The NOAA/CIMSS ProbSevere Model is a statistical model that combines, NWP environmental conditions, satellite tracking and growth rates, and radar tracking and storm intensity to predict a developing storm will first produce severe weather in the near future (0-60 min). The NOAA/CIMSS ProbSevere model is being demonstrated to National Weather Service forecasters at 2014 Big Spring Experiment at the Hazardous Weather Testbed. NWS forecasters are encouraged to evaluate the ProbSevere model output as a means to increase confidence and lead-time in issuing initial severe warnings on developing storms. Today the weather is rather quiet across much of the country. A strong storm developed in southwestern Virgina and the evolution of the ProbSevere model performance on this storm is highlighted below. Of note, this storm achieves high probabilities and as of 2030 UTC, has been the only storm over CONUS today to achieve appreciable ProbSevere values.
|Figure 1. The NOAA/CIMSS ProbSevere at 1950 UTC 5 May 2014–the first time the model produced probabilities above 50%. Radar data is not yet seen in this display as a domain switch was in-progress within HWT.|
The NWS office in Blacksburg, VA issued a severe thunderstorm warning at 1952 UTC. The following two figures show the continued increase of NOAA/CIMSS ProbSevere probabilities.
|Figure 2. NOAA/CIMSS ProbSevere at 1954 UTC 5 May 2014–probabilities are now 80%+.|
|Figure 3. NOAA/CIMSS ProbSevere at 2006 UTC 5 May 2014 now exceeds 90%.|
This storm went on to produce severe hail (1.00″) at 2009 UTC–19 minutes after the initial ProbSevere > 50%. While this storm was not located in the a CWA of focus for this afternoon, forecasters are using this storm to gain confidence in the ProbSevere model and ask questions about some of the technical details of the model.