[Ips-dsgr] ASWFC Daily Report - 31 July 26 issued 2334 UT on 31 Jul 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sat Aug 1 09:34:12 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/31 JULY 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 31 JULY AND FORECAST FOR 01 AUGUST - 03 AUGUST
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 31 Jul: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 31 Jul: 148/102
1B. SOLAR FORECAST
01 Aug 02 Aug 03 Aug
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 145/99 140/94 140/94
COMMENT: Solar flare activity on UT day 31-Jul was at the R0
level, with several low level C-class flares observed. There
are currently six numbered regions visible on the solar disk.
Active Region (AR) 4499 (N04W05, beta-gamma) is the most magnetically
complex region on the disk and has shown some decay over the
UT day. Regions 4496 (N05W33, beta) and 4500 (N18E32, beta) have
exhibited mild growth in their trailer spots over the 24-hour
period. Regions 4501 (S09W07, beta) and 4498 (N15E25, beta) have
both shown spot growth. All other regions are either stable or
in decay. Solar flare activity is expected to be at R0-R1 levels
over 01-03 Aug due to the number of regions on the disk and the
magnetic complexity of region 4499. S1 solar radiation storm
conditions were observed on UT day 31-Jul, with a peak of 17.6
pfu observed at 31/1555UT. S0-S1 solar radiation storm conditions
are forecast for 01-Aug, declining to S0, chance of S1 over 02-03
Aug, due to the ongoing elevated proton flux conditions. No Earth-directed
coronal mass ejections (CMEs) have been observed on UT day 31-Jul.
Additional modelling has been completed of the high velocity
CME first observed on 30-Jul, with an updated arrival time of
01/2200UT +/- 10 hours. The solar wind speed on UT day 31-Jul
was mostly stable, ranging from 315 to 330 km/s and is currently
near 330 km/s. The peak total interplanetary magnetic field strength
(IMF, Bt) was 7 nT and the north-south IMF component (Bz) range
was -4 to +5 nT. The solar wind speed is expected to increase
late on 01-Aug due to the arrival of a CME first observed on
30-Jul, then remain elevated over 02-03 Aug.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 31 Jul: G0
Estimated Indices 31 Jul : A K
Australian Region 2 01102100
Cocos Island 0 01010000
Darwin 2 11102101
Townsville 3 11112102
Learmonth 2 01202100
Alice Springs 2 01102101
Gingin 2 10102100
Canberra 1 00002100
Kennaook Cape Grim 2 01102200
Hobart 2 01002200
Estimated Antarctic Regional K Indices 31 Jul :
Macquarie Island 0 00001100
Casey 5 22212211
Mawson 8 32111214
Observed Regional daily pc3 Indices 31 Jul :
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 31 Jul : A
Fredericksburg 7
Planetary 9
Observed AFr/Ap Indices 30 Jul : A K
Fredericksburg 8
Planetary 5 1112 2211
2B. MAGNETIC FORECAST
Date Ap Conditions
01 Aug 14 G2, chance of G3
02 Aug 28 G2, chance of G3
03 Aug 12 G0, chance of G1
COMMENT: ASWFC Geomagnetic Warning 48 was issued on 31 July and
is current for 1-2 Aug. G0 geomagnetic conditions were observed
in the Australian, planetary and Antarctic regions on UT day
31-Jul. G2 planetary geomagnetic conditions are expected over
01-02 Aug, with a chance of G3 due to the arrival of a CME first
observed on 30-Jul. G0 geomagnetic conditions are expected on
03-Aug, with a chance of G1 as CME effects abate.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
31 Jul Normal Normal-fair Normal-fair
PCA Event : 10MeV Proton/PCA Event Began at 1835UT 30/07, Ended at 0115UT 31/07
and, 10MeV Proton/PCA Event Began at 0310UT 31/07, Ended at 0425UT 31/07
and, 10MeV Proton/PCA Event Began at 1350UT 31/07, Ended at 1735UT 31/07
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
01 Aug Normal Normal Normal-fair
02 Aug Fair Fair Fair-poor
03 Aug Normal Normal Normal-fair
COMMENT: Global high-frequency (HF) radio propagation conditions
were mostly normal on UT day 31-Jul, with some degradations observed
in southern hemisphere regions in the second half of the UT day.
Global HF propagation conditions are forecast to remain mostly
normal on 01-Aug. Conditions are expected to be fair on 02-Aug,
due to the effects of a glancing CME currently forecast to impact
Earth on this day. Conditions are expected to return to mostly
normal on 03-Aug. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
31 Jul 81
Observed Australian Regional MUFs
Cocos Island Region:
No data available during local day.
No data available during local night.
Niue Island Region:
Enhanced by 30% during local day.
Near predicted monthly values 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):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Jun 81
Jul 66
Aug 63
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
01 Aug 80 Near to 15% above predicted monthly values
02 Aug 55 Near predicted monthly values
03 Aug 55 Near predicted monthly values
COMMENT: Maximum Usable Frequencies (MUFs) in the Australian
region on 31-Jul were near predicted monthly values, with enhancements
of 20% observed in the southern Australian region. Sporadic E
was observed at Canberra. Spread-F was observed at several Australian
sites during local night hours. MUFs are forecast to be near
predicted monthly values to 15% enhanced on 01-Aug. MUFs are
expected to decline to near predicted monthly values over 02-03
Aug, with depressions of 10-15% possible on these days due to
forecast geomagnetic activity. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 30 Jul
Daily Proton Fluence >1 MeV: 6.6E+05
Daily Proton Fluence >10 MeV: 3.2E+05
Daily Electron Fluence >2 MeV: 3.63E+07 (normal fluence)
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 30 Jul
Speed: 334 km/sec Density: 2.8 p/cc Temp: 60500 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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