Saturday, July 13, 2024

Regional Lightning Data

For my latest data project, I have been looking at the distribution of lightning within Alaska's 21 fire management regions, i.e. the Predictive Service Areas:


Using the 2012-present lightning data from AICC, I've assigned each lightning strike to one of the zones, or to an adjacent region in Canada or over the ocean - I'm still working on the ocean zones.  This will be useful for looking at historical lightning variations by region, and for assessing realtime activity compared to the (modern) historical average.

The greatest density of lightning occurs in the three zones to the north of the Alaska Range, what I'll call the Tanana valley zones (AK01E, AK01W, AK03S).  (There's also a Tanana Zone-North PSA, but that's considerably less active.)  Here's the annual number of ground lightning strikes in these 3 zones, both for the full year and through July 12:


These zones comprise just over 10% of the area of Alaska, but they receive about a third of the lightning strikes in the state.  This year's activity is below normal so far: the 4th lowest in 13 years of data.

Interestingly the last two years were polar opposites in terms of the timing of lightning: in 2022 it was nearly all prior to this date, but last year most of the lightning activity was after July 12.

The region of Alaska with the largest lightning deficit so far this year is the northeast interior, i.e. the large Upper Yukon Valley zone.  This zone is very nearly as large as the 3 Tanana valley zones combined, and it gets the most lightning of any single zone in terms of total number of strikes.  Here's the chart of annual numbers:


As of July 12, the total activity in this zone is above last year, but that will change imminently.  It's interesting to see how active the first half of summer was in 2012-2017 in this zone, whereas since then only 2022 was very active before mid-July.

Now that I have this data set at my disposal, blog readers should brace for a few more posts analyzing the numbers.


2 comments:

  1. Great work. Looking forward to more analysis.
    I seem to remember that past lightning climatologies put the highest density in the Upper Yukon Valley.

    ReplyDelete
  2. Very interesting! I'd like to see a write up on the record setting rain event last week at ANC.

    ReplyDelete