Hilo

Tonight: Mostly cloudy with scattered showers. Lows 62 to 70 near the shore to 53 to 58 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 40 percent.

Tuesday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 78 to 85 near the shore to 63 to 69 at 4000 feet. North winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Tuesday Night: Mostly cloudy with scattered showers. Lows 62 to 70 near the shore to 53 to 59 at 4000 feet. North winds up to 15 mph. Chance of rain 50 percent.

Kona

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 73 near the shore to 48 to 54 near 5000 feet. Light winds. Chance of rain 20 percent.

Tuesday: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs 83 to 89 near the shore to 66 to 71 near 5000 feet. Light winds. Chance of rain 20 percent.

Tuesday Night: Mostly cloudy. Isolated showers in the evening. Lows around 73 near the shore to 48 to 54 near 5000 feet. Light winds. Chance of rain 20 percent.

Waimea

Tonight: Partly cloudy with isolated showers. Lows 62 to 71 near the shore to 54 to 61 near 3000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Tuesday: Mostly sunny with isolated showers. Highs 65 to 84. East winds up to 15 mph. Chance of rain 20 percent.

Tuesday Night: Partly cloudy in the evening then becoming mostly cloudy. Isolated showers. Lows 62 to 71 near the shore to 55 to 61 near 3000 feet. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Kohala

Tonight: Partly cloudy with isolated showers. Lows 62 to 71 near the shore to 54 to 61 near 3000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Tuesday: Mostly sunny with isolated showers. Highs 65 to 84. East winds up to 15 mph. Chance of rain 20 percent.

Tuesday Night: Partly cloudy in the evening then becoming mostly cloudy. Isolated showers. Lows 62 to 71 near the shore to 55 to 61 near 3000 feet. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

South Big Island

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 73 near the shore to around 52 near 5000 feet. Northeast winds up to 15 mph in the evening becoming light. Chance of rain 20 percent.

Tuesday: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 85 near the shore to around 68 near 5000 feet. Southeast winds up to 10 mph. Chance of rain 20 percent.

Tuesday Night: Mostly cloudy. Isolated showers in the evening. Lows around 73 near the shore to around 52 near 5000 feet. Light winds. Chance of rain 20 percent.

Puna

Tonight: Mostly cloudy with scattered showers. Lows 62 to 70 near the shore to 53 to 58 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 40 percent.

Tuesday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 78 to 85 near the shore to 63 to 69 at 4000 feet. North winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Tuesday Night: Mostly cloudy with scattered showers. Lows 62 to 70 near the shore to 53 to 59 at 4000 feet. North winds up to 15 mph. Chance of rain 50 percent.

Waikoloa

Tonight: Mostly clear. Isolated showers in the evening. Lows 71 to 76 near the shore to 51 to 56 above 4000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Tuesday: Mostly sunny. Isolated showers in the afternoon. Highs 83 to 90 near the shore to 67 to 72 above 4000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

Tuesday Night: Partly cloudy. Isolated showers in the evening. Lows around 74 near the shore to 51 to 56 above 4000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A weak upper-level low over the state will help enhance windward showers into the first half of the week, before drifting northeast away from the island chain. More stable trade wind weather returns Tuesday, with brief periods of passing showers favoring windward and mountain areas through next weekend.

Discussion

Visible satellite imagery this afternoon shows mainly scattered clouds over and around the islands moving in on the trades, while radar imagery shows only isolated light showers impacting some windward areas at times. Water vapor satellite imagery depicts a weak upper- level low centered around 50 miles northeast of Maui County this morning as well. The weakness of this low has prevented the development of thunderstorms over the past couple of days, so this system will merely act to slightly enhance local windward and mountain shower activity into Tuesday morning. However, due to an area of dry air seen moving west into the state on the CIMSS MIMIC precipitable water imagery, rainfall amounts are expected to be on the lighter side.
Far north of the Hawaiian Islands, the subtropical ridge will reestablish itself, but remain a bit subdued this week, as a series of cold frontal systems moving across the north central Pacific Ocean moderate the ridge intensity. As a result, trade wind speeds will remain gentle to locally breezy tonight into next weekend. The aforementioned upper low will slowly drift northeast away from the state over the next couple of days, allowing the return of a more typical trade pattern of brief passing showers for the next seven days. The focus will be mainly over the windward and mountain areas and favoring the overnight to early morning hours. Only subtle variations in the day to day moisture and rainfall patterns are shown in the model guidance for the next several days.

Aviation

A ridge strengthening to the north of the islands will support moderate to locally breezy trade winds over the next couple of days. Passing clouds and showers will bring brief periods of MVFR conditions mostly to windward and mauka areas.
No AIRMETs are currently in effect, and none are expected for today.

Marine

A surface ridge rebuilding far north of the state has led to fresh to locally strong trades today across the coastal waters. However, a slight weakening trend is expected this evening and tonight. Therefore, the Small Craft Advisory (SCA) has been cancelled for now. However, winds are expected to fluctuate near low-end SCA criteria in the windier channels for the next few days, so it is possible a new SCA will be needed over the next few days.
A small to moderate long-period north-northwest swell continues to result in elevated surf along north-facing shores, though it is peaking a few feet below advisory criteria. This swell will begin to gradually decline tonight and continue to slowly diminish through Thursday.
A long-period south swell has also resulted in above average surf along south-facing shores today, though still below advisory levels. This swell is also expected to slowly decline through mid-week. Guidance indicates that a smaller long-period south swell will fill in on Thursday, hold through Friday, and then gradually decline this weekend.
Surf along west-facing shores will be influenced by a mix of both the north-northwest and south swells through mid-week. Surf along east-facing shores will be rough and choppy as trades fluctuate throughout the week.

HFO Watches/Warnings/Advisories

None.

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Data Courtesy of NOAA.gov