[Ips-dhfpr] ASWFC Daily HF Prop Report - 16 April 26 issued 2330 UT on 16 Apr 2026 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/16 APRIL 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (16 APRIL) 
Date   T index  Conditions    
16 Apr    60    Normal         

Flares: none.

MUFs:
   Cocos Island Region:
      Enhanced by 20% during local day.
      Depressed by 35% during local night.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 30% during local night.
   Southern Australian Region:
      Depressed by 15% during local day.
      Near predicted monthly values 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
Mar      92
Apr      83
May      81


2. FORECAST (17 APRIL - 19 APRIL)
Date   T index  Conditions       MUFs                              
17 Apr    70    Normal-fair      Depressed 10 to 15%/near predicted 
                                 monthly values
18 Apr    45    Fair             Depressed 20 to 30%/near predicted 
                                 monthly values    
19 Apr    30    Fair             Depressed 20 to 30%/near predicted 
                                 monthly values   

COMMENT: ASWFC Preliminary HF Communications Warning 36 was issued 
on 16 April and is current for 18-20 Apr. Maximum Usable Frequencies 
(MUFs) in the Australian region on UT day 16-Apr were depressed 
30% to near predicted monthly values. Depressions of up to 30% 
were observed during local night hours in the northern Australian 
region. The recent ionospheric depressions are not associated 
with geomagnetic activity. Southern Australian region MUFs are 
expected to be 15% depressed to near predicted monthly values 
on 17-Apr. Degraded HF conditions may be experienced for the 
southern Australian region from 18-Apr in association with anticipated 
geomagnetic activity induced by a coronal hole wind stream.

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