West Side

Today: Sunny and windy. Highs 79 to 86. Northeast winds 20 to 30 mph.

Tonight: Mostly clear. Windy. Isolated showers after midnight. Lows 68 to 77. Northeast winds 10 to 30 mph. Chance of rain 20 percent.

Wednesday: Sunny and breezy. Highs 80 to 86. Northeast winds 10 to 20 mph.

South Side

Today: Sunny and breezy. Highs around 88. Northeast winds up to 25 mph.

Tonight: Mostly clear. Breezy. Lows 69 to 77. Northeast winds 10 to 25 mph.

Wednesday: Sunny and breezy. Highs around 88. Northeast winds 10 to 20 mph. Gusts up to 40 mph in the afternoon.

North Shore

Today: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs around 82 near the shore to around 64 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows around 72 near the shore to around 52 near 5000 feet. East winds 10 to 25 mph. Chance of rain 40 percent.

Wednesday: Mostly sunny with scattered showers. Highs around 82 near the shore to around 65 near 5000 feet. East winds 10 to 15 mph. Chance of rain 40 percent.

Central Maui

Today: Sunny and breezy. Isolated showers in the morning. Highs 80 to 88. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Isolated showers after midnight. Lows 69 to 76. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Wednesday: Sunny and breezy. Highs 80 to 88. East winds 10 to 25 mph.

Upcountry

Today: Sunny and breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 61 at the visitor center to around 69 at the summit. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows around 49 at the visitor center to around 45 at the summit. East winds 10 to 25 mph. Chance of rain 20 percent.

Wednesday: Breezy. Mostly sunny with isolated showers. Highs around 62 at the visitor center to around 59 at the summit. East winds 10 to 25 mph. Chance of rain 20 percent.

East Maui

Today: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs around 82 near the shore to around 64 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows around 72 near the shore to around 52 near 5000 feet. East winds 10 to 25 mph. Chance of rain 40 percent.

Wednesday: Mostly sunny with scattered showers. Highs around 82 near the shore to around 65 near 5000 feet. East winds 10 to 15 mph. Chance of rain 40 percent.

Lanai City

Today: Sunny and breezy. Highs 73 to 82. Northeast winds 10 to 25 mph.

Tonight: Mostly clear. Breezy. Lows 66 to 71. Northeast winds 10 to 25 mph.

Wednesday: Sunny and breezy. Highs 73 to 82. Northeast winds 10 to 20 mph.

Kaunakakai

Today: Sunny and windy. Highs 69 to 88. East winds up to 30 mph shifting to the northeast 10 to 25 mph in the afternoon.

Tonight: Mostly clear. Breezy. Isolated showers after midnight. Lows 60 to 76. Northeast winds up to 25 mph with gusts to 45 mph. Chance of rain 20 percent.

Wednesday: Sunny and breezy. Highs 70 to 88. East winds 10 to 25 mph with gusts to 45 mph.

Detailed Forecast

Synopsis

The tight pressure gradient draped across the islands, driven by an area of strong high pressure far north of the state, will continue to produce breezy to windy trades for the remainder of the week. Showers will primarily focus along windward exposures as well as along upslope higher terrain. An increase in shower coverage and frequency is anticipated later this week, with higher rain accumulations likely occurring during the nocturnal hours.

Discussion

Trade winds will remain stout across many island communities the next several days. The windiest spots will be over momentum- building areas downslope of higher terrain or in the lee of Big Island volcanoes such as Mauna Kea through the Hamakua and Kona regions, the southeastern West Maui range close to the northwest Maalaea Bay coast, exposed Kalaupapa in north Molokai, as well as leeward locales just downslope of higher terrain on Oahu and windward Kauai. Winds over these areas or those similar in wind exposure and downwind of higher terrain, have remained 25 mph sustained gusting to near 40 mph. More frequent light to occasionally moderate intensity showers will occur across many windward locations with more organized pockets of rain briefly spilling over into neighboring leeward communities. The short term rainfall forecast has the highest QPF centered on the windward upslope upper terrain of both Maui and Big Island through early Wednesday morning.
The Central Pacific upper air pattern remains stagnant as the state falls under the influence of a weak col between two relatively weak closed off lows. This synoptic setup of the islands trapped between these two weak upper lows with an anchored surface high far north of the island chain translates to little to no change for the remainder of the week. Thus, trades will remain amped up with typical trade shower behavior. Model guidance is in good phase alignment with these near-statiaonry features along with a bout of enhanced mid layer moisture advection, possibly in association with a weak tropical wave, that will begin arriving Thursday and passing over the state through Saturday. Higher-than-normal precipitable waters moving in from the east later this week signals a more wet pattern change. Rain coverage and higher intensity showers entrained within robust trades will result in higher statewide rain accumulations from Thursday into the weekend. The trade inversion will weaken, deepening a more moist boundary layer upwards to a depth of 10k ft or slightly higher. Dew points treading in the lower 70s will be felt in increased late week surface humidity. The good news is that more muggy conditions will be a bit offset by enhanced trades.

Aviation

Moderate to breezy trades will continue today and bring low clouds and scattered showers to mainly windward and mountain areas. There may also be isolated spillover into leeward sites. VFR will prevail for most sites, with occasional localized MVFR mainly for windward/mountain sites for the shower activity.
AIRMET Tango remains in effect for moderate low level turbulence over and downwind of terrain for all islands. This AIRMET will likely continue through the next several days.

Marine

A strong high pressure ridge centered north of the state will help to drive fresh to strong trades across all local waters through this afternoon. A Small Craft Advisory (SCA) remains in effect for all waters through this afternoon. Will continue to monitor to see if some zones may drop out of the SCA as winds shift more easterly and drop a notch this evening.
A moderate, long period, south southwest (190-200 degrees) swell will continue to generate surf along south facing shores just below advisory levels. This swell energy will slowly lower today through the remainder of the week. Expect small surf for south facing shores leading into this weekend with mainly background energy. Another moderate, long period south southwest swell (210-220 degrees) may fill in Sunday but due to the direction of the source could be more inconsistent than this current swell.
Surf along east facing shores will remain rough and choppy through the week as fresh to strong trades hold. A small, moderate period west (280 degrees) swell is expected to arrive this weekend and linger into early next weekend. No significant swells are expected out of the north or northwest.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST this evening for Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters, Big Island Windward Waters, Kaiwi Channel, Kauai Channel, Kauai Leeward Waters, Kauai Northwest Waters, Kauai Windward Waters, Maalaea Bay, Maui County Leeward Waters, Maui County Windward Waters, Oahu Leeward Waters, Oahu Windward Waters, Pailolo Channel.

Data Courtesy of NOAA.gov