[Ips-dsgr] ASWFC Daily Report - 26 October 25 issued 2330 UT on 26 Oct 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Mon Oct 27 10:30:51 AEDT 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/26 OCTOBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 26 OCTOBER AND FORECAST FOR 27 OCTOBER - 29 OCTOBER
STATUS INDICATORS SOL:GREEN MAG:** RED ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 26 Oct: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 26 Oct: 124/77
1B. SOLAR FORECAST
27 Oct 28 Oct 29 Oct
Activity R0 R0 R0
Fadeouts None expected None expected None expected
10.7cm/SSN 120/72 120/72 120/72
COMMENT: Solar activity on UT day 26-Oct was at the R0 level,
with no significant flaring activity. There are currently seven
numbered sunspot regions visible on the solar disk. Region AR4269
(S08W20, beta) has seen some growth and East-West extension.
Region AR4266 (N15E06, beta) has seen some mild decay and spot
distribution evolution. All other sunspot regions are either
stable or in decay. Solar activity is expected to be at the R0
level throughout the 27-29 Oct. S0 solar proton conditions were
observed on UT day 26-Oct. S0 solar proton conditions are expected
over 27-29 Oct. No Earth-directed CMEs have been observed. Multiple
CMEs were observed, directed to the North-West in LASCO imagery,
visible in both LASCO and STEREO-A coronagraph imagery. These
CMEs are considered farside events and therefore not geoeffective.
The solar wind speed on UT day 25-Oct declined, ranging from
347 to 450 km/s and is currently near 395 km/s. The peak total
interplanetary magnetic field strength (IMF, Bt) was 7 nT and
the North-South IMF component (Bz) range was -4 to +6 nT. A southern
hemisphere coronal hole is currently crossing the central meridian
and is expected to influence the solar wind speed on 28-Oct.
The solar wind speed is expected to remain near background levels
on 27-Oct, then increase over 28-29 Oct.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 26 Oct: G0
Estimated Indices 26 Oct : A K
Australian Region 3 11220111
Cocos Island 1 11110100
Darwin 4 22120112
Townsville 4 21120122
Learmonth 5 22220211
Alice Springs 3 11120111
Gingin 3 11220201
Canberra 3 11210111
Kennaook Cape Grim 3 12220101
Hobart 3 12210101
Estimated Antarctic Regional K Indices 26 Oct :
Macquarie Island 2 02110001
Casey 15 35431212
Mawson 6 23221201
Observed Regional daily pc3 Indices 26 Oct :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 2 (Quiet)
Canberra 13 (Quiet)
Hobart 6 (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 26 Oct : A
Fredericksburg 5
Planetary 6
Observed AFr/Ap Indices 25 Oct : A K
Fredericksburg 9
Planetary 9 3432 2111
2B. MAGNETIC FORECAST
Date Ap Conditions
27 Oct 6 G0
28 Oct 32 G1
29 Oct 29 G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 26-Oct. A period of G1 was observed in the Antarctic
at Casey. G0 conditions were observed elsewhere in the Antarctic
region. G0 geomagnetic conditions are expected on the 27-Oct
with G1 conditions expected over 28-29 Oct. This is due to the
presence of a coronal hole currently passing through the central
meridian.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
26 Oct Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
27 Oct Normal Normal Normal
28 Oct Fair Fair Fair-poor
29 Oct Fair Fair Fair-poor
COMMENT: HF radio propagation conditions on UT day 26-Oct were
normal. Normal HF conditions are expected on the 27-Oct. Mild
HF depressions are expected over 28-29 Oct due to enhanced geomagnetic
activity due to high speed wind stream effects from a coronal
hole.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
26 Oct 113
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 15% during local day.
Enhanced by 30% during local night.
Enhanced by 20% after local dawn.
Niue Island Region:
Enhanced by 20% during local day.
Enhanced by 20% during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
Southern Australian Region:
Near predicted monthly values.
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
27 Oct 110 Near to 15% above predicted monthly values
28 Oct 90 Near predicted monthly values
29 Oct 60 Depressed 15%/near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 26-Oct were near predicted monthly values in
the southern region and near predicted monthly values to 15%
enhanced during local night in the northern region. MUFs are
expected to be near predicted monthly values to 15% enhanced
on 27-Oct. MUFs are expected to be near monthly predicted values
on the 28-Oct and up to 15% depressed on 29-Oct due to anticipated
high speed wind stream effects from a coronal hole
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 25 Oct
Daily Proton Fluence >1 MeV: 2.1E+05
Daily Proton Fluence >10 MeV: 2.0E+04
Daily Electron Fluence >2 MeV: 2.10E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 4%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B5.5
DSCOVR Satellite Solar Wind Day Averaged Data for 25 Oct
Speed: 438 km/sec Density: 3.0 p/cc Temp: 103000 K Bz: 3 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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