Area Forecast Discussion
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000 FXUS61 KPBZ 151052 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 652 AM EDT MON SEP 15 2014 .SYNOPSIS... A CROSSING COLD FRONT IS LIKELY TO BRING SHOWERS TONIGHT FOLLOWED BY MAINLY DRY CONDITIONS AND RELATIVELY COOL TEMPERATURES THE REMAINDER OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... NO UPDATES NEEDED EARLY THIS MORNING AS THE CURRENT FORECAST ALIGNS WELL WITH LATEST OBSERVATIONAL TRENDS. PREV DISCUSSION FOLLOWS.. LATEST OBSERVATIONS INDICATE MINIMAL DEWPOINT DEPRESSIONS ACROSS THE FORECAST AREA...WHICH HAS BEEN THE CASE THE MAJORITY OF THE NIGHT. HOWEVER...FOG FORMATION HAS BEEN WIDELY SCATTERED AND DENSE FOG CRITERIA IS NOT ANTICIPATED THIS MORNING. ANY AREAS OF FOG...ALTHOUGH WIDELY SCATTERED...WILL RESULT IN VISIBILITIES OF LESS THAN A QUARTER OF A MILE... WITH LOWER ELEVATIONS AND LOCATIONS ALONG AREA RIVERS HAVING THE HIGHEST LIKELIHOOD OF THIS OCCURRING. DEWPOINTS REMAINED LARGELY IN THE LOWER TO MID 40S THROUGH THE EVENING AND AS CLOUDS DIMINISHED AND RADIATIONAL COOLING QUICKLY DROPPED SURFACE TEMPERATURES DOWN TO THOSE MARKS. WITH NO SIGNIFICANT MOISTURE ADVECTION UNDER LIGHT BOUNDARY LAYER WINDS ACROSS THE REGION...TEMPERATURE DECREASES OVERNIGHT WERE MUTED DUE TO THE LATENT HEAT RELEASED DURING CONDENSATION AT THE SFC. WITH THAT...THE FROST ADVISORY HAS BEEN CANCELLED AS WIDESPREAD DAMAGING FROST IS NO LONGER EXPECTED. TEMPERATURES WILL BE APPROXIMATELY 5 DEGREES BELOW NORMAL ON AVERAGE TODAY EVEN WITH ABUNDANT SUNSHINE AS HIGH PRESSURE OVERHEAD LIMITS MIXING...AND WILL ALSO BE SLIGHTLY SLOWER TO RISE THROUGH THE MORNING WITH HEAVY OVERNIGHT DEW FORMATION. CLOUD COVERAGE WILL INCREASE THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONT...WITH SHOWERS SPREADING ACROSS THE REGION THIS EVENING. THE COLD FRONT WILL BE THROUGH THE FORECAST AREA SHORTLY AFTER MIDNIGHT WITH SHOWERS CONTINUING BEHIND THE FRONT. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... QUICK MOVING DISTURBANCE EXITING EAST TUES MORNING WITH DRY QUICKLY MOVING IN ALOFT. EXPECTING MOST POP CHANCES TO CEASE BY AFTERNOON AS HIGH PRESSURE BUILDS ACROSS OUR WEST...BUT ENOUGH LOW LEVEL MOISTURE LINGERS IN THE RIDGES TO GENERATE SCATTERED SHOWERS. BY LATE TUES...HIGH PRESSURE WILL TAKE CONTROL AS SKIES CLEAR AND WINDS SLACKEN TO NEAR CALM. HIGH PRESSURE CENTERED OVERTOP EARLY WEDS WILL ENSURE A DRY MIDWEEK...DESPITE ANOTHER WEAK UPPER LEVEL DISTURBANCE STREAMING THROUGH THE ERN GREAT LAKES. TAX && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... DESPITE BROAD UPPER TROF IN PLACE AT THE BEGINNING OF THE EXTENDED PERIOD...A SFC HIGH WILL KEEP POPS OUT OF THE FORECAST THROUGH THE EARLY PART OF NEXT WEEKEND. HIGH PRESSURE SLOWLY OOZES EAST THROUGH SAT WITH A FRONT MOVING IN BY SUN EVENING. STRONG AGREEMENT ACROSS GFS/ECMWF WITH REGARDS TO THE EARLY EVOLUTION AND STRUCTURE OF THE FRONT...BUT GFS IS TRENDING A BIT SLOWER ATTM. WILL CARRY CHC POPS ALONG THE FRONT WITH A GENERAL BLEND FOR TIMING PURPOSES. TAX && .AVIATION /12Z MONDAY THROUGH FRIDAY/... LIFR-MVFR FOG THAT DEVLOPED OVERNIGHT WILL BURN OFF BY MID MORNING...FOLLOWED BY VFR CONDITIONS TODAY. A COLD FRONT WILL RESULT IN MVFR AND PERIODS OF IFR CONDITIONS BY MID EVENING...CONTINUING OVERNIGHT. OUTLOOK...VFR CONDITIONS EXPECTED THE MAJORITY OF THE WEEK FOLLOWING THE PASSAGE OF A COLD FRONT TONIGHT. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$

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