[Ips-dhfpr] ASWFC Daily HF Prop Report - 17 July 25 issued 2332 UT on 17 Jul 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/17 JULY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (17 JULY) 
Date   T index  Conditions    
17 Jul    86    Normal         

Flares: none.

MUFs:
   Cocos Island Region:
      Enhanced by 15% during local day.
      Depressed by 45% during local night.
      Depressed by 20% after local dawn.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
   Northern Australian Region:
      Depressed by 15% during local day.
      Depressed by 15% during local night.
      Depressed by 20% after local dawn.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 20% over the UT day.

PCA Event : No event.

Monthly T index:
Month  T index
Jun      79
Jul      104
Aug      102


2. FORECAST (18 JULY - 20 JULY)
Date   T index  Conditions       MUFs                              
18 Jul    80    Normal           Depressed 10 to 20%/near predicted 
                                 monthly values
19 Jul    82    Normal           Depressed 10 to 15%/near predicted 
                                 monthly values    
20 Jul    85    Normal           Depressed 10 to 15%/ near predicted 
                                 monthly values   

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region were near predicted values to 15-20% depressed. Spread-F 
was observed during local night hours at Hobart and Learmonth. 
Sporadic-E was also observed at Darwin, Learmonth, Niue and Townsville 
over the UT day. MUFs are expected to be similar over the UT 
day 18-Jul and then slowly improving to 10-15% depressed over 
19-20 Jul.

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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