Viewing archive of Friday, 23 April 2021

Solar activity report

Report of Solar-Geophysical Activity 2021 Apr 23 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 113 Issued at 2200Z on 23 Apr 2021

IA. Analysis of Solar Active Regions and Activity from 22-2100Z to 23-2100Z

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 23/0252Z from Region 2817 (N18, L=336). There are currently 2 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, two, and three (24 Apr, 25 Apr, 26 Apr).
IIA. Geophysical Activity Summary 22-2100Z to 23-2100Z
The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 426 km/s at 23/0246Z. Total IMF reached 10 nT at 23/2100Z. The maximum southward component of Bz reached -6 nT at 23/2045Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 19293 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at quiet to active levels on days one and three (24 Apr, 26 Apr) and quiet to major storm levels on day two (25 Apr).
III. Event Probabilities 24 Apr to 26 Apr
Class M10%10%10%
Class X01%01%01%
IV. Penticton 10.7 cm Flux
  Observed       23 Apr 077
  Predicted   24 Apr-26 Apr 077/077/077
  90 Day Mean        23 Apr 076

V. Geomagnetic A Indices
  Observed Afr/Ap 22 Apr  004/005
  Estimated     Afr/Ap 23 Apr  011/013
  Predicted    Afr/Ap 24 Apr-26 Apr  011/012-019/025-013/015

VI. Geomagnetic Activity Probabilities 24 Apr to 26 Apr
A. Middle Latitudes
Minor storm10%35%15%
Major-severe storm01%10%05%
B. High Latitudes
Minor storm25%20%30%
Major-severe storm40%75%50%

All times in UTC

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