-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 121517
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1117 AM EDT WED MAR 12 2014

.SYNOPSIS...
A STRONG LATE-WINTER STORM WILL IMPACT THE AREA TODAY...FOLLOWED
BY COLD AND BLUSTERY CONDITIONS WITH WELL-BELOW NORMAL
TEMPERATURES FOR THURSDAY. TEMPERATURES WILL REBOUND TO NEAR
SEASONAL LEVELS FRIDAY INTO THE WEEKEND...AHEAD OF A FRONTAL
SYSTEM PUSHING SOUTHEAST FROM THE GREAT LAKES. THIS FRONT MAY
PRODUCE SOME RAIN OR SNOW SHOWERS ON SATURDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...

-- Changed Discussion --
UPDATED ALL NEAR TERM GRIDS WITH CURRENT CONDITIONS AND NUDGED
FORECAST TO CURRENT DATA.

IN CENTRAL AND NORTHERN AREAS HAD TO LOWER TEMPERATURES AS WITH
RAIN COOLED TO WET BULB. THIS IN TURN IS REINFORCING LOW-LEVEL
COLD AIR DAMMING EFFECT...LOWERED WINDS AND WIND GUSTS UNTIL
CLOSER TO COLD FRONTAL AND CYCLONE TIME PERIOD.

BOUNDARY FOR RAIN/SNOW TRANSITION STILL MAINLY OVER NY AND SLOWLY
WORKING INTO EXTREME NORTHWESTERN PA. BRADFORD STILL HAS SEVERAL
HOURS OF RAIN TO GO. EXPECT SNOW TRANSITION TO CREEP INTO NORTHERN
TIER IN THE 11 AM TO 1 PM TIME-FRAME. RADAR SHOWS EVOLVING SNOW
BAND IN NE OH NOW WITH BLOSSOMING AREA ON IR. SNOW THIS AFTERNOON
IN NW SHOULD TRANSITION RAPIDLY TO ACCUMULATING SNOW AND SUDDEN
DROP OF TEMPERATURES WITH RAIN WASHING OFF SALT AND ANTI-SKID
MATERIALS WILL BE AN ON ROADS.

THE RAIN AND SHOWERS WILL BE SLOW TO GET INTO THE SOUTHEASTERN
AREAS UNTIL LATER THIS AFTERNOON. MOST GUIDANCE STILL SHOWS THE
WARM AIR CREEPING INTO THE SOUTHEAST PEAKING AROUND 60...THOUGH
NEWER GUIDANCE IS SLIGHTLY COLDER. AREAS WHERE IT RAINS WILL FALL
TO THE WET-BULB FAST.

THE FRONT HAS A GOOD MOISTURE SURGE AND HIGH WIND SURGE...ANY
CONVECTION IN SOUTHERN AND S. CENTRAL PA WILL HAVE SOME STRONG
WINDS TO DEAL WITH. POTENTIAL THUNDER AND PERHAPS ISOLATED HIGH
WIND ISSUES IN SE AREAS. TO ADD TO THIS THERE IS A FRONTAL
BOUNDARY IN SE PA DUE TO THE RESIDUAL COLD AIR DAMMING WHICH SHOWS
UP IN THE 925 TO 1000 HPA THETA-E.

SNOW ACCUMULATIONS IN NORTHERN AREAS WILL BE FAST THIS AFTERNOON
AND SHOULD BE OVER EARLY THIS AFTERNOON. BULK OF SNOW SHOULD FALL
BY EARLY EVENING.

WINDS WILL BE A MORE SIGNIFICANT ISSUE ON COLD SIDE OF THE FRONTAL SYSTEM.

THE RAIN...SNOW MELT AND ICE ON SOME RIVERS AND STREAMS COULD
CAUSE SOME MINOR FLOOD ISSUES.
-- End Changed Discussion --

&&

.SHORT TERM /THURSDAY/...

-- Changed Discussion --
WELCOME TO WINTER...FOR A DAY.

AS THE FRONT RACES ACROSS THE STATE OVERNIGHT AND INTO THE MORNING
THURSDAY TEMPERATURES WILL FALL LIKE A STONE AND IT WILL BE WINDY.
THIS WILL CAUSE WIND CHILL ISSUE IN N. CENTRAL AREAS. CORE OF
STRONGEST WINDS APPEARS TO COME OVERNIGHT AND DIMINISHES DURING
THE DAY THURSDAY.

GOING TO BE A COLD BLUSTERY START TO THE MORNING THURSDAY. THE 850
HPA TEMPS BOTTOM OUT -18 TO -20 A FEW HOURS EITHER SIDE OF 8 AM SO
WILL BE A VERY COLD DAY FOR MID-MARCH. THE 850 HPA TEMPS REBOUND
TO -14C BY EVENING AND KEEP RISING.

THE SREF AND NAME SUGGEST THAT THE STRONGEST WINDS COME THROUGH
IN THE 10PM TO 3 AM RANGE TONIGHT BUT STAY STRONG THROUGH AT LEAST
NOON THURSDAY. WINDS SHOULD BEGIN TO SUBSIDE THURSDAY AFTERNOON
AND EVENING.

PRIMARILY A COLD AND WINDY DAY. COULD SEE SOME CLOSE TO RECORD LOW
HIGH TEMPERATURES IF THE TEMPERATURES DO NOT RISE AFTER MIDNIGHT
INTO FRIDAY AM.
-- End Changed Discussion --

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE GOOD NEWS IS THAT THE COLD BLAST WILL BE SHORT-LIVED...WITH A
RAPID MODERATION OCCURRING ON FRIDAY. BREEZY SW RETURN FLOW IN
ADVANCE OF NRN CLIPPER SFC LOW TRACKING ACRS THE UPPER GREAT LAKES
AND DOWNSLOPING SHOULD HELP TO BOOST TEMPS INTO THE 40S NORTH AND
50S SOUTH. THE MODELS TURN THE LOW TO THE NORTHEAST UP THE ST.
LAWRENCE VLY ON DAY 5/SAT...DRAGGING A TRAILING/WEAK COLD FRONT
ACRS THE NORTHEAST AND MID-ATL STATES. MODEL CONSENSUS INDICATES
SOME LGT PCPN IS POSSIBLE WITH CHC POPS AS THE FRONT SHIFTS SEWD
ACRS THE CWA.

GEFS/EC ENSEMBLE MEANS SHOW THE LARGE SCALE PATTERN REVERTING BACK
TO A WRN RIDGE/ERN TROUGH CONFIGURATION INTO EARLY NEXT WEEK. THIS
HAS BEEN THE FAVORED/PREVAILING FLOW REGIME THIS WINTER...WITH A
COLD POLAR VORTEX OVER EASTERN CANADA. A STRONG SFC HIGH PUSHING
SEWD FROM THE UPPER MS VLY SHOULD DIRECT COLDER AIR INTO THE REGION
BEHIND A REINFORCING FROPA ON SUNDAY...WITH TEMPS LKLY TRENDING
LOWER BY DAY 7/MON. THE NON-NCEP OPRNL MODELS /12Z CMC AND ECMWF/
ARE MORE BULLISH ON CYCLOGENESIS INVOF THE GULF STREAM JUST EAST
OF THE CAROLINAS...WITH THE NW EDGE OF POTNL PCPN SHIELD POSSIBLY
REACHING SRN/SERN PA ON ST. PATRICK`S DAY. CONFIDENCE IS LOW GIVEN
THE LARGE SPREAD BTWN THE GFS AND ECMWF/CMC. SOMETHING TO MONITOR
IN THE DAYS TO COME.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
CONDITIONS NOW IFR ACROSS THE NW. STEADIER RAIN ACROSS THE NW.

EXPECT CONDITIONS TO TO GO DOWN HILL ACROSS THE REST OF THE
AREA...AS RAIN BECOMES MORE WIDESPREAD.

THE BIG CONCERN IS STRONG WINDS AND LLWS...ALONG WITH HEAVY
RAIN...AND PERHAPS SOME STRONG TO SEVERE THUNDERSTORMS ALONG
THE MD LINE. ALSO SNOW ACROSS THE NORTH BY AFT.

THEN TONIGHT THE CONCERN IS STILL STRONG WIND GUST...RAPID DROP
IN TEMPS...AND MORE SNOW.

THU WILL STILL FEATURE GUSTY WINDS...AS A DEEP STORM PULLS
AWAY FROM THE AREA.

OUTLOOK...
THU...STRONG/GUSTY N/NW WINDS...GRADUALLY DIMINISHING IN
THE AFTERNOON.
FRI-SUN...NO SIG WX EXPECTED.

&&

.HYDROLOGY...
WITH WARMER TEMPERATURES RAINFALL TODAY...WE EXPECT MODERATE
RISES ON RIVERS AND STREAMS. THERE IS STILL ENOUGH ICE IN SPOTS TO
LEAD TO ICE JAMS...THOUGH SIGNIFICANT DECAY HAS OCCURRED AT MANY
LOCATIONS DUE TO THE RECENTLY WARM WEATHER. ANY ICE JAMS WILL BE
ISOLATED IN NATURE. MONITOR WATER LEVELS CLOSELY FOR THE REST OF
THE WEEK.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON EDT THURSDAY
FOR PAZ004>006-010>012-017-018-024-033-037-041-042.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 8 AM EDT
THURSDAY FOR PAZ017-024-033.
WIND ADVISORY FROM 5 PM THIS AFTERNOON TO NOON EDT THURSDAY
FOR PAZ025>028-034>036-056>059-063>066.
WINTER WEATHER ADVISORY UNTIL 8 AM EDT THURSDAY FOR PAZ006-010-
011-037.
WINTER STORM WARNING UNTIL 8 AM EDT THURSDAY FOR PAZ004-005.

&&

$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...GRUMM
SHORT TERM...GRUMM/DANGELO
LONG TERM...STEINBUGL
AVIATION...MARTIN
HYDROLOGY...