Photo Credit: James Grenz

Hilo

Today: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 78 to 86 near the shore to around 69 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers. Lows 61 to 70 near the shore to around 55 at 4000 feet. Northeast winds up to 10 mph in the evening becoming light. Chance of rain 40 percent.

Sunday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 79 to 85 near the shore to around 69 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 40 percent.

Kona

Today: Partly sunny. Isolated showers in the afternoon. Highs 82 to 88 near the shore to around 69 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy with isolated showers. Lows around 72 near the shore to 49 to 55 near 5000 feet. West winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Sunday: Mostly sunny in the morning then becoming mostly cloudy. Isolated showers. Highs 82 to 88 near the shore to 66 to 71 near 5000 feet. Northwest winds around 10 mph shifting to the west in the afternoon. Chance of rain 20 percent.

Waimea

Today: Mostly sunny with isolated showers. Highs 66 to 84. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with scattered showers. Lows 61 to 70 near the shore to 53 to 60 near 3000 feet. East winds 10 to 15 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Sunday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 65 to 85. East winds 10 to 15 mph. Chance of rain 50 percent.

Kohala

Today: Mostly sunny with isolated showers. Highs 66 to 84. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with scattered showers. Lows 61 to 70 near the shore to 53 to 60 near 3000 feet. East winds 10 to 15 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Sunday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 65 to 85. East winds 10 to 15 mph. Chance of rain 50 percent.

South Big Island

Today: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 85 near the shore to around 67 near 5000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Lows around 73 near the shore to around 52 near 5000 feet. East winds 10 to 15 mph.

Sunday: Mostly sunny in the morning then becoming partly sunny. Highs around 84 near the shore to around 67 near 5000 feet. East winds 10 to 15 mph.

Puna

Today: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 78 to 86 near the shore to around 69 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers. Lows 61 to 70 near the shore to around 55 at 4000 feet. Northeast winds up to 10 mph in the evening becoming light. Chance of rain 40 percent.

Sunday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 79 to 85 near the shore to around 69 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 40 percent.

Waikoloa

Today: Mostly sunny. Highs 83 to 88 near the shore to 65 to 75 above 4000 feet. Northeast winds 10 to 15 mph shifting to the northwest in the afternoon.

Tonight: Partly cloudy. Lows around 73 near the shore to around 53 above 4000 feet. East winds 10 to 15 mph.

Sunday: Mostly sunny. Highs 83 to 89 near the shore to 66 to 74 above 4000 feet. North winds 10 to 15 mph.

Detailed Forecast

Synopsis

A stable moderate trade wind pattern with mainly light windward showers will prevail through Monday. Increasing trade winds and slightly wetter conditions are possible during the middle of next week, with breezy trades continuing into the weekend.

Discussion

Little change to the overall forecast philosophy overnight. The latest high-res models and early morning radar imagery show less in the way of showers this morning and through the rest of the weekend. In addition, the 12Z soundings from Hilo and Lihue show increasing stability across the state with inversion heights around 4500-5500 feet, about 1000 feet lower than yesterday at this time. Therefore, have trended PoPs and QPF down slightly to follow these trends.
A surface ridge far north of the islands will maintain the current trade wind regime through the upcoming week. A developing surface high far northeast of the state will strengthen the local pressure gradient over the islands by the middle of next week, resulting in an increase to breezy trade wind speeds. A mid- to upper-level ridge over the islands will maintain the relatively dry and stable conditions through this weekend. Any showers that do reach the islands should only produce modest rainfall amounts and are expected to be focused over the windward slopes, with a few showers possible over the leeward slopes of the Big Island each afternoon.
The GFS and ECMWF continue to show an increase in precipitable water reaching the islands Tuesday or so, although the focus has shifted a bit towards the southern end of the state. Expect a few more showers over the windward sides of the smaller islands, and a bit more of an uptick over windward Big Island. The increase in trade wind speeds during that time will allow some of those showers to reach some leeward areas at times.

Aviation

Moderate to locally breezy trade winds are expected through the rest of the weekend. Low cigs, SHRA and MVFR conds should favor windward and mauka areas, with some spillover into leeward areas. Otherwise conds should remain mainly VFR.
No AIRMETs are currently in effect.

Marine

Gentle to locally fresh trades continue through Saturday, then become locally strong during the first half of next week. This will likely warrant a Small Craft Advisory for the typically windy zones around Maui County and the Big Island.
Surf remains small along all shorelines through the forecast period. Mixed swell out of the southerly quadrant will maintain small surf along south-facing shores tonight and will maintain slightly perturbed conditions through much of next week.
Likewise, small surf persists for northern exposures, although mixed swells out of the northerly quadrant may provide a small bump for the weekend.
A short period NE swell will maintain small surf along east-facing shores even as background trade wind swell subsides. Choppy conditions then return as trades strengthen next week.
The combination of higher than normal water levels and afternoon spring tides are resulting in water levels running over half a foot above guidance around the Big Island and Maui. This will cause minor coastal flooding issues for both Big Island and Maui into the weekend mainly during afternoon peak high tide. Coastal Flood Conditions are borderline around Maui and the Coastal Flood Statement may be dropped there sooner than the Big Island coastal zones.

HFO Watches/Warnings/Advisories

None.

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Data Courtesy of NOAA.gov