Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 28 August 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 240 Issued at 2200Z on 28 Aug 2017

IA.  Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: Solar activity has been at very low levels for the past 24 hours. There is currently 1 numbered sunspot region on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares and a slight chance for an M-class flare on days one, two, and three (29 Aug, 30 Aug, 31 Aug).

IIA.  Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 395 km/s at 28/1839Z. Total IMF reached 8 nT at 28/1801Z. The maximum southward component of Bz reached -7 nT at 28/1757Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 409 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (29 Aug), quiet to active levels on day two (30 Aug) and active to minor storm levels on day three (31 Aug).

III.  Event probabilities 29 Aug-31 Aug
Class M    10/10/10
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           28 Aug 082
Predicted   29 Aug-31 Aug 082/084/084
90 Day Mean        28 Aug 076

V.  Geomagnetic A Indices
Observed Afr/Ap 27 Aug  006/009
Estimated Afr/Ap 28 Aug  004/005
Predicted Afr/Ap 29 Aug-31 Aug  007/008-012/015-024/030

VI.  Geomagnetic Activity Probabilities 29 Aug-31 Aug
A.  Middle Latitudes
Active                10/30/35
Minor Storm           01/10/30
Major-severe storm    01/01/05
B.  High Latitudes
Active                15/15/15
Minor Storm           25/20/20
Major-severe storm    10/20/30