Ce. Dorman et al., SEA-SURFACE MIXED-LAYER DURING THE 10-11 JUNE 1991 CALIFORNIA COASTALLY TRAPPED EVENT, Monthly weather review, 126(3), 1998, pp. 600-619
A midlevel, coastally trapped atmospheric event occurred along the Cal
ifornia coast 10-11 June 1994. This feature reversed the surface wind
field along the coast in a northerly phase progression. Along the cent
ral California coast, the winds at the coastal stations reverse before
the corresponding coastal buoy offshore, then followed hours later by
passage of the leading edge of an overcast stratus cloud. The sea sur
face temperature was much colder in the narrow strip along the coast.
The cloud characteristics may be accounted for by a sea surface mixed
layer (SSML) model beginning with the wind reversal and growing with t
he square root of time. Heat is lost from the SSML to the sea surface.
A cloud forms when the air temperature at the top of the SSML is equa
l to the dewpoint. It is suggested that a bore develops on the top of
the SSML, increasing the thickness of the SSML and the progression spe
ed of the cloud to 8 m s(-1). There is evidence that an undular bore w
ith a leading cloud develops in the thinner inshore SSML. Advancing be
yond Monterey Bay, horizontal density contrast is believed to have cau
sed the bore to change character to a gravity current with a narrower
cloud that passed a. point inshore before the winds reversed at the bu
oys. The last trace of a disturbed boundary layer ended at Point Arena
where strong northerly winds prevented any further northerly progress
ion and contributed to a cyclonic eddy that was formed in the lee of t
he point. Caution is suggested in the interpretation of stratus cloud
phase progression without coastal wind measurements.