Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 23 November 2012

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 328 Issued at 2200Z on 23 Nov 2012

IA. Analysis of Solar Active Regions and Activity from 22/2100Z to
23/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C1 event observed at
23/1212Z from Region 1618 (N08W27). Although this region retained its
beta-gamma-delta magnetic characteristics, it experienced intermediate
penumbral decay. All other regions on the disk remained stable and
quiet. Between 1200 and 1300Z, a 29 degree filament was observed in SDO
AIA 304 imagery lifting off from the southeast limb. The subsequent CME
was observed in STEREO-A and B COR2 imagery beginning around 1400Z.
Using geometric localization, a preliminary speed of approximately 550
km/s was obtained. This suggests an arrival at earth early on 27
November.

IB. Solar Activity Forecast: Solar activity is expected to be at low
levels, with a slight chance for moderate activity, for the entire
forecast period (24-26 Nov).

IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
at the ACE spacecraft reached 389km/s at 23/2117Z. Total IMF reached 12
nT at 23/2116Z. The maximum southward component of Bz was -8.8 nT at
23/2112Z. These values coincided with the arrival of an interplanetary
shock at ACE around 23/2112Z from the 20 Nov CME. The greater than 2
MeV electron flux at geosynchronous orbit reached a maximum of 1408 pfu.

IIB. Geophysical Activity Forecast: Geomagnetic field activity is
expected to begin at active levels and reach major storm levels early on
day one (24 Nov) with the effects from the 20 Nov CME coupled with the
anticipated arrival of the 21 Nov CME. On day two (25 Nov), conditions
are expected to return to unsettled to active levels due to residual CME
effects combined with a coronal hole high speed stream. The unsettled
levels may persist into day three (26 November).

III. Event probabilities 24 Nov-26 Nov
Class M 20/20/20
Class X 05/05/05
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 23 Nov 126
Predicted 24 Nov-26 Nov 125/120/115
90 Day Mean 23 Nov 123

V. Geomagnetic A Indices
Observed Afr/Ap 22 Nov 001/001
Estimated Afr/Ap 23 Nov 005/007
Predicted Afr/Ap 24 Nov-26 Nov 023/090-013/018-006/005

VI. Geomagnetic Activity Probabilities 24 Nov-26 Nov
A. Middle Latitudes
Active 35/30/05
Minor Storm 30/15/01
Major-severe storm 10/05/01
B. High Latitudes
Active 10/15/15
Minor Storm 20/30/10
Major-severe storm 65/50/05