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Wednesday, October 05, 2011

Weekly Propagation Forecast Bulletins

Product: Weekly Highlights and Forecasts
:Issued: 2011 Oct 04 2337 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 26 September - 02 October 2011

Solar activity ranged from low to moderate levels during the period. Activity was moderate on 26 September with Region 1302 (N12, L=282, class/area Fkc/1300 on 24 September) producing a M4/1b event at 26/0508 UTC and a M2/2b event at 26/1443 UTC. Solar activity decreased to low levels on 27 September before increasing again to moderate levels on 28 September when Region 1302 produced a M1/1n event at 28/1328 UTC with an associated Tenflare (320 sfu). Another decrease to low levels occurred on 29 September before levels increased once again to moderate levels on 30 September through 02 October. Region 1305 (N12, L-249, class/area Dsi/190 on 2 October) produced a M1/1f event at 30/1906 UTC. Associated with this event was a Type II radio sweep with an estimated speed of 690 km/s as well as a 260 sfu Tenflare. Despite limited STEREO data, a slower CME is believed to be potentially geoeffective from this event. Region 1305 produced a M1/1n event at 01/0959 UTC, and produced a possible earth directed CME, with an associated Type II radio sweep (estimated speed of 850 km/s), Type IV radio sweep, and a 180 sfu Tenflare. On 02 October, Region 1305 produced a M3/1n event at 02/0050 UTC that was associated with an Earth directed CME visible in STEREO imagery with an estimated speed of 532 km/s. Finally,Region 1302 produced a M1/Sf event at 02/1723 UTC.

A greater than 10 MeV proton event at geosynchronous orbit began at 23/2255 UTC in response to an X1 flare on 22 September, reached a maximum of 35 pfu at 26/1155 UTC, and ended at 27/0430 UTC. Fluxes returned to background levels for the remainder of the period.

The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels from 26 to 29 September. Fluxes increased to high levels on 30 September, returned to normal to moderate levels on 01 October, and back to high levels on 02 October.

Geomagnetic activity ranged from quiet to severe storm levels during the period. Increased activity on 26 - 28 September was due to effects of an expected CME from 24 September. Increased activity early on 29 September was due to nighttime sub-storms. Increased activity on 01 - 02 October was due to a solar sector boundary crossing (SSBC) prior to the onset of high speed stream (HSS) effects from a favorably positioned coronal hole (CH).

Forecast of Solar and Geomagnetic Activity 05 October - 31 October 2011

Solar activity is expected to be at low to moderate levels during 05 - 15 October with a slight chance for M-class flare activity from Region 1305 until it crosses the west limb on 07 October, and the return of old Region 1295 (N24, L=57) on 08 October. A decrease to low levels is expected during 16 - 17 October after Region 1295 rotates off the west limb. During 18 - 25 October, activity is expected to increase to low to moderate levels with a slight chance for major flare activity as old Region 1302 rotates back onto the visible disk. Activity is expected to return to low levels for the remainder of the forecast period (26 - 31 October) after old Region 1302 rotates off the west limb.

No proton events are expected at geosynchronous orbit from 05 - 17 October. There is a slight chance for a proton enhancement from 18 - 27 October due to the return of old Region 1302. No proton events are expected during 25 - 31 October.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at mostly normal to moderate levels. High levels are expected during 9 - 14 and 28 - 31 October due to influences from coronal hole high speed streams.

Geomagnetic field activity is expected to be mostly unsettled on 05 October due to a CME arrival. Activity is expected to increase to active levels on 06 October due to continued CME effects. Activity is expected to decrease to mostly unsettled levels during 07 - 09 October as effects from the CME subside and a negative polarity coronal hole moves into a geoeffective position. Activity is expected to continue to decrease to mostly quiet levels during 10 - 27 October. During 28 - 30 October, activity is expected to return to mostly unsettled levels due to a positive polarity coronal hole. Finally, activity is expected to decrease to mostly quiet levels on 31 October.

Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2011 Oct 04 2337 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 2011-10-04
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2011 Oct 05 125 15 5
2011 Oct 06 120 18 5
2011 Oct 07 120 8 3
2011 Oct 08 115 8 3
2011 Oct 09 115 8 3
2011 Oct 10 115 5 2
2011 Oct 11 115 5 2
2011 Oct 12 115 5 2
2011 Oct 13 115 5 2
2011 Oct 14 110 5 2
2011 Oct 15 110 5 2
2011 Oct 16 110 5 2
2011 Oct 17 115 5 2
2011 Oct 18 120 5 2
2011 Oct 19 125 5 2
2011 Oct 20 125 5 2
2011 Oct 21 125 5 2
2011 Oct 22 125 5 2
2011 Oct 23 125 5 2
2011 Oct 24 125 5 2
2011 Oct 25 125 5 2
2011 Oct 26 125 5 2
2011 Oct 27 125 5 2
2011 Oct 28 125 8 3
2011 Oct 29 125 8 3
2011 Oct 30 120 8 3
2011 Oct 31 120 5 2
(NOAA)