[Ips-dhfpr] ASWFC Daily HF Prop Report - 22 May 25 issued 2330 UT on 22 May 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/22 MAY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (22 MAY) 
Date   T index  Conditions    
22 May    88    Normal-fair    

Flares: none.

MUFs:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 30% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 35% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 15% 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
Apr      123
May      113
Jun      111


2. FORECAST (23 MAY - 25 MAY)
Date   T index  Conditions       MUFs                              
23 May    90    Normal-fair      Depressed 15%/near predicted 
                                 monthly values
24 May    90    Normal-fair      Depressed 15%/near predicted 
                                 monthly values    
25 May    90    Normal           Depressed 15%/near predicted 
                                 monthly values   

COMMENT: ASWFC SWF HF Communications Warning 50 was issued on 
21 May and is current for 21-23 May. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 22-May were near predicted 
monthly values during local day with depressions of up to 25% 
during local night. Spread F was observed at Hobart, Brisbane 
and Darwin during local night hours. Sporadic E was also observed 
at Hobart and Cocos Islands during local night hours. MUFs are 
expected to be near predicted monthly values to 15% depressed 
over 23-25 May. 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