Climate Summary for May 2014

* 2nd wettest May on record at San Angelo *

 Precipitation for May was well-above normal across much of west-central Texas between Interstate 20 and Interstate 10 (Figure 1). 

Figure 1: Percent of Normal Precipitation for May, 2014.

The monthly precipitation was near to above normal across much of the Big Country.  The May precipitation was below normal across the far northern Big Country, in far southern Crockett County, and in scattered pockets of Sutton County.  Most of the monthly rainfall occurred with a significant heavy rain event late in the month (Memorial Day Holiday weekend). 

At Abilene Regional Airport, the average temperature for May was 74.1 degrees. This was 1.1 degrees above the normal average temperature of 73.0 degrees. Total precipitation for Abilene in May was 2.22 inches. This was 0.96 inches below the normal of 3.18 inches.

At San Angelo Regional Airport, the average temperature for May was 75.0 degrees. This was 0.5 degrees above the normal average temperature of 74.5 degrees. Total precipitation for San Angelo was 7.75 inches. This was 4.93 inches above the normal of 2.82 inches.  This marks the 2nd wettest May on record for San Angelo.

The number of days in May with high temperatures of 100 degrees or more include:
2 at San Angelo, 1 at Abilene, and zero at Junction.

Cool low temperatures occurred on May 1st.  An upper level disturbance entered Texas from the southern Rockies, but only brought cloud cover and sprinkles of rain, due to a dry atmosphere.  

With a cool airmass in place, mostly clear skies and light winds allowed temperatures to dip into the mid to upper 30s for early morning lows on the 1st, across eastern sections of west-central Texas.  The low of 38 degrees at Abilene was a couple of degrees above the record low for the 1st.  Later on the 1st, an upper level disturbance entered Texas from the southern Rockies, but only brought increased cloud cover and sprinkles of rain, due to a dry atmosphere.

Mostly clear skies and a significant warming trend in temperatures occurred early in the month. Record highs were set at Abilene (104 degrees) and tied at San Angelo (103 degrees) on the 5th.  

With the approach of an upper level disturbance and dryline into a very unstable airmass, a significant severe weather event occurred on the evening and early nighttime hours of the 7th.  Most of the severe storms affected the Big Country, Concho Valley and Northern Edwards Plateau. The below radar animation (Figure 2) shows the development and coverage of storms between 645 PM and 10 PM, on May 7th. 

Figure 2: Animated National Weather Service San Angelo Radar Imagery, for May 7.         

A writeup for this severe weather event can be accessed here.

In all, a total of 33 severe weather reports were received for this event.

Locally heavy, but beneficial rainfall occurred with these storms.  Figure 3 (below) shows rainfall amounts across west-central Texas, for the 24-hours ending at 7 AM on May 8th.

Figure 3: West-Central Texas Rainfall for the 24-hour period ending at 7 AM, May 8.

Scattered showers and thunderstorms occurred across the area southeast of a line from Abilene to San Angelo to Ozona on the 9th, with the approach of a weak upper level disturbance and weak cold front.  Hail to ping pong ball size was reported from a severe storm at Fort Mckavett (Menard County). 

Severe storms with large hail and damaging winds occurred across southeastern sections of west-central Texas on the afternoon of the 12th, with the arrival of a strong cold front and approach of a strong upper level disturbance.

A total of 11 severe weather reports were received for this event.  Locally heavy rainfall also accompanied the thunderstorms, especially across Mason, San Saba, and extreme southeastern Kimble Counties.  Figure 4 (below) shows rainfall amounts across west-central Texas, for the 24 hours ending at 7 AM on May 13th. 

Figure 4: West-Central Texas Rainfall for the 24-hour period ending at 7 AM, May 13. 

Following the cold frontal passage, much cooler air invaded the region on the 13th.  Daytime temperatures on the  13th were only in the upper 50s to lower 60s, with cloudy skies and gusty north winds.  Numerous showers and thunderstorms also occurred.  Rainfall amounts between two two tenths and one half inch occurred across much of the area south and east of a line from Mertzon to Coleman to Throckmorton.  Clearing skies and light winds on the following night allowed temperatures to drop to between 35 and 45 degrees for early morning lows on the 14th across west-central Texas.  Record low temperatures were recorded at San Angelo (37 degrees) and Abilene (41 degrees) on the 14th.      

Temperatures were much warmer with highs back in the 90s on the 16th.  Above normal temperatures continued through the 22nd, with gusty south winds.  

Significant heavy rainfall and severe weather occurred over the Memorial Day holiday weekend (May 23-26). This was brought about as a late season upper level low pressure system moved slowly east across northern New Mexico and into the Texas Panhandle.

In the days preceding this event, moisture increased considerably across the area with gusty south to southeast winds. With a warm and unstable airmass along with the presence of surface outflow boundaries, several rounds of showers and thunderstorms occurred from the 23rd through the 26th, with fairly widespread coverage across west-central Texas.  Thunderstorms and heavy rainfall were focused especially near the outflow boundaries.

On the 24th, a number of severe storms affected the western Big Country, Concho Valley, and Crockett County.  Brief tornado touchdowns were reported in Crockett County, 41 miles west-northwest of Ozona and 38 miles west-southwest of Barnhart.  In Irion County, a tornado crossed open country near oilfields 12 miles north-northeast of Barnhart.  Large hail (to golfball size) and damaging winds were reported with other severe storms.   

On the 25th, a few severe storms (with large hail and strong winds) occurred during the post-Midnight hours, across the counties along the interstate 10 corridor (Crockett and Kimble Counties).    

Extensive severe weather occurred across central and southern sections of west-central Texas, from the evening of the 26th into the post-Midnight hours of the 27th.  A couple of tornadic storms moved southeast into Sterling County and remained in rural areas.  A brief tornado touchdown occurred in far northwestern Tom Green County, 3 miles southwest of Water Valley.  The largest reported hail was tennis ball size, 5 miles west-northwest of Sterling City.  Several reports of golfball size hail were received in Sterling and Tom Green County, including at Grape Creek and the north side of San Angelo.

While the heavy rainfall brought short-term benefits to the drought stricken region, it also caused localized flash flooding.  Extensive street flooding occurred in San Angelo and Wall.  

Figure 5 (below) shows rainfall amounts across west-central Texas, for the 7-day period ending at 7 A.M. on May 27th.  This shows the rainfall totals which occurred during the Memorial Day holiday weekend.

Figure 5: West-Central Texas Rainfall for the 7-day period ending at 7 AM, May 27.

The heaviest rainfall (6-10 inches) occurred across parts of the Concho Valley and Heartland, and in isolated pockets across the southern third of west-central Texas.  Rainfall totals over 10 inches occurred in parts of Tom Green County, east and southeast of San Angelo.  New daily record rainfall was set at San Angelo on May 24-26. 

The water runoff from this rainfall increased water levels on area reservoirs across central sections of west-central Texas.  This included the O.H. Ivie and Twin Buttes Reservoirs, Lake Nasworthy, and to a lesser extent the O.C. Fisher Reservoir. 

As the upper level low pressure system moved across northwestern Texas, scattered thunderstorms developed during the afternoon of the 27th.  A few storms were severe, with large hail.  In San Saba County, baseball size hail was reported 9 miles east of Spring Creek.  Golfball size hail and a funnel cloud were reported 9 miles east-northeast of San Saba. A funnel cloud was also reported 3 miles south-southeast of Chappell.