Weather Forecast

Hawaii County Weather Forecast for August 30, 2021

August 30, 2021, 7:15 AM HST
Listen to this Article
5 minutes
Loading Audio...
A
A
A

no slideshow

Hilo

Today: Mostly sunny with scattered showers in the morning, then partly sunny with isolated showers in the afternoon. Highs 78 to 84 near the shore to 64 to 70 at 4000 feet. East winds up to 10 mph. Chance of rain 30 percent.

Tonight: Mostly cloudy with scattered showers. Lows 63 to 72 near the shore to around 57 at 4000 feet. Northeast winds up to 10 mph in the evening becoming light. Chance of rain 50 percent.

Tuesday: Partly sunny with scattered showers. Highs 78 to 85 near the shore to 64 to 71 at 4000 feet. East winds around 10 mph. Chance of rain 50 percent.

Kona

Today: Mostly sunny with isolated showers in the morning, then mostly cloudy with scattered showers in the afternoon. Highs 82 to 87 near the shore to around 67 near 5000 feet. West winds up to 10 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy. Isolated showers in the evening. Lows around 72 near the shore to 51 to 56 near 5000 feet. Light winds. Chance of rain 20 percent.

ARTICLE CONTINUES BELOW AD

Tuesday: Partly sunny. Isolated showers in the afternoon. Highs around 85 near the shore to around 67 near 5000 feet. Light winds. Chance of rain 20 percent.

Waimea

ARTICLE CONTINUES BELOW AD

Today: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 64 to 84. Northeast winds up to 10 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then isolated showers after midnight. Lows 64 to 70 near the shore to 57 to 63 near 3000 feet. East winds up to 10 mph. Chance of rain 50 percent.

Tuesday: Partly sunny with scattered showers. Highs 63 to 84. East winds up to 10 mph. Chance of rain 50 percent.

Kohala

ARTICLE CONTINUES BELOW AD

Today: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 64 to 84. Northeast winds up to 10 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then isolated showers after midnight. Lows 64 to 70 near the shore to 57 to 63 near 3000 feet. East winds up to 10 mph. Chance of rain 50 percent.

Tuesday: Partly sunny with scattered showers. Highs 63 to 84. East winds up to 10 mph. Chance of rain 50 percent.

South Big Island

Today: Mostly sunny in the morning, then mostly cloudy with scattered showers in the afternoon. Highs around 83 near the shore to around 65 near 5000 feet. East winds up to 15 mph. Chance of rain 30 percent.

Tonight: Mostly cloudy with isolated showers in the evening, then partly cloudy after midnight. Lows around 73 near the shore to around 53 near 5000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Tuesday: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 84 near the shore to around 66 near 5000 feet. East winds around 10 mph. Chance of rain 20 percent.

Puna

Today: Mostly sunny with scattered showers in the morning, then partly sunny with isolated showers in the afternoon. Highs 78 to 84 near the shore to 64 to 70 at 4000 feet. East winds up to 10 mph. Chance of rain 30 percent.

Tonight: Mostly cloudy with scattered showers. Lows 63 to 72 near the shore to around 57 at 4000 feet. Northeast winds up to 10 mph in the evening becoming light. Chance of rain 50 percent.

Tuesday: Partly sunny with scattered showers. Highs 78 to 85 near the shore to 64 to 71 at 4000 feet. East winds around 10 mph. Chance of rain 50 percent.

Waikoloa

Today: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 86 near the shore to 66 to 72 above 4000 feet. North winds up to 10 mph shifting to the northwest in the afternoon. Chance of rain 20 percent.

Tonight: Mostly cloudy. Lows around 73 near the shore to 51 to 56 above 4000 feet. Light winds.

Tuesday: Partly sunny. Highs 84 to 89 near the shore to 65 to 72 above 4000 feet. Light winds.

Detailed Forecast

Synopsis

A weak surface trough will move slowly over the islands from east to west, starting later today and continue through about Wednesday. The trough will weaken the trade winds and allow for localized daytime sea breezes and nighttime land breezes in some spots through about midweek. Showers will tend to favor windward and mauka areas during the nights and mornings, and interior and leeward locales during the afternoons and evenings. Relatively dry and breezy trade wind weather is expected to return for the latter portion of the new week.

Discussion

12z soundings continued to show a relatively weak and elevated subsidence inversion, about 8000 feet above Hilo and near 10000 feet over Lihue. Believe this is due to a weak 700 mb low developing near the islands. Even though precipitable water values are relatively modest…near 1.2-1.3 inches statewide, satellite and radar showing scattered showery clouds over and upwind from the islands from Kauai to Molokai. Some of these will likely fade after the sun comes up.
The tail end of a surface trough NE thru E of the islands approximately near 151W (based on satellite imagery and a partial evening ASCAT pass) will continue edging W, being reinforced by the mid-level low. This will lead to decreasing trades as the weak surface trough drags very slowly across the islands later today through about Wed. Today looks to be a hybrid pattern with light trades and a mix of some morning windward and mauka trade wind showers and a few afternoon leeward showers. Similar for Tue…although with even lighter winds, more of a trend toward afternoon interior showers. Although the mid-level low and surface trough will help to allow for taller showers, relatively meager precipitable water values should keep things from being too active.
The 00z ECMWF and it’s ensembles have backed off of the idea of bringing a slug of moisture up over the islands as the weak surface trough departs to our west. Thus Wed looks like a hybrid day as we transition back to trades pushing in from the east. The trades will increase and become locally windy by Friday, with drier air and warm temperatures aloft helping to keep shower activity rather sparse for the rest of the work week.
High level moisture streaming up from the southeast will lead to high clouds at times the next few days. Generally these will be thin, but they may thicken enough to lead to milky skies and dim sunshine for some areas starting near the Big Island on Wed and for the smaller islands Wed night and possibly into Thu morning before departing.

Aviation

Light trades and an elevated inversion are supporting a limited coverage of moderate to occasionally heavy showers focused over windward areas. This activity will diminish during mid-morning. By this afternoon, a modified sea breeze pattern will give rise to clouds and showers over favored leeward areas while windward showers decrease in coverage. Land breezes will bring clearing skies tonight.

Marine

No major changes to the marine forecast with the morning package. Light easterly flow will continue today and tomorrow with high pressure far to the north and a surface trough to the northeast. The trough is expected to move to the west heading into mid-week, allowing the pressure gradient over the region to strengthen again. This will bring moderate to locally breezy trade winds back for the second half of the week.
The current small south swell is slowly declining, with this trend expected to continue into Tuesday. A series of small south and southeast swells will continue to keep south shore surf from going flat through the end of the week. With the light winds, expect surf to continue to diminish along east facing shores with nearly flat conditions expected by tonight. During the second half of the week as trades strengthen, expect surf to gradually increase. No other significant swells are expected.

HFO Watches/Warnings/Advisories

None.

Big Island Now Weather is brought to you by Blue Hawaiian Helicopters.

Check out their Big Island Helicopter Tours today!

Data Courtesy of NOAA.gov

Comments

This comments section is a public community forum for the purpose of free expression. Although Big Island Now encourages respectful communication only, some content may be considered offensive. Please view at your own discretion. View Comments

Newsletters

Get a quick summary of what’s happening on the Big Island with our daily & weekly email of news highlights.