Hilo

Today: Scattered showers. Partly sunny, with a high near 83. West wind 5 to 8 mph becoming east northeast in the morning. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely, mainly after midnight. Mostly cloudy, with a low around 68. West wind around 5 mph becoming calm after midnight. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Showers likely, mainly before noon. Partly sunny, with a high near 82. Calm wind becoming east 5 to 8 mph in the afternoon. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Kona

Today: Scattered showers after noon. Partly sunny, with a high near 85. East wind 5 to 9 mph becoming west in the morning. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers, mainly before midnight. Mostly cloudy, with a low around 70. East wind around 6 mph becoming calm in the evening. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Scattered showers after noon. Partly sunny, with a high near 84. Calm wind becoming northeast around 5 mph in the afternoon. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Waimea

Today: Scattered showers, mainly after noon. Mostly sunny, with a high near 77. Windy, with a northeast wind 22 to 29 mph, with gusts as high as 41 mph. Chance of precipitation is 30%. New precipitation amounts between a tenth and quarter of an inch possible.

Tonight: Scattered showers, mainly before midnight. Mostly cloudy, with a low around 58. Windy, with an east wind around 23 mph, with gusts as high as 32 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Scattered showers. Partly sunny, with a high near 77. Breezy, with an east northeast wind 14 to 22 mph, with gusts as high as 31 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Kohala

Today: Scattered showers. Partly sunny, with a high near 69. Windy, with an east wind 25 to 30 mph, with gusts as high as 44 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 51. Windy, with an east wind around 26 mph, with gusts as high as 38 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Showers likely, mainly before noon. Partly sunny, with a high near 69. Windy, with an east wind 17 to 26 mph, with gusts as high as 38 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

South Big Island

Today: Isolated showers. Mostly sunny, with a high near 80. Very windy, with an east wind 28 to 32 mph, with gusts as high as 36 mph. Chance of precipitation is 20%.

Tonight: Isolated showers. Partly cloudy, with a low around 69. Very windy, with an east northeast wind 29 to 32 mph. Chance of precipitation is 20%.

Thursday: Isolated showers. Mostly sunny, with a high near 81. Windy, with an east wind 22 to 29 mph, with gusts as high as 32 mph. Chance of precipitation is 20%.

Puna

Today: Scattered showers. Partly sunny, with a high near 78. Northeast wind around 14 mph, with gusts as high as 18 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely, mainly after midnight. Mostly cloudy, with a low around 64. Northeast wind 9 to 13 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

Thursday: Showers likely, mainly before noon. Partly sunny, with a high near 78. Northeast wind 9 to 14 mph, with gusts as high as 18 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

Waikoloa

Today: Mostly sunny, with a high near 84. Windy, with a northeast wind 17 to 22 mph increasing to 25 to 30 mph. Winds could gust as high as 44 mph.

Tonight: Mostly clear, with a low around 68. Breezy, with an east southeast wind 16 to 18 mph, with gusts as high as 25 mph.

Thursday: Isolated showers after noon. Mostly sunny, with a high near 84. Breezy, with an east southeast wind 8 to 16 mph becoming west northwest in the morning. Winds could gust as high as 22 mph. Chance of precipitation is 20%.

Detailed Forecast

Synopsis

Trade winds will persist into the first half of next week as a surface high remains north of the islands. The moderate to strong trades though will ease off a notch or two over the weekend as a weakening front approaches the islands from the north. The remnants of this front may bring an uptick in trade showers early next week to the northern islands. These trade showers will favor the windward and mountain areas, while the lee side of especially the smaller islands continue dry.

Discussion

A 1030 mb surface high is located a thousand miles north of the islands this early Wednesday morning. This high will drift west then north through the rest of the week. With the high being further away from the islands, the moderate to strong trades will trend lighter to moderate speed between Thursday and Friday night. Another reason for the lighter trades over the weekend is a front will be approaching the islands from the north. This front is associated with a surface low forecast to set up shop right off the Pacific Northwest and Vancouver B.C.. The front is forecast to fall apart while approaching the islands. The remnants will bring a boost in trade showers to Kauai about Monday night and Tuesday, and Oahu around Tuesday and Wednesday. There are no significant mid or upper level features to enhance these trade showers.
The latest satellite imagery shows the leading edge to a large field of mainly stable stratocumulus clouds about to reach windward Maui and windward Big Island, with Molokai and Oahu more toward sunrise. The daytime heating and wind will help to disperse a good bit of these clouds as the day progresses. Thus, Kauai is likely get the most sun today. Weather radar is showing widely dispersed light showers so far, and even less showers with the leading edge to the field of stratocumulus clouds.

Aviation

A large high pressure ridge north of the islands will keep moderate to breezy trade winds in the forecast through at least Thursday. These stronger trade winds will produce clouds and brief passing showers over windward and mountain sections of each island. Less clouds and showers will develop over more stable leeward airfields. Cloud and shower trends will increase in the overnight to early morning hours. Brief periods of MVFR conditions in showers are possible along these favored windward slopes.
AIRMET Tango remains in effect for Moderate Turbulence over and SW through NW of island mountains due to strong winds flowing over higher terrain features. This AIRMET will likely continue through Thursday.

Marine

Fresh to strong easterly trade winds will continue through Thursday as high pressure to the north inches southward and the gradient remains tight over the region. Guidance continues to suggest a weakness in the ridge forming to the northeast Friday into the weekend as a front dips southward over the northeast Pacific. Easterly trades will respond and ease into the moderate to fresh category, potentially enough to relax the Small Craft Advisory for all areas by Saturday.
Surf along east facing shores will remain rough through Thursday due to the strong trades in place. Thereafter, a downward trend appears possible due to the upstream trades being disrupted from the aforementioned front dipping southward over the northeast Pacific.
Surf along north facing shores will remain near flat levels through the remainder of the week, with the exception being along the typical areas exposed to trade wind energy wrapping in. There is a chance for a small, low/medium-period, north-northeast swell early next week due to broad low pressure setting up over the Gulf of Alaska this weekend.
Surf along south facing shores will remain small through the rest of the week with mainly background southerly swells rolling through.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov