The "frontal-passage" season will stay with us through mid-May then the Bermuda High settles in advancing more Gulf moisture and our traditional steamy weather. The  traditional north to northwest winds that accompany a frontal passage send "whiffs" to us that are either pleasant or offensive. The paper  mills in the Felicianas eject a smell that reminds me of the Heinz plants in Pittsburgh. Tomatoes on your stove that aren't watched become scorched and that smell is similar to the ketchup processing. Flowers Baking Company on Florida Blvd. sends  an aroma that reminds me of Mom's kitchen, freshly baked bread is a nosy treat. A south wind advances the odor from the treatment plant near River Road. In Irwindale, CA.  Huy Fong Foods manufacture Sriracha, a spicy Asian hot sauce. The production of the sauce can release a variety of odors from garlic,  peppers and vinegar. Some residents don't like it, others don't mind it. Environmental scientists have been monitoring the odors at numerous locations . A good wind can move the "smell" or provide the aroma.