November 2006
Midwest Overview - November, 2006
November Starts Warm, Ends Cold and Snowy
Temperatures across the Midwest during November were above normal for the first month since August 2006 (Figure 1). Temperatures were warmest across Wisconsin and northern Minnesota, where departures were 3°F to 5°F above normal. Elsewhere around the Midwest, temperature departures ranged from around normal to 1°F above normal across southern Illinois and western Kentucky, and got warmer as one headed further north, where departures were generally 2-4°F above normal across a large area.
Precipitation during November largely came from two events, one on the 10th, and the other on the 30th. Aside from those two major storms, only sporadic and light precipitation was generally found during November. Most of the Midwest, however, did receive between 75 and 100% of normal precipitation during November (Figure 2). A few exceptions were found across western Illinois and southern Missouri where totals were 125 to 150% of normal, and across western Iowa, Minnesota, and northern Wisconsin, where totals were 25 to 50% of normal for this month.
The biggest stories this month revolved around the two big storm systems that crashed through the Midwest during the month, and the record warm temperatures that were found over the Thanksgiving Holiday. Just prior to the first major snow event of the year, very warm temperatures were found across the Midwest (Figure 3). Maximum temperatures exceeded 70 degrees across a very large area, including the entire state of Iowa, and 80 degree weather was found in western Missouri, western Iowa, and even southern Minnesota. However, the heat would quickly retreat. On November 9-11, a storm system ejected out of the desert southwest and moved northeast into the Midwest. Snow was heavy across northeastern Iowa, southeastern Minnesota, and western Wisconsin, as the deformation band set up across this area (Figure 4). Once all was said and done, many locations within a very narrow axis received 4-8" of heavy snow (Figure 5).
After that, the weather turned quiet and warmed again as we headed toward the Thanksgiving Holiday. During this week, temperatures exceeded 60°F in Chicago, IL for six consecutive days - a string that has not been seen since records began in 1871. Thereafter, a strong arctic front blasted through the Midwest on the 27th, ushering in very cold temperatures. Meanwhile, an area of low pressure developed along the tail end of the front and moved northeastward into the Ohio Valley. Rainfall from this system was very heavy, with several locations seeing in excess of 2.00" of rain (Figure 6). As the low moved northeast, cold air became entrained in the system and the precipitation switched to sleet, freezing rain, and eventually snow. On the final day of the month, the snow became heavy across parts of Missouri, Illinois, and Wisconsin, where some locations received between 12 and 18 inches of snow (Figure 7). The heavy snow, ice, and wind caused power outages to some 2.4 million persons living in Missouri and Illinois, with over 500,000 customers without electricity in St. Louis, MO.
Seasonal Overview: Fall 2006
The fall of 2006 started out very active and wet, with several locations in Kentucky experiencing September rainfall totals in excess of 10 inches. In addition, at least two major severe weather outbreaks took place during September, one affecting the greater Minneapolis, MN area, and the other across the I-70 corridor of southern Missouri, Illinois, and Indiana. October and November were quiet, with October being colder than normal and November being slightly warmer than normal. The final few days of November featured a memorable snow and ice event for a good chunk of the Midwest.
For the whole season, temperature were coolest across the south and west, with departures of 1 to 3°F below normal. Temperatures warmed some in the northern parts of Minnesota, Wisconsin, Michigan, and eastern Ohio, where departures in these areas ranged from around 0°F to about 1°F above normal (Figure 8). Precipitation totals were greatest across the Ohio Valley this season, with portions of Kentucky, Indiana, southern Illinois, and southern Ohio receiving 150 to 200% of normal precipitation. Elsewhere across the region, precipitation totals ranged from only 50% of normal in northern Wisconsin, northeast Minnesota, and western Missouri, to 75 to 100% of normal in all other areas (Figure 9).
Kruk