Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 49 Issued at 2200Z on 18 Feb 2023
IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C7 event observed at 18/1200Z from Region 3226 (N10W33). 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 and a slight chance for an X-class flare on days one, two, and three (19 Feb, 20 Feb, 21 Feb).
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 490 km/s at 17/2348Z. Total IMF reached 5 nT at 18/1222Z. The maximum southward component of Bz reached -5 nT at 18/1243Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 225 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and three (19 Feb, 21 Feb) and unsettled to minor storm levels on day two (20 Feb). Protons have a chance of crossing threshold on day one (19 Feb) and have a slight chance of crossing threshold on days two and three (20 Feb, 21 Feb).
III. Event probabilities 19 Feb-21 Feb
Class M 50/50/50
Class X 15/15/15
Proton 25/15/15
PCAF green
IV. Penticton 10.7 cm Flux
Observed 18 Feb 167
Predicted 19 Feb-21 Feb 160/150/140
90 Day Mean 18 Feb 162
V. Geomagnetic A Indices
Observed Afr/Ap 17 Feb 004/005
Estimated Afr/Ap 18 Feb 008/011
Predicted Afr/Ap 19 Feb-21 Feb 012/020-017/025-012/012
VI. Geomagnetic Activity Probabilities 19 Feb-21 Feb
A. Middle Latitudes
Active 30/40/35
Minor Storm 15/30/15
Major-severe storm 05/10/01
B. High Latitudes
Active 10/05/10
Minor Storm 25/20/30
Major-severe storm 45/70/50
Space Weather
