[Ips-dsgr] ASWFC Daily Report - 23 July 26 issued 2330 UT on 23 Jul 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Fri Jul 24 09:30:50 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/23 JULY 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 23 JULY AND FORECAST FOR 24 JULY - 26 JULY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 23 Jul: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 23 Jul: 148/102
1B. SOLAR FORECAST
24 Jul 25 Jul 26 Jul
Activity R1, chance R2 R1, chance R2 R1, chance R2
Fadeouts Possible Possible Possible
10.7cm/SSN 148/102 146/100 152/107
COMMENT: Solar flare activity on UT day 23-Jul was at the R0
level with the largest a C5.4 flare at 22/1851UT, produced by Active
Region (AR) 4493 (N05W31, beta-gamma-delta). There are currently five
numbered and one unnumbered sunspot regions visible on the solar
disk. AR4493 is the largest and most magnetically complex region
and has exhibited slight growth in its intermediate spots. AR4494
(S04E36, beta-delta) and recently numbered AR4495 (S06E30, alpha)
also exhibited growth over the UT day. All other regions are
either stable or in decay. Solar flare activity is forecast to
be at the R1 level over 24-26 Jul, with a chance of R2, due to
the magnetic complexity of AR4493 and AR4494. S0 solar radiation
storm conditions were observed over UT day 23-Jul. S0 solar radiation
storm conditions are forecast over 24-26 Jul. No Earth-directed
coronal mass ejections (CMEs) have been observed in coronagraph
imagery over the past UT day. A faint north-directed CME was
observed in SOHO/C2 imagery from 22/1836UT. This CME is considered
a farside event and therefore not geoeffective. The solar wind
speed on UT day 23-Jul increased, ranging from 460 to 710 km/s
and is currently near 600 km/s. The interplanetary magnetic field
strength (IMF, Bt) peaked at 11 nT, with the north-south component
(Bz) ranging between -8 and +9 nT over the UT day. A sustained
period of southward IMF conditions was observed over the interval
22/1700-2052UT. The solar wind speed is expected to remain elevated
over 24-26 Jul due to ongoing coronal hole high speed wind stream
effects from an northern hemisphere coronal hole.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 23 Jul: G0
Estimated Indices 23 Jul : A K
Australian Region 12 22232433
Cocos Island 9 11222333
Darwin 11 22222433
Townsville 12 22232433
Learmonth 16 22232534
Alice Springs 12 21232433
Gingin 14 22232434
Canberra 12 21232433
Kennaook Cape Grim 15 22243433
Hobart 14 11243433
Estimated Antarctic Regional K Indices 23 Jul :
Macquarie Island 25 10444643
Casey 25 44333454
Mawson 38 44544465
Observed Regional daily pc3 Indices 23 Jul :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 45 (Unsettled)
Canberra 26 (Quiet to unsettled)
Hobart 58 (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 23 Jul : A
Fredericksburg 17
Planetary 27
Observed AFr/Ap Indices 22 Jul : A K
Fredericksburg 11
Planetary 12 2323 3323
2B. MAGNETIC FORECAST
Date Ap Conditions
24 Jul 20 G0-G1
25 Jul 10 G0
26 Jul 5 G0
COMMENT: Geomagnetic conditions in the Australian region were
at the G0 level on UT day 23-Jul, with G1 conditions also reported
at the planetary level. G1-G2 conditions were reported in the
Antarctic region. G0-G1 geomagnetic conditions are forecast over
24 Jul due to ongoing coronal hole high speed wind stream effects.
G0 geomagnetic conditions are forecast for 25-26 Jul.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
23 Jul Normal Normal-fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
24 Jul Normal Normal-fair Fair
25 Jul Normal Normal Fair-normal
26 Jul Normal Normal Normal
COMMENT: Global high-frequency (HF) radio propagation conditions
were mostly normal on UT day 23-Jul, with some degradations in
high latitude regions. Global HF propagation conditions are forecast
to be mostly normal over 24-26 Jul with fair to normal conditions
at high latitudes due to forecast geomagnetic activity. Shortwave
fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
23 Jul 77
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.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
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
24 Jul 70 Depressed 15%/near predicted monthly values
25 Jul 80 Near predicted monthly values
26 Jul 80 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 67 was issued on
22 July and is current for 23-24 Jul. Maximum Usable Frequencies
(MUFs) in the Australian region were near predicted values on
23-Jul. Spread-F was observed at Canberra, Horbart, Perth, Learmonth
and Norfolk Island during local night hours. MUFs are forecast
to be near predicted monthly values to 15% depressed over 24
Jul due to expected geomagnetic activity, before recovering to
near predicted values on 25-Jul and 26-Jul. Shortwave fadeouts
are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 22 Jul
Daily Proton Fluence >1 MeV: 8.0E+04
Daily Proton Fluence >10 MeV: 1.9E+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: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 22 Jul
Speed: 426 km/sec Density: 8.7 p/cc Temp: 258000 K Bz: 0 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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