Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 27 May 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 147 Issued at 2200Z on 27 May 2017

IA.  Analysis of Solar Active Regions and Activity from 26/2100Z to 27/2100Z: 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 on days one, two, and three (28 May, 29 May, 30 May).

IIA.  Geophysical Activity Summary 26/2100Z to 27/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 386 km/s at 27/1827Z. Total IMF reached 21 nT at 27/2050Z. The maximum southward component of Bz reached -17 nT at 27/2050Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 13235 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (28 May), quiet to unsettled levels on day two (29 May) and quiet levels on day three (30 May).

III.  Event probabilities 28 May-30 May
Class M    05/05/05
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           27 May 082
Predicted   28 May-30 May 082/080/075
90 Day Mean        27 May 077

V.  Geomagnetic A Indices
Observed Afr/Ap 26 May  003/004
Estimated Afr/Ap 27 May  007/010
Predicted Afr/Ap 28 May-30 May  013/015-007/008-005/005

VI.  Geomagnetic Activity Probabilities 28 May-30 May
A.  Middle Latitudes
Active                25/15/10
Minor Storm           10/05/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/20/15
Major-severe storm    20/20/10