Weather Alerts for California

Recent Locations: Wichita, KS Cumming, GA San Mateo, CA

1. Air Quality Alert for: Imperial County Southwest; Chuckwalla Mountains; Imperial County Southeast; Imperial County West; Imperial Valley; Palo Verde Valley

2. Freeze Warning for: Del Norte Interior; Northern Humboldt Interior; Southern Humboldt Interior; Northern Trinity; Southern Trinity; Northwestern Mendocino Interior; Northeastern Mendocino Interior; Northern Lake County; Southern Lake County

3. Freeze Warning for: Lassen-Eastern Plumas-Eastern Sierra Counties

4. Freeze Warning for: Surprise Valley California; Northern Washoe County

5. Freeze Warning for: Western Siskiyou County; Eastern Curry County and Josephine County; Jackson County

6. Frost Advisory for: Coastal Del Norte; Northern Humboldt Coast; Southwestern Humboldt; Mendocino Coast; Southwestern Mendocino Interior

7. Wind Advisory for: Apple and Lucerne Valleys

8. Wind Advisory for: Indian Wells Valley; Mojave Desert

9. Wind Advisory for: Mojave Desert Slopes

10. Wind Advisory for: San Bernardino and Riverside County Valleys-The Inland Empire; San Bernardino County Mountains; Santa Ana Mountains and Foothills; Orange County Inland

11. Wind Advisory for: San Luis Obispo County Beaches; Santa Barbara County Central Coast Beaches

12. Wind Advisory for: Santa Barbara County Southwestern Coast; Santa Ynez Mountains Western Range; Santa Ynez Mountains Eastern Range

13. Wind Advisory for: Santa Lucia Mountains

14. Wind Advisory for: South-Central Shasta County Including Redding Metro; Northern Sacramento Valley in Tehama County; Central Glenn County Including Interstate 5; Eastern Glenn County; Butte County Below 1000 ft; Central Colusa County Including Interstate 5; Eastern Colusa County; Sutter and Yuba Counties Below 1000 ft; Capay Hills of Yolo County and Vaca Hills of Solano County; Western Yolo County Including Capay Valley and Interstate 505; Central Yolo and Northeast Solano Counties Including Woodland and Davis; Sacramento Metro and Western El Dorado and Amador Counties; Central Solano County Including Fairfield and Vacaville; Southwestern Solano County Including Vallejo; Sacramento County Delta; San Joaquin County Delta

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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

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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