Where were the April showers?

April began with one of the busiest single tornado outbreaks in North Texas history, but our rainfall was disappointing.

Here are the numbers:  

Average high was 77, one degree above normal.  
Average low was 54, one degree below normal.  
Rainfall through April 25 was just .68” which was over two inches below April’s historic average of 3.07”  

Denton Municipal Airport recorded only .19” of rain on April 3; .18” on April 8; .24 on April 15 and trace amounts on April 14, 19, 20 and 25.  

During the month, most storms seemed to miss Denton County, but April 3 was one for the record-books.  Seventeen tornado touchdowns occurred from at least three supercell storms that plagued North Texas for several hours that day.  One of the touchdowns south of Denton was a brief tornado rated EF-0 for the minimal damage it produced.  National Weather Service survey teams reported its damage path indicated the tornado was about 50 yards wide and remained on the ground for only a quarter-mile.  One other tornado that skipped around Coppell may have touched down briefly in Lewisville.  Scattered non-tornadic wind damage and hail damage was common.  

The worst single-day tornado outbreak since 2006 was notable for the number and concentration of tornadoes threatening high-density population-areas.  Sustaining such damage with no fatalities and few injuries is remarkable.  That’s something to be proud of.  Denton and all of North Texas were fortunate to miss the super outbreak of over 136 touchdowns in Oklahoma and Kansas on April 15.    

Water temperatures continue to warm in the central Pacific, indicating the La Nina that has lasted nearly two years is virtually over.  Long-range forecasts hint that an El Nino of unusually warm ocean temperatures may be brewing for late summer and fall.  If so, we can expect relatively normal rainfall with warmer-than-normal temperatures during May.  

At a recent meeting of meteorologists and emergency managers from cities across North Texas, a new policy was announced.  Because there is no standard criteria for sounding emergency warning sirens in severe weather, citizens are often confused and hesitate to take shelter.  

Some cities sound the sirens only for a confirmed tornado while others sound their sirens for any tornado warning and even severe thunderstorm warnings with unusually bad lightning, 70 mph winds or hail greater than 1-inch.  

For that reason, it was agreed that we all settle on a single message conveyed by the sirens.  If you hear emergency warning sirens in any city during stormy weather, the message is, “go inside or find the best nearby shelter available and find out (by radio, television, NOAA All Hazards radio, Internet or mobile device) why the sirens were activated.”

May is usually the peak of the spring severe weather season in North Texas.  Expect more storm outbreaks.

Brad Barton is Chief Meteorologist of WBAP 820 AM/96.7 FM and Founder of WeatherInTouch.net.