[Ips-whfpr] ASWFC Weekly Prop. Report (22 April 26) issued 0111 UT on 22 Apr 2026 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC WEEKLY HF PROPAGATION REPORT
ISSUED ON 22 APRIL 2026 
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (15 APRIL - 21 APRIL)
Date   T index   Conditions        
15 Apr   61      Fair-normal       
MUFS:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 35% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
      Depressed by 20% after local dawn.
   Northern Australian Region:
      Mostly near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

16 Apr   60      Normal            
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.

17 Apr   66      Fair-normal       
MUFS:
   Cocos Island Region:
      Enhanced by 25% during local day.
      Near predicted monthly values during local night.
      Depressed by 20% after local dawn.
   Niue Island Region:
      Depressed by 15% during local day.
      Depressed by 30% 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.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

18 Apr   90      Fair-normal       
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.
      Enhanced by 30% during local night.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

19 Apr   71      Poor              
MUFS:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 35% during local night.
   Niue Island Region:
      Mostly near predicted monthly values.
      Depressed by 25% after local dawn.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 35% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
      Depressed by 20% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 25% over the UT day.

20 Apr   63      Normal-fair       
MUFS:
   Cocos Island Region:
      Near predicted monthly values during local day.
      No data available during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

21 Apr   34      Fair              
MUFS:
   Cocos Island Region:
      No data available during local day.
      No data available during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 35% during local night.
   Southern Australian Region:
      Depressed by 40% during local day.
      Depressed by 40% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 25% over the UT day.

Predicted Monthly T index for April:  83

2. FORECAST (22 APRIL - 28 APRIL) 
MUFS: MUFs depressed by 10-20% on 22-Apr, recovering by 23-Apr. 
MUFs may become depressed by 10-20% again by 25-Apr. 

Propagation conditions: Mildly degraded on 22-Apr. Normal over 23-24 Apr. 
May become further degraded on 25-Apr. Normal rest of the week. 

T index: 83
ASWFC HF Communications Warning 39 was issued on 22 April and 
is current for 22 Apr only.

3. OUTLOOK (29 APRIL - 29 MAY)
Degraded HF propagation conditions possible:
29-30 Apr and 1-May, 15-18 Mar

PLEASE NOTE:
Space weather conditions can frequently be determined by short 
timescale events that cannot be forecast a week in advance,
particularly at solar maximum.

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