Product: Weekly Highlights and Forecasts
:Issued: 2021 May 24 0337 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 17 - 23 May 2021
Solar activity ranged from very low to moderate levels with the majority of the flare activity caused by Region 2824 (N21, L=195, class/area Csi/190 on 22 May). Very low levels were observed on 17 and 19-20 May with Low levels occurring on 18 and 21 May. Activity increased to moderate levels on 22-23 May due to a series of M1 flares from Region 2824 at 22/1711, 22/2136, and 23/1108 UTC. And in addition to the M-class flares were several noteworthy C-class flares, including an impulsive C6/1n at 22/0256 UTC with an associated Type II (1530 km/s) Radio sweep, an impulsive C6/1n with an associated Type II (653 km/s), and a long duration C1 at 22/0844 UTC. Multiple CME signatures were observed from the region associated with these flares (and others). Each was modelled and put into a consolidated WSA-ENLIL run showing arrival times beginning late on 25 May.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels with a peak flux of 1,040 pfu which was briefly reached at 22/1635 UTC.
Geomagnetic field activity ranged from quiet to G1 (Minor) geomagnetic storm levels. The period began with nominal solar wind values in the 325-420 km/s range through early on 20 May. An isolated active period was observed early on 18 May due to possible weak CME influence from 13 May. The geomagnetic field was quiet on 17 May, quiet to active on 18 May, and quiet to be unsettled on 19 May.
Beginning at 20/1845 UTC, the total field increased to 19 nT while solar wind speed subsequently were increased to near 575 km/s due to the onset of a negative polarity coronal hole high-speed stream (CH HSS). Solar wind speed slowly decreased back to nominal levels by the end of the period. The geomagnetic field responded with quiet to G1 (Minor) storm levels on 20 May, quiet to unsettled on 21 May, and quiet levels thereafter.
Forecast of Solar and Geomagnetic Activity 24 May - 19 June 2021
Solar activity is expected to be low with a chance for further M-class flares on 24-30 May as Region 2824 rotates across the visible disk. Very low levels are expected on 31 May - 11 Jun. Low levels are expected to return on 12-19 Jun as Region 2824 rotates back onto 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 26-29 May due to CME enhancements.
Geomagnetic field activity is expected to reach G1 (Minor) storm levels on 25-27 May with G2 (Moderate) storming on 26 May due to the arrival of multiple CMEs from 22-23 May. G1 (Minor) storming is also likely on 16 Jun as a recurrent, negative polarity CH HSS is expected to become geoeffective.
Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2021 May 24 0337 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 2021-05-24
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2021 May 24 79 5 2
2021 May 25 79 18 5
2021 May 26 79 42 6
2021 May 27 79 25 5
2021 May 28 76 8 3
2021 May 29 79 5 2
2021 May 30 79 5 2
2021 May 31 76 5 2
2021 Jun 01 76 5 2
2021 Jun 02 76 5 2
2021 Jun 03 74 5 2
2021 Jun 04 74 5 2
2021 Jun 05 74 5 2
2021 Jun 06 74 5 2
2021 Jun 07 74 5 2
2021 Jun 08 74 5 2
2021 Jun 09 74 5 2
2021 Jun 10 74 5 2
2021 Jun 11 75 5 2
2021 Jun 12 77 5 2
2021 Jun 13 77 5 2
2021 Jun 14 77 5 2
2021 Jun 15 77 5 2
2021 Jun 16 79 20 5
2021 Jun 17 79 10 3
2021 Jun 18 79 5 2
2021 Jun 19 79 5 2
(NOAA)
