South: Intensifying dryness from northeastern Texas to the central Gulf Coast contrasted with heavy rain and much-needed drought relief in western portions of the region.
Despite isolated downpours (locally more than 4 inches) providing localized relief from Abnormal Dryness (D0) in coastal portions of Louisiana and Mississippi, most locales reported sub-par rainfall for the week. Over the past 30 days, many of the newly-expanded D0 areas have reported less than 25 percent-of-normal rainfall (locally less than 10 percent) with deficits over the same period totaling 2.5 to 5 inches.
In northeastern Texas, locales from Dallas eastward have reported similar shortfalls over the past 30 days, with 60-day precipitation totaling less than 70 percent of normal. Meanwhile, 7-day rainfall totaled 1 to 3 inches (locally more) from central Texas northward into western Oklahoma, resulting in widespread reductions to this week’s drought intensity and coverage.
Notable amounts included: 4.92 inches near Bertram, north of Austin; 4.76 inches in Crowell, west of Wichita Falls; and 3.35 inches in Willow, Okla., north of Altus. The rain was not only heavy, but also frequent. Childress saw measurable rainfall for 8 consecutive days from May 13 – 20; this ties the all-time record dating back to 1948.
Despite the beneficial rain, Severe (D2) to Exceptional (D4) Drought persisted over much of the southern High Plains, where 6-month precipitation has totaled locally less than 25 percent of normal.
An active pattern will continue, with two significant areas of wet weather over the next 5 days. Forecast data continues to show a tropical or subtropical system developing over the eastern Gulf of Mexico and lifting slowly northward over the Memorial Day holiday weekend; if this were to verify, the potential exists for another round of heavy to excessive rain (2-6 inches, possibly more) over the lower Southeast.
Meanwhile, a pair of slow-moving storms system will produce moderate to heavy rain (1-4 inches) from the northern Rockies eastward across northern portions of the Plains and Upper Midwest. A trailing cold front will trigger showers over the western Corn Belt and Mississippi Valley. Despite the continuation of a generally active weather pattern, the Southwest will remain unfavorably dry.
The NWS 6- to 10-day outlook for May 29 – June 2 calls for below-normal rainfall over the Northwest and from Texas and the southern High Plains into the Great Lakes and New England. In contrast, wetter-than-normal conditions are expected from the northern Great Basin into northern portions of the Rockies and Great Plains, with a second higher-likelihood area of above-normal rainfall over the southeastern quarter of the nation. Abnormal warmth is expected over most of the nation save for near-normal temperatures in the aforementioned rainy and cloudy Southeast.