Space Weather Alerts

Space Weather Message Code: WARK07
Serial Number: 139
Issue Time: 2025 Dec 03 2027 UTC

WARNING: Geomagnetic K-index of 7 or greater expected
Valid From: 2025 Dec 03 2025 UTC
Valid To: 2025 Dec 03 2359 UTC
Warning Condition: Onset
NOAA Scale: G3 or greater

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

Potential Impacts: Area of impact primarily poleward of 50 degrees Geomagnetic Latitude.
Induced Currents - Power system voltage irregularities possible, false alarms may be triggered on some protection devices.
Spacecraft - Systems may experience surface charging; increased drag on low Earth-orbit satellites and orientation problems may occur.
Navigation - Intermittent satellite navigation (GPS) problems, including loss-of-lock and increased range error may occur.
Radio - HF (high frequency) radio may be intermittent.
Aurora - Aurora may be seen as low as Pennsylvania to Iowa to Oregon.

Space Weather Message Code: ALTK06
Serial Number: 677
Issue Time: 2025 Dec 03 1958 UTC

ALERT: Geomagnetic K-index of 6
 Threshold Reached: 2025 Dec 03 1959 UTC
Synoptic Period: 1800-2100 UTC
 
Active Warning: Yes
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: WARK06
Serial Number: 627
Issue Time: 2025 Dec 03 1953 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2025 Dec 03 1952 UTC
Valid To: 2025 Dec 03 2359 UTC
Warning Condition: Onset
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: 1921
Issue Time: 2025 Dec 03 1941 UTC

ALERT: Geomagnetic K-index of 5
 Threshold Reached: 2025 Dec 03 1941 UTC
Synoptic Period: 1800-2100 UTC
 
Active Warning: Yes
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: 1920
Issue Time: 2025 Dec 03 1452 UTC

ALERT: Geomagnetic K-index of 5
 Threshold Reached: 2025 Dec 03 1443 UTC
Synoptic Period: 1200-1500 UTC
 
Active Warning: Yes
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: WARK05
Serial Number: 2145
Issue Time: 2025 Dec 03 1425 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2025 Dec 03 1425 UTC
Valid To: 2025 Dec 04 0000 UTC
Warning Condition: Onset
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: ALTK04
Serial Number: 2612
Issue Time: 2025 Dec 03 1423 UTC

ALERT: Geomagnetic K-index of 4
 Threshold Reached: 2025 Dec 03 1419 UTC
Synoptic Period: 1200-1500 UTC
 
Active Warning: Yes

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: WARK04
Serial Number: 5171
Issue Time: 2025 Dec 03 1022 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 Dec 03 1022 UTC
Valid To: 2025 Dec 03 2359 UTC
Warning Condition: Onset

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: ALTEF3
Serial Number: 3570
Issue Time: 2025 Dec 03 0706 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3569
Begin Time: 2025 Nov 25 1450 UTC
Yesterday Maximum 2MeV Flux: 8535 pfu



Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

Space Weather Message Code: ALTEF3
Serial Number: 3569
Issue Time: 2025 Dec 02 0501 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3568
Begin Time: 2025 Nov 25 1450 UTC
Yesterday Maximum 2MeV Flux: 8521 pfu



Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

Space Weather Message Code: WATA30
Serial Number: 262
Issue Time: 2025 Dec 01 2119 UTC

WATCH: Geomagnetic Storm Category G2 Predicted

Highest Storm Level Predicted by Day:
Dec 02:  None (Below G1)   Dec 03:  G2 (Moderate)   Dec 04:  G2 (Moderate)

THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT

Comment: There is a chance geomagnetic storming could reach G3 (Moderate) levels late 03 Dec, into early 04 Dec.  

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.