Joint USAF/NOAA Report of Solar and Geophysical Activity 20 September 2010

:Product: Report of Solar-Geophysical Activity
:Issued: 2010 Sep 20 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 263 Issued at 2200Z on 20 Sep 2010
IA. Analysis of Solar Active Regions and Activity from 19/2100Z
to 20/2100Z: Solar activity was low. A C2 X-ray event was observed
at 20/1945Z. The event appeared to originate from an emerging flux
region on the east limb near N20. Region 1106 (S21W53) decayed in
the trailer portion of the spot group, but maintained a bi-polar
magnetic configuration. Region 1108 (S30E24) exhibited little change
during the period.
IB. Solar Activity Forecast: Solar activity is expected to be very
low to low with a slight chance of M-class activity for the next
three days (21 – 23 September).
IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z:
The geomagnetic field was quiet.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels, with isolated active
periods, for day one (21 September). Mostly unsettled, with
isolated active to minor storm levels, are expected on days two and
three (22 – 23 September). The increase in activity is due to a
large, recurrent coronal hole high speed stream.
III. Event Probabilities 21 Sep-23 Sep
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 20 Sep 083
Predicted 21 Sep-23 Sep 083/083/084
90 Day Mean 20 Sep 078
V. Geomagnetic A Indices
Observed Afr/Ap 19 Sep 002/004
Estimated Afr/Ap 20 Sep 003/005
Predicted Afr/Ap 21 Sep-23 Sep 008/012-015/018-015/018
VI. Geomagnetic Activity Probabilities 21 Sep-23 Sep
A. Middle Latitudes
Active 20/30/30
Minor storm 01/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 25/35/35
Minor storm 05/10/10
Major-severe storm 01/01/01