Marine Weather and Tide Forecast for Launiupoko, HI

DISCUSSION
A 1012 mb surface low is centered 850 miles northwest of Kauai, while a 1029 mb high is centered around 1500 miles north northeast of Honolulu. Between these two features lies a band of thunderstorms along a trough of low pressure stemming from the low, which passes around 150 miles northwest of Kauai. Visible satellite shows thin cirrus clouds tracking across the main Hawaiian Islands. At the low levels, moderate southeast flow across the state are pushing a few clouds with isolated showers onto windward and southeast slopes, but overall mostly dry conditions expected through night. A slight chance of thunderstorms possible tonight for waters north and west of Kauai along the eastern fringes of the trough, but stability is expected to increase this weekend.

The surface low will shift eastward this weekend, then dampen into a trough over the islands early next week. This will ease the east-southeast flow allowing for daytime sea breezes and nighttime land breezes to become dominant across the state this weekend through the middle of next week. Low clouds and showers will favor leeward and interior sections in the afternoon and evening hours, and east and southeast facing slopes and coasts overnight and during the morning hours, with most showers over the coastal waters or near the immediate coast overnight. A disturbance aloft diving southward over the state could bring locally heavy rainfall to portions of the island chain Tuesday into Wednesday.

The trough will then fizzle out with a gradual return and strengthening of the trade winds across the state for the second half of next week featuring mainly windward and mauka showers.

AVIATION
Light winds with a background southeasterly flow will continue to persist through Saturday. Winds will be light enough for localized land breezes to develop tonight and sea breezes during the day Saturday. Clouds and scattered showers may produce brief MVFR conditions tonight. A strong upper level jet passing just south of the state will produce a stream of high clouds and moderate upper level turbulence across the entire state through tonight and possibly into Saturday. AIRMET TANGO is in effect for moderate turbulence between FL280 and FL400.

MARINE
Locally fresh southeast winds will gradually ease and become light and variable over the weekend as low pressure northwest of the Islands slowly weakens and shifts northward. Light flow will continue into Monday and Tuesday. Trade winds will eventually return midweek. A slight chance of thunderstorms remains northwest of Kauai through late tonight.

Existing small northwest swell will continue to fade, but a new slightly larger long-period northwest swell is forecast to build in overnight, peak Saturday night or Sunday, then fade through early next week. Surf along north and west facing shores is expected to remain small for the coming week.

Multiple small early season south swells will maintain small background southerly energy into the coming week. Weak upstream trade wind flow will keep surf along east facing shores near or below seasonal averages.



HFO WATCHES/WARNINGS/ADVISORIES
None.