Photo Credit: James Grenz

Hilo

Today: Cloudy. Showers likely in the morning, then scattered showers in the afternoon. Highs 78 to 84 near the shore to 64 to 70 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with showers likely. Lows 63 to 71 near the shore to around 56 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 70 percent.

Monday: Mostly cloudy. Showers likely in the morning, then scattered showers in the afternoon. Highs 78 to 84 near the shore to 64 to 70 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Kona

Today: Mostly sunny with isolated showers in the morning, then mostly cloudy with scattered showers in the afternoon. Haze through the day. Highs 83 to 88 near the shore to around 68 near 5000 feet. Southwest winds up to 10 mph. Chance of rain 40 percent.

Tonight: Partly cloudy with isolated showers. Haze. Lows 70 to 75 near the shore to 51 to 57 near 5000 feet. Light winds. Chance of rain 20 percent.

Monday: Mostly sunny with isolated showers in the morning, then mostly cloudy with scattered showers in the afternoon. Haze through the day. Highs 83 to 88 near the shore to around 67 near 5000 feet. South winds up to 10 mph shifting to the west in the afternoon. Chance of rain 40 percent.

Waimea

Today: Breezy. Mostly cloudy with scattered showers. Highs 65 to 85. East winds 10 to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 63 to 70 near the shore to 55 to 63 near 3000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Monday: Breezy. Partly sunny with scattered showers. Highs 64 to 84. East winds 10 to 20 mph decreasing to up to 20 mph in the afternoon. Chance of rain 50 percent.

Kohala

Today: Breezy. Mostly cloudy with scattered showers. Highs 65 to 85. East winds 10 to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 63 to 70 near the shore to 55 to 63 near 3000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Monday: Breezy. Partly sunny with scattered showers. Highs 64 to 84. East winds 10 to 20 mph decreasing to up to 20 mph in the afternoon. Chance of rain 50 percent.

South Big Island

Today: Breezy. Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Haze through the day. Highs around 84 near the shore to around 67 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Haze through the night. Lows around 72 near the shore to around 54 near 5000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

Monday: Breezy. Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Haze through the day. Highs around 84 near the shore to around 66 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Puna

Today: Cloudy. Showers likely in the morning, then scattered showers in the afternoon. Highs 78 to 84 near the shore to 64 to 70 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with showers likely. Lows 63 to 71 near the shore to around 56 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 70 percent.

Monday: Mostly cloudy. Showers likely in the morning, then scattered showers in the afternoon. Highs 78 to 84 near the shore to 64 to 70 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Waikoloa

Today: Breezy. Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs 83 to 89 near the shore to 67 to 73 above 4000 feet. Northeast winds up to 25 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Isolated showers in the evening. Lows around 73 near the shore to 50 to 56 above 4000 feet. Southeast winds up to 20 mph. Chance of rain 20 percent.

Monday: Breezy. Sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs 83 to 88 near the shore to 66 to 72 above 4000 feet. Northeast winds up to 20 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Moderate to breezy trade winds will continue through the first half of the week, with clouds and showers favoring windward and mauka locations. An upper disturbance over the region combined with an area of higher moisture will support better windward shower coverage over the next few days, especially overnight through the morning periods. Trade winds are expected to strengthen from Wednesday through the end of the week.

Discussion

Guidance remains in decent agreement and depicts more of a wet trade wind pattern holding into the start of the week over portions of the state due to a combination of an upper trough extending southward into the area and a decent sized area of higher moisture moving through. Although thunderstorms associated with the upper feature should remain well north of the islands, a few locally heavy showers over windward areas are possible. The best chance for this enhanced activity will favor the western end of the state, which is supported in recent upper air soundings between the Lihue and Hilo (more instability/lack of an inversion over Lihue) and satellite-derived precipitable water data. This setup will allow some showers to spill over into our dry leeward areas, especially overnight through the morning periods on Kauai and Oahu. Models and ensembles project a tightening pressure gradient by or around midweek, that supports locally strong trades Wednesday through the second half of the week.
VOG associated with the recent volcanic activity on the Big Island should remain confined to Kau and Kona Districts, given the trade wind flow that is expected through the week. This is evident on satellite imagery and has been reported locally. As a result, haze has been introduced to the forecast for these impacted areas.

Aviation

Surface high pressure centered far northeast of Hawaii will maintain moderate to occasionally breezy trades across the islands today. Slight instability in the vicinity of the western islands may cause an increase in low clouds and showers over windward sections of Oahu and Kauai. This may result in periods of MVFR ceilings and visibilities over portions of these islands. Elsewhere, expect a more typical trade wind distribution of low clouds and showers over windward sections. This may cause brief periods of MVFR conditions over parts of windward Molokai, Maui and the Big Island.
AIRMET Sierra has recently been issued for mountain obscuration above 2500 ft on Oahu. This AIRMET may need to be extended beyond daybreak if clouds and showers persist. This AIRMET may also be needed for Kauai later this morning if conditions deteriorate.

Marine

A high pressure ridge north of the Hawaiian Islands will continue to produce moderate to fresh trade winds over the coastal and offshore waters into Tuesday. Trade winds may strengthen from Wednesday onward as a stronger high builds in north of the region.
Small north to northwest swells will keep some small surf in place along north facing shores through the rest of the weekend. A small, long-period west-northwest swell, generated by Typhoon Mindulle, will boost surf along north and west facing shores of Kauai by Monday afternoon and then spreading into Oahu and Maui County from Tuesday through Thursday. North shore surf will diminish to smaller heights by Friday.
Small south and southeast swells will keep surf from going flat along south facing shores through the weekend and much of next week. A slightly larger south swell may elevate surf heights along south facing shores from Friday into next weekend.
East shore surf will hold fairly steady through Tuesday. Strengthening trades over and upstream of the islands will build surf heights along east facing shores from Thursday into next weekend.

HFO Watches/Warnings/Advisories

None.

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Data Courtesy of NOAA.gov