Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
935 FXHW60 PHFO 051321 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 321 AM HST Sun May 5 2024 .SYNOPSIS... Breezy trade winds will continue into Monday and then decrease to more moderate levels from Monday afternoon into Tuesday. An upper level disturbance passing through the islands will keep enhanced showers in the forecast through Monday. An unstable band of clouds and showers will drift into the islands on the trade winds, bringing another round of wet weather for all islands from Wednesday into Thursday. && .DISCUSSION... The satellite water vapor imagery this morning shows a weakening upper level low slowly drifting eastward across the Hawaiian Islands. A subtropical jet stream is also set up over the islands. A Wind Advisory was issued this morning for the highest summits of Mauna Kea and Mauna Loa due to strong southwest winds aloft. These stronger summit winds will diminish later this evening. A 1030 mb high pressure system remains far north of the island chain and will continue to produce breezy easterly trade winds across the state into Monday. By Monday afternoon trade wind speeds transition to more moderate levels as the high pressure system drifts eastward away from the Hawaiian Islands. Expect moderate easterly trade winds to continue through the rest of the week. Wetter than normal conditions remain in the forecast for all islands through much of this week. Enhanced showers will continue into Monday as a weakening upper level disturbance drifts from west to east across the island chain. Tuesday will trend a bit drier. An unstable band of clouds and showers, remnants of an old East Pacific cold front, will drift into the islands on the trade winds producing wet weather for all islands from Wednesday into Thursday. An upper level trough sweeping in from north on Thursday and Friday will likely keep enhanced showers in the forecast into next weekend. && .AVIATION... Breezy easterly trade winds will persist into tonight, with clouds and showers favor windward and mauka locations. MVFR conditions will be possible in showers, especially across windward areas overnight through the early morning hours. Elsewhere, VFR conditions will prevail, with only spotty showers making it to leeward areas. AIRMET Sierra for tempo mountain obscuration will persist over windward portions of each island through the morning hours. AIRMET Tango is in effect for mod turb below 9000 feet downwind of island terrain. Additionally, some moderate turbulence aloft (FL280-FL350) is expected today. && .MARINE... Consolidating high pressure far north of the islands will support fresh to strong easterly trade winds into Monday, with the typical windier waters around Maui County and the Big Island approaching near- gale force speeds. A Small Craft Advisory (SCA) for all waters will remain posted through at least tonight for winds and seas greater than 10 feet. The high will move east thereafter, leading to a gradual easing to moderate to locally strong speeds by the middle of the week. The SCA may be pulled back over the first half of the week to the typical windier waters around Maui County and the Big Island by Tuesday. A disturbance aloft will allow for the development of a few heavier showers the next couple of days, producing periods of gusty winds and reduced visibility. East facing shores will continue to see rough and choppy seas for at least the next several days before declining coinciding with the weakening winds. North facing shores will decline today into Monday. A reinforcing small to moderate northwest swell will move in Monday before fading into midweek. South facing shores will continue to see consistent pulses of swell through the week as storm activity in the South Pacific ramps up. Long period forerunners have filled in overnight and will build into Sunday, with peak surf heights remaining below High Surf Advisory (HSA) heights. Reinforcing south to southwest swells filling in on Monday looks to be just below HSA. && .HFO WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 6 PM HST this evening for Big Island Summits. Small Craft Advisory until 6 AM HST Monday for all Hawaiian waters. && $$ DISCUSSION...Bohlin AVIATION...Gibbs MARINE...Shigesato