Lightning!

[Jim in TC]

Earlier this summer we had a couple situations where small cells of thunder storms popped up quite literally out of nowhere on Lake Michigan, and quickly moved east over our favored sailing area, Grand Traverse Bay. We were not on the water at the time, but the favorable forecasts from NOAA (until the storms hit - much closer to reporting weather than forecasting) would not have discouraged us in the least. Got me thinking...

What do you do if caught out in lightning without any preparation? What kind of advance modifications or preparations have you made?

I fully understand not going out in questionable weather, but the forecasts are not always suitable. And I understand heading back in at the first sign of adverse weather but our Sun Cat is not fast, and even under power we could easily be an hour or more from the harbor.

I do recall a trip some decades ago where a thunderstorm was bearing down on us and the skipper tossed a battery jumper cable in the water after attaching to a shroud. The storm dissipated before reaching us so the system was never tested. In another setting, lightning struck the lake all around us but did not hit the mast (so far as we could tell) on a larger cruising sailboat with a grounding plate on the keel. This is not a modification I would like to take on with our Sun Cat.

[Vectordirector]

Hi Jim,

Summer sailing is always a weather challenge in the midwest with the chance of thunderstorms popping up.  There are ways to mitigate the risk but weather forecasts are not totally reliable,  and the further into the future you go the less accurate they are.  I was an FAA Air Traffic Controller for 30 years and part of our training was a CWO rating.  That is a NOAA National Weather Service FAA joint rating as a Certified Weather Observer. 
I spent the first 7 years of my career in Kansas City at MCI, Kansas City International Airport as a trainee and then a certified tower and radar controller.  We had plenty of thunderstorms and I sailed a Hobie 16 there for 5 years.  Never got caught out in bad weather.  My training helped and continues to help me see storms building up as I constantly have my head on a swivel when sailing, just like I did working in the tower. 

I then spent the remaining 23 years as a radar controller at Chicago Terminal Approach Control.  We worked through all sorts of ugly weather much of it similar to what you get up at the other end of the lake.  I sailed in Lake Geneva, WI and saw many a storm build up over the farmland around the lake.  Some came up quickly and  I saw them and came in just in time a couple of times.   

I'm retired now and sailing in SW Florida year round.  So my way of dealing with the same thing here is to keep an eye on the sky and stay close to home.  If you don't know how to read cloud formations, take an online class or Coast Guard class on marine weather. 

Knowledge is king.  Sailing becomes much more stress free if you can read the weather, including getting a good weather forecast from a reliable marine source before heading out and knowing how to spot changes in the clouds and the wind that indicate that the forecast was wrong.     Often a wind shift will indicate that an approaching storm is usually about 10 minutes away.  The term "the calm before the storm" is a real thing and usually about 5 minutes before the rain hits. 

The other thing I find useful is my phone with a weather radar app like Weather Underground.  Learn how to read a weather radar and you can see how far away a storm is and if it is coming your way.  I rarely saw storms build up over the lakes but it does happen.   You can usually see them 15 miles away and check the radar to see if you need to take action.  That should give you more time to run into shelter.  In summer here in FL the storms come every afternoon.  Sometimes they hit here sometimes they miss by a mile or so.  I stay close to shore this time of year. 

If you get caught out in a storm, put the sails down, drop the anchor, unplug all electronics from the boat, hide in the cabin if you can and DON'T TOUCH ANY METAL IF YOU SEE LIGHTNING CLOSE. 

Those little microcells can be intense but they blow through in a matter of minutes.  I don't know how much water you have available but if you see a storm coming far enough away and moving toward you, you can sometimes sail perpendicular to it and it will go behind you.  sometimes.

Fair Winds,

Vectordirector

[Potcake boy]

                                                                                                         
                                                                                                                         ****WARNING****

Don't allow yourself to become a hand wringing weather worry wort. I've witnessed many sailing trips ruined or needlessly cancelled because of someone's exaggerated fear of their interpretation of the NOAA weather forecast. No better way to spread panic among fellow sailors than to proclaim "the sky is falling" because you are hanging on every computer generated word broadcast on the VHF weather channel.  I am not discounting weather awareness, but if you attempt to avoid any hint of bad weather, you'll not do much sailing. In addition to the informed remarks of Vectordirector, a good understanding of how to handle your boat in adverse weather is essential if you plan to venture more than 5 minutes away from your pier. I wouldn't knowingly sail into a weather disaster, but nor would I stay home fearing one.

Lightening is very scary, and I've yet to read any definitive safety measures to avoid being struck when on the water. I have read about grounding (the jumper cable trick), and the cone of protection, and other opinions, but none seem to stand the test of predictable results. Lightening strikes seem to be even more unpredictable than the methods of avoidance. There are some proven ideas like being inside a shell of conductive material like a car, but is it because the car is grounded or not grounded (rubber tires)? Using a ground point negates the electrical potential which invites a lightening strike, but standing under a tree is not advisable. Does a boat mast represent the same thing to lightening? Why does one boat in the marina get struck when all the neighboring boats get a free pass? It might be telling to have access to insurance investigations of lightening strikes. Here in SW Florida (lightening capitol of the country) we get some real laser beams. A week past I was standing by a window when a bolt struck a palm tree at the house behind. I felt the compression and electrical radiation. The house shook and the smoke alarms beeped for a few seconds. I got a real good boost of adrenaline and involuntarily uttered some sailor words. I went round to investigate and found tree debris over a 20 foot radius. The strike left the base of the tree and created a furrow through the grass all the way to the driveway where it exploded an area of concrete. It traveled from there under the driveway to the base of a carport support pole where it again exploded through the concrete leaving a foot wide upheaval. 

I agree with Vectordirector to shelter in the cabin. That may not be fool proof, but it feels good, like pulling the blanket over your head. Still, I prefer taking the risks on the water to the crazies on IH75.

P.S. our Com-Pacs use non-metallic through hull fittings which seem to help mitigate the risk of a strike. Seems may bronze through hull fittings grounded to an electrical grid get blown out with a strike, and so the boat sinks.

[Jim in TC]

I would not consider myself a weather worry wart; in fact the first mate would prefer I took weather more seriously than I do. That said, lightning still gives me pause. As stated before, these little cells that occasionally pop up out of nowhere tend to be small, and though sometimes have a hefty squall ahead of them usually blow out quite quickly.

I think the best strategies I have seen include a weather eye, a bit of relatively simple (cell phone) tech to keep track of weather and a retreat below if still caught out (anchor out if close to shore, hove to if in deep water). Cruising further off shore or to more distant harbors might dictate some more effective defense, though I am not sure exactly what I would do differently if we start venturing further out.