Marine Weather and Tide Forecast for Heeia, HI

DISCUSSION
Visible satellite and radar imagery show an area of low clouds and isolated to scattered showers moving across the eastern and central portions of the state this morning. Elsewhere, skies are mostly clear. Models continue to show that light to locally moderate easterly trade winds will fill in across the state today and persist into tomorrow morning before gradually strengthening into next week. Winds will likely remain light enough across the state to allow for the development of localized sea breezes later this morning into the afternoon and land breezes overnight. As the trades begin to strengthen tomorrow, sea breeze activity will be hindered some, but will likely still occur across some of the more sheltered leeward areas. This hybrid pattern of redeveloping trades and sea breezes will support isolated to scattered showers across windward and mauka areas this morning and tonight with additional isolated showers over island interiors each afternoon.

Another front will approach from the northwest today through Sunday. Models continue to show its tail end dissipating before it reaches the state, but batches of remnant moisture will move in on the strengthening trades early next week as high pressure strengthens to the north. These breezy to strong trades will persist through the week and into next weekend, focusing clouds and showers mainly over windward and mauka areas. An upper level shortwave trough will move down the island chain early next week, pinch off from the main trough to form a cutoff low south of the state before slowly progressing westward through the week. The proximity if this feature may serve to help enhance windward showers, particularly over the southern end of the state, but no significant impacts are expected at this time.

AVIATION
Expect weak easterly trade winds across the islands today with a weak trough to the northeast and an incoming front to the northwest. Light winds across the region will allow local sea breezes to develop across sheltered locations in the afternoon with land breezes developing overnight. A strong inversion aloft between 07 kft and 09 kft will keep moisture trapped in the lower levels. Any afternoon shower activity will be light to moderate in intensity and in limited in scope.

Will see a return of moderate to breezy trade wind conditions by early next week.

MARINE
Weakening trade winds today will allow for some land and sea breezes over the near shore waters today and tonight. High pressure building north of the state tonight and Sunday will lead to strengthening trades on Sunday with moderate trades expected by Sunday afternoon. Winds are expected to continue the strengthening trend Monday night through the end of the new week with fresh to strong trade winds. Small Craft Advisory (SCA)
level winds are expected in the typical windier waters near Maui County and the Big Island Monday, with additional waters impacted Tuesday based on the wind criteria. From Wednesday onwards, additional areas may be placed under a SCA due to increasing seas.

A northwest (330 degree) swell is moving through the island waters today, and is maintaining High Surf Advisory (HSA) for exposed north and west facing shores. This current swell is expected to decline tonight and Sunday. Model guidance would suggest that advisory level surf will linger into at least the first part of tonight, and as such, will continue to monitor the near shore buoy reports today to determine if the HSA needs to be extended into tonight.
Another northwest swell is expected to arrive late Sunday night, rising to advisory levels by Monday afternoon, and then declining Tuesday night. Another northwest swell early Thursday will boost surf, and at this time models would suggest surf could approach advisory levels for a short time. A small south swell will continue through Sunday, before diminishing early next week.

FIRE WEATHER
Critical fire weather conditions are not anticipated over the next several days. For this weekend, winds will be too light and relative humidity too high to be of any concern. For next week, trades will strengthen to become breezy to strong, but relative humidities will remain sufficiently high.

HFO WATCHES/WARNINGS/ADVISORIES
High Surf Advisory until 6 PM HST this evening for Niihau-Kauai Leeward-Waianae Coast-Oahu North Shore-Maui Windward West-Kauai North-Molokai Windward-Molokai North-Molokai West-Windward Haleakala.