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 250237 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 937 PM EST WED DEC 24 2014 .SYNOPSIS... AN INTENSIFYING STORM SYSTEM WILL MOVE UP THROUGH THE EASTERN GREAT LAKES THIS EVENING...DRAGGING A COLD FRONT THROUGH THE REGION OVERNIGHT. GUSTY WEST WINDS WILL DEVELOP BEHIND THE FRONT LATE TONIGHT AND THURSDAY. ANOTHER LESS POTENT COLD FRONT WILL MOVE ACROSS THE AREA THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... SHARP COLD FRONT HAS PUSHED EAST OF KPIT AND KERI AS OF 02Z. A FEW LIGHTNING STRIKES AND WGUSTS BTWN 35-45KTS HAVE BEEN REPORTED WITH FROPA ACROSS WESTERN PA. WATER VAPOR LOOP SHOWS UPPER LVL SHORTWAVE LIFTING NE THRU LOWER MICHIGAN EARLY THIS EVENING. GIVEN THIS TRAJECTORY...EXPECT BULK LG SCALE FORCING TO PASS NORTH OF PA. THIS...COMBINED WITH THE MORE STABLE AIR MASS ACROSS CENTRAL PA...SHOULD PRECLUDE A SVR WX THREAT OVR MOST IF NOT ALL OF CENTRAL PA. BEST CHC OF A DAMAGING WGUST WILL BE BTWN 02Z-04Z OVR WARREN CO...WHERE COMBINATION OF SOME MEAGER CAPE AND STRONG FORCING IS EXPECTED. COLD FRONT SHOULD BE ACCOMPANIED BY SHOWERS OVR MOST OF THE AREA LATER TONIGHT. HAVE PLACED THE HIGHEST POPS ACROSS THE NW MTNS AND SUSQ VALLEY...WHERE POSITIVE PWAT ANOMALIES THE HIGHEST. IT WILL BE AN UNSEASONABLY MILD CHRISTMAS EVE...AS THE REGION REMAINS WITHIN DEEP SOUTHERLY FLOW AHEAD OF GRT LKS LOW PRES SYSTEM. AREAS OF DRIZZLE AND FOG WILL PRECEDE THE ARRIVAL OF THE FRONTAL SHOWERS...WHICH SHOULD ARRIVE OVR THE SUSQ VALLEY JUST AFTER MIDNIGHT. BEST CHC OF THUNDER WILL BE LATE THIS EVENING ACROSS THE NW MTNS CLOSEST TO PATH OF MID LVL SHORTWAVE. HOWEVER...CAN/T COMPLETELY RULE OUT A RUMBLE FURTHER SE WITH FROPA. ALTHOUGH THE THREAT OF ISOLATED SVR WX WILL BE CONFINED TO THE NW MTNS...SOME FAIRLY STRONG GUSTS WILL MIX TO THE SFC IMMEDIATELY FOLLOWING FRONTAL PASSAGE OVERNIGHT. LATEST BUFKIT SOUNDINGS SUPPORT GUSTS TO BTWN 40-45KTS OVR THE ALLEGHENY PLATEAU...WITH SLIGHTLY LOWER GUST POTENTIAL FURTHER EAST. STEADY OR SLOWLY RISING TEMPS EXPECTED OVERNIGHT UNTIL FRONT ARRIVES. BY DAWN...THE FRONT WILL HAVE CLEARED THE ENTIRE STATE AND TEMPS SHOULD RANGE FROM THE M30S OVR THE ALLEGHENY MTNS...TO THE M40S ACROSS THE SUSQ VALLEY. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... CHRISTMAS DAY WILL BRING A TRANSITION INTO A PRETTY TYPICAL POST FRONTAL COOL SEASON PATTERN...WITH CLOUDS AND BLUSTERY GUSTY WESTERLY WINDS. HIGHER ELEVATIONS WILL LIKELY SEE GUSTS AS HIGH AS 40-45 MPH...WHILE BUKFIT DATA IMPLIES TOP WGUSTS IN THE 35-40MPH RANGE FOR THE REST OF US. THE AIR MASS WILL BE FAR FROM COLD FOR LATE DECEMBER STANDARDS...BUT COLD ENOUGH TO SUPPORT SCT OROGRAPHIC SNOW SHOWERS THRU AROUND MIDDAY OVR THE ALLEGHENY PLATEAU...WITH THE CENTRAL RIDGE-VALLEY REGION SEEING LITTLE MORE THAN A PASSING LIGHT RAIN OR SNOW SHOWER. FALLING INVERSION HGTS WITH APPROACH OF SFC RIDGE SHOULD CAUSE ANY MTN SNOW SHOWERS TO TAPER OFF DURING THE AFTN AND RESULT IN SOME BREAKS IN THE CLOUD COVER...ESP ACROSS THE LOWER SUSQ VALLEY. WITH SFC TEMPS EXPECTED TO BE ABV FREEZING EVERYWHERE...THE LIGHT SNOW SHOWERS ARE NOT EXPECTED TO ACCUMULATE...EXCEPT PERHAPS A DUSTING OVR THE HIGHEST RIDGETOPS. ENS MEAN 925/850 TEMPS SUPPORT HIGH TEMPS CHRISTMAS DAY FROM THE M30S OVR THE ALLEGHENY MTNS...TO THE U40S ACROSS THE LOWER SUSQ VALLEY. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... POTENT LONGWAVE UPPER TROF EXITING THE EAST COAST AT THE START OF THE PERIOD WILL BE REPLACED BY UPPER RIDGING INTO THE WEEKEND. AS LONGWAVE UPPER TROFFING IS FORECAST TO DEVELOP OVER THE WRN US STARTING EARLY IN THE PD AND NRN STREAM ENERGY RETREATS INTO EASTERN CANADA...MDT TO STRONG SWRLY FLOW ALOFT IS THEN FORECAST TO DOMINATE THE EASTERN CONUS FROM LATE IN THE WEEKEND THROUGH THE REMAINDER OF THE YEAR. MEDIUM RANGE GUIDANCE IS FAIRLY CONSISTENT ESPECIALLY EARLY IN THE PERIOD...BUT THEN SOME DIFFERENCES ARISE IN 500MB FLOW PATTERN AFTER MONDAY AS THE ECMWF MOVES ENERGY EAST FASTER...WHILE THE GFS CLOSES OFF AN UPPER LOW OVER THE DESERT SW. A NORTHERN STREAM WAVE IS FORECAST TO SUPPORT A COLD FRONT MOVING EAST ACROSS THE STATE LATE IN THE WEEKEND...POSSIBLY STALLING NEAR THE MASON DIXON LINE INTO MONDAY AS IT ENCOUNTERS RESISTANCE FROM THE BUILDING UPPER FLOW. THIS FRONT LOOKS TO BE THE MAIN FOCUS FOR PCPN IN THE LONG TERM PERIOD. WITH SNOW TO THE NORTH AND WEST...AND A MIX TO RAIN ACROSS THE SOUTH. WITH RIDGING OR SWRLY FLOW ALOFT MUCH OF THE PERIOD WILL FEATURE ABOVE NORMAL TEMPS...WITH A COOL DOWN TOWARD NORMAL BY NEW YEARS EVE. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... THE MAIN CONCERNS REMAINS LIFR TO MVFR CONDITIONS AND LLWS THIS EVENING FOR MUCH OF THE AREA. STILL WATCHING LINE OF STORMS ALONG THE PA...OH BORDER. SINCE WE ARE AT LEAST 10 DEGREES COOLER AND DEWPOINTS LOWER...THINK ANY REAL STRONG STORMS WILL WEAKEN AS THEY MOVE TOWARD CENTRAL PA. WILL CONTINUE TO MONITOR. SOME OF THE STRONGER STORMS WILL TRACK ACROSS NW WARREN COUNTY...JUST WEST OF BFD. HOWEVER...EXPECT SOME GUSTY WINDS WITH THE COLD FRONT AND JUST BEHIND THE FRONT. WINDS WILL SLOWLY DIE DOWN DURING THE DAY ON THU. LOW CIGS WILL PERSIST THE FIRST PART OF CRHISTMAS ACROSS THE AREA. EXPECT CONDITIONS TO BECOME VFR LATER IN THE DAY. NOT LOOKING BAD INTO FRIDAY AND SAT. OUTLOOK... FRI...MAINLY VFR. SAT...VFR. SUN-MON...MVFR TO IFR WITH SCATTERED RAIN AND SNOW SHOWERS. && .CTP WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL NOON EST THURSDAY FOR PAZ004>006-010>012- 017-018-024-033. && $$ SYNOPSIS...LA CORTE NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD/LA CORTE LONG TERM...LAMBERT/GARTNER AVIATION...MARTIN

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