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.

Rainfall totals across Illinois in the last 24 hours. Click to enlarge.

Are Modern Corn Hybrids Less Vulnerable to Drought?

It is often repeated that the modern corn hybrids are less vulnerable to drought. Is it true? Well, yes and no. Emerson Nafziger, University of Illinois agronomist, has put together an analysis of corn yields between 1988 and 2012 in Illinois.

In his own words, here is what Emerson found:

“To look at how much yield was lost to drought in 1988 and 2012, I projected trend-line yields for each drought year based on yields over the 30 previous years. The expected (trend-line) yield for 1988 was 129 bushels per acre; the actual yield was 73, so the loss was 56 bushels per acre. In 2012, the expected yield was 173 bushels per acre and the estimated yield is 116, so the projected loss is 57 bushels per acre. Measured in terms of bushels per acre less than expected, the two years are almost identical.

The 1988 yield represents a loss of 44% of expected yield, while in 2012, with higher yield expected, the percentage loss was only 33%. So in relative terms, the 2012 crop lost less yield than the 1988 crop, but in absolute terms, losses were almost identical between the two years.

It’s not clear whether percentage loss or bushel loss is the better measure of drought effects, but what is clear is that serious drought continues to cause serious yield loss, even with today’s faster-growing, higher-yielding hybrids…”

Here is the full article:

Drought Impacts in Illinois

I took some photos on my way back from a Drought Response Task Force meeting in Springfield on August 9. Here are two of the most interesting. The first photo is a farm pond near the Interstate between Decatur and Champaign. Obviously, it is in bad shape.

The second photo shows the “firing” of corn on August 9. This usually indicates a nitrogen deficiency in corn and is common during dry weather. I saw a range of conditions in the corn crop between Springfield and Champaign. Some fields were completely brown while others were relatively tall and green.

What you can’t see from staring out the car window is the condition of the ears on the stalks. However, the August 10 report from USDA predicts that the average corn yield in Illinois this year will be 116 bu/acre, compared to 157 bu/acre in 2011. That’s a 41 bu/acre reduction or a 26 percent drop in yield.

They predict the soybean yield in Illinois will be 37 bu/acre, compared to 47 bu/acre in 2011. That’s a 10 bu/acre reduction or a 21 percent drop in yield.

Farm pond in east-central Illinois (author’s photo). Click to enlarge.
Corn field in Champaign County, Illinois, on August 9. Click to enlarge.

US Drought Monitor for Illinois

The latest US Drought Monitor released today shows that the D3 “exceptional” drought has expanded in portions of northwestern Illinois.

The state of Illinois maintains a website on the activities of the Drought Response Task Force. In addition, the Illinois State Water Survey website has postings and archives of  information on the drought as it develops.

U.S. Drought Monitor for Illinois. Released August 9, 2012. Click to enlarge.

Long String of Warm, Dry Weather in Illinois

I have updated the plots of statewide monthly temperature and precipitation departures that start in January 2011 and include July 2012. We struggled with dry weather in 2011 but saw some recovery in November and December. However, every month in 2012 has been below normal. In addition, the last three months have shown increasingly larger departures with July being the worst.

Statewide monthly precipitation departures from normal for Illinois. Click to enlarge.

The statewide monthly temperature departures from January 2011 to July 2012 show that 2011 was a moderately warm year with 9 out of 12 months above normal. But the really warm weather (relative to the time of year) started in November 2011 and never really stopped through July of this year.

Statewide average temperature departures from normal for Illinois. Click to enlarge.

Rains Over the Last Week in Illinois – Good News for Some

Parts of Illinois received some welcome rains in the last week. The map below is a screenshot from a precipitation product provided by the Southern Region of the National Weather Service. This is based on high-resolution radar data, and corrected using the much sparser rain gauge network.

The areas in green received somewhere between an 1.0 to 2.5 inches, while the areas in tan or light yellow received over 3.0 inches. As a rule of thumb, we get about an inch of rain per week in August. So any area in green made small gains on the rainfall deficit for the season. Meanwhile those areas in blue received less than an inch and fall farther behind on the rainfall deficit for the season.

Locally, I got 0.68 inches at my house in Champaign over the weekend. In fact, I got more rain in the early morning hours of Sunday than in all of July.  My guess is that soybean farmers will be happy with anything we can get in August.

Seven day precipitation total ending August 6. Click to enlarge.

Tornado Drought

Tornado Drought in Illinois

One of the side effects of drought is that usually reduces the amount of severe weather we experience in Illinois. This year was a good example of this. After the deadly Harrisburg tornado on February 29, things have been relatively quiet. Here is the monthly breakdown of tornado reports in Illinois, as reported by the NOAA Storm Prediction Center:

  • 2 in January
  • 4 in February
  • 8 in March
  • 0 in April
  • 8 in May
  • 0 in June
  • 1 in July
  • 23 total by the end of July
Severe weather reports in Illinois for 2012 through the end of July. Figure courtesy of NOAA’s Storm Prediction Center.

Tornado Drought in the US

Harold Brooks of NOAA wrote about the US tornado drought on his blog. Here is the figure he used in his post for the US.

The number of tornadoes reported across the US from April 15 to July 31, for 2012 (red line at the bottom) as well for the most active year (2003) and the last widespread tornado-land drought (1988). Figure courtesy of NOAA.