Area Forecast Discussion
Issued by NWS State College, PA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KCTP 140725 AFDCTP Area Forecast Discussion National Weather Service State College PA 225 AM EST Sat Jan 14 2017 .SYNOPSIS...
-- Changed Discussion --
An upper air disturbance will link up with a weak trough of surface low pressure nosing in from the Ohio River Valley today to bring periods of light snow to central portions of Pennsylvania and mixed precipitation or freezing rain across the south. Another area of high pressure will build east into the region for Sunday with some sunshine, seasonably cold temperatures and a light northwesterly breeze. Milder conditions will work back into the area for the middle of next week.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 8 AM THIS MORNING/...
-- Changed Discussion --
Regional radar mosaic at 07Z shows the northern edge of a band of light mixed precip over the Ohio Valley into northern W Virginia and Maryland associated with fgen forcing within the entrance region of jet streak over the eastern Grt Lks/NY state. Latest model guidance suggests the northern edge of this precip shield will stay just south of the Mason/Dixon line until around daybreak...when it will begin to nose NE across the Laurel Highlands and adjacent SWRN PA. Til then, 10-15 kts of WNW flow on the eastern side of a flat 850 mb ridge will keep plenty of non-precipitating mid and high clouds across the entire forecast area. Temps through the predawn hours will only fall another 1-3F in most places with lows ranging from the upper teens across the northern tier counties of PA, to the upper 20s in the southern valleys.
-- End Changed Discussion --
&& .SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SUNDAY/...
-- Changed Discussion --
Light snow and mixed precipitation will slowly advance northward into the southern half of Pa during the late morning hours today, as weak wave of low pressure approaches from the Ohio Valley. A host of latest high resolution and ENS guidance indicates a changeover to sleet and freezing rain across my southern tier where advisories are now in effect and will be expanded to include a few more counties on the northern and eastern side. Farther north, very little snowfall is expected north of I80...thanks to cold dry high pressure. The sweet spot for a light accumulation of up to one inch of snow will be in the wedge between the Route 22 and Route 322 corridor from KFIG and KUNV...south to KAOO and east to KMUI and KMDT. The light mixed precip will taper off by Saturday evening across the south. Icing across the southern counties will be quite light and mainly under 0.10 of an inch, but enough to create travel concerns. The Laurels will see the greatest icing problems with an accumulation of glaze between 0.10-0.20 of an inch thick by this evening. Highs today will be within a few degrees of freezing across the south, ranging to the upper 20s north.
-- End Changed Discussion --
&& .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Light mixed precip (or very light snow) may linger for a few hours into the evening hours Saturday across southern portions of our CWA. Little if any additional snow or ice accum is expected though as precip will be light. Partial clearing or better will occur after midnight Sat with just a few flurries possible across the northern and western mtns of the state. High pressure will build into the area from the Upper Great Lakes on Sunday, supplying us with fair, chilly weather and relatively light nwrly wind. High temps will rebound by some 5-8 deg F on Sunday with respect to Saturday`s highs. At the same time, stubborn trough/upper low over the west coast weakens and lifts across the southern plains into the great lakes region as pattern. Ridge over the area tries to hold firm as a warm front lifts through Ohio River Valley early in the upcoming week. This frontal boundary will be preceded and accompanied by a light, wintry mix of precip during the morning hours Monday. A good portion of next week is shaping up to be mild and showery, as bulk of med range guidance shows a ridge slowly retreating off the East Coast as remnants of that west coast low get picked up by the northern stream and track across PA midweek. For Tue into Tue night, deep southerly flow ahead of that trough will bring a plume of anomalous PWATS over the region which supports the idea of showery (rain) and mild weather. As has been the case frequently lately, the GFS brings the trough through faster than the ECMWF. Winds turn westerly behind the system as flow turns more zonal, but with no cold air in sight, temps will remain mild and above freezing. Ridge re-establishes itself over the eastern U.S. for late week, as mild SW flow persists over the midwest. We`ll be on the eastern side of this, so subtle shortwaves sliding into the Midwest will bring varying amounts of cloudiness to the west (less in the east) with low end chances for light showers. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... VFR conditions will continue into the predawn hours beneath thickening mid-high clouds. A wintry mix will spread northeast into the SW 1/4 of the airspace by mid morning reaching JST-AOO by midday and expand north and east impacting UNV/MDT/IPT/LNS through the afternoon. BFD will be on the edge of the wintry pcpn and should stay VFR. Expect MVFR to IFR conditions in the wintry mix zone across the southern 2/3 to 1/2 of the airspace. Low cigs and vsbys could persist late tonight into early Sunday morning as pcpn tapers off and flow remains light. However expect a return to VFR by later Sunday as high pressure slides east from the OH Valley. Outlook... Mon...VFR/No sig wx. Tue...Sub-VFR likely with freezing rain to rain. Wed...Sub-VFR possible with chc of rain/snow showers. && .CTP WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until midnight EST tonight for PAZ033>035. Winter Weather Advisory from 7 AM this morning to midnight EST tonight for PAZ024-025-036-064-065. && $$ SYNOPSIS...Lambert NEAR TERM...Lambert SHORT TERM...Lambert/Fitzgerald LONG TERM...RXR AVIATION...Steinbugl

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.