A stalled out front will persist over Maui County today, continuing to bring periods of shower activity, namely to Maui County and windward portions of the Big Island. Unsettled weather resumes this weekend as another slower-moving front meanders over the islands. Conditions improve, drying out the islands beginning early next week as a surface high builds north of the islands.
A stalled out front bisects the Hawaiian Islands along Maui County, persisting through much of the day and will continue to bring periods of shower activity to predominately Maui County and windward portions of the Big Island. Latest model guidance depicts upper-level troughing with a series of complex lows will maintain these lingering showers along the moisture axis associated with the aforementioned stalled out front over the next several days, namely across windward and mauka locations as northeastern flow prevails. Previous shift mentioned the potential for flood- related products given the development of higher rain rates, which may result in minor flooding and ponding of water on roadways. This will need to be monitored through the remainder of the week going forward.
As the weekend approaches, model guidance of the GFS and ECMWF supports a relatively active weather pattern with periods of shower activity for the islands. Northeastern flow will begin to veer southeasterly during this time in response to the next, slower-moving frontal boundary approaching the islands from the northwest associated with a deep low well north of the islands meandering toward the Gulf of Alaska. Model total precipitable water (PWATs) connected with this next frontal boundary are on the range of 2 to 3 standard deviations higher than average. Increasing instability aloft combined with deep moisture pooling northward across the islands associated with the aforementioned system will sustain a wet pattern through the weekend.
By early next week, conditions will begin to improve as the frontal boundary exits to the east and a drier airmass fills the void as a surface high builds just north of the islands with extensive ridging aloft.
A weak stalled out front over the eastern end of the state will continue to produce some showers mainly over windward and mauka areas today and tonight. Drier conditions are expected over the western islands of Kauai and Oahu. Some MVFR cigs/vsbys may affect windward portions of Molokai, Maui and the Big Island at times, but predominantly VFR conditions are expected statewide during the next 24 hours.
AIRMET Tango remains in effect for moderate upper level turbulence across Oahu and Maui County. Conditions should improve later this morning.
AIRMET Zulu is in effect for moderate icing in the layer from 120-FL240. This AIRMET could remain in place for much of the day.
Light to moderate northeast winds will persist into Friday across most waters as a stalled frontal boundary gradually diminishes over the eastern end of the state and high pressure builds to the north. The exception will be over the Big Island waters east of the boundary, where light east to southeast winds will prevail. Guidance indicates a progressive pattern continuing into the weekend, with a front approaching and moving through the area Sunday into Monday, followed by another front approaching by midweek. The weekend front could bring locally heavy showers to portions of the marine area, along with a period of moderate to locally fresh southwest winds.
Surf along exposed north- and west-facing shores will remain near advisory levels into Friday as overlapping west-northwest and north-northwest swells move through. Overnight offshore buoy observations reflect this mixed swell regime, with north-northwest energy in the 10–12 second range and west-northwest energy holding in the 13–15 second bands. Guidance shows these swells easing late Friday into the weekend, with a small, long-period northwest swell arriving late Saturday.
Surf along east-facing shores will remain small into next week due to the lack of persistent trade winds locally and upstream.
None.
