Area Forecast Discussion
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000
FXUS61 KPBZ 241446
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
946 AM EST MON NOV 24 2014

.SYNOPSIS...
GUSTY WINDS THIS AFTERNOON WILL BE FOLLOWED BY A COLD FRONT AND A
RETURN TO MUCH COLDER CONDITIONS FOR THE REMAINDER OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
COLD FRONT INTO WESTERN OHIO WITH A LINE OF SHOWERS AND AN
ISOLATED THUNDERSTORM. FRONT WILL BE MOVING AWAY FROM BETTER UPPER
LEVEL SUPPORT THIS AFTERNOON WITH LIMITED LOW LEVEL INSTABILITY SO
NO MENTION OF THUNDER FOR NOW. WINDS AHEAD OF AND JUST BEHIND
FRONT STILL EXPECTED TO GUST TOWARD 50 MPH THIS AFTERNOON WITH
MIXING ALLOWING TAPPING OF LOW LEVEL JET OF 50-60KTS AROUND 3-4K
FEET. NOT ALL OF THIS WILL REACH SURFACE AND BEST JET STAYS WEST
TOWARD OHIO...SO CURRENT WIND ADVISORY LOOKS GOOD. BEHIND FRONT
TONIGHT WINDS WILL BE STRONG AND GUSTY INTO THE EVENING WITH MUCH
COOLER AIR WRAPPING IN UNDERNEATH STRONG LOW PRESSURE AS IT MOVES
INTO EASTERN CANADA. ONLY LIMITED CHANGES TO HOURLY TEMPS AND POPS
FROM PREVIOUS FORECAST.


&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
TUES MORNING FLOW REMAINS FROM THE SW...BUT A STOUT INVERSION
PROGGED AT H85 WILL HOLD LLVL MOISTURE IN THROUGH AT LEAST MIDDAY.
THIS WILL KEEP CLOUDS HOLDING STEADY THROUGH THE DAY. H85 TEMPS IN
THE -4C TO -6C RANGE STEEPENS LAPSE RATES IN THE BL ENOUGH TO
GENERATE SOME LIGHT SHOWER ACTIVITY. KEEPING POPS MAINLY ALONG AND
NORTH OF I-80 DURING THIS TIMEFRAME.

BRIEF RESPITE FROM DISTURBED WEATHER TUES EVENING...BUT THE NEXT
SYSTEM ARRIVES WEDS MORNING...WITH THE POTENTIAL TO DISRUPT HOLIDAY
TRAVEL...ESPECIALLY FOR THOSE HEADED EAST. A DEVELOPING COASTAL LOW WILL
TRACK NORTH THROUGH THE MID-ATLANTIC WEDS WITH THE WRN EXTENT OF THE
PRECIPITATION SHIELD REACHING SOMEWHERE BETWEEN THE ERN SLOPES OF
THE APPALACHIANS TO THE OHIO VALLEY. EXACT PLACEMENT AND AMOUNTS OF
PRECIPITATION DEPEND ON THE INTERACTION WITH A CLIPPER-TYPE
SYSTEM MOVING OUT OF THE NRN PLAINS. ATTM MODEL SOLNS STILL VARY
GREATLY WITH THE NAM BRINGING THE PLAINS SHORTWAVE IN
QUICKER...ULTIMATELY PUSHING THE COASTAL LOW EAST OF THE
AREA....HOLDING ALL PRECIPITATION ASSOCIATED WITH IT OUT OF OUR
RIDGES. THE 00Z ECMWF IS ON THE OPPOSITE END OF THE SPECTRUM
ALLOWING THE LOW TO TRACK FURTHER WEST WITH PRECIPITATION SPREADING
WEST TO AT LEAST THE OHIO BORDER. WITH THIS MUCH SPREAD...DECIDED TO
HOLD ONTO THE SREF AS GUIDANCE...WHICH IS A DECENT COMPROMISE. POPS
WERE EXPANDED WESTWARD...HOWEVER...TO SHOW AT LEAST A CHANCE OF
PRECIPITATION GETTING WEST OF THE RIDGES.

COMPLICATING MATTERS FOR THE MID-WEEK SYSTEM WILL BE TEMPS HOVERING
NEAR OR ABOVE FREEZING FOR LOCATIONS RECEIVING PRECIPITATION.
ATTM...OPTED FOR A MAV/MOS BLEND FOR HIGHS WEDS...AND APPLIED A
LIBERAL RAIN/SNOW DELINEATION...GIVEN THE FAIRLY COLD AIR ALOFT AND
A RELATIVELY SHALLOW WARM LAYER NEAR THE SFC. ALL TOLD...THROUGH
EARLY THANKSGIVING MORNING...BETWEEN THE COASTAL LOW AND THE
CLIPPER...HAVE LIGHT SNOW ACCUMULATIONS FOR THE RIDGES AND LITTLE TO
NO SNOW ACCUMULATION ACROSS THE LOWER ELEVATIONS WEST. FOR
REFERENCE...THE GFS...WHICH HOLDS A SIMILAR TRACK TO THE 00Z ECMWF
MODEL MENTIONED ABOVE...GENERATES AROUND 6" IN THE HIGHEST
ELEVATIONS THROUGH WEDS NIGHT.
TAX

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
NORTHWEST FLOW AND REMNANT MOISTURE FROM THE EXITING MID-WEEK SYSTEM
WILL PRODUCE SNOW SHOWERS THANKSGIVING NIGHT...ENHANCED JUST
DOWNWIND OF LAKE ERIE AND IN THE UPSLOPE REGIONS OF OUR SE RIDGES.
THESE SHOWERS SHOULD QUICKLY TAPER OFF EARLY FRI...HOWEVER...AS
SUBSIDENCE OCCURS WITH HIGH PRESSURE MOVING IN FROM THE WEST. THIS
WILL EFFECTIVELY LOWER INVERSION HEIGHTS AND CHOKE OUT THE REMAINING
BL MOISTURE BY LATE FRI MORNING.

FROM THAT POINT THE EXTENDED PERIOD GETS A LITTLE TRICKY AS MODEL
GUIDANCE DIVERGES GREATLY. PRIMARILY STUCK CLOSE TO WPC GUIDANCE
BASED HEAVILY ON THE OPERATIONAL GFS. THIS BRIEFLY HOLDS THE SFC
HIGH OVER THE AREA INTO THE EARLY PART OF THE WEEKEND BEFORE AN
UPPER TROF PROPELS A SFC LOW PRESSURE SYSTEM THROUGH THE NRN GREAT
LAKES. THE ASSOCIATED MOISTURE-STARVED COLD FRONT WILL STREAM ACROSS
THE FORECAST AREA SUN RESULTING IN SOME SHOWERS. RAISED TEMPS AHEAD
OF THE FRONT WHICH MEANS THAT RAIN AND RAIN/SNOW COME INTO
PLAY...BUT ANY QPF ASSOCIATED LOOKS LIGHT.
TAX

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THE AFTERNOON AS A
STRONG COLD FRONT APPROACHES. WHILE VERY LITTLE RAINFALL WILL
ACCOMPANY THE FRONT...THE BIGGER IMPACT WITH BE WIND GUSTS. S-SW
WIND GUSTS APPROACHING OR EXCEEDING 40KTS ARE EXPECTED AT ALL OF THE
SITES THROUGH THE AFTERNOON. COULD NOT RULE OUT SOME
THUNDER...ESPECIALLY AT THE NORTHERN SITES BUT WILL NOT MAKE MENTION
OF THIS WITH LOW CONFIDENCE AT THE MOMENT.

OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
RESTRICTIONS IN SNOW SHOWERS ARE POSSIBLE LATE WEDNESDAY THROUGH
THURSDAY.


OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
POSSIBLE RESTRICTIONS IN SNOW SHOWERS LATE WEDNESDAY THROUGH
THURSDAY.

&&

.CLIMATE...
RECORD HIGH TEMPERATURES ARE POSSIBLE IN THE REGION TODAY. HERE IS
A SUMMARY OF CURRENT FORECAST HIGH TEMPERATURES WITH THE STANDING
RECORDS AND YEARS OF RECORD OCCURRENCE.

CITY                     FORECAST  RECORD/YEAR
PITTSBURGH INTERNATIONAL    71         69/1931
MORGANTOWN                  74         72/1979
ZANESVILLE                  65         70/2001
NEW PHILADELPHIA            65         71/1979
WHEELING                    71         70/2001
DUBOIS                      67         61/1979

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR MDZ001.
OH...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR OHZ039>041-
     048>050-057>059-068-069.
PA...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ007>009-
     013>016-020>023-029-031-073>076.
WV...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR WVZ001>004-012-
     021>023-041.

&&

$$









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