[Ips-wgr] ASWFC Weekly Geo. Report (04 December 25) issued 0129 UT on 04 Dec 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC WEEKLY GEOPHYSICAL REPORT 
ISSUED ON 04 DECEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx

1. SUMMARY (25 NOVEMBER - 03 DECEMBER)
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               
 25 Nov   3335 4433   22  
 26 Nov   3333 5322   17  
 27 Nov   2233 4323   13  In the BOM magnetometer data for 27 
                          Nov, a weak (18nT) impulse was observed 
                          at 1200UT.
 28 Nov   3234 3332   14  
 29 Nov   2333 3323   13  
 30 Nov   3222 1222    7  
 01 Dec   2221 3211    6  
 02 Dec   2221 1222    6  
 03 Dec   1123 5445   22  

*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.


In the Australian regional field G1 periods were observed on
25-Nov, 26-Nov and 03-Dec in association with coronal hole
high speed solar wind streams. Planetary G3 conditions were 
observed 03/1800-2100UT. Planetary G1 conditions were observed
on 25 Nov and 27-Nov.

2. FORECAST (04 DECEMBER - 03 JANUARY)
Disturbed Periods: 
4-5 Dec, 21-23 Dec, 30 Dec - 01 Jan.

Best Quiet Periods: 
 8-12 Dec, 14-17 Dec, 19-Dec, 28-Dec.

3. FORECAST FOR HIGH RESOLUTION AEROMAGNETIC SURVEYS
Northern Australian Regions:
 Mildly Disturbed Periods: 22-23 Dec
 Best Quiet Periods: 8-11 Dec, 15-20 Dec 28-30 Dec

Central Australian Regions:
 Disturbed Periods: 22-23 Dec
 Mildly disturbed: 04-05 Dec, 12-Dec, 21-Dec, 24-26 Dec
 Best Quiet Periods: 8-10 Dec, 16-19 Dec and 29-Dec.

Southern Australian Regions:
 Disturbed Periods: 04-05 Dec, 12-13 Dec, 21-27 Dec.
 Best Quiet Periods: 9-10 Dec, 16-19 Dec and 29-Dec.


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