Late May weather trends:  No letup with steam heat, wind (click to enlarge)
Helter Skelter, Late May Swelter
Heat, Fire, Other Dangers Continue as Late April Pattern Resets

The Situation
If you thought most of April was impressively hot, then most of the last ten days of May will actually feel even hotter in many areas. The combination of a flat upper level high pressure ridge and a continued fast storm track across the northern half of the U.S. has led to persistent and frequently strong southerly flow across Deep South Texas. Lack of deep moisture, due to subsiding (sinking) air around the atmospheric high pressure system, will result in virtually nil rain chances through at least May 26th, and likely carrying through to the end of May. The early month respite from heat and humidity, followed by a five day period which featured some rainfall, was just a memory as of May 18th. The return of heat along with paltry long term rainfall trends – and, for those near the Rio Grande beteen McAllen and Falcon Heights (at the south end of Falcon Lake), virtually no rainfall since October, exceptional drought and extreme wildfire growth potential continues. The animated map below shows the national trend of weather systems through May 25th.

Stay 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
    • Beat the heat, check the backseat! Ensure that young children and pets are taken out of vehicles
  • 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:
    A moderate to high risk for rip currents is expected for most days through the rest of May. Poor swimmers should remain in water no higher than knee deep, and even experienced swimmers should venture into the surf no higher than waist deep. Currents are 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 very cautiously if entering the surf through the end of May.


For much more on these and other hazards, check out our Preparedness Page.

Late May weather pattern across the United States, 2011
Above: Atmospheric and surface weather patterns, animated, from May 20th through May 22nd, 2011. White curves indicate mid level, or "storm track", flow. Storm system motion from the Central Plains through the Ohio Valley combined with tight lines to the south will keep rainfall and even slightly cooler temperatures from reaching the Valley. is the U.S. government's official web portal to all federal, state and local government web resources and services.