Two Storms Bring Drought Improvements in the West

Topsoil moisture remains a concern for some winter wheat areas

Published on: Mar 6, 2014

California this Drought Monitor week saw its most significant storm of the season, while snow and sleet fell across the Midwest, says Brad Rippey, U.S. Department of Agriculture Meteorologist.

According to Rippey, the rain in California’s temporarily eased agricultural irrigation requirements and aided drought-stressed rangeland and winter grains. However, spring and summer runoff prospects improved only slightly, as soils soaked up most of the moisture.

The remainder of the West also experienced stormy weather, with some of the heaviest precipitation occurring in central Arizona.

Meanwhile, a late-winter storm unfolded across parts of the Plains, Midwest, mid-South, and mid-Atlantic States, where varying amounts of snow and sleet fell in advance of a record-setting March cold outbreak. By the morning of March 3, 57% of the contiguous U.S. was covered by snow, according to NOAA’s National Operational Hydrologic Remote Sensing Center.

Topsoil moisture remains a concern for some winter wheat areas
Topsoil moisture remains a concern for some winter wheat areas

Plains
Generally light, wintry precipitation prevented further drought expansion on the central Plains, Rippey reports.

According to the USDA, 31% of the winter wheat in Oklahoma as of March 2 was rated in very poor to poor condition, up from 24% a month earlier. Kansas wheat was 22% very poor to poor, up from 20% at the end of January. Nebraska’s winter wheat was unchanged at 18% very poor to poor.

"When the wheat crop entered dormancy in late 2013, very poor to poor ratings were lower than 10% in all of those states," Rippey explains. "However, some of the perceived harm to the wheat may not have been explicitly caused by drought, but rather the cumulative effects of a harsh winter featuring wild temperature swings, occasional high winds, and exposure to extreme cold without the benefit of a protective snow cover."

Drought was still a concern, though, especially in western sections of those states, Rippey adds. On March 2, topsoil moisture was rated 87% very short to short in Oklahoma, along with 57% in Nebraska and 55% in Kansas. Rangeland and pastures were rated 46% very poor to poor in Oklahoma, reflective of both short- and long-term drought.

In Texas, there were a variety of changes to the drought depiction, both improvement and deterioration. Recent precipitation was heaviest across southern and eastern Texas, where there were widespread changes for the better. General, slight deterioration was noted—with a few exceptions—across northern and western Texas.

According to USDA, the portion of the Texas winter wheat crop rated in very poor to poor condition stood at 46% on March 2, up from 28% in late-November 2013. Additionally, 52% of Texas’ rangeland and pastures were rated very poor to poor on March 2, up from 30% just over 3 months ago, Rippey says.

Spring planting is underway across deep southern Texas – corn was 8% planted, statewide, by March 2 – and Rippey says moisture will be needed soon as fieldwork moves northward. On March 2, statewide topsoil moisture was rated 78% very short to short in Texas, with numbers topping 90% in several northern and western districts.

Mississippi Valley and Midwest
Rain, sleet, and snow in early March mostly arrested the expansion of abnormal dryness across the lower half of the Mississippi Valley.

In the upper Midwest, mostly dry, extremely cold weather covered areas of lingering dryness and moderate to severe drought, resulting in no changes to the depiction," Rippey explains. "Minneapolis-St. Paul, Minnesota reported its 50th day with a below 0°F reading on March 3, the most in any winter at that location since 1977-78."

West Coast and California
Benefits from two storms over California this Drought Monitor week extended northward along the state's coast and into some northern areas of the state, leading to a modest reduction in the coverage of extreme to exceptional drought, Rippey reports.

However, short-term benefits from the storms were mostly offset by still-large, three-year precipitation deficits, low reservoir levels, and a sub-par snowpack. The California Department of Water Sources reported a slight jump in the water equivalency of the high-elevation Sierra Nevada snowpack. The water content, which averaged just 5 inches – 22% of the late-February normal – prior to the two storms, climbed to 8 inches by March 5.

The snowfall was heaviest in the southern Sierra Nevada, where a slight reduction in the coverage of extreme to exceptional drought resulted. Arizona, in particular, also benefited from the second storm, although snow levels were quite high. Due to heavy precipitation, mainly in central Arizona, some reductions in drought intensity were noted.

Some heavy precipitation spilled into northern and western New Mexico, but several other areas of the state remained mostly dry and experienced further drought deterioration. There were few changes to the drought depiction across the Intermountain West, mainly because recent precipitation failed to significantly dent existing seasonal deficits. In the Northwest, however, rain and snow continued to chip away at dryness and drought, Rippey says.

Two Storms Bring Drought Improvements in the West

Source: U.S. Drought Monitor, Meteorologist Brad Rippey