Perilous
Times and Climate Change
Wildfires Rage, Drought Intensifies in US Southern Plains,
Southwest
Apr 14, 2011 – 9:18 AM
While much of the country has been hit with flooding rain,
dangerous thunderstorms and even late-season snow, just the
opposite in the Southwest and Southern Plains has resulted in a
decidedly different problem: extreme drought and wildfires.
Extremely dry ground and vegetation, very low humidity and strong
winds are fueling numerous fires in eastern New Mexico, western
and northern Texas and Oklahoma.
More than 360,000 acres of land have been burned nationally by
ongoing fires this week, according to the National Interagency
Fire Center. More than 900,000 acres have been burned so far this
year, which is roughly one-third more than the 10-year average to
date.
Fire weather conditions will be "extremely critical" in parts of
eastern New Mexico and the Texas panhandle today and Friday,
according to the National Weather Service. Relative humidity
levels will be dip to between 10 and 15 percent today, with wind
gusts of close to 60 mph, resulting in a short-term
intensification of what's been a long-term problem.
Not only has little or no precipitation fallen so far this month
-- at a time when the strengthening sun has increased the rates of
evaporation and evapotranspiration (the loss of moisture to the
air from vegetation) -- but precipitation amounts since the fall
have been far below normal. Southern New Mexico, as well as
western and southern Texas, has had less than 25 percent of
average precipitation since October.
This translates to less than 2 inches of total rainfall in nearly
half a year for many locations. To put that in perspective, a
single heavy thunderstorm sometimes produces that much rain in an
hour.
The result is long-term drought conditions that are extreme to
exceptional, the worst category, and the intense drought extends
eastward through the remainder of Texas into large portions of
Arkansas and Louisiana.
One of the long-term weather factors that has contributed to the
lack of storminess is the La Nina, which is a cooling of
sea-surface temperatures in the equatorial Pacific. One of the
more common effects of a La Nina across the United States during
the winter through spring is a less-active-than-normal southern
storm track, often resulting in dry conditions across much of the
southern U.S.
No immediate relief is in sight.
The Climate Prediction Center, which produces the government's
long-range forecasts, predicts higher-than-average chances of
below-normal precipitation in the Southwest through June. In
addition, temperatures are projected to be higher than normal,
which would increase the amount of moisture pulled out of the
ground and vegetation.
The possibility of worsening drought conditions across the
southern tier of the county was highlighted in seasonal forecasts
in the fall because of the expected impact of La Nina; however,
drought conditions were not as widespread as they could have been.
Winter storms tracked far enough to the south along the West Coast
to bring an abundance of rain and mountain snow to California,
including the southern part of the state.
Gov. Jerry Brown officially declared the California drought to be
over a couple of weeks ago, two years after former Gov. Arnold
Schwarzenegger's drought designation.