After taking a little time to recover from our Costa Rica Nightmare, we raised anchor in Playa de Cocos at 7 p.m. yesterday evening to resume our passage northward, the destination of this leg being Puesta del Sol, Nicaragua. If you have been following this blog since Spring, you might recall this is where I left Intermezzo to do a three week land tour of Nicaragua in April and where my daughter joined me at the beginning of May to sail to Costa Rica.
It's now Thursday morning (Renee's birthday!) We are about half way to Puesta del Sol. The passage has been calm and peaceful. We enjoyed two hours of quiet sailing under the Code 0, but the rest of the time it has been motoring with the engine chugging along at relatively low rpms.
As with a lot of things related to sailing in new places, I am learning about tropical weather patterns as I go. I have been reading weather synopses for this region, but it has been a bit of a learning curve to understand how the Intertropical Convergence Zone (ITCZ) and the Monsoon Trough relate to our local weather conditions and to draw a mental picture of where these two phenomena are located relative to our position based on a few latitude/longitude coordinates provided in the offshore weather report. But I finally think I figured it out.
The ITCZ is where winds from the equator and the subtropical high pressure to the north converge. This convergence results in the doldrums, where there is little or no wind and convection in this zone is one of the reasons for the thunderstorms we have been experiencing. The Monsoon Trough is associated with the ITCZ and is a line (usually not a straight one) of low pressure.
The Monsoon Trough is what has been affecting us the most. It is currently located between 8 and 10 degrees north latitudes. The difference and gradient between the high pressure areas to the north and south of the trough determine the strength of the winds. The pressure gradient towards the equator has been steeper than the pressure gradient to the north. Thus, when were south of the trough in Panama, we experienced the strong southwest-west winds that resulted in the spirit-sucking bash, bash, bashing. Now that we are north of 10 degrees latitude, in a much more gentle pressure gradient, the winds are much lighter resulting in calmer seas. If I had figured this out sooner, I would have known there was a light at the end of the tunnel while we were bashing our way northward.
From here to Mexico, the weather we need to watch carefully are the Papagayo winds. These winds originate in the Gulf of Mexico, crossing a narrow isthmus in Costa Rica-Nicaragua and blowing down the mountains into the sea from the east. These winds can be very strong, typically in the winter months. For us, it looks like we will get some good Papagayo winds this weekend,19-25 knots from the East-Northeast, which should make for a great beam reach sailing to Puerto Chiapas. That would be a great way to wind up the last leg of our journey.