[Ips-dsgr] ASWFC Daily Report - 17 August 25 issued 2330 UT on 17 Aug 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Mon Aug 18 09:30:57 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/17 AUGUST 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 17 AUGUST AND FORECAST FOR 18 AUGUST - 20 AUGUST
STATUS INDICATORS SOL:GREEN MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 17 Aug: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 17 Aug: 117/69
1B. SOLAR FORECAST
18 Aug 19 Aug 20 Aug
Activity R0 R0 R0
Fadeouts None expected None expected None expected
10.7cm/SSN 115/66 110/60 110/60
COMMENT: Solar activity on UT day 17-Aug was at the R0 level,
with no significant flaring activity. There are currently five
numbered sunspot regions visible on the solar disk. AR4180 (S02W08,
beta) has exhibited slight spot growth over the UT day. All other
sunspot regions are either stable or in decay. Solar activity
is expected to be at the R0 level over 18-20 Aug. S0 solar proton
conditions were observed on UT day 17-Aug. S0 solar proton conditions
are expected over 18-20 Aug. No Earth-directed CMEs have been
observed. The solar wind speed on UT day 17-Aug decreased, ranging
from 310 to 340 km/s and is currently near 310 km/s. The peak
total interplanetary magnetic field strength (IMF, Bt) was 7
nT and the north-south IMF component (Bz) range was -5 to +7
nT. The solar wind speed is expected to increase over 18-Aug
and remain elevated over 19-20 Aug due to coronal hole high speed
wind stream effects from an equatorial coronal hole.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 17 Aug: G0
Estimated Indices 17 Aug : A K
Australian Region 2 11111100
Cocos Island 1 10111000
Darwin 2 11111101
Townsville 3 11102111
Learmonth 2 01211000
Alice Springs 1 11101001
Gingin 2 11111100
Canberra 1 11011000
Kennaook Cape Grim 2 01112100
Hobart 2 01112100
Estimated Antarctic Regional K Indices 17 Aug :
Macquarie Island 2 00113000
Casey 4 22221100
Mawson 7 33321110
Observed Regional daily pc3 Indices 17 Aug :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 0 (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 Aug : A
Fredericksburg 5
Planetary 6
Observed AFr/Ap Indices 16 Aug : A K
Fredericksburg 6
Planetary 5 1212 1212
2B. MAGNETIC FORECAST
Date Ap Conditions
18 Aug 18 G0-G1
19 Aug 16 G0-G1
20 Aug 16 G0-G1
COMMENT: ASWFC Geomagnetic Warning 60 was issued on 17 August
and is current for 18-19 Aug. G0 geomagnetic conditions were
observed in the Australian and Antarctic regions on UT day 17-Aug.
G0-G1 geomagnetic conditions are expected over 18-20 Aug due
to coronal hole high speed wind stream effects from an equatorial
coronal hole.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
17 Aug Normal Normal-fair Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
18 Aug Normal Normal-fair Fair
19 Aug Normal Normal-fair Fair
20 Aug Normal Normal-fair Fair
COMMENT: HF radio propagation conditions on UT day 17-Aug were
mostly normal, with periods of fair conditions at high and mid
latitudes. HF radio propagation conditions are expected to be
mostly normal over 18-20 Aug, with fair conditions at high latitudes
over 18-20 Aug due to expected geomagnetic activity.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
17 Aug 94
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values during local day.
Depressed by 15% during local night.
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
Jul 88
Aug 96
Sep 93
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
18 Aug 90 Near predicted monthly values
19 Aug 80 Near predicted monthly values
20 Aug 80 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 17-Aug were mostly near predicted monthly values
with depressions of 15% observed in the Northern Australian region
during local night hours. Spread F was observed at Canberra,
Darwin, Hobart and Perth during local night hours. MUFs are expected
to be near predicted monthly values over 18-20 Aug.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 16 Aug
Daily Proton Fluence >1 MeV: 8.2E+04
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 3.60E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:20%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B5.8
DSCOVR Satellite Solar Wind Day Averaged Data for 16 Aug
Speed: 361 km/sec Density: 2.2 p/cc Temp: 56200 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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