Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 262 Issued at 2200Z on 19 Sep 2023
IA. Analysis of Solar Active Regions and Activity from 18/2100Z to 19/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M4 event observed at 19/2014Z from Region 3435 (N09E42). There are currently 10 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 (20 Sep, 21 Sep, 22 Sep).
IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic field has been at active to severe storm levels for the past 24 hours. Solar wind speed reached a peak of 698 km/s at 19/0833Z. Total IMF reached 17 nT at 18/2204Z. The maximum southward component of Bz reached -14 nT at 18/2149Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2068 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and three (20 Sep, 22 Sep) and quiet to unsettled levels on day two (21 Sep).
III. Event probabilities 20 Sep-22 Sep
Class M 40/40/40
Class X 01/05/05
Proton 01/05/05
PCAF green
IV. Penticton 10.7 cm Flux
Observed 19 Sep 166
Predicted 20 Sep-22 Sep 162/160/155
90 Day Mean 19 Sep 162
V. Geomagnetic A Indices
Observed Afr/Ap 18 Sep 021/041
Estimated Afr/Ap 19 Sep 037/050
Predicted Afr/Ap 20 Sep-22 Sep 014/016-008/008-011/015
VI. Geomagnetic Activity Probabilities 20 Sep-22 Sep
A. Middle Latitudes
Active 30/20/35
Minor Storm 10/05/15
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/10
Minor Storm 20/20/30
Major-severe storm 20/20/50
space weather
