Area Forecast Discussion
Issued by NWS State College, PA

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 020627 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 227 AM EDT TUE SEP 2 2014 .SYNOPSIS... WARM AND HUMID CONDITIONS WILL CONTINUE INTO TUESDAY EVENING WHEN A COLD FRONTAL PASSAGE BRINGS DRIER AND SLIGHTLY COOLER AIR TO CENTRAL PENNSYLVANIA. HUMIDITY WILL RETURN TOWARD THE END OF THE WEEK AHEAD OF THE NEXT FRONTAL SYSTEM THAT WILL BRING THE CHANCE OF RAIN FOR THE UPCOMING WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... RADAR LOOP AT 05Z SHOWING A BKN LINE OF SHRA/TSRA ENTERING NW PA AHEAD OF SHORTWAVE CROSSING THE E GRT LKS. MODEST FORCING AHEAD OF THIS FEATURE...COMBINED WITH A VERY MOIST AND MARGINALLY UNSTABLE ENVIRONMENT OVR PA...SHOULD SUPPORT SCT SHRA DURING THE EARLY HOURS. WILL PLACE HIGHEST /LIKELY/ POPS IN THE NEAR TERM OVR THE NW MTNS...CLOSEST TO SHORTWAVE. WANING UPPER LVL SUPPORT AND COOLING BLYR SHOULD TRANSLATE TO ONLY A SLIGHT CHC OF SHRA ACROSS THE EASTERN COS LATER THIS MORNING. RADAR TRENDS AND LATEST RAP OUTPUT INDICATE THE THREAT OF SCT SHRA WILL SHIFT EASTWARD INTO THE CENTRAL MTNS TOWARD DAWN...THEN THE EASTERN COUNTIES BTWN 12Z- 15Z. LIGHT WIND...PTCLDY SKIES AND WET GROUND SHOULD YIELD AREAS OF FOG DURING THE EARLY AM HOURS. LOW CLOUDS ARE ALSO POSSIBLE ACROSS THE UPSLOPE REGIONS ALONG THE ALLEGHENY HIGHLANDS. TEMPS ON TRACK TO BOTTOM OUT IN THE U60S TO L70S IN THIS MUGGY AIR MASS. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/... A WELL-DEFINED COLD FRONT /WITH SHARP MSTR- PW GRADIENT/ WILL DROP ACROSS THE REGION TUESDAY AFTERNOON AND EVENING. A CONDITIONAL RISK FOR STRONG TO ISOLATED SEVERE STORMS WILL EXIST FROM LATE TUE MORNING THROUGH THE AFTERNOON WITH THE PRIMARY POTNL TSTM HAZARD BEING DAMAGING WINDS. CLOUD COVER FROM UPSTREAM CONVECTION LKLY ONGOING AT 12Z ALONG WITH RESIDUAL OVERNIGHT LOW STRATUS/FOG SHOULD ACT TO LIMIT DESTABILIZATION EARLY TOMORROW. ALTHOUGH 700-500MB LAPSE RATES WILL GENERALLY REMAIN WEAK TO POOR...THE MODELS SHOW A BELT OF STRONGER WESTERLY MID-LVL FLOW AND DEEP LYR SHEAR. THIS SHOULD HELP TO SUPPORT AN INCREASE IN CONVECTIVE PCPN/INTENSITY AS RENEWED DEVELOPMENT OCCURS ALONG OUTFLOWS/DIFFERENTIAL HEATING ZONES BY LATE MORNING INTO THE AFTERNOON...WITH SOME ORGANIZATION INTO LINE SEGMENTS/CLUSTERS. THIS SHOULD YIELD AT LEAST AN ISOLD DMGG WIND THREAT...WARRANTING AN UPGRADE BY SPC TO A CATEGORICAL /SLGT/ RISK DESIGNATION. THIS HAS BEEN REFLECTED IN AN UPDATED HWO. EARLY CLOUDS SHOULD BREAK FOR A WARM AND HUMID DAY WITH FCST HIGHS EXPECTED TO RANGE FROM THE MID 70S OVER THE NW TO NEAR 90 OVER THE LOWER SUSQ VLY. THE SECOND HALF OF THE PERIOD ESPECIALLY AFTER MIDNIGHT SHOULD FEATURE A COOLER/DRYING TREND BEHIND THE FRONT WITH PWS FALLING AOB NORMAL BY 12Z WED. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... COLD FRONT EXITING TO THE EAST TUE NIGHT ALONG WITH NORTHWEST FLOW AROUND BUILDING HIGH PRESSURE AREA OVER OHIO VALLEY WILL BRING A TRANSITION TO A NOTICABLY DRIER AIRMASS FOR MIDWEEK. DAYTIME HIGHS WILL REMAIN SLIGHTLY ABOVE NORMAL...BUT LOWER DEWPOINTS WILL MAKE IT FEEL MORE COMFORTABLE. OVERNIGHT LOWS WED NIGHT WILL DIP TO NEAR 50F IN THE NORTHERN MTNS TO AROUND 60F IN THE SE. THE HIGH WILL MOVE OFF THE EAST COAST THU INTO FRI...ALLOWING MORE HUMID AIR TO BEGIN RETURNING TO THE REGION. A SURFACE LOW SLIDES FROM THE NORTHERN PLAINS ACROSS THE GREAT LAKES AND LIFTING INTO S CANADA ON FRI...DRAGGING A COLD FRONT ALONG BEHIND. AS THIS FRONT APPROACHES...AN AREA OF HIGHER PWATS /1-2"/ SURGES INTO THE OHIO VALLEY...AND THEN INTO PA FRI NIGHT INTO SAT. AT SAME TIME A BROAD UPPER TROUGH SAGS SOUTHWARD. THIS WILL BRING ELEVATED CHANCES FOR SHOWERS/TSTMS STARTING FRI NIGHT IN THE NW AND SPREADING AREAWIDE ON SAT. BEHIND THE FRONT...AIRMASS CHANGE WILL USHER IN MUCH COOLER AND DRIER AIR FOR LATE WEEKEND INTO EARLY NEXT WEEK. HIGHS WILL FALL BACK ABOUT 10F...RANGING FROM THE UPPER 60S TO MID 70S. AS LARGE HIGH PRESSURE AREA TRACKS ACROSS NEW ENGLAND...MORNING LOWS SHOULD DIP WELL INTO THE 40S ACROSS THE NORTHERN MTNS...AND IN THE LOWER TO MID 50S ACROSS THE SOUTH. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ACROSS NORTH CENTRAL PA EARLY THIS MORNING. NGM SHOWS THIS AREA MOVING EAST OF THE AREA IN A FEW HOURS. ISOLATED SHOWERS ACORSS THE SOUTH. WAS STRONGER STORMS JUST SOUTH OF THE PA BORDER WHEN I CAME IN AT MIDNIGHT. MORE SHOWERS AND STORMS POSSIBLE LATER THIS AFT AND EARLY EVENING...AS WEAK COLD FRONT DROPS SE. 06Z TAFS SENT. EARLIER DISCUSSION BELOW. VFR CONDITIONS EVERYWHERE AS THE LOSS OF HEATING RAISED THE STABILITY AND PASSAGE OF A VERY WEAK WAVE HAS LEFT US IN A LULL. ANOTHER WEAK WAVE IS APPROACHING FROM OHIO AND IS TOUCHING OFF SOME SHOWERS TO THE WEST. NAM BLOSSOMS THIS AREA AS THE SWRLY FLOW INCREASES SLIGHTLY OVERHEAD. BUT WILL LEAV IT MOSTLY DRY THROUGH THE NIGHT EXCEPT IN THE NW. THE 70PLUS DEWPOINTS AND UPSLOPE INTO THE WRN MTS WILL CREATE LOW CLOUDS AND FOG AGAIN TONIGHT. SOME DRIZZLE IS ALSO POSSIBLE THERE. THE SERN HALF OF THE AREA WILL BE MAINLY VFR. A COLD FRONT MOVING SEWRD OVER THE LOWER LAKES LATER IN THE DAY WILL MEAN THE AREA WILL STAY IN THE WARM-SECTOR AND THUNDERSTORMS WILL BECOME SCATTERED OVER THE AREA IN THE AFTERNOON. THIS FRONT WILL BE A BETTER FOCUS FOR NMRS SHWRS/TSTMS IN THE EVENING AS IT MOVES SEWRD ACROSS CENTRAL PA. SOME OF THE STORMS COULD BECOME SEVERE WITH STRONG WIND GUSTS. OUTLOOK... WED-THU...PATCHY AM FOG...OTHERWISE VFR. FRI...MAINLY VFR. CHC OF PM TSTMS WEST. SAT...VFR/MVFR WITH SCT SHWRS/TSTMS ASSOCD WITH COLD FROPA.
-- End Changed Discussion --
&& .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...STEINBUGL NEAR TERM...FITZGERALD SHORT TERM...STEINBUGL LONG TERM...RXR AVIATION...DANGELO/MARTIN

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