Tropical Storm Sean has about a day left to become the season's seventh hurricane before weather patterns blow it away.
- Tropical Storm Sean on the morning of Thursday, Nov. 10, 2011. (NOAA)
If Tropical Storm Sean, currently lurking far off the East Coast, wants to become a hurricane it better get on that soon. The storm is sitting on water that is just warm enough to give it some kick, and the wind shear has not yet picked up enough to blow its top off. But a trough zooming over the United States will convene with Sean in the next day or so, moving it far into colder northern waters. That will effectively slam the storm's gear into extratropical transition, and it's goodbye to Hurricane Sean.
Want to know what propels storms like Sean? A vast natural "engine" in the core of the system provides much of its oomph. Swirling winds near the eye wrap warm air into immense corkscrews that reach higher than the realm of jet liners. These so-called "hot towers" distribute energy through the system and allow storms to intensify into hurricanes. Here's a good hot-tower explainer from NASA:
While Sean's screaming winds are too far off to be heard in the U.S., they are having an effect on us land mammals. There are High Surf Advisories up and down the Florida coastline for "long-period ocean swells," energetic upsurges driven by strong winds, pushing waves as high as 7 feet onto beaches. The turbulent waters are eroding beaches and pumping up the risk of dangerous rip currents near "groins, jetties and piers." Only the foolhardy would swim in these bone-crushing breakers.