Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 17 May 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 137 Issued at 2200Z on 17 May 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 slight chance for a C-class flare on days one, two, and three (18 May, 19 May, 20 May).

IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 561 km/s at 16/2146Z. Total IMF reached 6 nT at 17/0855Z. The maximum southward component of Bz reached -5 nT at 17/0913Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 256 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (18 May), active to major storm levels on day two (19 May) and active to minor storm levels on day three (20 May).

III.  Event probabilities 18 May-20 May
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           17 May 071
Predicted   18 May-20 May 071/071/071
90 Day Mean        17 May 077

V.  Geomagnetic A Indices
Observed Afr/Ap 16 May  010/008
Estimated Afr/Ap 17 May  012/014
Predicted Afr/Ap 18 May-20 May  015/020-031/045-024/030

VI.  Geomagnetic Activity Probabilities 18 May-20 May
A.  Middle Latitudes
Active                35/30/40
Minor Storm           20/35/20
Major-severe storm    05/15/01
B.  High Latitudes
Active                15/15/15
Minor Storm           15/20/20
Major-severe storm    10/20/15