textproduct: Wilmington

SYNOPSIS

A wintry mix of precipitation is likely Saturday into early Sunday as a system moves through the Ohio Valley and Great Lakes, with the potential for some accumulating snow. Below normal temperatures are expected to continue into next week with another threat for winter precipitation on Tuesday.

NEAR TERM /THROUGH TONIGHT/

Area is dominated by surface high pressure overnight, with mostly clear skies under upper level NW flow, with gusty westerly surface winds diminishing overnight as the pressure gradient relaxes. Overnight lows in the upper teens to lower 20s with a good radiational cooling night, then clouds move in well after midnight to allow for the warmest overnight lows in the lower 20s in the southwest, but mid/upper teens in the east closer to the center of the surface high as it slowly drifts east.

SHORT TERM /SATURDAY THROUGH SUNDAY/

During the day on Saturday, a deepening upper level trough and associated surface low lifts into the lower Ohio Valley and central Great Lakes. Still some uncertainty with timing onset as differences in saturation of the column and positioning of the best area of isentropic lift near and south of the I-70 corridor of eastern Indiana/west central Ohio.

Current thinking is onset of very light snow by late morning generally along/north of I-70 along the Ohio/Indiana border, with initially not much in the way of accumulations, and then accumulating snow near/north of I70 and near/west of I75 into the late afternoon and especially Saturday evening/overnight.

Still the highest probabilities of 2 snow from near Richmond, IN northeast to near Kenton, OH and points NW, with the greatest potential for 4 also in this area. Went a little broad with the coverage of the winter weather advisory with the potential impacts of holiday travel Saturday late afternoon into Saturday night, when steadier precip overspreads the region. Still a fair amount of uncertainty with the warm air push cutting into snow totals along the southern tier of the advisory area into SE Indiana and SW Ohio. If any heavier banding of precipitation occurs before the evening warm air push, there could be areas of >2 accumulations along the southern/ eastern tier of the advisory area.

While snow accumulations of less than 1 inch are possible SE of the I-71 corridor, this remains the the most favorable location for a mix in of rain Saturday evening/overnight. A greater number of ensemble members are pointing toward a slower onset time of precip during the day south/east of the I-71 corridor, which should mitigate accumulations to less than 1 and rain mixing in.

Accumulating snow will come to an end Sunday morning as the cold front pushes through the region, bringing gusty W to NW winds to 25-30mph. Some lingering snow showers are possible across the far NW, but the front will be slow to clear the SE forecast area, where highs in the lower to even mid 40s are possible on Sunday.

Daytime highs on Saturday range from low/mid 30s in the NW to near 40 in the southeast, with upper 20s to lower 30s for lows Saturday night.

LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/

Surface high pressure builds into the Ohio Valley Sunday night, then quickly moves to the east on Monday. Meanwhile, shortwave energy over the Plains will be fast to approach by Monday night. At the same time, computer guidance suggests a surface low developing to the south. Impacts across the local area will be for an increase in clouds during the daytime Monday and precipitation developing Monday evening or Monday night across the CWA.

While confidence is increasing that a storm will likely impact the Ohio Valley in the Monday evening through Tuesday afternoon time frame, details are much more uncertain, including precipitation types and amounts at various time frames. There is the potential for a plowable snow event for some, however there could also be mixed precipitation which would impact snow totals. Continue to check the latest discussions and forecasts as details become more clear the closer we get to this potential storm early next week.

High pressure is expected to make a return by Wednesday of next week. A cold front may bring a reinforcing shot of cold air for the end of the week, however the balance of the second part of next week is expected to be dry at this time.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

High pressure will keep VFR conditions through much of the TAF period, with greater clouds toward CMH/LCK with lingering moisture fetch off Lake Michigan. Some elevated winds to near 20kts in the lingering pressure gradient, but skies will become mostly clear with light winds overnight for much of the region.

Clouds will be on the increase ahead of a potent weather system to push through western Ohio Valley and central Great Lakes, bringing onset of light snow to mainly KDAY toward the end of the period, with potential for MVFR in -rasn for KCVG in the 18z-00z extended TAF period.

OUTLOOK...MVFR/IFR CIGs and VSBY with wintry precipitation likely late Saturday into early Sunday. LIFR CIGs and VSBY will be possible during this time. Snow may bring additional reductions to CIGs and VSBY on Monday night into Tuesday as well.

ILN WATCHES/WARNINGS/ADVISORIES

OH...Winter Weather Advisory from 7 AM Saturday to 9 AM EST Sunday for OHZ026-034-035-042>046-051>055-060>062-070-071. KY...None. IN...Winter Weather Advisory from 7 AM Saturday to 9 AM EST Sunday for INZ050-058-059-066.