July 2012 Climate and Hydrology Summary

Tulsa: July 2012 was the 6th warmest (88.9°F; since 1905) and the 36th driest (1.38"; since 1888) July on record.

Tulsa recorded its all-time hottest minimum temperature of 88°F on July 30 and 31, 2012. The previous record was 87°F, which occurred on August 2, 2011 and July 16, 1980.

Tulsa tied its all-time hottest daily mean temperature of 100°F on July 31, 2012. This record also occurred on August 2, 2011. This is also the hottest mean temperature ever recorded in July at Tulsa.

Tulsa had high temperatures greater than or equal to 100°F on 18 days in July. This ranks as the 7th most number of days on record.

Fort Smith: July 2012 was the 4th warmest (88.0°F; since 1882) and the 36th wettest (3.91"; since 1882) July on record.

Fort Smith had high temperatures greater than or equal to 100°F on 19 days in July. This ranks as the 4th most number of days on record.

Fort Smith had high temperatures greater than or equal to 100°F for 9 consecutive days, ending on July 26, 2012. This stretch ties for 19th greatest number of days, with a record of 35 days ending 8/8/2011.

McAlester: Daily records set or tied this month include a record warm maximum temperature, and a record daily rainfall.

McAlester had high temperatures greater than or equal to 100°F on 12 days in July. This ranks as the 10th most number of days on record.

Fayetteville had high temperatures greater than or equal to 100°F on 8 days in July. This ranks as the 8th most number of days on record.

Bartlesville had high temperatures greater than or equal to 100°F on 19 days in July. This ranks as the 6th most number of days on record.

This year, Tulsa and Fort Smith recorded their all-time warmest January 1-July 31 period for their respective periods of record.

This year, the enitre states of Oklahoma and Arkansas recorded their all-time warmest January 1-July 31 period since records began in 1895.

Using the radar-derived estimated observed precipitation from the RFCs, rainfall totals for July 2012 ranged from less than 0.25” in isolated areas of northeast OK to near 6” across portions of southeast OK and west central AR. Most of northeast OK received less than 25% of the normal July rainfall this month, with several areas below 5%. Most of the remainder of the HSA received around 25%-75% of the normal July rain, with isolated portions of far southeast OK and west central AR benefiting from above normal rainfall.

Significant deterioration in drought conditions occurred during July 2012. According to the Drought Monitor from July 31, 2012, all of eastern OK and northwest AR was in severe to extreme drought. Severe (D2) drought was present across portions of southern Choctaw, northwest Pushmataha, Pittsburg, Latimer, southern Okfuskee, McIntosh, far eastern Haskell, eastern Osage, Washington (OK), Nowata, Craig, Rogers, Mayes, and western Delaware Counties. Extreme drought (D3) conditions existed across the remainder of the area. The drought has caused significant hardship to the agricultural industry across the county, and the USDA Disaster Designation area so far this year is the largest in history.

The hot and dry conditions this month led to an increase in wildfire activity across eastern Oklahoma and northwest Arkansas. Of note were a 5,580 acre fire reported 1 mile north of Depew, OK (Creek Co.) on the 20th (no known structures lost). Another large wildfire of 1,700 acres occurred near Oologah (Rogers. Co.) on the 19th. And, a 350 acre wildfire on the 29th near Morse (Okfuskee Co.) threatened 7 residences and burned 8 outbuildings.

According to the Oklahoma Climatological Survey (OCS) for the 30-day period July 2-July 31, 2012, northeast OK ranked as the 9th driest, east central OK ranked as the 23rd driest, and southeast OK ranked as the 34th wettest since records began in 1921. For the 90-day period May 3-July 31, 2012, northeast OK ranked as the #1 driest, east central OK ranked as the 2nd driest, and southeast OK ranked as the 10th driest since records began in 1921.

Some of the lowest precipitation reports (in inches) for July 2012 included: Vinita, OK (mesonet) 0.05; Copan, OK (mesonet) 0.07; Claremore 2ENE, OK (coop) 0.16; Pawnee, OK (coop) 0.17; Claremore, OK (mesonet) 0.18; Jay, OK (mesonet) 0.19; Hectorville, OK (mesonet) 0.24; Porter, OK (mesonet) 0.25; Oilton, OK (mesonet) 0.35

Outlook

The Climate Prediction Center CPC outlook for August 2012 (issued July 31, 2012) indicates an enhanced chance for above normal temperatures and below normal rainfall. This outlook is based on consistent signatures from climate model forecasts, very low soil moisture conditions, long-term temperature trends, and temperature trends over the past 30 days. The very low soil moisture values and severe reductions in evapotranspiration can result in perpetuating the regional drought.

For the 3-month period August-September-October 2012, CPC is forecasting an enhanced chance for above average temperatures and equal chances for above, near, and below median precipitation across the region (outlook issued July 19, 2012). This outlook is based on dynamic computer model output and long term trends. Initial soil moisture conditions are drier than normal going into Aug-Sep-Oct, increasing the chances for above normal temperatures.

According to CPC, ENSO neutral conditions continued through July, but El Niño conditions should develop by the end of summer. Weak to moderate El Niño conditions will likely be in place by the end of the year.