Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 30 April 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 120 Issued at 2200Z on 30 Apr 2021

IA. Analysis of Solar Active Regions and Activity from 29/2100Z to 30/2100Z: 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 (01 May, 02 May) and expected to be very low on day three (03 May).

IIA. Geophysical Activity Summary 29/2100Z to 30/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speedreached a peak of 358 km/s at 30/1424Z. Total IMF reached 9 nT at 30/0344Z. The maximum southward component of Bz reached -6 nT at 30/1522Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1836 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (01 May) and quiet to active levels on days two and three (02 May, 03 May).

III. Event probabilities 01 May-03 May
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 30 Apr 073
Predicted 01 May-03 May 072/070/070
90 Day Mean 30 Apr 076

V. Geomagnetic A Indices
Observed Afr/Ap 29 Apr 005/005
Estimated Afr/Ap 30 Apr 006/007
Predicted Afr/Ap 01 May-03 May 006/008-014/015-011/012

VI. Geomagnetic Activity Probabilities 01 May-03 May
A. Middle Latitudes
Active 25/35/25
Minor Storm 10/15/10
Major-severe storm 01/01/01
B. High Latitudes
Active 15/10/15
Minor Storm 25/25/30
Major-severe storm 35/50/40