With exceedingly dry vegetation and now dry lightning, drought stricken California is facing the challenge of increased in wildfire activity.
The graphic below highlights the current fires reported by California Department of Forestry and Fire Protection across central and northern California. The fires in grey are incidents that the state of California is responding to while the ones in Red are multi-agency responses. In addition, the fires that have a lightning bolt are wildfires that were ignited by a lightning.
One of the fires that has been of increased concern due to its quick spread and location is the Rocky Fire. This fire is located to the northwest of Sacramento and just east of the Clear Lake region.
The Rocky Fire quickly spread east and has left a large burn scare. In addition, active fires continue on the eastern edge of the fire perimeter. The Landsat 8 Satellite image below was produced with the Operational Land Imager and outline recently burned areas. For more information about this imagery see NASA’s post.
The latest information from California Department of Forestry and Fire Protection about the Rocky Fire was on Wed, 8/5/15. At that point 69,600 acres had been burned 43 residences and 53 outbuildings destroyed and 8 structures damaged. The positive news is fire crews were gaining control and 40% of the fire was contained now contained. The response has been multi agency and 3,635 fire personal remain on the ground. Even with the crews making progress on containment, 6,529 structures are still threatened. Full containment is not anticipated for another week. Widespread road closures and evacuations continue and several shelters for people and animals are operating in the area. The cause of the Rocky Fire is not is not known at this time.
In addition to the area within the fire parameter, smoke from the Rocky Fire as well as other fires in California and Southern Oregon are impacting Nevada and areas east.
Weather Conditions Impacting Fighting of Wildfires
A point of concern for those responding to the fires over the next few days is the weather forecast. A weak low pressure system will impact parts of Central and Northern California. Unfortunately this low will not bring rain, but instead the risk of dry thunderstorms into Friday. Hence additional fires may be triggered due to lightning. In addition, relative humidity levels will remain lower for areas inland which will help to sustain the fires. Below are the forecast minimum Relative humidities for Friday night with values in the 20% to 40% range.
Wind speeds and especially wind gusts may also continue to be a challenge for firefighters. While some locations will see lighter wind speeds, even winds in the 5 to 15 kt range (5 to 17 mph) will not be welcomed by fire fighters. Another complication of the weather is fires tend to modify the weather conditions in the near the fire. So conditions will likely be dryer, hotter and gustier in the vicinity of flare ups.
Wind Gusts midday Friday in Knots.
Because of the risk of dry thunderstorms as well as the other meteorological factors, the NWS offices in Central California have issued Fire Weather Watches and Red Flag Warnings in many locations in Central and Northern California through Friday.
A Fire Weather Watch is issued to indicate the potential for dangerous fire weather conditions 24 to 96 hours in advance of the expected onset of criteria. A Red Flag Warning is issued to warn of an impending or occurring Red Flag Event. Its issuance denotes a high degree of confidence that weather and fuel conditions consistent with local Red Flag Event criteria will occur in 12 to 24 hours or less.
For those in the Central and Northern California, we encourage you to remain in alert for new fires and changing conditions with ongoing fires. Have a way to be notified if evacuation orders are issued for your area as well as a plan of what items to quickly grab (including important documents) and finally a safe place to go. Also have a plan for staying connected to friends and family. Finally think through how you will gather and where you will take your pets and livestock in the event that evacuation orders are issued for your area.
The team at WxIntegrations will continue to provide relevant information and resources to help you better understand and prepare by incorporating weather impacts into your planning and response.