Sunday, June 1, 2014

Lightning Season Begins

Right on cue, the lightning season has begun in Alaska. Yesterday was the first day that the BLM's lightning detection network recorded more than 10 cloud-to-ground strikes in a day. A total of 198 strikes were recorded on Saturday (5/31).

Figure 1 shows the location of yesterday's cloud-to-ground lightning strikes. All of the strike were between Galena and Eagle and were all north of the Alaska Range. I did not see any thunderstorm reports from a quick look at the METARs but my search was not exhaustive.

Figure 2 shows and a frequency distribution chart of total strikes in Alaska by 10-day interval between 1986 and 2012. ‪It is similar to the charts from last weeks post on thunderstorm and lightning climatology. Since a new lightning detection system was implemented in 2013, the raw values shown in Figure 2 may not be representative any more. However, the temporal pattern is still valid.

Figure 1. All cloud-to-ground lightning strikes in Alaska on May 31, 2014.

Figure 2. Lighting frequency during 10-day periods for all Alaska between 1986 and 2012. (Note: July 31 and August 31 were omitted to keep the interval size consistent.)



    Watch this proposed event as a source of lightning over Interior and Northern Alaska.