May was a cool, damp month for Denton County with several threats of damaging storms, most of which missed us. Remnants of El Nino produced frequent Pacific storm systems that tapped Gulf moisture as well as Canadian air, extending what turned out to be a damp, cooler-than-normal spring.
Our warmest high temperature for May was 92 on the 10th, but we tied, even exceeded record cool high temperatures of 62 degrees on the 18th and 63 on the 19th. Overnight low temperatures were equally mild, dipping as low as 43 degrees on the morning of May 3rd. Our average high for entire month was 78, while our average low was 58, giving us a day/night monthly average of 68 which was nearly 3 degrees cooler than normal.
Rainfall was frequent, yet never unusually heavy until the end of the month. We had .22″ on the 2nd, .85″ on the 8th and 9th, .60″ spread over the 17th, 18th and 19th and .65″ on the 22nd, 23rd, and 24th. By May 25th, Denton Enterprise Airport had collected only 2.84 inches of rain which was an inch below normal, but heavier rains of 2 inches or more over Memorial weekend brought our monthly total above our historic average of around 4 inches for May.
Severe weather struck all around North Texas several times during the month, but most wind and hail damage occurred outside of Denton County.
A brief word about outdoor warning sirens: As a meteorologist who is wedged tightly into the local warning apparatus, it’s frustrating that individual municipalities have so many conflicting criteria for sounding their sirens. Some set off the sirens for a tornado warning, others for warnings of hail over an inch, still others for warnings that mention straight-line winds of 70 miles an hour. My fear is that outdoor warning sirens are being used so often for non-tornadic weather that, when an actual tornado is bearing down on a community, the sirens will be misunderstood or worse, ignored. Bottom line: Whenever sirens are sounded during stormy conditions, everyone outside needs to get inside to shelter immediately and not come out until you know what triggered them.
Looking ahead, the changeover from unusually warm Pacific Ocean temperatures of El Nino are expected to give way to cooler water temperatures of a La Nina. Climatologically, when a La Nina follows a strong El Nino, we get a hotter-than-usual summer. Six of our ten hottest summers in the past 30 years have occurred when a La Nina followed closely behind an El Nino.
Despite prospects of a hot summer, ocean temperatures in the Pacific have just barely reached the neutral point in their cooling phase, which means there’s still leftover momentum from the El Nino. Expect more unsettled and occasionally stormy weather through at least the first half of June before rainfall drops off and temperatures start to climb into the 90’s consistently.
Brad Barton is Chief Meteorologist of WBAP 820/570 KLIF/99.5 The Wolf and serves as the live voice of EAS warnings in North Texas.