The NWS released their outlooks for the month of July and the 3-month period of July-September.
Illinois and much of the US has an increased chance of warmer-than-normal temperatures for both July and July-September (first column in the figure). Illinois has equal chances of being above, below, and near-normal on rainfall – a virtual coin toss. That is not a surprise on the rainfall. Most of our summertime rain is guided by local conditions and fast-changing weather patterns.
Historical Trends for July
Temperatures: Historically in Illinois, daytime temperatures in July have become milder over time (first graph) while nighttime temperatures have become warmer over time (second graph). While the decreased heating during the day may be welcome, the increased warming at night can be problematic for humans, animals, and plants as they rest. The green line is a smoothed curve to help the eye see the underlying pattern of change from the variability of individual years. Continue reading “Outlook for Summer, Above Normal Temps”
Above-Average Temperatures Expected to Continue through Fall
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. Continue reading “Above-Average Temperatures Expected to Continue through Fall”
Outlook for March, Spring, and Summer
The National Weather Service just released their outlook for March and spring. We have moved out of the La Niña pattern in the Pacific pattern to something called ENSO-neutral conditions this spring.That means we are between the El Niño and La Niña phases in the Pacific Ocean. Some of the predictive models are indicating a shift towards a weak El Niño by summer. That is actually good news for Illinois since we have a tendency to experience milder summer temperatures under those situations.
For March, they have Illinois in a region called “EC”, meaning that we have equal chances of being above, below, or near-normal on temperature and precipitation. Sometimes I call “EC” a neutral forecast because it does not lean one way or another.
For March-May, Illinois has an increased chance of above-normal temperatures and northern Illinois has an increased chance of above-normal precipitation.
Continue reading “Outlook for March, Spring, and Summer”
November Trending Warmer, Wetter
Based on historical data for Illinois, the weather in November is trending towards warmer and wetter conditions over time. Based on the latest NWS forecasts, this November is likely to continue that pattern.
Historical Trends
Temperature
The statewide average temperature for November shows a wide variation from year to year – typical of all months in Illinois. However, there is an underlying warming trend of about 2 degrees over the last century.
