Dry period was story of the High Plains week

There was a strong west-to-east temperature gradient this week, with temperatures below normal in the East, particularly in the Midwest and Northeast, and above normal in the West.

Precipitation was scarce across large portions of the nation, with many areas receiving less than 25% of normal precipitation. Areas of localized precipitation fell across the Pacific Northwest, northern Rockies and the Great Lakes region.

Across the West, snowpack remains well below the seasonal average. Even in areas that received snow, low snowpack combined with dry soils and low streamflows led to degradations across the Intermountain West.

Elsewhere, scattered degradations occurred across the South, where another week without precipitation added to growing precipitation deficits, except for localized areas of improvement that continued to benefit from last week’s heavy snowfall. Other isolated areas of improvement were seen in southern New Mexico and in the Midwest.

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

Drought conditions across the South generally continued to worsen this week, as much of the region received little to no precipitation. Temperatures were near to slightly above normal across large portions of the region.

Outside of a few localized improvements in northeast Louisiana and southeast Mississippi from last week’s winter storm, conditions continued to degrade across most of the region. Across the Southern Plains into the Lower Mississippi Valley, one-category degradations were seen across parts of Texas, Oklahoma and Arkansas after another dry week with no meaningful precipitation.

Short- to mid-term precipitation deficits continue to grow and soil moisture continues to decline, along with streamflows.

Midwest

Cold temperatures and limited frozen precipitation led to persistent conditions across the Midwest, outside of areas of localized changes.

Cold conditions kept soils frozen across northern portions of the Midwest, limiting infiltration and preventing recent moisture or snowmelt from entering the hydrologic system. As a result, short-term improvements to soil moisture and streamflows were minimal.

Across parts of the western and central Midwest, minor degradations were introduced as conditions continued to dry, including the introduction of extreme drought in southwest Missouri along the Missouri-Oklahoma border.

In these areas, precipitation during the past several weeks has been limited, and short- and mid-term precipitation deficits continued to grow, combined with declining soil moisture and below-normal streamflows.

High Plains

Conditions across the central and northern High Plains were mostly unchanged as most of the region received little to no meaningful precipitation.

Cold temperatures persisted, and where snow did fall, it remained largely frozen in place, limiting short-term benefits to soils or hydrologic conditions. Conditions across the Wyoming and Colorado Plains continued to deteriorate.

Snow water equivalent remains well below average, with SNOw TELemetry data showing values generally in the 50 to 70% of median range, reflecting how snowpack continues to fall short for this time of year despite recent snowfall.

Severe drought expanded from southeastern Wyoming into northeastern Colorado and a little into the Nebraska Panhandle. Abnormal dryness and moderate drought also expanded across portions of Kansas.

West

Across much of the West, conditions worsened, driven by a deepening snow drought, limited precipitation, and above-normal temperatures that continued to undermine snowpack development.

While some mountain snowfall occurred, amounts were generally modest and failed to keep pace with early February climatological accumulation rates, causing snowpack deficits to expand across much of the region.

The Intermountain West saw conditions intensified as snow accumulation continues to fall well short of what is expected this time of the year. Numerous SNOTEL sites reported SWE below the 15th percentile, with several stations registering the lowest SWE on record for early February.

These snowpack deficits were compounded by limited recent precipitation, declining soil moisture, and below-normal streamflows, particularly across northern Idaho and western Montana and extending into central and southern Montana and Wyoming. Similarly, Colorado and Utah saw conditions deteriorate as SWE levels are well below the median level along with drier soil moisture.

The only improvement across the West occurred in southern New Mexico, where precipitation from earlier storm systems continued to translate into measurable hydrologic response, supporting localized improvements and one-category improvements.

Looking ahead

Over the next five to seven days, an active weather pattern is expected across much of the continental U.S., with several regions showing a strong signal for precipitation.

The heaviest precipitation is forecast from the lower Mississippi Valley northeastward into the Ohio and Tennessee valleys, where widespread totals of 1 to 3 inches are expected, with locally higher amounts possible.

Portions of the central Plains, Midwest, and Great Lakes are anticipated to receive generally 0.5 to 1.5 inches of precipitation during this period. Across the West, precipitation is expected to be widespread from the Pacific Northwest into the northern and central Rockies. Liquid-equivalent totals of 1 to 3 inches are forecast in the Cascades and northern Rockies, with locally higher amounts possible at higher elevations.

Farther south into the Great Basin and Southwest, precipitation becomes more scattered, with most areas receiving less than 0.5 inches, and many locations remaining dry. Drier conditions are expected to persist across California, the northern Great Plains, central and southern Texas, and much of the Florida Peninsula, where little to no precipitation is forecast over the next week.

The Climate Prediction Center’s 6- to 10-day temperature outlook (Feb. 10 to 14) shows a strong and widespread signal for above-normal temperatures across much of the continental U.S.

The highest probabilities of above-normal temperatures are centered over the central and southern Plains, extending northward into the northern Plains and Upper Midwest. Much of the Intermountain West, Rockies and interior West also favors above-normal temperatures.

The outlook favors above-normal precipitation across much of the western U.S., including the Southwest with elevated probabilities extending into parts of the northern Rockies. Much of the central U.S. is expected to see near-normal precipitation.

Lindsay Johnson is with the National Drought Mitigation Center.