[Ips-whfpr] ASWFC Weekly Prop. Report (17 September 25) issued 0055 UT on 17 Sep 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC WEEKLY HF PROPAGATION REPORT
ISSUED ON 17 SEPTEMBER 2025 
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (10 SEPTEMBER - 16 SEPTEMBER)
Date   T index   Conditions        
10 Sep   89      Normal-fair       
MUFS:
   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.

11 Sep  100      Normal            
MUFS:
   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.

12 Sep   86      Normal-fair       
MUFS:
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Mostly near predicted monthly values.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

13 Sep   77      Normal-fair       
MUFS:
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Northern Australian Region:
      Mostly near predicted monthly values.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 20% over the UT day.

14 Sep   81      Normal            
MUFS:
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Mostly near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

15 Sep  103      Fair              
MUFS:
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Enhanced by 20% during local day.
      Near predicted monthly values during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 25% over the UT day.

16 Sep   96      Normal            
MUFS:
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Mostly near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 30% over the UT day.

Predicted Monthly T index for September:  92

2. FORECAST (17 SEPTEMBER - 23 SEPTEMBER) 
MUFS: MUFs near predicted monthly values.

Propagation conditions: Normal. Isolated SWFs possible second 
half of the week due to possible returning solar region.

T index: 100
ASWFC HF Communications Warning 84 was issued on 15 September 
and is current for 15-17 Sep.

3. OUTLOOK (24 SEPTEMBER - 24 OCTOBER)
Degraded HF propagation conditions possible:
3, 6, 12-13-Oct

PLEASE NOTE:
Space weather conditions can frequently be determined by short 
timescale events that cannot be forecast a week in advance,
particularly at solar maximum.

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