Photo Credit: James Grenz

Hilo

Today: Partly sunny with scattered showers. Highs around 85 near the shore to 70 to 75 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows around 69 near the shore to around 55 at 4000 feet. North winds up to 15 mph. Chance of rain 50 percent.

Sunday: Mostly sunny with scattered showers. Highs around 86 near the shore to 70 to 75 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 40 percent.

Kona

Today: Mostly sunny in the morning, then mostly cloudy with isolated showers in the afternoon. Highs 83 to 88 near the shore to around 70 near 5000 feet. Light winds becoming southwest up to 10 mph in the afternoon. Chance of rain 20 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Isolated showers. Lows 70 to 76 near the shore to around 56 near 5000 feet. Light winds. Chance of rain 20 percent.

Sunday: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs 83 to 88 near the shore to around 70 near 5000 feet. Light winds. Chance of rain 20 percent.

Waimea

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 83 near the shore to 70 to 80 near 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with isolated showers. Lows around 69 near the shore to 57 to 63 near 3000 feet. East winds up to 15 mph increasing to 10 to 15 mph after midnight. Chance of rain 20 percent.

Sunday: Mostly sunny with isolated showers. Highs around 84 near the shore to 70 to 81 near 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Kohala

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 83 near the shore to 70 to 80 near 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with isolated showers. Lows around 69 near the shore to 57 to 63 near 3000 feet. East winds up to 15 mph increasing to 10 to 15 mph after midnight. Chance of rain 20 percent.

Sunday: Mostly sunny with isolated showers. Highs around 84 near the shore to 70 to 81 near 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

South Big Island

Today: Mostly sunny in the morning, then mostly cloudy with isolated showers in the afternoon. Highs around 87 near the shore to around 74 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy in the evening then becoming mostly clear. Lows around 71 near the shore to around 54 near 5000 feet. East winds up to 15 mph.

Sunday: Sunny in the morning then becoming partly sunny. Highs around 87 near the shore to around 74 near 5000 feet. East winds up to 15 mph.

Puna

Today: Partly sunny with scattered showers. Highs around 85 near the shore to 70 to 75 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows around 69 near the shore to around 55 at 4000 feet. North winds up to 15 mph. Chance of rain 50 percent.

Sunday: Mostly sunny with scattered showers. Highs around 86 near the shore to 70 to 75 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 40 percent.

Waikoloa

Today: Sunny and breezy. Highs around 87 near the shore to 71 to 77 above 4000 feet. Northeast winds up to 20 mph.

Tonight: Mostly clear. Lows 71 to 76 near the shore to 52 to 59 above 4000 feet. East winds up to 15 mph.

Sunday: Mostly sunny. Highs around 87 near the shore to 71 to 77 above 4000 feet. Northeast winds up to 15 mph.

Detailed Forecast

Synopsis

Rather dry trade wind weather will prevail through the weekend, with brief showers favoring mainly windward and mauka areas. The trade winds will increase slightly beginning late Sunday and become breezy Monday through Tuesday as the remnant trough of former Tropical Cyclone Fernanda passes by to the south of the state. Deep tropical moisture associated with Fernanda will move into the eastern islands late Sunday night, and spread to the rest of the state Monday and Monday night. Wet weather and locally heavy rainfall can be expected across windward areas, particularly windward Maui and the Big Island, with leeward portions of all islands seeing some rain as well. A drier and more typical trade wind pattern is expected Tuesday night through late next week.

Discussion

Currently at the surface, a 1033 mb high is centered around 1950 miles north-northeast of Honolulu, while the remnant trough of Greg is located around 875 miles southwest of Kauai and the remnant low of Fernanda is located around 875 miles east-southeast of the Big Island. The gradient locally continues to produce moderate trade winds in unsheltered areas early this morning. Infrared satellite imagery shows mostly clear to partly cloudy conditions in most areas. Radar imagery shows isolated to scattered showers moving into windward areas, with a few decaying showers or a few sprinkles reaching leeward areas at times. Main forecast focus continues to revolve around the potential for some heavier rainfall associated with the remnants of Fernanda early next week.
Moderate trade winds will hold in place through the weekend, with a slight increase expected late Sunday as the remnant trough of former Tropical Cyclone Fernanda approaches from the east. The trades will strengthen to breezy levels Monday and Tuesday as the remnant trough of Fernanda slides by to the south of the state, then hold at breezy levels through late next week as strong high pressure builds to the distant north-northeast.
As for the remaining weather details, very little change to the overall weather forecast is expected during the next couple days, with rather dry trade wind weather prevailing. There will be some light showers affecting windward and mauka areas, particularly at night and during the early morning hours each day, with mostly dry conditions persisting in leeward locales.
The persistent dry pattern we've been experiencing for quite some time appears to come to an abrupt halt beginning late Sunday night over the eastern end of the state as deep tropical moisture associated with the remnant trough of Fernanda moves in. The deep tropical moisture will spread westward across the state Monday and Monday night. Periods of wet weather with locally heavy rainfall can be expected in windward areas as the remnants of Fernanda move through, and even leeward communities will see some rainfall, although the rain shadowing effects of the terrain should limit rainfall totals here. The deepest moisture and highest chances for heavy rainfall appear to be over windward sections of the Big Island and perhaps windward Maui at this time.
Drier conditions are forecast to move in from east to west across the island chain on Tuesday, with typical trade wind weather featuring brief windward and mauka showers and the occasional leeward spillover then prevailing Tuesday night through late next week.

Aviation

Mostly dry conditions, with scattered clouds favoring north through east sections of the islands, will persist through the weekend. Expect cloud cover to reform along the Kona slopes of the Big Island this afternoon before diminishing again tonight. Although a diurnal increase in shower activity is possible this morning across windward locations, VFR conditions will prevail through the forecast period for most locations. Moderate trade winds will continue through Sunday.
There are currently no AIRMETs, and none are anticipated at this time.

Marine

Surface high pressure moving far north and northeast of the islands will result in moderate to locally fresh trade winds through Sunday. The remnants of Fernanda will pass south of the islands Monday and this will help strengthen trades to generally fresh to locally strong magnitudes through the remainder of next week. This will likely prompt Small Craft Advisories for the typical windier waters around Maui County and Big Island.
East-facing shore surf will remain below normal through the weekend due to lighter trades upstream of the state. Short period east wind wave swell generated by the remnants of Fernanda, along with long period east swell generated from Hurricane Hilary currently moving west of the southern tip of Baja California Sur, will likely increase eastern shore surf from Monday night through Wednesday. East-facing shore surf heights are forecast to peak out below surf advisory thresholds Tuesday night into Wednesday morning as this triple shot of locally-generated trade wind wave swell and swells from both Fernanda and Hilary arrive. South shore surf will remain small through the day with a small, medium period swell arriving early next week.

HFO Watches/Warnings/Advisories

None.

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Data Courtesy of NOAA.gov