As the wet season nears its end in the West, coincident with the waning El Nino, a return to climatologically dry conditions is favored across the region. Though the final drought-related statistics for California are still being determined, it appears that northern portions of the state fared well this past winter season in such areas as precipitation, snowpack, and reservoir levels. Southern California did not fare as well, despite the presence of one of the strongest El Nino's on record. Late season precipitation was indeed welcome in southern California, but unfortunately, significant moisture deficits remain. Much of the Desert Southwest also missed out on anticipated El-Nino related precipitation this past winter. During the next two weeks, above-median precipitation is favored across portions of California, the Great Basin, and the Southwest. However, the heaviest precipitation is expected to occur outside the ongoing drought areas. For the upcoming May-June-July (MJJ) season, drought persistence is forecast for most areas west of the Continental Divide. For the Great Plains and Middle Mississippi Valley, however, MJJ is climatologically a wet time of year, due to the passage of frontal systems and nocturnal thunderstorm clusters (MCS's). About one-half of the annual precipitation that falls over the lower Plains typically occurs during MJJ, and approximately one-third of the annual precipitation that falls over the High Plains usually occurs in MJJ. Precipitation outlooks out to 90-days in the future also favor a relatively wet pattern. Based on these factors, a one-category improvement in drought conditions is expected across the Great Plains, the eastern foothills of the northern Rockies, and the Middle Mississippi Valley. In the subtropical North Pacific, the climatological trade wind regime has returned to the Hawaiian Islands, after some disruption associated with the El Nino. This pattern change favors heavy precipitation for east- and northeast-facing (windward) slopes, and drought removal. Leeward slopes, situated in the rain shadow areas of high terrain, are favored to experience drought persistence during the MJJ season. At this time, there is no drought in Alaska. Across the Caribbean, the annual return of the Inter-Tropical Convergence Zone (ITCZ) and the Atlantic hurricane season signals a return of the wet season. A one-category improvement in drought conditions is therefore predicted in Puerto Rico.

Forecaster: Anthony Artusa

Next Seasonal Drought Outlook issued: May 19, 2016 at 8:30 AM EDT