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Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 293 Issued at 2200Z on 20 Oct 2023

By Keith Cowing
Press Release
NOAA SWPC
October 21, 2023
Filed under , , ,
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 293 Issued at 2200Z on 20 Oct 2023
space weather
NOAA SWPC

IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C2 event observed at 20/0500Z. There are currently 4 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be low on days one, two, and three (21 Oct, 22 Oct, 23 Oct).

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 378 km/s at 20/1208Z. Total IMF reached 10 nT at 20/1743Z. The maximum southward component of Bz reached -8 nT at 20/1847Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 183 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (21 Oct) and quiet to unsettled levels on days two and three (22 Oct, 23 Oct).

III. Event probabilities 21 Oct-23 Oct
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 20 Oct 126
Predicted 21 Oct-23 Oct 124/124/122
90 Day Mean 20 Oct 155

V. Geomagnetic A Indices
Observed Afr/Ap 19 Oct 008/010
Estimated Afr/Ap 20 Oct 009/014
Predicted Afr/Ap 21 Oct-23 Oct 010/012-010/012-008/010

VI. Geomagnetic Activity Probabilities 21 Oct-23 Oct
A. Middle Latitudes
Active 30/25/20
Minor Storm 10/10/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/25/25
Major-severe storm 40/35/25

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