Weather Forecast

Hawaii County Weather Forecast for August 22, 2021

August 22, 2021, 7:15 AM HST
Listen to this Article
5 minutes
Loading Audio...
A
A
A

no slideshow

Photo Credit: James Grenz

Hilo

Today: Mostly cloudy. Scattered showers in the morning, then scattered showers and slight chance of thunderstorms in the afternoon. Locally heavy rainfall possible. Highs 83 to 89 near the shore to around 74 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers and slight chance of thunderstorms. Locally heavy rainfall possible. Lows 68 to 75 near the shore to around 57 at 4000 feet. South winds up to 10 mph. Chance of rain 50 percent.

Monday: Cloudy with showers likely and slight chance of thunderstorms. Locally heavy rainfall possible. Highs 83 to 89 near the shore to around 74 at 4000 feet. East winds up to 10 mph. Chance of rain 70 percent.

Kona

Today: Sunny in the morning, then mostly cloudy with scattered showers and slight chance of thunderstorms in the afternoon. Locally heavy rainfall possible in the afternoon. Highs 82 to 87 near the shore to around 72 near 5000 feet. Northwest winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with slight chance of thunderstorms and isolated showers. Locally heavy rainfall possible. Lows 70 to 75 near the shore to around 56 near 5000 feet. Southeast winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

ARTICLE CONTINUES BELOW AD

Monday: Cloudy with showers likely and slight chance of thunderstorms. Locally heavy rainfall possible. Highs 82 to 87 near the shore to around 72 near 5000 feet. South winds up to 10 mph shifting to the west in the afternoon. Chance of rain 70 percent.

Waimea

ARTICLE CONTINUES BELOW AD

Today: Scattered showers in the morning, then showers and slight chance of thunderstorms in the afternoon. Locally heavy rainfall possible. Highs 72 to 85. North winds up to 10 mph. Chance of rain near 100 percent.

Tonight: Mostly cloudy with scattered showers and slight chance of thunderstorms. Locally heavy rainfall possible. Lows around 70 near the shore to 58 to 64 near 3000 feet. West winds up to 10 mph in the evening becoming light. Chance of rain 50 percent.

Monday: Cloudy with showers likely and slight chance of thunderstorms. Locally heavy rainfall possible. Highs 72 to 85. East winds up to 15 mph. Chance of rain 70 percent.

Kohala

ARTICLE CONTINUES BELOW AD

Today: Scattered showers in the morning, then showers and slight chance of thunderstorms in the afternoon. Locally heavy rainfall possible. Highs 72 to 85. North winds up to 10 mph. Chance of rain near 100 percent.

Tonight: Mostly cloudy with scattered showers and slight chance of thunderstorms. Locally heavy rainfall possible. Lows around 70 near the shore to 58 to 64 near 3000 feet. West winds up to 10 mph in the evening becoming light. Chance of rain 50 percent.

Monday: Cloudy with showers likely and slight chance of thunderstorms. Locally heavy rainfall possible. Highs 72 to 85. East winds up to 15 mph. Chance of rain 70 percent.

South Big Island

Today: Breezy. Sunny in the morning, then partly sunny with scattered showers and slight chance of thunderstorms in the afternoon. Locally heavy rainfall possible in the afternoon. Highs around 87 near the shore to around 77 near 5000 feet. West winds up to 20 mph. Chance of rain 50 percent.

Tonight: Partly cloudy. Lows around 71 near the shore to around 55 near 5000 feet. North winds up to 15 mph shifting to the southeast after midnight.

Monday: Breezy. Cloudy with scattered showers and slight chance of thunderstorms. Locally heavy rainfall possible. Highs around 87 near the shore to around 77 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Puna

Today: Mostly cloudy. Scattered showers in the morning, then scattered showers and slight chance of thunderstorms in the afternoon. Locally heavy rainfall possible. Highs 83 to 89 near the shore to around 74 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers and slight chance of thunderstorms. Locally heavy rainfall possible. Lows 68 to 75 near the shore to around 57 at 4000 feet. South winds up to 10 mph. Chance of rain 50 percent.

Monday: Cloudy with showers likely and slight chance of thunderstorms. Locally heavy rainfall possible. Highs 83 to 89 near the shore to around 74 at 4000 feet. East winds up to 10 mph. Chance of rain 70 percent.

Waikoloa

Today: Sunny with scattered showers in the morning, then mostly cloudy with scattered showers and slight chance of thunderstorms in the afternoon. Locally heavy rainfall possible. Highs 83 to 88 near the shore to 69 to 76 above 4000 feet. North winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers and slight chance of thunderstorms. Locally heavy rainfall possible. Lows around 74 near the shore to 53 to 61 above 4000 feet. Southeast winds up to 10 mph in the evening becoming light. Chance of rain 50 percent.

Monday: Mostly cloudy with scattered showers and slight chance of thunderstorms. Locally heavy rainfall possible. Highs 83 to 88 near the shore to 69 to 76 above 4000 feet. Northwest winds up to 10 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

The remnants of former Tropical Cyclone Linda are expected to move through the islands between today and Monday night, bringing with it the potential for heavy rains that may result in flash flooding, and accompanied by locally breezy winds. The weather is expected to improve with a return to a more trade wind pattern starting Tuesday, and lasting through the second half of the week.

Discussion

A flash flood watch remains in effect for all Hawaiian Islands through 6am HST Tuesday morning. The overall expectations remain largely unchanged, that is generally 2-4 inches, with locally higher amounts, to 6 inches is forecast for the windward areas. Locally up to 10 inches is possible should thunderstorms develop. The weather will be deteriorating east of Kauai today, particularly the Big Island and Maui later this morning, then the rest of Maui County this afternoon, followed by Oahu tonight. It could be an all day event for Oahu on Monday, while the weather spreads to Kauai Monday afternoon. Most of the unsettled weather should be west of Kauai by sunrise Tuesday, with a return to a more typical trade wind weather for the rest of the week.
The path of Linda’s remnants is critical as far as winds are concern. Should Linda cuts across leeward Maui County, the islands will be on the windy side of the system. Should Linda stays slightly north of the smaller islands, it will not be so windy. The current wind grids have breezy east to northeast winds traversing islands and the windward waters. So, a Wind Advisory is not out of the question at this time.
The current forecast has Linda’s circulation reaching Maui shortly after midnight tonight, and passing just south of Oahu Monday afternoon. From that point on, the circulation of Linda becomes a trough as it passes Kauai Monday night.
As of 200 am HST, satellite imagery shows the circulation of former TC Linda about 225 miles ENE of Hilo. It is moving west at 10 mph. The remnants of Linda has been voided of any deep convection since Saturday afternoon. So far, the trade showers have been scattered, with windward Big Island the wettest, and Oahu and Kauai, the driest, although radar is picking up a few trade showers just upwind of Oahu.

Aviation

The outer circulation of a gale low, which is former Tropical Cyclone Linda, is approaching the islands from the east. As this system continues to move toward the state, expect breezy to locally windy northeasterly winds to spread from east to west across the area. In addition, the coverage of low clouds and showers will likely increase from east to west across the state through tonight. This will result in MVFR conditions over the north through east sections of the islands, especially the Big Island, Maui and Molokai. In addition, the easternmost terminals, such as PHTO and PHOG, will likely continue to have periods of MVFR conditions. These deteriorating conditions will eventually spread to Oahu and Kauai later today and tonight.
AIRMET Tango remains in effect for moderate low level turbulence over and downwind of the higher terrain of all islands. This AIRMET will likely be required through this evening as the circulation of the gale low moves closer to the state.
AIRMET Sierra for mountain obscuration remains in effect for windward sections of the Big Island, Maui and Molokai. This AIRMET may need to be added for Oahu, and possibly Kauai, later today or tonight.

Marine

As of 0300 HST, a gale low from what was once Tropical Cyclone Linda is approximately 200 miles northeast of Hilo. This low is in our northeastern offshore waters and will steadily move due west into the nearshore waters tonight. Winds gusting to gale force mainly along the northern periphery of this low has initiated an offshore Gale Warning (GLW). This GLW is in effect for primarily the northeastern offshore waters through early Monday morning.
The northeast trade winds running ahead of Linda will continue at moderate to locally strong with the potential of further strengthening as described in the discussion above. Last night’s ASCAT pass confirmed that winds are at Small Craft Advisory in the Alenuihaha Channel. Thus, an SCA is in effect for the windy areas surrounding Maui County as well as for responding seas reaching 10 foot thresholds over more eastern windward waters today. The gale low will pass within the vicinity of Maui and Oahu’s nearshore waters during the day Monday with the strongest winds likely on the north side of the low. SCAs are in effect from east- to-west through early Tuesday morning to account for both strong to near gale force winds and high seas in association with the passing circulation. Thunderstorms are also possible today through Monday night with any winds in the vicinity of these storms quickly becoming dangerous. The passage of the low or open wave trough west of Kauai will have areawide moderate to locally fresh trades returning Tuesday.
East swell from a gale low will be arriving over the eastern end of the state today. Surf and buoy observations indicate a steady rise in the lower period wind wave swell energy bands. A High Surf Advisory (HSA) is in effect for all east facing shores through Monday morning as this swell propagates west and impacts more western islands. Resultant east facing surf heights will likely peak later today over the eastern end of the state and Monday over the western end of state. A series of small, low to moderate period south swells will maintain small surf along south facing shores next week. No anticipated north or west swell equates to near flat north and west surf the next several days.

HFO Watches/Warnings/Advisories

Flash Flood Watch through late Monday night for all Hawaii islands,
High Surf Advisory until 6 AM HST Monday for Maui Windward West, Molokai Windward, Molokai Southeast, Windward Haleakala, Kipahulu, Big Island Southeast, Big Island East, Big Island North.
High Surf Advisory until 6 AM HST Monday for Olomana, Kauai East, Kauai South, East Honolulu, Koolau Windward.
Small Craft Advisory until 6 AM HST Monday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel.
Small Craft Advisory until 6 AM HST Monday for Big Island Windward Waters.
Small Craft Advisory until 6 PM HST Monday for Kaiwi Channel, Maui County Windward Waters.
Small Craft Advisory from 6 AM Monday to 6 AM HST Tuesday for Kauai Windward Waters, Kauai Channel.
Small Craft Advisory from 6 PM Monday to 6 AM HST Tuesday for Kauai Northwest Waters.
Small Craft Advisory until 6 AM HST Tuesday for Oahu Windward Waters.

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.