textproduct: Wilmington

WHAT HAS CHANGED

Potential for thunderstorms late this week, with at least some chance of hazardous weather, and signs of building heat for early next week.

KEY MESSAGES

1) Below-normal temperatures expected through this week.

2) Showers and thunderstorms expected at times from Thursday night through Saturday.

3) Temperatures increasing going into early next week.

DISCUSSION

KEY MESSAGE 1) Below-normal temperatures expected through this week.

Behind a cold front, northerly flow will persist across the region today, with a broad area of high pressure moving into the Great Lakes. This high will bring a relatively dry and cool air mass to the region, marking the start of a few days with temperatures below normal for late June. Both Tuesday and Wednesday will remain dry, with no chance of precipitation, and surface dewpoints only in the mid 50s.

By Wednesday night, the surface high will be moving off to the east, and the overall weather pattern will be switching to one with a southerly component to the flow below 850mb. This will bring an increase in theta-e to the region, and possibly even some precipitation to the northern parts of the forecast area early Thursday morning.

KEY MESSAGE 2) Showers and thunderstorms expected at times from Thursday night through Saturday.

Although temperatures will remain below normal for Thu-Fri-Sat, moisture will be on the increase, with dewpoints getting into the 60s -- perhaps near 70 in the southern sections of the forecast area. Attention will then turn to the west, as one or several shortwaves in the pseudo-zonal flow move out of the middle Mississippi Valley region and into the Ohio Valley. The first wave may arrive late Thursday into early Friday, with showers and thunderstorms expected, and additional storms possible through Saturday if more forcing arrives. It does look like a surface frontal zone will remain somewhere in the vicinity of the ILN CWA through this time frame, providing some convergence and a gradient in temperatures that may be a focus for storm development.

Though details are still far from worked out, there does appear to be some potential for hazardous weather during the Thu-Fri-Sat time frame, with Friday appearing the most likely day at this point. Neither instability or shear look higher-end, so it remains to be seen when either (or both) might be maximized over the area. Some models are depicting a surface low moving through the region -- if that occurred, it could increase both forcing and low-level shear, and possibly increase the severe threat as a result. This kind of weather pattern is also one that would support repeated rounds of convection over the same general areas, so flooding may be possible too. Still a long way from any certainty on this, but at least some severe or flood potential could occur late this week.

KEY MESSAGE 3) Temperatures increasing going into early next week.

Precipitation chances will be diminishing by the second half of the weekend, with a big pattern change forecast to take place. Ridging is forecast to build through the eastern CONUS, putting the Ohio Valley in an air mass that will be increasingly hot and humid. Thus, the main concern for next week will be the potential for heat to reach hazardous levels.

AVIATION /10Z TUESDAY THROUGH SATURDAY/

VFR conditions are expected through the TAF period, with scattered clouds passing through the region.

Northerly winds will increase today, with some gusts to around 20 knots during the daytime hours. Tonight, winds will back slightly to the northwest, and may go calm or variable for a brief period late tonight into early Wednesday morning.

OUTLOOK...Thunderstorms are possible at times from Thursday through Saturday.

ILN WATCHES/WARNINGS/ADVISORIES

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