August heat still shows no signs of letting up (click to enlarge)
So What Else is New?
August, Some Summer Temperature Records in Jeopardy

Overview Updated August 17th
Like a broken record, the searing heat continues in Deep South Texas, with no break in sight as we move into late August 2009. While the region is known for its hot and humid summers, the persistence of the heat, relatively gusty southeast winds, and lack of any widespread rain events for most areas since early June remains impressive. Temperature data collected for June through mid August, compared with other similar periods, show most stations in Deep South Texas and the Rio Grande Valley in the top 5 hottest, all time. As of August 16th, McAllen Miller Airport was a full 1°F above its all time average, while Harlingen was in third place. Brownsville, with the longest period of record – more than 130 years – has risen to 7th. 1998 remains the benchmark summer, with June nearly equalling July’s heat in many areas. August temperatures look to break all time records in several locations, ensuring that 2009 will challenge 1998 for heat supremacy in Deep South Texas.

The hot start to the month has changed little during the middle period. Thus far, through August 17th, temperatures were running 2.5°F above average at both Brownsville and Harlingen (86.7°F and 87.7°F, respectively) and 5.9°F above average at McAllen/Miller (92.3°F). At the McAllen Cooperative Observation station, the current June 1 through August 9 average of 89.1°F bests the 1998 record of 88.6°F. At Miller Airport, the 77 day average high temperature at a scorching 101.8°F!

Average Temperatures, June 1st through Aug. 16th (preliminary data)
2009 Average
All-Time Record
McAllen/Miller Arpt. (since 1961)
McAllen/Coop (since 1941)
Port Mansfield (since 1958¹)
Port Isabel (since 1928¹)
Harlingen/Coop (since 1911)
Rio Grande City (since 1900¹)
Falcon Dam (since 1962)
Raymondville (since 1913¹)
Brownsville (since 1871)

¹Data incomplete, especially early in 20th century.
²July 2009 missing 8 or more dates (incomplete)

Pattern Matters...Still
While the position of the strong high pressure system deep in the atmosphere has migrated a bit from its July location, only paltry moisture wafted across the lower Texas Gulf coast between the 12th and 14th, producing isolated heavy storms, mainly on the 13th. The vast majority of the area remained dry. Through August 19th, isolated afternoon storms along the sea breeze will cool some areas off but provide no appreciable drought relief. Unfortunately, a nearly identical pattern that covered the western United States, extending southeast to the Gulf of Mexico east of the Lower Texas Coast, is set to redevelop by August 21st, and continue through at least the 24th, and perhaps to the end of the month. Assuming this occurs, deep tropical moisture needed to produce widespread rains will be limited.

Daily wind averages will be a hair less than in recent weeks. However, afternoon surges of southeast winds gusting up to 25 mph across the extreme to exceptional drought area will maintain a threat for rapid wild fire growth across extremely dry grasses and rangeland.

Expected weather pattern through August 7, 2009

What to Expect? More of the Same
The combination of heat and humidity, particularly near the coast, will make it feel more like 102°F to 108°F each afternoon across most of the area. Evenings will provide little relief as the apparent temperature will remain above 90 until after midnight for areas away from the coast. The potential for heat health related incidents continues, even during this hottest part of the year. Now that autumn scholastic athletic training has begun, and schools have opened or will be opening within the next week across the Rio Grande Valley, persons expected to spend any length of time outdoors are urged to continue following safety tips, below:

  • Slow Down. Schedule strenuous activities early in the morning, if at all.
  • Drink Plenty of Water. For healthy persons, be sure to drink water at all times, even if you are not thirsty. Persons on fluid restricting diets should consult their physicians before increasing consumption.
  • Dress for Summer. Lightweight, light colored clothing reflects heat and sunlight and helps maintain a lower body temperature.
  • Do not Drink Alcohol. Alcoholic beverages increase dehydration rate and could bring on heat stress or heat stroke rapidly.
  • Spend time in Air Conditioning. Cooler locations offer relief and some protection from heat dangers.
  • Avoid Sunburns. Sunburn makes heat dissipation from the body more difficult. As the summer solstice approaches, the angle of the sun reaches its peak, increasing the threat for sunburn in a short period of time.
  • Eat Lighter. Put less fuel on your inner fires. Foods that increase metabolic heat production can also increase the rate of water loss.
  • Never Leave Children Unattended in Vehicles. Not even for a minute! Temperatures rise rapidly inside a car, nearly 30°F in as little as 20 minutes. Click here for more information on children and hyperthermia.
For much more information, go to the National Weather Service's Heat Safety web page.


Drought Stress
According to the Texas A&M Agrilife Extension Service, the current drought continues to affect the production of grains and native rangeland and pastureland. Across the area, the grain harvest is expected to be small; supplemental feeding continues for cattle and other livestock, but losses are piling up as some herds are sold at lighter weight. Other livestock, including goats, sheep, and horses, are also sustaining productivity losses. The situation has become so critical that some herds are being liquidated as the water stocks disappear. Windmills and water wells continued to be used as a main source of water for livestock. Heavy irrigation of corn, sorghum, and citrus was allowing these crops to progress. Dryland crops, such as vegetables, pecans, and horticultural plants are being heavily damaged in some areas; large acreages may end up being a total loss when the harvesting season is complete.

Local wild life is also feeling the effects of the heat and drought. At the Laguna Atascosa National Wildlife Refuge in northeast Cameron County, native animals are having to trek to a cistern system, scattered across the park, to drink water, which lacks a steady supply of irrigation water. Even in parks with enhanced water supplies, the lack of general moisture has reduced the ability of many plants to flower, which in turn reduces the numbers of butterfly species.

Wildfire Growth Potential
Dry to Extremely Dry Fuels will continue across all of Deep South Texas, as drought and heat continue. Moderate afternoon winds gusting in excess of 25 mph combined with marginally low humidity will keep at least an elevated threat for rapid wild fire growth on most days through at least August 16th. Burn bans remain in effect for most counties in Deep South Texas and all of the Rio Grande Valley. Parking vehicles or using grinding or other sparking machinery in grassland is highly discouraged. Residents with further questions about any burning should contact local officials.

Beating the Heat: The Beach
The prolonged heat and abundant sunshine has been a boon to beach goers and the Town of South Padre Island. The upcoming weekend and beyond will provide more super weather for "The Island". The general weather pattern looks to remain benign, with east to southeast winds continuing at 10 to 15 knots and a light to moderate swell which should remain below 6 seconds. Most swimmers should find the pleasantly cooler waters a great way to beat the heat; the rip current risk is expected to remain low through the 24th of August, and perhaps beyond.

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