One of the Most Amazing Tornado Videos, Ever -- A Candidate For Photogrammetry

By -
Earlier this month, two major tornadoes occurred in Minnesota. The Basehunters (a storm chase team) posted their 4K video yesterday and there are things I believe are worth bringing to your attention.

The first is the ding to the windshield (below).
I believe that was caused by flying debris. It looks similar to a bullet strike. That is why we urge you not to take video of a tornado. If flying debris strikes you, you could be killed or seriously injured. 

 The second is the sound of the tornado.

I've heard many tornadoes and this is the first I've heard that sounds just like a jet engine. If you have ever been on the tarmac of a busy airport, you'll recognize the sound when the photographer steps out of the car. If you wish to watch this segment full screen, click here.

This tornado has the strongest, tightest rotation of any tornado I have personally seen or video/film that I have viewed. It would be valuable to know the windspeed of this tornado.

On April 2, 1957, a tornado struck north Dallas. A photogrammetry study was done on the video below, specifically the black and white segment (depicting flying debris) that begins when you start the clip.
In 1960, the journal Monthly Weather Review published the study (known as the "Hoecker Study") that calculated wind speeds of 170 mph in the horizontal and vertical wind speeds up to 150 mph. This would be an F-3 tornado on the original Fujita Scale. [When I tested the video last night, it worked fine. Now, it is requiring you to play it on YouTube from the beginning. The Hoecker Study portion begins at 1:00 and lasts until 1:16. Sorry for the inconvenience.]

To my knowledge, there was no research Doppler radar on this tornado. Even if there was, the circulation is so tight it probably could not be resolved.

The 4K video taken by The Basehunters has far more resolution than the Dallas film. So, I would urge that a photogrammetry study be done on this particular tornado to measure the wind speeds in the horizontal and the vertical. We might be surprised what we learn. 


Blog Post: © 2020 Mike Smith Enterprises, LLC

Comments

Post a Comment

Popular posts from this blog

Hilary's Forecast Path Shifts West; Updated 9:20am PDT

By -
Image
The forecast path of the center of Hilary has shifted a bit to the west. This increases the threat to the Southland, especially in terms of flooding.  Rainfall Note the heavy rains are forecast for Los Angeles County. Serious flash flooding may result. Because the forecast path has shifted to the west, that increases the threat of serious flooding in Los Angeles County north into Yosemite and the southern Sierra. It lessens the threat in Utah and western Arizona. While the threat of widespread flooding in Utah and Arizona lessens, note that some thunderstorms with localized heavy rain show up on the map.  In Nevada, the more western path increases the risk of serious flooding around Mt Charleston and into the central part of the state.  Here is the updated  (9am PDT) flash flood risk map. Wind There are already about 40,000 people without power in California, mostly in the center of the state.  The maps above are the peak gusts forecasted with the storm. The highest winds, in general,
Read more

Dangerous Travel Conditions - People Reportedly Stranded

By -
Image
-- Note, more current info available. Scroll up. --- Updated Information as of 8am PDT You are risking your life if you attempt to travel through the purple area.  While the rain has not begun in coastal California, I would urge you to use this time to make any preparations. Power outages have occurred already in southeast California. Here is the latest radar as of 7:55am PDT. As of 6:40am PDT , the radar indicates moderate to heavy rain falling over desert areas of Southern California and far western Arizona (click to enlarge).  Rainfall amounts for the 24 hours ending at 7am PDT show more than two inches have already fallen. There are reports from reliable sources that roads are already washed out and that people are stranded in isolated parts of the desert.  Below is a high-resolution computer model's rainfall forecast from 5am PDT to 11pm PDT Sunday. More than a foot of additional rain is forecast to fall. This will lead to catastrophic flooding.  Here is a map of current watc
Read more

Update on Tornado and Wind Potential; 12 Noon PDT

By -
Image
There was at least one tornado and at least one funnel cloud yesterday.  --- original forecast --- Hilary (the swirly symbol) continues to move NNW paralleling the coast of Baja California, Mexico. The area outlined in red has a significant risk of tornadoe s the rest of the afternoon.  Below is a list of peak wind gusts so far.  Peak winds may increase farther north as the afternoon progresses.  Addition at 12 noon PDT: Sure enough, winds have increased.  Note: If you are in the San Diego area, I recommend not  traveling east on I-8. Heavy rains may cause flash flooding that will involve the highway. 
Read more