textproduct: Wilmington

SYNOPSIS

High pressure will remain across the region through Monday. Some showers will develop mid week ahead of a cold front. Unseasonably cool temperatures and dry conditions return late in the week after the frontal passage.

NEAR TERM /THROUGH TONIGHT/

A large surface high will remain centered north of the region keeping a light northeast flow across the area. With a dry airmass in place, there will be mainly sunny sky conditions except for a few flat diurnal cumulus clouds and some thin cirrus. Temperatures remain below normal with highs from the mid 70s north near 80 south of the Ohio River.

SHORT TERM /MONDAY/

A large area of high pressure will sprawl from the Great Lakes thru New England. The few diurnally driven cumulus clouds that develop will dissipate with the loss of heating leaving clear skies tonight. Lows overnight to drop to readings ranging from the upper 40s in rural protected locations to the lower 50s in urban areas.

Dry conditions to continue Monday with readings warming slightly under sunny sky conditions. Highs on Monday to range from the upper 70s to the lower 80s.

LONG TERM /MONDAY NIGHT THROUGH SATURDAY/

On Monday evening, a broad and weak upper low will be centered over Pennsylvania, with an overall pattern of upper troughing still in place across much of the eastern CONUS. Through the middle of the week, the pattern will become a little more amplified, with additional shortwaves moving through the Ohio Valley -- and an anomalous and well-defined upper low developing over the northern Great Lakes by Thursday evening. The main story through the extended forecast period will be the precipitation chances from Tuesday through Thursday, with another period of well-below-normal temperatures for the end of the week.

Going from Monday to Tuesday, the boundary layer flow over the Ohio Valley will generally switch from easterly to southwesterly. Although light, this will be enough to bring an increase in moisture to the region. As a weak shortwave begins to develop upstream, this may bring some showers to the southern portions of the forecast area as early as Tuesday afternoon. Rain looks more likely on Wednesday, as the shortwave becomes better defined, and moves east through the Ohio and Tennessee valley regions. There will be a break in the precipitation immediately behind this wave, but a cold front moving through the region some time early Thursday morning into Thursday afternoon will bring an additional chance for rain to the area. This front will be quite well-defined, with a much cooler and drier air mass coming into the region behind it.

It looks like there may be just enough instability for thunder on Wednesday (shortwave) and Thursday (ahead of the cold front) but the soundings do not look overly favorable for either strong storms or heavy rainfall. As of now, there are no concerns for hazardous weather with this system.

Behind the Thursday cold front, model spread becomes more significant with the eventual evolution of the upper low to the north. There are some solutions suggesting a secondary cold front could come through the Ohio Valley, and other solutions suggesting high pressure behind the Thursday front will keep conditions more tranquil through the weekend. For now, the forecast will be kept dry, as this seems the more likely scenario.

In terms of temperatures, Tuesday looks to be the warmest day of the extended forecast period, with highs in the upper 70s to lower 80s. Highs will decrease slightly on Wednesday, with precipitation expected, and then fall even further behind the cold front on Thursday (mid 60s to lower 70s). Temperatures are then expected to gradually increase from day to day through the weekend.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

Mostly clear skies will prevail this morning with only some thin high level clouds. Light winds and mostly clear skies may lead to very brief MVFR valley fog. Otherwise, expect only a few flat fair weather cumulus clouds across the region this afternoon. With the loss of daytime heating these clouds will dissipate this early evening. Light winds and clear skies may lead to a brief MVFR valley fog restriction at KLUK toward sunrise Monday.

OUTLOOK...MVFR ceilings and visibilities are possible on Wednesday.

ILN WATCHES/WARNINGS/ADVISORIES

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