West Side

Today: Mostly sunny. Breezy. Highs 83 to 88. East winds up to 20 mph increasing to northeast in the afternoon.

Tonight: Partly cloudy. Breezy. Isolated showers after midnight. Lows 70 to 77. East winds 15 to 25 mph. Chance of rain 20 percent.

Sunday: Mostly sunny. Breezy. Isolated showers in the morning. Highs 82 to 87. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

South Side

Today: Sunny and breezy. Highs around 91. Northeast winds up to 20 mph.

Tonight: Mostly clear. Breezy. Lows 71 to 77. Northeast winds up to 20 mph.

Sunday: Sunny and breezy. Highs around 90. Northeast winds up to 20 mph increasing to 10 to 20 mph in the afternoon.

North Shore

Today: Breezy. Mostly sunny with isolated showers. Highs 81 to 87 near the shore to around 70 near 5000 feet. East winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows around 73 near the shore to around 55 near 5000 feet. Southeast winds up to 20 mph. Chance of rain 50 percent.

Sunday: Breezy. Partly sunny with scattered showers. Highs 81 to 88 near the shore to around 69 near 5000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

Central Maui

Today: Sunny and breezy. Highs 83 to 91. East winds up to 25 mph increasing to 15 to 25 mph in the afternoon.

Tonight: Mostly clear. Breezy. Lows 70 to 75. East winds 10 to 25 mph.

Sunday: Mostly sunny. Breezy. Highs 83 to 90. Northeast winds 10 to 25 mph.

Upcountry

Today: Sunny and breezy. Scattered showers in the morning. Highs around 69 at the visitor center to around 71 at the summit. East winds up to 20 mph. Chance of rain 30 percent.

Tonight: Partly cloudy. Breezy. Isolated showers after midnight. Lows around 53 at the visitor center to around 49 at the summit. East winds up to 20 mph increasing to 10 to 20 mph after midnight. Chance of rain 20 percent.

Sunday: Sunny and breezy. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 68 at the visitor center to around 71 at the summit. East winds up to 20 mph becoming 10 to 15 mph in the afternoon. Chance of rain 40 percent.

East Maui

Today: Breezy. Mostly sunny with isolated showers. Highs 81 to 87 near the shore to around 70 near 5000 feet. East winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows around 73 near the shore to around 55 near 5000 feet. Southeast winds up to 20 mph. Chance of rain 50 percent.

Sunday: Breezy. Partly sunny with scattered showers. Highs 81 to 88 near the shore to around 69 near 5000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

Lanai City

Today: Sunny and breezy. Highs 77 to 84. Northeast winds up to 20 mph.

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

Sunday: Sunny and breezy. Highs 76 to 84. Northeast winds 10 to 25 mph.

Kaunakakai

Today: Sunny and breezy. Highs 76 to 91. East winds 10 to 20 mph.

Tonight: Partly cloudy. Breezy. Isolated showers after midnight. Lows 63 to 76. East winds 10 to 20 mph. Chance of rain 20 percent.

Sunday: Sunny and breezy. Isolated showers in the morning. Highs 76 to 91. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Broad high pressure will build over the region allowing trades to strengthen to moderate to locally breezy through much of the weekend. By Sunday, a low-level trough associated with the remnants of former Tropical Cyclone Ivo will propagate into the vicinity of the Hawaiian Islands, bringing and increase of clouds and shower activity to predominately windward and mauka areas through Monday. Thereafter, dry and stable conditions return and remain through the remainder of the week.

Discussion

Latest satellite imagery showcases a low-level trough well northwest of Kauai continuing to slowly propagate away from the islands. Broad high pressure ridging northeast of the Hawaiian Islands quickly fills the void, allowing trades to strengthen to moderate to locally breezy over the islands. Mid-level water vapor imagery continues to depict drier air east of the islands, reintroducing drier and more stable conditions through the weekend.
Deterministic model guidance continues to show another low-level trough associated with the remnants of former Tropical Cyclone Ivo moving near the state on Sunday and Monday. As the trough moves into the vicinity of the islands on Sunday, expect humidity levels to steadily increase. Inversion heights will also lift to around 8,000 to 9.000 feet on Sunday and Monday, which will help to enhance clouds and showers in a moderate to breezy trade pattern.
The latest model guidance have not been in the best of agreement with regards to the aforementioned trough. The GFS has depicted the trough moving toward the center of the islands, which would result in a day or two of wet trades across most of the islands. Conversely, the ECMWF depicts the trough shimmying further north, resulting less shower activity to the islands, limiting activity to predominately Oahu and Kauai. Given that remnant tropical system tend to be smaller in size, the track of this trough may oscillate further north or south as time passes. It will be critical to see what Hi-res model data shows as it becomes more readily available, and then confidence should increase track of the trough as it approaches the island chain.
By Tuesday, the second low-level trough is progged to exit the region to the west, with high pressure quickly rebuilding across the area once again. This will result in dry and stable conditions returning to the state under moderate to breezy trades. Expect a return to typical summer-like conditions at this time, with limited clouds and showers over windward and mauka areas.

Aviation

Moderate trades gradually strengthen as a low-level trough exits the region. Expect brief periods of MVFR conditions in clouds or shower activity, retained to windward and mauka during this time. Otherwise, VFR conditions prevail.
No AIRMETs in effect at this time.

Marine

A surface ridge building north of the state will allow fresh to locally strong easterly trades to persist across the local waters through this weekend. A Small Craft Advisory (SCA), has been expanded in area to include all coastal water and channel zones surrounding Maui and the Big Island. The advisory remains in effect through Sunday morning, but will likely need to be extended in time. Trades look to weaken slightly on Monday morning as remnants former Tropical Cyclone Ivo pass from east to west over the islands. Fresh to locally strong trades will rebuild late Monday through mid-week.
A south southwest (190-200) swell was noted at the nearshore buoys this morning at roughly 2 feet 15-16 seconds. This swell will stick around through Sunday and help bump surf heights to around the seasonal average. Several similar small, long- period, southerly swells will affect the waters early to mid next- week and keep small surf near the August average, well below advisory thresholds.
Surf along east facing shores may be slightly elevated and choppy today due to the fresh trades. North facing shores will remain flat to tiny through the forecast period.

Fire weather

Conditions should remain below critical fire weather thresholds into early next week. A low-level trough associated with the remnants of former Tropical Cyclone Ivo will move across the region on Sunday into Monday, bringing an increase in humidity and shower activity. Lower humidity and more stable conditions redevelop on Tuesday as high pressure rebuilds across the islands.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Sunday for Kaiwi Channel, Maui County Windward Waters, Maui County Leeward Waters, Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Windward Waters, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov