Photo Credit: Tyler Rooke

West Side

Today: Scattered showers, mainly before 1pm. Mostly sunny, with a high near 83. Northeast wind 5 to 7 mph becoming southeast in the afternoon. Chance of precipitation is 30%.

Tonight: Isolated showers before 1am. Partly cloudy, with a low around 66. Breezy, with an east northeast wind 8 to 13 mph increasing to 16 to 21 mph in the evening. Winds could gust as high as 29 mph. Chance of precipitation is 20%.

Sunday: Sunny, with a high near 84. Breezy, with an east northeast wind 13 to 18 mph becoming light and variable in the afternoon. Winds could gust as high as 25 mph.

South Side

Today: Mostly sunny, with a high near 83. Light and variable wind becoming west southwest around 6 mph.

Tonight: Mostly clear, with a low around 64. Light and variable wind becoming northeast around 6 mph after midnight.

Sunday: Isolated showers after noon. Mostly sunny, with a high near 84. Light and variable wind becoming east 6 to 11 mph in the afternoon. Chance of precipitation is 20%.

North Shore

Today: Scattered showers. Partly sunny, with a high near 81. Breezy, with an east wind 11 to 18 mph, with gusts as high as 25 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers before 1am. Mostly cloudy, with a low around 65. Breezy, with an east wind 14 to 21 mph, with gusts as high as 29 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Sunday: Isolated showers after 1pm. Mostly sunny, with a high near 82. Breezy, with an east wind 16 to 20 mph, with gusts as high as 28 mph. Chance of precipitation is 20%.

Central Maui

Today: Scattered showers. Partly sunny, with a high near 81. Breezy, with a northeast wind 9 to 15 mph, with gusts as high as 21 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers, mainly before 1am. Partly cloudy, with a low around 63. Breezy, with a northeast wind 8 to 15 mph, with gusts as high as 21 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Sunday: Isolated showers before 7am. Mostly sunny, with a high near 82. East northeast wind 11 to 13 mph. Chance of precipitation is 20%.

Upcountry

Today: Isolated showers after 1pm. Mostly sunny, with a high near 69. Calm wind becoming west 5 to 7 mph in the afternoon. Chance of precipitation is 20%.

Tonight: Isolated showers before 7pm. Partly cloudy, with a low around 53. West wind 5 to 8 mph becoming southeast in the evening. Chance of precipitation is 20%.

Sunday: Mostly sunny, with a high near 69. Southeast wind around 5 mph becoming light and variable.

East Maui

Today: Showers likely, mainly after 1pm. Mostly cloudy, with a high near 79. East wind 6 to 10 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely, mainly before 7pm. Mostly cloudy, with a low around 61. Breezy, with an east wind 10 to 16 mph, with gusts as high as 22 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Sunday: Scattered showers. Partly sunny, with a high near 80. East southeast wind 9 to 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.

Lanai City

Today: Scattered showers. Partly sunny, with a high near 75. East northeast wind 10 to 13 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Isolated showers before midnight. Partly cloudy, with a low around 62. North northeast wind 6 to 13 mph. Chance of precipitation is 20%.

Sunday: Mostly sunny, with a high near 76. East northeast wind 5 to 9 mph becoming northwest in the afternoon.

Kaunakakai

Today: Scattered showers. Partly sunny, with a high near 80. Breezy, with an east wind 6 to 15 mph, with gusts as high as 21 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers before midnight. Partly cloudy, with a low around 71. East wind 11 to 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.

Sunday: Sunny, with a high near 81. Breezy, with an east wind 11 to 20 mph, with gusts as high as 28 mph.

Detailed Forecast

Synopsis

High pressure passing by far to the north of the state will keep breezy trade winds in place through the remainder of the holiday weekend. Moisture associated with a dissipating front will bring periods of showery weather to windward sections of the smaller islands today, along with some leeward spillover, while drier conditions persist over the Big Island. Drier conditions are expected statewide Sunday through Wednesday, with a few showers possible in windward areas and locations near the coast during nights and early mornings, and over interior and leeward areas during the afternoon hours. The trades will ease and shift around to the east-southeast Sunday night through the middle of next week, with some VOG possibly lifting northward into the smaller islands, most likely Tuesday and Wednesday. Trade winds should return Thursday and become breezy on New Years Day.

Discussion

Currently at the surface, a band of low clouds and showers associated with an old front continues to affect the smaller islands this morning. Meanwhile, a 1032 mb high remains centered around 800 miles north of Honolulu, driving moderate trade winds across the island chain early this morning. Infrared satellite imagery shows partly to mostly cloudy skies across the smaller islands, and clear to partly cloudy conditions over the Big Island. Radar imagery shows scattered to numerous showers moving into windward sections of the smaller islands, with some of the decaying showers spreading into leeward areas. Across windward Big Island, isolated to widely scattered showers are moving onshore, with rain free conditions in leeward locales. Main short term concerns continue to revolve around trade wind trends and rain chances through the remainder of the Holiday weekend.
Strong high pressure will slide slowly eastward well to the north of the state during the next couple days, keeping breezy trade winds in place across the island chain. In fact, it could get rather windy in some downslope areas tonight into early Sunday, as conditions stabilize following the passage of an upper level trough. We will need to keep an eye on this, as there is the potential that some of the more typically windy areas could flirt with Wind Advisory levels. The trades will then ease from west to east across the island chain Sunday night through the first half of next week, as a cold front approaches from the northwest. The trades will diminish the most over the western islands during this time, where daytime sea breezes and overnight land breezes will be likely Monday through Wednesday. Over the eastern islands, the gradient will likely remain tight enough to allow moderate east- southeasterly winds to hang on. Under this particular flow regime, the re-emergence of volcanic activity on the Big Island, may send some VOG northward into the smaller islands at times, mostly likely Tuesday and Wednesday. High pressure building to the north of the islands could bring a return of moderate trade winds and scour out any lingering VOG over the smaller islands on Thursday, with the trades becoming breezy for New Years Day.
As for the remaining weather details, the moisture associated with the old front is expected to hang up over the smaller islands today, and this will likely result in periods of showery weather persisting over windward areas along with some leeward spillover. Drier conditions will likely persist over the Big Island. The moisture associated with the frontal remnants is forecast to break apart rather quickly tonight, so expect a decrease in shower coverage, although a few passing showers will likely continue to affect windward locales. Drier conditions are expected statewide Sunday through Wednesday. A few passing showers will remain possible during the nights and early mornings in windward areas and locations near the coast, with a shower or two possible over interior and leeward areas each afternoon. A return to a more typical windward/mauka shower pattern should take hold Thursday through New Years Day.

Aviation

The remnants of an old front will spread clouds and periods of showers across the smaller islands today. A weak disturbance will may move into the eastern Big Island this evening increasing clouds and shower trends from Kau northward to Hilo and along the Hamakua Coast.
Trade winds are increasing in strength as high pressure builds north of the region. Stronger winds will produce tempo moderate low level turbulence over and south through west of mountain ranges. A passing upper level disturbance will also produce tempo moderate turbulence aloft between FL250-350 through the early morning hours.
AIRMET Sierra in effect for Tempo Mountain Obscurations for Kauai, Oahu and Molokai over north through east sections. This AIRMET will likely continue through the afternoon hours.
AIRMET Tango in effect for Tempo Moderate Turbulence below 8000 feet over and south through west of mountain ranges. Another AIRMET Tango remains in effect for Tempo Moderate Turbulence between FL250-350 for a passing upper level disturbance.

Marine

A strengthening high pressure system passing eastward far north of the state will produce increasing trade winds. A scatterometer pass showed widespread 25 kt winds around Kauai which was consistent with the high resolution model guidance. The model data also showed 25 kt winds in the leeward waters of Oahu, Maui, and the Big Island today and tonight. As a result, the Small Craft Advisory (SCA) has been expanded to cover these leeward waters, and also extended in time through late tonight.
The current northwest swell continues to trend downward. A small, sub-advisory northwest swell is expected late Sunday. This will be followed by a more significant, advisory-level northwest swell Monday night. A larger northwest swell is forecast to arrive on Tuesday and peak on Tuesday night or early Wednesday. Surf from this larger swell should produce warning level surf.
The increasing trade winds will produce choppy surf along the east-facing shores through the weekend. This surf may reach advisory levels by this evening and early Sunday before subsiding through the middle of next week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Sunday for all Hawaiian waters,

Data Courtesy of NOAA.gov