California Resiliency Alliance Wildfire Outlook Reports

  • Environment
  • by BPC Staff
  • September 6, 2018
  • 0 Comments

Wildfire Outlook Reports

Attached are three monthly wildfire outlook reports produced by the National Interagency Fire Center’s Predictive Services.
  • National Significant Wildland Fire Potential Outlook (Sept-Dec)
  • Northern California Operations Monthly & Seasonal Outlook (Sept-Dec)
  • Southern & Central California Operations Monthly & Seasonal Outlook (Sept-Dec)
National Significant Wildland Fire Potential Outlook (Outlook Period: September, October, November and December 2018)
Northern California (pg 4-5)
  • September – December: Above Normal significant large fire potential is expected for the entire outlook area in September followed by a return to Normal potential for October through December.
  • Live Fuel Moisture: Live fuel moisture values have also reached critically low values, weeks ahead of normal. As a result, fire behavior has been extreme and spread rates have been rapid at elevations below 6000’ this summer, even during non-wind events.
  • Weather: September is expected to be dry with near normal temperatures state-wide. Although lightning becomes less frequent in September, moderate to strong dry offshore wind events become more common.
Southern California (pg 5)
  • September – October: Above Normal significant wildland fire potential is expected along the coast and foothills across Southern California and the hills and mountains surrounding the central valley including the Sierra. Areas not mentioned can expect Normal significant large fire potential through the outlook period.
  • November – December: These areas will retain the elevated potential except for the central Sierra which will return to Normal potential. Areas not mentioned can expect Normal significant large fire potential through the outlook period. In November, large fire potential is expected to trend back to near normal levels from north to south. By early December, most areas will have received enough rainfall to preclude large fire activity.
  • Live Fuel Moisture: Live fuel moisture reached critically dry conditions over most elevations below 6,000 feet during the second week of the month. Therefore, live fuel moisture is close to values usually seen in late September or early October.
  • Weather Patterns: 
    • Long range models indicate a persistent trough may develop over the Pacific Northwest. This would likely keep the district under Southwesterly flow aloft with onshore flow at the surface. The monsoon may remained bottled up over Arizona and the Southwest. Therefore, additional wet thunderstorms are unlikely the rest of the summer. Temperatures will likely remain a few degrees above normal, but the prolonged heat waves of July and August are not expected.
    • Local studies indicate there may be a near normal, or slightly below normal, number of offshore wind days through November which matches the pattern seen in the long range models. However, 2-3 offshore wind events will likely occur prior to the onset of significant wetting rains in October or early November.
Northern California Operations Monthly & Seasonal Outlook (Sept-Dec)
  • Near normal temperatures with below normal precipitation
  • Dry N-NE / Offshore wind events will increase in frequency and intensity from September through the middle of October
  • Fuels of all size classes drier than normal and close to record values
  • Abundant load of fine fuels and brush at mid and lower elevations
  • Exceptional fire behavior, spread rates, and acreage likely to continue
  • Above Normal Large Fire Potential all areas in September
  • Areas east of the Cascade-Sierra crest back to Normal in October. Otherwise, continued Above Normal
  • All areas Normal in November-December
  • ENSO neutral currently…increasing chances of El Niño in the fall
Southern & Central California Operations Monthly & Seasonal Outlook (Sept-Dec)
  • Above normal temperatures expected to continue into the fall.
  • Few, if any, additional monsoonal storms.
  • Above normal large fire potential most areas, slowly decreasing from north to south in the fall.
  • Near normal number of offshore wind events expected through November.
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