2021 12/07
Southwest Michigan AMS/NWA
7 December 2021
West Michigan Aviation Academy
5363 44th St
Grand Rapids MI 49512
President Warren Wheeler called the meeting to order at 7PM. There were 9 people in attendance including 3 board members.
Warren Wheeler gave the Treasurer’s report, which was unchanged from last month. The savings account has funds of $582.00 with $71.88 in the
checking account.
We are trying to secure our next speaker, Valerie van Heest, who has written a book on what was at the time, in 1950, this country’s worst
commercial aviation disaster. Her book “Fatal Crossing” takes a look at what may have caused the DC4 to crash into Lake Michigan west of South
Haven killing 58 people. Debris and body parts have been found but not the aircraft.
Those of us present voted to approve paying van Heest a $125 speaker’s fee for her presentation. A date will be announced as soon as confirmed.
Our speaker for this evening was our vice president, Cort Scholten, a lead forecaster at the local National Weather Service office. His topic was about tornadoes originating from non super cell thunderstorms.
The vast majority of tornadoes are produced by super cell thunderstorms but occasionally, small, weak, and short lived tornadoes can form in non super cell conditions. They occur within what is called a Quasi-Linear Convective System or QLCS. Quasi-linear because you rarely ever get perfectly straight lines in nature. A sample radar image may look like this.
These types of tornadoes are rare enough, small enough, and frequently obscured by rain resulting in the fact there has never been a photo of one taken in Michigan. Fortunately, they usually only last a few moments and are of F0 or F1 intensity, however, in extremely rare cases, can reach F3 intensity.
The parameters necessary for a non super cell tornado to develop are rather technical and require a good amount of training for a radar operator to recognize. Even when all the conditions seem to be met, only about 25% of the time will a tornado of this type occur. The NWS in a situation like this will usually issue a severe thunderstorm warning with the notation that a small tornado or brief spin-up is possible.
The meeting was adjourned at 8:10 PM
Respectfully submitted
Craig James Woods, Secretary