Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
643 FXHW60 PHFO 011345 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 345 AM HST Mon Jul 1 2024 .SYNOPSIS... A high pressure ridge north of the Hawaiian Islands will build today, increasing trade wind speeds into the moderate to breezy range. These breezy trade winds will continue through much of the week. Fairly stable conditions aloft will keep brief passing showers over windward and mountain areas, mainly in the overnight to early morning hours. && .DISCUSSION... An upper level low shown on satellite water vapor imagery is roughly 350 miles north of the island of Kauai will weaken as it lifts farther northward over the next 24 hours. Infrared satellite imagery east (upstream) of the island chain shows fairly stable clouds riding in on the trade winds. These passing stable clouds will not produce much rainfall over the islands in the short term. Starting today the high pressure ridge north of the islands will build into the Hawaii Region,producing more stable conditions with less clouds, lower shower trends, and increasing trade wind speeds into the moderate to breezy range through Friday. Expect limited showers for most windward areas with lower shower activity over the typically 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 rain showers will likely continue. && .AVIATION... Moderate to locally breezy trades will continue through tonight. Some brief MVFR cigs/vsbys will be possible in windward areas, particularly over the Big Island early this morning. Otherwise, VFR conditions are expected to prevail. No AIRMETs are currently in effect. && .MARINE... High pressure north of the state will bring fresh to strong trade winds today and persist through most of the week. A Small Craft Advisory has been issued for the waters and channels around the Maui and The Big Island. Trades may weaken slightly on Wednesday, before a slight uptick on Thursday and Friday. 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 late today through the middle of this week 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 by this weekend and 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. During our last full moon, we received 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... Small Craft Advisory until 6 AM HST Wednesday for windier waters around Maui and the Big Island. && $$ DISCUSSION...Bohlin AVIATION...Jelsema MARINE...JT