Tuesday, August 16, 2011

Weekly Propagation Forecast Bulletins

Product: Weekly Highlights and Forecasts
:Issued: 2011 Aug 16 1738 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




Highlights of Solar and Geomagnetic Activity 08 - 14 August 2011

Solar activity began the week at moderate levels with an M3/1b flare at 08/1810 UTC from Region 1263 (N17, L=301, class/area Ekc/720 on 04 August). This event was associated with a type II radio sweep and a partial-halo coronal mass ejection which was mostly directed away from the west limb. Region 1263 produced an additional M2/1b flare at 09/0354 UTC. Activity levels increased to high as Region1263 produced an X6/2b flare at 09/0805 UTC which was associated with type II and type IV radio sweeps as well as a full halo CME, which also appeared to be primary travelling away from the west limb.The X6 is the largest x-ray event for cycle 24 so far. Activity levels dropped down to low levels on 10 August as Region 1263 rotated around the west limb. Activity levels further decreased to very low levels on 12 August and remained there through the end of the summary period.

A greater than 10 MeV proton enhancement was observed beginning at 08/1905 UTC in association with the M3 flare from Region 1263. The enhancement peaked at 4 PFU at 08/2000 UTC. Greater than 100 MeV and 10 MeV proton events began on 09 August in association with the X6 flare described previously. The greater than 100 MeV proton event began at 09/0825 UTC, reached a peak of 2.6 PFU at 09/0840 UTC, and dropped below threshold at 09/1035 UTC. The greater than 10 MeV proton event began at 09/0845 UTC, reached a peak of 26 PFU at 09/1210 UTC, and ended at 09/1715 UTC.

The greater than 2 MeV electron flux at geosynchronous orbit reached high levels on 08 August and stayed high through the end of the day on 13 August. The electron flux levels were at normal to moderate levels on 14 August.

Geomagnetic field activity began the week at generally quiet to unsettled levels with isolated active and minor storm periods at the high latitudes. Activity decreased to quiet levels for 11-12 August and then increased slightly to quiet to unsettled levels for 14 August. Solar wind observations from the ACE spacecraft showed a positive polarity coronal hole high speed stream from 08-10 August. Solar wind data also indicated a solar sector boundary on the 13th at about 2000 UTC, followed by the onset of a negative polarity coronal hole high speed stream.

Forecast of Solar and Geomagnetic Activity 17 August - 12 September 2011

Solar activity is expected to be very low to low for 17-23 August. An increase to low to moderate is expected as old Region 1263 returns and transits the disk from 24 August to 06 September. Activity levels are likely to return to low or very low levels for the remainder of the outlook interval from 07-12 September. In addition there continues to be a chance that a new, rapidly emerging flux region could increase activity to moderate or greater levels at any time during the outlook period.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to increase to high levels for 18-23 August. Moderate levels are expected for 24-27 August, followed by a few days for high levels for 28-29 August. Low to moderate levels should prevail for 30 August through 04 September, followed by another increase to high levels for 05-07 September. Normal levels should resume on 08 September and continue through the end of the outlook period.

Geomagnetic field activity is expected to be generally quiet to unsettled for 17-22 August as there may be weak driving from a coronal hole high speed stream (HSS). Quiet levels should prevail for 23-25 August and another increase to quiet to unsettled is expected for 26-28 August from another HSS. Quiet levels are expected to return for 29 August through 02 September. An increase to unsettled with a chance for active periods is expected for 03-05 September due to another recurrent HSS. Quiet levels should predominate for 06-10 September, and another increase to quiet to unsettled from a recurrent HSS is expected for 11-12 September.

Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2011 Aug 16 1738 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 2011-08-16
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2011 Aug 17 95 10 3
2011 Aug 18 95 5 2
2011 Aug 19 95 5 2
2011 Aug 20 97 5 2
2011 Aug 21 97 8 3
2011 Aug 22 100 5 2
2011 Aug 23 100 5 2
2011 Aug 24 105 5 2
2011 Aug 25 110 5 2
2011 Aug 26 115 15 3
2011 Aug 27 115 10 3
2011 Aug 28 110 8 3
2011 Aug 29 110 5 2
2011 Aug 30 110 5 2
2011 Aug 31 110 5 2
2011 Sep 01 105 5 2
2011 Sep 02 105 5 2
2011 Sep 03 105 8 3
2011 Sep 04 100 10 3
2011 Sep 05 100 10 3
2011 Sep 06 95 10 3
2011 Sep 07 95 7 2
2011 Sep 08 90 5 2
2011 Sep 09 90 5 2
2011 Sep 10 90 5 2
2011 Sep 11 90 8 3
2011 Sep 12 90 12 3
(NOAA)