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. --
000 FXUS61 KCTP 060329 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 1029 PM EST THU MAR 5 2015 .SYNOPSIS... HIGH PRESSURE WILL BUILD SOUTHEAST INTO THE STATE FRIDAY AND SATURDAY. A STRONG UPPER-LEVEL RIDGE WILL BUILD INTO THE REGION EARLY NEXT WEEK. THIS SHOULD PROVIDE GENERALLY FAIR WEATHER AND SEVERAL DAYS OF NEAR NORMAL TEMPERATURES AND RELATIVELY DRY WEATHER. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
-- Changed Discussion --
AS OF 03Z...SKIES HAVE CLEARED ACROSS MOST OF CENTRAL PA AS ARCTIC HIGH PRES SYSTEM OVERSPREADS THE STATE. BACK EDGE OF MID LVL CLOUD DECK SHOULD CLEAR LANCASTER CO BY 05Z...AND PATCH OF STRATOCU OVR WARREN/MCKEAN COS SHOULD DIMINISH BY 06Z...AS INVERSION HGTS FALL. DIMINISHING WIND...CLEARING SKIES AND FRESH SNOW COVER SHOULD RESULT IN NEAR RECORD LOW TEMPERATURES OVERNIGHT...AVERAGING 5-10 BLW ZERO OVR THE NW MTNS...TO THE LOWER SINGLE DIGITS ACROSS THE LOWER SUSQ VALLEY. HOWEVER...A CALM WIND ACROSS THE ALLEGHENIES SHOULD ALLOW THE NORMALLY COLDER VALLEYS TO GET EVEN COLDER. LATEST RAP SUGGESTS A FEW LOCATIONS ACROSS THE NW COULD DIP AS LOW AS 15 BLW ZERO. AT THIS POINT...WE ARE COUNTING ON THE WIND TO DROP OFF ENOUGH TO MINIMIZE WIND CHILLS...SO NO HEADLINES ARE PLANNED AT THIS TIME.
-- End Changed Discussion --
&& .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... HIGH PRESSURE WILL PROVIDE A MUCH BRIGHTER DAY FRIDAY. FORECAST SOUNDINGS SUGGEST THE POTENTIAL FOR SOME STRATOCU TO GATHER UNDER THE STRONG SUBSIDENCE INVERSION ACROSS THE ALLEGHENY PLATEAU...BUT EVEN THERE A FAIR AMOUNT OF SUNSHINE SHOULD MANAGE TO MIX WITH ANY CLOUDS THAT FORM. MAX TEMPS SHOULD RANGE FROM 20-25F BLW NORMAL FRIDAY. 18Z GEFS MEAN 925MB TEMPS ARND -14C ARE SUPPORTIVE OF HIGHS FROM JUST THE UPPER TEENS OVR THE ALLEGHENY PLATEAU...TO THE L-M20S ACROSS THE SUSQ VALLEY. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... SFC HIGH PRESSURE RIDGE AXIS WILL MIGRATE EWD ACROSS THE MID ATLANTIC REGION FRIDAY NIGHT AND SETTLE INTO THE SOUTHEAST STATES ON SATURDAY. AN INCREASE IN SW GRADIENT WINDS AND CLOUDS ARE EXPECTED ACROSS THE NW HALF OF THE CWA IN ADVANCE OF A WEAK LOW MOVING ACROSS THE GREAT LAKES. MEANWHILE MAINLY CLEAR SKIES AND LIGHTER WINDS ACROSS THE LOWER SUSQ VALLEY SHOULD PREVAIL NEAR THE DEPARTING SFC RIDGE. THIS PATTERN FAVORS A NON-DIURNAL TREND WITH LOWS IN THE MID TEENS OCCURRING EARLY ACROSS THE NW MTNS FRIDAY NIGHT WITH A STEADY TO SLOW RISE INTO SATURDAY MORNING. A MORE TYPICAL NOCTURNAL TEMP CURVE SHOULD ALLOW TEMPS TO FALL TO AROUND 10F OVER THE LOWER SQV. BROAD UPPER CYCLONIC FLOW WILL CONTINUE INTO EARLY NEXT WEEK AS ADDITIONAL SHORTWAVE IMPULSES MOVE FROM CENTRAL CANADA THROUGH THE NORTHERN TIER OF THE U.S. THERE ARE FEWER DIFFERENCES NOTED OVERALL COMPARED TO PREVIOUS MODEL CYCLES WITH RESPECT TO THE TIMING AND DEPTH OF EACH IMPULSE. ONE IMPULSE WILL DRIVE A SURFACE WAVE AND ASSOCIATED FRONT THROUGH THE GREAT LAKES REGION ON SAT AND THEN INTO NEW ENGLAND ON SUN. AN ADDITIONAL IMPULSE WILL TAKE A SIMILAR TRACK THROUGH THE GREAT LAKES LATER SUN INTO EARLY MON ALONG WITH A WEAK FRONT. GIVEN THE FAST DEEPER LAYER WEST NORTHWEST FLOW OVER THE REGION...THE AMPLITUDE OF EACH IMPULSE SHOULD BE RATHER SMALL WITH MOISTURE AVAILABILITY QUITE LIMITED. THEREFORE EXPECT OCCASIONAL SNOW SHOWERS MAINLY OVER THE HIGHER TERRAIN OF THE NORTHERN ALLEGHENIES WITH 48 ACCUMS OF 1-2" POSSIBLE OVER THE NW MTNS BY 12Z MON. THE MODELS AND ENSEMBLE MEANS ARE AGREEABLE/CONSISTENT WITH THE MAIN THEMES OF THE LARGE SCALE PATTERN INTO NEXT WEEK. THESE INCLUDE AN INCREASINGLY ZONAL/PROGRESSIVE NRN STREAM FLOW ACROSS SRN CANADA...AND SRN ROCKIES/PLAINS INTO MEXICO MEAN TROUGH AND STRONG RIDGE E OF THE BAHAMAS. AS THE MEAN PATTERN ALOFT BECOMES INCREASINGLY FLATTER...CONFIDENCE IS RELATIVELY HIGH IN A MAINLY DRY PERIOD WITH STEADILY INCREASING/MODERATING TEMPERATURES TO AT OR SLIGHTLY ABOVE EARLY-MID MARCH CLIMATE NORMALS. && .AVIATION /04Z FRIDAY THROUGH TUESDAY/... CONDITIONS IMPROVED QUICKLY ACROSS THE SOUTHEAST LATE THIS AFTERNOON AS STORM SYSTEM BEGAN TO PULL AWAY FROM THE REGION. AT 00Z...CONDITIONS ARE VFR ACROSS ALL OF CENTRAL PA. A THICK MID-LEVEL DECK WILL SLOWLY DRIFT SOUTHEASTWARD... PERSISTING OVER THE SE THROUGH THE EVENING HOURS BEFORE SKIES CLEAR. ELSEWHERE...MAINLY CLEAR SKIES WILL BE THE RULE AS STRONG HIGH PRESSURE AREA BUILDS IN. A SMALL AREA OF MVFR STRATOCU COMING OFF OF LAKE ERIE MAY BRIEFLY IMPACT KBFD WITH MVFR CIGS...BUT IF IT REACHES THERE IT SHOULD BE SHORT-LIVED. WINDS THIS EVE WILL START OUT AROUND 10 MPH...BEFORE BECOMING LIGHT DURING THE OVERNIGHT HOURS. VFR PREVAILS ON FRI UNDER HIGH PRESSURE. WINDS TURN TO THE SOUTHWEST AT SPEEDS OF 5-10 MPH. OUTLOOK... FRI-SAT...MAINLY VFR. SUN-MON...MVFR WITH CHC -SHSN MAINLY NORTH AND WEST. VFR SE. TUE...NO SIG WX. && .CLIMATE... DAILY RECORD LOWS ARE IN SERIOUS JEOPARDY TONIGHT AT MANY LOCATIONS. THE RECORD LOW FOR MARCH 6TH AT HARRISBURG IS 7F SET BACK IN 1901 AND -1F AT WILLIAMSPORT SET IN 1978. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD/LA CORTE LONG TERM...STEINBUGL AVIATION...RXR CLIMATE...

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