search

sharppy / SHARPpy

Sounding/Hodograph Analysis and Research Program in Python
https://sharppy.github.io/SHARPpy/index.html
Other
216 stars 112 forks source link

Average hail size not used in SARS #142

Closed jscheel closed 5 years ago

jscheel commented 5 years ago

https://github.com/sharppy/SHARPpy/blob/3b04a9dedaff51606af99393aeef1196b7b23189/sharppy/databases/sars.py#L319

It looks like the average size is calculated but not used anywhere. Should this data be provided somewhere?

wblumberg commented 5 years ago

My thought is no. I believe that calculation code left over from when SARS was only run for hail and had its own individual inset, and the calibration for this feature isn't available to us (https://www.spc.noaa.gov/publications/jewell/sars.pdf). SPC's forecast mission has often been to discriminate between SIG and NON-SIG hail (<2"), and SARS currently does this via a calibrated probabilistic output. SPC has cautioned us about not deriving too much information from SARS given that there's a lot of overlap in the parameter space and the training dataset may be undersampling the true parameter space.

jscheel commented 5 years ago

Ah, that makes sense. If I understand you correctly, calculating a hail size here would be akin to re-assigning uniform weights to the outputs of weighted parameters and then averaging them. So, this is good to remove then?

wblumberg commented 5 years ago

Not quite. The primary reason is that we're trying to follow what SPC has and they haven't used this feature in some time now - there are other outputs from SARS that meet their forecasting mission better that are included in the GUI. I guess it could be removed, but doing so or considering it hasn't been a high priority given that this calculation isn't computationally expensive compared to other code and was in the original code they provided to us.