(BIVN) – A Flash Flood Warning was issued Friday morning for West Hawaiʻi, as the main rain shield of a front shifts over the Big Island after drenching the other Hawaiian islands yesterday.

“At 6:35 a.m. HST, radar and rain gages indicated heavy rainfall over the west side of the Big Island,” the National Weather Service wrote. “Peak rain rates of 1 to 3 inches continue to move onshore over the North Kona District from Keauhou to Kailua-Kona. Kawainui, Alakahi and Waiaha streams have risen rapidly in response to the rain. Additional rainfall is likely to continue to move over the Big Island from the southwest through mid-morning.”

According to the forecasters, some locations that will experience flash flooding include Kailua-Kona, Captain Cook, Waikoloa Village, Kapaʻau, Honalō, Kainaliu, Kealakekua, Hōlualoa, Hōnaunau, Kahaluʻu-Keauhou, Pōhakuloa Training Area, Puʻuanahulu, Kalaoa, Puakō, Kawaihae, Waimea, Kohala Ranch, Hawaiian Ocean View, Waipiʻo Valley and Waimanu Valley.

Also, doppler radar at 6:17 a.m. HST was tracking a strong thunderstorm 15 miles northwest of Hawaiian Ocean View, or 30 miles south of Kailua-Kona, moving northeast at 10 mph. The storm was producing wind gusts up to 50 mph. 

The National Weather Service this morning wrote that front “is expected to fall apart over the eastern third of the state (or around Big Island) in response to weakened forcing and the influx of a drier, post frontal air mass.” From this morning’s NWS discussion:

Due to the progressive nature of the rain, the main near term thunderstorm threat will be from localized wind gusts up to and in excess of 60 mph across Big Island this morning. Recent rain episodes of rain rates of 1 to 4″ per hour rates over Oahu induced the flooding of many roads and low-lying areas while producing some minor flooding along various streams yesterday. The latest deterministic, global scale guidance indicates that the greatest mid-level instability will continue shifting east Big Island during the day. Higher resolution modeling propagates the highest QPF quickly eastward onto Big Island by sunrise, holding it up there through the day. Thus, convection is still expected to migrate eastward and will refocus heavy rain over more leeward areas of eastern Maui and Big Island for the remainder of the morning.

High resolution model guidance is depicting that the heaviest rain activity will shift east of Maui and onto Big Island this morning, but the larger scale models paint the picture of the greatest mid layer moisture/tightest instability gradient not moving, or remaining anchored over east Maui and vicinity the next few hours. These inconsistencies hold onto higher chances of a slowing line near or over Big Island that could create a prolonged flooding threat into the early afternoon. This outcome would delay the onset of heavy rain over Big Island and the snow over the summits until later this morning and afternoon. The instability gradient shifts over the Big Island late today as low pressure pulls away and overall forcing diminishes their flash flood threat.