Joint USAF/NOAA Report of Solar and Geophysical Activity 12 March 2012

:Product: Report of Solar-Geophysical Activity
:Issued: 2012 Mar 12 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 072 Issued at 2200Z on 12 Mar 2012
IA. Analysis of Solar Active Regions and Activity from 11/2100Z
to 12/2100Z: Solar activity was low. Region 1430 (N22W67) produced
a C2 flare at 12/0155Z. Previously active Region 1429 (N18W50) is
now an Ekc type spot group with a beta-gamma magnetic configuration.
IB. Solar Activity Forecast: Solar activity is expected to be low
with a chance for moderate levels. A slight chance for an isolated
X-class flare remains possible from Region 1429.
IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z:
The geomagnetic field ranged from quiet to major storm levels with
isolated periods of severe storm levels at high latitudes. The ACE
spacecraft observed a sudden storm commencement at 12/0843Z with
wind speeds escalating from 445 to 560 km/s. Total field strength
reached a peak of 28nT and Bz dropped as low as -21nT. A sudden
impulse was observed at 12/0921Z (96nT, as measured by the Boulder
magnetometer). Solar wind speeds reached up to 775 km/s during the
event. The greater than 10 MeV proton event at geosynchronous orbit
remains near 10 pfu as of forecast issue. 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 active to major storm levels on day one (13 March)
due to CME effects. Unsettled to active conditions are expected on
day two (14 March) as CME effects subside. Day three (15 March) the
geomagnetic field is expected to return to quiet levels.
III. Event Probabilities 13 Mar-15 Mar
Class M 30/30/30
Class X 10/10/10
Proton 60/40/20
PCAF yellow
IV. Penticton 10.7 cm Flux
Observed 12 Mar 115
Predicted 13 Mar-15 Mar 115/115/110
90 Day Mean 12 Mar 125
V. Geomagnetic A Indices
Observed Afr/Ap 11 Mar 010/009
Estimated Afr/Ap 12 Mar 021/030
Predicted Afr/Ap 13 Mar-15 Mar 035/065-015/025-005/005
VI. Geomagnetic Activity Probabilities 13 Mar-15 Mar
A. Middle Latitudes
Active 30/25/05
Minor storm 35/15/01
Major-severe storm 20/05/01
B. High Latitudes
Active 10/15/15
Minor storm 20/25/15
Major-severe storm 65/40/05