[Ips-dhfpr] ASWFC Daily HF Prop Report - 23 June 25 issued 2330 UT on 23 Jun 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/23 JUNE 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (23 JUNE) 
Date   T index  Conditions    
23 Jun    74    Normal-fair    

Flares: none.

MUFs:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
      Depressed by 25% after local dawn.
   Niue Island Region:
      Depressed by 15% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Depressed by 15% during local day.
      Depressed by 30% during local night.
      Depressed by 20% after local dawn.
   Southern Australian Region:
      Depressed by 20% during local day.
      Near predicted monthly values during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 20% over the UT day.
      Sporadic E and spread F frequently observed.

PCA Event : No event.

Monthly T index:
Month  T index
May      94
Jun      109
Jul      107


2. FORECAST (24 JUNE - 26 JUNE)
Date   T index  Conditions       MUFs                              
24 Jun    90    Normal-fair      Depressed 10 to 15%/near predicted 
                                 monthly values
25 Jun    80    Fair             Depressed 10 to 15%/near predicted 
                                 monthly values    
26 Jun    65    Normal-fair      Depressed 15 to 20%/near predicted 
                                 monthly values   

COMMENT: ASWFC HF Communications Warning 67 was issued on 21 
June and is current for 22-24 Jun. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 23-Jun were generally 
15 to 30% depressed. Spread F was observed at Canberra, Townsville, 
Hobart and Norfolk Island during local hight hours. Antarctic 
HF conditions were degraded. MUFs are expected to be 10-15% depressed 
to near predicted monthly values 24-25 Jun, with degraded HF 
conditions for the southern Australian region on 25-Jun during 
local night hours due to expected geomagnetic activity from a 
coronal hole wind stream. Southern Australian region MUFs are 
expected to be 15 to 20% depressed on 26-Jun.

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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