Report of Solar-Geophysical Activity

Issued: 2012 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 275 Issued at 2200Z on 01 Oct 2012

IA.  Analysis of Solar Active Regions and Activity from  30/2100Z
to 01/2100Z:  Solar activity was low.  Region 1575 (now around the
west limb) produced several C-class x-ray events during the period,
the greatest a C9 at 30/2339Z. No Earth-sided CMEs were observed
leaving the solar disk.
IB.  Solar Activity Forecast:  Solar activity is expected to be low
for day 1 (2 October). Activity is expected to be very low to low on
days 2 and 3 (3 and 4 October), as the complex or regions near the
western extent of the visible solar disk continue beyond the limb.
IIA.  Geophysical Activity Summary 30/2100Z to 01/2100Z:
The geomagnetic field began the period at active levels, as weak CME
effects from the previous period continued in progress. The first
period of 1 October saw an increase to severe storm levels, after a
second CME arrived at ACE around 30/2221Z with a subsequent Sudden
Impulse (SI) to Earth's magnetic field (35nT measured at Boulder) at
30/2307Z.  A single major storm period followed, before conditions
decreased to active and then again to quiet.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be quiet to unsettled on day 1 (2 October) as CME
effects wane. Days 2 and 3 (3 and 4 October) should see mostly quiet
conditions.
III.  Event Probabilities 02 Oct-04 Oct
Class M    05/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           01 Oct 128
Predicted   02 Oct-04 Oct  125/125/125
90 Day Mean        01 Oct 124
V.  Geomagnetic A Indices
Observed Afr/Ap 30 Sep  009/013
Estimated Afr/Ap 01 Oct  017/031
Predicted Afr/Ap 02 Oct-04 Oct  008/010-004/005-004/005
VI.  Geomagnetic Activity Probabilities 02 Oct-04 Oct
A.  Middle Latitudes
Active                15/05/05
Minor storm           01/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor storm           25/15/15
Major-severe storm    15/05/05