Joint USAF/NOAA Report of Solar and Geophysical Activity 13 August 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Aug 13 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 225 Issued at 2200Z on 13 Aug 2011
IA. Analysis of Solar Active Regions and Activity from 12/2100Z
to 13/2100Z: Solar activity has been very low. The largest X-ray
event of the past 24 hours was a B1 flare at 13/1431 UTC in Region
1269 (S21W09). All active regions currently on the solar disk are
small and simple.
IB. Solar Activity Forecast: Solar activity is expected to be very
low for the next three days (14-16 August). There is a slight chance
of an isolated C-class X-ray flare.
IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z:
The geomagnetic field was quiet. Solar wind observations from the
NASA ACE spacecraft indicate nominal background conditions with a
solar wind speed of about 320 km/s, density near 4 p/cc, and the
southward component of the IMF (Bz) fluctuating +/- 4 nT around
zero. The greater than 2 MeV electron flux at geosynchronous orbit
was at high levels throughout the period.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled for the next three days (14-16
August) as a co-rotating interaction region followed by a negative
polarity coronal hole high-speed stream become geoeffective.
III. Event Probabilities 14 Aug-16 Aug
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 13 Aug 083
Predicted 14 Aug-16 Aug 082/080/080
90 Day Mean 13 Aug 096
V. Geomagnetic A Indices
Observed Afr/Ap 12 Aug 003/005
Estimated Afr/Ap 13 Aug 004/005
Predicted Afr/Ap 14 Aug-16 Aug 012/012-010/010-010/010
VI. Geomagnetic Activity Probabilities 14 Aug-16 Aug
A. Middle Latitudes
Active 40/30/30
Minor storm 10/10/10
Major-severe storm 01/01/01
B. High Latitudes
Active 40/35/30
Minor storm 15/15/10
Major-severe storm 05/05/05