textproduct: Wilmington

WHAT HAS CHANGED

Flood Watch continues through the early afternoon today. Provided more details on severe potential for later today/tonight.

KEY MESSAGES

1) Flood Watch continues through the early afternoon today. After a break in the rain activity this afternoon, showers and storms build back into the region this evening, with some strong storms possible.

2) Seasonably warm and wet conditions continue through the weekend. This will result in continued development of showers and thunderstorms, increasing the potential for areal and river flooding.

DISCUSSION

KEY MESSAGE 1)

Axis of moderate to heavy rainfall shifting south towards the Tristate and areas near the Ohio River this morning. A large swath of 1.0-2.5" of QPE have been observed the past 24hrs, with the highest footprint in SE Indiana into potions of the Tristate. This will be the area where flood risk will likely be the highest given the upstream showers that are on a trajectory for these counties. This will result in several locations near the Tristate exceeding 3" of rainfall by the time the rain ends later this morning.

Already beginning to observe a response in some of the rivers as well, with multiple points forecast to reach minor flood stage. The basins currently getting hit the hardest with rainfall include the Great Miami, Little Miami, as well as lower Scioto. Smaller streams and tributaries near these locations also at risk of flooding in the near term. Will continue to monitor trends with the Ohio River as multiple points are now forecast to go to action stage later this week with the repeated rounds of rainfall.

It does appear that CAMs try to suppress the shower activity in our CWA by the mid to late morning hours today, giving a brief reprieve from the heavier rainfall. However, additional activity will fire up again this evening along the stalled boundary. Several CAMs favor a 5-7PM window for storms developing in our western counties first, increasing in coverage the next few hours. Bufkit soundings continue to suggest that this convection should remain elevated. Most of the thermal profiles are at least isothermal during the evening hours, with an inversion then quickly developing and persisting overnight. This should help limit the severe potential overall. There will be some decent mid level lapse rates near 7-7.5 C/km reaching the Tristate and southern OH in the evening, which could help with some larger hail growth. However, given the deep, saturated layer and increasing FZL height, severe hail threat should be very limited. Similarly, severe winds appear unlikely given deeper saturation limiting the ability for stronger winds aloft to mix down, but certainly cannot rule out some enhanced wind gusts in these storms this evening into tonight.

KEY MESSAGE 2)

Synoptic pattern will keep a tropical air mass in place through this weekend. PWAT anomalies will continue to peak at 2-3x above normal values for this time of year, highlighting the abnormally high moisture content.

Several more rounds of showers and storms expected tonight into Thursday as a robust shortwave swings through the Midwest region. A LLJ will also develop tonight, fueling the environment to help increase shower/storm activity during the overnight period. The shortwave will then swing through during the daytime hours Thursday, keeping numerous showers and storms around through the morning and afternoon. This will likely result in another slug of QPF amounts exceeding 1" for most, with some locations observing another 2-3" in this 24hr period. Given the wet antecedent soils, this will begin to increase the risk for flash flooding, with continued river rises as well.

Precip activity will gradually diminish Thursday night into Friday, with a relative lull in activity during this time period. A cold front will eventually swing through the Ohio Valley on Saturday, once again providing another good slug of rainfall. Finally, a larger break in pcpn is expected Sunday into Monday, but we may see increasing chances again by mid-week.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

Light rain will continue for a few hours this morning, primarily at KCVG/KLUK and KILN. Elsewhere, rain is light or scattered enough to not warrant a mention. All terminals expected to have a several hour break in the rain from late morning through mid afternoon. Some isolated showers may begin to develop by the late afternoon before a larger complex of showers and storms moves in from the west. These storms will continue into the overnight period before another brief lull in precip ensues during the late night period. However, another large complex of showers and storms will move back in near daybreak Thursday with strong upper level forcing moving through.

CIGs remain IFR/LIFR through majority of the period. Some pockets of MVFR might develop this afternoon, but confidence is too low to mention in the tafs.

Vsbys will remain quite variable, but some improvement to MVFR and perhaps even VFR possible into the afternoon. However, more reductions will occur with the onset of rainfall this evening.

Winds become more predominant out of the SE today, remaining below 10 kts. There will be a shift overnight to the SW. Highlight increasing winds and potential for 20 kt gusts in the extended KCVG taf.

OUTLOOK...MVFR/IFR conditions are expected through Thursday. MVFR/IFR conditions return on Saturday.

ILN WATCHES/WARNINGS/ADVISORIES

OH...Flood Watch until 1 PM EST this afternoon for OHZ060>064-070>074- 077>082-088. KY...Flood Watch until 1 PM EST this afternoon for KYZ089>100. IN...Flood Watch until 1 PM EST this afternoon for INZ050-058-059-066- 073>075-080.