:Product: 0912RSGA.txt
:Issued: 2005 Sep 12 2204 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Environment Center and the U.S. Air Force.
#
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 255 Issued at 2200Z on 12 Sep 2005
IA.  Analysis of Solar Active Regions and Activity from  11/2100Z
to 12/2100Z:  Solar activity was at high levels.  Region 808 (S11E17)
produced four M-class flares. The largest of these was a M6.1/2f
flare at 12/0903 UTC. This flare had an associated tenflare of 980
sfu.  Region 808 has decayed in penumbral area on the eastern and
western most ends of the sunspot region.  Area has decayed to
approximately 840 millionths; however, the region still exhibits a
beta-gamma-delta magnetic configuration.
IB.  Solar Activity Forecast:  Solar activity is expected to be
moderate to high.
IIA.  Geophysical Activity Summary 11/2100Z to 12/2100Z:
The geomagnetic field was at active to major storm levels. A shock
was observed by the ACE spacecraft at approximately 12/0600 UTC.
Solar wind speed at ACE increased to over a thousand km/s; however,
the IMF Bz never went lower than -12 nT. Minor to major storm levels
occurred at all latitudes following the shock. Solar wind speed
gradually declined to near 800 km/s by the end of the period. The
greater than 10 MeV proton event remains in progress, but has now
declined to near 10 pfu. The greater than 2 MeV electron flux at
geosynchronous orbit was at high levels today.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to range from unsettled to major storm levels. Solar wind
speed remains very high and further transient flow is expected on 13
September. Barring any further CME activity from Region 808, the
geomagnetic field should return to unsettled to active periods by 15
September.
III.  Event Probabilities 13 Sep-15 Sep
Class M    80/75/70
Class X    60/50/40
Proton     99/50/40
PCAF       in progress
IV.  Penticton 10.7 cm Flux
Observed           12 Sep 118
Predicted   13 Sep-15 Sep  115/110/110
90 Day Mean        12 Sep 092
V.  Geomagnetic A Indices
Observed Afr/Ap 11 Sep  053/105
Estimated Afr/Ap 12 Sep  045/060
Predicted Afr/Ap 13 Sep-15 Sep  025/035-020/025-015/020
VI.  Geomagnetic Activity Probabilities 13 Sep-15 Sep
A.  Middle Latitudes
Active                35/30/30
Minor storm           20/20/15
Major-severe storm    15/10/05
B.  High Latitudes
Active                20/35/30
Minor storm           35/20/20
Major-severe storm    20/15/10