[Ips-dhfpr] ASWFC Daily HF Prop Report - 13 December 25 issued 2330 UT on 13 Dec 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/13 DECEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (13 DECEMBER) 
Date   T index  Conditions    
13 Dec    28    Fair           

Flares: none.

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.

PCA Event : No event.

Monthly T index:
Month  T index
Nov      103
Dec      89
Jan      89


2. FORECAST (14 DECEMBER - 16 DECEMBER)
Date   T index  Conditions       MUFs                              
14 Dec    70    Fair-normal      Depressed 15 to 20%/near predicted 
                                 monthly values
15 Dec    85    Normal           Near predicted monthly values    
16 Dec    85    Normal           Near predicted monthly values   

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 13-Dec were 35% depressed to near predicted 
monthly values, with depressed conditions observed during the 
local day. Sporadic E was observed during local night hours. 
MUFs in the southern Australian region are 20% depressed after 
local dawn this morning. MUFs are expected to be initially 15-20% 
depressed on 14-Dec then gradually recovering and near predicted 
monthly values. MUFs are expected to be near predicted monthly 
values on 15-16 Dec.

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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