World Area Forecast System (WAFS) help


The NWS Display of WAFS Grids for turbulence, icing, cumulonimbus, cloud, and wind speed is a graphical representation of the grids issued jointly by the World Area Forecast Centers (WAFCs) in the United States and United Kingdom. These grids are sanctioned by the International Civil Aviation Organization (ICAO) and the Federal Aviation Administration (FAA) for use in flight planning. They are available for various levels from forecast hours 6 to 36, in three hourly time steps, in GRIB2 format. This product provides users a way to display the grids at all levels and time steps via a web page with an interactive GIS display. Users are able to overlay multiple levels and forecast parameters and loop through the time range.

For more guidance on the grids themselves, use the Met Office information for the New WAFS data sets.


The purpose of the display is to provide a rudimentary way to visualize the WAFS Grids of turbulence, icing, cumulonimbus, cloud, and wind. This visualization is intended for users who need to check that their own display software is correctly decoding the GRIB2 files and properly displaying the gridded data in graphical format. It is also intended to serve as a common reference point for the NWS and its customers when discussing the WAFS forecast data.

The intended users are software vendors that design flight planning software, plus airline dispatchers and air traffic managers. The display will be available 24/7. It will be updated 4 times per day, following the completion of each GFS model run. It is also intended to serve as a common reference point for the NWS and its customers when discussing the WAFS forecast data.

The WAFS data display is a visualization of the WAFS aviation grids that allows users to view the fields on a global display. The gridded data is displayed as a multicolored image with a color coded legend to relate the colors to numerical values. The images are provided for each time step and level in the WAFS Grids displayed on a map background depicting the world’s countries and oceans. Additionally a map background of Flight Information Regions can be toggled on in the map options. The grids include:

  • Clear Air Turbulence (CAT) at 200, 250, 300, 350, and 400 mb. CAT values run frrom 0 to about 35. Vaues above 5 are visualized.
  • In-Cloud Turbulence (InCldTurb) at 400, 500, 600, and 700 mb. InCldTurb values run from 0 to ~.035. Values above .005 are visualized.
  • Icing at 500,600, 700, and 800 mb. Icing values run from 0 to about 1. Values above .7 are visualized.
  • Cumulonimbus (CB) horizontal extent and tops. CB horizontal extent values run from 0 to ~1 and reflect the amount of grid cell covered by CB. Values above .3 are visualized.
    CB tops values run from 0 to about 60,000 feet and show max tops of CBs. Values above 30,000 feet are visualized.
  • Wind Speed at 300, 400, 500, and 600 mb. Wind speed values run from 0 to about 170 knots. Values above 60 knots are visualized.

Select which layers are visible on the map with the layer selector button on the top right corner of the map. Change which parameters are displayed in the map options, and select Looping to automate scrolling through the 36 hour forecast. The time slider on the bottom displays what time the forecast is valid and product labels on the top left corner display what is visible on the graphic.

World Area Forecast Internet File System (WIFS)

WIFS is the World Area Forecast System (WAFS) Internet File Service, a service provided by the United States to support international flight operations. An account is required to use WIFS. For more information, including Eligibility Requirements, go to the Description section and review the WIFS Users Guide (Section 4) located in the Documents section.

Approved access is required to access WIFS data. If you have an account, access WIFS data here.

What's New on the Website

This is a brand new page...everything is new!

Archive of old "What's New" here, so it doesn't clutter the page.


Why is my link not working?

As part of the upgrade to the site, some pages were consolidated and some URL's have changed. Check out the link conversions to find what you are looking for. If you are still unable to find the information you are looking for, submit a question using the envelope in the top right.

Where is the METAR page?

You can view the METAR data by using the Products dropdown and selecting METAR data. The interactive Graphical Forecasts for Aviation map also displays METARs, under the observations tab. To view METARs alone, click on the Layers button at the top left corner of the map and deselect items you do not wish to view. You can view decoded METARs by checking the "decoded box in the Map Options under the gear icon on GFA. Here is a link to the observations tab: GFA Observations tab.

How do I submit PIREPs?

Sign up for an account on our registration page, or using the Contact Us dialog under the envelope at the top right corner of the screen. Select "PIREP Access" as the category, and be sure to include your airmen’s certificate number or affiliation with an airline, flight school, government or military organization for validation purposes to streamline the process. Accounts are validated via the FAA Airmen Inquiry.

Once you have an account and are logged in, select "Submit a PIREP" from the Tools dropdown and fill out the form. For more information on PIREP submit, use the link at the bottom, or click here.

Where do I submit questions/comments?

Click on the envelope button at the top right corner of your screen to fill out the webmail form. There are some new features and there will be some initial bugs. Please don't hesitate to let us know. We run a deployment of functionality upgrades every month. Critical bugs will be fixed as soon as possible.

Why can't I log in to my account?

You will need to log in and/or have correct permissions. If you do not see a confirmation email after registering, please check your spam folder. Please contact us if further information is required.

How do I access the Flight Path Tool?

The flight path tool is now embedded into the interactive Graphical Forecasts for Aviation map. Click on the route button along theright side of the map to open the display. Enter the airports to navigate, and select the product you wish to display from the dropdown. Watch a video on how to use the cross sections here.

Help page links