Storm Cell

Peregrina's Journey
Peter and Margie Benziger
Tue 15 Jul 2014 16:15


It was late for Peregrina to be making the transatlantic crossing from Africa to the Caribbean. The official hurricane season had already begun.  Most of the world cruisers were far ahead of us and safely tucked into their berths or up “on the hard” on the island of Trinidad which is known as a safe haven for boats because of its location slightly below the probable route of most hurricanes.


Our passage was from Ascension Island to Ile De Salut in French Guyana - home to the famous French prison in the movie, Papillon, with Dustin Hoffman and Steve McQueen.  We started out from Ascension Island on June 12 heading north by northwest.  The passage is approximately 2,400 miles long and would cross the equator passing through the ITCZ (inter-tropical convergence zone) leaving the Southern Hemisphere and into the Northern Hemisphere.


The ITCZ, is the equatorial trough more commonly known as “the doldrums.”  In his book, World Voyage Planner, Nigel Caulder writes:  “Although the doldrums have earned their reputation because of frequent calms that could delay ships for days on end, doldrums weather can sometimes be particularly unpleasant, with violent squalls and raging thunderstorms.

We were about to find out.


When we passed the equator, I was lucky enough to snap the following photo when our latitude was zero. This is actually not that easy since numbers change about every second.




Our grib weather files, which show wind predictions, forecasted a steady 15 knots of breeze but there was a low pressure system forming directly ahead of us. In general, the sailing was great but, increasingly, small dark rising cumulous clouds appeared.  As these clouds, with dark bottoms, passed over us, we experienced increased wind and some rain but they were manageable.  Up until that time, we had been sailing “wing and wing” with the mainsail on one side and the genoa poled out on the other.



This sail combination was working quite well except for the fact that large steep waves were hitting our beam and rolling the boat back and forth on its sides. With the big rolls, the mainsail (attached to the boom) would be thrown to windward and we could feel a sharp jolt as the boom preventer brought the movement of the boom to a sharp halt to avoid a jibe.

 

However, the it finally happened.  The nylon strap connecting the boom preventer to the bollard on the foredeck snapped and we did a full crash jibe. This means that the 17 foot boom went from one side of the boat violently to the other.  Thankfully, I did not have the running backstay on. The flying boom would have ripped the running backstay off the boat.  When the boom jibed onto the other side of the boat it did so with a loud jarring crashing sound and the boat heeled violently over. I was down below but I knew immediately what had happened.  After examining the boat for damage, I found the only breakage had been the boom preventer webbed line which had snapped.


A crash jibe is something that leaves a distinct taste of bile in your throat and a nauseous feeling in the pit of your stomach. We, therefore, decided to proceed with just our large genoa foresail poled out and no mainsail.  Using just a poled out headsail is actually a great downwind sailing configuration since the center of pull is well forward and there is no danger of the mainsail and boom crash jibing.



The incidence of storm cells was becoming more frequent and the size was concerning us.  A storm cell  can be as simple as a low level cumulus cloud that has air rising in the center and rain falling. In front of the cloud, along both sides and in the center the winds can change dramatically in velocity as the exterior air is sucked towards the air rising in the cloud’s center. Often the bottom of the cloud is dark.  These storm cells can be isolated and small or extremely large.

 


In general, during the day, it is easy to see these clouds and to estimate whether they will pass over you or will pass a safe distance away.

At night, we count on the radar since the falling rain in these clouds is seen as a somewhat solid mass by the radar which paints the rain yellow.  On Peregrina, someone is always on watch.  At night, we keep the chart plotter on split screen so that we can see both our course and the radar images. Here is a picture of a just two small storm cells which are not particularly threatening in size.



Margie had the 10pm-2am watch. About mid-night, she called me using her whistle. We both wear red whistles on lanyards around our necks since they be heard much more clearly than yelling. They are also much better in attracting attention if you fall off the boat.  The radar showed a large storm cell approaching.

We decided to reef down to half the genoa size with no mainsail which, based on several previous storm cells, would be sufficient.  We were wrong!


During the last mile of its approach, the storm cell seemed to grow in size and intensity.  The winds began to increase extremely fast rising from 20’s to 30’s to 40’s and topped out with the highest gust at 55 mph.


Now, when the wind is that high and directly behind you, it is hard to reef the genoa since the wind pressure on the sail is intense.  We had waited too long. The boat was accelerating rapidly and began to surf down the front of the waves. Our comfortable SOG (speed over ground) at night is about 6 knots.  We hit 7 knots, then 8 knots, then 9 knots, then 10+ knots. Luckily, I had put both running backstays on when we lowered the main as the standing rigging was literally vibrating like a cello string.


Often the wind is highest in front of the cloud and only a bit later does the heavy rain hit. Now the rain came and we did not have on our foul weather gear.  We did have on our PFD (personal floatation devices) and harnesses.  When the rain hit, it did so with a vengeance. The canvas dodger (5 years old) over our heads started leaking water directly onto our chart plotter and autopilot instruments which was a concern.


During these types of storms, the boat must be turned constantly so that the wind hits the poled out foresail at the correct angle which means you must take the boat off auto-pilot and hand steer. Margie did a great job of constantly maneuvering the boat as the wind direction changed.


Once we entered directly under the cloud, the wind velocity started to fluctuate wildly, decreasing rapidly and then increasing rapidly again.  We waited until the wind started to fall and then pulled in much of the remaining foresail.  We literally now had a “handkerchief” of sail up and our speed was still almost 9 knots.  I started “Hercules,” our mighty diesel engine, to have him warmed up in case of an emergency and put the boat in slow forward gear to increase directional stability.


The difference between this storm cell and others was not only the intensity of the wind and rain but the duration.  Often these clouds can pass in 20 minutes but this one was HUGE.   On radar, when the rain is beginning to decrease the yellow color will diminish in intensity and some gaps will be seen.

 

This was what our radar looked like for over two hours. Each ring is one nautical mile.



By now we were both soaked and starting to shiver. Finally, during a lull in the wind, we did get some foul weather gear on but it was soon soaked right through.  We have six year old foul weather gear with a lot of hard, wet miles on them which, obviously, need to be replaced!  Below decks things were not going well either. A lot of cushions, clothing, books, dishes, etc, etc, had decided to go “walk about” and land on the floor.


Finally, the radar showed the end of the storm cell and the wind backed down to a manageable level.


Wet and cold, we were both looking forward to spending some time in the warmth of our dry bunk but that was not to be…

One of the side portholes, above the bunk, had been closed but apparently not dogged down (latched).  The wind blew it open and our bunk was completely inundated with water along with all the pillows.  UGH!!!!  We’d have to use the small, much less comfortable, berth in the settee of the main salon.

 

So, one after the other, we went below to towel off, change into dry clothes and use the head (toilet).



Oh, I forgot to tell you that our head broke two weeks previously and we were using a blue plastic bucket.


 Ain’t that a pisser?

 

 

  (Margie informs me that that is probably more information than you need…but I want you, dear readers, to have an honest view of life at sea!)

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