Rains come to Texas but drought could last for years

Peter Aldhous, San Francisco Bureau Chief

Parts of scorched and parched Texas got as much rain over the weekend as has fallen all summer? - bringing some relief from the most severe single-year drought on record for the state.

But much more rain will be needed to end the drought, and climatologists fear that conditions are still ripe for a lengthy arid period, possibly exceeding the prolonged drought that plagued the state from 1950 to 1956.

The map below shows the situation at the end of September, when almost all of Texas was judged by the National Drought Mitigation Center at the University of Nebraska-Lincoln to be experiencing "exceptional drought". The markers show monitoring stations contributing to the Global Historical Climatology Network; click on them to see how this year's rainfall compares to historical averages.
?

(Source: Global Historical Climatology Network/National Drought Mitigation Center)

Over the past 12 months, Texas has received about 40 per cent of its usual rainfall, but this has not been the only problem. As temperatures have soared this summer, what little rain has fallen has tended to quickly evaporate.

This weekend's storms were caused by a low-pressure system moving from west to east across the state. Some of the heaviest downpours came in central Texas: Llano is reported to have received almost 16 centimetres overnight on Saturday.

The National Weather Service predicted on Friday that some areas could get more than 25 centimetres over the weekend. That's a huge amount of rain, but even these deluges will leave Texas chronically short of water. According to the National Oceanic and Atmospheric Administration's Climate Prediction Center in Camp Springs, Maryland, some 40 centimetres of rain would have to fall to bring much of the state out of long-term drought. The bad news for Texans is that conditions in the Pacific and Atlantic oceans suggest a return to drought.

What's more, John Nielsen-Gammon of Texas A&M University in College Station, the official state climatologist, warns that dry conditions could persist for a decade. Nielsen-Gammon explains that a La Ni?a, when surface waters in the eastern equatorial Pacific are cooler than normal, is now forming once again. At the same time, the Atlantic is in the warm phase of a cycle called the Atlantic Multidecadal Oscillation.

Together, these conditions conspire to make Texas unusually dry. "The last time they were lined up against us like this was the 1950s," says Nielsen-Gammon.

Source: http://feeds.newscientist.com/c/749/f/10897/s/192b2e00/l/0L0Snewscientist0N0Cblogs0Cshortsharpscience0C20A110C10A0Ctexas0Erains0Etoo0Elittle0Etoo0Elat0Bhtml0DDCMP0FOTC0Erss0Gnsref0Fonline0Enews/story01.htm

lightsquared jane lynch matt ryan matt ryan ricky gervais golden globes real housewives of new york justified