textproduct: Wilmington

WHAT HAS CHANGED

Isolated storms possible this afternoon and evening. Another chance for showers and storms later tonight.

KEY MESSAGES

1) Warm and humid conditions this afternoon/evening. Isolated to scattered thunderstorms are possible this afternoon. Additional showers and thunderstorms can be expected again late this evening and into the overnight hours.

2) A drier and somewhat cooler airmass will move in behind the cold front for Friday afternoon and into Saturday. A secondary cold front will bring additional showers and thunderstorms on Sunday along with cooler temperatures for early next week.

DISCUSSION

KEY MESSAGE 1) The remnants of a MCS are moving east across the area early this afternoon. Some low and mid level clouds have been observed along with a brief wind shift. While the old MCS itself will not produce any rainfall, subtle areas of convergence and differential heating could lead to storm development later this afternoon when the PBL destabilizes. Locally heavy rain and gusty winds are the main threat with any isolated storms this afternoon in the moist environment.

Later this evening, another decaying MCS moves in from the northwest well ahead of an approaching cold front. Showers and storms are once again possible, especially along and northwest of I-71. There does appear to be at least some damaging wind potential if the MCS holds together due to increasing shear and high DCAPE values across eastern Indiana and western Ohio this evening/overnight.

In terms of heat, some cloud cover has initially limited temperatures today as the cloud debris from an old MCS has moved overhead. These clouds progress to the east this afternoon and should give way to some more sunshine. Combined temperatures in the upper 80s with dew points in the lower 70s should support heat index values in the upper 90s to near 100 well into the afternoon.

KEY MESSAGE 2) A cold front associated with a low in Canada pushes east through the region on Friday morning. Drier and slightly cooler air moves into the Ohio Valley behind the front. High pressure progresses across the area on Saturday bringing dry conditions and near average temperatures.

Shower and storm chances increase once again on Sunday when another cold front associated with a low far to the north in Canada moves through. There could be a window for severe weather as some models are depicting instability overlapping with increasing shear ahead of the front during the day on Sunday. The best potential for storms appears to be in the southeast where frontal passage occurs later in the day.

Cooler and drier air arrives for the start of next week behind the front.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

VFR conditions featuring some cumulus growth is likely through the afternoon and early evening. Some isolated showers and storms are possible this afternoon, but probability of occurrence at the TAF sites is too low to include at this time. Later this evening/overnight, a decaying MCS moves in from the northwest and supports shower and storms potential at KDAY and the Cincinnati sites. The system continues to decay as it moves toward KILN and the Columbus sites overnight which should limit potential impacts mainly some brief MVFR ceilings. After 1400z, VFR conditions are likely to persist across all the TAF sites.

Southwesterly winds persist through about 1200z Friday. It should be noted that brief wind shifts are possible when the remnants of the aforementioned MCS moves into the area tonight. After 1200z, a cold front pushes through the area switching winds to the northwest by Friday afternoon. A period of wind shear is expected tonight.

OUTLOOK... Thunderstorms possible Sunday.

ILN WATCHES/WARNINGS/ADVISORIES

OH...Heat Advisory until 8 PM EDT this evening for OHZ026-034-035. KY...None. IN...None.