The latest consumer confidence index figure is an anomaly

I must admit that the Conference Board's US consumer confidence index released yesterday was quite mystifying. Not only did it come in way below expectations (46 vs. an expected mid-50s figure). When a figure hits a 16-month high one month (as this index did in jan) and a 10-month low the next (as this one did in feb), there must be some anomaly somewhere. The 16-month high in Jan appears ok as it is consistent with the trend of the previous months, so it's the current Feb figure that should be considered questionable, particularly as the University of Michigan consumer sentiment index released in Feb appears to be ok.

Unseasonal storms on the Atlantic seaboard could be part of the explanation (apparently the index dipped in jan 1996 when there was stormy weather).

Isn't consumer spend 70 % of the US economy? Doesn't a huge dip mean the economic recovery may have gone off the tracks?

No and No.

First, the 70% figure for consumer spend as a proportion of the US economy is a huge overestimate (see for example, here).

Second, a blip in consumer confidence means very little, particularly when it is an outlier from a trend that has been fairly healthy for several months. At the most, this dip may mean that the speed and quality of the recovery may be a little lower than previously thought, and does not negate the existence of a recovery.