[Ips-dhfpr] ASWFC Daily HF Prop Report - 15 April 25 issued 2331 UT on 15 Apr 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/15 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (15 APRIL) 
Date   T index  Conditions    
15 Apr   112    Normal-poor    

Flares    Max     Fadeout    Freq.  Sectors
  M1.5    1020UT  possible   lower  European
  M1.3    1814UT  possible   lower  East Pacific/
                                    North American

MUFs:
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Enhanced by 25% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Mostly near predicted monthly values.
      Enhanced by 20% after local dawn.
   Southern Australian Region:
      Near predicted monthly values.
      Depressed 15-20% pre-dawn period.
      Depressed 10-15% 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
Mar      126
Apr      115
May      113


2. FORECAST (16 APRIL - 18 APRIL)
Date   T index  Conditions       MUFs                              
16 Apr    95    Poor-fair        Depressed 15 to 20%/near predicted 
                                 monthly values
17 Apr   105    Fair-normal      Depressed 10 to 15%/near predicted 
                                 monthly values    
18 Apr   115    Normal           Near predicted monthly values   

COMMENT: ASWFC Preliminary HF Communications Warning 38 was issued 
on 15 April and is current for 16-17 Apr. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 16-Apr were generally 
near predicted values with depressions of 15-20% observed after 
local dawn for the southeast Australian region. Spread-F was 
observed during pre-dawn hours at Perth and Hobart. The Australian 
region ionospheric response to ongoing geomagnetic activity has 
been limited to depressions of up to 20% during the predawn period, 
with Hobart and Canberra only mildly depressed by 15% after dawn 
this morning. MUFs are expected to be depressed 15-20% at times 
for the southern Australian region on 16-Apr. Northern Australian 
region MUFs are mostly expected to remain near normal.

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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