Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 191040 AFDCTP Area Forecast Discussion National Weather Service State College PA 640 AM EDT Thu Oct 19 2017 .SYNOPSIS... High pressure will remain over the eastern conus through the upcoming weekend. Low pressure is likely to track west of the state early next week with a trailing cold front coming through Pennsylvania Tuesday or early Wednesday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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High pressure is providing the region with another cool and tranquil morning. GOES16 nighttime microphysics channel is showing some patchy valley fog at 1030Z, mainly in the deep river valleys north of I-80. Any fog should burn off by around 14Z based on latest NAM guidance. Abundant sunshine should then push readings to near 70F by this afternoon. A shortwave tracking well north of Pa will push a dying cold front into our region late today. Models indicate just enough moisture preceding this front to produce sct late day cu across the northwest mountains. However, lack of significant forcing or deep moisture support POPs near zero.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... A slight increase in low level moisture and an active breeze in vicinity of dying front should result in milder conditions tonight in general across central Pa. However, a weaker gradient and drier air behind front should allow for better radiational cooling and patchy fog across the northwest mountains Friday morning. Min temps are expected to range from around 40F over the northwest mountains, to the upper 40s across the southeast part of the forecast area. Anomalous upper ridge will expand northeast from the Ohio Valley on Friday. Large scale subsidence with this feature should result in another sunny day. Ensemble mean 925mb temps of around 14C should translate to max temps in the upper 60s and low 70s. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... Both the 00Z ECENS and NAEFS maintain an anomalous upper level ridge over the area through the weekend, which should ensure fair weather with above average temperatures Sat-Sun. Ensemble mean 925/850 temps support highs of 70-75F, while light wind and dry air result in seasonably cool nights. All medium range guidance indicating there will be a digging northern stream trough early next week over the upper midwest and Miss Valley that will eventually phase with closed low lifting out of the southern states. Considerable model difference exist with respect to timing/track of this southern stream shortwave, resulting in arrival of showers as early as Monday or as late as Tues PM. For now, have slowly ramped up the chance of rain beginning late Monday. However, will reserve the best chance of rain for Tuesday/Tues night, when bulk of med range guidance track shortwave and attendant plume of Gulf of Mexico moisture across the area. Early QPF estimates from operational runs and GEFS indicate 1+ inch amounts are possible. A period of near to below normal temperatures appears likely for the second half of next week, as upper trough swings east into the area. However, both GFS and ECMWF ensemble systems indicate the thrust of the chilly air will be directed west of Pa and there are indications of rising heights/milder weather across the entire eastern conus toward the end of the month. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... GOES-16 fog channel is starting to show valley fog formation across portions of the central and eastern airspace. Surface obs indicate eastern TAF sites have decoupled with temp/dewpt spreads tightening to within a few degrees. Therefore expect greatest odds for restrictions at KIPT, KLNS and KMDT in that order. Fog should dissipate by 14z giving way to VFR. To the west in ZOB sector, expect VFR to prevail through the period. Wind gusts will reach the 15-20kt range over the western 1/2 of the airspace from late this morning through the afternoon. A dry cold front will push across the airspace this evening and early tonight accompanied by a light wind shift from 220-250 to 270-330 degrees. High pressure moves back over PA late tonight into Friday morning. Outlook... Fri-Sun...Patchy AM valley fog otherwise VFR. Mon...VFR to MVFR. Showers possible into Monday night. LLWS likely Monday night into early Tuesday. && .CLIMATE... Month-to-date, October 2017 is the warmest October on record at Harrisburg and Williamsport. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Fitzgerald NEAR TERM...Fitzgerald SHORT TERM...Fitzgerald LONG TERM...Fitzgerald/Ceru AVIATION...Steinbugl CLIMATE... is the U.S. government's official web portal to all federal, state and local government web resources and services.