Weather Alerts for California

Recent Locations: Penryn, PA Donner, LA Simi Valley, CA

Current Alerts for Simi Valley, CA: Extreme Heat Warning Heat Advisory

1. Extreme Heat Warning for: Coalinga - Avenal; Fresno-Clovis; West Side Mountains South of 198; Buena Vista; Bakersfield; South End San Joaquin Valley; Fresno-Tulare Foothills; South End Sierra Foothills

2. Extreme Heat Warning for: Cuyama Valley; Santa Clarita Valley; Santa Lucia Mountains; Southern Salinas Valley; San Luis Obispo County Interior Valleys; San Luis Obispo County Mountains; Santa Ynez Valley; Santa Barbara County Interior Mountains; Western Santa Monica Mountains Recreational Area; Calabasas and Agoura Hills; Western San Fernando Valley; Eastern San Fernando Valley; Southeastern Ventura County Valleys; Santa Susana Mountains; Southern Ventura County Mountains; Northern Ventura County Mountains; Interstate 5 Corridor; Western San Gabriel Mountains and Highway 14 Corridor; Eastern San Gabriel Mountains; Western Antelope Valley Foothills; Eastern Antelope Valley Foothills; Antelope Valley; Los Angeles County San Gabriel Valley

3. Extreme Heat Warning for: Santa Ynez Mountains Western Range; Santa Ynez Mountains Eastern Range; Los Angeles County Inland Coast including Downtown Los Angeles; Eastern Santa Monica Mountains Recreational Area

4. Extreme Heat Warning for: Western Siskiyou County; Central Siskiyou County

5. Flash Flood Warning for: Mariposa, CA; Tuolumne, CA

6. Flood Advisory for: Kern, CA

7. Flood Advisory for: Los Angeles, CA

8. Flood Advisory for: Mariposa, CA

9. Flood Advisory for: Riverside, CA; San Diego, CA

10. Flood Advisory for: Tulare, CA

11. Flood Advisory for: Tulare, CA

12. Flood Watch for: Greater Lake Tahoe Area; Greater Lake Tahoe Area; Greater Reno-Carson City-Minden Area; Northern Washoe County

13. Flood Watch for: Mono; Mineral and Southern Lyon Counties

14. Flood Watch for: Yosemite NP outside of the valley; Upper San Joaquin River; Kaiser to Rodgers Ridge; Kings Canyon NP

15. Heat Advisory for: Lake Casitas; Ojai Valley; Central Ventura County Valleys

16. Heat Advisory for: West Side of Fresno and Kings Counties; Caruthers - San Joaquin - Selma; Buttonwillow - Lost Hills - I5; Delano-Wasco-Shafter; Hanford - Corcoran - Lemoore; Visalia - Porterville - Reedley; Southeast San Joaquin Valley; Kern River Valley

17. Red Flag Warning for: Shasta-Trinity National Forest in Siskiyou County; Umpqua National Forest; Western Rogue Basin including the Illinois Valley; Eastern Rogue Valley

18. Red Flag Warning for: Trinity

19. Red Flag Warning for: Western Klamath National Forest; Central Siskiyou County Including Shasta Valley; Siskiyou County from the Cascade Mountains East and South to Mt Shasta; Modoc County Except for the Surprise Valley; Siskiyou Mountains; Southern Oregon Cascades; Klamath Basin and the Fremont-Winema National Forest; South Central Oregon Desert including the BLM Land in Eastern Lake and Western Harney Counties

20. Red Flag Warning for: Western Klamath National Forest; Central Siskiyou County Including Shasta Valley; Siskiyou County from the Cascade Mountains East and South to Mt Shasta; Modoc County Except for the Surprise Valley; Siskiyou Mountains; Southern Oregon Cascades; Klamath Basin and the Fremont-Winema National Forest; South Central Oregon Desert including the BLM Land in Eastern Lake and Western Harney Counties

21. Special Weather Statement for: Kings Canyon NP

22. Special Weather Statement for: Lassen-Eastern Plumas-Eastern Sierra Counties; Greater Reno-Carson City-Minden Area

23. Special Weather Statement for: Lassen-Eastern Plumas-Eastern Sierra Counties; Greater Reno-Carson City-Minden Area; Northern Washoe County

24. Special Weather Statement for: Riverside County Mountains; San Diego County Mountains; San Diego County Deserts

25. Special Weather Statement for: Yosemite NP outside of the valley

26. Special Weather Statement for: Yosemite NP outside of the valley

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 are Cirrostratus Clouds?

Home - Education - Cloud Types - Cirrostratus Clouds

Next Topic: Cirrus Clouds

Cirrostratus clouds are high, thin clouds that form above 20,000 feet and are made mostly of ice crystals. They sometimes look like giant feathers, horse tails, or curls of hair in the sky. These clouds are pushed by the jet stream and can move at high speeds reaching 100 mph.

What do they indicate?
They indicate that a precipitation is likely within 24 hours.

Next Topic: Cirrus Clouds

Weather Topic: What is Condensation?

Home - Education - Precipitation - Condensation

Next Topic: Contrails

Condensation is the process which creates clouds, and therefore it is a crucial process in the water cycle. Condensation is the change of matter from a state of gas into a state of liquid, and it happens because water molecules release heat into the atmosphere and become organized into a more closely packed structure, what we might see as water droplets.

Water is always present in the air around us as a vapor, but it's too small for us to see. When water undergoes the process of condensation it becomes organized into visible water droplets. You've probably seen condensation happen before on the surface of a cold drink!

Next Topic: Contrails