Posted by: JeffMasters

It's March in the Southern U.S., and that means it's wildfire season. Strong winds and tinder-dry conditions in Northeast Florida near St. Augustine fanned a 10,000-acre fire that forced closure of I-95 yesterday morning. Other fires are burning in Texas and New Mexico, and a fire in West Texas earlier this week burned over 120,000 acres and caused a fatal traffic accident that killed one person. It promises to be an active fire season across the entire southern tier of states this spring due to a very dry winter. Dry winters in the Southern U.S. are common when unusually cold water is present in the Equatorial Pacific Ocean--La Niņa conditions. This occurs because the unusually cold waters act to deflect the jet stream, keeping wintertime storm systems from traveling over the Southern U.S. La Niņa is gradually weakening, but is expected to last through the spring months, meaning that drought conditions will continue into the summer. There is some relief in sight this weekend for Louisiana, Mississippi, Alabama, and the Florida Panhandle, where a storm system and associated cold front are expected to bring rains of 1/2 to 1 inch. However, Texas and most of the Florida Peninsula will miss the heaviest rains, and NOAA's Climate Prediction Center is predicting much above average chances of dry weather across the Southern U.S. for the remainder of March.

Figure 1. NASA's Aqua satellite detected three large fires burning in eastern Florida on February 28, 2011. According to the National Interagency Fire Center, all three wildfires burned out of control and threatened homes. The largest of the fires is the Iron Horse Fire, burning in northern Brevard County. The 10,000-acre fire produced dense clouds of smoke that forced officials to close parts of US Highway 1 and Interstate 95, said news reports. As of March 1, the fire had destroyed one home and was burning towards more densely populated areas, reported CNN. In the north, the Keller Fire also closed roads, including Highway 1 and Interstate 95. The smaller Ferry-7 fire burned primarily in National Forests. Image credit: NASA Earth Observatory.

Figure 2. U.S. drought conditions as of February 22, 2011, showed large regions of drought over the southern tier of states, with the extreme drought conditions over portions of Texas, Louisiana, Arkansas, Georgia, and Florida. Image credit: U.S. Department of Agriculture.

I'll have a new post on Thursday or Friday.

Jeff Masters