Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 25 July 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 206 Issued at 2200Z on 25 Jul 2013

IA. Analysis of Solar Active Regions and Activity from 24/2100Z to
25/2100Z: 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
24/2143Z from Region 1800 (S09W32). There are currently 5 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 and a slight chance for an M-class
flare on days one, two, and three (26 Jul, 27 Jul, 28 Jul).

IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: 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
498 km/s at 25/2024Z. Total IMF reached 15 nT at 25/1946Z. The maximum
southward component of Bz reached -11 nT at 25/1946Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 2586 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to minor storm levels on day one (26 Jul), quiet to
active levels on day two (27 Jul) and quiet to unsettled levels on day
three (28 Jul).

III. Event probabilities 26 Jul-28 Jul
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 25 Jul 107
Predicted 26 Jul-28 Jul 105/105/110
90 Day Mean 25 Jul 121

V. Geomagnetic A Indices
Observed Afr/Ap 24 Jul 006/005
Estimated Afr/Ap 25 Jul 004/004
Predicted Afr/Ap 26 Jul-28 Jul 013/018-010/012-008/008

VI. Geomagnetic Activity Probabilities 26 Jul-28 Jul
A. Middle Latitudes
Active 40/25/15
Minor Storm 15/10/05
Major-severe storm 01/01/01
B. High Latitudes
Active 10/15/15
Minor Storm 25/25/25
Major-severe storm 55/35/20