[Ips-dhfpr] ASWFC Daily HF Prop Report - 17 December 23 issued 2330 UT on 17 Dec 2023 [SEC=OFFICIAL]

[Regional Warning Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/17 DECEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (17 DECEMBER) 
Date   T index  Conditions    
17 Dec   111    Normal-fair    

Flares    Max     Fadeout    Freq.  Sectors
  M1.1    2017UT  possible   lower  East Pacific/
                                    North American

MUFs:
   Cocos Island Region:
      Enhanced by 30% during local day.
      Enhanced by 35% during local night.
   Niue Island Region:
      Mostly near predicted monthly values.
      Depressed by 20% after local dawn.
   Northern Australian Region:
      Mostly near predicted monthly values.
      Depressed by 20% after local dawn.
   Southern Australian Region:
      Enhanced by 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 : 10MeV Proton/PCA Event Began at 2335UT 15/12, Ended at 0045UT 16/12

Monthly T index:
Month  T index
Nov      114
Dec      100
Jan      98


2. FORECAST (18 DECEMBER - 20 DECEMBER)
Date   T index  Conditions       MUFs                              
18 Dec    80    Normal           Near predicted monthly values/depressed 
                                 0 to 15%
19 Dec    90    Normal           Near predicted monthly values    
20 Dec   100    Normal           Near predicted monthly values   

COMMENT: ASWFC Preliminary HF Communications Warning 130 was 
issued on 15 December and is current for 17-18 Dec. Maximum usable 
frequencies (MUFs) were near predicted monthly values in the 
Australian region on UT day 17-Dec. Depressions of 20% have been 
observed after local dawn in northern Australian regions due 
to recent geomagnetic activity. MUFs are generally expected to 
be near predicted monthly values over 18-20 Dec. Isolated 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