During the past 14-days, above-median rainfall amounts were reported across portions of the Four Corners region, the central and southern Rockies, much of the Great Plains, the middle Mississippi and northern Ohio Valleys, the Great Lakes region, and the interior Northeast. For the upcoming three-month period (July-August-September, or JAS 2015), most climate models favor above-median rainfall from eastern Arizona to west Texas, in connection with the seasonal Summer Monsoon. A one-category improvement is favored in this region. With El Nino now established across the tropical Pacific, there are enhanced chances of an active eastern Pacific hurricane season. Moisture from tropical systems may reach the Southwest CONUS, especially towards the tail end of this seasonal outlook. For most of the remainder of the West, however, drought is expected to persist and/or intensify, as is climatologically the case each summer. Drought is anticipated to develop across the lowlands of western Washington and nearby northwestern Oregon. Small pockets of residual drought across the Great Plains are forecast to be removed during the JAS season, largely due to passing frontal systems, and nocturnal thunderstorm clusters. Residual drought across the Northeast is also ripe for removal, due to the proximity of the summer storm track, and the overall historical tendency for above-median precipitation during the past 10-15 summers. Portions of the Ohio and Tennessee Valley have very recently experienced moderate drought conditions, as designated by the U.S. Drought Monitor. It is anticipated that these areas of increasing rainfall deficits and budding drought will be reversed and eliminated during this Outlook. Across most of the Southeast, above-normal temperatures and below-median precipitation is predicted for all time scales out to 90-days. Drought development is anticipated primarily across the Carolinas, though Georgia is another area that bears careful monitoring. Drought is expected to persist and/or intensify across southern Georgia and adjacent northern Florida, and a one-category improvement is anticipated in southern Florida, even though the traditional rainy season has been off to a slow and unimpressive start. Persistent trade winds are predicted to contribute to sufficient rainfall across the windward (generally, east-facing) slopes of the Hawaiian Islands, while drought development appears more likely across the leeward (generally, west-facing) slopes. During El Nino summers, there is a strong signal for unusual dryness across the Caribbean basin, and a reduction in Atlantic tropical cyclone activity. Therefore, current drought in eastern Puerto Rico is forecast to persist and/or intensify, while drought development is favored for the remainder of the Island.

Forecaster: A. Artusa

Next Seasonal Outlook issued: July 16, 2015 at 8:30 AM EST