Weekly Highlights of Solar and Geomagnetic Activity, 03 - 09 April 2023

[SWPC.We...@noaa.gov]

:Product: Weekly Highlights and Forecasts
:Issued: 2023 Apr 10 0353 UTC
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# Weekly Highlights and Forecasts
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Highlights of Solar and Geomagnetic Activity
03 - 09 April 2023

Solar activity was at low to moderate levels. Low levels were
observed on 03-05, 07, and 09 Apr while moderate levels were
observed on 06 and 08 Apr. Region 3272 (S21, L=102, class/area
Eai/280 on 09 Apr) was responsible for the majority of the C-class
activity since its emergence on 05 Apr. The region also produced M3
and M2/1n flares at 06/0553 UTC and 08/0146 UTC, respectively. Other
activity included a CME off the SW limb first observed at 07/1336
UTC that was associated with a filament eruption seen in SDO/AIA 304
imagery beginning at 07/0829 UTC centered near S27W10. Modelling
indicated a miss, however a glancing blow could not be ruled out
early on 12 Apr.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit reached
high levels throughout the period due to CH HSS influence. The
maximum flux was 4,290 pfu observed at 03/1455 UTC.

Geomagnetic field activity ranged from quiet to active levels. The
period began with solar wind speed around 528 km/s with total field
near 6-7 nT under negative polarity CH HSS influence. By late on 05
Apr, solar wind speed returned to nominal levels until 09/2158 UTC
when total field showed a small increase to 8 nT. The geomagnetic
field responded with quiet to active levels on 03-04 Apr, quiet to
unsettled levels on 05-07 and 09 Apr, and quiet levels on 08 Apr.

Forecast of Solar and Geomagnetic Activity
10 April - 06 May 2023

Solar activity is expected to be low with a chance for moderate
levels (R1-R2, Minor-Moderate) on 10-25 Apr and again from 02-06 May
due to flare potential of Region 3272 and the return of old Region
3256 (S22, L=001) on 12 Apr. Very low to low levels are expected on
26 Apr-01 May.

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 10-11 Apr and again on 23 Apr-06
May due to recurrent CH HSS influence.

Geomagnetic field activity is expected to reach unsettled levels on
10-11 Apr due to CH HSS activity. Unsettled to active levels are
expected on 12 Apr due to a combination of HSS influence and a
possible glancing blow from the 07 Apr CME. Unsettled to active
levels are expected again on 17-18 Apr, 20-22 Apr, and 26 Apr-04 May
with G1 (Minor) storming likely on 20, 27, and 30 Apr due to
recurrent CH HSS activity.