[Ips-whfpr] ASWFC Weekly Prop. Report (02 April 25) issued 0036 UT on 02 Apr 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC WEEKLY HF PROPAGATION REPORT
ISSUED ON 02 APRIL 2025 
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (26 MARCH - 01 APRIL)
Date   T index   Conditions        
26 Mar  113      Fair              
MUFS:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 25% during local night.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Mostly near predicted monthly values.
   Southern Australian Region:
      Depressed by 20%.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 35% over the UT day.

27 Mar  120      Fair-normal       
MUFS:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
      Enhanced by 35% after local dawn.
   Niue Island Region:
      Enhanced by 15% during local day.
      Enhanced by 50% during local night.
   Northern Australian Region:
      Depressed 15% to near predicted monthly values.
      Enhanced 15% after local dawn.
   Southern Australian Region:
      Depressed 15% to near predicted monthly values.
      Depressed 15% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 40% over the UT day.

28 Mar  131      Normal            
MUFS:
   Cocos Island Region:
      Enhanced by 25% during local day.
      Near predicted monthly values during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Northern Australian Region:
      Mostly near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

29 Mar  143      Normal            
MUFS:
   Cocos Island Region:
      Enhanced by 25% during local day.
      Enhanced by 60% during local night.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 25% during local night.
   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.

30 Mar  136      Normal            
MUFS:
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Enhanced by 35% during local day.
      Enhanced by 55% during local night.
   Northern Australian Region:
      Mostly near predicted monthly values.
   Southern Australian Region:
      Enhanced 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.

31 Mar  150      Normal            
MUFS:
   Cocos Island Region:
      Enhanced by 20-25%.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 25% during local night.
   Southern Australian Region:
      Enhanced 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.
      Proton event in progress, increased absorption observed.

01 Apr  152      Normal            
MUFS:
   Cocos Island Region:
      Enhanced by 25% during local day.
      Enhanced by 65% during local night.
   Niue Island Region:
      Enhanced by 30% during local day.
      Enhanced by 20% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 25% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
      Enhanced by 20% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.
      Proton event in progress, increased absorption observed.

Comment: Southern Australian region MUFs were depressed 26-27 Apr
in association with geomagnetic activity induced by a solar
coronal hole wind stream. Bureau SWN riometers observed
increased absorption up to 2.5db during the interval
01/0300-0900UT in association with an S2-Moderate solar
radiation storm/proton event following an R3 flare on 28-Mar.
This event may have impacted high latitude HF communication.
HF fadeout observed 01/0639-1120UT in association with an R2 flare.



Predicted Monthly T index for April: 115

2. FORECAST (02 APRIL - 08 APRIL) 
MUFS: Southern Australian MUFs may be briefly depressed 
after local dawn on 4-5 Apr and 8 Apr. MUFs near predicted 
monthly values on other days.

Propagation conditions: Fair on 4-5 Apr and possibly 8 Apr. 
Otherwise normal. Isolated SWFs probable during the week.

T index: 135
ASWFC SWF HF Communications Warning 33 was issued on 31 March 
and is current for 1-3 Apr.

3. OUTLOOK (09 APRIL - 09 MAY)
Degraded HF propagation conditions possible:
22-24 Apr,  1-2 May,  5-7 May

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