[Ips-dhfpr] ASWFC Daily HF Prop Report - 21 December 23 issued 2330 UT on 21 Dec 2023 [SEC=OFFICIAL]

[Regional Warning Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/21 DECEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (21 DECEMBER) 
Date   T index  Conditions    
21 Dec   129    Normal         

Flares    Max     Fadeout    Freq.  Sectors
  M4.2    0538UT  possible   lower  E. Asia/Aust.

MUFs:
   Cocos Island Region:
      Enhanced by 30% during local day.
      Enhanced by 60% during local night.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

PCA Event : No event.

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


2. FORECAST (22 DECEMBER - 24 DECEMBER)
Date   T index  Conditions       MUFs                              
22 Dec   130    Normal           Near to 15% above predicted 
                                 monthly values
23 Dec   130    Normal           Near to 15% above predicted 
                                 monthly values    
24 Dec   130    Normal           Near to 15% above predicted 
                                 monthly values   

COMMENT: ASWFC SWF HF Communications Warning 132 was issued on 
21 December and is current for 21-23 Dec. Maximum usable frequencies 
(MUFs) on UT day 21-Dec in the Australian region were near predicted 
monthly values to 20% enhanced. Sporadic E was observed at several 
Australian sites. MUFs are generally expected to be near predicted 
monthly values to 15% enhanced over 22-24 Dec. Further sporadic 
E can be expected in the Australian region during local night 
hours. 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