Area Forecast Discussion
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FXUS61 KPBZ 061521
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1021 AM EST SAT FEB 6 2016

.SYNOPSIS...
WARM TEMPERATURES ARE EXPECTED THROUGH THE WEEKEND. LOW PRESSURE
WILL SPREAD RAIN AND SNOW OVER THE REGION ON MONDAY AND TUESDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
WARM ADVECTION AND INSOLATION IN ADVANCE OF A DRY SHORTWAVE TROUGH
WILL DRIVE TEMPERATURES ABOUT 7 DEGREES ABOVE THE AVERAGES TODAY.

THAT TROUGH WILL CROSS THE AREA TONIGHT. MOISTURE AND ASCENT WITH
THAT FEATURE WILL BE LACKING...SO NO PRECIP IS ANTICIPATED AND
THE DISTURBANCE IS TOO WEAK TO PULL COLDER AIR OVR THE
REGION...HENCE OVRNGT LOWS WILL NOT BE FAR OFF THE AVERAGES.

RIDGING BETWEEN UPR MS VALLEY AND SERN U.S. LOW PRESSURE SYSTEMS
WILL SUPPORT A DRY SUNDAY WITH FURTHER...ALBEIT MINOR...MODERATION
OF TEMPERATURE.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
THE UPR MS LOW IS CURRENTLY FORECAST TO DEEPEN OVR THE GREAT LAKES
AND MIDWEST...HENCE AMPLIFYING THE SOUTHWEST...TO SOUTHERLY FLOW
OVR THE UPR OH FOR SUNDAY NIGHT AND MONDAY. IMPROVED MOISTURE AND
ASCENT FIELDS WILL THUS SUPPORT INCREASED PRECIP PROBS OVER
WESTERN ZONES ON SUNDAY NIGHT WITH EASTWARD ENHANCEMENT ON
MONDAY.

THE MARGINAL TEMP PROFILE AND WARM BOUNDARY LAYER IN THE WARM
ADVECTION REGIME ON THE EASTERN FLANK OF THAT SYSTEM SHOULD
COMPROMISE SNOW POTENTIAL AND PRECLUDE SERIOUS ACCUMULATION THROUGH
MONDAY...HOWEVER...THE SYSTEMS FRONTAL PASSAGE WILL DECISIVELY
CHANGE THE TEMP PROFILE AS NIGHT FALLS ACCORDING TO CURRENT
TIMING.

FORTUNATELY...THE ENCROACHMENT OF THE MID/UPR LOW CENTER SHOULD
SUFFICIENTLY WEAKEN THE WIND AND OVRALL ASCENT FIELDS AND THUS
COMPROMISE THE IMPROVED TEMP PROFILE FOR SNOW. THE FORECAST IS
THUS OF PROLONGED SNOW SHOWER POTENTIAL THROUGH TUESDAY WITH
RELATIVELY MINOR ACCUMULATION. THE EXCEPTION LOOKS TO BE THE
RIDGES AS USUAL WHERE OROGRAPHIC SUPPORT SHOULD SUPPORT MORE
SIGNIFICANT ACCUMULATION.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THE AFOREMENTIONED LOW IS GFS/ECMWF FORECAST TO CUTOFF AND
DEVELOP EASTWARD BEFORE FILLING/PHASING INTO THE LONGWAVE PATTERN
BY MIDWEEK. NEVERTHELESS...OVERALL UPPER TROUGHING IS PROGGED OVR
THE GREAT LAKES/UPR OHIO REGION FOR THE LONG-TERM PERIOD...WITH
AMPLIFICATION INDICATED TOWARD THE WEEKEND. SUB-AVG TEMPS AND
PERSISTENT SNOW SHOWER CHANCES WERE MAINTAINED FOR THE PERIOD...WITH
FOCUS TOWARD THE I-80 CORRIDOR AND RIDGES DURING THE LATTER HALF
OF THE WEEK.

THE LONG TERM WAS CONSTRUCTED USING THE SUPERBLEND GUIDANCE.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS ARE EXPD THRU SUN...THOUGH A WEAK GT LKS SHORTWAVE
WILL BRING OCNL MID LVL CLOUDS TODAY.

.OUTLOOK.../SUNDAY NIGHT THROUGH WEDNESDAY/...
RESTRICTIONS ARE EXPD WITH A SUN NGT/MON COLD FRONT AND SUBSEQUENT
UPR TROFG THRU MID WEEK.

&&

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

&&

$$
15/07


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