Heavy Rainfall to Bring Flooding Threat to California; Heavy Snow in the Sierra

A strong atmospheric river will bring heavy rainfall to California through the holiday week. The heaviest rainfall is expected on Wednesday in the Los Angeles Basin. Flash and urban flooding is possible. A prolonged heavy snowfall is expected in the Sierra Nevada from the atmospheric river, raising concerns for major snow‐load impacts. Travel may be difficult to impossible over the passes. Read More >

Summer Briefing

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Local Storm Reports

Severe Weather Outlooks

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Day 2

Day 3

Information on SPC's Severe Thunderstorm Risk Categories

River Flooding

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Precipitation Forecast

1-Day Rainfall

2-Day Rainfall

3-Day Rainfall

Additional Weather Elements

(mouse over day or period to see map below)

Max Temperature	Day 1		Day 2		Day 3		Day 4		Day 5
Min Temperature	Day 1		Day 2		Day 3		Day 4		Day 5
Heat Index	Period 1	Period 2	Period 3	Period 4	Period 5	Period 6	Period 7
Max Wind Gust	Period 1	Period 2	Period 3	Period 4	Period 5	Period 6	Period 7	Period 8	Period 9
Chance of Precip	Period 1	Period 2	Period 3	Period 4	Period 5	Period 6	Period 7	Period 8	Period 9
Recent Lightning	Yesterday	2 Days Ago	3 Days Ago	4 Days Ago	5 Days Ago	6 Days Ago	7 Days Ago	8 Days Ago

Forecast Timelines

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Detailed Point Forecast

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Climate Outlooks

8-14 Day Temp Outlook

8-14 Day Precip Outlook

Drought Monitor

Summer Weather Definitions

Tornado or Severe Thunderstorm WATCH:

Conditions are favorable for the development of tornadoes, large hail, and/or damaging winds.

Tornado WARNING:

A tornado has been detected on radar or sighted by trained spotters.

Severe Thunderstorm WARNING:

A severe thunderstorm has been detected on radar or reported by trained spotters. A severe thunderstorm is a storm that produces hail 1 inch or larger and/or winds 58 mph or greater

Severe Thunderstorm Outlook Terms:

Marginal Risk:

Isolated severe thunderstorms are possible.
Slight Risk:

Scattered or short-lived severe thunderstorms are possible.
Enhanced Risk:

Numerous or persistent severe thunderstorms are possible.
Moderate Risk:

Widespread, long-lived, and intense severe thunderstorms are likely.
High Risk:

Widespread, long-lived, and particularly intense severe thunderstorms are expected.

Flood WATCH:

Conditions are favorable for flooding.

Flash Flood WARNING:

Life-threatening flooding is detected on radar, indicated by stream gauges, or reported by storm spotters. A flash flood is a flood that occurs very quickly; it is caused by heavy rainfall over a short period of time or from a dam break.

Flood WARNING:

Rivers overflowing their banks or water covering a normally dry area. Floods are usually caused by heavy rain over a long period of time, rapidly melting snow, or ice jams.

Extreme Heat WARNING:

Heat index 105 degrees or higher, with a minimum heat index of 75 degrees for 48 hours or longer; or heat index of 100 degrees or higher for four consecutive days.

Heavy Rainfall to Bring Flooding Threat to California; Heavy Snow in the Sierra

Summer Briefing

Summer Briefing

To view hazards legend: Stop the loop, step to the end, and use the alerts drop-down. View full radar page here.

Click here for a static hazards map.

Local Storm Reports

Severe Weather Outlooks

Day 1

Day 2

Day 3

Information on SPC's Severe Thunderstorm Risk Categories

River Flooding

Open in New Tab

Precipitation Forecast

1-Day Rainfall

2-Day Rainfall

3-Day Rainfall

Additional Weather Elements

Forecast Timelines

Single Site Timelines

Detailed Point Forecast

Climate Outlooks

8-14 Day Temp Outlook

8-14 Day Precip Outlook

Drought Monitor

Summer Weather Definitions

Tornado or Severe Thunderstorm WATCH:

Conditions are favorable for the development of tornadoes, large hail, and/or damaging winds.

Tornado WARNING:

A tornado has been detected on radar or sighted by trained spotters.

Severe Thunderstorm WARNING:

A severe thunderstorm has been detected on radar or reported by trained spotters. A severe thunderstorm is a storm that produces hail 1 inch or larger and/or winds 58 mph or greater

Severe Thunderstorm Outlook Terms:

Marginal Risk:

Isolated severe thunderstorms are possible.

Slight Risk:

Scattered or short-lived severe thunderstorms are possible.

Enhanced Risk:

Numerous or persistent severe thunderstorms are possible.

Moderate Risk:

Widespread, long-lived, and intense severe thunderstorms are likely.

High Risk:

Widespread, long-lived, and particularly intense severe thunderstorms are expected.

Flood WATCH:

Conditions are favorable for flooding.

Flash Flood WARNING:

Life-threatening flooding is detected on radar, indicated by stream gauges, or reported by storm spotters. A flash flood is a flood that occurs very quickly; it is caused by heavy rainfall over a short period of time or from a dam break.

Flood WARNING:

Rivers overflowing their banks or water covering a normally dry area. Floods are usually caused by heavy rain over a long period of time, rapidly melting snow, or ice jams.

Extreme Heat WARNING:

Heat index 105 degrees or higher, with a minimum heat index of 75 degrees for 48 hours or longer; or heat index of 100 degrees or higher for four consecutive days.

Heat ADVISORY:

Heat index 100 degrees or higher; or heat index between 95 and 100 degrees for four consecutive days.