• Jan 04, 2018

The National Oceanic and Atmospheric Administration (NOAA) has issued an alert for a “Potential significant storm for Southwest California Tuesday and Wednesday” (January 9th-10th). If your grove was damaged by the Thomas Fire or is downhill from a burned area you are encouraged to plan for the possibility of unusual debris laden runoff flows.

Following is the NOAA alert.

This email is intended for critical weather partners in Los Angeles, Ventura, Santa Barbara, and San Luis Obispo Counties.

...Potential significant storm for Southwest California Tuesday and Wednesday...


  • First significant winter storm of season possible
  • Widespread moderate to heavy rain possible across Southwest California
  • Early estimates are 1-3” of rain, highest across south facing mountains and foothills
  • Strong and possibly damaging south winds, mainly in the mountains
  • Resort Level snow


  • Flash flooding and debris flows possible in recent burn areas due to potential for heavier rainfall intensities
  • Urban roadway flooding, with traffic delays and possible road closures
  • Downed tree limbs and power lines, especially in mountains
  • Winter driving conditions possible across higher mountain elevations


  • Moderate confidence in rainfall amounts and timing.
  • Moderate confidence in gusty winds and resort level snow.


A slow moving upper level low pressure system could bring the first significant winter storm of the season to Southwest California next week, with best estimate of timing between Tuesday and Wednesday night. While it is still very early, long range computer models are coming into better agreement on this storm system, showing the potential for widespread moderate to heavy rainfall across Southwest California. Preliminary rainfall estimates with this storm system are 1 to 3 inches, with the highest amounts focused on south facing mountains and foothills due to the strong southerly wind flow providing enhanced orographic rainfall. With the threat of heavier rainfall, the most significant potential impact will be flash flooding and debris flows in recent burn areas, including the Thomas burn area. It is still early, and the track of this storm and associated heavier rainfall could shift. Initially, snow levels will likely be rather high due to the southerly flow, but colder air is expected to filter in during the later portion of the storm, resulting in the possibility of snow accumulating at resort levels. People planning travel during this period should be prepared for the potential for traffic delays and possible road closures, especially in the recent burn areas.

Share This Post: