High Wind in Pennsylvania, December 14 to 15, 2001

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
124 PM EST FRI DEC 14 2001

TEMPS HOLDING UNDER CLDS AND OCC PRECIP AS SFC LOW MVS THRU UPR OH
VLY TWRD NRN ZNS. SHOWERS WITH A BIT OF THUNDER ALSO NEARING ERN OH.
MOVEMENT ON THOSE ECHOES IS NEAR 60 KTS. WHILE WE ARE RATHER
STABLE...CURRENT CONVECTION IS GOING IN +4 TO +6 LI/S. SO...WILL
CONTINUE MENTION OF THUNDER IN SRN ZNS THIS EVENING.

MOST INTERESTING FEATURE IN NEAR TERM FCST IS STRONG VORT MAX (27 TO
29 UNITS) TO PASS DIRECTLY OVER THE LAURELS LATE TONIGHT. THIS IS A
SITUATION WHERE THE MODELS OFTEN INDICATE LITTLE TO NO QPF...YET
VERTICAL MOTIONS AND OROGRAPHIC INFLUENCES COMBINE WITH STRONG CAA
AND MODEST MOISTURE TO PRODUCE A WHITE COATING. VALLEYS OF THE
LAURELS NOT LIKELY TO SEE MORE THAN A DUSTING...BUT RIDGETOPS MAY
GET AN INCH OR SO BY SUNRISE. THE SPEED OF VORTMAX AND ASSOCD
TIME OF FAVORABLE CONDITIONS WL LIMIT THE SNOW EVEN ON THE HIGHEST
POINTS. IN THE SHADOW OF THE LAURELS...WL MENTION SN BUT NO ACCUMS.
OTHER WESTERN ZNS WL CONTINUE PREV FCST OF MIX SHRA/SN LATE.

MOISTURE DRIES UP NICELY AFTER SUNRISE AND MAKES A DECENT ALBEIT
COLDER DAY FOR SATURDAY. SAT NITE MAY BE ONE OF THE COLDEST YET THIS
SEASON (BUT NOT ANYTHING ABNORMAL)...WITH TEENS AND L20S TO ABOUND
UNDER CLR SKIES AND CALM CONDITIONS. SUNDAY WL WORD WITH INCRS CLDS
WEST/ MSUNNY EAST AS MDLS HOLD OFF ON ANY PRECIP IN THE AREA UNTIL
AFT SSET ON SUNDAY.

EXTENDED RANGE THINKING...

MODELS CONTINUE THE TREND TOWARD A COOLER WEEK 3 OF DECEMBER THAN
THE PREVIOUS 2. HAVE BEEN MUCH ABOVE NORMAL SO EVEN A RETURN TO
AVERAGE WILL SEEM A LITTLE HARSH.

FOR EARLY NEXT WEEK...ECMWF IS ABOUT A DAY SLOWER THAN MRF WITH
SYSTEM MOVING INTO ERN US. ECMWF IS ALSO MUCH MORE INTENSE WHICH
WOULD EXPLAIN THE SPEED DIFFERENCE. MRF SHEARS SYSTEM OFF QUICKLY
WITH A SFC WAVE PASSING OFF MID ATL BY EARLY TUES...WHERE ECMWF HAS
A POTENT CYCLONE JUST MOVING INTO THE REGION BY THAT TIME. NEW AVN
DOES SLOW THINGS DOWN....NOT AS MUCH AS ECMWF THO. IT SHOWS POTENT
WAVE MOVING INTO CTRL APPALACHIANS BY EARLY MONDAY. A LOOK AT THE
SUPER ENSEMBLE BACKS UP THE TIMING UNCERTAINTY WITH THE NOGAPS
ALSO PREFERRING A SLOWER SOLUTION. AS A RESULT...CHOSE TO KEEP CHC
MENTION OF PRECIP FOR MONDAY AS IT IS STILL NOT CLEAR IF WE WILL
HAVE A FRONTAL PASSAGE...A STRONG STORM AFFECTING THE AREA...OR A
WEAK WAVE JUST CLIPPING US OFF TO THE SOUTH.

REST OF THE WEEK IS MORE TYPICAL WINTER TYPE FLOW...THOUGH
AGAIN...NOT TERRIBLY COLD FOR THE TIME OF YEAR. CLOUDS AND CHC POPS
FOR SHOWERS OF RAIN OR SNOW OVER NWRN HIGHER TERRAIN AND AREAS
DOWNWIND OF THE LAKE. ANOTHER WAVE APPROACHES FOR LATE WEEK WITH A
CHANCE OF WARM ADVECTION PRECIP AGAIN.

NEW MRF ENSEMBLE SHOWS STRONG POS ANOMALY CENTERED OVER GREENLAND AS
PATTERN TAKES ON NAO LOOK...BUT PROG STILL FAILS TO TRANSLATE THAT
INTO ANY REAL SIGNIFICANT ERN US COLD OR STORMINESS. BUT THIS IS THE
FEATURE WE WOULD LIKE TO SEE IF THE WINTER HAS ANY HOPE OF TURNING
INTO AN INTERESTING ONE FOR FELLOW MEMBERS OF MY PROFESSION.

.CTP...NONE.

DANGELO/LA CORTE