February 2005
Midwest Overview - February, 2005
A Well-Tempered February Makes Few Headlines
The Midwest experienced moderate temperatures and well-place precipitation during February
2005. Abundant precipitation fell where it was needed in the western portion of the region to
arrest the onset of dryness in that area (Figure 1). Fortunately, below normal precipitation
amounts fell in the Ohio Valley (Figure 2), greatly benefitting an area still saturated from the
flooding precipitation of late December and January. Snowfall amounts were substantial in the
Great Lakes snow belts of northern and western Michigan (Figure 3), making conditions more
seasonable at these locations. This month also brought beneficial snow to a snow-lacking region,
with a band of above normal snow totals from central Minnesota through northern Wisconsin (Figure 3a). While precipitation amounts for the Midwest were near normal overall, at 44th
wettest in 110 years, temperatures were 4-7°F above normal for most of the Midwest (Figure 4),
resulting in the 13th warmest February in 110 years. The precipitation in southwestern Iowa and
northwestern Missouri ameliorated moderate drought conditions, although abnormally dry
conditions lingered through the end of the month due to a lack of late-February precipitation and
warmer than normal temperatures (Figure 5, National Drought Mitigation Center). Iowa was
both the wettest (16th wettest) and warmest (11th warmest) state in the Midwest compared to its
110 year record. Noteworthy events during the first half of the month included widespread air
pollution alerts on the 3rd, many maximum temperature records set on the 12th, and a large
storm with moderate freezing rain totals in southern Michigan and heavy rain totals from
Missouri to Indiana on the 13th and 14th. In the latter half of the month, only a major winter
storm on the 20th rises to the level of noteworthy event. This storm brought 6-14 inches of snow
to places lacking it from Minnesota through central Michigan, and had significant impacts on
transportation, including 4 weather related fatalities from automobile accidents.
Winter 2004-05
The Midwest had its 5th wettest and 15th warmest winter in 110 years. While warm conditions are generally expected during El Niño winters in the region, wet conditions are not, so this winter was quite unusual from this perspective. Blocking situations were common in the eastern Pacific, which led to a split jet flow over North America during much of the winter. When the southern branch was stronger, the Midwest would be visited by storms from the Southwest capable of tapping Pacific and Gulf of Mexico moisture. At other times, frequent clipper systems would move through the northern Midwest. Precipitation totals for the season varied from 2-4 inches in the northwestern Midwest to over 12 inches in the Ohio Valley (Figure 6), with much of the latter arriving between mid-December and mid-January. Almost the entire Midwest was above to well above normal in precipitation (Figure 7). Substantial flooding occurred in the Ohio Valley and in Illinois during mid-winter, because a high percentage of this precipitation arrived as liquid rain. Therefore, except for the great snow storm of December 23-24 in southern Illinois/western Kentucky, Indiana, and western Ohio, most of the snowfall was limited to the northeastern half of the Midwest (Figure 8). Minneapolis, MN, and points south had a below normal winter season for snowfall (Figure 9), while the Arrowhead of Minnesota was several feet above normal. These consistently snowy areas were also most likely to be near normal in temperature for the season, while most of the Midwest was 2-4°F above normal for the winter (Figure 10). It is estimated by the Red Cross that more than $500 M in weather disaster damage occurred in the Midwest during Winter 2004-05 due to snow and ice storms, flash floods, and river flooding concentrated in Illinois, Indiana and Ohio.