May 2014 Climate and Hydrology Summary

Tulsa: May 2014 was the 37th warmest (70.5°F, tied 1980, 1933, 1922; since 1905) and the 36th driest (3.51"; since 1888) May on record.

Fort Smith: May 2014 was the 58th warmest (70.2°F, tied 1982; since 1883) and the 39th wettest (6.18"; since 1883) May on record.

Fayetteville: May 2014 was the 34th warmest (65.4°F; since 1950) and the 13th driest (3.43"; since 1950) May on record.

May 2014 was overall a dry month, with fairly seasonal temperatures. Below normal amounts of precipitation fell at 3 of the 4 climate sites (Tulsa (-2.40"), Fayetteville (-2.61"), and McAlester (-1.96")), with above normal precipitation in Fort Smith (+0.71"). Temperatures at all 4 climate sites ran slightly above normal for the month, ranging between 0.3°F to 1.2°F above normal.

Using the radar-derived estimated observed precipitation from the RFCs, rainfall totals for May 2014 ranged from about 1” to 10”, with a large portion of the area receiving 3”-6”. This resulted in much of the region only receiving about 50% of the normal May rainfall. However, portions of southeast Oklahoma and western Arkansas saw above normal rainfall, with up to 125% to 150% of the expected precipitation for May.

May 2014 brought several rounds of severe weather, along with flooding rains, mainly during the first half of the month. Severe weather developed on May 8th, producing damaging wind gusts and hail, along with very heavy rainfall. Southeast Oklahoma into western Arkansas received between 2 - 4 inches of precipitation. During the evening hours on May 12th, severe storms moved across the forecast area, producing strong damaging winds, as well as very heavy rainfall. Flash flooding was reported in Talihina, where between 2 - 2.5 inches of rainfall was recorded and water rose into several buildings in the downtown area. A third round of severe weather occurred on May 15th, when strong damaging winds and hail were reported in parts of western Arkansas, near the Fort Smith area.

According to the Drought Monitor from May 27, 2014, much of northeast Oklahoma remained in a Moderate to Extreme Drought (D1-D3) by the end of the month. The worst conditions were along and northwest of Highway 44, where Severe and Extreme Drought (D2 & D3) conditions persisted. Southeast of Highway 44, higher levels of precipitation had fallen during the month, lessening the drought conditions to Moderate Drought (D2) and Abnormally Dry (D1) conditions. The drought across northwest Arkansas remained in the Abnormally Dry (D1) category.

According to the Oklahoma Climatological Survey, the 30-day period of May 3-June 1, 2014 was the 28th driest for northeast Oklahoma, the 35th driest for east central Oklahoma, and the 36th wettest for southeast Oklahoma. Records go back to 1921.

According to the Oklahoma Climatological Survey, the 120-day period of Feb2-June 1, 2014 was the 3rd driest for northeast Oklahoma, the 8th driest for east central Oklahoma, and the 26th driest for southeast Oklahoma. Records go back to 1921.

Spring (March - April - May) 2014

Tulsa: Spring 2014 was the 30th coldest (58.8°F, tied 1976, 1940, 1914; since 1905) and the 19th driest (8.00"; since 1888) spring on record. For the cold season 2013-14, Tulsa recorded 12.4" of snow, making this the 31st snowiest cold season (tied 2008-09; since 1900-01).

Fort Smith: Spring 2014 was the 53rd coldest (60.7°F, tied 1999, 1914; since 1883) and the 52nd wettest (12.97"; since 1883) spring on record. For the cold season 2013-14, Fort Smith recorded 10.7" of snow, making this the 23rd snowiest cold season (since 1883-84).

Fayetteville: Spring 2014 was the 7th coldest (54.7°F, tied 1984, 1952; since 1950) and the 23rd driest (12.04"; since 1950) spring on record. For the cold season 2013-14, Fayetteville recorded 17.9" of snow, making this the 7th snowiest cold season (since 1950-51).

Outlook

The Climate Prediction Center CPC outlook for June 2014 (issued May 31, 2014) indicates equal chances for above, near, and below normal temperatures for all of eastern Oklahoma and northwest Arkansas. For precipitation, most of eastern Oklahoma lies in the "equal chances" area indicating an equal chance for above, near, and below precipitation, however, far northeast Oklahoma and much of northwest Arkansas are under an area of slightly enhanced chance for above normal precipitation. This outlook is based primarily on dynamical computer models, as well as climate forcing mechanisms such as soil conditions and decadal-timescale climate trends.

The Climate Prediction Center CPC outlook for the 3-month period June-July-August 2014 (issued May 15, 2014) is forecasting an enhanced chance for above normal temperatures across all of eastern Oklahoma and northwest Arkansas. The outlook is also forecasting an equal chance for above, near, and below normal precipitation across all of eastern Oklahoma and northwest Arkansas. This outlook is primarily based on recent trends and dynamic computer model output, with some input from statistical forecast tools and long-term trends.

According to CPC, ENSO neutral conditions persisted through May 2014, however, above normal sea surface temperatures expanded across the equatorial Pacific Ocean during the month. There is a 70% chance that ENSO conditions will develop during the Summer 2014, and an 80% chance ENSO conditions will develop by Fall 2014. An El Nino Watch has been issued, indicating conditions are favorable for El Nino development over the next 6 months.