Photo Credit: James Grenz

Hilo

Today: Partly sunny. Breezy. Showers likely in the morning, then scattered showers in the afternoon. Highs around 81 near the shore to 66 to 71 at 4000 feet. Northeast winds up to 20 mph shifting to the east 10 to 20 mph in the afternoon. Gusts up to 40 mph. Chance of rain 70 percent.

Tonight: Cloudy with showers likely. Lows 66 to 73 near the shore to around 54 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Monday: Mostly cloudy. Showers likely in the morning, then scattered showers in the afternoon. Highs around 81 near the shore to 66 to 71 at 4000 feet. East winds up to 15 mph. Chance of rain 70 percent.

Kona

Today: Sunny in the morning, then mostly cloudy with scattered showers in the afternoon. Highs 79 to 84 near the shore to around 66 near 5000 feet. Light winds. Chance of rain 50 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then isolated showers after midnight. Lows around 70 near the shore to around 54 near 5000 feet. Light winds. Chance of rain 50 percent.

Monday: Mostly cloudy. Isolated showers in the morning, then scattered showers in the afternoon. Highs 79 to 84 near the shore to around 66 near 5000 feet. Light winds. Chance of rain 50 percent.

Waimea

Today: Windy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs around 79 near the shore to 66 to 76 near 3000 feet. East winds 10 to 30 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 69 near the shore to 54 to 62 near 3000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.

Monday: Mostly cloudy. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 79 near the shore to 66 to 76 near 3000 feet. East winds up to 20 mph. Gusts up to 40 mph in the morning. Chance of rain 50 percent.

Kohala

Today: Windy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs around 79 near the shore to 66 to 76 near 3000 feet. East winds 10 to 30 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 69 near the shore to 54 to 62 near 3000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.

Monday: Mostly cloudy. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 79 near the shore to 66 to 76 near 3000 feet. East winds up to 20 mph. Gusts up to 40 mph in the morning. Chance of rain 50 percent.

South Big Island

Today: Mostly sunny. Windy. Isolated showers in the afternoon. Highs around 83 near the shore to around 70 near 5000 feet. East winds 10 to 30 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Breezy. Lows around 71 near the shore to around 54 near 5000 feet. Northeast winds 10 to 25 mph.

Monday: Mostly cloudy. Breezy. Isolated showers in the afternoon. Highs around 83 near the shore to around 70 near 5000 feet. East winds 10 to 20 mph. Chance of rain 20 percent.

Puna

Today: Partly sunny. Breezy. Showers likely in the morning, then scattered showers in the afternoon. Highs around 81 near the shore to 66 to 71 at 4000 feet. Northeast winds up to 20 mph shifting to the east 10 to 20 mph in the afternoon. Gusts up to 40 mph. Chance of rain 70 percent.

Tonight: Cloudy with showers likely. Lows 66 to 73 near the shore to around 54 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Monday: Mostly cloudy. Showers likely in the morning, then scattered showers in the afternoon. Highs around 81 near the shore to 66 to 71 at 4000 feet. East winds up to 15 mph. Chance of rain 70 percent.

Waikoloa

Today: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs around 83 near the shore to 67 to 73 above 4000 feet. North winds up to 25 mph with gusts to 45 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Lows 68 to 73 near the shore to 49 to 59 above 4000 feet. East winds up to 15 mph.

Monday: Mostly cloudy. Isolated showers in the afternoon. Highs around 83 near the shore to 67 to 73 above 4000 feet. East winds up to 15 mph shifting to the north in the afternoon. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Strong and gusty easterly trade winds will continue into Monday, with clouds and showers favoring windward and mauka locations as pockets of moisture move through. Expect some showers to carry over into leeward areas periodically with the strong winds in place. Increasing moisture and diminishing trade winds could lead to better cloud and shower coverage Monday through Tuesday as an upper disturbance moves into the area. Trades will surge back Wednesday through the second half of the week as high pressure builds north of the area.

Discussion

Guidance shows the strong easterly trades holding into Monday as 1034 mb high pressure passes to the north. Gusts reaching the 40 to 50 mph range are expected in the windier locations of Maui County and the Big Island today, especially through the afternoon hours. Showers will favor the typical windward and mountain locations as pockets of moisture move through, with some reaching our dry leeward areas periodically. Similar gusts mixing down in and around these showers can be expected statewide today.
Trade winds will ease early in the week as the ridge weakens in response to a cold front passing far to the north. A mid to upper level trough west of the state will gradually erode the mid level ridge over the islands, resulting in thickening high clouds tonight and Monday. As the upper trough moves overhead on Tuesday, shower activity may increase.
Trade winds rebuild on Wednesday and Thursday as another North Pacific high passes far north of the state. The upper-level trough will fill, leading to thinning high clouds, and a typical trade wind weather pattern will prevail. Looking toward next weekend, trades may shift southeasterly as the surface high moves off to the east and a front develops northwest of the state.

Aviation

Strong and gusty trade winds will continue during the next 24 hours at the TAF sites. Showers will favor windward and mauka areas, bringing MVFR cigs and vsbys at times as they move through. A few showers will spread leeward at times, but VFR conditions should prevail in these areas.
AIRMET Sierra remains in effect for mountain obscuration across windward sections of the Big Island. Conditions are expected to improve later this morning.
AIRMET Tango remains in effect for moderate low level turbulence over and downwind of the terrain of all islands. This AIRMET will likely remain in place through the day. AIRMET Tango may also be needed for some moderate upper level turbulence moving northward into the islands later this morning.

Marine

A strong surface high pressure system far north of the islands is moving slowly eastward. The tight pressure gradient south of this feature continues to generate strong and gusty trade winds across the state early this morning. In addition, the combined seas are elevated and rough across those waters exposed to the strong trade winds and a fading northwest swell. As a result, a Small Craft Advisory (SCA) is in effect for all Hawaiian waters through early Monday morning. We are expecting the wind speeds and seas to trend down on Monday, so the SCA has been scaled back to only include the typically windier waters adjacent to the islands of Maui County and the Big Island during the day on Monday. The trade winds are expected to ease from Monday night into mid-week due to the high weakening once it is far northeast of the state and a frontal boundary moves down toward the area from the north- northwest. This boundary is expected to stall and weaken north of the state by late Wednesday. Locally strong trade winds may return Thursday as a new surface high builds far north of the area.
The current northwest swell will continue to gradually lower through Tuesday. A small northwest swell and a short-period north-northwest swell will likely produce modest surf along most north and west facing shores during the middle of next week. The strong trade winds will maintain slightly elevated, rough surf along east facing shores through early Monday. The weakening trade winds will allow the surf to gradually lower along east facing shores from late Monday into Wednesday. Background south swell energy will maintain small, near seasonal surf heights along most south facing shores.

HFO Watches/Warnings/Advisories

Wind Advisory until 6 PM HST this evening for Lanai Mauka, Kahoolawe, Maui Windward West, Maui Leeward West, Kohala, Big Island Interior, Lanai Windward, Lanai Leeward, Lanai South, Maui Central Valley North, Maui Central Valley South, Windward Haleakala, Kipahulu, South Maui/Upcountry, South Haleakala, Big Island South, Big Island Southeast, Big Island North.
Small Craft Advisory until 6 PM HST Monday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.
Small Craft Advisory until 6 AM HST Monday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Oahu Leeward Waters, Kaiwi Channel, Maui County Windward Waters, Maui County Leeward Waters, Big Island 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