Saturday, July 26, 2014
Inquirer Daily News

Drought? This is a record wet period

The great dry-out continues, but it's been an amazingly wet era.

Drought? This is a record wet period

We've mentioned that Philadelphia and rest of the Northeast is fortuitously situated to receive maximum feasible benefit from nature's sprinkler system.

On average, officially Philadelphia receives about 41 inches or rain annually -- and we still have a good shot at reaching that total this year, at 30-plus inches and counting, albeit ever-so slowly.

In the 137 years of record-keeping, only 25 times has the city failed to get less than at least 85 percent of that total, or 35 inches.

What is remarkable about the last seven years is that nature has been turning on the faucet with unprecedented generosity.

Precipitation has averaged 46 inches in the seven-year period that ended Dec. 31 -- or 27 feet of wet stuff. That's  the wettest seven years ever.

The nearest rival would be the seven years ending Dec. 31, 1983, which includes the quite-wet late '70s.

By contrast, at the turn of the last century an average of only 35.4 inches fell from 1890 through 1896, the driest such period. In second place would be 1959 through 1965, coinciding with one of the worst drought periods ever.

One hypothesis for why it has been so wet is the general worldwide warming which theoretically would introduce more water vapor into the atmosphere.

Whether that's the case, it is clear from the period of record that precipitation has been subject to dramatic decadal cycles.

What is also clear is that despite this impressive dry spell, the groundwater and reservoir supplies remain in decent shape for a reason: For seven years, we've been swamped.

 

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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