[Ips-dhfpr] ASWFC Daily HF Prop Report - 21 September 23 issued 2333 UT on 21 Sep 2023 [SEC=OFFICIAL]

[rwc]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/21 SEPTEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (21 SEPTEMBER) 
Date   T index  Conditions    
21 Sep   105    Normal         

Flares    Max     Fadeout    Freq.  Sectors
  M8.7    1254UT  probable   lower  European

MUFs:
   Cocos Island Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Niue Island Region:
      Enhanced by 20-35%.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 25% during local night.
   Southern Australian Region:
      Depressed 15% during local day.
      Near predicted monthly values 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
Aug      115
Sep      96
Oct      93


2. FORECAST (22 SEPTEMBER - 24 SEPTEMBER)
Date   T index  Conditions       MUFs                              
22 Sep    95    Normal-fair      Near predicted monthly values
23 Sep    95    Normal-fair      Near predicted monthly values    
24 Sep    95    Normal           Near predicted monthly values   

COMMENT: ASWFC SWF HF Communications Warning 96 was issued on 
20 September and is current for 20-22 Sep. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 21-Sep were depressed 
15% during during the local day on the Australian south-east 
coast, with northern Australian region MUFs near predicted values 
to 25% enhanced. The south west coast remained near predicted 
monthly values. Spread-F was observed at Hobart during local 
night hours. MUFs are generally expected to be near predicted 
monthly values over 22-24 Sep. Mild degradations may be experienced 
during local night hours on 22-23 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 23-24 Sep in the southern Australian region. Shortwave fadeouts 
probable.

----------------------------------------------------------
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