[Ips-wsgr] ASWFC Weekly Solar and Geophysical Report (25 April 25) issued 0044 UT on 25 Apr 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC WEEKLY SOLAR AND GEOPHYSICAL REPORT 
ISSUED ON 25 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx

1. SUMMARY (18 APRIL - 24 APRIL)
Date     18    19    20    21    22    23    24
10cm    156   157   156   163   163   167   170
AFr      11    18    14     0    13     0  ( 10)
Aaus      6    12     6    18     6     4  (  8)
T       116   121   103   105   113   121   124

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

18 Apr 
Solar:        R1, with an M4.4 at 2350UT
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Niue Island Region:
      Enhanced by 25%.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values.
      Hobart depressed 15-20% after dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 20% over the UT day.

19 Apr 
Solar:        R0
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Enhanced by 40% during local day.
      Enhanced by 25% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Mostly near predicted monthly values.
      Enhanced by 20% after local dawn.
   Southern Australian Region:
      Near predicted monthly values.
      Hobart 15-25% depressed after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

20 Apr 
Solar:        R1, with an M1.0 at 1211UT
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Enhanced by 35% during local day.
      Near predicted monthly values during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Hobart MUFs depressed 15-30%.
      Depressed by 15-30% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 30% over the UT day.

21 Apr 
Solar:        R1, with an M1.9 at 1837UT
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

22 Apr 
Solar:        R1, with an M1.3 at 1049UT
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 75% during local night.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

23 Apr 
Solar:        R0
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Enhanced by 20-40%.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Mostly near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

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

Comment: Southern Australian region MUFs were mildly
to moderately depressed with degraded HF conditions,
during local night hours for the interval 20-22 Apr 
in association with a mild increase in geomagnetic
activity induced by a coronal hole high speed wind 
stream. 

 
2. FORECAST (25 APRIL - 01 MAY)
Solar: 
R0-R1, with a chance for R2 flare activity from
28-Apr due to the possible return of a previously
flaring solar region. 

Geomagnetic:  
G1 periods possible 01-02 May. G0 on other days
of the week.

Frequencies:  
MUFs are expected to be generally near predicted 
monthly values, with southern Australian region 
MUFs depressed 15% after local dawn on 01-02 May. 
Increased chance of fadeouts later in 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