We are just beginning to play around with FB here at RNK, and we are seeing some of the undesired issues others have brought up already with too much potential for FZRA for MaxTwAloft barely above 0, but I guess we can remove the PotFZRA grids if we feel strongly there really is no potential. Of greater importance is the concern about using temperature thresholds in Step 4 for the Rain/Snow-only scenarios in that this is entirely dependent on Tw and wiht changing airmasses and also the terrain in our area we often have varying T thresholds (and thus will current tools we set the thresholds for different edit areas). However the best approach is for all such tools to use Tw, so that it simply uses your hourly T and Td grids to calculate an internal Tw and use <33 F for all snow, and >34 for all rain (so 33-34 is a mix). Various studies might nit-pick about these ranges should be. Or at the very least have a default set for Tw of 33 as the threshold and folks can adjust that if desired, but the more we can get away from user-adjustable values/sliders the better.
As an aside, I saw some earlier posts about the desire to get FB to work with edit areas and not sure if there was a response on that. That is a strong need here, mainly from Step 4 onward.
Thanks!
Steve Keighton
