[Ips-dhfpr] ASWFC Daily HF Prop Report - 05 August 23 issued 2330 UT on 05 Aug 2023 [SEC=OFFICIAL]

[Regional Warning Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/05 AUGUST 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (05 AUGUST) 
Date   T index  Conditions    
05 Aug   133    Fair-poor      

Flares    Max     Fadeout    Freq.  Sectors
  M1.6    0723UT  possible   lower  Mid East/Indian
  M2.1    0936UT  possible   lower  Mid East/Indian
  X1.6    2222UT  probable   all    East Pacific/
                                    North American

MUFs:
   Cocos Island Region:
      Enhanced by 15% during local day.
      Depressed by 30% during local night.
   Niue Island Region:
      Enhanced by 50% during local day.
      Enhanced by 20% during local night.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Enhanced by 20% during local day.
      Enhanced by 15% during local night.
      Depressed by 20% after local dawn.
   Southern Australian Region:
      Enhanced by 35% during local day.
      Near predicted monthly values during local night.
   Antarctic Region (Casey/Scott Base/Davis/Mawson):
      Depressed by 25% over the UT day.

PCA Event : 10MeV Proton/PCA Event Began at 1105UT 05/08, Ended at 2000UT 05/08

Monthly T index:
Month  T index
Jul      103
Aug      88
Sep      84


2. FORECAST (06 AUGUST - 08 AUGUST)
Date   T index  Conditions       MUFs                              
06 Aug    90    Fair             Near predicted monthly values 
                                 to 20% depressed
07 Aug   100    Fair             Near predicted monthly values 
                                 to 15% depressed    
08 Aug   105    Fair             Near predicted monthly values   

COMMENT: ASWFC HF Communications Warning 75 was issued on 5 August 
and is current for 5-6 Aug. ASWFC SWF HF Communications Warning 
76 was issued on 5 August and is current for 6-8 Aug. Maximum 
usable frequencies (MUFs) on UT day 05-Aug began enhanced during 
local morning hours but became depressed by 20% during local 
night and dawn hours. Significant sporadic-E was observed in 
Brisbane, Hobart, Niue Island, Cocos Islands and Darwin during 
local night hours. Significant spread-F was observed at Canberra 
and Hobart during local night hours. Weak to no ionospheric signals 
were observed at Darwin, Hobart and Niue island during local 
night hours. MUFs are expected to be depressed up to 20% before 
recovering to normal by the end of 06-Aug. Further mild degradations 
may be observed on 07-Aug due to a glancing blow of a CME first 
observed on 04-Aug, carrying into 08-Aug. Shortwave fadeouts 
are 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