Titusville, PA 16354 Weather

What Has Changed

Fog looks widespread and locally dense in NW and north central Ohio again late tonight through midday Saturday.

Key Messages

1) Dry and seasonable conditions will continue through next week. Fairly widespread, locally dense fog will impact NW and north central Ohio again tonight and to a lesser extent Saturday night.

Discussion

KEY MESSAGE 1... A well established mid/upper Omega Block will continue through early next week, characterized by a couple of closed lows rotating into the Four Corners region and Rockies and another trough and associated closed low gradually lifting northeastward from the Mid Atlantic region, with a sharp ridge in between over the central CONUS. The southern Great Lakes and Ohio Valley regions will remain favorably placed beneath upper level confluence, maintaining strong surface high pressure of Canadian origin. This surface high is centered over eastern Ontario and Quebec this afternoon and will gradually progress south into the southern Appalachians and Mid Atlantic region by late Sunday and Monday. This will continue the familiar pattern of mostly clear skies, light winds, and seasonable temperatures through Monday, but afternoon highs will be slightly warmer as a SE return flow develops (mid/upper 60s Saturday and upper 60s/low 70s Sunday and Monday). The main weather impact will be overnight and morning fog. Light NE winds off Lake Erie again this afternoon have advected slightly higher dew points into NW and north central Ohio, and this low-level moisture will aid in small temp/dew point depressions and low-level saturation beneath the strong inversion again tonight. The fog was locally dense this morning across NW Ohio and lingered through about 17Z, so expect a similar scenario again late tonight through Saturday morning. The most widespread fog will occur in NW and north central Ohio, but patchy fog is possible elsewhere as well. This same scenario will likely play out again Saturday night into Sunday morning, but more of a SE flow during the day Saturday should keep low- level moisture in-check, so do not think it will be as widespread.

A weak cold front associated with a mid/upper shortwave dropping through the eastern Great Lakes will drop through the area Monday, but very dry air should lead to a dry frontal passage. Cooler conditions are expected post front Tuesday as another Canadian high builds down into the Great Lakes, but the pattern looks to evolve into more of a quasi-zonal mid/upper flow across the CONUS as the week progresses due to the low/trough off the East Coast pulling away and strong Pacific jet extension into the West Coast. This will support a warming trend for mid and late week.

Marine

Quiet marine conditions will continue through early next week as high pressure over the eastern Great Lakes gradually slides south to the Mid Atlantic and Appalachians by late Sunday and Monday. This will allow NE winds this afternoon to become light E to SE tonight and Saturday before turning SSE at 5-10 knots Saturday night into Sunday. Winds will turn SW at 5-10 knots Sunday night ahead of a weak cold front, then NW behind the front Monday afternoon, with speeds still in the 5-10 knot range. We will need to watch for possible Small Craft conditions Monday night and Tuesday as a Canadian high building into the central Great Lakes sets up NE winds near 20 knots, but expect quiet conditions to return by Wednesday as the high drifts east.