Area Forecast Discussion
Issued by NWS

Current Version | Previous Version | Graphics & Text | 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
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KPBZ 231029 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 629 AM EDT WED JUL 23 2014 .SYNOPSIS... A COLD FRONT WILL BRING SHOWERS AND STORMS TO THE AREA TODAY AND THROUGH THE EVENING HOURS. COOLER AND DRIER AIR FOR THE REST OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A COLD FRONT WILL RUSH THROUGH THE REGION TODAY. FRONT WILL RECEIVE AND NICE PUSH FROM A STRENGTHENING SHORTWAVE TROUGH WHICH WILL SWING IN BEHIND THE SURFACE BOUNDARY THIS AFTERNOON. MOST OF THE SHOWER AND STORM ACTIVITY WILL BE RIGHT ALONG THE FRONT AND BEHIND IN THE VICINITY OF THE TROUGH. ATMOSPHERE WILL QUICKLY DESTABILIZE AS THE FRONT MOVES THROUGH. BECAUSE OF THE TIMING OF FRONTAL PASSAGE...THE SOUTHERN HALF OF THE AREA WILL EXPERIENCE HIGHER INSTABILITY LEVELS WITH SURFACE BASED CAPE OF 1500 TO 2000 J/KG AND A LIFTED INDEX CLOSE TO -4. WOULD THINK THAT IF ANY STRONGER ACTIVITY DEVELOPS...IT WOULD BE OVER THE SOUTH. SHEAR VALUES ARE NOT IMPRESSIVE ONLY AROUND 20 TO 25KTS...AND WITH FRONT CLEARING THE ENTIRE AREA BY 20Z...IT WILL NOT CROSS AT THE MOST OPTIMAL TIME. EVEN THOUGH THE FRONT WILL PASS IN THE EARLY PART OF THE AFTERNOON...WILL NEED TO KEEP IN POPS BEHIND THE FRONT WITH THE PASSAGE OF THE STRONG SHORTWAVE. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... IT WILL TAKE MOST OF THE EVENING FOR THE SHORTWAVE TO EXIT THE FAR SOUTH. THIS WILL NECESSITATE LEAVING IN POPS ACROSS THE SOUTHERN HALF THROUGH THE EVENING. ATMOSPHERE WILL BE STABILIZING SO EXPECT THE THUNDERSTORM THREAT TO DIMINISH IN THE EVENING. ANOTHER UPPER LEVEL DISTURBANCE WILL CROSS ON THURSDAY...BY THIS TIME MOST OF THE MOISTURE WILL CONFINED TO LOCATIONS NEAR THE MASON-DIXON LINE. WILL LEAVE IN THE MENTION OF SHOWERS THERE UNTIL THE TROUGH PASSES LATE THURSDAY AFTERNOON. COOLER AND DRIER AIR FOR THE ENTIRE REGION FRIDAY WITH SURFACE HIGH MOVING IN AND THE UPPER LEVEL FLOW BECOMING MORE ZONAL. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... LOW CONFIDENCE FORECAST FOR THE BEGINNING OF THE LONG TERM PERIOD. MODELS EXPLORING SOME DIFFERENT OPTIONS WITH A SHORTWAVE TROUGH THAT WILL CROSS THE AREA SOMETIME ON SATURDAY. THIS PART OF THE FORECAST WILL NEED TO BE REFINED ONCE MODEL RUN TO RUN BECOMES MORE CONSISTENT. THE NEXT SYSTEM WILL BRING SHOWERS AND STORMS TO THE AREA SUNDAY AND MONDAY AND MUCH COOLER AIR FOR THE END OF THE LONG TERM. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... SCATTERED SHOWERS AND ISOLATED THUNDER HAS DEVELOPED WELL AHEAD OF MAIN FRONT AND HAVE ADDED A SHORT PERIOD OF VCSH WITH THUNDER AT AGC. OTHERWISE BY LATE MORNING APPROACHING COLD FRONT INTO WESTERN TIP OF LAKE ERIE AT 10Z WILL BRING SCATTERED SHOWERS AND STORMS FROM NORTHWEST TO SOUTHEAST ACROSS THE REGION. FOR NOW MVFR IN SHOWERS WITH VCNTY THUNDER STILL LOOKS GOOD AND WILL NEED TO BE REFINED IN LATER TERMINALS BASED ON REDEVELOPMENT AS MAIN LINE IS QUICKLY WEAKENING THIS MORNING. WEST TO SOUTHWEST WINDS NEAR 10KT AHEAD OF THE FRONT AND SHIFT TO WEST NORTHWEST NEAR 10KTS WITH FROPA LATE AFTERNOON. OUTLOOK.../WEDNESDAY THROUGH SUNDAY/... GENERAL VFR THURSDAY INTO SATURDAY AS HIGH PRESSURE RETURNS TO THE AREA. RESTRICTIONS POSSIBLE LATER SATURDAY AND SUNDAY AS LOW PRESSURE APPROACHES. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$

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