[Ips-dhfpr] ASWFC Daily HF Prop Report - 20 July 25 issued 2332 UT on 20 Jul 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/20 JULY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (20 JULY) 
Date   T index  Conditions    
20 Jul    87    Normal         

Flares: none.

MUFs:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 35% during local night.
      Depressed by 30% after local dawn.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

PCA Event : No event.

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


2. FORECAST (21 JULY - 23 JULY)
Date   T index  Conditions       MUFs                              
21 Jul    86    Normal           Near predicted monthly values
22 Jul    88    Normal           Near predicted monthly values    
23 Jul    80    Normal-fair      Depressed 15%/near predicted 
                                 monthly values   

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region were near predicted monthly values during local day and 
depressed by up to 15% during local night. Spread F was observed 
during local night hours at Hobart, Perth, Brisbane and Niue. 
MUFs are expected to be generally near predicted monthly values 
over 21-22 Jul. Conditions are expected to be near predicted 
monthly values to depressed by 15% on 23-Jul due to coronal hole 
high speed wind stream effects.

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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