Tropical Storm Darby Crossing the Big Island South of Hilo; Dumping Rain on the Big Island

July 23,2016
Tropical Storm Darby is now crossing through the Hawaiian islands after making landfall near Pahala, Hawaii on the Big Island of Hawaii on Saturday afternoon.
Tropical Storm Darby will continue to produce heavy rain across the Big Island and Maui on Sunday.
The Governor of Hawaii declared the state of Hawaii a disaster area on July 22 ahead of Darby. This emergency proclamation frees up the use of emergency money for use in the state.
Tropical-storm-force wind damage is likely, especially on the Big Island.
A tropical storm warning has been issued for Hawaii and Maui Counties, and for Oahu. Winds of at least 40 mph are expected in those counties, and could be substantially higher in higher terrain.
A tropical storm watch has been issued for Kauai.

Darby Alerts

High surf from Darby will increase in Hawaii through Sunday. The Maui, Lanai, Molokai, and Oahu are forecast to see increased rainfall and breezy conditions from Darby on Sunday. The worst conditions will spread west throughout the day.
Impacts from tropical storm Darby can be found here.
Details on this forecast can be found below.

Darby Status and Forecast Timing

Darby was located a bit less than 25 miles south-southeast of Kailua-Kona, Hawaii, as of Saturday evening Hawaii time.

Sustained winds of 43 mph and a gust to 61 mph were reported at Kohala Ranch on the Big Island. Heavy rain and a wind gust to 45 mph has been recorded at Lanai City, Hawaii.

Storm Status

Darby is forecast to move south of Maui, Kahoolawe, and Lanai on Saturday evening (local time), and be near Oahu and Kauai on Sunday.

Darby is expected to slightly weaken while passing through the islands from southeast to northwest, and is expected to weaken to a tropical depression before reaching Kauai. 

Impacts could include tree and power line damage and inland flooding.

Projected Path

(MORE: Hurricane Season Outlook | Hurricane Central)

Current radar and winds

Full details are below. 

Darby Forecast Impacts

Rainfall:
Flash flood watches have been issued for the Big Island, Maui, Molokai, Lanai, Kahoolawe, and Oahu. Rainfall of 8-12 inches is possible especially on the higher terrain. The highest elevations and localized areas could see 15 inches. Lower elevations will see 3-6 inches, but runoff from higher terrain and localized high rainfall rates may still create flooding.
The greatest risk of flooding and mudslides will be on east and northeast facing slopes.

Rainfall Forecast

Some of this rainfall is not a bad thing. Most of the islands are reporting moderate to severe drought on their southward facing shores. 

Surf:

High surf will really begin to pick up Sunday morning (local time) on the eastward-facing shores of central Hawaii. Waves may grow to near 20 feet near the center of Darby on Sunday while Darby is south of Hawaii. 

Surf will grow to 10-18 feet on the northward and eastward-facing shores of Molokai, Oahu, and Kauai by Sunday morning. Waves will decrease on Sunday afternoon from east to west. 

Beach erosion is likely through Sunday, especially on northward-facing beaches. 

Winds:

As mentioned before, tropical-storm-force gusts are likely on Sunday in the tropical storm warning area that includes the Big Island, Maui County and Oahu. This means winds of 39 mph or greater are likely. These winds will spread westward throughout the day into Maui County by Saturday evening.

Gusty winds are likely in Maui, Kahoolawe, Lanai, and Molokai on Sunday morning, and in Molokai, Oahu, and Kauai on Sunday afternoon into Monday morning.

Locations at higher elevations will receive higher winds, possibly gusting to 55 mph on the highest peaks. 

Winds will also be locally higher in channels between islands and in between mountain/volcanic peaks. 

Exact locations of the highest wind and waves will depend on the exact track of Darby and its interaction with the islands. 

Probability of Tropical Storm Force Winds

Check back for updates over the next few days on potential impacts from Darby.

Darby's History

Tropical storm Darby made landfall as a 40 mph tropical storm on the Big Island near Pahala on July 23 very close to where Iselle made landfall in 2014. 

Darby reached its peak intensity as a Category 3 last Saturday afternoon. According to Dr. Phil Klotzbach, Darby is the fifth consecutive east Pacific use of the name "Darby" that has reached major hurricane status. 

MORE: Images of Hurricane Eyes