April 30, 2019 National Drought Summary

The discussion in the Looking Ahead section is simply a description of what the official national guidance from the National Weather Service (NWS) National Centers for Environmental Prediction is depicting for current areas of dryness and drought. The NWS forecast products utilizedinclude the HPC 5-day QPF and 5-day Mean Temperature progs, the 6-10 Day Outlooks of Temperature and Precipitation Probability, and the 8-14Day Outlooks of Temperature and Precipitation Probability, valid as of late Wednesday afternoon of the USDM release week. The NWS forecast webpage used for this section is: http://www.cpc.ncep.noaa.gov/products/forecasts/.

Weather Summary: An active weather pattern maintained historically low drought coverage across the contiguous United States, with only a few areas currently experiencing dryness (D0) or moderate to severe drought (D1 to D2). Prior to April 2019, the record-low drought coverage across the Lower 48 States during the 20-year history of the U.S. Drought Monitor stood at 4.52% on May 23, 2017. During the drought-monitoring period ending on the morning of April 30, locally significant precipitation fell in dryness- and drought-affected areas across the Rockies, Intermountain West, northern Plains, and parts of the South. In contrast, little or no precipitation fell in the Far West and the southern Atlantic region.

Northeast: Neither dryness nor drought exists in the Northeast. In fact, significant topsoil moisture surpluses exist in much of the Northeast, according to the U.S. Department of Agriculture (USDA). On April 28, topsoil moisture was rated 100% surplus in Connecticut and 77% surplus in Massachusetts.

Southeast: Short-term dryness (D0) continued to worsen in portions of the southern Atlantic States. In addition, moderate drought (D1) expanded or developed in portions of Georgia and South Carolina. Parts of Florida are being monitored for possible introduction of D0. On April 28, the USDA rated topsoil moisture 32% very short to short in Florida and 22% very short to short in Georgia and South Carolina. Through April, year-to-date precipitation totaled 4.82 inches (43% of normal) in downtown Charleston, South Carolina. January-April totals ranged from 55 to 60% of normal in Georgia locations such as Savannah (7.63 inches) and Alma (8.72 inches). Similarly, the first 4 months of 2019 featured rainfall totaling 60 to 65% of normal in Florida locations such as Sarasota-Bradenton (7.18 inches), Orlando (7.29 inches), and Tallahassee (10.83 inches). In addition, there has been a recent increase in the risk of wildfires in Florida, mainly along and south of the I-4 corridor. The Roger Road Fire, though now fully contained, recently charred 1,127 acres of vegetation in southern Florida.

South: Locally heavy showers swept across the South, especially the central Gulf Coast region and from west-central to northeastern Texas, trimming dryness (D0) and moderate drought (D1). Selected daily-record rainfall totals during the drought-monitoring period included 2.57 inches (on April 25) in Vicksburg, Mississippi; 1.88 inches (on April 24) in Austin, Texas; and 1.37 inches (on April 23) in Oklahoma City, Oklahoma. Dallas-Fort Worth, Texas, recorded 3.57 inches on April 23-24. Lingering pockets of D0 and D1 primarily stretch from southern Texas to the central Gulf Coast.

Midwest: For the tenth consecutive week, the Midwest remained free of dryness and drought. Enough drying took place for corn planting to be 45% complete by April 28 in Missouri, a sharp increase from 16% the previous week. Similarly, corn planting in Iowa was 21% complete on that date, up from 4% on April 21. Still, those values were behind the respective 5-year averages of 55 and 26% in Missouri and Iowa.

High Plains: A new area of abnormal dryness (D0) was introduced in Kansas, where little precipitation has fallen since March 1. Elsewhere, pockets of abnormal dryness (D0) and moderate drought (D1) were limited to Colorado, North Dakota, and Wyoming. Some late-April snow fell in the D0 area of North Dakota, where statewide topsoil moisture rated very short to short stood at 10% on April 28. Coverage of D0 and D1 was reduced in Wyoming and Colorado due to late-April precipitation and generally favorable snowpack values and warm-season runoff prospects.

West: Minimal changes were introduced in the Far West, while slight reductions in the coverage of abnormal dryness (D0) and moderate drought (D1) were made in the Rockies and environs on the strength of late-season precipitation, robust high-elevation snowpack, and increasing confidence in favorable spring and summer runoff.

Alaska, Hawaii, and Puerto Rico: Southeastern Alaska’s region of dryness (D0) and moderate to severe drought (D1 to D2) received mostly light precipitation. However, some heavy precipitation in southernmost Alaska resulted in some slight trimming in the coverage of D2. In Ketchikan, April rainfall totaled 13.73 inches (146% of normal). Farther south, drier-than-normal conditions persisted across much of Hawaii, leading to further expansion of short-term dryness (D0) and moderate to severe drought (D1 to D2). In particular, D2 was expanded northward on Kauai and added in southeastern sections of Maui and the Big Island. Observers in Hawaii’s driest areas have reported degradation in the condition of pastures and other vegetation. Meanwhile, parts of eastern Puerto Rico received heavy rain and experienced local flooding, necessitating a reduction in the coverage of dryness (D0) and moderate drought (D1). In contrast, D1 was expanded in portions of south-central Puerto Rico, where low aquifer levels were among several drought-related problems.

: During the next couple of days, showers and thunderstorms across the nation’s mid-section will gradually shift into the South, East, and lower Midwest. Five-day rainfall totals could reach 1 to 5 inches or more along an axis stretching from the southeastern Plains into the lower Great Lakes region. In contrast, areas west of the Rockies will experience mostly dry weather and a gradual warming trend. During the weekend, a new surge of cold air will arrive across the northern Plains and upper Midwest, accompanied by rain and snow showers.

The NWS 6- to 10-day outlook for May 7 - 11 calls for the likelihood of wetter-than-normal weather nearly nationwide. Below-normal precipitation should be limited to northern California and the Pacific Northwest. Meanwhile, warmer-than-normal conditions across the Southeast and the Far West should contrast with below-normal temperatures in most other regions, including a large area stretching from the Southwest into large sections of the Rockies, Plains, and upper Midwest.

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