Winter Weather Outlook (1/11, 4 pm Update) for Jan 15-18

Good Sunday afternoon,

Well, winter has made its return to the Western Carolinas. After dealing with rain and temperatures in the 60’s on Saturday, northwest winds are howling today and the mountains have picked up a little bit of snow on northwest flow.

Looking at the water vapor image below, you can see a sharp northern stream trough that is moving across the Appalachians, that is the catalyst for today’s return to cold.

All the players continue to come together for a cold weather pattern this upcoming week that could flirt with winter weather opportunities, the first being on Thursday and a second piece of energy coming late Saturday and into Sunday of next weekend.

Confidence is growing on the mid-week scenario as a large trough digs down into the Eastern US. Recently, the global deterministic models were being quite bullish on an upper low briefly cutting off across the Carolinas. However, today’s guidance has come in with a scenario where an upper low crosses directly over portions of Eastern Kentucky and Western Virginia, then closing off across the Mid-Atlantic region. This scenario would suggest that any accumulating snow across the Carolinas should remain relegated to the mountains on northwest flow during the day on Thursday.

(Sun Jan 11) 12z GFS 500 mb and SFC

(Sun Jan 11) 12z Euro 500 mb and SFC

With both the Euro and GFS sliding the 500 mb energy just to our north, we feel the chance of accumulating snow just east of the Blue Ridge is diminishing. Could there be some northwest flow flurries spilling off the mountains? Yes, that’s plausible. But accumulating snow should be confined to the High Country and the Smokies.

Weekend snow chances still in question

Regardless of whether it snows on Thursday, the region will be re-established in cold air from the northern latitudes. Meanwhile the next shortwave comes digging in and by Saturday the shortwave will be crossing the Mississippi River.

With cold air established, a storm track further south is definitely plausible. Right now the GFS and European are in conflict as to how strong the upper level energy digs Saturday.

European 500 mb (Sunday 1/18, 1 am)

Shortwave energy on the European glides ESE from the Plains down into the Tennessee Valley and is crossing the Southern Appalachians by daybreak Sunday. This is a fast, progressive flow that shows little to no moisture response until northwest flow interacts with the Appalachians.

GFS 500 mb (Sunday 1/18, 1 am)

The GFS model digs energy further west and as a result pulls a band of moisture across the Southeast US late Saturday Night and early Sunday, some of that falling as snow across the western half of North Carolina and back into the Tennessee Valley.

Summary

A cold weather pattern will lock in this week and will stick through most of the current 10-Day forecast.

Confidence of accumulating mountain snow on Thursday is rising with flurries possible across the Foothills.

It’s the second feature for next weekend which needs to be monitored closely. This remains in that 5-7 Day range where we will be tracking the trends over the next 24-48 hours.