Joint USAF/NOAA Report of Solar and Geophysical Activity 23 March 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Mar 23 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 082 Issued at 2200Z on 23 Mar 2011
IA. Analysis of Solar Active Regions and Activity from 22/2100Z
to 23/2100Z: Solar activity increased to moderate levels. Region
1176 (S15E58) produced an isolated impulsive M1 flare at 23/0217Z
associated with weak radio emission. It also produced occasional B-
and C-class flares. Region 1176 rotated more fully into view and was
classified as an Eko-type group with a moderately complex beta-gamma
magnetic configuration. Region 1175 (N11W76) was quiet and stable as
it approached the west limb. New Region 1177 (N21E51) was numbered
as a magnetically simple, single-spot Axx-type.
IB. Solar Activity Forecast: Solar activity is expected to be at
mostly low levels during the period (24 – 26 March) with a chance
for an isolated M-class flare from Region 1176.
IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z:
Geomagnetic field activity was at quiet to unsettled levels, with a
brief interval of active levels detected at Boulder at around
23/0700Z. ACE solar wind data indicated the increased activity was
the result of a coronal hole high-speed stream. Solar wind
velocities gradually increased from 358 to 547 km/sec during the
period. IMF Bt increased during the period with a maximum of 11 nT
observed at 23/0714Z. IMF Bz was variable during the period and
ranged from -6 to +8 nT.
IIB. Geophysical Activity Forecast: Geomagnetic field activity is
expected to be at quiet to unsettled levels during days 1 – 2 (24 –
25 Mar) with a chance for brief active levels as coronal hole
effects persist. Activity is expected to decrease to quiet levels on
day 3 (26 March) as coronal hole effects subside.
III. Event Probabilities 24 Mar-26 Mar
Class M 30/30/30
Class X 05/05/05
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 23 Mar 105
Predicted 24 Mar-26 Mar 105/105/110
90 Day Mean 23 Mar 095
V. Geomagnetic A Indices
Observed Afr/Ap 22 Mar 005/006
Estimated Afr/Ap 23 Mar 008/008
Predicted Afr/Ap 24 Mar-26 Mar 008/008-008/008-005/005
VI. Geomagnetic Activity Probabilities 24 Mar-26 Mar
A. Middle Latitudes
Active 15/15/10
Minor storm 05/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 20/20/15
Minor storm 10/10/01
Major-severe storm 01/01/01