Area Forecast Discussion
Issued by NWS State College, PA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KCTP 162007 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 307 PM EST TUE DEC 16 2014 .SYNOPSIS...
-- Changed Discussion --
SEASONAL TEMPERATURES WILL RETURN BEHIND A COLD FRONT WHICH WILL PASS THROUGH THIS EVENING. SCATTERED MOUNTAIN SNOW SHOWERS ARE THEN EXPECTED FOR MID AND LATE WEEK. CONFIDENCE IS LOW CONCERNING ALL DETAILS AND POTENTIAL IMPACTS ASSOCIATED WITH A LOW PRESSURE SYSTEM EXPECTED TO TRACK NORTHEAST FROM THE GULF COAST STATES OFF THE EAST COAST THIS WEEKEND.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
-- Changed Discussion --
AREA OF MODERATE RAIN PUSHING EAST OF CWA AT 20Z...THOUGH ADDITIONAL LIGHTER SHOWERS WILL CONTINUE TO REDEVELOP ACROSS EASTERN HALF OF CWA INTO EARLY/MID EVENING. ACROSS THE WEST...PROXIMITY TO UPPER WAVE AND COLD/OCCLUDED FRONT PUSHING SLOWLY EASTWARD WILL BRING INCREASING SHOWER ACTIVITY BACK INTO WESTERN PORTIONS OF CWA OVER NEXT SEVERAL HOURS WHICH WILL CONTINUE THROUGH THE OVERNIGHT. BEHIND THE FRONT AS WINDS TRANSITION TO A SW DIRECTION...PRECIP WILL BECOME CONFINED TO HIGHER ELEVATIONS OF THE WEST AND NORTH...ENHANCED BY OROGRAPHIC FLOW AND INCREASING WIND SPEEDS. PLUS...AS COLDER AIR GRADUALLY FILTERS IN OVERNIGHT...PRECIP WILL TRANSITION OVER TO LIGHT SNOW SHOWERS. TEMPERATURES TONIGHT WILL LINGER NEAR LATE AFTERNOON VALUES FOR A WHILE...BEFORE DROPPING INTO THE 30S AREAWIDE AFTER MIDNIGHT.
-- End Changed Discussion --
&& .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
-- Changed Discussion --
BY WED MORNING...INCREASING WESTERLY FLOW ASSOCIATED WITH A TROUGH SLIDING EASTWARD FROM THE GREAT LAKES WILL BRING COOLER AIR AND SCT SNOW SHOWERS TO THE REGION. MOISTURE PULLED AROUND THE SYSTEM AND PULLED FROM THE GREAT LAKES WILL ASCEND THE WRN HIGHLANDS BRINGING SCT LIGHT SNOW SHOWERS...AND CONTINUE THROUGH WEDNESDAY NIGHT AS THE UPPER LOW CENTER SLIDES EAST. DOWNSLOPE COMPONENT TO WINDS SHOULD KEEP IT PARTLY TO MOSTLY SUNNY IN THE SE. SOME VERY LIGHT ACCUMS COULD OCCUR ON THE WRN MTS. IT WILL GET BREEZY ON WED - ESP IN THE LAURELS WHERE GUSTS COULD GET INTO THE 30S.
-- End Changed Discussion --
&& .LONG TERM /THURSDAY THROUGH TUESDAY/... A RATHER POTENT SHORTWAVE TROUGH WILL PIVOT EASTWARD FROM THE GREAT LAKES AND CROSS THE AREA WED NGT BEHIND THE DEPARTING SURFACE LOW LIFTING SLOWLY NORTH FROM MAINE INTO NEW BRUNSWICK CANADA. A REINFORCING SHOT OF COLD AIR ALOFT SHOULD ACCOMPANY THE TRAILING SHORTWAVE WHICH MAY ACT TO BRIEFLY ENHANCE POST FRONTAL LAKE EFFECT AND UPSLOPE SNOW SHOWERS OVER THE WESTERN HIGHLANDS. ITS NOT OUT OF THE QUESTION THAT THE STRONG VORTMAX COULD INDUCE SNOW SHOWERS EAST OF THE ALLEGHENY FRONT WED NGT HOWEVER THE GLOBAL MODEL QPFS ARE NOT IN FAVOR OF THIS OUTCOME. DESPITE A WELL ALIGNED WNW FLOW AND FAIRLY STRONG LOW LEVEL COLD AIR ADVECTION...MODEL SOUNDINGS SHOW RATHER SHALLOW MOISTURE/LOW INVERSION HGTS ALONG WITH DRY AIR WHICH SHOULD LIMIT MAX SNOW ACCUM POTENTIAL (POTENTIAL FOR THIS MUCH OR WORST CASE) OVER THE NW MTNS TO 2-3 INCHES BY THU MORNING...WITH AROUND 1 INCH ACCUM THE MOST LIKELY OUTCOME. OVERALL THE GENERAL WEATHER TREND IN CENTRAL PA WILL BE TOWARD A BRISK AND COLDER PATTERN WED THRU FRI. LARGE SCALE SUBSIDENCE ASSOCIATED WITH SURFACE HIGH EXTENDING FROM THE GREAT LAKES INTO EASTERN CANADA SHOULD BRING AN END TO NUISANCE SNOW SHOWER ACTIVITY BY FRI NGT. CONCERNING THE POTENTIAL WEEKEND STORM... THERE IS BROAD MODEL CONSENSUS IN A SURFACE LOW DEVELOPING OVER THE GULF COAST REGION AND TRACKING NORTHEAST OFF THE EAST COAST THIS WEEKEND. HOWEVER...THERE CONTINUES TO BE A WIDE RANGE OF POSSIBLE SOLUTIONS WITH ABOVE AVERAGE SPREAD IN THE LOW TRACK. IN ADDITION TO THE LARGE SPREAD...THERE HAVE BEEN RUN-TO-RUN [IN]CONSISTENCY ISSUES THAT CONTINUE TO PLAGUE THE MODEL FCSTS IN PARTICULAR TODAYS 15/12Z RUN OF THE DETERMINISTIC ECMWF WHICH HAS BACKED OFF ON ITS BULLISH WINTER STORM SCENARIO THAT IT HAS BEEN ADVERTISING FOR THE PREVIOUS 4 CYCLES. CURIOUSLY BOTH THE GEFS AND ECENS SEEM TO BE LEANING MORE IN FAVOR OF A LOW TRACK CLOSER TO THE COAST - WITH A MEAN POSITION WEST OF THEIR RESPSECTIVE DETERMINISTIC MODEL CORES. WITH THE STORM STILL 5-6 DAYS OUT THERE IS A LOT OF TIME FOR THE FORECAST TO CHANGE. CONFIDENCE IS LOW REGARDING ANY POTENTIAL DETAILS OR IMPACTS WITH THIS SYSTEM. HIGH PRESSURE SHOULD BUILD INTO THE AREA EARLY NEXT WEEK. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
AREA OF MODERATE RAIN PUSHING EAST OF CWA AT 20Z...THOUGH ADDITIONAL LIGHTER SHOWERS WILL CONTINUE TO REDEVELOP ACROSS EASTERN HALF OF CWA INTO EARLY/MID EVENING. ACROSS THE WEST...PROXIMITY TO UPPER WAVE AND COLD/OCCLUDED FRONT PUSHING SLOWLY EASTWARD WILL BRING INCREASING SHOWER ACTIVITY BACK INTO WESTERN PORTIONS OF CWA OVER NEXT SEVERAL HOURS WHICH WILL CONTINUE THROUGH THE OVERNIGHT. WIDESPREAD RESTRICTIONS WILL CONTINUE ACROSS THE ENTIRE CWA THROUGH THIS EVENING...WITH MAINLY IFR CONDITIONS MIXED WITH SOME MVFR. BEHIND THE FRONT AS WINDS TRANSITION TO A SW DIRECTION...PRECIP WILL BECOME CONFINED TO HIGHER ELEVATIONS OF THE WEST AND NORTH...ENHANCED BY OROGRAPHIC FLOW AND INCREASING WIND SPEEDS. PLUS...AS COLDER AIR GRADUALLY FILTERS IN OVERNIGHT...PRECIP WILL TRANSITION OVER TO LIGHT SNOW SHOWERS. RESTRICTIONS OVER THE SE HALF OF CWA WILL GRADUALLY ABATE AS DOWNSLOPE COMPONENT TO WINDS BECOMES ESTABLISHED. OUTLOOK... WED...LOW CIGS/SHSN LIKELY W MTNS. OCNL MVFR CIGS POSS CENTRAL MTNS. VFR SE. THU-FRI...MVFR CIGS POSS NW. OTHERWISE NO SIG WX EXPECTED. SAT-SUN...SNOW/REDUCED VSBY POSS ESP SOUTHERN PA.
-- End Changed Discussion --
&& .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RXR NEAR TERM...RXR SHORT TERM...RXR LONG TERM...STEINBUGL AVIATION...RXR

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.