[Ips-dsgr] ASWFC Daily Report - 19 August 25 issued 2330 UT on 19 Aug 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Wed Aug 20 09:30:49 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/19 AUGUST 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 19 AUGUST AND FORECAST FOR 20 AUGUST - 22 AUGUST
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 19 Aug: R1
Flares Max Fadeout Freq. Sectors
M1.1 0440UT possible lower E. Asia/Aust.
Observed 10.7 cm flux/Equivalent Sunspot Number for 19 Aug: 116/68
1B. SOLAR FORECAST
20 Aug 21 Aug 22 Aug
Activity R0, chance of R1 R0, chance of R1 R0, chance of R1
Fadeouts Possible Possible Possible
10.7cm/SSN 115/66 115/66 115/66
COMMENT: Solar activity on UT day 19-Aug was at the R1 level,
due to an M1.1 flare at 19/0440UT. There are currently four numbered
sunspot regions visible on the solar disk and all are small and
magnetically simple. AR4187 (S19E17, beta) and newly numbered
AR4189 (N07E51, alpha) showed development over the UT day. All
other sunspot regions are stable. Solar activity is expected
to be at the R0 level over 20-22 Aug, with a chance of R1. S0
solar proton conditions were observed on UT day 19-Aug. S0 solar
proton conditions are expected over 20-22 Aug. No Earth-directed
CMEs have been observed. An east directed, narrow and slow CME
is visible in SOHO and STEREO-A imagery from 19/0500UT. This
CME is associated with an eruption visible from 19/0402UT and
concurrent with the M1.1 flare. This CME is expected to pass
well behind the Earth. The solar wind speed on UT day 19-Aug
increased significantly, ranging from 340 to 720 km/s and is
currently near 615 km/s. This indicates we have entered the expected
high speed wind stream from an equatorial hole on the western
half of the solar disk. The peak total interplanetary magnetic
field strength (IMF, Bt) was 20 nT and the north-south IMF component
(Bz) range was -11 to +16 nT. The solar wind speed is expected
to remain elevated over 20-22 Aug due to ongoing coronal hole
high speed wind stream effects. A gradual design is possible
on 22-Aug.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 19 Aug: G0
Estimated Indices 19 Aug : A K
Australian Region 13 22233343
Cocos Island 9 22123331
Darwin 12 22223343
Townsville 16 22233353
Learmonth 16 32223353
Alice Springs 14 22123353
Gingin 16 22233353
Canberra 13 22233343
Kennaook Cape Grim 13 22233343
Hobart 17 22243353
Estimated Antarctic Regional K Indices 19 Aug :
Macquarie Island 24 11253554
Casey 25 44323553
Mawson 30 23323374
Observed Regional daily pc3 Indices 19 Aug :
Darwin 11 (Quiet)
Townsville 6 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 4 (Quiet)
Gingin 29 (Quiet to unsettled)
Canberra 47 (Unsettled)
Hobart 74 (Active)
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 Aug : A
Fredericksburg 15
Planetary 21
Observed AFr/Ap Indices 18 Aug : A K
Fredericksburg 7
Planetary 0 0112 2312
2B. MAGNETIC FORECAST
Date Ap Conditions
20 Aug 18 G0-G1
21 Aug 12 G0, chance of G1
22 Aug 8 G0
COMMENT: ASWFC Geomagnetic Warning 61 was issued on 18 August
and is current for 19-20 Aug. Mostly G0 geomagnetic conditions
were observed in the Australian region, with periods of G1 conditions
observed at Townsville, Learmonth, Alice Springs, Gingin and
Hobart. Mostly G1 conditions were observed in the Antarctic region,
with G3 conditions observed at Mawson. G0-G1 geomagnetic conditions
are expected on 20-Aug and G0 conditions, with a chance of G1
are expected on 21-Aug due to coronal hole high speed wind stream
effects from an equatorial coronal hole. G0 conditions are expected
on 22-Aug.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
19 Aug Normal Normal-fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
20 Aug Normal Normal-fair Fair
21 Aug Normal Normal Normal-fair
22 Aug Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 19-Aug were
mostly normal, with periods of poor to fair conditions at high
latitudes. HF radio propagation conditions are expected to be
mostly normal over 20-22 Aug, with fair to poor conditions likely
at high latitudes over 20-21 Aug due to expected geomagnetic
activity.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
19 Aug 96
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Depressed by 35% during local night.
Niue Island Region:
Near predicted monthly values during local day.
Depressed by 15% during local night.
Northern Australian Region:
Mostly near predicted monthly values.
Southern Australian Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
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
20 Aug 90 Near predicted monthly values
21 Aug 90 Near predicted monthly values
22 Aug 95 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 19-Aug were mostly near predicted monthly values,
with some enhancements observed in the southern Australian region
during local night. Spread F was observed at Hobart during local
night hours. MUFs are expected to be mostly near predicted monthly
values over 20-22 Aug.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 18 Aug
Daily Proton Fluence >1 MeV: 4.6E+05
Daily Proton Fluence >10 MeV: 1.5E+04
Daily Electron Fluence >2 MeV: 5.50E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 7%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B5.5
DSCOVR Satellite Solar Wind Day Averaged Data for 18 Aug
Speed: 337 km/sec Density: 4.8 p/cc Temp: 37800 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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