Thursday, December 2, 2021

Cold November in the Books

What a month November was, with amazingly persistent cold over western and southwestern areas after the first week of the month.  As expected, it was easily the coldest November on record at King Salmon.



Rick Thoman's November temperature map (below) shows the depth of the cold anomalies - over 20°F below the 1991-2020 normal in spots - but also illustrates that not all of the state was affected: it was warmer than normal in some locations!


Given that cold was not universal, it's remarkable to see that UAF's statewide temperature index stayed below -8.0 for 17 consecutive days (see below).  A value of -8.0 corresponds to the 10th percentile of the 1991-2020 distribution for the time of year, so the state as a whole was colder than the 10th percentile for 17 straight days.  Read more on the UAF index here.  Interestingly the index reveals that the cold back in September - although much less dramatic in absolute terms - was comparable in statistical significance on the days when it occurred, although it didn't last all that long.


Cold continues today, with another -28°F at King Salmon (only two other years have ever been this cold so early in the winter), and -30°F at Unalakleet (and they saw -33°F on Sunday morning).

Also, it's worth noting Alaska's first -50°F of the winter at Toolik Lake on Tuesday morning.

4 comments:

  1. I ran the temperature graph that the National Weather Service offers online for Anchorage for the month of November. What stood out to me was how many days, during the full 24-hr period, never once did the temperature fall within the normal temperature range (43.3%). While Anchorage didn't break any low cold temperature records, they sure have had a sustained cold spell for this early in the season.

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    1. Yes, the persistence of the cold has been very impressive. The pattern has really been locked in.

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  2. Cold winter coming or Alaska. Not much more to say. Look at any model that projects surface to high altitudes and confirm. Not sure why but here it comes.

    Gary

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    1. We in Interior Alaska may get a temp break around the 20th of December. Prior and post that interval low polar cap heights and a dipole of cold is forecast over northern North America. And into the new year? Why not expect more of the same? Prepare.

      Gary

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