[Ips-dsgr] ASWFC Daily Report - 02 September 25 issued 2330 UT on 02 Sep 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Wed Sep 3 09:30:45 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/02 SEPTEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 02 SEPTEMBER AND FORECAST FOR 03 SEPTEMBER - 05 SEPTEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 02 Sep: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 02 Sep: 187/140
1B. SOLAR FORECAST
03 Sep 04 Sep 05 Sep
Activity R1 R1 R1
Fadeouts Possible Possible Possible
10.7cm/SSN 185/138 185/138 182/135
COMMENT: Solar activity on UT day 02-Sep was at the R0 level,
with no significant flaring activity. There are currently ten
numbered sunspot regions visible on the solar disk. AR4197 (S18W62,
beta) is the largest region on the disk and has shown growth
in its intermediate spots over the UT day whilst remaining flare
quiet. AR4207 (N30E28, beta) has exhibited growth in its intermediate
spots. Newly numbered AR4210 (N08E57, beta) recently appeared
on the solar disk and has shown rapid development. New region
AR4211 (S15E72, alpha) recently rotated onto the visible disk
and appears stable. All other sunspot regions are either stable
or in decay. Solar activity is expected to be at the R1 level
over 03-05 Sep. S0 solar proton conditions were observed on UT
day 02-Sep. S0 solar proton conditions are expected over 03-05
Sep. No Earth-directed CMEs have been observed. The solar wind
speed on UT day 02-Sep decreased, ranging from 520 to 690 km/s
and is currently near 550 km/s. The solar wind speed was elevated
due to a CME arrival late on 01-Sep. The peak total interplanetary
magnetic field strength (IMF, Bt) was 26 nT and the north-south
IMF component (Bz) range was -23 to +21 nT. A sustained period
of southward IMF conditions began at 02/1600UT and is ongoing.
The solar wind speed is expected to remain elevated over 03-04
Sep due to ongoing CME effects. A recurrent southern hemisphere
coronal hole is currently crossing the central meridian and is
likely to influence the solar wind from 05-Sep.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 02 Sep: G1
Estimated Indices 02 Sep : A K
Australian Region 33 54543454
Cocos Island 22 44542333
Darwin 30 54543444
Townsville 33 54543454
Learmonth 36 54543455
Alice Springs 32 54542454
Gingin 33 53533455
Canberra 26 54542343
Kennaook Cape Grim 30 54533453
Hobart 28 54533353
Estimated Antarctic Regional K Indices 02 Sep :
Macquarie Island 36 44424663
Casey 37 56533543
Mawson 41 65432465
Observed Regional daily pc3 Indices 02 Sep :
Darwin 4 (Quiet)
Townsville 2 (Quiet)
Learmonth 13 (Quiet)
Alice Springs 5 (Quiet)
Gingin 45 (Unsettled)
Canberra 48 (Unsettled)
Hobart 85 (Minor storm)
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 02 Sep : A
Fredericksburg 28
Planetary 46
Observed AFr/Ap Indices 01 Sep : A K
Fredericksburg 9 1112 2234
Planetary 16 2111 1236
2B. MAGNETIC FORECAST
Date Ap Conditions
03 Sep 18 G0-G1
04 Sep 10 G0
05 Sep 20 G0-G1
COMMENT: ASWFC Geomagnetic Warning 63 was issued on 1 September
and is current for 2-3 Sep. G1 geomagnetic conditions were observed
in the Australian region on UT day 02-Sep. G2 geomagnetic conditions
were observed in the Antarctic region. Geomagnetic activity over
the UT day was due to the arrival of a halo CME late on 01-Sep.
G0-G1 geomagnetic conditions are expected on 03-Sep due to ongoing
CME effects. G0 geomagnetic conditions are expected on 04-Sep.
G0-G1 geomagnetic conditions are expected on 05-Sep due to a
recurrent southern hemisphere coronal hole moving into a geoeffective
position.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
02 Sep Normal Normal-fair Fair-poor
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
03 Sep Normal Normal-fair Fair
04 Sep Normal Normal Normal-fair
05 Sep Normal Normal-fair Fair
COMMENT: HF radio propagation conditions on UT day 02-Sep were
mostly normal at low and mid latitudes and fair to poor at high
latitudes. HF radio propagation conditions are expected to be
normal to fair over 03-05 Sep. Shortwave fadeouts are possible.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
02 Sep 130
Observed Australian Regional MUFs
Cocos Island Region:
No data available.
Niue Island Region:
Mostly near predicted monthly values.
Northern Australian Region:
Mostly near predicted monthly values.
Enhanced by 20% after local dawn.
Southern Australian Region:
Enhanced by 20% during local day.
Enhanced by 25% during local night.
Depressed by 40% after local dawn.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 20% over the UT day.
Monthly T index:
Month T index
Aug 96
Sep 92
Oct 90
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
03 Sep 105 Near predicted monthly values
04 Sep 110 Near to 15% above predicted monthly values
05 Sep 105 Near predicted monthly values
COMMENT: ASWFC Preliminary HF Communications Warning 79 was issued
on 31 August and is current for 2-3 Sep. Maximum usable frequencies
(MUFs) in the northern Australian region on UT day 02-Sep were
near predicted monthly values. MUFs in the southern Australian
region were enhanced by 20-25% and became 40% depressed after
local dawn. Spread F was observed at Hobart, Canberra and Perth
during local night hours. MUFs are expected to be near predicted
monthly values over 03-05 Sep with 15% enhancements on 04-Sep.
Shortwave fadeouts are possible.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 01 Sep
Daily Proton Fluence >1 MeV: 1.5E+08
Daily Proton Fluence >10 MeV: 2.4E+05
Daily Electron Fluence >2 MeV: 1.50E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.6
DSCOVR Satellite Solar Wind Day Averaged Data for 01 Sep
Speed: 406 km/sec Density: 2.9 p/cc Temp: 71300 K Bz: 1 nT
(Courtesy Space Weather Prediction Center, Boulder USA)
-----------------------------------------------------------
Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au
More information about the ips-dsgr
mailing list