Area Forecast Discussion
Issued by NWS State College, PA

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 221123 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 623 AM EST SAT NOV 22 2014 .SYNOPSIS... HIGH PRESSURE WILL BRING TRANQUIL CONDITIONS OVERNIGHT. A PLUME OF MOISTURE STREAMING NORTHEAST FROM THE OHIO VALLEY...IN ASSOCIATION WITH A WARM FRONT...WILL BRING CLOUDS AND SOME LIGHT FREEZING RAIN TO THE NORTHWEST MOUNTAINS SATURDAY MORNING AND EARLY SATURDAY AFTERNOON...WHILE THE REST OF CENTRAL AND SOUTHERN PENNSYLVANIA STAYS MAINLY DRY. AN APPROACHING STORM SYSTEM WILL BRING RAIN TO THE AREA SUNDAY NIGHT INTO MONDAY. TEMPERATURES WILL BE ON A ROLLER COASTER RIDE OVER THE NEXT SEVERAL DAYS...CLIMBING WELL ABOVE NORMAL ON MONDAY BEFORE TRENDING COLDER BY THANKSGIVING DAY. && .NEAR TERM /THROUGH TONIGHT/... LATEST SFC ANALYSIS SHOWS SFC HIGH BEGINNING TO MOVE OFFSHORE OVER SOUTHEAST VIRGINIA...WHILE RETURN FLOW HAS BROUGHT SOUTHERLY WIND SHIFTS INTO WESTERN AND SOUTH CENTRAL PORTIONS OF PENNSYLVANIA. MID AND HIGH CLOUD INCREASING OVER NORTHEAST OH WHILE MID TO LOWER CLOUD LAGS BACK OVER CENTRAL AND WEST CENTRAL OHIO AT THIS HOUR. MAIN CONCERN THIS MORNING IS TIMING OF PRECIPITATION ONSET WITH VERY COLD BOUNDARY LAYER AND SFC TEMPS ACROSS NORTH CENTRAL AND NORTHWEST PA THIS MORNING. LATEST MODEL DATA INDICATES A SLIGHT LAG FROM PREVIOUS THINKING IN TIMING OF ONSET OF PRECIP...BUT RESULT IS STILL THE SAME WITH MELTED HYDROMETEORS SUPERCOOLING AS THEY FALL THROUGH SUB FREEZING BOUNDARY LAYER IN THE 14Z TO 20Z TIMEFRAME. LATEST HRW-ARW INDICATES FZRA MAY EXTEND BEYOND 18Z FROM THE LYCOMING VALLEY TO THE ENDLESS MOUNTAIN REGION OF NORTHEAST PA...WHICH COULD PROMPT EXPANSION OF CURRENT WSW FOR FREEZING RAIN COVERING FROM THIS MORNING THROUGH THE MIDDAY HOURS. STILL A FEW MORE HOURS OF COOLING TO GO BEFORE CLOUDS BEGIN TO INCREASE APPRECIABLY...SO AS PREVIOUS SHIFT NOTED...THE TIMING IS PERFECT TO ALLOW FOR MAXIMUM RADIATIONAL COOLING BEFORE SIG CLOUD INCREASE...FOLLOWED BY A STUBBORN AND STRONG SFC-BASED INVERSION. BY MID AFTERNOON...MOST OF THE AREA WILL HAVE WARMED ABOVE FREEZING. HRW-ARW AS PREVIOUSLY NOTED HOLDS ONTO A POCKET OF FZRA BETWEEN 18Z AND 20Z NORTH OF KIPT. THINK THERE WILL BE LITTLE OR NO MEASURABLE PRECIP TO THE SOUTHEAST OF A LINE FROM KJST...TO KUNV AND KIPT /THOUGH PLENTY OF CLOUDS SHOULD BE AROUND FOR THE LATE MORNING AND AFTERNOON HOURS. AS A RESULT OF THE LIMITED INSOLATION AND PRECIP...HIGHS WILL BE NEARLY 10F BELOW NORMAL. SHOWERS WILL PERSIST ACROSS THE NORTHERN HALF OF THE STATE THROUGH THE EVENING HOURS BEFORE STARTING TO DECREASE WELL AFTER MIDNIGHT. SOME POCKETS OF FZRA ARE POSSIBLE ACROSS THE NORTHERN TIER...BUT EXPECT MOST AREAS TO HAVE WARMED ABOVE FREEZING BY TONIGHT. CLEARING FROM SOUTH TO NORTH MEANS SOUTHERN AREAS WILL LIKELY BE COOLER THAN THE NORTH...AND LOWS WILL RANGE FROM THE UPPER 20S SOUTH TO THE LOWER TO MIDDLE 30S NORTH. && .SHORT TERM /SUNDAY/... SHORTWAVE RIDGING BUILDS ACROSS THE OHIO VALLEY AND ACROSS PA ON SUNDAY...PROVIDING FAIR WEATHER FOR MUCH OF THE DAY...AND A MUCH MILDER AFTERNOON THANKS TO FRESHENING SOUTHERLY BREEZES IN THE RETURN FLOW AROUND THE OFFSHORE SFC HIGH. MAXES WILL NOT ONLY CRACK 40 THROUGHOUT FOR THE FIRST TIME IN SEVERAL DAYS...BUT SOAR ABOVE 50 ACROSS THE SOUTH. CONDITIONS WILL DETERIORATE FROM SOUTH TO NORTH IN THE MID TO LATE AFTERNOON AS A SHORTWAVE TROF LIFTS ENE FROM THE MID TENNESSEE RIVER VALLEY...ACCOMPANIED BY A 40+KT 850 MB JET SWINGING NORTH OF THE MASON DIXON LINE BETWEEN 20Z SUN AND 00Z MON. THIS WILL TOUCH OFF NUMEROUS SHOWERS IN THE MID TO LATE AFTERNOON FROM SOUTH TO NORTH...BUT IT APPEARS THE BULK OF ACTIVITY WILL ARRIVE AROUND OR AFTER 00Z MON. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
-- Changed Discussion --
MODELS CONTINUE TO SHOW SPOTTY/LIGHT PCPN OVER THE NRN TIER SAT NGT INTO EARLY SUNDAY WITHIN ZONE OF RELATIVELY STRONG H85 MSTR FLUX AND LOW-MID LVL WAA ASSOCD WITH 40-50KT WSW LLJ ON THE NW PERIPHERY OF SFC HIGH PRESSURE MOVG OFF THE MID ATLC COAST. A FEW WEAK SHORTWAVES CROSSING THE ERN GREAT LAKES MAY PROVIDE ADDNL LIFT. PTYPES ARE FCST TO BE PLAIN RAIN OVER THE NW ZONES WITH LOW CONFIDENCE IN -ZR OVER THE NERN 1/2 OF THE CWA WHERE 2M TEMPS SHOULD BE AROUND 32F PER MULTI-MODEL/MOS BLEND. ALTHOUGH IT WILL BE CLOUDY...MOST LOCATIONS EXPERIENCE A GOOD DEAL OF DRY WX ON SUNDAY WITH TEMPS MODERATING INTO THE MID 40S TO LOW 50S. THE LATEST MODEL AND ENSEMBLE GUIDANCE CONTINUES TO INDICATE A HIGHLY AMPLIFIED UPPER AIR PATTERN DEVELOPING NEXT WEEK. THE 500MB CONFIGURATION WILL FEATURE ANOMALOUS RIDGING ALONG THE WEST COAST AND IN THE WESTERN ATLANTIC WITH A FULL-LATITUDE TROUGH CARVING OUT OVER THE CENTRAL AND ERN U.S. PHASING OF SPLIT-STREAM ENERGY WILL YIELD A DEEP 980MB LOW /-3 TO -4 STD MSLP/ LIFTING NWD THROUGH GREAT LAKES INTO SERN CANADA ON MONDAY. STRONG SLY FLOW AHEAD OF THE TRAILING COLD FRONT WILL BRING A SURGE OF HIGH PWAT AIR INTO THE REGION WHICH WILL SUPPORT WIDESPREAD LIGHT TO MODERATE RAINFALL SUN NGT. RAISED POPS INTO THE CATEGORICAL RANGE ABOVE WPC AND IN-LINE WITH THE MEAN ECENS MOS. TEMPERATURES SHOULD PEAK ON MONDAY 10-20F ABOVE NORMAL /NEAR RECORD HIGHS/ BEFORE THE FROPA MONDAY NIGHT USHERS IN COLDER AIR. CONFIDENCE IS INCREASING IN COLDER TO BELOW AVG TEMPERATURES HEADING INTO THANKSGIVING AS THE GLOBAL MODELS AND ENSEMBLES ARE SUGGESTING PERSISTENCE OF THE ERN CONUS MEAN TROUGH. FINALLY...THERE IS UNCERTAINTY/LOW CONFIDENCE IN POTENTIAL IMPACTS ASSOCIATED WITH ONE OR MORE WAVES DEVELOPING IN THE WRN ATLC DURING THE MIDDLE TO SECOND HALF OF NEXT WEEK. THIS SITUATION WILL CONTINUE TO BE WATCHED AS THE WRN PERIPHERY OF THE MSTR SHIELD MAY CONTAIN SNOW. SOLUTIONS FROM THE 00Z SAT SUITE ARE STILL VERY MUCH MIXED...WITH GEFS SOLUTIONS LARGELY FOCUSED ON A MOSTLY OFFSHORE STORM TO AFFECT THE FISHES...WHILE OPERATIONAL ECMWF SHOWS MUCH MORE WIDESPREAD INLAND SNOWFALL IMPACTS ON WEDNESDAY... ONE OF THE BUSIEST TRAVEL DAYS OF THE YEAR. STAY TUNED.
-- End Changed Discussion --
&& .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
A WARM FRONT WILL LIFT NORTH ACROSS THE STATE TODAY. MOISTURE ALONG THE FRONT WILL LEAD TO VFR CONDS AND SOME PCPN LATER SAT MORNING INTO SAT AFTN MAIN ACROSS THE NRN SECTIONS...MAINLY AFFECTING KBFD. WITH COLD SFC TEMPS IN PLACE A PERIOD OF FREEZING DRIZZLE/FREEZING RAIN POSSIBLE THROUGH THE MORNING...BEFORE TURNING TO RAIN THIS AFTERNOON. MOST OTHER SITES SHOULD REMAIN PRIMARILY VFR. AS A STRONG LOW LEVEL JET WILL MOVE OVER THE REGION...LLWS WILL BE POSSIBLE FOR AIRFIELDS IN THE NORTHERN HALF OF THE STATE. THE WINDS ALOFT WILL CONTINUE TO INCREASE ABOVE SFC WINDS...WHICH WILL BEGIN THE DAY LIGHT AND VARIABLE AND THEN SWITCHING TO LIGHT SOUTHERLY TO SOUTHWESTERLY. THE LLWS WILL CONTINUE THROUGH MOST OF THE DAY BEFORE RELENTING TONIGHT. OUTLOOK... SUN...MAINLY VFR WITH A CHANCE OF RAIN SHOWERS NORTH. MON...MVFR WITH RAIN SHOWERS. TUE...MVFR WITH SNOW SHOWERS OVER WESTERN HIGH TERRAIN. VFR ELSEWHERE. WED...MVFR WITH SNOW SHOWERS OVER NORTHWESTERN HIGH TERRAIN. VFR ELSEWHERE.
-- End Changed Discussion --
&& .CTP WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR PAZ004>006-010-011-017.
-- End Changed Discussion --
&& $$ SYNOPSIS...DEVOIR/LA CORTE/LAMBERT NEAR TERM...DEVOIR/LAMBERT SHORT TERM...DEVOIR/LA CORTE/LAMBERT LONG TERM...DEVOIR/STEINBUGL AVIATION...CERU/GARTNER

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