NOAA/CIMSS ProbSevere model at Week 2 HWT

The second week of the 2014 HWT is underway, with visiting forecasters evaluating a number of GOES-R products, including the new NOAA/CIMSS ProbSevere model. Forecasters are learning how to use this product today within their warning operations.

The ProbSevere model is probabilistic guidance from a statistical model, which fuses together data from the Rapid Refresh NWP model (RAP), growth rates in GOES-derived cloud products, and Multi-Radar Multi-Sensor (MRMS) Maximum Expected Size of Hail (MESH). Storms are identified and tracked in both satellite and radar imagery. Time trends (normalized vertical growth rate and glaciation rate) are extracted form satellite objects/storms, and shared with overlapping storms, present on radar. The probability of severe in the near future (~0-60 min) is computed using these satellite time trends, the MESH, and MUCAPE and effective bulk shear derived from the RAP.

This storm in south-central Iowa had a 90% probability of severe prior to producing a 64mph wind report. All of the surrounding storms had probabilities generally less than 30%.

A storm that developed in the warm sector also had a strong probability of severe well before 2" hail was reported in north-central Illinois.

With sampling turned on (see image below), we can see the AWIPS-II readout for ProbSevere. The probability of severe is of course displayed, as well as the values of the individual predictors. If the satellite growth rate predictors read 'N/A', that means that the storm is not discernible in satellite imagery, and thus growth rates can't be computed. Work is ongoing to try to associate mature satellite features with individual storms on radar. ProbSevere will still operate with radar+NWP, however, lead time to some severe hazards may not be as great as when the satellite growth rates are incorporated.

-Cintineo