Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 120549 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 149 AM EDT SAT JUL 12 2014 .SYNOPSIS... WEAK HIGH PRESSURE WILL MOVE OFF THE EAST COAST SETTING UP AN INCREASINGLY HUMID AIRFLOW FROM THE SOUTH FOR THE WEEKEND. AN UNSETTLED WEATHER PATTERN WILL DEVELOP ACROSS THE REGION FOR THE FIRST PART OF NEXT WEEK...AHEAD OF A COLD FRONT THAT WILL CROSS THE AREA ON TUESDAY. COOLER AND DRIER AIR WILL MOVE IN FOR MUCH OF THE REMAINDER OF THE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... A BEUTIFUL SUMMER EVENING IS IN PROGRESS WITH LIGHT WINDS AND A NEARLY FULL SUPER MOON IN THE MAINLY CLEAR SKY. IT WILL REMAIN FAIR AND COMFORTABLE OVERNIGHT. SOME VALLEY FOG IS LIKELY CLOSE TO SUNRISE BUT AREAL COVERAGE WILL BE SMALL AND WILL DISSIPATE RAPIDLY AFTER SUNRISE. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/... SIMILAR WX PATTERN ON SATURDAY...THOUGH SURFACE HIGH WILL SLIDE A BIT EAST WITH A SLIGHTLY WARMER AIRMASS ALONG WITH SLIGHTLY HIGHER SURFACE DEWPOINTS. STILL CANNOT RULE OUT A SHOWER OR THUNDERSTORM DURING THE HEATING OF THE DAY ESPECIALLY OVER THE RIDGETOPS. MODELS SHOWING UPSTREAM CONVECTION MAY APPROACH THE WESTERN CWA LATE SAT NIGHT AND HAVE POPS THERE TO REFLECT THIS POSSIBILITY. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... HIGH AMPLITUDE RIDGE/TROUGH PATTERN DEVELOPS ACROSS THE MUCH OF NORTH AMERICA BEGINNING LATE IN THE WEEKEND...AND CONTINUES THROUGH THE FIRST HALF OF NEXT WEEK. THE BRUNT OF THE GREATEST 850-700 MB TEMP ANOMALIES AND ASSOCIATED BELOW NORMAL 500 MB HEIGHTS WILL BE AIMED AT THE LOWER OHIO VALLEY AND MID MISS VALLEY TUESDAY AND WEDNESDAY...WITH OUR REGION RESIDING ON THE ACTIVE/EASTERN SIDE OF THIS SLOW MOVING FEATURE. AN EXTENSIVE CHANNEL OF HIGH PWAT AIR WILL PRECEDE THE INITIAL COLD FRONT AND STRETCH FROM THE MIDWEST TO THE NEW ENGLAND STATES BY SUNDAY MORNING...BEFORE GRADUALLY SHIFTING SE ACROSS THE FCST AREA THROUGH EARLY TUESDAY. LLVL MOISTURE CONVERGENCE ANOMALIES WILL CLIMB TO NEARLY 3 STANDARD DEVIATIONS ABOVE NORMAL FOR SUNDAY /ACROSS THE NWRN HALF OF THE STATE...AND FOR MONDAY ACROSS CENTRAL AND SERN PENN/. AS HIGHER PWATS SURGE EAST INTO THE REGION AND CLIMB TO NEARLY 2.0 INCHES DURING THE DAY SUNDAY...INSTABILITY WILL QUICKLY RAMP UP WITH SEVERAL SREF MEMBERS INDICATING OVER 2000 J/KG ACROSS THE THE WRN HALF OF PENN. THE COMBINATION OF THE HIGH CAPE AND RELATIVELY STRONG...30-40KT SWRLY 850 MB WINDS WILL YIELD A RISK OF A FEW SVR TSRA SUNDAY AFTERNOON AND EVENING ACROSS THE NW MTNS. SPC/S DAY 4 OUTLOOK SHIFTS THE MAIN THREAT AREA TO THE SE HALF OF THE STATE AS THE SFC COLD FRONT AND INCREASING DIFFLUENCE ALOFT SPREADS SE ACROSS THE CWA. TRICKY CALL FOR MONDAY NIGHT AND TUESDAY AS THE BULK OF COOLING ALOFT AND BEST LARGE SCALE FORCING /ASSOC WITH THE RIGHT ENTRANCE REGION OF A 100 KT...300 MB JET/ MOVES OVERHEAD. PAINTED IN CHC POPS FOR SHRA...AND ISOLATED-SCT TSRA FOR NOW. HOWEVER...CAN EASILY SEE THIS APPROX 24 HOUR PERIOD FEATURING MORE NUMEROUS SHRA AND TSRA. AS ADDITIONAL ENERGY IS DRIVEN SSE INTO THE BACK SIDE OF THE HIGH AMPLITUDE MIDWEST TROUGH...PROLONGED HIGH PWAT AIR /AND LIFT BENEATH THE RIGHT ENTRANCE REGION OF THE AFOREMENTIONED UPPER JET/ MAY LINGER ACROSS THE SERN ZONES WITH SCATTERED...MAINLY AFTERNOON TSRA WEDNESDAY AFTERNOON. THE PATTERN OVER THE NRN CONUS AND SRN CANADA APPEARS TO DE- AMPLIFY LATER NEXT WEEK AS THE EASTERN U.S. TROUGH BEGINS TO SHEAR OUT TO THE NE. THE DRIEST PERIOD OF THE LONG TERM WILL BE THURSDAY AND FRIDAY...THOUGH SOME ISOLATED CONVECTION STILL CANT BE RULED OUT EITHER OF THOSE TWO DAYS. TEMPS START OUT AOA NORMAL PRECEDING THE CFROPA SUNDAY...AND PERHAPS MONDAY ACROSS THE SE ZONES...THEN COOL TO AT LEAST 4-6F BELOW NORMAL FOR DAYTIME HIGHS TUESDAY THROUGH THURSDAY. TEMPS WILL LIKELY REBOUND TO NEAR NORMAL LATE NEXT WEEK. && .AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
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MCLEAR SKIES AND A NEARLY CALM WIND SHOULD PROMOTE PATCHY FOG EARLY THIS MORNING...MAINLY ACROSS SOUTHEAST PA WHERE SOIL MOISTURE REMAINS THE HIGHEST. COND CLIMATOLOGY SUGGESTS IFR CONDS ARE A REAL POSSIBILITY AT KLNS BTWN 09Z-12Z. ELSEWHERE...A COMBINATION OF LAMP GUIDANCE...RAP OUTPUT AND COND CLIMATOLOGY SUGGEST IFR CONDS ARE UNLIKELY. ANY FOG SHOULD BURN OFF BY 12Z...AS DIURNAL HEATING CAUSES LOW LVL MOISTURE TO MIX OUT. A WEAK TROUGH OF LOW PRES MOVING INTO THE STATE COULD TRIGGER ISOLD TSRA DURING THE AFTN ACROSS THE SUSQ VALLEY. ALTHOUGH NOT LIKELY...CAN/T RULE OUT A BRIEF VSBY REDUCTION FROM ONE OF THESE TSRA AT KIPT...KMDT OR KLNS. OUTLOOK... SAT...NO SIG WX EXPECTED. SUN-TUE...BRIEF...MAINLY PM...THUNDERSTORM IMPACTS POSSIBLE. WED...NO SIG WX EXPECTED.
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&& .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...ROSS NEAR TERM...ROSS SHORT TERM...ROSS LONG TERM...LAMBERT/RXR AVIATION...FITZGERALD

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