:Product: Weekly Highlights and Forecasts
:Issued: 2021 May 10 0452 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
# https://www.swpc.noaa.gov/content/subscription-services
#
# Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity
03 - 09 May 2021

Solar activity was at very low to moderate levels. Region 2822 (N18,
L=335, class/area Dsi/180 on 09 May) rotated onto the visible disk
on 07 May and produced an M3/1n flare at 07/1904 UTC. Associated
with this flare were type II (816 km/s) and Type IV radio sweeps as
well as a non-Earth directed CME. C-class flares were observed on
08-09 May, including a long duration C2/Sf flare at 09/1449 UTC with
an associated Type II (407 km/s) radio sweep and another CME
beginning at 09/1436 UTC in SOHO/LASCO C2 imagery. A faint,
partial-halo CME was also observed on 09 May associated with a 15
degree filament eruption centered near S22E10. The CME was first
observed in C2 imagery beginning at 09/1124 UTC. The two CMEs from
09 May are being analyzed at the time of this report with the
potential for at least one having an Earth-directed component.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at
normal to moderate levels through the period.

Solar wind parameters were weakly enhanced on 03-05 May under a
positive polarity CH HSS. Solar wind speed increased to a maximum of
498 km/s at 03/2351 UTC while total field reached a maximum of 13 nT
at 03/0500 UTC. The Bz component was mostly positive during this
time resulting in quiet conditions. By midday on 05 May, solar wind
speed had decreased to under 350 km/s and remained so through 09
May. Quiet conditions were observed for the rest of the period.

Forecast of Solar and Geomagnetic Activity
10 May - 05 June 2021

Solar activity is expected to be very low to low with the chance for
further M-class flares on 10-19 May as Region 2822 rotates across
the visible disk. Very low to low levels are expected on 20-27 May
with the return of old Region 2821 (S21, L=226). Very low levels are
expected on 28 May-01 Jun. Very low to low levels are expected again
on 02-05 Jun as Region 2822 rotates around the east limb.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be reach high levels on 16-19 May and again on 21-24 May
due to recurrent CH HSS influences.

Geomagnetic field activity is expected to reach unsettled levels on
10, 12-13, 15-18, 20-21 May. Active levels are expected on 15-17 and
20 May and G1 (Minor) storm levels are likely on 16 May due to
recurrent CH HSS effects.