Area Forecast Discussion
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000
FXUS61 KPBZ 091440
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
940 AM EST TUE FEB 9 2016

.SYNOPSIS...
MUCH COLDER WITH SNOW SHOWERS THROUGH WEDNESDAY AS SLOW MOVING LOW
PRESSURE MOVES EAST.

&&

.NEAR TERM /THROUGH TONIGHT/...
BAND OF BETTER SNOW TRANSITIONING NORTH AND EAST ACROSS SOUTHWEST
PA AND NORTHERN WV AS CLOSED LOW AND DEFORMATION ZONE MOVE EAST.
SNOWFALL AMOUNTS LOOK TO BE ON TRACK FOR THE MOST PART WITH AREAS
UNDER THE BETTER REFLECTIVITY ON RADAR RECEIVING MODERATE SNOW AT
TIMES THIS MORNING. ADJUSTED HOURLY TEMPERATURES WILL WILL BE
STEADY OR FALLING THROUGH THE DAY.

SNOW WILL BEGIN TO DIMINISH LATE AFTERNOON/EARLY EVENING AS THE
LIFT WEAKENS AND DEPARTS WITH THE CLOSED LOW. SNOW SHOWERS TONIGHT
WILL BE MOST NUMEROUS RIDGE COUNTIES AS THE FLOW TURNS TO THE
NORTHWEST AND THE DENDRITIC GROWTH ZONE DESCENDS UNDER COLD AIR
ADVECTION. LOWS WILL DROP TO NEAR NORMAL TONIGHT.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
H500 TROUGH AXIS SHIFTS EAST EARLY ON WEDNESDAY AS CLOSED LOW OPENS
UP.  NEXT SHORTWAVE WILL ARRIVE DURING THE DAY WITH AN INCREASE IN
COLD ADVECTION.  INVERSION HEIGHTS DROP A BIT AS COMPARED TO TODAY
AND OVERALL MOISTURE LEVEL IS LOWER...BUT ENOUGH MOISTURE IS
PRESENT IN DENDRITIC GROWTH ZONE TO PROMOTE ADDITIONAL SNOW
ACCUMULATION OF AN INCH OR TWO...ESPECIALLY IN THE RIDGES.

COLD ADVECTION SLOWS WEDNESDAY NIGHT AND MOISTURE BECOMES MORE
SHALLOW WITH TIME...WHICH WILL SLOW ACCUMULATION A BIT. ANOTHER
INCH OR SO IS POSSIBLE IN THE HIGHER ELEVATIONS...LESS TO THE
WEST. H850 THERMAL TROUGH ARRIVES AND CROSSES ON THURSDAY...WHICH
WILL HELP TO DIMINISH COVERAGE THROUGH THE DAY. ONLY A FEW SHSN
ARE EXPECTED TO LINGER ALONG THE RIDGES AND NORTH OF I-80 BY
EVENING...WITH A DRY WINDOW EXPECTED AREAWIDE OVERNIGHT.

TEMPERATURES WILL CONTINUE TO DROP FURTHER BELOW NORMAL THROUGH
THIS PERIOD.  ONLY MINOR CHANGES WERE MADE HERE.


&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
ANOTHER SHORTWAVE IS EXPECTED ARRIVE ON FRIDAY WITH SCATTERED SNOW
SHOWERS...LASTING INTO SATURDAY.  KEPT POPS IN THE CHANCE RANGE FOR
NOW. THE MAIN STORY HERE WILL BE THE POSSIBLE ARRIVAL OF THE COLDEST
AIR OF THE SEASON THUS FAR. H850 TEMPS ARE PROGGED TO FALL TO -25C
OR EVEN A BIT COLDER BY 00Z SUNDAY.  BELOW ZERO MIN TEMPS ARE A GOOD
POSSIBILITY SATURDAY NIGHT...PARTICULARLY IF SKIES CLEAR AND WINDS
DECOUPLE.

A DRY AND COLD SUNDAY IS EXPECTED AS THE ARCTIC HIGH PRESSURE
CROSSES. THIS WILL BE FOLLOWED BY MODERATING TEMPERATURES ON
MONDAY AS THE EASTERN U.S. TROUGH LOOSENS ITS GRIP...BUT
PRECIPITATION CHANCES WILL RETURN AS WELL WITH THE NEXT SHORTWAVE
TROUGH. THE SUPERBLEND GUIDANCE WAS USED AS A BASIS FOR MUCH OF
THE LONG TERM FORECAST.


&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
CONDITIONS CONTINUE TO DETERIORATE THIS MORNING AS SPATIAL
COVERAGE OF LIGHT TO MODERATE SNOW EXPANDS. SO FAR THIS MORNING IT
APPEARS THAT VISIBILITIES LESS THAN A MILE ARE MORE A RESULT OF
FOG THAN A RESULT OF HEAVIER SNOW SHOWERS. EXPECTING AT LEAST
MVFR/IFR RESTRICTIONS THROUGH THE DAY AS SNOW LIFTS NORTHWARD
UNDER THE UPPER-LEVEL LOW PRESSURE CENTER. GREATEST IMPACTS SHOULD
BE TO THE SOUTHERN TERMINALS OF LBE/MGW/AGC WITH SNOW LASTING INTO
THE EVENING. GUIDANCE HINTING AT GRADUAL IMPROVEMENT LATE TONIGHT
INTO EARLY WEDNESDAY AS THE AXIS OF THE LOW BEGINS TO SHIFT EAST.
STILL...LIGHT SNOW SHOWERS WILL CONTINUE THROUGH WEDNESDAY...SO
RESTRICTIONS ARE STILL TO BE EXPECTED. LIGHT SURFACE FLOW WILL
GRADUALLY SHIFT TO THE WEST AND INCREASE THROUGH TONIGHT. TAX

.OUTLOOK.../WEDNESDAY THROUGH SATURDAY/...
RESTRICTIONS ARE EXPECTED THROUGH SATURDAY UNDER COLD UPPER-
LEVEL TROUGHING.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 7 PM EST WEDNESDAY FOR MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR OHZ049-
     050-057>059-068-069.
PA...WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR PAZ021-
     029-031-073-075.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST WEDNESDAY FOR PAZ074-
     076.
WV...WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR
     WVZ001>004-012-021-509.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST WEDNESDAY FOR
     WVZ510>514.

&&

$$


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