The CAG, the Monsoon Trough, and Pacific Hurricanes
There is something I have been monitoring this season, mostly because it has stood out in the nhc tropical discussions.
The monsoon trough is the space between the easterlies of the northern tropics and the Intertropical Convergence Zone(ITCZ). This is an area of surface convergence and it can influence wind speeds and wave state.
This year the monsoon trough in both the Atlantic and Pacific have been unseasonably north of their usual positions. This has led to light winds and low churn along the Mexican and Central American coast.
This is notable, especially as it affects the hurricane birthing zones for the eastern pacific. There have been unseasonably light winds in the Gulf of Papagayo. This means water takes in more heating than if the water was really churning well.
Furthermore, this is an upwelling area, all west coast regions in the northern hemisphere have upwelling. Upwelling is where deep pacific waters push cooler water to the surface.
So I don’t know what the effect will be ultimately, but it stands to reason that the cool upwelling waters are being warmed more than usual because of the light winds and low churn.
You might notice an invest area today just north of the Gulf of Papagayo, and another just east of there as the CAG discussed in the last post seems to be more organized over Belize.
The CAG is also keeping that pacific monsoon trough unusually far north, now pushing it into the Gulf of Tehauntepec.
I dont know what the overall impact of this would be, but I do find it intriguing.
From:
https://www.nhc.noaa.gov/text/refresh/MIATWDEP+shtml/160927_MIATWDEP.shtml?
https://www.nhc.noaa.gov/?epac
“The monsoon trough is displaced farther north than usual due to the ongoing Central American Gyre. It now extends off the coast of Mexico near 17N99W to 12N118W to 08N125W. The ITCZ extends from 08N125W to 07N140W. Numerous moderate to isolated strong convection is noted from 12N to 16N between 92W and 98W. Scattered moderate convection is noted from 09N to 16N between 85W and 111W. “
