Monday, October 31, 2011

Coldest of the Season so Far


A cool airmass is in place over much of the Interior Alaska this Halloween morning. Over a small portion of the western Interior, skies cleared overnight, allowing temperatures to fall to the lowest levels of the early inter season. Here is the NOAA-19 Polar Orbiter infrared satellite photo from about 630am Monday. The clear skies in portions of the Middle Yukon, Koyukuk and Kobuk valleys stand out in this scale as the bright white colors and hints of the dendritic pattern that shows the cold air pooled in valley. Farther east, warmer (darker) and more uniform areas show a nearly continuous stratocumulus cloud cover. Though 10am, low temperatures include 18 below at Huslia, 17 below at the Selawik River RAWS (well upriver of the village of Selawik) and 11 below at Kaltag.
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4 comments:

  1. TroyNovember 1, 2011 at 1:29 PM

    Rick,
    Why is Fairbanks colder than average in the upcoming week. Thanks

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  2. TroyNovember 1, 2011 at 1:32 PM

    Also, why is Yellowknife so warm at this time of the year. yellowknife, on average, is 20 degrees colder than Fairbanks from Nov. to March

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  3. TroyNovember 1, 2011 at 1:37 PM

    interesting model showing the pile up of cold air in the northern Interior (purple shade).
    http://www.wunderground.com/maps/us/alaska/2xFronts.html

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  4. RickNovember 1, 2011 at 7:43 PM

    Hi Trung,

    Normals for Yellowknife are here:

    http://climate.weatheroffice.gc.ca/climate_normals/results_e.html?stnID=1706&lang=e&dCode=1&province=NWT&provBut=Search&month1=0&month2=12

    So average temperatures in Fairbanks are colder in October and November (mostly due to the moderating influence of the gradually freezing Great Slave Lake), and then 4 to 6ºC colder later in the winter.

    Yellowknife is presently mild due to the not frozen over lake AND mild southwest flow aloft (partly chinooked off the northern Rockies). The ridge will break down over the southeast NWT late this week. The extent to which Fairbanks will be below normal will depend on just where the storms moving across the southern Bering Sea track. If any of them is stronger than currently forecast a period of southerly winds aloft could develop and weaken or break the inversion and send temps up above normal.

    Rick

    ReplyDelete