The Met office and certainty levels

Excerpt from this post:

...For those who are not used to the magnitude of anomalies, 0.15C is WAY OFF from the forecasted 0.54C. In fact, using the mean and std. deviation of the forecast we derived above, the UK Met office basically was saying that it was 99.99997% certain that the temperature would not go so low. Another way of saying this is that the Met office forecast implied 2,958,859:1 odds against the temperature being this low in 2007.

What are the odds that the Met office needs to rethink its certainty level?