Wednesday, March 19, 2014

Dusty Days in West Texas

While the eastern half of the country deals with lingering winter weather, the dry, warm conditions in the western U.S. are creating problems there.  It was a dry winter throughout the Southern Plains and southwest, especially from the Texas Panhandle west to eastern California and southern Nevada.  In much of this region precipitation over the past 90 days has ranged from less than 10 to about 50 percent of normal.

Credit: NOAA Advanced Hydrological Prediction Service
 As you may expect, drought continues to persist with the lack of rain. Much of the Texas Panhandle is depicted in Extreme to Exceptional Drought on the U.S. Drought Monitor.

U.S Drought Monitor for March 11, 2014. Red areas are in Extreme Drought, dark red in Exceptional drought.

View looking north on 19th St. in Lubbock, TX on March 18.
Photo credit: Alex Pham
Dry, dusty soils and the windy weather of spring often combine to produce a lot of blowing dust inthe Plains.  Western Texas has experienced two dust storms, or haboobs, in the past week.  One occurred last Tuesday, March 11, and another one yesterday. The  one yesterday developed as a strong cold front moved through the Panhandle.  One interesting aspect of this dust storm was that it was clearly visible on radar.  Here is a radar image at 2:56 p.m. CDT on March 18. What looks like a precipitation echo (in green and blue) is actually the dust cloud.

Radar image of Texas dust cloud on March 18, 2014.

Here is a satellite image about two hours later. The lower sun angle provides better contrast for seeing the dust clouds (outlined in yellow).  The southern dust cloud is occurring just behind the cold front boundary and originated in eastern New Mexico. The northern dust cloud developed along the leading edge of the much cooler air and a wind shift to the north. This is the huge dust cloud, or haboob, that swept across the Panhandle.Winds were regularly gusting 35 to 45 mph with some gusts exceeding 60 mph. Visibilities were reduced to 1/4 mile or less with near "brownout" conditions.

The leading edges of two dust clouds are evident in this visible satellite image.
Surface weather observation plot with the approximate position of the cold front (southern blue line) and the wind shift associated with the cold air and the wall of dust (northern blue line)

The National Weather Service in Lubbock, TX has a web page describing this event along with more photos and animations.  They also have more information on the dust storm on March 11, 2014.
The Texas Mesonet also has a page describing these two dust storms..

No comments:

Post a Comment