Minnesota weather: Widespread rain likely over the weekend

Don't get too excited because you may jinx it, but what could be the first widespread soaking rainfall we've seen since April is looking more likely over the weekend. 

I realize it's not well-timed, occurring on a weekend, but we've had SO many dry and nice weekends this summer that we're really on borrowed time anyway. And we certainly need the rain as our drought continues to expand.

While many areas have seen at least a little rain over the last couple of weeks, in most areas it was just enough to get to average levels of moisture for that timeframe. What we need is persistent above-average moisture to press our way out of the drought. But the other issue isn't just how much rain we receive, but how quickly it falls. It has to fall slowly enough that a lot of it can soak into the ground instead of becoming runoff. Runoff is certainly needed to refill our bodies of water, but the most important aspect of rain is what soaks into the ground and replenishes the overall soil moisture to at least 3 feet of depth.

Let's just hypothetically say the metro gets a foot of rain in just 6 hours. This will NOT happen with this storm, for the record. In this hypothetical case, flash flooding would be massive and everything would be absolutely soaked. But the drought wouldn't actually be over — and likely wouldn't improve as much as you think. That's because the rain would fall just too fast for much of it to soak in. That's why big-time flash flooding would occur because the top couple inches of soil wouldn't be able to soak in the moisture fast enough, creating extensive fast-moving runoff that would run into our creeks, rivers, and lakes. Sure, it would help significantly raise the water levels of our bodies of water, but wouldn't have significant impacts on the soil moisture below a couple of inches of depth.

Now, exactly how this weekend unfolds remains to be seen. There are several other features across central North America that could derail at least some of the rain while simultaneously making it a bit more sporadic. Because of this, a washout is NOT expected in most areas, so don't cancel outdoor plans. However, you definitely want to have a backup indoor option if things go awry.