Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 191327 AFDCTP Area Forecast Discussion National Weather Service State College PA 827 AM EST Mon Feb 19 2018 .SYNOPSIS... An anomalous upper level ridge will remain parked off the southeast coast through the upcoming week. At the surface, a warm front will approach Pennsylvania from the southwest today, then push north of the area Tuesday. A dying cold front will push southeast across the area late Wednesday, then stall in the vicinity of Pennsylvania late this week into the weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... No change in the overall thinking of a warm front approaching the region. Increasing warm advection/isentropic lift will support an area of rain sliding across, mainly favoring the northern 2/3 or so of my CWA. The leading edge of the steady rain is moving into my NWRN zones and the HRRR shows this to continue marching east while increasing on coverage throughout the day. The rest from earlier... Model guidance continues to support a good chance of rain today, as warm front lifts into western Pa, while wedge of cooler air remains trapped east of the Appalachians. Highest POPS of near 100 pct are painted across northern Pa, where the best isentropic lift is indicated at nose of low level jet coming through late morning into the afternoon. Can`t completely rule out a rumble of thunder across northern Pa, where a bit of elevated instability is noted in the models. HREFV2 and HRRR indicate the rain will be most widespread during early afternoon, with the back edge of the steady rain lifting north with the baroclinic zone and best isentropic lift late in the day. Max temps are likely to range from the 50s on the warm side of the front west of the Alleghenies, to the 40s east of the mountains. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... All models indicating surface warm front becomes hung up along the spine of the Appalachians tonight. However, isentropic lift associated with low level jet and 850 baroclinic zone will shift north of the state, causing rain to lift north of the NY border this evening. Light wind and a moist boundary layer north of surface warm front is likely to result in areas of fog across the eastern half of the state tonight into Tuesday morning. Model surface theta-E fields indicate the warm front will lift north of the entire area Tuesday, flooding the area with near record warmth. Even conservatively mixing to just 925mb should yield max temps of around 70F over the southern part of the forecast area, with slightly lower maxes across the northern mountains and Middle Susq Valley. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... All med range guidance tracks a cold front through the region Wed PM, accompanied by late day showers. Ahead of the front, ensemble mean 925mb temps of near 16C should translate to another day of near record highs, ranging from the low to mid 70s over much of the region east of the Alleghenies. 00Z ECENS and GEFS both indicate cold front will stall out just south of Pa Thursday, then oscillate in the vicinity of Pa into next weekend. Thus, have included chance to likely POPs through next weekend. Med range models do indicate there could be just enough low level cold air for the potential of some fzra Thu night or early Friday across northern Pa. Otherwise, ptype appears to be all rain with broad southwest flow over the east coast keeping temps well above normal. && .AVIATION /13Z MONDAY THROUGH FRIDAY/... A warm front will approach Pennsylvania from the southwest today, then push north of the area Tuesday. Central PA will see an extended period of LLWS with SW flow at 850mb hanging around 40-50 kts. VFR conditions at 12z will give way to restrictions spreading quickly across the region from the SW through mid/late morning. Rain sliding in from the west will bring further reductions to IFR as it impacts the west starting late morning and eastern areas in the afternoon. The light rain will come to an end this afternoon, with conditions improving from the SW, where JST/AOO look to jump back to VFR by this evening. But eastern sections look to remain in the soupy air with lingering IFR conditions in low clouds/drizzle through tonight. Outlook... Tue...Restrictions early east. Scattered rain showers and restrictions NW mtns. Tue night...Ceiling restrictions again likely eastern sections. Wed...Restrictions likely in rain showers mainly NW half. Thu-Fri...Intermittent restrictions in rain showers (light wintry mix north). && .HYDROLOGY... Unlike the event last Thursday evening...the flow is less west...east with the next system. Strong upper level ridging should push the warm front to the north faster. Thus QPF should be rather light across the area prior to 18Z Wed. Heaviest QPF prior to this time will be likely across northwestern Warren County Monday evening...with perhaps isolated amts in the .50 to .75 inch range. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Fitzgerald/La Corte NEAR TERM...Fitzgerald/La Corte SHORT TERM...Fitzgerald LONG TERM...Fitzgerald AVIATION...RXR/La Corte HYDROLOGY...

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