HPWREN relay site

HPWREN Relay Site Damaged by High Winds

February 18, 2018

On January 28, 2018 a significant Santa Ana condition impacted San Diego County, and with it came substantial damage at about 10:08 AM to the Big Black Mountain relay site east of Ramona. The relay supports a link to the HPWREN backbone site on Mount Woodson, and connects a firefighting agency site. A set of 360 degree cameras, a PTZ camera, and a meteorological sensor set are also mounted to the solar-powered relay.

This image shows the intact site.

This photo illustrates the damaged tower.

A close up of the fallen and bent tower.

The weather sensor wind data had been collected on a once-per-second rate. Figure 1 shows the per-minute maximum wind speeds for 21 days prior, on occasion exceeding 90 miles per hour. Figure 2 shows the once-per-second medium wind speed for 15 minutes prior to the site failure. The average wind direction in Figure 3 is also based on once-per-second data of the site's last 15 minutes. Figure 4 shows the multi-day relative humidity levels, with Figure 5 more focused on the more recent time period prior to the outage, based on per-minute data.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Significant camera shaking can be viewed via the camera animations prior to the incident:

PTZ: http://c1.hpwren.ucsd.edu/archive/bm-axis/large/20180128/MP4/Q4.mp4