Viewing archive of Tuesday, 20 April 2021
Solar activity report
Report of Solar-Geophysical Activity 2021 Apr 20 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 110 Issued at 2200Z on 20 Apr 2021IA. Analysis of Solar Active Regions and Activity from 19-2100Z to 20-2100Z Solar activity has been at moderate levels for the past 24
hours. The largest solar event of the period was a M1 event observed at
19/2342Z from Region 2816 (S24E21). There are currently 3 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 (21 Apr, 22 Apr)
and expected to be very low with a chance for a C-class flares and a
slight chance for an M-class flare on day three (23 Apr).
IIA. Geophysical Activity Summary 19-2100Z to 20-2100Z
The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 687 km/s at 19/2348Z. Total IMF reached 6
nT at 20/0222Z. The maximum southward component of Bz reached -5 nT at
19/2342Z. Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 13356 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at quiet to unsettled levels on days one and three (21 Apr, 23
Apr) and quiet levels on day two (22 Apr).
III. Event Probabilities 21 Apr to 23 Apr
| Class M | 15% | 15% | 10% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 20 Apr 080 Predicted 21 Apr-23 Apr 084/082/082 90 Day Mean 20 Apr 076
V. Geomagnetic A Indices
Observed Afr/Ap 19 Apr 015/020 Estimated Afr/Ap 20 Apr 011/012 Predicted Afr/Ap 21 Apr-23 Apr 006/005-005/005-007/008
VI. Geomagnetic Activity Probabilities 21 Apr to 23 Apr
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 25% |
| Minor storm | 01% | 01% | 10% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 15% |
| Minor storm | 25% | 20% | 30% |
| Major-severe storm | 20% | 20% | 40% |
All times in UTC
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