A plume of moisture remains over the eastern end of the state, bringing clouds and showers to the Big Island this evening. Winds remain light, with land breezes expected in most areas of the state, with a return to trade winds Thursday. Drier trade wind weather is expected to develop Thursday night into early next week.
Satellite derived precipitable water (PW) shows 2 inches of PW over the southeastern coast of the Big Island, which matches well with the afternoon sounding from Hilo. Although rainfall rates are under an inch per hour, the ground remains very saturated, and the rain has caused some flooding of roadways. With the light winds, we anticipate land breezes kicking in this evening, which should help to move the rain offshore.
A surface trough over the central islands is moving to the west, and is helping to provide some of the instability near the islands. Combined with the high PW values, there are a few more showers statewide. However as the trough moves to the west, we can expect trade winds to slowly build in from east to west. Moisture will linger, but the focus of showers should return to more typical windward sides of the islands. Expect the trade wind pattern to persist into next week.
An upper level low is expected to remain far to the northeast of the state heading into the weekend and then lift northward. Dewpoints remain in the low 70s across the state, and when combined with the light winds, it makes it feel warm and muggy. Models suggest dewpoints will drop back into the upper 60s Thursday night, providing some relief from the muggy conditions.
Observations show the trade winds have set up across the islands tonight, with radar showing showers across the region. Ceilings and visibility will likely be reduced to MVFR to IFR conditions due to these showers. As a result, AIRMET Sierra remains for the Big Island, Maui, Lanai, and Molokai through at least 10Z. Showers should wrap up between 10-14Z for most sites, with the forecast showing drier trade wind conditions for Thursday.
For sites PMDY and NSTU, the forecast shows an increase in easterly winds between 18-21Z. Started to trend winds up as a result, but these may need to be adjusted with the next forecast update.
Issued at 519 PM HST Wed Sep 9 2026 A surface trough over the state will gradually move westward tonight. As the trough moves west, moderate to locally fresh trade winds will gradually return from east to west across the island chain through through Thursday and then persist into the weekend. The surface trough will bring some scattered showers across the area through Thursday.
The current moderate mid-period south swell continues to decline this afternoon and surf has dropped below advisory thresholds for south facing shores. This swell will continue to steadily decline over the next few days with below average surf expected by the weekend.
Surf along east facing shores will gradually decrease tonight and will remain near seasonal averages through around Saturday due to east and northeast swells generate by former tropical cyclones. Surf along north facing shores continues to receive a small bump due to Lowell. This short-period northwest swell will quickly fade, allowing surf to become tiny along north facing shores on Thursday as Lowell weakens and tracks away from the islands.
None.
