Latest Monthly Assessment -
Overall, drought expanded and intensified along much of the southern tier of states over the past 4 weeks, with less dramatic deterioration observed in the Upper Midwest and along the northern tier of states from parts of the Great Lakes region westward to the Pacific Coast. Areas from the central Gulf Coast region westward through the southern Plains in particular saw conditions worsen the most, with 2 to 3 class deteriorations noted over much of the region from eastern Texas eastward across Louisiana and the southernmost reaches of Mississippi and Alabama. On August 8, less than 3 percent of Louisiana was covered by extreme to exceptional drought (D3 or D4). On August 29, that number had risen to over 73 percent. Dry weather there was accompanied by excessive heat for much of the month, which exacerbated the rate of drought intensification. For more than a week, heat indexes topped 120 deg. F were reported at scattered locations each day. In addition, drought expanded in Hawaii over the last four weeks. Less than 7 percent of Hawaii was in drought at the start of August, but drought covered almost 61 percent of the state as the month ended.In contrast, drought generally improved in the middle of the Lower 48, particularly in the central Plains and Middle Mississippi Valley, and drought also eased in parts of the East and in the Desert Southwest. Hurricane Hilary rapidly moved through the Southwest in early August, dropping unprecedented amounts of rain for what is normally a dry month in the region. Almost 3 inches of rain fell on downtown Los Angeles during one day. During all Augusts combined for the prior 146 years, only 6.71 inches fell there.During September, a plume of moisture early in the month is expected to trigger areas of heavy rainfall, bringing some additional drought relief to part of the Southwest. Improvement is also expected in the Southeast from a combination of rains from Hurricane Idalia and disorganized tropical thunderstorm activity farther west toward the Louisiana Bayou. Odds also slightly favor improvement in drought areas of Puerto Rico and the western Virgin Islands.In contrast, drought persistence or intensification is forecast for a vast majority of the drought areas affecting the Lower 48 and Hawaii. Hot and dry weather in the middle of the Lower 48 is expected to bring a broad expansion of drought conditions by the end of the month, with some degree of drought anticipated to cover a large swath from the southern Plains and lower Mississippi Valley northward into the Upper Mississippi Valley and adjacent portions of the northern Great Plains and Great Lakes. Above-normal September precipitation is favored in parts of the Northwest, but this is a climatologically dry time of year there, with only 2 to 5 percent of the annual precipitation typically observed in September. As a result, precipitation totals are expected to be too low to bring any significant drought relief. Drought persistence is also forecast across the eastern Virgin Islands and Hawaii. Some degree of dryness now covers all of the 50th state, and at least a little drought expansion is expected there in some parts of the state, although no specific area seems particularly at risk.
Forecaster: Rich Tinker
Next Monthly Drought Outlook issued: September 30, 2023 at 8:30 AM EDT
Monthly Drought Outlook Discussion