Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
242 FXHW60 PHFO 101943 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 943 AM HST Mon Jun 10 2024 .SYNOPSIS... Moderate to breezy trade winds will persist through the week as broad high pressure remains north of the state. Stable conditions will focus limited showers over windward areas, and leeward areas will be rather dry, though leeward Big Island will experience clouds and showers each afternoon and evening. && .DISCUSSION... A breezy and stable trade wind flow is producing a somewhat typical June weather pattern this morning. A 1029 mb surface high centered over 1,300 miles northwest of Kauai is driving the trades, and a mid-level ridge is maintaining an inversion based between 5,000 and 7,000 ft. Shallow moisture in the trade wind flow will produce modest showers over windward Big Island and Maui today, while rainfall chances were lowered over Molokai, Oahu, and Kauai due a lack of moisture immediately upstream of those islands. Leeward areas will be mostly dry, with the exception of afternoon and evening clouds and spotty showers over the Kona Districts of the Big Island. Little change is expected through the week. The surface high will move eastward during the next several days and settle far northeast of the state by Saturday. A surface ridge trailing the high will remain north of the islands, but it may be weakened enough for us to experience a subtle decrease in trade winds for Friday into the weekend. Persistent mid-level ridging over the state will maintain a stable pattern of mainly windward rainfall. Aside from afternoon showers on the Kona slopes of the Big Island, somewhat dry weather will persist for leeward areas. Random pockets of shallow moisture moving along the trade wind flow will periodically boost windward rainfall, and one such area is expected Tuesday night and Wednesday. && .AVIATION... Breezy and dry trades will deliver clouds and limited showers to windward and mauka zones through the period. Pockets of MVFR have been observed along the Big Island`s windward coast this morning, but will mix upslope as the day progresses. Otherwise, VFR prevails. AIRMET Tango for lee turb may be needed later this morning or this afternoon. && .MARINE... Fresh to strong easterly trades will continue through much of the week, as a surface high strengthens to the north. Guidance suggests winds easing slightly over the weekend as the shifts far northeast of the state and weakens. Surf along south-facing shores will hold around the advisory level through tonight due to a long-period south-southwest swell moving through. Offshore buoys remain elevated this morning with the peak energy holding steady in the 15 to 17 second bands. As a result, the advisory has been extended through tonight. A downward trend is anticipated Tuesday through midweek, with mainly a mix of the fading south-southwest swell and a small, medium- period southeast swell. A similar long- period south swell is expected to arrive Thursday night into Friday and peak late Friday into Saturday. Surf along north-facing shores will remain up slightly through the first half of the week as small north to north-northwest pulses move through. The next north pulse should fill in today, with a small north-northwest swell arriving Tuesday into midweek. A return to summertime/flat conditions is likely later this week through next weekend. Choppy surf along east-facing shores will persist the next couple of days with an upward trend later this week as the trades become more established locally and upstream across the eastern Pacific. && .HFO WATCHES/WARNINGS/ADVISORIES... High Surf Advisory until 6 AM HST Tuesday for Niihau-Kauai Leeward-Waianae Coast-Kahoolawe-Maui Leeward West-Kona-Kauai South-East Honolulu-Honolulu Metro-Ewa Plain-Molokai West- Molokai Leeward South-Lanai Leeward-Lanai South-Maui Central Valley South-South Maui/Upcountry-South Haleakala-Big Island South-Big Island Southeast. Small Craft Advisory until 6 PM HST Tuesday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Wroe AVIATION...JVC MARINE...Almanza