Winter Wx Update (Issued Mon. at 1:00 pm)

I took this picture a few minutes ago. It’s icy hear in the north end of Cumberland County.

*First of all, regardless of what happens today, we are ALL in for bitter cold air tonight and tomorrow. Temps much of the day on Tuesday will be in the teens! Memphis is 12 degrees right now.

*The winter storm warning continues, though some will see more wintry conditions than others.

*Thunder is possible this afternoon and evening. There have been reports of “thunder sleet” to our southwest.

*The most important thing to watch is the temperature. We have the moisture, but temps are variable across the area.

The main area of precipitation, the afternoon round of precip that I’ve talked about in days past, is poised to move onto the plateau shortly. Your temperature will determine the severity of the impacts. This precip is coming during the warmest time of the day, which is helping us out.

PLEASE keep in mind that conditions can change rapidly across short distances. Also, keep in mind that once precip starts, temps may fall a degree or two, creating vastly different impacts over short periods of time. Those of you who are 33-34 degrees right now may drop to freezing when heavier precip moves in.

I have been noticing an uptick in power outages across the counties this next batch of precip is moving across. Just an FYI. That blue circled area you see across the plateau is an area the Storm Prediction Center is watching for possible significant ice accumulations. Notice is some places the precip starts as rain (green) and then transitions to ice (pink). Activity is moving east.

Interesting note….the NWS Nashville was going to do a special weather balloon launch at noon to get new data. A software glitch prevented that from happening. Another weather group said they would do one. They released their balloon and it got to about 3,000 feet up before succumbing to ice and fell to the earth. (Things that make us shake our heads, right? ha)

For the past couple of days, it has looked like those of you generally south of I-40 would fare better in this winter storm. That continues to look to be the case. With that being said, there could still be colder pockets of air that lead to your specific location having heavier ice/sleet amounts. Keep that in mind.

I have created graphics for the two areas of the plateau that could experience vastly different effects from this storm. Keep in mind that impacts will vary across the region. At times, those differences could occur across short distances.

Snow totals are still expected to be very light.

If you’ll recall from the past few days, I introduced a worst case and best case scenario. Those of you generally south of I-40 are looking much better for the best case scenario. Those of us north of I-40 are favoring a worst case scenario, with the exception of the heavy snowfall. Sleet will undercut snow totals. If you’ll recall, this was that best case scenario:

Best Case Scenario:

1. The storm pulls up warmer air and the afternoon and evening freezing rain potential turns to plain rain. That would nearly avoid an ice storm in the afternoon, although the morning ice would still be troublesome.
2. The wrap-around snowfall is lighter than expected (or mixes heavily with sleet) and we only get one inch-or-less of snow Monday night.
3. Sleet mixing in at all times, keeping both ice and snow totals lower.

*In a best case scenario, we end up with less than 1/4 inch of ice (below ice storm criteria) and only a dusting of snow on top of that.

**Please not that worse conditions are expected west of the plateau (Monterey–Cookeville–Nashville), with better conditions east of the plateau (Harriman–Knoxville)

**The worst case scenario involves heavy ice accumulations of up to 1/4 – 1/2 inch, with locally higher amounts. That is heavily dependent on surface temperatures and rainfall rates. Heavy icing has already occurred in scattered locations north of I-40, due to freezing drizzle over the weekend that never melted.

For road conditions, please refer to TDOT Smartway at https://smartway.tn.gov/traffic?features=incident,traffic

For power outage info see https://poweroutage.us/area/state/tennessee. Please note that you have to manually refresh the page for updates.

In case you’re wishing you were in Florida, be careful what you wish for. They have severe storms today, with tornado watches being issued.

You all take care. I’ll update again, as needed.

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