Viewing archive of Thursday, 21 August 2025
Solar activity report
Report of Solar-Geophysical Activity 2025 Aug 21 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 233 Issued at 2200Z on 21 Aug 2025IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z Solar activity has been at low levels for the past 24 hours.
There are currently 6 numbered sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is likely to be low with a
slight chance for an M-class flare on days one and two (22 Aug, 23 Aug)
and expected to be low with a chance for M-class flares on day three (24
Aug).
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 672 km/s at 21/0638Z. Total IMF reached 7
nT at 21/1036Z. The maximum southward component of Bz reached -5 nT at
21/1946Z. Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 1125 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at quiet to unsettled levels on day one (22 Aug) and quiet levels
on days two and three (23 Aug, 24 Aug).
III. Event Probabilities 22 Aug to 24 Aug
| Class M | 15% | 20% | 25% |
| Class X | 01% | 01% | 05% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 21 Aug 121 Predicted 22 Aug-24 Aug 125/125/130 90 Day Mean 21 Aug 136
V. Geomagnetic A Indices
Observed Afr/Ap 20 Aug 012/012 Estimated Afr/Ap 21 Aug 007/008 Predicted Afr/Ap 22 Aug-24 Aug 008/008-006/005-006/005
VI. Geomagnetic Activity Probabilities 22 Aug to 24 Aug
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 20% | 10% | 10% |
| Minor storm | 05% | 01% | 01% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 15% |
| Minor storm | 30% | 20% | 20% |
| Major-severe storm | 25% | 20% | 20% |
All times in UTC
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Space weather facts
| Last X-flare | 2026/03/30 | X1.5 |
| Last M-flare | 2026/04/04 | M1.0 |
| Last geomagnetic storm | 2026/04/03 | Kp7- (G3) |
| Spotless days | |
|---|---|
| Last 365 days | 3 days |
| 2026 | 3 days (3%) |
| Last spotless day | 2026/02/24 |
| Monthly mean Sunspot Number | |
|---|---|
| March 2026 | 85.9 +7.7 |
| April 2026 | 128.3 +42.3 |
| Last 30 days | 97.5 +35.7 |
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