[Ips-dhfpr] ASWFC Daily HF Prop Report - 22 December 25 issued 2330 UT on 22 Dec 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/22 DECEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (22 DECEMBER) 
Date   T index  Conditions    
22 Dec    75    Fair           

Flares: none.

MUFs:
   Cocos Island Region:
      Depressed by 20% during local day.
      Near predicted monthly values during local night.
   Niue Island Region:
      Mostly near predicted monthly values.
      Depressed by 20% after local dawn.
   Northern Australian Region:
      Mostly near predicted monthly values.
      Briefly depressed by 25% after local dawn.
   Southern Australian Region:
      Near predicted monthly values.
      Depressed by 15% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

PCA Event : No event.

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


2. FORECAST (23 DECEMBER - 25 DECEMBER)
Date   T index  Conditions       MUFs                              
23 Dec    75    Fair             Depressed 10 to 15%/near predicted 
                                 monthly values
24 Dec    75    Fair             Depressed 10 to 15%/near predicted 
                                 monthly values    
25 Dec    75    Fair-normal      Depressed 10 to 15%/near predicted 
                                 monthly values   

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 22-Dec were near predicted monthly values during 
the local day and briefly 15-25% depressed after local dawn this 
morning. Spread F was observed during local night hours at Hobart 
and Canberra. MUFs are forecast to be 10-15% depressed on 23-25 
Dec due to ongoing mild geomagnetic activity. Isolated minor 
shortwave fadeouts are possible.

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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