Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 29 April 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 119 Issued at 2200Z on 29 Apr 2021

IA. Analysis of Solar Active Regions and Activity from 28/2100Z to 29/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 3 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 and two (30 Apr, 01 May) and expected to be very low on day three (02 May).

IIA. Geophysical Activity Summary 28/2100Z to 29/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 363 km/s at 29/1910Z. Total IMF reached 8 nT at 29/1948Z. The maximum southward component of Bz reached -4 nT at 29/1246Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1076 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and two (30 Apr, 01 May) and unsettled levels on day three (02 May).

III. Event probabilities 30 Apr-02 May
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 29 Apr 077
Predicted 30 Apr-02 May 077/075/072
90 Day Mean 29 Apr 076

V. Geomagnetic A Indices
Observed Afr/Ap 28 Apr 004/004
Estimated Afr/Ap 29 Apr 006/006
Predicted Afr/Ap 30 Apr-02 May 007/008-006/008-011/015

VI. Geomagnetic Activity Probabilities 30 Apr-02 May
A. Middle Latitudes
Active 20/25/35
Minor Storm 10/10/10
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/25/30
Major-severe storm 30/40/45