Drought, Dangerous Heat & Strong Storms
Thursday's high of 87° was the warmest we have seen in about a week. We will actually cool down a few degrees today compared to that because of more cloud cover and some scattered showers and thunderstorms. We warm right back up again over the weekend and flirt with dangerous heat index values early next week.
The GFS model has our highs today in the lower 80s. The average high for this date is 84°.
It will be a smidge more muggy today but the humidity levels will soar into the 70s by Sunday to set us up for a very steamy start to next week. The heat index or apparent temperature values by Monday may be approaching 100°. Tuesday will feel tropical too with similar heat index values.
Our transition to that dangerous heat from the relatively comfortable past few days continues today and tomorrow. Dew points climb into the middle 60s today and upper 60s to near 70° on Saturday.
Gusty southwest winds today continue to transport very moist air from the Gulf Coast towards Chicago.
The increasing heat and humidity means any showers or thunderstorms that form the next few days will be capable of producing some torrential downpours.
Our dew points should stay in the 70s or at least very close to 70° through Thursday. Next week may be the muggiest week we have seen this year so far.
As I like to point out, dew points are the preferred measurement of moisture in the air for meteorologists like me. The dew points Sunday through Thursday will be in the "uncomfortable" to "sweltering" category.
The National Blend Of Models has highs holding above average from Saturday through Thursday next week. We cool back to right around average for the end of the week and following weekend.
The haze from wildfire smoke may not be as noticeable today. The HRRR Model vertically integrated smoke forecast still suggests wildfire smoke from western fires will be in our skies on this Friday but the concentrations have diminished compared to the past few days.
Here are some articles related to wildfire smoke that you may be interested in:
The Midwest along with most of the country is favored for above average temperatures overall for the middle of this month. The 6-10 day forecast has outlooked Chicago for above average temperatures from August 11th through August 15th. The longer range 8-14 day forecast continues to favor us for above average temperatures overall from August 13th through August 19th. Average highs are in the lower to middle 80s for the start to August.
The Good & Bad From Latest Drought Analysis
Mostly good news from the latest US Drought Monitor analysis. The good news is that portions of Illinois in a moderate and severe drought have dropped slightly. 6% of the state is now in a moderate drought (level 1 out of 4 levels) down from 7.17% last week. 2.1% of the state is now in a severe drought (level 2 out of 4 levels) down from 2.31% last week. Northern Illinois is the only part of the state reporting drought conditions. The bad news is the portion of the state considered "abnormally dry" has increased to 10.99% from 9.74% last week.
Yesterday was the 7th straight day without any measurable rainfall. July ended up 1.81" of rain and August is running nearly three quarters of an inch below average.
The 7-day period ending on Wednesday morning shows a large portion of our area is parched. Just 10% to 25% of average rainfall has been reported for much of the Chicagoland area during this period.
The latest GFS model has some scattered showers and thunderstorms possible at times today and through the weekend. Another round of rain is forecast for later Monday. After this more active period the chance for rain drops dramatically all the way through the following weekend.
Some of the storms late tonight into early Saturday may be strong to severe. I'm also watching for another window later this weekend with the potential for severe weather. Sunday night into early Monday warning may be a bit noisy too.
The Storm Prediction Center has us in a marginal risk for severe storms tonight. The biggest threat would be damaging winds and large hail.
Models have been oscillating back and forth with rainfall amounts. I ran the GFS model total rainfall forecast through Monday morning and the latest range of rainfall forecast for northern Illinois is from as little as just over an inch to as much as nearly four inches. These numbers seem a little high and a bit broad-brushed. There will probably be some locally heavy amounts of rain with all the moisture present this weekend for storms to tap into but I don't think it will be this widespread.
The Midwest region's drought news this week was discouraging overall. The good news is the area in a moderate drought fell from 27.33% to 26.26%. The area in a severe drought increased to 17.59% from last week's 16.74%. The area in an extreme drought nearly doubled to 6.72%, up from 3.73% last week.
The drought numbers for the west continue to stagger me. The area in the highest levels of drought (extreme and exceptional) diminished slightly but the area in the lower levels of drought (moderate and severe) increased at least slightly. Nearly two-thirds of the region is in an extreme drought and about a quarter of it is in an exceptional drought.
We need to squeeze out of drop of rain from the more active pattern we will be in today through early next week. The long range rainfall forecasts suggest a drier pattern is coming. The latest 6-10 day forecast has the Chicago area favored for about average precipitation overall from August 11th through August 15th with the northwest corner of our state favored for below average rainfall. The longer range 8-14 day forecast has all of northern Illinois outlooked for below average precipitation from August 13th through August 19th.
Here is my 7 day forecast:
Today: Partly to mostly cloudy, sct. showers/t-storms, breezy High: 83
Saturday: Partly to mostly sunny, sct. shower/t-storm possible Low: 69 High: 87
Sunday: Partly to mostly sunny, sct. showers/t-storms mainly late Low: 69 High: 89
Monday: Partly to mostly cloudy, sct. showers/t-storms Low: 72 High: 87
Tuesday: Partly to mostly sunny, sct. shower/t-storm possible Low: 73 High: 92
Wednesday: Partly to mostly sunny, sct. shower/t-storm possible Low: 74 High: 89
Thursday: Partly to mostly sunny, sct. shower/t-storm possible Low: 67 High: 83