Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 312312 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 712 PM EDT SUN AUG 31 2014 .SYNOPSIS... A WARM AND HUMID SOUTHWEST FLOW WILL KEEP THE CHANCES FOR RAIN IN THE FORECAST THROUGH THE LABOR DAY HOLIDAY. A COLD FRONT WILL BRING A BREAK IN THE HUMIDITY FOR MID WEEK. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... UPPER SHEAR AXIS SLIDING ACROSS CENTRAL PA THIS EVENING...ORGANIZING MOST ACTIVE CONVECTION JUST SOUTHEAST OF YORK AND LANCASTER COUNTIES THIS EVENING IN A LINE FROM NORTHERN VA TO CENTRAL NJ. MOST CONVECTIVE ACTIVITY ACROSS MY AREA IS SANS LIGHTNING...BUT SOME BRIEF DOWNPOURS ARE OCCURRING IN THE SOUPY AIR MASS WHICH FEATURE PW BETWEEN 1.75" AND 2.00" ACROSS THE SOUTHERN HALF OF THE COMMONWEALTH. DEEP LAYER MOISTURE DROPS OFF TO 1.6" VALUES ACROSS THE NORTHWEST MOUNTAINS. WHILE THE NORTHERN PORTION OF THE AFOREMENTIONED UPPER TROF/SHEAR AXIS IS PUSHING INTO SOUTHEAST PA THIS EVENING...THE TAIL END OF THIS AXIS OVER THE CENTRAL APPALACHIANS WILL LIFT INTO N CENTRAL MARYLAND BY 12Z MON...CONTINUING SHOWER AND ISOLD THUNDERSTORM CHANCES THERE...WITH THE POSSIBILITY OF A STRIPE OF HEAVY RAINFALL FROM NORTHERN VIRGINIA NEWD TO CENTRAL OR SOUTHERN NJ WHICH COULD BRUSH MY SOUTHEAST COUNTIES. MODEL CONSENSUS FAVORS A SOLUTION SOUTH AND EAST OF THE LOWER SUSQ BUT WILL KEEP HIGHER POPS IN THAT REGION THROUGH LATE TONIGHT AND EARLY MONDAY GIVEN THE FORCING AND AVAILABILITY OF 2.00" PW FROM THE DEL MARVA REGION TO THE SOUTHEAST PIEDMONT REGION. SOMEBODY IN THOSE AREAS CAN SEE SEVERAL INCHES OF RAIN OVERNIGHT...BUT WE APPEAR AT THIS TIME TO BE FAR ENOUGH NORTH TO AVOID IT ACROSS THE LOWER SUSQ. TIME WILL TELL. LAST DETAIL IS THAT PLENTY OF LOW LEVEL MOISTURE WILL BRING SOME POTENTIALLY DENSE FOG AND LOW CIGS TO CENTRAL AND NORTHERN COUNTIES OVERNIGHT INTO EARLY MON. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... HIGH PWAT AIR REMAINS IN PLACE ON MONDAY. THOUGH ENVIRONMENT NOT AS FAVORABLE FOR WIDESPREAD RAINS WITH RISING UPPER HEIGHTS AND WEAK SHORTWAVE RIDGING...SCT SHOWERS AND ISO TSTMS WILL HAVE TO REMAIN IN THE FORECAST. DOESN/T LOOK LIKE A WASHOUT THOUGH. HIGHS WILL BE 3-5F ABOVE NORMAL ALONG WITH HIGHER HUMIDITY. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... OPERATIONAL MODELS CONTINUE TO SHOW A COLD FRONT SWINGING THROUGH THE STATE LATE TUESDAY. THIS WILL BRING A HEALTHY DOSE OF RAIN TO THE REGION...WITH SREF PLUME DIAGRAMS SHOWING UP TO ONE INCH OF PRECIP. HIGH PRESSURE WILL THEN BUILD IN FOR MIDWEEK...BRINGING A FEW DAYS OF MILD AND DRY WEATHER. AS THE HIGH MOVES OFF THE COAST LATE IN THE WEEK...MORE HUMID FLOW AND THE CHANCE OF RAIN WILL RETURN TO THE REGION. AT THIS POINT...THERE IS RELATIVELY GOOD CONSENSUS BETWEEN MODELS ON A COLD FRONT MOVING THROUGH PENNSYLVANIA SATURDAY BEFORE A COOLER AIRMASS MOVES OVER THE REGION FOR THE SECOND HALF OF THE WEEKEND. THIS UPCOMING WEEK WILL BE ONE OF THE RARE EXTENDED PERIODS OF WARMER THAN NORMAL TEMPERATURES WE HAVE SEEN THIS SUMMER. HIGH TEMPERATURES WILL CLIMB TO ALMOST 90 ACROSS THE SOUTH AND EAST ON TUESDAY AHEAD OF THE FRONTAL PASSAGE. THEN AN UPPER RIDGE WILL BUILD OVER THE EASTERN US FOR THE SECOND HALF OF THE WEEK...KEEPING HIGH TEMPERATURES AT OR SLIGHTLY ABOVE SEASONAL NORMALS FOR EARLY SEPTEMBER THROUGH SATURDAY. && .AVIATION /23Z SUNDAY THROUGH FRIDAY/... STEADY PRECIPITATION TRANSITIONING TO A MORE CONVECTIVE ENVIRONMENT AS WEAK TROUGH LIFTS INTO NEW ENGLAND WHILE CORE OF JET SLIPS ACROSS EASTERN PA...TAPPING INTO MUGGY AND MOST UNSTABLE AIR OVER SE PA. THIS REGION HAS SEEN SOME SUNSHINE TODAY...AND MAIN FOCUS OF STRONG TSTMS LATE THIS AFTERNOON MAY CATCH OUR SE CORNER /IN VICINITY OF KMDT-KLNS/ AND POINTS S AND E. FORECAST MID LEVEL LAPSE RATES ARE WEAK BUT SHEAR INCREASING WHICH IS AIDING IN SOME MORE ORGANIZED STORM DEVELOPMENT. REMAINDER OF CWA WILL SEE MVFR TO VFR CIGS ALONG WITH SCATTERED SHOWERS/ISOLATED TSTMS CONTINUE INTO THE EVENING HOURS...WITH A GRADUAL DIMINISHING OF THE ACTIVITY LATE THIS AFTERNOON AND THIS EVE. TONIGHT...MAIN ACTIVITY WILL CONTINUE TO BE IN VICINITY OF MY SE COUNTIES AS ANOTHER SHORTWAVE SLIDES UP THE APPALACHIANS AND MAY KEEP SHOWERS/TSTM IMPACTS ONGOING INTO THE OVERNIGHT. PLENTY OF LOW LEVEL MOISTURE WILL BRING MVFR TO IFR REDUCTIONS OVERNIGHT INTO EARLY MONDAY WITH LOW CLOUDS AND SOME POTENTIALLY WIDESPREAD DENSE FOG. OUTLOOK... MON...AM FOG POSS...ESP W MTNS. ISOLD PM TSRA IMPACTS POSS. TUE...SCT PM TSRA IMPACTS POSS. WED...PATCHY AM FOG POSS. THU...PATCHY AM FOG POSS. FRI...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RXR NEAR TERM...DEVOIR/RXR SHORT TERM...RXR LONG TERM...COLBERT AVIATION...RXR

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