[Ips-dhfpr] ASWFC Daily HF Prop Report - 09 August 25 issued 2330 UT on 09 Aug 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/09 AUGUST 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (09 AUGUST) 
Date   T index  Conditions    
09 Aug   107    Normal-fair    

Flares    Max     Fadeout    Freq.  Sectors
  M1.6    1621UT  possible   lower  South American/
                                    Atlantic

MUFs:
   Cocos Island Region:
      Enhanced by 20% during local day.
      Enhanced by 20% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 35% over the UT day.

PCA Event : No event.

Monthly T index:
Month  T index
Jul      88
Aug      96
Sep      93


2. FORECAST (10 AUGUST - 12 AUGUST)
Date   T index  Conditions       MUFs                              
10 Aug    80    Normal-fair      Near predicted monthly values/depressed 
                                 5 to 15%
11 Aug    90    Normal-fair      Near predicted monthly values    
12 Aug    90    Normal           Near predicted monthly values   

COMMENT: ASWFC SWF HF Communications Warning 74 was issued on 
8 August and is current for 8-10 Aug. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 08-Aug were near predicted 
monthly values, with enhanced conditions observed in the southern 
Australian region. The exception was Hobart, where depressions 
of up to 30% were observed during local night, significant spread 
F was also observed at Hobart. Sporadic E was observed at Brisbane, 
Townsville, Darwin and Cocos Islands during local night hours. 
MUFs are expected to be near predicted monthly values to depressed 
by up to 25% in the southern Australian region on 10-Aug due 
to recent and expected geomagnetic activity. Conditions are expected 
to recover over 11-12 Aug, with a slight chance of further depressions. 
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