February 22-28, 2005
Midwest Weekly Highlights - February 22-28, 2005
Quiet But Wintery End to February in the Midwest
During the last week of February, the Midwest was impacted almost
daily by weak clipper systems or glancing blows from stronger systems
moving around the region. The total precipitation for the week was
heaviest along the northern and southern edges of the Midwest (Figure 1),
but did not generally exceed an inch even in these zones. The
saturated areas of the northern Ohio Valley had a break from major
precipitation, receiving less than 25% of normal for the week (Figure 2).
However, most of the precipitation statistics used in making the
map represented stations that report in the morning. Therefore, the
weekly maps do not include the bulk of the precipitation that fell after
the morning of the 28th, when a substantial low pressure system
traveled through the Midwest. Snowfall for the week was also
concentrated in two bands, a zone of near-normal amounts of snow for
the week across the northern Midwest and Great Lakes region, and
another minor concentration near the Ohio River (Figure 3). Despite
the cold end to the month, the temperatures for the week were slightly
above normal in the central-western Midwest due to warm frontal
influences earlier in the week, and 4-8°F below normal elsewhere to
the north and east (Figure 4). The month of February 2005 ended as
the 13th warmest and 44th wettest for the Midwest in 110 years.
Light but Frequent Activity Impacts the Region
On the 22nd, a clipper system passed north of the Midwest, trailing a trough through Michigan and producing light snow. The next day, a more substantial storm traveling eastward across the southern U.S. forced warmer and moister air over the cool air in place, establishing a band of light precipitation across the southern Midwest (Figure 5, University Corporation for Atmospheric Research - UCAR). Total snowfall amounts at the northern edge of the band were small (Figure 6), limited to less than 4 inches. Another clipper system approached the Midwest on the 24th, with a warm front ahead of the low center being the focus of most of the precipitation recorded by the morning of the 25th (Figure 7). This clipper system had a trailing cold front, but it was quite dry, cooling the Midwest on the 26th but not triggering much precipitation except in the northern Great Lakes snow belts. Finally, on the 27th, another low pressure center moved across northern Minnesota (Figure 8, College of DuPage - COD). However, this low intensified under the influence of the northern branch of the jet stream (Figure 9, COD), so that by the next day, it was a very strong surface low (Figure 10, COD). Precipitation fell along the frontal boundary (Figure 11, UCAR), as well as ahead of the front, and continued through the 28th (Figure 12, UCAR). The precipitation field from the Great Lakes low merged with the large coastal storm bringing heavy snow to the east side of the Appalachian Mountains. The combined snowfall totals for February 28 and March 1 were 6-12 inches over the Great Lakes region (Figure 13), with further lake effect snow and general precipitation continuing. Besides flight cancellations due to problems at east coast airports, and some school closings in Kentucky, the only impacts of note had to do with increased road hazards and accident reports.
During this last storm of the month, Marquette, MI, set a new record for daily snowfall on February 27 of 6.1 inches. Houghton Lake, Alpena, and Muskegon, MI, set daily snowfall records for February 28 of 6.0, 5.3, and 3.5 inches, respectively. Further south in Kentucky, Jackson set a new daily record for total precipitation of 0.97 inches, and tied its previous snowfall record of 1.5 inches.