The Big Picture
The 12-month map ending November 2016 (below) depicts the widespread moderate to exceptional deficits forecast for Montana, Wyoming, North Dakota, Minnesota, Michigan, and much of the Mississippi and Ohio Valleys. Surpluses are forecast for the Southern Plains and southern Florida. Both deficits and surpluses are expected in the Pacific Northwest, Virginia, North Carolina, South Carolina, northern Georgia, and eastern Alabama.

Impacts
Following record rainfall Florida's water managers began dumping water out of Lake Okeechobee to relieve pressure on its dike, pushing an inky sludge into both the Atlantic Ocean and the Gulf of Mexico. Faced with an aging flood control system the move has become routine over the years, prompting protests from commercial and recreational fisherman who fear widespread fish kills from the lake's industrial run-off. The state's tourism industry is also likely to be affected. Concern is mounting over prospects for the US Plains region's hard red winter wheat crop, the largest US wheat class, as its need for moisture peaks during what is becoming a dry spring. Alaska’s iconic, 1,000-mile sled dog race - the Iditarod - had to import seven train cars of snow to pave the ceremonial send-off route.

Forecast Breakdown
The 12-month map does not reveal the drama of the evolving conditions as well as the 3-month maps (below) for the same time period. Note the contrast between conditions observed in the last three months (Dec 2015-Feb 2016) and those predicted for March through May. Oranges and reds color much of the US east of the Mississippi River in the March through May map indicating a forecast of widespread and severe water deficits. Southern Florida stands out as the only area in the eastern half of the country where water surpluses – exceptional water surpluses – are expected.

From June through August, water deficits are forecast to emerge across the North, in the Central Plains, Northern Great Plains, and in the West. Extreme to exceptional deficits pop out in pockets of the Pacific Northwest, northwest Nevada, and much of western California. Deficits also trace paths along the Missouri, Yellowstone, North Platte, Colorado, Mississippi, and Ohio Rivers. In contrast flooding is forecast along the Rio Grande River through New Mexico and Texas, and along the Canadian River as it cuts through the Texas Panhandle into Oklahoma.

Though the severity will decrease, widespread deficits remain in the forecast through November, with moderate to severe (5-20 year return period) deficits blanketing an area from Minnesota southward to the Gulf of Mexico and eastward to the Atlantic. Deficits will also persist in the Pacific Northwest, Idaho, Montana, Wyoming, and along the Missouri and Yellowstone Rivers. Farther south, water surpluses reaching flood conditions in some areas are forecast for rivers in Arizona, New Mexico, southern Colorado, and parts of Texas.

Outside the contiguous US, Alaska is forecast to remain basically in a pattern of deficits in the north and east, and surpluses in the south through May. Moderate surpluses are in the forecast for Hawaii during the latter months of the forecast period. Water surpluses are forecast for Puerto Rico from April through August.

(It should be noted that forecast skill declines with longer lead times.)