October 2007
Midwest Overview - October 2007
Unseasonably warm temperatures at the beginning of October resulted in hundreds of daily temperature records broken across the Midwest (please see the October 10, 2007 Climate Watch) and contributed to October 2007 being above average in temperature throughout the entire region (Figure 1). The warmest temperature departures were in northeastern Ohio and northern Michigan with average temperatures for the month as much as ten degrees above normal. But even in the western half of the Midwest, temperatures were still two to three degrees above average. Cleveland and Mansfield, OH experienced their 3rd warmest October on record and Alpena, Gaylord, Sault Sainte Marie and Traverse City, MI all had their 5th warmest October. Indianapolis, IN had their warmest October in 60 years and the 4th warmest on record. Milwaukee, WI and Rochester, MN also had their 4th warmest October on record.
Precipitation varied widely across the region but the majority of the Midwest received normal to above normal rainfall during October 2007 (Figure 2). Minnesota and Iowa ended the month with their state average precipitation ranking in the top five of wettest Octobers for their states and several individual stations set monthly precipitation records. The rains that fell during the last two weeks of the month were very welcome across the southern Midwest and helped Paducah to reach their 8th wettest October on record. The precipitation that fell during the month finally reduced or ended much of the drought that had plagued a large portion of the Midwest during much of the growing season (Figure 3).
Record Severe Weather Outbreak
October 2007 was a very busy month for severe weather across the Midwest (Figure 4). Tornadoes occurred during every single week except the last, with the peak of the activity occurring during October 17-18. According to the Storm Prediction Center, this outbreak set a national record for tornado outbreaks in October with 87 tornadoes forming nationwide in the three day span of October 17-19. This total far surpassed the previous record of 63 tornadoes that had been set along the Gulf Coast from October 23 to October 27, 1997. Of the 87 tornadoes, six of them occurred in the coastal regions Texas, Louisiana, Mississippi and the Florida Panhandle. The remaining 81 stretched across the mid-section of the country. The outbreak was triggered by the positioning of the jet stream from southwest Texas to northeastern Michigan allowing readily available moisture to stream inland from the Gulf of Mexico and creating conditions favorable for tornado activity in the country's mid-section. A low pressure system in the Gulf was the primary cause for the six tornadoes in that region between October 17-19. The remaining 81 tornadoes were the result of an upper level trough of low pressure that extended from the Central Plains through the Great Lakes. Intense thunderstorms developed ahead of this system and tornadoes were reported over a large portion of the central US with five fatalities reported. The total number of tornadoes during October 2007 numbered at 105, which was second only to October 2001 with 117 twisters. The records date back to 1950.
With respect to those fatalities, one item of note occurred this month when the US House passed "CJ's Home Protection Act" on Tuesday, October 30, 2007. It requires new manufactured and mobile homes to come equipped with NOAA weather radios in an effort to help prevent deaths from tornadoes that disproportionally occur in manufactured housing. It was named after a two year old Evansville, IN boy who was killed by a tornado in 2005. His mother pushed through a state law in Indiana and has lobbied Congress for the national requirements. According to bill, 20 million Americans live in manufactured homes and the fatality rate is 10 times that of permanent structures. The House bill was based on Indiana legislation that required weather radios in manufactured housing placed in manufactured home communities but expands on the requirements to all new mobile and manufactured homes. It was approved unanimously and now goes to the Senate.
Temperature and precipitation records for the month of October can be viewed in Table 1.
MCP