textproduct: Wilmington

WHAT HAS CHANGED

Increasing confidence when the greater potential for precipitation will occur through the week.

KEY MESSAGES

1) More showers as well as some thunderstorms will occur again today with locally heavy rainfall possible.

2) Temperatures will warm above normal for much of the week. Greatest potential for more showers and thunderstorms will be Wednesday.

DISCUSSION

KEY MESSAGE 1) Short wave will move from the Tennessee Valley into the upper Ohio Valley today while a second impulse tracks from the mid Mississippi Valley into the lower Great Lakes. These will both provide lift for more showers and some thunderstorms today, particularly during the usual diurnal peak.

Moderate southwesterly low level flow associated with the southern wave will create a zone of moisture transport from eastern Kentucky across the southeastern part of the forecast area into eastern Ohio. Precipitable water will increase back to 1.7-1.8 inches in that axis with the warm cloud depth not quite as deep as the previous few days. This will create an environment favorable for locally heavy rainfall south and east of I-71. HEFS, which did a rather good job highlighting the axis of heavier rain in the I-75 corridor yesterday, does not have anywhere near the concentrated axis of QPF for today. REFS is a bit bolder, but did not verify as well yesterday. So, some localized flooding issues cannot be ruled out, but the probability of flash flooding seems low enough at this stage to preclude a new watch. However, trends will continue to be monitored in case the threat potential increases.

KEY MESSAGE 2) 00Z model suite has come into better agreement in handling an old quasi-stationary front which will be located just south of the region on Monday. This boundary may be close enough to result in some diurnal convection for areas near and south of the Ohio River both Monday and Tuesday. POPs look overdone, especially Tuesday, which is probably due to the NBM lagging in picking up trends in guidance.

It appears that the front will nudge northward on Wednesday, so that will be the day with the greatest potential for showers and thunderstorms, especially south of I-70. The front will get pushed back south by Thursday and end up even further south than the early part of the week as high pressure builds across the Great Lakes.

Rising mid level heights and less cloud cover will allow daytime temperatures to rise above normal, which is in the mid 70s. Lows will continue to run slightly above normal as well. But as high pressure moves south and heights fall as mid level troughing deepens over the northeast late in the week, temperatures will cool to or fall a bit below normal.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

Generally MVFR ceilings across the area will continue through much of the day, although there may be brief periods with a lower or higher flight category. Showers will increase in coverage during the day with some thunder possible with the better chance of the latter occurring in the Columbus area. Showers will move out before 00Z with ceilings improving or ending shortly thereafter. However, there may be some fog and low cloud development late in the period, primarily from KCMH/KLCK to KILN.

OUTLOOK...MVFR to IFR ceilings and visibilities are possible into Monday morning. Thunderstorms possible Wednesday.

ILN WATCHES/WARNINGS/ADVISORIES

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