Marine Weather and Tide Forecast for Wrightsville, PA

NEAR TERM /UNTIL 8 AM THIS MORNING/
Rain is already beginning to overspread the western portions of Pennsylvania as of 00Z. Rainfall will remain relatively light given weak vertical forcing along a surface trough ahead of the main low, which is moving across central Illinois. The heavier rain is still expected to arrive in the southwest during the early morning hours just before sunrise as the warm front ushers in a plume of moisture and southeasterly flow.

Previous Discussion...
Clouds will continue to increase from the Ohio Valley through the evening. Main focus will shift to a widespread soaking to potentially flooding rain event starting early Wednesday morning.

Hires model data indicates a signal locally heavy rain (1-1.5")
focused into the eastern slopes of the Laurel Highlands between 06-12Z Wed. Moist upslope flow and low level moisture flux to do not look as impressive as the recent flooding event, but certainly enough to cause runoff problems given highly sensitive soil and very saturated terrain. We were keen to hoist a flood watch in collaboration with LWX and PBZ for Somerset and Bedford Counties starting 09Z/5AM Wednesday.

SHORT TERM /8 AM THIS MORNING THROUGH THURSDAY NIGHT/
Soaking rain overspreads central PA from southwest to northeast Wednesday morning. Timing of the rain and cloud cover will make for a very cool/raw/soggy day by late May standards and a gusty southeast wind will definitely add to the chill factor. Daytime max temps in the 50s are 10 to 20 degrees below the historical average.

Hires model signal for some convectively enhanced rain is focused over western and southwestern PA tomorrow afternoon with point amounts around 2" possible based on the HRRR 3hr PMM. The eastern 3/4 of central PA will be very stable in classic CAD signature sfc pattern, so we are not expecting any heavy rain over this area on Wed. The Flood watch continues until 09Z Thu/5AM and captures any additional heavy rain that may fall across the Laurel Highlands.

Broad cyclonic flow and cool air aloft will continue frequent rain showers through Thursday. There may be some locally enhanced rainfall on Thu where FGEN banding sets up. It will be a very cool and wet stretch through the short term period.

LONG TERM /FRIDAY THROUGH TUESDAY/
Northwesterly flow in the wake of the departing low pressure system will allow for cooler than average temperatures to take hold for the end of the week and throughout the Memorial Day weekend. A secondary area of surface low pressure is progged by model guidance to form off the Mid-Atlantic Coast late Thursday/early Friday will quickly pull northeast of the area, allowing for conditions to begin to dry out late Friday night.
Any lingering rainfall on Friday is expected to generally light and taper off southwest-to-northeast.

Enhanced northwesterly flow Saturday and Sunday will bring a return to shower chances with upslope and lake-enhanced showers; however, as low-level flow begins to decrease later in the evening, gradually will see shower activity shut off with lingering precipitation generally expected to be light. Guidance has trended drier on Sunday, with chances for any shower activity limited to the evening hours. The next batch of precipitation is expected to begin drifting north into central Pennsylvania on Monday and into Tuesday, promoting rain chances once again for the forecast area.

AVIATION /08Z WEDNESDAY THROUGH SUNDAY/
Current observations indicate that only JST and AOO are sub VFR attm, where it has been raining the longest, with VFR elsewhere across the airspace. However, as rain showers become more widespread and develop into steady light to moderate rain overnight into post-sunrise Wednesday morning, flying conditions are expected to deteriorate and remain so for most of the day on Wednesday.

Recent guidance does outline widespread IFR conditions with high confidence after 12Z Wednesday and throughout the end of the TAF period. LIFR conditions cannot be ruled out at BFD/JST/AOO/UNV; however, recent guidance has trended away from these conditions prevailing, so have lower confidence and have limited these mentions to the AFD. Thunderstorm potential at JST/AOO will be possible during the afternoon/evening; however, confidence also remains too low at this time for mentions in the 00Z TAF cycle.

Outlook...

Thu-Fri...Ocnl SHRA/TSRA.

Sat & Sun...Still a chance of a shower.

HYDROLOGY
Flood watch issued for Somerset and Bedford Counties from 5AM-5AM Wed-Thu.

7 fcst points are projected to exceed action/caution stage over the next couple of days.

Confluence is the most likely to reach/exceed minor flood stage, but is currently forecast to crest a foot or so below at this time. Juniata basin points are probably the next most vulnerable followed by the West Branch Susq and then middle to lower Susquehanna Basin tribs.

CTP WATCHES/WARNINGS/ADVISORIES
Flood Watch through late tonight for PAZ033-034.