Category 2 Hurricane Nolo continues to creep north as outer rain bands begin to affect Big Island

The eye of Category 2 Hurricane Nolo is slowly moving northward as outer rain bands from the storm have started to affect the Big Island.

Nolo was located about 145 miles south of South Point as of the 5 p.m. advisory update Friday, exhibiting maximum sustained winds of 105 mph, with higher gusts, and moving at just 3 mph. That general motion, with a decrease in forward speed, is expected to continue through the night before the storm takes a sharp westward turn and increases in speed Saturday and Sunday.

The center of Nolo will then remain well south of the main Hawaiian Islands.

Hurricane force winds extended outward up to 45 miles from the storm’s center as of Friday afternoon, with tropical storm force winds extending up to 140 miles.

Nolo is forecast to strengthen into a major hurricane this weekend and could further intensify early next week.

A hurricane watch, tropical storm warning and flood watch remain in effect for the entire Big Island. A high surf advisory for east- and south-facing shores of the island also remains in effect.

Hazards expected to impact land

Wind:

• Tropical storm conditions are expected to begin tonight over the Big Island, with hurricane conditions possible by early Saturday, particularly in areas of steep terrain.
• Tornadoes and waterspouts also remain possible, mainly over and near the Big Island along and to the right of Nolo’s track.

Rainfall:

• For the eastern and southern portions of the Big Island, Nolo is now forecast to produce bands of intense rainfall and thunderstorms, with total rainfall amounts of 8 to 12 inches and maximum amounts of 16 inches in some locations.
• This rainfall could produce significant, life-threatening flooding and mudslides, especially in areas of steep terrain.
• For western portions of the island, rainfall totals of 1 to 3 inches, with maximum amounts of 6 inches, are expected.

Storm surge:

• The combination of dangerous storm surge and tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline.
• Water could reach 1 to 3 feet above ground in some areas if peak surge occurs at high tide.
• Deepest water will happen along the immediate coast and be accompanied by large and dangerous waves.
• Surge-related flooding depends on relative timing of the surge and tidal cycle, and can vary greatly over short distances.

Surf:

• Swells generated by Nolo are expected to reach exposed east- and south-facing shores of the Big Island on Friday, spreading westward and building through the weekend.
• These swells are likely to cause life-threatening surf and rip current conditions.

Additional forecast information

The satellite appearance of Nolo changed little between advisories Friday afternoon; however, radar data from South Point indicates the hurricane’s eye contracted to a diameter of about 35 nautical miles. This suggests some strengthening happened, but Doppler radar velocities changed little Friday afternoon as well.

Based on a blend of earlier aircraft data, satellite intensity estimates and radar velocities, it remains a Category 2 hurricane.

Nolo also is being affected by southeasterly shear, which could be helping draw dry air into its circulation.

Guidance is in excellent agreement that Nolo should stall and then turn westward during the next 12 hours or so as a mid- to upper-level ridge builds westward north of the Hawaiian Islands. Track guidance shifted southward from earlier Friday afternoon, with the forecast track near the northern edge of the guidance envelope during the next 5 days.

Nolo is forecast to turn northward again after that, between the ridge and a mid- to upper-level trough now northwest of the state.

There is some divergence in the track guidance during the next 10 days because of how the tropical cyclone and trough interact. For now, this portion of the forecast track is similar to the previous track.

Because of shear and apparent dry air entrainment, the new intensity forecast for Nolo shows a slower development rate during the next 12 to 24 hours. While there remains uncertainty, forecasters continue to expect the hurricane to become a major hurricane within the next 3 days.

Nolo is then expected to begin weakening because of forecast strong southwesterly wind shear east of the trough northwest of the islands.

Additional resources

• Disaster preparedness information: American Red Cross.
• Appropriate preparations: Ready.gov.

For storm information specific to your area, including possible inland watches and warnings, monitor products issued by the National Weather Service Honolulu forecast office.

Also be sure to check out “What Big Island residents need to know about Hurricane Nolo” at Big Island Now for information about shelters, closures and other storm-related items that will help keep you safe.