Marine Weather and Tide Forecast for West Homestead, PA

NEAR TERM /UNTIL 6 PM THIS EVENING/
KEY MESSAGES:

- Scattered showers/thunderstorms early this morning with a warm front - Cold front brings more widespread showers/storms later today - Marginal Risk for severe storms this afternoon -------------------------------------------------------------------

Surface low pressure was centered across southern WI, with a warm front extending SEWD across central OH and nrn WV . A cold front trailed south of the low to the Mississippi Valley region. The warm front will continue to lift north across the Upper Ohio Valley region early this morning, with scattered showers and thunderstorms. Showers were developing on the leading edge of a secondary low level jet associated with the warm front. Weak elevated instability could also result in a few thunderstorms developing through the morning.

THe warm front should lift north of the region later this morning, as a prefrontal trough develops ahead of the approaching cold front. Some destabilization is expected after the passage of the warm front, and before the arrival of the prefrontal trough late this morning into the afternoon. In general, 500-750 j/kg of MU CAPE is progged in most of the CAMs this afternoon and early evening, with 40-50kt of 0-6km shear, enhanced by a mid level jet. A few storms could be severe, both with the prefrontal trough from early to mid afternoon, and with any potential redevelopment along the surface cold front later this afternoon and early evening. The main limiting factor in severe storm development will be the amount of instability that develops, depending on how the forecast conditions evolve through the day.

The Storm Prediction Center has included much of our region in a Marginal Risk for severe storms. The main hazard is expected to be the potential for damaging wind gusts with increasing flow aloft, though isolated embedded QLCS tornadoes are possible as 0-3km helicity increases with a veering wind profile.

High temperatures are expected to be 10 to 15 degrees above average with the area in the warm sector.

SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/
KEY MESSAGES:

- Showers/storms end this evening with the passage of a cold front - Dry weather then returns through Wednesday night -------------------------------------------------------------------

The prefrontal trough is expected to be just east of the area early this evening, as the surface cold front crosses the region. A potential for strong to severe storms will continue until FROPA, though this will depend on the amount of instability able to occur behind the prefrontal trough. Shower and thunderstorm chances will end after FROPA, with dry weather returning the remainder of the night.

Surface high pressure will slide east across the Upper Ohio Valley region later tonight through Wednesday night under zonal flow aloft, maintaining dry weather through Wednesday night.

After a brief cool down on Tuesday behind the cold front, temperatures will return to readings around 10 degrees above average by Wednesday.

LONG TERM /THURSDAY THROUGH SUNDAY/
KEY MESSAGES:

- Increasing shower chances through late week into Saturday - Dry weather returns for the end of the weekend

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Model ensembles indicate zonal flow aloft early in the period will become more amplified by late week. A trough is expected to develop across the central CONUS on Thursday. Increasing moisture and warm advection ahead of this trough should return shower chances to the area late Thursday and Thursday night. The trough, and its associated surface cold front, is expected to track across the Upper Ohio Valley region Friday and Friday night, with the highest chances for showers and possible thunderstorms. The trough and front should exit the region early Saturday, with showers ending from W-E.

Ridging, between the exiting trough to the east, and a developing western CONUS trough, should return dry weather to the region Saturday night and Sunday as it builds across the Upper Ohio Valley region. Above average temperatures are expected to return to seasonable levels after the passage of the trough.

AVIATION /10Z MONDAY THROUGH FRIDAY/
A few scattered showers have formed generally north and west of the PIT/AGC/BVI area to start the TAF period as a warm front makes its way through the area. These will continue to move northeastward, potentially bringing very brief periods of -RA at these sites as well as FKL and DUJ through early morning.
However, little impact is expected due to dry near-surface air promoting sub-cloud evaporation and therefore limiting any drops in visibilities or ceilings. For now, the probability of lightning occurring in these showers remains too low to warrant including in TAFs, however it is not out of the realm of possibility (~30% chance or lower).

There will be a briefing break in shower and thunderstorm activity during mid to late morning hours ahead of an approaching cold front. Heavier showers increase in coverage ahead of the front after 17Z (closer to 15z at ZZV) as a pre- frontal trough enters the area. Embedded thunderstorms will also be possible as probabilities for thunder increase to 30-50%, though these are still too low to warrant a prevailing mention in TAFs, so opted instead to go with prevailing -SHRA and PROB30's with -TSRA. Strong wind gusts and restrictions may accompany the heavier showers and thunderstorms.

The cold front itself moves through following the pre-frontal trough, with some potential for a quasi-squall line feature along the front if instability warrants. The frontal passage will mark the end of precipitation as winds veer to westerly or northwesterly. Some periods of MVFR ceilings may follow the front, particularly closer to the higher terrain and north of I-80 where upslope flow and influence from Lake Erie, respectively, will continue to promote low cloud development.

Outlook...
VFR and mostly dry weather return Tuesday and Wednesday, followed by another weather system bringing increasing chances for rain and restrictions late this week.

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