Space Weather Alerts

Space Weather Message Code: WARK04
Serial Number: 5178
Issue Time: 2025 Dec 10 2040 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 Dec 10 2040 UTC
Valid To: 2025 Dec 11 0300 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: WARK04
Serial Number: 5177
Issue Time: 2025 Dec 10 0708 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 Dec 10 0707 UTC
Valid To: 2025 Dec 10 1500 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: WATA50
Serial Number: 95
Issue Time: 2025 Dec 09 2103 UTC

CANCEL WATCH: Geomagnetic Storm Category G3 Predicted
Cancel Serial Number: 94
Original Issue Time: 2025 Dec 07 0443 UTC

Comment: Enhancement from anticipated CME did not occur

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: ALTEF3
Serial Number: 3575
Issue Time: 2025 Dec 09 1210 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3574
Begin Time: 2025 Dec 05 1530 UTC
Yesterday Maximum 2MeV Flux: 1040 pfu



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

Space Weather Message Code: ALTTP4
Serial Number: 699
Issue Time: 2025 Dec 09 0256 UTC

ALERT: Type IV Radio Emission
Begin Time: 2025 Dec 09 0220 UTC



Description: Type IV emissions occur in association with major eruptions on the sun and are typically associated with strong coronal mass ejections and solar radiation storms.

Space Weather Message Code: ALTTP2
Serial Number: 1454
Issue Time: 2025 Dec 09 0215 UTC

ALERT: Type II Radio Emission
Begin Time: 2025 Dec 09 0152 UTC
Estimated Velocity: 759 km/s



Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event.

Space Weather Message Code: ALTTP2
Serial Number: 1453
Issue Time: 2025 Dec 09 0204 UTC

ALERT: Type II Radio Emission
Begin Time: 2025 Dec 09 0141 UTC
Estimated Velocity: 1825 km/s



Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event.

Space Weather Message Code: ALTEF3
Serial Number: 3574
Issue Time: 2025 Dec 08 1237 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3573
Begin Time: 2025 Dec 05 1530 UTC
Yesterday Maximum 2MeV Flux: 1453 pfu



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

Space Weather Message Code: SUMX01
Serial Number: 204
Issue Time: 2025 Dec 08 0513 UTC

SUMMARY: X-ray Event exceeded X1
Begin Time: 2025 Dec 08 0449 UTC
Maximum Time: 2025 Dec 08 0501 UTC
End Time: 2025 Dec 08 0504 UTC
X-ray Class: X1.1
Location: S18W55
NOAA Scale: R3 - Strong

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

Potential Impacts: Area of impact consists of large portions of the sunlit side of Earth, strongest at the sub-solar point.
Radio - Wide area blackout of HF (high frequency) radio communication for about an hour.

Space Weather Message Code: ALTXMF
Serial Number: 505
Issue Time: 2025 Dec 08 0502 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2025 Dec 08 0500 UTC
NOAA Scale: R2 - Moderate

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

Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.

Space Weather Message Code: ALTTP2
Serial Number: 1452
Issue Time: 2025 Dec 08 0046 UTC

ALERT: Type II Radio Emission
Begin Time: 2025 Dec 08 0017 UTC
Estimated Velocity: 317 km/s



Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event.

Space Weather Message Code: ALTEF3
Serial Number: 3573
Issue Time: 2025 Dec 07 2139 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3572
Begin Time: 2025 Dec 05 1530 UTC
Yesterday Maximum 2MeV Flux: 2135 pfu



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