IFR and GeoColor validation

An interesting ceiling and visibility setup occurred this morning on the West Coast. As per usual in the coastal California area, marine stratus moved onshore causing ceiling and visibility issues. Below are the GOES-R IFR probabilities from 1000 -1400 UTC this morning.

20150810 1000 - 1400 UTC GOES-W IFR probabilities

Note the dramatic drop in probabilities off shore, from nearly 100% to less than 50%. Observations (not shown here) still indicated IFR conditions just onshore, so the question became, is the IFR product accurate and ceilings are lifting offshore? Or is something else going on?

To answer that question, the GeoColor imagery was explored. Below is an animation from 1030 - 1500 UTC.

20150810 1030 - 1500 UTC GeoColor

The GeoColor image highlights low clouds in pink during the night and provides a visible image during the day. Note the marine stratus off the coast of the California. More significantly, note the area of higher clouds in white proceeding east. This area moved over the layer of low clouds, preventing any satellite retrievals to be used in the IFR probabilities. The loss of this data and reliance only on model inputs is what caused the dramatic decrease in probabilities.