Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 27 April 2018

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 117 Issued at 2200Z on 27 Apr 2018

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 is currently 1 numbered sunspot region on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be very low on days one, two, and three (28 Apr, 29 Apr, 30 Apr).

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 394 km/s at 27/1304Z. Total IMF reached 8 nT at 27/1452Z. The maximum southward component of Bz reached -7 nT at 27/1433Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 4841 pfu.

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

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

IV.  Penticton 10.7 cm Flux
Observed           27 Apr 069
Predicted   28 Apr-30 Apr 069/069/069
90 Day Mean        27 Apr 070

V.  Geomagnetic A Indices
Observed Afr/Ap 26 Apr  004/005
Estimated Afr/Ap 27 Apr  005/006
Predicted Afr/Ap 28 Apr-30 Apr  006/005-006/005-006/005

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