[Ips-dsgr] ASWFC Daily Report - 02 December 25 issued 2330 UT on 02 Dec 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Wed Dec 3 10:30:49 AEDT 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/02 DECEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 02 DECEMBER AND FORECAST FOR 03 DECEMBER - 05 DECEMBER
STATUS INDICATORS SOL:** RED **   MAG:** RED **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 02 Dec:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 02 Dec: 200/152


1B. SOLAR FORECAST
             03 Dec             04 Dec             05 Dec
Activity     R2-R3              R2-R3              R2-R3
Fadeouts     Probable           Probable           Probable
10.7cm/SSN   205/156            210/161            210/161

COMMENT: Solar activity was at the R0 level over the UT day 02-Dec. 
Currently, there are ten numbered sunspot regions. AR4299 (N23E58, 
beta) remains of interest, given it appears to be the same as 
that of AR4274, from the previous solar rotation. This region 
was associated with significant flaring and CME activity. However, 
it has decayed significantly since its previous rotation. However, 
it has seen minor growth in the previous 24 hours. A small, unnumbered 
region has also recently appeared in close proximity to AR4297. 
It is currently located at approximately S02W28 and has been 
analysed to be a beta region. AR4294 (S14E41, beta-delta) remains 
the largest. This region has shown minor growth over the last 
24 hours. AR4298 (S17E22, beta) has also seen the growth of a 
number of trailer spots. All other sunspot regions on the disk 
are either stable or in decay. Solar activity is expected to 
be at the R2-R3 level over 3-5 Dec, due to potential flare activity 
from both AR4294 and AR4299. Solar radiation storm conditions 
were at the S0 level during UT day 02-Dec, and S0 conditions 
are forecast to continue over the period 3-5 Dec. There were 
no Earth-bound Coronal Mass Ejections observed over the past 
UT day. The solar wind environment on UT day 02-Dec was largely 
stable. The solar wind speed ranged from 477 to 378 km/s. The 
peak total interplanetary field strength (IMF, Bt) was 7 nT and 
the north-south IMF component range (Bz) was +4 to -4nT. The 
solar wind speed is expected to increase from 3-Dec due to a 
recurrent coronal hole.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 02 Dec: G0

Estimated Indices 02 Dec : A   K           
   Australian Region       6   22211222
      Cocos Island         3   21100221
      Darwin               6   22111223
      Townsville           6   22221222
      Learmonth            8   22121332
      Alice Springs        5   12211222
      Gingin               8   31221232
      Canberra             6   22211222
      Kennaook Cape Grim   6   22221222
      Hobart               6   13211222    

Estimated Antarctic Regional K Indices 02 Dec :
      Macquarie Island     6   12122222
      Casey               21   45433233
      Mawson              25   34233364

Observed Regional daily pc3 Indices 02 Dec : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             0   (Quiet)
      Hobart               2   (Quiet)

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. 

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.


Estimated AFr/Ap Indices 02 Dec : A 
           Fredericksburg         9
           Planetary             10                         

Observed AFr/Ap Indices 01 Dec :  A   K
           Fredericksburg         9
           Planetary             10   4122 2322     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
03 Dec    11    G0
04 Dec    25    G1
05 Dec    22    G1

COMMENT: G0 geomagnetic conditions were observed across the Australian 
region throughout UT day 02-Dec, with an isolated period of G1 
observed at Casey and similarly, a period of G2 at Mawson. G0 
geomagnetic conditions are expected on the 03-Dec, increasing 
to G1 over 04-05 Dec. This is due to a high speed wind stream 
from an equatorial coronal hole, expected to connect with the 
Earth by 4-Dec.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
02 Dec      Normal         Normal         Normal         

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
03 Dec      Normal         Normal         Normal-fair
04 Dec      Normal         Normal         Fair
05 Dec      Normal-fair    Fair-normal    Fair

COMMENT: HF radio propagation conditions on UT day 02-Dec were 
normal. HF conditions are expected to normal on the 03-Dec. Normal-fair 
conditions are expected in high latitude regions on the 04-Dec. 
Normal-fair conditions are expected on the 05-Dec. This is due 
to the presence of a coronal hole high speed solar wind stream, 
expected to become geoeffective on the 04-Dec. Shortwave fadeouts 
are probable on daylight HF circuits.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
02 Dec   128

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 15% 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.

Monthly T index:
Month  T index
Nov      103
Dec      89
Jan      89

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
03 Dec   115    Near to 15% above predicted monthly values
04 Dec   100    Near predicted monthly values
05 Dec    95    Near predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 114 was issued on 
2 December and is current for 2-4 Dec. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 02-Dec were up to 15% 
enhanced. Niue, Norfolk, Canberra and Hobart, experienced extended 
periods of sporadic-E. MUFs are forecast to continue to be up 
to 15% enhanced on the 03-Dec. MUFs are forecast to be near monthly 
predicted values over 04-05 Dec, due to anticipated geomagnetic 
activity. Shortwave fadeouts are probable on daylight HF circuits.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 01 Dec
       Daily Proton Fluence >1 MeV:   5.3E+06
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 4.1E+08    
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C2.1

DSCOVR Satellite Solar Wind Day Averaged Data for 01 Dec
Speed: 485 km/sec  Density:    1.9 p/cc  Temp:   114000 K  Bz:  -1 nT

(Courtesy Space Weather Prediction Center, Boulder USA)
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Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au



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