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 041329 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 929 AM EDT FRI SEP 4 2015 .SYNOPSIS... ABOVE NORMAL TEMPERATURES WILL CONTINUE INTO NEXT WEEK WITH GRADUALLY DECREASING HUMIDITY LEVELS. ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON. HIGH PRESSURE WILL ENSURE FAIR AND DRY WEATHER FOR LABOR DAY WEEKEND. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AREAS OF FOG AND LOW CLOUDS CONTINUE ACROSS PARTS OF CENTRAL PA. THIS WILL CONTINUE TO DISSIPATED THROUGH LATE MORNING RESULTING IN ANOTHER MOSTLY SUNNY...WARM AND HUMID DAY ACROSS THE REGION. MAXES STILL LOOK TO BE COOLER ON THE WHOLE...BUT STILL MUCH ABOVE NORMAL. HEIGHTS RISE TODAY OVER THE LOWER LAKES AND NEW YORK STATE. THE RIDGE WILL END UP SQUASHING THE LOW OFF TO THE WEST AND THE SFC HIGH SLIDES DOWN FROM THE NORTH/NORTHEAST. DAYTIME HEAT/INSTABILITY WILL ONCE AGAIN FIRE UP CONVECTION. THE RIDGE AND ADVANCING SFC HIGH WILL PROBABLY SUPPRESS CONVECTION IN THE NORTH...BUT WILL STILL CARRY A VERY LOW CHC POP THERE IN THE AFTERNOON. THE GREATER COVERAGE OF SHRA/TSRA WILL LIKELY BE OVER THE SRN TIER...ESPECIALLY THE LAURELS. THE EXPECTED COVERAGE WILL BE WORTHY OF AT LEAST A 50 POP...BUT WILL KEEP THEM BELOW 60 FOR NOW. THE WESTERN FRONT WILL ALSO BE A PLACE WHERE STORMS COULD FIRE UP. PWATS IN THE 1.5-1.7 INCH RANGE IN THE WEST AND SOUTH TODAY MEANS THAT A FEW CELLS COULD PRODUCE HEAVY DOWNPOURS AL A THURSDAY. 8H TEMPS WILL RUN ABOUT 2C LOWER TODAY VS THURSDAY THUS...THE MAXES WILL PROBABLY STAY A FEW DEGS F COOLER AS WELL. WINDS REMAIN LIGHT...BUT BECOME MORE EASTERLY THROUGH THE DAY AS THE SFC HIGH NOSES IN FROM THE NE. && .SHORT TERM /7 PM THIS EVENING THROUGH 6 PM SATURDAY/... CONVECTION ONGOING AT THE START OF THE PERIOD MAY BE THE LAST OF THE RAIN FOR A FEW DAYS. EXPECT SHRA/TSRA TO WANE THROUGH THE EVENING. THE INTERESTING/CHALLENGING PART OF THIS FORECAST MAY BE THE CLOUD COVER TONIGHT AND SAT MORNING AND RESULTANT MINS/MAXES. THE NAM IS PRETTY AGGRESSIVE IN ADVECTING LOW CRUD/STRATUS IN FROM THE EAST/SOUTHEAST TONIGHT AND PILING IT UP IN THE MOUNTAINS. HOWEVER...THE GFS IS NOT SO BULLISH ON THE LOW LEVEL MOISTURE. IT STILL MAKES LOWER CLOUDS /BELOW 8H/ BUT IS MORE NORTHEASTERLY WITH THE WINDS ON THE SRN PERIPHERY OF THE HIGH. THUS...MORE DRY AIR IS SEEN ADVECTING INTO THE AREA IN THE GFS SOLUTION. THIS ALLOWS THE MARITIME AIR/CLOUDS TO DRY OUT QUICKLY WITH MINIMAL MIXING. THE TROUBLE WITH THE DRIER SOLUTION IS THAT WE HAVE BEEN PRETTY MUGGY AND THE MDL OMEGA FIELDS DO NOT PORTRAY SOME OVERWHELMING DOWN-MOTION. IN FACT...THEY ARE PRETTY NEUTRAL. VERY ISOLATED DIURNAL CONVECTION IS POSSIBLE IN THE FAR WEST/SOUTHWEST ON SAT...BUT THE PWATS WILL BE MUCH LOWER - ONLY RANGING FROM 1 INCH IN THE NE TO 1.25 IN THE WEST. AT THIS POINT...THE MOST PROBABLE SOLUTION IN OUR WEAK FLOW IS THAT THE SFC HIGH STAYS UP OVER NEW ENGLAND AND THE DRY AIR MAKES ONLY SLOW PROGRESS TO MOVE ACROSS THE REGION. WILL KEEP IT MORE CLOUDY AND COOLER IN THE FIRST PART OF THE DAY AND KEEP MAXES SHORT OF GFS-MOS GUIDANCE. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... NOT MUCH TO CHANGE IN A SLOWLY EVOLVING EXTENDED FORECAST. HIGH PRESSURE SHOULD MAINTAIN DRY WEATHER SUNDAY-MONDAY. LEAD COLD FRONT ADVANCING EWD FROM THE GREAT LAKES/MIDWEST AND POTENTIAL ONSHORE FLOW MSTR MAY IMPACT THE FCST BY TUESDAY WITH SCT TSTMS POSS...BUT A CONSENSUS SOLUTION HOLDS BACK HIGHER POPS UNTIL WED OR MAYBE EVEN THU IN ASSOCIATION WITH A STRONGER SHORTWAVE/SFC COLD FRONT. SO TIMING DIFFS WILL NEED TO BE RESOLVED AS THE RIDGE SLOWLY BREAKS DOWN. THE GLOBAL NUMERICAL MODELS/ENSEMBLES ARE COMING INTO BETTER AGREEMENT ON A PATTERN CHANGE DURING THE SECOND HALF OF NEXT WEEK WITH A SHUFFLING OF THE LONGWAVE FLOW ALLOWING EWD PROGRESSION OF THE WESTERN TROUGH INTO THE CENTRAL STATES AND RECENT RIDGE OVER THE EASTERN UNITED STATES OFF THE COAST INTO THE WRN ATLC. THIS SHOULD EVENTUALLY BRING AN END TO THE RECENT HOT/DRY SPELL. A RETURN TO SEASONAL TEMPERATURES AND MORE ACTIVE PCPN PATTERN SEEMS PROBABLE BY NEXT WEEKEND IN THE NEW FLOW REGIME. && .AVIATION /13Z FRIDAY THROUGH TUESDAY/... LOCALLY DENSE FOG AND LOW CIGS PERSIST IN SOME OF THE VALLEYS OF CENTRAL PA. FOG AND ASSOCIATED REDUCTIONS SHOULD LIFT AND DISSIPATE THROUGH 15Z. THE REST OF THE DAY WILL FEATURE WIDESPREAD VFR CONDS AND LIGHT WINDS. HOWEVER...A COLD FRONT BACKING IN FROM THE EAST WILL SPAWN SCT PM SHRA/TSRA...MAINLY ACROSS SOUTHERN PA. A BRIEF VIS REDUCTION IS POSSIBLE IN A FEW SPOTS FROM THESE STORMS...MAINLY BTWN 18Z-00Z. A MOIST SERLY FLOW BEHIND THE COLD FRONT WILL LIKELY PRODUCE SOME LOW CIGS ACROSS THE MTNS OF CENTRAL PA TONIGHT AND EARLY SAT AM. OUTLOOK... SAT...AM LOW CIGS POSS...MAINLY KBFD/KJST. SUN-TUE...PATCHY AM FOG POSS...MAINLY KBFD/KIPT. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO/GARTNER NEAR TERM...DANGELO/GARTNER SHORT TERM...DANGELO LONG TERM...RXR/STEINBUGL AVIATION...FITZGERALD/GARTNER

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