March 2011 Climate and Hydrology Highlights

March 2011

March 2011 was extremely dry across the HSA, which lead to an increase in wildfire activity and worsening drought conditions by the end of the month.

Tulsa: March 2011 was 39th warmest (52.5°F, tied with 1933; since 1905) and the 20th driest (1.00"; since 1888) March on record.

Tulsa: Daily records set this month included a record warm min temperatur e of 65°F set on 3/17/2011 (previous record 59°F in 1992*) and a record warm mean temperatur e of 74°F set on 3/17/2011 (previous record 71°F in 1994).

Fort Smith: March 2011 was the 20th warmest (56.2°F) and the 5th driest (0.80", tied with 1941, 1971) March since records began in 1883.

McAlester: Only 0.52" of rain fell at McAlester Regional Airport in March 2011, which ranks as the driest March on record since records began in 1954. The previous record was 0.62" in 1954.

Rainfall totals for March 2011 ranged from around 0.10” in portions of Okfuskee, Okmulgee, and Pittsburg Counties to near 4” in far northeast OK. However, most of the HSA received 0.50” to 2.0” of rain this month, which equates to 2”- 4” below the normal March rainfall. All of eastern OK and northwest AR received below normal rainfall this month, with locations southwest of a Pawnee to Tulsa to Fort Smith line receiving 25% or less of the normal March rainfall. Sadly, portions of Okmulgee and Pittsburg Counties had less than 5% of their normal March rainfall.

According to the Drought Monitor from March 29, 2011, extreme (D3) drought conditions were affecting Choctaw and southern Pushmataha Counties in southeast OK. Severe (D2) drought conditions were affecting most of southeast OK and west central AR south of I-40, in addition to Okfuskee and Creek Counties. Abnormally dry (D0) and moderate drought (D1) conditions were affecting all of the remainder of eastern OK and northwest AR.

Wildfires increased across the region on the 10th, with 33 wildfires burning a total of 1186.5 acres across eastern Oklahoma. One fire in Latimer County burned 160 acres while another fire in Haskell County burned 145 acres. Significant and widespread wildfire activity occurred across eastern OK on the 11th as drought conditions continued across this area. Strong southerly winds with gusts of 20-30 mph, combined with temperatures in the low to mid 70s and relative humidity values below 20%, led to dangerous fire weather conditions. 42 fires burning over 8600 acres were reported in eastern Oklahoma on the 11th. Large fires were reported in Pushmataha County (1600 acres), Latimer County (1200 and 350 acres), Le Flore County (107 acres), and Pittsburg County (640, 620, and 233 acres). A fire in Beggs (Creek County) burned numerous structures and the Oklahoma National Guard had to provide water drops via Blackhawk helicopters. An additional 100+ acre fire occurred in Le Flore County (Sugarloaf Mountain area) on the 12th.

Wildfire continued to be a problem on the 20th as gusty southerly winds, temperatures in the 80s, and ongoing drought conditions once again increased the fire weather danger. 70 fires, burning a total of 3910 acres, were reported on the 20th in eastern OK. 10 large fires were reported across Pittsburg, Latimer, Haskell, Adair, and Pushmataha Counties.

According to the Oklahoma Climatological Survey (OCS) for March 2011, northeast OK ranked as the 26th driest, east central OK ranked as the 6th driest, and southeast OK ranked as the #1 driest March since records began in 1921. For the water year so far (October 1, 2010 - March 31, 2011), northeast OK ranked as the 8th driest, east central OK ranked as the 4th driest, and southeast OK ranked as the 2nd driest water year on record.

Outlook

The Climate Prediction Center (CPC) outlook for April 2011 (issued March 31, 2011) indicates a slightly enhanced chance for above average temperatures and an equal chance for above, near, and below median precipitation across all of eastern OK and northwest AR. The 1-month outlook is consistent with La Niña impacts across the southern Plains during this time of year.

For the 3-month period Apr-May-Jun 2011, CPC is forecasting a slightly enhanced chance for above average temperatures along the Red River and equal chances for above, near, and below normal temperatures elsewhere across eastern OK and northwest AR. This outlook also calls for an equal chance for above, near, and below median precipitation (outlook issued March 17, 2011). The 3-month outlook is consistent with La Niña impacts across the southern Plains during this time of year.

According to CPC, weak La Niña conditions were observed at the end of March as negative sea surface temperature anomolies continue to weaken in parts of the Pacific Ocean. Current computer models indicate that La Niña conditions will continue to diminsh through the remainder of spring 2011, with ENSO-neutral conditions likely by June 2011. A La Niña Advisory continues, meaning that La Niña conditions are observed and are expected to continue.