August 16, 2012 | Vol. 39, No. 33

2012 records cooler and wetter weather

According to the National Oceanic and Atmospheric Administration, NOAA, Alaskan temperatures have been cooler and wetter than average for the first six months of the year.

The entire state has had its 15th coolest January to June on record with temperatures 3.2 degrees below average.

The Alaska Climate Research Center notes that May in the Southeast Region had a temperature 3.9 degrees below the long-term mean and monthly precipitation was high with 19.25 inches, more than doubling the long term mean of 8.20 inches. It rained 29 of the 31 days of the month and May 2012 was the 4th wettest May on record.

June recorded an average temperature of 51.7 degrees, 2.9 degrees below the long term mean. Precipitation totaled 6.69 inches, just more than double the normal of 3.24 inches and it rained 28 of the 30 days of the month.

Average temperatures for July have come in at 54.9 degrees which is 2 degrees below the long term mean. The coolest day occurred on the 12th of the month and was recorded at 38 degrees which breaks the previous record of 40 degrees set back in 1946.

July precipitation was higher than normal, reporting just over nine inches, or 138 percent of the long term mean amount of 6.57 inches, breaking a record set in 1984.

Monthly weather summaries by the Alaska Climate Research Center state that nearly universally below normal temperatures developed across most of Alaska for July. Given the persistently low temperatures, it is not surprising that there was a large number of new daily record low temperatures set or tied. The low records were set throughout the month, from across Southeast to the Southwest.

There were a fair number of precipitation records set in July as well. The Southeast region alone recorded 117 percent above normal.

In an interview for Our Amazing Planet, Meteorologist Christopher Cox stated that there are several atmospheric forces coming together to create Alaska's cooler weather.

“A climate pattern known as the Pacific Decadal Oscillation is under way, which tends to keep Alaska cooler than normal,” Cox said.

Fisheries scientist Steven Hare of the Joint Institute for the Study of the Atmosphere and Oceans coined the term Pacific Decadal Oscillation in 1996 while researching connections between Alaska salmon production cycles and Pacific climate. PDO has since been described as a long-lived El Nino-like pattern of Pacific climate variability because the two climate oscillations have similar spatial climate fingerprints but very different temporal behavior. The PDO waxes and wanes approximately every 20 to 30 years.

This anomaly affects the climate by way of changes in location of the cold and warm water masses altering the path of the jet stream.

These patterns have continued throughout this summer season but according to The Farmer's Almanac, the Southeast portion of Alaska will see a milder winter for 2012.

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