© Weather ChannelCurrent Infrared Satellite Image
The highest cloud tops, corresponding to the most vigorous convection, are shown in the dark red and pink colors. Clustering, deep convection is a sign of a developing tropical cyclone.
A pair of Pacific tropical systems is about to begin a bizarre, circular dance known as the Fujiwhara effect, generating high surf along the Southern California coast just days after a similar interaction involving separate tropical cyclones in the western Pacific Ocean.
Hurricane
Hilary and Tropical Storm
Irwin, are, fortunately, no threat to Mexico's Pacific coast.
Their centers are now sufficiently close - about 600 miles apart - that a phenomenon meteorologists call the Fujiwhara effect kicks in.
Named after a Japanese researcher who discovered this in experiments with water in the early 1920s,
the Fujiwhara effect details how two tropical cyclones less than 900 miles apart rotate counter-clockwise about one another.Think of the
teacup ride at Disney or the Tilt-a-Whirl at your local county fair, but with tropical systems instead. In the teacup ride, adjacent teacups can not only spin, but revolve about each other.
In this case, Irwin, the westernmost storm of the pair, has temporarily stalled, but will soon get pulled north and will revolve counterclockwise around the circulation of Hilary this weekend, according to the latest forecast guidance.
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