847 FXHW60 PHFO 071342 CCA AFDHFO Area Forecast Discussion...CORRECTED National Weather Service Honolulu HI 342 AM HST Tue Jan 7 2020 .SYNOPSIS... Strong and gusty trade winds will continue through the week. Showers will focus over windward areas with some reaching leeward locations of the smaller islands. Wetter weather is likely during the second half of the week as a low aloft moves near the islands. && .DISCUSSION... A strong high pressure remains parked far northeast of the state with a current pressure near 1035 mb. The high will continue to bring strong trade winds through the week as it moves to a position north of the state and strengthens to near 1040 mb. A High Wind Warning is in effect for the Kohala Districts of the Big Island and a Wind Advisory is in effect for parts of lower elevations of Maui county and the Big Island of Hawaii through Wednesday evening. There is also an Wind Advisory in effect for the summits of Mauna Loa and Mauna Kea. Strong winds will continue through the week and these advisory/warning products will be updated as necessary. Scattered showers can be found racing westward across the windward waters and windward island locations. Cloud tops are higher than our normal 8-10 thousand feet with current tops reaching 15 to 20 thousand feet with isolated pockets reaching 25 thousand feet. An upper level low centered east of the state is providing the instability for the higher tops. The overnight Hilo sounding measured a 500mb temperature of -11.5 Celsius which indicates slight to moderate instability. Global models show some colder 500 mb temps farther east of the state in the vicinity of the upper low. The low is forecast to meander east of the area through Wednesday before moving westward toward the state. The current forecast brings in the effects of the upper low to the eastern half of the state Wednesday night, and the rest of the state Thursday and Thursday night. Increasing shower coverage and intensity is expected with the possibility of isolated thunderstorms accompanying the heaviest showers. && .AVIATION... A strong high pressure system north to northeast of the Hawaiian Islands will produce breezy to windy trade winds through the week. Winds this strong will produce low level moderate turbulence along and south through west of mountain ranges on all islands. An upper level low lingering just east of the island chain will continue to produce bands of showers spreading westward in the trade wind flow mainly during the overnight and early morning hours. Periods of mountain obscurations are possible for north though east sections of each island. Upper level winds around this low are strong enough for moderate turbulence aloft between FL250-350 across all islands. AIRMET Sierra remains in effect for tempo mountain obscurations along north through east facing sections Kauai, Oahu, Molokai, Maui and the Big Island. This AIRMET will decrease in coverage after 18Z this morning. AIRMET Tango remains in effect for tempo moderate turbulence below 090 over and south through west of mountains. Another AIRMET Tango remains in effect for moderate upper level turbulence due to strong winds aloft. These turbulence AIRMETs will likely continue through at least the next 24 hours. AIRMET Tango for strong surface winds greater than 30 KTS also remains in effect. && .MARINE... Strong high pressure will prevail to the NE of the islands for the foreseeable future, producing strong to near gale force winds near and upstream of the islands. Where winds are most accelerated by island terrain, they are reaching gale force over some marine zones. See the Marine Weather Message (MWWHFO) for details on the ongoing Gale Warning and Small Craft Advisory. A High Surf Advisory is in effect for E facing shores of most islands, and the rough and choppy high surf will persist into the weekend. Short-period seas are forecast to build through the week (to near 15 feet or more) in response to the persistent upstream fetch of trade winds, and surf along E facing shores could approach warning levels as early as tomorrow, but more likely Thursday into Friday. See the Coastal Hazard Message (CFWHFO) and the Oahu Surf Discussion (SRDHFO) for additional information. The combination of high surf, strong onshore winds and elevated ocean water levels will result in beach erosion and wave runup along E facing shores later in the week, when full moon high tides coincide with the elevated surf. Little in the way of significant swell is otherwise expected, with only a small northwest swell anticipated through Wednesday. A moderate long-period northwest swell arriving Friday could produce surf close to advisory levels into Saturday. A smaller northwest swell may arrive Sunday into Monday. && .HFO WATCHES/WARNINGS/ADVISORIES... High Surf Advisory until 6 PM HST Friday for Kauai Windward-Oahu Koolau-Olomana-Molokai Windward-Maui Windward West-Windward Haleakala-South Big Island-Big Island North and East. Wind Advisory until 6 PM HST Wednesday for Lanai-Kahoolawe-Maui Central Valley-South Big Island-Big Island Interior-Big Island Summits. High Wind Warning until 6 PM HST Wednesday for Big Island North and East-Kohala. Gale Warning until 6 PM HST Wednesday for Maalaea Bay-Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. 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. && $$ DISCUSSION...Morrison AVIATION...Bohlin MARINE...Birchard