A shallow marine layer depth across the coastal waters will bring areas of dense fog this morning. Mariners should be prepared for abrupt visibility changes down to one nautical mile or less. Reduce speeds and be on the lookout for exposed rocks and other vessels, including large ships in the shipping lanes. Use radar or GPS navigation if available, and consider remaining in harbor if such equipment is unavailable. In addition, remnant upper-level moisture from post-tropical cyclone Alberto could produce isolated showers and thunderstorms through today. Any showers or thunderstorms could be capable of producing dangerous cloud-to-ocean lightning, gusty and erratic winds up to 35 to 40 knots, small hail, and brief heavy rainfall. This is a low confidence situation, and those with interests over the coastal waters are encouraged to closely monitor the latest conditions.

A shallow marine layer depth acrossthe coastal waters will bring areas of dense fog through Monday morning. Mariners should be prepared for abrupt visibility changes down to one nautical mile or less. Reduce speeds and be on the lookout for exposed rocks and other vessels, including large ships in the shipping lanes. Use radar or GPS navigation if available, and consider remaining in harbor if such equipment is unavailable. In addition, remnant upper-level moisture from post-tropical cyclone Alberto could produce isolated showers and thunderstorms through Monday evening. Any showers or thunderstorms could be capable of producing dangerous cloud-to-ocean lightning, gusty and erratic winds up to 35 to 40 knots, small hail, and brief heavy rainfall. This is a highly uncertain situation, and those with interests over the coastal waters are encouraged to closely monitor the latest situation. Please consider making alternative plans if the chances for thunderstorms were to increase.

* WHAT. Temperatures 92 to 101 degrees common. Continued warm overnight lows will add to the heat stress for these areas. * WHERE. Cuyama Valley, San Luis Obispo County Interior Valleys, San Luis Obispo County Mountains, Santa Clarita Valley, Santa Ynez Valley, and Western San Fernando Valley. * WHEN. Until 8 PM PDT Monday. * IMPACTS. Hot temperatures may cause heat illnesses.

The South Coast Air Quality Management District has issued an Air Quality Alert due to elevated ozone air pollution. This Air Quality Alert is in effect until 7 PM PDT Tuesday. Elevated levels 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 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 the 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 Check air quality levels and take appropriate action as needed. When air quality index (AQI) are Unhealthy for Sensitive Groups (orange), people with heart or lung disease, pregnant women, children, and older adult 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 time outdoors. As Very Unhealthy (purple) AQI levels, sensitive groups should avoid all outdoors 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. For the additional information, call the South Coast Air Quality Management District.