textproduct: Wilmington

WHAT HAS CHANGED

Added mention for precipitation chances mid-week.

KEY MESSAGES

1) Widespread precipitation is expected this evening into Monday, with a chance of heavy rain and a few strong storms.

2) Below normal temperatures are expected this week. Next chance for rain will arrive mid-week.

DISCUSSION

KEY MESSAGE 1) Low pressure system will travel through the Midwest region, leading to increased cloud coverage today and chances for showers/storms beginning late this evening.

Confidence remains high on an MCS blowing through our fa tonight. CAMs have continued to trend slightly later with the onset of convection in our western CWA, now arriving in our southeast IN counties between 8-10 PM. The leading edge of this complex is where the severe threat would be the highest. CAPE still remains a limiting factor, with the highest values near 500 J/kg in the Tristate region. The thermodynamics are certainly a limiting factor with the severe threat, but keep in mind that the kinematics are very strong. Effective shear values near 50-60 kts with help with MCS maintenance and keep a risk for damaging straight-line winds reaching the surface. However, these pockets of damaging winds are expected to be isolated. Wind profiles do show a lot of veering in the lowest levels, which would support the risk of a spin-up tornado. Similar to the straight-line wind threat, the area most at risk of a brief tornado would be near the Tristate, but cannot rule out a risk farther east near/south of the Ohio River. The severe threat should diminish once the leading edge of the MCS passes, which should be out of our CWA by 3-4 AM.

Given the trend in CAMs to show a more progressive MCS tonight, the risk for any flooding will be limited, even with the wet antecedent soil conditions. If a segment of the MCS is more oriented W-E, this would certainly increase the risk for flood or flash flood potential given the longer period of convection.

The low pressure center will still be slowly tracking through our fa on Monday. This will initiate some isolated showers during the daytime, especially along the I-70 corridor near the center of the low. The cold front will still be in our far southeastern counties during the late morning and early afternoon hours, which could initiate some convection in portions of north-central KY and southern OH during this timeframe. Given the continued favorable wind shear, cannot rule out a strong to severe storm tomorrow before the front pushes east.

KEY MESSAGE 2) Normal high temperatures for this time of the year are generally around 85 degrees. For the majority of this upcoming week, daytime highs are expected to remain below this value. In fact, several locations will only observe daytime highs in the mid to upper 70s through mid-week, but a slight warming trend ensues through the end of the work week, brining highs back into the 80s.

There is a chance for showers/storms Wednesday night into Thursday as a shortwave ripples through the Midwest region. Still early to get into all the details, but this will be the next best chance for pcpn after the system moves through tonight into Monday.

AVIATION /16Z SUNDAY THROUGH THURSDAY/

Complex of showers/storms expected late this evening. For majority of our terminals, modified the PROB30 groups to TEMPOs for TSRA potential, with similar timing from the 12z TAF. Maintained PROB30 at KCMH/KLCK as thunder potential remains lower there.

MVFR CIGs expected to build in behind the heaviest rainfall. Some IFR CIGs also possible, primarily after daybreak Monday. With the low pressure center slow to move through, some isolated showers remain possible through most of the morning hours Monday.

Southerly winds increase tonight, with sustained winds of 10-15 kts. Winds will veer to the southwest Monday morning and remain around 10-15 kts with isolated gusts of 20 kts.

OUTLOOK...Thunderstorms are possible again on Thursday.

ILN WATCHES/WARNINGS/ADVISORIES

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