[Ips-dsgr] ASWFC Daily Report - 19 July 25 issued 2331 UT on 19 Jul 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sun Jul 20 09:31:58 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/19 JULY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 19 JULY AND FORECAST FOR 20 JULY - 22 JULY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 19 Jul: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 19 Jul: 153/108
1B. SOLAR FORECAST
20 Jul 21 Jul 22 Jul
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 150/105 148/102 145/99
COMMENT: Solar activity on UT day 19-Jul was R0, with no significant
solar flares. The solar regions currently on the solar disk are
small to medium in size. Minor solar region AR4135 (S08W78, alpha)
produced a C3.3 flare at 19/0907UT. There is a group of solar
regions in the northwest solar quadrant with the larger of these
regions being AR4136 (N19W63, beta-gamma), AR4139 (N22W82, beta)
and AR4143(N23W47, beta). These regions appear to be stable or
in slow decay. Another of the larger on disk solar regions is
located just west of the centre of the solar disk, AR4142 (N01W15,
beta) and is also in slow decline, with some redistribution in
its leader spots. Two new regions AR4149 (N17E77, beta) and AR4150
(S15E72, beta) have recently rotated on to the solar disk and
are currently stable bipolar groups, with AR4149 appearing the
larger and more active. There are currently nine numbered sunspot
regions on the solar disk. All other sunspot regions are relatively
small and either stable or in decay. Solar activity is expected
to be R0-R1 over 20-22 Jul. No Earth directed CMEs were observed
on UT day 19-Jul. S0 solar radiation storm conditions were observed
on UT day 19-Jul. S0 solar radiation storm conditions are expected
over 20-22 Jul. The solar wind speed on UT day 19-Jul declined
as the influence of a solar wind stream from a coronal hole now
located in the far southwest solar quadrant gradually abates.
The solar wind speed ranged from 440 to 550 km/s and is currently
at 440 km/s. The magnitude of the interplanetary magnetic field
is small. The peak total interplanetary field strength (IMF,
Bt) was 6 nT and the north-south IMF component range (Bz) was
+6 to -4 nT. The solar wind speed is expected to continue to
decline today. An isolated equatorial coronal hole is now near
the solar central meridian. The Earth is expected to enter the
wind steam from this hole from late in the UT day on 22-Jul.
This equatorial coronal hole appears smaller on this solar rotation.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 19 Jul: G0
Estimated Indices 19 Jul : A K
Australian Region 5 12221211
Cocos Island 1 11110010
Darwin 6 13221211
Townsville 6 22221212
Learmonth 5 12221220
Alice Springs 4 12221111
Gingin 5 12221221
Canberra 3 12121200
Kennaook Cape Grim 4 12121210
Hobart 4 12121210
Estimated Antarctic Regional K Indices 19 Jul :
Macquarie Island 2 01121200
Casey 10 34322111
Mawson 14 24423223
Observed Regional daily pc3 Indices 19 Jul :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 2 (Quiet)
Canberra 2 (Quiet)
Hobart 2 (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 19 Jul : A
Fredericksburg 5
Planetary 5
Observed AFr/Ap Indices 18 Jul : A K
Fredericksburg 9
Planetary 11 2123 4322
2B. MAGNETIC FORECAST
Date Ap Conditions
20 Jul 9 G0
21 Jul 8 G0
22 Jul 16 G0, isolated G1 periods possible late in the
UT day
COMMENT: ASWFC Geomagnetic Warning 56 was issued on 19 July and
is current for 22-24 Jul. G0 geomagnetic conditions were observed
in the Australian and Antarctic regions on UT day 19-Jul. G0
geomagnetic conditions are expected over 20-21 Jul, with isolated
planetary G1 periods possible from late in the UT day on 22-Jul
to 24-Jul due to a wind stream from an equatorial coronal hole.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
19 Jul Normal Normal Fair-normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
20 Jul Normal Fair-normal Fair-normal
21 Jul Normal Normal Normal-fair
22 Jul Normal Normal-fair Fair
COMMENT: HF radio propagation conditions on UT day 19-Jul were
generally normal, with fair conditions at high latitudes. HF
conditions are expected to be mostly normal over 20-21 Jul, with
degraded conditions expected from late on 22-Jul at middle to
high latitudes due mild geomagnetic activity induced by a coronal
hole wind stream.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
19 Jul 95
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 30% during local day.
Depressed by 20% during local night.
Depressed by 30% after local dawn.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values during local day.
Depressed by 20% during local night.
Depressed 20% after local dawn.
Southern Australian Region:
Near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 20% over the UT day.
Monthly T index:
Month T index
Jun 79
Jul 104
Aug 102
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
20 Jul 85 Depressed 10 to 15%/near predicted monthly values
21 Jul 90 Near predicted monthly values
22 Jul 90 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region were 20% depressed to near predicted values, with depressions
observed during local night hours and after dawn in the northern
Australian region. Spread F was observed during local night hours
at Learmonth, Canberra and Hobart, indicating mildly degraded
HF conditions. MUFs are expected to be generally near predicted values
20-22 Jul. Degraded conditions may experienced during local night
hours 22-23 Jul due to mild geomagnetic activity from a coronal
hole wind stream.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 18 Jul
Daily Proton Fluence >1 MeV: 8.4E+05
Daily Proton Fluence >10 MeV: 2.0E+04
Daily Electron Fluence >2 MeV: 4.10E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:21%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 18 Jul
Speed: 550 km/sec Density: 0.4 p/cc Temp: 137000 K Bz: 2 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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