[Ips-whfpr] ASWFC Weekly Prop. Report (17 December 25) issued 0049 UT on 17 Dec 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

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

1. SUMMARY (10 DECEMBER - 16 DECEMBER)
Date   T index   Conditions        
10 Dec  148      Normal            
MUFS:
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Enhanced by 15% during local day.
      Enhanced by 35% during local night.
   Northern Australian Region:
      Enhanced by 25% during local day.
      Enhanced by 25% during local night.
   Southern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 15% during local night.
      Enhanced by 20% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

11 Dec  117      Normal-fair       
MUFS:
   Cocos Island Region:
      Mostly near predicted monthly values.
   Niue Island Region:
      Enhanced by 20% during local day.
      Enhanced by 15% during local night.
   Northern Australian Region:
      Mostly near predicted monthly values.
      Enhanced by 25% after local dawn.
   Southern Australian Region:
      Enhanced by 20% during local day.
      Near predicted monthly values during local night.
      Depressed by 20% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

12 Dec   81      Fair              
MUFS:
   Cocos Island Region:
      Mostly near predicted monthly values.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 30% during local night.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
      Depressed by 35% after local dawn.
   Southern Australian Region:
      Depressed by 15% during local day.
      Near predicted monthly values during local night.
      Depressed by 35% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

13 Dec   28      Fair              
MUFS:
   Cocos Island Region:
      Depressed by 50% during local day.
      Depressed by 35% during local night.
      Depressed by 20% after local dawn.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 30% during local night.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Depressed by 35% during local day.
      Near predicted monthly values during local night.
   Southern Australian Region:
      Depressed by 30% during local day.
      Near predicted monthly values during local night.
      Depressed by 25% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 25% over the UT day.

14 Dec   73      Fair-normal       
MUFS:
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Depressed by 15% during local day.
      Near predicted monthly values.
   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.

15 Dec  110      Normal-fair       
MUFS:
   Cocos Island Region:
      Mostly near predicted monthly values.
   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.
      Enhanced by 20% during local night.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

16 Dec   81      Normal-fair       
MUFS:
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      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 15% over the UT day.

Predicted Monthly T index for December:  89

2. FORECAST (17 DECEMBER - 23 DECEMBER) 
MUFS: depressed by 10-15% on 18-Dec 

Propagation conditions: mildly degraded over 17-18 Dec.
Conditions normal on other days.

T index: 89

3. OUTLOOK (24 DECEMBER - 23 JANUARY)
Degraded HF propagation conditions possible:
30-Dec to 01-Jan,08-09 Jan, 14-Jan
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