temperature

August 21, 2014

Weather Outlook for Fall and Winter in Illinois

The NOAA Climate Prediction Center released their monthly outlook for September and 3-month outlooks for September and beyond. At this time, they are not expecting a repeat of last winter for Illinois.

According to them, the chance of El Niño has decreased to about 65% during the Northern Hemisphere fall and early winter. If it does show up, it is expected to a moderate to weak event. As a result, the impacts on the US and the Midwest will likely be modest at best.

September and FALL

For both September and this fall, there is an equal chance (EC) of above, below, near-average temperature and precipitation (4-panel figure below) for Illinois. The north-central US is not expected to have below-average temperatures, like it has experienced this summer. This may give crops in those areas a better chance of reaching maturity this fall.

It does look like temperatures are expected to stay above-average on the West and East Coast, as well as Alaska. Wetter-than-average conditions are expected to prevail in the southwest US, and expand into the Plains and parts of Iowa and Missouri later in the fall.

WINTER (December-February)

For Illinois, the current forecast is for equal chances of above, below, and near-average temperatures. Or to put it another way, they see no sign of a repeat of last winter. And they are expecting below-average precipitation in Illinois and across the Great Lakes region. It is still early in the year to lock in on this forecast so I would not cancel orders for snow blowers or salt deliveries just yet.

May 16, 2014

First Half of May in Illinois – Warm, Wet, And Then Snow

According to preliminary records, the first half of May was both warmer and wetter than average for many locations in Illinois. The statewide average temperature was 61.2 degrees, about 1.4 degrees above average. Meanwhile, this morning there are reports of snow falling in northern Illinois. Talk about weather extremes. This was after last weekend when we saw widespread reports of highs in the upper 80s and low 90s.

The statewide average precipitation was 2.43 inches, 18 percent above average. Here is a screenshot of the last 14 days showing the widespread and heavy rainfall in much of the northeast, east-central, and southern parts of Illinois with many sites reporting between 3 to 6 inches of rain. Parts of western and central Illinois have not been as wet with amounts in the range of 1 to 3 inches of rain.

Snow in May? Read more on the Chicago NWS page. It looks like Rockford set a new record for the latest report of snowfall in the season. The Chicago record still stands at June 2, 1910.

June 12, 2013

Monthly Temperature and Precipitation Departures Since 2011

Here are the monthly temperature and precipitation departures for the state of Illinois since 2011. Departures are from the long-term average (1981-2010). A few of the outstanding features were:

outstanding warming from July 2011 to July 2012;
a wet start to 2011 and 2013;
drought in 2012, starting in January 2012 and staying in parts of Illinois through at least the end of the year.

Before becoming too complacent about growing conditions this summer, we should remember that we started out with wet conditions in 2011 before a flash drought arrived in July and August. The combination of hot, dry conditions – especially in central Illinois – led to crop losses by the end of August of that year.

May 1, 2013

April 4th Wettest On Record

Precipitation

This April was the 4th wettest on record for Illinois with 6.90 inches, based on the preliminary numbers. That was 3.13 inches above the long-term average of 3.77 inches.
To show you how wet it was, this April easily beat out the combined statewide rainfall totals for Illinois in May, June, and July of 2012 during the worst of the drought. The total rainfall for those months in 2012 were 2.50 inches, 1.80 inches, 1.48 inches, respectively, which led to a total of only 5.78 inches. That was 1.12 inches less than this April!
The first map below shows the spectacular rainfall totals across much of the state. The areas in yellow and orange were 6 to 9 inches. A few areas in pink and red were 9 to 11 inches. This product has a 4 kilometer resolution and is based on radar estimates calibrated with rain gauges.
The second map shows the same rainfall amounts expressed as a percentage of the long-term average. There was a small patch of below-average rainfall in far southern Illinois. Otherwise the rainfall across the rest of the state was much above average. Many areas in the dark blue were 2 to 3 times their long-average rainfall.
Speaking of rain gauges, the two largest monthly totals for April so far were Augusta with 12.28 inches and Naperville with 11.03 inches. Several more stations reported totals in the 10-inch range.
There were two major impacts of the wet April. One was widespread flooding on the Illinois, Wabash, and Mississippi Rivers and their tributaries. Several sites along the Illinois reported record high river crests in April. Because the flooding included the Chicago area, the dollar damages and number of people affected will be quite large.
The second impact of the wet April was the delay in fieldwork. In the April 29 USDA NASS report, only 1 percent of the corn crop was planted, compared to 76 percent last April, and a five-year average of 36 percent.

The statewide average temperature was 50.1 degrees and 2.3 degrees below average. That was not record-setting but reflects the fact that we had a lot of cool, cloudy days in April.

Figures

The April 2013 precipitation, ending with reports on the morning of May 1. Click to enlarge. — April 2013 precipitation, ending with reports on the morning of May 1. Click to enlarge.

April precipitation, expressed as a percent of the long-term average. Click to enlarge. — April precipitation, expressed as a percent of the long-term average, for reports ending on the morning of May 1. Click to enlarge.