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 310130 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 930 PM EDT MON MAR 30 2015 .SYNOPSIS... LOW PRESSURE WILL TRACK ACROSS THE REGION LATER TONIGHT INTO TUESDAY AND BRING ANOTHER ROUND OF PRECIPITATION. A WARMING TREND WILL ARRIVE FOR THE MIDDLE OF THE WEEK. && .NEAR TERM /THROUGH TUESDAY/...
-- Changed Discussion --
TEMPERATURES REMAIN MILD THIS EVENING WITH WESTERLY LOW LEVEL FLOW AND WEAK WARM ADVECTION AT 850MB. FAST MOVING CLIPPER TYPE SYSTEM OVER THE WESTERN GREAT LAKES THIS EVENING WILL RACE SOUTHEAST OVERNIGHT AND CROSS THE REGION TUESDAY. ADJUSTED TEMPERATURES MAINLY AHEAD OF SYSTEM TONIGHT TO REMAIN STEADY UNTIL PRECIP ARRIVES BEFORE DAYBREAK. WITH DEW POINTS IN THE 20S EXPECT WET BULBING TO DROP TEMPERATURES QUICKLY...ESPECIALLY ACROSS THE NORTH. 18Z MODEL RUNS CONTINUE TO SHOW SURFACE LOW MOVING SOUTHEAST ACROSS THE HEART OF THE REGION WITH RAIN AND SNOW NORTH OF THE THE I-80 CORRIDOR AND PLAIN RAIN ELSEWHERE LATE TONIGHT INTO THE FIRST HALF OF TUESDAY. STILL REMAINS TO BE SEEN HOW MUCH SNOW WILL BE ABLE TO ACCUMULATE ACROSS THE FAR NORTH AS NEWER RUNS JUST A BIT WARMER WITH CRITICAL THICKNESS. COMBINED WITH FAIRLY WARM GROUND...PREVIOUS SNOW AMOUNTS STILL SEEM A REASONABLE COMPROMISE WITH 1-2 INCHES FOR FOREST COUNTY AND AN INCH OR SO ELSEWHERE NORTH OF I-80...WITH A COATING POSSIBLE JUST SOUTH OF THIS. PLAIN RAIN ELSEWHERE...WITH ALL PRECIP TRANSITIONING TO SHOWERS IN THE AFTERNOON AS SURFACE LOW CROSSES THE RIDGES AND COLD ADVECTION SWEEPS SOUTH. HIGH TEMPERATURES WILL BE REACHED IN THE MORNING TUESDAY WITH A WIDE RANGE FROM THE MID 50S KZZV TO NEAR 40 NORTH OF I-80..THEN BEGIN A SLOW FALL IN THE AFTERNOON AS NORTH WINDS BEHIND EXITING SURFACE LOW INCREASE. TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR GUSTS TO 30 MPH WITH HIGHER GUSTS POSSIBLE IN THE RIDGES.
-- End Changed Discussion --
&& .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... PRECIPITATION SHOULD END RATHER ABRUPTLY TUESDAY NIGHT...SAVE FOR THE HIGHER TERRAIN...AS THE LOW PRESSURE MOVES WELL OFF TO THE EAST AND NW FLOW ENSUES. THE BACK EDGE OF THE UPPER TROUGH AND SOME MID LEVEL MOISTURE SHOULD MAINTAIN SOME CLOUD COVER THROUGH MUCH OF THE NIGHT BEFORE HIGH PRESSURE RIDGE BUILDS EASTWARD AND DRIES OUT THE LOW-MID LEVELS. DESPITE MOSTLY SUNNY SKIES BY MIDDAY WEDNESDAY...NW FLOW SHOULD KEEP TEMPERATURES CLOSE TO OR JUST BELOW SEASONAL AVERAGES. A RETURN OF SOUTHWEST FLOW IS EXPECTED AHEAD OF THE NEXT COLD FRONT FORECAST TO MAKE IT`S APPROACH THURSDAY NIGHT. WHILE WE MAY DECOUPLE WEDNESDAY NIGHT...ALLOWING FOR TEMPERATURES TO FALL BACK INTO THE 30`S...HIGH TEMPERATURES THURSDAY ARE EXPECTED TO BE WELL INTO THE 60`S AND APPROACHING 70 FOR POINTS FROM PITTSBURGH ON SOUTH. THIS IS IN PART DUE TO STRONG WARM ADVECTION ALOFT WITH 850HPA TEMPERATURES APPROACHING +10C. IN ADDITION TO THE WARMING TEMPERATURES...A 50KT LOW LEVEL JET MAY PROVIDE FOR SOME GUSTY WINDS OUT AHEAD OF AND ALONG THE SLOW MOVING COLD FRONT. HOWEVER...THE INTRICATE DETAILS OF THE FORECAST ON THURSDAY WILL BE DETERMINED LATER AS THERE IS STILL A BIT OF UNCERTAINTY IN THE FRONTAL TIMING BETWEEN THE THREE DETERMINISTIC MODELS AND THE ENSEMBLES. THIS TIMING WOULD IMPACT THE DEVELOPMENT OF ANY SHOWERS AND STORMS AHEAD OF THE FRONT...AND SUBSEQUENT ISSUES WITH WIND. THUS...HAVE OPTED TO STAY RELATIVELY CLOSE TO THE PREVIOUS FORECAST BUT WANTED TO KEEP VERY LOW POPS UNTIL LATE THURSDAY AFTERNOON. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... DECENT PRECIPITATION CHANCES WILL CONTINUE INTO THE WEEKEND AS THE FRONT SAGS ACROSS THE REGION AND PROVIDES FOCUS FOR SUBSEQUENT LOW PRESSURE PASSAGE LATER ON FRIDAY...WITH AN EASTWARD EXIT ON SATURDAY. THIS FORECAST WAS BASED ON A BLEND OF GFS TRENDS AND WPC GUIDANCE WITH SHORTWAVE TIMING AND BOUNDARY PLACEMENT LIKELY TO REMAIN QUESTIONABLE FOR A FEW DAYS. THE THURSDAY WARMTH WILL THUS BE SHORT LIVED...BUT THE COOL DOWN WILL NOT BE AS DRAMATIC AS THIS PAST WEEKEND GIVEN THE ZONAL FLOW THAT IS PROGGED ALOFT. TWEAKED WPC GUIDANCE WAS USED FOR THE SEASONABLY COOL TEMP FORECAST. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... VFR CONDITIONS WILL CONTINUE UNTIL THE NEXT SYSTEM SPREADS RAIN AND SNOW ACROSS THE AREA LATE TONIGHT. LIFR/IFR CONDITIONS ARE LIKELY IN SNOW AT KFKL AND KDUJ AS SNOW RATES INCREASE AS DAWN ARRIVES...WITH VERY GUSTY WINDS LIKELY EVERYWHERE SOUTH OF KBVI AS THE WARM SECTOR AND RAIN SHOWERS ADVANCE NORTHWARD. .OUTLOOK.../TUESDAY THROUGH SATURDAY/... RESTRICTIONS ARE LIKELY WITH CROSSING LOW PRESSURE ON TUESDAY AND AGAIN LATE THURSDAY AND FRIDAY. && .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.