January 15-24, 2004
Midwest Weekly Highlights - January 15-24, 2004
The Great Lakes Get "Clipped" and "Effected"
While no large storms came roaring into the Midwest Rockies during the January 15-24 period,
the Great Lakes region had a very active week, with four separate clipper systems riding in from
Canada along the northern branch of the jet stream. In between clipper systems, lake-effect snow
fall was considerably enhanced, especially in the Upper Peninsula (UP) of Michigan and northern
Lower Michigan. The region had one near miss, a strong low pressure center that passed to the
south of Missouri and Kentucky along the southern branch of the jet stream on 17th and 18th.
Most of the 0.50 to 2.00 inch precipitation totals for the week in Missouri, southern Illinois, and
Kentucky fell on these days (Figure 1). Precipitation was also above normal for the period in
Michigan, especially in zones of enhanced lake effect snow (Figure 2). The snow from the
clipper systems on January 14-15, 17-18, 21-22, and 23-24 amounted to two feet in the UP of
Michigan (Figure 3). The 10-day period started above normal in the western Midwest on January
15-17, but turned sharply colder from the 18th onward, leading to 10-day average temperature
departures 6 to 14°F below normal in the northeastern two/thirds of the region (Figure 4).
Unfortunately, most of the precipitation once again missed the drought areas of northwestern
Missouri, Iowa, and Minnesota (Figure 5, National Drought Mitigation Center).
Clipper Systems
The term clipper system is used to refer to low pressure centers that dip down from Canada into the far northern U.S. and bring snow and cold temperatures to the region. The January 14-15 storm was discussed last week. Mild temperatures were retained in the western Midwest over the next several days, and as the large western low moved south of the region, overrunning warm moist air was brought over the cold air in the central and eastern Midwest, leading to freezing rain in Chicago, Indianapolis and other locations on the 17th. More than 60 accidents were reported in Chicago, and 103 accidents around Indianapolis, but no life-threatening injuries resulted. Fog also formed, delaying flights from Chicago 1-2 hours. The second clipper system of the week passed from the Arrowhead of Minnesota through Michigan late on the 17th, bringing snow throughout that area. More importantly for the Midwest as a whole, one of the coldest air masses of the year followed behind a cold front dragged southward by the clipper. By the morning of January 19th, temperatures reached -35°F in northern Minnesota (Figure 6). Several of the last freighters of taconite ore for the season were locked in ice near Duluth, and took several days to free. The cold also made it difficult during a recovery operation for a plane crash on Lake Erie. A homeless man under a bridge died of hypothermia in Chicago; all but 100 of the 6,000 beds for homeless were filled that night. Many major cities enacted cold weather plans to gather people without heat to shelters. In Detroit, it was reported that about 100 water main breaks occurred, some of which also caused power outages. Natural gas and oil prices continued to skyrocket. To the relief of the organizers of the St. Paul Winter Carnival, the cold air was very beneficial for the health of the ice palace they built out of 27,000 large blocks of ice.
The third clipper system of the week on January 21-22 brought 2-4 inches to most places along
its path from the northwestern Great Lakes through to Pennsylvania. The small snowfall
combined with temperatures too cold for road salt to be effective, glazing the roads under the
pressure of car tires. In Milwaukee, more than 150 auto accidents were reported on the 23rd, and
one person died near Madison, WI. Wind chill values exceeded -45°F in the northern Midwest
on the morning of the 24th. The final clipper system of the 10-day period followed a slightly
more southerly trajectory across the Midwest as the zone of strongest upper level flow also
slipped further south (Figure 7, College of DuPage). The swath of snow (Figure 8, COD) moved
in this case from northwestern Minnesota, through Wisconsin, southern Michigan, and Ohio,
again disrupting transportation. Two were killed skidding off an icy road near Perryville, MO.
As the clipper system crossed the region, a major winter storm was approaching from the
Southwest, with an active weather pattern expected to continue for the Midwest through the end
of the month.
Lake Effect
After the second and third clippers reinforced cold air in the region, Great Lakes lake-effect precipitation was widespread, especially in the UP of Michigan and western Lower Michigan. Snow depth in the UP exceeded 15 inches over a wide area, and was much more in spots (Figure 9, NWS). A particularly beautiful display of lake-effect convection was seen from orbit on the 22nd, when cloud streets stretched all the way across Lake Superior (Figure 10, COD), and all along the downwind shore of Lake Michigan (Figure 11, COD). Corresponding radar images show the related lake-effect precipitation in the UP (Figure 12, NWS), and northwestern Lower Michigan (Figure 13, NWS).