[Ips-dhfpr] ASWFC Daily HF Prop Report - 16 May 25 issued 2330 UT on 16 May 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/16 MAY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (16 MAY) 
Date   T index  Conditions    
16 May    89    Normal-fair    

Flares: none.

MUFs:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 25% 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 30% during local night.
      Depressed by 25% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

PCA Event : No event.

Monthly T index:
Month  T index
Apr      123
May      113
Jun      111


2. FORECAST (17 MAY - 19 MAY)
Date   T index  Conditions       MUFs                              
17 May    90    Normal           Depressed 20%/near predicted 
                                 monthly values
18 May    90    Normal-fair      Depressed 20%/near predicted 
                                 monthly values    
19 May    90    Normal-fair      Depressed 20%/near predicted 
                                 monthly values   

COMMENT: ASWFC HF Communications Warning 48 was issued on 16 
May and is current for 17-19 May. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 16-May were depressed 
by 25-30% during local night and were near predicted monthly 
values during local day. Spread F was observed at Hobart, Canberra 
and Brisbane during local night hours. MUFs are expected to be 
near predicted monthly values to 20% depressed over 17-19 May. 
Shortwave fadeouts are probable.

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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