Irene - Hatteras island 3 weeks later

[usedtobe]

http://www.indyweek.com/indyweek/three-weeks-after-hurricane-irene-hatteras-remains-in-tatters/Content?oid=2661587#.TnsEBoKiasE.facebook

[Amped]

http://www.indyweek....oKiasE.facebook

It sat over that Island forever

[HurricaneJosh]

That article was shocking to me. I chased the darn cyclone out there in E NC and I had no idea the impact was so extensive-- I guess because I got to the extreme E reaches of the mainland, not onto the barrier islands.

Although Irene wasn't a particularly strong hurricane, it was a large cyclone and it didn't move that fast-- plus, this is such a vulnerable area-- so I guess it makes sense.

Thanks for posting this.

[downeastnc]

Josh the surge for Irene is one of if not THE highest ever recorded in the Pamlico river basin there were places that had 8-10 ft of surge, and there were places on the soundside of the OBX where you could walk out quite a ways out from the beach and still be on "dry" land instead of what would normally be water 2-4 ft deep. All that water was pushed up the river and did a lot of damage including destroying our neighbors cottage at Hickory Point ( Aurora NC ) that had survived ever storm since it was built around 1950. The duration of the fetch was unprecedented as even Fran and Bertha were over in 8-10 hrs this event lasted 18-20 hrs for most of the sounds. Even here in Greenville we had gust exceeding TS force from 3 am Friday night until around 9pm Sat evening. Hatteras had at least 5 new "inlets" but several werent all the way across the island so there really not inlets as I think of them, and Hwy 12 was washed out in at least 7 different places.

A good facebook group to follow for updates for the OBX is Oregon Inlet Idiots...warning they post lots of stuff, their primary focus is to photograph and make fun of/educate all the weekend warriors that think they can drive on the beach without 4WD and or dont know to let air out of the tires to help with traction, they also however know the OBX and are providing lots of stories and info regarding Irene. The damage in towns like Rodanthe, Salvo etc were not really covered by the media and they are in really bad shape as the soundside flooding was the worst anyone has ever remembered seeing.

[Amped]

I read somwhere that faster moving storms produce higher surges along most firm ground coastal areas but areas with marshes and swamps get higher surges from slower moving storms.

[Thunder Road]

The Outer Banks were on Irene's west side, where the highest winds and heaviest rainfall were concentrated.

Whoops.

There's definitely a degree of sensationalism here, since it's hard to imagine Irene being worse than Isabel. Was everything so much worse because of the slow forward motion? I mean it was only a Cat 1. Although I thought its intensity was rated a bit low, since sustained winds actually almost verified if I recall correctly, whereas most hurricanes with a "maximum sustained wind of 115 mph" usually max out at round 95 mph in official obs, for example.

[downeastnc]

Irene was WAY WAY worse than Isabel for all of NC, Irene while not the storngest hurricane ever did several things, she kinda bombed out over the Pamlico Sound and she was crawling and stalling, so instead of weakening she if anything maintained or strengthen slightly. So while the winds never got higher than 70-100 in gust the sustained winds over the sounds had to be 40-70 mph for almost 20 hrs.

The Pamlico Sound is a large shallow ( deepest is around 20 ft and average is closer to 10-15ft ) basin that is EXTREMELY sensitive to wind tides.As she approached the east winds pushed all that water into the creeks and rivers to a level never before documented in many areas. Like I said earlier at this time there were people filmed running out into where the sound should have been 2-4 ft deep on the west side of the OBX islands, the east wind had blown all that water up the Pamlico and Neuse rivers. Then as Irene got north of the Pamlico River the winds went NW/W and since she was still moving pretty slowly she "flushed" all that water out and piled it up against the soundside of the OBX again to levels higher than ever seen before. So those same places that had people running around on "dry" ground where the should have been 4 ft of water there was now 10-12 ft of water. I am at work so cant link you tube and pics etc but there are some crazy surge videos out there were people have 8-10 ft of water pretty far up the creeks and rivers.

I cant imagine how bad things would be had Irene been a Cat 3 with the path and speed she took.......

[Isopycnic]

[downeastnc]

Great video showing how much water came up

http://www.youtube.c...h?v=ux_6pr9GS5o

This video shows where the water she had in her yard came from ( sorta)

My neighbors river cottage or whats left of it

[Bruinsyear]

Irene was WAY WAY worse than Isabel for all of NC, Irene while not the storngest hurricane ever did several things, she kinda bombed out over the Pamlico Sound and she was crawling and stalling, so instead of weakening she if anything maintained or strengthen slightly. So while the winds never got higher than 70-100 in gust the sustained winds over the sounds had to be 40-70 mph for almost 20 hrs.

The Pamlico Sound is a large shallow ( deepest is around 20 ft and average is closer to 10-15ft ) basin that is EXTREMELY sensitive to wind tides.As she approached the east winds pushed all that water into the creeks and rivers to a level never before documented in many areas. Like I said earlier at this time there were people filmed running out into where the sound should have been 2-4 ft deep on the west side of the OBX islands, the east wind had blown all that water up the Pamlico and Neuse rivers. Then as Irene got north of the Pamlico River the winds went NW/W and since she was still moving pretty slowly she "flushed" all that water out and piled it up against the soundside of the OBX again to levels higher than ever seen before. So those same places that had people running around on "dry" ground where the should have been 4 ft of water there was now 10-12 ft of water. I am at work so cant link you tube and pics etc but there are some crazy surge videos out there were people have 8-10 ft of water pretty far up the creeks and rivers.

I cant imagine how bad things would be had Irene been a Cat 3 with the path and speed she took.......

Interesting....how/why did the water leave some areas of the sound and expose "dry" land? Which side of the sound did it occur? I just saw some video on youtube and it was pretty impressive how far out it was. Reverse surge...lol

[usedtobe]

Interesting....how/why did the water leave some areas of the sound and expose "dry" land? Which side of the sound did it occur? I just saw some video on youtube and it was pretty impressive how far out it was. Reverse surge...lol

The sustained winds essentially blow the water from one side of the sound to the other which exposes the bottom. The sustained easterly flow also does not let the water piling up in the rivers of the sound to escape. the combo produces really big soundside flooding. Then when the wind changes direction once the storm passes and gets a westerly component (northwest winds). All the water that piled up on one side comes surging back and inundates the barrier islands. The same type of thing happened on Lake Okeechobee during Wilma. The east side got the inital surge but the seche (backwash) pretty much destroyed all the trailers and homes on Torrie Island.

[downeastnc]

Interesting....how/why did the water leave some areas of the sound and expose "dry" land? Which side of the sound did it occur? I just saw some video on youtube and it was pretty impressive how far out it was. Reverse surge...lol

Its depends on wind direction, another issue that this has is as all that water goes west up the rivers the rivers actually run backwards and the surge causes the rivers even as far inland as where I live to back up. This means that the 12" of rain we had had nowhere to run off to which leads to lots of flooding, but then the winds reverse and literally within 3-4 hrs all the water is gone and the river is blowing out and will actually get really low. Then a few hrs later the rain from upriver causes another quick rise in river levels which in Floyds case became epic.

In the videos of the OBX soundside its important to remember this water is coming from the inland sides of the islands not the oceanside here is a good set of videos to give you a idea the first is in the morning with the center to the south of this location and a wind from the east

Now this is the same spot that afternoon after the center had gotten north of them putting them with a west wind it gets higher than this but it got dark so she didnt get it on film......

[HurricaneJosh]

Well-- I've learned a ton in this thread Re: surge dynamics in this region. Really interesting stuff. Thanks, downeastnc!

P.S. If Irene happened in the 1950s, its central pressure would have earned it a Cat-3 designation when the SS scale was first applied to historical storms (in the 1970s/'80s). We think of 75 kt as being really low for 952 mb. However, I suspect that Irene's wind-pressure relationship was not that unusual for this high latitude (~35N); instead, I think we've just been overestimating the winds in a lot of the mid-century storms in this region. Reanalysis is going to address all this-- I think particularly with the cluster of mid-1950s strikes in E NC.

[shaggy]

Well-- I've learned a ton in this thread Re: surge dynamics in this region. Really interesting stuff. Thanks, downeastnc!

P.S. If Irene happened in the 1950s, its central pressure would have earned it a Cat-3 designation when the SS scale was first applied to historical storms (in the 1970s/'80s). We think of 75 kt as being really low for 952 mb. However, I suspect that Irene's wind-pressure relationship was not that unusual for this high latitude (~35N); instead, I think we've just been overestimating the winds in a lot of the mid-century storms in this region. Reanalysis is going to address all this-- I think particularly with the cluster of mid-1950s strikes in E NC.

Its not uncommon to see surge effects even in the winter time here in NC. The way the tar/pamlico river is oriented allows strong NW winds after strong coldfronts to blow the water out. This sometimes drop the water levels of the river even inland down by a foot or two at times.

[usedtobe]

That article was shocking to me. I chased the darn cyclone out there in E NC and I had no idea the impact was so extensive-- I guess because I got to the extreme E reaches of the mainland, not onto the barrier islands.

Although Irene wasn't a particularly strong hurricane, it was a large cyclone and it didn't move that fast-- plus, this is such a vulnerable area-- so I guess it makes sense.

Thanks for posting this.

Your welcome, I wasn't sure how much interest there would be in the article. The seche dynamics are particularly bad over the sound systems in NC because the water is so shallow and the land is so close to sea level. You get the ypical storm surge but also don't allow the rivers to drain as the surge and easterly flow keeps the waters bottled up in the rivers. Places like Lake Okeechobee also have a big slosh from side to side when a hurricane passes. Wilma was huge aroudn the lake especially on the southeast side when the water sloshed back east with the force of the northwesterly winds.

[Ginx snewx]

Your welcome, I wasn't sure how much interest there would be in the article. The seche dynamics are particularly bad over the sound systems in NC because the water is so shallow and the land is so close to sea level. You get the ypical storm surge but also don't allow the rivers to drain as the surge and easterly flow keeps the waters bottled up in the rivers. Places like Lake Okeechobee also have a big slosh from side to side when a hurricane passes. Wilma was huge aroudn the lake especially on the southeast side when the water sloshed back east with the force of the northwesterly winds.

You tube videos are pretty insane.

[usedtobe]

You tube videos are pretty insane.

ON the top video, the one house right before you get to the new cut through looks like it will be toast the next storm that hits.

[Ginx snewx]

ON the top video, the one house right before you get to the new cut through looks like it will be toast the next storm that hits.

yea, the IKE was quite large for a Cat1, winds are not the only factor in seiche and surge as you know. I still have those aerials from Lake Ochee Wilma seiche.

[HurricaneJosh]

Just a quick note: there is essentially no relationship between size and intensity-- meaning there is no typical size for a Cat 1 versus a Cat 3. Given this, there was nothing strange about the fact that this Cat 1 was large.

If anything, the really intense cyclones tend to have small cores-- especially as they intensify and peak.

[usedtobe]

yea, the IKE was quite large for a Cat1, winds are not the only factor in seiche and surge as you know. I still have those aerials from Lake Ochee Wilma seiche.

When I original found those aerials I was shocked at the devastation. I've been back to the island and it's slowly recovering but without the homes. They still are working on the dike on the east side though it's become so expensive they are rethinking the fix.

[downeastnc]

The duration of Irene also played a large role typically storms move through here much quicker, I mean it blew hard for LONNNGGGGG time around here.

On a related note the wind tide here is so fast and strong that as Shaggy mentioned water levels can drop/rise several feet pretty quick. There is a little bridge over a creek we like to fish and with our small jon boat we can get under the bridge if there is a south or west wind and get to some really good spots that dont get fished much but if the wind changes we gotta head out cause a north or east wind will raise the creek level quickly and trap us on the wrong side of the bridge.

Another time we were duck hunting a yr or so after Hurricane Floyd and the wind was strong out of the NW and had been for a day or so after a big front. The creek was blown out lower than we had ever seen and we noticed a strange looking "box" half submerged in a area that would normally be 2-3 ft under water in a section of bank you couldnt get to even when the water was up. After a few more hrs the water dropped a bit more and we realized it was a coffin.....it must have floated during Floyd ( this happened ALOT) and ended up there, it was a moment for sure.......we called the sheriffs office to try and send someone to get it but we never heard what happened and everytime we fish or hunt that creek I get creeped out a bit.

[usedtobe]

The duration of Irene also played a large role typically storms move through here much quicker, I mean it blew hard for LONNNGGGGG time around here.

On a related note the wind tide here is so fast and strong that as Shaggy mentioned water levels can drop/rise several feet pretty quick. There is a little bridge over a creek we like to fish and with our small jon boat we can get under the bridge if there is a south or west wind and get to some really good spots that dont get fished much but if the wind changes we gotta head out cause a north or east wind will raise the creek level quickly and trap us on the wrong side of the bridge.

Another time we were duck hunting a yr or so after Hurricane Floyd and the wind was strong out of the NW and had been for a day or so after a big front. The creek was blown out lower than we had ever seen and we noticed a strange looking "box" half submerged in a area that would normally be 2-3 ft under water in a section of bank you couldnt get to even when the water was up. After a few more hrs the water dropped a bit more and we realized it was a coffin.....it must have floated during Floyd ( this happened ALOT) and ended up there, it was a moment for sure.......we called the sheriffs office to try and send someone to get it but we never heard what happened and everytime we fish or hunt that creek I get creeped out a bit.

Interesting about the coffin. Lake Okeechobee has wind driven tides that can leave you stranded. I've had a couple of friends who had to have airboats tow them in after getting stranded in shallow water. It was fine when they arrived in the area and anchored to fish with shiners but then the wind switched from a nice northly wind to a strong southerly one and they got stranded.

[Bruinsyear]

The sustained winds essentially blow the water from one side of the sound to the other which exposes the bottom. The sustained easterly flow also does not let the water piling up in the rivers of the sound to escape. the combo produces really big soundside flooding. Then when the wind changes direction once the storm passes and gets a westerly component (northwest winds). All the water that piled up on one side comes surging back and inundates the barrier islands. The same type of thing happened on Lake Okeechobee during Wilma. The east side got the inital surge but the seche (backwash) pretty much destroyed all the trailers and homes on Torrie Island.

Wow, extremely impressive. I had a feeling the wind caused it but when you actually see the exposure of the sound floor I think it really makes the power of the surge a more tangible thing. When you have a setup like the sound or Okeechobee its almost like a small scale version of what is going on over the ocean during a hurricane. Obviously the waters are too deep out there for the wind to clear out the water to the bottom, but its the same general idea.

Pretty cool stuff!