Severe Weather Punctuates April

Following a few brief glimpses in March, spring finally arrived in earnest during April. The month was wet for most and warm for all, and came complete with all the spring severe weather hazards Oklahomans are accustomed to. The state’s first official tornado of 2019 struck on the 17^th near Shattuck. The twister, rated an EF1 by the National Weather Service (NWS), damaged homes, sheds, trees and fences. Baseball size hail fell near Selman in Harper County that same day, and near Gould in Harmon County on April 3. Non-thunderstorm related severe winds damaged scaffolding at a bridge construction site in Moore on the 13^th, shutting down Interstate 35 in both directions. The area around Hobart in Kiowa County received 5-7 inches of rain overnight on the 23^rd and resulted in severe street flooding. Mother Nature spun a severe tale to end the month as well. Tornadoes, flash flooding, and large hail began before noon on April 30, and the severe weather intensified as the day wore on. As many as a dozen twisters were reported. The official tally will be determined with further investigation by NWS personnel. Flooding was widespread across the southeastern two-thirds of the state, with some areas receiving more than 6 inches of rain in just a few hours. Significant flash flooding was reported in Nowata, Ottawa, and Tulsa counties.

The deluge to end the month boosted the statewide average rainfall total from the Oklahoma Mesonet to 4.75 inches, 1.49 inches above normal to rank as the 22^nd wettest April since records began in 1895. All regions of the state finished above normal for the month save for the Panhandle, which fell 0.67 inches below normal for their 44^th driest April on record. Southwestern Oklahoma was the wettest area relative to normal with an average of 6 inches, 3.37 inches above normal – their seventh wettest April on record. Hobart led the state with 9.91 inches of rain, a whopping 7.45 inches above its normal April total. Sixty-three of the Mesonet’s 120 stations recorded at least 5 inches of rain during the month, while all six stations in the Panhandle had less than an inch. 2019 was off to a wet start with a January-April statewide average of 10.93 inches, 1.24 inches above normal to rank as the 27^th wettest such period on record.

The statewide average temperature was 60.4 degrees, 1.1 degrees above normal to rank as the 45^th warmest April on record. The state saw its first 90-degree temperatures of 2019 on April 9 at the Beaver, Stillwater and Waurika Mesonet sites. Those were the first 90s in the state since Oct. 6, 2018. April’s last freeze – and possibly the state’s final spring freeze – occurred on the 19^th in the Panhandle. The month’s highest reading of 94 degrees was recorded at both Buffalo and Hollis on April 10. The lowest mark of 21 degrees was reported at Eva on April 14. The first four months of 2019 fell 0.6 degrees below normal at 46.8 degrees to rank as the 56^th warmest January-April on record. Southeastern Oklahoma was the only region of the state above normal for that period with an average of 50.2 degrees, 0.6 degrees above normal to rank as their 39^thwarmest.

Drought development during April was prevented by the abundant moisture. In areas where moisture was a bit more scarce, previous rains kept drought at bay. Abnormally dry conditions were present in southwestern Oklahoma on the U.S. Drought Monitor to start the month but were quickly eradicated by heavy rains in that region. The Climate Prediction Center’s (CPC) temperature outlook for May indicated increased odds of below normal temperatures across the western half of the state, with the odds a bit greater in the Panhandle. The May precipitation outlook showed increased odds of above normal rainfall across the entire state. Those odds were much greater across far southeastern Oklahoma, however. CPC’s drought outlook for May did not foresee new drought development within the Southern Plains or Oklahoma.