May 2008 Climate Summary

Region Breakdown

May 2008 was a very active month for extreme precipitation amounts on both ends of the spectrum while temperature remained with temperatures at or below Normal (0-6 °F below) for the majority of the High Plains Region. The exception to the Normal or below Normal temperatures occurred in Eastern Colorado and Southwestern Kansas where warmer than Normal temperatures (2-4 °F above) were experienced. The most extreme departures from Normal temperature occurred in Southwestern Kansas (4 °F above) and Eastern North Dakota (8 °F below).

Areas where near Normal or below Normal temperatures (0-4 °F below) occurred received above Normal amounts of precipitation, while areas where above Normal (2-4 °F above) and extreme below Normal (6-8 °F below) temperatures occurred received 25% or less the normal precipitation for the month. The areas that received above Normal precipitation generally did so to the extreme with widespread areas reporting 200%+ the Normal precipitation for the year, with areas receiving below Normal precipitation also doing it to the extreme as those areas reported 25% or less the Normal precipitation amounts.

Drought persists over areas of North Dakota, Northwestern Nebraska, Southwestern Wyoming, and along the Colorado/Kansas border. Seasonal outlooks indicate that all areas of drought in the region should improve through the summer. Over the last month widespread retreat of drought areas occurred. Categorization changes include D3-D2 in Northwestern Nebraska, D1-D0 in Southwestern Nebraska, areas of D1, 2, and 3 were eliminated in South Dakota, and D1-D0 and none in Central Wyoming. One area did experience intensification through the month of May, the Kansas-Colorado border. The area went from D2-D3 categorization by the end of May.

Precipitation Summary

May proved to be a diverse month for the High Plains Region. Two distinct areas, Colorado and North Dakota, were characterized by well below normal precipitation amounts. Areas received as little as 5-25% normal precipitation for the month. On the other end of the spectrum were three areas, Western South Dakota, Central and Eastern Nebraska, and North Central and Southern Kansas, that received well above normal for the month. Portions of each area received as much as 300% the normal with wide spread areas of 100+% normal.

The dynamic setup for the region was said to be characterized by early spring dynamics with late spring thermodynamics. That setup resulted in system after system producing severe weather across large portions of Wyoming, Western South Dakota, Nebraska, and North Central and Southern Kansas.

On the 22^nd/23^rd of May, a particular system swept through Central Nebraska dumping 6 ¼ inches (158.75 mm) of rain in the McCook, NE area. Of that rainfall amount, over 5 inches (127 mm) was recorded on the 23^rd. That same system dropped a little over 4 inches (101.6 mm) in Grand Island, NE with 2 ½ inches (63.5 mm) occurring on the 23^rd.

Just a few days later on the 26^th of May South Central Kansas experienced a series of thunderstorms that dropped large amounts of precipitation. Wichita, KS reported nearly 3 ¼ inches (88.9 mm) while Hutchinson, KS reported nearly 2 ¼ inches (57.15 mm).

The other extremes of the month included Montpelier, ND recording .38 inches (9.65 mm), Hugoton, KS recording .20 inches (5.08 mm), and Las Animas, CO recording .42 inches (10.67 mm), all well below a quarter of normal for each respective station.

Climate Outlook

With La Nina ENSO conditions shifting towards neutral and expected to stay neutral through the Northern Hemisphere summer months, NOAA forecasters are calling for dryer than normal conditions for the majority of the northwest portion of the High Plains with accompanying higher than normal temperatures for the western portion of the High Plains. This summer outlook is produced by scientists at the NOAA Climate Prediction Center. For more information, visit http://www.cpc.ncep.noaa.gov.

Drought Watch

Drought conditions remain in over the majority of North Dakota, Northwest Nebraska, Southwest Wyoming, and along the Colorado, Kansas border. Improvement continues in portions of Eastern South Dakota, Northwest Nebraska, and Southwest Wyoming while drought conditions continue to worsen along the Colorado-Kansas border. According to the U.S. Seasonal Drought Outlook released on June 5^th, improvement on drought conditions is expected to continue in all areas of the High Plains, with the least improvement expected in Southwest Wyoming, Southeast Colorado, and Southwest Kansas.