This U.S. Drought Monitor week saw improvement in areas of the Northeast, Midwest, and the West.
Very heavy snowfall accumulations (up to 5+ feet in some areas) were observed in downwind locations of Lake Ontario and Lake Erie in New York, and northwestern Pennsylvania. The highest totals were observed downwind of Lake Erie between Erie, Pennsylvania and Buffalo, New York. Farther south, 2-to-8-inch accumulations were observed in areas of the Appalachian Mountains in West Virginia, leading to improvements on the map in drought-affected areas.
Heavy lake-effect snowfall impacted much of Upper Peninsula Michigan as well as areas downwind of Lake Michigan in Northern Michigan and southeastern Michigan. In other parts of the Midwest, light accumulations (1 to 4 inches) were logged in Minnesota, Missouri, Illinois, Indiana, and Ohio.
Dry conditions prevailed across both regions except for light precipitation accumulations in isolated areas of Alabama, Georgia, Florida, South Carolina, and southeastern Texas. In Florida, short-term dryness led to additional expansion of areas of drought in the Panhandle region.
Areas of drought expanded on the map in Virginia, North Carolina, and South Carolina in response to short-term dryness and declining streamflow levels.
Dry conditions prevailed across much of the High Plains; however, some light snowfall was observed in the eastern portion of the Dakotas. Out West, drier conditions prevailed this week across much of the region, although areas of northern Arizona, northern New Mexico, and Colorado experienced snow in the higher elevations.
In terms of reservoir storage in areas of the West, California’s reservoirs continue to be at or above historical averages for the date (Dec. 3) with the state’s two largest reservoirs, Lake Shasta and Lake Oroville, at 113% and 109% of their averages, respectively. In the Southwest, Lake Powell is currently 37% full (59% of typical storage level for the date) and Lake Mead is 33% full (53% of average), with the total Lower Colorado system 42% full as of Dec. 2 (compared to 43% full at the same time last year), according to the U.S. Bureau of Reclamation.
The U.S. Drought Monitor is jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the U.S. Department of Agriculture and the National Oceanic Atmospheric Administration. (Map courtesy of NDMC.)
South
Across the region, generally dry conditions prevailed. On the map, some minor degradations were made in areas of Texas after another dry week, including in the southern North Central, northeastern Edwards Plateau, northeastern South Central, and along the Upper Coast.
According to the latest U.S. Department of Agriculture’s Texas Crop Progress Report (Nov. 25), pasture and range conditions were rated at 62%, poor to very poor, with producers around the state continuing to use supplemental feed for livestock.
In Arkansas, areas of drought were introduced in response to a combination of factors including short-term precipitation deficits, low streamflows, and declining soil moisture.
Midwest
Drought-related improvements continued across areas of Minnesota in response to snowfall received during the past week.
For the week, average temperatures were below normal across the entire region, with the greatest negative anomalies observed in eastern Minnesota where temperatures ranged from 6 to 15 degrees Fahrenheit below normal.
High Plains
Only minor changes were made in the region, including in areas of North Dakota in response to recent snowfall events and above-normal precipitation during the past 30-day period.
Some minor improvements were made also in west-central Kansas, where precipitation has been above normal during the past 30- to 60-day period. For the week, the region was generally dry except for some light snowfall across portions of the Dakotas. In terms of average temperatures for the week, cooler-than-normal temperatures (2 to 25 degrees below normal) prevailed, with frigid temperatures were observed across North Dakota.
West
Areas of the region received mountain snowfall during the past week, including the Southern Sierra Nevada, the eastern Great Basin, ranges of south-central Utah, and the Colorado Rockies.
On the map, storm events during the past several weeks led to continued improvements in drought-affected areas of Colorado and New Mexico, while some degradation occurred in isolated areas of New Mexico, and Wyoming.
Looking at the regional snowpack situation, the Natural Resources Conservation Service SNOTEL network is reporting (Dec. 3) the following region-level (2-digit HUC) SWE levels (% of median): Pacific Northwest 126%, Missouri 75%, Upper Colorado 110%, Great Basin 111%, Lower Colorado 72%, Rio Grande 124%, Souris-Red-Rainy 94%, and Arkansas-White-Red 149%.
Average temperatures were below normal across much of the northern tier of the region, with the greatest departures observed in northern Montana where temperatures ranged from 10 to 25 degrees below normal. Areas of southern Arizona and New Mexico were 5 to 10 degrees above normal.
Looking ahead
The National Weather Service’s Prediction Center 7-Day Quantitative Precipitation Forecast calls for moderate-to-heavy precipitation accumulations ranging from 2 to 4 inches (liquid) across areas of the Pacific Northwest, including the Olympic Mountains and Cascades of Washington.
Areas of eastern Texas, Louisiana, Mississippi, Alabama, western Georgia, and southern Tennessee are forecasted to receive accumulations ranging from 2 to 6+ inches. Elsewhere, light accumulations (<1 inch) are expected in areas of the northern Rockies in the Panhandle of Idaho, northwestern Montana, and locations across the Upper Midwest and Northeast. The Climate Prediction Center’s 6- to 10-day outlook calls for a moderate-to-high probability of above-normal temperatures across much of the West, the Central and Northern Plains states, and the eastern third of the contiguous U.S.
Near-normal temperatures are expected across much of the South and in the Four Corner states. In terms of precipitation, there is a low-to-moderate probability of above-normal precipitation across the eastern third of the contiguous U.S., eastern Texas, eastern portions of the Midwest, and areas along the entire greater U.S.-Canada border.
Below-normal precipitation is expected across portions of the West including California, Nevada, Utah, Arizona, and New Mexico.
David Simeral is with the Western Regional Climate Center.
