Withering Drought continues into mid June, 2011, across the Rio Grande Valley

Mid June weather trends: Summer heat, drought continue (click to enlarge)

Mid June: Withering Drought Continues
100° Heat and No Rain Lock Down Water Year Records So Far

The Situation
A persisting ridge of high pressure through the depth of the atmosphere centered from Texas through northern Mexico had anchored a dry, hot airmass across Deep South Texas and the Rio Grande Valley for the tail end of May and the first half of June. The dry ground and dry atmosphere allowed surface temperatures, particularly during the daytime, to remain some 3 to 6 degrees above already hot seasonal averages, as solar energy went straight into heating with virtually no soil moisture to speak of. The depth and breadth of the ridge, combined with now warm Gulf waters, reduced both the surface pressure and temperature differences and kept wind speeds at a fresh breeze, rather than the roaring 30 to 40 mph winds that closed May. Low humidity for the most part kept heat index values in check, between 98 and 104°F – very close to the actual air temperature.

Drought continued at the highest levels possible, ranging from extreme (D3) across the Brush Country and King Ranch to exceptional (D4, highest on the scale) throughout the Rio Grande Valley. Wildfire growth potential will remain severe to extreme, with afternoon humidity ranging from 20 to 30 percent inland. Lower wind speeds help reduce the spread, but only a little bit. Burn bans remain in effect for most of the Valley.

Just How Dry Compared with Other Years?
The map above shows a continuation of the current water year (since October 1, 2010) record dry. Just how far below the previous record are most of these locations at, as of June 13th, 2011? The following table tells the tale.

Current Rainfall Compared with Prior Records
Location	Current Rainfall (Rank)	Prior Record (year)
Brownsville	2.97 (1)	5.29 (1902/03)
Harlingen/Coop	4.49 (1)	5.48 (1915/16)
Raymondville	4.78 (3)	3.51 (1970/71)
Port Mansfield	2.65 (1)	2.96 (2008/09)
Sarita	6.54 (6)	2.95 (2008/09)
Hebbronville	3.44 (1)	3.71 (2007/08)
Falcon Dam	1.03 (1)	1.76 (1970/71)
Rio Grande City	1.47 (1)	2.76 (1970/71)
La Joya/Mission	0.89 (1)	4.16 (2007/08)
Mc Cook	1.21 (1)	3.13 (2005/06)
McAllen/Miller Arpt	1.47 (1)	3.74 (2005/06)
Mercedes 6 SSE	2.97 (1)	4.59 (2008/09)

Stay Safe...in a Number of Ways

Heat Safety::
- Drink Plenty of Water, even if you’re not thirsty.
- Take Frequent Breaks if working outdoors. Save strenuous work or excercise for the early morning or late evening
- Wear lightweight, light colored, and loose fitting clothing.
- Heat sensitive persons should remain in air conditioned buildings if at all possible
- Wear sunscreen and a hat to protect from extreme ultraviolet rays, which are peaking
- On June 11th, an 18 month old girl perished from heat stroke after being left in a vehicle. Ensure that young children and pets are taken out of vehicles. Don’t let your family become victims. Beat the heat, check the backseat!
Fire Weather Safety::
- Continue to cut grass and brush to very low heights, including areas where last week’s rains may have sprouted new growth
- Refrain from using welding or grinding equipment in high grass or brush
- Park vehicles on dirt or paved areas; hot catalytic converters often produce sparks which can quickly ignite a rapidly growing grass or brush fire.
- Use vehicle ash trays to dispose of cigarette butts.
- Burn bans remain in effect for most of the Rio Grande Valley. Check with local authorities for additional details.
Rip Current Safety::
Beach weather doesn’t get much better than this. Still, though a low to moderate risk for rip currents is expected for most days through the next week or so, poor swimmers should remain in water no higher than waist deep, and experienced swimmers should consider bringing a flotation device such as a boogie board into the surf if planning to stay in for awhile. Currents are generally highest around the Boca Chica/Isla Blanca jetties (Isla Blanca Park) and at the public beach access points from Andy Bowie Park northward. Beat the heat safely when entering the surf.

For much more, check out our Preparedness Page.

Departure from average rainfall, Deep South Texas, October 1 through June 13 2011 (click to enlarge)

Above: Water year departures as of June 13th 2011 (since October 1, 2010) from average rainfall for Deep South Texas.