TONIGHT: Wintry Mix (Wet Snow, Sleet, & Freezing Rain) Develop After Midnight. Lo 29.

THURSDAY: Icy Mix To Rain, Breezy. Continued Periods of Snow NW of Harrisburg. Hi 38. Winds: E 10-20 mph. Gusts to 35 mph.

FRIDAY: Showers Ending by Mid-morning. Breezy Afternoon. Hi 42. Winds NW 5-15 mph.

A mixture of snow and sleet looks to develop overnight into the pre-dawn hours of Thursday. This initial period of snow and mainly sleet overspreads the entire region by dawn Thursday, followed by a slow transition to freezing rain and eventually plain rain. The key will be temperatures and how long it takes to overcome the stubborn cold air at the surface. The column of air above us should warm up more quickly, leading to the transition to icy precipitation types first. Eventually, at some point by mid-morning into the afternoon, most of Central PA should be seeing rain as temperatures rise above 32°. There will continue to be pockets of freezing rain, however, well into the afternoon, especially for northern spots. That freezing rain for northern areas will also turn over to snow as the colder returns on the northern side of the storm.

Thursday’s timeline.

The greatest travel impact from this storm will be tomorrow morning when there will still be enough cold air established across the region. This will likely lead to slick and icy spots, especially on sidewalks and secondary roads. As milder air nudges northward, a change from an icy mix to rain is expected by mid-morning into the afternoon and evening, with improving travel conditions expected. A period of wet snow and sleet re-develops north and west of Harrisburg during the evening hours and Thursday night. Several inches of snow are likely for areas northwest of Harrisburg into Mifflin and Juniata Counties. This still won’t be a snowstorm for the majority of our region, however. An icy mix and mess is the best way to describe it. One other note: a stiff east breeze will persist throughout Thursday adding to the nasty conditions.

Travel conditions Thursday.
While this will primarily be a sleet storm, some slushy accumulations are possible. Accumulating snow is most likely for Mifflin and Juniata Counties into northern Perry and northern Dauphin Counties.

As the storm exits Friday morning and the rain wraps up, much colder air and a steady breeze return for the weekend. This pattern will bring several more chances for wintry weather as we get closer to the holidays. As always, we’ll stay on top of it and explain it right here…so bookmark this page and let it be your source for local weather. In the meantime, prepare for tomorrow and use caution. It won’t be the worst storm we’ve had to deal with, but it will likely start on the ugly side before conditions improve through the day. Be safe!

-Meteorologists Eric Finkenbinder and Dan Tomaso