Area Forecast Discussion
Issued by NWS

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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KPBZ 211254 AAB AFDPBZ AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE PITTSBURGH PA 854 AM EDT SUN SEP 21 2014 .SYNOPSIS... A COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS TODAY. HIGH PRESSURE WILL DOMINATE THE REMAINDER OF THE WEEK WITH DRY WEATHER. && .NEAR TERM /THROUGH MONDAY/... FCST WAS UPDATED TO REFLECT MORE AGGRESSIVELY THE CURRENT LINE OF SHWRS CROSSING FCST AREA. A LULL IN CNVCTN IS XPCD LATE THIS MRNG. A LINE OF SHWRS AND TSTMS XPCD TO DVLP AGAIN LATER THIS AFTN ALONG ADVCG CDFNT AS H5 JET DIGS FURTHER AND SHRTWV TROF ACQUIRES NEUTRAL TO NEGATIVE TILT. POPS WERE INCRD TO REFLECT CURRENT EXPECTATIONS. PREV DISCUSSION FOLLOWS... STILL CONCERNED OVER THE POTENTIAL FOR STRONG TO SEVERE STORMS LATE TODAY WITH THE PASSAGE OF A COLD FRONT. WIND FIELD IS IMPRESSIVE AND THE ATMOSPHERE DESTABILIZES AHEAD OF THE BOUNDARY. NAM IS CLEARLY THE STRONGEST WITH MESOSCALE FEATURES COMPARED TO OTHER OPERATIONAL MODELS. THIS LEADS ME TO BELIEVE THAT THE NAM MAY BE ON ITS OWN WITH ITS DEPICTION OF THE SITUATION SO WILL LEAN AWAY FROM IT. ANY CONVECTION THIS AFTERNOON WILL HAVE THE POTENTIAL TO PRODUCE GUSTY WINDS. WITH MIXING HEIGHTS RISING AHEAD OF THE FRONT...COULD STILL SEE STRONGER WIND GUSTS WITHOUT CONVECTION. OTHER LIMITING FACTORS WILL BE CLOUD COVER AND THE RISK FOR SCATTERED SHOWERS THIS MORNING. FOR A NAM SOLUTION TO COME TO FRUITION...WOULD NEED TO SEE CONVECTION FIRE AND GROW OVER THE GREAT LAKES ALONG THE FRONT AND THEN SUSTAIN ITSELF...THANKS TO THE HIGH SHEAR VALUES IN ITS SOLUTION. THE OTHER OPERATIONAL MODELS ARE NOT IN TOTAL AGREEMENT WITH THIS SCENARIO. FORECAST WILL SHOW SHOWERS THIS MORNING AND THEN SHOWERS/STORMS THIS AFTERNOON RIGHT ALONG THE FRONT. HAVE INCREASED WIND GUSTS DURING THE AFTERNOON. FRONT WILL PICK UP SPEED LATE THIS AFTERNOON AS STRONG SHORTWAVE TROUGH WILL DIG DOWN FROM THE WESTERN GREAT LAKES. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/... SHOWER/STORM CHANCES WITH THE FRONT WILL END IN THE EVENING OVER THE SOUTH. STRONG CAA WILL FOLLOW ON THE HEELS OF THE BOUNDARY AS THE TROUGH AXIS MOVE THROUGH LATE SUNDAY NIGHT. 85H TEMPS WILL DROP SOME 6-8 DEGREES SUNDAY NIGHT AS THE FLOW VEERS TO THE NORTHWEST. EXPECT A LARGE AREA OF STRTOCU TO QUICKLY COVER THE REGION. ITS POSSIBLE...WITH THE COLDER AIR AND NORTHWEST FLOW... SHOWERS COULD REDEVELOP...PARTICULARLY OVER THE NORTH AND RIDGES. HEART OF THE COLD AIR SETTLES IN OVER THE REGION MONDAY. EXPECT THE STRATOCU DECK TO REMAIN IN PLACE. LATEST FORECAST SOUNDINGS ARE SHOWING A THIN LAYER OF SATURATION WHICH WOULD LIKELY PREVENT ADDITIONAL SHOWER ACTIVITY ON MONDAY. NOTICEABLY COLDER 85H TEMP FORECAST MONDAY COMPARED TO PREVIOUS RUNS. THIS WILL NECESSITATE THE LOWERING OF TEMPS ON MONDAY. IF LATEST MODEL OUTPUT IS CORRECT...HIGHS MONDAY COULD BE 15 TO 20 DEGREES BELOW NORMAL. COLD AIR WILL QUICKLY RETREAT TO THE NORTHEAST MONDAY NIGHT AS THE ENTIRE UPPER LEVEL SYSTEM SHIFTS TOWARD THE EAST COAST. WAA WILL KICK IN MONDAY NIGHT ALLOWING SKIES TO CLEAR. SURFACE HIGH AND RIDGING ALOFT WILL PROVIDE A SUNNY AND COMFORTABLE DAY TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... DRY AND SEASONABLE PATTERN EXPECTED FOR THE LONG TERM. && .AVIATION /13Z SUNDAY THROUGH THURSDAY/... LINE OF SHWRS ADVCG ACRS RGN THIS MRNG...LKLY PROVIDING BRIEF IMPACTS TO KFKL/KDUJ. SCT CVRG XPCD SWD NEAR KPIT/KAGC/KBVI/KHLG... BUT THESE SHWRS WILL VACATE QUICKLY AND WILL PRODUCE ONLY LMTD MVFR RESTRICTIONS AND LCL WIND GUSTS TO 25KT. RETURN TO VFR CONDS XPCD LATE THIS MRNG BFR A SECOND LINE OF SHWRS AND TSTMS DVLPS MID-LATE AFTN ALONG ADVCG CDFNT. THIS LINE MAY PRODUCE STRONGER WIND GUSTS...QUITE PSBLY STRONG TO SVR. TIMING WILL BE DURG 20Z-24Z FROM W TO E. GENL VFR CONDS XPCD THEREAFTER. OUTLOOK.../MONDAY THROUGH FRIDAY/... STRATOCUMULUS BETWEEN 3-5KFT AGL WILL PERSIST THROUGH MONDAY...WITH VFR CONDITIONS EXPECTED THROUGH THE WEEK AS THE REGION REMAINS UNDER A DRY PATTERN. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ UPDATE...KRAMAR

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