Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 51 Issued at 2200Z on 20 Feb 2023

IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M4 event observed at 20/1458Z from Region 3234 (N24E76). There are currently 9 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 (21 Feb, 22 Feb, 23 Feb).

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 492 km/s at 20/1301Z. Total IMF reached 15 nT at 20/1139Z. The maximum southward component of Bz reached -6 nT at 20/1822Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 471 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (21 Feb, 22 Feb) and quiet to unsettled levels on day three (23 Feb). Protons have a slight chance of crossing threshold on days one, two, and three (21 Feb, 22 Feb, 23 Feb).

III. Event probabilities 21 Feb-23 Feb
Class M 50/50/50
Class X 15/15/15
Proton 15/15/15
PCAF green

IV. Penticton 10.7 cm Flux
Observed 20 Feb 160
Predicted 21 Feb-23 Feb 158/156/152
90 Day Mean 20 Feb 163

V. Geomagnetic A Indices
Observed Afr/Ap 19 Feb 004/005
Estimated Afr/Ap 20 Feb 012/015
Predicted Afr/Ap 21 Feb-23 Feb 012/015-010/012-007/010

VI. Geomagnetic Activity Probabilities 21 Feb-23 Feb
A. Middle Latitudes
Active 40/30/20
Minor Storm 15/10/05
Major-severe storm 01/01/01
B. High Latitudes
Active 10/15/20
Minor Storm 25/30/30
Major-severe storm 50/40/25

space weather