Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 204 Issued at 2200Z on 23 Jul 2023

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 C9 event observed at 23/0454Z from Region 3373 (N09W57). There are currently 7 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares on days one, two, and three (24 Jul, 25 Jul, 26 Jul).

IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 484 km/s at 23/1944Z. Total IMF reached 7 nT at 23/1811Z. The maximum southward component of Bz reached -6 nT at 23/1909Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 202 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (24 Jul), quiet to unsettled levels on day two (25 Jul) and quiet levels on day three (26 Jul).

III. Event probabilities 24 Jul-26 Jul
Class M 45/30/25
Class X 05/05/05
Proton 05/05/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 23 Jul 173
Predicted 24 Jul-26 Jul 165/165/160
90 Day Mean 23 Jul 163

V. Geomagnetic A Indices
Observed Afr/Ap 22 Jul 009/008
Estimated Afr/Ap 23 Jul 006/006
Predicted Afr/Ap 24 Jul-26 Jul 009/012-010/010-005/005

VI. Geomagnetic Activity Probabilities 24 Jul-26 Jul
A. Middle Latitudes
Active 25/15/15
Minor Storm 10/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/20/15
Major-severe storm 25/20/10

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