Joint USAF/NOAA Report of Solar and Geophysical Activity 8 August 2012

:Product: Report of Solar-Geophysical Activity
:Issued: 2012 Aug 08 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 221 Issued at 2200Z on 08 Aug 2012
IA. Analysis of Solar Active Regions and Activity from 07/2100Z
to 08/2100Z: Solar activity was low. Region 1542 (S14E50) remained
the most active region on the solar disk, producing seven C-class
flares. The largest of these flares was a C4/Sf flare that occurred
at 08/1132Z. A large portion of a filament erupted from the
southwest quadrant beginning around 08/0200Z. A slow coronal mass
ejection (CME) (estimated plane-of-sky speed 346 km/s) was first
observed off the west limb in SOHO/LASCO C2 imagery at 08/0612Z and
was likely associated with the filament eruption. The bulk of the
CME material did not appear to be Earth-directed.
IB. Solar Activity Forecast: Solar activity is expected to be low
with a slight chance for an isolated M-class flare.
IIA. Geophysical Activity Summary 07/2100Z to 08/2100Z:
The geomagnetic field was quiet to unsettled with an active period
from 08/0000-0300Z. Indications of a solar sector boundary crossing
were evident on the ACE spacecraft as sustained southward IMF Bz and
enhanced IMF Bt occurred prior to the active period. ACE EPAM data
indicated the beginning of a slow rise in energetic particles at
approximately 08/1200Z. This rise is likely associated with the
anticipated glancing blow from the 04 Aug CME.
IIB. Geophysical Activity Forecast: Geomagnetic activity is
expected to be quiet to unsettled with a slight chance for isolated
active to minor storm periods early on day one (09 Aug). Activity
should return to quiet to unsettled late in the day as effects of
the CME wane. Days two and three (10 and 11 Aug) are expected to be
at predominately quiet levels.
III. Event Probabilities 09 Aug-11 Aug
Class M 15/15/15
Class X 01/01/01
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 08 Aug 133
Predicted 09 Aug-11 Aug 130/130/125
90 Day Mean 08 Aug 128
V. Geomagnetic A Indices
Observed Afr/Ap 07 Aug 008/008
Estimated Afr/Ap 08 Aug 009/010
Predicted Afr/Ap 09 Aug-11 Aug 011/010-006/005-006/005
VI. Geomagnetic Activity Probabilities 09 Aug-11 Aug
A. Middle Latitudes
Active 20/05/05
Minor storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor storm 30/15/15
Major-severe storm 25/05/05