AccuWeather

* WHAT...High temperatures in the upper 80s and low 90s near the coast to the 90s and near 100 degrees a few miles inland. Temperatures 83 to 95 degrees. Warmest conditions expected away from the immediate coast. * WHERE...Orange County Coastal Areas. * WHEN...Until 8 PM PDT Monday. * IMPACTS...Hot temperatures may cause heat illnesses. * ADDITIONAL DETAILS...Slight cooling will occur Monday, but temperatures will remain 10-15 degrees above normal. Much cooler Tuesday onward.More

* WHAT...Dangerously hot conditions with temperatures up to 100 to 110, except 110 to 114 for the western San Fernando Valley and the Santa Clarita Valley. Warm overnight low temperatures in the 70s, and locally higher, will lead to little recovery from the heat. * WHERE...A portion of southwest California. * WHEN...Until 8 PM PDT Monday. * IMPACTS...There is a high risk for dangerous heat illness for anyone, especially for the very young, the very old, those without air conditioning, and those active outdoors.More

* WHAT...Temperatures up to 97. * WHERE...Santa Barbara County Southeastern Coast and Ventura County Inland Coast. * WHEN...Until 8 PM PDT Monday. * IMPACTS...There is a high risk for heat illness for sensitive populations including the very young, the very old, those without air conditioning, and those active outdoors.More

...RED FLAG WARNING IN EFFECT THROUGH 10 PM THIS EVENING FOR SAN LUIS OBISPO COUNTY MOUNTAINS (INCLUDING THE SANTA LUCIA RANGE), SANTA MONICA MOUNTAINS, AND EASTERN SANTA YNEZ RANGE AND ADJACENT SOUTHEAST COAST OF SANTA BARBARA COUNTY DUE TO EXTREMELY HOT AND DRY CONDITIONS, LOCALLY GUSTY WINDS... ...RED FLAG WARNING IN EFFECT UNTIL 10 PM THIS EVENING FOR THE INTERIOR MOUNTAINS OF LOS ANGELES, VENTURA, AND SANTA BARBARA COUNTIES (INCLUDING THE SANTA SUSANA MOUNTAINS), ANTELOPE VALLEY, AND WESTERN SANTA YNEZ RANGE AND ADJACENT SOUTHWEST COAST OF SANTA BARBARA COUNTY DUE TO HOT AND DRY CONDITIONS, LOCALLY GUSTY WINDS, AND POTENTIAL DRY LIGHTNING... .A long duration heat wave will continue away from the immediate coast, with only minor and slow improvement through Monday. Near record high temperatures will continue this weekend with highs between 105 and 115 common over the valleys, lower mountains, and deserts, and 95 to 105 over the inland coastal plain. Very warm temperatures will persist at night across the mountains and foothills. Locally gusty winds will form as well, strongest over southern Santa Barbara County with Sundowner gusts between 25 and 40 mph each night through Monday. There will be increasing instability today and Sunday, leading to deep mixing heights up to 18,000 feet, which will also lead to a high risk for erratic plume-dominated fire behavior, especially in the mountains, foothills, and deserts. While standard Red Flag Warning criteria is unlikely, there is a history of large fires during similar weather conditions. There is a threat of thunderstorms this weekend as mid level monsoonal moisture and instability move into the region. The best chance of storms will be across the mountains of Los Angeles and Ventura counties, as well as the Antelope Valley through Sunday. Any storms that develop today and Sunday will have the potential for dry lightning strikes and strong/erratic downburst winds, with localized gusts to 50 mph possible. Due to the significant threat of large plume dominated fires and the risk of dry lightning and additional sundowner winds, the Red Flag Warning has been extended into Sunday evening for portions of the warning area. * WINDS...West winds 15 to 20 mph with gusts up to 30 mph, except locally stronger and erratic winds near any new fires or thunderstorms. * RELATIVE HUMIDITY...Minimums 8 to 12 percent. Poor overnight recoveries of 15 to 30 percent. * TEMPERATURES...Maximums between 105 and 108 are expected. * THUNDERSTORMS...There is an increasing risk for dry lightning over the Antelope Valley through this evening, especially eastern portions, which can start new fires, spread them rapidly with gusty downburst winds, and provide little if any extinguishing rain. Any thunderstorms that develop over the Antelope Valley or nearby areas, will have the potential to produce strong and erratic outflow wind gusts to 50 mph. * IMPACTS...If fire ignition occurs, conditions are favorable for rapid fire spread and extreme fire behavior which would threaten life and property.More

...RED FLAG WARNING IN EFFECT THROUGH 10 PM THIS EVENING FOR SAN LUIS OBISPO COUNTY MOUNTAINS (INCLUDING THE SANTA LUCIA RANGE), SANTA MONICA MOUNTAINS, AND EASTERN SANTA YNEZ RANGE AND ADJACENT SOUTHEAST COAST OF SANTA BARBARA COUNTY DUE TO EXTREMELY HOT AND DRY CONDITIONS, LOCALLY GUSTY WINDS... ...RED FLAG WARNING IN EFFECT UNTIL 10 PM THIS EVENING FOR THE INTERIOR MOUNTAINS OF LOS ANGELES, VENTURA, AND SANTA BARBARA COUNTIES (INCLUDING THE SANTA SUSANA MOUNTAINS), ANTELOPE VALLEY, AND WESTERN SANTA YNEZ RANGE AND ADJACENT SOUTHWEST COAST OF SANTA BARBARA COUNTY DUE TO HOT AND DRY CONDITIONS, LOCALLY GUSTY WINDS, AND POTENTIAL DRY LIGHTNING... .A long duration heat wave will continue away from the immediate coast, with only minor and slow improvement through Monday. Near record high temperatures will continue this weekend with highs between 105 and 115 common over the valleys, lower mountains, and deserts, and 95 to 105 over the inland coastal plain. Very warm temperatures will persist at night across the mountains and foothills. Locally gusty winds will form as well, strongest over southern Santa Barbara County with Sundowner gusts between 25 and 40 mph each night through Monday. There will be increasing instability today and Sunday, leading to deep mixing heights up to 18,000 feet, which will also lead to a high risk for erratic plume-dominated fire behavior, especially in the mountains, foothills, and deserts. While standard Red Flag Warning criteria is unlikely, there is a history of large fires during similar weather conditions. There is a threat of thunderstorms this weekend as mid level monsoonal moisture and instability move into the region. The best chance of storms will be across the mountains of Los Angeles and Ventura counties, as well as the Antelope Valley through Sunday. Any storms that develop today and Sunday will have the potential for dry lightning strikes and strong/erratic downburst winds, with localized gusts to 50 mph possible. Due to the significant threat of large plume dominated fires and the risk of dry lightning and additional sundowner winds, the Red Flag Warning has been extended into Sunday evening for portions of the warning area. * WINDS...West to north winds 10 to 15 mph with gusts up to 30 mph. Gusty and erratic winds possible with any new fires or thunderstorms. * RELATIVE HUMIDITY...Minimums 8 to 18 percent. Poor overnight recoveries of 15 to 30 percent. * TEMPERATURES...Maximums between 100 and 110 common for lower elevations, with minimums between 80 and 90. * THUNDERSTORMS...There is an increasing risk for dry lightning over Los Angeles and Ventura Counties this weekend, which can start new fires, spread them rapidly with gusty downburst winds, and provide little if any extinguishing rain. * IMPACTS...If fire ignition occurs, conditions are favorable for rapid fire spread and extreme fire behavior which would threaten life and property.More

The South Coast AQMD has extended an air quality alert in the South Coast Air Basin due to high levels of ozone (smog) due to the ongoing heat wave and updated an air quality alert due to increased fine particle pollution from wildfire smoke in the region. The air quality alert is in effect until Monday evening for smog and Sunday evening for wildfire smoke. Elevated levels of ozone the predominant summertime pollutant are likely to result in poor air quality in the afternoon and early- evening hours. Ozone air pollution can cause respiratory health problems, including trouble breathing, asthma attacks, and lung damage. Children, older adults, and people with asthma or COPD may be more sensitive to the health effects of ozone. Air quality can change depending on time of day and weather conditions. Increased emissions of chemicals and faster ozone formation rates due to heat, along with low winds and stagnant weather can cause unusually high and persistent levels of ozone pollution. To help minimize ozone air pollution levels: Limit the use of gasoline powered lawn and garden equipment until evening hours Conserve electricity and set your air conditioner at a higher temperature Try to delay trips to the gas station and the use of household chemicals until the evening If you smell smoke or see ash due to a wildfire, remain indoors with windows and doors closed or seek alternative shelter, if feasible. Avoid vigorous physical activity and run your air conditioner and/or an air purifier. If possible, do not use whole house fans or swamp coolers that bring in outside air. Avoid burning wood in your fireplace or firepit and minimize sources of indoor air pollution such as candles, incense, pan-frying, and grilling. If you must be outdoors, keep the time brief and wear a tightly-fitted N-95 or P- 100 respirator to help reduce exposure. Limit the use of gasoline powered lawn and garden equipment. Exposure to particle pollution can cause serious health problems, aggravate lung disease, cause asthma attacks and acute bronchitis, and increase risk of respiratory infections. People with heart or lung diseases should follow their doctor's advice for dealing with episodes of unhealthy air quality. Additionally, people with respiratory or heart disease, older adults, and children are particularly susceptible and should avoid prolonged exposure, strenuous activities or heavy exertion as conditions dictate. Levels of particle pollution can vary hour by hour and by location depending on fire behavior and local weather conditions. Check air quality levels and take appropriate action as needed. When air quality index (AQI) levels are Unhealthy for Sensitive Groups (orange), people with heart or lung disease, pregnant women, children, and older adults should limit prolonged or heavy outdoor exertion. When air quality reaches Unhealthy (red) AQI levels, everyone may experience adverse health effects and sensitive groups should avoid prolonged time outdoors. At Very Unhealthy (purple) AQI levels, sensitive groups should avoid all outdoor physical activity and everyone else should avoid prolonged or heavy outdoor exertion. To view current and forecasted air quality levels, visit the South Coast Air Quality Management District website at aqmd.gov or download the mobile app at www.aqmd.gov/mobileapp. Additional details for this air quality alert may be available at www.aqmd.gov/advisory.More

The South Coast Air Quality Management District has issued an Air Quality Alert due to elevated fine particulate matter levels due to wildfire smoke and high ozone levels. This Air Quality Alert is IN EFFECT UNTIL 8 PM PDT MONDAY The South Coast AQMD has extended an air quality alert in the South Coast Air Basin due to high levels of ozone (smog) due to the ongoing heat wave and updated an air quality alert due to increased fine particle pollution from wildfire smoke in the region. The air quality alert is in effect until Monday evening for smog and Sunday evening for wildfire smoke. Elevated levels of ozone the predominant summertime pollutant are likely to result in poor air quality in the afternoon and early- evening hours. Ozone air pollution can cause respiratory health problems, including trouble breathing, asthma attacks, and lung damage. Children, older adults, and people with asthma or COPD may be more sensitive to the health effects of ozone. Air quality can change depending on time of day and weather conditions. Increased emissions of chemicals and faster ozone formation rates due to heat, along with low winds and stagnant weather can cause unusually high and persistent levels of ozone pollution. To help minimize ozone air pollution levels: Limit the use of gasoline powered lawn and garden equipment until evening hours Conserve electricity and set your air conditioner at a higher temperature Try to delay trips to the gas station and the use of household chemicals until the evening If you smell smoke or see ash due to a wildfire, remain indoors with windows and doors closed or seek alternative shelter, if feasible. Avoid vigorous physical activity and run your air conditioner and/or an air purifier. If possible, do not use whole house fans or swamp coolers that bring in outside air. Avoid burning wood in your fireplace or firepit and minimize sources of indoor air pollution such as candles, incense, pan-frying, and grilling. If you must be outdoors, keep the time brief and wear a tightly-fitted N-95 or P- 100 respirator to help reduce exposure. Limit the use of gasoline powered lawn and garden equipment. Exposure to particle pollution can cause serious health problems, aggravate lung disease, cause asthma attacks and acute bronchitis, and increase risk of respiratory infections. People with heart or lung diseases should follow their doctor's advice for dealing with episodes of unhealthy air quality. Additionally, people with respiratory or heart disease, older adults, and children are particularly susceptible and should avoid prolonged exposure, strenuous activities or heavy exertion as conditions dictate. Levels of particle pollution can vary hour by hour and by location depending on fire behavior and local weather conditions. Check air quality levels and take appropriate action as needed. When air quality index (AQI) levels are Unhealthy for Sensitive Groups (orange), people with heart or lung disease, pregnant women, children, and older adults should limit prolonged or heavy outdoor exertion. When air quality reaches Unhealthy (red) AQI levels, everyone may experience adverse health effects and sensitive groups should avoid prolonged time outdoors. At Very Unhealthy (purple) AQI levels, sensitive groups should avoid all outdoor physical activity and everyone else should avoid prolonged or heavy outdoor exertion. To view current and forecasted air quality levels, visit the South Coast Air Quality Management District website at aqmd.gov or download the mobile app at www.aqmd.gov/mobileapp. Additional details for this air quality alert may be available at www.aqmd.gov/advisory.More