Surface high pressure continues to strengthen northeast of the state tonight and will bring an increase in trade wind flow. Low clouds and showers will remain through Monday morning mainly over portions of Maui, Molokai, and Oahu as an area of enhanced moisture moves in from the east. From late Monday through Friday, light easterly winds will return. Afternoon coastal sea breezes should help bing clouds and showers to interior and mountainous locations. From Wednesday onward, deeper moisture moving in from the southeast should bring increased precipitation chances to the Big Island, and perhaps Maui.
Light, stable trades continue through the evening hours, occasionally light enough for land breezes to develop. Low-level moisture embedded within these trades may lead in light shower activity resulting in periodic localized MVFR conditions, namely for Maui County. Trades increase slightly by the early morning, becoming light to moderate, with clouds and showers along windward and mauka areas at times. Otherwise, VFR conditions prevail.
AIRMET Sierra is in effect for mountain obscuration across windward Oahu and Maui County due to the aforementioned light shower activity. This is expected to improve this evening, however.
A sharp, though weak, upper level trough is producing moderate turbulence aloft over the Big Island, where AIRMET Tango is in place above FL300. This is also expected to subside by this evening.
Moderate trade winds tomorrow will become light to moderate through the week as high pressure weakens.
A large long-period south-southwest (200 degree) swell will hold tonight into Monday before gradually declining through the rest of the week. Buoy 51002 readings remain steady around 4 to 6 feet at 17 to 19 seconds and the size at the webcams looks around borderline at warning levels (15 foot sets) currently with some lulls in between sets. Seeing that these large sets seem to be a bit inconsistent, there is a chance that the High Surf Warning could be downgraded to an advisory if the buoy levels drop significantly tonight. One thing to note is that as the period drops tonight and tomorrow, the consistency of the sets could increase. The large south- southwest swell combined with King Tides will continue to create the potential for significant wave run up along south and west facing shores through Monday afternoon.
Very little swell energy is arriving along north facing shores, keeping surf tiny to flat. A small bump in surf is possible for north- facing shores by late Tuesday into Wednesday with the arrival of a small northwest swell and a smaller north swell. Gentle to moderate east-northeasterly winds expected through next week will keep surf along east facing shores below seasonal average.
A Coastal Flood Statement remains in effect for minor coastal flooding of vulnerable low-lying coastal roadways, docks, boat ramps and other coastal infrastructure. King Tides combined with water levels that are running higher than predicted will lead to minor flooding potential around the daily peak tide, which will be during the late afternoon and early evening hours, through at least Tuesday. While minor coastal flooding is expected along all shorelines, the combination of the south-southwest swell, King Tides and the daily high tide will make low-lying coastal areas along south and west shores susceptible to more widespread coastal flooding through the first half of next week.
A Marine Weather Statement also remains in effect due to the large long-period south-southwest swell producing harbor surges and breaking waves near harbor entrances along south and west facing harbors.
High Surf Warning until 6 AM HST Tuesday for Big Island South- Big Island Southeast-East Honolulu-Ewa Plain-Honolulu Metro- Kahoolawe-Kauai South-Kauai Southwest-Kipahulu-Kohala-Kona-Lanai Leeward-Lanai South-Maui Central Valley South-Maui Leeward West- Molokai Leeward South-Molokai Southeast-Niihau-South Haleakala- South Maui/Upcountry-Waianae Coast.
