West Side

Today: Mostly sunny. Breezy. Isolated showers in the morning. Highs 79 to 90. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Breezy. Lows 68 to 77. Northeast winds 10 to 20 mph.

Friday: Mostly sunny. Breezy. Highs 79 to 90. Northeast winds 10 to 20 mph.

South Side

Today: Sunny and breezy. Highs 80 to 92. Northeast winds up to 20 mph.

Tonight: Partly cloudy. Breezy. Lows 70 to 75. Northeast winds up to 20 mph becoming 10 to 15 mph after midnight.

Friday: Mostly sunny. Breezy. Highs 80 to 92. Northeast winds 10 to 25 mph.

North Shore

Today: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs around 84 near the shore to around 69 near 5000 feet. East winds 10 to 20 mph decreasing to up to 20 mph in the afternoon. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 74 near the shore to around 56 near 5000 feet. Southeast winds up to 20 mph. Chance of rain 50 percent.

Friday: Mostly sunny in the morning then becoming partly sunny. Breezy. Scattered showers. Highs 82 to 87 near the shore to around 69 near 5000 feet. East winds up to 20 mph. Chance of rain 40 percent.

Central Maui

Today: Mostly sunny. Breezy. Highs 84 to 91. East winds 10 to 25 mph.

Tonight: Partly cloudy. Breezy. Lows around 72. Northeast winds 10 to 20 mph.

Friday: Mostly sunny. Breezy. Highs 83 to 91. Northeast winds 10 to 20 mph.

Upcountry

Today: Mostly sunny. Breezy. Scattered showers in the morning. Highs 57 to 73. East winds up to 25 mph. Chance of rain 50 percent.

Tonight: Windy. Mostly cloudy with isolated showers in the evening, then partly cloudy with scattered showers after midnight. Lows 45 to 56. East winds up to 30 mph. Chance of rain 50 percent.

Friday: Mostly sunny. Windy. Isolated showers in the afternoon. Highs around 64 at the visitor center to around 66 at the summit. East winds up to 30 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 84 near the shore to around 69 near 5000 feet. East winds 10 to 20 mph decreasing to up to 20 mph in the afternoon. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 74 near the shore to around 56 near 5000 feet. Southeast winds up to 20 mph. Chance of rain 50 percent.

Friday: Mostly sunny in the morning then becoming partly sunny. Breezy. Scattered showers. Highs 82 to 87 near the shore to around 69 near 5000 feet. East winds up to 20 mph. Chance of rain 40 percent.

Lanai City

Today: Sunny and breezy. Highs 73 to 83. Northeast winds up to 15 mph increasing to 10 to 20 mph in the afternoon.

Tonight: Partly cloudy. Breezy. Lows 62 to 69. Northeast winds 10 to 20 mph.

Friday: Mostly sunny. Breezy. Highs 73 to 83. Northeast winds 10 to 25 mph.

Kaunakakai

Today: Sunny and breezy. Highs 73 to 91. East winds 10 to 25 mph.

Tonight: Partly cloudy. Breezy. Lows 60 to 76. Northeast winds 10 to 20 mph.

Friday: Mostly sunny. Breezy. Highs 74 to 91. Northeast winds 15 to 20 mph.

Detailed Forecast

Synopsis

Moderate to breezy trade winds remains in the forecast for the foreseeable future. Brief passing showers are expected through Friday, mainly over windward and mountain areas in the overnight to early morning hours. The unstable cloud remnants of an old frontal band will drift through the islands from Friday night into Saturday, boosting cloud and rain shower coverage for all islands. These enhanced clouds and showers will linger over the windward slopes of the Big Island through Sunday, while other islands will return to a more typical brief passing shower pattern. By next week Tuesday, a weak upper level low drifts over the Hawaii Region, enhancing clouds and showers once again with the potential for wet weather trends.

Discussion

The satellite imagery this morning shows a subtropical jet stream over the Big Island with high clouds over the eastern edge of the state. Brief showers continue to drift over windward and mountain areas on local radar.
Weather conditions trend towards the wet side from Friday night into Saturday as an unstable cloud band, associated with the remnants of an old East Pacific cold front, will drift through the islands on the trade winds. Low level forcing and instability along this cloud band will boost trade wind showers statewide, favoring windward and mountain areas. The strongest shower bands will likely bring some much needed rainfall to favored leeward areas. A portion of this unstable cloud band will linger through Sunday along the windward slopes of the Big Island. As more stable conditions will return to the rest of the state.
Back to more typical brief passing showers in a moderate to breezy trade wind pattern through Monday. A weak upper level low drifts over the Hawaii Region by next week Tuesday, briefly boosting shower activity across the state through early Wednesday morning. We increased precipitation chances to account for this cold core unstable upper low over the islands during this time period.

Aviation

Moderate to breezy trade winds will continue for the next several days. Although some clouds and showers embedded within the trades will be possible for windward and mountain areas, VFR flight conditions are expected to prevail for most locations.
AIRMET Tango remains in effect for moderate low level turbulence over and downwind of island terrain. This AIRMET will likely be needed for the next several days as breezy trades persist.

Marine

High pressure to the north-northeast of the area will remain in place for the next several days, keeping moderate to locally strong trade winds across the islands. The current Small Craft Advisory (SCA) is in effect for the typical windy areas as well as the Oahu Kauai channel. A week trough northeast of the islands is expected to marginally weaken trade winds today. This will bring the locally strong winds back to the typical windy waters around the Big Island and Maui, as well as windward Maui. SCA winds for typical windy areas are then possible through the weekend.
Surf along south facing shores will be small today and tonight with mainly background south and southeast energy. A small to moderate, long- period, south southwest swell will build Friday evening into Sunday and help boost south shore surf heights back up to near or above the September average. This swell will then gradually decrease next week.
Surf along north facing shores should see a small increase today as a short period northerly swell fills in. This small bump is expected to peak on Friday out of the north to north- northeast direction, followed by a short period north northwest swell this weekend. Moderate to locally strong trades near and upstream of the area will lead to choppy conditions along east facing shores over the next several days. A slight increase of windswell is expected over the weekend due to a fetch of strong winds northeast of the state.

Fire weather

Humidity levels and wind speeds will remain just below critical fire weather thresholds this week. A few periods of unsettled weather conditions will increase humidity levels, clouds and shower chances from Friday night through Saturday, and from Tuesday morning into Wednesday. Temperature inversion heights near the Big Island and Maui today will range from 6,000 to 7,000 feet elevation.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST early this morning for Kauai Leeward Waters, Kauai Channel.
Small Craft Advisory until 6 PM HST this evening for Maui County Windward Waters.
Small Craft Advisory until 6 PM HST Friday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov