Cloud rising remarkably fast above a distant grass fire. The same cloud after 15 minutes covered almost half the sky.
Pyrocumulus spreading over head.
Towering cumulus seeded by an agricultural fire fraying to cirrus above and swept slowly over the city by the gentle prevailing wind.
Farmers burn rice straw and now sugar cane fields. These plumes are more common that they were 20 years ago before biodiesel. This one led to general overcast and eventually a local rain storm.