Thread by @KatieKPIX

This is the command center at @CALFIRECZU HQ. Teams with @SantaCruzSO1 @NWSBayArea Monterey, & fire/ambulance are here coordinating the response to the potential mudslides & debris flows in the burn scar areas.
5,000+ people under mandatory evacuation orders. @KPIXtv

These are the scientists with @NWSBayArea & @sccounty closely monitoring weather conditions & will give the “all clear” to let emergency crews back into evacuated areas after the threat of mudslides/debris flows has passed. They’ll be in the command center all night. @KPIXtv

1/ According to @CALFIRECZU this is the plan for the #SantaCruz mountains tonight:
Scientists from @NWSBayArea & @sccounty will monitor weather & rain conditions all night from the command center. The biggest threat to trigger mudslides and debris flows is high intensity rain.

2/ The threshold for mudslides/debris flows is 0.3” of rain in 15 mins, 0.5” in 30 mins or 0.7” in 45 mins. Rain at that level or greater can trigger slides or flows. The heaviest/highest intensity rain is expected to fall in the #SantaCruz burn scar areas from 11pm-3am.

3/ The “all clear” from the scientists means they believe rains at or above that threshold level are done with this weather system. At that point, @sccounty geologists will go into the high risk areas (below the burn scars) to check soil conditions & look for signs of slides.

4/ Once the geologists say the ground is stable, @CALFIRECZU @SantaCruzSO1 & @PGE4Me crews can go into those areas to make sure it’s safe for evacuated residents to be allowed back in. This process could take a day or more depending on storm damage.

5/ The wild card factor here are the winds. Lots of trees are already stressed from the fires. Now the ground is wet. Add in high winds & there is the potential for a lot of those trees to come down, possibly on roads & power lines.

6/ Meteorologists at the command center think the geologists will be able to get into high risk areas tomorrow morning to start their assessments. The big unknown is how long from that point until residents are allowed in & all of that really just depends on what happens tonight.

7/ Important to add: Until rainfall levels are below the threshold mentioned above, emergency crews WILL NOT re-enter high risk areas to respond to 911 calls. CalFire says anyone who chooses not to evacuate needs to be prepared to be on their own until the threat of slides passes