Wali Weakens to a Tropical Depression

Wali, which reached tropical storm status late Thursday afternoon, today was downgraded back to a tropical depression.

A bulletin issued by the Central Pacific Hurricane Center at 11 a.m. said Wali had maximum sustained winds of 35 mph, below the 39 mph threshold for a tropical storm.

Meteorologist Matt Foster said the weakening was caused by wind shear, or changes in vertical wind directions inside the storm.

“The upper levels are being separated from the lower levels,” he said.

At 11 a.m., Wali was located about 775 miles east-southeast of Hilo and was moving to the northwest at close to 13 mph.

Wali was expected to weaken further and become a post-tropical remnant low pressure system within 12 hours, and to dissipate within the next 24 hours.

This predicted storm track issued at 11 a.m. shows that the weakening Wali is expected to be downgraded to a post-tropical remnant low within 12 hours. NOAA/NWS image.

The system’s deep moisture combined with the low-pressure trough in the upper atmosphere will continue toward the state where it is expected to bring enhanced showers and thunderstorms.

The stormy weather is expected to arrive on the Big Island Saturday night and move on to the rest of the state Sunday.

Forecasters said the localized heavy rainfall is likely to cause flooding, especially over windward slopes.

Rainfall amounts of 5 to 10 inches are expected to be widespread, with totals of up to a foot possible in some locations.

Because Wali will have dissipated by the time it arrives, only typical trade winds of 10-20 mph are expected to accompany the rainfall, Foster said.

He said the unstable atmosphere means that thunderstorms are also likely.

A flash-flood watch was in effect for the entire state from 6 p.m. Saturday to 6 p.m. Monday.