Hurricane Iselle is closing in on the Big Island this morning as the 80 MPH hurricane rapidly closes in on Hawaii. The entire state, home to nearly one-and-a-half million people, will see life-threatening weather conditions as the hurricane moves through over the next 24 to 36 hours.
Forecast Track, Watches, and Warnings
Here's the latest complete advisory from the Central Pacific Hurricane Center in Honolulu, which is responsible for forecasting Pacific hurricanes between 140°W and 180°W. For reference, Hawaii is six hours behind Eastern Daylight Time and three hours behind Pacific Daylight Time.
The hurricane is still expected to make a direct landfall on the Big Island (Hawaii) late tonight or very early tomorrow morning as a hurricane with winds between 75 and 80 MPH. The rest of Hawaii's populated islands — including Oahu, where nearly 70% of Hawaiians live — will likely see an extended period of tropical storm force winds, heavy rain, high surf, rip currents, and possibly a few tornadoes tonight through tomorrow as Iselle sweeps through.
A band of showers starting to approach the Big Island right now out ahead of Iselle. The main clouds from the hurricane aren't even near land yet, but as the storm is moving at nearly 20 MPH, that will quickly change through the day today.
Once the hurricane starts approaching land, we'll get a better view of it with Hawaii's four Doppler weather radar locations (respectively, from southeast to northwest): PHWA (southern Big Island); PHKM (northwestern Big Island) ; PHMO (Molokai); and PHKI (Kauai).
On Iselle's current trajectory, it looks like the eastern side of the Big Island will take the brunt of the hurricane. The strongest winds will occur around and north of where Iselle's center makes landfall. Hilo is in a bad spot right now — it looks like the city could see the worst of it (and if not the worst, pretty close to it).
The rest of the islands that are under the tropical storm warning can expect to see an extended period of winds between 40 and 70 MPH, with stronger winds likely on the windward (in this case, eastern) side of the islands.
Iselle will generally produce 6 to 7 inches of rain across the islands, with more at the windward base of higher elevations and less on the leeward side of terrain. This much heavy rain falling in a relatively short period of time will lead to flash flooding and the potential for mudslides. Residents should heed flash flood warnings and evacuate areas prone to flooding or mudslides.
Waves will top 30-40+ feet in the right-front quadrant of Iselle, which is expected to hit the northeastern part of the Big Island and subsequently rake the other islands. Surfers will do what surfers will do, but the rest of the public should stay away from the water as waves that large are dangerous on their own independent of the risk for rip currents.
Rip currents are strong, shallow currents that can drag a swimmer out away from shore. If you're ever caught in a rip current, swim parallel to shore until you're out of the current, then swim back towards land.
As with all landfalling tropical systems, tornadoes are possible, especially in areas to the north of the hurricane's center of circulation. The NWS office in Honolulu is responsible for issuing tornado watches and tornado warnings in the islands.
On Hurricane Iselle's heels is Hurricane Julio, which also poses a threat to the Hawaiian Islands. It doesn't look like Julio will make a direct hit, but some of the islands are still in the cone of uncertainty, so it's worth paying close attention to its progress over the next five days.
Forecasting responsibility for Hurricane Iselle is currently held by the Central Pacific Hurricane Center in Honolulu. The National Hurricane Center in Miami is handling Julio. Once Julio crosses 140°W, however, it will become the responsibility of the CPHC.
The next complete advisories on both Iselle and Julio come out at 11AM HST (5PM EDT).
[Images: GOES / author / Gibson Ridge / NWS / NWS / author]