Angola
locally heavy rainfall causes periodic flooding on the plateau
Anguilla
frequent hurricanes and other tropical storms (July to
October)
Antarctica
katabatic (gravity-driven) winds blow coastward from the
high interior; frequent blizzards form near the foot of the plateau;
cyclonic storms form over the ocean and move clockwise along the
coast; volcanism on Deception Island and isolated areas of West
Antarctica; other seismic activity rare and weak; large icebergs may
calve from ice shelf
Antigua and Barbuda
hurricanes and tropical storms (July to
October); periodic droughts
Arctic Ocean
ice islands occasionally break away from northern
Ellesmere Island; icebergs calved from glaciers in western Greenland
and extreme northeastern Canada; permafrost in islands; virtually
ice locked from October to June; ships subject to superstructure
icing from October to May
Argentina
San Miguel de Tucuman and Mendoza areas in the Andes
subject to earthquakes; pamperos are violent windstorms that can
strike the Pampas and northeast; heavy flooding
Armenia
occasionally severe earthquakes; droughts
Aruba
lies outside the Caribbean hurricane belt
Ashmore and Cartier Islands
surrounded by shoals and reefs that can
pose maritime hazards
Atlantic Ocean
icebergs common in Davis Strait, Denmark Strait, and
the northwestern Atlantic Ocean from February to August and have
been spotted as far south as Bermuda and the Madeira Islands; ships
subject to superstructure icing in extreme northern Atlantic from
October to May; persistent fog can be a maritime hazard from May to
September; hurricanes (May to December)