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 280117 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 917 PM EDT WED AUG 27 2014 .SYNOPSIS... A COLD FRONT WILL CLEAR THE SOUTHERN TIER OF THE STATE OVERNIGHT. HIGH PRESSURE WILL ARRIVE BEHIND THE FRONT AND BRING DRY WEATHER TO THE AREA THROUGH THE END OF THE WEEK. ABOVE NORMAL TEMPERATURES AND INCREASINGLY HUMID AND UNSETTLED CONDITIONS ARE FORECAST OVER THE LABOR DAY HOLIDAY WEEKEND AND INTO THE FIRST WEEK OF SEPTEMBER. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... CAP WAS FAIRLY STUBBORN THIS EVENING...BUT ISOLATED TO SCATTERED COVERAGE OF SHOWERS AND THUNDERSTORMS DID EVOLVE ALONG AND AHEAD OF THE FRONT OVER THE SOUTHEAST HALF OF THE COMMONWEALTH DURING MAX HEATING. ZONE OF GREATEST INSTABILITY EXTENDED FROM THE LAUREL HIGHLANDS TO THE MIDDLE SUSQUEHANNA RIVER VALLEY WHERE MESO ANALYSIS DEPICTED CAPES LOCALLY EXCEEDING 1200 J/KG. SEVERAL STORMS GARNERED SUFFICIENT CONCERN FOR SPSS AND EVEN A FEW FOR WARNINGS GIVEN THEIR VERTICAL DEVELOPMENT...BUT WITH LITTLE AMBIENT WIND TO WORK WITH AND INSUFFICIENT COLD POOL GENERATION...NO SEVERE REPORTS HAVE BEEN FIELDED THUS FAR. FOR THE OVERNIGHT...ISOLATED SHOWER AND THUNDERSTORM ACTIVITY CONTINUES TO WEAKEN ALONG AND AHEAD OF THE SLOWLY SEWD ADVANCING SFC FRONT...WHICH EXTENDS AT THIS HOUR FROM JUST SE OF KJST NORTHEASTWARD TO NEAR KIPT. DRIER AIR WILL CONTINUE TO FILTER SEWD FROM THE CENTRAL MOUNTAINS SOUTH AND EAST THROUGH THE PRE DAWN HOURS. SKIES HAVE CLEARED ACROSS THE NORTH...BUT A PATCH OF CIRRUS EXTENDS FROM SOUTHERN LOWER MICHIGAN THROUGH NORTHERN OHIO WHICH WILL FILTER ACROSS CENTRAL AREAS OVERNIGHT. ISOLATED SHOWERS WILL END ACROSS THE SOUTH AS THE FRONT CLEARS MY SOUTHERN COUNTIES. DECOUPLING IS EXPECTED IN MOST AREAS...LEADING TO THE USUAL RIVER VALLEY FOG EARLY THURSDAY MORNING. MINS SHOULD RANGE FROM THE REFRESHING UPPER 40S NORTH TO THE L60S IN THE SRN TIER. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... COOL POST-FRONTAL NW FLOW WILL MAKE FOR A MOSTLY SUNNY DAY OVER MOST OF THE REGION. THE ONLY FLY IN THE OINTMENT MIGHT BE THE APPROACH OF A LOWER CLOUD DECK FROM THE N/NE AS A STRONG PORT MAX DROPS S ACROSS NY STATE. WILL KEEP POPS UP NEAR ISOLD NUMBERS IN THE NE...BUT NOT MENTION PRECIP QUITE YET. A SPRINKLE IS POSSIBLE IN THE NE THOUGH. MAXES WILL BE ABOUT 8-10F BELOW WEDNESDAY/S LOFTY NUMBERS. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... THE MEDIUM RANGE FLOW PATTERN WILL FEATURE TROUGHING IN THE WEST AND FAIRLY HIGH HEIGHTS FCST TO PREVAIL OVER THE EAST SUPPORTED BY A SUBTROPICAL RIDGE THAT SHOULD ANCHOR OVER THE SOUTHEAST. THIS RIDGE WILL ALLOW HIGH PRESSURE TO CENTER OVER UPSTATE NY AT THE START OF THE PERIOD. THIS WILL SLOWLY MOVE OFF THE NEW ENGLAND COAST ON SATURDAY. A LONG FRONTAL BOUNDARY EXTENDING FROM AN UPPER LEVEL LOW CENTERED OVER NORTHERN CANADA...AND TO A NEGATIVELY TILTING TROUGH WHICH SHOULD BE MOVING INTO THE MIDWEST. THE BIGGEST MOISTURE FROM THE FRONTAL BOUNDARY IS PROGGED TO STAY NORTH OF PA. HOWEVER...THERE SHOULD BE ENOUGH MOISTURE...WITH ENOUGH FORCING TO WARRANT INCREASING PROBABILITY/OPPORTUNITY FOR RAIN SATURDAY NIGHT INTO EARLY MONDAY. DAYTIME CONVECTION WILL ALSO BE SPURRED ON BY A WARMING TREND WITH MAX TEMPS 5-10F ABOVE NORMAL OVER THE WEEKEND AND INTO THE FIRST WEEK OF SEPT. THE BEST CHANCE FOR PRECIPITATION THROUGH THIS TIMEFRAME SHOULD BE SUNDAY AFTERNOON INTO SUNDAY EVENING. THERE IS SOME MODEL VARIATION SO EXPECT SOME MODIFICATIONS AS TIME PROGRESSES. A GFS AND EC IN THE LONG RANGE ARE ACTUALLY IN FAIR AGREEMENT THROUGH THE FIRST HALF OF NEXT WEEK...INCLUDING THE SUBSTANTIAL TROUGH THAT SHOULD MOVE THROUGH WEDNESDAY AS MORE DEFINED COLD FRONT SHOULD APPROACHES THE AREA. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... COLD FRONT APPEARS TO BE JUST THROUGH KBFD AT 18Z. ONE BATCH OF TSRA OVER KAGC IS HEADED SOUTH OF KJST. ALL BUT KBFD WILL CONTINUE TO HAVE THE POSSIBILITY FOR TSRA IN THE VCTY...BUT HAVE ONLY INCLUDED VCSH/TS FOR NOW DUE TO SPARSE COVERAGE. THIS THREAT SHOULD END AROUND 23Z-00Z IN IPT/UNV BUT COULD LINGER UNTIL 03Z IN THE SRN TERMINALS. WIND SHIFT TO THE NW BEHIND THE FRONT WILL BRING DRIER AND COOLER AIR. NORMAL VALLEY FOG IS EXPECTED IN THE NRN VALLEYS AS THE TEMPS DROP OFF WELL BELOW THE RIVER WATER TEMPS. BUT THERE COULD BE A LITTLE WIND WHICH COULD IMPEDE FOG FORMATION. WILL PUT MVFR FOG IN MOST TAFS AND IFR FOG IN BFD FOR A FEW HRS LATE TONIGHT. THE NW WINDS PICK UP AFTER SUNRISE BUT SKIES AND VIS SHOULD BE VFR. A LOW-END VFR CLOUD DECK MAY DROP DOWN FROM WRN NY STATE DURING THE DAYLIGHT HRS ON THURS. OUTLOOK... FRI-SAT...EARLY MORNING FOG RESTRICTIONS POSSIBLE...OTHERWISE VFR. SUN-MON...MAINLY VFR. SCT AFTERNOON SHOWERS/TSTMS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO/DEVOIR SHORT TERM...DANGELO LONG TERM...CERU/STEINBUGL AVIATION...DANGELO

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