Midwest Weekly Highlights - February 1-7, 2011
Blizzard Conditions Spread Across the Middle of the Region
A severe winter storm moved across the region during the first three days of February. The storm affected much of the country, from New Mexico to New England, with an estimated 100 million people in 30 states impacted. Insured damages have been tentatively estimated near a billion dollars. The storm was first felt in the Midwest in Missouri and Iowa on January 31st
(Figure 1) and it moved to the east northeast, affecting Chicago and Milwaukee on it way into Michigan. Snow totals for the storm exceeded a foot over a large swath (Figure 2) with totals nearing two feet in northern Illinois. To the south, sleet and freezing rain made for treacherous travel conditions despite the lower snowfall totals. High winds dropped wind chill values and caused blowing snow. Behind the system, temperatures dropped below zero
(Figure 3) as far south as southern Missouri, central Illinois, and northern Indiana. Some stations in Missouri recorded three straight days with minimum temperatures below zero.
Heavy Snow, Sleet, and Freezing Rain
To the northwest of the track of the surface low pressure system, heavy snow fell. Totals over a foot stretched across the region from southwest Missouri to the thumb of Michigan (Figure 4). East winds across Lake Michigan enhanced the snow falling in northeast Illinois and southeast Wisconsin where totals neared two feet. Thunderstorms were reported in northern Illinois on the evening of February 1st when all the precipitation was falling as snow. Nearer to the track of the low, some of the precipitation fell as sleet or freezing rain. Ice accumulated from central Illinois to Ohio. By the end of the week, snow totals in Chicago (Cook County) and Rockford, Illinois (Winnebago County) topped 50" for the season, a record 4th straight season to exceed their normal seasonal snow total by a foot.
Precipitation was two to five times normal along the path of the storm while below normal totals were recorded in the north and southeast reaches of the Midwest (Figure 5). Numerous daily records were set for precipitation (over 200 records) and snowfall (over 500 records) especially in Missouri and Illinois. Many snowfall totals also set records for any date in February (119) or any date in the year (61).
Snow covered the northern two-thirds of the region by the end of the week (Figure 6). Snow on the ground in Minnesota, western Wisconsin, and Iowa was holding 3 to 5 inches of water raising concerns about the possibility of severe spring flooding on the Red River, Mississippi River, and many smaller rivers in the area. Spring flooding conditions will depend greatly on the both when and how quickly the snow melts but the water held in the snow pack significantly increases the likelihood of flooding, and severe flooding. Flooding concerns lessen further to the east and south where longer term dry conditions have been recorded (Figure 7).
Temperatures Vary Across Region
There was a wide range of temperature departures for the first week of February. Southwest Missouri recorded temperatures as low as 15°F below normal while eastern Kentucky, southeast Ohio, and the upper Midwest where above normal (Figure 8). A few dozen daily temperature records were set, mostly record lows.
Schools, Businesses, and Entertainment Shut Down for Storm
Hundreds of closings were caused by the winter storm. Closings included schools, businesses, and even professional sporting events such as the NHL game in St. Louis on February 1st. Closings spread east across the region on the 1st through the 3rd. School closings affected not only elementary and high schools but even some colleges and universities in the area.
Winds in excess of 50 miles per hour were reported in several states. In Iowa and Illinois, the winds caused low wind chill temperatures and blowing snow. Wrigley Field in Chicago
(Cook County) suffered minor damage, closing city sidewalks and streets in the vicinity. As far east as Ohio
(Warren County), wind blew down utility poles and power lines, closing some state highways. A semi truck crashed from I-64 into Slate Creek (Bath County, Kentucky) drowning the driver. Officials believe the truck was blown off the overpass by high winds on February 2nd.