Weather Alert

May 10, 2024 Weather Alert

NATIONAL ISSUED “SEVERE (G4) GEOMAGNETIC STORM WATCH”  05102024.0077

  • A Severe (G4) Geomagnetic Storm Watch is in effect. Seven (7) earth-directed Coronal Mass Ejections (CMEs) were observed and expected to arrive as early as later today and persist through the weekend. This is an unusual event.
  • The flares are associated with a large and magnetically complex sunspot cluster (NOAA region 3664), at least 17 times the diameter of Earth. Additional solar activity from this region is expected.
  • Possible widespread voltage control problems and some protective systems will mistakenly trip out key assets from the grid. There may also be impacts to HF/VHF communication, GPS, satellite navigation, and other technologies.
  • Weather permitting, aurora may be visible as far south as Alabama and northern California, though overcast skies appear likely for Central Pennsylvania.
  • Only three Severe geomagnetic storms have been observed during this solar cycle, which began in December 2019. The last G4 (Severe) was a short-lived event on March 23, 2024, and the last G5 (Extreme) occurred with the Halloween Storms in October 2003. That G5 resulted in power outages in Sweden and damaged power transformers in South Africa.  

Wm. Dennis Buttorff
Emergency Manager
West Branch Emergency Management Association, Inc.