textproduct: Wilmington

WHAT HAS CHANGED

No major changes to the key messages as snow potential continues to decrease this weekend. Added a mention of fog in the warm temperatures section.

KEY MESSAGES

1) Temperatures above normal through Friday. Record warm minimum temperatures and a few record high temperatures remain possible. Areas of fog possible tonight into Thursday morning.

2) Chances for showers and thunderstorms Thursday and Thursday night. Scattered severe thunderstorms are possible. Gusty winds occur Friday behind a cold front.

3) Below normal temperatures early next week.

DISCUSSION

KEY MESSAGE 1) Temperatures above normal through Friday. Record warm minimum temperatures and a few record high temperatures remain possible.

With strong southwesterly surface flow providing a steady flow of warm air today, record warm minimum temperatures are likely to be met at CVG and DAY today. Record high temperatures are still possible but may fall a few degrees short. The stretch of warm air continues into Thursday and early Friday with additional records possible.

Fog: With the warm moist air over the region, the potential for fog development is favored again late this evening into Thursday morning. Dense fog is possible and may impact the Thursday morning commute before clearing.

KEY MESSAGE 2) Chances for showers and thunderstorms Thursday and Thursday night. Scattered severe thunderstorms are possible. Gusty winds occur Friday behind a cold front.

Severe weather summary: Low pressure advancing eastward through the central Plains tonight moves into the Mississippi River Valley tomorrow afternoon. The shortwave pivots northeastward into the Great Lakes during the evening hours, amplifying mid-level flow over the Ohio Valley. This will push a warm front through the area, with showers and scattered thunderstorms developing west of the area during the afternoon. Given the expected placement of the low pressure and the associated warm front, some of these storms may occur within an atmosphere capable of producing severe weather. For now, the threats include small hail, damaging winds, and isolated tornadoes with the primary threat occurring between 5pm and 10pm.

Details: Upper level diffluence will support broad ascent, but the lack of height falls may limit the overall coverage of storms as they develop. Most of the CAMs that develop thunderstorms begin the process earlier in the afternoon across Illinois and Indiana. These storms then move into the area over the next few hours. The environment across the local area will consist of CAPE around 250-750 J/kg and effective bulk shear around 60 knots. Southeasterly surface blow results in curved hodographs, supporting the potential for rotating updrafts. Large hail potential may be limited due to the lack of deep/steep mid-level lapse rates, but some hail should be expected with any organized thunderstorm. Damaging wind and isolated tornadoes cannot be ruled out given these background parameters.

There are some failure modes, which is why this severe threat remains very conditional. Even if thunderstorms form, the best instability may only exist for a few hours before trends decrease into the evening hours. Additionally, if updrafts remain aloft, the potential for tornadoes decreases. So while severe weather parameters and curved hodographs rightly provide concern for local severe weather impacts, this occurrence of severe weather may end up very isolated within the broader area of SPC Slight/Marginal risk.

Breezy on Friday: As the cold front moves through during the day Friday, the surface low pressure (sub 990 mb) to the northwest provides an opportunity for effective mixing of stronger winds aloft to the surface. Area wide, wind gusts of 25 to 35 mph are expected, especially across eastern Indiana, western and central Ohio. Across our windier areas, regular gusts of 35 to 40 mph wind gusts are possible.

KEY MESSAGE 3) Below normal temperatures early next week.

While the potential for an east coast low pressure continues to increase, confidence is trending toward lower chances for light snowfall accumulations across the local area. Instead, northwesterly cyclonic flow Sunday into Monday supports snow showers and flurries. Can't rule out some light accumulations, but overall, this potential has decreased.

As the trough digs into the northeast US, a period of below normal temperatures will then occur into early next week. The coldest period will be Monday into Monday night, as temperatures struggle to reach above freezing during the day, dropping into the teens overnight into Tuesday morning. Wind chill values in the single digits are possible Monday and Tuesday morning.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

MVFR CIGs linger of the area, but enough breaks have formed to allow for VFR conditions. Trends toward VFR continue into the evening hours. Winds gusting in the 20 to 25 knots range gradually relax into the evening hours, with winds becoming more southerly.

The one increasing concern is for the development of fog/low stratus after 05Z through 15Z Thursday. Mostly clear skies will support radiational cooling with light southerly flow continuing to bring in warm/moist air from the south.

MVFR restrictions continue throughout the day ahead of the showers and thunderstorms after 18Z.

OUTLOOK...MVFR ceilings and thunderstorms are possible Thurs night. Gusts to 25-35kt behind a cold frontal passage early Friday.

ILN WATCHES/WARNINGS/ADVISORIES

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