Drought continues to spread across the western U.S. this spring. This week, just over 28 percent of the U.S. showed any state of drought on a scale of D0 to D4. Classifications are listed in graphics.
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Compared to the same week last year, categories of D2-D4 are up to 5.65 percent of the continental U.S. compared to only a quarter of a percent last year. This figure jumped a full percent last week, nationally.
West
The Pacific Northwest and Northern California are showing increasingly worse conditions. Most of the western U.S. received little to no rain, except for small pockets of the Pacific Northwest and the Southwest.
Temperatures were generally above normal, with record-setting heat across parts of the Southwest and daily highs of 10 to 20 degrees above normal. The heat and dry weather led to deteriorating conditions across several states.
In Oregon, severe drought (D2) expanded near Portland and in the north-central part of the state in response to drying soils, vegetation stress, and stream flow and groundwater declines. Precipitation for the water year ranks as the third driest in the Portland station’s 89-year period of record.
In northern California, moderate drought (D1) expanded. While the state coordination committee noted that reservoir levels are acceptable, precipitation deficits are less than 50 percent of normal for the water year, stream flow values are low, and rangeland grasses have been affected by the lack of moisture and heat.
Likewise, parts of central Nevada also saw expansions to D1 and the introduction of D2 in response to increasing moisture deficits, declining stream flow and groundwater levels, and vegetation stress. The only improvements on this week’s map included minor reductions in D1 in Oregon and D0 in Washington in response to locally heavy rainfall.
The High Plains
Temperatures across the High Plains were generally warmer than normal last week with departures of 2 to 6 inches above normal. Much of the region received less than 0.5 inches of precipitation.
Exceptions included parts of eastern North Dakota, South Dakota, and Nebraska, with totals of more than 1 inch, and eastern Kansas, with amounts of more than 2 inches—nearly 200 percent of normal. The warm, dry conditions led to an expansion of abnormal dryness (D0) in the Dakotas, southwest Nebraska, northwest Kansas, and eastern Colorado.
Additionally, moderate and severe drought (D1 and D2) expanded over Colorado’s eastern plains. This area has failed to receive the timely spring rains needed, resulting in reductions in soil moisture, stream flow, and vegetation health.
Across the entire High Plains region, local drought experts are discussing the emerging dryness and closely monitoring the situation as planting begins, and the need for moisture increases. — Charles Wallace, WLJ correspondent
