Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 48 Issued at 2200Z on 17 Feb 2023

IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity has been at high levels for the past 24 hours. The largest solar event of the period was a X2 event observed at 17/2016Z. There are currently 6 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 (18 Feb, 19 Feb, 20 Feb).

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 557 km/s at 17/0300Z. Total IMF reached 15 nT at 17/0036Z. The maximum southward component of Bz reached -7 nT at 17/0155Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 190 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to major storm levels on day one (18 Feb), quiet to active levels on day two (19 Feb) and quiet to unsettled levels on day three (20 Feb). Protons have a slight chance of crossing threshold on days one, two, and three (18 Feb, 19 Feb, 20 Feb).

III. Event probabilities 18 Feb-20 Feb
Class M 50/50/50
Class X 15/15/15
Proton 15/15/15
PCAF green

IV. Penticton 10.7 cm Flux
Observed 17 Feb 343
Predicted 18 Feb-20 Feb 160/155/145
90 Day Mean 17 Feb 162

V. Geomagnetic A Indices
Observed Afr/Ap 16 Feb 021/027
Estimated Afr/Ap 17 Feb 011/015
Predicted Afr/Ap 18 Feb-20 Feb 023/030-012/015-008/008

VI. Geomagnetic Activity Probabilities 18 Feb-20 Feb
A. Middle Latitudes
Active 30/35/15
Minor Storm 40/15/01
Major-severe storm 20/01/01
B. High Latitudes
Active 05/10/15
Minor Storm 20/25/25
Major-severe storm 70/50/20

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