Volume 20 Number 4                                                                                                             April 2007

         

          April proved to be an interesting month for the state.  Temperatures started off slightly above average in most locations, but dropped dramatically when a very strong cold front moved across the state.  The April 11, 2007 Texas Climatic Bulletin (http://www.met.tamu.edu/met/osc/tx/2007/Apr1Bull07.htm) shows the numerous records regarding temperature and snowfall that resulted from this powerful system.  In all, 14 of the 20 first-order stations reported record setting low temperatures on April 7th, and a few stations (Del Rio and Corpus Christi) reported records on the 8th.  5 of the 20 stations reported record snowfall totals including College Station, which reported latest snowfall ever.  Overall, mean temperatures were below average across the entire state, with the largest departure from average reported at Lubbock with 4.2°F below normal.  The highest temperature for the month was 92°F, reported at both Brownsville and Del Rio.  The coldest temperature for the month was 26°F, reported at both Amarillo and Lubbock.

          Precipitation across the state was split.  The Trans Pecos, Low Rolling Plains, Edwards Plateau, some of South Central, and Upper Coast regions all reported above average precipitation totals, while the rest of the state reported below average totals.  Brownsville only reported 29% of its normal monthly rainfall, while, in contrast, Midland reported 223% of its normal monthly rainfall.

          As for severe weather, this April was a very busy month.  In all, there were 49 tornado reports, 189 hail reports, and 115 severe wind reports.  April 21st was the busiest tornado day with 16 reported.  On the 24th, the Storm Prediction Center had a high risk forecast for northeast Texas.  On that day, there were a total of 92 storm reports including 3 tornadoes, one of which was the deadly tornado that moved through Eagle Pass.

APRIL 2007


* Based on 1971-2000 normals

* Complete temperature data were unavailable.  Temperatures are rounded to the nearest whole degree.

* HDD - Heating degree-day: Refer to the Monthly Average chart for a definition                                                           T = Trace (<0.005")

* CDD - Cooling degree-day: Refer to the Monthly Average chart for a definition                                           M:  Information not available.

 

 

CLIMATIC AVERAGES FOR MAY


Records are at the current site, other records may have occurred at previous sites.

*CDD - Cooling degree-day:  The difference between the mean individual daily temperature and 65°F, with one

CDD resulting for each degree above the standard 65°F during one day.

*HDD - Heating degree-day:  The difference between the mean individual daily temperature and 65°F, with one

HDD resulting for each degree below the standard 65°F during one day.

 

 

 

Past Weather Events in May

 

May 15, 1896:  Tornadoes, Sherman, Grayson, County; Justin, Denton County; Gribble Springs, Cooke County; 76 killed; damage $225,000.

 

May 30, 1909:  Tornado. Zephyr, Brown County; 28 killed, many injured; damage $90,000.

 

May 7, 1919:  Windstorms.  Starr, Hidalgo, Willacy, and Cameron Counties.  Violent thunderstorms with high winds, hail and rain occurred between Rio Grande City and the coast, killing 10 persons.  Damage to property and crops was $500,000.  Seven were killed at Mission.

 

May 24-31, 1929:  Rainstorm.  Beginning over Caldwell County, a storm spread over much of Central and Coastal Texas with maximum rainfall of 12.9 inches, causing floods in Colorado, Guadalupe, Brazos, Trinity, Neches, and Sabine rivers.  Much damage at Houston from overflow of bayous.  Damage estimated at $6 million.

 

May 11, 1953:  Tornado.  Waco, McLennan County; 114 killed, 597 injured; damage $41,150,000.  One of two most disastrous tornadoes; 150 homes destroyed, 900 homes damaged; 185 other buildings destroyed; 500 other buildings damaged.

 

May 11, 1970:  Tornado.  Lubbock, Lubbock County.  Twenty-six killed, 500 injured; damage $135 million.  Fifteen square miles, almost one-quarter of the city of Lubbock, suffered damage.

 

May 5, 1995:  A thunderstorm moved across the Dallas/Fort Worth area with 70 mph wind gusts and rainfall rates of almost 3 inches in 30 minutes (5 inches in 1 hour).  Twenty people lost their lives as a result of this storm, 109 people were injured by large hail and, with more than $2 billion in damage, the National Oceanic and Atmospheric Administration dubbed it the "costliest thunderstorm event in history."

 

May 27, 1997:  A half-mile-wide F5 tornado struck Jarrell (Williamson Co.), leveling the Double Creek subdivision, claiming 27 lives, injuring 12 others, and causing more than $40 million in damage.

 

 

Dr. John Nielsen-Gammon (State Climatologist)

Matt Mosier (Undergraduate Assistant)