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 081821 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 121 PM EST MON FEB 8 2016 .SYNOPSIS... A COLD FRONT WILL SPREAD RAIN AND SNOW OVER THE REGION TODAY...WITH SNOW TUESDAY AND WEDNESDAY ALONG WITH COLDER TEMPERATURES.. && .NEAR TERM /THROUGH TUESDAY/...
-- Changed Discussion --
QUICK UPDATE TO RAISE TEMPS ACROSS THE EASTERN PORTIONS OF THE CWA. PREVIOUS...AREA OF RAIN AND SNOW AHEAD OF FIRST DIGGING SHORTWAVE ACROSS EASTERN OHIO SLOWLY PROGRESSING EAST AND NORTHEAST. BEST LIFT AND SLIGHTLY BETTER PRECIP RATES HEADING INTO NORTHEAST OHIO THROUGH THE AFTERNOON. BAND OF RAIN WITH SNOW POSSIBLY MIXED AT TIMES WILL SHIFT EAST ACROSS REGION THROUGH THE AFTERNOON. MAY BE A MIX TO PITTSBURGH AT TIMES WITH WET BULBING...BUT PRECIP WILL BE LIGHT FOR THE MOST PART AND WARM LOWER BOUNDARY LAYER LOOKS TO MELT MOST SNOW IF ANY. BRIEF PERIOD OF LIGHT TO MODERATE SNOW ACROSS EASTERN OHIO IS ON THE WANE AS SUPPORT QUICKLY SHIFTS NORTH. MAIN CHANGE TO AFTERNOON FORECAST WAS TO ADD MIX UP TO PITTSBURGH. NO OTHER SIGNIFICANT CHANGES AS TEMPERATURES LOOK IN LINE. PREVIOUS DISCUSSION FOR THE TONIGHT PERIOD FOLLOWS. TONIGHT THE FRONT DOOR TO THE COLD AIR SWINGS OPEN AS THE LOW DIVES INTO THE AREA AND THE UPPER-LEVEL LOW DEEPENS. MODELS HAVE BEEN TRENDING UPWARD IN THE INTENSIFICATION OF THE LOW...AND RESULTANT QPF OVERNIGHT. 00Z NAM OMEGA FIELDS APPEAR TO BE OVERDONE...WITH SEVERAL BULLSEYES OF QPF NEARING 1". STILL...THE BROADER OPERATIONAL MODELS OF THE GFS AND ECMWF SHOW AN UPTICK OF QPF WITH AN AREA OF MID-LEVEL DEFORMATION ALONG THE MASON DIXON LINE. THIS TREND HAS RESULTED IN THE RAISING OF SNOW AMOUNTS OVERNIGHT...AND THE NEED FOR AN EXPANSION BOTH IN TIME AND AREA OF THE WINTER WEATHER ADVISORY. WILL NEED TO MONITOR GUIDANCE CLOSELY TODAY FOR ANY POSSIBLE NORTHWARD EXPANSION...OR WARNING UPGRADES.
-- End Changed Discussion --
&& .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/...
-- Changed Discussion --
TRICKY FORECAST CONTINUES INTO THE SHORT TERM PERIOD. SURFACE LOW CONTINUES TO CHURN TO OUR NORTH OVER THE EASTERN GREAT LAKES TUESDAY. MODELS GENERALLY AGREE ON PLACEMENT OF HIGHER SNOW TOTALS ACROSS THE SOUTHERN PORTION OF THE CWA. A WEAK TROWAL SETUP/FRONTOGENTIC FORCING ARE PRESENT WHICH WILL HELP TO ENHANCE SNOW TOTALS AS COMPARED TO AREAS TO THE NORTH. THERE IS SOME VERY MINOR DISAGREEMENT ON NORTHERN EXTENT OF THIS MORE FAVORABLE FORCING...BUT MODEL AGREEMENT IS RELATIVELY GOOD. CONTINUED SLOW COLD ADVECTION WILL ALLOW CLOUD MICROPHYSICAL CONDITIONS TO IMPROVE WITH TIME...ALONG WITH SNOW RATIOS. THIS COULD LEAD TO LOCALLY HIGHER TUESDAY SNOW TOTALS THAN CURRENTLY DEPICTED DEPENDING ON WHERE BEST DYNAMICS ULTIMATELY SET UP. BEST FORCING BEGINS TO WANE LATER ON TUESDAY AS THE COLDER AIRMASS STARTS TO SETTLE IN. CATEGORICAL POPS WERE PLACED FROM PIT ON SOUTH. TO THE NORTH...LIKELY POPS WERE MAINTAINED...BUT THE LACK OF SIGNIFICANT FORCING...ESPECIALLY AS COMPARED TO THE SOUTH...COULD LEAD TO A SHARPER CUTOFF IN SNOW COVERAGE THAN CURRENTLY DEPICTED. A MORE TYPICAL NW FLOW SNOW PATTERN BEGINS TO SET UP TUESDAY NIGHT INTO WEDNESDAY AS H500 CLOSED LOW IS ABSORBED INTO EASTERN CONUS TROUGH. RESULTING MIDLEVEL TROUGH AXIS ROTATES ACROSS THE CWA ON WEDNESDAY WHICH WILL HELP TO KEEP SHSN GOING. HIGH CHANCE TO LIKELY POPS WERE MAINTAINED FOR THE CWA THROUGH WEDNESDAY. AS FAR AS SNOW TOTALS...CURRENTLY CONSTRUCTED GRIDS DO APPROACH BUT DO NOT MEET/EXCEED WARNING CRITERIA IN ANY GIVEN 12 OR 24 HOUR PERIOD IN THE RIDGES. THIS IS EVEN MORE THE CASE IN LOWER ELEVATION AREAS TO THE WEST. AFTER COLLABORATION WITH OTHER OFFICES...ELECTED TO GO WITH LONG-LASTING ADVISORIES FOR ROUGHLY THE SOUTHERN HALF OF THE CWA...WITH LONGER DURATION IN THE RIDGES. CANNOT RULE OUT THE NEED TO UPGRADE TO A WARNING IF BANDING STRUCTURES CAN FORM AND SIT OVER A PARTICULAR REGION...BUT CONFIDENCE IS TOO LOW TO PLACE SUCH A WARNING AT THIS TIME.
-- End Changed Discussion --
&& .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
-- Changed Discussion --
E COAST UPR TROFG IS PROGGED TO PERSIST THRU SAT. COLD TEMPS AND PERIODIC SNOW SHOWER CHCS ARE EXPD AS SHORTWAVES ROTATE THRU THE TROF...AND SOME LAKE AND TERRAIN ENHANCEMENT OCCURS. RIDGING AND TEMP MODERATION IS EXPD SUN. THE LATEST SUPERBLEND GUIDANCE WAS USED FOR THE LONG TERM FCST.
-- End Changed Discussion --
&& .AVIATION /18Z MONDAY THROUGH SATURDAY/...
-- Changed Discussion --
CONDITION DETERIORATION TO MVFR AND OCNL IFR IS EXPD AS RAIN AND SNOW ACCOMPANY A CROSSING COLD FRONT. MVFR AND SCT SNOW SHOWERS SHOULD PERSIST THRU TUE UNDER COLD UPR TROFG...WITH A PD OF IFR SNOW EXPD FOR PORTS S OF PIT LT TNGT/TUE WITH A MORE ORGANIZED SHORTWAVE. .OUTLOOK.../TUESDAY NIGHT THROUGH SATURDAY/... RESTRICTIONS ARE EXPD THRU SAT UNDER COLD UPR TROFG.
-- End Changed Discussion --
&& .PBZ WATCHES/WARNINGS/ADVISORIES... MD...WINTER WEATHER ADVISORY UNTIL 7 PM EST WEDNESDAY FOR MDZ001. OH...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST WEDNESDAY FOR OHZ049-050-057>059-068-069. PA...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST WEDNESDAY FOR PAZ021-029-031-073-075. WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST WEDNESDAY FOR PAZ074-076. WV...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST WEDNESDAY FOR WVZ001>004-012-021-509. WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST WEDNESDAY FOR WVZ510-511-513. WINTER WEATHER ADVISORY UNTIL 7 PM EST WEDNESDAY FOR WVZ512- 514. && $$

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