Joint USAF/NOAA Report of Solar and Geophysical Activity 1 October 2011
:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Oct 01 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 274 Issued at 2200Z on 01 Oct 2011
IA. Analysis of Solar Active Regions and Activity from 30/2100Z
to 01/2100Z: Solar activity has been moderate. Region 1305 (N12W12)
produced an M1/1n flare at 01/0959Z associated with an
Earth-directed CME. The CME became visible in STEREO imagery at
01/1109Z and has an estimated speed of 500 km/s. Region 1302
(N16W41) produced a Sf optical flare immediately before the M1 flare
at 01/0917Z. The two events were associated with a pair of Type II
Sweeps (620 km/s at 01/0906Z and 850 km/s at 01/0955Z), a Type IV
Sweep and a 180 sfu Tenflare. Region 1305 has grown slightly in area
and spot number and has a beta-gamma magnetic configuration. Region
1302 maintains an area of 700 millionths and a beta-gamma-delta
magnetic configuration.
IB. Solar Activity Forecast: Solar activity is expected to be low
to moderate with a slight chance for an X-class event from Regions
1302 and 1305 for the next three days (02-04 October).
IIA. Geophysical Activity Summary 30/2100Z to 01/2100Z:
The geomagnetic field was quiet to unsettled with isolated active
periods from 01/0000-0600Z as measured by the Boulder magnetometer.
The activity was a result of multiple solar sector boundary
crossings. 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 quiet to unsettled on day one (02 October) due to
effects from the coronal hole high speed stream and possible effects
from the CME observed on 29 September. Mostly quiet conditions are
expected on day two (03 October). Quiet to unsettled conditions with
a chance for active and isolated minor storm periods are expected on
day three (04 October) due to a combination of the CMEs observed on
30 September and 01 October. The two CMEs are due to arrive early
and late on day three, respectively.
III. Event Probabilities 02 Oct-04 Oct
Class M 70/70/70
Class X 20/20/20
Proton 15/15/15
PCAF green
IV. Penticton 10.7 cm Flux
Observed 01 Oct 137
Predicted 02 Oct-04 Oct 140/140/140
90 Day Mean 01 Oct 111
V. Geomagnetic A Indices
Observed Afr/Ap 30 Sep 005/008
Estimated Afr/Ap 01 Oct 012/012
Predicted Afr/Ap 02 Oct-04 Oct 008/008-005/005-015/015
VI. Geomagnetic Activity Probabilities 02 Oct-04 Oct
A. Middle Latitudes
Active 20/10/45
Minor storm 10/01/25
Major-severe storm 01/01/05
B. High Latitudes
Active 20/15/45
Minor storm 10/01/25
Major-severe storm 01/01/10
