Tuesday, March 31, 2015

Cooling-off period?

Pacific cools; hurricane anxiety doesn't.

Cooling-off period?

The latest developments in the Pacific may be ominous ones for residents and property owners along the Gulf and Atlantic Coasts.

Conditions now are "favorable" for a La Nina cooling event to take hold in the tropical Pacific in time for the bulk of the hurricane season, the government's Climate Prediction Center said in its weekly update today.

It said that while officially the tropical Pacific is in a "neutral" state, the surface waters continue to cool.

Whether the cooling continues could well be a multi-billion-dollar question.

In 2009, the Atlantic Basin had a remarkably quiet hurricane season, and the consensus among the experts is that the El Nino warming was a huge, huge factor. It also was a quiet season for federal disaster expenditures.

During El Nino, when the Pacific waters warm anomalously, the ocean-atmosphere interaction generates powerful upper-air west-to-east winds that can shear off storms trying to build into hurricanes in the Atlantic.

In neutral years, the shear isn't as significant. During La Nina, it is negligible.  In 1997, when La Nina coincided with the season, only three hurricanes formed in the Basin. The following year, when El Nino took hold, the number jumped to 10.





Tony Wood Inquirer Weather Columnist
About this blog

Everyone talks about the weather, and here we write about it.

When we’re around and conditions warrant, we’ll keep you updated about what’s coming, but we will do our best always to discuss weather and climate developments in context and remind you that nothing in the atmosphere happens in a vacuum.

Tony Wood has been writing about the atmosphere for The Inquirer for 26 years.

Reach Tony at twood@phillynews.com.

Tony Wood Inquirer Weather Columnist
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