textproduct: Wilmington

WHAT HAS CHANGED

The severe risk has increased for this afternoon.

KEY MESSAGES

1) A cold front continues to move through this afternoon bringing showers and thunderstorms. Some storms could become severe.

2) Cooler Temperatures to start the week.

3) Showers, thunderstorms, and gusty winds Wednesday and Thursday when a strong low is expected to move through the Great Lakes.

DISCUSSION

KEY MESSAGE 1)

A cold front progresses through the area this afternoon. Showers and thunderstorms move in northwest of Dayton after 1pm and progress through the Scioto River Valley by approximately 9pm tonight. MLCAPE values near 1000 J/kg and effective shear approaching 30 knots could support some stronger storms especially along and southeast of I-71. Straight line hodographs, slim CAPE profiles (weak updrafts), and weak low level shear implies damaging winds are the main threat in the strongest storms. While a few storms are possible further ahead of the front, most storm coverage is expected to be on a line just southeast of the boundary.

After 9pm, winds shift to the northwest behind the front advecting cooler, drier air into the area thereby ending the severe threat.

KEY MESSAGE 2)

High pressure builds in behind a cold front tonight and moves across the region on Monday and Tuesday. Dry conditions and below average temperatures accompany the surface high through at least Tuesday morning. By Tuesday afternoon, winds shift back to the south behind the high on Tuesday as a low fills to the northwest. Showers and thunderstorms are possible by Tuesday night when a warm front lifts into the Ohio Valley.

KEY MESSAGE 3)

Medium range global ensemble guidance continues to show an anomalously deep surface low moving through the Great Lakes on Wednesday and Thursday. Robust upper level winds accompany this surface low.

Although the exact details are still not resolved, the most likely scenario involves a warm front lifting through the Ohio Valley on Wednesday or Wednesday night followed by a cold front on Thursday. Strong wind shear is likely and at least some instability looks probable along with anomalously high PWATs. If conditions do end coming together, multiple periods of severe weather are possible as highlighted by SPC extended range outlook. Flooding potential exists as well as mentioned in the WPC slight risk in the extended timeframe. Timing and placement of the low across the lakes will have a large impact on the forecast as the timeframe draws closer. Regardless of storm potential, gusty winds are likely on Thursday.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

A cold front moves through the area this afternoon. Ahead of the front, MVFR ceilings are likely along with scattered showers and thunderstorms. Southwesterly winds persist ahead of the front.

MVFR ceilings and scattered storm move east with the cold front this evening. Winds shift to the northwest after FROPA. VFR conditions are expected after FROPA.

OUTLOOK... Thunderstorms and gusty winds possible Wednesday and Thursday.

ILN WATCHES/WARNINGS/ADVISORIES

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