:Product: 0517RSGA.txt
:Issued: 2011 May 17 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 137 Issued at 2200Z on 17 May 2011
IA.  Analysis of Solar Active Regions and Activity from  16/2100Z
to 17/2100Z:  Solar activity was very low during the past 24 hours.
Regions 1208 (N09W78) and 1214 (S24W24) produced several B-class
events. All other regions on the disk remained relatively quiet and
stable. A filament erupted near N13W07 and an associated CME became
visible on STEREO COR2 imagery at 17/0709Z. The CME was well above
the ecliptic plane and is not expected to be geoeffective.
IB.  Solar Activity Forecast:  Solar activity is expected to be very
low with a chance for C-class activity for the next three days
(18-20 May).
IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field was mostly quiet during the past 24 hours.
Solar wind velocities gradually decreased from approximately 620
km/s to 540 km/s indicating the effects from the coronal hole
high-speed stream (CH HSS) that has been influencing the field for
the past few days are beginning to subside.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be mostly quiet for the next three days (18-20 May).
III.  Event Probabilities 18 May-20 May
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           17 May 092
Predicted   18 May-20 May  092/095/095
90 Day Mean        17 May 109
V.  Geomagnetic A Indices
Observed Afr/Ap 16 May  010/012
Estimated Afr/Ap 17 May  008/008
Predicted Afr/Ap 18 May-20 May  005/005-005/005-005/005
VI.  Geomagnetic Activity Probabilities 18 May-20 May
A.  Middle Latitudes
Active                10/05/05
Minor storm           01/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/05/05
Minor storm           01/01/01
Major-severe storm    01/01/01