WSPR spot totals during an X-class solar flare

An X1.5 solar flare on July 3rd, 2021 at 14:29Z which affected most of NA, EU, SA, and AF reduced spot counts by 80-90% in the minutes following the event. Spots counts had returned to normal about 20 minutes later. This resulted in a 15-20% drop in the hourly totals.

I was monitoring 5 bands (40m,30m,20m,17m,10m) and reporting about 25 spots per 2-minute cycle. Following the flare at 14:29Z, I had only 3 spots to report for the 14:28Z cycle, and NO spots for the next 6 minutes at 14:30Z, 14:32Z, and 14:34Z. I only reported 4 spots at 14:36Z and 14:38Z. By 14:40Z spot counts recovered by about 75% and were back to normal around 14:50Z.

Below is a list of the spot totals for each 2-minute cycle covering the time from 10 minutes before until 20 minutes after the solar flare.


Time(Z) Spots
------- -----
14:20 - 4537
14:22 - 4723
14:24 - 4485
14:26 - 3600
14:28 - 849 (Flare at 14:29)
14:30 - 467
14:32 - 856
14:34 - 1144
14:36 - 1492
14:38 - 2000
14:40 - 2871
14:42 - 3019
14:44 - 2936
14:46 - 3394
14:48 - 3975
14:50 - 4670

Mark - KB9AMG