[Ips-dsgr] ASWFC Daily Report - 25 August 26 issued 2330 UT on 25 Aug 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Wed Aug 26 09:30:50 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/25 AUGUST 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 25 AUGUST AND FORECAST FOR 26 AUGUST - 28 AUGUST
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 25 Aug: R2
Flares Max Fadeout Freq. Sectors
M1.9 0126UT possible lower West Pacific
M1.0 0403UT possible lower E. Asia/Aust.
M1.8 0640UT possible lower Mid East/Indian
M6.9 1002UT probable lower European
Observed 10.7 cm flux/Equivalent Sunspot Number for 25 Aug: 132/86
1B. SOLAR FORECAST
26 Aug 27 Aug 28 Aug
Activity R1, chance of R2 R1, chance of R2 R1, chance of R2
Fadeouts Possible Possible Possible
10.7cm/SSN 135/89 133/87 130/84
COMMENT: Solar flare activity on UT day 25-Aug was at the R2
level due to an M6.9 flare at 25/1002UT produced by Active Region
(AR) 4513 (N04E05, beta-gamma-delta). This region also produced
three additional flares at the R1 level over the UT day. There
are currently four numbered sunspot regions visible on the solar
disk. Region 4513 is the most magnetically complex region on
the disk and has shown some decay in its intermediate spots over
the past 24 hours. AR 4517 (N09W12, beta) has exhibited spot
development in its intermediate spots. AR 4516 (N04E05, beta)
has shown growth in its leader spots, whilst its trailer spot
has decayed. AR 4515 (S08E13, alpha) is simple and stable. Solar
flare activity is expected to be at the R1 level over 26-28 Aug,
with a chance of R2 due to the observed flare activity and magnetic
complexity of AR 4513. S0 solar radiation storm conditions were
observed on UT day 25-Aug, with the proton flux gradually declining
over the UT day. S0 solar radiation storm conditions are expected
over 26-28 Aug, with a chance of S1 due to the current mildly
elevated proton flux conditions. An east-directed coronal mass
ejection (CME) was observed, visible in STEREO-A coronagraph
imagery from 25/1038UT. This CME is considered to be associated
with the aforementioned M6.9 flare from AR 4513. A filament eruption
was observed, visible in H-alpha imagery from 1236UT near S01E20.
A subsequent associated narrow CME was observed in STEREO-A at
25/1253UT. Modelling of the above CMEs indicates the bulk of
the ejecta will miss Earth. However, the flank of the disturbance
is expected to produce a glancing arrival at Earth, with an estimated
arrival time of 0200UT +/- 10 hours on UT day 28-Aug. No other
Earth-directed CMEs have been observed. The solar wind speed
on UT day 25-Aug declined, ranging between 355 and 320 km/s,
and is currently near 325 km/s. The peak total interplanetary
magnetic field strength (IMF, Bt) was 7 nT and the north-south
IMF component (Bz) range was -1 to +4 nT. The solar wind speed
is expected to remain at background levels on 26-Aug, then increase
on 27-Aug due to coronal hole high speed wind stream effects
from a southern hemisphere coronal hole. A further increase is
expected on 28-Aug due to the arrival of two CMEs first observed
on 25-Aug.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 25 Aug: G0
Estimated Indices 25 Aug : A K
Australian Region 2 11210100
Cocos Island 2 11120000
Darwin 3 12210101
Townsville 3 22210101
Learmonth 2 11210200
Alice Springs 2 11210100
Gingin 2 11200100
Canberra 1 11100000
Kennaook Cape Grim 1 11100100
Hobart 1 11100100
Estimated Antarctic Regional K Indices 25 Aug :
Casey 4 22310110
Mawson 3 31100020
Observed Regional daily pc3 Indices 25 Aug :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 0 (Quiet)
Hobart 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 25 Aug : A
Fredericksburg 4
Planetary 4
Observed AFr/Ap Indices 24 Aug : A K
Fredericksburg 8
Planetary 6 2211 1013
2B. MAGNETIC FORECAST
Date Ap Conditions
26 Aug 4 G0
27 Aug 10 G0
28 Aug 22 G1, chance of G2
COMMENT: G0 geomagnetic conditions were observed in the planetary,
Australian and Antarctic regions on UT day 25-Aug. G0 planetary
geomagnetic conditions are expected over 26-27 Aug. G1 planetary
geomagnetic conditions are expected on 28-Aug, with a chance
of G2 due to the arrival of two CMEs first observed on 25-Aug.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
25 Aug Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
26 Aug Normal Normal Normal
27 Aug Normal Normal Normal-fair
28 Aug Normal Normal-fair Fair
COMMENT: HF radio propagation conditions on UT day 25-Aug were
normal. HF radio propagation conditions are expected to be mostly
normal over 26-27 Aug. Normal to fair conditions are expected
on 28-Aug due to anticipated geomagnetic activity. Shortwave
fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
25 Aug 79
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.
Enhanced by 85% during local night.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
Enhanced by 20% after local dawn.
Antarctic Region (Casey/Davis/Mawson):
Enhanced by 20% over the UT day.
Monthly T index:
Month T index
Jul 75
Aug 64
Sep 61
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
26 Aug 75 Near predicted monthly values
27 Aug 75 Near predicted monthly values
28 Aug 55 Near predicted monthly values/depressed 10 to
15%
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 25-Aug were near predicted monthly values, with
enhancements observed in the southern Australian region. MUFs
are expected to be near predicted monthly values over 26-27 Aug.
MUFs are expected to be near predicted monthly values to 10-15%
depressed on 28-Aug due to anticipated geomagnetic activity.
Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 24 Aug
Daily Proton Fluence >1 MeV: 2.8E+06
Daily Proton Fluence >10 MeV: 2.7E+05
Daily Electron Fluence >2 MeV: 7.70E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 9%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B6.9
Solar Wind Day Averaged Data for 24 Aug
Speed: 363 km/sec Density: 2.4 p/cc Temp: 60400 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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