Highlights: In stark contrast to 2012, cold, wet weather hindered spring planting operations across the northern Plains and much of the Midwest. Significant planting delays also occurred in the Mississippi Delta. Peak periods of Midwestern wetness occurred in April and late-May, resulting in separate rounds of flooding in the middle Mississippi Valley and environs. By the end of spring, lingering drought had been virtually eradicated from the States bordering the Mississippi River to the Atlantic Seaboard. Meanwhile, drought persisted or intensified from California and portions of Oregon to the southern half of the High Plains.
Spring warmth accompanied the Western dryness, leading to a mostly disappointing finish to the snow-accumulation season and a premature snow-melt period. Only the northern tier of the West escaped without drought impacts. East of the Rockies, spring was slow to arrive, with snow falling in parts of the upper Midwest through April and into early-May. In Minnesota and North Dakota, for example, it was the coldest spring since 1950.
Historical Perspective: The spring of 2013 was overall cool and slightly wet. The Nation's average temperature of 50.5 degrees Fahrenheit was 0.5 degree below the long-term mean, while the average precipitation of 7.92 inches was 103 percent of normal. These numbers represented the 38th-coolest, 45th-wettest March to May during the 119-year period of record.
Despite the overall cool pattern, spring warmth prevailed west of the Rockies. California experienced its seventh-warmest spring, but 14 states from the Plains and upper Midwest into the Southeast had one of their ten coolest March-May periods. Meanwhile, State precipitation rankings ranged from the second-driest spring in New Mexico to the wettest spring on record in Iowa. Spring precipitation averaged 17.61 inches (196 percent of normal) in Iowa, supplanting the March-May 1991 record of 15.33 inches. Elsewhere, California noted its eighth-driest spring, while it was among the ten wettest March-May periods in Wisconsin, Illinois, Michigan, North Dakota, and Minnesota.
March: The persistence of a large high-pressure system over the North Atlantic led to a southward displacement of the polar jet stream across the central and eastern United States. That resulted in a steady delivery of cold, Canadian air, leading to below-normal March temperatures in most areas from the Plains to the East Coast. Monthly temperatures averaged more than 10 degrees Fahrenheit below normal in parts of North Dakota and neighboring areas. In contrast, mild weather covered much of the West, leading to some premature melting of high-elevation snow packs. However, the Western warmth also promoted spring fieldwork and crop development.
The North Atlantic blocking high also slowed the normal progression of storm systems, leading to an active weather pattern in some parts of the country. In particular, significant precipitation fell in several regions, including portions of the northern Plains, Midwest, and Ohio Valley. On several occasions, precipitation fell in the form of late-season snow. However, precipitation largely bypassed several areas, such as the southern Plains, the Gulf Coast region, and parts of the Northeast. Most of the West also experienced drier-than-normal weather, fueling concerns about spring and summer water supplies.
Agricultural highlights included the lack of spring fieldwork in the Midwest - in stark contrast to March 2012 - and continuing stress on rangeland, pastures, and winter wheat from South Dakota to Texas. In parts of the Midwest, temperatures during March 2013 averaged more than 20 degrees Fahrenheit below those observed a year ago. On the drought-stricken central Plains, even a moderately wet March failed to substantially improve subsoil moisture levels or crop conditions. On the southern Plains, a return to dry conditions coupled with with late-month freezes maintained or increased stress on winter wheat. Late-March freezes also struck much of the remainder of the South, threatening emerging summer crops, jointing to heading winter wheat, and fruit crops. However, Southern crop development was far behind last year's pace due to persistently cool conditions, helping to reduce the overall threat of freeze injury.
April: Record-setting cold weather across the Plains and upper Midwest maintained low soil temperatures through April. The cool soils, combined with substantial April precipitation (rain and snow) across the eastern Plains and much of the Midwest, resulted in the slowest United States corn planting pace since 1984, with just 5 percent of the crop in the ground by April 28.
In fact, major flooding developed during the second half of April in the middle Mississippi Valley, with record-high water levels observed along a significant stretch of the Illinois River. From just south of Moline, Illinois, to just north of St. Louis, Missouri, the Mississippi River achieved one of its five highest crests on record, behind 1993 and 2008, and in some cases, 1973 and 2001.
Cold conditions also adversely affected the Plains' already drought-stressed winter wheat. Periodic freezes struck as far south as the southern High Plains, contributing to sharp declines in wheat condition ratings. For example, the portion of the Texas wheat rated very poor to poor rose from 44 to 74 percent between March 17 and May 5. Wheat condition declines were also noted during April in Colorado, Kansas, and Oklahoma. Part of the increased stress on wheat was caused by drought intensification, particularly across the central and southern High Plains. Meanwhile, a delayed snow-melt season and cold conditions hampered planting of spring-sown small grains across the northern Plains.
Fieldwork and crop developmental delays were not only restricted to the Plains and Midwest. Significant planting delays were also noted in the Mississippi Delta, where crops affected included cotton, rice, and soybeans. In Mississippi, planting progress by May 5 for those three crops reached 2, 14, and 15 percent, respectively, compared to the 5-year averages of 35, 80, and 60 percent. In contrast, very warm, mostly dry weather promoted a rapid pace of fieldwork and crop development from California into the Southwest.
May: Periods of heavy rain hampered fieldwork across the northern Plains and the Midwest, except for a brief mid-month stretch when producers achieved a record-tying corn planting pace. From May 13-19, corn planting advanced from 28 to 71 percent complete, matching the weekly record of 43 percentage points set from May 4-10, 1992. Midwestern rainfall intensified toward month's end, leading to a second round of spring flooding in the middle Mississippi Valley. Previously, flooding had struck the same general area of the Corn Belt in late April. By June 2, more than half of the intended soybean acreage had not yet been planted in several Midwestern States, including Missouri (64 percent left to plant), Wisconsin (57 percent), Iowa (56 percent), and Illinois (51 percent).
Cool, wet conditions also hampered planting on the northern Plains, where only 64 percent of North Dakota's spring wheat had been planted by June 2. Farther south, a stark contrast developed across the central and southern Plains, with worsening drought on the High Plains and heavy showers in eastern portions of the region. As drought entered a third year on the southern High Plains, concerns existed with respect to the health of rangeland, pastures, and emerging summer crops.
Farther west, drought also remained a significant presence across the Southwest, leading to unusually poor rangeland and pasture conditions in New Mexico (92 percent very poor to poor on June 2), Arizona (75 percent), and California (65 percent). Several Western States, including Arizona, Colorado, Nevada, New Mexico, and Oregon, continued to deal with the combination of sub-par spring runoff and below-normal reservoir storage. May showers dampened the northern tier of the West, but parts of the interior Northwest turned unfavorably dry.
Elsewhere, abundant rain fell across much of the South and East, except in a few small areas. However, there were enough breaks between showers - especially in the Mississippi Delta - for previously delayed planting activities to advance. Some of the most substantial rain fell across northern New England, Florida's peninsula, the southern Appalachians, and the Mid-South.