A look at weather extremes and the big-picture climate connections.

Wildfires and No Drought Relief in Sight for Southwest

Water, water, everywhere, but not a drop to spare. Across large parts of the Southwest, that is. 

All along the Mississippi River, from Illinois to Louisiana, record floods continue to drown towns and farmland following the wettest April on record for several states in the Ohio River valley, which has in turn engorged the Mississippi. But while some areas remain under water, other regions have been suffering from the opposite extremes of drought and wildfire. In fact, tinder-dry conditions across Texas and other parts of the Southwest have fueled a rare start to the fire season, with more than twice as much land area already burned than at this point in any other year in the past decade.

Texas State Troopers look on as wildfires burn near Graford, Texas in April 2011. Credit: Tom Pennington/Getty Images.

Several of the fires that burned across western Texas last month have now been contained, although according to the Texas Forest Service, two wildfires — both in Brewster County along the Mexican border — are still burning with some out-of-control areas.

Farther southwest, fires are also still raging, particularly through Arizona and New Mexico, which are experiencing severe drought. For example, there has been no measurable precipitation in parts of southwestern N.M. in the past three months. The National Weather Service has issued a “red flag warning” for most of N.M and much of western Texas, which means that current weather conditions — high winds, low humidity, and warm temperatures — are perfect for fires. In Texas, 48 percent of the state is currently in the grips of "exceptional" drought conditions — the top category in the U.S. Drought Monitor — and 82 percent of the state is experiencing "extreme or exceptional" drought conditions.

U.S. Drought Monitor showing widespread "extreme" to "exceptional" drought conditions in Texas, as of May 10, 2011. Credit: USDA.

About 150 miles southeast of Tuscon, Arizona, the Horseshoe 2 fire has forced hundreds of evacuations. And in the past week, at least three small communities in southeast N.M. have been evacuated as nearby fires raged out of control.

The current drought in the Southwest is partly an extension of a decade-long span of parched conditions across the region. According to the National Climatic Data Center, however, Texas and some parts of the Southwest have seen above average temperatures and below average rainfall for several months, which has been partially caused by a strong La Niña in the tropical Pacific Ocean. La Niña conditions tend to divert weather systems around the nation's southern tier, particularly during the winter into early spring.  

According to the National Climatic Data Center, so far this spring more than twice as much land has burned across the U.S. than in any other year this past decade. Credit: NCDC.

The warm and dry conditions have intensified the fire risk across the region, and this spring the U.S. has seen well more than double the area burned in wildfires than in any other year this decade.

According to the 2009 Global Climate Change Impacts in the U.S. report, the Southwest region is expected to see an overall decrease in precipitation over the coming century. On the other hand, the upper Midwest region is likely going to experience increased precipitation, which means that flooding along the Mississippi River like that going on this spring, could become more frequent later this century.

The most recent drought outlook issued from NOAA (from May 5) calls for ongoing drought conditions in the Southwest through the end of July. An updated drought forecast will be released later this week, which may provide a more detailed outlook of whether there will be any relief to the dry conditions in the coming months. Some rain is in the forecast during the next five days for parts of Texas, but not in the hardest hit western parts of the state as well as eastern New Mexico.

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