If you thought Mother Nature seemed to be smiling awfully nicely on Alaska’s urban core last month, you were right:
Anchorage set a record for the warmest September on record and the sixth driest, meteorologist Rick Thoman said today.
If you have the feeling this might be something of a new norm, you are also right – at least on the temperature side.
Weather service records show that the 10-year average temperature for the state’s largest city in September has crept above 50 degrees. It stands at 50.17 – more than one and a half degrees above the long-term norm of 48.6 established over the period 1971 to 2000.
A change that small might not seem like much, but it can cause noticeable and visible shifts like the lack of the snow Alaskan’s know as “termination dust” on the Chugach Range montains above the state’s largest city and a somewhat delayed migration of the waterfowl that go honking and quacking through the region as they flee northern breeding grounds for the comforts of warmer winter climes.
Why leave when the grass is still green, the food still available, and the sun shining? The latter this year was somewhat out of line with 10-year trend, but then again maybe not.
Rain, snow, wet
Precipitation numbers for the past decade are something of a mixed bag. The 10-year average has gone up from the long-term norm of 2.99 inches to 3.19 inches in keeping with global-warming models, most of which predict a northward march of the established coastal climates with Juneau, the state capital, becoming more like Seattle and Anchorage becoming more like Juneau.
But 2015 – an outlier in the data – gives global warming skeptics some ammunition for a debate. It was almost 5 inches above the norm. Remove it from the data set, and the month average participation for the past decade drops to 2.69 inches, which is noticeably below the norm.
Thoman, who retired from the National Weather Service at the end of the month and promptly took a job at the Alaska Center for Climate Assessment and Policy at the University of Alaska Fairbanks (people who think a lot sometimes don’t do well with the idea of retirement) said it’s still too early to tell if any of theses changes are truly significant or just ripples in time.
But there’s no denying warm and dry are nice for those who like something approaching a Lower-48 fall rather than a leap from no-snow season to snow season. As a resident of Fairbnaks, Thoman can hardly forget that only three years ago the Interior city was buried in snow.
“For the second time in less than a week, Fairbanks, Alaska, was blanketed with heavy snow. This time, it was a record-breaker,” the Fairbanks Daily News-Miner reported on Sept. 30, 2015.
“Officially, 11.2 inches of snow blanketed Fairbanks International Airport Tuesday, setting an all-time September daily snow record, previously 7.8 inches on Sep. 13, 1992.”
Thoman said it was about 45 degrees when he left his house to go to work today and by lunch time the temperature was pushing toward 60 at the Fairbanks airport. He expects that will soon end, but it was a glorious September in most of Alaska.
“Not everywhere,” Thoman said, “but especially once again over Southern and Western Alaska. Very warm.
“The warmest September of record for Bethel, Anchorage. The warmest since 1927 for Kodiak. Kotzebue, warmest of record.”
And the North Slope and Central Alaska were all above average, although Thoman noted “parts of the state were very, very wet.”
The direct cause – the weather of the present as opposed to the climate overall – was a build up of high pressure air off the Aleutian Islands in the North Pacific Ocean. That reshaped the flow of weather coming toward Alaska from the west.
Warm air already over the state stayed in place, and the typhoons that hit Hong Kong and Tokyo pushed to the south of Alaska instead of spinning north to bring wind and chilling rain from the North Pacific Ocean slamming into the state’s gut.
That high pressure air is now expected to drift north, Thoman said, with low pressure replacing it in the Bering Sea. Since lows pressure systems spin counter-clockwise, the result is expected to be wetter weather and moisture spinning back into the state’s most populated area in the weeks ahead.
It could happen as soon as this weekend.
One of the Weather Service models sees a building Pacific ridge that could cause a tropial low to shift north.
“This would bring sustained gales into the Gulf and eastern Bering with strong winds along the Alaska Range near Iliamna and new the Barren Islands (off the end of the Kenai Peninsula) on Saturday,” today’s long-term forecast suggested. “With the tropical feed, rainfall would be moderate for interior locations of southwest Alaska and moderate to locally heavy for all of Southcentral minus the Copper River basin.
Time to dig out that rain gear that started gathering dust this month.