textproduct: Honolulu

SYNOPSIS

High pressure far to our northwest will pass north of the islands today, turning our cool northerlies to dry trades. The high will move well northeast of the islands Sunday, causing local background winds to turn southeasterly. Humidity levels will be comfortably low through the holiday weekend. Very little, if any rainfall is expected for the next couple of days, but a small increase in mainly windward and mauka showers is expected after that. Our next cold front is expected to bring wet weather that will reach the islands around the middle of next week.

DISCUSSION

Across the chain some very isolated light showers along with some scattered to overcast skies continue this morning. As an upper level ridge axis continues to pass over the state this weekend, dry and stable moderate trades will keep any showers to a minimum. Any that do that do develop will remain isolated and confined to windward and mauka locations.

Winds will become veer southeast Sunday and remain that way through Tuesday. This will bring enhanced moisture and a slight increase in showers, along with warmer temperatures. Late Tuesday, winds will become weak and mainly southerly as a cold front moves in from the northwest. The front should reach the western half of the state Tuesday night, then slow down, finally reaching the Big Island late Wednesday night or Thursday. There is significant model spread on whether or not it actually makes it past Big Island and heads away to the east, or stalls and moves back over the state from east to west. That makes this a low confidence forecast from mid week into next weekend.

AVIATION

Moderate trades expected to continue through Sunday before veering southeasterly. A few isolated showers can be expected over windward and mauka locations with minimal impacts to vsbys maintaining VFR conds.

AIRMET Tango remains in effect for low level turb downwind of terrain.

MARINE

A high pressure system north of the state will track east over the next couple of days maintaining stable moderate to locally strong trade winds. The northeasterly winds will becoming more easterly later today through Sunday. By late Sunday into early next week, winds will weaken and veer southerly, becoming light to gentle by Tuesday as a front approaches from the northwest. This next cold front could start moving through the coastal waters as early as late Tuesday afternoon.

A fading extra large northwest swell continues to produce high seas above advisory levels. A Small Craft Advisory (SCA) has been extended for all Hawaiian waters through 6 PM HST this evening for combined seas above 10 feet, and winds to 25 kt. Seas from the swell are expected to drop later today thus can expect most zones to drop out of the SCA, expect for typically windy areas around Maui County and the Big Island.

The extra large, medium to long period northwest (320-340 degrees) swell which peaked Friday, continues to fade this morning. Near shore buoys show lots of energy in the 12-16 band range which is why the High Surf Warning was downgraded to a low end High Surf Advisory (HSA) for north facing shores of Niihau, Kauai, Oahu, Molokai, and Maui. Surf has declined below advisory levels for west facing shores. This swell will continue to transition to a more northerly direction (350-010 degrees) as it fades. Surf will drop below advisory levels later this morning and afternoon. A moderate northwest swell (320 degree) is expected to arrives Sunday into Sunday night. This swell looks to briefly bring surf heights well above advisory levels for north and west facing shores. Tuesday through through mid week next week shows a series of overlapping moderate, west northwest swells that will keep surf along north and west facing shores elevated.

Rough, choppy surf along east facing shores will hold for the next couple of days. Additionally, some east facing shores sensitive to northerly swells may experience a slight uptick in surf heights this weekend as the fading northwesterly swell becomes more northerly. No noteworthy swells are expected for the next few days for south facing shores.

HFO WATCHES/WARNINGS/ADVISORIES

High Surf Advisory until 6 PM HST this evening for Niihau-Oahu North Shore-Maui Windward West-Kauai North-Molokai Windward- Molokai North-Molokai West-Maui Central Valley North-Windward Haleakala.

Small Craft Advisory until 6 PM HST this evening for all Hawaiian waters-