:Product: 0316RSGA.txt :Issued: 2026 Mar 16 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 75 Issued at 2200Z on 16 Mar 2026 IA. Analysis of Solar Active Regions and Activity from 15/2100Z to 16/2100Z: 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 and two (17 Mar, 18 Mar) and expected to be low with a slight chance for an M-class flare on day three (19 Mar). IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 661 km/s at 15/2145Z. Total IMF reached 6 nT at 16/1233Z. The maximum southward component of Bz reached -4 nT at 16/1133Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2212 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and two (17 Mar, 18 Mar) and quiet to major storm levels on day three (19 Mar). Protons greater than 10 Mev have a slight chance of crossing threshold on day three (19 Mar). III. Event probabilities 17 Mar-19 Mar Class M 25/25/15 Class X 05/05/05 Proton 05/05/10 PCAF green IV. Penticton 10.7 cm Flux Observed 16 Mar 111 Predicted 17 Mar-19 Mar 110/112/112 90 Day Mean 16 Mar 142 V. Geomagnetic A Indices Observed Afr/Ap 15 Mar 014/017 Estimated Afr/Ap 16 Mar 012/014 Predicted Afr/Ap 17 Mar-19 Mar 008/010-007/008-028/040 VI. Geomagnetic Activity Probabilities 17 Mar-19 Mar A. Middle Latitudes Active 25/20/25 Minor Storm 05/05/35 Major-severe storm 01/01/25 B. High Latitudes Active 15/15/05 Minor Storm 30/25/15 Major-severe storm 30/25/75