[Ips-wsgr] ASWFC Weekly Solar and Geophysical Report (26 September 25) issued 0045 UT on 26 Sep 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC WEEKLY SOLAR AND GEOPHYSICAL REPORT 
ISSUED ON 26 SEPTEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx

1. SUMMARY (19 SEPTEMBER - 25 SEPTEMBER)
Date     19    20    21    22    23    24    25
10cm    160   166   176   172   171   184   170
AFr       7     5     6     0     0     6  (  8)
Aaus      1     1     3    11    11     6  (  6)
T        96   107   114   128   124   127   129

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

19 Sep 
Solar:        R1, with an M1.5 at 2141UT
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 25% during local night.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Enhanced by 15% over the UT day.

20 Sep 
Solar:        R0
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 30% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15-50% during local night.
   Southern Australian Region:
      Mostly near predicted monthly values.
      Enhanced by 25% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Enhanced by 15% over the UT day.

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

22 Sep 
Solar:        R0
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Mostly near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 30% during local night.
   Southern Australian Region:
      Enhanced by 20% during local day.
      Enhanced by 30% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Enhanced by 15% over the UT day.

23 Sep 
Solar:        R1, with an M1.0 at 1034UT
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Enhanced by 25% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
      Enhanced by 20% after local dawn.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
      Enhanced by 25% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

24 Sep 
Solar:        R1, with an M1.0 at 0931UT, and an M1.6 at 
              1913UT
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Enhanced by 20% during local day.
      Enhanced by 100% during local night.
   Niue Island Region:
      Enhanced by 40% during local day.
      Enhanced by 35% during local night.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
      Enhanced by 30% after local dawn.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

25 Sep 
Solar:        R0
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Enhanced by 55% during local day.
      Enhanced by 85% during local night.
   Niue Island Region:
      Enhanced by 15-20% during local day.
   Northern Australian Region:
      Enhanced by 15%.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

 
2. FORECAST (26 SEPTEMBER - 02 OCTOBER)
Solar: 
R0-R1. No magnetically complex solar region 
is currently on the solar disk. Most solar regions
are small to medium in size and showing decay, with the
exception of solar region AR4230 in the solar south east 
quadrant is currently growing.

Geomagnetic:  
G0, chance G1 27-28 Sep due to possible mild 
geomagnetic activity from coronal hole wind 
stream. G0 on other days.


Frequencies:  
MUFs near predicted monthly values to 15% enhanced.
Mildly degraded HF conditions possible local night
hours for the southern Australian region 27-28 Sep.


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