000 FXHW60 PHFO 090200 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 400 PM HST Wed Feb 8 2023 .SYNOPSIS... Strong winds that are being observed statewide today will continue through Friday as strong surface high pressure passes north of the island chain. Wind speeds will slowly ease this weekend as the ridge to the north weakens slightly, but remain locally strong through early next week. Showers will mainly focus along windward and mountain areas through the forecast period, with brief showers spreading to leeward areas at times. && .DISCUSSION... This afternoon, strong surface high pressure is continuing to strengthen behind a frontal boundary located roughly 300 nm north of Kauai. The result across the island chain has been strong, gusty winds increasing throughout the day. Surface observations this afternoon are reporting many locations with sustained winds above 30 mph, hitting Wind Advisory criteria across the island chain. The strongest winds observed today have been across northern portions of the Big Island, particularly around the Kohala Mountains where gusts in excess of 58 mph have been reported for the past couple of hours. Based on the latest observations and updated hi-res guidance, the previously issued Wind Advisory for zones including the Kohala Mountains and the Kamuela area of the Big Island has been upgraded to a High Wind Warning. Additionally, the Wind Advisory was expanded to include southern portions of the Puna District near Volcano, where winds in excess of 30 kts will also be possible. As winds aloft continue to increase under ridging aloft tonight through Friday, winds on the summits of Maui and the Big Island will likely reach advisory levels as well beginning this evening. A generally drier air mass will settle over the region as the trade winds increase through Friday, which would suggest a general decrease in shower activity over the next couple of days. However, this rainfall forecast becomes a bit complex since the strong trades will also enhance orographic lift, allowing any lingering low-level moisture to produce windward showers that could also occasionally blow into leeward areas at times. Additionally, hi-res models also suggest that a short-lived modest increase in moisture is possible early Thursday morning from Maui to the Big Island, further enhancing windward showers for a brief time across these areas. Minor adjustments to timing and location of rain chances have been made with this afternoon's forecast updates. The surface ridge north of the state will begin to weaken this weekend, allowing trades to drop off a bit but remain breezy. Showers will continue to favor windward locations, though troughing and an eventual low aloft over and east of the islands may increase instability and enhance trade wind showers through the weekend and into early next week. && .AVIATION... Strong trade winds will remain through tomorrow, continuing the need for an AIRMET Tango for tempo moderate and isolated severe low-level turbulence over and downwind of island terrain. Moisture in the trade wind flow will lead to passing showers over windward areas tonight and Thursday morning. Brief MVFR ceilings and visibility may occur near passing showers, but otherwise VFR conditions are expected to prevail across the area into Thursday. && .MARINE... Strong- to locally gale-force easterly trade winds will continue for the next couple of days as high pressure passes to the north tonight and builds Thursday. A Gale warning is in effect for the typically windier waters and channels from Maui County to the Big Island beginning today through Friday afternoon. We will continue to monitor chances of gales developing in the Kaiwi Channel tonight, but looks more likely Thursday. Seas have exceeded the 10 foot Small Craft Advisory (SCA) thresholds at Mokapu Point and Hilo PacIOOS buoys and are excepted to continue to build over the next couple of days. A SCA is in effect for all remaining waters due to high seas and strong winds through Friday afternoon. Although winds and seas should drop slightly over the weekend as the high weakens briefly and moves further northeast, rough boating conditions will continue. Surf along north and west facing shores will drop a notch tonight. A fresh north- northwest swell will arrive Thursday and build down the island chain. If this source comes in higher than expected locally, expect surf heights to reach advisory levels for exposed north and west facing shores as it peaks late Thursday. This swell will hold into Friday, then quickly subside over the weekend. A small, long- period northwest swell is expected to fill in through the day Saturday and linger through Sunday. A slightly larger northwest swell will fill in early next week. Large fetch area upstream of the islands, generated by strong persistent trade winds, will produce advisory level surf along east facing shores tonight through Friday. Surf heights are expected to peak Friday, possibly near warning levels, before slowly trending down over the weekend as trades ease. && .HFO WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 6 PM HST Friday for Kohala-Big Island North. Wind Advisory until 6 PM HST Friday for most islands except the Kona District of the Big Island. Wind Advisory from 6 PM HST this evening until 6 PM HST Friday for Haleakala Summit-Big Island Summits. High Surf Advisory until 6 AM HST Saturday for Olomana-Maui Windward West-Kauai East-Koolau Windward-Molokai Windward- Molokai North-Maui Central Valley North-Windward Haleakala-Big Island East-Big Island North. Small Craft Advisory until 6 PM HST Friday for Kauai Northwest Waters-Kauai Windward Waters-Kauai Leeward Waters-Kauai Channel- Oahu Windward Waters-Oahu Leeward Waters-Kaiwi Channel-Maui County Windward Waters-Maui County Leeward Waters-Big Island Windward Waters. Gale Warning until 6 PM HST Friday for Maalaea Bay-Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Vaughan AVIATION...Foster/Tsamous MARINE...Almanza