Summer Hiatus Almost Over
One More Relatively Cooler Day
If you are a fan of fall-like weather in summer, enjoy today. The combination of cooler air (lows this morning dipped into the lower 50s in a few spots) and low dew points have made it feel more like October than June. Our somewhat brief break from a rather warm June will continue on this Wednesday but heat and humidity build back quickly tomorrow. June is running nearly 8° above average.
The HRRR model holds highs for the second straight day in the upper 70s for most areas. Highs may tag 80° well west of the city and only reach the lower 70s right along the lakefront. Average highs for today's date are around 81°.
Wall to wall sunshine today so don't forget to slap on some sunscreen. The UV Index is at 9 again today. That is in the "very high" range.
Things to keep in mind with this UV index:
Protection against sun damage is needed. If you need to be outside during midday hours between 10 a.m. and 4 p.m., take steps to reduce sun exposure. A shirt, hat and sunscreen are a must, and be sure you seek shade. Beachgoers should know that white sand and other bright surfaces reflect UV and can double UV exposure.
The dew points will drop into the upper 30s and lower 40s late today. Dew points give meteorologists the best measurement of moisture in the air. They were at tropical levels on Saturday when they reached to near 70°. This morning felt almost 50° cooler than Saturday afternoon. Both temperatures and dew points build back to more typical summer levels by Thursday afternoon.
The National Blend Of Models suggests 70s for highs today at O'Hare for the second day in a row. We may hit 90° or more both Thursday and Friday. The weekend looks warm but not as hot as this past weekend. We slide back into the 70s early next week and then return to just above average by the middle of the week.
Drought Relief Around The Corner?
It still looks likely that at least some scattered showers and thunderstorms will arrive here Thursday night and continue into Saturday. We still need all the rainfall we can get with July, our driest summer month on average, less than two weeks away. O'Hare is now down about a .61" below average for rainfall in June and down 8.60" since March 1st. I'll have the latest drought analysis from the US Drought Monitor on Friday.
Here is a short recap of my drought update (before Saturday's rain) from last week:
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%.
The GFS model suggests the next best chance for rain starting Thursday night and continuing into early Friday. There may be some locally heavy rain with this event. After that, there are chances for rain later Sunday into Monday and next Wednesday through Friday.
The latest GFS model total rainfall forecast through Friday afternoon shows a range of rainfall here from as little as around a third of an inch well south and west of the city to nearly three inches well west and northwest of Chicago. If this verifies, some of the most parched parts of northern Illinois will get some substantial rain.
The long range precipitation probability forecasts still offer at least slight hope for help with the drought. The latest 6-10 day forecast has us outlooked for above average precipitation overall from June 21st through June 25th. The longer range 8-14 day forecast also favors us for above average precipitation overall from June 23rd through June 29th. The model signal isn't particularly strong but it is headed in the right direction.
June May End Relatively Cool
The longer range temperature probability forecasts are again both favoring us for cooler than average temperatures. The model signal is fairly strong. The 6-10 day forecast has outlooked us for below average temperatures overall from June 21st through June 25th. The longer range 8-14 day forecast also favors us for below average temperatures overall from June 23rd through June 29th. Average highs for late June are in the lower to middle 80s.
The even longer range Subseasonal Experiment (SubX) temperature anomaly forecast contradicts these forecasts a bit. It favors us for a warmer than average end to June and start to July. The average highs for this period are in the lower to middle 80s. The temperature anomaly forecast for the week ending July 2nd has us outlooked for above average temperatures overall. The forecast for the following week ending on July 9th also has Chicago outlooked for above average temperatures overall too.
Here is my 7 day forecast:
Today: Sunny skies, mild & pleasant, a bit breezy High: 79 (72 lakeside)
Thursday: Partly to mostly sunny Low: 59 High: 90
Friday: Partly/mostly cloudy, sct. showers/t-storms Low: 70 High: 91
Saturday: Mostly sunny Low: 66 High: 83 (cooler lakeside)
Sunday: Partly to mostly sunny, sct. shower/t-storm late? Low: 61 High: 87 (cooler lakeside)
Monday: Partly/mostly cloudy, sct. showers/t-storms Low: 66 High: 81
Tuesday: Mostly sunny Low: 57 High: 77 (cooler lakeside)