Residents of the Considerable Island can breathe a temporary sigh of relief as the immediate threat of flash flooding subsided early Saturday morning. The National Weather Service (NWS) in Honolulu canceled a critical flood advisory at 4:43 a.m. On April 11, 2026, just 17 minutes before the alert was scheduled to expire at 5 a.m.
The decision to lift the advisory came after radar data indicated that the heavy rainfall which had plagued the region overnight had diminished. While the immediate risk of flash flooding has passed, meteorologists warn that the danger is not entirely gone. A broader flood watch remains in effect for the entire state, including the Big Island, through 6 p.m. Monday, April 13.
The overnight weather event saw a rapid escalation in intensity, with automated rain gauges recording moderate to heavy precipitation between 0.5 and 1.5 inches per hour starting around 1:47 a.m. Saturday. This volume of water created hazardous conditions for drivers and residents, particularly in areas with poor drainage and near streams that were already running high from previous weather systems.
Timeline of Saturday’s Weather Escalation
The shift in weather patterns occurred rapidly during the early hours of Saturday, moving from general instability to an active flood threat. The following sequence outlines the progression of the alerts issued by the National Weather Service.
| Time | Event/Action | Status |
|---|---|---|
| 1:47 a.m. | Heavy rain (0.5–1.5″/hr) detected via radar | Active |
| 3:40 a.m. | New Flood Advisory issued for Big Island | Active |
| 4:43 a.m. | Flood Advisory canceled by NWS Honolulu | Resolved |
| Ongoing | Statewide Flood Watch in effect | Active until Monday |
The early morning volatility was compounded by the simultaneous cancellation of previous winter weather and wind advisories, signaling a shift toward a moisture-heavy tropical pattern rather than a wind-driven or cold-weather event.
Areas Most Impacted by Rainfall
The NWS identified a wide array of locations across the Big Island that were particularly susceptible to flooding during the peak of the storm. The moisture was not concentrated in a single valley but spanned multiple districts, affecting both coastal communities and inland highlands.
Key locations identified as high-risk areas included:
- West and South coasts: Kailua-Kona, Captain Cook, Kealakekua, Hōnaunau and Kahaluʻu-Keauhou.
- Central and North regions: Waimea, Waikoloa Village, Kohala Ranch, and Kapaau.
- Rural and Highland areas: Pōhakuloa Training Area, Hōlualoa, Honalo, and Puʻu Anahulu.
- North Shore and Valleys: Hāwī, Hala‘ula, Pololū Valley, and Puakō.
In these regions, the primary concern was the intersection of saturated soils and elevated stream levels. When ground is already saturated, additional rainfall cannot be absorbed, leading to immediate runoff that floods roadways and low-lying drainage areas.
Understanding the Alerts: Advisory vs. Watch
For those tracking the Big Island Saturday severe weather updates, it is important to distinguish between the different levels of alerts used by the National Weather Service to communicate risk.
A flood advisory is a higher-tier alert indicating that conditions for minor flooding are imminent or currently occurring. It serves as a call to immediate caution. In contrast, a flood watch is a broader notification that conditions are favorable for flooding to occur. It does not mean flooding is guaranteed, but it means residents should be prepared to take action if a watch is upgraded to an advisory or warning.
The Long-Term Outlook and Tropical Moisture
While the early Saturday morning flood advisory was canceled, the overarching weather pattern remains unstable. Forecasters in Honolulu extended the statewide flood watch through Monday evening due to a disturbance approaching from the northwest.
This atmospheric disturbance is expected to renew deep tropical moisture across all the Hawaiian Islands beginning late Saturday night. The timing is particularly concerning for emergency managers because the soils are already saturated from the Saturday morning rain. When the ground reaches a saturation point, even moderate rainfall can trigger rapid flooding because the water has nowhere to travel but over the surface.
The combination of elevated stream levels and incoming tropical moisture means that flooding could redevelop quickly over the next 48 to 72 hours. Residents are encouraged to monitor local weather updates and maintain a level of readiness, especially those living near stream banks or in areas prone to runoff.
For the most current and official updates, residents should refer to the National Weather Service or their local county emergency management agency.
The next critical window for weather monitoring begins late Saturday night as the northwest disturbance enters the islands’ vicinity. Forecasters will continue to track moisture levels and stream gauges to determine if further advisories are necessary before the watch expires on Monday.
Do you have photos or reports of flooding in your area? Share your updates in the comments below or send them to our newsroom.
