February 8-14, 2007
Midwest Weekly Highlights - February 8-14, 2007
Winter Maintains Icy Grip
The entire Midwest remained under the influence of Arctic air this week, and the southern two-thirds of the region dealt with the second major storm of the season at the end of the week.
Temperatures this week ranged from 8°F below normal in southeastern Missouri, extreme southern Kentucky, and north-central lower Michigan, to 18°F below normal in extreme northwestern Minnesota (Figure 1). Temperature departures from 10°F to 14°F below normal extended in a wide band from southwestern Minnesota through Iowa, the northeastern two-thirds of Illinois and Indiana, much of Ohio, and northern Kentucky. The was reflective of the snow cover across the region during most of this period (Figure 2).
Precipitation was well above normal across the southern two-thirds of the Midwest this week, largely as a result of the storm which moved through the region February 12-14. Precipitation reached 200 to 300 percent of normal for the week from southern Missouri east northeastward into Ohio (Figure 3). Actual precipitation amounts (liquid) this week exceeded two inches in the many parts of the storm-affected area (Figure 4), amounts equivalent to the normal precipitation for the entire month of February. Meanwhile, the northern and southern extremes of the region remained very dry. Snow cover over the northern half Minnesota and northern Wisconsin is well below normal (Figure 5). Extreme Drought persists over northern Minnesota, with Moderate to Severe drought occurring across northern Wisconsin and the Michigan UP, as depicted in the February 13 U.S. Drought Monitor (Figure 6). Moderate Drought also was depicted this week in far southern Kentucky.
A Quiet Start...
Although it was very cold, the week started quietly enough with high pressure dominating the region. Some lake-effect snow continued in Michigan, Indiana, and Ohio early in the period, but diminished as the high pressure system pushed southward and winds abated (Figure 7). As the high pressure system continued to move to the Mid-Atlantic coast on February 11, southerly winds briefly brought warmer weather to much of the region. High temperatures reached the freezing mark over many locations in the central part of the Midwest for the first time in a week (Figure 8). Over the deeper snow cover, however, temperatures had a tough time making it out of the upper 20s.
Blizzard!
On the morning of Monday, February 12, a low pressure system was developing over the Texas Panhandle (Figure 9). This storm was forecast to intensify and take aim on the central Midwest. By midnight on February 12, a huge precipitation shield had spread northward through Missouri, Iowa, central Illinois and central Indiana (Figure 10). Rain was falling across southern Missouri, Illinois, Indiana and southward, while a mix of freezing rain and sleet occurred in a transition zone in south-central Illinois and Indiana. Snow fell north of the mixed precipitation. By dawn on February 13 the center of the intensifying low pressure system was located over central Arkansas (Figure 11), and snow was falling from Missouri to New York, while mixed precipitation was falling from the Ohio Valley to the mid-Atlantic coast. Winter Storm Warnings covered an area from the Missouri-Kansas border to northern Maine, and were posted for an area from central Illinois across central Indiana, and into northwestern Ohio (Figure 12).
Snow continued throughout the day on February 13 in Illinois, and into February 14 in Indiana and Ohio. Strong winds of 20 to30 mph with gusts to 40 mph whipped the snow into drifts as large as six feet across central Illinois and the northern half of Indiana. During the height of the storm on February 13 many counties in central Illinois and Indiana pulled plows off of the roads because they could not keep up with the falling and drifting snow. Further south, generally along Interstate 70, several inches of snow accumulated on top of ice from freezing rain the night before. Flights were delayed and cancelled at O'Hare Airport in Chicago, but the airport did remain open. Schools were closed across Illinois, Indiana, and Ohio. Power was disrupted for residents of southern Ohio and Kentucky due to icing on power lines and high winds. Icing from 3/4 to one inch thick was reported in parts of southern Ohio. Across southern Missouri and Illinois, heavy rain resulted in some minor flooding of rivers and streams.
When the storm finally pulled out of the Midwest, a swath of 10 to 15 inches of snow had piled up from central Illinois into Ohio after 24 to 36 consecutive hours of snowfall. In Chicago, Midway Airport recorded 12.0 inches of snow, the most to fall in a February storm in 74 years. many locations in Illinois and Indiana recorded new daily snowfall records for February 13. The heaviest snow amounts were found from eastern Illinois into western and north-central Indiana (Figure 13, NWS-Lincoln, IL).. Amounts generally were in the 12 to 14 inch range, and a cooperative observer in Sidell, IL (Vermilion County) reported 17.0 inches of snow. There was a range of snow amounts reported, indicative of the difficulty in measuring snow in the extremely windy conditions. Fourteen to 16 inches of snow accumulated in a band across north-central Indiana into northwestern Ohio (Figure 14, NWS-North Webster, IN). Further east, lake-enhanced snowfall piled up in northeastern Ohio (Figure 15, NWS-Cleveland, OH). The storm in the Midwest ended during the evening of February 14 as the snow tapered off to a few flurries in eastern Ohio as the storm headed off of the coast. Snow covered the ground from the Ozarks across northern Kentucky, and snow depths of 15 to 20 inches were found from eastern Illinois through central and northern Ohio (Figure 16).
Another surge of Arctic air was pulled into the Midwest behind the storm, and a number of temperatures records were set or tied in the wake of the storm. On February 14, Rolla/Vichy, MO recorded a high temperature of only 21°F, tying the record low maximum for the date, first set in 1970. Joplin, MO, tied its record low maximum with a reading of 25°F, tying the record first set in 1978. Just before midnight on February 14, Fort Wayne, IN, dropped to -6°F, breaking the old record low for the date of -3°F set in 1970.
SDH