Call her Guillermo’s feisty sister.
Call her Guillermo’s feisty sister.
Hilda blew up into a major Category 4 hurricane Saturday as it moved into the Central North Pacific basin. The latest forecast track has the cyclone’s center passing 150 to 200 miles northeast of the Big Island as a tropical storm with winds of at least 50 mph on Wednesday. However, the Big Island is within the forecast “cone of uncertainty,” and could be directly impacted if the storm shifts south.
Hilda is a compact system which whipped up 140 mph winds before weakening slightly to 135 mph Saturday afternoon. The cyclone is following a track similar to Hurricane Guillermo one week ago. Located 800 miles east-southeast of the Big Island, the cyclone was traveling west at 15 mph through an area of low wind shear and warm sea surface temperatures on Saturday evening. Hurricane force winds extended out 25 miles and tropical storm force winds reach out 125 miles.
A developing weakness in a midlevel ridge about 300 miles east of the Big Island is expected to slow the cyclone’s forward speed and turn it on a more northwesterly track as it approaches.
At the same time, increasingly intense wind shear from a subtropical jet stream is slated to begin rapidly weakening the system by Monday, according to forecasts by the Central Pacific Hurricane Center.
Hawaii County Civil Defense was monitoring the storm over the weekend and issuing advisories on the cyclone, emphasizing the uncertainty of the storm’s track and urging residents to plan and prepare early for possible impacts.
“It’s hard to forecast with 100 percent accuracy and the National Weather Service does a great job forecasting possible outcomes,” Civil Defense Chief Darryl Oliveira said. “We would like people to listen to the advisory messages and do what they can early.”
Oliveira said the normal last-minute rush at stores seemed to be absent as Tropical Storm Guillermo approached, and he credited the community with preparing early.
The Central Pacific is approaching the peak of hurricane season, which runs through Nov. 30.
The region has already seen a very busy season even as forecasters issued one of the quietest outlooks in history for the Atlantic hurricane season in an update Thursday.
El Niño conditions in the Pacific have increased ocean temperatures and reduced wind shear — the often wide variation in wind speed and direction at different levels in the atmosphere that help to tear cyclones apart — in the waters where storms are generated east of here.
Additionally, El Niño has helped spawn cyclones by creating higher moisture at midlevels in the Eastern Pacific, said Phil Klotzbach, a hurricane expert with the Department of Atmospheric Science at Colorado State University, in an email.
Email Bret Yager at byager@westhawaii today.com.