[Ips-wsgr] ASWFC Weekly Solar and Geophysical Report (12 September 25) issued 0222 UT on 12 Sep 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC WEEKLY SOLAR AND GEOPHYSICAL REPORT 
ISSUED ON 12 SEPTEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx

1. SUMMARY (05 SEPTEMBER - 11 SEPTEMBER)
Date     05    06    07    08    09    10    11
10cm    149   146   133   124   121   119   115
AFr       8    17     0     0    18    13  ( 11)
Aaus      5    15     1    12     9     6  (  5)
T       114   121    92   101    84    89   100

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

05 Sep 
Solar:        R1, with an M1.4 at 0116UT
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Enhanced by 15% during local day.
      Enhanced by 30% during local night.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 25% during local night.
   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.

06 Sep 
Solar:        R1, with an M1.2 at 2215UT
Geomagnetic:  G0
In the BOM magnetometer data for 06 Sep, a weak (20nT) impulse 
was observed at 1424UT.
Frequencies:  
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Enhanced by 35% during local day.
      Enhanced by 20% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Enhanced by 20% during local day.
      Near predicted monthly values during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

07 Sep 
Solar:        R1, with an M1.2 at 2215UT
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

08 Sep 
Solar:        R0
Geomagnetic:  G0 chance of G1
Frequencies:  
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 35% during local night.
   Southern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

09 Sep 
Solar:        R0
Geomagnetic:  G1
Frequencies:  
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Enhanced by 20% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Southern Australian Region:
      Depressed by 15% during local day.
      Near predicted monthly values during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

10 Sep 
Solar:        R0
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Enhanced by 25% during local day.
      Depressed by 20% during local night.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.
      Up to 3db absorption observed in the Macquarie 
      Island 30 Mhz riometer early in the UT day on 10-Sep.

11 Sep 
Solar:        R0
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Enhanced by 25% during local day.
      Enhanced by 40% during local night.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

Comment: Planetary G2 conditions were briefly observed 
late in the UT day on 09-Sep. A planetary G1 period was 
observed on 06-Sep. 
 
2. FORECAST (12 SEPTEMBER - 18 SEPTEMBER)
Solar: 
R0-R1, with chance of isolated R2 activity if solar 
region AR4216 which has recently rotated onto the solar 
disk continues to develop in magnetic complexity.

Geomagnetic:  
G0 increasing to G1-G2 on 15-Sep. G1 conditions on 16-Sep. 
G0, chance of G1 early in the UT day 17-Sep with G0 
conditions expected for 18-Sep. The forecast geomagnetic 
activity is due to a coronal hole wind stream. 

Frequencies:  
MUFs initially near predicted monthly values. Southern 
Australian region MUFs are expected to become 15-20% 
depressed during 15-16 Sep in association with anticipated 
geomagnetic activity. MUFs are expected to remain near 
predicted monthly values on other days.


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