All Quiet On The Severe Weather Front
Drought Contributes To Quiet Pattern
There are some positives when it comes to a parched weather pattern. So far, so quiet this year for severe weather. We are nearly in the middle of typically the peak months for severe weather but so far have been spared. May, June, July and August on average see the most severe reports, including flash flooding.
The only day on which severe weather was reported in northern Illinois was April 29. Typically, our area sees 9 days of severe weather or flash flooding by June 1.
No severe weather or flash flooding was reported during the entire month of May, which was the first time this has happened since 2002 and only the 14th time since 1950 (the year that National Weather Service storm report records date back to).
Chicago O'Hare has only reported thunder two times so far this year. Normally, thunder is reported on about 45 days per year.
NWS Chicago has issued 2 Severe Thunderstorm and 0 Tornado warnings so far this year, which is amongst the lowest totals across all 122 NWS forecast offices in the U.S..
The lack of dots in northern Illinois on the map below tells the same story. There have only been a few severe weather reports north of Champaign so far this year. The bulk of severe weather reports are well south of the city, including 18 reports of tornadoes downstate.
The darker the blue on the map below, the fewer the reports of severe weather. Most of the severe weather so far in 2021 has been in the southern plains and Gulf coast regions.
June Coming In Hot
We are coming off of the warmest weekend since late last August. June is feeling more like July and is now running more than 7° above average. More cloud cover along with some scattered showers and thunderstorms today will cool us off a bit compared to the past few days. We will still be 5° to almost 10° above average. Highs today should top out in the lower to middle 80s.
Humidity levels will be higher through the week. Dew points bumped up into the 60s on Sunday and should continue to make it feel more muggy today, Tuesday and beyond.
A wind will turn in off the lake on Tuesday and keep us cooler lakeside the next several days. Our best chance for some scattered showers and a few isolated thunderstorms will be during the afternoon and evening hours today through Thursday. It won't be a washout but there could be a few spots that get soaked with some locally heavy rain.
The meteogram below considers several different model forecasts of temperatures. We will generally warm up slowly but surely this week and peak on Friday with highs near 90°.
The temperature anomaly forecast for Friday shows the greatest amount of anomalous warmth stretching from here southward to northern Texas. Temperatures may be as warm as 8° to almost 15° above average.
Some Drought Relief This Week
I updated the status of our drought on Friday. Here is a recap:
We are approaching the driest month of summer just as our drought deepens further. July on average sees 3.71" of rain making it the driest month of summer but June is starting off dry and the longer range outlooks for this month aren't particularly encouraging. I discuss this further below.
We have gone nearly eight weeks with less than two inches of rain. We just came out of the 3rd driest May on record. O'Hare is now down 7.83" of rain below average since March 1st, the start of spring.
The latest analysis from the U.S. Drought Monitor shows the area experiencing a severe drought has expanded by 62% compared to last week. Last week 2.85% of northern Illinois was in that category of drought and now it stands at 4.58%. Portions of DuPage & Cook counties, northern Kane county, all of Lake county and of McHenry county are now in a severe drought. There was a slight increase from 6.58% of the area experiencing a moderate drought last week to 6.92% this week.
The most parched portions of our area have seen between 25% to 50% of average rainfall over the past sixty days (ending on June 3rd).
Some scattered showers and thunderstorms are likely the next few days. Afternoon and evening hours have the highest chance to see some much needed rain. Expect about 40% to 60% coverage today through Thursday. The GFS model squeezes out the most rain today and tomorrow here.
The GFS model total rainfall forecast through next Friday afternoon holds out hope for some drought relief. The range of rainfall varies from nearly a third of an inch to more than an inch in total. It won't quench the drought but anything will help at this point.
This week might be our best shot at some appreciable rain for a while. The long range precipitation probability forecasts favor us for moving into a dry pattern during the middle of the month and just beyond. The latest 6-10 day forecast has us outlooked for below average precipitation overall from June 12th through June 16th. The longer range 8-14 day forecast continues to favor us for below average precipitation overall from June 14th through June 20th. This would mean both an expansion and deepening of our drought starting this weekend and continuing into next week.
Warmth Doesn't Wane Much
The last several long range temperature probability forecasts have consistently shown a strong signal for a warmer middle part of this month. The strongest warm signal has now shifted a bit further west of Chicago so our probabilities have dropped a bit but we are still favored for above average temperatures overall. The 6-10 day forecast has outlooked us for above average temperatures overall from June 12th through June 16th with probabilities between 40% and 50%. The longer range 8-14 day forecast continues to keeps us above average overall from June 14th through June 20th with probabilities slipping here too.
The even longer range Subseasonal Experiment (SubX) temperature anomaly forecast keeps the above average temperature pattern coming into early July. The average highs for this period are in the lower 80s. The temperature anomaly forecast for the week ending June 25th has us outlooked for above average temperatures overall but on the lower end of the spectrum. The forecast for the following week ending on July 2nd also has Chicago outlooked for above average temperatures overall with a stronger signal.
Here is my 7 day forecast:
Today: Mostly cloudy, sct. showers & t-storms High: 84
Tuesday: Partly/mostly cloudy, sct. showers & t-storms Low: 68 High: 83 (78 lakeside)
Wednesday: Partly/mostly cloudy, sct. showers & t-storms Low: 68 High: 82 (cooler lakeside)
Thursday: Partly/mostly cloudy, sct. showers & t-storms Low: 67 High: 84 (cooler lakeside)
Friday: Partly to mostly sunny Low: 68 High: 89 (cooler lakeside)
Saturday: Mostly sunny Low: 67 High: 86
Sunday: Partly to mostly sunny Low: 64 High: 83 (cooler lakeside)