The Birthplace of Weather

April 6, 2019

Day 184

Noon Position: 33 39S  27 54W

Course(t)/Speed(kts): ENE 6+

Wind(t/tws): NWxN 14+

Sea(t/ft):NW 4

Sky: Overcast, amazingly complex sky

10ths Cloud Cover: 10

Bar(mb): 1017+, steady

Cabin Temp(f): 73

Water Temp(f): 70

Relative Humidity(%): 88

Sail: Working jib; one tuck in the main, close reaching on port

Noon-to-Noon Miles Made Good (nm): 129

Miles since departure: 25,125

Avg. Miles/Day: 137

Leg North Days: 172

Leg North Miles: 2,175

Avg. Miles/Day: 128

Tough night. Wind began to increase just as I started my sleep cycle (typical!). First one, then two, and then three reefs. I sat up with “the blow” and dozing in the pilot house till about 3AM, when things settled in at 20 knots from the NWxN.

More bang and slosh.

I put “the blow” in quotation marks because there was no change to the barometer and hardly any change to the sky. Just incrementally more wind as the hours passed.

Regarding the sky, not so by morning, when what the day delivered was a complex, ever changing mash-up of cloud, criss-crossed cirrus and towing cumulus. As I type, the sky if flat gray and raining.

And all the while, our northwest wind continues.

—

I think we are passing through a weather nursery.

You may recall that when Mo and I were making our way most recently through the Indian Ocean, I often wrote of what I called “Rio Lows,” low pressure systems that I noticed developing off the coast of South America at roughly the latitude of Rio de Janiero.

If they survived a few days in the lee of the continent, these Rio Lows would often wander off diagonally south and east, sometimes becoming powerful southern blows in their own right or joining up with an existing southern low to produce a whopper of a storm.

The knockdown in the Indian Ocean that took out Mo’s pilot house window was the result of a low that started its life off Rio.

Well, we’re here (more or less). This is Rio Low territory–where the low pressure systems are born. And I think this turbulent, confused, muggy, rainy, on-again, off-again weather is what the “birth of weather” looks like.

If true, I’m happy to report that it’s as messy and complicated as other births.

The below photo is from early this morning and is looking directly overhead. Notice that the ribbed cirrus clouds are traveling in at least three directions and that in the mix are both cirrocumulus and cirrostratus cloud. What more could you ask for?

This photo was taken at the *same time* as the above and shows a great wall of towering cumulonimbus directly in our path. This wall stretched horizon to horizon. Sadly, the photo doesn’t do its grandure justice.

And, by way of illustrating how fast things were changing, here’s a shot from ten minutes later.

The cirrus sky has been covered over by altocumulus and the wall of towering cumulus has simply evaporated.

But somehow we make our northing despite what the cloud does.