California and National Drought Summary for April 2, 2019
Summary
April 4, 2019 - Large portions of the continental United States remained free of drought or abnormal dryness this week. The Northeast was completely free of drought or abnormal dryness, as was the Midwest, where significant river flooding concerns continued. Short-term dryness continued in parts of central and western Texas, with some moderate and severe drought shifting northward, while widespread rain in southern Texas led to improvements in conditions there. Short-term precipitation deficits in southern Alabama, southern Georgia, southern Louisiana, the Florida Panhandle, and South Carolina led to the expansion of abnormal dryness and moderate drought in some of these areas. Moderate drought was also expanded in parts of north-central Washington in response to short-term precipitation deficits there. Another dry week in Hawaii led to degradation in drought conditions on most of the islands.
Northeast
Near-normal temperatures occurred in much of the Northeast this week, with below-normal precipitation common except for northern Maine and areas adjacent to Lakes Ontario and Erie. The entire region remained free of drought or abnormal dryness this week.
Southeast
Relatively cool conditions prevailed in the Carolinas, Georgia, and Alabama, while temperatures in Florida were closer to normal this week. Moderate rain fell in parts of northern Florida, southern Georgia, and South Carolina this week, but otherwise, the region was generally dry. In response to short-term dryness over the past 1 to 3 months, areal coverage of moderate drought expanded into the western Florida Panhandle, the Alabama Gulf Coast, parts of southern Alabama, and southwestern Georgia. Short-term dryness in the past 1 to 3 months also led to moderate drought expanding a bit in southeastern parts of Georgia and South Carolina.
South
Aside from southern Texas and northeastern Oklahoma, much of the region was dry over the past week. Temperatures were below normal in most of the region, except for southwestern Texas and the western Texas Panhandle. Moderate drought was added this week in southwestern Louisiana and in the Baton Rouge area because of short-term precipitation deficits over the past few months. Very dry conditions over the past 3 months led to moderate drought expanding into the Austin, Texas, area. Severe drought shifted northward in parts of south-central Texas in response to changes in short-term precipitation deficits there. After a widespread half-inch or more of precipitation this past week, short-term precipitation shortages were alleviated enough for widespread improvement in drought conditions in southern Texas. Elsewhere, some short-term dryness was taking place in Arkansas and Tennessee, but this was outweighed by longer-term precipitation surpluses.
Midwest
Moderate to heavy precipitation fell across much of the southern part of the region this week, particularly from northern Missouri eastward into Ohio. Temperatures this week were moderate to slightly below normal. The region remained free of drought or abnormal dryness, while significant flooding remained a concern.
High Plains
Widespread precipitation fell across much of Nebraska and eastern Kansas this week while most of the rest of the region experienced drier weather. On the whole, temperatures were relatively close to normal in the region, with a cold pocket in northwestern Nebraska and a few warmer areas showing up in the western Dakotas. Aside from a reduction in abnormal dryness around Colorado Springs in response to decreasing long-term precipitation deficits, no changes were made to the map this week east of the Continental Divide, and the High Plains remained nearly devoid of drought or abnormal dryness.
West
Widespread precipitation affected northern California, western Oregon, and the northern Sierra Nevada this week. Precipitation also fell in the mountains north of the Snake River Valley in Idaho, southwestern Montana, northern Utah, and central Wyoming. Relatively warm conditions prevailed along the Pacific Coast, and in southern California, Arizona, and New Mexico. Elsewhere, temperatures were generally near normal. Moderate drought was expanded in parts of north-central Washington where precipitation deficits over the last 1-3 months led to the development of moderate drought. Low to very low snow water equivalent is also evident in the Idaho Panhandle and in northwestern Montana, and while this has not yet developed into moderate drought, abnormally dry conditions continue here. Abnormal dryness was reduced in the San Luis Valley in Colorado, where long-term precipitation deficits continued to abate.
Alaska, Hawaii, and Puerto Rico
Moderate and severe drought continued this week in southeastern Alaska, where precipitation deficits since January 1 range from 4 to 16 inches below normal. Above-normal temperatures have led to early runoff and high streamflow in some areas, but hydro-electric power production is still struggling in the region, and low water levels and high water temperatures are threatening salmon. Dry weather during the past week in most of Hawaii, particularly on the leeward sides of islands, continued the trend of dry conditions from March and led to deteriorating conditions for vegetation. On most islands, some areas saw a 1-category degradation from normal conditions to abnormal dryness or from abnormal dryness into moderate drought. Severe drought remained in southwestern Kauai. No changes were made in Puerto Rico this week.
Looking Ahead
Widespread precipitation is forecast this week from the Central Plains eastward through the East Coast. The heaviest amounts are forecast in eastern Texas and Arkansas and in the central Gulf Coast states. Precipitation is also forecast in the Sierra Nevada, northwestern California, western Washington and Oregon, and mountainous areas of Wyoming, northern Utah, and Idaho. Widespread above-normal temperatures are forecast over the next week, particularly in the central continental United States.
Author(s):
Curtis Riganti, National Drought Mitigation Center
Dryness Categories
D0 Abnormally Dry—used for areas showing dryness but not yet in drought, or for areas recovering from drought.
Drought Intensity Categories
D1 Moderate Drought
D2 Severe Drought
D3 Extreme Drought
D4 Exceptional Drought
Drought or Dryness Types
S Short-Term, typically less than 6 months (e.g. agricultural, grasslands)
L Long-Term, typically greater than 6 months (e.g. hydrologic, ecologic)
Source: National Drought Mitigation Center
