Hilo

Today: Mostly cloudy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 83 to 89 near the shore to around 73 at 4000 feet. Northeast winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 69 near the shore to around 54 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Sunday: Mostly cloudy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 80 to 86 near the shore to around 70 at 4000 feet. Northeast winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Kona

Today: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 82 to 87 near the shore to around 70 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 70 to 75 near the shore to around 55 near 5000 feet. Light winds. Chance of rain 20 percent.

Sunday: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 84 to 90 near the shore to around 71 near 5000 feet. East winds up to 10 mph shifting to the west in the afternoon. Chance of rain 20 percent.

Waimea

Today: Windy. Partly sunny with isolated showers. Highs around 83 near the shore to around 79 near 3000 feet. East winds 10 to 30 mph. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with isolated showers. Lows around 69 near the shore to 57 to 62 near 3000 feet. East winds 10 to 20 mph. Chance of rain 20 percent.

Sunday: Breezy. Partly sunny with isolated showers. Highs 65 to 85. East winds 10 to 20 mph. Chance of rain 20 percent.

Kohala

Today: Windy. Partly sunny with isolated showers. Highs around 83 near the shore to around 79 near 3000 feet. East winds 10 to 30 mph. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with isolated showers. Lows around 69 near the shore to 57 to 62 near 3000 feet. East winds 10 to 20 mph. Chance of rain 20 percent.

Sunday: Breezy. Partly sunny with isolated showers. Highs 65 to 85. East winds 10 to 20 mph. Chance of rain 20 percent.

South Big Island

Today: Mostly sunny. Breezy. Highs around 86 near the shore to around 71 near 5000 feet. East winds up to 25 mph.

Tonight: Partly cloudy. Lows around 70 near the shore to around 53 near 5000 feet. East winds 10 to 15 mph.

Sunday: Mostly sunny. Breezy. Highs around 86 near the shore to around 70 near 5000 feet. East winds 10 to 20 mph.

Puna

Today: Mostly cloudy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 83 to 89 near the shore to around 73 at 4000 feet. Northeast winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 69 near the shore to around 54 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Sunday: Mostly cloudy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 80 to 86 near the shore to around 70 at 4000 feet. Northeast winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Waikoloa

Today: Mostly sunny. Breezy. Highs 83 to 88 near the shore to 70 to 76 above 4000 feet. Northeast winds up to 25 mph.

Tonight: Partly cloudy. Lows around 73 near the shore to 51 to 58 above 4000 feet. Northeast winds 10 to 15 mph.

Sunday: Mostly sunny. Highs 84 to 91 near the shore to 68 to 76 above 4000 feet. East winds 10 to 15 mph shifting to the north in the afternoon. Gusts up to 35 mph.

Detailed Forecast

Synopsis

A large area of high pressure generally north of the Hawaiian Islands will hold the next several days. This will maintain the ongoing typically dry summertime trade wind pattern. Thicker more areal coverage clouds and more frequent showers will continue to favor more windward exposures and mauka zones. The next decent chance of more island-wide rain may be early next week in response to a vicinity upper level disturbance northeast of the state.

Discussion

There is little variance in forecast philosophy under this near static Central Pacific synoptic pattern. Summertime dry trades persist as a pair of highs centered northwest and northeast of the islands drive primarily fresh to locally strong easterlies. Relatively lower inversion 5-6k foot heights will result in a more shallow boundary layer, in tandem with dry mid to upper level moisture (< 30% RH) advecting in across the chain, nearly guarantees a stable enough island environment that will generally support windward and mauka cloudier skies and occasional showers. The usual suspect caveats of cloudier, slightly more wet afternoon Kona and Ka'u slope conditions with infrequent leeward sprinkles and partly cloudy skies riding over local area ridge tops still apply.
The development of an upper level disturbance forming in the middle of northern ridging will be the impetus of gradually weakening trades. The reflection of lowering surface pressures, along with the proximity of a subtropical jet, may work in favor of increasing more areawide pockets of better organized early week shower activity. The main question marks to increased shower activity will be whether or not there will 1) be ample column moisture within a deepened, marginally-destabilized boundary layer and 2) the location of the upper disturbance in relation to the islands. The wettest period is shaping up to be on Days 6 & 7 (next Thursday and Friday). This is the time at which inversions are slightly higher (closer to 6.5k ft), lapse rates are the greatest (5 to 6 deg C in lowest 3 km) and moisture is highest (> 80% RH). These three elements best come in-line over Big Island and Maui Counties in closing out the traditional work week.

Aviation

Breezy to locally windy trades will continue for the next few days. SHRA and low cigs will favor windward and mauka locations. Brief MVFR conds are possible in any SHRA. VFR conds should generally prevail.
AIRMET Sierra for mtn obsc remains in effect for N thru SE sections of Kauai, Oahu, Molokai, Maui and the Big Island.
AIRMET Tango for mod low-level turb lee of island terrain will remain in effect for the next several days due to the strong trades.

Marine

A strong high pressure ridge north of the Hawaiian Islands will continue to keep fresh to strong trade winds in the forecast through the weekend and into much of next week. Typical windier channel areas will see wind speeds near gale forecast at times with seas approaching 10 foot advisory levels. A Small Craft Advisory (SCA) remains in effect for all Hawaiian Coastal Waters through early Sunday morning. A subtle decrease in the trade winds are forecast by early next week. The SCA winds will linger in more than just the typical windier waters for most of next week.
A more significant long period south swell will fill in late tonight, reaching High Surf Advisory (HSA) levels for south facing shores on Sunday and Monday. West facing shores will see a decent south swell wrap, boosting surf heights as well, with the Big Island west facing shores likely reaching HSA levels on Sunday. A gradual downward trend is expected Tuesday through midweek.
Due to the strong trade winds upstream of the state, surf along east facing shores will remain rough and choppy through early next week. A downward trend is possible around midweek as the upstream fetch weakens and the local trades begin to ease.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Sunday for all Hawaiian 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