Check the weather radar map above – triggered by a warm front, a wide band of showers – possibly including a few isolated thunderstorms will spread east into northeast Illinois, southeast Wisconsin and northwest Indiana this evening with rain continuing off and on across the Chicago area much of the overnight hours.
Late this afternoon the warm front was located over eastern Nebraska across northern Missouri into southern Illinois. That front will slowly move east across Iowa tonight – at the same time slowly lifting north – probably moving through the Chicago area Thursday morning. Clouds will gradually increase and lower this evening, while winds shift from northeast to east and finally southeast late tonight. Initially this evening dew-points will be in the 20s, and rain falling from the clouds into the dry air will evaporate, but eventually the air will moisten enough for the rain to reach the ground.
By Meteorologist Tom Skilling
Chicago temperatures this meteorological spring—the three month period from March 1 to May 31—have extended this past winter’s trend of cooler than normal temperatures. With the season more than half over, 60% of its days have posted temperature deficits.
The one way spring differs from this past winter is that it’s been dry.
The season ranks driest of any spring to date over the past 17 years! Its 2.99” observed precipitation (this includes rain and melted snow) is just 60% normal and down nearly 2 inches.
It’s a trend not limited to Chicago’s official observation station at O’Hare. Our analysis of precip tallies at Chicago area observation sites shows the same trend.
Surging temps Thursday and Friday belie the chill and strengthening winds due to take up residence over the coming weekend and spill over into next week
The chilly temperatures which dominated Wednesday are to ease Thursday—and even more so Friday—as the current easterly wind regime off Lake Michigan gives way to more southerly Thursday afternoon and evening winds. That southerly flow is to transport Gulf moisture into the area providing fuel for shower and thunderstorm development Thursday afternoon into Thursday night.
I believe this was among the coldest winters on record, and since Jan.1 this seems like one of the coldest starts to a calendar year in my memory.
— D. Baxter, Chicago
Most area residents would agree with you. The winter (December through February) just ended ranks as Chicago’s fourth coldest. That’s the result of a computer scan of 144 winters in Chicago’s official temperature database (from the winter of 1870-71 through 2013-14).
With an average temperature of 18.8 degrees, it was 0.5 degrees warmer than the 18.3-degree average of the coldest winter, 1903-04.
And last winter’s chill has persisted into the spring. Through April 21, the average temperature for 2014 stands at 26.6 degrees, the city’s seventh coldest for that period (Jan. 1-April 21). Coldest: 1875 at 25.0 degrees.
Our cold winter has spilled over into a cool start to spring. The overall cooler weather pattern has kept the tornado season relatively quiet. There have been only 21 preliminary reports of tornadoes of EF1 strength or stronger through April 21st. The Storm Prediction Center says that is the lowest number in over 60 years (see bar graph below). Ironically, this news was announced on the same day we noted the anniversary of the worst tornado disaster for Northern Illinois. On April 21st, 1967 at least 10 tornadoes touched down killing 58 people and injuring more than a 1000.
There has been a total of 108 preliminary reports of tornadoes so far this year, far below the previous three-year average of 542 through April. The longer term average is about 260. For April alone there has been just 38 preliminary reports of tornadoes compared to the previous three-year average of 350. That number is inflated by the record 758 tornado reports in April of 2011.
The best news of all is that no one has been killed in the United States so far this year from a tornado. The last time we made it this far into the year without a single tornado death was 1915.
So far, Illinois leads the nation with 18 preliminary reports of tornadoes followed by 15 in Missouri and 9 in California. Oklahoma has only 1 report of a tornado so far this year. The cooler weather pattern that is in part responsible for the quiet start to tornado season will probably continue for at least a few more weeks. The 6 to 10 day forecast from the Climate Prediction Center has the midwest and most of the eastern two-thirds of the country outlooked for cooler than average temperatures. The 8 to 14 day forecast keeps us cooler than average into the first week of May. Recent research suggest that a “curvy” jet stream pattern could contribute to more extreme winter weather like we just experienced. The wavier pattern would result in warmer than average weather out west and colder than average weather here and eastward.