Updated forecasts Thursday morning showed that Tropical Storm Ana is expected to pass to the southwest of Hawaii Island on Friday night after reaching hurricane strength.
Updated forecasts Thursday morning showed that Tropical Storm Ana is expected to pass to the southwest of Hawaii Island on Friday night after reaching hurricane strength.
Despite the center being estimated to largely bypass the island, the hurricane could produce tropical storm conditions on the Big Island late Friday, with the possibility of heavy surf hitting the windward side late Thursday and Friday morning and heavy rainfall beginning Friday afternoon.
A hurricane warning was in effect for waters throughout the state, while a tropical storm watch was in effect for waters surrounding the Big Island. Meanwhile, an islandwide flash flood watch will be in effect on the Big Isle from noon Friday through 6 p.m. Sunday.
“Large swells produced by Ana are possible over the eastern end of the main Hawaiian island chain starting late tonight and Friday morning,” reads the tropical storm advisory posted Thursday at 8 a.m. on the National Weather Service website. “These large swells will continue to spread up the island chain through the weekend. Surf produced by these swells could potentially be damaging along exposed shorelines beginning late Friday and Saturday, and persisting through the weekend in some areas.”
Additionally, the heavy rainfall could cause life-threatening flash floods and mud slides, according to the NWS.
As of 8 a.m., the storm was about 490 miles southeast of Hilo, displaying maximum sustained winds of 60 mph, moving toward Hawaii at 10 mph.
The storm was expected to begin to move along a west-northwest trajectory later Thursday into the evening and then move along an increasingly northwesterly track Friday and Saturday. After passing to the southwest of the Big Island Friday night, it is expected to approach close to Oahu, Kauai and Niihau over the weekend.
“On Sunday, a ridge building north of the cyclone will impart an increasingly westerly motion, with the timing of the turn having significant implications as to the potential impacts felt on those islands,” an NWS posting reads. “By Day 5, Ana is forecast to be entering the Papahanaumokuakea Marine National Monument, potentially affecting Nihoa.”
Despite the expectations for the center of the storm to bypass the Big Isle, the weater service warned that residents should prepare for the worst.
“It is important for people in the main Hawaiian islands not to focus too closely on the exact forecast track of Ana,” the posting reads. “With an average 48-hour track error of approximately 80 miles, it is still too soon to say with much certainty which islands will be most likely to experience the worst weather. Everyone should be prepared for the possibility of direct impacts from Ana.
“It is also important to keep in mind that significant impacts from tropical cyclones can extend well away from the center.”
Email Colin M. Stewart at cstewart@hawaiitribune-herald.com.