[Ips-dhfpr] ASWFC Daily HF Prop Report - 13 September 25 issued 2330 UT on 13 Sep 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/13 SEPTEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (13 SEPTEMBER) 
Date   T index  Conditions    
13 Sep    77    Normal-fair    

Flares: none.

MUFs:
   Cocos Island Region:
      No data available during local day.
      No data available during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Northern Australian Region:
      Mostly near predicted monthly values.
   Southern Australian Region:
      Mostly 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
Aug      96
Sep      92
Oct      90


2. FORECAST (14 SEPTEMBER - 16 SEPTEMBER)
Date   T index  Conditions       MUFs                              
14 Sep    85    Normal           Near predicted monthly values
15 Sep    80    Normal-fair      Near predicted monthly values 
                                 to 10-20% depressed    
16 Sep    75    Normal-fair      Near predicted monthly values 
                                 to 10-20% depressed   

COMMENT: ASWFC Preliminary HF Communications Warning 83 was issued 
on 12 September and is current for 15-16 Sep. Maximum usable 
frequencies (MUFs) on UT day 13-Sep were mostly near predicted 
values. Sporadic-E was observed in Townsville during local night 
hours and spread-F was observed in Hobart during local dawn hours. 
MUFs are expected to be near predicted values on 14-Sep. MUFs 
may become 10-20% depressed over 15-16 Sep, especially during 
local night hours, due to expected coronal hole activity.

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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