T-Storms Part 2 : "North and West of the city!"

[CoastalWx]

Looks like a microburst occurred in Hollis NH, but the wind intensity surprised me. I would have expected a lot more damage from a 110mph microburst. They also seemed to mention rootballs a lot, but rootball diameters seem to vary a lot due to nature of root system and topsoil composition, but they mention it as some sort of metric used to justify intensity. I obviously don't do storm surveys, but maybe Chris or others can shed some light on that.

[Typhoon Tip]

So post them for once

 

I have so far managed to download them from my camcorder to my home PC, and am now trying to learn how to use VideoWave built into this freeware, so that I can edit.  

 

That said, other than very small video clips we have a limit as to object size we can upload, so I probably would have to go through youtube or something.  

 

All I really have is about an hour of CB growth/evolution, in HD, that I want to speed up the film... I can do it manually by pulling the indicator along the scroll bar, but I want the video to be rendered in faster motion.  It's a tough hobby, because you need about 3 relentlessly long hours to get about 15 minutes of sped up cloud videography.  

[CoastalWx]

I have so far managed to download them from my camcorder to my home PC, and am now trying to learn how to use VideoWave built into this freeware, so that I can edit.  

 

That said, other than very small video clips we have a limit as to object size we can upload, so I probably would have to go through youtube or something.  

 

All I really have is about an hour of CB growth/evolution, in HD, that I want to speed up the film... I can do it manually by pulling the indicator along the scroll bar, but I want the video to be rendered in faster motion.  It's a tough hobby, because you need about 3 relentlessly long hours to get about 15 minutes of sped up cloud videography.  

 

Speed up the growth of this...  

[Ginx snewx]

I have so far managed to download them from my camcorder to my home PC, and am now trying to learn how to use VideoWave built into this freeware, so that I can edit.

That said, other than very small video clips we have a limit as to object size we can upload, so I probably would have to go through youtube or something.

All I really have is about an hour of CB growth/evolution, in HD, that I want to speed up the film... I can do it manually by pulling the indicator along the scroll bar, but I want the video to be rendered in faster motion. It's a tough hobby, because you need about 3 relentlessly long hours to get about 15 minutes of sped up cloud videography.

time lapse editing, check out free versions on Google.

[BillB]

Looks like a microburst occurred in Hollis NH, but the wind intensity surprised me. I would have expected a lot more damage from a 110mph microburst. They also seemed to mention rootballs a lot, but rootball diameters seem to vary a lot due to nature of root system and topsoil composition, but they mention it as some sort of metric used justify intensity. I obviously don't do storm surveys, but maybe Chris or others can shed some light on that.

 

Much of the information we included in the Public Information Statement (PNS) was offered in the interest of transparency, letting everyone know what we found. The 110 mph value is for the maximum damage found; per EF indicators, this is the expected value (not highest nor lowest) for maple trees that were snapped.  Snapped pine trees have an expected value of 104 mph.  Obviously not all of the damage was at maximum. Expected values for uprooted trees/rootballs is 94 mph for hardwoods(maples), and 87 mph for softwoods (pines).  Expected value for large branches (hardwood and softwood) is 74-75 mph.

[CoastalWx]

Much of the information we included in the Public Information Statement (PNS) was offered in the interest of transparency, letting everyone know what we found. The 110 mph value is for the maximum damage found; per EF indicators, this is the expected value (not highest nor lowest) for maple trees that were snapped.  Snapped pine trees have an expected value of 104 mph.  Obviously not all of the damage was at maximum. Expected values for uprooted trees/rootballs is 94 mph for hardwoods(maples), and 87 mph for softwoods (pines).  Expected value for large branches (hardwood and softwood) is 74-75 mph.

 

Thanks for answering. I've seen snapped pines/maples and rootballs happen with 60-80mph winds so that's why I was asking. Winds above 100mph will cause borderline blowdowns to happen and structural damage (I've seen this in the May 1996 Brockton MA macroburst where winds were 104mph). Pictures have not been easy to come by as well in that area...at least what I could find, other than a picture of a tree uprooted here or there. I assume there are thresholds for tree diameter as well when it comes to snapping of trees...as well as height where the snap occurred. 

[Ginx snewx]

Thanks for answering. I've seen snapped pines/maples and rootballs happen with 60-80mph winds so that's why I was asking. Winds above 100mph will cause borderline blowdowns to happen and structural damage (I've seen this in the May 1996 Brockton MA macroburst where winds were 104mph). Pictures have not been easy to come by as well in that area...at least what I could find, other than a picture of a tree uprooted here or there. I assume there are thresholds for tree diameter as well when it comes to snapping of trees...as well as height where the snap occurred.

https://www.google.com/url?sa=t&source=web&rct=j&ei=XP4MVMfYL8q2ogTWnoGoCw&url=http://www.ejssm.org/ojs/index.php/ejssm/article/viewFile/111/87&cd=14&ved=0CCQQFjADOAo&usg=AFQjCNEk6DWAd67MbIz1O9VI1iZNl1ix0A&sig2=rUnIRakCkb21FfDm-maegg

[CoastalWx]

https://www.google.com/url?sa=t&source=web&rct=j&ei=XP4MVMfYL8q2ogTWnoGoCw&url=http://www.ejssm.org/ojs/index.php/ejssm/article/viewFile/111/87&cd=14&ved=0CCQQFjADOAo&usg=AFQjCNEk6DWAd67MbIz1O9VI1iZNl1ix0A&sig2=rUnIRakCkb21FfDm-maegg

 

I saw that earlier actually. Interesting paper. Shows how variable it can be. I know around here, 100mph will do significant damage to trees not just some snapped trees here and uprooted trees there.

[dendrite]

I saw that earlier actually. Interesting paper. Shows how variable it can be. I know around here, 100mph will do significant damage to trees not just some snapped trees here and uprooted trees there.

Can you imagine 100mph in Tolland? My god...

[CoastalWx]

Can you imagine 100mph in Tolland? My god...

 

[ryanjn]

I've documented about 25 streets in North Andover with trees or limbs down. I'm gonna plot them on a map. Most were within a 1 square mile area. I'd guess 60-70mph straight line winds. Is there a criteria NWS uses when it comes to deciding which towns damage to survey? I'm sure my neck of the woods wasn't as heavily damaged as the other microbursts they surveyed but I'd still say it was still one hell of a downdraft that was responsible for this. I'll post pics and my map when I'm done. A handful of trees on houses and cars, too. 

[ryanjn]

Looking at that journal of wind damage criteria I retract my estimate of 60-70mph and would say much higher. There were defiantly large rootballs in uprooted trees, some uprooting through the sidewalk. Several hardwoods snapped about 4-5ft up the trunk. Probably some neighborhoods saw 75-85mph. I have to examine the photos and see what types of trees they were and such though.  

[CoastalWx]

75-85 will do a ton of damage. I feel like we as humans tend to overestimate winds in tstms when you have all that wind and rain rushing in. It does not take much wind to cause damage on fully leafed trees.

[Nittany88]

I think I remember hearing of some study at some point that people tend to overestimate winds at the low end of the scale but underestimate it at actual high speeds.

[bobbutts]

I have so far managed to download them from my camcorder to my home PC, and am now trying to learn how to use VideoWave built into this freeware, so that I can edit.  

 

That said, other than very small video clips we have a limit as to object size we can upload, so I probably would have to go through youtube or something.  

 

All I really have is about an hour of CB growth/evolution, in HD, that I want to speed up the film... I can do it manually by pulling the indicator along the scroll bar, but I want the video to be rendered in faster motion.  It's a tough hobby, because you need about 3 relentlessly long hours to get about 15 minutes of sped up cloud videography.  

if you put what you have on youtube I will gladly speed it up and upload it back

[dryslot]

Can you imagine 100mph in Tolland? My god...

 

The acorn damage would be worse then an IP peltfest

[ryanjn]

75-85 will do a ton of damage. I feel like we as humans tend to overestimate winds in tstms when you have all that wind and rain rushing in. It does not take much wind to cause damage on fully leafed trees.

According to the DOD article someone posted, trees are uprooted with an expected value of 87 - 91mph. There were def trees uprooted. Many large branches and limbs over 12 inches in diameter, some probably 18in, that's about 75mph according to the DOD (although it doesn't tell me branch diameter, at least the chart I saw). However, some of the tree branches and trunks weren't all completely healthy, some had hollow spots or off-colored wood which means perhaps a lot of them would be on the lower bound which would maybe be 60mph. The lower bound for trees uprooted is still in the 70'smph though. KLWM about half a mile NW of where most of the damage was had a gust of 54mph, and there was little damage besides some branches down in that area here and there. I don't think it would be far fetched at all to assume North Andover had a small stretch that received 75-85mph winds.  

[CoastalWx]

I disagree about some "assigned" values that a study found. There are too many variables to just assign a value for trees uprooted. I saw a pine snapped from 50mph winds in Sandy. I saw plenty of trees snapped and uprooted from 60-75mph winds in the Feb 2010 windstorm. What is the soil like? Is it wet? Is it sandy? What kind of tree is it? Does the tree have a lot of leaves or little leaves? Does the tree have a lot of branches? Are the branches spread out on the tree or is the tree top heavy? Is the tree healthy? Is the core rotted out or the tree diseased? There are just too many variables. I've seen trees snap in 50mph winds and 90mph winds. I'm not saying those winds you claim didn't occur...but some of those values in that study seem awfully high. It's probably the best thing we have at the moment to judge, but common sense and experience casts a little doubt. 

[amarshall]

Storm I took a picture of coming into MCO airport Saturday.  We got 5" of rain in 3 hrs.  Serious rain down there.

 

[TalcottWx]

Crap. Can't believe I didn't catch those winds

[weatherwiz]

Storm I took a picture of coming into MCO airport Saturday.  We got 5" of rain in 3 hrs.  Serious rain down there.

 

 

That's amazing!

[bobbutts]

In the Feb 2010 wind storm I lost around a dozen trees.  All of them with the exception of one very rotten tree were at the bottom of a small ravine where the soil had become very wet and muddy.  Also many of the trees lost were taken out like dominoes as the first one fell into the next and so on.  Point being, if it weren't for the wet soil, tree damage would have been much more limited given the same winds.

[TalcottWx]

I've seen some big time lightning storms but that one was up there. The lightning driving up 495 north between lowell and lawrence was frightening. We didn't catch the winds Andover did because I was behind the storm by a few minutes. Still would have estimated gusts to at least 50 with the way the trees were swaying near Westford. I was about a mile south of the downdraft (near bertucci's at 125 and andover st). We had a lot of limbs but no major downed trees, big difference from just a mile up the road. Might take a ride up there later to check things out. Campus and my area lost power for only a few minutes, and a manager on campus was struck by lightning, also a tree was splintered by a strike.

[TalcottWx]

Here's a shot on 495 right before I drove into the storm 

[Brian5671]

Tons of damage in Fairfield..with storm 2 bearing down on them now

 

 

Round two here. Lightning is even more intense with this one. Best severe day I can remember in quite a while!

Best severe day in years-close to 2 inches of rain and intense CTG lightning, all sorts of tree damage especially southern 1/2 of town.  Really came on came quick too.  Developed right overhead.

[CT Rain]

I disagree about some "assigned" values that a study found. There are too many variables to just assign a value for trees uprooted. I saw a pine snapped from 50mph winds in Sandy. I saw plenty of trees snapped and uprooted from 60-75mph winds in the Feb 2010 windstorm. What is the soil like? Is it wet? Is it sandy? What kind of tree is it? Does the tree have a lot of leaves or little leaves? Does the tree have a lot of branches? Are the branches spread out on the tree or is the tree top heavy? Is the tree healthy? Is the core rotted out or the tree diseased? There are just too many variables. I've seen trees snap in 50mph winds and 90mph winds. I'm not saying those winds you claim didn't occur...but some of those values in that study seem awfully high. It's probably the best thing we have at the moment to judge, but common sense and experience casts a little doubt. 

 

The amount of damage should factor in. 2 snapped trees in a forest may tell you more about the trees themselves than the wind speed. Unfortunately, there are so many variables that assigning wind values in any damage survey is very challenging with very large error bars as we've discussed here before.

 

I'd be happy with the EF scale going to a weak/strong/violent kind of deal. 

[TalcottWx]

Got to drive around n andover for the first time. Dozens of downed trees. Some snapped mid trunk right in half. Some of the larger trees looked like someone threw a grenade at them, splintered all over but not uprooted. Definitely some larger trees uprooted in the area of mass ave. Verizon and national grid along with town crews working on every block. Tree landscape crews hard at work too.

[CT Rain]

Did a bit of blogging about last week's tornado in upstate NY and the tornado debris signature. Another interesting case. Many borderline/weak tornado events have been able to produce TDSs in the northeast... probably due to how widespread/thick our forests are. 

 

http://ryanhanrahan.com/2014/09/08/another-new-york-tornado-debris-signature/

[ryanjn]

I did some more surveying in weir hill in North andover. The path I walked was from the base to the top which is a couple hundred ft asl. There was an area that of about 100 yards were I saw probably 5 to 7 healthy hardwoods mostly oaks snapped right at the base. Some uprooted trees and countless limbs 8 to 18 inches in diameter blown down. Most trees faxing east or south eaat. A couple possibly south facing. In my opinion north andover definitely received a microburst that was roughly a mile long and 0.75 miles wide. I took notes and pictures and will plot them on a map and post it when I get the chance. I also have video from showcase cinemas which is where 114 meets 495 in lawrence where I'd estimate 60mph winds occured. This was about half mile se of where most of the damage occured, although there was also tree damage reported nearby my location in se part of lawrence.

[powderfreak]

Storm I took a picture of coming into MCO airport Saturday. We got 5" of rain in 3 hrs. Serious rain down there.

That's really cool, thanks for sharing.