The Central and Eastern States: Another dry week was observed in most areas east of the Mississippi River, prompting significant expansion and intensification of dryness and drought. In addition, most areas from the upper South northward to Canada averaged considerably warmer than normal, increasing topsoil moisture and surface water declines. Spotty moderate to heavy rains (1 to 3 inches) fell during the last couple days on parts of northern Tennessee, central Kentucky, southeastern Indiana, and southeastern Florida. However, other areas recorded less than 0.5 inch for the 7-day period, and most of the Deep South, Appalachians, and Atlantic Seaboard received little or none. As a result, D0 conditions were extended markedly northward toward the southern Great Lakes region and through the eastern Carolinas, mid-Atlantic, and most of the Northeast. Many of these areas have now gone 3 weeks without substantial precipitation.

In the Ohio Valley and most of the Southeast, the areal extents of D1 to D3 conditions increased substantially, except in areas of Tennessee and Kentucky that received locally heavy rains during the last couple of days. In addition, D0 conditions were expanded in some central and western sections of the Southeast, where streamflows have dropped sharply since late April. Farther south, the protracted drought continued in Florida, although moderate to heavy rains prompted an improvement to D1 conditions along the southeastern coast. For the 30 days ending May 8, precipitation totals ranged from 2 to locally 5 inches below normal in the upper Northeast and most of New England, areas from the southern Ohio Valley southwestward to eastern Oklahoma, locations from the central Appalachians and Virginia Piedmont southward through northern Florida, and most sites from Georgia westward through central Mississippi and southeastern Louisiana. In addition, 90-day totals were 4 to 7 inches below normal across the southern reaches of Illinois and Indiana.

The worsening and expanding drought has substantially impacted soil moisture and streamflows throughout the region. As of May 6, the National Agricultural Statistics Service indicated that over half of topsoils were short or very short of moisture across New Jersey and New England, and from Illinois, Indiana, Kentucky, and the Virginias southward through Alabama, Georgia, and Florida. Furthermore, an analysis of the nearly 1000 streamflow reports from the Mid-Atlantic, South-Atlantic-Gulf, Ohio, Tennessee, and Lower Mississippi Basins shows that conditions have quickly deteriorated. Daily record low flows were reported at less than 1% of the aforementioned streamflow reporting sites on March 30, about 3% of sites on April 8, nearly 4% of sites on April 24, and almost 15% of sites on May 8 (the most in almost 14 months). In addition, over 55% of sites were in the lowest 10 percentile of historical flows for May 8, a vast increase above the 9.9% of sites that were similarly low on April 16.

Finally, because shorter-term rainfall deficits have been an increasingly significant contributor to the dryness and drought in the Southeast, the area of primarily-hydrological concerns (D0(W) to D3(W)) was eliminated in favor of straight D0 to D3 designations. However, longer-term precipitation deficits continue to affect parts of the region. Three-year precipitation totals through April 2001 were among the lowest 5% of the historical distribution across southwest Virginia, central and western North Carolina, northwestern South Carolina, all of Georgia, the central and northern Florida Peninsula, central and southeastern Louisiana, and northeast Arkansas.

The Plains: Moderate rains fell on southwest Nebraska during the last 7 days. However, even though this region’s precipitation is above-normal for all time scales going back at least 10 months, a few reservoirs in the region remain at or near record low levels from McCook westward to the Colorado border. Thus, D0(W) is retained for the time being (though slightly reduced in size).

Farther south, deficient precipitation kept D0 to D2 conditions intact across west-central Texas and adjacent New Mexico, and increased short-term rainfall deficits prompted a change from D1(W) to D1 in the southeastern Big Bend region. Moderate to heavy rains (generally 1 to 3 inches) brought an end to the short-lived D0 conditions along the southwestern tier of Texas, but lesser 7-day amounts and drier initial conditions kept D0 and D1 conditions entrenched across far southern Texas.

The West: Precipitation fell at a more seasonable rate, even slightly above normal, during the past 5 weeks or so. However, April precipitation is normally not a big contributor to water supplies in the region, and the main effect was to temporarily stave off further deterioration, which has begun to resume. As of May 1, statewide reservoir volumes were well below normal for the date in Montana, Nevada, Oregon, and Washington, and near normal elsewhere.

It should be noted that the consequences of the ongoing dry winter in the Pacific Northwest would have been even more significant if stored water supplies had not been adequate when the winter precipitation season began in Autumn 2000. As spring progresses into summer, water usage almost always exceeds replenishment throughout the West, and as the already-low water stores in the Pacific Northwest are steadily drawn down, making sufficient water supplies available for all needs will be increasingly challenging.

Hawaii: Weekly rainfall totals were again unimpressive, though some windward areas received more than 1 inch. As a result, D0 to D3 conditions remained as they were on May 1.

Looking Ahead: Events and anomalies that could impact current areas of dryness and drought include (1) Moderate rains May 9 - 14 in the eastern Carolinas and southern sections of Georgia and Alabama; (2) Little or no precipitation May 9 - 14 in most other dry areas, exacerbated by above-normal temperatures in the northeastern quarter of the country and from the High Plains westward; (3) Enhanced chances for surplus precipitation May 15 - 19 in the lower half of the Ohio Valley, the upper Southeast, the southern Appalachians, and the Carolinas and adjacent areas, as well as western Washington and Oregon; (4) Likely below-normal temperatures during the same period from the central Plains eastward as far south as the northern Deep South and central Carolinas; (5) Increased chances of deficient May 15 - 19 precipitation and above-normal temperatures east and south of the Cascades in the Northwest.