Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
559 FXHW60 PHFO 191908 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 908 AM HST Wed Jun 19 2024 .SYNOPSIS... Persistent high pressure far north of the islands will support locally strong trade winds through the weekend. Brief, passing showers will favor windward areas, especially during nights and mornings, with a few sprinkles occasionally spreading leeward. && .DISCUSSION... Benign trade wind weather continues through the forecast period. The inversion on this morning`s soundings is anchored around 6kft and noticeably sharper than yesterday`s. At the surface, this is translating into stable low clouds that are delivering limited showers to windward and mauka zones. Little change expected during the next 24 hours as highly stable and breezy trades persist. Thereafter, trades get a modest boost as the pressure gradient strengthens over the forecast area with locally strong trade winds then continuing into the weekend. At the same time, upstream moisture embedded within the prevailing trade wind pattern will arrive late Thursday night marking the onset of a somewhat wetter trade wind pattern. An upper low parked over the area will slowly drift westward funneling periodic high clouds into the area for the next several days. && .AVIATION... Trades will gradually strengthen to become breezy to locally windy today, with light showers and low ceilings favoring windward and mauka locations. Periods of MVFR conditions are possible in any showers, which are expected to increase slightly in coverage during the late night to early morning hours. AIRMET Tango is in effect for low level turbulence lee of mountains due to the strengthening trade winds. AIRMET Sierra is in effect for windward sections of the Big Island through this morning. Otherwise and elsehwere, VFR conditions should prevail. && .MARINE... Fresh to strong trade winds will increase Thursday and Friday as surface high pressure to the north-northeast strengthens and settles about 800 nm north of the islands. A Small Craft Advisory (SCA) remains in effect for most waters around the Big Island and Maui County and will expand to most waters as the trade winds increase. Fresh to near-gale winds will hold through the weekend and likely into early next week. Expect diminished south shore surf through Friday. A mix of a small, long-period south swell and a shorter period southeast swell may push shores up near seasonal average during the weekend. As these swells slowly decline early next week, another small, long-period south-southwest swell is expected to fill in. Surf along east-facing shores will gradually trend up during the weekend. The trade wind swell is currently at 6 to 7 feet at 7 to 8 seconds and will rise slightly with the increased trade winds to around seasonal average this weekend. Surf along north facing shores will be at seasonally tiny levels through much of the week. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 PM HST Thursday for Kaiwi Channel- Maui County Windward Waters-Maalaea Bay-Pailolo Channel- Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...JVC AVIATION...Bedal MARINE...Wroe