West Side

Today: Sunny and breezy. Isolated showers in the morning. Highs 79 to 86. Northeast winds 15 to 25 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Breezy. Lows 71 to 77. Northeast winds 15 to 25 mph.

Sunday: Sunny and breezy. Highs 80 to 86. Northeast winds 10 to 25 mph.

South Side

Today: Sunny and breezy. Highs 84 to 89. Northeast winds up to 25 mph increasing to 10 to 25 mph in the afternoon.

Tonight: Mostly clear. Breezy. Lows 70 to 79. Northeast winds 10 to 20 mph decreasing to up to 20 mph after midnight.

Sunday: Sunny and breezy. Highs around 87. Northeast winds up to 20 mph increasing to 10 to 20 mph in the afternoon.

North Shore

Today: Breezy. Mostly cloudy with numerous showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs around 81 near the shore to around 67 near 5000 feet. East winds up to 20 mph. Chance of rain 70 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows around 73 near the shore to around 57 near 5000 feet. Southeast winds up to 20 mph. Chance of rain 50 percent.

Sunday: Breezy. Mostly sunny with scattered showers. Highs around 81 near the shore to 66 to 71 near 5000 feet. East winds up to 20 mph. Chance of rain 40 percent.

Central Maui

Today: Sunny and breezy. Isolated showers in the morning. Highs 81 to 87. East winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Breezy. Lows 70 to 75. East winds 10 to 20 mph.

Sunday: Sunny and breezy. Highs 81 to 87. Northeast winds 10 to 25 mph.

Upcountry

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 64 at the visitor center to around 62 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy. Breezy. Isolated showers in the evening, then scattered showers after midnight. Lows around 54 at the visitor center to around 52 at the summit. East winds up to 20 mph. Chance of rain 50 percent.

Sunday: Breezy. Mostly sunny with isolated showers. Highs around 70 at the visitor center to around 73 at the summit. East winds up to 20 mph. Chance of rain 20 percent.

East Maui

Today: Breezy. Mostly cloudy with numerous showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs around 81 near the shore to around 67 near 5000 feet. East winds up to 20 mph. Chance of rain 70 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows around 73 near the shore to around 57 near 5000 feet. Southeast winds up to 20 mph. Chance of rain 50 percent.

Sunday: Breezy. Mostly sunny with scattered showers. Highs around 81 near the shore to 66 to 71 near 5000 feet. East winds up to 20 mph. Chance of rain 40 percent.

Lanai City

Today: Sunny and windy. Highs 73 to 82. Northeast winds 10 to 30 mph.

Tonight: Mostly clear. Breezy. Lows 68 to 73. Northeast winds 10 to 25 mph.

Sunday: Sunny and breezy. Highs 78 to 84. Northeast winds 10 to 25 mph.

Kaunakakai

Today: Sunny and breezy. Highs 71 to 89. Northeast winds 15 to 25 mph.

Tonight: Mostly clear. Breezy. Lows 63 to 77. Northeast winds 10 to 25 mph.

Sunday: Sunny and breezy. Highs 77 to 89. Northeast winds 10 to 20 mph.

Detailed Forecast

Synopsis

Breezy trades continue well into next week. Showers will generally favor windward and mauka areas, particularly during the overnight through early morning hours each day. An uptick in moisture next week could increase shower activity. Tropical Storm Lowell remains far SE of the main Hawaiian Islands, and uncertainty in its track, timing, and intensity forecast remains high at this time.

Discussion

The early morning 12z soundings from Lihue and Hilo showed a slightly elevated inversion at around 6500-8500 feet. This, combined with a band of moisture seen on regional satellite imagery embedded within breezy trades, has resulted in an uptick in low clouds and showers during the overnight through early morning hours. Surface observations show that several windward locations, particularly across Maui and the Big Island, picked up between a half inch and one inch since yesterday evening.
A drier trade wind pattern will resume today as mid- and upper level ridging remains anchored near the area and the band of moisture that moved through overnight exits the region. Breezy trade winds will prevail for the next several days as strong high pressure becomes nearly stationary north of the main Hawaiian Islands. Occasional showers embedded within the trades will favor windward and mauka areas, particularly during the overnight through early morning hours each day. As the previous discussions have mentioned, an uptick in moisture by the middle of next week could increase trade wind showers once again.
The National Hurricane Center in Miami continues to track Tropical Storm Lowell, which as of the 11 PM HST advisory was located about 1430 miles ESE of Hilo, moving west around 8 mph. Lowell is expected to strengthen into a hurricane early next week as it continues to move westward. There is a great amount of uncertainty in the forecast thereafter, as it remains to be seen how Tropical Storm Karina (also in the East Pacific) could influence Lowell's steering flow. Should steering flow weaken as depicted in some global models, this would delay any potential arrival to/around the Hawaiian islands to beyond the 7 day forecast period.

Aviation

For 12Z – Nocturnal showers under moderate trades bringing mostly VFR to occasional MVFR conditions overnight. Generally, VFR through the TAF period and occasional MVFR conditions due to passing showers/lower CIGs, highest chances this afternoon and overnight. Expect low CIGs and SHRA over windward and mauka slopes most areas and with VCSH for those TAFs.
AIRMET Tango is in effect for mod low-level turb lee of terrain and may be needed for a few days.

Marine

The subtropical ridge will remain locked in place north of the Hawaiian Islands through much of next week keeping moderate to locally strong trade winds in the forecast for the foreseeable future. A Small Craft Advisory (SCA) has been extended for the windier waters and channels around Maui County and the Big Island through Sunday afternoon. These SCA conditions look to persist through the first half of next week.
Tropical cyclone Lowell may move into the Hawaiian Region potentially bringing an area of hurricane force winds into the southern offshore waters by the end of next week.
The south swell that peaked just below advisory thresholds on Friday, will slowly decline over the next few days. Another south swell will increase surf heights starting on Tuesday, peaking on Wednesday near High Surf Advisory levels, then slowly fading into the end of next week.
Surf along east facing shores will remain choppy in response to the locally strong trade winds over and upstream of the islands. A small medium period east swell from Tropical Storm Iselle has filled in and will hold through the day.

Fire weather

Breezy trades will continue through the weekend and into next week, but dewpoints near 70 degrees will keep RH from reaching critical thresholds. Rainfall will be confined mainly to windward and mauka zones during this time. Today's inversion is expected to be around 8000 feet or so, with only minor day to day fluctuations expected through the weekend.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Sunday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov