The presently warmest ocean water on the planet sits on the north margin of the tropical belt, at the top of the Indian Ocean, on either side of India. Its rate of evaporation must be very high, which would be consistent with water temperatures that are all up in the 30 degree territory:
What makes the very highest parts of this ocean especially interesting is the fact that large amounts of surface area regularly lack cloud cover and are thus exposed to full sunlight much of the time. Today is no exception. The same cloud-free situation is also true of a long stretch of more open water out in the Pacific at the same latitude and nearly as warm. This is not the kind of thing you see with so much regularity above any of the surface waters immediately to the south, which are more centrally located within the tropical belt. As we see in the image, their atmosphere is constantly building up large cloud masses that release prodigious amount of rainfall:
The precipitable water (PW) map is of interest because it tells us that something must be happening to prevent any sort of build-up in the cloud-free area, where values are in the 30-35kg category as compared with 50-55kg when massive clouds are present:
Why is there such a sharp contrast, so perfectly aligned? I think there is only one good reason: because of the positioning of all these waters along a border of the tropical belt, where they can be directly exposed to the overhead passing of jetstream winds, as described in my letter yesterday. The tropical zone interior is different by being consistently free of these winds. On a border area, when jet winds do sweep across the sky they will pick up freshly evaporated water vapor as quickly as it forms and is uplifted to an altitude of sufficient height. As vapor is continuously carried off there is simply not enough time left for clouds of PW to form in place, build up and become saturated:
This particular jetstream wind is a bit special. The bulky jet you see crossing India is following a pathway I wrote about recently in terms of only now becoming fully aware of its existence. I have identified it as the outermost of two separate pathways that are regularly set up within the red zone of each hemisphere. The innermost pathway, which means it is closer to the green-zone perimeter pathway, reveals itself with far more regularity and higher wind velocity. The next image, a view of the 500hPa air pressure configuration, shows how the lighter red portion of the red zone has considerable variations in width between the green zone and darker red. The isolated outermost pathway, innermost red-zone path and the green-zone perimeter all three come together a little way to the east as the light-red width narrows down, allowing the creation of what looks like a single fat unified jet by the time it reaches Korea. Some of the water vapor picked up over the Arabian Sea will eventually find itself precipitating deep in the heart of Siberia after it squeezes through a weakness in the green-zone perimeter in the area of the Kamchatka Peninsula and becomes part of the hook-shaped trail in the image above.
Carl