Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 23 May 2018

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 143 Issued at 2200Z on 23 May 2018

IA.  Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C2 event observed at 23/1821Z. There are currently 2 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares on days one, two, and three (24 May, 25 May, 26 May).

IIA.  Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 548 km/s at 23/1718Z. Total IMF reached 11 nT at 23/0546Z. The maximum southward component of Bz reached -9 nT at 23/0523Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 812 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (24 May), quiet to unsettled levels on day two (25 May) and quiet levels on day three (26 May).

III.  Event probabilities 24 May-26 May
Class M    05/05/05
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           23 May 073
Predicted   24 May-26 May 074/075/075
90 Day Mean        23 May 069

V.  Geomagnetic A Indices
Observed Afr/Ap 22 May  055/006
Estimated Afr/Ap 23 May  010/012
Predicted Afr/Ap 24 May-26 May  008/010-008/008-005/005

VI.  Geomagnetic Activity Probabilities 24 May-26 May
A.  Middle Latitudes
Active                30/25/15
Minor Storm           10/05/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           30/30/20
Major-severe storm    40/30/20