Forecast Details for San Bruno, CA

Recent Locations: Prescott, AZ Broadalbin, NY San Bruno, CA

Today: Patchy fog before 8am. Otherwise, mostly cloudy, with a high near 57. Calm wind becoming south southwest 5 to 8 mph in the afternoon.

Tonight: A 10 percent chance of rain after 4am. Mostly cloudy, with a low around 53. South southeast wind around 10 mph, with gusts as high as 18 mph.

Sunday: A slight chance of rain before 4pm, then a chance of showers after 4pm. Cloudy, with a high near 58. South wind 10 to 16 mph, with gusts as high as 25 mph. Chance of precipitation is 30%. New precipitation amounts between a half and three quarters of an inch possible.

Sunday Night: Showers and thunderstorms likely before 10pm, then showers and possibly a thunderstorm between 10pm and 1am, then rain after 1am. Low around 51. South wind 6 to 9 mph. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.

Washington's Birthday: Rain. High near 54. Northeast wind 6 to 10 mph becoming southwest in the morning. Chance of precipitation is 100%. New precipitation amounts between a quarter and half of an inch possible.

Monday Night: Rain. Low around 47. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

Tuesday: Rain. High near 51. Chance of precipitation is 100%.

Tuesday Night: Rain. Mostly cloudy, with a low around 45.

Wednesday: Rain likely. Mostly cloudy, with a high near 52.

Wednesday Night: Rain likely. Mostly cloudy, with a low around 45.

Thursday: A chance of rain. Partly sunny, with a high near 53.

Thursday Night: A chance of rain. Mostly cloudy, with a low around 46.

Friday: A chance of rain. Partly sunny, with a high near 55.

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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

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North America Water Vapor (Moisture)

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Weather Topic: What is Sleet?

Home - Education - Precipitation - Sleet

Sleet Next Topic: Snow

Sleet is a form of precipitation in which small ice pellets are the primary components. These ice pellets are smaller and more translucent than hailstones, and harder than graupel. Sleet is caused by specific atmospheric conditions and therefore typically doesn't last for extended periods of time.

The condition which leads to sleet formation requires a warmer body of air to be wedged in between two sub-freezing bodies of air. When snow falls through a warmer layer of air it melts, and as it falls through the next sub-freezing body of air it freezes again, forming ice pellets known as sleet. In some cases, water droplets don't have time to freeze before reaching the surface and the result is freezing rain.

Next Topic: Snow

Weather Topic: What are Stratocumulus Clouds?

Home - Education - Cloud Types - Stratocumulus Clouds

Next Topic: Stratus Clouds

Stratocumulus clouds are similar to altocumulus clouds in their fluffy appearance, but have a slightly darker shade due to their additional mass.

A good way to distinguish the two cloud types is to hold your hand out and measure the size of an individual cloud; if it is the size of your thumb it is generally an altocumulus cloud, if it is the size of your hand it is generally a stratocumulus cloud.

It is uncommon for stratocumulus clouds to produce precipitation, but if they do it is usually a light rain or snow.

Next Topic: Stratus Clouds