[Ips-dsgr] ASWFC Daily Report - 17 July 25 issued 2332 UT on 17 Jul 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Fri Jul 18 09:32:22 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/17 JULY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 17 JULY AND FORECAST FOR 18 JULY - 20 JULY
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 17 Jul: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 17 Jul: 156/110
1B. SOLAR FORECAST
18 Jul 19 Jul 20 Jul
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 158/112 155/109 150/105
COMMENT: Solar activity on UT day 17-Jul was R0, with no significant
solar flares. There are currently 11 numbered sunspot regions
on the solar disk. AR4136 (N19W40, beta-gamma), AR4143 (N23W24,
beta-gamma) and AR4148 (S05W07, beta) all showed growth throughout
the day, with AR4136 currently being the most complex region.
All other sunspot regions are either stable or in decay. Solar
activity is expected to be R0-R1 over 18-20 Jul. No Earth directed
CMEs were observed on UT day 17-Jul. S0 solar radiation storm
conditions were observed on UT day 17-Jul. S0 solar radiation
storm conditions are expected over 18-20 Jul. On UT day 17-Jul
the solar wind environment was mildly elevated due to ongoing
coronal hole effects. The solar wind speed ranged from near 750
to 540 km/s and currently on a gentle decline. The peak total
interplanetary field strength (IMF, Bt) was 8 nT and the north-south
IMF component range (Bz) was +6 to -7 nT. The solar wind is expected
to remain mildly elevated on UT day 18-Jul before beginning to
return to background levels over 19-20 Jul.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 17 Jul: G0
Estimated Indices 17 Jul : A K
Australian Region 13 33333331
Cocos Island 10 22233331
Darwin 14 33333332
Townsville 13 33333322
Learmonth 17 33344332
Alice Springs 12 33333321
Gingin 16 33344331
Canberra 11 23333321
Kennaook Cape Grim 13 22344321
Hobart 13 22343331
Estimated Antarctic Regional K Indices 17 Jul :
Macquarie Island 23 33355431
Casey 25 34433362
Mawson 40 65544345
Observed Regional daily pc3 Indices 17 Jul :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 6 (Quiet)
Canberra 14 (Quiet)
Hobart 0 (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 17 Jul : A
Fredericksburg 13
Planetary 20
Observed AFr/Ap Indices 16 Jul : A K
Fredericksburg 14
Planetary 17 3334 2135
2B. MAGNETIC FORECAST
Date Ap Conditions
18 Jul 15 G0, chance G1
19 Jul 11 G0
20 Jul 9 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 17-Jul. G0-G2 geomagnetic conditions were observed
in the Antarctic region. G0 geomagnetic conditions with a chance
of G1 are expected on UT day 18-Jul. G0 geomagnetic conditions
are expected over 19-20 Jul as coronal hole effects abate.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
17 Jul Normal-fair Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
18 Jul Normal-fair Normal Normal-fair
19 Jul Normal Normal Normal-fair
20 Jul Normal Normal Normal-fair
COMMENT: HF radio propagation on UT day 17-Jul was normal to
mildly degraded. HF radio propagation conditions are expected
to be similar over UT day 18-Jul, becoming normal over 19-20
Jul.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
17 Jul 86
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 15% during local day.
Depressed by 45% during local night.
Depressed by 20% after local dawn.
Niue Island Region:
Near predicted monthly values during local day.
Depressed by 25% during local night.
Northern Australian Region:
Depressed by 15% during local day.
Depressed by 15% during local night.
Depressed by 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
18 Jul 80 Depressed 10 to 20%/near predicted monthly values
19 Jul 82 Depressed 10 to 15%/near predicted monthly values
20 Jul 85 Depressed 10 to 15%/near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region were near predicted values to 15-20% depressed. Spread-F
was observed during local night hours at Hobart and Learmonth.
Sporadic-E was also observed at Darwin, Learmonth, Niue and Townsville
over the UT day. MUFs are expected to be similar over the UT
day 18-Jul and then slowly improving to 10-15% depressed over
19-20 Jul.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 16 Jul
Daily Proton Fluence >1 MeV: 1.7E+06
Daily Proton Fluence >10 MeV: 1.8E+04
Daily Electron Fluence >2 MeV: 1.50E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:13%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B9.0
DSCOVR Satellite Solar Wind Day Averaged Data for 16 Jul
Speed: 559 km/sec Density: 0.2 p/cc Temp: 136000 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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