Latest Seasonal Assessment -
During the past month, enhanced rainfall along a persistent mean frontal boundary draped along the eastern US resulted in substantial drought relief across the Southeast and mid-Atlantic states, although patches of drought remained, particularly across the coastal plain of Georgia and South Carolina. In contrast, outside of a swath of heavy precipitation from a late season snowstorm along the Iowa/Minnesota border through southern Wisconsin, precipitation was well below average across the northern Plains and western Corn Belt, resulting in an eastward expansion of abnormal dryness (D0) conditions. Temperatures in this region remained well below average for the time of year, which helped to slow the advancement of more severe drought conditions. As spring transitions to summer, however, these dry incipient conditions leave this region vulnerable to flash drought development should an extended period of hot, dry weather occur. Across the West, drought conditions persisted or expanded slightly under a general regime of above-normal temperatures and subnormal precipitation. During the next two weeks, a highly active pattern is anticipated across almost the entire contiguous U.S. outside of the climatologically arid Southwest, with the heaviest precipitation over the central and northern Plains, the Southeast, Mid-Atlantic, and southern New England. The wet conditions favor further drought reductions across the East, and given that both subseasonal and seasonal-scale forecasts favor continued wetness through the JJA period, complete drought removal is forecast by the end of the period. The wet short term forecasts coupled with climatology favor some relief of the most extreme drought conditions across the central Plains, but the absence of a clear wet signal in this region makes full amelioration of the entrenched long-term drought conditions unlikely. Over southern Texas, a somewhat drier pattern is anticipated over the next two weeks, and climatological precipitation drops off during the summer. Therefore, drought persistence and expansion is favored. Over the West, seasonal guidance favors below-median precipitation for the Northwest, favoring persistence and slow expansion given the drier climatology. Despite the anticipated onset of monsoon thunderstorms over the Southwest during mid-summer, dry initial conditions including a lack of snow cover, a potential for worsening drought in the short term, and the absence of a clear wet signal in the seasonal guidance makes persistence more likely at any given location than improvement.
No drought conditions currently exist across Alaska, Hawaii, and Puerto Rico, and drought development is unlikely in these regions over the next three months.
Forecaster: Adam Allgood
Next Seasonal Outlook issued: June 21, 2018 at 8:30 AM EDT
Seasonal Drought Outlook Discussion