Fathym Forecaster Evaluation Guide
What is Fathym’s Forecast API?
The Fathym Forecaster is a robust, feature-rich API that offers a powerful suite of weather and surface condition forecasting application development tools. The API provides forecasting capabilities over freely chosen locations in both space and time.
A wide array of user-selected weather variables is available for query, together with highly specialized surface condition variables derived from statistically based machine learning models. Forecasts from any combination of variables can be integrated into any imaginable customer application.
The Fathym Forecaster is a valuable addition to many data applications.
What data variables are available?
In addition to the wide array of user selected HRRR and GFS weather model variables that users can query; the API delivers a unique suite of highly specialized forecast variables derived through statistically based machine learning models. These derived variables include road temperature, road state/condition, and a delay risk factor for destination arrival estimates.
Derived Variables
- Surface/Road state condition
- Road temperature
- Delay Risk (origin-destination)
Weather Variables
- Ambient temperature
- Precipitation amount
- Precipitation type
- Precipitation rate
- Wind direction
- Wind speed
- Wind gust
- Barometric pressure
- Relative Humidity
- Dew point
- Irradiance
- Snow depth
- Cloud Cover
What is the forecast’s geographic coverage?
Forecast coverage is global, with higher resolution (3-km) coverage available over the continental United States (CONUS). Global coverage is available at a 13-km resolution. If you’re looking for higher resolution coverage over a certain region, contact us for a custom quote.
What is the forecast window?
The Fathym Forecaster provides a 16-hour forecast window for continental US (CONUS) geography covered by the HRRR weather model and a 120-hour forecast window with the GFS global weather model. The API also offers the capability for 90-day historical queries. All forecasts are time-interpolated to the nearest second, when clients just cannot wait for the hourly updates offered by other forecast APIs.
The Fathym Forecaster provides a 15-hour forward forecast window together with the capability of 90-day historical queries.
Which points are available for forecasts?
The Fathym Forecaster offers developers powerful weather forecasting capabilities over freely chosen locations across the globe, with any combination of variables. Potential use cases include, but are not limited to, individual point forecasts through time, as well as individual forecasts for large sets of locations, such as all Sam’s Club locations in the contiguous US. Also, dynamic routing features can extend forecast capabilities to user-selected transportation routes, supporting many potential applications targeting commercial transportation and travel where road and surface condition predictions impact planning and logistics.
In general, a query can be for any forecasted variables at any set of points. Querying thousands of points (e.g., along an interstate trucking route, or the locations of a set of retail establishments) is not only possible, but fast — responses in about one second are possible. For the purpose of forecasting along routes, a route is a list of points in space and time.
Geospatial Capabilities
- Point Forecast
- Multiple point forecast
- Route/alternative route forecast
What are the available outputs for the API?
The Fathym Forecaster API is a high-performance RESTful API that can be used to obtain forecasted values for a variety of variables at any set of points in space and time. When querying the API, the results you will receive back are in JSON. Additionally, maptile output is compatible with all industry standard map overlay APIs such as Azure Maps, Google Maps, and OpenStreetMap.
How accurate is the data and is there data verification?
Fathym’s verification studies have shown the following:
Air Temperature Forecast Accuracy
+/- 1.0°C of a given observation over 18 hours
+/- 2.0°C beyond 18 hours
+/- 2.5°C in peak heat
Road Temperature Forecast Accuracy
+/- 1.5°C of a given observation over 18 hours
+/- 2.5°C beyond 18 hours
+/- 2.5°C in peak heat
Fathym’s road-specific variables are carefully and continuously validated using third party and independent sources such as
weather stations.
Fathym validates overall forecast accuracy by cross-checking 60,000 points every hour as observed by worldwide
weather stations (1,000 stations, 15 hours of forecasts, 4 times per
hour).
Fathym validates road temperature forecast accuracy by cross-checking 5,000 points per day against stations with infrared
cameras pointed at roads in various geographies.
Fathym has done studies comparing road state conditions to human-labeled Department of Transportation webcam images, establishing a
greater than 90% accuracy of forecasting surface conditions.
The net effect of all this validation over time will be to train the machine learning model, aiding in increasing accuracy and granularity of data, which will yield continual improvements.
Is documentation available?
Yes, the API is fully documented. You can find documentation here: https://support.fathym.com/docs/fathym-forecast-api
Is support available?
Yes, customers can contact support staff who will respond within hours on weekdays. Email us at support@fathym.com.
