[Ips-dsgr] ASWFC Daily Report - 23 August 26 issued 2330 UT on 23 Aug 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Mon Aug 24 09:30:51 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/23 AUGUST 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 23 AUGUST AND FORECAST FOR 24 AUGUST - 26 AUGUST
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 23 Aug: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 23 Aug: 128/81
1B. SOLAR FORECAST
24 Aug 25 Aug 26 Aug
Activity R0 R0 R0
Fadeouts Possible Possible Possible
10.7cm/SSN 125/78 120/72 120/72
COMMENT: Solar flare activity on UT day 23-Aug was at the R0
level, with a C4.2 flare at 0652UT the largest flare of the UT
day. There are currently four numbered active regions (ARs) visible
on the solar disk. AR 4513 (N04E28, beta-gamma-delta) is the
largest and most magenetically complex region on the solar disk
and has a history of M-class flare production. This region was
responsible for the largest flare of the UT day and showed some
east-west expansion over the day. AR 4517 (N09E13, beta) developed
over the UT day, but is still magnetically simple. The other
two regions are stable and simple. Solar flare activity is expected
to be at R0-R1 levels over 24-26 Aug due to the magnetic complexity
of 4513 and its recent flare activity. Solar radiation storm
conditions were at the S0 level on 23-Aug, with the >10 MeV proton
flux raised but below threshold. S0 conditions are expected over
24-26 Aug, with a chance of S1 over 24-25 Aug due to the currently
enhanced >10 MeV proton flux. The enhanced proton conditions
are due to a long duration flare observed on 21-Aug. No Earth-directed
coronal mass ejections (CMEs) have been observed. The solar wind
speed on UT day 23-Aug decreased as coronal hole high speed wind
stream effects waned, ranging between 380 and 450 km/s, and is
currently near 385 km/s. The peak total interplanetary magnetic
field strength (IMF, Bt) was 6 nT and the north-south IMF component
(Bz) range was -4 to +4 nT. The solar wind speed is expected
to continue to decline towards background levels and remain there
over 24-26 Aug as coronal hole high speed wind stream effects
wane.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 23 Aug: G0
Estimated Indices 23 Aug : A K
Australian Region 3 12211001
Cocos Island 2 11120000
Darwin 4 22211002
Townsville 4 12121112
Learmonth 3 12221000
Alice Springs 2 02211001
Gingin 2 12211000
Canberra 2 12111000
Kennaook Cape Grim 2 12211000
Hobart 3 12211001
Estimated Antarctic Regional K Indices 23 Aug :
Macquarie Island 2 01210100
Casey 7 33231110
Mawson 9 13222124
Observed Regional daily pc3 Indices 23 Aug :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 8 (Quiet)
Canberra 24 (Quiet to unsettled)
Hobart 18 (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 23 Aug : A
Fredericksburg 6
Planetary 6
Observed AFr/Ap Indices 22 Aug : A K
Fredericksburg 5
Planetary 4 1111 1111
2B. MAGNETIC FORECAST
Date Ap Conditions
24 Aug 4 G0
25 Aug 4 G0
26 Aug 4 G0
COMMENT: G0 geomagnetic conditions were observed at the planetary
level and in the Australian and Antarctic regions on UT day 23-Aug.
G0 planetary geomagnetic conditions are expected over 24-26 Aug.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
23 Aug Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
24 Aug Normal Normal Normal
25 Aug Normal Normal Normal
26 Aug Normal Normal Normal
COMMENT: HF radio propagation conditions on UT day 22-Aug were
mostly normal, with some degradations observed at low latitudes
over the day. HF radio propagation conditions are expected to
be mostly normal over 24-26 Aug. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
23 Aug 73
Observed Australian Regional MUFs
Cocos Island Region:
No data available during local day.
No data available during local night.
Niue Island Region:
No data available during local day.
No data available during local night.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Mostly near predicted monthly values.
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
24 Aug 75 Near predicted monthly values
25 Aug 75 Near predicted monthly values
26 Aug 75 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 76 was issued on
22 August and is current for 23-25 Aug. Maximum usable frequencies
(MUFs) in the Australian region on UT day 23-Aug were near predicted
monthly values, with enhancements observed in the southern Australian
region in the last few hours. Spread F was observed at Perth
during local night hours. MUFs are expected to be mostly near
predicted monthly values over 24-26 Aug. Shortwave fadeouts are
possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 22 Aug
Daily Proton Fluence >1 MeV: 1.6E+06
Daily Proton Fluence >10 MeV: 3.5E+05
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: B7.1
Solar Wind Day Averaged Data for 22 Aug
Speed: 436 km/sec Density: 3.0 p/cc Temp: 102000 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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