Trade winds will continue to strengthen slightly tonight as Tropical Storm Moke moves generally from east to west, south of the islands. This system will deliver periods of rainfall to all islands from late tonight through Monday, with the heaviest rainfall forecast along windward and southeast slopes of the Big Island. A Flood Watch goes into effect for the Big Island at midnight Saturday night. A Wind Advisory is in effect for parts of the Big Island and Maui County through 6 PM HST Sunday. Drier trade wind weather will return Tuesday.
Trade winds are continuing to strengthen across the state as Tropical Storm Moke approaches and passes south of the Big Island this weekend. Trades will continue to strengthen from east to west through Sunday. Showers will primarily impact windward and mountain locations providing occasional MVFR conditions to those areas. Windward Big Island could see periods of heavy rain and IFR conditions starting early Sunday morning from Tropical Storm Moke. VFR is expected to prevail elsewhere.
AIRMET Tango is in effect for low level turbulence downwind of terrain. AIRMET Sierra will likely be needed for windward Big Island when showers start moving into the area.
Issued at 321 PM HST Sat Aug 22 2026 Trades are strengthening in response to Tropical Storm Moke passing south of the islands and the Small Craft Advisory remains in effect through the weekend. Breezy trades then persist well into next week as high pressure remains anchored along 30N.
Surf along E and SE shores gradually builds in response to strengthening trades and short period fresh swell emanating from Tropical Storm Moke. The direction of this swell will transition to S and then SW as Moke advances west. A High Surf Advisory (HSA) may be needed for the SE shores of the Big Island tonight into Sunday, but at this time it appears surf will fall shy of the HSA threshold.
Surf along S shores remains slightly below the summer average but still slightly elevated through the weekend due to a small, long period SW swell. A series of long period S swells arrive during the middle of next week bumping surf to around the advisory threshold.
A small medium to long period NW swell originating from Hurricane Lala provides elevated surf along N and W shores this weekend.
Wind Advisory until 6 PM HST Sunday for Big Island Interior-Big Island North-Big Island South-Big Island Southeast-Kahoolawe- Kohala-Lanai Leeward-Lanai Mauka-Lanai Windward-Maui Central Valley North-Maui Central Valley South-Maui Leeward West-Molokai Leeward South-Molokai North-Molokai Southeast-Molokai West-South Haleakala-Windward Haleakala.
Flood Watch from midnight HST tonight through Monday afternoon for Big Island East-Big Island Interior-Big Island North-Big Island South-Big Island Southeast-Big Island Summits-Kohala-Kona.
Small Craft Advisory until 6 PM HST Sunday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Big Island Windward Waters-Kaiwi Channel-Kauai Channel-Kauai Leeward Waters-Kauai Northwest Waters-Kauai Windward Waters- Maalaea Bay-Maui County Leeward Waters-Maui County Windward Waters-Oahu Leeward Waters-Oahu Windward Waters-Pailolo Channel.
