Area Forecast Discussion
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000
FXUS61 KPBZ 281804
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
104 PM EST FRI NOV 28 2014

.SYNOPSIS...
A WARM FRONT CROSSES TONIGHT BRINGING SNOW SHOWERS ALONG AND NORTH
OF INTERSTAE 80. A WARMUP IS IN STORE THIS WEEKEND AS WINDS
ORIGINATE FROM THE SOUTH ALLOWING DAYTIME HIGHS TO CLIMB INTO THE
40S SATURDAY AND 50S SUNDAY. THERE WILL BE AN ABUNDANCE OF CLOUDS
AND POSSIBILITY OF LIGHT RAIN SATURDAY NIGHT INTO SUNDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
SURFACE RIDGE AXIS ABOUT TO SHIFT WINDS WEST SOUTHWEST AREA WIDE BY
MID AFTERNOON.  THIS WILL SHUT OFF THE SNOW MACHINE IN THE MOUNTAINS
OF WESTERN MD AND NORTHERN WV.  THERE WILL BE LITTLE BREAK IN THE
ACTIVE WEATHER REGIME WITH FAST MID LEVEL WINDS STEERING SYSTEMS
THROUGH AT LESS THAN 12 HOUR INTERVALS.  WARM FRONT RACES SE
CLIPPING NORTHERN REACHES OF CWA OVERNIGHT.  INCREASED CONSENSUS
AMONGST 12Z NCEP CHAIN HAS YIELDED AN INCREASED IN POPS TO LKLY FOR
I-80 REGION.  THERE WILL BE A SHARP CUTOFF AS LOCATIONS ALONG AND
SOUTH OF I-76 SHOULD REMAIN PRECIP FREE.  ATMOSPHERE THERMAL PROFILE
ILLUSTRATES ALL SNOW WITH THE ENTIRE COLUMN BELOW 0C.  BEST CHANCE
FOR MEASURABLE QPF WILL BE AROUND MIDNIGHT.  ANY SNOW ACCUMULATION
SHOULD BE AROUND AN INCH OR LESS.  AS AREA GETS IN WARM SECTOR
DURING THE PREDAWN HOURS...FORECAST A NON DIURNAL TEMPERATURE
TREND...AS WINDS WILL PICK UP WHILE ANY INVERSION IS SCOURED OUT
EVEN IN THE DEEPEST VALLEYS DUE TO BL FLOW OF 15KTS.

BROAD SOUTHERLY LOW IN THE LOWER LEVELS OF THE ATMOSPHERE PUMP
MOISTURE FROM THE SOUTH...THUS DESPITE BEING IN THE WARM SECTOR
OVERCAST OR NEAR OVERCAST SKY COVER IS PREDICTED FOR
SATURDAY...ESPECIALLY IN THE AFTERNOON.  ANY PCPN ARRIVES FIRST
IN EASTERN OHIO BY AFTERNOON.  BUFKIT SOUNDINGS DO NOT SHOW ANY
THREAT OF MIXED PRECIPITATION FROM WAA ALOFT...SO LIGHT RAIN IS
FORECAST.

TEMPERATURES WERE CONSTRUCTED INITIALLY FROM THE GRIDDED LAMP
TONIGHT THEN A BLEND OF THE EXISTING FORECAST AND ADJ MET BIAS
CORRECTED GRIDS SATURDAY.


&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
WEATHER DOES NOT CHANGE MUCH SATURDAY NIGHT COMPARED TO DURING
THE DAY AS BROAD LOW LEVEL SOUTHERLY FLOW CONTINUES TO BACK BUILD
ALL THE WAY TO THE LOWER MISSISSIPPI RIVER VALLEY. CROSS SECTIONS
OF POTENTIAL TEMPERATURE INDICATES UPGLIDE / POSITIVE PRESSURE
ADVECTION FROM THE SURFACE TO 775MB. SPECIFIC HUMIDITY ARE
SURPRISINGLY MODEST FOR THIS EVENT WITH VALUES REACHING 6GKG-1
SATURDAY NIGHT AT 290K. QPF VALUES WILL NOT BE THAT GREAT GIVEN
LACK OF ANY SYNOPTIC SCALE WEATHER FEATURE. AMOUNTS WILL RUN ON
THE ORDER OF FIVE HUNDREDTHS OR LESS...WHICH WARRANTS LIGHT RAIN
ATTRIBUTE IN WEATHER GRIDS. INCREASED POPS TO LKLY FOR EASTERN
OHIO AND NORTHWEST PA WHILE MAINTAINING CHANCE POPS ELSEWHERE.

A WEAK COLD FRONT WILL MOVE THROUGH THE UPPER MIDWEST ON SUNDAY.
DEEP MOISTURE WILL REMAIN LOCKED OVER THE AREA...SO A SCATTERED
SHOWER IS POSSIBLE AT ANY TIME ON SUNDAY.

ABOVE NORMAL TEMPERATURES SUNDAY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
SHOWER CHANCES INCREASE SUNDAY NIGHT AS THE COLD FRONT TAKES ITS
TIME CROSSING THE REGION. THERE IS REALLY NOTHING TO PUSH THE
FRONT ALONG AS THE UPPER LEVEL SUPPORT IS WEAK AND THE FLOW IN THE
HIGHER LEVELS OF THE ATMOSPHERE IS OUT OF THE SOUTHWEST. FRONT
WILL FINALLY CLEAR THE ENTIRE REGION ON MONDAY MORNING BRINGING AN
END TO THE SHOWERS. EXPECT A BRIEF COOL DOWN MONDAY AND
TUESDAY...WITH SHOWERS AND WARMER AIR RETURNING BY MIDWEEK.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
SNOW SHOWERS ARE QUICKLY ENDING ACROSS MOST OF THE TAF SITES THIS
MORNING. MVFR CIGS WILL LIFT TO VFR WITHIN THE NEXT COUPLE OF
HOURS EVERYWHERE AS A SURFACE RIDGE BUILDS OVERHEAD. NW WIND WILL
BACK TO THE W-SW THIS AFTERNOON AND REMAIN UNDER 10KTS.

OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
RESTRICTIONS WILL BE POSSIBLE FRIDAY NIGHT AT FKL/DUJ WITH A
SYSTEM MOVING NORTH OF THE REGION. THE NEXT CHANCE FOR WIDESPREAD
RESTRICTIONS WILL BE SUNDAY WITH THE PASSAGE OF A COLD FRONT.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$

SYNOPSIS...98
NEAR TERM...98
SHORT TERM...98/10
AVIATION...34



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