Hilo

Today: Partly sunny. Numerous showers in the morning, then scattered showers in the afternoon. Highs 78 to 83 near the shore to 65 to 72 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with numerous showers. Lows 62 to 70 near the shore to 53 to 58 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 70 percent.

Sunday: Partly sunny. Numerous showers in the morning, then scattered showers in the afternoon. Highs 77 to 83 near the shore to 64 to 72 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Kona

Today: Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 83 to 88 near the shore to around 70 near 5000 feet. Light winds. Chance of rain 40 percent.

Tonight: Mostly clear. Isolated showers in the evening. Lows 68 to 73 near the shore to 47 to 54 near 5000 feet. Light winds. Chance of rain 20 percent.

Sunday: Sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs 82 to 87 near the shore to around 70 near 5000 feet. Light winds. Chance of rain 20 percent.

Waimea

Today: Breezy. Partly sunny with scattered showers. Highs 67 to 84. East winds 10 to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 62 to 69 near the shore to 55 to 62 near 3000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.

Sunday: Breezy. Partly sunny with scattered showers. Highs 67 to 84. East winds 10 to 20 mph. Chance of rain 50 percent.

Kohala

Today: Breezy. Partly sunny with scattered showers. Highs 67 to 84. East winds 10 to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 62 to 69 near the shore to 55 to 62 near 3000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.

Sunday: Breezy. Partly sunny with scattered showers. Highs 67 to 84. East winds 10 to 20 mph. Chance of rain 50 percent.

South Big Island

Today: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs around 84 near the shore to around 68 near 5000 feet. East winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Isolated showers in the evening. Lows around 72 near the shore to around 51 near 5000 feet. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Sunday: Mostly sunny. Breezy. Highs around 83 near the shore to around 68 near 5000 feet. East winds up to 20 mph.

Puna

Today: Partly sunny. Numerous showers in the morning, then scattered showers in the afternoon. Highs 78 to 83 near the shore to 65 to 72 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with numerous showers. Lows 62 to 70 near the shore to 53 to 58 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 70 percent.

Sunday: Partly sunny. Numerous showers in the morning, then scattered showers in the afternoon. Highs 77 to 83 near the shore to 64 to 72 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Waikoloa

Today: Sunny and breezy. Highs 82 to 88 near the shore to 67 to 74 above 4000 feet. Northeast winds up to 20 mph.

Tonight: Mostly clear. Breezy. Isolated showers in the evening. Lows around 71 near the shore to 47 to 54 above 4000 feet. Southeast winds up to 20 mph. Gusts up to 40 mph in the evening. Chance of rain 20 percent.

Sunday: Sunny and breezy. Highs 82 to 87 near the shore to 67 to 73 above 4000 feet. Northeast winds up to 20 mph.

Detailed Forecast

Synopsis

Moderate to breezy easterly trade winds will continue today then slowly decrease in strength from Sunday through Tuesday. Expect passing showers in this trade wind pattern mainly over windward and mountain areas, favoring the overnight to early morning hours. Lighter winds are in the forecast from Tuesday onward with land and sea breezes developing over most islands from Wednesday into next weekend. Converging sea breeze winds will build clouds over island interior sections during the day with isolated showers possible.

Discussion

The satellite imagery this morning shows similar conditions as compared to last night with mostly stable cumulus clouds drifting from East to West on the trade winds. A few high level cirrus clouds will pass over the Big Island today.
In the larger scale pressure pattern a high pressure ridge north of the Hawaiian Islands remains in place producing moderate to breezy easterly trade winds today. This ridge will slowly weaken from Sunday onward as a series of cold frontal troughs pass by far north of the state. These frontal troughs will weaken the ridge north of the island chain, causing a weather pattern transition from trade winds lasting through Monday into a light wind pattern from Tuesday into next weekend. Light large scale winds will allow local scale land and sea breezes to develop over most islands from Wednesday onward.
Typical trade wind weather conditions will continue into Monday with passing showers mainly over the windward and mountain areas, favoring the overnight to early morning hours. Weather conditions will change starting on Tuesday with converging sea breezes over the western islands during the day producing interior clouds and isolated showers. Diverging down slope land breezes over each island at night will tend to clear out most of the clouds and showers.
The wind and weather grids were adjusted a bit from Tuesday onward to show more of a land and sea breeze weather regime over each island.

Aviation

Moderate to breezy easterly trade winds will continue through the weekend. Clouds and showers will favor windward and mauka locations, especially over the western end of the state where a band of moisture resides. MVFR CIGS/VSBYS will be possible in and around passing showers. Otherwise, VFR conditions will prevail.
AIRMET Tango remains in effect for tempo moderate turbulence below 8000 feet for areas downwind of the mountains of all islands.
AIRMET Sierra remains in effect for tempo mountain obscuration from low clouds and showers for north through east sections of Kauai. This will likely continue through the early morning hours before conditions begin to improve.

Marine

Surface high pressure north of the islands is providing a tight enough pressure gradient across the region to support these recent moderate to locally strong trade winds. The Small Craft Advisory has been extended further west to now include all local coastal zones except the windward Kauai, Oahu and Big Island waters through early Sunday morning. High pressure north of the chain will move closer to the state as series of east-moving lows ride over the top Central Pacific upper ridging. This will result in weaker trade flow early next week…moderate to locally fresh trades Sunday will trend down into the gentle to moderate range by next Tuesday.
The current north northeast swell will hold through the day with a short- lived slightly higher reinforcing northwest swell reaching the western most islands Sunday. Overall, a series of primarily small north northwest swells arriving through early next week will hold surf up along north and west facing shores through Monday. A moderate size, medium period northwest swell that is timed to reach the islands Thursday may lift surf along north and west facing shores back up to High Surf Advisory levels. Long period background south swell will maintain small surf along most south facing shores through Monday. A slightly larger, long period Southern Hemispheric swell that is now beginning to show up at the Samoa buoy this morning is scheduled to arrive next Tuesday and provide a small bump to south shore surf through mid week. Eastern facing shore surf will remain rough and choppy in response to recent fresh to locally strong trades. Weakening trades early next week will lower this eastern chop during the mid to later part of the week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Sunday for Kauai Northwest Waters, Kauai Leeward Waters, Kauai Channel, Oahu Leeward Waters, Kaiwi Channel, Maui County Windward Waters, Maui County Leeward Waters, Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

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Data Courtesy of NOAA.gov