textproduct: Wilmington

WHAT HAS CHANGED

Increasing confidence with snow for Tuesday.

KEY MESSAGES

1) Another bitter night with some very light snow possible Monday.

2) Accumulating snow across southeast Indiana, southern Ohio, and northern Kentucky Tuesday into Tuesday evening.

3) Clipper moving across the area Thursday and Friday.

DISCUSSION

KEY MESSAGE 1) Another bitter night with some very light snow possible Monday.

Surface ridge axis will translate across the region tonight. This will result in winds backing to the south, and there may be a slight increase in speed in western counties late. There could be some patchy low clouds around in the evening, but for the most part it will be clear. During the overnight hours clouds will translate into the area. Temperatures will drop back into the single digits through the evening. The drop will slow or stop in western counties but still continue in the east. So central Ohio outside of the Columbus metro is forecast to fall below zero. Combined with a little bit of wind and wind chill will be subzero areawide, although not reaching advisory threshold.

Weak short wave will translate across the region on Monday, getting absorbed into a stronger short wave moving southeast across the Great Lakes. An associated surface trough, a bit of a pseudo warm front, will move through as well. Lift is rather weak but guidance continues to produce some splotchy, very light QPF. This warrants low chance PoPs for measurable (liquid) precipitation. But even trace liquid amounts could result in a tenth or two of snow accumulation. So there may be more widespread very light accumulation than would be inferred from the PoP. With very cold ground, this could bring some slick spots.

KEY MESSAGE 2) Accumulating snow across southeast Indiana, southern Ohio, and northern Kentucky Tuesday into Tuesday evening.

Guidance keeps coming into better agreement that an east-west axis of frontogenesis will develop into the area Tuesday. There are some discrepancies in where the resultant band of snow will be located, but the latest model suite continues to support south of I-70. In addition to this band, there will be more general lift with a short wave that will move from the mid Mississippi Valley into the central Appalachians Tuesday into Tuesday night. So while the frontogenetic band could have locally higher accumulations, there will be a more general snow, mainly in the southern half of the forecast area. Accumulations of 1 to 2 inches are possible.

KEY MESSAGE 3) Clipper moving across the area Thursday and Friday.

Model suite remains fairly consistent in bringing a clipper across the region late Thursday night into Friday. As would be expected that far out in time, there is some spread in the details. Probability of having minor impacts ranges from around 40 percent in central Ohio to less than 10 percent from eastern Indiana into northern Kentucky. Will see how this system trends as we head through the week. Another surge of Arctic air will come in behind the system for next weekend.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

There remains some patchy low clouds across the area to start the period, but those will continue to diminish. Outside of that, VFR will continue with clear skies. A deck of low clouds will spread into the region from the west after 06Z. There is some uncertainty in what level they arrive. Have forecast an MVFR ceiling, except at KDAY where there is a better chance of IFR. And there is certainly potential for IFR ceilings at other sites as well, perhaps not initially but falling into that category. These ceilings will persist through the end of the TAF period. In addition, where ceilings do become IFR, visibilities will drop to MVFR to IFR. A bit of very light snow may occur late in the period. Probability of visibility reductions at any particular terminal were too low to include at this time.

OUTLOOK...MVFR to IFR ceilings will continue into Tuesday night. MVFR to IFR visibilities are possible Tuesday.

ILN WATCHES/WARNINGS/ADVISORIES

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