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

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Fri Dec 26 10:30:51 AEDT 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/25 DECEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 25 DECEMBER AND FORECAST FOR 26 DECEMBER - 28 DECEMBER
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 25 Dec:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 25 Dec: 163/117


1B. SOLAR FORECAST
             26 Dec             27 Dec             28 Dec
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     None expected      None expected      Possible
10.7cm/SSN   165/119            170/124            175/129

COMMENT: Solar activity on UT day 25-Dec was R0 with no solar 
flares. There are currently seven numbered sunspot regions on 
the solar disk. Active regions (AR) 4317 (N11E09, beta) and 4321 
(S11W23, beta) have shown movement but overall not increased 
in complexity. Any signs of a delta spot forming in 4321 have 
decayed. All other sunspot regions are either stable or in decay. 
Solar activity is expected to be R0-R1 over 26-28 Dec. 

No CMEs were observed on UT day 25-Dec. 

S0 solar radiation storm conditions were observed on UT day 25-Dec. 
S0 solar radiation storm conditions are expected over 26-28 Dec. 

The solar wind environment on UT day 25-Dec was mildly disturbed
 due to the continued effects of a coronal hole. The solar wind 
speed ranged from 550 to 650 km/s. The peak total interplanetary 
field strength (IMF, Bt) was 6 nT and the north-south IMF component 
range was +4 to -3 nT. The solar wind is expected to remain enhanced 
on 26-Dec before returning to background levels over 27-28 Dec.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 25 Dec: G0

Estimated Indices 25 Dec : A   K           
   Australian Region       7   22322212
      Cocos Island         5   22222201
      Darwin               8   22322213
      Townsville           9   22323222
      Learmonth           10   32323203
      Alice Springs        7   22322212
      Gingin              11   32323313
      Canberra             8   22322222
      Kennaook Cape Grim   9   33322212
      Hobart               8   23322212    

Estimated Antarctic Regional K Indices 25 Dec :
      Macquarie Island    12   23343311
      Casey               29   46633222
      Mawson              21   34543332

Observed Regional daily pc3 Indices 25 Dec : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            2   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              51   (Unsettled)
      Canberra            29   (Quiet to unsettled)
      Hobart              53   (Unsettled)

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 25 Dec : A 
           Fredericksburg        10
           Planetary             12                         

Observed AFr/Ap Indices 24 Dec :  A   K
           Fredericksburg        19
           Planetary             21   4443 3433     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
26 Dec    10    G0-G1
27 Dec    10    G0
28 Dec    10    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 25-Dec. G0-G2 geomagnetic conditions were observed 
in the Antarctic region. G0 geomagnetic conditions are mostly 
expected over 26-28 Dec, with a chance for isolated periods of 
G1 on 26-Dec due to ongoing coronal hole effects.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
25 Dec      Normal         Normal         Normal-fair    

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
26 Dec      Normal         Normal         Normal-fair
27 Dec      Normal         Normal         Normal
28 Dec      Normal         Normal         Normal

COMMENT: HF radio propagation conditions on UT day 25-Dec were 
mostly normal. HF radio propagation conditions are expected to 
be mostly normal over 26-28 Dec.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
25 Dec   128

Observed Australian Regional MUFs
   Cocos Island Region:
      No data available during local day.
      No data available during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 30% during local night.
   Southern Australian Region:
      Mostly near predicted monthly values.
   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
26 Dec   115    Near predicted monthly values to 20% enhanced
27 Dec   115    Near predicted monthly values to 20% enhanced
28 Dec   115    Near predicted monthly values to 20% enhanced

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region were near predicted values to 30% enhanced on UT day 25-Dec. 
Sporadic-E was observed in Perth over the day. MUFs are expected 
to be near predicted values to 20% enhanced over 26-28 Dec. Sporadic-E 
is still expected in local night hours, but may be on a declining 
trend.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 24 Dec
       Daily Proton Fluence >1 MeV:   2.7E+06
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 2.30E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:16%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.2

DSCOVR Satellite Solar Wind Day Averaged Data for 24 Dec
Speed: 691 km/sec  Density:    2.1 p/cc  Temp:   193000 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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