In contrast, subnormal rainfall continued across the eastern Gulf and southern Atlantic States. The last week that this region received widespread, soaking precipitation was in late March and early April, and conditions continued to deteriorate. USGS stream flows at 1-, 7-, 14-, and 28-days continued to drop, and many in southern sections of Mississippi and Alabama, most of Georgia, northern Florida, and parts of the Carolinas were in the lower tenth percentile as of May 24. According to USDA/NASS state reports, topsoil moisture rated short or very short increased this week to 82, 75,54, 48, and 47 percent, in Georgia, Florida, Mississippi, South Carolina, and Alabama, respectively. Similarly, pasture and range lands rated poor or very poor rose to 41 and 47 percent in Florida and Georgia. In southern Florida, the combination of short-term dryness (90-days: 25 to 50 percent of normal rainfall) and long-term deficits (since October 1: Miami 8.83 inches; West Palm Beach 21.39 inches; Ft. Lauderdale 20.97 inches; Naples 11.52 inches) have greatly lowered river and lake levels and some wells. Lake Okeechobee stood at 10.41 feet (normal 13.19 feet) on May 22, below the critical line for water shortages. Accordingly, D0 through D3 was incrementally increased northward in Mississippi, Alabama, and into western Georgia and northern Florida, and in extreme southern Florida (D3 in Monroe and Dade counties) in response to the growing short-term deficiencies.
Lower Mississippi Valley: As mentioned in the above “Important Note”, the opening of the Morganza Spillway on May 15 (last opened in 1973) had projected to flood much of the Atchafalaya River basin in south-central Louisiana by now. But due to the basin’s hydrological complexity and uncertainty, especially in the southern end, the rate and extent of flooding was less than initially forecast. Where it has flooded, however, the flooding is still significant. In contrast, where the flood waters had not yet reached, U.S. Forestry officials reported that many marshes were dry with fish kills from lack of oxygen in the remaining pools of water in coastal parishes of southwest and south Louisiana. Therefore, due to the severity of the ongoing drought and the lack of a recent image of actual flooded land, the area of drought depiction was returned to all of Louisiana. And of course, the flooded regions of the Atchafalaya basin (not depicted) would be drought free.
Elsewhere across southern Louisiana, little or no rain fell once again. Light rains (0.5 to 1 inch) occurred in northeastern Louisiana and southeastern Arkansas, while 1.5 to 2.5 inches fell on western Louisiana and eastern Texas. Unfortunately, additional heavy rains (2 to 8 inches) inundated the already-saturated upper Delta region (western and northern Arkansas, southern Missouri), adding more water into the swollen main stems of the Mississippi River. The rainfall did provide some basis for slight drought reduction in eastern Texas, western Louisiana, and southern Arkansas as a 1-category improvement was made to areas with weekly totals of 2 inches or more. However, large long-term (12-months) deficits (15 to 20 inches) remained in portions of the lower Mississippi River Valley, and were between 25 to 35 inches at 18-months.