textproduct: Wilmington

WHAT HAS CHANGED

No significant changes from previous forecast.

KEY MESSAGES

1) A few residual showers mainly across the south pivot north with additional storms developing late in the day into this evening mainly north of I-70. Locally strong thunderstorms are possible with the late afternoon and evening evening storms.

2) The chance for showers and thunderstorms continues through Wednesday, with scattered showers and cooler conditions expected during the late week.

DISCUSSION

KEY MESSAGE 1)

A few residual showers mainly across the south pivot north with additional storms developing late in the day into this evening mainly north of I-70. Mid level flow becomes more zonal with a developing southwesterly 8H jet of 45-50kt jet advecting the favorable moisture northward later this afternoon into tonight. Although moisture increases the forcing appears to be rather diffuse and weak.

Model solutions show considerable differences given the weak forcing. SBCAPE value are expected around 1000 J/KG by late aftn. Given instability and some dry air aloft - can not rule out the potential for a strong storm during the later afternoon hours into the evening with the main threat being strong to damaging winds.

KEY MESSAGE 2)

A shortwave trough digs into the Midwest and Great Lakes Tuesday into Wednesday. At the surface, a cold front moves south into the CWA on Tuesday, gradually moving through Tuesday night into Wednesday. The front slows down as waves of weak low pressure ripple northeast along this boundary Tuesday night. This will allow for the a period of unsettled weather to develop. Showers and scattered thunderstorms are possible through Thursday. Ensemble probabilities of > 1" of rain ramp up to 80 percent or more especially across southeast Indiana and southwest Ohio, with a 20-30% chance of 2" or more of rainfall from Tuesday through early Wednesday. Most solutions produce a 1 to 2 inch rainfall, with a trend slightly lower in the past 24 hours. Will continue to monitor for the potential for small stream flooding, though with the seasonal transition into early May, 1-2" rainfall over 24 hours may not pose an issue.

Although the surface cold front settles south of the area by late Wednesday, influence from the mid level trough will keep unsettled conditions (showers) in the forecast through the rest of the week, along with below normal temperatures.

AVIATION /12Z MONDAY THROUGH FRIDAY/

Mid level flow becomes more zonal with a developing southwesterly 8H jet of 45-50kt jet advecting favorable moisture northward later this afternoon into tonight. Although moisture increases the forcing appears to be rather diffuse and weak. Model solutions show considerable differences given the weak forcing - so confidence in exact timing and location is low. There may be a passing shower from a VFR deck across the southern TAF sites as the moisture shifts north. At this time the best coverage of storms looks to occur at KDAY and KILN. Confidence further east toward Columbus during the evening is lower so have a PROB30 mention until 02Z.

VFR conditions drop to MVFR Tuesday afternoon with a period of IFR possible. Have showers and thunderstorms developing late in the TAF period as the front approaches from the west.

Southerly winds are expected to become gusty this afternoon, and may remain gusty at or above 20 knots this evening. Non-convective low level wind shear may also develop this evening into the overnight hours.

OUTLOOK...Thunderstorms possible Tuesday afternoon into Tuesday night. MVFR to IFR ceilings and visibilities likely Tuesday night into Wednesday.

ILN WATCHES/WARNINGS/ADVISORIES

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