[Ips-dsgr] ASWFC Daily Report - 24 July 26 issued 2330 UT on 24 Jul 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sat Jul 25 09:30:47 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/24 JULY 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 24 JULY AND FORECAST FOR 25 JULY - 27 JULY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 24 Jul: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 24 Jul: 150/105
1B. SOLAR FORECAST
25 Jul 26 Jul 27 Jul
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 155/109 155/109 155/109
COMMENT: Solar flare activity on UT day 24-Jul was at the R0
level, with no significant flares observed. There are currently
six active sunspot regions on the visible disk, with Active Region
(AR) 4493 (N05W46, beta) being the largest. This region has shown
some minor decay over the past UT day. AR 4496 (N06E60, beta)
has shown growth over the same period, as it continues to rotate
from the eastern limb. AR 4494 (S04E27, beta-delta) maintains
a delta configuration, and has remained stable. All other regions
are either stable or in decay. Solar flare activity is forecast
to be at the R0-R1 level over 25-27 Jul, due to the flare potential
from several active regions currently on the disk. S0 solar radiation
storm conditions were observed on 24-Jul. S0 solar radiation
storm conditions are forecast over 25-27 Jul. A south-directed
medium-velocity coronal mass ejection (CME) was observed in SOHO/LASCO
imaging from 24/0449UT following a filament eruption visible
in GOES/SUVI 304A and GONG Halpha imaging from 24/0419UT. Modelling
suggests a partial impact at Earth is expected on 27-Jul at 27/1100UT
+/- 10 hours. The solar wind speed was elevated over 24-Jul due
to the ongoing effects of a northern coronal hole high speed
wind stream. The solar wind speed began the day at 630-670 km/s,
and slowly declined as the high speed wind stream effect waned,
and is currently at 540-550 km/s. The interplanetary magnetic
field strength (IMF, Bt) peaked at 8 nT early in the UT day,
with the north-south component (Bz) ranging between -7 and +6
nT. The solar wind speed is expected to continue declining over
25-26 Jul as the coronal hole continues to move past a geoeffective
position. The solar wind will then increase on 27-Jul due to
the forecast impact of the CME first observed on 24-Jul.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 24 Jul: G0
Estimated Indices 24 Jul : A K
Australian Region 3 32100000
Cocos Island 3 32110000
Darwin 3 32100000
Townsville 5 33210001
Learmonth 5 43100000
Alice Springs 3 32200000
Gingin 5 42200000
Canberra 3 32100001
Kennaook Cape Grim 5 42110000
Hobart 5 42110001
Estimated Antarctic Regional K Indices 24 Jul :
Macquarie Island 1 21100000
Casey 7 43211100
Mawson 27 74432001
Observed Regional daily pc3 Indices 24 Jul :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 4 (Quiet)
Alice Springs 0 (Quiet)
Gingin 60 (Unsettled)
Canberra 34 (Quiet to unsettled)
Hobart 43 (Unsettled)
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 24 Jul : A
Fredericksburg 12
Planetary 13
Observed AFr/Ap Indices 23 Jul : A K
Fredericksburg 15
Planetary 22 2233 3553
2B. MAGNETIC FORECAST
Date Ap Conditions
25 Jul 7 G0
26 Jul 5 G0
27 Jul 21 G1
COMMENT: ASWFC Geomagnetic Warning 46 was issued on 23 July and
is current for 24-25 Jul. Geomagnetic conditions in the Australian
region were at the G0 level on UT day 24-Jul, with G0 conditions
reported at the planetary scale. Mostly G0 conditions were reported
in the Antarctic region, with an isolated G3 interval recorded
early in the UT day at Mawson. G0 conditions are forecast over
25-26 Jul. G1 conditions are expected on 27-Jul due to the partial
impact of a CME first observed on 24-Jul.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
24 Jul Normal Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
25 Jul Normal Normal Normal
26 Jul Normal Normal Normal
27 Jul Fair Fair Fair
COMMENT: Global high frequency (HF) radio propagation conditions
on UT day 24-Jul were normal to fair, with some degradations
observed in the northern hemisphere mid and high latitude regions,
particularly over the European and North American regions. Global
HF propagation conditions are forecast to be mostly normal over
25-26 Jul, becoming fair on 27-Jul due to anticipated geomagnetic
activity. Isolated shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
24 Jul 83
Observed Australian Regional MUFs
Cocos Island Region:
No data available during local day.
No data available during local night.
Niue Island Region:
Enhanced by 15% during local day.
Depressed by 15% during local night.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 15% 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
25 Jul 75 Near predicted monthly values
26 Jul 75 Near predicted monthly values
27 Jul 60 Depressed 10 to 15%/near predicted monthly values
COMMENT: Maximum Usable Frequencies (MUFs) in the Australian
region were mostly near predicted values over 24-Jul. Strong
mixed spread-F was observed at Canberra, Hobart, Perth, and Learmonth
during local night hours. MUFs are forecast to be near predicted
monthly values over the period 25-26 Jul, with depressions of
15% forecast for 27-Jul due to forecast geomagnetic activity.
Isolated shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 23 Jul
Daily Proton Fluence >1 MeV: 8.7E+05
Daily Proton Fluence >10 MeV: 1.9E+04
Daily Electron Fluence >2 MeV: 1.50E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B8.2
DSCOVR Satellite Solar Wind Day Averaged Data for 23 Jul
Speed: 604 km/sec Density: 7.5 p/cc Temp: 352000 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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