[Ips-dsgr] ASWFC Daily Report - 26 July 26 issued 2330 UT on 26 Jul 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Mon Jul 27 09:30:51 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/26 JULY 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 26 JULY AND FORECAST FOR 27 JULY - 29 JULY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 26 Jul: R1
Flares Max Fadeout Freq. Sectors
M3.2 1528UT possible lower South American/
Atlantic
Observed 10.7 cm flux/Equivalent Sunspot Number for 26 Jul: 148/102
1B. SOLAR FORECAST
27 Jul 28 Jul 29 Jul
Activity R0-R1 R0, chance of R1 R0, chance of R1
Fadeouts Possible None expected None expected
10.7cm/SSN 150/105 150/105 145/99
COMMENT: Solar flare activity reached the R1 level on UT day
26-Jul with an M3.2 flare peaking at 26/1528UT from Active Region
(AR) 4494 (S04E05, beta). This is one of six sunspot regions
on the solar disk, and has shown some decay following this flare.
Nearby AR 4495 (S02W09, beta) has shown growth over the past
UT day. Region 4496 has also shown some mild growth in trailing
spots over the same period. All other regions are stable or in
decay. Solar flare activity is forecast to be at the R0-R1 level
on 27-Jul, due to the past flare activity of several regions
on the disk. This is forecast to decline to R0, with a chance
of R1 over 28-29 Jul, as a previously flare-active region rotates
off the disk and other active regions continue to simplify. S0
solar radiation storm conditions were observed throughout 26-Jul,
with S0 conditions forecast over 27-29 Jul. A low-velocity coronal
mass ejection (CME) was observed in STEREO-A/COR2, coincident
with the aforementioned M3.2 flare. Preliminary modelling suggests
this CME will likely pass behind the Earth. However, additional
imaging is required in order to confirm if this event contains
a geoeffective component. A second CME was observed in SOHO/LASCO
from 26/2036UT. While this appears to be a farside event, additional
imaging is required to rule out any Earth-directed component.
The solar wind speed continued to decline over UT day 26-Jul,
as the effects of the previous coronal hole high speed wind stream
continued to abate. The solar wind speed began the day at 500
km/s, and is currently at 440-460 km/s. The interplanetary magnetic
field strength (IMF, Bt) peaked at 5 nT early in the UT day,
with the north-south component (Bz) ranging between -4 and +4
nT over the UT day. The solar wind is forecast to increase on
27-Jul, due to the glancing impact of a CME first observed on
24-Jul. The solar wind speed is then expected to decline over
28-29 Jul, as the effects of this CME pass.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 26 Jul: G0
Estimated Indices 26 Jul : A K
Australian Region 2 12120000
Cocos Island 2 12110000
Darwin 2 12120001
Townsville 3 12120012
Learmonth 2 12110000
Alice Springs 2 12110000
Gingin 2 12110000
Canberra 2 12120001
Kennaook Cape Grim 2 12121000
Hobart 2 12121000
Estimated Antarctic Regional K Indices 26 Jul :
Macquarie Island 1 01020000
Casey 6 34210100
Mawson 7 23321003
Observed Regional daily pc3 Indices 26 Jul :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 6 (Quiet)
Canberra 8 (Quiet)
Hobart 4 (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 26 Jul : A
Fredericksburg 6
Planetary 5
Observed AFr/Ap Indices 25 Jul : A K
Fredericksburg 6
Planetary 5 1112 1222
2B. MAGNETIC FORECAST
Date Ap Conditions
27 Jul 21 G1
28 Jul 12 G0
29 Jul 8 G0
COMMENT: ASWFC Geomagnetic Warning 47 was issued on 26 July and
is current for 27 Jul only. Geomagnetic conditions in the Australian
region were at the G0 level throughout 26-Jul, with G0 conditions
also reported in the Antarctic region, as well as at the planetary
level. G1 geomagnetic conditions are forecast on 27-Jul due to
the glancing impact of a CME first observed on 24-Jul. G0 conditions
are forecast for 28-29 Jul as this event passes.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
26 Jul Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
27 Jul Fair Fair Fair
28 Jul Normal-fair Normal-fair Normal-fair
29 Jul Normal Normal Normal
COMMENT: Global high-frequency (HF) radio propagation conditions
were normal on UT day 26-Jul, with no significant degradations
observed. Global HF propagation conditions are forecast to decline
to fair conditions on 27-Jul, due to anticipated geomagnetic
activity. Conditions will then trend toward normal over 28-29
Jul as this geomagnetic activity subsides. Isolated shortwave
fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
26 Jul 85
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.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
Southern Australian Region:
Mostly near predicted monthly values.
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
27 Jul 70 Depressed 10 to 15%/near predicted monthly values
28 Jul 80 Near predicted monthly values
29 Jul 84 Near predicted monthly values
COMMENT: Maximum Usable Frequencies (MUFs) in the Australian
region were mostly near predicted values on 26-Jul, with some
enhancements observed in the northern Australian region. Some
spread-F was observed at Canberra, Perth, and Hobart during local
night hours, with strong sporadic-E observed at Darwin, Perth,
and Townsville. MUFs are expected to become depressed over 27-Jul
due to anticipated geomagnetic activity, with depressions of
up to 15% forecast. MUFs will then recover toward predicted values
on 28-29 Jul. Isolated shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 25 Jul
Daily Proton Fluence >1 MeV: 1.9E+05
Daily Proton Fluence >10 MeV: 1.9E+04
Daily Electron Fluence >2 MeV: 6.00E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 8%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B8.3
DSCOVR Satellite Solar Wind Day Averaged Data for 25 Jul
Speed: 510 km/sec Density: 3.3 p/cc Temp: 144000 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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