[Ips-dsgr] ASWFC Daily Report - 23 May 25 issued 2330 UT on 23 May 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sat May 24 09:30:50 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/23 MAY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 23 MAY AND FORECAST FOR 24 MAY - 26 MAY
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 23 May: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 23 May: 122/75
1B. SOLAR FORECAST
24 May 25 May 26 May
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 120/72 120/72 130/84
COMMENT: Solar activity on UT day 23-May was at the R0 level,
with no significant flaring activity. There are currently eight
numbered sunspot regions visible on the solar disk. AR4087 (N17W61,
alpha) is the largest region on the disk and is stable. AR4098
(S04W22, beta) has exhibited spot development over the UT day.
All other sunspot regions are either stable or in decay. Solar
activity is expected to be at R0-R1 levels over 24-26 May. No
Earth-directed CMEs have been observed. A halo CME was observed,
visible in LASCO C2 coronagraph imagery from 23/1700UT. This
CME is considered to be a farside event and not geoeffective.
The solar wind speed on UT day 23-May declined, ranging from
425 to 520 km/s and is currently near 425 km/s. The peak total
interplanetary magnetic field strength (IMF, Bt) was 8 nT and
the north-south IMF component (Bz) range was -5 to +7 nT. The
solar wind speed is expected to decline over 24-26 May due to
waning coronal hole high speed wind stream effects.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 23 May: G0
Estimated Indices 23 May : A K
Australian Region 4 22221101
Cocos Island 2 11111100
Darwin 7 2-------
Townsville 5 22221112
Learmonth 5 22222201
Alice Springs 3 21211200
Gingin 5 22212201
Canberra 3 11221101
Kennaook Cape Grim 3 11221101
Hobart 5 22212102
Estimated Antarctic Regional K Indices 23 May :
Macquarie Island 4 11122201
Casey 10 33332211
Mawson 16 34432323
Observed Regional daily pc3 Indices 23 May :
Darwin 60 (Unsettled)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 11 (Quiet)
Canberra 17 (Quiet)
Hobart 21 (Quiet to unsettled)
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 May : A
Fredericksburg 7
Planetary 8
Observed AFr/Ap Indices 22 May : A K
Fredericksburg 6
Planetary 0 2221 2122
2B. MAGNETIC FORECAST
Date Ap Conditions
24 May 8 G0
25 May 5 G0
26 May 6 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
and Antarctic regions on UT day 23-May. G0 geomagnetic conditions
are expected over 24-26 May.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
23 May Normal Normal-fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
24 May Normal Normal Normal-fair
25 May Normal Normal Normal
26 May Normal Normal Normal
COMMENT: HF radio propagation conditions on UT day 23-May were
normal to fair. HF radio propagation conditions are expected
to be normal to fair over 24-26 May. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
23 May 83
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Depressed by 15% during local night.
Niue Island Region:
Near predicted monthly values during local day.
Northern Australian Region:
Depressed by 15% during local day.
Depressed by 30% during local night.
Southern Australian Region:
Near predicted monthly values during local day.
Depressed by 20% during local night.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Apr 123
May 113
Jun 111
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
24 May 85 Depressed 15%/near predicted monthly values
25 May 85 Depressed 15%/near predicted monthly values
26 May 85 Depressed 15%/near predicted monthly values
COMMENT: ASWFC HF Communications Warning 51 was issued on 23
May and is current for 23-25 May. Maximum usable frequencies
(MUFs) in the Australian region on UT day 23-May were near predicted
monthly values to 15-30% depressed. Spread F was observed at
Hobart during local night hours. MUFs are expected to be near
predicted monthly values to 15% depressed over 24-26 May. Shortwave
fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 22 May
Daily Proton Fluence >1 MeV: 1.5E+05
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 6.90E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 8%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B4.7
DSCOVR Satellite Solar Wind Day Averaged Data for 22 May
Speed: 506 km/sec Density: 2.0 p/cc Temp: 194000 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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