Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 310352 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 1152 PM EDT WED JUL 30 2014 .SYNOPSIS... AN UPPER LEVEL LOW PRESSURE WILL STAY ANCHORED OVER JAMES BAY CANADA THROUGH FRIDAY BEFORE WEAKENING AND MOVING TO THE NORTHEAST. ANOTHER TROUGH FORMING OVER THE LOWER OHIO VALLEY WILL BRING INCREASINGLY HUMID AND UNSETTLED CONDITIONS FOR THE WEEKEND. TEMPERATURES WILL REMAIN COOLER THAN NORMAL. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 10 PM UPDATE... THE LINE OF SHOWERS AND THUNDERSTORMS HAS WEAKENED CONSIDERABLY AS IT MOVES THROUGH THE MIDDLE AND LOWER SUSQ VALLEY. HOWEVER SCATTERED CONVECTION CONTINUES BACK THROUGH THE LAURELS AS WELL AS NWRN MOUNTAINS. HRRR SHOWS ACTIVITY DWINDLING AFTER MIDNIGHT...BUT NOT DISAPPEARING ALTOGETHER UNTIL AROUND DAWN. SATELLITE SHOWS THE LARGE AREA OF CYCLONIC FLOW OVER THE NERN US...WITH ANY NUMBER OF SMALLER DISTURBANCES EMBEDDED WITHIN THAT FLOW SO THE IDEA THAT SHOWERS WILL BE SLOW TO GO AWAY LOOKS REASONABLE. MIN TEMPS WILL BE CLOSER TO NORMAL TONIGHT...BUT SOME READINGS IN THE 40S ARE STILL POSSIBLE ACROSS THE NR MTNS REGION AND PERHAPS A FEW OF THE COLD SPOTS ACROSS THE HIGH TERRAIN OF SOMERSET COUNTY. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... THE UPPER LOW THROWS ONE MORE UPPERCUT AT NRN PENN THURSDAY MORNING...BEFORE REFUELING TEMPORARILY FOR A DAY OR SO ACROSS THE LOWER OHIO VALLEY. SCT/NMRS SHOWERS ARE EXPECTED TO AFFECT THE NRN THIRD TO HALF OF THE CWA IN THE MORNING. THE AFTERNOON SHOULD TURN OUT TO BE MAINLY DRY - WITHIN AN AREA OF LARGE SCALE SUBSIDENCE AND WEAK SFC HI PRESSURE IN THE WAKE OF THE UPPER WAVE. TEMPS ALOFT WILL STILL BE COOL AND DAYTIME INSTABILITY SHOULD BE GOOD ENOUGH FOR ISOLD-SCT SHOWERS IN THE WEST/NORTH DURING THE MID TO LATE AFTERNOON. HIGHS TEMPS THURSDAY MAY TRY TO SNEAK BACK TO NORMAL IN THE SE...BUT THE N/W ZONES WILL PROBABLY STILL BE 8-10 DEGS BELOW SEASONAL NORMALS GIVEN MORE IN THE WAY OF CLOUDS AND SCATTERED SHOWERS. THE THURSDAY NIGHT PERIOD CONTINUES TO LOOK LIKE THE LEAST LIKELY TIME FOR ANY SHOWERS TO DEVELOP WITH 500 MB HEIGHT RISE OF A FEW DAM...AND WEAK RIDGING OVER THE AREA AT THE SFC. LOWS EARLY FRIDAY MORNING WILL BE SIMILAR TO THE PREV FEW NIGHTS WITH SKIES TRYING TO CLEAR AND WINDS GENERALLY LIGHT/VARIABLE. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... 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 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 /04Z THURSDAY THROUGH MONDAY/... PRECIPITATION DIMINISHING OVER THE SOUTHERN HALF OF THE STATE THIS EVENING WITH ONLY A DROP TO MVFR WHERE IT DOES RAIN. ELSEWHERE...OCCASIONAL DROP TO IFR IN FOG IS OCCURRING WHERE RAIN FELL EARLIER IN THE DAY. CEILINGS WILL VARY OVERNIGHT AND NOT RECOVER UNTIL SUNRISE. A STRONGER 500 MB TROUGH WILL ROTATE ACROSS THE UPPER GREAT LAKES ON THU...ACCOMPANIED BY ANOTHER ROUND OF SCTD SHOWERS AND STORMS MAINLY OVER NEW YORK...POSSIBLY SNEAKING INTO THE KBFD AREA LATER IN THE DAY. OUTLOOK... THU...SCT TSRA IMPACTS POSSIBLE. FRI-SUN...SCT PM TSRA IMPACTS POSSIBLE. MON-TUE...SLOW IMPROVEMENT EXPECTED WITH AREAS OF MVFR POSSIBLE MAINLY IN THE MORNING. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...DANGELO/LAMBERT LONG TERM...STEINBUGL AVIATION...LAMBERT/TYBURSKI

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