November 1-7, 2005
Midwest Weekly Highlights - November 1-7, 2005
Deadly Tornado Rakes Southern Indiana
The conditions of the first week of November were
more like mid-spring, with warm temperatures, high
humidity, and active severe weather. A swath of 1-2.5
inches of precipitation fell between southern Missouri
and central Michigan (Figure 1), helping to nibble at
the ongoing drought in the central Midwest. A few
already dry areas were missed, however, including
Kentucky and western Iowa, both of which received
less than 50% of normal precipitation (Figure 2).
Almost the entire Midwest was 6-9°F warmer than
normal for the November 1-7 period (Figure 3). The
combination of a strong jet stream aloft and plenty of
moist air from the south created the conditions for a
severe weather outbreak on November 5 and 6. As a
squall line swept through the central Midwest around 2
AM on the 6th, a significant F3
tornado set down (circled cell in Figure 4, University
Corporation for Atmospheric Research - UCAR) in northern
Kentucky and traveled more than 40 miles, crossing the Ohio River and
churning a 400+ yard wide swath through some
suburbs of Evansville, Indiana, including a large trailer
park. The current death toll is 22, making it the
deadliest U.S. tornado in 6 years, and more than 200
were injured, many severely enough to require
hospitalization. Initial damage estimates exceeded 100
million dollars, and a federal disaster declaration has
been made for the impacted counties in Indiana.
Warm Weather Preceded Storms
The month started with a large area from Oklahoma to
Kentucky being placed under a Red Flag warning to
guard against wildfires (Figure 5, NWS). Sioux City,
Atlantic, Webster City, and Carroll, IA, set new high
temperature records in the upper 70s and lower 80s on
the 2nd. A clipper system moving through the
northern Great Lakes and cooled that area briefly on
the 4th; two locations in northern Minnesota had their
first 1 inch snow fall of the season. During the day on
the 5th, Paducah, KY, also set a new high temperature
record (78°F), heralding the arrival of strong southerly
flow ahead of a very intense low pressure system
entering the region through Missouri (Figure 6,
College of DuPage - COD). This surface airflow
tapped the Gulf of Mexico moisture source and
brought November 5 dew points into the upper 50s and
lower 60s as far north as Illinois and Indiana (Figure 7,
COD). On top of this surface set-up, a dip in the very
strong jet stream aloft was coming right over the
region by early evening (Figure 8, COD). The stage
was set for some strong thunderstorms, and a line of
severe storms developed during mid-evening in
Missouri, as anticipated by a tornado watch issued
earlier (Figure 9, NWS).
The Killer Outbreak
About 261 severe weather events were recorded on the evening of the 5th and early morning of the 6th (Figure 10, NWS). Some 5 tornadoes were confirmed in southern Missouri, causing some structural damage in widely scattered locations, but only a few minor injuries. A strong F2 tornado hit Munfordville, KY, 70 miles south of Louisville, damaging 80 homes in the town center, including 46 severely damaged, and 25 destroyed. Fortunately, no one died, despite some $2 million in damage given initial estimates. It was the strong F3 tornado that tracked through northwestern Kentucky and southern Indiana that became an historic event.
The thunderstorm that spawned the tornado was embedded in a squall line of other storms that suddenly developed a more cellular, individual storm mode prior to tornado development. The tornado first touched down west of Henderson, KY, and moved at amazing speeds of up to 75 mph across the Ohio River north of Henderson, and then northeastward between the centers of Evansville and Newburgh (approximately 2:03 AM, the time of the radar image in Figure 4) before taking a long trek through a more rural area (Figure 11, NWS). There were several locations along the path where the tornado sliced through occupied areas. No one died in Kentucky, but the Ellis Park horse racing track was damaged heavily, and half of one grandstand was destroyed. Three horses died from storm injuries, and ten of the horse barns and out-buildings were severely damaged. After crossing the Ohio River a third time, the twister plowed through the Eastbrook Mobile Home Park, destroying 123 mobile home and severely damaging 80 others. Despite the warnings from the National Weather Service 10 minutes prior to the arrival of the tornado, the residents were not alerted for the most part, being sound asleep. When the storm itself woke them up, most did not have time to seek shelter. A total of 18 residents died the day of the storm, and a number of severely injured victims remain in intensive care at area hospitals. More than 200 people were injured sufficiently to require hospital treatment. The county of Vanderburgh suffered considerable additional damage to other homes and towns, and was still accumulating damage totals. The town of Newburgh just missed a direct hit to the town center, with the tornado passing just north of the unincorporated boundary. Many dwellings were severely damaged there and in several towns along the path in the next county. Four people died in two places in Warrick County: a family of three losing their home and lives in DeGonia Springs, and one person dying in their home at the county seat of Booneville. More than 525 homes and businesses were damaged by the tornado in Warrick County, with 335 houses destroyed, 156 receiving major damage, and 176 receiving minor damage.
This tornado was the worst in terms of death toll in the United States in 6 years, and worst in 55 years in Indiana. Initial estimates of total losses are about $100 million, but this figure might rise still higher. Ironically, up until the 6th, this year was one of the least deadly on record for the United States.
The Low Center Leaves the Midwest
The low pressure center continued to the north of the Great Lakes, causing very strong straightline winds in the gradient between it and the high pressure to the south. Very high wind gusts where measured at Detroit (55 mph), Toledo (62 mph), and along the lake shores, with the highest measurement of 67 mph at Presque Island Light. Isolated damage and power outages occurred. However, cold air only penetrated as far south as the Upper Peninsula of Michigan, where several places received 2-5 inches of snow. In fact, the week ended with a return to southerly flow, and the possibility of more energetic weather systems with the potential for triggering severe weather in the coming week.