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
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KPBZ 221415 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 1015 AM EDT WED APR 22 2015 .SYNOPSIS... UPPER LEVEL LOW PRESSURE OVER THE GREAT LAKES WILL MAINTAIN COOL AND UNSETTLED WEATHER THROUGH THE WEEK. && .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
REINFORCING COLD FRONT IS BI-SECTING THE FORECAST AREA CURRENTLY FROM SOUTHWEST TO NORTHEAST...WIDESPREAD RAIN SHOWERS ARE SPREAD ALONG IT. AS COLD AIR FILTERS IN BEHIND THE FRONT LATE THIS MORNING...TEMPERATURES HAVE FALLEN INTO THE MID TO UPPER 30S...AND MIXING LIGHT SNOW SHOWERS IN WITH THE RAIN. BEHIND THE FRONT A CLEARLY EVIDENT DRY SLOT IS SEEN ON WATER VAPOR IMAGERY...NOW MOVING THROUGH NORTHWESTERN OHIO. THE MAIN AXIS OF DRY AIR WILL SWING SOUTH THROUGH SOUTHWESTERN OHIO...BUT THE FINGER OF DRIER AIR REACHING INTO THE FORECAST AREA BY MIDDAY WILL AT LEAST RESULT IN BREAKING UP THE CLOUD DECK ALLOWING SOME SUNSHINE TO REACH THE SURFACE. A SECONDARY WAVE PASSING NORTH OF LAKE ERIE THIS AFTERNOON WILL PROVIDE ADDITIONAL SUPPORT TO THE CONVECTIVELY DRIVEN SHOWER ACTIVITY THIS AFTERNOON. MUCH COLDER AIR ALOFT WILL ERODE THE LOW- TO MID-LEVEL INVERSIONS AND STEEPEN LAPSE RATES...CONVECTIVE RAIN SHOWERS LOOK MOST PROBABLE ALONG THE NORTH...BUT MOST OF THE FORECAST AREA SHOULD SEE ADDITIONAL RAIN CHANCES THIS AFTERNOON/EVENING. FREEZING LEVEL IS ONLY ABOUT 3-4KFT THIS AFTERNOON SO ADDITIONAL GRAUPEL OR SMALL HAIL WOULD BE POSSIBLE WITH ANY RAIN SHOWERS. DEEPENING THE MIXED LAYER WILL ALSO SUPPORT ANOTHER WINDY DAY...ALTHOUGH NOT TO THE MAGNITUDE OF TUESDAY GIVEN THE REDUCED SPEED ALOFT. DESPITE THE UPPER SUPPORT SHIFTING OUT OF THE AREA BY TONIGHT...THE BOUNDARY LAYER WILL STILL REMAIN DEEP AND MIXED...ESPECIALLY ALONG THE NORTH AND IN THE RIDGES. WITH LAKE- DERIVED LOW-LEVEL MOISTURE FEEDING SHOWERS INTO THE OVERNIGHT...AND TEMPERATURES DROPPING...RAIN SHOULD SUFFICIENTLY TRANSITION TO SNOW. ANY ACCUMULATIONS THROUGH THURSDAY MORNING ARE EXPECTED TO BE LIGHT AND CONFINED TO GRASSY OR ELEVATED SURFACES. TAX
-- End Changed Discussion --
&& .SHORT TERM /THURSDAY THROUGH SATURDAY/...
-- Changed Discussion --
COLD TEMPERATURES CAN BE EXPECTED INTO THE WEEKEND WITH MORNING LOWS ON THURSDAY AND FRIDAY NEAR...OR A FEW DEGREES UNDER THE FREEZING MARK. BY SATURDAY...LOW PRESSURE MOVING OFF THE PLAINS IS PROGGED TO INITIATE WARM ADVECTION...AND POSSIBLY SOME RAIN OVER THE REGION. THE FORECAST FOR SATURDAY IS A LOW CONFIDENCE WORK BASED ON A BLEND OF DIVERGENT GFS AND NAM SOLUTIONS WITH THE ECMWF CONTRIBUTING A SLOWER SCENARIO. IN GENERAL...WARMER SATURDAY MORNING LOWS AND MORE RAPID PRECIP PROBABILITY ONSET WERE FORECAST...ALBEIT WITH ONLY SLIGHT TO CHANCE NUMBERS. CHANGES SHOULD BE ANTICIPATED.
-- End Changed Discussion --
&& .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... LOW PRESSURE WILL CONTINUE TO MOVE EAST ACROSS THE SOUTHEASTERN UNITED STATES...WITH ANY REMAINING RAIN ENDING SATURDAY NIGHT. HIGH PRESSURE WILL SHIFT SOUTHEAST OVER THE GREAT LAKES SUNDAY INTO MONDAY. THIS WILL BRING NORTHWESTERLY WINDS THAT WILL CONTINUE TO KEEP TEMPERATURES BELOW NORMAL. AS HAS BEEN THE TREND THE LAST FEW DAYS...MODELS HAVE LITTLE AGREEMENT ABOUT THE PATTERN FOR THE FINAL TWO DAYS OF THE FORECAST. HAVE TRENDED TOWARDS WPC NUMBERS WHICH KEEP AT LEAST SOME CHANCE OF PRECIPITATION IN THE FORECAST. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
RAIN OCCASIONALLY MIXING WITH SNOW IS RESULTING IN MVFR/IFR CIELINGS ALONG THE COLD FRONT. THESE SHOULD CONTINUE TO PUSH EAST TOWARDS MIDDAY...FINALLY EXITING IN THE EARLY AFTERNOON. BEHIND THE FRONT...ANOTHER ROUND OF GUSTY WINDS IS EXPECTED...ALTHOUGH NOT AS STRONG AS ON TUESDAY. 25-30 KT GUSTS ARE FORECAST AT ALL SITES THROUGH THE AFTERNOON HOURS WITH GUSTS ENDING AT SUNSET. BROKEN MID LEVEL CLOUDS WILL TRAIL THE COLD FRONT AND SHOULD CONTINUE THROUGH THE OVERNIGHT HOURS. .OUTLOOK.../THURSDAY THROUGH SUNDAY/... PERIODIC RESTRICTIONS ARE POSSIBLE MUCH OF THE PERIOD MAINLY NORTH OF KPIT AS AN UPPER TROUGH PERSISTS OVER THE GREAT LAKES. THE BEST CHANCE FOR ANY SHOWERS WILL BE ON SATURDAY FROM PITTSBURGH SOUTH.
-- End Changed Discussion --
&& .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.