An international panel of experts led by NOAA and sponsored by NASA has released a new prediction for the next solar cycle. Solar Cycle 24 will peak, they say, in May 2013 with a below-average number of sunspots. "If our prediction is correct, Solar Cycle 24 will have a peak sunspot number of 90, the lowest of any cycle since 1928 when Solar Cycle 16 peaked at 78," says panel chairman Doug Biesecker of the NOAA Space Weather Prediction Center. Read the full story here.
The Solar Cycle 24 Prediction Panel has agreed that solar minimum occurred in December, 2008 (which still qualifies as a prediction since the smoothed sunspot number is only valid through September 2008), while solar maximum is now expected to occur in May 2013.
The above plot of sunspot numbers shows the measured peak of the last solar cycle in blue and the predicted peak of the next solar cycle in red (credit: NOAA/Space Weather Prediction Center).
Predicting the behavior of a sunspot cycle is fairly reliable once the cycle is well underway (about 3 years after the minimum in sunspot number occurs), but prior to that time the predictions are less reliable. Planning for satellite orbits and space missions often require knowledge of solar activity levels years in advance. Read more about solar cycle predictions here.