Piedmont, CA Warnings, Watches and Advisories

Do not drive vehicles through flooded areas. The water depth or fast flowing water/mud/debris from a flash flood will make road conditions unsafe. Do not rely soley on data presented here or other third-party websites - always check your official national and local weather service agency website, socials, radio and/or TV stations for making critical decisions related to weather events.

Please carefully read each posted Warning and Alert as it relates to the area(s) being affected. We may provide a wider range of issued severe weather warnings for surrounding cities and counties, so some alerts may not directly impact this location. This is done to help with preparing for severe weather that may overlap or be heading towards Piedmont.

Use the Radar Maps link provided to understand the trajectory of a storm.

Frost Advisory issued November 8 at 2:58AM PST until November 8 at 9:00AM PST by NWS San Diego CA

* WHAT...Temperatures as low as 30 will result in frost formation. * WHERE...Apple and Lucerne Valleys. * WHEN...Until 9 AM PST this morning. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered.

Red Flag Warning issued November 8 at 2:08AM PST until November 8 at 11:00AM PST by NWS San Diego CA

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 11 AM PST THIS MORNING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR THE INLAND EMPIRE AND THE COASTAL SLOPES OF THE SAN BERNARDINO COUNTY MOUNTAINS... ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 11 AM PST THIS MORNING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR THE MOUNTAINS IN SAN DIEGO AND RIVERSIDE COUNTIES... * WINDS...Northeast 5 mph or less. * RELATIVE HUMIDITY...As low as 10 percent. * IMPACTS...Any fires that develop will likely spread rapidly. Outdoor burning is not recommended. * LOCATION...San Bernardino and Riverside County Valleys -The Inland Empire and San Bernardino County Mountains-Including The Mountain Top And Front Country Ranger Districts Of The San Bernardino National Forest.

Red Flag Warning issued November 8 at 2:08AM PST until November 8 at 11:00AM PST by NWS San Diego CA

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 11 AM PST THIS MORNING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR THE INLAND EMPIRE AND THE COASTAL SLOPES OF THE SAN BERNARDINO COUNTY MOUNTAINS... ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 11 AM PST THIS MORNING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR THE MOUNTAINS IN SAN DIEGO AND RIVERSIDE COUNTIES... * WINDS...East 10 to 15 mph with gusts up to 30 mph. * RELATIVE HUMIDITY...As low as 10 percent. * IMPACTS...Any fires that develop will likely spread rapidly. Outdoor burning is not recommended. * LOCATION...San Diego County Mountains-Including The Palomar And Descanso Ranger Districts of the Cleveland National Forest.

Red Flag Warning issued November 8 at 2:08AM PST until November 8 at 11:00AM PST by NWS San Diego CA

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 11 AM PST THIS MORNING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR THE INLAND EMPIRE AND THE COASTAL SLOPES OF THE SAN BERNARDINO COUNTY MOUNTAINS... ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 11 AM PST THIS MORNING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR THE MOUNTAINS IN SAN DIEGO AND RIVERSIDE COUNTIES... * WINDS...Northeast 5 to 10 mph. * RELATIVE HUMIDITY...As low as 10 percent. * IMPACTS...Any fires that develop will likely spread rapidly. Outdoor burning is not recommended. * LOCATION...Riverside County Mountains-Including The San Jacinto Ranger District Of The San Bernardino National Forest.

Frost Advisory issued November 7 at 11:37PM PST until November 8 at 8:00AM PST by NWS Eureka CA

* WHAT...Temperatures as low as 34 will result in frost formation. * WHERE...Humboldt Interior, Southern Mendocino Interior, Southwestern Humboldt, and Southern Lake. * WHEN...Until 8 AM PST Friday. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered.

Freeze Warning issued November 7 at 11:15PM PST until November 8 at 9:00AM PST by NWS Los Angeles/Oxnard CA

* WHAT...Sub-freezing temperatures as low as 26 expected. * WHERE...Antelope Valley, Cuyama Valley, San Luis Obispo County Interior Valleys, and Southern Salinas Valley. * WHEN...Until 9 AM PST Friday. * IMPACTS...Frost and freeze conditions could kill crops, other sensitive vegetation and possibly damage unprotected outdoor plumbing.

Air Quality Alert issued November 7 at 9:33PM PST by NWS Los Angeles/Oxnard CA

The Ventura County Air Pollution Control District is issuing an Air Quality Alert because of expected unhealthy conditions due to smoke from the Mountain Fire. Measured PM2.5 values are anticipated to reach Unhealthy Levels in various locations throughout Ventura County with the potential to stay Unhealthy through Saturday afternoon. Conditions can change rapidly due to fire activity and local weather conditions. The air quality alert is in effect until 4PM PST Saturday with the possiblity of extension if conditions warrant. Smoke and ash from wildfires contain very small particles - particulate matter with a diameter of 2.5 micrometers or less - that can harm the lungs and heart. When air quality reaches an unhealthy level or when you see or smell smoke, the district recommends that everyone: Avoid strenuous outdoor activity. If you must work outside, wear a properly fitted N-95 mask. Operate home and car air conditioners in recycle or recirculation mode. Close the fresh air intake. Stay indoors as much as possible, preferably in a clean room with an indoor air filtration device where you can avoid cooking or burning candles. Close all windows and doors that lead outside. Drink plenty of fluids. A lower range of AQI can affect sensitive groups. This includes children, older adults and people with diabetes or heart or lung conditions. An AQI forecast for PM2.5 reflects what is possible for a 24-hour day on average. At times, air quality is likely to be better or worse than what is indicated for the entire period. Levels of smoke and particles and the areas affected will vary over time. For real-time data on air quality, check the AirNow NowCast AQI at airnow.gov or fire.airnow.gov. AirNow uses hourly data from the district's five monitoring stations throughout the county to provide air quality information for the surrounding regions. Get Daily Air Quality Reports from the district by signing up to receive emails at vcapcd.org or by following the district on X, Facebook, and NextDoor.

Air Quality Alert issued November 7 at 9:33PM PST by NWS Los Angeles/Oxnard CA

...AIR QUALITY ALERT FOR HARMFUL FINE PARTICLE POLLUTION LEVELS DUE TO WILDFIRE SMOKE AND MANDATORY WOOD-BURNING BAN IN EFFECT... * WHAT...The South Coast AQMD has issued an air quality alert due to increased fine particle pollution from wildfire smoke and a mandatory wood-burning ban for residents in the South Coast Air Basin. The No-Burn rule bans burning wood, pellets, and manufactured fire logs in any indoor or outdoor wood-burning device. * WHERE...Smoke impacts are expected in the San Gabriel Mountains, Santa Clarity Valley, San Fernando Valley, Santa Monica Mountains and Malibu Coast. Levels of particle pollution can vary by time and location depending on fire activity and local weather conditions. The wood-burning ban is in effect in the South Coast Air Basin, which includes non-desert portions of Los Angeles county. No-Burn Day alerts do not apply to areas above 3,000 feet in elevation. Homes that rely on wood as a sole source of heat, low-income households and those without natural gas service also are exempt from the requirement. * WHEN...Smoke advisory is in effect from 11 AM Friday to 3 PM Saturday and wood-burning ban is in effect on Friday. * IMPACTS...Particles in wildfire smoke can get deep into the lungs and cause serious health problems such as heart attacks, strokes, asthma attacks, and difficulty breathing. Everyone can be affected, but people with lung or heart disease, older adults, people who are pregnant, children, and those who spend a lot of time outdoors are at greater risk. No-Burn Days are based on fine particle pollution levels that are forecasted for an entire 24-hour period, which may not be reflected in real-time air quality maps.

Red Flag Warning issued November 7 at 5:59PM PST until November 8 at 11:00AM PST by NWS Los Angeles/Oxnard CA

...RED FLAG WARNING IN EFFECT UNTIL 11 AM FRIDAY FOR ALL THE LOS ANGELES AND VENTURA COUNTY MOUNTAINS DUE TO STRONG SANTA ANA WINDS AND LOW HUMIDITIES... .Offshore flow continues to weaken through the evening as the region begins to return to more typical diurnal wind patterns. Still some lingering gusty northeast winds across parts of LA/Ventura Counties, some of which will continue into the overnight hours and through the Saturday morning, though generally much lighter with peak gusts between 20 and 30 mph. Strongest winds will be over the higher ridgetops. Across the Ventura coastal plain and coastal valleys, a light west wind 6-12 mph is possible this afternoon through early evening before shifting back to northeast overnight into Friday morning. Humidity recoveries will remain quite poor tonight, with slowing increasing recoveries through the the weekend. Daytime humidities will rise slightly but remain mostly below 30 percent into the weekend away from the immediate coast. Over the weekend typical diurnal winds are expected and mostly under 15 mph. Humidities will slowly be climbing as well. * WINDS...Northeast winds 15 to 25 mph with gusts to 40 mph through this evening, lowering overnight. * RELATIVE HUMIDITY...Humidity levels between 8 and 15 percent. * IMPACTS...If fire ignition occurs, conditions are favorable for rapid fire spread and extreme fire behavior which would threaten life and property. With the threat of even stronger Santa Ana winds and drier fuels with the Wednesday/Thursday Santa Ana event, there will be an increased risk for long range spotting.

Red Flag Warning issued November 7 at 5:59PM PST until November 8 at 11:00AM PST by NWS Los Angeles/Oxnard CA

...RED FLAG WARNING IN EFFECT UNTIL 11 AM FRIDAY FOR ALL THE LOS ANGELES AND VENTURA COUNTY MOUNTAINS DUE TO STRONG SANTA ANA WINDS AND LOW HUMIDITIES... .Offshore flow continues to weaken through the evening as the region begins to return to more typical diurnal wind patterns. Still some lingering gusty northeast winds across parts of LA/Ventura Counties, some of which will continue into the overnight hours and through the Saturday morning, though generally much lighter with peak gusts between 20 and 30 mph. Strongest winds will be over the higher ridgetops. Across the Ventura coastal plain and coastal valleys, a light west wind 6-12 mph is possible this afternoon through early evening before shifting back to northeast overnight into Friday morning. Humidity recoveries will remain quite poor tonight, with slowing increasing recoveries through the the weekend. Daytime humidities will rise slightly but remain mostly below 30 percent into the weekend away from the immediate coast. Over the weekend typical diurnal winds are expected and mostly under 15 mph. Humidities will slowly be climbing as well. * WINDS...Northeast winds 15 to 25 mph with gusts to 40 mph through this evening, becoming weaker overnight. * RELATIVE HUMIDITY...Humidity levels between 8 and 12 percent. * IMPACTS...If fire ignition occurs, conditions are favorable for rapid fire spread and extreme fire behavior which would threaten life and property. With the threat of even stronger Santa Ana winds and drier fuels with the Wednesday/Thursday Santa Ana event, there will be an increased risk for long range spotting.

Air Quality Alert issued November 7 at 4:56PM PST by NWS Los Angeles/Oxnard CA

* WHAT...The South Coast AQMD has issued an air quality alert due to increased fine particle pollution from wildfire smoke and a mandatory wood-burning ban for residents in the South Coast Air Basin. The No-Burn rule bans burning wood, pellets, and manufactured fire logs in any indoor or outdoor wood-burning device. * WHERE...Smoke impacts are expected in the San Gabriel Mountains, Santa Clarity Valley, San Fernando Valley, Santa Monica Mountains and Malibu Coast. Levels of particle pollution can vary by time and location depending on fire activity and local weather conditions. The wood-burning ban is in effect in the South Coast Air Basin, which includes non-desert portions of Los Angeles county. No-Burn Day alerts do not apply to areas above 3,000 feet in elevation. Homes that rely on wood as a sole source of heat, low-income households and those without natural gas service also are exempt from the requirement. * WHEN...Smoke advisory is in effect from 11 AM Friday to 3 PM Saturday and wood-burning ban is in effect on Friday. * IMPACTS...Particles in wildfire smoke can get deep into the lungs and cause serious health problems such as heart attacks, strokes, asthma attacks, and difficulty breathing. Everyone can be affected, but people with lung or heart disease, older adults, people who are pregnant, children, and those who spend a lot of time outdoors are at greater risk. No-Burn Days are based on fine particle pollution levels that are forecasted for an entire 24-hour period, which may not be reflected in real-time air quality maps.

Air Quality Alert issued November 7 at 11:54AM PST by NWS San Diego CA

* WHAT...The South Coast AQMD has issued a mandatory wood-burning ban for residents in the South Coast Air Basin. The No-Burn rule bans burning wood, pellets, and manufactured fire logs in any indoor or outdoor wood-burning device. * WHERE...The South Coast Air Basin, which includes Orange County and non-desert portions of Los Angeles, Riverside, and San Bernardino counties. No-Burn Day alerts do not apply to areas above 3,000 feet in elevation, the Coachella Valley, or the High Desert. Homes that rely on wood as a sole source of heat, low-income households and those without natural gas service also are exempt from the requirement. * WHEN...Friday. * IMPACTS...Particles in smoke can get deep into the lungs and cause health problems (including asthma attacks), increases in emergency room visits, and hospitalizations. No-Burn Days are needed to protect public health when fine particle pollution levels are expected to be high anywhere in the South Coast Air Basin. No-Burn Days are based on fine particle pollution levels that are forecasted for an entire 24-hour period, which may not be reflected in real- time air quality maps.