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 261935 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 335 PM EDT SAT JUL 26 2014 .SYNOPSIS... A SERIES OF DISTURBANCES WILL MOVE ACROSS THE FORECAST AREA THE SECOND HALF OF THIS WEEKEND AS A DEEP UPPER TROUGH DEVELOPS OVER THE NORTHEASTERN UNITED STATES. THERE WILL BE SEVERAL CHANCES FOR PRECIPITATION...INCLUDING STRONG TO POTENTIALLY SEVERE THUNDERSTORMS SUNDAY INTO SUNDAY NIGHT...BEFORE ANOTHER SHOT OF UNSEASONABLY COOL AIR MOVES IN AND REMAINS OVER THE REGION THROUGHOUT THE NEW WORK WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... ACROSS CENTRAL PA...A PRETTY QUIET AFTERNOON ONGOING WITH SCT FLAT CU AS RIDGE SLIDES BY ALOFT. BUT MOISTURE ADVECTING INTO THE OHIO VALLEY ALREADY SPARKING SOME CONVECTION AS IT NOSES TOWARD PA. DID BRING MENTION OF SCT SHOWERS TO NW LATE THIS AFTERNOON...WITH ANOTHER BATCH OF SHOWERS/SCT TSTMS POSS THIS EVE AS SHORTWAVE AND INCREASING MOISTURE BRING A NIGHTTIME SURGE IN INSTABILITY IN FROM THE WEST...WITH STRONGEST STORMS TO SW OF CWA. SHOWERS SHOULD DECREASE AS THEY PASS THE SPINE OF APPALACHIANS OVERNIGHT. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... SUNDAY SHAPING UP TO BE A POTENTIALLY BUSY DAY AS AN UNSEASONABLY STRONG UPPER LOW DROPS THROUGH THE LOWER LAKES AND TAKES AIM AT THE LOCAL AREA. SPC HAS OUTLOOKED REGION JUST TO OUR SW /INCLUDING PORTIONS OF OH-KY-WV/ WITH A MODERATE RISK WHICH LOOKS REASONABLE GIVEN THE STRENGTH OF THE APPROACHING DYNAMICS AND INSTABILITY. WE COULD BE VULNERABLE LOCALLY INTO THE EVENING GIVEN THE EXPECTED TIMING OF THE COLD FRONT ENTERING THE REGION AND THE AMOUNT OF UPSTREAM INSTABILITY/SHEAR THE SYSTEM WILL HAVE AVAILABLE. WHERE THE OHIO VALLEY DEVELOPMENTS TAKE PLACE TONIGHT WILL HAVE MUCH TO SAY ABOUT HOW FAR NORTH INTO CENTRAL PA THE STRONGEST STORMS WILL MANAGE TO MOVE. BUT THIS SYSTEM IS ROBUST ENOUGH THAT WE MAY INITIALLY SEE ONE WAVE OF STORMS DEVELOP ACROSS THE SOUTH DURING THE DAY...WITH A SECOND WAVE DEVELOPING FURTHER NORTH LATE IN THE AFTERNOON INTO THE EVENING. THE SOUTHERN STORMS LOOK TO HAVE THE HIGHEST POTENTIAL FOR LARGE HAIL/DAMAGING WINDS/EVEN AN ISO TORNADO...WITH NORTHERN STORMS MAINLY WIND PRODUCERS. FIRST HALF OF THE EVENING SHOULD STILL BE QUITE BUSY WITH ONGOING STORMS...WITH DECREASING ACTIVITY INTO THE OVERNIGHT BEHIND THE COLD FRONT. && .LONG TERM /MONDAY THROUGH SATURDAY/... ALL THE ACTION OF NOTE WILL BE PRETTY MUCH OVER BY MONDAY WITH POST FRONTAL SHOWERS GRADUALLY DIMINISHING IN COVERAGE AS THE LOW AND FRONT SLIDE THROUGH NEW ENGLAND. IN A PATTERN THAT LOOKS MORE LIKE IT BELONGS IN MID WINTER THAN MID SUMMER...AN ANOMALOUSLY DEEP UPPER TROUGH IS MADE TO SET UP OVER THE EASTERN US AND REMAIN IN PLACE ALL WEEK. THE DETAILS OF MINOR SHORTWAVES SLIDING INTO THE TROUGH DIFFER AMONG THE AVAILABLE GUIDANCE...BUT DEEP MOISTURE WILL HAVE MOVED EAST SO WE`LL BE LEFT DEALING WITH MAINLY DIURNAL INSTABILITY UNDER THE COLD AIR ALOFT. WE COULD SEE MORE SIGNIFICANT MOISTURE RETURN LATER IN THE WEEK AS THE GFS/GEFS/ECMWF ALL HINT AT THE UPPER TROUGH RETROGRADING A BIT...POSSIBLY PAVING THE WAY FOR SOME ATLANTIC MOISTURE TO WORK UP THE EASTERN SEABOARD. 500MB HEIGHTS IN THE 3-4STD DEV BELOW NORMAL RANGE AND 850 TEMPS OF 1-3 STD DEV BELOW NORMAL POINT TO THE MOST CERTAIN PART OF THE FORECAST BEING SEVERAL DAYS OF TEMPERATURES AVERAGING WELL BELOW NORMAL. A SLOW MODERATION CAN BE EXPECTED BY LATE IN THE WEEK. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... VFR CONDITIONS WILL PREVAIL ACROSS THE REGION INTO THE EVENING HOURS AS RIDGE ALOFT SLIDES THROUGH. SHOWERS AND POSS A TSTM WILL IMPACT KBFD THIS AFT AND EARLY EVE. TONIGHT...SHOWERS AND SCT TSTMS WILL SLIDE INTO WESTERN SECTIONS THIS EVE WITH BRIEF REDUCTIONS LIKELY. EASTERN SITES WILL REMAIN VFR. OVERNIGHT...SHOWERS WILL DECREASE AS THEY MOVE EAST...BUT LIGHT FOG/HAZE WILL BRING MVFR CONDITIONS LATE. SUNDAY...A COUPLE OF WAVES OF SHOWERS/TSTMS EXPECTED TO IMPACT THE AIRSPACE...AND SOME OF THESE WILL BE STRONG TO SEVERE AS A POTENT UPPER LEVEL LOW/COLD FRONT APPROACH. BEST TIMING IMPACTS WILL BE ACROSS THE SOUTH DURING THE DAY...AND STATEWIDE LATER SUN AFTERNOON THROUGH THE EVENING HOURS. WINDS WILL INCREASE AT ALL LEVELS...AND CONDITIONS WILL VARY WIDELY NEAR CONVECTION. OUTLOOK... SUN...SCT TSRA IMPACTS EXPECTED. MON...AM LOW CIG POSS W MTNS. TUE-THU...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RXR NEAR TERM...RXR SHORT TERM...RXR LONG TERM...LA CORTE AVIATION...RXR

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