World Area Forecast System (WAFS) help
Overview
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.
Purpose
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 time steps 6 to 36 hours in 3 hour time steps and a sampling of levels 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:
- Turbulence (eddy dissipation rate) at flight levels 140, 180, 240, 270, 300, 340, 390 and 450. EDR values run frrom 0 to about 50 (EDRx100). Values above 15 are visualized.
- Icing Severity at flight levels 060, 100, 140, 180, 240, and 300. Icing values are categories for trace, light, moderate and heavy.
- 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 flight levels 100, 140, 180, 240, 270, 300, 340, 390 and 450. 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.
FAQ
What has changed recently?
The entire site was overhauled in October 2023. For information about the most recent updates, please see the change log.
How often do you update the website?
We fix critical bugs as soon as possible, and we deploy functional upgrades regularly. Please let us know if you find something that isn’t working.
Why is my URL 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.
Why can't I log in to my account?
Most features of AviationWeather.gov do not require an account. If you recently signed up for a new account, please check your email (including spam folders) for a confirmation email. Accounts are generally approved within one or two business days.
Where is the METAR page?
The interactive Graphical Forecasts for Aviation observation tab displays METARs along with other current data including surface fronts and radar imagery. To view METARs alone, click on the Layers button at the top right corner of the map and deselect items you do not wish to view. Decoded METARs can be displayed by enabling the "decoded METARs" option in the Map Options under the gear icon on GFA.
Raw and decoded textual METAR data can be displayed by selecting the Products dropdown and selecting METAR data.
Where is the Satellite/Radar page?
Satellite and radar imagery are available on the observations tab of the interactive Graphical Forecasts for Aviation, that displays surface observations, imagery, fronts, and more in one place. Satellite imagery is an optional layer available from the layer selector in the upper right corner of the map. To display satellite or radar imagery alone, deselect items on the layer selector to simplify the display.
How can I submit PIREPs?
Sign up for an account on our registration page, select PIREP Submit Access, 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.
Then watch your email in order to verify your address and then confirming your account. 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.
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 the right 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.
Where is the HEMS (Helicopter Emergency Medical Services) tool?
The HEMS tool has been integrated into the interactive Graphical Forecasts for Aviation. Click on the helicopter button in the upper right part of the map to switch GFA from general aviation mode into low-altitude mode, which offers similar features as the HEMS tool.
What happened to ADDS?
The ADDS static graphics were phased out and replaced with the Graphical Forecasts for Aviation, which offers greater flexibility and configurability; some static graphics continue to be available for decision support. The ADDS Text Data Server has been succeeded by the Data API. Please let us know if you need assistance with the migration.
How can I display list of METARs and/of TAFs? What about decoded products?
The METAR and TAF data pages provide access to raw, tabular, and decoded output that automatically refreshes every five minutes. The page is designed for quick lookups and printability.
Where is the Text Data Server? How do I download METARs?
The Text Data Server was discontinued and has been replaced by the Data API. The new data offerings are more flexible and provide more data. Interfaces designed for greater compatibility with the Data Server to ease the transition as well as cache files to retrieve many reports at once are also available.
How do I access data for previous dates?
The METAR data page displays up to the previous 96 hours of observations. The Archive View allows viewing nearly all products on the site as they were presented for up to the past two weeks. For data more than 14 days old please reference the resources available on bottom of the Archive View page.
Data appears to be missing. Where can I find more information?
Automated status information and the latest announcements can be found on the status page
Why is a particular station not reporting?
The site generally displays all observations within a minute or two of being reported as we receive it. Individual station outages are usual indicative of a problem at the source. AWC does not maintain weather stations or observing platforms.
What do all of the map symbols indicate?
A full listing of map symbols is available.
Why is the map dark?
Dark mode is automatically applied based on systems settings. Selecting the person icon in the upper right and toggling the switch to the left disables this mode.