Scattered storms could delay Friday night football games

[4:15PM] Our lone severe storm stretches across portions of Whiteside and Lee Counties, just North of Sterling. This storm is capable of producing 60 mph wind gusts and quarter sized hail as it moves Southeast at around 15-20 mph. This storm will pass over Dixon soon. Take shelter if you are ahead of this storm!

[3:45PM] A new severe thunderstorm warning has been issued for Winnebago and Boone Counties until 4:45PM. This storm is capable of producing 60 mph wind gusts and quarter sized hail as it moves to the East at 25 mph. There is frequent lightning on the West side of this cell, too. Take shelter if you are near this storm!

[3PM] With the main wave of storms still developing to our Northwest along a cold front, a severe thunderstorm watch has been issued for the entire Stateline until 10PM. Strongest storms will be capable of damaging wind gusts, large hail, and frequent lightning. An isolated tornado may also be possible. Main timing of storms is still expected between 5-9PM for local Stateline Counties.

[2:20PM] A severe thunderstorm warning has been issued for portions of Boone, McHenry, and DeKalb Counties until 3PM. This storm is capable of producing 60 mph wind gusts and ping pong ball sized hail as it moves to the Southeast at 25 mph. Heavy rainfall and frequent lightning is also possible.

For those heading out tonight for the first week of high school football, be prepared for some lightning delays and scattered storms. The wave of storms moving through this afternoon (radar as of 2PM) is sub-severe but may be producing 40 mph winds and small hail over Southern Boone County.

The main wave is Northwest along a cold front and will arrive after 5PM. Our main window of storms is 5-9PM. The primary concerns within strongest storms will be lightning, damaging wind gusts, and heavy rainfall.

Pockets of large hail and an isolated tornado cannot be ruled out, either. Once storms clear to the Southeast after 9PM, we will be drying out for the night. Temperatures will drop from the mid-70s by the time games are scheduled to start to around 70 by 9PM.

Severe storms possible today, sunshine returns for weekend fairgoers

Friday's Severe Potential:

Overnight, the Storm Prediction Center upgraded the entire Stateline to a level 2 of 5 Slight Risk for severe weather this afternoon and evening. 

 

 

Today is one of those days where what happens later will largely depend on how the atmosphere responds to the early round of rain and storms. The first batch is expected to arrive around or shortly after the midday in the form of scattered showers and storms. After that pushes on through, the second wave will enter the western Great Lakes, giving us a another opportunity for not only thunderstorms, but strong to sever storms. Again, the placement and intensity of this round is a bit more uncertain. 

IF enough instability can rebuild, additional storms may develop along an approaching and slow-moving cold front over southern Wisconsin before tracking south and southeast into northern Illinois between 4PM and 5PM. Any storms that become severe will be able to produce damaging winds and large hail, with even the possibility of a tornado or two due to the turning in the atmosphere. I know it's a busy day with fairs, football games, and outdoor plans, but make sure you have multiple ways to get severe alerts should severe storms develop. 
 

Winnebago County Fair:

Speaking of the Winnebago County Fair, the weather for the rest of the weekend is looking solid. Saturday should remain dry, with a light northwest wind and afternoon highs in the low 80s. While a stray shower or storm can't be completely ruled out, most locations will stay rain-free. Sunday looks even better, with plenty of sun and highs in the upper 70s. 

Isolated storm chances return Friday ahead of cold front

 

After a little bit of a humid Wednesday, Thursday has turned into a spectacular afternoon! After a very comfortable start and temperatures falling into the mid-50s afternoon highs reached the upper 70s, to right around 80 degrees. We are beginning to see a few upper-level clouds move in as showers develop well to our northwest. Over time, the cloud cover will increase which will turn our skies mostly cloudy by Friday morning. Until then, temperatures are expected to remain very comfortable Thursday evening and there should be no issues with the weather if you have any outdoor plans.

But if you're plans take you outdoors Friday, you'll want to keep tabs on the forecast as a few showers and isolated thunderstorms could roll through during the afternoon and evening. The morning will start off with a bit of cloud cover followed by a few showers mid-morning. These will be left over from a weakening storm complex from the Upper Midwest Thursday night. Conditions will then clear out early afternoon but with dew points rising into the upper 60s it'll feel a little more humid. An incoming cold front late in the day may be enough to trigger a few thunderstorms during the late afternoon and evening, beginning across northwest Illinois and moving east through sunset.

Widespread rain and thunderstorms are not expected but isolated thunderstorms after 4pm or 5pm could be enough to interrupt some evening plans, including night one of the high school football games. While not a washout, you'll want to remain updated on the forecast and radar through the evening. The threat for thunderstorms should decrease after sunset. 

There remains a marginal risk, level 1 out of 5, for isolated severe storms during the afternoon and evening. Biggest threats with any storms that do reach severe limits would be damaging winds and large hail. But an isolated tornado threat can't be entirely ruled out.

  

Great fair weather today, watching rain chances for Friday

Comfortable Thursday:

We're off to a comfortably cool start to this Thursday across the Stateline. Temperatures so far have settled into the low 60s this morning, but it's the dew points in the upper 50s that are really making the difference. With humidity running low, the air feels refreshing and crisp, making for a great morning. 

 

That refreshing feel isn't going anywhere as afternoon highs climb back into the low 80s, and dew points land in the upper 50s. Combined with a mix of sun and a few passing fair-weather clouds, it should be a fantastic late-summer day. 

 

 

Winnebago County Fair:

Great weather for fairgoers as we move into Day 2 of the Winnebago County Fair in Pecatonica. With highs in the low 80s and a good deal of sun, conditions look ideal for spending time outdoors. Now, those heading to Day 3 on Friday will want to keep an eye on radar as our next weather-maker pushes in. 

  

Thunderstorms developing to our northwest tonight into early Friday could hold together long enough to bring a passing shower or thunderstorm to parts of the region as the day gets underway. 

After that, our attention then turns to the afternoon as forecast models suggest another scattered batch of rain developing, especially after 3-4PM. Included is the potential for an isolated thunderstorm. Thankfully, severe weather is not on the table. 

Winnebago County Fair Forecast: Mainly dry and comfortable

 A more comfortable air mass will settle in for Thursday, marked by dew points falling into the 50s! This will result in some patches of fog Thursday morning and bright sunshine for the afternoon. The key difference will be the lack in humidity compared to Wednesday!

Our next chance for rain will develop along a passing weather system Friday. Light showers may be possible as early as daybreak, with better chances for scattered storms along the cold front which will arrive toward afternoon. There will be pockets of dry time in between waves of rain, but be sure to have an umbrella handy if you are out anywhere!

As far as impacts to the Winnebago County fair, most days will end up dry, with Friday bringing the only substantial chance for rain. Any showers and storms will clear by early Saturday afternoon, resulting in a drier second half of the day. Thursday will be especially comfortable, and is the pick day of the week for outdoor activities!

Fog possible this morning, fair weather through Friday

Severe Pushes South:

The strongest storms yesterday fortunately stayed to the north of the Stateline, impacting much of central and southern Wisconsin. Numerous reports of hail and wind were logged from La Crosse eastward to the Milwaukee metro as the cold front pushed through. There was even a tornado report near Menominee Falls, just northwest of downtown Milwaukee, that will likely be further reviewed by the National Weather Service. Closer to home, severe weather was not an issue, though many saw the leftovers, some heavy downpours during the evening.  

Even better news, today's severe weather potential is highest to the south of the Stateline, leaving us here in northern Illinois under the influence of high pressure and much quieter conditions. 

The one issue or hazard will be present for the start of the day in the form of dense fog, which could reduce visibility for the morning commute. Be sure to use caution on the roads, allow extra travel time, and keep your low-beam headlights on. 

Comfortably Warm Thursday:

This quiet stretch will continue into Thursday as high pressure remains parked over the Great Lakes. Expect partly cloudy skies and comfortable temperatures, with afternoon highs landing in the upper 70s. Humidity levels will stay in check as well, with dew points holding in the low 60s. 

 

Winnebago County Fair:

This will leave days 1 and 2 of the Winnebago County Fair dry, though we'll need to keep an eye on a chance for a few showers, and perhaps an isolated thunderstorms, early Friday. Another chance arrives late Friday into early Saturday as weak cold front move on through. At this point, we are not expecting a washout, but it's something to watch if you plan to spend time at the fair, browse City Market, or Friday night high school football.    

Severe thunderstorm watch issued Tuesday afternoon

 8:35pm Update: The severe thunderstorm watch for Green, Rock, and Walworth counties has been canceled.

6pm Update: Other than a few sprinkles/light showers moving across northern Illinois the last couple of hours, the weather locally has been relatively quiet. However, to the north a line of severe thunderstorms continues to move east/southeast, closing in on south-central and southeast Wisconsin. Further to the west an isolated thunderstorm remains west of the Mississippi River in eastern Iowa.

Between now and 7pm the line of storms to the north should move further south, reaching parts of southern Wisconsin. With instability still around the threat for at least isolated severe thunderstorms, mainly in parts of Rock and Walworth counties, will continue. Instability does decrease slightly south of the state line in northern Illinois, and it is a little unclear at this time if the line of storms will hold together or begin to weaken after 8pm. Regardless, we should see at least a few scattered storms move south of the state line after 8pm. At that time, biggest threats will remain heavy downpours and gusty winds.

2:50pm Update: A Severe Thunderstorm Watch has been issued for the following counties in southern Wisconsin: Green, Rock, and Walworth, as well as for Jo Daviess and Stephenson counties in northwest Illinois until 10pm Tuesday.

Current radar as of 2:50pm shows a few spots worth discussing this afternoon. The first are the showers moving across south-central Wisconsin and north-central Illinois as of right now. These are not severe, and hold a very low risk of turning severe, as they move to the east/southeast.

Storms that are developing northwest of Dubuque could maintain some strength as they moving towards northwest Jo Daviess County within the next hour or two and pose a wind/hail threat.

Thunderstorms further to the northwest across central Wisconsin through La Crosse have formed ahead of the main cold front and, at the moment, hold the highest risk of severe. This line would move in later this afternoon - probably after 8pm or 9pm.

In the short-term - will be watching the second area of thunderstorms (near Dubuque) for an impact on northwest Illinois/southwest Wisconsin through 6pm.