Sunday, September 14, 2014

Summer in September


The scene at the Golden Heart Plaza is simply glorious:


  1. Saw a 79°F at a the CWOP station at the ABR, Inc. office on Goldstream Road.

  2. Pretty crazy that for a while, Denver was colder than Barrow!
    Meanwhile in Nunavut (Alert and Resolute) the temperature is in the 20's. Also, I recently queried Wolfram-Alpha, and got this result:

    Its pretty remarkable that the temperature difference on annual scale is that extreme for two stations that are only different in latitude by about 2 degrees. Is the blocking effect of the Alaska Range/Canadian Rockies responsible for this difference?

    1. There's probably better visuals and models, but fuss with the various parameters in this forecast time series. Note the cold apparently contained NE of the mountain range as you suggest:


    2. Hi,

      I would say yes - the Rocky Mountain chain is partially responsible for this. The effect of the mountains is to favor a large-scale ridge over western North America and a large-scale semi-permanent trough feature to the east. In winter the cyclonic circulation aloft over Canada is popularly referred to as the polar vortex. On average then we see more southwesterly flow up into Alaska, even as far north as Barrow, and more northwesterly flow over northeastern Canada.

      I suggest another important factor for Barrow is the relative proximity of open water year-round in the North Pacific, i.e. southwest of Barrow. It's not too hard to get warm air up into northern Alaska, but maritime air of a southerly origin has to follow a more tortuous path to Resolute.

    3. Thanks for the response! That helps to clear things up a lot

  3. Indian Summer. That's what we called it where I grew up in New Hampshire. Perhaps Alaska has its own take on the phenomenon of late season warmth?