Viewing archive of Tuesday, 26 September 2023

Solar activity report

Report of Solar-Geophysical Activity 2023 Sep 26 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 269 Issued at 2200Z on 26 Sep 2023

IA. Analysis of Solar Active Regions and Activity from 25-2100Z to 26-2100Z

Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C5 event observed at 26/0428Z from Region 3445 (S13W23). There are currently 10 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 days one, two, and three (27 Sep, 28 Sep, 29 Sep).
IIA. Geophysical Activity Summary 25-2100Z to 26-2100Z
The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 532 km/s at 26/1736Z. Total IMF reached 18 nT at 25/2100Z. The maximum southward component of Bz reached -12 nT at 26/1018Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 765 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at quiet to active levels on days one and three (27 Sep, 29 Sep) and quiet to unsettled levels on day two (28 Sep). Protons have a slight chance of crossing threshold on days one and two (27 Sep, 28 Sep) and have a slight chance of crossing threshold on day three (29 Sep).
III. Event Probabilities 27 Sep to 29 Sep
Class M40%45%35%
Class X15%15%10%
IV. Penticton 10.7 cm Flux
  Observed       26 Sep 165
  Predicted   27 Sep-29 Sep 168/168/162
  90 Day Mean        26 Sep 162

V. Geomagnetic A Indices
  Observed Afr/Ap 25 Sep  015/021
  Estimated     Afr/Ap 26 Sep  026/033
  Predicted    Afr/Ap 27 Sep-29 Sep  011/012-007/008-009/012

VI. Geomagnetic Activity Probabilities 27 Sep to 29 Sep
A. Middle Latitudes
Minor storm10%05%10%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm20%20%25%
Major-severe storm30%20%30%

All times in UTC

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