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000
FXUS61 KCTP 070327
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1020 PM EST THU MAR 6 2014

.SYNOPSIS...
STRONG CANADIAN HIGH PRESSURE TO OUR NORTH WILL KEEP UNSEASONABLY
COLD AND DRY CONDITIONS IN PLACE ACROSS THE COMMONWEALTH TONIGHT.
THE HIGH WILL MOVE OFFSHORE FRIDAY ALLOWING FOR SOME SLIGHTLY HIGHER
TEMPERATURES THIS FIRST HALF OF THE WEEKEND...WITH DAYTIME HIGHS
REACHING SEASONAL NORMALS FOR THE FIRST TIME IN SEVERAL WEEKS. A
COLD FRONT WILL DROP ACROSS THE REGION SATURDAY NIGHT AND SUNDAY
BRINGING SCATTERED RAIN AND SNOW SHOWERS. DRY AND SEASONABLE WEATHER
RETURN FOR MONDAY.

&&

.NEAR TERM /UNTIL 7 AM FRIDAY MORNING/...
1034 MB HIGH ALONG THE COAST OF MAINE LATE THIS EVENING IS SUPPLYING
DRY LOW TO MID LEVEL AIR ACROSS THE REGION...WHILE A SHIELD OF THICK
CIRROSTRATUS CLOUDS COVERS THE SE HALF OF THE CWA.

LLVL EAST TO SERLY FLOW WILL START TO ADVECT MOISTURE IN FROM THE
ATLANTIC AND HELP TO FORM A NWWD EXPANDING STRATO CU DECK DURING THE
PREDAWN HOURS ACROSS THE SCENT MTNS AND LOWER SUSQ VALLEY. THE FAR
NRN ZONES WILL STAY MAINLY CLEAR SKIES WITH THINNER HIGH CLOUDS
THROUGH MOST OF THE NIGHT.

THE NCENT AND NW MTNS WILL SEE THE COLDEST TEMPS TONIGHT...THANKS TO
THE THINNER HIGH CLOUDS...THE ABSENCE OF LOW CLOUDS...AND SFC
DEWPOINTS IN THE 0 TO -5F RANGE. MINS IN THE UPPER SINGLE DIGITS TO
LOWER TEENS LOOK IN GOOD SHAPE UP NORTH. ELSEWHERE...TEMPS AT
SUNRISE FRIDAY WILL BE IN THE MID TEENS TO LOWER 20S.

DURING THE EARLY TO MID MORNING HOURS...THERE`S JUST A
SLIGHT CHC FOR SOME SNIZZLE OR PATCHY -FZDZ INVOF THE LAUREL
HIGHLANDS THANKS TO THE GREATEST OROGRAPHIC COMPONENT OF THE MOIST
SERLY UPSLOPE FLOW.

&&

.SHORT TERM /7 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
SFC HIGH WILL STILL BE IN CONTROL OF OUR LOCAL WEATHER DURING THE
DAY FRIDAY. THE DRY AIR ABOVE THE INVERSION CAN BE TAPPED AGAIN BY
THE MIXING CREATED BY THE ALMOST EQUINOX-LEVEL SUN STRENGTH/ANGLE.
THUS...HAVE BROKEN THE CLOUDS UP OVER LOTS OF THE AREA ON FRIDAY.
WHICH SHOULD ALLOW FOR A HALF-WAY NORMAL TEMPERATURE.

WILL CONTINUE TO PLAY TEMPS A LITTLE COOLER /AND CLOUDIER/ THAN
MIDDLE OF THE ROAD GUIDANCE FOR FRIDAY. MAX TEMPS WILL BE MAINLY IN
THE LOWER TO MIDDLE 30S...BUT COULD SPIKE UP TO NEAR 40F ACROSS
PARTS OF THE MID SUSQ VALLEY AND FAR NW ZONES...WHERE CLOUD COVER
WILL BE THINNEST...COMBINED WITH A 5-10 KT SERLY DOWNSLOPE FLOW AT
LLVLS.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
AN ACTIVE SPLIT FLOW JET STREAM PATTERN IS FORECAST TO DOMINATE
NORTH AMERICA DURING THE LONG TERM PERIOD. A FAST MOVING NRN STREAM
JET WILL SEND SEVERAL COLD FRONTS AND REINFORCING SHOTS OF COLD AIR
INTO THE NORTHEAST DURING THE PERIOD. THE ACTIVE SRN STREAM HOWEVER
WILL LIMIT THE MOISTURE AVAILABLE FOR THE FROPAS...THUS MOST OF THE
PERIOD LOOKS BE COLD AND DRY.

THE FIRST NRN STREAM COLD FRONT WILL CROSS PA ON SAT AND POSSIBLY
STALL OVER THE DELMARVA ON SUNDAY. THE SECOND FRONT APPROACHES LATE
ON TUESDAY.

THE FIRST SRN STEAM WAVE...NOW PRODUCING WINTRY WEATHER OVER
TEXAS...WILL LIFT TO THE CAROLINA COAST FRIDAY. THIS SYSTEM SHOULD
NOT MOVE FAR ENOUGH NORTH TO IMPACT WEATHER OVER PA. A SECOND
PRONOUNCED WAVE IN THE SRN STREAM WILL MOVE ACROSS THE SRN PLAINS
EARLY NEXT WEEK. INDICATIONS CONTINUE TO SUGGEST THE POTENTIAL FOR
CYCLOGENESIS OVER THE SRN APPALACHIANS NEXT TUESDAY INTO
WEDNESDAY...WITH SOME MEDIUM RANGE GUIDANCE SHOWING SIGNIFICANT
SNOWFALL NWD INTO CENTRAL PA. HAVE INCLUDED WIDESPREAD HIER CHANCE
POPS AT THIS POINT WITH SOME INCREASED LEVEL OF CONFIDENCE...BUT
STILL GIVEN THE OBVIOUS LEVEL UNCERTAINTY AT THIS TIME FRAME.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
A RIDGE OF HIGH PRESSURE WILL REMAIN OVER PENNSYLVANIA THROUGH
FRIDAY...RESULTING IN A HIGH CONFIDENCE OF DRY WEATHER AND LIGHT
WINDS. THE MAIN AVIATION CONCERN WILL BE THE POSSIBILITY OF SOME
LOWER CIGS WORKING INTO SOUTHERN PA...THE RESULT OF AN INCREASINGLY
MOIST SERLY FLOW. THE AIR MASS OVER CENTRAL PA IS INITIALLY VERY
DRY THIS EVENING...SO THERE IS NO EXPECTATION OF ANYTHING BUT VFR
CONDS THRU 06Z. HOWEVER...MDL DATA INDICATES THERE WILL BE ENOUGH
MOISTENING OF THE SFC-1KM LAYER FOR THE POSSIBILITY OF MVFR CIGS
DEVELOPING ACROSS SOUTHERN PA BY ARND DAWN. BASED ON LATEST MDL
OUTPUT...CONFIDENCE OF MVFR CIGS ACROSS SOUTHERN PA IS ABOUT 50
PCT.

ANY STRATOCU THAT DOES WORK INTO SOUTHERN PA COULD POTENTIALLY
LAST FOR A GOOD PORTION OF THE DAY...DUE TO LACK OF MIXING UNDER
SFC RIDGE AND VEIL OF HIGH CLOUDS.

OUTLOOK...
SAT...EARLY AM FOG POSSIBLE. EVENING LOW CIGS POSS W MTNS.
SUN-TUE...NO SIG WX EXPECTED.

&&

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

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...DEVOIR/GARTNER
AVIATION...FITZGERALD