Niala Prompts High Surf Advisory for Weekend
A Tropical Storm Watch is posted for Big Island waters through 6:00 a.m. Monday for the possibility of tropical storm conditions on the Big Island and coastal waters.
A Flood Watch is posted for the possibility of very heavy rain and flash flooding through Monday afternoon. Rain is expected to be the greatest hazard with respect to Niala. Rain amounts of 6 to 12 inches and possibly up to 16 inches are possible.
The ground is saturated so flooding may occur quicker than usual. Also, heavy rain events of this size may cause flooding in areas outside the designated flood zones. Low spots in the road will become dangerous and impassable due to severe runoff. High amounts of debris in streams and gulches may clog bridges and culverts resulting in dangerous flooding outside the normal channel and significant property damage.
A High Surf Advisory is posted for easterly exposures with wave heights of 5 to 8 feet or more expected through 6 a.m. Monday. The surf is forecast to build Saturday, peak Saturday night and Sunday and fade Sunday night into Monday.
**Click directly on the images below to make them larger. Charts include: Big Island projected winds, tides, swell direction & period and expected wave heights.**
Hilo side: Wave heights are expected shoulder/head high today. Storm surge and wave heights are expected to build through the day and peak Saturday night for easterly exposures open to the Niala swell.
Kona side: Wave heights knee/thigh high are expected today. Swell is fading through the day. Breaks open to the southeast could see wave heights building due to Niala swell.
South: Wave heights chest/head high are expected for the breaks open to the swell generated by Niala. By sunset wave could be several feet overhead.
Trade winds will continue to generate short-period choppy surf at moderate levels along east facing shores through the weekend. Niala will direct short-period swell primarily toward east-facing shores of the Big Island. Surf and storm surge are expected to build up to 8 to 12 feet along southeast facing shores. Overnight and afternoon high tides of about 2 feet will bring wave run up slightly higher during those times. Wind, surf, and seas are expected to decline gradually early next week as Niala weakens and moves away from the state.
Keep in mind, surf heights are measured on the face of the wave from trough to crest. Heights vary from beach to beach, and at the same beach, from break to break.