPROACHING FROM THE GREAT LAKES REGION SUNDAY MORNING. 12Z
GFS...ECMWF AND GFSENSEMBLE MEMBERS HAVE NOT AGREED UPON A
TRACK...SPEED...OR QPF AMOUNTS. ECMWF HAS THE MORE PROGRESSIVE AND
NORTHERLY TRACK OF SFC LOW...WITH THE COLD FRONT AND PRECIP
ASSOCIATED WITH THE LOW MOVING THROUGH THE FA LATE SUNDAY THROUGH
LATE MONDAY...WITH QPF AMOUNTS AROUND HALF AN INCH OR LESS.
ASSOCIATED UPPER LEVEL POSITIVELY TILTED TROUGH REMAINS OPEN IN
ECMWF.
MEANWHILE...GFS DEVELOPS A CLOSE LOW WITHIN THE UPPER LEVEL TROUGH.
AS THIS TROUGH APPEARS TO HAVE A NEUTRAL TILT...GFS KEEPS IT SLOW
MOVING OVER THE GREAT LAKES REGION...WHERE THE UPPER LEVEL LOW
PRESSURE CENTER REFORMS FURTHER NORTH SUNDAY NIGHT. THE TROUGH
BECOMES NEGATIVELY TILTED BEFORE A PIECE OF SOUTHERLY ENERGY BREAKS
OFF...TRAVELING TOWARDS THE OBX AHEAD OF THE MAIN TROUGH...BY
TUESDAY NIGHT. QPF AMOUNTS UP TO 2 INCHES WITH THE GFS.
CHANCE FOR PRECIP POSSIBLE THROUGH TUESDAY NIGHT/WEDNESDAY WITH GFS
ENSEMBLE MEMBERS SLOWLY MOVE SFC LOW NORTHWARD TOWARDS JAMES BAY.
ALL GUIDANCE SHOW HIGH PRESSURE BUILDING IN JUST SOUTH OF THE
REGION...BUT NO AGREEMENT ON WHEN OR FOR HOW LONG. HPC HAS HIGH
PRESSURE WEDNESDAY INTO THURSDAY.
TEMPS ABOUT 10 DEGREES ABOVE NORMAL TO START THE PERIOD...TRENDING
COOLER TO ABOUT NORMAL BY THE END OF THE PERIOD.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD ENDING
AT 18Z FRIDAY. STRATOCUMULUS HAVE LIFTED NORTH OF KPOU AND WILL
LIFT NORTH OF KALB BY 19Z. KGFL WILL CONTINUE TO HAVE
STRATOCUMULUS WITH MVFR CONDITIONS FOR THE REMAINDER OF THE AFT.
SKIES WILL BE MAINLY SKC OR SCT250 TONIGHT WITH SOME FOG PSBL AT
KGFL AND KPOU WITH MAINLY MVFR CONDITIONS EXPECTED AFT 07Z. ON
FRIDAY SKC CONDITIONS ARE EXPECTED AT THE TAF SITES AFT 12Z AS A
LARGE RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION.
EXPECT WINDS WILL REMAIN SOUTH AT 3-5 KTS THROUGH THE REMAINDER OF
THIS AFT...BECOME LIGHT AND VARIABLE TONIGHT...AND SOUTH AT 4-6
KTS FRI MRNG.
OUTLOOK...
FRIDAY AFT-SAT NIGHT...VFR. NO SIG WX.
SUN...MAINLY VFR. INCREASING CLDS. CHC -SHRA LATE.
SUN NIGHT-MON...MVFR/IFR IN RAIN AND MIST.
&&
.HYDROLOGY...
DRY WEATHER IS EXPECTED THROUGH MOST OF THE LONG HOLIDAY WEEKEND
AS HIGH PRESSURE DOMINATES. OUR NEXT CHANCES FOR WET WEATHER WILL
RETURN LATE IN THE WEEKEND INTO EARLY NEXT WEEK AS A LOW PRESSURE
SYSTEM APPROACHES AND MOVES ACROSS THE REGION. THERE IS MUCH
UNCERTAINTY WITH REGARDS TO THE SYSTEM AS THERE IS A LARGE SPREAD
IN THE MODEL GUIDANCE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.CLIMATE...
2011 HAS MOVED UP INTO FIFTH PLACE FOR WETTEST YEARS ON RECORD
FOR ALBANY NEW YORK.
WETTEST YEARS - ALBANY NY - SINCE 1820
1) 55.78 INCHES 1871
2) 55.81 INCHES 1870
3) 51.83 INCHES 1850
4) 49.80 INCHES 1827
5) 49.75 INCHES THROUGH NOVEMBER 23ND
6) 49.37 INCHES 1878
7) 48.35 INCHES 1843
8) 48.22 INCHES 1848
9) 47.79 INCHES 2008
10) 47.72 INCHES 2005
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...KGM
AVIATION...11
HYDROLOGY...BGM
CLIMATE...IAA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1259 PM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO OUR REGION THIS THANKSGIVING
THURSDAY AND DOMINATE OUR WEATHER INTO SUNDAY. A COLD FRONT...
APPROACHING FROM THE WEST...WILL MOVE SLOWLY ACROSS OUR REGION
SUNDAY NIGHT INTO MONDAY. LOW PRESSURE MAY DEVELOP ON THE FRONT
ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY NORTHWARD MONDAY
NIGHT INTO TUESDAY NIGHT. MORE LOW PRESSURE IS POSSIBLE DURING
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD AIR ADVECTION IS ENDING. HOWEVER TEMPERATURES WITH THE
PREVIOUS FORECAST ARE ON TRACK TODAY WITH SLIGHT ALTERATIONS
BASED ON 14Z METAR OBS. RAISED VISIBILITY A BIT ON THIS UPDATE ALSO
BASED OFF OF 14Z OBS. PREVIOUS FORECASTER THINKING BELOW STILL
LOOKS GOOD SO FEW CHANGES MADE OVERALL ATTM. A VERY NICE
THANKSGIVING DAY IS AHEAD OF US!
CONVECTIVE TEMPERATURES ARE OUT OF REACH TODAY...AND OTHER THAN
SOME HIGH CLOUDINESS THIS MORNING...SKIES SHOULD BE SUNNY. THE
BEST PART OF THE SURFACE PRESSURE GRADIENT IS OVER THE FORECAST
AREA NOW...AND SOME GUSTINESS LINGERS. THE GUSTINESS TO THE WIND
SHOULD DROP BACK EARLY THIS MORNING AS THE LAST OF THE COLD AIR
ADVECTION ENDS.
IT IS POSSIBLE THERE COULD BE SOME GUSTINESS TODAY...BUT FOR THE
MOST PART WINDS SHOULD NOT BE AN ISSUE TODAY. 850 MB TEMPERATURES
SUPPORT HIGHS IN THE MID 50S TODAY...WHICH IS CLOSE TO THE MOS
BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
BUILDING MID LEVEL RIDGING SHOULD KEEP ANY HIGH AND MID LEVEL CLOUDS
NORTH OF THE AREA TONIGHT...AND SKIES SHOULD BE CLEAR. AS THE HIGH
REACHES NORTH CAROLINA TONIGHT...THE GRADIENT WILL BACK OFF.
HOWEVER...WINDS MAY NOT BECOME COMPLETELY CALM OUTSIDE OF PROTECTED
AREAS...AS THE GRADIENT WOULD SUPPORT WEST WINDS LESS THAN 10 MPH.
THE ABOVE SCENARIO WOULD SUPPORTS LOWS NEAR THE MOS BLEND IN THE
URBAN AREAS AND PLACES WITH EXPOSURE. FOR PROTECTED AREAS (INCLUDING
THE PINE BARRENS IN NEW JERSEY)...LOWS WERE DROPPED A FEW DEGREES
FROM THE MOS MEAN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A QUIESCENT PERIOD OF WEATHER IS SHAPING UP FOR THE NORTHERN MID
ATLANTIC AREA FRIDAY INTO SUNDAY. THE MODELS HAVE LATCHED ONTO A
COLD FRONT WHICH LOOKS LIKE IT WILL AFFECT OUR AREA MAINLY SUNDAY
NIGHT INTO MONDAY. THEN...MODEL PERFORMANCE HAS SEEMINGLY
DETERIORATED OVER THE PAST 24 TO 48 HOURS, WITH RUN-TO-RUN AND
INTERMODEL INCONSISTENCY AND CHANGEABILITY. WITH NO CLEAR
SIGNALS...IT WAS DECIDED TO JUST USE A BROAD BRUSH OF CHANCE
PROBABILITIES FOR SHOWERS THROUGH THE MONDAY THROUGH WEDNESDAY
PERIOD, WITH A MODERATE TO HIGH AMOUNT OF CLOUDINESS. THE GFS EVEN
PAINTS SOME TYPE OF RAIN/SNOW EVENT WEDNESDAY NIGHT INTO THURSDAY.
LATER MODEL ITERATIONS WILL BE NEEDED TO GAIN MORE CLARITY ON THIS
PERIOD.
SO...HPC TEMPERATURES WERE USED AS A STARTING POINT FOR HIGHS AND
LOWS, WITH SOME MODIFICATIONS FOR LOCAL EFFECTS AND CLIMATOLOGY. A
GENERAL COOLING TREND SHOULD OCCUR THROUGH THE LONG TERM PERIOD...
WITH HIGHS IN THE MID 50S AND LOWER 60S OVER THE WEEKEND, DROPPING
TO THE 40S TO NEAR 50 BY WEDNESDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL CONTINUE TO PROVIDE US WITH FINE VFR
FLYING CONDITIONS FRIDAY INTO...OR PERHAPS THROUGH MOST OF...SUNDAY.
A COLD FRONT MOVING IN FROM THE WEST SUNDAY NIGHT WILL MOVE EASTWARD
THROUGH OUR AREA. HOWEVER, A SUCCESSION OF LOWS COULD AFFECT OUR
REGION AND PERHAPS BRING LOWER CONDITIONS AT TIMES INTO THE EARLY OR
EVEN MIDDLE PORTION OF NEXT WEEK. MODEL GUIDANCE HAS BEEN CHANGING
AND INCONSISTENT...SO LITTLE IN THE WAY OF CONFIDENCE CAN BE SHOWN
UNTIL THE MODELS START TO OFFER BETTER AGREEMENT AND RUN-TO-RUN
CONSISTENCY. LOWER CEILINGS AND/OR VISIBILITIES IN SHOWERS/RAIN AND
FOG MAY OCCUR THROUGH MUCH OF THE SUNDAY NIGHT THROUGH WEDNESDAY
TIME PERIOD, THOUGH.
&&
.MARINE...
WINDS AND SEAS CONTINUE TO DECREASE ON THE WATERS THIS MORNING.
THE SCA FLAG FOR THE DELAWARE BAY AND THE NORTHERN COASTAL WATERS
HAVE BEEN TAKEN DOWN. SEAS REMAIN UP ACROSS THE SOUTHERN COASTAL
WATERS...SO THE FLAG WILL CONTINUE THERE INTO THE MID-AFTERNOON. A
FEW GUSTS UP TO 25 KTS STILL MAY OCCUR ON THE WATERS THIS
AFTERNOON...BUT THE TREND CONTINUES DOWNWARD AS HIGH PRESSURE
BUILDS IN. SUB SCA CONDITIONS EXPECTED TONIGHT INTO FRIDAY AND
WINDS WILL BACK AROUND TO W THEN SW.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR MARINE
AREA FRIDAY THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST,
A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY. THE PRESSURE
GRADIENT WILL TIGHTEN BETWEEN THESE TWO SYSTEMS...AND THIS WILL MEAN
A GOOD CHANCE OF SHOWERS AS WELL AS INCREASING SOUTH TO SOUTHEAST
WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY. A SERIES OF LOW
PRESSURE SYSTEMS COULD AFFECT OUR AREA THROUGH THE EARLY AND MIDDLE
PORTIONS OF NEXT WEEK...BUT MODEL GUIDANCE HAS BECOME TOO CHANGEABLE
AND INCONSISTENT TO OFFER ANY KIND OF SPECIFICS. ADVISORY CONDITIONS
ARE LIKELY AT SOME POINT...AND EVEN GALE CONDITIONS MAY OCCUR FOR A
TIME...IN THE SUNDAY NIGHT TO MID WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
THE CFW FOR THE UPPER DELAWARE BAY HAS EXPIRED. HIGH TIDE IS
OCCURRING AT PHILADELPHIA PRESENTLY AND WILL TAKE A FEW HOURS MORE
TO REACH THE UPPER PORTIONS OF THE DELAWARE RIVER. THE CFW FOR
THOSE AREAS WILL BE TAKEN DOWN AT 3 PM.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
PAZ071.
NJ...COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
NJZ018-019.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
ANZ452>455.
&&
$$
SYNOPSIS...
NEAR TERM...GAINES/HAYES
SHORT TERM...HAYES
LONG TERM...
AVIATION...HAYES
MARINE...HAYES
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS LINCOLN IL
300 PM CST THU NOV 24 2011
.DISCUSSION...
ISSUED 300 PM CST THU NOV 24 2011
INITIAL CONCERN WILL BE POSSIBLE REDEVELOPMENT OF LOW STRATUS
CLOUDS TONIGHT INTO FRIDAY MORNING. THEN ATTENTION TURNS TO THE
ONSET OF RAIN LATE FRIDAY NIGHT THROUGH SATURDAY AND THE ARRIVAL
OF COLDER AIR FOR MUCH OF THE EXTENDED FORECAST.
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT.
CHALLENGING FORECAST FOR TONIGHT IN TERMS OF CLOUDS AND RESULTANT
LOW TEMPS. THE ONLY MODELS THAT SEEM TO HAVE A DECENT HANDLE ON
THE LOW LEVEL MOISTURE ARE THE HRRR AND SPC 4KM WRF. BOTH OF THEM
ARE INDICATING CLOUD REDEVELOPMENT ACROSS CENTRAL IL AND EVEN
SURROUNDING PORTIONS OF IL. THE NAM AND GFS SOUNDINGS SHOW A LOW
LEVEL SATURATION AS WELL...BUT SHALLOW. FORECAST WIND TRAJECTORY
FLOWS INDICATE WE SHOULD SEE THE SW RETURN FLOW ORIGINATING WHERE
STRATUS CLOUDS ARE LINGERING THIS AFTERNOON IN MO/AR. A TIGHTER
PRESSURE GRADIENT WOULD TYPICALLY KEEP WINDS UP AT NIGHT...BUT THE
LOW LEVEL INVERSION LOOKS TO BE PLENTY STRONG ENOUGH TO PREVENT
MIXING OVERNIGHT. WILL FORECAST CLOUDS TO REFORM...AND KEEP LOW
TEMPS A COUPLE DEGREES WARMER THAN GUIDANCE.
CLEARING SHOULD COME QUICKER ON FRIDAY AS MORE PROMINENT MIXING
WILL OCCUR UNDER A MUCH STRONGER SFC PRESSURE GRADIENT. PLENTY OF
DRY AIR ALOFT WILL AID IN CLOUD EROSION. WINDY CONDITIONS ARE
EXPECTED WITH SSW GUSTS OVER 30 MPH. TEMPS WILL RESPOND IN KIND AS
WAA FLOWS PUSH 850 MB TEMPS UP NEAR 12C. THAT COUPLED WITH ADDITIONAL
SUNSHINE SHOULD PUT HIGHS INTO THE L-M 60S.
BROAD SCALE ISENTROPIC LIFT AHEAD OF THE NEXT COLD FRONT WILL HELP
PRIME THE ATMOSPHERE FOR RAIN TO DEVELOP W OF THE IL RIVER AFTER
MIDNIGHT FRIDAY NIGHT. HOWEVER...BASED ON FORECAST CONDENSATION
PRESSURE DEFICITS /CPD/...IT STILL APPEARS WE WILL HAVE A 5-7 HOUR
WINDOW OF STEADY RAINS AS THE FRONT PROGRESSES EASTWARD DURING THE
DAY ON SATURDAY. WE WILL CONTINUE WITH CATEGORICAL POPS WEST IN
THE MORNING AND EAST IN THE AFTERNOON. SOME SHOWERS MAY LINGER IN
THE EVENING ACROSS THE EAST...SO WILL CONTINUE WITH CHANCE POPS AS
SUBSIDENT FLOWS BEGIN TO SHUT DOWN MEASURABLE PRECIP.
COLD AIR WILL RETURN ON BRISK NW WINDS SAT NIGHT. MOST OF THE
PRECIP SHOULD COME TO AN END BEFORE THE AIR COLUMN GETS COLD
ENOUGH FOR SNOW. HOWEVER...WE CAN NOT RULE OUT SOME FLURRIES
POSSIBLE AFTER MIDNIGHT SAT NIGHT. BY 12Z SUNDAY...ANOTHER WAVE OF
ISENTROPIC LIFT AND LOW CPD/S IS INDICATED AS THE UPPER TROUGH MOVES
ACROSS IL. ENOUGH RESIDUAL MOISTURE MAY BE PRESENT FOR A FEW LIGHT
RAIN/SNOW SHOWERS AFTER MIDNIGHT...AND FLURRIES NORTH/SPRINKLES
SOUTH ON SUNDAY.
BY SUNDAY NIGHT...ALL PRECIP SHOULD COME TO AN END FROM THIS
SYSTEM...AS THE UPPER TROUGH AXIS FINALLY SLIDES EAST.
LONG TERM...MONDAY THROUGH THURSDAY.
THE EXTENDED FORECAST SHOWS PERSISTENT COLD CONDITIONS AS A CUT
OFF LOW POSSIBLY DEVELOPS ACROSS THE SOUTHERN OHIO RIVER VALLEY.
THERE HAS BEEN A WIDE VARIETY OF SOLUTIONS FROM THE MODELS ON THIS
CUT OFF FEATURE...WITH THE ECMWF AND THE CANADIAN THE MAIN ONES
SHOWING THIS FEATURE. THE ECMWF BEING A BIT MORE PRONOUNCED AND
SLOWER THAN THE CANADIAN. THE GFS KEEPS A PROGRESSIVE PATTERN WITH
NORTHWEST FLOW AND A DRY FRONTAL PASSAGE ON MONDAY NIGHT/TUESDAY
ACROSS IL. DESPITE THE DIFFERING SOLUTIONS...THE OVERALL SENSIBLE
WEATHER LOOKS TO BE ON THE CHILLY SIDE WITH PERIODICALLY BREEZY
CONDITIONS.
SHIMON
&&
.AVIATION...
ISSUED 1142 AM CST THU NOV 24 2011
LOW CLOUDS WILL CONTINUE TO STEADILY ERODE FROM WEST TO EAST
ACROSS CENTRAL ILLINOIS THIS AFTERNOON. SATELLITE TIMING TOOLS
INDICATE SKIES BECOMING MOSTLY CLEAR AT KPIA AND KSPI BY
19Z...THEN FURTHER EAST TO KCMI BY 21Z. AFTER A PERIOD OF CLEAR
SKIES AT ALL TERMINALS LATE THIS AFTERNOON/EVENING...THE BIG
QUESTION BECOMES WHETHER THE LOW CLOUDS/FOG WILL RETURN LATER
TONIGHT. 12Z NAM FORECAST SOUNDINGS ARE SHOWING THE STRONG
SUBSIDENCE INVERSION REMAINING IN PLACE...WITH SATURATION
OCCURRING BELOW 950MB AFTER 03Z. DESPITE SOME DECENT MIXING/DRYING
THIS AFTERNOON...AM HARD PRESSED TO IGNORE THESE SOUNDINGS AS WELL
AS SIMPLE PERSISTENCE. AS A RESULT...HAVE BROUGHT CEILINGS BACK
DOWN BELOW 1000FT AT ALL TAF SITES AFTER 05Z. IN ADDITION...A
DEVELOPING JET STREAK ABOVE THE INVERSION WILL LEAD TO LOW-LEVEL
WIND SHEAR OVERNIGHT. HAVE INCLUDED 35 TO 40KT OF SHEAR AT 2000FT
ACCORDINGLY. THE LOW CLOUDS WILL MIX OUT BY MID-MORNING
FRIDAY...ALLOWING GUSTY S/SW WINDS TO MIX DOWN TO THE SURFACE
AFTER 15Z.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
254 PM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* CIGS NEAR 1000 FT SCATTERING/CLEARING 21-22Z FROM WEST.
* POTENTIAL FOR IFR/LIFR CIGS TO REDEVELOP THIS EVENING AND
OVERNIGHT...THEN SCATTERING MID MORNING FRIDAY.
* PERIODS OF GUSTY SOUTHWEST WINDS TO AROUND 20 KT.
* POTENTIAL FOR LLWS TONIGHT.
MDB
//DISCUSSION...UPDATED 20Z...
STRATUS STARTING TO ERODE MORE QUICKLY FROM THE WEST AND SHOULD BE
REACHING RFD NEXT HOUR OR SO AND THE NE IL AIRPORTS 21-22Z AND
SOON AFTER AT GYY. STILL HAVE SOME CONCERN THAT FEW-SCT LOW CLOUDS
WILL LINGER AS SUNSET APPROACHES BUT HAVE SLIGHTLY BETTER
CONFIDENCE THAT VFR WILL PERSIST SO HAVE ADJUSTED TAFS
ACCORDINGLY. LOW CONFIDENCE REMAINS IN POTENTIAL FOR LOW
STRATUS/IFR TO REDEVELOP SOMETIME THIS EVENING OR TONIGHT.
FROM 18Z...
IFR AND LOWER STRATUS CONTINUES ACROSS THE TERMINALS EARLY THIS
AFTERNOON. SATELLITE TRENDS SHOW THE WESTERN EDGE OF THE STRATUS
THINNING AND ERODING FROM NEAR DBQ TO JUST EAST OF GBG DOWN TO
NEAR SPI AT 1745Z AND WORKING ITS WAY EAST. STRONG LOW LEVEL
INVERSION REMAINS IN PLACE WHICH WILL LIKELY MAKE IT MORE
DIFFICULT FOR THE CLEARING TO QUICKLY WORK EAST...ESPECIALLY BY
LATE AFTERNOON BUT AM THINKING THAT THE TAF SITES WILL BE ABLE TO
SCATTER LATE THIS AFTERNOON. HOW QUICKLY THIS OCCURS IS NOT QUITE
CERTAIN. UNTIL THEN CLOUD BASES LOOK TO REMAIN FAIRLY STEADY WITH
SOME MINIMAL INCREASE INTO MID AFTERNOON...WITH A MORE NOTABLE
INCREASE IN BASES POSSIBLE AS SCATTERING OCCURS...THOUGH BASES
WOULD LIKELY REMAIN BELOW 1500 FT. SOUTHWEST WINDS WILL CONTINUE
TO BE GUSTY THOUGH GUSTS MAY BE ERRATIC IN FREQUENCY.
ASSUMING SCATTERING/CLEARING CAN OCCUR BY EVENING THE NEXT
CHALLENGE WILL BE IF IFR/LIFR CEILINGS CAN RETURN OVERNIGHT.
INVERSION WILL REMAIN IN PLACE AND LOW LEVEL MOISTURE SHOULD
REMAIN HIGH...ESPECIALLY GIVEN THAT SCATTERING WILL HAPPEN CLOSER
TO DARK LIMITING THE CHANCE FOR DRIER AIR TO MIX DOWN. CONFIDENCE
IS LOW SO WILL CONTINUE WITH THE TREND OF EARLIER FORECASTS TO
BRING IFR BACK TO THE TERMINALS LATER THIS EVENING. THE INVERSION
SHOULD HAVE A BETTER TIME MIXING OUT LATER FRIDAY MORNING ALLOWING
ANY IFR TO CLEAR OUT BY MIDDAY OR SO. SOUTHWEST WINDS WILL REMAIN
BREEZY TONIGHT WITH GUSTS INCREASING TO AROUND 25 KT...IF NOT
SLIGHTLY HIGHER FRIDAY.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM-HIGH CONFIDENCE IN CIGS SCATTERING/CLEARING 21-22Z.
* LOW-MEDIUM CONFIDENCE IFR CIGS WILL REDEVELOP THIS EVENING AND
PERSIST INTO MID MORNING FRIDAY.
* MEDIUM-HIGH CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* HIGH CONFIDENCE IN WINDS INCREASING OFF THE DECK LATE THIS
EVENING...MEDIUM CONFIDENCE THAT STRONG LLWS WILL DEVELOP.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. CHANCE OF SHRA.
SATURDAY...MVFR WITH IFR POSSIBLE. PERIODS OF RAIN DURING THE DAY.
CHANCE OF SHRA/SHSN SATURDAY NIGHT.
SUNDAY...MVFR POSSIBLE. CHANCE OF SHRA/SHSN.
MONDAY THROUGH WEDNESDAY...VFR. CMS
&&
.MARINE...
229 PM CST
STRONG SOUTHWEST WINDS AND WIND GUSTS HAVE DEVELOPED ACROSS THE LAKE
DUE TO THE TIGHT PRESSURE GRADIENT OVER THE REGION. WIND GUSTS TO 30
KT WITH OCCASIONAL GUSTS TO 35 KT GALES CAN BE EXPECTED THROUGH
THIS EVENING OVER THE OPEN WATERS. AT THE MOMENT NO GALE GUSTS HAVE BEEN
REPORTED...MOST LIKELY DUE TO THE STUBBORN LOW LEVEL STRATUS DECK
OVER THE LAKE. HOWEVER...THE POSSIBILITY OF SEEING GUSTS TO 35 KT
GALES REMAINS THROUGH THIS EVENING. WITH ONLY OCCASIONAL GALE GUSTS
EXPECTED...DECIDED TO HOLD OFF ON GALE RELATED HEADLINES. GUST TO
30 KT WILL PERSIST ON FRIDAY BUT NOT ANTICIPATING ANY GALES. LOW
PRESSURE OVER MINNESOTA MOVES OVER LAKE MICHIGAN ON SATURDAY AND
THE LOWS COLD FRONT SWINGS THROUGH LATE ON SATURDAY. THE LOW
ITSELF WILL REMAIN IN THE GREAT LAKES REGION THROUGH MONDAY BEFORE
MERGING INTO A LARGER LOW OVER EASTERN MANITOBA. WINDS WILL TURN
OUT OF THE NORTHWEST BEHIND THE LOW WITH NO SIGNIFICANT GUSTS TO
MENTION. LOOKING INTO NEXT WEEK...A CANADIAN HIGH SINKS SOUTH FROM
ALBERTA INTO THE CENTRAL PLAINS ON TUESDAY. THE HIGH THEN MOVES
OVER THE EASTERN HALF OF THE US...LEADING TO LIGHT WEST TO
NORTHWEST WINDS THROUGH THE EXTENDED.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
155 PM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* CIGS NEAR 1000 FT SCATTERING/CLEARING 21-22Z FROM WEST.
* POTENTIAL FOR IFR/LIFR CIGS TO REDEVELOP THIS EVENING AND
OVERNIGHT...THEN SCATTERING MID MORNING FRIDAY.
* PERIODS OF GUSTY SOUTHWEST WINDS TO AROUND 20 KT.
* POTENTIAL FOR LLWS TONIGHT.
MDB
//DISCUSSION...UPDATED 20Z...
STRATUS STARTING TO ERODE MORE QUICKLY FROM THE WEST AND SHOULD BE
REACHING RFD NEXT HOUR OR SO AND THE NE IL AIRPORTS 21-22Z AND
SOON AFTER AT GYY. STILL HAVE SOME CONCERN THAT FEW-SCT LOW CLOUDS
WILL LINGER AS SUNSET APPROACHES BUT HAVE SLIGHTLY BETTER
CONFIDENCE THAT VFR WILL PERSIST SO HAVE ADJUSTED TAFS
ACCORDINGLY. LOW CONFIDENCE REMAINS IN POTENTIAL FOR LOW
STRATUS/IFR TO REDEVELOP SOMETIME THIS EVENING OR TONIGHT.
FROM 18Z...
IFR AND LOWER STRATUS CONTINUES ACROSS THE TERMINALS EARLY THIS
AFTERNOON. SATELLITE TRENDS SHOW THE WESTERN EDGE OF THE STRATUS
THINNING AND ERODING FROM NEAR DBQ TO JUST EAST OF GBG DOWN TO
NEAR SPI AT 1745Z AND WORKING ITS WAY EAST. STRONG LOW LEVEL
INVERSION REMAINS IN PLACE WHICH WILL LIKELY MAKE IT MORE
DIFFICULT FOR THE CLEARING TO QUICKLY WORK EAST...ESPECIALLY BY
LATE AFTERNOON BUT AM THINKING THAT THE TAF SITES WILL BE ABLE TO
SCATTER LATE THIS AFTERNOON. HOW QUICKLY THIS OCCURS IS NOT QUITE
CERTAIN. UNTIL THEN CLOUD BASES LOOK TO REMAIN FAIRLY STEADY WITH
SOME MINIMAL INCREASE INTO MID AFTERNOON...WITH A MORE NOTABLE
INCREASE IN BASES POSSIBLE AS SCATTERING OCCURS...THOUGH BASES
WOULD LIKELY REMAIN BELOW 1500 FT. SOUTHWEST WINDS WILL CONTINUE
TO BE GUSTY THOUGH GUSTS MAY BE ERRATIC IN FREQUENCY.
ASSUMING SCATTERING/CLEARING CAN OCCUR BY EVENING THE NEXT
CHALLENGE WILL BE IF IFR/LIFR CEILINGS CAN RETURN OVERNIGHT.
INVERSION WILL REMAIN IN PLACE AND LOW LEVEL MOISTURE SHOULD
REMAIN HIGH...ESPECIALLY GIVEN THAT SCATTERING WILL HAPPEN CLOSER
TO DARK LIMITING THE CHANCE FOR DRIER AIR TO MIX DOWN. CONFIDENCE
IS LOW SO WILL CONTINUE WITH THE TREND OF EARLIER FORECASTS TO
BRING IFR BACK TO THE TERMINALS LATER THIS EVENING. THE INVERSION
SHOULD HAVE A BETTER TIME MIXING OUT LATER FRIDAY MORNING ALLOWING
ANY IFR TO CLEAR OUT BY MIDDAY OR SO. SOUTHWEST WINDS WILL REMAIN
BREEZY TONIGHT WITH GUSTS INCREASING TO AROUND 25 KT...IF NOT
SLIGHTLY HIGHER FRIDAY.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM-HIGH CONFIDENCE IN CIGS SCATTERING/CLEARING 21-22Z.
* LOW-MEDIUM CONFIDENCE IFR CIGS WILL REDEVELOP THIS EVENING AND
PERSIST INTO MID MORNING FRIDAY.
* MEDIUM-HIGH CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* HIGH CONFIDENCE IN WINDS INCREASING OFF THE DECK LATE THIS
EVENING...MEDIUM CONFIDENCE THAT STRONG LLWS WILL DEVELOP.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. CHANCE OF SHRA.
SATURDAY...MVFR WITH IFR POSSIBLE. PERIODS OF RAIN DURING THE DAY.
CHANCE OF SHRA/SHSN SATURDAY NIGHT.
SUNDAY...MVFR POSSIBLE. CHANCE OF SHRA/SHSN.
MONDAY THROUGH WEDNESDAY...VFR. CMS
&&
.MARINE...
300 AM CST
WINDS HAVE BEEN A LITTLE SLOW TO INCREASE THIS MORNING DESPITE A
FAIRLY TIGHT PRESSURE GRADIENT AND STRONG FLOW ALOFT IN PLACE. WITH
TWO SEPARATE AREAS OF LOW PRESSURE TO THE NORTH AND NORTHWEST OF THE
LAKE AND A RIDGE OF HIGH PRESSURE JUST TO THE SOUTHEAST...STRONG
SOUTHERLY FLOW CONTINUES TO USHER IN WARMER AIR TO THE NORTH.
BELIEVE THIS IS WHAT MAY BE CAUSING THIS SLOW INCREASE IN WIND SPEED
AS A SLIGHTLY MORE STABLE LAKE MAY BE IN PLACE THAN WHAT CURRENT
GUIDANCE IS INDICATING. NONETHELESS...WINDS WILL CONTINUE TO
INCREASE TODAY AS THIS TIGHT PRESSURE GRADIENT REMAINS AND FLOW
ALOFT INCREASES. PERSISTENT SOUTHWEST WINDS TO 30 KT CAN BE EXPECTED
INTO FRIDAY FOR BOTH THE NORTH AND SOUTH HALF OF LAKE MICHIGAN. HAVE
LEFT OUT ANY MENTION OF GALES FOR THE LAKE THIS FORECAST
ISSUANCE...BUT DO THINK THERE MAY BE BRIEF PERIODS OF HIGHER WINDS
AROUND GALES LATE THIS AFTERNOON AND EARLY EVENING MAINLY FOR THE
NORTH HALF OF THE LAKE. ALTHOUGH DO FEEL THAT THIS WILL BE SPORADIC
AND BRIEF...THUS LEAVING ANY MENTION OF GALES OUT OF THE CURRENT
FORECAST. SOUTHWEST WINDS WILL SLOWLY BEGIN TO DIMINISH FRIDAY NIGHT
INTO SATURDAY...BUT WILL BECOME MORE WESTERLY ON SATURDAY AS AN AREA
OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY PUSH ACROSS THE
LAKE. THEN A PERIOD OF WEST TO NORTHWEST WINDS CAN BE EXPECTED INTO
THE START OF NEXT WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1214 PM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CIGS AROUND 700 FT LIFTING SLIGHTLY TO NEAR 1000 FT THEN
EXPECTED TO SCATTER TOWARDS ROUGHLY 22-23Z.
* POTENTIAL FOR IFR/LIFR CIGS TO REDEVELOP THIS EVENING AND
OVERNIGHT...THEN SCATTERING MID MORNING FRIDAY.
* PERIODS OF GUSTY SOUTHWEST WINDS TO AROUND 20 KT.
* POTENTIAL FOR LLWS TONIGHT.
MDB
//DISCUSSION...UPDATED 18Z...
IFR AND LOWER STRATUS CONTINUES ACROSS THE TERMINALS EARLY THIS
AFTERNOON. SATELLITE TRENDS SHOW THE WESTERN EDGE OF THE STRATUS
THINNING AND ERODING FROM NEAR DBQ TO JUST EAST OF GBG DOWN TO
NEAR SPI AT 1745Z AND WORKING ITS WAY EAST. STRONG LOW LEVEL
INVERSION REMAINS IN PLACE WHICH WILL LIKELY MAKE IT MORE
DIFFICULT FOR THE CLEARING TO QUICKLY WORK EAST...ESPECIALLY BY
LATE AFTERNOON BUT AM THINKING THAT THE TAF SITES WILL BE ABLE TO
SCATTER LATE THIS AFTERNOON. HOW QUICKLY THIS OCCURS IS NOT QUITE
CERTAIN. UNTIL THEN CLOUD BASES LOOK TO REMAIN FAIRLY STEADY WITH
SOME MINIMAL INCREASE INTO MID AFTERNOON...WITH A MORE NOTABLE
INCREASE IN BASES POSSIBLE AS SCATTERING OCCURS...THOUGH BASES
WOULD LIKELY REMAIN BELOW 1500 FT. SOUTHWEST WINDS WILL CONTINUE
TO BE GUSTY THOUGH GUSTS MAY BE ERRATIC IN FREQUENCY.
ASSUMING SCATTERING/CLEARING CAN OCCUR BY EVENING THE NEXT
CHALLENGE WILL BE IF IFR/LIFR CEILINGS CAN RETURN OVERNIGHT.
INVERSION WILL REMAIN IN PLACE AND LOW LEVEL MOISTURE SHOULD
REMAIN HIGH...ESPECIALLY GIVEN THAT SCATTERING WILL HAPPEN CLOSER
TO DARK LIMITING THE CHANCE FOR DRIER AIR TO MIX DOWN. CONFIDENCE
IS LOW SO WILL CONTINUE WITH THE TREND OF EARLIER FORECASTS TO
BRING IFR BACK TO THE TERMINALS LATER THIS EVENING. THE INVERSION
SHOULD HAVE A BETTER TIME MIXING OUT LATER FRIDAY MORNING ALLOWING
ANY IFR TO CLEAR OUT BY MIDDAY OR SO. SOUTHWEST WINDS WILL REMAIN
BREEZY TONIGHT WITH GUSTS INCREASING TO AROUND 25 KT...IF NOT
SLIGHTLY HIGHER FRIDAY.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN CEILINGS LIFTING TO NEAR 1000 FT THIS AFTERNOON.
* MEDIUM CONFIDENCE CEILINGS WILL SCATTER OUT...LOW-MEDIUM
CONFIDENCE IN TIMING.
* MEDIUM CONFIDENCE IFR CIGS WILL REDEVELOP THIS EVENING AND
PERSIST INTO MID MORNING FRIDAY.
* MEDIUM-HIGH CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* HIGH CONFIDENCE IN WINDS INCREASING OFF THE DECK LATE THIS
EVENING BUT LOW-MEDIUM CONFIDENCE THAT STRONG LLWS WILL DEVELOP.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. CHANCE OF SHRA.
SATURDAY...MVFR WITH IFR POSSIBLE. PERIODS OF RAIN DURING THE DAY.
CHANCE OF SHRA/SHSN SATURDAY NIGHT.
SUNDAY...MVFR POSSIBLE. CHANCE OF SHRA/SHSN.
MONDAY THROUGH WEDNESDAY...VFR. CMS
&&
.MARINE...
300 AM CST
WINDS HAVE BEEN A LITTLE SLOW TO INCREASE THIS MORNING DESPITE A
FAIRLY TIGHT PRESSURE GRADIENT AND STRONG FLOW ALOFT IN PLACE. WITH
TWO SEPARATE AREAS OF LOW PRESSURE TO THE NORTH AND NORTHWEST OF THE
LAKE AND A RIDGE OF HIGH PRESSURE JUST TO THE SOUTHEAST...STRONG
SOUTHERLY FLOW CONTINUES TO USHER IN WARMER AIR TO THE NORTH.
BELIEVE THIS IS WHAT MAY BE CAUSING THIS SLOW INCREASE IN WIND SPEED
AS A SLIGHTLY MORE STABLE LAKE MAY BE IN PLACE THAN WHAT CURRENT
GUIDANCE IS INDICATING. NONETHELESS...WINDS WILL CONTINUE TO
INCREASE TODAY AS THIS TIGHT PRESSURE GRADIENT REMAINS AND FLOW
ALOFT INCREASES. PERSISTENT SOUTHWEST WINDS TO 30 KT CAN BE EXPECTED
INTO FRIDAY FOR BOTH THE NORTH AND SOUTH HALF OF LAKE MICHIGAN. HAVE
LEFT OUT ANY MENTION OF GALES FOR THE LAKE THIS FORECAST
ISSUANCE...BUT DO THINK THERE MAY BE BRIEF PERIODS OF HIGHER WINDS
AROUND GALES LATE THIS AFTERNOON AND EARLY EVENING MAINLY FOR THE
NORTH HALF OF THE LAKE. ALTHOUGH DO FEEL THAT THIS WILL BE SPORADIC
AND BRIEF...THUS LEAVING ANY MENTION OF GALES OUT OF THE CURRENT
FORECAST. SOUTHWEST WINDS WILL SLOWLY BEGIN TO DIMINISH FRIDAY NIGHT
INTO SATURDAY...BUT WILL BECOME MORE WESTERLY ON SATURDAY AS AN AREA
OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY PUSH ACROSS THE
LAKE. THEN A PERIOD OF WEST TO NORTHWEST WINDS CAN BE EXPECTED INTO
THE START OF NEXT WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1021 AM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CIGS AROUND 700 FT SLOWLY LIFTING TO AROUND 1000 FT SOMETIME
EARLY THIS AFTERNOON...POTENTIAL FOR SCATTERING LATE THIS
AFTERNOON.
* IFR/LIFR CIGS REDEVELOPING THIS EVENING AND OVERNIGHT.
* PERIODS OF GUSTY SOUTHWEST WINDS TO AROUND 20 KT.
* POTENTIAL FOR LLWS TONIGHT.
MDB
//DISCUSSION...UPDATED 16Z...
IFR/LIFR STRATUS CONTINUES ACROSS THE TERMINALS WITH IFR VSBY AS
WELL. STILL EXPECT THAT BASES WILL GRADUALLY LIFT THIS AFTERNOON
WITH VSBY ALSO IMPROVING. THE TWO MAIN CHALLENGES IS HOW HIGH
BASES WILL GET THIS AFTERNOON AND THEY WILL SCATTER ACROSS ANY OF
THE TERMINALS. LATEST SATELLITE TRENDS SHOW THINNING/ERODING OF
STRATUS ALONG THE MISSISSIPPI RIVER FROM SOUTH OF ST. LOUIS
NORTHWARD TOWARDS THE QUAD CITIES AND EXPECT THIS EROSION TO
SPREAD EASTWARD. LATEST AIRCRAFT SOUNDINGS CONTINUE TO SHOW VERY
STRONG LOW LEVEL INVERSION OVER THE LOCAL AREA WHICH WILL ACT TO
KEEP CLOUDS IN PLACE AND LIMIT THE EASTERN EXTENT OF CLEARING INTO
THE AFTERNOON. THAT SAID...THINK AREAS SOUTH AND WEST OF THE
TERMINALS WILL SCATTER/CLEAR INTO EARLY AFTERNOON BUT INVERSION
MAY TRAP ENOUGH MOISTURE TO DEVELOP NEW STRATOCU AS HEATING
COMMENCES. FOR THE TERMINALS...THERE IS A CHANCE THAT SCATTERING
WILL OCCUR MID/LATE AFTERNOON BUT HAVE LIMITED CONFIDENCE THAT
THIS WILL OCCUR SO WILL MAKE LITTLE CHANGE TO THE TAF BEYOND 20Z
FOR NOW.
FROM 12Z...
VERY LARGE AREA OF IFR/LIFR CIGS EXTENDS FROM THE GREAT LAKES
SOUTH TO THE ARKLATEX THIS MORNING. LOCALLY THESE CLOUDS ARE
TRAPPED UNDER A VERY STRONG INVERSION JUST A FEW THOUSAND FEET
ALOFT AND IT WILL LIKELY BE UNTIL AT LEAST EARLY THIS AFTERNOON
BEFORE THESE CLOUDS POTENTIALLY SHOW SOME BREAKS OR SCATTER OUT.
WHILE CIGS SHOULD SLOWLY DIURNALLY LIFT THROUGH IFR INTO LOW MVFR
THIS AFTERNOON...CONFIDENCE ON TIMING AND SPECIFIC HEIGHTS IS LOW.
THE INVERSION ALOFT BECOMES EVEN STRONGER TONIGHT AND WITH LOW
LEVEL MOISTURE STILL STREAMING NORTH...SHOULD CLOUDS SCATTER OUT
THEY SHOULD QUICKLY REDEVELOP BY LATE EVENING/EARLY FRIDAY
MORNING. THOUGH THE INVERSION DOES MIX OUT RATHER QUICKLY AFTER
SUNRISE FRIDAY MORNING. VISIBILITIES HAVE GENERALLY BEEN IN THE
2-4SM RANGE MOST AREAS AND NOT EXPECTING ANYTHING MUCH LOWER THAN
THAT...AT LEAST NOT ANYTHING WIDESPREAD. THE VIS SHOULD IMPROVE
THROUGH THE MORNING BUT LIKELY DROP BACK INTO MVFR THIS EVENING
AND OVERNIGHT.
DESPITE THE LOW INVERSION...WINDS HAVE GUSTED IN THE 15-20KT
RANGE DURING THE EARLY MORNING HRS AND EXPECT GUSTS IN THIS RANGE
FOR MUCH OF THE DAY...WITH THE POTENTIAL FOR SOME HIGHER GUSTS
DURING THE AFTERNOON SHOULD LOW CLOUDS SCATTER OUT. GRADIENT
REMAINS TIGHT THROUGH THE NIGHT AND LOW LEVEL WINDS ALOFT INCREASE
TO 40-45 KTS BY 2KFT...THUS THE POTENTIAL FOR LLWS. HAVE OPTED TO
LEAVE THIS OUT OF THIS FORECAST SINCE IT IS QUITE POSSIBLE SURFACE
WINDS WILL BE GUSTY AND CONFIDENCE REGARDING MEETING LLWS CRITERIA
IS LOW. CMS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE IFR CIGS WILL LIFT TO LOW MVFR EARLY THIS
AFTERNOON...LOW CONFIDENCE ON TIMING AND IF CIGS WILL LIFT TO
MUCH ABOVE 1000 FT.
* LOW CONFIDENCE LOW MVFR CIGS WILL SCATTER OUT THIS AFTERNOON.
* MEDIUM CONFIDENCE IFR CIGS WILL REDEVELOP THIS EVENING AND
PERSIST INTO MID MORNING FRIDAY.
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* LOW CONFIDENCE REGARDING LLWS TONIGHT.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. CHANCE OF SHRA.
SATURDAY...MVFR WITH IFR POSSIBLE. PERIODS OF RAIN DURING THE DAY.
CHANCE OF SHRA/SHSN SATURDAY NIGHT.
SUNDAY...MVFR POSSIBLE. CHANCE OF SHRA/SHSN.
MONDAY THROUGH WEDNESDAY...VFR. CMS
&&
.MARINE...
300 AM CST
WINDS HAVE BEEN A LITTLE SLOW TO INCREASE THIS MORNING DESPITE A
FAIRLY TIGHT PRESSURE GRADIENT AND STRONG FLOW ALOFT IN PLACE. WITH
TWO SEPARATE AREAS OF LOW PRESSURE TO THE NORTH AND NORTHWEST OF THE
LAKE AND A RIDGE OF HIGH PRESSURE JUST TO THE SOUTHEAST...STRONG
SOUTHERLY FLOW CONTINUES TO USHER IN WARMER AIR TO THE NORTH.
BELIEVE THIS IS WHAT MAY BE CAUSING THIS SLOW INCREASE IN WIND SPEED
AS A SLIGHTLY MORE STABLE LAKE MAY BE IN PLACE THAN WHAT CURRENT
GUIDANCE IS INDICATING. NONETHELESS...WINDS WILL CONTINUE TO
INCREASE TODAY AS THIS TIGHT PRESSURE GRADIENT REMAINS AND FLOW
ALOFT INCREASES. PERSISTENT SOUTHWEST WINDS TO 30 KT CAN BE EXPECTED
INTO FRIDAY FOR BOTH THE NORTH AND SOUTH HALF OF LAKE MICHIGAN. HAVE
LEFT OUT ANY MENTION OF GALES FOR THE LAKE THIS FORECAST
ISSUANCE...BUT DO THINK THERE MAY BE BRIEF PERIODS OF HIGHER WINDS
AROUND GALES LATE THIS AFTERNOON AND EARLY EVENING MAINLY FOR THE
NORTH HALF OF THE LAKE. ALTHOUGH DO FEEL THAT THIS WILL BE SPORADIC
AND BRIEF...THUS LEAVING ANY MENTION OF GALES OUT OF THE CURRENT
FORECAST. SOUTHWEST WINDS WILL SLOWLY BEGIN TO DIMINISH FRIDAY NIGHT
INTO SATURDAY...BUT WILL BECOME MORE WESTERLY ON SATURDAY AS AN AREA
OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY PUSH ACROSS THE
LAKE. THEN A PERIOD OF WEST TO NORTHWEST WINDS CAN BE EXPECTED INTO
THE START OF NEXT WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
352 PM EST THU NOV 24 2011
.SHORT TERM...
TONIGHT THROUGH FRIDAY NIGHT
BROAD SW UPPER FLOW REMAINS IN PLACE OVER THE REGION WITH SFC
PRESSURE FALLS CONTINUING OVER THE UPPER MIDWEST IN RESPONSE TO A
PROGRESSING NORTHERN STREAM TROUGH. A STAUNCH INVERSION REMAINS IN
PLACE PER A SIG WAA REGIME...WITH TRAPPED MOISTURE IN THE BL.
INSOLATION AND ENSUED MIXING PROCESSES ARE WORKING TO BREAK THE
PERSISTENT CLOUD DECK UP...AND SOME SUN WILL BE POSSIBLE IN AREAS
THIS AFTERNOON. HOWEVER...DIURNAL BL COOLING WILL LIKELY SUPPORT
RE-SATURATION WITH THE CLOUD LAYER FILLING BACK IN...THIS BEING THE
MAIN FORECAST CHALLENGE. TEMPS HAVE STRUGGLED TO RISE ACROSS THE FA
GIVEN CLOUD COVER...BUT POSITIVE THERMAL ADVECTION HAS ALLOWED FOR
SOME RECOVERY AS LL WIND INCREASES PER HIGHER LATITUDE PRESSURE
FALLS. SYNOPTIC EVOLUTION IN THE PERIOD WILL FEATURE CENTRAL PLAINS
PHASING OF THE PAC NW AND SW CONUS UPPER TROUGHS...WITH A WAA REGIME
CONTINUING THROUGH THE PERIOD AHEAD OF THE LL TROUGH REFLECTION.
HEIGHT RISES COMBINED WITH A DIRTY TYPE RIDGE RIDDLED WITH LOW
AMPLITUDE IMPULSES WILL SUPPORT INCREASING CIRRUS ON FRIDAY. MUCH
WARMER WEATHER IS IN STORE FRIDAY GIVEN A TREND TO MOSTLY SUNNY
CONDITIONS AND WARM THERMAL FIELDS IN THE SFC TO H925 LAYER.
RAOB AND TAMDAR ANALYSIS CONFIRM A SATURATED LAYER IN THE
H975-H95 LAYER...WITH LOCAL CLOUD LAYER SOURCE BACK TRAJECTORY
SAMPLING A LARGE PORTION OF THE STRATUS LAYER IN PLACE OVER THE
LOWER MISSISSIPPI VALLEY. BULK OF DRY AIR PUSH ASSOCIATED WITH
REFLECTED LL FLOW WILL REMAIN NORTH OF THE REGION...WITH H975-H95
FLOW REMAINING SOUTHERLY OVERNIGHT. RUC13 AND NAM12 BOTH SUGGEST
RE-SATURATION OF THIS LAYER...WHICH IS VERY REASONABLE GIVEN CLOUD
LAYER TRAJECTORIES/A SHARP BL TOP INVERSION/AND AMPLE LL MOISTURE IN
THE BL. HENCE...EXPECTING CLOUDS TO FILL BACK IN THIS EVENING.
INCREASING NOCTURNAL LLJ AND ASSOCIATED TURBULENT MIX DOWN MAY
SUPPORT SOME CLOUD BREAK UP LATE IN THE NIGHT...ESP ACROSS THE
NORTHWEST WHERE H95 GEOSTROPHIC FLOW INCREASES TO OVER 35 KNOTS.
CLOUD LAYER FLOW WILL VEER SW TOWARD DAWN AND HELP SUPPORT THE
ADVECTION OF HIGH PLAINS SOURCE DRIER AIR...WITH CLEARING OF CIGS
THROUGH LATE MORNING. PHASING UPPER TROUGH WITH SLOW EAST ADVECTION
WILL DELAY ANY PRECIP CHANCES UNTIL SATURDAY GIVEN CONTINUED DRY
DEEP LAYER FLOW WITH THE BULK OF ALL SYSTEM GENERATED ASCENT
REMAINING WELL NORTH AND WEST OF THE REGION.
NO SIG CHANGE TO TEMPS. CLOUDS AND MIXED LL FLOW WILL SUPPORT A
RELATIVELY MILD NIGHT TONIGHT AND FRIDAY...WITH LOWS IN THE
40S...COOLEST READINGS TONIGHT. CLEARING LL STRATUS/WARM THERMAL
FIELDS/AND GENEROUS MIXING WILL SUPPORT HIGHS INTO THE 50S...WITH
SOME LOWER 60S POSSIBLE ACROSS THE SW THIRD FRIDAY.
&&
.LONG TERM...
SATURDAY THROUGH THURSDAY. PRIMARY FOCUS ON DY3 PRECIP TIMING AND
INTRO RASN MIX LATE SAT NIGHT TO PRIMARY FZN PTYPE ON SUN...IN LES
REGN. LARGE DISCREPANCIES IN MID RANGE...HOWEVER FAVOR NAM/GFS/SREF
DVLPG GRTLKS CUTOFF DY3 AS OPPOSED TO ECMWF/GEM TAKING FAR SRN
DIXIE/GOMEX CUTOFF. GIVEN RAMPED NRN STREAM FLOW ACRS ENTIRE PACIFIC
TO JAPAN GTE 150 KTS PER SAT DERIVED WINDS...AIDED BY COMPLEX BC TO
ALEUTIANS VORTEX. STRONG/DEEP CAA IN MERIDONAL FLOW AS UL RIDGE FM
SOCAL BUILDS TOWARD SRN CANADA 12 UTC SUN. ADNLY NO ENSEMBLE GFS
MEMBERS TAKE STRONG SRN CUTOFF APPROACH. NAM/GFS BUFKIT WET BULB
PROFILES WOULD SUGGEST THAT PTYPE CHANGEOVER MAY BE COMPLETE TO FZN
ACRS NRN/NWRN CWA LATE SAT NIGHT...BUT GIVEN ALL LIQUID PRIOR FCST
WL ATTEMPT TO START TREND. SOME ACCUM PSBL IN LES REGN SUN...THOUGH
EXTRM DISCREPANCIES IN CBL FLOW AS EXPECTED AT F72-84. ATTENDENT SFC
LOW SHOULD BEGIN LIFTOUT MON WITH CONTINUATION OF PROGRESSIVE NRN
STREAM FLOW AND IN COLLAB WITH MI NEIGHBORS HAVE AXED PRIOR LOW CHC
MENTION MON-TUE NIGHT. FEW CHANGES OTHERWISE...APPEARS NEXT NRN
STREAM TROF DIGS INTO WRN GRTLKS/UPR MSVLY PER GEFS ON DY7 WITH
POTNL CHC SHSN THEREAFTER.
&&
.AVIATION.../18Z TAFS/
IFR CIGS WILL REMAIN IN PLACE FOR MOST OF THE DAY GIVEN TRAPPED LL
MOISTURE UNDER A STAUNCH INVERSION. SCOURING OF THIS CLOUD DECK IS
ONGOING ACROSS WESTERN IL AND THIS IS EXPECTED TO SLOWLY SPREAD
INTO THE AREA LATE THIS AFTERNOON AND EVENING PER NEGATIVE THETA-E
ADV INTO THE SATURATED CLOUD LAYER. HENCE...EXPECT A SW-NE IFR-
VFR TREND IN TAFS...ESP WESTERN HALF. THIS PROCESS MAY SEE A DELAY
GIVEN DIURNAL BL COOLING THIS EVENING...ESP EASTERN AREAS.
HOWEVER...ONCE THE EXPECTED NOCTURNAL LLJ DEVELOPS IN RESPONSE TO
UPSTREAM PRESSURE FALLS...ANY REMAINING LOW CIGS SHOULD DISSIPATE
BY LATE TONIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EST SATURDAY FOR LMZ043-046.
&&
$$
SHORT TERM...JC
LONG TERM...MURPHY
AVIATION...JC
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1244 PM EST THU NOV 24 2011
.AVIATION.../18Z TAFS/
IFR CIGS WILL REMAIN IN PLACE FOR MOST OF THE DAY GIVEN TRAPPED LL
MOISTURE UNDER A STAUNCH INVERSION. SCOURING OF THIS CLOUD DECK IS
ONGOING ACROSS WESTERN IL AND THIS IS EXPECTED TO SLOWLY SPREAD
INTO THE AREA LATE THIS AFTERNOON AND EVENING PER NEGATIVE THETA-E
ADV INTO THE SATURATED CLOUD LAYER. HENCE...EXPECT A SW-NE IFR-
VFR TREND IN TAFS...ESP WESTERN HALF. THIS PROCESS MAY SEE A DELAY
GIVEN DIURNAL BL COOLING THIS EVENING...ESP EASTERN AREAS.
HOWEVER...ONCE THE EXPECTED NOCTURNAL LLJ DEVELOPS IN RESPONSE TO
UPSTREAM PRESSURE FALLS...ANY REMAINING LOW CIGS SHOULD DISSIPATE
BY LATE TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 1053 AM EST THU NOV 24 2011/
UPDATE...
STAUNCH LL INVERSION IN PLACE PER RAOB/TAMDAR ANALYSIS WITH WAA
REGIME ONGOING ACROSS THE FA. LL MOISTURE REMAINS TRAPPED BELOW
THE INVERSION BASE...WHICH IS JUST ABOVE H95...AND INCREASING FLOW
WILL LIKELY BE TOO LITTLE TO SUPPORT MIX OUT OF STRATUS TODAY.
SATELLITE CONFIRMS STRATUS DECK STRETCHING BACK TO TX...AND GIVEN
LOW SUN ANGLE AND A RE-ENFORCING INVERSION PER WAA...HAVE UPDATED
SKY GRIDS TO HOLD CLOUDY MENTION THROUGH THE DAY. THE POTENTIAL
FOR A FEW BREAKS LINGERS ACROSS THE NW THIRD GIVEN THE INCREASED
POTENTIAL FOR TURBULENT BL TOP MIXING...ALBEIT SMALL ATTM.
OTHERWISE...EVEN WITH THE LACK OF STRONG INSOLATION TEMPS WILL
CONTINUE TO CLIMB THROUGH AFTERNOON GIVEN SIG WAA. HOWEVER...MOST
AREAS WILL FALL SHORT OF 50...SAVE THE NW WHERE THERMAL ADVECTION
WILL BE THE STRONGEST.
PREV DISCUSSION... /ISSUED 411 AM EST THU NOV 24 2011/
SHORT TERM...
AS FEARED...POTENTIAL WRINKLES IN TERMS OF STRATUS AND FOG CAME TO
FRUITION OVERNIGHT AND ARE CAUSE FOR SIGNIFICANT CHANGES TO SHORT
TERM FORECAST GRIDS. 11-3.9 MICRON SATELLITE IMAGE SHOWS LARGE AREA
OF STRATUS ACROSS THE MS AND OH RIVER VALLEY REGIONS AND QUICKLY
EXPANDING NORTHEAST ACROSS OUR AREA AS OF 08Z. 1000MB SW FLOW OF 5
TO 10 KNOTS AIDING IN MOVING STRATUS NORTHEAST. THE ENTIRE SHORT
TERM FORECAST HINGES ON WHAT THIS STRATUS DECK DOES OVER NEXT 24
HOURS AND HENCE THE SHORT TERM PROBLEM OF THE DAY.
NAM12 AND RUC HAVE SOME CLUE THAT STRATUS EXISTS BUT HRRR SEEMS TO
HAVE BEST HANDLE BY FAR. MOS GUIDANCE HAS NO CLUE WITH CLOUD COVER
CATEGORIES MAINLY CLEAR THROUGH THE PERIOD AND EVEN LAMP GUIDANCE AS
OF 08Z HAS NO INDICATION. THUS MOS TEMPS NOT CLOSE TODAY FOR
OPTIMISTIC 50S UNLESS CLOUD COVER ERODES QUICKLY WHICH IS DOUBTFUL
AT THIS TIME. NAM12 BUFKIT SOUNDINGS SHOW SATURATED SURFACE TO 1KFT
LAYER WITH STRONG INVERSION AND VERY DRY AIR ABOVE. WHILE YESTERDAYS
MODEL RUNS MIXED THE LOWER LEVELS...LATEST RUNS ARE MUCH STRONGER
WITH INVERSION AND SLIGHTLY DEEPER WITH MOIST LAYER LEADING TO
LITTLE MIXING UNTIL LATE AFTERNOON. LATEST HRRR LOW CLOUD PRODUCT
HAD STRATUS AREA NAILED AT INITIATION AND KEEPS IT LOCKED THROUGH
ITS VALID PERIOD WHICH IS MID AFTERNOON. HRRR 2M TEMPS ALSO REMAIN
IN UPPER 30S AND LOWER 40S THROUGH MID AFTERNOON. ALSO SOME CONCERN
FOR DRIZZLE FOR A FEW HOURS AFTER SUNRISE AS TURBULENT MIXING OF
SHALLOW CLOUD TOPS OFTEN LEADS TO PERIOD OF LIGHT
PRECIPITATION...ESPECIALLY WHEN SUB CLOUD LAYER IS MOIST WITH BR OR
FOG. HAVE ADDED A CHANCE FOR DRIZZLE TO ACCOUNT FOR THIS POSSIBILITY
THROUGH MID MORNING.
A LOOK BACK AT SATELLITE TRENDS ON WEDNESDAY REVEALED VERY LITTLE
MIXING OF STRATUS AND THUS CONCERNED FOR SIMILAR TREND TODAY INTO
TONIGHT. SUBTLE DIFFERENCE TODAY WILL BE INCREASING WINDS IN THE
1000-925MB LAYER... ESPECIALLY ABOVE 950MB WITH 40 TO 50 KNOTS
DEVELOPING LATE TONIGHT. HOWEVER...THIS WILL BE JUST ABOVE INVERSION
AND MAY NOT BE ENOUGH TO MIX OUT LOWER STRATUS DECK GIVEN STRONG
INVERSION IN PLACE. 1000MB WINDS LOOK TO INCREASE BUT ONLY IN THE 5
TO 15 KNOT RANGE WITH LIGHTER WINDS UPSTREAM WHERE STRATUS COULD
REDEVELOP AND AGAIN ADVECT BACK IN.
AFTER MUCH COLLABORATION HAVE OPTED FOR CLOUDY CONDITIONS THROUGH
EARLY AFTERNOON WITH A SUBTLE OPTIMISTIC TRANSITION TO PARTLY CLOUDY
MID TO LATE AFTERNOON. KEPT SKY COVER IN PARTLY CLOUDY RANGE TONIGHT
WITH UNCERTAINTY CONTINUING AS TO DEGREE OF REDEVELOPMENT IF WE
ACTUALLY DO BREAK OUT THIS AFTERNOON. STRONGER FLOW ON FRIDAY AHEAD
OF NEXT SYSTEM SUGGEST ANY REMAINING STRATUS WOULD MIX OUT MID TO
LATE MORNING.
TEMPS OBVIOUSLY WILL BE IMPACTED SIGNIFICANTLY WITH THIS STRATUS.
HAVE LOWERED HIGHS TODAY SEVERAL DEGREES BUT LIKELY NOT NEARLY
ENOUGH IF CLOUDS PERSIST ALL DAY. HAVE TO RESPECT PARTIAL CLEARING
IN AFTERNOON SO DID NOT GO AS LOW AS COLDEST MODEL BLENDS. 06Z NAM12
KEEPING TEMPS IN 30S ALL AREAS TODAY. MINS TONIGHT NOW HEAVILY
DEPENDENT ON ACTUAL MAX TEMPS TODAY BUT EXPECT LITTLE DROP OFF WITH
DECENT GRADIENT AND CLOUD POTENTIAL. KEPT TEMPS IN LOW TO MID 40S
TONIGHT. HIGHS ON FRIDAY STILL LOOK TO BE NEAR 60 WITH BETTER MIXING
BUT CONCERNS CONTINUE FOR LINGERING STRATUS IN THE MORNING.
LONG TERM.../SATURDAY THROUGH WEDNESDAY/
FEW SIG CHANGES TO LONG TERM WITH MODEL TURMOIL STILL ABUNDANT
THROUGH THE PERIOD. ARRIVAL OF TROUGH FROM THE WEST AND ASSOCIATED
PRECIP STILL NOT MUCH CLEARER WITH NAM/GFS SPREADING RAIN ACROSS THE
AREA MID MORNING WEST INTO AFTERNOON EAST VS ECMWF MORE QUICK
AFTERNOON ARRIVAL WEST TO EAST. THESE FASTER SOLUTIONS ALSO PUSHES
PRECIP OUT AFTER 6Z SUN IN WESTERN AREAS. THINK COMPROMISE STILL
NEEDED IN MODELS...MEANING GENERALLY SAME FORECAST FOR SAT/SAT NGT.
TEMPS STILL GOING TO BE TRICKY BUT WITH INCREASING MID/HIGH CLOUDS
THINK THEY WILL BE KEPT IN CHECK ESPECIALLY WEST. HAVE INCREASED SKY
COVER TO REFLECT FASTER CLOUD ARRIVAL.
ECMWF ONLY MODEL THAT STARTS PROGRESSIVE SUNDAY WITH GFS/GEFS/GEM
ALL SHOWING CLOSED UPPER LOW ACROSS THE GREAT LAKES /IN VARYING
LOCATIONS/. WITH TIME...ECMWF AND GEM CONTINUE A DEPICTION OF RAPID
DEEPENING OF UPPER LOW AND MAJOR TRANSLATION SOUTHWARD IN ENERGY.
GFS/GEFS HOLD WITH NORTHERN INFLUENCE BEING STRONGER. NEXT TROUGH
WILL MOVE INTO THE AREA MONDAY NIGHT INTO TUESDAY AND INTERACT WITH
CLOSED LOW WHEREVER IT MAY BE. THINK THERE WILL BE AT LEAST A
DECENT SHOT FOR PRECIP UNDER THE UPPER LOW WITH COOL NW FLOW ACROSS
THE LAKE AND SYNOPTIC MSTR STILL ACROSS THE AREA. IN
ADDITION...PIECE OF ENERGY SHOULD ROTATE ACROSS THE AREA ON SUNDAY.
WILL MAINTAIN MID RANGE CHC POPS FOR NOW WITH POSSIBLE INCREASE TO
LIKELY WITH TIME. BASED ON THERMAL PROFILES...HAVE OPTED TO THROW IN
MIX MENTION FOR THE DAY AS 1000-850 MB VALUES DROP TO NEAR OR BELOW
1300 M.
HAVE ONLY MADE MINOR TWEAKS TO POPS FROM CR INIT TO PLACE HIGHER
EMPHASIS ON PAST VS PRESENT WITH SLIGHTLY HIGHER POPS. WHILE AN
OUTLIER...IF ECMWF SOLUTION OF UPPER LOW EVENTUALLY WORKING NORTH
TOWARDS THE AREA MON NGT INTO TUES NGT BODES TRUE...COULD BE RATHER
WET. ECMWF HAS BEEN VERY VARIABLE OF LATE...BUT NO WORSE THAN SOME
OF THE OTHERS LEADING TO AT LEAST CONSIDERATION OF THE SCENARIO.
REGARDLESS OF SOLUTIONS...NORMAL TO BELOW NORMAL TEMPS WILL BE IN
STORE SUNDAY AND BEYOND.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR LMZ043-046.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION/UPDATE...JC
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1246 PM EST THU NOV 24 2011
LATEST UPDATE...AVIATION...
.SYNOPSIS...(400 AM EST THU NOV 24 2011)
THANKSGIVING DAY WILL SEE SOME CLOUDS MOVE IN WITH HIGHS IN THE
UPPER 40S. NO RAIN IS EXPECTED UNTIL THE WEEKEND WHEN A COLD FRONT
MOVES THROUGH. RAIN SHOWERS COULD MIX WITH WET SNOW BY SUNDAY NIGHT
AS COLDER AIR MOVES IN BEHIND THE COLD FRONT.
&&
.SHORT TERM...(400 AM EST THU NOV 24 2011)
(TODAY THROUGH SATURDAY)
FORECAST PROBLEMS IN THE NEAR TERM INCLUDE LOW CLOUDS AND POTENTIAL
IMPACT ON MAX TEMPS TODAY AND TIMING IN THE RAIN ON SATURDAY.
LOWERED MAXES FROM THE LOWER 50S TO UPPER 40S FOR TODAY AS SATELLITE
AND OBS SHOW AREA OF LOW STRATUS MOVING INTO THE WESTERN FORECAST
AREA ATTM. MAX TEMPS WERE HELD TO THE LOWER 40S ACROSS IOWA ON
WEDNESDAY AFTERNOON UNDER THESE CLOUDS.
00Z NAM RH PROFILES SHOW INVERSION SLOWLY LOWERING AND SUGGESTS
CLOUDS COULD BREAK UP THIS AFTERNOON...BUT LATEST RUC IS MORE
PESSIMISTIC AND WOULD MEAN A CLOUDY DAY AND MAXES PROBABLY HELD IN
THE MID 40S. STRATUS MAY HANG ON EVEN INTO TONIGHT AND POSSIBLE
FRIDAY MORNING BEFORE INCREASING WINDS AND MIXING SCOUR THEM OUT.
KEPT CHANCE POPS UP NORTH FOR FRIDAY NIGHT AS SOME ISENTROPIC ASCENT
AND MID LEVEL MOISTURE IS AVAILABLE. THE STEADIER RAIN SHOULD
HOLD OFF UNTIL AFTER 12Z SATURDAY AND POSSIBLY UNTIL 00Z SUNDAY IF
THE SLOWER EURO SOLUTION PANS OUT...AS DIGGING SHORTWAVE TROUGH
APPROACHES AND COUPLED JET ALONG WITH DEEP MOISTURE MOVES IN.
&&
.LONG TERM...(400 AM EST THU NOV 24 2011)
(SATURDAY NIGHT THROUGH WEDNESDAY)
THE MID RANGE MODELS CONTINUE TO SHOW DIFFERENCES IN THE LONG TERM.
THERE IS GOOD AGREEMENT ON THE SYSTEM SATURDAY NIGHT THROUGH SUNDAY
NIGHT. HOWEVER... CONFIDENCE IS LOWER FOR THE POTENTIAL
PRECIPITATION WITH A SYSTEM MONDAY NIGHT INTO WEDNESDAY. IN FACT...
THE ECMWF SHOWS THE WEATHER ASSOCIATED WITH A CUT OFF LOW SWEEPING
BY TO THE SOUTHEAST OF THE AREA. MEANWHILE... THE GFS HAS NO CUTOFF
LOW AND MOVES A WEAK CANADIAN WAVE BY TO THE NORTH. THEREFORE...
CONFIDENCE AND THE POPS ARE LOWER AFTER MONDAY AND SOME PERIODS HAVE
BEEN DRIED OUT. THE PRECIPITATION... IF IT OCCURS... COULD BE
RAIN... SNOW OR A RAIN/SNOW MIX.
TEMPERATURES WILL BE A LITTLE ABOVE NORMAL THROUGH THE WEEKEND. THEY
WILL BE AROUND NORMAL NEXT WEEK. NORMAL HIGHS THIS TIME OF YEAR ARE
AROUND 40 DEGREES AND NORMAL LOWS ARE IN THE UPPER 20S.
&&
.AVIATION...(1246 PM EST THU NOV 24 2011)
A TEMPERATURE INVERSION WAS HOLDING IN THE LOW CLOUDS THIS
AFTERNOON. CEILINGS WERE MAINLY IFR ALONG AND SOUTH OF I-96...WITH
MVFR TO THE NORTH. DRYING IN THE LOW LEVELS SLOWLY OCCURS FROM THE
SW AND THIS IS EVIDENT WITH THE CLEARING THAT WAS OCCURRING ACROSS
CENTRAL IL AS OF 17Z. FEEL WE WILL SEE SOME IMPROVEMENT INTO THE
EVENING AND OVERNIGHT AS THIS DRIER LOW LEVEL AIR ARRIVES. THE I-94
TAF SITES SHOULD IMPROVE DURING THE 00-04Z TIME FRAME. WHILE THE
I-96 AREA SHOULD IMPROVE 03-07Z. SOME LOW CLOUDS COULD LINGER EVEN
LONGER ALONG THE LAKE MICHIGAN SHORE. ONCE THE CLOUDS BREAK OUT VFR
CONDITIONS SHOULD PREVAIL THROUGH MID DAY FRI. HOWEVER...SW WINDS
SHOULD GUST TO AROUND 25 KTS AFTER 14Z FRI.
&&
.MARINE...(400 AM EST THU NOV 24 2011)
ISSUED A SMALL CRAFT ADVISORY FOR TODAY THROUGH FRIDAY NIGHT AS A
TIGHTENING PRESSURE GRADIENT WILL BRING WEST TO SOUTHWEST WINDS
GUSTING TO 25 KNOTS AND WAVES BUILDING ABOVE FOUR FEET.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY THROUGH FRIDAY NIGHT.
&&
$$
SYNOPSIS: OSTUNO
SHORT TERM: OSTUNO
LONG TERM: 63
AVIATION: JK
MARINE: OSTUNO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1230 PM EST THU NOV 24 2011
UPDATED AVIATION DISCUSSION FOR 18Z TAFS
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL RIDGE
ACROSS THE CNTRL CONUS. A SHORTWAVE TROUGH OFFSHORE FROM THE PAC NW
WILL HELP AMPLIFY A PROGRESSIVE MID LEVEL TROUGH THAT WILL MOVE INTO
THE PLAINS TONIGHT AND TO THE WRN GREAT LAKES BY LATE SAT. AT THE
SFC...SSW FLOW PREVAILED OVER THE REGION BTWN LOW PRES INTO SRN
MANITOBA AND A RIDGE OVER THE OH AND LOWER MS VALLEY. 11-3.9 IR LOOP
INDICATED LOW CLOUDS ALONG THE WI BORDER FROM IWD TO IMT AND OVER
MUCH OF THE EAST HALF OF THE CWA. OTHERWISE...WAA HIGH CLOUDS WERE
SPREADING FROM NRN MN INTO WRN UPPER MI.
&&
.DISCUSSION...
TODAY AND TONIGHT...VERY MILD AIR HAS SPREAD OVER THE COLDER AIR NEAR THE
SURFACE CREATING A STRONG INVERSION AS 00Z KGRB SOUNDING SHOWED 925
MB TEMP AT 9C. MAX TEMPS WILL DEPEND ON HOW QUICKLY ANY MORNING
FOG/STRATUS BURNS OFF AND THE MIXING DEPTH. EVEN WITH LATE NOV SUN
ANGLE AND A VERY STABLE SFC-900 MB LAYER...EXPECT ENOUGH MIXING FOR
TEMPS ABOVE CONS GUIDANCE VALUES...CLIMBING INTO THE UPPER 40S TO
AROUND 50. AREAS WITH DOWNSLOPE SW WINDS COULD SEE READINGS INTO AT
LEAST THE MID 50S. SOUTHWEST WINDS WILL HELP KEEP MIN TEMPS WELL
ABOVE NORMAL TONIGHT WITH READINGS ONLY DROPPING INT0 THE UPPER 30S
TO AROUND 40.
FRIDAY...INCREASING CLOUDS WILL LIMIT POTENTIAL FOR HIGHER TEMPS BUT
WITH THE MILD AIRMASS IN PLACE TEMPS SHOULD STILL CLIMB INTO THE MID
AND UPPER 40S.
LATE FRIDAY NIGHT INTO SATURDAY...THE GFS/ECMWF WERE IN REASONABLE
AGREEMENT WITH THE PROGRESSIVE MID LEVEL TROUGH AND THE SFC LOW
DEVELOPING OVER THE PLAINS AND MOVING INTO TO NEAR IMT BY 18Z SAT.
STRONG MOISTURE INFLOW WITH PWAT VALUES TO 0.75 INCH AND 295K-300K
ISENTROPIC LIFT AHEAD OF THE LOW SUPPORT LIKELY RAIN CHANCES OVER THE
AREA...WITH THE HEAVIEST PCPN MAINLY IN THE MORNING. CAA IN THE WAKE
OF THE LOW ALONG WILL BRING A CHANGEOVER TO SNOW AND LAKE ENHANCED
SNOW LATE SAT NIGHT INTO SUN MORNING AS 850 MB TEMPS DROP TO AROUND
-8C.
MODEL DIFFERENCES EMERGE THAT IMPACT THE SNOWFALL POTENTIAL OVER WRN
UPPER MI. THE GFS CLOSES OFF A MID LEVEL LOW WHICH KEEPS THE DEEPER
MOISTURE AND LIFT ALONG WITH STRONGER CYCLONIC CIRCULATION INTO THE
WRN CWA. THE ECMWF AND CANADIAN GLOBAL GEM WITH A MORE PROGRESSIVE
MID LEVEL TROUGH WOULD BRING THE DRIER AIR IN FASTER WITH REDUCED
CHANCES FOR ACCUMULATING SNOW. UNTIL THE MODELS COME INTO BETTER
AGREEMENT A COMPROMISE WAS USED WHICH SUGGEST THE POTENTIAL FOR
SEVERAL INCHES OF SNOW OVER THE WEST. WITH ONLY MARGINALLY COLD AIR
INTO THE REGION...ANY ACCUMULATING SNOW WILL DIMINISH RAPIDLY AS THE
DEEPER MOISTURE AND WEAK LIFT MOVE OFF TO THE EAST SUNDAY.
MONDAY THROUGH WED...THE GFS...ECMWF AND MAJORITY OF ENSEMBLE
MEMBERS NOW SUGGEST THAT THE NRN STREAM WILL PREVAIL ACROSS THE NRN
LAKES AND THAT EITHER NO CUTOFF WILL DEVELOP TO THE SOUTH OR IT WILL
REMAIN FAR ENOUGH AWAY TO HAVE LITTLE IMPACT ON THE WEATHER OVER THE
REGION. SFC AND MID LEVEL RIDGING INTO THE AREA MON ALONG WITH
SIGNIFICANT WAA WILL KEEP THE AREA DRY WITH SW WINDS AND TEMPS
CLIMBING TO NEAR 40F. LOW CONFIDENCE BY TUE/WED BUT MODELS SUGGEST
POTENTIAL FOR A A COLD FROPA BEHIND A NRN STREAM SHRTWV COULD BRING
ENOUGH COLD AIR INTO THE AREA FOR SOME LAKE EFFECT SNOW.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
LOW CLOUDS/VSBY EARLY THIS AFTN AT KSAW...OTHERWISE SHOULD BE QUIET INTO
EARLY EVENING AT ALL TAF SITES WITH JUST SOME GUSTY SW WINDS. AS
SOUTHWEST WINDS PUSH MOISTURE BACK INTO THE REGION TONIGHT AND AS
INVERSION STRENGTHENS...EXPECT LOW CLOUDS TO REDEVELOP AND PUSH
INTO THE TAF SITES. GREATEST CHANCE OF LOW CLOUDS FORMING TONIGHT
WILL BE AT KSAW...BUT THERE SHOULD BE IFR/LOWER MVFR CLOUDS AT ALL
SITES BY MID MORNING ON FRIDAY. LLWS IS EXPECTED AGAIN TONIGHT AHEAD
OF AN APPROACHING SURFACE TROUGH THAT MOVES THROUGH ON FRIDAY.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
SOUTHWESTERLY WINDS WILL CONTINUE TODAY INTO TONIGHT...ALTHOUGH A
STRENGTHENING INVERSION WILL LIKELY KEEP WINDS FROM GUSTING OVER
30KTS. ON FRIDAY...A WEAK SFC TROUGH WILL STALL OVER LK SUPERIOR AND
DIMINISH THE WINDS BELOW 20KTS. A LOW IS THEN EXPECTED TO MOVE OUT
OF THE CENTRAL PLAINS AND FOLLOW THE TROUGH OVER EASTERN LAKE
SUPERIOR ON SATURDAY. AS THE LOW SHIFTS NORTHEAST ON SATURDAY
NIGHT...NORTH TO NORTHWEST GALE FORCE GUSTS TO 35KTS ARE POSSIBLE
OVER CENTRAL/EASTERN LAKE SUPERIOR. HIGH PRESSURE RIDGE WILL BUILD
OVER LAKE SUPERIOR ON SUNDAY NIGHT AND LEAD TO DECREASING
WINDS...BEFORE THEY PICK UP AGAIN OUT OF THE SOUTHWEST ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...JLA
MARINE...SRF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
119 PM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE REGION TODAY...AND
REMAIN OVER THE NORTHEAST THROUGH THE UPCOMING WEEKEND. A FRONTAL
BOUNDARY APPROACHES THE AREA LATE SUNDAY INTO MONDAY. A LOW
MOVING ALONG THIS FRONT WILL KEEP PRECIPITATION OVER THE NORTH
COUNTRY INTO TUESDAY BEFORE HIGH PRESSURE BUILDS INTO THE AREA
FOR MIDWEEK NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 1241 PM EST THURSDAY...STRATUS DECK WILL HOLD TODAY GIVEN
STRONG INVERSION 950-850MB LAYER PER 12Z ALB SOUNDING AND
AVAILABLE RUC FCST SOUNDINGS. THIS WILL LIKELY ALSO KEEP AFTN
TEMPERATURES SLIGHTLY BELOW MOS VALUES. WINDS WILL GRADUALLY
BECOME S-SW 5-10 MPH...MAINLY WEST OF THE GREEN MTNS...WITH WINDS
LIGHT/VARIABLE EAST OF THE GREENS. COULD BE A BRIEF FLURRY OR
TWO...BUT SHALLOW NATURE OF CLOUD DECK AND BUILDING HEIGHTS ALOFT
WILL GENERALLY PRECLUDE ANY PCPN THRU REMAINDER OF TODAY OR
TONIGHT.
FOR TONIGHT...CLOUDS REMAIN TRICKY. LIKELY TO SEE OVERCAST REMAIN
MUCH OF THE NIGHT. STRENGTHENING S-SW FLOW TOWARD DAYBREAK SHOULD
HELP TO EVENTUALLY ADVECT THE STRATUS AWAY FROM SW-NE...BUT COULD
HOLD OFF UNTIL AFTER 12Z. WINDS OVERNIGHT REMAIN 5-10 MPH RANGE
WITH PREVAILING GRADIENT FLOW...ESPECIALLY IN THE WIDER VALLEY
LOCATIONS. WINDS WILL APPROACH 20 KTS ON LAKE CHAMPLAIN AFTER
MIDNIGHT. CLOUDS AND WIND WILL HELP HOLD LOW TEMPERATURES MAINLY
IN THE 30S...EXCEPT LOCALLY LOW-MID 20S FOR THE FAR NERN PORTIONS
OF VERMONT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
AS OF 227 AM EST THURSDAY...HIGH PRESSURE SOUTH OF THE CWA ON
FRIDAY...PUSHING OFFSHORE DURING THE DAY SATURDAY. W/ CWA
EXPECTED TO BE UNDER WSW FLOW...WAA WILL BRING IN INCR HIGH TEMPS
OVER THE TWO-DAY PERIOD. W/ 850/925 TEMPS NEAR +4C TO +8C BOTH
DAYS HIGHS NEAR 50F ARE NOT OUT OF THE QUESTION. HAVE GONE A FEW
DEGREES ABV NORMALS/MDL GUIDANCE AS DO NOT SEE ENOUGH COOLING
OVERNGT THAT THE NUMBERS SHOW WITH CWA STILL UNDER WAA FROM THE
WSW. MDLS DO HINT AT THE POSSIBILITY OF INCR CLDS DURING THE DAY
SATURDAY FOR N ZONES/ST LAW VALLEY DUE TO WK WARM FRNT THAT MAY
ULTIMATELY INHIBIT SUNSHINE THERE. OTHER WX ISSUE TO BE OF
CONCERN WILL BE GUST POTENTIAL OVER N NY DUE TO MID LEVEL JET
NEAR CANADIAN BORDER. BUFKIT SUGGEST GUSTS TO NEAR 30 MPH IF
MIXING OCCURS SO WILL PUT IN MENTION...OTHERWISE...CWA WILL SEE
FAIRLY NICE 2-DAY STRETCH OF WX FOR LATE NOVEMBER.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 405 AM EST THURSDAY...DRY CONDITIONS WILL CONTINUE SATURDAY
NIGHT INTO EARLY SUNDAY AS WE REMAIN UNDER INFLUENCE OF HIGH
PRESSURE...WHICH WILL BE MOVING FURTHER OFFSHORE. CHANCES FOR
RAIN SHOWERS INCREASE DURING THE DAY ON SUNDAY WITH LOW PRESSURE
LIFTING NORTH OF THE REGION AND ASSOCIATED COLD FRONT APPROACHING
FROM THE GREAT LAKES/OHIO VALLEY. BUT ECMWF AND GFS CONTINUE TO
OFFER SIGNIFICANTLY DIFFERENT SOLUTIONS FOR THE REMAINDER OF THE
PERIOD. GFS DEPICTING FULL LATITUDE TROUGH...WITH SURFACE COLD
FRONT MOVING SLOWLY ACROSS THE NORTHEAST. THIS SCENARIO WOULD
RESULT IN SOME SIGNIFICANT RAINFALL ACROSS THE AREA SUNDAY NIGHT
INTO MONDAY WITH GOOD FEED OF MOISTURE OFF THE ATLANTIC. THIS
SYSTEM THEN GETS PUSHED TO THE EAST BY SERIES OF POTENT NORTHERN
STREAM SHORTWAVES WHICH WOULD TRAVERSE THE REGION TUESDAY THROUGH
THURSDAY...ACCOMPANIED BY SCATTERED RAIN/SNOW SHOWERS. ECMWF
BRINGS INITIAL SHORTWAVE AND COLD FRONT ACROSS THE AREA BY
MONDAY. SOUTHERN STREAM SHORTWAVE THEN LIFTS NORTHEAST FROM THE
MISSISSIPPI VALLEY BRINGING POSSIBILITY OF MORE WIDESPREAD
RAINFALL FOR TUESDAY INTO WEDNESDAY. WITH SUCH A WIDE DISPARITY
BETWEEN THE MODELS...FORECASTER CONFIDENCE FOR MUCH OF THE
EXTENDED PERIOD IS RATHER LOW. BEST CHANCE FOR RAINFALL ON ALL OF
THE MODELS APPEARS TO BE SUNDAY NIGHT. FOR THE REST OF THE
PERIOD...HAVE GONE WITH FORECAST OF MAINLY CLOUDY WITH A CHANCE
OF SHOWERS. PRECIPITATION TYPE RAIN THROUGH MONDAY...BUT SOME
SNOW SHOWERS POSSIBLE THEREAFTER OVER THE HIGHER TERRAIN AS TEMPS
RETURN TO MORE SEASONABLE LEVELS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
THROUGH 18Z FRIDAY...ABUNDANT LOW-LEVEL MOISTURE CONTINUES TO
REMAIN OVER THE REGION THIS AFTERNOON WITH WIDESPREAD MVFR AND
LOCAL IFR CEILINGS. HIGH PRESSURE WILL CONTINUE TO BUILD
EAST...THOUGH DO NOT FORESEE MUCH CLEARING TILL AFTER SUNRISE
FRIDAY MORNING. WINDS WILL PICK UP AT THAT TIME AND SKIES WILL
FINALLY MIX OUT. SOUTH TO SOUTHWEST AT 5 TO 15 KTS WILL CONTINUE
THROUGH THE PERIOD.
OUTLOOK 12Z FRIDAY THROUGH TUESDAY...VFR CONDITIONS EXPECTED
THROUGH SUNDAY AS A RIDGE OF HIGH PRESSURE PASSES SOUTH OF THE
REGION. SHOWERS WITH MVFR/IFR CONDITIONS EXPECTED SUNDAY NIGHT
AND MONDAY AS A FRONTAL SYSTEM MOVES SLOWLY ACROSS THE AREA. VFR
CONDITIONS WILL RETURN FOR TUESDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...JN
LONG TERM...RJS
AVIATION...NEILES
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1245 PM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE REGION TODAY...AND
REMAIN OVER THE NORTHEAST THROUGH THE UPCOMING WEEKEND. A FRONTAL
BOUNDARY APPROACHES THE AREA LATE SUNDAY INTO MONDAY. A LOW MOVING
ALONG THIS FRONT WILL KEEP PRECIPITATION OVER THE NORTH COUNTRY
INTO TUESDAY BEFORE HIGH PRESSURE BUILDS INTO THE AREA FOR MIDWEEK
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 1241 PM EST THURSDAY...STRATUS DECK WILL HOLD TODAY GIVEN
STRONG INVERSION 950-850MB LAYER PER 12Z ALB SOUNDING AND
AVAILABLE RUC FCST SOUNDINGS. THIS WILL LIKELY ALSO KEEP AFTN
TEMPERATURES SLIGHTLY BELOW MOS VALUES. WINDS WILL GRADUALLY
BECOME S-SW 5-10 MPH...MAINLY WEST OF THE GREEN MTNS...WITH WINDS
LIGHT/VARIABLE EAST OF THE GREENS. COULD BE A BRIEF FLURRY OR
TWO...BUT SHALLOW NATURE OF CLOUD DECK AND BUILDING HEIGHTS ALOFT
WILL GENERALLY PRECLUDE ANY PCPN THRU REMAINDER OF TODAY OR
TONIGHT.
FOR TONIGHT...CLOUDS REMAIN TRICKY. LIKELY TO SEE OVERCAST REMAIN
MUCH OF THE NIGHT. STRENGTHENING S-SW FLOW TOWARD DAYBREAK SHOULD HELP
TO EVENTUALLY ADVECT THE STRATUS AWAY FROM SW-NE...BUT COULD HOLD
OFF UNTIL AFTER 12Z. WINDS OVERNIGHT REMAIN 5-10 MPH RANGE WITH
PREVAILING GRADIENT FLOW...ESPECIALLY IN THE WIDER VALLEY
LOCATIONS. WINDS WILL APPROACH 20 KTS ON LAKE CHAMPLAIN AFTER
MIDNIGHT. CLOUDS AND WIND WILL HELP HOLD LOW TEMPERATURES MAINLY
IN THE 30S...EXCEPT LOCALLY LOW-MID 20S FOR THE FAR NERN PORTIONS
OF VERMONT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
AS OF 227 AM EST THURSDAY...HIGH PRESSURE SOUTH OF THE CWA ON
FRIDAY...PUSHING OFFSHORE DURING THE DAY SATURDAY. W/ CWA EXPECTED
TO BE UNDER WSW FLOW...WAA WILL BRING IN INCR HIGH TEMPS OVER THE
TWO-DAY PERIOD. W/ 850/925 TEMPS NEAR +4C TO +8C BOTH DAYS HIGHS
NEAR 50F ARE NOT OUT OF THE QUESTION. HAVE GONE A FEW DEGREES ABV
NORMALS/MDL GUIDANCE AS DO NOT SEE ENOUGH COOLING OVERNGT THAT THE
NUMBERS SHOW WITH CWA STILL UNDER WAA FROM THE WSW. MDLS DO HINT AT
THE POSSIBILITY OF INCR CLDS DURING THE DAY SATURDAY FOR N
ZONES/ST LAW VALLEY DUE TO WK WARM FRNT THAT MAY ULTIMATELY
INHIBIT SUNSHINE THERE. OTHER WX ISSUE TO BE OF CONCERN WILL BE
GUST POTENTIAL OVER N NY DUE TO MID LEVEL JET NEAR CANADIAN
BORDER. BUFKIT SUGGEST GUSTS TO NEAR 30 MPH IF MIXING OCCURS SO
WILL PUT IN MENTION...OTHERWISE...CWA WILL SEE FAIRLY NICE 2-DAY
STRETCH OF WX FOR LATE NOVEMBER.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 405 AM EST THURSDAY...DRY CONDITIONS WILL CONTINUE SATURDAY
NIGHT INTO EARLY SUNDAY AS WE REMAIN UNDER INFLUENCE OF HIGH
PRESSURE...WHICH WILL BE MOVING FURTHER OFFSHORE. CHANCES FOR RAIN
SHOWERS INCREASE DURING THE DAY ON SUNDAY WITH LOW PRESSURE LIFTING
NORTH OF THE REGION AND ASSOCIATED COLD FRONT APPROACHING FROM THE
GREAT LAKES/OHIO VALLEY. BUT ECMWF AND GFS CONTINUE TO OFFER
SIGNIFICANTLY DIFFERENT SOLUTIONS FOR THE REMAINDER OF THE PERIOD.
GFS DEPICTING FULL LATITUDE TROUGH...WITH SURFACE COLD FRONT MOVING
SLOWLY ACROSS THE NORTHEAST. THIS SCENARIO WOULD RESULT IN SOME
SIGNIFICANT RAINFALL ACROSS THE AREA SUNDAY NIGHT INTO MONDAY WITH
GOOD FEED OF MOISTURE OFF THE ATLANTIC. THIS SYSTEM THEN GETS PUSHED
TO THE EAST BY SERIES OF POTENT NORTHERN STREAM SHORTWAVES WHICH
WOULD TRAVERSE THE REGION TUESDAY THROUGH THURSDAY...ACCOMPANIED BY
SCATTERED RAIN/SNOW SHOWERS. ECMWF BRINGS INITIAL SHORTWAVE AND
COLD FRONT ACROSS THE AREA BY MONDAY. SOUTHERN STREAM SHORTWAVE
THEN LIFTS NORTHEAST FROM THE MISSISSIPPI VALLEY BRINGING
POSSIBILITY OF MORE WIDESPREAD RAINFALL FOR TUESDAY INTO WEDNESDAY.
WITH SUCH A WIDE DISPARITY BETWEEN THE MODELS...FORECASTER
CONFIDENCE FOR MUCH OF THE EXTENDED PERIOD IS RATHER LOW. BEST
CHANCE FOR RAINFALL ON ALL OF THE MODELS APPEARS TO BE SUNDAY
NIGHT. FOR THE REST OF THE PERIOD...HAVE GONE WITH FORECAST OF MAINLY
CLOUDY WITH A CHANCE OF SHOWERS. PRECIPITATION TYPE RAIN THROUGH
MONDAY...BUT SOME SNOW SHOWERS POSSIBLE THEREAFTER OVER THE HIGHER
TERRAIN AS TEMPS RETURN TO MORE SEASONABLE LEVELS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
THROUGH 12Z FRIDAY...ABUNDANT LOW-LEVEL MOISTURE WILL REMAIN OVER
THE REGION THIS MORNING WITH WIDESPREAD MVFR AND LOCAL IFR
CEILINGS. SLOW IMPROVEMENT AS HIGH PRESSURE BUILDS EAST FROM THE
OHIO VALLEY. BY 16Z ALL TAF SITES EXPECTED TO BE MVFR...WITH A
TREND TO VFR BY 19Z. EXCEPTIONS WILL BE KSLK/KMSS WHERE MVFR CIGS
MAY PERSIST THROUGH THE PERIOD. LIGHT AND VARIABLE WINDS WILL
BECOME SOUTH TO SOUTHWEST AT 5 TO 15 KTS TODAY.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...VFR CONDITIONS EXPECTED THROUGH
SUNDAY AS A RIDGE OF HIGH PRESSURE PASSES SOUTH OF THE REGION.
SHOWERS WITH MVFR/IFR CONDITIONS EXPECTED SUNDAY NIGHT AND MONDAY
AS A FRONTAL SYSTEM MOVES SLOWLY ACROSS THE AREA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JN
NEAR TERM...BANACOS
SHORT TERM...JN
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1243 PM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE A DRY STRETCH OF WEATHER THROUGH
SATURDAY ALONG WITH MODERATING TEMPERATURES. BY SUNDAY, A COLD
FRONT WILL BRING SCATTERED SHOWERS TO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE. TOUCHY CLOUD FORECAST TODAY...WITH LOW LEVEL CLOUDS
IN WESTERN NY AND ALSO MOHAWK VALLEY AND PARTS OF THE
CATSKILLS...VERY POORLY RESOLVED BY THE MODELS. HIGH RES MODELS
HAVE STARTED TO CATCH UP...THOUGH RIC MODEL OVERCOMPENSATING.
BASED ON HR RR DEPICTION OF CLOUD COVER...I BRING MORE CLOUDS BACK
GENERALLY ALONG AND NORTH OF I-90 CORRIDOR THIS AFTERNOON AND
PARTS OF WESTERN FINGER LAKES REGION...WHERE INVERSION IS MORE
RETAINED. DRY POCKET WITH SUNSHINE IN BETWEEN...KEEPS THINGS MIXED
ENOUGH WITH DISSIPATION OF INVERSION...TO PREVENT CLOUDS FROM CREEPING
EASTWARD. TEMPERATURES ALSO ADJUSTED SLIGHTLY LOWER WHERE MORE
CLOUDS ARE NOW EXPECTED.
LOOKING INTO TONIGHT...EXPECTING CLOUDS TO CONTINUE TO BE STUCK
OVER PARTS OF WESTERN MOHAWK VALLEY. MODELS CURRENTLY NOT
SUGGESTING ENOUGH LOW LEVEL MOISTURE FOR CLOUDS OVER REMAINDER OF
AREA...THOUGH THIS WILL HAVE TO MONITORED SINCE THEY PERFORMED
POORLY UPSTREAM FOR LAST NIGHT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
FRIDAY THROUGH SATURDAY...A BROAD UPPER LEVEL RIDGE WILL BUILD
OVER THE NORTHEAST AS AFC HIGH PRES IN THE MID ATLANTIC PROVIDES A
MODERATING SOUTHWEST FLOW. LATE FRIDAY NIGHT INTO SATURDAY, LOW
PRES OVER THE UPPER GREAT LAKES WITH WARM FRONT STRETCHING ACROSS
NEARBY SOUTHERN ONTARIO WILL PRODUCE MORE CLOUD COVER. ANY THREAT
OF PRECIP WILL REMAIN WELL NORTH OF REGION JUST SOME MID CLOUDS
DUE TO MID LEVEL WARMING BUT STILL PARTLY CLOUDY.
MAX TEMPS FRIDAY/SATURDAY WILL GENERALLY RANGE IN THE MID TO UPPER
50S WITH THE NORMALLY WARMER AREAS NEAR 60.
SATURDAY NIGHT...AN APPROACHING COLD FRONT FROM THE WESTERN LAKES
WILL BE IN THE VICINITY OF EXTREME WESTERN NEW YORK BY 12Z
SUNDAY. WILL CONTINUE WITH SLIGHT CHC POPS FOR RAIN SHOWERS LATE
SATURDAY NIGHT OVER THE FINGER LAKES REGION AND CENTRAL SOUTHERN
TIER.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MAIN FOCUS IN THE MEDIUM RNG IS THE AMPLIFYING TROF WHICH IS
FORECAST TO MOV INTO THE CNTRL AND THE ERN U.S. EARLY NXT WEEK.
THERE ARE SIG DIFFS IN THE MDLS W/RESPECT TO TIMING...PCPN
AMTS...AND NRN/SRN STREAM INTERACTION. GFS PAINTS A POTNL FLOOD
SCENARIO WITH SRN PORTION OF THE TROF CUTTING OFF THEN LIFTING
NEWD...WITH +RA ACRS THE FSCT AREA SUN NGT INTO MONDAY ALONG AN
INVERTED TROF. THE EURO SHOWS LESS INTERACTION BETWEEN NRN AND SRN
STREAMS...BUT STILL SHOWS RAIN WORKING NWD INTO THE RGN LATE MON
NGT INTO TUE...BUT THE HEAVIEST PCPN IS SHUNTED OFF TO OUR
SOUTHEAST. GIVEN THESE DIFFS...WE LEANED HEAVILY ON HPC GUIDANCE
FOR THE MEDIUM RNG..WHICH PAINTS AN UNSETTLED PICTURE INTO
MIDWEEK.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
MVFR CIGS PERSIST AT SYR AND RME AT 1230 PM WITH SKC ELSEWHERE.
XPCT THE SRN PERIPHERY OF THE MVFR CIGS TO FLIRT WITH SYR INTO THE
EARLY EVNG HRS...WITH MAINLY SKC AFTERWARDS. AT RME...MVFR CIGS
ARE XPCTD TO PERSIST INTO THE OVRNGT HRS...WITH PSBLTY OF IFR CIGS
LATER TNGT IN MOIST WRLY FLOW. OTRW XPCT SKC AT OTHER SITES. AT
ELM...POTNL FOR DENSE VLY FOG DOES NOT LOOK AS FVRBL DUE TO INCRSD
LOW LVL WINDS...BUT TD`S THERE ARE IN THE M30S AND WITH MIN TEMPS
FCST TO BE BLO THE CROSSOVER TEMP...WE COULD SEE SOME RESTRICTIONS
THERE. FOR NOW JUST INDICATED PTNL FOR MVFR VSBY`S LATE. MAINLY
SKC ON FRI...XCPT FOR SOME LINGERING MVFR AT RME INTO MID MRNG.
WINDS THIS AFTN BECMG MORE W TO SW 10-15 KTS WITH G20...SWLY 5-10
KTS TNGT AND SW 10-20 KTS ON FRI.
OUTLOOK...
FRI THROUGH SUN...VFR.
SUN NGT/MON...IFR/MVFR IN RAIN.
MON NGT/TUE...PATCHY MVFR IN SCT -SHRA/-SHSN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP/RRM
NEAR TERM...MDP
SHORT TERM...RRM
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1226 PM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE RIDGE WILL KEEP LOW CLOUDS AND COOL AIR LOCKED IN
PLACE OVER MUCH OF THE REGION TODAY AND TONIGHT. THE RIDGE WILL
SLIDE EASTWARD AND BRING SOUTHERLY FLOW AND A WARMING TREND FOR
FRIDAY AND SATURDAY. BY SATURDAY NIGHT...AN APPROACHING COLD FRONT
WILL INCREASE CLOUD COVER AND CHANCES FOR PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
IT WILL BE A DIFFICULT CLOUD AND TEMPERATURE FORECAST FOR THIS
AFTERNOON.
VISIBLE SATELLITE IMAGERY CONTINUED TO SHOW AN EXPANSIVE AREA OF
STRATUS ACRS THE FORECAST AREA. THE EXCEPTION WAS OVER NE OHIO AND
TO OUR SOUTHEAST OVER EASTERN KENTUCKY AND WESTERN WEST VIRGINIA
WHERE STRATUS WAS ERODING AWAY AT THE STRATUS/CLEAR SKY INTERFACE.
THE RUC MODEL HAS BEEN HANDLING THE LOW LEVEL MOISTURE THE BEST.
HOWEVER...NO MODEL IS GOING TO CAPTURE THE AMOUNT OF ERODING THAT
MAY OCCUR TO OUR EAST/SOUTHEAST THIS AFTERNOON. BASED ON EROSION
TRENDS...HAVE ALLOWED SKIES TO BECOME PARTLY CLOUDY/MOSTLY SUNNY
IN OUR SOUTHEASTERN/SOUTHERN AREAS. WE SHOULD KNOW BY 3 TO 4 PM
HOW FAR EROSION TAKES PLACE AND HOW THIS WILL AFFECT TONIGHTS SKY
CONDITION AND OVERNIGHT LOWS. HAVE RAISED TEMPS SLIGHTLY SE/S TO
AROUND 50 WITH MORE INSOLATION POSSIBLE. OTHERWISE...THE MAJORITY
OF THE REGION WILL HAVE HIGHS IN THE MID 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
HIGH PRESSURE WILL GRADUALLY SHIFT EASTWARD TOWARD THE MID
ATLANTIC TONIGHT. BIGGEST DILEMMA OVERNIGHT WILL BE SKY CONDITION
AND OVERNIGHT LOWS. NAM-WRF AND GFS HAVE NOT HANDLED THE CURRENT
LOW LEVEL STRATUS AND THUS DO NOT HAVE FULL CONFIDENCE IN ITS
RH/MODEL SOUNDING SOLUTIONS WHERE INDICATE A CLEARING TREND FROM
SOUTH TO NORTH OVERNIGHT. THAT BEING SAID...CURRENT THINKING IS
THAT WHERE CLOUDS STAY SOCKED IN THROUGH THE DAY...THEY WILL
LIKELY REMAIN SO OVERNIGHT. HOWEVER...IT IS STILL POSSIBLE THAT
SOME DRIER AIR MAY PUSH NORTHWARD IN THE BOUNDARY LAYER. THUS...IT
IS A VERY DIFFICULT FORECAST TO PINPOINT CLOUDY TO CLEAR AND
WHETHER AREAS THAT CLEAR MAY SEE VERY LOW STRATUS FORM AGAIN.
ATTM...HAVE KEPT WEST CENTRAL OHIO...THE WHITEWATER/MIAMI VALLEYS
AND MUCH OF CENTRAL OHIO CLOUDY WHILE LEAVING SRN/SERN LOCATIONS
IN THE PARTLY CLOUDY/MOSTLY CLEAR REGIME. OVERNIGHT LOWS WILL BE
CLOUD DEPENDENT...THUS THEY SHOULD BE WARMEST ACRS THE NW WHERE
CLOUDS/WINDS WILL KEEP TEMPS FROM FALLING TOO MUCH.
FRIDAY THROUGH FRIDAY NIGHT...SOUTHERLY FLOW WILL BRING WARMER
TEMPERATURES ACROSS OUR AREA. CLOUDS ON FRIDAY SHOULD ERODE
AWAY..LEAVING MOSTLY SUNNY SKIES BY FRIDAY AFTERNOON. SUNSHINE AND
SOUTHERLY FLOW THIS WILL BRING MAXIMUM TEMPERATURES ON FRIDAY AND
FRIDAY NIGHT TO ABOVE NORMAL VALUES.
THE SOUTHERLY FLOW WILL SHIFT SOUTHWESTERLY AND INCREASE AS A LOW
PRESSURE SYSTEM DEVELOPS AND MOVES EASTWARD ACROSS THE NORTHERN
PLAINS...AND A COLD FRONT APPROACHES OUR AREA. CLOUD COVER WILL
INCREASE AHEAD OF THIS SYSTEM BY SATURDAY AFTERNOON. SINCE THE
FORECAST AREA WILL STILL BE IN THE WARM SECTOR OF THE SYSTEM
DURING THE DAY SATURDAY...TEMPERATURES WILL BE WELL ABOVE NORMAL.
THE COLD FRONT WILL BRING WITH IT AMPLE MOISTURE AND GOOD
CHANCES FOR PRECIPITATION BY SATURDAY EVENING TO THE OHIO VALLEY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
ENTIRE AREA SHOULD SEE SHOWERS SATURDAY NIGHT AND SUNDAY AS THE
FRONT PUSHES THROUGH. KEPT THUNDER OUT OF THE FORECAST AS IT
APPEARS THAT INSTABILITY WILL BE LACKING.
AFTER THE FRONT MOVES EAST ON SUNDAY...AN UPPER TROUGH WILL KEEP A
LOW CHANCE OF SHOWERS INTO MONDAY...MAINLY IN EASTERN COUNTIES.
ANOTHER UPPER DISTURBANCE PASSING THROUGH THE GREAT LAKES MAY BRING
A FEW SHOWERS TO NORTHERN LOCATIONS ON TUESDAY. EXPECT MAINLY DRY
WEATHER ON WEDNESDAY WITH HIGH PRESSURE PUSHING IN FROM THE
SOUTHWEST.
TEMPERATURES WILL START OUT ABOVE NORMAL ON SATURDAY AHEAD OF THE
COLD FRONT...WITH HIGHS FORECAST TO BE AROUND 60. HIGHS WILL BE NEAR
NORMAL IN THE 40S SUNDAY THROUGH TUESDAY. COLDER READINGS AROUND 40
MAY BE IN STORE FOR WEDNESDAY.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
A RIDGE OF HIGH PRESSURE STRETCHED FROM CENTRAL PENNSYLVANIA
SOUTHWEST INTO THE DEEP SOUTH THIS AFTERNOON. THE HIGH WILL MOVE
SLOWLY SOUTHEAST THROUGH THE TAF PERIOD.
CIGS AND VSBYS CONTINUE TO BE A CONCERN. VISIBLE SATELLITE IMAGERY
DEPICTED AN EXPANSIVE AREA OF LOW CLOUDS FROM EASTERN TEXAS
NORTHEAST INTO THE GREAT LAKES. EROSION OF THE LOW CLOUDS...DUE TO
DAYTIME HEATING AT THE STRATUS/CLEAR SKY INTERFACE...WAS
OCCURRING OVER NE OHIO AND ACROSS SE OHIO...EASTERN KENTUCKY AND
WESTERN WEST VIRGINIA. MODELS ARE NOT CAPTURING THIS MOISTURE VERY
WELL AND HENCE FORECASTS OF SKIES GOING CLEAR OR GOING BACK TO
CLOUDY ARE NOT OF THE HIGHEST CONFIDENCE. EROSION OF THE LOW
CLOUDS WILL LIKELY CREEP TOWARD THE KCVG/KLUK TAFS AND THE
KCMH/KLCK TAFS...BUT WHETHER THEY MAKE IT BEFORE THE SUN SETS
REMAINS TO BE SEEN. ATTM...HAVE DECIDED TO KEEP CIGS IN FOR ALL
TAF SITES AND TO BRIEFLY ALLOW THEM TO RISE TO MVFR CIGS AND VFR
VSBYS. FOR TONIGHT...RUC MODEL INDICATES THAT WHERE CLOUDS HAVE
ERODED...LOW LEVEL STRATUS MAY FORM AGAIN. HAVE ALLOWED CIGS TO
DROP INTO THE LIFR CATEGORY WITH VSBYS IN THE MVFR CATEGORY. SOME
MODELS INDICATE THAT RELATIVELY DRIER AIR MAY TRY TO CREEP NORTH
OVERNIGHT. WHETHER THIS MATERIALIZES INTO CLEAR SKIES IS VERY
UNCERTAIN AT THIS POINT. CURRENT THINKING IS THAT ON FRIDAY WITH
AN INCREASING LOW LEVEL FLOW AND DAYTIME HEATING...ANY RESIDUAL LOW
CLOUDS WILL FINALLY ERODE AWAY COMPLETELY...ALLOWING TAF SITES TO
RETURN TO VFR CONDITIONS.
OUTLOOK...MVFR/IFR CIGS/VSBYS POSSIBLE SATURDAY NIGHT INTO MONDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN/LATTO
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN/LATTO
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1146 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE RIDGE WILL KEEP LOW CLOUDS AND COOL AIR LOCKED IN
PLACE OVER MUCH OF THE REGION TODAY AND TONIGHT. THE RIDGE WILL
SLIDE EASTWARD AND BRING SOUTHERLY FLOW AND A WARMING TREND FOR
FRIDAY AND SATURDAY. BY SATURDAY NIGHT...AN APPROACHING COLD FRONT
WILL INCREASE CLOUD COVER AND CHANCES FOR PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
IT WILL BE A DIFFICULT CLOUD AND TEMPERATURE FORECAST FOR THIS
AFTERNOON.
VISIBLE SATELLITE IMAGERY CONTINUED TO SHOW AN EXPANSIVE AREA OF
STRATUS ACRS THE FORECAST AREA. THE EXCEPTION WAS OVER NE OHIO AND
TO OUR SOUTHEAST OVER EASTERN KENTUCKY AND WESTERN WEST VIRGINIA
WHERE STRATUS WAS ERODING AWAY AT THE STRATUS/CLEAR SKY INTERFACE.
THE RUC MODEL HAS BEEN HANDLING THE LOW LEVEL MOISTURE THE BEST.
HOWEVER...NO MODEL IS GOING TO CAPTURE THE AMOUNT OF ERODING THAT
MAY OCCUR TO OUR EAST/SOUTHEAST THIS AFTERNOON. BASED ON EROSION
TRENDS...HAVE ALLOWED SKIES TO BECOME PARTLY CLOUDY/MOSTLY SUNNY
IN OUR SOUTHEASTERN/SOUTHERN AREAS. WE SHOULD KNOW BY 3 TO 4 PM
HOW FAR EROSION TAKES PLACE AND HOW THIS WILL AFFECT TONIGHTS SKY
CONDITION AND OVERNIGHT LOWS. HAVE RAISED TEMPS SLIGHTLY SE/S TO
AROUND 50 WITH MORE INSOLATION POSSIBLE. OTHERWISE...THE MAJORITY
OF THE REGION WILL HAVE HIGHS IN THE MID 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
HIGH PRESSURE WILL GRADUALLY SHIFT EASTWARD TOWARD THE MID
ATLANTIC TONIGHT. BIGGEST DILEMMA OVERNIGHT WILL BE SKY CONDITION
AND OVERNIGHT LOWS. NAM-WRF AND GFS HAVE NOT HANDLED THE CURRENT
LOW LEVEL STRATUS AND THUS DO NOT HAVE FULL CONFIDENCE IN ITS
RH/MODEL SOUNDING SOLUTIONS WHERE INDICATE A CLEARING TREND FROM
SOUTH TO NORTH OVERNIGHT. THAT BEING SAID...CURRENT THINKING IS
THAT WHERE CLOUDS STAY SOCKED IN THROUGH THE DAY...THEY WILL
LIKELY REMAIN SO OVERNIGHT. HOWEVER...IT IS STILL POSSIBLE THAT
SOME DRIER AIR MAY PUSH NORTHWARD IN THE BOUNDARY LAYER. THUS...IT
IS A VERY DIFFICULT FORECAST TO PINPOINT CLOUDY TO CLEAR AND
WHETHER AREAS THAT CLEAR MAY SEE VERY LOW STRATUS FORM AGAIN.
ATTM...HAVE KEPT WEST CENTRAL OHIO...THE WHITEWATER/MIAMI VALLEYS
AND MUCH OF CENTRAL OHIO CLOUDY WHILE LEAVING SRN/SERN LOCATIONS
IN THE PARTLY CLOUDY/MOSTLY CLEAR REGIME. OVERNIGHT LOWS WILL BE
CLOUD DEPENDENT...THUS THEY SHOULD BE WARMEST ACRS THE NW WHERE
CLOUDS/WINDS WILL KEEP TEMPS FROM FALLING TOO MUCH.
FRIDAY THROUGH FRIDAY NIGHT...SOUTHERLY FLOW WILL BRING WARMER
TEMPERATURES ACROSS OUR AREA. CLOUDS ON FRIDAY SHOULD ERODE
AWAY..LEAVING MOSTLY SUNNY SKIES BY FRIDAY AFTERNOON. SUNSHINE AND
SOUTHERLY FLOW THIS WILL BRING MAXIMUM TEMPERATURES ON FRIDAY AND
FRIDAY NIGHT TO ABOVE NORMAL VALUES.
THE SOUTHERLY FLOW WILL SHIFT SOUTHWESTERLY AND INCREASE AS A LOW
PRESSURE SYSTEM DEVELOPS AND MOVES EASTWARD ACROSS THE NORTHERN
PLAINS...AND A COLD FRONT APPROACHES OUR AREA. CLOUD COVER WILL
INCREASE AHEAD OF THIS SYSTEM BY SATURDAY AFTERNOON. SINCE THE
FORECAST AREA WILL STILL BE IN THE WARM SECTOR OF THE SYSTEM
DURING THE DAY SATURDAY...TEMPERATURES WILL BE WELL ABOVE NORMAL.
THE COLD FRONT WILL BRING WITH IT AMPLE MOISTURE AND GOOD
CHANCES FOR PRECIPITATION BY SATURDAY EVENING TO THE OHIO VALLEY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ENTIRE AREA SHOULD SEE SHOWERS SATURDAY NIGHT AND SUNDAY AS THE
FRONT PUSHES THROUGH. KEPT THUNDER OUT OF THE FORECAST AS IT
APPEARS THAT INSTABILITY WILL BE LACKING.
AFTER THE FRONT MOVES EAST ON SUNDAY...AN UPPER TROUGH WILL KEEP A
LOW CHANCE OF SHOWERS INTO MONDAY...MAINLY IN EASTERN COUNTIES.
ANOTHER UPPER DISTURBANCE PASSING THROUGH THE GREAT LAKES MAY BRING
A FEW SHOWERS TO NORTHERN LOCATIONS ON TUESDAY. EXPECT MAINLY DRY
WEATHER ON WEDNESDAY WITH HIGH PRESSURE PUSHING IN FROM THE
SOUTHWEST.
TEMPERATURES WILL START OUT ABOVE NORMAL ON SATURDAY AHEAD OF THE
COLD FRONT...WITH HIGHS FORECAST TO BE AROUND 60. HIGHS WILL BE NEAR
NORMAL IN THE 40S SUNDAY THROUGH TUESDAY. COLDER READINGS AROUND 40
MAY BE IN STORE FOR WEDNESDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
HIGH PRESSURE IS CENTERED OVER THE MID OHIO VALLEY THIS MORNING
WITH A SOLID IFR STRATUS DECK IN PLACE BELOW IT. THIS STRATUS HUNG
IN THROUGH THE DAY BACK TO OUR WEST ON WEDNESDAY...SO WOULD NOT
BE SURPRISED IF IT HOLDS ON THROUGH MUCH OF THE DAY TODAY. CIGS
MAY BRIEFLY GO TO LOW MVFR. HOWEVER...WITH MOISTURE IN PLACE
OVERNIGHT...THEY MAY VERY WELL DROP TO LIFR OR LOWER. HAVE SLOWED
DOWN ANY ONSET OF CLEARING FOR TODAY AND TONIGHT.
OUTLOOK...MVFR CIGS/VSBYS POSSIBLE SUNDAY AND MONDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN/LATTO
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN/LATTO
LONG TERM...CONIGLIO
AVIATION...HICKMAN/JGL
AREA FORECAST DISCUSSION
NWS NORMAN OK
1118 AM CST THU NOV 24 2011
.AVIATION...
18Z TAFS... VFR CONDITIONS THROUGHOUT THE TAF PERIOD. SOME
LIMITED VISIBILITIES OF MVFR MAY OCCUR EARLY FRIDAY MORNING AT A
FEW SITES BUT TOO UNCERTAIN FOR MENTION IN TAF AT THIS TIME.
OTHERWISE... GUSTY WINDS WILL AFFECT THE AREA.
&&
.PREV DISCUSSION... /ISSUED 545 AM CST THU NOV 24 2011/
AVIATION...
RECENT SATELLITE TREND SHOWS LOW CLOUDS AND DENSE FOG EXPANDING
MORE NORTHWARD WITH A SLOWER PROGRESSION TO THE WEST. THEREFORE...
WILL NOT MENTION IFR CEILINGS AT TAF SITES. COULD SEE SOME LIGHT
FOG ACROSS NORTH CENTRAL OKLAHOMA DURING THE NEXT FEW HOURS SO
WILL MENTION FOG IN PNC TAF. OTHERWISE VFR CONDITIONS EXPECTED AT
TAF SITES THROUGH AT LEAST 6Z FRIDAY.
PREV DISCUSSION... /ISSUED 219 AM CST THU NOV 24 2011/
DISCUSSION...
CLOUD COVER...WITH CEILINGS AROUND 200 FT AND DENSE FOG...CONTINUES
TO SPREAD NORTH AND WEST THIS MORNING AROUND 15-20KT. THIS BRINGS
AREA OF LOW CLOUDS TO I-35 AROUND 11Z. HRRR WHICH IS USUALLY TOO
AGGRESSIVE...HAS LOW CEILINGS TO HWY 81 AND SOUTH OF I-40 BY 13Z.
WILL ADJUST SKY GRIDS TO REFLECT CLOUDS NEAR HWY 81 AND NORTH INTO
LINCOLN/PAYNE COUNTIES. HEATING AND INCREASING WINDS SHOULD ERODE
CLOUDS BY MID MORNING...ESPECIALLY WESTERN EDGE.
WINDS TONIGHT AND A MILD THANKSGIVING SHOULD KEEP THE FOG PONTENTIAL
LOW BUT SOME LOW CLOUDS MAY DEVELOP/MOVE INTO SOUTHERN PARTS OF
THE FA BY EARLY FRIDAY. ONLY MINOR ADJUSTMENTS WERE MADE TO
TIMING OF WX/POPS WITH FRIDAY/EARLY SATURDAY TROUGH. OVERNIGHT
LOWS FRIDAY NIGHT WILL BE A LITTLE TRICKY WITH PLACEMENT OF COLD
FRONT/CAA.
MOST OF THE RAIN SHOULD END BY MID MORNING SATURDAY. STRONG...GUSTY
NORTH WINDS SATURDAY SHOULD BE THE MAIN WEATHER STORY. RATHER DRY
AIRMASS BEHIND EARLY SATURDAY COLD FRONT WILL RESULT IN COLD
OVERNIGHT LOWS SUNDAY AND MONDAY. WITH SURFACE HIGH BUILDING SOUTH
INTO TEXAS...PER GFS...AFTERNOON TEMPERATURES USUALLY REBOUND QUICKER
THAN EXPECTED. ANOTHER COLD FRONT WILL PUSH ACROSS THE SOUTHERN
PLAINS LATE MONDAY INTO TUESDAY..BUT NO PRECIPITATION IS EXPECTED
WITH THE FRONTAL PASSAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 68 47 64 45 / 0 0 20 70
HOBART OK 67 48 64 40 / 0 0 40 50
WICHITA FALLS TX 68 48 65 46 / 0 0 40 70
GAGE OK 71 47 65 36 / 0 0 40 40
PONCA CITY OK 68 47 65 43 / 0 0 20 70
DURANT OK 68 48 65 51 / 0 0 30 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
22/25/25
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1146 AM CST THU NOV 24 2011
.SHORT TERM...TODAY THROUGH SATURDAY
352 AM CST THU NOV 24 2011
AT 3 AM...VLIFR/IFR CEILINGS WERE SEEN ACROSS ACROSS THE FORECAST
AREA. THESE CLOUDS HAVE BEEN SPREADING IN ALL DIRECTIONS
UNDERNEATH THE STRONG INVERSION LOCATED JUST ABOVE THE SURFACE.
OVERALL...THE HRRR HAS BEEN HANDLING THESE CLOUDS THE BEST...AND
IT SUGGESTS THAT THERE WILL BE GRADUAL DISSIPATION OF THESE CLOUDS
ON THE OUTER EDGES BETWEEN 16Z AND 18Z...AND THEN THIS PROGRESS A
BIT FASTER ACROSS THE REMAINING AREAS AS SOME DRIER AIR FROM ALOFT
MIXES DOWN.
DESPITE THE PERSISTENT CLOUDS THIS MORNING...THE COMBINATION OF
SOUTHERLY WINDS AND AFTERNOON SUNSHINE WILL HELP THE TEMPERATURES
CLIMB INTO THE 50S ACROSS THE FORECAST AREA. DUE TO THE SUNSHINE
ARRIVE EARLIER...THE WARMEST TEMPERATURES /UPPER 50S/ WILL LIKELY
FOUND IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA THIS AFTERNOON. WITH
NORTH CENTRAL WISCONSIN BEING ONE OF LAST TO LOSE THE CLOUDS...SO
THEY WILL LIKELY ONLY SEE TEMPERATURES CLIMBING TO AROUND 50 DEGREES.
FOR TONIGHT...BOTH THE 24.00Z NAM AND GFS SOUNDINGS SUGGEST THAT
THE CLOUDS ACROSS NORTHERN AND EASTERN WISCONSIN WILL ONCE AGAIN
SPREAD WESTWARD ACROSS THE FORECAST AREA. THE COMBINATION OF THESE
CLOUDS AND UNUSUALLY MOIST DEW POINTS WILL RESULT IN MINIMUM
TEMPERATURES ONLY FALLING INTO THE LOWER AND MID 40S. THIS IS
ABOUT 5 DEGREES WARMER THAN OUR NORMAL HIGH TEMPERATURE FOR THIS
DATE.
ON FRIDAY...THE LOW CLOUDS WILL GRADUALLY LIFT AND DISSIPATE
DURING THE DAY. HOWEVER AT THE SAME TIME...MID AND HIGH CLOUDS
WILL BE STREAMING INTO THE REGION AHEAD OF AN APPROACHING LONG
WAVE TROUGH. AS RESULT...NOT EXPECTING TOO MUCH SUNSHINE. DESPITE
THE LACK OF ABUNDANT SUNSHINE...SOUTHERLY WINDS WILL HELP WARM
TEMPERATURES INTO THE LOWER AND MID 50S.
ON FRIDAY NIGHT...THE MODELS CONTINUE TO INDICATE THAT MODERATE TO
STRONG MOISTURE TRANSPORT WILL MOVE INTO THE FORECAST AREA. THIS
WILL BE THE BEST ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA
DURING THE EVENING. DURING THE OVERNIGHT...MODERATE TO STRONG
ISENTROPIC LIFT AND FRONTOGENESIS WILL MOVE EAST INTO THE AREA.
AT THIS TIME...IT LOOKS LIKE THE BEST RAIN CHANCES WILL BE FROM
ALONG THE MISSISSIPPI RIVER EAST. DESPITE THE RAIN...THE SOUTHERLY
WINDS SHOULD HELP KEEP THE MINIMUM TEMPERATURES UNUSUALLY WARM FOR
THIS TIME OF YEAR. THEY WILL BE IN THE LOWER AND MID 40S ACROSS
SOUTHEAST MINNESOTA AND NORTHEAST IOWA...AND IN THE MID TO UPPER
40S FOR WESTERN WISCONSIN.
ON SATURDAY AND SATURDAY NIGHT...BOTH THE GFS AND ECMWF SHOW THAT
THERE WILL BE RAPID CYCLOGENESIS OCCURRING ACROSS MINNESOTA. THIS
IS IN RESPONSE TO SOME INTERACTION BETWEEN THE NORTHERN AND
SOUTHERN SHORT WAVE TROUGH EMBEDDED IN THE LONG WAVE TROUGH. THIS
RESULT IN THE TROPOPAUSE DESCENDING TO AROUND 500 MB...AND A RAPID
TIGHTENING OF THE SURFACE PRESSURE GRADIENT. SUSTAINED WINDS WILL
CLIMB INTO THE 15 TO 30 MPH RANGE...AND THE WIND GUSTS WILL RANGE
FROM 30 TO 40 MPH.
WITH STRONG COLD AIR ADVECTION BEING FOUND IN THE WAKE OF THE
COLD FRONT ON SATURDAY...TEMPERATURES SHOULD FALL STEADILY THROUGH
THE EARLY AFTERNOON AND THEN STABILIZE. THIS TREND WAS INTRODUCED
TO THE HOURLY TEMPERATURE GRIDS. IN ADDITION...GFS SOUNDINGS ARE
COLD ENOUGH FOR A SOME SNOW TO MIX IN. THIS WAS ALREADY IN THE
SOUTHEAST MINNESOTA AND NORTHEAST FORECAST GRIDS...BUT IT NOW
LOOKS LIKE WESTERN WISCONSIN MAY ALSO SEE SOME OF THIS SNOW
TOO...SO IT WAS ADDED TO THE GRIDS DURING THE MID AND LATE
AFTERNOON.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
352 AM CST THU NOV 24 2011
ON SATURDAY NIGHT...IT CONTINUE TO LOOK LIKE THERE WILL BE SOME
LINGERING LIGHT PRECIPITATION. AS RESULT...KEPT A CHANCE OF LIGHT
RAIN AND SNOW DURING THE EVENING...AND LIGHT SNOW OVERNIGHT. LIKE
THE PAST COUPLE OF DAYS...NOT EXPECTING TOO MUCH SNOW AT ALL FROM
THIS SYSTEM. IN ADDITION TO THE MIXED PRECIPITATION...THE STRONG
WINDS WILL LIKELY CONTINUE THROUGH THE NIGHT. SUSTAINED WINDS WILL
REMAIN IN THE 15 TO 30 MPH RANGE...AND THE WINDS WILL GUST UP TO
40 MPH.
BEYOND THIS TIME PERIOD...THERE CONTINUES TO BE VERY LITTLE
CONSISTENCY. HOWEVER WITH THIS SAID...I DO LIKE THAT THE MODELS
ARE STARTING TO BECOME MORE TRANSITORY WITH THEIR SYSTEM. THIS
MAKES SENSE WHEN LOOKING AT THE RATHER ACTIVE WAVE PATTERN FROM
AFRICA INTO THE WESTERN PACIFIC. THE GFS PATTERN ACTUALLY
RESEMBLES ONE OF THE PATTERNS THAT YOU WOULD TYPICALLY SEE DURING
A LA NINA. ANOTHER FEATURE THAT WE WILL HAVE TO PAY ATTENTION TO
AS WE HEAD INTO DECEMBER IS THE INTENSIFYING MADDEN JULIAN
OSCILLATION /WHICH HAS BEEN CONSISTENTLY FORECAST BY THE
BRAZILLIAN...ECMWF...JAPANESE...AND U.S. MODEL ENSEMBLES FOR THE
PAST WEEK/ THAT IS LOCATED OVER THE WESTERN INDIAN OCEAN. THIS WILL
LIKELY CAUSE SOME ISSUES WITH THE MODEL RUN TO RUN CONSISTENCY AT
LEAST INITIALLY. IN ADDITION...IT MAY BE ONE OF THE REASONS WHY THE
CLIMATE FORECAST SYSTEM VERSION 2 MODEL IS SUGGESTING THAT AT
LEAST THE FIRST HALF OF DECEMBER MAY END UP BEING WARMER THAN
NORMAL.
&&
.AVIATION...THROUGH 18Z FRIDAY
1146 AM CST THU NOV 24 2011
STRATUS THAT WAS OVER THE TAF SITES HAS MIXED OUT THIS MORNING ON
SCHEDULE...THOUGH SOME MVFR BR STILL PERSISTS. THIS MVFR BR SHOULD
GO VFR BY 19Z WITH CONTINUED MIXING. QUESTION THEN BECOMES IF
STRATUS CAN REDEVELOP TONIGHT AS MOISTURE SURGES UP FROM THE
CENTRAL PLAINS ON BREEZY SOUTHWEST WINDS. THERE IS A LOT OF
UNCERTAINTY ON THIS...SINCE IT DEPENDS ON HOW WARM IT ENDS UP
THIS AFTERNOON AND HOW MUCH COOLING CAN TAKE PLACE TONIGHT GIVEN
THE AMOUNT OF WIND. RIGHT NOW HAVE KEPT THE IDEA OF A SCATTERED
IFR/MVFR DECK AFTER 09Z IN CASE CLOUDS DEVELOP. MORE CONFIDENCE
EXISTS THAT THE MOISTURE MAY END UP RESULTING IN MVFR BR AND HAVE
THIS IN THE FORECAST FROM 09-15Z.
ANOTHER ISSUE WITH THE AVIATION FORECAST IS WINDS. MIXING TODAY IS
ALLOWING FROM SOUTHERLY GUSTS OF 20-30KT...HIGHEST IN KRST. THIS
SHOULD CONTINUE AT KRST THROUGH THE EARLY MORNING HOURS WITH A
TIGHT PRESSURE GRADIENT IN PLACE AHEAD OF TROUGHING OVER THE
DAKOTAS. HOWEVER...AT KLSE...LOW LEVEL WIND SHEAR IS LIKELY TO
DEVELOP AFTER 23Z WITH COOLING AND BEING IN THE VALLEY. SHOULD
GUSTS STOP AT KRST...LOW LEVEL WIND SHEAR WILL BE NEEDED THERE AS
WELL. KEPT THE LOW LEVEL WIND SHEAR GOING AT KLSE UNTIL 15Z WHEN
AT THAT POINT MIXING CAN START PRODUCING GUSTS AGAIN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
251 AM CST THU NOV 24 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...AJ