Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 241552 AFDCTP Area Forecast Discussion National Weather Service State College PA 1152 AM EDT Wed May 24 2017 .SYNOPSIS... Periods of wet weather with cooler-than-average temperatures will dampen the area for the second half of the week. Widespread rain is expected late tonight into Thursday, followed by shower spells Thursday afternoon into Friday. Temperatures should rebound modestly over the Memorial Day holiday weekend with a chance for showers and thunderstorms. && .NEAR TERM /THROUGH TONIGHT/...
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Nice clearing this morning will give way to a low cloud deck in the southwest and a steadily spreading/thickening high cloud shield elsewhere this afternoon. The NE counties will probably stay mo sunny/clear very late in the day. Timing of rain over western PA is pretty solid with all the newest guidance still on track with going fcsts. But, the new guidance does slow the eastward progression by a few hours. Will nudge fcst that way for the next 12 hrs. It should be spotty light stuff in the west first, but increase in intensity through the evening. Have added a deg or two to the maxes with the nice sunshine over most of the area right now. Prev... 10Z: Light rain is exiting the LSV pushing east into NJ. The latest near term HIRES model and ensemble guidance still keeps most of the area dry today as pcpn activity focuses to the south/west across the OH Valley and Central Appalachians. Max 12hr POPs ending 25/00z are over the southwest 1/4 of the CWA or in the Laurel Highlands late this afternoon/early evening. Models remain consistent in bringing widespread rain over the area tonight into early Thursday morning and have increased POPs to near 100 percent for the entire CWA. Strong H85 moisture flux anomalies and southeast low level jet combined with increasing large scale forcing/ascent associated with amplifying upper trough suggests some moderate to locally heavy rain amounts (0.75 to 1 inch) are possible tonight with peak rain intensity likely in the 06-12z Thursday period. The southeast low level flow should enhance UVVS in the eastern upslope side of the terrain where some local 1" pcpn maxes will be possible.
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&& .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... The strong upper trough will pivot over the northern Mid Atlantic states on Thursday, with low pressure at the surface consolidating over PA Thursday night before lifting up the NJ/New England coast Friday. Steadier rain Thursday morning should lift north of the area with partial sunshine leading to shower spells and perhaps a few T`storms in the afternoon. Broad cyclonic/northwest flow with additional shortwaves rotating around the departing upper low will keep showers in the fcst on Friday before precip winds down Friday night/AM Saturday. && .LONG TERM /SATURDAY THROUGH TUESDAY/... A lower-amplitude mid level flow pattern in the wake of the departing closed upper low will feature rising heights/weak ridging aloft into the weekend. The pattern will evolve into a broadly cyclonic flow regime by early next week with upper low spinning between the Great Lakes and Hudson Bay into midweek. There is still some uncertainty regarding the location and timing of shortwave impulses that could be a factor for convection on Saturday. Model and ensemble guidance still favoring locations to the south/west of Central PA so a dry start to the holiday weekend may be in store for the area. 24/00z NBM/ECE/WPC blend maintained the highest POPs on Sunday with another round of showers/storms possible for Memorial Day. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... Steady rain now east of our area. Adjusted 12Z TAFS. Earlier discussion below. Some showers across the southeast this morning. CIGS still VFR across the southeast, but 4-5SM with the showers. Few drops of rain near BFD. CIG at JST low now. Expect conditions to improve by mid to late morning. Overall it should be a dry day with VFR conditions. Next system will result in more rain. Rain will overspread the area this evening from the west. Poor conditions will linger at least Thursday, if not early Friday. .OUTLOOK... Thu...Rain/low cigs likely through at least midday. Fri...Showers/MVFR cigs NW. Mainly VFR SE. Sat...No sig wx expected. Sun...Reduced conditions with scattered showers. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Steinbugl NEAR TERM...Dangelo/Steinbugl SHORT TERM...Steinbugl LONG TERM...Steinbugl AVIATION...Martin is the U.S. government's official web portal to all federal, state and local government web resources and services.