textproduct: Wilmington

WHAT HAS CHANGED

There is increasing potential for showers and thunderstorms late Tuesday night into Wednesday.

KEY MESSAGES

1) Showers and storms will move across the region this afternoon into the evening with more showers and storms Tuesday. And there will be a continued chance late Tuesday night into Wednesday morning. Locally heavy rainfall will be possible.

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

DISCUSSION

KEY MESSAGE 1) Well developed short wave in the mid Mississippi Valley will continue to progress northeast today. Already very moist atmosphere will become even moreso with the probability of precipitable water exceeding 2 inches being greater than 50 percent across western counties this afternoon. In addition, warm cloud depth will be around 4 km which suggests very efficient warm rain processes will be in play.

Guidance has been suggesting that arcing north northwest-south southeast bands of convection will develop and move into the area this afternoon into the early evening, but probably not making it all of the way into central and south central Ohio until well into the weakening phase later tonight.

00Z HREF and REFS LPMM QPF highlights the Miami Valley into the eastern part of the Tri-State with the REFS being just a bit further east than the HREF. And the 18Z GSL MPAS aligns closely with the HREF. So this appears to be the zone of greatest concern, although just about anywhere in the western part of the forecast area could get locally heavy rain.

Short wave will start moving east late tonight and cross the area during the day Tuesday. Precipitable water and warm cloud depths will be similar to today. However, the timing of the short wave may limit the intensity of convection until moving out of the area and with the impulse being progressive may lessen the potential for focused heavy rain in any one location. However, will still need to maintain a heightened awareness.

Some of the global models are suggesting that an MCS could drop southeast into the region late Tuesday night into Wednesday morning. Atmosphere may be marginally less juicy at that point but still sufficient to potentially lead to some heavy rain.

KEY MESSAGE 2) In the wake of any potential morning convection, mid level heights will rise on Wednesday. There has been a notable trend towards less amplitude in the ridge this far north over the past few days. Temperatures will still be able to rise into the mid to upper 80s, but the probability of 90 degrees or higher is now only 20 to 30 percent across parts of northern Kentucky and south central Ohio on both Wednesday and Thursday. However, with the dew point in the lower to mid 70s, there is a greater than 50 percent chance of the heat index being greater than 90 although only around a 20 percent chance of being as high as 95.

A vigorous trough working its way across the northern part of the country will suppress the mid level heights and likely push a cold front through the region on Friday. So temperatures will be not quite as warm but still above normal late in the week into the weekend.

AVIATION /12Z MONDAY THROUGH FRIDAY/

Mainly mid and high clouds to start the period. Scattered cumulus will develop with heating. Showers and some thunderstorms will develop and spread across the region as early as 18Z. Still not clear whether these showers or storms will impact any of the terminals, so PROB30 continues. And while the restriction is forecast at MVFR, it is entirely possible that visibility will be lower. Once showers and storms move east, there will be some residual mid clouds. But then an MVFR deck will develop in the latter part of the period.

OUTLOOK... MVFR ceilings are likely Tuesday with IFR ceilings and MVFR visibilities possible. MVFR ceilings and visibilities may linger through Tuesday night into Wednesday morning. Thunderstorms possible Tuesday through Friday, with the greater potential in the afternoon and evening.

ILN WATCHES/WARNINGS/ADVISORIES

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