Viewing archive of Wednesday, 21 April 2021
Solar activity report
Report of Solar-Geophysical Activity 2021 Apr 21 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 111 Issued at 2200Z on 21 Apr 2021IA. 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.
The largest solar event of the period was a C1 event observed at
21/0129Z from Region 2817 (N18W79). There are currently 3 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 and a slight chance for an M-class
flare on day one (22 Apr) and expected to be very low with a chance for
a C-class flares on day two (23 Apr) and expected to be very low with a
slight chance for a C-class flare on day three (24 Apr).
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 605 km/s at 20/2101Z. Total IMF reached 5
nT at 21/0109Z. The maximum southward component of Bz reached -3 nT at
21/0548Z. Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 12719 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at quiet levels on day one (22 Apr) and quiet to active levels on
days two and three (23 Apr, 24 Apr).
III. Event Probabilities 22 Apr to 24 Apr
| Class M | 10% | 05% | 01% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 21 Apr 078 Predicted 22 Apr-24 Apr 080/078/078 90 Day Mean 21 Apr 076
V. Geomagnetic A Indices
Observed Afr/Ap 20 Apr 010/012 Estimated Afr/Ap 21 Apr 007/008 Predicted Afr/Ap 22 Apr-24 Apr 005/005-009/010-009/010
VI. Geomagnetic Activity Probabilities 22 Apr to 24 Apr
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 15% | 40% | 40% |
| Minor storm | 01% | 15% | 15% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 10% | 10% |
| Minor storm | 20% | 25% | 25% |
| Major-severe storm | 20% | 50% | 50% |
All times in UTC
Latest news
Saturday, 14 September 2024
X4.5 solar flare with a fast coronal mass ejection
Thursday, 12 September 2024
G3 geomagnetic storm watch due to CME passage
Monday, 12 August 2024
Severe G4 geomagnetic storm
Latest forum messages
More topicsSupport SpaceWeatherLive.com!
A lot of people come to SpaceWeatherLive to follow the Sun's activity or if there is aurora to be seen, but with more traffic comes higher server costs. Consider a donation if you enjoy SpaceWeatherLive so we can keep the website online!
Space weather facts
| Last X-flare | 2024/09/14 | X4.54 |
| Last M-flare | 2024/09/14 | M3.0 |
| Last geomagnetic storm | 2024/09/17 | Kp8- (G4) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| August 2024 | 215.5 +19 |
| September 2024 | 149.4 -66.1 |
| Last 30 days | 156.7 -55.8 |