Lake Effect Snow through Friday; Heavy Rain, Thunderstorms and Mountain Snow in California

Periods of moderate to heavy lake effect snow will continue through Friday downwind of Lake Erie and Ontario. Several additional inches of accumulating snow are expected. A Pacific storm will bring heavy rain and mountain snow across California, the Southwest and Intermountain West today. Isolated severe thunderstorms and scattered flash flooding is possible across parts of southern California. Read More >

CHRISTMAS EVE 2009 TORNADO OUTBREAK

Overview

A powerful upper level storm system moved across the Southern Plains and Lower Mississippi Valley from Wednesday, December 23, 2009, through Thursday, December 24, 2009. Numerous showers and elevated thunderstorms, including some supercells, repeatedly developed and moved northward across much of southwest Louisiana and the northern Gulf of America from late Wednesday evening into Thursday morning. As the main upper level system approached Louisiana early Thursday morning, a squall line developed across east Texas and moved rapidly eastward across Louisiana, causing several reports of wind damage in southern Louisiana. Meanwhile, some of the elevated supercells became surface-based and tracked north-northeastward across south-central and east-central Louisiana, spawning at least a dozen tornadoes. In addition, the widespread rainfall caused flooding in some of these same areas.

In total, at least 12 tornadoes affected portions of Vermilion, Acadia, St. Landry, Evangeline, and Avoyelles Parishes within a two hour timespan from 7-9 AM. Seven tornadoes affected Acadia Parish alone, the biggest single outbreak of tornadoes ever recorded in that parish. Three tornadoes were rated EF2, three were rated EF1, and six were rated EF0. Other tornadoes likely occurred that were reported by area residents but could not be confirmed by NWS storm surveys. These included a likely tornado just east of I-49 in extreme northeastern Evangeline Parish, a possible tornado about 8 miles southwest of Gueydan, and another east of Palmetto in far northeastern St. Landry Parish. This was the largest outbreak of tornadoes in the NWS Lake Charles county warning area since November 23, 2004.

Local Storm Reports

Experimental Graphical Local Storm Reports for December 24 2009
SPC Storm Reports for December 23 2009
SPC Storm Reports for December 24 2009
List of all Local Storm Reports for December 24 2009
December 24 2009 Google Earth KML data file