Have a look at this picture (click to enlarge):
We had a tornado here a couple of hours ago. It did not come near our house. It was probably an F2 or so in strength, and based on videos and the reported damage path it was about three or four tenths of a mile wide or wider at times, as it moved along a path of about 10 miles or so (maybe 20 by some reports), four of those miles being as a strong well formed twister taking out houses, toppling trees, etc. etc.
As I say, it did not hit us, but it was large enough and close enough that I could hear it. You know, that freight train sound. At first I thought the sound was continuous thunder that was so even and continuous that it sounded like one continuous boom, but it wasn’t that. There wasn’t any lightning, and it did not actually sound like thunder, so I gave up on that idea. Then I considered that it was an actual freight train, but for that to be true they would have to have moved the tracks from the west of my house to the southeast of my house. Not likely. I would have noticed.
I heard this as I stood in the open garage watching the rain, an iPad showing the radar Wundermap in one hand, my camera in the other. I could see the edge of a hooked-out storm cloud thought to contain, according to the weather service, a tornado pass to my left (east), on both the radar and in real time. There was actually blue(ish) sky to my right (west) which corresponded nicely to the radar signature.
The rain was very heavy, and the drops falling straight down, and there was not a whiff of wind. And then, suddenly, tiny pieces of vegetation started to fall as though they were part of the rain, from a level well above the standing trees in our neighborhood. This photograph is a sampling … actually, these are the pieces that fell nearest to me, unselected … of what came down.
I assume that this is tornado debris. These fragments of leaves, quite battered as you can see, could have come from anywhere up-stream along this tornado’s path, then spread out from the twister’s updrafts into the surrounding storm, where the calm air at the margin of the disturbance allowed them to fall with the rain back to the earth.
The leaves were collected approximately six miles to the west of the line drawn here. Given the size of the tornado, the vagaries of determining where updrafts would have been, and uncertainty of where the tornado actually tracked (thus far … this will be more carefully measured by the weather service), these leaves could have traveled anywhere from 2 to 6 miles laterally after being blown into the air by the storm, but in an oblique line running out from the tornado track of several miles longer. I quickly note that only leaves fell from the sky. Heavier debris clearly fell out long before it got here I also quickly add that we do not yet know if there was only one twister in this scenario. There probably was only one, but this awaits confirmation.
If there were any microorganisms living on the tree leaves on the west side of the Mississippi ’round these parts, they’ve been successfully dispersed to the east side of the river, in large numbers!
I know this is a small and irrelevant thing compared to the damage and destruction, and overall tragedy, that has happened in North Minneapolis and surrounding areas. But I thought the strangeness of it worthy of writing up and sharing.
More about tornadoes here.