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Monday, September 24, 2012

Weekly Propagation Forecast Bulletins



Product: Weekly Highlights and Forecasts
:Issued: 2012 Sep 24 1239 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC web contact www.swpc.noaa.gov/weekly.html
#
#                Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity 17 - 23 September 2012

Solar activity reached low levels this week. C-class x-ray flares were observed on 17-20 and 23 September. The largest, a C2/Sf, was recorded from Region 1576 (S21, L=180, class/area Dso/70 on 20 September) at 19/1512 UTC. The remainder included a C2 flare from Region 1575 (N08, L=181, class/area Eko/320 on 22 September) at 17/1406 UTC, a C1 at 18/1009Z, and a C1 from Region 1574 (S22, L=302, class/area Cao/40 on 20 September) at 20/1139 UTC, and a long-duration C1 from beyond the east limb at 23/1556 UTC. The long-duration C-flare was associated with a vivid CME in LASCO C2 imagery. Estimated plane-of-sky speed was around 600 km/s.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit reached moderate levels each day of the week except the 20th when it remained at background levels.

The geomagnetic field ranged from quiet to active levels during the week, with minor storm levels observed at high latitudes on all but the first and last days. The week began with the geomagnetic field at quiet to unsettled levels. Geomagnetic field activity increased to active levels late on the 19th when a corotating interaction region (CIR) became geoeffective. A coronal hole high speed stream
followed on the 20th bringing mostly quiet to unsettled conditions. Between the 19th and the 20th, the solar sector changed from positive to negative, consistent with the geoeffective coronal hole
polarity. Solar wind speed at the ACE spacecraft fluctuated between 600 and 400 km/s between the 20th and 21st, before beginning a slow decline late on the 21st. Solar wind speed by the end of the week had dropped to about 350 km/s. The Bz component of the interplanetary magnetic field reached its maximum of approximately -11 nT late on the 19th with the arrival of the CIR.

Forecast of Solar and Geomagnetic Activity 24 September - 20 October 2012

Solar activity is expected to be at low levels with an increasing chance for moderate activity during the first two weeks of the period as active regions rotate onto the visible disk.

A slight chance for a proton event exists due to potential activity associated with returning regions from 24 September through 08 October.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels on 8-9 October and again on 17-18 October.

Geomagnetic field activity is expected to remain mostly at quiet to unsettled levels except for 3-5 October, 09-10 October, and 16-17 October when recurrent coronal hole high speed streams are expected to bring a chance for active levels.

Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2012 Sep 24 1239 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC web contact  www.swpc.noaa.gov/wwire.html
#
#      27-day Space Weather Outlook Table
#                Issued 2012-09-24
#
#   UTC      Radio Flux   Planetary   Largest
#  Date       10.7 cm      A Index    Kp Index
2012 Sep 24     135           5          2
2012 Sep 25     140           5          2
2012 Sep 26     145           5          2
2012 Sep 27     145           5          2
2012 Sep 28     150           5          2
2012 Sep 29     150           5          2
2012 Sep 30     145           5          2
2012 Oct 01     140           5          2
2012 Oct 02     135           5          2
2012 Oct 03     130          10          3
2012 Oct 04     130           8          3
2012 Oct 05     130           8          3
2012 Oct 06     125           5          2
2012 Oct 07     125           5          2
2012 Oct 08     120           5          2
2012 Oct 09     115           8          3
2012 Oct 10     115           8          3
2012 Oct 11     120           5          2
2012 Oct 12     115           5          2
2012 Oct 13     115           5          2
2012 Oct 14     120           5          2
2012 Oct 15     120           8          3
2012 Oct 16     130          12          3
2012 Oct 17     140          10          3
2012 Oct 18     140           5          2
2012 Oct 19     145           5          2
2012 Oct 20     150           5          2
(NOAA)