WFO San Angelo Climatology

May 2013 Weather Highlights for West-Central Texas

The rollercoaster pattern in temperatures (from April) continued into the first few days of May. With the exception of the northern Big Country, high temperatures were in the 90s on the 1st.

With the approach of a strong cold front into a rather unstable airmass, numerous strong to severe storms occurred during the evening and nighttime hours of the 1st. Most of the severe storms were in the Big Country and Concho Valley. Significant wind damage occurred in Albany (Shackelford County), with roofs blown off of a factory and a house. In addition, multiple large trees and power lines were blown down. Abilene Regional Airport recorded a peak wind gust of 47 mph. The largest hail of golfball size was reported one mile south-southwest of Echo (Coleman County). The below radar animation (Figure 2) shows the development and coverage of storms between 7 PM and 11 PM, on May 1st.

Figure 2: Animated National Weather Service San Angelo Radar Imagery, for May 1.

A number of storms contained heavy rain. Rainfall amounts of 1-2 inches (with a few locally higher amounts) occurred at scattered locations, mainly across central and southern sections of west-central Texas.

Much cooler air invaded the region behind the strong cold front, accompanied by gusty north winds. A peak wind gust of 45 mph was recorded at Abilene. With extensive cloud cover, daytime temperatures only reached the upper 40s to mid 50s on the 2nd. These temperatures were 35-45 degrees colder than on the previous day. As an unusually strong high pressure system settled south into western Texas, clearing skies allowed temperatures to dip into the 30s, for early morning lows on the 3rd. The low temperature of 33 degrees at Abilene and 35 degrees at San Angelo were not only records for that date, but also tied the record low temperatures for the month of May. At four cooperative observer locations in west-central Texas, low temperatures at or below 32 degrees were reported. This likely was the latest freeze on record for those locations.

Temperatures rebounded quickly, and highs were mostly in the upper 70s to lower 80s on the 4th.

Light rain showers occurred on the 6th with the arrival of a weak upper level disturbance. Rainfall at some locations across the southern Big Country, northern and western Concho Valley, was between one tenth and one quarter of an inch.

A cluster of thunderstorms dissipated after moving east into the northwestern Big Country, during the overnight hours of the 7th and 8th. Parts of Fisher County received between one quarter and three quarters of an inch of rainfall.

With the approach of a dryline into a very unstable airmass, a few thunderstorms developed in northwestern Texas on the 8th, and became severe. One of the severe storms tracked east across northern Fisher and Jones Counties during the evening hours. In Fisher County, the storm produced golfball to baseball size hail 1-2 miles north of Rotan, and a funnel cloud was reported 8 miles east of Rotan. In Jones County, this storm was prolific in producing hail. Quarter to golfball size hail was reported in Hamlin, with enough hail to cover the ground. Hen egg and tennis ball size occurred with this storm just north and northwest of Anson, with golfball size hail in the town of Anson. This large hail covered the ground.

The below radar animation (Figure 3) shows the development and track of storms between 4:15 PM and 8:15 PM, on May 8th.

Figure 3: Animated National Weather Service San Angelo Radar Imagery, for May 8.

Another storm dissipated while tracking east into Haskell County. One half to one inch of rainfall occurred with the storm in Fisher and Jones Counties.

May 9th was very active with thunderstorms in west-central Texas. This occurred as upper level disturbances moved northeast into Texas and interacted with moist and increasingly unstable air. Later in the day, a cold front approached the area from the north, while a dryline approached from the west. Showers and thunderstorms with heavy rain occurred on the morning of the 9th, primarily across the Concho Valley and Heartland areas. One of the storms produced quarter size hail in Brookesmith (Brown County).

Strong to severe thunderstorms affected the northern half of west-central Texsas during the afternoon. Additional strong to severe thunderstorms affected the southern half of west-central Texas during the evening and early nighttime hours. Most notable were 2 fairly long-track supcercell severe storms.

In Nolan County, large hail to golfball and hen egg size was reported around Sweetwater. Quarter to walnut size hail was also reported with this storm in northern and northeastern Nolan County. In western Taylor County, quarter size hail was reported from this storm (8 miles east-northeast of Nolan).

One of the supercell severe storms moved east across the northern half of Coke County, and then tracked southeast across Runnels and the southern half of Coleman counties. The radar animation in Figure 4 (below) shows the track of this supercell storm.

Figure 4: Animated National Weather Service San Angelo Radar Imagery, for May 9 (between 3:15 PM and 6 PM).

This storm produced quarter to golfball size hail in Coke County. In Runnels County, this storm produced golfball and hen egg size hail near Hatchell, and golfball to baseball size hail 3 miles north-northeast of Ballinger. A couple of utility poles and power lines were blown down on the west side of Ballinger. In Coleman County, golfball size hail was reported 6 miles southeast of Voss, and baseball size hail was reported in Gouldbusk.

Another of the supercell severe storms tracked southeast, from southwestern Concho County across Menard and Mason Counties. The radar animation in Figure 5 (below) shows the track of this supbercell storm.

Figure 5: Animated National Weather Service San Angelo Radar Imagery, for May 9 (between 5:45 PM and 9 PM).

In Coleman County, ping-pong ball size hail was reported from this storm, 2 miles west of Live Oak. This storm produced golfball size hail 6 miles north-northwest of Menard, and 1 mile north of Menard. This caused damage to numerous cars along U.S. Highway 83. The largest reported hail with this storm was baseball to softball size, 5-7 miles east of Menard. Tennis ball size hail was reported at Hext. In Mason, this storm produced golfball to billiard ball size hail 9 miles south-southeast of Mason. Car windows were broken by hen egg size hail in western Mason County (2 miles east-northeast of Erna). Near the town of Mason, strong winds blew a police car off of Rural Route 783.

Another severe storm produced quarter to golfball size hail in Menard County. The track of this storm is also shown in Figure 5, between 7 PM and 8:15 PM.

In all, a total of 39 severe weather reports were received for the May 9th event.

With an upper level disturbance lifting northeast across the region, numerous showers and thunderstorms also occurred on May 10th. Severe weather (large hail and damaging winds) occurred with a supercell storm which was along a cold front, as the front tracked southeast across central sections of west-central Texas. The radar animation in Figure 6 (below) shows the track of this supercell storm.

Figure 6: Animated National Weather Service San Angelo Radar Imagery, for May 9 (between 2 PM and 4:45 PM).

The largest hail was ping-pong ball size, which was reported 12 miles southwest of Ballinger and at Rowena (Runnels County), and 2 miles southeast of Voca (Mcculloch County). Telephone poles were blown down along U.S. Highway 67 in Runnels County, 4 miles east of Rowena. In addition, a 6-inch diameter tree limb was blown down along U.S. Highway 83 in Runnels County, 10 miles north of Paint Rock.

Most locations across west-central Texas received rainfall on May 9-10. This rainfall was of some short-term benefit to the region.

Dry weather with cool nights and pleasant daytime temperatures occurred on May 11-12. Temperatures were warmer on the 13th and 14th, with an increase in moisture across the area on the 14th.

As a larger upper level disturbance lifted northeast into Texas, a large area of showers and thunderstorms developed and move east across west-central Texas, from the late evening of the 14th into the post-Midnight hours of the 15th. The heavier rainfall (one half to one inch with locally higher amounts) occurred across much of the Concho Valley. This rainfall was of some short-term benefit to the Concho Valley. Figure 7 (below) shows rainfall amounts across west-central Texas, for the 24-hour period ending at 7 AM on May 15th.

Figure 7: West-Central Texas Rainfall for the 24-hour period ending at 7 AM, May 15.

Another severe weather event occurred on the 15th, mostly across the Big Country and Heartland areas. As a strong upper level lifted northeast into western Oklahoma, another disturbance moved southeast into Texas from New Mexico. A dryline advanced east across western sections of west-central Texas. Another surface boundary was aligned north-northeast to south-southwest, across the far eastern part of west-central Texas. This setup, along with very unstable air ahead of the dryline, set the stage for thunderstorm development. Thunderstorms initially developed across the Big Country during the afternoon. An isolated storm affected far southeastern Brown County during the early evening. Thunderstorms developed south into the northern Concho Valley late in the evening. Between 10 PM and Midnight, a band of storms moved south across parts of the Heartland. A number of storms were severe.

National Weather Service Weather Forecast Office