A third tropical cyclone of the season is bringing significant impacts to Hawaii.
A third tropical cyclone of the season is bringing significant impacts to Hawaii.
Hurricane Lowell has brought heavy rain, strong winds, dangerous surf, and even a tornado threat. The Tornado Watch issued for Kauai County was the first for the state since 2000 and has been widely reported as Hawaii’s first-ever tornado watch—an extraordinary statistic.
Lowell took an unusual track, passing west of Niihau and Kauai before curving north. That placed Kauai in the storm’s front-right quadrant—typically the part of a Northern Hemisphere hurricane most favorable for tornadoes.
Winds naturally change speed and direction with height around a hurricane, creating wind shear.
This wind shear has a tendency to rotate thunderstorms embedded in rain bands, commonly spinning up tornadoes.
On the storm’s right side, the hurricane’s forward motion adds to and compounds its rotating winds, strengthening that low-level shear.
Tornadoes are fairly uncommon in Hawaii compared with much of the mainland, but Lowell’s unusual track created a rare setup favorable for them.
