textproduct: Wilmington

WHAT HAS CHANGED

Increased rainfall chances Friday morning and early afternoon across the west and southwest portions of the area.

In collaboration with surrounding offices and WPC, high temperatures for Sunday through Tuesday continue to be adjusted down from the NBM.

KEY MESSAGES

1) Temperatures remain below normal through Friday morning before transitioning to a warmer air mass Saturday. Above normal temperatures are forecast Sunday through Tuesday before a cold front moves in Tuesday or Wednesday.

2) Unsettled weather returns Friday and continues through the weekend with showers and thunderstorms occurring in the region. A warm front shifts north early next week, providing dry conditions. The next front moves in Tuesday or Wednesday, increasing the potential for thunderstorms.

DISCUSSION

KEY MESSAGE 1) Northwesterly winds continue to usher in cooler temperatures this afternoon and evening. Expect another chilly morning Friday as lower 40s occur area wide.

As the high pressure shifts southeast of the region Friday afternoon, southerly flow will support warmer temperatures, but some shower activity and cloud cover could greatly mitigate the overall warming. Adjustments to the temperature forecast will likely be required once confidence increases on the level of impact of the remnant activity moving in early Friday.

A period of warm and muggy conditions settles in Saturday into early Sunday. Temperature forecasts Saturday vary across the local area and will be dependent on lingering cloud cover leftover from Friday night & Saturday morning showers. Where sunshine occurs, temperatures comfortably rise back into the 80s.

The front lifts northward Sunday as a mid-level ridge builds over the eastern CONUS, paving the way for temperatures to rise into the mid to upper 80s and perhaps a few lower 90s. Similar conditions are forecast Monday ahead of an approaching cold front, but mostly sunny skies will allow for a few more observations in the lower 90s.

The timing of the next cold front sometime Tuesday or Wednesday presents some uncertainty regarding the temperature forecast for Tuesday. A faster front would reduce the temperatures on Tuesday, and a slower front supports the potential for another day in the mid to upper 80s and lower 90s.

The passage of the cold front Tuesday night or Wednesday results in cooler conditions Wednesday, although temperatures are still around seasonal normals with no strong influence from a cooler air mass.

KEY MESSAGE 2) Dry conditions remain in place over the area through tonight, however, a compact shortwave moving through the lower Midwest will lead to a cluster of thunderstorms west of the area overnight. This cluster struggles to maintain thunderstorms into Friday morning, but there is enough support from the suite of models to increase rainfall chances across eastern Indiana, southwest Ohio, and northern Kentucky into the early afternoon. Forecast soundings suggest the air mass ahead of this feature will be quite dry so some of this could end up as sprinkles as it weakens. Otherwise, the rest of the day looks dry.

Friday night, positive theta-e advection increases over the Ohio Valley, supporting the potential for elevated showers. Within the warm ascent region, another weak shortwave will eject eastward into the region. Forecast soundings indicate elevated instability so some rumbles of thunder are possible into Saturday morning.

Moving into Saturday afternoon and evening, a final shortwave moves through the region. Despite this renewed source of lift, the antecedent atmosphere over the area remains uncertain, primarily due to the potential for showers and lingering cloud cover left over from Saturday morning. This activity disrupts the ability for widespread warming, complicating the scenario for the afternoon and evening. Finding uncontaminated forecast soundings is quite a challenge depending on the model, however, there remains enough wind shear and potential for instability to pose a strong to severe thunderstorm threat. With the lack of strong wind shear and modest height falls, the ceiling for the severe threat is likely to remain low, even if confidence increases in more widespread instability. Scattered thunderstorms capable of damaging wind gusts or quarter sized hail would be the main themes for the day. PWATs are anomalous, but given the lower potential for deep thunderstorms, any locally heavy rain threat would exist in places where multiple rounds of thunderstorms occur.

The threat for scattered showers and thunderstorms continues into early Sunday before the front lifts northward. Then, attention shifts to the next cold front arriving Tuesday or Tuesday night. Confidence is high that the best forcing will be north of the region, so while thunderstorms are certainly possible, the severe weather threat appears low given the overall scenario. Latest longer-range severe weather tools remain unimpressed and hold to lower probabilities.

With the main trough shifting north of the region through the upper Great Lakes, the exact timing of the front is still uncertain. This spread in the guidance means chances for rain are in the forecast Tuesday through Thursday.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

Residual cu will gradually dissipate this evening. Some mid and high clouds will start to work into the region late in the overnight and into the day on Friday. Before they do, there will be the potential for some river valley fog overnight at KLUK. Some additional VFR cu will be possible on Friday in some areas. There will be some showers that will be dissipating as they encounter dry air over the area during the day on Friday. Have a tempo shra in at KCVG and KLUK for a couple of hours during the day on Friday. Any precipitation is expected to be light.

OUTLOOK...Thunderstorms are possible Friday night through Saturday night and then again on Tuesday.

ILN WATCHES/WARNINGS/ADVISORIES

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