Polo threatens storm surge, high winds and heavy rain along Mexico's Pacific coast, while Nolo drifts further from the Hawaiian Islands.
Nolo is moving away from the islands but continues to bring rain and flooding risks, while Polo approaches Mexico's Pacific coast.
Officials warned the intensifying storm could bring powerful winds and flash flooding even as it passed by the islands.
Forecasters expect the storm to slow and strengthen into a major hurricane near the Big Island this weekend, worsening flood risk in already saturated areas.
Southwestern Mexico braced for heavy rain after Polo strengthened into a major hurricane, while forecasters warn a separate storm could bring catastrophic flooding to Hawaii.
Heavy rain and extreme surf are forecast as the storm approaches areas still recovering from previous weather events.
Forecasters say the storm could dump up to 25 inches of rain and generate large coastal waves even as it is expected to pass west of the islands.