FXUS61 KCTP 290332
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1032 PM EST SAT NOV 28 2009
.SYNOPSIS...
HIGH PRESSURE BUILDING OVER THE SOUTHEASTERN US WILL DEVELOP A
MILDER AND INCREASINGLY MOIST SOUTHWESTERLY FLOW FOR SUNDAY. A
COLD FRONT WILL MOVE THROUGH MONDAY MORNING BRINGING SCATTERED
SHOWERS. IT WILL THEN TURN BLUSTERY AS LAKE EFFECT SNOW SHOWERS
START UP BY LATE MONDAY AND LAST INTO TUESDAY. HIGH PRESSURE WILL
BUILD IN FOR A SHORT TIME DURING MID- WEEK BEFORE A STORM SYSTEM
IS EXPECTED TO AFFECT THE REGION THURSDAY. COLDER AIR WILL SETTLE
OVER THE STATE FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
CLOUDS HAVE FINALLY SCOURED OUT AFTER ANOTHER MAINLY CLOUDY BREEZY
COOL DAY OVER THE REGION.
MINS TONIGHT ARE A CHALLENGE WITH FLOW QUICKLY RETURNING TO THE
SOUTHEAST...BUT CLEAR/ING SKIES AND STRATIFICATION/DIMINISHING
WIND WILL WORK OPPOSE THIS. ADD TO THIS MIX THE HIGH RH/S AND
CLOUDS THAT THE GUIDANCE WANTS TO DEVELOP OVER THE ALLEGHENIES
LATER TONIGHT AND SUN MORNING. IT IS TOUGH TO SEE HOW WITH LITTLE
UPSTREAM MOISTURE IN THE OBS HOW THIS WILL HAPPEN. BUT...THE
UPSLOPE/LIFT COMBINED WITH THE INVERSION AND FURTHER WARMING ALOFT
COULD TRAP ENOUGH MOISTURE TO CREATE LOW STRATUS. MOS POINTS TO
EVEN IFR CONDITIONS EARLY IN THE MORNING FOR NW PA. WILL THEREFORE
TWEAK THE CLOUDS INTO THE 70-80PCT RANGE BY SUNRISE IN THE NW
THIRD OF THE CWA. THIS WOULD ALSO HELP TO KEEP TEMPS MILDER IN
THAT AREA. MINS WILL THEREFORE HOLD WITH CONTINUITY WHICH PUTS
MINS ONLY A FEW DEGS FROM CURRENTS IN THE NW. WITHOUT CLOUDS AND
NIL WIND WILL TAKE THE E/SE INTO THE L30S AS WELL. THIS MAKES FOR
A RATHER UNIFORM MIN T GRID MAP.
NO UPDATE NEEDED AS I MADE ONLY MINOR CHANGES TO THE FORECAST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SUNDAY HOLDS LOTS OF SUN FOR THE SE HALF...BUT THOSE IN THE NW MAY
START THE DAY MOSTLY CLOUDY...AGAIN. THIS TIME...THERE IS ONLY A
TINY LIGHT AT THE END OF THE TUNNEL FOR THEM. THIS IS BECAUSE WARM
ADVECTION KICKS IN BEFORE A SFC LOW WHICH WILL SHOULD TAKE A TRACK
THROUGH WRN NY STATE. THIS WILL CREATE MID/HIGH CLOUDS OVER THE NW
BY THE END OF THE DAY. THE REST OF THE STATE WILL BE SUNNY/MSUNNY.
THE 8H TEMPS APPCH +8C IN THE SRN TIER DURING THE AFTN. THIS WOULD
ORDINARILY MAKE ME THINK OF MAXES IN THE L60S...BUT THE LOW SUN
ANGLE AND LACK OF STRONG DOWNSLOPING FLOW WILL TEMPER MY FCST OF
MAXES IN THE S TO AROUND 60F. THESE ARE STILL 12F ABOVE SEASONAL
NORMS. WILL KEEP PRECIP OUT OF THE FCST FOR ALL DAY - BUT A
SPRINKLE IS POSSIBLE IN THE NW BY SUNSET.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
LEFT PACKAGE CLOSE TO WHAT WE HAD.
STILL LOOKING AT SOME SHOWERS SUNDAY NIGHT INTO MONDAY. EXPECT SOME
LAKE EFFECT SNOW SHOWERS MONDAY NIGHT INTO TUE...BUT BEST CHC WILL
BE AROUND SUNRISE TUESDAY...WHEN DIRECTIONAL SHEAR IS AT A MINIMUM.
BY TUE AFTERNOON...WINDS BACK TO THE SW...AND TEMPS START TO
WARM.
FOR THE MOST PART...WED STILL LOOKING DRY DURING THE DAY. MODELS
ONCE AGAIN A LITTLE FASTER WITH CLDS AND RAIN MOVING IN DURING THE
AFTERNOON ON WED...SO MADE MINOR ADJUSTMENTS TO THE ONSET OF THE
SHOWERS ACROSS THE SOUTH. REALLY JUST ADJUSTING IT BACK CLOSE TO
WHAT I HAD YESTERDAY.
THE NAM TODAY WANTS TO LIFT SYSTEM OUT OF THE SW ON WED...BUT
I STILL HAVE PROBLEMS WITH THE UPCOMING SYSTEM. PATTERN NOT REALLY
SET UP TO LOCK IN THE COLD AIR AND DRIVE A MAJOR COASTAL.
AT FIRST I TOOK OUT MENTION OF SNOW WED NIGHT ACROSS THE N AND W...
BASED ON SLIGHTLY WARMER TEMPS. HOWEVER...WITH TEMPS NEAR FREEZING
AND THE FURTHER EAST TRACK ON THE DGEX AND ECMWF...DECIDED TO LEAVE
IT IN.
THINK SYSTEM WILL BE WEAKER AND FASTER EAST THAN SOME MODELS HAVE
IT...LIKE THE GFS...BUT STILL MOST LIKELY AN INLAND TRACK. HPC AND
GFS TRACK IT TOWARD SYR. SPEED LOOKS FAIRLY GOOD. THUS COULD SEE
SOME HEAVY RAIN...AND EVEN SOME THUNDER ACROSS FAR EASTERN AREAS
ON THU...GIVEN LOW TRACK AND STRONG DYNAMICS...AS A STRONG WARM
FRONT SETS UP ACROSS THE FAR SE. SHOULD SYSTEM BE REAL STRONG...
THEN LEADING EDGE OF DRY AIR ALOFT ON THU COULD RESULT IN STRONG
WINDS AND A HEAVY RAIN THREAT. FOR NOW...DID UP QPF SOME AND ADD
THUNDER TO THE EAST ON THU.
LOOKS LIKE FLOW STAYS SW ALOFT ON THU NIGHT...THUS LAKE EFFECT
WILL BE MAINLY WEST OF THE MTS PRIOR TO LATER ON FRIDAY. WHILE
A DECENT SHOT OF COLD AIR WILL FOLLOW THE STORM...NOT SURE IF
IT WILL STAY AROUND VERY LONG. THINGS LOOKS LIKE THEY WOULD WARM
UP ON SUNDAY. WENT WITH AN INCREASE IN CLDS LATE SATURDAY.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
CLEAR SKIES AT ALL AIRFIELDS ATTM EXCEPT FOR KIPT AS AN AREA OF
HIGH PRESSURE STEADILY BUILDS IN FROM THE WEST AND COLD POOL ALOFT
SLIDES E. IPT IS ON THE SRN EDGE LOW CLOUD DECK LIFTING INTO NEW
ENGLAND. EXPECT CIGS THERE TO BECOME SCATTERED THEN SKC BY 01Z.
LLVL MSTR INCREASES FROM THE W LATER TONIGHT AS THE INVERSION
HOLDS AND DEWPOINTS RISE. 925MB MSTR GOES INTO THE 90+PCT RANGE
FOR MOST OF NW PA BEFORE 09Z. WILL THEREFORE LOWER CIGS AT KBFD
TONIGHT AND HINT AT THOSE CONDITIONS AT KJST AND KUNV. SOME BR ALSO
PSBL IN THE CENTRAL/ERN AIRFIELDS...ESP IN THE VALLEYS. BUT WITH GUID
VERY OPTIMISTIC WITH THE VISBYS WILL JUST MENTION TEMPOS FOR FOG
ATTM. VFR SHOULD LAST THRU ALL OF SUN FOR THE E...BUT LOWERING
CIGS IN THE W WILL EVENTUALLY LEAD TO SCT SHRA AS A FAST MOVING
AND DRY FRONT PUSHES THRU MON AM.
OUTLOOK...
TUE...IFR/MVFR W IN POST FRONTAL SHSN. VFR E.
WED...VFR.
WED PM/THUR...MVFR DROPPING TO IFR IN SN NW/RA SE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...MARTIN
AVIATION...DANGELO/GARTNER
