Thursday, January 23, 2014

Sleet, Snow Tonight?

We've talked about it all week and today the chances of a little wintry precipitation in parts of the WAFB viewing area have increased for tonight into early Friday. With that in mind, the National Weather Service has posted a Winter Weather Advisory for the areas below, including metro Baton Rouge. These are the areas where it's believed there could at least be some light accumulations of sleet and snow. And late word this afternoon...the National Weather Service tells us they will likely expand the advisory eastward a bit later today. We don't know yet exactly how far east it may extend.


Throughout the week, it was pretty clear temperatures would be supportive of some wintry precipitation. The big question was would there be any moisture available? And the big change in our computer models late last night and today has been to trend toward a bit more in the way of available moisture and therefore just a bit more wintry precipitation. To be clear, we don't expect everyone to see sleet and/or snow tonight and for most that do see anything accumulations should be light.

One reason for increased confidence of at least some wintry precipitation in the WAFB viewing area is greater agreement among the models. A few snapshots of model projections are below:

RPM model projection for accumulated snowfall through 6 AM Friday. Note that this model keeps most areas under 1 inch of accumulation.
European model projection for accumulated snowfall. The latest available run from Thursday morning was a little more ambitious with snowfall potential. (Image credit: Weatherbell.com)
WRF model projection for accumulated snowfall through 6 AM Friday. (Image credit: Weatherbell.com)
GFS model projection for accumulated snowfall through 6 AM Friday. (Image credit: Weatherbell.com)

You'll note in the images above that the general consensus is that the greatest potential for wintry precipitation will be west of the Atchafalaya basin, but at least some potential extends into metro Baton Rouge.

In terms of timing, precipitation chances will increase near sunset today. Anything that falls near and shortly after sunset will likely come in the form of rain or a rain/sleet mix. However, model soundings (showing a vertical profile of temperatures in the atmosphere) indicate that a transition to mainly snow could occur as soon as a couple of hours after sunset. And anything that fell during the overnight would likely fall primarily in the form of snow except for areas closer to the coast.

The vast majority of any frozen precipitation would likely end by sunrise on Friday, although we can't completely rule out some lingering just a little longer than that. At this point, we're not anticipating major travel issues or roadway problems, but it will have to be watched closely. Low-traffic bridges and overpasses would be the greatest concern.

Another big concern will be the combination of very cold temperatures and wind on Friday morning. Freeze and Hard Freeze Warnings are in effect for just about all of our viewing area. Additionally, wind chills will likely be in the teens Friday morning and could flirt with single digits in northern parts of the viewing area.


We'll continue to keep you updated through the afternoon and tonight both online and on-air. Be sure to follow us on social media for more frequent updates:

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