United States: Water deficits forecast across the North, surpluses in Texas, Virginia, Carolinas

The 12-month map ending July 2016 for the United States (below) indicates water deficits in the North, through the Great Lakes region and Midwest, and south to the Gulf. Both surpluses and deficits are expected in California. Surpluses are also forecast in: Oklahoma, Texas, Virginia, and the Carolinas, with some areas experiencing both deficits and surpluses.

Oregon's reservoirs were only 44 percent of normal levels at the beginning of November. River flows in Northwest Montana continue to be low and hydrologists say it will take 5 or 6 inches of rain to bring them back to normal.  Earlier in the year the state ordered river closures to protect fish in the scorching temperatures. In contrast, widespread flooding across Texas could cost the state $3 billion in repairs, largely to repair damaged roads and other public infrastructure. In South Carolina, statewide flooding resulted in record-breaking river flows and damages exceeding $1 million.

The 3-month composites (below) for the same 12-month period show the evolving conditions in more detail.

Deficits in the Pacific Northwest may diminish in the upcoming months, and some moderate surpluses may even emerge. However, deficits are expected to return May through July. California and other western states may transition to surpluses which may persist through the remainder of the forecast period. The November through January forecast indicates surpluses in eastern Texas, the Carolinas, and Georgia. From February through April surpluses may persist in California, as noted, throughout the Rockies, down to Oklahoma and Texas, and in Florida.

In contrast, extensive deficits are expected to emerge February through April from the central Gulf Coast region northward through the Great Lakes Region, in Wisconsin and westward. Deficits may expand further May through July to encompass the Pacific Northwest, Midwest, and Northeast, increasing in severity in the Midwest.

Outside the contiguous US, southern Alaska is forecast to transition from deficit to surplus to deficit; Hawaii from surplus to deficit; and Puerto Rico from deficit to surplus.

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