Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 23 September 2015

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 266 Issued at 2200Z on 23 Sep 2015

IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C3 event observed at 23/1857Z from Region 2422 (S20E36). There are currently 6 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares on days one, two, and three (24 Sep, 25 Sep, 26 Sep).

IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 574 km/s at 23/0640Z. Total IMF reached 15 nT at 23/1359Z. The maximum southward component of Bz reached -8 nT at 23/1559Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 531 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (24 Sep) and quiet to active levels on days two and three (25 Sep, 26 Sep).

III. Event probabilities 24 Sep-26 Sep
Class M 30/30/30
Class X 05/05/05
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 23 Sep 111
Predicted 24 Sep-26 Sep 115/120/120
90 Day Mean 23 Sep 103

V. Geomagnetic A Indices
Observed Afr/Ap 22 Sep 008/011
Estimated Afr/Ap 23 Sep 010/012
Predicted Afr/Ap 24 Sep-26 Sep 007/008-013/015-013/015

VI. Geomagnetic Activity Probabilities 24 Sep-26 Sep
A. Middle Latitudes
Active 10/30/30
Minor Storm 01/10/10
Major-severe storm 01/01/01
B. High Latitudes
Active 20/15/15
Minor Storm 25/30/30
Major-severe storm 20/40/40