Total Water Level and Coastal Change Forecast Viewer

This tool displays operational total water level forecasts and coastal change predictions for select regions of the U.S. coastline using local beach characteristics.

EXPERIMENTAL PRODUCT

The Total Water Level and Coastal Change Forecast Viewer should be not be solely relied upon to make important decisions about hazard response. The U.S. Geological Survey provides these forecasts “as is” but assumes no legal liability or responsibility resulting from the use of this information.

This model output is experimental. There may be times where the updates are not available.

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Total Water Level and Coastal Change Forecast Viewer: Information

What is total water level?

Total water level (TWL) at the shoreline is the combination of tides, surge, and wave runup . A forecast of TWL is an estimate of the elevation where the ocean will meet the coast and can provide guidance on potential coastal erosion and flooding hazards.

What is a coastal change forecast?

The TWL forecast is compared to the local dune features like the elevation of the base and/or crest of a sand dune to determine the probability of dune erosion, overwash, and inundation/flooding . In some locations, the elevation of coastal features may correspond to rocky cliffs, rip-rap, or infrastructure which do not erode or change like sandy beaches.

Who is making these forecasts?

The USGS National Assessment of Coastal Change Hazards project is working in collaboration with the National Oceanic and Atmospheric Administration (NOAA)/National Weather Service (NWS) and the National Centers for Environmental Prediction (NCEP) to make total water level and coastal change forecasts. This operational model combines NOAA wave and water level predictions and a USGS wave runup model with beach slope observations to provide regional weather offices with detailed forecasts of total water levels. The USGS compares these total water levels to the protective dunes along sandy coastlines to forecast the probability of coastal change.

Feeling nerdy?

More specifically, tides and subtidal water levels are provided by the Extratropical Surge and Tide Operations Forecast Systems (ESTOFS) and wave properties (wave height and peak period) are being provided along the 20-meter isobath by the Nearshore Wave Prediction System. These wave characteristics provide input for the empirical wave runup model developed by Stockdon and others, 2006. Beach slopes, also required by the wave runup model, are provided from multiple airborne lidar surveys in the same area. The method for determining average beach slope for U. S. sandy coastlines is available in Doran and others, 2015. The spatial and temporal uncertainty in total water level due to variability in beach slope is also predicted using the methodology described in Doran and others, 2015.

For more information on how beach and dune features are extracted from airborne lidar and the original framework of the coastal change forecasts, see Stockdon and others, 2015 .

Experimental Product

The Total Water Level and Coastal Change Forecast Viewer should be not be solely relied upon to make important decisions about hazard response. The U.S. Geological Survey provides these forecasts “as is” but assumes no legal liability or responsibility resulting from the use of this information.

This model output is experimental. There may be times where the updates are not available.

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Total Water Level and Coastal Change Forecast Viewer: How To and FAQs

FAQ's

Quick Start Guide

  1. If not already selected, click the Regions button at the top left (this is the default option).
  2. On the map, click the colored circle representing your region of interest. When the map zooms into the selected region, click any of the individual pins and the most recent total water level forecast for that site will appear on the right.
  3. To see historical forecasts, choose a forecast date from the calendar displayed by clicking the Select Forecast Date button.
  4. To view details for different site in the current region just click a different site pin on the map.
  5. To view a different region just click the Regions button above the map to reset the viewer and map.
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Terminology

Region:
A broad geographical area that includes many forecast sites.
Site:
A specific coastal location where a total water level and coastal change forecast has been generated.
Total Water Level (TWL):
This is the elevation where the ocean meets the coast and includes the combination of tides, surge, and wave runup.
Dune Erosion/Overwash/Inundation Coastal Change Forecasts:
Detailed information about these types of coastal change, which occur during storm events, is available at the linked web pages by clicking each term.
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Advanced Features and Tips

Favorites

The map can display sites within a region (region view) or all sites you have selected as favorites (favorites view). The Favorites map view button is disabled until you have added at least one site to your favorites. To add a site as a favorite simply click the Favorite button at the bottom of the site information balloon that appears in the map when you click on a site pin. Click the Favorite button again to remove it (button will turn white again).

To view all your favorites on the map, switch to favorite view by clicking the Favorites button at the top of the left pane.

Favorites are stored in a cookie on your computer’s hard drive and are browser dependent. If you switch to a different computer then you will find your favorites are missing. Likewise if you save your favorites while using Chrome, and then switched to Firefox or Safari, even on the same computer, you favorites will also be missing. To see your favorites again switch back to the same computer and browser you originally used to save your favorites. If you clear your cookies your favorites will be deleted with them and will not be recoverable. Use caution! A favorite import/export function is planned to be added to the viewer in the future.

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Show Most Recent Forecast Button

The Show Most Recent Forecast button is the default selection and provides the latest forecast that has been produced for each site. Forecasts are typically updated daily and sometimes multiple times per day. There may, however, be times when the system is delayed and forecasts are not available.

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Missing Forecasts

The development of this forecast system started at a few pilot sites but is continuing to expand with the plan of eventually achieving nationwide coverage. During phases of development and expansion, things may break, and the forecast in some areas could be delayed. If that happens, go enjoy a cup of coffee and then come back to check out the forecast at your favorite sites later! If the forecast doesn't update for multiple days, feel free to shoot us a message and let us know.

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Select Forecast Date Button

The Select Forecast Date button provides the ability to view previous forecasts back to the point the region was added to the viewer (as far as back as March 2016 for our initial sites).

The calendar that is displayed when clicking the Select Forecast Date button is color coded to indicate the most severe coastal change prediction for that day based on the current map view. In Regions view it will be the most severe coastal change prediction found at any site in the selected region. In Favorite view it will indicate the most severe coastal change prediction found across all of your current favorite sites (regardless of whether a site was a favorite at the time). Background colors on the calendar match those of the map pins and their meaning can be seen in the map legend. Hovering over a date will also detail the most severe coastal change prediction in a text popup. Grey dates that cannot be selected are dates for which a forecast is not available for your current map view. After selecting a date from the calendar, click on an individual pin to see the total water level forecast for that date.

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Map Controls

The map’s background tiles may be changed to display different map types (satellite, street, topographic, and oceanographic). Also, site pins for the various predicted coastal change types can be hidden and reshown. This is all done using the layer button in the top left of the map (stylized by three stacked sheets). Simply click the layer button to expand it and then choose different map types from the selection on the left and/or show and hide site pins using the buttons on the right. A faded button indicates that type of pin has been hidden. Clicking again will redisplay it.

The site details balloon that appears when a site pin is clicked can be removed from the map by clicking the X in the top right corner of the balloon. Click the pin again to redisplay it.

You can pan the map by clicking and dragging the map using any map area not occupied by a pin or balloon. The map may be zoomed using touch, a mouse scroll wheel, or the + and – buttons in the top left of the map. A map scale in the bottom right adjusts accordingly.

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Coastal Change Forecast Summary Tables

A coastal change summary table that lists the sites with predicted dune impacts is displayed below the map after you have selected a region of interest. Details include the number of impacted sites and the duration of forecasted impact. Sites are displayed in separate tables by the predicted type coastal change (Dune Erosion, Overwash, and Inundation) and each table may be expanded or collapsed by clicking on the table header. You can click a table row to select that site which shows the total water level forecast, similar to clicking on a site pin on the map.

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Forecast Time Series

The time series on the top right shows the total water level over the complete duration of the forecast. To view a small section in greater detail click and drag over the time period of interest. To return to normal zoom level double click anywhere in the time chart.

Zooming the time chart will stop the beach profile animation if it is playing. Starting the animation or moving the animation slider while zoomed will reset the zoom level.

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Beach Profile Animation

On initial display of the total water level forecast for a site the beach profile animation will run through one complete forecast before stopping. Playback may be started again by clicking the combination Play/Stop button found in the animation controls. The Stop button will halt the animation at the date and time the button was pressed. Pressing Play will resume animation from the currently displayed date and time. You may manually control the animation by dragging the slider control handle left or right along its track either while the animation is playing or while stopped. The position of the slider is shown by the black vertical bar in the time series graph which indicates the date and time the animation is currently displaying in the beach profile graphic. This date and time is also detailed in text below the slider.

The beach and dune fill color changes to indicate what type of coastal change is expected to affect the dune at the currently displayed date and time; details of what each color means can be seen in the chart legend.

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Want more information?

Click on the Information button below or use the circular i button in the top left of the viewer window.

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Have feedback?

For questions and feedback about the data presented within the viewer please contact the lead scientist Joseph Long.

For questions, feedback, and bug reports regarding the Viewer page please contact the web developer Richard Snell.

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Experimental Product

The Total Water Level and Coastal Change Forecast Viewer should be not be solely relied upon to make important decisions about hazard response. The U.S. Geological Survey provides these forecasts “as is” but assumes no legal liability or responsibility resulting from the use of this information.

This model output is experimental. There may be times where the updates are not available.

Potential Inundation - Site(s)

Potential Overwash - Site(s)

Potential Dune Erosion - Site(s)

No Predicted Events - Site(s)

Tell us how you use this viewer!

Let's get started!

On the map, click the colored circle representing your region of interest. When the map zooms into the selected region, click any of the individual pins and the most recent total water level forecast for that site will appear right here.

Find out more quick start info, help, tips, and tricks in our How To and FAQs page.

EXPERIMENTAL PRODUCT

The Total Water Level and Coastal Change Forecast Viewer should be not be solely relied upon to make important decisions about hazard response. The U.S. Geological Survey provides these forecasts “as is” but assumes no legal liability or responsibility resulting from the use of this information.

This model output is experimental. There may be times where the updates are not available.

Time of Peak TWL [UTC] Tide + Surge @ Peak TWL [m] Wave runup @ Peak TWL [m] Peak TWL [m] Dune Toe Elev. [m] Dune Crest Elev. [m]

Time Series and Beach Profile Legend

A single solid horizontal line colored navy total water level sum of tide, wind surge, and wave runup values
A light blue unbordered box 95% confidence based on spatial/temporal uncertainty in beach slope
A single dashed horizontal line colored in navy mean water level sum of tide, wind surge, and wave setup values
A single solid horizontal line colored in tan dune/berm crest elevation
A single dashed horizontal line colored in tan dune/berm toe elevation
Four boxes colored in tan, yellow, orange and red dune impact regime beach profile is colored to represent:
tan - dune/berm impacts unlikely
yellow - potential dune erosion
orange - potential overwash
red - potential inundation
Dune elevations may not be representative of current beach conditions
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