Cold temperatures and light to moderate snowfall over the central U.S., along with rainfall in the Southeast and Northwest marked the U.S. Drought Monitor this week.
The conditions left little change in drought areas, though most changes that were noted were centered on the Southern and Southeastern U.S., said this week's author Eric Luebehusen.
Rainfall in the region was locally heavy, easing or eradicating Abnormal Dryness to Severe Drought from central Mississippi into central and northern Georgia.
Farther north and east, rain generally bypassed the eastern half of the Carolinas, with some increases in drought. Abnormally dry conditions expanded across central and southwestern Arkansas, where rainfall of 50 to 75% of normal over the past 60 days has caused soil moisture and streamflows to decline, Luebehusen wrote.
Cool, showery weather was mostly sufficient to prevent widespread expansion of Abnormal Dryness in the Mid-Atlantic, with rainfall amounts averaging a half inch to locally more than one inch from central Virginia into New England.
Abnormal dryness was expanded, however, to include central Pennsylvania and southern New York. The region continues to cope with pronounced precipitation shortages dating back over the past three months.
There were no changes the drought designation in the Ohio and Tennessee Valleys as increasingly cold weather along with a shallow to moderate snow cover developed over much of the area, Luebehusen said.
Bitter cold along with some shallow to moderate snow cover resulted in no change to the Midwest drought depiction during the monitoring period.
Parts of the Upper Midwest, particularly from the eastern Dakotas into Minnesota, are still contending with significant short-term dryness, with precipitation over the past 90 days totaling a meager 40 to 70% of normal, resulting in unfavorably low soil moisture for winter crops, Luebehusen wrote.
Despite a mostly dry week, the drought depiction over the central Plains remained unchanged due to bitter cold. A historically cold air mass settled over the region, with temperatures averaging 20°F or more below normal. Long-term drought remained entrenched over the central High Plains, where precipitation dating back 36 months has tallied 60 to 75% of normal.
Dry and cold weather in Texas and the Southern Plains resulted in no change to the drought depiction except along the Texas Gulf Coast.
Some D0 was reduced along the southeastern coast of Texas where rainfall totaled locally more than 2 inches, Luebehusen said. Short-term drought remained most intense along the Texas-Oklahoma border west of Wichita Falls, where 90-day precipitation has totaled less than 50% of normal.
In contrast, many of the long-term drought areas from Texas into Colorado have received above-normal precipitation over the past 90 days, but are still wrestling with the impacts of longer-term deficits.
Variable conditions in the Northwest contrasted with ongoing drought elsewhere. A steady plume of Pacific moisture helped produce 1 to more than 4 inches (liquid equivalent) of precipitation in the Cascade Range, providing localized relief from Abnormal Dryness to Severe Drought in southwestern Oregon.
In contrast to the localized Northwestern improvements, Luebehusen wrote, D0 was increased northward in Idaho and far northwestern Montana, where 60-day precipitation has tallied locally less than 60% of normal
Farther south, the 2014-15 Water Year has afforded little drought relief to California. Despite some light to moderate precipitation during the period across central and northern California, the totals still fell short of normal and did nothing to offset the impacts of the ongoing three-year drought, Luebehusen said.
In the Great Basin and Four Corners, there were no changes to this week's drought depiction despite the very poor start to the current Water Year.
Source: Eric Luebehusen, U.S. Department of Agriculture/The U.S. Drought Monitor is produced in partnership between the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, and the National Oceanic and Atmospheric Administration.