| TYPE | RADIO BLACKOUT | SOLAR STORM | GEO STORM |
|---|---|---|---|
| SCALE | 1-2: 5%, 3-5: 35% | 75% | 0 |
| TEXT | None | S1 or < | moderate |
| 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% | 75% | 2 |
| TEXT | None | S1 or < | moderate |
:Product: 3-Day Forecast
:Issued: 2026 Aug 01 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 2 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Aug 01-Aug 03 2026 is 5.67 (NOAA Scale
G2).
NOAA Kp index breakdown Aug 01-Aug 03 2026
Aug 01 Aug 02 Aug 03
00-03UT 3.00 4.00 3.33
03-06UT 2.33 4.33 4.00
06-09UT 2.00 5.67 (G2) 3.00
09-12UT 1.33 4.33 2.33
12-15UT 3.00 5.00 (G1) 3.00
15-18UT 3.00 3.00 1.00
18-21UT 3.67 1.67 1.00
21-00UT 4.00 1.67 0.67
Rationale: G1-G2 (Minor-Moderate) geomagnetic storms are likely on 02
Aug due to the anticipated arrival of CME that left the Sun on 30 Jul.
B. NOAA Solar Radiation Activity Observation and Forecast
Solar radiation, as observed by NOAA GOES-18 over the past 24 hours, was
above S-scale storm level thresholds (S1 - Minor level).
Solar Radiation Storm Forecast for Aug 01-Aug 03 2026
Aug 01 Aug 02 Aug 03
S1 or greater 75% 25% 10%
Rationale: S1 (Minor) solar radiation storms are expected on 01 Aug.
There is a chance for S1 (Minor) radiation storms on 02 Aug and a slight
chance on 03 Aug.
C. NOAA Radio Blackout Activity and Forecast
No radio blackouts were observed over the past 24 hours.
Radio Blackout Forecast for Aug 01-Aug 03 2026
Aug 01 Aug 02 Aug 03
R1-R2 35% 35% 35%
R3 or greater 5% 5% 5%
Rationale: There is a chance for R1 (Minor) radio blackouts on 01-03
Aug.
Updated last 2026/08/01 07:45 UTC
-------------------
Product ID: P11W
Issued: 2026-07-31 21:54:42.097
Message Follows:
Space Weather Message Code: WARPX1
Serial Number: 630
Issue Time: 2026 Jul 31 2154 UTC
EXTENDED WARNING: Proton 10MeV Integral Flux above 10pfu expected\nExtension to Serial Number: 629\nValid From: 2026 Jul 31 1335 UTC\nNow Valid Until: 2026 Aug 01 1200 UTC\nWarning Condition: Persistence\n
NOAA Scale: S1 - Minor
-------------------
Product ID: P20S
Issued: 2026-07-31 18:46:01.543
Message Follows:
Space Weather Message Code: SUMPC0
Serial Number: 40
Issue Time: 2026 Jul 31 1846 UTC
SUMMARY: Proton Event 100MeV Integral Flux exceeded 1pfu \nBegin Time: 2026 Jul 30 1825 UTC\nMaximum Time: 2026 Jul 30 1826 UTC\nEnd Time: 2026 Jul 30 1830 UTC\nMaximum 100MeV Flux: 1 pfu\nComment:
-------------------
Product ID: P11A
Issued: 2026-07-31 13:37:05.743
Message Follows:
Space Weather Message Code: ALTPX1
Serial Number: 367
Issue Time: 2026 Jul 31 1337 UTC
ALERT: Proton Event 10meV Integral Flux exceeded 10pfu \nBegin Time: 2026 Jul 31 1336 UTC\nNoaa Scale: S1 - Minor\nComment:
NOAA Scale: S1 - Minor
-------------------
Product ID: P11W
Issued: 2026-07-31 13:36:17.447
Message Follows:
Space Weather Message Code: WARPX1
Serial Number: 629
Issue Time: 2026 Jul 31 1336 UTC
WARNING: Proton 10MeV Integral Flux above 10pfu expected \nValid From: 2026 Jul 31 1335 UTC\nValid To: 2026 Jul 31 2359 UTC\nWarning Conditions: Onset\nNoaa Scale: S1 - Minor\nComment:
NOAA Scale: S1 - Minor
-------------------
Product ID: A30F
Issued: 2026-07-31 11:05:14.830
Message Follows:
Space Weather Message Code: WATA30
Serial Number: 279
Issue Time: 2026 Jul 31 1105 UTC
WATCH: Geomagnetic Storm Category G2 Predicted \nHighest Storm Level Predicted by Day:\nJul 31: None (Below G1) Aug 01: None (Below G1) Aug 02: G2 (Moderate) \nTHIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT\nComment:
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: P11S
Issued: 2026-07-31 09:08:02.797
Message Follows:
Space Weather Message Code: SUMPX1
Serial Number: 132
Issue Time: 2026 Jul 31 0908 UTC
SUMMARY: Proton Event 10MeV Integral Flux exceeded 10pfu \nBegin Time: 2026 Jul 30 1845 UTC\nMaximum Time: 2026 Jul 30 2055 UTC\nEnd Time: 2026 Jul 31 0715 UTC\nMaximum 10MeV Flux: 18 pfu\nNoaa Scale: S1 - Minor\nComment:
NOAA Scale: S1 - Minor
-------------------
Product ID: P20A
Issued: 2026-07-31 01:56:29.630
Message Follows:
Space Weather Message Code: ALTPC0
Serial Number: 57
Issue Time: 2026 Jul 31 0156 UTC
CANCEL ALERT: Proton Event 100MeV Integral Flux exceeded 1pfu \nCancel Serial Number: 56\nOriginal Issue Time: 2026 Jul 30 1833 UTC\nThreshold was met at 30/1845 UTC and ended at 30/1850 UTC
-------------------
Product ID: P11A
Issued: 2026-07-30 19:03:19.350
Message Follows:
Space Weather Message Code: ALTPX1
Serial Number: 366
Issue Time: 2026 Jul 30 1903 UTC
ALERT: Proton Event 10meV Integral Flux exceeded 10pfu \nBegin Time: 2026 Jul 30 1903 UTC\nNoaa Scale: S1 - Minor\nComment:
NOAA Scale: S1 - Minor
-------------------
Product ID: P11W
Issued: 2026-07-30 18:34:42.033
Message Follows:
Space Weather Message Code: WARPX1
Serial Number: 628
Issue Time: 2026 Jul 30 1834 UTC
WARNING: Proton 10MeV Integral Flux above 10pfu expected \nValid From: 2026 Jul 30 1833 UTC\nValid To: 2026 Jul 31 0900 UTC\nWarning Conditions: Onset\nNoaa Scale: S1 - Minor\nComment:
NOAA Scale: S1 - Minor
-------------------
Product ID: P20A
Issued: 2026-07-30 18:33:22.693
Message Follows:
Space Weather Message Code: ALTPC0
Serial Number: 56
Issue Time: 2026 Jul 30 1833 UTC
ALERT: Proton Event 100MeV Integral Flux exceeded 1pfu \nBegin Time: 2026 Jul 30 1833 UTC\nComment:
-------------------
Product ID: P20W
Issued: 2026-07-30 18:08:39.780
Message Follows:
Space Weather Message Code: WARPC0
Serial Number: 122
Issue Time: 2026 Jul 30 1808 UTC
WARNING: Proton 100MeV Integral Flux above 1pfu expected \nValid From: 2026 Jul 30 1807 UTC\nValid To: 2026 Jul 31 0300 UTC\nWarning Conditions: Onset\nComment:
Current 2026 Jul 31 1205 UTC
Solar-terrestrial indices for 30 July follow.
Solar flux 152 and estimated planetary A-index 5.
The estimated planetary K-index at 1200 UTC on 31 July was 1.67.
Space weather for the past 24 hours has been minor.
Solar radiation storms reaching the S1 level occurred.
Radio blackouts reaching the R1 level occurred.
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 #26-29
2026 July 26 at 6:58 p.m. MDT (2026 July 27 0058 UTC)
**** SPACE WEATHER OUTLOOK ****
Summary For July 20-26
R1 (Minor) solar x-ray events were observed on 20-22 and 26 Jul.
G1 (Minor) solar geomagnetic events were observed on 23 Jul.
No other significant solar events were observed.
Outlook For July 27-August 2
A chance for R1 (Minor) and a slight chance for R2-R3 (Moderate-Strong) solar x-ray events are likely on 27 Jul - 02 Aug.
No other significant solar events are expected.