Trade winds will persist across the main Hawaiian Islands through the forecast period, becoming stronger Thursday through early next week due to building high pressure to our north. A weak frontal cloud band expected to pass across the islands tonight and will bring an increase in clouds and showers. A shortwave over the state will bring a progressively wet trade wind weather pattern this weekend and Monday.


A ridge of high pressure far north of the state is driving moderate to fresh trade winds across Hawaii late this afternoon. Visible satellite shows a band of clouds associated with a weak cold front moving onto the island chain at this time. We have already seen an increase in clouds and showers from Kauai to Maui earlier this afternoon. The front will continue to impact these areas tonight as well as extend to the Big Island tonight. The front is fairly shallow and moving relatively quickly, so rainfall intensity and accumulation amounts are expected to be on the light to moderate side. The trade winds will focus showers across windward and mauka areas, but will occasionally pass to leeward sides of the islands at times tonight. The front will move southwestward tonight and should be clear of the island chain Thursday morning. Anticipating more sunshine across the area by tomorrow afternoon. The high pressure system far to the northwest will build east southeastward over the next several days. As this occurs, we expect stronger trade winds to dominate across the state from Thursday night through early next week. Upper level ridging will keep a cap on showers Thursday night through Friday afternoon, with only light rainfall amounts expected within trade showers. An upper level shortwave is expected to pass just northeast of the island chain Friday night, followed by a second wave Sunday and Monday. Models show these disturbances enhancing the low level showers carrying in with the trade winds, which translates to a progressively wet trade wind weather pattern from Friday night into early next week. The stronger than average trade winds will ensure many of the leeward sides of the islands will get some rainfall at times. The midlevel ridge begins to build back in around Tuesday of next week while the moisture slides west of the state, resulting in a drier weather pattern. Meanwhile, the high pressure to the north will weaken, which will also weaken the trade winds back to moderate levels.


A shallow band of moisture moving along a rather stable trade wind flow will move over the islands through the first part of tonight, bringing widespread MVFR ceilings to windward slopes. AIRMET Sierra for mountain obscuration is in effect from Kauai to Maui and will be extended to cover windward Big Island by nightfall. Mountain obscuration is expected to diminish over the smaller islands by around midnight but may linger through the night on the Big Island. VFR conditions will prevail over leeward areas tonight, and as a drier airmass moves overhead on Thursday, VFR conditions should dominate statewide. The stable trade wind flow will increase as the shallow band of moisture clears most islands late tonight. AIRMET Tango for low level turbulence to the lee of all islands will likely be issued tonight and persist beyond Thursday.


Moderate trade winds with locally breezy conditions will remain through tonight before the trade winds strengthen on Thursday. A Small Craft Advisory (SCA) is in effect for the typical windy zones around Maui County and the Big Island through Thursday, which will likely be expanded to cover additional zones or all coastal waters Thursday night. Winds will remain fresh to strong across the waters into early next week. The current northwest swell will decline tonight. A series of small to moderate north and northwest swells will fill in this weekend and again towards the middle of next week, but surf is expected to remain below advisory levels. For the south facing shores a small long period swell will bump surf up slightly today into Friday. A long period east swell is possible this weekend from the distant Hurricane Seymour in the Eastern Pacific.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Thursday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.



Back to Top