textproduct: Honolulu

SYNOPSIS

Showers will continue to decrease in coverage and intensity today. South-southeast winds continue today and then easterly trades build back in this weekend and into next week. This will be a drier trade wind pattern but windward and mauka showers should return in the overnight to early morning hours.

DISCUSSION

Currently (3 AM HST), radar imagery showed showers, some heavy at times continuing over the eastern end of the state. The upper level low to our northwest that has been helping to bring rain to the state the past 24 hours, is expected to remain nearly stationary through Sunday before weakening moving off to the northeast early next week. With the low still nearby and not sufficiently weakened, showers remain in the forecast but decrease in coverage and intensity through Saturday.

A surface high will build to our northeast this weekend into early next week, bringing trades back to the region. A drier trade wind pattern sets up through at least midweek. Windward and mauka locations will see occasional showers as areas with slightly more moisture move through periodically. Models are hinting at one of these areas moving through Tuesday and Wednesday however at this point confidence remains low on exact timing and or any impacts.

AVIATION

We briefly transition back into easterly trade winds today in a drier weather pattern lasting through the weekend. Mostly VFR conditions are forecast through Sunday.

AIRMET Sierra remains in effect for mountain obscuration for all islands in Maui and Hawaii Counties. This AIRMET will likely be cancelled later this morning.

AIRMET Tango remains in effect for low level turbulence downwind of terrain. In southerly winds, the favored areas are over and immediately northwest through northeast of island mountains. This AIRMET will also likely be cancelled later this morning.

MARINE

A low pressure system to the northwest of the Hawaiian Islands will result in moderate to fresh south to southeast winds and enhanced showers across the state that will begin to wane today. Trade winds nose in from the east this weekend and early next week for the eastern portions of Hawaiian waters, but a trough will remain west of the area keeping winds fairly light across the western half of the state. The initial return of easterly winds may be in the fresh range tonight and Saturday but they become moderate or weaker Sunday into the rest of the week.

Moderate, long period south swell will produce surf along south-facing shores close to, but below, advisory level today. This swell will fade gradually through the weekend, but another long-period reinforcement is set to arrive on Saturday and peak Sunday into Monday. Surf will remain just below advisory levels along south-facing shores during this time before declining by the middle of next week.

Moderate surf is also expected along north and west facing shores as a medium-period swell produced by low pressure to the northwest of the islands peaks this afternoon into tonight, before declining through the weekend. A smaller long period northwest swell is also forecast to move through the islands this weekend and fade by the beginning of next week. A swell slightly larger than the present one will arrive on Monday and peak Tuesday, boosting north shore surf again but staying below advisory levels. Surf along east facing shores will remain small as local winds remain fairly weak.

HFO WATCHES/WARNINGS/ADVISORIES

None.