WestMarine.com

Forecast Maps


Pressure, wind, and rain.

White contours show the sea-level pressure in hPa (mb). White wind streamlines show the wind direction. The longer the streamlines and the closer together they are to each other, the stronger the wind. For absolute wind speed see the map below. Color-shaded areas show the rainfall in millimeters per hour. The maps show forecasts up to 8 days and they are updated every 6 hours.


Wind speed and direction.

Shaded areas show the wind speed in knots and wind barbs show the wind direction and speed. Long barbs represent 10 knots and short barbs 5 knots. The forecasts are shown up to 8 days and they are updated every 6 hours.


Wave height and direction.

Significant height of combined wind waves and swell and primary wave direction.The significant wave height is a measure for the wave height, and closely corresponds to what a trained observer would consider to be the mean wave height. Note that the highest wave height of an individual wave will be significantly larger. The maps show forecasts up to 7.5 days and they are updated every six hours.


Ocean currents.

Ocean current analysis. The analysis shows the ocean surface current direction and speed in knots. A new analysis is made approximately every 5 days. There are no data near the coastlines.


Sea surface temperature analysis.

Sea-surface temperature (SST) maps show the previous day's SST analysis and they are updated once per day.


About the data

The atmospheric model used for the weather forecast maps is the Global Forecast System (GFS). The model is one of the leading global Numerical Weather Prediction models in the world and it is developed by the National Oceanic and Atmospheric Administration (NOAA). The model is run four times per day (00, 06, 12, 18 UTC) at the National Centers For Environmental Prediction (NCEP).

New! Improved forecasts: On 14 January 2015, the National Centers for Environmental Prediction (NCEP) upgraded the GFS Analysis and Forecast System that will also reflect to our forecast charts of wind, pressure, rain, and sea surface temperature. Detailed information here.

Wave model used for the wave height and direction forecasts is the Wave Watch III. Similarly to GFS, the model is also run at NCEP four times per day.

The ocean currents charts use data from the Ocean Surface Current Analyses Real-time (OSCAR) project. The analysis is made approximately every 5 days. There are no data near the coastlines. This product is not operational and sometimes the update cycle may be more than 5 days.

Sea surface temperature (SST) data are from the Global Data Assimilation System (GDAS) that is also used to initialize the GFS model. SST analysis is produced once per day with a one-day latency, so the image displayed is from the previous day.