US Chase Map Project

So this update is kind of late for the 2017 season, but wanted to get it out there anyway. This adds info for the remainder of the western and eastern US. I also got permission from the Reddit user WestCoastBestCoast94 to include the road image he generated, so that underlayer has been included....mostly shows up as gray patchiness at these resolutions. I've exported 3840px wide versions, but they're 4MB each, and not sure if the site will let me upload those.

Versions with and without tree canopy below:

US_ChaseMap_20170529withForest_1920px.jpg


US_ChaseMap_20170529_1920px.jpg
 
Jun 16, 2015
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quincyvagell.com
Great work, Jeremy. I've been a huge fan of this map and it's awesome to see it completed, coast to coast. I keep a hard copy in my car for quick reference. Sometimes if I'm debating on chase targets, I will assess road networks and visibility as important considerations, making this map we useful. Even though I've traveled the Plains quite extensively over the last few years, I still reference this map. (Especially when deviating east of the Plains.)

Having grown up in the Northeast, it's also nice to see New York mapped. I knew that parts of upstate New York had relatively chaseable areas, and now that has been objectively evaluated here. Despite some hill and tree issues, I've also chased in North Carolina a few times and this map confirms the not-so-awful road networks there.
 
Thanks for the feedback Quincy, I'm glad it's been useful! I'd probably hedge on calling it objective...it's based on a visual assessment of the road network, so there's a fair amount of subjectivity in there. At a variety of points, I'm positive people could find things that aren't spot on. Texas was questionable in a lot of places, because of how often the road grid there is rotated 45°. At available resolution I couldn't visually tell if those networks were truly gridded or not, so they got knocked down in quality due to uncertainty. Mainly, I tried to err on the side of pessimism if I couldn't tell for sure how well gridded the network was.

Despite all that, I've been pretty satisfied with how it's held up in areas where I've chased. The area in NW Oklahoma/Barber County Kansas definitely checks out as sketchy; some tough road choices too in the less networked area in N Texas along the Red River; but then some pretty decent zones in the Mississippi flood plain. The map gave me confidence with a setup that looked like it could produce in that flood plain & I caught a tornado near Grady, Arkansas last year because of it. Some day, North Dakota shall call, and I will answer.
 
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Jun 16, 2015
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quincyvagell.com
Reviving an old, but very useful thread and adding in a map of my own, inspired by @Jeremy Perez.

I took a base map and overlaid it with a road network map. To come up with the road network, I actually filled in the space between roads as red. This happens to show how sparse a road network may be, like across central Nebraska, but also works to show where the network is so tight that it's an urban area/concrete jungle of sorts. It was easy to "remove" the roads if there was a consistent, but not tightly spaced road network, as you would expect to see in a larger city.

From there, I used a map of the forest canopy to show where most of the relatively tall trees are. The resolution isn't the greatest, but it gives you a general idea of what's going on. Something is wrong with the colors in the Northwest. I think it is terrain related, as I don't believe there should be so much whitespace across western OR/WA.
evaluation_3000px.gif
 
Dec 8, 2003
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I am looking at this very carefully, and could it be that some of that tree data is incorrect? Is that possible that there are so few trees in SC LA? How about right around Lake Tahoe? OH and MI, too. I have been to all those places, and maybe the green-shaded areas are only meant to depict the very thickest of forest canopies. There are some pretty wooded areas of E KS, too.
 
Jun 16, 2015
347
731
21
32
Oklahoma City, OK
quincyvagell.com
I am looking at this very carefully, and could it be that some of that tree data is incorrect? Is that possible that there are so few trees in SC LA? How about right around Lake Tahoe? OH and MI, too. I have been to all those places, and maybe the green-shaded areas are only meant to depict the very thickest of forest canopies. There are some pretty wooded areas of E KS, too.
So it looks like the green color represents "aboveground woody biomass" and the threshold I used for the map is about 75 tons per hectare. Below that was removed, which explains cases such as eastern Kansas and southern Louisiana. However, if I zoom in on a very high resolution image of the map, you can notice some green specks.

The density of trees/biomass across the Pacific Northwest is so high that it seems to have been removed from the map. I may amend this at some point, but for the vast majority of areas that chasers would target (Plains/Midwest), I feel this map is fairly representative. Although an area like eastern Kansas has some wooded areas, it's nowhere near as obstructive as areas around the Ozarks, for example.

More information:
Forest cover by state and territory in the United States - Wikipedia