Joint USAF/NOAA Report of Solar and Geophysical Activity 18 September 2012

:Product: Report of Solar-Geophysical Activity
:Issued: 2012 Sep 18 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 262 Issued at 2200Z on 18 Sep 2012
IA. Analysis of Solar Active Regions and Activity from 17/2100Z
to 18/2100Z: Solar activity has been at low levels for the past 24
hours. New Region 1575 (N07E75) was responsible for the only C-class
event today, which was a C1 x-ray event at 1009Z. This region was
also responsible for the two C-class events observed yesterday. When
Region 1575 rotated onto the visible disk, it had a beta magnetic
classification. No Earth directed CME’s were detected in the past 24
hours.
IB. Solar Activity Forecast: Solar activity is expected to be at
low levels with a slight chance for M-class events for the next
three days (19-21 September).
IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field has been at quiet to unsettled levels for the
past 24 hours. Solar wind speeds, as measured by the ACE spacecraft,
indicated nominal background speeds with sustained periods of the
negative Bz component of the IMF.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to remain at quiet to unsettled levels for the next two
days (19-20 September). A slight increase to quiet to unsettled
levels with chance for active periods is expected on day three (21
September) as a coronal hole high speed stream moves into a
geoeffective position.
III. Event Probabilities 19 Sep-21 Sep
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 18 Sep 104
Predicted 19 Sep-21 Sep 105/110/110
90 Day Mean 18 Sep 122
V. Geomagnetic A Indices
Observed Afr/Ap 17 Sep 006/004
Estimated Afr/Ap 18 Sep 009/009
Predicted Afr/Ap 19 Sep-21 Sep 008/010-009/010-008/012
VI. Geomagnetic Activity Probabilities 19 Sep-21 Sep
A. Middle Latitudes
Active 15/15/25
Minor storm 05/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/20
Minor storm 30/30/30
Major-severe storm 25/25/30