A "Pot of Gold" Forecast, Followed by Rain Chances

First off. Happy St. Patrick's Day Stateline!

We kicked off St. Patty's day with a cold front that slid through the Stateline while we were preparing for our day this morning. Surface winds before the front were blowing lightly out of the west-southwest. Once that frontal boundary sliced through the region, our surface winds came more from a northwesterly direction. This allowed for clouds to clear out and for a drier air mass to filter into the region. As of a result, we have sunny skies out there this morning.

I said it in my blog post yesterday, and I'll say it again. On paper, you couldn't have asked for a better forecast for St. Patrick's Day. Today features an abundance of sunshine, with mild temperatures. Highs today will climb into the upper 40s, close to 50°. An occasional northwesterly gust of 15 or 20 mph are possible, which could provide a chilly feel to the air. Even with that said, a beautiful and mild afternoon is on tap for the Stateline. I know that most if not all plans for St. Patrick's Day have been cancelled. But that shouldn't stop you from going outside, and enjoying the sunshine. Get outside while you can, because rain chances return to the forecast before sunrise tomorrow morning.

Light precipitation is likely to move into the Stateline from the west during the predawn hours tomorrow morning. Temps overnight are going to fall into the low to mid 30s, which could result in a few wet snowflakes or even a brief period of sleet to start. As warmer air gets pulled in by sunrise, any wintry precipitation that does manage to fall will quickly transition to a chilly rain. Rain will become more widespread and stick around with us for much of the morning.  Rain chances are likely going to begin tapering off by late Wednesday afternoon. Although a few pockets of heavy rain are possible, rainfall totals should remain light with the first wave.

For Thursday, a more dynamic situation will be unfolding as we'll be dealing with a much stronger and deeper storm system. One that is set to bring a multi-day severe event to portions of the southern plains. A strengthening low over the Midwest is going to help lift a warm front through the Stateline Thursday afternoon. Once this frontal boundary is on top or north of the Stateline, this will put the region in the warm sector of  the of low pressure system. Typically, this is the area of the mid-latitude cyclone that's between the warm front and the cold front, and the area in which all the warm moist air is transported to. The uncertainty with this system is how far north it tracks. This will give us the answers to how far north the warm front will lift by Thursday afternoon, and the severity of the thunderstorms.

The Storm Prediction Center (SPC) has placed all of our counties in northern Illinois under a marginal risk for severe thunderstorms. This is the first categorical severe risk for the Stateline of 2020. A "Marginal" risk is the lowest risk on the totem pole, aside from non-severe or a general thunderstorm risk. This threat looks to be confined to the afternoon and evening hours, coinciding with the greatest instability or energy in the atmosphere. As of right now, the main threats for any storm that becomes severe will be damaging wind gusts, heavy downpours, and frequent cloud to ground lighting.