Browning Newsletter on Climate, Behavior and Commodities: The Growing La Niña
My thanks to Alex
Seagle of Fraser Asset Management for the latest edition of their fascinating
publication
written by Evelyn Browning Garriss. Here is a brief sample:
The little lady is growing up. La Niña (Spanish for "the girl") is getting colder and stronger. North America is downwind from this Pacific weather phenomenon and it's never wise to get on the wrong side of a lady. We are already getting a preview of how cold and dry this winter will be.
Let's take a moment to go over some official definitions.
La Niña temperatures are when the Tropical Pacific is 0.5°C (0.9°F) cooler than normal. At this point, the temperatures start to alter ocean and air currents that affect tropical weather. The cooler Pacific has been affecting global weather since late May.
Officially a La Niña condition is when a central portion of the tropical Pacific is 0.5°C (0.9°F) below normal for three months running. We are currently experiencing La Niña conditions.
A La Niña episode is when the tropical Pacific has had "5 consecutive overlapping 3-month seasons" with temperatures 0.5°C (0.9°F) below normal. Historically what we are experiencing now will not be considered an official La Niña unless it lasts through November.
The Cooling Pacific
The Tropical Pacific has been cooling since last March. By May, the ocean was showing La Niña conditions, with tropical temperatures 0.5°C (0.9°F) lower than normal. The phenomenon was officially declared a La Niña condition two months later.
Technically we are only going through a condition. Historically, however, even a condition can really mess up North American weather. If it occurs in autumn, it strengthens the Atlantic Hurricane Season. If it occurs in winter, it brings cold weather to the north and drought to the South. If it occurs in spring, it brings droughts and flooding throughout most of America's croplands.
Recent models suggest that we will be experiencing a complete La Niña episode, with cool conditions lingering in the Tropical Pacific until next April or May.
David Fuller's view If you want to know more about why global weather remains so turbulent, and how this may further affect agricultural crops, Evelyn Browning Garriss is a leading climatologist.
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