FXUS61 KCTP 291526
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1026 AM EST SUN NOV 29 2009
.SYNOPSIS...
HIGH PRESSURE WILL BEGIN TO WEAKEN AS A MILD AND DRY END TO THE
WEEKEND IS IN STORE. AN AREA OF LOW PRESSURE PASSES TO THE NORTH
MONDAY AS A COLD FRONT APPROACHES THE REGION OVERSPREADING
SCATTERED RAIN SHOWERS EARLY MONDAY. MUCH COOLER AIR ARRIVES
TUESDAY BEHIND FRONTAL PASSAGE WITH RAIN CHANGING TO SNOW
SHOWERS. HIGH PRESSURE BRIEFLY RETURNS FOR THE MIDDLE OF THE WEEK
AHEAD OF ANOTHER STORM SYSTEM LATE IN THE WEEK. COLDER AIR WILL
SETTLE OVER THE STATE FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
CHALLENGES FOR TODAY RESIDE AROUND MAX TEMPS. WHERE MIXING HAS
STARTED...THE TEMPS HAVE RISEN IMPRESSIVELY. KCBE AND KRSP JUST
MILES FROM OUR SRN BORDER HAVE POPPED UP TO 61F AND 54F
RESPECTIVELY - AND IT IS ONLY 10 AM! 8H TEMPS RISE TO +8C BY LATE
AFTN...SO MAXES ALONG THE SRN BORDER ESP THE ELEVATED SURFACES
SHOULD EASILY EXCEED 60F. EVEN IN KBFD IT IS 39F - ALREADY AT
THEIR NORMAL MAX FOR TODAY. HAVE TO THINK THEY TOO WILL GET
ANOTHER 10F OF WARMING TODAY WILL ALMOST FULL SUN. ONLY HIGH
CLOUDS FOR THE 300-400SM UPSTREAM AT THIS POINT...BUT THESE SHOULD
OVERSPREAD THE NWRN MTS BY SUNSET. PRECIP WILL HOLD OFF UNTIL AFT
SUNSET.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH 6 PM MONDAY/...
SEVERAL MESOSCALE SOLUTIONS PROG A WEAK VORT MAX LIFTING INTO
SOUTHERN ONTARIO EARLY THIS EVE LAYING A FRONTAL BNDRY SW THRU
CENTRAL OH. VORT MAX BRIEFLY AMPLIFIES AFT 00Z AHEAD OF 500MB
TROUGH AXIS. ENSEMBLES HAVE HIGH CONFIDENCE OF 30-40KT NOCTURNAL
LLVL JET DEVELOPING...ALONG WITH INCREASED LIFT AND MOISTURE
INTRUSION INTO THE BNDRY LYR. THUS HAVE INCREASED POPS TO
CATEGORICAL ACROSS THE NW MTNS BTWN 6-12Z. LOW/NIL POPS ON ORDER
FOR THE LWR SUSQ FOR THE NIGHT. TEMPS WILL REMAIN MILD THRU THE
NIGHT AS CLOUDS THICKEN. FROPA TIMING VERY CONSISTENT IN CUTTING
OFF MOST PRECIP BY 12Z IN THE NW...BUT THEN COLD ADVECTION KICKS
IN AND SCT SHRA/SN EXPECTED OFF THE LAKE. PRECIP SLIDE QUICKLY
EWRD THRU THE MORNING HRS AND MAY EVEN BE DRY AFT 18Z OVER MOST OF
THE AREA. A WEAK WAVE ROLLING POLEWARD ALONG THE FRONT OVER THE
CAROLINAS COULD HOLD THE CHCS FOR PRECIP UP OVER THE SE IN THE
AFTN...BUT BY EVENING IT SHOULD BE DRY THERE. TEMPS MAY HOLD OR
DROP THRU THE DAY ON MONDAY UNDER THE GOOD COLD ADV. QPF MAY GET
TO A QUARTER OF AN INCH OVER THE WEST...BUT IT COULD STILL REMAIN
DRY IN THE SE. LITTLE OR NO SNOW ACCUMS EXPECTED IN THE W DURING
THE DAYLIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
LEFT PACKAGE CLOSE TO WHAT WE HAD.
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 /15Z SUNDAY THROUGH THURSDAY/...
VFR CONDS WILL PERSIST THRU 00Z FOR ALL AIRFIELDS ACROSS CENTRAL
PA. WINDS WILL TURN SWSTRLY WITH OCCASIONAL GUSTS EXPECTED ARND 15
TO 20KTS AFT 18Z THRU 00Z. MOISTURE SLOWLY POOLS INTO NW MTNS
AIRFIELDS IN THE FORM OF CLOUDS. MVFR CIGS WILL EVENTUALLY
OVERSPREAD THE REGION...HOWEVER GUIDANCE APPEARS TO NOT FEATURE
THIS UNTIL 02Z FOR BFD AND UNTIL 04-08Z FOR JST/AOO/UNV. FURTHER
EAST CIGS SHUD HOLD UP ARND 10KFT AGL. CONFIDENCE IS GENERALLY
HIGH WITH PRECIP TIMING. NOW IT APPEARS PRECIP WILL PUSH INTO
CENTRAL PA BTWN 06-12Z WITH MAINLY MVFR CONDS AND ISO IFR CIGS.
BFD MAY DRY OUT BY 14Z MON...BUT LAKE EFFECT CLOUDS AND SHRA/SN
MAY KICK IN SHORTLY AFTER UNDER COLD ADV AND WNW LLVL FLOW.
OUTLOOK...
TUE...IFR/MVFR W IN POST FRONTAL SHSN. VFR E.
WED...VFR.
WED PM/THUR...MVFR TO IFR CIGS. LGT SHSN NW/SHRA SE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BEACHLER
NEAR TERM...DANGELO/BEACHLER
SHORT TERM...DANGELO/BEACHLER
LONG TERM...MARTIN
AVIATION...BEACHLER
