[Ips-dsgr] ASWFC Daily Report - 03 October 25 issued 2333 UT on 03 Oct 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sat Oct 4 09:33:24 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/03 OCTOBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 03 OCTOBER AND FORECAST FOR 04 OCTOBER - 06 OCTOBER
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 03 Oct: R1
Flares Max Fadeout Freq. Sectors
M1.5 0523UT possible lower E. Asia/Aust.
M1.2 1436UT possible lower South American/
Atlantic
Observed 10.7 cm flux/Equivalent Sunspot Number for 03 Oct: 170/124
1B. SOLAR FORECAST
04 Oct 05 Oct 06 Oct
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 170/124 165/119 165/119
COMMENT: Solar activity on UT day 03-Oct was R1. Solar region
AR4236 (N12W21, beta-gamma) produced an M1.5 at 03/0523UT and
solar region AR4238 (S16W76, beta) produced an M1.2 flare at
03/1436UT. Solar region AR4236 began to show decay toward the
end of the UT day and AR4238 is also showing decay as it begins
to rotate over the southwest solar limb. Solar region AR4232
(N05W14, beta-gamma) just to the south of AR4236 showed decay
in its trailer spots. Another region of recent interest AR4230
(S10W74, beta) is decaying as it approaches the southwest solar
limb. Two smaller regions in the north east solar quadrant AR2441
(N16E23, beta) and AR4243 (N20E60, beta) are growing. There are
currently nine numbered sunspot regions on the solar disk. All
other sunspot regions are either stable or in decay. An 8 degree
long solar filament visible in Learmonth GONG H-alpha imagery
located at N15E12 erupted at 03/0509UT. Another more minor fainter
slower partial filament eruption was observed from 03/1925UT
located at S22E25 visible in Big Bear GONG H-alpha imagery. Solar
plasma arch movement was observed in GOES SUVI from 03/1736UT
on the southwest limb at solar latitude S15. A solar radio type
II sweep, indicating a plasma sock wave, was associated with
the M1.2 flare from AR4238. Solar activity is expected to be
R0-R1 over 04-06 Oct. No significant Earth directed CMEs have
been observed. In LASCO C2 imagery, an in progress east directed
CME was observed from 03/0012UT, two faint east directed CMEs
were observed from 03/0712UT and 03/1700UT. These eastward CMEs
are directed behind the Earth. The faint eastward CME at 03/0712UT
is likely to be associated with the small energetic filament
eruption at 03/0509UT (N15E12).A faint westward CME was observed
from 03/1748UT.This westward CME has been paired activity on
the southwest solar limb, and is expected to pass ahead of the
Earth. S0 solar radiation storm conditions were observed on UT
day 03-Oct. S0 solar radiation storm conditions are expected
over 04-06 Oct. A broad coronal hole spans across the southern
solar hemisphere and is currently elevating the solar wind speed.
The solar wind speed is declining and ranged from 790 to 570
km/s, and is currently near 570 km/s. The total interplanetary
field strength (IMF, Bt) peaked at 6 nT. The north-south IMF
component range (Bz) was +5 to -5 nT. Though the magnitude of
the IMF Bt was not very strong, the Bz component frequently fluctuated
southward over the UT day. The solar wind speed is expected to
further decline as the broad coronal hole rotates further west
of the solar central meridian.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 03 Oct: G0
Estimated Indices 03 Oct : A K
Australian Region 17 33443332
Cocos Island 12 23333331
Darwin 16 33433333
Townsville 17 33443332
Learmonth 17 33433342
Alice Springs 14 23433332
Gingin 20 33344442
Canberra 17 33443332
Kennaook Cape Grim 21 33454332
Hobart 22 34454332
Estimated Antarctic Regional K Indices 03 Oct :
Macquarie Island 43 45665442
Casey 23 44543333
Mawson 46 65644553
Observed Regional daily pc3 Indices 03 Oct :
Darwin 2 (Quiet)
Townsville 0 (Quiet)
Learmonth 4 (Quiet)
Alice Springs 0 (Quiet)
Gingin 63 (Active)
Canberra 51 (Unsettled)
Hobart 65 (Active)
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 03 Oct : A
Fredericksburg 23
Planetary 32
Observed AFr/Ap Indices 02 Oct : A K
Fredericksburg 30
Planetary 45 5755 4254
2B. MAGNETIC FORECAST
Date Ap Conditions
04 Oct 14 G0-G1
05 Oct 12 G0, chance G1
06 Oct 8 G0
COMMENT: ASWFC Geomagnetic Warning 76 was issued on 2 October
and is current for 2-4 Oct. G0 geomagnetic conditions were observed
in the Australian region on UT day 03-Oct. G1-G2 geomagnetic
conditions were observed in the Antarctic region. G1 geomagnetic
conditions were observed on the planetary scale. The recent disturbance
is due to the ongoing influence of a coronal hole high speed
wind stream. Geomagnetic activity is expected to slowly decline
with periods of G1 conditions possible over 04-05-Oct.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
03 Oct Normal Fair-normal Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
04 Oct Normal Fair-normal Fair
05 Oct Normal Normal Normal-fair
06 Oct Normal Normal Normal-fair
COMMENT: HF radio propagation conditions were fair at middle
to high latitudes on 03-Oct. HF conditions are expected to gradually
improve, with fair conditions at middle to high latitudes on
04-Oct, then fair to normal for 05-05 Oct.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
03 Oct 114
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 50% during local day.
Enhanced by 45% during local night.
Niue Island Region:
Enhanced by 50% during local day.
Enhanced by 15% during local night.
Enhanced by 20% after local dawn.
Northern Australian Region:
Enhanced by 15% during local day.
Enhanced by 15% during local night.
Enhanced by 20% after local dawn.
Southern Australian Region:
Generally near predicted monthly
values during local day, with MUFs
at Hobart depressed 20% and MUFs at Perth
enhanced by 30%.
Depressed by 15% during local night.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values 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
04 Oct 105 Near predicted monthly values to 15% enhanced
05 Oct 105 Near predicted monthly values to 15% enhanced
06 Oct 105 Near predicted monthly values to 15% enhanced
COMMENT: ASWFC HF Communications Warning 89 was issued on 2 October
and is current for 2-4 Oct. ASWFC SWF HF Communications Warning
90 was issued on 3 October and is current for 3-4 Oct. Maximum
usable frequencies (MUFs) in the Australian region on UT day
03-Oct were variable. MUF enhancements of up to by 20% were observed
in the northern Australian region. MUFs at Hobart were depressed
by up to 20% during the local day, with other southern region
sites near predicted monthly values. MUFs at Perth were 30% enhanced
during the local day. Spread F was observed at Hobart and Canberra
during local night hours. MUFs are expected to be near predicted
monthly values to 15% enhanced over 04-06 Oct.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 02 Oct
Daily Proton Fluence >1 MeV: 3.3E+06
Daily Proton Fluence >10 MeV: 1.7E+04
Daily Electron Fluence >2 MeV: 1.20E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:12%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.4
DSCOVR Satellite Solar Wind Day Averaged Data for 02 Oct
Speed: 738 km/sec Density: 0.8 p/cc Temp: 330000 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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