Product: Forecast Discussion Issued: 2021 Aug 05 0030 UTC Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
.24 hr Summary… Solar activity was very low with one sunspot group, Region 2850 (S31W55, Bxo/beta) present on the visible disk. The region decayed further, but produced a B5 X-ray enhancement at 04/0329 UTC. Another active region at approximately S11E53 developed pores later in the period, but as of this report they had not yet warranted spot status. No Earth-directed CMEs were observed in available coronagraph imagery.
.Forecast… Very low solar activity is expected 05-07 Aug, with a slight chance for C-class flares 05-06 Aug.
.24 hr Summary… The greater than 2 MeV electron flux was normal to moderate, with a few brief increases to high levels – but these were intermittent and were not sustained to meet alert criteria. The greater than 10 MeV proton flux remained at background values.
.Forecast… The greater than 2 MeV electron flux is expected to be normal to moderate, with a chance for high levels 05-07 Aug; while the greater than 10 MeV proton flux is expected to continue at background levels.
.24 hr Summary… Solar wind parameters were indicative of a slow regime and likely HCS proximity. Total IMF strength decreased from a peak of 6 nT down to mainly 2-4 nT. The Bz component underwent only weak deviations. Solar wind speed was primarily 325-350 km/s and the phi angle varied between sectors.
.Forecast… The approach of a CIR ahead of an isolated, positive polarity CH HSS will likely lead to a mild enhancement and disturbance in the IMF on 05 Aug. CIR arrival and CH HSS onset are likely on 06 Aug, further disturbing and enhancing the solar wind field. Conditions will likely begin weakening on 07 Aug.
.24 hr Summary… The geomagnetic field was quiet.
.Forecast… The geomagnetic field is expected to be quiet to unsettled on 05 Aug in response to mild solar wind enhancements. Additional enhancements due to CIR arrival and CH HSS effects will likely lead to unsettled to active periods on 06 Aug. Waning CH HSS influences on 07 Aug are expected to decrease responses to the quiet to unsettled levels.
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