textproduct: Wilmington

WHAT HAS CHANGED

No significant changes from previous forecast.

KEY MESSAGES

1) A few showers possible this afternoon into this evening with a chance for showers and thunderstorms across the south late tonight into early Monday. The threat for a strong to severe storms possible late Monday afternoon into Monday evening.

2) An unsettled weather pattern will develop bringing an increased threat for precipitation, peaking on Tuesday into Wednesday. Once the midweek system exits the region, scattered showers will linger, along with cooler than normal temperatures through next weekend.

DISCUSSION

KEY MESSAGE 1) A weak shortwave embedded in the northwest-west flow aloft to move across the area late in the day thru this evening. Expect clouds to increase and a few light rain showers developing into eastern Indiana and western Ohio late in the day. Low levels remain dry and as this shower activity tracks further east expect a general decrease in coverage. Any rainfall that occurs will be very light. Moisture begins to increase and marginal elevated instability develops late tonight into ILN/s southwest at the nose of a 40-45kt 8H jet. This will lead to scattered showers and embedded thunder across ILN/s southwest counties - which then tracking across the far south before diminishing after sunrise. Expect a low in pcpn activity mid morning into the mid afternoon hours.

Mid level flow becomes more zonal with a southwesterly 8H jet of 40-45kt jet advecting favorable moisture northward later Monday afternoon into Monday night. Although moisture increases the forcing appears to be rather diffuse and weak. Model solutions - especially the CAM/s solutions differ given the weak forcing. Given low end moderate 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 wind. The favored location for storms will be along and north of I-70.

KEY MESSAGE 2) Zonal mid level backs more southwesterly as a shortwave trof digs south from south central Canada into the Great Lakes at midweek. A surface front which moves into ILN/s area Tuesday afternoon slows down as waves of weak low pressure ripple northeast along this boundary. This will allow for the a period of unsettled weather to develop. Showers and scattered thunderstorms are possible through Thursday. The most favored rain potential is late Tuesday into Wednesday when a frontal boundary stretched across the region serves as a focal area for a waves of low pressure, along with increasing low level moisture.

Ensemble probabilities of > 1" of rain ramp up to 80 percent or more especially in the tri state, with a 20-30% chance of 2" of rain from Tuesday through early Wednesday. PWATs reach 150-160% of normal for early May. Will have to monitor for the potential for small stream flooding, though with the seasonal transition into early May, 1-2" over 24 hours may not pose an issue. Will have increased confidence on amounts and totals with this system as it comes into the range of the CAMs.

Amplified mid level flow pattern with mid level trof across the eastern CONUS leading to continued northwest flow and below normal temperatures from Wednesday into next weekend.

AVIATION /00Z MONDAY THROUGH FRIDAY/

Mid clouds will prevail across the region through the first part of the TAF period. Showers passing near the Cincinnati terminals could eventually makes their way across those sites with brief reductions in visibility possible. There may be some lower clouds across the area towards 12Z. Probability of that producing an MVFR ceiling is greatest in the Columbus area, and even there that chance is too low to include in the TAFs at this point.

Cumulus will develop during the day with winds increasing and gusting over 20 kt once again. There is a chance of thunderstorms late in the period. 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.