textproduct: Honolulu

SYNOPSIS

Strong high pressure well north of the state (40N to 45N) will produce breezy trade winds into the first half of next week. A slight weakening and veering of the trade winds is possible during the second half of next week as the high pressure moves northeast and low pressure potentially develops in the tropics to the SSW. An increase in moisture will bring enhanced showers to windward and mauka locations Saturday night into Sunday, and again Tuesday into Wednesday.

DISCUSSION

Radar shows isolated showers windward and mauka this afternoon as we await an increase in moisture coming in late tonight through Sunday. Skies were sunny to mostly sunny over most areas. Trade winds were still breezy, averaging 10 to 20 mph with gusts above 30 mph in favored locations.

Models continue to show an area of increased moisture moving in late tonight and lasting through Sunday. We have slightly increased the chance of showers, especially windward and mauka, through this time period. A second similar area is coming into focus in the guidance, due to arrive Tuesday afternoon through Wednesday afternoon. Otherwise, expect a continuation of trade winds with only a slight drop off in speed as we move into the new workweek.

To our south, we are seeing continuing signs of potential tropical storm formation, but at this time there is nothing that would directly impact the state. Farther out in time (July 20 to the end of the month), chances increase but still remain small.

AVIATION

Breezy trades deliver periodic showers to windward locales through the forecast period. Persistent MVFR will be possible where showers are most persistent, such as Windward Kauai this afternoon and potentially Windward Big Island and Maui tonight.

AIRMET Sierra for mtn obsc in effect for Windward Kauai.

AIRMET Tango in effect for lee turb.

MARINE

Strong high pressure will remain anchored far north of the state, driving fresh to strong trade winds across the region. A Small Craft Advisory (SCA) remains in effect across all Hawaiian coastal waters through Sunday afternoon, though marine zones outside of the typical windier waters look borderline. The trades will weaken slightly heading into early next week, which will likely lead to the SCA being scaled back to those windier waters and channels around Maui County and the Big Island.

The current small medium-period south-southwest (190-200 degrees) swell will hold surf just below the summer average through the evening. A small to moderate, long-period southwest swell (220 degrees) will fill in tonight through Monday, which will boost surf through early next week. Forerunners from this swell have started to fill in along south-facing shores, as evidenced by a slight boost in the 18 to 22 second band energy observed at the Barber's Point and Lanai buoys this afternoon.

Surf along east-facing shores will remain rough and choppy through the forecast period as fresh to strong trades hold. A series of small, moderate period west (270 to 280 degrees) swells will hold into early next week, followed by a small, long-period west-northwest (280 to 290 degrees) swell heading into midweek, sourced from Typhoon Bavi in the far western Pacific. No significant north or northwest swells are expected, so surf along north-facing shores is expected to remain flat to tiny.

Higher than normal high tides are expected due to upcoming King Tides, and with water levels running slightly higher than predicted, minor coastal flooding will be possible each afternoon starting tomorrow through Wednesday. However, minor coastal flooding is most likely to occur on Monday and Tuesday afternoons. Interests immediately along the coasts in low-lying or vulnerable areas should continue to monitor forecasts.

HFO WATCHES/WARNINGS/ADVISORIES

Small Craft Advisory until 6 PM HST Sunday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Big Island Windward Waters-Kaiwi Channel-Kauai Channel-Kauai Leeward Waters-Kauai Northwest Waters-Kauai Windward Waters- Maalaea Bay-Maui County Leeward Waters-Maui County Windward Waters-Oahu Leeward Waters-Oahu Windward Waters-Pailolo Channel.