Early this week, forecasts were predicting temperatures near 110 degrees in Sacramento for Saturday. But on Wednesday, most predictions were lowered to about 104.
Meteorologists take many things into account when forecasting, including satellite imagery and past temperatures trends. Much of the information is derived from sensors attached to weather balloons that are launched twice daily from about 50 National Weather Service offices across the U.S.
This week, the various computer models interpreting the data have been diverging. By midday Wednesday, the prediction for Saturday’s high temperature ranged from 100 to 111 degrees.
“It’s unusual to see what we’re seeing this weekend where it’s changing so much from one run to the next,” said meteorologist Darren Van Cleave at the National Weather Service office in Sacramento.
An unpredictable area of low pressure off the California coast is the cause of much of the model uncertainty. It remains to be seen whether the “low” and its associated cool air will move far enough west by Saturday to have much of an impact on Sacramento area temperatures.
The June 8 temperature record for Sacramento is 103 degrees.