Tuesday evening update: A hurricane warning is now in effect for the Big Island, replacing the hurricane watch issued earlier. Madeline, the first of the two storms, is expected to bring hurricane conditions to the Big Island as soon as late Wednesday and may continue into early Thursday.

Madeline’s peak winds have decreased some to 110 mph, so it is now a Category 2 hurricane instead of 3. But it is expected to maintain hurricane strength as it comes very close to or directly strikes the Big Island.

For detailed information on specific impacts expected on the Big Island and elsewhere, see the local hurricane statement from the National Weather Service forecast office in Honolulu.

The International Space Station captured timelapse footage of Hurricanes Lester and Madeline in the Pacific Ocean and of Hurricane Gaston in the Atlantic. (NASA)

Original post from Tuesday afternoon

Hawaii is in the crosshairs of two significant hurricanes, Madeline and Lester. But whether the storms directly strike or just skirt parts of the state is unknown.

The hurricanes are both rated Category 3 on the 1-to-5 Saffir-Simpson scale. This makes them major hurricanes, defined as those ranked Category 3 or higher.

If either storm strikes Hawaii’s Big Island as a hurricane, it would mark the first such occurrence ever recorded since 1949.

Hurricane Madeline

Madeline poses the most immediate threat. The Central Pacific Hurricane Center has issued a hurricane warning for the Big Island, meaning hurricane conditions are possible within 48 hours.

The storm is centered 445 miles east of Hilo and moving westward at 10 mph. Its closest approach to the Big Island should occur Wednesday night.

Some models suggest Madeline could make history with a direct strike on the Big Island, while others keep it well south, as the Central Pacific Hurricane Center explains: “[T]here are a few models that take Madeline over southern portions of the Big Island, notably GFDL and ECMWF. However other models, notably GFS, take Madeline noticeably farther south of the Big Island.”

Madeline’s maximum sustained winds are currently 120 mph, but they are forecast to slowly weaken as the storm moves over cooler waters and increasing wind shear. When it nears the Big Island, it is still predicted to be at hurricane intensity, with maximum sustained winds of 85-90 mph.

The Hurricane Center is advising the Big Island to prepare for tropical-storm-force winds and the possibility of hurricane conditions. Rainfall on the Big Island could total 5 to 10 inches, with locally higher amounts in the high terrain on the island’s windward (eastern) side.

Tropical storm conditions could also extend to Maui.

Hurricane Lester

On the heels of Madeline, Hurricane Lester follows packing winds of 120 mph. It is some 1,355 miles east of Hilo moving west at 14 mph.

On Monday, the storm peaked in intensity, briefly becoming a Category 4 hurricane with winds to 140 mph. At the time, it featured a stunning and menacing presentation on satellite imagery, with small swirls known as mesovortices embedded within its eye.

Lester is forecast to continue weakening gradually over the next several days. Its closest approach to Hawaii would likely occur between Friday and Sunday. By then, maximum sustained winds are forecast to be between 70 and 85 mph, which would classify it as a strong tropical storm or weak hurricane.

How close it comes to Hawaii is difficult to determine as track forecast errors are large this far out.

Most models suggest Lester may pass just north of the island chain, in part, due to interactions with Madeline. But it is certainly possible that the Big Island and other parts of Hawaii contend with high surf, wind, and rain for the second time in just five days.