After rainy start, August dries out

Oklahoma’s rainy start to summer fizzled in August as the state had a measly rainfall average of 2.3 inches, according to Gary McManus, associate climatology for the Oklahoma Climatology Society.

The combined rainfall average for May through July was the wettest in state history but the August total was a full half-inch below normal.

Tulsa and Northeast Oklahoma actually saw a surplus of 1.7 inches of rain while the Oklahoma City area was down 2.1 inches on average.

Miami led the state with 8.51 inches of rain, which is more than 5 inches above normal for that location. Madill, in far south central Oklahoma, barely wet the gauge with 0.04 inches. That is a stark contrast to the 43.71 inches of rain Madill received April-July, including 23.25 inches in May alone.

August’s rain totals might have diminished the climatological summer’s (June-August) ranking, but the season still finished as the 28th wettest on record with a statewide average of 12.13 inches, 1.78 inches above normal.  The year still leads 1957 in the race to finish as the wettest on record for Oklahoma.  The 2015 January-August statewide average was 36.19 inches, 11.33 inches above normal and 0.32 inches ahead of 1957’s mark. That leaves 2015 just 11.69 inches off 1957’s calendar year record total of 47.88 inches.

“The final four months of the year average 12.07 inches of precipitation, so even a slightly below normal finish to the year can still garner 2015 the record,” McManus said.

The outlooks called for a cooler than normal August, and those prognostications were prophetic with a statewide average of 78.8 degrees. That’s 2 degrees below normal to rank the month as the 24th coolest August on record.

High temperatures in August ranged from a maximum of 107 degrees at Hollis on the sixth to a chilly 68 degrees at Boise City on the 23rd.

El Reno got down to an October-like 47 degrees on the 20th, and many other Mesonet sites reached lows in the 40s or lower 50s on the 19th and 20th.

Record lows were set at Oklahoma City, Muskogee, McAlester and Bartlesville on the 20th according to National Weather Service (NWS) reports.

“With the dry conditions mounting across the southeast, flash drought conditions continued to intensify in that region,” McManus said. “Dead and dormant vegetation, desiccated soils and flagging streamflows were some of the key indicators of the spreading hazard.”

By the end of August, more than 18 percent of the state was considered in at least abnormally dry conditions according to the U.S. Drought Monitor, and nearly 9 percent in moderate drought.

The Climate Prediction Center (CPC) sees increased odds for above normal temperatures across far eastern Oklahoma during September, with similar odds for above normal precipitation in the northwestern half of the state, especially the Panhandle.