Weather Alerts for California

Recent Locations: Philadelphia, PA Columbus, OH Los Angeles, CA

1. Beach Hazards Statement for: Coastal Del Norte; Northern Humboldt Coast; Southwestern Humboldt; Mendocino Coast

2. Beach Hazards Statement for: San Francisco; Coastal North Bay Including Point Reyes National Seashore; San Francisco Peninsula Coast; Southern Monterey Bay and Big Sur Coast

3. Dense Fog Advisory for: Los Banos - Dos Palos; Merced - Madera - Mendota; Planada - Le Grand - Snelling; West Side of Fresno and Kings Counties; Caruthers - San Joaquin - Selma; Fresno-Clovis; Buttonwillow - Lost Hills - I5; Delano-Wasco-Shafter; Hanford - Corcoran - Lemoore; Visalia - Porterville - Reedley; Bakersfield; Southeast San Joaquin Valley

4. High Surf Advisory for: San Luis Obispo County Beaches; Santa Barbara County Central Coast Beaches

5. Wind Advisory for: Northern Sacramento Valley; Central Sacramento Valley; Southern Sacramento Valley

6. Winter Storm Watch for: Del Norte Interior; Northern Humboldt Interior; Southern Humboldt Interior

7. Winter Storm Watch for: Eastern Sierra Slopes of Inyo County

8. Winter Storm Watch for: Greater Lake Tahoe Area; Greater Lake Tahoe Area

9. Winter Storm Watch for: Lassen-Eastern Plumas-Eastern Sierra Counties

10. Winter Storm Watch for: Mariposa-Madera Lower Sierra; Fresno-Tulare Lower Sierra; South End of the Lower Sierra; Yosemite NP outside of the valley; Yosemite Valley; San Joaquin River Canyon; Upper San Joaquin River; Kaiser to Rodgers Ridge; Kings Canyon NP; Grant Grove Area; Sequoia NP; South End of the Upper Sierra; Piute Walker Basin

11. Winter Storm Watch for: Mono

12. Winter Storm Watch for: Northern Trinity; Southern Trinity

13. Winter Storm Watch for: Northwestern Mendocino Interior; Northeastern Mendocino Interior; Northern Lake County; Southern Lake County

14. Winter Storm Watch for: Shasta Lake Area / Northern Shasta County; Burney Basin / Eastern Shasta County; Mountains Southwestern Shasta County to Western Colusa County; Northeast Foothills/Sacramento Valley; Motherlode; Western Plumas County/Lassen Park; West Slope Northern Sierra Nevada

15. Winter Storm Watch for: South Central Siskiyou County; North Central and Southeast Siskiyou County

16. Winter Storm Watch for: Western Siskiyou County

17. Winter Storm Watch for: White Mountains of Inyo County

Want more detail? Get the Complete 7 Day and Night Detailed Forecast!

Current U.S. National Radar--Current

The Current National Weather Radar is shown below with a UTC Time (subtract 5 hours from UTC to get Eastern Time).

National Weather Forecast--Current

The Current National Weather Forecast and National Weather Map are shown below.

National Weather Forecast for Tomorrow

Tomorrow National Weather Forecast and Tomorrow National Weather Map are show below.

North America Water Vapor (Moisture)

This map shows recent moisture content over North America. Bright and colored areas show high moisture (ie, clouds); brown indicates very little moisture present; black indicates no moisture.

Weather Topic: What is Precipitation?

Home - Education - Precipitation - Precipitation

Next Topic: Rain

Precipitation can refer to many different forms of water that may fall from clouds. Precipitation occurs after a cloud has become saturated to the point where its water particles are more dense than the air below the cloud.

In most cases, precipitation will reach the ground, but it is not uncommon for precipitation to evaporate before it reaches the earth's surface. When precipitation evaporates before it contacts the ground it is called Virga. Graupel, hail, sleet, rain, drizzle, and snow are forms of precipitation, but fog and mist are not considered precipitation because the water vapor which constitutes them isn't dense enough to fall to the ground.

Next Topic: Rain

Weather Topic: What are Shelf Clouds?

Home - Education - Cloud Types - Shelf Clouds

Shelf Clouds Next Topic: Sleet

A shelf cloud is similar to a wall cloud, but forms at the front of a storm cloud, instead of at the rear, where wall clouds form.

A shelf cloud is caused by a series of events set into motion by the advancing storm; first, cool air settles along the ground where precipitation has just fallen. As the cool air is brought in, the warmer air is displaced, and rises above it, because it is less dense. When the warmer air reaches the bottom of the storm cloud, it begins to cool again, and the resulting condensation is a visible shelf cloud.

Next Topic: Sleet