Latest Seasonal Assessment -
During the past 30 days, a persistent ridge fueled multiple heatwaves and wildfires, and led to substantial drought expansion across the Northwest. Monsoon precipitation eased drought conditions across the Four Corners states, although drought continued to expand across the northern Great Basin. Locally heavy precipitation overspread much of the south-central Plains, bringing drought relief particularly to western Kansas, Oklahoma, southeastern Colorado, and northern Texas. In contrast, persistent dryness caused substantial drought expansion and intensification across central Texas, southern Oklahoma, and the middle Mississippi Valley. Dry summer conditions also promoted slow expansion of drought across the upper Mississippi Valley and northern Plains, although the areal extent of drought coverage was small. Further east, a persistent plume of tropical moisture eased drought conditions across much of the Northeast while bringing record accumulations and widespread flooding to the mid-Atlantic. Short term drought continued to linger, however, across parts of the Great Lakes states, northern New York, and northern New England, with most of the heavier precipitation falling to the south and east.
Over the next few months, flash drought becomes less of a concern as the sun angle decreases and crop moisture demands lessen. In the short term, a slow moving area of low pressure is currently and expected to continue producing widespread heavy rainfall across the central Plains and Midwest through the eastern Great Lakes and northern New England, with accumulations of 5 to 7 inches possible across the mid-Mississippi Valley. This wet pattern is favored to continue through the end of August, with equal chances for below-, near-, and above-normal precipitation following through the Autumn months. Near to below-normal temperatures are also favored through the close of the meteorological summer across the central U.S. The rainfall will help to ease drought conditions from North Texas through the lower Great Lakes and New England. Generally drier conditions are favored away from the frontal boundary for central and southern Texas and the upper Midwest and northern Plains, which favors drought persistence in these locations. Slow drought expansion is possible in northern Minnesota and North Dakota. The latter part of the summer monsoon season is anticipated to be robust across the Southwest, leading to further drought reduction across the Four Corners states. In contrast, a forecast for persistently hot and dry conditions will exacerbate drought impacts across the Northwest, which may lead to further development across Washington and Oregon. Persistence is favored for moderate drought across Alaska's southern Panhandle. A regime favoring above-normal precipitation should ease the recent advancement of drought across Hawaii, but substantial relief is not likely until the main wet season begins beyond the forecast period. Developing El Niño conditions favor widespread suppressed convection across the Caribbean, leading to enhanced chances for drought development across already dry portions of Puerto Rico.
Forecaster: Adam Allgood
Next Seasonal Outlook issued: September 20, 2018, at 8:30 AM EDT
Seasonal Drought Outlook Discussion