Weather Alerts for California

Recent Locations: Leesburg, FL Rulo, NE Pala, CA

1. 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

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

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

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

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

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

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

8. 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

9. Winter Storm Watch for: Mono

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

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

12. 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

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

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

15. Winter Storm Watch for: Western Siskiyou County

16. Winter Storm Watch for: Western Siskiyou County

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

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Current U.S. National Radar--Current

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National Weather Forecast--Current

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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 are Contrails?

Home - Education - Cloud Types - Contrails

Next Topic: Cumulonimbus Clouds

A contrail is an artificial cloud, created by the passing of an aircraft.

Contrails form because water vapor in the exhaust of aircraft engines is suspended in the air under certain temperatures and humidity conditions. These contrails are called exhaust contrails.

Another type of contrail can form due to a temporary reduction in air pressure moving over the plane's surface, causing condensation. These are called aerodynamic contrails.

When you can see your breath on a cold day, it is also because of condensation. The reason contrails last longer than the condensation from your breath is because the water in contrails freezes into ice particles.

Next Topic: Cumulonimbus Clouds

Weather Topic: What are Cumulus Clouds?

Home - Education - Cloud Types - Cumulus Clouds

Next Topic: Drizzle

Cumulus clouds are fluffy and textured with rounded tops, and may have flat bottoms. The border of a cumulus cloud is clearly defined, and can have the appearance of cotton or cauliflower.

Cumulus clouds form at low altitudes (rarely above 2 km) but can grow very tall, becoming cumulus congestus and possibly the even taller cumulonimbus clouds. When cumulus clouds become taller, they have a greater chance of producing precipitation.

Next Topic: Drizzle