992 FXHW60 PHFO 121333 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 333 AM HST Thu Jun 12 2025 .SYNOPSIS... Breezy trades become locally strong this weekend into next week delivering limited clouds and showers mainly to windward and mauka areas. && .DISCUSSION... Surface high pressure northeast of the state is maintaining moderate to locally strong trades. Satellite and radar imagery show numerous clouds moving westward within the tradewind flow with embedded light to moderate scattered showers focusing mainly along windward and mauka areas. This area of enhanced showers should persist through the morning hours and then dry out in the afternoon. This pattern will repeat again tonight into early Friday morning but may be a little wetter, especially for the Western half of the state as the upper level low opens to a trough and slowly sags southeastward and low level moisture remains slightly above normal. Aloft, the resident subtropical jet funnels high clouds across area skies. The upper level trough is expected to move directly over the islands this weekend and form into a weak upper level low which will produce some instability across the state. At the same time a surface high will develop north of the state, strengthening tradewind flow across the state. This would generally equate to enhance showers but one limiting factor may be available moisture as drier air filters in from the east within the tradewind flow. Thus, seasonably dry trades could persist this weekend into next week. The best opportunity for showers will be windward/mauka zones mainly overnight. && .AVIATION... A stable, moderate to locally breezy trade wind flow will persist for the next couple of days. Periods of MVFR ceiling and visibility in SHRA will focused along windward slopes especially during the overnight and early morning hours. AIRMET SIERRA has been issued for MTN OBSC due to clouds and showers building along windward slopes and will likely continue through the morning hours. VFR will dominate over most leeward areas, but sheltered terrain will experience isolated MVFR conditions each afternoon, especially on the Kona slopes of the Big Island. The stable trade wind flow will produce light turbulence below 7,000 feet, but these condition should not require SIGMET Tango through today. An upper-level low to the west will send high clouds over the state and may produce some light turbulence above FL300. && .MARINE... High pressure far northeast of the islands will remain nearly stationary through the remainder of this week and bring moderate to locally strong trade winds. Another area of high pressure will then build north of the region this weekend and help to further strengthen trades. Thus, a Small Craft Advisory for the windier waters and channels around Maui County and the Big Island remains in effect through at least Sunday. Surf along south facing shores will be tiny, well below average, over the next several days. A small, long period, south swell originating from a fetch near New Zealand will build late this weekend and help to boost surf heights through early next week. There will be choppy surf along east facing shores through the forecast period due to the moderate trades. Expect tiny surf along north facing shores, which is typical for this time of year. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 PM HST Sunday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Almanza AVIATION...Almanza MARINE...Thomas