Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 290354 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 1154 PM EDT SUN JUN 28 2015 .SYNOPSIS... A WEAK RIDGE OF HIGH PRESSURE WILL CROSS THE STATE MONDAY ACCOMPANIED BY FAIR AND MILDER WEATHER. A WAVE OF LOW PRESSURE WILL HEAD OUT OF THE OHIO VALLEY...BRINGING INCREASING CLOUDS AND THE CHANCE FOR SHOWERS MONDAY NIGHT INTO TUESDAY MORNING WITH SCATTERED THUNDERSTORMS TUESDAY AFTERNOON. A BROAD UPPER LEVEL TROUGH WILL REMAIN OVER THE EASTERN U.S. AND GREAT LAKES REGION DURING THE MIDDLE AND LATTER PART UPCOMING WEEK. EXPECT AN UNSETTLED WEATHER PATTERN ALONG WITH NEAR TO BELOW NORMAL TEMPERATURES HEADING INTO THE FIRST WEEK OF JULY. && .NEAR TERM /UNTIL 7 AM MONDAY MORNING/... 10 PM... CLOUDS BREAKING UP OVER A GOOD PORTION OF THE REGION. TEMPS ON TRACK WITH LITTLE DEVIATION EXPECTED FROM GOING FCST FOR THE REST OF THE NIGHT. GRADIENT SLACKENS...BUT DEWPOINTS ARE LOWERING. FOG NOT MUCH OF A WORRY. HAVE LOWERED POPS AND KEPT MENTIONS OF SHRA TO THE NRN MTNS LATER TONIGHT. LOW CLOUDS ARE POSSIBLE ALONG THE WRN HIGHLANDS WITH UPSLOPE FLOW STILL UNDER THE INFLUENCE OF THE UPPER LOW. BUT BY 09Z...ALL CYCLONIC CURVATURE SEEMS WELL TO THE NE AND THERMAL TROUGH AT 8H OFF INTO ERN PA. THIS SHOULD HELP TO DECREASE THE CLOUD COVERAGE EVEN FURTHER OVERNIGHT...ESP DOWN WIND OF THE ALLEGHENIES. PREV... DEEP UPPER LOW CENTERED OVER WESTERN NEW YORK STATE THIS AFTERNOON WILL SPIN OFF TO THE NORTHEAST LATER TONIGHT...BUT NOT BEFORE BRINGING ADDITIONAL/NUMEROUS SHOWERS ACROSS MUCH OF THE NORTHERN AND WRN MTNS OF PENN INTO THIS EVENING. RAINFALL AMOUNTS WILL GENERALLY BE JUST A FEW...TO SVRL HUNDREDTHS OF AN INCH IN MOST PLACES. THE SHOWERS WILL BECOME MORE ISOLATED TO SCATTERED AS WE HEAD THROUGH THE OVERNIGHT HOURS. SIMILAR TO A COLD SEASON NW FLOW PATTERN WITH LIMITED LLVL MOISTURE...MOST LOCATIONS ALONG AND TO THE SE OF THE INTERSTATE 99/RT 200 CORRIDOR WILL SEE LITTLE OR NO MEASURABLE RAIN FROM JUST A FEW LIGHT SHOWERS/SPRINKLES...SO POPS LATE TODAY AND TONIGHT ACROSS MUCH OF THIS REGION HAVE BEEN SET AT 20 PERCENT OR LESS. SKIES WILL STAY MOSTLY CLOUDY TO CLOUDY ACROSS THE CENTRAL AND NW MTNS...WHILE SOME PARTIAL CLEARING IS ANTICIPATED THROUGHOUT THE SUSQ VALLEY COMMUNITIES. LOW TEMPS TONIGHT WILL VARY FROM AROUND 50F IN THE NW TO AROUND 60F IN THE SE. && .SHORT TERM /7 AM MONDAY MORNING THROUGH 6 PM MONDAY/... SEVERAL SHORTWAVE TROUGHS WILL TOP THE WRN CONUS RIDGE AND DIG SEWD ACROSS THE UPPER/MID MS VALLEY...THEN EWD INTO THE NRN MIDDLE ATLANTIC REGION EARLY IN THE UPCOMING WEEK. THESE FEATURES WILL REINFORCE A DEVELOPING LONG-WAVE TROUGH THAT SHOULD GRADUALLY SHIFT EAST ACROSS THE OH VALLEY AND REACH THE APPALACHIANS BY THE END OF TUESDAY/D3. THE LEAD SHORTWAVE CURRENTLY DIVING SEWD ACROSS THE UPPER MISS VALLEY AND NRN GLAKES REGION WILL DIG INTO IL/IN BY EARLY MONDAY MORNING AND GRADUALLY LOSE AMPLITUDE AS IT TRANSLATES DOWNSTREAM INTO THE UPPER OH VLY BY 00Z TUE. MODEL CONSENSUS KEEPS MUCH OF THE AREA DRY ON MONDAY...WITH INCREASING ALTO CU CLOUDS LATER MONDAY AFTERNOON AND EVENING IN THE MID LEVEL WARM ADVECTION PATTERN IN ADVANCE OF THE SHORTWAVE. THERE WILL BE AN INCREASING CHANCE FOR SHOWERS LATE MONDAY NIGHT/TUESDAY MORNING...WITH SCT TSTMS DVLPG TUESDAY AFTERNOON. SPC HAS A MARGINAL TSTM RISK FOR ALL OF CENTRAL PA ON DAY 3 /TUESDAY/...WITH POTENTIAL FOR ORGANIZED STORMS GIVEN SEASONALLY STRONG DEEP LAYER FLOW...COMBINED WITH AN AREA OF SLIGHTLY ABOVE PWAT AIR /ESPECIALLY ACROSS THE SE HALF OF PENN...ALONG AND AHEAD OF A LIKELY DEVELOPING LEE SFC TROUGH/. TEMPERATURES ARE FORECAST TO MODERATE BUT STILL AVG A FEW DEGREES BELOW NORMAL. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... AN AMPLIFIED FLOW PATTERN ALOFT IS EXPECTED TO PREVAIL ACROSS THE NORTH AMERICA IN THE MEDIUM RANGE WITH AN UPPER-LEVEL ANTICYCLONE SLOWLY MIGRATING NORTHWESTWARD FROM THE CENTRAL GREAT BASIN TO THE PACIFIC NORTHWEST COAST. A BROAD UPPER-LEVEL CYCLONE OVER NORTHERN HUDSON BAY WILL KEEP A TROUGH POSITIONED OVER THE LOWER 48 --- PRIMARILY EAST OF THE CONTINENTAL DIVIDE. THE NORTHWEST FLOW PATTERN EXPECTED WILL MIGRATE A SERIES OF MID-LEVEL DISTURBANCES SOUTHEASTWARD FROM WEST CENTRAL CANADA ACROSS THE UPPER GREAT LAKES AND MID-MISSISSIPPI VALLEY THROUGH THE BASE OF THE PERSISTENT TROUGH...PROMOTING PERIODS OF CLOUDS AND OPPORTUNITIES FOR RAINFALL CHANNELING EASTWARD ACROSS THE OHIO VALLEY INTO MID ATLANTIC REGION. THE EC/GEFS/GFS ARE IN FAIR AGREEMENT THROUGH FRIDAY ON THE TRACK OF THESE SYSTEMS. HOWEVER GIVE THE EPISODIC NATURE OF THE PATTERN...CONFIDENCE IS LOW IN TRYING TO PICK A DAY OR PERIOD WITH `BETTER` ODDS FOR RAIN. TEMPERATURES THOUGH ARE TRENDING UPWARD AND SHOULD CONTINUE TO DO SO INTO THE JULY 4TH HOLIDAY WEEKEND. THE MODELS DO DIVERGE INTO NEXT WEEK AND THE SOLUTION BECOMES DIVERGENT. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... IN THE WAKE OF THE SHOWERS THAT HAVE PRETTY MUCH ENDED ACROSS THE REGION...MVFR TO IFR CONDITIONS ARE WIDESPREAD ACROSS THE NORTHERN AND WESTERN MOUNTAINS INCLUDING KBFD AND KJST. MVFR CIGS EXIST ACROSS THE CENTRAL RIDGE/VALLEY AREAS...WITH VFR CONDITIONS TO THE EAST. SATELLITE TRENDS HAVE SHOWN A SIGNIFICANT EROSION OF THE LOWER CLOUD DECK OVER THE LAST 3 HOURS ACROSS THE SOUTHERN 2/3 OF CENTRAL PENNSYLVANIA. HOWEVER...CLOUDS CONTINUE TO HOLD TOUGH ACROSS THE NORTH IN REALATION TO THE LOW...AND UPSLOPE INTO THE RIDGES HELPING TO KEEP CLOUDS HERE AS WELL. WILL CONTINUE THE FORECAST OF IFR/LIFR IN THE NORTHERN AND WESTERN AREAS OVERNIGHT. AS WINDS SLACKEN...THERE IS A CHANCE FOR AREAS EXPECIALLY WHERE LOWER CLOUDS HAVE ERODED TO SEE FOG DEVELOPMENT OVERNIGHT. AT THIS TIME...HAVE NOT BROUGHT WIDESPREAD FOG VSBY RESTICTIONS INTO THE TAFS...AS WINDS ARE MAINTAINING THEMSELVES AT A RESPECTIBLE 5 TO 12 KNOTS IN MOST LOCATIONS. HOWEVER...SHOULD WINDS GO LIGHT OR CALM...FOG FORMATION COULD BECOME WIDESPREAD OVERNIGHT. ANY MORNING RESTRICTIONS WILL FADE AND VFR CONDITIONS EXPECTED FOR MUCH OF MONDAY. RESTRICTIONS ONCE AGAIN WILL LINGER LONGEST IN THE NORTH AND WEST...POSSIBLY THROUGH 16Z/18Z. UNSETTLED PATTERN WITH A SERIES OF FRONTS AFFECTING THE REGION MUCH OF NEXT WEEK. BEST CHANCES OF RESTRICTIONS WILL BE TUESDAY INTO WEDNESDAY. OUTLOOK... MON...MORNING RESTRICTIONS NORTH AND WEST...THEN GENERALLY VFR. TUE-WED...MAINLY VFR...BUT SOME POSSIBLE RESTRICTIONS IN SHRA/TSRA. THU-THU...AGAIN MAINLY VFR....BUT RESTRICTIONS POSSIBLE IN SHRA AND POSSIBLE TSRA. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO/LAMBERT NEAR TERM...DANGELO/LAMBERT SHORT TERM...LAMBERT LONG TERM...CERU/STEINBUGL AVIATION...JUNG

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