Hurricane Hilda Weakening in the Central Pacific; Impacts Possible in Hawaii This Week

August 9,2015

Highlights:

• Hurricane Hilda is now weakening and has maximum sustained winds of 100 mph as of late Sunday, Hawaii time. This makes Hilda a Category 2 hurricane on the Saffir-Simpson Hurricane Wind Scale.
• The center of Hilda was more than 500 miles east-southeast of Hilo, Hawaii, as of late Sunday and is moving to the northwest.
• Hilda will continue to weaken due to increasing wind shear as it moves over open water the next few days.
• It remains too soon to tell what, if any, impacts Hilda will bring to Hawaii sometime late this week. The latest thinking suggests a weakened Hilda may move near or either side of the Big Island late this week. See below for more information on what impacts are likely or possible in Hawaii.
• Hilda reached its maximum intensity as a Category 4 hurricane with top sustained winds of 140 mph late Saturday.

(MORE: Typhoon Impacts Taiwan | Hurricane Central)

Hawaiian Concern?

Latest Information and Infrared Satellite

By late this week, Hilda will approach the vicinity of Hawaii's Big Island in a much weaker state. It's likely that Hilda will be either a tropical depression or a weak tropical storm by that point.
As we saw with Guillermo last week, the eventual path of Hilda will dictate exactly what impacts Hawaii may see. If you recall, Guillermo passed well enough to the north of Hawaii to only bring high surf to our nation's fiftieth state.
For now, here are what impacts are likely or possible depending on Hilda's future path and strength:
LIKELY: High surf is expected on the east facing shores of the Big Island and Maui starting late Sunday. The National Weather Service has posted a high surf advisory for this area through Wednesday morning. Waves of 6-10 feet and dangerous rip currents are expected.
POSSIBLE: Depending on the exact path and strength of Hilda, the Big Island could see enhanced rainfall chances possibly starting as early as Wednesday. Gusty winds are possible too. Again, all of this is dependent on Hilda's future path.

Projected Path

Virtually every system approaching Hawaii from the east since 1950 tracking at least as far north as the latitude of the Big Island of Hawaii eventually weakened to a tropical storm or depression by the time it reached the islands.
(FORECASTS: Honolulu | Hilo | Kona Coast | Maui)
We discussed the reasoning behind this in a piece written in August 2014.
Last August, Iselle became only the second tropical storm to landfall on the Big Island dating to 1950, after strengthening to a Category 4 hurricane.
Incidentally, hurricanes Julio and Ana also passed near the Hawaiian Islands in 2014. Ana was one of only four hurricanes since 1950 to pass within 150 nautical miles of Honolulu, dumping locally heavy rain and generating high surf.
Hurricane specialist Michael Lowry says 17 tropical cyclones of at least tropical storm intensity have tracked within 100 nautical miles of Hawaii dating to 1950. Three of those -- Tropical Storm Flossie (2013), Tropical Storm Iselle (2014) and Hurricane Ana (2014) -- have done so since 2013.
This may not be the season's last named storm to gain Hawaii's attention.
NOAA's 2015 central Pacific hurricane season outlook cited El Nino's tendency for reduced wind shear and more storm tracks coming from the eastern Pacific as reasons to expect an active season in the central Pacific Basin.
MORE: Hurricanes By the Numbers (PHOTOS)