February - April 2010

Outlook Graphic: GIF   PDF 

Latest Seasonal Assessment - From mid-January through April 2010, the drought affecting California, Nevada, Arizona, and adjacent areas should continue to improve. Outlooks for late January and the February-April period call for enhanced chances of above-normal precipitation, except along the northernmost tiers of California and Nevada as well as adjacent southern Oregon, where more limited improvement is expected. Farther north, drought is forecast to persist in central Washington and in areas near the Montana/Idaho border and should expand to cover the area between these two regions. Although odds favor a wet end to January in this region, drier than normal weather should prevail from February through April, consistent with conditions favored during El Niño episodes. Farther east, some improvement can be expected in the recently-identified drought along and near the Idaho/Wyoming border, and in the protracted hydrologic drought affecting parts of the western Great Lakes region. Elsewhere, most signs point to continued recovery for the residual drought areas in southern Texas, but existing short-term precipitation shortfalls and expected below-normal February - April precipitation should allow drought to develop in parts of northwestern Ohio by the end of the period. Finally, drought is expected to expand and intensify throughout Hawaii as below-normal rainfall, consistent with El Niño conditions, is expected to continue.

Tools used in the Drought Outlook included the official CPC precipitation outlook for February 2010 and the long lead forecast for February - April 2010, the four-month Palmer drought termination and amelioration probabilities, various medium- and short-range forecasts and models such as the 6-10 day and 8-14 day forecasts, the soil moisture tools based on the GFS model and the Constructed Analogue on Soil (CAS) moisture, the Climate Forecast System (CFS) seasonal precipitation forecasts, El Niño precipitation and temperature composites for February - April 2010, climatology, and initial conditions.

Moderate to severe drought continues in northwest Wisconsin. Medium-range forecasts call for enhanced chances of above-normal precipitation in late January and early February, with longer-range forecasts non-committal. Based on the wetness anticipated in the medium range period, and the typical snowmelt and increased precipitation that occurs as spring progresses, some limited improvement appears on tap for the region by the end of April.
Forecast confidence for Wisconsin is moderate.

Continued relief for the residual long-term drought areas in parts of southern Texas appears likely through the late winter and early spring. Short- and medium-range forecasts call for near-normal to below-normal precipitation, but the latest monthly and seasonal forecasts continue to indicate relatively high probabilities for wetter than median conditions during February - April. This is consistent with typical conditions for the region during El Niño.
Forecast confidence for Texas is high.

Wetter than normal conditions are forecast on all time scales relevant to this forecast across all but the northernmost tier of the drought covering much of California, Nevada, Arizona, and adjacent areas. A series of storms has recently brought heavy precipitation to part of the area, and storminess should continue periodically through early February. The 3-month outlook favors continuing above-normal precipitation for all but the northernmost tier of this region, where improvement is forecast to be less robust.
Forecast confidence for the Southwest, Great Basin, California, and southern Oregon is high.

Ongoing drought conditions should continue across central Washington and along the northern Idaho/Montana border, and are forecast to expand through the area between these two regions in eastern Washington and much of the Idaho Panhandle. The February - April period calls for enhanced odds of below-normal precipitation across the region, which is consistent with typically-observed conditions during El Niño events. Forecasts for above-normal precipitation during the remainder of January and early February, however, temper the confidence of this forecast.
Forecast confidence for Washington, northern Idaho, and western Montana is low.

Drought recently developed in areas along and near the Idaho/Wyoming border, extending into small parts of southwestern Montana and northern Utah. Above-normal precipitation is favored in these regions through the remainder of January and early February while longer-term precipitation amounts are uncertain. Some improvement is forecast based on the short- and medium-range forecasts, but February - April precipitation will be critical in determining whether or not mountain snowpack ends up deficient before snowmelt recharge begins in earnest, and the uncertain forecast for this period leads to a low confidence drought forecast.
Forecast confidence for southeastern Idaho, western Wyoming, and adjacent Montana and Utah is low.

Over part of northwestern Ohio, short-term precipitation deficits have been observed, and although near- or above-normal precipitation is favored through early February, the February monthly and February - April seasonal forecasts both call for enhanced chances of below-normal precipitation. These longer-term forecasts are consistent with conditions typically observed during El Niño events in the region. Because of early-period forecasts, any drought development in northwestern Ohio would likely take place during the last 2.5 months of this forecast period.
Forecast confidence for Ohio is low.

As is consistent with an ongoing El Niño, Hawaii is expected to receive below-median precipitation during this period. These dry conditions will likely exacerbate ongoing areas of severe to extreme drought over Hawaii and also provide support for drought development over the remainder of the island chain.
Forecast confidence for Hawaii is high.