Joint USAF/NOAA Report of Solar and Geophysical Activity 10 May 2012

:Product: Report of Solar-Geophysical Activity
:Issued: 2012 May 10 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 131 Issued at 2200Z on 10 May 2012
IA. Analysis of Solar Active Regions and Activity from 09/2100Z
to 10/2100Z: Solar activity has been at high levels for the past 24
hours with multiple M-class solar flares observed. Region 1476
(N12E08) was responsible for almost all of the activity with 3
M-class events observed, the largest being a M5/2b event at
10/0418Z. Associated with these events, were discrete frequency
radio bursts, Tenflares, and even a Type IV radio sweep. Region 1476
has shown mixed growth and shear effects across the polarities as it
continues to evolve. A weak Earth directed CME was observed in
STEREO COR2 A and B imagery early in the period. Analysis and
current models show this CME joining the current coronal hole high
speed stream (CH HSS). Region 1477 (S22E47) was split into two
regions today as SDO magnetogram data indicated the leader and
follower sunspot groups were actually two magnetic bipoles. Leader
group is Region 1477 and follower group is now Region 1478 (S24E55).
IB. Solar Activity Forecast: Solar activity is expected to be at
moderate levels with a slight chance for X-class events for the next
three days (11 – 13 May) as Region 1476 continues to grow and
evolve.
IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z:
The geomagnetic field has been at quiet to active levels for the past
24 hours with an isolated minor storm period observed at high
latitudes. Solar wind measurements, as observed by the ACE
spacecraft, showed a continued increase in solar wind speeds to
around 620 km/s, a drop off in solar wind density, and the total IMF
began to stabilize around 5 nT. These characteristics are indicative
of a CH HSS. The greater than 2 MeV electron flux at geosynchronous
orbit reached high levels during the period.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels with a chance for active
periods for the next three days (11 – 13 May). The increased
activity is due to both the continued CH HSS effects and three weak,
slow moving CME’s intertwined within.
III. Event Probabilities 11 May-13 May
Class M 75/75/75
Class X 20/20/20
Proton 10/10/10
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 10 May 131
Predicted 11 May-13 May 130/130/130
90 Day Mean 10 May 113
V. Geomagnetic A Indices
Observed Afr/Ap 09 May 019/025
Estimated Afr/Ap 10 May 010/010
Predicted Afr/Ap 11 May-13 May 012/012-010/012-006/010
VI. Geomagnetic Activity Probabilities 11 May-13 May
A. Middle Latitudes
Active 20/20/15
Minor storm 05/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 40/40/30
Minor storm 10/10/10
Major-severe storm 01/01/01