Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 28 May 2018

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 148 Issued at 2200Z on 28 May 2018

IA.  Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: 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 28/1710Z from Region 2712 (N15E18). There are currently 1 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 (29 May, 30 May, 31 May).

IIA.  Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 421 km/s at 28/0745Z. Total IMF reached 6 nT at 28/1852Z. The maximum southward component of Bz reached -4 nT at 27/2127Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 301 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one, two, and three (29 May, 30 May, 31 May).

III.  Event probabilities 29 May-31 May
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           28 May 077
Predicted   29 May-31 May 076/076/076
90 Day Mean        28 May 070

V.  Geomagnetic A Indices
Observed Afr/Ap 27 May  005/004
Estimated Afr/Ap 28 May  005/006
Predicted Afr/Ap 29 May-31 May  006/006-005/005-006/005

VI.  Geomagnetic Activity Probabilities 29 May-31 May
A.  Middle Latitudes
Active                15/10/10
Minor Storm           05/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/20/15
Major-severe storm    20/15/10