There are scenarios where a weather condition or hazard is based on a cumulative value or a combination of multiple variables. Salient provides user-defined custom variables and event types to support more complex weather definitions. This capability is limited to Salient GEM and NOAA GEFS.
Custom variables are defined with a basic rolling aggregation (sum, mean, minimum, maximum) over some period of time. Examples of custom variables include "mean daily temperature over 5 days" and "accumulated daily precipitation over 3 days”.
Event types are user-defined definitions consisting of one or more native or derived variables and corresponding risk thresholds. Salient provides default definitions for common event types like Extreme Heat and Renewables Drought.
Standard Event Types
| Event Type | Description |
|---|---|
| Cold Spell | 3 consecutive days of minimum temperature below the seasonal 10th percentile |
| Heat Wave | 3 consecutive days of maximum temperature above the seasonal 90th percentile |
| Extreme Cold | Minimum temperature below the 2nd percentile |
| Extreme Heat | Maximum temperature above the 98th percentile |
| Extreme Precipitation | Daily precipitation above 98th percentile |
| Extreme Wind 100m | Daily average windspeed (100m) above the 98th percentile |
User Interface
Custom variables and Event Types are available for display in the following views:
Use endpoint /upload_fileto create a new definition
Use endpoint /list_custom_quantitiesto get a list of custom quantities uploaded to your account
Custom Variable Definition
List of parameters that need to/can be included in your custom variable definition. Parameters in bold are required.
| Parameter | Description |
|---|---|
| name | Name referenced in API calls where parameter is “custom_quantity”. The default behavior is to remove underscores and capitalize the first letter when displaying in the user interface, e.g. name = weekly_precip will be displayed as Weekly Precip. |
| description | Longer form text describing the custom quantity. This text is displayed in the user interface to provide additional information. |
| variable | GEM or GEFS forecast variable name |
| field | Either vals or anom. Defaults to vals |
| units | Either SI or US. Defaults to SI. Not applicable for event types |
| rolling_window | Duration of rolling window to perform a temporal aggregation. Defaults to 1. |
| rolling_aggregation | Operation to perform with the rolling window. Can be any of: mean, sum, min, max. |
Additional Parameters for Custom Event Type Definition