Increased clouds limit temperatures with light rain possible Saturday

 A line of decaying storms will approach the Stateline by mid-day Saturday, bringing the potential for at least some light showers mainly between 11AM and 5PM. The threat for thunder will be near zero, but a few pockets of rain may bring a brief steady shower. Outside of that, light sprinkles will be the primary form of precipitation. Any rain we do see will begin to clear by 5-7PM. The bigger impact the rain will have is on the temperature. We may not quite reach the 80s with the clouds in place during the peak heating hours of the day.

The rain that does fall will not amount to much, with most seeing under a tenth of an inch. Better chances for 0.1-0.2" of rain will be primarily Northwest of Freeport. Some locations in the Stateline may not even see any measurable rain at all. Higher chances for rain and storms may be possible toward the end of next week, following increased heat and humidity.

Meteorological fall across northern Illinois begins with a summer-like sizzle

Pleasant Friday:

Mother nature really delivered this week, treating the Stateline to several comfortable days with afternoon highs settling in the low to mid 80s. We'll wrap up the workweek on a similar note, with skies remaining dry and partly cloudy and temperatures climbing into the low 80s, right around 83 degrees.  

Even better, Friday evening/night plans look weather-friendly. Unlike last week, there are no thunderstorms or rain in the forecast, meaning high school football games across the area should kick off and finish without interruption. The dry and pleasant conditions are also great news for anyone heading downtown for City Market, with comfortable temperatures lingering into the early overnight hours. 

 

Weekend Outlook:

This quiet weather pattern won't disappear entirely over the weekend, but most of us will stay dry. Our next disturbance arrives around or just after midday Saturday, bringing the chance for an isolated shower or two during the afternoon. 

Even so, the better rain chances and moisture will stay north of the Stateline, focused across central and southern Wisconsin. As a result, many location across northern Illinois may end up seeing a few clouds and a sprinkle. Sunday brings a similar setup, though temperatures will be a touch warmer as a ridge of high pressure aloft pushes east across the midsection of the lower 48. This will allow highs to climb into the upper 80s. A pop-up shower or isolated thunderstorm cannot be ruled out, but rain isn't expected to be widespread. If you have outdoor plans, keep an eye on the heat but also the radar. 

Meteorological Fall:

As we turn the calendar from meteorological summer to meteorological fall on September 1st, the weather certainly won't be following suit. In fact, the average high for early September hovers around the 80-degree mark, but temperatures will run well above that mark as an upper-level ridge settles across the Tennessee Valley and the Deep South States. 

That ridge will allow summer-like heat to build into the Stateline at the start of next week, sending highs back near the 90-degree mark.
   
 
 

Tonight's full Sturgeon Moon comes with a bonus: A partial lunar eclipse

Dry & Pleasant:

Despite a cold front sliding through during the late morning hours yesterday, temperatures still managed to climb into the mid 80s. The front itself wasn't particularly strong, but it came through early enough to where the severe potential was shoved to our south and east, leaving us dry and warm.

 

Today will feature a much more comfortable setup as high pressure settles into the region. Dry conditions are expected from start to finish, with a mix of clouds and sun present for our afternoon. The drier air will keep the area's humidity in check, while afternoon highs will top out in the low 80s.  

 

  

August's Full Moon:

Tonight, high pressure will also keep us dry, giving us a great view of August's full moon. Also known as the "Sturgeon Moon", this full moon earned its name from Native American tribes, as late summer was traditionally one of the best times of the year catch Sturgeon in lakes and rivers. With only a few passing clouds and calm winds in the forecast tonight, we should be in for a show when peak illumination occurs at 12:18AM Friday morning. 

Partial Lunar Eclipse:

Tonight's full moon is extra special as it coincides with a partial lunar eclipse. A lunar eclipse occurs when the Earth passes between the Sun and the moon, causing the Earth's shadow to fall across part of the moon's surface. The partial eclipse will begin at 9:33PM, reaching its maximum eclipse at 11:12PM, then ending at 12:51AM Friday. 

Summer-like heat set to return next week

 While much of the region has enjoyed some cooler days and refreshing nights as of late, a more summer-like pattern featuring heat and humidity will return starting this weekend. The upper levels of the atmosphere have been favorable for cooler, more comfortable weather as of late, with a Northwest direction to the flow aloft. This has kept a lot of the typical summertime heat and humidity away from us across the Western United States.

But as that ridge begins to shift East, it will bring a lot of the heat with it. As the jet stream flows North of the Stateline, summertime heat and humidity will build up across the Plains and into the Midwest. This will push temperatures into the upper 80s and near 90 some days next week, beginning Sunday and Monday. Isolated to scattered thunderstorms will be possible each day, with higher confidence on storms along the higher concentration of jet stream winds across the Northern Plains and Upper Great Lakes.

It does appear this pattern will stick with us a bit longer, as the Climate Prediction Center is giving us a 70-80% chance we will see above average temperatures to start the month of September. Average highs for this time of year are closer to the low 80s and upper 70s, so it appears likely we will see more mid to upper 80s if not a couple 90s thrown in there.

High pressure builds back in following Wednesday's cold front

 

8pm Update: Just a few very isolated showers moving across the region as the last few pieces of energy rotate around the upper-level low over the Great Lakes. Skies will clear this evening with a little patchy fog possible early Thursday morning.

A line of thunderstorms continues to develop from Michigan down through east-central Illinois Wednesday afternoon, ahead of a cold front that moved across northern Illinois during the morning. Precipitation chances remain limited locally with the front well to our east, but with still a little moisture around and some instability it isn't completely out of the question that an isolated shower or two may still occur through sunset.

Temperatures have warmed into the low 80s with just a touch of humidity as dew points have reached the low to mid-60s this afternoon. Skies should begin to clear with high pressure settling back in Thursday. Temperatures Wednesday night will sit right around 60 degrees with highs on Thursday warming into the low 80s. Thursday night should be good sleeping weather with lows dipping back into the upper 50s. Friday will remain mostly dry with high pressure still over the Great Lakes, but a return to southerly winds Friday night into Saturday will slowly begin to set the stage for the return of not only a rise in temperatures, but also a climb in humidity and thunderstorm chances across the Midwest through early next week. 

Northern Illinois dodges severe threat as risk shifts south and east

Next Cold Front:

Temperatures are running a bit warmer than they were at this time yesterday. This is largely thanks to a blanket of cloud cover overhead but also a light but warm wind out of the south. Most Stateline locales are waking up roughly 10 to 15 degrees warmer, in the mid to upper 60s. There has also been a slight increase in humidity levels since yesterday as dew point are now sitting in the low 60s.

With the early arrival of our next cold front, there will be a chance for an isolated shower or thunderstorm from now up until about 9-10AM. 

Once the cold front passes, winds at the surface will shift out of the northwest and gradually increase, helping to usher in slightly drier air for the rest of our "hump day". Expect partly cloudy with afternoon highs reaching the low 80s. Occasionally, wind gusts could top out around 20 mph.   

Severe Potential Very Low:

It is also because of the cold front's early arrival that the severe weather threat today is expected to stay well to our south and east, even beyond the Chicago metro area. The Storm Prediction Center has placed portions of eastern Illinois, northern Indiana, and the southernmost areas of Michigan under a level 2 of 5 Slight Risk for scattered strong storms.

Northern Illinois gets one more pleasant day before midweek cold front

Another Pleasant Day:

Once again, the atmosphere is setting up favorably for some patchy fog to develop. Winds remain calm, the moon is shining overhead (meaning mostly clear skies) and temperatures are within 1 or 2 degrees of the dew point, allowing moisture to condense near the ground. The good news is that conditions don't appear to be supportive for widespread dense fog. 

Once any patchy fog lets up, another pleasant late-summer day is in store across the Stateline. The same area of high pressure that brought spectacular weather Sunday and Monday will be parked to our east over the Ohio Valley, keeping conditions quiet with partly cloudy skies. Afternoon temperatures, thanks to a south to southwest wind, will end up a little warmer, pushing into the low 80s. Thankfully, it won't feel humidly warm as dew points should remain around the 60-degree mark. Great weather for Food Truck Tuesday over by the Conservatory. 

Midweek Storm Chances:

At the same time, thunderstorms are expected to develop across northern Wisconsin and portions of northern Minnesota this afternoon. While that activity will be well to the Stateline's northwest initially, forecast models suggest some of those showers and storms could drift southeastward overnight. As a result, we could see a chance for a shower or storm after midnight, with the possibility of a few lingering into the Wednesday's morning commute. 

Thunderstorm chances during the day all depend on the timing of our next cold front. It does seem the front pushes through without any worry, pushing the better environment for thunderstorm development to the south and east of the Stateline. For now, I've kept a chance for a few thunderstorms during the midday and afternoon hours. But again, it wouldn't surprise me if much of the day remained dry. Expect afternoon highs to land in the low 80s. 

 

In their latest round of severe outlooks, the Storm Prediction Center has left the entire Stateline under a non-severe risk with the higher potential along the cold front being south and east of Chicago.