000
FXUS61 KCTP 240053
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
753 PM EST MON NOV 23 2009

.SYNOPSIS...
A WEAK WAVE OF LOW PRESSURE WILL PASS OFF THE EASTERN SEABOARD
TONIGHT FOLLOWED BY A WEAK COLD FRONT ON WEDNESDAY. A MORE
SIGNIFICANT COLD FRONT WILL APPROACH FOR LATER IN THE WEEK
BRINGING COLD AND BLUSTERY CONDITIONS ACROSS PENNSYLVANIA FRIDAY
AND SATURDAY.

&&

.NEAR TERM /UNTIL 7 AM TUESDAY MORNING/...
MOISTURE CONTINUES TO BUILD UP IN THE LOWER 15KFT OF THE ATMOS.
DESPITE THE VERY LIGHT RAINFALL...ALMOST EVERYWHERE ACROSS THE SRN
HALF OF THE AREA IS GETTING A FEW HUNDREDTHS. LIKELY TO CATG POPS
WILL BE GOOD FOR MOST OF THE AREA OVERNIGHT. PRECIP MAY TAPER OFF
LATE...BUT NOT BEFORE MOST GET WET. WITH THE CLOUD COVER AND
EASTERLY FLOW...OVERNIGHT LOWS WILL AVERAGE WELL ABOVE SEASONAL
NORMS...AND MAY NOT MOVE DOWNWARD MORE THAN A DEG OR TWO FROM
CURRENT READINGS. 

&&

.SHORT TERM /7 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
EXCEPT FOR SOME PATCHY LEFT OVER DRIZZLE IN THE MORNING...RIDGING
AT SFC AND ALOFT SHOULD RESULT IN A DRY TUESDAY FOR MOST OF THE
AREA. HOWEVER...RESIDUAL LL MOISTURE TRAPPED BENEATH SUBSIDENCE
INVERSION WILL LIKELY KEEP SKIES MOSTLY CLOUDY. DESPITE LACK OF
INSOLATION...HIGHS STILL CONTINUE TO BE ABV NORMAL IN THIS MILD
AIR MASS...AVERAGING IN THE L/M50S. 

IT WILL REMAIN MILD AND CLOUDY TUES NIGHT IN THE DEVELOPING
SOUTHERLY FLOW AHEAD OF THE NEXT WAVE DIVING INTO THE OHIO
VALLEY. I TRIMMED POPS BACK TO A BLEND OF THE DRY GMOS AND VERY
WET SREF POPS. QPF LOOKS PRETTY UNIMPRESSIVE AS BEST FORCING WILL
HOLD OFF TIL MID WEEK OR EVEN THURSDAY.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
VEERING SLY LLVL FLOW SHOULD KEEP LOW CLOUDS/OCNL DRIZZLE LOCKED
IN ACROSS MUCH OF THE AREA EARLY ON WED AS MSTR ASCENDS THE CNTRL
MTNS. THIS IS SUPPORTED BY FCST SNDGS AND HI RESOLUTION NAM/WRF
DATA. A LEAD SHORTWAVE MAY BRING SOME SCT SHWRS LATER WED AFTN
INTO EARLY WED NGT.

OPERATIONAL MODELS AND ENSEMBLES CONTINUE TO CARVE OUT A DEEP ERN
TROF EVENTUALLY TAKING ON A NEGATIVE TILT BY THIS WEEKEND...WITH A
ACCOMPANYING COASTAL LOW LIFTING NEWD ALONG THE NEW ENG COAST.
THAT BEING SAID...CONFIDENCE IS FAIRLY HIGH WITH REGARDS TO COOLER
TEMPERATURES LATER IN THE PD. THE LARGE SCALE CYC FLOW SHOULD
ALSO MAKE FOR BREEZY CONDITIONS WITH PERHAPS SOME LAKE EFFECT
RAIN/SNOW SHWRS.

THERE IS STILL UNCERTAINTY AS TO A POSSIBLE DYNAMIC COOLING/PTYPE
CHANGEOVER /FROM RAIN TO SNOW/ SCENARIO THUR NGT-FRI AS 500MB
HEIGHTS CRASH AND THE UPPER LOW MOVES OVERHEAD OR SOUTH OF PENN.
HAVE INDICATED RAIN OR SNOW FOR NOW IN THE GRIDS WITH POPS IN THE
50-60PCT RANGE.

HIGH PRES IS FCST TO BUILD INTO THE REGION BY LATE IN THE WEEKEND
AND SHOULD PROVIDE IMPROVING CONDS AND A GRADUAL MODERATION IN
TEMPS. ANOTHER FRONTAL SYS MAY IMPACT THE AREA EARLY NEXT WEEK.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
CONSID MVFR TRENDING IFR CIGS FOR PA AIRFIELDS...THEN REMAINING AT
IFR CIGS THRU AT LEAST 12Z TUE. RADAR RETURNS INDICATE NUMEROUS
SHRA ACROSS THE REGION...HOWEVER SOME PRECIP THIS EVE WILL
EVAPORATE BEFORE REACHING THE SFC AS THE PERSISTENT EASTERLY FLOW
DRIES THE NEAR SFC CONDITIONS. VSBYS WILL GRADUALLY LOWER
OVERNIGHT TO ARND 1-3SM AND PERSIST THRU 12-14Z. 

ATTM GUIDANCE DOES NOT SUGGEST MIXING WILL IMPROV CONDS VERY
FAST...SO WILL HOLD ONTO IFR TO MVFR CONDS THRU AT LEAST 19Z FOR
MOST AIRFIELDS IN CENTRAL PA...ESP JST/AOO/UNV/IPT.

OUTLOOK...
WED...MVFR/IFR IN PRE-FRONTAL SHRA 
THU-FRI...MVFR WITH CHC -SHRASN. 
SAT...MVFR TO VFR. SLT CHC -SHRASN

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LA CORTE
NEAR TERM...DANGELO/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...STEINBUGL
AVIATION...BEACHLER