Marine Weather and Tide Forecast for West Homestead, PA

NEAR TERM /UNTIL 6 AM THIS MORNING/
KEY MESSAGES:

- Mainly dry overnight

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A surface cold front was analyzed from just south of DUJ, to BTP, to north of PHD. The front will continue to drift south overnight before stalling across the region on Friday. Capping aloft and a lack of significant moisture with the front precluded any precip from developing this evening, and this should continue overnight.

The 00Z PIT sounding showed the cap at around 800mb. Dry air was also observed through most of the column, with high level moisture increasing with the cirrus overspreading the region.
Overnight lows are expected to be around 5 degrees above average.

SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/
KEY MESSAGES:

- Daily thunderstorm chances with heavy rainfall threat Friday and Saturday.
- Temperatures dipping closer to normal but still humid with warm overnight lows.
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A more active Friday and weekend is in store as the aforementioned boundary remains stalled and wiggling over our area. A renewed push of southerly flow on Friday will pump PWAT values around 1.5". The boundary will lift north as a warm front and leave our area in the open warm, moist sector. Thick cloud cover should prevent notable destabilization, but skinny MUCAPE around the 400-800 J/kg range coupled with weak flow and PWATs pushing the 90th percentile of climatology will point toward a locally heavy rainfall and flash flooding threat. Some scattered showers may be around in the morning with low probability thunder, but more widespread thunderstorm development is likely after 12 or 1pm with achievement of convective temperatures. Exact placement of initiation will be tough to forecast, and further development may be tied to cold pool/outflow boundary progression. HRRR probability for >1"/hour rates in any given hour from 12pm-6pm is up to 50%.

Saturday looks to be a similar setup to Friday though with a potentially higher heavy rainfall threat. PWAT values rise a bit more with high probability for >1.5" and 40-60% chance of >1.75". In turn, DCAPE values will be lower given a more moist column, so the severe weather threat will be lower. Still, a 50-80% chance of >500 J/kg of SBCAPE, highest south of Pittsburgh, and continued weak deep layer flow will provide a good environment for more slow moving afternoon convection. With the potential for Friday to prime the ground for the next round on Saturday, WPC has kept the entire area in a Marginal Risk (1/4) for excessive rainfall.

Given the cloud cover and higher precipitation probability, temperatures will dip closer to normal over the weekend but still remain quite humid with dew points in the upper 60s and little relief at night with lows in the 60s.

LONG TERM /SUNDAY THROUGH THURSDAY/
KEY MESSAGES:

- Precipitation chances continue into next week.
- Temperatures favored to climb above seasonal normals.
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By Sunday, surface low pressure is favored to develop across the Ohio Valley as an upper wave approaches. This will begin to push the stalled boundary to the east but precipitation chances still continue as it slides by. Latest clustered ensemble runs have trended deeper and slightly slower with the upper wave progression, and in this scenario, Sunday may see continued flooding and low severe threats. If a faster scenario (lower probability) takes hold, both of those threats would lower and temperatures would be cooler.

Temperatures are favored to rise again throughout the week and eventually end up back above normal, but daily rain chances continue with passing waves of low pressure. Uncertainty grows by mid-week with spread in MaxTs around 5-8 degrees. The pattern looks to remain active with machine learning guidance pointing toward low end severe chances through the end of the week.

AVIATION /07Z FRIDAY THROUGH TUESDAY/
General VFR is expected through this evening with light wind, though restrictions will be possible this afternoon with showers and thunderstorms. Probability for iso/sct convection increases after around 18z, but coverage will likely be spotty. Continued to carry PROB30 groups for most sites during the afternoon timeframe to account for this. Afternoon storms will be fairly disorganized, but will carry downburst potential.

Widespread rainfall with embedded thunderstorms becomes more likely closer to 00z, continuing into the overnight. Thunder probs will gradually ease through the night. Ceiling swill begin to lower after 00z, with widespread IFR likely by 09z Saturday.
Wind remains light through the period.

Outlook...
Restriction potential with rain will continue through the weekend and into early next week with little change in pattern as a series of disturbances cross the area.

PBZ WATCHES/WARNINGS/ADVISORIES
PA...None.
OH...None.
WV...None.