textproduct: State College

WHAT HAS CHANGED

* No significant changes. Continuing to monitor flash flooding and severe storm potential through the evening.

KEY MESSAGES

1) Potential for heavy rain/localized flooding and isolated strong to severe storms this afternoon into tonight

DISCUSSION

KEY MESSAGE 1: Potential for heavy rain/localized flooding this afternoon into tonight

12hr rainfall through noon EDT was generally 0.50-1.50 falling to the west of US-15. This has lead to some pre-saturation which could play a factor if additional heavy rain develops over these areas.

Extensive cloud cover and time of day contributed to higher stability and effectively capped max rainfall rates below 1"/hr. The environment has been undergoing some modest destablization into the afternoon with thermodynamic mesoanalysis depicting SB/MLCAPE values on the rise with plenty of moisture available (1.5-2.2" PWAT). The destabilizing boundary layer interacting with a positively titled shortwave trough extending from Lower MI southwestward into the Mid-South will result in expanding coverage of heavy showers/t-storms with more intense rain rates which should lead to increasing flash flood potential through the rest of the afternoon into the evening hours. Breaks in the clouds particularly entering the western part of the CWA could also spell an uptick in t-storm intensity and potential for isolated strong to severe storms. WPC and SPC made very little to no changes to the 16/1630Z updates to the ERO and SWO for the rest of today. Cluster of storms with heavy rain working northward from DC/northern MD into the Lower Susquehanna Valley also is worth watching for more of an urban flash flood threat (given less compromised FFG) and low-topped spins. Expect heavy showers and storms to slowly progress eastward through tonight and can't rule out some localized runoff issues outside the watch area farther to the east through the Susquehanna Valley.

For now, the best heavy rain/severe wx signal is to the south and east of CPA tomorrow/Monday. Heading into the work week, latest model QPF data now favors a possible break in the rain through early week before daily shower/t-storm chances return Wed-Fri. Some localized heavy rain and marginal flooding risk will continue into late week.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

As of 18Z, showers are continuing to traverse central PA providing restrictions, particularly in embedded heavy downpours that restrict visibility. Over the next few hours, this round of precipitation will exit most TAF sites. This indicates a respite in IFR conditions in between rounds of precipitation where a few hours of MVFR restrictions may be favored in the afternoon. BFD remains most likely to prevail IFR, but some lifting to MVFR remains possible there too in this window.

Cloud breaks are being noted south of the Mason-Dixon Line and in eastern Ohio, which is allowing for some convective storm development in those areas. Have placed TEMPO groups in where the most confident timing is for potential thunderstorms at BFD, JST, AOO, and UNV. Confidence in exact timing remains lower at MDT and LNS so opted for PROB30s for thunderstorm mentions, although amendments may be necessary as real time development is observed. Gusty winds may accompany the strongest cores of precipitation that develop region wide, as well as visibility restrictions due to heavy rain.

Precipitation should mostly clear by 06Z but restrictions down to IFR are likely to follow region-wide. Latest guidance indicates LIFR appears most likely at BFD, JST, UNV, and IPT. These IFR conditions are likely to linger to daybreak at most TAF sites before MVFR becomes the favored regime later tomorrow morning.

Outlook...

Mon-Thu...Unsettled through midweek with daily chances for showers and isolated t-storms. Low VFR to MVFR conditions prevailing most of the time.

CLIMATE

Here are a few key climate callouts to wrap up July 2026:

2nd wettest at Bradford (7.78"/+3.62" above normal)

6th wettest at Altoona (6.18"/+2.70" above normal)

10th wettest at State College (6.09"/+2.30" above normal)

6th most # of days with maxT >=100F at Harrisburg (3) T3rd most # of days with maxT >=100F at Williamsport (2)

In August, the daylength decreases by 2-2.5 min/day with a total loss of ~ 70 minutes by the end of the month.

CTP WATCHES/WARNINGS/ADVISORIES

Flood Watch through late tonight for PAZ004>006-010>012-017- 018-024-025-033-034.