:Product: 0604RSGA.txt :Issued: 2025 Jun 04 2200 UTC # Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Weather Prediction Center and the U.S. Air Force. # Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 155 Issued at 2200Z on 04 Jun 2025 IA. Analysis of Solar Active Regions and Activity from 03/2100Z to 04/2100Z: Solar activity has been at low levels for the past 24 hours. There are currently 5 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 (05 Jun, 06 Jun, 07 Jun). IIA. Geophysical Activity Summary 03/2100Z to 04/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 834 km/s at 04/1826Z. Total IMF reached 15 nT at 04/1356Z. The maximum southward component of Bz reached -12 nT at 04/1445Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 3973 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to major storm levels on day one (05 Jun), quiet to active levels on day two (06 Jun) and quiet to minor storm levels on day three (07 Jun). Protons have a slight chance of crossing threshold on days one, two, and three (05 Jun, 06 Jun, 07 Jun). III. Event probabilities 05 Jun-07 Jun Class M 45/45/45 Class X 10/10/10 Proton 10/10/10 PCAF green IV. Penticton 10.7 cm Flux Observed 04 Jun 134 Predicted 05 Jun-07 Jun 135/130/125 90 Day Mean 04 Jun 153 V. Geomagnetic A Indices Observed Afr/Ap 03 Jun 032/ 058 Estimated Afr/Ap 04 Jun 017/027 Predicted Afr/Ap 05 Jun-07 Jun 024/033-014/015-014/018 VI. Geomagnetic Activity Probabilities 05 Jun-07 Jun A. Middle Latitudes Active 35/35/35 Minor Storm 35/15/25 Major-severe storm 20/01/05 B. High Latitudes Active 05/15/10 Minor Storm 20/30/25 Major-severe storm 75/50/60