textproduct: Wilmington

WHAT HAS CHANGED

No significant change to the forecast.

KEY MESSAGES

1) High confidence of extreme heat through Friday.

2) Chances for showers and thunderstorms increase over the holiday weekend, while heat and humidity continues.

DISCUSSION

KEY MESSAGE 1)

Mid-level high continues to persist over the Ohio Valley today. The high will begin to weaken Friday into Saturday, but with little change in air mass, have continued with the current heat headlines through Friday.

KEY MESSAGE 2) As the ridge weakens, it is possible a thunderstorm complex could make its way into our northern and western counties late Friday afternoon into the evening. With strong instability and model DCAPE near 1,600 J/kg (based on 12Z HRRR), downburst damaging winds are the primary threat. By Saturday, residual boundaries from late Friday convection could provide enough focus for additional storms to develop. Most guidance shows an increase in coverage. For this reason, have opted to keep heat headlines ending Friday evening for now. Will monitor updated guidance moving forward and adjust as needed. Either way, most areas are likely to be hot and humid through July Fourth, so those planning outdoor activities should continue to plan for the heat.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

Mostly VFR forecast continues for the TAF sites. Winds will be rather light. Patchy early morning fog is expected in prone river valleys. Have added LUK fog early Friday morning based on persistence.

OUTLOOK...Thunderstorms are possible Friday and into next week.

ILN WATCHES/WARNINGS/ADVISORIES

OH...Extreme Heat Warning until 8 PM EDT Friday for OHZ026-034-035- 042>046-051>056-060>065-070>074-077>082-088. KY...Extreme Heat Warning until 8 PM EDT Friday for KYZ089>100. IN...Extreme Heat Warning until 8 PM EDT Friday for INZ050-058-059-066- 073>075-080.