Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
546 FXHW60 PHFO 011317 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 317 AM HST Tue Jul 1 2025 .SYNOPSIS... Light trades prevail across the Hawaiian islands as a surface trough persists just to the north. As this trough exits the vicinity of the islands by mid-week, high pressure will build to the north in its wake, backing trades to a more easterly component and increasing to a more moderate to breezy range through the remainder of the week. Expect drier conditions during this time as well. By the weekend and into next week, trades could become moderate to strong as high pressure is forecast to build further. && .DISCUSSION... Light trades prevail across the state in response to a surface trough that has persisted north of the islands that has deteriorated the pressure gradient. Some localized sea breezes may occur throughout the day again today, triggering possible leeward and interior area showers, but will be far less energized in comparison to earlier this week as the surface trough weakens and exits the vicinity to the west. Thereafter, the surface high well north of the island chain will rebuild, allowing trades to gradually back out of the east and strengthen slightly to moderate to localized breezy conditions. As the week progresses, expect drier conditions to ensue as drier air is progged to move into the vicinity of the islands. Despite this, typical trade showers can be expected across windward and mauka areas, but at modest levels given the lack of available moisture. This trend will continue through the weekend and into next week. Meanwhile, latest model guidance of the GFS and Euro remains in pretty good agreement that trades will strengthen further, becoming breezy to localized strong at times into early next week. The conjunction of drier conditions with these stronger trades could elevate fire weather concerns. While this is still several days out, and confidence remains low at the moment, conditions will be monitored by future shifts leading up to the weekend and into next week. && .AVIATION... Light trades will prevail, however, as a diffused surface trough exits the region to the west, the trades will strengthen slightly and gradually back out of the east. Some leeward and interior sea breeze clouds and showers will be possible again, but will likely be less active than yesterday. Brief periods of MVFR conditions will be possible in any showers, but overall VFR conditions should prevail. No AIRmets are in effect at this time. && .MARINE... A weak high pressure ridge anchored north of the Hawaiian Islands will keep gentle to fresh easterly trade winds in the forecast through Friday. The ridge will build in north of the island chain by Saturday, increasing trade winds into the fresh to locally strong range into early next week. There are no Small Craft Advisories (SCA) currently in effect, however stronger winds forecast to arrive this weekend will likely bring a return to SCA conditions for wind over the typically windier waters around Maui and the Big Island. A small long period south swell will hold around 2 feet through Wednesday. Another smaller longer period south swell then builds into the regional waters from Thursday onward, keeping surf heights along south facing shores fairly steady. Surf heights along E shores matches trade wind trends, subsiding and remaining small this week then increasing slightly this weekend. Surf heights along west facing shores will see some south swell wrap, with north facing shores remaining nearly flat. && .HFO WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Pierce AVIATION...Pierce MARINE...Bohlin