Photo Credit: James Grenz

Hilo

Today: Mostly cloudy with scattered showers. Highs 77 to 87 near the shore to around 69 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 65 to 72 near the shore to around 57 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 70 percent.

Monday: Cloudy with scattered showers. Highs 76 to 87 near the shore to around 69 at 4000 feet. Northeast winds up to 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 83 to 89 near the shore to around 69 near 5000 feet. Light winds. Chance of rain 40 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Isolated showers. Lows around 75 near the shore to 51 to 56 near 5000 feet. Light winds. Chance of rain 20 percent.

Monday: Mostly sunny in the morning then becoming mostly cloudy. Isolated showers. Highs 83 to 89 near the shore to around 70 near 5000 feet. North winds up to 10 mph shifting to the west in the afternoon. Chance of rain 20 percent.

Waimea

Today: Breezy. Partly sunny with scattered showers. Highs 74 to 81 near the shore to 68 to 80 near 3000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 64 to 72 near the shore to around 60 near 3000 feet. East winds up to 15 mph increasing to 10 to 15 mph after midnight. Chance of rain 50 percent.

Monday: Mostly cloudy with scattered showers. Highs 66 to 85. East winds 10 to 15 mph. Chance of rain 50 percent.

Kohala

Today: Breezy. Partly sunny with scattered showers. Highs 74 to 81 near the shore to 68 to 80 near 3000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 64 to 72 near the shore to around 60 near 3000 feet. East winds up to 15 mph increasing to 10 to 15 mph after midnight. Chance of rain 50 percent.

Monday: Mostly cloudy with scattered showers. Highs 66 to 85. East winds 10 to 15 mph. Chance of rain 50 percent.

South Big Island

Today: Breezy. Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 86 near the shore to around 68 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Breezy. Lows around 74 near the shore to around 52 near 5000 feet. Northeast winds up to 20 mph.

Monday: Mostly sunny in the morning then becoming partly sunny. Highs around 86 near the shore to around 67 near 5000 feet. East winds 10 to 15 mph.

Puna

Today: Mostly cloudy with scattered showers. Highs 77 to 87 near the shore to around 69 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 65 to 72 near the shore to around 57 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 70 percent.

Monday: Cloudy with scattered showers. Highs 76 to 87 near the shore to around 69 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Waikoloa

Today: Breezy. Mostly sunny with isolated showers in the morning, then partly sunny in the afternoon. Highs 84 to 89 near the shore to 67 to 74 above 4000 feet. Northeast winds up to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Breezy. Lows around 75 near the shore to around 56 above 4000 feet. East winds up to 20 mph.

Monday: Mostly sunny in the morning then becoming partly sunny. Highs 84 to 90 near the shore to 67 to 74 above 4000 feet. Northeast winds up to 15 mph shifting to the north in the afternoon.

Detailed Forecast

Synopsis

A high pressure system far north of the Hawaiian Islands will continue to gradually weaken and slowly drift west over the next several days. Trade winds will continue to blow at moderate to locally breezy levels today, and then decrease to more moderate wind speeds from Monday through Friday. A slight increase in cloud and shower trends remains in the forecast through the morning hours as a weak easterly wave continues to move through the islands. Otherwise, a high pressure ridge aloft will hover over the island chain this week, producing strong subsidence with stable conditions limiting shower activity.

Discussion

A weak easterly wave will slowly drift through the western islands this morning keeping a slight enhancement in the morning shower activity in the forecast. The trough will weaken and drift away from the state later this afternoon and evening as a more stable high pressure ridge build back in over the islands.
Expect more stable conditions under this ridge pattern with lower subsidence temperature inversion heights in the 4,000 to 6,000 foot range capping vertical cloud development and producing a sharp decrease in clouds and showers statewide. This drier weather pattern will continue through the week with only brief periods of showers over windward and mountain areas in the forecast, favoring the overnight to early morning hours. Upper level cirrus clouds associated with a subtropical jet stream will drift over the islands this week, enhancing sunrise and sunset colors.
The high pressure system far north of the islands will continue on its westward journey away from the state this week. Global models suggest a cut off low will embed itself in the broader ridge north of the state. This weaker ridge pattern will keep trade winds in the gentle to moderate range from Monday afternoon through Friday. In the extended range forecast, yet another high center builds in far northeast of the Hawaii region by Saturday with a slight increase to our trade wind speeds just in time for next weekend.

Aviation

Breezy trade winds will continue through tonight. Low clouds and showers will favor windward and mauka areas, particularly this morning, with a few showers spilling leeward at times. Conditions should improve in most areas by this afternoon.
AIRMET Sierra remains in effect for mountain obscuration over windward sections of Kauai Oahu Molokai and Maui. Condition should improve later this morning in most areas.
AIRMET Tango remains in effect for moderate low level turbulence over and downwind of the terrain of all islands. This AIRMET will likely continue through the day.

Marine

Strong surface high pressure north of the state will maintain fresh to locally strong trades through tonight. Thus, a Small Craft Advisory has been extended for the typical windier areas around Maui County and the Big Island through tonight. Trade wind speeds look to generally decrease into the gentle to fresh range by Monday as the aforementioned high drifts west.
A small, medium period south swell will continue to provide small surf along south facing shores today. A small long period south southwest swell (200 degrees) is forecast to arrive towards the middle of the week, which will bump up surf along south facing shores.
Surf along east facing shores will remain choppy with short period wind waves before slowly declining with the trade winds on Monday. Local wind swell may wrap into select north and south facing shores through the day. A tiny background west northwest swell could arrive late Tuesday into Wednesday providing a small bump for north facing shores.

Fire weather

Breezy trade winds and low relative humidity will keep elevated fire weather concerns over leeward areas today. Locations such as West Maui and leeward Kohala on the Big Island are of particular concern. Trade winds will remain in the moderate to breezy range today, and then trend down to more moderate levels from Monday through Friday as the pressure gradient over the state relaxes.
Most leeward areas will remain dry. Brief periods of showers will move into windward areas mainly in the overnight hours. Humidity levels will see good to excellent overnight recoveries. Exceptions to this humidity rule will be for elevations in the 4,000 to 8,000 foot range, which may see periods of warmer temperatures with much drier conditions, within and above the subsidence temperature inversion level.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Monday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast 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