textproduct: Wilmington

WHAT HAS CHANGED

Heavy rain potential has shifted and is now more focused on northern Kentucky, southeast Indiana, and southern Ohio.

KEY MESSAGES

1) Showers and thunderstorms could produce locally heavy rainfall today and then again late tonight.

2) Very warm temperatures will develop in the middle of the week.

3) A cold front will move through the area on Friday bringing less humid conditions for the weekend.

DISCUSSION

KEY MESSAGE 1) Convectively enhanced short wave moving into central Kentucky will continue moving east northeast across the commonwealth today. Expect showers and some thunderstorms to increase in coverage and pass across areas near and south of the Ohio River this morning into mid afternoon. North of this, a progressive band of additional scattered to numerous showers and storms will develop and move across the region.

Precipitable water will remain near 2 inches and warm cloud depths are at least 4 km, which indicates efficient warm rain processes. So any more robust convection may produce heavy rainfall, but the risk of that accumulating substantially in any one location and thus leading to the potential for flooding will be limited to the activity associated with the impulse moving across Kentucky today.

Another weak disturbance is forecast to move east southeast tonight and result in an MCS tracking from central Illinois into eastern Kentucky. While there are some variations in the exact path of a convective system, from an ensemble perspective the HREF is keeping this south of the forecast area while the REFS indicates some potential for the northern edge to affect some areas south of the river. The atmosphere will be just a primed for heavy rainfall. So will have to maintain vigilance late tonight.

KEY MESSAGE 2) Mid level ridge will develop into the region on Wednesday and then get pushed a little further east on Thursday as a substantial trough makes its way across the continent. Less cloud cover is forecast and while diurnal convection cannot be ruled out, it looks isolated to scattered at best. So temperatures will be able to warm into the mid to upper 80s. Probability of air temperature reaching 90 remains low (less than 30 percent), but with dew points in the 70s, apparent temperature will rise into the mid to upper 90s.

KEY MESSAGE 3) Short wave lifting northeast through the Great Lakes on Thursday night will take a surface low from Wisconsin into Ontario. Trailing cold front is forecast to approach the forecast area and possibly reach western counties by daybreak Friday. Secondary short wave will help push this front east of the forecast area by mid afternoon. Given the time of day this is forecast to cross the region, convection has less of a chance to become robust.

There will be a noticeable drop in dew points for the weekend. Air temperatures will not be quite so warm but still a few degrees above normal.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

Development of MVFR ceilings has been delayed a bit from earlier expectation, but these are still forecast to move into the TAF sites early in the period. The potential for falling to IFR has decreased, although it is not completely out of the realm of possibility, but even so would be brief.

Showers and some thunderstorms will track across the region today may bring visibility restrictions. Clouds will start to break after precipitation moves east, although scattering and losing the ceiling may not occur until closer to 21Z. Low ceilings will redevelop late in the period with most indications that those clouds will be IFR.

OUTLOOK... MVFR to IFR ceilings are likely into Wednesday morning. Thunderstorms remain possible Wednesday and Thursday in the afternoon and evening and then through the day Friday.

ILN WATCHES/WARNINGS/ADVISORIES

OH...None. KY...None. IN...None.