textproduct: Wilmington

WHAT HAS CHANGED

Lowered precip chances and subsequent threat of snow accumulation Sat night/Sun.

KEY MESSAGES

1) Temperatures above normal through Friday, with a chance for a few records to be set today.

2) Chances for showers and a few storms Thursday and Thursday night. Gusty winds Friday behind a cold front.

3) Below normal temps for next week. High uncertainty on precip chances Sat night-Sun.

DISCUSSION

KEY MESSAGE 1) Temperatures above normal, with a few records potentially broken today.

Using the 01:00 observations and current fcst, it looks like Dayton and Cincinnati could see record high mins for this date. For this, it will all come down to the temps recorded between 23:00 and midnight. Dayton needs to stay above 49, and Cincy above 53, which both look to be attainable. Sorry Cbus, your midnight temp of 50 doesn't keep you in the running as the record high min is 52.

After any morning showers that may occur, temperatures will rise as warmer air is advected on sw wind of 10-20 mph. Cloud cover will hold tough for the first part of the day but should break up later and could get that added kick of direct heating to push readings up to the mid 60s.

As far as breaking any daytime high temperature records the best chance will be at Dayton. Clearing skies look to be earliest here, and the forecast high of 65 could nose to the record of 66. Cloud cover should hamper records at Cincy and Cbus.

A warm front will cross the area on Thursday. Rain chances and clouds should limit excessive temperature rises, but well above normal temperatures will be a given. Readings begin to cool Friday as a cold front moves east through the region, with Friday max temps found in the morning ahead of the frontal passage.

KEY MESSAGE 2) Chances for showers and a few thunderstorms Thursday and Thursday night. Increased winds on Friday as a cold front moves through.

Latest SWODY2 has pushed the slight risk just a bit to the north, pulling in a few Ohio counties and removing a chunk of Kentucky counties. This does not change the overall expected weather. Southerly winds ahead of a sfc low will bring in moisture, which may interact with upper level s/w energy moving ene to produce showers in the afternoon. Rain looks to be favored best in the late day/early evening as a warm front develops ahead of the sfc low that will be situated along the IA/IL border at this time.

The low tracks ne towards LMich overnight and the wmfnt over the CWA also takes a ne trajectory. The warm frontal processes themselves will provide lift and favorable shear that will promote development of strong storms that will tap daytime heating and could produce damaging wind and possibly tornados. However, there is a dearth of instability that I would expect significantly curtails development of severe storms. My thought is that severity will be driven by direct heating/insolation that could be a bit difficult to produce given the model RH profiles.

Earlier discussion and another point of view is just as valid now as when it was written:

The surface low pressure off to the northwest promotes a favorable low-level wind shear profile with backing flow throughout the lower troposphere. This results in moderately curved hodographs, which are to be expected near the warm front. Despite the concerning hodographs, the lack of steep mid-level lapse rates, likely limits the ability for strong updrafts within the warm sector. Even more uncertainty remains with how long surface based thunderstorms may remain within the favorable atmosphere before the cooling temperatures in the evening decreases overall instability. Storms would require a long enough residence time to allow for organizations and the resulting hazards. CAM guidance is only just beginning to enter the time window, with a variety of solutions already advertised. So, while the general big picture potential is there, the details will be needed to better understand the possible hazards.

Breezy on Friday: As the cold front moves through during the day Friday, wind gusts of 25 to 35 mph are expected, especially across eastern Indiana, western and central Ohio.

KEY MESSAGE 3) Temperatures below normal next week and diminishing chances for precip this weekend, some of which would be snow.

Lowered the precip threat for Sat night/Sun and would have cared to eliminate them through at least 18Z Sun. Very strong height falls are indicated as equally strong s/w energy tracking quickly se develops into a deep trough or cutoff low. This drive seems to be a result of equally strong height rises in an impressively building ridge over the wrn U.S. Even though the rapid height falls and incoming low are there, the atmosphere in our region is simply not showing any indications of moisture for these dynamics to work on. If precip were to occur on Sat night, it would certainly be snow for the nw 1/2 of CWA and a mix in the se. Likewise, if said precip continued on Sun it would be all snow with the intrusion of cold air underneath building low pressure. Attm, I would be best inclined to keep a threat of snow in the northern Scioto Valley/Hocking Hills on Sun. I surmise that the increased moisture/cloud cover noted is strictly based on the rapid cooling induced with these height falls. Unfortunately, this looks to me to be the crux of development with this prominent feature as there is not enough moisture to start with.

The trough will provide a break from the above normal temperatures for a few days, with below normal values returning to the region into early next week. Low temperatures are coldest Monday and Monday night.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

Removed the wind shear from any of the TAFs as a 10-20 deg change and 30kt difference from sfc-2kft doesn't seem to warrant it. However, the wind speed aoa 2kft will be 40+kt through about 18Z and sfc winds will gust to 25kt early in the day. Did lower/remove gusts a little earlier than previous forecast as warm advection processes typically don't support them without stronger sustained winds.

Numeric guidance is still hitting the lower clouds in MVFR/IFR pretty well, and this does appear to be realistic looking at the 925 moisture profiles, which really don't start to dry out until 21-23Z.

Any shower activity this morning will be minuscule and quite brief. Used prob30 with MVFR vsby at CMH/LCK this morning, a very brief tempo with MVFR vsby in prevailing vcsh at DAY and ILN, and a prob30 of no vsby restrictions and IFR vsbys at CVG/LUK. All of these are out of the picture by 16-17Z, earlier at DAY where 14Z looked pretty solid for a point going forward without precip.

OUTLOOK...MVFR ceilings and thunderstorms are possible Thurs night. Gusts to 25-30kt behind a cold frontal passage early Friday.

ILN WATCHES/WARNINGS/ADVISORIES

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