West Maui : Olowalu, Maui

ForecastMapRun-up ExamplesArchive

Attention: The forecast is not accurate when a tsunami, tropical storm or cyclone watch/warning is in effect. For these events, please seek information for either tsunamis or tropical storms/hurricanes. In case of a possible inundation event, please consult with local authorities and emergency responders to seek further information and direction.

One or more of the following threshold levels is/are shown in the red shaded area in the plot below:
(a) Light Impacts, (b) Hazardous Impacts, (c) Critical Impacts. To better understand their definitions, please check out the Run-up Examples.

wave run-up forecast graphic for Olowalu

The Solid Dark Blue Curve and Solid Cyan Curve display the Past and Forecast Sea Level for the previous 3 days and the next 6 days, respectively, relative to Mean Lower Low Water (MLLW, a typical NOAA datum). Past Sea Level is obtained from a combination of a local tide model with the long-period, non-tidal sea level variability being observed in real-time at Kahului Harbor. Grey vertical lines provide the associated times of high tides.

The Hatched Cyan Curve shows the forecast maximum height (or, run-up height) reached by waves along the shoreline in the Olowalu region for the next 6 days, relative to MLLW. The run-up height will always exceed or equal the tide plus background sea level described above, because the waves are riding on top of that sea level. The Hatched Dark Blue Curve shows a history of the last forecast run-up height determined for each particular time of the past 3 days; this curve provides context to show how the forecast run-up for the next 6 days differs. For more information on how the forecasts are produced, see the Details tab on the Overview Page.

If the forecast run-up extends into the red shaded region on the plot, the waves are expected to at least become a disruption for beach activities. The higher the forecast the more severe the expected effects. Click on the Run-up Examples tab for descriptions of the possible hazards.


If you would like to receive notifications when the forecast for Olowalu (or any other West Maui region) reaches the impact stage, please register here:

The Olowalu region reaches from the Launiupoko Stream at the north end, about 1 km (0.6 mi) south of the Launiupoko Beach Park, to the Olowalu Wharf in the south. There is no development along the shoreline until Olowalu town. The shoreline is composed mostly of a veneer of sand or cobble underlain by volcanic sediment and rock. Width and depth of the fringing reef varies through this region providing moderate to little protection from wave energy at the shoreline. Honoapiʻilani Highway is often very close to the shoreline, so the road is subject to impacts from high waves and the shoreline has been artificially hardened to protect the road in some areas.

Run-up Thresholds

(a) Light Impact – beach and nearshore activities disrupted as occasional waves may sweep the entire beach width.

(b) Hazardous Impact – heavy wave action on beaches; likely run-up onto the parts of the coast that are not artificially hardened; battering of artificial shoreline hardening structures; occasional wave overtopping of artificial shoreline hardening structures; and/or erosion of exposed volcanic sediment.

(c) Critical Impact – strong battering of artificial shoreline hardening structures; waves regularly overtopping artificial armor; flooding of adjacent low-lying roads and land; and/or significant erosion of exposed volcanic sediment.

Run-up Examples

Photo documentation of run-up examples and associated impacts will be added to this region once they become available.

Get Involved!

We continue to collect photo documentation to fine-tune the model (if necessary) and to identify the impacts of these run-up events along the West Maui shoreline. We are specifically interested in photos around peak tides or swells, or anytime waves overtop beach features. If possible, capture the maximum extent of water running up the shoreline. The contributions from you, our citizen scientists, greatly contribute to establishing accurate thresholds for the model. Mahalo for your support!

Please submit your photos at:

To view photo submissions, please check out:

An archive of previous forecast plots can be accessed below. Select a day of interest from the calendar, or use the slider tool to quickly navigate through all available images. Two historical forecast plots are provided for each day, generated at 6:00 AM and 6:00 PM of the local time zone. To view the most recent forecast and to learn more about the different components of the graph, please go to the Forecast tab.

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