:Product: 0518RSGA.txt
:Issued: 2011 May 18 2200 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Weather Prediction Center and the U.S. Air Force.
#
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 138 Issued at 2200Z on 18 May 2011
IA.  Analysis of Solar Active Regions and Activity from  17/2100Z
to 18/2100Z:  Solar activity has been low for the last 24 hours. New
Region 1218 (S16E66) was numbered today and produced a C1 event at
18/1259Z. Region 1208 (N09W90) produced a long duration C2 event at
18/1830Z just as it was rotating around the west limb. All other
regions on the disk remained relatively quiet and stable.
IB.  Solar Activity Forecast:  Solar activity is expected to remain
very low with a chance for C-class activity for the next three days
(19-21 May) as new Region 1218 continues to develop.
IIA.  Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field has been mostly quiet for the last 24 hours.
Solar wind at ACE showed a decrease from approximately 550 km/s to
450 km/s during the period as effects from the coronal hole high
speed stream subside.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be quiet for the next three days (19-21 May) as the
solar wind returns to background levels.
III.  Event Probabilities 19 May-21 May
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           18 May 091
Predicted   19 May-21 May  095/095/095
90 Day Mean        18 May 109
V.  Geomagnetic A Indices
Observed Afr/Ap 17 May  008/010
Estimated Afr/Ap 18 May  004/005
Predicted Afr/Ap 19 May-21 May  005/005-005/005-005/005
VI.  Geomagnetic Activity Probabilities 19 May-21 May
A.  Middle Latitudes
Active                05/05/05
Minor storm           01/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                05/05/05
Minor storm           01/01/01
Major-severe storm    01/01/01