Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
823 FXHW60 PHFO 150640 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 840 PM HST Thu Nov 14 2024 .SYNOPSIS... Windy trade winds will persist into the weekend. A slightly drier airmass over the islands will bring critical fire weather conditions to leeward areas Friday. Another band of moisture being carried in on the trades over the weekend will boost shower activity once again. && .DISCUSSION... Satellite derived precipitable water show the drier airmass spreading across the islands this evening, and extending more than 200 miles upstream of the islands. A lingering band of moisture over and upstream of the Big Island and Maui will continue to bring showers to the windward portions of those islands, while the rest of the state is expected to see limited clouds and showers through Friday night. A strong high pressure system to the far north of the islands will continue to produce strong trade winds over the region into the weekend. A Wind Advisory remains in effect for portions of the lower elevations of Maui County and the Big Island through Friday night. This may need to be extended into Saturday. Elevated winds on the Big Island Summits are expected to slowly diminish tonight as expected. The Wind Advisory in effect for the summits is expected to be allowed to expire by daybreak Friday. Heading into Saturday, leftover moisture from a front will be carried in on the trade wind flow, once again increasing the shower activity around the state. With the trade wind flow, expect the clouds and showers to be focused over windward and mountain areas. The GFS and ECMWF models are coming into better agreement with the handling of an upper level trough moving over the islands this weekend, which could help to enhance some of the showers moving over the islands. By the end of the weekend, the high pressure far north of the islands will begin to weaken, which will weaken the trades over the first half of the new week. Drier conditions are once again expected, with a return to more typical trade wind showers. && .AVIATION... Strong easterly trade winds will continue through Friday before decreasing slightly Friday night. Strong trade winds will periodically deliver showery low cloud cloud clusters over windward areas. Showers will also spread leeward at times. Expect, occasional periods of MVFR CIGS/VIS within passing showers. AIRMET Tango for moderate low-level turbulence over and downwind of the mountains will remain posted until further notice. The AIRMET Tango for moderate upper-level turbulence has been cancelled. No other AIRMETS are currently in effect, although AIRMET Sierra may need to be updated later tonight for mountain obscuration as conditions warrant. && .MARINE... A strong high pressure system north of the islands will remain in place for the next few days. Strong gusty trade winds are expected, peaking Friday and Saturday then slowly decreasing into the new work week a low pressure system weaken the ridge north of the state. A Gale Warning is in effect through Saturday for the windier waters and channels around Maui and the Big Island. A Small Craft Advisory is also in effect for all remaining coastal waters for the same time frame. This advisory may need to be extended into early next week. The current long period northerly swell will continue to trend downward through Friday and into the weekend. Some minor bumps are expected from small reinforcing northwest swells. Along east facing shores a High Surf Advisory is in effect through Saturday and may need to be extended into early next week. Rough and choppy surf is expected through the weekend due to the strong trade winds. Surf heights will gradually decrease next week with decreasing wind speeds. Along south facing shores, expect surf to remain small through the forecast period. Peak monthly tides are forecasted from Nov 15th to the 18th. These high tides combined with elevated seas from strong trade winds and rising easterly seas, may increase coastal inundation impacts for vulnerable locations during morning high tides. This has prompted a Coastal Flood Statement which will be in effect during that period. && .FIRE WEATHER... A drier airmass will persist over the islands through much of Friday, which will allow late morning and afternoon relative humidity values to fall to around 45% or slightly lower. Fuels remain dry, and when combined with the windy trades that are expected to continue, a Red Flag Warning is in effect for leeward areas Friday. There is a low potential for critical fire weather conditions to continue into early Saturday afternoon, however a band of showers expected on Saturday should end fire weather concerns by Saturday evening. && .HFO WATCHES/WARNINGS/ADVISORIES... Red Flag Warning from 10 AM to 6 PM HST Friday for Niihau-Kauai South-Kauai Southwest-East Honolulu-Honolulu Metro-Ewa Plain- Waianae Coast-Oahu North Shore-Waianae Mountains-Molokai West- Molokai Leeward South-Lanai Windward-Lanai Leeward-Lanai South- Lanai Mauka-Maui Leeward West-Maui Central Valley North-Maui Central Valley South-South Maui/Upcountry-South Haleakala-Big Island South-Big Island Southeast-Kohala-Big Island Interior. High Surf Advisory until 6 AM HST Sunday for Olomana-Maui Windward West-Kauai East-Koolau Windward-Molokai Southeast- Windward Haleakala-Kipahulu-South Haleakala-Big Island Southeast- Big Island East-Big Island North. Wind Advisory until 6 AM HST Saturday for Lanai Mauka-Kahoolawe- Maui Windward West-Maui Leeward West-Kohala-Big Island Interior- Molokai North-Molokai West-Molokai Leeward South-Lanai Windward- Lanai Leeward-Maui Central Valley North-Maui Central Valley South-South Haleakala-Big Island South-Big Island Southeast-Big Island North. Wind Advisory until 6 AM HST Friday for Big Island Summits. Small Craft Advisory until 6 AM HST Sunday 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 AM HST Sunday for Maalaea Bay-Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION/FIRE WEATHER...M Ballard AVIATION...Shigesato MARINE...Bohlin/Walsh