The latest weather trends for Deep South Texas, late April 2011 (click to enlarge)
Weather and drought conditions as of the last week of April, 2011.
Expected general weather trends for Deep South Texas, May 2011 (click to enlarge)
Potential weather evolution for Deep South Texas, May, 2011. Little change from Early April, at least for the first half of the month: Winds will continue to be frequently strong; hot temperatures will continue as one or two dryline "fronts" are left. The speedy track of low pressure systems will continue well north of the area.
Late Spring 2011 Outlook for Deep S. Texas/Rio Grande Valley:
Update: Hot and Dusty: Drought, Wildfire Danger to Worsen Further

Updated Main Points (end of April)

  • Weak La Niña will continue into May, but is expected to become neutral in June.
  • April is expected to set new records for heat across Deep South Texas. No rain is expected to fall anywhere by month’s end. For brief local details through the 18th, click here.
  • Historical trends strongly suggest continued low to very low area wide rains through at least the first half of May, persistent winds, and a few but more intense dryline "fronts". Click here for charts showing rainfall differences between La Niña and average.
  • High pool levels at Falcon International Reservoir through early spring are now falling steadily, and will continue to do so until significant rains arrive along the front range of the Sierra Madre.
  • More than a dozen drying fronts between October and early January, followed by a significant February Freeze left grasses and brush highly cured...
  • ...though some greenup began toward the end of February in Cameron through Kenedy County, where mid January heavy rainfall and late February warmth and humidity helped soften soils.
  • This greenup was short lived. Across the Lower Rio Grande Valley to the King Ranch, April’s persistent heat, lack of rain, and dry fronts which brought humidity below 10 percent in many areas returned cured fine fuels by mid month.
  • The threat for explosive wildfire growth has expanded to all but the immediate coast.
  • May will begin with more of the same pattern as heat builds. Uncertainty remains as La Niña trends toward neutral and primary storm tracks shift farther north...
  • ...which may allow fronts to become stationary over the Valley for the second half, providing lift for scattered thunderstorms, and easterly waves of tropical moisture to possibly bring welcome rainfall in June.


Statistical correction of the Climate Forecast System model prediction for the Nino 3.4 Sea Surface Temperature region of the equatorial Pacific (click for more)
Statistical Correction of the Climate Forecast System Forecast for the Niño 3.4 Sea Surface Temperature Anomalies in the eastern equatorial Pacific. Six consecutive months of values above +0.4 signify El Niño; six consecutive months of values below -0.4 signify La Niña.
Expected general weather trends for the United States, early spring 2011, based on prior moderate to strong La Nina (no other considerations included) (click to enlarge)

Preparing/Decision Making
While predicting specific weather events such as cold fronts, severe weather outbreaks, rain, and windstorms more than a week or two out is beyond the scope of sound science, the high confidence for a continued rain–starved Rio Grande Valley and Deep South Texas through May requires persons tasked with agricultural and rangeland responsibilities to maintain high awareness for wildfire growth and drought dangers. It is always a good time to revisit plans to move people and equipment efficiently to wildland or urban/wildland interface fires. Growers and ranchers should ready for irrigation efficiency and water conservation that will become reality later this spring. As always, continue to monitor information on our website, including the RGV Drought Page through the remainder of spring 2011 including the latest "Droughtlooks", rangeland fire danger statements, Fire Weather Watches and Warnings, and Wind Advisories or Warnings. Weather Decision Support is part of our mission, and we’re here to help, 24 hours a day, 365 days a year.

Box and whisker chart of February through April rainfall for El Nino, Neutral, and La Nina seasons, U.S. climate region 63 (Deep S. Texas) (click to enlarge)
Box and whisker chart of April through June precipitation distribution for climate division 63, Deep South Texas, El Niño, Neutral, and La Niña. Lines at either end of each ’whisker’ represent the 10th and 90th percentile; the box represents the 33rd through 67th percentile, with the red line the 50% level. For full details, click here for much more.
Only You Can Prevent Wildfires

The Texas Forest Service offers the following tips, known as the "Three E’s of Wildfire Prevention"

  • Education. Wildfire prevention efforts target a wide variety of audiences using a broad mix of messages, publications, activities and programs. Smokey Bear, the national symbol for wildfire prevention, has reached millions of children, youth and adults with his wildfire safety message: “Only you can prevent wildfires.” The Smokey Bear wildfire prevention campaign remains one of the most successful public service programs ever undertaken by the National Advertising Council.

    Using materials and presentations appropriate for different audiences, fire prevention educators take wildfire safety programs to schools and youth groups, civic clubs, landowner associations and other targeted groups. Fire safety professionals also enlist the help of the news media to educate the public about wildfire danger, fire prevention and home fire safety practices, and weather events likely to increase the risk of wildfires. Fire risk assessment personnel help keep governmental leaders informed on wildfire activity and current and predicted danger levels to enable these officials to make informed decisions about possible outdoor fire restrictions and fire use.

    Even if burn bans are not in effect, open air debris or trash burning is not recommended this December.
  • Engineering. Proper equipment maintenance can help prevent many wildfires, e.g. keeping mufflers and spark arresters on outdoor power equipment in proper working order. Modifications on equipment and/or the environment in which equipment is being used also can prevent wildfires. Examples include removing vegetation from the area in which welding operations will be conducted and physically shielding potential ignition sources from dry vegetation.
  • Enforcement. The enforcement side of wildfire prevention involves activities that encourage compliance with restrictions on outdoor fire use, usually based on penalties for noncompliance with state or county regulations. In Texas, enforcement efforts most commonly involve citations for negligence with outdoor burning, and violations of county burning bans.

    A burn ban doesn’t have to be in effect for outdoor burning to be illegal. Negligently allowing your fire to escape onto someone else’s property is also Class C misdemeanor offense (the same as violation of a burn ban) that is punishable by a fine up to $500. Deliberately setting fire to someone else’s property is arson, which is a felony offense punishable by a fine of up to $10,000 and a prison term of from 2 years to 99 years in prison.


What About Flooding?

Given the circumstances described above, there is a below average probability of significant spring flooding across the Rio Grande Valley, including tributaries and reservoirs feeding the Lower Rio Grande. For current river stage information, check out our Advanced Hydrological Prediction Service site. Specific details on Falcon International Reservoir can be found here. Though area wide spring rain totals are expected to be low, there remains the possibility for localized torrential rainfall and flooding during individual events such as slow moving thunderstorms or repeated rains from upper level disturbances. Stay flood safe year–round by frequenting our flood safety webpage.

Most recent three month long lead outlook, temperature departures from average
Current three month temperature outlook for the U.S. "Valid NDJ" means November through January. "Valid DJF" means December through February, etc.
Most recent three month long lead outlook, precipitation departures from average
Current three month precipitation outlook for the U.S. "Valid NDJ" means November through January. "Valid DJF" means December through February, etc. is the U.S. government's official web portal to all federal, state and local government web resources and services.