West Side

Today: Partly sunny with scattered showers. Highs 77 to 82. South winds 10 to 15 mph decreasing to up to 15 mph in the afternoon. Chance of rain 40 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Locally heavy rainfall possible after midnight. Lows 67 to 73. South winds up to 10 mph. Chance of rain 40 percent.

Friday: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Locally heavy rainfall possible in the morning. Highs around 80. Light winds. Chance of rain 20 percent.

South Side

Today: Mostly sunny with isolated showers. Highs around 84. Southwest winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Locally heavy rainfall possible after midnight. Lows 66 to 75. Southwest winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Friday: Mostly sunny in the morning then becoming partly sunny. Highs around 85. Light winds.

North Shore

Today: Mostly sunny with isolated showers. Highs around 82 near the shore to around 66 near 5000 feet. Light winds becoming northwest up to 10 mph in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 70 near the shore to around 51 near 5000 feet. Light winds. Chance of rain 20 percent.

Friday: Mostly sunny in the morning then becoming mostly cloudy. Isolated showers. Locally heavy rainfall possible in the morning. Highs around 81 near the shore to around 66 near 5000 feet. Light winds. Chance of rain 20 percent.

Central Maui

Today: Mostly sunny with isolated showers. Highs 81 to 86. South winds up to 15 mph shifting to the southwest in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Locally heavy rainfall possible after midnight. Lows 66 to 71. South winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Friday: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs 81 to 86. Light winds becoming northeast up to 10 mph in the afternoon. Chance of rain 20 percent.

Upcountry

Today: Mostly sunny with isolated showers. Highs around 61 at the visitor center to around 65 at the summit. Southwest winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 46 at the visitor center to around 43 at the summit. South winds up to 15 mph. Chance of rain 20 percent.

Friday: Mostly sunny in the morning then becoming partly sunny. Highs around 61 at the visitor center to around 65 at the summit. Southwest winds up to 10 mph.

East Maui

Today: Mostly sunny with isolated showers. Highs around 82 near the shore to around 66 near 5000 feet. Light winds becoming northwest up to 10 mph in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 70 near the shore to around 51 near 5000 feet. Light winds. Chance of rain 20 percent.

Friday: Mostly sunny in the morning then becoming mostly cloudy. Isolated showers. Locally heavy rainfall possible in the morning. Highs around 81 near the shore to around 66 near 5000 feet. Light winds. Chance of rain 20 percent.

Lanai City

Today: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Locally heavy rainfall possible in the afternoon. Highs 71 to 79. South winds 10 to 15 mph. Chance of rain 60 percent.

Tonight: Mostly cloudy with scattered showers. Locally heavy rainfall possible after midnight. Lows 63 to 68. South winds around 10 mph in the evening becoming light. Chance of rain 50 percent.

Friday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Locally heavy rainfall possible in the morning. Highs 71 to 79. Light winds. Chance of rain 30 percent.

Kaunakakai

Today: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Locally heavy rainfall possible in the afternoon. Highs 69 to 85. South winds 10 to 15 mph decreasing to up to 15 mph in the afternoon. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Locally heavy rainfall possible after midnight. Lows 58 to 72. South winds up to 10 mph in the evening becoming light. Chance of rain 50 percent.

Friday: Mostly cloudy with scattered showers. Locally heavy rainfall possible in the morning. Highs 69 to 85. Light winds. Chance of rain 50 percent.

Detailed Forecast

Synopsis

A band of thick clouds with moderate to locally heavy showers and a few thunderstorms will linger near Kauai and Oahu today associated with a dissipating front. The band of clouds will become more diffused and lift northwestward back over Kauai County tonight, providing continued chances showers with drying trend for Molokai thru Oahu. Ridging aloft will slowly build back in over the islands marking a return of more stable easterly trade wind weather this weekend. However, cloudy conditions will persist for the next couple of days. Moderate to strong trades with more typical stable conditions will build back Sunday into early next week.

Discussion

An active weather pattern continues across the western portion of the state this morning as a weakening front remains stalled west of Kauai. A band of clouds with heavy showers with isolated thunderstorms training from the southwest to northeast has remained nearly stationary over northern Oahu. Rainfall totals overnight range from 1 to 3 inches. Convective activity shows a slight downward trend this morning within the main narrow rainband lingering over northern Oahu. Drier conditions have be observed over the rest of the state.
Hi- res models continue to suggest the band of showers to train over Oahu through much of the day while gradually becoming more diffused with a few stray showers reaching Molokai. This band will shift northwestward later this morning and afternoon, keeping chances of heavy rain possible for Oahu and Kauai. Southeast winds build in over Maui County and the Big Island.
The Flood Watch will continue through this afternoon for Kauai County and Oahu. The watch may need to be extended for Kauai through Friday morning as another upper level shortwave trough swings down increasing instability over Kauai. Depending on surface level convergence and where the lingering band of showers ends up this afternoon and evening, this pattern could reinvigorate an active shower pattern through the evening hours. Chances for light to moderate showers will increase along along southeast exposures of the Big Island and Maui County tonight into Friday morning as disturbance move in from the south.
Friday, a low level ridge will build in over the islands from the south drawing low level moisture up to the mid levels, generating a mix of high, mid, and low level layered clouds. Best chances of showers will linger over the western half of the state where the greatest upper level instability will linger.
Saturday, light to gentle easterly trade winds will return as a high builds northeast of the state. Low to upper level ridging will still allow moisture being drawn up over the state from the southwest to northeast keeping mostly cloudy conditions. Expect showers to mainly focus along windward and mauka areas.
Sunday into early next week trades are expected to strengthen to moderate to strong levels with more stable conditions developing into early next week. Bands of showers trapped within the trade wind flow will remain focused mainly along windward and mauka areas.

Aviation

A convective cloud band with embedded thunderstorms continues to move into Oahu this morning. Expect periods of MVFR and isolated IFR conditions in showers and thunderstorms along the cloud band. These enhanced showers will continue today over Oahu, then slowly drift these low cloud CIGs and showers northward into Kauai later tonight. A weak disturbance moving up from the south will bring periods of MVFR conditions with additional low clouds and enhanced showers into the islands of Maui and the Big Island on Friday.
AIRMET Sierra remains in effect for tempo mountain obscurations across Oahu and Molokai this morning. Mountain obscurations will likely return to Kauai later this afternoon. IFR conditions over Lanai will continue through the morning hours.
AIRMET Tango is in effect for tempo moderate turbulence below 080 over and north through east of island terrain on Oahu and Molokai. This low level turbulence should decrease this morning.

Marine

A trough near Kauai and Oahu has brought isolated to scattered thunderstorms and numerous showers along the boundary overnight and looks to continue through Friday over the western coastal waters. Gentle to locally moderate southerly winds are expected over the coastal waters today except areas along the boundary that could reach Small Craft Advisory criteria winds associated with the thunderstorms. The general southerly wind flow will gradually decrease to light to gentle through Friday night. Easterly trade winds look to slowly build from the east to west this weekend with the potential for Small Craft Advisory over the windier waters and channels around Maui County and the Big Island by Sunday into early next week.
Surf along north facing shores will remain elevated with a mix across the spectrum from the west northwest to the north. The new north northwest swell will look to build throughout the day well into High Surf Advisory (HSA) criteria and peak this afternoon into the evening. The HSA may need to be extended through Friday. The slightly smaller west northwest swell will look to fill in this morning and quickly fade out Friday. A combination of the north northwest and north swells will keep surf heights elevated through the weekend but guidance shows it at or just below HSA levels.
East facing shores will remain small given the lack of trade winds upstream of the islands but areas exposed to the north swell will see an uptick through the rest of the week. As trade winds fill in later this weekend, east shores could become rough and choppy by early next week. Surf along south facing shores will remain small today due to short period wind wave chop, mainly over the western islands along the boundary but elsewhere should remain flat to tiny through the weekend.

Fire weather

Wet weather conditions and isolated thunderstorms will trend down slightly today across the western islands. Periods of clouds and scattered showers are expected for Molokai and Lanai, with drier conditions remaining in place over Maui and the Big Island. Trade winds and increasingly stable conditions will slowly return to the western half of the state from Friday into the weekend. Wind speeds and humidity levels will keep weather conditions below critical fire thresholds throughout next week.

HFO Watches/Warnings/Advisories

Flood Watch through this afternoon for Niihau, Kauai Leeward, Kauai Mountains, Waianae Coast, Oahu North Shore, Olomana, Central Oahu, Waianae Mountains, Kauai North, Kauai East, Kauai South, East Honolulu, Honolulu Metro, Ewa Plain, Koolau Windward, Koolau Leeward.
High Surf Advisory until 6 AM HST Friday for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Kauai North.
High Surf Advisory until 6 AM HST Friday for Maui Windward West, Molokai Windward, Molokai North, Molokai West, Maui Central Valley North, Windward Haleakala.
Small Craft Advisory until 6 AM HST Friday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Oahu Leeward Waters, Kaiwi Channel, Maui County Windward Waters.

Data Courtesy of NOAA.gov