Viewing archive of Wednesday, 27 September 2023

Solar activity report

Report of Solar-Geophysical Activity 2023 Sep 27 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 270 Issued at 2200Z on 27 Sep 2023

IA. Analysis of Solar Active Regions and Activity from 26-2100Z to 27-2100Z

Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C4 event observed at 27/0546Z. There are currently 8 numbered sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be low with a chance for M-class flares and a slight chance for an X-class flare on day one (28 Sep) and expected to be low with a chance for M-class flares on days two and three (29 Sep, 30 Sep).
IIA. Geophysical Activity Summary 26-2100Z to 27-2100Z
The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 529 km/s at 26/2104Z. Total IMF reached 6 nT at 27/0456Z. The maximum southward component of Bz reached -4 nT at 27/1807Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 3755 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at quiet to unsettled levels on days one and two (28 Sep, 29 Sep) and quiet to active levels on day three (30 Sep). Protons greater than 10 Mev have a slight chance of crossing threshold on day one (28 Sep).
III. Event Probabilities 28 Sep to 30 Sep
Class M35%30%30%
Class X10%05%05%
IV. Penticton 10.7 cm Flux
  Observed       27 Sep 156
  Predicted   28 Sep-30 Sep 160/158/155
  90 Day Mean        27 Sep 162

V. Geomagnetic A Indices
  Observed Afr/Ap 26 Sep  026/032
  Estimated     Afr/Ap 27 Sep  014/016
  Predicted    Afr/Ap 28 Sep-30 Sep  007/008-007/008-010/012

VI. Geomagnetic Activity Probabilities 28 Sep to 30 Sep
A. Middle Latitudes
Minor storm05%05%10%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm20%20%30%
Major-severe storm20%20%40%

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