Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 22 August 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 234 Issued at 2200Z on 22 Aug 2017

IA.  Analysis of Solar Active Regions and Activity from 21/2100Z to 22/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 22/1750Z from Region 2671 (N10W31). There are currently 2 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is likely to be low with a slight chance for an M-class flare on days one, two, and three (23 Aug, 24 Aug, 25 Aug).

IIA.  Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic field has been at quiet to major storm levels for the past 24 hours. Solar wind speed reached a peak of 684 km/s at 22/0656Z. Total IMF reached 9 nT at 22/0149Z. The maximum southward component of Bz reached -9 nT at 22/0149Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 31128 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (23 Aug), quiet to unsettled levels on day two (24 Aug) and quiet levels on day three (25 Aug).

III.  Event probabilities 23 Aug-25 Aug
Class M    15/15/15
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           22 Aug 090
Predicted   23 Aug-25 Aug 090/090/090
90 Day Mean        22 Aug 076

V.  Geomagnetic A Indices
Observed Afr/Ap 21 Aug  013/011
Estimated Afr/Ap 22 Aug  018/023
Predicted Afr/Ap 23 Aug-25 Aug  010/012-007/008-006/005

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