Tropical Waves

Heavy tropical rain
A squall going through the anchorage, June 2014
washing the decks in the rain
Our neighbours take advantage of the early
morning rain to scrub their deck

The wind picks up a little causing the windscoop to flutter slightly, at the same time the tiny patter of light rain sounds on the deck. The crew, down below listening to the morning net or browsing the web or eating breakfast or all three, become strangely alert for signs of the wind picking up or heavier rain. As the pattering becomes a drum beat and the wind raises a howl in the rigging the pair of us fall over one another in a rush to close the portholes in the topsides and the main hatch to avoid flooding bookshelves or a soaking for the saloon upholstery.

Tropical waves are not something that happens amongst the crowd at a cricket match. Otherwise known as Tropical Disturbances or Easterly Waves (the latter because they travel east to west on the Easterly Trades), these low pressure troughs travel west across the Atlantic from Africa bringing cloudy conditions. Sometimes they become more organised; the precursors for a Tropical Storm or Hurricane. So something we cruisers keep a keen eye on. For the residents of the Eastern Caribbean this low pressure also brings welcome rain. Much like the Pennines in the UK further north the mountains of Grenada force the incoming Atlantic cloud up in turn causing the moisture the cloud carries to fall as heavy rain. Little wonder much of this mountainous tropical island is covered in rain forest.

The rainy season seems to follow a pattern mostly depending on whether one of the numerous waves is passing over. Down on the coast our experience is of occasional rain on and off for the morning, rarely does it continue into the afternoon. Most often though rain falls solely during the night drying up soon after dawn. Always a light shower precedes the main squall, a warning to get up and close any open hatches. This morning was no exception, however the squall quickly passed leaving a grey and overcast prospect, a sort of odd twilight never otherwise experienced in the tropics where the dark of nightfall almost instantly follows sunset.

Before the portholes can be opened to allow cool air to below there is more pattering on the deck then silence. The wind gently plays with the rig, we wait, hot and sweaty for the squall but nothing falls immediately. Life goes on in the humid heat, today’s island forecast is for sunshine this morning, showers in the afternoon and more rain for the rest of the week but whether the south coast will get the rain is another matter. To the north of the bay Grenada’s mountains are swathed in grey rain clouds almost down to sea level.  The anchorage is almost completely still, Temptress swings at odd angles, sporadically rolling on the wash of a passing dinghy, bereft of the usual Easterly Trade that keeps her bow pointing to the eastern cliff. By 9am the sky is brightening slowly; high level, pale yellowy grey cloud prevents the sun breaking through completely. Gradually the valley view at the head of the bay reappears though the mountains remain cloaked in rain cloud; time to open the portholes and relax until the next subtle warning patter of raindrops on the deck.

Squall over Prickly Bay, Grenada
Another squall last month – no mountain view!