Hurricane Lane, which reached peak intensity early this morning as a rare Category 5 hurricane over the Central Pacific, has weakened to a Category 4 hurricane this afternoon but remains a very powerful hurricane. Lane, the strongest Central Pacific hurricane since Ioke in 2006, continues to pose a serious threat to the Hawaiian Islands even if the center of the storm does not make landfall.

Lane a Category 4 but still very powerful

As of 11:00 a.m. HST (5:00 p.m. EDT) Wednesday, Hurricane Lane was centered near 15.5°N 155.9°W, and was moving west-northwestward at about 8 mph. Maximum sustained winds were 135 knots (155 mph), with an estimated minimum pressure of 935 mb. This is down from the hurricane’s peak intensity earlier today, when it was a Category 5 hurricane with maximum sustained winds of 140 knots (160 mph) and a minimum pressure of 922 mb. Lane is not as symmetric as it was last night, indicating that wind shear around the storm has likely begun to increase. Regardless, Lane remains a very dangerous hurricane, and interests in the Hawaiian Islands should prepare for the hurricane as it makes its closest approach between late Thursday and early Saturday. Models still disagree over the exact track Lane will take, and this remains uncertain. The 12z Wednesday GFS model run predicted that Lane would make landfall in Maui as a weakening tropical storm Friday afternoon local time. The 12z Wednesday ECMWF model run is farther west than the GFS, and keeps the system just offshore Oahu and Kauai late Saturday. Lane’s impacts extend well from the center, so even if Lane does not make a direct landfall, significant impacts are likely. Lane is likely to gradually weaken during the couple days as it moves northwestward and then northward. Though wind shear is currently not too strong, the shear is expected to quickly increase to above 40 knots in about 72 hours, and this should quickly weaken the hurricane as it approaches the Hawaiian Islands. Even if Lane does not produce hurricane force winds on any of the Hawaiian Islands, heavy rainfall of 10-20 inches is possible across the islands. Preparations should be rushed to completion, as impacts are likely to begin on Thursday.

A Hurricane Warning is currently in effect for Hawai’i (the Big Island) as well as Maui (including the islands of Lanai, Molokai and Kahoolawe), and a Hurricane Watch is in effect for Oahu, Kauai and Niihau. The last hurricane to make landfall in Hawaii was Hurricane Iniki in 1992, which struck the island of Kauai as a Category 4 hurricane while moving northward. There have been several recent tropical cyclones to come very near the state, though all of them weakened before landfall or missed landfall entirely.

Unusual Atlantic August lull may end soon

The tropical Atlantic, which has been very quiet during the month of August, is likely to begin to become more favorable by next week. The Atlantic basin so far has seen no tropical cyclones form south of 30°N this month, as well as no hurricanes during the month so far – the first time since 2013 that the Atlantic has gone the first three weeks of August without a hurricane. A tropical wave is expected to exit Africa by tomorrow night and emerge into the eastern tropical Atlantic. The National Hurricane Center (NHC) currently gives this wave a near zero percent chance of development within 48 hours, and a 20 percent chance within five days. Currently, global models show no development with this system in the imminent future, though environmental conditions might gradually become more favorable as the wave tracks westward to west-northwestward. We are now in late August, and are nearing the climatological peak of the season, so this wave will need to be watched even if models are not aggressive with development at the moment. After this wave, global models are indicating the potential for a few more strong tropical waves to emerge from Africa as we head towards September. The next name on the Atlantic naming list is Florence.

I will be back with an update on the tropics tomorrow.