Simi Valley 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 Simi Valley.

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

Frost Advisory issued November 27 at 2:50AM PST until November 27 at 10:00AM PST by NWS Eureka CA

* WHAT...Temperatures as low as 36 will result in frost formation. * WHERE...Del Norte Coast. * WHEN...Until 10 AM PST this morning. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered.

Frost Advisory issued November 27 at 2:50AM PST until November 27 at 10:00AM PST by NWS Eureka CA

* WHAT...Temperatures as low as 34 will result in frost formation. * WHERE...Humboldt Coast, and Mendocino Coast. * WHEN...Until 10 AM PST this morning. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered.

Frost Advisory issued November 27 at 2:50AM PST until November 27 at 10:00AM PST by NWS Eureka CA

* WHAT...Temperatures as low as 32 will result in frost formation. * WHERE...Del Norte Interior and Northern Humboldt Interior. * WHEN...Until 10 AM PST this morning. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered.

Lake Wind Advisory issued November 27 at 2:28AM PST until November 28 at 4:00PM PST by NWS Las Vegas NV

* WHAT...North winds 15 to 25 mph with gusts up to 35 mph expected. * WHERE...Lake Mohave and Lake Havasu. * WHEN...From 4 AM PST / 5 AM MST to 4 PM PST / 5 PM MST Thursday. * IMPACTS...Strong winds and rough waves on area lakes will create hazardous conditions for small craft.

Beach Hazards Statement issued November 26 at 11:17PM PST until November 28 at 10:00PM PST by NWS San Francisco CA

* WHAT...A long period south swell will result in an energetic surf zone and increasing risk of sneaker waves and rip currents. * WHERE...San Francisco, Coastal North Bay Including Point Reyes National Seashore, San Francisco Peninsula Coast, Northern Monterey Bay and Southern Monterey Bay and Big Sur Coast Counties. * WHEN...Through Thursday evening. * IMPACTS...Dangerous swimming and surfing conditions. Large waves can sweep across the beach without warning, pulling people into the sea from rocks, jetties, and beaches. Sudden immersion in cold water can result in cold water shock even for the most experienced swimmers. Cold water shock can result in dramatic changes in breathing, heart rate and blood pressure, greatly increasing the risk of drowning in rough open waters.

Frost Advisory issued November 26 at 10:51PM PST until November 28 at 9:00AM PST by NWS San Francisco CA

* WHAT...For the first Frost Advisory, temperatures as low as 32 will result in frost formation. For the second Frost Advisory, temperatures as low as 32 will result in frost formation. * WHERE...The East Bay Hills and Valleys, The Salinas and Carmel Valleys and Hollister Area, Most of San Benito County and the Cholame Hills in Southeast Monterey County, North Bay Interior Mountains, North Bay Interior Valleys, and Eastern Santa Clara Hills. * WHEN...For the first Frost Advisory, from 10 PM Wednesday to 9 AM PST Thursday. For the second Frost Advisory, from 10 PM Thursday to 9 AM PST Friday. * IMPACTS...Cold conditions will be hazardous to sensitive populations such as unhoused individuals. Cold Conditions can lead to hypothermia with prolonged exposure.

Frost Advisory issued November 26 at 10:51PM PST until November 29 at 9:00AM PST by NWS San Francisco CA

* WHAT...For the first Frost Advisory, temperatures as low as 32 will result in frost formation. For the second Frost Advisory, temperatures as low as 32 will result in frost formation. * WHERE...The East Bay Hills and Valleys, The Salinas and Carmel Valleys and Hollister Area, Most of San Benito County and the Cholame Hills in Southeast Monterey County, North Bay Interior Mountains, North Bay Interior Valleys, and Eastern Santa Clara Hills. * WHEN...For the first Frost Advisory, from 10 PM Wednesday to 9 AM PST Thursday. For the second Frost Advisory, from 10 PM Thursday to 9 AM PST Friday. * IMPACTS...Cold conditions will be hazardous to sensitive populations such as unhoused individuals. Cold Conditions can lead to hypothermia with prolonged exposure.

Dense Fog Advisory issued November 26 at 9:12PM PST until November 27 at 10:00AM PST by NWS Hanford CA

* WHAT...Visibility one quarter mile or less in dense fog. * WHERE...Grapevine and Tehachapi, especially on Highway 58 through Tehachapi Pass and I-5 through the Grapevine * WHEN...Until 10 AM PST Wednesday. * IMPACTS...Low visibility could make driving conditions hazardous.