Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 242236 AFDCTP Area Forecast Discussion National Weather Service State College PA 636 PM EDT Sat Oct 24 2020 .SYNOPSIS... A cold front will stall south of the Commonwealth tonight. On Sunday, an area of low pressure track northward along the front, bringing light rain to parts of the state. The low will slowly lift across western Pennsylvania by early Monday, keeping unsettled conditions in place through early in the week. A trailing cold front will likely slice through Pennsylvania Monday night or early Tuesday with some midweek drying possible. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Stratus did open up over the central mountains thru the daytime, but the clearing seems to have halted and may even be reversing. This has big implications for our min temps. High clouds are already streaming in from the wave rolling thru the Carolinas. This is the system which will nudge some precip up toward our southern border late tonight. Minimal PoPs should be OK for the overnight, with most mdl solutions dry until right at sunrise. Watching the QPF from many models through the last 48 hours, it has been a very wild ride. Currently, the 18Z NAM has gone back to making very little precip and just in the far SE/lower Susq. The GFS has been most-consistent with timing and QPF, but has waggled a little east and west, north and south, too. No need to change the PoPs right now, but a look at the 00Z NAM and 21Z SREF could help - or just make it muddier. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... Frontal system and low pressure wave will bring periods of light rain and drizzle to much of central and southern PA on Sunday. With sfc low moving off of the mid Atlantic coast, combination of this system and high pressure over New England will produce a chily easterly flow off the W Atlantic. Atlantic moisture will overrun cool/stable air over PA, producing widespread light rain and drizzle overspreading southern PA Sunday morning and the rest of the region during the afternoon. Have continued to undercut NBM high temperatures Sunday, especially over the south, due to its warm bias in cold air damming scenarios. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... The main issue will be the fast southwest flow aloft to start the week off. Expect some rain Sunday night into early Monday, mainly across the southeast early. Another area of rain to the northwest will likely be in part seperate and more toward later Monday. Tried to adjust POPS some. Minor changes to the temperatures. For Tuesday, left some showers in the forecast with the frontal system, but hard to see a lot from this. Most likely day to be dry will be Wednesday. More rain for Thursday. Took the snow showers out across the far northwest late, as trend is for the main westerlies to be much further north, EC run earlier, and now both the EC and GFS to some extent; and the flow from cutoff more likely to keep some moisture and milder temperatures in the area early on. Not real cold aloft to start, so type of precipitation would likely not be snow anyway, but some other type if low level temperatures were able to get real cold. I raised the temperatures a few degrees near the NY border. Either way, the push of cold air will work in during the day on Friday into Saturday, as a large high builds toward PA. Dry conditions expected. This will be short lived, as the main westerlies lift well to the north. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... MVFR cigs improving to VFR most airfields at mid afternoon. Lower clouds may hang on a bit longer at KBFD/KJST, owing to upslope conditions and lake enhancement, within a low- level NW flow regime. Gusty NW winds will decrease this evening. Reductions should be minimal overnight tonight into Sunday morning with a much cooler and drier airmass in place. Outlook... Sun...VFR. Sun night-Tue...Restrictions likely in lower clouds and and periodic light rain. Wed...Mostly VFR. Thu...More wet weather expected with MVFR and IFR conditions possible. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...DeVoir/Fitzgerald NEAR TERM...Dangelo SHORT TERM...DeVoir/Fitzgerald LONG TERM...Martin AVIATION...DeVoir/Martin/Banghoff is the U.S. government's official web portal to all federal, state and local government web resources and services.