NOAA / Space Weather Prediction Center

Solar Flare 3-day Report of Solar and Geophysical Activity
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Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Weather Prediction Center and the U.S. Air Force.
Updated 2012 Oct 13 2200 UTC


Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 287 Issued at 2200Z on 13 Oct 2012

IA.  Analysis of Solar Active Regions and Activity from  12/2100Z
to 13/2100Z:  Solar activity was very low.  Region 1589 (N13E22) is
the most magnetically complex spot group on the visible disk with a
Beta-Gamma-Delta magnetic configuration.  No Earth-directed CMEs
were observed during the reporting period.

IB.  Solar Activity Forecast:  Solar activity is expected to be low
with a chance for M-class flares and a slight chance for X-class
flares during the forecast period (14-16 October).

IIA.  Geophysical Activity Summary 12/2100Z to 13/2100Z:
The geomagnetic field ranged from quiet to minor storm levels with
major to severe storm periods observed at high latitudes.  The
period began with quiet to unsettled conditions through 13/0300Z.  A
sustained period of southward Bz to -11 nT for approximately 13
hours resulted in active to minor storm conditions with major to
severe storm periods at high latitudes.  At about 13/0650Z, the phi
angle changed from a negative (toward) orientation to a positive
(away) orientation, indicating a solar sector boundary crossing. 
This was followed by increases in density, temperature, and solar
wind speed indicative of a co-rotating interaction region in advance
of a coronal hole high speed stream (CH HSS).  By 13/1618Z, solar
wind speed increased from approximately 530 km/s to 590 km/s while
the total magnetic field (Bt) decreased to 5 nT as the CH HSS became
geoeffective. 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 continue at unsettled to active levels with a chance for
isolated minor storm periods on day 1 (14 October).  Mostly
unsettled conditions are expected on day 2 (15 October) due to
persistence.  By day 3 (16 October), quiet to unsettled conditions
are expected as coronal hole effects wane.  On days 2-3, there is a
slight chance for a greater than 10 MeV proton event at
geosynchronous orbit as Region 1589 rotates into a more geoeffective
position.

III.  Event Probabilities 14 Oct-16 Oct
Class M    35/35/35
Class X    10/10/10
Proton     05/10/10
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           13 Oct 125
Predicted   14 Oct-16 Oct  125/130/130
90 Day Mean        13 Oct 117

V.  Geomagnetic A Indices
Observed Afr/Ap 12 Oct  012/014
Estimated Afr/Ap 13 Oct  025/036
Predicted Afr/Ap 14 Oct-16 Oct  016/018-011/012-007/010

VI.  Geomagnetic Activity Probabilities 14 Oct-16 Oct
A.  Middle Latitudes
Active                30/30/15
Minor storm           20/10/05
Major-severe storm    05/01/01
B.  High Latitudes
Active                10/15/15
Minor storm           25/30/20
Major-severe storm    55/40/20