United States: Exceptional deficits to continue in SW states

18 April 2025

THE BIG PICTURE

The forecast for the 12-month period ending in December 2025 indicates that exceptional deficits will diminish in portions of the Southwest, but persist in several states within the region. Exceptional deficits are also expected in pockets of Texas and the Midwest, as well as the Carolinas. Alaska will observe continued surpluses.

Severe to exceptional deficits are expected in:

Nevada, throughout south-central regions of the state. These deficits also appear in pockets throughout Utah and Arizona, with the most concentrated anomalies occurring in areas along shared borders of the two states.
Central Texas, with exceptional deficits appearing near the Concho River.
Regions along the shared border of southern Nebraska and northern Kansas, near the city of Norton.
Minnesota, throughout regions near the Leech Lake Reservation.
Eastern coastal regions of North Carolina, continuing south along the coast of Carolina Beach, into eastern coastal South Carolina. Further north, extreme to exceptional deficits are expected in south-central Pennsylvania.

Severe to exceptional surpluses are anticipated in:

Oregon, spreading from central to southeastern regions of the state, continuing south into northeastern California.
Pockets along southern coastal regions of Florida.
Alaska, with the most intense anomalies appearing in the North Slope Borough and Yukon-Koyukuk Census Area.

The 3-month maps (below) show the evolving conditions in more detail.

FORECAST BREAKDOWN
The forecast through June 2025 indicates that exceptional deficits will persist throughout much of the Southwest, with the highest concentrations of anomalies occurring in southern California, southern Nevada, southwestern New Mexico, and southeastern Utah. Exceptional deficits are also expected in central and northern Texas, northern Minnesota, and southern portions of North Carolina. Moderate to severe surpluses will persist in central to southeastern Oregon, east-central Washington, southern Florida, and northern to central Alaska.

From July through September 2025, exceptional deficits are expected to diminish in the southwest, though pockets are expected to remain in northeastern New Mexico, southeastern Utah, and in areas of California near San Luis Obispo County. Exceptional deficits will remain in regions between the borders of southern Nebraska and northern Kansas, as well as throughout northern Minnesota. Moderate to severe surpluses will continue in southeastern Oregon and central and northern Alaska.

The forecast for the final months – October through December 2025 – anticipates moderate to severe surpluses in regions of southeastern Oregon, as well as isolated pockets across Alaska. Severe to extreme deficit is anticipated in coastal regions of the Northeast, with the most intense anomalies occurring in Massachusetts. These deficits continue further south, becoming moderate deficits that continue into the Carolinas and northeastern Florida. Coastal regions of North and South Carolina may experience severe deficits.

Please note that WSIM forecast skill declines with longer lead times.

IMPACTS
Officials have warned of a dry summer in southern Nevada as winter snowpack levels measure below-average in the Upper Colorado Basin. These shortfalls could potentially revert recent gains in water levels at major reservoirs such as Lake Mead and Lake Powell, which are already critically low. Snowpack in the basin are reportedly only 89% of the historical median, while streamflow into Lake Powell is projected at 74% of its normal level. Southern Nevada’s local snowpack was even worse, at only 30% of the historical median.

In Utah, the San Rafael River continues to dry up as droughts threaten local water levels and native fish species, such as the flannelmouth sucker, bluehead sucker, and roundtail chub. These fish species have lost up to 85% of their historical range and are considered vital indicators of ecosystem health. Efforts to restore the region’s environmental health have started, but are stifled by limited funding, water rights laws, and the long-term effects of drought and climate change.

Though central and southern Texas recently saw some rainfall, the regions remain in a severe drought as lake levels reportedly at record lows. Canyon Lake has hit record low levels for ten consecutive days, at only 47.1% capacity – over 30 feet below. Medina Lake is in an even worse state, with levels 94 below capacity – just 2.2% full. Both lakes are dropping about an inch every three days.No rain is expected in the short term due to persistent high pressure, although some forecasts anticipate potential thunderstorms around April 16–20.

Regions across the South and Midwest saw devastating floods in early April, which killed at least 20 people. Rivers in Kentucky reached near-record highs on April 7th, which submerged neighborhoods and forced citizens of Frankfort and Falmouth to evacuate. Tennessee, Arkansas, and Indiana also saw destructive flooding which damaged infrastructure, shut down roads, and cut off water access for thousands.

NOTE ON ADMINISTRATIVE BOUNDARIES
There are numerous regions around the world where country borders are contested. ISciences depicts country boundaries on these maps solely to provide some geographic context. The boundaries are nominal, not legal, descriptions of each entity. The use of these boundaries does not imply any judgement on the legal status of any territory, or any endorsement or acceptance of disputed boundaries on the part of ISciences or our data providers.

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