| Basin: | atl |
| Winds: | 207to |
| Fujita-Scale: | F4 |
| Deaths: | 1[1] |
| Injuries: | 6 |
| Damages: | $1 million (1999 USD) |
| Affected: | Mason County, Texas near Loyal Valley |
| Season: | tornado outbreaks of 1999 |
During the afternoon of May 11, 1999, a violent, multiple-vortex tornado struck areas around the community of Loyal Valley in Texas, killing one person. The tornado, rated a high-end F4 on the Fujita scale,[1] caused extreme damage along its relatively short path. Meteorologist Bill Hecke of KNCT-FM stated the tornado's intensity rivaled the Bridge Creek–Moore F5 tornado, which had struck Oklahoma a week prior, and the 1997 Jarrell F5 tornado.
The tornado touched down 9miles northwest of Loyal Valley near the Llano River. The National Weather Service (NWS) office in San Angelo noted that this was an extremely slow-moving tornado, which tracked approximately 7miles.[1] Along the path, two homes were obliterated, with debris being scattered "great distances".[1] [2] At one of the destroyed homes, a person was killed and five others were injured after they took shelter in a car, which was located in a stone garage. As the tornado destroyed the house, the car was smashed, resulting in the casualties.[1] Parts of a pickup truck at one of these homes was thrown 0.75miles from the house.[1] At times, the tornado's width grew to 0.75miles wide. Sixteen other homes sustained damage, along with the complete destruction of several barns and outbuildings.[1] As the tornado crossed Farm-to-Market Road 152, a 720feet stretch of asphalt was ripped off the road surface.[1] In total, the tornado killed one person, injured six others, and caused $1 million (1999 USD) in damage as it traveled at an average forward speed of 10mph.[1] [3] [4]
A reporter said: "I hadn't seen anything like that. I couldn't believe what it did to animals. This was wiped clean, too, but the cattle – their hides had been ripped right off of them. Some of them were missing heads, and some were caught up and entwined in barbed wire." Meteorologist Bill Hecke opined that the tornado was capable of devastation comparable to that suffered by Oklahoma City in the Bridge Creek–Moore tornado or by Jarrell in the 1997 tornado.[5]
In 2023, the NWS office in San Angelo stated this was the strongest tornado ever recorded in their forecasting area and that "considerations were made for an F5 rating". However, the survey found that the structures impacted were not built well enough to ultimately warrant the F5 rating.[6]