August Rains Shrink Drought

Autumnal temperatures, heavy rain, and drought reduction captured the Oklahoma weather headlines during August, although the blazing voice of summer was still heard on occasion. Drought shrank considerably in both coverage and intensity during the month thanks to some well-placed heavy rains. Wind, hail and flash flooding accompanied a somewhat unusual uptick in severe weather. Flash flooding necessitated water rescues in several cities, and a Main Street bridge was washed away in Norman. The severe weather culminated with two confirmed tornadoes in Mayes and Rogers counties on Aug. 19, damaging mobile homes, outbuildings and trees. The first tornado passed over the Oklahoma Mesonet station east of Inola, producing a wind gust of 98 mph near the ground. The rains were the real star of the month, however.

According to preliminary data from the Mesonet, the statewide average rainfall was 3.99 inches, 1.04 inches above normal to rank as the 22^nd wettest August since records began in 1895. Thirty-two of the Mesonet’s 120 sites received at least 5 inches of rain, and another 22 recorded 4 inches or more. Miami led the state with 11.28 inches, although Wister was close behind at 10.56 inches. Apache had the lowest total of 1.14 inches. Twelve other sites, each across western Oklahoma, failed to reach 2 inches. The June-August statewide average of 10.8 inches was 0.45 inches above normal to rank as the 41^st wettest climatological summer on record. The Panhandle enjoyed its 12^th wettest summer with an average surplus of 3.21 inches. Sites in Beaver County were more than 5 inches above normal for the season. In contrast, many of the Mesonet locations in the southwest corner of the state were nearly 5 inches below normal. Wister was an impressive 11.6 inches above normal for the summer at 22.3 inches. The January-August statewide average of 23.58 inches was 1.28 inches below normal. A swath from southwest through northeast Oklahoma was 10-12 inches below normal for the first eight months of the year.

The month was decidedly mild with a statewide average temperature of 79.5 degrees, 1.3 degrees below normal to rank as the 37^th coolest August on record. The Mesonet’s 120 sites failed to record a single triple-digit temperature on 16 days during the month. Hollis and Hooker led August with highs of 104 degrees on the 17^th and 30^th, respectively. Eva fell to 48 degrees on the 21^st for the month’s lowest temperature. The heat index soared to 113 degrees on the 16^th at Webbers Falls. Thirty-four heat index readings of at least 110 degrees were recorded Aug. 16-17. Bolstered by the warmer-than-normal months of June and July, the climatological summer ended as the 34^th warmest on record, 1.3 degrees above normal. Similarly, the first eight months of the year were 0.7 degrees above normal to rank as the 30^th warmest January-August on record.

Drought coverage across the state was reduced from 55 percent at the end of July to 31 percent at the of August, with a wide strip of drought-free conditions from the western Panhandle through eastern Oklahoma. Drought intensity was reduced as well. Areal coverage of drought considered at least in the severe category fell from 32 percent to 19 percent. The Drought Monitor’s intensity scale slides from moderate-severe-extreme-exceptional, with exceptional being the worst classification. The southwest remained the hardest hit area with 94 percent considered to be in severe or extreme drought.

The September temperature outlook from the Climate Prediction Center (CPC) indicated increased odds of above normal temperatures across the entire state, with those odds a bit more enhanced in the eastern third. The precipitation outlook showed enhanced odds of above normal precipitation across the far northwest, but a bit higher chances in the Panhandle. CPC’s September drought outlook called for drought improvement or removal in the northeast and far southwest areas of the state, but persistence in south central Oklahoma.