Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 28 April 2016

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 119 Issued at 2200Z on 28 Apr 2016

IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: 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 28/1251Z from Region 2535 (N07E16). There are currently 6 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares on days one, two, and three (29 Apr, 30 Apr, 01 May).

IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 498 km/s at 28/0303Z. Total IMF reached 5 nT at 28/0814Z. The maximum southward component of Bz reached -3 nT at 28/1247Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 347 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (29 Apr), unsettled to minor storm levels on day two (30 Apr) and unsettled to active levels on day three (01 May).

III. Event probabilities 29 Apr-01 May
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 28 Apr 095
Predicted 29 Apr-01 May 095/095/092
90 Day Mean 28 Apr 096

V. Geomagnetic A Indices
Observed Afr/Ap 27 Apr 011/010
Estimated Afr/Ap 28 Apr 006/007
Predicted Afr/Ap 29 Apr-01 May 012/014-018/026-017/020

VI. Geomagnetic Activity Probabilities 29 Apr-01 May
A. Middle Latitudes
Active 40/35/40
Minor Storm 20/20/20
Major-severe storm 05/05/05
B. High Latitudes
Active 10/10/10
Minor Storm 25/30/25
Major-severe storm 60/55/60