[Ips-dsgr] ASWFC Daily Report - 24 May 25 issued 2330 UT on 24 May 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sun May 25 09:30:49 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/24 MAY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 24 MAY AND FORECAST FOR 25 MAY - 27 MAY
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 24 May: R1
Flares Max Fadeout Freq. Sectors
M2.1 2023UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 24 May: 130/84
1B. SOLAR FORECAST
25 May 26 May 27 May
Activity R1, chance R2 R1, chance R2 R1, chance R2
Fadeouts Possible Possible Possible
10.7cm/SSN 135/89 140/94 135/89
COMMENT: Solar activity on UT day 24-May was at the R1 level
due to an M2.1 flare at 24/2023UT produced by AR4098 (S04W37,
beta-gamma-delta). There are currently eight numbered sunspot
regions visible on the solar disk. AR4098 is the most magnetically
complex region on the disk and has exhibited spot growth over
the UT day, including the recent development of a delta spot.
AR4087 (N17W82, alpha) is stable and will soon rotate over the
western limb. All other sunspot regions are either stable or
in decay. Solar activity is expected to be at the R1 level over
25-27 May, with a chance of R2. Several CMEs were observed, but
none are considered geoeffective. The solar wind speed on UT
day 24-May declined, ranging from 370 to 450 km/s and is currently
near 435 km/s. The peak total interplanetary magnetic field strength
(IMF, Bt) was 10 nT and the north-south IMF component (Bz) range
was -6 to +5 nT. A small equatorial coronal hole is currently
crossing the central meridian and may influence the solar wind
speed on 28-May. The solar wind speed is expected to mildly decline
over 25-27 May due to waning coronal hole high speed wind stream
effects.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 24 May: G0
Estimated Indices 24 May : A K
Australian Region 2 21100001
Cocos Island 1 11110000
Darwin 4 31210102
Townsville 2 11110102
Learmonth 2 21210001
Alice Springs 2 21100001
Gingin 2 21200001
Canberra 1 21000001
Kennaook Cape Grim 1 21000001
Hobart 0 11000000
Estimated Antarctic Regional K Indices 24 May :
Macquarie Island 0 00011000
Casey 5 23320001
Mawson 11 32211144
Observed Regional daily pc3 Indices 24 May :
Darwin 3 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 2 (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 24 May : A
Fredericksburg 7
Planetary 8
Observed AFr/Ap Indices 23 May : A K
Fredericksburg 8
Planetary 7 2222 2212
2B. MAGNETIC FORECAST
Date Ap Conditions
25 May 5 G0
26 May 6 G0
27 May 6 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
and Antarctic regions on UT day 24-May. G0 geomagnetic conditions
are expected over 25-27 May.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
24 May Normal-fair Normal-fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
25 May Normal Normal Normal
26 May Normal Normal Normal
27 May Normal Normal Normal
COMMENT: HF radio propagation conditions on UT day 24-May were
normal to fair. HF radio propagation conditions are expected
to be mostly normal over 25-27 May. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
24 May 86
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 35% during local day.
Depressed by 15% during local night.
Northern Australian Region:
Depressed by 15% during local day.
Depressed by 25% during local night.
Southern Australian Region:
Near predicted monthly values during local day.
Depressed by 20% during local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 15% 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
25 May 85 Depressed 15%/near predicted monthly values
26 May 85 Depressed 15%/near predicted monthly values
27 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 24-May were near predicted
monthly values to 15-25% depressed. Spread F was observed at
Hobart during local night hours. MUFs are expected to be near
predicted monthly values to 15% depressed over 25-27 May. Shortwave
fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 23 May
Daily Proton Fluence >1 MeV: 1.7E+05
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 7.40E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 9%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B5.7
DSCOVR Satellite Solar Wind Day Averaged Data for 23 May
Speed: 470 km/sec Density: 2.4 p/cc Temp: 152000 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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