Weekly Weather Summary: An unsettled and stormy weather pattern dominated much of the lower 48 States, unfortunately highlighted by a deadly and destructive bout of tornadoes in the Nation’s midsection. The southwest Missouri city of Joplin took a direct hit on May 22 from an EF-5 twister, taking the lives of at least 120 people and injuring at least 750, with numerous people still missing. Two days later, additional tornadoes touched down in Oklahoma and Arkansas, killing at least a dozen people. This stormy weather pattern also dumped moderate to heavy rains across much of the northern half of the U.S. and on much of the Plains, greatly easing drought conditions in the south-central and central Plains. Unfortunately, little or no rain fell along the extreme southern tier of States, from southern Arizona into southern Texas and eastward along the Gulf and southern Atlantic Coasts. Temperatures averaged below-normal in the West, north-central Plains, and Southeast, and above-normal in the southern Plains, upper Midwest, Northeast, and Alaska.
Important Note: The drought depiction for south-central Louisiana has been changed this week to show the areas of drought in the Atchafalaya Basin. As a result, this does not take into account the areas of flooding that were released into this basin from the Morganza Spillway courtesy of the lower Mississippi River flooding. The actual flooded areas have been less extensive and slower to spread than initially forecast; however, the amount of flooding is still significant.
For the latest text information about river levels in the region:
For satellite images (via ASTER on NASA’s Terra satellite) of the Morganza Spillway:
Upper Great Lakes Region: Light rains (0.5 to 1 inch) was reported in northeastern Minnesota and the UP of Michigan, with heavier totals just to the south of the D0 areas. Stream flows and soil moisture indices have shown some improvement recently, but this area still could use a good widespread soaking to eliminate the lingering long-term (12- to 18-months) dryness.
South Atlantic Seaboard and Eastern Gulf Coast States: Little or no rain fell on most of the drought-affected areas (southern and eastern Mississippi, most of Alabama, Georgia, and Florida, and eastern sections of the Carolinas) as moderate to heavy precipitation (1.5 to 4 inches) was recorded just to the north. There was enough rain, however, in central Virginia (0.75 to 1.25 inches) to trim away some of the western D0 edge as deficits have gradually been replaced with near-normal or small surpluses during the past 90-days. At Norfolk, VA, and Elizabeth City, NC, however, 90-day deficiencies were 4.08 and 3.64 inches, respectively, and D1(A) remained. Similar deficits existed on the Delmarva Peninsula of Maryland as D1 was added, while D1 was removed just to the south on Virginia’s Delmarva Peninsula as 2 inches of rain fell earlier in the week. Farther south, light rains (0.2 to 0.7 inches) maintained conditions in the central Carolinas, but an H Impact Line was added to delineate adequate short-term conditions from longer-term shortages in south-central North Carolina and north-central South Carolina.