Hilo

Rest Of Today: Mostly cloudy. Occasional showers in the morning, then numerous showers in the afternoon. Highs 76 to 87 near the shore to around 69 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 90 percent.

Tonight: Mostly cloudy. Numerous showers in the evening, then scattered showers after midnight. Lows 65 to 71 near the shore to around 58 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 70 percent.

Wednesday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 76 to 87 near the shore to around 69 at 4000 feet. North winds up to 15 mph shifting to the northeast in the afternoon. Chance of rain 50 percent.

Kona

Rest Of Today: Partly sunny. Scattered showers in the morning, then numerous showers in the afternoon. Highs 82 to 88 near the shore to around 69 near 5000 feet. Southwest winds up to 10 mph shifting to the west in the afternoon. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 74 near the shore to 51 to 56 near 5000 feet. Light winds. Chance of rain 50 percent.

Wednesday: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 81 to 88 near the shore to around 68 near 5000 feet. Northwest winds up to 10 mph. Chance of rain 40 percent.

Waimea

Rest Of Today: Breezy. Mostly cloudy with scattered showers. Highs 72 to 81 near the shore to 67 to 80 near 3000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 64 to 71 near the shore to around 61 near 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Wednesday: Mostly sunny with scattered showers in the morning, then partly sunny with isolated showers in the afternoon. Highs 72 to 81 near the shore to 66 to 79 near 3000 feet. East winds 10 to 15 mph. Chance of rain 40 percent.

Kohala

Rest Of Today: Breezy. Mostly cloudy with scattered showers. Highs 72 to 81 near the shore to 67 to 80 near 3000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 64 to 71 near the shore to around 61 near 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Wednesday: Mostly sunny with scattered showers in the morning, then partly sunny with isolated showers in the afternoon. Highs 72 to 81 near the shore to 66 to 79 near 3000 feet. East winds 10 to 15 mph. Chance of rain 40 percent.

South Big Island

Rest Of Today: Partly sunny. Breezy. Scattered showers in the morning, then numerous showers in the afternoon. Highs around 86 near the shore to around 67 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 73 near the shore to around 52 near 5000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Wednesday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 86 near the shore to around 66 near 5000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 40 percent.

Puna

Rest Of Today: Mostly cloudy. Occasional showers in the morning, then numerous showers in the afternoon. Highs 76 to 87 near the shore to around 69 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 90 percent.

Tonight: Mostly cloudy. Numerous showers in the evening, then scattered showers after midnight. Lows 65 to 71 near the shore to around 58 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 70 percent.

Wednesday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 76 to 87 near the shore to around 69 at 4000 feet. North winds up to 15 mph shifting to the northeast in the afternoon. Chance of rain 50 percent.

Waikoloa

Rest Of Today: Mostly sunny in the morning then becoming partly sunny. Scattered showers in the afternoon. Highs 84 to 89 near the shore to 66 to 73 above 4000 feet. North winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Tonight: Partly cloudy. Lows around 75 near the shore to 53 to 58 above 4000 feet. Southeast winds up to 15 mph.

Wednesday: Mostly sunny. Highs around 86 near the shore to 65 to 73 above 4000 feet. Northeast winds up to 15 mph.

Detailed Forecast

Synopsis

High pressure will meander northwest of the islands and weaken over the next several days. Winds will weaken later today then further weaken during the second half of the week. Stable conditions prevail with any rainfall remaining light.

Discussion

This morning sounding show inversions heights have increased about 1 kft overnight and is now around 7 to 8 kft as a slightly above average moisture field works its way through the island chain. High clouds are streaming over the state as low level clouds move of east to west focusing clouds and showers along windward and mauka areas. Overnight rainfall totals range from .01 to .78 inches for the rainier areas of Kauai. CIMSS satellite observations and model guidance shows drier air filling in behind this moisture field and inversion heights sinking to around 4-6 kft this afternoon. The lower inversion heights and available moisture should further limit showers to windward and mauka areas, leaving most leeward locations fairly dry and showers light. The exception would be the kona slopes of the Big Island where afternoon sea breezes can generate isolated showers. This pattern is expected to persist through the week with minor fluctuations in inversion heights and showers due to diurnal patterns and bands of moisture moving through.
A low developing far northeast of the islands will generate a weakness in the the local pressure gradient going forward. Trades will trend downward accordingly, falling into the moderate range later today and potentially becoming light with a corresponding increase in apparent temperature during the second half of the week.

Aviation

Breezy trade winds will hold in place today, with a slight easing expected tonight. Trade wind showers will continue to bring MVFR cigs/vsbys into windward areas at times through the early morning hours, with improving conditions expected by this afternoon.
AIRMET Sierra is now in effect for mountain obscuration across windward sections of Kauai Oahu Molokai and Maui. This AIRMET will likely need to be expanded to include windward Big Island later this morning.
AIRMET Tango remains in effect for moderate low level turbulence over and downwind of the terrain of all islands. This AIRMET will likely remain in place today.

Marine

A high pressure system northwest of the islands continues to drift west. The ridge axis north of the state will weaken and move south as a low pressure system sets up far northeast of the island chain. Trade winds will continue weakening through Friday. A Small Craft Advisory (SCA) remains in effect through the afternoon hours for the typical windy areas around Maui County and the Big Island. The SCA may be cancelled by tonight as wind speeds continue to trend lower.
Small background energy from the south-southwest swells (200 degrees) will continue along south facing shores throughout the first half of this week. A compact storm force low tracked easterly along 25S to 30S between 170W and 150W over the past several days. This storm should produce a moderate south swell, which should fill in on Thursday, peak Friday and slowly decline over the weekend. Surf will likely be near or above the summer average (5 ft) Thursday through the weekend for south facing shores.
Surf along east facing shores will remain rough and choppy and slowly ease over the next few days as the trade winds ease. Tiny background swell energy from the west-northwest is possible later today into Wednesday due to a Typhoon tracking near Taiwan last week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST this evening for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

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Data Courtesy of NOAA.gov