West Side

Today: Sunny and breezy. Highs 74 to 79. East winds 10 to 25 mph.

Tonight: Partly cloudy. Breezy. Lows 63 to 70. East winds 10 to 20 mph.

Thursday: Breezy. Mostly sunny with isolated showers in the morning, then partly sunny in the afternoon. Highs 74 to 80. East winds 10 to 20 mph. Chance of rain 20 percent.

South Side

Today: Sunny and breezy. Highs around 81. East winds up to 15 mph increasing to up to 25 mph with gusts to 45 mph in the afternoon.

Tonight: Partly cloudy. Breezy. Lows 62 to 71. East winds 10 to 25 mph.

Thursday: Mostly sunny in the morning then becoming partly sunny. Breezy. Highs around 81. East winds 15 to 25 mph with gusts to 45 mph.

North Shore

Today: Windy. Partly sunny with scattered showers. Highs around 76 near the shore to around 59 near 5000 feet. East winds up to 30 mph with gusts to 50 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 66 near the shore to around 47 near 5000 feet. East winds 15 to 25 mph. Chance of rain 50 percent.

Thursday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs around 76 near the shore to around 59 near 5000 feet. East winds 10 to 25 mph. Chance of rain 70 percent.

Central Maui

Today: Sunny and breezy. Highs 76 to 82. East winds 10 to 25 mph with gusts to 45 mph.

Tonight: Partly cloudy. Breezy. Lows 63 to 68. East winds 15 to 20 mph.

Thursday: Mostly sunny. Breezy. Highs 76 to 82. East winds 15 to 25 mph.

Upcountry

Today: Mostly sunny in the morning then becoming partly sunny. Breezy. Scattered showers. Highs around 56 at the visitor center to around 66 at the summit. East winds 10 to 25 mph. Chance of rain 50 percent.

Tonight: Windy. Mostly cloudy with scattered showers. Lows 38 to 51. East winds 10 to 30 mph. Chance of rain 50 percent.

Thursday: Partly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 56 at the visitor center to around 61 at the summit. East winds 10 to 25 mph. Chance of rain 50 percent.

East Maui

Today: Windy. Partly sunny with scattered showers. Highs around 76 near the shore to around 59 near 5000 feet. East winds up to 30 mph with gusts to 50 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 66 near the shore to around 47 near 5000 feet. East winds 15 to 25 mph. Chance of rain 50 percent.

Thursday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs around 76 near the shore to around 59 near 5000 feet. East winds 10 to 25 mph. Chance of rain 70 percent.

Lanai City

Today: Mostly sunny. Breezy. Highs 69 to 76. Light winds becoming east up to 25 mph in the afternoon.

Tonight: Partly cloudy. Breezy. Lows around 61. East winds 15 to 20 mph.

Thursday: Partly sunny. Breezy. Highs 69 to 76. East winds 15 to 20 mph.

Kaunakakai

Today: Mostly sunny. Windy. Highs 64 to 81. East winds up to 30 mph increasing to 15 to 30 mph in the afternoon.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Breezy. Lows 54 to 69. East winds 10 to 25 mph.

Thursday: Partly sunny. Breezy. Highs 64 to 82. East winds 15 to 25 mph.

Detailed Forecast

Synopsis

A breezy to windy trade wind pattern will persist through at least Wednesday, then gradually wane through the rest of the week. Moisture embedded in the trades will allow showers to favor windward and mauka areas. An overall wetter pattern is possible this weekend as additional moisture is drawn over the island chain.

Discussion

A stationary 1037 mb surface high is centered north northeast of Hawaii this morning. A stationary front is located 600 miles northwest of Kauai. 12Z soundings showed a subsidence driven inversion with by strong dry advection in the mid-levels supported by high dewpoint depressions. Winds continue to blow strong across the state at advisory levels (sustained speeds of 30-39 mph and/or gusts 50-57 mph) across portions of islands, especially over higher terrain, passes, and areas immediately south through west of mountains. A Wind Advisory goes through 6pm HST today for these portions of the state. By Thursday, winds will begin to decrease, but remain locally strong throughout the rest of the work week.
As far as precipitation is concerned, little change is expected over the next few days, with occasional showers and clouds embedded within the trades favoring windward and mauka areas over the next several days. Things begin to get a bit more interesting near the end of the week, as an overall pattern shift could ultimately lead to several days of wet and unstable trade this weekend into early next week.
Latest guidance remains in good agreement that southeast flow in the lower levels could expand moisture over the islands late this week, then stall it over the state for at least Saturday and Sunday. While it is still very early, this will be closely monitored for potential flooding that could develop in this scenario. As the previous discussion pointed out, however, forecast confidence will largely depend on the expected strength of trades, which will in turn modulate forward motion of showers. The latest guidance continues to indicate that the islands could reside somewhere along the gradient between stronger trades to the east and light southeast flow to the west (though where exactly this sets up could make a large difference in rainfall potential for the islands). Still too early for specifics as there remains a lot of room for error, but something to continue monitoring throughout the rest of the week.

Aviation

Breezy to strong easterly trade winds are expected through the next few days as strong high pressure resides to the north and low pressure resides far to the west northwest. Winds will be gusty at as well. Mid level ridging will keep conditions stable, which could enhance the wind gusts, as well as keep showers from getting too heavy. Showers should effect mainly windward and mountain areas, and will likely be more widespread during the overnight hours. Conditions should stay mostly VFR with pockets of MVFR at night with any passing showers.
AIRMET Tango is in effect for tempo moderate turbulence below 7000 feet over leeward sides of the islands as a result of the gusty winds. This AIRMET will likely continue through tonight.

Marine

Strong high pressure will remain far northeast of the state during the next couple of days, as a slow moving front approaches from the west. The front will stall out and weaken into a trough just a few hundred miles west of the islands this weekend, with a new high building in to the distant north. A Gale Warning remains in effect for the Pailolo and Alenuihaha Channels as well as Maalaea Bay through 6 PM this evening, with a Small Craft Advisory (SCA) in effect for all other waters. The SCA will likely need to be extended through at least Thursday for all waters once the Gale Warning is taken down. The trade winds and seas are then expected to gradually lower Friday through the weekend.
Surf will hold relatively steady along east facing shores during the next couple of days, and as a result the High Surf Advisory (HSA) has been extended through 6 PM Thursday. As the trade winds ease late in the week and over the weekend, surf along east facing shores will gradually lower below HSA thresholds.
Surf along north and west facing shores will remain well below seasonal levels through the weekend, and surf along south facing shores will remain very small.
Forerunners from a large, long-period north to north-northeast swell are forecast to arrive Sunday night, then rapidly build to advisory and potentially warning levels along north facing shores late Monday through Tuesday.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 PM HST Thursday for east facing shores of Kauai, Oahu, Molokai, Maui, and the Big Island.
Wind Advisory until 6 PM HST this evening for Waianae Mountains, Lanai Mauka, Kahoolawe, Maui Windward West, Kohala, Big Island Interior, Koolau Leeward, Molokai Windward, Molokai Southeast, Molokai North, Molokai West, Lanai Windward, Lanai Leeward, Lanai South, Maui Central Valley North, Maui Central Valley South, Windward Haleakala, South Haleakala, Big Island South, Big Island Southeast, Big Island North.
Small Craft Advisory until 6 PM HST this evening for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Oahu Leeward Waters, Kaiwi Channel, Maui County Windward Waters, Maui County Leeward Waters, Big Island Windward Waters, Big Island Leeward Waters, Big Island Southeast Waters.
Gale Warning until 6 PM HST this evening for Maalaea Bay, Pailolo Channel, Alenuihaha Channel.

Data Courtesy of NOAA.gov