FXUS61 KCTP 042100
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
400 PM EST FRI DEC 4 2009

.SYNOPSIS...
A DEVELOPING STORM SYSTEM NEAR THE GULF STATES WILL QUICKLY
LIFT NORTHWARD ALONG THE COAST ON SATURDAY...AND WILL BE LOCATED
EAST OF NEW ENGLAND SUNDAY MORNING. HIGH PRESSURE OVER THE TENNESEE
VALLEY WILL BUILD EASTWARD BRINGING MAINLY DRY CONDITIONS TO THE 
AREA ON SUNDAY INTO TUESDAY. THERE COULD BE A FEW RAIN OR SNOW
SHOWERS LATER MONDAY...AS A WEAK COOL FRONT DROPS SOUTHWARD 
FROM CANADA. ANOTHER LARGE STORM SYSTEM MOVING NORTHEAST FROM
THE ROCKIES TUESDAY NIGHT WILL BRING ANOTHER ROUND OF MILD AND
WINDY WEATHER TO THE AREA LATE TUESDAY NIGHT INTO WED. THE RAIN
COULD MIX WITH SNOW EARLY ON TUESDAY NIGHT. COLDER TEMPERATURES
WILL FOLLOW FOR THE LATER PART OF THE WEEK...WITH A CHANCE OF 
LAKE EFFECT SNOW SHOWERS.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
PARTIAL CLEARING EARLY ON TONIGHT...THEN CLDS INCREASE LATER ON.
SOME LIGHT SNOW DEVELOPING AFTER 5 AM NEAR THE MARYLAND BORDER.

&&

.SHORT TERM /6 AM SATURDAY THROUGH 6 AM SATURDAY/...
INCREASING CONCERN FOR SEVERAL INCHES OF SNOW ON SATURDAY...AS
THE UPPER LEVEL TROUGH MOVES TOWARD THE AREA. SFC TRACK NOT AS 
IMPORTANT AS THE LOCATION OF THE DEFORMATION SNOW. LOOKING
AT RADAR AND SATELLITE DATA...SHOWS CLDS MOVING QUICKLY TO THE NE.
DID CONSIDER AN ADVISORY FOR SE AREAS ON SAT...BUT DECIDED TO GO 3
INCHES OR LESS IN ABOUT 18 HRS...GIVEN OTHERS...HPC CHAT... AND
THAT MODELS STILL SHOW QUITE A BIT OF SPREAD WITH THE UPPER LEVEL
LOW TRACK ETC.

&&

.LONG TERM /SATURDAY THROUGH FRIDAY/...
SUNDAY AND MOST OF MONDAY LOOK OK...WITH TEMPS NEAR OR SLIGHTLY
ABOVE NORMAL. WAS THINKING OF GOING WITH A DRY FCST ON MONDAY...
GIVEN THE LARGE SCALE PATTERN...AND THE NAM...BUT THE GFS SHOWS
SOME PCPN. DID CUT POPS BACK SOME ACROSS THE SE.

THE BIG STORY WILL BE ANOTHER DEEP...FAST MOVING LOW TRACKING 
NE ACROSS THE LAKES BY WED. WHILE THERE COULD BE SOME MIX EARLY
ON TUESDAY NIGHT...BUT BULK OF THE PCPN WILL BE RAIN. ANOTHER 
ROUND OF HEAVY RAIN...MILD TEMPS...AND WIND EXPECTED ON WED.

COLDER AIR AND LAKE EFFECT TO FOLLOW...BUT LIKE IN THIS CASE...
THE REAL COLD AIR MAY BE TAPERED BY THEN...AND FLOW ALOFT MAY
BE TOO MUCH FROM THE SW.

THERE IS PLENTY OF COLD AIR OVER CANADA...WITH THICKNESS 
BELOW 470...BUT THIS COLD MAY WORK BACK TO THE WEST WITH
TIME...SO COLD BLAST WILL BE LIKELY MODIFIED...AND ALONG
LAST A FEW DAYS.

&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
DRIER AIR HAS LIFTED MOST OF THE SC DECK TO VFR LEVELS...EXCEPT
OVER THE HIGHER ELEVATIONS OF THE LAURELS...WHERE CIGS JUST BLO 3K
ARE STILL BEING NOTED. SFC RIDGE AND DRIER AIR WILL CONTINUE TO
BUILD IN TONIGHT...BUT THIS WILL BE JUST AHEAD OF ADVECTING CLOUDS
FROM APPROACHING UPPER LOW. EXPECT GENERAL VFR CONDITIONS IN MOST
AREA THROUGH 12Z SAT...EXCEPT OVER LAURELS WHERE OCNL MVFR CIGS
WILL LINGER. WEST WINDS WILL LIGHTEN CONSIDERABLY LATER TODAY AND
TONIGHT AS SURFACE HIGH MOVES THROUGH.

OUTLOOK...
 
SAT...POTENTIAL SNOWFALL COULD PRODUCE MVFR/IFR ACROSS SOUTHERN PA.
SUN...VFR. 
MON...CHC SHSNRA WEST. VFR LIKELY EAST.
TUE...CHC MVFR CIGS WEST. VFR LIKELY EAST.

&&

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

&&

$$
SYNOPSIS...MARTIN
NEAR TERM...MARTIN
SHORT TERM...MARTIN
LONG TERM...MARTIN
AVIATION...JUNG/GARTNER