January 25-31, 2005
Midwest Weekly Highlights - January 25-31, 2005
January Ends Gently
The last week of January found the Midwest largely isolated from both the northern and southern
branches of the jet stream, resulting in no large storms crossing the region. Only Kentucky
exceeded 0.50 inches of precipitation over most of its territory, followed by 0.25 to 0.50 inches
in the southern two-thirds of Illinois and the northern tier of the Midwest (Figure 1).
Precipitation was more than 50% below normal in eight of the nine Midwestern states (Figure 2).
Due to a clipper on the 25th and some minor lake effect periods, about 3-6 inches of snow fell
over a narrow band in the northern tier of the Midwest (Figure 3). Several inches fell in Illinois,
Indiana and surrounding states on the 29th due to moisture from a Gulf Coast low pressure center
riding north into cold air. The western Midwest was much warmer than normal, especially in
Minnesota, where temperatures reached 8-14°F above normal (Figure 4). However, the eastern
Midwest retained snow cover and cloud cover, which kept temperatures 2-6°F below normal for
the January 25-31 period.
Small Systems Rule
After the small clipper system passed through the Midwest at the beginning of the period, some sharply colder air entered the northern Midwest. Record low temperatures were recorded at Alpena, MI, on January 26-28, in Gaylord, MI, on January 26-27, and at Flint, MI, on January 28. On the coldest morning, the 27th, temperatures fell to -35°F at Embarrass, MN, -20°F to -35°F at 11 other places in Minnesota, -10°F to -20°F across the rest of Minnesota and Wisconsin, and -5°F to -15°F in Michigan (Figure 5). The intense cold caused an ice fog to form over the span of a bridge crossing an arm of Lake Superior in Duluth, MN, triggering a multi-car pile-up resulting in a death. The cold air reached down Lake Michigan, and, aided by a northeasterly flow, brought 2-4 inches of lake effect snow to Chicago over the night of January 26-27. However, by midday on the 27th, lake effect had dissipated for the most part, and extremely clear conditions prevailed over the central and eastern Midwest, allowing an excellent view of the snow cover via satellite (Figure 6, University Corporation for Atmospheric Research - UCAR).
On January 29, a low pressure center moved eastward along the Gulf of Mexico. Ahead of the storm, some moisture moved northward into the southern and central Midwest, bringing light snow and freezing rain or drizzle to a large swath of the Midwest ("S-" and "ZR" symbols in Figure 7, College of DuPage - COD). The core of the precipitation extended from St. Louis to the Ohio Valley, and created a large zone of slippery conditions (Figure 8, Storm Prediction Center - SPC). A lengthy but narrow band of snow formed across Illinois, Indiana, and Ohio (Figure 9, UCAR), leading to 2-4 inches generally with some isolated greater amounts. Travel conditions were especially severe in the southern Ohio and northern Kentucky area, where slightly warmer conditions allowed 0.1 to 0.3 inches of ice to be deposited in light freezing rain. Many traffic accidents were reported by the media, but no weather-related fatalities were cited.
The week ended with some fog problems in the mornings in the western Midwest, as warmer, more humid air entered the area. There were also some light showers and snow flurries in the Ohio Valley on the 31st, but this did not contribute to the runoff in the region. The rivers that flooded during mid-January had largely retreated to below flood stage, leaving only a few rivers still above flood stage (yellow dots in (Figure 10, NWS). At this point, the federal disaster declaration in Indiana had been expanded to 85 counties, covering almost the entire state (Figure 11, FEMA). Over 2,000 individuals applied for assistance, and $2.4 M was approved. More than $10 M in public infrastructure damage was identified. While the central and eastern Midwest continues to recover from flooding rains, there is considerable concern in the agricultural community about saturated ground and spring rains potentially causing delays in spring planting. However, on the opposite side of the Midwest, there are concerns about continued drying in Iowa and Minnesota and in the Western Corn Belt. The availability of water to maintain a large enough flow in the Missouri River to sustain summer barge transportation is also problematic. As January ends, the Midwest has sustained large, and, in some cases, record climate anomalies that may leave the region more vulnerable than normal to any further climate anomalies in the upcoming spring.