April - June 2004

Latest Seasonal Assessment - In the West, the drought forecast calls for improvement in the drought situation across northern Nevada, southeastern Oregon, southern Idaho and northwestern Utah. Winter storms have resulted in near to above average snow pack in the mountains. This should result in higher stream flows and increased soil moisture. Further south, some improvement is expected across central Nevada, most of Utah, western Colorado, western Montana and northern Wyoming. However, the drought is expected to remain ongoing through the spring. Snow pack across these areas is near to slightly below normal. However, the mountain snow pack is better this year than last year across most of the area. Therefore, there is a slow positive trend in the drought situation. There is a slight tilt of the odds in favor of a cooler than normal spring across much of Wyoming and Montana. This would be favorable for pastures and would reduce evaporation. In the Southwest, the drought is expected to persist. Precipitation tends to be light during the spring across most of the southwestern U.S. As a result, moisture deficits will remain in place throughout the period. In the High Plains of eastern New Mexico and southeastern Colorado, moisture deficits from previous seasons are expected to remain and drought is forecast to persist. Further north, some improvement is expected across northeastern Colorado, northwestern Kansas, western Nebraska and southwestern South Dakota. Elsewhere, snow melt and spring rainfall are expected to result in improvement across the northern High Plains, the eastern Dakotas, Minnesota and Wisconsin. In the Southeast a recent drying trend has raised concerns about drought development. The area will continue to be monitored, and may be included in subsequent releases of the U.S. Drought Outlook.

Tools used in the Drought Outlook included the official CPC long-lead precipitation outlook for April-June, the Palmer Drought Index Probability Projections for June, various medium and short-range forecasts and models such as the 6-10 day and 8-14 day forecasts, and the soil moisture tools based on the GFS model and the Constucted Analogues for the season.

In the West, the drought forecast calls for improvement in the drought situation across northern Nevada, southeastern Oregon, southern Idaho and northwestern Utah. Winter storms have resulted in near to above average snow pack in the mountains. Snow water equivalents ranged from 101 to 121 percent of normal as of March 15. Furthermore, there are indications that precipitation during the April through June period may be above normal across much of Oregon and parts of southern Idaho. This should result in higher stream flows and increased soil moisture. However, warm temperatures over the next few weeks may erode the snow pack during late March. Moisture deficits left over from past years have resulted in dry soils. Therefore, some of the runoff may be lost to these dry soils before reaching the rivers and reservoirs. Although improvement is expected, lingering moisture deficits are also possible. Further south, some improvement is expected across central Nevada, most of Utah, western Colorado, western Montana and northern Wyoming. However, the drought is expected to remain ongoing through the spring. Snow pack across these areas is near to slightly below normal. Snow water equivalents ranged from 75 to 100 percent of normal as of March 15. Near to below normal spring and summer stream flows are expected according to the latest USDA NRCS stream flow forecast. However, the mountain snow pack is better this year than last year across most of the area. Therefore, there is a slow positive trend in the drought situation. There is a slight tilt of the odds in favor of a cooler than normal spring across much of Wyoming and Montana. This would be favorable for pastures and would reduce evaporation. In the Southwest, the drought is expected to persist. Below normal snow pack across the mountains of Arizona and New Mexico should result in below normal spring and summer stream flow. Furthermore, precipitation tends to be light during the spring across most of the Southwest. As a result, moisture deficits will remain in place throughout the period. The next chance for significant precipitation climatologically will be in July and August with the onset of the summer monsoon.

In the High Plains of eastern New Mexico and southeastern Colorado, moisture deficits from previous seasons are expected to remain. There are indications that the April through June period will be drier than normal across this area. Since this is the time of year when the wet season begins, moisture deficits may increase across the area. Further north, some improvement is expected across northeastern Colorado, northwestern Kansas, western Nebraska and southwestern South Dakota. Precipitation normals increase during May and June across much of this area and is one of the best times of the year for moisture recharge. Furthermore, there are some indications that the spring will be cooler than normal across parts of the region. However, long term moisture deficits left over from previous years will likely persist. 3 year precipitation deficits of 6 to 15 inches exist across much of the central High Plains. Across the northern High Plains, improvement is expected across the region as the wet season gets underway.

Elsewhere, snow melt and spring rainfall are expected to result in improvement across the eastern Dakotas, Minnesota and Wisconsin. In the Southeast a recent drying trend has raised concerns about drought development. There are some indications that the spring may be dry across Florida, Georgia and Alabama. However, the signal was not strong enough to warrant a "drought development likely" polygon on the graphic. The area will continue to be monitored, and may be included in subsequent releases of the U.S. Drought Outlook.