Joint USAF/NOAA Report of Solar and Geophysical Activity 9 March 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Mar 09 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 068 Issued at 2200Z on 09 Mar 2011
IA. Analysis of Solar Active Regions and Activity from 08/2100Z
to 09/2100Z: Solar activity was moderate. Two M1 x-ray flares were
observed from Region 1166 (N09W12) which was an Ekc spot group with
a Beta-Gamma-Delta magnetic classification. The area of this region
and the number of spots increased over the last 24 hours. Region
1169 (N20E18) also grew in area and number of spots over the past 24
hours, ending the period as an Esc type spot group with a Beta-Gamma
magnetic classification. The remaining regions were either small
and magnetically simple (Region 1170) or decaying (Region 1164) and
rotating off the visible disk.
IB. Solar Activity Forecast: Solar activity is expected to remain
moderate for day 1 (10 March) with a chance for M-class activity
from Region 1166 or Region 1169.
IIA. Geophysical Activity Summary 08/2100Z to 09/2100Z:
The geomagnetic field was quiet. The greater than 10 MeV proton flux
remained above the 10 pfu threshold throughout the past 24 hours.
Solar wind speed measured at the STEREO-A spacecraft jumped from
approximately 650 km/s to 870 km/s near 09/0700Z. This jump was
accompanied by southward Bz to -20nT. These observations were
consistent with a shock passage from the CME that originated on
07/2012Z. 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 unsettled to active, with isolated minor storm
periods possible at high latitudes on day one (10 March), and
primarily unsettled conditions on days two and three (11-12 March).
The CME from 07 March is expected to arrive mid-day on 10 March,
leading to the elevated activity.
III. Event Probabilities 10 Mar-12 Mar
Class M 50/40/30
Class X 05/05/01
Proton 75/50/20
PCAF yellow
IV. Penticton 10.7 cm Flux
Observed 09 Mar 143
Predicted 10 Mar-12 Mar 145/145/140
90 Day Mean 09 Mar 092
V. Geomagnetic A Indices
Observed Afr/Ap 08 Mar 004/005
Estimated Afr/Ap 09 Mar 005/008
Predicted Afr/Ap 10 Mar-12 Mar 020/022-012/018-008/008
VI. Geomagnetic Activity Probabilities 10 Mar-12 Mar
A. Middle Latitudes
Active 25/25/25
Minor storm 20/15/01
Major-severe storm 10/05/01
B. High Latitudes
Active 35/35/35
Minor storm 25/20/05
Major-severe storm 15/10/05