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

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 264 Issued at 2200Z on 21 Sep 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 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 (22 Sep, 23 Sep, 24 Sep).

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 376 km/s at 21/1651Z. Total IMF reached 8 nT at 21/2100Z. The maximum southward component of Bz reached -6 nT at 21/2057Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 10457 pfu.

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

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

IV.  Penticton 10.7 cm Flux
Observed           21 Sep 067
Predicted   22 Sep-24 Sep 067/067/067
90 Day Mean        21 Sep 069

V.  Geomagnetic A Indices
Observed Afr/Ap 20 Sep  002/ NA
Estimated Afr/Ap 21 Sep  004/005
Predicted Afr/Ap 22 Sep-24 Sep  008/010-017/022-013/016

VI.  Geomagnetic Activity Probabilities 22 Sep-24 Sep
A.  Middle Latitudes
Active                25/35/30
Minor Storm           10/25/10
Major-severe storm    01/05/01
B.  High Latitudes
Active                15/10/15
Minor Storm           30/30/25
Major-severe storm    40/55/40