Severe Weather Threat in the North-central Great Plains

Strong to severe storms are expected to bring severe wind gusts and large hail across parts of South Dakota and Nebraska. Additional thunderstorm activity likely Sunday from the Northern Plains into the Upper Great Lakes. A fire weather threat continues from portions of the Great Basin into the Rockies. Read More >

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Warming Trend

SJ Valley Forecasts

Cold Water Safety

High temperatures throughout Central California this afternoon will be two to four degrees warmer than Thursday. Maximum temperatures across Central California Saturday afternoon will be near normal for this time of year.

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Upper Air Observations

Decoded Upper Level Winds
Plotted Upper Air Soundings

GOES Derived Atmospheric Vertical Soundings
Alternate Sources for Upper Air Soundings
Ohio State

California Wind Profiler Data Can be Found Here

Why Do Forecasters Still Rely on Weather Balloons?

Twice every day, from nearly 100 locations in the United States, the National Weather Service launches weather balloons, carrying instrument packages called radiosondes. Radiosonde sensors measure upper-air conditions such as atmospheric pressure, temperature and humidity, wind speed and direction. The data is important for aviation safety, and meteorologists use radiosonde information to prepare weather forecasts.