Viewing archive of Monday, 20 September 2021
Solar activity report
Report of Solar-Geophysical Activity 2021 Sep 20 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 263 Issued at 2200Z on 20 Sep 2021IA. Analysis of Solar Active Regions and Activity from 19-2100Z to 20-2100Z Solar activity has been at very low levels for the past 24
hours. 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 on days one, two, and three (21 Sep,
22 Sep, 23 Sep).
IIA. Geophysical Activity Summary 19-2100Z to 20-2100Z
The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
reached a peak of 327 km/s at 20/0346Z. Electrons greater than 2 MeV at
geosynchronous orbit reached a peak level of 124 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at quiet to unsettled levels on days one and two (21 Sep, 22 Sep)
and quiet to active levels on day three (23 Sep).
III. Event Probabilities 21 Sep to 23 Sep
| Class M | 05% | 05% | 05% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 20 Sep 079 Predicted 21 Sep-23 Sep 075/075/077 90 Day Mean 20 Sep 082
V. Geomagnetic A Indices
Observed Afr/Ap 19 Sep 002/002 Estimated Afr/Ap 20 Sep 004/004 Predicted Afr/Ap 21 Sep-23 Sep 007/008-008/008-008/012
VI. Geomagnetic Activity Probabilities 21 Sep to 23 Sep
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 20% | 20% | 30% |
| Minor storm | 05% | 05% | 10% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 20% | 20% | 15% |
| Minor storm | 30% | 30% | 25% |
| Major-severe storm | 25% | 25% | 40% |
All times in UTC
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