635
FXUS61 KPBZ 201156
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
656 AM EST THU FEB 20 2020
SYNOPSIS
OUTSIDE OF ISOLATED FLURRIES TODAY, HIGH PRESSURE WILL MAINTAIN DRY
CONDITIONS, WITH MODERATING TEMPERATURE THROUGH THE WEEKEND.
NEAR TERM /THROUGH TONIGHT/
MORNING UPDATE: NO MAJOR CHANGES HAVE BEEN MADE IN THIS FORECAST
PERIOD.
PREVIOUS DISCUSSION: DRY WEATHER, AS DEFINED BY NON- MEASURABLE
PRECIPITATION, IS EXPECTED TO CONTINUE TODAY DESPITE THE ENCROACHMENT
OF AN UPPER TROUGH/ASSOCIATED REINFORCING COLD FRONT. MODEL WORLD
CONTINUES TO DISPUTE THE EVENTUAL MOISTURE SUPPLY AVAILABLE FOR
PRECIPITATION OVER THE REGION WITH GFS REMAINING THE MORE AGGRESSIVE.
EITHER WAY, SUFFICIENT LOW LEVEL LAPSE RATES INTO A SHALLOW
DENDRITIC GROWTH, WITH FRONTAL LIFT AND FORCING FOR ASCENT VIA THE
UPPER TROUGH, ALBEIT WEAK, ARE ENOUGH TO MAINTAIN A SLIGHT CHANCE OF
SOME LIGHT SNOW/FLURRIES.
EARLY TIMING OF THE REINFORCING COLD FRONT SHOULD HOLD HIGH
TEMPERATURE ABOUT 10 DEGREES UNDER THE AVERAGES.
SHORT TERM /FRIDAY THROUGH SUNDAY/
BROAD HIGH PRESSURE WILL MAINTAIN DRY WEATHER THROUGH SUNDAY WITH
GRADUAL TEMPERATURE MODERATION. NO REAL CHANGE WAS MADE TO THE
WEEKEND FORECAST.
LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/
PRECIPITATION CHANCE IS FORECAST TO INCREASE AGAIN BY MONDAY AS
SOUTHERN STREAM LOW PRESSURE EMERGES FROM THE PLAINS AND DIGS UP THE
OHIO VALLEY AS IT WEAKENS. WITH COLDER AIR LOCKED NORTHWARD VIA THE
NORTHERN STREAM OF THE JET, AND WITH WARM ADVECTION ON THE VAN OF THE
LOW, PRECIPITATION WITH THAT EVENT SHOULD PRIMARILY BE RAIN.
MODELS AGREE THAT AN AMPLIFYING, AND ENCROACHING UPPER TROUGH IS
LIKELY TO CONTINUE PRECIPITATION CHANCES INTO MIDWEEK AND THEN BRING
COLDER WEATHER TO THE REGION.
AVIATION /12Z THURSDAY THROUGH MONDAY/
MARGINAL MVFR CIGS ARE POSSIBLE ACROSS FKL/DUJ LATER THIS MORNING
AND EARLY AFTERNOON WITH A CROSSING SHORTWAVE. OTHERWISE, VFR IS
EXPECTED THROUGH THE PERIOD WITH HIGH PRESSURE. ISOLATED FLURRIES
ARE ALSO POSSIBLE TODAY WITH THE SHORTWAVE, BUT SHOULD REMAIN LIGHT
ENOUGH SUCH THAT CONDITIONS REMAIN VFR.
OUTLOOK
RESTRICTIONS WILL BE POSSIBLE LATE SUNDAY WITH THE APPROACH OF LOW
PRESSURE.
PBZ WATCHES/WARNINGS/ADVISORIES
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
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