Lawrence Park, PA Weather

What Has Changed

There are no major changes to the ongoing forecast.

Key Messages

1) Dry, seasonable weather will continue through the first half of next week before a warming trend. Overnight and early morning fog will continue in NW Ohio and interior portions of NE Ohio/NW PA, but coverage will trend lower through Monday.

Discussion

KEY MESSAGE 1... The southern Great Lakes and Upper Ohio Valley regions will remain locked in the familiar weather pattern through early next week. An Omega Block, characterized by a couple of mid/upper troughs and closed lows rotating into the Rockies and Four Corners regions and another trough/closed low set up off the East Coast with sharp central CONUS ridging in between, will gradually break down through Monday. This will allow strong Canadian high pressure at the surface, currently centered over southern New England, to drift south into the Mid Atlantic and southern Appalachians by Monday. Another night of clear skies and light winds with the high nearby tonight will allow lows to dip into the upper 30s/low 40s, with some low 30s in far NE Ohio and NW PA. Patchy frost is possible in those areas away from the lake, but it will be of minimal impact since the growing season has already ended up there. The bigger impact will be areas of fog again tonight and Sunday night, but increasing SE return flow to mitigate a daily lake breeze will start to lower dew points enough to limit fog coverage at night. Expect decent fog coverage in NW Ohio and interior parts of NE Ohio/NW PA again tonight since sufficient low-level moisture and small temp/dew point spreads will remain below the inversion, but coverage will be less than last night and will further trend less Sunday night.

A mid/upper shortwave dropping through the eastern Great Lakes Monday will drive a weak cold front through the area Monday afternoon, but very limited moisture return will lead to a dry frontal passage. The main impact will be a brief cool down, with highs in the upper 60s/low 70s Monday cooling into the upper 50s/mid 60s Tuesday as a new Canadian high builds down across the Great Lakes. However, starting Wednesday and on into next weekend, a strong subtropical Pacific jet extension (a response to the powerful El Nino) will drive a series of storm systems into the West Coast. This will build an expanding mid/upper ridge over the eastern CONUS leading to a big warming trend. Widespread 70s are possible the second half of the week and into next weekend, with continued dry conditions until a cold front possibly approaches late Saturday.

Marine

Quiet conditions will continue on Lake Erie through Monday as high pressure gradually drifts south along the East Coast. Light winds this afternoon will turn generally S at 5-10 knots tonight and Sunday before turning SW at 5-15 knots Sunday night ahead of a cold front. Winds will turn N behind the front Monday afternoon then NE Monday night and Tuesday while increasing to 15-20 knots. Small Craft headlines are possible Monday night/Tuesday since winds have been trending a little higher. Winds will gradually diminish Tuesday night while turning ESE, with ESE winds of 5-10 knots Wednesday. A warm front lifting across the lake Wednesday night will set up stronger SW winds Thursday, but they look to stay below Small Craft criteria at this time.