I want to walk you through a thought experiment that I had today during this event in the Panhandle region of TX/OK, as it enters the southeast corner of the Amarillo forecast area. From the Amarillo forecast area, highlighted in white in GIF one, the environment becomes increasingly more unstable. The storm in question is moving through the bottom right corner of the forecast area moving southwest to northeast.
Here is the question I want you to ponder. Would you warn on this storm with only the environmental information and the two satellite products provided in GIF one? We are assuming we don’t have radar data right now.
GIF one: CH-2, Red Visible GOES-16 1 minute imagery from the MESO-1 Sector.
Okay, I know, we would normally have the prob-severe tool, and lightning data. But I didn’t look at it. So what was my answer? A hard maybe because I would want to make it a group discussion with the other forecasters on shift. My vote would be to warn, but with the lack of information, I would have no problem waiting for a storm report or some other data source.
Now, ask yourself the same question. Would you warn on the cell moving through the bottom right corner of the forecast area? But this time, you have access to the OCTANE suite of products.
Have an answer? Let me share some further information I collected from the developer before we share out answers.
I discussed with the developer what correlations existed between the OCTANE speed and divergence products and the severity of a storm. None had been established yet and the rule of thumb I was left with was that the storm top diverge observed in OCTANE speed products were about 30% to 50% less than the radial velocity divergence signals we normally use with data from WSR-88D. So where we measured a divergence speed of 40 kt in the OCTANE Speed product, the radar velocity should be around 50 to 80 kt, which could definitely support severe hail.
So, I said I would have been comfortable warning with just this additional OCTANE information. That said, a discussion may still be held, but I think this would be the information that gets the warning out more quickly. If I had a table of correlated values and severity? My confidence would sky rocket!
-Kilometers
Update: There was a storm report generated from a mesonet observation that observed a wind speed of 78 mph.
