FXUS61 KCTP 050101
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
801 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 TENNESSEE
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 /00Z SATURDAY THROUGH WEDNESDAY/...
MID AND HIGH LVL CLOUD SHIELD OVERSPREADING CENTRAL PA THIS
EVENING IN ADVANCE OF STORM SYSTEM GATHERING OVR THE GULF OF
MEXICO. SFC RIDGE AND ASSOCIATED DRY LOW LVL AIR SHOULD ENSURE VFR
CONDS AND LGT WINDS FOR MUCH OF THE NIGHT. HOWEVER...LATEST SHORT
RANGE MODEL DATA SUGGESTS LGT SNOW WILL BREAK OUT BTWN 09Z-12Z OVR
SOUTHERN PA AND RAPIDLY SPREAD TO THE NORTH BY LATE AM.
SOME UNCERTAINTY WITH REGARDS TO VSBYS ON SATURDAY...BUT 1-2SM SEEMS
LIKELY BY AFTN AT MOST TERMINALS BASED ON MODEL QPF AND MOS
GUIDANCE. EXCEPTION WILL BE NW MTNS /KBFD/ WHERE SNOW UNLIKELY AND
VFR CONDS MAY HOLD. SOUTHERN PA WILL BE CLOSEST TO STORM TRACK
AND COULD POSSIBLY RECEIVE A PERIOD OF HEAVIER SNOW /LIFR CONDS/
SOMETIME BTWN LATE MORNING AND EARLY EVENING.
OUTLOOK...
SUN...VFR.
MON...CHC SHSNRA WEST. VFR LIKELY EAST.
TUE...CHC MVFR CIGS WEST. VFR LIKELY EAST.
WED...POTENTIAL RAIN/ICE ALONG WITH IFR CONDS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MARTIN
NEAR TERM...MARTIN
SHORT TERM...MARTIN
LONG TERM...MARTIN
AVIATION...FITZGERALD
