Joint USAF/NOAA Report of Solar and Geophysical Activity 24 July 2012

:Product: Report of Solar-Geophysical Activity
:Issued: 2012 Jul 24 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 24 Jul 2012
IA. Analysis of Solar Active Regions and Activity from 23/2100Z
to 24/2100Z: Solar activity was low. New Region 1530 (S19E68) was
responsible for multiple low level C-class flares. The largest was
a C4/Sf at 24/1905Z. SDO and STEREO-B EUVI 195 imagery show
brightening behind the northeast and southeast limbs, suggesting the
presence of more active regions yet to rotate onto the visible disk.
IB. Solar Activity Forecast: Solar activity is expected to be at
low levels.
IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z:
The geomagnetic field was at quiet to unsettled levels with an
isolated minor storm period at high latitudes from 24/1200 – 1500Z.
Solar wind measurements at the ACE spacecraft showed an increase in
solar wind speed from approximately 450 km/s to 580 km/s by 24/0830Z
before decreasing to 500 km/s by the end of the period. This is
likely due to the influence of a geoeffective coronal hole high
speed stream. The greater than 10 MeV proton event at
geosynchronous orbit that began at 23/1545Z, reached a maximum flux
of 12 pfu at 23/2145Z and continued to fluctuate near the 10 pfu
threshold. 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 be at quiet to unsettled levels with a slight chance for
active periods on day 1 (25 July) due to persistent effects from the
coronal hole high speed stream. Mostly quiet conditions are
expected for days 2 – 3 (26 – 27 July).
III. Event Probabilities 25 Jul-27 Jul
Class M 05/05/05
Class X 01/01/01
Proton 30/01/01
PCAF yellow
IV. Penticton 10.7 cm Flux
Observed 24 Jul 102
Predicted 25 Jul-27 Jul 110/115/115
90 Day Mean 24 Jul 126
V. Geomagnetic A Indices
Observed Afr/Ap 23 Jul 008/012
Estimated Afr/Ap 24 Jul 009/010
Predicted Afr/Ap 25 Jul-27 Jul 008/008-006/005-006/005
VI. Geomagnetic Activity Probabilities 25 Jul-27 Jul
A. Middle Latitudes
Active 10/05/05
Minor storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor storm 15/10/10
Major-severe storm 05/05/05