textproduct: Wilmington

WHAT HAS CHANGED

Increased wind gusts this afternoon, with gusts of 35-40 MPH likely today. High temperatures will reach into the upper 70s to lower 80s today, nearing daily standing records.

KEY MESSAGES

1) Very breezy conditions are expected today, particularly during the afternoon. Gusts of 35 to 40 MPH are likely along and north of the I-71 corridor. Secure loose outdoors items. Additionally, temperatures will top out in the lower 80s this afternoon, approaching daily standing records.

2) A warmer and more active weather pattern will develop this evening and continue through most of the week, with several rounds of showers and storms expected from midweek into the upcoming weekend.

DISCUSSION

KEY MESSAGE 1)

Flow has become more zonal across the region as a weak S/W pivots E through the nrn OH Vly into the Great Lakes region, with a sfc wave ejecting E through these areas by this afternoon. This will place the ILN FA squarely in an expanding warm sector, with a tight pressure gradient on the SE flank. This will lead to breezy conditions amidst diurnally-enhanced mixing, especially this afternoon. An H8 LLJ on the order of about 35kts will develop from SW to NE through the OH Vly during the day Tuesday, particularly from IL/IN into nrn OH. Although the vertical mixing won't be particularly deep, we should be able to mix down 30-35kt winds near/NW of the I-71 corridor Tuesday afternoon.

Although there will be some SCT/BKN Cu to contend with, temperatures should top out in the upper 70s to lower 80s across most of the local area this afternoon. The daily standing records for March 31 are 84 at KCVG, 83 at KCMH, and 82 at KDAY.

KEY MESSAGE 2)

An active weather pattern will develop beginning as early as this afternoon as convection initially N/W of the local area drifts to the ESE very close to (or perhaps into) the nrn parts of the local area between 20z-02z. There are uncertainties regarding exactly how far S/E this activity will make it as the storms /may/ initiate along a remnant outflow boundary, which will migrate into central IN around 18z. However, if a stronger outflow is able to be maintained into central IN, there could be enough LL convergence (with SW sfc flow) alongside diurnally-enhanced SB-instby to initiate one or more miniature line segments along the leading edge of the outflow. This (very conditional) threat would evolve E into the local area, primarily for areas near/N of the OH Rvr past about 20z. This conditional severe threat would be favored particularly near/north of a line from near Wayne Co IN to Darke Co to Licking Co OH from mid afternoon into early evening. The primary threat with this activity would be a /very/ isolated strong/damaging wind threat (with steep/deep LL lapse rates and sufficient SB-instby supporting gusty winds) and small hail. The materialization of this localized severe threat, however, is far from certain, with the potential for this activity to either miss the local area to the N altogether or be on a slow weakening trend (i.e. sub-severe) as it drifts SE into the local area, especially as it gets closer to central OH by early evening.

No matter how the setup mid afternoon into early evening evolves, shower/storm coverage will increase into parts of WC and central OH by and after midnight, slowly sagging southward into the predawn hours. The environment with southward extent overnight will become increasingly unfavorable for strong/severe storms, so do think that if -- and it is a big if -- a very localized/brief severe threat is to evolve locally today, it would be with the activity discussed above from mid afternoon into early evening.

The front will slowly drift to the S into the local area late tonight into Wednesday morning. Most areas S of I-70 will likely stay dry into early Wednesday morning, with decreasing disorganized convection lingering in the NW third of the local area by daybreak Wednesday.

By Wednesday afternoon/evening, digging S/W energy into the central plains will promote height rises downstream into the OH/TN Vlys. This will allow the LL front to stall during the daytime Wednesday. Although there will be some LL convergence along the front (which will be draped squarely across the heart of the local area by midday), the focus for lift will be fairly weak, with disorganized ISO/SCT showers/storms between the OH Rvr and I-70 by mid/late afternoon into the evening. Pcpn chances/amounts will be highest in the N/NW third of the ILN FA from this evening through Wednesday night, even with some ISO/SCT showers/storms during the day Wednesday across central/southern parts of the local area.

The more-amplified S/W will pivot into the OH Vly Thursday night into early Friday, with downstream ridging expanding in response to the approach of this feature. Shower/storm activity will likely increase into far wrn parts of the local area Thursday night into early Friday, with the system gradually being forced over the crest of the ridge into the Great Lakes region. This suggests that the forcing should decrease a bit later into the night, so there are uncertainties regarding the maintenance of convective coverage/intensity further E into the local area into Friday morning. The best chance for showers/storms Thursday night will be near/W of I-71.

Another system will impact the region Saturday into Saturday night before drier conditions return by Sunday. At this juncture, it seems the best potential for widespread 1-2+" of rain from this evening through this weekend will be centered across NW parts of the local area, but there are still quite a few details to be determined regarding the evolution of the several rounds of convection during this stretch. Any prolonged PW anomaly of 200+% with a parade of S/Ws through this moisture-rich environment is cause for at least some concern, especially after a fairly wet March (rainfall 150%-200% of normal) across most of the local area. So certainly some localized/brief flooding potential may evolve late week into this weekend, owing to the repeated rounds of showers/storms (even with the relatively- progressive nature of the individual systems).

As the weather undergoes a pattern change, above normal temps are likely midweek and beyond, with highs in the 70s and lows in the 50s for most of the week. Some 80s are possible today, Thursday, Friday, and Saturday.

AVIATION /09Z TUESDAY THROUGH SATURDAY/

VFR conditions are expected to continue through the period, with coverage of VFR Cu increasing into the daytime. SW sfc winds around 12-15kts will increase to around 20kts, with gusts around 30-35kts, past 15z. The winds will subside a bit past 00z, but will stay up at around 5-10kts into Wednesday morning.

There is a conditional potential that some SHRA/TSRA may get close to, or impact, KDAY/KCMH/KLCK between about 20z-02z, with greater coverage of SHRA and ISO TSRA working into these areas toward the predawn hours Wednesday morning. PROB30 has been added for the afternoon/evening potential, with more widespread SHRA (and ISO TS) after about 08z or so. The pcpn may hold off until after 12z for KILN/KCVG/KLUK.

OUTLOOK...Periodic thunderstorms are possible Wednesday through Saturday. MVFR conditions are possible at times Wednesday through Saturday.

ILN WATCHES/WARNINGS/ADVISORIES

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