Joint USAF/NOAA Report of Solar and Geophysical Activity 17 May 2011

:Product: Report of Solar-Geophysical Activity
: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