Viewing archive of Tuesday, 28 September 2021
Solar activity report
Report of Solar-Geophysical Activity 2021 Sep 28 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 271 Issued at 2200Z on 28 Sep 2021IA. Analysis of Solar Active Regions and Activity from 27-2100Z to 28-2100Z 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
28/0634Z. There are currently 4 numbered sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be very low
with a slight chance for a C-class flare on days one, two, and three (29
Sep, 30 Sep, 01 Oct).
IIA. Geophysical Activity Summary 27-2100Z to 28-2100Z
The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 548 km/s at 28/1209Z. Total IMF reached 13
nT at 27/2141Z. The maximum southward component of Bz reached -8 nT at
27/2235Z. Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 290 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at quiet to active levels on days one and two (29 Sep, 30 Sep) and
quiet to minor storm levels on day three (01 Oct).
III. Event Probabilities 29 Sep to 01 Oct
| Class M | 01% | 01% | 01% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 28 Sep 089 Predicted 29 Sep-01 Oct 088/084/082 90 Day Mean 28 Sep 082
V. Geomagnetic A Indices
Observed Afr/Ap 27 Sep 006/006 Estimated Afr/Ap 28 Sep 010/010 Predicted Afr/Ap 29 Sep-01 Oct 009/010-011/012-018/024
VI. Geomagnetic Activity Probabilities 29 Sep to 01 Oct
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 30% | 35% | 45% |
| Minor storm | 10% | 10% | 30% |
| Major-severe storm | 01% | 01% | 05% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 05% |
| Minor storm | 30% | 30% | 20% |
| Major-severe storm | 40% | 45% | 70% |
All times in UTC
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