Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
592 FXHW60 PHFO 271343 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 343 AM HST Fri Jun 27 2025 .SYNOPSIS... Ridge of high pressure will persist north of the state maintaining breezy trades. Occasional pockets of moisture embedded within the trades will mainly focus clouds and showers over windward and mauka areas for the next several days, especially overnight. Trade wind speeds could decrease early next week as a weak front approaches from the far northwest. && .DISCUSSION... A broad ridge of high pressure north of the main Hawaiian Islands continues to drive locally breezy easterly trade winds across the state. An upper jet continues to stream a thin layer of cirrus across the state and should shift north through the day. This morning satellite and radar imagery shows low level scattered clouds and showers mainly focused along windward and mauka areas. Rain gauge networks show that most locations have received very little or no rainfall overnight, except for some windward and mauka locations on Kauai. Observed 12Z soundings at Hilo and Lihue continues to show strong inversions between roughly 6,500 and 7,500 feet, with ample dry air aloft. The Kona slopes of the Big Island have cleared out over and but will likely see afternoon sea- breezes increases cloud and shower coverage. Global forecast models remain in good agreement that the broad ridge of high pressure north of the state will remain nearly stationary through Saturday as it experiences minor fluctuations in intensity. This will maintain moderate to breezy trade winds across the main Hawaiian Islands into the weekend. Mid level ridging will keep an overall dry and stable airmass over the state, though pockets of low- level moisture trapped beneath the inversion will result in occasional windward and mauka showers, particularly during the overnight through early morning hours each day. During the second half of the weekend and into early next week, the surface ridge will weaken and shift eastward as a front makes its way across the North Pacific and a new high develops far north- northwest of the state. As this occurs, trades will likely weaken a bit more and veer to become more east- southeasterly through mid-week. Showers are expected to be fairly limited throughout this time, mainly favoring windward and mauka areas during the overnight through early morning hours each day. The western half of the state may have a better chance of showers due to the proximity of the front and associated band of moisture. The second half of next week could see a slight up tick in windward and mauka showers as equatorial moisture is advected northward in the low to mid levels from a weak inverted trough moving from east to west across the state. && .AVIATION... AIRMET SIERRA has been issued for windward and mauka areas as clouds and showers have increase early this morning producing some MVFR conditions along windward and mauka areas. Conditions could improve this afternoon. Elsewhere, VFR conditions continue under a transparent shield of cirrus clouds. AIRMET Tango remains in effect for low-level lee turb. && .MARINE... Moderate to locally strong trade winds expected for the next couple of days. A Small Craft Advisory is in effect for the typical windier waters and channels around Maui and the Big Island through at least 6AM Saturday. Early next week a disturbance passing to the north of the islands may slightly weaken the trades. The current south swell will continue to gradually fade to background levels through the weekend. Models show another small, long period south swell arriving Sunday into early next week that should boost south shore surf up to near average surf. Surf along east shores will remain rough and choppy for the next several days. Surf along north facing shores will remain tiny through the period. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 AM HST Saturday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Almanza AVIATION...Almanza MARINE...Walsh