textproduct: Wilmington

WHAT HAS CHANGED

A few patches of freezing fog are possible through daybreak, otherwise no significant changes. Dense Fog Advisory remains in effect through 11 AM.

KEY MESSAGES

1) Dense fog through late morning, with isolated freezing fog on elevated surfaces through daybreak.

2) Temperatures rising much above normal.

3) Chance of rain and increased winds mid to late week.

DISCUSSION

KEY MESSAGE 1) Dense fog through late morning.

Dense fog will lift later in the morning, as opposed to a typical scenario where daybreak introduces more rapid heating and pressure gradient tightens with a diurnal increase in wind speed. A more or less solid low level stratus deck is expected over the CWA this morning which will take some time to eat through. Winds pick up from west to east, and this will dissipate the fog deck accordingly. Even if the stratus persists past the 11:00 end time of the advisory, surface vsbys will rapidly improve. This is more likely in our far eastern CWA - the Scioto River Valley and nrn KY east of Marysville. ATTM, nw CWA remains on the edge of this fog, though upstream observations are to notch down with mist. This area could clear out quicker this morning, but the current best course of action is to not split hairs for widespread fog to not be as prevalent here. If an update is necessary towards daybreak, they could be cut out at that time if indications show a definitive boundary to do so.

Temperatures will be waffling at or below the freezing mark for a large portion of the CWA through daybreak. This increases the potential for an additional driving hazard with freezing road conditions on elevated road surfaces. Persons travelling in the predawn hours should be on guard for this potential pitfall and monitor their car's thermometer during the commute.

KEY MESSAGE 2) Temperatures rising much above normal.

At this juncture, Wednesday stands to see highs near records for our big 3 metro areas on that day (18th). Both Dayton and Columbus have records at 66 deg, with Cincy at 68. Morning lows within a few degrees of 50 will also put record high minimum temps at risk. For these high mins, records are: Cincy 53, Dayton 49, and Cbus 52.

A building upper ridge looks to peak Tues night and then heights fall as an upper low over the Dakotas pushes a vigorous s/w to the east. At the surface, the associated sfc low will have a warm front extending ese ahead of it in the GtLks region. Our CWA and the OhVly will be in the warm sector, with strong sw wind advecting these unseasonably warm temps through the day. Attm, I see the max temps as the high end values as the upper s/w moving e across the CWA will have a bit of cloud cover associated with it. Its orientation will be in line with the sfc wind direction from sw-ne, so direct heating of the air being advected in does not appear overly favorable. This tells me that there should be some type of hedge to have temps not quite as high. Being day 3, this potential limiting factor will have more than enough time to be taken into account if it remains in play as I am currently seeing it.

KEY MESSAGE 3) Chance of showers/storms and increased winds mid to late week.

The warm front situated north of the region will see a strong moisture transport on sw winds, beginning Tues night with a 50kt jet at 2-4kft. This will get wrung out closer to the wmfnt overnight Tue/early Wed. Chances will occur everywhere, especially as the mid level s/w crosses, but the best chances will occur in nrn CWA during the early morning as the nose of the jet and increased moisture move through the CWA.

Through the morning hours, sustained southwesterly winds of 15-25 MPH are expected, though earlier mention of 35 mph gusts seems to be too high. Maybe some 20-25 mph gusts would be more in line. Warm advection winds do not typically produce excessive gusts as opposed to those produced by sinking motion in cold air. These winds will peak before noon, become more westerly and decrease slowly through the remainder of the day.

Another round of precipitation looks to cross northeast through the CWA on Thurs/Thurs night. This will begin in the later afternoon in srn/sw CWA and lift ne in the evening and first part of the overnight. This timing and placement is relative to a warm frontal passage at these times/locations. Enough isentropic lift will be present with the warm fropa to produce some thunder. This is more of areal convective activity and not discrete thunderstorms.

A cold front will eventually swing through the region late Friday, ushering in cooler air for the weekend. This front will pass to the s, and moisture is expected to eke ne and along it overnight and early Sat. Pattern is in a high potential of change, along with the placement of any subsequent rainfall. Chance pops may be a little high for the nw 1/2 of CWA but there will be a lot of room for change this far out in the forecast process.

As thermal profiles cool, cannot rule out some snow mixing in if pcpn lingers, particularly near/north of I-70.

AVIATION /06Z MONDAY THROUGH FRIDAY/

Significant area of low stratus forming dense fog area-wide will take some time to break up later this morning. Winds pick up from w-e, and there should be a definitive back edge to the stratus as it crosses DAY/CVG/LUK towards noon, ILN shortly thereafter, and slightly later at CMH/LCK. However the stratus decides to show its back edge, cigs/vsbys will be improving across the terminals a little before these low clouds exit to the east.

OUTLOOK...MVFR ceilings and 25kt gusts are possible on Wednesday.

ILN WATCHES/WARNINGS/ADVISORIES

OH...Dense Fog Advisory until 11 AM EST this morning for OHZ026-034-035- 042>046-051>056-060>065-070>074-077>082-088. KY...Dense Fog Advisory until 11 AM EST this morning for KYZ089>100. IN...Dense Fog Advisory until 11 AM EST this morning for INZ050-058-059- 066-073>075-080.