Joint USAF/NOAA Report of Solar and Geophysical Activity 1 November 2011
:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Nov 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 305 Issued at 2200Z on 01 Nov 2011
IA. Analysis of Solar Active Regions and Activity from 31/2100Z
to 01/2100Z: Solar activity was low. Newly numbered Region 1338
(S12E69) produced the largest flare of the period; a C5 flare at
31/2322Z. Another new region, responsible for M-class flare
activity on 31 October, is currently rotating into view on the
Northeast limb and was numbered Region 1339 (N22E71). A CME was
observed in SOHO/LASCO C2 imagery at 31/1700Z with the majority of
the ejecta off the Northeast limb. The CME was associated with a
disappearing solar filament (DSF) that was observed in SDO/AIA 193
imagery at 31/1426Z. STEREO B COR 2 imagery had a plane of sky
speed of approximately 503 km/s. A glancing blow from this CME is
possible early on 04 November.
IB. Solar Activity Forecast: Solar activity is expected to be low
to moderate. Further M-class flares are likely from new Region
1339.
IIA. Geophysical Activity Summary 31/2100Z to 01/2100Z:
The geomagnetic field ranged from quiet to minor storm levels with
major and severe storm periods observed at high latitudes. At
approximately 01/0817Z, a shock arrival was observed at the ACE
spacecraft. Solar wind speed increased from approximately 370 km/s
to 420 km/s while the total magnetic field (IMF Bt) increased from 5
to 15 nT. A sudden impulse (SI) of 18 nT was observed on the
Boulder magnetometer at 01/0907Z. This event was possibly due to
transient activity associated with a DSF on 28 October.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled with isolated active periods
possible on day 1 (02 November) due to continued activity from
transient activity on 01 November. Mostly quiet conditions are
expected on days 2 – 3 (03 – 04 November).
III. Event Probabilities 02 Nov-04 Nov
Class M 60/60/60
Class X 05/05/05
Proton 05/05/05
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 01 Nov 139
Predicted 02 Nov-04 Nov 145/145/150
90 Day Mean 01 Nov 125
V. Geomagnetic A Indices
Observed Afr/Ap 31 Oct 009/008
Estimated Afr/Ap 01 Nov 015/027
Predicted Afr/Ap 02 Nov-04 Nov 008/010-005/005-005/005
VI. Geomagnetic Activity Probabilities 02 Nov-04 Nov
A. Middle Latitudes
Active 10/05/05
Minor storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/05/05
Minor storm 05/01/01
Major-severe storm 01/01/01