Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 4 May 2019

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 124 Issued at 2200Z on 04 May 2019

IA. Analysis of Solar Active Regions and Activity from 03/2100Z to 04/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 03/2331Z from Region 2740 (N12E80). There is currently 1 numbered sunspot region 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, two, and three (05 May, 06 May, 07 May).

IIA. Geophysical Activity Summary 03/2100Z to 04/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 526 km/s at 04/1709Z. Total IMF reached 11 nT at 04/0048Z. The maximum southward component of Bz reached -6 nT at 04/0508Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 4753 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (05 May) and quiet to active levels on days two and three (06 May, 07 May).

III. Event probabilities 05 May-07 May
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 04 May 072
Predicted 05 May-07 May 072/074/076
90 Day Mean 04 May 072

V. Geomagnetic A Indices
Observed Afr/Ap 03 May 008/007
Estimated Afr/Ap 04 May 011/012
Predicted Afr/Ap 05 May-07 May 007/008-010/012-012/014

VI. Geomagnetic Activity Probabilities 05 May-07 May
A. Middle Latitudes
Active 20/30/30
Minor Storm 05/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 20/15/15
Minor Storm 30/35/35
Major-severe storm 25/30/30