Deluge begins in Hawaii as Hurricane Nolo continues to strengthen

Hawaii braces for dangerous flooding as Hurricane Nolo nears

Activelifezero.com – Hurricane Nolo is bringing increasingly heavy rain to southern Hawaii, putting the Big Island at the center of another potentially hazardous tropical weather event. The storm marks Hawaii’s third serious hurricane threat in roughly six weeks, following damaging impacts from Hurricanes Lala and Lowell earlier in the season.

Flooding and mudslides are the primary concerns as Nolo approaches, especially where earlier storms have left soils saturated and communities are still recovering. The hurricane strengthened quickly into a Category 2 system on Friday and held that intensity into Saturday morning. It could be a strong Category 2 hurricane, or potentially a Category 3 major hurricane, when it passes closest to the Big Island on Saturday local time.

Big Island faces the heaviest rainfall

Nolo is expected to track south of the Big Island, but its outer rain bands are already moving across the island. Those bands are forecast to expand toward Maui, Lanai and Molokai during Saturday.

Eastern and southern areas of the Big Island could receive 8 to 12 inches of rain through Sunday. The steepest slopes may see as much as 16 inches. Western portions of the island could receive up to 6 inches, while eastern Maui may get 4 to 6 inches, with isolated totals approaching 8 inches. Elsewhere across the main Hawaiian Islands, projected rainfall generally ranges from 1 to 3 inches.

Mountain terrain can sharply increase rainfall during tropical storms. Moist air is forced upward along steep slopes, where it cools and releases additional rain. That effect was especially destructive during Hurricane Lala in mid-August, when some Big Island mountain areas received more than 40 inches of rain and catastrophic flash flooding followed.

Rainfall from Nolo is forecast to be lower than Lala’s extreme totals, but the risk remains serious. Floodwater can rise quickly in valleys, low-lying communities and areas near streams, while saturated hillsides may become unstable. Residents in flood-prone areas may have limited time to respond once intense rain begins.

Strong gusts and hazardous surf add to the threat

The hurricane’s strongest sustained winds are expected to remain offshore because Nolo is passing well south of the Big Island. Even so, elevated terrain could experience tropical-storm-force winds exceeding 40 mph. Gusts above 75 mph, which reach hurricane force, remain possible in exposed higher elevations.

Dangerous ocean conditions are also developing. Large, rough seas are expected to peak Friday and Saturday, with hazardous surf and marine conditions likely to continue through the weekend and into next week. Conditions may remain rough even after Nolo begins moving westward away from the islands Sunday night into Monday.

Nolo’s rapid strengthening is notable. Meteorologists define rapid intensification as an increase of at least 35 mph in a storm’s maximum sustained winds within 24 hours or less. Such episodes are occurring more often as fossil-fuel pollution warms the climate, creating conditions that can support more intense tropical systems.

Emergency preparations expand statewide

Gov. Josh Green declared a state of emergency ahead of Nolo, the third weather-related emergency declaration issued in Hawaii this month. President Donald Trump approved Hawaii’s request for a pre-landfall Presidential Emergency Declaration, Green said Friday.

Public schools, state and county offices, and the University of Hawaii were closed Thursday and Friday on the Big Island. Maui closures were also planned for Friday. About 400 National Guard personnel have been positioned statewide, including 121 assigned to the Big Island.

Hawaii County has opened shelters, while the state secured 100 hotel rooms for Big Island residents seeking to evacuate. Hundreds of people across the state were already staying in hotels after displacement from earlier natural disasters, including Hurricanes Lala and Lowell.

If your home flooded before, or is at risk, consider moving to safer shelter before the full force of the storm hits. Because the ground remains saturated, flooding may happen rapidly.

On Maui, local authorities have prepared backup generators and storm-response equipment while increasing police and fire staffing. Bus operations are scheduled to be suspended at varying times through the weekend.

An unusually active Pacific season

This year’s super El Niño has created an environment favorable for powerful Pacific tropical systems. Exceptionally warm ocean water provides storms with energy, while reduced wind shear allows their circulation to organize and strengthen more easily.

Hurricane Lala passed near the Big Island as a Category 1 storm in mid-August and caused catastrophic flooding. In early September, Category 2 Hurricane Lowell brought damaging conditions to Kauai and Niihau. Nolo now arrives while many residents and emergency agencies remain engaged in recovery and preparation efforts.

For residents, the most immediate concern is rain rather than the hurricane’s center. People in areas that previously flooded, live beneath unstable slopes, or travel through low-lying routes face the greatest danger as bands of intense rainfall move across the islands. Avoiding flooded roads, monitoring local emergency notices and seeking shelter early when advised can be critical as conditions deteriorate.