A detailed study of advection sea fog formation to reduce the operational impacts along the Northern Gulf of Mexico

Abstract

This study creates rules of thumb for forecasting advection sea fog development and dissipation along the Northern Gulf of Mexico for the months of December through March. Surface observations from Tyndall AFB, Destin-Fort Walton Beach Airport, Eglin AFB, Hurlburt Field and Keesler AFB were used in conjunction with the National Data Buoy Centerαs marine sensors to determine the low-level atmospheric state and the sea surface temperatures during advection sea fog events at the five locations listed above. Forecasting rules of thumb were created and then modified to maximize forecasting effectiveness. The criteria examined include: sea surface temperature, wind speed and direction, air temperature and dewpoint spread, dewpoint and sea surface temperature spread. Data from December 1999 to March 2004 and from December 2005 to March 2006 was used for the Keesler AFB analysis. Data from February 2005 to March 2006 was used for the Tyndall AFB, Eglin AFB, Hurlburt Field and Destin-Fort Walton Beach analysis. Missing sea surface temperatures limited the amount of winter time advection sea fog seasons that could be examined. The averaged results from all of the locations indicate that fog with visibility less than or equal to three statute miles is present 86.8% of the time at the observing site within one hour of meeting the following criteria: sea surface temperature less than or equal to 18.7 degrees Celsius, onshore surface winds less than or equal to 12 knots or surface winds from any direction if the speed is less than or equal to three knots, surface air temperature minus surface dewpoint is less than or equal to one degrees Celsius and sea surface temperature minus surface dewpoint is less than or equal to 1.9 degrees Celsius. Results also indicate that fog is present 85.9% of the time at the observing site within two hours of meeting the following criteria: sea surface temperature less than or equal to 19.7 degrees Celsius, onshore surface winds less than or equal to 14 knots or surface winds from any direction if the speed is less than or equal to three knots, surface air temperature minus surface dewpoint is less than or equal to one degrees Celsius and sea surface temperature minus surface dewpoint is less than or equal to 3.0 degrees Celsius.