Joint USAF/NOAA Report of Solar and Geophysical Activity 25 July 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Jul 25 2200 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Weather Prediction Center and the U.S. Air Force.
#
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 206 Issued at 2200Z on 25 Jul 2011
IA. Analysis of Solar Active Regions and Activity from 24/2100Z
to 25/2100Z: Solar activity was very low during the past 24 hours. A
B7 x-ray event was observed at 25/1628Z from Region 1260 (N20E58).
IB. Solar Activity Forecast: Solar activity is expected to be very
low to low for the next three days (25-27 July). Region 1260 is most
likely region for C-class events.
IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z:
The geomagnetic field has been quiet to unsettled. Solar wind
velocities observed at the ACE spacecraft indicated the onset of a
coronal hole high speed stream at about 24/2200Z. Wind speed reached
650 km/s during the period. The greater than 2 MeV electron flux at
geosynchronous orbit reached high levels during the period.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to predominately quiet to unsettled with a slight chance
for isolated active conditions on day one (26 July). Day two (27
July) is expected to be predominately quiet. Day three (28 July) is
expected to be quiet to unsettled with a slight chance for isolated
active periods, with the expected arrival of a recurrent coronal
hole high speed stream late in the period.
III. Event Probabilities 26 Jul-28 Jul
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 25 Jul 087
Predicted 26 Jul-28 Jul 084/086/086
90 Day Mean 25 Jul 095
V. Geomagnetic A Indices
Observed Afr/Ap 24 Jul 003/004
Estimated Afr/Ap 25 Jul 011/012
Predicted Afr/Ap 26 Jul-28 Jul 008/010-005/005-010/012
VI. Geomagnetic Activity Probabilities 26 Jul-28 Jul
A. Middle Latitudes
Active 15/05/15
Minor storm 05/01/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/05/15
Minor storm 05/01/10
Major-severe storm 01/01/01