:Product: 20040717RSGA.txt
:Issued: 2004 Jul 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 199 Issued at 2200Z on 17 Jul 2004
IA.  Analysis of Solar Active Regions and Activity from  16/2100Z
to 17/2100Z:  Solar activity was at high levels.  Region 649 (S10E13)
continues to produce M and X-class flare activity.  The largest
flare of the period was an X1/1f impulsive flare that occurred at
17/0757Z.  Region 649 also produced an M2/1n event at 17/1651Z. 
Minor radio bursts accompanied both flares.  LASCO imagery shows
most of the CME plasma structure directed towards the eastern solar
hemisphere.  Region 652 (N05E71) appears fairly ominous in white
light with 750 millionths of sunspot area.  This region has produced
several C-class flares today and remains too close to the solar
eastern limb to determine accurate magnetic structure.  Region 653
(S14E71) was numbered today.
IB.  Solar Activity Forecast:  Solar activity is expected to be at
moderate to high levels.
IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field ranged from quiet to major storm levels.  ACE
data indicates that a shock passed the instrument at approximately
16/2100Z.  This transient is believed to have been the result of the
weak signature, full halo CME activity seen on 13 July.  Higher
latitudes experienced major storm conditions between 17/0000 and
0300Z.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be at predominantly unsettled levels.  There is a chance
for isolated active to minor storm conditions with further transient
activity resulting from the multitude of major flares seen over the
past several days.
III.  Event Probabilities 18 Jul-20 Jul
Class M    80/80/80
Class X    40/40/40
Proton     20/20/20
PCAF       Green
IV.  Penticton 10.7 cm Flux
Observed           17 Jul 149
Predicted   18 Jul-20 Jul  150/150/145
90 Day Mean        17 Jul 098
V.  Geomagnetic A Indices
Observed Afr/Ap 16 Jul  008/012
Estimated Afr/Ap 17 Jul  024/025
Predicted Afr/Ap 18 Jul-20 Jul  012/015-012/015-012/015
VI.  Geomagnetic Activity Probabilities 18 Jul-20 Jul
A.  Middle Latitudes
Active                25/25/25
Minor storm           15/15/15
Major-severe storm    10/10/10
B.  High Latitudes
Active                35/35/35
Minor storm           20/20/20
Major-severe storm    10/10/10