Monday, March 2, 2015

Kaktovik Wind

The severe blizzard that affected the eastern North Slope on Saturday night was notable for its ferocity in the Barter Island community of Kaktovik, as documented in a news article here.  The highest sustained wind measured at the Barter Island ASOS was 49 knots (56 mph), and the highest gust was 58 knots (67 mph), but the anemometer did not report for several hours during the height of the storm.  It seems very likely that winds were significantly stronger for a time.

How does this storm compare to past high wind events on Barter Island?  The history of hourly observations contains quite a number of bogus wind reports in recent years, but after removing these I found that there have been 18 separate dates (in 13 separate winters) since 1950 on which sustained wind speeds reached 60 knots (69 mph).  All but one of these occurred in November through March.  Without question, Barter Island is a very windy place in winter, and near-hurricane force winds are not all that uncommon.  The top three wind events since 1950 are as follows:

January 6, 1974    70 kt sustained
December 27, 1951    69 kt sustained
September 20, 1957    68 kt sustained

It's interesting to note that most of the 60+ knot events were in the 1950's and 60's, and there do not appear to be any reliable reports of 60 kt or higher since 1995.  This could be due to different wind speed measurement parameters with the introduction of ASOS - but it is surprising nonetheless.

The highest winds at Barter Island are nearly always from a westerly direction, as in this weekend's storm.  The climatological distribution of wind speed also shows a pronounced maximum for east-southeasterly flow (see below), but easterly flow does not bring the same extremes in wind speed.  Winds from the north and south are typically light and are also much less frequent.


8 comments:

  1. Pictures from Kaktovik:

    http://www.ktuu.com/news/news/as-kaktovik-recovers-from-roaring-blizard-a-second-storm-approaches/31574924

    Any downwind portion of the structures typically gets buried, whereas upwind facing walls are subject to snow seepage through cracks, especially around doors. Sidewalls generally stay clean.

    Gary

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  2. There was a blizzard around 9-12 January 2005 that sounds worse than this one...longer anyway. Villigers were without power for days and winds were quoted in news articles as 70 kts (they never say sustained or gust). two story high drifts. No obs for the period in the IEM database! MAybe someone knows hot to dig them up if they exist.
    see
    http://www.cnn.com/2005/WEATHER/01/11/alaska.power.out/index.html
    http://www.cnn.com/2005/WEATHER/01/12/alaska.kaktovik/index.html

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    Replies
    1. The NCDC's hourly observation database is missing those three days. In the adn.com story the other day, a local resident said this year's blizzard was the worst they had ever seen. Of course memories are often not very reliable.

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    2. Good find, Jim! It's an interesting read - indeed 70 knot winds are rare as the mayor said. It's too bad the obs are missing - I doubt they are recoverable as the NCDC archive has a gap from 0715Z on the 9th to 0035Z on the 13th.

      It does make me wonder if there are other events not recorded because the anemometer broke, power went out, or some other reason - as in the event on Saturday and in 2005. Could explain the lack of extreme winds in the ASOS era?

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    3. This is starting to sound like something a weather historian might be interested in figuring out. Was 2005 worse? We have a few weather stations "surrounding" Kaktovik, reanalysis, computer models, newspaper articles, local folklore, and a few days of missing data. I think it would be interesting to see if it's possible that 2005 is really worse just because we can.

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    4. This is starting to sound like something a weather historian might be interested in figuring out. Was 2005 worse? We have a few weather stations "surrounding" Kaktovik, reanalysis, computer models, newspaper articles, local folklore, and a few days of missing data. I think it would be interesting to see if it's possible that 2005 is really worse just because we can.

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    5. Unless the wind obs unit is powered with a UPS or battery it's down if the local AC goes away. Too much to run an ASOS off batteries like the NPS remote units I suppose. Windmills may not survive in that environment and solar in winter???

      Plus, it'd take a sturdy anemometer like one of these: http://www.youngusa.com/products/7/68.html as Ken may have discovered. I need to contact him and see if Howard Pass has been approved for an upgraded unit next winter.

      Gary

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