Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
986 FXHW60 PHFO 010653 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 853 PM HST Sun Jun 30 2024 .SYNOPSIS... Gentle to moderate trade winds will continue through the overnight hours. Trade wind speeds will trend higher into the moderate to breezy range on Monday as the ridge builds into the Hawaii Region. Clouds and brief passing showers will favor windward and mountain areas. && .DISCUSSION... An upper level low shown on satellite water vapor imagery is roughly 300 miles north of the island of Kauai will weaken as it lifts northward over the next 24 hours. Weaker winds and lingering instability with this low will change as the low departs the region. By Monday the high pressure ridge north of the islands will build in, producing more stable conditions with less cloud and shower trends, and an increase in the trade wind speeds into the moderate to breezy range through the week. Expect limited showers for most windward areas with lower shower activity over the drier leeward regions. Trade wind thermal inversion heights will range from around 5,000 to 6,500 feet in most locations in a fairly stable weather pattern. Some exceptions may include the eastern slopes of Maui and the Big Island where periods of passing showers will likely continue. && .AVIATION... Moderate to locally breezy trades will continue through Monday. Some brief MVFR cigs/vsbys will be possible in windward areas, particularly over the Big Island tonight into early Monday. Otherwise, VFR conditions are expected to prevail. No AIRMETs are currently in effect. && .MARINE... High pressure north of the state will maintain moderate to fresh trade winds tonight. The trades are expected to strengthen back to fresh to strong levels on Monday and persist through most of the week. A Small Craft Advisory will likely be needed for the typical windy areas on Monday into Tuesday. Trades may weaken slightly on Wednesday, before a slight uptick of the trades on Thursday. No significant south swells are expected through this upcoming week. However, a series of small south-southwest and southeast swells will keep south facing shores from going flat. Typical mostly flat summertime conditions will continue along north facing shores through most of the week. East shore surf will gradually trend up closer to seasonal levels Monday through the middle of this as the trades strengthen over and upstream of the islands. A fetch of strong northeast winds well off the California coast should bring a small northeast (050 to 060 degree) swell late this weekend into early next week. Some of this swell should wrap into select north facing exposures as well. Water levels running roughly 0.5 ft higher than normal around the Big Island combined with the new moon tides could cause minor flooding issues between July 2nd and July 6th with peak water levels expected on July 4th. Our last full moon, we did receive reports of some areas of the coastline becoming inundated with the high tide such as Coconut Island and Puhi Bay. A Coastal Flood Statement will likely be needed for the Big Island near the 4th of July. For the other islands, water levels are running just a touch above normal and will likely not reach our criteria of 1 foot above the Mean Higher High Water (MHHW). && .HFO WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Bohlin AVIATION...Jelsema MARINE...JT