Area Forecast Discussion
Issued by NWS State College, PA

Current Version | Previous Version | Text Only | 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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
928 FXUS61 KCTP 301848 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 248 PM EDT SAT APR 30 2016 .SYNOPSIS...
-- Changed Discussion --
A LARGE LOW PRESSURE AREA OVER THE CENTRAL U.S. WILL SLIDE TO THE EAST OVER THE NEXT FEW DAYS. EXPECT A PROLONGED PERIOD OF RAIN THROUGH AT LEAST MONDAY MORNING WHEN THE LOW MOVES TO THE EAST OF THE STATE. UNSETTLED WEATHER WILL CONTINUE NEXT WEEK WITH SEVERAL CHANCES FOR RAIN.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
VERY MUCH WARMER AIR WILL BE MOVING IN FROM THE WEST. THIS WILL BRING A BIG INCREASE IN MOISTURE AS WELL. BECAUSE OF THE PERSISTENT CLOUD COVER AND EASTERLY FLOW...THE TEMPS MAY NOT MOVE MUCH AT ALL THROUGH THE NIGHT...AND IT MAY EVEN NUDGE UP JUST A DEGREE IN THE WEST BY SUNRISE. THE TIMING OF THE RAIN ONSET SEEMS TO BE RATHER SIMILAR TO LAST MODEL CYCLE. THE WEST SHOULD GET WET AROUND OR JUST BEFORE SUNSET...BUT IT MIGHT TAKE UNTIL AFTER MIDNIGHT FOR THE RAIN TO WORK DOWN INTO THE EASTERN VALLEYS. HIGHEST PWATS WILL NOT BE UNTIL LATER TONIGHT...WHEN THEY PEAK IN THE 1.25-1.5 INCH RANGE. LLJET NEVER GETS ALL THAT FAST AND IS MORE OUT OF THE SW THAN E/SE WHERE THE DEEP AND CLOSE MOISTURE SOURCE IS. THIS FIRST WAVE OF LIFT LAST ALL NIGHT. THE VISBY MAY GET LOW IN THE SW/MTNS WHERE THE INVERSION GETS STEEP AND CLOUDS HUG THE HILL TOPS. KEPT MENTIONS OF FOG AND EXPANDED THEM A BIT AS WELL.
-- End Changed Discussion --
&& .SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
-- Changed Discussion --
THE WAVE GENERATING THE RAIN WILL BE GETTING TO THE EAST OF OUR LATITUDE IN THE MORNING...BUT RAIN WILL CONTINUE FOR AT LEAST THE MORNING IN THE EASTERN HALF OF THE AREA. THE WARMER AIR WILL TRY TO WORK DOWN TO THE SFC DURING THE DAY/AFTN BUT RESIDUAL MOISTURE MAY KEEP LOTS OF LOW CLOUDS IN PLACE. RAINFALL BY NOON WILL BE INTO THE 0.5 TO 1 INCH RANGE. THE LOW WILL MOVE INTO OH AND NW PA ON SUNDAY...OCCLUDING IT/S COLD AND WARM FRONTS AS IT DOES SO. A SECOND WAVE OF DECENT LIFT WILL COINCIDE WITH THE TRIPLE POINT INCHING INTO CENTRAL PA SUNDAY EVENING. WE WILL LIKELY BE IN AN AREA OF NVA AND DRYING ALOFT. SO FOR A WHILE IN THE DAYTIME ON SUNDAY...WE SHOULD BE IN A LULL. HOWEVER...IF SOME BREAKS CAN DEVELOP AND SOME MEAGER FORCING PASS OVERHEAD...WE MAY BE ABLE TO POP A FEW TALL SHRA/SHORT TSRA. BUT THE HEIGHTS WILL NOT HAVE FALLEN MUCH BY THAT TIME...AND THE CLOUD COVER MAY BE STICKING TIGHT. THE WARM SECTOR DOES GET RATHER CLOSE...THOUGH. THE WARM FRONT WILL BE BARELY INTO OR WILL BE HALTING AT THE LAURELS/ALLEGHENIES. THUS...LLVL SHEAR COULD BE MAXIMIZED THERE. A FEW ROTATING STORMS ARE POSSIBLE WITH LOWERED BUT PROBABLY ELEVATED INSTABILITY IN THAT S/W REGION. DUE TO THE PRESENCE OF ELEVATED INSTABILITY AND POSSIBILITY OF MIXING ACROSS THE REST OF THE AREA...WILL KEEP CHC/SCT TS IN THE FCST FOR THE AFTN/EVENING. MAXES WILL BE VERY MUCH DEPENDENT UPON THE AMOUNT OF SUNSHINE WHICH CAN BREAK THROUGH. A WARM START TO THE DAY WILL HELP US BUT THE PERSISTENT CLOUDS - ESP IN THE E - WILL LIMIT THE RISE. WILL GO WITH MAXES ONLY 5-6F HIGHER THAN MORNING TEMPS IN THE EAST...BUT MORE LIKE 10 OR 12F RISE IN THE WEST. THE WARM AIR MAY PUSH INTO THE AREA A BIT MORE OVERNIGHT...SO TEMPS SHOULD NOT FALL PAST THE U40S AND M50S.
-- End Changed Discussion --
&& .LONG TERM /MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
48-HOUR FORECAST RAINFALL TOTALS ENDING 00Z TUESDAY ARE 0.75 NORTH TO 1.25 INCHES SOUTH...WITH HIGHER AMOUNTS OVER THE WESTERN ALLEGHENIES AND SOUTHERN TIER COUNTIES WHERE MARGINAL INSTABILITY MAY ALLOW FOR CONVECTIVE ENHANCEMENT. THE FCST RAINFALL SHOULD HELP THE AREA RECOVER FROM /60-90+ DAY/ DEFICITS GENERALLY ON THE ORDER OF -2.00 TO -4.00 INCHES. THE LATEST DROUGHT MONITOR NOW HAS OVER HALF OF PENNSYLVANIA IN ABNORMALLY DRY /D0/ CONDITIONS WITH A SMALL AREA OF MODERATE DROUGHT /D1/ CONDITIONS FOCUSED OVER BEDFORD COUNTY. A PERIOD OF IMPROVING/DRY WEATHER IS LIKELY FROM MONDAY AFTERNOON THROUGH TUESDAY BEFORE THE PATTERN TURNS UNSETTLED INTO THE MIDDLE AND SECOND HALF OF NEXT WEEK. THE GLOBAL ENSEMBLE MEANS ALL SHOW AN AMPLIFIED/ANOMALOUS MEAN UPPER TROUGH DEVELOPING OVER THE ERN CONUS BUT THERE ARE STILL MULTIPLE SHORTWAVE PIECES OF THE FCST PUZZLE TO RESOLVE. THE GUIDANCE AGREES IN PRINCIPLE THAT AN ELONGATED AREA OF SFC LOW PRESSURE WILL BE NEAR OR ALONG THE EAST COAST/WRN ATLANTIC. HOWEVER QUESTION MARKS WITH THE DETAILS ALOFT LEADS TO LOW CONFIDENCE/PREDICTABILITY IN THE RAINFALL TIMING AND COVERAGE PATTERN. BELOW NORMAL HEIGHTS AND DEEPENING UPPER TROUGH SHOULD FAVOR RELATIVELY COOL TEMPERATURES VS. SEASONAL CLIMATOLOGY.
-- End Changed Discussion --
&& .AVIATION /18Z SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --
IFR AT JST WILL LIKELY BE SHORT-LIVED AS THE DEWPOINT HAS RISEN SOME. ELSEWHERE...THE MVFR CIGS IN THE CENTRAL TERMINALS AND VFR IN THE SE WILL CONTINUE FAIRLY STEADY STATE WITH THE PERSISTENT FLOW FROM THE E/SE. LOW PRESSURE APPROACHING THE OHIO VALLEY TONIGHT WILL SPREAD A LARGE SHIELD OF RAIN INTO THE REGION STARTING IN THE EVENING IN THE SW AND SPREADING TO COVER THE AREA BY MIDNIGHT. EXPECT THE WORST PERIOD OF CIGS/VIS IN THE LATE NIGHT UNTIL A FEW HOURS AFTER SUNRISE ON SUNDAY. WARM FRONT EXTENDING IN FROM THE MAIN LOW WILL TRY TO LIFT INTO THE CENTRAL MTNS...BUT WILL LIKELY STALL OVER SWRN/WRN PA. HOWEVER...SOME CLEARING IN THE DAYTIME COULD PRODUCE SCT SHRA/TSRA ACROSS ALL OF THE AREA. THE MAIN THREAT AREA FOR TSRA IS VCTY JST/AOO. A SECOND WIDE AREA OF RAIN/LOW CIGS/VIS WILL PUSH ACROSS AS THE MAIN SFC LOW PUSHES THROUGH SUN NIGHT/EARLY MONDAY MORNING. DRIER AIR WILL WORK IN FOR A VERY BRIEF TIME ON MONDAY. A WAVE RIDING THROUGH THE DEEP SOUTH AND MID-ATLANTIC STATES ON TUESDAY WILL PROBABLY SPREAD MORE RAIN INTO THE SE HALF OF THE AREA MON NIGHT/TUES. OUTLOOK... MON PM-TUE...RA POSS SE. TUE PM...NO SIG WX. WED...SHRA POSS. THU...IFR POSS IN RA/FG.
-- End Changed Discussion --
&& .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...LAMBERT/STEINBUGL AVIATION...DANGELO

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