Drought Deepens Slightly
Updated: Jun 12, 2021
Some Details On The Drought
The latest analysis on our drought is in and it shows the area in northern Illinois experiencing a moderate drought has increased slightly. The U.S. Drought Monitor says 8.52% of the state is in a moderate drought. That is an increase of 1.6% compared to last week's analysis. 20.89% of the state is considered "abnormally dry" which is an increase from 16.97% last week. "Abnormally dry" is just one level away from a moderate drought. The amount of Illinois in a severe drought remains unchanged at 4.58%.
O'Hare has picked up just over a half inch of rain in the past two weeks. We are down just over 4 inches below average for rainfall since May 1st and over 8 inches since March 1st. We will soon be heading into July, on average the driest month of the summer.
The HRRR model expects a few isolated showers or thunderstorms to percolate along a lake breeze as we heat up today. These should stay mainly west or southwest of the city. No real relief from the drought expected from these.
The GFS model picks up on these today too but offers the best chance for more numerous showers and thunderstorms on Saturday. There should be about 40% coverage with these. After the weekend the hopes dim for drought relief with just some isolated showers or storms possible on Tuesday and some scattered showers and thunderstorms on Friday.
The latest GFS model total rainfall forecast through this weekend only spits a couple tenths of an inch to about four tenths of an inch. We will welcome any rain but again, this isn't the type of widespread, heavier rain we really need to put a dent in this drought.
I ran the total rainfall forecast out through a week from Sunday. The range of rainfall is from around a quarter of an inch to just over a half inch. This includes Saturday's rain so little additional rain is in the forecast after this weekend.
Our neighbors to the north saw a more significant expansion of their drought compared to us. Just over 34% of Wisconsin is now in a moderate drought, up nearly 10% compared to last week. 5.09% remains in a severe drought.
The Midwest as a region saw the drought deepen and expand. Just over 27% of the region is now in a moderated drought, up nearly 10% compared to last week. The area experiencing a severe drought more than doubled. It is now at 5.94%, up from 2.7% last week.
By far, drought conditions are most dire out west. That region saw at least slight increases at all drought levels. This includes moderate, severe, extreme and exceptional. Lake Mead's water level is at the lowest it has been since the Hoover Dam was built in 1931. More than half of the west is in an extreme drought and over a quarter of the region is in an exceptional drought.
The long range precipitation probability forecasts aren't very encouraging. They suggest our drier than average pattern could continue well into June. The latest 6-10 day forecast has us outlooked for below average precipitation overall from June 16th through June 20th. The longer range 8-14 day forecast continues to favor us for below average precipitation overall from June 18th through June 24th. This would likely deepen our drought in terms of intensity and expand it in terms of area.
Steamy Through Saturday Then Relief
June is now running just over 8° above average. Thursday was the 4th day so far this month with a high of 90° or above. There are more to come with highs expected to top out near 90° through Sunday.
Average highs for today's date are around 79°. The HRRR model pushes highs today to near 90° again away from the lakefront but keeps it cooler (70s) lakeside.
This weather pattern that has brought a build up of heat and humidity has also allowed some pollutants to build up. An air quality alert is in effect until midnight Friday for the city, Cook county and surrounding counties.
The EPA has declared an air pollution action day. The National Weather Service expands on this:
An air pollution action day is declared when weather conditions are such that widespread ozone and or particulate levels are expected to be at or above the unhealthy for sensitive groups category of the air quality index.
Active children and adults especially people with pulmonary or respiratory disease such as asthma should limit prolonged outdoor activity. For more information check out at www.airnow.gov.
The primary pollutant today is ozone. On the air quality index scale we are in the unhealthy for sensitive groups today.
The National Blend Of Models keeps our highs well above average through the weekend. A couple of cooler days that will coincide with lower humidity levels will start us off next week. Then the heat returns as highs build back up to near 90° for Thursday and Friday.
Dew points give meteorologists the best measurement of moisture in the air. The dew points have been in the upper 60s to near 70° the past few days and will remain high through Saturday. A dramatic drop in the dew points begins on Sunday and continues into the middle of next week. So although Sunday will still be hot, it won't feel nearly as sticky as Saturday. Dew points bounce back to more moderate levels by the end of next week.
Warmer Than Average Pattern To Continue
The longer range temperature probability forecasts both have us outlooked for above average temperatures overall. The strongest signal for anomalous warmth remains out west. The 6-10 day forecast has outlooked us for about average temperatures overall from June 16th through June 20th. The longer range 8-14 day forecast favors us for above average temperatures overall from June 18th through June 24th. Average highs for these two periods are in the lower 80s.
The even longer range Subseasonal Experiment (SubX) temperature anomaly forecast keeps us favored to be warmer than average for the end of June and start of 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: Partly to mostly sunny, isolated t-storm possible High: 91 (78 lakeside)
Saturday: Partly/mostly sunny, sct. showers/t-storms Low: 70 High: 88 (cooler lakeside)
Sunday: Mostly sunny, less humid Low: 69 High: 87 (cooler lakeside)
Monday: Mostly sunny Low: 68 High: 86 (cooler lakeside)
Tuesday: Mostly sunny Low: 63 High: 79 (cooler lakeside)
Wednesday: Mostly sunny Low: 58 High: 82 (cooler lakeside)
Thursday: Mostly sunny Low: 71 High: 90