Joint USAF/NOAA Report of Solar and Geophysical Activity 4 September 2012

:Product: Report of Solar-Geophysical Activity
:Issued: 2012 Sep 04 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 248 Issued at 2200Z on 04 Sep 2012
IA. Analysis of Solar Active Regions and Activity from 03/2100Z
to 04/2100Z: Solar activity was low. Region 1564 (S14E14 –
Esi/beta-gamma) was the most active region, producing occasional
low-level C-class flares. It increased in spot count and area during
the first half of the period, but showed gradual spot and penumbral
decay during the latter half of the period. Region 1560 (N04W47 –
Eai/beta-gamma-delta) showed a slight decrease in spots and area,
but maintained a delta in its interior spots. No significant changes
were observed in the remaining spotted regions and no new regions
were numbered. No Earth-directed CME activity was observed during
the period.
IB. Solar Activity Forecast: Solar activity is expected to be low
through the period (05 – 07 September) with a chance for an isolated
M-class flare.
IIA. Geophysical Activity Summary 03/2100Z to 04/2100Z:
Geomagnetic field activity ranged from quiet to minor storm levels
with major storm periods detected at high latitudes, all due to
residual CME effects. The greater than 10 MeV proton event at
geosynchronous orbit that began at 01/1335Z, reached a maximum of 59
pfu at 02/0850Z, and ended at 04/0625Z.
IIB. Geophysical Activity Forecast: Geomagnetic field activity is
expected to be at quiet to unsettled levels during days 1 – 2 (05 –
06 September) with a chance for active levels. This is due to the
arrival of CMEs observed on 02 September along with a co-rotating
interaction region in advance of a coronal hole high-speed stream
(CH HSS). The CMEs are expected to arrive around midday on day 1.
The CH HSS is expected to commence on day 2. Field activity is
expected to be at quiet to unsettled levels on day 3 (07 September)
as CH HSS effects subside.
III. Event Probabilities 05 Sep-07 Sep
Class M 25/25/25
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 04 Sep 138
Predicted 05 Sep-07 Sep 135/135/130
90 Day Mean 04 Sep 124
V. Geomagnetic A Indices
Observed Afr/Ap 03 Sep 023/040
Estimated Afr/Ap 04 Sep 012/014
Predicted Afr/Ap 05 Sep-07 Sep 010/012-010/010-007/008
VI. Geomagnetic Activity Probabilities 05 Sep-07 Sep
A. Middle Latitudes
Active 20/15/15
Minor storm 05/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor storm 30/20/25
Major-severe storm 30/25/20