[Ips-dhfpr] ASWFC Daily HF Prop Report - 04 October 25 issued 2330 UT on 04 Oct 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/04 OCTOBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (04 OCTOBER) 
Date   T index  Conditions    
04 Oct   121    Fair-normal    

Flares: none.

MUFs:
   Cocos Island Region:
      Enhanced by 20-30%.
   Niue Island Region:
      Enhanced by 25% during local day.
      Near predicted monthly values during local night.
      Enhanced by 25% after local dawn.
   Northern Australian Region:
      Enhanced by 25% during local day.
      Enhanced by 40% during local night.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

PCA Event : No event.

Monthly T index:
Month  T index
Sep      109
Oct      89
Nov      89


2. FORECAST (05 OCTOBER - 07 OCTOBER)
Date   T index  Conditions       MUFs                              
05 Oct    80    Fair-normal      Depressed 15 to 20%/near predicted 
                                 monthly values
06 Oct   110    Normal-fair      Near predicted monthly values 
                                 to 15% enhanced    
07 Oct   110    Normal-fair      Near predicted monthly values 
                                 to 15% enhanced   

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 04-Oct were near predicted values to 40% enhanced. 
Spread F was observed at Hobart and Canberra during local night 
hours. Australian region MUFs have become depressed by 15-30% 
after 04/2200UT. The cause of this ionospheric frequency depression 
is unclear. MUFs are expected to be 15-20% depressed to near 
predicted monthly values for the Australian region for 05-Oct. 
MUFs are expected to be near predicted monthly values to 15% 
enhanced over 06-07 Oct, with mildly degraded conditions during 
local night hours for the southern Australian region.

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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