Product: Weekly Highlights and Forecasts
:Issued: 2024 Apr 22 0200 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 15 - 21 April 2024
Solar activity reached moderate levels on 15 Apr, 16-19 Apr and 21 Apr and was at low levels on 20 Apr. A large amount of numbered regions were recorded on the visible disk, with 26 in total. Region 3639 (N26, L=222, class/area=Eki/320 on 17 Apr) produced the highest flare of the period, an M4.0/1n (R1-Minor) at 15/1932 UTC. 17 other M-class (R1) flares were observed this period from multiple other regions. An complex area of sunspot groups was observed in the southern hemisphere. Region 3638 (S17, L=226, Cai/beta) was far from the most magnetically complex of the group but was very active in its production of eruptions associated with numerous CMEs over the past week. Most of the ejecta was thought to move south of the ecliptic but some of the activity may have produced CMEs whose periphery may be on the Sun-Earth line.
Other activity included an eruption N of Region 3636 (S21, L=251, Class/area=Cso/100 on 13 Apr) around 15/0557 UTC. A faint CME thought to be associated with the event was observed in SOHO/LASCO C2 imagery beginning after 15/0648 UTC. Modeling of the CME
suggested arrival on 18 Apr but the most pronounced portion of the CME was observed passing Earth over 19 Apr.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit ranged from normal background to moderate levels.
Geomagnetic field activity was ranged from quiet to G3 (Strong) geomagnetic storm levels this period. Quiet to unsettled conditions on 15 Apr increased to G1 (Minor) geomagnetic storm levels due to transient influence from a CME activity on the Sun over 12 Apr.
Quiet to unsettled conditions on 17 Apr were associated with a weak passing CME that left the Sun on 14 Apr. Quiet conditions were then observed on 18 Apr as solar wind conditions trended towards nominal levels. An increase to G3 (Strong) geomagnetic storm conditions were observed with the passage of CME associated with activity on the Sun over 15 Apr. Total magnetic field strength (Bt) reached a peak of 18 nT at 19/1425 UTC. The Bz component was sustained in a far southward orientation with a maximum deflection of -17 nT observed at 19/1421 UTC. Solar wind speeds steadily increased from the low 300's to ~500 km/s by the end of 19 Apr. Bt returned to near 5 nT on 20 Apr and the geomagnetic field responded with quiet to unsettled conditions. Active conditions were again observed on 21 Apr following additional periods of sustained Bz south.
Forecast of Solar and Geomagnetic Activity 22 April - 18 May 2024
Solar activity is expected to be moderate levels (R1-R2/Minor-Moderate), with a chance for X-class flare R3 (Strong), over 22-27 Apr due to a plethora of productive sunspots rotating towards the W limb. As those spots groups rotate off, solar activity is
likely to be a low levels with a chance for M-class (R1-R2), through the remainder of the outlook period due to both developing spots in the E hemisphere and the return of productive spot groups on the farside of the Sun. There is a chance for the greater than 10 MeV proton flux at geosynchronous orbit to reach above the S1 (Minor) levels over 22-27 Apr due to the plethora of sunspots in the W hemisphere.
The greater than 2 MeV electron flux at geosynchronous orbit may reach high levels on 22-25 Apr in response to geomagnetic activity observed on 19 Apr.
Geomagnetic field activity is like to reach active levels over 22-24 Apr and 26-27 Apr in response to multiple coronal hole high speed streams (CH HSSs). There is potential for combined influence of coronal hole activity and multiple weak transients over 22-24 Apr. Unsettled levels are likely on 25 Apr, 01-03 May, and 05-07 May due to the anticipated return of multiple other weak CH HSSs. The remainder of the outlook period is likely to be at mostly quiet levels.
Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2024 Apr 22 0200 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 2024-04-22
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2024 Apr 22 215 10 4
2024 Apr 23 215 15 4
2024 Apr 24 200 10 4
2024 Apr 25 190 12 3
2024 Apr 26 170 15 4
2024 Apr 27 170 15 4
2024 Apr 28 165 12 3
2024 Apr 29 160 8 3
2024 Apr 30 155 7 2
2024 May 01 155 10 3
2024 May 02 160 10 3
2024 May 03 160 10 3
2024 May 04 160 5 2
2024 May 05 160 8 3
2024 May 06 160 8 3
2024 May 07 165 8 3
2024 May 08 170 5 2
2024 May 09 180 5 2
2024 May 10 185 5 2
2024 May 11 190 5 2
2024 May 12 195 5 2
2024 May 13 200 5 2
2024 May 14 210 5 2
2024 May 15 215 5 2
2024 May 16 215 5 2
2024 May 17 212 5 2
2024 May 18 212 5 2
(NOAA)