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

[Regional Warning Centre]

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

1. SUMMARY (19 JULY) 
Date   T index  Conditions    
19 Jul   105    Normal         

Flares    Max     Fadeout    Freq.  Sectors
  M1.4    1057UT  possible   lower  European
  M3.8    1725UT  possible   lower  South American/
                                    Atlantic

MUFs:
   Cocos Island Region:
      Enhanced by 25% during local day.
      Enhanced by 15% during local night.
   Niue Island Region:
      Enhanced by 20% during local day.
      Enhanced by 65% during local night.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Scott Base/Davis/Mawson):
      Enhanced by 15% over the UT day.
      Proton event in progress, increased absorption observed.

PCA Event : 10MeV Proton/PCA Event Began at 0145UT 18/07, Ended at 1425UT 18/07

Monthly T index:
Month  T index
Jun      98
Jul      91
Aug      88


2. FORECAST (20 JULY - 22 JULY)
Date   T index  Conditions       MUFs                              
20 Jul    95    Poor             Near predicted monthly values
21 Jul    80    Poor             Near predicted monthly values    
22 Jul    90    Normal           Near predicted monthly values   

COMMENT: ASWFC SWF HF Communications Warning 67 was issued on 
19 July and is current for 19-21 Jul. Maximum usable frequencies 
(MUFs) on UT day 19-Jul in the Australian region were generally 
near predicted monthly values. Spread F was observed during local 
night hours in the southern Australian region. MUFs are expected 
to be generally near predicted monthly values over 20-22 Jul. 
MUF depressions after local dawn are possible over 20-21 Jul 
in southern Australian regions due to anticipated geomagnetic 
activity caused by impacts from CMEs first observed on 17-Jul 
and 18-Jul. 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