Hilo

Today: Mostly sunny in the morning then becoming cloudy. Scattered showers. Highs around 84 near the shore to 68 to 73 at 4000 feet. North winds up to 10 mph. Chance of rain 30 percent.

Tonight: Cloudy with showers likely. Lows around 69 near the shore to around 55 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 70 percent.

Monday: Cloudy with scattered showers. Highs 80 to 85 near the shore to 65 to 72 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Kona

Today: Sunny in the morning, then mostly cloudy with scattered showers in the afternoon. Highs 81 to 86 near the shore to around 68 near 5000 feet. West winds up to 10 mph. Chance of rain 40 percent.

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

Monday: Mostly sunny in the morning, then mostly cloudy with scattered showers in the afternoon. Highs 83 to 90 near the shore to around 70 near 5000 feet. Light winds. Chance of rain 40 percent.

Waimea

Today: Mostly sunny with isolated showers in the morning, then mostly cloudy with scattered showers in the afternoon. Highs around 82 near the shore to 68 to 79 near 3000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 30 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then showers likely after midnight. 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 70 percent.

Monday: Mostly cloudy. Isolated showers in the morning, then scattered showers in the afternoon. Highs 66 to 86. East winds 10 to 15 mph. Chance of rain 50 percent.

Kohala

Today: Mostly sunny with isolated showers in the morning, then mostly cloudy with scattered showers in the afternoon. Highs around 82 near the shore to 68 to 79 near 3000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 30 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then showers likely after midnight. 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 70 percent.

Monday: Mostly cloudy. Isolated showers in the morning, then scattered showers in the afternoon. Highs 66 to 86. East winds 10 to 15 mph. Chance of rain 50 percent.

South Big Island

Today: Breezy. Sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 85 near the shore to around 72 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 71 near the shore to around 54 near 5000 feet. Northeast winds up to 15 mph becoming around 10 mph after midnight. Chance of rain 20 percent.

Monday: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 85 near the shore to around 69 near 5000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Puna

Today: Mostly sunny in the morning then becoming cloudy. Scattered showers. Highs around 84 near the shore to 68 to 73 at 4000 feet. North winds up to 10 mph. Chance of rain 30 percent.

Tonight: Cloudy with showers likely. Lows around 69 near the shore to around 55 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 70 percent.

Monday: Cloudy with scattered showers. Highs 80 to 85 near the shore to 65 to 72 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Waikoloa

Today: Breezy. Sunny in the morning, then mostly cloudy with isolated showers in the afternoon. Highs around 85 near the shore to 69 to 75 above 4000 feet. Northeast winds up to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows 71 to 76 near the shore to 52 to 59 above 4000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Monday: Sunny in the morning then becoming partly sunny. Highs 82 to 90 near the shore to 67 to 73 above 4000 feet. Northeast winds up to 10 mph.

Detailed Forecast

Synopsis

Moderate trades will focus showers over windward and mauka areas through mid-week. Locally heavy showers remain possible through today, thanks to a receding upper trough northeast of the islands. Expect breezy trades and greater shower coverage by late Wednesday through Thursday.

Discussion

An upper trough extending northeast from the main Hawaiian Islands enhanced showers across Puna district of the Big Island last evening, but this activity has diminished considerably this morning. The Big Island is mostly clear at this hour, while isolated to scattered moderate showers blown in by the trades affect windward areas of the smaller islands. With the upper trough expected to gradually retreat to the northeast away from the islands over the next few days, the probability for thunderstorm and heavy shower development drops too low to include in the forecast with confidence. Expect a resumption of typical trade wind flow and weather, with clouds and showers favoring windward and mauka areas.
Models show an area of deep moisture east of 150W will eventually pass across the islands, probably in the Wednesday to Thursday time frame. Expect renewed upper troughing west of the islands during the latter half of the week. As this forces ridging to amplify north of the islands, surface pressure rises over the northeast Pacific Basin will boost trade wind speeds across local waters. Stronger trades, combined with increased moisture coming in from the east, may trigger a brief period of wetter trades Wednesday and Thursday.

Aviation

Moderate trade winds will prevail throughout the next couple of days with high pressure north of the state. Therefore, expect scattered showers to occur along windward areas with isolated activity elsewhere as a drier trade wind pattern resumes across the island chain. Although MVFR ceilings and visibilities may occur at times from passing clouds and showers, VFR conditions are expected to prevail at most locations.
Latest satellite imagery and surface observations reveal that the extensive showers and clouds that were observed across windward sections of the Big Island overnight have diminished early this morning. As a result, AIRMET Sierra for tempo mountain obscuration has been cancelled. There are currently no AIRMETS in effect and none are anticipated today.

Marine

Expect moderate trade winds to continue through Monday across all Hawaiian waters. A high pressure system will build in from the north early next week producing moderate to locally strong trade winds from Tuesday onward where Small Craft Advisory thresholds may be reached for the typical windier waters around Maui and the Big Island.
Small medium period overlapping northwest and north swell energy will keep small surf going along north facing shores through Wednesday. A brief longer period northwest pulse of swell energy may arrive by Thursday providing a small bump in surf heights for north facing shores into Friday.
Background small medium period south swell energy will continue to keep fun size surf along south facing shores for most days this week. Downward south swell trends are in the long range forecast by the end of the week. Surf heights along west facing shores will remain small through the week with a bit of south swell wrap keeping west side surf heights above flat levels.
Surf along east facing shores will remain small through Monday. Strengthening trade winds on Tuesday will cause surf heights along east facing shores to rise through the middle of the week, as the high pressure ridge builds north of the region and the trade winds strengthen.

HFO Watches/Warnings/Advisories

None.

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Data Courtesy of NOAA.gov