[Ips-whfpr] ASWFC Weekly Prop. Report (31 December 25) issued 0059 UT on 31 Dec 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC WEEKLY HF PROPAGATION REPORT
ISSUED ON 31 DECEMBER 2025 
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (24 DECEMBER - 30 DECEMBER)
Date   T index   Conditions        
24 Dec  103      Normal            
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):
      Near predicted monthly values over the UT day.

25 Dec  128      Normal            
MUFS:
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 30% during local night.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

26 Dec  128      Normal            
MUFS:
   Niue Island Region:
      Near predicted monthly values.
   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.

27 Dec  124      Normal            
MUFS:
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 30% during local night.
   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.

28 Dec  124      Normal            
MUFS:
   Niue Island Region:
      Near predicted monthly values.
   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.
      Enhanced by 15% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

29 Dec  120      Normal            
MUFS:
   Niue Island Region:
      Mostly near predicted monthly values.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
      Enhanced by 20% after local dawn.
   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.

30 Dec  137      Normal            
MUFS:
   Niue Island Region:
      Enhanced by 30% during local day.
      Enhanced by 35% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 30% 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.

Predicted Monthly T index for December:  89

2. FORECAST (31 DECEMBER - 06 JANUARY) 
MUFS: Maximum useable frequencies (MUFs) in the Australian region are expected
to be near predicted monthly values to 15% enhanced on 31-Dec, then decline to 
near predicted monthly values from 01-Jan. MUFs are generally expected to remain
at near predicted monthly values for the remainder of the week. 

Propagation conditions: Fair on 31-Dec. Mostly normal HF conditions are expected
for the remainder of the week. Isolated shortwave fadeouts are possible.

T index: 95

ASWFC Preliminary HF Communications Warning 125 was issued on 
29 December and is current for 31 Dec to 1 Jan.

3. OUTLOOK (07 JANUARY - 06 FEBRUARY)
Degraded HF propagation conditions possible:
13-14 Jan,  17-20 Jan, 26-27 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