Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 142 Issued at 2200Z on 22 May 2023
IA. Analysis of Solar Active Regions and Activity from 21/2100Z to 22/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a M1 event observed at 22/1337Z from Region 3312 (S23E32). There are currently 5 numbered sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is likely to be moderate with a slight chance for an X-class flare on day one (23 May) and expected to be low with a chance for M-class flares and a slight chance for an X-class flare on days two and three (24 May, 25 May).
IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic field has been at unsettled to major storm levels for the past 24 hours. Solar wind speed reached a peak of 628 km/s at 22/1740Z. Total IMF reached 10 nT at 22/1944Z. The maximum southward component of Bz reached -9 nT at 22/1957Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1267 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (23 May), unsettled to minor storm levels on day two (24 May) and unsettled to active levels on day three (25 May). Protons have a slight chance of crossing threshold on days one, two, and three (23 May, 24 May, 25 May).
III. Event probabilities 23 May-25 May
Class M 60/50/50
Class X 20/10/10
Proton 10/10/10
PCAF green
IV. Penticton 10.7 cm Flux
Observed 22 May 162
Predicted 23 May-25 May 155/155/155
90 Day Mean 22 May 153
V. Geomagnetic A Indices
Observed Afr/Ap 21 May 019/026
Estimated Afr/Ap 22 May 019/025
Predicted Afr/Ap 23 May-25 May 014/018-020/022-011/015
VI. Geomagnetic Activity Probabilities 23 May-25 May
A. Middle Latitudes
Active 35/35/35
Minor Storm 20/30/20
Major-severe storm 05/15/05
B. High Latitudes
Active 15/15/20
Minor Storm 20/25/30
Major-severe storm 20/50/30
space weather
