Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 April 2019

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 111 Issued at 2200Z on 21 Apr 2019

IA.  Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 0 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be very low on days one, two, and three (22 Apr, 23 Apr, 24 Apr).

IIA.  Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 381 km/s at 20/2341Z. Total IMF reached 6 nT at 21/1838Z. The maximum southward component of Bz reached -3 nT at 20/2338Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 221 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (22 Apr) and quiet to unsettled levels on days two and three (23 Apr, 24 Apr).

III.  Event probabilities 22 Apr-24 Apr
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           21 Apr 069
Predicted   22 Apr-24 Apr 069/068/068
90 Day Mean        21 Apr 072

V.  Geomagnetic A Indices
Observed Afr/Ap 20 Apr  004/004
Estimated Afr/Ap 21 Apr  005/005
Predicted Afr/Ap 22 Apr-24 Apr  006/005-007/008-008/008

VI.  Geomagnetic Activity Probabilities 22 Apr-24 Apr
A.  Middle Latitudes
Active                10/25/25
Minor Storm           01/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/20/20
Minor Storm           20/35/35
Major-severe storm    20/25/25