Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 20 April 2019

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 110 Issued at 2200Z on 20 Apr 2019

IA.  Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: 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 on days one, two, and three (21 Apr, 22 Apr, 23 Apr).

IIA.  Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 363 km/s at 20/1956Z. Total IMF reached 6 nT at 19/2114Z. The maximum southward component of Bz reached -4 nT at 20/1903Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 406 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one and two (21 Apr, 22 Apr) and quiet to unsettled levels on day three (23 Apr).

III.  Event probabilities 21 Apr-23 Apr
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           20 Apr 070
Predicted   21 Apr-23 Apr 070/070/070
90 Day Mean        20 Apr 072

V.  Geomagnetic A Indices
Observed Afr/Ap 19 Apr  004/005
Estimated Afr/Ap 20 Apr  005/005
Predicted Afr/Ap 21 Apr-23 Apr  006/005-006/005-007/008

VI.  Geomagnetic Activity Probabilities 21 Apr-23 Apr
A.  Middle Latitudes
Active                15/10/20
Minor Storm           01/01/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/20
Minor Storm           20/20/30
Major-severe storm    15/20/20