Summer Is On Hold
So Long To The 80s & 90s
The high at O'Hare nudged to near 90° Wednesday but ended up just shy of it at 89°. A cooler pattern kicks in today and we not only say goodbye to any 90s for several days but also any 80s. The HRRR model has our highs today topping out only in the lower 70s for most of us with just upper 60s along the lakefront. Average highs for today's date are 85°.
It was a warm and muggy Wednesday with dew points well into the 60s. Dew points are the preferred measurement of moisture for meteorologists. Dew points will fall back into the 50s this afternoon and remain at this more comfortable levels through at least Friday.
Winds have shifted off Lake Michigan and will continue to blow off the lake for most of today, tomorrow and our upcoming weekend. That will help bring in cooler air and keeps highs especially cool along the lakefront.
The best chance of rain over the next two days will be late Friday afternoon into Saturday. Only a few spotty lingering showers expected early today with most of your Thursday dry.
A beach hazards statement has been issued for Cook County from 1 pm today through 4 am Friday. Persistent north and northeast winds will whip up waves as big as 3 to 6 feet and generate dangerous rip currents. The beach hazards statement lingers longer in northern Indiana through 7 am Friday.
The National Blend Of Models has highs in the 70s today through Monday. A seasonably warm pattern returns by the middle of next week with highs in the middle to upper 80s expected.
It will feel almost 30° colder today compared to Tuesday for some of us. Highs Tuesday combined with high humidity made it feel like the middle 90s but today's highs along the lakefront will only be in the upper 60s. The temperature anomaly forecast for this afternoon has the Midwest about 10° to 20° below average.
The longer range temperature probability forecasts are still slightly favoring the Chicago area for an above average middle of the month. The 6-10 day forecast has outlooked us for above average temperatures overall from July 13th through July 17th. The longer range 8-14 day forecast also favors us for above average temperatures overall from July 15th through July 21st. Average highs are in the middle 80s for the middle of July.
The even longer range Subseasonal Experiment (SubX) temperature anomaly forecasts doesn't have a very strong signal for the last two weeks of July. The average highs for this period are in the middle 80s. The temperature anomaly forecast for the week ending July 23rd has us outlooked for temperatures slightly above average. It takes a keen eye to see the pixel representing the Chicago area is shaded in light yellow. A stronger signal for a warmer end of the month is found just north of here and out in the western US. The forecast for the following week ending on July 30th also has Chicago outlooked for about average temperatures. We remain between the stronger warm signal north and west of here and a strong cool signal south of Chicago.
July To Become More Active
After 6 straight dry days at O'Hare we picked up a measly trace of an inch of rain on Wednesday. We are now a .76" of rain below average for July and down nearly four inches below average since the start of meteorological spring back on March 1st. I will have an update on our drought when I review the latest US Drought Monitor analysis on Friday.
Here is a recap of our drought status that I posted last Friday:
June really helped turned the tide in terms of rainfall. The period of March through May saw the rainfall deficit grow at O'Hare to nearly 7 inches below average. June ended up seeing 6.78" of rain. The month ended up with 2.68" of rain above average. According the the latest analysis from the US Drought Monitor, our recent rains helped put a slight dent in the drought.
Comparing this week's analysis to last week's shows some improvement. The portions of Illinois in a moderate and severe drought have diminished. The moderate drought (level 1 of 4) area has dropped from 9.18% to 7.55%. The severe drought area (level 2 of 4) has dropped from 3.12% to 2.22%. The extreme drought area (level 3 of 4) is unchanged at .96%.
The good news is there will be several chances for occasional showers and a few thunderstorms starting later Friday through Monday. The GFS model has several potential rounds of rain in the forecast over the next ten days that will offer some hope for help with our ongoing drought. No one day will be a washout but there is the possibility for some locally heavy rain.
The GFS model total rainfall forecast through this Friday morning squeezes out barely any rain today for most of the area with nearly a quarter of an inch to the south of the city.
I ran the model out through the Monday afternoon to include any weekend rainfall. The additional rainfall this week brings the range of rainfall with this forecast to between about three quarters of an inch to nearly to over two inches of rain. The axis of heavier rain includes the city and suburbs south and west of Chicago.
The longer range precipitation probability forecasts is showing the strongest signal we have seen in several weeks for a wetter than average period. The latest 6-10 day forecast has the Chicago area favored for above average precipitation overall from July 13th through July 17th with the highest probabilities over our area. The longer range 8-14 day forecast also has us favored for above average precipitation overall from July 15th through July 21st.
Here is my 7 day forecast:
Today: AM spotty showers south, mostly cloudy, cooler High: 73 (68 lakeside)
Friday: Partly to mostly cloudy Low: 60 High: 76 (72 lakeside)
Saturday: Partly/mostly cloudy, scattered showers Low: 63 High: 76 (cooler lakeside)
Sunday: Mostly cloudy, sct. showers/t-storms Low: 64 High: 75 (cooler lakeside)
Monday: Partly to mostly cloudy, sct. showers/t-storms Low: 66 High: 78
Tuesday: Partly to mostly sunny, sct. shower or t-storm possible Low: 66 High: 83
Wednesday: Partly to mostly sunny, sct. shower or t-storm possible Low: 67 High: 86