Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 177 Issued at 2200Z on 26 Jun 2023

IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M1 event observed at 26/1622Z from Region 3340 (N20W45). 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 Jun, 28 Jun, 29 Jun).

IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 646 km/s at 25/2210Z. Total IMF reached 7 nT at 25/2108Z. The maximum southward component of Bz reached -5 nT at 26/1350Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 583 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (27 Jun), quiet to unsettled levels on day two (28 Jun) and quiet levels on day three (29 Jun).

III. Event probabilities 27 Jun-29 Jun
Class M 40/40/40
Class X 10/10/10
Proton 05/05/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 26 Jun 158
Predicted 27 Jun-29 Jun 160/160/155
90 Day Mean 26 Jun 154

V. Geomagnetic A Indices
Observed Afr/Ap 25 Jun 010/015
Estimated Afr/Ap 26 Jun 008/011
Predicted Afr/Ap 27 Jun-29 Jun 010/012-007/010-007/008

VI. Geomagnetic Activity Probabilities 27 Jun-29 Jun
A. Middle Latitudes
Active 30/25/20
Minor Storm 15/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/20/15
Minor Storm 20/20/20
Major-severe storm 35/15/20

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