National drought summary reported
A series of Pacific low pressure and frontal systems moved across the western contiguous U.S. (CONUS), according to the U.S. Drought Monitor (USDM) during the week of Feb. 22-28.
The weather systems dropped copious amounts of rain and snow across the West, especially over the Sierra and coastal ranges and the Rocky Mountains.
The weather systems reintensified as they crossed the Plains and moved into the Midwest, tapping Gulf of Mexico moisture to spread several inches of rain over northeast Texas to the Appalachians and Ohio Valley, with several inches of snow falling in the below-freezing air across the northern tier states from the Dakotas to New England.
Temperatures averaged cooler than normal across the snowy northern states, across the central to northern Plains and in the West. Little to no precipitation fell across the Gulf Coast, western portions of the Southern and Central Plains and over the Northern Plains near the Canadian border.
Wetter-than-normal conditions were widespread across the rest of the West, parts of the Northern and Central Plains, the Northeast and much of the Midwest.
Drought or abnormal dryness contracted or reduced in intensity where it was wet across much of California and other parts of the West and Plains, as well as part of the Great Lakes region.
The High Plains
The High Plains region experienced a patchwork pattern of precipitation this week.
The Rocky Mountain areas of Wyoming and Colorado, as well as the eastern half of Kansas, received one-half of an inch to two inches or more of precipitation.
Additionally, one-half of an inch fell across South Dakota and northern and eastern parts of Nebraska.
However, North Dakota, eastern Colorado and adjacent parts of Kansas and Nebraska were drier, receiving less than one-half of an inch.
This winter has been particularly wet for central to northern portions of the High Plains region, while Kansas and parts of southeast Colorado have missed out on the above-normal winter precipitation.
The heat and dryness of last summer and fall dried out soils, and as winter set in soils froze in the northern states, locking dryness into place.
The precipitation this week and in earlier weeks resulted in contraction of moderate to severe drought in the Dakotas to Nebraska, and an exceptional drought in Nebraska. However, abnormal dryness was kept to reflect the leftover dry state of the frozen soils.
Abnormal dryness contracted in parts of Colorado and Wyoming, and abnormal dryness and moderate to exceptional drought contracted in eastern Kansas.
As the Feb. 22-28 USDM week ended, one weather system was moving across the Northeast and another was slamming into the West.
More Pacific weather systems will follow during March 2-7, bringing one-half of an inch or more of precipitation to the West Coast and higher elevations of the West, parts of the Great Plains and much of the CONUS to the east of the Plains.
Another four inches or more of precipitation can be expected for the Sierra
Nevada and coastal ranges and from northeastern Texas and eastern Oklahoma to the Ohio Valley and southern Appalachians
An inch or more of precipitation should be widespread from eastern Kansas to the southern Great Lakes and from the eastern Great Lakes to the Northeast and Mid-Atlantic states.
Western and some central parts of the Great Plains – especially Nebraska – western Texas and southeast New Mexico, as well as southern California to the Great Basin, are forecast to receive less than one-half of an inch of precipitation.
Temperatures are predicted to be warmer than normal in the South and Southeast to cooler than normal in the West. A cooler- and wetter-than normal pattern is likely for March 8-15 across the CONUS.
Richard Heim and Rocky Bilotta are scientists and authors at the National Oceanic and Atmospheric Administration’s National Centers for Environmental Information. This article was provided by Chris Poulsen, geographic information systems manager for the Drought Mitigation Center. For more information, visit droughtmonitor.unl.edu.