Space Weather

Space Weather Message Code: WARK04
Serial Number: 5392
Issue Time: 2026 Jul 24 0856 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 5391
Valid From: 2026 Jul 23 1432 UTC
Now Valid Until: 2026 Jul 24 1500 UTC
Warning Condition: Persistence


NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Space Weather Message Code: WARK05
Serial Number: 2252
Issue Time: 2026 Jul 23 2347 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2251
Valid From: 2026 Jul 23 1619 UTC
Now Valid Until: 2026 Jul 24 0600 UTC
Warning Condition: Persistence


NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

Space Weather Message Code: ALTK05
Serial Number: 2041
Issue Time: 2026 Jul 23 2015 UTC

ALERT: Geomagnetic K-index of 5 
Threshold Reached: 2026 Jul 23 2007 UTC
Synoptic Period: 1800-2100
Active Warning: YES
Noaa Scale: G1 - Minor
Comment: 

NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

Space Weather Message Code: WARK06
Serial Number: 667
Issue Time: 2026 Jul 23 1640 UTC

WARNING: Geomagnetic K-index of 6 expected 
Valid From: 2026 Jul 23 1639 UTC
Valid To: 2026 Jul 23 2359 UTC
Warning Conditions: Onset
Noaa Scale: G2 - Moderate
Comment: 

NOAA Scale: G2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude.
Induced Currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms.
Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
Radio - HF (high frequency) radio propagation can fade at higher latitudes.
Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state.

Space Weather Message Code: ALTK05
Serial Number: 2040
Issue Time: 2026 Jul 23 1621 UTC

ALERT: Geomagnetic K-index of 5 
Threshold Reached: 2026 Jul 23 1621 UTC
Synoptic Period: 1500-1800
Active Warning: YES
Noaa Scale: G1 - Minor
Comment: 

NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.