HONOLULU (KHON2) – On Saturday, we should see a brief return of some moderate east to east-southeast trades across the state.
Fair weather conditions are expected for most of the state, with the exception of southeast and windward Big Island, where we should see some moisture from a weak frontal boundary move in late in the morning through the afternoon.
On Sunday, another frontal boundary will approach the state, which will cause the winds to veer to the southeast and south.
This will allow for some moisture to move in from the south mainly over Kauai.
There are still quite a bit of uncertainty on how showery it could be on Sunday with the GFS mainly showing some scattered showers, while the ECMWF shows numerous showers throughout the day.
With ensemble members of the GFS ECMWF and the Canadian showing pretty low probability for moderate showers, I would lean towards the GFS solution for Sunday.
As the frontal boundary continues to approach the state Sunday night into Monday, instability will increase and will allow for heavier showers around the western end of the state.
This band of moisture is expected to eventually shift eastward sometime during the day on Monday, where we could see some heavy showers and even some isolated thunderstorms.
Although details are still uncertain, some flooding impacts will be possible on Monday mainly over the smaller islands.
The front is expected to quickly weaken Monday night into Tuesday as a high builds north of the state. Trade winds are expected to return on Tuesday.
High Surf Advisory until 6 PM HST Saturday for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Maui Windward West, Kona, Kohala, Kauai North, Molokai Windward, Molokai North, Molokai West, Windward Haleakala.
Small Craft Advisory until 6 PM HST Saturday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters.
Small Craft Advisory from 6 AM to 6 PM HST Saturday for Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.