textproduct: Honolulu

SYNOPSIS

Moisture will decrease through the weekend with light to moderate trades returning. Showers will impact windward and mauka locations. A brief increase in showers expected Monday night on the Big Island before a return to relatively dry trades through the end of next week.

DISCUSSION

Currently at 3 AM HST, satellite and radar imagery showed scattered clouds and showers moving along mostly windward and mauka locations across the state.

The upper level low that brought rain to the area this week will weaken and move away to the northeast over the next few days. A surface high pressure system to our northeast will strengthen and bring easterly trades back to the region. Apart from a brief increase in moisture mainly for the Big Island Monday, the next several days will be dominated by relatively dry trades. Isolated to scattered showers windward and mauka will be most frequent at night. Otherwise, expect light to moderate winds and rather typical October conditions.

AVIATION

Moderate trade winds build back into the islands through the weekend. VFR conditions will prevail at all airfields.

No AIRMETS are currently in effect or expected.

MARINE

Moderate to fresh trade winds will build back over the majority of the coastal waters this weekend, though weaker winds will remain in place over the western waters as a trough continues to linger west of the area. Although there will be slight day to day fluctuations, gentle to fresh trades will prevail throughout much of next week.

The current moderate, long period south swell will fade gradually through the weekend, but a long-period reinforcement is set to arrive on Saturday, then peak Sunday into Monday. This will maintain elevated surf along south and west- facing shores, but it will remain below advisory levels. South shore surf will decline slightly by the middle of next week, but will be followed by a new long period swell Wednesday night or Thursday.

A medium-period northwest swell declines through the weekend as the source low pressure northwest of the Hawaiian Islands continues to weaken through Monday. This will cause small surf along north-facing shores to begin to fade today. A smaller long- period northwest swell is also forecast to move through the islands this weekend, which could prolong small surf through Sunday, but will fade by the beginning of next week. A small, long-period northwest swell is forecast to arrive on Monday and peak Tuesday, boosting north shore surf back to moderate levels.

Surf along east-facing shores will remain small as local winds remain fairly weak with only slight variations each day. Small, moderate-period west and east swells generated by multiple Pacific tropical cyclones are also moving through the islands this weekend.

FIRE WEATHER

Light to moderate trades expected. Moisture will decrease Saturday night into Sunday, bringing RH values down to near dangerous fire conditions Monday on part of the Big Island, including near Kona. Inversion heights are around 5500-6500 feet.

HFO WATCHES/WARNINGS/ADVISORIES

None.