| TYPE | RADIO BLACKOUT | SOLAR STORM | GEO STORM |
|---|---|---|---|
| SCALE | 1-2: 5%, 3-5: 25% | 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: 5%, 3-5: 5% | 1% | 0 |
| TEXT | None | S1 or < | none |
:Product: 3-Day Forecast
:Issued: 2025 Jul 29 0030 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 Jul 29-Jul 31 2025 is 4.00 (below NOAA
Scale levels).
NOAA Kp index breakdown Jul 29-Jul 31 2025
Jul 29 Jul 30 Jul 31
00-03UT 1.67 2.00 3.67
03-06UT 1.00 1.67 3.00
06-09UT 1.00 2.33 2.67
09-12UT 1.33 2.00 2.00
12-15UT 2.00 2.00 2.33
15-18UT 2.33 2.67 2.33
18-21UT 3.00 3.67 2.67
21-00UT 2.67 4.00 2.67
Rationale: No G1 (Minor) or greater geomagnetic storms are expected. No
significant transient or recurrent solar wind features are forecast.
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 Jul 29-Jul 31 2025
Jul 29 Jul 30 Jul 31
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 Jul 29-Jul 31 2025
Jul 29 Jul 30 Jul 31
R1-R2 25% 30% 30%
R3 or greater 5% 5% 5%
Rationale: Solar activity is likely to be low with a chance for M-class
flares (R1-R2/Minor-Moderate) through 31 July.
Updated last 2025/07/29 06:50 UTC
-------------------
Product ID: EF3A
Issued: 2025-07-28 08:46:56.263
Message Follows:
Space Weather Message Code: ALTEF3
Serial Number: 3507
Issue Time: 2025 Jul 28 0846 UTC
CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3506
Begin Time: 2025 Jul 24 1320 UTC
Yesterday Maximum 2MeV Flux: 1686 pfu
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.
-------------------
Product ID: EF3A
Issued: 2025-07-27 12:52:06.943
Message Follows:
Space Weather Message Code: ALTEF3
Serial Number: 3506
Issue Time: 2025 Jul 27 1252 UTC
CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3505
Begin Time: 2025 Jul 24 1320 UTC
Yesterday Maximum 2MeV Flux: 2510 pfu
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.
-------------------
Product ID: K04A
Issued: 2025-07-26 17:53:56.253
Message Follows:
Space Weather Message Code: ALTK04
Serial Number: 2582
Issue Time: 2025 Jul 26 1753 UTC
ALERT: Geomagnetic K-index of 4
Threshold Reached: 2025 Jul 26 1750 UTC
Synoptic Period: 1500-1800 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: 2025-07-26 17:30:56.627
Message Follows:
Space Weather Message Code: WARK04
Serial Number: 5048
Issue Time: 2025 Jul 26 1730 UTC
WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 Jul 26 1730 UTC
Valid To: 2025 Jul 27 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.
-------------------
Product ID: EF3A
Issued: 2025-07-26 06:01:52.313
Message Follows:
Space Weather Message Code: ALTEF3
Serial Number: 3505
Issue Time: 2025 Jul 26 0601 UTC
CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3504
Begin Time: 2025 Jul 24 1320 UTC
Yesterday Maximum 2MeV Flux: 3124 pfu
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.
-------------------
Product ID: EF3A
Issued: 2025-07-25 10:05:01.873
Message Follows:
Space Weather Message Code: ALTEF3
Serial Number: 3504
Issue Time: 2025 Jul 25 1005 UTC
CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3503
Begin Time: 2025 Jul 24 1320 UTC
Yesterday Maximum 2MeV Flux: 2312 pfu
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.
-------------------
Product ID: A20F
Issued: 2025-07-24 19:47:03.713
Message Follows:
Space Weather Message Code: WATA20
Serial Number: 1054
Issue Time: 2025 Jul 24 1947 UTC
WATCH: Geomagnetic Storm Category G1 Predicted
Highest Storm Level Predicted by Day:
Jul 25: None (Below G1) Jul 26: None (Below G1) Jul 27: G1 (Minor)
THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT
Comment: G1 (Minor) geomagnetic storming is likely on 27 July due to CME effects from an event that left the Sun on 23 July.
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: 2025-07-24 17:47:55.767
Message Follows:
Space Weather Message Code: WARK04
Serial Number: 5047
Issue Time: 2025 Jul 24 1747 UTC
EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 5046
Valid From: 2025 Jul 24 1038 UTC
Now Valid Until: 2025 Jul 25 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.
-------------------
Product ID: EF3A
Issued: 2025-07-24 13:34:35.353
Message Follows:
Space Weather Message Code: ALTEF3
Serial Number: 3503
Issue Time: 2025 Jul 24 1334 UTC
ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Threshold Reached: 2025 Jul 24 1320 UTC
Station: GOES19
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.
-------------------
Product ID: K04A
Issued: 2025-07-24 11:51:45.693
Message Follows:
Space Weather Message Code: ALTK04
Serial Number: 2581
Issue Time: 2025 Jul 24 1151 UTC
ALERT: Geomagnetic K-index of 4
Threshold Reached: 2025 Jul 24 1144 UTC
Synoptic Period: 0900-1200 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: 2025-07-24 10:38:29.880
Message Follows:
Space Weather Message Code: WARK04
Serial Number: 5046
Issue Time: 2025 Jul 24 1038 UTC
WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 Jul 24 1038 UTC
Valid To: 2025 Jul 24 1800 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.
Current 2025 Jul 28 1205 UTC
Solar-terrestrial indices for 27 July follow.
Solar flux 145 and estimated planetary A-index 5.
The estimated planetary K-index at 1200 UTC on 28 July was 1.67.
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 #25-26
2025 July 27 at 7:08 p.m. MDT (2025 July 28 0108 UTC)
**** SPACE WEATHER OUTLOOK ****
Summary For July 21-27
G1 (Minor) geomagnetic storms were observed on 22 - 23 July.
No other significant space weather was observed.
Outlook For July 28-August 3
A chance for R1-R2 (Minor-Moderate) radio blackouts exists on 28 July - 03 August.
No other siginificant space weather is forecasted during the outlook period.