In northern Australia, the sun rises over the Gulf of Carpentaria every day. Sometimes,
however, particularly on spring mornings before dawn, a lone, rolling cloud will stretch
from horizon to horizon, blowing low, fast, and straight across the sky. It is often
accompanied by gusty wind or mist, and then disappears. It is known as the Morning Glory.
This phenomenon does not occur anywhere else in the world, and has long been a puzzle to
scientists. Sometimes as many as seven of these clouds roll across the sky in succession,
each one a few hundred feet thick but seventy-five miles or more in length.
After analyzing air pressure, wind direction, moisture, and the cloud’s passing speed,
Australian researchers think that the mass is formed when dry winds coming off the Cape
York Peninsula meet the gulf’s opposing moist air. They form a swirl, which could produce
the Morning Glory.