Highlights of Solar and Geomagnetic Activity
22 - 28 April 2024

Solar activity reached high levels on 22 Apr and 24 Apr. Moderate
levels were observed on 23 Apr, 25 Apr, and 27 Apr. Finally, low
levels were observed on 26 Apr and 28 Apr. In total, there were 20
low-level M-class events (R1-Minor) over the past week. The
strongest was an M3.6 flare at 23/0319 UTC from Region 3654 (S07,
L=135, class/area=Ekc/310 on 28 Apr). Of the 24 numbered active
regions observed on the visible disk, 6 produced M-class activity. 

Type II radio events were observed on the 22 Apr, 23 Apr, and 24
Apr. The 23 Apr event was associated with an M2.9 flare at 23/1744
UTC from Region 3645 (S09, L=226, class/area=Dki/290 on 21 Apr). The
24 Apr event was associated with a C9.4 flare at 24/1410 UTC from
Region 3638 (S18, L=227, class/area=Cri/080 on 21 Apr) and was also
accompanied by a Type IV radio sweep. The associated CMEs are likely
to have been associated with geomagnetic activity observed at Earth
over 26 Apr. The region produced numerous, small, slow-moving CMEs
that were primarily directed south of the ecliptic plane over the
week. 

An additional CME first observed ~27/1100 UTC in SOHO/LASCO C2
imagery, which originated from the vicinity of Region 3654, was
analyzed and modeled. The results suggested a component along the
Sun-Earth line with effects likely to be observed around 01 May. 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit reached
high levels on 25 Apr. The remainder of the summary was at normal to
moderate levels. 

Geomagnetic field activity was ranged from quiet to G1 (Minor)
geomagnetic storm levels. G1 levels observed on 26 Apr are thought
to be associated with transient influence from activity that
occurred on the Sun several days earlier. Unsettled conditions on 27
Apr were observed the Bz component of the IMF turned northward.
Active conditions were reached early on 28 Apr due to a positive
polarity CH HSS. The remainder of the summary period was at quiet to
unsettled levels. 

Forecast of Solar and Geomagnetic Activity
29 April - 25 May 2024

Solar activity is expected to be at low levels with a chance for
M-class (R1-R2/Minor-Moderate) activity over the outlook period.
Primarily contributors to flare probability include Region 3654
currently in the western hemisphere and a collective of active and
adjacent regions in the southern hemisphere which are due to return
to the visible disk over 08-10 May. 

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be normal to moderate levels over the outlook period. 

Geomagnetic field activity is expected to range from quiet to active
levels. Active levels on the 01-02 May are anticipated due to likely
influence from combined effects of a CH HSS and transient effects of
a CME that left the Sun on 27 Apr. Active levels on 23-24 May and
unsettled levels on 29-30 Apr and 03-07 May are expected due to
recurrent CH HSS features. The remainder of the outlook period is
likely to be at mostly quiet levels. 

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