:Product: 20040719RSGA.txt
:Issued: 2004 Jul 19 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 201 Issued at 2200Z on 19 Jul 2004
IA.  Analysis of Solar Active Regions and Activity from  18/2100Z
to 19/2100Z:  Solar activity decreased to low levels.  Region 649
(S10W13) was limited to C-class flare activity today.  The largest
was a C4/Sf flare that occurred at 19/0533Z.  This region is in
decay and much deterioration has been observed in the delta
structure in the dominant trailing spot.  A second delta spot is
evident just east of the dominate lead spot which has changed little
since yesterday.  The spot area has decreased 140 millionths in
white light observations.  Region 652 (N05E45) was also limited to
low level C-class flare activity although SXI x-ray imagery
indicates a near continuous surging in the northern quadrant of
region continually bleeding off energy and possibly suppressing
major flare activity.  The consensus of white light area coverage
for this region is currently observed at over 1500 millionths with a
well defined intermediate delta spot.  Region 653 (S14E45) has shown
continued growth during the past 24 hours although it has been
fairly quiescent throughout the period.  An eruptive prominence
occurred at 19/0910Z on the west solar limb at S12 which produced a
weak structured CME that does not appear to be Earth directed.  A
second CME was seen shortly afterward on the northwest solar limb
that is believed to be back sided.  No new regions were numbered
today.
IB.  Solar Activity Forecast:  Solar activity is expected to be at
moderate to high levels.  Regions 649 and 652 both remain capable of
producing isolated major flare activity.
IIA.  Geophysical Activity Summary 18/2100Z to 19/2100Z:
The geomagnetic field was at predominantly unsettled levels.  An
active period was observed at the Boulder magnetometer between
19/0300 and 0600Z in conjunction with sustained southward Bz field
values.  A subsequent active period was observed between 19/1500 and
1800Z which was in response to a solar sector boundary crossing.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be at predominantly unsettled levels.  Isolated active
levels are possible with the potential of transient activity on 20
and 21 July due to the recent major flares from Region 649.
III.  Event Probabilities 20 Jul-22 Jul
Class M    65/65/65
Class X    30/30/30
Proton     15/15/15
PCAF       Green
IV.  Penticton 10.7 cm Flux
Observed           19 Jul 170
Predicted   20 Jul-22 Jul  170/165/165
90 Day Mean        19 Jul 098
V.  Geomagnetic A Indices
Observed Afr/Ap 18 Jul  006/009
Estimated Afr/Ap 19 Jul  006/015
Predicted Afr/Ap 20 Jul-22 Jul  010/012-008/008-005/005
VI.  Geomagnetic Activity Probabilities 20 Jul-22 Jul
A.  Middle Latitudes
Active                15/15/10
Minor storm           10/05/05
Major-severe storm    05/01/01
B.  High Latitudes
Active                25/20/15
Minor storm           10/05/05
Major-severe storm    05/01/01