Trade winds will continue to strengthen today 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 remains in effect for the Big Island. A Wind Advisory has been issued for parts of the Big Island and Maui County. Drier trade wind weather will return Tuesday.
Trade winds will fill back in over the islands as Tropical Storm Moke approaches and passes south of the Big Island this weekend, increasing the pressure gradient across the state. Trades will gradually strengthening from east to west, becoming strong by this afternoon and continuing to build on Sunday.
AIRMET Tango is in effect starting 21Z for low level turbulence downwind of island terrain.
While occasional pockets of MVFR conditions will be possible within passing showers along windward and mauka locations today, VFR conditions are expected to prevail. Tonight into Sunday, increasing moisture over the eastern end of the state as Tropical Storm Moke passes by to our south will result in increasing chances for heavy rainfall, along with low visibilities and ceilings, across the Big Island. This will bring more widespread MVFR and IFR conditions.
Trades are strengthening in response to Tropical Storm Moke approaching from the south and the Small Craft Advisory for winds and seas remains in effect through the weekend. Breezy trades then persist well into next week.
Surf along E and SE shores gradually builds this weekend 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 potentially bumping surf to 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 late 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 from 6 PM this evening to 6 PM HST Sunday for Kauai Channel-Kauai Leeward Waters-Kauai Northwest Waters- Kauai Windward Waters.
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-Maalaea Bay-Maui County Leeward Waters-Maui County Windward Waters-Oahu Leeward Waters- Oahu Windward Waters-Pailolo Channel.
