West Side

Today: Breezy. Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 82 to 88. Northeast winds 10 to 25 mph increasing to 20 to 25 mph in the afternoon. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 70 to 77. Northeast winds 10 to 25 mph. Chance of rain 50 percent.

Saturday: Breezy. Partly sunny with scattered showers. Highs 82 to 87. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

South Side

Today: Sunny until late afternoon then becoming partly sunny. Breezy. Isolated showers late in the afternoon. Highs around 91. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with isolated showers. Lows 70 to 78. Northeast winds 10 to 25 mph decreasing to 10 to 15 mph after midnight. Chance of rain 20 percent.

Saturday: Breezy. Mostly sunny with isolated showers. Highs around 90. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

North Shore

Today: Mostly cloudy. Breezy. Scattered showers until late afternoon, then showers late in the afternoon. Highs 81 to 86 near the shore to around 68 near 5000 feet. East winds up to 20 mph. Chance of rain 80 percent.

Tonight: Cloudy with showers. Lows around 74 near the shore to around 54 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 80 percent.

Saturday: Cloudy and breezy. Showers in the morning, then numerous showers in the afternoon. Highs 80 to 85 near the shore to around 67 near 5000 feet. East winds up to 20 mph. Chance of rain 80 percent.

Central Maui

Today: Mostly sunny until late afternoon then becoming partly sunny. Breezy. Isolated showers early in the afternoon. Scattered showers late in the afternoon. Highs 83 to 91. Northeast winds 10 to 25 mph increasing to 20 to 25 mph in the afternoon. Chance of rain 40 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 72. Northeast winds 10 to 20 mph. Chance of rain 40 percent.

Saturday: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 83 to 91. Northeast winds 10 to 25 mph. Chance of rain 40 percent.

Upcountry

Today: Windy. Mostly sunny with scattered showers. Highs around 64 at the visitor center to around 69 at the summit. East winds up to 30 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 51 at the visitor center to around 48 at the summit. East winds up to 25 mph. Chance of rain 50 percent.

Saturday: Breezy. Partly sunny with showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs around 64 at the visitor center to around 69 at the summit. East winds up to 20 mph. Chance of rain 80 percent.

East Maui

Today: Mostly cloudy. Breezy. Scattered showers until late afternoon, then showers late in the afternoon. Highs 81 to 86 near the shore to around 68 near 5000 feet. East winds up to 20 mph. Chance of rain 80 percent.

Tonight: Cloudy with showers. Lows around 74 near the shore to around 54 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 80 percent.

Saturday: Cloudy and breezy. Showers in the morning, then numerous showers in the afternoon. Highs 80 to 85 near the shore to around 67 near 5000 feet. East winds up to 20 mph. Chance of rain 80 percent.

Lanai City

Today: Mostly sunny until late afternoon then becoming partly sunny. Breezy. Isolated showers in the afternoon. Highs 75 to 83. Northeast winds 10 to 25 mph increasing to 20 to 25 mph in the afternoon. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with isolated showers. Lows around 67. Northeast winds 15 to 25 mph. Chance of rain 20 percent.

Saturday: Breezy. Mostly sunny with isolated showers. Highs 75 to 83. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Kaunakakai

Today: Breezy. Mostly sunny with isolated showers in the morning, then mostly cloudy with scattered showers in the afternoon. Highs 74 to 91. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 61 to 76. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Saturday: Breezy. Mostly cloudy with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 74 to 90. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Moderate to breezy trade winds remains in the forecast for the foreseeable future. Brief passing showers will continue today, 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 later this afternoon 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 with the potential for enhanced wet weather trends.

Discussion

The morning satellite picture shows the subtropical jet stream producing high level cirrus clouds over the Big Island as an long unstable low level band of clouds associated with an old East Pacific cold front rides into the Hawaiian Islands on the trade winds.
A high pressure ridge north of the island chain will keep moderate to breezy trade winds in forecast for the foreseeable future. A long unstable cloud band, associated with the remnants of an old East Pacific cold front will ride into the islands on the trade winds later this afternoon. This low level cloud band will push temperature inversion into the 7,000 to 10,000 foot range and drive clouds to higher heights, allowing wet weather trends for all islands starting later this afternoon and lasting into Saturday. Fairly significant storm total rainfall amounts in the 0.50 to 1.00 inch range will tend to favor windward and mountain areas. However, the strongest showers in this band will likely bring some much needed rainfall, although at lower amounts, to favored leeward areas. The southern portion of this unstable cloud band will linger along the windward slopes of the Big Island through Sunday. 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. A Small Craft Advisory (SCA) is in effect for the typical windy areas around Maui and the Big Island until 6 PM Saturday evening. Trades should gradually ease Sunday into early next week as the high weakens to our north.
Surf along south facing shores should see an increase this weekend as a small to moderate, long-period, south-southwest swell gradually fills in later today into Saturday and peaks late Saturday into Sunday. Surf heights should rise back up to near or above the September averages over the weekend then gradually decline next week.
Surf along north facing shores saw a small increase yesterday due to a short-period north swell. This small bump is expected to peak today, 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.

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 starting later this afternoon through Saturday, with another round from Tuesday morning into Wednesday. Temperature inversion heights near the Big Island and Maui today will range from 7,000 to 8,000 feet elevation.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov