[Ips-dsgr] ASWFC Daily Report - 30 October 25 issued 2330 UT on 30 Oct 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Fri Oct 31 10:30:43 AEDT 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/30 OCTOBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 30 OCTOBER AND FORECAST FOR 31 OCTOBER - 02 NOVEMBER
STATUS INDICATORS SOL:GREEN   MAG:** YELLOW **     ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 30 Oct:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 30 Oct: 120/72


1B. SOLAR FORECAST
             31 Oct             01 Nov             02 Nov
Activity     R0                 R0                 R0
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   120/72             130/84             130/84

COMMENT: Solar activity on UT day 30-Oct was at the R0 level, 
with one low level C-class flare observed. There are currently 
five numbered sunspot regions visible on the solar disk. AR4267 
(N08W21, beta) is the largest region on the disk and has decayed 
over the UT day. Newly numbered AR4271 (S09E60, alpha) is stable. 
All other sunspot regions are either stable or in decay. Solar 
activity is expected to be at the R0 level over 31-Oct to 02-Nov. 
S0 solar proton conditions were observed on UT day 30-Oct. S0 
solar proton conditions are expected over 31-Oct to 02-Nov. Several 
CMEs were observed over the UT day. A broad northeast-directed 
CME was observed, visible in LASCO C2 coronagraph imagery from 
30/0426UT. This CME is considered a farside event and not geoeffective. 
A filament eruption was observed, visible in GOES SUVI imagery 
beginning at 30/0810UT centred near N23W31. A subsequent associated 
low velocity CME was observed, visible in STEREO-A coronagraph 
imagery from 30/1153UT. Modelling indicates this CME may contain 
a minor Earth-directed component, however it is not considered 
significant. All other CMEs observed on 30-Oct are not considered 
geoeffective. The solar wind speed on UT day 30-Oct increased, 
ranging from 475 to 640 km/s and is currently near 640 km/s. 
The peak total interplanetary magnetic field strength (IMF, Bt) 
was 16 nT and the north-south IMF component (Bz) range was -15 
to +12 nT. A sustained period of southward IMF conditions was 
observed over the interval 30/0606-0855UT. A second period of 
southward IMF conditions was observed over the interval 30/0948-1150UT. 
The solar wind speed is expected to remain elevated over 31-Oct 
to 02-Nov due to ongoing coronal hole high speed wind stream 
effects.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 30 Oct: G1

Estimated Indices 30 Oct : A   K           
   Australian Region      24   33355433
      Cocos Island        16   33244323
      Darwin              21   33344434
      Townsville          22   33345433
      Learmonth           28   43355533
      Alice Springs       21   33345423
      Gingin              25   42355433
      Canberra            22   33354433
      Kennaook Cape Grim  27   33355533
      Hobart              27   33355533    

Estimated Antarctic Regional K Indices 30 Oct :
      Macquarie Island    51   34467643
      Casey               45   56655334
      Mawson              49   55555546

Observed Regional daily pc3 Indices 30 Oct : 
      Darwin               4   (Quiet)
      Townsville          17   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              26   (Quiet to unsettled)
      Canberra            33   (Quiet to unsettled)
      Hobart              41   (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 30 Oct : A 
           Fredericksburg        27
           Planetary             36                         

Observed AFr/Ap Indices 29 Oct :  A   K
           Fredericksburg        15
           Planetary             20   3333 3444     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
31 Oct    22    G1
01 Nov    16    G0, chance of G1
02 Nov    10    G0

COMMENT: G1 geomagnetic conditions were observed in the Australian 
and planetary regions on UT day 30-Oct. Mostly G2 geomagnetic 
conditions were observed in the Antarctic region, with an isolated 
period of G3 observed at Macquarie Island. Geomagnetic activity 
was associated with Earth's entry into a coronal hole high speed 
wind stream. G1 geomagnetic conditions are expected on 31-Oct 
due to ongoing coronal hole effects. G0 geomagnetic conditions 
are expected over 01-02 Nov, with a chance of G1 on 01-Nov.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
30 Oct      Normal         Fair           Normal-fair    

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
31 Oct      Normal         Normal-fair    Fair
01 Nov      Normal         Normal-fair    Fair
02 Nov      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions on UT day 30-Oct were 
mostly normal, with fair conditions observed at mid latitudes. 
Normal to fair conditions are expected on 31-Oct due to anticipated 
geomagnetic activity. Mostly normal conditions are expected over 
01-02 Nov.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
30 Oct    77

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Depressed by 20% during local day.
      Near predicted monthly values during local night.
      Depressed by 35% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

Monthly T index:
Month  T index
Sep      109
Oct      89
Nov      89

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
31 Oct    65    Depressed 15%/near predicted monthly values
01 Nov    80    Near predicted monthly values
02 Nov    80    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) on UT day 30-Oct were 
near predicted monthly values in northern Australia. MUFs were 
depressed by 20-35% in southern Australian regions. Spread F 
was observed at Hobart during local night hours. MUFs are expected 
to be near predicted monthly values to 15% depressed on 31-Oct, 
returning to near predicted monthly values over 01-02 Nov.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 29 Oct
       Daily Proton Fluence >1 MeV:   1.4E+06
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 1.20E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B3.8

DSCOVR Satellite Solar Wind Day Averaged Data for 29 Oct
Speed: 470 km/sec  Density:    5.3 p/cc  Temp:   170000 K  Bz:   0 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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