[Ips-dhfpr] ASWFC Daily HF Prop Report - 19 September 23 issued 2330 UT on 19 Sep 2023 [SEC=OFFICIAL]

[Regional Warning Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/19 SEPTEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (19 SEPTEMBER) 
Date   T index  Conditions    
19 Sep    66    Normal         

Flares    Max     Fadeout    Freq.  Sectors
  M1.1    0355UT  possible   lower  E. Asia/Aust.
  M1.8    0938UT  possible   lower  Mid East/Indian
  M4.0    2014UT  possible   lower  East Pacific/
                                    North American

MUFs:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Southern Australian Region:
      Depressed by 35% during local day.
      Depressed by 15% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 40% over the UT day.

PCA Event : No event.

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


2. FORECAST (20 SEPTEMBER - 22 SEPTEMBER)
Date   T index  Conditions       MUFs                              
20 Sep    80    Normal           Depressed 15 to 25%/near predicted 
                                 monthly values
21 Sep    90    Normal           10 to 15% below predicted monthly 
                                 values    
22 Sep    85    Normal           Near predicted monthly values   

COMMENT: ASWFC HF Communications Warning 95 was issued on 19 
September and is current for 19-21 Sep. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 19-Sep were near predicted 
values to 35% depressed. Spread-F was observed at Hobart and 
Canberra, and sporadic-E was observed at Brisbane. Degraded HF 
propagation conditions were observed in high latitudes. MUFs 
are expected to be 15-25% depressed on 20-Sep before beginning 
to recover to near predicted values on 21-Sep. Some further degradations 
may be observed late on 22-Sep due to some anticipated geomagnetic 
activity from a coronal hole.

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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