West Side

Today: Breezy. Mostly sunny with isolated showers. Highs 81 to 86. Northeast winds 15 to 25 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows 68 to 74. East winds 10 to 20 mph. Chance of rain 20 percent.

Tuesday: Sunny with isolated showers. Highs 80 to 85. East winds 10 to 15 mph. Chance of rain 20 percent.

South Side

Today: Mostly sunny. Breezy. Highs around 89. Northeast winds up to 15 mph increasing to 10 to 20 mph in the afternoon.

Tonight: Mostly clear. Breezy. Lows 68 to 75. Northeast winds 10 to 20 mph.

Tuesday: Sunny. Highs around 88. North winds 10 to 15 mph.

North Shore

Today: Breezy. Partly sunny with scattered showers. Highs 78 to 84 near the shore to around 66 near 5000 feet. East winds up to 20 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 71 near the shore to around 52 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tuesday: Partly sunny with scattered showers. Highs 78 to 84 near the shore to around 66 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Central Maui

Today: Mostly sunny. Breezy. Highs 82 to 89. Northeast winds 10 to 25 mph.

Tonight: Partly cloudy. Breezy. Isolated showers in the evening. Lows 67 to 72. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tuesday: Sunny. Highs 81 to 88. Northeast winds 10 to 15 mph.

Upcountry

Today: Breezy. Mostly sunny with isolated showers. Highs around 63 at the visitor center to around 69 at the summit. East winds up to 25 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Breezy. Scattered showers in the evening, then isolated showers after midnight. Lows 44 to 54. East winds up to 25 mph increasing to 10 to 25 mph after midnight. Chance of rain 50 percent.

Tuesday: Mostly sunny. Breezy. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 62 at the visitor center to around 68 at the summit. East winds 15 to 20 mph. Chance of rain 50 percent.

East Maui

Today: Breezy. Partly sunny with scattered showers. Highs 78 to 84 near the shore to around 66 near 5000 feet. East winds up to 20 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 71 near the shore to around 52 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tuesday: Partly sunny with scattered showers. Highs 78 to 84 near the shore to around 66 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Lanai City

Today: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 73 to 81. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Breezy. Isolated showers in the evening. Lows around 65. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tuesday: Mostly sunny. Isolated showers in the afternoon. Highs 72 to 80. East winds up to 15 mph. Chance of rain 20 percent.

Kaunakakai

Today: Mostly sunny. Breezy. Highs 72 to 90. East winds 10 to 20 mph.

Tonight: Partly cloudy. Breezy. Isolated showers in the evening. Lows 59 to 73. East winds 15 to 20 mph. Chance of rain 20 percent.

Tuesday: Sunny and breezy. Highs 71 to 89. East winds 15 to 25 mph.

Detailed Forecast

Synopsis

Fairly stable and breezy trade winds will start the week as a broad high pressure ridge remains in place far north of the island chain. Trade wind speeds will decrease slightly to more moderate levels from Tuesday through Friday, breezy trade winds return by the weekend. A few showers are possible in this pattern especially along the windward and mountain slopes, favoring the overnight to early morning hours.

Discussion

This mornings satellite imagery shows a few bands of unsettled clouds riding into the windward slopes of each island on the easterly trade winds. These brief passing shower trends will diminish later this morning. Upper air weather balloon soundings, from 2 AM HST (12Z) at Lihue and Hilo, show temperature inversion heights around 5,000 feet and 6,000 feet respectively. These low inversion heights will reduce vertical cloud development and limit shower coverage. A few high level cirrus clouds will pass over the islands today produced by a weak upper low centered just west of Kauai.
The high pressure ridge far north of the Hawaiian Islands will remain in place through the week. A passing low pressure system moving through the Central Pacific basin will weaken the strength of this ridge slightly from Tuesday onward. Wind speed trends will decrease slightly into the more moderate levels through Friday. The ridge will then build back into the region by this weekend with a return to more breezy easterly trade winds.
Fairly stable conditions remain in the forecast for the next seven days. Low temperature inversion heights in the 5,000 to 7,000 foot range will limit most of the shower activity to windward and mountain areas in the overnight to early morning hours. A few ripples in the buoyancy force show up in the forecast guidance that may produce a few variations in this stable theme, leading to brief increases to local shower activity at times over some island regions. However, rainfall amounts will remain on the low side in this stable high pressure ridge pattern.

Aviation

Breezy trade winds with mostly stable conditions expected to last into Tuesday. Wind speeds will decrease to more moderate levels from Tuesday onward. Shower activity will be limited to windward and mountain airfields, favoring the overnight to early morning hours.
AIRMET Tango remains in effect for moderate turbulence over and south through west of island mountains.

Marine

A high pressure north of the state will drive trades through the week. A slight weakening trend in the winds is expected as the high moves eastward. A Small Craft Advisory (SCA) for the windier waters and channels near Maui and the Big Island goes through 6AM Wednesday with a likely extension.
A series of small, long-period, south swells will help boost surf heights along south facing shores though the week. The current south swell will decline over the next couple days followed by another south swell from Wednesday into Thursday.
Rough and choppy surf along east facing shores will continue this week. Surf will remain nearly flat along north facing shores throughout the forecast period.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov