November 2005 - January 2006

Latest Seasonal Assessment - Some improvement is on tap for most of the drought area that extends from the Pacific Northwest through parts of the northern Rockies, the Plains states, and the Midwest. The greatest chance for improvement lies across western portions of Washington and Oregon. Odds also favor improvement for the lingering drought in Wisconsin and parts of Michigan, although breaking the serious drought in northern Illinois and southern Iowa is less likely, and only limited improvement is expected in this area. In the Southwest, despite some heavy rains in mid-October, drought should persist, as the latest official seasonal outlook shows the odds tilting toward below-normal rainfall and above-normal temperatures. Over the southern Plains, despite unfavorable short-term prospects for relief, the seasonal precipitation outlook indicates a tilt toward wetness in eastern Texas and eastern Oklahoma, resulting in a forecast of some improvement. To the south, there are fewer indications for improvement, and the drought affecting South Texas is expected to persist. Farther east, drought affecting Kentucky and southern Ohio should see some improvement, but the hydrological drought affecting parts of North Carolina may very well persist into winter.

Tools used in the Drought Outlook included the official CPC long-lead precipitation outlook for November-January, the drought termination and amelioration probabilities for January, 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 Constructed Analogues for the season.

This Outlook is a bit more optimistic about drought relief for the Northwest and northern Rockies based on both near-term prospects for precipitation in the first 2 weeks of the period along with improved odds for some drought amelioration in parts of the region based on climatology, as we go into a relatively wet time of the year. As a result, areas shown as persisting in last month’s outlook and the October 6 update have changed to show some improvement. However, to the south, CPC’s latest seasonal outlook indicates a tilt of the odds toward below-normal rainfall and above-normal temperatures for the Southwest, resulting in maintenance of the outlook for persisting drought. Farther east, the CPC long-lead outlook indicating above-normal rainfall during November-January keeps the Texas-Oklahoma drought area in the some-improvement category despite near-term indications of drier conditions. There is little indication for improvement in the short or long term for the South Texas drought, so this area is changed to show persisting drought. In the Midwest, recent rains have ended the drought for northern Wisconsin and northern Michigan, but the drought centered in northern Illinois remains. A deep upper level low over the region during the first days of the outlook period in October is forecast to bring rain to parts of this region, but climatology and some statistical forecast tools, such as the constructed analogs, lean toward little further relief during November-January for Illinois, resulting in keeping the some-improvement label for parts of this area. The CPC Palmer Drought Index probability data for January suggest that climate favors improvement in the northern part of this drought area, so Wisconsin and parts of southern Michigan are shown to improve. With CPC showing equal chances wet or dry for the drought areas in Kentucky and North Carolina during November-January, considerable weight is put on the medium-range outlooks and climatology. Both point to limited improvement for the Kentucky-southern Ohio drought. The outcome for the lingering North Carolina drought is very uncertain, with conflicting signals, but the bias in this Outlook is toward continuing drought given a number of seasonal forecast tools hinting at a dryness trend in the Southeast and the October 18 CPC 2-week soil moisture forecast showing reduced soil moisture. Of course, all bets are off if Hurricane Wilma brings heavy rains into this area. Latest indications are that heavy rains should mainly be confined to the coastal areas east of the drought.