Area Forecast Discussion
Issued by NWS

Current Version | Previous Version | Text Only | 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
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KPBZ 092010 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 310 PM EST TUE FEB 9 2010 .SYNOPSIS...
-- Changed Discussion --
A STRENGTHENING LOW PRESSURE SYSTEM WILL AFFECT THE REGION THROUGH WEDNESDAY...WITH ACCUMULATING SNOWS. GUSTY WINDS WILL ACCOMPANY THIS SYSTEM FOR WEDNESDAY AND WEDNESDAY NIGHT...WITH LAKE EFFECT SNOW SHOWERS EXPECTED WEDNESDAY NIGHT THROUGH THURSDAY.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
TONIGHT...DOUBLE BARRELED LOW WILL CONTINUE TO MOVE TO THE NORTHEAST. THE LOW MOVING INTO THE OHIO VALLEY HAS BEEN THE PRIMARY LOW...BUT THIS SYSTEM IS EXPECTED TO DECAY OVERNIGHT AS A COASTAL LOW FORMING OFF THE SOUTHEASTERN UNITED STATES BECOMES THE DOMINANT LOW. STILL SOME CONCERNS ABOUT WHEN THE HEAVIEST PRECIPITATION WILL FALL. MODEL RUNS HAVE INDICATED THAT THE HEAVIEST PRECIPITATION COULD OCCUR WHEN THE FRONT ASSOCIATED WITH THE INLAND LOW MOVES ACROSS THE AREA...AROUND MIDNIGHT TONIGHT. HOWEVER...OBSERVATIONS LEAN MORE TOWARDS A BAND OF PRECIPITATION MOVING THROUGH RIGHT AROUND RUSH HOUR TONIGHT...WITH DRIER AIR TRYING TO PUSH IN OVERNIGHT. WILL BUMP UP SNOW TOTALS FOR THE EVENING WITH THIS BAND. AM ALSO GOING TO ASSUME FOR NOW THAT THE DRY SLOT WILL FILL IN...AND WILL NOT SIGNIFICANTLY DECREASE SNOW AMOUNTS FROM THE PREVIOUS FORECAST FOR THE LATE NIGHT TIME PERIOD. PRECIPITATION TYPE MAY ALSO BE AN ISSUE ACROSS EAST CENTRAL OHIO AND NORTHERN WEST VIRGINIA...WITH MULTIPLE REPORTS OF FREEZING RAIN ACROSS CENTRAL WV AND A TEMPERATURE UP TO 38 DEGREES AT MORGANTOWN. WHILE PRECIP HAS STARTED AT MORGANTOWN AS A RAIN/SNOW MIX...EXPECT THAT THIS WILL QUICKLY CHANGE OVER TO SNOW. WILL ALSO KEEP THE CHANCE OF FREEZING RAIN IN THE FORECAST DURING THE EVENING HOURS FOR OUR SOUTHERN COUNTIES UNTIL COLDER AIR PUSHES IN BEHIND THE FRONT. EVEN IF NO FROZEN PRECIPITATION FALLS...TEMPERATURES JUST BELOW FREEZING SHOULD HELP TO KEEP SNOW RATIOS SOMEWHAT LOWER ACROSS THE SOUTH. AS THE FRONT MOVES THROUGH AFTER MIDNIGHT...EXPECT WINDS TO VEER TO THE SOUTH AND TO BECOME GUSTY...WITH WINDS UP TO 20-25 MPH. WEDNESDAY...AS THE COASTAL SYSTEM BECOMES DOMINANT OFF THE DELAWARE COAST IN THE MORNING...WRAPAROUND PRECIPITATION WILL CONTINUE ACROSS THE ENTIRE FORECAST AREA...ALTHOUGH AMOUNTS WILL BE LESS THAN THE OVERNIGHT PERIOD. COLDER AIR MOVING IN SHOULD ALLOW FOR SNOW RATIOS TO INCREASE SOMEWHAT...MAKING THE SNOW SOMEWHAT MORE FLUFFY. GUSTY WINDS WILL CONTINUE TO BE A FACTOR...WITH WEST WINDS GUSTING UP TO 30 MPH. WITH THE WINDS PICKING UP...WILL CONTINUE THE MENTION OF BLOWING SNOW IN THE FORECAST.
-- End Changed Discussion --
&& .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
-- Changed Discussion --
WEDNESDAY NIGHT AND THURSDAY...WITH THE SURFACE LOW MOVING OFF THE EASTERN SEABOARD...SYSTEM SNOWFALL WILL END WEDNESDAY EVENING. HOWEVER...NORTHWEST FLOW WILL ALLOW FOR LAKE EFFECT SNOW SHOWERS TO BEGIN. AMOUNT OF LAKE EFFECT MAY BE SOMEWHAT LIMITED WITH SOME VEERING IN THE WIND PROFILE BETWEEN THE SURFACE AND 850MB...ALONG WITH LOW INVERSION HEIGHTS. THIS SHOULD NOT PREVENT THE LAUREL HIGHLANDS FROM GETTING MODERATE SNOW WITH UPSLOPE FLOW. LATER SHIFTS WILL NEED TO EVALUATE WHETHER HEADLINES WILL NEED TO EXTENDED FOR THESE AREAS. WIND GUSTS ARE EXPECTED TO BE THE STRONGEST WEDNESDAY EVENING...WITH A STRONG PRESSURE GRADIENT BETWEEN THE SURFACE LOW OFF THE COAST AND DEVELOPING HIGH PRESSURE IN THE CENTRAL PLAINS. BLOWING SNOW WILL ALSO CONTINUE TO BE MENTIONED FOR WEDNESDAY NIGHT. WARMER AIR BEGINS TO PUSH IN ALOFT ON THURSDAY...ALSO WORKING TO DIMINISH LAKE EFFECT POSSIBILITIES. THURSDAY NIGHT AND FRIDAY...DRIER AIR WILL CONTINUE TO WORK INTO THE AREA. THIS...ALONG WITH WINDS BACKING TO THE WEST...SHOULD RESULT IN THE TAPERING OFF OF SNOW SHOWERS THURSDAY EVENING. HIGH PRESSURE WILL MOVE IN FOR FRIDAY. EVEN WITH HIGH PRESSURE RETURNING...TEMPERATURES WILL STILL REMAIN SOME 10-15 DEGREES BELOW NORMAL.
-- End Changed Discussion --
&& .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
-- Changed Discussion --
COLD NORTHWEST FLOW WILL CONTINUE INTO THE WEEKEND WITH LIGHT SNOW SHOWERS OR FLURRIES AND WELL BELOW NORMAL TEMPERATURES. A FAIRLY STRONG SYSTEM WILL DIG INTO THE WESTERN GREAT LAKES UNDER THE EASTERN CANADA VORTEX BRINGING LIGHT SNOW FOR LATER SUNDAY INTO MONDAY. THIS WILL BE MUCH LIKE A CLIPPER SYSTEM AND WITH LIMITED MOISTURE NOT EXPECTED TO BE A LARGE SNOW MAKER. COLD WITH LEFTOVER SNOW SHOWERS TUESDAY. TEMPERATURES WILL REMAIN WELL BELOW NORMAL.
-- End Changed Discussion --
&& .AVIATION /20Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
SNOW AHEAD OF LOW PRESSURE SYSTEM CONTINUES ITS ADVANCEMENT NORTHEASTWARD THIS AFTERNOON. IFR AND LIFR CONDITIONS ARE ALREADY BEING REPORTED AT MOST TERMINALS. THE EXCEPTION IS LBE WHERE A SLOT OF DRY AIR HAS MOVED THROUGH. BELIEVE IFR CONDITIONS WILL SETTLE IN ALL TERMINALS BY 21-22Z AND REMAIN THE PREVAILING CATEGORY THROUGH THE OVERNIGHT HOURS. QUESTION ON PRECIP TYPE IS STILL A CONCERN FOR NORTHERN WEST VIRGINIA INCLUDING MGW. WITH PKB AND CKB REPORTING FREEZING RAIN AND RAIN RESPECTIVELY CANNOT RULE OUT A CHANGE TO RAIN/RAIN SNOW MIX FOR A PERIOD IN MGW AS TEMPERATURES ARE IN THE UPPER 30S. TOMORROW AS ENERGY IS TRANSFERRED TO COASTAL LOW...SNOW WILL TAPER TO MVFR SHOWERS WITH OCCASIONAL IFR SNOW. NORTHWEST WINDS WILL INCREASE TOMORROW AS COASTAL LOW CONTINUES TO DEEPEN AND ASSOCIATED UPPER LEVEL LOW SLOWLY PROGRESSES EASTWARD. GUSTS TO 25-30KTS ARE POSSIBLE TOMORROW AFTERNOON/EVENING...CAUSING ADDITIONAL RESTRICTIONS IN BLOWING SNOW. AS COASTAL LOW PUSHES OUT TO SEA NW WINDS WILL CONTINUE THE CHANCE FOR LAKE ENHANCED MVFR SNOWS/CLOUD COVER THROUGH FRIDAY MORNING. HIGH PRESSURE BUILDS IN FOR LATE FRIDAY AND SATURDAY ALLOWING FOR MAINLY VFR CONDITIONS. NEXT CHANCE OF RESTRICTIONS WILL BE SUNDAY AS A CLIPPER SYSTEM MOVES THROUGH THE AREA.
-- End Changed Discussion --
&& .PBZ WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
MD...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR MDZ001. OH...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR OHZ039>041- 048>050-057>059-068-069. PA...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR PAZ007>009- 013>016-020>023-029>032. WV...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR WVZ001>004- 012-021>023-041.
-- End Changed Discussion --
&& $$

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