Joint USAF/NOAA Report of Solar and Geophysical Activity 2 October 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Oct 02 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 275 Issued at 2200Z on 02 Oct 2011
IA. Analysis of Solar Active Regions and Activity from 01/2100Z
to 02/2100Z: Solar activity was moderate. Regions 1302 (N16W55) and
1305 (N12W26) both produced M-class events during the past 24 hours.
The largest was an M3/1n from Region 1305 at 02/0050Z that was
associated with an Earth-directed CME visible in STEREO imagery with
an estimated speed of 532 km/s. Region 1302 decreased significantly
in area but maintained a beta-gamma-delta magnetic configuration.
Region 1305 developed some intermediate spots but held steady in
area and is still considered to have a beta-gamma magnetic class.
Region 1309 (N23E67) was numbered yesterday and is a Dso type group
with a beta magnetic configuration.
IB. Solar Activity Forecast: Solar activity is expected to be low
to moderate with a slight chance for X-class activity for the next
three days (03-05 October) due to flare potential from Regions 1302
and 1305.
IIA. Geophysical Activity Summary 01/2100Z to 02/2100Z:
The geomagnetic field was quiet to unsettled with an isolated active
period during the 02/0900-1200Z synoptic period as measured by the
Boulder magnetometer. The increase in activity was due to effects
from a favorably positioned coronal hole high speed stream (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 mostly quiet on days one and two (03-04 October) as
effects from the CH HSS subside. Day three (05 October) is expected
to begin with quiet to unsettled conditions. A chance for active
conditions and a slight chance for isolated minor storm periods is
expected later in the day due to effects from the combination of the
CMEs observed on 30 September and 01 October.
III. Event Probabilities 03 Oct-05 Oct
Class M 75/75/75
Class X 20/20/15
Proton 15/15/10
PCAF green
IV. Penticton 10.7 cm Flux
Observed 02 Oct 131
Predicted 03 Oct-05 Oct 130/130/130
90 Day Mean 02 Oct 112
V. Geomagnetic A Indices
Observed Afr/Ap 01 Oct 012/009
Estimated Afr/Ap 02 Oct 010/010
Predicted Afr/Ap 03 Oct-05 Oct 005/005-005/005-015/015
VI. Geomagnetic Activity Probabilities 03 Oct-05 Oct
A. Middle Latitudes
Active 15/05/40
Minor storm 05/01/20
Major-severe storm 01/01/05
B. High Latitudes
Active 15/05/45
Minor storm 05/01/20
Major-severe storm 01/01/05