March 2013 Weather Highlights for West-Central Texas
Precipitation for March was well-below normal across much of west-central Texas. For much of the Concho Valley, much of the Northern Edwards Plateau west of Highway 277, parts of the Big Country, part of Coleman and a small part of Menard Counties, the monthly amounts were less than one tenth of an inch. This was less than 10 percent of normal precipitation for March (Figure 1).
Figure 1: Percent of Normal Precipitation for March, 2013.
The only area with above normal March precipitation was in an east-west band across central Nolan County. The higher monthly precipitation amounts (between 1.5 and 2.5 inches) occurred in the east-west band in Nolan County, and at scattered locations across the eastern Heartland and Northwest Hill Country.
Temperatures averaged above normal for the month.
At Abilene Regional Airport, the average temperature for March was 57.7 degrees. This was 1.3 degrees above the normal average temperature of 56.4 degrees. Total precipitation for Abilene in March was 0.61 inches. This was 1.13 inches below the normal of 1.74 inches.
At San Angelo Regional Airport, the average temperature for March was 60.8 degrees. This was 3.0 degrees above the normal average temperature of 57.8 degrees. Total precipitation for San Angelo was only 0.01 inches. This was 1.49 inches below the normal of 1.50 inches. * This marks the 6th driest March on record for San Angelo. *
No daily record high, record low, record high minimum, or record low maximum temperatures were set or tied at Abilene or San Angelo during March.
Gusty north winds followed passage of a cold front on the 1st. A peak gust of 41 mph was recorded in Abilene.
Warm and very dry conditions occurred on the 3rd, with gusty south-southwest winds. Afternoon highs were in the upper 70s to lower 80s across most of the area, with minimum relative humidity values in the 9-12 percent range. Temperatures were even warmer on the 4th, with somewhat gusty southwest to west winds. Highs on the 4th were mostly in the 80s with minimum relative humidity values between 5 and 10 percent.
Another dry cold front advanced south across west-central Texas during the overnight hours of the 4th and 5th. Gusty north winds followed this cold front as well, and were accompanied by much cooler air. Peak wind gusts exceeded 40 mph at a number of locations across west-central Texas (Figure 2). Recorded peak wind gusts included 52 mph at the Abilene Regional Airport, and 43 mph at the San Angelo Regional Airport.
Observations from automated weather stations.
Coleman 2 ENE
Haskell 1 NW
Sterling City 4 WSW
Sweetwater 4 W
Wall 1 E
Ozona 2 N
San Angelo 7 NW
Sonora 2 NNW
Brownwood 7 NNE
Junction 1 N
Mertzon 3 NNE
Junction 1 SSW
Figure 2: Peak Wind Gusts on March 5th.
Observations from automated weather stations.
Temperatures were 20-30 degrees cooler on the 5th, across most of west-central Texas.
South winds on the 7th and 8th brought an increase in moisture from the Gulf of Mexico, well out ahead of a developing upper level storm system over the western United States. Gusty south winds continued on the 9th, as this system approached from New Mexico. Abilene recorded peak wind gusts of 41 mph on the 8th, and 40 mph on the 9th.
A significant severe weather event occurred across the Heartland and Northwest Hill Country areas, on the late afternoon and evening of March 9. As the upper level storm system began to lift northeast into the Plains states from New Mexico, a Pacific cold front moved east across much of west-central Texas during the daytime hours. Gusty southwest to west winds brought an intrusion of very dry air occurred behind this cold front. This affected the western Big Country, Concho Valley, and Crockett County. The Pacific cold front stalled across the Heartland and Northwest Hill Country areas, before being overtaken by a second cold front from the north late in the day. With this setup and an unstable airmass, numerous severe thunderstorms occurred southeast of a line from Brownwood to Sonora.
The below radar animation (Figure 3) shows the development and coverage of thunderstorms, between 5 PM and 10 PM CDT, on March 9. The border for the National Weather Service San Angelo forecast and warning area is denoted by thick, black lines on the pertinent county borders.
Figure 3: Animated National Weather Service San Angelo Radar Imagery, for March 9.
All of the severe weather reports were for large hail, ranging from quarter to golfball in size. A wall cloud and funnel cloud were spotted just northeast of Erna, in far western Mason County. In all, a total of 30 severe weather reports were received for this event.
Locally heavy, but beneficial rainfall occurred across the same area which experienced the severe weather (Figure 4).
Figure 4: Rainfall for the 24-hour period, ending 7 AM CDT, on Sunday, March 10, 2013.
Rainfall amounts between one half and 1.5 inches occurred across the area southeast of a line from Cross Plains to Sonora. The heaviest rainfall (between 1.5 and 3 inches) occurred at a few locations within this area.
In the wake of the secondary cold frontal passage on the 9th, temperatures were much cooler (15-20 degrees cooler) on the 10th, and were accompanied by gusty north to northwest winds. Abilene recorded a peak wind gust of 49 mph.
Dry airmasses occupied the region on March 11-13, with a weak, dry cold frontal passage on the 12th. The combination of dry air and clear skies resulted in large daily temperature ranges (30-45 degrees) between the early morning lows and afternoon highs, on the 11th and 13th. Increasing south winds occurred on the 14th and 15th. Abilene recorded a peak wind gust of 43 mph on the 15th.
Temperatures were well-above normal on the 15th and 16th, with very dry conditions. Afternoon highs were in the 80s on the 15th, and in the upper 80s to lower 90s on the 16th. The high of 90 degrees at Abilene was just one degree short of the record high for the 16th. Afternoon relative humidity values dropped into the 15-20 percent range across far eastern sections of west-central Texas, and into the 5-15 percent across the rest of the area.
Scattered showers and a few thunderstorms occurred across parts of the Heartland and Northwest Hill country, near a stationary front, on the late afternoon and evening of the 19th. percent across the rest of the area. For most of the locations which received rainfall, the amounts varied under one half inch. The heavier rainfall amounts of one half to one inch occurred in parts of eastern San Saba County.
A large north-south temperature contrast developed on the 22nd, as a cold front moved south across west-central Texas. Temperatures were much cooler across the Big Country, where cloud cover persisted through the day. Temperatures were warm along the Interstate 10 corridor, where the front arrived later in the day. By late afternoon, temperatures ranged from near 50 degrees across the Big Country, to the lower 80s along the Interstate 10 corridor.
As an upper level disturbance moved east into Texas, scattered thunderstorms developed and moved east across the Big Country, during the post-Midnight hours of the 23rd. The stronger storms contained hail and locally heavy rainfall. Quarter size hail was reported with one of the storms in Abilene. The heaviest rainfall (between 1.5 and 2.5 inches) occurred in Nolan County, south of Interstate 20.
The below radar animation (Figure 5) shows the development and coverage of showers and thunderstorms, between 2:30 AM and 6:30 AM CDT, which affected the Big Country on March 23.
Figure 5: Animated National Weather Service San Angelo Radar Imagery, for March 23.
Rainfall amounts between one half and one inch occurred across much of the northern half of Taylor County (0.56 inches at Abilene), and northern Callahan County.
A dramatic change of weather conditions occurred through the day and night of the 23rd, as a potent upper level storm system moved from the Rockies into the central and southern Plains. Following the thunderstorms which occurred during the post-Midnight hours, cloudy skies, patchy light fog, and cool temperatures persisted into the morning hours. During the afternoon and evening, a dryline surged east into the far western Big Country, and across the Concho Valley and southern sections of west-central Texas. Gusty west winds and an intrusion of very dry air followed passage of the dryline, and temperatures rapidly warmed into the 80s. Between 8:30 PM and Midnight, a strong cold front swept south across all of west-central Texas. Strong, gusty north-northwest winds followed passage of this front, and brought blowing dust into the area. Peak wind gusts reached 48 mph at Abilene, 47 mph at San Angelo, and 45 mph at Junction.
By the early morning of the 24th, temperatures dropped to near 30 degrees across the Big Country, and into the mid to upper 30s farther south. A much colder airmass settled over west-central Texas on the 24th and 25th, as a strong high pressure system extended south from Canada across the Plains states and Texas. Highs on were in the 50s on the 24th, and in the 50s across most of the area on the 25th. These high temperatures were well-below normal for late March. A widespread freeze occurred on the early mornings of the 25th and 26th. Lows were in the 20s to lower 30s on the 25th, and mostly in the 20s on the 26th.
With a return of south winds, a substantial warming trend in temperatures occurred on the 27th to 29th, along with an increase in moisture.
Severe weather occurred in various parts of west-central Texas during the last few days of the month.
With the approach of an upper level disturbance into an unstable airmass, a few severe storms occurred on the evening of the 29th. Quarter size hail was reported 1 mile northeast of Sweetwater, and around Glen Cove (Coleman County). The Coleman County storm intensified and produced hail up to golfball size, 6 miles west and 1 mile east of the town of Coleman.
With the approach of a dryline into an unstable airmass on the 30th, a few storms developed southeast of Abilene and northeast of San Angelo during the early evening. One of the storms became severe and produced large hail, as it tracked southeast across Brown County. The largest hail reports from this storm include golfball size (1 mile northeast of Lake Brownwood) and hen egg size (7 miles north of Early).
Scattered showers and thunderstorms occurred across southern parts of west-central Texas on the 31st, along and just behind a weak cold front moving south through the region. A severe storm produced quarter size hail in Kimble County, 2 miles west and 4 miles north-northeast of Roosevelt.