[Ips-dhfpr] ASWFC Daily HF Prop Report - 20 September 23 issued 2333 UT on 20 Sep 2023 [SEC=OFFICIAL]

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SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/20 SEPTEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (20 SEPTEMBER) 
Date   T index  Conditions    
20 Sep    99    Normal         

Flares    Max     Fadeout    Freq.  Sectors
  M8.2    1419UT  probable   lower  South American/
                                    Atlantic

MUFs:
   Cocos Island Region:
      Enhanced by 30% during local day.
      Depressed by 30% during local night.
   Niue Island Region:
      Mostly near predicted monthly values.
      Enhanced by 30% after local dawn.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Southern Australian Region:
      Near predicted monthly values.
      Depressed 15% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 25% over the UT day.

PCA Event : No event.

Monthly T index:
Month  T index
Aug      115
Sep      96
Oct      93


2. FORECAST (21 SEPTEMBER - 23 SEPTEMBER)
Date   T index  Conditions       MUFs                              
21 Sep    80    Fair-normal      Depressed 10 to 15%/near predicted 
                                 monthly values
22 Sep    95    Normal-fair      Near predicted monthly values    
23 Sep    95    Fair-normal      Near predicted monthly values   

COMMENT: ASWFC SWF HF Communications Warning 96 was issued on 
20 September and is current for 20-22 Sep. ASWFC HF Communications 
Warning 97 was issued on 20 September and is current for 21 Sep 
only. Maximum usable frequencies (MUFs) in the Australian region 
on UT day 20-Sep were mostly near predicted values to 15% enhanced. 
Spread-F was observed at Hobart during local night hours. MUFs 
have been depressed 15% after local dawn this morning for the 
southern Australian region. Mild ionospheric phase scintillation 
(<1 deg.) was observed at Weipa during the interval 20/08-12UT. 
MUFs are expected to be depressed 15% to near predicted monthly 
values on 21-Sep and generally near predicted monthly values 
for 22-23 Sep. Mild degradations may be experienced during local 
night hours on 22-Sep due to anticipated mild geomagnetic activity 
from a coronal hole wind stream. There is a chance for further 
brief mild depressions after local dawn on 23-Sep in the southern 
Australian region. Isolated fadeouts 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