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Geomagnetic activity forecasts

Updated 4 times since CLSTR started tracking revisions of this situation.

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2026-10-23 06:22 UTC → 2026-10-25 16:35 UTC · added removed

In late September 2026, the NOAA Space Weather Prediction Center forecasted moderate geomagnetic activity. For September 26, the maximum expected three-hour planetary Kp index was 3.67, which was below the threshold for a G1 category geomagnetic storm. While there was a 40% probability of active conditions, official expectations remained below G1 levels. By mid-October 2026, NOAA forecasted increased geomagnetic activity for October 14. The Space Weather Prediction Center expected the planetary Kp index to reach a maximum value of 4. Although this indicated elevated activity, it remained below the Kp 5 threshold required to classify a G1-category weak magnetic storm. Probabilities for that day included a 35% chance of active geomagnetic conditions and a 25% chance of a weak magnetic storm. Peak activity was anticipated between 06:00 and 09:00 UTC. On October 17, NOAA indicated that no geomagnetic storm was forecast for October 18, 2026. The Kp-index was expected to remain at a low level of approximately 1.7, signifying minimal activity. 1.7. However, experts noted the possibility of solar flares, including a 25% probability of R1-R2 category radio disturbances and a 10% chance of more significant R3-R5 category events. disturbances. For the week of October 19–25, 2026, geomagnetic activity is expected to fluctuate. While earlier forecasts suggested Kp levels might reach 4 on several days, a fluctuated. A high-speed solar wind stream from a coronal hole caused a brief G1-category minor geomagnetic storm on October 22, reaching a Kp value of 4.67. Following this event, this, NOAA forecasted calmer conditions for October 23 and 24, with Kp values expected to range between 1.00 and 2.67, remaining well below 2.67. Looking toward the G1-category threshold. end of the month, NOAA and the SWPC issued forecasts for increased activity between October 23 and October 26. On October 25, the Kp index is expected to reach a maximum of 3.67, with peak activity predicted during two windows: 09:00 to 12:00 and 15:00 to 18:00 Bulgarian time. For October 26, activity is expected to remain elevated but at a lower intensity, with Kp predictions ranging from 2 to 2.7.

Versions

  1. 2026-10-25 16:35 UTC Geomagnetic activity forecasts
  2. 2026-10-23 06:22 UTC Geomagnetic activity forecasts
  3. 2026-10-21 06:22 UTC Geomagnetic activity forecasts
  4. 2026-10-17 16:16 UTC Geomagnetic activity forecasts
  5. 2026-10-13 16:05 UTC Geomagnetic activity forecasts

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