:Product: Report of Solar-Geophysical Activity :Issued: 2024 Mar 18 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 78 Issued at 2200Z on 18 Mar 2024 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity has been at high levels for the past 24 hours. The largest solar event of the period was a M6 event observed at 18/1919Z from Region 3615 (S12E62). 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 (19 Mar, 20 Mar, 21 Mar). IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 420 km/s at 18/0821Z. Total IMF reached 9 nT at 18/2006Z. The maximum southward component of Bz reached -8 nT at 18/2007Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 355 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (19 Mar) and quiet to minor storm levels on days two and three (20 Mar, 21 Mar). III. Event probabilities 19 Mar-21 Mar Class M 40/40/40 Class X 05/05/05 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 18 Mar 177 Predicted 19 Mar-21 Mar 170/170/168 90 Day Mean 18 Mar 162 V. Geomagnetic A Indices Observed Afr/Ap 17 Mar 002/003 Estimated Afr/Ap 18 Mar 004/005 Predicted Afr/Ap 19 Mar-21 Mar 006/005-014/018-015/020 VI. Geomagnetic Activity Probabilities 19 Mar-21 Mar A. Middle Latitudes Active 05/40/40 Minor Storm 05/25/25 Major-severe storm 01/05/05 B. High Latitudes Active 15/05/05 Minor Storm 15/20/20 Major-severe storm 15/65/65