Tornado probability (%).
GribStream
spctor4hr
SPC HREF calibrated tornado probability is a specialized convective-hazard field from the Storm Prediction Center post-processing suite. It expresses tornado risk over four-hour windows, which is useful for operational situational awareness before warnings exist and after broad outlook categories need to be localized.
The calibrated tornado method combines storm-scale HREF signals, including updraft-helicity information, with a larger-scale severe environment. SPC's calibration framework relates those paired signals to historical report frequency near each grid point and time window. That makes the product a direct probability layer for decision support rather than a raw model ingredient.
Use this dataset for severe-weather dashboards, emergency-management prioritization, operations centers, utility and transportation risk screening, and applications that need a machine-queryable tornado-risk signal. It should be interpreted with SPC Hail 4h, SPC Wind 4h, HRRR, and official SPC outlook and warning products.
TORPROBTornado probability (%).
| Level | Info | Horizon | Introduced | Selector |
|---|---|---|---|---|
surface |
prob >0 |
4h-24h | 2 days ago |
{"name":"TORPROB","level":"surface","info":"prob >0"}
|