EXPERIMENTAL NEARSHORE WAVE PREDICTION SYSTEM

SIGNIFICANT WAVE HEIGHT (FT)

Average height (in feet) of the highest 33% of the waves.  Individual waves may be twice the significant wave height.
12 Hour Forecast 15 Hour Forecast 18 Hour Forecast 21 Hour Forecast 24 Hour Forecast
27 Hour Forecast 30 Hour Forecast 33 Hour Forecast 36 Hour Forecast 39 Hour Forecast
42 Hour Forecast 45 Hour Forecast 48 Hour Forecast 51 Hour Forecast 54 Hour Forecast
57 Hour Forecast 60 Hour Forecast 63 Hour Forecast 66 Hour Forecast

69 Hour Forecast
72 Hour Forecast 75 Hour Forecast 78 Hour Forecast 81 Hour Forecast 84 Hour Forecast
 
87 Hour Forecast 90 Hour Forecast 93 Hour Forecast 96 Hour Forecast  

 

PEAK WAVE PERIOD AND DIRECTION

Time period (in seconds) between successive wave crests or troughs.  Arrows point in the direction toward which waves are moving.

12 Hour Forecast 15 Hour Forecast 18 Hour Forecast 21 Hour Forecast 24 Hour Forecast
27 Hour Forecast 30 Hour Forecast 33 Hour Forecast 36 Hour Forecast 39 Hour Forecast
42 Hour Forecast 45 Hour Forecast 48 Hour Forecast 51 Hour Forecast 54 Hour Forecast
57 Hour Forecast 60 Hour Forecast 63 Hour Forecast 66 Hour Forecast 69 Hour Forecast
72 Hour Forecast 75 Hour Forecast 78 Hour Forecast 81 Hour Forecast 84 Hour Forecast
 
87 Hour Forecast 90 Hour Forecast 93 Hour Foreacast 96 Hour Forecast  

CURRENT VELOCITY
 Horizontal surface current speed and direction.  Streamlines show current direction.  The current speed is indiciated by the different colors.
12 Hour Forecast 15 Hour Forecast 18 Hour Forecast 21 Hour Forecast 24 Hour Forecast
27 Hour Forecast 30 Hour Forecast 33 Hour Forecast 36 Hour Forecast 39 Hour Forecast
42 Hour Forecast 45 Hour Forecast 48 Hour Forecast 51 Hour Forecast 54 Hour Forecast
57 Hour Forecast 60 Hour Forecast 63 Hour Forecast 66 Hour Forecast 69 Hour Forecast
72 Hour Forecast 75 Hour Forecast 78 Hour Forecast 81 Hour Forecast 84 Hour Forecast
 
87 Hour Forecast 90 Hour Forecast 93 Hour Foreacast 96 Hour Forecast  


The graphics above are produced by the Florida Keys National Weather Service using wind forecasts from our local marine duty meteorologists, output from the Simulating WAves Nearshore (SWAN) wave model, and output from the Real Time Ocean Forecast System. You may view more information about SWAN and output from other Southern Region coastal offices at the Southern Region SWAN page.  The graphics above show 3-hourly forecast outputs.  The boundary conditions are provided by the NOAA WAVEWATCH III model.

Note: The SWAN output is used as guidance to produce WFO Key West marine forecast. It is only experimental and it may differ from the official forecast. For the official marine forecast  graphics go to : WFO KEY Official Marine Forecast Graphics.

SWAN accounts for the following physics:

  • Wave propagation in time and space, shoaling, refraction due to current and depth, frequency shifting due to currents and non-stationary depth.
  • Wave generation by wind.
  • Three- and four-wave interactions.
  • Whitecapping, bottom friction and depth-induced breaking.
  • Dissipation.
  • Wave-induced set-up.
  • Propagation from laboratory up to global scales.
  • Transmission through and reflection (specular and diffuse) against obstacles.
  • Diffraction.



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.