The effective version of the Modified Severe Hazards in Environments with Reduced Buoyancy parameter (i.e., modified SHERBE or MOSHE), detailed in Sherburn et al. (2016), is now available in beta form on the SPC Mesoanalysis page.
In observing the parameter’s trends over the past couple of days, I’ve noticed that there tend to be some “hot spots” associated with enhanced values of effective shear and low-level lapse rates. This is not entirely surprising, as our NARR values of effective shear did tend to show a low bias compared to the mesoanalysis values (hence, our term is weighted based on these lower values), and our dataset consisted entirely of low-CAPE cases (which inherently have less steep lapse rates). The omega field is also dependent on model setup and could have a different distribution in the RAP than what we saw in the NARR.
At any rate, I have been in touch with Rich Thompson at SPC about the potential of plotting the individual terms of the MOSHE on an internal page for us to monitor. This will allow for some troubleshooting to account for differences between the NARR and other analysis/forecast platforms. I could envision some changes to the relative weighting of terms or perhaps instituting some “caps” on the contributions of certain terms (similar to what is done in the STP/SCP) to limit false alarms while still maintaining the discriminatory skill of the parameter.
I’ll keep everyone up to date on the progress of the project to plot individual MOSHE terms. Until then, please monitor the real-time plots when you can and share any feedback with us. Thanks!