textproduct: Wilmington

SYNOPSIS

A low pressure system moves through today, with light rain ending this evening. A cold front will move through the area Sunday, bringing snow showers, and much cooler temperatures heading into next week.

NEAR TERM /THROUGH SUNDAY/

Broad area of weak low pressure persists over the region today providing rain showers and periods of light rain. Throughout the afternoon, a cold front organizes and then pushes across the area from west to east by the evening hours. Rain chances maximize during the late afternoon and early evening as upper level forcing aids in more widespread activity. Despite the coverage in precipitation, overall rainfall amounts are light (less than one-quarter inch).

As the front accelerates through later today, westerly winds increase to 10 to 15 mph with gusts ranging from 20 to 30 mph. Temperatures drop from the 40s back into the mid to lower 30s late this evening.

After the rain moves out, a potent mid-upper level system dropping southeast through the Midwest and Great Lakes regions provides the opportunity for increased snow shower chances late in the overnight and through Sunday morning. As noted in the previous discussion, the presence of the mid-upper level system (PV anomaly) and cold air advection (steepening lapse rates) support the potential for enhanced snow shower (possibly snow squall) activity, there are some limiting factors. Even with the 12Z guidance suite this morning, the sharpness of the front and delayed low-level cold air advection, decreases the confidence of widespread snow squall coverage late tonight into early Sunday morning. It may take until the better push of colder air behind the first round of snow before road impacts become more of an issue in snow showers. For now, will issue a Special Weather Statement highlighting the potential for light snow and slick spots for Sunday morning.

Special note for initial round of snow (midnight-5 am):

CAM guidance have highlighted an enhanced area of accumulating snow (a couple of inches) on the northern apex of the first band of snow that moves through. 12Z HREF indicates there is a least enough confidence in this potential scenario to highlight it here in the discussion. Until confidence increases, the forecast will not reflect the higher-end solutions, but some localized increase in the snowfall amounts will be provided (>1"). Confidence is expected to increase later this evening as the system should be moving through Illinois and Indiana. For now, a corridor of 1 to 2 counties wide stretching from north of Dayton to Columbus appears to be the area with the best chance of observing this.

SHORT TERM /SUNDAY NIGHT/

As noted previously, snow shower activity is likely to continue through the rest of the morning on Sunday. With the colder air moving in scattered snow showers will result in sudden decreases in visibility with the added potential for slick spots. A third and final push of moisture and snow showers arrives late in the afternoon, pushing south of the area by the evening hours. High temperatures for the day likely occur during the overnight hours as temperatures struggle to rise during the afternoon with snow shower activity, northwest winds, and cloudy skies.

High pressure builds into the lower Ohio Valley Sunday night, with temperatures across the region in the mid 20s (normal for mid Jan).

LONG TERM /MONDAY THROUGH SATURDAY/

Surface high pressure will remain in place across the Gulf States Monday into Tuesday, helping to limit moisture across the Ohio Valley. As a result, expect dry conditions to prevail along with a warming trend through early in the week. Highs Monday will be in the upper 30s to lower 40s, increasing into the mid 40s to lower 50s by Tuesday.

A series of mid level short waves will drop down across the Great Lakes region through the second half of the long term period, helping to carve out a fairly deep upper level trough over the eastern CONUS through the end of the week. The initial short wave will lead to a developing chance for showers Tuesday night into Wednesday. Thermal profiles will support rain with these showers initially, but as a cold front moves through the region during the day on Wednesday, temperatures will begin to drop off with any lingering pcpn transitioning/changing to snow heading into Wednesday night.

Chances for snow showers will then persist at times through the rest of the week, but any pops and coverage will be dependent on the timing and placement of additional short wave energy. Below normal temperatures can be expected Thursday through Saturday.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

Mid level low over the Upper MS Valley to dig east-southeast thru the Great Lakes overnight/Sunday morning. Initial shortwave and associated frontal showers have moved east of the TAF sites. MVFR ceilings to clear for a brief period with clouds scattering out this evening.

Impressive vort associated with a trof to pivot thru the area late tonight/early Sunday. Expect MVFR clouds to move back in with the potential for light snow showers. The first period of potential snow showers will be between 06Z and 10Z with the passage of a secondary front/trof. Additional snow showers will be possible with the mid/upper level trof Sunday morning. In areas of enhanced snow shower activity, IFR VIS will occur, but in general, prevailing MVFR CIGs/VIS were used in the TAF.

MVFR CIGs likely continue through most of the day with improvement from the southwest from mid afternoon on.

Gusty westerly winds will drop off briefly to 10-12 kts this evening and then increase overnight with gusts of 20-25 kts. The winds will become more northwesterly Sunday with gusts of 25-28 kts.

OUTLOOK...MVFR conditions are possible on Wednesday.

ILN WATCHES/WARNINGS/ADVISORIES

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