Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 311916 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 316 PM EDT THU JUL 31 2014 .SYNOPSIS... A CLOSED UPPER LEVEL LOW PRESSURE CENTERED OVER JAMES BAY WILL LIFT SLOWLY NORTHEAST LATE TODAY. THE TRAILING LONG WAVE TROUGH WILL SHARPEN UP OFF TO OUR WEST THROUGH THE WEEKEND...HELPING TO DRAW INCREASING MOISTURE INTO THE REGION FROM THE SOUTH. THIS WILL LEAD TO PERIODS OF UNSETTLED CONDITIONS FOR LATER FRIDAY...RIGHT THROUGH THE UPCOMING WEEKEND. TEMPERATURES WILL REMAIN COOLER THAN NORMAL. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... CHAOTIC SKY COVER NOTED ON THE REGIONAL VIS SATELLITE IMAGERY WITH A FEW ISOLATED SHOWERS DEVELOPING OVER THE LAURELS AND CENTRAL RIDGE AND VALLEY REGION AT 1830Z. THIS /SO FAR/ WEAK AND LOW- TOPPED CONVECTION WAS FORMING RIGHT WITHIN A WAVY...NEARLY EAST- WEST RIBBON OF ENHANCED 0-3KM...AND SFC-900MB ML CAPE OF UP TO 500 J/KG. 17Z HRRR LOOKS TO HAVE A DECENT HANDLE ON THE CURRENT LOCATION /AND TREND OF THIS LATE AFTERNOON CONVECTION/...FOCUSING IT OVER THE NEXT SEVERAL HOURS ACROSS THE LOWER SUSQ AND SOUTHERN POCONOS WHERE SOME LOW-TOPPED TSRA WILL ALSO BE POSSIBLE. POPS WILL STILL ONLY BE AROUND 30-40 PERCENT GIVEN THE EXPECTED SCATTERED CVRG. ELSEWHERE...WILL BROAD-BRUSH THE REGION WITH SCHC POPS FOR A STRAY SHOWER OR TSRA. WINDS WILL GO L/V TONIGHT UNDER A RIDGE OF HIGH PRESSURE WITH GENERALLY PARTLY CLOUDY /ALTO CU OR HIGH BASED STRATO CU/. LOW TEMPS WILL BE NEAR 50F ACROSS THE NORTH AND NEAR 60 IN THE SOUTHEAST. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... NEAR NORMAL PWATS OF AROUND /OR SLIGHTLY UNDER ONE INCH/ WILL GRADUALLY INCREASE TO OVER 1.5 INCHES ACROSS THE SE THIRD-HALF OF THE CWA BY 00Z SAT AS DEEPENING SOUTHERLY FLOW DEVELOPS. CLOUDS WILL LIKELY BE ON THE INCREASE THROUGHOUT THE DAY /INITIALLY BEING FUNNELED UP THROUGH THE CENTRAL MTNS AND LOWER SUSQ VALLEY DURING THE MORNING AND MIDDAY HOURS/...WHICH SHOULD LIMIT SFC BASED CAPES TO GENERALLY 1000 J/KG OR LESS. AS THE RIGHT ENTRANCE REGION OF A 75KT SWRLY JET LIFTS NORTH ACROSS THE SCENT ZONES AND SUSQ VALLEY...THE CHANCE FOR SHOWERS AND PERHAPS A FEW TSRA WILL INCREASE TO 40-60 PERCENT BY THE MID AFTERNOON HOURS. TEMPS DO GET NEARER TO NORMAL ON FRIDAY WITH HIGHS IN MID TO UPPER 70S NORTH TO LOWER 80S IN THE SE. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... THE GLOBAL MODELS AND ENSEMBLE MEMBERS SHOW THE HIGHLY AMPLIFIED NOAM WESTERN RIDGE/EASTERN TROUGH CONFIGURATION RELAXING INTO EARLY NEXT WEEK...BUT OTHERWISE MAINTAINING ITS ORIENTATION. THE RISING 500MB HGTS SHOULD ALLOW TEMPERATURES TO EDGE BACK TOWARD EARLY AUGUST CLIMATE NORMALS. THE GENERAL PATTERN REMAINS UNSETTLED THROUGH THE WEEKEND. THE MEAN UPPER TROUGH AXIS SHIFTS WWD TO NEAR 90W WHICH SHOULD ALLOW THE QSTNRY FRONTAL ZONE DRAPED ALONG THE EASTERN SEABOARD TO DRIFT WWD ALONG THE I-95 CORRIDOR. THE 12Z/30TH GEFS SHOWS PLUME OF HI PWATS POOLING NEAR THE SFC BOUNDARY ALONG/E OF THE APPLCHN SPINE. THIS SUGGESTS THE POTENTIAL FOR HVY RAFL SETTING UP FROM THE SRN MID ATLC STATES UP INTO SERN PA/DELMARVA/NJ AREAS. THERE ARE STILL SOME QPF DIFFERENCES BUT THE LATEST RUNS SEEM TO BE CONVERGING TOWARD THE IDEA THE THE MAIN QPF AXIS WILL BE EAST OF THE APPLCHNS...ALTHOUGH THE DIURNAL CYCLE AND INDIVIDUAL SHORTWAVES MOVING THROUGH THE LW TROUGH WILL PLAY A ROLE IN THE DURATION AND PLACEMENT. CONDITIONS SHOULD IMPROVE INTO EARLY NEXT WEEK AS THE HI PWAT PLUME SHIFTS S/E AND DRIER AIR ARRIVES ACCOMPANIED BY SFC HIGH PRES ON MON. NRN STREAM ENERGY IS SLATED TO PUSH A COLD FRONT SWD INTO THE AREA BY NEXT TUE/WED WHICH MAY STALL OUT FROM THE OH VLY INTO THE MID ATLC STATES. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... A CLOSED UPPER LEVEL LOW PRESSURE CENTERED OVER JAMES BAY WILL LIFT SLOWLY NORTHEAST LATE TODAY. WIDESPREAD VFR...WITH BRIEF MVFR CIGS AND VSBYS IN COMPACT SHOWERS AND TSRA WILL OCCUR THROUGH 23Z. WILL CONTINUE TO MENTION VCSH AT KIPT...KMDT AND KLNS FOR A 3-4 HOUR PERIOD DURING THE MID TO LATE AFTERNOON HOURS TODAY AS HIGH RES MODELS SHOW ISOLATED TO SCATTERED SHOWERS BECOMING FOCUSED ACROSS THAT REGION. ISOLATED-SCATTERED CONVECTION CAN/T BE RULED OUT ELSEWHERE ACRS THE CENTRAL AND WESTERN PA AIRFIELDS LATE THIS AFTERNOON. HOWEVER...THE OVERALL PROBABILITY IS TOO LOW TO MENTION IN MOST OF THE INDIVIDUAL TERMINALS. LIGHT WINDS PICK UP TO AROUND 10 MPH FROM THE SW TODAY...BEFORE BECOMING LIGHT AGAIN TONIGHT. JUST AN OUTSIDE CHANCE FOR A SHOWER IN THE NORTH TONIGHT. OTHERWISE GENERALLY QUIET WEATHER WITH SOME PATCHY 2-4SM FOG DEVELOPING AGAIN AFTER MIDNIGHT. OUTLOOK... FRI-SUN...SCT PM TSRA IMPACTS POSSIBLE. MON...SLOW IMPROVEMENT EXPECTED WITH AREAS OF MVFR POSSIBLE MAINLY IN THE MORNING. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...STEINBUGL AVIATION...LAMBERT

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