Get Full Government Meeting Transcripts, Videos, & Alerts Forever!
Get email alerts on the Public Safety Avalanche topic
No spam. Unsubscribe anytime.
Mono County forecaster: warmer winters are producing more destructive 'rain‑on‑snow' avalanches that threaten roads and infrastructure
Summary
Avalanche forecaster Sue Burack told the board that warming temperatures and rain‑on‑snow events are creating more destructive avalanches that can reach county roads; she outlined weather‑station upgrades, mapping and a notification protocol and recommended targeted road closures when hazards threaten infrastructure.
Sue Burack, who leads Mono County’s avalanche forecasting work, briefed the board on changes in avalanche behavior and program improvements intended to protect county roads and residents.
Burack said the county now sees more mixed or rain‑on‑snow avalanches that can run farther and carry more destructive force than traditional dry‑snow slab events. “We’re seeing a different type of avalanche occur … much more rain on snow, and that create[s] a different type of avalanche that can run out farther,” she told supervisors. She described two county weather stations (Twin Lakes and Magee Mountain), plans to relocate a station to a more sheltered site and the addition of a snow‑depth gauge this summer.
Burack explained the county uses road‑specific hazard ratings and disseminates plain‑language warnings and recommendations to road crews and the sheriff. ‘‘If I determine that the avalanche hazard has risen to the point where an avalanche could reach the road, then I will issue a recommendation to close these certain roads,’’ she said. She also described a GIS mapping project that identifies frequently observed avalanche paths and provides emergency responders with visual reference maps.
Board members asked about triggers for public notifications; Burack said staff is exploring using the county’s Genesys notification system to push geographically targeted alerts and that work with the sheriff and IT is underway. She noted that recent burn scars and exposed rock reduce friction on runout terrain and that model runs show an increased likelihood—on the order of 20–30 percent in some runs—of avalanches reaching roads in affected areas.
The presentation covered local examples (Magee Mountain, Twin Lakes, Crowley Lake Drive) and the wider implications for spring runoff, streamflow and fire hazard if snowpack continues to decline. Supervisors thanked Burack for the update; no formal action was required, but the board asked staff to continue work on notification triggers, station relocation and GIS mapping.
