April Tornado Outbreak Scars Oklahoma

Severe weather roared back into Oklahoma during April with giant hail, severe winds up to 80 mph, flash flooding, and over 40 tornadoes—a number that is destined to grow with further investigation by National Weather Service damage survey teams. That total included a historic outbreak on April 27, a day where at least 22 tornadoes were confirmed to have struck the state—the second-most prolific outbreak for a single day during April on record, behind the 33 twisters back on April 14, 2011. Another four tornadoes touched down just after midnight in eastern Oklahoma to bring the event total to at least 26. Other tornadoes struck on April 1 and 26, and the month ended with a slew of twisters in southwest Oklahoma on its final day. The still-nebulous preliminary total of more than 40 tornadoes marks the month with at least the third-highest April total in Oklahoma since accurate records began in 1950, behind 2011’s 50 and 2012’s record mark of 54. The count also far outpaces April’s average of 11.8, and more than doubles the January-April average of 17. The 1950-2023 annual average number of tornadoes in Oklahoma is 57.5. Add another two events from March 14 and Oklahoma seems well on its way to exceeding its annual average tornado count for the twelfth time in the last 15 years. May sees an average of 24 tornadoes and June’s average stands at 7.3.

The tornadoes on April 27 killed at least four people and injured nearly 300 more, according to the Oklahoma Department of Emergency Management. The day also saw the state’s first violent-rated tornado—EF4 or EF5 on the Enhanced Fujita scale—since May 9, 2016. The lead-up to the outbreak stretched back nearly a week, with Storm Prediction Center outlooks alerting Oklahomans to the possibility of strong, long-tracked tornadoes. Severe weather started early on the 27th with a line of supercells stretched from southwest through north-central Oklahoma, and the first tornado warning was issued for portions of Roger Mills and Dewey counties at 10:10 a.m. Those cells eventually moved into Kansas but not before dumping more than 5-7 inches of rain across Kay County. A lull in activity gave way to two lines of supercells later that evening moving north out of Texas into southern, central, and eastern Oklahoma, dropping tornadoes along the way. The violent EF4 twister struck Marietta with winds estimated at 165-170 mph, causing considerable damage along Interstate 35 and in the city itself. One person was killed along I-35 as the tornado crossed the highway along its 27-mile path. Sulphur suffered the worst hit when an EF3 plowed through the town and flattened many of the buildings in its downtown area with winds estimated at 160-165 mph. One person died in the wreckage of one of those collapsed buildings in downtown Sulphur. Another EF3 killed two people near Holdenville, including a 4-month-old infant. Two more significant tornadoes, rated EF2, struck near Goldsby and Ardmore. The final alert went out at 1:51 a.m. early on the next day, two of the 81 tornado warnings issued by the Norman and Tulsa National Weather Service offices during the event on the 27th that stretched out to early on the following day. Norman issued 62 of those warnings, the most the office has ever issued in a single day.

The statewide average rainfall total for the month was 3.94 inches, 0.35 inches above normal, and ranked as the 41st-wettest April since records began in 1895. The heaviest rains coincided with the worst severe weather, which is often the case during Oklahoma’s spring rainy season. Surpluses of 4-7 inches were common across parts of south central Oklahoma, which saw its April average surge to 7.21 inches, 3.45 inches above normal, ranking as the 10th wettest April for that section of the state. Meanwhile, the Panhandle saw a deficit of over an inch, suffering its 12th-driest April on record. Fittstown led the state with 10.82 inches, 7 inches above normal, while Hooker managed a meager 0.2 inches. Deficits of 1-2 inches dominated much of western and central Oklahoma. The first four months of 2024 had a statewide average rainfall total of 9.62 inches, just 0.01 inches below normal, ranking as the 46th-wettest January-April on record.

Temperatures during April ranged from 96 degrees recorded at several locations on the 14th and 30th to 27 degrees at Kenton on the 10th. The final freeze of April—and presumably spring—occurred on April 22 across the northern half of the state. The statewide average temperature for the month was 62.2 degrees, 2.7 degrees above normal, ranking as the 22nd-warmest April since records began in 1895. The first four months of the year saw a statewide average of 50 degrees, 2.1 degrees above normal, ranking as the 15th-warmest January-April on record.

Flash drought continued to advance throughout the northern half of the state, although rains late in the month undoubtedly eased impacts in many areas. Coverage of drought increased from 9% at the end of March to 36% at the end of April, according to the U.S. Drought Monitor, with severe drought increasing from 0% to 6% over that same period. Major relief is in store for the state, according to the Climate Prediction Center outlooks for May. The precipitation outlook calls for increased odds of above-normal rainfall across all but the far western Panhandle. That, in addition to the rains of late April, fuels CPC’s May drought outlook to call for drought improvement or removal across all but that far western Panhandle region by the end of the month, with drought development likely in Cimarron County. Temperatures are also expected to be above normal during May, especially across the southwestern half of the state.