[Ips-dsgr] ASWFC Daily Report - 24 July 25 issued 2332 UT on 24 Jul 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Fri Jul 25 09:32:19 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/24 JULY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 24 JULY AND FORECAST FOR 25 JULY - 27 JULY
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN 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: 156/110
1B. SOLAR FORECAST
25 Jul 26 Jul 27 Jul
Activity R0, chance of R1 R0, chance of R1 R0, chance of R1
Fadeouts Possible Possible Possible
10.7cm/SSN 155/109 150/105 155/109
COMMENT: Solar activity on UT day 24-Jul was at the R0 level
with several C-class flares. There are currently seven numbered
sunspot regions and one unnumbered region visible on the solar
disk. AR4153 (S38E35, beta) showed spot growth over the UT day,
whilst AR4149 (N16E09, beta-gamma) and AR1455 (S07E62, beta)
showed growth in their trailer spots. AR4149 is the largest and
most magnetically complex sunspot region on the solar disk, but
has yet to produce significant flares. An unnumbered region has
emerged on the disk at around S21W45 with beta magnetic complexity.
All other regions and either stable or in decay. Solar activity
is expected to be at the R0 level, with a chance of R1 over 25-27
Jul. S0 solar radiation storm conditions were observed on UT
day 24-Jul. S0 solar radiation storm conditions are expected
over 25-27 Jul. No significantly Earth directed CMEs were observed
on 24-Jul. A west directed, faint CME is visible in SOHO imagery
from 24/0624UT. An associated eruption off the western limb is
visible in SDO and GOES SUVI imagery from 24/0527UT at around
S25. This CME is not considered geoeffective. A west directed
CME is visible in SOHO imagery from 24/1700UT. An associated
eruption off the western limb is visible from 24/1618UT in SDO
and GOES SUVI imagery at around S12. Modelling of CMEs is difficult
due to an outage to STEREO-A, increasing forecast uncertainty.
This CME is expected to pass ahead of Earth. The solar wind speed
declined slightly on 24-Jul UT day, mostly ranging between 550
km/s and 730 km/s and is currently at around 580 km/s. The peak
total interplanetary field strength (IMF, Bt) was 7 nT and the
north-south IMF component range (Bz) was +6 to -6 nT. The solar
wind speed is expected to remain elevated over 25-Jul, with a
gradual decline, due to ongoing coronal hole high speed wind
stream effects. An increase in solar wind speed is possible on
26-Jul due to the chance of a glancing impact from a CME first
observed on 23-Jul. The solar wind is expected to be in decline
on 27-Jul.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 24 Jul: G0
Estimated Indices 24 Jul : A K
Australian Region 10 32333221
Cocos Island 8 22332221
Darwin 12 33333222
Townsville 11 32333222
Learmonth 15 -4334231
Alice Springs 10 32333221
Gingin 12 32334221
Canberra 10 32333221
Kennaook Cape Grim 11 32333222
Hobart 11 32333222
Estimated Antarctic Regional K Indices 24 Jul :
Macquarie Island 22 32355431
Casey 14 43333322
Mawson 46 65643463
Observed Regional daily pc3 Indices 24 Jul :
Darwin 2 (Quiet)
Townsville 0 (Quiet)
Learmonth 2 (Quiet)
Alice Springs 0 (Quiet)
Gingin 42 (Unsettled)
Canberra 59 (Unsettled)
Hobart 39 (Quiet to 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 16
Planetary 21
Observed AFr/Ap Indices 23 Jul : A K
Fredericksburg 27
Planetary 0 4444 5344
2B. MAGNETIC FORECAST
Date Ap Conditions
25 Jul 15 G0, chance of G1
26 Jul 15 G0, chance of G1
27 Jul 10 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 24-Jul. G2 conditions were observed at Mawson
with G1 conditions observed at Macquarie Island. G0 conditions,
with a chance of G1 are expected on 25-26 Jul due to a combination
of coronal hole high speed wind stream effects and the chance
of a glancing impact from a CME first observed on 23-Jul. G0
conditions are expected on 27-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-fair
26 Jul Normal Normal Normal-fair
27 Jul Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 24-Jul were
mostly normal. HF conditions are expected to be mostly normal
for low to middle latitudes over 25-27 Jul with a chance of slight
degradations due to possible geomagnetic activity. Normal to
fair conditions are expected for high latitudes over 25-27 Jul.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
24 Jul 100
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 15% during local day.
Depressed by 35% during local night.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Enhanced by 20% during local day.
Depressed by 20% during local night.
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 79
Jul 104
Aug 102
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
25 Jul 90 Near predicted monthly values
26 Jul 90 Near predicted monthly values
27 Jul 90 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 24-Jul were mostly near predicted monthly values
in the southern Australian region. In the northern Australian
region, MUFs were depressed by up to 20% during local night and
enhanced by up to 20% during local day. Spread F was observed
during local night hours at Hobart. Sporadic E was observed at
Hobart and Townsville during local night hours. MUFs are expected
to be near predicted monthly values over 25-27 Jul.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 23 Jul
Daily Proton Fluence >1 MeV: 4.2E+05
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 2.10E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 4%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B9.8
DSCOVR Satellite Solar Wind Day Averaged Data for 23 Jul
Speed: 631 km/sec Density: 2.4 p/cc Temp: 327000 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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