Recent Tornadoes A Good Reminder
Have A Plan Before The Next Storm Strikes
We had almost made it through June without a tornado north of I-74 in Illinois. Then the first confirmed tornadoes for northern Illinois of 2021 hit. We were in the middle of a drought not only from a lack of rainfall but also a drought in terms of severe weather. It may have lulled some of us into a false sense of security. The tornadoes that struck our western suburbs on June 20th were a wake up call.
It's a cliche but it is very apt for this event. It could have been much worse.
The worst tornado of the three that hit on the night of June 20th carved a path just over 16 miles long from Naperville to Willow Springs. The scars it left behind in the form of downed trees and damaged or even destroyed homes indicated this was a "significant" tornado reaching EF-3 intensity. The strongest winds were estimated at 140 mph. Eleven people were injured from this storm.
Just six days later tornado sirens were heard in downtown Chicago. Radar indicated storms capable of producing tornadoes but ultimately the city was spared this past Saturday. Four tornadoes were confirmed Saturday south of the city in a weekend that also saw some flash flooding.
The map above shows all the tornadoes that have occurred in our area between 1950-2017. This map and the recent events of this past week should serve as a reminder to be prepared during severe weather season. NOW is the time to make a safety plan for you and your family if you don't already have one. If you live in Illinois, you live in tornado alley. Our state ranks in the top ten for total number of tornadoes, deaths per 10,000 square miles and number of killer tornadoes. Illinois also experienced "the worst tornado in US history".
In a previous post I mentioned the importance of multiple and redundant ways of receiving weather alerts. Those sources for receiving weather warnings should include a NOAA Weather Radio, emergency alerts from a cell phone and local media. Don't rely solely on a tornado siren. They are meant to warn people who are outside when the storms strike, not insider their homes.
Here is a list of helpful links with information to help you and your family stay safe:
At Least A Big Dent In The Drought
Recent rains have helped at least ease the drought. We are running a surplus for rainfall in June. O'Hare has picked up just over six inches of rain in the past 16 days. June is now running a little over two inches of rain above average. O'Hare is down just under five inches of rain below average since March 1st. The start of meteorological spring is when the first sings of trouble showed up. We ended up 1.25" of rain below average. By the end of April, we were down 4.29" below average since March 1st or the start of meteorological spring. By the end of May we were down 6.99" below average for spring. We only received .01" of rain for the first eleven days of June. On June 11th we hit our low point officially for O'Hare down 8.54" below average. Abundant rain the past couple of weeks has pushed us back above average for the month.
According to the latest analysis from the US Drought Monitor there was no change in the area under a moderate drought but both the severe and extreme drought areas have decreased my more than half. Like last week, 9.8% of the state is still in a moderate drought (level 1 out of 4). The portion of Illinois in a severe drought (level 2 out of 4) has dropped from 6.43% last week to 3.12% this week. The portion of Illinois in an extreme drought (level 3 out of 4) has dropped to .96% this week compared to 2.84% last week.
The GFS model keeps an active pattern going through this week. It suggests the the heaviest rainfall will come Monday and Tuesday with lighter rain in the middle of the week and then more moderate rain for the weekend. Models aren't in agreement about the threat of rain this weekend. My forecasts for July 4th weekend keeps us mainly dry with only a stray shower possible Friday and Saturday.
The GFS model total rainfall forecast through this evening shows a range of rainfall from about a third of an inch to nearly an inch in total. The heavier part of that range is forecast for the city and areas just southwest of the city. Recent rains have left the ground saturated so it won't take much to get some localized flooding. A flash flood watch is in effect until 7 pm Tuesday evening. Today may be the wettest day of the week then we will get a few more dry hours Tuesday and Wednesday. We should be mainly dry for Friday and this weekend.
The GFS model total rainfall forecast through the Friday spits out about an inch to nearly two and a half inches of rain in total.
The European model isn't as generous with rainfall through Friday. It spits out about a half inch to nearly an inch and a half of rainfall in total.
A marginal risk means isolated severe thunderstorms possible that would be limited in duration and/or coverage and/or intensity. The greatest risk from from any severe storms would be damaging winds and large hail.
The long range precipitation probability forecasts has us moving from near normal rainfall to above average during the first part of July. The latest 6-10 day forecast has the Chicago area outlooked for about average precipitation overall from July 3rd through July 7th. The longer range 8-14 day forecast has us favored for above average precipitation overall from July 5th through July 11th.
Very Muggy But No Excessive Heat
The HRRR model has our highs today topping out in the upper 70s. A few spots well south of the city could tag 80° or more. Cloud cover and occasional rain will keep us just a bit below average. Average highs for today's date are 84°.
Dew points remain high for the next several days. Dew points are the preferred measurement of moisture for meteorologists. They should well stay in the upper 60s to lower 70s. This abundant moisture will continue to provide the fuel for our showers and thunderstorms.
After upper 70s today it looks like we should warm into the lower 80s on Tuesday.
The National Blend Of Models has highs around average (84°) for the next few days then cooling off for Friday and the weekend before heat builds back next week.
The long range temperature probability forecasts move us from a cooler to a warmer pattern for the first part of July. The 6-10 day forecast has outlooked us for below average temperatures overall from July 3rd through July 7th. The longer range 8-14 day forecast also favors us for above average temperatures overall from July 5th through July 11th.
Here is my 7 day forecast:
Today: Mostly cloudy, periods of showers & t-storms (locally heavy rain possible) High: 78
Tuesday: Mostly, sct. shower/t-storm possible (locally heavy rain possible) Low: 68 High: 82
Wednesday: Mostly, sct. shower/t-storm possible (locally heavy rain possible) Low: 69 High: 82
Thursday: Partly to mostly sunny, sct. shower/t-storm possible Low: 67 High: 80 (cooler lakeside)
Friday: Partly to mostly sunny, stray shower possible Low: 61 High: 74
Saturday: Partly to mostly sunny, stray shower possible Low: 59 High: 79
Sunday: Partly to mostly sunny Low: 63 High: 83