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Travel Problems To Begin At 4 p.m.

**1:19 p.m. Update**

From the NWS:

For Nashville metro area . . . temperatures are mostly in the 33-35 degree range . . . with the freezing rain slowly approaching.

“There have been a few reports of ice forming at the highest elevations of west of I-65.

“The Winter Weather Advisory is still set to start at 4 p.m. . . . which should line up with the beginning of travel problems.

“Look for the bridges to start icing from Joelton down to Fairview, then the slick conditions will spread across the metro area into the evening.

“Much of the precipitation will end for Nashville by 10 p.m. or so, but leftover moisture and rapidly falling temps will keep some slick spots around.

“Winter weather impacts appear to decrease for locations farther south and east as the moisture decreases and the dynamic support pulls away quickly by late evening. Still, caution is advised as light freezing drizzle may result in some slick spots, especially bridges.”

Source.

**11:31 a.m. Update**

This is in-line with what we wrote, below. Everything still on track.

**Mid-Morning Update**

Is this another one of those: “nothing to see here. Move along” situations?

No.

We still think there’s something to see here. Small, but worth your attention.

We are getting plenty of rain this morning. This will continue this afternoon and after dark tonight.

The issue, then, is when surface temps will hit the magic 32 number.

According to the HRRR, we should stay close to — but above — freezing during daylight hours.

By mid-afternoon (beginning as early as 2 p.m.), the HRRR thinks some wintry precip will be mixing in. I’m not so sure about that given the above-freezing temps aloft and the HRRR itself saying we’ll be above freezing at the surface from 2 p.m. to 5 p.m.:

The updated NWS graphic has us on the “warm” side of the freezing line at 4 p.m. By dark, the freezing line should begin its approach into Davidson & Williamson Counties.

By 7 p.m. (per the HRRR), we’re there.

NOTE: Freezing temps may happen at higher elevations, on bridges, and overpasses, before dark.

The  issue is whether there will be precip around during this after dark freezing period.

After “losing” (not predicting) any precip during this time in earlier HRRR model runs, the latest run of the HRRR “found” it. 6 pm to 10 pm:

Other models (the RAP, NAM, GFS, and Euro) agree we will see some precip during our “frozen” post-sundown hours. It won’t be a lot of precip, but just enough to coat us with a thin layer of ice after dark. As the freezing rain pulls out, we may briefly see a blast of sleet or snow.

For this reason, we remain under a Winter Weather Advisory from 4 p.m. until Midnight:

So, the forecast remains on track.

Travel problems are possible tonight — remember: rain does not mean safety. “Freezing Rain” should be called “Rain That Freezes.” It’ll fall through warmer air as rain, then freeze when it hits the ground. Bridges, overpasses, and other areas at elevation are especially vulnerable.

Rain will end tonight, and pick back up again Saturday night, when we’ll get to do this all over again. Some freezing rain is possible then, too.

This blog is a supplement to coverage on Twitter @NashSevereWx.

Categories: Uncategorized