NOAA’s Spring Outlook, released March 20th, warns that drought conditions are set to worsen or develop across large portions of the West and south-central Plains from April through June.
As of mid-March, moderate to exceptional drought already covers 55% of the continental United States. NOAA’s Climate Prediction Center says conditions are expected to deteriorate further, particularly across the Pacific Northwest, Great Basin, central Rockies, and Southwest. The West’s situation is compounded by well-below-normal snowpack across most of the country.
“Drought conditions worsened or developed for much of the Great Plains, Lower Mississippi Valley, and Southeast U.S. due to warmer and drier than normal conditions this winter.” – Jon Gottschalck, chief of the Operational Prediction Branch at NOAA’s Climate Prediction Center.
A transition from La Niña to ENSO-neutral conditions is also underway, which NOAA says is one of the key factors shaping the spring forecast alongside low snowpack and dry soils.
Drought Risk
Above-normal temperatures are favored across the majority of the country, with the strongest signal centered over the Southwest and Intermountain West. The warmth extends eastward through much of the Plains, Mississippi Valley, Ohio Valley, Tennessee Valley, Southeast, and southern Mid-Atlantic.
At the same time, below-average precipitation is forecast for the Pacific Northwest, parts of the Great Basin, Southwest, central High Plains, and most of the Rockies. The greatest likelihood of dryness runs from the Pacific Northwest down through the central Rockies. However above-normal precipitation is expected for western Alaska, the eastern Great Lakes, mid-Atlantic, and parts of the Southeast.
Flood Risk
Despite the drought picture, NOAA says overall flood risk across most of the continental U.S. is normal to below normal this spring. A dry, warm winter left soils parched across much of the eastern U.S., reducing the threat of rainfall-driven flooding. Low snowpack further limits the risk of snowmelt-driven flooding.
The Red River of the North and lower Ohio Valley are expected to see their typical annual flooding. NOAA also cautions that heavy rainfall can still trigger major flooding events quickly, even in areas with a generally low risk.
“We anticipate typical spring flooding this year over portions of the Greater Mississippi River Basin, but the risk for widespread significant flooding is low.” – Ed Clark, director of NOAA’s National Water Center.
For the latest flood watches and warnings, visit weather.gov.
