[Ips-dhfpr] ASWFC Daily HF Prop Report - 15 December 23 issued 2331 UT on 15 Dec 2023 [SEC=OFFICIAL]

[Regional Warning Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/15 DECEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (15 DECEMBER) 
Date   T index  Conditions    
15 Dec    82    Normal-fair    

Flares    Max     Fadeout    Freq.  Sectors
  M6.3    0715UT  probable   lower  Mid East/Indian
  M6.9    0734UT  probable   lower  Mid East/Indian

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

PCA Event : No event.

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


2. FORECAST (16 DECEMBER - 18 DECEMBER)
Date   T index  Conditions       MUFs                              
16 Dec   100    Normal-fair      Near predicted monthly values
17 Dec    70    Fair             Near predicted monthly values/depressed 
                                 15 to 30%    
18 Dec    80    Normal           Near predicted monthly values/depressed 
                                 0 to 15%   

COMMENT: ASWFC SWF HF Communications Warning 129 was issued on 
14 December and is current for 14-16 Dec. 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 to 20% depressed in the Australian region on UT 
day 15-Dec. MUFs are expected to be near predicted monthly values 
over 16-18 Dec, with mildly degraded HF conditions possible for 
the southern Australian region during local night hours on 16-Dec 
due to an anticipated weak CME arrival. A further degradation 
in ionospheric conditions is expected for the southern Australian 
region over 17-18 Dec due to anticipated component arrivals of 
CME activity observed on 14-Dec. 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