Joint USAF/NOAA Report of Solar and Geophysical Activity 4 August 2011
:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Aug 04 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 216 Issued at 2200Z on 04 Aug 2011
IA. Analysis of Solar Active Regions and Activity from 03/2100Z
to 04/2100Z: Solar activity was high. Region 1261 (N15W49) produced
a M9/2B at 0357Z. This event had associated Type II and Type IV
radio sweeps and a CME with an approximate speed of 2100 km/s in
STEREO A COR-2 imagery. Region 1261 has appeared to decay in the
southern most trailing spots and is classified as a Dai spot class
with a Beta-Gamma-Delta magnetic classification. Region 1263
(N17W18) has been relatively stable, only managing a few C-class
flares. Region 1263 is classified as a Dki spot class with a
Beta-Gamma-Delta magnetic classification. New Region 1266 (N18E38)
was numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be
moderate to high. Further M-class activity is expected from Region
1261. Region 1263 has the potential for M-class activity as well.
There continues to be a chance for isolated major flare activity.
IIA. Geophysical Activity Summary 03/2100Z to 04/2100Z:
The geomagnetic field was quiet. The greater than 10 MeV proton flux
at geosynchronous orbit crossed the 10 PFU threshold at 0635Z and
reached a peak of 80.1 PFU at 1030Z. The greater than 100 MeV
proton flux at geosynchronous orbit crossed the 1 PFU threshold at
0510Z and reached a peak of 1.8 PFU at 0740Z. This proton event was
associated with the M9 flare at 0357Z.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at minor to major storm levels with a chance for
severe storm periods as the effects of three CME’s are expected to
impact the Earth’s geomagnetic field early on 05 August. Active to
minor storm levels are expected on 06 August. Unsettled to active
levels are expected on 07 August.
III. Event Probabilities 05 Aug-07 Aug
Class M 75/75/65
Class X 15/15/10
Proton 95/50/30
PCAF red
IV. Penticton 10.7 cm Flux
Observed 04 Aug 116
Predicted 05 Aug-07 Aug 115/110/110
90 Day Mean 04 Aug 096
V. Geomagnetic A Indices
Observed Afr/Ap 03 Aug 003/003
Estimated Afr/Ap 04 Aug 005/005
Predicted Afr/Ap 05 Aug-07 Aug 050/050-030/030-015/020
VI. Geomagnetic Activity Probabilities 05 Aug-07 Aug
A. Middle Latitudes
Active 15/30/25
Minor storm 35/30/15
Major-severe storm 50/20/05
B. High Latitudes
Active 15/30/25
Minor storm 30/30/20
Major-severe storm 55/30/15
