Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 May 2018

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 141 Issued at 2200Z on 21 May 2018

IA.  Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 1 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be very low on days one, two, and three (22 May, 23 May, 24 May).

IIA.  Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 425 km/s at 21/0042Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 846 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (22 May, 23 May) and quiet to unsettled levels on day three (24 May).

III.  Event probabilities 22 May-24 May
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           21 May 070
Predicted   22 May-24 May 070/071/071
90 Day Mean        21 May 069

V.  Geomagnetic A Indices
Observed Afr/Ap 20 May  003/003
Estimated Afr/Ap 21 May  004/004
Predicted Afr/Ap 22 May-24 May  011/012-011/012-007/008

VI.  Geomagnetic Activity Probabilities 22 May-24 May
A.  Middle Latitudes
Active                30/30/15
Minor Storm           10/10/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           30/30/25
Major-severe storm    40/40/25