Autumn off to cool and wet start

September 2010 will be remembered as the month the heat finally broke, as if on cue. 

After weeks of uninterrupted heat and drought during August, we reached 96 degrees on September 1, then big storms broke over North Texas with 1.77” of rain recorded at DFW and 1.93” at Denton that evening and another .18” the following day with a high of only 83.  The next few days, our weather was quite humid but highs stayed in the 80’s and lower 90’s with overnight lows finally dropping into the 60’s.  The change was definitely welcome.   

One week later, remnants of a tropical system spread northward from the coast and from Mexico with record-setting rains but not until Labor Day had passed. 

DFW recorded an inch of rain on the night of September 7th and a record 5.24” of rain on September 8th.  Denton’s official rainfall was 1.2” on September 7th and 5.2” on the 8th.  We then ended the day’s flooding with a tornado outbreak, which was a rare sequence of events.  Multiple tornadoes were captured that afternoon on live video from Oak Cliff, Dallas and Seagoville, northward through Lindsay, west of Gainesville in Cooke County. 

Denton County was spared the most damaging storms after Labor Day and again at mid-month when strong storms backed into Dallas County from the east.   The humid conditions continued until late in the month.  

The next significant weather outbreak was on Saturday, September 25th when heavy rains moved across North Texas.  Officially, Denton received .41.”  The pattern of heat and humidity was finally broken by a mid-latitude cold front that brought drier, milder air to North Texas.   

For the entire month, Denton recorded an average high of 88, a low of 77 and total rainfall of over 9.3.” 

With the exception of the tropical weather remnants that caused flooding after Labor Day, our weather generally reflects the deepening La Nina of cooler ocean temperatures in the Pacific.  The most common La Nina patterns of fall weather in North Texas favor drier and warmer-than-normal weather which we expect in October.  All things considered, September’s record rains have a silver lining. 

Brad Barton is Chief Meteorologist of WBAP 820 AM/96.7 FM. Follow him online at www.WBAP.com and www.bradsweather.com. Paul Ruekberg of Newswatch Dallas contributed to this report.