Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 26 July 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 207 Issued at 2200Z on 26 Jul 2013

IA. Analysis of Solar Active Regions and Activity from 25/2100Z to
26/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C2 event observed at
25/2244Z from Region 1800 (S08W46). There are currently 4 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 (27 Jul, 28 Jul, 29 Jul).

IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: 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
623 km/s at 26/0823Z. Total IMF reached 13 nT at 26/0225Z. The maximum
southward component of Bz reached -9 nT at 25/2222Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 289 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (27 Jul), quiet to unsettled
levels on day two (28 Jul) and quiet levels on day three (29 Jul).

III. Event probabilities 27 Jul-29 Jul
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 26 Jul 110
Predicted 27 Jul-29 Jul 105/105/110
90 Day Mean 26 Jul 120

V. Geomagnetic A Indices
Observed Afr/Ap 25 Jul 010/014
Estimated Afr/Ap 26 Jul 013/015
Predicted Afr/Ap 27 Jul-29 Jul 010/012-008/008-004/005

VI. Geomagnetic Activity Probabilities 27 Jul-29 Jul
A. Middle Latitudes
Active 25/15/10
Minor Storm 10/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/25/20
Major-severe storm 35/20/10