Weather Blog: Cool season Derecho swings severe weather through Kansas City

KANSAS CITY, Mo. — Good Monday Morning Bloggers -

Did the wind and thunder wake you up last night? Between having an anxious dog, a toddler and a passion for following the weather... I'm definitely having a case of the Mondays! It's not everyday you get to track a derecho, so I wanted to take some time to explain the science.

First and foremost, what is a derecho?
According to the National Weather Service, a derecho is a widespread, long-lived wind storm that is associated with a band of rapidly moving showers or storms. There are a few specific criteria that need to be hit in order to a storms footprint to be considered a derecho and those are:

1. Wind reports cover at least 240 miles
2. Those wind gusts are severe in nature, meaning reports are at least 58 mph

70% of all derechos occur between the months of May-August, which we consider the warm season. The other 30% occur from September-April, which we consider the cool season. On top of that, in Kansas City we tend to see a derecho once every two years. So while the atmospheric set up was textbook, the storm itself was kind of out of place.

So where did all the wind come from? Let's talk about this textbook set up.

1. The Low level jet was positioned right across the Midwest
2. We had a very strong deepening low pressure, which ended up strengthening to the equivalent of a category one hurricane
3. Thunderstorms developed and funneled the strong low level jet down to the surface
4. This created a line of storms that continuously fueled themselves basically

The SPC (Storm Prediction Center) labeled this event as a derecho early on in the day, stating in their discussion, "
A derecho is forecast with widespread damaging winds and embedded swaths of significant severe gusts from 80-110 mph, centered on parts of Oklahoma this evening into tonight. Embedded tornadoes are anticipated as well, with the greatest potential for strong (EF2-EF3) tornadoes across southwest Oklahoma this evening."

By the time this line of storms got to the KC area the system was still capable of producing 60+ mph wind gusts, although brief, the criteria for a derecho was met.

Our team was tracking the storm all night and when it was all said and done, they tracked 7 severe thunderstorm warning with the main focus revolving around the wind threat.

Storm reports were focused in on wind, but we also saw some healthy rain as well. The Kansas City area picked up just under 0.5'' of rain with the heaviest rain hugging the Topeka- St. Joe line.

KSHB

This was definitely a unique system to watch unfold and just to our south multiple tornadoes were reported into Oklahoma.

We are going to shift into a quieter weather pattern for a few days, but all eyes are on our next system that looks to arrive Thursday into Friday. This one will be a tricky one to watch as it puts the rain-snow line right over Kansas City... again! But some models have the comma head of the storm very close by which means we could see a boom or bust kind of snow potential set up. So stay tuned bloggers!