textproduct: Wilmington

WHAT HAS CHANGED

Nothing significant. Honing in on Saturday night frontal passage and timing of showers/thunderstorms. Also becoming more confident in warm air ahead of the front and record high mins Friday night/Saturday morning.

KEY MESSAGES

1) Warm, humid, and breezy conditions with scattered showers and some thunderstorms through Saturday.

2) Cold front crosses Saturday night and changes wx pattern to cool and dry through the remainder of the forecast.

3) Temperatures approach freezing mark Monday night and stand a better chance to drop below freezing Tuesday night.

DISCUSSION

KEY MESSAGE 1) Max temps Friday and Saturday are forecast to be within 2-3 deg of record highs. Min temps Friday night are forecast to be 2-5 deg above record high mins. This forecast seems pretty solid as a warm front will be moving ne and winds will pick up overnight.

Mean trough centered over the Plains states will keep a deep southwest flow over the Ohio Valley. Surface winds will be breezy through Saturday, maxing out on Saturday afternoon as the cold front increases the pressure gradient ahead of it. Overnight winds tonight will maintain at least a 10-15 mph speed which is diurnally anomalous. Winds back off Friday evening to under 8 mph, but then pick back up overnight. This is due to a remnant cold front in northern OH during the day weakening as it dips toward the I-70 corridor, evolving into a warm front that moves northeast overnight.

Cold front washes out tonight north of CWA, with scattered shower activity expected through Friday as temps aloft approach dewpoints at various levels. Sat will be dry as warm air mixes out any humidity through a deep layer.

KEY MESSAGE 2) A cold front will move east across the region Saturday night, bringing with it a line of showers and thunderstorms. These storms will likely begin in the late day for the northwestern 1/3 of the CWA, and progress fairly rapidly to reach the southeast CWA a little after midnight. Rain will have ended in the northwest towards midnight, and in the southeast a few hours before daybreak.

Behind this front, a change in the airmass will bring dry and cool weather to the region for the remainder of the forecast period.

KEY MESSAGE 3) Colder weather pattern next week will bring a chance of frost Monday and Tuesday morning and a freeze potential for Wednesday morning. Earlier discussion noted winds lower confidence on these temps materializing. ATTM, light winds are noted Sunday and Monday nights, which will support frost in low lying areas, but not likely area- wide. Tuesday night there will be some wind 5-10 mph, but will becoming from almost due north and temps for this time will be purely advection based.

To further bolster Wednesday morning lows below freezing, the NBM 10th and 90th percentiles have a 6-7 deg spread and operational low trends closer to the cold side. The 5th/95th percentiles open this range by a bit, slightly cooler by a degree or two but warmer by 3-4 degrees. As the operational forecast remains unchanged, this supports the argument for leaning to the colder solution.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

Sustained winds overnight 10-12kt with gusts 20kt. Some LLWS could be present as 50kt jet lowers to 2kft. Scattered showers are possible overnight as s/w energy outpaces the cold front that is dying out northwest of Ohio. Did not hit these hard at all as the scattered nature makes for nebulous placing/timing. At the tail end of the CVG forecast, showers look to be more likely. The cold front washes out north of the CWA but moisture is expected to pool underneath an inversion, fed by a continued warm and moist sw wind. Cigs also look to drop to MVFR at this time.

OUTLOOK...Periodic showers with MVFR conditions are possible Friday, and likely Saturday night behind a line of thunderstorms coincident with a frontal passage.

ILN WATCHES/WARNINGS/ADVISORIES

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