HONOLULU, Hawaii (HawaiiNewsNow) - The strongest cold front so far this year to reach the islands is expected to bring the risk of heavy rainfall to Oahu, Maui County and the Big Island, which are under a flash flood watch until 6 p.m. Tuesday. There’s also a wind advisory in effect until 6 p.m. Monday for the smaller islands for sustained winds of 20 to 30 miles per hour with gusts over 45 miles per hour.
The front is forecast to move down the island chain before stalling around Maui and the Big Island between Monday and Tuesday. At the same time, a developing upper level disturbance will enhance moisture from the front, which could result in flash flooding especially around windward areas of Maui County and the Big Island Monday into Monday night. Some areas could potentially get more than ten inches of rainfall over the next few days.
The front should dissipate Tuesday but moisture associated with it will linger across the state through Wednesday, while the winds taper off and are replaced by breezy trades. The weather conditions will likely remain a bit on the wet side through much of the week.
At the beach, there’s a new northwest swell that will build to peak heights near 30 to 40 feet for north-facing shores of Niihau, Kauai, Oahu and Molokai, with slightly lower heights for north shores of Maui. West shores could see surf heights peaking in the 25 to 30 foot range. A high surf warning remains posted for those shorelines, along with a high surf advisory for north and west shores of the Big Island.
For mariners, a gale warning is now in effect for waters from the Alenuihaha Channel westward for strong post-frontal north to northeast winds, while a small craft advisory remains posted for waters around the Big Island.