:Product: 0818RSGA.txt
:Issued: 2006 Aug 18 2203 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 230 Issued at 2200Z on 18 Aug 2006
IA.  Analysis of Solar Active Regions and Activity from  17/2100Z
to 18/2100Z:  Solar activity was very low during the past 24 hours. 
Region 904 (S13W42) produced a couple of B-class flares today.  This
region continues to be large, but has lost some of its magnetic
complexity in the trailing spots.
IB.  Solar Activity Forecast:  Solar activity is expected to be very
low to low, with just a slight chance for an isolated M-class flare
from Region 904.
IIA.  Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field was quiet to active during the past 24 hours. 
An active period was observed between 18/0300Z - 18/0600Z.  A weak
shock was observed by ACE at approximately 18/1550Z.  Following the
shock, the solar wind speed at ACE increased from approximately 360
km/sec to about 420 km/sec.  However, the IMF remained predominantly
northward.  There was a 5 nT sudden impulse observed at the Boulder
magnetometer at 18/1644Z.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be at active to minor storm levels, with possible
isolated major storm conditions on 19 August, due to the full halo
CME observed on 16 August.  Unsettled to active levels are expected
on 20 August, due to a coronal hole moving into a geoeffective
position.  Quiet to unsettled conditions should return on 21 August.
III.  Event Probabilities 19 Aug-21 Aug
Class M    10/10/10
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           18 Aug 089
Predicted   19 Aug-21 Aug  090/090/090
90 Day Mean        18 Aug 077
V.  Geomagnetic A Indices
Observed Afr/Ap 17 Aug  004/005
Estimated Afr/Ap 18 Aug  010/010
Predicted Afr/Ap 19 Aug-21 Aug  025/025-015/015-008/010
VI.  Geomagnetic Activity Probabilities 19 Aug-21 Aug
A.  Middle Latitudes
Active                35/30/20
Minor storm           20/15/10
Major-severe storm    10/05/01
B.  High Latitudes
Active                35/30/25
Minor storm           25/20/10
Major-severe storm    15/10/01