January 2015 Climate and Hydrology Summary

January 2015

Tulsa: January 2015 was the 50th warmest (38.4°F, tied 1906; since 1905) and the 36th driest (0.75"; since 1888) January on record. A trace of snow fell this month, which ties several years (since 1900).

Tulsa: Daily records set or tied this month include record warm maximum temperatures.

Fort Smith: January 2015 was the 62nd warmest (39.8°F; since 1883) and the 65th wettest (2.22"; since 1883) January on record. A trace of snow fell, which ties several years (since 1884).

Fayetteville: January 2015 was the 28th coldest (35.2°F; since 1950) and the 15th driest (1.11"; since 1950) January on record. A trace of snow fell, which tied several years (since 1950).

McAlester: Daily records set or tied this month include record warm maximum temperatures.

Using the radar-derived estimated observed precipitation from the RFCs, rainfall totals for January 2015 ranged from 0.50” in northeast OK to around 4” in southeast OK. The majority of the HSA received 1”-3” of rain this month. Most of the HSA received below normal rainfall this month, with the greatest deficits occurring north of I-40. Portions of southeast OK, including parts of McIntosh, Pittsburg, Haskell, Le Flore, Pushmataha, and all of Choctaw Counties, received above normal rainfall this month with 110%-150% of the normal January rainfall. However, north of I-40, most locations only received 25% to 75% of the normal rainfall in January.

2015 began cold, with temperatures 10-20°F below normal on several days during the first half of the month. This was then followed by a warm second half of January, with several days of temperatures 10-20°F above normal. This resulted in near normal temperatures across the region for January as a whole. Far southeast Oklahoma started the year off with above normal rainfall; however, well below normal precipitation fell across northeast OK and northwest AR north of I-40.

According to the Drought Monitor from February 3, 2015, Severe Drought (D2) conditions were occurring across portions of Osage, Pawnee, northern Creek, and far western Tulsa Counties in eastern OK. Moderate Drought (D1) conditions were present across portions of Osage, Pawnee, eastern Kay, Tulsa, Creek, Washington, Rogers, and western Wagoner Counties in eastern OK. Abnormally Dry (D0), but not experiencing drought, conditions existed across the remainder of eastern OK, except for Le Flore, eastern Sequoyah, and southeastern Adair Counties. Abnormally Dry (D0) conditions were also present in western Benton County in northwest AR.

According to the Oklahoma Climatological Survey, January 2015 was the 26th driest for northeast Oklahoma, the 39th driest for east central Oklahoma, and the 39th wettest for southeast Oklahoma. Records go back to 1921. For the Water Year-to-date, October 1, 2014-January 31, 2015, northeast Oklahoma ranked as the 39th wettest, east central Oklahoma was the 40th wettest, and southeast Oklahoma was the 40th driest period.

Outlook

The Climate Prediction Center CPC outlook for February 2015 (issued January 31, 2015) indicates an equal chance for above, near, and below normal temperatures and precipitation across all of eastern OK and northwest AR. This outlook is based on weak or conflicting signals among the computer models, in addition to uncertainty regarding the possible impacts from El Niño.

The Climate Prediction Center CPC outlook for the 3-month period February-March-April 2015, CPC is forecasting a slightly enhanced chance for below normal temperatures across all of eastern OK and northwest AR. This outlook also indicates equal chances for above, near, and below median precipitation across eastern OK and northwest AR (outlook issued January 15, 2015). This outlook is based on both statistical and dynamical forecast tools and considering weak El Niño conditions.

According to CPC, current atmospheric observations continue to show mixed signals regarding the ENSO state. Taken as a whole, ENSO neutral conditions remain, with some aspects of an El Niño event. CPC is forecasting a 50%-60% chance for El Niño development during the next two months, with a return to ENSO neutral conditions favored thereafter.