Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 181201 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 801 AM EDT SAT OCT 18 2014 .SYNOPSIS... A STRONG COLD FRONT WILL CROSS THE COMMONWEALTH TODAY...BRINGING WINDY AND SHARPLY COLDER CONDITIONS FOR TONIGHT AND SUNDAY. HIGH PRESSURE WILL MOVE IN FOR SUNDAY AND MONDAY BEFORE ANOTHER DISTURBANCE BRINGS THE NEXT CHANCE OF SHOWERS TUESDAY THROUGH MIDWEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... CENTER OF VIGOROUS H5 TROF LOCATED OVER SOUTH CENTRAL ONTARIO THIS MORNING. WEAKENED SFC OCCLUSION/PRE FRONTAL TROF PUSHING INTO EASTERN PA AHEAD OF COLD FRONT DROPPING SOUTHEASTWARD ACROSS THE EASTERN GLAKS. THIS VIGOROUS COLD FRONT WILL DELIVER A SURGE OF COLDER AIR AND WIND BEGINNING ACROSS NORTHWEST MOUNTAINS BY 10Z... THE ALLEGHENY CREST BY 11-12Z...THE CENTRAL MOUNTAINS BY 13Z AND EASTERN PORTIONS OF CENTRAL PA BY 15Z. STRONG DOWNSLOPE FLOW WILL LIMIT SHOWER ACTIVITY FROM THE CENTRAL MOUNTAINS EAST AND SOUTH... WITH HIGHEST POPS FROM THE WEST CENTRAL MOUNTAINS NORTHWARD TO THE PA/NY BORDER THIS MORNING. POST FRONTAL UPSLOPE SHOWERS ACROSS THE WEST CENTRAL AND NORTHWEST MOUNTAINS WILL PERSIST THROUGH THE AFTERNOON. DOWNSLOPE FLOW WILL ALLOW MAXES ACROSS THE LOWERS SUSQ TO REACH THE LOWER 60S...WHILE MAXES ACROSS THE WEST AND NORTH WILL BE REACHED EARLY TODAY WITH TEMPS STEADY OR SLOWLY FALLING LATER THIS MORNING AND AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... MUCH COLDER AIR WILL CONTINUE TO STREAM OVERHEAD TONIGHT... MIXING RAIN SHOWERS WITH SNOW SHOWERS AND MAINTAINING A GUSTY NNW WIND. 850 MB TEMPS DIPPING TO -2C TO -4C THIS EVENING WILL COOL FURTHER BY 12Z SUN WITH -6C 850 MB TEMPS SLIDING ACROSS NORTH CENTRAL PA EARLY SUNDAY MORNING. EXPECT FAIRLY WIDESPREAD STRATO-CU CEILINGS WITH THE USUAL COLD ADVECTION/UPSLOPE SHOWERS FAVORING WESTERN AREAS...WITH SOME POSSIBLY BLEEDING INTO CENTRAL AREAS. PRECIP AMOUNTS WILL BE LIGHT. HIGHS WILL BE 5-10 DEG COOLER THAN SAT...RANGING FROM NEAR THE LOWER TO MIDDLE 40S OVER THE NW MOUNTAINS TO MID 60S OVER THE SE. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... THE 17/12Z MODELS SHOW LITTLE SPREAD WITH A SHORTWAVE TROUGH DIGGING RATHER SHARPLY EWD THROUGH THE OH VLY ACROSS THE CENTRAL APPALACHIANS INTO THE MID ATLC STATES BTWN 00-12Z SUNDAY. THIS ENERGY IS FCST BY ALL THE GUIDANCE TO GO NEGATIVE TILT AS IT REACHES NEW ENGLAND BY SUNDAY AFTERNOON. A RELATIVELY COLD AND GUSTY NW FLOW ON THE BACKSIDE OF THE UPPER LEVEL TROUGH WILL SUPPORT LAKE EFFECT/TERRAIN ENHANCED RAIN AND SNOW SHOWERS SAT NIGHT INTO EARLY SUNDAY OVER THE ALLEGHENY HIGHLANDS AND NORTHWEST PLATEAU DOWNWIND OF LAKE ERIE. CANT RULE OUT SOME MINOR ACCUMS ON THE HIGHEST RIDGETOP ELEVATIONS. A BRISK NW WIND ALONG WITH ENSEMBLE MEAN 850MB TEMPS -1 TO -2 STD BELOW NORMAL WILL RESULT IN A VERY CHILLY DAY ON SUNDAY WITH HIGHS AVERAGING 10F BELOW MID- LATE OCTOBER CLIMATE NORMALS. APPARENT TEMPS /WIND CHILLS/ ARE FCST TO DIP INTO THE 20S AND LOW 30S OVER THE ALLEGHENIES SATURDAY NIGHT INTO EARLY SUNDAY. SFC HIGH PRESSURE ARRIVING LATER SUNDAY FROM THE MIDWEST SHOULD PROMOTE DECREASING CLOUDS AND A PERIOD OF DRY WEATHER INTO MONDAY AFTERNOON. DOWNSTREAM OF A STRENGTHENING LARGE SCALE RIDGE OVER THE INTERMTN WEST AND SW CANADA...ANOTHER SHORTWAVE TROUGH AND WEAK CLIPPER TYPE AREA OF SFC LOW PRESSURE ARE FCST TO DIG DOWN INTO THE UPPER MS VLY BY LATE SUNDAY. THE LATEST MODEL AND ENSEMBLE CONSENSUS NOW STRONGLY FAVORS CONTINUED AMPLIFICATION OF THE SHORTWAVE TROUGH AS IT CROSSES THE GREAT LAKES/OH VLY REGION EARLY NEXT WEEK BEFORE CLOSING OFF INTO AN UPPER LOW OVER THE MID ATLC BY 12Z ON 22 OCT. THIS SYSTEM IS PROGGED TO CLOSE OFF FARTHER EAST THAN THE RECENT DEEP UPPER LOW WHICH SHOULD RESULT IN THE POTENTIAL FOR A SIGNIFICANT COASTAL LOW TO DEVELOP ONCE THE WEAK CLIPPER LOW OVER THE GREAT LAKES TRANSFERS ENERGY OFF THE COAST. THE PATTERN EVOLUTION WED-FRI WILL BRING CHILLY AND BREEZY WEATHER TO THE AREA WITH TEMPS BELOW NORMAL. CONTINUED TO INCREASE POPS BASED ON WPC SUPERBLEND WITH THE PROSPECT OF CHILLY RAIN/SHOWERS LOOKING EVER MORE LKLY. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
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LATEST RADAR SHOWS A BAND OF SHOWERS MOVING ACROSS THE NORTH CENTRAL PA. SCATTERED SHOWERS CONTINUE TO STREAM ACROSS THE REST OF CENTRAL PA AHEAD OF AN OCCLUDED/COLD FRONT THAT WILL MOVE ACROSS THE REGION THIS AFTERNOON. THIS FRONT WILL BRING DETERIORATING CONDITIONS THROUGH MOST OF THE DAY...MAINLY ACROSS THE WESTERN TAF SITES. EXPECT MVFR CIGS AT BFD AND JST THROUGH MOST OF THE MORNING. THROUGH THE LOWER CIGS SHOULD CONTINUE AT BFD THROUGH MOST OF THE DAY. SHOWERS SHOULD SPREAD ACROSS THE CENTRAL TAF SITES THIS EVENING INTO SUNDAY MORNING...WITH MVFR POSSIBLE TONIGHT AT AOO...UNV AND IPT. AFTER THE FRONT MOVES THROUGH...CONDITIONS WILL IMPROVE SLOWLY AT MOST TERMINALS...BUT WITH MVFR/IFR LINGERING AT BFD TONIGHT INTO TOMORROW. THE WINDS BEHIND THE FRONT WILL BECOME NW AND SHOULD HAVE GUSTS UPWARDS OF 15-25KT....BUT SHOULD CALM TO ABOUT 5 TO 10 KTS TONIGHT BETWEEN 03Z TO 06Z. OUTLOOK... SUN...MVFR EARLY BECOMING VFR. DECREASING WINDS. MON...NO SIG WX. TUE-WED...MVFR/SHOWERS AS A SLOW MOVING SYSTEM MOVES IN FROM THE GR LAKES.
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&& .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DEVOIR NEAR TERM...DEVOIR SHORT TERM...DEVOIR LONG TERM...STEINBUGL AVIATION...CERU

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