Area Forecast Discussion
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000 FXUS61 KPBZ 201004 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 604 AM EDT MON APR 20 2015 .SYNOPSIS...
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A PASSING FRONTAL SYSTEM WILL RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS MORNING AND THROUGH THE AFTERNOON. UNSEASONABLY COOL TEMPERATURES CAN THEN BE EXPECTED THE REMAINDER OF THE WEEK AS AN AREA OF LOW PRESSURE PERSISTS OVER THE NORTHEAST.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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QUICK UPDATE TO HOURLY TEMPERATURES TO BETTER ALIGN WITH LATEST OBSERVATIONAL TRENDS. TEMPERATURES WERE ALSO MODIFIED FOR THIS AFTERNOON BASED ON LATEST TIMING OF THE COLD FRONT WHICH WILL BE PASSING OVER THE AREA TODAY...INCREASING TEMPERATURES UP ALONG THE RIDGES WHERE STRONG WAA WILL BE IN PLACE AHEAD OF THE BOUNDARY. WITH THE LATEST CHANGE IN TEMPERATURES...EXPECT NO PROBLEM FOR LOCATIONS FARTHEST EAST IN REACHING CONVECTIVE TEMPERATURES AND EXPECT THUNDERSTORM COVERAGE ASSOCIATED WITH THE FRONT TO INCREASE THIS AFTERNOON AS THE FRONT PUSHES EAST. THERE IS STILL A SLIGHT RISK FOR SOME STORMS TO BECOME SEVERE TODAY...WITH INCREASING POTENTIAL FROM WEST TO EAST. THE MAIN THREAT WITH ANY STORMS WILL BE DAMAGING WINDS...WITH THE POSSIBILITY FOR ISOLATED LARGE HAIL SECOND. SHOWER ACTIVITY ACROSS THE REGION WILL HAVE LARGELY ENDED BEFORE SUNRISE AS DRIER AIR WORKING INTO MID LEVELS BRINGS A 6-7 HOUR BREAK IN THE WEATHER. MAIN CHALLENGE FOR THE DAY IS AMOUNT OF THUNDERSTORM DEVELOPMENT AS SURFACE-BASED INSTABILITY WILL PLAY A LARGE ROLE. AT THIS POINT COVERAGE ACROSS EASTERN OHIO LOOKS TO BE TO BE THE MOST SCATTERED...INCREASING MORE AS YOU HEAD EAST WHERE TIMING OF TODAYS COLD FRONT WILL ALLOW FOR MORE SOLAR INSOLATION.LOOKING AT MODEL SOUNDING PROFILES INDICATE DAMAGING WIND GUSTS WILL BE POSSIBLE IF ENOUGH INSTABILITY DEVELOPS AHEAD OF THE FRONT...ESPECIALLY EAST OF THE OH/PA BORDER.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... WITH THE FRONT EAST OF THE RIDGES BY EARLY THIS EVENING...PRECIPITATION WILL LARGELY BE OVER BEFORE A LARGE TROUGH OF LOW PRESSURE SETTLES IN ACROSS THE REGION A WEAK IMPULSE MAINLY AFFECTS THE SOUTHERN COUNTIES WITH A FEW SHRA TUESDAY NIGHT. THE NEXT...MORE ORGANIZED...FRONTAL BOUNDARY ARRIVES WEDNESDAY WITH BETTER RAIN CHANCES AREAWIDE. BEHIND THE FRONT...BOUNDARY LAYER MAY BE ABLE TO COOL SUFFICIENTLY TO ALLOW SNOWFLAKES TO MIX IN NORTH OF PIT LATE WEDNESDAY NIGHT...BUT NO ACCUMULATION IS FORESEEN. COOLER TEMPERATURES ARE EXPECTED WITH VALUES BELOW AVERAGE THROUGH THE PERIOD. && .LONG TERM /THURSDAY THROUGH SUNDAY/... SOME ISOLATED SHOWERS WILL REMAIN THURSDAY MORNING...BUT WILL DIMINISH THROUGH THE DAY. GFS/ECMWF GENERALLY SHOW ONE SYSTEM IN THE REGION THROUGH THE EXTENDED FORECAST...BUT THE ECMWF IS SLOWER WITH THE SYSTEM AND ALSO MUCH FARTHER TO THE SOUTH. CONSIDERING ENSEMBLES SHOW GOOD SUPPORT FOR THE EUROPEAN SOLUTION...HAVE REMOVED THE LOW POPS THAT WERE IN THE FORECAST OVER THE WEEKEND. HOWEVER...MODELS DO SHOW AGREEMENT ON BROAD UPPER LEVEL LOW ACROSS NORTHEASTERN NORTH AMERICA...AND THIS WILL KEEP TEMPERATURES 5-10 DEGREES BELOW NORMAL THROUGH THE PERIOD. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... WINDS HAVE BEEN QUITE GUSTY DURING THE EVENING HOURS INTO THE OVERNIGHT PERIOD...BUT GUSTS SHOULD BEGIN TO DIMINISH AS WARM FRONT MOVES FROM SOUTH TO NORTH. ALONG WITH WIND GUSTS DIMINISHING...ANY LOW LEVEL WIND SHEAR AND SHOWER COVERAGE SHOULD ALSO DECREASE THROUGH SUNRISE. SLOW IMPROVEMENT FROM MVFR TO VFR CIGS SHOULD OCCUR THROUGH MID MORNING. SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A COLD FRONT ARE EXPECTED TO DEVELOP DURING THE LATE MORNING INTO EARLY AFTERNOON...ALTHOUGH WIND GUSTS OF 30 KTS ARE EXPECTED EVEN OUTSIDE OF THUNDERSTORMS. SOUTHERLY WINDS WILL VEER TO THE WEST DURING THE EVENING BEHIND THE FRONT. .OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/... PERIODIC RESTRICTIONS WILL BE POSSIBLE AS COLD UPPER LOW PRESSURE SETTLES JUST NORTH OF THE GREAT LAKES. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$

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