Wednesday, June 28, 2017

Arctic Storm - Weaker Than Expected

This is just a quick update to note that the Arctic storm that was advertised last week failed to strengthen as much as the ECMWF forecast suggested.  The minimum central pressure dropped to about 980mb, which is quite low - some years do not produce any storms this strong in the Arctic during summer - but not as low as the model indicated.  For a forecast made only about 3 days ahead, this is not very good, which illustrates that Arctic weather remains difficult to predict.

Here's a sequence of MSLP maps, courtesy of Environment Canada.

3am AKST Saturday June 24:


3pm AKST Sunday June 25:


3pm AKST Monday June 26:


4 comments:

  1. How did they measure the pressure?

    Gary

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    Replies
    1. Buoy sensors, mostly. And the global weather models provide a decent first guess analysis field every 6 or 12 hours.

      http://iabp.apl.washington.edu/maps_daily_map.html

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  2. On the fire service lightning maps for 7/3/17 there is a cluster of detects NE of Kaktovik off the McKenzie Delta. Are those artifacts? Or real? How common are t-storms over the Arctic Ocean?

    See:
    https://afsmaps.blm.gov/imf_lightning/imf.jsp?site=lightning

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    Replies
    1. Very interesting questions - thanks for pointing this out. With one of the sensors being located in Kaktovik, I doubt these are artifacts, and there was a low pressure system in the area yesterday. But I really have no idea how common lightning is over the Arctic Ocean - it would make for an interesting study.

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