Showers Today, Strong Storms Possible Tomorrow

Yesterday was simply a gorgeous day across the Stateline for St. Patty's Day, with plenty of sunshine and temperatures topping out in the upper 40s. Now, hopefully you were able to take some time yesterday to get outside and enjoy the beautiful sunny weather, because it's a totally different story when it comes to our forecast for today. A wet and active pattern will slide in  for the second half of the work week, not only bringing rain chances, but also thunderstorm chances into the mix.

After cloud cover increased overnight last night, an area of light to moderate progressed into the area from eastern Iowa, bringing a wet start to our Wednesday. For those that are heading out this morning, it would be wise to grab an umbrella and keep on hand with you throughout the day. Under cloudy skies, scattered shower chances will continue through the rest of the morning and into the mid-late afternoon hours.   While a rumble or two of thunder cannot be ruled out, that threat is going to be confined primarily west of Rockford. This round of rain will be relatively light, leading to accumulations below or right around a quarter of an inch. Where the heavier pockets of rain develop, upwards of a half an inch could add up. The second round, which arrives tomorrow with a warm front, features a higher chance for heavy rain, especially with the development of thunderstorms.

The Set-Up: Tomorrow is the first day of astronomical spring. And what's more fitting for the first day of spring then a chance for thunderstorms. A strong and dynamic low pressure system will track into central Iowa, lifting a warm frontal boundary through the Stateline and into southern Wisconsin by tomorrow afternoon. As the warm front slides northward, it will bring a round of showers and thunderstorms early on in the afternoon, between 12 PM and 3 PM. Once we enter the "warm sector" of the mid-latitude cyclone, this will provide the opportunity and environment for severe storms to develop. The time frame that we can expect severe storms will be confined to the late-afternoon and evening hours.

We'll have to keep a close eye on the development of these thunderstorms as a few have the potential to become strong or severe thunderstorms, especially later on in the day. The Storm Prediction Center continues to place all of northern Illinois and southern Wisconsin under a marginal risk, which is level 1 of 5 in the severe weather risk categories. The primary mode of severe weather is damaging winds and heavy downpours, but hail and even an isolated tornado cannot entirely be ruled out. Farther to the west, closer to the low's center, is a higher threat for severe weather. A slight risk (level 2 of 5) has been drawn across the state of Iowa as they will be dealing with a little more clearing in sky cover than us here in the Stateline. Storm chances drop off quickly by midnight Friday.

Even though we just rapped up Severe Weather Preparedness Week here in northern Illinois, please be sure to have multiple ways to receive watches and warning issued by the National Weather Service. Severe weather season is now just getting underway, and it is very important to stay updated with the forecast and to be alert of what's going on around you.