Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 146 Issued at 2200Z on 26 May 2023

IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C5 event observed at 26/1754Z from Region 3314 (N15W45). 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 on days one, two, and three (27 May, 28 May, 29 May).

IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 588 km/s at 25/2232Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 4078 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one and two (27 May, 28 May) and quiet to active levels on day three (29 May).

III. Event probabilities 27 May-29 May
Class M 30/30/30
Class X 05/05/05
Proton 05/05/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 26 May 149
Predicted 27 May-29 May 148/148/145
90 Day Mean 26 May 153

V. Geomagnetic A Indices
Observed Afr/Ap 25 May 011/010
Estimated Afr/Ap 26 May 006/006
Predicted Afr/Ap 27 May-29 May 005/005-005/005-009/012

VI. Geomagnetic Activity Probabilities 27 May-29 May
A. Middle Latitudes
Active 10/10/30
Minor Storm 01/05/15
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/20/20
Major-severe storm 20/15/30

space weather