textproduct: Wilmington

SYNOPSIS

A cold front will bring colder temperatures to the region today, with some snow expected this afternoon. Much cooler air will be in place for Thursday and beyond, with especially cold conditions early next week. The next chance for snow will be on Friday and Saturday, as another low pressure system moves through the Great Lakes.

NEAR TERM /THROUGH TONIGHT/

An expansive area of upper troughing is located over the Great Lakes and vicinity. Precipitation chances will gradually increase through the morning, initially associated with some upper-level forcing associated with the right entrance region of the jet. This jet feature, at the base of the trough, will eventually pivot from more of a WSW-to-ENE orientation to a SSW-NNE orientation, meaning that the footprint of measurable precipitation will largely stay south of the I-71 corridor. Even still, rainfall amounts should be light, in part because of the dry air yet to be overcome. Many of the radar echoes currently being observed are virga, and KCVG (for example) has a 22 degree dewpoint depression as of 1AM.

The more notable feature for the weather today will be a cold front moving southeast into the area. Based on HRRR/RAP projections, this front should cross the ILN CWA between 15Z-23Z. Winds behind the front will switch to the northwest, with some 25-35 MPH gusts expected. Not out of the question that a spotty 40 MPH gust could occur in the northern part of the forecast area. As temperatures cool quickly, precipitation will change to snow, and will become more showery than stratiform -- with a well-mixed boundary layer, and maybe a very small amount of convective instability at the top of the mixed layer. So, although the snow shower activity may be scattered in nature, the main concern will be the potential for a few brief heavier snow showers that could reduce visibility and drop some light accumulations -- generally under a half inch. More widespread accumulations of snow appear unlikely with this system.

SHORT TERM /THURSDAY/

With a continuing cold advection pattern tonight into early Thursday morning, and a persistently well-mixed boundary layer, gusty winds and snow showers / flurries will likely continue well into the overnight hours. Falling temperatures, particularly on roadways, could result in some hazardous driving conditions. In addition, wind chills will get into the single digits Thursday morning as well.

LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/

A brief lull in precip activity ensues Thursday night as the upper Ohio Valley remains wedged between two shortwaves. However, precip could move back into our western counties early Friday morning based on some model guidance. Thermal profiles remain below the freezing mark and thus will keep the p-type as snow. Some warm air does intrude our southern counties Friday afternoon, which could allow for some rain to mix in for locations near/south of the Ohio River. Otherwise, periods of snow will be possible for the majority of our counties Friday, Friday night and perhaps into Saturday as well. CAM guidance will help provide a bit more clarity on timing of best potential snow accumulation, as well as amounts. Accumulating snow does appear likely for the majority of our CWA, but right now it doesn't appear to be anything substantial (low probabilities for anything greater than 3"). Best probability for an inch or greater will be in the northern half of our CWA, but still too early to get into exact totals.

Still some uncertainty with how long snow may linger into Saturday. After temperatures slightly moderate on Friday, they take a dive again on Saturday as highs generally remain in the 20s.

The synoptic pattern will continue to feature a longwave H5 trough across the eastern CONUS through the end of the weekend and into the following work week. Some shortwaves will continue to eject through the longwave trough to help maintain it. These shortwaves may also result in episodic chances for light snow, but those details are still unknown. What is known is that we will have seasonably cold temperatures through this stretch, with lows either reaching or approaching the single digits from Saturday night onwards. This will result in wind chill values near or below zero during the overnight/early morning hours for a number of days.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

VFR conditions are beginning to give way to MVFR to even possibly IFR ceilings, and there should be an overall trend toward lower ceilings over the next few hours. Some light rain has also been observed, but with little additional impact to aviation conditions. MVFR visibilities will be possible by early afternoon.

During the afternoon, a cold front will move through the area, shifting winds to the NW and bringing a chance of snow showers. Where snow showers occur, MVFR to IFR visibilities and ceilings will be possible. Confidence in snow shower timing and location remains somewhat low, so these will be covered by a PROB30 for now, but could be included in a FM or TEMPO group later if confidence increases. NW winds will gust into the 25-30 knot range behind the cold front, and then will likely stay above 20 knots well into the overnight hours. A mix of VFR to MVFR ceilings will likely continue into Thursday morning.

OUTLOOK...MVFR conditions are possible Friday into Saturday with snow. Gusty winds are also possible Friday into Saturday.

ILN WATCHES/WARNINGS/ADVISORIES

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