Viewing archive of Monday, 27 September 2021
Solar activity report
Report of Solar-Geophysical Activity 2021 Sep 27 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 270 Issued at 2200Z on 27 Sep 2021IA. Analysis of Solar Active Regions and Activity from 26-2100Z to 27-2100Z Solar activity has been at very low levels for the past 24
hours. There are currently 2 numbered sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be very low
with a chance for a C-class flares on day one (28 Sep) and expected to
be very low with a slight chance for a C-class flare on days two and
three (29 Sep, 30 Sep).
IIA. Geophysical Activity Summary 26-2100Z to 27-2100Z
The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 404 km/s at 27/2059Z. Total IMF reached 14
nT at 27/1902Z. The maximum southward component of Bz reached -5 nT at
27/0145Z. Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 696 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at quiet to major storm levels on day one (28 Sep), quiet to minor
storm levels on day two (29 Sep) and quiet to unsettled levels on day
three (30 Sep).
III. Event Probabilities 28 Sep to 30 Sep
| Class M | 01% | 01% | 01% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 27 Sep 085 Predicted 28 Sep-30 Sep 086/084/080 90 Day Mean 27 Sep 082
V. Geomagnetic A Indices
Observed Afr/Ap 26 Sep 002/002 Estimated Afr/Ap 27 Sep 013/021 Predicted Afr/Ap 28 Sep-30 Sep 023/030-013/015-007/008
VI. Geomagnetic Activity Probabilities 28 Sep to 30 Sep
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 30% | 45% | 15% |
| Minor storm | 40% | 30% | 05% |
| Major-severe storm | 15% | 05% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 05% | 05% | 20% |
| Minor storm | 20% | 20% | 25% |
| Major-severe storm | 75% | 70% | 20% |
All times in UTC
Latest news
Monday, 30 March 2026
X1.5 solar flare
Tuesday, 17 March 2026
M2.7 solar flare, CME arrival possible
Sunday, 1 February 2026
Complex sunspot region 4366
Latest forum messages
GoPro tips -which model, what settings etc 8JHelioviewer Tips and Settings 52AR4413 12Artemis 2 Live 6Space Weather Memes 819
More topicsSupport SpaceWeatherLive.com!
A lot of people come to SpaceWeatherLive to follow the Solar activity or if there is a chance to see the aurora, but with more traffic comes higher costs to keep the servers online. If you like SpaceWeatherLive and want to support the project you can choose a subscription for an ad-free site or consider a donation. With your help we can keep SpaceWeatherLive online!
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 | 118.8 +32.8 |
| Last 30 days | 102.1 +47 |
This day in history*
Aurora on this day in history
No observations submitted for this day in history. If you've observed the aurora and you have some amazing photos to show off, submit your observations now!
Submit your aurora observation