West Coast Fog: CIMSS Fog / Low Cloud and CIRA WRF Fog Product Utility

This morning on the West Coast, Los Angeles Center, and particularly San Francisco Center, experienced a number of ground delays due to low ceilings. The CIRA fog difference WRF forecast showed low ceilings impacting both centers in the morning but dissipating around 1700 UTC. However, the imagery from the CIMSS Low Cloud/Fog product showed that the low ceilings did not actually dissipate until around 1800 UTC and after along the Southern CA Coast. In this case, both products showed some good utility for West Coast fog events, and much interest was shown by a forecaster who works the FA desks here at the AWC, often having to issue AIRMETs for low clouds and stratus in this area.

120613 1300-1800 UTC CIRA WRF Fog forecast

120613 1300-1600 UTC CIMSS Low Cloud/Fog product