[Ips-dhfpr] ASWFC Daily HF Prop Report - 11 December 25 issued 2330 UT on 11 Dec 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/11 DECEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (11 DECEMBER) 
Date   T index  Conditions    
11 Dec   117    Normal-fair    

Flares    Max     Fadeout    Freq.  Sectors
  M4.4 10/2208UT  possible   lower  East Pacific/
                                    North American

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

PCA Event : No event.

Monthly T index:
Month  T index
Nov      103
Dec      89
Jan      89


2. FORECAST (12 DECEMBER - 14 DECEMBER)
Date   T index  Conditions       MUFs                              
12 Dec   110    Normal-fair      Near predicted monthly values
13 Dec   110    Normal-fair      Near predicted monthly values    
14 Dec   110    Normal-fair      Near predicted monthly values   

COMMENT: Maximum usable frequencies (MUFs) were near predicted 
monthly values to 20% enhanced during UT day 11-Dec for the Australia 
region, with near predicted monthly values seen in the Antarctic 
region. Low frequency sporadic-E was observed in the southern 
Australian region and Niue Island, with spread F also observed 
in Hobart during local night hours. MUFs are forecast to trend 
towards near predicted monthly values throughout 12-Dec, due 
to the ongoing geomagnetic activity. These conditions will remain 
over 13-14 Dec as the Earth makes a connection to a coronal hole 
high speed wind stream. Sporadic-E during local night hours may 
be observed. Shortwave fadeouts are possible.

----------------------------------------------------------
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