Hurricane icons persist when no other layers are loaded (v0.2.24)

[PhillipsOwen]

The layer of hurricane icons remains although there are no other layers on the UI. steps to reproduce:

• open the filter dialog
• hit the search button for tropical runs (no other filter selections made)
• select a observation layer
• select an observation point
• note that the hurricane track has appeared with the observation layer selected (see the first image below)
• remove the observation layer
• note the hurricane icons remain (see the second image below)

[lstillwe]

Propose closing this since hurricane layers are now a separate card that you can hide, show and delete?

[PhillipsOwen]

that sounds reasonable. closing...