November 2017 http://www.yachtingmonthly.com 25SolvaYacht’s trackSt David’s Head
Ramsey I.South
Bishop0 5nmSTIFF WINDFEEBLE WINDWind changes during passage
through Ramsey SoundDiagram 7WeymouthYacht’s trackChesilBank Portland
HarbourIsle of
PortlandPortland
Bill0 3nmSTIFF
WINDCALMFEEBLE
WINDStronger wind observed on
the lee side of PortlandDiagram 8Vertical sections through air layers, showing contrasting effects observed over
low Portland Harbour and the higher Isle of PortlandWarm airWarm air Wind at
surfaceCool air Calm at surfaceCool airDiagram 915Sea breezes are common in this location
but the new wind was clearly not a sea
breeze, because that would normally start
by blowing across the harbour at low
level. I believe the explanation is that the
new SW wind was plunging down over
the higher Isle of Portland while cooler
air maintained a temperature inversion
over the lower-lying Portland Harbour
(Diagram 9).
14EXPERT ON BOARD
Ramsey Sound:
hazy air, with a
light breeze