Area Forecast Discussion
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000 FXUS61 KPBZ 240547 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 1247 AM EST SAT JAN 24 2015 .SYNOPSIS... LOW PRESSURE WILL BRING SNOW SOUTH OF INTERSTATE 80 TONIGHT INTO EARLY SATURDAY. WIDESPREAD SNOW IS EXPECTED WITH SUNDAY AND MONDAY LOW PRESSURE. && .NEAR TERM /THROUGH TODAY/... A SHRTWV ADVNG ACRS THE OH AND TN VLY RGNS WL CONT TO BRING SNW S OF A DUJ TO ZZV LN INTO ERLY SAT. THE SFC LOW IS ACRS THE CAROLINAS WITH AN INVERTED TROF INTO SWRN PA. PRES FALLS ARE INCRG ALG THE COAST...SIGNALLING THE DVLPMNT OF A COASTAL LOW OCCURRING. THIS SHOULD HELP CONT THE DCRG TREND IN THE SNW INTENSITY...THOUGH ONE MORE MODERATE BAND WL LIKELY MOVE NEWD ACRS THE RIDGES OVRNGT. CONTD ADVY/WRNG AS IS. THE SHRTWV SHOULD EXIT SAT MRNG WITH MOST OF THE SNW ENDING. TEMPS WERE NUDGED TO THE LATEST LAMP NMBRS. && .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... SHORTWAVE TROUGH WILL DEEPEN AS IT DROPS SOUTH OVER THE UPPER MIDWEST SATURDAY NIGHT AND SUNDAY AS THE ASSOCIATED UPPER LEVEL JET CORE HELPS AMPLIFY THE OVERALL LONGWAVE PATTERN. LATEST GUIDANCE INDICATES THE WAVE CLOSING OFF IN THE LOWER LEVELS BY SUNDAY EVENING WITH H925 AND H850 BECOMING EASTERLY AROUND 25-30KTS ON AVERAGE. ATTM UPPER LEVEL DYNAMICS LOOK FAVORABLE FOR A 6-12 HR PERIOD OF MORE INTENSE SNOW DEVELOPING BY MID SUNDAY EVENING WITH PRESSURE ADVECTION AT PV15 OVERLAYING AREAS OF FRONTOGENESIS AT LOWER LEVELS. OVERALL MODELS ARE IN RELATIVELY GOOD AGREEMENT WITH PROGGED SNOW AMOUNTS WITH ABOUT 4 INCHES ON AVERAGE...WITH HIGHER TOTALS ACROSS SOUTHERN ZONES. THE PROBLEM IS THAT PLACEMENT HAS BEEN INCONSISTENT AND OVER THE PAST 24 HOURS MODELS HAVE TRENDED FARTHER SOUTH/DEEPER WITH THE FEATURE. LATEST FORECAST REFLECTS A BLEND OF THE LATEST GUIDANCE WITH A SLIGHT ADJUSTMENT TO THE SOUTH ANTICIPATING MODELS CONTINUE THE OBSERVED TREND. WITH THAT...HAVE OPTED TO HOLD OFF ON ANY HEADLINES FOR NOW...BUT SHOULD HAVE BETTER CONFIDENCE IN DETAILS OVER THE NEXT 24 HOURS OR SO. IN ANY CASE...ADVISORY LEVEL SNOWFALL LOOKS LIKELY FOR A LARGE PART OF THE FORECAST AREA. && .LONG TERM /TUESDAY THROUGH FRIDAY/... THE LONG TERM FORECAST WL FEATURE MODERATING TEMPS AFTR A COLD FIRST HALF OF THE WEEK AS THE ERN CONUS TROF FILLS. SFC HIGH UNDR FLAT SHRTWV RIDGING SHOULD SUPPRESS PCPN UNTIL THE APCH OF LATE WEEK LOW PRES. LITTLE DEVIATION FM WPC GUIDANCE WAS NEEDED. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
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GENERAL IFR ACROSS THE SOUTHERN PORTS IN LIGHT SNOW AND CIGS WITH MIXED PRECIP AT KMGW...WHICH SHOULD CHANGE TO SNOW BY 09Z. AS ENERGY TRANSITIONS TO COASTAL LOW EXPECT SNOW TO TAPER NEXT 2-3 HOURS BUT IFR CIGS WILL REMAIN UNTIL IMPROVEMENT AFTER 12Z. NORTHERN PORTS LOOK TO DETERIORATE TO LOW MVFR OR IFR FOR A TIME BEFORE DAYBREAK WITH STRATUS IN COLD ADVECTION. OVERALL IMPROVEMENT TO MVFR ALL PORTS EXPECTED THIS AFTERNOON. .OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/... CROSSING LOW PRES IS LIKELY TO SPAWN RESTRICTIONS OVR ALL TERMINALS ON SUNDAY AND MONDAY...WITH RESTRICTIONS POSSIBLE TUESDAY.
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&& .PBZ WATCHES/WARNINGS/ADVISORIES... MD...WINTER STORM WARNING UNTIL 10 AM EST THIS MORNING FOR MDZ001. OH...NONE. PA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ074-076. WV...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR WVZ023. WINTER STORM WARNING UNTIL 10 AM EST THIS MORNING FOR WVZ041. && $$

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