Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 020748 AFDCTP Area Forecast Discussion National Weather Service State College PA 248 AM EST Fri Dec 2 2016 .SYNOPSIS... A large and deep storm system will move slowly through Quebec over the next couple of days keeping a prolonged period of cool northwest flow over the local area. High pressure will build in for a brief time Sunday before the next frontal system approached early next week. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... No big changes late this evening as lake effect regime continues tonight. Lake clouds and flurries hugging areas along and north of the PA/NY border this evening are showing a slight southward drift. Latest HRRR in good agreement with this trend for the overnight...as backing flow upstream flow evidence in northeast Ohio should bring this to fruition. Expect an increase in snow shower activity after midnight across the north. Boundary layer and sfc marginally cold and bands not expected to become very organized. However...a light accumulation will be seen over my northern tier overnight. Some sprinkles still mixed in in areas where lighter precip rates occur. Mins will be fairly uniform throughout...ranging from the lower 30s northwest to the lower to middle 30s elsewhere. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/... The cold NW flow will remain air in place for Friday, but again the cold air is unimpressive so NW snow shower activity is not expected to amount to more than nuisance amounts. With high temps expected to be above freezing, most areas will ave a hard time making any snow stick at all. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... As low continues to move further east into the Canadian Maritimes, lake effect snow showers over the NW mtns will gradually wind down on Sat. But one last shortwave Fri night could be enough to extend snow bands into parts of the central mtns for a time. Sunday brings a brief respite as high pressure moves over the state. By late Sunday into the overnight, a period of light snow is possible as a northern stream shortwave races through the region with a burst of warm advection. QPF looks to be on the order of a tenth of an inch or less, but occurring overnight many places could see their first coating of snow of the young season by Mon morning. Another ridge moves through on Monday as progressive weather pattern becomes more active. On Tues there is decent agreement in bringing the SW US upper low up through the OHIO Valley as a shearing out shortwave and diffuse surface low. Unless cold air damming traps enough chilly air in the low levels to make for some freezing rain, the precip type with this midwest system looks to be mainly rain. The end of the week brings some model disagreement with the GFS/GEFS being faster than the ECMWF with the next large upper trof and frontal system. Either way, precip looks like a good bet around the Thu/fri period as all solutions eventually bring this trough through. So predictability is increasing, but timing issues remain. Best bet for precip at this point is mainly rain over the SE as decent push of warm air lifts ahead of the system, with a rain/snow mix further north where warm air will not infiltrate as much. Behind the trough, looks like a chilly weekend in store with a potential sharp dropoff in temps. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/...
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Early AM satellite loop shows stratocu covering most of Central Pa associated with slow moving low pressure over Southern Quebec. 07Z radar is showing lake effect snow showers affecting Northwest Pa, where KBFD is experiencing IFR conditions. Latest GLMP MELD supports predominantly IFR conditions at KBFD for the balance of the morning. Elsewhere, model soundings indicate falling CIGs this morning, as a slight wind shift from WSW to WNW causes moisture from the Great Lakes to spread south. GLMP MELD suggests IFR CIGs and snow showers are possible later this morning at KJST. Downsloping flow east of the mountains should result in progressively better conditions further east, with tempo MVFR possible at KAOO/KUNV and VFR at KIPT/KMDT/KLNS. Weak diurnal heating/mixing should result in a modest increase in CIGS by this afternoon, likely resulting in CIGS between 1-2KFT at KBFD/KJST and VFR elsewhere. However, passing snow showers will still occasionally drop vsbys below 3SM at KBFD/KJST through evening. The entire region will continue to see breezy conditions last through the next 24 hours. Clearing skies have resulted in lighter winds at KMDT/KLNS early this morning. However, Bukfit soundings support winds between 10-20kts across the entire region later today and evening, with occasional gusts near 25kts. Outlook... Sat...SHSN with ocnl IFR vsby at KBFD/KJST, mainly in the morning. Sun...Light snow/reduced vis possible at night, mainly NW Mtns. Mon...No sig wx expected. Tue...Mixed precip/low CIGs possible.
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&& .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Gartner NEAR TERM...DeVoir/Gartner SHORT TERM...La Corte/Gartner LONG TERM...La Corte/RXR AVIATION...Fitzgerald

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