Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 149 Issued at 2200Z on 29 May 2023

IA. Analysis of Solar Active Regions and Activity from 28/2100Z to 29/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C6 event observed at 29/1829Z from Region 3315 (S16W34). There are currently 10 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 (30 May, 31 May, 01 Jun).

IIA. Geophysical Activity Summary 28/2100Z to 29/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 463 km/s at 28/2224Z. Total IMF reached 6 nT at 29/1613Z. The maximum southward component of Bz reached -4 nT at 29/1632Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 277 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (30 May), quiet to unsettled levels on day two (31 May) and quiet levels on day three (01 Jun). Protons have a slight chance of crossing threshold on days one, two, and three (30 May, 31 May, 01 Jun).

III. Event probabilities 30 May-01 Jun
Class M 40/40/40
Class X 10/10/10
Proton 10/10/10
PCAF green

IV. Penticton 10.7 cm Flux
Observed 29 May 154
Predicted 30 May-01 Jun 150/140/135
90 Day Mean 29 May 153

V. Geomagnetic A Indices
Observed Afr/Ap 28 May 011/013
Estimated Afr/Ap 29 May 007/008
Predicted Afr/Ap 30 May-01 Jun 009/010-008/008-006/005

VI. Geomagnetic Activity Probabilities 30 May-01 Jun
A. Middle Latitudes
Active 20/10/10
Minor Storm 05/01/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/25/20
Major-severe storm 25/20/15

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