Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 11/22/11
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
927 PM MST SAT NOV 19 2011
.UPDATE...
MOISTURE OVERRUNNING A STALLED COLD FRONT DRAPED OVER EAST-CENTRAL
UTAH AND WEST CENTRAL COLORADO...ALSO INFLUENCED BY CHANNELED MID-
LEVEL VORTICITY WILL CONTINUE TO BRING SNOW TO THE NORTHERN
MOUNTAINS AND ROAN PLATEAU OVERNIGHT. MODEL GUIDANCE INDICATED AN
ADDITIONAL 3 TO 5 INCHES OVER THE AREA SO WILL EXTEND HILITES THROUGH
12Z SUNDAY. SUSPECT COLD AIR PACKED INTO THE STEAMBOAT BASIN WILL
CONTINUE TO BRING SNOWFALL TO THE TOWN WITH AN ADDITIONAL 1 TO 3
INCHES LIKELY OVERNIGHT AND DECIDED TO KEEP WARNING GOING THERE AS
WELL. SNOWFALL TO BE MORE SPORADIC OVER THE CENTRAL YAMPA RIVER BASIN
SO HAVE LET THE WARNING FOR ZONE 2 EXPIRE. FULL MODEL SUITE HAS NOT
UPDATED AND NAM12 AND RUC13 DISAGREE WITH RESPECT TO QPF...SO
HESITANT TO ADJUST ADVISORY FOR THE CENTRAL MOUNTAINS.
UPDATED AVIATION DISCUSSION FOR THE 06Z TAF ISSUANCE. SEE BELOW.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
HEALTHY SNOW AMOUNTS EXISTS NORTH OF THE SURFACE FRONT WHERE MOIST
SYMMETRIC INSTABILITY IN ADDITION TO THE OROGRAPHICS HAVE PLAYED A
SIGNIFICANT ROLE TODAY. SNOWFALL HAS EXCEEDED EXPECTATIONS ACROSS
MUCH OF NORTHWEST COLORADO TODAY. APPEARS THE SURFACE FRONT IS
LOCATED ON A LINE FROM CANYONLANDS NATIONAL PARK TO CRESTED BUTTE.
SATELLITE IMAGES SHOW A GRADUAL WARMING OF THE CLOUD TOPS...SO THE
CURRENT TREND IS FOR SNOW RATES TO DIMINISH DURING THE NEXT SEVERAL
HOURS. GRADIENT FLOW IS WEAKENING AND ALSO BACKING AROUND TO A
SOUTHWEST FLOW...THIS WILL SHELTER SPOTS THAT HAVE RECEIVED HEAVY
SNOWFALL TODAY. THIS PROCESS IS GRADUAL AND WIDESPREAD SNOW MAY NOT
END UNTIL MID TO LATE EVENING. SO HAVE EXTENDED AND UPGRADED WINTER
WEATHER HIGHLIGHTS EARLIER THIS AFTERNOON. REMOTE SENSORS ON THE
PARK RANGE AND FLAT TOP MOUNTAINS INDICATE 12+ INCHES OF SNOW THUS
FAR WITH SNOW WATER EQUIVALENT RATIOS NEARLY 15-20 TO 1.
THE STEADY STREAM OF PACIFIC MOISTURE ABATES...BUT NEVER STOPS AS WE
GO INTO SUNDAY. DYNAMICAL FORCING IS MINIMAL DURING THE PERIOD BUT
REMNANTS OF THE SURFACE FRONT WILL PROVIDE SOME LOW LEVEL FORCING.
THE NORTHERN MOUNTAINS WILL BE THE TARGET AGAIN WITH SOUTHWEST FACING
ASPECTS THE PREFERRED SPOTS FOR PRECIPITATION. PROGGED QPF AMOUNTS
IS LOW AND ANY MOUNTAIN SNOW ACCUMULATIONS WILL BE LIGHT AND
GENERALLY 3 INCHES OR LESS.
MOIST LAYER DEEPENS SUNDAY NIGHT AND MONDAY AS THE TROUGH AXIS
MOVES ACROSS THE DESERT SOUTHWEST. THIS WILL ENHANCE MOUNTAIN SNOW
AMOUNTS AND POSSIBLY ADDITIONAL WINTER WEATHER HIGHLIGHTS WILL BE
REQUIRED. GRADIENT FLOW IS WEAK AND THE BEST DYNAMICAL FORCING
STAYS SOUTH OF THE BORDER...BUT ISENTROPIC ANALYSIS DOES INDICATE
SOME MID LEVEL COOLING WILL OCCUR AND THIS WILL HELP TRIGGER
ADDITIONAL SNOWFALL.
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MONDAY NIGHT-WEDNESDAY: THE UPPER TROUGH PASSES THROUGH NEW MEXICO
MONDAY NIGHT. MTN TOP WINDS VEER NW THROUGH THE EVENING. MOISTURE IS
INITIALLY DEEP ENOUGH TO CONTINUE TO PRODUCE THE LAST LIGHT
ACCUMULATIONS IN THE CO MTNS. COLDER TEMPERATURES EXPECTED MONDAY
NIGHT...THOUGH LINGERING CLOUDS IN CENTRAL COLORADO MAY MODIFY
THESE MIN TEMPS. A RIDGE AMPLIFIES OVER THE AREA ON TUESDAY FOR
THE BEGINNING OF A WARMING TREND IN THE MTNS BUT CAPPING THE
VALLEYS. THE RIDGE SHIFTS EAST TUESDAY NIGHT AND SW FLOW ALOFT ON
WEDNESDAY CONTINUES THE WARMING TREND ON THE SLOPES WITH VALLEYS
SHOWING LESS OF A WARMING TREND.
THURSDAY-FRIDAY: CLOUDS AND SW GRADIENT WINDS INCREASE ON
THANKSGIVING. VALLEY INVERSIONS MAY MIX OUT THURSDAY AFTERNOON FOR
THE MILDEST DAY OF THE WEEK. THE 12Z GFS/EC BOTH SHOW SHOWERS
STARTING ON SW-FACING SLOPES THURSDAY NIGHT AND BECOMING MORE
WIDESPREAD ON FRIDAY. COORDINATED WITH RIW CYS AND PUB TO INCREASE
POPS FOR THESE PERIODS. TROUGH PASSAGE IN THE AFTERNOON VEERS THE
FLOW TO NW WITH SHOWERS CURRENTLY TIMED TO LAST INTO THE EVENING.
SATURDAY: IN A CONTINUED HIGHLY AMPLIFIED PROGRESSIVE FLOW...HIGH
PRESSURE BUILDS IN FOR SATURDAY WITH ANOTHER TROUGH PASSAGE TIMED
FOR EARLY IN THE NEW WEEK.
&&
.AVIATION /FOR 06Z TAF ISSUANCE/
THE COLD FRONT REMAINED STATIONARY...STRETCHING FROM WEST TO EAST
JUST SOUTH OF THE I-70 CORRIDOR THIS EVENING. THE FRONT IS EXPECTED
TO REMAIN QUASI-STATIONARY UNTIL IT LIFTS NORTHWARD ON SUNDAY. SOUTH
OF THE FRONT GUSTY SOUTHWEST WINDS WILL BRING MOUNTAIN TURBULENCE AND
SCATTERED MOUNTAIN SNOW SHOWERS. ALONG AND NORTH OF THE FRONT...
CEILINGS WILL REMAIN LOW IN WIDESPREAD SNOWFALL TONIGHT. AREAS OF
MVFR...AND ISOLATED IFR CONDITIONS...ARE EXPECTED OVER THE HIGHER
ELEVATION AIRPORTS THROUGH TONIGHT. KCAG...KHDN....KSBS...KEGE...AND
KASE TERMINAL SITES WILL SEE LOWERED CEILINGS AND LOWERED VSBYS AT
TIMES IN SNOW SHOWERS. KRIL WILL HAVE DECREASING SHOWERS AND
INCREASING CIGS AND VSBY AFTER MIDNIGHT. MOUNTAIN TOPS WILL REMAIN
MOSTLY OBSCURED OVERNIGHT. SCATTERED SNOW SHOWERS WITH MVFR-LOCAL IFR
CEILINGS AND VSBYS WILL CONTINUE INTO SUNDAY. SNOW SHOWERS WILL
LARGELY DIMINISH SUNDAY EVENING...THOUGH A FEW LINGERING FLURRIES
MAY CONTINUE OVER MOUNTAIN PEAKS AND HIGH RIDGES.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR ZONES
009-010-012.
WINTER STORM WARNING UNTIL 6 AM MST SUNDAY FOR ZONES
004-005-013.
WINTER WEATHER ADVISORY UNTIL 6 AM MST SUNDAY FOR ZONE 003.
UT...NONE.
&&
$$
UPDATE.......NL
SHORT TERM...PF
LONG TERM....JOE
AVIATION.....JOE/NL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1250 AM EST SUN NOV 20 2011
.SYNOPSIS...
HIGH PRESSURE CONTINUES TO DOMINATE THE WEATHER TONIGHT A COLD
FRONT WILL MOVE THROUGH TOMORROW NIGHT AND THEN STALL...FOLLOWED
BY MORE SEASONABLY CHILLY WEATHER NEXT WEEK. LOW PRESSURE MOVING
ALONG THIS STALLED FRONT SHOULD BRING RAIN...AND POSSIBLY SOME WET
SNOW TUESDAY NIGHT INTO WEDNESDAY. DRIER WEATHER IS EXPECTED TO
RETURN DURING THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1 AM UPDATE...
LIGHT SHOWERY BAND OF PRECIP MOVING THRU THE WRN FCST RGN PER
RADAR RETURNS...YET SUFFICIENT DRY AIR BELOW H6 IS MAKING IT
DIFFICULT FOR ANY PRECIP TO REACH THE SFC. WILL CONTINUE SLGT CHC
POPS FOR HIGHER TERRAIN ABOVE 500 FT AGL INTO 9Z.
TEMP TRENDS HAVE BEEN THE BIGGEST CHALLENGE. LATEST OBS HAVE SHOWN
A WARMING TREND PARTICULARLY ACROSS S/SE NEW ENGLAND. NEED TO
MODIFY MINS ACCORDINGLY WHICH ARE FAR TOO LOW. MID-LVL CLOUDS
STILL THICK ACROSS THE RGN WITH BLUSTERY SW FLOW. SEEMS A SAFE BET
WE ARE NOT GOING TO COOL DOWN APPRECIABLY INTO MORNING.
PREV DISCUSSION...
SHOWERY BAND OF PRECIP PROGRESSING EWD COINCIDENT WITH LIFT
ALONG THE 305K ISENTROPIC SFC PER RUC MESOANALYSIS /ROUGHLY AROUND
H6/. MOIST LAYER AT H6 PER ALY 00Z UPR AIR SOUNDING...BUT NOTE THE
ENCOMPASSING DRY AIR BELOW TO THE SFC. AMAZINGLY SEVERAL LOCALES
ACROSS MID-UPSTATE NY HAVE REPORTED TRACE PRECIP WITH CEILINGS OF
8-10 KFT...WHICH DOES ILLUSTRATE THE DIFFICULTY OF PRECIP REACHING
THE SFC.
WINDS REMAIN BLUSTERY OUT OF THE SW WITH GUSTS AROUND 30 MPH.
INFREQUENT GUSTS AROUND 15 TO 20 MPH FOR THE INTERIOR DUE TO
BOUNDARY LAYER DECOUPLING...NOT THE CASE FOR ELEVATIONS AOA 1000
FT AGL OR GREATER. WORCESTER AIRPORT REPORTING GUSTS OF AROUND 25 MPH.
VWP/S CONTINUE TO HIGHLIGHT H925 WINDS OF AROUND 50 MPH. MID-HIGH
LVL CLOUDS CONTINUE TO STREAM THRU THE RGN.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
SUNDAY...
LOW PRESSURE CENTER TRACKS THROUGH SOUTHEAST CANADA...WHILE TRAILING
COLD FRONT APPROACHES SOUTHERN NEW ENGLAND. SHOULD BE REACHING THE
WESTERN EDGE OF OUR COUNTY WARNING AREA BY 00Z MON. NOT MUCH
MOISTURE AVAILABLE WITH THE APPROACH OF THIS FRONT. EXPECTING SOME
INCREASE IN CLOUDS BUT POPS ARE DRY TO SLIGHT CHANCE. DO EXPECT
MIXING WITH PARTLY CLOUDY CONDITIONS...H925 WINDS START OUT AT 45 TO
50 KTS AT 12Z BUT DO DIMINISH OVER THE COURSE OF THE DAY. RESULT
SHOULD BE GUSTS OF 20 TO 30 MPH LATE MORNING AND ON ACROSS MUCH OF
THE INTERIOR...GUSTS 30 TO 40 MPH POSSIBLE ON THE CAPE AND ISLANDS.
MAX TEMPS IN THE UPPER 50S TO MID 60S.
SUNDAY NIGHT AND MONDAY...
SFC COLD FRNT SLIDES THRU THE RGN SUNDAY NIGHT AND WINDS BACK OUT OF
THE W/NW. HOWEVER FRONT STALLS JUST TO OUR SOUTH. MOISTURE POOLS
NEAR THE FRONT WITH WEAK LIFT...BUT TO OUR NORTH WILL BE A HIGH
PRESSURE SENDING DRIER AIR OUR WAY. AS A RESULT WILL ONLY GO WITH
SLGT CHC TO LOW CHC POPS FOR THE EXTREME S FCST ZONES SUN NIGHT.
MINS TO DROP OFF WITH NWLY FLOW AND SFC CAA...WILL GO MID 30S TO LOW
40S...WITH ISOLATED LOW 30S N/W. SHOULD BEGIN TO SEE THE DEVELOPMENT
OF AN OVERRUNNING SCENARIO ON MONDAY AS CANADIAN HIGH PRES SHUNTS
EWD. CLOUDS INCREASING THRU THE DAY. MAX TEMPS 45-50.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
OVERVIEW AND MODEL PREFERENCES...
MODELS CONTINUE TO STRUGGLE WITH FAST FLOW REGIME THROUGH THE MID
WEEK TIMEFRAME. WHILE THEIR REMAINS SOME AGREEMENT THAT A SFC
FRONT WILL STALL S OF THE AREA WITH SOME ISENTROPIC LIFT OVER SNE
THROUGH TUE. HOWEVER...IT IS THE APPROACH OF A COUPLE OF DIFFERENT
SHORTWAVES LATE TUE NIGHT INTO WED. ECMWF STILL SUPPORTS THESE
WAVES PHASING PRIOR TO REACHING THE REGION...HOWEVER THE GFS IS
STILL MORE PROGRESSIVE AND DOES NOT ALLOW THESE TWO WAVES TO
PHASE. THE ECMWF...WHICH DOES SHOW SOME SUPPORT FROM THE GEFS
MEAN...IS MUCH SLOWER AND MORE AMPLIFIED AS A RESULT OF THIS
PHASING. AS A RESULT...THE MOVEMENT/STRENGTH OF THE SFC LOW
SPAWNED BY THESE TWO WAVES IS STILL IN DISPUTE. THE GFS IS FASTER
AND FURTHER N AS IT APPROACHES...WHILE THE ECMWF IS SLOWER AN
FURTHER S. ATTM...WITH THE ECMWF HAVING MORE SUPPORT...WILL LEAN
FCST TOWARDS ITS SOLN BUT WILL MAINTAIN A FAIR LVL OF PERSISTENCE
IN THE FCST AS THERE ARE STILL SOME FACTORS TO BE RESOLVED. EVEN
WITH THESE DIFFERENCES EARLY ON...THE GUIDANCE SUITE IS IN GOOD
AGREEMENT THAT A SECOND ROUND OF STRONG RIDGING WILL BUILD OVER
THE ATLANTIC STATES WITH HIGH PRES INTO NEXT WEEKEND.
DETAILS...
MON NIGHT INTO TUE...
A STALLED BAROCLINIC ZONE WILL REMAIN S OF THE ARE THROUGH THIS
PERIOD. WHILE THERE IS STILL A BIT OF DISPUTE ON EXACTLY WHERE
THIS WILL END UP...IT WILL BE UNDER THE INFLUENCE OF STRONG HIGH
PRES TO THE N. THIS WILL BEGIN TO GRADUALLY SLIDE INTO THE
MARITIMES DURING THE PERIOD. GIVEN THE INCREASING MID LVL
WAA...AND AT LEAST SOME MOISTURE THROUGH THE PERIOD. FEEL THAT
OCCASIONAL -SHRA CANNOT BE RULED OUT AS LONG AS THE FRONT STAYS
PUT. HOWEVER...FEEL THAT MUCH OF THE TIME WILL BE MOSTLY DRY AND
SIMPLY CLOUDY...WHICH IS CONSISTENT WITH PREVIOUS SHIFTS FCST. H92
TEMPS GRADUALLY INCREASE TO +2C TO +6C DURING THE TIME PERIOD.
CLOUD COVER MAY NOT ALLOW THESE VALUES TO BE FULLY REACHED...SO
EVEN DURING PEAK HEATING TEMPS SHOULD NOT BE ABLE TO REACH 50F.
TUE NIGHT INTO WED...
AS MENTIONED EARLIER...THERE ARE STILL DISCREPANCIES TO BE WORKED
OUT FOR A ROBUST WAVE/SFC LOW SYSTEM THAT WILL AFFECT SNE DURING
THIS TIMEFRAME. IF THE SYSTEM LEANS MORE TOWARD THE GFS AS IT
STANDS NOW...THE SYSTEM WILL BE FULLY CLEAR OF THE AREA BY WED
EVENING. WHILE THE ECMWF IS SLOWER AND LINGERS INTO WED NIGHT. THE
PROGRESSIVE PATTERN FAVORED BY THE GFS ALSO ALLOWS THE LOW TO MOVE
N OF THE REGION...WITH MUCH OF THE FA IN THE WARM SECTOR. THE
ECMWF/GEFS MEAN REMAINS FURTHER S AND COOLER DUE TO MORE
AMPLIFICATION. GIVEN THAT THE ECMWF DOES HAVE SOME SUPPORT FROM
THE GEFS MEAN...WILL LIKELY LEAN GRIDS SLIGHTLY CLOSER TO THIS
SOLN...BUT NOT MAKE ANY DRASTIC CHANGES AS THERE ARE STILL SOME
ISSUES TO BE RESOLVED.
THE ECMWF IS COLDER TOO...THANKS TO THE MORE AMPLIFIED FLOW
PATTERN. AT PRECIP ONSET TUE NIGHT...FEEL THE WAA /H92 TEMPS
INCREASING CLOSE TO +3C TO +6C ON THE COOLER ECMWF/ IN ADVANCE OF
THE LOW WILL BE ENOUGH TO KEEP P-TYPE MOSTLY RAIN. HOWEVER...ON
WED...STRONGER LLVL ISALLOBARIC FLOW /WITH THE LOW PASSING TO THE
S/ WILL BEGIN TO DRAW COLDER AIR FROM THE N OVER THE REGION...SO
MAY SEE A TRANSITION TO SNOW FROM NW TO SE AS THE LOW PUSHES TO
THE E. BEST CHANCE FOR ACCUM WILL REMAIN IN THE HIGHER ELEVATIONS
OF THE E SLOPES OF THE BERKSHIRES/MONADNOCKS/WORCESTER HILLS.
GIVEN THE UNCERTAINTY HOWEVER...WILL REMAIN CONSERVATIVE WITH
OVERALL TOTALS.
THU INTO THE WEEKEND...
ANOTHER COOLING TREND AS COOL AIRMASS AND STRONG HIGH PRES BUILD
OVER THE REGION DURING THE DAY THU INTO THU NIGHT. WHILE THE
GRADUAL WARMING TREND MAY BE A BIT SLOWER THAN PREVIOUS WARMING
TRENDS THIS NOV...FEEL THAT TEMPS WILL LIKELY REBOUND TO
NORMAL...IF NOT EVEN SLIGHTLY ABOVE NORMAL BY SAT. DRY WX PREVAILS
UNDER HIGH PRES.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
INTO MORNING...
HIGH CONFIDENCE VFR. BKN-OVC 10 KFT CIGS WITH SCT-BKN 3-5 KFT CIGS
MAINLY FOR THE S/E TERMINALS. INFREQUENT 20-25 KT GUSTS THRU THE
INTERIOR...BETTER CHCS TERMINALS ON CAPE AND ISLANDS. LLWS OF 35
TO 45 KTS AT 2 KFT OUT OF THE SW AT 220...ESPECIALLY THRU THE
INTERIOR AND VLY LOCALES WHERE WINDS ARE LIGHTER.
TODAY...
HIGH CONFIDENCE VFR. SFC COLD FRNT APPROACHING TERMINALS ALONG AND
AHEAD OF WHICH SWLY FLOW WILL BE BLUSTERY WITH 25 KT GUSTS THRU
THE INTERIOR...30 KT GUSTS AND GREATER OVER THE CAPE AND ISLANDS.
BKN-OVC 5-10 KFT CIGS...THICKENING AND LOWERING THRU THE DAY WITH
APPROACHING COLD FRNT. MVFR CIGS PSBL LATE...BUT LOW CONFIDENCE.
TONIGHT...
MODERATE CONFIDENCE VFR. COLD FRNT SLIDE THRU THE TERMINALS EARLY.
WILL SEE WINDS LIGHTEN AND BACK OUT OF THE N/NW. COULD SEE SOME
STRONG 15-20 KT N/NW FLOW IN WAKE OF THE COLD FRNT. BKN-OVC 5-10
KFT CIGS WITH PSBL MVFR /MODERATE CONFIDENCE/ TO BECOME BKN-SCT
INTO MORNING. SLGT CHC OF SHRA THRU THE S TERMINALS.
MONDAY...
HIGH CONFIDENCE VFR. SOME LINGERING MVFR CIGS PSBL FOR S TERMINALS
BUT OTHERWISE HIGH PRES BUILDING INTO THE RGN ALLOWING CIGS TO
CLEAR. WILL SEE LGT N/NELY FLOW THRU THE TERMINALS...WITH AN
ONSHORE COMPONENT MORESO FOR THE E TERMINALS. ANTICIPATING MID-
HIGH CLOUDS TO FILTER THRU THE RGN LATE IN THE DAY.
MONDAY NIGHT...
HIGH CONFIDENCE VFR. HIGH PRES IN CONTROL. LGT AND VRB SFC WINDS.
MID-HIGH LVL CLOUDS CONTINUING TO FILTER THRU THE RGN.
KBOS TERMINAL...
HIGH CONFIDENCE VFR. SWLY WINDS GUSTING 25 TO 30 KTS THRU THE DAY
WILL SLACK AS A COLD FRNT IMPACTS THE TERMINAL DURING THE EARLY
MORNING HRS MONDAY. BKN-OVC CIGS 10 KFT INITIALLY...LOWERING WITH
APPROACHING COLD FRNT TO 5-7 KFT. WINDS BACKING OUT OF THE NW WITH
PASSAGE...AROUND 10-15 KTS PSBL IN THE IMMEDIATE WAKE.
OUTLOOK...MONDAY THROUGH THURSDAY...
TUESDAY...
VFR CONDITIONS DESPITE CLOUDS. LIGHTER EAST WINDS TUESDAY.
TUESDAY NIGHT-WEDNESDAY...
CONDITIONS GRADUALLY LOWERING WITH VFR LIKELY DIPPING ALL THE WAY
TO IFR BY LATE NIGHT. PERIODS OF RA WILL LOWER VSBYS. THIS RAIN
WILL MIX WITH SOME SNOW IN THE HIGHER TERRAIN OF NW MA AND SRN NH
ESPECIALLY LATE TUE NIGHT AND WED NIGHT. NE WINDS MAY GUST TO 35
KT OVER THE CAPE AND ISLANDS...WITH GUSTS TO 30 KT POSSIBLE OVER
THE SE COASTAL PLAIN.
THURSDAY...CONDITIONS IMPROVE TO VFR. HOWEVER GUSTY WINDS LIKELY
TO CONTINUE OUT OF THE NNW.
&&
.MARINE...
TONIGHT INTO SUNDAY...
SEAS WILL BUILD AS SW FLOW ACCELERATES OVER THE WATERS WITH GUSTS 25
TO 30 KTS. SW WINDS AT 925 MB INCREASE TO 45 TO 50 KTS LATE THIS
EVENING AND OVER THE RELATIVELY WARM OCEAN WATERS SOME OF THIS IS
EXPECTED TO MIX DOWN. AS A RESULT HAVE HOISTED A GALE WARNING FOR
ALL COASTAL WATERS EXCEPT BOSTON HARBOR AND NARRAGANSETT
BAY...STARTING LATE THIS EVENING AND RUNNING THROUGH SUNDAY.
FREQUENT GUSTS TO 35 KTS ARE EXPECTED...EXCEPT GUSTS TO 30 KTS
BOSTON HARBOR AND NARRAGANSETT BAY.
OPTED TO CONTINUE TO GO HIGHER THAN WNAWAVE GUIDANCE FOR BUZZARDS
BAY...VINEYARD SOUND AND NANTUCKET SOUND BASED ON OBSERVATIONS FROM
THIS AFTERNOON. MAIN CONCERN WILL BE PERIODS WHEN OUTGOING TIDE
COINCIDES WITH THE STRONG SW WINDS FOR BUZZARDS BAY AND VINEYARD
SOUND...CREATING ROUGH SEAS AND STEEP WAVES. THIS PROMPTED
FORECAST SEAS OF 4 TO 7 FEET FOR THOSE MARINE ZONES FOR TONIGHT
INTO SUNDAY.
SUNDAY NIGHT INTO MONDAY... WIND GUSTS GENERALLY DIMINISHING BELOW
25 KTS LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING...THOUGH DURING
MONDAY A FEW GUSTS TO 25 KTS MAY OCCUR ON THE OUTER COASTAL WATERS.
SEAS WILL STILL REMAIN CHOPPY ON THE OUTER COASTAL WATERS WITH 5 TO
7 FOOT SEAS.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MON NIGHT INTO TUE...
WINDS AND SEAS GENERALLY REMAIN BELOW SCA. HIGH PRES DOMINATING
OVER THE WATERS.
TUE NIGHT INTO WED NIGHT...
LOW PRES MOVING IN FROM THE OH VALLEY. WINDS AND SEAS GRADUALLY
INCREASING. GALES POSSIBLE ESPECIALLY DURING THE DAY WED INTO WED
NIGHT. OTHERWISE SCA/S WILL BE NEEDED.
THU...
WINDS GRADUALLY DROP TO SCA DURING THE DAY. SCA LIKELY NEEDED FOR
BOTH WINDS AND SEAS.
&&
.TIDES/COASTAL FLOODING...
STRONG EAST TO NORTHEAST WINDS EXPECTED WEDNESDAY IN ADVANCE OF
DEVELOPING LOW PRESSURE THAT SHOULD PASS SOUTH OF NEW ENGLAND.
SURFACE PRESSURE FALLS OF 1 TO 2 MB PER HOUR AND WINDS AT 925 MB
OF 30 TO 40 KNOTS ARE FORECAST. WAVE MODELS ARE FORECASTING 10 TO
12 FOOT SEAS EAST OF CAPE COD AND STELLWAGEN BANK. MEANWHILE
ASTRONOMICAL TIDES AT BOSTON ARE EXPECTED TO BE HIGH WITH A PEAK
ASTRO TIDE OF 11.6 FEET WEDNESDAY MORNING AND 12.0 FEET
THANKSGIVING MORNING.
THIS SCENARIO BEARS WATCHING FOR POTENTIAL BEACH EROSION AND MINOR
COASTAL FLOODING...ESPECIALLY ALONG THE EASTERN MASSACHUSETTS
COAST.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ231>235-237-
250-251-254>256.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ230-
236.
&&
$$
SYNOPSIS...DOODY/NMB
NEAR TERM...SIPPRELL
SHORT TERM...NMB
LONG TERM...DOODY
AVIATION...DOODY/SIPPRELL
MARINE...DOODY/NMB
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
920 AM EST SUN NOV 20 2011
.UPDATE...DEEP LAYER RIDGING IS LOCATED JUST OFF THE NE FL COAST
ACCORDING TO LATEST RUC ANALYSIS. SFC RIDGE IS ACROSS ERN GA/SC
AND INTO THE WRN ATLC WITH WEAK ONSHORE FLOW PER MSAS ANALYSIS.
WEAK INVERTED TROUGHING NOTED NEAR THE COAST. SKIES ARE MOSTLY
CLEAR TO PARTLY CLOUDY WITH MOSTLY CLOUDY CONDS JUST TO THE W OF
THE AREA IN ASSOCIATION WITH A WEAK SHORTWAVE TROUGH BUT NO
OBVIOUS SFC REFLECTION NOTED WITH THIS FEATURE. SFC OBS IN THE
AREA SHOW PATCHY DENSE FOG HAS DISSIPATED.
FCST FOR REST OF TODAY...WEAK SFC RIDGE REMAINS N OF THE AREA AND
LLVL WINDS REMAIN E TO SE AROUND 5-10 MPH UP TO 15 MPH. WITH
PARTLY SUNNY SKIES AND WARM ADVECTION TEMPS WILL RISE TO UPPER 70S
TO THE LOWER 80S...WITH SLIGHTLY COOLER CONDS IN MID 70S NEAR THE COAST.
THE WEAK SHORTWAVE TROUGH WILL CONT TO PRESS EWD WITH A FAIRLY
NARROW RIBBON OF MOISTURE ORIENTED SW-NE PUSHING INTO THE SE GA
ZONES. RADAR SHOWS ASSOCD SHOWER ACTIVITY WITH THE SHORTWAVE IS
LIGHT AND EXPECT THIS TO PERSIST AND THUS KEEPING ONLY 20% POPS FOR
SE GA TODAY...PERHAPS REACHING INTO A SMALL PART OF SUWANNEE
VALLEY AREA.
TONIGHT...AREAS OF FOG EXPECTED TO DEVELOP AFTER MIDNIGHT WITH A
GOOD CHANCE OF DENSE FOG FORMING BY EARLY MORNING GIVEN SFC WINDS
BECOMING NEAR CALM AND MORE THAN SUFFICIENT BOUNDARY LAYER
MOISTURE. CURRENT FCST HANDLES THIS WELL.
&&
.AVIATION...SCT-BKN CU EXPECTED TODAY WITH POSSIBLE MVFR CIGS NEAR
3 KFT. MAIN ISSUE NEXT 24 HRS WILL BE LATE TONIGHT FOG WITH MVFR BR
POSSIBLE BY 03Z-05Z THEN VLIFR PROGGED AFTER 06Z.
&&
.MARINE...WINDS ARE ELY AROUND 10-15 KT AND SEAS UP TO 3-5 FT. MAY
BE SOME 5-6 FT SEAS OVER OFFSHORE WATERS SO WILL KEEP SCEC
OFFSHORE HEADLINE IN PLACE. MOST OF WAVE ENERGY IS IN THE SWELL
PORTION WITH PERIODS OF 7-9 SECONDS AND WILL INDICATE IN UPDATED
CWF. MAIN IMPACT IN NEXT 24 HRS WILL BE DENSE FOG THAT WILL BE
LIKELY ALONG THE COAST EARLY MONDAY MORNING.
RIP CURRENTS: STILL HAZARDOUS SURF AT TIMES TODAY DUE TO THE SWELL
ENERGY COMING INTO THE SURF ZONE AND SANDBARS CREATED FROM PRIOR
DAYS SURF CONDITIONS. MODERATE RISK OF RIP CURRENTS TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 78 56 81 57 / 20 20 10 10
SSI 75 61 77 61 / 10 10 10 10
JAX 79 59 80 59 / 10 10 10 0
SGJ 78 63 77 62 / 10 10 10 0
GNV 82 59 82 57 / 10 10 10 0
OCF 83 60 83 59 / 10 10 10 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
SHASHY/MCALLISTER
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
412 PM EST SUN NOV 20 2011
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL CAUSE A FEW SHOWERS THIS
AFTERNOON INTO THE EVENING HOURS. OTHERWISE...HIGH PRESSURE
COVERING THE AREA WILL MOVE EAST TONIGHT AND MONDAY. A COLD FRONT
WILL APPROACH FROM THE WEST MONDAY AND TUESDAY INCREASING THE
CHANCES FOR SHOWERS BY TUESDAY. A FEW THUNDERSTORMS ARE ALSO
POSSIBLE TUESDAY AFTERNOON AND TUESDAY EVENING. THE COLD FRONT
WILL MOVE THROUGH WEDNESDAY WITH A GOOD CHANCE OF SHOWERS...
MAINLY IN THE MORNING. THANKSGIVING DAY WILL BE MOSTLY SUNNY
WITH DRY WEATHER EXPECTED.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPDATE...DUE TO CURRENT RAINFALL MOVING ACROSS THE MIDLANDS...HAVE
UPPED POPS ACROSS THE CENTRAL AND EASTERN COUNTIES TO CATEGORICAL
FOR THE NEXT FEW HOURS. TEMPS AND CLOUDS HAVE ALSO BEEN ADJUSTED
ACCORDINGLY.
PREVIOUS DISCUSSION...BOTH THE RUC AND NAM MODELS SHOW A WEAK
SHORT WAVE MOVING ACROSS THE REGION THIS AFTERNOON INTO THE
EVENING HOURS. LIKE THE 12 KM NAM 3 HOURLY POPS SHOWING A 20-30
PERCENT CHANCE OF SHOWERS THIS AFTERNOON AND A 20 PERCENT CHANCE
MAINLY IN NORTHERN AND WESTERN LOCATIONS THIS EVENING. THEN
AREAS OF FOG ARE EXPECTED TO DEVELOP AFTER MIDNIGHT WITH THE HIGH
MOISTURE CONTENT OF THE ATMOSPHERE. LOWS SHOULD BE IN THE MIDDLE
50S TONIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
HIGH PRESSURE WILL CONTINUE TO MOVE TO THE EAST AS A SHORT WAVE
AND AN ASSOCIATED COLD FRONT APPROACH FROM THE WEST MONDAY NIGHT
AND TUESDAY. A HIGH AMOUNT OF CLOUD COVER SHOULD KEEP AFTERNOON
HIGHS FROM REACHING THE 80 DEGREE MARK BUT NOT BY MUCH. WILL GO
MIDDLE TO UPPER 70S MONDAY AND TUESDAY. WILL INTRODUCE A SLIGHT
CHANCE OF SHOWERS TUESDAY AFTERNOON WITH THUNDERSTORMS POSSIBLE
TUESDAY AFTERNOON AND TUESDAY EVENING WITH THE MOST UNSTABLE
CONDITIONS DURING THIS PERIOD. LATER TUESDAY NIGHT...WILL JUST
MENTION SHOWERS. CHANCES INCREASE FROM 30 PERCENT TO 50 PERCENT
TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MEDIUM RANGE MODELS IN GOOD AGREEMENT MOVING SHORT WAVE AND
ASSOCIATED COLD FRONT THROUGH AREA WEDNESDAY. A GOOD CHANCE OF
SHOWERS EARLY WEDNESDAY...THEN CHANCES DECREASE DURING THE DAY
AS A COLD FRONT MOVES EAST. DECIDED TO NOT MENTION THUNDER
WEDNESDAY AS FRONT MOVES THROUGH EARLY. HIGH PRESSURE BUILDS OVER
THE REGION THANKSGIVING DAY THROUGH SATURDAY AS NEXT SYSTEM
APPEARS TO BE LATER THAN SATURDAY. HIGHS WEDNESDAY IN THE LOWER
70S COOL TO THE LOWER TO MIDDLE 60S THURSDAY THROUGH SATURDAY.
OVERNIGHT LOWS IN THE 40S WEDNESDAY NIGHT DROP TO THE 30S THURSDAY
NIGHT BUT ARE BACK UP AROUND 40 FOR FRIDAY NIGHT.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
UPDATE...BATCH OF RAIN HAS SHIFTED EAST OF THE TERMINALS AND IS
SHOWING A TREND TOWARDS DECREASING IN INTENSITY AND COVERAGE.
LOWER VSBYS/CIGS AT DNL/AGS REMAIN...THOUGH VSBYS/CIGS AT CAE/CUB
HAVE IMPROVED. WILL MAINTAIN PERSISTENCE IN THE SHORT TERM AND
EXPECT SOME IMPROVEMENT EARLY THIS EVENING. DETERIORATING
CONDITIONS POSSIBLE AGAIN LATE TONIGHT. MODELS ARE SUGGESTING IFR
VSBYS/CIGS AFTER 08Z. VFR CONDITIONS RETURN BY 14Z MONDAY.
EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR IFR CEILING MAY OCCUR
TUESDAY NIGHT INTO WEDNESDAY ASSOCIATED WITH THE APPROACH OF A
FRONTAL SYSTEM FROM THE NORTHWEST.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AVIATION...DCM
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
319 PM EST SUN NOV 20 2011
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL CAUSE A FEW SHOWERS THIS
AFTERNOON INTO THE EVENING HOURS. OTHERWISE...HIGH PRESSURE
COVERING THE AREA WILL MOVE EAST TONIGHT AND MONDAY. A COLD FRONT
WILL APPROACH FROM THE WEST MONDAY AND TUESDAY INCREASING THE
CHANCES FOR SHOWERS BY TUESDAY. A FEW THUNDERSTORMS ARE ALSO
POSSIBLE TUESDAY AFTERNOON AND TUESDAY EVENING. THE COLD FRONT
WILL MOVE THROUGH WEDNESDAY WITH A GOOD CHANCE OF SHOWERS...
MAINLY IN THE MORNING. THANKSGIVING DAY WILL BE MOSTLY SUNNY
WITH DRY WEATHER EXPECTED.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPDATE...DUE TO CURRENT RAINFALL MOVING ACROSS THE MIDLANDS...HAVE
UPPED POPS ACROSS THE CENTRAL AND EASTERN COUNTIES TO CATEGORICAL
FOR THE NEXT FEW HOURS. TEMPS AND CLOUDS HAVE ALSO BEEN ADJUSTED
ACCORDINGLY.
PREVIOUS DISCUSSION...BOTH THE RUC AND NAM MODELS SHOW A WEAK
SHORT WAVE MOVING ACROSS THE REGION THIS AFTERNOON INTO THE
EVENING HOURS. LIKE THE 12 KM NAM 3 HOURLY POPS SHOWING A 20-30
PERCENT CHANCE OF SHOWERS THIS AFTERNOON AND A 20 PERCENT CHANCE
MAINLY IN NORTHERN AND WESTERN LOCATIONS THIS EVENING. THEN
AREAS OF FOG ARE EXPECTED TO DEVELOP AFTER MIDNIGHT WITH THE HIGH
MOISTURE CONTENT OF THE ATMOSPHERE. LOWS SHOULD BE IN THE MIDDLE
50S TONIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
HIGH PRESSURE WILL CONTINUE TO MOVE TO THE EAST AS A SHORT WAVE
AND AN ASSOCIATED COLD FRONT APPROACH FROM THE WEST MONDAY NIGHT
AND TUESDAY. A HIGH AMOUNT OF CLOUD COVER SHOULD KEEP AFTERNOON
HIGHS FROM REACHING THE 80 DEGREE MARK BUT NOT BY MUCH. WILL GO
MIDDLE TO UPPER 70S MONDAY AND TUESDAY. WILL INTRODUCE A SLIGHT
CHANCE OF SHOWERS TUESDAY AFTERNOON WITH THUNDERSTORMS POSSIBLE
TUESDAY AFTERNOON AND TUESDAY EVENING WITH THE MOST UNSTABLE
CONDITIONS DURING THIS PERIOD. LATER TUESDAY NIGHT...WILL JUST
MENTION SHOWERS. CHANCES INCREASE FROM 30 PERCENT TO 50 PERCENT
TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MEDIUM RANGE MODELS IN GOOD AGREEMENT MOVING SHORT WAVE AND
ASSOCIATED COLD FRONT THROUGH AREA WEDNESDAY. A GOOD CHANCE OF
SHOWERS EARLY WEDNESDAY...THEN CHANCES DECREASE DURING THE DAY
AS A COLD FRONT MOVES EAST. DECIDED TO NOT MENTION THUNDER
WEDNESDAY AS FRONT MOVES THROUGH EARLY. HIGH PRESSURE BUILDS OVER
THE REGION THANKSGIVING DAY THROUGH SATURDAY AS NEXT SYSTEM
APPEARS TO BE LATER THAN SATURDAY. HIGHS WEDNESDAY IN THE LOWER
70S COOL TO THE LOWER TO MIDDLE 60S THURSDAY THROUGH SATURDAY.
OVERNIGHT LOWS IN THE 40S WEDNESDAY NIGHT DROP TO THE 30S THURSDAY
NIGHT BUT ARE BACK UP AROUND 40 FOR FRIDAY NIGHT.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE NOW WELL OFF THE ATLANTIC COAST WITH A FRONTAL SYSTEM
IN THE OHIO VALLEY. PATCHY LIGHT SHOWERS ACROSS THE CSRA AND
PORTIONS OF THE CENTRAL MIDLANDS WILL PERSIST FOR THE NEXT COUPLE OF
HOURS DUE TO A WEAK UPPER-LEVEL DISTURBANCE. OTHERWISE VFR THROUGH
THE DAY WITH LIGHT S-SW WINDS AND CONTINUED MID LEVEL CLOUDS.
MODELS ARE STRONGLY SUGGESTING POSSIBLE IFR VSBYS/CIGS AFTER
08Z...ESPECIALLY AGS/DNL/OGB...ESPECIALLY IF LOW-LEVEL NOCTURNAL JET
DOES NOT DEVELOP. VFR CONDITIONS RETURN BY 14Z MONDAY WITH BKN CIGS
AROUND 4000 FT.
EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR IFR CEILING MAY OCCUR
TUESDAY NIGHT INTO WEDNESDAY ASSOCIATED WITH THE APPROACH OF A
FRONTAL SYSTEM FROM THE NORTHWEST.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
149 PM EST SUN NOV 20 2011
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL CAUSE A FEW SHOWERS THIS
AFTERNOON INTO THE EVENING HOURS. OTHERWISE...HIGH PRESSURE
COVERING THE AREA WILL MOVE EAST TONIGHT AND MONDAY. A COLD FRONT
WILL APPROACH FROM THE WEST MONDAY AND TUESDAY INCREASING THE
CHANCES FOR SHOWERS BY TUESDAY. A FEW THUNDERSTORMS ARE ALSO
POSSIBLE TUESDAY AFTERNOON AND TUESDAY EVENING. THE COLD FRONT
WILL MOVE THROUGH WEDNESDAY WITH A GOOD CHANCE OF SHOWERS...
MAINLY IN THE MORNING. THANKSGIVING DAY WILL BE MOSTLY SUNNY
WITH DRY WEATHER EXPECTED.
&&
.NEAR TERM /THROUGH TONIGHT/...
BOTH THE RUC AND NAM MODELS SHOW A WEAK SHORT WAVE MOVING ACROSS
THE REGION THIS AFTERNOON INTO THE EVENING HOURS. LIKE THE 12 KM
NAM 3 HOURLY POPS SHOWING A 20-30 PERCENT CHANCE OF SHOWERS THIS
AFTERNOON AND A 20 PERCENT CHANCE MAINLY IN NORTHERN AND WESTERN
LOCATIONS THIS EVENING. THE NAM ALSO HAD A 40 PERCENT POP THIS
AFTERNOON NEAR AGS BUT JUST BRIEFLY. THEN AREAS OF FOG ARE
EXPECTED TO DEVELOP AFTER MIDNIGHT WITH THE HIGH MOISTURE CONTENT
OF THE ATMOSPHERE. LOWS SHOULD BE IN THE MIDDLE 50S TONIGHT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
HIGH PRESSURE WILL CONTINUE TO MOVE TO THE EAST AS A SHORT WAVE
AND AN ASSOCIATED COLD FRONT APPROACH FROM THE WEST MONDAY NIGHT
AND TUESDAY. A HIGH AMOUNT OF CLOUD COVER SHOULD KEEP AFTERNOON
HIGHS FROM REACHING THE 80 DEGREE MARK BUT NOT BY MUCH. WILL GO
MIDDLE TO UPPER 70S MONDAY AND TUESDAY. WILL INTRODUCE A SLIGHT
CHANCE OF SHOWERS TUESDAY AFTERNOON WITH THUNDERSTORMS POSSIBLE
TUESDAY AFTERNOON AND TUESDAY EVENING WITH THE MOST UNSTABLE
CONDITIONS DURING THIS PERIOD. LATER TUESDAY NIGHT...WILL JUST
MENTION SHOWERS. CHANCES INCREASE FROM 30 PERCENT TO 50 PERCENT
TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MEDIUM RANGE MODELS IN GOOD AGREEMENT MOVING SHORT WAVE AND
ASSOCIATED COLD FRONT THROUGH AREA WEDNESDAY. A GOOD CHANCE OF
SHOWERS EARLY WEDNESDAY...THEN CHANCES DECREASE DURING THE DAY
AS A COLD FRONT MOVES EAST. DECIDED TO NOT MENTION THUNDER
WEDNESDAY AS FRONT MOVES THROUGH EARLY. HIGH PRESSURE BUILDS OVER
THE REGION THANKSGIVING DAY THROUGH SATURDAY AS NEXT SYSTEM
APPEARS TO BE LATER THAN SATURDAY. HIGHS WEDNESDAY IN THE LOWER
70S COOL TO THE LOWER TO MIDDLE 60S THURSDAY THROUGH SATURDAY.
OVERNIGHT LOWS IN THE 40S WEDNESDAY NIGHT DROP TO THE 30S THURSDAY
NIGHT BUT ARE BACK UP AROUND 40 FOR FRIDAY NIGHT.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE NOW WELL OFF THE ATLANTIC COAST WITH A FRONTAL SYSTEM
IN THE OHIO VALLEY. PATCHY LIGHT SHOWERS ACROSS THE CSRA AND
PORTIONS OF THE CENTRAL MIDLANDS WILL PERSIST FOR THE NEXT COUPLE OF
HOURS DUE TO A WEAK UPPER-LEVEL DISTURBANCE. OTHERWISE VFR THROUGH
THE DAY WITH LIGHT S-SW WINDS AND CONTINUED MID LEVEL CLOUDS.
MODELS ARE STRONGLY SUGGESTING POSSIBLE IFR VSBYS/CIGS AFTER
08Z...ESPECIALLY AGS/DNL/OGB...ESPECIALLY IF LOW-LEVEL NOCTURNAL JET
DOES NOT DEVELOP. VFR CONDITIONS RETURN BY 14Z MONDAY WITH BKN CIGS
AROUND 4000 FT.
EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR IFR CEILING MAY OCCUR
TUESDAY NIGHT INTO WEDNESDAY ASSOCIATED WITH THE APPROACH OF A
FRONTAL SYSTEM FROM THE NORTHWEST.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...07
NEAR TERM...07
SHORT TERM...07
LONG TERM...07
AVIATION...22
AREA FORECAST DISCUSSION...CORRECTION
NWS NORTHERN INDIANA
859 PM EST MON NOV 21 2011
.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 INTERATIONS
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...MARSILI
UPDATE...MARSILI
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
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 INTIAL 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 INTERATIONS
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...MARSILI
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
333 PM EST SUN NOV 20 2011
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN NEARLY STATIONARY ACROSS THE LOWER
OHIO VALLEY THROUGH MONDAY EVENING...KEEPING SKIES CLOUDY ALONG WITH
PERIODIC CHANCES FOR RAIN. A STRONG WAVE OF LOW PRESSURE WILL TRACK
ALONG THE FRONT AND INTO THE REGION ON TUESDAY...WITH WIDESPREAD
RAIN AND A FEW THUNDERSTORMS ANTICIPATED. RAIN WILL END TUESDAY
NIGHT AS THE FRONT PULLS AWAY TO THE EAST. LARGE HIGH PRESSURE WILL
BUILD IN FOR THE SECOND HALF OF THE WEEK WITH DRY AND MILD WEATHER
FOR CENTRAL INDIANA. THE CHANCE FOR RAIN WILL RETURN NEXT WEEKEND AS
A FRONTAL BOUNDARY APPROACHES FROM THE WEST.
&&
.NEAR TERM /TONIGHT/...
COLD FRONT HAS MOVED SOUTH OF THE FORECAST AREA AS OF MID
AFTERNOON...RUNNING ALONG THE OHIO RIVER. AREA OF STEADIER RAINFALL
PROGRESSING EASTWARD ACROSS MUCH OF THE SOUTHERN HALF OF THE
FORECAST AREA THIS AFTERNOON ASSOCIATED WITH A WAVE OF LOW PRESSURE
TRAVERSING THE BOUNDARY. TEMPS WERE GENERALLY IN THE UPPER 40S AND
LOWER 50S AS OF 19Z.
FOCUS TONIGHT IS ON PRECIP CHANCES AS FRONT BECOMES NEARLY
STATIONARY JUST SOUTH OF THE OHIO RIVER. WAVES OF STEADIER RAINFALL
WILL CONTINUE TO IMPACT MAINLY AREAS SOUTH OF I-70 INTO THE EVENING
AS WEAK DISTURBANCES RIDE ALONG THE BOUNDARY. ISENTROPIC LIFT AND
DEEPER MOISTURE WILL REMAIN FOCUSED OVER FAR SOUTHERN COUNTIES IN
CLOSER PROXIMITY TO THE BOUNDARY. FURTHER TO THE NORTH...INFLUENCE
OF HIGH PRESSURE MOVING THROUGH THE GREAT LAKES WILL SERVE TO LIMIT
MOISTURE IN THE LOWER LEVELS AND WITH A LACK OF SIGNIFICANT
FORCING...HAVE A HARD TIME SEEING MORE THAN LIGHT WIDELY SCATTERED
SHOWERS AT LEAST THROUGH MIDNIGHT. WILL CONTINUE TO CARRY HIGHEST
POPS IN FAR SOUTHERN COUNTIES THROUGH THE EVENING WITH CHANCE POPS
ELSEWHERE.
AS THE CENTER OF THE HIGH SHIFTS INTO QUEBEC LATE TONIGHT...MOISTURE
WILL RETURN NORTH IN RETURN FLOW ALOFT IN WAKE OF THE HIGH. AXIS OF
ISENTROPIC LIFT THROUGH ABOUT 700MB WILL LIFT INTO THE NORTHERN HALF
OF THE FORECAST AREA DURING THE SECOND HALF OF THE NIGHT...AND MAY
BE ENOUGH TO GENERATE ADDITIONAL LIGHT RAIN SHOWERS TOWARDS
DAYBREAK. WILL THEREFORE MAINTAIN CHANCE POPS ACROSS ENTIRE FORECAST
AREA AFTER MIDNIGHT. SATURATED BOUNDARY LAYER CONDITIONS WILL
MAINTAIN THICK STRATOCU DECK ALL NIGHT.
TEMPS...WITH PRESENCE OF CLOUDS...POCKETS OF PRECIP AND DEEP LOW
LEVEL MOISTURE...DO NOT EXPECT TEMPS TO FALL MUCH MORE THAN FIVE
DEGREES OR SO FROM LATE AFTERNOON READINGS. MAV GUIDANCE LOOKED
REASONABLE.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
FORECAST CHALLENGES FOCUS ON PRECIP CHANCES THROUGH TUESDAY NIGHT.
MODEL GUIDANCE HAS LARGELY SHIFTED NORTH WITH THE TRACK OF THE
SURFACE WAVE ON TUESDAY...WITH THE LOW MOVING ACROSS THE FORECAST
AREA DURING THE AFTERNOON. WITH THE UPPER TROUGH COMING IN MORE
AMPLIFIED...THE NORTHERN TRACK OF THE LOW SEEMS VERY REASONABLE.
STILL SOME MINOR TIMING DIFFERENCES BETWEEN MODELS WITH THE LOW BUT
THIS SHOULD ONLY IMPACT START AND ENDING TIMES TO THE PRECIP.
ESSENTIALLY TOOK A BLEND OF THE 12Z SUITE OF DATA.
LOOKING INCREASINGLY MORE LIKELY THAT RAIN SHOWERS WILL REMAIN
LARGELY ISOLATED ON MONDAY ACROSS MUCH OF THE AREA IN THE ABSENCE OF
ANY SIGNIFICANT APPRECIABLE FORCING. AXIS OF ISENTROPIC LIFT WILL
PULL AWAY TO THE NORTHEAST DURING THE MORNING WITH DRIER AIR ALOFT
ASSOCIATED WITH A WEAK AREA OF HIGH PRESSURE SPREADING INTO THE
REGION DURING THE AFTERNOON. WHILE SCATTERED PRECIP MAY CONTINUE TO
PERIODICALLY IMPACT FAR SOUTHERN COUNTIES IN CLOSER PROXIMITY TO THE
STALLED BOUNDARY...SHOULD BE DRIER WEATHER ELSEWHERE ON MONDAY
ONCE THE DEEPER ISENTROPIC LIFT DEPARTS. WITH MOISTURE REMAINING
TRAPPED BELOW 5-6KFT HOWEVER...SKIES WILL REMAIN CLOUDY AND THE
PRESENCE OF THE DRYING ALOFT COULD ACTUALLY PROMOTE SOME POCKETS OF
DRIZZLE. FAR SOUTHERN COUNTIES REMAIN CLOSE ENOUGH TO ELEVATED
INSTABILITY AXIS TO MAINTAIN ISOLATED THUNDER MENTION DURING THE
AFTERNOON.
FOCUS WILL TURN TO THE SURFACE WAVE DEVELOPING OVER THE SOUTHERN
PLAINS MONDAY NIGHT AS A SHARP UPPER TROUGH SHIFTS EAST OUT OF THE
ROCKIES. APPROACH OF THE WAVE WILL FORCE THE FRONT TO LIFT BACK
NORTH LATE MONDAY NIGHT WITH WIDESPREAD RAINFALL EXPANDING INTO THE
SOUTHERN HALF OF THE FORECAST AREA PRIOR TO DAYBREAK AS STRONG LOW
LEVEL JET NOSES INTO THE REGION. RAINFALL WILL EXPAND ACROSS THE
ENTIRE FORECAST AREA ON TUESDAY MORNING AS ISENTROPIC LIFT AND
FORCING ALOFT STRENGTHEN AND HELP TO ADVECT DEEP GULF MOISTURE
ACROSS CENTRAL INDIANA. PRECIPITABLE WATER VALUES RISE TO 1.2-1.4
INCHES BY THE AFTERNOON WHICH WOULD BE 250-300% OF AVERAGE VALUES
FOR THIS TIME OF YEAR. LIFT WILL BE FURTHER ENHANCED BY DIFFLUENCE
IN THE MID AND UPPER LEVELS AND CONTINUED PRESENCE OF 60KT JET AT
850MB. HAVE INCREASED TO 100 POPS OVER THE ENTIRE FORECAST AREA.
WITH MORE NORTHERN TRACK TO SURFACE LOW AND PRESENCE OF INSTABILITY
THROUGH THE BOUNDARY LAYER...HAVE ALSO INSERTED THUNDER WORDING OVER
ALL OF CENTRAL INDIANA. POTENTIAL FOR WIDESPREAD ONE TO TWO INCHES
RAINFALL TOTALS WITH ISOLATED HIGHER AMOUNTS THROUGH TUESDAY EVENING
CONSIDERING ALL OF THE ABOVE THOUGHTS. THESE AMOUNTS WILL LIKELY
CAUSE LOCALIZED NUISANCE FLOODING ALONG WITH RISES ON ARE RIVERS AND
STREAMS. HOWEVER...DO NOT ANTICIPATE WIDESPREAD FLOODING PROBLEMS.
WILL HIGHLIGHT IN HWO.
LOW WILL SHIFT INTO OHIO TUESDAY EVENING WITH PRECIP LIKELY TO
PERSIST FOR MUCH OF THE EVENING AS MID LEVEL DEFORMATION AXIS
ROTATES ACROSS THE FORECAST AREA IN WAKE OF THE LOW AND FRONT.
PRECIP WILL END LATE TUESDAY NIGHT FROM WEST TO EAST AS DRIER AIR
RAPIDLY ADVECTS INTO THE REGION. MODEL SOUNDINGS INDICATE LOW CLOUDS
MAY NOT COMPLETELY DEPART UNTIL CLOSER TO DAYBREAK WEDNESDAY.
SUNSHINE WILL RETURN FOR WEDNESDAY AS HIGH PRESSURE EXPANDS ACROSS
THE OHIO VALLEY.
TEMPS...MAVMOS GUIDANCE LOOKS REASONABLE FOR HIGHS BOTH MONDAY AND
TUESDAY CONSIDERING BOUNDARY LAYER TEMPS AND PRESENCE OF WARM
ADVECTION. MUCH OF THE AREA LIKELY TO GET INTO THE 60S TUESDAY WITH
THE LOW MOVING FURTHER NORTH. HELD CLOSE TO MOS FOR LOWS THROUGH THE
PERIOD AS WELL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LARGE RIDGE OF HIGH PRESSURE OVER THE AREA WILL KEEP THE WEATHER DRY
WEDNESDAY NIGHT THROUGH FRIDAY. BY FRIDAY NIGHT A DEEP UPPER TROUGH
SHOULD START TO SWING OUT THE MOUNTAINS AND INTO THE PLAINS STATES
AND START PRODUCING SOME ISENTROPIC LIFT ACROSS THE AREA AHEAD OF A
COLD FRONT...BRINGING RAIN CHANCES IN FOR FRIDAY NIGHT. ALTHOUGH
THERE AREA SOME DIFFERENCES IN THE ECMWF AND GFS WITH THE EXACT
TIMING OF THE SYSTEM...WITH THE GFS BEING FASTER AND ECMWF SLOWER
AND INDIVIDUAL ENSEMBLE MEMBERS SUPPORTING EACH SOLUTION...THE
CONSENSUS OF THE MODELS AT THIS POINT IS TO BRING IN SOME
PRECIPITATION IN THE WESTERN AREA AT LEAST ON FRIDAY NIGHT. BY
SATURDAY AND INTO SATURDAY NIGHT THIS SHOULD OVERSPREAD THE AREA AND
MODELS ARE SHOWING BOTH STRONG LIFT AND AMPLE MOISTURE...THUS KEPT
THE LIKELIES GIVEN BY THE INITIALIZATION.
HIGH TEMPERATURES WILL RUN ABOVE NORMAL IN THE MIDDLE 50S THROUGH
THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 202100Z KIND TAF UPDATE/...
STILL QUITE A BIT OF RAIN UPSTREAM OVER ILLINOIS...SO PERIODS OF
LIGHT RAIN EXPECTED AT KIND UNTIL AT LEAST 210100Z. CEILINGS AROUND
015 FAIRLY WIDESPREAD UPSTREAM...SO WILL LOWER CEILINGS TO BELOW 020
FOR THE REST OF THE AFTERNOON. MAINLY MVFR VISIBILITY RESTRICTIONS
WITHIN THE RAIN AREAS...AS IT APPEARS THE HEAVIER RAIN AREAS WILL
REMAIN SOUTH OF KIND. PREVIOUS DISCUSSION FOLLOWS.
AT 17Z THE COLD FRONT HAS MOVED THROUGH THE SITES AND WINDS HAVE
SHIFTED TO NORTHWESTERLY AND THEN NORTHERLY. RAIN WILL CONTINUE FOR
THE MOST PART OVER KBMG FOR THE REMAINDER OF THE AFTERNOON BASED ON
UPSTREAM OBSERVATIONS...AND THE IFR OR LOWER CONDITIONS MAY NOT
IMPROVE. COULD SEE A BRIEF RISE TO MVFR THIS EVENING BUT UNCERTAINTY
FAIRLY HIGH. TIME HEIGHTS AND EXTRAPOLATION OF CURRENT CONDITIONS
INDICATE KIND AND KHUF WILL MAINLY SEE MVFR CEILINGS FOR THE REST OF
THE AFTERNOON AND TONIGHT BEFORE DROPPING TO IFR NEAR DAYBREAK
TOMORROW. WHILE RUC AND RADAR MOSAIC INDICATE SOME POTENTIAL FOR
SHOWERS AT THESE SITES...THE SPOTTY AND LIGHT NATURE OF THESE MEANS
WILL ONLY INCLUDE A VCSH FOR THE NEXT FEW HOURS AND NOT AN EXPLICIT
MENTION. UP AT KLAF COULD SEE SEVERAL HOURS OF VFR BEFORE DROPPING
TO MVFR OVERNIGHT BEING FURTHER AWAY FROM THE FORCING. WINDS WILL
VEER OVERNIGHT TO BE EASTERLY IN THE MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....CP
AVIATION...CP/JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
328 PM EST SUN NOV 20 2011
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
THE ACTIVE WEATHER PATTERN WILL BEGIN TODAY AS A COLD FRONT SLIDES
ACROSS CENTRAL INDIANA TRIGGERING THE FIRST PRECIP IN SEVERAL
DAYS. THIS FRONT WILL STALL OUT NEAR THE OHIO RIVER TONIGHT...
CONTINUING TO GENERATE RAINFALL OVER THE SOUTHERN HALF OF FORECAST
AREA THROUGH MID-WEEK. A REINFORCING LOW WILL TRAVEL ALONG THE
FRONTAL BOUNDARY ON TUESDAY BRINGING A CHANCE FOR ISOLATED
THUNDERSTORMS TO THE SOUTHERN COUNTIES.
&&
.NEAR TERM /REST OF TODAY/...
COLD FRONT MAKING STEADY SOUTHWARD PROGRESS ACROSS THE FORECAST
AREA THIS MORNING...AND AS OF 16Z WAS LOCATED ROUGHLY FROM
VINCENNES E/NE TO JUST SOUTH OF BLOOMINGTON AND SHELBYVILLE.
PRECIP WAS EXPANDING IN COVERAGE ACROSS THE SOUTHERN HALF OF THE
FORECAST AREA. TEMPERATURES WERE IN THE 40S NORTH AND WEST OF
INDIANAPOLIS WITH MAINLY 50S ELSEWHERE LATE THIS MORNING.
ADJUSTMENTS TO FORECAST FOR THE REST OF THE DAY FOCUSING ON TEMPS
AND PRECIP CHANCES. HAVE TRENDED MORE WITH THE RUC FOR THE
AFTERNOON AS 12Z NAM ALREADY STRUGGLING WITH NORTHWARD EXTENT TO
PRECIP SHIELD. WAVE OF LOW PRESSURE OVER NORTHEAST ARKANSAS WILL
TRAVERSE THE BOUNDARY THROUGH THE AFTERNOON AS THE FRONT SETTLES
NEAR THE OHIO RIVER BY LATE DAY. RAIN WILL CONTINUE TO EXPAND IN
COVERAGE ACROSS MUCH OF THE AREA ALONG AND SOUTH OF I-70 WITH
INCREASE IN LOW LEVEL MOISTURE AND ISENTROPIC LIFT PRESENT ACROSS
SOUTHERN HALF OF INDIANA. HAVE INCREASED TO LIKELY POPS ALL THE
WAY NORTH TO THE I-70 CORRIDOR WITH CATEGORICAL POPS OVER FAR
SOUTHERN COUNTIES IN CLOSEST PROXIMITY TO THE SOUTHWARD-MOVING
BOUNDARY. SHOULD BE A FAIRLY SHARP CUTOFF TO LIGHT PRECIP FURTHER
NORTH ACROSS FORECAST AREA AS LAYER OF LOW LEVEL MOISTURE BECOMES
SHALLOWER WITH GREATER PRESENCE OF DRIER AIR ALOFT.
HIGH TEMPS HAVE BEEN REACHED ALREADY TODAY FOR MUCH OF THE
FORECAST AREA. WITH SUBTLE COLD ADVECTION COMBINING WITH AN
ABUNDANCE OF LOW CLOUDS AND PRECIP FOR MOST LOCATIONS...
ANTICIPATE TEMPS WILL REMAIN STEADY OR SLOWLY FALL THROUGH THE
AFTERNOON. ONLY EXCEPTION TO THIS LIKELY TO BE OVER NORTHWEST
COUNTIES WHERE FRONTAL PASSAGE AND INITIAL TEMP DROP OCCURRED
AROUND DAYBREAK. MAY SEE CURRENT TEMPS IN MID 40S MANAGE TO WARM A
FEW DEGREES THROUGH THE AFTERNOON...PARTICULARLY WITH LESS
COVERAGE TO STRATOCU IN THESE AREAS. TOOK A BLEND OF OBSERVATIONS
SO FAR THIS MORNING AND RUC TEMP DATA TO CONSTITUTE THE NON-
DIURNAL SPREAD FOR THE REST OF THE DAY.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
THE MAIN FOCUS OF THE SHORT TERM IS CONTINUED RAIN AND
THUNDERSTORM POTENTIAL ON TUESDAY.
COLD FRONT WILL BE THROUGH CENTRAL INDIANA BY THIS EVENING AND
WILL STALL OUT NEAR THE OHIO RIVER TONIGHT. THIS WILL RESULT IN
CONTINUED RAINFALL OVER THE SOUTHERN HALF OF FORECAST AREA THROUGH
TUESDAY. THAT PORTION OF FORECAST AREA COULD PICK UP 2 TO 3 INCHES
OF RAINFALL BY THE END OF ALL OF THIS...POSSIBLY CREATING SOME SMALL
STREAM AND URBAN FLOODING PROBLEMS. IN REGARD TO THUNDERSTORMS FOR
TOMORROW...INSTABILITY IS NOT SUFFICIENT ENOUGH TO ADD MENTION OF
THUNDERSTORMS AT THIS TIME.
TUESDAY...A SURFACE LOW WILL MOVE ALONG THE STALLED FRONTAL
BOUNDARY BRINGING YET ANOTHER ROUND OF PRECIP...AGAIN MAINLY OVER
THE SOUTHERN PORTIONS OF FORECAST AREA. THIS SETUP LOOKS MORE
FAVORABLE THOUGH FOR THUNDERSTORMS ACROSS THE SOUTHERN COUNTIES AS
STRONG WARM ADVECTION AHEAD OF IT SPREADS ACROSS CENTRAL INDIANA.
INSTABILITY WILL INCREASE IN THIS WARM SECTOR WITH CAPES RANGING
FROM 500-1000J/KG. SURFACE LOW WILL MOVE THROUGH DURING PRIME
HOURS OF DAY...LATE AFTERNOON GENERATING ISOLATED THUNDERSTORMS
OVER SOUTHERN PORTIONS OF CENTRAL INDIANA.
TEMPS...WAS ABLE TO GO WITH A BLEND THROUGH MOST OF THE SHORT
TERM...EXCEPT FOR MONDAY NIGHT WHEN THE NAM TRENDED MUCH WARMER
THAN THE GFS. LIKED THE NAM DUE TO THE OVERCAST SKIES. ALSO LEANED
TOWARD THE WARMER SIDE OF GUIDANCE THROUGH MOST OF SHORT
TERM FOR DAYTIME HIGHS...ESPECIALLY ON TUESDAY WHEN SOUTHWEST FLOW IS
STRONGEST AHEAD OF SECOND SURFACE LOW.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
DRY WEATHER AND MODERATING TEMPERATURES SHOULD CHARACTERIZE THE
BEGINNING OF THE LONG TERM AND THROUGH FRIDAY AS HIGH PRESSURE
SLIDES EAST ACROSS THE OHIO VALLEY WEDNESDAY INTO THURSDAY FOLLOWED
BY ANOTHER ROUND OF STRONG RETURN FLOW WARM AIR ADVECTION AHEAD OF
AN APPROACHING COLD FRONT. THEN...SHOWER CHANCES WILL BE INCREASING
AHEAD OF A COLD FRONT THAT IS EXPECTED TO MOVE THROUGH ON SATURDAY.
THE 00Z OPERATIONAL GFS CONTINUES TO START OFF FASTER REGARDING HIGH
PRESSURE MOVING EAST ACROSS THE OHIO VALLEY AND THEN THE
APPALACHIANS. AFTER THAT...THE MODELS ALSO HAVE SOME DIFFERENCES
REGARDING THE LOCATIONS OF CENTERS OF SURFACE LOW PRESSURE ALONG AN
APPROACHING FRONTAL SYSTEM. HOWEVER...MODELS ARE CLOSE IN TIMING
REGARDING THE FRONTAL POSITION AND ASSOCIATED QPF WITH THE SYSTEM
WHICH JIVES WELL WITH THE INITIALIZATION EXTENDED...SO WILL LEAVE
POPS ALONE WITH WEDNESDAY THROUGH FRIDAY DRY AND CHANCE POPS FRIDAY
NIGHT AND SATURDAY.
TEMPERATURES WILL START OUT AROUND NORMAL ON WEDNESDAY IN THE UPPER
40S AND LOWER 50S BEFORE CLIMBING TO ABOVE NORMAL MOSTLY IN THE MID
AND UPPER 50S THE REMAINDER OF THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 202100Z KIND TAF UPDATE/...
STILL QUITE A BIT OF RAIN UPSTREAM OVER ILLINOIS...SO PERIODS OF
LIGHT RAIN EXPECTED AT KIND UNTIL AT LEAST 210100Z. CEILINGS AROUND
015 FAIRLY WIDESPREAD UPSTREAM...SO WILL LOWER CEILINGS TO BELOW 020
FOR THE REST OF THE AFTERNOON. MAINLY MVFR VISIBILITY RESTRICTIONS
WITHIN THE RAIN AREAS...AS IT APPEARS THE HEAVIER RAIN AREAS WILL
REMAIN SOUTH OF KIND. PREVIOUS DISCUSSION FOLLOWS.
AT 17Z THE COLD FRONT HAS MOVED THROUGH THE SITES AND WINDS HAVE
SHIFTED TO NORTHWESTERLY AND THEN NORTHERLY. RAIN WILL CONTINUE FOR
THE MOST PART OVER KBMG FOR THE REMAINDER OF THE AFTERNOON BASED ON
UPSTREAM OBSERVATIONS...AND THE IFR OR LOWER CONDITIONS MAY NOT
IMPROVE. COULD SEE A BRIEF RISE TO MVFR THIS EVENING BUT UNCERTAINTY
FAIRLY HIGH. TIME HEIGHTS AND EXTRAPOLATION OF CURRENT CONDITIONS
INDICATE KIND AND KHUF WILL MAINLY SEE MVFR CEILINGS FOR THE REST OF
THE AFTERNOON AND TONIGHT BEFORE DROPPING TO IFR NEAR DAYBREAK
TOMORROW. WHILE RUC AND RADAR MOSAIC INDICATE SOME POTENTIAL FOR
SHOWERS AT THESE SITES...THE SPOTTY AND LIGHT NATURE OF THESE MEANS
WILL ONLY INCLUDE A VCSH FOR THE NEXT FEW HOURS AND NOT AN EXPLICIT
MENTION. UP AT KLAF COULD SEE SEVERAL HOURS OF VFR BEFORE DROPPING
TO MVFR OVERNIGHT BEING FURTHER AWAY FROM THE FORCING. WINDS WILL
VEER OVERNIGHT TO BE EASTERLY IN THE MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...RYAN
SHORT TERM...TDUD
LONG TERM....MK
AVIATION...CP/JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1203 PM EST SUN NOV 20 2011
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
THE ACTIVE WEATHER PATTERN WILL BEGIN TODAY AS A COLD FRONT SLIDES
ACROSS CENTRAL INDIANA TRIGGERING THE FIRST PRECIP IN SEVERAL
DAYS. THIS FRONT WILL STALL OUT NEAR THE OHIO RIVER TONIGHT...
CONTINUING TO GENERATE RAINFALL OVER THE SOUTHERN HALF OF FORECAST
AREA THROUGH MID-WEEK. A REINFORCING LOW WILL TRAVEL ALONG THE
FRONTAL BOUNDARY ON TUESDAY BRINGING A CHANCE FOR ISOLATED
THUNDERSTORMS TO THE SOUTHERN COUNTIES.
&&
.NEAR TERM /REST OF TODAY/...
COLD FRONT MAKING STEADY SOUTHWARD PROGRESS ACROSS THE FORECAST
AREA THIS MORNING...AND AS OF 16Z WAS LOCATED ROUGHLY FROM
VINCENNES E/NE TO JUST SOUTH OF BLOOMINGTON AND SHELBYVILLE.
PRECIP WAS EXPANDING IN COVERAGE ACROSS THE SOUTHERN HALF OF THE
FORECAST AREA. TEMPERATURES WERE IN THE 40S NORTH AND WEST OF
INDIANAPOLIS WITH MAINLY 50S ELSEWHERE LATE THIS MORNING.
ADJUSTMENTS TO FORECAST FOR THE REST OF THE DAY FOCUSING ON TEMPS
AND PRECIP CHANCES. HAVE TRENDED MORE WITH THE RUC FOR THE
AFTERNOON AS 12Z NAM ALREADY STRUGGLING WITH NORTHWARD EXTENT TO
PRECIP SHIELD. WAVE OF LOW PRESSURE OVER NORTHEAST ARKANSAS WILL
TRAVERSE THE BOUNDARY THROUGH THE AFTERNOON AS THE FRONT SETTLES
NEAR THE OHIO RIVER BY LATE DAY. RAIN WILL CONTINUE TO EXPAND IN
COVERAGE ACROSS MUCH OF THE AREA ALONG AND SOUTH OF I-70 WITH
INCREASE IN LOW LEVEL MOISTURE AND ISENTROPIC LIFT PRESENT ACROSS
SOUTHERN HALF OF INDIANA. HAVE INCREASED TO LIKELY POPS ALL THE
WAY NORTH TO THE I-70 CORRIDOR WITH CATEGORICAL POPS OVER FAR
SOUTHERN COUNTIES IN CLOSEST PROXIMITY TO THE SOUTHWARD-MOVING
BOUNDARY. SHOULD BE A FAIRLY SHARP CUTOFF TO LIGHT PRECIP FURTHER
NORTH ACROSS FORECAST AREA AS LAYER OF LOW LEVEL MOISTURE BECOMES
SHALLOWER WITH GREATER PRESENCE OF DRIER AIR ALOFT.
HIGH TEMPS HAVE BEEN REACHED ALREADY TODAY FOR MUCH OF THE
FORECAST AREA. WITH SUBTLE COLD ADVECTION COMBINING WITH AN
ABUNDANCE OF LOW CLOUDS AND PRECIP FOR MOST LOCATIONS...
ANTICIPATE TEMPS WILL REMAIN STEADY OR SLOWLY FALL THROUGH THE
AFTERNOON. ONLY EXCEPTION TO THIS LIKELY TO BE OVER NORTHWEST
COUNTIES WHERE FRONTAL PASSAGE AND INITIAL TEMP DROP OCCURRED
AROUND DAYBREAK. MAY SEE CURRENT TEMPS IN MID 40S MANAGE TO WARM A
FEW DEGREES THROUGH THE AFTERNOON...PARTICULARLY WITH LESS
COVERAGE TO STRATOCU IN THESE AREAS. TOOK A BLEND OF OBSERVATIONS
SO FAR THIS MORNING AND RUC TEMP DATA TO CONSTITUTE THE NON-
DIURNAL SPREAD FOR THE REST OF THE DAY.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
THE MAIN FOCUS OF THE SHORT TERM IS CONTINUED RAIN AND
THUNDERSTORM POTENTIAL ON TUESDAY.
COLD FRONT WILL BE THROUGH CENTRAL INDIANA BY THIS EVENING AND
WILL STALL OUT NEAR THE OHIO RIVER TONIGHT. THIS WILL RESULT IN
CONTINUED RAINFALL OVER THE SOUTHERN HALF OF FORECAST AREA THROUGH
TUESDAY. THAT PORTION OF FORECAST AREA COULD PICK UP 2 TO 3 INCHES
OF RAINFALL BY THE END OF ALL OF THIS...POSSIBLY CREATING SOME SMALL
STREAM AND URBAN FLOODING PROBLEMS. IN REGARD TO THUNDERSTORMS FOR
TOMORROW...INSTABILITY IS NOT SUFFICIENT ENOUGH TO ADD MENTION OF
THUNDERSTORMS AT THIS TIME.
TUESDAY...A SURFACE LOW WILL MOVE ALONG THE STALLED FRONTAL
BOUNDARY BRINGING YET ANOTHER ROUND OF PRECIP...AGAIN MAINLY OVER
THE SOUTHERN PORTIONS OF FORECAST AREA. THIS SETUP LOOKS MORE
FAVORABLE THOUGH FOR THUNDERSTORMS ACROSS THE SOUTHERN COUNTIES AS
STRONG WARM ADVECTION AHEAD OF IT SPREADS ACROSS CENTRAL INDIANA.
INSTABILITY WILL INCREASE IN THIS WARM SECTOR WITH CAPES RANGING
FROM 500-1000J/KG. SURFACE LOW WILL MOVE THROUGH DURING PRIME
HOURS OF DAY...LATE AFTERNOON GENERATING ISOLATED THUNDERSTORMS
OVER SOUTHERN PORTIONS OF CENTRAL INDIANA.
TEMPS...WAS ABLE TO GO WITH A BLEND THROUGH MOST OF THE SHORT
TERM...EXCEPT FOR MONDAY NIGHT WHEN THE NAM TRENDED MUCH WARMER
THAN THE GFS. LIKED THE NAM DUE TO THE OVERCAST SKIES. ALSO LEANED
TOWARD THE WARMER SIDE OF GUIDANCE THROUGH MOST OF SHORT
TERM FOR DAYTIME HIGHS...ESPECIALLY ON TUESDAY WHEN SOUTHWEST FLOW IS
STRONGEST AHEAD OF SECOND SURFACE LOW.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
DRY WEATHER AND MODERATING TEMPERATURES SHOULD CHARACTERIZE THE
BEGINNING OF THE LONG TERM AND THROUGH FRIDAY AS HIGH PRESSURE
SLIDES EAST ACROSS THE OHIO VALLEY WEDNESDAY INTO THURSDAY FOLLOWED
BY ANOTHER ROUND OF STRONG RETURN FLOW WARM AIR ADVECTION AHEAD OF
AN APPROACHING COLD FRONT. THEN...SHOWER CHANCES WILL BE INCREASING
AHEAD OF A COLD FRONT THAT IS EXPECTED TO MOVE THROUGH ON SATURDAY.
THE 00Z OPERATIONAL GFS CONTINUES TO START OFF FASTER REGARDING HIGH
PRESSURE MOVING EAST ACROSS THE OHIO VALLEY AND THEN THE
APPALACHIANS. AFTER THAT...THE MODELS ALSO HAVE SOME DIFFERENCES
REGARDING THE LOCATIONS OF CENTERS OF SURFACE LOW PRESSURE ALONG AN
APPROACHING FRONTAL SYSTEM. HOWEVER...MODELS ARE CLOSE IN TIMING
REGARDING THE FRONTAL POSITION AND ASSOCIATED QPF WITH THE SYSTEM
WHICH JIVES WELL WITH THE INITIALIZATION EXTENDED...SO WILL LEAVE
POPS ALONE WITH WEDNESDAY THROUGH FRIDAY DRY AND CHANCE POPS FRIDAY
NIGHT AND SATURDAY.
TEMPERATURES WILL START OUT AROUND NORMAL ON WEDNESDAY IN THE UPPER
40S AND LOWER 50S BEFORE CLIMBING TO ABOVE NORMAL MOSTLY IN THE MID
AND UPPER 50S THE REMAINDER OF THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 20/18Z TAF ISSUANCE/...
AT 17Z THE COLD FRONT HAS MOVED THROUGH THE SITES AND WINDS HAVE
SHIFTED TO NORTHWESTERLY AND THEN NORTHERLY. RAIN WILL CONTINUE FOR
THE MOST PART OVER KBMG FOR THE REMAINDER OF THE AFTERNOON BASED ON
UPSTREAM OBSERVATIONS...AND THE IFR OR LOWER CONDITIONS MAY NOT
IMPROVE. COULD SEE A BRIEF RISE TO MVFR THIS EVENING BUT UNCERTAINTY
FAIRLY HIGH. TIME HEIGHTS AND EXTRAPOLATION OF CURRENT CONDITIONS
INDICATE KIND AND KHUF WILL MAINLY SEE MVFR CEILINGS FOR THE REST OF
THE AFTERNOON AND TONIGHT BEFORE DROPPING TO IFR NEAR DAYBREAK
TOMORROW. WHILE RUC AND RADAR MOSAIC INDICATE SOME POTENTIAL FOR
SHOWERS AT THESE SITES...THE SPOTTY AND LIGHT NATURE OF THESE MEANS
WILL ONLY INCLUDE A VCSH FOR THE NEXT FEW HOURS AND NOT AN EXPLICIT
MENTION. UP AT KLAF COULD SEE SEVERAL HOURS OF VFR BEFORE DROPPING
TO MVFR OVERNIGHT BEING FURTHER AWAY FROM THE FORCING. WINDS WILL
VEER OVERNIGHT TO BE EASTERLY IN THE MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...RYAN
SHORT TERM...TDUD
LONG TERM....MK
AVIATION...CP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1105 AM EST SUN NOV 20 2011
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
THE ACTIVE WEATHER PATTERN WILL BEGIN TODAY AS A COLD FRONT SLIDES
ACROSS CENTRAL INDIANA TRIGGERING THE FIRST PRECIP IN SEVERAL
DAYS. THIS FRONT WILL STALL OUT NEAR THE OHIO RIVER TONIGHT...
CONTINUING TO GENERATE RAINFALL OVER THE SOUTHERN HALF OF FORECAST
AREA THROUGH MID-WEEK. A REINFORCING LOW WILL TRAVEL ALONG THE
FRONTAL BOUNDARY ON TUESDAY BRINGING A CHANCE FOR ISOLATED
THUNDERSTORMS TO THE SOUTHERN COUNTIES.
&&
.NEAR TERM /REST OF TODAY/...
COLD FRONT MAKING STEADY SOUTHWARD PROGRESS ACROSS THE FORECAST
AREA THIS MORNING...AND AS OF 16Z WAS LOCATED ROUGHLY FROM
VINCENNES E/NE TO JUST SOUTH OF BLOOMINGTON AND SHELBYVILLE.
PRECIP WAS EXPANDING IN COVERAGE ACROSS THE SOUTHERN HALF OF THE
FORECAST AREA. TEMPERATURES WERE IN THE 40S NORTH AND WEST OF
INDIANAPOLIS WITH MAINLY 50S ELSEWHERE LATE THIS MORNING.
ADJUSTMENTS TO FORECAST FOR THE REST OF THE DAY FOCUSING ON TEMPS
AND PRECIP CHANCES. HAVE TRENDED MORE WITH THE RUC FOR THE
AFTERNOON AS 12Z NAM ALREADY STRUGGLING WITH NORTHWARD EXTENT TO
PRECIP SHIELD. WAVE OF LOW PRESSURE OVER NORTHEAST ARKANSAS WILL
TRAVERSE THE BOUNDARY THROUGH THE AFTERNOON AS THE FRONT SETTLES
NEAR THE OHIO RIVER BY LATE DAY. RAIN WILL CONTINUE TO EXPAND IN
COVERAGE ACROSS MUCH OF THE AREA ALONG AND SOUTH OF I-70 WITH
INCREASE IN LOW LEVEL MOISTURE AND ISENTROPIC LIFT PRESENT ACROSS
SOUTHERN HALF OF INDIANA. HAVE INCREASED TO LIKELY POPS ALL THE
WAY NORTH TO THE I-70 CORRIDOR WITH CATEGORICAL POPS OVER FAR
SOUTHERN COUNTIES IN CLOSEST PROXIMITY TO THE SOUTHWARD-MOVING
BOUNDARY. SHOULD BE A FAIRLY SHARP CUTOFF TO LIGHT PRECIP FURTHER
NORTH ACROSS FORECAST AREA AS LAYER OF LOW LEVEL MOISTURE BECOMES
SHALLOWER WITH GREATER PRESENCE OF DRIER AIR ALOFT.
HIGH TEMPS HAVE BEEN REACHED ALREADY TODAY FOR MUCH OF THE
FORECAST AREA. WITH SUBTLE COLD ADVECTION COMBINING WITH AN
ABUNDANCE OF LOW CLOUDS AND PRECIP FOR MOST LOCATIONS...
ANTICIPATE TEMPS WILL REMAIN STEADY OR SLOWLY FALL THROUGH THE
AFTERNOON. ONLY EXCEPTION TO THIS LIKELY TO BE OVER NORTHWEST
COUNTIES WHERE FRONTAL PASSAGE AND INITIAL TEMP DROP OCCURRED
AROUND DAYBREAK. MAY SEE CURRENT TEMPS IN MID 40S MANAGE TO WARM A
FEW DEGREES THROUGH THE AFTERNOON...PARTICULARLY WITH LESS
COVERAGE TO STRATOCU IN THESE AREAS. TOOK A BLEND OF OBSERVATIONS
SO FAR THIS MORNING AND RUC TEMP DATA TO CONSTITUTE THE NON-
DIURNAL SPREAD FOR THE REST OF THE DAY.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
THE MAIN FOCUS OF THE SHORT TERM IS CONTINUED RAIN AND
THUNDERSTORM POTENTIAL ON TUESDAY.
COLD FRONT WILL BE THROUGH CENTRAL INDIANA BY THIS EVENING AND
WILL STALL OUT NEAR THE OHIO RIVER TONIGHT. THIS WILL RESULT IN
CONTINUED RAINFALL OVER THE SOUTHERN HALF OF FORECAST AREA THROUGH
TUESDAY. THAT PORTION OF FORECAST AREA COULD PICK UP 2 TO 3 INCHES
OF RAINFALL BY THE END OF ALL OF THIS...POSSIBLY CREATING SOME SMALL
STREAM AND URBAN FLOODING PROBLEMS. IN REGARD TO THUNDERSTORMS FOR
TOMORROW...INSTABILITY IS NOT SUFFICIENT ENOUGH TO ADD MENTION OF
THUNDERSTORMS AT THIS TIME.
TUESDAY...A SURFACE LOW WILL MOVE ALONG THE STALLED FRONTAL
BOUNDARY BRINGING YET ANOTHER ROUND OF PRECIP...AGAIN MAINLY OVER
THE SOUTHERN PORTIONS OF FORECAST AREA. THIS SETUP LOOKS MORE
FAVORABLE THOUGH FOR THUNDERSTORMS ACROSS THE SOUTHERN COUNTIES AS
STRONG WARM ADVECTION AHEAD OF IT SPREADS ACROSS CENTRAL INDIANA.
INSTABILITY WILL INCREASE IN THIS WARM SECTOR WITH CAPES RANGING
FROM 500-1000J/KG. SURFACE LOW WILL MOVE THROUGH DURING PRIME
HOURS OF DAY...LATE AFTERNOON GENERATING ISOLATED THUNDERSTORMS
OVER SOUTHERN PORTIONS OF CENTRAL INDIANA.
TEMPS...WAS ABLE TO GO WITH A BLEND THROUGH MOST OF THE SHORT
TERM...EXCEPT FOR MONDAY NIGHT WHEN THE NAM TRENDED MUCH WARMER
THAN THE GFS. LIKED THE NAM DUE TO THE OVERCAST SKIES. ALSO LEANED
TOWARD THE WARMER SIDE OF GUIDANCE THROUGH MOST OF SHORT
TERM FOR DAYTIME HIGHS...ESPECIALLY ON TUESDAY WHEN SOUTHWEST FLOW IS
STRONGEST AHEAD OF SECOND SURFACE LOW.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
DRY WEATHER AND MODERATING TEMPERATURES SHOULD CHARACTERIZE THE
BEGINNING OF THE LONG TERM AND THROUGH FRIDAY AS HIGH PRESSURE
SLIDES EAST ACROSS THE OHIO VALLEY WEDNESDAY INTO THURSDAY FOLLOWED
BY ANOTHER ROUND OF STRONG RETURN FLOW WARM AIR ADVECTION AHEAD OF
AN APPROACHING COLD FRONT. THEN...SHOWER CHANCES WILL BE INCREASING
AHEAD OF A COLD FRONT THAT IS EXPECTED TO MOVE THROUGH ON SATURDAY.
THE 00Z OPERATIONAL GFS CONTINUES TO START OFF FASTER REGARDING HIGH
PRESSURE MOVING EAST ACROSS THE OHIO VALLEY AND THEN THE
APPALACHIANS. AFTER THAT...THE MODELS ALSO HAVE SOME DIFFERENCES
REGARDING THE LOCATIONS OF CENTERS OF SURFACE LOW PRESSURE ALONG AN
APPROACHING FRONTAL SYSTEM. HOWEVER...MODELS ARE CLOSE IN TIMING
REGARDING THE FRONTAL POSITION AND ASSOCIATED QPF WITH THE SYSTEM
WHICH JIVES WELL WITH THE INITIALIZATION EXTENDED...SO WILL LEAVE
POPS ALONE WITH WEDNESDAY THROUGH FRIDAY DRY AND CHANCE POPS FRIDAY
NIGHT AND SATURDAY.
TEMPERATURES WILL START OUT AROUND NORMAL ON WEDNESDAY IN THE UPPER
40S AND LOWER 50S BEFORE CLIMBING TO ABOVE NORMAL MOSTLY IN THE MID
AND UPPER 50S THE REMAINDER OF THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 20/12Z TAF ISSUANCE/...
AT 14Z THE COLD FRONT HAS TRAVELLED THROUGH ALL SITES BUT KBMG...AND
IS CURRENTLY ON THE DOORSTEP THERE. FOR THIS UPDATE ADDED RAIN TO
KBMG NOW AND LOWERED KIND TO IFR BASED ON CURRENT CONDITIONS THAT
COULD LAST FOR THE NEXT COUPLE OF HOURS UNTIL THE FRONT GETS FURTHER
SOUTH. PREVIOUS DISCUSSION FOLLOWS...
THE FRONT IS THEN EXPECTED TO STALL NEAR THE OHIO RIVER
TONIGHT. THUS...THERE SHOULD BE A SHARP CUTOFF WITH THE RAIN WITH
BMG HAVING THE HIGHEST CHANCES. SO...WENT -RA THERE THROUGH THE
DAY...VCSH AT IND AND HUF AND NOTHING AT LAF. LAF SHOULD ALSO SEE
VFR CONDITIONS BY 18Z WITH HUF AND IND NOT SEEING VFR TIL 23Z OR
LATER AND BMG LIKELY REMAINING MVFR THROUGH THE TAF PERIOD. HUF AND
IND SHOULD AGAIN BECOME MVFR TOWARD DAYBREAK TONIGHT AS A WAVE
SLIDES NORTHEAST ALONG THE FRONT.
WINDS WILL BECOME NORTHWEST AND THEN NORTH BEHIND THE FRONT THROUGH
THE MORNING HOURS AND FINALLY EAST OVERNIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...RYAN
SHORT TERM...TDUD
LONG TERM....MK
AVIATION...MK/CP
AREA FORECAST DISCUSSION
NWS TOPEKA KS
250 PM CST SUN NOV 20 2011
.DISCUSSION...
SURFACE RIDGING AND CLOUD COVER HAVE PREVENT TEMPS FROM WARMING UP
MUCH THIS AFTERNOON. 20Z SURFACE OBS CONTINUE TO SHOW COLD AIR
ADVECTING FROM THE NORTH WITH THE CENTER OF THE RIDGE OVER SOUTHERN
MN. ALOFT...WATER VAPOR SHOWS A CLOSED LOW OVER THE CA COAST AND
PROFILER DATA INDICATES A FAST SOUTHWEST FLOW OVER THE FORECAST AREA
WITH NO OBVIOUS WAVE WITHIN THE FLOW. HOWEVER THE RUC AND NAM
INDICATE A WEAK WAVE AT 700 MB MOVING ACROSS NORTHEAST KANSAS LATE
THIS AFTERNOON AND THIS EVENING. THIS MAY BE THE CAUSE OF THE
ENHANCED CLOUD COVER AND WEAK ECHOS ON RADAR ACROSS WESTERN KS.
THINK THAT THIS WILL NOT AMOUNT TO MUCH FOR TONIGHT DUE TO MID LEVEL
DRY AIR. MODELS SHOW THIS PASSING EAST WITH GENERAL SUBSIDENCE
TAKING OVER FOR MUCH OF THE NIGHT. ADDITIONALLY ISENTROPIC SURFACES
ARE NOT SHOWING MUCH LIFT EITHER. THEREFORE WILL CONTINUE WITH A DRY
FORECAST. CLOUD COVER COULD BE A LITTLE TRICKY TONIGHT AND HAVE A
LARGE EFFECT ON MIN TEMPS. THERE IS A GENERAL CONSENSUS THAT THE LOW
LEVEL RH OVER SOUTHERN MO AND SOUTHEAST KS WILL LIFT NORTH THROUGH
NORTHEAST KS OVERNIGHT. MEANWHILE SKIES COULD BECOME MOSTLY CLEAR
OVER CENTRAL KS. WITH THIS IN MIND HAVE DROPPED LOWS INTO THE LOWER
20S FROM MHK WEST AND LEFT LOWS IN THE LOWER 30S OVER FAR EASTERN KS
WHERE LOW CLOUDS ARE LIKELY TO HANG IN A LITTLE LONGER. FOR MONDAY
THINK TEMPS WILL WARM INTO THE MID 40S DUE TO NEUTRAL TEMP ADVECTION
AND SOME INSOLATION DURING THE DAY. MID LEVEL MOISTURE IS EXPECTED
TO BEGIN ADVECTING NORTH BY MONDAY AFTERNOON AS THE CLOSED LOW ON
THE WEST COAST MAKES ITS WAY OVER THE SOUTHERN ROCKIES. HAVE
INCLUDED SOME SLIGHT CHANCE POPS SOUTH OF I-70 DURING THE AFTERNOON
BECAUSE OF THIS.
WOLTERS
UPPER WAVE CONTINUES EAST AND NORTHEAST WHILE DEEPENING MONDAY
NIGHT. UPPER JET STREAKS FLANKING THE AREA TO THE NORTHEAST AND
SOUTHWEST INTO THE EVENING WITH DRY SLOT WORKING THROUGH SOUTHERN
KANSAS AND SOMEWHAT OF A WEAK TROWAL POKING INTO NORTHEAST KANSAS.
THERE REMAINS SOME DIFFERENCES ON THE TIMING OF THE SYSTEM WITH THE
12Z NAM ON THE FASTER END...BUT STILL APPEARS LATE EVENING THROUGH
EARLY MORNING TUESDAY WILL BE ON THE WET SIDE. DRY SLOT WILL HELP
AID CONVECTIVE CHANCES AND INSTABILITY STILL ENOUGH FOR THUNDER
INCLUSION FOR MUCH OF THE AREA. ALSO SOME CONCERN FOR FREEZING
PRECIP LATE IN THE EVENT AS SURFACE LOW PRESSURE MOVES THROUGH
SOUTHERN MISSOURI AND NORTH WINDS TAKE HOLD. WILL INTRODUCE A
FREEZING RAIN MENTION IN THE NORTHWEST. TUESDAY AFTERNOON AND NIGHT
BRING RAPIDLY IMPROVING CONDITIONS AS UPPER RIDGING BUILDS IN.
AIRMASS BEHIND THE SYSTEM NOT TERRIBLY COLD WITH DOWNSLOPE WINDS TO
THE NORTHWEST SO HIGHS SHOULD STILL REACH THE LOWER 50S TUESDAY AND
ON INTO THE UPPER 50S WEDNESDAY UNDER CLEAR SKIES AND INCREASING
SOUTH WINDS.
65
EXTENDED FORECAST (WEDNESDAY NIGHT THROUGH SUNDAY)
SOUTHERLY FLOW...WARM AIR ADVECTION AND UPPER LEVEL RIDGING WILL
RETURN TO THE CENTRAL U.S. ON THANKSGIVING DAY. HIGH TEMPERATURES
ARE EXPECTED TO QUICKLY REBOUND INTO THE LOW 60S. SOUTH WINDS WILL
BE STRONG AND GUSTY ON THANKSGIVING DAY WITH A STRONG PRESSURE
GRADIENT BETWEEN A SURFACE HIGH OVER THE SOUTHEASTERN U.S. AND
SURFACE LOW FORMING ALONG THE ROCKY MOUNTAINS. MODELS ARE INDICATING
A LONGWAVE TROUGH WILL MOVE OUT OF THE ROCKY MOUNTAINS ON FRIDAY
ALONG WITH THE SURFACE LOW AND COLD FRONT. ENOUGH ELEVATED
INSTABILITY WILL EXIST AHEAD OF THE APPROACHING FRONT FOR A FEW
THUNDERSTORMS DURING THE DAY ON FRIDAY.
MODELS QUICKLY DIVERGE INTO NEXT WEEKEND. THE OPERATIONAL GFS AND
DGEX BRING THE COLD FRONT THROUGH THE CWA FRIDAY NIGHT AND THEN
CLOSE OFF AN UPPER LEVEL LOW OVER THE MID-MISSISSIPPI RIVER VALLEY.
THE 12Z ECMWF BRINGS THE FRONT THROUGH THE CWA SATURDAY MORNING BUT
THEN CLOSES THE UPPER LEVEL LOW OFF IN NORTHEASTERN OKLAHOMA. THE
ECMWF SOLUTION WOULD KEEP PRECIPITATION CHANCES IN THE FORECAST FOR
THE MAJORITY OF HOLIDAY WEEKEND. FOR THE FORECAST HAVE FAVORED THE
MORE PROGRESSIVE SOLUTIONS OF THE GFS AND DGEX WITH MANY OF THE GFS
ENSEMBLES INDICATING A MORE PROGRESSIVE UPPER LEVEL WAVE.
ANDERSON
&&
.AVIATION...
THINK VFR CIGS WILL PERSIST THROUGH THE AFTERNOON. THE MODELS WANT
TO LIFT THE LOW LEVEL MOISTURE ACROSS SOUTHERN MO AND SOUTHEASTERN
KS UP ACROSS TOP AND FOE OVERNIGHT AS SEEN IN THE ISENTROPIC
SURFACES AND 925MB RH PROGS. WITH THE NAM APPEARING TO HAVE A BETTER
GRASP OF CURRENT CONDITIONS...USED IT FOR TIMING MVFR CIGS RETURN
THIS EVENING. RIGHT NOW IT LOOKS LIKE MHK MAY STAY JUST TO THE WEST
OF THE LOW LEVEL MOISTURE.
WOLTERS
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1055 AM MST SUN NOV 20 2011
.UPDATE...
949 AM MST SUN NOV 20 2011
HIGH TEMPERATURES TRICKY TO NAIL DOWN TODAY DUE TO THE CLOUD
COVER. DESPITE MOST OF THE MODEL GUIDANCE TRENDING TOWARDS
TEMPERATURES IN THE UPPER 30S AND LOW 40S...AM CONCERNED THEY ARE
NOT GRASPING THE CLOUD DECK IN PLACE. THE CLOUDS LOOK TO
DISSIPATE DURING THE AFTERNOON...JUST A MATTER OF IF THEY WILL
DISSIPATE BEFORE PEAK HEATING OR NOT. TO FURTHER COMPLICATE
MATTERS WINDS ACROSS THE AREA RANGE FROM THE SOUTH TO
NORTHEAST...AND WILL BECOME ENTIRELY SOUTHERLY BY MID AFTERNOON
WHICH SHOULD HELP WARM THINGS UP MAINLY IN THE WESTERN AREAS AS
THE CLOUD COVER DISSIPATES. CLOUD COVER SHOULD DISSIPATE FROM WEST
TO EAST ACROSS THE CWA DURING THE AFTERNOON. DID COOL TEMPERATURES
A FEW DEGREES AS THE RUC IS SHOWING THE CLOUDS HANGING THROUGH
MOST OF THE PEAK HEATING.
JTL
&&
.DISCUSSION...
200 AM MST SUN NOV 20 2011
TODAY-TUESDAY NIGHT...SFC HIGH OVER THE NORTHERN AND CENTRAL PLAINS
WILL MOVE AWAY FROM THE AREA MONDAY AS AN OPEN UPPER LEVEL WAVE
MOVES ACROSS THE AREA MONDAY NIGHT. FOR TUESDAY-TUESDAY NIGHT
UPPER RIDGE BUILDS OVER THE AREA.
WILL CONTINUE LOW POPS ACROSS THE SOUTH AND SOUTHEAST MONDAY NIGHT.
TEMPERATURES TODAY IN THE UPPER 30S TO LOW 40S WITH LOW 50S MONDAY
AND MID 50S TUESDAY. OVERNIGHT LOWS GENERALLY IN THE 20S EXCEPT
NEAR 30 TUESDAY NIGHT.
007
FOR THE PERIOD WEDNESDAY THROUGH SATURDAY...SHORTWAVE RIDGING EARLY
IN THE PERIOD WILL TRANSITION TO SOUTHWEST FLOW AHEAD OF THE NEXT
SYSTEM APPROACHING FROM THE DESERT SOUTHWEST. DRY CONDITIONS AND
ABOVE NORMAL TEMPERATURES WILL RESULT FOR WEDNESDAY THROUGH FRIDAY.
AFOREMENTIONED SYSTEM WILL TRACK ACROSS THE SOUTHERN PLAINS ON
FRIDAY AND APPEARS PRECIPITATION WILL ONCE AGAIN MISS THE LOCAL AREA
AS DRY WESTERLY DOWNSLOPING WINDS DOMINATE THE FORECAST PROFILES.
NONETHELESS MORE SEASONABLY COOL TEMPERATURES WILL FOLLOW FOR
SATURDAY. 024
&&
.AVIATION...
1040 AM MST SUN NOV 20 2011
VFR CONDITIONS WILL PREVAIL FOR THE 18Z TAFS. LOW CLOUDS AT KGLD
HAVE MOVED OUT FASTER THAN ANTICIPATED SO KEPT OUT ANY MENTION OF
LOW CLOUDS FOR THE LATEST TAF. THERE COULD BE A SHORT TIME PERIOD
OF SCATTERED MID CLOUDS OVERNIGHT BEFORE THE DECK BECOMES BROKEN
AGAIN...AS MOISTURE AHEAD OF THE NEXT TROUGH CURRENTLY OVER THE WEST
COAST MOVES IN. CURRENTLY KMCK HAS SCATTERED MVFR CEILINGS. SINCE
THE MID CLOUDS ARE NOT AS THICK THERE...AM THINKING THE ADDED
MIXING SHOULD PREVENT A BROKEN MVFR DECK. MOST GUIDANCE HAS THE
DECK REMAINING SCATTERED AT BEST. OVERNIGHT THE VIS MAY BECOME
REDUCED FOR KMCK AND KGLD AS WINDS WILL BE LIGHT AND DEW POINT
DEPRESSIONS WILL BE SMALL. HOWEVER CURRENT POINT SOUNDINGS ARE ONLY
SATURATED AT GROUND LEVEL...SO WILL LEAVE OUT A MENTION OF REDUCED
VIS AT THIS TIME.
JTL
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1121 AM CST SUN NOV 20 2011
.DISCUSSION...
.AVIATION...
FOR THE 18Z TAF ISSUANCE...CLOUDS ARE EXPECTED TO GRADUALLY
DECREASE FROM SOUTHWEST TO NORTHEAST THIS AFTERNOON AS AN UPPER
LEVEL DISTURBANCE EXITS NEW MEXICO AND CROSSES SOUTHWESTERN KANSAS
AND WESTERN OKLAHOMA. THE LOW IFR/MVFR CIGS CURRENTLY PERSISTING
ACROSS SOUTH CENTRAL AND PARTS OF SOUTHWEST KANSAS WILL CONTINUE
FOR THE NEXT SEVERAL HOURS BEFORE GIVING WAY TO VFR CONDITIONS.
SURFACE WINDS WILL BECOME LIGHT BY EARLY TONIGHT AND THEN
GRADUALLY SHIFT TO THE SOUTHEAST BY EARLY MONDAY MORNING AS A
SURFACE RIDGE OF HIGH PRESSURE BUILDS INTO CENTRAL/EASTERN KANSAS. -RB
&&
PREV DISCUSSION... /ISSUED 228 AM CST SUN NOV 20 2011/
SYNOPSIS...
WATER VAPOR LOOP AND RUC ANALYSIS AS OF 20/07Z SHOWED AN EXITING
UPPER TROPOSPHERIC JET STREAK CENTERED FROM SOUTH DAKOTA THROUGH
NORTHERN WISCONSIN. A SUBTROPICAL JET EXTENDED FROM CENTRAL BAJA
CALIFORNIA NORTHEAST INTO WEST TEXAS...WHICH WAS RESPONSIBLE FOR A
LARGE AREA OF CIRRIFORM CLOUD COVER OVER MUCH OF THE CENTRAL PLAINS
SOUTHWEST INTO WEST TEXAS. FARTHER WEST...AN UPPER LOW CONTINUED TO
DIG SOUTH JUST OFF THE COAST OF NORTHERN CALIFORNIA. AT THE
SURFACE...THE STRONG COLD FRONT WHICH PROVIDED KANSAS WITH THE
COLDEST AIRMASS OF THE YOUNG COLD SEASON WAS MOVING INTO NORTHWEST
TEXAS...AND EXTENDED NORTHEAST INTO NORTHWEST ARKANSAS. THE CENTER
OF THE ARCTIC HIGH WAS STILL POSITIONED OVER THE NORTHERN PLAINS
WHERE TEMPERATURES IN THE CORE OF THE ARCTIC AIRMASS IN THE WESTERN
DAKOTAS AND EASTERN MONTANA WERE ANYWHERE FROM 0F TO -10F. A
COMPARISON OF THE 06Z OBS WITH THE 6-HR FORECAST FROM THE NAM12
SHOWS A WIDESPREAD 4 TO 7 DEGREE WARM BIAS IN THE MODEL 2M
TEMPERATURES IN THE ARCTIC AIRMASS FROM CENTRAL NEBRASKA INTO THE
DAKOTAS. AHEAD OF THE FRONT IN TEXAS...ANOMALOUS MOISTURE RETURN WAS
UNDERWAY WITH 70F DEWPOINTS REACHING AS FAR NORTH AS A WACO TO
TYLER, TEXAS LINE. -UMSCHEID
DISCUSSION...
DAYS 1-2 /TODAY THROUGH MONDAY NIGHT/...
TODAY:
INHERITED FORECAST HIGHS (UPPER 30S NORTHEAST HALF TO THE LOWER 40S
SOUTHWEST) FOR TODAY LOOK PRETTY GOOD AND SEE NO REASON TO ADJUST AS
THEY ARE ALREADY A FEW DEGREES COLDER THAN THE GUIDANCE AND GRIDDED
2M TEMPS. WINDS SHOULD BE RATHER LIGHT AS THE SURFACE RIDGE AXIS
MOVES ACROSS KANSAS TODAY. WINDS WILL EVENTUALLY SHIFT TO THE EAST
BY LATE IN THE DAY WITH THE RIDGE AXIS WEAKENING AND MOVING TO THE
EAST. THE NAM12 STILL SHOWS A SIGNAL OF DEVELOPING A NARROW BAND OF
STRATUS AND EVEN PERHAPS SOME LIGHT FREEZING DRIZZLE WITHIN THE BAND
OF DEFORMATION/THERMAL GRADIENT IN THE 850-800MB LAYER OVER THE
SOUTHEASTERN ZONES. WILL KEEP A MENTION OF PATCHY FREEZING
DRIZZLE...BUT CONFINE IT TO THE FAR SOUTHEAST...MAINLY COMANCHE AND
BARBER COUNTIES.
TONIGHT:
THE UPPER LOW OFF THE COAST OF CALIFORNIA WILL HAVE MOVED SOUTHEAST
TO CALIFORNIA/BAJA CALIFORNIA BORDER AREA BY LATE TONIGHT. WILL
START TO SEE A RESPONSE ACROSS WEST AND SOUTHWEST TEXAS WITH
INCREASING WINDS OFF THE SURFACE AND LOW LEVEL MOISTURE (+10 TO +12C
850MB DEWPOINT) MAKING A RUN ON THE TEXAS PANHANDLE BY THE END OF
THIS PERIOD. A WEAK SURFACE LOW WILL DEVELOP ALONG THE STALLED OUT
FRONT OVER SOUTHEASTERN NEW MEXICO AND ADJACENT SOUTHWEST TEXAS WITH
STRONG 850MB FLOW ABOVE THE SHALLOW COLD AIRMASS RESULTING IN
STRATUS DEVELOPMENT INTO THE TEXAS PANHANDLE BY 12Z MONDAY. DESPITE
THE WEAK WINDS AT THE SURFACE...LOWS SHOULD NOT GET MUCH BELOW
22-25F RANGE WITH SOME HIGH CLOUD COVER TIED TO THE SOUTHERN BRANCH
JET LINGERING AROUND WESTERN KANSAS.
MONDAY:
A FAIRLY ROBUST POTENTIAL VORTICITY ANOMALY WILL BE ROUNDING THE
BASE OF THE TROUGH AND EJECT NORTHEASTWARD OUT INTO EASTERN NEW
MEXICO AND WEST TEXAS. THIS IS USUALLY A FAVORABLE TRACK FOR HEAVY
PRECIPITATION ACROSS PORTIONS OF THE DDC FA. WARM FRONTOGENESIS
WILL INCREASE ACROSS THE TEXAS PANHANDLE WITH SHOWERS AND
THUNDERSTORMS BLOSSOMING BY EARLY AFTERNOON. THE RAIN AND
THUNDERSTORM ACTIVITY WILL LIFT NORTHEAST DURING THE AFTERNOON HOURS
AND IMPINGE OF THE SOUTHERN/SOUTHEASTER DDC FA BY THE END OF THIS
PERIOD. TEMPERATURES ARE EXPECTED TO WARM INTO THE UPPER 30S TO
LOWER 40S IN THE SOUTHEASTERN PORTION OF THE FORECAST AREA SO AM
EXPECTING PRECIPITATION TYPE TO BE ALL RAIN. POPS WILL BE 30 TO 40
PERCENT IN THE FAR SOUTHEAST DDC FA WITH 20 POPS OVER THE REST OF
THE SOUTHERN THROUGH EAST-CENTRAL ZONES.
MONDAY NIGHT:
TYPICALLY...THE TRACK OF SUCH A FORMIDABLE AND COMPACT STORM SYSTEM
FROM EASTERN NEW MEXICO TO NORTHWEST OKLAHOMA IS FAVORABLE FOR HEAVY
PRECIPITATION ACROSS AT LEAST A PORTION OF THE DDC FORECAST AREA.
THERE WILL BE TWO PROBLEMS THAT WILL MITIGATE HEAVY PRECIPITATION
POTENTIAL FOR A LARGER AREA OF SOUTHWEST KANSAS. 1) 700-500MB MEAN
FLOW FROM ABOUT 230 DEGREES MEANS THAT HEAVY RAIN AND THUNDERSTORM
ACTIVITY THAT FORMS IN THE WARM/MOIST CONVEYOR OVER THE TX PANHANDLE
WILL THEN MOVE INTO FAR NORTHEASTERN TEXAS PANHANDLE/NORTHWEST
OKLAHOMA...THEN INTO SOUTH-CENTRAL KANSAS...CLIPPING THE DDC
FORECAST AREA. 2) LATE DEVELOPMENT OF THE 700MB LOW. MODELS SHOW
THE 700MB LOW DEVELOPING AND MATURING EARLY TUESDAY MORNING OVER
SOUTH CENTRAL KANSAS...SUCH THAT ONCE A "WRAP AROUND" COLD CONVEYOR
CAN DEVELOP AND BECOME ESTABLISHED...IT WILL DO SO JUST EAST OF THE
DDC FA. FOR THESE REASONS...AREAS ALONG AND NORTHWEST OF A LIBERAL
TO DODGE CITY TO LARNED LINE STAND TO SEE A VERY LOW POTENTIAL FOR
BENEFICIAL PRECIPITATION (LESS THAN A TENTH OF AN INCH). FAR
SOUTHEAST DDC FA (I.E. KIOWA IN BARBER COUNTY) COULD SEE OVER
THREE-QUARTERS OF AN INCH BY EARLY TUESDAY MORNING. -UMSCHEID
DAYS 3-7 /TUESDAY THROUGH SATURDAY NIGHT/...
THE PERIOD WILL BEGIN WITH INCREASING UPPER LEVEL RIDGING AND
ISENTROPIC DOWNGLIDE DEVELOPING. NORTHWEST SURFACE WINDS WILL
PROBABLY BE ON THE BREEZY SIDE TUESDAY AS SURFACE PRESSURE INCREASES
ACROSS WESTERN KANSAS AS A LARGE SURFACE ANTICYCLONE SHIFTS EASTWARD
FROM SOUTHEAST KANSAS THROUGH THE MID MISSISSIPPI VALLEY. THESE WINDS
WILL DIMINISH TO LIGHT THROUGH TUESDAY NIGHT AND EARLY WEDNESDAY,
BACKING TO THE SOUTHWEST AGAIN AND BECOMING LIGHT SOUTHWEST THROUGH
THE DAY ON WEDNESDAY. THIS TRANSITION SHOULD SUPPORT WARMING
TEMPERATURES FROM THE 50S ON TUESDAY BACK UP TO AROUND 60 OR MORE ON
WEDNESDAY WITH SOUTHERLY FLOW AND WARM AIR ADVECTION/DOWNSLOPE.
THE UPPER PATTERN WILL REMAIN IN A PROGRESSIVE TROUGH - RIDGE -
TROUGH PATTERN THROUGH THE WEEK. FROM WEDNESDAY NIGHT INTO EARLY
FRIDAY, THE MODELS SWING ANOTHER UPPER JET SEGMENT FROM THE SOUTHERN
ROCKIES INTO THE CENTRAL PLAINS. AS A RESULT, ANOTHER DECENT SURFACE
TROUGH WILL DEVELOP OVER THE CENTRAL HIGH PLAINS ON THURSDAY WHICH
WILL PRODUCE BREEZY TO WINDY SOUTHWEST WINDS AGAIN, BETTER MIXING
AND EVEN WARMER TEMPERATURES INTO THE 60S. AS THE UPPER PATTERN
CONTINUES TO EVOLVE INTO A SHARPER TROUGH OVER THE CENTRAL PLAINS,
ANOTHER STRONG COLD FRONT WILL SWEEP INTO THE HIGH PLAINS FROM
MONTANA AND WYOMING, BRINGING STRONG NORTHWEST WINDS AND COLD
ADVECTION FRIDAY OR FRIDAY NIGHT FOLLOWED BY A COOLING TREND INTO
SUNDAY. -RUSSELL
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 39 23 47 33 / 0 0 20 30
GCK 40 22 47 32 / 0 0 10 20
EHA 46 29 50 35 / 0 0 10 20
LBL 44 26 50 34 / 0 0 10 30
HYS 39 20 47 32 / 0 0 10 20
P28 40 26 48 37 / 10 0 40 80
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1002 AM MST SUN NOV 20 2011
.UPDATE...
949 AM MST SUN NOV 20 2011
HIGH TEMPERATURES TRICKY TO NAIL DOWN TODAY DUE TO THE CLOUD
COVER. DESPITE MOST OF THE MODEL GUIDANCE TRENDING TOWARDS
TEMPERATURES IN THE UPPER 30S AND LOW 40S...AM CONCERNED THEY ARE
NOT GRASPING THE CLOUD DECK IN PLACE. THE CLOUDS LOOK TO
DISSIPATE DURING THE AFTERNOON...JUST A MATTER OF IF THEY WILL
DISSIPATE BEFORE PEAK HEATING OR NOT. TO FURTHER COMPLICATE
MATTERS WINDS ACROSS THE AREA RANGE FROM THE SOUTH TO
NORTHEAST...AND WILL BECOME ENTIRELY SOUTHERLY BY MID AFTERNOON
WHICH SHOULD HELP WARM THINGS UP MAINLY IN THE WESTERN AREAS AS
THE CLOUD COVER DISSIPATES. CLOUD COVER SHOULD DISSIPATE FROM WEST
TO EAST ACROSS THE CWA DURING THE AFTERNOON. DID COOL TEMPERATURES
A FEW DEGREES AS THE RUC IS SHOWING THE CLOUDS HANGING THROUGH
MOST OF THE PEAK HEATING.
JTL
&&
.DISCUSSION...
200 AM MST SUN NOV 20 2011
TODAY-TUESDAY NIGHT...SFC HIGH OVER THE NORTHERN AND CENTRAL PLAINS
WILL MOVE AWAY FROM THE AREA MONDAY AS AN OPEN UPPER LEVEL WAVE
MOVES ACROSS THE AREA MONDAY NIGHT. FOR TUESDAY-TUESDAY NIGHT
UPPER RIDGE BUILDS OVER THE AREA.
WILL CONTINUE LOW POPS ACROSS THE SOUTH AND SOUTHEAST MONDAY NIGHT.
TEMPERATURES TODAY IN THE UPPER 30S TO LOW 40S WITH LOW 50S MONDAY
AND MID 50S TUESDAY. OVERNIGHT LOWS GENERALLY IN THE 20S EXCEPT
NEAR 30 TUESDAY NIGHT.
007
FOR THE PERIOD WEDNESDAY THROUGH SATURDAY...SHORTWAVE RIDGING EARLY
IN THE PERIOD WILL TRANSITION TO SOUTHWEST FLOW AHEAD OF THE NEXT
SYSTEM APPROACHING FROM THE DESERT SOUTHWEST. DRY CONDITIONS AND
ABOVE NORMAL TEMPERATURES WILL RESULT FOR WEDNESDAY THROUGH FRIDAY.
AFOREMENTIONED SYSTEM WILL TRACK ACROSS THE SOUTHERN PLAINS ON
FRIDAY AND APPEARS PRECIPITATION WILL ONCE AGAIN MISS THE LOCAL AREA
AS DRY WESTERLY DOWNSLOPING WINDS DOMINATE THE FORECAST PROFILES.
NONETHELESS MORE SEASONABLY COOL TEMPERATURES WILL FOLLOW FOR
SATURDAY. 024
&&
.AVIATION...
426 AM MST SUN NOV 20 2011
FOR THE 12Z TAFS...AREAS OF FOG LINGER JUST TO THE WEST OF KGLD BUT
SO FAR HAVE NOT SHOWN ANY SIGNS OF MOVING INTO THE TERMINAL AREA.
HIGH CLOUDS HAVE PREVENTED RADIATIONAL COOLING AND BELIEVE WILL
ESCAPE WITH VFR CONDITIONS THIS MORNING AT BOTH KGLD AND KMCK.
SURFACE WINDS WILL BE LIGHT...MAINLY FROM THE SOUTH TO
SOUTHEAST...WITH HIGH PRESSURE NOSING IN FROM THE NORTHERN PLAINS.
024
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
539 AM CST SUN NOV 20 2011
.UPDATE...
.AVIATION /FOR THE 12Z TAF ISSUANCE/
LOW LIFR/IFR STRATUS WILL BE A FORECAST CHALLENGE OVER THE NEXT
SEVERAL HOURS. A CORRIDOR OF IFR STRATUS HAS FORMED ACROSS CENTRAL
KANSAS EXTENDING THROUGH HYS AND DDC. GIVEN THE VERY WEAK UPSLOPE
SURFACE WIND COMPONENT AND EASTERLY FLOW IN THE LOWEST
GATES ON THE HAVILAND, KS PROFILER, WE ARE PESSIMISTIC THAT THIS
STRATUS WILL VERY QUICKLY DISSIPATE THIS MORNING. AT THIS TIME, WE
WILL CARRY PREVAILING IFR STRATUS IN THE TERMINALS THROUGH AT LEAST
16 UTC BEFORE ALLOWING ANY IMPROVEMENT TO CEILINGS. SURFACE WINDS
WILL REMAIN LIGHT AND VEERING WITH TIME THROUGH THE DAY IN RESPONSE
TO THE EASTWARD DRIFTING NORTHERN PLAINS ANTICYCLONE. - RUSSELL
&&
.PREV DISCUSSION... /ISSUED 228 AM CST SUN NOV 20 2011/
SYNOPSIS...
WATER VAPOR LOOP AND RUC ANALYSIS AS OF 20/07Z SHOWED AN EXITING
UPPER TROPOSPHERIC JET STREAK CENTERED FROM SOUTH DAKOTA THROUGH
NORTHERN WISCONSIN. A SUBTROPICAL JET EXTENDED FROM CENTRAL BAJA
CALIFORNIA NORTHEAST INTO WEST TEXAS...WHICH WAS RESPONSIBLE FOR A
LARGE AREA OF CIRRIFORM CLOUD COVER OVER MUCH OF THE CENTRAL PLAINS
SOUTHWEST INTO WEST TEXAS. FARTHER WEST...AN UPPER LOW CONTINUED TO
DIG SOUTH JUST OFF THE COAST OF NORTHERN CALIFORNIA. AT THE
SURFACE...THE STRONG COLD FRONT WHICH PROVIDED KANSAS WITH THE
COLDEST AIRMASS OF THE YOUNG COLD SEASON WAS MOVING INTO NORTHWEST
TEXAS...AND EXTENDED NORTHEAST INTO NORTHWEST ARKANSAS. THE CENTER
OF THE ARCTIC HIGH WAS STILL POSITIONED OVER THE NORTHERN PLAINS
WHERE TEMPERATURES IN THE CORE OF THE ARCTIC AIRMASS IN THE WESTERN
DAKOTAS AND EASTERN MONTANA WERE ANYWHERE FROM 0F TO -10F. A
COMPARISON OF THE 06Z OBS WITH THE 6-HR FORECAST FROM THE NAM12
SHOWS A WIDESPREAD 4 TO 7 DEGREE WARM BIAS IN THE MODEL 2M
TEMPERATURES IN THE ARCTIC AIRMASS FROM CENTRAL NEBRASKA INTO THE
DAKOTAS. AHEAD OF THE FRONT IN TEXAS...ANOMALOUS MOISTURE RETURN WAS
UNDERWAY WITH 70F DEWPOINTS REACHING AS FAR NORTH AS A WACO TO
TYLER, TEXAS LINE. -UMSCHEID
DISCUSSION...
DAYS 1-2 /TODAY THROUGH MONDAY NIGHT/...
TODAY:
INHERITED FORECAST HIGHS (UPPER 30S NORTHEAST HALF TO THE LOWER 40S
SOUTHWEST) FOR TODAY LOOK PRETTY GOOD AND SEE NO REASON TO ADJUST AS
THEY ARE ALREADY A FEW DEGREES COLDER THAN THE GUIDANCE AND GRIDDED
2M TEMPS. WINDS SHOULD BE RATHER LIGHT AS THE SURFACE RIDGE AXIS
MOVES ACROSS KANSAS TODAY. WINDS WILL EVENTUALLY SHIFT TO THE EAST
BY LATE IN THE DAY WITH THE RIDGE AXIS WEAKENING AND MOVING TO THE
EAST. THE NAM12 STILL SHOWS A SIGNAL OF DEVELOPING A NARROW BAND OF
STRATUS AND EVEN PERHAPS SOME LIGHT FREEZING DRIZZLE WITHIN THE BAND
OF DEFORMATION/THERMAL GRADIENT IN THE 850-800MB LAYER OVER THE
SOUTHEASTERN ZONES. WILL KEEP A MENTION OF PATCHY FREEZING
DRIZZLE...BUT CONFINE IT TO THE FAR SOUTHEAST...MAINLY COMANCHE AND
BARBER COUNTIES.
TONIGHT:
THE UPPER LOW OFF THE COAST OF CALIFORNIA WILL HAVE MOVED SOUTHEAST
TO CALIFORNIA/BAJA CALIFORNIA BORDER AREA BY LATE TONIGHT. WILL
START TO SEE A RESPONSE ACROSS WEST AND SOUTHWEST TEXAS WITH
INCREASING WINDS OFF THE SURFACE AND LOW LEVEL MOISTURE (+10 TO +12C
850MB DEWPOINT) MAKING A RUN ON THE TEXAS PANHANDLE BY THE END OF
THIS PERIOD. A WEAK SURFACE LOW WILL DEVELOP ALONG THE STALLED OUT
FRONT OVER SOUTHEASTERN NEW MEXICO AND ADJACENT SOUTHWEST TEXAS WITH
STRONG 850MB FLOW ABOVE THE SHALLOW COLD AIRMASS RESULTING IN
STRATUS DEVELOPMENT INTO THE TEXAS PANHANDLE BY 12Z MONDAY. DESPITE
THE WEAK WINDS AT THE SURFACE...LOWS SHOULD NOT GET MUCH BELOW
22-25F RANGE WITH SOME HIGH CLOUD COVER TIED TO THE SOUTHERN BRANCH
JET LINGERING AROUND WESTERN KANSAS.
MONDAY:
A FAIRLY ROBUST POTENTIAL VORTICITY ANOMALY WILL BE ROUNDING THE
BASE OF THE TROUGH AND EJECT NORTHEASTWARD OUT INTO EASTERN NEW
MEXICO AND WEST TEXAS. THIS IS USUALLY A FAVORABLE TRACK FOR HEAVY
PRECIPITATION ACROSS PORTIONS OF THE DDC FA. WARM FRONTOGENESIS
WILL INCREASE ACROSS THE TEXAS PANHANDLE WITH SHOWERS AND
THUNDERSTORMS BLOSSOMING BY EARLY AFTERNOON. THE RAIN AND
THUNDERSTORM ACTIVITY WILL LIFT NORTHEAST DURING THE AFTERNOON HOURS
AND IMPINGE OF THE SOUTHERN/SOUTHEASTER DDC FA BY THE END OF THIS
PERIOD. TEMPERATURES ARE EXPECTED TO WARM INTO THE UPPER 30S TO
LOWER 40S IN THE SOUTHEASTERN PORTION OF THE FORECAST AREA SO AM
EXPECTING PRECIPITATION TYPE TO BE ALL RAIN. POPS WILL BE 30 TO 40
PERCENT IN THE FAR SOUTHEAST DDC FA WITH 20 POPS OVER THE REST OF
THE SOUTHERN THROUGH EAST-CENTRAL ZONES.
MONDAY NIGHT:
TYPICALLY...THE TRACK OF SUCH A FORMIDABLE AND COMPACT STORM SYSTEM
FROM EASTERN NEW MEXICO TO NORTHWEST OKLAHOMA IS FAVORABLE FOR HEAVY
PRECIPITATION ACROSS AT LEAST A PORTION OF THE DDC FORECAST AREA.
THERE WILL BE TWO PROBLEMS THAT WILL MITIGATE HEAVY PRECIPITATION
POTENTIAL FOR A LARGER AREA OF SOUTHWEST KANSAS. 1) 700-500MB MEAN
FLOW FROM ABOUT 230 DEGREES MEANS THAT HEAVY RAIN AND THUNDERSTORM
ACTIVITY THAT FORMS IN THE WARM/MOIST CONVEYOR OVER THE TX PANHANDLE
WILL THEN MOVE INTO FAR NORTHEASTERN TEXAS PANHANDLE/NORTHWEST
OKLAHOMA...THEN INTO SOUTH-CENTRAL KANSAS...CLIPPING THE DDC
FORECAST AREA. 2) LATE DEVELOPMENT OF THE 700MB LOW. MODELS SHOW
THE 700MB LOW DEVELOPING AND MATURING EARLY TUESDAY MORNING OVER
SOUTH CENTRAL KANSAS...SUCH THAT ONCE A "WRAP AROUND" COLD CONVEYOR
CAN DEVELOP AND BECOME ESTABLISHED...IT WILL DO SO JUST EAST OF THE
DDC FA. FOR THESE REASONS...AREAS ALONG AND NORTHWEST OF A LIBERAL
TO DODGE CITY TO LARNED LINE STAND TO SEE A VERY LOW POTENTIAL FOR
BENEFICIAL PRECIPITATION (LESS THAN A TENTH OF AN INCH). FAR
SOUTHEAST DDC FA (I.E. KIOWA IN BARBER COUNTY) COULD SEE OVER
THREE-QUARTERS OF AN INCH BY EARLY TUESDAY MORNING. -UMSCHEID
DAYS 3-7 /TUESDAY THROUGH SATURDAY NIGHT/...
THE PERIOD WILL BEGIN WITH INCREASING UPPER LEVEL RIDGING AND
ISENTROPIC DOWNGLIDE DEVELOPING. NORTHWEST SURFACE WINDS WILL
PROBABLY BE ON THE BREEZY SIDE TUESDAY AS SURFACE PRESSURE INCREASES
ACROSS WESTERN KANSAS AS A LARGE SURFACE ANTICYCLONE SHIFTS EASTWARD
FROM SOUTHEAST KANSAS THROUGH THE MID MISSISSIPPI VALLEY. THESE WINDS
WILL DIMINISH TO LIGHT THROUGH TUESDAY NIGHT AND EARLY WEDNESDAY,
BACKING TO THE SOUTHWEST AGAIN AND BECOMING LIGHT SOUTHWEST THROUGH
THE DAY ON WEDNESDAY. THIS TRANSITION SHOULD SUPPORT WARMING
TEMPERATURES FROM THE 50S ON TUESDAY BACK UP TO AROUND 60 OR MORE ON
WEDNESDAY WITH SOUTHERLY FLOW AND WARM AIR ADVECTION/DOWNSLOPE.
THE UPPER PATTERN WILL REMAIN IN A PROGRESSIVE TROUGH - RIDGE -
TROUGH PATTERN THROUGH THE WEEK. FROM WEDNESDAY NIGHT INTO EARLY
FRIDAY, THE MODELS SWING ANOTHER UPPER JET SEGMENT FROM THE SOUTHERN
ROCKIES INTO THE CENTRAL PLAINS. AS A RESULT, ANOTHER DECENT SURFACE
TROUGH WILL DEVELOP OVER THE CENTRAL HIGH PLAINS ON THURSDAY WHICH
WILL PRODUCE BREEZY TO WINDY SOUTHWEST WINDS AGAIN, BETTER MIXING
AND EVEN WARMER TEMPERATURES INTO THE 60S. AS THE UPPER PATTERN
CONTINUES TO EVOLVE INTO A SHARPER TROUGH OVER THE CENTRAL PLAINS,
ANOTHER STRONG COLD FRONT WILL SWEEP INTO THE HIGH PLAINS FROM
MONTANA AND WYOMING, BRINGING STRONG NORTHWEST WINDS AND COLD
ADVECTION FRIDAY OR FRIDAY NIGHT FOLLOWED BY A COOLING TREND INTO
SUNDAY. -RUSSELL
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 39 23 47 33 / 0 0 20 30
GCK 40 22 47 32 / 0 0 10 20
EHA 46 29 50 35 / 0 0 10 20
LBL 44 26 50 34 / 0 0 10 30
HYS 39 20 47 32 / 0 0 10 20
P28 40 26 48 37 / 10 0 40 80
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FN99/99/99
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
228 AM CST SUN NOV 20 2011
.SYNOPSIS...
WATER VAPOR LOOP AND RUC ANALYSIS AS OF 20/07Z SHOWED AN EXITING
UPPER TROPOSPHERIC JET STREAK CENTERED FROM SOUTH DAKOTA THROUGH
NORTHERN WISCONSIN. A SUBTROPICAL JET EXTENDED FROM CENTRAL BAJA
CALIFORNIA NORTHEAST INTO WEST TEXAS...WHICH WAS RESPONSIBLE FOR A
LARGE AREA OF CIRRIFORM CLOUD COVER OVER MUCH OF THE CENTRAL PLAINS
SOUTHWEST INTO WEST TEXAS. FARTHER WEST...AN UPPER LOW CONTINUED TO
DIG SOUTH JUST OFF THE COAST OF NORTHERN CALIFORNIA. AT THE
SURFACE...THE STRONG COLD FRONT WHICH PROVIDED KANSAS WITH THE
COLDEST AIRMASS OF THE YOUNG COLD SEASON WAS MOVING INTO NORTHWEST
TEXAS...AND EXTENDED NORTHEAST INTO NORTHWEST ARKANSAS. THE CENTER
OF THE ARCTIC HIGH WAS STILL POSITIONED OVER THE NORTHERN PLAINS
WHERE TEMPERATURES IN THE CORE OF THE ARCTIC AIRMASS IN THE WESTERN
DAKOTAS AND EASTERN MONTANA WERE ANYWHERE FROM 0F TO -10F. A
COMPARISON OF THE 06Z OBS WITH THE 6-HR FORECAST FROM THE NAM12
SHOWS A WIDESPREAD 4 TO 7 DEGREE WARM BIAS IN THE MODEL 2M
TEMPERATURES IN THE ARCTIC AIRMASS FROM CENTRAL NEBRASKA INTO THE
DAKOTAS. AHEAD OF THE FRONT IN TEXAS...ANOMALOUS MOISTURE RETURN WAS
UNDERWAY WITH 70F DEWPOINTS REACHING AS FAR NORTH AS A WACO TO
TYLER, TEXAS LINE. -UMSCHEID
&&
.DISCUSSION...
DAYS 1-2 /TODAY THROUGH MONDAY NIGHT/...
TODAY:
INHERITED FORECAST HIGHS (UPPER 30S NORTHEAST HALF TO THE LOWER 40S
SOUTHWEST) FOR TODAY LOOK PRETTY GOOD AND SEE NO REASON TO ADJUST AS
THEY ARE ALREADY A FEW DEGREES COLDER THAN THE GUIDANCE AND GRIDDED
2M TEMPS. WINDS SHOULD BE RATHER LIGHT AS THE SURFACE RIDGE AXIS
MOVES ACROSS KANSAS TODAY. WINDS WILL EVENTUALLY SHIFT TO THE EAST
BY LATE IN THE DAY WITH THE RIDGE AXIS WEAKENING AND MOVING TO THE
EAST. THE NAM12 STILL SHOWS A SIGNAL OF DEVELOPING A NARROW BAND OF
STRATUS AND EVEN PERHAPS SOME LIGHT FREEZING DRIZZLE WITHIN THE BAND
OF DEFORMATION/THERMAL GRADIENT IN THE 850-800MB LAYER OVER THE
SOUTHEASTERN ZONES. WILL KEEP A MENTION OF PATCHY FREEZING
DRIZZLE...BUT CONFINE IT TO THE FAR SOUTHEAST...MAINLY COMANCHE AND
BARBER COUNTIES.
TONIGHT:
THE UPPER LOW OFF THE COAST OF CALIFORNIA WILL HAVE MOVED SOUTHEAST
TO CALIFORNIA/BAJA CALIFORNIA BORDER AREA BY LATE TONIGHT. WILL
START TO SEE A RESPONSE ACROSS WEST AND SOUTHWEST TEXAS WITH
INCREASING WINDS OFF THE SURFACE AND LOW LEVEL MOISTURE (+10 TO +12C
850MB DEWPOINT) MAKING A RUN ON THE TEXAS PANHANDLE BY THE END OF
THIS PERIOD. A WEAK SURFACE LOW WILL DEVELOP ALONG THE STALLED OUT
FRONT OVER SOUTHEASTERN NEW MEXICO AND ADJACENT SOUTHWEST TEXAS WITH
STRONG 850MB FLOW ABOVE THE SHALLOW COLD AIRMASS RESULTING IN
STRATUS DEVELOPMENT INTO THE TEXAS PANHANDLE BY 12Z MONDAY. DESPITE
THE WEAK WINDS AT THE SURFACE...LOWS SHOULD NOT GET MUCH BELOW
22-25F RANGE WITH SOME HIGH CLOUD COVER TIED TO THE SOUTHERN BRANCH
JET LINGERING AROUND WESTERN KANSAS.
MONDAY:
A FAIRLY ROBUST POTENTIAL VORTICITY ANOMALY WILL BE ROUNDING THE
BASE OF THE TROUGH AND EJECT NORTHEASTWARD OUT INTO EASTERN NEW
MEXICO AND WEST TEXAS. THIS IS USUALLY A FAVORABLE TRACK FOR HEAVY
PRECIPITATION ACROSS PORTIONS OF THE DDC FA. WARM FRONTOGENESIS
WILL INCREASE ACROSS THE TEXAS PANHANDLE WITH SHOWERS AND
THUNDERSTORMS BLOSSOMING BY EARLY AFTERNOON. THE RAIN AND
THUNDERSTORM ACTIVITY WILL LIFT NORTHEAST DURING THE AFTERNOON HOURS
AND IMPINGE OF THE SOUTHERN/SOUTHEASTER DDC FA BY THE END OF THIS
PERIOD. TEMPERATURES ARE EXPECTED TO WARM INTO THE UPPER 30S TO
LOWER 40S IN THE SOUTHEASTERN PORTION OF THE FORECAST AREA SO AM
EXPECTING PRECIPITATION TYPE TO BE ALL RAIN. POPS WILL BE 30 TO 40
PERCENT IN THE FAR SOUTHEAST DDC FA WITH 20 POPS OVER THE REST OF
THE SOUTHERN THROUGH EAST-CENTRAL ZONES.
MONDAY NIGHT:
TYPICALLY...THE TRACK OF SUCH A FORMIDABLE AND COMPACT STORM SYSTEM
FROM EASTERN NEW MEXICO TO NORTHWEST OKLAHOMA IS FAVORABLE FOR HEAVY
PRECIPITATION ACROSS AT LEAST A PORTION OF THE DDC FORECAST AREA.
THERE WILL BE TWO PROBLEMS THAT WILL MITIGATE HEAVY PRECIPITATION
POTENTIAL FOR A LARGER AREA OF SOUTHWEST KANSAS. 1) 700-500MB MEAN
FLOW FROM ABOUT 230 DEGREES MEANS THAT HEAVY RAIN AND THUNDERSTORM
ACTIVITY THAT FORMS IN THE WARM/MOIST CONVEYOR OVER THE TX PANHANDLE
WILL THEN MOVE INTO FAR NORTHEASTERN TEXAS PANHANDLE/NORTHWEST
OKLAHOMA...THEN INTO SOUTH-CENTRAL KANSAS...CLIPPING THE DDC
FORECAST AREA. 2) LATE DEVELOPMENT OF THE 700MB LOW. MODELS SHOW
THE 700MB LOW DEVELOPING AND MATURING EARLY TUESDAY MORNING OVER
SOUTH CENTRAL KANSAS...SUCH THAT ONCE A "WRAP AROUND" COLD CONVEYOR
CAN DEVELOP AND BECOME ESTABLISHED...IT WILL DO SO JUST EAST OF THE
DDC FA. FOR THESE REASONS...AREAS ALONG AND NORTHWEST OF A LIBERAL
TO DODGE CITY TO LARNED LINE STAND TO SEE A VERY LOW POTENTIAL FOR
BENEFICIAL PRECIPITATION (LESS THAN A TENTH OF AN INCH). FAR
SOUTHEAST DDC FA (I.E. KIOWA IN BARBER COUNTY) COULD SEE OVER
THREE-QUARTERS OF AN INCH BY EARLY TUESDAY MORNING. -UMSCHEID
DAYS 3-7 /TUESDAY THROUGH SATURDAY NIGHT/...
THE PERIOD WILL BEGIN WITH INCREASING UPPER LEVEL RIDGING AND
ISENTROPIC DOWNGLIDE DEVELOPING. NORTHWEST SURFACE WINDS WILL
PROBABLY BE ON THE BREEZY SIDE TUESDAY AS SURFACE PRESSURE INCREASES
ACROSS WESTERN KANSAS AS A LARGE SURFACE ANTICYCLONE SHIFTS EASTWARD
FROM SOUTHEAST KANSAS THROUGH THE MID MISSISSIPPI VALLEY. THESE WINDS
WILL DIMINISH TO LIGHT THROUGH TUESDAY NIGHT AND EARLY WEDNESDAY,
BACKING TO THE SOUTHWEST AGAIN AND BECOMING LIGHT SOUTHWEST THROUGH
THE DAY ON WEDNESDAY. THIS TRANSITION SHOULD SUPPORT WARMING
TEMPERATURES FROM THE 50S ON TUESDAY BACK UP TO AROUND 60 OR MORE ON
WEDNESDAY WITH SOUTHERLY FLOW AND WARM AIR ADVECTION/DOWNSLOPE.
THE UPPER PATTERN WILL REMAIN IN A PROGRESSIVE TROUGH - RIDGE -
TROUGH PATTERN THROUGH THE WEEK. FROM WEDNESDAY NIGHT INTO EARLY
FRIDAY, THE MODELS SWING ANOTHER UPPER JET SEGMENT FROM THE SOUTHERN
ROCKIES INTO THE CENTRAL PLAINS. AS A RESULT, ANOTHER DECENT SURFACE
TROUGH WILL DEVELOP OVER THE CENTRAL HIGH PLAINS ON THURSDAY WHICH
WILL PRODUCE BREEZY TO WINDY SOUTHWEST WINDS AGAIN, BETTER MIXING
AND EVEN WARMER TEMPERATURES INTO THE 60S. AS THE UPPER PATTERN
CONTINUES TO EVOLVE INTO A SHARPER TROUGH OVER THE CENTRAL PLAINS,
ANOTHER STRONG COLD FRONT WILL SWEEP INTO THE HIGH PLAINS FROM
MONTANA AND WYOMING, BRINGING STRONG NORTHWEST WINDS AND COLD
ADVECTION FRIDAY OR FRIDAY NIGHT FOLLOWED BY A COOLING TREND INTO
SUNDAY. -RUSSELL
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 39 23 49 32 / 0 0 20 30
GCK 40 22 49 31 / 0 0 10 20
EHA 46 29 52 34 / 0 0 10 20
LBL 44 26 52 33 / 0 0 10 30
HYS 39 20 49 31 / 0 0 10 20
P28 40 26 50 36 / 10 0 40 80
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FN25/33
THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS...
/TODAY THROUGH TUESDAY/
AN AREA OF LOW PRESSURE IS CURRENTLY SKIRTING THE SAINT LAWRENCE
VALLEY...WITH A SURFACE COLD FRONT ALIGNED FROM MICHIGAN DOWN
THROUGH SOUTHERN ILLINOIS AND CENTRAL MISSOURI...WITH UNSEASONABLY
COLD HIGH PRESSURE WORKING INTO THE NORTHERN PLAINS.
MEANWHILE...UNSEASONABLY MILD OVERNIGHT READINGS ARE CURRENTLY BEING
ENJOYED IN EASTERN KENTUCKY...WITH MOST VALUES IN THE 50S AND 60S.
A GOOD LOW LEVEL JET IS IN PLACE ACROSS THE OHIO VALLEY...WITH
ISENTROPIC ASCENT AS WELL AS SOME UPPER LEVEL JET DYNAMICS SETTING
OFF SHOWERS ALONG THE OHIO RIVER.
THE MODELS ARE IN GOOD AGREEMENT WITH DROPPING THIS COLD FRONT
SOUTHEAST TOWARDS THE AREA TODAY. THE BEST FORCING AND MOISTURE
CONVERGENCE LOOKS TO BE NORTH OF THE MOUNTAIN PARKWAY AND NEAR THE
I-64 CORRIDOR...AND WILL CONTINUE TO ADVERTISE THE HIGHEST POPS FOR
THIS AREA. POPS WILL DROP OFF TO THE SOUTHEAST QUICKLY...PARTICULARLY
SOUTH OF THE HAL ROGERS PARKWAY AND HIGHWAY 80. THE BOUNDARY WILL
CONTINUE TO SAG SOUTH ACROSS THE AREA TONIGHT...WITH STEADY SHOWERS
GRADUALLY TAPERING OFF AFTER MIDNIGHT.
THERE WILL BE A LULL IN THE ACTIVITY MONDAY MORNING...BEFORE THE
NEXT WEAK SURFACE WAVE APPROACHES IN THE AFTERNOON FROM THE
SOUTHWEST. EXPECT SCATTERED TO NUMEROUS SHOWERS TO DEVELOP...WITH AN
ISOLATED THUNDERSTORM POSSIBLE. BY MONDAY NIGHT...A MORE STOUT AREA
OF LOW PRESSURE WILL BE RAMPING UP OUT OF THE ARKLATEX REGION AND
MOVE NORTHEAST...DRAGGING THE BOUNDARY BACK NORTH AS A WARM FRONT.
EXPECT ANOTHER ROUND OF HEALTHY SHOWERS WITH SOME EMBEDDED THUNDER
POSSIBLE. THIS WARM FRONT WILL LIFT THROUGH THE AREA TUESDAY
MORNING...WITH ANOTHER GOOD CHANCE OF A LULL IN THE ACTIVITY FOR
TUESDAY AFTERNOON.
AS FAR AS HEAVY RAINFALL GOES...THE MODELS HAVE GENERALLY BEEN
BACKING OFF THE TOTALS ACROSS EASTERN KENTUCKY. STILL...PWATS ARE
HIGH FOR THIS TIME OF YEAR AND THERE ARE SMALL WINDOWS OF INSTABILITY
THAT SUPPORT ISOLATED THUNDER...SO CAN NOT COMPLETELY RULE OUT A FEW
MINOR PROBLEMS OVER TIME...AND WILL CONTINUE TO HIGHLIGHT THIS IN THE
HWO.
FOR TEMPERATURES...GENERALLY USED A BLEND BETWEEN THE GUIDANCE AND THE
INHERITED NUMBERS. UNSEASONABLY MILD READINGS WILL DOMINATE THROUGH
THE SHORT TERM.
.LONG TERM.../TUESDAY NIGHT THROUGH SATURDAY/
MODELS ARE IN SURPRISING GOOD AGREEMENT TO BEGIN THIS FORECAST. LOW
PRESSURE OVER EASTERN INDIANA WITH A WARM FRONT EXTENDING TO ERN PA
AND A COLD FRONT SOUTH BETWEEN EVV AND SDF. THE GFS IS ABOUT 50
MILES MORE ADVANCED WITH THE COLD FRONT THAN THE ECMWF SO HAVE USED
A COMPROMISE. BY SUNRISE ON WED THE CLD FRONT HAS MADE THE LEAP TO
THE ERN SLOPES OF THE APPALACHIANS AND PCP IS MOVING OUT OF KY. THE
ECMWF IS ABOUT 6 HRS SLOWER WITH THE DEPARTING SYSTEM AND DOES NOT
BRING IN THE COOLER AIR ON THE NORTHERLY WIND UNTIL NEARLY 00Z ON
THU. BY 12Z BOTH MODELS HAVE THE HIGH PRESSURE CENTERED NEARLY
OVERHEAD OF ERN KY. THE GFS DOES BEGIN BRINGING MOISTURE NORTH
AROUND THE BACK SIDE OF THE HIGH PRESSURE BY FRI MORNING AND PLACES
PCPN ALONG THE MISS RIVER BY FRI AFTERNOON. WHERE AS THE ECMWF DOES
NOT BRING RETURN MOISTURE UNTIL LATE FRIDAY AND ANY PCPN FRI
AFTERNOON IS STILL CONFINED TO THE PLAINS. THE NEXT COLD FRONT WILL
PUSH INTO AND THROUGH ERN KY ON SUNDAY. AGAIN THE GFS IS FASTER BY
ALMOST 12 HRS THIS TIME AND THE MODEL CONSENSUS HAS MADE FOR A DECENT
COMPROMISE WITH THE FIRST PCPN LEADING THE FRONT ON SAT AFTERNOON.
EXPECT TEMPERATURES TO TAKE AN INITIAL TUMBLE WITH WED HIGHS ONLY IN
THE LOWER 50S BUT WARMING TO THE MID 50S BY THANKSGIVING AND THEN
INTO THE 60S FOR FRI AND INTO SAT. BY SUN THE NEXT COLD FRONT WILL
ONCE AGAIN DROP HIGH TEMPS TO THE 50S.
&&
.AVIATION.../18Z TO 18Z/...UPDATED
A BAND OF RAIN WILL MOVE EAST ACROSS KENTUCKY THIS AFTERNOON. CIGS
ARE EXPECTED TO REMAIN VFR WITHIN THIS AREA OF RAIN...ALTHOUGH A
SLIGHT REDUCTION IN VISIBILITY IS POSSIBLE IN THE HEAVIER RAIN. THE
RAIN WILL EXIT BY MID EVENING...LEAVING BEHIND ONLY SOME LIGHT
SCATTERED SHOWERS FOR THE OVERNIGHT HOURS. HOWEVER...STRATUS WILL
REMAIN LOCKED IN OVER THE AREA OVERNIGHT AND WILL ACTUALLY LOWER
THROUGH THE NIGHT...REACHING IFR/LIFR CATEGORIES BY 06Z. THE RIDGE
TOPS AIRPORTS WILL LIKELY SEE THE STRATUS BUILD DOWN INTO A FOG LAYER
TOWARDS DAYBREAK...RESTRICTING VISIBILITIES TO A QUARTER MILE OR
LESS. THE STRATUS WILL BEGIN TO LIFT BACK TO MVFR AFTER DAYBREAK WITH
MORE RAIN SHOWERS ARRIVING AROUND MIDDAY. LLWS MAY BE MARGINAL
TONIGHT AND MAY NEED TO BE ADDED LATER...BUT OPTED TO HOLD OFF FOR
NOW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...GEOGERIAN/KAS
LONG TERM....DUSTY
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1032 PM EST MON NOV 21 2011
.SYNOPSIS...
AFTER A PERIOD OF ISOLATED TO SCATTERED SHOWERS THROUGH TUESDAY
MORNING...A STORM SYSTEM OVER THE SOUTHERN PLAINS TONIGHT WILL
APPROACH THE OHIO VALLEY ON TUESDAY AND BRING SIGNIFICANT RAINS
TO THE AREA LATE TUESDAY INTO WEDNESDAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR THANKSGIVING DAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
9:40 PM UPDATE: ADJUSTED TEMPS, DEW POINTS AND SKY TO BETTER FIT
OBSERVATIONS...NO OTHER CHANGES.
23UTC HRRR FOLLOWS TREND OF KEEPING PRECIP SOUTH OF AREA
OVERNIGHT. THEREFORE...CONTINUED SCATTERED SHOWERS MAINLY SOUTH
OF THE MASON DIXON...WITH MAINLY DRY CONDITIONS FROM A ZZV/AGC/LBE
LINE NORTHWARD. WITH CLOUDS PERSISTING...TEMPERATURES WILL FALL
LITTLE TNGT.
AFTER A MAINLY DRY EARLY MORNING...A DEVELOPING STORM SYSTEM WILL
APPROACH THE AREA TUESDAY AFTN. POP WILL INCREASE TO LIKELY SOUTH
OF THE MASON DIXON BY TUESDAY AFTN...SPREADING NORTHWARD BY
EVENING. WITH SOME INSTABILITY IN ADVANCE OF THE BOUNDARY...WILL
CONTINUE A SLIGHT CHC OF THUNDERSTORMS TUESDAY AFTN. EXPECT HIGH
TEMPERATURES RANGING FROM THE LOWER 50S NORTH OF I-80...TO AROUND
60 SOUTH OF I-70.
&&
.SHORT TERM /TUESDAY NIGHT/...
THE FRONTAL BOUNDARY IS PROJECTED TO CROSS THE AREA TUESDAY
NIGHT INTO EARLY WEDNESDAY. IN THE WAKE OF THE FRONT...WRAP
AROUND MOISTURE WITH THE UPPER LEVEL LOW WILL LINGER INTO
WEDNESDAY AFTN...EXITING BY WEDNESDAY NIGHT.
RAINFALL WILL BE A CONCERN GIVEN SOME DEEP MOISTURE TAP. 00 TC
MODEL RUNS CONTINUE TO SHOW 1-2 INCHES OF RAINFALL...WITH THE
GREATEST AMOUNTS LIKELY NORTH AND WEST OF THE OHIO RIVER. WILL
NOT ISSUE A FLOOD WATCH AT THIS TIME...AND WILL INCLUDE POSSIBLE
IMPACTS IN DSS PACKAGE TO COUNTIES.
ABOVE NORMAL TEMPERATURES TUESDAY/TUESDAY NIGHT WILL GIVE WAY TO
NEAR STEADY/FALLING TEMPERATURES WEDNESDAY IN THE WAKE OF THE
TROUGH/SFC COLD FRONT. RESIDUAL RIDGE SHOWERS WILL END WEDNESDAY
EVENING...WITH A DRY AND SEASONABLE THANKSGIVING DAY ON TAP.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
THERE IS STRONG MODEL AGREEMENT THAT A MID-LEVEL RIDGE ALONG WITH A
BROAD AREA OF HIGH PRESSURE WILL BRING DRY WEATHER TO THE UPPER OHIO
VALLEY THURSDAY NIGHT THROUGH MUCH OF THE DAY ON SATURDAY. ABUNDANT
SUNSHINE CAN BE EXPECTED UNTIL CLOUDS BEGIN TO INCREASE FROM THE
WEST ON SATURDAY. THUS, TEMPERATURES WILL BE 5 TO 10 DEGREES ABOVE
NORMAL AND WARMER EACH DAY.
SOME UNCERTAINTY ENTERS THE FORECAST FOR SATURDAY NIGHT INTO MONDAY
AS A TROUGH ACROSS THE MIDWEST CLOSES OFF INTO AN UPPER LOW.
FORECAST IS A GFS/ECMWF BLEND WITH THE CHANCE OF SHOWERS EACH DAY
THROUGH THIS PERIOD. FORECAST TEMPS ARE AROUND 5 DEGREES ABOVE
NORMAL FOR THE LATE WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
PER BLEND OF RECENT SURFACE AND RADAR DATA COUPLED WITH NAM, SREF
AND GFS LAMP MODEL OUTPUT, EXPECT NEARBY WARM FRONT TO MAINTAIN
IFR CONDITIONS ACROSS THE UPPER OHIO VALLEY FOR THE TAF PERIOD
ENDING 00Z WEDNESDAY. ALTHOUGH THERE MAY BE BREAKS IN THE STRATUS
CEILINGS AT TIMES THROUGH 06Z, EXPECT MOST CEILING TO DETERIORATE
TO LIFR LEVELS BY 12Z. VISIBILITIES IN FOG AND PATCHY DRIZZLE
WILL BE SLOWER TO DETERIORATE, AND IN SOME AREAS NOT BECOME IFR
UNTIL LATE TONIGHT OR DAYTIME TUESDAY.
INCOMING LOW PRESSURE CENTER WILL SPREAD RAIN SOUTHWEST TO
NORTHEAST ACROSS THE AREA WEDNESDAY. THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS LATE IN THE AFTERNOON AND EVENING.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
EXPECT WIDESPREAD IFR WITH RAIN AND FOG INTO MIDDAY WEDNESDAY,
FOLLOWED BY IMPROVEMENT TO VFR BY WEDNESDAY EVENING. PATCHY FOG
WITH RESTRICTIONS POSSIBLE THURSDAY MORNING, OTHERWISE, EXPECT VFR
TO PREVAIL INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
946 PM EST MON NOV 21 2011
.SYNOPSIS...
AFTER A PERIOD OF ISOLATED TO SCATTERED SHOWERS THROUGH TUESDAY
MORNING...A STORM SYSTEM OVER THE SOUTHERN PLAINS TONIGHT WILL
APPROACH THE OHIO VALLEY ON TUESDAY AND BRING SIGNIFICANT RAINS
TO THE AREA LATE TUESDAY INTO WEDNESDAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR THANKSGIVING DAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
9:40 PM UPDATE: ADJUSTED TEMPS, DEW POINTS AND SKY TO BETTER FIT
OBSERVATIONS...NO OTHER CHANGES.
23UTC HRRR FOLLOWS TREND OF KEEPING PRECEP SOUTH OF AREA
OVERNIGHT. THEREFORE...CONTINUED SCATTERED SHOWERS MAINLY SOUTH
OF THE MASON DIXON...WITH MAINLY DRY CONDITIONS FROM A ZZV/AGC/LBE
LINE NORTHWARD. WITH CLOUDS PERSISTING...TEMPERATURES WILL FALL
LITTLE TNGT.
AFTER A MAINLY DRY EARLY MORNING...A DEVELOPING STORM SYSTEM WILL
APPROACH THE AREA TUESDAY AFTN. POP WILL INCREASE TO LIKELY SOUTH
OF THE MASON DIXON BY TUESDAY AFTN...SPREADING NORTHWARD BY
EVENING. WITH SOME INSTABILITY IN ADVANCE OF THE BOUNDARY...WILL
CONTINUE A SLIGHT CHC OF THUNDERSTORMS TUESDAY AFTN. EXPECT HIGH
TEMPERATURES RANGING FROM THE LOWER 50S NORTH OF I-80...TO AROUND
60 SOUTH OF I-70.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
THE FRONTAL BOUNDARY IS PROJECTED TO CROSS THE AREA TUESDAY
NIGHT INTO EARLY WEDNESDAY. IN THE WAKE OF THE FRONT...WRAP
AROUND MOISTURE WITH THE UPPER LEVEL LOW WILL LINGER INTO
WEDNESDAY AFTN...EXITING BY WEDNESDAY NIGHT.
RAINFALL WILL BE A CONCERN GIVEN SOME DEEP MOISTURE TAP. 00 UTC
MODEL RUNS CONTINUE TO SHOW 1-2 INCHES OF RAINFALL...WITH THE
GREATEST AMOUNTS LIKELY NORTH AND WEST OF THE OHIO RIVER. WILL
NOT ISSUE A FLOOD WATCH AT THIS TIME...AND WILL INCLUDE POSSIBLE
IMPACTS IN DSS PACKAGE TO COUNTIES.
ABOVE NORMAL TEMPERATURES TUESDAY/TUESDAY NIGHT WILL GIVE WAY TO
NEAR STEADY/FALLING TEMPERATURES WEDNESDAY IN THE WAKE OF THE
TROUGH/SFC COLD FRONT. RESIDUAL RIDGE SHOWERS WILL END WEDNESDAY
EVENING...WITH A DRY AND SEASONABLE THANKSGIVING DAY ON TAP.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THERE IS STRONG MODEL AGREEMENT THAT A MID-LEVEL RIDGE ALONG WITH A
BROAD AREA OF HIGH PRESSURE WILL BRING DRY WEATHER TO THE UPPER OHIO
VALLEY THURSDAY NIGHT THROUGH MUCH OF THE DAY ON SATURDAY. ABUNDANT
SUNSHINE CAN BE EXPECTED UNTIL CLOUDS BEGIN TO INCREASE FROM THE
WEST ON SATURDAY. THUS, TEMPERATURES WILL BE 5 TO 10 DEGREES ABOVE
NORMAL AND WARMER EACH DAY.
SOME UNCERTAINTY ENTERS THE FORECAST FOR SATURDAY NIGHT INTO MONDAY
AS A TROUGH ACROSS THE MIDWEST CLOSES OFF INTO AN UPPER LOW.
FORECAST IS A GFS/ECMWF BLEND WITH THE CHANCE OF SHOWERS EACH DAY
THROUGH THIS PERIOD. FORECAST TEMPS ARE AROUND 5 DEGREES ABOVE
NORMAL FOR THE LATE WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
PER BLEND OF RECENT SURFACE AND RADAR DATA COUPLED WITH NAM, SREF
AND GFS LAMP MODEL OUTPUT, EXPECT NEARBY WARM FRONT TO MAINTAIN
IFR CONDITIONS ACROSS THE UPPER OHIO VALLEY FOR THE TAF PERIOD
ENDING 00Z WEDNESDAY. STRATUS CEILINGS CAN DETERIORATE TO LIFR
LEVELS. VISIBILITIES IN FOG AND PATCHY DRIZZLE WILL BE SLOWER TO
DETERIORATE, AND IN SOME AREAS NOT BECOME IFR UNTIL LATE TONIGHT
OR DAYTIME TUESDAY.
INCOMING LOW PRESSURE CENTER WILL SPREAD RAIN SOUTHWEST TO
NORTHEAST ACROSS THE AREA WEDNESDAY. THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS LATE IN THE AFTERNOON AND EVENING.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
EXPECT WIDESPREAD IFR WITH RAIN AND FOG INTO MIDDAY WEDNESDAY,
FOLLOWED BY IMPROVEMENT TO VFR BY WEDNESDAY EVENING. PATCHY FOG
WITH RESTRICTIONS POSSIBLE THURSDAY MORNING, OTHERWISE, EXPECT VFR
TO PREVAIL INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
755 PM EST MON NOV 21 2011
.SYNOPSIS...
AFTER A PERIOD OF ISOLATED TO SCATTERED SHOWERS THROUGH TUESDAY
MORNING...A STORM SYSTEM OVER THE SOUTHERN PLAINS TONIGHT WILL
APPROACH THE OHIO VALLEY ON TUESDAY AND BRING SIGNIFICANT RAINS
TO THE AREA LATE TUESDAY INTO WEDNESDAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR THANKSGIVING DAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
7:50 PM UPDATE: ADJUSTED TEMPS AND SKY TO BETTER FIT
OBSERVATIONS...NO OTHER CHANGES.
22UTC HRRR CONTINUES TREND OF KEEPING PRECEP SOUTH OF AREA
OVERNIGHT. THEREFORE...CONTINUES SCATTERED SHOWERS MAINLY SOUTH
OF THE MASON DIXON...WITH MAINLY DRY CONDITIONS FROM A ZZV/AGC/LBE
LINE NORTHWARD. WITH CLOUDS PERSISTING...TEMPERATURES WILL FALL
LITTLE TNGT.
THE FRONTAL BOUNDARY WILL CONTINUE ITS PUSH BACK TO THE NORTH
TUESDAY. AFTER A MAINLY DRY EARLY MORNING...A DEVELOPING STORM
SYSTEM WILL APPROACH THE AREA TUESDAY AFTN. POP WILL INCREASE TO LIKELY
SOUTH OF THE MASON DIXON BY TUESDAY AFTN...SPREADING NORTHWARD
DURING BY EVENING. WITH SOME INSTABILITY IN ADVANCE OF THE
BOUNDARY...WILL CONTINUE A SLIGHT CHC OF THUNDERSTORMS TUESDAY
AFTN. EXPECT HIGH TEMPERATURES RANGING FROM THE LOWER 50S NORTH OF
I-80...TO AROUND 60 SOUTH OF I-70.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
THE FRONTAL BOUNDARY IS PROJECTED TO CROSS THE AREA TUESDAY
NIGHT INTO EARLY WEDNESDAY. IN THE WAKE OF THE FRONT...WRAP
AROUND MOISTURE WITH THE UPPER LEVEL LOW WILL LINGER INTO
WEDNESDAY AFTN...EXITING BY WEDNESDAY NIGHT.
RAINFALL WILL BE A CONCERN GIVEN SOME DEEP MOISTURE TAP. LATEST
PROJECTIONS ARE FOR 1-2 INCHES OF RAINFALL...WITH THE GREATEST
AMOUNTS LIKELY WEST OF THE OHIO RIVER. GIVEN SOME UNCERTAINTY WITH
THE POSITION OF THE SURFACE LOW AND THE GREATEST MID LEVEL
FORCING...WILL NOT ISSUE A FLOOD WATCH AT THIS TIME...AND WILL
INCLUDE POSSIBLE IMPACTS IN THE HAZARDOUS WEATHER OUTLOOK.
ABOVE NORMAL TEMPERATURES TUESDAY/TUESDAY NIGHT WILL GIVE WAY TO
NEAR STEADY/FALLING TEMPERATURES WEDNESDAY IN THE WAKE OF THE
TROUGH/SFC COLD FRONT. RESIDUAL RIDGE SHOWERS WILL END WEDNESDAY
EVENING...WITH A DRY AND SEASONABLE THANKSGIVING DAY ON TAP.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THERE IS STRONG MODEL AGREEMENT THAT A MID-LEVEL RIDGE ALONG WITH A
BROAD AREA OF HIGH PRESSURE WILL BRING DRY WEATHER TO THE UPPER OHIO
VALLEY THURSDAY NIGHT THROUGH MUCH OF THE DAY ON SATURDAY. ABUNDANT
SUNSHINE CAN BE EXPECTED UNTIL CLOUDS BEGIN TO INCREASE FROM THE
WEST ON SATURDAY. THUS, TEMPERATURES WILL BE 5 TO 10 DEGREES ABOVE
NORMAL AND WARMER EACH DAY.
SOME UNCERTAINTY ENTERS THE FORECAST FOR SATURDAY NIGHT INTO MONDAY
AS A TROUGH ACROSS THE MIDWEST CLOSES OFF INTO AN UPPER LOW.
FORECAST IS A GFS/ECMWF BLEND WITH THE CHANCE OF SHOWERS EACH DAY
THROUGH THIS PERIOD. FORECAST TEMPS ARE AROUND 5 DEGREES ABOVE
NORMAL FOR THE LATE WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
PER BLEND OF RECENT SURFACE AND RADAR DATA COUPLED WITH NAM, SREF
AND GFS LAMP MODEL OUTPUT, EXPECT NEARBY WARM FRONT TO MAINTAIN
IFR CONDITIONS ACROSS THE UPPER OHIO VALLEY FOR THE TAF PERIOD
ENDING 00Z WEDNESDAY. STRATUS CEILINGS CAN DETERIORATE TO LIFR
LEVELS. VISIBILITIES IN FOG AND PATCHY DRIZZLE WILL BE SLOWER TO
DETERIORATE, AND IN SOME AREAS NOT BECOME IFR UNTIL LATE TONIGHT
OR DAYTIME TUESDAY.
INCOMING LOW PRESSURE CENTER WILL SPREAD RAIN SOUTHWEST TO
NORTHEAST ACROSS THE AREA WEDNESDAY. THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS LATE IN THE AFTERNOON AND EVENING.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
EXPECT WIDESPREAD IFR WITH RAIN AND FOG INTO MIDDAY WEDNESDAY,
FOLLOWED BY IMPROVEMENT TO VFR BY WEDNESDAY EVENING. PATCHY FOG
WITH RESTRICTIONS POSSIBLE THURSDAY MORNING, OTHERWISE, EXPECT VFR
TO PREVAIL INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
517 PM CST MON NOV 21 2011
.AVIATION...00Z TAF. MID AND HIGH LEVEL CLOUDS CONTINUE TO
INCREASE THIS AFTERNOON AS AN UPPER LEVEL DISTURBANCE MOVES INTO
THE CENTRAL AND SOUTHERN PLAINS. THE MID AND HIGH LEVEL CLOUDS
HAVE COVERED AN AREA OF STRATUS WHICH IS IN PLACE TO THE SOUTH AND
EAST OF KGRI. THE LATEST RUC PROXIMITY SOUNDINGS SUGGEST THAT THE
STRATUS COULD MOVE INTO KGRI FOR A PERIOD OF TIME THIS
EVENING...WHILE THE NAM SOUNDINGS ARE NOT AS AGGRESSIVE WITH THE
STRATUS. WILL BRING IN SCATTERED LOWER CLOUDS TO HINT AT THE
POSSIBILITY OF THE STRATUS REACHING KGRI...BUT WILL NOT GO WITH A
CEILING JUST YET SINCE SREF PROBABILITIES SUGGEST THE LOWER CLOUDS
WILL PROBABLY STAY JUST TO THE SOUTH AND EAST. WINDS WILL BE LIGHT
AND VARIABLE TONIGHT...BUT MAY FAVOR MORE OF A WESTERLY DIRECTION
ON TUESDAY.
&&
.PREV DISCUSSION... /ISSUED 345 PM CST MON NOV 21 2011/
SHORT TERM...TONIGHT THROUGH TUESDAY. 12Z AND 18Z NAM/GFS MODELS
HAVE CONTINUED TO COME IN FURTHER SOUTH WITH THE PRECIPITATION AND
WARMER IN AREAS THAT ARE EXPECTED TO SEE PRECIPITATION. THE
PRECIPITATION WILL PRIMARILY BE CONFINED TO OUR NORTHERN KANSAS
ZONES ALTHOUGH THERE IS STILL A VERY SLIGHT CHANCE OF RAIN ACROSS
FAR SOUTHERN NEBRASKA RIGHT ALONG THE KANSAS BORDER. IN
ADDITION...THE 09Z AND 15Z SREF ENSEMBLES ARE INDICATING A 5
PERCENT OR LESS CHANCE OF 0.01 LIQUID ACCUMULATION IN THE TRI
CITIES...KEEPING ACCUMULATING RAIN TO THE SOUTH. THE 09Z AND 15Z
ENSEMBLE MEAN TEMPERATURE IS AT OR ABOVE 32F FOR ALL LOCATIONS
WITH POPS OF 20 PERCENT OR HIGHER...SO PLACES THAT SEE
PRECIPITATION SHOULD LIKELY SEE IT FALL AS LIQUID.
THE POSSIBILITY OF FREEZING RAIN LATE TONIGHT INTO EARLY TOMORROW
MORNING IS TOO LOW TO MENTION IN THE OFFICIAL FORECAST. HOWEVER...WITH
TEMPERATURES JUST BARELY ABOVE FREEZING...WILL STILL NEED TO WATCH
OUT FOR THIS VERY SLIGHT POSSIBILITY SHOULD TEMPERATURES DROP BY
A FEW DEGREES MORE THAN CURRENTLY EXPECTED. OTHER FACTORS THAT GO
AGAINST SEEING FREEZING PRECIPITATION IS THAT THE SFC WIND IS
VERY LIGHT...WHICH CUTS DOWN ON EVAPORATIVE COOLING...AND THERE IS
ALSO NO COLD AIR ADVECTION TO REINFORCE THE COOLER SFC
TEMPERATURES. THEREFORE...TEMPERATURES MAY EVEN WARM SOME AS RAIN
COMING FROM WARMER AIR FALLS TO THE SURFACE...ASSUMING IT RAINS AT
ALL. IN OTHER WORDS...ADVERSE WINTER DRIVING CONDITIONS TUESDAY
MORNING SEEM UNLIKELY.
TEMPERATURES WILL WARM UP NICELY LATE TUESDAY MORNING INTO THE
AFTERNOON HOURS WITH INCREASING SUNSHINE. TUESDAY HIGH
TEMPERATURES WILL RANGE FROM AROUND 50 IN THE TRI CITIES TO THE
MID 50S ACROSS PORTIONS OF NORTH CENTRAL KANSAS.
LONG TERM...TUESDAY NIGHT THROUGH MONDAY. PRIMARY FORECAST
CONCERN LIES WITH PRECIPITATION CHANCES/FRONTAL PASSAGE
AFFECTING THE END OF THE WEEK/WEEKEND.
LITTLE CHANGES NEEDED TO THE FORECAST FOR TUESDAY NIGHT THROUGH
THANKSGIVING...WITH DRY CONDITIONS REMAINING. THE MODELS CONTINUE TO
BE IN GOOD AGREEMENT WITH THE OVERALL PATTERN...SHOWING
NORTHWESTERLY FLOW IN THE UPPER LEVELS TO START THE PERIOD...AS THE
SHORTWAVE DISTURBANCE PUSHES FURTHER INTO THE MIDWEST AND RIDGING
BUILDS ACROSS THE ROCKIES. BY WEDNESDAY NIGHT...THE RIDGE AXIS
SHIFTS EAST ONTO THE PLAINS...AND LOOKS TO BE CENTERED OVER THE CWA.
BY THE TIME THURSDAY EVENING ROLLS AROUND...THE RIDGE AXIS HAS
SHIFTED EAST AS A TROUGH PUSHES INTO THE ROCKIES. AT THE
SURFACE...SEE WESTERLY WINDS TO START OUT ON WEDNESDAY AS THE CWA
SITS BETWEEN LOW PRESSURE SHIFTING ACROSS SRN CANADA AND HIGH
PRESSURE GRADUALLY MOVING EAST INTO THE MIDWEST/GULF COAST REGIONS.
A MORE SOUTHERLY COMPONENT DEVELOPS LATE WEDNESDAY AND CONTINUES
INTO THURSDAY...AS A TROUGH OF LOW PRESSURE SETS UP ALONG THE HIGH
PLAINS AHEAD OF THE NEXT UPPER LEVEL SYSTEM. WINDS WILL LIKELY BE A
BIT GUSTY ON THURSDAY 15 TO 20 MPH WITH GUSTS NEAR 25 MPH...MAINLY
ACROSS THE SOUTHEASTERN HALF OF THE CWA...WITH THE REMAINDER SITTING
CLOSER TO THE TROUGH AXIS AND SPEEDS MORE IN THE 10 TO 15 MPH
RANGE. ALSO NO CHANGE IN THE FACT THAT THESE TWO DAYS WILL BE THE
WARMEST OF THE LONG TERM PERIOD...AS WARMER AIR ACCOMPANYING THE
UPPER LEVEL RIDGE AND PLENTY OF SUN WILL ALLOW FOR HIGHS BOTH DAYS
IN THE MID/UPPER 50S TO LOWER/MID 60S.
AS WE GET INTO FRIDAY AND THE WEEKEND TIME FRAME...DO SEE A PATTERN
CHANGE. MODELS NOT IN TOO BAD OF AGREEMENT WITH THIS NEXT
SYSTEM...WHICH AT 12Z FRIDAY IS AN OPEN TROUGH AXIS MAINLY LOCATED
OVER CO/NM. KEPT THE OVERNIGHT THURSDAY/EARLY FRIDAY MORNING HOURS
DRY...BUT THROUGH THE DAYTIME/EVENING HOURS ON FRIDAY...INCREASING
LIFT ASSOCIATED WITH THE APPROACHING TROUGH AXIS WILL BRING CHANCES
FOR PRECIPITATION. THERE ARE SOME SLIGHT DIFFERENCES WITH THE AREA
THAT IS IMPACTED...WITH THIS MORNINGS GFS KEEPING THINGS JUST OFF TO
THE E/SE OF THE CWA...WHILE THE LATEST ECMWF CLIPS THE SOUTHEASTERN
HALF. WILL GO WITH LOWER END POPS ACROSS AN AREA CLOSER TO THE
ECMWF. THE TEMP PROFILES BEING ON THE WARM SIDE KEEP PTYPE AS
LIQUID. EXPECTING ANY PRECIPITATION TO COME TO AN END BY 12Z
SATURDAY...WITH THE REMAINDER OF THE WEEKEND FORECAST ACTUALLY BEING
DRY AS MODELS SIT IN DECENT AGREEMENT SHOWING AN UPPER LEVEL CLOSED
LOW PRESSURE SYSTEM DEVELOPING AS THIS TROUGH CROSSES THE MO RIVER
AND SHIFTS INTO THE MIDWEST...BUT THEN IS SLOW TO MAKE MUCH
PROGRESS. A SURFACE COLD FRONT ACCOMPANYING THIS TROUGH IS EXPECTED
TO PUSH THROUGH THE CWA FRIDAY NIGHT...BRINGING INCREASED SOUTHERLY
WINDS AS HIGH PRESSURE BUILDS IN. COULD SEE WINDS ON SATURDAY
APPROACHING 25 TO 30 MPH SUSTAINED AS THE PRESSURE GRADIENT TIGHTENS
UP ACROSS THE CENTRAL PLAINS. MAIN CHANGE WILL COME WITH THE
TEMPERATURES ACCOMPANYING THE FRONTAL PASSAGE...WITH THE COLDER AIR
BUILDING IN EXPECTED TO DROP HIGHS SAT/SUN INTO THE LOWER/MID
40S...AND SOME MODELS/GUIDANCE SUGGESTS THIS ISNT COOL ENOUGH FOR
SOME LOCATIONS.
SHOULD SEE A BIT OF A REBOUND INTO MONDAY AS THE CORE OF THE COOLEST
AIR SHIFT OFF TO THE EAST AND WARMER AIR MOVE IN...WITH HIGHS
CREEPING BACK INTO THE 50S.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1237 AM EST SUN NOV 20 2011
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE THIS WEEKEND AND INTO EARLY NEXT
WEEK. TEMPERATURES WILL BEGIN TO WARM OVER THE WEEKEND AS SOUTHERLY
WINDS DEVELOP. A COLD FRONT WILL MOVE THROUGH WEDNESDAY. COOLER
WEATHER IS EXPECTED LATE NEXT WEEK AS HIGH PRESSURE BUILDS IN.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 10 PM SATURDAY...LIGHT EASTERLY/ONSHORE FLOW HAS
DEVELOPED AS SURFACE RIDGE AXIS MOVES OFFSHORE...BRINGING
TEMPERATURES ALONG THE COAST UP A TAD...IN THE LOWER TO MID 60S
MANY LOCATIONS. WILL LOOK AT MODIFYING THE TEMPERATURE CURVE IF
NEED BE TO ACCOUNT FOR THIS. OTHERWISE...FORECAST REMAINS ON
TRACK. PREVIOUS DISCUSSIONS FOLLOW:
QUITE A DIFFERENCE FROM 24 HOURS AGO. RADIATIONAL COOLING
CONDITIONS NOT NEARLY AS FAVORABLE...WITH PATCHES OF STRATO-CU
BLANKETING THE AREA AND MOISTER LOWER LEVELS THAN THIS TIME
YESTERDAY. TEMPERATURES HAVE BEEN SLOWER TO FALL AND RANGE FROM
THE 50S INLAND TO AROUND 60 AT THE COAST. AS DESCRIBED IN PREVIOUS
DISCUSSION BELOW...EXPECT A RELATIVELY MILD NIGHT. WILL LIKELY SEE
FOG DEVELOP OVERNIGHT MOST LOCATIONS.
SURFACE TROUGH REMAINING JUST TO THE EAST OF LOCAL COASTAL WATERS
WILL SHIFT FARTHER WEST CLOSER TO THE CAROLINA COAST THROUGH THIS
EVENING BEFORE DISSIPATING OVERNIGHT. LIGHT NORTHEAST FLOW ON WEST
SIDE OF TROUGH WILL SHIFT MORE EASTERLY ESPECIALLY ALONG THE COAST
AS IT SHIFTS CLOSER. OVERALL WEAK GRADIENT WITH WINDS REMAINING 5
MPH OR LESS MOST PLACES AT THE SURFACE. RUC SOUNDINGS SHOWING AN
OVERALL WARMING AND DRYING OF THE COLUMN AT LOW LEVELS AS WARMER
AIR MAKES ITS WAY IN ALOFT AND MIXING OCCURS THROUGH TODAY...BUT
DECENT ON SHORE SE FLOW AT H85 CONTINUING TO BRING MOISTURE AND
SOME CLOUDS ON SHORE MAINLY OVER SC.
ON SHORE FLOW WILL CAPTURE SOME OF THE MARINE INFLUENCE CONTINUING
TO BRING HIGHER DEWPOINT AIR INLAND AS WINDS SHIFT BECOMING MORE
EASTERLY. THE DEWPOINTS ALONG THE COAST WILL REMAIN IN THE 50S
THROUGH MOST OF THE NIGHT WHILE INLAND DEWPOINTS WILL BE IN THE
MID 40S. WAA WILL CONTINUE WITH SW FLOW ABOVE THE SURFACE. 850
TEMPS AROUND 4 TO 5 C THIS MORNING WILL RISE UP TO AROUND 8C BY
DAYBREAK ON SUNDAY. LOW LEVEL FLOW WILL CONTINUE TO COME AROUND
FROM S-SE TO SW OVERNIGHT WHILE SURFACE WINDS BECOME VERY LIGHT
AND VARIABLE TO NEAR CALM. CLOUDS ASSOCIATED WITH COASTAL TROUGH
MAY MOVE ON SHORE THROUGH THIS EVENING AS H85 FLOW CONTINUES OUT
OF THE SE BEFORE SHIFTING TO S-SW OVERNIGHT. THE SFC TROUGH AXIS
SHIFTS A LITTLE FARTHER WEST BUT DISSIPATES OVERNIGHT AS HIGH
PRESSURE CONTINUES TO RIDGE BACK INTO THE CAROLINAS. OVERALL VERY
WEAK PRESSURE PATTERN EXPECTED WITH CALM WINDS. FOR NOW WILL KEEP
MOST CLOUDS OUT OF THE EQUATION ALLOWING FOR MORE IDEAL
RADIATIONAL COOLING AND DENSER FOG THREAT...BUT THE EXTENT OF FOG
WILL DEPEND ON HOW MUCH CLOUD COVER THERE WILL BE...WHICH WILL BE
THE FORECAST CHALLENGE OVERNIGHT.
TEMPS WILL DROP OFF AS WE RADIATE OUT OVER MOST PLACES BUT
WAA...INCREASED LOW LEVEL MOISTURE AND SOME CLOUDS WILL KEEP TEMPS
AND SFC DEWPOINTS HIGHER THAN PREVIOUS NIGHTS. FORECAST LOWS WILL
THEREFORE DROP TO THE LOW TO MID 40S MOST PLACES INLAND AND CLOSER
TO 50 ALONG THE COAST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...HIGH PRESSURE WILL SHIFT OFF THE COAST SUNDAY
AND RESULT IN WARMING S-SW FLOW THROUGH THE PERIOD. THERE WILL BE
SOME INCREASE IN CLOUDS MONDAY NIGHT AS A FRONTAL SYSTEM APPROACHES
FROM THE WEST...OTHERWISE FAIR WEATHER IS EXPECTED. HIGHS WILL
MODERATE SLIGHTLY EACH DAY...MODERATING FROM THE LOWER 70S SUNDAY TO
THE MIDDLE 70S MONDAY. LOWS SUNDAY NIGHT WILL FALL TO THE UPPER 40S
TO LOWER 50S WITH MID TO UPPER 50S EXPECTED MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...DAYBREAK TUESDAY AN UPPER TROUGH AXIS WILL
BE POSITIONED ROUGHLY ALONG THE MISSISSIPPI VALLEY...WITH SURFACE
HIGH PRESSURE SITUATED OFFSHORE OF THE CAROLINAS. EARLY TUESDAY A
WARM FRONT WILL RESIDE NORTH OF THE AREA...SO NO MENTIONABLE POP
VALUES PLANNED UNTIL TUESDAY NIGHT AS A COLD FRONT BREAKS EAST OF
THE APPALACHIAN MOUNTAINS. FRONTAL PASSAGE BASED ON AN GFS/ECMWF
CONSENSUS SOMETIME WEDNESDAY EITHER SIDE OF MIDDAY. SHRA TAPERING
OFF AND COLD AIR ADVECTION REGIME WEDNESDAY NIGHT AND A CLEARING
TREND INTO EARLY THURSDAY.
HENCE A DRY FORECAST DAY 6/7 FRI/SAT ALTHOUGH WE MAY EXPECT RETURN
FLOW NEXT WEEKEND AS THE PATTERN SHOWS A PROGRESSIVE NATURE.
TEMPERATURES 7-10 DEG F ABOVE NORMAL TUE/WED IN WARM SECTOR OF THE
APPROACHING FRONT...KNOCKED DOWN TO NORMAL DIURNAL TEMPERATURE
CURVES FOR NOVEMBER THU/FRI...THEN WARMING INTO NEXT SATURDAY.
THANKSGIVING DAY LOOKS SUNNY AND COOL. THE COLDEST MORNING IN THE
EXTENDED FORECAST LOOKS TO BE FRIDAY MORNING AS THE HIGH SETTLES
OVERHEAD BENEATH A CLEAR DOME...SO FREEZING TEMPS POSSIBLE THEN.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...LATEST 11U-3.9U MICRON SATELLITE IMAGERY IS DETECTING
SCATTERED TO BROKEN LOW/MID-LEVEL CLOUDS ALONG AND WEST OF I-95
...AND LOW/MID LEVEL CLOUDS OFFSHORE FROM THE CAROLINAS.
MVFR VISIBILITIES IN BR HAVE DEVELOPED ACROSS THE MAJORITY OF THE
TERMINALS...IE. FLO/LBT/MYR.
FORECAST SOUNDINGS ARE INDICATING CLOUDS WILL SCATTER OVER THE NEXT
SEVERAL HOURS ALONG AND WEST OF I-95...LEAVING SCT OR SKC FOR SKY
CONDITIONS. WITH NEARLY CLEAR SKIES AND CALM WINDS THROUGH
SUNRISE...THE FOG WILL ULTIMATELY WORSEN...REACHING OCCASIONALLY THE
DENSE CRITERIA. HAVE INCLUDED AT ALL SITES...THIS INCREASED FOG
POTENTIAL PLACING IT AS THE PREDOMINATE VSBY ACROSS THE COASTAL
SITES. WILL ONLY INDICATE TEMPO MVFR VISIBILITIES AT ALL SITES FROM
ANY REMAINING CLOUDS...IE. 3.5 KFT OR HIGHER.
EXPECT COASTAL TERMINALS TO BECOME VFR 12-14Z AND THE FLO/LBT
13-15Z. VFR EXPECTED THE REMAINDER OF THE DAY THROUGH THE EVENING
HOURS WITH VARIABLE WINDS IN THE AM HRS...BECOMING LIGHT SOUTH TO
SOUTHWEST BY MIDDAY AND CONTINUING INTO THE EVENING HRS.
EXTENDED OUTLOOK...LOW CONFIDENCE IN FOG MONDAY/TUESDAY MORNINGS AND
ISOLATED SHOWERS DURING THE AFTERNOONS. SHOWERS ASSOCIATED WITH A
COLD FRONT MAY IMPACT THE TERMINALS ON WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 PM SATURDAY...NO CHANGES TO THE FORECAST OR CONDITIONS
OVER THE COASTAL WATERS SINCE LAST UPDATE. LIGHT EASTERLY FLOW
WITH SEAS IN THE 2 TO 3 FT RANGE PREVAIL. PREVIOUS DISCUSSIONS
FOLLOW:
LATEST OBS SHOW SEAS IN THE 2 TO 3 FT RANGE WITH A LIGHT EASTERLY
WIND. WINDS WILL BECOME MORE VARIABLE AS SURFACE RIDGE AXIS MOVES
OVERHEAD...OTHERWISE EXPECT LITTLE CHANGE IN SEA HEIGHT OVERNIGHT.
PREVIOUS DISCUSSION FOLLOWS:
WINDS WILL SHIFT AROUND TO THE E-SE THROUGH THIS EVENING AS TROUGH
JUST TO THE EAST OF LOCAL WATERS SHIFTS A LITTLE FARTHER WEST
THROUGH THIS EVENING BEFORE DISSIPATING BY DAYBREAK. OVERALL WEAK
HIGH PRESSURE WILL CONTINUE TO RIDGE INTO THE CAROLINAS AS IT
SHIFTS FARTHER OFF SHORE OVERNIGHT. THEREFORE EXPECT SFC WINDS TO
BECOME LIGHT WEST OR VARIABLE OVERNIGHT AROUND 5 TO 10 KTS. PATCHY
CU MAY CONTINUE TO MOVE OVER THE LOCAL WATERS OR DEVELOP ALONG THE
SFC TROUGH. CAN NOT RULE OUT A SPRINKLE AS TROUGH MOVES SLIGHTLY
CLOSER TO THE COAST THIS EVENING BEFORE WEAKENING. SLIGHTLY LONGER
PERIOD E-NE SWELL COMING AROUND THE HIGH PRESSURE WILL COMBINE
WITH LOCALLY MINIMAL WIND WAVE TO PRODUCE SEAS IN THE 2 TO 3 FT
RANGE MOST WATERS WITH A FEW 4 FOOTERS IN OUTER WATERS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...LIGHT AND VARIABLE WINDS SUNDAY WILL BECOME S
TO SW DURING THE AFTERNOON AND CONTINUE THROUGH MONDAY NIGHT.
SPEEDS OF 15 KT OR LESS ARE EXPECTED THROUGH THE PERIOD WITH SEAS
WILL OF 2 TO 4 FT.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 300 PM SATURDAY...TUESDAY THROUGH THURSDAY LOOKS UNSETTLED
AND ROUGH ON THE 0-20NM WATERS...PRIMARILY DUE TO A COLD FRONTAL
PASSAGE WEDNESDAY. PRE-FRONT SW WINDS LATE TUESDAY...AND POST-
FRONT NW WINDS LATE WED MAY BOTH REQUIRE AN ADVISORY...HENCE WE
MAY SEE AN ADVISORY FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT
BASED ON CURRENT TIMING AND STRENGTH OF THE APPROACHING FRONT.
ADDITIONALLY...WE MAY SEE A FEW TSTMS OVER THE WATERS WEDNESDAY.
THE SEA SPECTRUM TUE-THU WILL BE MARKED BY E WAVES 2-3 FEET AT 10
SECONDS...WITH GROWING SSW WIND-WAVES/BUILDING SOUTHERLY CHOP AND
SLOP. EXPECT A WIND-SHIFT TO NW WED AFTERNOON...CHANGING DIRECTION
OF THE SHORT PERIOD WAVES. THE COLD AIR ADVECTION BEHIND THE FRONT
WILL BRING NW WIND GUSTS TO 25-30 KNOTS WEDNESDAY AFTERNOON AND
NIGHT. THURSDAY OR THANKSGIVING DAY...A DAY OF IMPROVEMENT BUT A
BIT ROUGH IN THE MORNING FROM NNW WINDS...HIGHEST OFFSHORE. NEAR
SHORE CONDITIONS WILL IMPROVE THE QUICKEST EARLY THURSDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...REK
NEAR TERM...REK/RGZ
SHORT TERM...RAN
LONG TERM...MJC
AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
825 PM CST MON NOV 21 2011
.DISCUSSION...FORECAST CHALLENGE FOR UPDATE CONCERNS CLOUD
TRENDS/FOG AND TEMPERATURES.
WESTERN EDGE OF STRATUS SHIELD CONTINUES TO SPREAD WEST 10 TO 15KTS
AND CHALLENGE WILL BE HOW FAR WEST IT CAN GET. LOW LEVEL FLOW
REMAINS OUT OF THE SOUTHEAST TIL MORNING WHEN FLOW TURNS MORE S/SW.
CURRENT TRENDS WOULD HAVE STRATUS INTO SOUTHERN VALLEY AROUND 06Z
AND RUC HAS WEST EDGE ALONG A VALLEY CITY/GFK/ROX LINE AT 12Z. BASED
ON CURRENT TRENDS HARD TO ARGUE WITH THIS SOLUTION. CIGS WILL HAVE A
BIG IMPACT ON NOT ONLY AVIATION BUT TEMPERATURES. WILL ALREADY NEED
TO BUMP MINIMUMS UP ACROSS SE FA AND MAY HAVE TO GO FARTHER WEST
WITH WARMER TEMPERATURES. ALSO HAVE FOG WITH LOWER CIGS SO WILL NEED
TO MENTION THAT. REMAINDER OK.
&&
.AVIATION...IFR CIGS AND LIGHT FOG ACROSS EASTERN FA LOOKS LIKE IT
WILL CONTINUE TO SPREAD EAST AND COULD AFFECT FAR/GFK/TVF TAF SITES
BY MORNING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
VOELKER
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
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
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 / 80 40 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 67 81 43 73 43 / 80 40 0 0 0
NEW BRAUNFELS MUNI AIRPORT 68 81 43 74 44 / 70 30 0 0 0
BURNET MUNI AIRPORT 57 76 45 72 47 / 70 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 / 80 30 0 0 0
HONDO MUNI AIRPORT 63 83 42 76 42 / 50 10 0 0 0
SAN MARCOS MUNI AIRPORT 67 80 46 73 43 / 70 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 / 60 30 0 0 0
STINSON MUNI AIRPORT 69 84 48 76 46 / 60 30 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...11
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...32
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
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...NONE.
OK...NONE.
&&
$$
10/03
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
344 PM CST SUN NOV 20 2011
.UPDATE...
SEVERE THUNDERSTORM WATCH #893 UNTIL 05Z/11PM THIS EVENING FOR
AREAS FROM GRANBURY AND MARLIN...NORTHEAST TO BONHAM...PARIS AND
PALESTINE. UPDATES FORTH COMING. 75
&&
.PREV DISCUSSION... /ISSUED 157 PM CST SUN NOV 20 2011/
...SEVERE THUNDERSTORM POTENTIAL CONTINUES ACROSS PORTIONS OF NORTH
TEXAS LATER THIS AFTERNOON AND AGAIN ON MONDAY AFTERNOON AND
EVENING...
OVERALL...THIS AFTERNOONS FORECAST PACKAGE CONTINUES THE TRENDS
MENTIONED IN PREVIOUS FORECASTS OVER THE PAST SEVERAL DAYS. THE
COLD FRONT IS RUNNING SLIGHTLY AHEAD OF PREVIOUS TIMING...BUT
FAIRLY CLOSE TO THE NAM AND RUC MODEL SOLUTIONS. AT 145 PM IT
EXTENDS FROM PARIS TO CLEBURNE TO SOUTH OF COMANCHE.
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATER THIS
AFTERNOON THROUGH MID/LATE EVENING AS FORCING FOR ASCENT ARRIVES
FROM THE WEST AND HELPS WEAKEN THE STRONG CAP AROUND 860MB. VERY
MOIST AND UNSTABLE AIR AHEAD OF THE COLD FRONT WILL PRODUCE CAPES
500-1200 J/KG THIS EVENING AND 700-1400 J/KG ON MONDAY. BULK SHEAR
0-6KM WILL BE IN THE RANGE OF 40-60 KTS BOTH DAYS ALONG WITH
HELICITY VALUES GREAT THAN 200 M2/S2. AS PREVIOUSLY STATED...LARGE
HAIL WILL BE THE PRIMARY SEVERE THUNDERSTORM THREAT FOLLOWED BY
DAMAGING WINDS AND BRIEF ISOLATED TORNADOES. AREAS TO WATCH FOR
QUICK TORNADOGENESIS ARE...WHERE SURFACE WINDS ARE BACKED AND
THOSE CELLS THAT MOVE NEAR AND ALONG THE COLD FRONT. HAVE ADDED
SEVERE WORDING TO THE ZONE PACKAGE IN THIS RELEASE.
THE SYSTEM SHOULD MOVE OUT OF NORTH TEXAS LATE TUESDAY AFTERNOON
WITH FAIR WEATHER FOR WEDNESDAY AND THANKSGIVING DAY. OUR NEXT
SYSTEM WILL ARRIVE FRIDAY WITH ANOTHER ROUND OF THUNDERSTORMS AND
BENEFICIAL RAINFALL FOR NORTH TEXAS. THIS SYSTEM WILL MOVE RIGHT
ON THROUGH THE REGION AND SHOULD BE OUT OF NORTH TEXAS LATE FRIDAY
NIGHT. AFTERWARD...IT WILL BE DRY WITH SEASONAL TEMPERATURES OVER
THE WEEKEND. 75
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 60 73 60 69 45 / 50 80 90 40 10
WACO, TX 68 79 63 75 44 / 40 50 80 50 10
PARIS, TX 61 72 62 68 44 / 60 80 90 60 10
DENTON, TX 54 69 55 66 41 / 50 80 90 20 5
MCKINNEY, TX 59 71 59 67 43 / 50 80 90 50 10
DALLAS, TX 61 75 61 70 47 / 50 80 90 50 10
TERRELL, TX 64 76 65 70 45 / 50 60 90 50 10
CORSICANA, TX 67 79 66 75 47 / 50 40 80 70 10
TEMPLE, TX 68 79 65 77 46 / 30 30 70 60 10
MINERAL WELLS, TX 55 72 53 68 40 / 40 80 90 20 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25/75
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
247 PM CST SUN NOV 20 2011
.SHORT TERM...
MAIN FOCUS FOR THE SHORT TERM PERIOD IS THE IMPENDING WEST COAST
SYSTEM THAT WILL BRING CHANCES OF RAIN COMMENCING TOMORROW...AND
TAMPERING OFF TUESDAY MORNING.
THE PACIFIC UA LOW SYSTEM OF INTEREST WAS LOCATED OFF THE COAST OF
CENTRAL CALIFORNIA PER 20Z WATER VAPOR IMAGERY...AND PROGGED TO OPEN
UP AND EJECT QUICKLY ESE TO ACROSS THE DESERT SOUTHWEST MONDAY
MORNING...ACROSS THE SOUTH PLAINS MONDAY NIGHT AND EAST OF THE
REGION TUESDAY MORNING. THIS RELATIVELY QUICK TRAJECTORY IS BEING
HANDLED WELL BY THE NAM...GFS AND ECMWF SOLUTIONS...WITH PERHAPS THE
NAM BEING A TOUCH FASTER THAN THE LATTER MODELS. 20Z SFC ANALYSIS
DISPLAYED A COLD FRONT THAT SURGED SOUTH ACROSS THE CWA EARLIER THIS
MORNING...AND WAS SPATIALLY DISTRIBUTED FROM A NEAR PINE SPRINGS TO
FORT STOCKTON TO BRADY LINE. THUS LEAVING TEMPS IN THE 40S AND 50S
AND DEWPOINTS IN THE 20S AND 30S IN ITS WAKE. THIS PLACEMENT OF THE
SAID FRONT IS FARTHER SOUTH THAN WHAT MODELS PREDICTED 24 HOURS AGO.
THE GFS AND ECMWF ARE ONLY SLIGHTLY SIMILAR TO THE NAM IN REGARD TO
THE FRONT NOT BEING QUITE AS FAR SOUTH...HENCE THE CURRENT PLACEMENT
OF THE FRONT IS NOT HANDLED WELL BY EITHER AFOREMENTIONED SOLUTION
PER SE. HENCE...THE NAM AND RUC MODELS DISPLAY THE FRONT TRANSLATING
A BIT FARTHER SOUTH TONIGHT /THE RUC IS MOST AGGRESSIVE WITH THIS
POSSIBILITY/ BUT THE NAM AND TO A LESSER EXTENT THE GFS HAS A WARM
TONGUE OOZING IN ACROSS THE FAR SOUTHWESTERN ZONES.
IF FOLLOWING THE NAM SOLUTION WITH A SLIGHT RELIANCE ON THE GFS
SOLUTION...THE SUB-TROPICAL FETCH OF MOISTURE WILL CONTINUE TO SPILL
ACROSS THE SOUTH PLAINS AND THUS HIGH LEVEL CLOUDINESS WILL PREVAIL
THE REST OF TODAY AND TONIGHT. A 1025 SFC RIDGE WILL SETTLE IN NE OF
THE REGION AND INDUCE GENERALLY LIGHT EAST TO SOUTHEAST/UPSLOPE SFC
WINDS TONIGHT. AS A RESULT...LOW LEVEL MOISTURE WILL INCREASE AS
MODEL SOUNDINGS DISPLAYED PROGGED PWATS NEARING 1.00 INCH
PARTICULARLY ACROSS THE CENTRAL TO EASTERN SOUTH PLAINS. THE
SYNOPTIC LIFT IS NOT STRONG AT THIS POINT...BUT CURRENT THINKING IS
THAT LOW LEVEL STRATUS WILL DEVELOP FROM SOUTH TO NORTH WITH PERHAPS
ISENTROPIC UPGLIDE BEING ENOUGH TO INDUCE LIGHT DRIZZLE ACROSS THE
AFOREMENTIONED AREAS EARLY TOMORROW MORNING. AOA 12Z...INDICATIONS
OF LOCALIZED PATCHY FOG MAY DEVELOP AND LAST THROUGH MID-MORNING
ACROSS PORTIONS OF THE CWA...AS THE SYSTEM NEARS THE WESTERN FRINGES
OF THE SOUTH PLAINS. BY EARLY AFTERNOON...SYNOPTIC LIFT HAS
INCREASED AND MUCAPE VALUES IS ANTICIPATED TO NEAR 1000 J/KG
ESPECIALLY ACROSS EASTERN ZONES. THUS...ADEQUATE MUCAPE AND 0-6 KM
SHEAR VALUES NEARING 70 KTS MAY PROMOTE ISOLATED STRONG TO POSSIBLY
SEVERE THUNDERSTORMS WHERE HAIL IS THE PRIMARY THREAT...ACROSS
EASTERN ZONES DURING THE EARLY TO MID AFTERNOON. THE 15Z-00Z
TIME-FRAME APPEARS TO BE WHEN THE SYNOPTIC LIFT IS AT ITS
BEST...WITH A NOTICEABLE DECLINATION THEREAFTER. IT IS ALSO DURING
THE AFOREMENTIONED TIME-FRAME WHERE THE FRONT IS ANTICIPATED TO
RETREAT NORTH TO NEAR THE SOUTHEASTERN ZONES BEFORE THE PACIFIC
FRONT SWEEPS IN FROM WEST TO EAST...DRY SLOTTING THE REGION LATE
MONDAY NIGHT/EARLY TUESDAY MORNING. THUS THE OVERALL TREND APPEARS
TO BE LIGHT DRIZZLE EARLY MONDAY MORNING FOLLOWED BY INCREASING RAIN
CHANCES WITH HIGHEST POPS DISPLAYED 18Z-00Z ACROSS THE
EAST...COINCIDING WITH BEST SYNOPTIC LIFT AS THE SYSTEM COMMENCES TO
MOVE ACROSS THE REGION. THEREAFTER...PRECIP WILL DECLINE FROM WEST
TO EAST BY TUESDAY 12Z.
TEMPS OVER NIGHT TONIGHT WILL BE RELATIVELY MILD WITH MID TO UPPER
30S NORTH TO LOWER TO MID 40S SOUTH EXPECTED....AS HIGH-LEVEL
CLOUDINESS ENSUE AND EVENTUALLY LOW LEVEL STRATUS DEVELOPS. TEMPS
TOMORROW COULD BE A BIT TRICKY DEPENDING ON IF THE PACIFIC FRONT
MOVING IN FROM THE WEST DRY SLOTS THE AREA QUICKER THAN ANTICIPATED.
HOWEVER...WILL LEAN TOWARDS A RANGE OF UPPER 40S TO LOWER 50S NE TO
LOWER 60S SW AS HINTED AT BY MOS GUIDANCE.
&&
.LONG TERM...
TUES 12Z...THE COLD FRONT WILL BE NEARLY IF NOT ALL THE WAY THRU THE
FA...ALLOWING THE AREA TO DRY OUT. BY WED 06Z...SKIES WILL BE CLEAR
WITH LITTLE RESIDUAL MOISTURE LEFT IN THE LOW LVLS.
THEREFORE...EXPECT TEMPS TO FALL SOME OVERNIGHT ACROSS THE AREA.
THOUGH AS SRLY SFC FLOW RETURNS...THE SHORTWAVE RIDGING ALSO MOVES
INTO THE AREA. THIS WILL ALLOW FOR A BRIEF WARMING TREND AHEAD THE
NEXT UL TROF EXPECTED TO MOVE INTO THE REGION ON TURKEY DAY. THIS
TROF IS PROGGED TO BE FAIRLY LOW AMPLITUDE AS IT MOVE ACROSS THE FA
PREVENTING MUCH IN THE WAY OF MOISTURE RETURN. THEREFORE...WILL
CONTINUE THE DRY EXTENDED FORECAST. ALSO...WINDS ASSOCIATED WITH
THIS SYSTEM LOOK FAIRLY ROBUST /AOA 40KTS AT 850/ AND GIVEN DRY
CONDITIONS THERE CONTINUE TO BE SOME FIRE WEATHER CONCERNS. THAT
BEING SAID GIVEN THE TIMING CURRENTLY PROGGED THESE WINDS WILL RAMP
UP IN THE COLD AIR AND LATE IN THE DAY AS THE TROF PUSHES THRU THE
REGION. ALSO...AS THE TROF EXITS THE REGION A SECOND SURGE OF ENERGY
TRAVERSES THE TROF PUSHING A STRONG COLD FRONT THRU THE AREA
OVERNIGHT FRI.
MEADOWS
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 36 55 34 60 31 / 10 30 20 0 0
TULIA 35 51 36 60 32 / 20 50 20 0 0
PLAINVIEW 36 52 37 61 33 / 20 50 20 0 0
LEVELLAND 41 60 40 63 34 / 20 30 10 0 0
LUBBOCK 41 54 40 63 34 / 20 40 20 0 0
DENVER CITY 44 63 42 64 36 / 20 20 10 0 0
BROWNFIELD 43 62 41 63 36 / 20 30 10 0 0
CHILDRESS 36 49 39 65 36 / 20 70 40 0 0
SPUR 42 50 41 64 37 / 20 60 20 0 0
ASPERMONT 45 53 44 63 37 / 20 70 40 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29/40
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
157 PM CST SUN NOV 20 2011
.DISCUSSION...
...SEVERE THUNDERSTORM POTENTIAL CONTINUES ACROSS PORTIONS OF NORTH
TEXAS LATER THIS AFTERNOON AND AGAIN ON MONDAY AFTERNOON AND
EVENING...
OVERALL...THIS AFTERNOONS FORECAST PACKAGE CONTINUES THE TRENDS
MENTIONED IN PREVIOUS FORECASTS OVER THE PAST SEVERAL DAYS. THE
COLD FRONT IS RUNNING SLIGHTLY AHEAD OF PREVIOUS TIMING...BUT
FAIRLY CLOSE TO THE NAM AND RUC MODEL SOLUTIONS. AT 145 PM IT
EXTENDS FROM PARIS TO CLEBURNE TO SOUTH OF COMANCHE.
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATER THIS
AFTERNOON THROUGH MID/LATE EVENING AS FORCING FOR ASCENT ARRIVES
FROM THE WEST AND HELPS WEAKEN THE STRONG CAP AROUND 860MB. VERY
MOIST AND UNSTABLE AIR AHEAD OF THE COLD FRONT WILL PRODUCE CAPES
500-1200 J/KG THIS EVENING AND 700-1400 J/KG ON MONDAY. BULK SHEAR
0-6KM WILL BE IN THE RANGE OF 40-60 KTS BOTH DAYS ALONG WITH
HELICITY VALUES GREAT THAN 200 M2/S2. AS PREVIOUSLY STATED...LARGE
HAIL WILL BE THE PRIMARY SEVERE THUNDERSTORM THREAT FOLLOWED BY
DAMAGING WINDS AND BRIEF ISOLATED TORNADOES. AREAS TO WATCH FOR
QUICK TORNADOGENESIS ARE...WHERE SURFACE WINDS ARE BACKED AND
THOSE CELLS THAT MOVE NEAR AND ALONG THE COLD FRONT. HAVE ADDED
SEVERE WORDING TO THE ZONE PACKAGE IN THIS RELEASE.
THE SYSTEM SHOULD MOVE OUT OF NORTH TEXAS LATE TUESDAY AFTERNOON
WITH FAIR WEATHER FOR WEDNESDAY AND THANKSGIVING DAY. OUR NEXT
SYSTEM WILL ARRIVE FRIDAY WITH ANOTHER ROUND OF THUNDERSTORMS AND
BENEFICIAL RAINFALL FOR NORTH TEXAS. THIS SYSTEM WILL MOVE RIGHT
ON THROUGH THE REGION AND SHOULD BE OUT OF NORTH TEXAS LATE FRIDAY
NIGHT. AFTERWARD...IT WILL BE DRY WITH SEASONAL TEMPERATURES OVER
THE WEEKEND. 75
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 60 73 60 69 45 / 50 80 90 40 10
WACO, TX 68 79 63 75 44 / 40 50 80 50 10
PARIS, TX 61 72 62 68 44 / 60 80 90 60 10
DENTON, TX 54 69 55 66 41 / 50 80 90 20 5
MCKINNEY, TX 59 71 59 67 43 / 50 80 90 50 10
DALLAS, TX 61 75 61 70 47 / 50 80 90 50 10
TERRELL, TX 64 76 65 70 45 / 50 60 90 50 10
CORSICANA, TX 67 79 66 75 47 / 50 40 80 70 10
TEMPLE, TX 68 79 65 77 46 / 30 30 70 60 10
MINERAL WELLS, TX 55 72 53 68 40 / 40 80 90 20 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25/75
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1205 PM CST SUN NOV 20 2011
.AVIATION...
/18Z TAFS/
CONCERNS...CIGS AND TIMING OF PRECIP.
AT ISSUANCE TIME...FRONT WAS APPROACHING LOVE FIELD...PAST
TERMINAL AT VALID TIME OF 18Z TAFDAL. AFW NOW REPORTING IFR
CIGS...BUT EXPECT POSTFRONTAL CONDITIONS TO BE DOMINATED BY MVFR
CONDITIONS. CONVECTIVE INITIATION THIS AFTERNOON NEAR THE SURFACE
BOUNDARY WILL LIKELY REMAIN SOUTHEAST OF METRO TAF SITES. THUNDER
MAY SPREAD NORTH OF THE BOUNDARY THIS EVENING AS LLJ INITIATES.
HAVE REDUCED MENTION TO CB UNTIL TIME FRAME CAN BE BETTER
REPRESENTED.
WACO WILL EXPERIENCE VEERING WINDS THIS AFTERNOON...BUT WILL
REMAIN SOUTH OF THE BOUNDARY. SOME SHOWERS UPSTREAM OVER HILL
COUNTRY. WILL MONITOR POTENTIAL FOR CONVECTIVE DEVELOPMENT THIS
AFTERNOON...BUT CONFIDENCE IS TOO LOW TO INCLUDE SPECIFIC MENTION
WITH 18Z ISSUANCE.
MONDAY...IFR CONDITIONS WITH SHRA (OCCASIONAL TSRA).
25
&&
.UPDATE...
COLD FRONT HAS MOVED INTO THE WESTERN METROPLEX AS OF 10 AM PER
SURFACE OBS AND RADAR SIGNATURE...WHICH IS MORE IN LINE WITH THE
NAM AND RUC MODELS. HAVE ADJUSTED GRIDS TO REFLECT ITS CURRENT
POSITION AND A SLOW PROGRESSION TO THE SOUTHEAST THROUGH MID
AFTERNOON. MAY REACH A CANTON TO LAMPASAS LINE BY 6 PM THIS
EVENING. MAX TEMPS...HOURLY TEMP...DEWPOINT AND WIND GRIDS WERE
ALSO ADJUSTED THROUGH MID AFTERNOON.
BRIEF LOOK AT THE LATEST GFS AND THE EARLIER NAM/RUC SERIES SHOW A
DIFFERENCE IN THE FRONTAL POSITION OVER THE NEXT 24 HOURS...WHICH
RESULTS IN A LOCATION DIFFERENCE IN WHERE CONVECTION/RAIN WILL
OCCUR THIS AFTERNOON AND OVERNIGHT. SINCE THE NAM/RUC HAVE THE
BEST INITIALIZATION OF THE FRONT...WILL CONTINUE TO FAVOR THEIR
PRECIPITATION PROCESS ALONG AND AHEAD OF THE THE FRONT THIS
AFTERNOON AND TONIGHT. THE PREVIOUS FORECAST HAD THIS APPROACH
BUILT INTO IT...THUS DO NOT FEEL A NEED TO ADJUST TIMING OR
LOCATIONS OF PRECIPITATION IN THIS UPDATE. EVEN THE FORECAST FOR
MONDAY THROUGH MONDAY NIGHT SEEMS ON TRACK WITH THIS MORNING
MODEL RUNS. ONE THING THAT COULD CHANGE IN THE AFTERNOON PACKAGE
WOULD BE THE TIMING FOR ENDING THE RAIN WEST TO EAST ON TUESDAY.
75
&&
.PREV DISCUSSION... /ISSUED 508 AM CST SUN NOV 20 2011/
EARLY MORNING WATER VAPOR IMAGERY DEPICTED SHORTWAVE TROUGHS OVER
THE NORTHERN CONUS ROCKIES...OVER THE BAJA PENINSULA AND JUST OFF
THE NORTHERN CA COAST. A PLUME OF TROPICAL PACIFIC MOISTURE WAS
STREAMING OVER THE SOUTHERN ROCKIES AND OVER THE SOUTHERN PLAINS.
A COLD FRONT CHARACTERIZED BY A STRONG LOW LEVEL BAROCLINIC ZONE
REMAINED JUST TO THE NORTHWEST OF THE CWA AS OF 09Z...AND WAS
LOCATED APPROXIMATELY ALONG AN ARDMORE TO THROCKMORTON LINE.
ALTHOUGH THE FRONT HAS SLOWED DOWN SIGNIFICANTLY OVERNIGHT...IT
CONTINUES TO PUSH SOUTHEAST EARLY THIS MORNING AND WILL LIKELY
ENTER THE FAR NORTHWESTERN COUNTIES OF OUR FORECAST AREA BY 12Z.
TEMPERATURES FALL RAPIDLY BEHIND/NORTH OF THE FRONT WITH A 09Z
TEMPERATURE OF 61 AT BOWIE AND ONLY 46 AT WICHITA FALLS.
TODAY AND TONIGHT...THE BAJA SHORTWAVE TROUGH IS EXPECTED TO MOVE
QUICKLY NORTHEAST DURING THE DAY TODAY AND IS EXPECTED TO BE
LOCATED OVER THE CENTRAL PLAINS BY EARLY THIS EVENING. THIS FAST
MOVING BUT SOMEWHAT WEAK TROUGH WILL SPREAD SOME LARGE SCALE
FORCING FOR ASCENT OVER THE SOUTHERN PLAINS TODAY AHEAD OF THE
COLD FRONT. THE TROUGH ITSELF IS EXPECTED TO REMAIN WELL TO THE
NORTH OF THE CWA...SO IT WILL LIKELY NOT PLAY A SIGNIFICANT ROLE IN
PRECIPITATION CHANCES DURING THE PERIOD. TODAY/S PRIMARY FORECAST
CHALLENGE IS WITH REGARDS TO CONVECTIVE INITIATION ALONG THE COLD
FRONT...WHICH IS EXPECTED TO STALL OUT SOMEWHERE OVER NORTH TX BY
EARLY THIS AFTERNOON.
ONE CHALLENGE REGARDING CONVECTIVE INITIATION THIS AFTERNOON IS
FORECASTING WHERE THE FRONT WILL STALL OUT. 00 AND 06Z GUIDANCE
HAS FAILED TO COME UP WITH A CONSENSUS POSITION OF THE STALLED OUT
FRONT. THE COARSER RESOLUTION GUIDANCE INDICATES THAT THE FRONT
WILL STALL OUT NEAR THE DFW METROPLEX WHILE THE HIGHER RESOLUTION
GUIDANCE INDICATES THAT THE FRONT WILL MAKE IT AS FAR SOUTHEAST AS
A SULPHUR SPRINGS TO HILLSBORO TO GOLDTHWAITE LINE. NEITHER
SOLUTION INITIALIZED THE CURRENT POSITION OF THE FRONT
PERFECTLY...SO OPTED TO GO WITH A BLEND AND JUST PUSHED THE FRONT
FURTHER SOUTHEAST THAN PREVIOUS FORECAST HAD INDICATED FOR THIS
AFTERNOON. THINK THAT BEST PRECIPITATION CHANCES WILL REMAIN ALONG
THE FRONTAL BOUNDARY FOR THIS AFTERNOON...SO ADJUSTED POPS
ACCORDINGLY TAKING THE HIGHER AXIS OF 40/50 POPS A BIT FURTHER
SOUTHEAST FOR THIS AFTERNOON AND THIS EVENING.
THE OTHER CHALLENGE REGARDING CONVECTIVE INITIATION TODAY IS
IDENTIFYING A STRONG FORCING MECHANISM. THE STALLED OUT COLD FRONT
IS THE OBVIOUS FEATURE IN PLAY BUT THE LIMITING FACTOR REGARDING
FORCING ALONG THE FRONT IS THE FACT THAT IT IS EXPECTED TO BE
STATIONARY BY THIS AFTERNOON. WITHOUT MOVEMENT THERE WILL NO
FORCED CONVECTION OUT AHEAD OF THE FRONT ASSOCIATED WITH DYNAMIC
PRESSURE PERTURBATIONS. THE PRIMARY FORCING MECHANISM ASSOCIATED
WITH THE FRONT THEN APPEARS TO BE FRONTOGENESIS WHICH IS TYPICALLY
MAXIMIZED BEHIND THE LEADING EDGE OF THE SURFACE FRONT. MOST SREF
ENSEMBLE MEMBERS DEPICT A LOW LEVEL CAPPING INVERSION IN PLACE
OVER NORTH TX THIS AFTERNOON. WHILE WE WILL HAVE SOME MODEST LOW
LEVEL WARM AIR ADVECTION SOUTH OF THE FRONTAL BOUNDARY TODAY THE
PRESENCE OF THIS CAP /ASSUMING IT EXISTS/ SHOULD LIMIT THE
INITIATION OF TSTM ACTIVITY TO THE IMMEDIATE VICINITY OF THE FRONT.
WITH THIS IN MIND NARROWED THE BAND 30 TO 50 POPS TODAY TO THOSE
LOCATIONS WHERE THE FRONT MAY REASONABLY STALL OUT. DID NOT GO ANY
HIGHER THAN 50 POPS IN THE CWA THRU 00Z AS ALL CONVECTION ALLOWING
GUIDANCE KEEPS TSTM ACTIVITY OUT OF NORTH TX THIS AFTERNOON WHILE
ALL OTHER GUIDANCE INDICATES DEVELOPING CONVECTION ALONG THE FRONT
BETWEEN 21 TO 00Z. THE LACK OF LARGE SCALE FORCING FOR ASCENT
TENDS TO FAVOR A SLOW LIFTING OR STRONGER CAP SO WILL REMAIN
CAUTIOUS WITH REGARDS TO POPS UNTIL 12Z UPPER AIR DATA COMES IN AS
WELL AS AIRCRAFT DATA SOUNDING DATA LATER THIS MORNING.
IF TSTMS ARE ABLE TO INITIATE ALONG THE FRONT THIS
AFTERNOON...THERE IS A CHANCE THAT THEY WILL BECOME SEVERE. SREF
MEAN SURFACE BASED CAPE VALUES ARE AROUND 1000 J/KG SOUTH OF THE
FRONT TODAY AND ALL OPERATIONAL GUIDANCE ADVERTISES AT LEAST THIS
MUCH POTENTIAL INSTABILITY. DEEP LAYER SHEAR IS EXPECTED TO BE
AROUND 40 TO 50 KTS THIS AFTERNOON WHICH WOULD SUPPORT AN
ORGANIZED CONVECTIVE MODE. DEW POINT VALUES THIS MORNING ARE
EXCEPTIONALLY HIGH FOR NOVEMBER...WITH DEW POINTS IN THE LOWER 70S
OBSERVED FROM HEARNE SOUTHEAST TO THE GULF COAST. WE WOULD NEED
JUST A FEW BREAKS IN THE LOW CLOUD COVER THIS AFTERNOON TO SEE
CAPE VALUES JUMP UP ABOVE 1000 J/KG. BECAUSE CLOUDS ARE EXPECTED
TO HOLD IN FOR MUCH OF THE DAY...OVERALL TORNADO POTENTIAL IS LOW
DUE TO POOR LOW LEVEL LAPSE RATES LIMITING VORTEX STRETCHING
POTENTIAL. LARGE HAIL LOOKS TO BE THE PRIMARY THREAT IN THIS
ENVIRONMENT WITH THE DAMAGING WIND AND TORNADO POTENTIAL PERKING
UP IN ANY AREAS THAT SEE A FEW HOURS OF SUNSHINE TODAY. WOULD
EXPECT A LARGELY LINEAR/QLCS STORM MODE AS DEEP LAYER SHEAR
VECTORS ARE EXPECTED TO BE NEARLY PARALLEL TO THE STATIONARY
FRONT.
TSTM ACTIVITY IS EXPECTED TO INCREASE IN COVERAGE TONIGHT AS THE
SHALLOW COLD FRONT INTERACTS WITH THE DEVELOPING LOW LEVEL JET.
THE LOW LEVEL JET IS EXPECTED TO RAMP UP IN ADVANCE OF THE NEXT
APPROACHING SHORTWAVE TROUGH WHICH IS MUCH STRONGER THAN THE BAJA
TROUGH. THE COLD FRONT WILL EFFECTIVELY STEEPEN LOW LEVEL
ISENTROPIC SURFACES ALLOWING FOR SIGNIFICANT ISENTROPIC LIFT
AFTER MIDNIGHT AS THE LLJ RIDES OVER THIS BOUNDARY. THIS FORCING
IS MUCH MORE BROAD THAN THE NARROW FRONTOGENETIC FORCING ALONG THE
FRONT...SO WENT AHEAD AND SPREAD POPS OUT OVER MUCH OF NORTH TX
LATE OVERNIGHT AND THRU MONDAY MORNING AS THE FRONT GRADUALLY
LIFTS BACK NORTH MONDAY MORNING. STORMS SUNDAY NIGHT WILL LIKELY
BE ELEVATED IN NATURE AND SHOULD ONLY POSE A LOWER END SEVERE HAIL
THREAT.
MONDAY AFTERNOON THRU TUESDAY...THE TROUGH THAT CURRENTLY RESIDES
OFF THE NORTHERN CA COAST WILL MOVE THRU THE SOUTHERN PLAINS LATE
MONDAY AFTERNOON THRU THE EVENING HRS. THIS SHOULD RESULT IN
WIDESPREAD TSTM ACTIVITY THRU MUCH OF THE REGION DURING THIS
PERIOD. WITH STRONG FORCING FOR ASCENT ASSOCIATED WITH THE
POWERFUL UPPER TROUGH WENT AHEAD WITH SREF SUGGESTED POPS DUE TO
THE STRONG SYNOPTIC SIGNALS IN PLACE.
FOR OUR CWA...MOST CONFIDENT IN TSTM ACTIVITY NEAR ANY FRONTAL
BOUNDARY DURING THE PERIOD SO HAVE PLACED 80 POPS OR HIGHER NEAR
THE EXPECTED POSITION OF SYNOPTIC FRONTS. ANY STORMS THAT DEVELOP
MONDAY AFTERNOON OR EVENING WILL HAVE THE POTENTIAL TO BECOME
SEVERE WITH DEEP MOISTURE AND EVEN STRONGER SHEAR IN PLACE THAN
WHAT IS EXPECTED FOR SUNDAY AFTERNOON. PRIMARY SEVERE
THUNDERSTORM HAZARDS WILL BE DEPENDENT UPON WHERE FRONTAL
BOUNDARIES LIE AND WHERE STORMS DEVELOP. WHILE THE CONFIDENCE OF
TSTMS OCCURRING IS HIGH...THE CONFIDENCE REGARDING THESE DETAILS
IS FAIRLY LOW AT THIS TIME.
STORMS THAT DEVELOP ALONG THE RETREATING FRONTAL BOUNDARY/WARM
FRONT MONDAY AFTERNOON WILL TEND TO BE MORE QUASI-LINEAR IN
NATURE AS DEEP LAYER SHEAR REMAINS NEARLY PARALLEL TO THIS
BOUNDARY WITH LITTLE IN THE WAY OF A CAP IN PLACE. HEAVY RAINFALL
POTENTIAL IS CERTAINLY THERE DUE TO THE POTENTIAL FOR STORMS TO
TRAIN OVER ONE ANOTHER/S TRACK NEAR THE WARM FRONT. A MORE
DISCRETE MODE MAY BE EXPECTED ALONG THE DRYLINE MONDAY
AFTERNOON...HOWEVER THIS BOUNDARY IS EXPECTED TO BE PLACED WELL
WEST OF THE CWA. IT IS POSSIBLE FOR DISCRETE STORMS/SUPERCELLS TO
DEVELOP OUT WEST AND THEN MOVE EAST INTO THE CWA LATE MONDAY
AFTERNOON. STORMS WILL INCREASE IN COVERAGE MONDAY EVENING AS THE
ENTIRE STORM SYSTEM BEGINS TO MOVE NORTHEAST AND A COLD FRONT
MOVES THRU THE AREA ONCE AGAIN. UNLIKE TODAY...THIS FRONT IS
EXPECTED TO MOVE ALL THE WAY THRU NORTH TX BY TUESDAY MORNING.
FORCING ALONG THE MOVING COLD FRONT WILL ONCE AGAIN PROMOTE
QLCS/MULTICELL ACTIVITY DEPENDING ON POTENTIAL INSTABILITY AFTER
SUNSET.
FOR MONDAY AFTERNOON...STORMS NEAR THE WARM FRONT WILL CONTINUE TO
HAVE A PRIMARILY LARGE HAIL SEVERE TSTM THREAT WITH ENHANCED
DAMAGING WIND AND TORNADO POTENTIAL FOR ANY AREAS THAT RECEIVE A
FEW HRS OF SUNSHINE. IF DISCRETE SUPERCELLS ARE ABLE TO ORGANIZE
TO OUR WEST...THESE WOULD HAVE A MORE PROMINENT TORNADO AND
DAMAGING WIND THREAT AS WELL AS AN ATTENDANT LARGE HAIL. UNLESS
THIS ACTIVITY IS ABLE TO MOVE INTO THE CWA OR DEVELOP IN THE WAA
REGIME AWAY FROM FRONTAL BOUNDARIES BEFORE SUNSET...THE OVERALL
TORNADO POTENTIAL MAY BE LOW MONDAY AFTERNOON AND EVENING. THESE
DETAILS WILL BE DIFFICULT TO RESOLVE UNTIL TOMORROW WHEN
CONFIDENCE IS HIGHER ON THE PLACEMENT OF SYNOPTIC FEATURES.
EXTENDED...DID NOT MAKE SIGNIFICANT CHANGES TO THE EXTENDED.
BEHIND THE COLD FRONT WE SHOULD SEE A FEW DAYS OF DRY WEATHER
AHEAD OF THE NEXT POWERFUL SHORTWAVE TROUGH. THIS TROUGH IS
EXPECTED TO MOVE INTO THE SOUTHERN PLAINS FRIDAY AFTERNOON OR
FRIDAY NIGHT. 00Z GUIDANCE WAS IN FAIRLY GOOD AGREEMENT ON THE
TIMING OF THIS FEATURE...AND POPS WILL NEED TO BE INCREASED IF
THIS CONSENSUS REMAINS IN TACT MOVING FORWARD. FOR NOW HAVE BROAD
BRUSHED 20 AND 30 POPS FOR FRIDAY AND FRIDAY NIGHT. CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 62 75 61 70 46 / 50 80 90 50 10
WACO, TX 68 80 64 76 45 / 40 50 80 60 10
PARIS, TX 63 74 62 69 45 / 60 80 90 80 10
DENTON, TX 55 71 56 67 41 / 50 80 90 40 5
MCKINNEY, TX 60 74 60 69 43 / 50 80 90 50 10
DALLAS, TX 64 77 63 70 48 / 50 80 90 50 10
TERRELL, TX 67 79 65 72 46 / 50 60 90 70 10
CORSICANA, TX 68 81 68 75 48 / 50 40 80 80 10
TEMPLE, TX 68 82 66 78 46 / 30 30 70 70 10
MINERAL WELLS, TX 55 72 53 69 40 / 40 80 90 30 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25/75
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1048 AM CST SUN NOV 20 2011
.UPDATE...
COLD FRONT HAS MOVED INTO THE WESTERN METROPLEX AS OF 10 AM PER
SURFACE OBS AND RADAR SIGNATURE...WHICH IS MORE IN LINE WITH THE
NAM AND RUC MODELS. HAVE ADJUSTED GRIDS TO REFLECT ITS CURRENT
POSITION AND A SLOW PROGRESSION TO THE SOUTHEAST THROUGH MID
AFTERNOON. MAY REACH A CANTON TO LAMPASAS LINE BY 6 PM THIS
EVENING. MAX TEMPS...HOURLY TEMP...DEWPOINT AND WIND GRIDS WERE
ALSO ADJUSTED THROUGH MID AFTERNOON.
BRIEF LOOK AT THE LATEST GFS AND THE EARLIER NAM/RUC SERIES SHOW A
DIFFERENCE IN THE FRONTAL POSITION OVER THE NEXT 24 HOURS...WHICH
RESULTS IN A LOCATION DIFFERENCE IN WHERE CONVECTION/RAIN WILL
OCCUR THIS AFTERNOON AND OVERNIGHT. SINCE THE NAM/RUC HAVE THE
BEST INITIALIZATION OF THE FRONT...WILL CONTINUE TO FAVOR THEIR
PRECIPITATION PROCESS ALONG AND AHEAD OF THE THE FRONT THIS
AFTERNOON AND TONIGHT. THE PREVIOUS FORECAST HAD THIS APPROACH
BUILT INTO IT...THUS DO NOT FEEL A NEED TO ADJUST TIMING OR
LOCATIONS OF PRECIPITATION IN THIS UPDATE. EVEN THE FORECAST FOR
MONDAY THROUGH MONDAY NIGHT SEEMS ON TRACK WITH THIS MORNING
MODEL RUNS. ONE THING THAT COULD CHANGE IN THE AFTERNOON PACKAGE
WOULD BE THE TIMING FOR ENDING THE RAIN WEST TO EAST ON TUESDAY.
75
&&
.AVIATION...
LOW CLOUDS WILL BE PRESENT THROUGH MOST OF THIS FORECAST CYCLE AS A
COLD FRONT ENCROACHES AND THEN STALLS NEAR THE METROPLEX TODAY.
ONE OF THE MANY CHALLENGES TO THIS FORECAST IS HOW FAR SOUTHEAST
THE FRONT WILL MAKE IT BEFORE COMING TO REST...THEN WHEN IT WILL
LIFT NORTH AS THE WEST COAST UPPER LOW DEEPENS AND APPROACHES THE
REGION. A MODEL BLEND SEEMS MOST LOGICAL AT THIS TIME FOR FRONTAL
POSITION AND RESPECTIVE WIND FORECAST AT THE AREA TERMINALS. NAM
AND RUC ARE WELL AHEAD OF THE GFS ON SOUTHEASTWARD MOVEMENT OF THE
BOUNDARY...BUT APPEAR TO HAVE INITIALIZED ITS POSITION TOO FAR
SOUTHEAST. GFS JUST SEEMS TOO SLOW ON THE FORWARD PROGRESS. FOR
THIS FORECAST SET...WILL CONTINUE WITH THE IFR CIGS UNTIL MID-LATE
MORNING WITH VEERING WINDS AHEAD OF THE FRONT. MVFR CONDITIONS
THEN EXPECTED THE REST OF THE DAY AND WILL ADVERTISE FROPA AT OR
JUST BEFORE NOON LOCAL FOR THE METRO AREA TAF SITES. WILL INDICATE
VEERING WINDS AT ACT BUT THINK THE BOUNDARY MAY BECOME STATIONARY
BEFORE REACHING THE ACT TERMINAL. FRONT WILL THEN LIFT NORTH
TOMORROW MORNING BRINGING SE WINDS AREA-WIDE.
WILL INCLUDE VCSH BEGINNING MIDDAY TODAY. FEEL THE BEST CHANCES
FOR THUNDERSTORMS WILL BE TONIGHT AS OVERALL ASCENT INCREASES AND
THE FRONT PROVIDES FOCUS FOR DEVELOPMENT. CB IS POSSIBLE LATE THIS
AFTERNOON...BUT WITH THE PRESENCE OF A CAP THROUGH MOST OF THE DAY
WILL HOLD OFF MENTION OF CB UNTIL 21/02Z WHEN LOW LEVEL JET BEGINS
TO MATERIALIZE AND ELEVATED TS BECOME MORE LIKELY. 30
&&
.PREV DISCUSSION... /ISSUED 508 AM CST SUN NOV 20 2011/
EARLY MORNING WATER VAPOR IMAGERY DEPICTED SHORTWAVE TROUGHS OVER
THE NORTHERN CONUS ROCKIES...OVER THE BAJA PENINSULA AND JUST OFF
THE NORTHERN CA COAST. A PLUME OF TROPICAL PACIFIC MOISTURE WAS
STREAMING OVER THE SOUTHERN ROCKIES AND OVER THE SOUTHERN PLAINS.
A COLD FRONT CHARACTERIZED BY A STRONG LOW LEVEL BAROCLINIC ZONE
REMAINED JUST TO THE NORTHWEST OF THE CWA AS OF 09Z...AND WAS
LOCATED APPROXIMATELY ALONG AN ARDMORE TO THROCKMORTON LINE.
ALTHOUGH THE FRONT HAS SLOWED DOWN SIGNIFICANTLY OVERNIGHT...IT
CONTINUES TO PUSH SOUTHEAST EARLY THIS MORNING AND WILL LIKELY
ENTER THE FAR NORTHWESTERN COUNTIES OF OUR FORECAST AREA BY 12Z.
TEMPERATURES FALL RAPIDLY BEHIND/NORTH OF THE FRONT WITH A 09Z
TEMPERATURE OF 61 AT BOWIE AND ONLY 46 AT WICHITA FALLS.
TODAY AND TONIGHT...THE BAJA SHORTWAVE TROUGH IS EXPECTED TO MOVE
QUICKLY NORTHEAST DURING THE DAY TODAY AND IS EXPECTED TO BE
LOCATED OVER THE CENTRAL PLAINS BY EARLY THIS EVENING. THIS FAST
MOVING BUT SOMEWHAT WEAK TROUGH WILL SPREAD SOME LARGE SCALE
FORCING FOR ASCENT OVER THE SOUTHERN PLAINS TODAY AHEAD OF THE
COLD FRONT. THE TROUGH ITSELF IS EXPECTED TO REMAIN WELL TO THE
NORTH OF THE CWA...SO IT WILL LIKELY NOT PLAY A SIGNIFICANT ROLE IN
PRECIPITATION CHANCES DURING THE PERIOD. TODAY/S PRIMARY FORECAST
CHALLENGE IS WITH REGARDS TO CONVECTIVE INITIATION ALONG THE COLD
FRONT...WHICH IS EXPECTED TO STALL OUT SOMEWHERE OVER NORTH TX BY
EARLY THIS AFTERNOON.
ONE CHALLENGE REGARDING CONVECTIVE INITIATION THIS AFTERNOON IS
FORECASTING WHERE THE FRONT WILL STALL OUT. 00 AND 06Z GUIDANCE
HAS FAILED TO COME UP WITH A CONSENSUS POSITION OF THE STALLED OUT
FRONT. THE COARSER RESOLUTION GUIDANCE INDICATES THAT THE FRONT
WILL STALL OUT NEAR THE DFW METROPLEX WHILE THE HIGHER RESOLUTION
GUIDANCE INDICATES THAT THE FRONT WILL MAKE IT AS FAR SOUTHEAST AS
A SULPHUR SPRINGS TO HILLSBORO TO GOLDTHWAITE LINE. NEITHER
SOLUTION INITIALIZED THE CURRENT POSITION OF THE FRONT
PERFECTLY...SO OPTED TO GO WITH A BLEND AND JUST PUSHED THE FRONT
FURTHER SOUTHEAST THAN PREVIOUS FORECAST HAD INDICATED FOR THIS
AFTERNOON. THINK THAT BEST PRECIPITATION CHANCES WILL REMAIN ALONG
THE FRONTAL BOUNDARY FOR THIS AFTERNOON...SO ADJUSTED POPS
ACCORDINGLY TAKING THE HIGHER AXIS OF 40/50 POPS A BIT FURTHER
SOUTHEAST FOR THIS AFTERNOON AND THIS EVENING.
THE OTHER CHALLENGE REGARDING CONVECTIVE INITIATION TODAY IS
IDENTIFYING A STRONG FORCING MECHANISM. THE STALLED OUT COLD FRONT
IS THE OBVIOUS FEATURE IN PLAY BUT THE LIMITING FACTOR REGARDING
FORCING ALONG THE FRONT IS THE FACT THAT IT IS EXPECTED TO BE
STATIONARY BY THIS AFTERNOON. WITHOUT MOVEMENT THERE WILL NO
FORCED CONVECTION OUT AHEAD OF THE FRONT ASSOCIATED WITH DYNAMIC
PRESSURE PERTURBATIONS. THE PRIMARY FORCING MECHANISM ASSOCIATED
WITH THE FRONT THEN APPEARS TO BE FRONTOGENESIS WHICH IS TYPICALLY
MAXIMIZED BEHIND THE LEADING EDGE OF THE SURFACE FRONT. MOST SREF
ENSEMBLE MEMBERS DEPICT A LOW LEVEL CAPPING INVERSION IN PLACE
OVER NORTH TX THIS AFTERNOON. WHILE WE WILL HAVE SOME MODEST LOW
LEVEL WARM AIR ADVECTION SOUTH OF THE FRONTAL BOUNDARY TODAY THE
PRESENCE OF THIS CAP /ASSUMING IT EXISTS/ SHOULD LIMIT THE
INITIATION OF TSTM ACTIVITY TO THE IMMEDIATE VICINITY OF THE FRONT.
WITH THIS IN MIND NARROWED THE BAND 30 TO 50 POPS TODAY TO THOSE
LOCATIONS WHERE THE FRONT MAY REASONABLY STALL OUT. DID NOT GO ANY
HIGHER THAN 50 POPS IN THE CWA THRU 00Z AS ALL CONVECTION ALLOWING
GUIDANCE KEEPS TSTM ACTIVITY OUT OF NORTH TX THIS AFTERNOON WHILE
ALL OTHER GUIDANCE INDICATES DEVELOPING CONVECTION ALONG THE FRONT
BETWEEN 21 TO 00Z. THE LACK OF LARGE SCALE FORCING FOR ASCENT
TENDS TO FAVOR A SLOW LIFTING OR STRONGER CAP SO WILL REMAIN
CAUTIOUS WITH REGARDS TO POPS UNTIL 12Z UPPER AIR DATA COMES IN AS
WELL AS AIRCRAFT DATA SOUNDING DATA LATER THIS MORNING.
IF TSTMS ARE ABLE TO INITIATE ALONG THE FRONT THIS
AFTERNOON...THERE IS A CHANCE THAT THEY WILL BECOME SEVERE. SREF
MEAN SURFACE BASED CAPE VALUES ARE AROUND 1000 J/KG SOUTH OF THE
FRONT TODAY AND ALL OPERATIONAL GUIDANCE ADVERTISES AT LEAST THIS
MUCH POTENTIAL INSTABILITY. DEEP LAYER SHEAR IS EXPECTED TO BE
AROUND 40 TO 50 KTS THIS AFTERNOON WHICH WOULD SUPPORT AN
ORGANIZED CONVECTIVE MODE. DEW POINT VALUES THIS MORNING ARE
EXCEPTIONALLY HIGH FOR NOVEMBER...WITH DEW POINTS IN THE LOWER 70S
OBSERVED FROM HEARNE SOUTHEAST TO THE GULF COAST. WE WOULD NEED
JUST A FEW BREAKS IN THE LOW CLOUD COVER THIS AFTERNOON TO SEE
CAPE VALUES JUMP UP ABOVE 1000 J/KG. BECAUSE CLOUDS ARE EXPECTED
TO HOLD IN FOR MUCH OF THE DAY...OVERALL TORNADO POTENTIAL IS LOW
DUE TO POOR LOW LEVEL LAPSE RATES LIMITING VORTEX STRETCHING
POTENTIAL. LARGE HAIL LOOKS TO BE THE PRIMARY THREAT IN THIS
ENVIRONMENT WITH THE DAMAGING WIND AND TORNADO POTENTIAL PERKING
UP IN ANY AREAS THAT SEE A FEW HOURS OF SUNSHINE TODAY. WOULD
EXPECT A LARGELY LINEAR/QLCS STORM MODE AS DEEP LAYER SHEAR
VECTORS ARE EXPECTED TO BE NEARLY PARALLEL TO THE STATIONARY
FRONT.
TSTM ACTIVITY IS EXPECTED TO INCREASE IN COVERAGE TONIGHT AS THE
SHALLOW COLD FRONT INTERACTS WITH THE DEVELOPING LOW LEVEL JET.
THE LOW LEVEL JET IS EXPECTED TO RAMP UP IN ADVANCE OF THE NEXT
APPROACHING SHORTWAVE TROUGH WHICH IS MUCH STRONGER THAN THE BAJA
TROUGH. THE COLD FRONT WILL EFFECTIVELY STEEPEN LOW LEVEL
ISENTROPIC SURFACES ALLOWING FOR SIGNIFICANT ISENTROPIC LIFT
AFTER MIDNIGHT AS THE LLJ RIDES OVER THIS BOUNDARY. THIS FORCING
IS MUCH MORE BROAD THAN THE NARROW FRONTOGENETIC FORCING ALONG THE
FRONT...SO WENT AHEAD AND SPREAD POPS OUT OVER MUCH OF NORTH TX
LATE OVERNIGHT AND THRU MONDAY MORNING AS THE FRONT GRADUALLY
LIFTS BACK NORTH MONDAY MORNING. STORMS SUNDAY NIGHT WILL LIKELY
BE ELEVATED IN NATURE AND SHOULD ONLY POSE A LOWER END SEVERE HAIL
THREAT.
MONDAY AFTERNOON THRU TUESDAY...THE TROUGH THAT CURRENTLY RESIDES
OFF THE NORTHERN CA COAST WILL MOVE THRU THE SOUTHERN PLAINS LATE
MONDAY AFTERNOON THRU THE EVENING HRS. THIS SHOULD RESULT IN
WIDESPREAD TSTM ACTIVITY THRU MUCH OF THE REGION DURING THIS
PERIOD. WITH STRONG FORCING FOR ASCENT ASSOCIATED WITH THE
POWERFUL UPPER TROUGH WENT AHEAD WITH SREF SUGGESTED POPS DUE TO
THE STRONG SYNOPTIC SIGNALS IN PLACE.
FOR OUR CWA...MOST CONFIDENT IN TSTM ACTIVITY NEAR ANY FRONTAL
BOUNDARY DURING THE PERIOD SO HAVE PLACED 80 POPS OR HIGHER NEAR
THE EXPECTED POSITION OF SYNOPTIC FRONTS. ANY STORMS THAT DEVELOP
MONDAY AFTERNOON OR EVENING WILL HAVE THE POTENTIAL TO BECOME
SEVERE WITH DEEP MOISTURE AND EVEN STRONGER SHEAR IN PLACE THAN
WHAT IS EXPECTED FOR SUNDAY AFTERNOON. PRIMARY SEVERE
THUNDERSTORM HAZARDS WILL BE DEPENDENT UPON WHERE FRONTAL
BOUNDARIES LIE AND WHERE STORMS DEVELOP. WHILE THE CONFIDENCE OF
TSTMS OCCURRING IS HIGH...THE CONFIDENCE REGARDING THESE DETAILS
IS FAIRLY LOW AT THIS TIME.
STORMS THAT DEVELOP ALONG THE RETREATING FRONTAL BOUNDARY/WARM
FRONT MONDAY AFTERNOON WILL TEND TO BE MORE QUASI-LINEAR IN
NATURE AS DEEP LAYER SHEAR REMAINS NEARLY PARALLEL TO THIS
BOUNDARY WITH LITTLE IN THE WAY OF A CAP IN PLACE. HEAVY RAINFALL
POTENTIAL IS CERTAINLY THERE DUE TO THE POTENTIAL FOR STORMS TO
TRAIN OVER ONE ANOTHER/S TRACK NEAR THE WARM FRONT. A MORE
DISCRETE MODE MAY BE EXPECTED ALONG THE DRYLINE MONDAY
AFTERNOON...HOWEVER THIS BOUNDARY IS EXPECTED TO BE PLACED WELL
WEST OF THE CWA. IT IS POSSIBLE FOR DISCRETE STORMS/SUPERCELLS TO
DEVELOP OUT WEST AND THEN MOVE EAST INTO THE CWA LATE MONDAY
AFTERNOON. STORMS WILL INCREASE IN COVERAGE MONDAY EVENING AS THE
ENTIRE STORM SYSTEM BEGINS TO MOVE NORTHEAST AND A COLD FRONT
MOVES THRU THE AREA ONCE AGAIN. UNLIKE TODAY...THIS FRONT IS
EXPECTED TO MOVE ALL THE WAY THRU NORTH TX BY TUESDAY MORNING.
FORCING ALONG THE MOVING COLD FRONT WILL ONCE AGAIN PROMOTE
QLCS/MULTICELL ACTIVITY DEPENDING ON POTENTIAL INSTABILITY AFTER
SUNSET.
FOR MONDAY AFTERNOON...STORMS NEAR THE WARM FRONT WILL CONTINUE TO
HAVE A PRIMARILY LARGE HAIL SEVERE TSTM THREAT WITH ENHANCED
DAMAGING WIND AND TORNADO POTENTIAL FOR ANY AREAS THAT RECEIVE A
FEW HRS OF SUNSHINE. IF DISCRETE SUPERCELLS ARE ABLE TO ORGANIZE
TO OUR WEST...THESE WOULD HAVE A MORE PROMINENT TORNADO AND
DAMAGING WIND THREAT AS WELL AS AN ATTENDANT LARGE HAIL. UNLESS
THIS ACTIVITY IS ABLE TO MOVE INTO THE CWA OR DEVELOP IN THE WAA
REGIME AWAY FROM FRONTAL BOUNDARIES BEFORE SUNSET...THE OVERALL
TORNADO POTENTIAL MAY BE LOW MONDAY AFTERNOON AND EVENING. THESE
DETAILS WILL BE DIFFICULT TO RESOLVE UNTIL TOMORROW WHEN
CONFIDENCE IS HIGHER ON THE PLACEMENT OF SYNOPTIC FEATURES.
EXTENDED...DID NOT MAKE SIGNIFICANT CHANGES TO THE EXTENDED.
BEHIND THE COLD FRONT WE SHOULD SEE A FEW DAYS OF DRY WEATHER
AHEAD OF THE NEXT POWERFUL SHORTWAVE TROUGH. THIS TROUGH IS
EXPECTED TO MOVE INTO THE SOUTHERN PLAINS FRIDAY AFTERNOON OR
FRIDAY NIGHT. 00Z GUIDANCE WAS IN FAIRLY GOOD AGREEMENT ON THE
TIMING OF THIS FEATURE...AND POPS WILL NEED TO BE INCREASED IF
THIS CONSENSUS REMAINS IN TACT MOVING FORWARD. FOR NOW HAVE BROAD
BRUSHED 20 AND 30 POPS FOR FRIDAY AND FRIDAY NIGHT. CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 74 62 75 61 70 / 30 50 80 90 50
WACO, TX 79 68 80 64 76 / 40 40 50 80 60
PARIS, TX 79 63 74 62 69 / 50 60 80 90 80
DENTON, TX 69 55 71 56 67 / 30 50 80 90 40
MCKINNEY, TX 76 60 74 60 69 / 30 50 80 90 50
DALLAS, TX 75 64 77 63 70 / 30 50 80 90 50
TERRELL, TX 78 67 79 65 72 / 40 50 60 90 70
CORSICANA, TX 80 68 81 68 75 / 40 50 40 80 80
TEMPLE, TX 81 68 82 66 78 / 20 30 30 70 70
MINERAL WELLS, TX 64 55 72 53 69 / 30 40 80 90 30
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/75
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
528 AM CST SUN NOV 20 2011
.AVIATION...
LOW CLOUDS WILL BE PRESENT THROUGH MOST OF THIS FORECAST CYCLE AS A
COLD FRONT ENCROACHES AND THEN STALLS NEAR THE METROPLEX TODAY.
ONE OF THE MANY CHALLENGES TO THIS FORECAST IS HOW FAR SOUTHEAST
THE FRONT WILL MAKE IT BEFORE COMING TO REST...THEN WHEN IT WILL
LIFT NORTH AS THE WEST COAST UPPER LOW DEEPENS AND APPROACHES THE
REGION. A MODEL BLEND SEEMS MOST LOGICAL AT THIS TIME FOR FRONTAL
POSITION AND RESPECTIVE WIND FORECAST AT THE AREA TERMINALS. NAM
AND RUC ARE WELL AHEAD OF THE GFS ON SOUTHEASTWARD MOVEMENT OF THE
BOUNDARY...BUT APPEAR TO HAVE INITIALIZED ITS POSITION TOO FAR
SOUTHEAST. GFS JUST SEEMS TOO SLOW ON THE FORWARD PROGRESS. FOR
THIS FORECAST SET...WILL CONTINUE WITH THE IFR CIGS UNTIL MID-LATE
MORNING WITH VEERING WINDS AHEAD OF THE FRONT. MVFR CONDITIONS
THEN EXPECTED THE REST OF THE DAY AND WILL ADVERTISE FROPA AT OR
JUST BEFORE NOON LOCAL FOR THE METRO AREA TAF SITES. WILL INDICATE
VEERING WINDS AT ACT BUT THINK THE BOUNDARY MAY BECOME STATIONARY
BEFORE REACHING THE ACT TERMINAL. FRONT WILL THEN LIFT NORTH
TOMORROW MORNING BRINGING SE WINDS AREA-WIDE.
WILL INCLUDE VCSH BEGINNING MIDDAY TODAY. FEEL THE BEST CHANCES
FOR THUNDERSTORMS WILL BE TONIGHT AS OVERALL ASCENT INCREASES AND
THE FRONT PROVIDES FOCUS FOR DEVELOPMENT. CB IS POSSIBLE LATE THIS
AFTERNOON...BUT WITH THE PRESENCE OF A CAP THROUGH MOST OF THE DAY
WILL HOLD OFF MENTION OF CB UNTIL 21/02Z WHEN LOW LEVEL JET BEGINS
TO MATERIALIZE AND ELEVATED TS BECOME MORE LIKELY.
30
&&
.PREV DISCUSSION... /ISSUED 508 AM CST SUN NOV 20 2011/
EARLY MORNING WATER VAPOR IMAGERY DEPICTED SHORTWAVE TROUGHS OVER
THE NORTHERN CONUS ROCKIES...OVER THE BAJA PENINSULA AND JUST OFF
THE NORTHERN CA COAST. A PLUME OF TROPICAL PACIFIC MOISTURE WAS
STREAMING OVER THE SOUTHERN ROCKIES AND OVER THE SOUTHERN PLAINS.
A COLD FRONT CHARACTERIZED BY A STRONG LOW LEVEL BAROCLINIC ZONE
REMAINED JUST TO THE NORTHWEST OF THE CWA AS OF 09Z...AND WAS
LOCATED APPROXIMATELY ALONG AN ARDMORE TO THROCKMORTON LINE.
ALTHOUGH THE FRONT HAS SLOWED DOWN SIGNIFICANTLY OVERNIGHT...IT
CONTINUES TO PUSH SOUTHEAST EARLY THIS MORNING AND WILL LIKELY
ENTER THE FAR NORTHWESTERN COUNTIES OF OUR FORECAST AREA BY 12Z.
TEMPERATURES FALL RAPIDLY BEHIND/NORTH OF THE FRONT WITH A 09Z
TEMPERATURE OF 61 AT BOWIE AND ONLY 46 AT WICHITA FALLS.
TODAY AND TONIGHT...THE BAJA SHORTWAVE TROUGH IS EXPECTED TO MOVE
QUICKLY NORTHEAST DURING THE DAY TODAY AND IS EXPECTED TO BE
LOCATED OVER THE CENTRAL PLAINS BY EARLY THIS EVENING. THIS FAST
MOVING BUT SOMEWHAT WEAK TROUGH WILL SPREAD SOME LARGE SCALE
FORCING FOR ASCENT OVER THE SOUTHERN PLAINS TODAY AHEAD OF THE
COLD FRONT. THE TROUGH ITSELF IS EXPECTED TO REMAIN WELL TO THE
NORTH OF THE CWA...SO IT WILL LIKELY NOT PLAY A SIGNIFICANT ROLE IN
PRECIPITATION CHANCES DURING THE PERIOD. TODAYS PRIMARY FORECAST
CHALLENGE IS WITH REGARDS TO CONVECTIVE INITIATION ALONG THE COLD
FRONT...WHICH IS EXPECTED TO STALL OUT SOMEWHERE OVER NORTH TX BY
EARLY THIS AFTERNOON.
ONE CHALLENGE REGARDING CONVECTIVE INITIATION THIS AFTERNOON IS
FORECASTING WHERE THE FRONT WILL STALL OUT. 00 AND 06Z GUIDANCE
HAS FAILED TO COME UP WITH A CONSENSUS POSITION OF THE STALLED OUT
FRONT. THE COARSER RESOLUTION GUIDANCE INDICATES THAT THE FRONT
WILL STALL OUT NEAR THE DFW METROPLEX WHILE THE HIGHER RESOLUTION
GUIDANCE INDICATES THAT THE FRONT WILL MAKE IT AS FAR SOUTHEAST AS
A SULPHUR SPRINGS TO HILLSBORO TO GOLDTHWAITE LINE. NEITHER
SOLUTION INITIALIZED THE CURRENT POSITION OF THE FRONT
PERFECTLY...SO OPTED TO GO WITH A BLEND AND JUST PUSHED THE FRONT
FURTHER SOUTHEAST THAN PREVIOUS FORECAST HAD INDICATED FOR THIS
AFTERNOON. THINK THAT BEST PRECIPITATION CHANCES WILL REMAIN ALONG
THE FRONTAL BOUNDARY FOR THIS AFTERNOON...SO ADJUSTED POPS
ACCORDINGLY TAKING THE HIGHER AXIS OF 40/50 POPS A BIT FURTHER
SOUTHEAST FOR THIS AFTERNOON AND THIS EVENING.
THE OTHER CHALLENGE REGARDING CONVECTIVE INITIATION TODAY IS
IDENTIFYING A STRONG FORCING MECHANISM. THE STALLED OUT COLD FRONT
IS THE OBVIOUS FEATURE IN PLAY BUT THE LIMITING FACTOR REGARDING
FORCING ALONG THE FRONT IS THE FACT THAT IT IS EXPECTED TO BE
STATIONARY BY THIS AFTERNOON. WITHOUT MOVEMENT THERE WILL NO
FORCED CONVECTION OUT AHEAD OF THE FRONT ASSOCIATED WITH DYNAMIC
PRESSURE PERTURBATIONS. THE PRIMARY FORCING MECHANISM ASSOCIATED
WITH THE FRONT THEN APPEARS TO BE FRONTOGENESIS WHICH IS TYPICALLY
MAXIMIZED BEHIND THE LEADING EDGE OF THE SURFACE FRONT. MOST SREF
ENSEMBLE MEMBERS DEPICT A LOW LEVEL CAPPING INVERSION IN PLACE
OVER NORTH TX THIS AFTERNOON. WHILE WE WILL HAVE SOME MODEST LOW
LEVEL WARM AIR ADVECTION SOUTH OF THE FRONTAL BOUNDARY TODAY THE
PRESENCE OF THIS CAP /ASSUMING IT EXISTS/ SHOULD LIMIT THE
INITIATION OF TSTM ACTIVITY TO THE IMMEDIATE VICINITY OF THE FRONT.
WITH THIS IN MIND NARROWED THE BAND 30 TO 50 POPS TODAY TO THOSE
LOCATIONS WHERE THE FRONT MAY REASONABLY STALL OUT. DID NOT GO ANY
HIGHER THAN 50 POPS IN THE CWA THRU 00Z AS ALL CONVECTION ALLOWING
GUIDANCE KEEPS TSTM ACTIVITY OUT OF NORTH TX THIS AFTERNOON WHILE
ALL OTHER GUIDANCE INDICATES DEVELOPING CONVECTION ALONG THE FRONT
BETWEEN 21 TO 00Z. THE LACK OF LARGE SCALE FORCING FOR ASCENT
TENDS TO FAVOR A SLOW LIFTING OR STRONGER CAP SO WILL REMAIN
CAUTIOUS WITH REGARDS TO POPS UNTIL 12Z UPPER AIR DATA COMES IN AS
WELL AS AIRCRAFT DATA SOUNDING DATA LATER THIS MORNING.
IF TSTMS ARE ABLE TO INITIATE ALONG THE FRONT THIS
AFTERNOON...THERE IS A CHANCE THAT THEY WILL BECOME SEVERE. SREF
MEAN SURFACE BASED CAPE VALUES ARE AROUND 1000 J/KG SOUTH OF THE
FRONT TODAY AND ALL OPERATIONAL GUIDANCE ADVERTISES AT LEAST THIS
MUCH POTENTIAL INSTABILITY. DEEP LAYER SHEAR IS EXPECTED TO BE
AROUND 40 TO 50 KTS THIS AFTERNOON WHICH WOULD SUPPORT AN
ORGANIZED CONVECTIVE MODE. DEW POINT VALUES THIS MORNING ARE
EXCEPTIONALLY HIGH FOR NOVEMBER...WITH DEW POINTS IN THE LOWER 70S
OBSERVED FROM HEARNE SOUTHEAST TO THE GULF COAST. WE WOULD NEED
JUST A FEW BREAKS IN THE LOW CLOUD COVER THIS AFTERNOON TO SEE
CAPE VALUES JUMP UP ABOVE 1000 J/KG. BECAUSE CLOUDS ARE EXPECTED
TO HOLD IN FOR MUCH OF THE DAY...OVERALL TORNADO POTENTIAL IS LOW
DUE TO POOR LOW LEVEL LAPSE RATES LIMITING VORTEX STRETCHING
POTENTIAL. LARGE HAIL LOOKS TO BE THE PRIMARY THREAT IN THIS
ENVIRONMENT WITH THE DAMAGING WIND AND TORNADO POTENTIAL PERKING
UP IN ANY AREAS THAT SEE A FEW HOURS OF SUNSHINE TODAY. WOULD
EXPECT A LARGELY LINEAR/QLCS STORM MODE AS DEEP LAYER SHEAR
VECTORS ARE EXPECTED TO BE NEARLY PARALLEL TO THE STATIONARY
FRONT.
TSTM ACTIVITY IS EXPECTED TO INCREASE IN COVERAGE TONIGHT AS THE
SHALLOW COLD FRONT INTERACTS WITH THE DEVELOPING LOW LEVEL JET.
THE LOW LEVEL JET IS EXPECTED TO RAMP UP IN ADVANCE OF THE NEXT
APPROACHING SHORTWAVE TROUGH WHICH IS MUCH STRONGER THAN THE BAJA
TROUGH. THE COLD FRONT WILL EFFECTIVELY STEEPEN LOW LEVEL
ISENTROPIC SURFACES ALLOWING FOR SIGNIFICANT ISENTROPIC LIFT
AFTER MIDNIGHT AS THE LLJ RIDES OVER THIS BOUNDARY. THIS FORCING
IS MUCH MORE BROAD THAN THE NARROW FRONTOGENETIC FORCING ALONG THE
FRONT...SO WENT AHEAD AND SPREAD POPS OUT OVER MUCH OF NORTH TX
LATE OVERNIGHT AND THRU MONDAY MORNING AS THE FRONT GRADUALLY
LIFTS BACK NORTH MONDAY MORNING. STORMS SUNDAY NIGHT WILL LIKELY
BE ELEVATED IN NATURE AND SHOULD ONLY POSE A LOWER END SEVERE HAIL
THREAT.
MONDAY AFTERNOON THRU TUESDAY...THE TROUGH THAT CURRENTLY RESIDES
OFF THE NORTHERN CA COAST WILL MOVE THRU THE SOUTHERN PLAINS LATE
MONDAY AFTERNOON THRU THE EVENING HRS. THIS SHOULD RESULT IN
WIDESPREAD TSTM ACTIVITY THRU MUCH OF THE REGION DURING THIS
PERIOD. WITH STRONG FORCING FOR ASCENT ASSOCIATED WITH THE
POWERFUL UPPER TROUGH WENT AHEAD WITH SREF SUGGESTED POPS DUE TO
THE STRONG SYNOPTIC SIGNALS IN PLACE.
FOR OUR CWA...MOST CONFIDENT IN TSTM ACTIVITY NEAR ANY FRONTAL
BOUNDARY DURING THE PERIOD SO HAVE PLACED 80 POPS OR HIGHER NEAR
THE EXPECTED POSITION OF SYNOPTIC FRONTS. ANY STORMS THAT DEVELOP
MONDAY AFTERNOON OR EVENING WILL HAVE THE POTENTIAL TO BECOME
SEVERE WITH DEEP MOISTURE AND EVEN STRONGER SHEAR IN PLACE THAN
WHAT IS EXPECTED FOR SUNDAY AFTERNOON. PRIMARY SEVERE
THUNDERSTORM HAZARDS WILL BE DEPENDENT UPON WHERE FRONTAL
BOUNDARIES LIE AND WHERE STORMS DEVELOP. WHILE THE CONFIDENCE OF
TSTMS OCCURRING IS HIGH...THE CONFIDENCE REGARDING THESE DETAILS
IS FAIRLY LOW AT THIS TIME.
STORMS THAT DEVELOP ALONG THE RETREATING FRONTAL BOUNDARY/WARM
FRONT MONDAY AFTERNOON WILL TEND TO BE MORE QUASI-LINEAR IN
NATURE AS DEEP LAYER SHEAR REMAINS NEARLY PARALLEL TO THIS
BOUNDARY WITH LITTLE IN THE WAY OF A CAP IN PLACE. HEAVY RAINFALL
POTENTIAL IS CERTAINLY THERE DUE TO THE POTENTIAL FOR STORMS TO
TRAIN OVER ONE ANOTHERS TRACK NEAR THE WARM FRONT. A MORE DISCRETE
MODE MAY BE EXPECTED ALONG THE DRYLINE MONDAY AFTERNOON...HOWEVER
THIS BOUNDARY IS EXPECTED TO BE PLACED WELL WEST OF THE CWA. IT
IS POSSIBLE FOR DISCRETE STORMS/SUPERCELLS TO DEVELOP OUT WEST AND
THEN MOVE EAST INTO THE CWA LATE MONDAY AFTERNOON. STORMS WILL
INCREASE IN COVERAGE MONDAY EVENING AS THE ENTIRE STORM SYSTEM
BEGINS TO MOVE NORTHEAST AND A COLD FRONT MOVES THRU THE AREA ONCE
AGAIN. UNLIKE TODAY...THIS FRONT IS EXPECTED TO MOVE ALL THE WAY
THRU NORTH TX BY TUESDAY MORNING. FORCING ALONG THE MOVING COLD
FRONT WILL ONCE AGAIN PROMOTE QLCS/MULTICELL ACTIVITY DEPENDING ON
POTENTIAL INSTABILITY AFTER SUNSET.
FOR MONDAY AFTERNOON...STORMS NEAR THE WARM FRONT WILL CONTINUE TO
HAVE A PRIMARILY LARGE HAIL SEVERE TSTM THREAT WITH ENHANCED
DAMAGING WIND AND TORNADO POTENTIAL FOR ANY AREAS THAT RECEIVE A
FEW HRS OF SUNSHINE. IF DISCRETE SUPERCELLS ARE ABLE TO ORGANIZE
TO OUR WEST...THESE WOULD HAVE A MORE PROMINENT TORNADO AND
DAMAGING WIND THREAT AS WELL AS AN ATTENDANT LARGE HAIL. UNLESS
THIS ACTIVITY IS ABLE TO MOVE INTO THE CWA OR DEVELOP IN THE WAA
REGIME AWAY FROM FRONTAL BOUNDARIES BEFORE SUNSET...THE OVERALL
TORNADO POTENTIAL MAY BE LOW MONDAY AFTERNOON AND EVENING. THESE
DETAILS WILL BE DIFFICULT TO RESOLVE UNTIL TOMORROW WHEN
CONFIDENCE IS HIGHER ON THE PLACEMENT OF SYNOPTIC FEATURES.
EXTENDED...DID NOT MAKE SIGNIFICANT CHANGES TO THE EXTENDED.
BEHIND THE COLD FRONT WE SHOULD SEE A FEW DAYS OF DRY WEATHER
AHEAD OF THE NEXT POWERFUL SHORTWAVE TROUGH. THIS TROUGH IS
EXPECTED TO MOVE INTO THE SOUTHERN PLAINS FRIDAY AFTERNOON OR
FRIDAY NIGHT. 00Z GUIDANCE WAS IN FAIRLY GOOD AGREEMENT ON THE
TIMING OF THIS FEATURE...AND POPS WILL NEED TO BE INCREASED IF
THIS CONSENSUS REMAINS IN TACT MOVING FORWARD. FOR NOW HAVE BROAD
BRUSHED 20 AND 30 POPS FOR FRIDAY AND FRIDAY NIGHT.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 76 62 75 61 70 / 30 50 80 90 50
WACO, TX 82 69 80 64 76 / 30 30 50 70 60
PARIS, TX 76 63 74 62 69 / 50 60 80 90 70
DENTON, TX 72 55 71 56 67 / 30 50 80 90 40
MCKINNEY, TX 74 60 74 60 69 / 30 50 80 90 50
DALLAS, TX 78 64 77 63 70 / 30 50 80 90 50
TERRELL, TX 79 67 79 65 72 / 40 50 60 90 70
CORSICANA, TX 82 68 81 68 75 / 40 50 40 80 80
TEMPLE, TX 84 70 82 66 78 / 20 30 30 70 70
MINERAL WELLS, TX 71 55 72 53 69 / 30 40 80 90 30
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
30/69
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
304 PM CST SUN NOV 20 2011
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
304 PM CST SUN NOV 20 2011
THE MAIN FOCUS GOING INTO MID WEEK IS ON THE POTENTIAL FOR RAIN ON
TUESDAY AS A STORM SYSTEM MOVES THROUGH THE REGION.
CURRENTLY...A RIDGE OF HIGH PRESSURE EXTENDS FROM SOUTHERN ONTARIO
TOWARD SOUTHERN MINNESOTA. SOME LOW LEVEL STRATUS HAS LINGERED
ACROSS MUCH OF THE REGION TODAY DUE TO MOISTURE STUCK UNDER A
900MB INVERSION ON THE SOUTHEAST SIDE OF THIS RIDGE. THIS STRATUS
HAS BEEN SLOW TO ERODE TODAY WITH THE CORE OF THIS RIDGE SHIFTING
EAST INTO THE GREAT LAKES..THOUGH IT HAS LOOKED A BIT MORE
CELLULAR ON THE LAST FEW VISIBLE SCANS. WITH INCREASING LOW LEVEL
SUBSIDENCE...SKIES ARE EXPECTED TO CLEAR FROM WEST TO EAST THIS
EVENING WITH 20.18Z RUC FORECAST SOUNDINGS SHOWING THE LOW LEVEL
RH DECREASING THIS EVENING. THOUGH SKIES MAY BRIEFLY CLEAR THIS
EVENING...ADDITIONAL MID TO UPPER LEVEL CLOUD COVER IS EXPECTED TO
MOVE IN TONIGHT AHEAD OF A WEAK MID TO UPPER LEVEL WAVE THAT WILL
LIFT OUT OF THE SOUTHERN PLAINS AND HELP TO BRING SKY COVER BACK UP.
THE FOCUS THEN GOES TO TUESDAY AS A CLOSED LOW CURRENTLY ALONG THE
CALIFORNIA COAST PROPAGATES THROUGH THE FOUR CORNERS REGION TOMORROW
BEFORE ENDING UP NEAR THE SOUTHERN GREAT LAKES ON TUESDAY. THE
TREND WITH THE 20.12Z GUIDANCE HAS BEEN TO GO TOWARD HAVING A
STRONGER MID LEVEL TROUGH COME THROUGH THAT BRINGS RAIN TO THE
REGION. THE 20.12Z NAM AND ECMWF ARE THE FIRST TWO FORMS OF
GUIDANCE TO SHOW THIS PROGRESSION WHILE THE 20.12Z GFS KEEPS THE
BULK OF THE PRECIPITATION TO THE SOUTHEAST. THE PATH OF THE
SURFACE LOW DOES NOT LOOK MUCH DIFFERENT THAN WHAT PREVIOUS RUNS
HAVE SHOWN...BUT THE STRONGER MID LEVEL TROUGH LEADS TO A LARGER
AREA OF MID LEVEL QG FORCING AND IN TURN A LARGER AREA OF
PRECIPITATION. THOUGH SURFACE TEMPERATURES ARE EXPECTED TO BE IN
THE 30S TO LOW 40S...20.12Z NAM BUFKIT SOUNDINGS LOOK WARM ENOUGH
IN THE LOWEST 4KFT TO KEEP THE PRECIPITATION TYPE AS RAIN FOR THIS
EVENT. AT THIS POINT...IT APPEARS THAT RAIN WOULD START UP TUESDAY
MORNING AND END BY TUESDAY EVENING.
OTHER THAN THAT...TEMPERATURES WILL REMAIN SEASONAL IN THE 40S
FOR HIGHS AND 20S FOR LOWS WITH WEAK LOW LEVEL WARM AIR ADVECTION
EXPECTED THROUGH MID WEEK. 850MB TEMPERATURES WILL GRADUALLY RISE
FROM -2C TONIGHT TO AROUND 1C ON MONDAY...THEN TO 3-5C ON
WEDNESDAY AS A WARMER AIR MASS BEGINS TO SPREAD INTO THE REGION.
.LONG TERM...WEDNESDAY NIGHT INTO SUNDAY
304 PM CST SUN NOV 20 2011
CONDITIONS ARE LOOKING IDEAL FOR THE START OF THE HOLIDAY TRAVEL
SEASON WITH WARM SOUTHWESTERLY FLOW SETTING UP WEDNESDAY NIGHT
INTO FRIDAY WITH A SURFACE RIDGE IN THE SOUTHEAST US AND THE NEXT
LOW PRESSURE SYSTEM FORMING IN SOUTHERN CANADA. PERHAPS THE ONLY
CONCERN IS WITH HOW WINDY IT WILL BE ON THANKSGIVING WITH 20.12Z
GFS SOUNDINGS SHOWING SOUTH TO SOUTHWEST WINDS OF AROUND 15-17KTS
IN THE HIGHER TERRAIN WITH GUSTS UP TO AROUND 25-30KTS. BEYOND
THIS...925-850MB MOISTURE TRANSPORT WILL BE ON THE INCREASE AHEAD
OF THE NEXT TROUGH AND COLD FRONT THAT WILL MOVE INTO THE REGION
ON FRIDAY. THERE ARE SOME TIMING DIFFERENCES BETWEEN THE 20.12Z
GFS AND ECMWF WITH THE GFS BRINGING THIS PRECIPITATION AND FRONT
IN FASTER THAN THE ECMWF. THE ECMWF ALSO SPINS UP A SECONDARY
SURFACE LOW ON FRIDAY NIGHT INTO SATURDAY AND LINGERS THE
PRECIPITATION LONGER THAN WHAT THE GFS SHOWS. AT THIS POINT IT
APPEARS THAT THE THERMAL PROFILE WOULD BE WARM ENOUGH TO KEEP THE
PRECIPITATION TYPE IN ALL LIQUID FORM UNTIL PERHAPS THE VERY END
OF THE EVENT WHEN THE COLDER AIR MOVES IN.
&&
.AVIATION...THROUGH 18Z MONDAY
1159 AM CST SUN NOV 20 2011
IFR/MVFR STRATUS A BIT PROBLEMATIC TODAY WITH LOW LEVEL MOISTURE
TRAPPED BELOW PERSISTENT SUBSIDENCE INVERSION. THE RIDGE AXIS THAT
IS PRODUCING THIS SUBSIDENCE WILL SHIFT EAST OF THE REGION THIS
EVENING...ALLOWING FOR SOUTHEAST WINDS AND A SHIFT NORTHWARD OF THE
STRATUS OUT OF THE KRST/KLSE TAF SITE WHILE DISSIPATING AT THE SAME
TIME. THESE CLOUDS WILL THEN BE REPLACED WITH MID/HIGH CLOUDS AFTER
MIDNIGHT AHEAD OF A WEAK MID-LEVEL MOVING EAST OUT OF THE
INTERMOUNTAIN WEST. BASES OF THESE CLOUD ARE EXPECTED TO BE AOA
10KFT AFTER MIDNIGHT...LOWERING TO 7-8KFT AFTER 09Z. MODELS SHOW
THIS MID CLOUD MOVING NORTH/EAST OF THE TAF SITES MONDAY AFTERNOON.
SURFACE WINDS WILL BE WEAK FROM THE SOUTHEAST OVERNIGHT...THEN
EVENTUALLY VEER TO THE SOUTHWEST AFTER 18Z MONDAY AND GENERALLY
REMAINING BELOW 10KT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
304 PM CST SUN NOV 20 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...DAS
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...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
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 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 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 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 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...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
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 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 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 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 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
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