Quiet weather today followed by warm and stormy day tomorrow

 

After another quiet day yesterday with high pressure sticking around, we can expect a very similar day today as well. High pressure won't be sticking around as long today ahead of our next weather system pushing in tomorrow but for most of the day, we'll see sunshine and continued comfortable temperatures.

Through the morning hours however, a few showers have worked their way through northern Iowa, which may begin to extend towards the state line but those shower chances this morning remain very isolated.

Into the rest of the day, we will once again have sunshine along with temperatures approaching 70! It'll be even warmer than yesterday however with a stiff wind out of the southeast today around 10-15 mph those temperatures may feel a little cooler.

Tomorrow though is the day we've been keeping an eye on the most as another dynamic low-pressure system is expected to move into the Midwest through the afternoon. Not many changes in the forecast have been made since yesterday as we're still a little unsure if storms will persist or weaken as they approach the state line tomorrow night.

Before diving into the storms, a bit deeper it's also important to note that with a passing low-pressure system we'll see windy conditions return. Through the afternoon the combination of low pressure along with sunshine heating the surface will allow wind speeds to be sustained near 20 mph while also pushing gusts up to 35 or even 40 mph.

Strong winds at the surface may also affect thunderstorm intensity as we head into the evening however there's two main ingredients we're focusing on right now which is atmospheric instability and the "low level jet."

The most important ingredient with thunderstorms is the instability as unstable air allows air to rise and create thunderstorms. Tomorrow, areas to our north and west will see much more instability than us allowing for more thunderstorm development. As night begins to set in instability tends to go down due to the surface cooling.

Our thunderstorm threat tomorrow is expected to be in the evening hours, which often in most cases sees decreasing instability into the night. Most forecasts for this event have kept true with that, however if instability hangs around into the evening thunderstorms will persist for a little longer.

Another key factor in tomorrow's forecast will be the nocturnal "low level jet." The low-level jet is normally a little less than a mile above us in the atmosphere and is often a focal point for severe thunderstorm forecasting. During the nighttime, we lose sunshine allowing temperatures to cool at the surface. The surface temperatures become cooler than the air above allowing for stronger winds to develop just above the pocket of cooler air. This then increases the amount of "shear" or how much our winds turn with height. When low level winds begin to turn this can help sustain thunderstorms along with give them a little more juice.

If thunderstorms persist through the night and into the state line tomorrow, they will experience a rather strong low-level jet. So, if thunderstorms do keep their strength as they move in the possibility of them staying severe will be there with the combination of low-level winds and instability. These ingredients will be known a lot more as we head through tomorrow, still through the day today make sure to go over your severe weather plan and make sure to have multiple ways to receive watches and warnings.