textproduct: Wilmington

WHAT HAS CHANGED

Issued dense fog advisory

KEY MESSAGES

1) More heavy rain/flooding potential tonight into Thursday along with a limited potential for strong to severe storms this evening.

2) Near record temperatures possible Friday.

3) More showers and storms expected on Saturday.

4) Very warm temperatures and unsettled conditions return towards the middle of next week.

5) Dense fog overnight.

DISCUSSION

KEY MESSAGE 1) More heavy rain/flooding potential tonight into Thursday along with a limited potential for strong to severe storms this evening.

East-west frontal boundary remains across southern Indiana extending east near the Ohio-Kentucky border. Moisture convergence along this is fairly weak, but that has not precluded showers and storms to track just south of the boundary. For the early part of the afternoon, instability is minimal, but it will increase later this afternoon into the evening, particularly to the south and west of Cincinnati. MCS across Missouri to start the period will continue east northeast and move across the region late this afternoon into this evening. There could be enough instability across parts of northern Kentucky and southeast Indiana to allow for a strong or even marginally severe storm to occur.

In the wake of this MCS, expect something of a lull, although the surface boundary will have lifted further north into the area. Another disturbance that will strengthen a low level jet move move in late tonight into Thursday morning bringing more showers and embedded thunderstorms with a focus near the boundary's new location.

With very high precipitable water remaining in place, there will continue to be the potential for moderate to heavy rainfall in addition to repeated rounds of rain. The higher QPF axis does overlap with the area that got the most rainfall in the past 24 hours which brings even higher concern for flooding. Thus the initial flood watch has been extended to 18Z Thursday. There was a slight reorientation as the threat looks to not be as high for far southern counties, however heavier rain could be further north into central Ohio.

KEY MESSAGE 2) Near record temperatures possible Friday.

Mid level ridging will build in the wake of a short wave Thursday night with heights reaching their peak across the area on Friday. Southerly low level flow will increase and a very strong 850 mb temperature anomaly will be centered over the Great Lakes. Forecast highs are near record for March 6. Record warm lows are also possible.

KEY MESSAGE 3) More showers and storms expected on Saturday.

Sheared, positively tilted short wave is forecast to cross the region on Saturday. Expect a pre-frontal trough to accompany this with a cold front lagging and not moving through until Saturday night. There are timing differences within the ensemble suite which would have an impact on how much instability is realized across the forecast area. Probability of CAPE reaching 500 J/kg is only 30 percent in south central Ohio and northeast Kentucky. So the potential for strong storms looks limited with various AI forecasts having the maximum potential further east. There is a high probability of showers and storms but with it being progressive, heavy rainfall is a much lesser concern.

KEY MESSAGE 4) Very warm temperatures and unsettled conditions return towards the middle of next week.

Mid level pattern will gain amplitude again towards the middle of next week as a closed low moves into the central part of the country. This will allow temperatures to soar back into the 70s on Tuesday, although records are a bit warmer that day. There will be the potential for showers and storms, especially heading into Wednesday as a cold front pushes into the region.

KEY MESSAGE 5) Dense fog overnight.

Dense fog has developed and will continue to develop for several hours overnight primarily near Interstate 70 and Interstate 75 and points northwest. Issued a dense fog advisory.

AVIATION /04Z THURSDAY THROUGH MONDAY/

Unsettled weather pattern to continue with a qusai-stationay west- east oriented frontal boundary across the area. A couple of shortwaves to affect the area overnight into Thursday. A shortwave over the Lower Ohio Valley to track thru the area early tonight. Convection across southern and Central Indiana associated with this shortwave to track across the area this evening. Expect widespread showers with embedded thunder with the best coverage across East Central Indiana and West Central Ohio.

A second shortwave to track thru the Ohio Valley late tonight into Thursday morning. This feature will work to enhance coverage of showers and thunderstorms.

IFR ceilings will prevail through the night with LIFR ceilings and visibilities. Although it will not be raining for the entire time, especially with the minor break between shortwaves, visibility restrictions will continue in mist/fog even when showers are not occurring. Have shown an improvement to MVFR late in the TAF period after the second shortwave exits the area.

OUTLOOK...MVFR/IFR conditions will continue into Thursday. MVFR/IFR conditions will likely return on Saturday.

ILN WATCHES/WARNINGS/ADVISORIES

OH...Flood Watch through Thursday afternoon for OHZ053>056-060>065- 070>074-077>080-082. Dense Fog Advisory until 5 AM EST Thursday for OHZ026-034-035- 042>044-051-060-061. KY...Flood Watch through Thursday afternoon for KYZ089>093. IN...Flood Watch through Thursday afternoon for INZ050-058-059-066- 073>075-080. Dense Fog Advisory until 5 AM EST Thursday for INZ050-058-059.