February 15-21, 2007
Midwest Weekly Highlights - February 15-21, 2007
Cold, But Moderating
The third week of February began with frigid Arctic air settling in over much of the region in the wake of the February 12-14 snowstorm. However, temperatures quickly moderated as upper-level winds became more west-to-east, and the warmer air and strong winds combined to begin eating away at the deep snow cover over the central Midwest. Temperatures this week ranged from 16 °F below normal in Ohio to 3 °F below normal in northwestern Minnesota (Figure 1). Again, the coldest temperatures were found where the snow was deeper and more persistent.
Precipitation this week was well below normal except for southern Ohio (Figure 2). Precipitation was also above normal in the Michigan UP, where lake effect snow occurred in the strong northwest flow behind the February 12-14 storm. Drought conditions continue to persist across the northern half of Minnesota, northern Wisconsin, and the Michigan UP (Figure 3). Although some precipitation occurred in eastern Kentucky this week, longer-term dry conditions continued to persist and expand in southeastern Kentucky.
Aftermath of Blizzard
On the morning of February 15th the now intense low pressure system responsible for the blizzard conditions and heavy snow across the central Midwest was entering the Canadian Maritimes. However, effects of the storm were continuing to be felt. Road crews were continuing to plow roads. The heavy snow was responsible for two roof collapses in Indiana. In Muncie, IN (Delaware County), the roof of an elementary school collapsed under the weight of the ice and snow. A custodian noticed a bulge in ceiling tiles followed by the sound of steel roof supports and other materials coming down. The collapse also moved a steel structural beam out of place. The school was closed for its third consecutive snow day, and school officials estimated that the school might be closed the rest of the year for repairs. The back half of a skating rink in Gaston, IN also collapsed, severely damaging the building. Fortunately, no injuries were reported in either incident.
The deep snow cover contributed to some of the coldest weather of the past several years as Arctic high pressure settled in over the Midwest. Low temperatures on February 15 (Figure 4) and February 16 (Figure 5) were below zero as far south as central Illinois, Indiana, and southern Ohio. A number of records were set on both days in Ohio, and on February 16 in northern Indiana, and central Illinois.
Record |
Old Record/Year |
|
| February 15 | ||
| Cincinnati, OH | -1°F |
1°F/1963 |
| Cleveland, OH | -4°F |
-4°F/1963 |
| Dayton, OH | -5°F |
-3°F/1905 |
| Mansfield, OH | -3°F |
-2°F/1978 |
| Toledo, OH | -8°F |
-6°F/1905 |
| February 16 | ||
| Cincinnati, OH | 0°F |
0°F/1920 |
| Dayton, OH | -5°F |
-3°F/1885 |
| Fort Wayne, IN | -8°F |
-4°F/1920 |
| South Bend, IN | -7°F |
-6°F/1958 |
| Springfield, IL | -11°F |
-8°F/1885 |
In southern Illinois, there was minor flooding along the Little Wabash River due to the heavy precipitation, most rain, that fell in the area during the snowstorm.
Snow on Top of Snow
On Friday, February 16 an Alberta Clipper dove into the Northern Plains (Figure 6). This fast-moving system raced southeastward into central Illinois by the morning of February 17th. It left a swath of 1 to 4 inches of snow from southwestern Minnesota, through central Illinois, Indiana, southern Ohio, and eastern Kentucky by the time it moved to the East Coast (Figure 7). Blustery northwest winds on the back side of the low caused roads that had just been cleared of snow to be drifted over again, and driving conditions were hazardous throughout the areas that received more snow.
Warm-Up and Melting Begin
Temperatures rebounded quickly on February 19 as strong southerly winds became established over the Midwest. In areas without snow cover, temperatures maxed out in the mid 50s to mid 60s, while further north the mercury pushed into the mid 40s, an impressive warm-up considering the deep snow cover over the region (Figure 8). The moderating weather continued through the remainder of the period, although a weak cold front did temporarily put the brakes on the warm weather on February 20. This cold front helped trigger thunderstorms in the milder air to the south of the front, from southeastern Missouri through southern Illinois and western Kentucky. A severe thunderstorm watch was issued for the area on the afternoon of February 20, and there were numerous storm reports of large hail, with hail as large as 1.75 inch reported in Missouri and southern Illinois.
Temperatures rebounded on February 21, reaching the mid 60s again in southwestern Missouri and the low 50s as far north as northern Wisconsin. Only three days of milder weather and bright sunshine resulted in significant reduction of the snow cover between the beginning of the week (Figure 9) and the end of the week (Figure 10). The mild weather also caused ice to break up on many rivers, and minor flooding due to ice jams was reported along the Kankakee River in western Indiana and eastern Illinois.
SDH