| TYPE | RADIO BLACKOUT | SOLAR STORM | GEO STORM |
|---|---|---|---|
| SCALE | 1-2: 1%, 3-5: 20% | 1% | 0 |
| TEXT | None | S1 or < | none |
| TYPE | RADIO BLACKOUT | SOLAR STORM | GEO STORM |
|---|---|---|---|
| SCALE | 0 | 0 | 0 |
| TEXT | none | none | none |
| TYPE | RADIO BLACKOUT | SOLAR STORM | GEO STORM |
|---|---|---|---|
| SCALE | 1-2: 1%, 3-5: 1% | 1% | 0 |
| TEXT | None | S1 or < | none |
:Product: 3-Day Forecast
:Issued: 2025 Sep 13 1230 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
#
A. NOAA Geomagnetic Activity Observation and Forecast
The greatest observed 3 hr Kp over the past 24 hours was 3 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Sep 13-Sep 15 2025 is 4.00 (below NOAA
Scale levels).
NOAA Kp index breakdown Sep 13-Sep 15 2025
Sep 13 Sep 14 Sep 15
00-03UT 1.67 3.00 3.00
03-06UT 2.67 3.67 4.00
06-09UT 2.67 2.67 3.67
09-12UT 2.00 2.67 2.67
12-15UT 2.00 3.67 2.00
15-18UT 2.00 4.00 1.67
18-21UT 2.67 3.67 2.67
21-00UT 3.00 3.00 3.00
Rationale: There is a chance for G1 (Minor) storm periods on 14-15 Sep,
due to negative polarity CH HSS influences.
B. NOAA Solar Radiation Activity Observation and Forecast
Solar radiation, as observed by NOAA GOES-18 over the past 24 hours, was
below S-scale storm level thresholds.
Solar Radiation Storm Forecast for Sep 13-Sep 15 2025
Sep 13 Sep 14 Sep 15
S1 or greater 1% 1% 1%
Rationale: No S1 (Minor) or greater solar radiation storms are expected.
No significant active region activity favorable for radiation storm
production is forecast.
C. NOAA Radio Blackout Activity and Forecast
No radio blackouts were observed over the past 24 hours.
Radio Blackout Forecast for Sep 13-Sep 15 2025
Sep 13 Sep 14 Sep 15
R1-R2 20% 20% 20%
R3 or greater 1% 1% 1%
Rationale: There is a slight chance for isolated R1-R2 (Minor-Moderate)
radio blackouts through 15 Sep.
Updated last 2025/09/13 14:00 UTC
-------------------
Product ID: K04A
Issued: 2025-09-11 02:51:25.523
Message Follows:
Space Weather Message Code: ALTK04
Serial Number: 2590
Issue Time: 2025 Sep 11 0251 UTC
ALERT: Geomagnetic K-index of 4
Threshold Reached: 2025 Sep 11 0244 UTC
Synoptic Period: 0000-0300 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.
-------------------
Product ID: K04W
Issued: 2025-09-11 01:08:35.540
Message Follows:
Space Weather Message Code: WARK04
Serial Number: 5077
Issue Time: 2025 Sep 11 0108 UTC
WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 Sep 11 0108 UTC
Valid To: 2025 Sep 11 0900 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.
-------------------
Product ID: K05W
Issued: 2025-09-10 09:08:50.557
Message Follows:
Space Weather Message Code: WARK05
Serial Number: 2098
Issue Time: 2025 Sep 10 0908 UTC
WARNING: Geomagnetic K-index of 5 expected
Valid From: 2025 Sep 10 0908 UTC
Valid To: 2025 Sep 10 1500 UTC
Warning Condition: Persistence
NOAA Scale: G1 - Minor
Comment: Corrected dates.
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.
-------------------
Product ID: K05W
Issued: 2025-09-10 09:06:34.280
Message Follows:
Space Weather Message Code: WARK05
Serial Number: 2097
Issue Time: 2025 Sep 10 0906 UTC
CANCEL WARNING: Geomagnetic K-index of 5 expected
Cancel Serial Number: 2096
Original Issue Time: 2025 Sep 09 2240 UTC
Comment: Wrong Valid to date. Correction being issued.
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.
-------------------
Product ID: K04W
Issued: 2025-09-10 05:46:22.323
Message Follows:
Space Weather Message Code: WARK04
Serial Number: 5076
Issue Time: 2025 Sep 10 0546 UTC
EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 5075
Valid From: 2025 Sep 09 2100 UTC
Now Valid Until: 2025 Sep 10 1800 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.
-------------------
Product ID: K05W
Issued: 2025-09-10 05:46:22.277
Message Follows:
Space Weather Message Code: WARK05
Serial Number: 2096
Issue Time: 2025 Sep 10 0546 UTC
EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2095
Valid From: 2025 Sep 09 2240 UTC
Now Valid Until: 2025 May 10 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 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.
-------------------
Product ID: K06A
Issued: 2025-09-09 23:28:12.410
Message Follows:
Space Weather Message Code: ALTK06
Serial Number: 653
Issue Time: 2025 Sep 09 2328 UTC
ALERT: Geomagnetic K-index of 6
Threshold Reached: 2025 Sep 09 2316 UTC
Synoptic Period: 2100-2400 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.
-------------------
Product ID: K06W
Issued: 2025-09-09 23:18:46.190
Message Follows:
Space Weather Message Code: WARK06
Serial Number: 602
Issue Time: 2025 Sep 09 2318 UTC
WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2025 Sep 09 2318 UTC
Valid To: 2025 Sep 10 0600 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.
-------------------
Product ID: K05A
Issued: 2025-09-09 23:18:13.280
Message Follows:
Space Weather Message Code: ALTK05
Serial Number: 1847
Issue Time: 2025 Sep 09 2318 UTC
ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 Sep 09 2309 UTC
Synoptic Period: 2100-2400 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.
-------------------
Product ID: K05W
Issued: 2025-09-09 22:40:30.607
Message Follows:
Space Weather Message Code: WARK05
Serial Number: 2095
Issue Time: 2025 Sep 09 2240 UTC
WARNING: Geomagnetic K-index of 5 expected
Valid From: 2025 Sep 09 2240 UTC
Valid To: 2025 Sep 10 0600 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.
-------------------
Product ID: K04A
Issued: 2025-09-09 22:02:08.870
Message Follows:
Space Weather Message Code: ALTK04
Serial Number: 2589
Issue Time: 2025 Sep 09 2202 UTC
ALERT: Geomagnetic K-index of 4
Threshold Reached: 2025 Sep 09 2154 UTC
Synoptic Period: 2100-2400 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.
Current 2025 Sep 13 1205 UTC
Solar-terrestrial indices for 12 September follow.
Solar flux 114 and estimated planetary A-index 8.
The estimated planetary K-index at 1200 UTC on 13 September was 2.00.
No space weather storms were observed for the past 24 hours.
No space weather storms are predicted for the next 24 hours.
Official Space Weather Advisory issued by NOAA Space Weather Prediction Center
Boulder, Colorado, USA
SPACE WEATHER ADVISORY OUTLOOK #25-32
2025 September 7 at 8:30 p.m. MDT (2025 September 8 0230 UTC)
**** SPACE WEATHER OUTLOOK ****
Summary For September 1-7
G2 (Moderate) geomagnetic storm levels were observed on 01 Sep in response to the arrival of a CME that left the Sun on 30 Aug.
G1 (Minor) geomagnetic storm levels were observed on 02 Sep due to waning CME effects.
G1 (Minor) geomagnetic storm levels were observed on 06 Sep in response to the arrival of a CME that left the Sun on 04 Sep.
R1 (Minor) radio blackouts were observed on 04-06 Sep due to activity from Region 4207.
No other space weather storms were observed during the summary period.
Outlook For September 8-14
No space weather storms are currently expected during the outlook period.