Map released July 25, 2019 | Data valid July 23, 2019
This week’s drought summary: The remnants of Hurricane Barry drifted northward into the Ohio Valley, delivering widespread rainfall that mostly benefited summer crops but also sparked some flash flooding. Some of the heaviest rain, locally 4 to 8 inches or more, fell in portions of the Mississippi Delta States. Meanwhile, several cold fronts crossed the North, generating showers and locally severe thunderstorms from the northern Plains into the Northeast. Some of the highest totals, as much as 2 to 4 inches or more, fell from South Dakota into Michigan, locally accompanied by high winds, large hail, and isolated tornadoes. Meanwhile, much of the central and eastern U.S. experienced a brief period of heat and high humidity levels, followed by cooler weather and scattered to widespread showers and thunderstorms. Late-planted and poorly rooted Midwestern corn and soybeans were particularly susceptible to heat stress in areas that have recently dried out, following excessive spring wetness and acute planting delays. Temperatures soared to 90°F or higher east of the Rockies, except in parts of the Appalachians and across the nation’s northern tier. Readings topped 100°F throughout the central and southern High Plains. Elsewhere, dry weather covered large sections of the West and the southern half of the Plains. However, cold fronts delivered some light precipitation to the northernmost Rockies and Pacific Northwest, while showers associated with the monsoon circulation dotted the central and southern Rockies and the Desert Southwest.
South: The remnants of Hurricane Barry continued to produce heavy rain early in the drought-monitoring period in Arkansas and environs. On July 16, daily-record rainfall amounts reached 4.09 inches in Pine Bluff, Arkansas, and 2.28 inches in Memphis. From July 14-16, Pine Bluff received 7.02 inches. Other July 14-16 totals included 5.35 inches in Greenwood, Mississippi, and 5.12 inches in Memphis. Storm totals topped 10 inches in parts of Arkansas and Louisiana. A state 24-hour rainfall record was established in Arkansas, where 16.17 inches fell at Dierks, in Howard County, on July 15-16. Arkansas’ previous record of 14.06 inches had been established on Dec. 3, 1982, at a weather station near Big Fork, in Polk County. An Arkansas state record was also broken for rainfall received during a tropical event; the 16.59-inch sum in Dierks eclipsed the previous standard of 13.91 inches set in Portland, Ashley County, during Tropical Storm Allison from June 28 – July 2, 1989. Outside of Barry’s sphere of influence, slight expansion of abnormal dryness (D0) was noted in parts of Oklahoma and Texas, where very hot weather prevailed until recently. Dalhart tallied a trio of daily-record highs (105, 108, and 107°F) from July 18-20. Elsewhere, moderate drought (D1) further expanded in portions of southern Texas. During the week ending July 21, topsoil moisture rated very short to short as reported by USDA increased from 21 to 43% in Oklahoma and from 42 to 55% in Texas.
Looking Ahead: Showers and thunderstorms will linger for the next few days in the Deep South, primarily across Florida and along the Gulf Coast. Meanwhile, a pair of slow-moving cold fronts crossing the northern U.S. will entrain moisture from the monsoon circulation, leading to spotty showers from the Southwest to the northern Plains and upper Midwest. Dry weather and near- or below-normal temperatures will prevail between the two primary areas of showery weather. Elsewhere, hot weather will dominate the Intermountain West.
The NWS 6- to 10-day outlook for July 30 – Aug. 3 calls for near- or above-normal temperatures nationwide, except for cooler-than-normal conditions in northern Washington and the lower Mississippi Valley. Meanwhile, near- or below-normal rainfall across much of the Plains and Northwest should contrast with wetter-than-normal weather in the Southwest and a broad area covering the mid-South, Ohio and Tennessee Valleys, the lower Great Lakes region, and the Northeast.