Joint USAF/NOAA Report of Solar and Geophysical Activity 5 October 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Oct 05 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 278 Issued at 2200Z on 05 Oct 2011
IA. Analysis of Solar Active Regions and Activity from 04/2100Z
to 05/2100Z: Solar activity for the past 24 hours has been at low
levels. New Region 1313 (S13E65) rotated onto the southeast limb
early in the period and has been responsible for a majority of the
activity. Region 1313, produced the largest event of the period, a
C9/Sf flare at 05/1242Z. Multiple CME’s were observed during the
past 24 hours, but none of them were considered to be geoeffective.
IB. Solar Activity Forecast: Solar activity is expected to be at
low to moderate levels for the next three days (06-08 October) as
Region 1313 continues to evolve.
IIA. Geophysical Activity Summary 04/2100Z to 05/2100Z:
The geomagnetic field has been at quiet to minor storm levels during
the past 24 hours. At 05/0742, a Sudden Impulse (SI) of 19 nT was
observed by the Boulder magnetometer. Following this SI, solar wind
speeds, as measured by the ACE spacecraft, increased from 370 km/s
to around 480 km/s. The IMF also increased to around 12 nT, with
some extended periods of southward Bz. These characteristics are
congruent with the arrival of a CME. 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 remain at unsettled to active levels with a chance for
minor storm periods on day one (06 October). Predominantly quiet to
unsettled levels are expected for days two and three (07-08 October)
as the effects of the CME’s wane.
III. Event Probabilities 06 Oct-08 Oct
Class M 40/40/40
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 05 Oct 127
Predicted 06 Oct-08 Oct 125/125/130
90 Day Mean 05 Oct 113
V. Geomagnetic A Indices
Observed Afr/Ap 04 Oct 004/006
Estimated Afr/Ap 05 Oct 015/018
Predicted Afr/Ap 06 Oct-08 Oct 015/015-008/008-008/008
VI. Geomagnetic Activity Probabilities 06 Oct-08 Oct
A. Middle Latitudes
Active 45/20/20
Minor storm 25/05/05
Major-severe storm 05/01/01
B. High Latitudes
Active 45/25/25
Minor storm 30/10/10
Major-severe storm 05/01/01