May 2010 Summary and Highlights

May 2010

Tulsa: May 2010 was 45th warmest (69.7°F, since 1905) and the 55th wettest (5.23", since 1888) May on record.

Tulsa: Spring 2010 (March-April-May) was 32nd warmest (61.2°F, tied with 2000 and 1959, since records began in 1905) and the 47th driest (10.56", since 1888) Spring on record.

Fort Smith: May 2010 was the 19th warmest (72.2°F) and 45th driest (2.25") May since records began in 1882. Coincidentally, the Spring 2010 temperature tied the temperature from 100 years ago in 1910.

Fort Smith: Spring 2010 (March-April-May) was the 25th warmest (62.7°F) and 20th driest (8.45") Spring since records began in 1883.

After no tornadoes occurred January through April, over two dozen tornadoes affected portions of eastern Oklahoma and northwest Arkansas during 3 significant weather events in May 2010: May 10, May 13, and May 19.

Moderate flooding occurred along Polecat Creek near Sapulpa on May 20. Moderate flooding also occurred along the Neosho River near Commerce on May 15 and minor flooding occurred at this location on May 21.

A record high daily temperature of 91°F was tied on May 6, 2010 at Fort Smith. The previous record was in 1952.

According to the Oklahoma Climatological Survey (OCS), southeast OK ranked as the 14th driest Spring (March-April-May) since records began in 1921.

Rainfall totals for May 2010 ranged from around 3” to near 10” across eastern Oklahoma and northwest Arkansas. While isolated areas received high totals this month, overall, much of the area received near to below normal rainfall for the month.

The Climate Prediction Center (CPC) outlook for June 2010 (issued May 31, 2010) indicates an enhanced chance for above median precipitation and above average temperatures. According to CPC, this outlook is based primarily on the expected weather conditions during the first half of June from shorter-term computer models and then modified by longer-term signals including local soil moisture conditions and long-term temperature trends. For the 3-month period Jun-Jul-Aug 2010, CPC is forecasting a slightly enhanced chance for below average temperatures and a slightly enhanced chance for above median precipitation (outlook issued May 20, 2010). This temperature outlook is based on above normal soil moisture, long-term temperature trends, and computer models, while the precipitation forecast is based on several statistical tools. (outlook issued May 20, 2010).

Sea-surface temperatures in the equatorial Pacific are transitioning from El Niño conditions to ENSO-neutral conditions. According to CPC, many models are predicting ENSO-neutral conditions to continue, though there is a growing possibility of La Niña developing during the second half of 2010. These conditions also play a role in the above normal hurricane season forecast issued May 27, 2010 by the NWS. An La Niña Watch has been issued.

According to the Drought Monitor on May 25, 2010, no drought conditions exist across eastern OK or northwest AR.