Marine Weather and Tide Forecast for Highland Holiday, OH

KEY MESSAGES
1) A deep low pressure system brings the chance for severe thunderstorms, isolated flooding, and gusty winds this afternoon into Thursday. The most widespread severe storm risk will be tonight.

DISCUSSION
KEY MESSAGE 1)

Mid level short wave energy moving through the Great Lakes will lead to a developing surface low over the upper Mississippi Valley this morning. The low will then deepen through tonight as it pivots through the Great Lakes region overnight into early Thursday. A trailing cold front will push southeast across our area later tonight into Thursday morning. Ahead of the low, a 70 knot 850 mb jet will shift eastward across our area tonight, with good moisture advection up into the region and PWs increasing to around 2 inches or so.

Shower activity currently back across northern Iowa/southern Minnesota is forecast to continue to move southeast this morning and increase in coverage and intensity through early afternoon as the airmass destabilizes ahead of it. There are some model differences on just how far southeast this pcpn will make it through mid to late afternoon, with several of the CAMs trying to bring at least some of this pcpn into our northwest areas through late afternoon. Depending on how this plays out, this could affect the degree of instability present across our area later this afternoon into early evening.
Nonetheless, the general trend is to allow for instabilities to nudge back up through this evening in developing low level theta e advection into our area. This should allow for more widespread showers and thunderstorms back to our northwest to push southeast across our area through the overnight hours. While damaging wind will be the main severe weather threat given the strong wind fields, impressive low level shear/hodographs will support a secondary threat for possible tornadoes and perhaps large hail. The highest severe threat will be along and northwest of the I-71 corridor, where the better instability/stronger forcing will exist.

The other concern will be locally heavy rainfall and the potential for flash flooding. As the storms congeal into more of a line of overnight, they should be somewhat progressive as they move through our area. However, given the high PWs, some localized rainfall amounts in excess of 2-3 inches will be possible with any training storms. There appears to be some signal in the HRRR that the best chance for this would be across our far western/southwestern areas overnight.

Meanwhile, given the strengthening pressure gradient, gusty winds of 30-40 mph will also be possible outside of the storms tonight into Thursday.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
Shower activity across the Tri-State area should taper off from the west through the early morning hours, but these will likely affect KCVG/KLUK in the first hour or so of the TAF period. Otherwise, expect mainly dry/VFR conditions to prevail through the morning hours. Clouds will begin to increase through this afternoon as a convective complex approaches the region from the northwest later this afternoon into early evening. There is some uncertainty with how well this will hold together as it moves into our area later this afternoon, so will just include a prob30 -shra at KDAY for now to account for this possibility.

More widespread showers and thunderstorms will move southeast across our area overnight ahead of an approaching cold front. These storms will be capable of producing very heavy rainfall and wind gusts in excess of 40 knots. Will cover this threat with a few hour tempo group for TSRA at all of the TAF sites.

OUTLOOK...Winds gusts at or above 30 kts possible Thursday.

ILN WATCHES/WARNINGS/ADVISORIES
OH...None.
KY...None.
IN...None.