Midwest Weekly Highlights - January 25-31, 2011

---

An Uneventful Week

Temperatures recovered to near to above normal levels this week, and precipitation was mostly limited to snow associated with weather systems moving through the upper Midwest. However, as the month drew to a close a major winter storm gathering strength in the southern Plains was taking aim on the Midwest.

In sharp contrast to the rest of the month, temperatures this week were 5°F to 9°F above normal in the northwestern portion of the region (Figure 1). Temperatures across southern Missouri eastward through Kentucky were from 1°F to 4°F above normal. However, in between these two areas temperatures were near normal to 2°F below normal. There were just a handful of temperature records during the week.

There was little change in the U.S. Drought Monitor status at the beginning of this week (Figure 2), and dry weather for most of the Midwest meant that little improvement was likely (Figure 3). The exception was an area from western Minnesota eastward across northern Wisconsin, and in eastern Kentucky. Several fast-moving weather systems in the upper Midwest brought snow to western Minnesota, and precipitation there was in excess of 200 percent of normal. In addition to western Minnesota, snow was also well above normal across northern Wisconsin, eastern Michigan, and the Ohio Valley (Figure 4). At the end of the week, however, the southern edge of the snow cover in the Midwest had retreated northward leaving most of the southern half of the region with less than two inches on the ground (Figure 5). A storm the first two days of this week brought from two to six inches of snow to Kentucky (Figure 6). There was little sign of it by the end of the week as temperatures warmed to as high as the low to mid 60s over southern Missouri into Kentucky (Figure 7).
 

A Storm Waiting in the Wings

On January 31st a storm system was beginning to organize in the the southern Plains (Figure 8). Warm, moist air aloft overrunning much colder air near the surface resulted in an area of freezing rain from Missouri eastward into Kentucky which caused travel problems in these areas. Portions of Interstate 70 in Missouri were closed for a time due to the ice. The storm was forecast to intensify and then move thought the Midwest on February 1-2. By late afternoon on January 31st winter weather advisories and warnings were in effect for much of the central U.S. Winter Storm Warnings extended from Texas to Vermont, and Blizzard Warnings were in effect for portions of Iowa and northern Illinois (Figure 9)

-SDH-