Weather Alerts for California

Recent Locations: Martinez, CA

1. Air Quality Alert for: San Bernardino and Riverside County Valleys-The Inland Empire

2. Beach Hazards Statement for: San Diego County Coastal Areas; Orange County Coastal

3. Beach Hazards Statement for: Ventura County Beaches; Malibu Coast; Los Angeles County Beaches

4. Lake Wind Advisory for: Lassen-Eastern Plumas-Eastern Sierra Counties; Mono; Mineral and Southern Lyon Counties; Greater Reno-Carson City-Minden Area; Western Nevada Basin and Range including Pyramid Lake

5. Red Flag Warning for: Eastern Portion of Shasta/Trinity NF; Northern Sacramento Valley to Southern Tehama County Line Below 1000 Ft; Central Sacramento Valley including Glenn/Colusa/Yuba/Northern Sutter/Butte County Below 1000 Ft; Southeast Edge Shasta/Trinity NF and Western Portions of Tehama/Glenn RU; Eastern Mendocino NF

6. Red Flag Warning for: Southern Mono County; Northern Sierra Front - Carson City/Douglas/Storey/Southern Washoe/Eastern Lyon/Far Southern Lassen Counties; Southern Sierra Front - Alpine/Northern Mono/Southern Lyon/Western Mineral Counties; Lahontan Basin - Churchill and Eastern Mineral Counties

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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