Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 August 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 230 Issued at 2200Z on 18 Aug 2017

IA.  Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: 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 with a chance for a C-class flares and a slight chance for an M-class flare on days one and two (19 Aug, 20 Aug) and expected to be very low with a chance for a C-class flares on day three (21 Aug).

IIA.  Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 685 km/s at 18/0659Z. Total IMF reached 8 nT at 18/0101Z. The maximum southward component of Bz reached -7 nT at 18/0025Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1170 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one, two, and three (19 Aug, 20 Aug, 21 Aug).

III.  Event probabilities 19 Aug-21 Aug
Class M    10/10/05
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           18 Aug 080
Predicted   19 Aug-21 Aug 082/084/085
90 Day Mean        18 Aug 076

V.  Geomagnetic A Indices
Observed Afr/Ap 17 Aug  020/028
Estimated Afr/Ap 18 Aug  016/022
Predicted Afr/Ap 19 Aug-21 Aug  015/018-012/015-011/012

VI.  Geomagnetic Activity Probabilities 19 Aug-21 Aug
A.  Middle Latitudes
Active                30/25/15
Minor Storm           10/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                10/15/15
Minor Storm           30/30/30
Major-severe storm    45/40/25