[Ips-wsgr] ASWFC Weekly Solar and Geophysical Report (24 April 26) issued 0422 UT on 24 Apr 2026 [SEC=OFFICIAL]

Fri Apr 24 14:22:22 AEST 2026

SUBJ: ASWFC WEEKLY SOLAR AND GEOPHYSICAL REPORT 
ISSUED ON 24 APRIL 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx

1. SUMMARY (17 APRIL - 23 APRIL)
Date     17    18    19    20    21    22    23
10cm    107   106   105   105   112   116   128
AFr       3    24    16    13    14     4  (  9)
Aaus      2    20    13    14    12     2  (  3)
T        66    90    71    63    34    47    55

Solar:        Solar flare activity
Geomagnetic:  Geomagnetic activity observed for Australian region.
Frequencies:  Australian ionospheric F2 critical frequencies

17 Apr 
Solar:        R0
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Enhanced by 25% during local day.
      Near predicted monthly values during local night.
      Depressed by 20% after local dawn.
   Niue Island Region:
      Depressed by 15% during local day.
      Depressed by 30% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

18 Apr 
Solar:        R0
Geomagnetic:  G2
Frequencies:  
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 30% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 30% during local night.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

19 Apr 
Solar:        R0
Geomagnetic:  G2
Frequencies:  
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 35% during local night.
   Niue Island Region:
      Mostly near predicted monthly values.
      Depressed by 25% after local dawn.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 35% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
      Depressed by 20% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 25% over the UT day.

20 Apr 
Solar:        R0
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Near predicted monthly values during local day.
      No data available during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

21 Apr 
Solar:        R0
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      No data available during local day.
      No data available during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 35% during local night.
   Southern Australian Region:
      Depressed by 40% during local day.
      Depressed by 40% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 25% over the UT day.

22 Apr 
Solar:        R0
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      No data available during local day.
      No data available during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 35% during local night.
      Depressed by 20% after local dawn.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
   Southern Australian Region:
      Depressed by 20% during local day.
      Depressed by 25% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

23 Apr 
Solar:        R1, with an M1.6 at 0435UT, an M4.3 at 0848UT, 
              an M1.7 at 1400UT, and an M4.9 at 1708UT
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      No data available during local day.
      No data available during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 30% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 30% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

2. FORECAST (24 APRIL - 30 APRIL)
Solar: 
R1 solar flare activity, with a chance of R2, is forecast over 
24-26 Apr due to ongoing flare activity from Active Region 4419. 
R1 solar flare activity is forecast to continue over 27-30 Apr 
due to ongoing activity from Active Region 4420, as well as a 
returning active region likely rotating onto the visible disk 
on 25-26 Apr.

Geomagnetic:  
G0, with a chance of G1 geomagnetic conditions are forecast 
for 25-Apr due to coronal hole high speed wind stream effects. 
G1-G2 geomagnetic conditions are forecast for 26-Apr due to a 
coronal mass ejection impact, combined with residual high‑speed
 wind stream effects. G0 geomagnetic conditions, with a chance 
of G1, are forecast for 29-Apr, with G0-G1 forecast on 30-Apr 
due to the arrival of a second recurrent coronal hole high 
speed wind stream.

Frequencies:  
Maximum Usable Frequencies (MUFs) may become depressed by 
approximately 15% on 25-Apr and again on 29-30 Apr due to 
recurrent coronal hole high speed wind stream influences. MUFs 
are likely to be depressed by 15-25% on 26-27 Apr due to a 
glancing coronal mass ejection impact. MUFs are expected to 
be near predicted monthly values on other days this week. 
Shortwave fadeouts are possible throughout the week.

For an explanation of some of the terms in this report, go to
https://www.sws.bom.gov.au, and follow links to Educational->
Glossary on Solar Terrestrial Terms.

Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au