260 FXUS61 KCTP 110242 AFDCTP Area Forecast Discussion National Weather Service State College PA 1042 PM EDT Wed Oct 10 2018 .SYNOPSIS... After one more muggy night, a cold front will move through the area Thursday and could produce some locally heavy rain. The rainfall remnants of Hurricane Michael should track mainly south of Pennsylvania. Cooler and drier conditions will arrive for Friday and the upcoming weekend. A prolonged period of below normal temperatures is then in store. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Plume of anomalously high PWAT air (nearly +4 sigma) will slide east across the CWA through the midday hours Friday (Through late afternoon/evening over the far SE zones). Waves of light to moderate showers (over mainly Central and Western PA overnight) will solidify across the eastern half of the CWA by daybreak then drift gradually to the east during the day as a cold front slowly approaches from the Ohio Valley and Lower Great Lakes. Made some upward adjustments to pops and minor changes to QPF tonight and Thursday. Rainfall will average from around 0.50 of an inch across the far NW zones, to around 1.25 inches in a SW-NW 50-70 NM wide swath from the Laurels, across the Central Mtns to communities throughout the West Branch and North Branch Valleys of the Susquehanna. The aforementioned cold front is progged to push into far wrn PA shortly after sunrise Thursday, then slowly its eastern progress as the much weakened Tropical Storm Michael moves across East-Central NC. Again, the precip forecast the NW looks relatively light, generally just up to around 0.50 of an inch. However, thunder is possible across the rest of the area, mainly along a pre- frontal trough. NAM, Hi- Res ARW and NMM place the best chance of convection right thru the middle of the CWA running from Mansfield to Somerset thru the morning. NAM is much higher with the QPF than the GFS and HREF, though. Min temps overnight will be well above normal in the mid to upper 60s, and should break max min records (some over 100 years old!) once again by 3 degrees or more in the valleys and possibly by 8 or 9 deg F across the Mtns of western and northern PA. However, temps at many locations could cool off below those records by midnight Thursday night in moderately strong LLVL cold advection. Warmest mins for Oct 11 area as follows: KAOO 65 in 1970 KBFD 55 in 2017 KIPT 64 in 1913 KMDT 65 in 1914 && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... *Locally Heavy downpours and localized flooding possible Thursday. The PWATs remain well above normals, peaking about 2.25" during the day on Thurs over Lancaster County. There will be some heavy downpours in the sct thunderstorms embedded in the wider area of showers. In general, we would need to have some training of storms to make flash flooding in this scenario. While this is certainly possible, we are not confident enough in placement of the heaviest rain to post a flood watch at this point. NAM keeps the heaviest of the QPF over our central counties around sunrise, then another max occurs near or off to the southeast of Lancaster Co during the day. The wind will shift to the west as the front passes with a drastic drying to the air over the NW by the end of the day. Precip might be over by 18Z in the NW third-half of the area, and by 21Z over all but Lancaster and srn York Cos. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... *Significant cool-down expected by Friday as a more typical fall weather pattern finally takes hold into next week A significant pattern change is expected to follow in the wake of Hurricane Michael as it accelerates away from the southern Mid Atlantic coast on Friday. The extended summer pattern will come to an end with all signs pointing toward noticeably cooler, more typical fall weather lasting into next week. After one of the warmest starts to October on record, the upcoming period of seasonably cooler weather with near to below average temperatures will feel rather chilly this weekend and next week. Parts of the northwest Alleghenies may see frost Sunday morning. Sub-zero air at 850mb crossing the lower lakes should result in rain showers (perhaps the seasons first flakes?) over the NW Allegheny Plateau and Fri-Sat. Model consensus shows the next rain-maker impacting the area early next week, with weak cold frontal passages expected Monday and Wednesday. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... VFR now will start to deteriorate this evening, but probably crash hard before midnight in many locations. Have mentioned PROB30 for thunder in a broad time frame later tonight in many places, and through all the last 6 hrs (12-18Z) in the SE. The wind will not change appreciably through the night, but veer slightly through the latter half of the night. The front will move through BFD around or just after sunrise. Then, steadily cross the area through the daylight hrs. Strato cu moves in from the northwest after a brief dry slot/clearing behind the front. It should cover much of the area Friday and NW winds could gust into the 20s. Classic October. .Outlook... Sat...MVFR cigs possible NW. Sun-Mon...AM valley fog psbl...otherwise no sig wx. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Lambert/Dangelo NEAR TERM...Lambert/Dangelo SHORT TERM...Dangelo LONG TERM...Gartner/Steinbugl AVIATION...Dangelo