| TYPE | RADIO BLACKOUT | SOLAR STORM | GEO STORM |
|---|---|---|---|
| SCALE | 1-2: 15%, 3-5: 70% | 15% | 1 |
| TEXT | None | S1 or < | minor |
| TYPE | RADIO BLACKOUT | SOLAR STORM | GEO STORM |
|---|---|---|---|
| SCALE | 0 | 0 | 1 |
| TEXT | none | none | minor |
| TYPE | RADIO BLACKOUT | SOLAR STORM | GEO STORM |
|---|---|---|---|
| SCALE | 1-2: 15%, 3-5: 15% | 15% | 1 |
| TEXT | None | S1 or < | minor |
:Product: 3-Day Forecast
:Issued: 2025 Apr 04 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 5 (NOAA Scale
G1).
The greatest expected 3 hr Kp for Apr 04-Apr 06 2025 is 5.00 (NOAA Scale
G1).
NOAA Kp index breakdown Apr 04-Apr 06 2025
Apr 04 Apr 05 Apr 06
00-03UT 4.00 5.00 (G1) 2.67
03-06UT 4.00 4.00 3.33
06-09UT 4.00 3.67 2.33
09-12UT 4.00 3.33 2.00
12-15UT 3.67 2.33 2.33
15-18UT 3.00 2.33 2.00
18-21UT 4.67 (G1) 2.67 2.33
21-00UT 2.67 2.67 2.67
Rationale: G1 (Minor) geomagnetic storms are likely on 04-05 Apr due
primarily to coronal hole influence.
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 Apr 04-Apr 06 2025
Apr 04 Apr 05 Apr 06
S1 or greater 15% 15% 15%
Rationale: There is a slight chance for S1 (Minor) solar radiation
storms over 04-06 Apr.
C. NOAA Radio Blackout Activity and Forecast
No radio blackouts were observed over the past 24 hours.
Radio Blackout Forecast for Apr 04-Apr 06 2025
Apr 04 Apr 05 Apr 06
R1-R2 70% 70% 70%
R3 or greater 15% 15% 15%
Rationale: R1-R2 (Minor-Moderate) radio blackouts are likely, with a
slight chance for R3 (Strong), over 04-06 Apr.
Updated last 2025/04/04 13:30 UTC
-------------------
Product ID: K05A
Issued: 2025-04-04 13:07:55.293
Message Follows:
Space Weather Message Code: ALTK05
Serial Number: 1736
Issue Time: 2025 Apr 04 1307 UTC
ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 Apr 04 1307 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.
-------------------
Product ID: K05W
Issued: 2025-04-04 05:49:37.260
Message Follows:
Space Weather Message Code: WARK05
Serial Number: 2008
Issue Time: 2025 Apr 04 0549 UTC
EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2007
Valid From: 2025 Apr 03 1943 UTC
Now Valid Until: 2025 Apr 04 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 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: 2025-04-04 05:48:56.150
Message Follows:
Space Weather Message Code: WARK04
Serial Number: 4902
Issue Time: 2025 Apr 04 0548 UTC
EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4901
Valid From: 2025 Apr 02 0123 UTC
Now Valid Until: 2025 Apr 04 2100 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: K05A
Issued: 2025-04-04 00:01:35.257
Message Follows:
Space Weather Message Code: ALTK05
Serial Number: 1735
Issue Time: 2025 Apr 04 0001 UTC
ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 Apr 03 2359 UTC
Synoptic Period: 2100-0000 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: K05A
Issued: 2025-04-03 20:02:52.830
Message Follows:
Space Weather Message Code: ALTK05
Serial Number: 1734
Issue Time: 2025 Apr 03 2002 UTC
ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 Apr 03 2002 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.
-------------------
Product ID: K05W
Issued: 2025-04-03 19:43:10.753
Message Follows:
Space Weather Message Code: WARK05
Serial Number: 2007
Issue Time: 2025 Apr 03 1943 UTC
WARNING: Geomagnetic K-index of 5 expected
Valid From: 2025 Apr 03 1943 UTC
Valid To: 2025 Apr 04 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: K04W
Issued: 2025-04-03 17:56:36.880
Message Follows:
Space Weather Message Code: WARK04
Serial Number: 4901
Issue Time: 2025 Apr 03 1756 UTC
EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4900
Valid From: 2025 Apr 02 0123 UTC
Now Valid Until: 2025 Apr 04 0600 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: K04W
Issued: 2025-04-03 17:55:29.630
Message Follows:
Space Weather Message Code: WARK04
Serial Number: 4900
Issue Time: 2025 Apr 03 1755 UTC
EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4899
Valid From: 2025 Apr 02 0123 UTC
Now Valid Until: 2025 Apr 03 0600 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: K04W
Issued: 2025-04-03 09:05:19.997
Message Follows:
Space Weather Message Code: WARK04
Serial Number: 4899
Issue Time: 2025 Apr 03 0905 UTC
EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4898
Valid From: 2025 Apr 02 0123 UTC
Now Valid Until: 2025 Apr 03 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: A20F
Issued: 2025-04-02 21:12:53.093
Message Follows:
Space Weather Message Code: WATA20
Serial Number: 1035
Issue Time: 2025 Apr 02 2112 UTC
WATCH: Geomagnetic Storm Category G1 Predicted
Highest Storm Level Predicted by Day:
Apr 03: None (Below G1) Apr 04: G1 (Minor) Apr 05: G1 (Minor)
THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT
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: 2025-04-02 20:59:35.890
Message Follows:
Space Weather Message Code: WARK04
Serial Number: 4898
Issue Time: 2025 Apr 02 2059 UTC
EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4897
Valid From: 2025 Apr 02 0123 UTC
Now Valid Until: 2025 Apr 03 1000 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.
Current 2025 Apr 03 1205 UTC
Solar-terrestrial indices for 02 April follow.
Solar flux 180 and estimated planetary A-index 22.
The estimated planetary K-index at 1200 UTC on 03 April was 3.67.
No space weather storms were observed for the past 24 hours.
Space weather for the next 24 hours is predicted to be minor.
Geomagnetic storms reaching the G1 level are likely.
Radio blackouts reaching the R1 level are expected.
Official Space Weather Advisory issued by NOAA Space Weather Prediction Center
Boulder, Colorado, USA
SPACE WEATHER ADVISORY OUTLOOK #25-11
2025 March 30 at 8:41 p.m. MDT (2025 March 31 0241 UTC)
**** SPACE WEATHER OUTLOOK ****
Summary For March 24-30
R3 (Strong) radio blackouts were observed on 28 Mar due to activity from Region 4046.
R1 (Minor) radio blackouts were observed on 27-30 Mar due to activity Regions 4043, 4046, and 4048.
G2 (Moderate) geomagentic storms were observed on 26 Mar due to influence from a coronal hole.
G1 (Minor) geomagnetic storms were observed on 26-27 Mar due to influence from a coronal hole.
No other space weather storms were observed during the summary period.
Outlook For March 31-April 6
R1-R2 (Minor-Moderate) radio blackouts are likely on 31 Mar primarily due to the potential from Regions 4046 and 4048.
G1 (Minor) geomagnetic storms are likely on 04 Apr due to recurrent coronal hole influence.
G2 (Moderate) geomagnetic storms are likely on 05 Apr due to recurrent coronal influence.
No other space weather storms are expected during the outlook period.
LATITUDE LONGITUDE ALTITUDE VELOCITY
° ° Miles MPH