Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 20 September 2018

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 263 Issued at 2200Z on 20 Sep 2018

IA.  Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 0 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be very low on days one, two, and three (21 Sep, 22 Sep, 23 Sep).

IIA.  Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 433 km/s at 20/0041Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 8688 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (21 Sep), quiet to unsettled levels on day two (22 Sep) and unsettled to minor storm levels on day three (23 Sep).

III.  Event probabilities 21 Sep-23 Sep
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           20 Sep 067
Predicted   21 Sep-23 Sep 067/067/067
90 Day Mean        20 Sep 069

V.  Geomagnetic A Indices
Observed Afr/Ap 19 Sep  004/005
Estimated Afr/Ap 20 Sep  003/003
Predicted Afr/Ap 21 Sep-23 Sep  005/005-008/010-017/022

VI.  Geomagnetic Activity Probabilities 21 Sep-23 Sep
A.  Middle Latitudes
Active                15/25/35
Minor Storm           01/10/25
Major-severe storm    01/01/05
B.  High Latitudes
Active                15/15/10
Minor Storm           20/30/30
Major-severe storm    20/40/55