textproduct: Wilmington

SYNOPSIS

Conditions will remain warmer than normal through Saturday, with chances for rain Thursday night into Friday, and then again on Saturday. Breezy conditions will be possible at times. After a cold front moves through the area, cooler weather is expected for Sunday and beyond.

NEAR TERM /THROUGH TONIGHT/

Updating to include a Dense Fog Advisory for a portion of the area, with numerous observation sites (mainly in central Ohio) at 1/4SM visibility.

Previous discussion (125 AM) > The main concern in the near term is for fog, particularly in central Ohio. Nighttime microphysics satellite imagery is helping to show that fog has become most prevalent across the Columbus metro area, with some patchier fog extending into the Dayton metro area, and river valley fog impacting the lower Scioto and parts of the Ohio basins. Clear skies and light winds have created conditions to favor fog development, but a slight increase in winds over the next few hours could keep the dense fog from becoming overly widespread. Still, confidence is not overly high that it will dissipate quickly, so continued Special Weather Statements (or a Dense Fog Advisory if the fog becomes thicker and more concentrated) will probably be needed through morning.

Aside from this, the weather today will be characterized by increasing high and mid level clouds, and gradually increasing southerly flow. Highs in the mid 50s to lower 60s will be well above normal for early January.

SHORT TERM /FRIDAY/

Active weather is expected tonight through Friday. An area of surface low pressure will be gradually weakening as it moves northeast from the Quad Cities area this evening to the Upper Peninsula of Michigan by Friday morning. Deep-layer southerly / southwesterly flow will be in place across the Ohio Valley ahead of the low, with a cold front expected to pass through the area during the daytime hours Friday. This front will switch winds to the west and result in falling temperatures.

Wind will be the main impact from this system. As of now, confidence is not there to suggest advisory-criteria winds at any point during this period, but it is not out of the question. First, there will be warm advection winds late Thursday night into early Friday morning. Although there will be very strong winds aloft -- 50-60 knots at 850mb -- a near-surface inversion will keep these winds from being fully realized. This forecast will allow for 25-35 mph wind gusts through this period, but this could be a little conservative, and there is some potential for it to be a little higher. A broken line of showers may also form on a pre-frontal trough ahead of the cold front, moving through some time very early Friday morning.

Immediately behind the cold front on Friday, a period of gusty westerly winds is expected, perhaps as high as 40-45 mph depending on the depth of the mixing. The strongest of these gusts should only last a few hours behind the front, before the pressure gradient begins to relax. There are still some model timing differences on when exactly the front will move through the area, but it should be some time during the daytime hours on Friday. Although steadier precipitation will be coming to an end once the front passes, there are some signs of light rain or drizzle persisting behind the front for a while. Temperatures should remain too warm for snow.

LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/

Initial wave of rain shifts east of the CWA Friday night as a cold front slides through the region. While surface winds shift to the northeast, southwesterly flow is maintained through the majority of the troposphere given the longwave H5 trough that is positioned across the central CONUS. Thus, moisture influx will continue into Saturday, and as additional PVA pivots through the region, periods of rain showers will continue throughout the day on Saturday.

Widespread rain chances rapidly diminish Saturday night, with cold air being ushered back into the Ohio Valley. Given the location of the H5 trough and persistent northwesterly flow off the Great Lakes, some light snow may develop on Sunday before the trough propagates eastward. As of now, limited snow accumulations (if any) are expected.

The weather pattern would suggest a dry start to the following work week. However, a mix of rain and snow will return by midweek with the progression of another longwave H5 trough.

AVIATION /11Z THURSDAY THROUGH MONDAY/

In the near term, fog will be the main aviation impact, with MVFR visibilities at KILN/KDAY/KCMH, and occasional IFR to LIFR conditions at KLUK/KLCK. These conditions should improve by 14Z.

VFR conditions are then expected during the day, with increasing mid level cloud cover. By afternoon and evening, winds will begin to increase from the southwest, with some gusts to around 20 knots. These winds will continue to increase overnight into early Friday morning, with gusts up to 25 knots, and a lower-end chance of gusts exceeding 30 knots (not specifically included in the TAFs at this time). LLWS will also occur for a period of several hours at each TAF site.

Showers are expected to move into the area after 08Z, though aviation impacts should be limited. Ceilings will eventually drop to MVFR on Friday morning.

OUTLOOK...MVFR to IFR conditions are possible Thursday night into Friday. Gusty winds are also expected on Friday. MVFR to IFR conditions are possible again Saturday into Sunday.

ILN WATCHES/WARNINGS/ADVISORIES

OH...Dense Fog Advisory until 9 AM EST this morning for OHZ026-044>046- 052>056-063>065-073-074-082-088. KY...None. IN...None.