textproduct: Wilmington

WHAT HAS CHANGED

No major changes.

KEY MESSAGES

1) A strong storm system will move through the region Tuesday night into Wednesday bringing the potential for severe weather, flooding, and gusty winds.

2) Low pressure will move through the Great Lakes during end of the week bringing the next chance of precipitation to the area, along with a period of gusty winds.

DISCUSSION

KEY MESSAGE 1) A strong storm system will move through the region Tuesday night into Wednesday bringing the potential for severe weather, flooding, and gusty winds.

Tuesday night severe threat: Confidence remains high that thunderstorms that had formed northwest of the area during the evening hours will gradually move eastward into northwest Ohio during the overnight. There will be some chance for this upscaled thunderstorm complex to shift southeastward into portions of western and central Ohio, but the organization should have decreased enough to limit severe potential. Any tornado threat would exist with this feature and not the elevated convection discussed next.

Additionally, a strong LLJ forming through the overnight hours will aid in the development of elevated thunderstorms with the most likely hazard being hail. Given the strong LLJ, the strongest storms may be capable of assisting these winds down to the surface.

Wednesday severe threat: By the morning, scattered thunderstorms and remnant clusters of rain are likely ongoing over the area with the front still located in northwest Ohio and central Indiana. Through the morning the front will work southeastward, with renewed thunderstorms developing ahead of and along the front. Depending on the amount of cloud cover, enough instability may form to support severe thunderstorms along and southeast of I-71. All hazards would be possible with these storms throughout the afternoon.

As the cold front moves through during the afternoon, enough instability should allow for thunderstorm develop with the front, even if instability is a bit lower. The enhancement of lift with the front would support thunderstorms capable of damaging wind gusts.

Wind threat: Ahead of the front, the strong LLJ will be able to mix downward to the surface more effectively during the late morning and afternoon hours, supporting a period of wind gusts between 35 and 40 mph. Some guidance suggests that advisory level wind gusts are possible.

Heavy rain/flooding: Locations that see thunderstorms Tuesday night and again on Wednesday will have the best chance of seeing locally higher rainfall amounts that would support renewed flooding potential. Given the southeast push with the cold front Wednesday afternoon, there will likely not be enough residence time with the thunderstorms to warrant an area wide flood watch.

2) Low pressure moving through the Great Lakes during end of the week brings the next chance of precipitation to the area, along with a period of gusty winds.

Another strong, compact low pressure system moves through the Great Lakes around the Friday timeframe. Although some mixed precipitation is possible, the main focus on Friday will likely be the stronger winds in the tight pressure gradient around the low.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

Low-level has gradually increased this morning, but with some delays on MVFR CIGs. Cannot rule out an isolated shower this morning and this afternoon but coverage did not warrant a mention in the TAF at this time. Continued the potential for IFR CIGs for temporary period in the first few hours of the TAF. MVFR/IFR cigs then lift into VFR conditions through the afternoon in continued low level southwest flow.

Strengthening southwesterly flow becomes more evident after 00Z Wednesday, with LLWS becoming likely by around 06Z. The strengthening jet supports the development of showers and eventually thunderstorms through the end of the TAF. These are currently advertised within PROB30 groups due to lower confidence in coverage at one particular site.

Thunderstorms will remain a possibility until the late afternoon on Wednesday so TEMPO groups will likely be needed throughout the 12-18 hour window. Outside the thunderstorm activity, wind gusts over 25 knots will become more frequent during the day on Wednesday, with some gusts between 30-35 knots.

OUTLOOK...MVFR to IFR ceilings possible through Thursday morning. Thunderstorms possible into Wednesday late afternoon before the cold front moves through. Sharp wind shift from southwest to northwest is expected between 20Z Wed-00Z Thu. Wind gusts above 40 kt possible Friday.

ILN WATCHES/WARNINGS/ADVISORIES

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