Those Pesky Derechos

[Whiteman]

I was intrigued by some of the dire weather warnings which preceeded the present heat wave. There were warnings up for possible derechos, or Mesoscale Convective Systems. Looking through some old posts, some folks were out in the
Ontario-Adirondack Derecho of 1995, which knocked down millions of trees in the Adirondacks. (That's a lot of trees!) Winds up to 100 mph, storm moving along at more than 60 m.p.h.

Anyway, since this was a new weather phenomenon to me, I could not resist sharing it.

There are some vague warnings about these systems threatening the region again this week, so keep that weather eye open!

Cheers.

 

[weatherman]

Three things make these systems stand out as being particularly dangerous:
1. They tend to happen late at night/early AM in the Northeast, a time when few of us are watching out for weather.
2. They move FAST- up to 60 mph! So, little warning. Their winds can be ferocious!
3. They tend to occur in areas (like the North Woods) where severe weather is relatively rare, on the north side of those big hot high pressure areas. Some meteorologists call them "ring of fire" thunderstorms.

Fortunately, they are not real common. But my antennae go up anytime I'm camping and the weather has been really hot and I hear thunder after midnight in my tent. Not a bad idea to seek shelter in a stronger place, if that's possible.
-Weatherman

 

[Kevin Rooney]

So ... were all the downed trees in the ADKs in recent years the result of Hurricane Fred, the The Ontario-Adirondacks Derecho of July, 1995, or some of both?

Anyone know the answer?

 

[Nessmuk]

So ... were all the downed trees in the ADKs in recent years the result of Hurricane Fred, the The Ontario-Adirondacks Derecho of July, 1995, or some of both?

Anyone know the answer?

There have been a number of localized but intense storms in the past couple of years that have done a lot of damage... so one cannot say all the trees were downed in 1995. But especially in the NW Adirondacks including the Five Ponds Wilderness area, the blame pretty much all belongs to the derecho. I go into there several times a year and know first hand the extent of the damage and slow changes since then.

 

[Doc McPeak]

Kevin, the derecho or '95 microburst (as Nessmuk points out) hit more out of the HPs region, than in. Floyd, on the otherhand, was the one of the biggest hits to the HPs since the big hurricane in the 50's. Almost a dozen new slides, including the big one on Colden that has forever changed Avalanche Pass.

This past winter included several nasty hits as well to the HPs. There are many trails that are still covered in blowdown, especially those out of the way. I did The Shorey in early June and it had over 50 big trees across the path. In the woods is total carnage. An ice storm has snapped the tops of thousands of balsam and spruce trees. The high ridges are hurting bad.

I've been in VT and NH this summer and haven't seen anything even close to what I've seen in the ADKS.

 

[lumberzac]

In addition to the storms Doc McPeak listed, there was also the ice storm of 1998 that damaged about 3 million acres of forest in northern New York (note that not all of this was in the park).

 

[Pat T]

Interesting thread you started, Whitelief.

In addition to the storms already mentioned, there was a pretty significant wind event in the ADKs this past February. And we've had a couple of huge rain storms, both last fall as well as this year. Trees with shallow root systems (common in the ADKs), are very susceptible to wind damage when the ground is soaked.

I just looked at the radar (it's almost 10 pm)--there is a pretty good line of storms in Canada and they are headed in this direction. I hope it doesn't generate another microburst. I was here (southeastern ADKs) in '95. It was a very hot, muggy morning and I had just put on my shoes to go out for an early morning walk. Skies were cloudy but there was no thunder or other signs of an impending storm. As I walked from my camp down to the road there was a sudden wind shift and the northeastern sky turned a very strange shade of green. Lightning, thunder, and serious wind started almost immediately. We sat out the storm inside the camp--it was pretty scary. It was a full week before much of the damage was even reported in the papers--lots of folks were without power and telephones for an extended period and communication was difficult. Later that summer, we visited some leantos and read leanto logs in which people described probably the most harrowing experience of their lives. Ironically, we had been planning a trip to High Falls for that August. Needless to say, we did not make it that year.

Pat T

 

[Artex]

I just looked at the radar (it's almost 10 pm)--there is a pretty good line of storms in Canada and they are headed in this direction.

I've been watching that storm also with great interest. It looks huge.

I've seen what looked to be the after effects of a microburst outside of Baxter SP before. Pretty crazy.

 

[Whiteman]

Best Radar for Storms

Usually I just look at the www.erh.noaa.gov sites for radar. This week my brother turned me onto the NEXRAD radar at www.wunderground.com, which has some pretty cool features.

There is a tab for the NEXRAD radar, and you can throw in six frames of animation (more if you want to pay), and click on storm tracks to put the vectors and speeds in for the current object of interest. They also label tornados, mesocyclones and hail storms. And there's more.

Those Quebec storms do look pretty hopping tonight, but I think on the scale of thunderstorms they end up vanilla.

Cheers.

 

[Nessmuk]

Friday, July 14 1995 I arrived at a public park near Saratoga for a weekend of wilderness first aid training. We set up our tents at the edge of a clearing/woods to spend the night. It was the hottest muggiest night I could ever remember. I heard it never got below 80 that night. Just as light was breaking around 5:00 Saturday morning I could hear distant thunder in the west, muted by the distance but nearly constantly booming. I quickly installed and firmly staked down the rainfly on my tent.

We all stood outside and watched the brightening sky and saw amazing sights I had never seen before. Imagine the entire sky filled with gray cotton balls, tightly packed together in a solid plane, thousands of them. Lightning fingers traveled in wandering knarled strands horizontally at the bottom of the cotton ball clouds. Constant lightning, purple sparks covering the sky horizon to horizon in all directions without stopping. I don't recall any thick cloud to ground strikes, just the cotton balls and intertwining fingers of light at the lumpy base. I zipped into my tent as the wind and rain hit. It blew hard, but all was over in just a few minutes.

A few tree branches came down near us, but I had no idea of the extent of the damage done on such a wide scale over the Adirondacks. We heard later a woman in the area was killed in her car when a tree fell on her. I believe 6 people in all died in that storm. A number of backwoods campers were rescued by helicopter as the only way to get out. Had it been Saturday night with many more campers in the woods things would have been much worse.

Though not totally accurate, one visualization of what happened is that a broad line of thunderstorm downdrafts literally brought the jetstream down to ground level. No circulating tornadic flow, just straight line 100 mph wind.

 

[Kevin Rooney]

Kevin, the derecho or '95 microburst (as Nessmuk points out) hit more out of the HPs region, than in. Floyd, on the otherhand, was the one of the biggest hits to the HPs since the big hurricane in the 50's. Almost a dozen new slides, including the big one on Colden that has forever changed Avalanche Pass.

This past winter included several nasty hits as well to the HPs. There are many trails that are still covered in blowdown, especially those out of the way. I did The Shorey in early June and it had over 50 big trees across the path. In the woods is total carnage. An ice storm has snapped the tops of thousands of balsam and spruce trees. The high ridges are hurting bad.

I've been in VT and NH this summer and haven't seen anything even close to what I've seen in the ADKS.

Thanks, Doc. I could have been a little clearer on my timeframe. I climbed most of the ADK's in July thru October, 2001, and have been back only a few times since. Some may recall that Allen had just re-opened (Sept, 2001?) due to the damage from Floyd. In addition to that devastation, from the top of Blake you could see when a microburst skipped down the ridge. Other areas that seemed particularly devastated was the main trail leading into Dixes above the lodge and the slides around Avalanche Lake.

 

[sardog1]

The July 4, 1999, derecho in Minnesota and Ontario brought down 665,000 acres of trees. Many canoe campers in the BWCAW were trapped by piles of downed trees that obliterated portages and they had to be rescued by helicopters. (This summer part of the blowdown has been burning in a fire that has burned nearly 32,000 acres.) It continued on to bring down trees in Quebec, New York and New England.

I dimly recall another similar event out West that trapped some elk hunters several years ago.

 

[Quietman]

Here are a few of my favorite weather radar sites

Intellicast Nexrad
Nexrad Composite(wider area)
Severe Storm Summary
National Weather Sevice Regional Radar

 

[lumberzac]

Thanks, Doc. I could have been a little clearer on my timeframe. I climbed most of the ADK's in July thru October, 2001, and have been back only a few times since. Some may recall that Allen had just re-opened (Sept, 2001?) due to the damage from Floyd. In addition to that devastation, from the top of Blake you could see when a microburst skipped down the ridge. Other areas that seemed particularly devastated was the main trail leading into Dixes above the lodge and the slides around Avalanche Lake.

My first attempt of Dix was in the spring after Floyd from Elk Lake. I’ve never seen so many downed trees in my entire life. It looked like a sadistic version of pickup sticks. We hiked for about a half-hour from our campsite at Slide Brook. The trail was simply not there. In its place were acres of trees piled 20+ feet high. We decided to turn around and head back to camp and ended up getting lost. 4 hours later we made it back to camp.

 

[Kevin Rooney]

My first attempt of Dix was in the spring after Floyd from Elk Lake. I’ve never seen so many downed trees in my entire life. It looked like a sadistic version of pickup sticks. We hiked for about a half-hour from our campsite at Slide Brook. The trail was simply not there. In its place were acres of trees piled 20+ feet high. We decided to turn around and head back to camp and ended up getting lost. 4 hours later we made it back to camp.

IIRC, Floyd was in the Fall of 1999, so when I did alot of hiking there 2 years later the damage still seemed very fresh. Speaking of bushwhacks - on that particular day I'd gone up the slide to Macomb, and after making my way over that peak, Hough and a couple of Dixes, I overtook a group of 3 young guys, and 2 of them were really beat. They decided to take a drainage down to the main trail while their friend went with me to the Beckhorn. Once back on the main trail back to the TH at Elk Lake we waited for over an hour for his friends to finally emerge, telling tall tales of ghastly blowdowns. Personally, I've never seen such destruction in a forest.

 

[Pete_Hickey]

IIRC, Floyd was in the Fall of 1999.....

Actually, summer. Sept 10 or so. It had been a very dry summer, and there were numerous forest fires burning, including the Bearden-Noonmark fire. In its defense, Floyd did put out the fires.

Also, the dry conditions before, is what helped it to cause so many slides. People who have plants in flower pots, will notice how, whne very dry, the soil tends to shrink away from the pot. This happens to the soil on the rocks, and the sudden flow of water lets them slide easier.

The destruction from Floyd was amazing. Numerous areas of a quarter square mile, with every single tree down. (The '95 microburst had larger areas). Back in the summer of '00, from teh summit of Dix, one could see large areas with all the trees down. When working on Pinnacle Ridge, a year later, we had a crew of 9, including 4 chainsaws, and it took us a full 11 hours to cover about a mile.

Oh yeah... One of the things with the derecho, is the direction of the wind. It is coming somewhat downward, which is something the trees have not built up resistance against.

 

[Tom Rankin]

Imagine the entire sky filled with gray cotton balls, tightly packed together in a solid plane, thousands of them.

I've seen pictures of these in the past, but just last week saw the phenomenon first hand in the Western Catskills. Fortunately, the storm just missed us, but it looked like a whopper!

Does this phenomenon have a name, and does it portend severe weather?

 

[sardog1]

I've seen pictures of these in the past, but just last week saw the phenomenon first hand in the Western Catskills. Fortunately, the storm just missed us, but it looked like a whopper!

Does this phenomenon have a name, and does it portend severe weather?

Yes, and no. They're mammatus clouds.

 

[Puck]

I am sorry but I can't help from thinking that all of these blow downs can create some great bird habitat. Has there been an increase of woodpecker, owl, nuthatch, blackpole etc numbers in this area? On the other hand this would have an adverse effect on crossbill, grosbeak and finch numbers...

 

[DougPaul]

I am sorry but I can't help from thinking that all of these blow downs can create some great bird habitat. Has there been an increase of woodpecker, owl, nuthatch, blackpole etc numbers in this area? On the other hand this would have an adverse effect on crossbill, grosbeak and finch numbers...

Might also have an adverse effect on the birds in residence when the big winds hit...

Doug