[Ips-dsgr] ASWFC Daily Report - 04 August 26 issued 2330 UT on 04 Aug 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Wed Aug 5 09:30:49 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/04 AUGUST 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 04 AUGUST AND FORECAST FOR 05 AUGUST - 07 AUGUST
STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 04 Aug: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 04 Aug: 118/70
1B. SOLAR FORECAST
05 Aug 06 Aug 07 Aug
Activity R0, chance of R1 R0, chance of R1 R0, chance of R1
Fadeouts None expected None expected None expected
10.7cm/SSN 115/66 110/60 110/60
COMMENT: Solar flare activity on UT day 04-Aug was at the R0
level, with no significant flares observed. There are currently
six sunspot regions on the visible solar disk, with Active Region
(AR) 4498 (N14W28, beta) being the largest. This region has remained
stable over the past UT day. AR 4502 (S11W23, beta) has shown
mild growth over the same period. A new region, AR 4503 (S17E68),
has recently rotated over the eastern limb, with a magnetic classification
currently dominated by limb foreshortening. All other regions
are either stable or in decay. Solar flare activity is forecast
to remain at the R0 level over 05-07 Aug, with a chance of R1
due to the presence of region 4498. Solar radiation storm conditions
were at the S0 level throughout 04-Aug, and are forecast to remain
at the S0 level over 05-07 Aug. A coronal mass ejection (CME)
was observed in Stereo-A from 04/1323UT, associated with dimming
observed on the solar disk in SDO/AIA 211A from 04/1230UT. Initial
modelling of this event has suggested a glancing impact is possible
at Earth at 08/0800UT +/- 12 hours. However, further imaging
is required to better constrain the CME trajectory. Additional
analysis of the three CMEs first observed on 03-Aug has confirmed
that a combined minor glancing impact is forecast to arrive at
Earth at 04/0700UT +/- 10 hours. The solar wind speed was at
a constant light to moderate level over 04-Aug, broadly ranging
between 360-440 km/s throughout the UT day. The interplanetary
magnetic field strength (IMF, Bt) decreased during 04-Aug, peaking
at 11 nT early in the UT day, before declining after 04/0919UT.
The north-south component (Bz) of the IMF ranged between -10
and +9 nT over the UT day, with extended periods of significant
southward Bz between 03/2358UT and 04/0217UT, as well as between
04/0432UT and 04/0807UT. The solar wind is expected to remain
near background values over 05-06 Aug, before rising on 07-Aug
due to the glancing impacts of the CMEs first observed on 03-Aug.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 04 Aug: G0
Estimated Indices 04 Aug : A K
Australian Region 3 22220001
Cocos Island 2 22110000
Darwin 3 22220001
Townsville 4 32220001
Learmonth 6 33220011
Alice Springs 4 32220001
Gingin 5 32220011
Canberra 3 22220000
Kennaook Cape Grim 4 22230000
Hobart 4 22231000
Estimated Antarctic Regional K Indices 04 Aug :
Macquarie Island 9 33341000
Casey 6 33220011
Mawson 19 54432141
Observed Regional daily pc3 Indices 04 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 04 Aug : A
Fredericksburg 14
Planetary 16
Observed AFr/Ap Indices 03 Aug : A K
Fredericksburg 17
Planetary 19 4433 3234
2B. MAGNETIC FORECAST
Date Ap Conditions
05 Aug 6 G0
06 Aug 6 G0
07 Aug 15 G0, slight chance of G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on 04-Aug, with G0 conditions also recorded at the planetary
level. Mostly G0 geomagnetic conditions were reported in the
Antarctic region, with an isolated G1 interval observed at Mawson.
G0 geomagnetic conditions are forecast over 05-06 Aug. G0, with
a slight chance of G1 conditions are forecast on 07-Aug due to
the glancing impacts of several CMEs observed over 03-Aug.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
04 Aug Normal Normal-fair Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
05 Aug Normal Normal Normal-fair
06 Aug Normal Normal Normal
07 Aug Normal Normal Normal-fair
COMMENT: Global high-frequency (HF) radio propagation conditions
on UT day 04-Aug were mostly normal, with fair conditions reported
in high latitude northern hemisphere locations. Degradations
were also observed in European mid-latitude regions during the
first half of the UT day, and in North American regions during
the second half of the UT day. Global HF propagation conditions
are forecast to be mostly normal over the period 05-07 Aug.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
04 Aug 72
Observed Australian Regional MUFs
Cocos Island Region:
No data available during local day.
No data available during local night.
Niue Island Region:
Near predicted monthly values during local day.
Depressed by 20% during local night.
Depressed by 20% after local dawn.
Northern Australian Region:
Mostly near predicted monthly values.
Southern Australian Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed 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
05 Aug 70 Near predicted monthly values
06 Aug 70 Near predicted monthly values
07 Aug 70 Near predicted monthly values
COMMENT: Maximum Usable Frequencies (MUFs) on UT day 04-Aug in
the Australian region were mostly near predicted values, with
some enhancements observed in the southern Australian region
during local night hours. Depressions of up to 20% were observed
at Niue Island. Strong spread-F and sporadic E were observed
during local night hours at Hobart and Canberra, with spread-F
also observed at Learmonth. MUFs are forecast to remain near
predicted values over 05-07 Aug.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 03 Aug
Daily Proton Fluence >1 MeV: 1.5E+07
Daily Proton Fluence >10 MeV: 2.0E+04
Daily Electron Fluence >2 MeV: 1.20E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B5.9
DSCOVR Satellite Solar Wind Day Averaged Data for 03 Aug
Speed: 378 km/sec Density: 9.9 p/cc Temp: 198000 K Bz: -6 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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