At 2005 UTC, we had a storm merger east of GLD. THe lead supercell was starting to produce a moderate low-level meso and I decided to update my TOR probabilities to start at 50% which happens to be my personal tornado warning threshold. The environment was marginally favorable for meso induced tornadoes and pretty favorable for supercells in general. So my impression of the environment was not great. There were no spotter reports despite potentially good coverage. Thus I kept my tornado warning probabilities just above my threshold and not higher.

Greg and Liz were wondering what made me set a 50% probability of a tornado as a mental threshold of a tornado warning. I replied that I felt that I wanted to be more than half confident that a tornado would occur inside my threat area as it expanded and moved downstream. However I’ve been issuing tornado warning proababilities well before I reached the 50% threshold.

I found another challenge in maintaining my storm motions between threat types for the same storm. I became preoccupied with updating the TOR threat area and storm motion as the storm turned more to the right. After I updated the TOR threat area, I became distracted by an out of date hail threat area with the left mover. However, I should’ve updated the storm motion for the hail threat area for the same storm I had followed with the TOR threat. Since I didn’t, the two motions, and subsequent threat swaths were in totally different directions.

Jim LaDue (EWP Weekly Coordinator-in-Training)

Liz, Greg and I are tracking a pair of storms northeast of GLD. The lead storm is a supercell while the trailing storm is more obviously multicellular consisting of ordinary cells. We’re raising many questions about the probability warning guidance issue.

Questions include:

• Liz asks how does she maintain some kind of connection with her user? Greg counters that the warning meteorologist should be separated from the user. Afterall there are many types of users, each with their own thresholds for warning. There will still be a need for some kind of binary product that the lowest common dissemination method (e.g., NOAA wx radio) can still transmit. Liz is not comfortable with losing the connection with the user. Greg says someone will likely be filling this role.
• Can we set a threshold probability in the prob warning tool for which when passed, the tool flags the swath as an official binary warning?
• Can a forecaster set his/her own threshold warning probability?
• Liz wonders if we can save each forecaster’s warning thresholds so that we can see how each one thinks? My 50% is your 30%, for example. This process may shed light on forecaster differences (biases) in the assessment of probabilities.
• Can metadata be added to each threat area ID so that any input not easily translated to grids can be added? Greg suggested that it could be a blog for each threat area. We’re thinking that metadata could include special call-to-action statements, forecaster reasoning, adding context to the event and others.
• Liz wonders how we could translate any of this metadata to something that is consistent with text in current warnings.

Greg would like to have the individual threat area translucent overlays (H,W,T) to be separated out so that we can toggle each threat area type on and off.

Jim and Liz would like product legends to be simplified. Hard to get time and elevation cut/height to stand out.

Jim would like to be able to change from irregular polygon to ellipse in mid process.

Jim LaDue (EWP Weekly Coordinator-in-Training)