Marine Weather and Tide Forecast for West Alexander, PA

KEY MESSAGES
1) Showers and ridgetops winds with a passing disturbance tonight; warming trend through mid-week.

2) Rain and snow potential increase late-week.

DISCUSSION
KEY MESSAGE 1...
A passing disturbance is expected tonight as a shortwave rounds an eastern trough. Mid-level ascent will invoke showers, with the only chance of accumulations north of I-76. Areas with a >30% chance of 0.1" only linger for northern Venango County and Forest County With temperatures in the upper 30s / low 40s, this will likely fall as rain, save a chance of graupel should any showers be more robust.

This shortwave will enhance the synoptic wind gradient across the region. With most areas expected to be below a low-to-mid level inversion, winds will not be particularly strong, but for eastern Tucker County, there is a chance that ridgetops may briefly poke into the inversion, prompting the issuance of a Wind Advisory from 7pm to 10am Monday. Most winds >45mph, if any, are expected on peaks above 4kft, with chances in Davis/Thomas of those same winds at a more marginal 40% to 60%.

After this shortwave passage, ridging and a temperature rises are expected through mid-week. High temperatures will reach 5-10F above normal Tuesday into Wednesday.

KEY MESSAGE 2...
A turn to troughing is favored Wednesday into Thursday, though ensemble clustering is still deviant on the trough depth. Some take it from Quebec back to the Great Plains, while others take into the upper midwest. This will in-tun, force where the surface cyclogenesis response. By Thursday into Friday, most scenarios fall into 3 camps:

1) Weak and eastern trough axis. These scenarios are considerably drier with the trough mostly passing as a shortwave, leading to little rain accumulation and no snow accumulation. Temperatures are "warmer than the ensemble mean" but highs still dip into the 40s late week.

2) Deeper, northeast trough axis. This brings more rain and even some snow (most likely for high terrain).This is primarily focused Thursday into Friday.

3) Deeper, midwest trough axis. This also bring more rain and perhaps some snow, but peak accumulations are delayed by 18 to 24 hours, mostly on Friday into Saturday.

Scenarios 2/3 show the potential for "at least" advisory level snow in the high terrain of West Virginia, with the terrain of Pennsylvania more marginal. Chances of any snow accumulation in the Pittsburgh metro are still low. There is only a 20% chance of any accumulation, and a <5% chance of an inch.

AVIATION /15Z SUNDAY THROUGH THURSDAY/
Lingering low-level stratus is fleeing eastwards as high pressure and dry advection slide in from the west. Northern and eastern ports may have a few more hours of MVFR after which, widespread VFR is expected through the day Sunday. Mid-level clouds filter in from the north ahead of a weak wave expected overnight into Monday. WSWerly winds gust up to 25 knots today.

A passing cold front tonight into Monday brings a chance for MVFR and rain north (most likely for DUJ/FKL/BVI).

Outlook...
High pressure settles back in later on Monday and is expected to return VFR to area ports until our next chance for rain climbs through the Ohio Valley on Thursday.

PBZ WATCHES/WARNINGS/ADVISORIES
PA...None.
OH...None.
WV...Wind Advisory from 7 PM this evening to 10 AM EST Monday for WVZ514.