Monday, 23 December 2013

Why is the Weather so Stormy?

After the first four gales went through, we've become so used to brisk winds that they're almost becoming normal.  We've hardly had a day recently when the wind has been less than a 'strong breeze', and we've hardly seen the sun - the Diary was so excited by this break in the clouds yesterday, which proved that, somewhere above them, a blue sky still existed, that it rushed out and took a picture.

The rain, sleet, hail and snow, accompanied by occasional lightning, just keep coming - picture shows deer prints after a hailstorm.  The total precipitation over the last month hasn't been exceptional - 205mm, as compared to 146mm for the same period last year.  It's the almost constant parade of high winds which seems unusual.

The NOAA's 'Global Analysis' for November 2013 may offer an explanation.  It includes this map of the Earth's surface which shows the average temperature across global land and ocean surfaces during November 2013.  The NOAA says that the average temperature was, "record highest for November in the 134-year period of record, at 0.78°C (1.40°F) above the 20th century average. This surpasses the previous record set in 2004 by 0.03°C (0.05°F) and is also the sixth highest monthly departure from average among all months on record."

Since our prevailing winds come in from the southwest, across a section of the North Atlantic which is 'warmer' to 'much warmer' than average, it's not surprising that they're damp and, therefore, dumping their dampness on us; and the warm North Atlantic is the obvious source of the energy that been driving them.

Map courtesy NOAA National Climate Data Center - article here.
The NOAA's map featured on the excellent science website, EarthSky

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