[Ips-whfpr] ASWFC Weekly Prop. Report (11 June 25) issued 0043 UT on 11 Jun 2025 [SEC=OFFICIAL]

Wed Jun 11 10:43:16 AEST 2025

SUBJ: ASWFC WEEKLY HF PROPAGATION REPORT
ISSUED ON 11 JUNE 2025 
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (04 JUNE - 10 JUNE)
Date   T index   Conditions        
04 Jun   57      Fair-poor         
MUFS:
   Cocos Island Region:
      Enhanced by 45% during local day.
      Enhanced by 20% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 30% during local night.
      Depressed by 20% after local dawn.
   Northern Australian Region:
      Depressed by 25% during local day.
      Depressed by 30% during local night.
   Southern Australian Region:
      Depressed by 35% during local day.
      Depressed by 35% during local night.
      Depressed by 20% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

05 Jun   62      Fair-poor         
MUFS:
   Cocos Island Region:
      Depressed by 15% during local day.
      Depressed by 25% during local night.
   Niue Island Region:
      Depressed by 20% during local day.
      Depressed by 40% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 30% during local night.
   Southern Australian Region:
      Depressed by 20% during local day.
      Depressed by 25% during local night.
      Depressed by 20% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 20% over the UT day.

06 Jun   69      Fair-normal       
MUFS:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Niue Island Region:
      Depressed by 15% during local day.
      Depressed by 20% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 40% during local night.
   Southern Australian Region:
      Depressed by 15% during local day.
      Depressed by 25% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

07 Jun   76      Normal-fair       
MUFS:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
   Niue Island Region:
      Depressed by 20% during local day.
      Depressed by 15% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 30% during local night.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

08 Jun   78      Fair              
MUFS:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Niue Island Region:
      Depressed by 20% during local day.
      Depressed by 25% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 30% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 35% during local night.
      Depressed by 20% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 25% over the UT day.

09 Jun   89      Normal-fair       
MUFS:
   Cocos Island Region:
      Enhanced by 25% during local day.
      Depressed by 20% during local night.
   Niue Island Region:
      Depressed by 20% during local day.
      Depressed by 25% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Southern Australian Region:
      Depressed by 20% during local day.
      Depressed by 25% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 30% over the UT day.

10 Jun   72      Normal            
MUFS:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
   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 30% during local night.
   Southern Australian Region:
      Depressed by 15% during local day.
      Depressed by 30% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 20% over the UT day.
      Frequent sporadic E observed at Mawson and Casey.

Predicted Monthly T index for June: 109

Comment: Degraded HF conditions were observed during the past week, with
southern Australian region MUFs frequently 15-30% depressed, with the 
deepest ionospheric depressions observed on 04-Jun, following CME induced 
geomagnetic storm activity observed during 01-03 Jun. Frequent local night 
spread F was observed on ionograms from Bureau ionosondes located in the 
southern Australian region indicating likely degraded HF conditions during 
local night hours during the past week.

2. FORECAST (11 JUNE - 17 JUNE) 
MUFS: depressed 10-15% for southern Australian region 11-12 Jun. Further
similar mild depressions likely during the interval 14-15 Jun due to mild
geomagnetic activity induced from coronal hole wind streams. Near
predicted monthly values for northern Australian region.

Propagation conditions: Fair 11-15 Jun, particularly during local night
hours for the southern Australian region. SWFs are possible this week.

T index: 90
ASWFC HF Communications Warning 61 was issued on 10 June and 
is current for 10-12 Jun.

3. OUTLOOK (18 JUNE - 18 JULY)
Degraded HF propagation conditions possible:
24-26 Jun,  28-Jun,  11 Jul

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