Update on Solar Cycle 24 – Hathaway's latest predictions show smallest sunspot cycle since 1906

The sun is currently showing two significant spots, though activity is generally quiet. Current SSN is 30, and Sunspot AR1667 (on the left) is in decay, and it is no longer crackling with C-class solar flares. Credit: SDO/HMI

First the current data from the NOAA Space Weather Prediction Center. The SSN rebounded moderately in January:

 Radio flux rebounded about the same amount as the SSN:

The Ap geomagnetic Index is still quite low, showing only a miniscule rebound.

NASA’s David Hathway updated his forecast page on Feb 1st and had this to say:

The current prediction for Sunspot Cycle 24 gives a smoothed sunspot number maximum of about 69 in the Fall of 2013. The smoothed sunspot number has already reached 67 (in February 2012)due to the strong peak in late 2011 so the official maximum will be at least this high and this late. We are currently over four years into Cycle 24. The current predicted and observed size makes this the smallest sunspot cycle since Cycle 14 which had a maximum of 64.2 in February of 1906.

Here is the latest Hathaway graphic:

Other data of interest from the WUWT Solar Reference Page:

I find the fact that TSI has been decreasing over the last three months curious.

SOURCE Solar Radiation & Climate Experiment – click the pic to view at source

The polar magnetic fields seem to be at the point of flipping now, suggesting solar max has been reached.

UPDATE: Credit where credit is due. Svalgaard et al predicted this scenario in 2004:

Sunspot cycle 24: Smallest cycle in 100 years?

Leif Svalgaard,1 Edward W. Cliver,2 and Yohsuke Kamide1

Received 3 October 2004; revised 10 November 2004; accepted 9 December 2004; published 11 January 2005.

Abstract:

Predicting the peak amplitude of the sunspot cycle is a

key goal of solar-terrestrial physics. The precursor method

currently favored for such predictions is based on the

dynamo model in which large-scale polar fields on the

decline of the 11-year solar cycle are converted to toroidal

(sunspot) fields during the subsequent cycle. The strength of

the polar fields during the decay of one cycle is assumed to

be an indicator of peak sunspot activity for the following

cycle. Polar fields reach their peak amplitude several years

after sunspot maximum; the time of peak strength is

signaled by the onset of a strong annual modulation of polar

fields due to the 71=4
tilt of the solar equator to the ecliptic

plane. Using direct polar field measurements, now available

for four solar cycles, we predict that the approaching solar

cycle 24 (
2011 maximum) will have a peak smoothed

monthly sunspot number of 75 ± 8, making it potentially the

smallest cycle in the last 100 years. Citation: Svalgaard, L.,

E. W. Cliver, and Y. Kamide (2005), Sunspot cycle 24: Smallest

cycle in 100 years?, Geophys. Res. Lett., 32, L01104, doi:10.1029/

2004GL021664.