September 2016 Climate and Hydrology Summary

September 2016

Tulsa: September 2016 was the 19th warmest (77.0°F; since 1905) and the 48th driest (2.31"; since 1888) September on record.

Interestingly, the monthly rainfall totals for both August and September 2016 were exactly the same.

Fort Smith: September 2016 was the 18th warmest (77.4°F, tied 1938, 1930; since 1882) and the 36th driest (1.79", tied 2012; since 1882) September on record.

Fayetteville: September 2016 was the 20th warmest (70.7°F, tied 1988, 1973; since 1949) and the 20th driest (2.64"; since 1949) September on record.

Using the radar-derived estimated observed precipitation from the RFCs, rainfall totals for September 2016 ranged from around 0.25” to around 6”. The greatest deficits were over Cherokee and Adair Counties, while the highest totals were in Craig, Ottawa, Delaware, Benton, Carroll, Madison, and Le Flore Counties. This corresponds to 10% to near 90% of the normal September rain for most of eastern OK and northwest AR, with just a few locations 90% to 150% of normal.

Most of eastern OK and northwest AR had well above normal temperatures and well below normal rainfall in September 2016. But, heavy rain in KS resulted in downstream flooding in northeast OK, including the Neosho River near Commerce.

According to the Drought Monitor from September 27, 2016, D2 (Severe Drought) continued over Wagoner County and spread into Cherokee County. D1 (Moderate Drought) conditions existed over portions of Rogers, southern Washington (OK), Tulsa, eastern Creek, Okfuskee, Okmulgee, western McIntosh, Wagoner, Muskogee, Mayes, Cherokee, Adair, Delaware, far southern Nowata, and western Choctaw Counties in northeast OK. D0 (abnormally dry conditions but not in drought) were present across portions of Osage, Pawnee, Creek, Washington, Nowata, Muskogee, Okmulgee, McIntosh, Pittsburg, Mayes, Delaware, Adair, Sequoyah, Haskell, western Latimer, western Pushmataha, and Choctaw Counties in OK, and Benton and Washington Counties in northwest AR.

According to the Oklahoma Climatological Survey, September 2016 was the 32nd driest for northeast Oklahoma, the 28th driest for east central Oklahoma, and the 35th driest for southeast Oklahoma. Records go back to 1921. For the 60-day period August 2-September 30, 2016, northeast Oklahoma ranked as the 20th driest, east central Oklahoma was the 20th driest, and southeast Oklahoma was the 28th wettest period. For Water Year 2016 (October 1, 2015-September 30, 2016), northeast Oklahoma ranked as the 26th wettest, east central Oklahoma was the 12th wettest, and southeast Oklahoma was the 4th wettest Water Year.

Water Year 2016 (Oct. 1, 2015-Sep. 30, 2016)

Using the radar-derived estimated observed precipitation from the RFCs, rainfall totals for Water Year 2016 ranged from 30” near Ponca City to around 80” in southeast OK. A large portion of the area received 40”-60” of rain this water year. This corresponds to 75% to around 150% of the normal Water Year rain for eastern OK and northwest AR.

In Tulsa, OK, Water Year 2015-16 ranked as the 2nd warmest Water Year (63.7°F; since records began in 1905-06) and the 50th wettest Water Year (40.32”; since records began in 1893-94).

Fort Smith, AR had the 3rd warmest Water Year (64.4°F; since records began in 1882-83) and the 23rd wettest Water Year (50.20”; since records began in 1882-83).

Fayetteville, AR had the 10th warmest (58.8°F, tied 1971-72) and the 21st wettest (49.09”) Water Year since records began in 1949-50.