West Side

Today: Mostly sunny. Breezy. Isolated showers in the morning. Highs 81 to 87. Northeast winds up to 25 mph shifting to the east 10 to 25 mph in the afternoon. Gusts up to 45 mph. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Isolated showers. Lows 67 to 73. East winds 10 to 20 mph. Chance of rain 20 percent.

Wednesday: Breezy. Mostly sunny with isolated showers. Highs 81 to 86. East winds 10 to 20 mph. Chance of rain 20 percent.

South Side

Today: Mostly sunny. Breezy. Highs around 89. Northeast winds 10 to 25 mph with gusts to 45 mph.

Tonight: Partly cloudy. Lows 66 to 74. Northeast winds 10 to 15 mph.

Wednesday: Mostly sunny. Highs around 90. Northeast winds 10 to 15 mph.

North Shore

Today: Breezy. Partly sunny with scattered showers. Highs 80 to 86 near the shore to around 66 near 5000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with numerous showers. Lows around 70 near the shore to around 51 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Wednesday: Mostly cloudy. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 80 to 86 near the shore to around 68 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Central Maui

Today: Breezy. Partly sunny with isolated showers in the morning, then mostly sunny in the afternoon. Highs 82 to 90. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Isolated showers. Lows 67 to 72. East winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny. Isolated showers in the morning. Highs 83 to 90. East winds 10 to 15 mph. Chance of rain 20 percent.

Upcountry

Today: Windy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs around 66 at the visitor center to around 73 at the summit. East winds 10 to 30 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Breezy. Scattered showers. Lows around 47 at the visitor center to around 49 at the summit. East winds 15 to 25 mph. Chance of rain 50 percent.

Wednesday: Breezy. Mostly sunny with scattered showers. Highs around 65 at the visitor center to around 70 at the summit. East winds 10 to 25 mph. Chance of rain 50 percent.

East Maui

Today: Breezy. Partly sunny with scattered showers. Highs 80 to 86 near the shore to around 66 near 5000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with numerous showers. Lows around 70 near the shore to around 51 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Wednesday: Mostly cloudy. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 80 to 86 near the shore to around 68 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Lanai City

Today: Mostly sunny. Breezy. Highs 75 to 82. Northeast winds 10 to 25 mph.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Breezy. Lows around 64. Northeast winds 10 to 20 mph.

Wednesday: Mostly sunny in the morning then becoming partly sunny. Highs 74 to 82. Northeast winds 10 to 15 mph.

Kaunakakai

Today: Mostly sunny. Breezy. Isolated showers in the morning. Highs 71 to 89. Northeast winds 10 to 25 mph with gusts to 45 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy in the evening, then mostly cloudy with scattered showers after midnight. Lows 59 to 73. East winds 10 to 25 mph. Chance of rain 40 percent.

Wednesday: Mostly sunny. Breezy. Isolated showers in the morning. Highs 73 to 90. East winds 10 to 20 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A strong high pressure ridge north of the Hawaiian Islands will keep breezy to windy trade winds in the forecast for one more day today. The strongest winds will develop over the windier areas of Maui and Hawaii Counties. Dry weather conditions will combine with these strong gusty winds to produce elevated fire danger across the state each afternoon, mainly over the drier leeward slopes. Wind speeds will decrease from Wednesday onward. A slight increase in shower trends remains in the forecast from Wednesday night onward.

Discussion

The satellite picture this morning shows bands of fairly stable clouds moving into the windward mountain slopes of each island. A ridge aloft will produce enough downward motions (subsidence) to limit vertical cloud growth and thereby produce only brief passing light showers across the Hawaii Region. Temperature inversion heights today will range from 5,000 to 6,000 feet today due to the stronger subsidence. These temperature inversion heights will lift into the 7,000 to 8,000 foot range from Wednesday onward as the high pressure ridge weakens, slightly increasing shower trends statewide. An upper level low just southwest of the island chain will produce bands of high level cirrus ice crystal clouds across the state, enhancing sunrise and sunset colors.
The main weather story today will continue to focus on the breezy to windy easterly trade winds blowing across the state. A Wind Advisory remains in effect until this evening for windier areas of Maui and Hawaii Counties; including the summits of Mauna Kea and Mauna Loa on the Big Island. The pattern will begin to change on Wednesday as the high pressure ridge north of the state weakens. These strong trade wind speeds will start to decrease to more moderate to breezy levels for the rest of the week.
Relatively dry humidity levels will combine with these breezy to windy conditions to elevate fire weather conditions across the state, mainly over drier and windier leeward areas. Please refer to the Fire Weather section below for more details.

Aviation

Stable conditions with breezy to windy trade winds will continue across the state today. Passing showers will favor windward and mountain areas in the overnight to early morning hours, bringing the potential for brief MVFR conditions. Otherwise, VFR conditions will prevail.
AIRMET Tango remains in effect for moderate low-level turbulence over and downwind of island terrain. This AIRMET will likely persist as strong trade winds remain in the forecast.

Marine

High pressure will remain nearly stationary far north of the islands through today, which will support continued fresh to strong trades across the area. The Small Craft Advisory remains in effect for all Hawaiian coastal waters through 6 PM HST Tuesday. The surface high will move eastward and weaken slightly during the second half of the week, but winds are likely to remain breezy to locally strong in the windier channels and waters of Maui County and the Big Island. Therefore, the SCA will likely need to be extended for these areas. Additionally, seas may also approach 10 feet at times in the Alenuihaha Channel over the next couple of days.
South shore surf is expected to slowly decline as the current small south swell fades. The next small, long- period south swell is expected to arrive this evening and peak on Wednesday. This swell may boost south-facing shore surf heights slightly from Tuesday night through Wednesday before gradually easing again through Friday. Guidance shows that another, smaller long-period reinforcement could arrive Friday night into the first half of the weekend.
Surf along east-facing shores will be rough and choppy for the next couple of days in response to the gusty easterly trade winds. As the trades ease a bit during the latter portion of the week, surf along east-facing shores will also trend down.

Fire weather

Breezy to windy trade winds with stable and relatively dry conditions will persist today. Minimum relative humidity at lower leeward elevations will likely fall to around 45 percent this afternoon, and with the temperature inversion dropping to as low as 5,000 feet, winds will become gusty over and downwind of island mountains. This will result in near critical fire weather conditions over dry leeward areas in the afternoon hours, though no headlines (watches or warnings) are due since the Keetch Byram Drought Index will remain below the 600 threshold at Honolulu.

HFO Watches/Warnings/Advisories

Wind Advisory until 6 PM HST this evening for windier areas of Maui and Hawaii Counties, including the highest summits of the Big Island.
Small Craft Advisory until 6 PM HST this evening for all Hawaiian waters.

Data Courtesy of NOAA.gov