Report of Solar Geophysical Activity

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 229 Issued at 2200Z on 17 Aug 2017

IA.  Analysis of Solar Active Regions and Activity from 16/2100Z to
17/2100Z: 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 (18 Aug, 19 Aug) and expected to be very low
with a chance for a C-class flares on day three (20 Aug).

IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic
field has been at quiet to minor storm levels for the past 24 hours.
Solar wind speed reached a peak of 594 km/s at 17/1851Z. Total IMF
reached 13 nT at 17/0733Z. The maximum southward component of Bz reached
-12 nT at 17/0820Z. Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 330 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to minor storm levels on day one (18 Aug), quiet to
active levels on day two (19 Aug) and unsettled to active levels on day
three (20 Aug).

III.  Event probabilities 18 Aug-20 Aug
Class M    10/10/05
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           17 Aug 077
Predicted   18 Aug-20 Aug 078/077/076
90 Day Mean        17 Aug 076

V.  Geomagnetic A Indices
Observed Afr/Ap 16 Aug  005/006
Estimated Afr/Ap 17 Aug  023/033
Predicted Afr/Ap 18 Aug-20 Aug  019/024-015/018-012/016

VI.  Geomagnetic Activity Probabilities 18 Aug-20 Aug
A.  Middle Latitudes
Active                35/30/30
Minor Storm           25/15/15
Major-severe storm    05/01/01
B.  High Latitudes
Active                10/10/10
Minor Storm           20/25/25
Major-severe storm    65/50/50

Radio Events Observed 17 Aug 2017
A.  245 MHz Bursts
Start  End   Peak Flux  Time of Peak  Duration
0059   0059    250          0059        0000  
0109   0109    210          0109        0000  
0324   0324    5500         0324        0000  
0314   0314    120          0314        0000  
0034   0345    870          0034        0191  
B.  245 MHz Noise Storms
Start  End   Peak Flux  Time of Peak
0141   0227    130          0141