Tuesday, December 25, 2012

Christmas Storms

The latest winter storm system has dropped across the Southwest and, as of this morning, its central low is spinning just north of Lubbock, Texas.  Sweeping moisture in a counterclockwise direction, it is producing upslope snow across the High Plains and along the Front Range.

To its east, the potent storm is dragging copious moisture up from the Gulf of Mexico, igniting strong thunderstorms and unleashing torrential rains from eastern Texas to western Alabama.  Of special concern is the risk for tornadoes; this has developed due to the position of the low level jet stream which curves west and south of the low and then tracks across the Southeastern States.  Clashing with the southerly winds of the storm's circulation, this westerly jet is injecting energy and producing spin in the atmosphere, thus augmenting the risk of tornadic thunderstorms.

The greatest risk of tornadoes is across Louisiana and Mississippi this morning but will shift into Alabama, north Florida and Georgia later in the day.  North of these storms, a swath of ice and freezing rain is expected to impact the Ohio Valley in the coming days and the storm system will eventually bring snow to the mountains of New England.