* WHAT. Dangerously hot conditions with temperatures up to 100 to 105 possible, and upwards of 105 to 115 possible over interior valleys and foothills including the Antelope Valley. * WHERE. A portion of southwest California. * WHEN. From Tuesday morning through Saturday, July 06. * IMPACTS. Heat related illnesses increase significantly during extreme heat events. Warm overnight low temperatures, especially late next week, will worsen the effects of extreme heat. * ADDITIONAL DETAILS. Very warm to hot conditions will have the potential to bring significant heat impacts to the coast, starting on Wednesday and continuing through the remainder of next week. Heat headlines may need to be expanded to include a larger portion of Southern California in later forecasts.

* WHAT. Dangerously hot conditions with temperatures up to 111 possible. * WHERE. A portion of southwest California. * WHEN. From Tuesday morning through late Friday night. * IMPACTS. Heat related illnesses increase significantly during extreme heat events.

* WHAT. Dangerously hot conditions with temperatures up to 111 possible. * WHERE. A portion of southwest California. * WHEN. From Tuesday morning through late Friday night. * IMPACTS. Heat related illnesses increase significantly during extreme heat events.

* WHAT. Dangerously hot conditions with temperatures up to 100 to 105 possible, and upwards of 105 to 115 possible over interior valleys and foothills including the Antelope Valley. * WHERE. A portion of southwest California. * WHEN. From Tuesday morning through late Friday night. * IMPACTS. Heat related illnesses increase significantly during extreme heat events. Warm overnight low temperatures, especially late in the week, will worsen the effects of extreme heat. * ADDITIONAL DETAILS. Very warm to hot conditions will have the potential to bring significant heat impacts to the coast, starting on Wednesday and continuing through the remainder of the week. Heat headlines may need to be expanded to include a larger portion of Southern California in later forecasts.

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.