As of noon on Monday, August 27, the track of Hurricane Isaac could pass through Illinois on Saturday (first map). Of course, it won’t be a hurricane – just a tropical depression. Even so, large rainfall amounts are expected to fall in parts of Illinois and Missouri (second map).
Back in 2008, I wrote about the impact of Hurricanes Ike and Gustav as the remains of those two systems dumped an impressive amount of rainfall across Illinois.
Perhaps a better comparison is with the drought of 2005. Like this year, Illinois was faced with a severe drought. However, the remains of four tropical systems brought needed rainfall into the region, especially southern Illinois (third map). The four tropical systems were Tropical Storm Arlene in June, Hurricane Dennis in July, Hurricane Katrina in August, and Hurricane Rita in September. In fact, the total rainfall from these four systems ranged from almost 8 inches in southern Illinois to about an inch in northern Illinois (fourth map). You can read more about the impact of tropical storms in 2005 in this article and this report (starting page 47).
Rain in Central and Southern Illinois on August 16
A cold front swept through the state on Thursday (August 16), triggering some impressive thunderstorms ahead of it. An area along Interstate 74 from Peoria to Champaign and an area between Interstates 64 and 70 received over an inch of rain (see map). Meanwhile, areas west of Springfield and north of Peoria received little or no rain.
The largest rainfall totals include Vandalia with 2.71 inches and Farmer City with 2.66 inches. Champaign received 1.82 inches while Bloomington had 1.93 inches, Decatur had 1.24 inches, and Peoria had 1.02 inches. Meanwhile Springfield received only 0.28 inches.
Agricultural Disaster Declaration for Illinois
Governor Quinn announced yesterday that federal disaster assistance is available to help Illinois farmers who suffered crop losses due to flooding this year (full press release).
As noted in the press release, the January-June period was the 4th wettest on record (27.2 inches, 8 inches above average) and an April that was the wettest on record with 7.59 inches.
I have generated a file with the monthly precipitation for 2011 for all available NWS cooperative observer sites in Illinois. The new 1981-2010 monthly precipitation normals for Illinois are posted as well. Additional precipitation data can be found at cocorahs.org using their precipitation summary product. It works best if you select your county and not the state.
2011: A Year of Extremes
I think we will remember 2011 as a year of extreme events. In Illinois we have already faced a February blizzard, flooding, record rainfalls, drought, and a heat wave. The latest newsletter of the NOAA’s Regional Climate Centers Program has highlighted several major events from around the country, including:
- wildfires
- tornadoes
- spring flooding in the Midwest
- record flooding in the Missouri River Basin
- drought
- snow
Check it out. I don’t know about anyone else but I’m ready for a quiet fall.
BTW, the Midwestern Regional Climate Center is housed at the Illinois State Water Survey.