Saturday, February 18, 2012

Update on Snowy Side of Weekend Storm System...

I've posted several times today regarding the severe thunderstorm, tornado and flash flooding threat associated with the strong weather system moving across the South.  This update pertains to the wintry side of the system, and in particular, the potential for significant snowfall on Sunday as the system lifts up into the Appalachians and mid-Atlantic coastal region.

The latest water vapor satellite image (above) shows the center of the middle and upper-level storm system over eastern Texas, with energy and stronger winds aloft spreading up North, to the East of the system, across the Mississippi and Tennessee Valley regions.

A large swath of precipitation extends ahead of this system, across the Deep South and Southeast:

As the system lifts out to the East/Northeast overnight and into Sunday, precipitation will increase out across the Appalachians and the mid-Atlantic region.  Temperatures across this region will become cold enough to support snow on Sunday afternoon and evening.

At this time, it appears that the axis of heaviest snow will extend from northcentral Tennessee across southcentral and southeastern Kentucky, and into the Virginia's.  A Winter Storm Warning is in effect for the pink shaded areas on the image below, with a Winter Storm Watch in effect for the purple shaded areas:

Within this region, widespread accumulation of up to 4 inches is likely, with localized amounts of a foot or more over the mountains of southwest Virginia.

The following images show the probability of up to 4 inches of snow:

...and 8 inches of snow:

...and 12 inches of snow:

The red outlined areas on each image show a "high" likelihood of the indicated amount of snow, while the green outline shows a "moderate" likelihood, and the blue a "slight" likelihood.

At this time, it appears that the majority of the snow across this region will take place from late in the morning into the afternoon hours on Sunday.  The Eastern portions of the outlook area will experience the bulk of their snowfall from mid to late afternoon into the evening.

Folks across this region should keep an eye on weather conditions on Sunday.  Try to avoid travel if possible, but if you must venture out, be sure to allow extra time to reach your destination safely, and check on road conditions before heading out.

At this time it appears that the Washington DC area will escape with around an inch or so of snow.  As far as the "major" cities go, Richmond, VA has the highest probability of significant snow, likely in the 3-6 inch range the way it looks right now.

If you enjoy reading 'The Original Weather Blog', please be sure to "like" our facebook page!

No comments: