Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 302228 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 628 PM EDT SUN AUG 30 2015 .SYNOPSIS... A WEAK TROUGH DYING OVER THE REGION AND HIGH MOISTURE WILL RESULT IN SCATTERED SHOWERS AND A FEW THUNDERSTORMS THIS EVENING. DRIER WEATHER WILL OCCUR FOR THE FIRST PART OF THE WEEK...BUT HIGH PRESSURE OFF THE EAST COAST WILL LEAD TO TEMPERATURES WELL ABOVE NORMALS ALL WEEK...WITH HIGH HUMIDITY. IT WILL FEEL MORE LIKE THE MIDDLE OF SUMMER THAN SEPTEMBER. && .NEAR TERM /UNTIL 11 PM THIS EVENING/... TWO AREAS OF FORCING...ONE SHEAR AXIS ALONG THE PA/NY BORDER AND ANOTHER OVER NORTHERN AND CENTRAL VIRGINIA...HAVE HELPED TO INITIATE AND MAINTAIN ISOLATED TO SCATTERED COVERAGE OF SHOWERS LATE THIS AFTERNOON INTO THE EARLY EVENING. A FEW LIGHTNING STRIKES OCCURRING WITH ACTIVITY OVER ADAMS COUNTY...WHICH IS THE MORE INTENSE AREA OF CONVECTION AT THIS TIME. STILL...CORES ARE NOT VERY HIGH...AND AT THE PRESENT TIME BRIEF DOWNPOURS AND WIND GUSTS OF 25 TO 30 MPH ARE ALL THAT WE EXPECT. UPPED POPS SLIGHTLY AND EXPANDED COVERAGE INTO AREAS THAT WEREN`T PREVIOUSLY INCLUDED. THINK THE IDEA OF SHOWERS LINGERING LONGEST IN THE SRN HALF OF THE AREA AND ESP SE IS GOOD...AS A WEAK SFC TROUGH SLIDES EAST BUT STALLS. CLOUD COVER IS A DIFFICULT FORECAST WITH RH PLOTS SHOWING A DECENT AMOUNT OF LOWER CLOUDS HANGING ON THROUGH THE NIGHT. THIS SEEMS REASONABLE SINCE THE WAVE DOES NOT GO THROUGH AND WE DO NOT GET INTO SUBSTANTIAL SUBSIDENCE. && .SHORT TERM /11 PM THIS EVENING THROUGH 6 PM MONDAY/... CLOUD COVERAGE WILL LIKELY REMAIN THE MOST DIFFICULT PART OF THE FORECAST OVERNIGHT. NAM RUNS A VERY SMALL PATCH OF LIGHT RAIN THROUGH THE NW BY MORNING...MOST LIKELY ASSOCD WITH UPSTREAM CONVECTION. AGAIN...NOT UNREASONABLE GIVEN THE HIGH MOISTURE AND BEGINNING OF THE RETURN FLOW IN WRN PA. JUST THE FAR SRN TIER HAS THE OTHER SLIGHT CHC FOR PRECIP OVERNIGHT AS THAT TROUGH LINGERS. HOWEVER...FORCING AND INSTABILITY WILL BE LACKING THERE. SOME FOG MAY DEVELOP...ESP IN PLACES WHICH HAD RAINFALL AND THOSE WHICH SEE MORE CLEARING THAN OTHERS. HOWEVER...DO NOT EXPECT WIDESPREAD FOG AT THIS POINT. MINS WILL RUN IN THE 60S EVERYWHERE AS DEWPOINTS SHOULD NOT GO ANY LOWER THAN 60F. SUBSIDENCE DOES NOT REALLY COME DOWN SOUTH ENOUGH TO ALLOW US TO DRY OUT ON MON. THE UPPER HIGH WILL CONTINUE TO SLIDE EASTWARD BUT SOME SEMBLANCE OF TROFFINESS REMAINS ACCORDING TO MOST GUID. WITH THE SFC HIGH RETURN FLOW INCREASING...A FEW SHRA/TSRA ARE STILL POSSIBLE MON...BUT MAINLY IN THE FAR SOUTH AND FAR NORTH. HAVE ALLOW FOR LINGERING SHRA S IN THE MORNING AND EARLY AFTN...AND MORE IN THE WAY OF DIURNAL SHRA IN THE NRN TIER. MAXES WILL BE A FEW DEGS HIGHER THAN TODAY - IF WE CAN GET RID OF MOST OF THE CLOUDS FOR A SHORT TIME - BECAUSE 8H TEMPS WILL BE ABOUT 2C WARMER. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... ANOMALOUS UPPER LEVEL RIDGE WILL DOMINATE THE OHIO VALLEY AND EASTERN UNITED STATES MUCH OF THE UPCOMING WEEK...WITH LATEST GUIDANCE REMAINING FIRM FOR AN EXTENDED RUN OF 850HPA TEMPS PEAKING DAILY AROUND 16-18C. THIS WILL TRANSLATE TO WELL ABOVE- NORMAL SFC TEMPS. THIS WARMTH AND INCREASING HUMIDITY SHOULD ALLOW FOR AT LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY...BUT WARM MID-LEVELS WILL KEEP THE PROBABILITY OF WIDESPREAD RAINFALL QUITE LOW. BEST CHANCES FOR PRECIP WILL BE MIDWEEK /WED-THU-FRI/ WITH A COUPLE SUBTLE FEATURES. FIRST...A WEAK UPPER LEVEL WAVE /BEST PROGGED ON THE ECMWF/ SLIPS OVERHEAD ON WED AS BERMUDA HIGH BRIEFLY RECEDES. AT SAME TIME A WEAK BACKDOOR COLD FRONT SLIPS SOUTHWARD OFF THE EAST COAST. THIS COULD HELP POOL SOME LOW LEVEL MOISTURE OVER THE MID ATLANTIC AND OHIO VALLEY AS MID LEVELS COOL JUST A BIT...BRINGING POTENTIAL FOR SCT TSTMS. RIDGE BUILDS BACK IN FOR FRI...BUT ANOTHER SURFACE BACKDOOR FRONT TRIES TO SLIP ACROSS THE STATE AS SURFACE HIGH EXPANDS IN FROM THE NORTH. THIS BOUNDARY SHOULD BRING SCT CONVECTION FOR FRI. EXTENDED MODELS HINT AT POTENTIAL FOR DAILY CONVECTION CONTINUING INTO THE WEEKEND ALONG SOUTHER BORDER...BUT OVERALL CONDITIONS WILL BE MAINLY RAIN-FREE. TEMPS PEAK MIDWEEK WITH READINGS APPROACHING 90F IN THE SE...AND EVEN GETTING INTO THE 80S ELSEHERE...EASILY WELL ABOVE NORMAL FOR THE FIRST WEEK OF SEPT. LOWS WILL ALSO REMAIN QUITE MILD MID/LATE WEEK AS HIGH HUMIDITY AIR HANGS AROUND. SLIGHTLY COOLER BUT STILL ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEKEND. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... A WEAK AREA OF LOW PRESSURE PASSING TO THE NORTH OF PA HAS SPAWNED SCT SHRA ACROSS CENTRAL PA EARLY THIS EVENING. CAN/T RULE OUT A BRIEF VIS REDUCTION BTWN 23Z-01Z IN THOSE FEW SPOTS THAT RECEIVE A HEAVIER SHOWER. HOWEVER...WIDESPREAD VFR CONDS WILL PREVAIL THIS EVENING. LOSS OF HEATING AND WEAKENING FORCING SHOULD CAUSE MOST OF THE SHOWERS TO DISSIPATE SHORTLY AFTER SUNSET. FOCUS LATER TONIGHT WILL SHIFT TOWARD POTENTIAL OF FOG. LIGHT WIND AND MCLEAR SKIES SHOULD PROMOTE LOCALLY DENSE VALLEY FOG AFTER MIDNIGHT ACROSS NORTHERN PA. ONLY GOING TO PUT IFR IN FOR A BRIEF TIME IN KBFD FOR THIS TAF CYCLE. TO THE SOUTH...INCREASING MID LVL CLOUDINESS WILL LIKELY RESULT IN LESS RADIATIONAL COOLING AND A DIMINISHED THREAT OF FOG. WIDESPREAD VFR CONDS AND LIGHT WIND APPEARS LKLY MONDAY WITH ONLY ISOLD LATE DAY SHRA/TSRA POSSIBLE...AS HIGH PRESSURE BUILDS OFF THE MID ATLANTIC COAST. OUTLOOK... TUE-THU...NO SIG WX EXPECTED AREAS MVFR OVERNIGHT PATCHY FOG. FRI...LCL TSRA POSS - MAINLY S. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO/LAMBERT NEAR TERM...DANGELO/DEVOIR SHORT TERM...DANGELO LONG TERM...RXR AVIATION...DANGELO/FITZGERALD

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