[Ips-dsgr] ASWFC Daily Report - 02 October 25 issued 2330 UT on 02 Oct 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Fri Oct 3 09:30:47 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/02 OCTOBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 02 OCTOBER AND FORECAST FOR 03 OCTOBER - 05 OCTOBER
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 02 Oct: R1
Flares Max Fadeout Freq. Sectors
M1.2 0209UT possible lower E. Asia/Aust.
Observed 10.7 cm flux/Equivalent Sunspot Number for 02 Oct: 167/121
1B. SOLAR FORECAST
03 Oct 04 Oct 05 Oct
Activity R0-R1, chance R2 R0-R1, chance R2 R0-R1, chance R2
Fadeouts Possible Possible Possible
10.7cm/SSN 185/138 180/133 175/129
COMMENT: Solar activity on UT day 2-Oct was R1 with an isolated
M1.2 solar flare from AR4230 (S10W3, beta). There are currently
nine numbered sunspot regions on the solar disk. AR4232 (N05W03,
beta-gamma) and AR4233 (N19E00, beta) have shown some slight
growth in size over the past day, although appear to be simplifying
their magnetic polarities. All other sunspot regions are either
stable or in decay. Solar activity is expected to be R0-R1 with
a chance for R2 over 3-5 Oct.
A small and weak CME was observed from 0812 UT directed mostly to
the solar northeast. The likely origin of this event was from minor
C flaring from near AR4232 near the centre disk, however this CME
is not expected to impact the Earth significantly. No other noteworthy
CMEs were observed on UT day 2-Oct.
S0 solar radiation storm conditions were observed on UT day 2-Oct.
S0 solar radiation storm conditions are expected over 3-5 Oct.
The solar wind environment on UT day 2-Oct was mostly steady,
although enhanced. The solar wind speed was relatively
fast and ranged from 700 to 864 km/s, and is currently on a steady
trend near 750 km/s. On the other hand, the total interplanetary
field strength (IMF, Bt) was near background levels and peaked
at 10 nT. The north-south IMF component range (Bz) was +5 to
-9nT with several intermittent periods of southward Bz. It is
unclear, but likely, that the extended coronal hole in the southern
solar hemisphere has made and earlier than anticipated connection;
it is possible solar wind conditions may begin to ease over
3-4 Oct. Conditions are likely to be trending down on 5-Oct.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 02 Oct: G1
Estimated Indices 02 Oct : A K
Australian Region 21 44353233
Cocos Island 14 33342133
Darwin 18 44343233
Townsville 18 44343233
Learmonth 25 54354233
Alice Springs 17 34343233
Gingin 26 5435423-
Canberra 19 34353233
Kennaook Cape Grim 22 44354233
Hobart 24 44454233
Estimated Antarctic Regional K Indices 02 Oct :
Macquarie Island 46 45575343
Casey 32 45443264
Mawson 106 88555276
Observed Regional daily pc3 Indices 02 Oct :
Darwin 2 (Quiet)
Townsville 0 (Quiet)
Learmonth 4 (Quiet)
Alice Springs 0 (Quiet)
Gingin 46 (Unsettled)
Canberra 56 (Unsettled)
Hobart 88 (Minor storm)
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 Oct : A
Fredericksburg 36
Planetary 51
Observed AFr/Ap Indices 01 Oct : A K
Fredericksburg 25
Planetary 50 5554 6564
2B. MAGNETIC FORECAST
Date Ap Conditions
03 Oct 22 G0-G1, chance G2
04 Oct 14 G0-G1, chance G2
05 Oct 10 G0-G1
COMMENT: ASWFC Geomagnetic Warning 76 was issued on 2 October
and is current for 2-4 Oct. G1 geomagnetic conditions were observed
in the Australian region on UT day 2-Oct. G3-G4 geomagnetic conditions
were observed in the Antarctic region. G3 geomagnetic conditions
were briefly observed on the planetary scale. The source of the
disturbance was due to ongoing high speed solar wind coupled
with brief periods of southward Bz. It was possible there was
early connection to the extended coronal hole in the southern
solar hemisphere contributing to the solar wind speed. Conditions
are generally expected to be on a declining trend, with G0-G1
geomagnetic conditions possible over 3-4 Oct with a chance for
isolated periods of G2. G0-G1 geomagnetic conditions possible
on 5-Oct.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
02 Oct Normal-fair Normal-fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
03 Oct Normal-fair Normal-fair Fair
04 Oct Normal-fair Normal Normal-fair
05 Oct Normal-fair Normal Normal
COMMENT: Widespread depressions were observed globally to ionospheric
maximum usable frequencies on UT day 2-Oct, particularly in the
northern hemisphere. Conditions were degraded, particularly in
the first half of the UT day, but beginning to improve by the
end. Equatorial and polar scintillation was observed. HF radio
propagation conditions are expected to still be mildly degraded
over 3- Oct, but on an improving trend.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
02 Oct 104
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 30% during local day.
Near predicted monthly values during local night.
Niue Island Region:
Enhanced by 40% during local day.
Enhanced by 30% during local night.
Enhanced by 30% after local dawn.
Northern Australian Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Enhanced by 20% after local dawn.
Southern Australian Region:
Depressed by 20% during local day.
Depressed by 15% during local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 20% 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
03 Oct 95 Near predicted monthly values to 25% depressed
04 Oct 90 Near predicted monthly values to 25% depressed
05 Oct 90 Near predicted monthly values to 25% depressed
COMMENT: ASWFC HF Communications Warning 89 was issued on 2 October
and is current for 2-4 Oct. Maximum usable frequencies (MUFs)
in the Australian region on UT day 2-Oct were enhanced by 20
in the northern regions and depressed by 20 in the southern regions.
Sporadic-E was observed in Townsville, Hobart and Niue during
local night hours. Conditions were degraded in Hobart. MUFs are
expected to be near predicted values to 2 depressed over 3-5
Oct, but on an improving trend. Conditions are likely to be mildly
degraded during local night hours.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 01 Oct
Daily Proton Fluence >1 MeV: 2.9E+06
Daily Proton Fluence >10 MeV: 1.7E+04
Daily Electron Fluence >2 MeV: 7.30E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 9%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.7
DSCOVR Satellite Solar Wind Day Averaged Data for 01 Oct
Speed: 723 km/sec Density: 1.6 p/cc Temp: 332000 K Bz: -2 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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