The NWS released their latest forecasts for May and beyond. Currently, the Pacific Ocean is in the neutral phase between La Niña and El Niño. There is much debate on if and when El Niño should return. It could happen in late summer. Meanwhile, the theme running through the outlooks is the increased risk of above-average temperatures through the fall. Illinois has been running warmer than average in the last few years. In 2016, 10 out of 12 months were above-average. So far, every month in 2017 has been above-average.
- January 2017: 5.7 degrees above average
- February 2017: 10.1 degrees above average
- March 2017: 1.9 degrees above average
- April 1-19, 2017: 6.5 degrees above average
May: eastern portions of Illinois have a slightly increased chance of being warmer than average. I am going out a little farther on the limb and say that all of Illinois has an increased chance of being warmer than average, based on recent trends and the climate models. Meanwhile, most of Illinois and the Great Lakes are expected to have an increased chance of below-average precipitation. Click to enlarge maps.
May-July: all of Illinois and most of the US have an increased chance of above-average temperatures. The Great Lakes region, including northern Illinois, has an increased chance of below-average precipitation.
August-October: the United States has an increased chance of above-average temperatures this fall, while all of Illinois and the Midwest has equal chances (EC) of above-, below-, and near-average precipitation.