textproduct: Wilmington

WHAT HAS CHANGED

Issued winter weather advisory for this morning. Increased chances for snow showers and winds this morning.

KEY MESSAGES

1)Snow showers and blowing snow this morning. Below normal temperatures continue through Tuesday.

2)Next chance for rain and snow impacts the area for mid week.

DISCUSSION

KEY MESSAGE 1)

Snow showers and drifting snow are impacting area roads this morning with reports of slick conditions and accidents. The overnight light snow has resulted in a melt and refreeze leading to the formation of black ice this morning. Metro road model shows road surface temperatures in the mid 20s. Have issued a winter weather advisory to alert motorists to these slick conditions. The snow showers are expected to decrease in coverage this morning and road temperatures warm up - so have the advisory through 11 AM.

Previous discussion...

Highly amplified mid level flow with deep low pressure off the Mid Atlantic coast placing the Ohio Valley in northerly flow. Impulses embedded in the flow to drop thru the area this morning. Steep low level lapse rates with the saturated layer in the favorable DGZ will continue to be favorable for snow showers. These snow showers will be enhanced with flow off the Great Lakes. NBM model tends to struggle ending snow showers too soon in these situations. Therefore pops have been increased to reflect this potential thru the morning. HREF shows 60 to 70 percent probability of a half inch or more of snow across portions of central Ohio. For the forecast have any additional accumulation up to around a half inch with this best potential across central Ohio. With road temperatures below freezing - slick spots will remain possible. Also, northwest wind gusts will result in blowing and drifting snow. Have an SPS to highlight the travel impacts for this mornings commute.

KEY MESSAGE 2)

Model solutions have trended farther south with system tracking through the region at mid week. Latest ensemble solutions bring a low pressure system through southern portions of the Ohio Valley late Wednesday into Thursday. Return flow looks to bring a surge in deeper moisture north just ahead of the system. There is still large spread in solutions and therefore a good deal of uncertainty. This southern trend allows for more snow potential along and north of I-70 where the potential exists for several inches of snow. NBM indicates a 20 percent chance for snow accumulation above 3 inches across ILN/s extreme northern counties. While PWATs increase the latest solutions have less of an anomaly with values 150 to 200 percent of normal across the south. The system is progressive with rainfall approaching an inch possible across northern KY and along the Ohio River.

AVIATION /12Z MONDAY THROUGH FRIDAY/

Deep low pressure off the East Coast with cyclonic flow across the Ohio Valley. Impulses embedded in the northerly flow to continue dropping south thru the area this morning. Steep low level lapse rates with the saturated layer in the favorable DGZ will continue to be favorable for snow showers. These snow showers will be enhanced with flow off the Great Lakes. Snow showers will reduce visibilities to MVFR with occasional IFR conditions in the heavier snow showers especially at KCMH and KLCK early. Snow showers decrease in coverage thru the morning and tapper off this afternoon.

Expect widespread MVFR ceilings through the morning before improving to VFR during the afternoon across most of the TAF sites. MVFR ceilings may linger across KCMH and KLCK into early evening. In the tight pressure gradient northwest winds to gust up to 25 kts at times thru the daylight hours.

OUTLOOK...MVFR to IFR conditions possible Wednesday night and Thursday.

ILN WATCHES/WARNINGS/ADVISORIES

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