FXUS61 KCTP 262057
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
357 PM EST THU NOV 26 2009
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE REGION LATER
TODAY...ACCOMPANIED BY NUMEROUS RAIN SHOWERS. MUCH COLDER AIR WILL
PUSH INTO THE REGION PROVIDING BLUSTERY AND UNSETTLED CONDITIONS
WHICH WILL LAST INTO SATURDAY. A RIDGE OF HIGH PRESSURE WILL BRING
FAIR BUT CHILLY WEATHER FOR MUCH OF SUNDAY BEFORE ANOTHER COLD
FRONT BRINGS A CHANCE FOR RAIN AND SNOW SHOWERS EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
SATELLITE...MESO ANAL AND RUC THERMAL FIELDS INDICATE THE COLD
FRONT IS ENTERING MY WESTERN ZONES AT THIS HOUR. SOME BREAKS IN
THE EXTENSIVE LOW CLOUD SHIELD HAVE DEVELOPED OVER CENTRAL AND
WESTERN AREAS...HOWEVER THE SUSQ VALLEY REMAINS STUBBORNLY COOL
AIR DAMMED WITH LINGERING LOW CLOUDS AND ONLY SLOWLY IMPROVING
VISIBILITIES.
AS THE FRONTAL BNDRY APPROACHES FROM THE WEST...SCATTERED SHOWERS
WILL BEGIN TO INCREASE OVER THE WRN ZONES AS THE AFTERNOON WEARS
ON...WITH CHANCES INCREASING INTO CENTRAL AREAS TWD EVENING.
CHALLENGE FOR TONIGHT CENTERS ON BOTH COVERAGE OF PRECIP AND
TIMING OF ANY KIND OF MIXING OR CHANGE OVER TO SNOW. 850MB TEMPS
COOL STEADILY BUT DON'T APPEAR TO BE COLD ENUF FOR ALL SNOW UNTIL
PERHAPS AROUND MIDNIGHT IN THE WEST WHEN TEMPS OF -5 TO -7 DEG C ARE
PROGGED. AS TROUGH AXIS SLOWLY PIVOTS TOWARDS CENTRAL PA...FLOW
TURNS W/NWLY AND INCREASED UPSLOPE EFFECT SHUD DEVELOP FOR THE
ALLEGHENIES. SREF SHOWS THE POTENTIAL FOR SOME ENHANCED
DEFORMATION PRECIP OVER NERN PA LATER TONIGHT AS DOES THE NEW
NAM...AFTER BACKING OFF THIS IDEA ON THE LAST RUN OF THE MODEL. IT
DOESN'T CHANGE THE THINKING MUCH WITH REGARDS TO SNOW TOTALS IN
THAT AREA...WITH TEMPERATURES INITIALLY BEING MARGINAL AND PRECIP
TYPE PROBABLY MIXED FOR A TIME. OVERALL I STUCK WITH THE IDEA THAT
THE SRN LAURELS WILL SEE THE BEST CHANCE FOR A FEW INCHES OF SNOW
LATE TONIGHT AND EARLY FRIDAY AS COLD AIR UPSLOPES INTO THAT AREA.
GENERALIZED DUSTING TO MAYBE A COUPLE OF INCHES FURTHER NORTH OVER
MY WESTERN HIGH TERRAIN. OF COURSE ANY SNOW COULD PROVIDE A TRAVEL
PROBLEM GIVEN THE HOLIDAY WEEKEND.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
THE FIRST SHOT OF TRUE (THOUGH QUITE ELEVATION DEPENDENT) LAKE
EFFECT/OROGRAPHIC SNOW ACROSS THE NORTHWEST MOUNTAINS AND LAUREL
HIGHLANDS WILL BE ONGOING FRIDAY AS A SHARP AND SLIGHTLY NEG TILT
UPPER TROUGH MOVES ACROSS PENN AND HELPS TO RAPIDLY INTENSIFY LOW
PRESSURE OFF THE MID ATLANTIC/SRN NEW ENGLAND COAST.
AS THE LOW DEEPENS RAPIDLY MOVING INTO THE GULF OF MAINE LATER
FRIDAY...WEST TO NORTHWEST WINDS WILL INCREASE TO 15 TO 20 MPH
WITH GUSTS OF 30 TO 35 MPH TWD EVENING.
QUESTION OF WHETHER OR NOT A MESOSCALE BAND OF DEFORMATION SNOW
CAN MANAGE TO FORM AND AFFECT NERN PA REMAINS. NEW GEM HUSTLES THE
BACKLASH PRECIP AWAY RAPIDLY INTO NEW ENGLAND LEAVING THE NAM AS
THE LONE WOLF WITH THE PRECIP THREAT. SO FOR NOW HAVE TO RIDE THE
CONSENSUS THAT INDICATES LITTLE MORE THAN NUISANCE AMOUNTS OVER MY
NERN ZONES.
AFTER MORE THAN 2 STRAIGHT WEEKS OF ABOVE NORMAL TEMPS...FRIDAY
WILL BE CHILLIER THAN NORMAL...THOUGH NOT TERRIBLY SO. THE CLOUDY
AND WINDY NW COUNTIES MAY BE IN THE 5-6 DEG BELOW NORMAL RANGE
WHILE THE REMAINDER OF THE REGION ENDS UP JUST SLIGHTLY BELOW
NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
NOT A LOT OF CHANGE FROM YESTERDAY. COASTAL STORM LESS OF A THREAT
NOW...THEN WHEN I WORKED ON WED. ASIDE FROM SOME LINGERING LAKE
EFFECT FRIDAY NIGHT INTO EARLY SATURDAY...NOT A LOT GOING ON.
THE LAKE EFFECT WILL BE SOMEWHAT LIMITED AFTER 00Z SAT...AS
HEIGHTS RISE...AND THE AIRMASS IS NOT ALL THAT COLD ANYWAY.
SKIES SHOULD CLEAR NICELY LATER SATURDAY INTO THE FIRST PART OF
SUNDAY...AS WINDS SHIFT MORE THE THE WEST...AND VERY WARM AIR
MOVES TOWARD THE AREA FROM THE WEST. THIS WILL LIKELY BRING
SOME HIGH AND MID CLDS TO THE AREA LATER ON SUNDAY. PERHAPS A
SHOWER ACROSS WESTERN AREAS LATE.
TIMING OF NEXT FRONT NOT REAL CLEAR...BUT NOW APPEARS FASTER
THAN YESTERDAY...MOVING ACROSS MONDAY NIGHT INTO EARLY TUE...
PERHAPS A FEW SHOWERS.
HIGH PRESSURE BUILDS ACROSS THE NORTHERN STATES BY MIDWEEK.
IT MAY BE SOMEWHAT STORMY TO THE SOUTH...AND THIS SYSTEM MAY
BRUSH THE AREA LATE WED INTO THU. LIKE YESTERDAY...WENT WITH
A CHC OF RAIN SHOWERS AND SNOW SHOWERS...AS TEMPS WILL BE
BORDERLINE TO THE WEST AND NORTH. HARD TO SEE A LOT GOING
ON...DIFFICULT TO SEE WHY THE GFS DEVELOPS SUCH A STRONG
STORM LATE WED INTO THU.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
SATELLITE SHOWS SOME BREAKS OVER CENTRAL AND WESTERN AREAS WHERE
CONDITIONS ARE VFR OR MVFR. WORST CONDITIONS REMAIN LOCKED IN OVER
EASTERN AREAS WHERE COLD AIR DAMMING IS STUBBORN AND KEEPING IFR
CIG/VIZ IN PLACE. EVEN HERE IMPROVEMENT WILL DEVELOP...HOWEVER
SLOWLY AS THE COLD FRONT MOVES THRU AND A WEST- NORTHWEST GRADIENT
DEVELOPS.
FRONT PUSHES THRU AND INCREASES UPSLOPE ACROSS THE ALLEGHENIES
AFT 00Z...THUS EXPECT CIGS/VSBYS TO DETERIORATE TO MVFR/IFR WITH
SCATTERED RAIN AND SNOW SHOWERS...EVENTUALLY GOING TO ALL SNOW.
OUTLOOK...
EARLY FRI...IFR WEST WITH MIXED RAIN-SNOW TURNING TO SNOW. ELSEWHERE
VFR/MVFR WITH SCATTERED MIXED RAIN-SNOW SHOWERS.
FRI-SAT...IFR/MVFR WEST AND NW IN FREQUENT HIGH TERRAIN SHSN. VFR
EAST OF THE ALLEGHENIES WITH NLY BRIEF MVFR IN SHRASN.
SUN...VFR.
MON...IFR/MVFR SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...LA CORTE
