West Maui : Lahaina, 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.

wave run-up forecast graphic for Lahaina

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 Lahaina 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. One or more of the following threshold levels is/are shown in the red shaded area in the plot above: (a) Light Impacts, (b) Hazardous Impacts, (c) Critical Impacts. Click on the Run-up Examples tab for descriptions of the possible hazards.

Notifications

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

The Lahaina region includes most of Lahaina town and reaches from Mala Wharf at the north end to Pualoke Place (within the Puamana development) at the south end. The region is densely developed with commercial and residential development along the shoreline. Most of the Lahaina town shoreline has been hardened by seawalls and revetments. Some buildings are built on pilings out over the water. There are a few narrow sandy or cobble beaches, being widest at the northernmost end. The region is protected from waves by a shallow and wide fringing reef. Front St. and other infrastructure are often very close to the shoreline, and may be subject to impacts from high waves.

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 shoreline hardening; and/or erosion in vulnerable locations.

(c) Critical Impact – strong battering of shoreline hardening structures; waves regularly overtopping artificial shoreline hardening; flooding of adjacent roads, land and buildings; and/or significant erosion of vulnerable locations.

Run-up Examples

(a) Light Impact Event — July 13, 2019 | Shark Pit

Light Impact Lahaina

Photo Credit: Lisa Agdeppa.

Light Impact Map Lahaina

(a) Light Impact Event — July 4, 2020 | Lahaina

Light Impact Lahaina

Photo Credit: Penny Wakida (Hawaiʻi and Pacific Islands King Tides Project). (orange star on map)

Light Impact Lahaina

Photo Credit: Penny Wakida (Hawaiʻi and Pacific Islands King Tides Project). (orange star on map)

Light Impact Lahaina

Photo Credit: Penny Wakida (Hawaiʻi and Pacific Islands King Tides Project). (blue star on map)

Light Impact Map Lahaina

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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