[Ips-wsgr] ASWFC Weekly Solar and Geophysical Report (03 April 26) issued 0045 UT on 03 Apr 2026 [SEC=OFFICIAL]

Fri Apr 3 11:45:17 AEDT 2026

SUBJ: ASWFC WEEKLY SOLAR AND GEOPHYSICAL REPORT 
ISSUED ON 03 APRIL 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx

1. SUMMARY (27 MARCH - 02 APRIL)
Date     27    28    29    30    31    01    02
10cm    156   162   158   152   141   142   140
AFr       6     8    11    11     8     8  ( 31)
Aaus      4     6     8     6     4     6  ( 25)
T        96    94    84   111   108   116   118

Solar:        Solar flare activity
Geomagnetic:  Geomagnetic activity observed for Australian region.
Frequencies:  Australian ionospheric F2 critical frequencies

27 Mar 
Solar:        R0
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Enhanced by 35% during local day.
      Enhanced by 15% during local night.
   Niue Island Region:
      Enhanced by 30% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Enhanced by 20% during local day.
      Generally near predicted monthly values during
      the local night, with only Darwin enhanced 50%.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

28 Mar 
Solar:        R1, with an M1.3 at 0418UT
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Niue Island Region:
      Enhanced by 45% during local day.
      Enhanced by 25% during local night.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

29 Mar 
Solar:        R0
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Mostly near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 25% over the UT day.

30 Mar 
Solar:        R3, with an X1.5 at 0319UT
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Enhanced by 35% during local day.
      Enhanced by 35% during local night.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
   Southern Australian Region:
      Mostly near predicted monthly values.
      Enhanced by 25% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 25% over the UT day.

31 Mar 
Solar:        R0
Geomagnetic:  G0
Frequencies:  
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
   Niue Island Region:
      Enhanced by 15% during local day.
      Enhanced by 15% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

01 Apr 
Solar:        R0
Geomagnetic:  G0
In the BOM magnetometer data for 01 Apr, a weak (9nT) impulse 
was observed at 1203UT.
Frequencies:  
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 85% during local night.
   Niue Island Region:
      Enhanced by 30% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 35% during local night.
      Enhanced by 20% after local dawn.
   Southern Australian Region:
      Mostly near predicted monthly values.
      Enhanced by 25% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

02 Apr 
Solar:        Moderate, with an M3.5 at 1816UT
Geomagnetic:  G1
Frequencies:  
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Enhanced by 50% during local day.
      Enhanced by 50% during local night.
      Enhanced by 25% after local dawn.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 20% during local night.
   Southern Australian Region:
      Enhanced by 20% during local day.
      Enhanced by 25% during local night.
      Depressed by 30% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

Comment: The R3 flare on 30-Mar was associated with a 
predominately east directed CME which arrived later than 
expected on 01-Apr, inducing only a mild increase in geomagnetic
activity. G2 planetary conditions were observed on 02-Apr,
with the Australian regional geomagnetic field reaching G1. 
The increase in geomagnetic activity was due to the Earth 
entering an coronal hole wind stream a day earlier than expected. 
The southern Australian regional ionosphere became 30% depressed 
after local dawn on 03-Apr. 

2. FORECAST (03 APRIL - 09 APRIL)
Solar: 
R0-R1, with R1 flare activity becoming more likely from 07-Apr
due to the possible return of an active solar region which 
produced R1 flares on its previous transit.

Geomagnetic:  
G1-G2 geomagnetic conditions are expected on 03-Apr due to the 
current influence of the coronal hole wind stream and an anticipated 
glancing blow CME arrival during the second half of the UT day.
G1 conditions are expected for 04-Apr with the chance of G2 periods
early in the UT day. G1 conditions are likely on 09-Apr. G0 
conditions are expected on other days of the week.

Frequencies:  
Southern Australian region MUFs depressed 20 to 30% on 3 Apr and
15% depressed on 04-Apr. MUFs are expected to be near predicted 
monthly values on other days of the week.

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