Tropical Storm Darby to impact Hawaii with high surf, beneficial rain this weekend

By Brett Rathbun, AccuWeather.com Meteorologist

July 22,2016; 11:25PM,EDT

 

 

Tropical Storm Darby, located less than 250 miles from the Big Island of Hawaii in the Central Pacific, is expected to bring locally heavy rain and high surf to parts of the islands late this week and into the weekend.
While the Atlantic Basin has hit a plateau in terms of tropical development this month, the Eastern Pacific is heating up.
Darby formed off the coast of Mexico on July 11 as a tropical depression then strengthened into a tropical storm on July 12. An environment conducive for development helped Darby become the third hurricane of the East Pacific season on July 13 and reach its peak intensity as a Category 3 hurricane on July 16.
Cooler ocean waters have since caused the storm to weaken.
"With Darby moving into a more moderate wind shear environment but increasingly warmer waters, it is expected to maintain tropical storm status over the next several days," AccuWeather Meteorologist Kevin Gilmore said.
Wind shear is the change in wind direction and wind speed with height. Tropical systems are typically stronger in a weaker wind shear environment.

"Darby is not expected to restrengthen back to a hurricane," Gilmore said.
At this time, Darby has taken a slight jog to the south, which may shift the area of heaviest rain into the Big Island.
"The Big Island will remain most at risk for impacts from heavy rain and locally damaging winds," according to AccuWeather Senior Meteorologist Andy Mussoline.
The exact track of the storm will determine whether or not heavy rainfall occurs on the Big Island and other islands.
"A track just south of the Big Island is most likely to produce significant rainfall in parts of the island chain," according to AccuWeather Hurricane Expert Dan Kottlowski.
The rain will be beneficial for the northern-facing shores, including Hilo, which has received below-normal precipitation so far this month. However, too much rain in a short amount of time could lead to localized flash flooding.
Any rain that falls on the southern-facing shores will also be beneficial in easing the ongoing drought.
"A system approaching from the east is not likely to bring heavy rainfall to the west-facing slopes," Kottlowski said.
Swimmers, surfers and operators of small craft should be aware of the threat for rip currents on the eastward-facing beaches as Darby approaches.
RELATED:
The latest on Darby
AccuWeather East Pacific hurricane center
2016 East Pacific hurricane forecast
The northern shores received high surf earlier this week from what was once Hurricane Celia. Celia was the first tropical system to make it into the Central Pacific basin, but lost tropical characteristics well away from Hawaii as it encountered cooler waters.
Tropical cyclones reach the Central Pacific basin when they cross 140 degrees west longitude.
Latest satellite loop of Tropical Storm Darby. (Image/NOAA)
With additional tropical systems expected to develop across the East Pacific through the end of July, there is the possibility that other storms may survive the trip into the Central Pacific and approach the Hawaiian Islands.
In 2015, a record 15 storms formed or entered the basin. Of these, eight storms brought either increased showers or higher surf to the islands.