A surface ridge will maintain light winds, with land and sea breezes in most areas through tonight. A weakening front will increase showers late tonight across Kauai, with the showers spreading southeastward to the other islands Friday through Saturday. Moderate to breezy north to northeast winds will build behind the front. Another stronger front is forecast to approach later in the weekend, bringing breezy southwesterly winds late Sunday through Monday. A band of heavier showers is expected to accompany the front as it moves through the islands late Monday through Tuesday, followed by breezy northwesterly winds.
Currently at the surface, a 1028 mb high is centered to the distant northeast, with a ridge axis extending southwestward into the eastern half of the state. Meanwhile, a weakening cold front is located approximately 70 miles northwest of Kauai. Light winds prevail across the state this afternoon with daytime sea breezes across most locations. Satellite imagery continues to show a band of clouds and showers over Oahu and portions of Maui County, with afternoon clouds over the interiors of Kauai and the Big Island.
Guidance continues to show the ridge of high pressure slowly shifting southeastward tonight as the weakening cold front approaches from the northwest. Some deeper moisture is expected to move in ahead of the front and allow for the development of a few more showers across Kauai this evening, but rainfall amounts should be minimal. Otherwise, expect land breezes to develop across the rest of the state tonight allowing any lingering clouds and showers to clear.
Guidance remains in good agreement showing a weak cold front moving into Kauai after midnight tonight, then decaying as it shifts southeastward through Oahu and into Maui County on Friday, before stalling out and gradually dissipating in the vicinity of Maui and the Big Island Friday night and Saturday. The front will bring an increase in clouds and showers as it moves through, followed by a period of moderate to breezy north to northeast winds. The best forcing will remain well to the north of the state as the front moves through, so we don't anticipate any significant rainfall or flooding concerns with this feature.
The remnant moisture from the old front is expected to gradually lift back north of the islands Saturday night and Sunday, as yet another front approaches from the northwest. This front appears stronger, with moderate to breezy southwesterly winds developing in advance of the feature late Sunday through Monday. The front appears to move through the state late Monday through Tuesday, accompanied by a line of heavier showers with potentially gusty winds, followed by breezy northwesterly winds.
Pre-frontal convergence low clouds and isolated showers expected across Oahu and Maui County this afternoon. AIRMET Sierra is posted for tempo mountain obscurations above 3000 feet across of Oahu, Maui, Molokai and Lanai. Sea breezes will switch to land breezes tonight and clear the cloud cover out over the islands, with AIRMET Sierra ending around this time.
An incoming weak front from the northwest will approach this evening and is expected to bring an increase in showers over Kauai late tonight and spread southeastward Friday. MVFR and lower ceilings are expected along the front over windward and northern slopes as the front moves towards Maui and stalls. North winds will build tonight along the front and veer northeast by Friday afternoon.
A band of low level clouds and showers associated with a weak front just north of the coastal waters will move southeast over the island chain tonight before dissipating over the eastern half of the state Friday. Light and variable winds will be replaced by moderate to fresh northerly to northeasterly winds in the wake of the front as it passes each island. Light and variable winds return to Hawaiian waters Saturday night and early Sunday, with moderate to locally strong southwesterly winds developing ahead of the next cold frontal system approaching from the northwest late Sunday through Monday. This next cold front will move down the island chain from late Monday night through Tuesday, increasing chances for showers. Fresh to locally strong northwesterly winds will build in behind the front as it passes.
Offshore buoys show a large northwest swell still filling in and will peak locally tonight into the early morning hours Friday. Expect surf height to peak at High Surf Advisory levels along north and west facing shores of Niihau, Kauai and Oahu overnight and early Friday morning. Seas will also rise above 10 feet, thus a Small Craft Advisory (SCA) around most Kauai and Oahu waters remains in effect. A slightly bigger, and longer period northwest (300-320 degree) swell is expected to overlap Friday. This second swell is expected to peak Friday afternoon and evening, pushing surf heights above warning levels into Saturday for select north and west facing shores. In addition the SCA will also expand to most coastal waters with this next swell. The large northwest swells will decline Saturday into early next week. A potentially extra large northwest (310-330 degree) swell may fill in from Tuesday onward next week.
A Coastal Flood Statement has been issued for low-lying shoreline and roadways due to the combination of large surf and higher than predicted water through Monday afternoon.
Surf along east-facing shores will remain small due to the lack of trades locally and upstream of the state.
Surf along south-facing shores remain small.
High Surf Advisory until 6 PM HST Friday for Niihau-Kauai Leeward-Waianae Coast-Oahu North Shore-Kauai North.
Small Craft Advisory until 6 PM HST Friday for Kauai Northwest Waters-Kauai Windward Waters-Kauai Leeward Waters-Kauai Channel- Oahu Windward Waters.
