A developing thunderstorm south of Burlington; looking at the Great River Bridge from the Illinois side / Photo credit: Kevin Radley on YouTube, May 19, 2013 severe weather event
The good, the bad, and the ugly
We’ve made it. From the winter that couldn’t let go comes spring. You can trim your beard and set your winter coat and ice scraper at least to standby mode. We get plenty of spectacular weather around here this time of year — sunshine and mild temperatures without persistent humidity — sort of like autumn except for lawn mowing instead of leaf raking — and garage sales instead of candy. It’s weather that deserves an article all its own, and there’s always time for those.
Following our beautiful transitional weather this week and coming weekend, this next work week will feature changes in the position and strength of our main jet stream, the river of air high in the atmosphere that pushes our weather across the country.
Winds at the surface will include an enduring southerly component that will deliver Gulf of Mexico moisture to the atmosphere over the middle of the country, including us. Winds higher in the atmosphere though will increasingly become westerly with increasing height. If you ever hear weather folks talk about wind shear, that’s what they’re referring to.
The favorable jet stream pattern, wind shear, moist atmosphere, mild temperatures, and an approaching cold front will all come together to produce the first noteworthy and classic severe weather event of the season for the middle of the country.
Location and timing
From this point, we’re probably 5+ days away. Tuesday afternoon and especially evening and night look to be an official kickoff to severe weather season. At the moment, I think much of Iowa, Northern Missouri, Eastern Nebraska, Eastern Kansas, and Oklahoma is the general area in the running. A day later, on Wednesday evening and night, severe weather will reload and strike the middle of the country again.
Either or both days could bring tornadoes, hail, high wind, or heavy rainfall threats to us. The “Burlington Bubble” is also still possible — that we get rained on but miss the severe weather to our west on Tuesday evening and to the south on Wednesday evening.
This is the right time to coordinate with family and have your severe weather plan in place — knowing what you will do in various circumstances whenever severe weather threatens. I noticed The National Weather Service office out of Amarillo, Texas has done a great job putting together such a page.
Computer model depictions of weather for Tuesday evening/night and Wednesday evening/night