815 Day Forecast

Today is not just another Thursday, but it's 815 Day across the Stateline. A day where we get to celebrate the city of Rockford. And if you can't go out and partake in the festivities, I only ask for you to do one thing. Please take a few minutes to step outside and just enjoy the beautiful weather that mother nature is presenting us with today. It is essential that you take a few minutes of your time to soak in the pleasant conditions. A high pressure system at the surface will be in command through our Thursday bringing nothing but sunshine to our region. That along with the combination of low humidity and comfortably warm temperatures will make for a spectacle of an afternoon. Winds out of the north and northeast should limit our highs only to the upper 70s to low 80s.

High pressure currently sitting to the west of the region will slowly slide over the Great Lakes region later today. This will allow a bit of moisture to stream in resulting in a spotty afternoon shower or two to develop primarily over our eastern counties as a lake breeze boundary comes off Lake Michigan. But rest ashore, many dry hours are in store through the day and into the overnight.

As a disturbance tracks through the jet stream, it will bring a chance for showers and thunderstorms. Before midnight, things look to remain fairly dry! If you are planning on going to the Winnebago County Fair in Pecatonica, dry weather will persist through the event. Though clouds will likely be on the increase as the system draws closer. Rain chances don’t really arrive into the forecast until around the time of the morning commute tomorrow morning. As usual, heavy rain is possible underneath any thunderstorm that develops. Between Friday and Monday of next week, several rain chances will move through. We will also experience an uptick in the humidity levels as winds switch to a more southerly and southwesterly direction.

Brief Funnel Clouds Wednesday Afternoon

Widely isolated showers developed Tuesday afternoon and evening and produced brief heavy downpours. Lightning was absent from most of the shower activity, so thunder was extremely limited.

The showers developed as an upper level low moved over southern Wisconsin and northern Illinois. At the surface, there was a weak boundary (wind convergence line) over northern

Illinois. Cumulus clouds started to build high in the sky as the low passed overhead. The quickly rising clouds and boundary near the surface allowed enough convergence and spin to develop in the atmosphere to produce brief funnel clouds.

The pictures above were taken shortly after 12:30pm Tuesday afternoon from Browns Mill Road in Stephenson County, looking to the east/southeast. The photos are from Patrick

Murray. You'll notice the funnel isn't very big and is not attached to a thunderstorm cloud. These types of funnel clouds rarely touch down and typically don't last too long. If they do touch down, minimal damage can occur.

Rain Chances Continue Into Our Wednesday

Before we jump into the forecast for today, a few of our viewers captured stellar weather pictures this morning. First, we would like to thank our First Warn weather watcher Sandy Bruch. She took this photo of a blanket of fog laying over the corn fields in her backyard. In fact, visibility in portions of Stephenson, Lee, and Whiteside Counties did drop below 1/4 a couple of times as the morning progressed. Clutch sunrise photo Sandy!

Our second photo comes out of Delavan, Wisconsin up in Walworth County. An isolated thunderstorm that was tracking east towards Milwaukee produced an outflow boundary, also known as a gust front, as it was weakening. Fellow storm chaser Corey Bull captured this stellar photo of a shelf cloud on the leading edge of the gust front as it was tracking through Southern Wisconsin. We tend to call pictures of individuals in front of a shelf cloud a "shelfie".  There's some weather humor for you!

As far as the weather for today, a low pressure centered over southwest Wisconsin will continue to track southeast ward through the day and could provide the spark for additional rain and storm chances this afternoon. The severe threat looks to remain low for today, but a gusty isolated thunderstorm or two is possible. Part of the reason severe weather isn’t expected relates to the shortage of instability or energy in the atmosphere. Shower chances look to linger into this evening, but shouldn't bring any hazardous driving conditions on your drive home later on.

While we have some humidity still sticking around, conditions through the day will feel a tad less muggy from what we experienced yesterday. Today's highs will only climb into the upper 70’s under mostly cloudy skies. If we get some clearing, a few spots could peek into the low 80's. But, the most recent visible satellite imagery shows just how stocked our area is with clouds as that low pressure continues to spin southeastward into northern Illinois. Now today is the first day of the Winnebago County Fair. Gates open at Noon! If you are heading out to the fair today, just have a place to go under or have the umbrella on hand just in case a few showers do pop up this afternoon and evening. Happy "Hump" Day Stateline!

Isolated Thunderstorms Tuesday Evening

Isolated thunderstorms have developed over parts of Wisconsin and northeast Illinois Tuesday evening. Severe weather is not expected, but a thunderstorm moving across McHenry County in northeast Illinois is capable of heavy downpours and gusty winds. This storm is moving to the southeast towards the northwest suburbs and Chicago.

A few additional thunderstorms over southwest Wisconsin will move southeast into Jo Daviess and Stephenson counties. These storms are weakening, but will still be capable of heavy downpours.

Most of the storm activity will last through sunset with isolated showers and mostly cloudy skies heading into Wednesday morning. An approaching low pressure system from the north will help aide in a few additional showers for Wednesday afternoon and evening. Severe weather is not expected with those storms.

Strong to Severe Storms Continue Downstate, Bypass Much of the Stateline

A new Tornado Watch has been issued for all of central Illinois and west-central Indiana through 3am Tuesday morning. Severe storms were quick to develop over central Illinois, near a warm front, Monday evening. Flash Flood Warnings and numerous severe thunderstorm warnings have also been issued.

The warm front has stayed south of the area all afternoon leaving our air mass overhead a little more stable. There's been quite a bit of wind shear (changing wind speed/direction) above the surface, but the instability was lacking. There has, however, been quite a bit of moisture in the atmosphere and that allowed some of the rain showers to be efficient rain producers.

Light showers will continue through Midnight but locally dense fog will likely become more of a concern by Tuesday morning. Visibility has already fallen down to under a half mile in some locations.

Heavy Rain Moving Through Parts of the Stateline Monday Evening

Steady to moderate rain has been falling over southern Wisconsin and northern Illinois Monday evening. These showers have been forming north of a warm front and low pressure system currently moving into west-central Illinois. The current cloud cover has kept the warm front draped across central Illinois and will limit how far it lifts north Monday night.

As low pressure moves further into Illinois late

Monday evening widespread showers and thunderstorms are expected to develop, and have already begun to blossom over parts of Iowa and Illinois. The highest risk for strong to severe storms will most likely remain south of the immediate Stateline area, but could come close to parts of Whiteside, Lee and DeKalb counties. There, storms with gusty winds and heavy rainfall will be possible.

Further north the greater threat will most likely remain periods of heavy rainfall through Midnight. The rain coming down now will come to an end between 6pm and 7pm, but additional showers have already begun to develop to the southwest and will continue to lift northeast with the arrival of the low.

Active Start to the Work Week

After nearly cutting our Summer rainfall deficit by half Sunday morning, a low pressure system later on today will bring another opportunity for heavy rainfall stretching into tonight. As of this morning, the Storm Prediction Center continued to have the northern half of our viewing area under a Marginal Risk (1 out of 5), while placing the southern half under a Slight Risk (2 out of 5). The highest risk for severe weather today remains to our south stretching through a good portion of central Illinois.

The system that Meteorologist Candice King had mentioned in yesterday's post has moved over the strong ridge of high pressure in the southern plains and  has been displaced to the southwest of the region. Along with it, a warm front continues to lift northward towards central Illinois. Now, model guidance continued to show the front just falling short of the Stateline by settling the I-80 and I-88 corridor. South of the boundary instability (energy in the atmosphere) will build during the afternoon. This will lead to explosive thunderstorms late in the afternoon and evening.

For us here in the Stateline, it is looking like a few thunderstorms have the capability of taking  on severe characteristics by producing gusty winds and small sized hail.  The main concern we are watching is the heavy rainfall threat going into the early hours of our night tonight. The main system looks to pass over the viewing area pulling a large amount of moisture. While observing the models this morning, PWAT values or what is known as Precipitable Water, is the amount of water in a column the atmosphere. Most soundings had observations over 2.0" which is a pretty high moisture content value. Models take the highest values of mositure right over the region tonight. So expect rain to be heavy at times this between 6 PM and 10 PM this evening. If you are heading out this morning and are not coming back till later today, make sure to grab the rain gear as you head out the door. Following today's storm chances, the weather will become a bit more tranquil and cooler towards the middle of the week.