Solar Cycle Progression

The NOAA/Space Weather Prediction Center Solar Cycle Progression page provides a useful source of information on Solar Cycle 24.

The latest announcement issued March 2, 2009 says:

The Solar Cycle 24 Prediction Panel has not issued any updates to their prediction. However, the Space Weather Prediction Center, and the Chair of the Prediction Panel decided to implement what they believe to be an obvious change to the plotted data. The two predictions, of maximum being either a SSN of 90 or a SSN of 140 remain intact.

Once the date of solar minimum is known, that is all the information needed to arrive at a prediction curve. The panel prediction of solar minimum in March, 2008 has been eclipsed. Minimum will now occur no earlier than August, 2008.

For every month beyond March 2008 that minimum slips, it is necessary to shift the prediction curves by the same amount. SWPC commenced doing so in mid-February and will continue to do so, unless or until the prediction panel sets a new predicted date for the time of solar minimum.

NOAA/Space Weather Prediction Center - Solar Cycle Progression
http://www.swpc.noaa.gov/SolarCycle/index.html