Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 240753 AFDCTP Area Forecast Discussion National Weather Service State College PA 353 AM EDT Fri Mar 24 2017 .SYNOPSIS... A warm front will drift northeast from the Ohio River Valley today, and we could see a brief period of freezing rain this morning followed by a rapid warm up. The frontal boundary will sag back south to near the Mason-Dixon line by Saturday night, then remain stationary from near the Baltimore/Washington area Sunday night. Mid-tropospheric heights and temperatures over the Commonwealth will be slightly above normal into next week. A few week systems should bring showers to the region, but at this time the pattern does not suggest any significant rain events. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... High clouds overspreading the SE half of the state, while thicker/layer clouds capable of supporting some rain were edging east across the PA/OHIO border. Under mainly clear skies early on, temperatures dipped into the mid and upper 20s. The mercury is beginning to rebound back above freezing in many locations as a light wind develops and stirs up the near-sfc layer. However, with the sfc T/Td spread on the order of 10-20 deg F, expect significant boundary layer cooling and a fairly good chance at seeing some very light freezing rain (and even some sleet pellents) through about 14-15Z today. Satellite imagery shows a larger area of deep cold cloud tops over Michigan and leading cirrus over Ohio. Clouds are coming and behind them some rainfall is coming. Due to the cold air in the boundary layer the rain will likely start as freezing rain over northern and some central areas. Farther south less QPF is forecast and later in time so less likely they will see freezing rain. The HRRR and its coarser twin the RAP show the precipitation coming in slower with each run. Likely, most areas will not see any precipitation before 6 AM. In with 0.01 to about 0.10 inches of QPF a light glaze is possible before 9 AM (especially in northern and central areas). Most of the region in the advisory for freezing rain could see a light glaze this morning. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... There will be a lingering threat for isolated freezing rain in the 8 AM to 10 AM timeframe today in some locations and perhaps 11 AM in colder areas of our northeastern areas. But the forecast rapid warm up and the March sun angles should help reduce this fast. One might not see the sun but the shortwave energy will reach roads and walks. The chance of rain diminishes during the day. There should be a very rapid warm up by late morning and into the afternoon. Winter will have exited stage East and it may be along time before we see any significantly cold weather again. High temperatures should range mainly from the 50 to the lower 60s. Warmest in the south/southwest. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... At the outset of the longer term period the models are in fair agreement in timing and strength. All are indicating a boundary just to the north of Pennsylvania with a large upper level low moving through the central midwest. A negatively tilted ridge over the mid Atlantic will allow for stable but cloudy weather into Saturday. Lows Friday night into Saturday should range from the upper 40s to low 50s. There could be light rain showers on Saturday but warm and stable. A cooler moist boundary should move into the region Sunday out ahead of the approaching low. Have adjusted POPs for timing and intensity. QPF remains variable but possible wet period Sunday into Monday. Above average temperatures are expected over the weekend with the warmest day likely on Saturday with some sites approaching 70F over southern PA. Sunday should be markedly cooler behind a backdoor cold front and a likelihood of rain. However, above average temperatures (especially nighttime) appear very likely through early next week, as 12Z GEFS indicates Pa remains beneath a mean upper level ridge and plume of anomalous PWATs. The chance of showers will spike with passage of next shortwave Tuesday into Wednesday. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... VFR conditions under thickening high-mid level clouds will trend lower with MVFR most likely between 09-15z as quick shot of light precip moves across the airspace. Thermal profiles remain marginally supportive of brief/light ice mix (FZRAPL) across the northeast 2/3 of the airspace before changing to rain. A strong low level jet from 230-260 degrees will produce LLWS thru mid morning. The precip exits the airspace to the east by 18z leaving behind mainly dry VFR/MVFR conditions through tonight. Guidance is less optimistic at KBFD suggesting a more prolonged period of IFR conditions. Outlook... Sat...Mainly VFR. Chance of rain northern 1/2 airspace. Sun-Tue...Sub-VFR with periods of rain. && .CTP WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 11 AM EDT this morning for PAZ005-006-010>012-017>019-026>028-037-041-042-045-046-049>053- 056>059. && $$ SYNOPSIS...Grumm/Lambert NEAR TERM...Grumm/Lambert SHORT TERM...Grumm/Lambert LONG TERM...Fitzgerald/Ceru AVIATION...Steinbugl is the U.S. government's official web portal to all federal, state and local government web resources and services.