[Ips-wgr] ASWFC Weekly Geo. Report (23 April 26) issued 0239 UT on 23 Apr 2026 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC WEEKLY GEOPHYSICAL REPORT 
ISSUED ON 23 APRIL 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx

1. SUMMARY (14 APRIL - 22 APRIL)
K indices are in UT (0-24). For conversion to local time:

AEST = UT + 10 hours; ACST = UT + 9.5 hours; AWST = UT + 8 hours
        Australian Region*              
 Date     K-INDICES    A               
 14 Apr   1100 0000    0  
 15 Apr   1100 1111    2  
 16 Apr   0100 0011    1  
 17 Apr   1000 0022    2  
 18 Apr   2454 3332   20  
 19 Apr   3343 2321   13  
 20 Apr   1233 3442   14  
 21 Apr   3312 3431   12  
 22 Apr   1101 1011    2  

*estimated from real time data

NOTE: Indices may have been generated from data obtained in 
cooperation with the following organisations: Geoscience Australia, 
University of Newcastle Space Physics Group, Australian Government 
Antarctic Division and International Center for Space Weather 
Science and Education, Japan.


Geomagnetic conditions in the Australian region reached the G1 level
on 18-Apr due to a coronal hole high speed wind stream. G0 was 
observed on other days.

2. FORECAST (23 APRIL - 23 MAY)
Disturbed Periods: 
29-Apr to 02-May, 06-08 May,  15-18 May.

Best Quiet Periods: 
27 Apr,  04-05 May,  10-14 May, 20-21 May

3. FORECAST FOR HIGH RESOLUTION AEROMAGNETIC SURVEYS
Northern Australian Regions:
 Disturbed Periods: None.
 Best Quiet Periods: 23-Apr to 23-May.

Central Australian Regions:
 Disturbed Periods: None.
 Mildly Disturbed Periods: 29-Apr to 03-May, 08-09 May, 18-May.
 Best Quiet Periods: 23-28 Apr, 04-07 May, 10-17 May, 19-23 May.

Southern Australian Regions:
 Disturbed Periods: 29-Apr to 03-May, 08-09 May, 18-May.
 Best Quiet Periods: 24-28 Apr,  2-7 May,  10-15 May,  17-19 May.


Pc3 pulsations are high frequency (10-45 second period) variations 
of the Earths magnetic field. Daily pc3-indices are the daily sum of 
20 minute pc3-indices for that station and have been shown to be well 
correlated with rejection of high resolution aeromagnetic survey 
flight-line data.

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

Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au