Severe Storms Possible Monday Feb 27th

Posted on 26th Feb 2023

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL ILLINOIS INTO PARTS OF FAR NORTHERN KENTUCKY AND FAR SOUTHWEST OHIO...

...SUMMARY... Thunderstorms associated with damaging winds will be possible on Monday across parts of the lower Ohio Valley.

...Lower Ohio Valley... A negatively tilted upper-level trough will move quickly east-northeastward across the southern Plains tonight and into the lower Ohio Valley on Monday. Early in the period, a cold front in the mid Mississippi Valley, along with a preceding tongue of maximized low-level moisture, will surge eastward. Thunderstorms appear likely to be ongoing at the start of the period near the Mississippi River from far southeast Iowa southward into far eastern Missouri. This convection will move quickly eastward across the Ohio Valley early in the day, approaching the Appalachian foothills during the afternoon.

A focused 90 to 100 knot mid-level jet will quickly translate eastward across the lower Ohio Valley Monday morning. This speed max will influence winds near the surface. NAM forecast soundings between 12Z and 18Z between Lincoln, Illinois and Cincinnati, Ohio suggest SBCAPE will peak near 500 J/kg. Winds right above the surface are forecast in the 40 to 50 knot range. Convection should be able to drive these strong winds to the surface, resulting in an isolated wind-damage threat. The greatest threat should exist along the leading edge of any line segment that can remain intact during the morning, before the upper-level trough outruns the moist axis. Although there is some conditionality with this forecast, the potential for a cluster of wind reports appears substantial enough to continue a small and focused slight risk. The slight risk is concentrated where the low-level jet and greatest convective potential is forecast to become juxtaposed Monday morning.