:Product: 20040917RSGA.txt
:Issued: 2004 Sep 17 2200 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 261 Issued at 2200Z on 17 Sep 2004
IA.  Analysis of Solar Active Regions and Activity from  16/2100Z
to 17/2100Z:  Solar activity has been very low.  X-ray flux has
remained at background levels.  Surging was observed from Region 673
(S13E51), and the region grew slightly over the period to 320
millionths in white light.  No new regions were numbered today.
IB.  Solar Activity Forecast:  Solar activity is expected to be very
low to low.  Regions 672 (N05W29) and 673 are capable of C-class
flares.
IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field was at quiet to minor storm levels, most likely
caused by the increased solar wind from a geoeffective coronal hole.
Solar wind speed at ACE began to diminsh around 0900 UTC and was at
approximately 450 km/s at the end of the period.  The greater than 2
MeV electron flux at geosynchronous orbit reached high levels today.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be quiet to unsettled.
III.  Event Probabilities 18 Sep-20 Sep
Class M    20/20/20
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           17 Sep 105
Predicted   18 Sep-20 Sep  105/105/100
90 Day Mean        17 Sep 111
V.  Geomagnetic A Indices
Observed Afr/Ap 16 Sep  014/017
Estimated Afr/Ap 17 Sep  015/020
Predicted Afr/Ap 18 Sep-20 Sep  010/015-010/012-008/012
VI.  Geomagnetic Activity Probabilities 18 Sep-20 Sep
A.  Middle Latitudes
Active                30/30/30
Minor storm           05/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                40/35/30
Minor storm           25/25/20
Major-severe storm    15/10/10