Microburst lessons learned

[JebLostInSpace]

I was in Newport, RI for a "microburst" that hit a few days ago. (Microburst in quotes because I don't know the official criteria to qualify an event as such, but that's what it seemed like to me, and what most people around here are calling it).

At least 1 boat sank, several were dismasted, anchors dragging, shredded sails, etc. I'm curious to get the forum's thoughts on the situation - warning signs that may have been missed, best practices to minimize damage in such an event, how to react to some of the things I saw, etc. I know Thinwater (anyone know how to tag him?) has some opinions on it since we ended up fighting about it in this post: https://www.cruisersforum.com/forums...ch-239058.html

Also, here's a news article I saw about it:
https://www.sailingscuttlebutt.com/2...ing-community/

I'll try to describe what happened from my perspective below, and looking forward to learning from the pros on here.

The weather forecast for the day was light winds (<10kts), overcast, and a chance (30%) of thunderstorms in the early afternoon. This seemed about right through the day, though the storms hadn't materialized by 6PM (ish, going from memory)

I returned to the boat from visiting friends on shore around 4 or 5, tied the dinghy off on the stern, checked on my anchor system for chafe, and went below. I was talking on the phone when I heard a clap of thunder. Poked my head above decks, but didn't see anything particularly threatening. Just a slightly darker seeming gray, but it didn't seem very different from what the skies had looked like all day (at least to my partially distracted, amateur eye).

While I was checking out the sky, a little rain started, so I hopped below to close the hatch I had opened for ventilation. A few seconds (literally seconds) after getting the hatch closed, it started to pour and the wind hit.

Because the winds had been light until now, the anchor chain was pretty slack, with the boat just riding easily to the weight of the chain. As the wind hit, the bow was blown downwind aggressively and the boat rotated around 120 degrees before the bow was caught up hard on the anchor chain. This put the boat beam to the wind when it caught, and I heeled over aggressively, probably just touching the lee rail in the water.

Next the boat swung back head-to-wind and settled slightly as the wind increased even further. I flipped my instruments on and donned foulies as quickly as I could. As I mounted the companionway I glanced at the instrument readout below and noted 53kts. This was the only time I looked at the instrument, and I think it was a little less than the full peak of the wind.

I scrambled forward to put eyes on the anchor line and convince myself I wasn't dragging. I use 2 snub lines made of climbing rope, one to each bow cleat as a bridle. (Thanks to the many posts on that subject in this forum that taught me how to do this properly) Thankfully, I was holding and both snub lines were intact, although one of them had a new chafe spot that hadn't been there when I looked earlier.

I scanned around the anchorage and saw 2 boats dragging near me. The first was downwind of me, what looked like a 30-something foot Catalina. The captain was already out and motoring against the wind to catch it. The other dragging boat was a large cruising cat upwind of me. Nobody was on deck when I first saw it, but I knew the couple was on board because I had seen their dinghy getting back around the same time as mine.

At this point I'm trying to think through how to avoid being hit by this cat if they don't get up and start motoring in time. This is the part that really haunts me. I had had a diver take my propeller off the day before. I was buying a new one, and the shop wanted to scan my current one to help with their recommendation on the replacement. I remember thinking at the time that being without a propeller was a bit of a risk, but decided I was too cheap to get a mooring or a dock for the days I would spend vulnerable. (Mooring balls in Newport go for like $75/night!) Now I was really regretting taking that risk as I watched this big cat drift down towards me. My only thought was to try to pay out more scope to buy time. I was trying to figure out how to let the two snub lines and the chain out together in a way that would minimize sudden impacts on the cleats, windlass, or my fingers. I'm still not sure if I could have managed it because at that point the captain of the big cat got on deck and fired up the engine.

They ended up catching it and motoring away from me with a mere 4-6 feet to spare. Phew.

At this point the wind started to abate. The article I linked above says it took about 3 minutes. It felt like an hour to me, but I guessed 5-10 minutes when I thought about it later on. I saw the big cat win their anchor and go to re-set it in another part of the anchorage. I then looked back at the other guy who had dragged and realized he was single-handing. Luckily his anchor re-set itself without having to pull it up. He was uncomfortably close to me at this point, but it did mean he was stable enough to start hauling the chain up without having to be at the helm every 5 seconds. He was hauling chain by hand, which looked like no fun at all in those conditions.

Next I went back to the cockpit and realized my dinghy had been flipped, with the outboard still attached. I righted it, but the engine had still had a good bath, and I lost the air pump that I had foolishly left in there unsecured. (I just straight up forgot it until the next day)

I also then had time to address the gennaker which had become partially unfurled and the leech shredded. (This was super sad. I had only recently managed to arrange the gennaker's attachment point on the anchor roller so that it could stay up while I raised and lowered the anchor. Until a few weeks ago, I would have had to store the sail below while anchored no matter what. Now I was wishing I'd never solved that problem).

As the wind fell off even further and the rain stopped, lots of people started coming around in dinghy's (dinghies?) to see if people were okay. One of them helped me wrangle the gennaker down on deck and stuff it in the bag. I'm sure I'd have managed on my own, but the extra hands sure were nice.

So anyway, there's my story. Lots of boats were out sailing and racing when it hit, which is where the worst damage occurred. It'll be interesting to hear from folks on what they would have done differently, practices I should adopt to avoid damage in the future, stories of similar experiences, etc.

[JPA Cate]

Pretty harrowing experience, all told, I feel for you.

I'd revisit the decision to not be berthed while without the prop. Even $700 (in retrospect) for a week or so on the mooring is small against the cost of losing the boat. We did have a situation where we could not use the engine because all the oil had come out. (Long story, but it was due to an oil hose chafing through.) Sailing onto and off of the hook is something you can practice, so that it becomes a familiar thing, and therefore less risky, and fortunately for us, we had done so. But even though we had practiced, it is kind of scary to try in a tight place, into 20-25 tradewinds. This is just a suggestion to develop a skill for the future, in case you need it. I would not try to leave in the middle of 60-80+ knots. Due to the fact that you might have to use the engine, best to stay somewhere safe till you get your prop back, imo.

When you furl your headsail, take two extra turns, so that you get the sheets wrapped around the roll, two times, then leave the furling line cleated off, so it cannot unwind. The sheets will help keep the sail secure, and it cannot unwind itself with the furler line secured. The sailmaker may be able to cut you a new leech. If it was an old sail, there may be a new one in your future.

If there were any microburst warnings, they would have come over the VHF radio. That would have been the clue to protect the dinghy. On our boat, we do that by securing our rib athwart the stern. We have cleats on each side of the dinghy's transom, and and secure it fore and aft to the mother ship's running back stay chainplate, and the bollard on the stern for towing the dinghy. It can't flip, then.

I've also seen dinghies tied for and aft, usually fendered, along the stern quarter, and that will also keep them from flipping. If only the painter is used, the wind can get under it and it will spin, throwing/dumping everything not secured out of it. Nice way to lose your dinghy anchor. Best secure it to hull.

Letting out more rode is somewhat tricky. Having a windlass makes getting up an anchor easier, but the middle of a microburst is the time to veer out more chain, not try and get under way. For us, we have all chain rode and an electric windlass, so we simply remove the snubber line, and fall back on the chain, then step on the down button and veer out some more, re-attach snubber line, and all is well. We use a single snubber line, and it goes over the roller with the chain. If you're using two separate snubber lines, see if you can add a snatch block on your side decks, and run
one of the lines back to the cockpit, to the primary winches. Then, you could ease, under control, if the snubber lines are long enough, and strong enough. When you've got out the length of chain you wanted to add, put the 2nd snubber on.

Ann

[JebLostInSpace]

Thanks for your thoughts on this, they are much appreciated!

I agree in retrospect that failing to berth while the prop was off was foolish. I'm still kept up at night thinking about that one. Probably safe to say I'll never willfully disable my engine while on the hook again. File that one under "thank goodness I was so lucky to have this as a valuable learning experience instead of a major disaster"

I like your suggested method for veering out additional scope, using a long snub line led aft to keep the pressure off the windlass. However I'm not sure how I would remove the snub lines (one of them anyway) in the beginning of that process. My current system is to tie each line onto the chain, let out chain until happy with the snub length, cleat off snub lines, then put slack in the chain. This puts the end of the lines about 20-30 feet off the bow, in the water. To detach them I normally have to pull chain in via the windlass until the knots are aboard, but doing so in such high wind seems... challenging. I guess I could just cast one off and leave it in the water attached at the chain end, but then I have a line in the water to foul my prop...

For the dinghy, I actually have davits, so if I had been expecting weather I could have just hoisted it out. The problem was that I didn't expect it, and wanted to be able to easily go ashore later that night (was maneuvering for a tinder date that sadly didn't happen). Then again, hurricane prep advice I've read is to take the dinghy off the davits to reduce windage. I certainly wasn't expecting a hurricane, but we did get very nearly hurricane force winds...

On the headsail, I did have a couple of wraps in the sheet. Trouble is this sail doesn't furl particularly tight and tidy. Once a bit if the leech near the top caught the wind, there was enough force to stretch things out and free the rest of the leech. I do normally strike it below decks before a storm, but again I didn't take my normal storm precautions for this unexpected event. The sail maker does say he can fix it though, so there's that.

Lastly, I didn't hear any warnings over the VHF. I suspect there were none, but I'm also not in the habit of keeping the VHF on while anchored. I've found there's enough chatter always on it that I tend to tune it out even if it's on. Do most people continue to monitor VHF through the evening at anchor? Overnight?

[Westcliffe01]

A microburst is a very strong downdraft (falling wind) that impacts the surface vertically. On land you will see trees splayed out in a radial pattern from where the center of the downdraft hit. This is what makes it different to straight line winds or storms having circulation (supercells, tropical storms, Hurricanes etc). They can clearly strike without warning because it is coming down at you as opposed to across the landscape, although once started its possible that it may then follow some sort of line depending on where the thunderstorm that spawned it is going.



It is a phenomenon that is particularly dangerous to aircraft either landing or taking off because the decent rate is usually beyond the capability of the airplane to climb. President Reagan was in airforce 1 and flew into a microburst and things came very close to him going to the "happy hunting ground"... After that incident, the japanese scientist who had theorized about these phenomenon and about the possibility of weather radar got a grant to start building out the weather radar network and the rest is history.....

[Palarran]

If your on the water long enough, you will get caught in something like this. I was bummed out about about my boat getting caught in a straight line wind 4 days ago in Michigan. Thank goodness it was insured.

[BigBeakie]

My wife and I were in a microburst in our Zodiac dive boat many years ago off Crowdy Heads, and we did see the virga at quite a distance from us. The wind was still ferocious for a couple of minutes and we were glad the boat was full of tanks and weight belts to keep us from flipping over.

In our Heavy weather meteorology course, we looked at photos of microbursts.
If you're lucky you may see a wispy vertical shaft of rain or darker grey cloud extending down from the bottom of low nimbus cloud. That is called a "virga" and can be a warning that dense cold air is about to fall down from high altitude. When it hits the sea surface it fans out horizontally and knocks you over. The air mass can fall through the cloud at 100 knots.

Keep an eye on the CAPE index of any weather in your area. High CAPE values are indicative of very turbulent air movement, one result could be falling microbursts. Also the cloud type cumulus mammatus or "cows udder" clouds also signal high atmospheric turbulence.

If you see virga forming, drop all sail immediately, start your engine and turn toward the virga to take it head on. You've only got a very short time until a wall of wind hits you, depending on how far you are from the parcel of rapidly falling air.

If it happens at night.....you're stuffed.

[rslifkin]

Dinghy lifted in davits is more windage, but the extra windage is all the way aft. So at least it'll help keep the boat pointed to the wind better, rather than getting blasted sideways. Depending on the weather in question, that might actually lead to less load on the anchor rather than more.

[Franziska]

Hi, that surely was one of the less pleasurable events in a cruising life.
I feel for you.

Here are two very impressive videos actually showing a microburst in action:

https://youtu.be/a_G2KRzha7o

https://youtu.be/ObYRYF3d38Y

[thinwater]

Originally Posted by Franziska

Hi, that surely was one of the less pleasurable events in a cruising life.
I feel for you.

Here are two very impressive videos actually showing a microburst in action:

https://youtu.be/a_G2KRzha7o

https://youtu.be/ObYRYF3d38Y

Very cool.


Twice I have been on the edge of one, with areas of trees flattened nearby.


The lesson to me, is that there is no time to do ANYTHING, other than duck. You need to be anchored for extreme weather anytime thunderstorms are likely, because you won't have time to do a darn thing.



The first time I was anchored with a Fortress and Danforth anchor in a V. It felt like a monster was tossing my cat around and it took considerable time to recover them in the morning. The second I had a Fortress and Manson down, and again, the Fortress was a beast to recover. Both time were in very soft mud, the reason for 2 anchors, but obviously, the Fortress reached good mud. I was lucky. I only very rarely use two anchors for wind. In both cases I was in a protected cove and I just did, because I didn't like the bottom, I guess, and I didn't like something about the weather. Still it felt like luck. In both cases, however, it was clear something was coming the last 15 minutes, which was enough to get everything on deck secured and the dinghy up.



In both cases, the time from the first gust to over 60 knots was only a few seconds.

[JebLostInSpace]

Can you give a bit more detail about what warning you saw in the 15 min leading up to those events? I was down below in this case, but it would be good to have an idea of what the leadup looks like for the future

[NPCampbell]

I posted last year about a cruise liner, the Norwegian Escape, being hit with winds from a microburst which leaned it over 45 degrees.

Atmospheric conditions that are suitable for microbursts can be predicted but the microbursts themselves will typically occur without warning.

I'm a fan of catamarans (but have no experience) and this is where I think they have a tough time. They need to reef to max wind conditions (vs average conditions for a mono). When sailing through squalls, if a microburst occurs, unless you are reefed to minimum sails, how do you de-power quick enough to save your boat?

[JPA Cate]

I like your suggested method for veering out additional scope, using a long snub line led aft to keep the pressure off the windlass. However I'm not sure how I would remove the snub lines (one of them anyway) in the beginning of that process. My current system is to tie each line onto the chain, let out chain until happy with the snub length, cleat off snub lines, then put slack in the chain. This puts the end of the lines about 20-30 feet off the bow, in the water. To detach them I normally have to pull chain in via the windlass until the knots are aboard, but doing so in such high wind seems... challenging. I guess I could just cast one off and leave it in the water attached at the chain end, but then I have a line in the water to foul my prop...

For the microburst situation, without a 2nd anchor to deploy, you'll be on the beach again, and you have already recovered from the on the beach situation, with all your lines intact.

Thinking about what Thinwater wrote, that any thunderstorm situation may give a microburst situation, you should always anchor as if you'll have to contend with one if thunderstorms are about. In our case, we use a chain hook, so Jim pulls up some chain so he can shake the hook off. With practice, you can gauge this to about 3 links. So, the snubber comes off quickly. You may want to think up a different way of doing your anchoring so that you can quickly release more rode. I really don't know how this works with rope rode. Only that you need a lot more scope than with chain. It also will depend to some extent on the bottom you're anchored in. We anchor in places where coral grows, and rope rode would quickly chafe through in coral.

Thinwater also mentioned using two anchors. One thing you could to is keep a Fortress [for its ease of handling] on the foredeck, with rope rode for it in a self draining deck bag, with the bitter end secured to a cleat, and the other end to the anchor. (If you need more room on the cleat, use a soft shackle through it, and secure the bitter end to that.) Then, while dragging, you could chuck the Fortress over, and it will eventually stop your dragging. If you're able to keep the line on the horns of the cleat, it will go out and you'll feel it try to set. Then let out *some* more, so it has a little more scope to work with, and cleat it off. We have a 20 lb. HT Danforth that we use when we need to make the "V". Ours lives in the lazarette, and we have to lug it forward along with all the line. But, it has been very useful. You might be able to find one used. Do get the HT [high tensile], if you choose not to spring for the Fortress. We've used ours mostly as a stern anchor and as a sort of kedge, to hold us off something we didn't want to swing into.

Because the wind strengths are so huge, the windage of the dinghy in davits should be avoided. If you just keep the dinghy attached to the uphaul lines for the davits, will it stay tucked behind? I think your dinghy would be better off in the water. Figure out ways to secure what you need in it, or stow them on the mother boat, fore and aft. [It is possible to bond an eye onto the stern tubes, and put a stern line on that way, if it is an inflatable dinghy. It needs quite a large patch, to spread the loads, comparable area to the one for the towing eye.]

VHF practices at anchor vary. We have been told that since it is us who are there on the water, and possibly the closest responder to an emergency, we should keep it on all the time. In very isolated places, this seems to be a responsible approach. You only keep your attention tuned for "Mayday", and tune out the rest, except for "Securite," and whatever follows, like "emergency storm warning," stay on 16, don't scan. This works okay for us in the daytime. At night, we turn it off when we sleep. This is sort of indefensible from a public welfare pov, and I guess we're not as good citizens as we might think we are. [There are times when it would be too dangerous to go help, also.]

Ann

[Franziska]

Ann, regarding the Fortress as savety to be thrown over board when dragging, by my experience you need to attach at least 10ft of chain an à lot of rope onto it. It needs to be fully on the ground before the rode starts to pull.
They have great holding power and are easy to handle, but due to the light weight they have a hard time to reach the bottom when they are pulled before reaching ground.
We had that happen once, the Fortress flew like an underwater kite, as it did get pulled before fully reaching the bottom.
Just something to be aware of, we had that happen.

If the bottom is suitable, I'd probably throw the main and Fortress out first and have the second main anchor ready to deploy as reserve on deck.

Fran

[Cheechako]

Had it happen early am in Florida once. From dead calm to wind over 70 mph in minutes.(anemometer was pegged). 180 degree anchor direction change. I was standing in my skivvies at the wheel with the engine full open in gear after jumping out of bed. I thought someone had hit us with a bang. Spouse handed up the ski goggles because the rain was literally horizontal, hurting the face and eyes. Eventually the main anchor pulled the sea bottom up and we dragged toward shore even with full engine power. Just in time I literally threw a Fortress anchor over and it caught! Saved the boat.
Nearby two 18 wheelers were overturned on the freeway.
Other boats were dragging all over the anchorage.

[thinwater]

Basically, what PDA Cate said. You can see the conditions that make it possible (a tall cloud with the potential for strong vertical circulation,) but you can't know how it will play out. Some scary clouds are lambs, and some modest fronts blow your ears off.


As a result of mistakes spread over 40 years, I have learned two rules:

a. Forget sailing around squalls that have serious height. Even if they don't knock you flat, they can tear a sail, so is it worth it? Nope. Bare poles, get some sea room, and relax. It won't last.

b. Anchor like you expect 60 knots every night in TS season, if there is any prediction. Yes, it's a pain. And it is so sweet to hear thunder and KNOW that everything that can be done, has been done, and you can just enjoy the show. Knock wood, I've never dragged in a TS, because I am always seriously anchored. The two times I dragged a little it was only 15-20 knots and daylight (I had old school crap, undersized anchors that came with new-to-me boats)!