Knocked down by mini tornado & question....

[stevensuf]

We have just arrived in the Canaries after a somewhat eventful journey from Gibraltar, Some 200 miles out, my other half took her turn at watch, I left her with 10 kn about 60 degrees off the starboard beam and a full jib, but no main up, the wind had been very low and from lots of directions so I had left the main packed away.

About twenty minutes into her watch, the sixth sense kicked in and i got up, to find 20-25 kn of wind slowly aft of the beam, so got dressed to help her with the sails.

By the time i got dressed the wind had gotten up to 35 kn and we were furling the jib to reef it wen some huge hail stones started falling, that were actually very painful when they hit you, we both dived for cover down below decks.

After less than 30 seconds i noticed the 40 percent of the jib that was left up was backed, the wind had done a 180 degree shift, so we got up as the hail had reduced to furl up the jib completely.

While trying to turn the boat into the wind i was very confused, the wind appeared to be turning faster than i could turn the boat, my other half was busy trying to furl in the remaining jib when bamm, the boat just started heeling and heeling till the guard rails were under the water and the side opening portllights were also under water, luckily enough they were all closed.

After about twenty seconds we were still pinned down , so i released the jib sheet and we sprung back up, a quick look at the wind gauge showed 65 kn, i managed to motor in a strait line and gave up trying to point into the wind and we escaped from the mini tornado.

My question is just how much wind would it take to knock down and keep pinned down a boat which is 43 foot and 13 metric tonnes and only had about 250-300 foot of sail up?

[jeremiason]

Sounds like you and your wife experienced a fast moving squall or maybe a water spout. I take it you didn't see it coming on radar? No damage or injuries?

I am assuming your abreviation "KN" means knots..., which converted to miles per hour is about 56 mph, which on my boat means a diaper (Nappy for our English speaking friends) sized sail to keep forward way.

You kind of answered your own question, since you were knocked down, you had up to much sail.

I don't believe you will get an accurate answer to your question, because there are too many variables.

The fact is, that in the situation you describe, the only real answer is reduce sail till the boat gets back to a managable heel or release the sheet as you did and lef the sail flog til you can reef it down more. That could mean be going bare poled and still making way in some high winds.

You and your wife survived, so you did the right thing at the time... Good job!

[rhr1956]

I have no idea how much wind it would take. I do have a good idea of what large hail looks like. This video shows a hail storm that lasted about three minutes. The hail was big, but fortunately was not rock hard. I have seen marble size hail do far more damage to cars etc than what this stuff did. You can imagine what this size hail would do to your noggin if it was frozen solid.April 3, 2012 - YouTube

[belizesailor]

Sounds much like a water spout. They usually form along frontal boundaries, and your description of the weather sounds very much like a frontal boundary or similar feature.

There is not a lot you can do about a water spout. They can form very quickly and behave erratically once formed. Your actions sound reasonable to me.

Only improvement I could suggest is being more attentive to the weather around you when crossing any significant weather feature like a frontal boundary or tropical wave.

[rhr1956]

I guess one good thing about a water spout is they dont sling two-by-fours and stuff through the air. A swordfish would probably be a problem though:-)

[belizesailor]

Sounds much like a water spout, which had not yet sucked up water, to me. They usually form along frontal boundaries, and your description of the weather sounds very much like a frontal boundary or similar feature.

There is not a lot you can do about a water spout. They can form very quickly and behave erratically once formed.

In general your actions sound reasonable to me. You got through it OK and that is the real test. The only improvement I could suggest is being more attentive to the weather around you when crossing any significant weather feature like a frontal boundary or tropical wave.

I just looked at Lifted Index (a measure of convection/stability) as far back as Tuesday (06/11 0600 GMT) and there was an area of less stable (than now) air along the African Coast. When, and where (lat/lon), did you knock down occur?

[DeepFrz]

Actually 65 kn is about 78 mph.

[Andrew Troup]

I personally doubt you'll ever encounter circumstances like that again, at least not offshore. There are places (usually glacial fiords) where winds of that strength can change direction fast enough to pin a boat down - but that's because of the topography of the land.

I have encountered a mini tropical revolving storm which established quicker than we could furl sails, and it certainly blew a lot harder than 65 knots, but that took between half an hour and an hour to clock around 270 degrees in the course of passing over us... you weren't in the tropics, obviously, and I don't thing the baby ones travel that far extra-tropically, as the full sized ones occasionally do (especially in the South Pacific).


What you encountered does sound to me like a waterspout, either established or much more likely nascent or incipient, as others have said.

I don't know anything about them from first hand experience (touching wood with some fervour).

One of the boats in the 2001 Volvo was monstered by a waterspout in Leg 3 on the way to Hobart - I'm almost certain it wasn't the boat in the photo, but I forget which.

It sounded pretty unsettling. I remember one guy saying his sailing jacket almost got pulled up over his head.

[Jim Cate]

Originally Posted by Andrew Troup

I personally doubt you'll ever encounter circumstances like that again, at least not offshore. There are places (usually glacial fiords) where winds of that strength can change direction fast enough to pin a boat down - but that's because of the topography of the land.

I have encountered a mini tropical revolving storm which established quicker than we could furl sails, and it certainly blew a lot harder than 65 knots, but that took between half an hour and an hour to clock around 270 degrees in the course of passing over us... you weren't in the tropics, obviously, and I don't thing the baby ones travel that far extra-tropically, as the full sized ones occasionally do (especially in the South Pacific).


What you encountered does sound to me like a waterspout, either established or much more likely nascent or incipient, as others have said.

I don't know anything about them from first hand experience (touching wood with some fervour).

One of the boats in the 2001 Volvo was monstered by a waterspout in Leg 3 on the way to Hobart - I'm almost certain it wasn't the boat in the photo, but I forget which.

It sounded pretty unsettling. I remember one guy saying his sailing jacket almost got pulled up over his head.

Geeeze Andrew, I wish you hadn't posted that photo! That's about the scariest thing I've ever seen. We've been around a lot of waterspouts over the years, but they have been little anemic things compared to that monster.

Holy twister, Batman, I think Gotham city is in for it! And all nearby mariners, too.

Cheers,

Jim

[goboatingnow]

Sounds like a large cumulonimbus cell nearby. I've experienced what you describe near big thunderstorms. Wind is light then goes strong often large changes in direction common enough there in that area as such cells roll out of Africa.

Dave

[jeremiason]

Originally Posted by DeepFrz

Actually 65 kn is about 78 mph.

Your right and I should proof read before posting

[belizesailor]

Originally Posted by Jim Cate

Geeeze Andrew, I wish you hadn't posted that photo! That's about the scariest thing I've ever seen. We've been around a lot of waterspouts over the years, but they have been little anemic things compared to that monster.

Holy twister, Batman, I think Gotham city is in for it! And all nearby mariners, too.

Cheers,

Jim

Wow, that is by far the biggest beast of a water spout I have ever seen!

The pic I poster earlier, of one in Belize, is very much like all the others I have seen in Carib/Atlantic/Gulf of Mexico waters.

When I visit down under I think I will stick to the bus routes!

[Andrew Troup]

Originally Posted by Jim Cate

Geeeze Andrew, I wish you hadn't posted that photo! That's about the scariest thing I've ever seen.

Sorry, Jim, I forgot you were currently lurking in that neck o' the woods ...

If it makes you feel any better, (although I don't see why it would) this is about as big as they typically get over my side of the pond

They do seem to be getting more frequent, though - or perhaps it's just that everyone has a cameraphone ITDAA...

Anaemic would seem to be apt, although I'm still not planning on queueing up to make close acquaintance....

[carstenb]

http://www.cruisersforum.com/forums/...4&d=1352614013

I just hope to hell I never run into one like this! How the hell do you get away from it? I assume ti is moving much faster than I can sail.

[sctpc]

Steve change off Q, But how did your missus take it? The reason I ask is you told my story 2 years ago and she ant been out since and to be honest I still have the wind up when it gets squally.

mine was so powerful it took 3 of use to winch down the main.