[Ips-dsgr] ASWFC Daily Report - 27 October 25 issued 2330 UT on 27 Oct 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Tue Oct 28 10:30:47 AEDT 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/27 OCTOBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 27 OCTOBER AND FORECAST FOR 28 OCTOBER - 30 OCTOBER
STATUS INDICATORS SOL:GREEN MAG:** RED ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 27 Oct: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 27 Oct: 121/73
1B. SOLAR FORECAST
28 Oct 29 Oct 30 Oct
Activity R0 R0 R0
Fadeouts None expected None expected None expected
10.7cm/SSN 120/72 120/72 125/78
COMMENT: Solar activity on UT day 27-Oct was at the R0 level,
with no significant flaring activity. There are currently seven
numbered sunspot regions visible on the solar disk. Region AR4270
(S05W00, beta) has recently developed on the disk and has shown
East-West extension. All other regions are either stable or in
decline. S0 solar proton conditions were observed on UT day 27-Oct.
S0 solar proton conditions are expected over 28-30 Oct. No Earth-directed
CMEs have been observed on UT day 27-Oct. Two CMEs were observed,
directed to the North-East 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 27-Oct was largely stable, ranging from 341 to
406 km/s and is currently near 375 km/s. The peak total interplanetary
magnetic field strength (IMF, Bt) was 11 nT and the North-South
IMF component (Bz) range was -7 to +7 nT. A southern hemisphere
coronal hole is nearing a geoeffective position, with the western
most component nearing 30 degrees West. The solar wind speed
is expected to increase over the 28-29 Oct due to high speed
wind effects from this coronal hole, before declining on 30-Oct
as the influence of this coronal hole wanes.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 27 Oct: G0
Estimated Indices 27 Oct : A K
Australian Region 4 11101222
Cocos Island 3 11101221
Darwin 5 21011223
Townsville 6 21112223
Learmonth 5 11111232
Alice Springs 3 10001222
Gingin 4 11011222
Canberra 3 10001222
Kennaook Cape Grim 4 11101222
Hobart 4 11101222
Estimated Antarctic Regional K Indices 27 Oct :
Macquarie Island 1 01100011
Casey 12 34420123
Mawson 6 22211222
Observed Regional daily pc3 Indices 27 Oct :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 2 (Quiet)
Hobart 8 (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 27 Oct : A
Fredericksburg 10
Planetary 12
Observed AFr/Ap Indices 26 Oct : A K
Fredericksburg 4
Planetary 4 1111 0111
2B. MAGNETIC FORECAST
Date Ap Conditions
28 Oct 32 G1
29 Oct 29 G1
30 Oct 11 G0
COMMENT: ASWFC Geomagnetic Warning 82 was issued on 27 October
and is current for 28-29 Oct. G0 geomagnetic conditions were
observed in the Australian region on UT day 27-Oct. G0 conditions
were observed in the Antarctic region. G1 geomagnetic conditions
are expected over 28-29 Oct, with G0 conditions expected on 30-Oct.
This is due to anticipated coronal hole high speed wind stream
effects.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
27 Oct Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
28 Oct Fair Fair Fair-poor
29 Oct Fair Fair Fair-poor
30 Oct Normal-fair Normal-fair Normal-fair
COMMENT: HF radio propagation conditions on UT day 27-Oct were
normal. Mild HF depressions are expected over 28-30 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
27 Oct 118
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Enhanced by 35% during local night.
Niue Island Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Southern Australian Region:
Near predicted monthly values during local day.
Enhanced 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
28 Oct 90 Near predicted monthly values
29 Oct 60 Depressed 15%/near predicted monthly values
30 Oct 75 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 27-Oct were near predicted monthly values in
the Australian region throughout local day, with enhancements
of 15% in the Southern Australian region at local night. Enhancements
of 20% were seen in the Northern Australian region during local
night. MUFs are expected to be near monthly predicted values
on 28-Oct & 30-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 26 Oct
Daily Proton Fluence >1 MeV: 1.8E+05
Daily Proton Fluence >10 MeV: 1.8E+04
Daily Electron Fluence >2 MeV: 1.90E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B4.7
DSCOVR Satellite Solar Wind Day Averaged Data for 26 Oct
Speed: 392 km/sec Density: 3.4 p/cc Temp: 84000 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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