The Kansas City NWS office posted this image showing that rivers have no measurable effect on tornado tracks.
The case for St. Louis reminded me that one of the worst tornado disasters in US history occurred when a tornado tracked through St. Louis, jumped the Mississippi River, and continued doing damage in East St. Louis. That was May 27, 1896. Besides busting the myth about rivers, it busted the myth that tornadoes do not hit major cities. At the time, St. Louis had a population close to 500,000.
The St. Louis Public Library has a great collection of photos and newspaper articles on the event. A total of 255 people were killed in both Illinois and Missouri. It was estimated to be an F-4 tornado on the Fujita scale, based on the damage seen in photographs.
Nine days after the event, a book was published based on newspaper accounts with lots of photos. It has recently been reprinted by Southern Illinois University Press and called “The Great Cyclone at St Louis and East St Louis, May 27, 1896”. Besides the incredible amount of detail on the storm’s damage, you are treated to some vivid and lurid prose (which was the newspaper style of the day).
The heavy rainfall across the Midwest in recent weeks has increased the risk of flooding on the Illinois and Mississippi Rivers. Rainfall totals were highest in western Illinois, northern Missouri, much of Iowa, southeastern Minnesota, and western Wisconsin, and ranged from 6 to 12 inches in the last 30 days. See the MRCC map below.
The National Weather Service produces forecasts of river levels based on current conditions and precipitation over the next 24 hours. At Quincy Lock and Dam, the Mighty Mississippi River is expected to be in “major” flood by sometime Thursday (first graph). See the latest forecast for this site here.
It is a similar story on the lower Illinois River. The current and forecasted river stage at Hardin, IL (second graph) shows that the river will reach “major” flood stage by next Monday. See the latest forecast for this site here. Of course, more rainfall in coming days will change these forecasts.
The US Corps of Engineers put out a press release today on the continued problems on the Missouri River due to the drought. From the release,
Based on the current soil moisture and snowpack conditions, 2013 runoff in the Missouri River basin above Sioux City, Iowa is forecast to be 20.5 million acre feet, 81 percent of normal. Runoff for the month of March was 55 percent of normal.
Full press release
At this time, 75 percent of the Missouri River Basin is in some stage of drought according to the US Drought Monitor. In addition 52 percent of the Upper Mississippi River Basin (above St. Louis) is in drought. See map below. Closer to home, recent rains and melted snow have kept the Mississippi River on the western boundary of Illinois in good shape this spring.
On February 20, the NWS Climate Prediction Center released their new outlooks for March and beyond. Below are the maps for March, spring (March to May), and summer (June to August).
The overall theme for Illinois is an increased chance of above-average temperatures through August. We have an increased chance of above-average precipitation in the March-May period, followed by equal chances in the June-August period. If it pans out, above-average precipitation for this spring should help with low water levels on both the Great Lakes and Mississippi River as well as alleviate drought concerns in northern Illinois.
If you are wondering when was the last time we had a spring that was both warmer and wetter than average, you do not have to look very far. The springs of 2004, 2006, 2009, 2010, and 2011 all qualified as having both above average on precipitation and temperature. In fact, our spring temperatures in Illinois have been at or above average in all but 2 years since 1998 (last figure).