Some precipitation has relieved drought areas in the Northwestern U.S., but extreme drought remains in California and Arizona, David Miskus of the National Oceanic and Atmospheric Administration reports in the latest U.S. Drought Monitor, released Thursday.
A series of winter storms brought wintry precipitation to the Midwest in the form of light to moderate snow, to the Southeast in the form of severe icing in Georgia and South Carolina; and in the Northeast as heavy snow, Miskus notes.
Miskus says specifically that precipitation in the northern states has nearly reached surplus during the past 60 days, building a snow cover of 1 foot to 2.5 feet deep with a liquid water equivalent of 2-4 inches in northeastern Iowa, northern Illinois, and most of Wisconsin and Minnesota.
Precip has led to a slight reduction of severe drought in central Iowa and southwestern Wisconsin; moderate drought removed in southwestern Iowa and southwestern Wisconsin, and abnormal dryness erased in northeastern Iowa.
In contrast, drier weather and less snow cover in northwestern Iowa called for the merging of the two separate moderate drought areas.
Also in contrast to the areas receiving precipitation, dry and mild weather continued in the southwestern quarter of the U.S., further degrading conditions there. A cluster of extreme drought areas hangs on in Texas, New Mexico and Oklahoma.
Growing short-term dryness interlaced with long-term drought led to a slight degradation of conditions in Texas, particularly in south-central and southeastern, sections and in the northern Panhandle. Similarly, abnormal dryness was slightly expanded eastward in southeastern and central Oklahoma where the 30-day precipitation missed.
A one-category degradation was made in southwestern Arizona, southern Nevada, central and southern Arizona and into western New Mexico.
With half to one-inch equivalent precipitation falling the past 30 days across the central Plains, plus relatively low normal precipitation amounts for this time of year, no drought changes were made in the area, Miskus says.
In Louisiana, two weeks of wet and cool weather have eased or eliminated short-term deficiencies allowing for a general one-category improvement in southern and eastern parts of the state.
Last week’s overdue and welcome moisture was short-lived for most of California as the weather pattern shifted and brought moderate to heavy precipitation northward to the Pacific Northwest. Extreme northern California did benefit from this week’s moisture, however.
Along coastal Oregon and Washington and in the Cascades, widespread heavy precipitation was enough to make a general 1-category improvement in the drought, especially since the dryness was more short-term than compared to California’s multi-year drought, Miskus writes. Unfortunately, the moisture was accompanied by mild air, and most of the precipitation that fell on the southern Cascades was rain and not snow. As a result, southern Oregon’s basin average snow water content remained low, between 30-39% of normal on Feb. 18, and no changes were made here, Miskus notes.
Southern California missed out on both week’s precipitation while unseasonable warmth persisted, he said, further degrading conditions similar to the Southwest.
Ranchers are also reducing their herds due to the lack of water and food sources. As of Feb. 18, the Sierra Nevada basin average snow water content ranged from 32 to 53% of normal.
"Widespread heavy precipitation is badly needed in this state as the normal wet season nears its end by early to mid-spring," Miskus comments.
Source: David Miskus, U.S. Drought Monitor