Joint USAF/NOAA Report of Solar and Geophysical Activity 23 October 2012

:Product: Report of Solar-Geophysical Activity
:Issued: 2012 Oct 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 297 Issued at 2200Z on 23 Oct 2012
IA. Analysis of Solar Active Regions and Activity from 22/2100Z
to 23/2100Z: Solar activity has been high. Region 1598 (S12E44)
produced an X1 event with an associated Tenflare and Type-II radio
sweep at 23/0317Z. There was no CME observed in association with
this event. Region 1598 remains the most threatening region on the
disk and appears to have a Delta magnetic configuration within its
trailer spots. Region 1596 (N07E06) is also moderately sized and
has some magnetic complexity, but did not produce any flares during
the period. Region 1593 (N15W33) produced a long-duration C3 event
at 23/0821Z with an associated CME seen on STEREO-A imagery. There
is not enough data available to model the CME, but at this time it
does not appear likely to be geoeffective. Newly numbered Region
1599 (S09E73) appears to have a simple alpha magnetic class. The
other regions on the disk either remained stable or were decaying.
IB. Solar Activity Forecast: Solar activity is expected to be
moderate to high with occasional M-class events, and a slight chance
for an isolated X-class event for the next three days (24 – 26 Oct)
with Region 1598 the most likely source.
IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z:
The geomagnetic field was quiet for the past 24 hours. Solar wind
speed, as measured at the ACE spacecraft, remained steady throughout
the period at approximately 370 km/s. The Bz component of the
interplanetary magnetic field ranged from +/- 4 nT and the Phi angle
changed to a positive sector at 22/2300Z. These signatures are
consistent with a solar sector boundary crossing. The greater than 2
MeV electron flux at geosynchronous orbit was at high levels
throughout the period.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet for the next three days (24 – 26 Oct).
III. Event Probabilities 24 Oct-26 Oct
Class M 75/75/75
Class X 20/20/20
Proton 05/10/15
PCAF green
IV. Penticton 10.7 cm Flux
Observed 23 Oct 142
Predicted 24 Oct-26 Oct 140/140/140
90 Day Mean 23 Oct 121
V. Geomagnetic A Indices
Observed Afr/Ap 22 Oct 002/002
Estimated Afr/Ap 23 Oct 007/007
Predicted Afr/Ap 24 Oct-26 Oct 006/005-006/005-006/005
VI. Geomagnetic Activity Probabilities 24 Oct-26 Oct
A. Middle Latitudes
Active 05/05/05
Minor storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor storm 15/15/10
Major-severe storm 05/05/05