Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 27 July 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 208 Issued at 2200Z on 27 Jul 2013

IA. Analysis of Solar Active Regions and Activity from 26/2100Z to
27/2100Z: 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
26/2149Z from Region 1800 (S08W60). 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 C-class flares and a slight chance for an M-class
flare on days one, two, and three (28 Jul, 29 Jul, 30 Jul).

IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed, as measured by the ACE spacecraft, reached a peak speed of
553 km/s at 26/2141Z. Total IMF reached 7 nT at 27/1628Z. The maximum
southward component of Bz reached -6 nT at 27/1606Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 1430 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on day one (28 Jul) and quiet levels
on days two and three (29 Jul, 30 Jul).

III. Event probabilities 28 Jul-30 Jul
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 27 Jul 108
Predicted 28 Jul-30 Jul 105/110/115
90 Day Mean 27 Jul 120

V. Geomagnetic A Indices
Observed Afr/Ap 26 Jul 023/014
Estimated Afr/Ap 27 Jul 010/011
Predicted Afr/Ap 28 Jul-30 Jul 008/008-005/005-004/005

VI. Geomagnetic Activity Probabilities 28 Jul-30 Jul
A. Middle Latitudes
Active 15/10/10
Minor Storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/20/20
Major-severe storm 20/10/10