Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 199 Issued at 2200Z on 18 Jul 2023
IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity has been at high levels for the past 24 hours. The largest solar event of the period was a M5 event observed at 18/0006Z from Region 3363 (S21W86). There are currently 8 numbered sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is likely to be moderate with a slight chance for an X-class flare on day one (19 Jul) and expected to be low with a chance for M-class flares and a slight chance for an X-class flare on days two and three (20 Jul, 21 Jul).
IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 556 km/s at 17/2204Z. Total IMF reached 7 nT at 17/2134Z. The maximum southward component of Bz reached -6 nT at 18/0121Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 619 pfu at 18/0615Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 936 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and three (19 Jul, 21 Jul) and quiet to minor storm levels on day two (20 Jul). Protons are expected to cross threshold on day one (19 Jul), are likely to cross threshold on day two (20 Jul) and have a chance of crossing threshold on day three (21 Jul).
III. Event probabilities 19 Jul-21 Jul
Class M 55/45/45
Class X 20/20/15
Proton 95/70/50
PCAF red
IV. Penticton 10.7 cm Flux
Observed 18 Jul 219
Predicted 19 Jul-21 Jul 210/210/210
90 Day Mean 18 Jul 161
V. Geomagnetic A Indices
Observed Afr/Ap 17 Jul 019/023
Estimated Afr/Ap 18 Jul 016/021
Predicted Afr/Ap 19 Jul-21 Jul 010/012-018/028-015/020
VI. Geomagnetic Activity Probabilities 19 Jul-21 Jul
A. Middle Latitudes
Active 30/35/35
Minor Storm 10/30/20
Major-severe storm 01/15/05
B. High Latitudes
Active 25/15/20
Minor Storm 25/25/25
Major-severe storm 20/50/40
space weather
