West Side

Rest Of Tonight: Partly cloudy. Isolated showers late in the evening. Lows 63 to 70. Light winds. Chance of rain 20 percent.

Monday: Sunny. Isolated showers in the afternoon. Highs 75 to 81. Light winds becoming northwest up to 10 mph in the afternoon. Chance of rain 20 percent.

Monday Night: Partly cloudy with isolated showers. Lows 64 to 70. East winds up to 15 mph. Chance of rain 20 percent.

South Side

Rest Of Tonight: Mostly clear. Isolated showers late in the evening. Lows 62 to 72. Light winds. Chance of rain 20 percent.

Monday: Sunny. Highs around 83. Light winds.

Monday Night: Partly cloudy. Isolated showers in the evening. Lows 62 to 72. Northwest winds up to 10 mph. Chance of rain 20 percent.

North Shore

Rest Of Tonight: Partly cloudy with isolated showers. Lows around 66 near the shore to around 48 near 5000 feet. Light winds becoming southeast up to 10 mph after midnight. Chance of rain 20 percent.

Monday: Mostly sunny with isolated showers. Highs 76 to 81 near the shore to around 65 near 5000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Monday Night: Mostly cloudy in the evening then becoming partly cloudy. Isolated showers. Lows around 67 near the shore to around 49 near 5000 feet. Southeast winds up to 10 mph. Chance of rain 20 percent.

Central Maui

Rest Of Tonight: Mostly clear. Lows around 64. Light winds.

Monday: Sunny. Isolated showers in the afternoon. Highs 78 to 84. North winds up to 10 mph shifting to the northeast in the afternoon. Chance of rain 20 percent.

Monday Night: Partly cloudy. Isolated showers in the evening. Lows 62 to 67. East winds up to 10 mph. Chance of rain 20 percent.

Upcountry

Rest Of Tonight: Partly cloudy. Scattered showers late in the evening, then isolated showers after midnight. Lows 40 to 52. Light winds. Chance of rain 30 percent.

Monday: Mostly sunny with isolated showers. Highs around 60 at the visitor center to around 63 at the summit. Light winds. Chance of rain 20 percent.

Monday Night: Partly cloudy with isolated showers. Lows 41 to 52. East winds up to 10 mph. Chance of rain 20 percent.

East Maui

Rest Of Tonight: Partly cloudy with isolated showers. Lows around 66 near the shore to around 48 near 5000 feet. Light winds becoming southeast up to 10 mph after midnight. Chance of rain 20 percent.

Monday: Mostly sunny with isolated showers. Highs 76 to 81 near the shore to around 65 near 5000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Monday Night: Mostly cloudy in the evening then becoming partly cloudy. Isolated showers. Lows around 67 near the shore to around 49 near 5000 feet. Southeast winds up to 10 mph. Chance of rain 20 percent.

Lanai City

Rest Of Tonight: Mostly cloudy late in the evening then becoming partly cloudy. Scattered showers late in the evening, then isolated showers after midnight. Lows around 62. Light winds. Chance of rain 40 percent.

Monday: Sunny. Highs 71 to 78. Light winds.

Monday Night: Partly cloudy. Isolated showers in the evening. Lows around 62. Northeast winds up to 10 mph. Chance of rain 20 percent.

Kaunakakai

Rest Of Tonight: Partly cloudy with isolated showers. Lows 53 to 70. Light winds. Chance of rain 20 percent.

Monday: Mostly sunny. Isolated showers in the afternoon. Highs 67 to 83. Light winds becoming east up to 10 mph in the afternoon. Chance of rain 20 percent.

Monday Night: Partly cloudy with isolated showers. Lows 54 to 70. East winds up to 10 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Light to occasionally moderate east to southeasterly winds are expected to continue through most of the week and into next weekend, with only slight variations in speed and direction. In this flow, clouds and showers will favor windward areas overnight and leeward and interior areas in the afternoon where sea breezes develop. Overall, shower activity will be limited. However, moisture from a front expected to stall just north of Kauai may bring an up tick in shower to the western end of the state tonight into tomorrow and an upper level disturbance may bring another uptick in showers midweek.

Discussion

This evening satellite imagery shows clouds clearing over the island chain as land breezes have developed. The exception is Kauai and windward Big Island. Rainfall totals range between .75 and .20 inches for the rainier areas of Kauai and between .06 and .16 inches for southeast windward Big Island for the past 12 hours. Expect clouds to continue to clear overhead as land breezes take over the rest of the night over Oahu and Maui.
An approaching cold front will near Kauai with light northerly winds running ahead of the front, creating a convergent zone over Kauai tonight. Latest guidance shows less chance of this zone reaching Oahu so eased the chances of rain overnight. Light southeasterly flow will prevail elsewhere, keeping clouds and showers focused along windward Big Island and a rain shadow elsewhere. Sea breezes will develop in the afternoon Monday, allowing cloud buildups and a few showers to leeward and interior areas during the day. Overall, shower activity will be limited as mid- level ridging tries to build overhead, increasing atmospheric stability, and drier air continues to filter in from the east.
This pattern is expected to persist through most of the week and into next weekend as a progressive pattern to the north keeps the surface ridge relegated south of its usual position and light to moderate east to southeasterly winds persist across the state. A possible deviation from this pattern may occur Tuesday into Wednesday as a perturbation in the flow aloft moves overhead and increases atmospheric instability, which may lead to a slight uptick in shower activity as pockets of moisture move in on the east to southeasterly flow. Then models show reasonable agreement on mid- level ridging building back overhead for the latter part of the week and into the weekend, which will help to suppress shower activity once again.

Aviation

A cold front passing north of the area will lead to light east- southeast flow through Monday. Thus, expect weak drainage winds tonight and the development sea breezes along coastal regions by Monday afternoon.
Isolated light showers will affect mainly windward areas tonight. Isolated showers should shift towards interior regions Monday afternoon with the development of the sea breezes.
No AIRMETS are currently in effect.

Marine

Winds have weakened and shifted east southeasterly as a weak front continues to approach from the northwest. This front is expected to stall just north of Kauai later tonight into Monday, which should keep the light east southeast flow in place. Winds will increase slightly and veer out of the southeast across much of the island chain through Tuesday night, in response to low pressure forecast to develop far northwest of the state. Light to moderate east southeast or southeast flow will persist through the remainder of the week.
A large long-period northwest (305-325 degrees) swell has filled in across the local waters, slightly higher than guidance, as reflected in the nearshore buoy observations. The High Surf Advisory (HSA) has thus been upgraded to a High Surf Warning for most north and west facing shores of the smaller islands through Monday afternoon. A HSA will likely be issued for west facing shores of the Big Island in morning package. In addition, a Small Craft Advisory (SCA) continues for exposed waters due to combined seas exceeding 10 feet. The swell will gradually ease Tuesday through midweek as it shifts out of the north.
Choppy east shore surf, below seasonal averages, will remain low through the rest of this week as wind speeds remain on the lighter side. South shore surf will remain seasonably small, though a small bump is possible around midweek.

HFO Watches/Warnings/Advisories

High Surf Warning until 6 PM HST Monday for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Maui Windward West, Kauai North, Molokai Windward, Molokai North, Molokai West, Maui Central Valley North, Windward Haleakala.
Small Craft Advisory until 6 PM HST Monday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Kaiwi Channel, Maui County Windward Waters.

Data Courtesy of NOAA.gov