2022 09/28
SWMI AMS/NWA Chapter Meeting Minutes
Wednesday, September 28, 2022
West Michigan Aviation Academy
5363 44th St., Grand Rapids, MI 49512
Attendance: Alana Dachtler, Jim Carpenter, Craig James, William Marino, Kreigh Tomaszewski, Tom Oosterbaan, Matt Kirkwood, Warren Wheeler, Nathan Jeruzal, Bill Oosterbaan, Andy Schut
Call to order: 7:10 pm
Cort called the meeting to order and started off with introductions of the new board members as well as our invited speaker for the evening, Nathan Jeruzal from the Grand Rapids NWS office.
The results of the summer forecast contest were shared next. John Laurens, Matt Kirkwood, Jim Carpenter and Bill Marino won and will receive a $10 credit toward their annual dues.
Next, Cort gave a presentation on Hurricane Ian which made landfall as a category 4 hurricane earlier in the day. He shared some slides on the NHC predicted track as well as some comparisons of GFS data run-to-run. He also found an image on Twitter comparing the size of the eyewall of Hurricane Charley from 2004 with the eyewall of Hurricane Ian, it showed that Charley was a much more compact and could fit completely within Ian’s eye with room to spare.
After Cort’s presentation, Nathan started his talk with a look at the current radar as Ian continued to move inland. Next, he shared a map of extra weather balloon launches on Saturday to assist in providing additional data for forecasts. Nathan then moved on the main portion of his talk about waterspouts on the Great Lakes. According to Wade Szilagyi (Waterspout Wade) and the International Centre for Waterspout Research, climatology from 1994 – 2018 shows that waterspouts are most commonly observed on the Great Lakes during the month of September with 544 occurrences. One of the main reasons for this is the lag between air temperature vs. lake temperature where lake effect rain really starts to ramp up in September as the water remains warm (often close to 70 degrees) while the air temperature begins to drop into the 60s. Waterspout ingredients include a mid/upper-level trough/low, warm lake water and low-level convergence. Nathan then gave a little bit of background information on Waterspout Wade; he is a Canadian meteorologist and has done a lot of work studying the formation of waterspouts, he even developed a nomogram that is very widely used when forecasting for waterspouts. The x-axis of the nomogram is Sea – 850 mb temperature difference and the y-axis is the LCL.
Nathan then moved on to share some examples of waterspouts. He showed a Skew-T from Bufkit for Ludington on Monday, September 26th, 2022. It showed ~700 J/kg of CAPE over Lake Michigan with an LCL around 2 kft. This yielded a decent chance for waterspout development. While none were observed on Lake Michigan, there were several observed on Lake Erie near Buffalo, NY and Cleveland, OH. Another example was shared from Monday, September 12th, 2022. Conditions were quite favorable according to Szilagyi’s nomogram and in fact a waterspout was photographed near St. Joseph on that Monday. His final example was from Monday, August 8th, 2008 and in this instance, a waterspout was actually captured on video in South Haven and shared with the Grand Rapids NWS. There is a facebook page for the International Centre for Waterspout Research where Waterspout Wade shares a lot of his maps and graphics and is a great resource to learn more: https://www.facebook.com/InternationalCentreForWaterspoutResearch
A few minutes of questions followed and the meeting adjourned at 8:23 pm.