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As we enter what appears to be another multi-day severe weather event, I want to take a moment to caution people against taking composite parameters at face value from convection allowing models. And, yes, what follows is slso s reminder to me.
As we enter what appears to be another multi-day severe weather event, I want to take a moment to caution people against taking composite parameters at face value from convection allowing models. And, yes, what follows is slso s reminder to me.
In CAMs, models explicitly simulate some of the convective processes, allowing for numerical-based responses/feedbacks into the near-storm environment. This includes modifying near-storm wind fields and moisture fields.
A consequence of this is that composite parameters (such as STP) can max out in bullseyes in the immediate vicinity of convection. This can lead to the false impression of a more favorable larger/mesoscale environment than actuall exists.
This also leads to widespread PDS Tornado soundings in SHARPpy.
The problem is that all of the studies that determined/calibrated the composite parameters were based on the background/larger-scale/mesoscale environments -- not the immediate near-storm environment.
We do not know what an impressive STP value is in the immediate inflow of a weak/'ordinary'/massive supercell. This is at least one of the reasons the SPC Mesoanalysis is still run at 40-km and not say 3 -- we want to be sure to sample the environment and not individual storms.
So, my unsolicited advice -- and your mileage will vary -- is to evaluate composite parameters (and soundings) in the non-contaminated environment and not in the vicinity if model convection. (Easier said than done, I know.)
Oh, and get off my proverbial lawn, too. 😉
Oh, and get off my proverbial lawn, too. 😉
