December 8-14, 2003
Midwest Weekly Highlights - December 8-14, 2003
The
active weather pattern continues.
A series of storms moved through the Midwest during the second week of
December bringing plenty of precipitation and the coldest air of the
season to the Midwest. Temperatures this week ranged from 2 to 3
degrees above normal across the central and upper Midwest to 2 to 4
degrees below normal from southwestern Minnesota through western Iowa
and Missouri, and eastern Ohio (Figure 1). Precipitation was three to five
times normal in a band from northeastern Missouri through northwestern
Illinois to southern Wisconsin. In general, precipitation was
well above normal north of a St. Louis to Chicago line to central
Minnesota (Figure 2).
The storm track was such that the northwestern two-thirds of Minnesota
and the southeastern half of the Midwest received well below normal
precipitation. Some of the heaviest precipitation fell in the
areas that have been characterized as having extreme drought on the
latest U.S. Drought Monitor (Figure 3), and a significant portion of that precipitation came as snow (Figure 4).
The first of the storms this week began developing in Rockies on
December. 8. By the morning of December 9 low pressure was
located in northern Texas, and heavy snow was already falling from
northwestern Kansas into northwestern Iowa and southern
Minnesota. Winter storm warnings were posted for much of Iowa and
southeastern Minnesota. Mild air streamed northward from the Gulf
of Mexico behind a warm front that bisected Missouri, Illinois, and
Indiana. Rain, drizzle and fog spread over these regions. The
storm moved northeastward through Illinois and into Michigan by late
afternoon on December 10. One to three inches of rain fell in
northeastern Missouri, eastern Iowa, and western Illinois before cold
air came in behind the system and changed the rain to snow. In
the storm’s wake a wide band of snow covered the ground from
southwestern Missouri through Iowa, southeastern Minnesota, and the
northwestern half of Wisconsin (Figure 5). The heaviest snow fell in
southwestern Missouri, with general snowfall of 4 to 8 inches (Figure 6, NWS).
Thunder snow was reported near Joplin, MO and produced locally heavier
snowfall. Carthage, MO (about 15 miles northeast of Joplin) received
14.5 inches. Strong gusty winds produced near blizzard conditions
in parts of the Ozarks. Further north in Minnesota, 9.5 inches of
snow fell at the Chanhassen, MN National Weather Service office (Twin
Cities), the second largest single day snowfall for the Twin Cities.
The largest single day December snowfall was 12.0 inches on December
28, 1982. Ten to thirteen inches of snow fell in parts of northern
Wisconsin. By December 11 snow covered most of the ground in the
Midwest west of the Mississippi River (Figure 7).
The coldest air of the season settled over the Midwest on December 11
behind the storm. Minimum temperatures on the morning of December
11 plunged well below zero over the deep snow cover over Minnesota (Figure 8, Unisys).
A reading of -30F was recorded in Tower, MN and -26F was recorded in
Embarrass, MN.
The lake effect snow machine cranked up on December 12 over
northeastern Minnesota, northwestern Wisconsin, the Michigan Upper
Peninsula (UP) (Figure 9,
NWS), and western lower Michigan (Figure 10, NWS) as the cold air streamed across
the relatively warm waters of the Great Lakes. Snowfalls of
14 to 22 inches were reported in the western UP of Michigan.
Another storm began to organize and head out of the Southern Plains on
December 13, producing more winter weather across the Midwest. By the
time the storm moved into the eastern U.S., 1 to 2 inches of new snow
covered the ground from Missouri east through Ohio (Figure 11). Some
heavier snowfall amounts of 4 to 6 inches did occur with this system in
central Missouri into western Illinois.