Product: Weekly Highlights and Forecasts
:Issued: 2021 May 31 0313 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 24 - 30 May 2021
Solar activity was at very low levels on 24-25 and 30 May while an increase to low levels occurred on 26-29 May. The majority of the flare activity was from Regions 2824 (N20, L=196, class/area Dho/250 on 27 May) and 2826 (N24, L=215, class/area Dko/280 on 27 May).
The largest flare of the period was a C9/1f at 28/2313 UTC from Region 2824. Associated with this flare were Type II and Type IV radio sweeps along with a CME observed off the west limb in the SOHO/LASCO C2 imagery beginning at the 28/2312 UTC. WSA/ENLIL modeling of the CME showed the bulk of the plasma directed off the Sun-Earth line, however, there was potential for a glancing blow late on 01 Jun to early on 02 Jun.
A greater than 10 MeV proton event (S1-Minor) began at 29/0300 UTC, reached a peak flux of 15 pfu at 29/0320 UTC, and ended at 29/0540 UTC associated with the aforementioned C9 flare on 28 May.
The greater than 2 MeV electron flux at geosynchronous orbit reached high levels on 24-26 May and decreased to normal-moderate levels on 27-30 May. The largest flux of the period was 1,530 pfu being observed at 25/1825 UTC.
Geomagnetic field activity ranged from quiet to G1 (Minor) geomagnetic storm levels. The period began with nominal solar wind conditions and quiet levels through early on 26 May. At 26/1148 UTC an impulsive increase in solar wind speed from approximately 300-350 km/s was observed with then a simultaneous increase in the total field from 3-8 nT, marking the arrival of a possible conglomeration of CMEs from 22-23 May.
Total field continued to increase to 16 nT through early on 27 May while solar wind speed increased to 400-450 km/s. The geomagnetic field responded with unsettled to G1 (Minor) storm levels in the second half on 26 May, followed by quiet to active levels on 27 May. Solar wind speed continued between 380-490 km/s through the end of the period. Quiet conditions were once again observed on 28 May followed by quiet to unsettled levels on 29-30 May.
Forecast of Solar and Geomagnetic Activity 31 May - 26 June 2021
Solar activity is expected to be at very low to low levels on 31 May - 11 Jun and again on 26 Jun. A slight chance for moderate (R1-Minor) flares exists on 12-25 Jun with the return of Region 2824 to the visible disk.
No proton events are expected at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 18-22 Jun due to coronal hole high-speed stream (CH HSS) influence.
Geomagnetic field activity is expected to reach unsettled to active levels on 01-04 Jun due to a combination of CH HSS effects as well as the potential for a glancing blow from the 28 May CME late on 01 Jun to early on 02 Jun. Unsettled to active levels are expected again on 16-17 Jun, with G1 (Minor) storm levels likely on 16 Jun due to recurrent CH HSS effects. Unsettled levels are likely to be on 26 Jun due to a possible reoccurring solar sector boundary crossing (SSBC).
Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2021 May 31 0313 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 2021-05-31
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2021 May 31 72 5 2
2021 Jun 01 72 18 4
2021 Jun 02 72 15 4
2021 Jun 03 72 8 3
2021 Jun 04 72 8 3
2021 Jun 05 72 5 2
2021 Jun 06 72 5 2
2021 Jun 07 72 5 2
2021 Jun 08 72 5 2
2021 Jun 09 73 5 2
2021 Jun 10 75 5 2
2021 Jun 11 76 5 2
2021 Jun 12 78 5 2
2021 Jun 13 78 5 2
2021 Jun 14 78 5 2
2021 Jun 15 78 5 2
2021 Jun 16 80 20 5
2021 Jun 17 80 10 3
2021 Jun 18 80 5 2
2021 Jun 19 78 5 2
2021 Jun 20 78 5 2
2021 Jun 21 78 5 2
2021 Jun 22 78 5 2
2021 Jun 23 76 5 2
2021 Jun 24 75 5 2
2021 Jun 25 73 5 2
2021 Jun 26 72 8 3
(NOAA)