Storms, debris flow, and rock slides

I want rain, but 9″?

Just received this notice from the National Weather Service. Please pass this along to anyone you know living near a possible debris flow along Sycamore Canyon Road. Have a safe and Happy Thanksgiving.

Good morning,

This heads-up briefing is targeted at public safety and emergency response personnel in the Big Sur area of Monterey County – to heighten awareness of potential impacts from debris flow/slides in Sycamore Canyon near the Pfeiffer Burn Scar.

Please contact our office at 831-656-1717 any time – a forecaster available 24 hours a day for immediate support issues.


Strong Pacific storms will bring periods of rainfall to the area beginning by Saturday noontime and persisting through Tuesday and Wednesday. Rainfall will be moderate to heavy at times and will result in the most significant rainfall of the season to date.

Rain begins by noontime Saturday and continues through Tuesday/Wednesday. The time period of greatest concern for heavy rain will be Saturday afternoon-Sunday. A secondary period of heavy rain is possible Tuesday.

Wind will increase overnight Saturday and into Sunday.

Flooding/Slides: Threat will increase as rain accumulations increase with greatest risks during and immediately following the heaviest rainfall.

Rain: Rainfall totals from Saturday through Wednesday will range from 2 to 4 inches with up to 9 inches or more expected in the higher mountains.

Wind: Southwest winds of 25 to 35 MPH with gusts of 45 MPH at the coast and up to 60 MPH in the higher mountains. Potential for trees and downed power lines.

Flooding and Slides: Flooding of small streams as well as low lying, and poorly drained areas is expected. Debris flow potential from Pfeiffer Burn Scar area in Sycamore Canyon during and following periods of most intense rainfall is high.

Rockfalls can be expected in the area and along Highway 1 due to the ground becoming wet and the heavy rain. Thresholds that we will use for debris flow concern:

0.70 inches in 15 minutes
0.90 inches in 1 hour
1.50 inches in 3 hours
2.00 inches in 6 hours

Logan Johnson
Warning Coordination Meteorologist
National Weather Service
San Francisco Bay Area/Monterey, CA