[Ips-dsgr] ASWFC Daily Report - 23 August 25 issued 2330 UT on 23 Aug 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sun Aug 24 09:30:06 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/23 AUGUST 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 23 AUGUST AND FORECAST FOR 24 AUGUST - 26 AUGUST
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 23 Aug: R1
Flares Max Fadeout Freq. Sectors
M1.9 2006UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 23 Aug: 143/97
1B. SOLAR FORECAST
24 Aug 25 Aug 26 Aug
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 145/99 145/99 145/99
COMMENT: Solar activity on UT day 23-Aug was at the R1 level,
due to an M1.9 flare at 23/2006UT. There are currently four numbered
sunspot regions visible on the solar disk. AR4191 (N13E43, beta)
is the largest region on the solar disk and showed significant
spot development over the UT day. This region was also responsible
for the M1.9 flare observed today. All other sunspot regions
are either stable or in decay. Solar activity is expected to
be at R0-R1 levels over 24-26 Aug due to the recently developed
AR4191. Solar proton conditions were enhanced but below the S1
level on UT day 23-Aug. S0 solar proton conditions are expected
over 24-26 Aug, with a chance of S1 conditions on 24-Aug. No
significantly Earth-directed CMEs were observed on 23-Aug. Several
CMEs were observed on 23-Aug, but none are considered geoeffective.
A large filament lift off was observed in GOES SUVI and H-Alpha
imagery on the north east limb from 23/1030UT. An associated
CME is visible from 23/1348UT in SOHO and STEREO-A imagery. This
CME is expected to pass north of and ahead of the Earth. An east
directed partial halo CME from 22/1938UT has been analysed and
presents the chance of a glancing impact on 25-Aug in the second
half of the UT day. The solar wind speed on UT day 23-Aug declined,
ranging from 400 to 530 km/s and is currently near 405 km/s.
The peak total interplanetary magnetic field strength (IMF, Bt)
was 5 nT and the north-south IMF component (Bz) range was -3
to +4 nT. The solar wind speed is expected to decline gradually
towards background levels on 24-Aug as coronal hole high speed
wind stream effects wane. An increase in wind speed is possible
over 25-26 Aug due to a combination of two possible glancing
CME impacts late on 25-Aug and high speed solar wind stream effects
due to a northern hemisphere coronal hole, expected to be in
a geoeffective location on 26-Aug.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 23 Aug: G0
Estimated Indices 23 Aug : A K
Australian Region 2 12110001
Cocos Island 1 11110000
Darwin 3 22200001
Townsville 3 22111011
Learmonth 3 22120000
Alice Springs 2 12110001
Gingin 2 22110100
Canberra 2 12010001
Kennaook Cape Grim 3 12111101
Hobart 2 12111100
Estimated Antarctic Regional K Indices 23 Aug :
Macquarie Island 1 12000000
Casey 8 33311121
Mawson 14 44330133
Observed Regional daily pc3 Indices 23 Aug :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 16 (Quiet)
Canberra 11 (Quiet)
Hobart 7 (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 23 Aug : A
Fredericksburg 6
Planetary 7
Observed AFr/Ap Indices 22 Aug : A K
Fredericksburg 9
Planetary 9 3211 1223
2B. MAGNETIC FORECAST
Date Ap Conditions
24 Aug 6 G0
25 Aug 12 G0, chance of G1
26 Aug 20 G0, chance of G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
and Antarctic regions on UT day 23-Aug. G0 geomagnetic conditions
are expected on 24-Aug. G0 conditions, with a chance of G1 are
expected over 25-26 Aug due to a combination of two possible
glancing CME impacts late on 25-Aug and high speed solar wind
stream effects due to a northern hemisphere coronal hole, expected
to be in a geoeffective location on 26-Aug.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
23 Aug Normal Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
24 Aug Normal Normal Normal
25 Aug Normal Normal Normal-fair
26 Aug Normal Normal-fair Fair
COMMENT: HF radio propagation conditions on UT day 23-Aug were
mostly normal. HF radio propagation conditions are expected to
be mostly normal over 24-26 Aug, with possible degradations,
mostly at high latitudes, on 26-Aug.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
23 Aug 95
Observed Australian Regional MUFs
Cocos Island Region:
No data available during local day.
No data available during local night.
Niue Island Region:
Enhanced by 20% during local day.
Enhanced by 45% during local night.
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
Jul 88
Aug 96
Sep 93
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
24 Aug 100 Near predicted monthly values
25 Aug 100 Near predicted monthly values
26 Aug 80 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 24-Aug were near predicted monthly values. Spread
F was observed at Hobart and Brisbane during local night hours.
MUFs are expected to be near predicted monthly values over 24-26
Aug, with a chance of mild depressions on 26-Aug due to possible
geomagnetic activity.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 22 Aug
Daily Proton Fluence >1 MeV: 5.2e+05
Daily Proton Fluence >10 MeV: 2.7e+04
Daily Electron Fluence >2 MeV: 3.00e+07
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B9.2
DSCOVR Satellite Solar Wind Day Averaged Data for 22 Aug
Speed: 519 km/sec Density: 1.4 p/cc Temp: 120000 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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