[Ips-dsgr] ASWFC Daily Report - 29 September 26 issued 2330 UT on 29 Sep 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Wed Sep 30 09:30:50 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/29 SEPTEMBER 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 29 SEPTEMBER AND FORECAST FOR 30 SEPTEMBER - 02 OCTOBER
STATUS INDICATORS SOL:GREEN MAG:** RED ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 29 Sep: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 29 Sep: 92/37
1B. SOLAR FORECAST
30 Sep 01 Oct 02 Oct
Activity R0 R0 R0
Fadeouts None expected None expected None expected
10.7cm/SSN 95/41 95/41 95/41
COMMENT: Solar flare activity was at the R0 level on UT day 29-Sep,
with no significant solar flares observed. There are currently
two active sunspot regions on the visible disk, with Active Region
(AR) 4535 (N11W45, beta) being the largest. This region has shown
decay over the past 24 hours. A new unnumbered region has appeared
at S09W13, with a beta-gamma magnetic classification. Solar flare
activity is forecast to remain at the R0 level through the period
30-Sep to 02-Oct. S0 solar radiation storm conditions were observed
throughout 29-Sep, with S0 conditions forecast over 30-Sep to
02-Oct. No coronal mass ejections (CMEs) were observed over the
previous UT day in available coronagraph imagery. The solar wind
environment was at ambient levels throughout 29-Sep, with the
solar wind speed declining from 320 km/s early in the UT to currently
be at 280 km/s. The interplanetary magnetic field strength (IMF,
Bt) was stable throughout the UT day, peaking at 4 nT, with the
north-south component (Bz) ranging between -2 and +2 nT. The
solar wind is expected to remain at background levels on 30-Sep,
with a rise in the solar wind speed forecast late on 01-Oct due
to the glancing impact of a CME first observed on 28-Sep. The
solar wind speed will continue to rise on 02-Oct due to the ongoing
impact of this CME.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 29 Sep: G0
Estimated Indices 29 Sep : A K
Australian Region 1 11000001
Cocos Island 1 01110000
Darwin 2 11010002
Townsville 1 11010011
Learmonth 1 11000001
Alice Springs 0 01000001
Gingin 0 00000000
Canberra 0 01000001
Kennaook Cape Grim 1 11000001
Hobart 1 11010001
Estimated Antarctic Regional K Indices 29 Sep :
Casey 4 23210010
Mawson 3 21100112
Observed Regional daily pc3 Indices 29 Sep :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 0 (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 29 Sep : A
Fredericksburg 4
Planetary 5
Observed AFr/Ap Indices 28 Sep : A K
Fredericksburg 3
Planetary 4 1211 111-
2B. MAGNETIC FORECAST
Date Ap Conditions
30 Sep 5 G0
01 Oct 10 G0, chance of G1
02 Oct 26 G1, chance of G2
COMMENT: Geomagnetic conditions in the Australian region were
at the G0 level on UT day 29-Sep, with G0 conditions also recorded
in both the Antarctic region and at the planetary level. G0 geomagnetic
conditions are forecast for 30-Sep. G0 conditions, with a chance
of G1, are forecast for 01-Oct due to the arrival of a CME late
in the UT day that was first observed on 28-Sep. G1 geomagnetic
conditions, with a chance of G2, are forecast for 02-Oct due
to the ongoing effects of this CME arrival.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
29 Sep Normal Normal-fair Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
30 Sep Normal Normal Normal
01 Oct Normal Normal Normal-fair
02 Oct Normal-fair Normal-fair Fair
COMMENT: Global high-frequency (HF) radio propagation conditions
on 29-Sep were normal to fair, with some degradations in northern
hemisphere mid-latitude regions during local night hours. Global
HF propagation conditions are forecast to remain mostly normal
over 30-Sep to 01-Oct, with normal to fair conditions forecast
on 02-Oct due to anticipated geomagnetic activity.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
29 Sep 60
Observed Australian Regional MUFs
Cocos Island Region:
No data available during local day.
No data available during local night.
Niue Island Region:
Enhanced by 20% during local day.
Near predicted monthly values during local night.
Northern Australian Region:
Near predicted monthly values.
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
Aug 66
Sep 62
Oct 60
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
30 Sep 65 Near predicted monthly values
01 Oct 65 Near predicted monthly values
02 Oct 50 Depressed 10 to 15%/near predicted monthly values
COMMENT: Maximum Usable Frequencies (MUFs) in the Australian
region were mostly near predicted values on 29-Sep, with some
isolated depressions observed at Darwin and Townsville during
local night hours. Ionospheric scintillation was also recorded
at Darwin between 29/1404-1420UT. Spread-F was observed in Hobart
during local night hours. MUFs are forecast to remain near predicted
values over 30-Sep to 01-Oct, with depressions of 10-15% forecast
on 02-Oct due to anticipated geomagnetic activity.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 28 Sep
Daily Proton Fluence >1 MeV: 4.4E+05
Daily Proton Fluence >10 MeV: 2.2E+04
Daily Electron Fluence >2 MeV: 1.90E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:15%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B2.6
Solar Wind Day Averaged Data for 28 Sep
Speed: 338 km/sec Density: 2.2 p/cc Temp: 44000 K Bz: -1 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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