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 GemAI, NOAA GEFS and historical data (ERA5 Reanalysis).
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.
Historical Events
You can also look retroactively to see whether an event happened in the past usingdata_timeseries . For event types, you'll get either a 0 or 1 for probability, 1 being the event happened. And for date-like quantities, for example, first freeze for winter 2024, you should set start=2024-06-01&end=2025-05-31.
Standard Event Types
| Event Type | Description | API name |
|---|---|---|
| 8 Day Precip | 8-day cumulative precip > 15mm | 8_day_precip |
| 10 Day Precip | 10-day cumulative precip > 15mm | 10_day_precip |
| 11 Day Precip | 11-day cumulative precip > 20mm | 11_day_precip |
| 3 day mean below 15F | 3-day mean minimum temperatures < 15F | 3_day_mean_below_15F |
| Cold Spell | 3 consecutive tmin days below the seasonal 10th percentile | cold_spell |
| Cold Period | daily extreme cold day; tmin < 2nd percentile | extreme_cold |
| Elevated Fosberg FWI | FFWI exceeding the 95th percentile. Quantifies potential fire behavior severity based on forecasted weather conditions | elevated_fosberg_fire_weather_index |
| Extreme Cold | Minimum temperature below the 2nd percentile | extreme_cold |
| Extreme Heat | Maximum temperature above the 98th percentile | extreme_heat |
| Extreme Precipitation | Daily precipitation above 98th percentile | extreme_precipitation |
| Extreme Wind 100m | Daily average windspeed (100m) above the 98th percentile | extreme_wind |
| Frost | Minimum temperatures below freezing | frost |
| Heat Wave | 3 consecutive days of maximum temperature above the seasonal 90th percentile | heatwave |
| Low Solar | daily total solar insolation < seasonal 30th percentile | low_solar |
| Low Wind | daily average wind speed (100m) < 5.5 m/s | low_wind |
| Low Wind and Cool | day with 100m wind below 5.5 mph and tmin < 30th seasonal percentile | low_wind_and_cool |
| Low Wind and Warm | day with 100m wind below 5.5 mph and tmax > 70th seasonal percentile | low_wind_and_warm |
| Renewable Drought | combination of low wind speeds (100m < 5m/s) and low incoming solar (< 20th seasonal percentile) | renewable_drought |
| Warm Period | daily tmax above the 70th percentile | warm_period |
| Wildfire Risk | risk of wildfire; defined as: daily average RH below the 2nd percentile and wind gusts above 25 mp | wildfire_risk |
| Windy Day | daily maximum wind gust > 25 mph | windy_day |
User Interface
Custom variables and Event Types are available for display in the following views:
https://www.loom.com/share/b2f2774f80d74ae789f43f128e983ce1?sid=f366a187-6233-43ce-98c4-9b271f4710f9
Use endpoint /upload_fileto create a new definition
Use endpoint /list_custom_quantitiesto get a list of custom quantities uploaded to your account
Check out the video at the end of this section to walk through the details.