Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 200838
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
438 AM EDT MON OCT 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL PASS BY JUST SOUTH OF PA TONIGHT. LOW PRESSURE
MOVING ACROSS THE LOWER GREAT LAKES WILL DRAG A COLD FRONT ACROSS
THE AREA ON TUESDAY. A NEW LOW WILL FORM OFF THE MID ATLANTIC
COAST TUESDAY NIGHT AND KEEP BREEZY AND WET CONDITIONS ACROSS THE
AREA INTO WEDNESDAY. CONDITIONS WILL SLOWLY IMPROVE DURING THE
LATTER PART OF THE WEEK...AS THE STORM SLOWLY MOVES AWAY FROM THE
AREA.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EXTENSIVE CIRRUS AND CIRROSTRATUS CONTINUES TO STREAM ACROSS
WESTERN AND CENTRAL PA EARLY THIS MORNING. LATEST IR IMAGERY
SHOWS THE MID AND HIGH CLOUD SHIELD EXTENDING BACK THROUGH CENTRAL
AND SOUTHERN INDIANA...IN ASSOCIATION WITH A WARM FRONT PUSHING
THROUGH THE OHIO VALLEY.

MODEL GUIDANCE INDICATES THE BULK OF THE HIGH CLOUDS FOCUSED OVER
CENTRAL AND SOUTHERN PA THROUGH DAWN. INDEED...A BACK EDGE TO THE
THICKEST MID TO HIGH CLOUD DOES APPEAR TO BE PROGRESSING FROM
NORTHWEST TOWARDS CENTRAL OH. DESPITE THE CLOUDS...MIN TEMPS
SHOULD REACH THE MID TO UPPER 30S ACROSS MOST OF THE ADVISORY
AREA...SO WILL LEAVE FROST ADVISORY IN PLACE THIS MORNING.

EXPECT A MAINLY DRY DAY ACROSS CENTRAL PA...AS TOP DOWN MOISTENING
PERSISTS IN ADVANCE OF THE STORM SYSTEM SPREADING INTO THE CENTRAL
GLAKS. THERE SHOULD BE SOME LATE DAY SHOWERS ACROSS THE
NORTHWEST...BUT THE REMAINDER OF CENTRAL PA WILL REMAIN DRY. HIGHS
SHOULD EASILY REACH THE 50S THROUGHOUT ON A FRESHENING SOUTHWEST
BREEZE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
A PARENT SFC LOW WILL SLOWLY TRANSLATE SOUTHEASTWARD INTO THE
EASTERN GLAKS TONIGHT AS SECONDARY DEVELOPMENT STARTS TAKING PLACE
OFF THE COAST BY LATE TUESDAY. THE RESULT WILL BE CONTINUED
EXTENSIVE CLOUDINESS AND INCREASING CHANCES FOR SHOWERS FROM WEST
TO EAST ACROSS THE STATE. HOWEVER...HIGHEST POPS WILL REMAIN OVER
THE WEST AND ESPECIALLY NORTHWEST THROUGH THE DAY TUESDAY AS
DEEPEST MOISTURE AND BEST LIFT ARE JUXTAPOSED WEST OF THE
ALLEGHENIES INTO THE EASTERN OHIO VALLEY. HIGH TEMPS TUE WILL BE A
TAD MILDER ACROSS THE LOWER SUSQ...AND A TAD COOLER OVER THE
NORTHWEST MOUNTAINS...WITH LITTLE CHANGE IN BETWEEN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
AN UNUSUALLY HIGH DEGREE OF MODEL/ENSEMBLE AGREEMENT IS LEADING
TO A HIGH CONFIDENCE FORECAST FOR MUCH OF THE LONG TERM PERIOD.
THE OVERWHELMINGLY DOMINANT MAIN FEATURE TO AFFECT THE LOCAL AREA
DURING THIS PERIOD WILL BE A CUT-OFF...MEANDERING UPPER LOW AND
IT/S REFLECTION/MINI-ME AT THE SFC. THE DEVELOPMENT TAKES PLACE ON
MONDAY NIGHT AS A COLD FRONT PUSHES THROUGH AND SECONDARY LOW
DEEPENS OVER THE MID-ATLANTIC STATES/COAST. THE SYSTEM WILL ONLY
SLOWLY SLIDE TO THE EAST AND NORTHEAST THROUGH THE PERIOD.

THE POSITION OF THE STORM WILL KEEP LOTS OF MARITIME AIR FLOWING
IN FROM THE NORTH/EAST AND KEEP POPS PRETTY HIGH FROM TUES INTO
WED...AND PERHAPS THURSDAY. THE HIGHEST POPS WILL GENERALLY BE IN
THE NRN HALF - ESP THE NE. BUT THE MOISTURE WILL WRAP AROUND THE
STORM COMPLETELY AT TIMES. THUS...A MOIST UPSLOPE IN THE WRN MTNS
WILL KEEP SHOWER CHCS HIGH THERE AS WELL DURING MID-WEEK. WITH ALL
THE CLOUDS AND WIND...THE PROSPECTS FOR ANY SNOW ARE DIM. 8H
TEMPS GENERALLY STAY WELL ABOVE ZERO. BUT TUES NIGHT/WED AM MAY BE
COLD ENOUGH OVER THE LAURELS TO HAVE SOME SNOW MIX IN WITH THE
SHOWERS ON THE HIGHEST ELEVS. HAVE CHOSEN TO LEAVE OUT MENTIONS
OF ANY MIX AT THIS POINT. THE CORE OF THE COLD AIR IS SHUNTED TO
OUR SOUTH WITH HELP FROM THE CIRCULATION OF THE UPPER LOW...WHICH
KEEPS THAT MARITIME AIR WRAPPING IN TO THE AREA.

EVENTUALLY...SFC HIGH PRESSURE AND CONCURRENT UPPER RIDGING
SHOULD LEAD TO A DRY WEEKEND WITH MILD TEMPERATURES ON SAT. THERE
COULD BE A WEAK AND DRY FRONT DROP ACROSS THE GREAT LAKES AND
MID-ATLANTIC ON SUNDAY...WHICH MAY PRODUCE WIDELY SCT
SHOWERS...BUT IT IS NOT WORTH A POP AT THIS POINT. TEMPS MAY THEN
DIP A FEW DEGS FROM SAT-SUN.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS EXPECTED OVERNIGHT WITH ONLY MID AND HIGH CLOUDS
INVADING THE AREA IN RESPONSE TO WARM AIR ADVECTION. THE CLOUD SHIELD
WILL LIMIT FOG DEVELOPMENT.

FOCUS ON MONDAY WILL SHIFT TOWARD COLD FRONT APPROACHING FROM THE
GREAT LAKES. SCATTERED SHOWERS AHEAD OF THIS FRONT SHOULD SPREAD
INTO THE WESTERN MOUNTAINS LATE IN THE DAY. HOWEVER...WIDESPREAD
VFR CONDITIONSS WILL PERSIST THROUGH DUSK. MVFR WITH OCCASIONAL
IFR CONDITIONS /ESPECIALLY IN THE WESTERN MOUNTAINS/ ARE EXPECTED
MONDAY NIGHT AS SHOWERS OVERSPREAD THE REGION.

OUTLOOK...

TUE-FRI...LOW CIGS POSS W MTNS...MAINLY AT NIGHT/EARLY AM.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR PAZ019-025>028-
034>036-045-046-049>053-056>059-063>066.

&&

$$
SYNOPSIS...DEVOIR/LAMBERT
NEAR TERM...DEVOIR/LAMBERT
SHORT TERM...DEVOIR/LAMBERT/MARTIN
LONG TERM...DANGELO
AVIATION...FITZGERALD/TYBURSKI



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