So now the multicell is beginning to accelerate southeast and it’s leaving their threat area out. Brian, Cynthia and Bill think the hail threat is small now. They’re thinking of adding a wind threat using the same threat area already done for hail. BTW, the Brian’s got the hail threat area elongated along the line axis encompassing multiple cells. We’ll stick with hail for now.

Somehow the valid time hail threat went to zero.

Greg asked whether there needs to be changes in how probabilities are computed. Brian wonders if there should be a membership function? What should the ending probability be? Craig thinks the ending probability will be below his warning threshold. Craig wonders how hard it would be for users to understand that some low probability swaths will not be associated with warnings.

Jim LaDue (EWP Weekly Coordinator, 5-9 May)