:Product: 0317RSGA.txt :Issued: 2026 Mar 17 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 76 Issued at 2200Z on 17 Mar 2026 IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity has been at moderate levels for the past 24 hours. There are currently 4 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 (18 Mar, 19 Mar, 20 Mar). IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 542 km/s at 16/2142Z. Total IMF reached 5 nT at 17/1102Z. The maximum southward component of Bz reached -2 nT at 17/0431Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2232 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (18 Mar), quiet to major storm levels on day two (19 Mar) and unsettled to minor storm levels on day three (20 Mar). Protons greater than 10 Mev have a slight chance of crossing threshold on days two and three (19 Mar, 20 Mar). III. Event probabilities 18 Mar-20 Mar Class M 35/35/35 Class X 05/05/05 Proton 05/10/10 PCAF green IV. Penticton 10.7 cm Flux Observed 17 Mar 111 Predicted 18 Mar-20 Mar 112/110/110 90 Day Mean 17 Mar 142 V. Geomagnetic A Indices Observed Afr/Ap 16 Mar 010/010 Estimated Afr/Ap 17 Mar 006/007 Predicted Afr/Ap 18 Mar-20 Mar 007/008-028/040-021/028 VI. Geomagnetic Activity Probabilities 18 Mar-20 Mar A. Middle Latitudes Active 20/25/35 Minor Storm 05/35/35 Major-severe storm 01/25/15 B. High Latitudes Active 15/05/05 Minor Storm 25/15/20 Major-severe storm 25/75/70