Diamond Bar 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 Diamond Bar.

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

High Surf Advisory issued November 14 at 2:04PM PST until November 16 at 11:00AM PST by NWS San Francisco CA

* WHAT...For the Coastal Flood Advisory, minor coastal flooding expected. For the High Surf Advisory, large breaking waves of 12 to 15 ft with up to 18 ft along steep NW facing beaches. * WHERE...San Francisco County. * WHEN...For the Coastal Flood Advisory, from 7 AM this morning to 4 PM PST Monday. For the High Surf Advisory, from 7 AM this morning to 11 AM PST Saturday. San Francisco highest tides are today 6.72 ft at 9:26 am, Friday 6.95 ft at 10:04 am, Saturday 7.01 ft at 10:43 am, Sunday 6.89 ft at 11:26 am and Monday 6.6 ft at 12:11 pm. * IMPACTS...For the coastal flood advisory, flooding of lots, parks, and roads with only isolated road closures expected. Dangerous swimming and surfing conditions and localized beach erosion. For the High Surf Advisory, Dangerous swimming and surfing conditions and localized beach erosion. 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.

High Surf Advisory issued November 14 at 2:04PM PST until November 16 at 11:00AM PST by NWS San Francisco CA

* WHAT...Large breaking waves of 12 to 15 ft with up to 18 ft along steep NW facing beaches. * WHERE...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...From 7 AM this morning to 11 AM PST Saturday. * IMPACTS...Dangerous swimming and surfing conditions and localized beach erosion. 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.

Coastal Flood Advisory issued November 14 at 2:04PM PST until November 18 at 4:00PM PST by NWS San Francisco CA

* WHAT...For the Coastal Flood Advisory, minor coastal flooding expected. For the High Surf Advisory, large breaking waves of 12 to 15 ft with up to 18 ft along steep NW facing beaches. * WHERE...San Francisco County. * WHEN...For the Coastal Flood Advisory, from 7 AM this morning to 4 PM PST Monday. For the High Surf Advisory, from 7 AM this morning to 11 AM PST Saturday. San Francisco highest tides are today 6.72 ft at 9:26 am, Friday 6.95 ft at 10:04 am, Saturday 7.01 ft at 10:43 am, Sunday 6.89 ft at 11:26 am and Monday 6.6 ft at 12:11 pm. * IMPACTS...For the coastal flood advisory, flooding of lots, parks, and roads with only isolated road closures expected. Dangerous swimming and surfing conditions and localized beach erosion. For the High Surf Advisory, Dangerous swimming and surfing conditions and localized beach erosion. 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.

Coastal Flood Advisory issued November 14 at 2:04PM PST until November 18 at 4:00PM PST by NWS San Francisco CA

* WHAT...Minor coastal flooding expected. * WHERE...North Bay Interior Valleys and San Francisco Bay Shoreline Counties along the immediate San Francisco Bay. * WHEN...From 7 AM this morning to 4 PM PST Monday. San Francisco highest tides are today 6.72 ft at 9:26 am, Friday 6.95 ft at 10:04 am, Saturday 7.01 ft at 10:43 am, Sunday 6.89 ft at 11:26 am and Monday 6.6 ft at 12:11 pm. * IMPACTS...Flooding of lots, parks, and roads with only isolated road closures expected.

Wind Advisory issued November 14 at 1:59PM PST until November 16 at 4:00AM PST by NWS Hanford CA

* WHAT...Northwest winds 25 to 35 mph with gusts up to 50 mph expected. * WHERE...Mojave Desert Slopes. * WHEN...From 1 AM Friday to 4 AM PST Saturday. * IMPACTS...Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. * ADDITIONAL DETAILS...Highways affected include, but are not limited to Highway 14, Highway 178, and Highway 58.

Winter Weather Advisory issued November 14 at 1:58PM PST until November 15 at 10:00PM PST by NWS Sacramento CA

* WHAT...Snow expected above 5500 feet. Snowfall accumulations through Friday of 4 to 10 inches, with locally higher amounts up to 12 inches over the peaks. Winds gusting up to 30 mph. * WHERE...West Slope Northern Sierra Nevada and Western Plumas County/Lassen Park above 5500 feet. * WHEN...Until 10 PM PST Friday. * IMPACTS...Plan on slick travel conditions, snow covered roads, chain controls, and travel delays. These hazardous conditions may impact commutes through Friday. Gusty winds could bring down tree branches. * ADDITIONAL DETAILS...Snow levels will be 5000 to 6000 feet, before lowering to 4500 to 5500 feet tonight. Heaviest period of snowfall expected tonight into Friday morning.

Wind Advisory issued November 14 at 1:03PM PST until November 15 at 7:00PM PST by NWS Las Vegas NV

* WHAT...West winds 25 to 35 mph with gusts up to 45 mph expected. * WHERE...Western Mojave Desert. * WHEN...From 7 AM to 7 PM PST Friday. * IMPACTS...Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. Reduced visibility in blowing dust and sand.

Winter Weather Advisory issued November 14 at 12:56PM PST until November 15 at 1:00PM PST by NWS Reno NV

* WHAT...Snow. Snow accumulations up to 3 inches above 5500 feet, with a dusting possible below 5500 feet. * WHERE...Lassen-Eastern Plumas-Eastern Sierra Counties. * WHEN...From 7 PM this evening to 1 PM PST Friday. * IMPACTS...Plan on slippery road conditions. The hazardous conditions could impact the Thursday evening and Friday morning commutes.

Winter Weather Advisory issued November 14 at 12:56PM PST until November 15 at 7:00PM PST by NWS Reno NV

* WHAT...Snow. Snow accumulations 1 to 3 inches below 6500 feet and 6 to 10 inches above 6500 feet. * WHERE...Greater Lake Tahoe Area, and Mono County. * WHEN...From midnight tonight to 7 PM PST Friday. * IMPACTS...Plan on slippery road conditions. The hazardous conditions could impact the Friday morning and evening commutes.

Winter Weather Advisory issued November 14 at 12:48PM PST until November 15 at 10:00PM PST by NWS Hanford CA

* WHAT...Snow expected. Total snow accumulations up to 6 inches and up to 11 inches at the higher elevations. * WHERE...A portion of central California. * WHEN...From 4 PM this afternoon to 10 PM PST Friday. * IMPACTS...Travel could be very difficult to impossible. The hazardous conditions could impact the Thursday evening and Friday morning commutes.

Winter Weather Advisory issued November 14 at 12:27PM PST until November 15 at 10:00PM PST by NWS San Diego CA

* WHAT...Total snow accumulations 1 to 3 inches, locally near 4 inches from Running Springs to Big Bear Lake. * WHERE...San Bernardino County Mountains and Riverside County Mountains above 5,550 feet. * WHEN...From 9 PM this evening to 10 PM PST Friday. * IMPACTS...Plan on slippery road conditions. The hazardous conditions could impact the morning or evening commute. * ADDITIONAL DETAILS...Best chance for snow showers will occur on Friday. Light snow may fall on Saturday.

Wind Advisory issued November 14 at 11:50AM PST until November 16 at 1:00AM PST by NWS Phoenix AZ

* WHAT...West winds 20 to 30 mph with gusts up to 50 to 55 mph expected. * WHERE...Southwest corner of Imperial County, and Western Imperial County. * WHEN...From 7 PM this evening to 1 AM PST Saturday. * IMPACTS...Difficult driving conditions, especially for larger vehicles traveling along roads with crosswinds. Light, unsecured objects may become airborne.

High Surf Advisory issued November 14 at 11:33AM PST until November 16 at 12:00PM PST by NWS Los Angeles/Oxnard CA

* WHAT...Large breaking waves will build to 5 to 7 feet this evening, and to 6 to 8 feet with local sets to 10 feet late tonight and Friday. High surf will continue into Saturday morning, then surf will slowly subside. There is a high risk of dangerous rip currents this afternoon through Saturday. * WHERE...Ventura County Beaches. * WHEN...From 9 PM this evening to noon PST Saturday. * IMPACTS...There is an increased risk for ocean drowning. Rip currents can pull swimmers and surfers out to sea. Large breaking waves can cause injury, wash people off beaches and rocks, and capsize small boats near shore. * ADDITIONAL DETAILS...There may be some nuisance to minor coastal flooding on exposed west-facing beaches a couple of hours on either side of the high tides Friday morning and Saturday morning. High tide Friday morning is around 800 AM PST, and high tide Saturday morning is around 835 AM PST.

High Surf Advisory issued November 14 at 11:33AM PST until November 16 at 12:00PM PST by NWS Los Angeles/Oxnard CA

* WHAT...Large breaking waves will build to 8 to 11 feet this afternoon, and to 9 to 13 feet with local sets to 15 feet tonight and Friday. High surf will continue into Saturday morning, then surf will slowly subside. There is a high risk of dangerous rip currents this afternoon through Saturday. * WHERE...San Luis Obispo County Beaches and Santa Barbara County Central Coast Beaches. * WHEN...From 3 PM this afternoon to noon PST Saturday. * IMPACTS...There is an increased risk for ocean drowning. Rip currents can pull swimmers and surfers out to sea. Large breaking waves can cause injury, wash people off beaches and rocks, and capsize small boats near shore. * ADDITIONAL DETAILS...Minor coastal flooding is possible on west and northwest-facing beaches a couple of hours on either side of the high tides Friday morning and Saturday morning. High tide Friday morning is around 830 AM PST, and high tide Saturday morning is around 910 AM PST.

Frost Advisory issued November 14 at 10:13AM PST until November 16 at 8:00AM PST by NWS San Francisco CA

* WHAT...Temperatures as low as 32 will result in frost formation. * WHERE...Interior Monterey County and the Santa Lucia Range, and Northern Salinas Valley/Hollister Valley and Carmel Valley. * WHEN...From midnight Friday Night to 8 AM PST Saturday. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered. Cold conditions will be hazardous to sensitive populations such as unhoused individuals. Cold Conditions can lead to hypothermia with prolonged exposure.

Freeze Warning issued November 14 at 10:13AM PST until November 16 at 8:00AM PST by NWS San Francisco CA

* WHAT...Sub-freezing temperatures as low as 28 expected. * WHERE...Most of San Benito County and the Cholame Hills in Southeast Monterey County, and Southern Salinas Valley/Arroyo Seco and Lake San Antonio. * WHEN...From midnight Friday Night to 8 AM PST Saturday. * IMPACTS...Frost and freeze conditions could kill crops, other sensitive vegetation and possibly damage unprotected outdoor plumbing. Cold conditions will be hazardous to sensitive populations such as unhoused individuals.

Freeze Warning issued November 14 at 10:13AM PST until November 16 at 8:00AM PST by NWS San Francisco CA

* WHAT...Sub-freezing temperatures as low as 30 expected. * WHERE...North Bay Interior. * WHEN...From midnight Friday Night to 8 AM PST Saturday. * IMPACTS...Frost and freeze conditions could kill crops, other sensitive vegetation and possibly damage unprotected outdoor plumbing. Cold conditions will be hazardous to sensitive populations such as unhoused individuals. * ADDITIONAL DETAILS...Freezing conditions are most likely in the valleys of Sonoma County, with frost conditions possible in Napa Valley and the higher elevations.

Wind Advisory issued November 14 at 8:49AM PST until November 15 at 10:00AM PST by NWS Los Angeles/Oxnard CA

* WHAT...Northwest winds 20 to 30 mph with gusts up to 45 mph expected. * WHERE...Santa Barbara County Southwestern Coast, Santa Ynez Mountains Eastern Range, and Santa Ynez Mountains Western Range. * WHEN...From 4 PM this afternoon to 10 AM PST Friday. * IMPACTS...Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result.