Scattered thunderstorms this weekend, less humid next week

 While our rain and thunderstorm chances will remain slim for the 4th of July festivities, coverage of showers and storms will be a bit higher into the weekend. A developing low pressure system will swing a cold front closer to the area between Saturday and Sunday, bringing scattered storms with it. Highest coverage looks to begin Saturday evening, mainly after 6PM.

Scattered showers and storms will remain possible into Sunday morning, with highest coverage most likely Sunday morning and early afternoon as the cold front swings through. Gradually, the afternoon and evening will bring drier air behind the cold front, ending precipitation and keeping us dry into Monday.

Ahead of the front, Saturday will remain hot and humid with highs in the low 90s again. By Sunday, highs in the mid-80s will be a little cooler as the front slides in. Sunday night will begin the drop in humidity, as dew points return to the low 60s again.

Much of next week will feature a typical summer-time pattern with a large ridge of high pressure over the Southwestern United States, keeping the worst of the heat and humidity away from us locally in the Midwest. This keeps us milder and closer to average, with highs likely in the mid-80s. A few weak waves will pass over and around that ridge of high pressure going into the middle of the week, bringing us scattered chances for storms Tuesday through at least Thursday.

Isolated thunderstorms developing Thursday evening; Few showers possible early Friday

 For the 12th time this season the high temperature in Rockford has reached 90 degrees, or higher, with the high on Wednesday topping out at 92. Thankfully, the humidity hasn't been excessive as dew point temperatures have remained in the low 60s.

Temperatures will be slow to fall through the evening as a warmer - and slightly more humid - air mass slips into northern Illinois and southern Wisconsin. This will hold temperatures in the upper 60s, to right around 70 degrees at the start of Friday.

Locally, skies have been very quiet with regards to showers and thunderstorms. But over the last hour isolated thunderstorms have developed in eastern Iowa and are slowly moving to the east. A few isolated storms may be possible in northwest Illinois between 7pm and 9pm, however, they should be on a weakening trend as they near the Stateline.

The focus will then shift to the northwest where a remnant low pressure system is currently moving through Upper Midwest. This will ride along a stalled frontal boundary in Wisconsin late Thursday night, with thunderstorms likely redeveloping as higher moisture moves in from Iowa. These showers and isolated thunderstorms will sink south along the boundary into southern and southeast Wisconsin, and perhaps even parts of northern Illinois early Friday. Again, they should be in a weakening phase, but the stronger showers/storms may be capable of gusty winds. This will be especially true in southern Wisconsin.

Humidity will be on the rise Friday morning as dew point temperatures increase thanks to the incoming rain, but should lower some during the afternoon as drier air moves in. However, with very little to stop air from rising - such as a cap - during the afternoon any outflow boundary from the morning activity could help fire off a very isolated shower/storm. This would be highest in the early afternoon. After that, dry conditions are then expected through the evening which shouldn't cause any issues for the fireworks displays that'll be taking place.

It'll remain humid through the evening with temperatures still in the low 90s around 5pm as the parade in Rockford is set to begin. Temperatures will be in the mid and upper 80s around 9:30pm under a partly cloudy sky.

Hot few days ahead, heat indices to approach 100° on the 4th

A secondary wave pushing in from the northwest will provide us with another opportunity for hit-or-miss showers and storms today. Like Wednesday, a good portion of the Stateline is under a level 1 Marginal Risk for severe weather, mainly for damaging winds up to 60 mph and heavy downpours. 

Most of the day will stay dry, though it will be rather important to keep an eye on the radar as we approach the evening hours. Temperature-wise, partial sunshine and a light southwest wind will push temperatures into the low 90s for the second straight day and the 12th time this year. If you are out and about during the afternoon and evening, you may notice humidity levels are a touch higher. Dew point temperatures will end up around the mid 60s, pushing heat indices into the low 90s at times. 

The dangerous heat and humidity isn't scheduled to arrive until, perfect timing, the 4th of July. And as you can see, Rockford has dealt with plenty of heat on the 4th over the last 5 years, 3 of which have ended up with highs in the low 90s.

In fact, tomorrow will be just as warm as the 4th in 2020 and just as dry, though an isolated shower or storm cannot be ruled out. It seems the best potential for organized and even severe storms will be to our northwest during the daylight hours. With heat indices ending up near the 100° mark, be sure to practice heat safety while enjoying Independence Day festivities. That includes wearing light colored clothing, taking frequent breaks in the shade and air conditioning, and of course remaining hydrated.

Summer heat and thunder chances continue through the weekend

Temperatures Wednesday afternoon warmed into the upper 80s, with a few locations reaching 90 degrees - including Rockford. This is the 11th time that Rockford's high temperature has reached 90 degrees, or above.

Skies were quick to turn partly cloudy allowing a few thunderstorms to develop north of the state line. Isolated strong to severe storms continue further north near Green Bay, moving out over Lake Michigan. But further south the activity has remained rather isolated and localized.

While we may still see a very isolated shower develop within the next couple of hours, most should remain dry through the night. Winds will turn light once again with overnight lows dipping into the mid-60s.

There remains a slightly better chance (although still isolated) Thursday for a few showers and thunderstorms as a weak boundary slips into southern and southeast Wisconsin. This will combine with a little more moisture during the afternoon as temperatures warm back near 90 degrees. The Storm Prediction Center continues to highlight southern Wisconsin and northern Illinois under a 'marginal' risk for an isolated strong/severe storm or two, with strong wind gusts and hail being the primary threats (if storms develop).

The lingering boundary Thursday night will likely keep some cloud cover around throughout the night and into Friday, along with a small chance for a shower or two Friday morning. Upper-level ridging will then build in Friday pushing afternoon temperatures into the low 90s. But unlike days when the heat builds and we develop a cap on our atmosphere, that won't be the case Friday. While there isn't much aloft to allow and thunderstorms to develop, should we see anything Friday morning those leftover boundaries may be just enough to allow a storm or two to 'pop' during the afternoon and early evening. The best chance for that appears to be more northeast, but something we'll keep an eye on over the next couple of days.

Temperatures through the start of the weekend will climb with highs rising back into the low 90s Friday and Saturday, although the heat index won't be as high as it was during the hot stretch back in June (the 21st-23rd). Peak index values will likely range between 95-100 degrees. Still, with plenty of activities taking place this weekend just remember to take it easy out in the heat.

Isolated storm chances ahead of a hot and humid 4th of July

Several ridge-riding disturbances will tag along with the increasing heat, bringing isolated storm chances ahead of the 4th of July holiday.

Keyword being isolated, meaning areas like Dixon or Lena or even Beloit could see a shower or storm while the rest of the area remains rain free. Those that do wind up getting in on today and tomorrow's isolated storm threat, winds up to 60 mph and heavy downpours will be the primary concerns. 

Once this ridge is overhead, the favored storm track will be pushed to the north. This will leave us hot and fairly dry for Independence Day, though an isolated thunderstorm cannot be ruled out. 

High temperatures look to touch the 90° mark on Thursday, then surge into the low 90s for the 4th and for the start of the weekend. With dew points near the 70° mark, expect heat index values to wind up in the mid to upper 90s both days. That's why if you have any holiday festivities or if you are planning to attend the parade, have plenty of water on hand and find a nice shady spot. It's not until Sunday where we see our next cold front slide through, pushing highs back into the 80s for early next week.

Isolated thunderstorm chances return Wednesday and Thursday

 
Widespread rainfall has been in short supply the last couple of weeks as summer-time thunderstorm coverage becomes more isolated. The last time Rockford recorded rainfall over an inch was back on the 18th of June when 1.77 inches fell. Since then, rainfall totals have been less than two tenths of an inch (at least at the airport). Isolated thunderstorms over the last week have locally produced heavy rain, but that rain has not been widespread.

As we wrap up the month of June and look ahead into the month of July temperatures will continue to warm - rising into the upper 80s and low 90s. Overall, June was a warm month with the average monthly temperature (highs and lows combined) reaching just over 73 degrees. This was three degrees *above* our monthly average. Unfortunately, precipitation ended up below average with only 3.38 inches being recorded - which was 1.85 inches *below* average.

While moderate drought conditions remain for many throughout northern Illinois, the last few weeks have provided at least some improvement with the localized heavy rainfall. The latest drought monitor continues to show some areas still dealing with moderate drought conditions across northern Illinois.

Isolated thunderstorm chances return Wednesday and Thursday just before the heat this holiday weekend. High pressure sliding to our south tonight will work to turn winds to the southwest Wednesday, warming afternoon temperatures back close to 90. Dew points, however, should remain in check which should limit the overall humid feel during the afternoon.

Jet stream winds aloft will move in from the northwest allowing a few upper-level disturbances to slide through the Midwest and western Great Lakes. These disturbances, when paired with the heating of the day, will allow for the chance of an isolated storm or two to develop during the afternoon and evening. Thursday we may see a slightly better chance with a little more moisture present in the atmosphere. If we do see isolated thunderstorms there remains a chance that a storm or two could reach severe limits, posing a risk for strong winds and/or hail. 

 

July begins on a sun-filled, seasonable, and comfortable note

June Recap:

Wow. I feel like it was just yesterday we were talking about June's climatology. Now, June is in the books. It was a warm one for sure as our average high came in roughly 4° over. It didn't help that we had eight 90° days from the 15th to the 30th. Rainfall-wise, rather disappointing. Yes, we managed to observe roughly 3.4". However, that is considered below average. In fact, Rockford hasn't seen an above-average June in the rainfall department since 2018. 

Tuesday's Forecast:

July begins where June left off, dry. However, today is going to be one of the more enjoyable days of the last week or two. With an area of high pressure sitting over the central plains, surface flow this afternoon will be out of the northwest.  This will leave us seasonable with highs in the mid 80s and with dew points near the 60° mark. Today would be that perfect day to take work outside or to attend this week's edition of Food Truck Tuesday. 

Rising Temperatures:

Though our temperatures will rise as we approach the 4th of July, humidity remains comfortable. 

 Highs will reach the upper 80s Wednesday and Thursday under a partly cloudy sky. As far as rain chances is concerned, a sprinkle or shower is possible at any point during the daylight hours. Thursday's rain chances seems to be tied more to a lake breeze boundary that comes off of Lake Michigan. Chances will be best closer to the lake, though the further this boundary pushes inland, the higher our chance is for an isolated shower. 

4th Sneak Peek:

As of this morning, rain chances look to remain low and isolated for the 4th. But with the ridge overhead, it will be a hot and humid day with highs likely in the low 90s and dew points pushing 70° or more.