


Area Forecast Discussion
Issued by NWS State College, PA
Issued by NWS State College, PA
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --223 FXUS61 KCTP 091839 AFDCTP Area Forecast Discussion National Weather Service State College PA 239 PM EDT Wed Jul 9 2025 .SYNOPSIS... * Scattered damaging wind gusts and flash flooding are possible across portions of south central and southeastern Pennsylvania this afternoon and evening * Continued seasonably warm and humid into mid July with daily chances for afternoon and evening thunderstorms && .NEAR TERM /THROUGH TONIGHT/... Areas of fog and low clouds early this morning will give way to a mix of clouds and sunshine. Max temps will be in the 80-90F range from NW to SE with slightly reduced humidity levels based on sfc dewpoints trending about 5 degrees lower vs. Tuesday. 500mb trough will move slowly eastward today across the Great Lakes/Ohio Valley. HREF data depicts a belt modestly enhanced southwesterly mid level flow that will contribute to slightly higher bulk shear values ~30kts than in recent days. This may be offset to some extent by drier/less humid air that will result in lower instability/CAPE across most of CPA. The area to watch will be over the southern tier particularly into the lower Susq Valley given juxtaposition of max CAPE/shear and 1.5-2" PWAT. Latest CAMs show T-storms initiating over far southwest PA into WV as shortwave energy rotates into the Upper Ohio Valley then ramps up in both coverage and intensity spreading eastward to the I-95 corridor by 00Z. For now, there appears to be a stronger signal for a heavy rain axis and corresponding flash flood risk farther to the south over northern MD, but we issued a flash flood watch from Adams to Lancaster County which could be impacted especially if convection trends farther to the north and west through the day. Showers and storms could persist into the overnight period in parts of south central/southeast PA before shifting to the north/east after 06Z. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... Diurnal heating of a seasonably moist and weakly capped boundary layer will result in afternoon thunderstorms through late week over CPA. Precipitable water values look to trend lower vs. previous days. This will reduce the excessive rainfall and flash flood risk while remaining sufficient to support the potential for wet downbursts and isolated wind damage. SPC has maintained a level 1 marginal risk for both D2/Thu and D3/Fri. Typical mid July summertime temperatures expected with daytime highs in the 80-90F range and lows 60-70F. && .LONG TERM /SATURDAY THROUGH TUESDAY/... Daily chances for afternoon/evening thunderstorms continue over the weekend and into early next week with max/min temps trending near to slightly above normal for mid July. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/...-- Changed Discussion --Variable cloudiness is expected this afternoon with scattered mid level clouds area wide and a deck of high level clouds moving in across the northwest. VFR conditions will prevail until scattered showers and thunderstorms begin to build later this afternoon and evening. A few light showers are possible at JST and AOO, perhaps even as far north as UNV, but any restrictions should be brief. Farther southeast, heavier showers and stronger storms are expected in MDT and LNS between 22 and 02Z with reductions to MVFR or IFR vis expected as storms move through. The forecast for tonight gets a bit more complicated in terms of cigs and vis. High clouds should limit the potential for radiation fog tonight, but moisture pooling as a result of recent rains could still lead to some fog/low ceiling potential. At this point, the best chance for radiation fog will be BFD and JST where clearing may build in before daybreak. Have indicated at least a period of MVFR restrictions at all airfields tonight, but confidence remains fairly low in the extent and duration of such impacts. Outlook... Thu...Restrictions in possible in scattered PM storms. Fri-Sat...Scattered afternoon/evening storms, mainly south. Sun...More widespread showers/storms likely. Mon...Still storms around.-- End Changed Discussion --&& .CTP WATCHES/WARNINGS/ADVISORIES...-- Changed Discussion --Flood Watch until 11 PM EDT this evening for PAZ064>066.-- End Changed Discussion --&& $$ SYNOPSIS...Steinbugl NEAR TERM...Steinbugl SHORT TERM...Steinbugl LONG TERM...Lambert/Colbert AVIATION...Banghoff