Hilo

Today: Mostly cloudy 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 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 67 near the shore to around 53 at 4000 feet. North winds up to 10 mph shifting to the west after midnight. Chance of rain 50 percent.

Wednesday: Partly sunny with scattered showers. Highs around 86 near the shore to 70 to 75 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Kona

Today: Sunny with isolated showers 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. West winds up to 10 mph. Chance of rain 50 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows 68 to 75 near the shore to around 54 near 5000 feet. Light winds. Chance of rain 20 percent.

Wednesday: 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. West winds up to 10 mph. Chance of rain 50 percent.

Waimea

Today: Mostly cloudy with scattered showers. Highs around 84 near the shore to 70 to 81 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 67 near the shore to 55 to 61 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Wednesday: Partly sunny with scattered showers. Highs around 84 near the shore to 70 to 81 near 3000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Kohala

Today: Mostly cloudy with scattered showers. Highs around 84 near the shore to 70 to 81 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 67 near the shore to 55 to 61 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Wednesday: Partly sunny with scattered showers. Highs around 84 near the shore to 70 to 81 near 3000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

South Big Island

Today: Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 87 near the shore to around 74 near 5000 feet. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 69 near the shore to around 52 near 5000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

Wednesday: Breezy. Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 87 near the shore to around 74 near 5000 feet. East winds up to 20 mph. Chance of rain 40 percent.

Puna

Today: Mostly cloudy 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 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 67 near the shore to around 53 at 4000 feet. North winds up to 10 mph shifting to the west after midnight. Chance of rain 50 percent.

Wednesday: Partly sunny with scattered showers. Highs around 86 near the shore to 70 to 75 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Waikoloa

Today: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs around 87 near the shore to 71 to 77 above 4000 feet. North winds up to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with isolated showers. Lows 69 to 75 near the shore to 50 to 57 above 4000 feet. Southeast winds up to 15 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 87 near the shore to 71 to 77 above 4000 feet. North winds up to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

A wet pattern will linger through much of the week over the eastern end of the state where an old frontal boundary lingers. Drier and more stable conditions with moderate northeast trades will continue over the western end through midweek. Trades will diminish Thursday through the upcoming weekend as a front stalls north of the islands. This combined with an area of tropical moisture moving up the island chain from the southeast will support a wet pattern setting up for much of the state this weekend.

Discussion

Guidance remains in good agreement and shows the moisture axis associated with an old frontal boundary lingering over Maui County and the Big Island through midweek. This combined with broad upper troughing over the region will support a wet pattern persisting for these areas. Similar to what was observed yesterday afternoon, some showers could become heavy at times and thunderstorm or two can't be completely ruled out through the peak heating hours. For the western end of the state, expect the stable and drier conditions with moderate northeast trades to continue.
For the extended period (Thursday through the weekend), guidance remains in decent agreement and shows a broad cut off upper low setting up far north of the islands due to a blocking pattern over the west coast. The attendant cold front is shown dropping southward and stalling near or just north of the state by Friday. This pattern will translate to a land and sea breeze regime evolving statewide. The upper trough over the region combined with deep tropical moisture pulling up from the southeast and potentially the moisture axis associated with the tail-end of the frontal boundary clipping Kauai will lead to a wet pattern unfolding for most areas this weekend. Showers will favor interior and leeward areas through the afternoon and early evening hours with the sea breezes.

Aviation

Moisture associated with the weakening front which has stalled over the eastern end of the state, continues to generate scattered to numerous showers from the central smaller islands to the Big Island. These showers will continue through today. Otherwise, limited moisture on the backside of the stalled front, will limit showers and maintain mainly VFR conds over Kauai and Oahu.
The deeper moisture remaining anchored near the Big Island will continue MVFR conditions and the need for AIRMET Sierra, due to tempo mountain obscuration across the Big Island and some windward locations of the smaller islands today.

Marine

A front over the area will gradually dissipate through today. Moderate northeast to east winds will persist through the rest of the week.
A couple of small to moderate, medium-period swells with a northerly component will move through the islands this week. A new north-northeast swell has been filling in this morning. Surf with this swell will rise along north facing shores, peaking today, but is expected to remain below advisory levels. Concurrently, a small northwest swell will move through into mid- week. These two swells will subside through Thursday. A larger north swell is forecast to arrive late Thursday into Friday, boosting north shore surf to near advisory levels Friday and Saturday.
A small, medium period south swell will lower gradually through the middle of the week to background levels. A slightly larger bump in south swell is expected Friday or Saturday.
Weaker trades over and upwind of the state will keep east shore surf on the small side. Any slight increase in west or east shore surf would come from north-swell wrap.

HFO Watches/Warnings/Advisories

None.

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Data Courtesy of NOAA.gov