The coldest air of the season has plunged into the central part of the US. And as noted before, extreme cold does have an influence on the IFR Probability fields because of how the pseudo-emissivity is computed. Consider this effect of cold on the fields as you interpret them. Note also that in the daytime, when visible imagery can be used to augment the cloud mask, IFR Probabilities are low in very cold airmasses.