Skip Navigation Linkswww.nws.noaa.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service Forecast Office   NWS logo - Click to go to the NWS homepage
State College, PA banner image
 
 

Area Forecast Discussion
Latest Versions  [Current][-1][-2][-3][-4][-5][-6][-7][-8][-9]



000
FXUS61 KCTP 260449
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1149 PM EST TUE NOV 25 2014

.SYNOPSIS...
HIGH PRESSURE WILL RETREAT TO THE NORTHEAST TONIGHT. LOW PRESSURE
FORMING OFF THE SOUTHEAST COAST WILL DEEPEN SIGNIFICANTLY AS IT
MOVES NORTHEASTWARD ALONG THE EAST COAST ON WEDNESDAY...BRINGING
SIGNIFICANT SNOW TO MUCH OF CENTRAL PENNSYLVANIA. ANOTHER SHOT OF
COLDER AIR WILL FOLLOW FOR THE END OF THE WEEK...BEFORE
TEMPERATURES MODERATE OVER THE WEEKEND AND INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LITTLE CHANGE TO THE GOING FORECAST THIS EVENING. HIGH PRESSURE
CENTERED ALONG THE IL/IN BORDER BUILDING EASTWARD THROUGH THE
OHIO VALLEY WITH RIDGE AXIS EXTENDING NEWD ALONG THE LAKE ERIE
SHORELINE TO LAKE ONTARIO. STRATUS IS PACKED AGAINST THE
ALLEGHENIES OVER NORTHWEST PA. MID AND HIGH CLOUDS HAVE OVERTAKEN
THE REMAINDER OF CENTRAL PA THIS EVENING...AND WILL BE THICKENING
AS THE NIGHT WEARS ON. TEMPERATURES HAVE FALLEN TO THE LOWER 30S
IN MOST PLACES AND WILL DROP A FEW MORE DEGREES ACROSS THE NORTH.

STAGE IS SET FOR A LIGHT TO MODERATE SNOWFALL ACROSS A GOOD PART
OF CENTRAL AND EAST CENTRAL PA. MINOR ADJUSTMENTS TO SNOWFALL MAP
THIS EVENING FOR QUICKER EXIT OF SNOWFALL WEDNESDAY AFTERNOON...
AND SLIGHTLY LESSER QPF ALONG THE WESTERN EDGE OF THE WARNINGS.
HRW-ARW SUGGESTS ACCUMULATING SNOWFALL IS OVER BY 21Z...EVEN
ACROSS THE EAST...AND IS THE MOST AGGRESSIVE IN PUSHING THE
ACCUMULATING SNOWFALL OUT OF MY CWA WED AFTERNOON. HAVE NUDGED
THINGS IN THAT DIRECTION...AS OTHER GUIDANCE IS ALSO FASTER...BUT
MAINTAINED A BLEND OF GUIDANCE MID TO LATE AFTERNOON.

FOR THE OVERNIGHT...PRECIP OVERSPREADING THE SOUTHERN TIER
COUNTIES QUICKLY AFTER 08Z...WITH QPF APPROACHING A TENTH OF AN
INCH BY 12Z. TEMPS ALOFT AND ON THE SURFACE SUGGEST THAT PRECIP
STARTING OVER SOUTHERN /ESPECIALLY SE/ AREAS LATE TONIGHT WILL
LIKELY BE AT LEAST A MIX OF RAIN AND SNOW WITH LIGHT SNOW ON THE
NORTHERN EDGE. SIMPLY...PRECIP WILL MOVE INTO SOUTHERN HALF OF CWA
BEFORE SUNRISE AND WILL BE LIGHT...BUT QUICKLY INTENSIFY DURING
THE MORNING RUSH HOUR ACROSS THE SOUTH.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WINTER STORM WARNINGS/ADVISORIES NOW IN EFFECT.

A LOW PRESSURE SYSTEM DEVELOPS AND INTENSIFIES AS IT TRACKS FROM
THE CAROLINA COAST AT 12Z WED TO OFF THE NJ COAST BY 00Z THU...
BRINGING BIGGEST IMPACTS TO CENTRAL PA DURING THE DAY WED.

CONFIDENCE IS GROWING IN THE STORM TRACK WITH GFS COMING IN LINE
WITH THE ECMWF CLOSER TO THE COAST...WHICH WILL PUSH THE QPF
SHIELD A BIT FURTHER WEST. PRECIP WILL BE ONGOING IN THE SOUTH BY
SUNRISE...AND SPREADING QUICKLY INTO THE CENTRAL AND NORTHEAST BY
MID MORNING. ANY RAIN WILL QUICKLY CHANGE TO SNOW IN THE SE AS
COLUMN COOLS. PERIOD OF HEAVIEST INTENSITY PRECIP WILL BE WED
MORNING THROUGH MID AFTERNOON...WHERE SNOW RATES COULD BE 1-2
INCHES PER HOUR IN THE WARNING AREA. LATEST WWD GRAPHICS CONTINUE
TO SHOW A SWATH OF 6-8 SNOWS OVER THE SERN 1/3 OR SO OF MY FCST
AREA. CONFIDENCE FOR SIG SNOWS UP INTO CENTRAL/NW PA NOT AS HIGH
GIVEN THE LACK OF A SIG EASTERLY LOW LEVEL WIND ANOMALY IN THE
ENSEMBLES...AND A SHORTWAVE SLIDING IN FROM THE WEST WHICH MAY
SHARPEN GRADIENT OF SNOW. BUT FOR A COUPLE INCHES OF SNOW AND
IMPACTS ON THE BUSIEST TRAVEL DAY OF THE YEAR WE STRUNG AN
ADVISORY OVER THE NORTHERN EDGE OF THE WARNING AREA. 

SNOW SHOULD TAPER OFF QUICKLY BY LATE WED AFT/WED EVE AS STORM 
QUICKLY MOVES INTO NEW ENGLAND. FLOW TRANSITIONS BACK TO A NW FETCH 
ACROSS THE LAKES...WITH LIGHT SCT SNOW SHOWERS POSS BY THU MORNING 
IN THE UPSLOPE OF THE WESTERN HIGHER TERRAIN.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
UPPER TROFFING OVER THE EASTERN THIRD OF THE COUNTRY AT THE START
OF THE LONG TERM PERIOD IS FORECAST TO FLATTEN OUT INTO AN
EXTENSIVE WEST TO EAST ZONAL FLOW PATTERN COVERING MUCH OF NORTH
AMERICA. HEIGHTS OVER THE NORTHEASTERN U.S. ARE THEN FORECAST TO
RISE FROM LATE IN THE WEEKEND ONWARD AS THE CABOOSE IN THE CURRENT SHORTWAVE
TRAIN EXITS THE EAST COAST ON FRIDAY AND ENERGY APPROACHING THE
PACIFIC COAST CLOSES OFF AND BUILDS HEIGHTS OVER THE WESTERN AND
CENTRAL U.S.

A SHOT OF COLD AIR WILL MOVE INTO THE REGION FOR THURSDAY AND
FRIDAY BEHIND THE AFOREMENTIONED CABOOSE SHORTWAVE. THIS WAVE MAY
ALSO SUPPORT AN AREA OF PCPN MOVING WEST TO EAST ACROSS THE STATE
THANKSGIVING DAY. ADDITIONALLY...THIS PUSH OF ENERGY/COLD AIR
SHOULD GENERATE THE USUAL POST FRONTAL LAKE AND OROGRAPHICALLY
ENHANCED SNOW SHOWERS IN THE WAKE OF THE DEPARTING STORM SYSTEM
WITH WESTERN AND NORTHERN AREAS SEEING THE BEST CHANCE OF
SCATTERED LIGHT SNOWS...WHILE THE REST OF THE REGION SEES LITTLE
OR NO SNOW SHOWER ACTIVITY AT ALL.

A BROAD WSW FLOW ALOFT ASSOCIATED WITH THE RISING HEIGHTS WILL
MAKE THIS COLD SHOT TEMPORARY WITH WARMER AIR BEGINNING TO MAKE A
RETURN BY SATURDAY. HIGHS WILL RETURN TO NEAR OR EVEN A TICK ABOVE
NORMAL BY THE WEEKEND BEFORE COOLER AIR APPROACHES AGAIN FOR EARLY
NEXT WEEK.

A FRONTAL SYSTEM IN ADVANCE OF THE WARM AIR WILL MOVE ACROSS THE
STATE ON SUNDAY...BRINGING THE BEST CHANCE OF PCPN DURING THE
PERIOD.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
26/03Z UPDATE...MINOR CHANGES TO ONSET OF PCPN. PROJECTED ONSET
MAY BE A BIT FAST WITH THE LATEST HRRR FAVORING THE 12-15Z WINDOW
ACROSS THE SRN AIRFIELDS. MDL SOUNDINGS AND HIGH RES GUIDANCE
STILL SHOW RELATIVELY QUICK CHANGEOVER FROM RAIN-TO-SNOW OVER THE
SE TERMINALS WITH ALL SNOW PTYPES EXPANDING NWD TO FIG-IPT LINE BY
15Z. FINALLY...BFD REMAINS ON EDGE OF LOW CLOUDS AND MVFR CIGS
ACROSS NE OH/NW PA INTO WRN NY. 

26/00Z...LOW PRESSURE DEVELOPING OFF THE SOUTHEAST COAST LATE
TONIGHT WILL STRENGTHEN AS IT LIFTS NWD JUST OFF THE EAST COAST
THROUGH WED NGT. EXPECT RAPIDLY DETERIORATING CONDS FROM SOUTH TO
NORTH DURING THE PREDAWN AND EARLY MORNING HOURS AS SNOW
OVERSPREADS THE AIRSPACE. PCPN WILL LKLY BEGIN AS A MIX IN THE
MDT/LNS AREA BEFORE CHANGING TO ALL SNOW. MOST INTENSE SNOWFALL
RATES AND REDUCED VSBYS WILL BE OVER THE SERN AIRSPACE WITH RATES
UP TO 2"/HR WITH FLGT CATS AOB AIRFIELD MINS. HIGH CONFIDENCE IN
WIDESPREAD IFR CONDS DUSK-DAWN BEFORE SNOW ENDS FROM SW TO NE BY
WED NGT. LOW CIGS SHOULD PERSIST OVER THE WRN 1/3 OF THE AREA WED
NGT WITH MARGINAL IMPROVEMENT ELSEWHERE.

OUTLOOK...

THU...IFR/MVFR WITH OCNL -SHSN WRN 1/3. VFR TO MVFR CIGS
CNTRL/EAST.

FRI...AM MVFR/-SHSN NW...OTHERWISE BCMG VFR. 

SAT-SUN...MAINLY VFR. -SHRA PSBL.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 3 AM WEDNESDAY TO 4 AM EST THURSDAY 
FOR PAZ019-042-045-046-049>053.
WINTER WEATHER ADVISORY FROM 3 AM WEDNESDAY TO 4 AM EST 
THURSDAY FOR PAZ012-017-018-037-041.
WINTER STORM WARNING FROM 3 AM WEDNESDAY TO MIDNIGHT EST 
WEDNESDAY NIGHT FOR PAZ024>028-033>036-056>059-063>066.

&&

$$
SYNOPSIS...RXR/STEINBUGL
NEAR TERM...DEVOIR/RXR
SHORT TERM...RXR
LONG TERM...LA CORTE/GARTNER
AVIATION...STEINBUGL



National Weather Service
Disclaimer Privacy Policy