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Thursday, November 04, 2021

Weekly Propagation Forecast Bulletins

 

Product: Weekly Highlights and Forecasts
:Issued: 2021 Nov 01 0509 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services
#
#                Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity 25 - 31 October 2021

Solar activity ranged from low to high levels. Low levels occurred on 25, 27, and 30-31 Oct. Moderate levels were reached on 26 and 29 Oct as Region 2891 (N17, L=212, class/area Dki/350 on 29 Oct) produced M1 flare activity at 26/0247 UTC, 26/1557, and 29/0242 UTC.

High levels were reached on 28 Oct as Region 2887 (S25, L=278, class/area Dki/440 on 24 Oct) produced an M1/1n flare at 28/0740 UTC, an M2/1f flare at 28/1028 UTC, and an X1/2n flare at 28/1535 UTC. Two CMEs were modeled during the period. The first was a CME off the SE limb beginning at 26/2024 UTC although the source region was unclear. It was speculated to come from Region 2887. WSA ENLIL modeling showed a potential glancing arrival late on 30 Oct. The second CME was associated with the X1 flare on 28 Oct. Type II (1457 km/s) and IV radio emissions were observed coinciding with the flare and WSA ENLIL modeling of the event showed an arrival of mid to late on 30 Oct as well, although parameterization of the event was difficult. 

Coinciding with the X1 flare on 28 Oct was a greater than 10 MeV and 100 MeV proton event. The greater than 10 MeV event began at 28/1740 UTC, reached a peak flux of 29 pfu (S1-Minor) at 29/0250 UTC and began at 30/2100 UTC, reaching a peak flux of 11pfu at 30/2105 UTC and ending at 30/2130 UTC due to an enhancement from the 26 Oct CME. The greater than 100 MeV proton event began at 28/1635 UTC, reached a peak flux of 7.3 pfu at 28/1815 UTC and ended at 30/0440 UTC. The greater than 10 MeV proton flux continued to decline towards background levels on 31 Oct - 01 Nov. 

The greater than 2 MeV electron flux at geosynchronous orbit was observed at 25/1700 UTC 

Geomagnetic field activity was at quiet levels on 25 Oct through late on 30 Oct under a nominal solar wind environment. Around 30/1800 UTC, a weak discontinuity was observed that was believed to be the arrival of the 26 Oct CME. The total field increased to 11 nT while the Bz component deflected southward to a maximum of -10 nT at 30/2045 UTC. Solar wind speed slowly increased to 400 km/s. A weak shock was observed beginning at 31/0914 UTC which is believed to be the arrival of a glancing blow from the 28 Oct CME. The total field increased from 4 nT to 13 nT while the Bz component briefly reached a maximum southward deflection of -11 nT at 31/1124 UTC. Solar wind speed continued to rise to a peak of 465 km/s at 31/1905 UTC. By 31/1500 UTC, the total field had calmed to between 5-8 nT and remained there through the end of the period. The geomagnetic field responded with an isolated active period late on 30 Oct followed by unsettled to G1 (Minor) storming on 31 Oct. 

Forecast of Solar and Geomagnetic Activity 01 November - 27 November 2021

Solar activity is expected to be at low levels with a chance for further M-class flare activity (R1-R2, Minor-Moderate) on 01-08 Nov as Regions 2887 and 2891 transit across the visible disk. Very low to low levels are expected on 09-15 Nov. Low levels with a chance for M-class flares are likely again on 16-27 Nov as Regions 2887 and 2891 return to the visible disk on 16 Nov and 21 Nov, respectively. 

No proton events are expected at geosynchronous orbit as Regions 2887 and 2891 decay and simplify magnetically. 

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at normal to moderate levels with a chance for high levels on 02-03 Nov due to CME influence. 

Geomagnetic field activity is expected to reach active levels on 01 Nov followed by quiet to unsettled levels on 02 Nov as CME effects diminish. Unsettled levels are expected once again on 04-05 Nov and 15-16 Nov due to recurrent CH HSS activity. 

Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2021 Nov 01 0509 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services
#
#      27-day Space Weather Outlook Table
#                Issued 2021-11-01
#
#   UTC      Radio Flux   Planetary   Largest
#  Date       10.7 cm      A Index    Kp Index
2021 Nov 01     103          16          4
2021 Nov 02     102           8          3
2021 Nov 03     100           5          2
2021 Nov 04      98           8          3
2021 Nov 05      96           8          3
2021 Nov 06      96           5          2
2021 Nov 07      96           5          2
2021 Nov 08      92           5          2
2021 Nov 09      90           5          2
2021 Nov 10      88           5          2
2021 Nov 11      88           5          2
2021 Nov 12      88           5          2
2021 Nov 13      88           5          2
2021 Nov 14      88           5          2
2021 Nov 15      89          10          3
2021 Nov 16      92           8          3
2021 Nov 17      92           5          2
2021 Nov 18      92           5          2
2021 Nov 19      92           5          2
2021 Nov 20      93           5          2
2021 Nov 21      95           5          2
2021 Nov 22      95           5          2
2021 Nov 23      95           5          2
2021 Nov 24      95           5          2
2021 Nov 25      95           5          2
2021 Nov 26      95           5          2
2021 Nov 27      95           5          2
(NOAA)