National Weather Service United States Department of Commerce

South Texas High Wind Event from a Gravity Wave - April 9, 2015

A meteorological phenomenon called a "gravity wave" affected portions of South Texas during the early monrning hours on April 9, 2015. It originated from thunderstorms over the Sierra Madre which developed during the evening hours on April 8, 2015. Wind gusts between 30 and 50 mph were observed from Laredo to Bob Hall Pier between 1137 PM on April 8th through 330 AM on April 9th. The strongest winds occurred in Laredo, Kingsville, and Bob Hall Pier where all 3 stations reported 50 mph wind gusts. Both Corpus Christi International Airport and the Navy Base in Corpus Christi reported wind gusts of 40 mph between 211 AM and 314 AM on April 9th.

Location Peak Wind Gust Time of Wind Gust
Laredo 50 mph 1137 PM (4/8)
Alice 38 mph 126 AM (4/9)
Hebbronvile 36 mph 135 AM (4/9)
Corpus Christi International Airport 40 mph 211 AM (4/9)
Corpus Christi Marina 38 mph 230 AM (4/9)
Corpus Christi Bay 39 mph 236 AM (4/9)
Kingsville 50 mph 247 AM (4/9)
Navy Corpus 40 mph 314 AM (4/9)
Bob Hall Pier 50 mph 324 AM (4/9)
South Bird Island 36 mph 330 AM (4/9)

Radar observations (see image below) indicated that winds at around 1100 feet above ground level were hurricane force strength at more than 85 mph with a few very small areas close to 120 mph just south of Chapman Ranch. Pressure falls associated with this gravity wave averaged 3-5 millibars which is quite intense. Temperatures even warmed 1-3 degrees as the warmer air aloft mixed down to the surface due to the strong winds. Winds finally subsided once an outflow boundary pushed past the region. This outflow boundary also originated from previous thunderstorms over Mexico the day before.

Velocity loop of 1100 foot AGL winds between 156 AM CDT and 504 AM CDT April 9, 2015