October 18-24, 2005
Midwest Weekly Highlights - October 18-24, 2005
Fall Finally Arrives
The Midwest experienced a marked change in the weather pattern the
third week of October. The unseasonably warm and summer-like
weather the characterized the first half of the month was replaced by
weather that was colder than normal by the end of this period.
Temperatures this week ranged from 3°F above average
in the far southern portions of the region to 4°F below average
in the west and far north (Figure 1). Precipitation was generally confined to a wide
band across
the central Midwest, were a low pressure wave moving a long a front
produced rainfall from Missouri through Ohio (Figure 2).
Summer Weather
Swept Away
The last days of summer-like weather occurred on October 18 and 19 as
strong southwesterly flow dominated the Midwest weather. More
than 20 communities in Minnesota reported highs of
80°F or
higher on October 18 (Figure 3).
Mankato, MN
established a new record high of 81°F.
A cold front pushing through the Midwest on October
19
brought markedly cooler weather to the northern half of the region, and
the warmest weather was found across the southern Midwest (Figure 4).
Springfield, MO reached 88°F, a record high for
the day breaking the old record of 84°F in 1963.
Joplin, MO
soared to 93°F, shattering the previous record of 85°F
set in
2003. It also was the latest 90°F reading in Joplin,
the
previous record set on October 14, 1963.
Heavy Rain in
Central Midwest
The cold front that pushed through the Midwest on October 19 stalled
along the Ohio River on October 20, and a strong low pressure system
developed on the front in eastern Kansas. As the low moved
east
along the front and intensified in response to a strong upper level
low, a large area of showers and thunderstorms developed out ahead of
the system. The heaviest precipitation occurred in Missouri
and
western Illinois on October 20, and in Illinois and Indiana on October
21. By the time the system exited the Midwest on October
22, wide band of one to two inch rainfall amounts was evident
from northern Missouri across central Illinois, Indiana, and into
southern Ohio. Radar estimates and actual observations
indicated
some locations received three to four inches of rain during the event,
more than the normal total October rainfall in many locations (Figure 5).
However, northern
portions of the region, especially those in Extreme Drought on the
latest U.S. Drought Monitor (Figure 6),
received significantly less
rainfall, generally less than one-half inch. In the wake of
this
system the first freezing temperatures of the season were observed
across much of central Minnesota, the northern half of Wisconsin, and
Michigan (Figure 7).
Cold Weather Gains
Foothold
A strong upper level low pressure system dove into the Midwest on
October 22-23, bringing with it much colder weather colder weather
(Figure 8). Temperatures during the last three days of the
period ranged from 3°F to 5°F below normal across the
northern Midwest to 8°F to 12°F below normal across the
central and southern portions of the region (Figure 9),
compared to departures of 4°F to 10°F above
normal across the southern half of the region the first four days of
the period. A few scattered light showers developed across
the eastern half of the region as the upper low moved through.
-SDH-