Hawaii Island Weather Update for August 2nd, 2019
Flash Flood Watch and High Surf Warning for Hawaii Island has been canceled, however a Wind Advisory for Hawaii Island remains in effect through Friday evening.
The National Weather Service (NWS) reports the Flash Flood Watch and High Surf Warning originally in effect for Hawaii Island has since been canceled. However the following advisories remain in effect through this evening:
WIND ADVISORY REMAINS IN EFFECT UNTIL 6 PM HST THIS EVENING * WINDS...East 20 to 40 mph with localized gusts over 45 mph for portions of Maui County and the Big Island. * TIMING...through this afternoon as Tropical Storm Erick passes to the south. * IMPACTS...Winds this strong are capable of downing trees and causing power outages. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Wind Advisory means that sustained winds of at least 30 mph, or gusts of at least 50 mph, are expected. Use extra caution when driving and be prepared for longer commutes. Protect sensitive electronics that may become damaged by power fluctuations.
Hawai'i Weather Outlook (as of 4:17 pm Friday afternoon)
Synopsis
Tropical Storm Erick will weaken and slowly track south of the island chain. Rain will linger across the eastern half of the state tonight before trade wind weather returns through the weekend. Later this weekend through early next week, Tropical Storm Flossie will approach and could bring additional impacts to the islands.
Discussion
The center of Tropical Storm Erick was located about 17N159W, or about 320 miles south of Honolulu, moving to the west northwest. Water vapor imagery shows an upper low centered 27N163W, or about 500 miles northwest of Honolulu. The upper low is embedded in a broader trough with the subtropical jet running southwest to northeast over the islands along the base of the trough. The strong wind shear (around 40 to 45 mph) associated with the jet is weakening Erick evident by the exposed low level circulation on visible satellite. While the bulk of the rain remains south of the state, radar shows pockets of light stratiform rain along the northern periphery continue to track across Maui County and over the Big Island to a lesser extent. Thick, layered clouds persist across both counties this afternoon, with cirrus clouds along the northern edge of the band over Oahu.
A 1023 mb high 1500 miles to the northeast is driving fresh to locally strong trade winds across the state this afternoon. Low clouds and passing showers are favoring windward and mauka areas of Kauai and Oahu. The Wind Advisory that was in effect for Maui County and the Big Island has been cancelled, but anticipate a few breezy gusts in the Kohala area tonight. Winds should gradually trend down through the weekend as the pressure gradient between Erick and the high relaxes over the islands. Rain coverage tonight will also be on the decline tonight as Erick moves west northwest away from the islands.
For the weekend, expect a return to a trade wind weather pattern with windward and mauka showers, and some showers passing to leeward sides of the smaller islands. Moisture levels are still high with most surface observations showing dew points in the upper 60s to low 70s. 00Z soundings show stabilizing midlevels with precipitable water values 1.8 to 1.9 inches (though some of this is due to the high clouds).
As Erick departs, the focus will shift to Tropical Storm Flossie which is currently about 1150 miles east of Hilo moving towards the west northwest. The forecast track brings Flossie within 300 miles northeast of Hilo around Monday before shifting on a more northwesterly track away from the state. As there is still a good distance between the storm and the islands, it's hard to say how Flossie will impact the state Monday into Tuesday. As we are anticipating a more northerly turn during the first part of next week, Flossie will likely come between the subtropical high and Hawaii which will drastically weaken the winds over the islands next week. Expect several days of muggy weather and a convective land/sea breeze pattern as Flossie moves away.
Rainfall Totals as of 4:15 pm Friday afternoon
(Timeframe: 12am - 4:15pm on August 2nd)
(Courtesy of Wunderground)
Highest Rainfall accumulations on Hawaii Island Rainfall Data from Wunderground Network - Personal Weather Stations (PWS): (Sorted by District)
Puna
- Royal Hawaiian Estates (Ola'a): 4.95"
- Volcano Village: 4.05"
- Kea'au (Pala'ai Street): 3.88"
- Kea'au High School: 3.63"
- Eden Roc: 3.72"
- Ainaloa Subdivision: 3.46"
- Hawaiian Paradise Park: 3.36"
- Mauna Loa Estates: 3.35"
- Fern Acres: 3.32"
- Leilani Estates: 3.16"
- Kalapana: 2.99"
- Kalapana Seaview Estates: 2.94"
- Hawaiian Beaches: 2.49"
South Hilo
- Waiakea Uka (near Ahualani Park): 3.70"
- Waiakea Uka (West Kawailani Street): 3.34"
- Haihai (near Hilo Municipal Golf Course): 3.32"
- Waiakea Uka (Ho'ohoaloha Street): 3.22"
- Hilo High School: 3.27"
- Upper Pauka'a: 3.24"
- Upper Kaiwiki: 2.43"
- Papaikou: 2.42"
- Hakalau: 2.30"
North Hilo
- Ninole: 1.26"
- Laupāhoehoe: 0.99"
Hamakua
- Pa'auilo: 0.97"
- Honoka'a: 0.91"
- Upper Pa'auilo (Homesteads): 0.67"
- Ahualoa: 0.63"
- Kapulena: 0.41"
South Kohala
- Mokuloa: 0.21"
- Kamuela: 0.20"
- Hawaii Preparatory Academy: 0.16"
North Kohala
- Honomakau: 1.25"
- Hawi: 0.56"
- Ainakea (Kapa'au): 0.47"
North Kona
- Hualalai Ranch: 0.04"
- Upper Kaloko Drive: 0.03"
- Pu'u Lani Estates (Pu'uanahulu): 0.02"
South Kona
- Honomalino: 0.43"
- Miloli'i: 0.28"
- Kona Paradise: 0.22"
- Ke'ei: 0.05"
Ka'u
- Na'alehu (Lorenzo Road): 1.87"
- Mark Twain Estates: 1.75"
- Discovery Harbour: 0.69"
- Waiohinu: 0.21"
- Volcano: 1.84"
Water Quality Advisories
No Additional Brown Water Advisory Alerts have been added as of 4:00 pm Friday afternoon for Hawaii Island.
However, the Brown Water Advisory for Hilo Bay remains in effect from rainfall on July 29th, 2019.