Watching two waves

The tropics remain relatively quiet today. Franklin continues to barely struggle along, and a few modest tropical waves are moving across the far Atlantic. One of these waves, located near 9N 42W, shows some promise for development. It lies over farly warm 29C waters and has some favorable upper level winds over it. As long as the wave maintains its current west-northwest motion at 15 mph, it will stay over warm water and have a chance to develop. But as you can see from the SST plot below, any northward deviation to a latitude north of about 11N will bring it over waters less than 27C, which is the minimum temperature needed for tropical storm formation. A second wave near 12N 30W, just southwest of the Cape Verde Islands, showed some increase in convection the past few hours, and looks more promising than the first wave. However, this wave is very close the the cooler water boundary, so any northward component to its motion would dampen its chances of development. The wave is currently moving west at 10 - 15 mph. The GFS model doesn't develop either of these waves into tropical depressions over the next four days.





Dr. Jeff Masters