Highlights: Consistent weather patterns driven in part by a fading La Niña contributed to a variety of weather extremes. Wet conditions dominated the United States, except across the southern half of the Plains, the lower Southeast, and parts of the Southwest. Warmth covered the South and East, while chilly conditions gripped the northern Plains and much of the West.
According to preliminary information provided by the National Climatic Data Center, the Nation experienced its 42nd-warmest, 12th-wettest spring on record. The United States spring average temperature of 52.3 degrees Fahrenheit was 0.4 degree above the 1901-2000 mean. It was the third-coolest spring in Washington and the fifth-coolest spring in Oregon, but among the ten warmest March-May periods in Delaware, Louisiana, New Jersey, New Mexico, and Texas. Meanwhile, March-May precipitation averaged 8.94 inches, 116 percent of the mean. It was the Nation's wettest spring since 1995. State rankings ranged from the driest spring in Texas to the wettest March-May period on record in Indiana, Kentucky, New York, Ohio, Pennsylvania, Vermont, Washington, West Virginia, and Wyoming.
Regional highlights included a late-season Western storm barrage during March; worsening drought in the Deep South; rampant spring flooding in the Ohio, Missouri, and Mississippi River basins; and multiple severe weather outbreaks in April and May. According to preliminary reports, the 24-hour period ending at 8 am EDT on April 28 became the Nation's deadliest "tornado day" on record (since reliable records began in 1950), with 314 fatalities. This surpassed the 310 deaths of April 3-4, 1974. The Joplin, Missouri, storm of May 22 - with 151 deaths - was the Nation's deadliest single tornado since April 9, 1947, when 181 people perished in Woodward, Oklahoma.
March: Warm, dry weather across the southern Plains and the Southwest adversely affected already drought-stressed pastures and winter grains. From November 28 to April 3, the portion of the winter wheat crop rated in very poor to poor condition climbed from 26 to 61 percent in Texas; 8 to 53 percent in Oklahoma; and 25 to 34 percent in Kansas. In contrast, cold weather dominated the Nation's northern tier, particularly on the northern Plains. Monthly temperatures ranged from as many as 10 degrees Fahrenheit below normal on the northern Plains to more than 5 degrees Fahrenheit above normal in parts of the Southwest. By month's end, the northern Plains' winter wheat had begun to break dormancy, with 70 percent of Montana's wheat crop rated in good to excellent condition on April 3. As the month progressed, flooding generally shifted from the Ohio Valley (and parts of the Northeast) into the upper Midwest. In the latter region, the mid- to late-month combination of precipitation and melting snow led to significant flooding.
Meanwhile, March rainfall provided drought relief in parts of the Southeast.
Heavy precipitation fell from the central Gulf Coast into the Appalachians, as well as the Northeast. Late-month rain eased drought in parts of Florida, with downpours affecting central portions of the peninsula. Elsewhere, a series of exceptional, late-season storms hammered northern and central California and the Northwest, while drought continued to expand and intensify across Arizona and New Mexico. The average water content of the
high-elevation Sierra Nevada snow pack peaked at 48 inches (165 percent of normal) in late March, up from 22 inches in mid-February.
April: Severe flooding developed from the Mid-South into the Ohio Valley. At the same time, a snowmelt-induced flood crest moved along the upper and middle Mississippi River. By month's end, flood waters converged on the confluence of the Ohio and Mississippi Rivers, eclipsing the region's high-water marks established in February 1937. Monthly rainfall totals of 1 to 2 feet were common in the flood-affected areas. A pair of historic tornado outbreaks accompanied the storminess, battering the South April 14-16 and 25-28. Meanwhile in the northern Corn Belt, cool, damp weather and soils hindered the start of the spring planting season. Due to the Midwestern fieldwork delays, only 13 percent of the United States acreage intended for corn was planted by May 1 - the Nation's slowest start since 1995 (11 percent planted). Cool, damp conditions also prevailed across the northern Plains and the Northwest, slowing winter wheat development and hampering spring planting operations. Cool weather was also noted as far south as California. In contrast, heat and drought continued to severely stress pastures, winter grains, and emerging summer crops on the southern Plains. By May 1, approximately three-quarters of the winter wheat crop was rated in very poor to poor condition in Oklahoma (77 percent) and Texas (74 percent), along with nearly half of the crop in Colorado (46 percent) and Kansas (45 percent).
May: Unusually cool weather across the northern Plains and much of the West contrasted with above-normal temperatures in the South and East. Toward month's end, an intense, early-season heat wave built across the South, while favorable warmth overspread the Midwest. Extremely cool weather persisted, however, in California and neighboring areas. Incessantly wet conditions accompanied the cool weather across the northern Plains, slowing winter wheat development, hampering summer crop planting, and triggering widespread flooding in the middle and upper Missouri Valley. By June 5, more than one-quarter of the spring wheat had not yet been planted in North Dakota (69 percent planted) and Montana (73 percent). In stark contrast, drought worsened across the southern High Plains and the Deep South. In both regions, dry, increasingly hot weather severely stressed pastures and rain-fed summer crops. By June 5, at least half of the rangeland and pastures were rated in very poor to poor condition in every southern-tier state from Arizona to Florida, except Alabama. On the southern Plains, drought resulted in early maturation of the winter wheat crop and promoted a rapid harvest pace. Ironically, flood-control efforts extended into drought-affected areas of the lower Mississippi Valley during May, as water from the earlier inundation of the Ohio Valley and the Mid-South worked its way downstream. Farther north, producers in the eastern Corn Belt and far upper Midwest continued to battle wetness in an effort to plant corn and soybeans. By June 5, corn planting was just 58 percent complete in Ohio, while Midwestern soybean planting had not surpassed the halfway mark in Michigan (50 percent planted), Indiana (49 percent), North Dakota (47 percent), and Ohio (26 percent). However, in Midwestern areas where corn and soybeans had emerged, crops benefited from frequent showers and late-May warmth. Elsewhere, cool, showery weather in California, the Great Basin, and the Northwest slowed fieldwork and crop development. Chilly conditions also delayed the Western melt season, leaving substantial high-elevation snow still on the ground by month's end - except in drought-affected areas of the Southwest.