Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 231509 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 1009 AM EST SUN NOV 23 2014 .SYNOPSIS... LOW PRESSURE WILL MOVE FROM THE CENTRAL PLAINS TO THE WESTERN GREAT LAKES BY MONDAY. A MILDER SOUTHERLY FLOW OF AIR AHEAD OF THE STORM WILL BRING MODERATING TEMPERATURES THIS AFTERNOON AND MONDAY...ALONG WITH A WIDESPREAD RAIN TONIGHT. A COLD FRONT WILL CROSS THE REGION ON MONDAY. AN AREA OF LOW PRESSURE WILL MOVE ALONG THE MID ATLANTIC COAST WEDNESDAY INTO THURSDAY...BRINGING A CHANCE OF SNOW TO EASTERN HALF OF PENNSYLVANIA. ANOTHER SHOT OF COLD AIR WILL FOLLOW FOR NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... 10 AM UPDATE... LIGHT SHRA CROSSING THE NRN TIER MOVING ACROSS AREAS WHICH ARE ABOVE FREEZING...SO PROBLEMS ANTICIPATED THERE. COLDEST TEMPS REMAIN FROM UNV-IPT/SEG...AND IT SHOULD REMAIN DRY THERE. MIXING SHOULD BEGIN TO OCCUR IN THE SOUTHERN VALLEYS AS THE SUN IS AS STRONG AND TEMPS SHOULD GET WELL INTO THE 50S. JST ALREADY 51F. HIGH CLOUDS ARE STILL OFF TO THE SOUTH AND SHOULD ADVNACE NORTHWARD STEADILY BUT NOT GET TOTALLY OPAQUE UNTIL CLOSER TO SUNSET. TWEAKS TO TIMING OF PRECIP ONSET/QPF MADE TO MATCH WITH ONSET TIMING PER NEWEST NEAR TERM MDLS. PREV... SPOTTY LIGHT SHOWERS WILL CONTINUE TO DIMINISH ACROSS THE NORTHERN HALF OF CENTRAL PA THIS MORNING AS LLVL CONVERGENCE IS LOST WITH THE EXIT AND DISSIPATION OF LLVL JET INTO SOUTHERN NEW ENGLAND AND H5 SHORTWAVE RIDGING ARRIVING FROM THE OHIO VALLEY. THE AMPLIFYING UPPER RIDGE WILL BRING SEVERAL HOURS OF FAIR WEATHER TODAY LATER TODAY...ALONG WITH MILDER CONDITIONS...BEFORE SOUTHERN STREAM WAVE OVER SOUTHEAST TX THIS MORNING APPROACHES THE CENTRAL APPALACHIANS THIS EVENING...PUSHING WARM FRONT NORTHWARD INTO THE COMMONWEALTH ON A STRONG 850 MB JET. BEST MOISTURE CONVERGENCE WON`T ARRIVE UNTIL AROUND OR JUST AFT 00Z...AND A SHIELD OF RAIN SHOULD ARRIVE FROM SOUTH TO NORTH BETWEEN 00Z AND 06Z. WARM SECTOR WILL COVER CENTRAL PA LATE TONIGHT INTO MONDAY MORNING...WITH SLOW MOVING COLD FRONT PUSHING INTO FAR WESTERN PA EARLY MONDAY MORNING. BREEZY CONDS WILL BE SEEN IN THE WARM SECTOR...BUT STRONGLY AGEOSTROPHIC STABLE FLOW WILL PRECLUDE THE STRONGEST OF WINDS FROM MIXING TO THE SURFACE. HIGHS TODAY WILL RANGE FROM 45 TO 50 ACROSS THE AREA. MINS TONIGHT WILL RANGE THROUGH THE 40S IN THE WARM SECTOR. && .SHORT TERM /MONDAY/... STEADIEST RAINFALL SHOULD EXIT BY OR SHORTLY PAST 12Z...AS COLD FRONT SLOWLY APPROACHES FROM THE OHIO VALLEY. STRONG WEST TO SOUTHWEST FLOW BEHIND THE FRONT WILL HELP TO MIX DOWN SOME 25 TO 35 MPH GUSTS OVER WESTERN AND NORTHWEST PA. GOOD DOWNSLOPING SHOULD ALLOW AREAS EAST OF THE ALLEGHENIES TO WARM THROUGH THE 50S AND EVEN INTO THE LOWER 60S SOUTH AND EAST. STRONGEST BOUNDARY LAYER COOLING WON`T TAKE PLACE UNTIL MONDAY NIGHT AND TUESDAY. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGHLY AMPLIFIED AND ACTIVE UPPER AIR PATTERN DEVELOPING NEXT WEEK. THE 500MB CONFIGURATION WILL FEATURE ANOMALOUS RIDGING ALONG THE WEST COAST AND IN THE WESTERN ATLANTIC WITH A FULL-LATITUDE TROUGH CARVING OUT OVER THE CENTRAL AND ERN U.S. RETURN OF WESTERLY FLOW BEHIND MONDAY FROPA WILL BRING SOME LIGHT SNOW SHOWERS TO WESTERN HIGHER ELEVATIONS...BUT WSW TRAJECTORY IS NOT FAVORABLE FOR LAKE EFFECT OVER THE NORTHWEST MOUNTAINS. CONFIDENCE IS INCREASING IN COLDER TO BELOW AVG TEMPERATURES HEADING INTO THANKSGIVING AND ESP THE WEEKEND AS THE GLOBAL MODELS AND ENSEMBLES ARE SUGGESTING PERSISTENCE OF THE ERN CONUS MEAN TROUGH. SATURDAY NIGHT/SUNDAY MORNING MODEL GUIDANCE CONTINUES TO SHOW A LARGE DEGREE OF UNCERTAINTY IN THE POTENTIAL IMPACTS OF A WAVE CURRENTLY COMING ONSHORE OVER WESTERN BRITISH COLUMBIA...WHICH IS FORECAST TO SPAWN A COASTAL MID ATLANTIC LOW AND MOVE ALONG OF JUST OFF THE COASTLINE WEDNESDAY INTO THU. THIS SITUATION WILL CONTINUE TO BE WATCHED AS COLD AIR IN PLACE WILL LIKELY BE SUFFICIENT TO SUPPORT SNOW AS PTYPE...AND TRAVEL DISRUPTIONS ARE POSSIBLE ON WEDNESDAY SHOULD SOME OF THE WESTERN TRACK SOLUTIONS VERIFY. 00Z SUN SUITE CONTS TO SHOW GEFS LARGELY FOCUSED ON A MOSTLY OFFSHORE STORM TO AFFECT THE FISHES...WHILE OPERATIONAL ECMWF SHOWS POTENTIAL FOR MORE WIDESPREAD INLAND SNOWFALL IMPACTS ON WEDNESDAY AFTERNOON/NIGHT...ONE OF THE BUSIEST TRAVEL DAYS OF THE YEAR. ANOTHER SHOT OF COLD AIR LOOKS POISED TO ARRIVE FOR NEXT WEEKEND AFTER THE STORM EXITS. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... CURRENTLY ALL TAF SITES ARE VFR AND SHOULD REMAIN SO THROUGH MOST OF THE DAY. BUT MVFR MAY OCCUR FOR THE NEXT FEW HRS AT BFD AS SHRA RUN THROUGH THEM OCCASIONALLY. ANOTHER SYSTEM WILL MOVE IN TONIGHT...WITH PRECIPITATION POSSIBLE AT ALL TAF SITES AFTER 00Z. IFR CONDITIONS ARE POSSIBLE AT THE LOWER SUSQ TAF SITES WITH AT LEAST MVFR IF NOT IFR AT ALL OTHERS...WITH PERIODS OF IFR POSSIBLE. LLWS WILL RETURN AT ALL TAF SITES BETWEEN 01Z AND 05Z AND WILL CONTINUE INTO MONDAY MORNING. OUTLOOK... MON...MVFR/IFR WITH WIDESPREAD RAIN. TUE...MVFR WITH SHSN WEST. VFR ELSEWHERE. WED...IFR IN SN/SNRA EAST. MVFR/IFR IN SN CENTRAL. MVFR/VFR WEST. THU...MVFR/IFR NW IN SHRA/SN. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO/DEVOIR SHORT TERM...DEVOIR LONG TERM...DEVOIR/RXR AVIATION...DANGELO/CERU

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